Mail Archives: djgpp/1998/08/14/20:45:28
Eli Zaretskii wrote:
> On Mon, 10 Aug 1998 D DOT J DOT Eleveld AT anest DOT azg DOT nl wrote:
>
> > > How huge is ``huge''? Can you give some numbers?
> >
> > Ok, I was playing with optimizing the inner loops of the AllegPeg
> Mpeg player
> > library for Allegro. I do my profiling stuff with some
> pentium-specific code
> > that counts clock cycles. With -march=pentium I get 27.7M clock
> cycles per
> > frame with my Pentiun 133 with painfully slow (banked) video card.
> Exactly
> > the same flags and code (just changed the compiler options in Rhide,
> and
> > rebuilt) gets me 32.6M clock cycles per frame.
>
> The difference between 27.7 and 32.6 is merely 17%. I would hardly
> call that a ``huge speed increase''. Numbers around 10%-20% are what
> you would usually get by playing with different optimization
> switches. See section 14.2 of the DJGPP FAQ for more details.
Well, OK, it's not huge, but it is larger than PGCC gave me. -06
made some of my code slower. I'm also pretty sure that -march=pentium
makes things slower on my 350 Mhz pentium II. Anyway, thanks for the
help, I appreciate it.
Doug Eleveld
- Raw text -