source/libs/libpng/libpng-src/mips/mips_init.c

   1
   2 /* mips_init.c - MSA optimised filter functions
   3  *
   4  * Copyright (c) 2016 Glenn Randers-Pehrson
   5  * Written by Mandar Sahastrabuddhe, 2016.
   6  * Last changed in libpng 1.6.25 [September 1, 2016]
   7  *
   8  * This code is released under the libpng license.
   9  * For conditions of distribution and use, see the disclaimer
  10  * and license in png.h
  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_MIPS_MSA_OPT > 0
  23 #ifdef PNG_MIPS_MSA_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 MIPS
  26  * MSA 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_MIPS_MSA_FILE to the file name of file containing
  31  * a fragment of C source code which defines the png_have_msa function.  There
  32  * are a number of implementations in contrib/mips-msa, but the only one that
  33  * has partial support is contrib/mips-msa/linux.c - a generic Linux
  34  * implementation which reads /proc/cpufino.
  35  */
  36 #ifndef PNG_MIPS_MSA_FILE
  37 #  ifdef __linux__
  38 #     define PNG_MIPS_MSA_FILE "contrib/mips-msa/linux.c"
  39 #  endif
  40 #endif
  41
  42 #ifdef PNG_MIPS_MSA_FILE
  43
  44 #include <signal.h> /* for sig_atomic_t */
  45 static int png_have_msa(png_structp png_ptr);
  46 #include PNG_MIPS_MSA_FILE
  47
  48 #else  /* PNG_MIPS_MSA_FILE */
  49 #  error "PNG_MIPS_MSA_FILE undefined: no support for run-time MIPS MSA checks"
  50 #endif /* PNG_MIPS_MSA_FILE */
  51 #endif /* PNG_MIPS_MSA_CHECK_SUPPORTED */
  52
  53 #ifndef PNG_ALIGNED_MEMORY_SUPPORTED
  54 #  error "ALIGNED_MEMORY is required; set: -DPNG_ALIGNED_MEMORY_SUPPORTED"
  55 #endif
  56
  57 void
  58 png_init_filter_functions_msa(png_structp pp, unsigned int bpp)
  59 {
  60    /* The switch statement is compiled in for MIPS_MSA_API, the call to
  61     * png_have_msa is compiled in for MIPS_MSA_CHECK. If both are defined
  62     * the check is only performed if the API has not set the MSA option on
  63     * or off explicitly. In this case the check controls what happens.
  64     */
  65
  66 #ifdef PNG_MIPS_MSA_API_SUPPORTED
  67    switch ((pp->options >> PNG_MIPS_MSA) & 3)
  68    {
  69       case PNG_OPTION_UNSET:
  70          /* Allow the run-time check to execute if it has been enabled -
  71           * thus both API and CHECK can be turned on.  If it isn't supported
  72           * this case will fall through to the 'default' below, which just
  73           * returns.
  74           */
  75 #endif /* PNG_MIPS_MSA_API_SUPPORTED */
  76 #ifdef PNG_MIPS_MSA_CHECK_SUPPORTED
  77          {
  78             static volatile sig_atomic_t no_msa = -1; /* not checked */
  79
  80             if (no_msa < 0)
  81                no_msa = !png_have_msa(pp);
  82
  83             if (no_msa)
  84                return;
  85          }
  86 #ifdef PNG_MIPS_MSA_API_SUPPORTED
  87          break;
  88 #endif
  89 #endif /* PNG_MIPS_MSA_CHECK_SUPPORTED */
  90
  91 #ifdef PNG_MIPS_MSA_API_SUPPORTED
  92       default: /* OFF or INVALID */
  93          return;
  94
  95       case PNG_OPTION_ON:
  96          /* Option turned on */
  97          break;
  98    }
  99 #endif
 100
 101    /* IMPORTANT: any new external functions used here must be declared using
 102     * PNG_INTERNAL_FUNCTION in ../pngpriv.h.  This is required so that the
 103     * 'prefix' option to configure works:
 104     *
 105     *    ./configure --with-libpng-prefix=foobar_
 106     *
 107     * Verify you have got this right by running the above command, doing a build
 108     * and examining pngprefix.h; it must contain a #define for every external
 109     * function you add.  (Notice that this happens automatically for the
 110     * initialization function.)
 111     */
 112    pp->read_filter[PNG_FILTER_VALUE_UP-1] = png_read_filter_row_up_msa;
 113
 114    if (bpp == 3)
 115    {
 116       pp->read_filter[PNG_FILTER_VALUE_SUB-1] = png_read_filter_row_sub3_msa;
 117       pp->read_filter[PNG_FILTER_VALUE_AVG-1] = png_read_filter_row_avg3_msa;
 118       pp->read_filter[PNG_FILTER_VALUE_PAETH-1] = png_read_filter_row_paeth3_msa;
 119    }
 120
 121    else if (bpp == 4)
 122    {
 123       pp->read_filter[PNG_FILTER_VALUE_SUB-1] = png_read_filter_row_sub4_msa;
 124       pp->read_filter[PNG_FILTER_VALUE_AVG-1] = png_read_filter_row_avg4_msa;
 125       pp->read_filter[PNG_FILTER_VALUE_PAETH-1] = png_read_filter_row_paeth4_msa;
 126    }
 127 }
 128 #endif /* PNG_MIPS_MSA_OPT > 0 */
 129 #endif /* READ */