I am always qualifying the calls with an "if" to avoid the cost of a call/return pair. Is there anything else I can do to eliminate more of the performance overhead? A better method? BTW, I want the debug calls to be an execution time option. The program has a usage with a "-debug" option. Thanks!

Having a -debug option doesn't mean you need to do anything at execution time. You can check options in a BEGIN block and set a constant that controls whether debug statements will be optimized away or not:

$ cat deb.pl
#!/usr/bin/perl

use strict;
use warnings;
use Getopt::Long;

my $FOO_DEBUG_MODE;
BEGIN { GetOptions("debug", \$FOO_DEBUG_MODE) }
use constant FOO_DEBUG_MODE => $FOO_DEBUG_MODE;

print "debug statment\n" if FOO_DEBUG_MODE;
print "done!\n";
[download]

Without the -debug option, the print and if are optimized away to be just an empty statement:

$ perl -MO=Deparse deb.pl
use Getopt::Long;
BEGIN {${^WARNING_BITS} = "UUUUUUUUUUUU"}
use strict 'refs';
my $FOO_DEBUG_MODE;
sub BEGIN {
    GetOptions 'debug', \$FOO_DEBUG_MODE;
}
use constant ('FOO_DEBUG_MODE', $FOO_DEBUG_MODE);
'???';
print "done!\n";
deb.pl syntax OK
[download]

With -debug, the if is optimized away leaving just the debug call:

$ perl -MO=Deparse deb.pl -debug
use Getopt::Long;
BEGIN {${^WARNING_BITS} = "UUUUUUUUUUUU"}
use strict 'refs';
my $FOO_DEBUG_MODE;
sub BEGIN {
    GetOptions 'debug', \$FOO_DEBUG_MODE;
}
use constant ('FOO_DEBUG_MODE', $FOO_DEBUG_MODE);
print "debug statment\n";
print "done!\n";
deb.pl syntax OK
[download]

---

---

• Are you posting in the right place? Check out Where do I post X? to know for sure.
• Posts may use any of the Perl Monks Approved HTML tags. Currently these include the following:

  <code> <a> <b> <big> <blockquote> <br /> <dd> <dl> <dt> <em> <font> <h1> <h2> <h3> <h4> <h5> <h6> <hr /> <i> <li> <nbsp> <ol> <p> <small> <strike> <strong> <sub> <sup> <table> <td> <th> <tr> <tt> <u> <ul>

• Snippets of code should be wrapped in <code> tags not <pre> tags. In fact, <pre> tags should generally be avoided. If they must be used, extreme care should be taken to ensure that their contents do not have long lines (<70 chars), in order to prevent horizontal scrolling (and possible janitor intervention).
• Want more info? How to link or How to display code and escape characters are good places to start.