Re^2: Macro in perl code?

I don't know if there is any real value in benchmarking this because it may change from different vesion of Perl but the results would indicate that using shift is faster.

#!/usr/bin/env perl

use strict; use warnings;
use Benchmark qw/ cmpthese /;
cmpthese(10000000, {
        shift => sub { my $volume = shift; my $message = shift; },
        inline => sub { my ($volume, $message) = @_ } 
        }
);
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And the output is -

bruce:0:~/tmp $ ./p.pl
            Rate inline  shift
inline 3300330/s     --   -29%
shift  4629630/s    40%     --
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Re^3: Macro in perl code? by andreas1234567 (Vicar) on Oct 16, 2007 at 19:20 UTC
Adding some overhead in the subroutine being called, the difference (if any) between the two approaches disappears altogether: $ cat 645237.pl use strict; use warnings; use Benchmark qw/ cmpthese /; use List::Util qw/ sum /; sub foo { my ($volume, $message) = @_; my @foo = ($volume .. $message); @foo = map { $_ 2 } @foo; return sum(@foo); } sub bar { my $volume = shift; my $message = shift; my @foo = ($volume .. $message); @foo = map { $_ 2 } @foo; return sum(@foo); } cmpthese(100_000, { shift => sub { foo(1, 100) }, inline => sub { bar(1, 100) }, } ); $ perl 645237.pl Rate inline shift inline 8396/s -- -0% shift 8403/s 0% -- [download] If your Benchmark shows your computer is able to perform an operation 3 million times pr. second, that's equivalent of a 1000 m2 highway sign saying: Don't optimize! Update: Changed code to supply arguments to functions as pointed out by bruceb3. -- Andreas	[reply] [d/l]
Re^4: Macro in perl code? by bruceb3 (Pilgrim) on Oct 16, 2007 at 21:27 UTC
What is interesting is that the code that you benchmarked and the code that I benchmarked, doesn't actually supply arguments to the either function, which really is the point after all. Changing the cmpthese call to; `cmpthese(100_000, { shift => sub { foo(1, "foo") }, inline => sub { bar(1, "bar") } });` [download] The results are the same for either method; `bruce:0:~/tmp $ ./535237.pl Rate shift inline shift 15456/s -- -0% inline 15528/s 0% --` [download]	[reply] [d/l] [select]