gcc-4.9/gcc/testsuite/gcc.target/i386/avx-os-support.h


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/* Check if the OS supports executing AVX instructions.  */

#define XCR_XFEATURE_ENABLED_MASK	0x0

#define XSTATE_FP	0x1
#define XSTATE_SSE	0x2
#define XSTATE_YMM	0x4

static int
avx_os_support (void)
{
  unsigned int eax, edx;
  unsigned int ecx = XCR_XFEATURE_ENABLED_MASK;

  __asm__ ("xgetbv" : "=a" (eax), "=d" (edx) : "c" (ecx));

  return (eax & (XSTATE_SSE | XSTATE_YMM)) == (XSTATE_SSE | XSTATE_YMM);
}