[v2] bring netbsd/arm support up to speed. eabi, etc.

Message ID 20181031141014.GA24365@SDF.ORG
State New
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  • [v2] bring netbsd/arm support up to speed. eabi, etc.
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Commit Message

Maya Rashish Oct. 31, 2018, 2:10 p.m.
Thanks for the feedback. I made some improvements.
Changes from the first patch:

config.gcc:
need_64bit_hwint=yes No longer needed
resolve conflict from strongarm being default for netbsd.
switch default cpu for armv7--netbsdelf-eabi: cortex-a8 -> generic-armv7-a,
(make -mfpu=auto pick VFPv3-D16)
remove redundant extra configuration for armv4, all it did was pick
strongarm as the default CPU, and now it is the default CPU for all
arm*-*-netbsdelf*.
(This means there is no natural place to rule out armv4-eabihf configurations,
so I didn't add it - do we still want it?)


config/arm/netbsd-eabi.h:
remove BE8_LINK_SPEC, not needed any more
remove SUBTARGET_ASM_FLOAT_SPEC, handled by generic ARM code better,
with -mfpu=auto

config/arm/netbsd-elf.h:
don't define FPUTYPE_DEFAULT, it's unused.
remove CTOR_LISTS_DEFINED_EXTERNALLY definition, it's unused.



Some things that I am still conflicted about:
- I get the libgcc_s.so mismatch on native builds. This wasn't a problem
  in a previous attempt against gcc-7, I haven't pinned down why yet.
- there's duplicate logic for picking default CPU in
gcc/config/arm/netbsd-elf.h
- CTOR_LISTS_DEFINED_EXTERNALLY does nothing now, but I'm not sure
we actually didn't need it.
- I didn't add HOST_LIBGCC2_CFLAGS, I'll have to do some
investigation why it was put in place.


changelog entries (I assume that they need to be split out like
this)

gcc:

config.gcc (arm*-*-netbsdelf*) Add support for EABI configuration
config.host (arm*-*-netbsd*): Build driver-arm.o
config/arm/netbsd-eabi.h: New file.
config/arm/netbsd-elf.h
config/netbsd-elf.h: Define SUBTARGET_EXTRA_SPECS.

libgcc:

config.host (arm*-*-netbsdelf*): Add support for EABI configuration
config/arm/t-netbsd: LIB1ASMFUNCS: Append to existing set.
		     HOST_LIBGCC2_CFLAGS: workaround possible bug
config/arm/t-netbsd-eabi: New file.
---
 gcc/config.gcc                  | 29 +++++++++-
 gcc/config.host                 |  2 +-
 gcc/config/arm/netbsd-eabi.h    | 97 +++++++++++++++++++++++++++++++++
 gcc/config/arm/netbsd-elf.h     |  1 +
 gcc/config/netbsd-elf.h         | 15 +++++
 libgcc/config.host              | 11 +++-
 libgcc/config/arm/t-netbsd      | 15 ++++-
 libgcc/config/arm/t-netbsd-eabi | 18 ++++++
 8 files changed, 181 insertions(+), 7 deletions(-)
 create mode 100644 gcc/config/arm/netbsd-eabi.h
 create mode 100644 libgcc/config/arm/t-netbsd-eabi

-- 
2.19.1

Comments

Richard Earnshaw (lists) Oct. 31, 2018, 3:23 p.m. | #1
On 31/10/2018 14:10, coypu@sdf.org wrote:
> +

> +# Currently there is a bug somewhere in GCC's alias analysis

> +# or scheduling code that is breaking _fpmul_parts in fp-bit.c.

> +# Disabling function inlining is a workaround for this problem.

> +HOST_LIBGCC2_CFLAGS += -fno-inline


This needs to be investigated properly (and fixed if it's still a problem).

R.
Maya Rashish Oct. 31, 2018, 10:04 p.m. | #2
On Wed, Oct 31, 2018 at 03:23:27PM +0000, Richard Earnshaw (lists) wrote:
> On 31/10/2018 14:10, coypu@sdf.org wrote:

> > +

> > +# Currently there is a bug somewhere in GCC's alias analysis

> > +# or scheduling code that is breaking _fpmul_parts in fp-bit.c.

> > +# Disabling function inlining is a workaround for this problem.

> > +HOST_LIBGCC2_CFLAGS += -fno-inline

> 

> This needs to be investigated properly (and fixed if it's still a problem).

> 

> R.


After some VCS digging, it turns out you committed this change:
https://github.com/gcc-mirror/gcc/commit/cffb2a26c44c682185b6bb405d48fcbe1fbc0b37

NetBSD copied it over from existing GCC files, and it still exists in
GCC trunk, in libgcc/config/arm/t-elf.
Richard Earnshaw (lists) Nov. 2, 2018, 11:04 a.m. | #3
On 31/10/2018 22:04, coypu@sdf.org wrote:
> On Wed, Oct 31, 2018 at 03:23:27PM +0000, Richard Earnshaw (lists) wrote:

>> On 31/10/2018 14:10, coypu@sdf.org wrote:

>>> +

>>> +# Currently there is a bug somewhere in GCC's alias analysis

>>> +# or scheduling code that is breaking _fpmul_parts in fp-bit.c.

>>> +# Disabling function inlining is a workaround for this problem.

>>> +HOST_LIBGCC2_CFLAGS += -fno-inline

>>

>> This needs to be investigated properly (and fixed if it's still a problem).

>>

>> R.

> 

> After some VCS digging, it turns out you committed this change:

> https://github.com/gcc-mirror/gcc/commit/cffb2a26c44c682185b6bb405d48fcbe1fbc0b37

> 

> NetBSD copied it over from existing GCC files, and it still exists in

> GCC trunk, in libgcc/config/arm/t-elf.

> 


Sorry about that.  You don't really expect me to remember every patch I
committed 18 years ago!

And pedantically, that was a branch merge patch.  The original commit
(back in the CVS days) was:


  revision 1.9.2.1
  date: 1999/10/25 17:47:02;  author: [redacted];  state: Exp;  lines:
+34 -10
  Initial check in of merged arm/thumb backend.

However, the age of this makes me suspect that it quite likely is not
relevant any more and that we should investigate whether it is safe to
remove.  We're running some tests here, but can you test the NetBSD port
without that as well for another data point?

R.
Maya Rashish Nov. 2, 2018, 5:37 p.m. | #4
On Fri, Nov 02, 2018 at 11:04:06AM +0000, Richard Earnshaw (lists) wrote:
> Sorry about that.  You don't really expect me to remember every patch I

> committed 18 years ago!

> 

> And pedantically, that was a branch merge patch.  The original commit

> (back in the CVS days) was:

> 

> 

>   revision 1.9.2.1

>   date: 1999/10/25 17:47:02;  author: [redacted];  state: Exp;  lines:

> +34 -10

>   Initial check in of merged arm/thumb backend.

> 

> However, the age of this makes me suspect that it quite likely is not

> relevant any more and that we should investigate whether it is safe to

> remove.  We're running some tests here, but can you test the NetBSD port

> without that as well for another data point?


I thought it's funny, sorry :-)
netbsd seems to only do this for OABI (and defaults to EABI).
I tried it anyway on netbsd's mutant GCC 6.4 and ran a full userland with
it. It works really well!
I'm surprised I can run code that file identifies as "ARMv1" on a machine
that can run Aarch64.

Patch

diff --git a/gcc/config.gcc b/gcc/config.gcc
index b108697cf..10e2477c6 100644
--- a/gcc/config.gcc
+++ b/gcc/config.gcc
@@ -1155,10 +1155,33 @@  arm*-*-freebsd*)                # ARM FreeBSD EABI
 	with_tls=${with_tls:-gnu}
 	;;
 arm*-*-netbsdelf*)
-	tm_file="dbxelf.h elfos.h ${nbsd_tm_file} arm/elf.h arm/aout.h ${tm_file} arm/netbsd-elf.h"
-	extra_options="${extra_options} netbsd.opt netbsd-elf.opt"
-	tmake_file="${tmake_file} arm/t-arm"
 	target_cpu_cname="strongarm"
+ 	tmake_file="${tmake_file} arm/t-arm"
+	tm_file="dbxelf.h elfos.h ${nbsd_tm_file} arm/elf.h"
+	extra_options="${extra_options} netbsd.opt netbsd-elf.opt"
+	case ${target} in
+	arm*eb-*) tm_defines="${tm_defines} TARGET_BIG_ENDIAN_DEFAULT=1" ;;
+	esac
+	case ${target} in
+	arm*-*-netbsdelf-*eabi*)
+	    tm_file="$tm_file arm/bpabi.h arm/netbsd-elf.h arm/netbsd-eabi.h"
+	    tmake_file="$tmake_file arm/t-bpabi arm/t-netbsdeabi"
+	    ;;
+	*)
+	    tm_file="$tm_file arm/netbsd-elf.h"
+	    tmake_file="$tmake_file arm/t-netbsd"
+	    ;;
+	esac
+	tm_file="${tm_file} arm/aout.h arm/arm.h"
+	case ${target} in
+	arm*-*-netbsdelf-*eabihf*)
+	    tm_defines="${tm_defines} TARGET_DEFAULT_FLOAT_ABI=ARM_FLOAT_ABI_HARD"
+	    ;;
+	esac
+	case ${target} in
+	armv6*) target_cpu_cname="arm1176jzf-s";;
+	armv7*) target_cpu_cname="generic-armv7-a";;
+	esac
 	;;
 arm*-*-linux-*)			# ARM GNU/Linux with ELF
 	tm_file="dbxelf.h elfos.h gnu-user.h linux.h linux-android.h glibc-stdint.h arm/elf.h arm/linux-gas.h arm/linux-elf.h"
diff --git a/gcc/config.host b/gcc/config.host
index c65569da2..59208d250 100644
--- a/gcc/config.host
+++ b/gcc/config.host
@@ -107,7 +107,7 @@  case ${host} in
 	;;
     esac
     ;;
-  arm*-*-freebsd* | arm*-*-linux* | arm*-*-fuchsia*)
+  arm*-*-freebsd* | arm*-*-netbsd* | arm*-*-linux* | arm*-*-fuchsia*)
     case ${target} in
       arm*-*-*)
 	host_extra_gcc_objs="driver-arm.o"
diff --git a/gcc/config/arm/netbsd-eabi.h b/gcc/config/arm/netbsd-eabi.h
new file mode 100644
index 000000000..13bc27417
--- /dev/null
+++ b/gcc/config/arm/netbsd-eabi.h
@@ -0,0 +1,97 @@ 
+/* Definitions of target machine for GNU compiler, NetBSD/arm ELF version.
+   Copyright (C) 2002, 2003, 2004, 2005, 2007 Free Software Foundation, Inc.
+   Contributed by Wasabi Systems, Inc.
+
+   This file is part of GCC.
+
+   GCC is free software; you can redistribute it and/or modify it
+   under the terms of the GNU General Public License as published
+   by the Free Software Foundation; either version 3, or (at your
+   option) any later version.
+
+   GCC is distributed in the hope that it will be useful, but WITHOUT
+   ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+   or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public
+   License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with GCC; see the file COPYING3.  If not see
+   <http://www.gnu.org/licenses/>.  */
+
+/* Run-time Target Specification.  */
+#undef MULTILIB_DEFAULTS
+#define MULTILIB_DEFAULTS { "mabi=aapcs-linux" }
+
+#define TARGET_LINKER_EABI_SUFFIX \
+    (TARGET_DEFAULT_FLOAT_ABI == ARM_FLOAT_ABI_SOFT \
+     ? "%{!mabi=apcs-gnu:%{!mabi=atpcs:%{mfloat-abi=hard:_eabihf;:_eabi}}}" \
+     : "%{!mabi=apcs-gnu:%{!mabi=atpcs:%{mfloat-abi=soft:_eabi;:_eabihf}}}")
+#define TARGET_LINKER_BIG_EMULATION "armelfb_nbsd%(linker_eabi_suffix)"
+#define TARGET_LINKER_LITTLE_EMULATION "armelf_nbsd%(linker_eabi_suffix)"
+
+/* TARGET_BIG_ENDIAN_DEFAULT is set in
+   config.gcc for big endian configurations.  */
+#undef  TARGET_LINKER_EMULATION
+#if TARGET_BIG_ENDIAN_DEFAULT
+#define TARGET_LINKER_EMULATION TARGET_LINKER_BIG_EMULATION
+#else
+#define TARGET_LINKER_EMULATION TARGET_LINKER_LITTLE_EMULATION
+#endif
+
+#undef ARM_DEFAULT_ABI
+#define ARM_DEFAULT_ABI ARM_ABI_AAPCS_LINUX
+
+#undef ARM_UNWIND_INFO
+#define ARM_UNWIND_INFO 0
+#undef DWARF2_UNWIND_INFO
+#define DWARF2_UNWIND_INFO 1
+
+#undef TARGET_OS_CPP_BUILTINS
+#define TARGET_OS_CPP_BUILTINS()		\
+  do						\
+    {						\
+      if (TARGET_AAPCS_BASED)			\
+	TARGET_BPABI_CPP_BUILTINS();		\
+      NETBSD_OS_CPP_BUILTINS_ELF();		\
+      if (DWARF2_UNWIND_INFO)			\
+	builtin_define ("__ARM_DWARF_EH__");	\
+    }						\
+  while (0)
+
+#undef SUBTARGET_CPP_SPEC
+#define SUBTARGET_CPP_SPEC NETBSD_CPP_SPEC
+
+/*
+ * Override AAPCS types to remain compatible the existing NetBSD types.
+ */
+#undef WCHAR_TYPE
+#define WCHAR_TYPE "int"
+
+#undef SIZE_TYPE
+#define SIZE_TYPE "long unsigned int"
+ 
+#undef PTRDIFF_TYPE
+#define PTRDIFF_TYPE "long int"
+
+#undef SUBTARGET_EXTRA_ASM_SPEC
+#define SUBTARGET_EXTRA_ASM_SPEC	\
+  "-matpcs %{mabi=apcs-gnu|mabi=atpcs:-meabi=gnu} %{fpic|fpie:-k} %{fPIC|fPIE:-k}"
+
+#undef SUBTARGET_EXTRA_SPECS
+#define SUBTARGET_EXTRA_SPECS				\
+  { "subtarget_extra_asm_spec",	SUBTARGET_EXTRA_ASM_SPEC }, \
+  { "linker_eabi_suffix",	TARGET_LINKER_EABI_SUFFIX }, \
+  { "linker_emulation",		TARGET_LINKER_EMULATION }, \
+  { "linker_big_emulation",	TARGET_LINKER_BIG_EMULATION }, \
+  { "linker_little_emulation",	TARGET_LINKER_LITTLE_EMULATION }, \
+  { "target_fix_v4bx_spec",	TARGET_FIX_V4BX_SPEC }, \
+  NETBSD_SUBTARGET_EXTRA_SPECS
+
+#define NETBSD_ENTRY_POINT "__start"
+
+#undef LINK_SPEC
+#define LINK_SPEC \
+  "-X %{mbig-endian:-EB -m %(linker_big_emulation)} \
+   %{mlittle-endian:-EL -m %(linker_liitle_emulation)} \
+   %{!mbig-endian:%{!mlittle-endian:-m %(linker_emulation)}} \
+   %(target_fix_v4bx_spec) %(netbsd_link_spec)"
diff --git a/gcc/config/arm/netbsd-elf.h b/gcc/config/arm/netbsd-elf.h
index 11247716c..ab7505337 100644
--- a/gcc/config/arm/netbsd-elf.h
+++ b/gcc/config/arm/netbsd-elf.h
@@ -43,6 +43,7 @@ 
 #undef ARM_DEFAULT_ABI
 #define ARM_DEFAULT_ABI ARM_ABI_ATPCS
 
+#undef TARGET_OS_CPP_BUILTINS
 #define TARGET_OS_CPP_BUILTINS()	\
   do					\
     {					\
diff --git a/gcc/config/netbsd-elf.h b/gcc/config/netbsd-elf.h
index 4dc2aa757..33677b126 100644
--- a/gcc/config/netbsd-elf.h
+++ b/gcc/config/netbsd-elf.h
@@ -1,4 +1,5 @@ 
 /* Common configuration file for NetBSD ELF targets.
+
    Copyright (C) 2002-2018 Free Software Foundation, Inc.
    Contributed by Wasabi Systems, Inc.
 
@@ -67,6 +68,9 @@  along with GCC; see the file COPYING3.  If not see
 
    Target-specific code must provide the %(netbsd_entry_point) spec.  */
 
+#define NETBSD_LINK_LD_ELF_SO_SPEC \
+  "%{!dynamic-linker:-dynamic-linker /usr/libexec/ld.elf_so}"
+
 #define NETBSD_LINK_SPEC_ELF \
   "%{assert*} %{R*} %{rpath*} \
    %{shared:-shared} \
@@ -81,6 +85,17 @@  along with GCC; see the file COPYING3.  If not see
        -dynamic-linker /usr/libexec/ld.elf_so} \
      %{static:-static}}"
 
+/* Provide the standard list of subtarget extra specs for NetBSD targets.  */
+#define NETBSD_SUBTARGET_EXTRA_SPECS \
+  { "netbsd_link_ld_elf_so",    NETBSD_LINK_LD_ELF_SO_SPEC }, \
+  { "netbsd_cpp_spec",          NETBSD_CPP_SPEC }, \
+  { "netbsd_link_spec",         NETBSD_LINK_SPEC_ELF }, \
+  { "netbsd_entry_point",       NETBSD_ENTRY_POINT }, \
+  { "netbsd_endfile_spec",      NETBSD_ENDFILE_SPEC },
+
+#undef SUBTARGET_EXTRA_SPECS
+#define SUBTARGET_EXTRA_SPECS   NETBSD_SUBTARGET_EXTRA_SPECS
+
 /* Use --as-needed -lgcc_s for eh support.  */
 #ifdef HAVE_LD_AS_NEEDED
 #define USE_LD_AS_NEEDED 1
diff --git a/libgcc/config.host b/libgcc/config.host
index 029f6569c..bcc754269 100644
--- a/libgcc/config.host
+++ b/libgcc/config.host
@@ -422,7 +422,16 @@  arm*-*-fuchsia*)
 	unwind_header=config/arm/unwind-arm.h
 	;;
 arm*-*-netbsdelf*)
-	tmake_file="$tmake_file arm/t-arm arm/t-netbsd t-slibgcc-gld-nover"
+	tmake_file="$tmake_file arm/t-arm"
+	case ${host} in
+	  arm*-*-netbsdelf-*eabi*)
+	    tmake_file="${tmake_file} arm/t-netbsd-eabi"
+	    unwind_header=config/arm/unwind-arm.h
+	    ;;
+	  *)
+	    tmake_file="${tmake_file} arm/t-netbsd t-slibgcc-gld-nover"
+	    ;;
+	esac
 	;;
 arm*-*-linux*)			# ARM GNU/Linux with ELF
 	tmake_file="${tmake_file} arm/t-arm t-fixedpoint-gnu-prefix t-crtfm"
diff --git a/libgcc/config/arm/t-netbsd b/libgcc/config/arm/t-netbsd
index 95358f931..36ca3e6ea 100644
--- a/libgcc/config/arm/t-netbsd
+++ b/libgcc/config/arm/t-netbsd
@@ -1,7 +1,18 @@ 
+# This list is from t-elf, but with some things removed.
+LIB1ASMFUNCS += _udivsi3 _divsi3 _umodsi3 _modsi3 _dvmd_tls _bb_init_func \
+	_call_via_rX _interwork_call_via_rX \
+	_arm_fixunsdfsi _arm_fixunssfsi \
+	_arm_floatdidf _arm_floatdisf _arm_floatundidf _arm_floatundisf \
+	_lshrdi3 _ashrdi3 _ashldi3 \
+	_clzsi2 _clzdi2 _ctzsi2
+
 # Just for these, we omit the frame pointer since it makes such a big
 # difference.  It is then pointless adding debugging.
 HOST_LIBGCC2_CFLAGS += -fomit-frame-pointer
 
-LIBGCC2_DEBUG_CFLAGS = -g0
-
 LIB2ADD += $(srcdir)/floatunsidf.c $(srcdir)/floatunsisf.c
+
+# Currently there is a bug somewhere in GCC's alias analysis
+# or scheduling code that is breaking _fpmul_parts in fp-bit.c.
+# Disabling function inlining is a workaround for this problem.
+HOST_LIBGCC2_CFLAGS += -fno-inline
diff --git a/libgcc/config/arm/t-netbsd-eabi b/libgcc/config/arm/t-netbsd-eabi
new file mode 100644
index 000000000..ae08ea43e
--- /dev/null
+++ b/libgcc/config/arm/t-netbsd-eabi
@@ -0,0 +1,18 @@ 
+# This list is from t-elf, but with lots removed.
+LIB1ASMFUNCS += _dvmd_tls _bb_init_func _call_via_rX _interwork_call_via_rX \
+        _clzsi2 _clzdi2 _ctzsi2
+
+# Derived from t-bpabi
+# Add the BPABI C functions.
+LIB2ADD +=    $(srcdir)/config/arm/unaligned-funcs.c
+
+# Not using libgcc for EH.
+LIB2ADDEH =
+
+# Add the BPABI names.
+SHLIB_MAPFILES += $(srcdir)/config/arm/libgcc-bpabi.ver
+
+# On ARM, specifying -fnon-call-exceptions will needlessly pull in
+# the unwinder in simple programs which use 64-bit division.  Omitting
+# the option is safe.
+LIB2_DIVMOD_EXCEPTION_FLAGS := -fexceptions