From:	"John M. Aldrich" <fighteer AT cs DOT com>
Newsgroups:	comp.os.msdos.djgpp
Subject:	Re: Compile extensions
Date:	Thu, 16 Jan 1997 19:05:04 -0800
Organization:	Two pounds of chaos and a pinch of salt
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To:	djgpp AT delorie DOT com
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Thomas Harte wrote:
> 
>         Which extensions to the regular GCC command line do you all recommend to
> use when compiling for speed over size. My programs use a lot of fixed
> point maths, and some occasional floating point, and use both the Allegro
> and SB_LIB libraries.

Look into the gcc docs for Optimization Flags.  In general, you want to
use one of -O, -O2, or -O3, with each level attempting to achieve a
higher speed-size tradeoff.  Generally, -O2 is the best overall choice,
giving you maximum speed for very little increase in size, and sometimes
even a decrease!  -O3 goes all out, inlining as much code as it can. 
This significantly bloats your program's size, but doesn't always
improve speed to compensate.

You can also specify various -f switches to directly control what
optimizations are and aren't used.

A word of advice:  Definitely read all of chapter 14 of the FAQ; it
contains some excellent tips on speed and optimization.

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