RFR: 8342882: RISC-V: Unify handling of jumps to runtime

[Robbin Ehn]

On Wed, 23 Oct 2024 10:20:10 GMT, Fei Yang <fyang at openjdk.org> wrote:

> This fixes and unifies handling of jumps to runtime. Was previously discussed here [1]. ( Tagging @robehn )
> Seems not reasonable for `MacroAssembler::j(const Address &dest, Register temp)` to directly delegate work to `MacroAssembler::j(const address dest, Register temp)` for literal Address. This could generate a plain `JAL`, which means when we relocate the code, but the `JAL` immediate could be too large. This relaxes this constaint.
> 
> [1] https://github.com/openjdk/jdk/pull/21406#issuecomment-2415965656
> 
> Simply did a native fastdebug build and tried specjbb2005 workload.
> More testing in progress on linux-riscv64.
> - [ ] tier1 - tier3 (release)
> - [ ] tier1 (fastdebug)

Thanks, looks good!

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Marked as reviewed by rehn (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/21661#pullrequestreview-2388250735