Code's more readable when SkPMFloat is an Sk4f.

src/effects/SkColorMatrixFilter.cpp

 /*
  * Copyright 2011 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkColorMatrixFilter.h"
 #include "SkColorMatrix.h"
 #include "SkColorPriv.h"
@@ skipping 251 matching lines @@
 #ifdef SK_DEBUG
     SkPMFloat pmf(pm);
     SkASSERT(pmf.isValid());
 #endif
 
     return pm;
 }
 
 static Sk4f unpremul(const SkPMFloat& pm) {
     float scale = 255 / pm.a(); // candidate for fast/approx invert?
-    return Sk4f(pm) * Sk4f(scale, scale, scale, 1);
+    return pm * Sk4f(scale, scale, scale, 1);
 }
 
 static Sk4f clamp_0_255(const Sk4f& value) {
     return Sk4f::Max(Sk4f::Min(value, Sk4f(255)), Sk4f(0));
 }
 
 void SkColorMatrixFilter::filterSpan(const SkPMColor src[], int count, SkPMColor dst[]) const {
     Proc proc = fProc;
     if (NULL == proc) {
         if (src != dst) {
@@ skipping 294 matching lines @@
     str->append("matrix: (");
     for (int i = 0; i < 20; ++i) {
         str->appendScalar(fMatrix.fMat[i]);
         if (i < 19) {
             str->append(", ");
         }
     }
     str->append(")");
 }
 #endif