https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110018
--- Comment #5 from Hongtao.liu <crazylht at gmail dot com> --- Do we know if the stmt belongs to any slp_node in pattern recog? slp_node use SLP_TREE_LANES for vectype which is different from vinfo->vector_mode. Different optabs should be checked according to both vectype_in and vectype_out, for non-slp case, assuming vec_pack/unpack are always used when lhs has different size from rhs, for slp case, sometimes vec_pack/unpack is used, somethings direct conversion is used.
