Stream: git-wasmtime

Topic: wasmtime / PR #13609 [gc_fuzz]: Add and complete i31

Wasmtime GitHub notifications bot (Jun 10 2026 at 19:32):

khagankhan opened PR #13609 from khagankhan:i32-eqref to bytecodealliance:main:

Add i31ref support and eqref upcasts to the gc_ops fuzzer

Extends the gc_ops fuzz generator (which previously covered externref,
structref, and eqref) with i31ref and abstract-eqref upcasts.

• i31ref fields/locals/globals/tables — new FieldType::I31Ref, plus an
  i31 local, global, and table threaded through the encoded module.

• New ops:

  • NullI31, RefI31 { value } — create i31 references.
  • I31LocalGet/Set, I31GlobalGet/Set, I31TableGet/Set.

  • I31GetS / I31GetU — null-guarded (these instructions trap on null,
    which the oracle would otherwise reject).

  • StructRefAsEq, TypedStructRefAsEq { type_index }, I31RefAsEq — upcast
    abstract/concrete struct refs and i31 refs to abstract eqref (implicit
    Wasm subtyping; no instruction emitted, only the abstract stack type
    changes).

• Host imports: new take_i31 import (the existing take_eq already
  covered eqref).

• Differential check: TakeI31Call passes the i31ref plus the guest's
  inline i31.get_s / i31.get_u results to the host, which re-derives them
  (I31::get_i32() / get_u32()) and asserts they match the Wasm
  instructions.

+cc @fitzgen @eeide

Wasmtime GitHub notifications bot (Jun 10 2026 at 19:32):

khagankhan requested wasmtime-fuzz-reviewers for a review on PR #13609.

Wasmtime GitHub notifications bot (Jun 10 2026 at 19:32):

khagankhan requested alexcrichton for a review on PR #13609.

Wasmtime GitHub notifications bot (Jun 10 2026 at 19:33):

alexcrichton requested fitzgen for a review on PR #13609.

Wasmtime GitHub notifications bot (Jun 10 2026 at 19:33):

alexcrichton unassigned alexcrichton from PR #13609 [gc_fuzz]: Add and complete i31.

Wasmtime GitHub notifications bot (Jun 10 2026 at 20:56):

:thumbs_up: fitzgen submitted PR review:

Thanks!

Wasmtime GitHub notifications bot (Jun 10 2026 at 20:56):

:speech_balloon: fitzgen created PR review comment:

I added a new misc. item to https://github.com/bytecodealliance/wasmtime/issues/10327 as a follow up, because it doesn't need to happen in this PR, but we should really support multiple locals/globals/tables for the various types we are working with.

Wasmtime GitHub notifications bot (Jun 10 2026 at 20:57):

fitzgen added PR #13609 [gc_fuzz]: Add and complete i31 to the merge queue.

Wasmtime GitHub notifications bot (Jun 10 2026 at 21:21):

github-merge-queue[bot] removed PR #13609 [gc_fuzz]: Add and complete i31 from the merge queue.

Wasmtime GitHub notifications bot (Jun 10 2026 at 21:26):

khagankhan commented on PR #13609:

Working on the failure

Wasmtime GitHub notifications bot (Jun 10 2026 at 21:42):

khagankhan updated PR #13609.

Wasmtime GitHub notifications bot (Jun 10 2026 at 21:59):

khagankhan commented on PR #13609:

Should be good

Wasmtime GitHub notifications bot (Jun 10 2026 at 22:28):

:thumbs_up: fitzgen submitted PR review.

Wasmtime GitHub notifications bot (Jun 10 2026 at 22:28):

fitzgen added PR #13609 [gc_fuzz]: Add and complete i31 to the merge queue.

Wasmtime GitHub notifications bot (Jun 10 2026 at 22:47):

github-merge-queue[bot] removed PR #13609 [gc_fuzz]: Add and complete i31 from the merge queue.

Wasmtime GitHub notifications bot (Jun 10 2026 at 22:50):

khagankhan commented on PR #13609:

@fitzgen I assume the new failure is not related to our changes in this PR?

Wasmtime GitHub notifications bot (Jun 11 2026 at 00:06):

github-actions[bot] added the label fuzzing on PR #13609.

Wasmtime GitHub notifications bot (Jun 11 2026 at 00:06):

github-actions[bot] commented on PR #13609:

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cc @fitzgen

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Wasmtime GitHub notifications bot (Jun 11 2026 at 05:10):

fitzgen added PR #13609 [gc_fuzz]: Add and complete i31 to the merge queue.

Wasmtime GitHub notifications bot (Jun 11 2026 at 05:32):

:check: fitzgen merged PR #13609.

Wasmtime GitHub notifications bot (Jun 11 2026 at 05:32):

fitzgen removed PR #13609 [gc_fuzz]: Add and complete i31 from the merge queue.

Last updated: Jul 29 2026 at 05:03 UTC