[jdk11u-dev] RFR: 8288445: AArch64: C2 compilation fails with guarantee(!true || (true && (shift != 0))) failed: impossible encoding

[Paul Hohensee]

On Tue, 18 Oct 2022 16:05:28 GMT, William Kemper <wkemper at openjdk.org> wrote:

> [JDK-8288445](https://bugs.openjdk.org/browse/JDK-8288445)
> AArch64: C2 compilation fails with guarantee(!true || (true && (shift != 0))) failed: impossible encoding
> 
> Backport is not clean, but is not complicated. Some of the instructions patched in later releases do not exist in 11. The test passes _before_ and _after_ the patch is applied.

Lgtm. Even though the test succeeds without the backport, probably because something in C2 is masking the problem, imo it's good code hygiene to fix it.

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Marked as reviewed by phh (Reviewer).

PR: https://git.openjdk.org/jdk11u-dev/pull/1462