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// Copyright 2017 Google Inc. All Rights Reserved.
//
// Use of this source code is governed by a BSD-style license
// that can be found in the COPYING 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.
// -----------------------------------------------------------------------------
//
// SSE2 version of distortion calculation
//
// Author: Skal (pascal.massimino@gmail.com)
#include "src/dsp/dsp.h"
#if defined(WEBP_USE_SSE2)
#include <assert.h>
#include <emmintrin.h>
#include "src/dsp/common_sse2.h"
#if !defined(WEBP_DISABLE_STATS)
// Helper function
static WEBP_INLINE void SubtractAndSquare_SSE2(const __m128i a, const __m128i b,
__m128i* const sum) {
// take abs(a-b) in 8b
const __m128i a_b = _mm_subs_epu8(a, b);
const __m128i b_a = _mm_subs_epu8(b, a);
const __m128i abs_a_b = _mm_or_si128(a_b, b_a);
// zero-extend to 16b
const __m128i zero = _mm_setzero_si128();
const __m128i C0 = _mm_unpacklo_epi8(abs_a_b, zero);
const __m128i C1 = _mm_unpackhi_epi8(abs_a_b, zero);
// multiply with self
const __m128i sum1 = _mm_madd_epi16(C0, C0);
const __m128i sum2 = _mm_madd_epi16(C1, C1);
*sum = _mm_add_epi32(sum1, sum2);
}
//------------------------------------------------------------------------------
// SSIM / PSNR entry point
static uint32_t AccumulateSSE_SSE2(const uint8_t* src1,
const uint8_t* src2, int len) {
int i = 0;
uint32_t sse2 = 0;
if (len >= 16) {
const int limit = len - 32;
int32_t tmp[4];
__m128i sum1;
__m128i sum = _mm_setzero_si128();
__m128i a0 = _mm_loadu_si128((const __m128i*)&src1[i]);
__m128i b0 = _mm_loadu_si128((const __m128i*)&src2[i]);
i += 16;
while (i <= limit) {
const __m128i a1 = _mm_loadu_si128((const __m128i*)&src1[i]);
const __m128i b1 = _mm_loadu_si128((const __m128i*)&src2[i]);
__m128i sum2;
i += 16;
SubtractAndSquare_SSE2(a0, b0, &sum1);
sum = _mm_add_epi32(sum, sum1);
a0 = _mm_loadu_si128((const __m128i*)&src1[i]);
b0 = _mm_loadu_si128((const __m128i*)&src2[i]);
i += 16;
SubtractAndSquare_SSE2(a1, b1, &sum2);
sum = _mm_add_epi32(sum, sum2);
}
SubtractAndSquare_SSE2(a0, b0, &sum1);
sum = _mm_add_epi32(sum, sum1);
_mm_storeu_si128((__m128i*)tmp, sum);
sse2 += (tmp[3] + tmp[2] + tmp[1] + tmp[0]);
}
for (; i < len; ++i) {
const int32_t diff = src1[i] - src2[i];
sse2 += diff * diff;
}
return sse2;
}
#endif // !defined(WEBP_DISABLE_STATS)
#if !defined(WEBP_REDUCE_SIZE)
static uint32_t HorizontalAdd16b_SSE2(const __m128i* const m) {
uint16_t tmp[8];
const __m128i a = _mm_srli_si128(*m, 8);
const __m128i b = _mm_add_epi16(*m, a);
_mm_storeu_si128((__m128i*)tmp, b);
return (uint32_t)tmp[3] + tmp[2] + tmp[1] + tmp[0];
}
static uint32_t HorizontalAdd32b_SSE2(const __m128i* const m) {
const __m128i a = _mm_srli_si128(*m, 8);
const __m128i b = _mm_add_epi32(*m, a);
const __m128i c = _mm_add_epi32(b, _mm_srli_si128(b, 4));
return (uint32_t)_mm_cvtsi128_si32(c);
}
static const uint16_t kWeight[] = { 1, 2, 3, 4, 3, 2, 1, 0 };
#define ACCUMULATE_ROW(WEIGHT) do { \
/* compute row weight (Wx * Wy) */ \
const __m128i Wy = _mm_set1_epi16((WEIGHT)); \
const __m128i W = _mm_mullo_epi16(Wx, Wy); \
/* process 8 bytes at a time (7 bytes, actually) */ \
const __m128i a0 = _mm_loadl_epi64((const __m128i*)src1); \
const __m128i b0 = _mm_loadl_epi64((const __m128i*)src2); \
/* convert to 16b and multiply by weight */ \
const __m128i a1 = _mm_unpacklo_epi8(a0, zero); \
const __m128i b1 = _mm_unpacklo_epi8(b0, zero); \
const __m128i wa1 = _mm_mullo_epi16(a1, W); \
const __m128i wb1 = _mm_mullo_epi16(b1, W); \
/* accumulate */ \
xm = _mm_add_epi16(xm, wa1); \
ym = _mm_add_epi16(ym, wb1); \
xxm = _mm_add_epi32(xxm, _mm_madd_epi16(a1, wa1)); \
xym = _mm_add_epi32(xym, _mm_madd_epi16(a1, wb1)); \
yym = _mm_add_epi32(yym, _mm_madd_epi16(b1, wb1)); \
src1 += stride1; \
src2 += stride2; \
} while (0)
static double SSIMGet_SSE2(const uint8_t* src1, int stride1,
const uint8_t* src2, int stride2) {
VP8DistoStats stats;
const __m128i zero = _mm_setzero_si128();
__m128i xm = zero, ym = zero; // 16b accums
__m128i xxm = zero, yym = zero, xym = zero; // 32b accum
const __m128i Wx = _mm_loadu_si128((const __m128i*)kWeight);
assert(2 * VP8_SSIM_KERNEL + 1 == 7);
ACCUMULATE_ROW(1);
ACCUMULATE_ROW(2);
ACCUMULATE_ROW(3);
ACCUMULATE_ROW(4);
ACCUMULATE_ROW(3);
ACCUMULATE_ROW(2);
ACCUMULATE_ROW(1);
stats.xm = HorizontalAdd16b_SSE2(&xm);
stats.ym = HorizontalAdd16b_SSE2(&ym);
stats.xxm = HorizontalAdd32b_SSE2(&xxm);
stats.xym = HorizontalAdd32b_SSE2(&xym);
stats.yym = HorizontalAdd32b_SSE2(&yym);
return VP8SSIMFromStats(&stats);
}
#endif // !defined(WEBP_REDUCE_SIZE)
extern void VP8SSIMDspInitSSE2(void);
WEBP_TSAN_IGNORE_FUNCTION void VP8SSIMDspInitSSE2(void) {
#if !defined(WEBP_DISABLE_STATS)
VP8AccumulateSSE = AccumulateSSE_SSE2;
#endif
#if !defined(WEBP_REDUCE_SIZE)
VP8SSIMGet = SSIMGet_SSE2;
#endif
}
#else // !WEBP_USE_SSE2
WEBP_DSP_INIT_STUB(VP8SSIMDspInitSSE2)
#endif // WEBP_USE_SSE2