skia2/third_party/libpng/arm/arm_init.c
scroggo 3965825b97 Check libpng directly into third_party/
With this change, the CMake build, which does not use DEPS to sync
external projects, is able to build and use the same version of libpng
that is used in other builds.

This will allow all platforms (including Google3 CMake build) to test on
the same version of libpng, so we do not need to make SkPngCodec support
all versions of libpng.

- Update CMakeLists.txt to use the checked in libpng.
- Check in libpng version 1.6.22rc01
- Update README.google
- Replace our old LICENSE file with the latest one from libpng
GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2033063003
CQ_EXTRA_TRYBOTS=client.skia.compile:Build-Ubuntu-GCC-x86_64-Release-CMake-Trybot,Build-Mac-Clang-x86_64-Release-CMake-Trybot

Review-Url: https://codereview.chromium.org/2033063003
2016-06-02 12:59:59 -07:00

136 lines
4.6 KiB
C

/* arm_init.c - NEON optimised filter functions
*
* Copyright (c) 2014,2016 Glenn Randers-Pehrson
* Written by Mans Rullgard, 2011.
* Last changed in libpng 1.6.22 [(PENDING RELEASE)]
*
* This code is released under the libpng license.
* For conditions of distribution and use, see the disclaimer
* and license in png.h
*/
/* Below, after checking __linux__, various non-C90 POSIX 1003.1 functions are
* called.
*/
#define _POSIX_SOURCE 1
#include "../pngpriv.h"
#ifdef PNG_READ_SUPPORTED
#if PNG_ARM_NEON_OPT > 0
#ifdef PNG_ARM_NEON_CHECK_SUPPORTED /* Do run-time checks */
/* WARNING: it is strongly recommended that you do not build libpng with
* run-time checks for CPU features if at all possible. In the case of the ARM
* NEON instructions there is no processor-specific way of detecting the
* presence of the required support, therefore run-time detection is extremely
* OS specific.
*
* You may set the macro PNG_ARM_NEON_FILE to the file name of file containing
* a fragment of C source code which defines the png_have_neon function. There
* are a number of implementations in contrib/arm-neon, but the only one that
* has partial support is contrib/arm-neon/linux.c - a generic Linux
* implementation which reads /proc/cpufino.
*/
#ifndef PNG_ARM_NEON_FILE
# ifdef __linux__
# define PNG_ARM_NEON_FILE "contrib/arm-neon/linux.c"
# endif
#endif
#ifdef PNG_ARM_NEON_FILE
#include <signal.h> /* for sig_atomic_t */
static int png_have_neon(png_structp png_ptr);
#include PNG_ARM_NEON_FILE
#else /* PNG_ARM_NEON_FILE */
# error "PNG_ARM_NEON_FILE undefined: no support for run-time ARM NEON checks"
#endif /* PNG_ARM_NEON_FILE */
#endif /* PNG_ARM_NEON_CHECK_SUPPORTED */
#ifndef PNG_ALIGNED_MEMORY_SUPPORTED
# error "ALIGNED_MEMORY is required; set: -DPNG_ALIGNED_MEMORY_SUPPORTED"
#endif
void
png_init_filter_functions_neon(png_structp pp, unsigned int bpp)
{
/* The switch statement is compiled in for ARM_NEON_API, the call to
* png_have_neon is compiled in for ARM_NEON_CHECK. If both are defined
* the check is only performed if the API has not set the NEON option on
* or off explicitly. In this case the check controls what happens.
*
* If the CHECK is not compiled in and the option is UNSET the behavior prior
* to 1.6.7 was to use the NEON code - this was a bug caused by having the
* wrong order of the 'ON' and 'default' cases. UNSET now defaults to OFF,
* as documented in png.h
*/
png_debug(1, "in png_init_filter_functions_neon");
#ifdef PNG_ARM_NEON_API_SUPPORTED
switch ((pp->options >> PNG_ARM_NEON) & 3)
{
case PNG_OPTION_UNSET:
/* Allow the run-time check to execute if it has been enabled -
* thus both API and CHECK can be turned on. If it isn't supported
* this case will fall through to the 'default' below, which just
* returns.
*/
#endif /* PNG_ARM_NEON_API_SUPPORTED */
#ifdef PNG_ARM_NEON_CHECK_SUPPORTED
{
static volatile sig_atomic_t no_neon = -1; /* not checked */
if (no_neon < 0)
no_neon = !png_have_neon(pp);
if (no_neon)
return;
}
#ifdef PNG_ARM_NEON_API_SUPPORTED
break;
#endif
#endif /* PNG_ARM_NEON_CHECK_SUPPORTED */
#ifdef PNG_ARM_NEON_API_SUPPORTED
default: /* OFF or INVALID */
return;
case PNG_OPTION_ON:
/* Option turned on */
break;
}
#endif
/* IMPORTANT: any new external functions used here must be declared using
* PNG_INTERNAL_FUNCTION in ../pngpriv.h. This is required so that the
* 'prefix' option to configure works:
*
* ./configure --with-libpng-prefix=foobar_
*
* Verify you have got this right by running the above command, doing a build
* and examining pngprefix.h; it must contain a #define for every external
* function you add. (Notice that this happens automatically for the
* initialization function.)
*/
pp->read_filter[PNG_FILTER_VALUE_UP-1] = png_read_filter_row_up_neon;
if (bpp == 3)
{
pp->read_filter[PNG_FILTER_VALUE_SUB-1] = png_read_filter_row_sub3_neon;
pp->read_filter[PNG_FILTER_VALUE_AVG-1] = png_read_filter_row_avg3_neon;
pp->read_filter[PNG_FILTER_VALUE_PAETH-1] =
png_read_filter_row_paeth3_neon;
}
else if (bpp == 4)
{
pp->read_filter[PNG_FILTER_VALUE_SUB-1] = png_read_filter_row_sub4_neon;
pp->read_filter[PNG_FILTER_VALUE_AVG-1] = png_read_filter_row_avg4_neon;
pp->read_filter[PNG_FILTER_VALUE_PAETH-1] =
png_read_filter_row_paeth4_neon;
}
}
#endif /* PNG_ARM_NEON_OPT > 0 */
#endif /* READ */