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Re: [PATCH/RFC] Avoid invalid subregs during reload, call for testers
On Wed, 6 Dec 2006, Rask Ingemann Lambertsen wrote:
> Can you describe somehow what subreg_regno_offset() should return when
> the offset isn't representable so that the return value is useful for
> computing register ranges?
It should return the offset of the first hard register involved in the
subreg (and subreg_nregs return the number of hard registers involved).
Ideally, it should be split into subreg_regno_offset (require
representable, return the offset such that you can replace the subreg by a
reg at that offset) and subreg_regno_starting_offset (don't require
representable) and likewise subreg_regno into subreg_regno and
subreg_starting_regno. But the return values would be the same, it's just
the strict versions would contain an extra assertion.
--
Joseph S. Myers
joseph@codesourcery.com