This avoids randomly (based on whether the stmt is SLP_TREE_REPRESENTATIVE and not a pattern stmt) passing a vector type or NULL to the add_stmt_cost hook for scalar code cost compute. For example the x86 backend uses only the vector type to decide on the scalar computation mode which makes costing off.
So the following explicitely passes the vector type and uses SLP_TREE_VECTYPE for this purpose. Bootstrap and regtest running on x86_64-unknown-linux-gnu. 2020-10-29 Richard Biener <rguent...@suse.de> * tree-vect-slp.c (vect_bb_slp_scalar_cost): Pass SLP_TREE_VECTYPE to record_stmt_cost. --- gcc/tree-vect-slp.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/gcc/tree-vect-slp.c b/gcc/tree-vect-slp.c index 0a7b8e61632..7a08908cde8 100644 --- a/gcc/tree-vect-slp.c +++ b/gcc/tree-vect-slp.c @@ -3937,7 +3937,8 @@ vect_bb_slp_scalar_cost (vec_info *vinfo, continue; else kind = scalar_stmt; - record_stmt_cost (cost_vec, 1, kind, orig_stmt_info, 0, vect_body); + record_stmt_cost (cost_vec, 1, kind, orig_stmt_info, + SLP_TREE_VECTYPE (node), 0, vect_body); } auto_vec<bool, 20> subtree_life; -- 2.26.2