[patch][5/5] powerpc V2: Add the general support for Embedded Floating-Point instructions

[Zhu Ebony-r57400]

> -----Original Message-----
> From: Segher Boessenkool [mailto:segher at kernel.crashing.org] 
> Sent: Friday, February 09, 2007 10:40 PM
> To: Kumar Gala
> Cc: paulus at samba.org; Zhu Ebony-r57400; linuxppc-dev at ozlabs.org
> Subject: Re: [patch][5/5] powerpc V2: Add the general support 
> for Embedded Floating-Point instructions
> 
> >>> I thought we were going to have some general Kconfig option to 
> >>> enable all this?  EMDEDDED_FP_IEEE or something like that
> >>
> >> So that users have chance to enable/disable fully IEEE compliance?
> >> Segher
> >> had mentioned this, and it sounds reasonable.
> >
> > Its alot of code to bring in if you don't care about IEEE 
> compliance.
> 
> Yes certainly, and that's important for embedded applications.
> 
> My point however is that this should be selectable *per 
> process* at runtime.  Compare to the AltiVec situation (where 
> processes can select (non-)IEEE behaviour by themselves); 
> most tasks do
> *not* want IEEE behaviour as it is just too expensive (and 
> not necessary for many applications).
> 
> 
> Segher

Sorry for the delaying response since I just came back from vacation.

Agreed with you that the IEEE handler is expensive for processes.  Do
you
think adding a switch to the Kconfig option is not enough?  I'm
wondering how
to make it selectable *per process* at runtime.

Ebony