Index: lib/CodeGen/BranchFolding.cpp
===================================================================
--- lib/CodeGen/BranchFolding.cpp
+++ lib/CodeGen/BranchFolding.cpp
@@ -397,6 +397,7 @@
     for (unsigned int i = 1, e = TRI->getNumRegs(); i != e; i++)
       if (RS->isRegUsed(i, false))
         NewMBB->addLiveIn(i);
+    NewMBB->sortUniqueLiveIns();
   }
 }
 
@@ -1836,6 +1837,8 @@
       FBB->addLiveIn(Def);
     }
   }
+  TBB->sortUniqueLiveIns();
+  FBB->sortUniqueLiveIns();
 
   ++NumHoist;
   return true;
Index: lib/CodeGen/ExecutionDepsFix.cpp
===================================================================
--- lib/CodeGen/ExecutionDepsFix.cpp
+++ lib/CodeGen/ExecutionDepsFix.cpp
@@ -375,6 +375,7 @@
 
   // This is the entry block.
   if (MBB->pred_empty()) {
+    MBB->sortUniqueLiveIns();
     for (MachineBasicBlock::livein_iterator i = MBB->livein_begin(),
          e = MBB->livein_end(); i != e; ++i) {
       for (int rx : regIndices(*i)) {
Index: lib/CodeGen/LiveVariables.cpp
===================================================================
--- lib/CodeGen/LiveVariables.cpp
+++ lib/CodeGen/LiveVariables.cpp
@@ -557,6 +557,9 @@
 }
 
 void LiveVariables::runOnBlock(MachineBasicBlock *MBB, const unsigned NumRegs) {
+  // Sort and Unique the LiveIns just in case.
+  MBB->sortUniqueLiveIns();
+
   // Mark live-in registers as live-in.
   SmallVector<unsigned, 4> Defs;
   for (MachineBasicBlock::livein_iterator II = MBB->livein_begin(),
Index: lib/CodeGen/MachineCSE.cpp
===================================================================
--- lib/CodeGen/MachineCSE.cpp
+++ lib/CodeGen/MachineCSE.cpp
@@ -628,6 +628,8 @@
           if (!MBB->isLiveIn(LiveIn))
             MBB->addLiveIn(LiveIn);
         }
+
+        MBB->sortUniqueLiveIns();
         ++NumCrossBBCSEs;
       }
 
Index: lib/CodeGen/MachineLICM.cpp
===================================================================
--- lib/CodeGen/MachineLICM.cpp
+++ lib/CodeGen/MachineLICM.cpp
@@ -619,6 +619,7 @@
           MO.setIsKill(false);
       }
     }
+    BB->sortUniqueLiveIns();
   }
 }
 
Index: lib/CodeGen/MachineRegisterInfo.cpp
===================================================================
--- lib/CodeGen/MachineRegisterInfo.cpp
+++ lib/CodeGen/MachineRegisterInfo.cpp
@@ -391,6 +391,8 @@
       // Add the register to the entry block live-in set.
       EntryMBB->addLiveIn(LiveIns[i].first);
     }
+
+  EntryMBB->sortUniqueLiveIns();
 }
 
 unsigned MachineRegisterInfo::getMaxLaneMaskForVReg(unsigned Reg) const
Index: lib/CodeGen/PrologEpilogInserter.cpp
===================================================================
--- lib/CodeGen/PrologEpilogInserter.cpp
+++ lib/CodeGen/PrologEpilogInserter.cpp
@@ -436,6 +436,9 @@
       // It's killed at the spill.
       MBB->addLiveIn(CSI[i].getReg());
   }
+
+  for (MachineBasicBlock *MBB : Visited)
+    MBB->sortUniqueLiveIns();
 }
 
 /// insertCSRSpillsAndRestores - Insert spill and restore code for