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Diffstat (limited to 'third_party/libpng16/contrib/intel/INSTALL')
| -rw-r--r-- | third_party/libpng16/contrib/intel/INSTALL | 158 |
1 files changed, 158 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---------------- |