Mixing hard and soft floating point?

[Joakim Tjernlund]

Wolfgang Denk <wd at denx.de> wrote on 17/10/2009 21:34:54:
>
> Dear Joakim Tjernlund,
>
> In message <OFEC00B9FB.B03AA854-ONC1257652.00644350-C1257652.
> 00651551 at transmode.se> you wrote:
> >
> > > Recompile and relink it with soft-fp as well. Or ask the provider to
> > > do that.
> >
> > That is what I am trying do/find out. The supplier claims that
> > it should not be a problem and is ATM unwilling to recompile the app/libs.
> > I am not convinced won't cause problems, not to mention performance degradation.
>
> If the application is really using FP instructions a lot, then there
> is a huge difference between using soft-float and MATH_EMU; I
> remember test cases where soft-float was faster by factors of
> 500...1000.

Ouch, I had no idea that it could be that much.

>
> > OK, but then you don't mix some libs/apps with soft and other
> > apps/libs with hard FP?
>
> No, we never tried that. Sounds scary to me.

Yes, it did to me too. That is why I figured I should ask on the
list.