pow() showing odd long/float boundary case characteristics
| From: | Rasmus Lerdorf | Date: | Tue, 13 Nov 2001 13:13:57 +0000 |
| Subject: | pow() showing odd long/float boundary case characteristics | ||
| Groups: | php.dev | ||
| Request: | Send a blank email to php-dev+get-70344@lists.php.net to get a copy of this message | ||
The pow() regression test is failing due to this strange characteristic:
<?
$a[] = 2147483646;
$a[] = pow(2147483646,1);
$a[] = 2147483647;
$a[] = pow(2147483647,1);
$a[] = 2147483648;
$a[] = pow(2147483648,1);
var_dump($a);
?>
Produces:
array(6) {
[0]=> int(2147483646)
[1]=> int(2147483646)
[2]=> int(2147483647)
[3]=> float(2147483647)
[4]=> float(2147483648)
[5]=> float(2147483648)
}
ie. pow(2147483647,1) returns a float where one would expect it to return
an int. Off by one error somewhere?
Same thing happens on the negative boundary.
-Rasmus