Native detection works on 32 and 64bit x86 cpus yet.

Allowed native 32bit code generation when running on 64bit x86.
Removed ebx save, gcc should handle this.
Enable native detection on windows again.

[r28179]

ir/be/ia32/ia32_architecture.c

 /*
- * Copyright (C) 1995-2008 University of Karlsruhe.  All right reserved.
+ * Copyright (C) 1995-2010 University of Karlsruhe.  All right reserved.
  *
  * This file is part of libFirm.
  *
@@ -33,8 +33,17 @@
 #include "bearch_ia32_t.h"
 #include "ia32_architecture.h"
 
+#undef NATIVE_X86
+
 #ifdef _MSC_VER
+#if defined(_M_IX86) || defined(_M_X64)
 #include <intrin.h>
+#define NATIVE_X86
+#endif
+#else
+#if defined(__i386__) || defined(__x86_64__)
+#define NATIVE_X86
+#endif
 #endif
 
 ia32_code_gen_config_t  ia32_cg_config;
@@ -492,9 +501,9 @@ int ia32_evaluate_insn(insn_kind kind, const ir_mode *mode, ir_tarval *tv)
 	}
 }
 
-/* autodetection code only works if we're on an x86 cpu obviously */
-#ifdef __i386__
-typedef struct cpu_info_t {
+/* auto detection code only works if we're on an x86 cpu obviously */
+#ifdef NATIVE_X86
+typedef struct x86_cpu_info_t {
 	unsigned char cpu_stepping;
 	unsigned char cpu_model;
 	unsigned char cpu_family;
@@ -504,9 +513,9 @@ typedef struct cpu_info_t {
 	unsigned      edx_features;
 	unsigned      ecx_features;
 	unsigned      add_features;
-} cpu_info_t;
+} x86_cpu_info_t;
 
-static cpu_support auto_detect_Intel(cpu_info_t const *info)
+static cpu_support auto_detect_Intel(x86_cpu_info_t const *info)
 {
 	cpu_support auto_arch = cpu_generic;
 
@@ -589,7 +598,7 @@ static cpu_support auto_detect_Intel(cpu_info_t const *info)
 	return auto_arch;
 }
 
-static cpu_support auto_detect_AMD(cpu_info_t const *info) {
+static cpu_support auto_detect_AMD(x86_cpu_info_t const *info) {
 	cpu_support auto_arch = cpu_generic;
 
 	unsigned family, model;
@@ -647,12 +656,8 @@ typedef union {
 static void x86_cpuid(cpuid_registers *regs, unsigned level)
 {
 #if defined(__GNUC__)
-	/* 32bit requires ebx to be saved, and it doesn't hurt on 64 bit */
-	__asm ("pushl %%ebx\n\t"
-	       "cpuid\n\t"
-		   "movl  %%ebx, %1\n\t"
-		   "popl  %%ebx\n\t"
-	: "=a" (regs->r.eax), "=r" (regs->r.ebx), "=c" (regs->r.ecx), "=d" (regs->r.edx)
+	__asm ("cpuid\n\t"
+	: "=a" (regs->r.eax), "=b" (regs->r.ebx), "=c" (regs->r.ecx), "=d" (regs->r.edx)
 	: "a" (level)
 	);
 #elif defined(_MSC_VER)
@@ -711,7 +716,7 @@ static void autodetect_arch(void)
 		cpuid_registers   regs;
 		unsigned          highest_level;
 		char              vendorid[13];
-		struct cpu_info_t cpu_info;
+		x86_cpu_info_t    cpu_info;
 
 		/* get vendor ID */
 		x86_cpuid(&regs, 0);