* doc/invoke.texi (i386 Options): Document x86-64 options.

	(i386 and x86-64 Options): Rename i386 options section.

	* config/i386/i386.h (TARGET_UNWIND_INFO): New.
	(TARGET_SWITCHES): Add -munwind-info.
	(MASK_NO_UNWIND_INFO): New.
	(NO_BUILTIN_SIZE_TYPE, NO_BUILTIN_PTRDIFF_TYPE): Define for
	biarch compilation.
	(ASM_OUTPUT_DOUBLE_INT): New.

	* config/i386/linux64.h: New spec file for Linux x86-64 support.
	* config.gcc: Fix tm_file settings for x86-64.
	* config/i386/x86-64.h: New file with OS independent x86-64
	definitions.
	* config/i386/biarch64.h: New file used to configure compiler
	to biarch/64bit compilation.

	* config/i386/i386.c: (override_options): Set flags default
	for 64bit compilation.

	* i386.c (legitimize_pic_address): Add missing bits of 64bit support.
	(ix86_expand_int_movcc): Optimize DImode conditional moves with
	constants on x86_64.
	(ix86_attr_length_immediate_default): Support MODE_DI.
	* i386.md (fixdi splitter): Add missing "&& 1" in splitter
	condition.
	(indirect_jump, tablejump): Turn into expander.


git-svn-id: https://gcc.gnu.org/svn/gcc/trunk@45946 138bc75d-0d04-0410-961f-82ee72b054a4

10 files changed, 430 insertions, 70 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 72e101e6d4f..5f4c223b497 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,37 @@
+Tue Oct  2 12:46:01 CEST 2001  Bo Thorsen     <bo@suse.co.uk>,
+			       Andreas Jaeger <aj@suse.de>,
+			       Jan Hubicka    <jh@suse.cz>
+
+	* doc/invoke.texi (i386 Options): Document x86-64 options.
+	(i386 and x86-64 Options): Rename i386 options section.
+
+	* config/i386/i386.h (TARGET_UNWIND_INFO): New.
+	(TARGET_SWITCHES): Add -munwind-info.
+	(MASK_NO_UNWIND_INFO): New.
+	(NO_BUILTIN_SIZE_TYPE, NO_BUILTIN_PTRDIFF_TYPE): Define for
+	biarch compilation.
+	(ASM_OUTPUT_DOUBLE_INT): New.
+
+	* config/i386/linux64.h: New spec file for Linux x86-64 support.
+	* config.gcc: Fix tm_file settings for x86-64.
+	* config/i386/x86-64.h: New file with OS independent x86-64
+	definitions.
+	* config/i386/biarch64.h: New file used to configure compiler
+	to biarch/64bit compilation.
+
+	* config/i386/i386.c: (override_options): Set flags default
+	for 64bit compilation.
+
+Tue Oct  2 12:46:01 CEST 2001  Jan Hubicka  <jh@suse.cz>
+
+	* i386.c (legitimize_pic_address): Add missing bits of 64bit support.
+	(ix86_expand_int_movcc): Optimize DImode conditional moves with 
+	constants on x86_64.
+	(ix86_attr_length_immediate_default): Support MODE_DI.
+	* i386.md (fixdi splitter): Add missing "&& 1" in splitter
+	condition.
+	(indirect_jump, tablejump): Turn into expander.
+
 2001-10-02  Joseph S. Myers  <jsm28@cam.ac.uk>
 
 	* c-common.c (c_format_attribute_table): Make format and
diff --git a/gcc/config.gcc b/gcc/config.gcc
index d501991ee43..df86a7b937f 100644
--- a/gcc/config.gcc
+++ b/gcc/config.gcc
@@ -222,6 +222,9 @@ c*-convex-*)
 i[34567]86-*-*)
 	cpu_type=i386
 	;;
+x86_64-*-*)
+	cpu_type=i386
+	;;
 hppa*-*-* | parisc*-*-*)
 	cpu_type=pa
 	;;
@@ -1140,6 +1143,18 @@ i[34567]86-*-linux*)	# Intel 80386's running GNU/Linux
 		thread_file='posix'
 	fi
 	;;
+x86_64-*-linux*)
+	xmake_file=x-linux
+	tm_file="i386/biarch64.h i386/i386.h i386/att.h linux.h i386/x86-64.h \
+		 i386/linux64.h"
+	tmake_file="t-slibgcc-elf-ver t-linux i386/t-crtstuff"
+	extra_parts="crtbegin.o crtbeginS.o crtend.o crtendS.o"
+	gnu_ld=yes
+	float_format=i386
+	if test x$enable_threads = xyes; then
+		thread_file='posix'
+	fi
+	;;
 i[34567]86-*-gnu*)
 	float_format=i386
 	;;
diff --git a/gcc/config/i386/att.h b/gcc/config/i386/att.h
index b41218e387f..8f2a1ebb50d 100644
--- a/gcc/config/i386/att.h
+++ b/gcc/config/i386/att.h
@@ -32,6 +32,7 @@ Boston, MA 02111-1307, USA.  */
 
 #define ASM_SHORT "\t.value\t"
 #define ASM_LONG "\t.long\t"
+#define ASM_QUAD "\t.quad\t"
 
 /* How to output an ASCII string constant.  */
 
diff --git a/gcc/config/i386/biarch64.h b/gcc/config/i386/biarch64.h
new file mode 100644
index 00000000000..e2a5d917f80
--- /dev/null
+++ b/gcc/config/i386/biarch64.h
@@ -0,0 +1,25 @@
+/* Make configure files to produce biarch compiler defaulting to 64bit mode.
+   This file must be included very first, while the OS specific file later
+   to overwrite otherwise wrong defaults. 
+   Copyright (C) 2001 Free Software Foundation, Inc.
+   Contributed by Bo Thorsen <bo@suse.de>.
+
+This file is part of GNU CC.
+
+GNU CC 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 2, or (at your option)
+any later version.
+
+GNU CC 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 GNU CC; see the file COPYING.  If not, write to
+the Free Software Foundation, 59 Temple Place - Suite 330,
+Boston, MA 02111-1307, USA.  */
+
+#define TARGET_64BIT_DEFAULT
+#define TARGET_BI_ARCH
diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c
index 75e19682dde..7e65b0e9164 100644
--- a/gcc/config/i386/i386.c
+++ b/gcc/config/i386/i386.c
@@ -984,6 +984,16 @@ override_options ()
   if (flag_unsafe_math_optimizations)
     target_flags &= ~MASK_IEEE_FP;
 
+  if (TARGET_64BIT)
+    {
+      if (TARGET_ALIGN_DOUBLE)
+	error ("-malign-double makes no sense in the 64bit mode.");
+      if (TARGET_RTD)
+	error ("-mrtd calling convention not supported in the 64bit mode.");
+      /* Enable by default the SSE and MMX builtins.  */
+      target_flags |= MASK_SSE2 | MASK_SSE | MASK_MMX | MASK_128BIT_LONG_DOUBLE;
+     }
+
   /* It makes no sense to ask for just SSE builtins, so MMX is also turned
      on by -msse.  */
   if (TARGET_SSE)
@@ -2214,7 +2224,7 @@ ix86_setup_incoming_varargs (cum, mode, type, pretend_size, no_rtl)
       emit_insn (gen_rtx_SET(VOIDmode, tmp_reg,
 			     plus_constant (save_area, 8 * REGPARM_MAX + 127)));
       mem = gen_rtx_MEM (BLKmode, plus_constant (tmp_reg, -127));
-      set_mem_alias_set(mem, set);
+      set_mem_alias_set (mem, set);
 
       /* And finally do the dirty job!  */
       emit_insn (gen_sse_prologue_save (mem, nsse_reg, GEN_INT (next_cum.sse_regno),
@@ -2260,7 +2270,7 @@ ix86_va_start (stdarg_p, valist, nextarg)
 
   if (TARGET_DEBUG_ARG)
     fprintf (stderr, "va_start: words = %d, n_gpr = %d, n_fpr = %d\n",
-	     words, n_gpr, n_fpr);
+	     (int)words, (int)n_gpr, (int)n_fpr);
 
   t = build (MODIFY_EXPR, TREE_TYPE (gpr), gpr,
 	     build_int_2 (n_gpr * 8, 0));
@@ -4735,37 +4745,63 @@ legitimize_pic_address (orig, reg)
 
   if (local_symbolic_operand (addr, Pmode))
     {
-      /* This symbol may be referenced via a displacement from the PIC
-	 base address (@GOTOFF).  */
+      /* In 64bit mode we can address such objects directly.  */
+      if (TARGET_64BIT)
+	new = addr;
+      else
+	{
+	  /* This symbol may be referenced via a displacement from the PIC
+	     base address (@GOTOFF).  */
 
-      current_function_uses_pic_offset_table = 1;
-      new = gen_rtx_UNSPEC (Pmode, gen_rtvec (1, addr), 7);
-      new = gen_rtx_CONST (Pmode, new);
-      new = gen_rtx_PLUS (Pmode, pic_offset_table_rtx, new);
+	  current_function_uses_pic_offset_table = 1;
+	  new = gen_rtx_UNSPEC (Pmode, gen_rtvec (1, addr), 7);
+	  new = gen_rtx_CONST (Pmode, new);
+	  new = gen_rtx_PLUS (Pmode, pic_offset_table_rtx, new);
 
-      if (reg != 0)
-	{
-	  emit_move_insn (reg, new);
-	  new = reg;
-	}
+	  if (reg != 0)
+	    {
+	      emit_move_insn (reg, new);
+	      new = reg;
+	    }
+      	}
     }
   else if (GET_CODE (addr) == SYMBOL_REF)
     {
-      /* This symbol must be referenced via a load from the
-	 Global Offset Table (@GOT).  */
+      if (TARGET_64BIT)
+	{
+	  current_function_uses_pic_offset_table = 1;
+	  new = gen_rtx_UNSPEC (Pmode, gen_rtvec (1, addr), 15);
+	  new = gen_rtx_CONST (Pmode, new);
+	  new = gen_rtx_MEM (Pmode, new);
+	  RTX_UNCHANGING_P (new) = 1;
+	  set_mem_alias_set (new, ix86_GOT_alias_set ());
+
+	  if (reg == 0)
+	    reg = gen_reg_rtx (Pmode);
+	  /* Use directly gen_movsi, otherwise the address is loaded
+	     into register for CSE.  We don't want to CSE this addresses,
+	     instead we CSE addresses from the GOT table, so skip this.  */
+	  emit_insn (gen_movsi (reg, new));
+	  new = reg;
+	}
+      else
+	{
+	  /* This symbol must be referenced via a load from the
+	     Global Offset Table (@GOT).  */
 
-      current_function_uses_pic_offset_table = 1;
-      new = gen_rtx_UNSPEC (Pmode, gen_rtvec (1, addr), 6);
-      new = gen_rtx_CONST (Pmode, new);
-      new = gen_rtx_PLUS (Pmode, pic_offset_table_rtx, new);
-      new = gen_rtx_MEM (Pmode, new);
-      RTX_UNCHANGING_P (new) = 1;
-      set_mem_alias_set (new, ix86_GOT_alias_set ());
+	  current_function_uses_pic_offset_table = 1;
+	  new = gen_rtx_UNSPEC (Pmode, gen_rtvec (1, addr), 6);
+	  new = gen_rtx_CONST (Pmode, new);
+	  new = gen_rtx_PLUS (Pmode, pic_offset_table_rtx, new);
+	  new = gen_rtx_MEM (Pmode, new);
+	  RTX_UNCHANGING_P (new) = 1;
+	  set_mem_alias_set (new, ix86_GOT_alias_set ());
 
-      if (reg == 0)
-	reg = gen_reg_rtx (Pmode);
-      emit_move_insn (reg, new);
-      new = reg;
+	  if (reg == 0)
+	    reg = gen_reg_rtx (Pmode);
+	  emit_move_insn (reg, new);
+	  new = reg;
+	}
     }
   else
     {
@@ -5141,7 +5177,13 @@ i386_dwarf_output_addr_const (file, x)
      FILE *file;
      rtx x;
 {
+#ifdef ASM_QUAD
+  fprintf (file, "%s", TARGET_64BIT ? ASM_QUAD : INT_ASM_OP);
+#else
+  if (TARGET_64BIT)
+    abort ();
   fprintf (file, "%s", INT_ASM_OP);
+#endif
   if (flag_pic)
     output_pic_addr_const (file, x, '\0');
   else
@@ -7823,7 +7865,7 @@ ix86_expand_int_movcc (operands)
      HImode insns, we'd be swallowed in word prefix ops.  */
 
   if (GET_MODE (operands[0]) != HImode
-      && GET_MODE (operands[0]) != DImode
+      && (GET_MODE (operands[0]) != DImode || TARGET_64BIT)
       && GET_CODE (operands[2]) == CONST_INT
       && GET_CODE (operands[3]) == CONST_INT)
     {
@@ -7852,10 +7894,13 @@ ix86_expand_int_movcc (operands)
 
 	  if (reg_overlap_mentioned_p (out, ix86_compare_op0)
 	      || reg_overlap_mentioned_p (out, ix86_compare_op1))
-	    tmp = gen_reg_rtx (SImode);
+	    tmp = gen_reg_rtx (GET_MODE (operands[0]));
 
 	  emit_insn (compare_seq);
-	  emit_insn (gen_x86_movsicc_0_m1 (tmp));
+	  if (GET_MODE (tmp) == DImode)
+	    emit_insn (gen_x86_movdicc_0_m1_rex64 (tmp));
+	  else
+	    emit_insn (gen_x86_movsicc_0_m1 (tmp));
 
 	  if (diff == 1)
 	    {
@@ -7867,7 +7912,12 @@ ix86_expand_int_movcc (operands)
 	       * Size 5 - 8.
 	       */
 	      if (ct)
-	        emit_insn (gen_addsi3 (tmp, tmp, GEN_INT (ct)));
+		{
+		  if (GET_MODE (tmp) == DImode)
+	            emit_insn (gen_adddi3 (tmp, tmp, GEN_INT (ct)));
+		  else
+	            emit_insn (gen_addsi3 (tmp, tmp, GEN_INT (ct)));
+		}
 	    }
 	  else if (cf == -1)
 	    {
@@ -7878,7 +7928,10 @@ ix86_expand_int_movcc (operands)
 	       *
 	       * Size 8.
 	       */
-	      emit_insn (gen_iorsi3 (tmp, tmp, GEN_INT (ct)));
+	      if (GET_MODE (tmp) == DImode)
+		emit_insn (gen_iordi3 (tmp, tmp, GEN_INT (ct)));
+	      else
+		emit_insn (gen_iorsi3 (tmp, tmp, GEN_INT (ct)));
 	    }
 	  else if (diff == -1 && ct)
 	    {
@@ -7890,9 +7943,18 @@ ix86_expand_int_movcc (operands)
 	       *
 	       * Size 8 - 11.
 	       */
-	      emit_insn (gen_one_cmplsi2 (tmp, tmp));
-	      if (cf)
-	        emit_insn (gen_addsi3 (tmp, tmp, GEN_INT (cf)));
+	      if (GET_MODE (tmp) == DImode)
+	        {
+		  emit_insn (gen_one_cmpldi2 (tmp, tmp));
+		  if (cf)
+		    emit_insn (gen_adddi3 (tmp, tmp, GEN_INT (cf)));
+		}
+	      else
+	        {
+		  emit_insn (gen_one_cmplsi2 (tmp, tmp));
+		  if (cf)
+		    emit_insn (gen_addsi3 (tmp, tmp, GEN_INT (cf)));
+		}
 	    }
 	  else
 	    {
@@ -7904,10 +7966,20 @@ ix86_expand_int_movcc (operands)
 	       *
 	       * Size 8 - 11.
 	       */
-	      emit_insn (gen_andsi3 (tmp, tmp, GEN_INT (trunc_int_for_mode
-							(cf - ct, SImode))));
-	      if (ct)
-	        emit_insn (gen_addsi3 (tmp, tmp, GEN_INT (ct)));
+	      if (GET_MODE (tmp) == DImode)
+	        {
+		  emit_insn (gen_anddi3 (tmp, tmp, GEN_INT (trunc_int_for_mode
+							    (cf - ct, DImode))));
+		  if (ct)
+		    emit_insn (gen_adddi3 (tmp, tmp, GEN_INT (ct)));
+		}
+	      else
+	        {
+		  emit_insn (gen_andsi3 (tmp, tmp, GEN_INT (trunc_int_for_mode
+							    (cf - ct, SImode))));
+		  if (ct)
+		    emit_insn (gen_addsi3 (tmp, tmp, GEN_INT (ct)));
+		}
 	    }
 
 	  if (tmp != out)
@@ -7961,43 +8033,28 @@ ix86_expand_int_movcc (operands)
 	  /* On x86_64 the lea instruction operates on Pmode, so we need to get arithmetics
 	     done in proper mode to match.  */
 	  if (diff == 1)
-	    {
-	      if (Pmode != SImode)
-		tmp = gen_lowpart (Pmode, out);
-	      else
-		tmp = out;
-	    }
+	    tmp = out;
 	  else
 	    {
 	      rtx out1;
-	      if (Pmode != SImode)
-	        out1 = gen_lowpart (Pmode, out);
-	      else
-		out1 = out;
-	      tmp = gen_rtx_MULT (Pmode, out1, GEN_INT (diff & ~1));
+	      out1 = out;
+	      tmp = gen_rtx_MULT (GET_MODE (out), out1, GEN_INT (diff & ~1));
 	      nops++;
 	      if (diff & 1)
 		{
-		  tmp = gen_rtx_PLUS (Pmode, tmp, out1);
+		  tmp = gen_rtx_PLUS (GET_MODE (out), tmp, out1);
 		  nops++;
 		}
 	    }
 	  if (cf != 0)
 	    {
-	      tmp = gen_rtx_PLUS (Pmode, tmp, GEN_INT (cf));
+	      tmp = gen_rtx_PLUS (GET_MODE (out), tmp, GEN_INT (cf));
 	      nops++;
 	    }
 	  if (tmp != out
 	      && (GET_CODE (tmp) != SUBREG || SUBREG_REG (tmp) != out))
 	    {
-	      if (Pmode != SImode)
-	        tmp = gen_rtx_SUBREG (SImode, tmp, 0);
-
-	      /* ??? We should to take care for outputing non-lea arithmetics
-	         for Pmode != SImode case too, but it is quite tricky and not
-	         too important, since all TARGET_64BIT machines support real
-	         conditional moves.  */
-	      if (nops == 1 && Pmode == SImode)
+	      if (nops == 1)
 		{
 		  rtx clob;
 
@@ -9694,6 +9751,10 @@ ix86_attr_length_immediate_default (insn, shortform)
 		case MODE_SI:
 		  len+=4;
 		  break;
+		/* Immediates for DImode instructions are encoded as 32bit sign extended values.  */
+		case MODE_DI:
+		  len+=4;
+		  break;
 		default:
 		  fatal_insn ("Unknown insn mode", insn);
 	      }
diff --git a/gcc/config/i386/i386.h b/gcc/config/i386/i386.h
index fc6f1c93861..174c59452a0 100644
--- a/gcc/config/i386/i386.h
+++ b/gcc/config/i386/i386.h
@@ -484,6 +484,11 @@ extern int ix86_arch;
 #endif
 #endif /* CPP_CPU_DEFAULT_SPEC */
 
+#ifdef TARGET_BI_ARCH
+#define NO_BUILTIN_SIZE_TYPE
+#define NO_BUILTIN_PTRDIFF_TYPE
+#endif
+
 #ifdef NO_BUILTIN_SIZE_TYPE
 #define CPP_CPU32_SIZE_TYPE_SPEC \
   " -D__SIZE_TYPE__=unsigned\\ int -D__PTRDIFF_TYPE__=int"
@@ -653,7 +658,7 @@ extern int ix86_arch;
    the stack, which results in aligned frames for functions called from
    main, though it does nothing for the alignment of main itself.  */
 #define FORCE_PREFERRED_STACK_BOUNDARY_IN_MAIN \
-  (ix86_preferred_stack_boundary > STACK_BOUNDARY)
+  (ix86_preferred_stack_boundary > STACK_BOUNDARY && !TARGET_64BIT)
 
 /* Allocation boundary for the code of a function. */
 #define FUNCTION_BOUNDARY 16
@@ -2910,6 +2915,11 @@ do { long l;						\
   output_addr_const (FILE,(VALUE)),		\
   putc('\n',FILE))
 
+#define ASM_OUTPUT_DOUBLE_INT(FILE,VALUE)  \
+( fprintf (FILE, "%s\t", ASM_QUAD),		\
+  output_addr_const (FILE,(VALUE)),		\
+  putc('\n',FILE))
+
 /* Likewise for `char' and `short' constants.  */
 
 #define ASM_OUTPUT_SHORT(FILE,VALUE)  \
diff --git a/gcc/config/i386/i386.md b/gcc/config/i386/i386.md
index 3b98788b67a..c2e05cb8d92 100644
--- a/gcc/config/i386/i386.md
+++ b/gcc/config/i386/i386.md
@@ -4688,7 +4688,7 @@
    && !reload_completed && !reload_in_progress
    && (!SSE_FLOAT_MODE_P (GET_MODE (operands[1])) || !TARGET_64BIT)"
   "#"
-  ""
+  "&& 1"
   [(const_int 0)]
 {
   operands[2] = assign_386_stack_local (HImode, 1);
@@ -12956,9 +12956,21 @@
   "jmp\t%l0"
   [(set_attr "type" "ibr")])
 
-(define_insn "indirect_jump"
-  [(set (pc) (match_operand:P 0 "nonimmediate_operand" "rm"))]
+(define_expand "indirect_jump"
+  [(set (pc) (match_operand 0 "nonimmediate_operand" "rm"))]
   ""
+  "")
+
+(define_insn "*indirect_jump"
+  [(set (pc) (match_operand:SI 0 "nonimmediate_operand" "rm"))]
+  "!TARGET_64BIT"
+  "jmp\t%A0"
+  [(set_attr "type" "ibr")
+   (set_attr "length_immediate" "0")])
+
+(define_insn "*indirect_jump_rtx64"
+  [(set (pc) (match_operand:DI 0 "nonimmediate_operand" "rm"))]
+  "TARGET_64BIT"
   "jmp\t%A0"
   [(set_attr "type" "ibr")
    (set_attr "length_immediate" "0")])
@@ -12989,7 +13001,15 @@
 (define_insn "*tablejump_1"
   [(set (pc) (match_operand:SI 0 "nonimmediate_operand" "rm"))
    (use (label_ref (match_operand 1 "" "")))]
-  ""
+  "!TARGET_64BIT"
+  "jmp\t%A0"
+  [(set_attr "type" "ibr")
+   (set_attr "length_immediate" "0")])
+
+(define_insn "*tablejump_1_rtx64"
+  [(set (pc) (match_operand:DI 0 "nonimmediate_operand" "rm"))
+   (use (label_ref (match_operand 1 "" "")))]
+  "TARGET_64BIT"
   "jmp\t%A0"
   [(set_attr "type" "ibr")
    (set_attr "length_immediate" "0")])
diff --git a/gcc/config/i386/linux64.h b/gcc/config/i386/linux64.h
new file mode 100644
index 00000000000..529c3014290
--- /dev/null
+++ b/gcc/config/i386/linux64.h
@@ -0,0 +1,48 @@
+/* Definitions for AMD x86-64 running Linux-based GNU systems with ELF format.
+   Copyright (C) 2001 Free Software Foundation, Inc.
+   Contributed by Jan Hubicka <jh@suse.cz>, based on linux.h.
+
+This file is part of GNU CC.
+
+GNU CC 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 2, or (at your option)
+any later version.
+
+GNU CC 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 GNU CC; see the file COPYING.  If not, write to
+the Free Software Foundation, 59 Temple Place - Suite 330,
+Boston, MA 02111-1307, USA.  */
+
+#define LINUX_DEFAULT_ELF
+
+#undef TARGET_VERSION
+#define TARGET_VERSION fprintf (stderr, " (x86-64 Linux/ELF)");
+
+#undef CPP_PREDEFINES
+#define CPP_PREDEFINES "-D__ELF__ -Dunix -Dlinux -Asystem(posix)"
+
+#undef CPP_SPEC
+#define CPP_SPEC "%(cpp_cpu) %{fPIC:-D__PIC__ -D__pic__} %{fpic:-D__PIC__ -D__pic__} %{posix:-D_POSIX_SOURCE} %{pthread:-D_REENTRANT} %{!m32:-D__LONG_MAX__=9223372036854775807L}"
+
+/* Provide a LINK_SPEC.  Here we provide support for the special GCC
+   options -static and -shared, which allow us to link things in one
+   of these three modes by applying the appropriate combinations of
+   options at link-time.
+
+   When the -shared link option is used a final link is not being
+   done.  */
+
+#undef	LINK_SPEC
+#define LINK_SPEC "%{!m32:-m elf_x86_64} %{m32:-m elf_i386} {shared:-shared} \
+  %{!shared: \
+    %{!static: \
+      %{rdynamic:-export-dynamic} \
+      %{!dynamic-linker:-dynamic-linker /lib/ld64.so.1}} \
+      %{static:-static}}"
+
diff --git a/gcc/config/i386/x86-64.h b/gcc/config/i386/x86-64.h
new file mode 100644
index 00000000000..baf5b2488dc
--- /dev/null
+++ b/gcc/config/i386/x86-64.h
@@ -0,0 +1,118 @@
+/* OS independent definitions for AMD x86-64.
+   Copyright (C) 2001 Free Software Foundation, Inc.
+   Contributed by Bo Thorsen <bo@suse.de>.
+
+This file is part of GNU CC.
+
+GNU CC 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 2, or (at your option)
+any later version.
+
+GNU CC 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 GNU CC; see the file COPYING.  If not, write to
+the Free Software Foundation, 59 Temple Place - Suite 330,
+Boston, MA 02111-1307, USA.  */
+
+/* The svr4 ABI for the i386 says that records and unions are returned
+   in memory.  */
+#undef DEFAULT_PCC_STRUCT_RETURN
+#define DEFAULT_PCC_STRUCT_RETURN 1
+
+#undef ASM_COMMENT_START
+#define ASM_COMMENT_START "#"
+
+/* This is how to output an element of a case-vector that is relative.
+   This is only used for PIC code.  See comments by the `casesi' insn in
+   i386.md for an explanation of the expression this outputs. */
+#undef ASM_OUTPUT_ADDR_DIFF_ELT
+#define ASM_OUTPUT_ADDR_DIFF_ELT(FILE, BODY, VALUE, REL) \
+  if (TARGET_64BIT) \
+    fprintf (FILE, "\t.long %s%d-.+4+(.-%s%d)\n", LPREFIX, VALUE, LPREFIX, REL); \
+  else	\
+    fprintf (FILE, "\t.long _GLOBAL_OFFSET_TABLE_+[.-%s%d]\n", LPREFIX, VALUE)
+
+/* Indicate that jump tables go in the text section.  This is
+   necessary when compiling PIC code.  */
+#define JUMP_TABLES_IN_TEXT_SECTION (flag_pic && !TARGET_64BIT)
+
+#undef DBX_REGISTER_NUMBER
+#define DBX_REGISTER_NUMBER(n) \
+  (TARGET_64BIT ? dbx64_register_map[n] : svr4_dbx_register_map[n])
+
+/* Output assembler code to FILE to call the profiler.  */
+#define NO_PROFILE_COUNTERS
+
+#undef FUNCTION_PROFILER
+#define FUNCTION_PROFILER(FILE, LABELNO)  \
+{									\
+  if (TARGET_64BIT && flag_pic)						\
+    fprintf (FILE, "\tcall\t*mcount@PLT\n");				\
+  else if (flag_pic)							\
+    fprintf (FILE, "\tcall\t*mcount@GOT(%%ebx)\n");			\
+  else									\
+    fprintf (FILE, "\tcall\tmcount\n");					\
+}
+
+#undef SIZE_TYPE
+#define SIZE_TYPE (TARGET_64BIT ? "long unsigned int" : "unsigned int")
+
+#undef PTRDIFF_TYPE
+#define PTRDIFF_TYPE (TARGET_64BIT ? "long int" : "int")
+
+#undef WCHAR_TYPE
+#define WCHAR_TYPE "int"
+
+#undef WCHAR_TYPE_SIZE
+#define WCHAR_TYPE_SIZE 32
+
+#undef CC1_SPEC
+#define CC1_SPEC "%(cc1_cpu) %{profile:-p}"
+
+#undef ASM_SPEC
+#define ASM_SPEC "%{v:-V} %{Qy:} %{!Qn:-Qy} %{n} %{T} %{Ym,*} %{Yd,*} \
+ %{Wa,*:%*} %{m32:--32}"
+
+/* A C statement (sans semicolon) to output to the stdio stream
+   FILE the assembler definition of uninitialized global DECL named
+   NAME whose size is SIZE bytes and alignment is ALIGN bytes.
+   Try to use asm_output_aligned_bss to implement this macro.  */
+
+#define ASM_OUTPUT_ALIGNED_BSS(FILE, DECL, NAME, SIZE, ALIGN) \
+  asm_output_aligned_bss (FILE, DECL, NAME, SIZE, ALIGN)
+
+/* A C statement to output to the stdio stream FILE an assembler
+   command to advance the location counter to a multiple of 1<<LOG
+   bytes if it is within MAX_SKIP bytes.
+
+   This is used to align code labels according to Intel recommendations.  */
+
+#ifdef HAVE_GAS_MAX_SKIP_P2ALIGN
+#define ASM_OUTPUT_MAX_SKIP_ALIGN(FILE,LOG,MAX_SKIP)			\
+  do {									\
+    if ((LOG) != 0) {							\
+      if ((MAX_SKIP) == 0) fprintf ((FILE), "\t.p2align %d\n", (LOG));	\
+      else fprintf ((FILE), "\t.p2align %d,,%d\n", (LOG), (MAX_SKIP));	\
+    }									\
+  } while (0)
+#endif
+
+
+/* i386 System V Release 4 uses DWARF debugging info.
+   x86-64 ABI specifies DWARF2.  */
+
+#undef DWARF2_DEBUGGING_INFO
+#undef DWARF_DEBUGGING_INFO
+#define DWARF2_DEBUGGING_INFO
+#define DWARF2_UNWIND_INFO 1
+/* Incorrectly autodetected in cross compilation.  */
+#undef HAVE_AS_DWARF2_DEBUG_LINE
+#define HAVE_AS_DWARF2_DEBUG_LINE
+
+#undef PREFERRED_DEBUGGING_TYPE
+#define PREFERRED_DEBUGGING_TYPE DWARF2_DEBUG
diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
index b3a731a3266..8499d72bac6 100644
--- a/gcc/doc/invoke.texi
+++ b/gcc/doc/invoke.texi
@@ -464,7 +464,7 @@ in the following sections.
 -mabi=32  -mabi=n32  -mabi=64  -mabi=eabi @gol
 -mfix7000  -mno-crt0}
 
-@emph{i386 Options}
+@emph{i386 and x86-64 Options}
 @gccoptlist{
 -mcpu=@var{cpu-type}  -march=@var{cpu-type} @gol
 -mintel-syntax -mieee-fp  -mno-fancy-math-387 @gol
@@ -474,7 +474,9 @@ in the following sections.
 -mmmx  -msse  -m3dnow @gol
 -mthreads  -mno-align-stringops  -minline-all-stringops @gol
 -mpush-args  -maccumulate-outgoing-args  -m128bit-long-double @gol
--m96bit-long-double  -mregparm=@var{num}  -momit-leaf-frame-pointer}
+-m96bit-long-double  -mregparm=@var{num}  -momit-leaf-frame-pointer @gol
+-mno-red-zone@gol
+-m32 -m64}
 
 @emph{HPPA Options}
 @gccoptlist{
@@ -5077,7 +5079,7 @@ that macro, which enables you to change the defaults.
 * RS/6000 and PowerPC Options::
 * RT Options::
 * MIPS Options::
-* i386 Options::
+* i386 and x86-64 Options::
 * HPPA Options::
 * Intel 960 Options::
 * DEC Alpha Options::
@@ -7418,12 +7420,15 @@ options is also defined by that macro, which enables you to change the
 defaults.
 @end ifset
 
-@node i386 Options
-@subsection Intel 386 Options
+@node i386 and x86-64 Options
+@subsection Intel 386 and AMD x86-64 Options
 @cindex i386 Options
+@cindex x86-64 Options
 @cindex Intel 386 Options
+@cindex AMD x86-64 Options
 
-These @samp{-m} options are defined for the i386 family of computers:
+These @samp{-m} options are defined for the i386 and x86-64 family of
+computers:
 
 @table @gcctabopt
 @item -mcpu=@var{cpu-type}
@@ -8027,6 +8032,29 @@ makes an extra register available in leaf functions.  The option
 which might make debugging harder.
 @end table
 
+These @samp{-m} switches are supported in addition to the above
+on AMD x86-64 processors in 64-bit environments.
+
+@table @gcctabopt
+@item -m32
+@itemx -m64
+@opindex m32
+@opindex m64
+Generate code for a 32-bit or 64-bit environment.
+The 32-bit environment 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.
+
+@item -mno-red-zone
+@opindex no-red-zone
+Do not use a so called red zone for x86-64 code.  The red zone is mandated
+by the x86-64 ABI, it is a 128-byte area beyond the location of the
+stack pointer that will not be modified by signal or interrupt handlers
+and therefore can be used for temporary data without adjusting the stack
+pointer.  The flag @option{-mno-red-zone} disables this red zone.
+@end table
+
 @node HPPA Options
 @subsection HPPA Options
 @cindex HPPA Options