[PATCH 3/5] Use simplify_subreg_regno in combine.c:subst

Jeff Law law@redhat.com
Fri Sep 19 06:17:00 GMT 2014


On 09/18/14 04:13, Richard Sandiford wrote:
> combine.c:subst should refuse to substitute a hard register
> into a subreg if the new subreg would not be simplified to a
> simple hard register, since the result would have to be reloaded.
> This is more for optimisation than correctness, since in theory
> the RA should be able to fix up any unsimplified subregs.
>
>
> gcc/
> 	* combine.c (subst): Use simplify_subreg_regno rather than
> 	REG_CANNOT_CHANGE_MODE_P to detect invalid mode changes.
OK independent of other changes.

jeff



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