dba54b8888
implementation of the ARM NEON discovery function to be set at build-time and provide sample implementations from the current code in the contrib/arm-neon subdirectory. The __linux__ code has also been changed to compile and link on Android by using /proc/cpuinfo, and the old linux code is in contrib/arm-neon/linux-auxv.c. The new code avoids POSIX and Linux dependencies apart from opening /proc/cpuinfo and is C90 compliant.
40 lines
1.3 KiB
C
40 lines
1.3 KiB
C
/* contrib/arm-neon/android-ndk.c
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*
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* Copyright (c) 2014 Glenn Randers-Pehrson
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* Written by John Bowler, 2014.
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* Last changed in libpng 1.6.10 [(PENDING RELEASE)]
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*
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* This code is released under the libpng license.
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* For conditions of distribution and use, see the disclaimer
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* and license in png.h
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*
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* SEE contrib/arm-neon/README before reporting bugs
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*
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* STATUS: COMPILED, UNTESTED
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* BUG REPORTS: png-mng-implement@sourceforge.net
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*
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* png_have_neon implemented for the Android NDK, see:
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*
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* Documentation:
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* http://www.kandroid.org/ndk/docs/CPU-ARM-NEON.html
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* http://code.google.com/p/android/issues/detail?id=49065
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*
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* NOTE: this requires that libpng is built against the Android NDK and linked
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* with an implementation of the Android ARM 'cpu-features' library. The code
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* has been compiled only, not linked: no version of the library has been found,
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* only the header files exist in the NDK.
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*/
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#include <cpu-features.h>
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static int
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png_have_neon(png_structp png_ptr)
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{
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/* This is a whole lot easier than the linux code, however it is probably
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* implemented as below, therefore it is better to cache the result (these
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* function calls may be slow!)
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*/
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PNG_UNUSED(png_ptr)
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return android_getCpuFamily() == ANDROID_CPU_FAMILY_ARM &&
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(android_getCpuFeatures() & ANDROID_CPU_ARM_FEATURE_NEON) != 0;
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}
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