Mail Archives: djgpp/1997/01/20/22:17:31
> But my disappointment was big. My program is about 20 times
> slower using DJGPP 2 than DJGPP 1! I used the same compiler-
> options (-O2 -m486) I also tryed by using -O6. But the speed
> was the same: *much* slower. BTW I use GRX2.0 also.
>
> Who can help me make my prog faster (as fast as in DJGPP 1)?
From the djgpp FAQ:
------------------------------------------------------------------------In general, GCC 2.7.2 which comes with DJGPP v2.0 generates tighter,
faster code. But it sometimes produces buggy code when "strength
reduction" optimizations are enabled. So DJGPP by default disables this
kind of optimization, which might sometimes yield slower code. If you
need extra speed, first debug your program with default optimization
options, and then recompile with -fstrength-reduce switch to see if that
makes any difference.
GCC has a plethora of other optimization options which might make your
code faster; the best way to know is to profile and experiment.
--------------------------------------------------------------------------
Rob Vasquez
Digital Fx '97
email: digital DOT fx AT worldnet DOT att DOT net
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