RFR: 8342393: Promote commutative vector IR node sharing [v20]

[Emanuel Peter]

On Thu, 30 Jan 2025 13:21:01 GMT, Jatin Bhateja <jbhateja at openjdk.org> wrote:

>> test/hotspot/jtreg/compiler/vectorapi/VectorCommutativeOperSharingTest.java line 38:
>> 
>>> 36:  * @library /test/lib /
>>> 37:  * @summary Promote vector IR node sharing
>>> 38:  * @requires (os.simpleArch == "x64")
>> 
>> Oh, I see you added it here, rather than at each IR rule. It would be nice to have this test also execute on other machines, for additional coverage.
>> 
>> Can you instead simply restrict it with `avx` features? And if that is not enough, and you do need 64bit restriction, then use this:
>> `applyIfPlatform = {"64-bit", "true"}`
>
>> Oh, I see you added it here, rather than at each IR rule. It would be nice to have this test also execute on other machines, for additional coverage.
>> 
> These tests are only significant from commoning point of view which is checked through IR rule.
> 
> In addition **foundational optimizations like GVN** is target indipendent hence verifying it for a target which supports all the IR nodes covered by test should suffice. Which is why I restricted it to x64.

That would be sad, because we can still profit from all the value verification for other platforms.

And who knows, we may add similar instructions for other platforms as well, and then the value verification would come in really handy.

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PR Review Comment: https://git.openjdk.org/jdk/pull/22863#discussion_r1935627021