Index: llvm/include/llvm/CodeGen/ReachingDefAnalysis.h
===================================================================
--- llvm/include/llvm/CodeGen/ReachingDefAnalysis.h
+++ llvm/include/llvm/CodeGen/ReachingDefAnalysis.h
@@ -176,7 +176,7 @@
 
   /// Assuming MI is dead, recursively search the incoming operands which are
   /// killed by MI and collect those that would become dead.
-  void collectLocalKilledOperands(MachineInstr *MI, InstSet &Dead) const;
+  void collectKilledOperands(MachineInstr *MI, InstSet &Dead) const;
 
   /// Return whether removing this instruction will have no effect on the
   /// program, returning the redundant use-def chain.
Index: llvm/lib/CodeGen/ReachingDefAnalysis.cpp
===================================================================
--- llvm/lib/CodeGen/ReachingDefAnalysis.cpp
+++ llvm/lib/CodeGen/ReachingDefAnalysis.cpp
@@ -525,8 +525,8 @@
   return true;
 }
 
-void ReachingDefAnalysis::collectLocalKilledOperands(MachineInstr *MI,
-                                                     InstSet &Dead) const {
+void ReachingDefAnalysis::collectKilledOperands(MachineInstr *MI,
+                                                InstSet &Dead) const {
   Dead.insert(MI);
   auto IsDead = [this](MachineInstr *Def, int PhysReg) {
     unsigned LiveDefs = 0;
@@ -539,15 +539,17 @@
 
     SmallPtrSet<MachineInstr*, 4> Uses;
     getGlobalUses(Def, PhysReg, Uses);
+    // This is called when a user is going to be removed, so Def will be dead
+    // if it only has one user.
     return Uses.size() == 1;
   };
 
   for (auto &MO : MI->uses()) {
     if (!MO.isReg() || MO.getReg() == 0 || !MO.isKill())
       continue;
-    if (MachineInstr *Def = getReachingLocalMIDef(MI, MO.getReg()))
+    if (MachineInstr *Def = getMIOperand(MI, MO))
       if (IsDead(Def, MO.getReg()))
-        collectLocalKilledOperands(Def, Dead);
+        collectKilledOperands(Def, Dead);
   }
 }
 
Index: llvm/lib/Target/ARM/ARMLowOverheadLoops.cpp
===================================================================
--- llvm/lib/Target/ARM/ARMLowOverheadLoops.cpp
+++ llvm/lib/Target/ARM/ARMLowOverheadLoops.cpp
@@ -901,16 +901,27 @@
   if (!Def)
     return;
 
-  // Collect IT blocks.
+  // Collect the dead code and the MBBs in which they reside.
+  SmallPtrSet<MachineInstr*, 4> Killed;
+  RDA->collectKilledOperands(Def, Killed);
+  SmallPtrSet<MachineBasicBlock*, 2> BasicBlocks;
+  for (auto *MI : Killed)
+    BasicBlocks.insert(MI->getParent());
+
+  // Collect IT blocks in all affected basic blocks.
   std::map<MachineInstr *, SmallPtrSet<MachineInstr *, 2>> ITBlocks;
   std::map<MachineInstr *, MachineInstr *> Predicates;
-  MachineInstr *IT = nullptr;
-  for (auto &MI : *Def->getParent()) {
-    if (MI.getOpcode() == ARM::t2IT)
-      IT = &MI;
-    else if (TII->getPredicate(MI) != ARMCC::AL) {
-      ITBlocks[IT].insert(&MI);
-      Predicates[&MI] = IT;
+  for (auto *MBB : BasicBlocks) {
+    MachineInstr *IT = nullptr;
+    for (auto &MI : *MBB) {
+      if (MI.getOpcode() == ARM::t2IT)
+        IT = &MI;
+      else if (IT && TII->getPredicate(MI) != ARMCC::AL) {
+        ITBlocks[IT].insert(&MI);
+        Predicates[&MI] = IT;
+        if (MI.getOperand(MI.getNumOperands()-1).isKill())
+          IT = nullptr;
+      }
     }
   }
 
@@ -918,8 +929,6 @@
   // also remove the IT instruction.
   SmallPtrSet<MachineInstr*, 2> ModifiedITs;
   SmallPtrSet<MachineInstr*, 2> DeadITs;
-  SmallPtrSet<MachineInstr*, 4> Killed;
-  RDA->collectLocalKilledOperands(Def, Killed);
   for (auto *MI : Killed) {
     if (!Predicates.count(MI))
       continue;
Index: llvm/test/CodeGen/Thumb2/LowOverheadLoops/it-block-mov.mir
===================================================================
--- llvm/test/CodeGen/Thumb2/LowOverheadLoops/it-block-mov.mir
+++ llvm/test/CodeGen/Thumb2/LowOverheadLoops/it-block-mov.mir
@@ -45,10 +45,7 @@
   ; CHECK:   frame-setup CFI_INSTRUCTION def_cfa_offset 8
   ; CHECK:   frame-setup CFI_INSTRUCTION offset $lr, -4
   ; CHECK:   frame-setup CFI_INSTRUCTION offset $r4, -8
-  ; CHECK:   tCMPi8 renamable $r1, 4, 14 /* CC::al */, $noreg, implicit-def $cpsr
-  ; CHECK:   renamable $r3 = t2MOVi 4, 14 /* CC::al */, $noreg, $noreg
-  ; CHECK:   t2IT 11, 8, implicit-def $itstate
-  ; CHECK:   dead $r3 = tMOVr renamable $r1, 11 /* CC::lt */, killed $cpsr, implicit killed renamable $r3, implicit killed $itstate
+  ; CHECK:   tCMPi8 renamable $r1, 4, 14 /* CC::al */, $noreg, implicit-def dead $cpsr
   ; CHECK:   tCMPi8 renamable $r1, 2, 14 /* CC::al */, $noreg, implicit-def $cpsr
   ; CHECK:   renamable $r12 = t2MOVi 4, 14 /* CC::al */, $noreg, $noreg
   ; CHECK:   tBcc %bb.2, 2 /* CC::hs */, killed $cpsr