8358655: AArch64: Simplify Interpreter::profile_taken_branch

[chadrako]

JDK-8358655

The aarch64 version of JDK-8357434

The counter is 64-bit, never practically overflows, and no other code cares about it so it is safe to remove

Additional Testing:

• Linux aarch64 fastdebug tier 1
• Linux aarch64 fastdebug tier 2
• Linux aarch64 fastdebug tier 3
• Linux aarch64 fastdebug tier 4

---

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-8358655: AArch64: Simplify Interpreter::profile_taken_branch (Enhancement - P4)

Reviewers

• Andrew Haley (@theRealAph - Reviewer) Review applies to ae31d0fb
• Aleksey Shipilev (@shipilev - Reviewer)

Reviewing

Using git

Checkout this PR locally:
$ git fetch https://git.openjdk.org/jdk.git pull/25906/head:pull/25906
$ git checkout pull/25906

Update a local copy of the PR:
$ git checkout pull/25906
$ git pull https://git.openjdk.org/jdk.git pull/25906/head

Using Skara CLI tools

Checkout this PR locally:
$ git pr checkout 25906

View PR using the GUI difftool:
$ git pr show -t 25906

Using diff file

Download this PR as a diff file:
https://git.openjdk.org/jdk/pull/25906.diff

Using Webrev

Link to Webrev Comment

[bridgekeeper]

👋 Welcome back chadrako! 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]

@chadrako 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:

8358655: AArch64: Simplify Interpreter::profile_taken_branch

Reviewed-by: shade, aph

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 1 new commit pushed to the master branch:

• 6df0f5e: 8360281: VMError::error_string has incorrect format usage

Please see this link for an up-to-date comparison between the source branch of this pull request and the master branch.
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[openjdk]

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

• hotspot-compiler

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[mlbridge]

Webrevs

• 02: Full - Incremental (29cd0043)
• 01: Full - Incremental (c2d5ef37)
• 00: Full (ae31d0fb)

[shipilev]

Looks fine. I also think r1 saves are now unnecessary, right, @theRealAph?

    // ECN: FIXME: This code smells
    // check if MethodCounters exists
    Label has_counters;
    __ ldr(rscratch1, Address(rmethod, Method::method_counters_offset()));
    __ cbnz(rscratch1, has_counters);
    __ push(r0);
    __ push(r1); // <--- here
    __ push(r2);
    __ call_VM(noreg, CAST_FROM_FN_PTR(address,
            InterpreterRuntime::build_method_counters), rmethod);
    __ pop(r2);
    __ pop(r1);  // <--- here
    __ pop(r0);

[theRealAph]

Looks fine. I also think r1 saves are now unnecessary, right, @theRealAph?

    // ECN: FIXME: This code smells
    // check if MethodCounters exists
    Label has_counters;
    __ ldr(rscratch1, Address(rmethod, Method::method_counters_offset()));
    __ cbnz(rscratch1, has_counters);
    __ push(r0);
    __ push(r1); // <--- here
    __ push(r2);
    __ call_VM(noreg, CAST_FROM_FN_PTR(address,
            InterpreterRuntime::build_method_counters), rmethod);
    __ pop(r2);
    __ pop(r1);  // <--- here
    __ pop(r0);

I thinks so, but at a first glance r1 seems to be clobbered on all code paths immediately after this, so I don't think it's needed anyway,

[shipilev]

Looks okay, as long as it still passes testing.

[chadrako]

Looks okay, as long as it still passes testing.

Linux jtreg tests I ran passed. Windows GHA actions is failing but seems unrelated

configure:110212: error: Could not find a C compiler.

[shipilev]

Windows GHA is fixed by 72679c9, you can pull from master, and it should fix it.

[chadrako]

/integrate

[openjdk]

@chadrako
Your change (at version 29cd004) is now ready to be sponsored by a Committer.

[sendaoYan]

/sponsor

[openjdk]

Going to push as commit a350a11.
Since your change was applied there have been 3 commits pushed to the master branch:

• bcad87e: 8358697: TextLayout/MyanmarTextTest.java passes if no Myanmar font is found
• 2a70a6d: 8346886: Add since checker test to jdk.management.jfr
• 6df0f5e: 8360281: VMError::error_string has incorrect format usage

Your commit was automatically rebased without conflicts.

[openjdk]

@sendaoYan @chadrako Pushed as commit a350a11.

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