note 14923 deleted from language.operators.assignment by jimw
| From: | jimw@php.net | Date: | Mon, 29 Oct 2001 00:51:06 +0000 |
| Subject: | note 14923 deleted from language.operators.assignment by jimw | ||
| References: | 1 | Groups: | php.notes |
| Request: | Send a blank email to php-notes+get-19538@lists.php.net to get a copy of this message | ||
$u -= $v is noticeably faster than $u = $u - $v. We have tested it three times for each situation
with the following code snippet:
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function gcd($u, $v) {
do {
if ($u < $v) {
$t = $v;
$v = $u;
$u = $t;
}
$u -= $v;
// $u = $u - $v;
} while ($u > 0);
return $v;
}
list($msec, $sec) = split(" ", microtime());
$time1 = $sec + $msec;
for ($i=0; $i<10000; $i++) {
gcd($u, $v);
}
list($msec, $sec) = split(" ", microtime());
$time2 = $sec + $msec;
echo $time2 - $time1;
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Execution time is about 15.5 secs on a Celeron 333 for $u -= $v, and 16.7 secs for $u = $u - $v.