[fedora-arm] Support for ARMv7, hardware math

[Vaclav Mocek]

On 11/28/2010 11:14 AM, Peter Robinson wrote:
>
> > From my interpretation of the gcc notes on float it looks like the two
> are mutually exclusive. From the notes "Note that the hard-float and
> soft-float ABIs are not link-compatible; you must compile your entire
> program with the same ABI, and link with a compatible set of
> libraries. "
The reason is entirely different calling convention. With hardware 
floating point linkage, arguments and return values are passed in VFP 
registers; you have to be sure that target contain VFP. With software 
floating point linkage arguments and return values are passed in ARM 
registers; it is slower - data has to be transferred to VFP.
> My understanding is that all the ARMv7 chips have vfp3 but there's two
> different versions (16 and 32) which means that all the A8 chips
> should support that, and it seems on the A9 its optional.
Choice of vfp3-16 is the best option right now, otherwise the number of 
possible targets would be limited.


I vote for vfp3-16 + hardfp + separate repository ;-)

Vaclav







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