diff --git a/lib/Target/ARM/ARMISelDAGToDAG.cpp b/lib/Target/ARM/ARMISelDAGToDAG.cpp
index b3ee0d1..e4e99db 100644
--- a/lib/Target/ARM/ARMISelDAGToDAG.cpp
+++ b/lib/Target/ARM/ARMISelDAGToDAG.cpp
@@ -160,6 +160,7 @@
   DEBUG(BB->dump());
 
   DAG.setRoot(SelectRoot(DAG.getRoot()));
+  assert(InFlightSet.empty() && "ISel InFlightSet has not been emptied!");
   CodeGenMap.clear();
   HandleMap.clear();
   ReplaceMap.clear();
diff --git a/lib/Target/Alpha/AlphaISelDAGToDAG.cpp b/lib/Target/Alpha/AlphaISelDAGToDAG.cpp
index 8126c33..837a911 100644
--- a/lib/Target/Alpha/AlphaISelDAGToDAG.cpp
+++ b/lib/Target/Alpha/AlphaISelDAGToDAG.cpp
@@ -154,6 +154,7 @@
   
   // Select target instructions for the DAG.
   DAG.setRoot(SelectRoot(DAG.getRoot()));
+  assert(InFlightSet.empty() && "ISel InFlightSet has not been emptied!");
   CodeGenMap.clear();
   HandleMap.clear();
   ReplaceMap.clear();
diff --git a/lib/Target/IA64/IA64ISelDAGToDAG.cpp b/lib/Target/IA64/IA64ISelDAGToDAG.cpp
index 6ac8ad6..0552677 100644
--- a/lib/Target/IA64/IA64ISelDAGToDAG.cpp
+++ b/lib/Target/IA64/IA64ISelDAGToDAG.cpp
@@ -147,6 +147,7 @@
     
   // Select target instructions for the DAG.
   DAG.setRoot(SelectRoot(DAG.getRoot()));
+  assert(InFlightSet.empty() && "ISel InFlightSet has not been emptied!");
   CodeGenMap.clear();
   HandleMap.clear();
   ReplaceMap.clear();
diff --git a/lib/Target/PowerPC/PPCISelDAGToDAG.cpp b/lib/Target/PowerPC/PPCISelDAGToDAG.cpp
index 9e22f11..071e844 100644
--- a/lib/Target/PowerPC/PPCISelDAGToDAG.cpp
+++ b/lib/Target/PowerPC/PPCISelDAGToDAG.cpp
@@ -205,6 +205,7 @@
     
   // Select target instructions for the DAG.
   DAG.setRoot(SelectRoot(DAG.getRoot()));
+  assert(InFlightSet.empty() && "ISel InFlightSet has not been emptied!");
   CodeGenMap.clear();
   HandleMap.clear();
   ReplaceMap.clear();
diff --git a/lib/Target/Sparc/SparcISelDAGToDAG.cpp b/lib/Target/Sparc/SparcISelDAGToDAG.cpp
index 19df27e..c5ad35a 100644
--- a/lib/Target/Sparc/SparcISelDAGToDAG.cpp
+++ b/lib/Target/Sparc/SparcISelDAGToDAG.cpp
@@ -995,6 +995,7 @@
   
   // Select target instructions for the DAG.
   DAG.setRoot(SelectRoot(DAG.getRoot()));
+  assert(InFlightSet.empty() && "ISel InFlightSet has not been emptied!");
   CodeGenMap.clear();
   HandleMap.clear();
   ReplaceMap.clear();
diff --git a/lib/Target/X86/X86ISelDAGToDAG.cpp b/lib/Target/X86/X86ISelDAGToDAG.cpp
index af28f83..f58ca60 100644
--- a/lib/Target/X86/X86ISelDAGToDAG.cpp
+++ b/lib/Target/X86/X86ISelDAGToDAG.cpp
@@ -182,6 +182,7 @@
   Indent = 0;
 #endif
   DAG.setRoot(SelectRoot(DAG.getRoot()));
+  assert(InFlightSet.empty() && "ISel InFlightSet has not been emptied!");
 #ifndef NDEBUG
   DEBUG(std::cerr << "===== Instruction selection ends:\n");
 #endif