On Fri, 18 Oct 2024 02:41:47 GMT, Quan Anh Mai <qa...@openjdk.org> wrote:
> The issues I have with this patch are that: > > * It convolutes the graph with machine-dependent nodes early in the compiling > process. MulVL is a machine independent IR, we create a machine dependent IR post matching. > * It overloads `MulVL` with alternative behaviours, it is fine now as we do > not perform much analysis on this node but it would be problematic later. I > think it is more preferable to have a separate IR node for this like > `MulVLowIToLNode`, or have this transformation be done only just before > matching, or both. I see this is as a twostep optimization, in the first step we do analysis and annotate additional information on existing IR, which is later used by instruction selector. I plan to subsume first stage with enhanced dataflow analysis going forward. ------------- PR Comment: https://git.openjdk.org/jdk/pull/21244#issuecomment-2421300738
