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[libpng17] Rearranged ARM-NEON optimizations to isolate the machine specific

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code to the hardware subdirectory, and add comments to pngrutil.c so that
implementors of other optimizations will know what to do.
This commit is contained in:
John Bowler
2012-12-14 23:12:16 -06:00
committed by Glenn Randers-Pehrson
parent eac85878bf
commit 0f2a5bac64
8 changed files with 110 additions and 67 deletions
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74
arm/arm_init.c Normal file
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@@ -0,0 +1,74 @@
/* 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
}