Re: Re^8: How about 450% greater performance

I'd like to see any Benchmark that could show that using that technique you describe could provide measurable performance gains.

#! perl -w
use strict;
use Benchmark qw(cmpthese);

sub parent {
    return ++$_[$#_]; # minimal use of entire passed array.
}

sub child1 {
    my ($self, @rest) = @_;
    return parent(@rest);
}

sub child2 {
    my $self = shift;
    goto &parent;
}

print 'child1: ', child1( "fred", 1..1000 ), $/;
print 'child2: ', child2( "bill", 1..1000 ), $/;

cmpthese( 10000, {
    noShiftOrGoto    => sub { child1( "fred", 1..1000 ); },
    shiftAndGoto    => sub { child2( "bill", 1..1000 ); },
});

__DATA__
C:\test>196823
child1: 1001
child2: 1001
Benchmark: timing 10000 iterations of noShiftOrGoto, shiftAndGoto...
noShiftOrGoto: 33 wallclock secs (32.33 usr +  0.00 sys = 32.33 CPU) @
+ 309.35/s (n=10000)
shiftAndGoto:  6 wallclock secs ( 5.85 usr +  0.00 sys =  5.85 CPU) @ 
+1709.69/s (n=10000)
                Rate noShiftOrGoto  shiftAndGoto
noShiftOrGoto  309/s            --          -82%
shiftAndGoto  1710/s          453%            --

C:\test>
[download]

Well It's better than the Abottoire, but Yorkshire!

Comment on Re: Re^8: How about 450% greater performance Download Code

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Re^10: How About A Better Benchmark? by tadman (Prior) on Sep 11, 2002 at 01:36 UTC
That's not precisely a fair test. How about this? #!/usr/bin/perl use Benchmark 'cmpthese'; package Foo; sub new { my $class = shift; bless({@_}, $class); } sub foo { my ($self, @stuff) = @_; return map { $_.$_ } @stuff; } sub foo_pipe { my $self = shift; $self->foo(@_); } sub foo_my { my ($self,@stuff) = @_; $self->foo(@stuff); } sub foo_goto { goto &foo; } package main; my $foo = Foo->new(); my @stuff = 0..100; my @foo; cmpthese(500, { pipe => sub { $foo->foo_pipe(@foo=@stuff) }, goto => sub { $foo->foo_goto(@foo=@stuff) }, my => sub { $foo->foo_my(@foo=@stuff) }, }); [download] This actually uses the entire array. The difference is rather minor, easily buried by the subroutine overhead. `Benchmark: timing 5000 iterations of goto, my, pipe... goto: 3 wallclock secs ( 2.96 usr + 0.00 sys = 2.96 CPU) @ 16 +89.19/s (n=5000) my: 4 wallclock secs ( 3.18 usr + 0.01 sys = 3.19 CPU) @ 15 +67.40/s (n=5000) pipe: 3 wallclock secs ( 2.89 usr + 0.00 sys = 2.89 CPU) @ 17 +30.10/s (n=5000) Rate my goto pipe my 1567/s -- -7% -9% goto 1689/s 8% -- -2% pipe 1730/s 10% 2% --` [download]	[reply] [d/l] [select]

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Re^10: How About A Better Benchmark?
by tadman (Prior) on Sep 11, 2002 at 01:36 UTC

#!/usr/bin/perl

use Benchmark 'cmpthese';

package Foo;

sub new
{
        my $class = shift;
        bless({@_}, $class);
}

sub foo
{
        my ($self, @stuff) = @_;

        return map { $_.$_ } @stuff;
}

sub foo_pipe
{
        my $self = shift;
        $self->foo(@_);
}

sub foo_my
{
        my ($self,@stuff) = @_;
        $self->foo(@stuff);
}

sub foo_goto
{
        goto &foo;
}

package main;

my $foo = Foo->new();
my @stuff = 0..100;
my @foo;

cmpthese(500, {
        pipe => sub { $foo->foo_pipe(@foo=@stuff) },
        goto => sub { $foo->foo_goto(@foo=@stuff) },
        my   => sub { $foo->foo_my(@foo=@stuff) },
});
[download]

Benchmark: timing 5000 iterations of goto, my, pipe...
      goto:  3 wallclock secs ( 2.96 usr +  0.00 sys =  2.96 CPU) @ 16
+89.19/s (n=5000)
        my:  4 wallclock secs ( 3.18 usr +  0.01 sys =  3.19 CPU) @ 15
+67.40/s (n=5000)
      pipe:  3 wallclock secs ( 2.89 usr +  0.00 sys =  2.89 CPU) @ 17
+30.10/s (n=5000)
       Rate   my goto pipe
my   1567/s   --  -7%  -9%
goto 1689/s   8%   --  -2%
pipe 1730/s  10%   2%   --
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