On Fri, May 6, 2022 at 10:32 PM Eugene Rozenfeld via Gcc-patches <gcc-patches@gcc.gnu.org> wrote: > > Calling count.apply_scale with a 0 denominator causes an assert. > This change guards against that. > > Tested on x86_64-pc-linux-gnu. > > gcc/ChangeLog: > * tree-loop-vect-manip.cc (vect_do_peeling): Guard against applying > scale with 0 denominator. > --- > gcc/tree-vect-loop-manip.cc | 9 +++++---- > 1 file changed, 5 insertions(+), 4 deletions(-) > > diff --git a/gcc/tree-vect-loop-manip.cc b/gcc/tree-vect-loop-manip.cc > index 1d4337eb261..db54ae69e45 100644 > --- a/gcc/tree-vect-loop-manip.cc > +++ b/gcc/tree-vect-loop-manip.cc > @@ -2989,10 +2989,11 @@ vect_do_peeling (loop_vec_info loop_vinfo, tree > niters, tree nitersm1, > get lost if we scale down to 0. */ > basic_block *bbs = get_loop_body (epilog); > for (unsigned int i = 0; i < epilog->num_nodes; i++) > - bbs[i]->count = bbs[i]->count.apply_scale > - (bbs[i]->count, > - bbs[i]->count.apply_probability > - (prob_vector)); > + if (bbs[i]->count.nonzero_p ()) > + bbs[i]->count = bbs[i]->count.apply_scale > + (bbs[i]->count, > + bbs[i]->count.apply_probability > + (prob_vector));
So exactly what the FIXME in the comment above says happens. It might be better to save/restore the old counts if the intent is to get them back. I'm not exactly sure where the other scaling happens though. Richard. > free (bbs); > } > > -- > 2.25.1
