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/* Cpu detection code, extracted from mmx.h ((c)1997-99 by H. Dietz
and R. Fisher). Converted to C and improved by Gerard Lantau */
#include <stdlib.h>
#include "../dsputil.h"
/* ebx saving is necessary for PIC. gcc seems unable to see it alone */
#define cpuid(index,eax,ebx,ecx,edx)\
__asm __volatile\
("movl %%ebx, %%esi\n\t"\
"cpuid\n\t"\
"xchgl %%ebx, %%esi"\
: "=a" (eax), "=S" (ebx),\
"=c" (ecx), "=d" (edx)\
: "0" (index));
/* Function to test if multimedia instructions are supported... */
int mm_support(void)
{
int rval;
int eax, ebx, ecx, edx;
__asm__ __volatile__ (
/* See if CPUID instruction is supported ... */
/* ... Get copies of EFLAGS into eax and ecx */
"pushf\n\t"
"popl %0\n\t"
"movl %0, %1\n\t"
/* ... Toggle the ID bit in one copy and store */
/* to the EFLAGS reg */
"xorl $0x200000, %0\n\t"
"push %0\n\t"
"popf\n\t"
/* ... Get the (hopefully modified) EFLAGS */
"pushf\n\t"
"popl %0\n\t"
: "=a" (eax), "=c" (ecx)
:
: "cc"
);
if (eax == ecx)
return 0; /* CPUID not supported */
cpuid(0, eax, ebx, ecx, edx);
if (ebx == 0x756e6547 &&
edx == 0x49656e69 &&
ecx == 0x6c65746e) {
/* intel */
inteltest:
cpuid(1, eax, ebx, ecx, edx);
if ((edx & 0x00800000) == 0)
return 0;
rval = MM_MMX;
if (edx & 0x02000000)
rval |= MM_MMXEXT | MM_SSE;
if (edx & 0x04000000)
rval |= MM_SSE2;
return rval;
} else if (ebx == 0x68747541 &&
edx == 0x69746e65 &&
ecx == 0x444d4163) {
/* AMD */
cpuid(0x80000000, eax, ebx, ecx, edx);
if ((unsigned)eax < 0x80000001)
goto inteltest;
cpuid(0x80000001, eax, ebx, ecx, edx);
if ((edx & 0x00800000) == 0)
return 0;
rval = MM_MMX;
if (edx & 0x80000000)
rval |= MM_3DNOW;
if (edx & 0x00400000)
rval |= MM_MMXEXT;
return rval;
} 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)
goto inteltest;
cpuid(0x80000001, eax, ebx, ecx, edx);
if ((eax & 0x00800000) == 0)
return 0;
rval = MM_MMX;
if (eax & 0x01000000)
rval |= MM_MMXEXT;
return rval;
} else {
return 0;
}
}
#ifdef __TEST__
int main ( void )
{
int mm_flags;
mm_flags = mm_support();
printf("mm_support = 0x%08u\n",mm_flags);
return 0;
}
#endif
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