JDK-8233743 : AArch64: Make r27 conditionally allocatable
  • Type: Enhancement
  • Component: hotspot
  • Sub-Component: compiler
  • Affected Version: 14
  • Priority: P4
  • Status: Resolved
  • Resolution: Fixed
  • OS: linux
  • CPU: aarch64
  • Submitted: 2019-11-07
  • Updated: 2025-01-16
  • Resolved: 2019-12-24
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Resolved: Release in which this issue/RFE has been resolved.
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JDK 15
15 b04Fixed
Related Reports
Relates :  
JDK-8231754 - [JVMCI] Make r27 unconditionally reserved in JVMCI
Relates :  
JDK-8242449 - AArch64: r27 can be allocated in CompressedOops mode
Relates :  
JDK-8217909 - Make unused r12 register (without compressed oops) available to regalloc in C2
Relates :  
JDK-8347917 - AArch64: Enable upper GPR registers in C1
Description
We should do a follow-up patch of JDK-8217909 to make the AArch64 r27 register allocatable when compressed oops is turned off.

And JDK-8231754 for AArch64 should be reverted if this is done.
Comments
Rejecting 11u fix request as this seems too obtrusive and bears to much risk for destabilization of the maintenance release.
26-10-2021
Fix Request (11u): This is the only prerequisite for backporting JDK-8242449. JVMCI and ZGC parts from original patch were removed for 11u. PR: https://github.com/openjdk/jdk11u-dev/pull/136
25-10-2021
URL: https://hg.openjdk.java.net/jdk/jdk/rev/f0634d11b7de User: njian Date: 2019-12-24 08:54:29 +0000
24-12-2019
Review thread: http://mail.openjdk.java.net/pipermail/hotspot-compiler-dev/2019-December/036612.html
24-12-2019