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