Re: [Qemu-devel] [PATCH 0/6] target-alpha: fpu qualifiers, round 2

[Aurelien Jarno <aurelien@aurel32.net>]

On Wed, Feb 24, 2010 at 12:24:55PM +0100, Richard Henderson wrote:
> On 02/23/2010 02:58 PM, Aurelien Jarno wrote:
> >>I have totally rewritten the patch to be more along the line
> >>that Laurent was suggesting, in that the rounding mode and other
> >>qualifiers are totally parsed within the translator.  I no longer
> >>pass the FN11 field to the helper functions.
> >
> >What's the benefit of doing that? I don't say it's wrong, I just want
> >to understand. Otherwise the patch looks good, so it can probably be
> >applied without any change.
> 
> I seem to recall Laurent opining that doing the interpretation
> of the opcode in two different places was less than clean, and
> in the end I agree with him.
> 
> FWIW, this configuration would also be compatible with a
> future TCG enhancement to generate fp code, whereas the first
> config would not.

I have applied the patch, but in order to avoid doing the same for all
targets, it might be a good idea to directly provide TCG functions to
modify FP_STATUS instead of using the interface from softfloat.h. This
would also have the advantage of clearly defining this interface, and 
make sure that the alpha target is not broken by a change in softfloat.h.

-- 
Aurelien Jarno                          GPG: 1024D/F1BCDB73
aurelien@aurel32.net                 http://www.aurel32.net