cpu_features.cpp¶

CPU Feature Detection Implementation. More...

Functions¶

	Name
void	query_cpu_features(std::vector< std::string > & feats) Internal Windows Query for CPU features.

Detailed Description¶

CPU Feature Detection Implementation.

Author: Charliechen114514 (chengh1922@mails.jlu.edu.cn)

Version: 0.1

Date: 2026-02-22

Functions Documentation¶

function query_cpu_features¶

void query_cpu_features(
    std::vector< std::string > & feats
)

Internal Windows Query for CPU features.

Parameters:

feats Output parameter to store detected CPU feature names

Return: cf::expected

Internal Linux Query for CPU features.

Source code¶

#include "cpu_features.h"
#include <intrin.h>

namespace {
__attribute__((target("xsave"))) static unsigned long long read_xcr0() {
    return _xgetbv(0);
}
void addFeatureIfSupported(bool condition, const char* name, std::vector<std::string>& feats) {
    if (condition) {
        feats.emplace_back(name);
    }
}

} // namespace

void query_cpu_features(std::vector<std::string>& feats) {
    int cpuInfo[4] = {};

    __cpuid(cpuInfo, 1);

    // SSE / AES / FMA
    addFeatureIfSupported(cpuInfo[2] & (1 << 25), "aes", feats);
    addFeatureIfSupported(cpuInfo[2] & (1 << 12), "fma", feats);

    // AVX 需要 OS 支持
    bool osxsave = cpuInfo[2] & (1 << 27);
    bool avx_support = cpuInfo[2] & (1 << 28);

    if (osxsave && avx_support) {
        unsigned long long xcr = read_xcr0();
        if ((xcr & 0x6) == 0x6)
            feats.emplace_back("avx");
    }

    __cpuidex(cpuInfo, 7, 0);

    addFeatureIfSupported(cpuInfo[1] & (1 << 5), "avx2", feats);
    addFeatureIfSupported(cpuInfo[1] & (1 << 16), "avx512", feats);
    addFeatureIfSupported(cpuInfo[1] & (1 << 29), "sha2", feats);
}

Updated on 2026-03-09 at 10:14:01 +0000