Stream: git-wasmtime

Topic: wasmtime / PR #14063 Cranelift: Prevent DSE across diverg...

Wasmtime GitHub notifications bot (Aug 02 2026 at 14:13):

subotac opened PR #14063 from subotac:fix/dse-divergent-store to bytecodealliance:main:

Fixes #14053.

Cranelift's post-dominator tree only considers paths that reach an explicit CFG exit. Dead-store elimination could therefore treat an overwriting store as inevitable even when another path entered a divergent region,
where a trap could expose the earlier memory state.

Reject cross-block dead-store candidates when the original store can reach a divergent block without first passing through the overwriter. Add a CLIF regression covering the divergent path.

Testing:

- all 38 alias-analysis filetests
- all 187 cranelift-codegen unit tests
- 22 doctests
- cargo clippy -p cranelift-codegen --all-targets -- -D warnings
- original WAST reproducer from #14053

Wasmtime GitHub notifications bot (Aug 02 2026 at 14:13):

subotac requested wasmtime-compiler-reviewers for a review on PR #14063.

Wasmtime GitHub notifications bot (Aug 02 2026 at 14:13):

subotac requested alexcrichton for a review on PR #14063.

Wasmtime GitHub notifications bot (Aug 02 2026 at 16:03):

github-actions[bot] added the label cranelift on PR #14063.

Wasmtime GitHub notifications bot (Aug 02 2026 at 16:37):

alexcrichton unassigned alexcrichton from PR #14063 Cranelift: Prevent DSE across divergent paths.

Wasmtime GitHub notifications bot (Aug 02 2026 at 16:37):

alexcrichton requested fitzgen for a review on PR #14063.

Wasmtime GitHub notifications bot (Aug 05 2026 at 18:52):

:cross_mark: cfallin closed without merge PR #14063.

Wasmtime GitHub notifications bot (Aug 05 2026 at 18:52):

cfallin commented on PR #14063:

This is addressed in a more principled way in #14080; closing.

Last updated: Aug 30 2026 at 10:08 UTC