From: Dave Thomas <Dave@...>
Date: 2000-07-05T12:35:08-05:00
Subject: [ruby-talk:03843] A performance improvement!


I've been working on performance testing, and I came across a strange
situation. In my tests,

     str.gsub!(/[abc]/, '')

ran slower than

     str.gsub!(/a/, '')
     str.gsub!(/b/, '')
     str.gsub!(/c/, '')

Matz ran the same tests, and got opposite results.

The difference between our two systems was the version of gcc. I was
running egcs 2.91, and he was running gcc 2.95.2.

So, I upgraded my compiler, and lo! my test timings changed
dramatically.

                 Old           New

     Test1     1.339         0.647

     Test2     0.671         0.259


So, a compiler upgrade gave me a factor of 2 performance improvement
with code than contains character classes.

Just thought I'd pass that on.


Regards


Dave