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Diffstat (limited to 'third_party/libpng16/intel/intel_init.c')
-rw-r--r--third_party/libpng16/intel/intel_init.c53
1 files changed, 53 insertions, 0 deletions
diff --git a/third_party/libpng16/intel/intel_init.c b/third_party/libpng16/intel/intel_init.c
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+++ b/third_party/libpng16/intel/intel_init.c
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+
+/* intel_init.c - SSE2 optimized filter functions
+ *
+ * Copyright (c) 2016-2017 Glenn Randers-Pehrson
+ * Written by Mike Klein and Matt Sarett, Google, Inc.
+ * Derived from arm/arm_init.c
+ *
+ * Last changed in libpng 1.6.29 [March 16, 2017]
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ */
+
+#include "../pngpriv.h"
+
+#ifdef PNG_READ_SUPPORTED
+#if PNG_INTEL_SSE_IMPLEMENTATION > 0
+
+void
+png_init_filter_functions_sse2(png_structp pp, unsigned int bpp)
+{
+ /* The techniques used to implement each of these filters in SSE operate on
+ * one pixel at a time.
+ * So they generally speed up 3bpp images about 3x, 4bpp images about 4x.
+ * They can scale up to 6 and 8 bpp images and down to 2 bpp images,
+ * but they'd not likely have any benefit for 1bpp images.
+ * Most of these can be implemented using only MMX and 64-bit registers,
+ * but they end up a bit slower than using the equally-ubiquitous SSE2.
+ */
+ png_debug(1, "in png_init_filter_functions_sse2");
+ if (bpp == 3)
+ {
+ pp->read_filter[PNG_FILTER_VALUE_SUB-1] = png_read_filter_row_sub3_sse2;
+ pp->read_filter[PNG_FILTER_VALUE_AVG-1] = png_read_filter_row_avg3_sse2;
+ pp->read_filter[PNG_FILTER_VALUE_PAETH-1] =
+ png_read_filter_row_paeth3_sse2;
+ }
+ else if (bpp == 4)
+ {
+ pp->read_filter[PNG_FILTER_VALUE_SUB-1] = png_read_filter_row_sub4_sse2;
+ pp->read_filter[PNG_FILTER_VALUE_AVG-1] = png_read_filter_row_avg4_sse2;
+ pp->read_filter[PNG_FILTER_VALUE_PAETH-1] =
+ png_read_filter_row_paeth4_sse2;
+ }
+
+ /* No need optimize PNG_FILTER_VALUE_UP. The compiler should
+ * autovectorize.
+ */
+}
+
+#endif /* PNG_INTEL_SSE_IMPLEMENTATION > 0 */
+#endif /* PNG_READ_SUPPORTED */