hvirtual/quicktime/libavcodec/i386/cputest.c

   1 /* Cpu detection code, extracted from mmx.h ((c)1997-99 by H. Dietz
   2    and R. Fisher). Converted to C and improved by Fabrice Bellard */
   3
   4 #include <stdlib.h>
   5 #include "../dsputil.h"
   6
   7 /* ebx saving is necessary for PIC. gcc seems unable to see it alone */
   8 #define cpuid(index,eax,ebx,ecx,edx)\
   9     __asm __volatile\
  10         ("movl %%ebx, %%esi\n\t"\
  11          "cpuid\n\t"\
  12          "xchgl %%ebx, %%esi"\
  13          : "=a" (eax), "=S" (ebx),\
  14            "=c" (ecx), "=d" (edx)\
  15          : "0" (index));
  16
  17 /* Function to test if multimedia instructions are supported...  */
  18 int mm_support(void)
  19 {
  20     int rval;
  21     int eax, ebx, ecx, edx;
  22
  23     __asm__ __volatile__ (
  24                           /* See if CPUID instruction is supported ... */
  25                           /* ... Get copies of EFLAGS into eax and ecx */
  26                           "pushf\n\t"
  27                           "popl %0\n\t"
  28                           "movl %0, %1\n\t"
  29
  30                           /* ... Toggle the ID bit in one copy and store */
  31                           /*     to the EFLAGS reg */
  32                           "xorl $0x200000, %0\n\t"
  33                           "push %0\n\t"
  34                           "popf\n\t"
  35
  36                           /* ... Get the (hopefully modified) EFLAGS */
  37                           "pushf\n\t"
  38                           "popl %0\n\t"
  39                           : "=a" (eax), "=c" (ecx)
  40                           :
  41                           : "cc"
  42                           );
  43
  44     if (eax == ecx)
  45         return 0; /* CPUID not supported */
  46
  47     cpuid(0, eax, ebx, ecx, edx);
  48
  49     if (ebx == 0x756e6547 &&
  50         edx == 0x49656e69 &&
  51         ecx == 0x6c65746e) {
  52
  53         /* intel */
  54     inteltest:
  55         cpuid(1, eax, ebx, ecx, edx);
  56         if ((edx & 0x00800000) == 0)
  57             return 0;
  58         rval = MM_MMX;
  59         if (edx & 0x02000000)
  60             rval |= MM_MMXEXT | MM_SSE;
  61         if (edx & 0x04000000)
  62             rval |= MM_SSE2;
  63         return rval;
  64     } else if (ebx == 0x68747541 &&
  65                edx == 0x69746e65 &&
  66                ecx == 0x444d4163) {
  67         /* AMD */
  68         cpuid(0x80000000, eax, ebx, ecx, edx);
  69         if ((unsigned)eax < 0x80000001)
  70             goto inteltest;
  71         cpuid(0x80000001, eax, ebx, ecx, edx);
  72         if ((edx & 0x00800000) == 0)
  73             return 0;
  74         rval = MM_MMX;
  75         if (edx & 0x80000000)
  76             rval |= MM_3DNOW;
  77         if (edx & 0x00400000)
  78             rval |= MM_MMXEXT;
  79         return rval;
  80     } else if (ebx == 0x746e6543 &&
  81                edx == 0x48727561 &&
  82                ecx == 0x736c7561) {  /*  "CentaurHauls" */
  83         /* VIA C3 */
  84         cpuid(0x80000000, eax, ebx, ecx, edx);
  85         if ((unsigned)eax < 0x80000001)
  86             goto inteltest;
  87         cpuid(0x80000001, eax, ebx, ecx, edx);
  88         rval = 0;
  89         if( edx & ( 1 << 31) )
  90           rval |= MM_3DNOW;
  91         if( edx & ( 1 << 23) )
  92           rval |= MM_MMX;
  93         if( edx & ( 1 << 24) )
  94           rval |= MM_MMXEXT;
  95         return rval;
  96     } else if (ebx == 0x69727943 &&
  97                edx == 0x736e4978 &&
  98                ecx == 0x64616574) {
  99         /* Cyrix Section */
 100         /* See if extended CPUID level 80000001 is supported */
 101         /* The value of CPUID/80000001 for the 6x86MX is undefined
 102            according to the Cyrix CPU Detection Guide (Preliminary
 103            Rev. 1.01 table 1), so we'll check the value of eax for
 104            CPUID/0 to see if standard CPUID level 2 is supported.
 105            According to the table, the only CPU which supports level
 106            2 is also the only one which supports extended CPUID levels.
 107         */
 108         if (eax != 2)
 109             goto inteltest;
 110         cpuid(0x80000001, eax, ebx, ecx, edx);
 111         if ((eax & 0x00800000) == 0)
 112             return 0;
 113         rval = MM_MMX;
 114         if (eax & 0x01000000)
 115             rval |= MM_MMXEXT;
 116         return rval;
 117     } else {
 118         return 0;
 119     }
 120 }
 121
 122 #ifdef __TEST__
 123 int main ( void )
 124 {
 125   int mm_flags;
 126   mm_flags = mm_support();
 127   printf("mm_support = 0x%08u\n",mm_flags);
 128   return 0;
 129 }
 130 #endif