cpuid: Use __asm for MSVC
authorAhmed Samy <f.fallen45@gmail.com>
Fri, 25 Oct 2013 14:02:10 +0000 (16:02 +0200)
committerAhmed Samy <f.fallen45@gmail.com>
Fri, 25 Oct 2013 14:02:10 +0000 (16:02 +0200)
MSVC only supports inline assembly and does not support the keyword
volatile for assembly.

Signed-off-by: Ahmed Samy <f.fallen45@gmail.com>
ccan/cpuid/cpuid.c

index 026875dcae86b3188115b5fc3513e6a78dfbf6ff..57883e2bd0982b17fccdeaf34fd5da945c1134ea 100644 (file)
@@ -92,6 +92,8 @@ static struct {
 
 bool cpuid_is_supported(void)
 {
+       int ret = 0;
+#if defined(__GNUC__) || defined(__clang__)
        /* The following assembly code uses EAX as the return value,
         * but we store the value of EAX into ret since GCC uses EAX
         * as the return register for every C function.  That's a double
@@ -124,7 +126,6 @@ bool cpuid_is_supported(void)
 #define ASM_PUSHECX    "pushl %%ecx\n\t"
 #endif
 
-       int ret = 0;
        asm volatile(
                ASM_PUSHF
                ASM_POPEAX
@@ -147,7 +148,26 @@ bool cpuid_is_supported(void)
 #undef ASM_PUSHEAX
 #undef ASM_POPEAX
 #undef ASM_PUSHECX
-
+#elif defined _MSC_VER
+       __asm {
+               pushfd
+               pop eax
+               mov ecx, eax
+               xor eax, 0x200000
+               push eax
+               popfd
+
+               pushfd
+               pop eax
+               xor eax, ecx
+               shr eax, 0x21
+               and eax, 0x1
+               push ecx
+               popfd
+
+               mov eax, ret
+       };
+#endif
        return !!ret;
 }
 
@@ -235,11 +255,19 @@ uint32_t cpuid_highest_ext_func_supported(void)
        static uint32_t highest;
 
        if (!highest) {
+#if defined(__GNUC__) || defined(__clang__)
                asm volatile(
                        "cpuid\n\t"
                        : "=a" (highest)
                        : "a" (CPU_HIGHEST_EXTENDED_FUNCTION_SUPPORTED)
                );
+#elif defined _MSC_VER
+               __asm {
+                       mov eax, CPU_HIGHEST_EXTENDED_FUNCTION_SUPPORTED
+                       cpuid
+                       mov highest, eax
+               };
+#endif
        }
 
        return highest;