cOMS/stdlib/simd/SIMD_Helper.h

/**
 * Jingga
 *
 * @copyright Jingga
 * @license   OMS License 2.0
 * @version   1.0.0
 * @link      https://jingga.app
 */
#ifndef TOS_STDLIB_SIMD_HELPER_H
#define TOS_STDLIB_SIMD_HELPER_H

#include <stdint.h>
#include <immintrin.h>
#include <xmmintrin.h>

#ifdef _MSC_VER
    #include <intrin.h>
#endif

// @todo implement for arm?

inline int max_sse_supported()
{
    #ifdef _MSC_VER
        int cpuInfo[4] = {-1};
        __cpuid(cpuInfo, 1); // CPUID function 1

        uint32_t ecx = cpuInfo[2];
        uint32_t edx = cpuInfo[3];
    #else
        uint32_t eax, ebx, ecx, edx;

        eax = 1; // CPUID function 1
        __asm__ __volatile__("cpuid;"
                             : "=a"(eax), "=b"(ebx), "=c"(ecx), "=d"(edx)
                             : "a"(eax));
    #endif

    bool sse42_supported = (ecx >> 20) & 1;
    if (sse42_supported) {
        return 42;
    }

    bool sse41_supported = (ecx >> 19) & 1;
    if (sse41_supported) {
        return 41;
    }

    bool sse3_supported = (ecx >> 0) & 1;
    if (sse3_supported) {
        return 3;
    }

    bool sse2_supported = (edx >> 26) & 1;
    if (sse2_supported) {
        return 2;
    }

    return 0;
}

inline
int max_avx256_supported()
{
    int max_version = 0;

    #ifdef _MSC_VER
        int cpuInfo[4];
        __cpuid(cpuInfo, 1);

        if ((cpuInfo[2] >> 28) & 1) {
            __cpuid(cpuInfo, 7); // Query extended features

            if ((cpuInfo[1] >> 5) & 1) {
                max_version = 2;
            }
        }
    #else
        unsigned int eax, ebx, ecx, edx;

        __asm__ __volatile__("cpuid"
                             : "=a"(eax), "=b"(ebx), "=c"(ecx), "=d"(edx)
                             : "a"(1));
        if ((ecx >> 28) & 1) {
            eax = 7;
            ecx = 0;
            __asm__ __volatile__("cpuid"
                                 : "=a"(eax), "=b"(ebx), "=c"(ecx), "=d"(edx)
                                 : "a"(eax), "c"(ecx));

            if ((ebx >> 5) & 1) {
                max_version = 2;
            }
        }
    #endif

    return max_version;
}

inline
int max_avx512_supported()
{
    #ifdef _MSC_VER
        int cpuInfo[4];
        __cpuid(cpuInfo, 1);
        int ebx = 0;

        if ((cpuInfo[2] >> 28) & 1) {
            __cpuid(cpuInfo, 7);

            ebx = cpuInfo[1];
        }
    #else
        unsigned int eax, ebx, ecx, edx;

        __asm__ __volatile__("cpuid"
                             : "=a"(eax), "=b"(ebx), "=c"(ecx), "=d"(edx)
                             : "a"(1));
        if ((ecx >> 28) & 1) {
            eax = 7;
            ecx = 0;
            __asm__ __volatile__("cpuid"
                                 : "=a"(eax), "=b"(ebx), "=c"(ecx), "=d"(edx)
                                 : "a"(eax), "c"(ecx));
        }
    #endif

    if ((ebx >> 16) & 1) {
        return 1; // AVX-512F
    }

    if ((ebx >> 17) & 1) {
        return 2; // AVX-512DQ
    }

    if ((ebx >> 21) & 1) {
        return 3; // AVX-512IFMA
    }

    if ((ebx >> 26) & 1) {
        return 4; // AVX-512PF
    }

    if ((ebx >> 27) & 1) {
        return 5; // AVX-512ER
    }

    if ((ebx >> 28) & 1) {
        return 6; // AVX-512CD
    }

    if ((ebx >> 30) & 1) {
        return 7; // AVX-512BW
    }

    if ((ebx >> 31) & 1) {
        return 8; // AVX-512VL
    }

    return 0;
}

/*
const char avx512_versions[8][12] = {
    "AVX-512F",
    "AVX-512DQ",
    "AVX-512IFMA",
    "AVX-512PF",
    "AVX-512ER",
    "AVX-512CD",
    "AVX-512BW",
    "AVX-512VL"
};
*/

#endif