Index: lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
===================================================================
--- lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
+++ lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
@@ -7865,6 +7865,7 @@
 
 /// visitInlineAsm - Handle a call to an InlineAsm object.
 void SelectionDAGBuilder::visitInlineAsm(ImmutableCallSite CS) {
+  LLVMContext &Ctx = *DAG.getContext();
   const InlineAsm *IA = cast<InlineAsm>(CS.getCalledValue());
 
   /// ConstraintOperands - Information about all of the constraints.
@@ -7907,7 +7908,7 @@
 
       OpInfo.ConstraintVT =
           OpInfo
-              .getCallOperandValEVT(*DAG.getContext(), TLI, DAG.getDataLayout())
+              .getCallOperandValEVT(Ctx, TLI, DAG.getDataLayout())
               .getSimpleVT();
     } else if (OpInfo.Type == InlineAsm::isOutput && !OpInfo.isIndirect) {
       // The return value of the call is this value.  As such, there is no
@@ -7935,6 +7936,12 @@
     // Compute the constraint code and ConstraintType to use.
     TLI.ComputeConstraintToUse(T, SDValue());
 
+    if (T.ConstraintCode == "n" && !isa<ConstantSDNode>(OpInfo.CallOperand))
+      // We've delayed emitting a diagnostic for the "n" constraint because
+      // inlining could cause an integer showing up.
+      return emitInlineAsmError(CS, "constraint 'n' expects an integer "
+                                "constant expression");
+
     ExtraInfo.update(T);
   }
 
Index: test/CodeGen/X86/inline-asm-bad-constraint-n.ll
===================================================================
--- test/CodeGen/X86/inline-asm-bad-constraint-n.ll
+++ test/CodeGen/X86/inline-asm-bad-constraint-n.ll
@@ -2,7 +2,7 @@
 
 @x = global i32 0, align 4
 
-;CHECK:	error: invalid operand for inline asm constraint 'n'
+; CHECK: error: constraint 'n' expects an integer constant expression
 define void @foo() {
   %a = getelementptr i32, i32* @x, i32 1
   call void asm sideeffect "foo $0", "n"(i32* %a) nounwind
Index: test/CodeGen/X86/inline-asm-n-constraint.ll
===================================================================
--- /dev/null
+++ test/CodeGen/X86/inline-asm-n-constraint.ll
@@ -0,0 +1,13 @@
+; RUN: llc -mtriple=x86_64-unknown-unknown -no-integrated-as < %s 2>&1 | FileCheck %s
+
+@x = global i32 0, align 4
+
+define void @foo() {
+; CHECK-LABEL: foo:
+  call void asm sideeffect "foo $0", "n"(i32 42) nounwind
+; CHECK:      #APP
+; CHECK-NEXT: foo    $42
+; CHECK-NEXT: #NO_APP
+  ret void
+; CHECK-NEXT: retq
+}