[v8-dev] Optimise Math.floor(x/y) to use integer division for specific divisor....

src/frames.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 1341 matching lines @@
     entry->safepoint_entry.Reset();
     entry->inner_pointer = inner_pointer;
   }
   return entry;
 }
 
 
 // -------------------------------------------------------------------------
 
 int NumRegs(RegList reglist) {
-  int n = 0;
-  while (reglist != 0) {
-    n++;
-    reglist &= reglist - 1;  // clear one bit
-  }
-  return n;
+  return CompilerIntrinsics::CountSetBits(reglist);
 }
 
 
 struct JSCallerSavedCodeData {
   JSCallerSavedCodeData() {
     int i = 0;
     for (int r = 0; r < kNumRegs; r++)
       if ((kJSCallerSaved & (1 << r)) != 0)
         reg_code[i++] = r;
 
@@ skipping 42 matching lines @@
   ZoneList<StackFrame*> list(10);
   for (StackFrameIterator it; !it.done(); it.Advance()) {
     StackFrame* frame = AllocateFrameCopy(it.frame());
     list.Add(frame);
   }
   return list.ToVector();
 }
 
 
 } }  // namespace v8::internal