Author: William Bryant
Date: 08:24:54 09/04/00
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On September 04, 2000 at 03:09:39, Will Singleton wrote: >I used the pragma method to locate which code caused the slowdown. I set >optimization to 4 (max) in the global prefs, then tried compiling various >procedures with opt=2. I found that eval() was causing the slowdown. > >Then I tried to isolate exactly what part of the extra optimizing was the >culprit. It turns out it was opt_strength_reduction. I cleared it for eval(), >and now things are working fine. Apparently, strength_reduction replaces >multiplication instructions inside loops with addition code. Have no idea why >this is a problem, unless the compiler is broken (not likely) or I'm doing >something odd with multiplication. > >So with global opt=4, I've just speeded up by 12%. Not bad for an hour's work. >Thanks, William. > >Will It's nice to be able to answer a question now and then, rather than just ask. I tested Screamer at Opt = 2 and Opt = 4. The lower optimization lost about 1 second of search speed for each 30 seconds of search or approx. 3.3% in an uncomplicated position. William wbryant@ix.netcom.com
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