Re: Floating point performance (was Re: compiling LUA for uClinux)

[Asko Kauppi <asko.kauppi@...>]

I did some, and the use of double or int is fairly the same speed on 
modern (PowerPC, i686) processors.  However, the 'int' variant was not 
pure int, but a mixture of int and float, which does create some 
conversion overhead.  Anyhow, I can say that at least there is no order 
of magnitude difference between the two.

-ak


5.4.2005 kello 19:18, Thamer Al-Harbash kirjoitti:

 On Tue, 5 Apr 2005, DC wrote:
> > > > I also changed LUA_NUMBER from double to int.
> > > Why did you change LUA_NUMBER from double to int?
> >
> > I was concerned with performance for chips that do not have floating
> > point hardware.
>
> I don't want to turn this into a heated argument but I'd like to
> ask. Has anyone done profiling for Lua code that does a lot of
> calculations and seen if there is any significant difference
> between using doubles or ints on a Intel Pentium class processor?
>
> Also is there any danger in compiling the lua interpreter to use
> ints instead of double? I understand it's a compile time option.
>
> --
> Thamer Al-Harbash
> GPG Key fingerprint: D7F3 1E3B F329 8DD5 FAE3  03B1 A663 E359 D686 AA1F