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Diffstat (limited to 'third_party/libpng16/arm/arm_init.c')
| -rw-r--r-- | third_party/libpng16/arm/arm_init.c | 135 |
1 files changed, 135 insertions, 0 deletions
diff --git a/third_party/libpng16/arm/arm_init.c b/third_party/libpng16/arm/arm_init.c new file mode 100644 index 0000000000..02df812e77 --- /dev/null +++ b/third_party/libpng16/arm/arm_init.c @@ -0,0 +1,135 @@ + +/* arm_init.c - NEON optimised filter functions + * + * Copyright (c) 2014,2016 Glenn Randers-Pehrson + * Written by Mans Rullgard, 2011. + * Last changed in libpng 1.6.22 [May 26, 2016] + * + * This code is released under the libpng license. + * For conditions of distribution and use, see the disclaimer + * and license in png.h + */ +/* Below, after checking __linux__, various non-C90 POSIX 1003.1 functions are + * called. + */ +#define _POSIX_SOURCE 1 + +#include "../pngpriv.h" + +#ifdef PNG_READ_SUPPORTED + +#if PNG_ARM_NEON_OPT > 0 +#ifdef PNG_ARM_NEON_CHECK_SUPPORTED /* Do run-time checks */ +/* WARNING: it is strongly recommended that you do not build libpng with + * run-time checks for CPU features if at all possible. In the case of the ARM + * NEON instructions there is no processor-specific way of detecting the + * presence of the required support, therefore run-time detection is extremely + * OS specific. + * + * You may set the macro PNG_ARM_NEON_FILE to the file name of file containing + * a fragment of C source code which defines the png_have_neon function. There + * are a number of implementations in contrib/arm-neon, but the only one that + * has partial support is contrib/arm-neon/linux.c - a generic Linux + * implementation which reads /proc/cpufino. + */ +#ifndef PNG_ARM_NEON_FILE +# ifdef __linux__ +# define PNG_ARM_NEON_FILE "contrib/arm-neon/linux.c" +# endif +#endif + +#ifdef PNG_ARM_NEON_FILE + +#include <signal.h> /* for sig_atomic_t */ +static int png_have_neon(png_structp png_ptr); +#include PNG_ARM_NEON_FILE + +#else /* PNG_ARM_NEON_FILE */ +# error "PNG_ARM_NEON_FILE undefined: no support for run-time ARM NEON checks" +#endif /* PNG_ARM_NEON_FILE */ +#endif /* PNG_ARM_NEON_CHECK_SUPPORTED */ + +#ifndef PNG_ALIGNED_MEMORY_SUPPORTED +# error "ALIGNED_MEMORY is required; set: -DPNG_ALIGNED_MEMORY_SUPPORTED" +#endif + +void +png_init_filter_functions_neon(png_structp pp, unsigned int bpp) +{ + /* The switch statement is compiled in for ARM_NEON_API, the call to + * png_have_neon is compiled in for ARM_NEON_CHECK. If both are defined + * the check is only performed if the API has not set the NEON option on + * or off explicitly. In this case the check controls what happens. + * + * If the CHECK is not compiled in and the option is UNSET the behavior prior + * to 1.6.7 was to use the NEON code - this was a bug caused by having the + * wrong order of the 'ON' and 'default' cases. UNSET now defaults to OFF, + * as documented in png.h + */ + png_debug(1, "in png_init_filter_functions_neon"); +#ifdef PNG_ARM_NEON_API_SUPPORTED + switch ((pp->options >> PNG_ARM_NEON) & 3) + { + case PNG_OPTION_UNSET: + /* Allow the run-time check to execute if it has been enabled - + * thus both API and CHECK can be turned on. If it isn't supported + * this case will fall through to the 'default' below, which just + * returns. + */ +#endif /* PNG_ARM_NEON_API_SUPPORTED */ +#ifdef PNG_ARM_NEON_CHECK_SUPPORTED + { + static volatile sig_atomic_t no_neon = -1; /* not checked */ + + if (no_neon < 0) + no_neon = !png_have_neon(pp); + + if (no_neon) + return; + } +#ifdef PNG_ARM_NEON_API_SUPPORTED + break; +#endif +#endif /* PNG_ARM_NEON_CHECK_SUPPORTED */ + +#ifdef PNG_ARM_NEON_API_SUPPORTED + default: /* OFF or INVALID */ + return; + + case PNG_OPTION_ON: + /* Option turned on */ + break; + } +#endif + + /* IMPORTANT: any new external functions used here must be declared using + * PNG_INTERNAL_FUNCTION in ../pngpriv.h. This is required so that the + * 'prefix' option to configure works: + * + * ./configure --with-libpng-prefix=foobar_ + * + * Verify you have got this right by running the above command, doing a build + * and examining pngprefix.h; it must contain a #define for every external + * function you add. (Notice that this happens automatically for the + * initialization function.) + */ + pp->read_filter[PNG_FILTER_VALUE_UP-1] = png_read_filter_row_up_neon; + + if (bpp == 3) + { + pp->read_filter[PNG_FILTER_VALUE_SUB-1] = png_read_filter_row_sub3_neon; + pp->read_filter[PNG_FILTER_VALUE_AVG-1] = png_read_filter_row_avg3_neon; + pp->read_filter[PNG_FILTER_VALUE_PAETH-1] = + png_read_filter_row_paeth3_neon; + } + + else if (bpp == 4) + { + pp->read_filter[PNG_FILTER_VALUE_SUB-1] = png_read_filter_row_sub4_neon; + pp->read_filter[PNG_FILTER_VALUE_AVG-1] = png_read_filter_row_avg4_neon; + pp->read_filter[PNG_FILTER_VALUE_PAETH-1] = + png_read_filter_row_paeth4_neon; + } +} +#endif /* PNG_ARM_NEON_OPT > 0 */ +#endif /* READ */ |