From:	Martin Str|mberg <ams AT father DOT ludd DOT luth DOT se>
Newsgroups:	comp.os.msdos.djgpp
Subject:	Re: Voodoo optimization?
Date:	14 Jul 2000 02:25:57 GMT
Organization:	University of Lulea, Sweden
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Message-ID:	<8kltnl$rs6$1@news.luth.se>
References:	<20000706015618 DOT 01353 DOT 00001528 AT ng-bj1 DOT aol DOT com>
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S. T. L. <stl137 AT aol DOT com> wrote:
: Hi. I've been trying to squeeze more optimized code out of DJGPP by playing
: with various switches.  (I don't know C yet, but I hope to learn it soon!)  I'm
: compiling BladeEnc, an MP3 encoder, and want to see how fast I can get it. 
: (No, I don't use it to transfer music over the Internet.)  By turning on
: various switches, I've found that the commandline
: GCC -s -O2 -march=i686 -fomit-frame-pointer -ffast-math -funroll-loops
: -funroll-all-loops -malign-double -fstrict-aliasing -o BLADE.EXE *.c
: seems to produce the fastest code.  (I'm doing this on a Pentium III system.)
: Am I missing any blindingly obvious switches I should be trying?  I've tried
: several other switches, but they all have no effect or detrimental effects. 
: I'm looking for speed, not for size.

: (BladeEnc's homepage is at bladeenc.mp3.no and is under the LGPL.)

: Thanks for your time!

: -*---*-------
: S.T.L.  My Quotes Page * http://quote.cjb.net * leads to my NEW site.
: Pages up: 419 Quotes, 52 reviews of 169 science books, and a review of
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Well if you really want something to do, try optimising each .c file
individually and use hte best options for each file.

If you want to go even further, then you could put every function in
it's own file and do the above.

Another angle can be to run it with profiling, and see if there some
pieces that stick out that should be recoded/rethought.


Right,

							MartinS

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