GC: Add ref.eq instruction (#3145)

With `eqref` now integrated, the `ref.eq` instruction can be implemented. The only valid LHS and RHS value is `(ref.null eq)` for now, but implementation and fuzzer integration is otherwise complete.

1 files changed, 16 insertions, 0 deletions

diff --git a/src/wasm/wasm-validator.cpp b/src/wasm/wasm-validator.cpp
index 16ba60d72..c1df740df 100644
--- a/src/wasm/wasm-validator.cpp
+++ b/src/wasm/wasm-validator.cpp
@@ -330,6 +330,7 @@ public:
   void visitMemoryGrow(MemoryGrow* curr);
   void visitRefIsNull(RefIsNull* curr);
   void visitRefFunc(RefFunc* curr);
+  void visitRefEq(RefEq* curr);
   void visitTry(Try* curr);
   void visitThrow(Throw* curr);
   void visitRethrow(Rethrow* curr);
@@ -1957,6 +1958,21 @@ void FunctionValidator::visitRefFunc(RefFunc* curr) {
   shouldBeTrue(!!func, curr, "function argument of ref.func must exist");
 }
 
+void FunctionValidator::visitRefEq(RefEq* curr) {
+  shouldBeTrue(
+    getModule()->features.hasGC(), curr, "ref.eq requires gc to be enabled");
+  shouldBeSubTypeOrFirstIsUnreachable(
+    curr->left->type,
+    Type::eqref,
+    curr->left,
+    "ref.eq's left argument should be a subtype of eqref");
+  shouldBeSubTypeOrFirstIsUnreachable(
+    curr->right->type,
+    Type::eqref,
+    curr->right,
+    "ref.eq's right argument should be a subtype of eqref");
+}
+
 void FunctionValidator::visitTry(Try* curr) {
   if (curr->type != Type::unreachable) {
     shouldBeSubTypeOrFirstIsUnreachable(