/* powerpc_init.c - POWERPC optimised filter functions
*
* Copyright (c) 2018 Cosmin Truta
* Copyright (c) 2017 Glenn Randers-Pehrson
* Written by Vadim Barkov, 2017.
*
* 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 <stdio.h>
#include "../pngpriv.h"
#ifdef PNG_READ_SUPPORTED
#if PNG_POWERPC_VSX_OPT > 0
#ifdef PNG_POWERPC_VSX_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 PowerPC
* VSX 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_POWERPC_VSX_FILE to the file name of file containing
* a fragment of C source code which defines the png_have_vsx function. There
* are a number of implementations in contrib/powerpc-vsx, but the only one that
* has partial support is contrib/powerpc-vsx/linux.c - a generic Linux
* implementation which reads /proc/cpufino.
*/
#ifndef PNG_POWERPC_VSX_FILE
# ifdef __linux__
# define PNG_POWERPC_VSX_FILE "contrib/powerpc-vsx/linux_aux.c"
# endif
#endif
#ifdef PNG_POWERPC_VSX_FILE
#include <signal.h> /* for sig_atomic_t */
static int png_have_vsx(png_structp png_ptr);
#include PNG_POWERPC_VSX_FILE
#else /* PNG_POWERPC_VSX_FILE */
# error "PNG_POWERPC_VSX_FILE undefined: no support for run-time POWERPC VSX checks"
#endif /* PNG_POWERPC_VSX_FILE */
#endif /* PNG_POWERPC_VSX_CHECK_SUPPORTED */
void
png_init_filter_functions_vsx(png_structp pp, unsigned int bpp)
{
/* The switch statement is compiled in for POWERPC_VSX_API, the call to
* png_have_vsx is compiled in for POWERPC_VSX_CHECK. If both are defined
* the check is only performed if the API has not set the PowerPC option on
* or off explicitly. In this case the check controls what happens.
*/
#ifdef PNG_POWERPC_VSX_API_SUPPORTED
switch ((pp->options >> PNG_POWERPC_VSX) & 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_POWERPC_VSX_API_SUPPORTED */
#ifdef PNG_POWERPC_VSX_CHECK_SUPPORTED
{
static volatile sig_atomic_t no_vsx = -1; /* not checked */
if (no_vsx < 0)
no_vsx = !png_have_vsx(pp);
if (no_vsx)
return;
}
#ifdef PNG_POWERPC_VSX_API_SUPPORTED
break;
#endif
#endif /* PNG_POWERPC_VSX_CHECK_SUPPORTED */
#ifdef PNG_POWERPC_VSX_API_SUPPORTED
default: /* OFF or INVALID */
return;
case PNG_OPTION_ON:
/* Option turned on */
break;
}
#endif
/* IMPORTANT: any new internal 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_vsx;
if (bpp == 3)
{
pp->read_filter[PNG_FILTER_VALUE_SUB-1] = png_read_filter_row_sub3_vsx;
pp->read_filter[PNG_FILTER_VALUE_AVG-1] = png_read_filter_row_avg3_vsx;
pp->read_filter[PNG_FILTER_VALUE_PAETH-1] = png_read_filter_row_paeth3_vsx;
}
else if (bpp == 4)
{
pp->read_filter[PNG_FILTER_VALUE_SUB-1] = png_read_filter_row_sub4_vsx;
pp->read_filter[PNG_FILTER_VALUE_AVG-1] = png_read_filter_row_avg4_vsx;
pp->read_filter[PNG_FILTER_VALUE_PAETH-1] = png_read_filter_row_paeth4_vsx;
}
}
#endif /* PNG_POWERPC_VSX_OPT > 0 */
#endif /* READ */
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