diff --git a/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp b/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
index e370e4a..8e4d09a 100644
--- a/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
+++ b/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
@@ -457,6 +457,8 @@
       // If this is an illegal scalar, expand it into its two component
       // pieces.
       SDOperand X, Y;
+      if (Op.getOpcode() == ISD::TargetConstant)
+        break;  // Allow illegal target nodes.
       ExpandOp(Op, X, Y);
     } else if (MVT::getVectorNumElements(VT) == 1) {
       // If this is an illegal single element vector, convert it to a
@@ -644,6 +646,9 @@
 /// is legal, recursively ensuring that the operands' operations remain
 /// legal.
 SDOperand SelectionDAGLegalize::LegalizeOp(SDOperand Op) {
+  if (Op.getOpcode() == ISD::TargetConstant) // Allow illegal target nodes.
+    return Op;
+  
   assert(isTypeLegal(Op.getValueType()) &&
          "Caller should expand or promote operands that are not legal!");
   SDNode *Node = Op.Val;
diff --git a/test/CodeGen/Generic/asm-large-immediate.ll b/test/CodeGen/Generic/asm-large-immediate.ll
new file mode 100644
index 0000000..7064913
--- /dev/null
+++ b/test/CodeGen/Generic/asm-large-immediate.ll
@@ -0,0 +1,8 @@
+; RUN: llvm-as < %s | llc | grep 68719476738
+
+define void @test() {
+entry:
+        tail call void asm sideeffect "/* result: ${0:c} */", "i,~{dirflag},~{fpsr},~{flags}"( i64 68719476738 )
+        ret void
+}
+