8308915: RISC-V: Improve temporary vector register usage avoiding the use of v0

[DingliZhang]

We have some macro assembler functions that use v0 hardcoded as a temporary
register currently.

However, the mask value used to control execution of a masked vector
instruction is always supplied by vector register v0 in RVV1.0[1]. If v0 is
alive holding a mask value the the same time, this will cause spilling of
this vector register. So it is better to replace v0 with other vector registers to
improve code execution efficiency.

In addition, this pr also adds several missing spaces in the format of the
instructions, and fixes several pipeline classes.

[1] https://github.com/riscv/riscv-v-spec/blob/v1.0/v-spec.adoc

Testing:

QEMU w/ UseRVV:

• Tier1 tests (release)
• Tier2 tests (release)
• Tier3 tests (release)
• test/jdk/jdk/incubator/vector (fastdebug)

---

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-8308915: RISC-V: Improve temporary vector register usage avoiding the use of v0

Reviewers

• Yanhong Zhu (@yhzhu20 - Author) ⚠️ Review applies to 05446b0a
• Fei Yang (@RealFYang - Reviewer) ⚠️ Review applies to 05446b0a

Reviewing

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Checkout this PR locally:
$ git fetch https://git.openjdk.org/jdk.git pull/14166/head:pull/14166
$ git checkout pull/14166

Update a local copy of the PR:
$ git checkout pull/14166
$ git pull https://git.openjdk.org/jdk.git pull/14166/head

Using Skara CLI tools

Checkout this PR locally:
$ git pr checkout 14166

View PR using the GUI difftool:
$ git pr show -t 14166

Using diff file

Download this PR as a diff file:
https://git.openjdk.org/jdk/pull/14166.diff

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[bridgekeeper]

👋 Welcome back dzhang! A progress list of the required criteria for merging this PR into master will be added to the body of your pull request. There are additional pull request commands available for use with this pull request.

[openjdk]

@DingliZhang The following label will be automatically applied to this pull request:

• hotspot-compiler

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[mlbridge]

Webrevs

• 01: Full - Incremental (9fea08dc)
• 00: Full (05446b0a)

[yhzhu20]

LGTM.

[RealFYang]

Looks fine.

[openjdk]

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

ℹ️ This project also has non-automated pre-integration requirements. Please see the file CONTRIBUTING.md for details.

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

8308915: RISC-V: Improve temporary vector register usage avoiding the use of v0

Reviewed-by: yzhu, fyang

You can use pull request commands such as /summary, /contributor and /issue to adjust it as needed.

At the time when this comment was updated there had been 19 new commits pushed to the master branch:

• 547a8b4: 8306560: Add TOOLING.jsh load file
• ca54f4e: 8306428: RunThese30M.java crashed with assert(early->flag() == current->flag() || early->flag() == mtNone)
• 5fdb22f: 8308876: JFR: Deserialization of EventTypeInfo uses incorrect attribute names
• bd113ee: 8308814: extend SetLocalXXX minimal support for virtual threads
• a923634: 8286470: Support searching for sections in class/package javadoc
• 55d297f: 8308594: Use atomic bitset function for PackageEntry::_defined_by_cds_in_class_path
• c72b547: 8308801: update for deprecated sprintf for libnet in java.base
• 77c5adb: 8308935: jdk.management.jfr.RecordingInfo.toString() lacks test coverage
• ce5251a: 8308657: ReplayInline is not availabe in production build
• cc0976b: 8308589: gc/cslocker/TestCSLocker.java timed out
• ... and 9 more: https://git.openjdk.org/jdk/compare/46c4da7fddb8103934f2a90b4456a5ce6ed3467c...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.

As you do not have Committer status in this project an existing Committer must agree to sponsor your change. Possible candidates are the reviewers of this PR (@RealFYang) but any other Committer may sponsor as well.

➡️ To flag this PR as ready for integration with the above commit message, type /integrate in a new comment. (Afterwards, your sponsor types /sponsor in a new comment to perform the integration).

[DingliZhang]

@RealFYang @yhzhu20 Thanks for the review!
/integrate

[openjdk]

@DingliZhang
Your change (at version 9fea08d) is now ready to be sponsored by a Committer.

[RealFYang]

/sponsor

[openjdk]

Going to push as commit e21f865.
Since your change was applied there have been 19 commits pushed to the master branch:

• 547a8b4: 8306560: Add TOOLING.jsh load file
• ca54f4e: 8306428: RunThese30M.java crashed with assert(early->flag() == current->flag() || early->flag() == mtNone)
• 5fdb22f: 8308876: JFR: Deserialization of EventTypeInfo uses incorrect attribute names
• bd113ee: 8308814: extend SetLocalXXX minimal support for virtual threads
• a923634: 8286470: Support searching for sections in class/package javadoc
• 55d297f: 8308594: Use atomic bitset function for PackageEntry::_defined_by_cds_in_class_path
• c72b547: 8308801: update for deprecated sprintf for libnet in java.base
• 77c5adb: 8308935: jdk.management.jfr.RecordingInfo.toString() lacks test coverage
• ce5251a: 8308657: ReplayInline is not availabe in production build
• cc0976b: 8308589: gc/cslocker/TestCSLocker.java timed out
• ... and 9 more: https://git.openjdk.org/jdk/compare/46c4da7fddb8103934f2a90b4456a5ce6ed3467c...master

Your commit was automatically rebased without conflicts.

[openjdk]

@RealFYang @DingliZhang Pushed as commit e21f865.

💡 You may see a message that your pull request was closed with unmerged commits. This can be safely ignored.