diff --git a/llvm/lib/CodeGen/GCRootLowering.cpp b/llvm/lib/CodeGen/GCRootLowering.cpp
index a46d19755357..637a877810a1 100644
--- a/llvm/lib/CodeGen/GCRootLowering.cpp
+++ b/llvm/lib/CodeGen/GCRootLowering.cpp
@@ -271,16 +271,15 @@ void GCMachineCodeAnalysis::VisitCallPoint(MachineBasicBlock::iterator CI) {
 
 void GCMachineCodeAnalysis::FindSafePoints(MachineFunction &MF) {
   for (MachineBasicBlock &MBB : MF)
-    for (MachineBasicBlock::iterator MI = MBB.begin(), ME = MBB.end();
-         MI != ME; ++MI)
-      if (MI->isCall()) {
+    for (MachineInstr &MI : MBB)
+      if (MI.isCall()) {
         // Do not treat tail or sibling call sites as safe points.  This is
         // legal since any arguments passed to the callee which live in the
         // remnants of the callers frame will be owned and updated by the
         // callee if required.
-        if (MI->isTerminator())
+        if (MI.isTerminator())
           continue;
-        VisitCallPoint(MI);
+        VisitCallPoint(&MI);
       }
 }
 
diff --git a/llvm/lib/CodeGen/MachineBasicBlock.cpp b/llvm/lib/CodeGen/MachineBasicBlock.cpp
index a56fb3f115d6..23c511aaa056 100644
--- a/llvm/lib/CodeGen/MachineBasicBlock.cpp
+++ b/llvm/lib/CodeGen/MachineBasicBlock.cpp
@@ -134,9 +134,8 @@ void ilist_callback_traits<MachineBasicBlock>::addNodeToList(
 
   // Make sure the instructions have their operands in the reginfo lists.
   MachineRegisterInfo &RegInfo = MF.getRegInfo();
-  for (MachineBasicBlock::instr_iterator
-         I = N->instr_begin(), E = N->instr_end(); I != E; ++I)
-    I->AddRegOperandsToUseLists(RegInfo);
+  for (MachineInstr &MI : N->instrs())
+    MI.AddRegOperandsToUseLists(RegInfo);
 }
 
 void ilist_callback_traits<MachineBasicBlock>::removeNodeFromList(
diff --git a/llvm/lib/Target/AArch64/AArch64SIMDInstrOpt.cpp b/llvm/lib/Target/AArch64/AArch64SIMDInstrOpt.cpp
index 03b32967a212..9125b37b50d4 100644
--- a/llvm/lib/Target/AArch64/AArch64SIMDInstrOpt.cpp
+++ b/llvm/lib/Target/AArch64/AArch64SIMDInstrOpt.cpp
@@ -711,9 +711,7 @@ bool AArch64SIMDInstrOpt::runOnMachineFunction(MachineFunction &MF) {
     if (!shouldExitEarly(&MF, OptimizationKind)) {
       SmallVector<MachineInstr *, 8> RemoveMIs;
       for (MachineBasicBlock &MBB : MF) {
-        for (MachineBasicBlock::iterator MII = MBB.begin(), MIE = MBB.end();
-             MII != MIE;) {
-          MachineInstr &MI = *MII;
+        for (MachineInstr &MI : MBB) {
           bool InstRewrite;
           if (OptimizationKind == VectorElem)
             InstRewrite = optimizeVectElement(MI) ;
@@ -725,7 +723,6 @@ bool AArch64SIMDInstrOpt::runOnMachineFunction(MachineFunction &MF) {
             RemoveMIs.push_back(&MI);
             Changed = true;
           }
-          ++MII;
         }
       }
       for (MachineInstr *MI : RemoveMIs)
diff --git a/llvm/lib/Target/AMDGPU/AMDILCFGStructurizer.cpp b/llvm/lib/Target/AMDGPU/AMDILCFGStructurizer.cpp
index e87dfd6bde7b..1a9255f3240f 100644
--- a/llvm/lib/Target/AMDGPU/AMDILCFGStructurizer.cpp
+++ b/llvm/lib/Target/AMDGPU/AMDILCFGStructurizer.cpp
@@ -575,12 +575,9 @@ bool AMDGPUCFGStructurizer::isUncondBranch(MachineInstr *MI) {
 DebugLoc AMDGPUCFGStructurizer::getLastDebugLocInBB(MachineBasicBlock *MBB) {
   //get DebugLoc from the first MachineBasicBlock instruction with debug info
   DebugLoc DL;
-  for (MachineBasicBlock::iterator It = MBB->begin(); It != MBB->end();
-      ++It) {
-    MachineInstr *instr = &(*It);
-    if (instr->getDebugLoc())
-      DL = instr->getDebugLoc();
-  }
+  for (MachineInstr &MI : *MBB)
+    if (MI.getDebugLoc())
+      DL = MI.getDebugLoc();
   return DL;
 }
 
diff --git a/llvm/lib/Target/AMDGPU/SIInsertWaitcnts.cpp b/llvm/lib/Target/AMDGPU/SIInsertWaitcnts.cpp
index 06a3fdfea437..f4e5771d2a2a 100644
--- a/llvm/lib/Target/AMDGPU/SIInsertWaitcnts.cpp
+++ b/llvm/lib/Target/AMDGPU/SIInsertWaitcnts.cpp
@@ -1687,17 +1687,13 @@ bool SIInsertWaitcnts::runOnMachineFunction(MachineFunction &MF) {
 
   bool HaveScalarStores = false;
 
-  for (MachineFunction::iterator BI = MF.begin(), BE = MF.end(); BI != BE;
-       ++BI) {
-    MachineBasicBlock &MBB = *BI;
-
-    for (MachineBasicBlock::iterator I = MBB.begin(), E = MBB.end(); I != E;
-         ++I) {
-      if (!HaveScalarStores && TII->isScalarStore(*I))
+  for (MachineBasicBlock &MBB : MF) {
+    for (MachineInstr &MI : MBB) {
+      if (!HaveScalarStores && TII->isScalarStore(MI))
         HaveScalarStores = true;
 
-      if (I->getOpcode() == AMDGPU::S_ENDPGM ||
-          I->getOpcode() == AMDGPU::SI_RETURN_TO_EPILOG)
+      if (MI.getOpcode() == AMDGPU::S_ENDPGM ||
+          MI.getOpcode() == AMDGPU::SI_RETURN_TO_EPILOG)
         EndPgmBlocks.push_back(&MBB);
     }
   }
diff --git a/llvm/lib/Target/Hexagon/HexagonConstPropagation.cpp b/llvm/lib/Target/Hexagon/HexagonConstPropagation.cpp
index 7579a5e5f0b2..daf311fc49d4 100644
--- a/llvm/lib/Target/Hexagon/HexagonConstPropagation.cpp
+++ b/llvm/lib/Target/Hexagon/HexagonConstPropagation.cpp
@@ -995,8 +995,7 @@ bool MachineConstPropagator::rewrite(MachineFunction &MF) {
     bool HaveTargets = computeBlockSuccessors(B, Targets);
     // Rewrite the executable instructions. Skip branches if we don't
     // have block successor information.
-    for (auto I = B->rbegin(), E = B->rend(); I != E; ++I) {
-      MachineInstr &MI = *I;
+    for (MachineInstr &MI : llvm::reverse(*B)) {
       if (InstrExec.count(&MI)) {
         if (MI.isBranch() && !HaveTargets)
           continue;
diff --git a/llvm/lib/Target/Hexagon/HexagonGenMux.cpp b/llvm/lib/Target/Hexagon/HexagonGenMux.cpp
index d0f36291201a..cf4f13fb8c0d 100644
--- a/llvm/lib/Target/Hexagon/HexagonGenMux.cpp
+++ b/llvm/lib/Target/Hexagon/HexagonGenMux.cpp
@@ -183,12 +183,11 @@ void HexagonGenMux::buildMaps(MachineBasicBlock &B, InstrIndexMap &I2X,
   unsigned NR = HRI->getNumRegs();
   BitVector Defs(NR), Uses(NR);
 
-  for (MachineBasicBlock::iterator I = B.begin(), E = B.end(); I != E; ++I) {
-    MachineInstr *MI = &*I;
-    I2X.insert(std::make_pair(MI, Index));
+  for (MachineInstr &MI : B) {
+    I2X.insert(std::make_pair(&MI, Index));
     Defs.reset();
     Uses.reset();
-    getDefsUses(MI, Defs, Uses);
+    getDefsUses(&MI, Defs, Uses);
     DUM.insert(std::make_pair(Index, DefUseInfo(Defs, Uses)));
     Index++;
   }