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  *    https://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
png_have_neon(png_structp png_ptr)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 }
40