note
sgifford
They seem to be about the same. <code>shift</code> comes out slightly ahead in this test, perhaps because it simplifies the loop.
<code>
#!/usr/bin/perl
use warnings;
use strict;
use Benchmark;
timethese(1_000_000, {
'use_shift' => sub { sub_with_shift(0..9) },
'use_list' => sub { sub_with_list(0..9) },
'use_direct' => sub { sub_with_direct(0..9) },
});
sub sub_with_shift
{
my $sum = 0;
while (@_)
{
$sum += shift;
}
$sum;
}
sub sub_with_list
{
my(@a)=@_;
my $sum = 0;
$sum += $_
for @a;
$sum;
}
sub sub_with_direct
{
my $sum = 0;
$sum += $_
for @_;
$sum;
}
</code>
<pre>
Benchmark: timing 1000000 iterations of use_direct, use_list, use_shift...
use_direct: 7 wallclock secs ( 6.48 usr + -0.01 sys = 6.47 CPU) @ 154559.51/s (n=1000000)
use_list: 10 wallclock secs ( 9.85 usr + 0.06 sys = 9.91 CPU) @ 100908.17/s (n=1000000)
use_shift: 6 wallclock secs ( 6.48 usr + 0.01 sys = 6.49 CPU) @ 154083.20/s (n=1000000)
</pre>
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<br>
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<i>[http://www.suspectclass.com/~sgifford/|sgifford's Web page]</i>
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