/*
 *  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/row.h"

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

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

#if !defined(LIBYUV_DISABLE_X86) && defined(_M_IX86) && defined(_MSC_VER)

/* Visual Studio 2005 doesn't support __popcnt(). */
#if (_MSC_VER > 1400)
uint32 HammingDistance_SSE42(const uint8* src_a,
                             const uint8* src_b,
                             int count) {
  uint32 diff = 0u;

  int i;
  for (i = 0; i < count - 3; i += 4) {
    uint32 x = *((uint32*)src_a) ^ *((uint32*)src_b);
    src_a += 4;
    src_b += 4;
    diff += __popcnt(x);
  }
  return diff;
}
#endif

#if (_MSC_VER >= 1900)
__declspec(naked)
#else
__declspec(naked) __declspec(align(16))
#endif
uint32 SumSquareError_SSE2(const uint8* src_a, const uint8* src_b, int count) {
  __asm {
    mov        eax, [esp + 4]    // src_a
    mov        edx, [esp + 8]    // src_b
    mov        ecx, [esp + 12]   // count
    pxor       xmm0, xmm0
    pxor       xmm5, xmm5

    align      4
  wloop:
    movdqa     xmm1, [eax]
    lea        eax,  [eax + 16]
    movdqa     xmm2, [edx]
    lea        edx,  [edx + 16]
    sub        ecx, 16
    movdqa     xmm3, xmm1  // abs trick
    psubusb    xmm1, xmm2
    psubusb    xmm2, xmm3
    por        xmm1, xmm2
    movdqa     xmm2, xmm1
    punpcklbw  xmm1, xmm5
    punpckhbw  xmm2, xmm5
    pmaddwd    xmm1, xmm1
    pmaddwd    xmm2, xmm2
    paddd      xmm0, xmm1
    paddd      xmm0, xmm2
    jg         wloop

    pshufd     xmm1, xmm0, 0xee
    paddd      xmm0, xmm1
    pshufd     xmm1, xmm0, 0x01
    paddd      xmm0, xmm1
    movd       eax, xmm0
    ret
  }
}

// Visual C 2012 required for AVX2.
#if _MSC_VER >= 1700
// C4752: found Intel(R) Advanced Vector Extensions; consider using /arch:AVX.
#pragma warning(disable: 4752)
#if (_MSC_VER >= 1900)
__declspec(naked)
#else
__declspec(naked) __declspec(align(16))
#endif
uint32 SumSquareError_AVX2(const uint8* src_a, const uint8* 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

    align      4
  wloop:
    vmovdqu    ymm1, [eax]
    vmovdqu    ymm2, [eax + edx]
    lea        eax,  [eax + 32]
    sub        ecx, 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
    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  // _MSC_VER >= 1700

#define HAS_HASHDJB2_SSE41
static uvec32 kHash16x33 = { 0x92d9e201, 0, 0, 0 };  // 33 ^ 16
static uvec32 kHashMul0 = {
  0x0c3525e1,  // 33 ^ 15
  0xa3476dc1,  // 33 ^ 14
  0x3b4039a1,  // 33 ^ 13
  0x4f5f0981,  // 33 ^ 12
};
static uvec32 kHashMul1 = {
  0x30f35d61,  // 33 ^ 11
  0x855cb541,  // 33 ^ 10
  0x040a9121,  // 33 ^ 9
  0x747c7101,  // 33 ^ 8
};
static uvec32 kHashMul2 = {
  0xec41d4e1,  // 33 ^ 7
  0x4cfa3cc1,  // 33 ^ 6
  0x025528a1,  // 33 ^ 5
  0x00121881,  // 33 ^ 4
};
static uvec32 kHashMul3 = {
  0x00008c61,  // 33 ^ 3
  0x00000441,  // 33 ^ 2
  0x00000021,  // 33 ^ 1
  0x00000001,  // 33 ^ 0
};

// 27: 66 0F 38 40 C6     pmulld      xmm0,xmm6
// 44: 66 0F 38 40 DD     pmulld      xmm3,xmm5
// 59: 66 0F 38 40 E5     pmulld      xmm4,xmm5
// 72: 66 0F 38 40 D5     pmulld      xmm2,xmm5
// 83: 66 0F 38 40 CD     pmulld      xmm1,xmm5
#define pmulld(reg) _asm _emit 0x66 _asm _emit 0x0F _asm _emit 0x38 \
    _asm _emit 0x40 _asm _emit reg

#if (_MSC_VER >= 1900)
__declspec(naked)
#else
__declspec(naked) __declspec(align(16))
#endif
uint32 HashDjb2_SSE41(const uint8* src, int count, uint32 seed) {
  __asm {
    mov        eax, [esp + 4]    // src
    mov        ecx, [esp + 8]    // count
    movd       xmm0, [esp + 12]  // seed

    pxor       xmm7, xmm7        // constant 0 for unpck
    movdqa     xmm6, kHash16x33

    align      4
  wloop:
    movdqu     xmm1, [eax]       // src[0-15]
    lea        eax, [eax + 16]
    pmulld(0xc6)                 // pmulld      xmm0,xmm6  hash *= 33 ^ 16
    movdqa     xmm5, kHashMul0
    movdqa     xmm2, xmm1
    punpcklbw  xmm2, xmm7        // src[0-7]
    movdqa     xmm3, xmm2
    punpcklwd  xmm3, xmm7        // src[0-3]
    pmulld(0xdd)                 // pmulld     xmm3, xmm5
    movdqa     xmm5, kHashMul1
    movdqa     xmm4, xmm2
    punpckhwd  xmm4, xmm7        // src[4-7]
    pmulld(0xe5)                 // pmulld     xmm4, xmm5
    movdqa     xmm5, kHashMul2
    punpckhbw  xmm1, xmm7        // src[8-15]
    movdqa     xmm2, xmm1
    punpcklwd  xmm2, xmm7        // src[8-11]
    pmulld(0xd5)                 // pmulld     xmm2, xmm5
    movdqa     xmm5, kHashMul3
    punpckhwd  xmm1, xmm7        // src[12-15]
    pmulld(0xcd)                 // pmulld     xmm1, xmm5
    paddd      xmm3, xmm4        // add 16 results
    paddd      xmm1, xmm2
    sub        ecx, 16
    paddd      xmm1, xmm3

    pshufd     xmm2, xmm1, 0x0e  // upper 2 dwords
    paddd      xmm1, xmm2
    pshufd     xmm2, xmm1, 0x01
    paddd      xmm1, xmm2
    paddd      xmm0, xmm1
    jg         wloop

    movd       eax, xmm0         // return hash
    ret
  }
}

// Visual C 2012 required for AVX2.
#if _MSC_VER >= 1700
#if (_MSC_VER >= 1900)
__declspec(naked)
#else
__declspec(naked) __declspec(align(16))
#endif
uint32 HashDjb2_AVX2(const uint8* src, int count, uint32 seed) {
  __asm {
    mov        eax, [esp + 4]    // src
    mov        ecx, [esp + 8]    // count
    movd       xmm0, [esp + 12]  // seed
    movdqa     xmm6, kHash16x33

    align      4
  wloop:
    vpmovzxbd  xmm3, dword ptr [eax]  // src[0-3]
    pmulld     xmm0, xmm6  // hash *= 33 ^ 16
    vpmovzxbd  xmm4, dword ptr [eax + 4]  // src[4-7]
    pmulld     xmm3, kHashMul0
    vpmovzxbd  xmm2, dword ptr [eax + 8]  // src[8-11]
    pmulld     xmm4, kHashMul1
    vpmovzxbd  xmm1, dword ptr [eax + 12]  // src[12-15]
    pmulld     xmm2, kHashMul2
    lea        eax, [eax + 16]
    pmulld     xmm1, kHashMul3
    paddd      xmm3, xmm4        // add 16 results
    paddd      xmm1, xmm2
    sub        ecx, 16
    paddd      xmm1, xmm3
    pshufd     xmm2, xmm1, 0x0e  // upper 2 dwords
    paddd      xmm1, xmm2
    pshufd     xmm2, xmm1, 0x01
    paddd      xmm1, xmm2
    paddd      xmm0, xmm1
    jg         wloop

    movd       eax, xmm0         // return hash
    ret
  }
}
#endif  // _MSC_VER >= 1700

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

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