Avoid map transitions and multiple backing arrays for builtin prototypes...

src/math.js

 // Copyright 2006-2008 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 166 matching lines @@
   if (!IS_NUMBER(x)) x = ToNumber(x);
   return %Math_tan(x);
 }
 
 
 // -------------------------------------------------------------------
 
 function SetupMath() {
   // Setup math constants.
   // ECMA-262, section 15.8.1.1.
+  %OptimizeObjectForAddingMultipleProperties($Math, 26);
   %SetProperty($Math,
                "E",
                2.7182818284590452354,
                DONT_ENUM |  DONT_DELETE | READ_ONLY);
   // ECMA-262, section 15.8.1.2.
   %SetProperty($Math,
                "LN10",
                2.302585092994046,
                DONT_ENUM |  DONT_DELETE | READ_ONLY);
   // ECMA-262, section 15.8.1.3.
@@ skipping 42 matching lines @@
     "tan", MathTan,
     "atan2", MathAtan2,
     "pow", MathPow,
     "max", MathMax,
     "min", MathMin
   ));
 };
 
 
 SetupMath();