C:\>perl -MO=Deparse -we "$a = 'doit'; print \"hi\n\" if $a eq 'doit'"
$a = 'doit';
print "hi\n" if $a eq 'doit';
-e syntax OK

C:\>perl -MO=Deparse -we "$a = 'doit'; if ($a eq 'doit'){print \"hi\n\"}"
$a = 'doit';
if ($a eq 'doit') {
    print "hi\n";
}
-e syntax OK

##</code><code>##

#!perl -w
use strict;
use Benchmark;

sub Time
{
  use vars qw( $clause );
  $clause = shift;
  timethese( -5, {
    normal  => sub { my $i = 0; if( $clause ) { ++$i } },
    reverse => sub { my $i = 0; ++$i if $clause },
    }
  );
}

Time(1);
Time(0);

__END__
Output:

Benchmark: running normal, reverse, each for at least 5 CPU seconds...
    normal:  6 wallclock secs ( 5.00 usr +  0.00 sys =  5.00 CPU) @ 975640.40/s (n=4878202)
   reverse:  5 wallclock secs ( 5.21 usr +  0.00 sys =  5.21 CPU) @ 1003193.28/s (n=5226637)
Benchmark: running normal, reverse, each for at least 5 CPU seconds...
    normal:  5 wallclock secs ( 5.27 usr +  0.00 sys =  5.27 CPU) @ 1565443.64/s (n=8249888)
   reverse:  4 wallclock secs ( 5.11 usr +  0.00 sys =  5.11 CPU) @ 1585628.38/s (n=8102561)