RFR: JDK-8320892: AArch64: Restore FPU control state after JNI [v3]

[Thomas Stuefe]

On Tue, 28 Nov 2023 15:58:04 GMT, Andrew Haley <aph at openjdk.org> wrote:

>> Some buggy libraries corrupt the floating-point control register. Provide something similar to the x86 RestoreMXCSROnJNICalls. 
>> 
>> I realize that using the x86ish name "RestoreMXCSROnJNICalls" might be a little controversial, but it is a _global_ flag, not a CPU-specific one. And it's clearly intended for this purpose. It might have been better if that flag had been given a better name twentyish years ago, but we can't change it now.
>
> Andrew Haley has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Fix thinko

Looks good.

I looked at https://help.totalview.io/previous_releases/2019/HTML/index.html#page/Reference_Guide%2FPowerFPSCRRegister_2.html%23, and there seems to be another exception bit, bit 15, the "Input denormal exception enable". That one is okay to be modified?

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Marked as reviewed by stuefe (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/16851#pullrequestreview-1764652762