https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104026
--- Comment #8 from rdapp at linux dot ibm.com --- I think you're right. In one of the last iterations of the patch I moved + LOOP_VINFO_PARTIAL_LOAD_STORE_BIAS (loop_vinfo) = partial_load_bias; after the unsupported check. It is now only set to something meaningful if it is not unsupported. The following should help: diff --git a/gcc/tree-vect-loop.c b/gcc/tree-vect-loop.c index 8748b1a5593..3c87920090b 100644 --- a/gcc/tree-vect-loop.c +++ b/gcc/tree-vect-loop.c @@ -1170,6 +1170,9 @@ vect_verify_loop_lens (loop_vec_info loop_vinfo) machine_mode len_store_mode = get_len_load_store_mode (loop_vinfo->vector_mode, false).require (); + LOOP_VINFO_PARTIAL_LOAD_STORE_BIAS (loop_vinfo) = + VECT_PARTIAL_BIAS_UNSUPPORTED; + signed char partial_load_bias = internal_len_load_store_bias (IFN_LEN_LOAD, len_load_mode);