Optimize implementation of Math.floor a little by special casing...

src/jump-target.h

 // Copyright 2008 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 94 matching lines @@
     return !is_bound() && reaching_frames_.is_empty();
   }
 
   // Emit a jump to the target.  There must be a current frame at the
   // jump and there will be no current frame after the jump.
   virtual void Jump();
   virtual void Jump(Result* arg);
 
   // Emit a conditional branch to the target.  There must be a current
   // frame at the branch.  The current frame will fall through to the
-  // code after the branch.
+  // code after the branch.  The arg is a result that is live both at
+  // the target and the fall-through.
   virtual void Branch(Condition cc, Hint hint = no_hint);
   virtual void Branch(Condition cc, Result* arg, Hint hint = no_hint);
 
   // Bind a jump target.  If there is no current frame at the binding
   // site, there must be at least one frame reaching via a forward
   // jump.
   virtual void Bind();
   virtual void Bind(Result* arg);
 
   // Emit a call to a jump target.  There must be a current frame at
@@ skipping 144 matching lines @@
   bool is_shadowing_;
 #endif
 
   DISALLOW_COPY_AND_ASSIGN(ShadowTarget);
 };
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_JUMP_TARGET_H_