From: Thomas Kirchner <lists@...>
Date: 2006-05-31T01:53:09+09:00
Subject: Re: How to Improve Performance Now. Re: Zed and Luis drop the bombonRuby's poor performance

* On May 30 14:07, Jon Smirl (ruby-talk@ruby-lang.org) wrote:
> Experiments done with the Linux kernel show -Os (optimize for size)
> runs faster than -O3. The Os code is smaller and more of it can fit in
> the CPU cache. The cost of cache misses out weighs the benefits of O3
> optimizations.

This heavily depends on the type of CPU you have, though.  Different 
processors have different cache sizes, and different compiler flags will 
benefit different processors... differently!

-Os might be better on older processors with smaller caches, and -O2 (and 
sometimes -O3) might be better on newer processors that can cache the 
bigger binaries.  You should really do your own testing rather than going 
by vague experimental results.

Tom