reactos/lib/mingw/cpu_features.c

   1 #include <stdbool.h>
   2 #include "cpu_features.h"
   3
   4 /* level 1 edx bits */
   5 #define EDX_CX8 (1 << 8) /* CMPXCHG8B */
   6 #define EDX_CMOV (1 << 15)
   7 #define EDX_MMX (1 << 23)
   8 #define EDX_FXSR (1 << 24) /* FXSAVE and FXRSTOR */
   9 #define EDX_SSE (1 << 25)
  10 #define EDX_SSE2 (1 << 26)
  11
  12 /*  level 1 ecx bits */
  13 #define ECX_SSE3 (1 << 0)
  14 #define ECX_CX16 (1 << 13) /* CMPXCHG16B */
  15
  16 /* extended level 0x80000001 edx bits */
  17 #define EDX_3DNOW (1 << 31)
  18 #define EDX_3DNOWP (1 << 30)
  19 #define EDX_LM (1 << 29) /*LONG MODE */
  20
  21 #define __cpuid(level,a,b,c,d)                                  \
  22   __asm__ __volatile__ ("cpuid;"                                \
  23                         : "=a" (a), "=b" (b), "=c" (c), "=d" (d)\
  24                         : "0" (level))
  25
  26 /* Combine the different cpuid flags into a single bitmap.  */
  27
  28 unsigned int __cpu_features = 0;
  29
  30 void  __cpu_features_init (void)
  31 {
  32 #ifdef __i386__
  33   unsigned int eax, ebx, ecx, edx;
  34   /* Try to change the value of CPUID bit (bit 21) in EFLAGS.
  35      If the bit can be toggled, CPUID is supported.  */
  36   asm volatile ("pushfl; pushfl; popl %0;"
  37                 "movl %0,%1; xorl %2,%0;"
  38                 "pushl %0; popfl; pushfl; popl %0; popfl"
  39                 : "=&r" (eax), "=&r" (ebx)
  40                 : "i" (0x00200000));
  41
  42   if (((eax ^ ebx) & 0x00200000) == 0)
  43     return;
  44
  45   __cpuid (0, eax, ebx, ecx, edx);
  46   if (eax == 0)
  47     return;
  48
  49   __cpuid (1, eax, ebx, ecx, edx);
  50
  51   if (edx & EDX_CX8)
  52      __cpu_features |= _CRT_CMPXCHG8B;
  53   if (edx & EDX_CMOV)
  54      __cpu_features |= _CRT_CMOV;
  55
  56   if (edx & EDX_MMX)
  57      __cpu_features |= _CRT_MMX;
  58   if (edx & EDX_FXSR)
  59      __cpu_features |= _CRT_FXSR;
  60   if (edx & EDX_SSE)
  61      __cpu_features |= _CRT_SSE;
  62   if (edx & EDX_SSE2)
  63      __cpu_features |= _CRT_SSE2;
  64
  65
  66   if (ecx & ECX_SSE3)
  67      __cpu_features |= _CRT_SSE3;
  68   if (ecx & ECX_CX16)
  69      __cpu_features |= _CRT_CMPXCHG16B;
  70
  71   __cpuid (0x80000000, eax, ebx, ecx, edx);
  72   if (eax < 0x80000001)
  73     return;
  74   __cpuid (0x80000001, eax, ebx, ecx, edx);
  75   if (edx & EDX_3DNOW);
  76     __cpu_features |= _CRT_3DNOW;
  77   if (edx & EDX_3DNOWP)
  78     __cpu_features |= _CRT_3DNOWP;
  79 #endif
  80 }
  81
  82 #ifdef TEST
  83
  84 #include <stdio.h>
  85 #define report(feature) \
  86   if ((feature) & __cpu_features) printf( #feature " found\n")
  87
  88 int main()
  89 {
  90   __cpu_features_init();
  91
  92   report(_CRT_CMPXCHG8B);
  93   report(_CRT_CMOV);
  94   report(_CRT_MMX);
  95   report(_CRT_FXSR);
  96   report(_CRT_SSE);
  97   report(_CRT_SSE2);
  98   report(_CRT_SSE3);
  99   report(_CRT_CMPXCHG16B);
 100   report(_CRT_3DNOW);
 101   report(_CRT_3DNOWP);
 102  return 0;
 103 }
 104
 105 #endif