2 files changed, 24 insertions, 13 deletions

diff --git a/src/ir/cost.h b/src/ir/cost.h
index 0c5a13819..b71e1ea0e 100644
--- a/src/ir/cost.h
+++ b/src/ir/cost.h
@@ -586,12 +586,21 @@ struct CostAnalyzer : public OverriddenVisitor<CostAnalyzer, Index> {
     return 1 + nullCheckCost(curr->ref) + visit(curr->ref);
   }
   Index visitStructSet(StructSet* curr) {
-    return 1 + nullCheckCost(curr->ref) + visit(curr->ref) + visit(curr->value);
+    return 2 + nullCheckCost(curr->ref) + visit(curr->ref) + visit(curr->value);
+  }
+  Index visitArrayNew(ArrayNew* curr) {
+    return 4 + visit(curr->rtt) + visit(curr->size) + visit(curr->init);
+  }
+  Index visitArrayGet(ArrayGet* curr) {
+    return 1 + nullCheckCost(curr->ref) + visit(curr->ref) + visit(curr->index);
+  }
+  Index visitArraySet(ArraySet* curr) {
+    return 2 + nullCheckCost(curr->ref) + visit(curr->ref) +
+           visit(curr->index) + visit(curr->value);
+  }
+  Index visitArrayLen(ArrayLen* curr) {
+    return 1 + nullCheckCost(curr->ref) + visit(curr->ref);
   }
-  Index visitArrayNew(ArrayNew* curr) { WASM_UNREACHABLE("TODO: GC"); }
-  Index visitArrayGet(ArrayGet* curr) { WASM_UNREACHABLE("TODO: GC"); }
-  Index visitArraySet(ArraySet* curr) { WASM_UNREACHABLE("TODO: GC"); }
-  Index visitArrayLen(ArrayLen* curr) { WASM_UNREACHABLE("TODO: GC"); }
 
 private:
   Index nullCheckCost(Expression* ref) {
diff --git a/src/ir/effects.h b/src/ir/effects.h
index e4907b082..94387c2cf 100644
--- a/src/ir/effects.h
+++ b/src/ir/effects.h
@@ -556,8 +556,7 @@ private:
     }
     void visitRttCanon(RttCanon* curr) {}
     void visitRttSub(RttSub* curr) {}
-    void visitStructNew(StructNew* curr) {
-    }
+    void visitStructNew(StructNew* curr) {}
     void visitStructGet(StructGet* curr) {
       // traps when the arg is null
       if (curr->ref->type.isNullable()) {
@@ -570,17 +569,20 @@ private:
         parent.implicitTrap = true;
       }
     }
-    void visitArrayNew(ArrayNew* curr) {
-      WASM_UNREACHABLE("TODO (gc): array.new");
-    }
+    void visitArrayNew(ArrayNew* curr) {}
     void visitArrayGet(ArrayGet* curr) {
-      WASM_UNREACHABLE("TODO (gc): array.get");
+      // traps when the arg is null or the index out of bounds
+      parent.implicitTrap = true;
     }
     void visitArraySet(ArraySet* curr) {
-      WASM_UNREACHABLE("TODO (gc): array.set");
+      // traps when the arg is null or the index out of bounds
+      parent.implicitTrap = true;
     }
     void visitArrayLen(ArrayLen* curr) {
-      WASM_UNREACHABLE("TODO (gc): array.len");
+      // traps when the arg is null
+      if (curr->ref->type.isNullable()) {
+        parent.implicitTrap = true;
+      }
     }
   };