RFR: 8330094: RISC-V: Save and restore FCSR in the call stub [v3]

[Fei Yang]

On Mon, 15 Apr 2024 16:30:14 GMT, Hamlin Li <mli at openjdk.org> wrote:

>> Hi,
>> Can you help to review this patch?
>> As discussed at https://github.com/openjdk/jdk/pull/17745#discussion_r1558783467, we should do the similar thing as [JDK-8319973](https://bugs.openjdk.org/browse/JDK-8319973) on aarch64.
>> Thanks!
>> 
>> Tests running ...
>
> Hamlin Li has updated the pull request incrementally with one additional commit since the last revision:
> 
>   refine code

src/hotspot/cpu/riscv/stubGenerator_riscv.cpp line 304:

> 302:     __ frrm(t0);
> 303:     __ sd(t0, frm_save);
> 304:     // Set fcsr to the state we need. We do want Round to Nearest. We

I think it will be more accurate to mention `frm` instead of `fcsr` both in code comment and the JBS title?

src/hotspot/cpu/riscv/stubGenerator_riscv.cpp line 308:

> 306:     Label skip_fsrmi;
> 307:     guarantee(__ RoundingMode::rne == 0, "must be");
> 308:     __ beq(t0, zr, skip_fsrmi);

Suggestion: `__ beqz(t0, skip_fsrmi);`

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PR Review Comment: https://git.openjdk.org/jdk/pull/18758#discussion_r1568181960
PR Review Comment: https://git.openjdk.org/jdk/pull/18758#discussion_r1568180315