diff options
Diffstat (limited to 'third_party/libpng16/contrib')
| -rw-r--r-- | third_party/libpng16/contrib/intel/INSTALL | 158 | ||||
| -rw-r--r-- | third_party/libpng16/contrib/intel/filter_sse2_intrinsics.c | 379 | ||||
| -rw-r--r-- | third_party/libpng16/contrib/intel/intel_init.c | 54 | ||||
| -rw-r--r-- | third_party/libpng16/contrib/intel/intel_sse.patch | 164 |
4 files changed, 755 insertions, 0 deletions
diff --git a/third_party/libpng16/contrib/intel/INSTALL b/third_party/libpng16/contrib/intel/INSTALL new file mode 100644 index 0000000000..cd5cdd94eb --- /dev/null +++ b/third_party/libpng16/contrib/intel/INSTALL @@ -0,0 +1,158 @@ +Enabling SSE support + +Copyright (c) 2016 Google, Inc. +Written by Mike Klein, Matt Sarett + +This INSTALL file written by Glenn Randers-Pehrson, 2016. + +If you have moved intel_init.c and filter_sse2_intrinsics.c to a different +directory, be sure to update the '#include "../../pngpriv.h"' line in both +files if necessary to point to the correct relative location of pngpriv.h +with respect to the new location of those files. + +To enable SSE support in libpng, follow the instructions in I, II, or III, +below: + +I. Using patched "configure" scripts: + +First, apply intel_sse.patch in your build directory. + + patch -i contrib/intel/intel_sse.patch -p1 + +Then, if you are not building in a new GIT clone, e.g., in a tar +distribution, remove any existing pre-built configure scripts: + + ./configure --enable-maintainer-mode + make maintainer-clean + ./autogen.sh --maintainer --clean + +Finally, configure libpng with -DPNG_INTEL_SSE in CPPFLAGS: + + ./autogen.sh --maintainer + CPPFLAGS="-DPNG_INTEL_SSE" ./configure [options] + make CPPFLAGS="-DPNG_INTEL_SSE" [options] + make + +II. Using a custom makefile: + +If you are using a custom makefile makefile, you will have to update it +manually to include contrib/intel/*.o in the dependencies, and to define +PNG_INTEL_SSE. + +III. Using manually updated "configure" scripts: + +If you prefer, manually edit pngpriv.h, configure.ac, and Makefile.am, +following the instructions below, then follow the instructions in +section II of INSTALL in the main libpng directory, then configure libpng +with -DPNG_INTEL_SSE in CPPFLAGS. + +1. Add the following code to configure.ac under HOST SPECIFIC OPTIONS +directly beneath the section for ARM: + +-----------------cut---------------- +# INTEL +# ===== +# +# INTEL SSE (SIMD) support. + +AC_ARG_ENABLE([intel-sse], + AS_HELP_STRING([[[--enable-intel-sse]]], + [Enable Intel SSE optimizations: =no/off, yes/on:] + [no/off: disable the optimizations;] + [yes/on: enable the optimizations.] + [If not specified: determined by the compiler.]), + [case "$enableval" in + no|off) + # disable the default enabling: + AC_DEFINE([PNG_INTEL_SSE_OPT], [0], + [Disable Intel SSE optimizations]) + # Prevent inclusion of the assembler files below: + enable_intel_sse=no;; + yes|on) + AC_DEFINE([PNG_INTEL_SSE_OPT], [1], + [Enable Intel SSE optimizations]);; + *) + AC_MSG_ERROR([--enable-intel-sse=${enable_intel_sse}: invalid value]) + esac]) + +# Add Intel specific files to all builds where the host_cpu is Intel ('x86*') +# or where Intel optimizations were explicitly requested (this allows a +# fallback if a future host CPU does not match 'x86*') +AM_CONDITIONAL([PNG_INTEL_SSE], + [test "$enable_intel_sse" != 'no' && + case "$host_cpu" in + i?86|x86_64) :;; + *) test "$enable_intel_sse" != '';; + esac]) +-----------------cut---------------- + +2. Add the following code to Makefile.am under HOST SPECIFIC OPTIONS +directly beneath the "if PNG_ARM_NEON ... endif" statement: + +-----------------cut---------------- +if PNG_INTEL_SSE +libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_SOURCES += contrib/intel/intel_init.c\ + contrib/intel/filter_sse2_intrinsics.c +endif +-----------------cut---------------- + +3. Add the following lines to pngpriv.h, following the PNG_ARM_NEON_OPT +code: + +-----------------cut---------------- +#ifndef PNG_INTEL_SSE_OPT +# ifdef PNG_INTEL_SSE + /* Only check for SSE if the build configuration has been modified to + * enable SSE optimizations. This means that these optimizations will + * be off by default. See contrib/intel for more details. + */ +# if defined(__SSE4_1__) || defined(__AVX__) || defined(__SSSE3__) || \ + defined(__SSE2__) || defined(_M_X64) || defined(_M_AMD64) || \ + (defined(_M_IX86_FP) && _M_IX86_FP >= 2) +# define PNG_INTEL_SSE_OPT 1 +# endif +# endif +#endif + +#if PNG_INTEL_SSE_OPT > 0 +# ifndef PNG_INTEL_SSE_IMPLEMENTATION +# if defined(__SSE4_1__) || defined(__AVX__) + /* We are not actually using AVX, but checking for AVX is the best + way we can detect SSE4.1 and SSSE3 on MSVC. + */ +# define PNG_INTEL_SSE_IMPLEMENTATION 3 +# elif defined(__SSSE3__) +# define PNG_INTEL_SSE_IMPLEMENTATION 2 +# elif defined(__SSE2__) || defined(_M_X64) || defined(_M_AMD64) || \ + (defined(_M_IX86_FP) && _M_IX86_FP >= 2) +# define PNG_INTEL_SSE_IMPLEMENTATION 1 +# else +# define PNG_INTEL_SSE_IMPLEMENTATION 0 +# endif +# endif + +# if PNG_INTEL_SSE_IMPLEMENTATION > 0 +# define PNG_FILTER_OPTIMIZATIONS png_init_filter_functions_sse2 +# endif +#endif + +-----------------cut---------------- + +4. Add the following lines to pngpriv.h, following the prototype for +png_read_filter_row_paeth4_neon: + +-----------------cut---------------- +PNG_INTERNAL_FUNCTION(void,png_read_filter_row_sub3_sse2,(png_row_infop + row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY); +PNG_INTERNAL_FUNCTION(void,png_read_filter_row_sub4_sse2,(png_row_infop + row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY); +PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg3_sse2,(png_row_infop + row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY); +PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg4_sse2,(png_row_infop + row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY); +PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth3_sse2,(png_row_infop + row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY); +PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth4_sse2,(png_row_infop + row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY); + +-----------------cut---------------- diff --git a/third_party/libpng16/contrib/intel/filter_sse2_intrinsics.c b/third_party/libpng16/contrib/intel/filter_sse2_intrinsics.c new file mode 100644 index 0000000000..aea3f86af5 --- /dev/null +++ b/third_party/libpng16/contrib/intel/filter_sse2_intrinsics.c @@ -0,0 +1,379 @@ + +/* filter_sse2_intrinsics.c - SSE2 optimized filter functions + * + * Copyright (c) 2016 Google, Inc. + * Written by Mike Klein and Matt Sarett + * Derived from arm/filter_neon_intrinsics.c, which was + * Copyright (c) 2014,2016 Glenn Randers-Pehrson + * + * Last changed in libpng 1.6.22 [May 26, 2016] + * + * This code is released under the libpng license. + * For conditions of distribution and use, see the disclaimer + * and license in png.h + */ + +#include "../../pngpriv.h" + +#ifdef PNG_READ_SUPPORTED + +#if PNG_INTEL_SSE_IMPLEMENTATION > 0 + +#include <immintrin.h> + +/* Functions in this file look at most 3 pixels (a,b,c) to predict the 4th (d). + * They're positioned like this: + * prev: c b + * row: a d + * The Sub filter predicts d=a, Avg d=(a+b)/2, and Paeth predicts d to be + * whichever of a, b, or c is closest to p=a+b-c. + */ + +static __m128i load4(const void* p) { + return _mm_cvtsi32_si128(*(const int*)p); +} + +static void store4(void* p, __m128i v) { + *(int*)p = _mm_cvtsi128_si32(v); +} + +static __m128i load3(const void* p) { + /* We'll load 2 bytes, then 1 byte, + * then mask them together, and finally load into SSE. + */ + const png_uint_16* p01 = p; + const png_byte* p2 = (const png_byte*)(p01+1); + + png_uint_32 v012 = (png_uint_32)(*p01) + | (png_uint_32)(*p2) << 16; + return load4(&v012); +} + +static void store3(void* p, __m128i v) { + /* We'll pull from SSE as a 32-bit int, then write + * its bottom two bytes, then its third byte. + */ + png_uint_32 v012; + store4(&v012, v); + + png_uint_16* p01 = p; + png_byte* p2 = (png_byte*)(p01+1); + *p01 = v012; + *p2 = v012 >> 16; +} + +void png_read_filter_row_sub3_sse2(png_row_infop row_info, png_bytep row, + png_const_bytep prev) +{ + /* The Sub filter predicts each pixel as the previous pixel, a. + * There is no pixel to the left of the first pixel. It's encoded directly. + * That works with our main loop if we just say that left pixel was zero. + */ + png_debug(1, "in png_read_filter_row_sub3_sse2"); + __m128i a, d = _mm_setzero_si128(); + + int rb = row_info->rowbytes; + while (rb >= 4) { + a = d; d = load4(row); + d = _mm_add_epi8(d, a); + store3(row, d); + + row += 3; + rb -= 3; + } + if (rb > 0) { + a = d; d = load3(row); + d = _mm_add_epi8(d, a); + store3(row, d); + + row += 3; + rb -= 3; + } +} + +void png_read_filter_row_sub4_sse2(png_row_infop row_info, png_bytep row, + png_const_bytep prev) +{ + /* The Sub filter predicts each pixel as the previous pixel, a. + * There is no pixel to the left of the first pixel. It's encoded directly. + * That works with our main loop if we just say that left pixel was zero. + */ + png_debug(1, "in png_read_filter_row_sub4_sse2"); + __m128i a, d = _mm_setzero_si128(); + + int rb = row_info->rowbytes; + while (rb > 0) { + a = d; d = load4(row); + d = _mm_add_epi8(d, a); + store4(row, d); + + row += 4; + rb -= 4; + } +} + +void png_read_filter_row_avg3_sse2(png_row_infop row_info, png_bytep row, + png_const_bytep prev) +{ + /* The Avg filter predicts each pixel as the (truncated) average of a and b. + * There's no pixel to the left of the first pixel. Luckily, it's + * predicted to be half of the pixel above it. So again, this works + * perfectly with our loop if we make sure a starts at zero. + */ + png_debug(1, "in png_read_filter_row_avg3_sse2"); + const __m128i zero = _mm_setzero_si128(); + __m128i b; + __m128i a, d = zero; + + int rb = row_info->rowbytes; + while (rb >= 4) { + b = load4(prev); + a = d; d = load4(row ); + + /* PNG requires a truncating average, so we can't just use _mm_avg_epu8 */ + __m128i avg = _mm_avg_epu8(a,b); + /* ...but we can fix it up by subtracting off 1 if it rounded up. */ + avg = _mm_sub_epi8(avg, _mm_and_si128(_mm_xor_si128(a,b), + _mm_set1_epi8(1))); + d = _mm_add_epi8(d, avg); + store3(row, d); + + prev += 3; + row += 3; + rb -= 3; + } + if (rb > 0) { + b = load3(prev); + a = d; d = load3(row ); + + /* PNG requires a truncating average, so we can't just use _mm_avg_epu8 */ + __m128i avg = _mm_avg_epu8(a,b); + /* ...but we can fix it up by subtracting off 1 if it rounded up. */ + avg = _mm_sub_epi8(avg, _mm_and_si128(_mm_xor_si128(a,b), + _mm_set1_epi8(1))); + + d = _mm_add_epi8(d, avg); + store3(row, d); + + prev += 3; + row += 3; + rb -= 3; + } +} + +void png_read_filter_row_avg4_sse2(png_row_infop row_info, png_bytep row, + png_const_bytep prev) +{ + /* The Avg filter predicts each pixel as the (truncated) average of a and b. + * There's no pixel to the left of the first pixel. Luckily, it's + * predicted to be half of the pixel above it. So again, this works + * perfectly with our loop if we make sure a starts at zero. + */ + png_debug(1, "in png_read_filter_row_avg4_sse2"); + const __m128i zero = _mm_setzero_si128(); + __m128i b; + __m128i a, d = zero; + + int rb = row_info->rowbytes; + while (rb > 0) { + b = load4(prev); + a = d; d = load4(row ); + + /* PNG requires a truncating average, so we can't just use _mm_avg_epu8 */ + __m128i avg = _mm_avg_epu8(a,b); + /* ...but we can fix it up by subtracting off 1 if it rounded up. */ + avg = _mm_sub_epi8(avg, _mm_and_si128(_mm_xor_si128(a,b), + _mm_set1_epi8(1))); + + d = _mm_add_epi8(d, avg); + store4(row, d); + + prev += 4; + row += 4; + rb -= 4; + } +} + +/* Returns |x| for 16-bit lanes. */ +static __m128i abs_i16(__m128i x) { +#if PNG_INTEL_SSE_IMPLEMENTATION >= 2 + return _mm_abs_epi16(x); +#else + /* Read this all as, return x<0 ? -x : x. + * To negate two's complement, you flip all the bits then add 1. + */ + __m128i is_negative = _mm_cmplt_epi16(x, _mm_setzero_si128()); + + /* Flip negative lanes. */ + x = _mm_xor_si128(x, is_negative); + + /* +1 to negative lanes, else +0. */ + x = _mm_add_epi16(x, _mm_srli_epi16(is_negative, 15)); + return x; +#endif +} + +/* Bytewise c ? t : e. */ +static __m128i if_then_else(__m128i c, __m128i t, __m128i e) { +#if PNG_INTEL_SSE_IMPLEMENTATION >= 3 + return _mm_blendv_epi8(e,t,c); +#else + return _mm_or_si128(_mm_and_si128(c, t), _mm_andnot_si128(c, e)); +#endif +} + +void png_read_filter_row_paeth3_sse2(png_row_infop row_info, png_bytep row, + png_const_bytep prev) +{ + /* Paeth tries to predict pixel d using the pixel to the left of it, a, + * and two pixels from the previous row, b and c: + * prev: c b + * row: a d + * The Paeth function predicts d to be whichever of a, b, or c is nearest to + * p=a+b-c. + * + * The first pixel has no left context, and so uses an Up filter, p = b. + * This works naturally with our main loop's p = a+b-c if we force a and c + * to zero. + * Here we zero b and d, which become c and a respectively at the start of + * the loop. + */ + png_debug(1, "in png_read_filter_row_paeth3_sse2"); + const __m128i zero = _mm_setzero_si128(); + __m128i c, b = zero, + a, d = zero; + + int rb = row_info->rowbytes; + while (rb >= 4) { + /* It's easiest to do this math (particularly, deal with pc) with 16-bit + * intermediates. + */ + c = b; b = _mm_unpacklo_epi8(load4(prev), zero); + a = d; d = _mm_unpacklo_epi8(load4(row ), zero); + + /* (p-a) == (a+b-c - a) == (b-c) */ + __m128i pa = _mm_sub_epi16(b,c); + + /* (p-b) == (a+b-c - b) == (a-c) */ + __m128i pb = _mm_sub_epi16(a,c); + + /* (p-c) == (a+b-c - c) == (a+b-c-c) == (b-c)+(a-c) */ + __m128i pc = _mm_add_epi16(pa,pb); + + pa = abs_i16(pa); /* |p-a| */ + pb = abs_i16(pb); /* |p-b| */ + pc = abs_i16(pc); /* |p-c| */ + + __m128i smallest = _mm_min_epi16(pc, _mm_min_epi16(pa, pb)); + + /* Paeth breaks ties favoring a over b over c. */ + __m128i nearest = if_then_else(_mm_cmpeq_epi16(smallest, pa), a, + if_then_else(_mm_cmpeq_epi16(smallest, pb), b, + c)); + + /* Note `_epi8`: we need addition to wrap modulo 255. */ + d = _mm_add_epi8(d, nearest); + store3(row, _mm_packus_epi16(d,d)); + + prev += 3; + row += 3; + rb -= 3; + } + if (rb > 0) { + /* It's easiest to do this math (particularly, deal with pc) with 16-bit + * intermediates. + */ + c = b; b = _mm_unpacklo_epi8(load3(prev), zero); + a = d; d = _mm_unpacklo_epi8(load3(row ), zero); + + /* (p-a) == (a+b-c - a) == (b-c) */ + __m128i pa = _mm_sub_epi16(b,c); + + /* (p-b) == (a+b-c - b) == (a-c) */ + __m128i pb = _mm_sub_epi16(a,c); + + /* (p-c) == (a+b-c - c) == (a+b-c-c) == (b-c)+(a-c) */ + __m128i pc = _mm_add_epi16(pa,pb); + + pa = abs_i16(pa); /* |p-a| */ + pb = abs_i16(pb); /* |p-b| */ + pc = abs_i16(pc); /* |p-c| */ + + __m128i smallest = _mm_min_epi16(pc, _mm_min_epi16(pa, pb)); + + /* Paeth breaks ties favoring a over b over c. */ + __m128i nearest = if_then_else(_mm_cmpeq_epi16(smallest, pa), a, + if_then_else(_mm_cmpeq_epi16(smallest, pb), b, + c)); + + /* Note `_epi8`: we need addition to wrap modulo 255. */ + d = _mm_add_epi8(d, nearest); + store3(row, _mm_packus_epi16(d,d)); + + prev += 3; + row += 3; + rb -= 3; + } +} + +void png_read_filter_row_paeth4_sse2(png_row_infop row_info, png_bytep row, + png_const_bytep prev) +{ + /* Paeth tries to predict pixel d using the pixel to the left of it, a, + * and two pixels from the previous row, b and c: + * prev: c b + * row: a d + * The Paeth function predicts d to be whichever of a, b, or c is nearest to + * p=a+b-c. + * + * The first pixel has no left context, and so uses an Up filter, p = b. + * This works naturally with our main loop's p = a+b-c if we force a and c + * to zero. + * Here we zero b and d, which become c and a respectively at the start of + * the loop. + */ + png_debug(1, "in png_read_filter_row_paeth4_sse2"); + const __m128i zero = _mm_setzero_si128(); + __m128i c, b = zero, + a, d = zero; + + int rb = row_info->rowbytes; + while (rb > 0) { + /* It's easiest to do this math (particularly, deal with pc) with 16-bit + * intermediates. + */ + c = b; b = _mm_unpacklo_epi8(load4(prev), zero); + a = d; d = _mm_unpacklo_epi8(load4(row ), zero); + + /* (p-a) == (a+b-c - a) == (b-c) */ + __m128i pa = _mm_sub_epi16(b,c); + + /* (p-b) == (a+b-c - b) == (a-c) */ + __m128i pb = _mm_sub_epi16(a,c); + + /* (p-c) == (a+b-c - c) == (a+b-c-c) == (b-c)+(a-c) */ + __m128i pc = _mm_add_epi16(pa,pb); + + pa = abs_i16(pa); /* |p-a| */ + pb = abs_i16(pb); /* |p-b| */ + pc = abs_i16(pc); /* |p-c| */ + + __m128i smallest = _mm_min_epi16(pc, _mm_min_epi16(pa, pb)); + + /* Paeth breaks ties favoring a over b over c. */ + __m128i nearest = if_then_else(_mm_cmpeq_epi16(smallest, pa), a, + if_then_else(_mm_cmpeq_epi16(smallest, pb), b, + c)); + + /* Note `_epi8`: we need addition to wrap modulo 255. */ + d = _mm_add_epi8(d, nearest); + store4(row, _mm_packus_epi16(d,d)); + + prev += 4; + row += 4; + rb -= 4; + } +} + +#endif /* PNG_INTEL_SSE_IMPLEMENTATION > 0 */ +#endif /* READ */ diff --git a/third_party/libpng16/contrib/intel/intel_init.c b/third_party/libpng16/contrib/intel/intel_init.c new file mode 100644 index 0000000000..328e90e9af --- /dev/null +++ b/third_party/libpng16/contrib/intel/intel_init.c @@ -0,0 +1,54 @@ + +/* intel_init.c - SSE2 optimized filter functions + * + * Copyright (c) 2016 Google, Inc. + * Written by Mike Klein and Matt Sarett + * Derived from arm/arm_init.c, which was + * Copyright (c) 2014,2016 Glenn Randers-Pehrson + * + * Last changed in libpng 1.6.22 [May 26, 2016] + * + * This code is released under the libpng license. + * For conditions of distribution and use, see the disclaimer + * and license in png.h + */ + +#include "../../pngpriv.h" + +#ifdef PNG_READ_SUPPORTED +#if PNG_INTEL_SSE_IMPLEMENTATION > 0 + +void +png_init_filter_functions_sse2(png_structp pp, unsigned int bpp) +{ + /* The techniques used to implement each of these filters in SSE operate on + * one pixel at a time. + * So they generally speed up 3bpp images about 3x, 4bpp images about 4x. + * They can scale up to 6 and 8 bpp images and down to 2 bpp images, + * but they'd not likely have any benefit for 1bpp images. + * Most of these can be implemented using only MMX and 64-bit registers, + * but they end up a bit slower than using the equally-ubiquitous SSE2. + */ + png_debug(1, "in png_init_filter_functions_sse2"); + if (bpp == 3) + { + pp->read_filter[PNG_FILTER_VALUE_SUB-1] = png_read_filter_row_sub3_sse2; + pp->read_filter[PNG_FILTER_VALUE_AVG-1] = png_read_filter_row_avg3_sse2; + pp->read_filter[PNG_FILTER_VALUE_PAETH-1] = + png_read_filter_row_paeth3_sse2; + } + else if (bpp == 4) + { + pp->read_filter[PNG_FILTER_VALUE_SUB-1] = png_read_filter_row_sub4_sse2; + pp->read_filter[PNG_FILTER_VALUE_AVG-1] = png_read_filter_row_avg4_sse2; + pp->read_filter[PNG_FILTER_VALUE_PAETH-1] = + png_read_filter_row_paeth4_sse2; + } + + /* No need optimize PNG_FILTER_VALUE_UP. The compiler should + * autovectorize. + */ +} + +#endif /* PNG_INTEL_SSE_IMPLEMENTATION > 0 */ +#endif /* PNG_READ_SUPPORTED */ diff --git a/third_party/libpng16/contrib/intel/intel_sse.patch b/third_party/libpng16/contrib/intel/intel_sse.patch new file mode 100644 index 0000000000..d9d02bb8fc --- /dev/null +++ b/third_party/libpng16/contrib/intel/intel_sse.patch @@ -0,0 +1,164 @@ +diff --git libpng-1.6.22-orig/configure.ac libpng-1.6.22/configure.ac +--- libpng-1.6.22-orig/configure.ac 2016-05-25 18:59:10.000000000 -0400 ++++ libpng-1.6.22/configure.ac 2016-05-25 19:48:10.631751170 -0400 +@@ -341,16 +341,50 @@ AC_ARG_ENABLE([arm-neon], + + AM_CONDITIONAL([PNG_ARM_NEON], + [test "$enable_arm_neon" != 'no' && + case "$host_cpu" in + arm*|aarch64*) :;; + *) test "$enable_arm_neon" != '';; + esac]) + ++# INTEL ++# ===== ++# ++# INTEL SSE (SIMD) support. ++ ++AC_ARG_ENABLE([intel-sse], ++ AS_HELP_STRING([[[--enable-intel-sse]]], ++ [Enable Intel SSE optimizations: =no/off, yes/on:] ++ [no/off: disable the optimizations;] ++ [yes/on: enable the optimizations.] ++ [If not specified: determined by the compiler.]), ++ [case "$enableval" in ++ no|off) ++ # disable the default enabling: ++ AC_DEFINE([PNG_INTEL_SSE_OPT], [0], ++ [Disable Intel SSE optimizations]) ++ # Prevent inclusion of the assembler files below: ++ enable_intel_sse=no;; ++ yes|on) ++ AC_DEFINE([PNG_INTEL_SSE_OPT], [1], ++ [Enable Intel SSE optimizations]);; ++ *) ++ AC_MSG_ERROR([--enable-intel-sse=${enable_intel_sse}: invalid value]) ++ esac]) ++ ++# Add Intel specific files to all builds where the host_cpu is Intel ('x86*') ++# or where Intel optimizations were explicitly requested (this allows a ++# fallback if a future host CPU does not match 'x86*') ++AM_CONDITIONAL([PNG_INTEL_SSE], ++ [test "$enable_intel_sse" != 'no' && ++ case "$host_cpu" in ++ i?86|x86_64) :;; ++ *) test "$enable_intel_sse" != '';; ++ esac]) + AC_MSG_NOTICE([[Extra options for compiler: $PNG_COPTS]]) + + # Config files, substituting as above + AC_CONFIG_FILES([Makefile libpng.pc:libpng.pc.in]) + AC_CONFIG_FILES([libpng-config:libpng-config.in], + [chmod +x libpng-config]) + + AC_OUTPUT +diff --git libpng-1.6.22-orig/Makefile.am libpng-1.6.22/Makefile.am +--- libpng-1.6.22-orig/Makefile.am 2016-05-17 18:15:12.000000000 -0400 ++++ libpng-1.6.22/Makefile.am 2016-05-25 19:48:10.631751170 -0400 +@@ -89,16 +89,20 @@ libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_SO + pngset.c pngtrans.c pngwio.c pngwrite.c pngwtran.c pngwutil.c\ + png.h pngconf.h pngdebug.h pnginfo.h pngpriv.h pngstruct.h pngusr.dfa + + if PNG_ARM_NEON + libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_SOURCES += arm/arm_init.c\ + arm/filter_neon.S arm/filter_neon_intrinsics.c + endif + ++if PNG_INTEL_SSE ++libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_SOURCES += contrib/intel/intel_init.c\ ++ contrib/intel/filter_sse2_intrinsics.c ++endif + nodist_libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_SOURCES = pnglibconf.h + + libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_LDFLAGS = -no-undefined -export-dynamic \ + -version-number @PNGLIB_MAJOR@@PNGLIB_MINOR@:@PNGLIB_RELEASE@:0 + + if HAVE_LD_VERSION_SCRIPT + # Versioned symbols and restricted exports + if HAVE_SOLARIS_LD +diff --git libpng-1.6.22-orig/pngpriv.h libpng-1.6.22/pngpriv.h +--- libpng-1.6.22-orig/pngpriv.h 2016-05-25 18:59:10.000000000 -0400 ++++ libpng-1.6.22/pngpriv.h 2016-05-25 19:48:10.635751171 -0400 +@@ -177,16 +177,52 @@ + # endif /* !PNG_ARM_NEON_IMPLEMENTATION */ + + # ifndef PNG_ARM_NEON_IMPLEMENTATION + /* Use the intrinsics code by default. */ + # define PNG_ARM_NEON_IMPLEMENTATION 1 + # endif + #endif /* PNG_ARM_NEON_OPT > 0 */ + ++#ifndef PNG_INTEL_SSE_OPT ++# ifdef PNG_INTEL_SSE ++ /* Only check for SSE if the build configuration has been modified to ++ * enable SSE optimizations. This means that these optimizations will ++ * be off by default. See contrib/intel for more details. ++ */ ++# if defined(__SSE4_1__) || defined(__AVX__) || defined(__SSSE3__) || \ ++ defined(__SSE2__) || defined(_M_X64) || defined(_M_AMD64) || \ ++ (defined(_M_IX86_FP) && _M_IX86_FP >= 2) ++# define PNG_INTEL_SSE_OPT 1 ++# endif ++# endif ++#endif ++ ++#if PNG_INTEL_SSE_OPT > 0 ++# ifndef PNG_INTEL_SSE_IMPLEMENTATION ++# if defined(__SSE4_1__) || defined(__AVX__) ++ /* We are not actually using AVX, but checking for AVX is the best ++ way we can detect SSE4.1 and SSSE3 on MSVC. ++ */ ++# define PNG_INTEL_SSE_IMPLEMENTATION 3 ++# elif defined(__SSSE3__) ++# define PNG_INTEL_SSE_IMPLEMENTATION 2 ++# elif defined(__SSE2__) || defined(_M_X64) || defined(_M_AMD64) || \ ++ (defined(_M_IX86_FP) && _M_IX86_FP >= 2) ++# define PNG_INTEL_SSE_IMPLEMENTATION 1 ++# else ++# define PNG_INTEL_SSE_IMPLEMENTATION 0 ++# endif ++# endif ++ ++# if PNG_INTEL_SSE_IMPLEMENTATION > 0 ++# define PNG_FILTER_OPTIMIZATIONS png_init_filter_functions_sse2 ++# endif ++#endif ++ + /* Is this a build of a DLL where compilation of the object modules requires + * different preprocessor settings to those required for a simple library? If + * so PNG_BUILD_DLL must be set. + * + * If libpng is used inside a DLL but that DLL does not export the libpng APIs + * PNG_BUILD_DLL must not be set. To avoid the code below kicking in build a + * static library of libpng then link the DLL against that. + */ +@@ -1184,16 +1220,29 @@ PNG_INTERNAL_FUNCTION(void,png_read_filt + row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY); + PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg4_neon,(png_row_infop + row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY); + PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth3_neon,(png_row_infop + row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY); + PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth4_neon,(png_row_infop + row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY); + ++PNG_INTERNAL_FUNCTION(void,png_read_filter_row_sub3_sse2,(png_row_infop ++ row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY); ++PNG_INTERNAL_FUNCTION(void,png_read_filter_row_sub4_sse2,(png_row_infop ++ row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY); ++PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg3_sse2,(png_row_infop ++ row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY); ++PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg4_sse2,(png_row_infop ++ row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY); ++PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth3_sse2,(png_row_infop ++ row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY); ++PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth4_sse2,(png_row_infop ++ row_info, png_bytep row, png_const_bytep prev_row),PNG_EMPTY); ++ + /* Choose the best filter to use and filter the row data */ + PNG_INTERNAL_FUNCTION(void,png_write_find_filter,(png_structrp png_ptr, + png_row_infop row_info),PNG_EMPTY); + + #ifdef PNG_SEQUENTIAL_READ_SUPPORTED + PNG_INTERNAL_FUNCTION(void,png_read_IDAT_data,(png_structrp png_ptr, + png_bytep output, png_alloc_size_t avail_out),PNG_EMPTY); + /* Read 'avail_out' bytes of data from the IDAT stream. If the output buffer |