From: quacci AT vera DOT com (jon)
Newsgroups: comp.os.msdos.djgpp,rec.games.programmer
Subject: Any tips on optimizing C code?
Date: Mon, 12 May 1997 18:15:08 GMT
Organization: Yale University
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Message-ID: <33775c59.19219875@news.cis.yale.edu>
NNTP-Posting-Host: slip-ppp-node-05.cs.yale.edu
To: djgpp AT delorie DOT com
DJ-Gateway: from newsgroup comp.os.msdos.djgpp
Precedence: bulk

I'm interested in understanding what can be done to speed up straight
C code. In the specific thing I am writing, I've already done the
obvious things, like switched most calcs from FP to integer, using bit
shifting wherever possible for multiplying and dividing, etc. But is
there a complied source of information on just
what-is-faster-than-what? Like, does running a "for" loop by
decrementing rather than incrementing actually save a cycle? or does a
"case" command actually beat a series of "if"s? Do global variable
speed things up? I figure there must be something out there that has
the low-down on just this sort of nitty-gritty info.

DJGPP is my compiler of choice, if that makes a difference.