Mixing hard and soft floating point?
Wolfgang Denk
wd at denx.de
Sun Oct 18 06:34:54 EST 2009
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.
> 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.
Best regards,
Wolfgang Denk
--
DENX Software Engineering GmbH, MD: Wolfgang Denk & Detlev Zundel
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
The connection between the language in which we think/program and the
problems and solutions we can imagine is very close. For this reason
restricting language features with the intent of eliminating pro-
grammer errors is at best dangerous.
- Bjarne Stroustrup in "The C++ Programming Language"
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