remove unnecessary copies

src/core/SkLinearBitmapPipeline.cpp

 /*
  * Copyright 2016 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkLinearBitmapPipeline.h"
 #include "SkPM4f.h"
 
@@ skipping 115 matching lines @@
 //                      point lists for processing.
 template<typename Strategy, typename Next>
 class PointProcessor final : public SkLinearBitmapPipeline::PointProcessorInterface {
 public:
     template <typename... Args>
     PointProcessor(Next* next, Args&&... args)
         : fNext{next}
         , fStrategy{std::forward<Args>(args)...}{ }
 
     void VECTORCALL pointListFew(int n, Sk4f xs, Sk4f ys) override {
-        Sk4f newXs = xs;
-        Sk4f newYs = ys;
-        fStrategy.processPoints(&newXs, &newYs);
-        fNext->pointListFew(n, newXs, newYs);
+        fStrategy.processPoints(&xs, &ys);
+        fNext->pointListFew(n, xs, ys);
     }
 
     void VECTORCALL pointList4(Sk4f xs, Sk4f ys) override {
-        Sk4f newXs = xs;
-        Sk4f newYs = ys;
-        fStrategy.processPoints(&newXs, &newYs);
-        fNext->pointList4(newXs, newYs);
+        fStrategy.processPoints(&xs, &ys);
+        fNext->pointList4(xs, ys);
     }
 
     void pointSpan(SkPoint start, SkScalar length, int count) override {
         if (!fStrategy.maybeProcessSpan(start, length, count, fNext)) {
             span_fallback(start, length, count, this);
         }
     }
 
 private:
     Next* const fNext;
     Strategy fStrategy;
 };
 
 // See PointProcessor for responsibilities of Strategy.
 template<typename Strategy, typename Next>
 class BilerpProcessor final : public SkLinearBitmapPipeline::BilerpProcessorInterface  {
 public:
     template <typename... Args>
     BilerpProcessor(Next* next, Args&&... args)
         : fNext{next}
         , fStrategy{std::forward<Args>(args)...}{ }
 
     void VECTORCALL pointListFew(int n, Sk4f xs, Sk4f ys) override {
-        Sk4f newXs = xs;
-        Sk4f newYs = ys;
-        fStrategy.processPoints(&newXs, &newYs);
-        fNext->pointListFew(n, newXs, newYs);
+        fStrategy.processPoints(&xs, &ys);
+        fNext->pointListFew(n, xs, ys);
     }
 
     void VECTORCALL pointList4(Sk4f xs, Sk4f ys) override {
-        Sk4f newXs = xs;
-        Sk4f newYs = ys;
-        fStrategy.processPoints(&newXs, &newYs);
-        fNext->pointList4(newXs, newYs);
+        fStrategy.processPoints(&xs, &ys);
+        fNext->pointList4(xs, ys);
     }
 
     void VECTORCALL bilerpList(Sk4f xs, Sk4f ys) override {
-        Sk4f newXs = xs;
-        Sk4f newYs = ys;
-        fStrategy.processPoints(&newXs, &newYs);
-        fNext->bilerpList(newXs, newYs);
+        fStrategy.processPoints(&xs, &ys);
+        fNext->bilerpList(xs, ys);
     }
 
     void pointSpan(SkPoint start, SkScalar length, int count) override {
         if (!fStrategy.maybeProcessSpan(start, length, count, fNext)) {
             span_fallback(start, length, count, this);
         }
     }
 
 private:
     Next* const fNext;
     Strategy fStrategy;
 };
 
 class SkippedStage final : public SkLinearBitmapPipeline::BilerpProcessorInterface {
     void VECTORCALL pointListFew(int n, Sk4f xs, Sk4f ys) override {
         SkFAIL("Skipped stage.");
     }
-    void VECTORCALL pointList4(Sk4f Xs, Sk4f Ys) override {
+    void VECTORCALL pointList4(Sk4f xs, Sk4f ys) override {
         SkFAIL("Skipped stage.");
     }
     void VECTORCALL bilerpList(Sk4f xs, Sk4f ys) override {
         SkFAIL("Skipped stage.");
     }
     void pointSpan(SkPoint start, SkScalar length, int count) override {
         SkFAIL("Skipped stage.");
     }
 };
 
@@ skipping 495 matching lines @@
     if (count == 1) {
         fFirstStage->pointListFew(1, Sk4f{x + 0.5f}, Sk4f{y + 0.5f});
     } else {
         // The count and length arguments start out in a precise relation in order to keep the
         // math correct through the different stages. Count is the number of pixel to produce.
         // Since the code samples at pixel centers, length is the distance from the center of the
         // first pixel to the center of the last pixel. This implies that length is count-1.
         fFirstStage->pointSpan(SkPoint{x + 0.5f, y + 0.5f}, count - 1, count);
     }
 }