diff --git a/src/compile.cpp b/src/compile.cpp
index 12189c216a..37374f03c0 100644
--- a/src/compile.cpp
+++ b/src/compile.cpp
@@ -5288,7 +5288,8 @@ calculateTryCatchRoots(Context* context, SubroutinePath* subroutinePath,
 
 unsigned
 calculateFrameMaps(MyThread* t, Context* context, uintptr_t* originalRoots,
-                   unsigned eventIndex, SubroutinePath* subroutinePath = 0)
+                   unsigned eventIndex, SubroutinePath* subroutinePath = 0,
+                   uintptr_t* resultRoots = 0)
 {
   // for each instruction with more than one predecessor, and for each
   // stack position, determine if there exists a path to that
@@ -5321,11 +5322,12 @@ calculateFrameMaps(MyThread* t, Context* context, uintptr_t* originalRoots,
     switch (e) {
     case PushContextEvent: {
       eventIndex = calculateFrameMaps
-        (t, context, RUNTIME_ARRAY_BODY(roots), eventIndex, subroutinePath);
+        (t, context, RUNTIME_ARRAY_BODY(roots), eventIndex, subroutinePath,
+         resultRoots);
     } break;
 
     case PopContextEvent:
-      return eventIndex;
+      goto exit;
 
     case IpEvent: {
       ip = context->eventLog.get2(eventIndex);
@@ -5491,18 +5493,41 @@ calculateFrameMaps(MyThread* t, Context* context, uintptr_t* originalRoots,
                          makeRootTable(t, &(context->zone), context->method));
       }
 
+      THREAD_RUNTIME_ARRAY(t, uintptr_t, subroutineRoots, mapSize);
+
       calculateFrameMaps
         (t, context, RUNTIME_ARRAY_BODY(roots), call->subroutine->logIndex,
-         path);
+         path, RUNTIME_ARRAY_BODY(subroutineRoots));
+
+      for (unsigned wi = 0; wi < mapSize; ++wi) {
+        RUNTIME_ARRAY_BODY(roots)[wi]
+          &= RUNTIME_ARRAY_BODY(subroutineRoots)[wi];
+      }      
     } break;
 
     case PopSubroutineEvent:
-      return static_cast<unsigned>(-1);
+      eventIndex = static_cast<unsigned>(-1);
+      goto exit;
 
     default: abort(t);
     }
   }
 
+ exit:
+  if (resultRoots and ip != -1) {
+    if (DebugFrameMaps) {
+      fprintf(stderr, "result roots at ip %3d: ", ip);
+      printSet(*RUNTIME_ARRAY_BODY(roots), mapSize);
+      if (subroutinePath) {
+        fprintf(stderr, " ");
+        print(subroutinePath);
+      }
+      fprintf(stderr, "\n");
+    }
+
+    memcpy(resultRoots, RUNTIME_ARRAY_BODY(roots), mapSize * BytesPerWord);
+  }
+
   return eventIndex;
 }
 
diff --git a/test/Subroutine.java b/test/Subroutine.java
index c44c5df8ef..b02ec9ba81 100644
--- a/test/Subroutine.java
+++ b/test/Subroutine.java
@@ -31,7 +31,7 @@ public class Subroutine {
     //  4:
     Stream.write1(out, Assembler.invokestatic);
     Stream.write2(out, ConstantPool.addMethodRef
-           (pool, "java/lang/System", "gc", "()V") + 1);
+                  (pool, "java/lang/System", "gc", "()V") + 1);
 
     //  7:
     Stream.write1(out, Assembler.goto_);
@@ -43,7 +43,7 @@ public class Subroutine {
     // 11:
     Stream.write1(out, Assembler.invokestatic);
     Stream.write2(out, ConstantPool.addMethodRef
-           (pool, "java/lang/System", "gc", "()V") + 1);
+                  (pool, "java/lang/System", "gc", "()V") + 1);
 
     // 14:
     Stream.write1(out, Assembler.ret);
@@ -56,7 +56,7 @@ public class Subroutine {
     // 19:
     Stream.write1(out, Assembler.invokestatic);
     Stream.write2(out, ConstantPool.addMethodRef
-           (pool, "java/lang/System", "gc", "()V") + 1);
+                  (pool, "java/lang/System", "gc", "()V") + 1);
 
     // 22:
     Stream.write1(out, Assembler.return_);
@@ -237,58 +237,58 @@ public class Subroutine {
   }
 
   public static void main(String[] args) throws Exception {
-    // test(false, false);
-    // test(false, true);
-    // test(true, false);
+    test(false, false);
+    test(false, true);
+    test(true, false);
 
-    // String.valueOf(test2(1));
-    // String.valueOf(test2(2));
-    // String.valueOf(test2(3));
+    String.valueOf(test2(1));
+    String.valueOf(test2(2));
+    String.valueOf(test2(3));
 
-    // String.valueOf(test3(1, 1, 1));
-    // String.valueOf(test3(2, 1, 1));
-    // String.valueOf(test3(3, 1, 1));
+    String.valueOf(test3(1, 1, 1));
+    String.valueOf(test3(2, 1, 1));
+    String.valueOf(test3(3, 1, 1));
 
-    // String.valueOf(test3(1, 2, 1));
-    // String.valueOf(test3(2, 2, 1));
-    // String.valueOf(test3(3, 2, 1));
+    String.valueOf(test3(1, 2, 1));
+    String.valueOf(test3(2, 2, 1));
+    String.valueOf(test3(3, 2, 1));
 
-    // String.valueOf(test3(1, 3, 1));
-    // String.valueOf(test3(2, 3, 1));
-    // String.valueOf(test3(3, 3, 1));
+    String.valueOf(test3(1, 3, 1));
+    String.valueOf(test3(2, 3, 1));
+    String.valueOf(test3(3, 3, 1));
 
-    // String.valueOf(test3(1, 1, 2));
-    // String.valueOf(test3(2, 1, 2));
-    // String.valueOf(test3(3, 1, 2));
+    String.valueOf(test3(1, 1, 2));
+    String.valueOf(test3(2, 1, 2));
+    String.valueOf(test3(3, 1, 2));
 
-    // String.valueOf(test3(1, 2, 2));
-    // String.valueOf(test3(2, 2, 2));
-    // String.valueOf(test3(3, 2, 2));
+    String.valueOf(test3(1, 2, 2));
+    String.valueOf(test3(2, 2, 2));
+    String.valueOf(test3(3, 2, 2));
 
-    // String.valueOf(test3(1, 3, 2));
-    // String.valueOf(test3(2, 3, 2));
-    // String.valueOf(test3(3, 3, 2));
+    String.valueOf(test3(1, 3, 2));
+    String.valueOf(test3(2, 3, 2));
+    String.valueOf(test3(3, 3, 2));
 
-    // String.valueOf(test3(1, 1, 3));
-    // String.valueOf(test3(2, 1, 3));
-    // String.valueOf(test3(3, 1, 3));
+    String.valueOf(test3(1, 1, 3));
+    String.valueOf(test3(2, 1, 3));
+    String.valueOf(test3(3, 1, 3));
 
-    // String.valueOf(test3(1, 2, 3));
-    // String.valueOf(test3(2, 2, 3));
-    // String.valueOf(test3(3, 2, 3));
+    String.valueOf(test3(1, 2, 3));
+    String.valueOf(test3(2, 2, 3));
+    String.valueOf(test3(3, 2, 3));
 
-    // String.valueOf(test3(1, 3, 3));
-    // String.valueOf(test3(2, 3, 3));
-    // String.valueOf(test3(3, 3, 3));
+    String.valueOf(test3(1, 3, 3));
+    String.valueOf(test3(2, 3, 3));
+    String.valueOf(test3(3, 3, 3));
 
-    // String.valueOf(test4(1));
-    // String.valueOf(test4(2));
-    // String.valueOf(test4(3));
+    String.valueOf(test4(1));
+    String.valueOf(test4(2));
+    String.valueOf(test4(3));
 
-    // expect(test4(1) == 0xFABFABFABFL);
+    expect(test4(1) == 0xFABFABFABFL);
 
-    // new Subroutine().test5(true);
-    // new Subroutine().test5(false);
+    new Subroutine().test5(true);
+    new Subroutine().test5(false);
 
     makeTestClass().getMethod("test", new Class[0]).invoke
       (null, new Object[0]);