[Analysis] MemDepPrinter: cleanup a few loops (NFC)

[artagnon]

Summary

Make use of the newly introduced inst_range to clean up two loops. Clean
up a third one while at it.

[reames]

LGTM.

lib/Analysis/MemDepPrinter.cpp

const char *const MemDepPrinter::DepTypeStr[]
   = {"Clobber", "Def", "NonFuncLocal", "Unknown"};
 
 bool MemDepPrinter::runOnFunction(Function &F) {
   this->F = &F;
   MemoryDependenceAnalysis &MDA = getAnalysis<MemoryDependenceAnalysis>();
 
   // All this code uses non-const interfaces because MemDep is not
   // const-friendly, though nothing is actually modified.
-  for (inst_iterator I = inst_begin(F), E = inst_end(F); I != E; ++I) {
-    Instruction *Inst = &*I;
+  for (auto &I: inst_range(F)) {
+    Instruction *Inst = &I;
 
     if (!Inst->mayReadFromMemory() && !Inst->mayWriteToMemory())
       continue;
 
     MemDepResult Res = MDA.getDependency(Inst);
     if (!Res.isNonLocal()) {
       Deps[Inst].insert(std::make_pair(getInstTypePair(Res),
                                        static_cast<BasicBlock *>(nullptr)));
if (!Res.isNonLocal()) {
       }
     }
   }
 
   return false;
 }
 
 void MemDepPrinter::print(raw_ostream &OS, const Module *M) const {
-  for (const_inst_iterator I = inst_begin(*F), E = inst_end(*F); I != E; ++I) {
-    const Instruction *Inst = &*I;
+  for (auto &I: inst_range(*F)) {
+    const Instruction *Inst = &I;
 
     DepSetMap::const_iterator DI = Deps.find(Inst);
     if (DI == Deps.end())
       continue;
 
     const DepSet &InstDeps = DI->second;
 
-    for (DepSet::const_iterator I = InstDeps.begin(), E = InstDeps.end();
-         I != E; ++I) {
-      const Instruction *DepInst = I->first.getPointer();
-      DepType type = I->first.getInt();
-      const BasicBlock *DepBB = I->second;
+    for (auto &I: InstDeps) {
+      const Instruction *DepInst = I.first.getPointer();
+      DepType type = I.first.getInt();
+      const BasicBlock *DepBB = I.second;
 
       OS << "    ";
       OS << DepTypeStr[type];
       if (DepBB) {
         OS << " in block ";
         DepBB->printAsOperand(OS, /*PrintType=*/false, M);
       }
       if (DepInst) {