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make -march=native available even in some cross compiles

The previous version of this code would make -mcpu=native available
only when the host and target were exactly the same.  This patch
expands it to make -mcpu=native available whenever the host and target
are both x86 or x86_64 platforms.

This fixes a regression where

.../configure --target=i386-apple-darwin \
--with-sysroot=/Developer/SDKs/MacOSX10.4u.sdk --with-as=/usr/bin/as \

on a powerpc-darwin system would fail to link xgcc because
host_detect_local_cpu was undefined, by making it not required.  It
also fixes a similar regression with the same command-line on an
i386-darwin system, but in that case by causing host_detect_local_cpu
to be defined.

Tested by building after the above configure command.
- Geoffrey Keating <>

===File ~/patches/gcc-i386-alwayshostdetect.patch===========
2006-09-22  Geoffrey Keating  <>

	* config/i386/driver-i386.c: Always define host_detect_local_cpu.
	* config/i386/i386.h: Define EXTRA_SPEC_FUNCTIONS on any i386
	or x86_64 host.  Define HAVE_LOCAL_CPU_DETECT.
	(CC1_CPU_SPEC): Make conditional on HAVE_LOCAL_CPU_DETECT rather
	than replicating condition above.
	* (i[34567]86-*-*): Always use driver-i386.o.

---	(revision 117150)
+++	(working copy)
@@ -97,11 +97,8 @@
 case ${host} in
   i[34567]86-*-* \
   | x86_64-*-* )
-    # include the support for -march=native only when not cross compiling
-    if test x${host} = x${target} ; then
-      host_extra_gcc_objs="driver-i386.o"
-      host_xmake_file="${host_xmake_file} i386/x-i386"
-    fi
+    host_extra_gcc_objs="driver-i386.o"
+    host_xmake_file="${host_xmake_file} i386/x-i386"
Index: config/i386/i386.h
--- config/i386/i386.h	(revision 117150)
+++ config/i386/i386.h	(working copy)
@@ -274,12 +274,15 @@
   optimization_options ((LEVEL), (SIZE))
-/* -march=native handling only makes sense with a native compiler.  */
+/* -march=native handling only makes sense with compiler running on
+   an x86 or x86_64 chip.  If changing this condition, also change
+   the condition in driver-i386.c.  */
+#if defined(__i386__) || defined(__x86_64__)
 /* In driver-i386.c.  */
 extern const char *host_detect_local_cpu (int argc, const char **argv);
   { "local_cpu_detect", host_detect_local_cpu },
 /* Support for configure-time defaults of some command line options.
@@ -311,7 +314,7 @@
 %{mno-intel-syntax:-masm=att \
 %n`-mno-intel-syntax' is deprecated. Use `-masm=att' instead.\n}"
 #define CC1_CPU_SPEC CC1_CPU_SPEC_1
 #define CC1_CPU_SPEC CC1_CPU_SPEC_1 \
Index: config/i386/driver-i386.c
--- config/i386/driver-i386.c	(revision 117150)
+++ config/i386/driver-i386.c	(working copy)
@@ -22,11 +22,6 @@
 #include "system.h"
 #include <stdlib.h>
-/* This file shouldn't even be included in a cross compiler, but
-   let's be sure.  */
-extern const char *host_detect_local_cpu (int argc, const char **argv);
 #define cpuid(num,a,b,c,d) \
   asm volatile ("xchgl %%ebx, %1; cpuid; xchgl %%ebx, %1" \
@@ -170,5 +165,4 @@
   return concat ("-m", argv[0], "=i386", NULL);
+#endif /* GCC_VERSION */

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