// 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