1 files changed, 8 insertions, 2 deletions
diff --git a/src/ir/cost.h b/src/ir/cost.h
index 268ac41b3..a006146d3 100644
--- a/src/ir/cost.h
+++ b/src/ir/cost.h
@@ -563,8 +563,14 @@ struct CostAnalyzer : public OverriddenVisitor<CostAnalyzer, Index> {
   Index visitRefTest(RefTest* curr) { WASM_UNREACHABLE("TODO: GC"); }
   Index visitRefCast(RefCast* curr) { WASM_UNREACHABLE("TODO: GC"); }
   Index visitBrOnCast(BrOnCast* curr) { WASM_UNREACHABLE("TODO: GC"); }
-  Index visitRttCanon(RttCanon* curr) { WASM_UNREACHABLE("TODO: GC"); }
-  Index visitRttSub(RttSub* curr) { WASM_UNREACHABLE("TODO: GC"); }
+  Index visitRttCanon(RttCanon* curr) {
+    // TODO: investigate actual RTT costs in VMs
+    return 1;
+  }
+  Index visitRttSub(RttSub* curr) {
+    // TODO: investigate actual RTT costs in VMs
+    return 2 + visit(curr->parent);
+  }
   Index visitStructNew(StructNew* curr) { WASM_UNREACHABLE("TODO: GC"); }
   Index visitStructGet(StructGet* curr) {
     return 1 + nullCheckCost(curr->ref) + visit(curr->ref);