Index: lib/CodeGen/CodeGenPrepare.cpp
===================================================================
--- lib/CodeGen/CodeGenPrepare.cpp
+++ lib/CodeGen/CodeGenPrepare.cpp
@@ -261,9 +261,9 @@
   if (!DisableBranchOpts) {
     MadeChange = false;
     SmallPtrSet<BasicBlock*, 8> WorkList;
-    for (Function::iterator BB = F.begin(), E = F.end(); BB != E; ++BB) {
-      SmallVector<BasicBlock*, 2> Successors(succ_begin(BB), succ_end(BB));
-      MadeChange |= ConstantFoldTerminator(BB, true);
+    for (BasicBlock &BB : F) {
+      SmallVector<BasicBlock*, 2> Successors(succ_begin(&BB), succ_end(&BB));
+      MadeChange |= ConstantFoldTerminator(&BB, true);
       if (!MadeChange) continue;
 
       for (SmallVectorImpl<BasicBlock*>::iterator
@@ -4327,18 +4327,17 @@
 // find a node corresponding to the value.
 bool CodeGenPrepare::PlaceDbgValues(Function &F) {
   bool MadeChange = false;
-  for (Function::iterator I = F.begin(), E = F.end(); I != E; ++I) {
+  for (BasicBlock &BB : F) {
     Instruction *PrevNonDbgInst = nullptr;
-    for (BasicBlock::iterator BI = I->begin(), BE = I->end(); BI != BE;) {
-      Instruction *Insn = BI; ++BI;
-      DbgValueInst *DVI = dyn_cast<DbgValueInst>(Insn);
+    for (Instruction &Insn : BB) {
+      DbgValueInst *DVI = dyn_cast<DbgValueInst>(&Insn);
       // Leave dbg.values that refer to an alloca alone. These
       // instrinsics describe the address of a variable (= the alloca)
       // being taken.  They should not be moved next to the alloca
       // (and to the beginning of the scope), but rather stay close to
       // where said address is used.
       if (!DVI || (DVI->getValue() && isa<AllocaInst>(DVI->getValue()))) {
-        PrevNonDbgInst = Insn;
+        PrevNonDbgInst = &Insn;
         continue;
       }