1 files changed, 1 insertions, 20 deletions
diff --git a/src/passes/Vacuum.cpp b/src/passes/Vacuum.cpp
index 1b0887181..bb005e36c 100644
--- a/src/passes/Vacuum.cpp
+++ b/src/passes/Vacuum.cpp
@@ -25,13 +25,11 @@
 
 namespace wasm {
 
-struct Vacuum : public WalkerPass<PostWalker<Vacuum, Visitor<Vacuum>>> {
+struct Vacuum : public WalkerPass<ExpressionStackWalker<Vacuum, Visitor<Vacuum>>> {
   bool isFunctionParallel() override { return true; }
 
   Pass* create() override { return new Vacuum; }
 
-  std::vector<Expression*> expressionStack;
-
   // returns nullptr if curr is dead, curr if it must stay as is, or another node if it can be replaced
   Expression* optimize(Expression* curr, bool resultUsed) {
     while (1) {
@@ -206,23 +204,6 @@ struct Vacuum : public WalkerPass<PostWalker<Vacuum, Visitor<Vacuum>>> {
     }
   }
 
-  static void visitPre(Vacuum* self, Expression** currp) {
-    self->expressionStack.push_back(*currp);
-  }
-
-  static void visitPost(Vacuum* self, Expression** currp) {
-    self->expressionStack.pop_back();
-  }
-
-  // override scan to add a pre and a post check task to all nodes
-  static void scan(Vacuum* self, Expression** currp) {
-    self->pushTask(visitPost, currp);
-
-    WalkerPass<PostWalker<Vacuum, Visitor<Vacuum>>>::scan(self, currp);
-
-    self->pushTask(visitPre, currp);
-  }
-
   void visitFunction(Function* curr) {
     auto* optimized = optimize(curr->body, curr->result != none);
     if (optimized) {