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Re: hard_regno_nregs == 0 ?


DJ Delorie wrote:
Are there any ports besides m32c that have registers which can hold HI
(or SI I suppose) but not QI values?

IA-64 has branch registers that are only allowed to hold DImode values. We use CANNOT_CHANGE_MODE_CLASS to enforce this.


On x86, the vector registers can hold SImode, but do not allow HImode/QImode loads, and again CANNOT_CHANGE_MODE_CLASS is used to enforce this.

I'm sure that there are other examples out there.
--
Jim Wilson, GNU Tools Support, http://www.specifix.com


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