On Tue, Aug 23, 2011 at 10:23:54PM +0200, Uros Bizjak wrote:
> On Tue, Aug 23, 2011 at 10:04 PM, Richard Henderson <r...@redhat.com> wrote:
>
> >> * config/i386/constraints.md (Yp): New register constraint.
> >> * config/i386/i386.md (*addhi_1): Merge with *addhi_1_lea using
> >> Yp register constraint.
> >> (*addqi_1): Merge with *addqi_1_lea using Yp register constraint.
> >> (*ashlhi3_1): Merge with *ashlhi3_1_lea using Yp register constraint.
> >> (*ashlqi3_1): Merge with *ashlqi3_1_lea using Yp register constraint.
> >
> > You can still make use of attribute enabled...
>
> Yes, I am aware of this attribute, but OTOH, I propose that we use it
> for ISA changes and don't mix everything together. I was thinking of
> moving Y2, Y3 and Y4 out of register constraints to "enabled"
> attribute, but they clashed with TARGET_AVX somehow.
The advantage of enabled attribute over the new special constraints is IMHO that
the constraints are exposed to users, they can use them in inline assembly.
You could mix two or three attributes to compute enabled etc. if needed.
Jakub
