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

[Jeff Law]

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