Stream: git-wasmtime

Topic: wasmtime / PR #13688 Cranelift: Fold branch-to-trap optim...

Wasmtime GitHub notifications bot (Jun 18 2026 at 15:25):

fitzgen opened PR #13688 from fitzgen:branch-to-trap-in-egraph-pass to bytecodealliance:main:

The last thing that the legalization pass did was branch-to-trap optimization, where a conditional branch to a block that just unconditionally traps was replaced with a trapz or trapnz. This commit moves this optimization into the egraph pass via:

• Making the branch-to-trap analysis compute its results for a given block on-demand (and memoize its results) so that traversal order doesn't matter.

• Adding a SimplifySkeletonInst::ReplaceWithTwo variant to replace a skeleton instruction with two other instructions.

• Adding two new simplify_skeleton ISLE rules that use results from the branch-to-trap analysis and the ReplaceWithTwo variant to perform the rewrite.

The legalizer and its filetest infrastructure is completely removed.

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Wasmtime GitHub notifications bot (Jun 18 2026 at 15:25):

fitzgen requested cfallin for a review on PR #13688.

Wasmtime GitHub notifications bot (Jun 18 2026 at 15:25):

fitzgen requested wasmtime-compiler-reviewers for a review on PR #13688.

Wasmtime GitHub notifications bot (Jun 18 2026 at 15:25):

fitzgen requested wasmtime-core-reviewers for a review on PR #13688.

Wasmtime GitHub notifications bot (Jun 18 2026 at 17:09):

fitzgen updated PR #13688.

Wasmtime GitHub notifications bot (Jun 18 2026 at 19:12):

:thumbs_up: cfallin submitted PR review:

Looks great -- thanks!

Wasmtime GitHub notifications bot (Jun 18 2026 at 19:12):

cfallin added PR #13688 Cranelift: Fold branch-to-trap optimization into the egraphs pass to the merge queue.

Wasmtime GitHub notifications bot (Jun 18 2026 at 19:37):

:check: cfallin merged PR #13688.

Wasmtime GitHub notifications bot (Jun 18 2026 at 19:37):

cfallin removed PR #13688 Cranelift: Fold branch-to-trap optimization into the egraphs pass from the merge queue.

Last updated: Jul 29 2026 at 05:03 UTC