more Perl benchmarks

[Perrin Harkins <pe...@elem.com>]

I was talking to some people at the Intel booth at Linux World Expo
yesterday about their compiler, and decided to try it out on Perl.  I
have some results below, but first some caveats:

- perlbench is not a very good measure of how web applications will
perform.  It tends to be weighted towards math functions.

- If your application is spending most of its time doing I/O (i.e.
reading from a database), this will probably not help you.  Most
mod_perl apps are I/O bound, waiting for databases.

- I don't know anything about compiler flags.  I just used the ones that
Intel used in their comparison.

- There were two test failures on the Perl compiled with Intel's
compiler.  I don't know yet if these are serious.

So, with all that out of the way, perlbench showed about a 4%
improvement using "aggressive" optimization flags with gcc, and Intel's
compiler got about 8% above that, or 12% better than Perl compiled with
defaults for Linux.  The details are attached.  Note that my baseline
Perl, compiled with all Linux defaults, still beats the one that ships
with Red Hat 9 by about 20%.

If I get ambitious, I might try compiling enough pieces with icc to run
one of Josh's templating benchmarks.

- Perrin