8337780: RISC-V: C2: Change C calling convention for sp to NS

[feilongjiang]

Hi, please review this patch that changes the C calling convention for sp to NS as sp is always saved and restored by the prolog/epilog code..
This could reduce the frame size by 16 bytes for those C2 runtime stubs [1] as we do not have to save sp on the method entry.

I also checked the calling convention type for sp on other platforms (AArch64, PPC, x86, x64, S390), and they are all treated as NS.

Testing:

• tier1~3 & hotspot:tier4 with release build

1:

jdk/src/hotspot/share/opto/runtime.cpp

Lines 147 to 167 in 367e0a6

	gen(env, _new_instance_Java , new_instance_Type , new_instance_C , 0 , true, false);
	gen(env, _new_array_Java , new_array_Type , new_array_C , 0 , true, false);
	gen(env, _new_array_nozero_Java , new_array_Type , new_array_nozero_C , 0 , true, false);
	gen(env, _multianewarray2_Java , multianewarray2_Type , multianewarray2_C , 0 , true, false);
	gen(env, _multianewarray3_Java , multianewarray3_Type , multianewarray3_C , 0 , true, false);
	gen(env, _multianewarray4_Java , multianewarray4_Type , multianewarray4_C , 0 , true, false);
	gen(env, _multianewarray5_Java , multianewarray5_Type , multianewarray5_C , 0 , true, false);
	gen(env, _multianewarrayN_Java , multianewarrayN_Type , multianewarrayN_C , 0 , true, false);
	#if INCLUDE_JVMTI
	gen(env, _notify_jvmti_vthread_start , notify_jvmti_vthread_Type , SharedRuntime::notify_jvmti_vthread_start, 0, true, false);
	gen(env, _notify_jvmti_vthread_end , notify_jvmti_vthread_Type , SharedRuntime::notify_jvmti_vthread_end, 0, true, false);
	gen(env, _notify_jvmti_vthread_mount , notify_jvmti_vthread_Type , SharedRuntime::notify_jvmti_vthread_mount, 0, true, false);
	gen(env, _notify_jvmti_vthread_unmount , notify_jvmti_vthread_Type , SharedRuntime::notify_jvmti_vthread_unmount, 0, true, false);
	#endif
	gen(env, _complete_monitor_locking_Java , complete_monitor_enter_Type , SharedRuntime::complete_monitor_locking_C, 0, false, false);
	gen(env, _monitor_notify_Java , monitor_notify_Type , monitor_notify_C , 0 , false, false);
	gen(env, _monitor_notifyAll_Java , monitor_notify_Type , monitor_notifyAll_C , 0 , false, false);
	gen(env, _rethrow_Java , rethrow_Type , rethrow_C , 2 , true , true );
	gen(env, _slow_arraycopy_Java , slow_arraycopy_Type , SharedRuntime::slow_arraycopy_C , 0 , false, false);
	gen(env, _register_finalizer_Java , register_finalizer_Type , register_finalizer , 0 , false, false);

---

Progress

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• Commit message must refer to an issue

Issue

• JDK-8337780: RISC-V: C2: Change C calling convention for sp to NS (Enhancement - P4)

Reviewers

• Fei Yang (@RealFYang - Reviewer)
• Robbin Ehn (@robehn - Reviewer)

Reviewing

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Update a local copy of the PR:
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$ git pull https://git.openjdk.org/jdk.git pull/20449/head

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[bridgekeeper]

👋 Welcome back fjiang! 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]

@feilongjiang 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:

8337780: RISC-V: C2: Change C calling convention for sp to NS

Reviewed-by: fyang, rehn

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At the time when this comment was updated there had been 4 new commits pushed to the master branch:

• fbe8a81: 8333144: docker tests do not work when ubsan is configured
• dabdae6: 8334599: Improve code from JDK-8302671
• 8bd3cd5: 8337716: ByteBuffer hashCode implementations are inconsistent
• 367e0a6: 8334755: Asymptotically faster implementation of square root algorithm

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[openjdk]

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

• hotspot-compiler

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[mlbridge]

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• 00: Full (f52e8931)

[RealFYang]

Looks good. Thanks.

[robehn]

Thanks!

[feilongjiang]

@RealFYang @robehn -- Thanks for the review!
/integrate

[openjdk]

Going to push as commit 53db937.
Since your change was applied there have been 30 commits pushed to the master branch:

• ab509f1: 8337654: Relocate uncommon trap stub from SharedRuntime to OptoRuntime
• 1348ece: 8332120: Potential compilation failure in istream.cpp:205 - loss of data on conversion
• ef909bd: 8335121: Native memory leak when not recording any events
• a117945: 8337344: Redundant javadoc at RasterPrinterJob.isCancelled
• f9b8a22: 8337798: JFR: Remove jdk/jfr/api/consumer/recordingstream/TestOnEvent.java from ProblemList.txt
• 958786b: 8332522: SwitchBootstraps::mappedEnumLookup constructs unused array
• f92c60e: 8337810: ProblemList BasicDirectoryModel/LoaderThreadCount.java on Windows
• 0d8ec42: 8337642: Remove unused APIs of GCPolicyCounters
• 2057594: 8337782: Use THROW_NULL instead of THROW_0 in pointer contexts in prims code
• 73718fb: 8337788: RISC-V: Cleanup code in MacroAssembler::reserved_stack_check
• ... and 20 more: https://git.openjdk.org/jdk/compare/34edc7358f733cdf433d0ff50921bcb5a94c5e35...master

Your commit was automatically rebased without conflicts.

[openjdk]

@feilongjiang Pushed as commit 53db937.

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