int abs.js

var _abs = Math.abs;

_speedTest(
  [
    function(n)
    {
      var a = 0; 
      var i = n; while(i--)
      {
        a = (25173*a + 13849)&0xffff;
        a -= 0x7fff;
        if(a < 0) a = -a;
      }    
    },
    function(n)
    {
      var a = 0; 
      var i = n; while(i--)
      {
        a = (25173*a + 13849)&0xffff;
        a -= 0x7fff;
        a = (a^(a >> 31)) - (a >> 31);
      }    
    },
    function(n)
    {
      var a = 0; 
      var i = n; while(i--)
      {
        a = (25173*a + 13849)&0xffff;
        a -= 0x7fff;
        a = _abs(a);
      }    
    }
  ],
  100000000
);

/*
ie7 300000
0: 330 ms
1: 371 ms
2: 1021 ms

chrome5 10000000
0: 522 ms
1: 444 ms
2: 780 ms

opera10.60 20000000
0: 837 ms
1: 666 ms
2: 1320 ms

ff3.6 10000000
0: 7496 ms
1: 9101 ms
2: 8357 ms
*/