try to speed-up maprect + round2i + contains

include/core/SkRect.h

Index: include/core/SkRect.h
diff --git a/include/core/SkRect.h b/include/core/SkRect.h
index 39cbb330f82b207cd6a508570fe41f1372353590..67080d115acb564f40b205e4dd5a0fd68e2d0724 100644
--- a/include/core/SkRect.h
+++ b/include/core/SkRect.h
@@ -10,6 +10,7 @@
 
 #include "SkPoint.h"
 #include "SkSize.h"
+#include "../private/SkNx.h"
 
 struct SkRect;
 
@@ -869,7 +870,20 @@ public:
         this->roundOut(&ir);
         return ir;
     }
-    
+
+    SkIRect round2i() const {
+        SkIRect dst;
+        Sk4s rd = (Sk4s::Load(&fLeft) + Sk4s(0.5)).floor();
+        SkNx_cast<int32_t>(rd).store(&dst.fLeft);

[mtklein, 2016/07/11 19:43:18]

SkIRect dst;
SkNx_cast<int32_t>(this->round2s()).store(&dst.fLeft);
return dst;

?

[reed1, 2016/07/11 19:46:31]

round2s returns SkRect, not Sk4s

+        return dst;
+    }
+
+    SkRect round2s() const {
+        SkRect dst;
+        (Sk4s::Load(&fLeft) + Sk4s(0.5)).floor().store(&dst.fLeft);

[mtklein, 2016/07/11 19:43:18]

It's okay if you like writing this out, but you can also write

(Sk4s::Load(&fLeft) + 0.5f)

+        return dst;
+    }
+
     /**
      *  Swap top/bottom or left/right if there are flipped (i.e. if width()
      *  or height() would have returned a negative value.) This should be called