2 files changed, 25 insertions, 2 deletions
diff --git a/src/passes/NameTypes.cpp b/src/passes/NameTypes.cpp
index fcf6df5ab..0e18f3094 100644
--- a/src/passes/NameTypes.cpp
+++ b/src/passes/NameTypes.cpp
@@ -34,13 +34,36 @@ struct NameTypes : public Pass {
     // Find all the types.
     std::vector<HeapType> types = ModuleUtils::collectHeapTypes(*module);
 
+    std::unordered_set<Name> used;
+
     // Ensure simple names. If a name already exists, and is short enough, keep
     // it.
     size_t i = 0;
     for (auto& type : types) {
       if (module->typeNames.count(type) == 0 ||
           module->typeNames[type].name.size() >= NameLenLimit) {
-        module->typeNames[type].name = "type$" + std::to_string(i++);
+        module->typeNames[type].name = "type_" + std::to_string(i++);
+      }
+      used.insert(module->typeNames[type].name);
+    }
+
+    // "Lint" the names a little. In particular a name with a "_7" or such
+    // suffix, as TypeSSA creates, can be removed if it does not cause a
+    // collision. This keeps the names unique while removing 'noise.'
+    //
+    // Note we must iterate in a deterministic order here, so do it on |types|.
+    for (auto& type : types) {
+      auto& names = module->typeNames[type];
+      std::string name = names.name.toString();
+      while (name.size() > 1 && isdigit(name.back())) {
+        name.pop_back();
+      }
+      if (name.size() > 1 && name.back() == '_') {
+        name.pop_back();
+        if (!used.count(name)) {
+          names.name = name;
+          used.insert(name);
+        }
       }
     }
   }
diff --git a/src/passes/TypeSSA.cpp b/src/passes/TypeSSA.cpp
index cb8f0f049..6c50cb2a9 100644
--- a/src/passes/TypeSSA.cpp
+++ b/src/passes/TypeSSA.cpp
@@ -285,7 +285,7 @@ struct TypeSSA : public Pass {
 
       // If the old type has a nice name, make a nice name for the new one.
       if (typeNames.count(oldType)) {
-        auto intendedName = typeNames[oldType].name.toString() + '$' +
+        auto intendedName = typeNames[oldType].name.toString() + '_' +
                             std::to_string(++nameCounter);
         auto newName =
           Names::getValidNameGivenExisting(intendedName, existingTypeNames);