RFR: 8321712: C2: "failed: Multiple uses of register" in C2_MacroAssembler::vminmax_fp [v2]

[Emanuel Peter]

On Tue, 9 Jan 2024 18:11:18 GMT, Sandhya Viswanathan <sviswanathan at openjdk.org> wrote:

>> @sviswa7 but is the "same address" not an indication of a missing ideal transformation? Hence, the assert may actually be ok, and the root cause be fixed in the ideal transformation. I think this maybe what @jatin-bhateja was suggesting.
>
> @eme64 Probably, but my goal here is limited. We have to fix this PR within RDP2 i.e. asap. That is why I kept the changes to minimum. On Vladimir's request I have added a minimum change to handle the case when a and b are same.

@sviswa7 Ok, I understand. But a regression test would still be good. We should just reduce the regression test attached to https://bugs.openjdk.org/browse/JDK-8322090, @TobiHartmann mentioned it on JIRA.

I guess we can also file a follow up RFE to improve the Ideal transformations.

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PR Comment: https://git.openjdk.org/jdk/pull/17315#issuecomment-1883554067