RFR: 8369435: C2: transform (LShiftX (SubX con0 a), con1) into (SubX con0<<con1 (LShiftX a con1)) [v5]

[Emanuel Peter]

On Tue, 28 Oct 2025 09:52:54 GMT, Roland Westrelin <roland at openjdk.org> wrote:

>> We already transform:
>> 
>> (LShiftX (AddX a con0), con1) into (AddX (LShiftX a con1) con0<<con1)
>> 
>> THis is a variant with SubX. I found that this helps RCE.
>
> Roland Westrelin has updated the pull request incrementally with one additional commit since the last revision:
> 
>   whitespace

Looks good to me!

I closed https://bugs.openjdk.org/browse/JDK-8359688 as a duplicate, since you were able to enable the IR rule here.

Amazing, one more MemorySegment case fixed :)

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Marked as reviewed by epeter (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/27842#pullrequestreview-3398728127