[Transforms/Scalar] Use range-based for loops (NFC)

Author: kazutakahirata

llvm/lib/Transforms/Scalar/DeadStoreElimination.cpp

@@ -776,16 +776,16 @@ memoryIsNotModifiedBetween(Instruction *FirstI, Instruction *SecondI, AATy &AA,
     if (B != FirstBB) {
       assert(B != &FirstBB->getParent()->getEntryBlock() &&
           "Should not hit the entry block because SI must be dominated by LI");
-      for (auto PredI = pred_begin(B), PE = pred_end(B); PredI != PE; ++PredI) {
+      for (BasicBlock *Pred : predecessors(B)) {
         PHITransAddr PredAddr = Addr;
         if (PredAddr.NeedsPHITranslationFromBlock(B)) {
           if (!PredAddr.IsPotentiallyPHITranslatable())
             return false;
-          if (PredAddr.PHITranslateValue(B, *PredI, DT, false))
+          if (PredAddr.PHITranslateValue(B, Pred, DT, false))
             return false;
         }
         Value *TranslatedPtr = PredAddr.getAddr();
-        auto Inserted = Visited.insert(std::make_pair(*PredI, TranslatedPtr));
+        auto Inserted = Visited.insert(std::make_pair(Pred, TranslatedPtr));
         if (!Inserted.second) {
           // We already visited this block before. If it was with a different
           // address - bail out!
@@ -794,7 +794,7 @@ memoryIsNotModifiedBetween(Instruction *FirstI, Instruction *SecondI, AATy &AA,
           // ... otherwise just skip it.
           continue;
         }
-        WorkList.push_back(std::make_pair(*PredI, PredAddr));
+        WorkList.push_back(std::make_pair(Pred, PredAddr));
       }
     }
   }
@@ -805,8 +805,7 @@ memoryIsNotModifiedBetween(Instruction *FirstI, Instruction *SecondI, AATy &AA,
 /// them to F.
 static void findUnconditionalPreds(SmallVectorImpl<BasicBlock *> &Blocks,
                                    BasicBlock *BB, DominatorTree *DT) {
-  for (pred_iterator I = pred_begin(BB), E = pred_end(BB); I != E; ++I) {
-    BasicBlock *Pred = *I;
+  for (BasicBlock *Pred : predecessors(BB)) {
     if (Pred == BB) continue;
     Instruction *PredTI = Pred->getTerminator();
     if (PredTI->getNumSuccessors() != 1)

llvm/lib/Transforms/Scalar/GVN.cpp

@@ -2795,9 +2795,7 @@ void GVN::addDeadBlock(BasicBlock *BB) {
 
   // For the dead blocks' live successors, update their phi nodes by replacing
   // the operands corresponding to dead blocks with UndefVal.
-  for(SmallSetVector<BasicBlock *, 4>::iterator I = DF.begin(), E = DF.end();
-        I != E; I++) {
-    BasicBlock *B = *I;
+  for (BasicBlock *B : DF) {
     if (DeadBlocks.count(B))
       continue;
 

llvm/lib/Transforms/Scalar/LoopUnswitch.cpp

@@ -310,9 +310,8 @@ bool LUAnalysisCache::countLoop(const Loop *L, const TargetTransformInfo &TTI,
     // consideration code simplification opportunities and code that can
     // be shared by the resultant unswitched loops.
     CodeMetrics Metrics;
-    for (Loop::block_iterator I = L->block_begin(), E = L->block_end(); I != E;
-         ++I)
-      Metrics.analyzeBasicBlock(*I, TTI, EphValues);
+    for (BasicBlock *BB : L->blocks())
+      Metrics.analyzeBasicBlock(BB, TTI, EphValues);
 
     Props.SizeEstimation = Metrics.NumInsts;
     Props.CanBeUnswitchedCount = MaxSize / (Props.SizeEstimation);
@@ -1132,9 +1131,9 @@ static bool isTrivialLoopExitBlockHelper(Loop *L, BasicBlock *BB,
   }
 
   // Otherwise, this is an unvisited intra-loop node.  Check all successors.
-  for (succ_iterator SI = succ_begin(BB), E = succ_end(BB); SI != E; ++SI) {
+  for (BasicBlock *Succ : successors(BB)) {
     // Check to see if the successor is a trivial loop exit.
-    if (!isTrivialLoopExitBlockHelper(L, *SI, ExitBB, Visited))
+    if (!isTrivialLoopExitBlockHelper(L, Succ, ExitBB, Visited))
       return false;
   }
 
@@ -1628,9 +1627,7 @@ void LoopUnswitch::unswitchNontrivialCondition(
       PHINode *PN = PHINode::Create(LPad->getType(), 0, "",
                                     &*ExitSucc->getFirstInsertionPt());
 
-      for (pred_iterator I = pred_begin(ExitSucc), E = pred_end(ExitSucc);
-           I != E; ++I) {
-        BasicBlock *BB = *I;
+      for (BasicBlock *BB : predecessors(ExitSucc)) {
         LandingPadInst *LPI = BB->getLandingPadInst();
         LPI->replaceAllUsesWith(PN);
         PN->addIncoming(LPI, BB);

llvm/lib/Transforms/Scalar/MergeICmps.cpp

@@ -440,8 +440,7 @@ BCECmpChain::BCECmpChain(const std::vector<BasicBlock *> &Blocks, PHINode &Phi,
   // Now look inside blocks to check for BCE comparisons.
   std::vector<BCECmpBlock> Comparisons;
   BaseIdentifier BaseId;
-  for (size_t BlockIdx = 0; BlockIdx < Blocks.size(); ++BlockIdx) {
-    BasicBlock *const Block = Blocks[BlockIdx];
+  for (BasicBlock *const Block : Blocks) {
     assert(Block && "invalid block");
     BCECmpBlock Comparison = visitCmpBlock(Phi.getIncomingValueForBlock(Block),
                                            Block, Phi.getParent(), BaseId);

llvm/lib/Transforms/Scalar/NaryReassociate.cpp

@@ -364,8 +364,8 @@ NaryReassociatePass::tryReassociateGEPAtIndex(GetElementPtrInst *GEP,
   // Look for GEP's closest dominator that has the same SCEV as GEP except that
   // the I-th index is replaced with LHS.
   SmallVector<const SCEV *, 4> IndexExprs;
-  for (auto Index = GEP->idx_begin(); Index != GEP->idx_end(); ++Index)
-    IndexExprs.push_back(SE->getSCEV(*Index));
+  for (Use &Index : GEP->indices())
+    IndexExprs.push_back(SE->getSCEV(Index));
   // Replace the I-th index with LHS.
   IndexExprs[I] = SE->getSCEV(LHS);
   if (isKnownNonNegative(LHS, *DL, 0, AC, GEP, DT) &&

llvm/lib/Transforms/Scalar/StraightLineStrengthReduce.cpp

@@ -312,8 +312,8 @@ bool StraightLineStrengthReduce::isFoldable(const Candidate &C,
 // Returns true if GEP has zero or one non-zero index.
 static bool hasOnlyOneNonZeroIndex(GetElementPtrInst *GEP) {
   unsigned NumNonZeroIndices = 0;
-  for (auto I = GEP->idx_begin(); I != GEP->idx_end(); ++I) {
-    ConstantInt *ConstIdx = dyn_cast<ConstantInt>(*I);
+  for (Use &Idx : GEP->indices()) {
+    ConstantInt *ConstIdx = dyn_cast<ConstantInt>(Idx);
     if (ConstIdx == nullptr || !ConstIdx->isZero())
       ++NumNonZeroIndices;
   }
@@ -533,8 +533,8 @@ void StraightLineStrengthReduce::allocateCandidatesAndFindBasisForGEP(
     return;
 
   SmallVector<const SCEV *, 4> IndexExprs;
-  for (auto I = GEP->idx_begin(); I != GEP->idx_end(); ++I)
-    IndexExprs.push_back(SE->getSCEV(*I));
+  for (Use &Idx : GEP->indices())
+    IndexExprs.push_back(SE->getSCEV(Idx));
 
   gep_type_iterator GTI = gep_type_begin(GEP);
   for (unsigned I = 1, E = GEP->getNumOperands(); I != E; ++I, ++GTI) {

llvm/lib/Transforms/Scalar/StructurizeCFG.cpp

@@ -677,9 +677,8 @@ void StructurizeCFG::killTerminator(BasicBlock *BB) {
   if (!Term)
     return;
 
-  for (succ_iterator SI = succ_begin(BB), SE = succ_end(BB);
-       SI != SE; ++SI)
-    delPhiValues(BB, *SI);
+  for (BasicBlock *Succ : successors(BB))
+    delPhiValues(BB, Succ);
 
   if (DA)
     DA->removeValue(Term);