1  /* contrib/arm-neon/android-ndk.c
       2   *
       3   * Copyright (c) 2014 Glenn Randers-Pehrson
       4   * Written by John Bowler, 2014.
       5   *
       6   * This code is released under the libpng license.
       7   * For conditions of distribution and use, see the disclaimer
       8   * and license in png.h
       9   *
      10   * SEE contrib/arm-neon/README before reporting bugs
      11   *
      12   * STATUS: COMPILED, UNTESTED
      13   * BUG REPORTS: png-mng-implement@sourceforge.net
      14   *
      15   * png_have_neon implemented for the Android NDK, see:
      16   *
      17   * Documentation:
      18   *    http://www.kandroid.org/ndk/docs/CPU-ARM-NEON.html
      19   *    https://code.google.com/p/android/issues/detail?id=49065
      20   *
      21   * NOTE: this requires that libpng is built against the Android NDK and linked
      22   * with an implementation of the Android ARM 'cpu-features' library.  The code
      23   * has been compiled only, not linked: no version of the library has been found,
      24   * only the header files exist in the NDK.
      25   */
      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  }