| // Copyright 2015 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. |
| // ----------------------------------------------------------------------------- |
| // |
| // Utilities for processing transparent channel, SSE4.1 variant. |
| // |
| // Author: Skal (pascal.massimino@gmail.com) |
| |
| #include "src/dsp/dsp.h" |
| |
| #if defined(WEBP_USE_SSE41) |
| |
| #include <smmintrin.h> |
| |
| //------------------------------------------------------------------------------ |
| |
| static int ExtractAlpha_SSE41(const uint8_t* argb, int argb_stride, |
| int width, int height, |
| uint8_t* alpha, int alpha_stride) { |
| // alpha_and stores an 'and' operation of all the alpha[] values. The final |
| // value is not 0xff if any of the alpha[] is not equal to 0xff. |
| uint32_t alpha_and = 0xff; |
| int i, j; |
| const __m128i all_0xff = _mm_set1_epi32(~0u); |
| __m128i all_alphas = all_0xff; |
| |
| // We must be able to access 3 extra bytes after the last written byte |
| // 'src[4 * width - 4]', because we don't know if alpha is the first or the |
| // last byte of the quadruplet. |
| const int limit = (width - 1) & ~15; |
| const __m128i kCstAlpha0 = _mm_set_epi8(-1, -1, -1, -1, -1, -1, -1, -1, |
| -1, -1, -1, -1, 12, 8, 4, 0); |
| const __m128i kCstAlpha1 = _mm_set_epi8(-1, -1, -1, -1, -1, -1, -1, -1, |
| 12, 8, 4, 0, -1, -1, -1, -1); |
| const __m128i kCstAlpha2 = _mm_set_epi8(-1, -1, -1, -1, 12, 8, 4, 0, |
| -1, -1, -1, -1, -1, -1, -1, -1); |
| const __m128i kCstAlpha3 = _mm_set_epi8(12, 8, 4, 0, -1, -1, -1, -1, |
| -1, -1, -1, -1, -1, -1, -1, -1); |
| for (j = 0; j < height; ++j) { |
| const __m128i* src = (const __m128i*)argb; |
| for (i = 0; i < limit; i += 16) { |
| // load 64 argb bytes |
| const __m128i a0 = _mm_loadu_si128(src + 0); |
| const __m128i a1 = _mm_loadu_si128(src + 1); |
| const __m128i a2 = _mm_loadu_si128(src + 2); |
| const __m128i a3 = _mm_loadu_si128(src + 3); |
| const __m128i b0 = _mm_shuffle_epi8(a0, kCstAlpha0); |
| const __m128i b1 = _mm_shuffle_epi8(a1, kCstAlpha1); |
| const __m128i b2 = _mm_shuffle_epi8(a2, kCstAlpha2); |
| const __m128i b3 = _mm_shuffle_epi8(a3, kCstAlpha3); |
| const __m128i c0 = _mm_or_si128(b0, b1); |
| const __m128i c1 = _mm_or_si128(b2, b3); |
| const __m128i d0 = _mm_or_si128(c0, c1); |
| // store |
| _mm_storeu_si128((__m128i*)&alpha[i], d0); |
| // accumulate sixteen alpha 'and' in parallel |
| all_alphas = _mm_and_si128(all_alphas, d0); |
| src += 4; |
| } |
| for (; i < width; ++i) { |
| const uint32_t alpha_value = argb[4 * i]; |
| alpha[i] = alpha_value; |
| alpha_and &= alpha_value; |
| } |
| argb += argb_stride; |
| alpha += alpha_stride; |
| } |
| // Combine the sixteen alpha 'and' into an 8-bit mask. |
| alpha_and |= 0xff00u; // pretend the upper bits [8..15] were tested ok. |
| alpha_and &= _mm_movemask_epi8(_mm_cmpeq_epi8(all_alphas, all_0xff)); |
| return (alpha_and == 0xffffu); |
| } |
| |
| //------------------------------------------------------------------------------ |
| // Entry point |
| |
| extern void WebPInitAlphaProcessingSSE41(void); |
| |
| WEBP_TSAN_IGNORE_FUNCTION void WebPInitAlphaProcessingSSE41(void) { |
| WebPExtractAlpha = ExtractAlpha_SSE41; |
| } |
| |
| #else // !WEBP_USE_SSE41 |
| |
| WEBP_DSP_INIT_STUB(WebPInitAlphaProcessingSSE41) |
| |
| #endif // WEBP_USE_SSE41 |