diff --git a/vpx_ports/x86.h b/vpx_ports/x86.h index ae349fb84..7d93710c4 100644 --- a/vpx_ports/x86.h +++ b/vpx_ports/x86.h @@ -152,7 +152,7 @@ static INLINE int x86_simd_caps(void) { unsigned int flags = 0; unsigned int mask = ~0; - unsigned int reg_eax, reg_ebx, reg_ecx, reg_edx; + unsigned int max_cpuid_val, reg_eax, reg_ebx, reg_ecx, reg_edx; char *env; (void)reg_ebx; @@ -168,9 +168,9 @@ x86_simd_caps(void) { mask = strtol(env, NULL, 0); /* Ensure that the CPUID instruction supports extended features */ - cpuid(0, 0, reg_eax, reg_ebx, reg_ecx, reg_edx); + cpuid(0, 0, max_cpuid_val, reg_ebx, reg_ecx, reg_edx); - if (reg_eax < 1) + if (max_cpuid_val < 1) return 0; /* Get the standard feature flags */ @@ -193,10 +193,12 @@ x86_simd_caps(void) { if ((xgetbv() & 0x6) == 0x6) { flags |= HAS_AVX; - /* Get the leaf 7 feature flags. Needed to check for AVX2 support */ - cpuid(7, 0, reg_eax, reg_ebx, reg_ecx, reg_edx); + if (max_cpuid_val >= 7) { + /* Get the leaf 7 feature flags. Needed to check for AVX2 support */ + cpuid(7, 0, reg_eax, reg_ebx, reg_ecx, reg_edx); - if (reg_ebx & BIT(5)) flags |= HAS_AVX2; + if (reg_ebx & BIT(5)) flags |= HAS_AVX2; + } } }