Re: Faster make depend
Kai Henningsen (msmith@quix.robins.af.mil)
Fri, 26 Jul 1996 15:58:26 -0400 (EDT)
> > I was a little over-general in the int/float cpu comment.
> > Not all arithmetic operations are equal. What I was getting
> > at is the division specifically. With coprocessor on some
> > machines (my Alpha at least) floating divs are faster.
>
> That is just the Alpha. It hauls 64-bit data around just for the
> fun of it and (sometimes?) doesn't have hardware division. It
> looks like your machine has hardware support for floating point
> divide but not integer divide.
>
> Normally, the issue is simple math (add, subtract) on 32-bit
> integers or 64-bit double precision floating point. Even if
> you have an FPU you would want to avoid using it.
>
> I think the patch will help you anyway, because perl is usually
> faster than awk. I don't think there is any division.
Ok, thats what I get for spending too much time on my Alpha.
My profiling tells me integer divs are 2x slower than fdivs or
you could look at this way. The chip is fast, and fdivs are 2x faster!
Real-time graphics do _cook_ on this box.
Wonder why the Alpha doesn't have idivs, btw?
Melvin