SSE2 implementation of RGBA box blurs. This yields ~2X perf improvement on

src/opts/opts_check_SSE2.cpp

 /*
  * Copyright 2009 The Android Open Source Project
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkBitmapProcState_opts_SSE2.h"
 #include "SkBitmapProcState_opts_SSSE3.h"
 #include "SkBitmapFilter_opts_SSE2.h"
 #include "SkBlitMask.h"
 #include "SkBlitRow.h"
 #include "SkBlitRect_opts_SSE2.h"
 #include "SkBlitRow_opts_SSE2.h"
+#include "SkBlurImage_opts_SSE2.h"
 #include "SkUtils_opts_SSE2.h"
 #include "SkUtils.h"
 #include "SkMorphology_opts.h"
 #include "SkMorphology_opts_SSE2.h"
 
 #include "SkRTConf.h"
 
 #if defined(_MSC_VER) && defined(_WIN64)
 #include <intrin.h>
 #endif
@@ skipping 236 matching lines @@
             return SkDilateY_SSE2;
         case kErodeX_SkMorphologyProcType:
             return SkErodeX_SSE2;
         case kErodeY_SkMorphologyProcType:
             return SkErodeY_SSE2;
         default:
             return NULL;
     }
 }
 
+SkBoxBlurProc SkBoxBlurGetPlatformProc(SkBlurDirection srcDirection, SkBlurDirection dstDirection) {
+#ifdef SK_DISABLE_BLUR_DIVISION_OPTIMIZATION
+    return NULL;

[mtklein, 2013/11/08 02:11:03]

Line counter in me cries out for:

#ifndef SK_DISABLE_THING
...
#endif
return NULL;

+#else
+    if (!cachedHasSSE2()) {
+        return NULL;
+    }
+    if (srcDirection == kX_BlurDirection) {
+        if (dstDirection == kX_BlurDirection) {
+            return SkBoxBlur_SSE2<kX_BlurDirection, kX_BlurDirection>;
+        } else if (dstDirection == kY_BlurDirection) {
+            return SkBoxBlur_SSE2<kX_BlurDirection, kY_BlurDirection>;
+        }
+    } else {
+        if (dstDirection == kX_BlurDirection) {
+            return SkBoxBlur_SSE2<kY_BlurDirection, kX_BlurDirection>;
+        } else if (dstDirection == kY_BlurDirection) {
+            return SkBoxBlur_SSE2<kY_BlurDirection, kY_BlurDirection>;
+        }
+    }
+    return NULL;
+#endif
+}
+
 SkBlitRow::ColorRectProc PlatformColorRectProcFactory(); // suppress warning
 
 SkBlitRow::ColorRectProc PlatformColorRectProcFactory() {
     if (cachedHasSSE2()) {
         return ColorRect32_SSE2;
     } else {
         return NULL;
     }
 }