try to speed-up maprect + round2i + contains

src/core/SkMatrix.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 "SkFloatBits.h"
 #include "SkMatrix.h"
 #include "SkNx.h"
@@ skipping 1101 matching lines @@
     Sk4f rblt(ltrb[2], ltrb[3], ltrb[0], ltrb[1]);
     Sk4f min = Sk4f::Min(ltrb, rblt);
     Sk4f max = Sk4f::Max(ltrb, rblt);
     // We can extract either pair [0,1] or [2,3] from min and max and be correct, but on
     // ARM this sequence generates the fastest (a single instruction).
     SkRect dst;
     Sk4f(min[0], min[1], max[0], max[1]).store(&dst.fLeft);
     return dst;
 }
 
+SkRect SkMatrix::mapRectScaleTranslate(SkRect src) const {
+    SkASSERT(this->isScaleTranslate());
+    
+    SkScalar sx = fMat[kMScaleX];
+    SkScalar sy = fMat[kMScaleY];
+    SkScalar tx = fMat[kMTransX];
+    SkScalar ty = fMat[kMTransY];
+    Sk4f scale(sx, sy, sx, sy);
+    Sk4f trans(tx, ty, tx, ty);
+    
+    Sk4f ltrb = Sk4f::Load(&src.fLeft) * scale + trans;
+    // need to sort so we're not inverted
+    Sk4f rblt(ltrb[2], ltrb[3], ltrb[0], ltrb[1]);
+    Sk4f min = Sk4f::Min(ltrb, rblt);
+    Sk4f max = Sk4f::Max(ltrb, rblt);
+    // We can extract either pair [0,1] or [2,3] from min and max and be correct, but on
+    // ARM this sequence generates the fastest (a single instruction).
+    SkRect dst;
+    Sk4f(min[0], min[1], max[0], max[1]).store(&dst.fLeft);
+    return dst;
+}
+
 bool SkMatrix::mapRect(SkRect* dst, const SkRect& src) const {
     SkASSERT(dst);
 
     if (this->isScaleTranslate()) {
         *dst = this->mapRectScaleTranslate(src);
         return true;
     } else {
         SkPoint quad[4];
 
         src.toQuad(quad);
@@ skipping 746 matching lines @@
     const SkScalar m10 = -m01;
     const SkScalar m11 = m00;
     const SkScalar m12 = fTy;
 
     quad[0].set(m02, m12);
     quad[1].set(m00 * width + m02, m10 * width + m12);
     quad[2].set(m00 * width + m01 * height + m02, m10 * width + m11 * height + m12);
     quad[3].set(m01 * height + m02, m11 * height + m12);
 #endif
 }