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Member "pngcrush-1.8.13/powerpc_init.c" (16 Mar 2017, 4319 Bytes) of package /linux/privat/pngcrush-1.8.13.tar.gz:


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    1 
    2 /* powerpc_init.c - POWERPC optimised filter functions
    3  *
    4  * Copyright (c) 2017 Glenn Randers-Pehrson
    5  * Written by Vadim Barkov, 2017.
    6  * Last changed in libpng 1.6.29 [(PENDING RELEASE)]
    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_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 */