https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110776
--- Comment #5 from rguenther at suse dot de <rguenther at suse dot de> --- On Tue, 25 Jul 2023, linkw at gcc dot gnu.org wrote: > https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110776 > > Kewen Lin <linkw at gcc dot gnu.org> changed: > > What |Removed |Added > ---------------------------------------------------------------------------- > CC| |rguenth at gcc dot gnu.org > > --- Comment #3 from Kewen Lin <linkw at gcc dot gnu.org> --- > The failure exposed one special case: there is one stmt > > # VUSE <.MEM_404> > _15 = *_14; > > its STMT_VINFO_STRIDED_P (stmt_info) is set, memory_access_type is > VMAT_ELEMENTWISE and alignment_support_scheme is dr_unaligned_supported, its > vector type is "vector(1) long int", so in the handling it's taken as: > > /* Load vector(1) scalar_type if it's 1 element-wise vectype. */ > else if (nloads == 1) > ltype = vectype; > > as its ltype is vector type, we cost it with > > if (VECTOR_TYPE_P (ltype)) > vect_get_load_cost (vinfo, stmt_info, 1, > alignment_support_scheme, > misalignment, > false, &inside_cost, nullptr, > cost_vec, > cost_vec, true); > > as it's dr_unaligned_supported, it's costed as unaligned_load then causes the > ICE. One idea is to teach rs6000_builtin_vectorization_cost about one single > lane vector unaligned load as scalar_load. But I think it's simple to treat > single lane vector load as scalar_load, as I expect veclower will lower it > later. > > diff --git a/gcc/tree-vect-stmts.cc b/gcc/tree-vect-stmts.cc > index 4622d6a04ef..bdf4c12cd03 100644 > --- a/gcc/tree-vect-stmts.cc > +++ b/gcc/tree-vect-stmts.cc > @@ -9985,7 +9985,9 @@ vectorizable_load (vec_info *vinfo, > { > if (costing_p) > { > - if (VECTOR_TYPE_P (ltype)) > + /* For a single lane vector type, we should cost it as > + scalar_load to avoid ICE, see PR110776. */ > + if (VECTOR_TYPE_P (ltype) && lnel > 1) > vect_get_load_cost (vinfo, stmt_info, 1, > alignment_support_scheme, > misalignment, > false, &inside_cost, nullptr, > cost_vec, > > Hi Richi, what do you think of this? I think apart from the consideration what a single element vector is compared to a scalar, a more to-the-point fix is if (VECTOR_TYPE_P (ltype) && memory_access_type != VMAT_ELEMENTWISE)
