js1_5/Regress/regress-211590.js

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 * The Original Code is JavaScript Engine testing utilities.
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 * Contributor(s): zack-weg@gmx.de
 *                 Bob Clary <bob@bclary.com>
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var gTestfile = 'regress-211590.js';
//-----------------------------------------------------------------------------
var BUGNUMBER = 211590;
var summary = 'Math.random should be random';
var actual = '';
var expect = 'between 48% and 52%';

printBugNumber(BUGNUMBER);
printStatus (summary);
 
var r = Math.random;
var c = Math.pow( 2, 53 );

var n = 10000;
var odd1 = 0;
var odd2 = 0;

for ( var i = 0; i < n; ++i )
{
  var v= r() * c;
  if ( v & 1 )
    ++odd1;
  if ( v - c + c & 1 )
    ++odd2;
}

odd1 *= 100 / n;
odd2 *= 100 / n;

if (odd1 >= 48 && odd1 <= 52)
{
  actual = expect;
}
else
{
  actual = ' is ' + odd1.toFixed(3);
}

reportCompare(expect, actual, summary);

if (odd2 >= 48 && odd2 <= 52)
{
  actual = expect;
}
else
{
  actual = ' is ' + odd2.toFixed(3);
}

reportCompare(expect, actual, summary);