RFR: 8358892: RISC-V: jvm crash when running dacapo sunflow after JDK-8352504 [v11]

[Fei Yang]

On Fri, 13 Jun 2025 13:07:27 GMT, Hamlin Li <mli at openjdk.org> wrote:

>> Hi,
>> Can you help to review this patch?
>> 
>> Thanks!
>> 
>> Currently, this issue is only reproducible with Dacapo sunflow.
>> I tried to construct a simpler jtreg test to reproduce the issue, but can not find a way to do it till now, this task is tracked by https://bugs.openjdk.org/browse/JDK-8359045.
>> 
>> So, currently I can only verify the code by reviewing it.
>> Or maybe it's better to leave it until we find the test?
>
> Hamlin Li has updated the pull request incrementally with two additional commits since the last revision:
> 
>  - remove log
>  - refine comments

src/hotspot/cpu/riscv/macroAssembler_riscv.cpp line 1276:

> 1274: //
> 1275: // Set dst (CMoveI (Binary cop (CmpF/D op1 op2)) (Binary dst src))
> 1276: //    1. (op1 lt NaN) => true  => CMove: dst = src

I think you can rename `NaN` to `op2` and add some words before this like: `If one or both inputs to the compare is a NaN,`.

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PR Review Comment: https://git.openjdk.org/jdk/pull/25696#discussion_r2145060874