RFR: 8328702: C2: Crash during parsing because sub type check is not folded

Roland Westrelin roland at openjdk.org
Wed Mar 27 16:08:25 UTC 2024


On Wed, 27 Mar 2024 15:44:46 GMT, Christian Hagedorn <chagedorn at openjdk.org> wrote:

> I'm not sure about how much benefit it gives us. A quick JBS search for "ExpandSubTypeCheckAtParseTime" revealed a few issues - but would need to double check how many of them really only triggered with that flag and were real bugs. So, apart from having it as a stress option, I don't see a real benefit for it - but that might be a good enough reason to keep it for now.
> 
> What do you think?

It also has a maintenance cost (you had to make a code change for it in this PR and I also remember having to take `ExpandSubTypeCheckAtParseTime` into consideration at some point). I would vote for removing it unless it's known to have some value.

-------------

PR Comment: https://git.openjdk.org/jdk/pull/18512#issuecomment-2023150157


More information about the hotspot-compiler-dev mailing list