https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109176
Jakub Jelinek <jakub at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |rsandifo at gcc dot gnu.org --- Comment #5 from Jakub Jelinek <jakub at gcc dot gnu.org> --- Before veclower2 we had/have _7 = ba_5(D) < a_6(D); _8 = svnand_b_z (_7, _7, _7); _9 = VEC_COND_EXPR <_7, _8, _7>; where _7/_8/_9 are all __SVBool_t. Before the r11-1445 changes, the VEC_COND_EXPR would be left untouched, because expand_vec_cond_expr_p (__SVBool_t, __SVBool_t, SSA_NAME) is true on aarch64. Now it doesn't, because _7 def_stmt is a comparison, and so expand_vec_cond_expr_p (__SVBool_t, VNx16QI, LT_EXPR). --- gcc/tree-vect-generic.cc.jj 2023-03-12 22:36:06.356178068 +0100 +++ gcc/tree-vect-generic.cc 2023-03-20 16:31:03.321831866 +0100 @@ -1063,6 +1063,12 @@ expand_vector_condition (gimple_stmt_ite return true; } + if (!TYPE_VECTOR_SUBPARTS (type).is_constant () + && VECTOR_BOOLEAN_TYPE_P (type) + && VECTOR_BOOLEAN_TYPE_P (TREE_TYPE (a)) + && expand_vec_cond_expr_p (type, TREE_TYPE (a), TREE_CODE (a))) + return true; + /* Handle vector boolean types with bitmasks. If there is a comparison and we can expand the comparison into the vector boolean bitmask, or otherwise if it is compatible with type, we can transform basically restores the behaviour here for the SVE boolean types and makes it compile. Because otherwise, unless this would be solvable by the AVX512 "Handle vector boolean types with bitmasks." code the non-constant vector elts cases will always ICE in the following code, int nunits = nunits_for_known_piecewise_op (type); requires constant TYPE_VECTOR_SUBPARTS and the code really isn't prepared to handle anything non-constant.