ref.null func ✅ — Produces a null funcref For the function-reference hierarchy ref.null extern — ✅ Produces a null externref For the external-reference hierarchy ref.func $f ✅ — Produces a non-null reference to $f The function must be declared for reference use ref.is_null ✅ ✅ Produces i32 1 for null, otherwise 0 ref.as_non_null ✅ ✅ Converts nullable reference to non-null reference Traps when the operand is null ref.eq ✅ ✅ Produces i32 identity comparison Both operands must satisfy the instruction’s reference-type constraints; it does not inspect their contents ref.test <type> ✅ Limited Produces i32 Runtime type test; mainly useful with typed function and GC reference hierarchies ref.cast <type> ✅ Limited Produces a narrowed reference Traps if the runtime type does not match drop ✅ ✅ Discards the reference Works on every value type select ✅ ✅ Selects one of two references Both alternatives must have a compatible type select (result <reftype>) ✅ ✅ Typed selection Explicit result type local.get ✅ ✅ Reads a local reference Local must have the corresponding reference type local.set ✅ ✅ Writes a local reference local.tee ✅ ✅ Writes and retains the reference global.get ✅ ✅ Reads a global reference global.set ✅ ✅ Writes a mutable global reference Global must be mutable table.get ✅ ✅ Reads a reference from a table Table element type must be compatible table.set ✅ ✅ Writes a reference into a table table.grow ✅ ✅ Grows a table using a reference as the initial value Returns the old size or -1 table.fill ✅ ✅ Fills table entries with a reference table.copy ✅ ✅ Copies references between tables Source and destination element types must be compatible table.init ✅ ✅ Initializes a table from an element segment Element segment type must be compatible table.size ✅ ✅ Produces the table size Does not operate on an individual reference value elem.drop ✅ ✅ Discards an element segment Does not operate on an individual reference value call_indirect ✅ ❌ Calls the referenced function from a table Performs a runtime signature check return_call_indirect ✅ ❌ Tail-calls a function from a table Requires tail-call support call_ref ✅ ❌ Calls a typed function reference directly Requires a typed function reference, not merely an unrefined funcref return_call_ref ✅ ❌ Tail-calls a typed function reference Typed function references plus tail calls Function parameter passing ✅ ✅ Passes a reference into a function Works for Wasm-defined and imported functions Function result ✅ ✅ Returns a reference Works for Wasm-defined and imported functions call / imported call ✅ ✅ May consume or produce references According to the callee’s declared signature return ✅ ✅ Returns reference-typed results According to the current function signature br ✅ ✅ Transfers references as label arguments According to the target block type br_if ✅ ✅ Conditionally transfers references br_table ✅ ✅ Transfers references to one of several labels All target label types must be compatible block, loop, if parameters/results ✅ ✅ Carries references through structured control flow Reference types can appear in block signatures Import/export ✅ ✅ Exchanges references across the host boundary Subject to the embedding API any.convert_extern ❌ ✅ input Converts externref to an internal anyref representation GC/reference conversion; does not reveal the host object extern.convert_any ❌ ✅ output Converts an internal anyref back to externref Inverse of any.convert_extern