Re: Stacks, registers, and bytecode. (Oh, my!)

[mooring]

On Tue, May 29, 2001 at 06:20:40PM -0400, Dan Sugalski wrote:
> 
> I really think we'll win if we have support for at least integers as well 
> as PMCs. There's potentially a lot of integer work that'll be generated by 
> the optimizer and, while integer opcodes might not make the interpreter 
> much faster, they'll speed up TIL and generated C code significantly since 
> they won't need to call opcodes.

How much integer arithmetic does the perl interpreter actually do?

I've profiled a quite a few perl5 versions on a lot of different perl
programs, and about the only programs where integer ops made it above
the background noise were things like Ackerman, iterative Fibonacci, and
some Q&D image processing on PBM files. Most of the programs I looked
at didn't do much of any integer arithmetic.

Figuring out where the hot spots are in an interpreter for a general-
purpose programming language is hard. I'd recommend against special
cases in the registers, since it's not clear how much they'd help.
-- 
Ed Mooring ([EMAIL PROTECTED])