ios fixes

src/core/SkPoint.cpp

Index: src/core/SkPoint.cpp
diff --git a/src/core/SkPoint.cpp b/src/core/SkPoint.cpp
index 719ee54b225ae72e57ee6752ab22a107178adc66..70406f1e123346fd2ac6bbc6a8bc4069afaf6440 100644
--- a/src/core/SkPoint.cpp
+++ b/src/core/SkPoint.cpp
@@ -168,7 +168,17 @@ bool SkPoint::setLength(float x, float y, float length) {
         // divide by inf. and return (0,0) vector.
         double xx = x;
         double yy = y;
+    #ifdef SK_FAST_UNDERFLOW_BEHAVIOR
+        // The iOS ARM processor discards small denormalized numbers to go faster.

[reed1, 2014/07/10 21:40:05]

I think this comment belongs in SkMathPriv.h or whereever we define this symbol.

That said, I know you took my suggested name, but seeing it now I'm not sure its
a good encapsulation of the behavior/difference, but I'll leave that to you.

[caryclark, 2014/07/11 12:57:19]

Done.

+        // Casting this to a float would cause the scale to go to zero. Keeping it
+        // as a double for the multipy keeps the scale non-zero.
+        double dscale = length / sqrt(xx * xx + yy * yy);
+        fX = x * dscale;
+        fY = y * dscale;
+        return true;
+    #else
         scale = (float)(length / sqrt(xx * xx + yy * yy));
+    #endif
     }
     fX = x * scale;
     fY = y * scale;