speed up rgn building by inlining memcmp for 32bit values

src/core/SkRegion_path.cpp

-
 /*
  * Copyright 2006 The Android Open Source Project
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
-
 #include "SkRegionPriv.h"
 #include "SkBlitter.h"
 #include "SkScan.h"
 #include "SkTDArray.h"
 #include "SkPath.h"
 
+// The rgnbuilder caller *seems* to pass short counts, possible often seens early failure, so
+// we may not want to promote this to a "std" routine just yet.
+static bool sk_memeq32(const int32_t* SK_RESTRICT a, const int32_t* SK_RESTRICT b, int count) {
+    for (int i = 0; i < count; ++i) {
+        if (a[i] != b[i]) {
+            return false;
+        }
+    }
+    return true;
+}
+
 class SkRgnBuilder : public SkBlitter {
 public:
     SkRgnBuilder();
     virtual ~SkRgnBuilder();
 
     // returns true if it could allocate the working storage needed
     bool init(int maxHeight, int maxTransitions, bool pathIsInverse);
 
     void done() {
         if (fCurrScanline != NULL) {
@@ skipping 54 matching lines @@
     //  points at next avialable x[] in fCurrScanline
     SkRegion::RunType*  fCurrXPtr;
     SkRegion::RunType   fTop;           // first Y value
 
     int fStorageCount;
 
     bool collapsWithPrev() {
         if (fPrevScanline != NULL &&
             fPrevScanline->fLastY + 1 == fCurrScanline->fLastY &&
             fPrevScanline->fXCount == fCurrScanline->fXCount &&
-            !memcmp(fPrevScanline->firstX(),
-                    fCurrScanline->firstX(),
-                    fCurrScanline->fXCount * sizeof(SkRegion::RunType)))
+            sk_memeq32(fPrevScanline->firstX(), fCurrScanline->firstX(), fCurrScanline->fXCount))
         {
             // update the height of fPrevScanline
             fPrevScanline->fLastY = fCurrScanline->fLastY;
             return true;
         }
         return false;
     }
 };
 
 SkRgnBuilder::SkRgnBuilder()
@@ skipping 408 matching lines @@
 #endif
 
     path->incReserve(count << 1);
     do {
         SkASSERT(count > 1);
         count -= extract_path(start, stop, path);
     } while (count > 0);
 
     return true;
 }