/*
 *  Copyright 2012 The LibYuv Project Authors. All rights reserved.
 *
 *  Use of this source code is governed by a BSD-style license
 *  that can be found in the LICENSE file in the root of the source
 *  tree. An additional intellectual property rights grant can be found
 *  in the file PATENTS. All contributing project authors may
 *  be found in the AUTHORS file in the root of the source tree.
 */

#include "libyuv/basic_types.h"

#include "libyuv/compare_row.h"
#include "libyuv/row.h"

#if defined(_MSC_VER)
#include <intrin.h>  // For __popcnt
#endif

#ifdef __cplusplus
namespace libyuv {
extern "C" {
#endif

// This module is for 32 bit Visual C x86
#if !defined(LIBYUV_DISABLE_X86) && defined(_MSC_VER) && defined(_M_IX86) && \
    (!defined(__clang__) || defined(LIBYUV_ENABLE_ROWWIN))



__declspec(naked) uint32_t


#ifdef HAS_SUMSQUAREERROR_AVX2
// C4752: found Intel(R) Advanced Vector Extensions; consider using /arch:AVX.
#pragma warning(disable : 4752)
__declspec(naked) uint32_t
    SumSquareError_AVX2(const uint8_t* src_a, const uint8_t* src_b, int count) {
  __asm {
    mov        eax, [esp + 4]  // src_a
    mov        edx, [esp + 8]  // src_b
    mov        ecx, [esp + 12]  // count
    vpxor      ymm0, ymm0, ymm0  // sum
    vpxor      ymm5, ymm5, ymm5  // constant 0 for unpck
    sub        edx, eax

  wloop:
    vmovdqu    ymm1, [eax]
    vmovdqu    ymm2, [eax + edx]
    lea        eax,  [eax + 32]
    vpsubusb   ymm3, ymm1, ymm2  // abs difference trick
    vpsubusb   ymm2, ymm2, ymm1
    vpor       ymm1, ymm2, ymm3
    vpunpcklbw ymm2, ymm1, ymm5  // u16.  mutates order.
    vpunpckhbw ymm1, ymm1, ymm5
    vpmaddwd   ymm2, ymm2, ymm2  // square + hadd to u32.
    vpmaddwd   ymm1, ymm1, ymm1
    vpaddd     ymm0, ymm0, ymm1
    vpaddd     ymm0, ymm0, ymm2
    sub        ecx, 32
    jg         wloop

    vpshufd    ymm1, ymm0, 0xee  // 3, 2 + 1, 0 both lanes.
    vpaddd     ymm0, ymm0, ymm1
    vpshufd    ymm1, ymm0, 0x01  // 1 + 0 both lanes.
    vpaddd     ymm0, ymm0, ymm1
    vpermq     ymm1, ymm0, 0x02  // high + low lane.
    vpaddd     ymm0, ymm0, ymm1
    vmovd      eax, xmm0
    vzeroupper
    ret
  }
}
#endif  // HAS_SUMSQUAREERROR_AVX2

uvec32 kHash16x33 = {0x92d9e201, 0, 0, 0};  // 33 ^ 16
uvec32 kHashMul0 = {
    0x0c3525e1,  // 33 ^ 15
    0xa3476dc1,  // 33 ^ 14
    0x3b4039a1,  // 33 ^ 13
    0x4f5f0981,  // 33 ^ 12
};
uvec32 kHashMul1 = {
    0x30f35d61,  // 33 ^ 11
    0x855cb541,  // 33 ^ 10
    0x040a9121,  // 33 ^ 9
    0x747c7101,  // 33 ^ 8
};
uvec32 kHashMul2 = {
    0xec41d4e1,  // 33 ^ 7
    0x4cfa3cc1,  // 33 ^ 6
    0x025528a1,  // 33 ^ 5
    0x00121881,  // 33 ^ 4
};
uvec32 kHashMul3 = {
    0x00008c61,  // 33 ^ 3
    0x00000441,  // 33 ^ 2
    0x00000021,  // 33 ^ 1
    0x00000001,  // 33 ^ 0
};

__declspec(naked) uint32_t


// Visual C 2012 required for AVX2.
#ifdef HAS_HASHDJB2_AVX2
__declspec(naked) uint32_t
    HashDjb2_AVX2(const uint8_t* src, int count, uint32_t seed) {
  __asm {
    mov        eax, [esp + 4]  // src
    mov        ecx, [esp + 8]  // count
    vmovd      xmm0, [esp + 12]  // seed

  wloop:
    vpmovzxbd  xmm3, [eax]  // src[0-3]
    vpmulld    xmm0, xmm0, xmmword ptr kHash16x33  // hash *= 33 ^ 16
    vpmovzxbd  xmm4, [eax + 4]  // src[4-7]
    vpmulld    xmm3, xmm3, xmmword ptr kHashMul0
    vpmovzxbd  xmm2, [eax + 8]  // src[8-11]
    vpmulld    xmm4, xmm4, xmmword ptr kHashMul1
    vpmovzxbd  xmm1, [eax + 12]  // src[12-15]
    vpmulld    xmm2, xmm2, xmmword ptr kHashMul2
    lea        eax, [eax + 16]
    vpmulld    xmm1, xmm1, xmmword ptr kHashMul3
    vpaddd     xmm3, xmm3, xmm4  // add 16 results
    vpaddd     xmm1, xmm1, xmm2
    vpaddd     xmm1, xmm1, xmm3
    vpshufd    xmm2, xmm1, 0x0e  // upper 2 dwords
    vpaddd     xmm1, xmm1,xmm2
    vpshufd    xmm2, xmm1, 0x01
    vpaddd     xmm1, xmm1, xmm2
    vpaddd     xmm0, xmm0, xmm1
    sub        ecx, 16
    jg         wloop

    vmovd      eax, xmm0  // return hash
    vzeroupper
    ret
  }
}
#endif  // HAS_HASHDJB2_AVX2

#endif  // !defined(LIBYUV_DISABLE_X86) && defined(_M_IX86)

#ifdef __cplusplus
}  // extern "C"
}  // namespace libyuv
#endif