libpng/arm/arm_init.c
John Bowler 62cfc893e0 [libpng15] Rearranged building of ARM NEON optimizations. The ARM specific code
is split out entirely to the arm subdirectory and changes to configure.ac and
Makefile.am to add new stuff are reduced.  Now material code changes,
although for build test purposes, --enable-arm-neon now builds on non-ARM
systems.
Rebuilt Makefile.in, configure, etc., with autoconf-2.69 and automake-1.2.5.
2012-12-14 22:05:08 -06:00

75 lines
1.7 KiB
C

/* filter_neon.S - NEON optimised filter functions
*
* Copyright (c) 2011 Glenn Randers-Pehrson
* Written by Mans Rullgard, 2011.
*
* 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"
/* __arm__ is defined by GCC, MSVC defines _M_ARM to the ARM version number */
#if defined __linux__ && defined __arm__
#include <stdio.h>
#include <elf.h>
#include <asm/hwcap.h>
static int png_have_hwcap(unsigned cap)
{
FILE *f = fopen("/proc/self/auxv", "r");
Elf32_auxv_t aux;
int have_cap = 0;
if (!f)
return 0;
while (fread(&aux, sizeof(aux), 1, f) > 0)
{
if (aux.a_type == AT_HWCAP &&
aux.a_un.a_val & cap)
{
have_cap = 1;
break;
}
}
fclose(f);
return have_cap;
}
#endif /* __linux__ && __arm__ */
void
png_init_filter_functions_neon(png_structp pp, unsigned int bpp)
{
#ifdef __arm__
#ifdef __linux__
if (!png_have_hwcap(HWCAP_NEON))
return;
#endif
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;
}
#else
PNG_UNUSED(pp)
PNG_UNUSED(bpp)
#endif
}