[jdk21u] Integrated: 8316396: Endless loop in C2 compilation triggered by AddNode::IdealIL

[Aleksey Shipilev]

On Mon, 16 Oct 2023 19:32:21 GMT, Aleksey Shipilev <shade at openjdk.org> wrote:

> Clean backport to fix potential C2 problem. "Potential", because neither of fuzzer tests from the issue, nor the new regression test actually triggers the issue. I suppose that is because some other C2 optimization/bugfix is missing. However, it seems profitable to protect from this issue in 21u as well. @TobiHartmann, do you agree?
> 
> Additional testing:
>  - [x] macos-aarch64-server-fastdebug, new regression test passes before and after the patch
>  - [x] linux-aarch64-server-fastdebug, `tier1 tier2 tier3`

This pull request has now been integrated.

Changeset: 876f78e3
Author:    Aleksey Shipilev <shade at openjdk.org>
URL:       https://git.openjdk.org/jdk21u/commit/876f78e312c7c89b6698b3152a5bb69989bbbc21
Stats:     70 lines in 2 files changed: 68 ins; 0 del; 2 mod

8316396: Endless loop in C2 compilation triggered by AddNode::IdealIL

Reviewed-by: thartmann
Backport-of: b0d6c8472f69fef0265b41a4caf9e564adf68f6e

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PR: https://git.openjdk.org/jdk21u/pull/259