Rewriting MatrixConvolution image filter with SSE and AVX2

gyp/opts.gypi

 # Copyright 2015 Google Inc.
 #
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 {
         'none_sources': [
             '<(skia_src_path)/opts/SkBitmapProcState_opts_none.cpp',
             '<(skia_src_path)/opts/SkBlitMask_opts_none.cpp',
             '<(skia_src_path)/opts/SkBlitRow_opts_none.cpp',
         ],
@@ skipping 25 matching lines @@
             '<(skia_src_path)/opts/SkBitmapProcState_opts_mips_dsp.cpp',
             '<(skia_src_path)/opts/SkBlitMask_opts_none.cpp',
             '<(skia_src_path)/opts/SkBlitRow_opts_mips_dsp.cpp',
         ],
 
         'sse2_sources': [
             '<(skia_src_path)/opts/SkBitmapFilter_opts_SSE2.cpp',
             '<(skia_src_path)/opts/SkBitmapProcState_opts_SSE2.cpp',
             '<(skia_src_path)/opts/SkBlitRow_opts_SSE2.cpp',
             '<(skia_src_path)/opts/opts_check_x86.cpp',
+            '<(skia_src_path)/opts/SkOpts_sse_sse2.cpp',

[Stephen White, 2016/04/12 20:01:58]

It seems strange to add a file just for this one function. Mike would know
better than I the current way to do these integrations, in Skia, but perhaps the
SSE path should just be integrated directly into
SkMatrixConvolutionImageFilter.cpp (protected by a compile-time flag), and we
just switch between the SSE-or-not version and the AVX2 version at runtime?

+            '<(skia_src_path)/opts/SkMatrixConvolutionImageFilter_opts_SSE.cpp',
         ],
         'ssse3_sources': [
             '<(skia_src_path)/opts/SkBitmapProcState_opts_SSSE3.cpp',
             '<(skia_src_path)/opts/SkOpts_ssse3.cpp',
         ],
         'sse41_sources': [
             '<(skia_src_path)/opts/SkOpts_sse41.cpp',
         ],
         # These targets are empty, but XCode doesn't like that, so add an empty file to each.
         'sse42_sources': [
             '<(skia_src_path)/core/SkForceCPlusPlusLinking.cpp',
         ],
         'avx_sources': [
             '<(skia_src_path)/core/SkForceCPlusPlusLinking.cpp',
         ],
         'avx2_sources': [
             '<(skia_src_path)/core/SkForceCPlusPlusLinking.cpp',
+            '<(skia_src_path)/opts/SkMatrixConvolutionImageFilter_opts_AVX2.cpp',
+            '<(skia_src_path)/opts/SkOpts_avx2.cpp',
         ],
 }