When change_vec_perm_layout runs into a permute combining two nodes where one is invariant and one internal the partition of one input can be -1 but the other might not be. The following supports this case by simply ignoring inputs with input partiton -1.
I'm not sure this is correct but it avoids ICEing when accessing that partitions layout for gcc.target/i386/pr98928.c with the change to avoid splitting store dataref groups during SLP discovery. Bootstrap and regtest running on x86_64-unknown-linux-gnu (ontop of the SLP series). The change can't break anything that's already broken but I'm not sure this does the right thing - the testcase has an uniform constant. I'll try to come up with a better runtime testcase tomorrow. Hints as to where to correctly fix such case appreciated. * tree-vect-slp.cc (change_vec_perm_layout): Ignore an input partition of -1. --- gcc/tree-vect-slp.cc | 2 ++ 1 file changed, 2 insertions(+) diff --git a/gcc/tree-vect-slp.cc b/gcc/tree-vect-slp.cc index 873748b0a72..f6ec1a81c96 100644 --- a/gcc/tree-vect-slp.cc +++ b/gcc/tree-vect-slp.cc @@ -4828,6 +4828,8 @@ change_vec_perm_layout (slp_tree node, lane_permutation_t &perm, { slp_tree in_node = SLP_TREE_CHILDREN (node)[entry.first]; unsigned int in_partition_i = m_vertices[in_node->vertex].partition; + if (in_partition_i == -1u) + continue; this_in_layout_i = m_partitions[in_partition_i].layout; } if (this_in_layout_i > 0) -- 2.35.3