RFR (S) 8244510: Shenandoah: invert SHC2Support::is_in_cset condition

Roman Kennke rkennke at redhat.com
Wed May 6 09:57:35 UTC 2020

Looks reasonable.

Thank you,

> RFE:
>   https://bugs.openjdk.java.net/browse/JDK-8244510
> Current code in SHC2Support::is_in_cset treats "in cset" branch as frequent. We should really invert
> it after SFX barriers make that condition much less likely. It improves some benchmarks without any
> observable regressions on others. Note I opted to invert the condition instead of changing the
> probabilities, because I think it flows better: test_in_cset is UNLIKELY to be true now.
> Webrev:
>   https://cr.openjdk.java.net/~shade/8244510/webrev.01/
> Testing: hotspot_gc_shenandoah, benchmarks

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