ffmpeg/libavcodec/i386/cputest.c

132 lines
4.0 KiB
C

/* Cpu detection code, extracted from mmx.h ((c)1997-99 by H. Dietz
and R. Fisher). Converted to C and improved by Fabrice Bellard */
#include <stdlib.h>
#include "../dsputil.h"
#ifdef ARCH_X86_64
# define REG_b "rbx"
# define REG_S "rsi"
#else
# define REG_b "ebx"
# define REG_S "esi"
#endif
/* ebx saving is necessary for PIC. gcc seems unable to see it alone */
#define cpuid(index,eax,ebx,ecx,edx)\
__asm __volatile\
("mov %%"REG_b", %%"REG_S"\n\t"\
"cpuid\n\t"\
"xchg %%"REG_b", %%"REG_S\
: "=a" (eax), "=S" (ebx),\
"=c" (ecx), "=d" (edx)\
: "0" (index));
/* Function to test if multimedia instructions are supported... */
int mm_support(void)
{
int rval = 0;
int eax, ebx, ecx, edx;
int max_std_level, max_ext_level, std_caps=0, ext_caps=0;
long a, c;
__asm__ __volatile__ (
/* See if CPUID instruction is supported ... */
/* ... Get copies of EFLAGS into eax and ecx */
"pushf\n\t"
"pop %0\n\t"
"mov %0, %1\n\t"
/* ... Toggle the ID bit in one copy and store */
/* to the EFLAGS reg */
"xor $0x200000, %0\n\t"
"push %0\n\t"
"popf\n\t"
/* ... Get the (hopefully modified) EFLAGS */
"pushf\n\t"
"pop %0\n\t"
: "=a" (a), "=c" (c)
:
: "cc"
);
if (a == c)
return 0; /* CPUID not supported */
cpuid(0, max_std_level, ebx, ecx, edx);
if(max_std_level >= 1){
cpuid(1, eax, ebx, ecx, std_caps);
if (std_caps & (1<<23))
rval |= MM_MMX;
if (std_caps & (1<<25))
rval |= MM_MMXEXT | MM_SSE;
if (std_caps & (1<<26))
rval |= MM_SSE2;
}
cpuid(0x80000000, max_ext_level, ebx, ecx, edx);
if(max_ext_level >= 0x80000001){
cpuid(0x80000001, eax, ebx, ecx, ext_caps);
if (ext_caps & (1<<31))
rval |= MM_3DNOW;
if (ext_caps & (1<<30))
rval |= MM_3DNOWEXT;
if (ext_caps & (1<<23))
rval |= MM_MMX;
}
cpuid(0, eax, ebx, ecx, edx);
if ( ebx == 0x68747541 &&
edx == 0x69746e65 &&
ecx == 0x444d4163) {
/* AMD */
if(ext_caps & (1<<22))
rval |= MM_MMXEXT;
} else if (ebx == 0x746e6543 &&
edx == 0x48727561 &&
ecx == 0x736c7561) { /* "CentaurHauls" */
/* VIA C3 */
if(ext_caps & (1<<24))
rval |= MM_MMXEXT;
} else if (ebx == 0x69727943 &&
edx == 0x736e4978 &&
ecx == 0x64616574) {
/* Cyrix Section */
/* See if extended CPUID level 80000001 is supported */
/* The value of CPUID/80000001 for the 6x86MX is undefined
according to the Cyrix CPU Detection Guide (Preliminary
Rev. 1.01 table 1), so we'll check the value of eax for
CPUID/0 to see if standard CPUID level 2 is supported.
According to the table, the only CPU which supports level
2 is also the only one which supports extended CPUID levels.
*/
if (eax < 2)
return rval;
if (ext_caps & (1<<24))
rval |= MM_MMXEXT;
}
#if 0
av_log(NULL, AV_LOG_DEBUG, "%s%s%s%s%s%s\n",
(rval&MM_MMX) ? "MMX ":"",
(rval&MM_MMXEXT) ? "MMX2 ":"",
(rval&MM_SSE) ? "SSE ":"",
(rval&MM_SSE2) ? "SSE2 ":"",
(rval&MM_3DNOW) ? "3DNow ":"",
(rval&MM_3DNOWEXT) ? "3DNowExt ":"");
#endif
return rval;
}
#ifdef __TEST__
int main ( void )
{
int mm_flags;
mm_flags = mm_support();
printf("mm_support = 0x%08X\n",mm_flags);
return 0;
}
#endif