1// Copyright 2015 Google Inc. All Rights Reserved.
2//
3// Use of this source code is governed by a BSD-style license
4// that can be found in the COPYING file in the root of the source
5// tree. An additional intellectual property rights grant can be found
6// in the file PATENTS. All contributing project authors may
7// be found in the AUTHORS file in the root of the source tree.
8// -----------------------------------------------------------------------------
9//
10// SSE4.1 variant of methods for lossless encoder
11//
12// Author: Skal (pascal.massimino@gmail.com)
13
14#include "./dsp.h"
15
16#if defined(WEBP_USE_SSE41)
17#include <assert.h>
18#include <smmintrin.h>
19#include "./lossless.h"
20
21//------------------------------------------------------------------------------
22// Subtract-Green Transform
23
24static void SubtractGreenFromBlueAndRed(uint32_t* argb_data, int num_pixels) {
25  int i;
26  const __m128i kCstShuffle = _mm_set_epi8(-1, 13, -1, 13, -1, 9, -1, 9,
27                                           -1,  5, -1,  5, -1, 1, -1, 1);
28  for (i = 0; i + 4 <= num_pixels; i += 4) {
29    const __m128i in = _mm_loadu_si128((__m128i*)&argb_data[i]);
30    const __m128i in_0g0g = _mm_shuffle_epi8(in, kCstShuffle);
31    const __m128i out = _mm_sub_epi8(in, in_0g0g);
32    _mm_storeu_si128((__m128i*)&argb_data[i], out);
33  }
34  // fallthrough and finish off with plain-C
35  VP8LSubtractGreenFromBlueAndRed_C(argb_data + i, num_pixels - i);
36}
37
38//------------------------------------------------------------------------------
39// Entry point
40
41extern void VP8LEncDspInitSSE41(void);
42
43WEBP_TSAN_IGNORE_FUNCTION void VP8LEncDspInitSSE41(void) {
44  VP8LSubtractGreenFromBlueAndRed = SubtractGreenFromBlueAndRed;
45}
46
47#else  // !WEBP_USE_SSE41
48
49WEBP_DSP_INIT_STUB(VP8LEncDspInitSSE41)
50
51#endif  // WEBP_USE_SSE41
52