[jdk25u-dev] RFR: 8365570: C2 fails assert(false) failed: Unexpected node in SuperWord truncation: CastII

[duke]

On Sat, 14 Feb 2026 07:58:36 GMT, Vishal Chand <duke at openjdk.org> wrote:

> Clean backport of [8365570](https://github.com/openjdk/jdk/commit/775f48de6129092d05650fec17dad171944e6d89) - C2 fails assert(false) failed: Unexpected node in SuperWord truncation: CastII
> 
> *  Fixes assert failure in superword truncation with CastII. Since casts specifically change the type of a node, they should not be truncated during vectorization to maintain type safety.
> 
> * Additional Testing:
> 
> - [x]  New regression test fails without the fix, passes with it.
> - [x]  Linux x86_64 server fastebug compiler tests.

@vish-chan 
Your change (at version 76da8720dd47ebdab4a2c4bbc655879432f688c0) is now ready to be sponsored by a Committer.

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

PR Comment: https://git.openjdk.org/jdk25u-dev/pull/269#issuecomment-3953962119