//
//  CPUIdent.h
//
//  Adapted from Microsoft's example for using the cpuid intrinsic,
//  found at https://msdn.microsoft.com/en-us/library/hskdteyh.aspx
//
//  Provides acccess to information provided by the CPUID opcode
//
//  TODO: Generalize to work outside of Windows.
//
//  Created by Ryan Huffman on 3/25/16.
//  Copyright 2016 High Fidelity, Inc.
//
//  Distributed under the Apache License, Version 2.0.
//  See the accompanying file LICENSE or http://www.apache.org/licenses/LICENSE-2.0.html
//

#ifndef hifi_CPUIdent_h
#define hifi_CPUIdent_h

#include <QtCore/QtGlobal>

#include <vector>
#include <bitset>
#include <array>
#include <string>

#ifdef Q_OS_WIN

#include <intrin.h>

class CPUIdent
{
    // forward declarations
    class CPUIdent_Internal;

public:
    struct Feature {
        std::string name;
        bool supported;
    };

    static std::vector<Feature> getAllFeatures();

    static std::string Vendor(void) { return CPU_Rep.vendor_; }
    static std::string Brand(void) { return CPU_Rep.brand_; }

    static bool SSE3(void) { return CPU_Rep.f_1_ECX_[0]; }
    static bool PCLMULQDQ(void) { return CPU_Rep.f_1_ECX_[1]; }
    static bool MONITOR(void) { return CPU_Rep.f_1_ECX_[3]; }
    static bool SSSE3(void) { return CPU_Rep.f_1_ECX_[9]; }
    static bool FMA(void) { return CPU_Rep.f_1_ECX_[12]; }
    static bool CMPXCHG16B(void) { return CPU_Rep.f_1_ECX_[13]; }
    static bool SSE41(void) { return CPU_Rep.f_1_ECX_[19]; }
    static bool SSE42(void) { return CPU_Rep.f_1_ECX_[20]; }
    static bool MOVBE(void) { return CPU_Rep.f_1_ECX_[22]; }
    static bool POPCNT(void) { return CPU_Rep.f_1_ECX_[23]; }
    static bool AES(void) { return CPU_Rep.f_1_ECX_[25]; }
    static bool XSAVE(void) { return CPU_Rep.f_1_ECX_[26]; }
    static bool OSXSAVE(void) { return CPU_Rep.f_1_ECX_[27]; }
    static bool AVX(void) { return CPU_Rep.f_1_ECX_[28]; }
    static bool F16C(void) { return CPU_Rep.f_1_ECX_[29]; }
    static bool RDRAND(void) { return CPU_Rep.f_1_ECX_[30]; }

    static bool MSR(void) { return CPU_Rep.f_1_EDX_[5]; }
    static bool CX8(void) { return CPU_Rep.f_1_EDX_[8]; }
    static bool SEP(void) { return CPU_Rep.f_1_EDX_[11]; }
    static bool CMOV(void) { return CPU_Rep.f_1_EDX_[15]; }
    static bool CLFSH(void) { return CPU_Rep.f_1_EDX_[19]; }
    static bool MMX(void) { return CPU_Rep.f_1_EDX_[23]; }
    static bool FXSR(void) { return CPU_Rep.f_1_EDX_[24]; }
    static bool SSE(void) { return CPU_Rep.f_1_EDX_[25]; }
    static bool SSE2(void) { return CPU_Rep.f_1_EDX_[26]; }

    static bool FSGSBASE(void) { return CPU_Rep.f_7_EBX_[0]; }
    static bool BMI1(void) { return CPU_Rep.f_7_EBX_[3]; }
    static bool HLE(void) { return CPU_Rep.isIntel_ && CPU_Rep.f_7_EBX_[4]; }
    static bool AVX2(void) { return CPU_Rep.f_7_EBX_[5]; }
    static bool BMI2(void) { return CPU_Rep.f_7_EBX_[8]; }
    static bool ERMS(void) { return CPU_Rep.f_7_EBX_[9]; }
    static bool INVPCID(void) { return CPU_Rep.f_7_EBX_[10]; }
    static bool RTM(void) { return CPU_Rep.isIntel_ && CPU_Rep.f_7_EBX_[11]; }
    static bool AVX512F(void) { return CPU_Rep.f_7_EBX_[16]; }
    static bool RDSEED(void) { return CPU_Rep.f_7_EBX_[18]; }
    static bool ADX(void) { return CPU_Rep.f_7_EBX_[19]; }
    static bool AVX512PF(void) { return CPU_Rep.f_7_EBX_[26]; }
    static bool AVX512ER(void) { return CPU_Rep.f_7_EBX_[27]; }
    static bool AVX512CD(void) { return CPU_Rep.f_7_EBX_[28]; }
    static bool SHA(void) { return CPU_Rep.f_7_EBX_[29]; }

    static bool PREFETCHWT1(void) { return CPU_Rep.f_7_ECX_[0]; }

    static bool LAHF(void) { return CPU_Rep.f_81_ECX_[0]; }
    static bool LZCNT(void) { return CPU_Rep.isIntel_ && CPU_Rep.f_81_ECX_[5]; }
    static bool ABM(void) { return CPU_Rep.isAMD_ && CPU_Rep.f_81_ECX_[5]; }
    static bool SSE4a(void) { return CPU_Rep.isAMD_ && CPU_Rep.f_81_ECX_[6]; }
    static bool XOP(void) { return CPU_Rep.isAMD_ && CPU_Rep.f_81_ECX_[11]; }
    static bool TBM(void) { return CPU_Rep.isAMD_ && CPU_Rep.f_81_ECX_[21]; }

    static bool SYSCALL(void) { return CPU_Rep.isIntel_ && CPU_Rep.f_81_EDX_[11]; }
    static bool MMXEXT(void) { return CPU_Rep.isAMD_ && CPU_Rep.f_81_EDX_[22]; }
    static bool RDTSCP(void) { return CPU_Rep.isIntel_ && CPU_Rep.f_81_EDX_[27]; }
    static bool _3DNOWEXT(void) { return CPU_Rep.isAMD_ && CPU_Rep.f_81_EDX_[30]; }
    static bool _3DNOW(void) { return CPU_Rep.isAMD_ && CPU_Rep.f_81_EDX_[31]; }

private:
    static const CPUIdent_Internal CPU_Rep;

    class CPUIdent_Internal
    {
    public:
        CPUIdent_Internal()
            : nIds_ { 0 },
            nExIds_ { 0 },
            isIntel_ { false },
            isAMD_ { false },
            f_1_ECX_ { 0 },
            f_1_EDX_ { 0 },
            f_7_EBX_ { 0 },
            f_7_ECX_ { 0 },
            f_81_ECX_ { 0 },
            f_81_EDX_ { 0 },
            data_ {},
            extdata_ {}
        {
            //int cpuInfo[4] = {-1};
            std::array<int, 4> cpui;

            // Calling __cpuid with 0x0 as the function_id argument
            // gets the number of the highest valid function ID.
            __cpuid(cpui.data(), 0);
            nIds_ = cpui[0];

            for (int i = 0; i <= nIds_; ++i) {
                __cpuidex(cpui.data(), i, 0);
                data_.push_back(cpui);
            }

            // Capture vendor string
            char vendor[0x20];
            memset(vendor, 0, sizeof(vendor));
            *reinterpret_cast<int*>(vendor) = data_[0][1];
            *reinterpret_cast<int*>(vendor + 4) = data_[0][3];
            *reinterpret_cast<int*>(vendor + 8) = data_[0][2];
            vendor_ = vendor;
            if (vendor_ == "GenuineIntel") {
                isIntel_ = true;
            } else if (vendor_ == "AuthenticAMD") {
                isAMD_ = true;
            }

            // load bitset with flags for function 0x00000001
            if (nIds_ >= 1) {
                f_1_ECX_ = data_[1][2];
                f_1_EDX_ = data_[1][3];
            }

            // load bitset with flags for function 0x00000007
            if (nIds_ >= 7) {
                f_7_EBX_ = data_[7][1];
                f_7_ECX_ = data_[7][2];
            }

            // Calling __cpuid with 0x80000000 as the function_id argument
            // gets the number of the highest valid extended ID.
            __cpuid(cpui.data(), 0x80000000);
            nExIds_ = cpui[0];

            char brand[0x40];
            memset(brand, 0, sizeof(brand));

            for (int i = 0x80000000; i <= nExIds_; ++i) {
                __cpuidex(cpui.data(), i, 0);
                extdata_.push_back(cpui);
            }

            // load bitset with flags for function 0x80000001
            if (nExIds_ >= 0x80000001) {
                f_81_ECX_ = extdata_[1][2];
                f_81_EDX_ = extdata_[1][3];
            }

            // Interpret CPU brand string if reported
            if (nExIds_ >= 0x80000004) {
                memcpy(brand, extdata_[2].data(), sizeof(cpui));
                memcpy(brand + 16, extdata_[3].data(), sizeof(cpui));
                memcpy(brand + 32, extdata_[4].data(), sizeof(cpui));
                brand_ = brand;
            }
        };

        int nIds_;
        int nExIds_;
        std::string vendor_;
        std::string brand_;
        bool isIntel_;
        bool isAMD_;
        std::bitset<32> f_1_ECX_;
        std::bitset<32> f_1_EDX_;
        std::bitset<32> f_7_EBX_;
        std::bitset<32> f_7_ECX_;
        std::bitset<32> f_81_ECX_;
        std::bitset<32> f_81_EDX_;
        std::vector<std::array<int, 4>> data_;
        std::vector<std::array<int, 4>> extdata_;
    };

};

#endif

#endif // hifi_CPUIdent_h