optimize --vacuum a little

3 files changed, 10 insertions, 0 deletions

diff --git a/src/passes/Vacuum.cpp b/src/passes/Vacuum.cpp
index dfede6d25..863d78f14 100644
--- a/src/passes/Vacuum.cpp
+++ b/src/passes/Vacuum.cpp
@@ -20,6 +20,7 @@
 
 #include <wasm.h>
 #include <pass.h>
+#include <ast_utils.h>
 
 namespace wasm {
 
@@ -41,6 +42,13 @@ struct Vacuum : public WalkerPass<PostWalker<Vacuum, Visitor<Vacuum>>> {
     if (skip > 0) {
       list.resize(size - skip);
     }
+    if (!curr->name.is()) {
+      if (list.size() == 1) {
+        replaceCurrent(list[0]);
+      } else if (list.size() == 0) {
+        ExpressionManipulator::nop(curr);
+      }
+    }
   }
 };
 
diff --git a/test/unit.fromasm b/test/unit.fromasm
index 0a4b39d25..0b43f14fc 100644
--- a/test/unit.fromasm
+++ b/test/unit.fromasm
@@ -272,6 +272,7 @@
     )
   )
   (func $blocker
+    (nop)
   )
   (func $frem (result f64)
     (return
diff --git a/test/unit.fromasm.imprecise b/test/unit.fromasm.imprecise
index e146f60c4..f5ba55d90 100644
--- a/test/unit.fromasm.imprecise
+++ b/test/unit.fromasm.imprecise
@@ -266,6 +266,7 @@
     )
   )
   (func $blocker
+    (nop)
   )
   (func $frem (result f64)
     (return