JDK-8319777 : Zero: Support 8-byte cmpxchg
  • Type: Enhancement
  • Component: hotspot
  • Sub-Component: runtime
  • Affected Version: 22
  • Priority: P4
  • Status: Resolved
  • Resolution: Fixed
  • Submitted: 2023-11-09
  • Updated: 2024-02-08
  • Resolved: 2023-11-20
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JDK 21 JDK 22
21.0.3Fixed 22 b25Fixed
Related Reports
Blocks :  
JDK-8319883 - Zero: Use atomic built-ins for 64-bit accesses
Blocks :  
JDK-8318776 - Require supports_cx8 to always be true
Relates :  
JDK-8320582 - Zero: Misplaced CX8 enablement flag
Description
See related discussion in JDK-8318776.

I think we can claim Zero is supports_cx8() = true, because we have enough fallbacks for 8-byte CASes to work. Note that some code already reaches for these without checking for supports_cx8(), so the proverbial horses have already left the barn.
Comments
A pull request was submitted for review. URL: https://git.openjdk.org/jdk21u-dev/pull/232 Date: 2024-02-03 10:09:53 +0000
07-02-2024
[jdk21u-fix-request] Approval Request from Aleksey Shipilëv 8320582 Clean followup to JDK-8319777. Zero testing passes.
07-02-2024
Changeset: 6b96bb64 Author: Aleksey Shipilev <shade@openjdk.org> Date: 2023-11-20 19:05:57 +0000 URL: https://git.openjdk.org/jdk/commit/6b96bb640aa91d96877b8ceea5fed359607c1e45
20-11-2023
A pull request was submitted for review. URL: https://git.openjdk.org/jdk/pull/16614 Date: 2023-11-10 14:17:32 +0000
13-11-2023