AArch64: Use dmb limitation enum #20188
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This commit replaces the use of magic numbers for the limitation immediate for dmb instructions with the AArch64BarrierLimitation enum. Signed-off-by: Spencer Comin <[email protected]>
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Internal JDK11 sanity.functional testing: https://hyc-runtimes-jenkins.swg-devops.com/job/Pipeline-Build-Test-Personal/23966/ |
knn-k
reviewed
Sep 19, 2024
| @@ -97,7 +97,7 @@ void J9::ARM64::JNILinkage::releaseVMAccess(TR::Node *callNode, TR::Register *vm | |||
| // Arm Architecture Reference Manual states: | |||
| // "This architecture assumes that all PEs that use the same operating system or hypervisor are in the same Inner Shareable shareability domain" | |||
| // thus, inner shareable dmb suffices | |||
| generateSynchronizationInstruction(cg(), TR::InstOpCode::dmb, callNode, 0xb); | |||
| generateSynchronizationInstruction(cg(), TR::InstOpCode::dmb, callNode, TR::InstOpCode::ishst); | |||
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0xb means TR::InstOpCode::ish, while the comments above says dmb ishst.
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Would a dmb ishst be sufficient for the spin lock implementation here?
Looking at the example spin lock implementation in the Arm Architecture Reference Manual (Appendix K 14.3.1), I wonder if we could replace the dmb with a prfm and relax the ldxrx to a ldaxrx.
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Actually, is the dmb necessary given that we are using ldxrx to read the lock?
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Jenkins test sanity.functional,sanity.system alinux64,amac jdk17 depends eclipse/omr#7465 |
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This commit replaces the use of magic numbers for the limitation immediate for dmb instructions with the
AArch64BarrierLimitationenum.NOTE: Requires coordinated merge with eclipse/omr#7465