#include "cpu_features.h"

/* level 1 edx bits */
#define EDX_CX8     (1 << 8)    /* CMPXCHG8B */
#define EDX_CMOV    (1 << 15)
#define EDX_MMX     (1 << 23)
#define EDX_FXSR    (1 << 24)   /* FXSAVE and FXRSTOR */
#define EDX_SSE     (1 << 25)
#define EDX_SSE2    (1 << 26)

/*  level 1 ecx bits */
#define ECX_SSE3    (1 << 0)
#define ECX_CX16    (1 << 13)   /* CMPXCHG16B */

/* extended level 0x80000001 edx bits */
#define EDX_3DNOW   (1 << 31)
#define EDX_3DNOWP  (1 << 30)
#define EDX_LM      (1 << 29)   /*LONG MODE */

#define __cpuid(level,a,b,c,d)			 		\
  __asm__ __volatile__ ("cpuid;"				\
			: "=a" (a), "=b" (b), "=c" (c), "=d" (d)\
			: "0" (level))

/* Combine the different cpuid flags into a single bitmap.  */

unsigned int __cpu_features = 0;

void  __cpu_features_init (void)
{
    unsigned int eax, ebx, ecx, edx;

  __cpuid (0, eax, ebx, ecx, edx);
  if (eax == 0)
    return;

  __cpuid (1, eax, ebx, ecx, edx);

  if (edx & EDX_CX8)
     __cpu_features |= _CRT_CMPXCHG8B;
  if (edx & EDX_CMOV)
     __cpu_features |= _CRT_CMOV;

  if (edx & EDX_MMX)
     __cpu_features |= _CRT_MMX;
  if (edx & EDX_FXSR)
     __cpu_features |= _CRT_FXSR;
  if (edx & EDX_SSE)
     __cpu_features |= _CRT_SSE;
  if (edx & EDX_SSE2)
     __cpu_features |= _CRT_SSE2;


  if (ecx & ECX_SSE3)
     __cpu_features |= _CRT_SSE3;
  if (ecx & ECX_CX16)
     __cpu_features |= _CRT_CMPXCHG16B;

  __cpuid (0x80000000, eax, ebx, ecx, edx);
  if (eax < 0x80000001)
    return;
  __cpuid (0x80000001, eax, ebx, ecx, edx);
  if (edx & EDX_3DNOW)
    __cpu_features |= _CRT_3DNOW;
  if (edx & EDX_3DNOWP)
    __cpu_features |= _CRT_3DNOWP;

  return;
}