https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96376
Kewen Lin <linkw at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |linkw at gcc dot gnu.org --- Comment #5 from Kewen Lin <linkw at gcc dot gnu.org> --- By checking the case vect-alias-check.c on the sparc machine, although vectorizer does the versioning for the alignment requirement and is able to set the misaligned flag off for misaligned DRs, it bypasses the DRs *b_20(D) and MEM[(int *)b_20(D) + 4B], as they satisfy the condition check !vect_relevant_for_alignment_p. if (aligned_access_p (dr_info) || !vect_relevant_for_alignment_p (dr_info)) continue; More specific, it's due to these two DR's steps are unchanged in the loop (b[0] and b[1]). /* Scatter-gather and invariant accesses continue to address individual scalars, so vector-level alignment is irrelevant. */ if (STMT_VINFO_GATHER_SCATTER_P (stmt_info) || integer_zerop (DR_STEP (dr_info->dr))) return false; A simple fix seems to be: diff --git a/gcc/tree-vect-data-refs.c b/gcc/tree-vect-data-refs.c index 2b4421b5fb4..d5f52929f89 100644 --- a/gcc/tree-vect-data-refs.c +++ b/gcc/tree-vect-data-refs.c @@ -1186,7 +1186,7 @@ vect_update_misalignment_for_peel (dr_vec_info *dr_info, /* Return true if alignment is relevant for DR_INFO. */ -static bool +bool vect_relevant_for_alignment_p (dr_vec_info *dr_info) { stmt_vec_info stmt_info = dr_info->stmt; diff --git a/gcc/tree-vect-stmts.c b/gcc/tree-vect-stmts.c index cec5c601268..8a04f55fdb1 100644 --- a/gcc/tree-vect-stmts.c +++ b/gcc/tree-vect-stmts.c @@ -2369,7 +2369,8 @@ get_load_store_type (vec_info *vinfo, stmt_vec_info stmt_info, return false; } - if (*alignment_support_scheme == dr_unaligned_unsupported) + if (*alignment_support_scheme == dr_unaligned_unsupported + && vect_relevant_for_alignment_p (STMT_VINFO_DR_INFO (stmt_info))) { if (dump_enabled_p ()) dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location, diff --git a/gcc/tree-vectorizer.h b/gcc/tree-vectorizer.h index 7c6de8397b3..067222ffe39 100644 --- a/gcc/tree-vectorizer.h +++ b/gcc/tree-vectorizer.h @@ -1935,6 +1935,7 @@ extern tree vect_get_new_ssa_name (tree, enum vect_var_kind, extern tree vect_create_addr_base_for_vector_ref (vec_info *, stmt_vec_info, gimple_seq *, tree, tree = NULL_TREE); +bool vect_relevant_for_alignment_p (dr_vec_info *dr_info); /* In tree-vect-loop.c. */ extern widest_int vect_iv_limit_for_partial_vectors (loop_vec_info loop_vinfo);