| /* Compile time options. |
| * ===================== |
| * In a multi-arch build the compiler may compile the code several times for the |
| * same object module, producing different binaries for different architectures. |
| * When this happens configure-time setting of the target host options cannot be |
| * done. An example is iOS vs Android compilation of ARM NEON support. |
| * |
| * NOTE: symbol prefixing does not pass $(CFLAGS) to the preprocessor, because |
| * this is not possible with certain compilers (Oracle SUN OS CC), as a result |
| * it is necessary to ensure that all extern functions that *might* be used |
| * regardless of $(CFLAGS) get declared in this file. The test on __ARM_NEON |
| * below is one example of this behavior because it is controlled by the |
| * presence or not of -mfpu=neon on the GCC command line, it is possible to do |
| * this in $(CC), e.g. "CC=gcc -mfpu=neon", but people who build libpng rarely |
| * do this. |
| */ |
| #ifndef PNG_ARM_NEON_OPT |
| /* ARM NEON optimizations are being controlled by the compiler settings, |
| * typically the target FPU. If the FPU supports NEON instructions then the |
| * compiler will define __ARM_NEON and we can rely unconditionally on NEON |
| * instructions not crashing, otherwise we must disable use of NEON |
| * instructions. |
| * |
| * NOTE: at present these optimizations depend on 'ALIGNED_MEMORY', so they |
| * can only be turned on automatically if that is supported too. If |
| * PNG_ARM_NEON_OPT is set in CPPFLAGS (to >0) then arm/arm_init.c will fail |
| * to compile with an appropriate #error if ALIGNED_MEMORY has been turned |
| * off. |
| * |
| * Note that older versions of GCC defined __ARM_NEON__; this is no longer |
| * supported. Also 32-bit ARM versions of GCC required the NEON FPU mode to |
| * be turned on explicitly on the command line. If this is not done (on |
| * 32-bit ARM) NEON code will not be included. |
| * |
| * To disable ARM_NEON optimizations entirely, and skip compiling the |
| * associated assembler code, pass --enable-arm-neon=no to configure |
| * or put -DPNG_ARM_NEON_OPT=0 in CPPFLAGS. |
| */ |
| # if defined(__ARM_NEON) && defined(PNG_ALIGNED_MEMORY_SUPPORTED) |
| # define PNG_ARM_NEON_OPT 2 |
| # else |
| # define PNG_ARM_NEON_OPT 0 |
| # endif |
| #endif |
| |
| #if PNG_ARM_NEON_OPT > 0 |
| /* NEON optimizations are to be at least considered by libpng, so enable the |
| * callbacks to do this. |
| */ |
| # define PNG_FILTER_OPTIMIZATIONS png_init_filter_functions_neon |
| |
| /* By default the 'intrinsics' code in arm/filter_neon_intrinsics.c is used |
| * if possible - if __ARM_NEON is set and the compiler version is not known |
| * to be broken. This is controlled by PNG_ARM_NEON_IMPLEMENTATION which can |
| * be: |
| * |
| * 1 The intrinsics code (the default with __ARM_NEON) |
| * 2 The hand coded assembler (the default without __ARM_NEON) |
| * |
| * It is possible to set PNG_ARM_NEON_IMPLEMENTATION in CPPFLAGS, however |
| * this is *NOT* supported and may cease to work even after a minor revision |
| * to libpng. It *is* valid to do this for testing purposes, e.g. speed |
| * testing or a new compiler, but the results should be communicated to the |
| * libpng implementation list for incorporation in the next minor release. |
| */ |
| # ifndef PNG_ARM_NEON_IMPLEMENTATION |
| # ifdef __ARM_NEON |
| # if defined(__clang__) |
| /* At present it is unknown by the libpng developers which versions |
| * of clang support the intrinsics, however some or perhaps all |
| * versions do not work with the assembler so this may be |
| * irrelevant, so just use the default (do nothing here.) |
| */ |
| # elif defined(__GNUC__) |
| /* GCC 4.5.4 NEON support is known to be broken. 4.6.3 is known to |
| * work, so if this *is* GCC, or G++, look for a version >4.5 |
| */ |
| # if __GNUC__ < 4 || (__GNUC__ == 4 && __GNUC_MINOR__ < 6) |
| # define PNG_ARM_NEON_IMPLEMENTATION 2 |
| # endif /* no GNUC support */ |
| # endif /* __GNUC__ */ |
| # else /* !defined __ARM_NEON */ |
| /* The 'intrinsics' code simply won't compile without compiler support |
| * and that support switches on __ARM_NEON, so use the assembler: |
| */ |
| # define PNG_ARM_NEON_IMPLEMENTATION 2 |
| # endif /* __ARM_NEON */ |
| # endif /* !defined PNG_ARM_NEON_IMPLEMENTATION */ |
| |
| # ifndef PNG_ARM_NEON_IMPLEMENTATION |
| /* Use the intrinsics code by default. */ |
| # define PNG_ARM_NEON_IMPLEMENTATION 1 |
| # endif |
| #endif /* PNG_ARM_NEON_OPT > 0 */ |
| |
| #ifdef PNG_SET_OPTION_SUPPORTED |
| #ifdef PNG_ARM_NEON_API_SUPPORTED |
| # define PNG_ARM_NEON 0 /* HARDWARE: ARM Neon SIMD instructions supported */ |
| #endif |
| #endif /* SET_OPTION */ |
| |
| #if PNG_ARM_NEON_OPT > 0 |
| PNG_INTERNAL_FUNCTION(void,png_read_filter_row_up_neon, |
| (png_alloc_size_t row_bytes, unsigned int bpp, png_bytep row, |
| png_const_bytep prev_row),PNG_EMPTY); |
| PNG_INTERNAL_FUNCTION(void,png_read_filter_row_sub3_neon, |
| (png_alloc_size_t row_bytes, unsigned int bpp, png_bytep row, |
| png_const_bytep prev_row),PNG_EMPTY); |
| PNG_INTERNAL_FUNCTION(void,png_read_filter_row_sub4_neon, |
| (png_alloc_size_t row_bytes, unsigned int bpp, png_bytep row, |
| png_const_bytep prev_row),PNG_EMPTY); |
| PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg3_neon, |
| (png_alloc_size_t row_bytes, unsigned int bpp, png_bytep row, |
| png_const_bytep prev_row),PNG_EMPTY); |
| PNG_INTERNAL_FUNCTION(void,png_read_filter_row_avg4_neon, |
| (png_alloc_size_t row_bytes, unsigned int bpp, png_bytep row, |
| png_const_bytep prev_row),PNG_EMPTY); |
| PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth3_neon, |
| (png_alloc_size_t row_bytes, unsigned int bpp, png_bytep row, |
| png_const_bytep prev_row),PNG_EMPTY); |
| PNG_INTERNAL_FUNCTION(void,png_read_filter_row_paeth4_neon, |
| (png_alloc_size_t row_bytes, unsigned int bpp, png_bytep row, |
| png_const_bytep prev_row),PNG_EMPTY); |
| #endif |
