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d7d950e8bd
The leading blank lines are apparently an artefact of an older source control system. They are not required and they look like accidents, because starting a source file with a blank line is not a regular habit of software developers nowadays. This is a cherry-pick of commit 37cc20add8fb5b83bb5299a26cd3b41e0f776017 from branch 'libpng18'. Signed-off-by: John Bowler <jbowler@acm.org> Signed-off-by: Cosmin Truta <ctruta@gmail.com>
52 lines
1.8 KiB
C
52 lines
1.8 KiB
C
/* intel_init.c - SSE2 optimized filter functions
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*
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* Copyright (c) 2018 Cosmin Truta
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* Copyright (c) 2016-2017 Glenn Randers-Pehrson
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* Written by Mike Klein and Matt Sarett, Google, Inc.
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* Derived from arm/arm_init.c
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*
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* This code is released under the libpng license.
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* For conditions of distribution and use, see the disclaimer
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* and license in png.h
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*/
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#include "../pngpriv.h"
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#ifdef PNG_READ_SUPPORTED
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#if PNG_INTEL_SSE_IMPLEMENTATION > 0
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void
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png_init_filter_functions_sse2(png_structp pp, unsigned int bpp)
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{
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/* The techniques used to implement each of these filters in SSE operate on
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* one pixel at a time.
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* So they generally speed up 3bpp images about 3x, 4bpp images about 4x.
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* They can scale up to 6 and 8 bpp images and down to 2 bpp images,
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* but they'd not likely have any benefit for 1bpp images.
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* Most of these can be implemented using only MMX and 64-bit registers,
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* but they end up a bit slower than using the equally-ubiquitous SSE2.
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*/
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png_debug(1, "in png_init_filter_functions_sse2");
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if (bpp == 3)
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{
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pp->read_filter[PNG_FILTER_VALUE_SUB-1] = png_read_filter_row_sub3_sse2;
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pp->read_filter[PNG_FILTER_VALUE_AVG-1] = png_read_filter_row_avg3_sse2;
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pp->read_filter[PNG_FILTER_VALUE_PAETH-1] =
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png_read_filter_row_paeth3_sse2;
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}
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else if (bpp == 4)
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{
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pp->read_filter[PNG_FILTER_VALUE_SUB-1] = png_read_filter_row_sub4_sse2;
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pp->read_filter[PNG_FILTER_VALUE_AVG-1] = png_read_filter_row_avg4_sse2;
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pp->read_filter[PNG_FILTER_VALUE_PAETH-1] =
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png_read_filter_row_paeth4_sse2;
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}
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/* No need optimize PNG_FILTER_VALUE_UP. The compiler should
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* autovectorize.
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*/
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}
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#endif /* PNG_INTEL_SSE_IMPLEMENTATION > 0 */
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#endif /* PNG_READ_SUPPORTED */
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