[jdk25u-dev] RFR: 8362979: C2 fails with unexpected node in SuperWord truncation: CmpLTMask, RoundF

[duke]

On Wed, 4 Feb 2026 22:43:04 GMT, Vishal Chand <duke at openjdk.org> wrote:

> Clean backport of [8362979](https://github.com/openjdk/jdk/pull/26494): C2 fails with unexpected node in SuperWord truncation: CmpLTMask, RoundF
> 
> This backport fixes a debug assert failure discovered by CTW. The fix adds CmpLTMask, RoundF, and RoundD nodes to the SuperWord truncation switch statement and includes reduced test cases.
> 
> 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 ba4667961caf2d06f7e47f4af3172cd1782bdc9e) is now ready to be sponsored by a Committer.

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PR Comment: https://git.openjdk.org/jdk25u-dev/pull/232#issuecomment-3887695707