diff options
Diffstat (limited to 'src/lib/utils/cpuid/cpuid_x86.cpp')
| -rw-r--r-- | src/lib/utils/cpuid/cpuid_x86.cpp | 15 |
1 files changed, 13 insertions, 2 deletions
diff --git a/src/lib/utils/cpuid/cpuid_x86.cpp b/src/lib/utils/cpuid/cpuid_x86.cpp index be6c75a55..5387a801e 100644 --- a/src/lib/utils/cpuid/cpuid_x86.cpp +++ b/src/lib/utils/cpuid/cpuid_x86.cpp @@ -121,6 +121,7 @@ uint64_t CPUID::detect_cpu_features(size_t* cache_line_size) X86_CPUID_SUBLEVEL(7, 0, cpuid); enum x86_CPUID_7_bits : uint64_t { + BMI1 = (1ULL << 3), AVX2 = (1ULL << 5), BMI2 = (1ULL << 8), AVX512F = (1ULL << 16), @@ -132,8 +133,18 @@ uint64_t CPUID::detect_cpu_features(size_t* cache_line_size) if(flags7 & x86_CPUID_7_bits::AVX2) features_detected |= CPUID::CPUID_AVX2_BIT; - if(flags7 & x86_CPUID_7_bits::BMI2) - features_detected |= CPUID::CPUID_BMI2_BIT; + if(flags7 & x86_CPUID_7_bits::BMI1) + { + features_detected |= CPUID::CPUID_BMI1_BIT; + /* + We only set the BMI2 bit if BMI1 is also supported, so BMI2 + code can safely use both extensions. No known processor + implements BMI2 but not BMI1. + */ + if(flags7 & x86_CPUID_7_bits::BMI2) + features_detected |= CPUID::CPUID_BMI2_BIT; + } + if(flags7 & x86_CPUID_7_bits::AVX512F) features_detected |= CPUID::CPUID_AVX512F_BIT; if(flags7 & x86_CPUID_7_bits::RDSEED) |