> @@ -7577,8 +7577,14 @@ vectorizable_reduction (loop_vec_info loop_vinfo,
> values into the low-numbered elements. */
> if ((double_reduc || neutral_op)
> && !nunits_out.is_constant ()
> - && (SLP_TREE_LANES (slp_node) != 1 && !reduc_chain)
> - && !operand_equal_p (neutral_op, vect_phi_initial_value
> (reduc_def_phi))
> + && (!neutral_op
> + || (!reduc_chain
> + && (SLP_TREE_LANES (slp_node) != 1
> + || (!VECT_REDUC_INFO_REUSED_ACCUMULATOR (reduc_info)
> + && STMT_VINFO_DEF_TYPE (stmt_info)
> + != vect_reduction_def))
> + && !operand_equal_p (neutral_op,
> + vect_phi_initial_value (reduc_def_phi))))
> && !direct_internal_fn_supported_p (IFN_VEC_SHL_INSERT,
> vectype_out, OPTIMIZE_FOR_SPEED))
> {
Not that I had much exposure to this part before (and not to take anything away
from your fix) but I find the new condition even more confusing :)
Like nested neutral_op, !neutral_op, reduc_chain, !reduc_chain.
Can we split it somehow or add more comments?
--
Regards
Robin
