diff --git a/llvm/lib/CodeGen/MIRVRegNamerUtils.cpp b/llvm/lib/CodeGen/MIRVRegNamerUtils.cpp
--- a/llvm/lib/CodeGen/MIRVRegNamerUtils.cpp
+++ b/llvm/lib/CodeGen/MIRVRegNamerUtils.cpp
@@ -13,23 +13,25 @@
 
 #define DEBUG_TYPE "mir-vregnamer-utils"
 
-bool VRegRenamer::doVRegRenaming(
-    const std::map<unsigned, unsigned> &VRegRenameMap) {
+using VRegRenameMap = std::map<unsigned, unsigned>;
+
+bool VRegRenamer::doVRegRenaming(const VRegRenameMap &VRM) {
   bool Changed = false;
-  for (auto I = VRegRenameMap.begin(), E = VRegRenameMap.end(); I != E; ++I) {
 
-    auto VReg = I->first;
-    auto Rename = I->second;
+  for (auto &E : VRM) {
+    unsigned VReg = E.first;
+    unsigned Rename = E.second;
 
     std::vector<MachineOperand *> RenameMOs;
-    for (auto &MO : MRI.reg_operands(VReg)) {
-      RenameMOs.push_back(&MO);
-    }
+    llvm::transform(MRI.reg_operands(VReg), std::back_inserter(RenameMOs),
+                    [](MachineOperand &MO) { return &MO; });
+    Changed = Changed || RenameMOs.size();
 
     for (auto *MO : RenameMOs) {
-      Changed = true;
       MO->setReg(Rename);
 
+      // TODO: Not sure if this makes sense anymore. Do we really want to drop
+      // semantic information like def/kill?
       if (!MO->isDef())
         MO->setIsKill(false);
     }
@@ -40,32 +42,25 @@
 
 std::map<unsigned, unsigned>
 VRegRenamer::getVRegRenameMap(const std::vector<NamedVReg> &VRegs) {
-  std::map<unsigned, unsigned> VRegRenameMap;
 
   std::map<std::string, unsigned> VRegNameCollisionMap;
 
   auto GetUniqueVRegName =
       [&VRegNameCollisionMap](const NamedVReg &Reg) -> std::string {
     auto It = VRegNameCollisionMap.find(Reg.getName());
-    unsigned Counter = 0;
-    if (It != VRegNameCollisionMap.end()) {
-      Counter = It->second;
-    }
+    unsigned Counter = (It != VRegNameCollisionMap.end()) ? It->second : 0;
     ++Counter;
     VRegNameCollisionMap[Reg.getName()] = Counter;
     return Reg.getName() + "__" + std::to_string(Counter);
   };
 
+  VRegRenameMap VRM;
   for (auto &Vreg : VRegs) {
-    auto Reg = Vreg.getReg();
-    assert(Register::isVirtualRegister(Reg) &&
-           "Expecting Virtual Registers Only");
-    auto NewNameForReg = GetUniqueVRegName(Vreg);
-    auto Rename = createVirtualRegisterWithName(Reg, NewNameForReg);
-
-    VRegRenameMap.insert(std::pair<unsigned, unsigned>(Reg, Rename));
+    unsigned Reg = Vreg.getReg();
+    assert(Register::isVirtualRegister(Reg) && "Expected Virtual Registers");
+    VRM[Reg] = createVirtualRegisterWithName(Reg, GetUniqueVRegName(Vreg));
   }
-  return VRegRenameMap;
+  return VRM;
 }
 
 std::string VRegRenamer::getInstructionOpcodeHash(MachineInstr &MI) {
@@ -90,9 +85,9 @@
   };
   SmallVector<unsigned, 16> MIOperands;
   MIOperands.push_back(MI.getOpcode());
-  for (auto &Op : MI.uses()) {
-    MIOperands.push_back(HashOperand(Op));
-  }
+  llvm::transform(
+      MI.uses(), std::back_inserter(MIOperands),
+      [&HashOperand](const MachineOperand &MO) { return HashOperand(MO); });
   auto HashMI = hash_combine_range(MIOperands.begin(), MIOperands.end());
   return std::to_string(HashMI).substr(0, 5);
 }
@@ -126,8 +121,8 @@
   if (VRegs.size() == 0)
     return false;
 
-  auto VRegRenameMap = getVRegRenameMap(VRegs);
-  return doVRegRenaming(VRegRenameMap);
+  auto VRM = getVRegRenameMap(VRegs);
+  return doVRegRenaming(VRM);
 }
 
 bool VRegRenamer::renameVRegs(MachineBasicBlock *MBB, unsigned BBNum) {