//-------------------------------------------------------------------------------------
// DirectXMathF16C.h -- F16C/CVT16 extensions for SIMD C++ Math library
//
// Copyright (c) Microsoft Corporation. All rights reserved.
// Licensed under the MIT License.
//
// http://go.microsoft.com/fwlink/?LinkID=615560
//-------------------------------------------------------------------------------------

#pragma once

#if defined(_M_ARM) || defined(_M_ARM64) || defined(_M_HYBRID_X86_ARM64) || __arm__ || __aarch64__
#error F16C not supported on ARM platform
#endif

#include <DirectXMath.h>
#include <DirectXPackedVector.h>

namespace DirectX
{

namespace F16C
{

inline bool XMVerifyF16CSupport()
{
    // Should return true for AMD "Piledriver" and Intel "Ivy Bridge" processors
    // with OS support for AVX (Windows 7 Service Pack 1, Windows Server 2008 R2 Service Pack 1, Windows 8, Windows Server 2012)

    // See http://msdn.microsoft.com/en-us/library/hskdteyh.aspx
    int CPUInfo[4] = { -1 };
#if defined(__clang__) || defined(__GNUC__)
    __cpuid(0, CPUInfo[0], CPUInfo[1], CPUInfo[2], CPUInfo[3]);
#else
    __cpuid(CPUInfo, 0);
#endif

    if ( CPUInfo[0] < 1  )
        return false;

#if defined(__clang__) || defined(__GNUC__)
    __cpuid(1, CPUInfo[0], CPUInfo[1], CPUInfo[2], CPUInfo[3]);
#else
    __cpuid(CPUInfo, 1);
#endif

    // We check for F16C, AVX, OSXSAVE, and SSE4.1
    return ( (CPUInfo[2] & 0x38080000 ) == 0x38080000 );
}


//-------------------------------------------------------------------------------------
// Data conversion
//-------------------------------------------------------------------------------------

inline float XMConvertHalfToFloat( PackedVector::HALF Value )
{
    __m128i V1 = _mm_cvtsi32_si128( static_cast<int>(Value) );
    __m128 V2 = _mm_cvtph_ps( V1 );
    return _mm_cvtss_f32( V2 );
}

inline PackedVector::HALF XMConvertFloatToHalf( float Value )
{
    __m128 V1 = _mm_set_ss( Value );
    __m128i V2 = _mm_cvtps_ph( V1, 0 );
    return static_cast<PackedVector::HALF>( _mm_cvtsi128_si32(V2) );
}

inline float* XMConvertHalfToFloatStream
(
    _Out_writes_bytes_(sizeof(float) + OutputStride * (HalfCount - 1)) float* pOutputStream,
    _In_ size_t      OutputStride,
    _In_reads_bytes_(2 + InputStride * (HalfCount - 1)) const PackedVector::HALF* pInputStream,
    _In_ size_t      InputStride,
    _In_ size_t      HalfCount
)
{
    using namespace PackedVector;

    assert(pOutputStream);
    assert(pInputStream);

    assert(InputStride >= sizeof(HALF));
    assert(OutputStride >= sizeof(float));

    auto pHalf = reinterpret_cast<const uint8_t*>(pInputStream);
    auto pFloat = reinterpret_cast<uint8_t*>(pOutputStream);

    size_t i = 0;
    size_t four = HalfCount >> 2;
    if (four > 0)
    {
        if (InputStride == sizeof(HALF))
        {
            if (OutputStride == sizeof(float))
            {
                if ((reinterpret_cast<uintptr_t>(pFloat) & 0xF) == 0)
                {
                    // Packed input, aligned & packed output
                    for (size_t j = 0; j < four; ++j)
                    {
                        __m128i HV = _mm_loadl_epi64(reinterpret_cast<const __m128i*>(pHalf));
                        pHalf += InputStride * 4;

                        __m128 FV = _mm_cvtph_ps(HV);

                        _mm_stream_ps(reinterpret_cast<float*>(pFloat), FV);
                        pFloat += OutputStride * 4;
                        i += 4;
                    }
                }
                else
                {
                    // Packed input, packed output
                    for (size_t j = 0; j < four; ++j)
                    {
                        __m128i HV = _mm_loadl_epi64(reinterpret_cast<const __m128i*>(pHalf));
                        pHalf += InputStride * 4;

                        __m128 FV = _mm_cvtph_ps(HV);

                        _mm_storeu_ps(reinterpret_cast<float*>(pFloat), FV);
                        pFloat += OutputStride * 4;
                        i += 4;
                    }
                }
            }
            else
            {
                // Packed input, scattered output
                for (size_t j = 0; j < four; ++j)
                {
                    __m128i HV = _mm_loadl_epi64(reinterpret_cast<const __m128i*>(pHalf));
                    pHalf += InputStride * 4;

                    __m128 FV = _mm_cvtph_ps(HV);

                    _mm_store_ss(reinterpret_cast<float*>(pFloat), FV);
                    pFloat += OutputStride;
                    *reinterpret_cast<int*>(pFloat) = _mm_extract_ps(FV, 1);
                    pFloat += OutputStride;
                    *reinterpret_cast<int*>(pFloat) = _mm_extract_ps(FV, 2);
                    pFloat += OutputStride;
                    *reinterpret_cast<int*>(pFloat) = _mm_extract_ps(FV, 3);
                    pFloat += OutputStride;
                    i += 4;
                }
            }
        }
        else if (OutputStride == sizeof(float))
        {
            if ((reinterpret_cast<uintptr_t>(pFloat) & 0xF) == 0)
            {
                // Scattered input, aligned & packed output
                for (size_t j = 0; j < four; ++j)
                {
                    uint16_t H1 = *reinterpret_cast<const HALF*>(pHalf);
                    pHalf += InputStride;
                    uint16_t H2 = *reinterpret_cast<const HALF*>(pHalf);
                    pHalf += InputStride;
                    uint16_t H3 = *reinterpret_cast<const HALF*>(pHalf);
                    pHalf += InputStride;
                    uint16_t H4 = *reinterpret_cast<const HALF*>(pHalf);
                    pHalf += InputStride;

                    __m128i HV = _mm_setzero_si128();
                    HV = _mm_insert_epi16(HV, H1, 0);
                    HV = _mm_insert_epi16(HV, H2, 1);
                    HV = _mm_insert_epi16(HV, H3, 2);
                    HV = _mm_insert_epi16(HV, H4, 3);
                    __m128 FV = _mm_cvtph_ps(HV);

                    _mm_stream_ps(reinterpret_cast<float*>(pFloat), FV);
                    pFloat += OutputStride * 4;
                    i += 4;
                }
            }
            else
            {
                // Scattered input, packed output
                for (size_t j = 0; j < four; ++j)
                {
                    uint16_t H1 = *reinterpret_cast<const HALF*>(pHalf);
                    pHalf += InputStride;
                    uint16_t H2 = *reinterpret_cast<const HALF*>(pHalf);
                    pHalf += InputStride;
                    uint16_t H3 = *reinterpret_cast<const HALF*>(pHalf);
                    pHalf += InputStride;
                    uint16_t H4 = *reinterpret_cast<const HALF*>(pHalf);
                    pHalf += InputStride;

                    __m128i HV = _mm_setzero_si128();
                    HV = _mm_insert_epi16(HV, H1, 0);
                    HV = _mm_insert_epi16(HV, H2, 1);
                    HV = _mm_insert_epi16(HV, H3, 2);
                    HV = _mm_insert_epi16(HV, H4, 3);
                    __m128 FV = _mm_cvtph_ps(HV);

                    _mm_storeu_ps(reinterpret_cast<float*>(pFloat), FV);
                    pFloat += OutputStride * 4;
                    i += 4;
                }

            }
        }
        else
        {
            // Scattered input, scattered output
            for (size_t j = 0; j < four; ++j)
            {
                uint16_t H1 = *reinterpret_cast<const HALF*>(pHalf);
                pHalf += InputStride;
                uint16_t H2 = *reinterpret_cast<const HALF*>(pHalf);
                pHalf += InputStride;
                uint16_t H3 = *reinterpret_cast<const HALF*>(pHalf);
                pHalf += InputStride;
                uint16_t H4 = *reinterpret_cast<const HALF*>(pHalf);
                pHalf += InputStride;

                __m128i HV = _mm_setzero_si128();
                HV = _mm_insert_epi16(HV, H1, 0);
                HV = _mm_insert_epi16(HV, H2, 1);
                HV = _mm_insert_epi16(HV, H3, 2);
                HV = _mm_insert_epi16(HV, H4, 3);
                __m128 FV = _mm_cvtph_ps(HV);

                _mm_store_ss(reinterpret_cast<float*>(pFloat), FV);
                pFloat += OutputStride;
                *reinterpret_cast<int*>(pFloat) = _mm_extract_ps(FV, 1);
                pFloat += OutputStride;
                *reinterpret_cast<int*>(pFloat) = _mm_extract_ps(FV, 2);
                pFloat += OutputStride;
                *reinterpret_cast<int*>(pFloat) = _mm_extract_ps(FV, 3);
                pFloat += OutputStride;
                i += 4;
            }
        }
    }

    for (; i < HalfCount; ++i)
    {
        *reinterpret_cast<float*>(pFloat) = XMConvertHalfToFloat(reinterpret_cast<const HALF*>(pHalf)[0]);
        pHalf += InputStride;
        pFloat += OutputStride;
    }

    return pOutputStream;
}


inline PackedVector::HALF* XMConvertFloatToHalfStream
(
    _Out_writes_bytes_(2 + OutputStride * (FloatCount - 1)) PackedVector::HALF* pOutputStream,
    _In_ size_t       OutputStride,
    _In_reads_bytes_(sizeof(float) + InputStride * (FloatCount - 1)) const float* pInputStream,
    _In_ size_t       InputStride,
    _In_ size_t       FloatCount
)
{
    using namespace PackedVector;

    assert(pOutputStream);
    assert(pInputStream);

    assert(InputStride >= sizeof(float));
    assert(OutputStride >= sizeof(HALF));

    auto pFloat = reinterpret_cast<const uint8_t*>(pInputStream);
    auto pHalf = reinterpret_cast<uint8_t*>(pOutputStream);

    size_t i = 0;
    size_t four = FloatCount >> 2;
    if (four > 0)
    {
        if (InputStride == sizeof(float))
        {
            if (OutputStride == sizeof(HALF))
            {
                if ((reinterpret_cast<uintptr_t>(pFloat) & 0xF) == 0)
                {
                    // Aligned and packed input, packed output
                    for (size_t j = 0; j < four; ++j)
                    {
                        __m128 FV = _mm_load_ps(reinterpret_cast<const float*>(pFloat));
                        pFloat += InputStride * 4;

                        __m128i HV = _mm_cvtps_ph(FV, 0);

                        _mm_storel_epi64(reinterpret_cast<__m128i*>(pHalf), HV);
                        pHalf += OutputStride * 4;
                        i += 4;
                    }
                }
                else
                {
                    // Packed input, packed output
                    for (size_t j = 0; j < four; ++j)
                    {
                        __m128 FV = _mm_loadu_ps(reinterpret_cast<const float*>(pFloat));
                        pFloat += InputStride * 4;

                        __m128i HV = _mm_cvtps_ph(FV, 0);

                        _mm_storel_epi64(reinterpret_cast<__m128i*>(pHalf), HV);
                        pHalf += OutputStride * 4;
                        i += 4;
                    }
                }
            }
            else
            {
                if ((reinterpret_cast<uintptr_t>(pFloat) & 0xF) == 0)
                {
                    // Aligned & packed input, scattered output
                    for (size_t j = 0; j < four; ++j)
                    {
                        __m128 FV = _mm_load_ps(reinterpret_cast<const float*>(pFloat));
                        pFloat += InputStride * 4;

                        __m128i HV = _mm_cvtps_ph(FV, 0);

                        *reinterpret_cast<HALF*>(pHalf) = static_cast<HALF>(_mm_extract_epi16(HV, 0));
                        pHalf += OutputStride;
                        *reinterpret_cast<HALF*>(pHalf) = static_cast<HALF>(_mm_extract_epi16(HV, 1));
                        pHalf += OutputStride;
                        *reinterpret_cast<HALF*>(pHalf) = static_cast<HALF>(_mm_extract_epi16(HV, 2));
                        pHalf += OutputStride;
                        *reinterpret_cast<HALF*>(pHalf) = static_cast<HALF>(_mm_extract_epi16(HV, 3));
                        pHalf += OutputStride;
                        i += 4;
                    }
                }
                else
                {
                    // Packed input, scattered output
                    for (size_t j = 0; j < four; ++j)
                    {
                        __m128 FV = _mm_loadu_ps(reinterpret_cast<const float*>(pFloat));
                        pFloat += InputStride * 4;

                        __m128i HV = _mm_cvtps_ph(FV, 0);

                        *reinterpret_cast<HALF*>(pHalf) = static_cast<HALF>(_mm_extract_epi16(HV, 0));
                        pHalf += OutputStride;
                        *reinterpret_cast<HALF*>(pHalf) = static_cast<HALF>(_mm_extract_epi16(HV, 1));
                        pHalf += OutputStride;
                        *reinterpret_cast<HALF*>(pHalf) = static_cast<HALF>(_mm_extract_epi16(HV, 2));
                        pHalf += OutputStride;
                        *reinterpret_cast<HALF*>(pHalf) = static_cast<HALF>(_mm_extract_epi16(HV, 3));
                        pHalf += OutputStride;
                        i += 4;
                    }
                }
            }
        }
        else if (OutputStride == sizeof(HALF))
        {
            // Scattered input, packed output
            for (size_t j = 0; j < four; ++j)
            {
                __m128 FV1 = _mm_load_ss(reinterpret_cast<const float*>(pFloat));
                pFloat += InputStride;

                __m128 FV2 = _mm_broadcast_ss(reinterpret_cast<const float*>(pFloat));
                pFloat += InputStride;

                __m128 FV3 = _mm_broadcast_ss(reinterpret_cast<const float*>(pFloat));
                pFloat += InputStride;

                __m128 FV4 = _mm_broadcast_ss(reinterpret_cast<const float*>(pFloat));
                pFloat += InputStride;

                __m128 FV = _mm_blend_ps(FV1, FV2, 0x2);
                __m128 FT = _mm_blend_ps(FV3, FV4, 0x8);
                FV = _mm_blend_ps(FV, FT, 0xC);

                __m128i HV = _mm_cvtps_ph(FV, 0);

                _mm_storel_epi64(reinterpret_cast<__m128i*>(pHalf), HV);
                pHalf += OutputStride * 4;
                i += 4;
            }
        }
        else
        {
            // Scattered input, scattered output
            for (size_t j = 0; j < four; ++j)
            {
                __m128 FV1 = _mm_load_ss(reinterpret_cast<const float*>(pFloat));
                pFloat += InputStride;

                __m128 FV2 = _mm_broadcast_ss(reinterpret_cast<const float*>(pFloat));
                pFloat += InputStride;

                __m128 FV3 = _mm_broadcast_ss(reinterpret_cast<const float*>(pFloat));
                pFloat += InputStride;

                __m128 FV4 = _mm_broadcast_ss(reinterpret_cast<const float*>(pFloat));
                pFloat += InputStride;

                __m128 FV = _mm_blend_ps(FV1, FV2, 0x2);
                __m128 FT = _mm_blend_ps(FV3, FV4, 0x8);
                FV = _mm_blend_ps(FV, FT, 0xC);

                __m128i HV = _mm_cvtps_ph(FV, 0);

                *reinterpret_cast<HALF*>(pHalf) = static_cast<HALF>(_mm_extract_epi16(HV, 0));
                pHalf += OutputStride;
                *reinterpret_cast<HALF*>(pHalf) = static_cast<HALF>(_mm_extract_epi16(HV, 1));
                pHalf += OutputStride;
                *reinterpret_cast<HALF*>(pHalf) = static_cast<HALF>(_mm_extract_epi16(HV, 2));
                pHalf += OutputStride;
                *reinterpret_cast<HALF*>(pHalf) = static_cast<HALF>(_mm_extract_epi16(HV, 3));
                pHalf += OutputStride;
                i += 4;
            }
        }
    }

    for (; i < FloatCount; ++i)
    {
        *reinterpret_cast<HALF*>(pHalf) = XMConvertFloatToHalf(reinterpret_cast<const float*>(pFloat)[0]);
        pFloat += InputStride;
        pHalf += OutputStride;
    }

    return pOutputStream;
}


//-------------------------------------------------------------------------------------
// Half2
//-------------------------------------------------------------------------------------

inline XMVECTOR XM_CALLCONV XMLoadHalf2( _In_ const PackedVector::XMHALF2* pSource )
{
    assert(pSource);
    __m128 V = _mm_load_ss( reinterpret_cast<const float*>(pSource) );
    return _mm_cvtph_ps( _mm_castps_si128( V ) );
}

inline void XM_CALLCONV XMStoreHalf2( _Out_ PackedVector::XMHALF2* pDestination, _In_ FXMVECTOR V )
{
    assert(pDestination);
    __m128i V1 = _mm_cvtps_ph( V, 0 );
    _mm_store_ss( reinterpret_cast<float*>(pDestination), _mm_castsi128_ps(V1) );
}


//-------------------------------------------------------------------------------------
// Half4
//-------------------------------------------------------------------------------------

inline XMVECTOR XM_CALLCONV XMLoadHalf4( _In_ const PackedVector::XMHALF4* pSource )
{
    assert(pSource);
    __m128i V = _mm_loadl_epi64( reinterpret_cast<const __m128i*>(pSource) );
    return _mm_cvtph_ps( V );
}

inline void XM_CALLCONV XMStoreHalf4( _Out_ PackedVector::XMHALF4* pDestination, _In_ FXMVECTOR V )
{
    assert(pDestination);
    __m128i V1 = _mm_cvtps_ph( V, 0 );
    _mm_storel_epi64( reinterpret_cast<__m128i*>(pDestination), V1 );
}

} // namespace F16C

} // namespace DirectX