Add support for x86_64-*-gnu-* targets to build x86_64 gnumach/hurd

Tested by building a toolchain and compiling gnumach for x86_64 [1].
This is the basic version without unwind support which I think is only
required to implement exceptions.

[1]
https://github.com/flavioc/cross-hurd/blob/master/bootstrap-kernel.sh.

gcc/ChangeLog:
	* config.gcc: Recognize x86_64-*-gnu* targets and include
	i386/gnu64.h.
	* config/i386/gnu64.h: Define configuration for new target
	including ld.so location.

libgcc/ChangeLog:
	* config.host: Recognize x86_64-*-gnu* targets.
	* config/i386/gnu-unwind.h: Update to handle __x86_64__ with a
	TODO for now.

Signed-off-by: Flavio Cruz <flaviocruz@gmail.com>

4 files changed, 61 insertions, 2 deletions

diff --git a/gcc/config.gcc b/gcc/config.gcc
index 744b46f..f0958e1 100644
--- a/gcc/config.gcc
+++ b/gcc/config.gcc
@@ -1971,7 +1971,7 @@ i[34567]86-*-linux* | i[34567]86-*-kfreebsd*-gnu | i[34567]86-*-gnu* | i[34567]8
 		;;
 	esac
 	;;
-x86_64-*-linux* | x86_64-*-kfreebsd*-gnu)
+x86_64-*-linux* | x86_64-*-kfreebsd*-gnu | x86_64-*-gnu*)
 	tm_file="${tm_file} i386/unix.h i386/att.h elfos.h gnu-user.h glibc-stdint.h \
 		 i386/x86-64.h i386/gnu-user-common.h i386/gnu-user64.h"
 	case ${target} in
@@ -1982,6 +1982,9 @@ x86_64-*-linux* | x86_64-*-kfreebsd*-gnu)
 	x86_64-*-kfreebsd*-gnu)
 		tm_file="${tm_file} kfreebsd-gnu.h i386/kfreebsd-gnu64.h"
 		;;
+	x86_64-*-gnu*)
+		tm_file="${tm_file} gnu.h i386/gnu64.h"
+		;;
 	esac
 	tmake_file="${tmake_file} i386/t-linux64"
 	x86_multilibs="${with_multilib_list}"
diff --git a/gcc/config/i386/gnu64.h b/gcc/config/i386/gnu64.h
new file mode 100644
index 0000000..a411f0e
--- /dev/null
+++ b/gcc/config/i386/gnu64.h
@@ -0,0 +1,40 @@
+/* Configuration for an x86_64 running GNU with ELF as the target machine.  */
+
+/*
+Copyright (C) 2023 Free Software Foundation, Inc.
+
+This file is part of GCC.
+
+GCC is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+
+GCC is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with GCC.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#define GNU_USER_LINK_EMULATION32 "elf_i386"
+#define GNU_USER_LINK_EMULATION64 "elf_x86_64"
+#define GNU_USER_LINK_EMULATIONX32 "elf32_x86_64"
+
+#undef GNU_USER_DYNAMIC_LINKER
+#define GNU_USER_DYNAMIC_LINKER32 "/lib/ld.so.1"
+#define GNU_USER_DYNAMIC_LINKER64 "/lib/ld-x86-64.so.1"
+#define GNU_USER_DYNAMIC_LINKERX32 "/lib/ld-x32.so.1"
+
+#undef	STARTFILE_SPEC
+#if defined HAVE_LD_PIE
+#define STARTFILE_SPEC \
+  "%{!shared: %{pg|p|profile:%{static:gcrt0.o%s;:gcrt1.o%s};pie:Scrt1.o%s;static:crt0.o%s;:crt1.o%s}} \
+   crti.o%s %{static:crtbeginT.o%s;shared|pie:crtbeginS.o%s;:crtbegin.o%s}"
+#else
+#define STARTFILE_SPEC \
+  "%{!shared: %{pg|p|profile:%{static:gcrt0.o%s;:gcrt1.o%s};static:crt0.o%s;:crt1.o%s}} \
+   crti.o%s %{static:crtbeginT.o%s;shared|pie:crtbeginS.o%s;:crtbegin.o%s}"
+#endif
diff --git a/libgcc/config.host b/libgcc/config.host
index 18fe2f9..70d47e0 100644
--- a/libgcc/config.host
+++ b/libgcc/config.host
@@ -751,6 +751,12 @@ x86_64-*-kfreebsd*-gnu)
 	tmake_file="${tmake_file} i386/t-crtpc t-crtfm i386/t-crtstuff t-dfprules"
 	tm_file="${tm_file} i386/elf-lib.h"
 	;;
+x86_64-*-gnu*)
+	extra_parts="$extra_parts crtprec32.o crtprec64.o crtprec80.o crtfastmath.o"
+	tmake_file="${tmake_file} i386/t-crtpc t-crtfm i386/t-crtstuff t-dfprules"
+	tm_file="${tm_file} i386/elf-lib.h"
+	md_unwind_header=i386/gnu-unwind.h
+	;;
 i[34567]86-pc-msdosdjgpp*)
 	;;
 i[34567]86-*-lynxos*)
@@ -1523,7 +1529,7 @@ esac
 case ${host} in
 i[34567]86-*-linux* | x86_64-*-linux* | \
   i[34567]86-*-kfreebsd*-gnu | x86_64-*-kfreebsd*-gnu | \
-  i[34567]86-*-gnu*)
+  i[34567]86-*-gnu* | x86_64-*-gnu*)
 	tmake_file="${tmake_file} t-tls i386/t-linux i386/t-msabi t-slibgcc-libgcc"
 	if test "$libgcc_cv_cfi" = "yes"; then
 		tmake_file="${tmake_file} t-stack i386/t-stack-i386"
diff --git a/libgcc/config/i386/gnu-unwind.h b/libgcc/config/i386/gnu-unwind.h
index 7cb1c7a..85aa2d6 100644
--- a/libgcc/config/i386/gnu-unwind.h
+++ b/libgcc/config/i386/gnu-unwind.h
@@ -30,6 +30,14 @@ see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
 
 #include <signal.h>
 
+#ifdef __x86_64__
+
+/*
+ * TODO: support for 64 bits needs to be implemented.
+ */
+
+#else /* ifdef __x86_64__  */
+
 #define MD_FALLBACK_FRAME_STATE_FOR x86_gnu_fallback_frame_state
 
 static _Unwind_Reason_Code
@@ -138,4 +146,6 @@ x86_gnu_fallback_frame_state
   return _URC_NO_REASON;
 }
 
+#endif /* ifdef __x86_64__  */
+
 #endif /* ifndef inhibit_libc */