8360000: RISC-V: implement aot

[Hamlin-Li]

Hi,
Can you help to review this patch?

https://openjdk.org/jeps/483 introduced aot (class loading/linking) and subsequent prs introduced more features related to it, like preserve adapters(c2i/i2c) and runtime blobs in AOT code cache.

Riscv should support these features and resolve relative issues.

Test

jtreg

run tier1/2/3 and hotspot_cds tests, no new failure found compared to master jdk.

Performance

perf command to run the simplest Hello world java program:

• (perf stat -r 100 ${JAVA_HOME}/bin/java -XX:AOTCache=$AOT_CACHE -cp $CLASS_PATH Hello > /dev/null) 2>&1 | grep elapsed

perf data:

• (with patch): 0.181730 +- 0.000296 seconds time elapsed ( +- 0.16% )
• (without patch): 0.196627 +- 0.000227 seconds time elapsed ( +- 0.12% )

Thanks

---

Progress

• Change must be properly reviewed (1 review required, with at least 1 Reviewer)
• Change must not contain extraneous whitespace
• Commit message must refer to an issue

Issue

• JDK-8360000: RISC-V: implement aot (Sub-task - P4)

Reviewing

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$ git fetch https://git.openjdk.org/jdk.git pull/26101/head:pull/26101
$ git checkout pull/26101

Update a local copy of the PR:
$ git checkout pull/26101
$ git pull https://git.openjdk.org/jdk.git pull/26101/head

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Checkout this PR locally:
$ git pr checkout 26101

View PR using the GUI difftool:
$ git pr show -t 26101

Using diff file

Download this PR as a diff file:
https://git.openjdk.org/jdk/pull/26101.diff

Using Webrev

Link to Webrev Comment

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[openjdk]

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[mlbridge]

Webrevs

• 01: Full - Incremental (bc05a32f)
• 00: Full (b70493e2)

[RealFYang]

Hi, Thanks for working on enabling this feature.

[RealFYang]

I noticed that our aarch64 counterpart puts the address of msg into r0 in #24740.

  // load msg into r0 so we can access it from the signal handler
  // ExternalAddress enables saving and restoring via the code cache
  lea(c_rarg0, ExternalAddress((address) str));

And fetches the address from r0 in PosixSignals::pd_hotspot_signal_handler:

        // A pointer to the message will have been placed in `r0`
        const char *detail_msg = (const char *)(uc->uc_mcontext.regs[0]);

I am not sure but I guess this is needed for the correct working of aot? Maybe we should do similar things.

[Hamlin-Li]

My test shows that it's fine to keep the current way to pass the stop message to sig handler, in both dump and use time. Seems currently both ways work.
But to keep the consistency with other platforms, I'll change it too.