| /* |
| * 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/base/SkVx.h" |
| #include "src/core/SkMSAN.h" |
| |
| // Helpers for blit_row_s32a_opaque(), |
| // then blit_row_s32a_opaque() itself, |
| // then unrelated blit_row_color32() at the bottom. |
| // |
| // To keep Skia resistant to timing attacks, it's important not to branch on pixel data. |
| // In particular, don't be tempted to [v]ptest, pmovmskb, etc. to branch on the source alpha. |
| |
| #if SK_CPU_SSE_LEVEL >= SK_CPU_SSE_LEVEL_SKX |
| #include <immintrin.h> |
| |
| static inline __m512i SkPMSrcOver_SKX(const __m512i& src, const __m512i& dst) { |
| // Detailed explanations in SkPMSrcOver_AVX2 |
| // b = s + (d*(256-srcA)) >> 8 |
| |
| // Shuffle each pixel's srcA to the low byte of each 16-bit half of the pixel. |
| const uint8_t _ = -1; // fills a literal 0 byte. |
| const uint8_t mask[64] = { 3, _,3, _, 7, _,7, _, 11,_,11,_, 15,_,15,_, |
| 19,_,19,_, 23,_,23,_, 27,_,27,_, 31,_,31,_, |
| 35,_,35,_, 39,_,39,_, 43,_,43,_, 47,_,47,_, |
| 51,_,51,_, 55,_,55,_, 59,_,59,_, 63,_,63,_ }; |
| __m512i srcA_x2 = _mm512_shuffle_epi8(src, _mm512_loadu_si512(mask)); |
| __m512i scale_x2 = _mm512_sub_epi16(_mm512_set1_epi16(256), |
| srcA_x2); |
| |
| // Scale red and blue, leaving results in the low byte of each 16-bit lane. |
| __m512i rb = _mm512_and_si512(_mm512_set1_epi32(0x00ff00ff), dst); |
| rb = _mm512_mullo_epi16(rb, scale_x2); |
| rb = _mm512_srli_epi16(rb, 8); |
| |
| // Scale green and alpha, leaving results in the high byte, masking off the low bits. |
| __m512i ga = _mm512_srli_epi16(dst, 8); |
| ga = _mm512_mullo_epi16(ga, scale_x2); |
| ga = _mm512_andnot_si512(_mm512_set1_epi32(0x00ff00ff), ga); |
| |
| return _mm512_adds_epu8(src, _mm512_or_si512(rb, ga)); |
| } |
| #endif |
| |
| #if SK_CPU_SSE_LEVEL >= SK_CPU_SSE_LEVEL_AVX2 |
| #include <immintrin.h> |
| |
| 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_adds_epu8(src, _mm256_or_si256(rb, ga)); |
| } |
| #endif |
| |
| #if SK_CPU_SSE_LEVEL >= SK_CPU_SSE_LEVEL_SSE2 |
| #include <immintrin.h> |
| |
| static inline __m128i SkPMSrcOver_SSE2(const __m128i& src, const __m128i& dst) { |
| __m128i scale = _mm_sub_epi32(_mm_set1_epi32(256), |
| _mm_srli_epi32(src, 24)); |
| __m128i scale_x2 = _mm_or_si128(_mm_slli_epi32(scale, 16), scale); |
| |
| __m128i rb = _mm_and_si128(_mm_set1_epi32(0x00ff00ff), dst); |
| rb = _mm_mullo_epi16(rb, scale_x2); |
| rb = _mm_srli_epi16(rb, 8); |
| |
| __m128i ga = _mm_srli_epi16(dst, 8); |
| ga = _mm_mullo_epi16(ga, scale_x2); |
| ga = _mm_andnot_si128(_mm_set1_epi32(0x00ff00ff), ga); |
| |
| return _mm_adds_epu8(src, _mm_or_si128(rb, ga)); |
| } |
| #endif |
| |
| #if defined(SK_ARM_HAS_NEON) |
| #include <arm_neon.h> |
| |
| // SkMulDiv255Round() applied to each lane. |
| 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)); |
| } |
| |
| static inline uint8x8x4_t SkPMSrcOver_neon8(uint8x8x4_t dst, uint8x8x4_t src) { |
| uint8x8_t nalphas = vmvn_u8(src.val[3]); // 256 - alpha |
| return { |
| vqadd_u8(src.val[0], SkMulDiv255Round_neon8(nalphas, dst.val[0])), |
| vqadd_u8(src.val[1], SkMulDiv255Round_neon8(nalphas, dst.val[1])), |
| vqadd_u8(src.val[2], SkMulDiv255Round_neon8(nalphas, dst.val[2])), |
| vqadd_u8(src.val[3], SkMulDiv255Round_neon8(nalphas, dst.val[3])), |
| }; |
| } |
| |
| // Variant assuming dst and src contain the color components of two consecutive pixels. |
| 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 vqadd_u8(src, SkMulDiv255Round_neon8(nalphas, dst)); |
| } |
| |
| #endif |
| |
| namespace SK_OPTS_NS { |
| |
| /*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); |
| |
| #if SK_CPU_SSE_LEVEL >= SK_CPU_SSE_LEVEL_SKX |
| while (len >= 16) { |
| _mm512_storeu_si512((__m512*)dst, |
| SkPMSrcOver_SKX(_mm512_loadu_si512((const __m512i*)src), |
| _mm512_loadu_si512((const __m512i*)dst))); |
| src += 16; |
| dst += 16; |
| len -= 16; |
| } |
| #endif |
| |
| #if SK_CPU_SSE_LEVEL >= SK_CPU_SSE_LEVEL_AVX2 |
| while (len >= 8) { |
| _mm256_storeu_si256((__m256i*)dst, |
| SkPMSrcOver_AVX2(_mm256_loadu_si256((const __m256i*)src), |
| _mm256_loadu_si256((const __m256i*)dst))); |
| src += 8; |
| dst += 8; |
| len -= 8; |
| } |
| #endif |
| |
| #if SK_CPU_SSE_LEVEL >= SK_CPU_SSE_LEVEL_SSE2 |
| while (len >= 4) { |
| _mm_storeu_si128((__m128i*)dst, SkPMSrcOver_SSE2(_mm_loadu_si128((const __m128i*)src), |
| _mm_loadu_si128((const __m128i*)dst))); |
| src += 4; |
| dst += 4; |
| len -= 4; |
| } |
| #endif |
| |
| #if defined(SK_ARM_HAS_NEON) |
| while (len >= 8) { |
| vst4_u8((uint8_t*)dst, SkPMSrcOver_neon8(vld4_u8((const uint8_t*)dst), |
| vld4_u8((const uint8_t*)src))); |
| src += 8; |
| dst += 8; |
| len -= 8; |
| } |
| |
| while (len >= 2) { |
| vst1_u8((uint8_t*)dst, SkPMSrcOver_neon2(vld1_u8((const uint8_t*)dst), |
| vld1_u8((const uint8_t*)src))); |
| src += 2; |
| dst += 2; |
| len -= 2; |
| } |
| |
| if (len != 0) { |
| uint8x8_t result = SkPMSrcOver_neon2(vcreate_u8((uint64_t)*dst), |
| vcreate_u8((uint64_t)*src)); |
| vst1_lane_u32(dst, vreinterpret_u32_u8(result), 0); |
| } |
| return; |
| #endif |
| |
| while (len --> 0) { |
| *dst = SkPMSrcOver(*src, *dst); |
| src++; |
| dst++; |
| } |
| } |
| |
| // Blend constant color over count src pixels, writing into dst. |
| /*not static*/ |
| 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<U8>(src), |
| a = U8(invA); |
| U16 c = skvx::cast<uint16_t>(skvx::bit_pun<U8>(U32(color))), |
| d = (mull(s,a) + (c << 8) + 128)>>8; |
| return skvx::bit_pun<U32>(skvx::cast<uint8_t>(d)); |
| }; |
| |
| while (count >= N) { |
| kernel(U32::Load(src)).store(dst); |
| src += N; |
| dst += N; |
| count -= N; |
| } |
| while (count --> 0) { |
| *dst++ = kernel(U32{*src++})[0]; |
| } |
| } |
| |
| } // namespace SK_OPTS_NS |
| |
| #endif//SkBlitRow_opts_DEFINED |