http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58079
rsandifo at gcc dot gnu.org <rsandifo at gcc dot gnu.org> changed:
What |Removed |Added
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CC| |rsandifo at gcc dot gnu.org
Assignee|unassigned at gcc dot gnu.org |rsandifo at gcc dot
gnu.org
--- Comment #4 from rsandifo at gcc dot gnu.org <rsandifo at gcc dot gnu.org>
---
(In reply to Mikael Pettersson from comment #3)
> Started with Uros' PR54457 patch in r191928. I'm not sure if that patch was
> wrong or if it exposed a problem in the mips backend.
Looks like a latent combine bug that's being exposed by the better
subreg optimisation. simplify_comparison is legitimately widening
a QImode comparison to SImode (since the target doesn't support
QImode comparisons), but combine_simplify_rtx is then trying to substitute
these widened values in-place, which trips the sanity check in do_SUBST.
I'm about to post a patch for comments.
