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 | // Utilities for processing transparent channel, SSE4.1 variant. |
11 | // |
12 | // Author: Skal (pascal.massimino@gmail.com) |
13 | |
14 | #include "src/dsp/dsp.h" |
15 | |
16 | #if defined(WEBP_USE_SSE41) |
17 | |
18 | #include <smmintrin.h> |
19 | |
20 | //------------------------------------------------------------------------------ |
21 | |
22 | static int ExtractAlpha_SSE41(const uint8_t* WEBP_RESTRICT argb, |
23 | int argb_stride, int width, int height, |
24 | uint8_t* WEBP_RESTRICT alpha, int alpha_stride) { |
25 | // alpha_and stores an 'and' operation of all the alpha[] values. The final |
26 | // value is not 0xff if any of the alpha[] is not equal to 0xff. |
27 | uint32_t alpha_and = 0xff; |
28 | int i, j; |
29 | const __m128i all_0xff = _mm_set1_epi32(~0); |
30 | __m128i all_alphas = all_0xff; |
31 | |
32 | // We must be able to access 3 extra bytes after the last written byte |
33 | // 'src[4 * width - 4]', because we don't know if alpha is the first or the |
34 | // last byte of the quadruplet. |
35 | const int limit = (width - 1) & ~15; |
36 | const __m128i kCstAlpha0 = _mm_set_epi8(-1, -1, -1, -1, -1, -1, -1, -1, |
37 | -1, -1, -1, -1, 12, 8, 4, 0); |
38 | const __m128i kCstAlpha1 = _mm_set_epi8(-1, -1, -1, -1, -1, -1, -1, -1, |
39 | 12, 8, 4, 0, -1, -1, -1, -1); |
40 | const __m128i kCstAlpha2 = _mm_set_epi8(-1, -1, -1, -1, 12, 8, 4, 0, |
41 | -1, -1, -1, -1, -1, -1, -1, -1); |
42 | const __m128i kCstAlpha3 = _mm_set_epi8(12, 8, 4, 0, -1, -1, -1, -1, |
43 | -1, -1, -1, -1, -1, -1, -1, -1); |
44 | for (j = 0; j < height; ++j) { |
45 | const __m128i* src = (const __m128i*)argb; |
46 | for (i = 0; i < limit; i += 16) { |
47 | // load 64 argb bytes |
48 | const __m128i a0 = _mm_loadu_si128(src + 0); |
49 | const __m128i a1 = _mm_loadu_si128(src + 1); |
50 | const __m128i a2 = _mm_loadu_si128(src + 2); |
51 | const __m128i a3 = _mm_loadu_si128(src + 3); |
52 | const __m128i b0 = _mm_shuffle_epi8(a0, kCstAlpha0); |
53 | const __m128i b1 = _mm_shuffle_epi8(a1, kCstAlpha1); |
54 | const __m128i b2 = _mm_shuffle_epi8(a2, kCstAlpha2); |
55 | const __m128i b3 = _mm_shuffle_epi8(a3, kCstAlpha3); |
56 | const __m128i c0 = _mm_or_si128(b0, b1); |
57 | const __m128i c1 = _mm_or_si128(b2, b3); |
58 | const __m128i d0 = _mm_or_si128(c0, c1); |
59 | // store |
60 | _mm_storeu_si128((__m128i*)&alpha[i], d0); |
61 | // accumulate sixteen alpha 'and' in parallel |
62 | all_alphas = _mm_and_si128(all_alphas, d0); |
63 | src += 4; |
64 | } |
65 | for (; i < width; ++i) { |
66 | const uint32_t alpha_value = argb[4 * i]; |
67 | alpha[i] = alpha_value; |
68 | alpha_and &= alpha_value; |
69 | } |
70 | argb += argb_stride; |
71 | alpha += alpha_stride; |
72 | } |
73 | // Combine the sixteen alpha 'and' into an 8-bit mask. |
74 | alpha_and |= 0xff00u; // pretend the upper bits [8..15] were tested ok. |
75 | alpha_and &= _mm_movemask_epi8(_mm_cmpeq_epi8(all_alphas, all_0xff)); |
76 | return (alpha_and == 0xffffu); |
77 | } |
78 | |
79 | //------------------------------------------------------------------------------ |
80 | // Entry point |
81 | |
82 | extern void WebPInitAlphaProcessingSSE41(void); |
83 | |
84 | WEBP_TSAN_IGNORE_FUNCTION void WebPInitAlphaProcessingSSE41(void) { |
85 | WebPExtractAlpha = ExtractAlpha_SSE41; |
86 | } |
87 | |
88 | #else // !WEBP_USE_SSE41 |
89 | |
90 | WEBP_DSP_INIT_STUB(WebPInitAlphaProcessingSSE41) |
91 | |
92 | #endif // WEBP_USE_SSE41 |
93 | |