Index: lib/CodeGen/MachineVerifier.cpp
===================================================================
--- lib/CodeGen/MachineVerifier.cpp
+++ lib/CodeGen/MachineVerifier.cpp
@@ -504,6 +504,10 @@
 MachineVerifier::visitMachineBasicBlockBefore(const MachineBasicBlock *MBB) {
   FirstTerminator = nullptr;
 
+  if (!MBB->verifyLiveIns()) {
+    report("MBB has duplicate or out-of-order live-ins.", MBB);
+  }
+
   if (MRI->isSSA()) {
     // If this block has allocatable physical registers live-in, check that
     // it is an entry block or landing pad.