RFR: 8299259: C2: Div/Mod nodes without zero check could be split through iv phi of loop resulting in SIGFPE

Tue Jan 10 11:31:56 UTC 2023

On Tue, 10 Jan 2023 10:43:30 GMT, Christian Hagedorn <chagedorn at openjdk.org> wrote:

> Thanks Vladimir for your review!
> 
> > I think this is only problematic for some architectures. Integer division instructions of some other architectures (some RISC architectures like PPC64) never raise any signals, so they can get executed speculatively without zero check. Should we have an extra RFE for that?
> 
> I think that might be worth to investigate in a separate RFE if these divisions by zero do not have any other side effects. Then I guess it should be safe to allow this as we would not use the result of the problematic division.

I have filed [JDK-8299857](https://bugs.openjdk.org/browse/JDK-8299857). Thanks!

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PR: https://git.openjdk.org/jdk/pull/11900