On Thu, 22 Jan 2026 15:50:12 GMT, Damon Fenacci <[email protected]> wrote:
> # Issue > > The Valhalla test > `compiler/valhalla/inlinetypes/TestArrayCopy.java#AlwaysIncrementalInline` > crashes intermittently in `ProjNode::adr_type()` when asserting `adr_type != > nullptr`. > > # Cause > > We are in the process of cleaning up an unreacheable subgraph and we get to a > situation like this one: > > <img width="427" height="336" alt="Screenshot 2026-01-20 at 19 57 31" > src="https://github.com/user-attachments/assets/c040b647-0858-4cc9-af68-5a1b05cc58fb"; > /> > > We have a Tuple node with top inputs followed by memory projection. Later in > the same ideal loop, while running Ideal for the `MemoryMerge` node, we query > the type of its memory Proj input, which skips the Tuple here: > > https://github.com/openjdk/valhalla/blob/b2f45e0f857fb32bdc36e7b93346ebc967b74736/src/hotspot/share/opto/multnode.cpp#L151-L154 > > and returns its corresponding input (`2`), which is top (and its `adr_type` > returns `nullptr`) > > # Fix > > We should probably check for `ctrl` being top (for this situation) > additionally to `nullptr`. > > # Testing > > Tier 1-3+ > Failing test before and after. It needs copyright update. I'll look again on Monday. ------------- PR Review: https://git.openjdk.org/valhalla/pull/1944#pullrequestreview-3699154017
