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diff --git a/third_party/libpng16/arm/arm_init.c b/third_party/libpng16/arm/arm_init.c
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+
+/* 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 */