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detect whether the operating system can use AVX

This commit is contained in:
Samuel Neves 2017-12-25 12:34:30 +00:00
parent 0d7015f6a6
commit 60ea749837
1 changed files with 18 additions and 1 deletions
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19
src/blake2-dispatch.c
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@ -63,6 +63,18 @@ static inline void cpuid( uint32_t *eax, uint32_t *ebx, uint32_t *ecx, uint32_t
: "=a"( *eax ), "=b"( *ebx ), "=c"( *ecx ), "=d"( *edx ) : "a"( *eax ) );
#endif
}
static inline uint64_t xgetbv(uint32_t xcr)
{
uint32_t a, d;
__asm__ __volatile__(
"xgetbv"
: "=a"(a),"=d"(d)
: "c"(xcr)
);
return ((uint64_t)d << 32) | a;
}
#elif defined(_MSC_VER)
#include <intrin.h>
static inline void cpuid( uint32_t *eax, uint32_t *ebx, uint32_t *ecx, uint32_t *edx )
@ -106,8 +118,13 @@ static inline cpu_feature_t get_cpu_features( void )
if( IsProcessorFeaturePresent(17) ) /* Some environments don't know about PF_XSAVE_ENABLED */
#endif
{
if( 1 & ( ecx >> 28 ) )
/* check for AVX and OSXSAVE bits */
if( 1 & ( ecx >> 28 ) & (ecx >> 27) ) {
#if !defined(WIN32) /* Already checked for this in WIN32 */
if( (xgetbv(0) & 6) == 6 ) /* XCR0 */
#endif
feature = AVX;
}
eax = 0x80000001;