SwizzleSSSE3.cpp (2219B)
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 <emmintrin.h> 10 #include <tmmintrin.h> 11 12 namespace mozilla::gfx { 13 14 template <bool aSwapRB> 15 void UnpackRowRGB24(const uint8_t* aSrc, uint8_t* aDst, int32_t aLength); 16 17 template <bool aSwapRB> 18 void UnpackRowRGB24_SSSE3(const uint8_t* aSrc, uint8_t* aDst, int32_t aLength) { 19 // Because this implementation will read an additional 4 bytes of data that 20 // is ignored and masked over, we cannot use the accelerated version for the 21 // last 1-5 pixels (3-15 bytes remaining) to guarantee we don't access memory 22 // outside the buffer (we read in 16 byte chunks). 23 if (aLength < 6) { 24 UnpackRowRGB24<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 - 2) & ~3; 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 2-5 remaining pixels. 37 UnpackRowRGB24<aSwapRB>(src, dst, remainder); 38 39 __m128i mask; 40 if (aSwapRB) { 41 mask = _mm_set_epi8(15, 9, 10, 11, 14, 6, 7, 8, 13, 3, 4, 5, 12, 0, 1, 2); 42 } else { 43 mask = _mm_set_epi8(15, 11, 10, 9, 14, 8, 7, 6, 13, 5, 4, 3, 12, 2, 1, 0); 44 } 45 46 __m128i alpha = _mm_set1_epi32(0xFF000000); 47 48 // Process all 4-pixel chunks as one vector. 49 src -= 4 * 3; 50 dst -= 4 * 4; 51 while (src >= aSrc) { 52 __m128i px = _mm_loadu_si128(reinterpret_cast<const __m128i*>(src)); 53 px = _mm_shuffle_epi8(px, mask); 54 px = _mm_or_si128(px, alpha); 55 _mm_storeu_si128(reinterpret_cast<__m128i*>(dst), px); 56 src -= 4 * 3; 57 dst -= 4 * 4; 58 } 59 } 60 61 // Force instantiation of swizzle variants here. 62 template void UnpackRowRGB24_SSSE3<false>(const uint8_t*, uint8_t*, int32_t); 63 template void UnpackRowRGB24_SSSE3<true>(const uint8_t*, uint8_t*, int32_t); 64 65 } // namespace mozilla::gfx