powerpc_init.c (4302B)
1 /* powerpc_init.c - POWERPC optimised filter functions 2 * 3 * Copyright (c) 2018 Cosmin Truta 4 * Copyright (c) 2017 Glenn Randers-Pehrson 5 * Written by Vadim Barkov, 2017. 6 * 7 * This code is released under the libpng license. 8 * For conditions of distribution and use, see the disclaimer 9 * and license in png.h 10 */ 11 12 /* Below, after checking __linux__, various non-C90 POSIX 1003.1 functions are 13 * called. 14 */ 15 #define _POSIX_SOURCE 1 16 17 #include <stdio.h> 18 #include "../pngpriv.h" 19 20 #ifdef PNG_READ_SUPPORTED 21 22 #if PNG_POWERPC_VSX_OPT > 0 23 #ifdef PNG_POWERPC_VSX_CHECK_SUPPORTED /* Do run-time checks */ 24 /* WARNING: it is strongly recommended that you do not build libpng with 25 * run-time checks for CPU features if at all possible. In the case of the PowerPC 26 * VSX instructions there is no processor-specific way of detecting the 27 * presence of the required support, therefore run-time detection is extremely 28 * OS specific. 29 * 30 * You may set the macro PNG_POWERPC_VSX_FILE to the file name of file containing 31 * a fragment of C source code which defines the png_have_vsx function. There 32 * are a number of implementations in contrib/powerpc-vsx, but the only one that 33 * has partial support is contrib/powerpc-vsx/linux.c - a generic Linux 34 * implementation which reads /proc/cpufino. 35 */ 36 #ifndef PNG_POWERPC_VSX_FILE 37 # ifdef __linux__ 38 # define PNG_POWERPC_VSX_FILE "contrib/powerpc-vsx/linux_aux.c" 39 # endif 40 #endif 41 42 #ifdef PNG_POWERPC_VSX_FILE 43 44 #include <signal.h> /* for sig_atomic_t */ 45 static int png_have_vsx(png_structp png_ptr); 46 #include PNG_POWERPC_VSX_FILE 47 48 #else /* PNG_POWERPC_VSX_FILE */ 49 # error PNG_POWERPC_VSX_FILE undefined: no support for run-time POWERPC VSX checks 50 #endif /* PNG_POWERPC_VSX_FILE */ 51 #endif /* PNG_POWERPC_VSX_CHECK_SUPPORTED */ 52 53 void 54 png_init_filter_functions_vsx(png_structp pp, unsigned int bpp) 55 { 56 /* The switch statement is compiled in for POWERPC_VSX_API, the call to 57 * png_have_vsx is compiled in for POWERPC_VSX_CHECK. If both are defined 58 * the check is only performed if the API has not set the PowerPC option on 59 * or off explicitly. In this case the check controls what happens. 60 */ 61 62 #ifdef PNG_POWERPC_VSX_API_SUPPORTED 63 switch ((pp->options >> PNG_POWERPC_VSX) & 3) 64 { 65 case PNG_OPTION_UNSET: 66 /* Allow the run-time check to execute if it has been enabled - 67 * thus both API and CHECK can be turned on. If it isn't supported 68 * this case will fall through to the 'default' below, which just 69 * returns. 70 */ 71 #endif /* PNG_POWERPC_VSX_API_SUPPORTED */ 72 #ifdef PNG_POWERPC_VSX_CHECK_SUPPORTED 73 { 74 static volatile sig_atomic_t no_vsx = -1; /* not checked */ 75 76 if (no_vsx < 0) 77 no_vsx = !png_have_vsx(pp); 78 79 if (no_vsx) 80 return; 81 } 82 #ifdef PNG_POWERPC_VSX_API_SUPPORTED 83 break; 84 #endif 85 #endif /* PNG_POWERPC_VSX_CHECK_SUPPORTED */ 86 87 #ifdef PNG_POWERPC_VSX_API_SUPPORTED 88 default: /* OFF or INVALID */ 89 return; 90 91 case PNG_OPTION_ON: 92 /* Option turned on */ 93 break; 94 } 95 #endif 96 97 /* IMPORTANT: any new internal functions used here must be declared using 98 * PNG_INTERNAL_FUNCTION in ../pngpriv.h. This is required so that the 99 * 'prefix' option to configure works: 100 * 101 * ./configure --with-libpng-prefix=foobar_ 102 * 103 * Verify you have got this right by running the above command, doing a build 104 * and examining pngprefix.h; it must contain a #define for every external 105 * function you add. (Notice that this happens automatically for the 106 * initialization function.) 107 */ 108 pp->read_filter[PNG_FILTER_VALUE_UP-1] = png_read_filter_row_up_vsx; 109 110 if (bpp == 3) 111 { 112 pp->read_filter[PNG_FILTER_VALUE_SUB-1] = png_read_filter_row_sub3_vsx; 113 pp->read_filter[PNG_FILTER_VALUE_AVG-1] = png_read_filter_row_avg3_vsx; 114 pp->read_filter[PNG_FILTER_VALUE_PAETH-1] = png_read_filter_row_paeth3_vsx; 115 } 116 117 else if (bpp == 4) 118 { 119 pp->read_filter[PNG_FILTER_VALUE_SUB-1] = png_read_filter_row_sub4_vsx; 120 pp->read_filter[PNG_FILTER_VALUE_AVG-1] = png_read_filter_row_avg4_vsx; 121 pp->read_filter[PNG_FILTER_VALUE_PAETH-1] = png_read_filter_row_paeth4_vsx; 122 } 123 } 124 #endif /* PNG_POWERPC_VSX_OPT > 0 */ 125 #endif /* READ */