RFR: 8346836: C2: Introduce a way to verify the correctness of ConstraintCastNodes at runtime [v8]

Tue Apr 8 21:41:10 UTC 2025

On Tue, 8 Apr 2025 20:15:46 GMT, Quan Anh Mai <qamai at openjdk.org> wrote:

>> Hi,
>> 
>> This patch adds a develop flag `VerifyConstraintCasts`, which will verify the correctness of `CastIINode`s and `CastLLNode`s at runtime and crash the VM if the dynamic value lies outside the type value range.
>> 
>> Please take a look, thanks a lot.
>
> Quan Anh Mai has updated the pull request incrementally with one additional commit since the last revision:
> 
>   reviews

Looks good.

Speaking of bug synopsis, can you make it a bit more concrete and succinct?

How about "C2: Verify CastII/CastLL bounds at runtime"?

src/hotspot/cpu/x86/x86_64.ad line 431:

> 429: source %{
> 430: 
> 431: bool castLL_is_imm32(const Node* n) {

Please, assert that n is CastLL.

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Marked as reviewed by vlivanov (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/22880#pullrequestreview-2751463910
PR Comment: https://git.openjdk.org/jdk/pull/22880#issuecomment-2787721137
PR Review Comment: https://git.openjdk.org/jdk/pull/22880#discussion_r2034066958