RFR: 8351468: C2: array fill optimization assigns wrong type to intrinsic call

[Roberto Castañeda Lozano]

On Mon, 17 Mar 2025 09:44:09 GMT, Roberto Castañeda Lozano <rcastanedalo at openjdk.org> wrote:

> > The alternative of using `memory_type()` and introducing a `StoreS` node assumes for correctness that the array fill optimization does not succeed for mismatched stores such as those you mention (e.g. `StoreS` into a `char[]`).
> 
> After some more thought, I lean towards just disabling the `OptimizeFill` optimization for mismatched stores. It does not succeed today anyway due to accidental reasons (brittleness in pattern matching), so disabling it for this case should not have any other impact than making us more confident in the correctness of the optimization.

Done now, and also added a set of positive and negative test cases (commit 38c9b475) and updated the PR description. @merykitty hopefully this addresses your concerns, please let me know what you think.

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

PR Comment: https://git.openjdk.org/jdk/pull/24005#issuecomment-2733076258