RFR: 8288445: AArch64: C2 compilation fails with guarantee(!true || (true && (shift != 0))) failed: impossible encoding [v5]

Dean Long dlong at openjdk.org
Fri Jun 24 07:34:57 UTC 2022


> The range for aarch64 vector right-shift is 1 to the element width.  This issue fixes the problem in the back-end.  There is a separate problem in the front-end that shift by 0 is not always optimized out.

Dean Long has updated the pull request incrementally with one additional commit since the last revision:

  Update test/hotspot/jtreg/compiler/codegen/ShiftByZero.java
  
  Co-authored-by: Hao Sun <hao.sun at arm.com>

-------------

Changes:
  - all: https://git.openjdk.org/jdk19/pull/40/files
  - new: https://git.openjdk.org/jdk19/pull/40/files/583c54c0..f4761fbf

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk19&pr=40&range=04
 - incr: https://webrevs.openjdk.org/?repo=jdk19&pr=40&range=03-04

  Stats: 1 line in 1 file changed: 0 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/jdk19/pull/40.diff
  Fetch: git fetch https://git.openjdk.org/jdk19 pull/40/head:pull/40

PR: https://git.openjdk.org/jdk19/pull/40


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