/* 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 */