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Re: Is (set (subreg:SI (reg:HI) 0) (const_int)) valid rtx?


> Hi Richard,
> 
> > > I had "before register allocation" in mind and assumed a target
> > > architecture allows (set (reg:SI) (const_int)).  Given these, would
> > > you also say that the validity depends on WORD_REGISTER_OPERATIONS as
> > > Joern suggested?
> > 
> > No, I wouldn't think so.  Seems like a "normal" case of
> > a paradoxical subreg to me.  It will require less than
> > desirable work-arounds from reload, if it makes it that
> > far, but it should *work*.
> 
> Hmm.  So if local-alloc causes an ICE due to
> 
>   (set (subreg:SI (reg:HI x) 0)
>        (...)),
> 
> then is it probably a bug in local-alloc, not somebody that creates
> the above rtx!?

Yes, such a subreg is valid.  I've missed the begginig of thread so I
don't know what failure you get, but in general it should work.

Honza
> 
> Kazu Hirata


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