I feel like my clang is especially sensitive to unused variables.

src/core/SkMatrix.cpp

Index: src/core/SkMatrix.cpp
diff --git a/src/core/SkMatrix.cpp b/src/core/SkMatrix.cpp
index a6405190e09cb17758493a075738f12f9f12200b..3caf51a0cfa89eed47cc7815c21277aaad7a0352 100644
--- a/src/core/SkMatrix.cpp
+++ b/src/core/SkMatrix.cpp
@@ -48,13 +48,16 @@ enum {
 
 #ifdef SK_SCALAR_IS_FLOAT
     static const int32_t kScalar1Int = 0x3f800000;
-    static const int32_t kPersp1Int  = 0x3f800000;
 #else
     #define scalarAsInt(x)  (x)
     static const int32_t kScalar1Int = (1 << 16);
     static const int32_t kPersp1Int  = (1 << 30);
 #endif
 
+#ifdef SK_SCALAR_SLOW_COMPARES
+    static const int32_t kPersp1Int  = 0x3f800000;
+#endif
+
 uint8_t SkMatrix::computePerspectiveTypeMask() const {
 #ifdef SK_SCALAR_SLOW_COMPARES
     if (SkScalarAs2sCompliment(fMat[kMPersp0]) |