/* * Copyright 2015 Google Inc. * * Use of this source code is governed by a BSD-style license that can be * found in the LICENSE file. */ #ifndef SkBlitRow_opts_DEFINED #define SkBlitRow_opts_DEFINED #include "include/private/SkColorData.h" #include "include/private/SkVx.h" #include "src/core/SkMSAN.h" #if SK_CPU_SSE_LEVEL >= SK_CPU_SSE_LEVEL_AVX2 #include static inline __m256i SkPMSrcOver_AVX2(const __m256i& src, const __m256i& dst) { // Abstractly srcover is // b = s + d*(1-srcA) // // In terms of unorm8 bytes, that works out to // b = s + (d*(255-srcA) + 127) / 255 // // But we approximate that to within a bit with // b = s + (d*(255-srcA) + d) / 256 // a.k.a // b = s + (d*(256-srcA)) >> 8 // The bottleneck of this math is the multiply, and we want to do it as // narrowly as possible, here getting inputs into 16-bit lanes and // using 16-bit multiplies. We can do twice as many multiplies at once // as using naive 32-bit multiplies, and on top of that, the 16-bit multiplies // are themselves a couple cycles quicker. Win-win. // We'll get everything in 16-bit lanes for two multiplies, one // handling dst red and blue, the other green and alpha. (They're // conveniently 16-bits apart, you see.) We don't need the individual // src channels beyond alpha until the very end when we do the "s + " // add, and we don't even need to unpack them; the adds cannot overflow. // Shuffle each pixel's srcA to the low byte of each 16-bit half of the pixel. const int _ = -1; // fills a literal 0 byte. __m256i srcA_x2 = _mm256_shuffle_epi8(src, _mm256_setr_epi8(3,_,3,_, 7,_,7,_, 11,_,11,_, 15,_,15,_, 3,_,3,_, 7,_,7,_, 11,_,11,_, 15,_,15,_)); __m256i scale_x2 = _mm256_sub_epi16(_mm256_set1_epi16(256), srcA_x2); // Scale red and blue, leaving results in the low byte of each 16-bit lane. __m256i rb = _mm256_and_si256(_mm256_set1_epi32(0x00ff00ff), dst); rb = _mm256_mullo_epi16(rb, scale_x2); rb = _mm256_srli_epi16 (rb, 8); // Scale green and alpha, leaving results in the high byte, masking off the low bits. __m256i ga = _mm256_srli_epi16(dst, 8); ga = _mm256_mullo_epi16(ga, scale_x2); ga = _mm256_andnot_si256(_mm256_set1_epi32(0x00ff00ff), ga); return _mm256_add_epi32(src, _mm256_or_si256(rb, ga)); } #elif SK_CPU_SSE_LEVEL >= SK_CPU_SSE_LEVEL_SSE2 #include static inline __m128i SkPMSrcOver_SSE2(const __m128i& src, const __m128i& dst) { auto SkAlphaMulQ_SSE2 = [](const __m128i& c, const __m128i& scale) { const __m128i mask = _mm_set1_epi32(0xFF00FF); __m128i s = _mm_or_si128(_mm_slli_epi32(scale, 16), scale); // uint32_t rb = ((c & mask) * scale) >> 8 __m128i rb = _mm_and_si128(mask, c); rb = _mm_mullo_epi16(rb, s); rb = _mm_srli_epi16(rb, 8); // uint32_t ag = ((c >> 8) & mask) * scale __m128i ag = _mm_srli_epi16(c, 8); ag = _mm_mullo_epi16(ag, s); // (rb & mask) | (ag & ~mask) ag = _mm_andnot_si128(mask, ag); return _mm_or_si128(rb, ag); }; return _mm_add_epi32(src, SkAlphaMulQ_SSE2(dst, _mm_sub_epi32(_mm_set1_epi32(256), _mm_srli_epi32(src, 24)))); } #endif namespace SK_OPTS_NS { // Blend constant color over count src pixels, writing into dst. inline void blit_row_color32(SkPMColor* dst, const SkPMColor* src, int count, SkPMColor color) { constexpr int N = 4; // 8, 16 also reasonable choices using U32 = skvx::Vec< N, uint32_t>; using U16 = skvx::Vec<4*N, uint16_t>; using U8 = skvx::Vec<4*N, uint8_t>; auto kernel = [color](U32 src) { unsigned invA = 255 - SkGetPackedA32(color); invA += invA >> 7; SkASSERT(0 < invA && invA < 256); // We handle alpha == 0 or alpha == 255 specially. // (src * invA + (color << 8) + 128) >> 8 // Should all fit in 16 bits. U8 s = skvx::bit_pun(src), a = U8(invA); U16 c = skvx::cast(skvx::bit_pun(U32(color))), d = (mull(s,a) + (c << 8) + 128)>>8; return skvx::bit_pun(skvx::cast(d)); }; while (count >= N) { kernel(U32::Load(src)).store(dst); src += N; dst += N; count -= N; } while (count --> 0) { *dst++ = kernel(U32{*src++})[0]; } } #if defined(SK_ARM_HAS_NEON) // Return a uint8x8_t value, r, computed as r[i] = SkMulDiv255Round(x[i], y[i]), where r[i], x[i], // y[i] are the i-th lanes of the corresponding NEON vectors. static inline uint8x8_t SkMulDiv255Round_neon8(uint8x8_t x, uint8x8_t y) { uint16x8_t prod = vmull_u8(x, y); return vraddhn_u16(prod, vrshrq_n_u16(prod, 8)); } // The implementations of SkPMSrcOver below perform alpha blending consistently with // SkMulDiv255Round. They compute the color components (numbers in the interval [0, 255]) as: // // result_i = src_i + rint(g(src_alpha, dst_i)) // // where g(x, y) = ((255.0 - x) * y) / 255.0 and rint rounds to the nearest integer. // In this variant of SkPMSrcOver each NEON register, dst.val[i], src.val[i], contains the value // of the same color component for 8 consecutive pixels. The result of this function follows the // same convention. static inline uint8x8x4_t SkPMSrcOver_neon8(uint8x8x4_t dst, uint8x8x4_t src) { uint8x8_t nalphas = vmvn_u8(src.val[3]); uint8x8x4_t result; result.val[0] = vadd_u8(src.val[0], SkMulDiv255Round_neon8(nalphas, dst.val[0])); result.val[1] = vadd_u8(src.val[1], SkMulDiv255Round_neon8(nalphas, dst.val[1])); result.val[2] = vadd_u8(src.val[2], SkMulDiv255Round_neon8(nalphas, dst.val[2])); result.val[3] = vadd_u8(src.val[3], SkMulDiv255Round_neon8(nalphas, dst.val[3])); return result; } // In this variant of SkPMSrcOver dst and src contain the color components of two consecutive // pixels. The return value follows the same convention. static inline uint8x8_t SkPMSrcOver_neon2(uint8x8_t dst, uint8x8_t src) { const uint8x8_t alpha_indices = vcreate_u8(0x0707070703030303); uint8x8_t nalphas = vmvn_u8(vtbl1_u8(src, alpha_indices)); return vadd_u8(src, SkMulDiv255Round_neon8(nalphas, dst)); } #endif /*not static*/ inline void blit_row_s32a_opaque(SkPMColor* dst, const SkPMColor* src, int len, U8CPU alpha) { SkASSERT(alpha == 0xFF); sk_msan_assert_initialized(src, src+len); // Require AVX2 because of AVX2 integer calculation intrinsics in SrcOver #if SK_CPU_SSE_LEVEL >= SK_CPU_SSE_LEVEL_AVX2 while (len >= 32) { // Load 32 source pixels. auto s0 = _mm256_loadu_si256((const __m256i*)(src) + 0), s1 = _mm256_loadu_si256((const __m256i*)(src) + 1), s2 = _mm256_loadu_si256((const __m256i*)(src) + 2), s3 = _mm256_loadu_si256((const __m256i*)(src) + 3); const auto alphaMask = _mm256_set1_epi32(0xFF000000); auto ORed = _mm256_or_si256(s3, _mm256_or_si256(s2, _mm256_or_si256(s1, s0))); if (_mm256_testz_si256(ORed, alphaMask)) { // All 32 source pixels are transparent. Nothing to do. src += 32; dst += 32; len -= 32; continue; } auto d0 = (__m256i*)(dst) + 0, d1 = (__m256i*)(dst) + 1, d2 = (__m256i*)(dst) + 2, d3 = (__m256i*)(dst) + 3; auto ANDed = _mm256_and_si256(s3, _mm256_and_si256(s2, _mm256_and_si256(s1, s0))); if (_mm256_testc_si256(ANDed, alphaMask)) { // All 32 source pixels are opaque. SrcOver becomes Src. _mm256_storeu_si256(d0, s0); _mm256_storeu_si256(d1, s1); _mm256_storeu_si256(d2, s2); _mm256_storeu_si256(d3, s3); src += 32; dst += 32; len -= 32; continue; } // TODO: This math is wrong. // Do SrcOver. _mm256_storeu_si256(d0, SkPMSrcOver_AVX2(s0, _mm256_loadu_si256(d0))); _mm256_storeu_si256(d1, SkPMSrcOver_AVX2(s1, _mm256_loadu_si256(d1))); _mm256_storeu_si256(d2, SkPMSrcOver_AVX2(s2, _mm256_loadu_si256(d2))); _mm256_storeu_si256(d3, SkPMSrcOver_AVX2(s3, _mm256_loadu_si256(d3))); src += 32; dst += 32; len -= 32; } #elif SK_CPU_SSE_LEVEL >= SK_CPU_SSE_LEVEL_SSE41 while (len >= 16) { // Load 16 source pixels. auto s0 = _mm_loadu_si128((const __m128i*)(src) + 0), s1 = _mm_loadu_si128((const __m128i*)(src) + 1), s2 = _mm_loadu_si128((const __m128i*)(src) + 2), s3 = _mm_loadu_si128((const __m128i*)(src) + 3); const auto alphaMask = _mm_set1_epi32(0xFF000000); auto ORed = _mm_or_si128(s3, _mm_or_si128(s2, _mm_or_si128(s1, s0))); if (_mm_testz_si128(ORed, alphaMask)) { // All 16 source pixels are transparent. Nothing to do. src += 16; dst += 16; len -= 16; continue; } auto d0 = (__m128i*)(dst) + 0, d1 = (__m128i*)(dst) + 1, d2 = (__m128i*)(dst) + 2, d3 = (__m128i*)(dst) + 3; auto ANDed = _mm_and_si128(s3, _mm_and_si128(s2, _mm_and_si128(s1, s0))); if (_mm_testc_si128(ANDed, alphaMask)) { // All 16 source pixels are opaque. SrcOver becomes Src. _mm_storeu_si128(d0, s0); _mm_storeu_si128(d1, s1); _mm_storeu_si128(d2, s2); _mm_storeu_si128(d3, s3); src += 16; dst += 16; len -= 16; continue; } // TODO: This math is wrong. // Do SrcOver. _mm_storeu_si128(d0, SkPMSrcOver_SSE2(s0, _mm_loadu_si128(d0))); _mm_storeu_si128(d1, SkPMSrcOver_SSE2(s1, _mm_loadu_si128(d1))); _mm_storeu_si128(d2, SkPMSrcOver_SSE2(s2, _mm_loadu_si128(d2))); _mm_storeu_si128(d3, SkPMSrcOver_SSE2(s3, _mm_loadu_si128(d3))); src += 16; dst += 16; len -= 16; } #elif SK_CPU_SSE_LEVEL >= SK_CPU_SSE_LEVEL_SSE2 while (len >= 16) { // Load 16 source pixels. auto s0 = _mm_loadu_si128((const __m128i*)(src) + 0), s1 = _mm_loadu_si128((const __m128i*)(src) + 1), s2 = _mm_loadu_si128((const __m128i*)(src) + 2), s3 = _mm_loadu_si128((const __m128i*)(src) + 3); const auto alphaMask = _mm_set1_epi32(0xFF000000); auto ORed = _mm_or_si128(s3, _mm_or_si128(s2, _mm_or_si128(s1, s0))); if (0xffff == _mm_movemask_epi8(_mm_cmpeq_epi8(_mm_and_si128(ORed, alphaMask), _mm_setzero_si128()))) { // All 16 source pixels are transparent. Nothing to do. src += 16; dst += 16; len -= 16; continue; } auto d0 = (__m128i*)(dst) + 0, d1 = (__m128i*)(dst) + 1, d2 = (__m128i*)(dst) + 2, d3 = (__m128i*)(dst) + 3; auto ANDed = _mm_and_si128(s3, _mm_and_si128(s2, _mm_and_si128(s1, s0))); if (0xffff == _mm_movemask_epi8(_mm_cmpeq_epi8(_mm_and_si128(ANDed, alphaMask), alphaMask))) { // All 16 source pixels are opaque. SrcOver becomes Src. _mm_storeu_si128(d0, s0); _mm_storeu_si128(d1, s1); _mm_storeu_si128(d2, s2); _mm_storeu_si128(d3, s3); src += 16; dst += 16; len -= 16; continue; } // TODO: This math is wrong. // Do SrcOver. _mm_storeu_si128(d0, SkPMSrcOver_SSE2(s0, _mm_loadu_si128(d0))); _mm_storeu_si128(d1, SkPMSrcOver_SSE2(s1, _mm_loadu_si128(d1))); _mm_storeu_si128(d2, SkPMSrcOver_SSE2(s2, _mm_loadu_si128(d2))); _mm_storeu_si128(d3, SkPMSrcOver_SSE2(s3, _mm_loadu_si128(d3))); src += 16; dst += 16; len -= 16; } #elif defined(SK_ARM_HAS_NEON) // Do 8-pixels at a time. A 16-pixels at a time version of this code was also tested, but it // underperformed on some of the platforms under test for inputs with frequent transitions of // alpha (corresponding to changes of the conditions [~]alpha_u64 == 0 below). It may be worth // revisiting the situation in the future. while (len >= 8) { // Load 8 pixels in 4 NEON registers. src_col.val[i] will contain the same color component // for 8 consecutive pixels (e.g. src_col.val[3] will contain all alpha components of 8 // pixels). uint8x8x4_t src_col = vld4_u8(reinterpret_cast(src)); src += 8; len -= 8; // We now detect 2 special cases: the first occurs when all alphas are zero (the 8 pixels // are all transparent), the second when all alphas are fully set (they are all opaque). uint8x8_t alphas = src_col.val[3]; uint64_t alphas_u64 = vget_lane_u64(vreinterpret_u64_u8(alphas), 0); if (alphas_u64 == 0) { // All pixels transparent. dst += 8; continue; } if (~alphas_u64 == 0) { // All pixels opaque. vst4_u8(reinterpret_cast(dst), src_col); dst += 8; continue; } uint8x8x4_t dst_col = vld4_u8(reinterpret_cast(dst)); vst4_u8(reinterpret_cast(dst), SkPMSrcOver_neon8(dst_col, src_col)); dst += 8; } // Deal with leftover pixels. for (; len >= 2; len -= 2, src += 2, dst += 2) { uint8x8_t src2 = vld1_u8(reinterpret_cast(src)); uint8x8_t dst2 = vld1_u8(reinterpret_cast(dst)); vst1_u8(reinterpret_cast(dst), SkPMSrcOver_neon2(dst2, src2)); } if (len != 0) { uint8x8_t result = SkPMSrcOver_neon2(vcreate_u8(*dst), vcreate_u8(*src)); vst1_lane_u32(dst, vreinterpret_u32_u8(result), 0); } return; #endif while (len-- > 0) { // This 0xFF000000 is not semantically necessary, but for compatibility // with chromium:611002 we need to keep it until we figure out where // the non-premultiplied src values (like 0x00FFFFFF) are coming from. // TODO(mtklein): sort this out and assert *src is premul here. if (*src & 0xFF000000) { *dst = (*src >= 0xFF000000) ? *src : SkPMSrcOver(*src, *dst); } src++; dst++; } } } // SK_OPTS_NS #endif//SkBlitRow_opts_DEFINED