Index: unittests/ExecutionEngine/Orc/LLJITTest.cpp
===================================================================
--- unittests/ExecutionEngine/Orc/LLJITTest.cpp
+++ unittests/ExecutionEngine/Orc/LLJITTest.cpp
@@ -128,7 +128,7 @@
   JITEvaluatedSymbol BarSym = cantFail(Jit->lookup(Extra1, "bar"));
   EXPECT_EQ(1, Exec(BarSym));
 
-  // Allow buz to resolve foo and bar from the other dylibs:
+  // Allow buz to resolve foo and bar from the other dylibs.
   Extra2.addToSearchOrder(Main);
   Extra2.addToSearchOrder(Extra1);
 
@@ -150,9 +150,9 @@
   for (size_t i = 0; i < 3; i++)
     cantFail(Jit->addIRModule(parseIR(Bs[i], E, Cs[i])));
 
-  // Dispatch compile job to different threads.
+  // Dispatch compile jobs to different threads.
   std::vector<std::thread> Ms;
-  static constexpr size_t MaxMaterializerThreads = 3;
+  static constexpr size_t MaxMaterializerThreads = 4;
   Ms.reserve(MaxMaterializerThreads);
 
   ES.setDispatchMaterialization(
@@ -165,6 +165,18 @@
           SMU->doMaterialize(JD);
         });
       });
+  
+  /*
+  // FIXME: Trying to run this before the other functions always causes a
+  // deadlock.
+  Ts.emplace_back([&Jit]() {
+    JITEvaluatedSymbol BuzSym = cantFail(Jit->lookup("buz"));
+    EXPECT_EQ(2, Exec(BuzSym)); // Automatically waits for materializer.
+  });
+  
+  JoinAll(Ts);
+  JoinAll(Ms); // FIXME: Ideally this happened in the individual runner threads.
+  */
 
   // Run functions in different threads.
   Ts.emplace_back([&Jit]() {
@@ -179,15 +191,15 @@
   
   // FIXME: Lookup for "buz" can't run in parallel.
   JoinAll(Ts);
-  JoinAll(Ms);
+  JoinAll(Ms); // This should happen in the above runner threads.
 
   Ts.emplace_back([&Jit]() {
     JITEvaluatedSymbol BuzSym = cantFail(Jit->lookup("buz"));
     EXPECT_EQ(2, Exec(BuzSym)); // Automatically waits for materializer.
   });
-
+  
   JoinAll(Ts);
-  JoinAll(Ms);
+  JoinAll(Ms); // FIXME: Ideally this happened in the individual runner threads.
 }
 
 //===----------------------------------------------------------------------===//
@@ -211,9 +223,9 @@
   for (size_t i = 0; i < 3; i++)
     cantFail(Jit->addIRModule(*Ds[i], parseIR(Bs[i], E, Cs[i])));
 
-  // Dispatch compile job to different threads.
+  // Dispatch compile jobs to different threads.
   std::vector<std::thread> Ms;
-  static constexpr size_t MaxMaterializerThreads = 3;
+  static constexpr size_t MaxMaterializerThreads = 4; // one more than necessary
   Ms.reserve(MaxMaterializerThreads);
 
   ES.setDispatchMaterialization(
@@ -227,6 +239,22 @@
         });
       });
 
+  // Allow buz to resolve foo and bar from the other dylibs.
+  Extra2.addToSearchOrder(Main);
+  Extra2.addToSearchOrder(Extra1);
+
+  /*
+  // FIXME: Trying to run this before the other functions always causes a
+  // deadlock.
+  Ts.emplace_back([&]() {
+    JITEvaluatedSymbol BuzSym = cantFail(Jit->lookup(Extra2, "buz"));
+    EXPECT_EQ(2, Exec(BuzSym)); // Automatically waits for materializer.
+  });
+  
+  JoinAll(Ts);
+  JoinAll(Ms); // FIXME: Ideally this happened in the individual runner threads.
+  */
+
   // Run functions in different threads.
   Ts.emplace_back([&]() {
     JITEvaluatedSymbol FooSym = cantFail(Jit->lookup("foo"));
@@ -238,19 +266,12 @@
     EXPECT_EQ(1, Exec(BarSym)); // Automatically waits for materializer.
   });
   
-  // FIXME: Lookup for "buz" can't run in parallel.
-  JoinAll(Ts);
-  JoinAll(Ms);
-
-  // Allow buz to resolve foo and bar from the other dylibs.
-  Extra2.addToSearchOrder(Main);
-  Extra2.addToSearchOrder(Extra1);
-
+  // Lookup for "buz" works in parallel here even without a barrier.
   Ts.emplace_back([&]() {
     JITEvaluatedSymbol BuzSym = cantFail(Jit->lookup(Extra2, "buz"));
     EXPECT_EQ(2, Exec(BuzSym)); // Automatically waits for materializer.
   });
 
   JoinAll(Ts);
-  JoinAll(Ms);
+  JoinAll(Ms); // FIXME: Ideally this happened in the individual runner threads.
 }