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Diffstat (limited to 'media/libwebp/dsp/alpha_processing_sse41.c')
| -rw-r--r-- | media/libwebp/dsp/alpha_processing_sse41.c | 92 |
1 files changed, 92 insertions, 0 deletions
diff --git a/media/libwebp/dsp/alpha_processing_sse41.c b/media/libwebp/dsp/alpha_processing_sse41.c new file mode 100644 index 0000000000..986fde94ed --- /dev/null +++ b/media/libwebp/dsp/alpha_processing_sse41.c @@ -0,0 +1,92 @@ +// 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 "./dsp.h" + +#if defined(WEBP_USE_SSE41) + +#include <smmintrin.h> + +//------------------------------------------------------------------------------ + +static int ExtractAlpha(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; +} + +#else // !WEBP_USE_SSE41 + +WEBP_DSP_INIT_STUB(WebPInitAlphaProcessingSSE41) + +#endif // WEBP_USE_SSE41 |