sra: Avoid verification failure (PR 93516)

Message ID ri6h7ztwgcc.fsf@suse.cz
State New
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  • sra: Avoid verification failure (PR 93516)
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Commit Message

Martin Jambor Feb. 14, 2020, 11:36 a.m.
Hi,

get_ref_base_and_extent can return different sizes for COMPONENT_REFs
and DECLs of the same type, with the latter including (more?)  padding.
When in the IL there is an assignment between such a COMPONENT_REF and a
DECL, SRA will try to propagate the access from the former as a child of
the latter, creating an artificial reference that does not match the
access's declared size, which triggers a verifier assert.

Fixed by teaching the propagation functions about this special situation
so that they don't do it.  The condition is the same that
build_user_friendly_ref_for_offset uses so the artificial reference
causing the verifier is guaranteed not to be created.

Bootstrapped and tested on x86_64-linux.  OK for trunk?

Thanks,

Martin


2020-02-10  Martin Jambor  <mjambor@suse.cz>
	PR tree-optimization/93516
	* tree-sra.c (propagate_subaccesses_from_rhs): Do not create
	access of the same type as the parent.
	(propagate_subaccesses_from_lhs): Likewise.

	gcc/testsuite/
	* g++.dg/tree-ssa/pr93516.C: New test.
---
 gcc/ChangeLog                           |  7 ++++++
 gcc/testsuite/ChangeLog                 |  5 ++++
 gcc/testsuite/g++.dg/tree-ssa/pr93516.C | 24 +++++++++++++++++++
 gcc/tree-sra.c                          | 31 +++++++++++++++++++------
 4 files changed, 60 insertions(+), 7 deletions(-)
 create mode 100644 gcc/testsuite/g++.dg/tree-ssa/pr93516.C

-- 
2.25.0

Comments

Richard Biener Feb. 14, 2020, 11:47 a.m. | #1
On Fri, 14 Feb 2020, Martin Jambor wrote:

> Hi,

> 

> get_ref_base_and_extent can return different sizes for COMPONENT_REFs

> and DECLs of the same type, with the latter including (more?)  padding.

> When in the IL there is an assignment between such a COMPONENT_REF and a

> DECL, SRA will try to propagate the access from the former as a child of

> the latter, creating an artificial reference that does not match the

> access's declared size, which triggers a verifier assert.


"both" use DECL_SIZE, but those can differ dependent on alignment
for example.

> Fixed by teaching the propagation functions about this special situation

> so that they don't do it.  The condition is the same that

> build_user_friendly_ref_for_offset uses so the artificial reference

> causing the verifier is guaranteed not to be created.

> 

> Bootstrapped and tested on x86_64-linux.  OK for trunk?


OK.

Thanks,
Richard.

> Thanks,

> 

> Martin

> 

> 

> 2020-02-10  Martin Jambor  <mjambor@suse.cz>

> 	PR tree-optimization/93516

> 	* tree-sra.c (propagate_subaccesses_from_rhs): Do not create

> 	access of the same type as the parent.

> 	(propagate_subaccesses_from_lhs): Likewise.

> 

> 	gcc/testsuite/

> 	* g++.dg/tree-ssa/pr93516.C: New test.

> ---

>  gcc/ChangeLog                           |  7 ++++++

>  gcc/testsuite/ChangeLog                 |  5 ++++

>  gcc/testsuite/g++.dg/tree-ssa/pr93516.C | 24 +++++++++++++++++++

>  gcc/tree-sra.c                          | 31 +++++++++++++++++++------

>  4 files changed, 60 insertions(+), 7 deletions(-)

>  create mode 100644 gcc/testsuite/g++.dg/tree-ssa/pr93516.C

> 

> diff --git a/gcc/ChangeLog b/gcc/ChangeLog

> index fa3cbb895e9..daba335cf79 100644

> --- a/gcc/ChangeLog

> +++ b/gcc/ChangeLog

> @@ -1,3 +1,10 @@

> +2020-02-10  Martin Jambor  <mjambor@suse.cz>

> +

> +	PR tree-optimization/93516

> +	* tree-sra.c (propagate_subaccesses_from_rhs): Do not create

> +	access of the same type as the parent.

> +	(propagate_subaccesses_from_lhs): Likewise.

> +

>  2020-02-10  Feng Xue  <fxue@os.amperecomputing.com>

>  

>  	PR ipa/93203

> diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog

> index 0ede9604611..eada2ebed63 100644

> --- a/gcc/testsuite/ChangeLog

> +++ b/gcc/testsuite/ChangeLog

> @@ -1,3 +1,8 @@

> +2020-02-10  Martin Jambor  <mjambor@suse.cz>

> +

> +	PR tree-optimization/93516

> +	* g++.dg/tree-ssa/pr93516.C: New test.

> +

>  2020-02-10  Feng Xue  <fxue@os.amperecomputing.com>

>  

>  	PR ipa/93203

> diff --git a/gcc/testsuite/g++.dg/tree-ssa/pr93516.C b/gcc/testsuite/g++.dg/tree-ssa/pr93516.C

> new file mode 100644

> index 00000000000..2bba37c1386

> --- /dev/null

> +++ b/gcc/testsuite/g++.dg/tree-ssa/pr93516.C

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

> +// { dg-do compile }

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

> +

> +struct b;

> +struct c {

> +  b *operator->();

> +};

> +class e {

> +  void *f;

> +  int d;

> +

> +public:

> +  template <typename a> a g() { return *static_cast<a *>(this); }

> +};

> +struct h : e {};

> +struct b {

> +  void i(e);

> +  e j();

> +};

> +void m() {

> +  c k;

> +  h l = k->j().g<h>();

> +  k->i(l);

> +}

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

> index ea8594db193..a3bcd5f3e03 100644

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

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

> @@ -2785,9 +2785,17 @@ propagate_subaccesses_from_rhs (struct access *lacc, struct access *racc)

>  	}

>  

>        rchild->grp_hint = 1;

> -      new_acc = create_artificial_child_access (lacc, rchild, norm_offset,

> -						false, (lacc->grp_write

> -							|| rchild->grp_write));

> +      /* Because get_ref_base_and_extent always includes padding in size for

> +	 accesses to DECLs but not necessarily for COMPONENT_REFs of the same

> +	 type, we might be actually attempting to here to create a child of the

> +	 same type as the parent.  */

> +      if (!types_compatible_p (lacc->type, rchild->type))

> +	new_acc = create_artificial_child_access (lacc, rchild, norm_offset,

> +						  false,

> +						  (lacc->grp_write

> +						   || rchild->grp_write));

> +      else

> +	new_acc = lacc;

>        gcc_checking_assert (new_acc);

>        if (racc->first_child)

>  	propagate_subaccesses_from_rhs (new_acc, rchild);

> @@ -2834,10 +2842,19 @@ propagate_subaccesses_from_lhs (struct access *lacc, struct access *racc)

>  	  continue;

>  	}

>  

> -      struct access *new_acc

> -	=  create_artificial_child_access (racc, lchild, norm_offset,

> -					   true, false);

> -      propagate_subaccesses_from_lhs (lchild, new_acc);

> +      /* Because get_ref_base_and_extent always includes padding in size for

> +	 accesses to DECLs but not necessarily for COMPONENT_REFs of the same

> +	 type, we might be actually attempting to here to create a child of the

> +	 same type as the parent.  */

> +      if (!types_compatible_p (racc->type, lchild->type))

> +	{

> +	  struct access *new_acc

> +	    = create_artificial_child_access (racc, lchild, norm_offset,

> +					      true, false);

> +	  propagate_subaccesses_from_lhs (lchild, new_acc);

> +	}

> +      else

> +	propagate_subaccesses_from_lhs (lchild, racc);

>        ret = true;

>      }

>    return ret;

> 


-- 
Richard Biener <rguenther@suse.de>
SUSE Software Solutions Germany GmbH, Maxfeldstrasse 5, 90409 Nuernberg,
Germany; GF: Felix Imendörffer; HRB 36809 (AG Nuernberg)

Patch

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index fa3cbb895e9..daba335cf79 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,10 @@ 
+2020-02-10  Martin Jambor  <mjambor@suse.cz>
+
+	PR tree-optimization/93516
+	* tree-sra.c (propagate_subaccesses_from_rhs): Do not create
+	access of the same type as the parent.
+	(propagate_subaccesses_from_lhs): Likewise.
+
 2020-02-10  Feng Xue  <fxue@os.amperecomputing.com>
 
 	PR ipa/93203
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 0ede9604611..eada2ebed63 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@ 
+2020-02-10  Martin Jambor  <mjambor@suse.cz>
+
+	PR tree-optimization/93516
+	* g++.dg/tree-ssa/pr93516.C: New test.
+
 2020-02-10  Feng Xue  <fxue@os.amperecomputing.com>
 
 	PR ipa/93203
diff --git a/gcc/testsuite/g++.dg/tree-ssa/pr93516.C b/gcc/testsuite/g++.dg/tree-ssa/pr93516.C
new file mode 100644
index 00000000000..2bba37c1386
--- /dev/null
+++ b/gcc/testsuite/g++.dg/tree-ssa/pr93516.C
@@ -0,0 +1,24 @@ 
+// { dg-do compile }
+// { dg-options "-O2" } */
+
+struct b;
+struct c {
+  b *operator->();
+};
+class e {
+  void *f;
+  int d;
+
+public:
+  template <typename a> a g() { return *static_cast<a *>(this); }
+};
+struct h : e {};
+struct b {
+  void i(e);
+  e j();
+};
+void m() {
+  c k;
+  h l = k->j().g<h>();
+  k->i(l);
+}
diff --git a/gcc/tree-sra.c b/gcc/tree-sra.c
index ea8594db193..a3bcd5f3e03 100644
--- a/gcc/tree-sra.c
+++ b/gcc/tree-sra.c
@@ -2785,9 +2785,17 @@  propagate_subaccesses_from_rhs (struct access *lacc, struct access *racc)
 	}
 
       rchild->grp_hint = 1;
-      new_acc = create_artificial_child_access (lacc, rchild, norm_offset,
-						false, (lacc->grp_write
-							|| rchild->grp_write));
+      /* Because get_ref_base_and_extent always includes padding in size for
+	 accesses to DECLs but not necessarily for COMPONENT_REFs of the same
+	 type, we might be actually attempting to here to create a child of the
+	 same type as the parent.  */
+      if (!types_compatible_p (lacc->type, rchild->type))
+	new_acc = create_artificial_child_access (lacc, rchild, norm_offset,
+						  false,
+						  (lacc->grp_write
+						   || rchild->grp_write));
+      else
+	new_acc = lacc;
       gcc_checking_assert (new_acc);
       if (racc->first_child)
 	propagate_subaccesses_from_rhs (new_acc, rchild);
@@ -2834,10 +2842,19 @@  propagate_subaccesses_from_lhs (struct access *lacc, struct access *racc)
 	  continue;
 	}
 
-      struct access *new_acc
-	=  create_artificial_child_access (racc, lchild, norm_offset,
-					   true, false);
-      propagate_subaccesses_from_lhs (lchild, new_acc);
+      /* Because get_ref_base_and_extent always includes padding in size for
+	 accesses to DECLs but not necessarily for COMPONENT_REFs of the same
+	 type, we might be actually attempting to here to create a child of the
+	 same type as the parent.  */
+      if (!types_compatible_p (racc->type, lchild->type))
+	{
+	  struct access *new_acc
+	    = create_artificial_child_access (racc, lchild, norm_offset,
+					      true, false);
+	  propagate_subaccesses_from_lhs (lchild, new_acc);
+	}
+      else
+	propagate_subaccesses_from_lhs (lchild, racc);
       ret = true;
     }
   return ret;