On Tue, 12 May 2026 08:15:57 GMT, Quan Anh Mai <[email protected]> wrote:
>> src/hotspot/share/opto/macro.cpp line 2502: >> >>> 2500: >>> 2501: bool is_add = addsub->Opcode() == Op_AddI128T; >>> 2502: Node* new_lo; >> >> If `addsub->result_lo_or_null() == null` and `addsub->result_hi_or_null() == >> null`, seems like `new_lo` would be created unnecessarily. Is this likely to >> happen? If so looks maybe it could be coded in a more efficient way? > > Hi @galderz , thanks for your comment. If both projections are `nullptr` then > the node should be dead and removed by IGVN. Although, it is true that if `n` is `SubI128T` and `result_lo_or_null` is `nullptr`, then `new_lo` is redundant. But I think that it will be collected if it is dead anyway, and it is not worth complicating the code for a negligible efficiency improvement. ------------- PR Review Comment: https://git.openjdk.org/jdk/pull/31008#discussion_r3224811553
