RFR: JDK-8321017: Record in JFR that IEEE rounding mode was corrupted by loading a library [v2]

[Matthias Baesken]

On Fri, 1 Dec 2023 09:05:22 GMT, Matthias Baesken <mbaesken at openjdk.org> wrote:

>> [JDK-8295159](https://bugs.openjdk.org/browse/JDK-8295159) added some IEEE conformance checks and corrections of the floating point environment on Linux and macOS/BSD, and later some UL logging was added too.
>> However the information is not added to the JFR events, and this should be enhanced.
>> The already existing NativeLibraryLoad event can be used for storing the additional information, because the IEEE conformance check and fenv  get/set  is placed in the HS dlopen_helper , where already the NativeLibraryLoad  event objects are created/commited .
>
> Matthias Baesken has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Adjust macOS coding

> /label jfr
> 
> I'm not sure I understand the issue, but adding a field to an event because of a GCC bug seems excessive.

I think in practise the issue happens mostly when using binaries (shared libs) compiled by gcc with certain flags.
But it could happen as well with other shared libs loaded by the JVM that mess around with the fp environment ; that's why we check and reset now the fp env.
Maybe Andrew Haley  could comment, he knows better about the details of these issues .

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PR Comment: https://git.openjdk.org/jdk/pull/16903#issuecomment-1838012540