> > > > Function calls in Perl are dead slow compared > > > > to compiled languages. > > > > > > Ok, so why is this? > > > > > > > Implementation and little optimization. > > > > Perl has a complex function calling mechanism, as > > it flattens argument lists by pushing elements onto > > the stack, records argument list length - the > > number of arguments are variable in length. > > Plus it keeps track of the call stack ... you can print out from > where you were called, from where your caller has been called and > so on. > > > Unlike many compiled languages, Perl does not > > inline short/frequently called functions - with > > the result that speed suffers. > > Well ... it does. But it only inlines the constant functions that have > been seen before they were used. And they have to be specified as > having no parameters! >
Useful :P Okay... here's the comment the man at the top gave: : Will function calls be faster in Perl 6, in general? Using a simple : benchmark, an empty subroutine called with no arguments took around : 1500 machine cycles to execute on Perl 5. Surely a nice new JIT and : better VM should make function calls less expensive, tight loops in : general are a bad idea in Perl 5 - no inlining. Except for constants. Perl 6 should be much better in this regard, provided you make use of the formal parameter syntax. The old way of setting up @_ with default read/write parameters is one place that slows down Perl 5 subroutine calls, so the newer signatures that default the argument list to being constant should help the optimizer out a great deal, since it can then just pull arguments straight from wherever they're stored, whether stack or register. The JIT (which already exists!) will also help, hopefully. Larry [Wall, on the perl6-language mailing list] --- I suggest you don't bother Larry about it.. I asked when it was reasonably appropriate and relevent to the discussion. (A thread on whether tail recursion would be optimised in Perl 6). Jonathan Paton __________________________________________________ Do You Yahoo!? Everything you'll ever need on one web page from News and Sport to Email and Music Charts http://uk.my.yahoo.com -- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
