On Tue, Nov 22, 2011 at 2:55 AM, Richard Henderson <r...@redhat.com> wrote: > On 11/21/2011 05:31 PM, Jiangning Liu wrote: >> My question is essentially is "May I really use REG_EXPR in back-end code?" >> like the patch I gave below? > > I suppose.
I'm not so sure ;) At least checking for BOOLEAN_TYPE is incomplete - you miss 1-bit precision types of the same signedness as bool. The middle-end doesn't distinguish between them anymore (semantically, that is)... > Another alternative is to use BImode for booleans. Dunno how much of that > you'd be able to gleen from mere rtl expansion or if you'd need boolean > decls to be expanded with BImode. ... which probably also means consistently getting BImode won't work? Richard. > The later would probably need a target hook. I've often wondered how much > ia64 would benefit from that too, being able to store bool variables directly > in predicate registers. > > All of this almost certainly must wait until stage1 opens up again though... > > > r~
