1 2 /* intel_init.c - SSE2 optimized filter functions 3 * 4 * Copyright (c) 2018 Cosmin Truta 5 * Copyright (c) 2016-2017 Glenn Randers-Pehrson 6 * Written by Mike Klein and Matt Sarett, Google, Inc. 7 * Derived from arm/arm_init.c 8 * 9 * This code is released under the libpng license. 10 * For conditions of distribution and use, see the disclaimer 11 * and license in png.h 12 */ 13 14 #include "../pngpriv.h" 15 16 #ifdef PNG_READ_SUPPORTED 17 #if PNG_INTEL_SSE_IMPLEMENTATION > 0 18 19 void png_init_filter_functions_sse2(png_structp pp,unsigned int bpp)20png_init_filter_functions_sse2(png_structp pp, unsigned int bpp) 21 { 22 /* The techniques used to implement each of these filters in SSE operate on 23 * one pixel at a time. 24 * So they generally speed up 3bpp images about 3x, 4bpp images about 4x. 25 * They can scale up to 6 and 8 bpp images and down to 2 bpp images, 26 * but they'd not likely have any benefit for 1bpp images. 27 * Most of these can be implemented using only MMX and 64-bit registers, 28 * but they end up a bit slower than using the equally-ubiquitous SSE2. 29 */ 30 png_debug(1, "in png_init_filter_functions_sse2"); 31 if (bpp == 3) 32 { 33 pp->read_filter[PNG_FILTER_VALUE_SUB-1] = png_read_filter_row_sub3_sse2; 34 pp->read_filter[PNG_FILTER_VALUE_AVG-1] = png_read_filter_row_avg3_sse2; 35 pp->read_filter[PNG_FILTER_VALUE_PAETH-1] = 36 png_read_filter_row_paeth3_sse2; 37 } 38 else if (bpp == 4) 39 { 40 pp->read_filter[PNG_FILTER_VALUE_SUB-1] = png_read_filter_row_sub4_sse2; 41 pp->read_filter[PNG_FILTER_VALUE_AVG-1] = png_read_filter_row_avg4_sse2; 42 pp->read_filter[PNG_FILTER_VALUE_PAETH-1] = 43 png_read_filter_row_paeth4_sse2; 44 } 45 46 /* No need optimize PNG_FILTER_VALUE_UP. The compiler should 47 * autovectorize. 48 */ 49 } 50 51 #endif /* PNG_INTEL_SSE_IMPLEMENTATION > 0 */ 52 #endif /* PNG_READ_SUPPORTED */ 53