--- Comment #21 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The releases/gcc-8 branch has been updated by Jakub Jelinek
Author: Jakub Jelinek <ja...@redhat.com>
Date: Fri Feb 14 15:46:13 2020 +0100
combine: Punt on out of range rotate counts [PR93505]
What happens on this testcase is with the out of bounds rotate we get:
Trying 13 -> 16:
Successfully matched this instruction:
(set (reg/v:DI 123 [ <retval> ])
(const_int 0 ))
during combine. So, perhaps we could also change simplify-rtx.c to punt
if it is out of bounds rather than trying to optimize anything.
Or, but probably GCC11 material, if we decide that ROTATE/ROTATERT doesn't
have out of bounds counts or introduce targetm.rotate_truncation_mask,
we should truncate the argument instead of punting.
Punting is better for backports though.
2020-01-30 Jakub Jelinek <ja...@redhat.com>
* combine.c (simplify_comparison) <case ROTATE>: Punt on out of range
* gcc.c-torture/compile/pr93505.c: New test.