[1/2] ipa-sra: Introduce a mini-DCE to tree-inline.c (PR 93385)

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  • [1/2] ipa-sra: Introduce a mini-DCE to tree-inline.c (PR 93385)
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Commit Message

Martin Jambor April 27, 2021, 1:01 p.m.
Hi,

PR 93385 reveals that if the user explicitely disables DCE, IPA-SRA
can leave behind statements which are useless because their results
are eventually not used but can have problematic side effects,
especially since their inputs are now bogus that useless parameters
were removed.

This patch fixes the problem by doing a def-use walk when
materializing clones, marking which statements should not be copied
and which SSA_NAMEs do not need to be computed because eventually they
would be DCEd.

When an argument of a call within such a function is removed,
however, that change needs to be communicated to call redirection code.
This is call specific information and therefore cannot be reasonably
encoded in clone node summary and has to be put in call summaries.
Combining these with stuff in performed_splits in clone_info would be
very cumbersome and therefore this patch removes performed_splits and
moves all information it into call summaries too.  This has also the
advantage that the code is hopefully a bit easier to understand and we
do not need any special dummy variables.

The new edge summaries are private to ipa-param-manipulation.c and
hopefully will never be needed elsewhere.  It simply contains 1) a
mapping from the original argument indices to the actual indices in the
call statement as it is now, 2) information needed to identify
arguments representing pass-through IPA-SRA splits with which have
been added to the call arguments in place of an original
argument/reference and 3) a delta to the index where va_args may
start.

Bootstrapped and tested on x86_64-linux, i686-linux and aarch64-linux.
Also LTO-bootstrapped and LTO-profiledbootstrapped on x86_64-linux.

OK for trunk?

Thanks,

Martin


gcc/ChangeLog:

2021-03-24  Martin Jambor  <mjambor@suse.cz>

	PR ipa/93385
	* symtab-clones.h (clone_info): Removed member param_adjustments.
	* ipa-param-manipulation.h: Adjust initial comment to reflect how we
	deal with pass-through splits now.
	(ipa_param_performed_split): Removed.
	(ipa_param_adjustments::modify_call): Adjusted parameters.
	(class ipa_param_body_adjustments): New members m_dead_stmts,
	m_dead_ssas, mark_dead_statements, modify_call_argument and
	m_new_call_arg_modification_info.  Adjusted parameters of
	register_replacement, modify_gimple_stmt and modify_call_stmt.
	(ipa_verify_edge_has_no_modifications): Declare.
	* ipa-param-manipulation.c (struct pass_through_split_map): New type.
	(ipa_edge_modification_info): Likewise.
	(ipa_edge_modification_sum): Likewise.
	(ipa_edge_modifications): New edge summary.
	(ipa_verify_edge_has_no_modifications): New function.
	(transitive_split_p): Removed.
	(transitive_split_map): Likewise.
	(init_transitive_splits): Likewise.
	(ipa_param_adjustments::modify_call): Adjusted to use the new edge
	summary instead of performed_splits.
	(ipa_param_body_adjustments::register_replacement): Drop dummy
	parameter, set base_index of the created ipa_param_body_replacement.
	(phi_arg_will_live_p): New function.
	(ipa_param_body_adjustments::mark_dead_statements): New method.
	(ipa_param_body_adjustments::common_initialization): Call it.  Do not
	create IPA_SRA dummy decls.
	(ipa_param_body_adjustments::ipa_param_body_adjustments): Initialize
	new mwmbers.
	(simple_tree_swap_info): Removed.
	(remap_split_decl_to_dummy): Likewise.
	(record_argument_state_1): New function.
	(record_argument_state): Likewise.
	(ipa_param_body_adjustments::modify_call_stmt): New parameter
	orig_stmt.  Do not work with dummy decls, save necessary info about
	changes to ipa_edge_modifications.
	(ipa_param_body_adjustments::modify_gimple_stmt): New parameter
	orig_stmt, pass it to modify_call_stmt.
	(ipa_param_body_adjustments::modify_cfun_body): Adjust call to
	modify_gimple_stmt.
	* tree-inline.c (remap_gimple_stmt): Do not copy dead statements,
	reset dead debug statements, pass original statement to
	modify_gimple_stmt.
	(copy_phis_for_bb): Do not copy dead PHI nodes.
	(expand_call_inline): Do not remap performed_splits.
	(update_clone_info): Likewise.

gcc/testsuite/ChangeLog:

2021-03-22  Martin Jambor  <mjambor@suse.cz>

	PR ipa/93385
	* gcc.dg/ipa/pr93385.c: New test.
	* gcc.dg/ipa/ipa-sra-23.c: Likewise.
	* gcc.dg/ipa/ipa-sra-24.c: Likewise.
	* g++.dg/ipa/ipa-sra-4.C: Likewise.
---
 gcc/cgraph.c                          |  22 +-
 gcc/cgraphclones.c                    |   3 -
 gcc/ipa-param-manipulation.c          | 916 ++++++++++++++++----------
 gcc/ipa-param-manipulation.h          |  92 ++-
 gcc/symtab-clones.h                   |  15 +-
 gcc/testsuite/g++.dg/ipa/ipa-sra-4.C  |  37 ++
 gcc/testsuite/gcc.dg/ipa/ipa-sra-23.c |  24 +
 gcc/testsuite/gcc.dg/ipa/ipa-sra-24.c |  20 +
 gcc/testsuite/gcc.dg/ipa/pr93385.c    |  27 +
 gcc/tree-inline.c                     | 121 +---
 10 files changed, 721 insertions(+), 556 deletions(-)
 create mode 100644 gcc/testsuite/g++.dg/ipa/ipa-sra-4.C
 create mode 100644 gcc/testsuite/gcc.dg/ipa/ipa-sra-23.c
 create mode 100644 gcc/testsuite/gcc.dg/ipa/ipa-sra-24.c
 create mode 100644 gcc/testsuite/gcc.dg/ipa/pr93385.c

-- 
2.31.1

Comments

Andre Vehreschild via Gcc-patches May 10, 2021, 1:17 p.m. | #1
On Tue, Apr 27, 2021 at 5:25 PM Martin Jambor <mjambor@suse.cz> wrote:
>

> Hi,

>

> PR 93385 reveals that if the user explicitely disables DCE, IPA-SRA

> can leave behind statements which are useless because their results

> are eventually not used but can have problematic side effects,

> especially since their inputs are now bogus that useless parameters

> were removed.

>

> This patch fixes the problem by doing a def-use walk when

> materializing clones, marking which statements should not be copied

> and which SSA_NAMEs do not need to be computed because eventually they

> would be DCEd.

>

> When an argument of a call within such a function is removed,

> however, that change needs to be communicated to call redirection code.

> This is call specific information and therefore cannot be reasonably

> encoded in clone node summary and has to be put in call summaries.

> Combining these with stuff in performed_splits in clone_info would be

> very cumbersome and therefore this patch removes performed_splits and

> moves all information it into call summaries too.  This has also the

> advantage that the code is hopefully a bit easier to understand and we

> do not need any special dummy variables.

>

> The new edge summaries are private to ipa-param-manipulation.c and

> hopefully will never be needed elsewhere.  It simply contains 1) a

> mapping from the original argument indices to the actual indices in the

> call statement as it is now, 2) information needed to identify

> arguments representing pass-through IPA-SRA splits with which have

> been added to the call arguments in place of an original

> argument/reference and 3) a delta to the index where va_args may

> start.

>

> Bootstrapped and tested on x86_64-linux, i686-linux and aarch64-linux.

> Also LTO-bootstrapped and LTO-profiledbootstrapped on x86_64-linux.

>

> OK for trunk?


I've tried to have a look at this patch but it does a lot of IPA specific
refactoring(?), so the actual DCE bits are hard to find.  Is it possible
to split the patch up or is it too entangled?

Thanks,
Richard.

> Thanks,

>

> Martin

>

>

> gcc/ChangeLog:

>

> 2021-03-24  Martin Jambor  <mjambor@suse.cz>

>

>         PR ipa/93385

>         * symtab-clones.h (clone_info): Removed member param_adjustments.

>         * ipa-param-manipulation.h: Adjust initial comment to reflect how we

>         deal with pass-through splits now.

>         (ipa_param_performed_split): Removed.

>         (ipa_param_adjustments::modify_call): Adjusted parameters.

>         (class ipa_param_body_adjustments): New members m_dead_stmts,

>         m_dead_ssas, mark_dead_statements, modify_call_argument and

>         m_new_call_arg_modification_info.  Adjusted parameters of

>         register_replacement, modify_gimple_stmt and modify_call_stmt.

>         (ipa_verify_edge_has_no_modifications): Declare.

>         * ipa-param-manipulation.c (struct pass_through_split_map): New type.

>         (ipa_edge_modification_info): Likewise.

>         (ipa_edge_modification_sum): Likewise.

>         (ipa_edge_modifications): New edge summary.

>         (ipa_verify_edge_has_no_modifications): New function.

>         (transitive_split_p): Removed.

>         (transitive_split_map): Likewise.

>         (init_transitive_splits): Likewise.

>         (ipa_param_adjustments::modify_call): Adjusted to use the new edge

>         summary instead of performed_splits.

>         (ipa_param_body_adjustments::register_replacement): Drop dummy

>         parameter, set base_index of the created ipa_param_body_replacement.

>         (phi_arg_will_live_p): New function.

>         (ipa_param_body_adjustments::mark_dead_statements): New method.

>         (ipa_param_body_adjustments::common_initialization): Call it.  Do not

>         create IPA_SRA dummy decls.

>         (ipa_param_body_adjustments::ipa_param_body_adjustments): Initialize

>         new mwmbers.

>         (simple_tree_swap_info): Removed.

>         (remap_split_decl_to_dummy): Likewise.

>         (record_argument_state_1): New function.

>         (record_argument_state): Likewise.

>         (ipa_param_body_adjustments::modify_call_stmt): New parameter

>         orig_stmt.  Do not work with dummy decls, save necessary info about

>         changes to ipa_edge_modifications.

>         (ipa_param_body_adjustments::modify_gimple_stmt): New parameter

>         orig_stmt, pass it to modify_call_stmt.

>         (ipa_param_body_adjustments::modify_cfun_body): Adjust call to

>         modify_gimple_stmt.

>         * tree-inline.c (remap_gimple_stmt): Do not copy dead statements,

>         reset dead debug statements, pass original statement to

>         modify_gimple_stmt.

>         (copy_phis_for_bb): Do not copy dead PHI nodes.

>         (expand_call_inline): Do not remap performed_splits.

>         (update_clone_info): Likewise.

>

> gcc/testsuite/ChangeLog:

>

> 2021-03-22  Martin Jambor  <mjambor@suse.cz>

>

>         PR ipa/93385

>         * gcc.dg/ipa/pr93385.c: New test.

>         * gcc.dg/ipa/ipa-sra-23.c: Likewise.

>         * gcc.dg/ipa/ipa-sra-24.c: Likewise.

>         * g++.dg/ipa/ipa-sra-4.C: Likewise.

> ---

>  gcc/cgraph.c                          |  22 +-

>  gcc/cgraphclones.c                    |   3 -

>  gcc/ipa-param-manipulation.c          | 916 ++++++++++++++++----------

>  gcc/ipa-param-manipulation.h          |  92 ++-

>  gcc/symtab-clones.h                   |  15 +-

>  gcc/testsuite/g++.dg/ipa/ipa-sra-4.C  |  37 ++

>  gcc/testsuite/gcc.dg/ipa/ipa-sra-23.c |  24 +

>  gcc/testsuite/gcc.dg/ipa/ipa-sra-24.c |  20 +

>  gcc/testsuite/gcc.dg/ipa/pr93385.c    |  27 +

>  gcc/tree-inline.c                     | 121 +---

>  10 files changed, 721 insertions(+), 556 deletions(-)

>  create mode 100644 gcc/testsuite/g++.dg/ipa/ipa-sra-4.C

>  create mode 100644 gcc/testsuite/gcc.dg/ipa/ipa-sra-23.c

>  create mode 100644 gcc/testsuite/gcc.dg/ipa/ipa-sra-24.c

>  create mode 100644 gcc/testsuite/gcc.dg/ipa/pr93385.c

>

> diff --git a/gcc/cgraph.c b/gcc/cgraph.c

> index d7c78d518bc..d473da5a325 100644

> --- a/gcc/cgraph.c

> +++ b/gcc/cgraph.c

> @@ -1506,8 +1506,6 @@ cgraph_edge::redirect_call_stmt_to_callee (cgraph_edge *e)

>      }

>

>    clone_info *callee_info = clone_info::get (e->callee);

> -  clone_info *caller_info = clone_info::get (e->caller);

> -

>    if (symtab->dump_file)

>      {

>        fprintf (symtab->dump_file, "updating call of %s -> %s: ",

> @@ -1515,18 +1513,6 @@ cgraph_edge::redirect_call_stmt_to_callee (cgraph_edge *e)

>        print_gimple_stmt (symtab->dump_file, e->call_stmt, 0, dump_flags);

>        if (callee_info && callee_info->param_adjustments)

>         callee_info->param_adjustments->dump (symtab->dump_file);

> -      unsigned performed_len

> -       = caller_info ? vec_safe_length (caller_info->performed_splits) : 0;

> -      if (performed_len > 0)

> -       fprintf (symtab->dump_file, "Performed splits records:\n");

> -      for (unsigned i = 0; i < performed_len; i++)

> -       {

> -         ipa_param_performed_split *sm

> -           = &(*caller_info->performed_splits)[i];

> -         print_node_brief (symtab->dump_file, "  dummy_decl: ", sm->dummy_decl,

> -                           TDF_UID);

> -         fprintf (symtab->dump_file, ", unit_offset: %u\n", sm->unit_offset);

> -       }

>      }

>

>    if (ipa_param_adjustments *padjs

> @@ -1541,10 +1527,7 @@ cgraph_edge::redirect_call_stmt_to_callee (cgraph_edge *e)

>         remove_stmt_from_eh_lp (e->call_stmt);

>

>        tree old_fntype = gimple_call_fntype (e->call_stmt);

> -      new_stmt = padjs->modify_call (e->call_stmt,

> -                                    caller_info

> -                                    ? caller_info->performed_splits : NULL,

> -                                    e->callee->decl, false);

> +      new_stmt = padjs->modify_call (e, false);

>        cgraph_node *origin = e->callee;

>        while (origin->clone_of)

>         origin = origin->clone_of;

> @@ -1564,6 +1547,9 @@ cgraph_edge::redirect_call_stmt_to_callee (cgraph_edge *e)

>      }

>    else

>      {

> +      if (flag_checking

> +         && !fndecl_built_in_p (e->callee->decl, BUILT_IN_UNREACHABLE))

> +       ipa_verify_edge_has_no_modifications (e);

>        new_stmt = e->call_stmt;

>        gimple_call_set_fndecl (new_stmt, e->callee->decl);

>        update_stmt_fn (DECL_STRUCT_FUNCTION (e->caller->decl), new_stmt);

> diff --git a/gcc/cgraphclones.c b/gcc/cgraphclones.c

> index 9f86463b42d..7e463acab91 100644

> --- a/gcc/cgraphclones.c

> +++ b/gcc/cgraphclones.c

> @@ -414,9 +414,6 @@ cgraph_node::create_clone (tree new_decl, profile_count prof_count,

>    else if (info && info->param_adjustments)

>      clone_info::get_create (new_node)->param_adjustments

>          = info->param_adjustments;

> -  if (info && info->performed_splits)

> -    clone_info::get_create (new_node)->performed_splits

> -        = vec_safe_copy (info->performed_splits);

>    new_node->split_part = split_part;

>

>    FOR_EACH_VEC_ELT (redirect_callers, i, e)

> diff --git a/gcc/ipa-param-manipulation.c b/gcc/ipa-param-manipulation.c

> index 132bb24f76a..3e07fd72fe2 100644

> --- a/gcc/ipa-param-manipulation.c

> +++ b/gcc/ipa-param-manipulation.c

> @@ -62,6 +62,80 @@ static const char *ipa_param_op_names[IPA_PARAM_PREFIX_COUNT]

>       "IPA_PARAM_OP_NEW",

>       "IPA_PARAM_OP_SPLIT"};

>

> +/* Structure to hold declarations representing pass-through IPA-SRA splits.  In

> +   essence, it tells new index for a combination of original index and

> +   offset.  */

> +

> +struct pass_through_split_map

> +{

> +  /* Original argument index.  */

> +  unsigned base_index;

> +  /* Offset of the split part in the original argument.  */

> +  unsigned unit_offset;

> +  /* Index of the split part in the call statement - where clone

> +     materialization put it.  */

> +  int new_index;

> +};

> +

> +/* Information about some call statements that needs to be conveyed from clone

> +   materialization to edge redirection. */

> +

> +class ipa_edge_modification_info

> +{

> + public:

> +  ipa_edge_modification_info ()

> +    {}

> +

> +  /* Mapping of original argument indices to where those arguments sit in the

> +     call statement now or to a negative index if they were removed.  */

> +  auto_vec<int> index_map;

> +  /* Information about ISRA replacements put into the call statement at the

> +     clone materialization stages.  */

> +  auto_vec<pass_through_split_map> pass_through_map;

> +  /* Necessary adjustment to ipa_param_adjustments::m_always_copy_start when

> +     redirecting the call.  */

> +  int always_copy_delta = 0;

> +};

> +

> +/* Class for storing and retrieving summaries about cal statement

> +   modifications.  */

> +

> +class ipa_edge_modification_sum

> +  : public call_summary <ipa_edge_modification_info *>

> +{

> + public:

> +  ipa_edge_modification_sum (symbol_table *table)

> +    : call_summary<ipa_edge_modification_info *> (table)

> +  {

> +  }

> +

> +  /* Hook that is called by summary when an edge is duplicated.  */

> +

> +  virtual void duplicate (cgraph_edge *,

> +                         cgraph_edge *,

> +                         ipa_edge_modification_info *old_info,

> +                         ipa_edge_modification_info *new_info)

> +  {

> +    new_info->index_map.safe_splice (old_info->index_map);

> +    new_info->pass_through_map.safe_splice (old_info->pass_through_map);

> +    new_info->always_copy_delta = old_info->always_copy_delta;

> +  }

> +};

> +

> +/* Call summary to store information about edges which have had their arguments

> +   partially modified already.  */

> +

> +static ipa_edge_modification_sum *ipa_edge_modifications;

> +

> +/* Fail compilation if CS has any summary associated with it in

> +   ipa_edge_modifications.  */

> +

> +DEBUG_FUNCTION void

> +ipa_verify_edge_has_no_modifications (cgraph_edge *cs)

> +{

> +  gcc_assert (!ipa_edge_modifications || !ipa_edge_modifications->get (cs));

> +}

> +

>  /* Fill an empty vector ARGS with PARM_DECLs representing formal parameters of

>     FNDECL.  The function should not be called during LTO WPA phase except for

>     thunks (or functions with bodies streamed in). */

> @@ -459,147 +533,46 @@ isra_get_ref_base_and_offset (tree expr, tree *base_p, unsigned *unit_offset_p)

>    return true;

>  }

>

> -/* Return true if EXPR describes a transitive split (i.e. one that happened for

> -   both the caller and the callee) as recorded in PERFORMED_SPLITS.  In that

> -   case, store index of the respective record in PERFORMED_SPLITS into

> -   *SM_IDX_P and the unit offset from all handled components in EXPR into

> -   *UNIT_OFFSET_P.  */

> -

> -static bool

> -transitive_split_p (vec<ipa_param_performed_split, va_gc> *performed_splits,

> -                   tree expr, unsigned *sm_idx_p, unsigned *unit_offset_p)

> -{

> -  tree base;

> -  if (!isra_get_ref_base_and_offset (expr, &base, unit_offset_p))

> -    return false;

> -

> -  if (TREE_CODE (base) == SSA_NAME)

> -    {

> -      base = SSA_NAME_VAR (base);

> -      if (!base)

> -       return false;

> -    }

> -

> -  unsigned len = vec_safe_length (performed_splits);

> -  for (unsigned i = 0 ; i < len; i++)

> -    {

> -      ipa_param_performed_split *sm = &(*performed_splits)[i];

> -      if (sm->dummy_decl == base)

> -       {

> -         *sm_idx_p = i;

> -         return true;

> -       }

> -    }

> -  return false;

> -}

> -

> -/* Structure to hold declarations representing transitive IPA-SRA splits.  In

> -   essence, if we need to pass UNIT_OFFSET of a parameter which originally has

> -   number BASE_INDEX, we should pass down REPL.  */

> -

> -struct transitive_split_map

> -{

> -  tree repl;

> -  unsigned base_index;

> -  unsigned unit_offset;

> -};

> -

> -/* If call STMT contains any parameters representing transitive splits as

> -   described by PERFORMED_SPLITS, return the number of extra parameters that

> -   were addded during clone materialization and fill in INDEX_MAP with adjusted

> -   indices of corresponding original parameters and TRANS_MAP with description

> -   of all transitive replacement descriptions.  Otherwise return zero. */

> -

> -static unsigned

> -init_transitive_splits (vec<ipa_param_performed_split, va_gc> *performed_splits,

> -                       gcall *stmt, vec <unsigned> *index_map,

> -                       auto_vec <transitive_split_map> *trans_map)

> -{

> -  unsigned phony_arguments = 0;

> -  unsigned stmt_idx = 0, base_index = 0;

> -  unsigned nargs = gimple_call_num_args (stmt);

> -  while (stmt_idx < nargs)

> -    {

> -      unsigned unit_offset_delta;

> -      tree base_arg = gimple_call_arg (stmt, stmt_idx);

> -

> -      if (phony_arguments > 0)

> -       index_map->safe_push (stmt_idx);

> -

> -      unsigned sm_idx;

> -      stmt_idx++;

> -      if (transitive_split_p (performed_splits, base_arg, &sm_idx,

> -                             &unit_offset_delta))

> -       {

> -         if (phony_arguments == 0)

> -           /* We have optimistically avoided constructing index_map do far but

> -              now it is clear it will be necessary, so let's create the easy

> -              bit we skipped until now.  */

> -           for (unsigned k = 0; k < stmt_idx; k++)

> -             index_map->safe_push (k);

> -

> -         tree dummy = (*performed_splits)[sm_idx].dummy_decl;

> -         for (unsigned j = sm_idx; j < performed_splits->length (); j++)

> -           {

> -             ipa_param_performed_split *caller_split

> -               = &(*performed_splits)[j];

> -             if (caller_split->dummy_decl != dummy)

> -               break;

> -

> -             tree arg = gimple_call_arg (stmt, stmt_idx);

> -             struct transitive_split_map tsm;

> -             tsm.repl = arg;

> -             tsm.base_index = base_index;

> -             if (caller_split->unit_offset >= unit_offset_delta)

> -               {

> -                 tsm.unit_offset

> -                   = (caller_split->unit_offset - unit_offset_delta);

> -                 trans_map->safe_push (tsm);

> -               }

> -

> -             phony_arguments++;

> -             stmt_idx++;

> -           }

> -       }

> -      base_index++;

> -    }

> -  return phony_arguments;

> -}

> -

> -/* Modify actual arguments of a function call in statement STMT, assuming it

> -   calls CALLEE_DECL.  CALLER_ADJ must be the description of parameter

> -   adjustments of the caller or NULL if there are none.  Return the new

> -   statement that replaced the old one.  When invoked, cfun and

> -   current_function_decl have to be set to the caller.  */

> +/* Modify actual arguments of a function call in statement currently belonging

> +   to CS, and make it call CS->callee->decl.  Return the new statement that

> +   replaced the old one.  When invoked, cfun and current_function_decl have to

> +   be set to the caller.  */

>

>  gcall *

> -ipa_param_adjustments::modify_call (gcall *stmt,

> -                                   vec<ipa_param_performed_split,

> -                                       va_gc> *performed_splits,

> -                                   tree callee_decl, bool update_references)

> +ipa_param_adjustments::modify_call (cgraph_edge *cs,

> +                                   bool update_references)

>  {

> +  gcall *stmt = cs->call_stmt;

> +  tree callee_decl = cs->callee->decl;

> +

> +  ipa_edge_modification_info *mod_info

> +    = ipa_edge_modifications ? ipa_edge_modifications->get (cs) : NULL;

> +  if (mod_info && symtab->dump_file)

> +    {

> +      fprintf (symtab->dump_file, "Information about pre-exiting "

> +              "modifications.\n  Index map:");

> +      unsigned idx_len = mod_info->index_map.length ();

> +      for (unsigned i = 0; i < idx_len; i++)

> +       fprintf (symtab->dump_file, " %i", mod_info->index_map[i]);

> +      fprintf (symtab->dump_file, "\n  Pass-through split map: ");

> +      unsigned ptm_len = mod_info->pass_through_map.length ();

> +      for (unsigned i = 0; i < ptm_len; i++)

> +       fprintf (symtab->dump_file,

> +                " (base_index: %u, offset: %u, new_index: %i)",

> +                mod_info->pass_through_map[i].base_index,

> +                mod_info->pass_through_map[i].unit_offset,

> +                mod_info->pass_through_map[i].new_index);

> +      fprintf (symtab->dump_file, "\n  Always-copy delta: %i\n",

> +              mod_info->always_copy_delta);

> +    }

> +

>    unsigned len = vec_safe_length (m_adj_params);

>    auto_vec<tree, 16> vargs (len);

> -  tree old_decl = gimple_call_fndecl (stmt);

>    unsigned old_nargs = gimple_call_num_args (stmt);

> +  unsigned orig_nargs = mod_info ? mod_info->index_map.length () : old_nargs;

>    auto_vec<bool, 16> kept (old_nargs);

>    kept.quick_grow_cleared (old_nargs);

>

> -  auto_vec <unsigned, 16> index_map;

> -  auto_vec <transitive_split_map> trans_map;

> -  bool transitive_remapping = false;

> -

> -  if (performed_splits)

> -    {

> -      unsigned removed = init_transitive_splits (performed_splits,

> -                                                stmt, &index_map, &trans_map);

> -      if (removed > 0)

> -       {

> -         transitive_remapping = true;

> -         old_nargs -= removed;

> -       }

> -    }

> -

>    cgraph_node *current_node = cgraph_node::get (current_function_decl);

>    if (update_references)

>      current_node->remove_stmt_references (stmt);

> @@ -612,13 +585,16 @@ ipa_param_adjustments::modify_call (gcall *stmt,

>        ipa_adjusted_param *apm = &(*m_adj_params)[i];

>        if (apm->op == IPA_PARAM_OP_COPY)

>         {

> -         unsigned index = apm->base_index;

> -         if (index >= old_nargs)

> +         int index = apm->base_index;

> +         if ((unsigned) index >= orig_nargs)

>             /* Can happen if the original call has argument mismatch,

>                ignore.  */

>             continue;

> -         if (transitive_remapping)

> -           index = index_map[apm->base_index];

> +         if (mod_info)

> +           {

> +             index = mod_info->index_map[apm->base_index];

> +             gcc_assert (index >= 0);

> +           }

>

>           tree arg = gimple_call_arg (stmt, index);

>

> @@ -636,14 +612,17 @@ ipa_param_adjustments::modify_call (gcall *stmt,

>          materialization.  */

>        gcc_assert (apm->op == IPA_PARAM_OP_SPLIT);

>

> -      /* We have to handle transitive changes differently using the maps we

> -        have created before.  So look into them first.  */

> +      /* We have to handle pass-through changes differently using the map

> +        clone materialziation might have left behind.  */

>        tree repl = NULL_TREE;

> -      for (unsigned j = 0; j < trans_map.length (); j++)

> -       if (trans_map[j].base_index == apm->base_index

> -           && trans_map[j].unit_offset == apm->unit_offset)

> +      unsigned ptm_len = mod_info ? mod_info->pass_through_map.length () : 0;

> +      for (unsigned j = 0; j < ptm_len; j++)

> +       if (mod_info->pass_through_map[j].base_index == apm->base_index

> +           && mod_info->pass_through_map[j].unit_offset == apm->unit_offset)

>           {

> -           repl = trans_map[j].repl;

> +           int repl_idx = mod_info->pass_through_map[j].new_index;

> +           gcc_assert (repl_idx >= 0);

> +           repl = gimple_call_arg (stmt, repl_idx);

>             break;

>           }

>        if (repl)

> @@ -652,12 +631,15 @@ ipa_param_adjustments::modify_call (gcall *stmt,

>           continue;

>         }

>

> -      unsigned index = apm->base_index;

> -      if (index >= old_nargs)

> +      int index = apm->base_index;

> +      if ((unsigned) index >= orig_nargs)

>         /* Can happen if the original call has argument mismatch, ignore.  */

>         continue;

> -      if (transitive_remapping)

> -       index = index_map[apm->base_index];

> +      if (mod_info)

> +       {

> +         index = mod_info->index_map[apm->base_index];

> +         gcc_assert (index >= 0);

> +       }

>        tree base = gimple_call_arg (stmt, index);

>

>        /* We create a new parameter out of the value of the old one, we can

> @@ -773,8 +755,16 @@ ipa_param_adjustments::modify_call (gcall *stmt,

>      }

>

>    if (m_always_copy_start >= 0)

> -    for (unsigned i = m_always_copy_start; i < old_nargs; i++)

> -      vargs.safe_push (gimple_call_arg (stmt, i));

> +    {

> +      int always_copy_start = m_always_copy_start;

> +      if (mod_info)

> +       {

> +         always_copy_start += mod_info->always_copy_delta;

> +         gcc_assert (always_copy_start >= 0);

> +       }

> +      for (unsigned i = always_copy_start; i < old_nargs; i++)

> +       vargs.safe_push (gimple_call_arg (stmt, i));

> +    }

>

>    /* For optimized away parameters, add on the caller side

>       before the call

> @@ -782,6 +772,7 @@ ipa_param_adjustments::modify_call (gcall *stmt,

>       stmts and associate D#X with parm in decl_debug_args_lookup

>       vector to say for debug info that if parameter parm had been passed,

>       it would have value parm_Y(D).  */

> +  tree old_decl = gimple_call_fndecl (stmt);

>    if (MAY_HAVE_DEBUG_BIND_STMTS && old_decl && callee_decl)

>      {

>        vec<tree, va_gc> **debug_args = NULL;

> @@ -799,13 +790,17 @@ ipa_param_adjustments::modify_call (gcall *stmt,

>         {

>           if (!is_gimple_reg (old_parm) || kept[i])

>             continue;

> -         tree origin = DECL_ORIGIN (old_parm);

>           tree arg;

> -         if (transitive_remapping)

> -           arg = gimple_call_arg (stmt, index_map[i]);

> +         if (mod_info)

> +           {

> +             if (mod_info->index_map[i] < 0)

> +               continue;

> +             arg = gimple_call_arg (stmt, mod_info->index_map[i]);

> +           }

>           else

>             arg = gimple_call_arg (stmt, i);

>

> +         tree origin = DECL_ORIGIN (old_parm);

>           if (!useless_type_conversion_p (TREE_TYPE (origin), TREE_TYPE (arg)))

>             {

>               if (!fold_convertible_p (TREE_TYPE (origin), arg))

> @@ -905,6 +900,9 @@ ipa_param_adjustments::modify_call (gcall *stmt,

>         gsi_prev (&gsi);

>        }

>      while (gsi_stmt (gsi) != gsi_stmt (prev_gsi));

> +

> +  if (mod_info)

> +    ipa_edge_modifications->remove (cs);

>    return new_stmt;

>  }

>

> @@ -927,13 +925,11 @@ ipa_param_adjustments::debug ()

>    dump (stderr);

>  }

>

> -/* Register that REPLACEMENT should replace parameter described in APM and

> -   optionally as DUMMY to mark transitive splits across calls.  */

> +/* Register that REPLACEMENT should replace parameter described in APM.  */

>

>  void

>  ipa_param_body_adjustments::register_replacement (ipa_adjusted_param *apm,

> -                                                 tree replacement,

> -                                                 tree dummy)

> +                                                 tree replacement)

>  {

>    gcc_checking_assert (apm->op == IPA_PARAM_OP_SPLIT

>                        || apm->op == IPA_PARAM_OP_NEW);

> @@ -941,7 +937,6 @@ ipa_param_body_adjustments::register_replacement (ipa_adjusted_param *apm,

>    ipa_param_body_replacement psr;

>    psr.base = m_oparms[apm->prev_clone_index];

>    psr.repl = replacement;

> -  psr.dummy = dummy;

>    psr.unit_offset = apm->unit_offset;

>    m_replacements.safe_push (psr);

>  }

> @@ -970,6 +965,97 @@ ipa_param_body_adjustments::carry_over_param (tree t)

>    return new_parm;

>  }

>

> +/* Return true if BLOCKS_TO_COPY is NULL or if PHI has an argument ARG in

> +   position that corresponds to an edge that is coming from a block that has

> +   the corresponding bit set in BLOCKS_TO_COPY.  */

> +

> +static bool

> +phi_arg_will_live_p (gphi *phi, bitmap blocks_to_copy, tree arg)

> +{

> +  bool arg_will_survive = false;

> +  if (!blocks_to_copy)

> +    arg_will_survive = true;

> +  else

> +    for (unsigned i = 0; i < gimple_phi_num_args (phi); i++)

> +      if (gimple_phi_arg_def (phi, i) == arg

> +         && bitmap_bit_p (blocks_to_copy,

> +                          gimple_phi_arg_edge (phi, i)->src->index))

> +       {

> +         arg_will_survive = true;

> +         break;

> +       }

> +  return arg_will_survive;

> +}

> +

> +/* Populate m_dead_stmts given that DEAD_PARAM is going to be removed without

> +   any replacement or splitting.  REPL is the replacement VAR_SECL to base any

> +   remaining uses of a removed parameter on.  */

> +

> +void

> +ipa_param_body_adjustments::mark_dead_statements (tree dead_param)

> +{

> +  /* Current IPA analyses which remove unused parameters never remove a

> +     non-gimple register ones which have any use except as parameters in other

> +     calls, so we can safely leve them as they are.  */

> +  if (!is_gimple_reg (dead_param))

> +    return;

> +  tree parm_ddef = ssa_default_def (m_id->src_cfun, dead_param);

> +  if (!parm_ddef || has_zero_uses (parm_ddef))

> +    return;

> +

> +  auto_vec<tree, 4> stack;

> +  m_dead_ssas.add (parm_ddef);

> +  stack.safe_push (parm_ddef);

> +  while (!stack.is_empty ())

> +    {

> +      tree t = stack.pop ();

> +

> +      imm_use_iterator imm_iter;

> +      gimple *stmt;

> +

> +      insert_decl_map (m_id, t, error_mark_node);

> +      FOR_EACH_IMM_USE_STMT (stmt, imm_iter, t)

> +       {

> +         if (is_gimple_call (stmt)

> +             || (m_id->blocks_to_copy

> +                 && !bitmap_bit_p (m_id->blocks_to_copy,

> +                                   gimple_bb (stmt)->index)))

> +           continue;

> +

> +         if (is_gimple_debug (stmt))

> +           {

> +             m_dead_stmts.add (stmt);

> +             gcc_assert (gimple_debug_bind_p (stmt));

> +           }

> +         else if (gimple_code (stmt) == GIMPLE_PHI)

> +           {

> +             gphi *phi = as_a <gphi *> (stmt);

> +             if (phi_arg_will_live_p (phi, m_id->blocks_to_copy, t))

> +               {

> +                 m_dead_stmts.add (phi);

> +                 tree res = gimple_phi_result (phi);

> +                 if (!m_dead_ssas.add (res))

> +                   stack.safe_push (res);

> +               }

> +           }

> +         else if (is_gimple_assign (stmt))

> +           {

> +             m_dead_stmts.add (stmt);

> +             if (!gimple_clobber_p (stmt))

> +               {

> +                 tree lhs = gimple_assign_lhs (stmt);

> +                 gcc_assert (TREE_CODE (lhs) == SSA_NAME);

> +                 if (!m_dead_ssas.add (lhs))

> +                   stack.safe_push (lhs);

> +               }

> +           }

> +         else

> +           /* IPA-SRA does not analyze other types of statements.  */

> +           gcc_unreachable ();

> +       }

> +    }

> +}

> +

>  /* Common initialization performed by all ipa_param_body_adjustments

>     constructors.  OLD_FNDECL is the declaration we take original arguments

>     from, (it may be the same as M_FNDECL).  VARS, if non-NULL, is a pointer to

> @@ -1003,9 +1089,9 @@ ipa_param_body_adjustments::common_initialization (tree old_fndecl,

>    auto_vec<bool, 16> kept;

>    kept.reserve_exact (m_oparms.length ());

>    kept.quick_grow_cleared (m_oparms.length ());

> -  auto_vec<tree, 16> isra_dummy_decls;

> -  isra_dummy_decls.reserve_exact (m_oparms.length ());

> -  isra_dummy_decls.quick_grow_cleared (m_oparms.length ());

> +  auto_vec<bool, 16> split;

> +  split.reserve_exact (m_oparms.length ());

> +  split.quick_grow_cleared (m_oparms.length ());

>

>    unsigned adj_len = vec_safe_length (m_adj_params);

>    m_method2func = ((TREE_CODE (TREE_TYPE (m_fndecl)) == METHOD_TYPE)

> @@ -1051,35 +1137,8 @@ ipa_param_body_adjustments::common_initialization (tree old_fndecl,

>           if (apm->op == IPA_PARAM_OP_SPLIT)

>             {

>               m_split_modifications_p = true;

> -

> -             if (m_id)

> -               {

> -                 tree dummy_decl;

> -                 if (!isra_dummy_decls[prev_index])

> -                   {

> -                     dummy_decl = copy_decl_to_var (m_oparms[prev_index],

> -                                                    m_id);

> -                     /* Any attempt to remap this dummy in this particular

> -                        instance of clone materialization should yield

> -                        itself.  */

> -                     insert_decl_map (m_id, dummy_decl, dummy_decl);

> -

> -                     DECL_CHAIN (dummy_decl) = *vars;

> -                     *vars = dummy_decl;

> -                     isra_dummy_decls[prev_index] = dummy_decl;

> -                   }

> -                 else

> -                   dummy_decl = isra_dummy_decls[prev_index];

> -

> -                 register_replacement (apm, new_parm, dummy_decl);

> -                 ipa_param_performed_split ps;

> -                 ps.dummy_decl = dummy_decl;

> -                 ps.unit_offset = apm->unit_offset;

> -                 vec_safe_push (clone_info::get_create

> -                                  (m_id->dst_node)->performed_splits, ps);

> -               }

> -             else

> -               register_replacement (apm, new_parm);

> +             split[prev_index] = true;

> +             register_replacement (apm, new_parm);

>             }

>          }

>        else

> @@ -1106,13 +1165,16 @@ ipa_param_body_adjustments::common_initialization (tree old_fndecl,

>           {

>             if (!m_id->decl_map->get (m_oparms[i]))

>               {

> -               /* TODO: Perhaps at least aggregate-type params could re-use

> -                  their isra_dummy_decl here?  */

>                 tree var = copy_decl_to_var (m_oparms[i], m_id);

>                 insert_decl_map (m_id, m_oparms[i], var);

>                 /* Declare this new variable.  */

>                 DECL_CHAIN (var) = *vars;

>                 *vars = var;

> +

> +               /* If this is not a split but a real removal, init hash sets

> +                  that will guide what not to copy to the new body.  */

> +               if (!split[i])

> +                 mark_dead_statements (m_oparms[i]);

>               }

>           }

>         else

> @@ -1169,9 +1231,10 @@ ipa_param_body_adjustments

>  ::ipa_param_body_adjustments (vec<ipa_adjusted_param, va_gc> *adj_params,

>                               tree fndecl)

>    : m_adj_params (adj_params), m_adjustments (NULL), m_reset_debug_decls (),

> -    m_split_modifications_p (false), m_fndecl (fndecl), m_id (NULL),

> -    m_oparms (), m_new_decls (), m_new_types (), m_replacements (),

> -    m_removed_decls (), m_removed_map (), m_method2func (false)

> +    m_split_modifications_p (false), m_dead_stmts (), m_dead_ssas (),

> +    m_fndecl (fndecl), m_id (NULL), m_oparms (), m_new_decls (),

> +    m_new_types (), m_replacements (), m_removed_decls (), m_removed_map (),

> +    m_method2func (false), m_new_call_arg_modification_info (false)

>  {

>    common_initialization (fndecl, NULL, NULL);

>  }

> @@ -1185,10 +1248,10 @@ ipa_param_body_adjustments

>  ::ipa_param_body_adjustments (ipa_param_adjustments *adjustments,

>                               tree fndecl)

>    : m_adj_params (adjustments->m_adj_params), m_adjustments (adjustments),

> -    m_reset_debug_decls (), m_split_modifications_p (false), m_fndecl (fndecl),

> -    m_id (NULL), m_oparms (), m_new_decls (), m_new_types (),

> -    m_replacements (), m_removed_decls (), m_removed_map (),

> -    m_method2func (false)

> +    m_reset_debug_decls (), m_split_modifications_p (false), m_dead_stmts (),

> +    m_dead_ssas (), m_fndecl (fndecl), m_id (NULL), m_oparms (), m_new_decls (),

> +    m_new_types (), m_replacements (), m_removed_decls (), m_removed_map (),

> +    m_method2func (false), m_new_call_arg_modification_info (false)

>  {

>    common_initialization (fndecl, NULL, NULL);

>  }

> @@ -1208,9 +1271,10 @@ ipa_param_body_adjustments

>                               copy_body_data *id, tree *vars,

>                               vec<ipa_replace_map *, va_gc> *tree_map)

>    : m_adj_params (adjustments->m_adj_params), m_adjustments (adjustments),

> -    m_reset_debug_decls (), m_split_modifications_p (false), m_fndecl (fndecl),

> -    m_id (id), m_oparms (), m_new_decls (), m_new_types (), m_replacements (),

> -    m_removed_decls (), m_removed_map (), m_method2func (false)

> +    m_reset_debug_decls (), m_split_modifications_p (false), m_dead_stmts (),

> +    m_dead_ssas (),m_fndecl (fndecl), m_id (id), m_oparms (), m_new_decls (),

> +    m_new_types (), m_replacements (), m_removed_decls (), m_removed_map (),

> +    m_method2func (false), m_new_call_arg_modification_info (false)

>  {

>    common_initialization (old_fndecl, vars, tree_map);

>  }

> @@ -1498,218 +1562,338 @@ ipa_param_body_adjustments::modify_assignment (gimple *stmt,

>    return any;

>  }

>

> -/* Data passed to remap_split_decl_to_dummy through walk_tree.  */

> +/* Record information about what modifications to call arguments have already

> +   been done by clone materialization into a summary describing CS.  The

> +   information is stored in NEW_INDEX_MAP, NEW_PT_MAP and NEW_ALWAYS_COPY_DELTA

> +   and correspond to equivalent fields in ipa_edge_modification_info.  Return

> +   the edge summary.  */

> +

> +static ipa_edge_modification_info *

> +record_argument_state_1 (cgraph_edge *cs, const vec<int> &new_index_map,

> +                        const vec<pass_through_split_map> &new_pt_map,

> +                        int new_always_copy_delta)

>

> -struct simple_tree_swap_info

>  {

> -  /* Change FROM to TO.  */

> -  tree from, to;

> -  /* And set DONE to true when doing so.  */

> -  bool done;

> -};

> +  ipa_edge_modification_info *sum = ipa_edge_modifications->get_create (cs);

>

> -/* Simple remapper to remap a split parameter to the same expression based on a

> -   special dummy decl so that edge redirections can detect transitive splitting

> -   and finish them.  */

> -

> -static tree

> -remap_split_decl_to_dummy (tree *tp, int *walk_subtrees, void *data)

> -{

> -  tree t = *tp;

> -

> -  if (DECL_P (t) || TREE_CODE (t) == SSA_NAME)

> +  unsigned len = sum->pass_through_map.length ();

> +  for (unsigned i = 0; i < len; i++)

>      {

> -      struct simple_tree_swap_info *swapinfo

> -       = (struct simple_tree_swap_info *) data;

> -      if (t == swapinfo->from

> -         || (TREE_CODE (t) == SSA_NAME

> -             && SSA_NAME_VAR (t) == swapinfo->from))

> -       {

> -         *tp = swapinfo->to;

> -         swapinfo->done = true;

> -       }

> -      *walk_subtrees = 0;

> +      unsigned oldnew = sum->pass_through_map[i].new_index;

> +      sum->pass_through_map[i].new_index = new_index_map[oldnew];

> +    }

> +

> +  len = sum->index_map.length ();

> +  if (len > 0)

> +    {

> +      unsigned nptlen = new_pt_map.length ();

> +      for (unsigned j = 0; j < nptlen; j++)

> +       {

> +         int inverse = -1;

> +         for (unsigned i = 0; i < len ; i++)

> +           if ((unsigned) sum->index_map[i] == new_pt_map[j].base_index)

> +           {

> +             inverse = i;

> +             break;

> +           }

> +         gcc_assert (inverse >= 0);

> +         pass_through_split_map ptm_item;

> +

> +         ptm_item.base_index = inverse;

> +         ptm_item.unit_offset = new_pt_map[j].unit_offset;

> +         ptm_item.new_index = new_pt_map[j].new_index;

> +         sum->pass_through_map.safe_push (ptm_item);

> +       }

> +

> +      for (unsigned i = 0; i < len; i++)

> +       {

> +         int idx = sum->index_map[i];

> +         if (idx < 0)

> +           continue;

> +         sum->index_map[i] = new_index_map[idx];

> +       }

>      }

> -  else if (TYPE_P (t))

> -      *walk_subtrees = 0;

>    else

> -    *walk_subtrees = 1;

> -  return NULL_TREE;

> +    {

> +      sum->pass_through_map.safe_splice (new_pt_map);

> +      sum->index_map.safe_splice (new_index_map);

> +    }

> +  sum->always_copy_delta += new_always_copy_delta;

> +  return sum;

>  }

>

> +/* Record information about what modifications to call arguments have already

> +   been done by clone materialization into a summary of an edge describing the

> +   call in this clone and all its clones.  NEW_INDEX_MAP, NEW_PT_MAP and

> +   NEW_ALWAYS_COPY_DELTA have the same meaning as record_argument_state_1.

> +

> +   In order to associate the info with the right edge summaries, we need

> +   address of the ORIG_STMT in the function from which we are cloning (because

> +   the edges have not yet been re-assigned to the new statement that has just

> +   been created) and ID, the structure governing function body copying.  */

> +

> +static void

> +record_argument_state (copy_body_data *id, gimple *orig_stmt,

> +                      const vec<int> &new_index_map,

> +                      const vec<pass_through_split_map> &new_pt_map,

> +                      int new_always_copy_delta)

> +{

> +  if (!ipa_edge_modifications)

> +    ipa_edge_modifications = new ipa_edge_modification_sum (symtab);

> +

> +  struct cgraph_node *this_node = id->dst_node;

> +  ipa_edge_modification_info *first_sum = NULL;

> +  cgraph_edge *cs = this_node->get_edge (orig_stmt);

> +  if (cs)

> +    first_sum = record_argument_state_1 (cs, new_index_map, new_pt_map,

> +                                        new_always_copy_delta);

> +  else

> +    gcc_assert (this_node->clones);

> +

> +  if (!this_node->clones)

> +    return;

> +  for (cgraph_node *subclone = this_node->clones; subclone != this_node;)

> +    {

> +      cs = subclone->get_edge (orig_stmt);

> +      if (cs)

> +       {

> +         if (!first_sum)

> +           first_sum = record_argument_state_1 (cs, new_index_map, new_pt_map,

> +                                                new_always_copy_delta);

> +         else

> +           {

> +             ipa_edge_modification_info *s2

> +               = ipa_edge_modifications->get_create (cs);

> +             s2->index_map.truncate (0);

> +             s2->index_map.safe_splice (first_sum->index_map);

> +             s2->pass_through_map.truncate (0);

> +             s2->pass_through_map.safe_splice (first_sum->pass_through_map);

> +             s2->always_copy_delta = first_sum->always_copy_delta;

> +           }

> +       }

> +      else

> +       gcc_assert (subclone->clones);

> +

> +      if (subclone->clones)

> +       subclone = subclone->clones;

> +      else if (subclone->next_sibling_clone)

> +       subclone = subclone->next_sibling_clone;

> +      else

> +       {

> +         while (subclone != this_node && !subclone->next_sibling_clone)

> +           subclone = subclone->clone_of;

> +         if (subclone != this_node)

> +           subclone = subclone->next_sibling_clone;

> +       }

> +    }

> +}

>

>  /* If the call statement pointed at by STMT_P contains any expressions that

>     need to replaced with a different one as noted by ADJUSTMENTS, do so.  f the

>     statement needs to be rebuilt, do so.  Return true if any modifications have

> -   been performed.

> +   been performed.  ORIG_STMT, if not NULL, is the original statement in the

> +   function that is being cloned from, which at this point can be used to look

> +   up call_graph edges.

>

>     If the method is invoked as a part of IPA clone materialization and if any

> -   parameter split is transitive, i.e. it applies to the functin that is being

> -   modified and also to the callee of the statement, replace the parameter

> -   passed to old callee with an equivalent expression based on a dummy decl

> -   followed by PARM_DECLs representing the actual replacements.  The actual

> -   replacements will be then converted into SSA_NAMEs and then

> -   ipa_param_adjustments::modify_call will find the appropriate ones and leave

> -   only those in the call.  */

> +   parameter split is pass-through, i.e. it applies to the functin that is

> +   being modified and also to the callee of the statement, replace the

> +   parameter passed to old callee with all of the replacement a callee might

> +   possibly want and record the performed argument modifications in

> +   ipa_edge_modifications.  Likewise if any argument has already been left out

> +   because it is not necessary.  */

>

>  bool

> -ipa_param_body_adjustments::modify_call_stmt (gcall **stmt_p)

> +ipa_param_body_adjustments::modify_call_stmt (gcall **stmt_p,

> +                                             gimple *orig_stmt)

>  {

> -  gcall *stmt = *stmt_p;

>    auto_vec <unsigned, 4> pass_through_args;

>    auto_vec <unsigned, 4> pass_through_pbr_indices;

> +  auto_vec <HOST_WIDE_INT, 4> pass_through_offsets;

> +  gcall *stmt = *stmt_p;

> +  unsigned nargs = gimple_call_num_args (stmt);

> +  bool recreate = false;

>

> -  if (m_split_modifications_p && m_id)

> +  for (unsigned i = 0; i < gimple_call_num_args (stmt); i++)

>      {

> -      for (unsigned i = 0; i < gimple_call_num_args (stmt); i++)

> +      tree t = gimple_call_arg (stmt, i);

> +      gcc_assert (TREE_CODE (t) != BIT_FIELD_REF

> +                 && TREE_CODE (t) != IMAGPART_EXPR

> +                 && TREE_CODE (t) != REALPART_EXPR);

> +

> +      if (TREE_CODE (t) == SSA_NAME

> +         && m_dead_ssas.contains (t))

> +       recreate = true;

> +

> +      if (!m_split_modifications_p)

> +       continue;

> +

> +      tree base;

> +      unsigned agg_arg_offset;

> +      if (!isra_get_ref_base_and_offset (t, &base, &agg_arg_offset))

> +       continue;

> +

> +      bool by_ref = false;

> +      if (TREE_CODE (base) == SSA_NAME)

>         {

> -         tree t = gimple_call_arg (stmt, i);

> -         gcc_assert (TREE_CODE (t) != BIT_FIELD_REF

> -                     && TREE_CODE (t) != IMAGPART_EXPR

> -                     && TREE_CODE (t) != REALPART_EXPR);

> -

> -         tree base;

> -         unsigned unit_offset;

> -         if (!isra_get_ref_base_and_offset (t, &base, &unit_offset))

> +         if (!SSA_NAME_IS_DEFAULT_DEF (base))

>             continue;

> +         base = SSA_NAME_VAR (base);

> +         gcc_checking_assert (base);

> +         by_ref = true;

> +       }

> +      if (TREE_CODE (base) != PARM_DECL)

> +       continue;

>

> -         bool by_ref = false;

> -         if (TREE_CODE (base) == SSA_NAME)

> +      bool base_among_replacements = false;

> +      unsigned j, repl_list_len = m_replacements.length ();

> +      for (j = 0; j < repl_list_len; j++)

> +       {

> +         ipa_param_body_replacement *pbr = &m_replacements[j];

> +         if (pbr->base == base)

>             {

> -             if (!SSA_NAME_IS_DEFAULT_DEF (base))

> -               continue;

> -             base = SSA_NAME_VAR (base);

> -             gcc_checking_assert (base);

> -             by_ref = true;

> +             base_among_replacements = true;

> +             break;

>             }

> -         if (TREE_CODE (base) != PARM_DECL)

> -           continue;

> +       }

> +      if (!base_among_replacements)

> +       continue;

>

> -         bool base_among_replacements = false;

> -         unsigned j, repl_list_len = m_replacements.length ();

> -         for (j = 0; j < repl_list_len; j++)

> +      /* We still have to distinguish between an end-use that we have to

> +        transform now and a pass-through, which happens in the following

> +        two cases.  */

> +

> +      /* TODO: After we adjust ptr_parm_has_nonarg_uses to also consider

> +        &MEM_REF[ssa_name + offset], we will also have to detect that case

> +        here.    */

> +

> +      if (TREE_CODE (t) == SSA_NAME

> +         && SSA_NAME_IS_DEFAULT_DEF (t)

> +         && SSA_NAME_VAR (t)

> +         && TREE_CODE (SSA_NAME_VAR (t)) == PARM_DECL)

> +       {

> +         /* This must be a by_reference pass-through.  */

> +         recreate = true;

> +         gcc_assert (POINTER_TYPE_P (TREE_TYPE (t)));

> +         pass_through_args.safe_push (i);

> +         pass_through_pbr_indices.safe_push (j);

> +         pass_through_offsets.safe_push (agg_arg_offset);

> +       }

> +      else if (!by_ref && AGGREGATE_TYPE_P (TREE_TYPE (t)))

> +       {

> +         /* Currently IPA-SRA guarantees the aggregate access type

> +            exactly matches in this case.  So if it does not match, it is

> +            a pass-through argument that will be sorted out at edge

> +            redirection time.  */

> +         ipa_param_body_replacement *pbr

> +           = lookup_replacement_1 (base, agg_arg_offset);

> +

> +         if (!pbr

> +             || (TYPE_MAIN_VARIANT (TREE_TYPE (t))

> +                 != TYPE_MAIN_VARIANT (TREE_TYPE (pbr->repl))))

>             {

> -             ipa_param_body_replacement *pbr = &m_replacements[j];

> -             if (pbr->base == base)

> -               {

> -                 base_among_replacements = true;

> -                 break;

> -               }

> -           }

> -         if (!base_among_replacements)

> -           continue;

> -

> -         /* We still have to distinguish between an end-use that we have to

> -            transform now and a pass-through, which happens in the following

> -            two cases.  */

> -

> -         /* TODO: After we adjust ptr_parm_has_nonarg_uses to also consider

> -            &MEM_REF[ssa_name + offset], we will also have to detect that case

> -            here.    */

> -

> -         if (TREE_CODE (t) == SSA_NAME

> -             && SSA_NAME_IS_DEFAULT_DEF (t)

> -             && SSA_NAME_VAR (t)

> -             && TREE_CODE (SSA_NAME_VAR (t)) == PARM_DECL)

> -           {

> -             /* This must be a by_reference pass-through.  */

> -             gcc_assert (POINTER_TYPE_P (TREE_TYPE (t)));

> +             recreate = true;

>               pass_through_args.safe_push (i);

>               pass_through_pbr_indices.safe_push (j);

> -           }

> -         else if (!by_ref && AGGREGATE_TYPE_P (TREE_TYPE (t)))

> -           {

> -             /* Currently IPA-SRA guarantees the aggregate access type

> -                exactly matches in this case.  So if it does not match, it is

> -                a pass-through argument that will be sorted out at edge

> -                redirection time.  */

> -             ipa_param_body_replacement *pbr

> -               = lookup_replacement_1 (base, unit_offset);

> -

> -             if (!pbr

> -                 || (TYPE_MAIN_VARIANT (TREE_TYPE (t))

> -                     != TYPE_MAIN_VARIANT (TREE_TYPE (pbr->repl))))

> -               {

> -                 pass_through_args.safe_push (i);

> -                 pass_through_pbr_indices.safe_push (j);

> -               }

> +             pass_through_offsets.safe_push (agg_arg_offset);

>             }

>         }

>      }

>

> -  unsigned nargs = gimple_call_num_args (stmt);

> -  if (!pass_through_args.is_empty ())

> +  if (!recreate)

>      {

> -      auto_vec<tree, 16> vargs;

> -      unsigned pt_idx = 0;

> +      /* No need to rebuild the statement, let's just modify arguments

> +        and the LHS if/as appropriate.  */

> +      bool modified = false;

>        for (unsigned i = 0; i < nargs; i++)

>         {

> -         if (pt_idx < pass_through_args.length ()

> -             && i == pass_through_args[pt_idx])

> -           {

> -             unsigned j = pass_through_pbr_indices[pt_idx];

> -             pt_idx++;

> -             tree base = m_replacements[j].base;

> +         tree *t = gimple_call_arg_ptr (stmt, i);

> +         modified |= modify_expression (t, true);

> +       }

> +      if (gimple_call_lhs (stmt))

> +       {

> +         tree *t = gimple_call_lhs_ptr (stmt);

> +         modified |= modify_expression (t, false);

> +       }

> +      return modified;

> +    }

>

> -             /* Map base will get mapped to the special transitive-isra marker

> -                dummy decl. */

> -             struct simple_tree_swap_info swapinfo;

> -             swapinfo.from = base;

> -             swapinfo.to = m_replacements[j].dummy;

> -             swapinfo.done = false;

> -             tree arg = gimple_call_arg (stmt, i);

> -             walk_tree (&arg, remap_split_decl_to_dummy, &swapinfo, NULL);

> -             gcc_assert (swapinfo.done);

> -             vargs.safe_push (arg);

> -             /* Now let's push all replacements pertaining to this parameter

> -                so that all gimple register ones get correct SSA_NAMES.  Edge

> -                redirection will weed out the dummy argument as well as all

> -                unused replacements later.  */

> -             unsigned int repl_list_len = m_replacements.length ();

> -             for (; j < repl_list_len; j++)

> -               {

> -                 if (m_replacements[j].base != base)

> -                   break;

> -                 vargs.safe_push (m_replacements[j].repl);

> -               }

> +  auto_vec<int, 16> index_map;

> +  auto_vec<pass_through_split_map, 4> pass_through_map;

> +  auto_vec<tree, 16> vargs;

> +  int always_copy_delta = 0;

> +  unsigned pt_idx = 0;

> +  int new_arg_idx = 0;

> +  for (unsigned i = 0; i < nargs; i++)

> +    {

> +      if (pt_idx < pass_through_args.length ()

> +         && i == pass_through_args[pt_idx])

> +       {

> +         unsigned j = pass_through_pbr_indices[pt_idx];

> +         unsigned agg_arg_offset = pass_through_offsets[pt_idx];

> +         pt_idx++;

> +         always_copy_delta--;

> +         tree base = m_replacements[j].base;

> +

> +         /* In order to be put into SSA form, we have to push all replacements

> +            pertaining to this parameter as parameters to the call statement.

> +            Edge redirection will need to use edge summary to weed out the

> +            unnecessary ones.  */

> +         unsigned repl_list_len = m_replacements.length ();

> +         for (; j < repl_list_len; j++)

> +           {

> +             if (m_replacements[j].base != base)

> +               break;

> +             if (m_replacements[j].unit_offset < agg_arg_offset)

> +               continue;

> +             pass_through_split_map pt_map;

> +             pt_map.base_index = i;

> +             pt_map.unit_offset

> +               = m_replacements[j].unit_offset - agg_arg_offset;

> +             pt_map.new_index = new_arg_idx;

> +             pass_through_map.safe_push (pt_map);

> +             vargs.safe_push (m_replacements[j].repl);

> +             new_arg_idx++;

> +             always_copy_delta++;

> +           }

> +         index_map.safe_push (-1);

> +       }

> +      else

> +       {

> +         tree t = gimple_call_arg (stmt, i);

> +         if (TREE_CODE (t) == SSA_NAME

> +             && m_dead_ssas.contains (t))

> +           {

> +             always_copy_delta--;

> +             index_map.safe_push (-1);

>             }

>           else

>             {

> -             tree t = gimple_call_arg (stmt, i);

>               modify_expression (&t, true);

>               vargs.safe_push (t);

> +             index_map.safe_push (new_arg_idx);

> +             new_arg_idx++;

>             }

>         }

> -      gcall *new_stmt = gimple_build_call_vec (gimple_call_fn (stmt), vargs);

> -      if (gimple_has_location (stmt))

> -       gimple_set_location (new_stmt, gimple_location (stmt));

> -      gimple_call_set_chain (new_stmt, gimple_call_chain (stmt));

> -      gimple_call_copy_flags (new_stmt, stmt);

> -      if (tree lhs = gimple_call_lhs (stmt))

> -       {

> -         modify_expression (&lhs, false);

> -         gimple_call_set_lhs (new_stmt, lhs);

> -       }

> -      *stmt_p = new_stmt;

> -      return true;

>      }

>

> -  /* Otherwise, no need to rebuild the statement, let's just modify arguments

> -     and the LHS if/as appropriate.  */

> -  bool modified = false;

> -  for (unsigned i = 0; i < nargs; i++)

> +  gcall *new_stmt = gimple_build_call_vec (gimple_call_fn (stmt), vargs);

> +  if (gimple_has_location (stmt))

> +    gimple_set_location (new_stmt, gimple_location (stmt));

> +  gimple_call_set_chain (new_stmt, gimple_call_chain (stmt));

> +  gimple_call_copy_flags (new_stmt, stmt);

> +  if (tree lhs = gimple_call_lhs (stmt))

>      {

> -      tree *t = gimple_call_arg_ptr (stmt, i);

> -      modified |= modify_expression (t, true);

> +      modify_expression (&lhs, false);

> +      gimple_call_set_lhs (new_stmt, lhs);

>      }

> +  *stmt_p = new_stmt;

>

> -  if (gimple_call_lhs (stmt))

> -    {

> -      tree *t = gimple_call_lhs_ptr (stmt);

> -      modified |= modify_expression (t, false);

> -    }

> -

> -  return modified;

> +  m_new_call_arg_modification_info = true;

> +  if (orig_stmt)

> +    record_argument_state (m_id, orig_stmt, index_map, pass_through_map,

> +                          always_copy_delta);

> +  return true;

>  }

>

>  /* If the statement STMT contains any expressions that need to replaced with a

> @@ -1720,7 +1904,8 @@ ipa_param_body_adjustments::modify_call_stmt (gcall **stmt_p)

>

>  bool

>  ipa_param_body_adjustments::modify_gimple_stmt (gimple **stmt,

> -                                               gimple_seq *extra_stmts)

> +                                               gimple_seq *extra_stmts,

> +                                               gimple *orig_stmt)

>  {

>    bool modified = false;

>    tree *t;

> @@ -1740,7 +1925,7 @@ ipa_param_body_adjustments::modify_gimple_stmt (gimple **stmt,

>        break;

>

>      case GIMPLE_CALL:

> -      modified |= modify_call_stmt ((gcall **) stmt);

> +      modified |= modify_call_stmt ((gcall **) stmt, orig_stmt);

>        break;

>

>      case GIMPLE_ASM:

> @@ -1797,7 +1982,7 @@ ipa_param_body_adjustments::modify_cfun_body ()

>           gimple *stmt = gsi_stmt (gsi);

>           gimple *stmt_copy = stmt;

>           gimple_seq extra_stmts = NULL;

> -         bool modified = modify_gimple_stmt (&stmt, &extra_stmts);

> +         bool modified = modify_gimple_stmt (&stmt, &extra_stmts, NULL);

>           if (stmt != stmt_copy)

>             {

>               gcc_checking_assert (modified);

> @@ -1945,4 +2130,3 @@ ipa_param_body_adjustments::perform_cfun_body_modifications ()

>

>    return cfg_changed;

>  }

> -

> diff --git a/gcc/ipa-param-manipulation.h b/gcc/ipa-param-manipulation.h

> index c80e1bc5d6b..f59d17717ee 100644

> --- a/gcc/ipa-param-manipulation.h

> +++ b/gcc/ipa-param-manipulation.h

> @@ -54,7 +54,7 @@ or only a vector of ipa_adjusted_params.

>  When these classes are used in the context of call graph clone materialization

>  and subsequent call statement redirection - which is the point at which we

>  modify arguments in call statements - they need to cooperate with each other in

> -order to handle what we refer to as transitive (IPA-SRA) splits.  These are

> +order to handle what we refer to as pass-through (IPA-SRA) splits.  These are

>  situations when a formal parameter of one function is split into several

>  smaller ones and some of them are then passed on in a call to another function

>  because the formal parameter of this callee has also been split.

> @@ -83,7 +83,7 @@ baz ()

>  Both bar and foo would have their parameter split.  Foo would receive one

>  replacement representing s.b.  Function bar would see its parameter split into

>  one replacement representing z.s.a and another representing z.s.b which would

> -be passed on to foo.  It would be a so called transitive split IPA-SRA

> +be passed on to foo.  It would be a so called pass-through split IPA-SRA

>  replacement, one which is passed in a call as an actual argument to another

>  IPA-SRA replacement in another function.

>

> @@ -95,30 +95,25 @@ all of the above.

>

>  Call redirection has to be able to find the right decl or SSA_NAME that

>  corresponds to the transitive split in the caller.  The SSA names are assigned

> -right after clone materialization/ modification and cannot be "added"

> -afterwards.  Moreover, if the caller has been inlined the SSA_NAMEs in question

> -no longer belong to PARM_DECLs but to VAR_DECLs, indistinguishable from any

> -others.

> +right after clone materialization/ modification and cannot be "added" to call

> +arguments at any later point.  Moreover, if the caller has been inlined the

> +SSA_NAMEs in question no longer belong to PARM_DECLs but to VAR_DECLs,

> +indistinguishable from any others.

>

>  Therefore, when clone materialization finds a call statement which it knows is

> -a part of a transitive split, it will modify it into:

> +a part of a transitive split, it will simply add as arguments all new "split"

> +replacements (that have grater or equal offset than the original call

> +argument):

>

> -  foo (DUMMY_Z_VAR.s, repl_for_a, repl_for_b, <rest of original arguments>);

> +  foo (repl_for_a, repl_for_b, <rest of original arguments>);

>

> -It will also store {DUMMY_S_VAR, 32} and {DUMMY_S_VAR, 64} representing offsets

> -of z.s.a and z.s.b (assuming a 32-bit int) into foo's cgraph node

> -clone->performed_splits vector (which is storing structures of type

> -ipa_param_performed_split also defined in this header file).

> -

> -Call redirection will identify that expression DUMMY_Z_VAR.s is based on a

> -variable stored in performed_splits vector and learn that the following

> -arguments, already in SSA form, represent offsets 32 and 64 in a split original

> -parameter.  It subtracts offset of DUMMY_Z_VAR.s from 32 and 64 and arrives at

> -offsets 0 and 32 within callee's original parameter.  At this point it also

> -knows from the call graph that only the bit with offset 32 is needed and so

> -changes the call statement into final:

> -

> -bar (repl_for_b, <rest of original arguments>);  */

> +It will also store into ipa_edge_modification_info (which is internal to

> +ipa-param-modification.c) information about which replacement is which and

> +where original arguments are.  Call redirection will then invoke

> +ipa_param_adjustments::modify_call which will access this information and

> +eliminate all replacements which the callee does not expect (repl_for_a in our

> +example above).  In between these two steps, however, a call statement might

> +have extraneous arguments.  */

>

>  #ifndef IPA_PARAM_MANIPULATION_H

>  #define IPA_PARAM_MANIPULATION_H

> @@ -207,21 +202,6 @@ struct GTY(()) ipa_adjusted_param

>  void ipa_dump_adjusted_parameters (FILE *f,

>                                    vec<ipa_adjusted_param, va_gc> *adj_params);

>

> -/* Structure to remember the split performed on a node so that edge redirection

> -   (i.e. splitting arguments of call statements) know how split formal

> -   parameters of the caller are represented.  */

> -

> -struct GTY(()) ipa_param_performed_split

> -{

> -  /* The dummy VAR_DECL that was created instead of the split parameter that

> -     sits in the call in the meantime between clone materialization and call

> -     redirection.  All entries in a vector of performed splits that correspond

> -     to the same dumy decl must be grouped together.  */

> -  tree dummy_decl;

> -  /* Offset into the original parameter.  */

> -  unsigned unit_offset;

> -};

> -

>  /* Class used to record planned modifications to parameters of a function and

>     also to perform necessary modifications at the caller side at the gimple

>     level.  Used to describe all cgraph node clones that have their parameters

> @@ -244,9 +224,7 @@ public:

>

>    /* Modify a call statement arguments (and possibly remove the return value)

>       as described in the data fields of this class.  */

> -  gcall *modify_call (gcall *stmt,

> -                     vec<ipa_param_performed_split, va_gc> *performed_splits,

> -                     tree callee_decl, bool update_references);

> +  gcall *modify_call (cgraph_edge *cs, bool update_references);

>    /* Return if the first parameter is left intact.  */

>    bool first_param_intact_p ();

>    /* Build a function type corresponding to the modified call.  */

> @@ -293,15 +271,9 @@ struct ipa_param_body_replacement

>    tree base;

>    /* The new decl it should be replaced with.  */

>    tree repl;

> -  /* When modifying clones during IPA clone materialization, this is a dummy

> -     decl used to mark calls in which we need to apply transitive splitting,

> -     these dummy delcls are inserted as arguments to such calls and then

> -     followed by all the replacements with offset info stored in

> -     ipa_param_performed_split.

> -

> -     Users of ipa_param_body_adjustments that modify standalone functions

> -     outside of IPA clone materialization can use this field for their internal

> -     purposes.  */

> +  /* Users of ipa_param_body_adjustments that modify standalone functions

> +     outside of IPA clone materialization can use the following field for their

> +     internal purposes.  */

>    tree dummy;

>    /* The offset within BASE that REPL represents.  */

>    unsigned unit_offset;

> @@ -342,8 +314,7 @@ public:

>    /* Change the PARM_DECLs.  */

>    void modify_formal_parameters ();

>    /* Register a replacement decl for the transformation done in APM.  */

> -  void register_replacement (ipa_adjusted_param *apm, tree replacement,

> -                            tree dummy = NULL_TREE);

> +  void register_replacement (ipa_adjusted_param *apm, tree replacement);

>    /* Lookup a replacement for a given offset within a given parameter.  */

>    tree lookup_replacement (tree base, unsigned unit_offset);

>    /* Lookup a replacement for an expression, if there is one.  */

> @@ -353,7 +324,8 @@ public:

>       parameter. */

>    tree get_replacement_ssa_base (tree old_decl);

>    /* Modify a statement.  */

> -  bool modify_gimple_stmt (gimple **stmt, gimple_seq *extra_stmts);

> +  bool modify_gimple_stmt (gimple **stmt, gimple_seq *extra_stmts,

> +                          gimple *orig_stmt);

>    /* Return the new chain of parameters.  */

>    tree get_new_param_chain ();

>

> @@ -370,6 +342,12 @@ public:

>    /* Set to true if there are any IPA_PARAM_OP_SPLIT adjustments among stored

>       adjustments.  */

>    bool m_split_modifications_p;

> +

> +  /* Sets of statements and SSA_NAMEs that only manipulate data from parameters

> +     removed because they are not necessary.  */

> +  hash_set<gimple *> m_dead_stmts;

> +  hash_set<tree> m_dead_ssas;

> +

>  private:

>    void common_initialization (tree old_fndecl, tree *vars,

>                               vec<ipa_replace_map *, va_gc> *tree_map);

> @@ -380,9 +358,10 @@ private:

>    tree replace_removed_params_ssa_names (tree old_name, gimple *stmt);

>    bool modify_expression (tree *expr_p, bool convert);

>    bool modify_assignment (gimple *stmt, gimple_seq *extra_stmts);

> -  bool modify_call_stmt (gcall **stmt_p);

> +  bool modify_call_stmt (gcall **stmt_p, gimple *orig_stmt);

>    bool modify_cfun_body ();

>    void reset_debug_stmts ();

> +  void mark_dead_statements (tree dead_param);

>

>    /* Declaration of the function that is being transformed.  */

>

> @@ -427,9 +406,16 @@ private:

>       its this pointer and must be converted to a normal function.  */

>

>    bool m_method2func;

> +

> +  /* Set to true if any new information has been stored to

> +     ipa_edge_modifications as part of this body transformation.  */

> +

> +  bool m_new_call_arg_modification_info;

>  };

>

>  void push_function_arg_decls (vec<tree> *args, tree fndecl);

>  void push_function_arg_types (vec<tree> *types, tree fntype);

> +void ipa_verify_edge_has_no_modifications (cgraph_edge *cs);

> +

>

>  #endif /* IPA_PARAM_MANIPULATION_H */

> diff --git a/gcc/symtab-clones.h b/gcc/symtab-clones.h

> index 5695a434f6a..a6ad4a6e27f 100644

> --- a/gcc/symtab-clones.h

> +++ b/gcc/symtab-clones.h

> @@ -26,8 +26,7 @@ struct GTY(()) clone_info

>    /* Constructor.  */

>    clone_info ()

>      : tree_map (NULL),

> -      param_adjustments (NULL),

> -      performed_splits (NULL)

> +      param_adjustments (NULL)

>    {

>    }

>    /* Constants discovered by IPA-CP, i.e. which parameter should be replaced

> @@ -35,18 +34,6 @@ struct GTY(()) clone_info

>    vec<ipa_replace_map *, va_gc> *tree_map;

>    /* Parameter modification that IPA-SRA decided to perform.  */

>    ipa_param_adjustments *param_adjustments;

> -  /* Lists of dummy-decl and offset pairs representing split formal parameters

> -     in the caller.  Offsets of all new replacements are enumerated, those

> -     coming from the same original parameter have the same dummy decl stored

> -     along with them.

> -

> -     Dummy decls sit in call statement arguments followed by new parameter

> -     decls (or their SSA names) in between (caller) clone materialization and

> -     call redirection.  Redirection then recognizes the dummy variable and

> -     together with the stored offsets can reconstruct what exactly the new

> -     parameter decls represent and can leave in place only those that the

> -     callee expects.  */

> -  vec<ipa_param_performed_split, va_gc> *performed_splits;

>

>    /* Return clone_info, if available.  */

>    static clone_info *get (cgraph_node *node);

> diff --git a/gcc/testsuite/g++.dg/ipa/ipa-sra-4.C b/gcc/testsuite/g++.dg/ipa/ipa-sra-4.C

> new file mode 100644

> index 00000000000..56d59f9fd9a

> --- /dev/null

> +++ b/gcc/testsuite/g++.dg/ipa/ipa-sra-4.C

> @@ -0,0 +1,37 @@

> +/* { dg-do compile { target c++11 } } */

> +/* { dg-options "-O2 -fipa-sra"  } */

> +

> +void __throw_bad_alloc() __attribute__((__noreturn__));

> +void __throw_bad_array_new_length();

> +template <typename> class allocator {};

> +template <typename> struct allocator_traits;

> +int *allocate___trans_tmp_2;

> +template <typename _Tp> struct allocator_traits<allocator<_Tp>> {

> +  using allocator_type = allocator<_Tp>;

> +  using pointer = _Tp *;

> +  using size_type = long;

> +  static pointer allocate(allocator_type &, size_type __n) {

> +    long __trans_tmp_3 = __n;

> +    if (__builtin_expect(__trans_tmp_3, false))

> +      if (__trans_tmp_3)

> +        __throw_bad_array_new_length();

> +    operator new(sizeof(int));

> +    return allocate___trans_tmp_2;

> +  }

> +};

> +class throw_allocator_base {

> +  allocator<int> _M_allocator;

> +public:

> +  int *allocate(long __n) {

> +    if (__n)

> +      __throw_bad_alloc();

> +    int *a = allocator_traits<allocator<int>>::allocate(_M_allocator, __n);

> +    return a;

> +  }

> +};

> +template <typename Alloc> void check_allocate_max_size() {

> +  Alloc a;

> +  long __trans_tmp_1 = 0;

> +  a.allocate(__trans_tmp_1 + 1);

> +}

> +int main() { check_allocate_max_size<throw_allocator_base>(); }

> diff --git a/gcc/testsuite/gcc.dg/ipa/ipa-sra-23.c b/gcc/testsuite/gcc.dg/ipa/ipa-sra-23.c

> new file mode 100644

> index 00000000000..f438b509614

> --- /dev/null

> +++ b/gcc/testsuite/gcc.dg/ipa/ipa-sra-23.c

> @@ -0,0 +1,24 @@

> +/* { dg-do compile } */

> +/* { dg-options "-O2"  } */

> +

> +extern int g;

> +

> +static int __attribute__((noinline))

> +bar (int i, int j)

> +{

> +  return 2*g + i;

> +}

> +

> +static int __attribute__((noinline))

> +foo (int i, int j)

> +{

> +  if (i > 5)

> +    j = 22;

> +  return bar (i, j) + 1;

> +}

> +

> +int

> +entry (int l, int k)

> +{

> +  return foo (l, k);

> +}

> diff --git a/gcc/testsuite/gcc.dg/ipa/ipa-sra-24.c b/gcc/testsuite/gcc.dg/ipa/ipa-sra-24.c

> new file mode 100644

> index 00000000000..7b5bf0825fc

> --- /dev/null

> +++ b/gcc/testsuite/gcc.dg/ipa/ipa-sra-24.c

> @@ -0,0 +1,20 @@

> +/* { dg-do compile } */

> +/* { dg-options "-O2 -Wmaybe-uninitialized -Werror"  } */

> +

> +int *ttmp_1;

> +_Bool pt_ins_tipdo, pq_ins_apd, pq_ins_tt2;

> +int gtrphdt;

> +

> +void pl_ins(int, _Bool, _Bool);

> +inline void pt_ins(int *, _Bool apdo) {

> +  int list = *ttmp_1;

> +  pl_ins(list, apdo, pt_ins_tipdo);

> +}

> +void pq_ins(int *t) {

> +  if (pq_ins_tt2)

> +    pt_ins(t, pq_ins_apd);

> +}

> +int gtr_post_hd() {

> +  pq_ins(&gtrphdt);

> +  return 0;

> +}

> diff --git a/gcc/testsuite/gcc.dg/ipa/pr93385.c b/gcc/testsuite/gcc.dg/ipa/pr93385.c

> new file mode 100644

> index 00000000000..6d1d0d7cd27

> --- /dev/null

> +++ b/gcc/testsuite/gcc.dg/ipa/pr93385.c

> @@ -0,0 +1,27 @@

> +/* { dg-do run } */

> +/* { dg-options "-O2 -fno-dce -fno-ipa-cp -fno-tree-dce" } */

> +

> +char a, b;

> +

> +#ifdef __SIZEOF_INT128__

> +#define T unsigned __int128

> +#else

> +#define T unsigned

> +#endif

> +

> +static inline int

> +c (T d)

> +{

> +  char e = 0;

> +  d %= (unsigned) d;

> +  e -= 0;

> +  __builtin_strncpy (&a, &e, 1);

> +  return e + b;

> +}

> +

> +int

> +main (void)

> +{

> +  c (~0);

> +  return 0;

> +}

> diff --git a/gcc/tree-inline.c b/gcc/tree-inline.c

> index 1dcb31c0267..165c4ad7c72 100644

> --- a/gcc/tree-inline.c

> +++ b/gcc/tree-inline.c

> @@ -1528,6 +1528,11 @@ remap_gimple_stmt (gimple *stmt, copy_body_data *id)

>           : !opt_for_fn (id->dst_fn, flag_var_tracking_assignments)))

>      return NULL;

>

> +  if (!is_gimple_debug (stmt)

> +      && id->param_body_adjs

> +      && id->param_body_adjs->m_dead_stmts.contains (stmt))

> +    return NULL;

> +

>    /* Begin by recognizing trees that we'll completely rewrite for the

>       inlining context.  Our output for these trees is completely

>       different from our input (e.g. RETURN_EXPR is deleted and morphs

> @@ -1792,10 +1797,15 @@ remap_gimple_stmt (gimple *stmt, copy_body_data *id)

>

>        if (gimple_debug_bind_p (stmt))

>         {

> +         tree value;

> +         if (id->param_body_adjs

> +             && id->param_body_adjs->m_dead_stmts.contains (stmt))

> +           value = NULL_TREE;

> +         else

> +           value = gimple_debug_bind_get_value (stmt);

>           gdebug *copy

>             = gimple_build_debug_bind (gimple_debug_bind_get_var (stmt),

> -                                      gimple_debug_bind_get_value (stmt),

> -                                      stmt);

> +                                      value, stmt);

>           if (id->reset_location)

>             gimple_set_location (copy, input_location);

>           id->debug_stmts.safe_push (copy);

> @@ -1924,7 +1934,7 @@ remap_gimple_stmt (gimple *stmt, copy_body_data *id)

>    if (id->param_body_adjs)

>      {

>        gimple_seq extra_stmts = NULL;

> -      id->param_body_adjs->modify_gimple_stmt (&copy, &extra_stmts);

> +      id->param_body_adjs->modify_gimple_stmt (&copy, &extra_stmts, stmt);

>        if (!gimple_seq_empty_p (extra_stmts))

>         {

>           memset (&wi, 0, sizeof (wi));

> @@ -2674,7 +2684,9 @@ copy_phis_for_bb (basic_block bb, copy_body_data *id)

>        phi = si.phi ();

>        res = PHI_RESULT (phi);

>        new_res = res;

> -      if (!virtual_operand_p (res))

> +      if (!virtual_operand_p (res)

> +         && (!id->param_body_adjs

> +             || !id->param_body_adjs->m_dead_stmts.contains (phi)))

>         {

>           walk_tree (&new_res, copy_tree_body_r, id, NULL);

>           if (EDGE_COUNT (new_bb->preds) == 0)

> @@ -4740,7 +4752,6 @@ expand_call_inline (basic_block bb, gimple *stmt, copy_body_data *id,

>    use_operand_p use;

>    gimple *simtenter_stmt = NULL;

>    vec<tree> *simtvars_save;

> -  clone_info *info;

>

>    /* The gimplifier uses input_location in too many places, such as

>       internal_get_tmp_var ().  */

> @@ -5065,40 +5076,6 @@ expand_call_inline (basic_block bb, gimple *stmt, copy_body_data *id,

>    /* Add local vars in this inlined callee to caller.  */

>    add_local_variables (id->src_cfun, cfun, id);

>

> -  info = clone_info::get (id->src_node);

> -  if (info && info->performed_splits)

> -    {

> -      clone_info *dst_info = clone_info::get_create (id->dst_node);

> -      /* Any calls from the inlined function will be turned into calls from the

> -        function we inline into.  We must preserve notes about how to split

> -        parameters such calls should be redirected/updated.  */

> -      unsigned len = vec_safe_length (info->performed_splits);

> -      for (unsigned i = 0; i < len; i++)

> -       {

> -         ipa_param_performed_split ps

> -           = (*info->performed_splits)[i];

> -         ps.dummy_decl = remap_decl (ps.dummy_decl, id);

> -         vec_safe_push (dst_info->performed_splits, ps);

> -       }

> -

> -      if (flag_checking)

> -       {

> -         len = vec_safe_length (dst_info->performed_splits);

> -         for (unsigned i = 0; i < len; i++)

> -           {

> -             ipa_param_performed_split *ps1

> -               = &(*dst_info->performed_splits)[i];

> -             for (unsigned j = i + 1; j < len; j++)

> -               {

> -                 ipa_param_performed_split *ps2

> -                   = &(*dst_info->performed_splits)[j];

> -                 gcc_assert (ps1->dummy_decl != ps2->dummy_decl

> -                             || ps1->unit_offset != ps2->unit_offset);

> -               }

> -           }

> -       }

> -    }

> -

>    if (dump_enabled_p ())

>      {

>        char buf[128];

> @@ -6117,23 +6094,10 @@ tree_versionable_function_p (tree fndecl)

>  static void

>  update_clone_info (copy_body_data * id)

>  {

> -  clone_info *dst_info = clone_info::get (id->dst_node);

> -  vec<ipa_param_performed_split, va_gc> *cur_performed_splits

> -    = dst_info ? dst_info->performed_splits : NULL;

> -  if (cur_performed_splits)

> -    {

> -      unsigned len = cur_performed_splits->length ();

> -      for (unsigned i = 0; i < len; i++)

> -       {

> -         ipa_param_performed_split *ps = &(*cur_performed_splits)[i];

> -         ps->dummy_decl = remap_decl (ps->dummy_decl, id);

> -       }

> -    }

> -

> -  struct cgraph_node *node;

> -  if (!id->dst_node->clones)

> +  struct cgraph_node *this_node = id->dst_node;

> +  if (!this_node->clones)

>      return;

> -  for (node = id->dst_node->clones; node != id->dst_node;)

> +  for (cgraph_node *node = this_node->clones; node != this_node;)

>      {

>        /* First update replace maps to match the new body.  */

>        clone_info *info = clone_info::get (node);

> @@ -6147,53 +6111,6 @@ update_clone_info (copy_body_data * id)

>               walk_tree (&replace_info->new_tree, copy_tree_body_r, id, NULL);

>             }

>         }

> -      if (info && info->performed_splits)

> -       {

> -         unsigned len = vec_safe_length (info->performed_splits);

> -         for (unsigned i = 0; i < len; i++)

> -           {

> -             ipa_param_performed_split *ps

> -               = &(*info->performed_splits)[i];

> -             ps->dummy_decl = remap_decl (ps->dummy_decl, id);

> -           }

> -       }

> -      if (unsigned len = vec_safe_length (cur_performed_splits))

> -       {

> -         /* We do not want to add current performed splits when we are saving

> -            a copy of function body for later during inlining, that would just

> -            duplicate all entries.  So let's have a look whether anything

> -            referring to the first dummy_decl is present.  */

> -         if (!info)

> -           info = clone_info::get_create (node);

> -         unsigned dst_len = vec_safe_length (info->performed_splits);

> -         ipa_param_performed_split *first = &(*cur_performed_splits)[0];

> -         for (unsigned i = 0; i < dst_len; i++)

> -           if ((*info->performed_splits)[i].dummy_decl

> -               == first->dummy_decl)

> -             {

> -               len = 0;

> -               break;

> -             }

> -

> -         for (unsigned i = 0; i < len; i++)

> -           vec_safe_push (info->performed_splits,

> -                          (*cur_performed_splits)[i]);

> -         if (flag_checking)

> -           {

> -             for (unsigned i = 0; i < dst_len; i++)

> -               {

> -                 ipa_param_performed_split *ps1

> -                   = &(*info->performed_splits)[i];

> -                 for (unsigned j = i + 1; j < dst_len; j++)

> -                   {

> -                     ipa_param_performed_split *ps2

> -                       = &(*info->performed_splits)[j];

> -                     gcc_assert (ps1->dummy_decl != ps2->dummy_decl

> -                                 || ps1->unit_offset != ps2->unit_offset);

> -                   }

> -               }

> -           }

> -       }

>

>        if (node->clones)

>         node = node->clones;

> --

> 2.31.1

>
Martin Jambor May 10, 2021, 6:48 p.m. | #2
Hi,

On Mon, May 10 2021, Richard Biener wrote:
> I've tried to have a look at this patch but it does a lot of IPA specific

> refactoring(?), so the actual DCE bits are hard to find.  Is it possible

> to split the patch up or is it too entangled?

>


Yes:

I was asked by Richi to split my fix for PR 93385 for easier review
into IPA-SRA materialization refactoring and the actual DCE addition.
Fortunately it was mostly natural except for a temporary weird
condition in ipa_param_body_adjustments::modify_call_stmt.

This is the first part which basically replaces performed_splits in
clone_info and the code which generates it, keeps it up-to-date and
consumes it with new edge summaries which are much nicer.  It simply
contains 1) a mapping from the original argument indices to the actual
indices in the call statement as it is now, 2) information needed to
identify arguments representing pass-through IPA-SRA splits with which
have been added to the call arguments in place of an original
argument/reference and 3) a delta to the index where va_args may start
- so basically directly all the information that the consumer of
performed_splits had to compute and we also do not need the weird
dummy declarations.

The main disadvantage is that the information has to be created (and
kept up-to-date) for all call graph edges associated with the given
statement from all clones (including inline clones) of the clone where
splitting or removal happened first.  But all of this happens during
clone materialization so the only effect on WPA memory consumption is
the removal of a pointer from clone_info.

The statement modification code also has to know the statement from
the original function in order to be able to locate the edge summaries
which at this point are still keyed to these.  However, the code is
already quite heavily dependant on how things are structured in
tree-inline.c and in order to fix bugs like these it probably has to
be.

The subsequent patch needs this new information to be able to remove
arguments from calls during materialization and communicate this
information to the call redirection.

The patch this one is split off introduced a field of
ipa_param_body_adjustments called m_new_call_arg_modification_info which
was not needed for anything, I have removed it.

The patch is so far only lightly tested but I have verified that
together with the second one they make up pretty much exactly the
original one (modulo m_new_call_arg_modification_info) which I did
bootstrap this morning.  I will of course bootstrap it independently
too.

What do you think?

Martin


2021-05-10  Martin Jambor  <mjambor@suse.cz>

	PR ipa/93385
	* symtab-clones.h (clone_info): Removed member param_adjustments.
	* ipa-param-manipulation.h: Adjust initial comment to reflect how we
	deal with pass-through splits now.
	(ipa_param_performed_split): Removed.
	(ipa_param_adjustments::modify_call): Adjusted parameters.
	(class ipa_param_body_adjustments): Adjusted parameters of
	register_replacement, modify_gimple_stmt and modify_call_stmt.
	(ipa_verify_edge_has_no_modifications): Declare.
	* cgraph.c (cgraph_edge::redirect_call_stmt_to_callee): Remove
	performed_splits processing, pas only edge to padjs->modify_call,
	check that call arguments were not modified if they should not have
	been.
	* cgraphclones.c (cgraph_node::create_clone): Do not copy performed
	splits.
	* ipa-param-manipulation.c (struct pass_through_split_map): New type.
	(ipa_edge_modification_info): Likewise.
	(ipa_edge_modification_sum): Likewise.
	(ipa_edge_modifications): New edge summary.
	(ipa_verify_edge_has_no_modifications): New function.
	(transitive_split_p): Removed.
	(transitive_split_map): Likewise.
	(init_transitive_splits): Likewise.
	(ipa_param_adjustments::modify_call): Adjusted to use the new edge
	summary instead of performed_splits.
	(ipa_param_body_adjustments::register_replacement): Drop dummy
	parameter, set base_index of the created ipa_param_body_replacement.
	(phi_arg_will_live_p): New function.
	(ipa_param_body_adjustments::common_initialization): Do not create
	IPA_SRA dummy decls.
	(simple_tree_swap_info): Removed.
	(remap_split_decl_to_dummy): Likewise.
	(record_argument_state_1): New function.
	(record_argument_state): Likewise.
	(ipa_param_body_adjustments::modify_call_stmt): New parameter
	orig_stmt.  Do not work with dummy decls, save necessary info about
	changes to ipa_edge_modifications.
	(ipa_param_body_adjustments::modify_gimple_stmt): New parameter
	orig_stmt, pass it to modify_call_stmt.
	(ipa_param_body_adjustments::modify_cfun_body): Adjust call to
	modify_gimple_stmt.
	* tree-inline.c (remap_gimple_stmt): Pass original statement to
	modify_gimple_stmt.
	(copy_phis_for_bb): Do not copy dead PHI nodes.
	(expand_call_inline): Do not remap performed_splits.
	(update_clone_info): Likewise.
---
 gcc/cgraph.c                 |  22 +-
 gcc/cgraphclones.c           |   3 -
 gcc/ipa-param-manipulation.c | 784 +++++++++++++++++++----------------
 gcc/ipa-param-manipulation.h |  81 ++--
 gcc/symtab-clones.h          |  15 +-
 gcc/tree-inline.c            | 103 +----
 6 files changed, 465 insertions(+), 543 deletions(-)

diff --git a/gcc/cgraph.c b/gcc/cgraph.c
index d7c78d518bc..d473da5a325 100644
--- a/gcc/cgraph.c
+++ b/gcc/cgraph.c
@@ -1506,8 +1506,6 @@ cgraph_edge::redirect_call_stmt_to_callee (cgraph_edge *e)
     }
 
   clone_info *callee_info = clone_info::get (e->callee);
-  clone_info *caller_info = clone_info::get (e->caller);
-
   if (symtab->dump_file)
     {
       fprintf (symtab->dump_file, "updating call of %s -> %s: ",
@@ -1515,18 +1513,6 @@ cgraph_edge::redirect_call_stmt_to_callee (cgraph_edge *e)
       print_gimple_stmt (symtab->dump_file, e->call_stmt, 0, dump_flags);
       if (callee_info && callee_info->param_adjustments)
 	callee_info->param_adjustments->dump (symtab->dump_file);
-      unsigned performed_len
-	= caller_info ? vec_safe_length (caller_info->performed_splits) : 0;
-      if (performed_len > 0)
-	fprintf (symtab->dump_file, "Performed splits records:\n");
-      for (unsigned i = 0; i < performed_len; i++)
-	{
-	  ipa_param_performed_split *sm
-	    = &(*caller_info->performed_splits)[i];
-	  print_node_brief (symtab->dump_file, "  dummy_decl: ", sm->dummy_decl,
-			    TDF_UID);
-	  fprintf (symtab->dump_file, ", unit_offset: %u\n", sm->unit_offset);
-	}
     }
 
   if (ipa_param_adjustments *padjs
@@ -1541,10 +1527,7 @@ cgraph_edge::redirect_call_stmt_to_callee (cgraph_edge *e)
 	remove_stmt_from_eh_lp (e->call_stmt);
 
       tree old_fntype = gimple_call_fntype (e->call_stmt);
-      new_stmt = padjs->modify_call (e->call_stmt,
-				     caller_info
-				     ? caller_info->performed_splits : NULL,
-				     e->callee->decl, false);
+      new_stmt = padjs->modify_call (e, false);
       cgraph_node *origin = e->callee;
       while (origin->clone_of)
 	origin = origin->clone_of;
@@ -1564,6 +1547,9 @@ cgraph_edge::redirect_call_stmt_to_callee (cgraph_edge *e)
     }
   else
     {
+      if (flag_checking
+	  && !fndecl_built_in_p (e->callee->decl, BUILT_IN_UNREACHABLE))
+	ipa_verify_edge_has_no_modifications (e);
       new_stmt = e->call_stmt;
       gimple_call_set_fndecl (new_stmt, e->callee->decl);
       update_stmt_fn (DECL_STRUCT_FUNCTION (e->caller->decl), new_stmt);
diff --git a/gcc/cgraphclones.c b/gcc/cgraphclones.c
index 9f86463b42d..7e463acab91 100644
--- a/gcc/cgraphclones.c
+++ b/gcc/cgraphclones.c
@@ -414,9 +414,6 @@ cgraph_node::create_clone (tree new_decl, profile_count prof_count,
   else if (info && info->param_adjustments)
     clone_info::get_create (new_node)->param_adjustments
 	 = info->param_adjustments;
-  if (info && info->performed_splits)
-    clone_info::get_create (new_node)->performed_splits
-	 = vec_safe_copy (info->performed_splits);
   new_node->split_part = split_part;
 
   FOR_EACH_VEC_ELT (redirect_callers, i, e)
diff --git a/gcc/ipa-param-manipulation.c b/gcc/ipa-param-manipulation.c
index 1d1e64f546a..424b8e5343f 100644
--- a/gcc/ipa-param-manipulation.c
+++ b/gcc/ipa-param-manipulation.c
@@ -62,6 +62,80 @@ static const char *ipa_param_op_names[IPA_PARAM_PREFIX_COUNT]
      "IPA_PARAM_OP_NEW",
      "IPA_PARAM_OP_SPLIT"};
 
+/* Structure to hold declarations representing pass-through IPA-SRA splits.  In
+   essence, it tells new index for a combination of original index and
+   offset.  */
+
+struct pass_through_split_map
+{
+  /* Original argument index.  */
+  unsigned base_index;
+  /* Offset of the split part in the original argument.  */
+  unsigned unit_offset;
+  /* Index of the split part in the call statement - where clone
+     materialization put it.  */
+  int new_index;
+};
+
+/* Information about some call statements that needs to be conveyed from clone
+   materialization to edge redirection. */
+
+class ipa_edge_modification_info
+{
+ public:
+  ipa_edge_modification_info ()
+    {}
+
+  /* Mapping of original argument indices to where those arguments sit in the
+     call statement now or to a negative index if they were removed.  */
+  auto_vec<int> index_map;
+  /* Information about ISRA replacements put into the call statement at the
+     clone materialization stages.  */
+  auto_vec<pass_through_split_map> pass_through_map;
+  /* Necessary adjustment to ipa_param_adjustments::m_always_copy_start when
+     redirecting the call.  */
+  int always_copy_delta = 0;
+};
+
+/* Class for storing and retrieving summaries about cal statement
+   modifications.  */
+
+class ipa_edge_modification_sum
+  : public call_summary <ipa_edge_modification_info *>
+{
+ public:
+  ipa_edge_modification_sum (symbol_table *table)
+    : call_summary<ipa_edge_modification_info *> (table)
+  {
+  }
+
+  /* Hook that is called by summary when an edge is duplicated.  */
+
+  virtual void duplicate (cgraph_edge *,
+			  cgraph_edge *,
+			  ipa_edge_modification_info *old_info,
+			  ipa_edge_modification_info *new_info)
+  {
+    new_info->index_map.safe_splice (old_info->index_map);
+    new_info->pass_through_map.safe_splice (old_info->pass_through_map);
+    new_info->always_copy_delta = old_info->always_copy_delta;
+  }
+};
+
+/* Call summary to store information about edges which have had their arguments
+   partially modified already.  */
+
+static ipa_edge_modification_sum *ipa_edge_modifications;
+
+/* Fail compilation if CS has any summary associated with it in
+   ipa_edge_modifications.  */
+
+DEBUG_FUNCTION void
+ipa_verify_edge_has_no_modifications (cgraph_edge *cs)
+{
+  gcc_assert (!ipa_edge_modifications || !ipa_edge_modifications->get (cs));
+}
+
 /* Fill an empty vector ARGS with PARM_DECLs representing formal parameters of
    FNDECL.  The function should not be called during LTO WPA phase except for
    thunks (or functions with bodies streamed in). */
@@ -459,147 +533,46 @@ isra_get_ref_base_and_offset (tree expr, tree *base_p, unsigned *unit_offset_p)
   return true;
 }
 
-/* Return true if EXPR describes a transitive split (i.e. one that happened for
-   both the caller and the callee) as recorded in PERFORMED_SPLITS.  In that
-   case, store index of the respective record in PERFORMED_SPLITS into
-   *SM_IDX_P and the unit offset from all handled components in EXPR into
-   *UNIT_OFFSET_P.  */
-
-static bool
-transitive_split_p (vec<ipa_param_performed_split, va_gc> *performed_splits,
-		    tree expr, unsigned *sm_idx_p, unsigned *unit_offset_p)
-{
-  tree base;
-  if (!isra_get_ref_base_and_offset (expr, &base, unit_offset_p))
-    return false;
-
-  if (TREE_CODE (base) == SSA_NAME)
-    {
-      base = SSA_NAME_VAR (base);
-      if (!base)
-	return false;
-    }
-
-  unsigned len = vec_safe_length (performed_splits);
-  for (unsigned i = 0 ; i < len; i++)
-    {
-      ipa_param_performed_split *sm = &(*performed_splits)[i];
-      if (sm->dummy_decl == base)
-	{
-	  *sm_idx_p = i;
-	  return true;
-	}
-    }
-  return false;
-}
-
-/* Structure to hold declarations representing transitive IPA-SRA splits.  In
-   essence, if we need to pass UNIT_OFFSET of a parameter which originally has
-   number BASE_INDEX, we should pass down REPL.  */
-
-struct transitive_split_map
-{
-  tree repl;
-  unsigned base_index;
-  unsigned unit_offset;
-};
-
-/* If call STMT contains any parameters representing transitive splits as
-   described by PERFORMED_SPLITS, return the number of extra parameters that
-   were addded during clone materialization and fill in INDEX_MAP with adjusted
-   indices of corresponding original parameters and TRANS_MAP with description
-   of all transitive replacement descriptions.  Otherwise return zero. */
-
-static unsigned
-init_transitive_splits (vec<ipa_param_performed_split, va_gc> *performed_splits,
-			gcall *stmt, vec <unsigned> *index_map,
-			auto_vec <transitive_split_map> *trans_map)
-{
-  unsigned phony_arguments = 0;
-  unsigned stmt_idx = 0, base_index = 0;
-  unsigned nargs = gimple_call_num_args (stmt);
-  while (stmt_idx < nargs)
-    {
-      unsigned unit_offset_delta;
-      tree base_arg = gimple_call_arg (stmt, stmt_idx);
-
-      if (phony_arguments > 0)
-	index_map->safe_push (stmt_idx);
-
-      unsigned sm_idx;
-      stmt_idx++;
-      if (transitive_split_p (performed_splits, base_arg, &sm_idx,
-			      &unit_offset_delta))
-	{
-	  if (phony_arguments == 0)
-	    /* We have optimistically avoided constructing index_map do far but
-	       now it is clear it will be necessary, so let's create the easy
-	       bit we skipped until now.  */
-	    for (unsigned k = 0; k < stmt_idx; k++)
-	      index_map->safe_push (k);
-
-	  tree dummy = (*performed_splits)[sm_idx].dummy_decl;
-	  for (unsigned j = sm_idx; j < performed_splits->length (); j++)
-	    {
-	      ipa_param_performed_split *caller_split
-		= &(*performed_splits)[j];
-	      if (caller_split->dummy_decl != dummy)
-		break;
-
-	      tree arg = gimple_call_arg (stmt, stmt_idx);
-	      struct transitive_split_map tsm;
-	      tsm.repl = arg;
-	      tsm.base_index = base_index;
-	      if (caller_split->unit_offset >= unit_offset_delta)
-		{
-		  tsm.unit_offset
-		    = (caller_split->unit_offset - unit_offset_delta);
-		  trans_map->safe_push (tsm);
-		}
-
-	      phony_arguments++;
-	      stmt_idx++;
-	    }
-	}
-      base_index++;
-    }
-  return phony_arguments;
-}
-
-/* Modify actual arguments of a function call in statement STMT, assuming it
-   calls CALLEE_DECL.  CALLER_ADJ must be the description of parameter
-   adjustments of the caller or NULL if there are none.  Return the new
-   statement that replaced the old one.  When invoked, cfun and
-   current_function_decl have to be set to the caller.  */
+/* Modify actual arguments of a function call in statement currently belonging
+   to CS, and make it call CS->callee->decl.  Return the new statement that
+   replaced the old one.  When invoked, cfun and current_function_decl have to
+   be set to the caller.  */
 
 gcall *
-ipa_param_adjustments::modify_call (gcall *stmt,
-				    vec<ipa_param_performed_split,
-				        va_gc> *performed_splits,
-				    tree callee_decl, bool update_references)
+ipa_param_adjustments::modify_call (cgraph_edge *cs,
+				    bool update_references)
 {
+  gcall *stmt = cs->call_stmt;
+  tree callee_decl = cs->callee->decl;
+
+  ipa_edge_modification_info *mod_info
+    = ipa_edge_modifications ? ipa_edge_modifications->get (cs) : NULL;
+  if (mod_info && symtab->dump_file)
+    {
+      fprintf (symtab->dump_file, "Information about pre-exiting "
+	       "modifications.\n  Index map:");
+      unsigned idx_len = mod_info->index_map.length ();
+      for (unsigned i = 0; i < idx_len; i++)
+	fprintf (symtab->dump_file, " %i", mod_info->index_map[i]);
+      fprintf (symtab->dump_file, "\n  Pass-through split map: ");
+      unsigned ptm_len = mod_info->pass_through_map.length ();
+      for (unsigned i = 0; i < ptm_len; i++)
+	fprintf (symtab->dump_file,
+		 " (base_index: %u, offset: %u, new_index: %i)",
+		 mod_info->pass_through_map[i].base_index,
+		 mod_info->pass_through_map[i].unit_offset,
+		 mod_info->pass_through_map[i].new_index);
+      fprintf (symtab->dump_file, "\n  Always-copy delta: %i\n",
+	       mod_info->always_copy_delta);
+    }
+
   unsigned len = vec_safe_length (m_adj_params);
   auto_vec<tree, 16> vargs (len);
-  tree old_decl = gimple_call_fndecl (stmt);
   unsigned old_nargs = gimple_call_num_args (stmt);
+  unsigned orig_nargs = mod_info ? mod_info->index_map.length () : old_nargs;
   auto_vec<bool, 16> kept (old_nargs);
   kept.quick_grow_cleared (old_nargs);
 
-  auto_vec <unsigned, 16> index_map;
-  auto_vec <transitive_split_map> trans_map;
-  bool transitive_remapping = false;
-
-  if (performed_splits)
-    {
-      unsigned removed = init_transitive_splits (performed_splits,
-						 stmt, &index_map, &trans_map);
-      if (removed > 0)
-	{
-	  transitive_remapping = true;
-	  old_nargs -= removed;
-	}
-    }
-
   cgraph_node *current_node = cgraph_node::get (current_function_decl);
   if (update_references)
     current_node->remove_stmt_references (stmt);
@@ -612,13 +585,16 @@ ipa_param_adjustments::modify_call (gcall *stmt,
       ipa_adjusted_param *apm = &(*m_adj_params)[i];
       if (apm->op == IPA_PARAM_OP_COPY)
 	{
-	  unsigned index = apm->base_index;
-	  if (index >= old_nargs)
+	  int index = apm->base_index;
+	  if ((unsigned) index >= orig_nargs)
 	    /* Can happen if the original call has argument mismatch,
 	       ignore.  */
 	    continue;
-	  if (transitive_remapping)
-	    index = index_map[apm->base_index];
+	  if (mod_info)
+	    {
+	      index = mod_info->index_map[apm->base_index];
+	      gcc_assert (index >= 0);
+	    }
 
 	  tree arg = gimple_call_arg (stmt, index);
 
@@ -636,14 +612,17 @@ ipa_param_adjustments::modify_call (gcall *stmt,
 	 materialization.  */
       gcc_assert (apm->op == IPA_PARAM_OP_SPLIT);
 
-      /* We have to handle transitive changes differently using the maps we
-	 have created before.  So look into them first.  */
+      /* We have to handle pass-through changes differently using the map
+	 clone materialziation might have left behind.  */
       tree repl = NULL_TREE;
-      for (unsigned j = 0; j < trans_map.length (); j++)
-	if (trans_map[j].base_index == apm->base_index
-	    && trans_map[j].unit_offset == apm->unit_offset)
+      unsigned ptm_len = mod_info ? mod_info->pass_through_map.length () : 0;
+      for (unsigned j = 0; j < ptm_len; j++)
+	if (mod_info->pass_through_map[j].base_index == apm->base_index
+	    && mod_info->pass_through_map[j].unit_offset == apm->unit_offset)
 	  {
-	    repl = trans_map[j].repl;
+	    int repl_idx = mod_info->pass_through_map[j].new_index;
+	    gcc_assert (repl_idx >= 0);
+	    repl = gimple_call_arg (stmt, repl_idx);
 	    break;
 	  }
       if (repl)
@@ -652,12 +631,15 @@ ipa_param_adjustments::modify_call (gcall *stmt,
 	  continue;
 	}
 
-      unsigned index = apm->base_index;
-      if (index >= old_nargs)
+      int index = apm->base_index;
+      if ((unsigned) index >= orig_nargs)
 	/* Can happen if the original call has argument mismatch, ignore.  */
 	continue;
-      if (transitive_remapping)
-	index = index_map[apm->base_index];
+      if (mod_info)
+	{
+	  index = mod_info->index_map[apm->base_index];
+	  gcc_assert (index >= 0);
+	}
       tree base = gimple_call_arg (stmt, index);
 
       /* We create a new parameter out of the value of the old one, we can
@@ -773,8 +755,16 @@ ipa_param_adjustments::modify_call (gcall *stmt,
     }
 
   if (m_always_copy_start >= 0)
-    for (unsigned i = m_always_copy_start; i < old_nargs; i++)
-      vargs.safe_push (gimple_call_arg (stmt, i));
+    {
+      int always_copy_start = m_always_copy_start;
+      if (mod_info)
+	{
+	  always_copy_start += mod_info->always_copy_delta;
+	  gcc_assert (always_copy_start >= 0);
+	}
+      for (unsigned i = always_copy_start; i < old_nargs; i++)
+	vargs.safe_push (gimple_call_arg (stmt, i));
+    }
 
   /* For optimized away parameters, add on the caller side
      before the call
@@ -782,6 +772,7 @@ ipa_param_adjustments::modify_call (gcall *stmt,
      stmts and associate D#X with parm in decl_debug_args_lookup
      vector to say for debug info that if parameter parm had been passed,
      it would have value parm_Y(D).  */
+  tree old_decl = gimple_call_fndecl (stmt);
   if (MAY_HAVE_DEBUG_BIND_STMTS && old_decl && callee_decl)
     {
       vec<tree, va_gc> **debug_args = NULL;
@@ -799,13 +790,17 @@ ipa_param_adjustments::modify_call (gcall *stmt,
 	{
 	  if (!is_gimple_reg (old_parm) || kept[i])
 	    continue;
-	  tree origin = DECL_ORIGIN (old_parm);
 	  tree arg;
-	  if (transitive_remapping)
-	    arg = gimple_call_arg (stmt, index_map[i]);
+	  if (mod_info)
+	    {
+	      if (mod_info->index_map[i] < 0)
+		continue;
+	      arg = gimple_call_arg (stmt, mod_info->index_map[i]);
+	    }
 	  else
 	    arg = gimple_call_arg (stmt, i);
 
+	  tree origin = DECL_ORIGIN (old_parm);
 	  if (!useless_type_conversion_p (TREE_TYPE (origin), TREE_TYPE (arg)))
 	    {
 	      if (!fold_convertible_p (TREE_TYPE (origin), arg))
@@ -909,6 +904,9 @@ ipa_param_adjustments::modify_call (gcall *stmt,
 	gsi_prev (&gsi);
       }
     while (gsi_stmt (gsi) != gsi_stmt (prev_gsi));
+
+  if (mod_info)
+    ipa_edge_modifications->remove (cs);
   return new_stmt;
 }
 
@@ -931,13 +929,11 @@ ipa_param_adjustments::debug ()
   dump (stderr);
 }
 
-/* Register that REPLACEMENT should replace parameter described in APM and
-   optionally as DUMMY to mark transitive splits across calls.  */
+/* Register that REPLACEMENT should replace parameter described in APM.  */
 
 void
 ipa_param_body_adjustments::register_replacement (ipa_adjusted_param *apm,
-						  tree replacement,
-						  tree dummy)
+						  tree replacement)
 {
   gcc_checking_assert (apm->op == IPA_PARAM_OP_SPLIT
 		       || apm->op == IPA_PARAM_OP_NEW);
@@ -945,7 +941,6 @@ ipa_param_body_adjustments::register_replacement (ipa_adjusted_param *apm,
   ipa_param_body_replacement psr;
   psr.base = m_oparms[apm->prev_clone_index];
   psr.repl = replacement;
-  psr.dummy = dummy;
   psr.unit_offset = apm->unit_offset;
   m_replacements.safe_push (psr);
 }
@@ -1007,9 +1002,6 @@ ipa_param_body_adjustments::common_initialization (tree old_fndecl,
   auto_vec<bool, 16> kept;
   kept.reserve_exact (m_oparms.length ());
   kept.quick_grow_cleared (m_oparms.length ());
-  auto_vec<tree, 16> isra_dummy_decls;
-  isra_dummy_decls.reserve_exact (m_oparms.length ());
-  isra_dummy_decls.quick_grow_cleared (m_oparms.length ());
 
   unsigned adj_len = vec_safe_length (m_adj_params);
   m_method2func = ((TREE_CODE (TREE_TYPE (m_fndecl)) == METHOD_TYPE)
@@ -1055,35 +1047,7 @@ ipa_param_body_adjustments::common_initialization (tree old_fndecl,
 	  if (apm->op == IPA_PARAM_OP_SPLIT)
 	    {
 	      m_split_modifications_p = true;
-
-	      if (m_id)
-		{
-		  tree dummy_decl;
-		  if (!isra_dummy_decls[prev_index])
-		    {
-		      dummy_decl = copy_decl_to_var (m_oparms[prev_index],
-						     m_id);
-		      /* Any attempt to remap this dummy in this particular
-			 instance of clone materialization should yield
-			 itself.  */
-		      insert_decl_map (m_id, dummy_decl, dummy_decl);
-
-		      DECL_CHAIN (dummy_decl) = *vars;
-		      *vars = dummy_decl;
-		      isra_dummy_decls[prev_index] = dummy_decl;
-		    }
-		  else
-		    dummy_decl = isra_dummy_decls[prev_index];
-
-		  register_replacement (apm, new_parm, dummy_decl);
-		  ipa_param_performed_split ps;
-		  ps.dummy_decl = dummy_decl;
-		  ps.unit_offset = apm->unit_offset;
-		  vec_safe_push (clone_info::get_create
-				   (m_id->dst_node)->performed_splits, ps);
-		}
-	      else
-		register_replacement (apm, new_parm);
+	      register_replacement (apm, new_parm);
 	    }
         }
       else
@@ -1110,8 +1074,6 @@ ipa_param_body_adjustments::common_initialization (tree old_fndecl,
 	  {
 	    if (!m_id->decl_map->get (m_oparms[i]))
 	      {
-		/* TODO: Perhaps at least aggregate-type params could re-use
-		   their isra_dummy_decl here?  */
 		tree var = copy_decl_to_var (m_oparms[i], m_id);
 		insert_decl_map (m_id, m_oparms[i], var);
 		/* Declare this new variable.  */
@@ -1502,218 +1464,327 @@ ipa_param_body_adjustments::modify_assignment (gimple *stmt,
   return any;
 }
 
-/* Data passed to remap_split_decl_to_dummy through walk_tree.  */
+/* Record information about what modifications to call arguments have already
+   been done by clone materialization into a summary describing CS.  The
+   information is stored in NEW_INDEX_MAP, NEW_PT_MAP and NEW_ALWAYS_COPY_DELTA
+   and correspond to equivalent fields in ipa_edge_modification_info.  Return
+   the edge summary.  */
+
+static ipa_edge_modification_info *
+record_argument_state_1 (cgraph_edge *cs, const vec<int> &new_index_map,
+			 const vec<pass_through_split_map> &new_pt_map,
+			 int new_always_copy_delta)
 
-struct simple_tree_swap_info
 {
-  /* Change FROM to TO.  */
-  tree from, to;
-  /* And set DONE to true when doing so.  */
-  bool done;
-};
+  ipa_edge_modification_info *sum = ipa_edge_modifications->get_create (cs);
 
-/* Simple remapper to remap a split parameter to the same expression based on a
-   special dummy decl so that edge redirections can detect transitive splitting
-   and finish them.  */
-
-static tree
-remap_split_decl_to_dummy (tree *tp, int *walk_subtrees, void *data)
-{
-  tree t = *tp;
-
-  if (DECL_P (t) || TREE_CODE (t) == SSA_NAME)
+  unsigned len = sum->pass_through_map.length ();
+  for (unsigned i = 0; i < len; i++)
     {
-      struct simple_tree_swap_info *swapinfo
-	= (struct simple_tree_swap_info *) data;
-      if (t == swapinfo->from
-	  || (TREE_CODE (t) == SSA_NAME
-	      && SSA_NAME_VAR (t) == swapinfo->from))
-	{
-	  *tp = swapinfo->to;
-	  swapinfo->done = true;
-	}
-      *walk_subtrees = 0;
+      unsigned oldnew = sum->pass_through_map[i].new_index;
+      sum->pass_through_map[i].new_index = new_index_map[oldnew];
+    }
+
+  len = sum->index_map.length ();
+  if (len > 0)
+    {
+      unsigned nptlen = new_pt_map.length ();
+      for (unsigned j = 0; j < nptlen; j++)
+	{
+	  int inverse = -1;
+	  for (unsigned i = 0; i < len ; i++)
+	    if ((unsigned) sum->index_map[i] == new_pt_map[j].base_index)
+	    {
+	      inverse = i;
+	      break;
+	    }
+	  gcc_assert (inverse >= 0);
+	  pass_through_split_map ptm_item;
+
+	  ptm_item.base_index = inverse;
+	  ptm_item.unit_offset = new_pt_map[j].unit_offset;
+	  ptm_item.new_index = new_pt_map[j].new_index;
+	  sum->pass_through_map.safe_push (ptm_item);
+	}
+
+      for (unsigned i = 0; i < len; i++)
+	{
+	  int idx = sum->index_map[i];
+	  if (idx < 0)
+	    continue;
+	  sum->index_map[i] = new_index_map[idx];
+	}
     }
-  else if (TYPE_P (t))
-      *walk_subtrees = 0;
   else
-    *walk_subtrees = 1;
-  return NULL_TREE;
+    {
+      sum->pass_through_map.safe_splice (new_pt_map);
+      sum->index_map.safe_splice (new_index_map);
+    }
+  sum->always_copy_delta += new_always_copy_delta;
+  return sum;
 }
 
+/* Record information about what modifications to call arguments have already
+   been done by clone materialization into a summary of an edge describing the
+   call in this clone and all its clones.  NEW_INDEX_MAP, NEW_PT_MAP and
+   NEW_ALWAYS_COPY_DELTA have the same meaning as record_argument_state_1.
+
+   In order to associate the info with the right edge summaries, we need
+   address of the ORIG_STMT in the function from which we are cloning (because
+   the edges have not yet been re-assigned to the new statement that has just
+   been created) and ID, the structure governing function body copying.  */
+
+static void
+record_argument_state (copy_body_data *id, gimple *orig_stmt,
+		       const vec<int> &new_index_map,
+		       const vec<pass_through_split_map> &new_pt_map,
+		       int new_always_copy_delta)
+{
+  if (!ipa_edge_modifications)
+    ipa_edge_modifications = new ipa_edge_modification_sum (symtab);
+
+  struct cgraph_node *this_node = id->dst_node;
+  ipa_edge_modification_info *first_sum = NULL;
+  cgraph_edge *cs = this_node->get_edge (orig_stmt);
+  if (cs)
+    first_sum = record_argument_state_1 (cs, new_index_map, new_pt_map,
+					 new_always_copy_delta);
+  else
+    gcc_assert (this_node->clones);
+
+  if (!this_node->clones)
+    return;
+  for (cgraph_node *subclone = this_node->clones; subclone != this_node;)
+    {
+      cs = subclone->get_edge (orig_stmt);
+      if (cs)
+	{
+	  if (!first_sum)
+	    first_sum = record_argument_state_1 (cs, new_index_map, new_pt_map,
+						 new_always_copy_delta);
+	  else
+	    {
+	      ipa_edge_modification_info *s2
+		= ipa_edge_modifications->get_create (cs);
+	      s2->index_map.truncate (0);
+	      s2->index_map.safe_splice (first_sum->index_map);
+	      s2->pass_through_map.truncate (0);
+	      s2->pass_through_map.safe_splice (first_sum->pass_through_map);
+	      s2->always_copy_delta = first_sum->always_copy_delta;
+	    }
+	}
+      else
+	gcc_assert (subclone->clones);
+
+      if (subclone->clones)
+	subclone = subclone->clones;
+      else if (subclone->next_sibling_clone)
+	subclone = subclone->next_sibling_clone;
+      else
+	{
+	  while (subclone != this_node && !subclone->next_sibling_clone)
+	    subclone = subclone->clone_of;
+	  if (subclone != this_node)
+	    subclone = subclone->next_sibling_clone;
+	}
+    }
+}
 
 /* If the call statement pointed at by STMT_P contains any expressions that
    need to replaced with a different one as noted by ADJUSTMENTS, do so.  f the
    statement needs to be rebuilt, do so.  Return true if any modifications have
-   been performed.
+   been performed.  ORIG_STMT, if not NULL, is the original statement in the
+   function that is being cloned from, which at this point can be used to look
+   up call_graph edges.
 
    If the method is invoked as a part of IPA clone materialization and if any
-   parameter split is transitive, i.e. it applies to the functin that is being
-   modified and also to the callee of the statement, replace the parameter
-   passed to old callee with an equivalent expression based on a dummy decl
-   followed by PARM_DECLs representing the actual replacements.  The actual
-   replacements will be then converted into SSA_NAMEs and then
-   ipa_param_adjustments::modify_call will find the appropriate ones and leave
-   only those in the call.  */
+   parameter split is pass-through, i.e. it applies to the functin that is
+   being modified and also to the callee of the statement, replace the
+   parameter passed to old callee with all of the replacement a callee might
+   possibly want and record the performed argument modifications in
+   ipa_edge_modifications.  Likewise if any argument has already been left out
+   because it is not necessary.  */
 
 bool
-ipa_param_body_adjustments::modify_call_stmt (gcall **stmt_p)
+ipa_param_body_adjustments::modify_call_stmt (gcall **stmt_p,
+					      gimple *orig_stmt)
 {
-  gcall *stmt = *stmt_p;
   auto_vec <unsigned, 4> pass_through_args;
   auto_vec <unsigned, 4> pass_through_pbr_indices;
+  auto_vec <HOST_WIDE_INT, 4> pass_through_offsets;
+  gcall *stmt = *stmt_p;
+  unsigned nargs = gimple_call_num_args (stmt);
+  bool recreate = false;
 
-  if (m_split_modifications_p && m_id)
+  for (unsigned i = 0; i < gimple_call_num_args (stmt); i++)
     {
-      for (unsigned i = 0; i < gimple_call_num_args (stmt); i++)
+      tree t = gimple_call_arg (stmt, i);
+      gcc_assert (TREE_CODE (t) != BIT_FIELD_REF
+		  && TREE_CODE (t) != IMAGPART_EXPR
+		  && TREE_CODE (t) != REALPART_EXPR);
+
+      /* The follow-up patch will check whether t needs to be removed, that's
+	 why this condition is in the loop.  */
+
+      if (!m_split_modifications_p)
+	continue;
+
+      tree base;
+      unsigned agg_arg_offset;
+      if (!isra_get_ref_base_and_offset (t, &base, &agg_arg_offset))
+	continue;
+
+      bool by_ref = false;
+      if (TREE_CODE (base) == SSA_NAME)
 	{
-	  tree t = gimple_call_arg (stmt, i);
-	  gcc_assert (TREE_CODE (t) != BIT_FIELD_REF
-		      && TREE_CODE (t) != IMAGPART_EXPR
-		      && TREE_CODE (t) != REALPART_EXPR);
-
-	  tree base;
-	  unsigned unit_offset;
-	  if (!isra_get_ref_base_and_offset (t, &base, &unit_offset))
+	  if (!SSA_NAME_IS_DEFAULT_DEF (base))
 	    continue;
+	  base = SSA_NAME_VAR (base);
+	  gcc_checking_assert (base);
+	  by_ref = true;
+	}
+      if (TREE_CODE (base) != PARM_DECL)
+	continue;
 
-	  bool by_ref = false;
-	  if (TREE_CODE (base) == SSA_NAME)
+      bool base_among_replacements = false;
+      unsigned j, repl_list_len = m_replacements.length ();
+      for (j = 0; j < repl_list_len; j++)
+	{
+	  ipa_param_body_replacement *pbr = &m_replacements[j];
+	  if (pbr->base == base)
 	    {
-	      if (!SSA_NAME_IS_DEFAULT_DEF (base))
-		continue;
-	      base = SSA_NAME_VAR (base);
-	      gcc_checking_assert (base);
-	      by_ref = true;
+	      base_among_replacements = true;
+	      break;
 	    }
-	  if (TREE_CODE (base) != PARM_DECL)
-	    continue;
+	}
+      if (!base_among_replacements)
+	continue;
 
-	  bool base_among_replacements = false;
-	  unsigned j, repl_list_len = m_replacements.length ();
-	  for (j = 0; j < repl_list_len; j++)
+      /* We still have to distinguish between an end-use that we have to
+	 transform now and a pass-through, which happens in the following
+	 two cases.  */
+
+      /* TODO: After we adjust ptr_parm_has_nonarg_uses to also consider
+	 &MEM_REF[ssa_name + offset], we will also have to detect that case
+	 here.    */
+
+      if (TREE_CODE (t) == SSA_NAME
+	  && SSA_NAME_IS_DEFAULT_DEF (t)
+	  && SSA_NAME_VAR (t)
+	  && TREE_CODE (SSA_NAME_VAR (t)) == PARM_DECL)
+	{
+	  /* This must be a by_reference pass-through.  */
+	  recreate = true;
+	  gcc_assert (POINTER_TYPE_P (TREE_TYPE (t)));
+	  pass_through_args.safe_push (i);
+	  pass_through_pbr_indices.safe_push (j);
+	  pass_through_offsets.safe_push (agg_arg_offset);
+	}
+      else if (!by_ref && AGGREGATE_TYPE_P (TREE_TYPE (t)))
+	{
+	  /* Currently IPA-SRA guarantees the aggregate access type
+	     exactly matches in this case.  So if it does not match, it is
+	     a pass-through argument that will be sorted out at edge
+	     redirection time.  */
+	  ipa_param_body_replacement *pbr
+	    = lookup_replacement_1 (base, agg_arg_offset);
+
+	  if (!pbr
+	      || (TYPE_MAIN_VARIANT (TREE_TYPE (t))
+		  != TYPE_MAIN_VARIANT (TREE_TYPE (pbr->repl))))
 	    {
-	      ipa_param_body_replacement *pbr = &m_replacements[j];
-	      if (pbr->base == base)
-		{
-		  base_among_replacements = true;
-		  break;
-		}
-	    }
-	  if (!base_among_replacements)
-	    continue;
-
-	  /* We still have to distinguish between an end-use that we have to
-	     transform now and a pass-through, which happens in the following
-	     two cases.  */
-
-	  /* TODO: After we adjust ptr_parm_has_nonarg_uses to also consider
-	     &MEM_REF[ssa_name + offset], we will also have to detect that case
-	     here.    */
-
-	  if (TREE_CODE (t) == SSA_NAME
-	      && SSA_NAME_IS_DEFAULT_DEF (t)
-	      && SSA_NAME_VAR (t)
-	      && TREE_CODE (SSA_NAME_VAR (t)) == PARM_DECL)
-	    {
-	      /* This must be a by_reference pass-through.  */
-	      gcc_assert (POINTER_TYPE_P (TREE_TYPE (t)));
+	      recreate = true;
 	      pass_through_args.safe_push (i);
 	      pass_through_pbr_indices.safe_push (j);
-	    }
-	  else if (!by_ref && AGGREGATE_TYPE_P (TREE_TYPE (t)))
-	    {
-	      /* Currently IPA-SRA guarantees the aggregate access type
-		 exactly matches in this case.  So if it does not match, it is
-		 a pass-through argument that will be sorted out at edge
-		 redirection time.  */
-	      ipa_param_body_replacement *pbr
-		= lookup_replacement_1 (base, unit_offset);
-
-	      if (!pbr
-		  || (TYPE_MAIN_VARIANT (TREE_TYPE (t))
-		      != TYPE_MAIN_VARIANT (TREE_TYPE (pbr->repl))))
-		{
-		  pass_through_args.safe_push (i);
-		  pass_through_pbr_indices.safe_push (j);
-		}
+	      pass_through_offsets.safe_push (agg_arg_offset);
 	    }
 	}
     }
 
-  unsigned nargs = gimple_call_num_args (stmt);
-  if (!pass_through_args.is_empty ())
+  if (!recreate)
     {
-      auto_vec<tree, 16> vargs;
-      unsigned pt_idx = 0;
+      /* No need to rebuild the statement, let's just modify arguments
+	 and the LHS if/as appropriate.  */
+      bool modified = false;
       for (unsigned i = 0; i < nargs; i++)
 	{
-	  if (pt_idx < pass_through_args.length ()
-	      && i == pass_through_args[pt_idx])
-	    {
-	      unsigned j = pass_through_pbr_indices[pt_idx];
-	      pt_idx++;
-	      tree base = m_replacements[j].base;
-
-	      /* Map base will get mapped to the special transitive-isra marker
-		 dummy decl. */
-	      struct simple_tree_swap_info swapinfo;
-	      swapinfo.from = base;
-	      swapinfo.to = m_replacements[j].dummy;
-	      swapinfo.done = false;
-	      tree arg = gimple_call_arg (stmt, i);
-	      walk_tree (&arg, remap_split_decl_to_dummy, &swapinfo, NULL);
-	      gcc_assert (swapinfo.done);
-	      vargs.safe_push (arg);
-	      /* Now let's push all replacements pertaining to this parameter
-		 so that all gimple register ones get correct SSA_NAMES.  Edge
-		 redirection will weed out the dummy argument as well as all
-		 unused replacements later.  */
-	      unsigned int repl_list_len = m_replacements.length ();
-	      for (; j < repl_list_len; j++)
-		{
-		  if (m_replacements[j].base != base)
-		    break;
-		  vargs.safe_push (m_replacements[j].repl);
-		}
-	    }
-	  else
-	    {
-	      tree t = gimple_call_arg (stmt, i);
-	      modify_expression (&t, true);
-	      vargs.safe_push (t);
-	    }
+	  tree *t = gimple_call_arg_ptr (stmt, i);
+	  modified |= modify_expression (t, true);
 	}
-      gcall *new_stmt = gimple_build_call_vec (gimple_call_fn (stmt), vargs);
-      if (gimple_has_location (stmt))
-	gimple_set_location (new_stmt, gimple_location (stmt));
-      gimple_call_set_chain (new_stmt, gimple_call_chain (stmt));
-      gimple_call_copy_flags (new_stmt, stmt);
-      if (tree lhs = gimple_call_lhs (stmt))
+      if (gimple_call_lhs (stmt))
 	{
-	  modify_expression (&lhs, false);
-	  gimple_call_set_lhs (new_stmt, lhs);
+	  tree *t = gimple_call_lhs_ptr (stmt);
+	  modified |= modify_expression (t, false);
 	}
-      *stmt_p = new_stmt;
-      return true;
+      return modified;
     }
 
-  /* Otherwise, no need to rebuild the statement, let's just modify arguments
-     and the LHS if/as appropriate.  */
-  bool modified = false;
+  auto_vec<int, 16> index_map;
+  auto_vec<pass_through_split_map, 4> pass_through_map;
+  auto_vec<tree, 16> vargs;
+  int always_copy_delta = 0;
+  unsigned pt_idx = 0;
+  int new_arg_idx = 0;
   for (unsigned i = 0; i < nargs; i++)
     {
-      tree *t = gimple_call_arg_ptr (stmt, i);
-      modified |= modify_expression (t, true);
+      if (pt_idx < pass_through_args.length ()
+	  && i == pass_through_args[pt_idx])
+	{
+	  unsigned j = pass_through_pbr_indices[pt_idx];
+	  unsigned agg_arg_offset = pass_through_offsets[pt_idx];
+	  pt_idx++;
+	  always_copy_delta--;
+	  tree base = m_replacements[j].base;
+
+	  /* In order to be put into SSA form, we have to push all replacements
+	     pertaining to this parameter as parameters to the call statement.
+	     Edge redirection will need to use edge summary to weed out the
+	     unnecessary ones.  */
+	  unsigned repl_list_len = m_replacements.length ();
+	  for (; j < repl_list_len; j++)
+	    {
+	      if (m_replacements[j].base != base)
+		break;
+	      if (m_replacements[j].unit_offset < agg_arg_offset)
+		continue;
+	      pass_through_split_map pt_map;
+	      pt_map.base_index = i;
+	      pt_map.unit_offset
+		= m_replacements[j].unit_offset - agg_arg_offset;
+	      pt_map.new_index = new_arg_idx;
+	      pass_through_map.safe_push (pt_map);
+	      vargs.safe_push (m_replacements[j].repl);
+	      new_arg_idx++;
+	      always_copy_delta++;
+	    }
+	  index_map.safe_push (-1);
+	}
+      else
+	{
+	  tree t = gimple_call_arg (stmt, i);
+	  modify_expression (&t, true);
+	  vargs.safe_push (t);
+	  index_map.safe_push (new_arg_idx);
+	  new_arg_idx++;
+	}
     }
 
-  if (gimple_call_lhs (stmt))
+  gcall *new_stmt = gimple_build_call_vec (gimple_call_fn (stmt), vargs);
+  if (gimple_has_location (stmt))
+    gimple_set_location (new_stmt, gimple_location (stmt));
+  gimple_call_set_chain (new_stmt, gimple_call_chain (stmt));
+  gimple_call_copy_flags (new_stmt, stmt);
+  if (tree lhs = gimple_call_lhs (stmt))
     {
-      tree *t = gimple_call_lhs_ptr (stmt);
-      modified |= modify_expression (t, false);
+      modify_expression (&lhs, false);
+      gimple_call_set_lhs (new_stmt, lhs);
     }
+  *stmt_p = new_stmt;
 
-  return modified;
+  if (orig_stmt)
+    record_argument_state (m_id, orig_stmt, index_map, pass_through_map,
+			   always_copy_delta);
+  return true;
 }
 
 /* If the statement STMT contains any expressions that need to replaced with a
@@ -1724,7 +1795,8 @@ ipa_param_body_adjustments::modify_call_stmt (gcall **stmt_p)
 
 bool
 ipa_param_body_adjustments::modify_gimple_stmt (gimple **stmt,
-						gimple_seq *extra_stmts)
+						gimple_seq *extra_stmts,
+						gimple *orig_stmt)
 {
   bool modified = false;
   tree *t;
@@ -1744,7 +1816,7 @@ ipa_param_body_adjustments::modify_gimple_stmt (gimple **stmt,
       break;
 
     case GIMPLE_CALL:
-      modified |= modify_call_stmt ((gcall **) stmt);
+      modified |= modify_call_stmt ((gcall **) stmt, orig_stmt);
       break;
 
     case GIMPLE_ASM:
@@ -1801,7 +1873,7 @@ ipa_param_body_adjustments::modify_cfun_body ()
 	  gimple *stmt = gsi_stmt (gsi);
 	  gimple *stmt_copy = stmt;
 	  gimple_seq extra_stmts = NULL;
-	  bool modified = modify_gimple_stmt (&stmt, &extra_stmts);
+	  bool modified = modify_gimple_stmt (&stmt, &extra_stmts, NULL);
 	  if (stmt != stmt_copy)
 	    {
 	      gcc_checking_assert (modified);
diff --git a/gcc/ipa-param-manipulation.h b/gcc/ipa-param-manipulation.h
index c80e1bc5d6b..fd0df7b299c 100644
--- a/gcc/ipa-param-manipulation.h
+++ b/gcc/ipa-param-manipulation.h
@@ -54,7 +54,7 @@ or only a vector of ipa_adjusted_params.
 When these classes are used in the context of call graph clone materialization
 and subsequent call statement redirection - which is the point at which we
 modify arguments in call statements - they need to cooperate with each other in
-order to handle what we refer to as transitive (IPA-SRA) splits.  These are
+order to handle what we refer to as pass-through (IPA-SRA) splits.  These are
 situations when a formal parameter of one function is split into several
 smaller ones and some of them are then passed on in a call to another function
 because the formal parameter of this callee has also been split.
@@ -83,7 +83,7 @@ baz ()
 Both bar and foo would have their parameter split.  Foo would receive one
 replacement representing s.b.  Function bar would see its parameter split into
 one replacement representing z.s.a and another representing z.s.b which would
-be passed on to foo.  It would be a so called transitive split IPA-SRA
+be passed on to foo.  It would be a so called pass-through split IPA-SRA
 replacement, one which is passed in a call as an actual argument to another
 IPA-SRA replacement in another function.
 
@@ -95,30 +95,25 @@ all of the above.
 
 Call redirection has to be able to find the right decl or SSA_NAME that
 corresponds to the transitive split in the caller.  The SSA names are assigned
-right after clone materialization/ modification and cannot be "added"
-afterwards.  Moreover, if the caller has been inlined the SSA_NAMEs in question
-no longer belong to PARM_DECLs but to VAR_DECLs, indistinguishable from any
-others.
+right after clone materialization/ modification and cannot be "added" to call
+arguments at any later point.  Moreover, if the caller has been inlined the
+SSA_NAMEs in question no longer belong to PARM_DECLs but to VAR_DECLs,
+indistinguishable from any others.
 
 Therefore, when clone materialization finds a call statement which it knows is
-a part of a transitive split, it will modify it into:
+a part of a transitive split, it will simply add as arguments all new "split"
+replacements (that have grater or equal offset than the original call
+argument):
 
-  foo (DUMMY_Z_VAR.s, repl_for_a, repl_for_b, <rest of original arguments>);
+  foo (repl_for_a, repl_for_b, <rest of original arguments>);
 
-It will also store {DUMMY_S_VAR, 32} and {DUMMY_S_VAR, 64} representing offsets
-of z.s.a and z.s.b (assuming a 32-bit int) into foo's cgraph node
-clone->performed_splits vector (which is storing structures of type
-ipa_param_performed_split also defined in this header file).
-
-Call redirection will identify that expression DUMMY_Z_VAR.s is based on a
-variable stored in performed_splits vector and learn that the following
-arguments, already in SSA form, represent offsets 32 and 64 in a split original
-parameter.  It subtracts offset of DUMMY_Z_VAR.s from 32 and 64 and arrives at
-offsets 0 and 32 within callee's original parameter.  At this point it also
-knows from the call graph that only the bit with offset 32 is needed and so
-changes the call statement into final:
-
-bar (repl_for_b, <rest of original arguments>);  */
+It will also store into ipa_edge_modification_info (which is internal to
+ipa-param-modification.c) information about which replacement is which and
+where original arguments are.  Call redirection will then invoke
+ipa_param_adjustments::modify_call which will access this information and
+eliminate all replacements which the callee does not expect (repl_for_a in our
+example above).  In between these two steps, however, a call statement might
+have extraneous arguments.  */
 
 #ifndef IPA_PARAM_MANIPULATION_H
 #define IPA_PARAM_MANIPULATION_H
@@ -207,21 +202,6 @@ struct GTY(()) ipa_adjusted_param
 void ipa_dump_adjusted_parameters (FILE *f,
 				   vec<ipa_adjusted_param, va_gc> *adj_params);
 
-/* Structure to remember the split performed on a node so that edge redirection
-   (i.e. splitting arguments of call statements) know how split formal
-   parameters of the caller are represented.  */
-
-struct GTY(()) ipa_param_performed_split
-{
-  /* The dummy VAR_DECL that was created instead of the split parameter that
-     sits in the call in the meantime between clone materialization and call
-     redirection.  All entries in a vector of performed splits that correspond
-     to the same dumy decl must be grouped together.  */
-  tree dummy_decl;
-  /* Offset into the original parameter.  */
-  unsigned unit_offset;
-};
-
 /* Class used to record planned modifications to parameters of a function and
    also to perform necessary modifications at the caller side at the gimple
    level.  Used to describe all cgraph node clones that have their parameters
@@ -244,9 +224,7 @@ public:
 
   /* Modify a call statement arguments (and possibly remove the return value)
      as described in the data fields of this class.  */
-  gcall *modify_call (gcall *stmt,
-		      vec<ipa_param_performed_split, va_gc> *performed_splits,
-		      tree callee_decl, bool update_references);
+  gcall *modify_call (cgraph_edge *cs, bool update_references);
   /* Return if the first parameter is left intact.  */
   bool first_param_intact_p ();
   /* Build a function type corresponding to the modified call.  */
@@ -293,15 +271,9 @@ struct ipa_param_body_replacement
   tree base;
   /* The new decl it should be replaced with.  */
   tree repl;
-  /* When modifying clones during IPA clone materialization, this is a dummy
-     decl used to mark calls in which we need to apply transitive splitting,
-     these dummy delcls are inserted as arguments to such calls and then
-     followed by all the replacements with offset info stored in
-     ipa_param_performed_split.
-
-     Users of ipa_param_body_adjustments that modify standalone functions
-     outside of IPA clone materialization can use this field for their internal
-     purposes.  */
+  /* Users of ipa_param_body_adjustments that modify standalone functions
+     outside of IPA clone materialization can use the following field for their
+     internal purposes.  */
   tree dummy;
   /* The offset within BASE that REPL represents.  */
   unsigned unit_offset;
@@ -342,8 +314,7 @@ public:
   /* Change the PARM_DECLs.  */
   void modify_formal_parameters ();
   /* Register a replacement decl for the transformation done in APM.  */
-  void register_replacement (ipa_adjusted_param *apm, tree replacement,
-			     tree dummy = NULL_TREE);
+  void register_replacement (ipa_adjusted_param *apm, tree replacement);
   /* Lookup a replacement for a given offset within a given parameter.  */
   tree lookup_replacement (tree base, unsigned unit_offset);
   /* Lookup a replacement for an expression, if there is one.  */
@@ -353,7 +324,8 @@ public:
      parameter. */
   tree get_replacement_ssa_base (tree old_decl);
   /* Modify a statement.  */
-  bool modify_gimple_stmt (gimple **stmt, gimple_seq *extra_stmts);
+  bool modify_gimple_stmt (gimple **stmt, gimple_seq *extra_stmts,
+			   gimple *orig_stmt);
   /* Return the new chain of parameters.  */
   tree get_new_param_chain ();
 
@@ -380,9 +352,10 @@ private:
   tree replace_removed_params_ssa_names (tree old_name, gimple *stmt);
   bool modify_expression (tree *expr_p, bool convert);
   bool modify_assignment (gimple *stmt, gimple_seq *extra_stmts);
-  bool modify_call_stmt (gcall **stmt_p);
+  bool modify_call_stmt (gcall **stmt_p, gimple *orig_stmt);
   bool modify_cfun_body ();
   void reset_debug_stmts ();
+  void mark_dead_statements (tree dead_param);
 
   /* Declaration of the function that is being transformed.  */
 
@@ -431,5 +404,7 @@ private:
 
 void push_function_arg_decls (vec<tree> *args, tree fndecl);
 void push_function_arg_types (vec<tree> *types, tree fntype);
+void ipa_verify_edge_has_no_modifications (cgraph_edge *cs);
+
 
 #endif	/* IPA_PARAM_MANIPULATION_H */
diff --git a/gcc/symtab-clones.h b/gcc/symtab-clones.h
index 5695a434f6a..a6ad4a6e27f 100644
--- a/gcc/symtab-clones.h
+++ b/gcc/symtab-clones.h
@@ -26,8 +26,7 @@ struct GTY(()) clone_info
   /* Constructor.  */
   clone_info ()
     : tree_map (NULL),
-      param_adjustments (NULL),
-      performed_splits (NULL)
+      param_adjustments (NULL)
   {
   }
   /* Constants discovered by IPA-CP, i.e. which parameter should be replaced
@@ -35,18 +34,6 @@ struct GTY(()) clone_info
   vec<ipa_replace_map *, va_gc> *tree_map;
   /* Parameter modification that IPA-SRA decided to perform.  */
   ipa_param_adjustments *param_adjustments;
-  /* Lists of dummy-decl and offset pairs representing split formal parameters
-     in the caller.  Offsets of all new replacements are enumerated, those
-     coming from the same original parameter have the same dummy decl stored
-     along with them.
-
-     Dummy decls sit in call statement arguments followed by new parameter
-     decls (or their SSA names) in between (caller) clone materialization and
-     call redirection.  Redirection then recognizes the dummy variable and
-     together with the stored offsets can reconstruct what exactly the new
-     parameter decls represent and can leave in place only those that the
-     callee expects.  */
-  vec<ipa_param_performed_split, va_gc> *performed_splits;
 
   /* Return clone_info, if available.  */
   static clone_info *get (cgraph_node *node);
diff --git a/gcc/tree-inline.c b/gcc/tree-inline.c
index 8f945b88c12..e2fb6be681c 100644
--- a/gcc/tree-inline.c
+++ b/gcc/tree-inline.c
@@ -1900,7 +1900,7 @@ remap_gimple_stmt (gimple *stmt, copy_body_data *id)
   if (id->param_body_adjs)
     {
       gimple_seq extra_stmts = NULL;
-      id->param_body_adjs->modify_gimple_stmt (&copy, &extra_stmts);
+      id->param_body_adjs->modify_gimple_stmt (&copy, &extra_stmts, stmt);
       if (!gimple_seq_empty_p (extra_stmts))
 	{
 	  memset (&wi, 0, sizeof (wi));
@@ -4721,7 +4721,6 @@ expand_call_inline (basic_block bb, gimple *stmt, copy_body_data *id,
   use_operand_p use;
   gimple *simtenter_stmt = NULL;
   vec<tree> *simtvars_save;
-  clone_info *info;
 
   /* The gimplifier uses input_location in too many places, such as
      internal_get_tmp_var ().  */
@@ -5046,40 +5045,6 @@ expand_call_inline (basic_block bb, gimple *stmt, copy_body_data *id,
   /* Add local vars in this inlined callee to caller.  */
   add_local_variables (id->src_cfun, cfun, id);
 
-  info = clone_info::get (id->src_node);
-  if (info && info->performed_splits)
-    {
-      clone_info *dst_info = clone_info::get_create (id->dst_node);
-      /* Any calls from the inlined function will be turned into calls from the
-	 function we inline into.  We must preserve notes about how to split
-	 parameters such calls should be redirected/updated.  */
-      unsigned len = vec_safe_length (info->performed_splits);
-      for (unsigned i = 0; i < len; i++)
-	{
-	  ipa_param_performed_split ps
-	    = (*info->performed_splits)[i];
-	  ps.dummy_decl = remap_decl (ps.dummy_decl, id);
-	  vec_safe_push (dst_info->performed_splits, ps);
-	}
-
-      if (flag_checking)
-	{
-	  len = vec_safe_length (dst_info->performed_splits);
-	  for (unsigned i = 0; i < len; i++)
-	    {
-	      ipa_param_performed_split *ps1
-		= &(*dst_info->performed_splits)[i];
-	      for (unsigned j = i + 1; j < len; j++)
-		{
-		  ipa_param_performed_split *ps2
-		    = &(*dst_info->performed_splits)[j];
-		  gcc_assert (ps1->dummy_decl != ps2->dummy_decl
-			      || ps1->unit_offset != ps2->unit_offset);
-		}
-	    }
-	}
-    }
-
   if (dump_enabled_p ())
     {
       char buf[128];
@@ -6103,23 +6068,10 @@ tree_versionable_function_p (tree fndecl)
 static void
 update_clone_info (copy_body_data * id)
 {
-  clone_info *dst_info = clone_info::get (id->dst_node);
-  vec<ipa_param_performed_split, va_gc> *cur_performed_splits
-    = dst_info ? dst_info->performed_splits : NULL;
-  if (cur_performed_splits)
-    {
-      unsigned len = cur_performed_splits->length ();
-      for (unsigned i = 0; i < len; i++)
-	{
-	  ipa_param_performed_split *ps = &(*cur_performed_splits)[i];
-	  ps->dummy_decl = remap_decl (ps->dummy_decl, id);
-	}
-    }
-
-  struct cgraph_node *node;
-  if (!id->dst_node->clones)
+  struct cgraph_node *this_node = id->dst_node;
+  if (!this_node->clones)
     return;
-  for (node = id->dst_node->clones; node != id->dst_node;)
+  for (cgraph_node *node = this_node->clones; node != this_node;)
     {
       /* First update replace maps to match the new body.  */
       clone_info *info = clone_info::get (node);
@@ -6133,53 +6085,6 @@ update_clone_info (copy_body_data * id)
 	      walk_tree (&replace_info->new_tree, copy_tree_body_r, id, NULL);
 	    }
 	}
-      if (info && info->performed_splits)
-	{
-	  unsigned len = vec_safe_length (info->performed_splits);
-	  for (unsigned i = 0; i < len; i++)
-	    {
-	      ipa_param_performed_split *ps
-		= &(*info->performed_splits)[i];
-	      ps->dummy_decl = remap_decl (ps->dummy_decl, id);
-	    }
-	}
-      if (unsigned len = vec_safe_length (cur_performed_splits))
-	{
-	  /* We do not want to add current performed splits when we are saving
-	     a copy of function body for later during inlining, that would just
-	     duplicate all entries.  So let's have a look whether anything
-	     referring to the first dummy_decl is present.  */
-	  if (!info)
-	    info = clone_info::get_create (node);
-	  unsigned dst_len = vec_safe_length (info->performed_splits);
-	  ipa_param_performed_split *first = &(*cur_performed_splits)[0];
-	  for (unsigned i = 0; i < dst_len; i++)
-	    if ((*info->performed_splits)[i].dummy_decl
-		== first->dummy_decl)
-	      {
-		len = 0;
-		break;
-	      }
-
-	  for (unsigned i = 0; i < len; i++)
-	    vec_safe_push (info->performed_splits,
-			   (*cur_performed_splits)[i]);
-	  if (flag_checking)
-	    {
-	      for (unsigned i = 0; i < dst_len; i++)
-		{
-		  ipa_param_performed_split *ps1
-		    = &(*info->performed_splits)[i];
-		  for (unsigned j = i + 1; j < dst_len; j++)
-		    {
-		      ipa_param_performed_split *ps2
-			= &(*info->performed_splits)[j];
-		      gcc_assert (ps1->dummy_decl != ps2->dummy_decl
-				  || ps1->unit_offset != ps2->unit_offset);
-		    }
-		}
-	    }
-	}
 
       if (node->clones)
 	node = node->clones;
-- 
2.31.1
Martin Jambor May 10, 2021, 6:52 p.m. | #3
Hi,

On Mon, May 10 2021, Richard Biener wrote:
> I've tried to have a look at this patch but it does a lot of IPA specific

> refactoring(?), so the actual DCE bits are hard to find.  Is it possible

> to split the patch up or is it too entangled?

>


Yes:

I was asked by Richi to split my fix for PR 93385 for easier review
into IPA-SRA materialization refactoring and the actual DCE addition.
This is the second part that actually contains the DCE of statements
that IPA-SRA should not leave behind because they can have problematic
side effects, even if they are useless, so that we do not depend on
tree-dce to remove them for correctness.

The patch fixes the problem by doing a def-use walk when materializing
clones, marking which statements should not be copied and which
SSA_NAMEs do not need to be computed because eventually they would be
DCEd.  We do this on the original function body and tree-inline simply
does not copy statements which are "dead."

The only complication is removing dead argument calls because that
needs to be communicated to callee redirection code using the
infrastructure introduced by the previous patch.

I added all testcases of the original patch to this one, although some
probably test behavior introduced in the previous patch.

The patch is so far only lightly tested but I have verified that
together with the second one they make up pretty much exactly the
original one (modulo m_new_call_arg_modification_info) which I did
bootstrap this morning.  I will of course bootstrap it independently
too.

What do you think?

Martin


gcc/ChangeLog:

2021-05-10  Martin Jambor  <mjambor@suse.cz>

	PR ipa/93385
	* ipa-param-manipulation.h (class ipa_param_body_adjustments): New
	members m_dead_stmts and m_dead_ssas.
	* ipa-param-manipulation.c (phi_arg_will_live_p): New function.
	(ipa_param_body_adjustments::mark_dead_statements): Likwise.
	(ipa_param_body_adjustments::common_initialization): Call it on
	all removed but not split parameters.
	(ipa_param_body_adjustments::ipa_param_body_adjustments): Initialize
	new mwmbers.
	(ipa_param_body_adjustments::modify_call_stmt): Remove arguments that
	are dead.
	* tree-inline.c (remap_gimple_stmt): Do not copy dead statements, reset
	dead debug statements.
	(copy_phis_for_bb): Do not copy dead PHI nodes.

gcc/testsuite/ChangeLog:

2021-03-22  Martin Jambor  <mjambor@suse.cz>

	PR ipa/93385
	* gcc.dg/ipa/pr93385.c: New test.
	* gcc.dg/ipa/ipa-sra-23.c: Likewise.
	* gcc.dg/ipa/ipa-sra-24.c: Likewise.
	* g++.dg/ipa/ipa-sra-4.C: Likewise.
---
 gcc/ipa-param-manipulation.c          | 142 +++++++++++++++++++++++---
 gcc/ipa-param-manipulation.h          |   6 ++
 gcc/testsuite/g++.dg/ipa/ipa-sra-4.C  |  37 +++++++
 gcc/testsuite/gcc.dg/ipa/ipa-sra-23.c |  24 +++++
 gcc/testsuite/gcc.dg/ipa/ipa-sra-24.c |  20 ++++
 gcc/testsuite/gcc.dg/ipa/pr93385.c    |  27 +++++
 gcc/tree-inline.c                     |  18 +++-
 7 files changed, 256 insertions(+), 18 deletions(-)
 create mode 100644 gcc/testsuite/g++.dg/ipa/ipa-sra-4.C
 create mode 100644 gcc/testsuite/gcc.dg/ipa/ipa-sra-23.c
 create mode 100644 gcc/testsuite/gcc.dg/ipa/ipa-sra-24.c
 create mode 100644 gcc/testsuite/gcc.dg/ipa/pr93385.c

diff --git a/gcc/ipa-param-manipulation.c b/gcc/ipa-param-manipulation.c
index 424b8e5343f..d7d73542856 100644
--- a/gcc/ipa-param-manipulation.c
+++ b/gcc/ipa-param-manipulation.c
@@ -969,6 +969,97 @@ ipa_param_body_adjustments::carry_over_param (tree t)
   return new_parm;
 }
 
+/* Return true if BLOCKS_TO_COPY is NULL or if PHI has an argument ARG in
+   position that corresponds to an edge that is coming from a block that has
+   the corresponding bit set in BLOCKS_TO_COPY.  */
+
+static bool
+phi_arg_will_live_p (gphi *phi, bitmap blocks_to_copy, tree arg)
+{
+  bool arg_will_survive = false;
+  if (!blocks_to_copy)
+    arg_will_survive = true;
+  else
+    for (unsigned i = 0; i < gimple_phi_num_args (phi); i++)
+      if (gimple_phi_arg_def (phi, i) == arg
+	  && bitmap_bit_p (blocks_to_copy,
+			   gimple_phi_arg_edge (phi, i)->src->index))
+	{
+	  arg_will_survive = true;
+	  break;
+	}
+  return arg_will_survive;
+}
+
+/* Populate m_dead_stmts given that DEAD_PARAM is going to be removed without
+   any replacement or splitting.  REPL is the replacement VAR_SECL to base any
+   remaining uses of a removed parameter on.  */
+
+void
+ipa_param_body_adjustments::mark_dead_statements (tree dead_param)
+{
+  /* Current IPA analyses which remove unused parameters never remove a
+     non-gimple register ones which have any use except as parameters in other
+     calls, so we can safely leve them as they are.  */
+  if (!is_gimple_reg (dead_param))
+    return;
+  tree parm_ddef = ssa_default_def (m_id->src_cfun, dead_param);
+  if (!parm_ddef || has_zero_uses (parm_ddef))
+    return;
+
+  auto_vec<tree, 4> stack;
+  m_dead_ssas.add (parm_ddef);
+  stack.safe_push (parm_ddef);
+  while (!stack.is_empty ())
+    {
+      tree t = stack.pop ();
+
+      imm_use_iterator imm_iter;
+      gimple *stmt;
+
+      insert_decl_map (m_id, t, error_mark_node);
+      FOR_EACH_IMM_USE_STMT (stmt, imm_iter, t)
+	{
+	  if (is_gimple_call (stmt)
+	      || (m_id->blocks_to_copy
+		  && !bitmap_bit_p (m_id->blocks_to_copy,
+				    gimple_bb (stmt)->index)))
+	    continue;
+
+	  if (is_gimple_debug (stmt))
+	    {
+	      m_dead_stmts.add (stmt);
+	      gcc_assert (gimple_debug_bind_p (stmt));
+	    }
+	  else if (gimple_code (stmt) == GIMPLE_PHI)
+	    {
+	      gphi *phi = as_a <gphi *> (stmt);
+	      if (phi_arg_will_live_p (phi, m_id->blocks_to_copy, t))
+		{
+		  m_dead_stmts.add (phi);
+		  tree res = gimple_phi_result (phi);
+		  if (!m_dead_ssas.add (res))
+		    stack.safe_push (res);
+		}
+	    }
+	  else if (is_gimple_assign (stmt))
+	    {
+	      m_dead_stmts.add (stmt);
+	      if (!gimple_clobber_p (stmt))
+		{
+		  tree lhs = gimple_assign_lhs (stmt);
+		  gcc_assert (TREE_CODE (lhs) == SSA_NAME);
+		  if (!m_dead_ssas.add (lhs))
+		    stack.safe_push (lhs);
+		}
+	    }
+	  else
+	    /* IPA-SRA does not analyze other types of statements.  */
+	    gcc_unreachable ();
+	}
+    }
+}
+
 /* Common initialization performed by all ipa_param_body_adjustments
    constructors.  OLD_FNDECL is the declaration we take original arguments
    from, (it may be the same as M_FNDECL).  VARS, if non-NULL, is a pointer to
@@ -1002,6 +1093,9 @@ ipa_param_body_adjustments::common_initialization (tree old_fndecl,
   auto_vec<bool, 16> kept;
   kept.reserve_exact (m_oparms.length ());
   kept.quick_grow_cleared (m_oparms.length ());
+  auto_vec<bool, 16> split;
+  split.reserve_exact (m_oparms.length ());
+  split.quick_grow_cleared (m_oparms.length ());
 
   unsigned adj_len = vec_safe_length (m_adj_params);
   m_method2func = ((TREE_CODE (TREE_TYPE (m_fndecl)) == METHOD_TYPE)
@@ -1047,6 +1141,7 @@ ipa_param_body_adjustments::common_initialization (tree old_fndecl,
 	  if (apm->op == IPA_PARAM_OP_SPLIT)
 	    {
 	      m_split_modifications_p = true;
+	      split[prev_index] = true;
 	      register_replacement (apm, new_parm);
 	    }
         }
@@ -1079,6 +1174,11 @@ ipa_param_body_adjustments::common_initialization (tree old_fndecl,
 		/* Declare this new variable.  */
 		DECL_CHAIN (var) = *vars;
 		*vars = var;
+
+		/* If this is not a split but a real removal, init hash sets
+		   that will guide what not to copy to the new body.  */
+		if (!split[i])
+		  mark_dead_statements (m_oparms[i]);
 	      }
 	  }
 	else
@@ -1135,9 +1235,10 @@ ipa_param_body_adjustments
 ::ipa_param_body_adjustments (vec<ipa_adjusted_param, va_gc> *adj_params,
 			      tree fndecl)
   : m_adj_params (adj_params), m_adjustments (NULL), m_reset_debug_decls (),
-    m_split_modifications_p (false), m_fndecl (fndecl), m_id (NULL),
-    m_oparms (), m_new_decls (), m_new_types (), m_replacements (),
-    m_removed_decls (), m_removed_map (), m_method2func (false)
+    m_split_modifications_p (false), m_dead_stmts (), m_dead_ssas (),
+    m_fndecl (fndecl), m_id (NULL), m_oparms (), m_new_decls (),
+    m_new_types (), m_replacements (), m_removed_decls (), m_removed_map (),
+    m_method2func (false)
 {
   common_initialization (fndecl, NULL, NULL);
 }
@@ -1151,9 +1252,9 @@ ipa_param_body_adjustments
 ::ipa_param_body_adjustments (ipa_param_adjustments *adjustments,
 			      tree fndecl)
   : m_adj_params (adjustments->m_adj_params), m_adjustments (adjustments),
-    m_reset_debug_decls (), m_split_modifications_p (false), m_fndecl (fndecl),
-    m_id (NULL), m_oparms (), m_new_decls (), m_new_types (),
-    m_replacements (), m_removed_decls (), m_removed_map (),
+    m_reset_debug_decls (), m_split_modifications_p (false), m_dead_stmts (),
+    m_dead_ssas (), m_fndecl (fndecl), m_id (NULL), m_oparms (), m_new_decls (),
+    m_new_types (), m_replacements (), m_removed_decls (), m_removed_map (),
     m_method2func (false)
 {
   common_initialization (fndecl, NULL, NULL);
@@ -1174,9 +1275,10 @@ ipa_param_body_adjustments
 			      copy_body_data *id, tree *vars,
 			      vec<ipa_replace_map *, va_gc> *tree_map)
   : m_adj_params (adjustments->m_adj_params), m_adjustments (adjustments),
-    m_reset_debug_decls (), m_split_modifications_p (false), m_fndecl (fndecl),
-    m_id (id), m_oparms (), m_new_decls (), m_new_types (), m_replacements (),
-    m_removed_decls (), m_removed_map (), m_method2func (false)
+    m_reset_debug_decls (), m_split_modifications_p (false), m_dead_stmts (),
+    m_dead_ssas (),m_fndecl (fndecl), m_id (id), m_oparms (), m_new_decls (),
+    m_new_types (), m_replacements (), m_removed_decls (), m_removed_map (),
+    m_method2func (false)
 {
   common_initialization (old_fndecl, vars, tree_map);
 }
@@ -1623,8 +1725,9 @@ ipa_param_body_adjustments::modify_call_stmt (gcall **stmt_p,
 		  && TREE_CODE (t) != IMAGPART_EXPR
 		  && TREE_CODE (t) != REALPART_EXPR);
 
-      /* The follow-up patch will check whether t needs to be removed, that's
-	 why this condition is in the loop.  */
+      if (TREE_CODE (t) == SSA_NAME
+	  && m_dead_ssas.contains (t))
+	recreate = true;
 
       if (!m_split_modifications_p)
 	continue;
@@ -1762,10 +1865,19 @@ ipa_param_body_adjustments::modify_call_stmt (gcall **stmt_p,
       else
 	{
 	  tree t = gimple_call_arg (stmt, i);
-	  modify_expression (&t, true);
-	  vargs.safe_push (t);
-	  index_map.safe_push (new_arg_idx);
-	  new_arg_idx++;
+	  if (TREE_CODE (t) == SSA_NAME
+	      && m_dead_ssas.contains (t))
+	    {
+	      always_copy_delta--;
+	      index_map.safe_push (-1);
+	    }
+	  else
+	    {
+	      modify_expression (&t, true);
+	      vargs.safe_push (t);
+	      index_map.safe_push (new_arg_idx);
+	      new_arg_idx++;
+	    }
 	}
     }
 
diff --git a/gcc/ipa-param-manipulation.h b/gcc/ipa-param-manipulation.h
index fd0df7b299c..17e20aff3ca 100644
--- a/gcc/ipa-param-manipulation.h
+++ b/gcc/ipa-param-manipulation.h
@@ -342,6 +342,12 @@ public:
   /* Set to true if there are any IPA_PARAM_OP_SPLIT adjustments among stored
      adjustments.  */
   bool m_split_modifications_p;
+
+  /* Sets of statements and SSA_NAMEs that only manipulate data from parameters
+     removed because they are not necessary.  */
+  hash_set<gimple *> m_dead_stmts;
+  hash_set<tree> m_dead_ssas;
+
 private:
   void common_initialization (tree old_fndecl, tree *vars,
 			      vec<ipa_replace_map *, va_gc> *tree_map);
diff --git a/gcc/testsuite/g++.dg/ipa/ipa-sra-4.C b/gcc/testsuite/g++.dg/ipa/ipa-sra-4.C
new file mode 100644
index 00000000000..56d59f9fd9a
--- /dev/null
+++ b/gcc/testsuite/g++.dg/ipa/ipa-sra-4.C
@@ -0,0 +1,37 @@
+/* { dg-do compile { target c++11 } } */
+/* { dg-options "-O2 -fipa-sra"  } */
+
+void __throw_bad_alloc() __attribute__((__noreturn__));
+void __throw_bad_array_new_length();
+template <typename> class allocator {};
+template <typename> struct allocator_traits;
+int *allocate___trans_tmp_2;
+template <typename _Tp> struct allocator_traits<allocator<_Tp>> {
+  using allocator_type = allocator<_Tp>;
+  using pointer = _Tp *;
+  using size_type = long;
+  static pointer allocate(allocator_type &, size_type __n) {
+    long __trans_tmp_3 = __n;
+    if (__builtin_expect(__trans_tmp_3, false))
+      if (__trans_tmp_3)
+        __throw_bad_array_new_length();
+    operator new(sizeof(int));
+    return allocate___trans_tmp_2;
+  }
+};
+class throw_allocator_base {
+  allocator<int> _M_allocator;
+public:
+  int *allocate(long __n) {
+    if (__n)
+      __throw_bad_alloc();
+    int *a = allocator_traits<allocator<int>>::allocate(_M_allocator, __n);
+    return a;
+  }
+};
+template <typename Alloc> void check_allocate_max_size() {
+  Alloc a;
+  long __trans_tmp_1 = 0;
+  a.allocate(__trans_tmp_1 + 1);
+}
+int main() { check_allocate_max_size<throw_allocator_base>(); }
diff --git a/gcc/testsuite/gcc.dg/ipa/ipa-sra-23.c b/gcc/testsuite/gcc.dg/ipa/ipa-sra-23.c
new file mode 100644
index 00000000000..f438b509614
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/ipa/ipa-sra-23.c
@@ -0,0 +1,24 @@
+/* { dg-do compile } */
+/* { dg-options "-O2"  } */
+
+extern int g;
+
+static int __attribute__((noinline))
+bar (int i, int j)
+{
+  return 2*g + i;
+}
+
+static int __attribute__((noinline))
+foo (int i, int j)
+{
+  if (i > 5)
+    j = 22;
+  return bar (i, j) + 1;
+}
+
+int
+entry (int l, int k)
+{
+  return foo (l, k);
+}
diff --git a/gcc/testsuite/gcc.dg/ipa/ipa-sra-24.c b/gcc/testsuite/gcc.dg/ipa/ipa-sra-24.c
new file mode 100644
index 00000000000..7b5bf0825fc
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/ipa/ipa-sra-24.c
@@ -0,0 +1,20 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -Wmaybe-uninitialized -Werror"  } */
+
+int *ttmp_1;
+_Bool pt_ins_tipdo, pq_ins_apd, pq_ins_tt2;
+int gtrphdt;
+
+void pl_ins(int, _Bool, _Bool);
+inline void pt_ins(int *, _Bool apdo) {
+  int list = *ttmp_1;
+  pl_ins(list, apdo, pt_ins_tipdo);
+}
+void pq_ins(int *t) {
+  if (pq_ins_tt2)
+    pt_ins(t, pq_ins_apd);
+}
+int gtr_post_hd() {
+  pq_ins(&gtrphdt);
+  return 0;
+}
diff --git a/gcc/testsuite/gcc.dg/ipa/pr93385.c b/gcc/testsuite/gcc.dg/ipa/pr93385.c
new file mode 100644
index 00000000000..6d1d0d7cd27
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/ipa/pr93385.c
@@ -0,0 +1,27 @@
+/* { dg-do run } */
+/* { dg-options "-O2 -fno-dce -fno-ipa-cp -fno-tree-dce" } */
+
+char a, b;
+
+#ifdef __SIZEOF_INT128__
+#define T unsigned __int128
+#else
+#define T unsigned
+#endif
+
+static inline int
+c (T d)
+{
+  char e = 0;
+  d %= (unsigned) d;
+  e -= 0;
+  __builtin_strncpy (&a, &e, 1);
+  return e + b;
+}
+
+int
+main (void)
+{
+  c (~0);
+  return 0;
+}
diff --git a/gcc/tree-inline.c b/gcc/tree-inline.c
index e2fb6be681c..cad11eeae17 100644
--- a/gcc/tree-inline.c
+++ b/gcc/tree-inline.c
@@ -1504,6 +1504,11 @@ remap_gimple_stmt (gimple *stmt, copy_body_data *id)
 	  : !opt_for_fn (id->dst_fn, flag_var_tracking_assignments)))
     return NULL;
 
+  if (!is_gimple_debug (stmt)
+      && id->param_body_adjs
+      && id->param_body_adjs->m_dead_stmts.contains (stmt))
+    return NULL;
+
   /* Begin by recognizing trees that we'll completely rewrite for the
      inlining context.  Our output for these trees is completely
      different from our input (e.g. RETURN_EXPR is deleted and morphs
@@ -1768,10 +1773,15 @@ remap_gimple_stmt (gimple *stmt, copy_body_data *id)
 
       if (gimple_debug_bind_p (stmt))
 	{
+	  tree value;
+	  if (id->param_body_adjs
+	      && id->param_body_adjs->m_dead_stmts.contains (stmt))
+	    value = NULL_TREE;
+	  else
+	    value = gimple_debug_bind_get_value (stmt);
 	  gdebug *copy
 	    = gimple_build_debug_bind (gimple_debug_bind_get_var (stmt),
-				       gimple_debug_bind_get_value (stmt),
-				       stmt);
+				       value, stmt);
 	  if (id->reset_location)
 	    gimple_set_location (copy, input_location);
 	  id->debug_stmts.safe_push (copy);
@@ -2650,7 +2660,9 @@ copy_phis_for_bb (basic_block bb, copy_body_data *id)
       phi = si.phi ();
       res = PHI_RESULT (phi);
       new_res = res;
-      if (!virtual_operand_p (res))
+      if (!virtual_operand_p (res)
+	  && (!id->param_body_adjs
+	      || !id->param_body_adjs->m_dead_stmts.contains (phi)))
 	{
 	  walk_tree (&new_res, copy_tree_body_r, id, NULL);
 	  if (EDGE_COUNT (new_bb->preds) == 0)
-- 
2.31.1
Andre Vehreschild via Gcc-patches May 11, 2021, 12:36 p.m. | #4
On Mon, May 10, 2021 at 8:52 PM Martin Jambor <mjambor@suse.cz> wrote:
>

> Hi,

>

> On Mon, May 10 2021, Richard Biener wrote:

> > I've tried to have a look at this patch but it does a lot of IPA specific

> > refactoring(?), so the actual DCE bits are hard to find.  Is it possible

> > to split the patch up or is it too entangled?

> >

>

> Yes:

>

> I was asked by Richi to split my fix for PR 93385 for easier review

> into IPA-SRA materialization refactoring and the actual DCE addition.

> This is the second part that actually contains the DCE of statements

> that IPA-SRA should not leave behind because they can have problematic

> side effects, even if they are useless, so that we do not depend on

> tree-dce to remove them for correctness.

>

> The patch fixes the problem by doing a def-use walk when materializing

> clones, marking which statements should not be copied and which

> SSA_NAMEs do not need to be computed because eventually they would be

> DCEd.  We do this on the original function body and tree-inline simply

> does not copy statements which are "dead."

>

> The only complication is removing dead argument calls because that

> needs to be communicated to callee redirection code using the

> infrastructure introduced by the previous patch.

>

> I added all testcases of the original patch to this one, although some

> probably test behavior introduced in the previous patch.

>

> The patch is so far only lightly tested but I have verified that

> together with the second one they make up pretty much exactly the

> original one (modulo m_new_call_arg_modification_info) which I did

> bootstrap this morning.  I will of course bootstrap it independently

> too.

>

> What do you think?

>

> Martin

>

>

> gcc/ChangeLog:

>

> 2021-05-10  Martin Jambor  <mjambor@suse.cz>

>

>         PR ipa/93385

>         * ipa-param-manipulation.h (class ipa_param_body_adjustments): New

>         members m_dead_stmts and m_dead_ssas.

>         * ipa-param-manipulation.c (phi_arg_will_live_p): New function.

>         (ipa_param_body_adjustments::mark_dead_statements): Likwise.

>         (ipa_param_body_adjustments::common_initialization): Call it on

>         all removed but not split parameters.

>         (ipa_param_body_adjustments::ipa_param_body_adjustments): Initialize

>         new mwmbers.

>         (ipa_param_body_adjustments::modify_call_stmt): Remove arguments that

>         are dead.

>         * tree-inline.c (remap_gimple_stmt): Do not copy dead statements, reset

>         dead debug statements.

>         (copy_phis_for_bb): Do not copy dead PHI nodes.

>

> gcc/testsuite/ChangeLog:

>

> 2021-03-22  Martin Jambor  <mjambor@suse.cz>

>

>         PR ipa/93385

>         * gcc.dg/ipa/pr93385.c: New test.

>         * gcc.dg/ipa/ipa-sra-23.c: Likewise.

>         * gcc.dg/ipa/ipa-sra-24.c: Likewise.

>         * g++.dg/ipa/ipa-sra-4.C: Likewise.

> ---

>  gcc/ipa-param-manipulation.c          | 142 +++++++++++++++++++++++---

>  gcc/ipa-param-manipulation.h          |   6 ++

>  gcc/testsuite/g++.dg/ipa/ipa-sra-4.C  |  37 +++++++

>  gcc/testsuite/gcc.dg/ipa/ipa-sra-23.c |  24 +++++

>  gcc/testsuite/gcc.dg/ipa/ipa-sra-24.c |  20 ++++

>  gcc/testsuite/gcc.dg/ipa/pr93385.c    |  27 +++++

>  gcc/tree-inline.c                     |  18 +++-

>  7 files changed, 256 insertions(+), 18 deletions(-)

>  create mode 100644 gcc/testsuite/g++.dg/ipa/ipa-sra-4.C

>  create mode 100644 gcc/testsuite/gcc.dg/ipa/ipa-sra-23.c

>  create mode 100644 gcc/testsuite/gcc.dg/ipa/ipa-sra-24.c

>  create mode 100644 gcc/testsuite/gcc.dg/ipa/pr93385.c

>

> diff --git a/gcc/ipa-param-manipulation.c b/gcc/ipa-param-manipulation.c

> index 424b8e5343f..d7d73542856 100644

> --- a/gcc/ipa-param-manipulation.c

> +++ b/gcc/ipa-param-manipulation.c

> @@ -969,6 +969,97 @@ ipa_param_body_adjustments::carry_over_param (tree t)

>    return new_parm;

>  }

>

> +/* Return true if BLOCKS_TO_COPY is NULL or if PHI has an argument ARG in

> +   position that corresponds to an edge that is coming from a block that has

> +   the corresponding bit set in BLOCKS_TO_COPY.  */

> +

> +static bool

> +phi_arg_will_live_p (gphi *phi, bitmap blocks_to_copy, tree arg)

> +{

> +  bool arg_will_survive = false;

> +  if (!blocks_to_copy)

> +    arg_will_survive = true;

> +  else

> +    for (unsigned i = 0; i < gimple_phi_num_args (phi); i++)

> +      if (gimple_phi_arg_def (phi, i) == arg


I think this is prone to quadratic, it would be nice to use the
faster FOR_EACH_IMM_USE_FAST () below and then
phi_arg_index_from_use () to get to the corresponding edge
directly - this would remove the loop over PHI args here and
you can then inline the function below.

> +         && bitmap_bit_p (blocks_to_copy,

> +                          gimple_phi_arg_edge (phi, i)->src->index))

> +       {

> +         arg_will_survive = true;

> +         break;

> +       }

> +  return arg_will_survive;

> +}

> +

> +/* Populate m_dead_stmts given that DEAD_PARAM is going to be removed without

> +   any replacement or splitting.  REPL is the replacement VAR_SECL to base any

> +   remaining uses of a removed parameter on.  */

> +

> +void

> +ipa_param_body_adjustments::mark_dead_statements (tree dead_param)

> +{

> +  /* Current IPA analyses which remove unused parameters never remove a

> +     non-gimple register ones which have any use except as parameters in other

> +     calls, so we can safely leve them as they are.  */

> +  if (!is_gimple_reg (dead_param))

> +    return;

> +  tree parm_ddef = ssa_default_def (m_id->src_cfun, dead_param);

> +  if (!parm_ddef || has_zero_uses (parm_ddef))

> +    return;

> +

> +  auto_vec<tree, 4> stack;

> +  m_dead_ssas.add (parm_ddef);

> +  stack.safe_push (parm_ddef);

> +  while (!stack.is_empty ())

> +    {

> +      tree t = stack.pop ();

> +

> +      imm_use_iterator imm_iter;

> +      gimple *stmt;

> +

> +      insert_decl_map (m_id, t, error_mark_node);

> +      FOR_EACH_IMM_USE_STMT (stmt, imm_iter, t)

> +       {

> +         if (is_gimple_call (stmt)


(*) so we just ignore dead calls?  That is, there might be
a const call like

   _1 = foo (removed_param_2);

and followup important to be removed uses of _1?  Above
you say that eventual IPA SRA argument removal is dealt
with but this still leaves the const/pure call case.  Unless
IPA SRA bails on them, of course.

Can you add a comment like

/* IPA SRA only handles dead arguments in calls when it
   removes those arguments from the called function.  The
   IPA machinery arranges for fixup here.  */

> +             || (m_id->blocks_to_copy

> +                 && !bitmap_bit_p (m_id->blocks_to_copy,

> +                                   gimple_bb (stmt)->index)))

> +           continue;

> +

> +         if (is_gimple_debug (stmt))

> +           {

> +             m_dead_stmts.add (stmt);

> +             gcc_assert (gimple_debug_bind_p (stmt));

> +           }

> +         else if (gimple_code (stmt) == GIMPLE_PHI)

> +           {

> +             gphi *phi = as_a <gphi *> (stmt);

> +             if (phi_arg_will_live_p (phi, m_id->blocks_to_copy, t))

> +               {

> +                 m_dead_stmts.add (phi);

> +                 tree res = gimple_phi_result (phi);

> +                 if (!m_dead_ssas.add (res))

> +                   stack.safe_push (res);

> +               }

> +           }

> +         else if (is_gimple_assign (stmt))

> +           {

> +             m_dead_stmts.add (stmt);

> +             if (!gimple_clobber_p (stmt))

> +               {

> +                 tree lhs = gimple_assign_lhs (stmt);

> +                 gcc_assert (TREE_CODE (lhs) == SSA_NAME);


I don't think you can assert this?  Well, maybe you can because
IPA prop would have refused to mark the param dead?  I'm
thinking about stores here.  I'd have leaned towards instead
guarding the m_dead_ssas.add with TREE_CODE (lhs) == SSA_NAME
but this then leaves possibly "dead" code around when it is not
an SSA name.

> +                 if (!m_dead_ssas.add (lhs))

> +                   stack.safe_push (lhs);

> +               }

> +           }

> +         else

> +           /* IPA-SRA does not analyze other types of statements.  */

> +           gcc_unreachable ();


So I guess fine in this light.  But (*) above.

Otherwise looks OK to me.

Richard.

> +       }

> +    }

> +}

> +

>  /* Common initialization performed by all ipa_param_body_adjustments

>     constructors.  OLD_FNDECL is the declaration we take original arguments

>     from, (it may be the same as M_FNDECL).  VARS, if non-NULL, is a pointer to

> @@ -1002,6 +1093,9 @@ ipa_param_body_adjustments::common_initialization (tree old_fndecl,

>    auto_vec<bool, 16> kept;

>    kept.reserve_exact (m_oparms.length ());

>    kept.quick_grow_cleared (m_oparms.length ());

> +  auto_vec<bool, 16> split;

> +  split.reserve_exact (m_oparms.length ());

> +  split.quick_grow_cleared (m_oparms.length ());

>

>    unsigned adj_len = vec_safe_length (m_adj_params);

>    m_method2func = ((TREE_CODE (TREE_TYPE (m_fndecl)) == METHOD_TYPE)

> @@ -1047,6 +1141,7 @@ ipa_param_body_adjustments::common_initialization (tree old_fndecl,

>           if (apm->op == IPA_PARAM_OP_SPLIT)

>             {

>               m_split_modifications_p = true;

> +             split[prev_index] = true;

>               register_replacement (apm, new_parm);

>             }

>          }

> @@ -1079,6 +1174,11 @@ ipa_param_body_adjustments::common_initialization (tree old_fndecl,

>                 /* Declare this new variable.  */

>                 DECL_CHAIN (var) = *vars;

>                 *vars = var;

> +

> +               /* If this is not a split but a real removal, init hash sets

> +                  that will guide what not to copy to the new body.  */

> +               if (!split[i])

> +                 mark_dead_statements (m_oparms[i]);

>               }

>           }

>         else

> @@ -1135,9 +1235,10 @@ ipa_param_body_adjustments

>  ::ipa_param_body_adjustments (vec<ipa_adjusted_param, va_gc> *adj_params,

>                               tree fndecl)

>    : m_adj_params (adj_params), m_adjustments (NULL), m_reset_debug_decls (),

> -    m_split_modifications_p (false), m_fndecl (fndecl), m_id (NULL),

> -    m_oparms (), m_new_decls (), m_new_types (), m_replacements (),

> -    m_removed_decls (), m_removed_map (), m_method2func (false)

> +    m_split_modifications_p (false), m_dead_stmts (), m_dead_ssas (),

> +    m_fndecl (fndecl), m_id (NULL), m_oparms (), m_new_decls (),

> +    m_new_types (), m_replacements (), m_removed_decls (), m_removed_map (),

> +    m_method2func (false)

>  {

>    common_initialization (fndecl, NULL, NULL);

>  }

> @@ -1151,9 +1252,9 @@ ipa_param_body_adjustments

>  ::ipa_param_body_adjustments (ipa_param_adjustments *adjustments,

>                               tree fndecl)

>    : m_adj_params (adjustments->m_adj_params), m_adjustments (adjustments),

> -    m_reset_debug_decls (), m_split_modifications_p (false), m_fndecl (fndecl),

> -    m_id (NULL), m_oparms (), m_new_decls (), m_new_types (),

> -    m_replacements (), m_removed_decls (), m_removed_map (),

> +    m_reset_debug_decls (), m_split_modifications_p (false), m_dead_stmts (),

> +    m_dead_ssas (), m_fndecl (fndecl), m_id (NULL), m_oparms (), m_new_decls (),

> +    m_new_types (), m_replacements (), m_removed_decls (), m_removed_map (),

>      m_method2func (false)

>  {

>    common_initialization (fndecl, NULL, NULL);

> @@ -1174,9 +1275,10 @@ ipa_param_body_adjustments

>                               copy_body_data *id, tree *vars,

>                               vec<ipa_replace_map *, va_gc> *tree_map)

>    : m_adj_params (adjustments->m_adj_params), m_adjustments (adjustments),

> -    m_reset_debug_decls (), m_split_modifications_p (false), m_fndecl (fndecl),

> -    m_id (id), m_oparms (), m_new_decls (), m_new_types (), m_replacements (),

> -    m_removed_decls (), m_removed_map (), m_method2func (false)

> +    m_reset_debug_decls (), m_split_modifications_p (false), m_dead_stmts (),

> +    m_dead_ssas (),m_fndecl (fndecl), m_id (id), m_oparms (), m_new_decls (),

> +    m_new_types (), m_replacements (), m_removed_decls (), m_removed_map (),

> +    m_method2func (false)

>  {

>    common_initialization (old_fndecl, vars, tree_map);

>  }

> @@ -1623,8 +1725,9 @@ ipa_param_body_adjustments::modify_call_stmt (gcall **stmt_p,

>                   && TREE_CODE (t) != IMAGPART_EXPR

>                   && TREE_CODE (t) != REALPART_EXPR);

>

> -      /* The follow-up patch will check whether t needs to be removed, that's

> -        why this condition is in the loop.  */

> +      if (TREE_CODE (t) == SSA_NAME

> +         && m_dead_ssas.contains (t))

> +       recreate = true;

>

>        if (!m_split_modifications_p)

>         continue;

> @@ -1762,10 +1865,19 @@ ipa_param_body_adjustments::modify_call_stmt (gcall **stmt_p,

>        else

>         {

>           tree t = gimple_call_arg (stmt, i);

> -         modify_expression (&t, true);

> -         vargs.safe_push (t);

> -         index_map.safe_push (new_arg_idx);

> -         new_arg_idx++;

> +         if (TREE_CODE (t) == SSA_NAME

> +             && m_dead_ssas.contains (t))

> +           {

> +             always_copy_delta--;

> +             index_map.safe_push (-1);

> +           }

> +         else

> +           {

> +             modify_expression (&t, true);

> +             vargs.safe_push (t);

> +             index_map.safe_push (new_arg_idx);

> +             new_arg_idx++;

> +           }

>         }

>      }

>

> diff --git a/gcc/ipa-param-manipulation.h b/gcc/ipa-param-manipulation.h

> index fd0df7b299c..17e20aff3ca 100644

> --- a/gcc/ipa-param-manipulation.h

> +++ b/gcc/ipa-param-manipulation.h

> @@ -342,6 +342,12 @@ public:

>    /* Set to true if there are any IPA_PARAM_OP_SPLIT adjustments among stored

>       adjustments.  */

>    bool m_split_modifications_p;

> +

> +  /* Sets of statements and SSA_NAMEs that only manipulate data from parameters

> +     removed because they are not necessary.  */

> +  hash_set<gimple *> m_dead_stmts;

> +  hash_set<tree> m_dead_ssas;

> +

>  private:

>    void common_initialization (tree old_fndecl, tree *vars,

>                               vec<ipa_replace_map *, va_gc> *tree_map);

> diff --git a/gcc/testsuite/g++.dg/ipa/ipa-sra-4.C b/gcc/testsuite/g++.dg/ipa/ipa-sra-4.C

> new file mode 100644

> index 00000000000..56d59f9fd9a

> --- /dev/null

> +++ b/gcc/testsuite/g++.dg/ipa/ipa-sra-4.C

> @@ -0,0 +1,37 @@

> +/* { dg-do compile { target c++11 } } */

> +/* { dg-options "-O2 -fipa-sra"  } */

> +

> +void __throw_bad_alloc() __attribute__((__noreturn__));

> +void __throw_bad_array_new_length();

> +template <typename> class allocator {};

> +template <typename> struct allocator_traits;

> +int *allocate___trans_tmp_2;

> +template <typename _Tp> struct allocator_traits<allocator<_Tp>> {

> +  using allocator_type = allocator<_Tp>;

> +  using pointer = _Tp *;

> +  using size_type = long;

> +  static pointer allocate(allocator_type &, size_type __n) {

> +    long __trans_tmp_3 = __n;

> +    if (__builtin_expect(__trans_tmp_3, false))

> +      if (__trans_tmp_3)

> +        __throw_bad_array_new_length();

> +    operator new(sizeof(int));

> +    return allocate___trans_tmp_2;

> +  }

> +};

> +class throw_allocator_base {

> +  allocator<int> _M_allocator;

> +public:

> +  int *allocate(long __n) {

> +    if (__n)

> +      __throw_bad_alloc();

> +    int *a = allocator_traits<allocator<int>>::allocate(_M_allocator, __n);

> +    return a;

> +  }

> +};

> +template <typename Alloc> void check_allocate_max_size() {

> +  Alloc a;

> +  long __trans_tmp_1 = 0;

> +  a.allocate(__trans_tmp_1 + 1);

> +}

> +int main() { check_allocate_max_size<throw_allocator_base>(); }

> diff --git a/gcc/testsuite/gcc.dg/ipa/ipa-sra-23.c b/gcc/testsuite/gcc.dg/ipa/ipa-sra-23.c

> new file mode 100644

> index 00000000000..f438b509614

> --- /dev/null

> +++ b/gcc/testsuite/gcc.dg/ipa/ipa-sra-23.c

> @@ -0,0 +1,24 @@

> +/* { dg-do compile } */

> +/* { dg-options "-O2"  } */

> +

> +extern int g;

> +

> +static int __attribute__((noinline))

> +bar (int i, int j)

> +{

> +  return 2*g + i;

> +}

> +

> +static int __attribute__((noinline))

> +foo (int i, int j)

> +{

> +  if (i > 5)

> +    j = 22;

> +  return bar (i, j) + 1;

> +}

> +

> +int

> +entry (int l, int k)

> +{

> +  return foo (l, k);

> +}

> diff --git a/gcc/testsuite/gcc.dg/ipa/ipa-sra-24.c b/gcc/testsuite/gcc.dg/ipa/ipa-sra-24.c

> new file mode 100644

> index 00000000000..7b5bf0825fc

> --- /dev/null

> +++ b/gcc/testsuite/gcc.dg/ipa/ipa-sra-24.c

> @@ -0,0 +1,20 @@

> +/* { dg-do compile } */

> +/* { dg-options "-O2 -Wmaybe-uninitialized -Werror"  } */

> +

> +int *ttmp_1;

> +_Bool pt_ins_tipdo, pq_ins_apd, pq_ins_tt2;

> +int gtrphdt;

> +

> +void pl_ins(int, _Bool, _Bool);

> +inline void pt_ins(int *, _Bool apdo) {

> +  int list = *ttmp_1;

> +  pl_ins(list, apdo, pt_ins_tipdo);

> +}

> +void pq_ins(int *t) {

> +  if (pq_ins_tt2)

> +    pt_ins(t, pq_ins_apd);

> +}

> +int gtr_post_hd() {

> +  pq_ins(&gtrphdt);

> +  return 0;

> +}

> diff --git a/gcc/testsuite/gcc.dg/ipa/pr93385.c b/gcc/testsuite/gcc.dg/ipa/pr93385.c

> new file mode 100644

> index 00000000000..6d1d0d7cd27

> --- /dev/null

> +++ b/gcc/testsuite/gcc.dg/ipa/pr93385.c

> @@ -0,0 +1,27 @@

> +/* { dg-do run } */

> +/* { dg-options "-O2 -fno-dce -fno-ipa-cp -fno-tree-dce" } */

> +

> +char a, b;

> +

> +#ifdef __SIZEOF_INT128__

> +#define T unsigned __int128

> +#else

> +#define T unsigned

> +#endif

> +

> +static inline int

> +c (T d)

> +{

> +  char e = 0;

> +  d %= (unsigned) d;

> +  e -= 0;

> +  __builtin_strncpy (&a, &e, 1);

> +  return e + b;

> +}

> +

> +int

> +main (void)

> +{

> +  c (~0);

> +  return 0;

> +}

> diff --git a/gcc/tree-inline.c b/gcc/tree-inline.c

> index e2fb6be681c..cad11eeae17 100644

> --- a/gcc/tree-inline.c

> +++ b/gcc/tree-inline.c

> @@ -1504,6 +1504,11 @@ remap_gimple_stmt (gimple *stmt, copy_body_data *id)

>           : !opt_for_fn (id->dst_fn, flag_var_tracking_assignments)))

>      return NULL;

>

> +  if (!is_gimple_debug (stmt)

> +      && id->param_body_adjs

> +      && id->param_body_adjs->m_dead_stmts.contains (stmt))

> +    return NULL;

> +

>    /* Begin by recognizing trees that we'll completely rewrite for the

>       inlining context.  Our output for these trees is completely

>       different from our input (e.g. RETURN_EXPR is deleted and morphs

> @@ -1768,10 +1773,15 @@ remap_gimple_stmt (gimple *stmt, copy_body_data *id)

>

>        if (gimple_debug_bind_p (stmt))

>         {

> +         tree value;

> +         if (id->param_body_adjs

> +             && id->param_body_adjs->m_dead_stmts.contains (stmt))

> +           value = NULL_TREE;

> +         else

> +           value = gimple_debug_bind_get_value (stmt);

>           gdebug *copy

>             = gimple_build_debug_bind (gimple_debug_bind_get_var (stmt),

> -                                      gimple_debug_bind_get_value (stmt),

> -                                      stmt);

> +                                      value, stmt);

>           if (id->reset_location)

>             gimple_set_location (copy, input_location);

>           id->debug_stmts.safe_push (copy);

> @@ -2650,7 +2660,9 @@ copy_phis_for_bb (basic_block bb, copy_body_data *id)

>        phi = si.phi ();

>        res = PHI_RESULT (phi);

>        new_res = res;

> -      if (!virtual_operand_p (res))

> +      if (!virtual_operand_p (res)

> +         && (!id->param_body_adjs

> +             || !id->param_body_adjs->m_dead_stmts.contains (phi)))

>         {

>           walk_tree (&new_res, copy_tree_body_r, id, NULL);

>           if (EDGE_COUNT (new_bb->preds) == 0)

> --

> 2.31.1

>
Martin Jambor May 21, 2021, 3:49 p.m. | #5
Hi,

this is a PING of the following patch, which however also now got two
fixes, it deallocated the newly added summary in toplev::finalize and
fixes a mistakenly uninitialized field (dummy, used by OpenMP SIMD
cloning).

The subsequent patch which actually deals with the PR has already been
approved by Richi, so this is the one holding it up:


I was asked by Richi to split my fix for PR 93385 for easier review
into IPA-SRA materialization refactoring and the actual DCE addition.
Fortunately it was mostly natural except for a temporary weird
condition in ipa_param_body_adjustments::modify_call_stmt.
Additionally.

This is the first part which basically replaces performed_splits in
clone_info and the code which generates it, keeps it up-to-date and
consumes it with new edge summaries which are much nicer.  It simply
contains 1) a mapping from the original argument indices to the actual
indices in the call statement as it is now, 2) information needed to
identify arguments representing pass-through IPA-SRA splits with which
have been added to the call arguments in place of an original
argument/reference and 3) a delta to the index where va_args may start
- so basically directly all the information that the consumer of
performed_splits had to compute and we also do not need the weird
dummy declarations.

The main disadvantage is that the information has to be created (and
kept up-to-date) for all call graph edges associated with the given
statement from all clones (including inline clones) of the clone where
splitting or removal happened first.  But all of this happens during
clone materialization so the only effect on WPA memory consumption is
the removal of a pointer from clone_info.

The statement modification code also has to know the statement from
the original function in order to be able to locate the edge summaries
which at this point are still keyed to these.  However, the code is
already quite heavily dependant on how things are structured in
tree-inline.c and in order to fix bugs like these it probably has to
be.

The subsequent patch needs this new information to be able to remove
arguments from calls during materialization and communicate this
information to the call redirection.

Bootstrapped and tested on x86_64-linux.  Together with other patches I
also did that on i686-linux and aarch64-linux and (profiled)
LTO-bootstrapped it on x86_64-linux.

OK for trunk?

Thanks,

Martin


2021-05-19  Martin Jambor  <mjambor@suse.cz>

	PR ipa/93385
	* symtab-clones.h (clone_info): Removed member param_adjustments.
	* ipa-param-manipulation.h: Adjust initial comment to reflect how we
	deal with pass-through splits now.
	(ipa_param_performed_split): Removed.
	(ipa_param_adjustments::modify_call): Adjusted parameters.
	(class ipa_param_body_adjustments): Adjusted parameters of
	register_replacement, modify_gimple_stmt and modify_call_stmt.
	(ipa_verify_edge_has_no_modifications): Declare.
	(ipa_edge_modifications_finalize): Declare.
	* cgraph.c (cgraph_edge::redirect_call_stmt_to_callee): Remove
	performed_splits processing, pas only edge to padjs->modify_call,
	check that call arguments were not modified if they should not have
	been.
	* cgraphclones.c (cgraph_node::create_clone): Do not copy performed
	splits.
	* ipa-param-manipulation.c (struct pass_through_split_map): New type.
	(ipa_edge_modification_info): Likewise.
	(ipa_edge_modification_sum): Likewise.
	(ipa_edge_modifications): New edge summary.
	(ipa_verify_edge_has_no_modifications): New function.
	(transitive_split_p): Removed.
	(transitive_split_map): Likewise.
	(init_transitive_splits): Likewise.
	(ipa_param_adjustments::modify_call): Adjusted to use the new edge
	summary instead of performed_splits.
	(ipa_param_body_adjustments::register_replacement): Drop dummy
	parameter, set base_index of the created ipa_param_body_replacement.
	(phi_arg_will_live_p): New function.
	(ipa_param_body_adjustments::common_initialization): Do not create
	IPA_SRA dummy decls.
	(simple_tree_swap_info): Removed.
	(remap_split_decl_to_dummy): Likewise.
	(record_argument_state_1): New function.
	(record_argument_state): Likewise.
	(ipa_param_body_adjustments::modify_call_stmt): New parameter
	orig_stmt.  Do not work with dummy decls, save necessary info about
	changes to ipa_edge_modifications.
	(ipa_param_body_adjustments::modify_gimple_stmt): New parameter
	orig_stmt, pass it to modify_call_stmt.
	(ipa_param_body_adjustments::modify_cfun_body): Adjust call to
	modify_gimple_stmt.
	(ipa_edge_modifications_finalize): New function.
	* tree-inline.c (remap_gimple_stmt): Pass original statement to
	modify_gimple_stmt.
	(copy_phis_for_bb): Do not copy dead PHI nodes.
	(expand_call_inline): Do not remap performed_splits.
	(update_clone_info): Likewise.
	* toplev.c: Include ipa-param-manipulation.h.
	(toplev::finalize): Call ipa_edge_modifications_finalize.
---
 gcc/cgraph.c                 |  22 +-
 gcc/cgraphclones.c           |   3 -
 gcc/ipa-param-manipulation.c | 803 +++++++++++++++++++----------------
 gcc/ipa-param-manipulation.h |  82 ++--
 gcc/symtab-clones.h          |  15 +-
 gcc/toplev.c                 |   2 +
 gcc/tree-inline.c            | 103 +----
 7 files changed, 485 insertions(+), 545 deletions(-)

diff --git a/gcc/cgraph.c b/gcc/cgraph.c
index d7c78d518bc..d473da5a325 100644
--- a/gcc/cgraph.c
+++ b/gcc/cgraph.c
@@ -1506,8 +1506,6 @@ cgraph_edge::redirect_call_stmt_to_callee (cgraph_edge *e)
     }
 
   clone_info *callee_info = clone_info::get (e->callee);
-  clone_info *caller_info = clone_info::get (e->caller);
-
   if (symtab->dump_file)
     {
       fprintf (symtab->dump_file, "updating call of %s -> %s: ",
@@ -1515,18 +1513,6 @@ cgraph_edge::redirect_call_stmt_to_callee (cgraph_edge *e)
       print_gimple_stmt (symtab->dump_file, e->call_stmt, 0, dump_flags);
       if (callee_info && callee_info->param_adjustments)
 	callee_info->param_adjustments->dump (symtab->dump_file);
-      unsigned performed_len
-	= caller_info ? vec_safe_length (caller_info->performed_splits) : 0;
-      if (performed_len > 0)
-	fprintf (symtab->dump_file, "Performed splits records:\n");
-      for (unsigned i = 0; i < performed_len; i++)
-	{
-	  ipa_param_performed_split *sm
-	    = &(*caller_info->performed_splits)[i];
-	  print_node_brief (symtab->dump_file, "  dummy_decl: ", sm->dummy_decl,
-			    TDF_UID);
-	  fprintf (symtab->dump_file, ", unit_offset: %u\n", sm->unit_offset);
-	}
     }
 
   if (ipa_param_adjustments *padjs
@@ -1541,10 +1527,7 @@ cgraph_edge::redirect_call_stmt_to_callee (cgraph_edge *e)
 	remove_stmt_from_eh_lp (e->call_stmt);
 
       tree old_fntype = gimple_call_fntype (e->call_stmt);
-      new_stmt = padjs->modify_call (e->call_stmt,
-				     caller_info
-				     ? caller_info->performed_splits : NULL,
-				     e->callee->decl, false);
+      new_stmt = padjs->modify_call (e, false);
       cgraph_node *origin = e->callee;
       while (origin->clone_of)
 	origin = origin->clone_of;
@@ -1564,6 +1547,9 @@ cgraph_edge::redirect_call_stmt_to_callee (cgraph_edge *e)
     }
   else
     {
+      if (flag_checking
+	  && !fndecl_built_in_p (e->callee->decl, BUILT_IN_UNREACHABLE))
+	ipa_verify_edge_has_no_modifications (e);
       new_stmt = e->call_stmt;
       gimple_call_set_fndecl (new_stmt, e->callee->decl);
       update_stmt_fn (DECL_STRUCT_FUNCTION (e->caller->decl), new_stmt);
diff --git a/gcc/cgraphclones.c b/gcc/cgraphclones.c
index 9f86463b42d..7e463acab91 100644
--- a/gcc/cgraphclones.c
+++ b/gcc/cgraphclones.c
@@ -414,9 +414,6 @@ cgraph_node::create_clone (tree new_decl, profile_count prof_count,
   else if (info && info->param_adjustments)
     clone_info::get_create (new_node)->param_adjustments
 	 = info->param_adjustments;
-  if (info && info->performed_splits)
-    clone_info::get_create (new_node)->performed_splits
-	 = vec_safe_copy (info->performed_splits);
   new_node->split_part = split_part;
 
   FOR_EACH_VEC_ELT (redirect_callers, i, e)
diff --git a/gcc/ipa-param-manipulation.c b/gcc/ipa-param-manipulation.c
index f2d91476655..6a423391d2f 100644
--- a/gcc/ipa-param-manipulation.c
+++ b/gcc/ipa-param-manipulation.c
@@ -62,6 +62,80 @@ static const char *ipa_param_op_names[IPA_PARAM_PREFIX_COUNT]
      "IPA_PARAM_OP_NEW",
      "IPA_PARAM_OP_SPLIT"};
 
+/* Structure to hold declarations representing pass-through IPA-SRA splits.  In
+   essence, it tells new index for a combination of original index and
+   offset.  */
+
+struct pass_through_split_map
+{
+  /* Original argument index.  */
+  unsigned base_index;
+  /* Offset of the split part in the original argument.  */
+  unsigned unit_offset;
+  /* Index of the split part in the call statement - where clone
+     materialization put it.  */
+  int new_index;
+};
+
+/* Information about some call statements that needs to be conveyed from clone
+   materialization to edge redirection. */
+
+class ipa_edge_modification_info
+{
+ public:
+  ipa_edge_modification_info ()
+    {}
+
+  /* Mapping of original argument indices to where those arguments sit in the
+     call statement now or to a negative index if they were removed.  */
+  auto_vec<int> index_map;
+  /* Information about ISRA replacements put into the call statement at the
+     clone materialization stages.  */
+  auto_vec<pass_through_split_map> pass_through_map;
+  /* Necessary adjustment to ipa_param_adjustments::m_always_copy_start when
+     redirecting the call.  */
+  int always_copy_delta = 0;
+};
+
+/* Class for storing and retrieving summaries about cal statement
+   modifications.  */
+
+class ipa_edge_modification_sum
+  : public call_summary <ipa_edge_modification_info *>
+{
+ public:
+  ipa_edge_modification_sum (symbol_table *table)
+    : call_summary<ipa_edge_modification_info *> (table)
+  {
+  }
+
+  /* Hook that is called by summary when an edge is duplicated.  */
+
+  virtual void duplicate (cgraph_edge *,
+			  cgraph_edge *,
+			  ipa_edge_modification_info *old_info,
+			  ipa_edge_modification_info *new_info)
+  {
+    new_info->index_map.safe_splice (old_info->index_map);
+    new_info->pass_through_map.safe_splice (old_info->pass_through_map);
+    new_info->always_copy_delta = old_info->always_copy_delta;
+  }
+};
+
+/* Call summary to store information about edges which have had their arguments
+   partially modified already.  */
+
+static ipa_edge_modification_sum *ipa_edge_modifications;
+
+/* Fail compilation if CS has any summary associated with it in
+   ipa_edge_modifications.  */
+
+DEBUG_FUNCTION void
+ipa_verify_edge_has_no_modifications (cgraph_edge *cs)
+{
+  gcc_assert (!ipa_edge_modifications || !ipa_edge_modifications->get (cs));
+}
+
 /* Fill an empty vector ARGS with PARM_DECLs representing formal parameters of
    FNDECL.  The function should not be called during LTO WPA phase except for
    thunks (or functions with bodies streamed in). */
@@ -459,147 +533,46 @@ isra_get_ref_base_and_offset (tree expr, tree *base_p, unsigned *unit_offset_p)
   return true;
 }
 
-/* Return true if EXPR describes a transitive split (i.e. one that happened for
-   both the caller and the callee) as recorded in PERFORMED_SPLITS.  In that
-   case, store index of the respective record in PERFORMED_SPLITS into
-   *SM_IDX_P and the unit offset from all handled components in EXPR into
-   *UNIT_OFFSET_P.  */
-
-static bool
-transitive_split_p (vec<ipa_param_performed_split, va_gc> *performed_splits,
-		    tree expr, unsigned *sm_idx_p, unsigned *unit_offset_p)
-{
-  tree base;
-  if (!isra_get_ref_base_and_offset (expr, &base, unit_offset_p))
-    return false;
-
-  if (TREE_CODE (base) == SSA_NAME)
-    {
-      base = SSA_NAME_VAR (base);
-      if (!base)
-	return false;
-    }
-
-  unsigned len = vec_safe_length (performed_splits);
-  for (unsigned i = 0 ; i < len; i++)
-    {
-      ipa_param_performed_split *sm = &(*performed_splits)[i];
-      if (sm->dummy_decl == base)
-	{
-	  *sm_idx_p = i;
-	  return true;
-	}
-    }
-  return false;
-}
-
-/* Structure to hold declarations representing transitive IPA-SRA splits.  In
-   essence, if we need to pass UNIT_OFFSET of a parameter which originally has
-   number BASE_INDEX, we should pass down REPL.  */
-
-struct transitive_split_map
-{
-  tree repl;
-  unsigned base_index;
-  unsigned unit_offset;
-};
-
-/* If call STMT contains any parameters representing transitive splits as
-   described by PERFORMED_SPLITS, return the number of extra parameters that
-   were addded during clone materialization and fill in INDEX_MAP with adjusted
-   indices of corresponding original parameters and TRANS_MAP with description
-   of all transitive replacement descriptions.  Otherwise return zero. */
-
-static unsigned
-init_transitive_splits (vec<ipa_param_performed_split, va_gc> *performed_splits,
-			gcall *stmt, vec <unsigned> *index_map,
-			auto_vec <transitive_split_map> *trans_map)
-{
-  unsigned phony_arguments = 0;
-  unsigned stmt_idx = 0, base_index = 0;
-  unsigned nargs = gimple_call_num_args (stmt);
-  while (stmt_idx < nargs)
-    {
-      unsigned unit_offset_delta;
-      tree base_arg = gimple_call_arg (stmt, stmt_idx);
-
-      if (phony_arguments > 0)
-	index_map->safe_push (stmt_idx);
-
-      unsigned sm_idx;
-      stmt_idx++;
-      if (transitive_split_p (performed_splits, base_arg, &sm_idx,
-			      &unit_offset_delta))
-	{
-	  if (phony_arguments == 0)
-	    /* We have optimistically avoided constructing index_map do far but
-	       now it is clear it will be necessary, so let's create the easy
-	       bit we skipped until now.  */
-	    for (unsigned k = 0; k < stmt_idx; k++)
-	      index_map->safe_push (k);
-
-	  tree dummy = (*performed_splits)[sm_idx].dummy_decl;
-	  for (unsigned j = sm_idx; j < performed_splits->length (); j++)
-	    {
-	      ipa_param_performed_split *caller_split
-		= &(*performed_splits)[j];
-	      if (caller_split->dummy_decl != dummy)
-		break;
-
-	      tree arg = gimple_call_arg (stmt, stmt_idx);
-	      struct transitive_split_map tsm;
-	      tsm.repl = arg;
-	      tsm.base_index = base_index;
-	      if (caller_split->unit_offset >= unit_offset_delta)
-		{
-		  tsm.unit_offset
-		    = (caller_split->unit_offset - unit_offset_delta);
-		  trans_map->safe_push (tsm);
-		}
-
-	      phony_arguments++;
-	      stmt_idx++;
-	    }
-	}
-      base_index++;
-    }
-  return phony_arguments;
-}
-
-/* Modify actual arguments of a function call in statement STMT, assuming it
-   calls CALLEE_DECL.  CALLER_ADJ must be the description of parameter
-   adjustments of the caller or NULL if there are none.  Return the new
-   statement that replaced the old one.  When invoked, cfun and
-   current_function_decl have to be set to the caller.  */
+/* Modify actual arguments of a function call in statement currently belonging
+   to CS, and make it call CS->callee->decl.  Return the new statement that
+   replaced the old one.  When invoked, cfun and current_function_decl have to
+   be set to the caller.  */
 
 gcall *
-ipa_param_adjustments::modify_call (gcall *stmt,
-				    vec<ipa_param_performed_split,
-				        va_gc> *performed_splits,
-				    tree callee_decl, bool update_references)
+ipa_param_adjustments::modify_call (cgraph_edge *cs,
+				    bool update_references)
 {
+  gcall *stmt = cs->call_stmt;
+  tree callee_decl = cs->callee->decl;
+
+  ipa_edge_modification_info *mod_info
+    = ipa_edge_modifications ? ipa_edge_modifications->get (cs) : NULL;
+  if (mod_info && symtab->dump_file)
+    {
+      fprintf (symtab->dump_file, "Information about pre-exiting "
+	       "modifications.\n  Index map:");
+      unsigned idx_len = mod_info->index_map.length ();
+      for (unsigned i = 0; i < idx_len; i++)
+	fprintf (symtab->dump_file, " %i", mod_info->index_map[i]);
+      fprintf (symtab->dump_file, "\n  Pass-through split map: ");
+      unsigned ptm_len = mod_info->pass_through_map.length ();
+      for (unsigned i = 0; i < ptm_len; i++)
+	fprintf (symtab->dump_file,
+		 " (base_index: %u, offset: %u, new_index: %i)",
+		 mod_info->pass_through_map[i].base_index,
+		 mod_info->pass_through_map[i].unit_offset,
+		 mod_info->pass_through_map[i].new_index);
+      fprintf (symtab->dump_file, "\n  Always-copy delta: %i\n",
+	       mod_info->always_copy_delta);
+    }
+
   unsigned len = vec_safe_length (m_adj_params);
   auto_vec<tree, 16> vargs (len);
-  tree old_decl = gimple_call_fndecl (stmt);
   unsigned old_nargs = gimple_call_num_args (stmt);
+  unsigned orig_nargs = mod_info ? mod_info->index_map.length () : old_nargs;
   auto_vec<bool, 16> kept (old_nargs);
   kept.quick_grow_cleared (old_nargs);
 
-  auto_vec <unsigned, 16> index_map;
-  auto_vec <transitive_split_map> trans_map;
-  bool transitive_remapping = false;
-
-  if (performed_splits)
-    {
-      unsigned removed = init_transitive_splits (performed_splits,
-						 stmt, &index_map, &trans_map);
-      if (removed > 0)
-	{
-	  transitive_remapping = true;
-	  old_nargs -= removed;
-	}
-    }
-
   cgraph_node *current_node = cgraph_node::get (current_function_decl);
   if (update_references)
     current_node->remove_stmt_references (stmt);
@@ -612,13 +585,16 @@ ipa_param_adjustments::modify_call (gcall *stmt,
       ipa_adjusted_param *apm = &(*m_adj_params)[i];
       if (apm->op == IPA_PARAM_OP_COPY)
 	{
-	  unsigned index = apm->base_index;
-	  if (index >= old_nargs)
+	  int index = apm->base_index;
+	  if ((unsigned) index >= orig_nargs)
 	    /* Can happen if the original call has argument mismatch,
 	       ignore.  */
 	    continue;
-	  if (transitive_remapping)
-	    index = index_map[apm->base_index];
+	  if (mod_info)
+	    {
+	      index = mod_info->index_map[apm->base_index];
+	      gcc_assert (index >= 0);
+	    }
 
 	  tree arg = gimple_call_arg (stmt, index);
 
@@ -636,14 +612,17 @@ ipa_param_adjustments::modify_call (gcall *stmt,
 	 materialization.  */
       gcc_assert (apm->op == IPA_PARAM_OP_SPLIT);
 
-      /* We have to handle transitive changes differently using the maps we
-	 have created before.  So look into them first.  */
+      /* We have to handle pass-through changes differently using the map
+	 clone materialziation might have left behind.  */
       tree repl = NULL_TREE;
-      for (unsigned j = 0; j < trans_map.length (); j++)
-	if (trans_map[j].base_index == apm->base_index
-	    && trans_map[j].unit_offset == apm->unit_offset)
+      unsigned ptm_len = mod_info ? mod_info->pass_through_map.length () : 0;
+      for (unsigned j = 0; j < ptm_len; j++)
+	if (mod_info->pass_through_map[j].base_index == apm->base_index
+	    && mod_info->pass_through_map[j].unit_offset == apm->unit_offset)
 	  {
-	    repl = trans_map[j].repl;
+	    int repl_idx = mod_info->pass_through_map[j].new_index;
+	    gcc_assert (repl_idx >= 0);
+	    repl = gimple_call_arg (stmt, repl_idx);
 	    break;
 	  }
       if (repl)
@@ -652,12 +631,15 @@ ipa_param_adjustments::modify_call (gcall *stmt,
 	  continue;
 	}
 
-      unsigned index = apm->base_index;
-      if (index >= old_nargs)
+      int index = apm->base_index;
+      if ((unsigned) index >= orig_nargs)
 	/* Can happen if the original call has argument mismatch, ignore.  */
 	continue;
-      if (transitive_remapping)
-	index = index_map[apm->base_index];
+      if (mod_info)
+	{
+	  index = mod_info->index_map[apm->base_index];
+	  gcc_assert (index >= 0);
+	}
       tree base = gimple_call_arg (stmt, index);
 
       /* We create a new parameter out of the value of the old one, we can
@@ -773,8 +755,16 @@ ipa_param_adjustments::modify_call (gcall *stmt,
     }
 
   if (m_always_copy_start >= 0)
-    for (unsigned i = m_always_copy_start; i < old_nargs; i++)
-      vargs.safe_push (gimple_call_arg (stmt, i));
+    {
+      int always_copy_start = m_always_copy_start;
+      if (mod_info)
+	{
+	  always_copy_start += mod_info->always_copy_delta;
+	  gcc_assert (always_copy_start >= 0);
+	}
+      for (unsigned i = always_copy_start; i < old_nargs; i++)
+	vargs.safe_push (gimple_call_arg (stmt, i));
+    }
 
   /* For optimized away parameters, add on the caller side
      before the call
@@ -782,6 +772,7 @@ ipa_param_adjustments::modify_call (gcall *stmt,
      stmts and associate D#X with parm in decl_debug_args_lookup
      vector to say for debug info that if parameter parm had been passed,
      it would have value parm_Y(D).  */
+  tree old_decl = gimple_call_fndecl (stmt);
   if (MAY_HAVE_DEBUG_BIND_STMTS && old_decl && callee_decl)
     {
       vec<tree, va_gc> **debug_args = NULL;
@@ -799,13 +790,17 @@ ipa_param_adjustments::modify_call (gcall *stmt,
 	{
 	  if (!is_gimple_reg (old_parm) || kept[i])
 	    continue;
-	  tree origin = DECL_ORIGIN (old_parm);
 	  tree arg;
-	  if (transitive_remapping)
-	    arg = gimple_call_arg (stmt, index_map[i]);
+	  if (mod_info)
+	    {
+	      if (mod_info->index_map[i] < 0)
+		continue;
+	      arg = gimple_call_arg (stmt, mod_info->index_map[i]);
+	    }
 	  else
 	    arg = gimple_call_arg (stmt, i);
 
+	  tree origin = DECL_ORIGIN (old_parm);
 	  if (!useless_type_conversion_p (TREE_TYPE (origin), TREE_TYPE (arg)))
 	    {
 	      if (!fold_convertible_p (TREE_TYPE (origin), arg))
@@ -909,6 +904,9 @@ ipa_param_adjustments::modify_call (gcall *stmt,
 	gsi_prev (&gsi);
       }
     while (gsi_stmt (gsi) != gsi_stmt (prev_gsi));
+
+  if (mod_info)
+    ipa_edge_modifications->remove (cs);
   return new_stmt;
 }
 
@@ -931,13 +929,11 @@ ipa_param_adjustments::debug ()
   dump (stderr);
 }
 
-/* Register that REPLACEMENT should replace parameter described in APM and
-   optionally as DUMMY to mark transitive splits across calls.  */
+/* Register that REPLACEMENT should replace parameter described in APM.  */
 
 void
 ipa_param_body_adjustments::register_replacement (ipa_adjusted_param *apm,
-						  tree replacement,
-						  tree dummy)
+						  tree replacement)
 {
   gcc_checking_assert (apm->op == IPA_PARAM_OP_SPLIT
 		       || apm->op == IPA_PARAM_OP_NEW);
@@ -945,7 +941,7 @@ ipa_param_body_adjustments::register_replacement (ipa_adjusted_param *apm,
   ipa_param_body_replacement psr;
   psr.base = m_oparms[apm->prev_clone_index];
   psr.repl = replacement;
-  psr.dummy = dummy;
+  psr.dummy = NULL_TREE;
   psr.unit_offset = apm->unit_offset;
   m_replacements.safe_push (psr);
 }
@@ -1007,9 +1003,6 @@ ipa_param_body_adjustments::common_initialization (tree old_fndecl,
   auto_vec<bool, 16> kept;
   kept.reserve_exact (m_oparms.length ());
   kept.quick_grow_cleared (m_oparms.length ());
-  auto_vec<tree, 16> isra_dummy_decls;
-  isra_dummy_decls.reserve_exact (m_oparms.length ());
-  isra_dummy_decls.quick_grow_cleared (m_oparms.length ());
 
   unsigned adj_len = vec_safe_length (m_adj_params);
   m_method2func = ((TREE_CODE (TREE_TYPE (m_fndecl)) == METHOD_TYPE)
@@ -1055,35 +1048,7 @@ ipa_param_body_adjustments::common_initialization (tree old_fndecl,
 	  if (apm->op == IPA_PARAM_OP_SPLIT)
 	    {
 	      m_split_modifications_p = true;
-
-	      if (m_id)
-		{
-		  tree dummy_decl;
-		  if (!isra_dummy_decls[prev_index])
-		    {
-		      dummy_decl = copy_decl_to_var (m_oparms[prev_index],
-						     m_id);
-		      /* Any attempt to remap this dummy in this particular
-			 instance of clone materialization should yield
-			 itself.  */
-		      insert_decl_map (m_id, dummy_decl, dummy_decl);
-
-		      DECL_CHAIN (dummy_decl) = *vars;
-		      *vars = dummy_decl;
-		      isra_dummy_decls[prev_index] = dummy_decl;
-		    }
-		  else
-		    dummy_decl = isra_dummy_decls[prev_index];
-
-		  register_replacement (apm, new_parm, dummy_decl);
-		  ipa_param_performed_split ps;
-		  ps.dummy_decl = dummy_decl;
-		  ps.unit_offset = apm->unit_offset;
-		  vec_safe_push (clone_info::get_create
-				   (m_id->dst_node)->performed_splits, ps);
-		}
-	      else
-		register_replacement (apm, new_parm);
+	      register_replacement (apm, new_parm);
 	    }
         }
       else
@@ -1110,8 +1075,6 @@ ipa_param_body_adjustments::common_initialization (tree old_fndecl,
 	  {
 	    if (!m_id->decl_map->get (m_oparms[i]))
 	      {
-		/* TODO: Perhaps at least aggregate-type params could re-use
-		   their isra_dummy_decl here?  */
 		tree var = copy_decl_to_var (m_oparms[i], m_id);
 		insert_decl_map (m_id, m_oparms[i], var);
 		/* Declare this new variable.  */
@@ -1502,220 +1465,329 @@ ipa_param_body_adjustments::modify_assignment (gimple *stmt,
   return any;
 }
 
-/* Data passed to remap_split_decl_to_dummy through walk_tree.  */
+/* Record information about what modifications to call arguments have already
+   been done by clone materialization into a summary describing CS.  The
+   information is stored in NEW_INDEX_MAP, NEW_PT_MAP and NEW_ALWAYS_COPY_DELTA
+   and correspond to equivalent fields in ipa_edge_modification_info.  Return
+   the edge summary.  */
+
+static ipa_edge_modification_info *
+record_argument_state_1 (cgraph_edge *cs, const vec<int> &new_index_map,
+			 const vec<pass_through_split_map> &new_pt_map,
+			 int new_always_copy_delta)
 
-struct simple_tree_swap_info
 {
-  /* Change FROM to TO.  */
-  tree from, to;
-  /* And set DONE to true when doing so.  */
-  bool done;
-};
+  ipa_edge_modification_info *sum = ipa_edge_modifications->get_create (cs);
 
-/* Simple remapper to remap a split parameter to the same expression based on a
-   special dummy decl so that edge redirections can detect transitive splitting
-   and finish them.  */
-
-static tree
-remap_split_decl_to_dummy (tree *tp, int *walk_subtrees, void *data)
-{
-  tree t = *tp;
-
-  if (DECL_P (t) || TREE_CODE (t) == SSA_NAME)
+  unsigned len = sum->pass_through_map.length ();
+  for (unsigned i = 0; i < len; i++)
     {
-      struct simple_tree_swap_info *swapinfo
-	= (struct simple_tree_swap_info *) data;
-      if (t == swapinfo->from
-	  || (TREE_CODE (t) == SSA_NAME
-	      && SSA_NAME_VAR (t) == swapinfo->from))
-	{
-	  *tp = swapinfo->to;
-	  swapinfo->done = true;
-	}
-      *walk_subtrees = 0;
+      unsigned oldnew = sum->pass_through_map[i].new_index;
+      sum->pass_through_map[i].new_index = new_index_map[oldnew];
+    }
+
+  len = sum->index_map.length ();
+  if (len > 0)
+    {
+      unsigned nptlen = new_pt_map.length ();
+      for (unsigned j = 0; j < nptlen; j++)
+	{
+	  int inverse = -1;
+	  for (unsigned i = 0; i < len ; i++)
+	    if ((unsigned) sum->index_map[i] == new_pt_map[j].base_index)
+	    {
+	      inverse = i;
+	      break;
+	    }
+	  gcc_assert (inverse >= 0);
+	  pass_through_split_map ptm_item;
+
+	  ptm_item.base_index = inverse;
+	  ptm_item.unit_offset = new_pt_map[j].unit_offset;
+	  ptm_item.new_index = new_pt_map[j].new_index;
+	  sum->pass_through_map.safe_push (ptm_item);
+	}
+
+      for (unsigned i = 0; i < len; i++)
+	{
+	  int idx = sum->index_map[i];
+	  if (idx < 0)
+	    continue;
+	  sum->index_map[i] = new_index_map[idx];
+	}
     }
-  else if (TYPE_P (t))
-      *walk_subtrees = 0;
   else
-    *walk_subtrees = 1;
-  return NULL_TREE;
+    {
+      sum->pass_through_map.safe_splice (new_pt_map);
+      sum->index_map.safe_splice (new_index_map);
+    }
+  sum->always_copy_delta += new_always_copy_delta;
+  return sum;
 }
 
+/* Record information about what modifications to call arguments have already
+   been done by clone materialization into a summary of an edge describing the
+   call in this clone and all its clones.  NEW_INDEX_MAP, NEW_PT_MAP and
+   NEW_ALWAYS_COPY_DELTA have the same meaning as record_argument_state_1.
+
+   In order to associate the info with the right edge summaries, we need
+   address of the ORIG_STMT in the function from which we are cloning (because
+   the edges have not yet been re-assigned to the new statement that has just
+   been created) and ID, the structure governing function body copying.  */
+
+static void
+record_argument_state (copy_body_data *id, gimple *orig_stmt,
+		       const vec<int> &new_index_map,
+		       const vec<pass_through_split_map> &new_pt_map,
+		       int new_always_copy_delta)
+{
+  if (!ipa_edge_modifications)
+    ipa_edge_modifications = new ipa_edge_modification_sum (symtab);
+
+  struct cgraph_node *this_node = id->dst_node;
+  ipa_edge_modification_info *first_sum = NULL;
+  cgraph_edge *cs = this_node->get_edge (orig_stmt);
+  if (cs)
+    first_sum = record_argument_state_1 (cs, new_index_map, new_pt_map,
+					 new_always_copy_delta);
+  else
+    gcc_assert (this_node->clones);
+
+  if (!this_node->clones)
+    return;
+  for (cgraph_node *subclone = this_node->clones; subclone != this_node;)
+    {
+      cs = subclone->get_edge (orig_stmt);
+      if (cs)
+	{
+	  if (!first_sum)
+	    first_sum = record_argument_state_1 (cs, new_index_map, new_pt_map,
+						 new_always_copy_delta);
+	  else
+	    {
+	      ipa_edge_modification_info *s2
+		= ipa_edge_modifications->get_create (cs);
+	      s2->index_map.truncate (0);
+	      s2->index_map.safe_splice (first_sum->index_map);
+	      s2->pass_through_map.truncate (0);
+	      s2->pass_through_map.safe_splice (first_sum->pass_through_map);
+	      s2->always_copy_delta = first_sum->always_copy_delta;
+	    }
+	}
+      else
+	gcc_assert (subclone->clones);
+
+      if (subclone->clones)
+	subclone = subclone->clones;
+      else if (subclone->next_sibling_clone)
+	subclone = subclone->next_sibling_clone;
+      else
+	{
+	  while (subclone != this_node && !subclone->next_sibling_clone)
+	    subclone = subclone->clone_of;
+	  if (subclone != this_node)
+	    subclone = subclone->next_sibling_clone;
+	}
+    }
+}
 
 /* If the call statement pointed at by STMT_P contains any expressions that
    need to replaced with a different one as noted by ADJUSTMENTS, do so.  f the
    statement needs to be rebuilt, do so.  Return true if any modifications have
-   been performed.
+   been performed.  ORIG_STMT, if not NULL, is the original statement in the
+   function that is being cloned from, which at this point can be used to look
+   up call_graph edges.
 
    If the method is invoked as a part of IPA clone materialization and if any
-   parameter split is transitive, i.e. it applies to the functin that is being
-   modified and also to the callee of the statement, replace the parameter
-   passed to old callee with an equivalent expression based on a dummy decl
-   followed by PARM_DECLs representing the actual replacements.  The actual
-   replacements will be then converted into SSA_NAMEs and then
-   ipa_param_adjustments::modify_call will find the appropriate ones and leave
-   only those in the call.  */
+   parameter split is pass-through, i.e. it applies to the functin that is
+   being modified and also to the callee of the statement, replace the
+   parameter passed to old callee with all of the replacement a callee might
+   possibly want and record the performed argument modifications in
+   ipa_edge_modifications.  Likewise if any argument has already been left out
+   because it is not necessary.  */
 
 bool
-ipa_param_body_adjustments::modify_call_stmt (gcall **stmt_p)
+ipa_param_body_adjustments::modify_call_stmt (gcall **stmt_p,
+					      gimple *orig_stmt)
 {
-  gcall *stmt = *stmt_p;
   auto_vec <unsigned, 4> pass_through_args;
   auto_vec <unsigned, 4> pass_through_pbr_indices;
+  auto_vec <HOST_WIDE_INT, 4> pass_through_offsets;
+  gcall *stmt = *stmt_p;
+  unsigned nargs = gimple_call_num_args (stmt);
+  bool recreate = false;
 
-  if (m_split_modifications_p && m_id)
+  for (unsigned i = 0; i < gimple_call_num_args (stmt); i++)
     {
-      for (unsigned i = 0; i < gimple_call_num_args (stmt); i++)
+      tree t = gimple_call_arg (stmt, i);
+      gcc_assert (TREE_CODE (t) != BIT_FIELD_REF
+		  && TREE_CODE (t) != IMAGPART_EXPR
+		  && TREE_CODE (t) != REALPART_EXPR);
+
+      /* The follow-up patch will check whether t needs to be removed, that's
+	 why this condition is in the loop.  */
+
+      if (!m_split_modifications_p)
+	continue;
+
+      tree base;
+      unsigned agg_arg_offset;
+      if (!isra_get_ref_base_and_offset (t, &base, &agg_arg_offset))
+	continue;
+
+      bool by_ref = false;
+      if (TREE_CODE (base) == SSA_NAME)
 	{
-	  tree t = gimple_call_arg (stmt, i);
-	  gcc_assert (TREE_CODE (t) != BIT_FIELD_REF
-		      && TREE_CODE (t) != IMAGPART_EXPR
-		      && TREE_CODE (t) != REALPART_EXPR);
-
-	  tree base;
-	  unsigned unit_offset;
-	  if (!isra_get_ref_base_and_offset (t, &base, &unit_offset))
+	  if (!SSA_NAME_IS_DEFAULT_DEF (base))
 	    continue;
+	  base = SSA_NAME_VAR (base);
+	  gcc_checking_assert (base);
+	  by_ref = true;
+	}
+      if (TREE_CODE (base) != PARM_DECL)
+	continue;
 
-	  bool by_ref = false;
-	  if (TREE_CODE (base) == SSA_NAME)
+      bool base_among_replacements = false;
+      unsigned j, repl_list_len = m_replacements.length ();
+      for (j = 0; j < repl_list_len; j++)
+	{
+	  ipa_param_body_replacement *pbr = &m_replacements[j];
+	  if (pbr->base == base)
 	    {
-	      if (!SSA_NAME_IS_DEFAULT_DEF (base))
-		continue;
-	      base = SSA_NAME_VAR (base);
-	      gcc_checking_assert (base);
-	      by_ref = true;
+	      base_among_replacements = true;
+	      break;
 	    }
-	  if (TREE_CODE (base) != PARM_DECL)
-	    continue;
+	}
+      if (!base_among_replacements)
+	continue;
 
-	  bool base_among_replacements = false;
-	  unsigned j, repl_list_len = m_replacements.length ();
-	  for (j = 0; j < repl_list_len; j++)
+      /* We still have to distinguish between an end-use that we have to
+	 transform now and a pass-through, which happens in the following
+	 two cases.  */
+
+      /* TODO: After we adjust ptr_parm_has_nonarg_uses to also consider
+	 &MEM_REF[ssa_name + offset], we will also have to detect that case
+	 here.    */
+
+      if (TREE_CODE (t) == SSA_NAME
+	  && SSA_NAME_IS_DEFAULT_DEF (t)
+	  && SSA_NAME_VAR (t)
+	  && TREE_CODE (SSA_NAME_VAR (t)) == PARM_DECL)
+	{
+	  /* This must be a by_reference pass-through.  */
+	  recreate = true;
+	  gcc_assert (POINTER_TYPE_P (TREE_TYPE (t)));
+	  pass_through_args.safe_push (i);
+	  pass_through_pbr_indices.safe_push (j);
+	  pass_through_offsets.safe_push (agg_arg_offset);
+	}
+      else if (!by_ref && AGGREGATE_TYPE_P (TREE_TYPE (t)))
+	{
+	  /* Currently IPA-SRA guarantees the aggregate access type
+	     exactly matches in this case.  So if it does not match, it is
+	     a pass-through argument that will be sorted out at edge
+	     redirection time.  */
+	  ipa_param_body_replacement *pbr
+	    = lookup_replacement_1 (base, agg_arg_offset);
+
+	  if (!pbr
+	      || (TYPE_MAIN_VARIANT (TREE_TYPE (t))
+		  != TYPE_MAIN_VARIANT (TREE_TYPE (pbr->repl))))
 	    {
-	      ipa_param_body_replacement *pbr = &m_replacements[j];
-	      if (pbr->base == base)
-		{
-		  base_among_replacements = true;
-		  break;
-		}
-	    }
-	  if (!base_among_replacements)
-	    continue;
-
-	  /* We still have to distinguish between an end-use that we have to
-	     transform now and a pass-through, which happens in the following
-	     two cases.  */
-
-	  /* TODO: After we adjust ptr_parm_has_nonarg_uses to also consider
-	     &MEM_REF[ssa_name + offset], we will also have to detect that case
-	     here.    */
-
-	  if (TREE_CODE (t) == SSA_NAME
-	      && SSA_NAME_IS_DEFAULT_DEF (t)
-	      && SSA_NAME_VAR (t)
-	      && TREE_CODE (SSA_NAME_VAR (t)) == PARM_DECL)
-	    {
-	      /* This must be a by_reference pass-through.  */
-	      gcc_assert (POINTER_TYPE_P (TREE_TYPE (t)));
+	      recreate = true;
 	      pass_through_args.safe_push (i);
 	      pass_through_pbr_indices.safe_push (j);
-	    }
-	  else if (!by_ref && AGGREGATE_TYPE_P (TREE_TYPE (t)))
-	    {
-	      /* Currently IPA-SRA guarantees the aggregate access type
-		 exactly matches in this case.  So if it does not match, it is
-		 a pass-through argument that will be sorted out at edge
-		 redirection time.  */
-	      ipa_param_body_replacement *pbr
-		= lookup_replacement_1 (base, unit_offset);
-
-	      if (!pbr
-		  || (TYPE_MAIN_VARIANT (TREE_TYPE (t))
-		      != TYPE_MAIN_VARIANT (TREE_TYPE (pbr->repl))))
-		{
-		  pass_through_args.safe_push (i);
-		  pass_through_pbr_indices.safe_push (j);
-		}
+	      pass_through_offsets.safe_push (agg_arg_offset);
 	    }
 	}
     }
 
-  unsigned nargs = gimple_call_num_args (stmt);
-  if (!pass_through_args.is_empty ())
+  if (!recreate)
     {
-      auto_vec<tree, 16> vargs;
-      unsigned pt_idx = 0;
+      /* No need to rebuild the statement, let's just modify arguments
+	 and the LHS if/as appropriate.  */
+      bool modified = false;
       for (unsigned i = 0; i < nargs; i++)
 	{
-	  if (pt_idx < pass_through_args.length ()
-	      && i == pass_through_args[pt_idx])
-	    {
-	      unsigned j = pass_through_pbr_indices[pt_idx];
-	      pt_idx++;
-	      tree base = m_replacements[j].base;
-
-	      /* Map base will get mapped to the special transitive-isra marker
-		 dummy decl. */
-	      struct simple_tree_swap_info swapinfo;
-	      swapinfo.from = base;
-	      swapinfo.to = m_replacements[j].dummy;
-	      swapinfo.done = false;
-	      tree arg = gimple_call_arg (stmt, i);
-	      walk_tree (&arg, remap_split_decl_to_dummy, &swapinfo, NULL);
-	      gcc_assert (swapinfo.done);
-	      vargs.safe_push (arg);
-	      /* Now let's push all replacements pertaining to this parameter
-		 so that all gimple register ones get correct SSA_NAMES.  Edge
-		 redirection will weed out the dummy argument as well as all
-		 unused replacements later.  */
-	      unsigned int repl_list_len = m_replacements.length ();
-	      for (; j < repl_list_len; j++)
-		{
-		  if (m_replacements[j].base != base)
-		    break;
-		  vargs.safe_push (m_replacements[j].repl);
-		}
-	    }
-	  else
-	    {
-	      tree t = gimple_call_arg (stmt, i);
-	      modify_expression (&t, true);
-	      vargs.safe_push (t);
-	    }
+	  tree *t = gimple_call_arg_ptr (stmt, i);
+	  modified |= modify_expression (t, true);
 	}
-      gcall *new_stmt = gimple_build_call_vec (gimple_call_fn (stmt), vargs);
-      if (gimple_has_location (stmt))
-	gimple_set_location (new_stmt, gimple_location (stmt));
-      gimple_call_set_chain (new_stmt, gimple_call_chain (stmt));
-      gimple_call_copy_flags (new_stmt, stmt);
-      if (tree lhs = gimple_call_lhs (stmt))
+      if (gimple_call_lhs (stmt))
 	{
-	  modify_expression (&lhs, false);
-	  /* Avoid adjusting SSA_NAME_DEF_STMT of a SSA lhs, SSA names
-	     have not yet been remapped.  */
-	  *gimple_call_lhs_ptr (new_stmt) = lhs;
+	  tree *t = gimple_call_lhs_ptr (stmt);
+	  modified |= modify_expression (t, false);
 	}
-      *stmt_p = new_stmt;
-      return true;
+      return modified;
     }
 
-  /* Otherwise, no need to rebuild the statement, let's just modify arguments
-     and the LHS if/as appropriate.  */
-  bool modified = false;
+  auto_vec<int, 16> index_map;
+  auto_vec<pass_through_split_map, 4> pass_through_map;
+  auto_vec<tree, 16> vargs;
+  int always_copy_delta = 0;
+  unsigned pt_idx = 0;
+  int new_arg_idx = 0;
   for (unsigned i = 0; i < nargs; i++)
     {
-      tree *t = gimple_call_arg_ptr (stmt, i);
-      modified |= modify_expression (t, true);
+      if (pt_idx < pass_through_args.length ()
+	  && i == pass_through_args[pt_idx])
+	{
+	  unsigned j = pass_through_pbr_indices[pt_idx];
+	  unsigned agg_arg_offset = pass_through_offsets[pt_idx];
+	  pt_idx++;
+	  always_copy_delta--;
+	  tree base = m_replacements[j].base;
+
+	  /* In order to be put into SSA form, we have to push all replacements
+	     pertaining to this parameter as parameters to the call statement.
+	     Edge redirection will need to use edge summary to weed out the
+	     unnecessary ones.  */
+	  unsigned repl_list_len = m_replacements.length ();
+	  for (; j < repl_list_len; j++)
+	    {
+	      if (m_replacements[j].base != base)
+		break;
+	      if (m_replacements[j].unit_offset < agg_arg_offset)
+		continue;
+	      pass_through_split_map pt_map;
+	      pt_map.base_index = i;
+	      pt_map.unit_offset
+		= m_replacements[j].unit_offset - agg_arg_offset;
+	      pt_map.new_index = new_arg_idx;
+	      pass_through_map.safe_push (pt_map);
+	      vargs.safe_push (m_replacements[j].repl);
+	      new_arg_idx++;
+	      always_copy_delta++;
+	    }
+	  index_map.safe_push (-1);
+	}
+      else
+	{
+	  tree t = gimple_call_arg (stmt, i);
+	  modify_expression (&t, true);
+	  vargs.safe_push (t);
+	  index_map.safe_push (new_arg_idx);
+	  new_arg_idx++;
+	}
     }
 
-  if (gimple_call_lhs (stmt))
+  gcall *new_stmt = gimple_build_call_vec (gimple_call_fn (stmt), vargs);
+  if (gimple_has_location (stmt))
+    gimple_set_location (new_stmt, gimple_location (stmt));
+  gimple_call_set_chain (new_stmt, gimple_call_chain (stmt));
+  gimple_call_copy_flags (new_stmt, stmt);
+  if (tree lhs = gimple_call_lhs (stmt))
     {
-      tree *t = gimple_call_lhs_ptr (stmt);
-      modified |= modify_expression (t, false);
+      modify_expression (&lhs, false);
+      /* Avoid adjusting SSA_NAME_DEF_STMT of a SSA lhs, SSA names
+	 have not yet been remapped.  */
+      *gimple_call_lhs_ptr (new_stmt) = lhs;
     }
+  *stmt_p = new_stmt;
 
-  return modified;
+  if (orig_stmt)
+    record_argument_state (m_id, orig_stmt, index_map, pass_through_map,
+			   always_copy_delta);
+  return true;
 }
 
 /* If the statement STMT contains any expressions that need to replaced with a
@@ -1726,7 +1798,8 @@ ipa_param_body_adjustments::modify_call_stmt (gcall **stmt_p)
 
 bool
 ipa_param_body_adjustments::modify_gimple_stmt (gimple **stmt,
-						gimple_seq *extra_stmts)
+						gimple_seq *extra_stmts,
+						gimple *orig_stmt)
 {
   bool modified = false;
   tree *t;
@@ -1746,7 +1819,7 @@ ipa_param_body_adjustments::modify_gimple_stmt (gimple **stmt,
       break;
 
     case GIMPLE_CALL:
-      modified |= modify_call_stmt ((gcall **) stmt);
+      modified |= modify_call_stmt ((gcall **) stmt, orig_stmt);
       break;
 
     case GIMPLE_ASM:
@@ -1803,7 +1876,7 @@ ipa_param_body_adjustments::modify_cfun_body ()
 	  gimple *stmt = gsi_stmt (gsi);
 	  gimple *stmt_copy = stmt;
 	  gimple_seq extra_stmts = NULL;
-	  bool modified = modify_gimple_stmt (&stmt, &extra_stmts);
+	  bool modified = modify_gimple_stmt (&stmt, &extra_stmts, NULL);
 	  if (stmt != stmt_copy)
 	    {
 	      gcc_checking_assert (modified);
@@ -1952,3 +2025,17 @@ ipa_param_body_adjustments::perform_cfun_body_modifications ()
   return cfg_changed;
 }
 
+
+/* Deallocate summaries which otherwise stay alive until the end of
+   compilation.  */
+
+void
+ipa_edge_modifications_finalize ()
+{
+  if (!ipa_edge_modifications)
+    return;
+  delete ipa_edge_modifications;
+  ipa_edge_modifications = NULL;
+}
+
+
diff --git a/gcc/ipa-param-manipulation.h b/gcc/ipa-param-manipulation.h
index c80e1bc5d6b..31dcc4b9768 100644
--- a/gcc/ipa-param-manipulation.h
+++ b/gcc/ipa-param-manipulation.h
@@ -54,7 +54,7 @@ or only a vector of ipa_adjusted_params.
 When these classes are used in the context of call graph clone materialization
 and subsequent call statement redirection - which is the point at which we
 modify arguments in call statements - they need to cooperate with each other in
-order to handle what we refer to as transitive (IPA-SRA) splits.  These are
+order to handle what we refer to as pass-through (IPA-SRA) splits.  These are
 situations when a formal parameter of one function is split into several
 smaller ones and some of them are then passed on in a call to another function
 because the formal parameter of this callee has also been split.
@@ -83,7 +83,7 @@ baz ()
 Both bar and foo would have their parameter split.  Foo would receive one
 replacement representing s.b.  Function bar would see its parameter split into
 one replacement representing z.s.a and another representing z.s.b which would
-be passed on to foo.  It would be a so called transitive split IPA-SRA
+be passed on to foo.  It would be a so called pass-through split IPA-SRA
 replacement, one which is passed in a call as an actual argument to another
 IPA-SRA replacement in another function.
 
@@ -95,30 +95,25 @@ all of the above.
 
 Call redirection has to be able to find the right decl or SSA_NAME that
 corresponds to the transitive split in the caller.  The SSA names are assigned
-right after clone materialization/ modification and cannot be "added"
-afterwards.  Moreover, if the caller has been inlined the SSA_NAMEs in question
-no longer belong to PARM_DECLs but to VAR_DECLs, indistinguishable from any
-others.
+right after clone materialization/ modification and cannot be "added" to call
+arguments at any later point.  Moreover, if the caller has been inlined the
+SSA_NAMEs in question no longer belong to PARM_DECLs but to VAR_DECLs,
+indistinguishable from any others.
 
 Therefore, when clone materialization finds a call statement which it knows is
-a part of a transitive split, it will modify it into:
+a part of a transitive split, it will simply add as arguments all new "split"
+replacements (that have grater or equal offset than the original call
+argument):
 
-  foo (DUMMY_Z_VAR.s, repl_for_a, repl_for_b, <rest of original arguments>);
+  foo (repl_for_a, repl_for_b, <rest of original arguments>);
 
-It will also store {DUMMY_S_VAR, 32} and {DUMMY_S_VAR, 64} representing offsets
-of z.s.a and z.s.b (assuming a 32-bit int) into foo's cgraph node
-clone->performed_splits vector (which is storing structures of type
-ipa_param_performed_split also defined in this header file).
-
-Call redirection will identify that expression DUMMY_Z_VAR.s is based on a
-variable stored in performed_splits vector and learn that the following
-arguments, already in SSA form, represent offsets 32 and 64 in a split original
-parameter.  It subtracts offset of DUMMY_Z_VAR.s from 32 and 64 and arrives at
-offsets 0 and 32 within callee's original parameter.  At this point it also
-knows from the call graph that only the bit with offset 32 is needed and so
-changes the call statement into final:
-
-bar (repl_for_b, <rest of original arguments>);  */
+It will also store into ipa_edge_modification_info (which is internal to
+ipa-param-modification.c) information about which replacement is which and
+where original arguments are.  Call redirection will then invoke
+ipa_param_adjustments::modify_call which will access this information and
+eliminate all replacements which the callee does not expect (repl_for_a in our
+example above).  In between these two steps, however, a call statement might
+have extraneous arguments.  */
 
 #ifndef IPA_PARAM_MANIPULATION_H
 #define IPA_PARAM_MANIPULATION_H
@@ -207,21 +202,6 @@ struct GTY(()) ipa_adjusted_param
 void ipa_dump_adjusted_parameters (FILE *f,
 				   vec<ipa_adjusted_param, va_gc> *adj_params);
 
-/* Structure to remember the split performed on a node so that edge redirection
-   (i.e. splitting arguments of call statements) know how split formal
-   parameters of the caller are represented.  */
-
-struct GTY(()) ipa_param_performed_split
-{
-  /* The dummy VAR_DECL that was created instead of the split parameter that
-     sits in the call in the meantime between clone materialization and call
-     redirection.  All entries in a vector of performed splits that correspond
-     to the same dumy decl must be grouped together.  */
-  tree dummy_decl;
-  /* Offset into the original parameter.  */
-  unsigned unit_offset;
-};
-
 /* Class used to record planned modifications to parameters of a function and
    also to perform necessary modifications at the caller side at the gimple
    level.  Used to describe all cgraph node clones that have their parameters
@@ -244,9 +224,7 @@ public:
 
   /* Modify a call statement arguments (and possibly remove the return value)
      as described in the data fields of this class.  */
-  gcall *modify_call (gcall *stmt,
-		      vec<ipa_param_performed_split, va_gc> *performed_splits,
-		      tree callee_decl, bool update_references);
+  gcall *modify_call (cgraph_edge *cs, bool update_references);
   /* Return if the first parameter is left intact.  */
   bool first_param_intact_p ();
   /* Build a function type corresponding to the modified call.  */
@@ -293,15 +271,9 @@ struct ipa_param_body_replacement
   tree base;
   /* The new decl it should be replaced with.  */
   tree repl;
-  /* When modifying clones during IPA clone materialization, this is a dummy
-     decl used to mark calls in which we need to apply transitive splitting,
-     these dummy delcls are inserted as arguments to such calls and then
-     followed by all the replacements with offset info stored in
-     ipa_param_performed_split.
-
-     Users of ipa_param_body_adjustments that modify standalone functions
-     outside of IPA clone materialization can use this field for their internal
-     purposes.  */
+  /* Users of ipa_param_body_adjustments that modify standalone functions
+     outside of IPA clone materialization can use the following field for their
+     internal purposes.  */
   tree dummy;
   /* The offset within BASE that REPL represents.  */
   unsigned unit_offset;
@@ -342,8 +314,7 @@ public:
   /* Change the PARM_DECLs.  */
   void modify_formal_parameters ();
   /* Register a replacement decl for the transformation done in APM.  */
-  void register_replacement (ipa_adjusted_param *apm, tree replacement,
-			     tree dummy = NULL_TREE);
+  void register_replacement (ipa_adjusted_param *apm, tree replacement);
   /* Lookup a replacement for a given offset within a given parameter.  */
   tree lookup_replacement (tree base, unsigned unit_offset);
   /* Lookup a replacement for an expression, if there is one.  */
@@ -353,7 +324,8 @@ public:
      parameter. */
   tree get_replacement_ssa_base (tree old_decl);
   /* Modify a statement.  */
-  bool modify_gimple_stmt (gimple **stmt, gimple_seq *extra_stmts);
+  bool modify_gimple_stmt (gimple **stmt, gimple_seq *extra_stmts,
+			   gimple *orig_stmt);
   /* Return the new chain of parameters.  */
   tree get_new_param_chain ();
 
@@ -380,9 +352,10 @@ private:
   tree replace_removed_params_ssa_names (tree old_name, gimple *stmt);
   bool modify_expression (tree *expr_p, bool convert);
   bool modify_assignment (gimple *stmt, gimple_seq *extra_stmts);
-  bool modify_call_stmt (gcall **stmt_p);
+  bool modify_call_stmt (gcall **stmt_p, gimple *orig_stmt);
   bool modify_cfun_body ();
   void reset_debug_stmts ();
+  void mark_dead_statements (tree dead_param);
 
   /* Declaration of the function that is being transformed.  */
 
@@ -431,5 +404,8 @@ private:
 
 void push_function_arg_decls (vec<tree> *args, tree fndecl);
 void push_function_arg_types (vec<tree> *types, tree fntype);
+void ipa_verify_edge_has_no_modifications (cgraph_edge *cs);
+void ipa_edge_modifications_finalize ();
+
 
 #endif	/* IPA_PARAM_MANIPULATION_H */
diff --git a/gcc/symtab-clones.h b/gcc/symtab-clones.h
index 5695a434f6a..a6ad4a6e27f 100644
--- a/gcc/symtab-clones.h
+++ b/gcc/symtab-clones.h
@@ -26,8 +26,7 @@ struct GTY(()) clone_info
   /* Constructor.  */
   clone_info ()
     : tree_map (NULL),
-      param_adjustments (NULL),
-      performed_splits (NULL)
+      param_adjustments (NULL)
   {
   }
   /* Constants discovered by IPA-CP, i.e. which parameter should be replaced
@@ -35,18 +34,6 @@ struct GTY(()) clone_info
   vec<ipa_replace_map *, va_gc> *tree_map;
   /* Parameter modification that IPA-SRA decided to perform.  */
   ipa_param_adjustments *param_adjustments;
-  /* Lists of dummy-decl and offset pairs representing split formal parameters
-     in the caller.  Offsets of all new replacements are enumerated, those
-     coming from the same original parameter have the same dummy decl stored
-     along with them.
-
-     Dummy decls sit in call statement arguments followed by new parameter
-     decls (or their SSA names) in between (caller) clone materialization and
-     call redirection.  Redirection then recognizes the dummy variable and
-     together with the stored offsets can reconstruct what exactly the new
-     parameter decls represent and can leave in place only those that the
-     callee expects.  */
-  vec<ipa_param_performed_split, va_gc> *performed_splits;
 
   /* Return clone_info, if available.  */
   static clone_info *get (cgraph_node *node);
diff --git a/gcc/toplev.c b/gcc/toplev.c
index 7e2325337ea..01caea31fda 100644
--- a/gcc/toplev.c
+++ b/gcc/toplev.c
@@ -86,6 +86,7 @@ along with GCC; see the file COPYING3.  If not see
 #include "optinfo-emit-json.h"
 #include "ipa-modref-tree.h"
 #include "ipa-modref.h"
+#include "ipa-param-manipulation.h"
 #include "dbgcnt.h"
 
 #if defined(DBX_DEBUGGING_INFO) || defined(XCOFF_DEBUGGING_INFO)
@@ -2385,6 +2386,7 @@ toplev::finalize (void)
   ipa_reference_c_finalize ();
   ipa_fnsummary_c_finalize ();
   ipa_modref_c_finalize ();
+  ipa_edge_modifications_finalize ();
 
   cgraph_c_finalize ();
   cgraphunit_c_finalize ();
diff --git a/gcc/tree-inline.c b/gcc/tree-inline.c
index 8f945b88c12..e2fb6be681c 100644
--- a/gcc/tree-inline.c
+++ b/gcc/tree-inline.c
@@ -1900,7 +1900,7 @@ remap_gimple_stmt (gimple *stmt, copy_body_data *id)
   if (id->param_body_adjs)
     {
       gimple_seq extra_stmts = NULL;
-      id->param_body_adjs->modify_gimple_stmt (&copy, &extra_stmts);
+      id->param_body_adjs->modify_gimple_stmt (&copy, &extra_stmts, stmt);
       if (!gimple_seq_empty_p (extra_stmts))
 	{
 	  memset (&wi, 0, sizeof (wi));
@@ -4721,7 +4721,6 @@ expand_call_inline (basic_block bb, gimple *stmt, copy_body_data *id,
   use_operand_p use;
   gimple *simtenter_stmt = NULL;
   vec<tree> *simtvars_save;
-  clone_info *info;
 
   /* The gimplifier uses input_location in too many places, such as
      internal_get_tmp_var ().  */
@@ -5046,40 +5045,6 @@ expand_call_inline (basic_block bb, gimple *stmt, copy_body_data *id,
   /* Add local vars in this inlined callee to caller.  */
   add_local_variables (id->src_cfun, cfun, id);
 
-  info = clone_info::get (id->src_node);
-  if (info && info->performed_splits)
-    {
-      clone_info *dst_info = clone_info::get_create (id->dst_node);
-      /* Any calls from the inlined function will be turned into calls from the
-	 function we inline into.  We must preserve notes about how to split
-	 parameters such calls should be redirected/updated.  */
-      unsigned len = vec_safe_length (info->performed_splits);
-      for (unsigned i = 0; i < len; i++)
-	{
-	  ipa_param_performed_split ps
-	    = (*info->performed_splits)[i];
-	  ps.dummy_decl = remap_decl (ps.dummy_decl, id);
-	  vec_safe_push (dst_info->performed_splits, ps);
-	}
-
-      if (flag_checking)
-	{
-	  len = vec_safe_length (dst_info->performed_splits);
-	  for (unsigned i = 0; i < len; i++)
-	    {
-	      ipa_param_performed_split *ps1
-		= &(*dst_info->performed_splits)[i];
-	      for (unsigned j = i + 1; j < len; j++)
-		{
-		  ipa_param_performed_split *ps2
-		    = &(*dst_info->performed_splits)[j];
-		  gcc_assert (ps1->dummy_decl != ps2->dummy_decl
-			      || ps1->unit_offset != ps2->unit_offset);
-		}
-	    }
-	}
-    }
-
   if (dump_enabled_p ())
     {
       char buf[128];
@@ -6103,23 +6068,10 @@ tree_versionable_function_p (tree fndecl)
 static void
 update_clone_info (copy_body_data * id)
 {
-  clone_info *dst_info = clone_info::get (id->dst_node);
-  vec<ipa_param_performed_split, va_gc> *cur_performed_splits
-    = dst_info ? dst_info->performed_splits : NULL;
-  if (cur_performed_splits)
-    {
-      unsigned len = cur_performed_splits->length ();
-      for (unsigned i = 0; i < len; i++)
-	{
-	  ipa_param_performed_split *ps = &(*cur_performed_splits)[i];
-	  ps->dummy_decl = remap_decl (ps->dummy_decl, id);
-	}
-    }
-
-  struct cgraph_node *node;
-  if (!id->dst_node->clones)
+  struct cgraph_node *this_node = id->dst_node;
+  if (!this_node->clones)
     return;
-  for (node = id->dst_node->clones; node != id->dst_node;)
+  for (cgraph_node *node = this_node->clones; node != this_node;)
     {
       /* First update replace maps to match the new body.  */
       clone_info *info = clone_info::get (node);
@@ -6133,53 +6085,6 @@ update_clone_info (copy_body_data * id)
 	      walk_tree (&replace_info->new_tree, copy_tree_body_r, id, NULL);
 	    }
 	}
-      if (info && info->performed_splits)
-	{
-	  unsigned len = vec_safe_length (info->performed_splits);
-	  for (unsigned i = 0; i < len; i++)
-	    {
-	      ipa_param_performed_split *ps
-		= &(*info->performed_splits)[i];
-	      ps->dummy_decl = remap_decl (ps->dummy_decl, id);
-	    }
-	}
-      if (unsigned len = vec_safe_length (cur_performed_splits))
-	{
-	  /* We do not want to add current performed splits when we are saving
-	     a copy of function body for later during inlining, that would just
-	     duplicate all entries.  So let's have a look whether anything
-	     referring to the first dummy_decl is present.  */
-	  if (!info)
-	    info = clone_info::get_create (node);
-	  unsigned dst_len = vec_safe_length (info->performed_splits);
-	  ipa_param_performed_split *first = &(*cur_performed_splits)[0];
-	  for (unsigned i = 0; i < dst_len; i++)
-	    if ((*info->performed_splits)[i].dummy_decl
-		== first->dummy_decl)
-	      {
-		len = 0;
-		break;
-	      }
-
-	  for (unsigned i = 0; i < len; i++)
-	    vec_safe_push (info->performed_splits,
-			   (*cur_performed_splits)[i]);
-	  if (flag_checking)
-	    {
-	      for (unsigned i = 0; i < dst_len; i++)
-		{
-		  ipa_param_performed_split *ps1
-		    = &(*info->performed_splits)[i];
-		  for (unsigned j = i + 1; j < dst_len; j++)
-		    {
-		      ipa_param_performed_split *ps2
-			= &(*info->performed_splits)[j];
-		      gcc_assert (ps1->dummy_decl != ps2->dummy_decl
-				  || ps1->unit_offset != ps2->unit_offset);
-		    }
-		}
-	    }
-	}
 
       if (node->clones)
 	node = node->clones;
-- 
2.31.1




On Mon, May 10 2021, Martin Jambor wrote:
> Hi,

>

> On Mon, May 10 2021, Richard Biener wrote:

>> I've tried to have a look at this patch but it does a lot of IPA specific

>> refactoring(?), so the actual DCE bits are hard to find.  Is it possible

>> to split the patch up or is it too entangled?

>>

>

> Yes:

>

> I was asked by Richi to split my fix for PR 93385 for easier review

> into IPA-SRA materialization refactoring and the actual DCE addition.

> Fortunately it was mostly natural except for a temporary weird

> condition in ipa_param_body_adjustments::modify_call_stmt.

>

> This is the first part which basically replaces performed_splits in

> clone_info and the code which generates it, keeps it up-to-date and

> consumes it with new edge summaries which are much nicer.  It simply

> contains 1) a mapping from the original argument indices to the actual

> indices in the call statement as it is now, 2) information needed to

> identify arguments representing pass-through IPA-SRA splits with which

> have been added to the call arguments in place of an original

> argument/reference and 3) a delta to the index where va_args may start

> - so basically directly all the information that the consumer of

> performed_splits had to compute and we also do not need the weird

> dummy declarations.

>

> The main disadvantage is that the information has to be created (and

> kept up-to-date) for all call graph edges associated with the given

> statement from all clones (including inline clones) of the clone where

> splitting or removal happened first.  But all of this happens during

> clone materialization so the only effect on WPA memory consumption is

> the removal of a pointer from clone_info.

>

> The statement modification code also has to know the statement from

> the original function in order to be able to locate the edge summaries

> which at this point are still keyed to these.  However, the code is

> already quite heavily dependant on how things are structured in

> tree-inline.c and in order to fix bugs like these it probably has to

> be.

>

> The subsequent patch needs this new information to be able to remove

> arguments from calls during materialization and communicate this

> information to the call redirection.

>

> The patch this one is split off introduced a field of

> ipa_param_body_adjustments called m_new_call_arg_modification_info which

> was not needed for anything, I have removed it.

>

> The patch is so far only lightly tested but I have verified that

> together with the second one they make up pretty much exactly the

> original one (modulo m_new_call_arg_modification_info) which I did

> bootstrap this morning.  I will of course bootstrap it independently

> too.

>

> What do you think?

>

> Martin

>

>

> 2021-05-10  Martin Jambor  <mjambor@suse.cz>

>

> 	PR ipa/93385

> 	* symtab-clones.h (clone_info): Removed member param_adjustments.

> 	* ipa-param-manipulation.h: Adjust initial comment to reflect how we

> 	deal with pass-through splits now.

> 	(ipa_param_performed_split): Removed.

> 	(ipa_param_adjustments::modify_call): Adjusted parameters.

> 	(class ipa_param_body_adjustments): Adjusted parameters of

> 	register_replacement, modify_gimple_stmt and modify_call_stmt.

> 	(ipa_verify_edge_has_no_modifications): Declare.

> 	* cgraph.c (cgraph_edge::redirect_call_stmt_to_callee): Remove

> 	performed_splits processing, pas only edge to padjs->modify_call,

> 	check that call arguments were not modified if they should not have

> 	been.

> 	* cgraphclones.c (cgraph_node::create_clone): Do not copy performed

> 	splits.

> 	* ipa-param-manipulation.c (struct pass_through_split_map): New type.

> 	(ipa_edge_modification_info): Likewise.

> 	(ipa_edge_modification_sum): Likewise.

> 	(ipa_edge_modifications): New edge summary.

> 	(ipa_verify_edge_has_no_modifications): New function.

> 	(transitive_split_p): Removed.

> 	(transitive_split_map): Likewise.

> 	(init_transitive_splits): Likewise.

> 	(ipa_param_adjustments::modify_call): Adjusted to use the new edge

> 	summary instead of performed_splits.

> 	(ipa_param_body_adjustments::register_replacement): Drop dummy

> 	parameter, set base_index of the created ipa_param_body_replacement.

> 	(phi_arg_will_live_p): New function.

> 	(ipa_param_body_adjustments::common_initialization): Do not create

> 	IPA_SRA dummy decls.

> 	(simple_tree_swap_info): Removed.

> 	(remap_split_decl_to_dummy): Likewise.

> 	(record_argument_state_1): New function.

> 	(record_argument_state): Likewise.

> 	(ipa_param_body_adjustments::modify_call_stmt): New parameter

> 	orig_stmt.  Do not work with dummy decls, save necessary info about

> 	changes to ipa_edge_modifications.

> 	(ipa_param_body_adjustments::modify_gimple_stmt): New parameter

> 	orig_stmt, pass it to modify_call_stmt.

> 	(ipa_param_body_adjustments::modify_cfun_body): Adjust call to

> 	modify_gimple_stmt.

> 	* tree-inline.c (remap_gimple_stmt): Pass original statement to

> 	modify_gimple_stmt.

> 	(copy_phis_for_bb): Do not copy dead PHI nodes.

> 	(expand_call_inline): Do not remap performed_splits.

> 	(update_clone_info): Likewise.

> ---

>  gcc/cgraph.c                 |  22 +-

>  gcc/cgraphclones.c           |   3 -

>  gcc/ipa-param-manipulation.c | 784 +++++++++++++++++++----------------

>  gcc/ipa-param-manipulation.h |  81 ++--

>  gcc/symtab-clones.h          |  15 +-

>  gcc/tree-inline.c            | 103 +----

>  6 files changed, 465 insertions(+), 543 deletions(-)

>

> diff --git a/gcc/cgraph.c b/gcc/cgraph.c

> index d7c78d518bc..d473da5a325 100644

> --- a/gcc/cgraph.c

> +++ b/gcc/cgraph.c

> @@ -1506,8 +1506,6 @@ cgraph_edge::redirect_call_stmt_to_callee (cgraph_edge *e)

>      }

>  

>    clone_info *callee_info = clone_info::get (e->callee);

> -  clone_info *caller_info = clone_info::get (e->caller);

> -

>    if (symtab->dump_file)

>      {

>        fprintf (symtab->dump_file, "updating call of %s -> %s: ",

> @@ -1515,18 +1513,6 @@ cgraph_edge::redirect_call_stmt_to_callee (cgraph_edge *e)

>        print_gimple_stmt (symtab->dump_file, e->call_stmt, 0, dump_flags);

>        if (callee_info && callee_info->param_adjustments)

>  	callee_info->param_adjustments->dump (symtab->dump_file);

> -      unsigned performed_len

> -	= caller_info ? vec_safe_length (caller_info->performed_splits) : 0;

> -      if (performed_len > 0)

> -	fprintf (symtab->dump_file, "Performed splits records:\n");

> -      for (unsigned i = 0; i < performed_len; i++)

> -	{

> -	  ipa_param_performed_split *sm

> -	    = &(*caller_info->performed_splits)[i];

> -	  print_node_brief (symtab->dump_file, "  dummy_decl: ", sm->dummy_decl,

> -			    TDF_UID);

> -	  fprintf (symtab->dump_file, ", unit_offset: %u\n", sm->unit_offset);

> -	}

>      }

>  

>    if (ipa_param_adjustments *padjs

> @@ -1541,10 +1527,7 @@ cgraph_edge::redirect_call_stmt_to_callee (cgraph_edge *e)

>  	remove_stmt_from_eh_lp (e->call_stmt);

>  

>        tree old_fntype = gimple_call_fntype (e->call_stmt);

> -      new_stmt = padjs->modify_call (e->call_stmt,

> -				     caller_info

> -				     ? caller_info->performed_splits : NULL,

> -				     e->callee->decl, false);

> +      new_stmt = padjs->modify_call (e, false);

>        cgraph_node *origin = e->callee;

>        while (origin->clone_of)

>  	origin = origin->clone_of;

> @@ -1564,6 +1547,9 @@ cgraph_edge::redirect_call_stmt_to_callee (cgraph_edge *e)

>      }

>    else

>      {

> +      if (flag_checking

> +	  && !fndecl_built_in_p (e->callee->decl, BUILT_IN_UNREACHABLE))

> +	ipa_verify_edge_has_no_modifications (e);

>        new_stmt = e->call_stmt;

>        gimple_call_set_fndecl (new_stmt, e->callee->decl);

>        update_stmt_fn (DECL_STRUCT_FUNCTION (e->caller->decl), new_stmt);

> diff --git a/gcc/cgraphclones.c b/gcc/cgraphclones.c

> index 9f86463b42d..7e463acab91 100644

> --- a/gcc/cgraphclones.c

> +++ b/gcc/cgraphclones.c

> @@ -414,9 +414,6 @@ cgraph_node::create_clone (tree new_decl, profile_count prof_count,

>    else if (info && info->param_adjustments)

>      clone_info::get_create (new_node)->param_adjustments

>  	 = info->param_adjustments;

> -  if (info && info->performed_splits)

> -    clone_info::get_create (new_node)->performed_splits

> -	 = vec_safe_copy (info->performed_splits);

>    new_node->split_part = split_part;

>  

>    FOR_EACH_VEC_ELT (redirect_callers, i, e)

> diff --git a/gcc/ipa-param-manipulation.c b/gcc/ipa-param-manipulation.c

> index 1d1e64f546a..424b8e5343f 100644

> --- a/gcc/ipa-param-manipulation.c

> +++ b/gcc/ipa-param-manipulation.c

> @@ -62,6 +62,80 @@ static const char *ipa_param_op_names[IPA_PARAM_PREFIX_COUNT]

>       "IPA_PARAM_OP_NEW",

>       "IPA_PARAM_OP_SPLIT"};

>  

> +/* Structure to hold declarations representing pass-through IPA-SRA splits.  In

> +   essence, it tells new index for a combination of original index and

> +   offset.  */

> +

> +struct pass_through_split_map

> +{

> +  /* Original argument index.  */

> +  unsigned base_index;

> +  /* Offset of the split part in the original argument.  */

> +  unsigned unit_offset;

> +  /* Index of the split part in the call statement - where clone

> +     materialization put it.  */

> +  int new_index;

> +};

> +

> +/* Information about some call statements that needs to be conveyed from clone

> +   materialization to edge redirection. */

> +

> +class ipa_edge_modification_info

> +{

> + public:

> +  ipa_edge_modification_info ()

> +    {}

> +

> +  /* Mapping of original argument indices to where those arguments sit in the

> +     call statement now or to a negative index if they were removed.  */

> +  auto_vec<int> index_map;

> +  /* Information about ISRA replacements put into the call statement at the

> +     clone materialization stages.  */

> +  auto_vec<pass_through_split_map> pass_through_map;

> +  /* Necessary adjustment to ipa_param_adjustments::m_always_copy_start when

> +     redirecting the call.  */

> +  int always_copy_delta = 0;

> +};

> +

> +/* Class for storing and retrieving summaries about cal statement

> +   modifications.  */

> +

> +class ipa_edge_modification_sum

> +  : public call_summary <ipa_edge_modification_info *>

> +{

> + public:

> +  ipa_edge_modification_sum (symbol_table *table)

> +    : call_summary<ipa_edge_modification_info *> (table)

> +  {

> +  }

> +

> +  /* Hook that is called by summary when an edge is duplicated.  */

> +

> +  virtual void duplicate (cgraph_edge *,

> +			  cgraph_edge *,

> +			  ipa_edge_modification_info *old_info,

> +			  ipa_edge_modification_info *new_info)

> +  {

> +    new_info->index_map.safe_splice (old_info->index_map);

> +    new_info->pass_through_map.safe_splice (old_info->pass_through_map);

> +    new_info->always_copy_delta = old_info->always_copy_delta;

> +  }

> +};

> +

> +/* Call summary to store information about edges which have had their arguments

> +   partially modified already.  */

> +

> +static ipa_edge_modification_sum *ipa_edge_modifications;

> +

> +/* Fail compilation if CS has any summary associated with it in

> +   ipa_edge_modifications.  */

> +

> +DEBUG_FUNCTION void

> +ipa_verify_edge_has_no_modifications (cgraph_edge *cs)

> +{

> +  gcc_assert (!ipa_edge_modifications || !ipa_edge_modifications->get (cs));

> +}

> +

>  /* Fill an empty vector ARGS with PARM_DECLs representing formal parameters of

>     FNDECL.  The function should not be called during LTO WPA phase except for

>     thunks (or functions with bodies streamed in). */

> @@ -459,147 +533,46 @@ isra_get_ref_base_and_offset (tree expr, tree *base_p, unsigned *unit_offset_p)

>    return true;

>  }

>  

> -/* Return true if EXPR describes a transitive split (i.e. one that happened for

> -   both the caller and the callee) as recorded in PERFORMED_SPLITS.  In that

> -   case, store index of the respective record in PERFORMED_SPLITS into

> -   *SM_IDX_P and the unit offset from all handled components in EXPR into

> -   *UNIT_OFFSET_P.  */

> -

> -static bool

> -transitive_split_p (vec<ipa_param_performed_split, va_gc> *performed_splits,

> -		    tree expr, unsigned *sm_idx_p, unsigned *unit_offset_p)

> -{

> -  tree base;

> -  if (!isra_get_ref_base_and_offset (expr, &base, unit_offset_p))

> -    return false;

> -

> -  if (TREE_CODE (base) == SSA_NAME)

> -    {

> -      base = SSA_NAME_VAR (base);

> -      if (!base)

> -	return false;

> -    }

> -

> -  unsigned len = vec_safe_length (performed_splits);

> -  for (unsigned i = 0 ; i < len; i++)

> -    {

> -      ipa_param_performed_split *sm = &(*performed_splits)[i];

> -      if (sm->dummy_decl == base)

> -	{

> -	  *sm_idx_p = i;

> -	  return true;

> -	}

> -    }

> -  return false;

> -}

> -

> -/* Structure to hold declarations representing transitive IPA-SRA splits.  In

> -   essence, if we need to pass UNIT_OFFSET of a parameter which originally has

> -   number BASE_INDEX, we should pass down REPL.  */

> -

> -struct transitive_split_map

> -{

> -  tree repl;

> -  unsigned base_index;

> -  unsigned unit_offset;

> -};

> -

> -/* If call STMT contains any parameters representing transitive splits as

> -   described by PERFORMED_SPLITS, return the number of extra parameters that

> -   were addded during clone materialization and fill in INDEX_MAP with adjusted

> -   indices of corresponding original parameters and TRANS_MAP with description

> -   of all transitive replacement descriptions.  Otherwise return zero. */

> -

> -static unsigned

> -init_transitive_splits (vec<ipa_param_performed_split, va_gc> *performed_splits,

> -			gcall *stmt, vec <unsigned> *index_map,

> -			auto_vec <transitive_split_map> *trans_map)

> -{

> -  unsigned phony_arguments = 0;

> -  unsigned stmt_idx = 0, base_index = 0;

> -  unsigned nargs = gimple_call_num_args (stmt);

> -  while (stmt_idx < nargs)

> -    {

> -      unsigned unit_offset_delta;

> -      tree base_arg = gimple_call_arg (stmt, stmt_idx);

> -

> -      if (phony_arguments > 0)

> -	index_map->safe_push (stmt_idx);

> -

> -      unsigned sm_idx;

> -      stmt_idx++;

> -      if (transitive_split_p (performed_splits, base_arg, &sm_idx,

> -			      &unit_offset_delta))

> -	{

> -	  if (phony_arguments == 0)

> -	    /* We have optimistically avoided constructing index_map do far but

> -	       now it is clear it will be necessary, so let's create the easy

> -	       bit we skipped until now.  */

> -	    for (unsigned k = 0; k < stmt_idx; k++)

> -	      index_map->safe_push (k);

> -

> -	  tree dummy = (*performed_splits)[sm_idx].dummy_decl;

> -	  for (unsigned j = sm_idx; j < performed_splits->length (); j++)

> -	    {

> -	      ipa_param_performed_split *caller_split

> -		= &(*performed_splits)[j];

> -	      if (caller_split->dummy_decl != dummy)

> -		break;

> -

> -	      tree arg = gimple_call_arg (stmt, stmt_idx);

> -	      struct transitive_split_map tsm;

> -	      tsm.repl = arg;

> -	      tsm.base_index = base_index;

> -	      if (caller_split->unit_offset >= unit_offset_delta)

> -		{

> -		  tsm.unit_offset

> -		    = (caller_split->unit_offset - unit_offset_delta);

> -		  trans_map->safe_push (tsm);

> -		}

> -

> -	      phony_arguments++;

> -	      stmt_idx++;

> -	    }

> -	}

> -      base_index++;

> -    }

> -  return phony_arguments;

> -}

> -

> -/* Modify actual arguments of a function call in statement STMT, assuming it

> -   calls CALLEE_DECL.  CALLER_ADJ must be the description of parameter

> -   adjustments of the caller or NULL if there are none.  Return the new

> -   statement that replaced the old one.  When invoked, cfun and

> -   current_function_decl have to be set to the caller.  */

> +/* Modify actual arguments of a function call in statement currently belonging

> +   to CS, and make it call CS->callee->decl.  Return the new statement that

> +   replaced the old one.  When invoked, cfun and current_function_decl have to

> +   be set to the caller.  */

>  

>  gcall *

> -ipa_param_adjustments::modify_call (gcall *stmt,

> -				    vec<ipa_param_performed_split,

> -				        va_gc> *performed_splits,

> -				    tree callee_decl, bool update_references)

> +ipa_param_adjustments::modify_call (cgraph_edge *cs,

> +				    bool update_references)

>  {

> +  gcall *stmt = cs->call_stmt;

> +  tree callee_decl = cs->callee->decl;

> +

> +  ipa_edge_modification_info *mod_info

> +    = ipa_edge_modifications ? ipa_edge_modifications->get (cs) : NULL;

> +  if (mod_info && symtab->dump_file)

> +    {

> +      fprintf (symtab->dump_file, "Information about pre-exiting "

> +	       "modifications.\n  Index map:");

> +      unsigned idx_len = mod_info->index_map.length ();

> +      for (unsigned i = 0; i < idx_len; i++)

> +	fprintf (symtab->dump_file, " %i", mod_info->index_map[i]);

> +      fprintf (symtab->dump_file, "\n  Pass-through split map: ");

> +      unsigned ptm_len = mod_info->pass_through_map.length ();

> +      for (unsigned i = 0; i < ptm_len; i++)

> +	fprintf (symtab->dump_file,

> +		 " (base_index: %u, offset: %u, new_index: %i)",

> +		 mod_info->pass_through_map[i].base_index,

> +		 mod_info->pass_through_map[i].unit_offset,

> +		 mod_info->pass_through_map[i].new_index);

> +      fprintf (symtab->dump_file, "\n  Always-copy delta: %i\n",

> +	       mod_info->always_copy_delta);

> +    }

> +

>    unsigned len = vec_safe_length (m_adj_params);

>    auto_vec<tree, 16> vargs (len);

> -  tree old_decl = gimple_call_fndecl (stmt);

>    unsigned old_nargs = gimple_call_num_args (stmt);

> +  unsigned orig_nargs = mod_info ? mod_info->index_map.length () : old_nargs;

>    auto_vec<bool, 16> kept (old_nargs);

>    kept.quick_grow_cleared (old_nargs);

>  

> -  auto_vec <unsigned, 16> index_map;

> -  auto_vec <transitive_split_map> trans_map;

> -  bool transitive_remapping = false;

> -

> -  if (performed_splits)

> -    {

> -      unsigned removed = init_transitive_splits (performed_splits,

> -						 stmt, &index_map, &trans_map);

> -      if (removed > 0)

> -	{

> -	  transitive_remapping = true;

> -	  old_nargs -= removed;

> -	}

> -    }

> -

>    cgraph_node *current_node = cgraph_node::get (current_function_decl);

>    if (update_references)

>      current_node->remove_stmt_references (stmt);

> @@ -612,13 +585,16 @@ ipa_param_adjustments::modify_call (gcall *stmt,

>        ipa_adjusted_param *apm = &(*m_adj_params)[i];

>        if (apm->op == IPA_PARAM_OP_COPY)

>  	{

> -	  unsigned index = apm->base_index;

> -	  if (index >= old_nargs)

> +	  int index = apm->base_index;

> +	  if ((unsigned) index >= orig_nargs)

>  	    /* Can happen if the original call has argument mismatch,

>  	       ignore.  */

>  	    continue;

> -	  if (transitive_remapping)

> -	    index = index_map[apm->base_index];

> +	  if (mod_info)

> +	    {

> +	      index = mod_info->index_map[apm->base_index];

> +	      gcc_assert (index >= 0);

> +	    }

>  

>  	  tree arg = gimple_call_arg (stmt, index);

>  

> @@ -636,14 +612,17 @@ ipa_param_adjustments::modify_call (gcall *stmt,

>  	 materialization.  */

>        gcc_assert (apm->op == IPA_PARAM_OP_SPLIT);

>  

> -      /* We have to handle transitive changes differently using the maps we

> -	 have created before.  So look into them first.  */

> +      /* We have to handle pass-through changes differently using the map

> +	 clone materialziation might have left behind.  */

>        tree repl = NULL_TREE;

> -      for (unsigned j = 0; j < trans_map.length (); j++)

> -	if (trans_map[j].base_index == apm->base_index

> -	    && trans_map[j].unit_offset == apm->unit_offset)

> +      unsigned ptm_len = mod_info ? mod_info->pass_through_map.length () : 0;

> +      for (unsigned j = 0; j < ptm_len; j++)

> +	if (mod_info->pass_through_map[j].base_index == apm->base_index

> +	    && mod_info->pass_through_map[j].unit_offset == apm->unit_offset)

>  	  {

> -	    repl = trans_map[j].repl;

> +	    int repl_idx = mod_info->pass_through_map[j].new_index;

> +	    gcc_assert (repl_idx >= 0);

> +	    repl = gimple_call_arg (stmt, repl_idx);

>  	    break;

>  	  }

>        if (repl)

> @@ -652,12 +631,15 @@ ipa_param_adjustments::modify_call (gcall *stmt,

>  	  continue;

>  	}

>  

> -      unsigned index = apm->base_index;

> -      if (index >= old_nargs)

> +      int index = apm->base_index;

> +      if ((unsigned) index >= orig_nargs)

>  	/* Can happen if the original call has argument mismatch, ignore.  */

>  	continue;

> -      if (transitive_remapping)

> -	index = index_map[apm->base_index];

> +      if (mod_info)

> +	{

> +	  index = mod_info->index_map[apm->base_index];

> +	  gcc_assert (index >= 0);

> +	}

>        tree base = gimple_call_arg (stmt, index);

>  

>        /* We create a new parameter out of the value of the old one, we can

> @@ -773,8 +755,16 @@ ipa_param_adjustments::modify_call (gcall *stmt,

>      }

>  

>    if (m_always_copy_start >= 0)

> -    for (unsigned i = m_always_copy_start; i < old_nargs; i++)

> -      vargs.safe_push (gimple_call_arg (stmt, i));

> +    {

> +      int always_copy_start = m_always_copy_start;

> +      if (mod_info)

> +	{

> +	  always_copy_start += mod_info->always_copy_delta;

> +	  gcc_assert (always_copy_start >= 0);

> +	}

> +      for (unsigned i = always_copy_start; i < old_nargs; i++)

> +	vargs.safe_push (gimple_call_arg (stmt, i));

> +    }

>  

>    /* For optimized away parameters, add on the caller side

>       before the call

> @@ -782,6 +772,7 @@ ipa_param_adjustments::modify_call (gcall *stmt,

>       stmts and associate D#X with parm in decl_debug_args_lookup

>       vector to say for debug info that if parameter parm had been passed,

>       it would have value parm_Y(D).  */

> +  tree old_decl = gimple_call_fndecl (stmt);

>    if (MAY_HAVE_DEBUG_BIND_STMTS && old_decl && callee_decl)

>      {

>        vec<tree, va_gc> **debug_args = NULL;

> @@ -799,13 +790,17 @@ ipa_param_adjustments::modify_call (gcall *stmt,

>  	{

>  	  if (!is_gimple_reg (old_parm) || kept[i])

>  	    continue;

> -	  tree origin = DECL_ORIGIN (old_parm);

>  	  tree arg;

> -	  if (transitive_remapping)

> -	    arg = gimple_call_arg (stmt, index_map[i]);

> +	  if (mod_info)

> +	    {

> +	      if (mod_info->index_map[i] < 0)

> +		continue;

> +	      arg = gimple_call_arg (stmt, mod_info->index_map[i]);

> +	    }

>  	  else

>  	    arg = gimple_call_arg (stmt, i);

>  

> +	  tree origin = DECL_ORIGIN (old_parm);

>  	  if (!useless_type_conversion_p (TREE_TYPE (origin), TREE_TYPE (arg)))

>  	    {

>  	      if (!fold_convertible_p (TREE_TYPE (origin), arg))

> @@ -909,6 +904,9 @@ ipa_param_adjustments::modify_call (gcall *stmt,

>  	gsi_prev (&gsi);

>        }

>      while (gsi_stmt (gsi) != gsi_stmt (prev_gsi));

> +

> +  if (mod_info)

> +    ipa_edge_modifications->remove (cs);

>    return new_stmt;

>  }

>  

> @@ -931,13 +929,11 @@ ipa_param_adjustments::debug ()

>    dump (stderr);

>  }

>  

> -/* Register that REPLACEMENT should replace parameter described in APM and

> -   optionally as DUMMY to mark transitive splits across calls.  */

> +/* Register that REPLACEMENT should replace parameter described in APM.  */

>  

>  void

>  ipa_param_body_adjustments::register_replacement (ipa_adjusted_param *apm,

> -						  tree replacement,

> -						  tree dummy)

> +						  tree replacement)

>  {

>    gcc_checking_assert (apm->op == IPA_PARAM_OP_SPLIT

>  		       || apm->op == IPA_PARAM_OP_NEW);

> @@ -945,7 +941,6 @@ ipa_param_body_adjustments::register_replacement (ipa_adjusted_param *apm,

>    ipa_param_body_replacement psr;

>    psr.base = m_oparms[apm->prev_clone_index];

>    psr.repl = replacement;

> -  psr.dummy = dummy;

>    psr.unit_offset = apm->unit_offset;

>    m_replacements.safe_push (psr);

>  }

> @@ -1007,9 +1002,6 @@ ipa_param_body_adjustments::common_initialization (tree old_fndecl,

>    auto_vec<bool, 16> kept;

>    kept.reserve_exact (m_oparms.length ());

>    kept.quick_grow_cleared (m_oparms.length ());

> -  auto_vec<tree, 16> isra_dummy_decls;

> -  isra_dummy_decls.reserve_exact (m_oparms.length ());

> -  isra_dummy_decls.quick_grow_cleared (m_oparms.length ());

>  

>    unsigned adj_len = vec_safe_length (m_adj_params);

>    m_method2func = ((TREE_CODE (TREE_TYPE (m_fndecl)) == METHOD_TYPE)

> @@ -1055,35 +1047,7 @@ ipa_param_body_adjustments::common_initialization (tree old_fndecl,

>  	  if (apm->op == IPA_PARAM_OP_SPLIT)

>  	    {

>  	      m_split_modifications_p = true;

> -

> -	      if (m_id)

> -		{

> -		  tree dummy_decl;

> -		  if (!isra_dummy_decls[prev_index])

> -		    {

> -		      dummy_decl = copy_decl_to_var (m_oparms[prev_index],

> -						     m_id);

> -		      /* Any attempt to remap this dummy in this particular

> -			 instance of clone materialization should yield

> -			 itself.  */

> -		      insert_decl_map (m_id, dummy_decl, dummy_decl);

> -

> -		      DECL_CHAIN (dummy_decl) = *vars;

> -		      *vars = dummy_decl;

> -		      isra_dummy_decls[prev_index] = dummy_decl;

> -		    }

> -		  else

> -		    dummy_decl = isra_dummy_decls[prev_index];

> -

> -		  register_replacement (apm, new_parm, dummy_decl);

> -		  ipa_param_performed_split ps;

> -		  ps.dummy_decl = dummy_decl;

> -		  ps.unit_offset = apm->unit_offset;

> -		  vec_safe_push (clone_info::get_create

> -				   (m_id->dst_node)->performed_splits, ps);

> -		}

> -	      else

> -		register_replacement (apm, new_parm);

> +	      register_replacement (apm, new_parm);

>  	    }

>          }

>        else

> @@ -1110,8 +1074,6 @@ ipa_param_body_adjustments::common_initialization (tree old_fndecl,

>  	  {

>  	    if (!m_id->decl_map->get (m_oparms[i]))

>  	      {

> -		/* TODO: Perhaps at least aggregate-type params could re-use

> -		   their isra_dummy_decl here?  */

>  		tree var = copy_decl_to_var (m_oparms[i], m_id);

>  		insert_decl_map (m_id, m_oparms[i], var);

>  		/* Declare this new variable.  */

> @@ -1502,218 +1464,327 @@ ipa_param_body_adjustments::modify_assignment (gimple *stmt,

>    return any;

>  }

>  

> -/* Data passed to remap_split_decl_to_dummy through walk_tree.  */

> +/* Record information about what modifications to call arguments have already

> +   been done by clone materialization into a summary describing CS.  The

> +   information is stored in NEW_INDEX_MAP, NEW_PT_MAP and NEW_ALWAYS_COPY_DELTA

> +   and correspond to equivalent fields in ipa_edge_modification_info.  Return

> +   the edge summary.  */

> +

> +static ipa_edge_modification_info *

> +record_argument_state_1 (cgraph_edge *cs, const vec<int> &new_index_map,

> +			 const vec<pass_through_split_map> &new_pt_map,

> +			 int new_always_copy_delta)

>  

> -struct simple_tree_swap_info

>  {

> -  /* Change FROM to TO.  */

> -  tree from, to;

> -  /* And set DONE to true when doing so.  */

> -  bool done;

> -};

> +  ipa_edge_modification_info *sum = ipa_edge_modifications->get_create (cs);

>  

> -/* Simple remapper to remap a split parameter to the same expression based on a

> -   special dummy decl so that edge redirections can detect transitive splitting

> -   and finish them.  */

> -

> -static tree

> -remap_split_decl_to_dummy (tree *tp, int *walk_subtrees, void *data)

> -{

> -  tree t = *tp;

> -

> -  if (DECL_P (t) || TREE_CODE (t) == SSA_NAME)

> +  unsigned len = sum->pass_through_map.length ();

> +  for (unsigned i = 0; i < len; i++)

>      {

> -      struct simple_tree_swap_info *swapinfo

> -	= (struct simple_tree_swap_info *) data;

> -      if (t == swapinfo->from

> -	  || (TREE_CODE (t) == SSA_NAME

> -	      && SSA_NAME_VAR (t) == swapinfo->from))

> -	{

> -	  *tp = swapinfo->to;

> -	  swapinfo->done = true;

> -	}

> -      *walk_subtrees = 0;

> +      unsigned oldnew = sum->pass_through_map[i].new_index;

> +      sum->pass_through_map[i].new_index = new_index_map[oldnew];

> +    }

> +

> +  len = sum->index_map.length ();

> +  if (len > 0)

> +    {

> +      unsigned nptlen = new_pt_map.length ();

> +      for (unsigned j = 0; j < nptlen; j++)

> +	{

> +	  int inverse = -1;

> +	  for (unsigned i = 0; i < len ; i++)

> +	    if ((unsigned) sum->index_map[i] == new_pt_map[j].base_index)

> +	    {

> +	      inverse = i;

> +	      break;

> +	    }

> +	  gcc_assert (inverse >= 0);

> +	  pass_through_split_map ptm_item;

> +

> +	  ptm_item.base_index = inverse;

> +	  ptm_item.unit_offset = new_pt_map[j].unit_offset;

> +	  ptm_item.new_index = new_pt_map[j].new_index;

> +	  sum->pass_through_map.safe_push (ptm_item);

> +	}

> +

> +      for (unsigned i = 0; i < len; i++)

> +	{

> +	  int idx = sum->index_map[i];

> +	  if (idx < 0)

> +	    continue;

> +	  sum->index_map[i] = new_index_map[idx];

> +	}

>      }

> -  else if (TYPE_P (t))

> -      *walk_subtrees = 0;

>    else

> -    *walk_subtrees = 1;

> -  return NULL_TREE;

> +    {

> +      sum->pass_through_map.safe_splice (new_pt_map);

> +      sum->index_map.safe_splice (new_index_map);

> +    }

> +  sum->always_copy_delta += new_always_copy_delta;

> +  return sum;

>  }

>  

> +/* Record information about what modifications to call arguments have already

> +   been done by clone materialization into a summary of an edge describing the

> +   call in this clone and all its clones.  NEW_INDEX_MAP, NEW_PT_MAP and

> +   NEW_ALWAYS_COPY_DELTA have the same meaning as record_argument_state_1.

> +

> +   In order to associate the info with the right edge summaries, we need

> +   address of the ORIG_STMT in the function from which we are cloning (because

> +   the edges have not yet been re-assigned to the new statement that has just

> +   been created) and ID, the structure governing function body copying.  */

> +

> +static void

> +record_argument_state (copy_body_data *id, gimple *orig_stmt,

> +		       const vec<int> &new_index_map,

> +		       const vec<pass_through_split_map> &new_pt_map,

> +		       int new_always_copy_delta)

> +{

> +  if (!ipa_edge_modifications)

> +    ipa_edge_modifications = new ipa_edge_modification_sum (symtab);

> +

> +  struct cgraph_node *this_node = id->dst_node;

> +  ipa_edge_modification_info *first_sum = NULL;

> +  cgraph_edge *cs = this_node->get_edge (orig_stmt);

> +  if (cs)

> +    first_sum = record_argument_state_1 (cs, new_index_map, new_pt_map,

> +					 new_always_copy_delta);

> +  else

> +    gcc_assert (this_node->clones);

> +

> +  if (!this_node->clones)

> +    return;

> +  for (cgraph_node *subclone = this_node->clones; subclone != this_node;)

> +    {

> +      cs = subclone->get_edge (orig_stmt);

> +      if (cs)

> +	{

> +	  if (!first_sum)

> +	    first_sum = record_argument_state_1 (cs, new_index_map, new_pt_map,

> +						 new_always_copy_delta);

> +	  else

> +	    {

> +	      ipa_edge_modification_info *s2

> +		= ipa_edge_modifications->get_create (cs);

> +	      s2->index_map.truncate (0);

> +	      s2->index_map.safe_splice (first_sum->index_map);

> +	      s2->pass_through_map.truncate (0);

> +	      s2->pass_through_map.safe_splice (first_sum->pass_through_map);

> +	      s2->always_copy_delta = first_sum->always_copy_delta;

> +	    }

> +	}

> +      else

> +	gcc_assert (subclone->clones);

> +

> +      if (subclone->clones)

> +	subclone = subclone->clones;

> +      else if (subclone->next_sibling_clone)

> +	subclone = subclone->next_sibling_clone;

> +      else

> +	{

> +	  while (subclone != this_node && !subclone->next_sibling_clone)

> +	    subclone = subclone->clone_of;

> +	  if (subclone != this_node)

> +	    subclone = subclone->next_sibling_clone;

> +	}

> +    }

> +}

>  

>  /* If the call statement pointed at by STMT_P contains any expressions that

>     need to replaced with a different one as noted by ADJUSTMENTS, do so.  f the

>     statement needs to be rebuilt, do so.  Return true if any modifications have

> -   been performed.

> +   been performed.  ORIG_STMT, if not NULL, is the original statement in the

> +   function that is being cloned from, which at this point can be used to look

> +   up call_graph edges.

>  

>     If the method is invoked as a part of IPA clone materialization and if any

> -   parameter split is transitive, i.e. it applies to the functin that is being

> -   modified and also to the callee of the statement, replace the parameter

> -   passed to old callee with an equivalent expression based on a dummy decl

> -   followed by PARM_DECLs representing the actual replacements.  The actual

> -   replacements will be then converted into SSA_NAMEs and then

> -   ipa_param_adjustments::modify_call will find the appropriate ones and leave

> -   only those in the call.  */

> +   parameter split is pass-through, i.e. it applies to the functin that is

> +   being modified and also to the callee of the statement, replace the

> +   parameter passed to old callee with all of the replacement a callee might

> +   possibly want and record the performed argument modifications in

> +   ipa_edge_modifications.  Likewise if any argument has already been left out

> +   because it is not necessary.  */

>  

>  bool

> -ipa_param_body_adjustments::modify_call_stmt (gcall **stmt_p)

> +ipa_param_body_adjustments::modify_call_stmt (gcall **stmt_p,

> +					      gimple *orig_stmt)

>  {

> -  gcall *stmt = *stmt_p;

>    auto_vec <unsigned, 4> pass_through_args;

>    auto_vec <unsigned, 4> pass_through_pbr_indices;

> +  auto_vec <HOST_WIDE_INT, 4> pass_through_offsets;

> +  gcall *stmt = *stmt_p;

> +  unsigned nargs = gimple_call_num_args (stmt);

> +  bool recreate = false;

>  

> -  if (m_split_modifications_p && m_id)

> +  for (unsigned i = 0; i < gimple_call_num_args (stmt); i++)

>      {

> -      for (unsigned i = 0; i < gimple_call_num_args (stmt); i++)

> +      tree t = gimple_call_arg (stmt, i);

> +      gcc_assert (TREE_CODE (t) != BIT_FIELD_REF

> +		  && TREE_CODE (t) != IMAGPART_EXPR

> +		  && TREE_CODE (t) != REALPART_EXPR);

> +

> +      /* The follow-up patch will check whether t needs to be removed, that's

> +	 why this condition is in the loop.  */

> +

> +      if (!m_split_modifications_p)

> +	continue;

> +

> +      tree base;

> +      unsigned agg_arg_offset;

> +      if (!isra_get_ref_base_and_offset (t, &base, &agg_arg_offset))

> +	continue;

> +

> +      bool by_ref = false;

> +      if (TREE_CODE (base) == SSA_NAME)

>  	{

> -	  tree t = gimple_call_arg (stmt, i);

> -	  gcc_assert (TREE_CODE (t) != BIT_FIELD_REF

> -		      && TREE_CODE (t) != IMAGPART_EXPR

> -		      && TREE_CODE (t) != REALPART_EXPR);

> -

> -	  tree base;

> -	  unsigned unit_offset;

> -	  if (!isra_get_ref_base_and_offset (t, &base, &unit_offset))

> +	  if (!SSA_NAME_IS_DEFAULT_DEF (base))

>  	    continue;

> +	  base = SSA_NAME_VAR (base);

> +	  gcc_checking_assert (base);

> +	  by_ref = true;

> +	}

> +      if (TREE_CODE (base) != PARM_DECL)

> +	continue;

>  

> -	  bool by_ref = false;

> -	  if (TREE_CODE (base) == SSA_NAME)

> +      bool base_among_replacements = false;

> +      unsigned j, repl_list_len = m_replacements.length ();

> +      for (j = 0; j < repl_list_len; j++)

> +	{

> +	  ipa_param_body_replacement *pbr = &m_replacements[j];

> +	  if (pbr->base == base)

>  	    {

> -	      if (!SSA_NAME_IS_DEFAULT_DEF (base))

> -		continue;

> -	      base = SSA_NAME_VAR (base);

> -	      gcc_checking_assert (base);

> -	      by_ref = true;

> +	      base_among_replacements = true;

> +	      break;

>  	    }

> -	  if (TREE_CODE (base) != PARM_DECL)

> -	    continue;

> +	}

> +      if (!base_among_replacements)

> +	continue;

>  

> -	  bool base_among_replacements = false;

> -	  unsigned j, repl_list_len = m_replacements.length ();

> -	  for (j = 0; j < repl_list_len; j++)

> +      /* We still have to distinguish between an end-use that we have to

> +	 transform now and a pass-through, which happens in the following

> +	 two cases.  */

> +

> +      /* TODO: After we adjust ptr_parm_has_nonarg_uses to also consider

> +	 &MEM_REF[ssa_name + offset], we will also have to detect that case

> +	 here.    */

> +

> +      if (TREE_CODE (t) == SSA_NAME

> +	  && SSA_NAME_IS_DEFAULT_DEF (t)

> +	  && SSA_NAME_VAR (t)

> +	  && TREE_CODE (SSA_NAME_VAR (t)) == PARM_DECL)

> +	{

> +	  /* This must be a by_reference pass-through.  */

> +	  recreate = true;

> +	  gcc_assert (POINTER_TYPE_P (TREE_TYPE (t)));

> +	  pass_through_args.safe_push (i);

> +	  pass_through_pbr_indices.safe_push (j);

> +	  pass_through_offsets.safe_push (agg_arg_offset);

> +	}

> +      else if (!by_ref && AGGREGATE_TYPE_P (TREE_TYPE (t)))

> +	{

> +	  /* Currently IPA-SRA guarantees the aggregate access type

> +	     exactly matches in this case.  So if it does not match, it is

> +	     a pass-through argument that will be sorted out at edge

> +	     redirection time.  */

> +	  ipa_param_body_replacement *pbr

> +	    = lookup_replacement_1 (base, agg_arg_offset);

> +

> +	  if (!pbr

> +	      || (TYPE_MAIN_VARIANT (TREE_TYPE (t))

> +		  != TYPE_MAIN_VARIANT (TREE_TYPE (pbr->repl))))

>  	    {

> -	      ipa_param_body_replacement *pbr = &m_replacements[j];

> -	      if (pbr->base == base)

> -		{

> -		  base_among_replacements = true;

> -		  break;

> -		}

> -	    }

> -	  if (!base_among_replacements)

> -	    continue;

> -

> -	  /* We still have to distinguish between an end-use that we have to

> -	     transform now and a pass-through, which happens in the following

> -	     two cases.  */

> -

> -	  /* TODO: After we adjust ptr_parm_has_nonarg_uses to also consider

> -	     &MEM_REF[ssa_name + offset], we will also have to detect that case

> -	     here.    */

> -

> -	  if (TREE_CODE (t) == SSA_NAME

> -	      && SSA_NAME_IS_DEFAULT_DEF (t)

> -	      && SSA_NAME_VAR (t)

> -	      && TREE_CODE (SSA_NAME_VAR (t)) == PARM_DECL)

> -	    {

> -	      /* This must be a by_reference pass-through.  */

> -	      gcc_assert (POINTER_TYPE_P (TREE_TYPE (t)));

> +	      recreate = true;

>  	      pass_through_args.safe_push (i);

>  	      pass_through_pbr_indices.safe_push (j);

> -	    }

> -	  else if (!by_ref && AGGREGATE_TYPE_P (TREE_TYPE (t)))

> -	    {

> -	      /* Currently IPA-SRA guarantees the aggregate access type

> -		 exactly matches in this case.  So if it does not match, it is

> -		 a pass-through argument that will be sorted out at edge

> -		 redirection time.  */

> -	      ipa_param_body_replacement *pbr

> -		= lookup_replacement_1 (base, unit_offset);

> -

> -	      if (!pbr

> -		  || (TYPE_MAIN_VARIANT (TREE_TYPE (t))

> -		      != TYPE_MAIN_VARIANT (TREE_TYPE (pbr->repl))))

> -		{

> -		  pass_through_args.safe_push (i);

> -		  pass_through_pbr_indices.safe_push (j);

> -		}

> +	      pass_through_offsets.safe_push (agg_arg_offset);

>  	    }

>  	}

>      }

>  

> -  unsigned nargs = gimple_call_num_args (stmt);

> -  if (!pass_through_args.is_empty ())

> +  if (!recreate)

>      {

> -      auto_vec<tree, 16> vargs;

> -      unsigned pt_idx = 0;

> +      /* No need to rebuild the statement, let's just modify arguments

> +	 and the LHS if/as appropriate.  */

> +      bool modified = false;

>        for (unsigned i = 0; i < nargs; i++)

>  	{

> -	  if (pt_idx < pass_through_args.length ()

> -	      && i == pass_through_args[pt_idx])

> -	    {

> -	      unsigned j = pass_through_pbr_indices[pt_idx];

> -	      pt_idx++;

> -	      tree base = m_replacements[j].base;

> -

> -	      /* Map base will get mapped to the special transitive-isra marker

> -		 dummy decl. */

> -	      struct simple_tree_swap_info swapinfo;

> -	      swapinfo.from = base;

> -	      swapinfo.to = m_replacements[j].dummy;

> -	      swapinfo.done = false;

> -	      tree arg = gimple_call_arg (stmt, i);

> -	      walk_tree (&arg, remap_split_decl_to_dummy, &swapinfo, NULL);

> -	      gcc_assert (swapinfo.done);

> -	      vargs.safe_push (arg);

> -	      /* Now let's push all replacements pertaining to this parameter

> -		 so that all gimple register ones get correct SSA_NAMES.  Edge

> -		 redirection will weed out the dummy argument as well as all

> -		 unused replacements later.  */

> -	      unsigned int repl_list_len = m_replacements.length ();

> -	      for (; j < repl_list_len; j++)

> -		{

> -		  if (m_replacements[j].base != base)

> -		    break;

> -		  vargs.safe_push (m_replacements[j].repl);

> -		}

> -	    }

> -	  else

> -	    {

> -	      tree t = gimple_call_arg (stmt, i);

> -	      modify_expression (&t, true);

> -	      vargs.safe_push (t);

> -	    }

> +	  tree *t = gimple_call_arg_ptr (stmt, i);

> +	  modified |= modify_expression (t, true);

>  	}

> -      gcall *new_stmt = gimple_build_call_vec (gimple_call_fn (stmt), vargs);

> -      if (gimple_has_location (stmt))

> -	gimple_set_location (new_stmt, gimple_location (stmt));

> -      gimple_call_set_chain (new_stmt, gimple_call_chain (stmt));

> -      gimple_call_copy_flags (new_stmt, stmt);

> -      if (tree lhs = gimple_call_lhs (stmt))

> +      if (gimple_call_lhs (stmt))

>  	{

> -	  modify_expression (&lhs, false);

> -	  gimple_call_set_lhs (new_stmt, lhs);

> +	  tree *t = gimple_call_lhs_ptr (stmt);

> +	  modified |= modify_expression (t, false);

>  	}

> -      *stmt_p = new_stmt;

> -      return true;

> +      return modified;

>      }

>  

> -  /* Otherwise, no need to rebuild the statement, let's just modify arguments

> -     and the LHS if/as appropriate.  */

> -  bool modified = false;

> +  auto_vec<int, 16> index_map;

> +  auto_vec<pass_through_split_map, 4> pass_through_map;

> +  auto_vec<tree, 16> vargs;

> +  int always_copy_delta = 0;

> +  unsigned pt_idx = 0;

> +  int new_arg_idx = 0;

>    for (unsigned i = 0; i < nargs; i++)

>      {

> -      tree *t = gimple_call_arg_ptr (stmt, i);

> -      modified |= modify_expression (t, true);

> +      if (pt_idx < pass_through_args.length ()

> +	  && i == pass_through_args[pt_idx])

> +	{

> +	  unsigned j = pass_through_pbr_indices[pt_idx];

> +	  unsigned agg_arg_offset = pass_through_offsets[pt_idx];

> +	  pt_idx++;

> +	  always_copy_delta--;

> +	  tree base = m_replacements[j].base;

> +

> +	  /* In order to be put into SSA form, we have to push all replacements

> +	     pertaining to this parameter as parameters to the call statement.

> +	     Edge redirection will need to use edge summary to weed out the

> +	     unnecessary ones.  */

> +	  unsigned repl_list_len = m_replacements.length ();

> +	  for (; j < repl_list_len; j++)

> +	    {

> +	      if (m_replacements[j].base != base)

> +		break;

> +	      if (m_replacements[j].unit_offset < agg_arg_offset)

> +		continue;

> +	      pass_through_split_map pt_map;

> +	      pt_map.base_index = i;

> +	      pt_map.unit_offset

> +		= m_replacements[j].unit_offset - agg_arg_offset;

> +	      pt_map.new_index = new_arg_idx;

> +	      pass_through_map.safe_push (pt_map);

> +	      vargs.safe_push (m_replacements[j].repl);

> +	      new_arg_idx++;

> +	      always_copy_delta++;

> +	    }

> +	  index_map.safe_push (-1);

> +	}

> +      else

> +	{

> +	  tree t = gimple_call_arg (stmt, i);

> +	  modify_expression (&t, true);

> +	  vargs.safe_push (t);

> +	  index_map.safe_push (new_arg_idx);

> +	  new_arg_idx++;

> +	}

>      }

>  

> -  if (gimple_call_lhs (stmt))

> +  gcall *new_stmt = gimple_build_call_vec (gimple_call_fn (stmt), vargs);

> +  if (gimple_has_location (stmt))

> +    gimple_set_location (new_stmt, gimple_location (stmt));

> +  gimple_call_set_chain (new_stmt, gimple_call_chain (stmt));

> +  gimple_call_copy_flags (new_stmt, stmt);

> +  if (tree lhs = gimple_call_lhs (stmt))

>      {

> -      tree *t = gimple_call_lhs_ptr (stmt);

> -      modified |= modify_expression (t, false);

> +      modify_expression (&lhs, false);

> +      gimple_call_set_lhs (new_stmt, lhs);

>      }

> +  *stmt_p = new_stmt;

>  

> -  return modified;

> +  if (orig_stmt)

> +    record_argument_state (m_id, orig_stmt, index_map, pass_through_map,

> +			   always_copy_delta);

> +  return true;

>  }

>  

>  /* If the statement STMT contains any expressions that need to replaced with a

> @@ -1724,7 +1795,8 @@ ipa_param_body_adjustments::modify_call_stmt (gcall **stmt_p)

>  

>  bool

>  ipa_param_body_adjustments::modify_gimple_stmt (gimple **stmt,

> -						gimple_seq *extra_stmts)

> +						gimple_seq *extra_stmts,

> +						gimple *orig_stmt)

>  {

>    bool modified = false;

>    tree *t;

> @@ -1744,7 +1816,7 @@ ipa_param_body_adjustments::modify_gimple_stmt (gimple **stmt,

>        break;

>  

>      case GIMPLE_CALL:

> -      modified |= modify_call_stmt ((gcall **) stmt);

> +      modified |= modify_call_stmt ((gcall **) stmt, orig_stmt);

>        break;

>  

>      case GIMPLE_ASM:

> @@ -1801,7 +1873,7 @@ ipa_param_body_adjustments::modify_cfun_body ()

>  	  gimple *stmt = gsi_stmt (gsi);

>  	  gimple *stmt_copy = stmt;

>  	  gimple_seq extra_stmts = NULL;

> -	  bool modified = modify_gimple_stmt (&stmt, &extra_stmts);

> +	  bool modified = modify_gimple_stmt (&stmt, &extra_stmts, NULL);

>  	  if (stmt != stmt_copy)

>  	    {

>  	      gcc_checking_assert (modified);

> diff --git a/gcc/ipa-param-manipulation.h b/gcc/ipa-param-manipulation.h

> index c80e1bc5d6b..fd0df7b299c 100644

> --- a/gcc/ipa-param-manipulation.h

> +++ b/gcc/ipa-param-manipulation.h

> @@ -54,7 +54,7 @@ or only a vector of ipa_adjusted_params.

>  When these classes are used in the context of call graph clone materialization

>  and subsequent call statement redirection - which is the point at which we

>  modify arguments in call statements - they need to cooperate with each other in

> -order to handle what we refer to as transitive (IPA-SRA) splits.  These are

> +order to handle what we refer to as pass-through (IPA-SRA) splits.  These are

>  situations when a formal parameter of one function is split into several

>  smaller ones and some of them are then passed on in a call to another function

>  because the formal parameter of this callee has also been split.

> @@ -83,7 +83,7 @@ baz ()

>  Both bar and foo would have their parameter split.  Foo would receive one

>  replacement representing s.b.  Function bar would see its parameter split into

>  one replacement representing z.s.a and another representing z.s.b which would

> -be passed on to foo.  It would be a so called transitive split IPA-SRA

> +be passed on to foo.  It would be a so called pass-through split IPA-SRA

>  replacement, one which is passed in a call as an actual argument to another

>  IPA-SRA replacement in another function.

>  

> @@ -95,30 +95,25 @@ all of the above.

>  

>  Call redirection has to be able to find the right decl or SSA_NAME that

>  corresponds to the transitive split in the caller.  The SSA names are assigned

> -right after clone materialization/ modification and cannot be "added"

> -afterwards.  Moreover, if the caller has been inlined the SSA_NAMEs in question

> -no longer belong to PARM_DECLs but to VAR_DECLs, indistinguishable from any

> -others.

> +right after clone materialization/ modification and cannot be "added" to call

> +arguments at any later point.  Moreover, if the caller has been inlined the

> +SSA_NAMEs in question no longer belong to PARM_DECLs but to VAR_DECLs,

> +indistinguishable from any others.

>  

>  Therefore, when clone materialization finds a call statement which it knows is

> -a part of a transitive split, it will modify it into:

> +a part of a transitive split, it will simply add as arguments all new "split"

> +replacements (that have grater or equal offset than the original call

> +argument):

>  

> -  foo (DUMMY_Z_VAR.s, repl_for_a, repl_for_b, <rest of original arguments>);

> +  foo (repl_for_a, repl_for_b, <rest of original arguments>);

>  

> -It will also store {DUMMY_S_VAR, 32} and {DUMMY_S_VAR, 64} representing offsets

> -of z.s.a and z.s.b (assuming a 32-bit int) into foo's cgraph node

> -clone->performed_splits vector (which is storing structures of type

> -ipa_param_performed_split also defined in this header file).

> -

> -Call redirection will identify that expression DUMMY_Z_VAR.s is based on a

> -variable stored in performed_splits vector and learn that the following

> -arguments, already in SSA form, represent offsets 32 and 64 in a split original

> -parameter.  It subtracts offset of DUMMY_Z_VAR.s from 32 and 64 and arrives at

> -offsets 0 and 32 within callee's original parameter.  At this point it also

> -knows from the call graph that only the bit with offset 32 is needed and so

> -changes the call statement into final:

> -

> -bar (repl_for_b, <rest of original arguments>);  */

> +It will also store into ipa_edge_modification_info (which is internal to

> +ipa-param-modification.c) information about which replacement is which and

> +where original arguments are.  Call redirection will then invoke

> +ipa_param_adjustments::modify_call which will access this information and

> +eliminate all replacements which the callee does not expect (repl_for_a in our

> +example above).  In between these two steps, however, a call statement might

> +have extraneous arguments.  */

>  

>  #ifndef IPA_PARAM_MANIPULATION_H

>  #define IPA_PARAM_MANIPULATION_H

> @@ -207,21 +202,6 @@ struct GTY(()) ipa_adjusted_param

>  void ipa_dump_adjusted_parameters (FILE *f,

>  				   vec<ipa_adjusted_param, va_gc> *adj_params);

>  

> -/* Structure to remember the split performed on a node so that edge redirection

> -   (i.e. splitting arguments of call statements) know how split formal

> -   parameters of the caller are represented.  */

> -

> -struct GTY(()) ipa_param_performed_split

> -{

> -  /* The dummy VAR_DECL that was created instead of the split parameter that

> -     sits in the call in the meantime between clone materialization and call

> -     redirection.  All entries in a vector of performed splits that correspond

> -     to the same dumy decl must be grouped together.  */

> -  tree dummy_decl;

> -  /* Offset into the original parameter.  */

> -  unsigned unit_offset;

> -};

> -

>  /* Class used to record planned modifications to parameters of a function and

>     also to perform necessary modifications at the caller side at the gimple

>     level.  Used to describe all cgraph node clones that have their parameters

> @@ -244,9 +224,7 @@ public:

>  

>    /* Modify a call statement arguments (and possibly remove the return value)

>       as described in the data fields of this class.  */

> -  gcall *modify_call (gcall *stmt,

> -		      vec<ipa_param_performed_split, va_gc> *performed_splits,

> -		      tree callee_decl, bool update_references);

> +  gcall *modify_call (cgraph_edge *cs, bool update_references);

>    /* Return if the first parameter is left intact.  */

>    bool first_param_intact_p ();

>    /* Build a function type corresponding to the modified call.  */

> @@ -293,15 +271,9 @@ struct ipa_param_body_replacement

>    tree base;

>    /* The new decl it should be replaced with.  */

>    tree repl;

> -  /* When modifying clones during IPA clone materialization, this is a dummy

> -     decl used to mark calls in which we need to apply transitive splitting,

> -     these dummy delcls are inserted as arguments to such calls and then

> -     followed by all the replacements with offset info stored in

> -     ipa_param_performed_split.

> -

> -     Users of ipa_param_body_adjustments that modify standalone functions

> -     outside of IPA clone materialization can use this field for their internal

> -     purposes.  */

> +  /* Users of ipa_param_body_adjustments that modify standalone functions

> +     outside of IPA clone materialization can use the following field for their

> +     internal purposes.  */

>    tree dummy;

>    /* The offset within BASE that REPL represents.  */

>    unsigned unit_offset;

> @@ -342,8 +314,7 @@ public:

>    /* Change the PARM_DECLs.  */

>    void modify_formal_parameters ();

>    /* Register a replacement decl for the transformation done in APM.  */

> -  void register_replacement (ipa_adjusted_param *apm, tree replacement,

> -			     tree dummy = NULL_TREE);

> +  void register_replacement (ipa_adjusted_param *apm, tree replacement);

>    /* Lookup a replacement for a given offset within a given parameter.  */

>    tree lookup_replacement (tree base, unsigned unit_offset);

>    /* Lookup a replacement for an expression, if there is one.  */

> @@ -353,7 +324,8 @@ public:

>       parameter. */

>    tree get_replacement_ssa_base (tree old_decl);

>    /* Modify a statement.  */

> -  bool modify_gimple_stmt (gimple **stmt, gimple_seq *extra_stmts);

> +  bool modify_gimple_stmt (gimple **stmt, gimple_seq *extra_stmts,

> +			   gimple *orig_stmt);

>    /* Return the new chain of parameters.  */

>    tree get_new_param_chain ();

>  

> @@ -380,9 +352,10 @@ private:

>    tree replace_removed_params_ssa_names (tree old_name, gimple *stmt);

>    bool modify_expression (tree *expr_p, bool convert);

>    bool modify_assignment (gimple *stmt, gimple_seq *extra_stmts);

> -  bool modify_call_stmt (gcall **stmt_p);

> +  bool modify_call_stmt (gcall **stmt_p, gimple *orig_stmt);

>    bool modify_cfun_body ();

>    void reset_debug_stmts ();

> +  void mark_dead_statements (tree dead_param);

>  

>    /* Declaration of the function that is being transformed.  */

>  

> @@ -431,5 +404,7 @@ private:

>  

>  void push_function_arg_decls (vec<tree> *args, tree fndecl);

>  void push_function_arg_types (vec<tree> *types, tree fntype);

> +void ipa_verify_edge_has_no_modifications (cgraph_edge *cs);

> +

>  

>  #endif	/* IPA_PARAM_MANIPULATION_H */

> diff --git a/gcc/symtab-clones.h b/gcc/symtab-clones.h

> index 5695a434f6a..a6ad4a6e27f 100644

> --- a/gcc/symtab-clones.h

> +++ b/gcc/symtab-clones.h

> @@ -26,8 +26,7 @@ struct GTY(()) clone_info

>    /* Constructor.  */

>    clone_info ()

>      : tree_map (NULL),

> -      param_adjustments (NULL),

> -      performed_splits (NULL)

> +      param_adjustments (NULL)

>    {

>    }

>    /* Constants discovered by IPA-CP, i.e. which parameter should be replaced

> @@ -35,18 +34,6 @@ struct GTY(()) clone_info

>    vec<ipa_replace_map *, va_gc> *tree_map;

>    /* Parameter modification that IPA-SRA decided to perform.  */

>    ipa_param_adjustments *param_adjustments;

> -  /* Lists of dummy-decl and offset pairs representing split formal parameters

> -     in the caller.  Offsets of all new replacements are enumerated, those

> -     coming from the same original parameter have the same dummy decl stored

> -     along with them.

> -

> -     Dummy decls sit in call statement arguments followed by new parameter

> -     decls (or their SSA names) in between (caller) clone materialization and

> -     call redirection.  Redirection then recognizes the dummy variable and

> -     together with the stored offsets can reconstruct what exactly the new

> -     parameter decls represent and can leave in place only those that the

> -     callee expects.  */

> -  vec<ipa_param_performed_split, va_gc> *performed_splits;

>  

>    /* Return clone_info, if available.  */

>    static clone_info *get (cgraph_node *node);

> diff --git a/gcc/tree-inline.c b/gcc/tree-inline.c

> index 8f945b88c12..e2fb6be681c 100644

> --- a/gcc/tree-inline.c

> +++ b/gcc/tree-inline.c

> @@ -1900,7 +1900,7 @@ remap_gimple_stmt (gimple *stmt, copy_body_data *id)

>    if (id->param_body_adjs)

>      {

>        gimple_seq extra_stmts = NULL;

> -      id->param_body_adjs->modify_gimple_stmt (&copy, &extra_stmts);

> +      id->param_body_adjs->modify_gimple_stmt (&copy, &extra_stmts, stmt);

>        if (!gimple_seq_empty_p (extra_stmts))

>  	{

>  	  memset (&wi, 0, sizeof (wi));

> @@ -4721,7 +4721,6 @@ expand_call_inline (basic_block bb, gimple *stmt, copy_body_data *id,

>    use_operand_p use;

>    gimple *simtenter_stmt = NULL;

>    vec<tree> *simtvars_save;

> -  clone_info *info;

>  

>    /* The gimplifier uses input_location in too many places, such as

>       internal_get_tmp_var ().  */

> @@ -5046,40 +5045,6 @@ expand_call_inline (basic_block bb, gimple *stmt, copy_body_data *id,

>    /* Add local vars in this inlined callee to caller.  */

>    add_local_variables (id->src_cfun, cfun, id);

>  

> -  info = clone_info::get (id->src_node);

> -  if (info && info->performed_splits)

> -    {

> -      clone_info *dst_info = clone_info::get_create (id->dst_node);

> -      /* Any calls from the inlined function will be turned into calls from the

> -	 function we inline into.  We must preserve notes about how to split

> -	 parameters such calls should be redirected/updated.  */

> -      unsigned len = vec_safe_length (info->performed_splits);

> -      for (unsigned i = 0; i < len; i++)

> -	{

> -	  ipa_param_performed_split ps

> -	    = (*info->performed_splits)[i];

> -	  ps.dummy_decl = remap_decl (ps.dummy_decl, id);

> -	  vec_safe_push (dst_info->performed_splits, ps);

> -	}

> -

> -      if (flag_checking)

> -	{

> -	  len = vec_safe_length (dst_info->performed_splits);

> -	  for (unsigned i = 0; i < len; i++)

> -	    {

> -	      ipa_param_performed_split *ps1

> -		= &(*dst_info->performed_splits)[i];

> -	      for (unsigned j = i + 1; j < len; j++)

> -		{

> -		  ipa_param_performed_split *ps2

> -		    = &(*dst_info->performed_splits)[j];

> -		  gcc_assert (ps1->dummy_decl != ps2->dummy_decl

> -			      || ps1->unit_offset != ps2->unit_offset);

> -		}

> -	    }

> -	}

> -    }

> -

>    if (dump_enabled_p ())

>      {

>        char buf[128];

> @@ -6103,23 +6068,10 @@ tree_versionable_function_p (tree fndecl)

>  static void

>  update_clone_info (copy_body_data * id)

>  {

> -  clone_info *dst_info = clone_info::get (id->dst_node);

> -  vec<ipa_param_performed_split, va_gc> *cur_performed_splits

> -    = dst_info ? dst_info->performed_splits : NULL;

> -  if (cur_performed_splits)

> -    {

> -      unsigned len = cur_performed_splits->length ();

> -      for (unsigned i = 0; i < len; i++)

> -	{

> -	  ipa_param_performed_split *ps = &(*cur_performed_splits)[i];

> -	  ps->dummy_decl = remap_decl (ps->dummy_decl, id);

> -	}

> -    }

> -

> -  struct cgraph_node *node;

> -  if (!id->dst_node->clones)

> +  struct cgraph_node *this_node = id->dst_node;

> +  if (!this_node->clones)

>      return;

> -  for (node = id->dst_node->clones; node != id->dst_node;)

> +  for (cgraph_node *node = this_node->clones; node != this_node;)

>      {

>        /* First update replace maps to match the new body.  */

>        clone_info *info = clone_info::get (node);

> @@ -6133,53 +6085,6 @@ update_clone_info (copy_body_data * id)

>  	      walk_tree (&replace_info->new_tree, copy_tree_body_r, id, NULL);

>  	    }

>  	}

> -      if (info && info->performed_splits)

> -	{

> -	  unsigned len = vec_safe_length (info->performed_splits);

> -	  for (unsigned i = 0; i < len; i++)

> -	    {

> -	      ipa_param_performed_split *ps

> -		= &(*info->performed_splits)[i];

> -	      ps->dummy_decl = remap_decl (ps->dummy_decl, id);

> -	    }

> -	}

> -      if (unsigned len = vec_safe_length (cur_performed_splits))

> -	{

> -	  /* We do not want to add current performed splits when we are saving

> -	     a copy of function body for later during inlining, that would just

> -	     duplicate all entries.  So let's have a look whether anything

> -	     referring to the first dummy_decl is present.  */

> -	  if (!info)

> -	    info = clone_info::get_create (node);

> -	  unsigned dst_len = vec_safe_length (info->performed_splits);

> -	  ipa_param_performed_split *first = &(*cur_performed_splits)[0];

> -	  for (unsigned i = 0; i < dst_len; i++)

> -	    if ((*info->performed_splits)[i].dummy_decl

> -		== first->dummy_decl)

> -	      {

> -		len = 0;

> -		break;

> -	      }

> -

> -	  for (unsigned i = 0; i < len; i++)

> -	    vec_safe_push (info->performed_splits,

> -			   (*cur_performed_splits)[i]);

> -	  if (flag_checking)

> -	    {

> -	      for (unsigned i = 0; i < dst_len; i++)

> -		{

> -		  ipa_param_performed_split *ps1

> -		    = &(*info->performed_splits)[i];

> -		  for (unsigned j = i + 1; j < dst_len; j++)

> -		    {

> -		      ipa_param_performed_split *ps2

> -			= &(*info->performed_splits)[j];

> -		      gcc_assert (ps1->dummy_decl != ps2->dummy_decl

> -				  || ps1->unit_offset != ps2->unit_offset);

> -		    }

> -		}

> -	    }

> -	}

>  

>        if (node->clones)

>  	node = node->clones;

> -- 

> 2.31.1
Martin Jambor May 21, 2021, 4:08 p.m. | #6
Hi,

On Tue, May 11 2021, Richard Biener wrote:
> On Mon, May 10, 2021 at 8:52 PM Martin Jambor <mjambor@suse.cz> wrote:


[...]

>> @@ -969,6 +969,97 @@ ipa_param_body_adjustments::carry_over_param (tree t)

>>    return new_parm;

>>  }

>>

>> +/* Return true if BLOCKS_TO_COPY is NULL or if PHI has an argument ARG in

>> +   position that corresponds to an edge that is coming from a block that has

>> +   the corresponding bit set in BLOCKS_TO_COPY.  */

>> +

>> +static bool

>> +phi_arg_will_live_p (gphi *phi, bitmap blocks_to_copy, tree arg)

>> +{

>> +  bool arg_will_survive = false;

>> +  if (!blocks_to_copy)

>> +    arg_will_survive = true;

>> +  else

>> +    for (unsigned i = 0; i < gimple_phi_num_args (phi); i++)

>> +      if (gimple_phi_arg_def (phi, i) == arg

>

> I think this is prone to quadratic, it would be nice to use the

> faster FOR_EACH_IMM_USE_FAST () below and then

> phi_arg_index_from_use () to get to the corresponding edge

> directly - this would remove the loop over PHI args here and

> you can then inline the function below.


I see, thanks, I have changed the code as suggested.

>

>> +         && bitmap_bit_p (blocks_to_copy,

>> +                          gimple_phi_arg_edge (phi, i)->src->index))

>> +       {

>> +         arg_will_survive = true;

>> +         break;

>> +       }

>> +  return arg_will_survive;

>> +}

>> +

>> +/* Populate m_dead_stmts given that DEAD_PARAM is going to be removed without

>> +   any replacement or splitting.  REPL is the replacement VAR_SECL to base any

>> +   remaining uses of a removed parameter on.  */

>> +

>> +void

>> +ipa_param_body_adjustments::mark_dead_statements (tree dead_param)

>> +{

>> +  /* Current IPA analyses which remove unused parameters never remove a

>> +     non-gimple register ones which have any use except as parameters in other

>> +     calls, so we can safely leve them as they are.  */

>> +  if (!is_gimple_reg (dead_param))

>> +    return;

>> +  tree parm_ddef = ssa_default_def (m_id->src_cfun, dead_param);

>> +  if (!parm_ddef || has_zero_uses (parm_ddef))

>> +    return;

>> +

>> +  auto_vec<tree, 4> stack;

>> +  m_dead_ssas.add (parm_ddef);

>> +  stack.safe_push (parm_ddef);

>> +  while (!stack.is_empty ())

>> +    {

>> +      tree t = stack.pop ();

>> +

>> +      imm_use_iterator imm_iter;

>> +      gimple *stmt;

>> +

>> +      insert_decl_map (m_id, t, error_mark_node);

>> +      FOR_EACH_IMM_USE_STMT (stmt, imm_iter, t)

>> +       {

>> +         if (is_gimple_call (stmt)

>

> (*) so we just ignore dead calls?  That is, there might be

> a const call like

>

>    _1 = foo (removed_param_2);

>

> and followup important to be removed uses of _1?  Above

> you say that eventual IPA SRA argument removal is dealt

> with but this still leaves the const/pure call case.  Unless

> IPA SRA bails on them, of course.


It does, dealing with pure/const functions is only a TODO.  This code is
basically only meant to understand what isra_track_scalar_value_uses
can.  I was looking at somehow merging them but introducing
callbacks/specialization would make it too complex and ugly for little
gain.


> Can you add a comment like

>

> /* IPA SRA only handles dead arguments in calls when it

>    removes those arguments from the called function.  The

>    IPA machinery arranges for fixup here.  */


I added the following comment which I think better describes the
situation:

/* Calls containing dead arguments cannot be deleted,
   modify_call_stmt will instead remove just the argument later on. 
   If isra_track_scalar_value_uses in ipa-sra.c is extended to look 
   through const functions, we will need to do so here too.  */ 

because arguments are indeed "usually" removed during the final fixup of
calls but this case is actually an exception from that "rule."

>

>> +             || (m_id->blocks_to_copy

>> +                 && !bitmap_bit_p (m_id->blocks_to_copy,

>> +                                   gimple_bb (stmt)->index)))

>> +           continue;

>> +

>> +         if (is_gimple_debug (stmt))

>> +           {

>> +             m_dead_stmts.add (stmt);

>> +             gcc_assert (gimple_debug_bind_p (stmt));

>> +           }

>> +         else if (gimple_code (stmt) == GIMPLE_PHI)

>> +           {

>> +             gphi *phi = as_a <gphi *> (stmt);

>> +             if (phi_arg_will_live_p (phi, m_id->blocks_to_copy, t))

>> +               {

>> +                 m_dead_stmts.add (phi);

>> +                 tree res = gimple_phi_result (phi);

>> +                 if (!m_dead_ssas.add (res))

>> +                   stack.safe_push (res);

>> +               }

>> +           }

>> +         else if (is_gimple_assign (stmt))

>> +           {

>> +             m_dead_stmts.add (stmt);

>> +             if (!gimple_clobber_p (stmt))

>> +               {

>> +                 tree lhs = gimple_assign_lhs (stmt);

>> +                 gcc_assert (TREE_CODE (lhs) == SSA_NAME);

>

> I don't think you can assert this?  Well, maybe you can because

> IPA prop would have refused to mark the param dead?  I'm

> thinking about stores here.  I'd have leaned towards instead

> guarding the m_dead_ssas.add with TREE_CODE (lhs) == SSA_NAME

> but this then leaves possibly "dead" code around when it is not

> an SSA name.


Again, the code is supposed to isra_track_scalar_value_uses.  If the
parameter is stored into memory, then IPA-SRA basically looses track of
it and so asserting here is the right thing to do.

>

>> +                 if (!m_dead_ssas.add (lhs))

>> +                   stack.safe_push (lhs);

>> +               }

>> +           }

>> +         else

>> +           /* IPA-SRA does not analyze other types of statements.  */

>> +           gcc_unreachable ();

>

> So I guess fine in this light.  But (*) above.

>

> Otherwise looks OK to me.

>


Thank you very much, I understand that the code is not easy to review.

I have re-posted also the first (split) patch and have been extensively
reminding Honza to look at it so hopefully he will and then I'll commit
both.

Thanks again,

Martin



I was asked by Richi to split my fix for PR 93385 for easier review
into IPA-SRA materialization refactoring and the actual DCE addition.
This is the second part that actually contains the DCE of statements
that IPA-SRA should not leave behind because they can have problematic
side effects, even if they are useless, so that we do not depend on
tree-dce to remove them for correctness.

The patch fixes the problem by doing a def-use walk when materializing
clones, marking which statements should not be copied and which
SSA_NAMEs do not need to be computed because eventually they would be
DCEd.  We do this on the original function body and tree-inline simply
does not copy statements which are "dead."

The only complication is removing dead argument calls because that
needs to be communicated to callee redirection code using the
infrastructure introduced by the previous patch.

I added all testcases of the original patch to this one, although some
probably test behavior introduced in the previous patch.

gcc/ChangeLog:

2021-05-17  Martin Jambor  <mjambor@suse.cz>

	PR ipa/93385
	* ipa-param-manipulation.h (class ipa_param_body_adjustments): New
	members m_dead_stmts and m_dead_ssas.
	* ipa-param-manipulation.c
	(ipa_param_body_adjustments::mark_dead_statements): New function.
	(ipa_param_body_adjustments::common_initialization): Call it on
	all removed but not split parameters.
	(ipa_param_body_adjustments::ipa_param_body_adjustments): Initialize
	new mwmbers.
	(ipa_param_body_adjustments::modify_call_stmt): Remove arguments that
	are dead.
	* tree-inline.c (remap_gimple_stmt): Do not copy dead statements, reset
	dead debug statements.
	(copy_phis_for_bb): Do not copy dead PHI nodes.

gcc/testsuite/ChangeLog:

2021-03-22  Martin Jambor  <mjambor@suse.cz>

	PR ipa/93385
	* gcc.dg/ipa/pr93385.c: New test.
	* gcc.dg/ipa/ipa-sra-23.c: Likewise.
	* gcc.dg/ipa/ipa-sra-24.c: Likewise.
	* g++.dg/ipa/ipa-sra-4.C: Likewise.
---
 gcc/ipa-param-manipulation.c          | 129 +++++++++++++++++++++++---
 gcc/ipa-param-manipulation.h          |   6 ++
 gcc/testsuite/g++.dg/ipa/ipa-sra-4.C  |  37 ++++++++
 gcc/testsuite/gcc.dg/ipa/ipa-sra-23.c |  24 +++++
 gcc/testsuite/gcc.dg/ipa/ipa-sra-24.c |  20 ++++
 gcc/testsuite/gcc.dg/ipa/pr93385.c    |  27 ++++++
 gcc/tree-inline.c                     |  18 +++-
 7 files changed, 243 insertions(+), 18 deletions(-)
 create mode 100644 gcc/testsuite/g++.dg/ipa/ipa-sra-4.C
 create mode 100644 gcc/testsuite/gcc.dg/ipa/ipa-sra-23.c
 create mode 100644 gcc/testsuite/gcc.dg/ipa/ipa-sra-24.c
 create mode 100644 gcc/testsuite/gcc.dg/ipa/pr93385.c

diff --git a/gcc/ipa-param-manipulation.c b/gcc/ipa-param-manipulation.c
index 6a423391d2f..26b02d7aa95 100644
--- a/gcc/ipa-param-manipulation.c
+++ b/gcc/ipa-param-manipulation.c
@@ -970,6 +970,84 @@ ipa_param_body_adjustments::carry_over_param (tree t)
   return new_parm;
 }
 
+/* Populate m_dead_stmts given that DEAD_PARAM is going to be removed without
+   any replacement or splitting.  REPL is the replacement VAR_SECL to base any
+   remaining uses of a removed parameter on.  */
+
+void
+ipa_param_body_adjustments::mark_dead_statements (tree dead_param)
+{
+  /* Current IPA analyses which remove unused parameters never remove a
+     non-gimple register ones which have any use except as parameters in other
+     calls, so we can safely leve them as they are.  */
+  if (!is_gimple_reg (dead_param))
+    return;
+  tree parm_ddef = ssa_default_def (m_id->src_cfun, dead_param);
+  if (!parm_ddef || has_zero_uses (parm_ddef))
+    return;
+
+  auto_vec<tree, 4> stack;
+  m_dead_ssas.add (parm_ddef);
+  stack.safe_push (parm_ddef);
+  while (!stack.is_empty ())
+    {
+      imm_use_iterator imm_iter;
+      use_operand_p use_p;
+      tree t = stack.pop ();
+
+      insert_decl_map (m_id, t, error_mark_node);
+      FOR_EACH_IMM_USE_FAST (use_p, imm_iter, t)
+	{
+	  gimple *stmt = USE_STMT (use_p);
+
+	  /* Calls containing dead arguments cannot be deleted,
+	     modify_call_stmt will instead remove just the argument later on.
+	     If isra_track_scalar_value_uses in ipa-sra.c is extended to look
+	     through const functions, we will need to do so here too.  */
+	  if (is_gimple_call (stmt)
+	      || (m_id->blocks_to_copy
+		  && !bitmap_bit_p (m_id->blocks_to_copy,
+				    gimple_bb (stmt)->index)))
+	    continue;
+
+	  if (is_gimple_debug (stmt))
+	    {
+	      m_dead_stmts.add (stmt);
+	      gcc_assert (gimple_debug_bind_p (stmt));
+	    }
+	  else if (gimple_code (stmt) == GIMPLE_PHI)
+	    {
+	      gphi *phi = as_a <gphi *> (stmt);
+	      int ix = PHI_ARG_INDEX_FROM_USE (use_p);
+
+	      if (!m_id->blocks_to_copy
+		  || bitmap_bit_p (m_id->blocks_to_copy,
+				   gimple_phi_arg_edge (phi, ix)->src->index))
+		{
+		  m_dead_stmts.add (phi);
+		  tree res = gimple_phi_result (phi);
+		  if (!m_dead_ssas.add (res))
+		    stack.safe_push (res);
+		}
+	    }
+	  else if (is_gimple_assign (stmt))
+	    {
+	      m_dead_stmts.add (stmt);
+	      if (!gimple_clobber_p (stmt))
+		{
+		  tree lhs = gimple_assign_lhs (stmt);
+		  gcc_assert (TREE_CODE (lhs) == SSA_NAME);
+		  if (!m_dead_ssas.add (lhs))
+		    stack.safe_push (lhs);
+		}
+	    }
+	  else
+	    /* IPA-SRA does not analyze other types of statements.  */
+	    gcc_unreachable ();
+	}
+    }
+}
+
 /* Common initialization performed by all ipa_param_body_adjustments
    constructors.  OLD_FNDECL is the declaration we take original arguments
    from, (it may be the same as M_FNDECL).  VARS, if non-NULL, is a pointer to
@@ -1003,6 +1081,9 @@ ipa_param_body_adjustments::common_initialization (tree old_fndecl,
   auto_vec<bool, 16> kept;
   kept.reserve_exact (m_oparms.length ());
   kept.quick_grow_cleared (m_oparms.length ());
+  auto_vec<bool, 16> split;
+  split.reserve_exact (m_oparms.length ());
+  split.quick_grow_cleared (m_oparms.length ());
 
   unsigned adj_len = vec_safe_length (m_adj_params);
   m_method2func = ((TREE_CODE (TREE_TYPE (m_fndecl)) == METHOD_TYPE)
@@ -1048,6 +1129,7 @@ ipa_param_body_adjustments::common_initialization (tree old_fndecl,
 	  if (apm->op == IPA_PARAM_OP_SPLIT)
 	    {
 	      m_split_modifications_p = true;
+	      split[prev_index] = true;
 	      register_replacement (apm, new_parm);
 	    }
         }
@@ -1080,6 +1162,11 @@ ipa_param_body_adjustments::common_initialization (tree old_fndecl,
 		/* Declare this new variable.  */
 		DECL_CHAIN (var) = *vars;
 		*vars = var;
+
+		/* If this is not a split but a real removal, init hash sets
+		   that will guide what not to copy to the new body.  */
+		if (!split[i])
+		  mark_dead_statements (m_oparms[i]);
 	      }
 	  }
 	else
@@ -1136,9 +1223,10 @@ ipa_param_body_adjustments
 ::ipa_param_body_adjustments (vec<ipa_adjusted_param, va_gc> *adj_params,
 			      tree fndecl)
   : m_adj_params (adj_params), m_adjustments (NULL), m_reset_debug_decls (),
-    m_split_modifications_p (false), m_fndecl (fndecl), m_id (NULL),
-    m_oparms (), m_new_decls (), m_new_types (), m_replacements (),
-    m_removed_decls (), m_removed_map (), m_method2func (false)
+    m_split_modifications_p (false), m_dead_stmts (), m_dead_ssas (),
+    m_fndecl (fndecl), m_id (NULL), m_oparms (), m_new_decls (),
+    m_new_types (), m_replacements (), m_removed_decls (), m_removed_map (),
+    m_method2func (false)
 {
   common_initialization (fndecl, NULL, NULL);
 }
@@ -1152,9 +1240,9 @@ ipa_param_body_adjustments
 ::ipa_param_body_adjustments (ipa_param_adjustments *adjustments,
 			      tree fndecl)
   : m_adj_params (adjustments->m_adj_params), m_adjustments (adjustments),
-    m_reset_debug_decls (), m_split_modifications_p (false), m_fndecl (fndecl),
-    m_id (NULL), m_oparms (), m_new_decls (), m_new_types (),
-    m_replacements (), m_removed_decls (), m_removed_map (),
+    m_reset_debug_decls (), m_split_modifications_p (false), m_dead_stmts (),
+    m_dead_ssas (), m_fndecl (fndecl), m_id (NULL), m_oparms (), m_new_decls (),
+    m_new_types (), m_replacements (), m_removed_decls (), m_removed_map (),
     m_method2func (false)
 {
   common_initialization (fndecl, NULL, NULL);
@@ -1175,9 +1263,10 @@ ipa_param_body_adjustments
 			      copy_body_data *id, tree *vars,
 			      vec<ipa_replace_map *, va_gc> *tree_map)
   : m_adj_params (adjustments->m_adj_params), m_adjustments (adjustments),
-    m_reset_debug_decls (), m_split_modifications_p (false), m_fndecl (fndecl),
-    m_id (id), m_oparms (), m_new_decls (), m_new_types (), m_replacements (),
-    m_removed_decls (), m_removed_map (), m_method2func (false)
+    m_reset_debug_decls (), m_split_modifications_p (false), m_dead_stmts (),
+    m_dead_ssas (),m_fndecl (fndecl), m_id (id), m_oparms (), m_new_decls (),
+    m_new_types (), m_replacements (), m_removed_decls (), m_removed_map (),
+    m_method2func (false)
 {
   common_initialization (old_fndecl, vars, tree_map);
 }
@@ -1624,8 +1713,9 @@ ipa_param_body_adjustments::modify_call_stmt (gcall **stmt_p,
 		  && TREE_CODE (t) != IMAGPART_EXPR
 		  && TREE_CODE (t) != REALPART_EXPR);
 
-      /* The follow-up patch will check whether t needs to be removed, that's
-	 why this condition is in the loop.  */
+      if (TREE_CODE (t) == SSA_NAME
+	  && m_dead_ssas.contains (t))
+	recreate = true;
 
       if (!m_split_modifications_p)
 	continue;
@@ -1763,10 +1853,19 @@ ipa_param_body_adjustments::modify_call_stmt (gcall **stmt_p,
       else
 	{
 	  tree t = gimple_call_arg (stmt, i);
-	  modify_expression (&t, true);
-	  vargs.safe_push (t);
-	  index_map.safe_push (new_arg_idx);
-	  new_arg_idx++;
+	  if (TREE_CODE (t) == SSA_NAME
+	      && m_dead_ssas.contains (t))
+	    {
+	      always_copy_delta--;
+	      index_map.safe_push (-1);
+	    }
+	  else
+	    {
+	      modify_expression (&t, true);
+	      vargs.safe_push (t);
+	      index_map.safe_push (new_arg_idx);
+	      new_arg_idx++;
+	    }
 	}
     }
 
diff --git a/gcc/ipa-param-manipulation.h b/gcc/ipa-param-manipulation.h
index 31dcc4b9768..afcbc09bf33 100644
--- a/gcc/ipa-param-manipulation.h
+++ b/gcc/ipa-param-manipulation.h
@@ -342,6 +342,12 @@ public:
   /* Set to true if there are any IPA_PARAM_OP_SPLIT adjustments among stored
      adjustments.  */
   bool m_split_modifications_p;
+
+  /* Sets of statements and SSA_NAMEs that only manipulate data from parameters
+     removed because they are not necessary.  */
+  hash_set<gimple *> m_dead_stmts;
+  hash_set<tree> m_dead_ssas;
+
 private:
   void common_initialization (tree old_fndecl, tree *vars,
 			      vec<ipa_replace_map *, va_gc> *tree_map);
diff --git a/gcc/testsuite/g++.dg/ipa/ipa-sra-4.C b/gcc/testsuite/g++.dg/ipa/ipa-sra-4.C
new file mode 100644
index 00000000000..56d59f9fd9a
--- /dev/null
+++ b/gcc/testsuite/g++.dg/ipa/ipa-sra-4.C
@@ -0,0 +1,37 @@
+/* { dg-do compile { target c++11 } } */
+/* { dg-options "-O2 -fipa-sra"  } */
+
+void __throw_bad_alloc() __attribute__((__noreturn__));
+void __throw_bad_array_new_length();
+template <typename> class allocator {};
+template <typename> struct allocator_traits;
+int *allocate___trans_tmp_2;
+template <typename _Tp> struct allocator_traits<allocator<_Tp>> {
+  using allocator_type = allocator<_Tp>;
+  using pointer = _Tp *;
+  using size_type = long;
+  static pointer allocate(allocator_type &, size_type __n) {
+    long __trans_tmp_3 = __n;
+    if (__builtin_expect(__trans_tmp_3, false))
+      if (__trans_tmp_3)
+        __throw_bad_array_new_length();
+    operator new(sizeof(int));
+    return allocate___trans_tmp_2;
+  }
+};
+class throw_allocator_base {
+  allocator<int> _M_allocator;
+public:
+  int *allocate(long __n) {
+    if (__n)
+      __throw_bad_alloc();
+    int *a = allocator_traits<allocator<int>>::allocate(_M_allocator, __n);
+    return a;
+  }
+};
+template <typename Alloc> void check_allocate_max_size() {
+  Alloc a;
+  long __trans_tmp_1 = 0;
+  a.allocate(__trans_tmp_1 + 1);
+}
+int main() { check_allocate_max_size<throw_allocator_base>(); }
diff --git a/gcc/testsuite/gcc.dg/ipa/ipa-sra-23.c b/gcc/testsuite/gcc.dg/ipa/ipa-sra-23.c
new file mode 100644
index 00000000000..f438b509614
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/ipa/ipa-sra-23.c
@@ -0,0 +1,24 @@
+/* { dg-do compile } */
+/* { dg-options "-O2"  } */
+
+extern int g;
+
+static int __attribute__((noinline))
+bar (int i, int j)
+{
+  return 2*g + i;
+}
+
+static int __attribute__((noinline))
+foo (int i, int j)
+{
+  if (i > 5)
+    j = 22;
+  return bar (i, j) + 1;
+}
+
+int
+entry (int l, int k)
+{
+  return foo (l, k);
+}
diff --git a/gcc/testsuite/gcc.dg/ipa/ipa-sra-24.c b/gcc/testsuite/gcc.dg/ipa/ipa-sra-24.c
new file mode 100644
index 00000000000..7b5bf0825fc
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/ipa/ipa-sra-24.c
@@ -0,0 +1,20 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -Wmaybe-uninitialized -Werror"  } */
+
+int *ttmp_1;
+_Bool pt_ins_tipdo, pq_ins_apd, pq_ins_tt2;
+int gtrphdt;
+
+void pl_ins(int, _Bool, _Bool);
+inline void pt_ins(int *, _Bool apdo) {
+  int list = *ttmp_1;
+  pl_ins(list, apdo, pt_ins_tipdo);
+}
+void pq_ins(int *t) {
+  if (pq_ins_tt2)
+    pt_ins(t, pq_ins_apd);
+}
+int gtr_post_hd() {
+  pq_ins(&gtrphdt);
+  return 0;
+}
diff --git a/gcc/testsuite/gcc.dg/ipa/pr93385.c b/gcc/testsuite/gcc.dg/ipa/pr93385.c
new file mode 100644
index 00000000000..6d1d0d7cd27
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/ipa/pr93385.c
@@ -0,0 +1,27 @@
+/* { dg-do run } */
+/* { dg-options "-O2 -fno-dce -fno-ipa-cp -fno-tree-dce" } */
+
+char a, b;
+
+#ifdef __SIZEOF_INT128__
+#define T unsigned __int128
+#else
+#define T unsigned
+#endif
+
+static inline int
+c (T d)
+{
+  char e = 0;
+  d %= (unsigned) d;
+  e -= 0;
+  __builtin_strncpy (&a, &e, 1);
+  return e + b;
+}
+
+int
+main (void)
+{
+  c (~0);
+  return 0;
+}
diff --git a/gcc/tree-inline.c b/gcc/tree-inline.c
index e2fb6be681c..cad11eeae17 100644
--- a/gcc/tree-inline.c
+++ b/gcc/tree-inline.c
@@ -1504,6 +1504,11 @@ remap_gimple_stmt (gimple *stmt, copy_body_data *id)
 	  : !opt_for_fn (id->dst_fn, flag_var_tracking_assignments)))
     return NULL;
 
+  if (!is_gimple_debug (stmt)
+      && id->param_body_adjs
+      && id->param_body_adjs->m_dead_stmts.contains (stmt))
+    return NULL;
+
   /* Begin by recognizing trees that we'll completely rewrite for the
      inlining context.  Our output for these trees is completely
      different from our input (e.g. RETURN_EXPR is deleted and morphs
@@ -1768,10 +1773,15 @@ remap_gimple_stmt (gimple *stmt, copy_body_data *id)
 
       if (gimple_debug_bind_p (stmt))
 	{
+	  tree value;
+	  if (id->param_body_adjs
+	      && id->param_body_adjs->m_dead_stmts.contains (stmt))
+	    value = NULL_TREE;
+	  else
+	    value = gimple_debug_bind_get_value (stmt);
 	  gdebug *copy
 	    = gimple_build_debug_bind (gimple_debug_bind_get_var (stmt),
-				       gimple_debug_bind_get_value (stmt),
-				       stmt);
+				       value, stmt);
 	  if (id->reset_location)
 	    gimple_set_location (copy, input_location);
 	  id->debug_stmts.safe_push (copy);
@@ -2650,7 +2660,9 @@ copy_phis_for_bb (basic_block bb, copy_body_data *id)
       phi = si.phi ();
       res = PHI_RESULT (phi);
       new_res = res;
-      if (!virtual_operand_p (res))
+      if (!virtual_operand_p (res)
+	  && (!id->param_body_adjs
+	      || !id->param_body_adjs->m_dead_stmts.contains (phi)))
 	{
 	  walk_tree (&new_res, copy_tree_body_r, id, NULL);
 	  if (EDGE_COUNT (new_bb->preds) == 0)
-- 
2.31.1
Martin Jambor June 9, 2021, 12:20 p.m. | #7
Hi Honza,

I'd like to ping this patch.  I know it is big but I do believe it makes
the management of information passed from clone materialization to edge
redirection much more straightforward.  And I need it to fix PR 93385
with a follow-up that has already been approved by Richi.

A recently re-based and re-tested version is below.

Thanks,

Martin

On Mon, May 10 2021, Martin Jambor wrote:
> Hi,

>

> On Mon, May 10 2021, Richard Biener wrote:

>> I've tried to have a look at this patch but it does a lot of IPA specific

>> refactoring(?), so the actual DCE bits are hard to find.  Is it possible

>> to split the patch up or is it too entangled?

>>

>

> Yes:


I was asked by Richi to split my fix for PR 93385 for easier review
into IPA-SRA materialization refactoring and the actual DCE addition.
Fortunately it was mostly natural except for a temporary weird
condition in ipa_param_body_adjustments::modify_call_stmt.
Additionally.  In addition to the patch I posted previously, this one
also deallocated the newly added summary in toplev::finalize and fixes
a mistakenly uninitialized field.

This is the first part which basically replaces performed_splits in
clone_info and the code which generates it, keeps it up-to-date and
consumes it with new edge summaries which are much nicer.  It simply
contains 1) a mapping from the original argument indices to the actual
indices in the call statement as it is now, 2) information needed to
identify arguments representing pass-through IPA-SRA splits with which
have been added to the call arguments in place of an original
argument/reference and 3) a delta to the index where va_args may start
- so basically directly all the information that the consumer of
performed_splits had to compute and we also do not need the weird
dummy declarations.

The main disadvantage is that the information has to be created (and
kept up-to-date) for all call graph edges associated with the given
statement from all clones (including inline clones) of the clone where
splitting or removal happened first.  But all of this happens during
clone materialization so the only effect on WPA memory consumption is
the removal of a pointer from clone_info.

The statement modification code also has to know the statement from
the original function in order to be able to locate the edge summaries
which at this point are still keyed to these.  However, the code is
already quite heavily dependant on how things are structured in
tree-inline.c and in order to fix bugs like these it probably has to
be.

The subsequent patch needs this new information to be able to remove
arguments from calls during materialization and communicate this
information to the call redirection.

2021-05-17  Martin Jambor  <mjambor@suse.cz>

	PR ipa/93385
	* symtab-clones.h (clone_info): Removed member param_adjustments.
	* ipa-param-manipulation.h: Adjust initial comment to reflect how we
	deal with pass-through splits now.
	(ipa_param_performed_split): Removed.
	(ipa_param_adjustments::modify_call): Adjusted parameters.
	(class ipa_param_body_adjustments): Adjusted parameters of
	register_replacement, modify_gimple_stmt and modify_call_stmt.
	(ipa_verify_edge_has_no_modifications): Declare.
	(ipa_edge_modifications_finalize): Declare.
	* cgraph.c (cgraph_edge::redirect_call_stmt_to_callee): Remove
	performed_splits processing, pas only edge to padjs->modify_call,
	check that call arguments were not modified if they should not have
	been.
	* cgraphclones.c (cgraph_node::create_clone): Do not copy performed
	splits.
	* ipa-param-manipulation.c (struct pass_through_split_map): New type.
	(ipa_edge_modification_info): Likewise.
	(ipa_edge_modification_sum): Likewise.
	(ipa_edge_modifications): New edge summary.
	(ipa_verify_edge_has_no_modifications): New function.
	(transitive_split_p): Removed.
	(transitive_split_map): Likewise.
	(init_transitive_splits): Likewise.
	(ipa_param_adjustments::modify_call): Adjusted to use the new edge
	summary instead of performed_splits.
	(ipa_param_body_adjustments::register_replacement): Drop dummy
	parameter, set base_index of the created ipa_param_body_replacement.
	(phi_arg_will_live_p): New function.
	(ipa_param_body_adjustments::common_initialization): Do not create
	IPA_SRA dummy decls.
	(simple_tree_swap_info): Removed.
	(remap_split_decl_to_dummy): Likewise.
	(record_argument_state_1): New function.
	(record_argument_state): Likewise.
	(ipa_param_body_adjustments::modify_call_stmt): New parameter
	orig_stmt.  Do not work with dummy decls, save necessary info about
	changes to ipa_edge_modifications.
	(ipa_param_body_adjustments::modify_gimple_stmt): New parameter
	orig_stmt, pass it to modify_call_stmt.
	(ipa_param_body_adjustments::modify_cfun_body): Adjust call to
	modify_gimple_stmt.
	(ipa_edge_modifications_finalize): New function.
	* tree-inline.c (remap_gimple_stmt): Pass original statement to
	modify_gimple_stmt.
	(copy_phis_for_bb): Do not copy dead PHI nodes.
	(expand_call_inline): Do not remap performed_splits.
	(update_clone_info): Likewise.
	* toplev.c: Include ipa-param-manipulation.h.
	(toplev::finalize): Call ipa_edge_modifications_finalize.
---
 gcc/cgraph.c                 |  22 +-
 gcc/cgraphclones.c           |   3 -
 gcc/ipa-param-manipulation.c | 803 +++++++++++++++++++----------------
 gcc/ipa-param-manipulation.h |  82 ++--
 gcc/symtab-clones.h          |  15 +-
 gcc/toplev.c                 |   2 +
 gcc/tree-inline.c            | 103 +----
 7 files changed, 485 insertions(+), 545 deletions(-)

diff --git a/gcc/cgraph.c b/gcc/cgraph.c
index d7c78d518bc..d473da5a325 100644
--- a/gcc/cgraph.c
+++ b/gcc/cgraph.c
@@ -1506,8 +1506,6 @@ cgraph_edge::redirect_call_stmt_to_callee (cgraph_edge *e)
     }
 
   clone_info *callee_info = clone_info::get (e->callee);
-  clone_info *caller_info = clone_info::get (e->caller);
-
   if (symtab->dump_file)
     {
       fprintf (symtab->dump_file, "updating call of %s -> %s: ",
@@ -1515,18 +1513,6 @@ cgraph_edge::redirect_call_stmt_to_callee (cgraph_edge *e)
       print_gimple_stmt (symtab->dump_file, e->call_stmt, 0, dump_flags);
       if (callee_info && callee_info->param_adjustments)
 	callee_info->param_adjustments->dump (symtab->dump_file);
-      unsigned performed_len
-	= caller_info ? vec_safe_length (caller_info->performed_splits) : 0;
-      if (performed_len > 0)
-	fprintf (symtab->dump_file, "Performed splits records:\n");
-      for (unsigned i = 0; i < performed_len; i++)
-	{
-	  ipa_param_performed_split *sm
-	    = &(*caller_info->performed_splits)[i];
-	  print_node_brief (symtab->dump_file, "  dummy_decl: ", sm->dummy_decl,
-			    TDF_UID);
-	  fprintf (symtab->dump_file, ", unit_offset: %u\n", sm->unit_offset);
-	}
     }
 
   if (ipa_param_adjustments *padjs
@@ -1541,10 +1527,7 @@ cgraph_edge::redirect_call_stmt_to_callee (cgraph_edge *e)
 	remove_stmt_from_eh_lp (e->call_stmt);
 
       tree old_fntype = gimple_call_fntype (e->call_stmt);
-      new_stmt = padjs->modify_call (e->call_stmt,
-				     caller_info
-				     ? caller_info->performed_splits : NULL,
-				     e->callee->decl, false);
+      new_stmt = padjs->modify_call (e, false);
       cgraph_node *origin = e->callee;
       while (origin->clone_of)
 	origin = origin->clone_of;
@@ -1564,6 +1547,9 @@ cgraph_edge::redirect_call_stmt_to_callee (cgraph_edge *e)
     }
   else
     {
+      if (flag_checking
+	  && !fndecl_built_in_p (e->callee->decl, BUILT_IN_UNREACHABLE))
+	ipa_verify_edge_has_no_modifications (e);
       new_stmt = e->call_stmt;
       gimple_call_set_fndecl (new_stmt, e->callee->decl);
       update_stmt_fn (DECL_STRUCT_FUNCTION (e->caller->decl), new_stmt);
diff --git a/gcc/cgraphclones.c b/gcc/cgraphclones.c
index 9f86463b42d..7e463acab91 100644
--- a/gcc/cgraphclones.c
+++ b/gcc/cgraphclones.c
@@ -414,9 +414,6 @@ cgraph_node::create_clone (tree new_decl, profile_count prof_count,
   else if (info && info->param_adjustments)
     clone_info::get_create (new_node)->param_adjustments
 	 = info->param_adjustments;
-  if (info && info->performed_splits)
-    clone_info::get_create (new_node)->performed_splits
-	 = vec_safe_copy (info->performed_splits);
   new_node->split_part = split_part;
 
   FOR_EACH_VEC_ELT (redirect_callers, i, e)
diff --git a/gcc/ipa-param-manipulation.c b/gcc/ipa-param-manipulation.c
index f2d91476655..6a423391d2f 100644
--- a/gcc/ipa-param-manipulation.c
+++ b/gcc/ipa-param-manipulation.c
@@ -62,6 +62,80 @@ static const char *ipa_param_op_names[IPA_PARAM_PREFIX_COUNT]
      "IPA_PARAM_OP_NEW",
      "IPA_PARAM_OP_SPLIT"};
 
+/* Structure to hold declarations representing pass-through IPA-SRA splits.  In
+   essence, it tells new index for a combination of original index and
+   offset.  */
+
+struct pass_through_split_map
+{
+  /* Original argument index.  */
+  unsigned base_index;
+  /* Offset of the split part in the original argument.  */
+  unsigned unit_offset;
+  /* Index of the split part in the call statement - where clone
+     materialization put it.  */
+  int new_index;
+};
+
+/* Information about some call statements that needs to be conveyed from clone
+   materialization to edge redirection. */
+
+class ipa_edge_modification_info
+{
+ public:
+  ipa_edge_modification_info ()
+    {}
+
+  /* Mapping of original argument indices to where those arguments sit in the
+     call statement now or to a negative index if they were removed.  */
+  auto_vec<int> index_map;
+  /* Information about ISRA replacements put into the call statement at the
+     clone materialization stages.  */
+  auto_vec<pass_through_split_map> pass_through_map;
+  /* Necessary adjustment to ipa_param_adjustments::m_always_copy_start when
+     redirecting the call.  */
+  int always_copy_delta = 0;
+};
+
+/* Class for storing and retrieving summaries about cal statement
+   modifications.  */
+
+class ipa_edge_modification_sum
+  : public call_summary <ipa_edge_modification_info *>
+{
+ public:
+  ipa_edge_modification_sum (symbol_table *table)
+    : call_summary<ipa_edge_modification_info *> (table)
+  {
+  }
+
+  /* Hook that is called by summary when an edge is duplicated.  */
+
+  virtual void duplicate (cgraph_edge *,
+			  cgraph_edge *,
+			  ipa_edge_modification_info *old_info,
+			  ipa_edge_modification_info *new_info)
+  {
+    new_info->index_map.safe_splice (old_info->index_map);
+    new_info->pass_through_map.safe_splice (old_info->pass_through_map);
+    new_info->always_copy_delta = old_info->always_copy_delta;
+  }
+};
+
+/* Call summary to store information about edges which have had their arguments
+   partially modified already.  */
+
+static ipa_edge_modification_sum *ipa_edge_modifications;
+
+/* Fail compilation if CS has any summary associated with it in
+   ipa_edge_modifications.  */
+
+DEBUG_FUNCTION void
+ipa_verify_edge_has_no_modifications (cgraph_edge *cs)
+{
+  gcc_assert (!ipa_edge_modifications || !ipa_edge_modifications->get (cs));
+}
+
 /* Fill an empty vector ARGS with PARM_DECLs representing formal parameters of
    FNDECL.  The function should not be called during LTO WPA phase except for
    thunks (or functions with bodies streamed in). */
@@ -459,147 +533,46 @@ isra_get_ref_base_and_offset (tree expr, tree *base_p, unsigned *unit_offset_p)
   return true;
 }
 
-/* Return true if EXPR describes a transitive split (i.e. one that happened for
-   both the caller and the callee) as recorded in PERFORMED_SPLITS.  In that
-   case, store index of the respective record in PERFORMED_SPLITS into
-   *SM_IDX_P and the unit offset from all handled components in EXPR into
-   *UNIT_OFFSET_P.  */
-
-static bool
-transitive_split_p (vec<ipa_param_performed_split, va_gc> *performed_splits,
-		    tree expr, unsigned *sm_idx_p, unsigned *unit_offset_p)
-{
-  tree base;
-  if (!isra_get_ref_base_and_offset (expr, &base, unit_offset_p))
-    return false;
-
-  if (TREE_CODE (base) == SSA_NAME)
-    {
-      base = SSA_NAME_VAR (base);
-      if (!base)
-	return false;
-    }
-
-  unsigned len = vec_safe_length (performed_splits);
-  for (unsigned i = 0 ; i < len; i++)
-    {
-      ipa_param_performed_split *sm = &(*performed_splits)[i];
-      if (sm->dummy_decl == base)
-	{
-	  *sm_idx_p = i;
-	  return true;
-	}
-    }
-  return false;
-}
-
-/* Structure to hold declarations representing transitive IPA-SRA splits.  In
-   essence, if we need to pass UNIT_OFFSET of a parameter which originally has
-   number BASE_INDEX, we should pass down REPL.  */
-
-struct transitive_split_map
-{
-  tree repl;
-  unsigned base_index;
-  unsigned unit_offset;
-};
-
-/* If call STMT contains any parameters representing transitive splits as
-   described by PERFORMED_SPLITS, return the number of extra parameters that
-   were addded during clone materialization and fill in INDEX_MAP with adjusted
-   indices of corresponding original parameters and TRANS_MAP with description
-   of all transitive replacement descriptions.  Otherwise return zero. */
-
-static unsigned
-init_transitive_splits (vec<ipa_param_performed_split, va_gc> *performed_splits,
-			gcall *stmt, vec <unsigned> *index_map,
-			auto_vec <transitive_split_map> *trans_map)
-{
-  unsigned phony_arguments = 0;
-  unsigned stmt_idx = 0, base_index = 0;
-  unsigned nargs = gimple_call_num_args (stmt);
-  while (stmt_idx < nargs)
-    {
-      unsigned unit_offset_delta;
-      tree base_arg = gimple_call_arg (stmt, stmt_idx);
-
-      if (phony_arguments > 0)
-	index_map->safe_push (stmt_idx);
-
-      unsigned sm_idx;
-      stmt_idx++;
-      if (transitive_split_p (performed_splits, base_arg, &sm_idx,
-			      &unit_offset_delta))
-	{
-	  if (phony_arguments == 0)
-	    /* We have optimistically avoided constructing index_map do far but
-	       now it is clear it will be necessary, so let's create the easy
-	       bit we skipped until now.  */
-	    for (unsigned k = 0; k < stmt_idx; k++)
-	      index_map->safe_push (k);
-
-	  tree dummy = (*performed_splits)[sm_idx].dummy_decl;
-	  for (unsigned j = sm_idx; j < performed_splits->length (); j++)
-	    {
-	      ipa_param_performed_split *caller_split
-		= &(*performed_splits)[j];
-	      if (caller_split->dummy_decl != dummy)
-		break;
-
-	      tree arg = gimple_call_arg (stmt, stmt_idx);
-	      struct transitive_split_map tsm;
-	      tsm.repl = arg;
-	      tsm.base_index = base_index;
-	      if (caller_split->unit_offset >= unit_offset_delta)
-		{
-		  tsm.unit_offset
-		    = (caller_split->unit_offset - unit_offset_delta);
-		  trans_map->safe_push (tsm);
-		}
-
-	      phony_arguments++;
-	      stmt_idx++;
-	    }
-	}
-      base_index++;
-    }
-  return phony_arguments;
-}
-
-/* Modify actual arguments of a function call in statement STMT, assuming it
-   calls CALLEE_DECL.  CALLER_ADJ must be the description of parameter
-   adjustments of the caller or NULL if there are none.  Return the new
-   statement that replaced the old one.  When invoked, cfun and
-   current_function_decl have to be set to the caller.  */
+/* Modify actual arguments of a function call in statement currently belonging
+   to CS, and make it call CS->callee->decl.  Return the new statement that
+   replaced the old one.  When invoked, cfun and current_function_decl have to
+   be set to the caller.  */
 
 gcall *
-ipa_param_adjustments::modify_call (gcall *stmt,
-				    vec<ipa_param_performed_split,
-				        va_gc> *performed_splits,
-				    tree callee_decl, bool update_references)
+ipa_param_adjustments::modify_call (cgraph_edge *cs,
+				    bool update_references)
 {
+  gcall *stmt = cs->call_stmt;
+  tree callee_decl = cs->callee->decl;
+
+  ipa_edge_modification_info *mod_info
+    = ipa_edge_modifications ? ipa_edge_modifications->get (cs) : NULL;
+  if (mod_info && symtab->dump_file)
+    {
+      fprintf (symtab->dump_file, "Information about pre-exiting "
+	       "modifications.\n  Index map:");
+      unsigned idx_len = mod_info->index_map.length ();
+      for (unsigned i = 0; i < idx_len; i++)
+	fprintf (symtab->dump_file, " %i", mod_info->index_map[i]);
+      fprintf (symtab->dump_file, "\n  Pass-through split map: ");
+      unsigned ptm_len = mod_info->pass_through_map.length ();
+      for (unsigned i = 0; i < ptm_len; i++)
+	fprintf (symtab->dump_file,
+		 " (base_index: %u, offset: %u, new_index: %i)",
+		 mod_info->pass_through_map[i].base_index,
+		 mod_info->pass_through_map[i].unit_offset,
+		 mod_info->pass_through_map[i].new_index);
+      fprintf (symtab->dump_file, "\n  Always-copy delta: %i\n",
+	       mod_info->always_copy_delta);
+    }
+
   unsigned len = vec_safe_length (m_adj_params);
   auto_vec<tree, 16> vargs (len);
-  tree old_decl = gimple_call_fndecl (stmt);
   unsigned old_nargs = gimple_call_num_args (stmt);
+  unsigned orig_nargs = mod_info ? mod_info->index_map.length () : old_nargs;
   auto_vec<bool, 16> kept (old_nargs);
   kept.quick_grow_cleared (old_nargs);
 
-  auto_vec <unsigned, 16> index_map;
-  auto_vec <transitive_split_map> trans_map;
-  bool transitive_remapping = false;
-
-  if (performed_splits)
-    {
-      unsigned removed = init_transitive_splits (performed_splits,
-						 stmt, &index_map, &trans_map);
-      if (removed > 0)
-	{
-	  transitive_remapping = true;
-	  old_nargs -= removed;
-	}
-    }
-
   cgraph_node *current_node = cgraph_node::get (current_function_decl);
   if (update_references)
     current_node->remove_stmt_references (stmt);
@@ -612,13 +585,16 @@ ipa_param_adjustments::modify_call (gcall *stmt,
       ipa_adjusted_param *apm = &(*m_adj_params)[i];
       if (apm->op == IPA_PARAM_OP_COPY)
 	{
-	  unsigned index = apm->base_index;
-	  if (index >= old_nargs)
+	  int index = apm->base_index;
+	  if ((unsigned) index >= orig_nargs)
 	    /* Can happen if the original call has argument mismatch,
 	       ignore.  */
 	    continue;
-	  if (transitive_remapping)
-	    index = index_map[apm->base_index];
+	  if (mod_info)
+	    {
+	      index = mod_info->index_map[apm->base_index];
+	      gcc_assert (index >= 0);
+	    }
 
 	  tree arg = gimple_call_arg (stmt, index);
 
@@ -636,14 +612,17 @@ ipa_param_adjustments::modify_call (gcall *stmt,
 	 materialization.  */
       gcc_assert (apm->op == IPA_PARAM_OP_SPLIT);
 
-      /* We have to handle transitive changes differently using the maps we
-	 have created before.  So look into them first.  */
+      /* We have to handle pass-through changes differently using the map
+	 clone materialziation might have left behind.  */
       tree repl = NULL_TREE;
-      for (unsigned j = 0; j < trans_map.length (); j++)
-	if (trans_map[j].base_index == apm->base_index
-	    && trans_map[j].unit_offset == apm->unit_offset)
+      unsigned ptm_len = mod_info ? mod_info->pass_through_map.length () : 0;
+      for (unsigned j = 0; j < ptm_len; j++)
+	if (mod_info->pass_through_map[j].base_index == apm->base_index
+	    && mod_info->pass_through_map[j].unit_offset == apm->unit_offset)
 	  {
-	    repl = trans_map[j].repl;
+	    int repl_idx = mod_info->pass_through_map[j].new_index;
+	    gcc_assert (repl_idx >= 0);
+	    repl = gimple_call_arg (stmt, repl_idx);
 	    break;
 	  }
       if (repl)
@@ -652,12 +631,15 @@ ipa_param_adjustments::modify_call (gcall *stmt,
 	  continue;
 	}
 
-      unsigned index = apm->base_index;
-      if (index >= old_nargs)
+      int index = apm->base_index;
+      if ((unsigned) index >= orig_nargs)
 	/* Can happen if the original call has argument mismatch, ignore.  */
 	continue;
-      if (transitive_remapping)
-	index = index_map[apm->base_index];
+      if (mod_info)
+	{
+	  index = mod_info->index_map[apm->base_index];
+	  gcc_assert (index >= 0);
+	}
       tree base = gimple_call_arg (stmt, index);
 
       /* We create a new parameter out of the value of the old one, we can
@@ -773,8 +755,16 @@ ipa_param_adjustments::modify_call (gcall *stmt,
     }
 
   if (m_always_copy_start >= 0)
-    for (unsigned i = m_always_copy_start; i < old_nargs; i++)
-      vargs.safe_push (gimple_call_arg (stmt, i));
+    {
+      int always_copy_start = m_always_copy_start;
+      if (mod_info)
+	{
+	  always_copy_start += mod_info->always_copy_delta;
+	  gcc_assert (always_copy_start >= 0);
+	}
+      for (unsigned i = always_copy_start; i < old_nargs; i++)
+	vargs.safe_push (gimple_call_arg (stmt, i));
+    }
 
   /* For optimized away parameters, add on the caller side
      before the call
@@ -782,6 +772,7 @@ ipa_param_adjustments::modify_call (gcall *stmt,
      stmts and associate D#X with parm in decl_debug_args_lookup
      vector to say for debug info that if parameter parm had been passed,
      it would have value parm_Y(D).  */
+  tree old_decl = gimple_call_fndecl (stmt);
   if (MAY_HAVE_DEBUG_BIND_STMTS && old_decl && callee_decl)
     {
       vec<tree, va_gc> **debug_args = NULL;
@@ -799,13 +790,17 @@ ipa_param_adjustments::modify_call (gcall *stmt,
 	{
 	  if (!is_gimple_reg (old_parm) || kept[i])
 	    continue;
-	  tree origin = DECL_ORIGIN (old_parm);
 	  tree arg;
-	  if (transitive_remapping)
-	    arg = gimple_call_arg (stmt, index_map[i]);
+	  if (mod_info)
+	    {
+	      if (mod_info->index_map[i] < 0)
+		continue;
+	      arg = gimple_call_arg (stmt, mod_info->index_map[i]);
+	    }
 	  else
 	    arg = gimple_call_arg (stmt, i);
 
+	  tree origin = DECL_ORIGIN (old_parm);
 	  if (!useless_type_conversion_p (TREE_TYPE (origin), TREE_TYPE (arg)))
 	    {
 	      if (!fold_convertible_p (TREE_TYPE (origin), arg))
@@ -909,6 +904,9 @@ ipa_param_adjustments::modify_call (gcall *stmt,
 	gsi_prev (&gsi);
       }
     while (gsi_stmt (gsi) != gsi_stmt (prev_gsi));
+
+  if (mod_info)
+    ipa_edge_modifications->remove (cs);
   return new_stmt;
 }
 
@@ -931,13 +929,11 @@ ipa_param_adjustments::debug ()
   dump (stderr);
 }
 
-/* Register that REPLACEMENT should replace parameter described in APM and
-   optionally as DUMMY to mark transitive splits across calls.  */
+/* Register that REPLACEMENT should replace parameter described in APM.  */
 
 void
 ipa_param_body_adjustments::register_replacement (ipa_adjusted_param *apm,
-						  tree replacement,
-						  tree dummy)
+						  tree replacement)
 {
   gcc_checking_assert (apm->op == IPA_PARAM_OP_SPLIT
 		       || apm->op == IPA_PARAM_OP_NEW);
@@ -945,7 +941,7 @@ ipa_param_body_adjustments::register_replacement (ipa_adjusted_param *apm,
   ipa_param_body_replacement psr;
   psr.base = m_oparms[apm->prev_clone_index];
   psr.repl = replacement;
-  psr.dummy = dummy;
+  psr.dummy = NULL_TREE;
   psr.unit_offset = apm->unit_offset;
   m_replacements.safe_push (psr);
 }
@@ -1007,9 +1003,6 @@ ipa_param_body_adjustments::common_initialization (tree old_fndecl,
   auto_vec<bool, 16> kept;
   kept.reserve_exact (m_oparms.length ());
   kept.quick_grow_cleared (m_oparms.length ());
-  auto_vec<tree, 16> isra_dummy_decls;
-  isra_dummy_decls.reserve_exact (m_oparms.length ());
-  isra_dummy_decls.quick_grow_cleared (m_oparms.length ());
 
   unsigned adj_len = vec_safe_length (m_adj_params);
   m_method2func = ((TREE_CODE (TREE_TYPE (m_fndecl)) == METHOD_TYPE)
@@ -1055,35 +1048,7 @@ ipa_param_body_adjustments::common_initialization (tree old_fndecl,
 	  if (apm->op == IPA_PARAM_OP_SPLIT)
 	    {
 	      m_split_modifications_p = true;
-
-	      if (m_id)
-		{
-		  tree dummy_decl;
-		  if (!isra_dummy_decls[prev_index])
-		    {
-		      dummy_decl = copy_decl_to_var (m_oparms[prev_index],
-						     m_id);
-		      /* Any attempt to remap this dummy in this particular
-			 instance of clone materialization should yield
-			 itself.  */
-		      insert_decl_map (m_id, dummy_decl, dummy_decl);
-
-		      DECL_CHAIN (dummy_decl) = *vars;
-		      *vars = dummy_decl;
-		      isra_dummy_decls[prev_index] = dummy_decl;
-		    }
-		  else
-		    dummy_decl = isra_dummy_decls[prev_index];
-
-		  register_replacement (apm, new_parm, dummy_decl);
-		  ipa_param_performed_split ps;
-		  ps.dummy_decl = dummy_decl;
-		  ps.unit_offset = apm->unit_offset;
-		  vec_safe_push (clone_info::get_create
-				   (m_id->dst_node)->performed_splits, ps);
-		}
-	      else
-		register_replacement (apm, new_parm);
+	      register_replacement (apm, new_parm);
 	    }
         }
       else
@@ -1110,8 +1075,6 @@ ipa_param_body_adjustments::common_initialization (tree old_fndecl,
 	  {
 	    if (!m_id->decl_map->get (m_oparms[i]))
 	      {
-		/* TODO: Perhaps at least aggregate-type params could re-use
-		   their isra_dummy_decl here?  */
 		tree var = copy_decl_to_var (m_oparms[i], m_id);
 		insert_decl_map (m_id, m_oparms[i], var);
 		/* Declare this new variable.  */
@@ -1502,220 +1465,329 @@ ipa_param_body_adjustments::modify_assignment (gimple *stmt,
   return any;
 }
 
-/* Data passed to remap_split_decl_to_dummy through walk_tree.  */
+/* Record information about what modifications to call arguments have already
+   been done by clone materialization into a summary describing CS.  The
+   information is stored in NEW_INDEX_MAP, NEW_PT_MAP and NEW_ALWAYS_COPY_DELTA
+   and correspond to equivalent fields in ipa_edge_modification_info.  Return
+   the edge summary.  */
+
+static ipa_edge_modification_info *
+record_argument_state_1 (cgraph_edge *cs, const vec<int> &new_index_map,
+			 const vec<pass_through_split_map> &new_pt_map,
+			 int new_always_copy_delta)
 
-struct simple_tree_swap_info
 {
-  /* Change FROM to TO.  */
-  tree from, to;
-  /* And set DONE to true when doing so.  */
-  bool done;
-};
+  ipa_edge_modification_info *sum = ipa_edge_modifications->get_create (cs);
 
-/* Simple remapper to remap a split parameter to the same expression based on a
-   special dummy decl so that edge redirections can detect transitive splitting
-   and finish them.  */
-
-static tree
-remap_split_decl_to_dummy (tree *tp, int *walk_subtrees, void *data)
-{
-  tree t = *tp;
-
-  if (DECL_P (t) || TREE_CODE (t) == SSA_NAME)
+  unsigned len = sum->pass_through_map.length ();
+  for (unsigned i = 0; i < len; i++)
     {
-      struct simple_tree_swap_info *swapinfo
-	= (struct simple_tree_swap_info *) data;
-      if (t == swapinfo->from
-	  || (TREE_CODE (t) == SSA_NAME
-	      && SSA_NAME_VAR (t) == swapinfo->from))
-	{
-	  *tp = swapinfo->to;
-	  swapinfo->done = true;
-	}
-      *walk_subtrees = 0;
+      unsigned oldnew = sum->pass_through_map[i].new_index;
+      sum->pass_through_map[i].new_index = new_index_map[oldnew];
+    }
+
+  len = sum->index_map.length ();
+  if (len > 0)
+    {
+      unsigned nptlen = new_pt_map.length ();
+      for (unsigned j = 0; j < nptlen; j++)
+	{
+	  int inverse = -1;
+	  for (unsigned i = 0; i < len ; i++)
+	    if ((unsigned) sum->index_map[i] == new_pt_map[j].base_index)
+	    {
+	      inverse = i;
+	      break;
+	    }
+	  gcc_assert (inverse >= 0);
+	  pass_through_split_map ptm_item;
+
+	  ptm_item.base_index = inverse;
+	  ptm_item.unit_offset = new_pt_map[j].unit_offset;
+	  ptm_item.new_index = new_pt_map[j].new_index;
+	  sum->pass_through_map.safe_push (ptm_item);
+	}
+
+      for (unsigned i = 0; i < len; i++)
+	{
+	  int idx = sum->index_map[i];
+	  if (idx < 0)
+	    continue;
+	  sum->index_map[i] = new_index_map[idx];
+	}
     }
-  else if (TYPE_P (t))
-      *walk_subtrees = 0;
   else
-    *walk_subtrees = 1;
-  return NULL_TREE;
+    {
+      sum->pass_through_map.safe_splice (new_pt_map);
+      sum->index_map.safe_splice (new_index_map);
+    }
+  sum->always_copy_delta += new_always_copy_delta;
+  return sum;
 }
 
+/* Record information about what modifications to call arguments have already
+   been done by clone materialization into a summary of an edge describing the
+   call in this clone and all its clones.  NEW_INDEX_MAP, NEW_PT_MAP and
+   NEW_ALWAYS_COPY_DELTA have the same meaning as record_argument_state_1.
+
+   In order to associate the info with the right edge summaries, we need
+   address of the ORIG_STMT in the function from which we are cloning (because
+   the edges have not yet been re-assigned to the new statement that has just
+   been created) and ID, the structure governing function body copying.  */
+
+static void
+record_argument_state (copy_body_data *id, gimple *orig_stmt,
+		       const vec<int> &new_index_map,
+		       const vec<pass_through_split_map> &new_pt_map,
+		       int new_always_copy_delta)
+{
+  if (!ipa_edge_modifications)
+    ipa_edge_modifications = new ipa_edge_modification_sum (symtab);
+
+  struct cgraph_node *this_node = id->dst_node;
+  ipa_edge_modification_info *first_sum = NULL;
+  cgraph_edge *cs = this_node->get_edge (orig_stmt);
+  if (cs)
+    first_sum = record_argument_state_1 (cs, new_index_map, new_pt_map,
+					 new_always_copy_delta);
+  else
+    gcc_assert (this_node->clones);
+
+  if (!this_node->clones)
+    return;
+  for (cgraph_node *subclone = this_node->clones; subclone != this_node;)
+    {
+      cs = subclone->get_edge (orig_stmt);
+      if (cs)
+	{
+	  if (!first_sum)
+	    first_sum = record_argument_state_1 (cs, new_index_map, new_pt_map,
+						 new_always_copy_delta);
+	  else
+	    {
+	      ipa_edge_modification_info *s2
+		= ipa_edge_modifications->get_create (cs);
+	      s2->index_map.truncate (0);
+	      s2->index_map.safe_splice (first_sum->index_map);
+	      s2->pass_through_map.truncate (0);
+	      s2->pass_through_map.safe_splice (first_sum->pass_through_map);
+	      s2->always_copy_delta = first_sum->always_copy_delta;
+	    }
+	}
+      else
+	gcc_assert (subclone->clones);
+
+      if (subclone->clones)
+	subclone = subclone->clones;
+      else if (subclone->next_sibling_clone)
+	subclone = subclone->next_sibling_clone;
+      else
+	{
+	  while (subclone != this_node && !subclone->next_sibling_clone)
+	    subclone = subclone->clone_of;
+	  if (subclone != this_node)
+	    subclone = subclone->next_sibling_clone;
+	}
+    }
+}
 
 /* If the call statement pointed at by STMT_P contains any expressions that
    need to replaced with a different one as noted by ADJUSTMENTS, do so.  f the
    statement needs to be rebuilt, do so.  Return true if any modifications have
-   been performed.
+   been performed.  ORIG_STMT, if not NULL, is the original statement in the
+   function that is being cloned from, which at this point can be used to look
+   up call_graph edges.
 
    If the method is invoked as a part of IPA clone materialization and if any
-   parameter split is transitive, i.e. it applies to the functin that is being
-   modified and also to the callee of the statement, replace the parameter
-   passed to old callee with an equivalent expression based on a dummy decl
-   followed by PARM_DECLs representing the actual replacements.  The actual
-   replacements will be then converted into SSA_NAMEs and then
-   ipa_param_adjustments::modify_call will find the appropriate ones and leave
-   only those in the call.  */
+   parameter split is pass-through, i.e. it applies to the functin that is
+   being modified and also to the callee of the statement, replace the
+   parameter passed to old callee with all of the replacement a callee might
+   possibly want and record the performed argument modifications in
+   ipa_edge_modifications.  Likewise if any argument has already been left out
+   because it is not necessary.  */
 
 bool
-ipa_param_body_adjustments::modify_call_stmt (gcall **stmt_p)
+ipa_param_body_adjustments::modify_call_stmt (gcall **stmt_p,
+					      gimple *orig_stmt)
 {
-  gcall *stmt = *stmt_p;
   auto_vec <unsigned, 4> pass_through_args;
   auto_vec <unsigned, 4> pass_through_pbr_indices;
+  auto_vec <HOST_WIDE_INT, 4> pass_through_offsets;
+  gcall *stmt = *stmt_p;
+  unsigned nargs = gimple_call_num_args (stmt);
+  bool recreate = false;
 
-  if (m_split_modifications_p && m_id)
+  for (unsigned i = 0; i < gimple_call_num_args (stmt); i++)
     {
-      for (unsigned i = 0; i < gimple_call_num_args (stmt); i++)
+      tree t = gimple_call_arg (stmt, i);
+      gcc_assert (TREE_CODE (t) != BIT_FIELD_REF
+		  && TREE_CODE (t) != IMAGPART_EXPR
+		  && TREE_CODE (t) != REALPART_EXPR);
+
+      /* The follow-up patch will check whether t needs to be removed, that's
+	 why this condition is in the loop.  */
+
+      if (!m_split_modifications_p)
+	continue;
+
+      tree base;
+      unsigned agg_arg_offset;
+      if (!isra_get_ref_base_and_offset (t, &base, &agg_arg_offset))
+	continue;
+
+      bool by_ref = false;
+      if (TREE_CODE (base) == SSA_NAME)
 	{
-	  tree t = gimple_call_arg (stmt, i);
-	  gcc_assert (TREE_CODE (t) != BIT_FIELD_REF
-		      && TREE_CODE (t) != IMAGPART_EXPR
-		      && TREE_CODE (t) != REALPART_EXPR);
-
-	  tree base;
-	  unsigned unit_offset;
-	  if (!isra_get_ref_base_and_offset (t, &base, &unit_offset))
+	  if (!SSA_NAME_IS_DEFAULT_DEF (base))
 	    continue;
+	  base = SSA_NAME_VAR (base);
+	  gcc_checking_assert (base);
+	  by_ref = true;
+	}
+      if (TREE_CODE (base) != PARM_DECL)
+	continue;
 
-	  bool by_ref = false;
-	  if (TREE_CODE (base) == SSA_NAME)
+      bool base_among_replacements = false;
+      unsigned j, repl_list_len = m_replacements.length ();
+      for (j = 0; j < repl_list_len; j++)
+	{
+	  ipa_param_body_replacement *pbr = &m_replacements[j];
+	  if (pbr->base == base)
 	    {
-	      if (!SSA_NAME_IS_DEFAULT_DEF (base))
-		continue;
-	      base = SSA_NAME_VAR (base);
-	      gcc_checking_assert (base);
-	      by_ref = true;
+	      base_among_replacements = true;
+	      break;
 	    }
-	  if (TREE_CODE (base) != PARM_DECL)
-	    continue;
+	}
+      if (!base_among_replacements)
+	continue;
 
-	  bool base_among_replacements = false;
-	  unsigned j, repl_list_len = m_replacements.length ();
-	  for (j = 0; j < repl_list_len; j++)
+      /* We still have to distinguish between an end-use that we have to
+	 transform now and a pass-through, which happens in the following
+	 two cases.  */
+
+      /* TODO: After we adjust ptr_parm_has_nonarg_uses to also consider
+	 &MEM_REF[ssa_name + offset], we will also have to detect that case
+	 here.    */
+
+      if (TREE_CODE (t) == SSA_NAME
+	  && SSA_NAME_IS_DEFAULT_DEF (t)
+	  && SSA_NAME_VAR (t)
+	  && TREE_CODE (SSA_NAME_VAR (t)) == PARM_DECL)
+	{
+	  /* This must be a by_reference pass-through.  */
+	  recreate = true;
+	  gcc_assert (POINTER_TYPE_P (TREE_TYPE (t)));
+	  pass_through_args.safe_push (i);
+	  pass_through_pbr_indices.safe_push (j);
+	  pass_through_offsets.safe_push (agg_arg_offset);
+	}
+      else if (!by_ref && AGGREGATE_TYPE_P (TREE_TYPE (t)))
+	{
+	  /* Currently IPA-SRA guarantees the aggregate access type
+	     exactly matches in this case.  So if it does not match, it is
+	     a pass-through argument that will be sorted out at edge
+	     redirection time.  */
+	  ipa_param_body_replacement *pbr
+	    = lookup_replacement_1 (base, agg_arg_offset);
+
+	  if (!pbr
+	      || (TYPE_MAIN_VARIANT (TREE_TYPE (t))
+		  != TYPE_MAIN_VARIANT (TREE_TYPE (pbr->repl))))
 	    {
-	      ipa_param_body_replacement *pbr = &m_replacements[j];
-	      if (pbr->base == base)
-		{
-		  base_among_replacements = true;
-		  break;
-		}
-	    }
-	  if (!base_among_replacements)
-	    continue;
-
-	  /* We still have to distinguish between an end-use that we have to
-	     transform now and a pass-through, which happens in the following
-	     two cases.  */
-
-	  /* TODO: After we adjust ptr_parm_has_nonarg_uses to also consider
-	     &MEM_REF[ssa_name + offset], we will also have to detect that case
-	     here.    */
-
-	  if (TREE_CODE (t) == SSA_NAME
-	      && SSA_NAME_IS_DEFAULT_DEF (t)
-	      && SSA_NAME_VAR (t)
-	      && TREE_CODE (SSA_NAME_VAR (t)) == PARM_DECL)
-	    {
-	      /* This must be a by_reference pass-through.  */
-	      gcc_assert (POINTER_TYPE_P (TREE_TYPE (t)));
+	      recreate = true;
 	      pass_through_args.safe_push (i);
 	      pass_through_pbr_indices.safe_push (j);
-	    }
-	  else if (!by_ref && AGGREGATE_TYPE_P (TREE_TYPE (t)))
-	    {
-	      /* Currently IPA-SRA guarantees the aggregate access type
-		 exactly matches in this case.  So if it does not match, it is
-		 a pass-through argument that will be sorted out at edge
-		 redirection time.  */
-	      ipa_param_body_replacement *pbr
-		= lookup_replacement_1 (base, unit_offset);
-
-	      if (!pbr
-		  || (TYPE_MAIN_VARIANT (TREE_TYPE (t))
-		      != TYPE_MAIN_VARIANT (TREE_TYPE (pbr->repl))))
-		{
-		  pass_through_args.safe_push (i);
-		  pass_through_pbr_indices.safe_push (j);
-		}
+	      pass_through_offsets.safe_push (agg_arg_offset);
 	    }
 	}
     }
 
-  unsigned nargs = gimple_call_num_args (stmt);
-  if (!pass_through_args.is_empty ())
+  if (!recreate)
     {
-      auto_vec<tree, 16> vargs;
-      unsigned pt_idx = 0;
+      /* No need to rebuild the statement, let's just modify arguments
+	 and the LHS if/as appropriate.  */
+      bool modified = false;
       for (unsigned i = 0; i < nargs; i++)
 	{
-	  if (pt_idx < pass_through_args.length ()
-	      && i == pass_through_args[pt_idx])
-	    {
-	      unsigned j = pass_through_pbr_indices[pt_idx];
-	      pt_idx++;
-	      tree base = m_replacements[j].base;
-
-	      /* Map base will get mapped to the special transitive-isra marker
-		 dummy decl. */
-	      struct simple_tree_swap_info swapinfo;
-	      swapinfo.from = base;
-	      swapinfo.to = m_replacements[j].dummy;
-	      swapinfo.done = false;
-	      tree arg = gimple_call_arg (stmt, i);
-	      walk_tree (&arg, remap_split_decl_to_dummy, &swapinfo, NULL);
-	      gcc_assert (swapinfo.done);
-	      vargs.safe_push (arg);
-	      /* Now let's push all replacements pertaining to this parameter
-		 so that all gimple register ones get correct SSA_NAMES.  Edge
-		 redirection will weed out the dummy argument as well as all
-		 unused replacements later.  */
-	      unsigned int repl_list_len = m_replacements.length ();
-	      for (; j < repl_list_len; j++)
-		{
-		  if (m_replacements[j].base != base)
-		    break;
-		  vargs.safe_push (m_replacements[j].repl);
-		}
-	    }
-	  else
-	    {
-	      tree t = gimple_call_arg (stmt, i);
-	      modify_expression (&t, true);
-	      vargs.safe_push (t);
-	    }
+	  tree *t = gimple_call_arg_ptr (stmt, i);
+	  modified |= modify_expression (t, true);
 	}
-      gcall *new_stmt = gimple_build_call_vec (gimple_call_fn (stmt), vargs);
-      if (gimple_has_location (stmt))
-	gimple_set_location (new_stmt, gimple_location (stmt));
-      gimple_call_set_chain (new_stmt, gimple_call_chain (stmt));
-      gimple_call_copy_flags (new_stmt, stmt);
-      if (tree lhs = gimple_call_lhs (stmt))
+      if (gimple_call_lhs (stmt))
 	{
-	  modify_expression (&lhs, false);
-	  /* Avoid adjusting SSA_NAME_DEF_STMT of a SSA lhs, SSA names
-	     have not yet been remapped.  */
-	  *gimple_call_lhs_ptr (new_stmt) = lhs;
+	  tree *t = gimple_call_lhs_ptr (stmt);
+	  modified |= modify_expression (t, false);
 	}
-      *stmt_p = new_stmt;
-      return true;
+      return modified;
     }
 
-  /* Otherwise, no need to rebuild the statement, let's just modify arguments
-     and the LHS if/as appropriate.  */
-  bool modified = false;
+  auto_vec<int, 16> index_map;
+  auto_vec<pass_through_split_map, 4> pass_through_map;
+  auto_vec<tree, 16> vargs;
+  int always_copy_delta = 0;
+  unsigned pt_idx = 0;
+  int new_arg_idx = 0;
   for (unsigned i = 0; i < nargs; i++)
     {
-      tree *t = gimple_call_arg_ptr (stmt, i);
-      modified |= modify_expression (t, true);
+      if (pt_idx < pass_through_args.length ()
+	  && i == pass_through_args[pt_idx])
+	{
+	  unsigned j = pass_through_pbr_indices[pt_idx];
+	  unsigned agg_arg_offset = pass_through_offsets[pt_idx];
+	  pt_idx++;
+	  always_copy_delta--;
+	  tree base = m_replacements[j].base;
+
+	  /* In order to be put into SSA form, we have to push all replacements
+	     pertaining to this parameter as parameters to the call statement.
+	     Edge redirection will need to use edge summary to weed out the
+	     unnecessary ones.  */
+	  unsigned repl_list_len = m_replacements.length ();
+	  for (; j < repl_list_len; j++)
+	    {
+	      if (m_replacements[j].base != base)
+		break;
+	      if (m_replacements[j].unit_offset < agg_arg_offset)
+		continue;
+	      pass_through_split_map pt_map;
+	      pt_map.base_index = i;
+	      pt_map.unit_offset
+		= m_replacements[j].unit_offset - agg_arg_offset;
+	      pt_map.new_index = new_arg_idx;
+	      pass_through_map.safe_push (pt_map);
+	      vargs.safe_push (m_replacements[j].repl);
+	      new_arg_idx++;
+	      always_copy_delta++;
+	    }
+	  index_map.safe_push (-1);
+	}
+      else
+	{
+	  tree t = gimple_call_arg (stmt, i);
+	  modify_expression (&t, true);
+	  vargs.safe_push (t);
+	  index_map.safe_push (new_arg_idx);
+	  new_arg_idx++;
+	}
     }
 
-  if (gimple_call_lhs (stmt))
+  gcall *new_stmt = gimple_build_call_vec (gimple_call_fn (stmt), vargs);
+  if (gimple_has_location (stmt))
+    gimple_set_location (new_stmt, gimple_location (stmt));
+  gimple_call_set_chain (new_stmt, gimple_call_chain (stmt));
+  gimple_call_copy_flags (new_stmt, stmt);
+  if (tree lhs = gimple_call_lhs (stmt))
     {
-      tree *t = gimple_call_lhs_ptr (stmt);
-      modified |= modify_expression (t, false);
+      modify_expression (&lhs, false);
+      /* Avoid adjusting SSA_NAME_DEF_STMT of a SSA lhs, SSA names
+	 have not yet been remapped.  */
+      *gimple_call_lhs_ptr (new_stmt) = lhs;
     }
+  *stmt_p = new_stmt;
 
-  return modified;
+  if (orig_stmt)
+    record_argument_state (m_id, orig_stmt, index_map, pass_through_map,
+			   always_copy_delta);
+  return true;
 }
 
 /* If the statement STMT contains any expressions that need to replaced with a
@@ -1726,7 +1798,8 @@ ipa_param_body_adjustments::modify_call_stmt (gcall **stmt_p)
 
 bool
 ipa_param_body_adjustments::modify_gimple_stmt (gimple **stmt,
-						gimple_seq *extra_stmts)
+						gimple_seq *extra_stmts,
+						gimple *orig_stmt)
 {
   bool modified = false;
   tree *t;
@@ -1746,7 +1819,7 @@ ipa_param_body_adjustments::modify_gimple_stmt (gimple **stmt,
       break;
 
     case GIMPLE_CALL:
-      modified |= modify_call_stmt ((gcall **) stmt);
+      modified |= modify_call_stmt ((gcall **) stmt, orig_stmt);
       break;
 
     case GIMPLE_ASM:
@@ -1803,7 +1876,7 @@ ipa_param_body_adjustments::modify_cfun_body ()
 	  gimple *stmt = gsi_stmt (gsi);
 	  gimple *stmt_copy = stmt;
 	  gimple_seq extra_stmts = NULL;
-	  bool modified = modify_gimple_stmt (&stmt, &extra_stmts);
+	  bool modified = modify_gimple_stmt (&stmt, &extra_stmts, NULL);
 	  if (stmt != stmt_copy)
 	    {
 	      gcc_checking_assert (modified);
@@ -1952,3 +2025,17 @@ ipa_param_body_adjustments::perform_cfun_body_modifications ()
   return cfg_changed;
 }
 
+
+/* Deallocate summaries which otherwise stay alive until the end of
+   compilation.  */
+
+void
+ipa_edge_modifications_finalize ()
+{
+  if (!ipa_edge_modifications)
+    return;
+  delete ipa_edge_modifications;
+  ipa_edge_modifications = NULL;
+}
+
+
diff --git a/gcc/ipa-param-manipulation.h b/gcc/ipa-param-manipulation.h
index c80e1bc5d6b..31dcc4b9768 100644
--- a/gcc/ipa-param-manipulation.h
+++ b/gcc/ipa-param-manipulation.h
@@ -54,7 +54,7 @@ or only a vector of ipa_adjusted_params.
 When these classes are used in the context of call graph clone materialization
 and subsequent call statement redirection - which is the point at which we
 modify arguments in call statements - they need to cooperate with each other in
-order to handle what we refer to as transitive (IPA-SRA) splits.  These are
+order to handle what we refer to as pass-through (IPA-SRA) splits.  These are
 situations when a formal parameter of one function is split into several
 smaller ones and some of them are then passed on in a call to another function
 because the formal parameter of this callee has also been split.
@@ -83,7 +83,7 @@ baz ()
 Both bar and foo would have their parameter split.  Foo would receive one
 replacement representing s.b.  Function bar would see its parameter split into
 one replacement representing z.s.a and another representing z.s.b which would
-be passed on to foo.  It would be a so called transitive split IPA-SRA
+be passed on to foo.  It would be a so called pass-through split IPA-SRA
 replacement, one which is passed in a call as an actual argument to another
 IPA-SRA replacement in another function.
 
@@ -95,30 +95,25 @@ all of the above.
 
 Call redirection has to be able to find the right decl or SSA_NAME that
 corresponds to the transitive split in the caller.  The SSA names are assigned
-right after clone materialization/ modification and cannot be "added"
-afterwards.  Moreover, if the caller has been inlined the SSA_NAMEs in question
-no longer belong to PARM_DECLs but to VAR_DECLs, indistinguishable from any
-others.
+right after clone materialization/ modification and cannot be "added" to call
+arguments at any later point.  Moreover, if the caller has been inlined the
+SSA_NAMEs in question no longer belong to PARM_DECLs but to VAR_DECLs,
+indistinguishable from any others.
 
 Therefore, when clone materialization finds a call statement which it knows is
-a part of a transitive split, it will modify it into:
+a part of a transitive split, it will simply add as arguments all new "split"
+replacements (that have grater or equal offset than the original call
+argument):
 
-  foo (DUMMY_Z_VAR.s, repl_for_a, repl_for_b, <rest of original arguments>);
+  foo (repl_for_a, repl_for_b, <rest of original arguments>);
 
-It will also store {DUMMY_S_VAR, 32} and {DUMMY_S_VAR, 64} representing offsets
-of z.s.a and z.s.b (assuming a 32-bit int) into foo's cgraph node
-clone->performed_splits vector (which is storing structures of type
-ipa_param_performed_split also defined in this header file).
-
-Call redirection will identify that expression DUMMY_Z_VAR.s is based on a
-variable stored in performed_splits vector and learn that the following
-arguments, already in SSA form, represent offsets 32 and 64 in a split original
-parameter.  It subtracts offset of DUMMY_Z_VAR.s from 32 and 64 and arrives at
-offsets 0 and 32 within callee's original parameter.  At this point it also
-knows from the call graph that only the bit with offset 32 is needed and so
-changes the call statement into final:
-
-bar (repl_for_b, <rest of original arguments>);  */
+It will also store into ipa_edge_modification_info (which is internal to
+ipa-param-modification.c) information about which replacement is which and
+where original arguments are.  Call redirection will then invoke
+ipa_param_adjustments::modify_call which will access this information and
+eliminate all replacements which the callee does not expect (repl_for_a in our
+example above).  In between these two steps, however, a call statement might
+have extraneous arguments.  */
 
 #ifndef IPA_PARAM_MANIPULATION_H
 #define IPA_PARAM_MANIPULATION_H
@@ -207,21 +202,6 @@ struct GTY(()) ipa_adjusted_param
 void ipa_dump_adjusted_parameters (FILE *f,
 				   vec<ipa_adjusted_param, va_gc> *adj_params);
 
-/* Structure to remember the split performed on a node so that edge redirection
-   (i.e. splitting arguments of call statements) know how split formal
-   parameters of the caller are represented.  */
-
-struct GTY(()) ipa_param_performed_split
-{
-  /* The dummy VAR_DECL that was created instead of the split parameter that
-     sits in the call in the meantime between clone materialization and call
-     redirection.  All entries in a vector of performed splits that correspond
-     to the same dumy decl must be grouped together.  */
-  tree dummy_decl;
-  /* Offset into the original parameter.  */
-  unsigned unit_offset;
-};
-
 /* Class used to record planned modifications to parameters of a function and
    also to perform necessary modifications at the caller side at the gimple
    level.  Used to describe all cgraph node clones that have their parameters
@@ -244,9 +224,7 @@ public:
 
   /* Modify a call statement arguments (and possibly remove the return value)
      as described in the data fields of this class.  */
-  gcall *modify_call (gcall *stmt,
-		      vec<ipa_param_performed_split, va_gc> *performed_splits,
-		      tree callee_decl, bool update_references);
+  gcall *modify_call (cgraph_edge *cs, bool update_references);
   /* Return if the first parameter is left intact.  */
   bool first_param_intact_p ();
   /* Build a function type corresponding to the modified call.  */
@@ -293,15 +271,9 @@ struct ipa_param_body_replacement
   tree base;
   /* The new decl it should be replaced with.  */
   tree repl;
-  /* When modifying clones during IPA clone materialization, this is a dummy
-     decl used to mark calls in which we need to apply transitive splitting,
-     these dummy delcls are inserted as arguments to such calls and then
-     followed by all the replacements with offset info stored in
-     ipa_param_performed_split.
-
-     Users of ipa_param_body_adjustments that modify standalone functions
-     outside of IPA clone materialization can use this field for their internal
-     purposes.  */
+  /* Users of ipa_param_body_adjustments that modify standalone functions
+     outside of IPA clone materialization can use the following field for their
+     internal purposes.  */
   tree dummy;
   /* The offset within BASE that REPL represents.  */
   unsigned unit_offset;
@@ -342,8 +314,7 @@ public:
   /* Change the PARM_DECLs.  */
   void modify_formal_parameters ();
   /* Register a replacement decl for the transformation done in APM.  */
-  void register_replacement (ipa_adjusted_param *apm, tree replacement,
-			     tree dummy = NULL_TREE);
+  void register_replacement (ipa_adjusted_param *apm, tree replacement);
   /* Lookup a replacement for a given offset within a given parameter.  */
   tree lookup_replacement (tree base, unsigned unit_offset);
   /* Lookup a replacement for an expression, if there is one.  */
@@ -353,7 +324,8 @@ public:
      parameter. */
   tree get_replacement_ssa_base (tree old_decl);
   /* Modify a statement.  */
-  bool modify_gimple_stmt (gimple **stmt, gimple_seq *extra_stmts);
+  bool modify_gimple_stmt (gimple **stmt, gimple_seq *extra_stmts,
+			   gimple *orig_stmt);
   /* Return the new chain of parameters.  */
   tree get_new_param_chain ();
 
@@ -380,9 +352,10 @@ private:
   tree replace_removed_params_ssa_names (tree old_name, gimple *stmt);
   bool modify_expression (tree *expr_p, bool convert);
   bool modify_assignment (gimple *stmt, gimple_seq *extra_stmts);
-  bool modify_call_stmt (gcall **stmt_p);
+  bool modify_call_stmt (gcall **stmt_p, gimple *orig_stmt);
   bool modify_cfun_body ();
   void reset_debug_stmts ();
+  void mark_dead_statements (tree dead_param);
 
   /* Declaration of the function that is being transformed.  */
 
@@ -431,5 +404,8 @@ private:
 
 void push_function_arg_decls (vec<tree> *args, tree fndecl);
 void push_function_arg_types (vec<tree> *types, tree fntype);
+void ipa_verify_edge_has_no_modifications (cgraph_edge *cs);
+void ipa_edge_modifications_finalize ();
+
 
 #endif	/* IPA_PARAM_MANIPULATION_H */
diff --git a/gcc/symtab-clones.h b/gcc/symtab-clones.h
index 5695a434f6a..a6ad4a6e27f 100644
--- a/gcc/symtab-clones.h
+++ b/gcc/symtab-clones.h
@@ -26,8 +26,7 @@ struct GTY(()) clone_info
   /* Constructor.  */
   clone_info ()
     : tree_map (NULL),
-      param_adjustments (NULL),
-      performed_splits (NULL)
+      param_adjustments (NULL)
   {
   }
   /* Constants discovered by IPA-CP, i.e. which parameter should be replaced
@@ -35,18 +34,6 @@ struct GTY(()) clone_info
   vec<ipa_replace_map *, va_gc> *tree_map;
   /* Parameter modification that IPA-SRA decided to perform.  */
   ipa_param_adjustments *param_adjustments;
-  /* Lists of dummy-decl and offset pairs representing split formal parameters
-     in the caller.  Offsets of all new replacements are enumerated, those
-     coming from the same original parameter have the same dummy decl stored
-     along with them.
-
-     Dummy decls sit in call statement arguments followed by new parameter
-     decls (or their SSA names) in between (caller) clone materialization and
-     call redirection.  Redirection then recognizes the dummy variable and
-     together with the stored offsets can reconstruct what exactly the new
-     parameter decls represent and can leave in place only those that the
-     callee expects.  */
-  vec<ipa_param_performed_split, va_gc> *performed_splits;
 
   /* Return clone_info, if available.  */
   static clone_info *get (cgraph_node *node);
diff --git a/gcc/toplev.c b/gcc/toplev.c
index 6a6ebe9bb8c..0f9dfe3c27f 100644
--- a/gcc/toplev.c
+++ b/gcc/toplev.c
@@ -86,6 +86,7 @@ along with GCC; see the file COPYING3.  If not see
 #include "optinfo-emit-json.h"
 #include "ipa-modref-tree.h"
 #include "ipa-modref.h"
+#include "ipa-param-manipulation.h"
 #include "dbgcnt.h"
 
 #if defined(DBX_DEBUGGING_INFO) || defined(XCOFF_DEBUGGING_INFO)
@@ -2386,6 +2387,7 @@ toplev::finalize (void)
   ipa_reference_c_finalize ();
   ipa_fnsummary_c_finalize ();
   ipa_modref_c_finalize ();
+  ipa_edge_modifications_finalize ();
 
   cgraph_c_finalize ();
   cgraphunit_c_finalize ();
diff --git a/gcc/tree-inline.c b/gcc/tree-inline.c
index 4250fd86487..489392c98f9 100644
--- a/gcc/tree-inline.c
+++ b/gcc/tree-inline.c
@@ -1921,7 +1921,7 @@ remap_gimple_stmt (gimple *stmt, copy_body_data *id)
   if (id->param_body_adjs)
     {
       gimple_seq extra_stmts = NULL;
-      id->param_body_adjs->modify_gimple_stmt (&copy, &extra_stmts);
+      id->param_body_adjs->modify_gimple_stmt (&copy, &extra_stmts, stmt);
       if (!gimple_seq_empty_p (extra_stmts))
 	{
 	  memset (&wi, 0, sizeof (wi));
@@ -4738,7 +4738,6 @@ expand_call_inline (basic_block bb, gimple *stmt, copy_body_data *id,
   use_operand_p use;
   gimple *simtenter_stmt = NULL;
   vec<tree> *simtvars_save;
-  clone_info *info;
 
   /* The gimplifier uses input_location in too many places, such as
      internal_get_tmp_var ().  */
@@ -5063,40 +5062,6 @@ expand_call_inline (basic_block bb, gimple *stmt, copy_body_data *id,
   /* Add local vars in this inlined callee to caller.  */
   add_local_variables (id->src_cfun, cfun, id);
 
-  info = clone_info::get (id->src_node);
-  if (info && info->performed_splits)
-    {
-      clone_info *dst_info = clone_info::get_create (id->dst_node);
-      /* Any calls from the inlined function will be turned into calls from the
-	 function we inline into.  We must preserve notes about how to split
-	 parameters such calls should be redirected/updated.  */
-      unsigned len = vec_safe_length (info->performed_splits);
-      for (unsigned i = 0; i < len; i++)
-	{
-	  ipa_param_performed_split ps
-	    = (*info->performed_splits)[i];
-	  ps.dummy_decl = remap_decl (ps.dummy_decl, id);
-	  vec_safe_push (dst_info->performed_splits, ps);
-	}
-
-      if (flag_checking)
-	{
-	  len = vec_safe_length (dst_info->performed_splits);
-	  for (unsigned i = 0; i < len; i++)
-	    {
-	      ipa_param_performed_split *ps1
-		= &(*dst_info->performed_splits)[i];
-	      for (unsigned j = i + 1; j < len; j++)
-		{
-		  ipa_param_performed_split *ps2
-		    = &(*dst_info->performed_splits)[j];
-		  gcc_assert (ps1->dummy_decl != ps2->dummy_decl
-			      || ps1->unit_offset != ps2->unit_offset);
-		}
-	    }
-	}
-    }
-
   if (dump_enabled_p ())
     {
       char buf[128];
@@ -6120,23 +6085,10 @@ tree_versionable_function_p (tree fndecl)
 static void
 update_clone_info (copy_body_data * id)
 {
-  clone_info *dst_info = clone_info::get (id->dst_node);
-  vec<ipa_param_performed_split, va_gc> *cur_performed_splits
-    = dst_info ? dst_info->performed_splits : NULL;
-  if (cur_performed_splits)
-    {
-      unsigned len = cur_performed_splits->length ();
-      for (unsigned i = 0; i < len; i++)
-	{
-	  ipa_param_performed_split *ps = &(*cur_performed_splits)[i];
-	  ps->dummy_decl = remap_decl (ps->dummy_decl, id);
-	}
-    }
-
-  struct cgraph_node *node;
-  if (!id->dst_node->clones)
+  struct cgraph_node *this_node = id->dst_node;
+  if (!this_node->clones)
     return;
-  for (node = id->dst_node->clones; node != id->dst_node;)
+  for (cgraph_node *node = this_node->clones; node != this_node;)
     {
       /* First update replace maps to match the new body.  */
       clone_info *info = clone_info::get (node);
@@ -6150,53 +6102,6 @@ update_clone_info (copy_body_data * id)
 	      walk_tree (&replace_info->new_tree, copy_tree_body_r, id, NULL);
 	    }
 	}
-      if (info && info->performed_splits)
-	{
-	  unsigned len = vec_safe_length (info->performed_splits);
-	  for (unsigned i = 0; i < len; i++)
-	    {
-	      ipa_param_performed_split *ps
-		= &(*info->performed_splits)[i];
-	      ps->dummy_decl = remap_decl (ps->dummy_decl, id);
-	    }
-	}
-      if (unsigned len = vec_safe_length (cur_performed_splits))
-	{
-	  /* We do not want to add current performed splits when we are saving
-	     a copy of function body for later during inlining, that would just
-	     duplicate all entries.  So let's have a look whether anything
-	     referring to the first dummy_decl is present.  */
-	  if (!info)
-	    info = clone_info::get_create (node);
-	  unsigned dst_len = vec_safe_length (info->performed_splits);
-	  ipa_param_performed_split *first = &(*cur_performed_splits)[0];
-	  for (unsigned i = 0; i < dst_len; i++)
-	    if ((*info->performed_splits)[i].dummy_decl
-		== first->dummy_decl)
-	      {
-		len = 0;
-		break;
-	      }
-
-	  for (unsigned i = 0; i < len; i++)
-	    vec_safe_push (info->performed_splits,
-			   (*cur_performed_splits)[i]);
-	  if (flag_checking)
-	    {
-	      for (unsigned i = 0; i < dst_len; i++)
-		{
-		  ipa_param_performed_split *ps1
-		    = &(*info->performed_splits)[i];
-		  for (unsigned j = i + 1; j < dst_len; j++)
-		    {
-		      ipa_param_performed_split *ps2
-			= &(*info->performed_splits)[j];
-		      gcc_assert (ps1->dummy_decl != ps2->dummy_decl
-				  || ps1->unit_offset != ps2->unit_offset);
-		    }
-		}
-	    }
-	}
 
       if (node->clones)
 	node = node->clones;
-- 
2.31.1

Patch

diff --git a/gcc/cgraph.c b/gcc/cgraph.c
index d7c78d518bc..d473da5a325 100644
--- a/gcc/cgraph.c
+++ b/gcc/cgraph.c
@@ -1506,8 +1506,6 @@  cgraph_edge::redirect_call_stmt_to_callee (cgraph_edge *e)
     }
 
   clone_info *callee_info = clone_info::get (e->callee);
-  clone_info *caller_info = clone_info::get (e->caller);
-
   if (symtab->dump_file)
     {
       fprintf (symtab->dump_file, "updating call of %s -> %s: ",
@@ -1515,18 +1513,6 @@  cgraph_edge::redirect_call_stmt_to_callee (cgraph_edge *e)
       print_gimple_stmt (symtab->dump_file, e->call_stmt, 0, dump_flags);
       if (callee_info && callee_info->param_adjustments)
 	callee_info->param_adjustments->dump (symtab->dump_file);
-      unsigned performed_len
-	= caller_info ? vec_safe_length (caller_info->performed_splits) : 0;
-      if (performed_len > 0)
-	fprintf (symtab->dump_file, "Performed splits records:\n");
-      for (unsigned i = 0; i < performed_len; i++)
-	{
-	  ipa_param_performed_split *sm
-	    = &(*caller_info->performed_splits)[i];
-	  print_node_brief (symtab->dump_file, "  dummy_decl: ", sm->dummy_decl,
-			    TDF_UID);
-	  fprintf (symtab->dump_file, ", unit_offset: %u\n", sm->unit_offset);
-	}
     }
 
   if (ipa_param_adjustments *padjs
@@ -1541,10 +1527,7 @@  cgraph_edge::redirect_call_stmt_to_callee (cgraph_edge *e)
 	remove_stmt_from_eh_lp (e->call_stmt);
 
       tree old_fntype = gimple_call_fntype (e->call_stmt);
-      new_stmt = padjs->modify_call (e->call_stmt,
-				     caller_info
-				     ? caller_info->performed_splits : NULL,
-				     e->callee->decl, false);
+      new_stmt = padjs->modify_call (e, false);
       cgraph_node *origin = e->callee;
       while (origin->clone_of)
 	origin = origin->clone_of;
@@ -1564,6 +1547,9 @@  cgraph_edge::redirect_call_stmt_to_callee (cgraph_edge *e)
     }
   else
     {
+      if (flag_checking
+	  && !fndecl_built_in_p (e->callee->decl, BUILT_IN_UNREACHABLE))
+	ipa_verify_edge_has_no_modifications (e);
       new_stmt = e->call_stmt;
       gimple_call_set_fndecl (new_stmt, e->callee->decl);
       update_stmt_fn (DECL_STRUCT_FUNCTION (e->caller->decl), new_stmt);
diff --git a/gcc/cgraphclones.c b/gcc/cgraphclones.c
index 9f86463b42d..7e463acab91 100644
--- a/gcc/cgraphclones.c
+++ b/gcc/cgraphclones.c
@@ -414,9 +414,6 @@  cgraph_node::create_clone (tree new_decl, profile_count prof_count,
   else if (info && info->param_adjustments)
     clone_info::get_create (new_node)->param_adjustments
 	 = info->param_adjustments;
-  if (info && info->performed_splits)
-    clone_info::get_create (new_node)->performed_splits
-	 = vec_safe_copy (info->performed_splits);
   new_node->split_part = split_part;
 
   FOR_EACH_VEC_ELT (redirect_callers, i, e)
diff --git a/gcc/ipa-param-manipulation.c b/gcc/ipa-param-manipulation.c
index 132bb24f76a..3e07fd72fe2 100644
--- a/gcc/ipa-param-manipulation.c
+++ b/gcc/ipa-param-manipulation.c
@@ -62,6 +62,80 @@  static const char *ipa_param_op_names[IPA_PARAM_PREFIX_COUNT]
      "IPA_PARAM_OP_NEW",
      "IPA_PARAM_OP_SPLIT"};
 
+/* Structure to hold declarations representing pass-through IPA-SRA splits.  In
+   essence, it tells new index for a combination of original index and
+   offset.  */
+
+struct pass_through_split_map
+{
+  /* Original argument index.  */
+  unsigned base_index;
+  /* Offset of the split part in the original argument.  */
+  unsigned unit_offset;
+  /* Index of the split part in the call statement - where clone
+     materialization put it.  */
+  int new_index;
+};
+
+/* Information about some call statements that needs to be conveyed from clone
+   materialization to edge redirection. */
+
+class ipa_edge_modification_info
+{
+ public:
+  ipa_edge_modification_info ()
+    {}
+
+  /* Mapping of original argument indices to where those arguments sit in the
+     call statement now or to a negative index if they were removed.  */
+  auto_vec<int> index_map;
+  /* Information about ISRA replacements put into the call statement at the
+     clone materialization stages.  */
+  auto_vec<pass_through_split_map> pass_through_map;
+  /* Necessary adjustment to ipa_param_adjustments::m_always_copy_start when
+     redirecting the call.  */
+  int always_copy_delta = 0;
+};
+
+/* Class for storing and retrieving summaries about cal statement
+   modifications.  */
+
+class ipa_edge_modification_sum
+  : public call_summary <ipa_edge_modification_info *>
+{
+ public:
+  ipa_edge_modification_sum (symbol_table *table)
+    : call_summary<ipa_edge_modification_info *> (table)
+  {
+  }
+
+  /* Hook that is called by summary when an edge is duplicated.  */
+
+  virtual void duplicate (cgraph_edge *,
+			  cgraph_edge *,
+			  ipa_edge_modification_info *old_info,
+			  ipa_edge_modification_info *new_info)
+  {
+    new_info->index_map.safe_splice (old_info->index_map);
+    new_info->pass_through_map.safe_splice (old_info->pass_through_map);
+    new_info->always_copy_delta = old_info->always_copy_delta;
+  }
+};
+
+/* Call summary to store information about edges which have had their arguments
+   partially modified already.  */
+
+static ipa_edge_modification_sum *ipa_edge_modifications;
+
+/* Fail compilation if CS has any summary associated with it in
+   ipa_edge_modifications.  */
+
+DEBUG_FUNCTION void
+ipa_verify_edge_has_no_modifications (cgraph_edge *cs)
+{
+  gcc_assert (!ipa_edge_modifications || !ipa_edge_modifications->get (cs));
+}
+
 /* Fill an empty vector ARGS with PARM_DECLs representing formal parameters of
    FNDECL.  The function should not be called during LTO WPA phase except for
    thunks (or functions with bodies streamed in). */
@@ -459,147 +533,46 @@  isra_get_ref_base_and_offset (tree expr, tree *base_p, unsigned *unit_offset_p)
   return true;
 }
 
-/* Return true if EXPR describes a transitive split (i.e. one that happened for
-   both the caller and the callee) as recorded in PERFORMED_SPLITS.  In that
-   case, store index of the respective record in PERFORMED_SPLITS into
-   *SM_IDX_P and the unit offset from all handled components in EXPR into
-   *UNIT_OFFSET_P.  */
-
-static bool
-transitive_split_p (vec<ipa_param_performed_split, va_gc> *performed_splits,
-		    tree expr, unsigned *sm_idx_p, unsigned *unit_offset_p)
-{
-  tree base;
-  if (!isra_get_ref_base_and_offset (expr, &base, unit_offset_p))
-    return false;
-
-  if (TREE_CODE (base) == SSA_NAME)
-    {
-      base = SSA_NAME_VAR (base);
-      if (!base)
-	return false;
-    }
-
-  unsigned len = vec_safe_length (performed_splits);
-  for (unsigned i = 0 ; i < len; i++)
-    {
-      ipa_param_performed_split *sm = &(*performed_splits)[i];
-      if (sm->dummy_decl == base)
-	{
-	  *sm_idx_p = i;
-	  return true;
-	}
-    }
-  return false;
-}
-
-/* Structure to hold declarations representing transitive IPA-SRA splits.  In
-   essence, if we need to pass UNIT_OFFSET of a parameter which originally has
-   number BASE_INDEX, we should pass down REPL.  */
-
-struct transitive_split_map
-{
-  tree repl;
-  unsigned base_index;
-  unsigned unit_offset;
-};
-
-/* If call STMT contains any parameters representing transitive splits as
-   described by PERFORMED_SPLITS, return the number of extra parameters that
-   were addded during clone materialization and fill in INDEX_MAP with adjusted
-   indices of corresponding original parameters and TRANS_MAP with description
-   of all transitive replacement descriptions.  Otherwise return zero. */
-
-static unsigned
-init_transitive_splits (vec<ipa_param_performed_split, va_gc> *performed_splits,
-			gcall *stmt, vec <unsigned> *index_map,
-			auto_vec <transitive_split_map> *trans_map)
-{
-  unsigned phony_arguments = 0;
-  unsigned stmt_idx = 0, base_index = 0;
-  unsigned nargs = gimple_call_num_args (stmt);
-  while (stmt_idx < nargs)
-    {
-      unsigned unit_offset_delta;
-      tree base_arg = gimple_call_arg (stmt, stmt_idx);
-
-      if (phony_arguments > 0)
-	index_map->safe_push (stmt_idx);
-
-      unsigned sm_idx;
-      stmt_idx++;
-      if (transitive_split_p (performed_splits, base_arg, &sm_idx,
-			      &unit_offset_delta))
-	{
-	  if (phony_arguments == 0)
-	    /* We have optimistically avoided constructing index_map do far but
-	       now it is clear it will be necessary, so let's create the easy
-	       bit we skipped until now.  */
-	    for (unsigned k = 0; k < stmt_idx; k++)
-	      index_map->safe_push (k);
-
-	  tree dummy = (*performed_splits)[sm_idx].dummy_decl;
-	  for (unsigned j = sm_idx; j < performed_splits->length (); j++)
-	    {
-	      ipa_param_performed_split *caller_split
-		= &(*performed_splits)[j];
-	      if (caller_split->dummy_decl != dummy)
-		break;
-
-	      tree arg = gimple_call_arg (stmt, stmt_idx);
-	      struct transitive_split_map tsm;
-	      tsm.repl = arg;
-	      tsm.base_index = base_index;
-	      if (caller_split->unit_offset >= unit_offset_delta)
-		{
-		  tsm.unit_offset
-		    = (caller_split->unit_offset - unit_offset_delta);
-		  trans_map->safe_push (tsm);
-		}
-
-	      phony_arguments++;
-	      stmt_idx++;
-	    }
-	}
-      base_index++;
-    }
-  return phony_arguments;
-}
-
-/* Modify actual arguments of a function call in statement STMT, assuming it
-   calls CALLEE_DECL.  CALLER_ADJ must be the description of parameter
-   adjustments of the caller or NULL if there are none.  Return the new
-   statement that replaced the old one.  When invoked, cfun and
-   current_function_decl have to be set to the caller.  */
+/* Modify actual arguments of a function call in statement currently belonging
+   to CS, and make it call CS->callee->decl.  Return the new statement that
+   replaced the old one.  When invoked, cfun and current_function_decl have to
+   be set to the caller.  */
 
 gcall *
-ipa_param_adjustments::modify_call (gcall *stmt,
-				    vec<ipa_param_performed_split,
-				        va_gc> *performed_splits,
-				    tree callee_decl, bool update_references)
+ipa_param_adjustments::modify_call (cgraph_edge *cs,
+				    bool update_references)
 {
+  gcall *stmt = cs->call_stmt;
+  tree callee_decl = cs->callee->decl;
+
+  ipa_edge_modification_info *mod_info
+    = ipa_edge_modifications ? ipa_edge_modifications->get (cs) : NULL;
+  if (mod_info && symtab->dump_file)
+    {
+      fprintf (symtab->dump_file, "Information about pre-exiting "
+	       "modifications.\n  Index map:");
+      unsigned idx_len = mod_info->index_map.length ();
+      for (unsigned i = 0; i < idx_len; i++)
+	fprintf (symtab->dump_file, " %i", mod_info->index_map[i]);
+      fprintf (symtab->dump_file, "\n  Pass-through split map: ");
+      unsigned ptm_len = mod_info->pass_through_map.length ();
+      for (unsigned i = 0; i < ptm_len; i++)
+	fprintf (symtab->dump_file,
+		 " (base_index: %u, offset: %u, new_index: %i)",
+		 mod_info->pass_through_map[i].base_index,
+		 mod_info->pass_through_map[i].unit_offset,
+		 mod_info->pass_through_map[i].new_index);
+      fprintf (symtab->dump_file, "\n  Always-copy delta: %i\n",
+	       mod_info->always_copy_delta);
+    }
+
   unsigned len = vec_safe_length (m_adj_params);
   auto_vec<tree, 16> vargs (len);
-  tree old_decl = gimple_call_fndecl (stmt);
   unsigned old_nargs = gimple_call_num_args (stmt);
+  unsigned orig_nargs = mod_info ? mod_info->index_map.length () : old_nargs;
   auto_vec<bool, 16> kept (old_nargs);
   kept.quick_grow_cleared (old_nargs);
 
-  auto_vec <unsigned, 16> index_map;
-  auto_vec <transitive_split_map> trans_map;
-  bool transitive_remapping = false;
-
-  if (performed_splits)
-    {
-      unsigned removed = init_transitive_splits (performed_splits,
-						 stmt, &index_map, &trans_map);
-      if (removed > 0)
-	{
-	  transitive_remapping = true;
-	  old_nargs -= removed;
-	}
-    }
-
   cgraph_node *current_node = cgraph_node::get (current_function_decl);
   if (update_references)
     current_node->remove_stmt_references (stmt);
@@ -612,13 +585,16 @@  ipa_param_adjustments::modify_call (gcall *stmt,
       ipa_adjusted_param *apm = &(*m_adj_params)[i];
       if (apm->op == IPA_PARAM_OP_COPY)
 	{
-	  unsigned index = apm->base_index;
-	  if (index >= old_nargs)
+	  int index = apm->base_index;
+	  if ((unsigned) index >= orig_nargs)
 	    /* Can happen if the original call has argument mismatch,
 	       ignore.  */
 	    continue;
-	  if (transitive_remapping)
-	    index = index_map[apm->base_index];
+	  if (mod_info)
+	    {
+	      index = mod_info->index_map[apm->base_index];
+	      gcc_assert (index >= 0);
+	    }
 
 	  tree arg = gimple_call_arg (stmt, index);
 
@@ -636,14 +612,17 @@  ipa_param_adjustments::modify_call (gcall *stmt,
 	 materialization.  */
       gcc_assert (apm->op == IPA_PARAM_OP_SPLIT);
 
-      /* We have to handle transitive changes differently using the maps we
-	 have created before.  So look into them first.  */
+      /* We have to handle pass-through changes differently using the map
+	 clone materialziation might have left behind.  */
       tree repl = NULL_TREE;
-      for (unsigned j = 0; j < trans_map.length (); j++)
-	if (trans_map[j].base_index == apm->base_index
-	    && trans_map[j].unit_offset == apm->unit_offset)
+      unsigned ptm_len = mod_info ? mod_info->pass_through_map.length () : 0;
+      for (unsigned j = 0; j < ptm_len; j++)
+	if (mod_info->pass_through_map[j].base_index == apm->base_index
+	    && mod_info->pass_through_map[j].unit_offset == apm->unit_offset)
 	  {
-	    repl = trans_map[j].repl;
+	    int repl_idx = mod_info->pass_through_map[j].new_index;
+	    gcc_assert (repl_idx >= 0);
+	    repl = gimple_call_arg (stmt, repl_idx);
 	    break;
 	  }
       if (repl)
@@ -652,12 +631,15 @@  ipa_param_adjustments::modify_call (gcall *stmt,
 	  continue;
 	}
 
-      unsigned index = apm->base_index;
-      if (index >= old_nargs)
+      int index = apm->base_index;
+      if ((unsigned) index >= orig_nargs)
 	/* Can happen if the original call has argument mismatch, ignore.  */
 	continue;
-      if (transitive_remapping)
-	index = index_map[apm->base_index];
+      if (mod_info)
+	{
+	  index = mod_info->index_map[apm->base_index];
+	  gcc_assert (index >= 0);
+	}
       tree base = gimple_call_arg (stmt, index);
 
       /* We create a new parameter out of the value of the old one, we can
@@ -773,8 +755,16 @@  ipa_param_adjustments::modify_call (gcall *stmt,
     }
 
   if (m_always_copy_start >= 0)
-    for (unsigned i = m_always_copy_start; i < old_nargs; i++)
-      vargs.safe_push (gimple_call_arg (stmt, i));
+    {
+      int always_copy_start = m_always_copy_start;
+      if (mod_info)
+	{
+	  always_copy_start += mod_info->always_copy_delta;
+	  gcc_assert (always_copy_start >= 0);
+	}
+      for (unsigned i = always_copy_start; i < old_nargs; i++)
+	vargs.safe_push (gimple_call_arg (stmt, i));
+    }
 
   /* For optimized away parameters, add on the caller side
      before the call
@@ -782,6 +772,7 @@  ipa_param_adjustments::modify_call (gcall *stmt,
      stmts and associate D#X with parm in decl_debug_args_lookup
      vector to say for debug info that if parameter parm had been passed,
      it would have value parm_Y(D).  */
+  tree old_decl = gimple_call_fndecl (stmt);
   if (MAY_HAVE_DEBUG_BIND_STMTS && old_decl && callee_decl)
     {
       vec<tree, va_gc> **debug_args = NULL;
@@ -799,13 +790,17 @@  ipa_param_adjustments::modify_call (gcall *stmt,
 	{
 	  if (!is_gimple_reg (old_parm) || kept[i])
 	    continue;
-	  tree origin = DECL_ORIGIN (old_parm);
 	  tree arg;
-	  if (transitive_remapping)
-	    arg = gimple_call_arg (stmt, index_map[i]);
+	  if (mod_info)
+	    {
+	      if (mod_info->index_map[i] < 0)
+		continue;
+	      arg = gimple_call_arg (stmt, mod_info->index_map[i]);
+	    }
 	  else
 	    arg = gimple_call_arg (stmt, i);
 
+	  tree origin = DECL_ORIGIN (old_parm);
 	  if (!useless_type_conversion_p (TREE_TYPE (origin), TREE_TYPE (arg)))
 	    {
 	      if (!fold_convertible_p (TREE_TYPE (origin), arg))
@@ -905,6 +900,9 @@  ipa_param_adjustments::modify_call (gcall *stmt,
 	gsi_prev (&gsi);
       }
     while (gsi_stmt (gsi) != gsi_stmt (prev_gsi));
+
+  if (mod_info)
+    ipa_edge_modifications->remove (cs);
   return new_stmt;
 }
 
@@ -927,13 +925,11 @@  ipa_param_adjustments::debug ()
   dump (stderr);
 }
 
-/* Register that REPLACEMENT should replace parameter described in APM and
-   optionally as DUMMY to mark transitive splits across calls.  */
+/* Register that REPLACEMENT should replace parameter described in APM.  */
 
 void
 ipa_param_body_adjustments::register_replacement (ipa_adjusted_param *apm,
-						  tree replacement,
-						  tree dummy)
+						  tree replacement)
 {
   gcc_checking_assert (apm->op == IPA_PARAM_OP_SPLIT
 		       || apm->op == IPA_PARAM_OP_NEW);
@@ -941,7 +937,6 @@  ipa_param_body_adjustments::register_replacement (ipa_adjusted_param *apm,
   ipa_param_body_replacement psr;
   psr.base = m_oparms[apm->prev_clone_index];
   psr.repl = replacement;
-  psr.dummy = dummy;
   psr.unit_offset = apm->unit_offset;
   m_replacements.safe_push (psr);
 }
@@ -970,6 +965,97 @@  ipa_param_body_adjustments::carry_over_param (tree t)
   return new_parm;
 }
 
+/* Return true if BLOCKS_TO_COPY is NULL or if PHI has an argument ARG in
+   position that corresponds to an edge that is coming from a block that has
+   the corresponding bit set in BLOCKS_TO_COPY.  */
+
+static bool
+phi_arg_will_live_p (gphi *phi, bitmap blocks_to_copy, tree arg)
+{
+  bool arg_will_survive = false;
+  if (!blocks_to_copy)
+    arg_will_survive = true;
+  else
+    for (unsigned i = 0; i < gimple_phi_num_args (phi); i++)
+      if (gimple_phi_arg_def (phi, i) == arg
+	  && bitmap_bit_p (blocks_to_copy,
+			   gimple_phi_arg_edge (phi, i)->src->index))
+	{
+	  arg_will_survive = true;
+	  break;
+	}
+  return arg_will_survive;
+}
+
+/* Populate m_dead_stmts given that DEAD_PARAM is going to be removed without
+   any replacement or splitting.  REPL is the replacement VAR_SECL to base any
+   remaining uses of a removed parameter on.  */
+
+void
+ipa_param_body_adjustments::mark_dead_statements (tree dead_param)
+{
+  /* Current IPA analyses which remove unused parameters never remove a
+     non-gimple register ones which have any use except as parameters in other
+     calls, so we can safely leve them as they are.  */
+  if (!is_gimple_reg (dead_param))
+    return;
+  tree parm_ddef = ssa_default_def (m_id->src_cfun, dead_param);
+  if (!parm_ddef || has_zero_uses (parm_ddef))
+    return;
+
+  auto_vec<tree, 4> stack;
+  m_dead_ssas.add (parm_ddef);
+  stack.safe_push (parm_ddef);
+  while (!stack.is_empty ())
+    {
+      tree t = stack.pop ();
+
+      imm_use_iterator imm_iter;
+      gimple *stmt;
+
+      insert_decl_map (m_id, t, error_mark_node);
+      FOR_EACH_IMM_USE_STMT (stmt, imm_iter, t)
+	{
+	  if (is_gimple_call (stmt)
+	      || (m_id->blocks_to_copy
+		  && !bitmap_bit_p (m_id->blocks_to_copy,
+				    gimple_bb (stmt)->index)))
+	    continue;
+
+	  if (is_gimple_debug (stmt))
+	    {
+	      m_dead_stmts.add (stmt);
+	      gcc_assert (gimple_debug_bind_p (stmt));
+	    }
+	  else if (gimple_code (stmt) == GIMPLE_PHI)
+	    {
+	      gphi *phi = as_a <gphi *> (stmt);
+	      if (phi_arg_will_live_p (phi, m_id->blocks_to_copy, t))
+		{
+		  m_dead_stmts.add (phi);
+		  tree res = gimple_phi_result (phi);
+		  if (!m_dead_ssas.add (res))
+		    stack.safe_push (res);
+		}
+	    }
+	  else if (is_gimple_assign (stmt))
+	    {
+	      m_dead_stmts.add (stmt);
+	      if (!gimple_clobber_p (stmt))
+		{
+		  tree lhs = gimple_assign_lhs (stmt);
+		  gcc_assert (TREE_CODE (lhs) == SSA_NAME);
+		  if (!m_dead_ssas.add (lhs))
+		    stack.safe_push (lhs);
+		}
+	    }
+	  else
+	    /* IPA-SRA does not analyze other types of statements.  */
+	    gcc_unreachable ();
+	}
+    }
+}
+
 /* Common initialization performed by all ipa_param_body_adjustments
    constructors.  OLD_FNDECL is the declaration we take original arguments
    from, (it may be the same as M_FNDECL).  VARS, if non-NULL, is a pointer to
@@ -1003,9 +1089,9 @@  ipa_param_body_adjustments::common_initialization (tree old_fndecl,
   auto_vec<bool, 16> kept;
   kept.reserve_exact (m_oparms.length ());
   kept.quick_grow_cleared (m_oparms.length ());
-  auto_vec<tree, 16> isra_dummy_decls;
-  isra_dummy_decls.reserve_exact (m_oparms.length ());
-  isra_dummy_decls.quick_grow_cleared (m_oparms.length ());
+  auto_vec<bool, 16> split;
+  split.reserve_exact (m_oparms.length ());
+  split.quick_grow_cleared (m_oparms.length ());
 
   unsigned adj_len = vec_safe_length (m_adj_params);
   m_method2func = ((TREE_CODE (TREE_TYPE (m_fndecl)) == METHOD_TYPE)
@@ -1051,35 +1137,8 @@  ipa_param_body_adjustments::common_initialization (tree old_fndecl,
 	  if (apm->op == IPA_PARAM_OP_SPLIT)
 	    {
 	      m_split_modifications_p = true;
-
-	      if (m_id)
-		{
-		  tree dummy_decl;
-		  if (!isra_dummy_decls[prev_index])
-		    {
-		      dummy_decl = copy_decl_to_var (m_oparms[prev_index],
-						     m_id);
-		      /* Any attempt to remap this dummy in this particular
-			 instance of clone materialization should yield
-			 itself.  */
-		      insert_decl_map (m_id, dummy_decl, dummy_decl);
-
-		      DECL_CHAIN (dummy_decl) = *vars;
-		      *vars = dummy_decl;
-		      isra_dummy_decls[prev_index] = dummy_decl;
-		    }
-		  else
-		    dummy_decl = isra_dummy_decls[prev_index];
-
-		  register_replacement (apm, new_parm, dummy_decl);
-		  ipa_param_performed_split ps;
-		  ps.dummy_decl = dummy_decl;
-		  ps.unit_offset = apm->unit_offset;
-		  vec_safe_push (clone_info::get_create
-				   (m_id->dst_node)->performed_splits, ps);
-		}
-	      else
-		register_replacement (apm, new_parm);
+	      split[prev_index] = true;
+	      register_replacement (apm, new_parm);
 	    }
         }
       else
@@ -1106,13 +1165,16 @@  ipa_param_body_adjustments::common_initialization (tree old_fndecl,
 	  {
 	    if (!m_id->decl_map->get (m_oparms[i]))
 	      {
-		/* TODO: Perhaps at least aggregate-type params could re-use
-		   their isra_dummy_decl here?  */
 		tree var = copy_decl_to_var (m_oparms[i], m_id);
 		insert_decl_map (m_id, m_oparms[i], var);
 		/* Declare this new variable.  */
 		DECL_CHAIN (var) = *vars;
 		*vars = var;
+
+		/* If this is not a split but a real removal, init hash sets
+		   that will guide what not to copy to the new body.  */
+		if (!split[i])
+		  mark_dead_statements (m_oparms[i]);
 	      }
 	  }
 	else
@@ -1169,9 +1231,10 @@  ipa_param_body_adjustments
 ::ipa_param_body_adjustments (vec<ipa_adjusted_param, va_gc> *adj_params,
 			      tree fndecl)
   : m_adj_params (adj_params), m_adjustments (NULL), m_reset_debug_decls (),
-    m_split_modifications_p (false), m_fndecl (fndecl), m_id (NULL),
-    m_oparms (), m_new_decls (), m_new_types (), m_replacements (),
-    m_removed_decls (), m_removed_map (), m_method2func (false)
+    m_split_modifications_p (false), m_dead_stmts (), m_dead_ssas (),
+    m_fndecl (fndecl), m_id (NULL), m_oparms (), m_new_decls (),
+    m_new_types (), m_replacements (), m_removed_decls (), m_removed_map (),
+    m_method2func (false), m_new_call_arg_modification_info (false)
 {
   common_initialization (fndecl, NULL, NULL);
 }
@@ -1185,10 +1248,10 @@  ipa_param_body_adjustments
 ::ipa_param_body_adjustments (ipa_param_adjustments *adjustments,
 			      tree fndecl)
   : m_adj_params (adjustments->m_adj_params), m_adjustments (adjustments),
-    m_reset_debug_decls (), m_split_modifications_p (false), m_fndecl (fndecl),
-    m_id (NULL), m_oparms (), m_new_decls (), m_new_types (),
-    m_replacements (), m_removed_decls (), m_removed_map (),
-    m_method2func (false)
+    m_reset_debug_decls (), m_split_modifications_p (false), m_dead_stmts (),
+    m_dead_ssas (), m_fndecl (fndecl), m_id (NULL), m_oparms (), m_new_decls (),
+    m_new_types (), m_replacements (), m_removed_decls (), m_removed_map (),
+    m_method2func (false), m_new_call_arg_modification_info (false)
 {
   common_initialization (fndecl, NULL, NULL);
 }
@@ -1208,9 +1271,10 @@  ipa_param_body_adjustments
 			      copy_body_data *id, tree *vars,
 			      vec<ipa_replace_map *, va_gc> *tree_map)
   : m_adj_params (adjustments->m_adj_params), m_adjustments (adjustments),
-    m_reset_debug_decls (), m_split_modifications_p (false), m_fndecl (fndecl),
-    m_id (id), m_oparms (), m_new_decls (), m_new_types (), m_replacements (),
-    m_removed_decls (), m_removed_map (), m_method2func (false)
+    m_reset_debug_decls (), m_split_modifications_p (false), m_dead_stmts (),
+    m_dead_ssas (),m_fndecl (fndecl), m_id (id), m_oparms (), m_new_decls (),
+    m_new_types (), m_replacements (), m_removed_decls (), m_removed_map (),
+    m_method2func (false), m_new_call_arg_modification_info (false)
 {
   common_initialization (old_fndecl, vars, tree_map);
 }
@@ -1498,218 +1562,338 @@  ipa_param_body_adjustments::modify_assignment (gimple *stmt,
   return any;
 }
 
-/* Data passed to remap_split_decl_to_dummy through walk_tree.  */
+/* Record information about what modifications to call arguments have already
+   been done by clone materialization into a summary describing CS.  The
+   information is stored in NEW_INDEX_MAP, NEW_PT_MAP and NEW_ALWAYS_COPY_DELTA
+   and correspond to equivalent fields in ipa_edge_modification_info.  Return
+   the edge summary.  */
+
+static ipa_edge_modification_info *
+record_argument_state_1 (cgraph_edge *cs, const vec<int> &new_index_map,
+			 const vec<pass_through_split_map> &new_pt_map,
+			 int new_always_copy_delta)
 
-struct simple_tree_swap_info
 {
-  /* Change FROM to TO.  */
-  tree from, to;
-  /* And set DONE to true when doing so.  */
-  bool done;
-};
+  ipa_edge_modification_info *sum = ipa_edge_modifications->get_create (cs);
 
-/* Simple remapper to remap a split parameter to the same expression based on a
-   special dummy decl so that edge redirections can detect transitive splitting
-   and finish them.  */
-
-static tree
-remap_split_decl_to_dummy (tree *tp, int *walk_subtrees, void *data)
-{
-  tree t = *tp;
-
-  if (DECL_P (t) || TREE_CODE (t) == SSA_NAME)
+  unsigned len = sum->pass_through_map.length ();
+  for (unsigned i = 0; i < len; i++)
     {
-      struct simple_tree_swap_info *swapinfo
-	= (struct simple_tree_swap_info *) data;
-      if (t == swapinfo->from
-	  || (TREE_CODE (t) == SSA_NAME
-	      && SSA_NAME_VAR (t) == swapinfo->from))
-	{
-	  *tp = swapinfo->to;
-	  swapinfo->done = true;
-	}
-      *walk_subtrees = 0;
+      unsigned oldnew = sum->pass_through_map[i].new_index;
+      sum->pass_through_map[i].new_index = new_index_map[oldnew];
+    }
+
+  len = sum->index_map.length ();
+  if (len > 0)
+    {
+      unsigned nptlen = new_pt_map.length ();
+      for (unsigned j = 0; j < nptlen; j++)
+	{
+	  int inverse = -1;
+	  for (unsigned i = 0; i < len ; i++)
+	    if ((unsigned) sum->index_map[i] == new_pt_map[j].base_index)
+	    {
+	      inverse = i;
+	      break;
+	    }
+	  gcc_assert (inverse >= 0);
+	  pass_through_split_map ptm_item;
+
+	  ptm_item.base_index = inverse;
+	  ptm_item.unit_offset = new_pt_map[j].unit_offset;
+	  ptm_item.new_index = new_pt_map[j].new_index;
+	  sum->pass_through_map.safe_push (ptm_item);
+	}
+
+      for (unsigned i = 0; i < len; i++)
+	{
+	  int idx = sum->index_map[i];
+	  if (idx < 0)
+	    continue;
+	  sum->index_map[i] = new_index_map[idx];
+	}
     }
-  else if (TYPE_P (t))
-      *walk_subtrees = 0;
   else
-    *walk_subtrees = 1;
-  return NULL_TREE;
+    {
+      sum->pass_through_map.safe_splice (new_pt_map);
+      sum->index_map.safe_splice (new_index_map);
+    }
+  sum->always_copy_delta += new_always_copy_delta;
+  return sum;
 }
 
+/* Record information about what modifications to call arguments have already
+   been done by clone materialization into a summary of an edge describing the
+   call in this clone and all its clones.  NEW_INDEX_MAP, NEW_PT_MAP and
+   NEW_ALWAYS_COPY_DELTA have the same meaning as record_argument_state_1.
+
+   In order to associate the info with the right edge summaries, we need
+   address of the ORIG_STMT in the function from which we are cloning (because
+   the edges have not yet been re-assigned to the new statement that has just
+   been created) and ID, the structure governing function body copying.  */
+
+static void
+record_argument_state (copy_body_data *id, gimple *orig_stmt,
+		       const vec<int> &new_index_map,
+		       const vec<pass_through_split_map> &new_pt_map,
+		       int new_always_copy_delta)
+{
+  if (!ipa_edge_modifications)
+    ipa_edge_modifications = new ipa_edge_modification_sum (symtab);
+
+  struct cgraph_node *this_node = id->dst_node;
+  ipa_edge_modification_info *first_sum = NULL;
+  cgraph_edge *cs = this_node->get_edge (orig_stmt);
+  if (cs)
+    first_sum = record_argument_state_1 (cs, new_index_map, new_pt_map,
+					 new_always_copy_delta);
+  else
+    gcc_assert (this_node->clones);
+
+  if (!this_node->clones)
+    return;
+  for (cgraph_node *subclone = this_node->clones; subclone != this_node;)
+    {
+      cs = subclone->get_edge (orig_stmt);
+      if (cs)
+	{
+	  if (!first_sum)
+	    first_sum = record_argument_state_1 (cs, new_index_map, new_pt_map,
+						 new_always_copy_delta);
+	  else
+	    {
+	      ipa_edge_modification_info *s2
+		= ipa_edge_modifications->get_create (cs);
+	      s2->index_map.truncate (0);
+	      s2->index_map.safe_splice (first_sum->index_map);
+	      s2->pass_through_map.truncate (0);
+	      s2->pass_through_map.safe_splice (first_sum->pass_through_map);
+	      s2->always_copy_delta = first_sum->always_copy_delta;
+	    }
+	}
+      else
+	gcc_assert (subclone->clones);
+
+      if (subclone->clones)
+	subclone = subclone->clones;
+      else if (subclone->next_sibling_clone)
+	subclone = subclone->next_sibling_clone;
+      else
+	{
+	  while (subclone != this_node && !subclone->next_sibling_clone)
+	    subclone = subclone->clone_of;
+	  if (subclone != this_node)
+	    subclone = subclone->next_sibling_clone;
+	}
+    }
+}
 
 /* If the call statement pointed at by STMT_P contains any expressions that
    need to replaced with a different one as noted by ADJUSTMENTS, do so.  f the
    statement needs to be rebuilt, do so.  Return true if any modifications have
-   been performed.
+   been performed.  ORIG_STMT, if not NULL, is the original statement in the
+   function that is being cloned from, which at this point can be used to look
+   up call_graph edges.
 
    If the method is invoked as a part of IPA clone materialization and if any
-   parameter split is transitive, i.e. it applies to the functin that is being
-   modified and also to the callee of the statement, replace the parameter
-   passed to old callee with an equivalent expression based on a dummy decl
-   followed by PARM_DECLs representing the actual replacements.  The actual
-   replacements will be then converted into SSA_NAMEs and then
-   ipa_param_adjustments::modify_call will find the appropriate ones and leave
-   only those in the call.  */
+   parameter split is pass-through, i.e. it applies to the functin that is
+   being modified and also to the callee of the statement, replace the
+   parameter passed to old callee with all of the replacement a callee might
+   possibly want and record the performed argument modifications in
+   ipa_edge_modifications.  Likewise if any argument has already been left out
+   because it is not necessary.  */
 
 bool
-ipa_param_body_adjustments::modify_call_stmt (gcall **stmt_p)
+ipa_param_body_adjustments::modify_call_stmt (gcall **stmt_p,
+					      gimple *orig_stmt)
 {
-  gcall *stmt = *stmt_p;
   auto_vec <unsigned, 4> pass_through_args;
   auto_vec <unsigned, 4> pass_through_pbr_indices;
+  auto_vec <HOST_WIDE_INT, 4> pass_through_offsets;
+  gcall *stmt = *stmt_p;
+  unsigned nargs = gimple_call_num_args (stmt);
+  bool recreate = false;
 
-  if (m_split_modifications_p && m_id)
+  for (unsigned i = 0; i < gimple_call_num_args (stmt); i++)
     {
-      for (unsigned i = 0; i < gimple_call_num_args (stmt); i++)
+      tree t = gimple_call_arg (stmt, i);
+      gcc_assert (TREE_CODE (t) != BIT_FIELD_REF
+		  && TREE_CODE (t) != IMAGPART_EXPR
+		  && TREE_CODE (t) != REALPART_EXPR);
+
+      if (TREE_CODE (t) == SSA_NAME
+	  && m_dead_ssas.contains (t))
+	recreate = true;
+
+      if (!m_split_modifications_p)
+	continue;
+
+      tree base;
+      unsigned agg_arg_offset;
+      if (!isra_get_ref_base_and_offset (t, &base, &agg_arg_offset))
+	continue;
+
+      bool by_ref = false;
+      if (TREE_CODE (base) == SSA_NAME)
 	{
-	  tree t = gimple_call_arg (stmt, i);
-	  gcc_assert (TREE_CODE (t) != BIT_FIELD_REF
-		      && TREE_CODE (t) != IMAGPART_EXPR
-		      && TREE_CODE (t) != REALPART_EXPR);
-
-	  tree base;
-	  unsigned unit_offset;
-	  if (!isra_get_ref_base_and_offset (t, &base, &unit_offset))
+	  if (!SSA_NAME_IS_DEFAULT_DEF (base))
 	    continue;
+	  base = SSA_NAME_VAR (base);
+	  gcc_checking_assert (base);
+	  by_ref = true;
+	}
+      if (TREE_CODE (base) != PARM_DECL)
+	continue;
 
-	  bool by_ref = false;
-	  if (TREE_CODE (base) == SSA_NAME)
+      bool base_among_replacements = false;
+      unsigned j, repl_list_len = m_replacements.length ();
+      for (j = 0; j < repl_list_len; j++)
+	{
+	  ipa_param_body_replacement *pbr = &m_replacements[j];
+	  if (pbr->base == base)
 	    {
-	      if (!SSA_NAME_IS_DEFAULT_DEF (base))
-		continue;
-	      base = SSA_NAME_VAR (base);
-	      gcc_checking_assert (base);
-	      by_ref = true;
+	      base_among_replacements = true;
+	      break;
 	    }
-	  if (TREE_CODE (base) != PARM_DECL)
-	    continue;
+	}
+      if (!base_among_replacements)
+	continue;
 
-	  bool base_among_replacements = false;
-	  unsigned j, repl_list_len = m_replacements.length ();
-	  for (j = 0; j < repl_list_len; j++)
+      /* We still have to distinguish between an end-use that we have to
+	 transform now and a pass-through, which happens in the following
+	 two cases.  */
+
+      /* TODO: After we adjust ptr_parm_has_nonarg_uses to also consider
+	 &MEM_REF[ssa_name + offset], we will also have to detect that case
+	 here.    */
+
+      if (TREE_CODE (t) == SSA_NAME
+	  && SSA_NAME_IS_DEFAULT_DEF (t)
+	  && SSA_NAME_VAR (t)
+	  && TREE_CODE (SSA_NAME_VAR (t)) == PARM_DECL)
+	{
+	  /* This must be a by_reference pass-through.  */
+	  recreate = true;
+	  gcc_assert (POINTER_TYPE_P (TREE_TYPE (t)));
+	  pass_through_args.safe_push (i);
+	  pass_through_pbr_indices.safe_push (j);
+	  pass_through_offsets.safe_push (agg_arg_offset);
+	}
+      else if (!by_ref && AGGREGATE_TYPE_P (TREE_TYPE (t)))
+	{
+	  /* Currently IPA-SRA guarantees the aggregate access type
+	     exactly matches in this case.  So if it does not match, it is
+	     a pass-through argument that will be sorted out at edge
+	     redirection time.  */
+	  ipa_param_body_replacement *pbr
+	    = lookup_replacement_1 (base, agg_arg_offset);
+
+	  if (!pbr
+	      || (TYPE_MAIN_VARIANT (TREE_TYPE (t))
+		  != TYPE_MAIN_VARIANT (TREE_TYPE (pbr->repl))))
 	    {
-	      ipa_param_body_replacement *pbr = &m_replacements[j];
-	      if (pbr->base == base)
-		{
-		  base_among_replacements = true;
-		  break;
-		}
-	    }
-	  if (!base_among_replacements)
-	    continue;
-
-	  /* We still have to distinguish between an end-use that we have to
-	     transform now and a pass-through, which happens in the following
-	     two cases.  */
-
-	  /* TODO: After we adjust ptr_parm_has_nonarg_uses to also consider
-	     &MEM_REF[ssa_name + offset], we will also have to detect that case
-	     here.    */
-
-	  if (TREE_CODE (t) == SSA_NAME
-	      && SSA_NAME_IS_DEFAULT_DEF (t)
-	      && SSA_NAME_VAR (t)
-	      && TREE_CODE (SSA_NAME_VAR (t)) == PARM_DECL)
-	    {
-	      /* This must be a by_reference pass-through.  */
-	      gcc_assert (POINTER_TYPE_P (TREE_TYPE (t)));
+	      recreate = true;
 	      pass_through_args.safe_push (i);
 	      pass_through_pbr_indices.safe_push (j);
-	    }
-	  else if (!by_ref && AGGREGATE_TYPE_P (TREE_TYPE (t)))
-	    {
-	      /* Currently IPA-SRA guarantees the aggregate access type
-		 exactly matches in this case.  So if it does not match, it is
-		 a pass-through argument that will be sorted out at edge
-		 redirection time.  */
-	      ipa_param_body_replacement *pbr
-		= lookup_replacement_1 (base, unit_offset);
-
-	      if (!pbr
-		  || (TYPE_MAIN_VARIANT (TREE_TYPE (t))
-		      != TYPE_MAIN_VARIANT (TREE_TYPE (pbr->repl))))
-		{
-		  pass_through_args.safe_push (i);
-		  pass_through_pbr_indices.safe_push (j);
-		}
+	      pass_through_offsets.safe_push (agg_arg_offset);
 	    }
 	}
     }
 
-  unsigned nargs = gimple_call_num_args (stmt);
-  if (!pass_through_args.is_empty ())
+  if (!recreate)
     {
-      auto_vec<tree, 16> vargs;
-      unsigned pt_idx = 0;
+      /* No need to rebuild the statement, let's just modify arguments
+	 and the LHS if/as appropriate.  */
+      bool modified = false;
       for (unsigned i = 0; i < nargs; i++)
 	{
-	  if (pt_idx < pass_through_args.length ()
-	      && i == pass_through_args[pt_idx])
-	    {
-	      unsigned j = pass_through_pbr_indices[pt_idx];
-	      pt_idx++;
-	      tree base = m_replacements[j].base;
+	  tree *t = gimple_call_arg_ptr (stmt, i);
+	  modified |= modify_expression (t, true);
+	}
+      if (gimple_call_lhs (stmt))
+	{
+	  tree *t = gimple_call_lhs_ptr (stmt);
+	  modified |= modify_expression (t, false);
+	}
+      return modified;
+    }
 
-	      /* Map base will get mapped to the special transitive-isra marker
-		 dummy decl. */
-	      struct simple_tree_swap_info swapinfo;
-	      swapinfo.from = base;
-	      swapinfo.to = m_replacements[j].dummy;
-	      swapinfo.done = false;
-	      tree arg = gimple_call_arg (stmt, i);
-	      walk_tree (&arg, remap_split_decl_to_dummy, &swapinfo, NULL);
-	      gcc_assert (swapinfo.done);
-	      vargs.safe_push (arg);
-	      /* Now let's push all replacements pertaining to this parameter
-		 so that all gimple register ones get correct SSA_NAMES.  Edge
-		 redirection will weed out the dummy argument as well as all
-		 unused replacements later.  */
-	      unsigned int repl_list_len = m_replacements.length ();
-	      for (; j < repl_list_len; j++)
-		{
-		  if (m_replacements[j].base != base)
-		    break;
-		  vargs.safe_push (m_replacements[j].repl);
-		}
+  auto_vec<int, 16> index_map;
+  auto_vec<pass_through_split_map, 4> pass_through_map;
+  auto_vec<tree, 16> vargs;
+  int always_copy_delta = 0;
+  unsigned pt_idx = 0;
+  int new_arg_idx = 0;
+  for (unsigned i = 0; i < nargs; i++)
+    {
+      if (pt_idx < pass_through_args.length ()
+	  && i == pass_through_args[pt_idx])
+	{
+	  unsigned j = pass_through_pbr_indices[pt_idx];
+	  unsigned agg_arg_offset = pass_through_offsets[pt_idx];
+	  pt_idx++;
+	  always_copy_delta--;
+	  tree base = m_replacements[j].base;
+
+	  /* In order to be put into SSA form, we have to push all replacements
+	     pertaining to this parameter as parameters to the call statement.
+	     Edge redirection will need to use edge summary to weed out the
+	     unnecessary ones.  */
+	  unsigned repl_list_len = m_replacements.length ();
+	  for (; j < repl_list_len; j++)
+	    {
+	      if (m_replacements[j].base != base)
+		break;
+	      if (m_replacements[j].unit_offset < agg_arg_offset)
+		continue;
+	      pass_through_split_map pt_map;
+	      pt_map.base_index = i;
+	      pt_map.unit_offset
+		= m_replacements[j].unit_offset - agg_arg_offset;
+	      pt_map.new_index = new_arg_idx;
+	      pass_through_map.safe_push (pt_map);
+	      vargs.safe_push (m_replacements[j].repl);
+	      new_arg_idx++;
+	      always_copy_delta++;
+	    }
+	  index_map.safe_push (-1);
+	}
+      else
+	{
+	  tree t = gimple_call_arg (stmt, i);
+	  if (TREE_CODE (t) == SSA_NAME
+	      && m_dead_ssas.contains (t))
+	    {
+	      always_copy_delta--;
+	      index_map.safe_push (-1);
 	    }
 	  else
 	    {
-	      tree t = gimple_call_arg (stmt, i);
 	      modify_expression (&t, true);
 	      vargs.safe_push (t);
+	      index_map.safe_push (new_arg_idx);
+	      new_arg_idx++;
 	    }
 	}
-      gcall *new_stmt = gimple_build_call_vec (gimple_call_fn (stmt), vargs);
-      if (gimple_has_location (stmt))
-	gimple_set_location (new_stmt, gimple_location (stmt));
-      gimple_call_set_chain (new_stmt, gimple_call_chain (stmt));
-      gimple_call_copy_flags (new_stmt, stmt);
-      if (tree lhs = gimple_call_lhs (stmt))
-	{
-	  modify_expression (&lhs, false);
-	  gimple_call_set_lhs (new_stmt, lhs);
-	}
-      *stmt_p = new_stmt;
-      return true;
     }
 
-  /* Otherwise, no need to rebuild the statement, let's just modify arguments
-     and the LHS if/as appropriate.  */
-  bool modified = false;
-  for (unsigned i = 0; i < nargs; i++)
+  gcall *new_stmt = gimple_build_call_vec (gimple_call_fn (stmt), vargs);
+  if (gimple_has_location (stmt))
+    gimple_set_location (new_stmt, gimple_location (stmt));
+  gimple_call_set_chain (new_stmt, gimple_call_chain (stmt));
+  gimple_call_copy_flags (new_stmt, stmt);
+  if (tree lhs = gimple_call_lhs (stmt))
     {
-      tree *t = gimple_call_arg_ptr (stmt, i);
-      modified |= modify_expression (t, true);
+      modify_expression (&lhs, false);
+      gimple_call_set_lhs (new_stmt, lhs);
     }
+  *stmt_p = new_stmt;
 
-  if (gimple_call_lhs (stmt))
-    {
-      tree *t = gimple_call_lhs_ptr (stmt);
-      modified |= modify_expression (t, false);
-    }
-
-  return modified;
+  m_new_call_arg_modification_info = true;
+  if (orig_stmt)
+    record_argument_state (m_id, orig_stmt, index_map, pass_through_map,
+			   always_copy_delta);
+  return true;
 }
 
 /* If the statement STMT contains any expressions that need to replaced with a
@@ -1720,7 +1904,8 @@  ipa_param_body_adjustments::modify_call_stmt (gcall **stmt_p)
 
 bool
 ipa_param_body_adjustments::modify_gimple_stmt (gimple **stmt,
-						gimple_seq *extra_stmts)
+						gimple_seq *extra_stmts,
+						gimple *orig_stmt)
 {
   bool modified = false;
   tree *t;
@@ -1740,7 +1925,7 @@  ipa_param_body_adjustments::modify_gimple_stmt (gimple **stmt,
       break;
 
     case GIMPLE_CALL:
-      modified |= modify_call_stmt ((gcall **) stmt);
+      modified |= modify_call_stmt ((gcall **) stmt, orig_stmt);
       break;
 
     case GIMPLE_ASM:
@@ -1797,7 +1982,7 @@  ipa_param_body_adjustments::modify_cfun_body ()
 	  gimple *stmt = gsi_stmt (gsi);
 	  gimple *stmt_copy = stmt;
 	  gimple_seq extra_stmts = NULL;
-	  bool modified = modify_gimple_stmt (&stmt, &extra_stmts);
+	  bool modified = modify_gimple_stmt (&stmt, &extra_stmts, NULL);
 	  if (stmt != stmt_copy)
 	    {
 	      gcc_checking_assert (modified);
@@ -1945,4 +2130,3 @@  ipa_param_body_adjustments::perform_cfun_body_modifications ()
 
   return cfg_changed;
 }
-
diff --git a/gcc/ipa-param-manipulation.h b/gcc/ipa-param-manipulation.h
index c80e1bc5d6b..f59d17717ee 100644
--- a/gcc/ipa-param-manipulation.h
+++ b/gcc/ipa-param-manipulation.h
@@ -54,7 +54,7 @@  or only a vector of ipa_adjusted_params.
 When these classes are used in the context of call graph clone materialization
 and subsequent call statement redirection - which is the point at which we
 modify arguments in call statements - they need to cooperate with each other in
-order to handle what we refer to as transitive (IPA-SRA) splits.  These are
+order to handle what we refer to as pass-through (IPA-SRA) splits.  These are
 situations when a formal parameter of one function is split into several
 smaller ones and some of them are then passed on in a call to another function
 because the formal parameter of this callee has also been split.
@@ -83,7 +83,7 @@  baz ()
 Both bar and foo would have their parameter split.  Foo would receive one
 replacement representing s.b.  Function bar would see its parameter split into
 one replacement representing z.s.a and another representing z.s.b which would
-be passed on to foo.  It would be a so called transitive split IPA-SRA
+be passed on to foo.  It would be a so called pass-through split IPA-SRA
 replacement, one which is passed in a call as an actual argument to another
 IPA-SRA replacement in another function.
 
@@ -95,30 +95,25 @@  all of the above.
 
 Call redirection has to be able to find the right decl or SSA_NAME that
 corresponds to the transitive split in the caller.  The SSA names are assigned
-right after clone materialization/ modification and cannot be "added"
-afterwards.  Moreover, if the caller has been inlined the SSA_NAMEs in question
-no longer belong to PARM_DECLs but to VAR_DECLs, indistinguishable from any
-others.
+right after clone materialization/ modification and cannot be "added" to call
+arguments at any later point.  Moreover, if the caller has been inlined the
+SSA_NAMEs in question no longer belong to PARM_DECLs but to VAR_DECLs,
+indistinguishable from any others.
 
 Therefore, when clone materialization finds a call statement which it knows is
-a part of a transitive split, it will modify it into:
+a part of a transitive split, it will simply add as arguments all new "split"
+replacements (that have grater or equal offset than the original call
+argument):
 
-  foo (DUMMY_Z_VAR.s, repl_for_a, repl_for_b, <rest of original arguments>);
+  foo (repl_for_a, repl_for_b, <rest of original arguments>);
 
-It will also store {DUMMY_S_VAR, 32} and {DUMMY_S_VAR, 64} representing offsets
-of z.s.a and z.s.b (assuming a 32-bit int) into foo's cgraph node
-clone->performed_splits vector (which is storing structures of type
-ipa_param_performed_split also defined in this header file).
-
-Call redirection will identify that expression DUMMY_Z_VAR.s is based on a
-variable stored in performed_splits vector and learn that the following
-arguments, already in SSA form, represent offsets 32 and 64 in a split original
-parameter.  It subtracts offset of DUMMY_Z_VAR.s from 32 and 64 and arrives at
-offsets 0 and 32 within callee's original parameter.  At this point it also
-knows from the call graph that only the bit with offset 32 is needed and so
-changes the call statement into final:
-
-bar (repl_for_b, <rest of original arguments>);  */
+It will also store into ipa_edge_modification_info (which is internal to
+ipa-param-modification.c) information about which replacement is which and
+where original arguments are.  Call redirection will then invoke
+ipa_param_adjustments::modify_call which will access this information and
+eliminate all replacements which the callee does not expect (repl_for_a in our
+example above).  In between these two steps, however, a call statement might
+have extraneous arguments.  */
 
 #ifndef IPA_PARAM_MANIPULATION_H
 #define IPA_PARAM_MANIPULATION_H
@@ -207,21 +202,6 @@  struct GTY(()) ipa_adjusted_param
 void ipa_dump_adjusted_parameters (FILE *f,
 				   vec<ipa_adjusted_param, va_gc> *adj_params);
 
-/* Structure to remember the split performed on a node so that edge redirection
-   (i.e. splitting arguments of call statements) know how split formal
-   parameters of the caller are represented.  */
-
-struct GTY(()) ipa_param_performed_split
-{
-  /* The dummy VAR_DECL that was created instead of the split parameter that
-     sits in the call in the meantime between clone materialization and call
-     redirection.  All entries in a vector of performed splits that correspond
-     to the same dumy decl must be grouped together.  */
-  tree dummy_decl;
-  /* Offset into the original parameter.  */
-  unsigned unit_offset;
-};
-
 /* Class used to record planned modifications to parameters of a function and
    also to perform necessary modifications at the caller side at the gimple
    level.  Used to describe all cgraph node clones that have their parameters
@@ -244,9 +224,7 @@  public:
 
   /* Modify a call statement arguments (and possibly remove the return value)
      as described in the data fields of this class.  */
-  gcall *modify_call (gcall *stmt,
-		      vec<ipa_param_performed_split, va_gc> *performed_splits,
-		      tree callee_decl, bool update_references);
+  gcall *modify_call (cgraph_edge *cs, bool update_references);
   /* Return if the first parameter is left intact.  */
   bool first_param_intact_p ();
   /* Build a function type corresponding to the modified call.  */
@@ -293,15 +271,9 @@  struct ipa_param_body_replacement
   tree base;
   /* The new decl it should be replaced with.  */
   tree repl;
-  /* When modifying clones during IPA clone materialization, this is a dummy
-     decl used to mark calls in which we need to apply transitive splitting,
-     these dummy delcls are inserted as arguments to such calls and then
-     followed by all the replacements with offset info stored in
-     ipa_param_performed_split.
-
-     Users of ipa_param_body_adjustments that modify standalone functions
-     outside of IPA clone materialization can use this field for their internal
-     purposes.  */
+  /* Users of ipa_param_body_adjustments that modify standalone functions
+     outside of IPA clone materialization can use the following field for their
+     internal purposes.  */
   tree dummy;
   /* The offset within BASE that REPL represents.  */
   unsigned unit_offset;
@@ -342,8 +314,7 @@  public:
   /* Change the PARM_DECLs.  */
   void modify_formal_parameters ();
   /* Register a replacement decl for the transformation done in APM.  */
-  void register_replacement (ipa_adjusted_param *apm, tree replacement,
-			     tree dummy = NULL_TREE);
+  void register_replacement (ipa_adjusted_param *apm, tree replacement);
   /* Lookup a replacement for a given offset within a given parameter.  */
   tree lookup_replacement (tree base, unsigned unit_offset);
   /* Lookup a replacement for an expression, if there is one.  */
@@ -353,7 +324,8 @@  public:
      parameter. */
   tree get_replacement_ssa_base (tree old_decl);
   /* Modify a statement.  */
-  bool modify_gimple_stmt (gimple **stmt, gimple_seq *extra_stmts);
+  bool modify_gimple_stmt (gimple **stmt, gimple_seq *extra_stmts,
+			   gimple *orig_stmt);
   /* Return the new chain of parameters.  */
   tree get_new_param_chain ();
 
@@ -370,6 +342,12 @@  public:
   /* Set to true if there are any IPA_PARAM_OP_SPLIT adjustments among stored
      adjustments.  */
   bool m_split_modifications_p;
+
+  /* Sets of statements and SSA_NAMEs that only manipulate data from parameters
+     removed because they are not necessary.  */
+  hash_set<gimple *> m_dead_stmts;
+  hash_set<tree> m_dead_ssas;
+
 private:
   void common_initialization (tree old_fndecl, tree *vars,
 			      vec<ipa_replace_map *, va_gc> *tree_map);
@@ -380,9 +358,10 @@  private:
   tree replace_removed_params_ssa_names (tree old_name, gimple *stmt);
   bool modify_expression (tree *expr_p, bool convert);
   bool modify_assignment (gimple *stmt, gimple_seq *extra_stmts);
-  bool modify_call_stmt (gcall **stmt_p);
+  bool modify_call_stmt (gcall **stmt_p, gimple *orig_stmt);
   bool modify_cfun_body ();
   void reset_debug_stmts ();
+  void mark_dead_statements (tree dead_param);
 
   /* Declaration of the function that is being transformed.  */
 
@@ -427,9 +406,16 @@  private:
      its this pointer and must be converted to a normal function.  */
 
   bool m_method2func;
+
+  /* Set to true if any new information has been stored to
+     ipa_edge_modifications as part of this body transformation.  */
+
+  bool m_new_call_arg_modification_info;
 };
 
 void push_function_arg_decls (vec<tree> *args, tree fndecl);
 void push_function_arg_types (vec<tree> *types, tree fntype);
+void ipa_verify_edge_has_no_modifications (cgraph_edge *cs);
+
 
 #endif	/* IPA_PARAM_MANIPULATION_H */
diff --git a/gcc/symtab-clones.h b/gcc/symtab-clones.h
index 5695a434f6a..a6ad4a6e27f 100644
--- a/gcc/symtab-clones.h
+++ b/gcc/symtab-clones.h
@@ -26,8 +26,7 @@  struct GTY(()) clone_info
   /* Constructor.  */
   clone_info ()
     : tree_map (NULL),
-      param_adjustments (NULL),
-      performed_splits (NULL)
+      param_adjustments (NULL)
   {
   }
   /* Constants discovered by IPA-CP, i.e. which parameter should be replaced
@@ -35,18 +34,6 @@  struct GTY(()) clone_info
   vec<ipa_replace_map *, va_gc> *tree_map;
   /* Parameter modification that IPA-SRA decided to perform.  */
   ipa_param_adjustments *param_adjustments;
-  /* Lists of dummy-decl and offset pairs representing split formal parameters
-     in the caller.  Offsets of all new replacements are enumerated, those
-     coming from the same original parameter have the same dummy decl stored
-     along with them.
-
-     Dummy decls sit in call statement arguments followed by new parameter
-     decls (or their SSA names) in between (caller) clone materialization and
-     call redirection.  Redirection then recognizes the dummy variable and
-     together with the stored offsets can reconstruct what exactly the new
-     parameter decls represent and can leave in place only those that the
-     callee expects.  */
-  vec<ipa_param_performed_split, va_gc> *performed_splits;
 
   /* Return clone_info, if available.  */
   static clone_info *get (cgraph_node *node);
diff --git a/gcc/testsuite/g++.dg/ipa/ipa-sra-4.C b/gcc/testsuite/g++.dg/ipa/ipa-sra-4.C
new file mode 100644
index 00000000000..56d59f9fd9a
--- /dev/null
+++ b/gcc/testsuite/g++.dg/ipa/ipa-sra-4.C
@@ -0,0 +1,37 @@ 
+/* { dg-do compile { target c++11 } } */
+/* { dg-options "-O2 -fipa-sra"  } */
+
+void __throw_bad_alloc() __attribute__((__noreturn__));
+void __throw_bad_array_new_length();
+template <typename> class allocator {};
+template <typename> struct allocator_traits;
+int *allocate___trans_tmp_2;
+template <typename _Tp> struct allocator_traits<allocator<_Tp>> {
+  using allocator_type = allocator<_Tp>;
+  using pointer = _Tp *;
+  using size_type = long;
+  static pointer allocate(allocator_type &, size_type __n) {
+    long __trans_tmp_3 = __n;
+    if (__builtin_expect(__trans_tmp_3, false))
+      if (__trans_tmp_3)
+        __throw_bad_array_new_length();
+    operator new(sizeof(int));
+    return allocate___trans_tmp_2;
+  }
+};
+class throw_allocator_base {
+  allocator<int> _M_allocator;
+public:
+  int *allocate(long __n) {
+    if (__n)
+      __throw_bad_alloc();
+    int *a = allocator_traits<allocator<int>>::allocate(_M_allocator, __n);
+    return a;
+  }
+};
+template <typename Alloc> void check_allocate_max_size() {
+  Alloc a;
+  long __trans_tmp_1 = 0;
+  a.allocate(__trans_tmp_1 + 1);
+}
+int main() { check_allocate_max_size<throw_allocator_base>(); }
diff --git a/gcc/testsuite/gcc.dg/ipa/ipa-sra-23.c b/gcc/testsuite/gcc.dg/ipa/ipa-sra-23.c
new file mode 100644
index 00000000000..f438b509614
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/ipa/ipa-sra-23.c
@@ -0,0 +1,24 @@ 
+/* { dg-do compile } */
+/* { dg-options "-O2"  } */
+
+extern int g;
+
+static int __attribute__((noinline))
+bar (int i, int j)
+{
+  return 2*g + i;
+}
+
+static int __attribute__((noinline))
+foo (int i, int j)
+{
+  if (i > 5)
+    j = 22;
+  return bar (i, j) + 1;
+}
+
+int
+entry (int l, int k)
+{
+  return foo (l, k);
+}
diff --git a/gcc/testsuite/gcc.dg/ipa/ipa-sra-24.c b/gcc/testsuite/gcc.dg/ipa/ipa-sra-24.c
new file mode 100644
index 00000000000..7b5bf0825fc
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/ipa/ipa-sra-24.c
@@ -0,0 +1,20 @@ 
+/* { dg-do compile } */
+/* { dg-options "-O2 -Wmaybe-uninitialized -Werror"  } */
+
+int *ttmp_1;
+_Bool pt_ins_tipdo, pq_ins_apd, pq_ins_tt2;
+int gtrphdt;
+
+void pl_ins(int, _Bool, _Bool);
+inline void pt_ins(int *, _Bool apdo) {
+  int list = *ttmp_1;
+  pl_ins(list, apdo, pt_ins_tipdo);
+}
+void pq_ins(int *t) {
+  if (pq_ins_tt2)
+    pt_ins(t, pq_ins_apd);
+}
+int gtr_post_hd() {
+  pq_ins(&gtrphdt);
+  return 0;
+}
diff --git a/gcc/testsuite/gcc.dg/ipa/pr93385.c b/gcc/testsuite/gcc.dg/ipa/pr93385.c
new file mode 100644
index 00000000000..6d1d0d7cd27
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/ipa/pr93385.c
@@ -0,0 +1,27 @@ 
+/* { dg-do run } */
+/* { dg-options "-O2 -fno-dce -fno-ipa-cp -fno-tree-dce" } */
+
+char a, b;
+
+#ifdef __SIZEOF_INT128__
+#define T unsigned __int128
+#else
+#define T unsigned
+#endif
+
+static inline int
+c (T d)
+{
+  char e = 0;
+  d %= (unsigned) d;
+  e -= 0;
+  __builtin_strncpy (&a, &e, 1);
+  return e + b;
+}
+
+int
+main (void)
+{
+  c (~0);
+  return 0;
+}
diff --git a/gcc/tree-inline.c b/gcc/tree-inline.c
index 1dcb31c0267..165c4ad7c72 100644
--- a/gcc/tree-inline.c
+++ b/gcc/tree-inline.c
@@ -1528,6 +1528,11 @@  remap_gimple_stmt (gimple *stmt, copy_body_data *id)
 	  : !opt_for_fn (id->dst_fn, flag_var_tracking_assignments)))
     return NULL;
 
+  if (!is_gimple_debug (stmt)
+      && id->param_body_adjs
+      && id->param_body_adjs->m_dead_stmts.contains (stmt))
+    return NULL;
+
   /* Begin by recognizing trees that we'll completely rewrite for the
      inlining context.  Our output for these trees is completely
      different from our input (e.g. RETURN_EXPR is deleted and morphs
@@ -1792,10 +1797,15 @@  remap_gimple_stmt (gimple *stmt, copy_body_data *id)
 
       if (gimple_debug_bind_p (stmt))
 	{
+	  tree value;
+	  if (id->param_body_adjs
+	      && id->param_body_adjs->m_dead_stmts.contains (stmt))
+	    value = NULL_TREE;
+	  else
+	    value = gimple_debug_bind_get_value (stmt);
 	  gdebug *copy
 	    = gimple_build_debug_bind (gimple_debug_bind_get_var (stmt),
-				       gimple_debug_bind_get_value (stmt),
-				       stmt);
+				       value, stmt);
 	  if (id->reset_location)
 	    gimple_set_location (copy, input_location);
 	  id->debug_stmts.safe_push (copy);
@@ -1924,7 +1934,7 @@  remap_gimple_stmt (gimple *stmt, copy_body_data *id)
   if (id->param_body_adjs)
     {
       gimple_seq extra_stmts = NULL;
-      id->param_body_adjs->modify_gimple_stmt (&copy, &extra_stmts);
+      id->param_body_adjs->modify_gimple_stmt (&copy, &extra_stmts, stmt);
       if (!gimple_seq_empty_p (extra_stmts))
 	{
 	  memset (&wi, 0, sizeof (wi));
@@ -2674,7 +2684,9 @@  copy_phis_for_bb (basic_block bb, copy_body_data *id)
       phi = si.phi ();
       res = PHI_RESULT (phi);
       new_res = res;
-      if (!virtual_operand_p (res))
+      if (!virtual_operand_p (res)
+	  && (!id->param_body_adjs
+	      || !id->param_body_adjs->m_dead_stmts.contains (phi)))
 	{
 	  walk_tree (&new_res, copy_tree_body_r, id, NULL);
 	  if (EDGE_COUNT (new_bb->preds) == 0)
@@ -4740,7 +4752,6 @@  expand_call_inline (basic_block bb, gimple *stmt, copy_body_data *id,
   use_operand_p use;
   gimple *simtenter_stmt = NULL;
   vec<tree> *simtvars_save;
-  clone_info *info;
 
   /* The gimplifier uses input_location in too many places, such as
      internal_get_tmp_var ().  */
@@ -5065,40 +5076,6 @@  expand_call_inline (basic_block bb, gimple *stmt, copy_body_data *id,
   /* Add local vars in this inlined callee to caller.  */
   add_local_variables (id->src_cfun, cfun, id);
 
-  info = clone_info::get (id->src_node);
-  if (info && info->performed_splits)
-    {
-      clone_info *dst_info = clone_info::get_create (id->dst_node);
-      /* Any calls from the inlined function will be turned into calls from the
-	 function we inline into.  We must preserve notes about how to split
-	 parameters such calls should be redirected/updated.  */
-      unsigned len = vec_safe_length (info->performed_splits);
-      for (unsigned i = 0; i < len; i++)
-	{
-	  ipa_param_performed_split ps
-	    = (*info->performed_splits)[i];
-	  ps.dummy_decl = remap_decl (ps.dummy_decl, id);
-	  vec_safe_push (dst_info->performed_splits, ps);
-	}
-
-      if (flag_checking)
-	{
-	  len = vec_safe_length (dst_info->performed_splits);
-	  for (unsigned i = 0; i < len; i++)
-	    {
-	      ipa_param_performed_split *ps1
-		= &(*dst_info->performed_splits)[i];
-	      for (unsigned j = i + 1; j < len; j++)
-		{
-		  ipa_param_performed_split *ps2
-		    = &(*dst_info->performed_splits)[j];
-		  gcc_assert (ps1->dummy_decl != ps2->dummy_decl
-			      || ps1->unit_offset != ps2->unit_offset);
-		}
-	    }
-	}
-    }
-
   if (dump_enabled_p ())
     {
       char buf[128];
@@ -6117,23 +6094,10 @@  tree_versionable_function_p (tree fndecl)
 static void
 update_clone_info (copy_body_data * id)
 {
-  clone_info *dst_info = clone_info::get (id->dst_node);
-  vec<ipa_param_performed_split, va_gc> *cur_performed_splits
-    = dst_info ? dst_info->performed_splits : NULL;
-  if (cur_performed_splits)
-    {
-      unsigned len = cur_performed_splits->length ();
-      for (unsigned i = 0; i < len; i++)
-	{
-	  ipa_param_performed_split *ps = &(*cur_performed_splits)[i];
-	  ps->dummy_decl = remap_decl (ps->dummy_decl, id);
-	}
-    }
-
-  struct cgraph_node *node;
-  if (!id->dst_node->clones)
+  struct cgraph_node *this_node = id->dst_node;
+  if (!this_node->clones)
     return;
-  for (node = id->dst_node->clones; node != id->dst_node;)
+  for (cgraph_node *node = this_node->clones; node != this_node;)
     {
       /* First update replace maps to match the new body.  */
       clone_info *info = clone_info::get (node);
@@ -6147,53 +6111,6 @@  update_clone_info (copy_body_data * id)
 	      walk_tree (&replace_info->new_tree, copy_tree_body_r, id, NULL);
 	    }
 	}
-      if (info && info->performed_splits)
-	{
-	  unsigned len = vec_safe_length (info->performed_splits);
-	  for (unsigned i = 0; i < len; i++)
-	    {
-	      ipa_param_performed_split *ps
-		= &(*info->performed_splits)[i];
-	      ps->dummy_decl = remap_decl (ps->dummy_decl, id);
-	    }
-	}
-      if (unsigned len = vec_safe_length (cur_performed_splits))
-	{
-	  /* We do not want to add current performed splits when we are saving
-	     a copy of function body for later during inlining, that would just
-	     duplicate all entries.  So let's have a look whether anything
-	     referring to the first dummy_decl is present.  */
-	  if (!info)
-	    info = clone_info::get_create (node);
-	  unsigned dst_len = vec_safe_length (info->performed_splits);
-	  ipa_param_performed_split *first = &(*cur_performed_splits)[0];
-	  for (unsigned i = 0; i < dst_len; i++)
-	    if ((*info->performed_splits)[i].dummy_decl
-		== first->dummy_decl)
-	      {
-		len = 0;
-		break;
-	      }
-
-	  for (unsigned i = 0; i < len; i++)
-	    vec_safe_push (info->performed_splits,
-			   (*cur_performed_splits)[i]);
-	  if (flag_checking)
-	    {
-	      for (unsigned i = 0; i < dst_len; i++)
-		{
-		  ipa_param_performed_split *ps1
-		    = &(*info->performed_splits)[i];
-		  for (unsigned j = i + 1; j < dst_len; j++)
-		    {
-		      ipa_param_performed_split *ps2
-			= &(*info->performed_splits)[j];
-		      gcc_assert (ps1->dummy_decl != ps2->dummy_decl
-				  || ps1->unit_offset != ps2->unit_offset);
-		    }
-		}
-	    }
-	}
 
       if (node->clones)
 	node = node->clones;