PATCH [1/n]: Add initial -x32 support

["H.J. Lu" <hongjiu.lu@intel.com>]

Hi,

I'd like to start submitting a series of patches to enable x32:

https://sites.google.com/site/x32abi/

The GCC x32 branch is very stable. There are no unexpected failures in
C, C++, Fortran and Objective C testsuites.  SPEC CPU 2K/2006 compile
and run correctly at -O2 and -O3. 

More than 90% of changes are in x86 backend.  This is the first patch to
support x32.  By default, x32 is disabled and x32 run-time support
isn't required.  OK for trunk?

Thanks.


H.J.
---
2011-06-05  H.J. Lu  <hongjiu.lu@intel.com>

	* config.gcc: Support --enable-x32/--enable-ia32 for x86 Linux
	targets.

	* configure.ac: Support --enable-x32/--enable-ia32.
	* configure: Regenerated.

	* config/i386/gnu-user64.h (ASM_SPEC): Support x32.
	(LINK_SPEC): Likewise.
	(TARGET_THREAD_SSP_OFFSET): Likewise.
	(TARGET_THREAD_SPLIT_STACK_OFFSET): Likewise.

	* config/i386/i386.h (TARGET_X32): New.
	(TARGET_LP64): New.
	(LONG_TYPE_SIZE): Likewise.
	(POINTER_SIZE): Likewise.
	(POINTERS_EXTEND_UNSIGNED): Likewise.

	* config/i386/i386.opt (mx32): New.

	* config/i386/linux64.h (GLIBC_DYNAMIC_LINKERX32): New.

	* config/i386/t-linux64-x32: New.
	* config/i386/t-linuxx32: Likewise.

	* config/linux.h (UCLIBC_DYNAMIC_LINKERX32): New.
	(BIONIC_DYNAMIC_LINKERX32): Likewise.
	(GNU_USER_DYNAMIC_LINKERX32): Likewise.

	* doc/invoke.texi: Document -mx32.

diff --git a/gcc/config.gcc b/gcc/config.gcc
index 624129b..24b4a57 100644
--- a/gcc/config.gcc
+++ b/gcc/config.gcc
@@ -1232,7 +1232,17 @@ i[34567]86-*-linux* | i[34567]86-*-kfreebsd*-gnu | i[34567]86-*-knetbsd*-gnu | i
 		if test x$enable_targets = xall; then
 			tm_file="${tm_file} i386/x86-64.h i386/gnu-user64.h i386/linux64.h"
 			tm_defines="${tm_defines} TARGET_BI_ARCH=1"
-			tmake_file="${tmake_file} i386/t-linux64"
+			case x${enable_x32}${enable_ia32} in
+			xyesyes)
+				tmake_file="${tmake_file} i386/t-linuxx32"
+				;;
+			xyesno)
+				tmake_file="${tmake_file} i386/t-linux64-x32"
+				;;
+			*)
+				tmake_file="${tmake_file} i386/t-linux64"
+				;;
+			esac
 			need_64bit_hwint=yes
 			need_64bit_isa=yes
 			case X"${with_cpu}" in
@@ -1270,7 +1280,18 @@ x86_64-*-linux* | x86_64-*-kfreebsd*-gnu | x86_64-*-knetbsd*-gnu)
 	x86_64-*-kfreebsd*-gnu) tm_file="${tm_file} kfreebsd-gnu.h i386/kfreebsd-gnu.h" ;;
 	x86_64-*-knetbsd*-gnu) tm_file="${tm_file} knetbsd-gnu.h" ;;
 	esac
-	tmake_file="${tmake_file} i386/t-linux64 i386/t-crtstuff i386/t-crtpc i386/t-crtfm t-dfprules"
+	case x${enable_x32}${enable_ia32} in
+	xyesyes)
+		tmake_file="${tmake_file} i386/t-linuxx32"
+		;;
+	xyesno)
+		tmake_file="${tmake_file} i386/t-linux64-x32"
+		;;
+	*)
+		tmake_file="${tmake_file} i386/t-linux64"
+		;;
+	esac
+	tmake_file="${tmake_file} i386/t-crtstuff i386/t-crtpc i386/t-crtfm t-dfprules"
 	;;
 i[34567]86-pc-msdosdjgpp*)
 	xm_file=i386/xm-djgpp.h
diff --git a/gcc/config/i386/gnu-user64.h b/gcc/config/i386/gnu-user64.h
index 3ece0fa..b99fb13 100644
--- a/gcc/config/i386/gnu-user64.h
+++ b/gcc/config/i386/gnu-user64.h
@@ -65,17 +65,20 @@ see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
 #endif
 
 #undef ASM_SPEC
-#define ASM_SPEC "%{" SPEC_32 ":--32} %{" SPEC_64 ":--64} \
+#define ASM_SPEC "%{" SPEC_32 ":%{!mx32:--32}} %{" \
+ SPEC_64 ":%{!mx32:--64}} %{mx32:--x32} \
  %{!mno-sse2avx:%{mavx:-msse2avx}} %{msse2avx:%{!mavx:-msse2avx}}"
 
 #undef	LINK_SPEC
-#define LINK_SPEC "%{" SPEC_64 ":-m elf_x86_64} %{" SPEC_32 ":-m elf_i386} \
+#define LINK_SPEC "%{" SPEC_64 ":%{!mx32:-m elf_x86_64}} %{" \
+  SPEC_32 ":%{!mx32:-m elf_i386}} %{mx32:-m elf32_x86_64} \
   %{shared:-shared} \
   %{!shared: \
     %{!static: \
       %{rdynamic:-export-dynamic} \
-      %{" SPEC_32 ":-dynamic-linker " GNU_USER_DYNAMIC_LINKER32 "} \
-      %{" SPEC_64 ":-dynamic-linker " GNU_USER_DYNAMIC_LINKER64 "}} \
+      %{" SPEC_32 ":%{!mx32:-dynamic-linker " GNU_USER_DYNAMIC_LINKER32 "}} \
+      %{" SPEC_64 ":%{!mx32:-dynamic-linker " GNU_USER_DYNAMIC_LINKER64 "}} \
+      %{mx32:-dynamic-linker " GNU_USER_DYNAMIC_LINKERX32 "}} \
     %{static:-static}}"
 
 /* Similar to standard GNU userspace, but adding -ffast-math support.  */
@@ -109,10 +112,13 @@ see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
 
 #ifdef TARGET_LIBC_PROVIDES_SSP
 /* i386 glibc provides __stack_chk_guard in %gs:0x14,
+   x32 glibc provides it in %fs:0x18. 
    x86_64 glibc provides it in %fs:0x28.  */
-#define TARGET_THREAD_SSP_OFFSET	(TARGET_64BIT ? 0x28 : 0x14)
+#define TARGET_THREAD_SSP_OFFSET \
+  (TARGET_64BIT ? (TARGET_X32 ? 0x18 : 0x28) : 0x14)
 
 /* We steal the last transactional memory word.  */
 #define TARGET_CAN_SPLIT_STACK
-#define TARGET_THREAD_SPLIT_STACK_OFFSET (TARGET_64BIT ? 0x70 : 0x30)
+#define TARGET_THREAD_SPLIT_STACK_OFFSET \
+  (TARGET_64BIT ? (TARGET_X32 ? 0x40 : 0x70) : 0x30)
 #endif
diff --git a/gcc/config/i386/i386.h b/gcc/config/i386/i386.h
index 8badcbb..f9270de 100644
--- a/gcc/config/i386/i386.h
+++ b/gcc/config/i386/i386.h
@@ -42,6 +42,7 @@ see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
 /* Redefines for option macros.  */
 
 #define TARGET_64BIT	OPTION_ISA_64BIT
+#define TARGET_X32	OPTION_ISA_X32
 #define TARGET_MMX	OPTION_ISA_MMX
 #define TARGET_3DNOW	OPTION_ISA_3DNOW
 #define TARGET_3DNOW_A	OPTION_ISA_3DNOW_A
@@ -72,6 +73,7 @@ see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
 #define TARGET_RDRND	OPTION_ISA_RDRND
 #define TARGET_F16C	OPTION_ISA_F16C
 
+#define TARGET_LP64	(TARGET_64BIT && !TARGET_X32)
 
 /* SSE4.1 defines round instructions */
 #define	OPTION_MASK_ISA_ROUND	OPTION_MASK_ISA_SSE4_1
@@ -638,6 +640,8 @@ enum target_cpu_default
 
 #define SHORT_TYPE_SIZE 16
 #define INT_TYPE_SIZE 32
+#define LONG_TYPE_SIZE (TARGET_X32 ? 32 : BITS_PER_WORD)
+#define POINTER_SIZE (TARGET_X32 ? 32 : BITS_PER_WORD)
 #define LONG_LONG_TYPE_SIZE 64
 #define FLOAT_TYPE_SIZE 32
 #define DOUBLE_TYPE_SIZE 64
@@ -1743,6 +1747,13 @@ do {							\
    between pointers and any other objects of this machine mode.  */
 #define Pmode (TARGET_64BIT ? DImode : SImode)
 
+/* A C expression whose value is zero if pointers that need to be extended
+   from being `POINTER_SIZE' bits wide to `Pmode' are sign-extended and
+   greater then zero if they are zero-extended and less then zero if the
+   ptr_extend instruction should be used.  */
+
+#define POINTERS_EXTEND_UNSIGNED 1
+
 /* A function address in a call instruction
    is a byte address (for indexing purposes)
    so give the MEM rtx a byte's mode.  */
diff --git a/gcc/config/i386/i386.opt b/gcc/config/i386/i386.opt
index 21e0def..2c8fe8f 100644
--- a/gcc/config/i386/i386.opt
+++ b/gcc/config/i386/i386.opt
@@ -398,9 +398,13 @@ Target RejectNegative Negative(m64) Report InverseMask(ISA_64BIT) Var(ix86_isa_f
 Generate 32bit i386 code
 
 m64
-Target RejectNegative Negative(m32) Report Mask(ISA_64BIT) Var(ix86_isa_flags) Save
+Target RejectNegative Negative(mx32) Report Mask(ISA_64BIT) Var(ix86_isa_flags) Save
 Generate 64bit x86-64 code
 
+mx32
+Target RejectNegative Negative(m32) Report Mask(ISA_X32) Var(ix86_isa_flags) Save
+Generate 32bit x86-64 code
+
 mmmx
 Target Report Mask(ISA_MMX) Var(ix86_isa_flags) Save
 Support MMX built-in functions
diff --git a/gcc/config/i386/linux64.h b/gcc/config/i386/linux64.h
index 9bf7eab..78c9c8e 100644
--- a/gcc/config/i386/linux64.h
+++ b/gcc/config/i386/linux64.h
@@ -26,3 +26,4 @@ see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
 
 #define GLIBC_DYNAMIC_LINKER32 "/lib/ld-linux.so.2"
 #define GLIBC_DYNAMIC_LINKER64 "/lib64/ld-linux-x86-64.so.2"
+#define GLIBC_DYNAMIC_LINKERX32 "/libx32/ld-linux-x32.so.2"
diff --git a/gcc/config/i386/t-linux64-x32 b/gcc/config/i386/t-linux64-x32
new file mode 100644
index 0000000..3a4d1de
--- /dev/null
+++ b/gcc/config/i386/t-linux64-x32
@@ -0,0 +1,34 @@
+# Copyright (C) 2011 Free Software Foundation, 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/>.
+
+# To support x86-64 and x32 libraries, the directory structrue
+# should be:
+#
+# 	/lib64 has x86-64 libraries.
+# 	/libx32 has x32 libraries.
+#
+MULTILIB_OPTIONS = m64/mx32
+MULTILIB_DIRNAMES = 64 x32
+MULTILIB_OSDIRNAMES = ../lib64 ../libx32
+
+LIBGCC = stmp-multilib
+INSTALL_LIBGCC = install-multilib
+
+EXTRA_MULTILIB_PARTS=crtbegin.o crtend.o crtbeginS.o crtendS.o \
+		     crtbeginT.o crtprec32.o crtprec64.o crtprec80.o \
+		     crtfastmath.o
diff --git a/gcc/config/i386/t-linuxx32 b/gcc/config/i386/t-linuxx32
new file mode 100644
index 0000000..92acf91
--- /dev/null
+++ b/gcc/config/i386/t-linuxx32
@@ -0,0 +1,42 @@
+# Copyright (C) 2011 Free Software Foundation, 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/>.
+
+# On Debian, Ubuntu and other derivative distributions, the 32bit libraries
+# are found in /lib32 and /usr/lib32, /lib64 and /usr/lib64 are symlinks to
+# /lib and /usr/lib, while other distributions install libraries into /lib64
+# and /usr/lib64.  The LSB does not enforce the use of /lib64 and /usr/lib64,
+# it doesn't tell anything about the 32bit libraries on those systems.  Set
+# MULTILIB_OSDIRNAMES according to what is found on the target.
+
+# To support i386, x86-64 and x32 libraries, the directory structrue
+# should be:
+#
+# 	/lib has i386 libraries.
+# 	/lib64 has x86-64 libraries.
+# 	/libx32 has x32 libraries.
+#
+MULTILIB_OPTIONS = m64/m32/mx32
+MULTILIB_DIRNAMES = 64 32 x32
+MULTILIB_OSDIRNAMES = ../lib64 $(if $(wildcard $(shell echo $(SYSTEM_HEADER_DIR))/../../usr/lib32),../lib32,../lib) ../libx32
+
+LIBGCC = stmp-multilib
+INSTALL_LIBGCC = install-multilib
+
+EXTRA_MULTILIB_PARTS=crtbegin.o crtend.o crtbeginS.o crtendS.o \
+		     crtbeginT.o crtprec32.o crtprec64.o crtprec80.o \
+		     crtfastmath.o
diff --git a/gcc/config/linux.h b/gcc/config/linux.h
index fc897b1..dbbeea5 100644
--- a/gcc/config/linux.h
+++ b/gcc/config/linux.h
@@ -77,9 +77,11 @@ see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
 #define UCLIBC_DYNAMIC_LINKER "/lib/ld-uClibc.so.0"
 #define UCLIBC_DYNAMIC_LINKER32 "/lib/ld-uClibc.so.0"
 #define UCLIBC_DYNAMIC_LINKER64 "/lib/ld64-uClibc.so.0"
+#define UCLIBC_DYNAMIC_LINKERX32 "/lib/ldx32-uClibc.so.0"
 #define BIONIC_DYNAMIC_LINKER "/system/bin/linker"
 #define BIONIC_DYNAMIC_LINKER32 "/system/bin/linker"
 #define BIONIC_DYNAMIC_LINKER64 "/system/bin/linker64"
+#define BIONIC_DYNAMIC_LINKERX32 "/system/bin/linkerx32"
 
 #define GNU_USER_DYNAMIC_LINKER						\
   CHOOSE_DYNAMIC_LINKER (GLIBC_DYNAMIC_LINKER, UCLIBC_DYNAMIC_LINKER,	\
@@ -90,6 +92,9 @@ see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
 #define GNU_USER_DYNAMIC_LINKER64					\
   CHOOSE_DYNAMIC_LINKER (GLIBC_DYNAMIC_LINKER64, UCLIBC_DYNAMIC_LINKER64, \
 			 BIONIC_DYNAMIC_LINKER64)
+#define GNU_USER_DYNAMIC_LINKERX32					\
+  CHOOSE_DYNAMIC_LINKER (GLIBC_DYNAMIC_LINKERX32, UCLIBC_DYNAMIC_LINKERX32, \
+			 BIONIC_DYNAMIC_LINKERX32)
 
 /* Determine whether the entire c99 runtime
    is present in the runtime library.  */
diff --git a/gcc/configure.ac b/gcc/configure.ac
index 5e41479..a421746 100644
--- a/gcc/configure.ac
+++ b/gcc/configure.ac
@@ -611,6 +611,16 @@ AC_ARG_ENABLE(multilib,
 [], [enable_multilib=yes])
 AC_SUBST(enable_multilib)
 
+# With x32 support
+AC_ARG_ENABLE(x32,
+[  --enable-x32            enable x32 library support for multiple ABIs],
+[], [enable_x32=no])
+
+# With ia32 support
+AC_ARG_ENABLE(ia32,
+[  --enable-ia32           enable ia32 library support for multiple ABIs],
+[], [enable_ia32=yes])
+
 # Enable __cxa_atexit for C++.
 AC_ARG_ENABLE(__cxa_atexit,
 [AS_HELP_STRING([--enable-__cxa_atexit], [enable __cxa_atexit for C++])],
diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
index a069042..12080ca 100644
--- a/gcc/doc/invoke.texi
+++ b/gcc/doc/invoke.texi
@@ -609,7 +609,7 @@ Objective-C and Objective-C++ Dialects}.
 -mpc32 -mpc64 -mpc80 -mstackrealign @gol
 -momit-leaf-frame-pointer  -mno-red-zone -mno-tls-direct-seg-refs @gol
 -mcmodel=@var{code-model} -mabi=@var{name} @gol
--m32  -m64 -mlarge-data-threshold=@var{num} @gol
+-m32 -m64 -mx32 -mlarge-data-threshold=@var{num} @gol
 -msse2avx -mfentry -m8bit-idiv @gol
 -mavx256-split-unaligned-load -mavx256-split-unaligned-store}
 
@@ -12824,14 +12824,18 @@ on AMD x86-64 processors in 64-bit environments.
 @table @gcctabopt
 @item -m32
 @itemx -m64
+@itemx -mx32
 @opindex m32
 @opindex m64
+@opindex mx32
 Generate code for a 32-bit or 64-bit environment.
-The 32-bit environment sets int, long and pointer to 32 bits and
+The -m32 option sets int, long and pointer to 32 bits and
 generates code that runs on any i386 system.
-The 64-bit environment sets int to 32 bits and long and pointer
-to 64 bits and generates code for AMD's x86-64 architecture. For
-darwin only the -m64 option turns off the @option{-fno-pic} and
+The -m64 option sets int to 32 bits and long and pointer
+to 64 bits and generates code for AMD's x86-64 architecture.
+The -mx32 option sets int, long and pointer to 32 bits and generates
+code for AMD's x86-64 architecture.
+For darwin only the -m64 option turns off the @option{-fno-pic} and
 @option{-mdynamic-no-pic} options.
 
 @item -mno-red-zone