SwizzleAVX2.cpp (3274B)
1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ 2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */ 3 /* This Source Code Form is subject to the terms of the Mozilla Public 4 * License, v. 2.0. If a copy of the MPL was not distributed with this 5 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ 6 7 #include "Swizzle.h" 8 9 #include <immintrin.h> 10 #include <tmmintrin.h> 11 12 namespace mozilla::gfx { 13 14 template <bool aSwapRB> 15 void UnpackRowRGB24_SSSE3(const uint8_t* aSrc, uint8_t* aDst, int32_t aLength); 16 17 template <bool aSwapRB> 18 void UnpackRowRGB24_AVX2(const uint8_t* aSrc, uint8_t* aDst, int32_t aLength) { 19 // Because this implementation will read an additional 8 bytes of data that 20 // is ignored and masked over, we cannot use the accelerated version for the 21 // last 1-10 pixels (3-30 bytes remaining) to guarantee we don't access memory 22 // outside the buffer (we read in 32 byte chunks). 23 if (aLength < 11) { 24 UnpackRowRGB24_SSSE3<aSwapRB>(aSrc, aDst, aLength); 25 return; 26 } 27 28 // Because we are expanding, we can only process the data back to front in 29 // case we are performing this in place. 30 int32_t alignedRow = (aLength - 4) & ~7; 31 int32_t remainder = aLength - alignedRow; 32 33 const uint8_t* src = aSrc + alignedRow * 3; 34 uint8_t* dst = aDst + alignedRow * 4; 35 36 // Handle any 3-10 remaining pixels. 37 UnpackRowRGB24_SSSE3<aSwapRB>(src, dst, remainder); 38 39 // Used to shuffle the two final 32-bit words which we ignore into the last 40 // 32-bit word of each 128-bit lane, such that 41 // RGBR GBRG BRGB RGBR GBRG BRGB RGBR GBRG 42 // BRGB RGBR GBRG BRGB ZZZZ ZZZZ ZZZZ ZZZZ 43 // becomes 44 // RGBR GBRG BRGB RGBR GBRG BRGB ZZZZ ZZZZ 45 // RGBR GBRG BRGB RGBR GBRG BRGB ZZZZ ZZZZ 46 const __m256i discardMask = _mm256_set_epi32(7, 5, 4, 3, 6, 2, 1, 0); 47 48 // Used to shuffle 8-bit words within a 128-bit lane, such that we transform 49 // RGBR GBRG BRGB RGBR GBRG BRGB ZZZZ ZZZZ 50 // into 51 // RGBZ RGBZ RGBZ RGBZ RGBZ RGBZ RGBZ RGBZ 52 // or 53 // BGRZ BGRZ BGRZ BGRZ BGRZ BGRZ BGRZ BGRZ 54 const __m256i colorMask = 55 aSwapRB ? _mm256_set_epi8(15, 9, 10, 11, 14, 6, 7, 8, 13, 3, 4, 5, 12, 0, 56 1, 2, 15, 9, 10, 11, 14, 6, 7, 8, 13, 3, 4, 5, 57 12, 0, 1, 2) 58 : _mm256_set_epi8(15, 11, 10, 9, 14, 8, 7, 6, 13, 5, 4, 3, 12, 2, 59 1, 0, 15, 11, 10, 9, 14, 8, 7, 6, 13, 5, 4, 3, 60 12, 2, 1, 0); 61 62 // Used to transform RGBZ/BGRZ to RGBX/BGRX, or force the alpha opaque. 63 const __m256i alphaMask = _mm256_set1_epi32(0xFF000000); 64 65 // Process all 8-pixel chunks as one vector. 66 src -= 8 * 3; 67 dst -= 8 * 4; 68 while (src >= aSrc) { 69 __m256i px = _mm256_loadu_si256(reinterpret_cast<const __m256i*>(src)); 70 px = _mm256_permutevar8x32_epi32(px, discardMask); 71 px = _mm256_shuffle_epi8(px, colorMask); 72 px = _mm256_or_si256(px, alphaMask); 73 _mm256_storeu_si256(reinterpret_cast<__m256i*>(dst), px); 74 src -= 8 * 3; 75 dst -= 8 * 4; 76 } 77 } 78 79 // Force instantiation of swizzle variants here. 80 template void UnpackRowRGB24_AVX2<false>(const uint8_t*, uint8_t*, int32_t); 81 template void UnpackRowRGB24_AVX2<true>(const uint8_t*, uint8_t*, int32_t); 82 83 } // namespace mozilla::gfx