source/libs/libpng/libpng-1.6.15/contrib/arm-neon/android-ndk.c

   1 /* contrib/arm-neon/android-ndk.c
   2  *
   3  * Copyright (c) 2014 Glenn Randers-Pehrson
   4  * Written by John Bowler, 2014.
   5  * Last changed in libpng 1.6.10 [March 6, 2014]
   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  * SEE contrib/arm-neon/README before reporting bugs
  12  *
  13  * STATUS: COMPILED, UNTESTED
  14  * BUG REPORTS: png-mng-implement@sourceforge.net
  15  *
  16  * png_have_neon implemented for the Android NDK, see:
  17  *
  18  * Documentation:
  19  *    http://www.kandroid.org/ndk/docs/CPU-ARM-NEON.html
  20  *    http://code.google.com/p/android/issues/detail?id=49065
  21  *
  22  * NOTE: this requires that libpng is built against the Android NDK and linked
  23  * with an implementation of the Android ARM 'cpu-features' library.  The code
  24  * has been compiled only, not linked: no version of the library has been found,
  25  * only the header files exist in the NDK.
  26  */
  27 #include <cpu-features.h>
  28
  29 static int
  30 png_have_neon(png_structp png_ptr)
  31 {
  32    /* This is a whole lot easier than the linux code, however it is probably
  33     * implemented as below, therefore it is better to cache the result (these
  34     * function calls may be slow!)
  35     */
  36    PNG_UNUSED(png_ptr)
  37    return android_getCpuFamily() == ANDROID_CPU_FAMILY_ARM &&
  38       (android_getCpuFeatures() & ANDROID_CPU_ARM_FEATURE_NEON) != 0;
  39 }