8343242: RISC-V: Refactor materialization of literal address

[RealFYang]

Hi, please consider this refactoring work.

Currently, we have both la(address) and la(Address). They both accept and materialize literal address.
While la(Address) always emit a movptr sequence, la(address) is a bit complex: it checks whether the target is
reachable from anywhere within the code cache (is_32bit_offset_from_codecache) and emits pc-relative auipc+addi
pair or movptr sequence. This makes it not that obvious at places where we want a more accurate estimation about
the size of code emitted like when we prepare code stubs like C2SafepointPollStub or C2EntryBarrierStub (See: #21732).

I would suggest we keep la(address) simple and let it only emit auipc+addi pair, which will be consistent with the
RISC-V Assembly Programmer's Handbook. I think It's more reasonable to move the distance check to la(Address).
Furthermore, I would also suggest that we make the distance check simpler. The approach taken here is to only check
whether the target is inside the code cache. This way we will be more certain about code emitted with la(Address)
as well. This will help keep the risk of this change low as all la(Address) callsites with literal address outside of code
cache won't be affected. And I don't think the original distance check from code cache will benefit us much more.
Eyeballed all la(Address) callsites, I think we are fine.

Benefits:

1. We have a simpler la(address) which is kind of spec compatible;
2. We are consistent in target distance check when doing j(Address), la(Address), ld/st(Address) and rt_call;
3. We don't need explicit use of relocate with lambda for most of the places;

Note that there are several places where we want explicit movptr sequence:

1. In SignatureHandlerGenerator::generate() where the emitted code is simply copied without relocation [1];
2. In movoop and mov_metadata where we want patching afterwards;

[1] https://github.com/openjdk/jdk/blob/master/src/hotspot/share/interpreter/interpreterRuntime.cpp#L1313

Testing on linux-riscv64:

• hotspot:tier1 (fastdebug)
• tier1-tier3, hotspot:tier4 (release)
• specjbb2015, dacapo, renaissance (release)

---

Progress

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Issue

• JDK-8343242: RISC-V: Refactor materialization of literal address (Enhancement - P4)

Reviewers

• Robbin Ehn (@robehn - Reviewer)
• Feilong Jiang (@feilongjiang - Committer)

Reviewing

Using git

Checkout this PR locally:
$ git fetch https://git.openjdk.org/jdk.git pull/21777/head:pull/21777
$ git checkout pull/21777

Update a local copy of the PR:
$ git checkout pull/21777
$ git pull https://git.openjdk.org/jdk.git pull/21777/head

Using Skara CLI tools

Checkout this PR locally:
$ git pr checkout 21777

View PR using the GUI difftool:
$ git pr show -t 21777

Using diff file

Download this PR as a diff file:
https://git.openjdk.org/jdk/pull/21777.diff

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[bridgekeeper]

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[openjdk]

@RealFYang This change now passes all automated pre-integration checks.

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After integration, the commit message for the final commit will be:

8343242: RISC-V: Refactor materialization of literal address

Reviewed-by: rehn, fjiang

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At the time when this comment was updated there had been 15 new commits pushed to the master branch:

• 00ec105: 8343412: Missing escapes for single quote marks in javac.properties
• 8c1cf8f: 8339128: Cannot resolve user specified tool properly after JDK-8338304
• 3c7082a: 8343419: Assertion failure in long vector unsigned min/max with -XX:+UseKNLSetting
• c82ad84: 8342183: Update tests to use stronger algorithms and keys
• 1eccdfc: 8343439: [JVMCI] Fix javadoc of Services.getSavedProperties
• ea110c3: 8343236: Use @APinote and @implSpec in j.util.Currency
• 5995786: 8343177: JFR: Remove critical section for thread id assignment
• 751a914: 8340733: Add scope for relaxing constraint on JavaCalls from CompilerThread
• 7e87c07: 8340116: test/jdk/sun/security/tools/jarsigner/PreserveRawManifestEntryAndDigest.java can fail due to regex
• da0e9e3: 8343333: Parallel: Cleanup comment referring Solaris in MutableNUMASpace
• ... and 5 more: https://git.openjdk.org/jdk/compare/cbda758010c22b0c1b9aec16004d4bfd24ab5c81...master

As there are no conflicts, your changes will automatically be rebased on top of these commits when integrating. If you prefer to avoid this automatic rebasing, please check the documentation for the /integrate command for further details.

➡️ To integrate this PR with the above commit message to the master branch, type /integrate in a new comment.

[openjdk]

@RealFYang The following labels will be automatically applied to this pull request:

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[RealFYang]

/label remove graal

[openjdk]

@RealFYang
The graal label was successfully removed.

[mlbridge]

Webrevs

• 01: Full (6a52ea55)
• 00: Full (8e96a1a5)

[robehn]

Hi, I agree with the sentiment of the CR.

Thinking about the is_32bit_offset_from_codecache vs CodeCache::contains change.

[RealFYang]

Hi, I agree with the sentiment of the CR.

Thinking about the is_32bit_offset_from_codecache vs CodeCache::contains change.

Thanks! Note that I didn't remove this is_32bit_offset_from_codecache routine as I am guessing that we might find a better way of using this check after this change.

[robehn]

Did you run any micro benchmarks? Maybe skynet just to check VTs.
And did you do any measurement on code cache size?

I can't find anything that would matter, but I'll look a bit more.

[RealFYang]

Did you run any micro benchmarks? Maybe skynet just to check VTs. And did you do any measurement on code cache size?

No obvious change witnessed on Skynet JMH with this change. Let me know if there are others we might want a try.

And did you do any measurement on code cache size?

Good suggestion. I just tried dacapo and renaissance with -XX:+PrintCodeCache -XX:-TieredCompilation and compared the max_used of code cache. I didn't see a big difference with this change either.

I can't find anything that would matter, but I'll look a bit more.

Thanks. I merged master. Take your time!

[robehn]

Looks good, thanks!

[feilongjiang]

It looks much cleaner now. Thank you!

[RealFYang]

@robehn @feilongjiang : Thanks for the review! I also tried NetBeans and Eclipse. Both IDEs work fine with this change. Let's move on.
/integrate

[openjdk]

Going to push as commit 37a3398.
Since your change was applied there have been 18 commits pushed to the master branch:

• d26412e: 8343433: Update net.properties and java.net.http module-info.java after 8326949
• 29882bf: 8340311: JPackage app-image exe launches multiple exe's in JDK 22+
• 069bb79: 8342082: Remove unused BasicProgressBarUI.Animator.interval
• 00ec105: 8343412: Missing escapes for single quote marks in javac.properties
• 8c1cf8f: 8339128: Cannot resolve user specified tool properly after JDK-8338304
• 3c7082a: 8343419: Assertion failure in long vector unsigned min/max with -XX:+UseKNLSetting
• c82ad84: 8342183: Update tests to use stronger algorithms and keys
• 1eccdfc: 8343439: [JVMCI] Fix javadoc of Services.getSavedProperties
• ea110c3: 8343236: Use @APinote and @implSpec in j.util.Currency
• 5995786: 8343177: JFR: Remove critical section for thread id assignment
• ... and 8 more: https://git.openjdk.org/jdk/compare/cbda758010c22b0c1b9aec16004d4bfd24ab5c81...master

Your commit was automatically rebased without conflicts.

[openjdk]

@RealFYang Pushed as commit 37a3398.

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