8287394: AArch64: Remove cbuf parameter from far_call/far_jump/trampoline_call

[eastig]

far_call/far_jump/trampoline_call have parameter cbuf with the default value NULL. We always call far_call/far_jump with NULL. We call trampoline_call with either NULL or the CodeBuffer currently used by MacroAssembler. If not NULL we mark a trampoline call position.

Andrew Haley(@theRealAph) in #8564 (comment) suggests to remove it.

This PR removes the parameter. In the case of trampoline_call we explicitly return the position of the generated trampoline calls. All places using the position of the generated trampoline call are updated.

Tested with release and fastdebug builds:

• gtest: Passed.
• tier1/tier2: Passed.

---

Progress

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Issue

• JDK-8287394: AArch64: Remove cbuf parameter from far_call/far_jump/trampoline_call

Reviewers

• Andrew Haley (@theRealAph - Reviewer)

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[openjdk]

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[mlbridge]

Webrevs

• 00: Full (6c46ba32)

[theRealAph]

Thanks.

[openjdk]

@eastig 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:

8287394: AArch64: Remove cbuf parameter from far_call/far_jump/trampoline_call

Reviewed-by: 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 18 new commits pushed to the master branch:

• 1e1db5d: 8292591: Experimentally add back barrier-less Java thread transitions
• dfc16e0: 8292302: Windows GetLastError value overwritten by ThreadLocalStorage::thread
• 8bd79d3: 8170305: URLConnection doesn't handle HTTP/1.1 1xx (informational) messages
• 9cd3e35: 4834298: JFileChooser.getSelectedFiles() failed with multi-selection and double-click
• ec2629c: 8275275: AArch64: Fix performance regression after auto-vectorization on NEON
• cbee0bc: 8292587: AArch64: Support SVE fabd instruction
• 68645eb: 8293566: RISC-V: Clean up push and pop registers
• 526eb54: 8293669: SA: Remove unnecssary "InstanceStackChunkKlass: InstanceStackChunkKlass" output when scanning heap
• 41ce658: 8292225: Rename ArchiveBuilder APIs related to source and buffered addresses
• 155b10a: 8293329: x86: Improve handling of constants in AES/GHASH stubs
• ... and 8 more: https://git.openjdk.org/jdk/compare/37df5f56259429482cfdbe38e8b6256f1efaf9e8...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.

[eastig]

/integrate

[openjdk]

Going to push as commit 9039022.
Since your change was applied there have been 22 commits pushed to the master branch:

• 1dc5039: 8293626: AccessFlag::locations(ClassFileFormatVersion cffv) does not throw NPEx when parameter is null
• 6f2223f: 8288180: C2: VectorPhase must ensure that SafePointNode memory input is a MergeMemNode
• 725f41f: 8293351: Add second tmp register to aarch64 BarrierSetAssembler::load_at
• 37234c8: 8291912: Introduce per-allocation target struct for members in G1PLABAllocator
• 1e1db5d: 8292591: Experimentally add back barrier-less Java thread transitions
• dfc16e0: 8292302: Windows GetLastError value overwritten by ThreadLocalStorage::thread
• 8bd79d3: 8170305: URLConnection doesn't handle HTTP/1.1 1xx (informational) messages
• 9cd3e35: 4834298: JFileChooser.getSelectedFiles() failed with multi-selection and double-click
• ec2629c: 8275275: AArch64: Fix performance regression after auto-vectorization on NEON
• cbee0bc: 8292587: AArch64: Support SVE fabd instruction
• ... and 12 more: https://git.openjdk.org/jdk/compare/37df5f56259429482cfdbe38e8b6256f1efaf9e8...master

Your commit was automatically rebased without conflicts.

[openjdk]

@eastig Pushed as commit 9039022.

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

[feilongjiang]

Hi @eastig, I'm doing the same cleanup on riscv port, and I noticed that you also removed clear_inst_mark() in aarch64_enc_java_static_call and aarch64_enc_java_to_runtime.
Seems it was related to the removing of cbuf in trampoline_call, but there is still one clear_inst_mark() in aarch64_enc_java_dynamic_call [1].
So I dig into the ic_call and find out that it calls trampoline_call at last. If I was understanding correctly, it could be removed too, right?

[1]

jdk/src/hotspot/cpu/aarch64/aarch64.ad

Lines 3661 to 3674 in eeb625e

	enc_class aarch64_enc_java_dynamic_call(method meth) %{
	C2_MacroAssembler _masm(&cbuf);
	int method_index = resolved_method_index(cbuf);
	address call = __ ic_call((address)$meth$$method, method_index);
	if (call == NULL) {
	ciEnv::current()->record_failure("CodeCache is full");
	return;
	}
	_masm.clear_inst_mark();
	__ post_call_nop();
	if (Compile::current()->max_vector_size() > 0) {
	__ reinitialize_ptrue();
	}
	%}

[eastig]

Hi @feilongjiang,

So I dig into the ic_call and find out that it calls trampoline_call at last. If I was understanding correctly, it could be removed too, right?

Yes, you are right. It should be deleted as well.
Thank you for the finding.

[eastig]

I created https://bugs.openjdk.org/browse/JDK-8293856.