Optimization for parsing integers of limited length (in digits).

test/mjsunit/parse-int-float.js

 // 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 29 matching lines @@
 
 assertEquals(0x12, parseInt('0x12'));
 assertEquals(0x12, parseInt('0x12', 16));
 assertEquals(0x12, parseInt('0x12', 16.1));
 assertEquals(0x12, parseInt('0x12', NaN));
 
 assertEquals(12, parseInt('12aaa'));
 
 assertEquals(0.1, parseFloat('0.1'));
 assertEquals(0.1, parseFloat('0.1aaa'));
+assertEquals(0, parseFloat('0aaa'));
 assertEquals(0, parseFloat('0x12'));
 assertEquals(77, parseFloat('077'));
 
 
 var i;
 var y = 10;
 
 for (i = 1; i < 21; i++) {
   var x = eval("1.2e" + i);
   assertEquals(Math.floor(x), parseInt(x));
@@ skipping 16 matching lines @@
 
 assertTrue(isNaN(parseInt(0/0)));
 assertTrue(isNaN(parseInt(1/0)), "parseInt Infinity");
 assertTrue(isNaN(parseInt(-1/0)), "parseInt -Infinity");
 
 assertTrue(isNaN(parseFloat(0/0)));
 assertEquals(Infinity, parseFloat(1/0), "parseFloat Infinity");
 assertEquals(-Infinity, parseFloat(-1/0), "parseFloat -Infinity");