JDK-8369979 : Flag UsePopCountInstruction was accidentally disabled on PPC64
  • Type: Bug
  • Component: hotspot
  • Sub-Component: compiler
  • Affected Version: 25,26
  • Priority: P4
  • Status: Resolved
  • Resolution: Fixed
  • CPU: ppc
  • Submitted: 2025-10-16
  • Updated: 2025-10-24
  • Resolved: 2025-10-17
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JDK 25 JDK 26
25.0.2Fixed 26 b21Fixed
Related Reports
Causes :  
JDK-8331859 - [PPC64] Remove support for Power7 and older
Description
In JDK-8331859 the PPC flag UsePopCountInstruction was accidentally removed when removing Power 7 support.

This was discovered by a test from JDK-8365205 that was added recently.

The flag needs to be reenabled in src/hotspot/cpu/ppc/vm_version_ppc.cpp.
Comments
[jdk25u-fix-request] Approval Request from David Linus Briemann This fixes a regression introduced by JDK-8331859 in JDK25. Fix is trivial and applies cleanly. Tier1-Tier4 have passed.
21-10-2025
A pull request was submitted for review. Branch: master URL: https://git.openjdk.org/jdk25u/pull/326 Date: 2025-10-20 11:00:29 +0000
20-10-2025
Changeset: 9b9559a2 Branch: master Author: David Briemann <dbriemann@openjdk.org> Date: 2025-10-17 08:59:55 +0000 URL: https://git.openjdk.org/jdk/commit/9b9559a2e33827126e1aeab7bf6f4861acaae109
17-10-2025
A pull request was submitted for review. Branch: master URL: https://git.openjdk.org/jdk/pull/27843 Date: 2025-10-16 10:01:13 +0000
16-10-2025