[libpng16] Updated INSTALL instructions for intel SSE code

This commit is contained in:
Glenn Randers-Pehrson 2016-02-23 09:29:08 -06:00
parent b4f9f5d041
commit e2d113cadf
2 changed files with 13 additions and 5 deletions

View File

@ -47,7 +47,9 @@ If configure does not work on your system, or if you have a need to
change configure.ac or Makefile.am, and you have a reasonably
up-to-date set of tools, running ./autogen.sh in a git clone before
running ./configure may fix the problem. To be really sure that you
aren't using any of the included pre-built scripts, you can do this:
aren't using any of the included pre-built scripts, especially if you
are building from a tar distribution instead of a git distribution,
do this:
./configure --enable-maintainer-mode
make maintainer-clean

View File

@ -4,17 +4,23 @@ Copyright (c) 2016 Google, Inc.
Written by Mike Klein and Matt Sarett
To enable SSE support in libpng, apply intel_sse.patch in your build
directory. If you prefer, manually edit configure.ac and Makefile.am,
following the instructions below.
directory, before running "configure". If you prefer, manually edit
configure.ac and Makefile.am, following the instructions below, then
then follow the instructions in section II of INSTALL in the main libpng
directory.
Then configure libpng with -DPNG_INTEL_SSE in CPPFLAGS.
If you only want to optimize 4bpp images, also use -DPNG_NO_INTEL_SSE_3BPP.
Then configure libpng with -DPNG_INTEL_SSE in CPPFLAGS. If you only
want to optimize reading 4bpp images, also use -DPNG_NO_INTEL_SSE_3BPP.
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.
If you are using a custom makefile instead of a configure-generated
makefile, you will have to update it manually to include contrib/intel/*.c
and to define PNG_INTEL_SSE and possibly PNG_NO_INTEL_SSE_3BPP.
1. Insert the following lines above the copyright line near the top of
configure.ac: