[C++11] Add predecessors(BasicBlock *) / successors(BasicBlock *) ite…

…rator ranges. Summary: This patch introduces two new iterator ranges and updates existing code to use it. No functional change intended. Test Plan: All tests (make check-all) still pass. Reviewers: dblaikie Reviewed By: dblaikie Subscribers: llvm-commits Differential Revision: http://reviews.llvm.org/D4481 llvm-svn: 213474
llvm · Jul 20, 2014 · d11beff · d11beff
1 parent 4100ebd
commit d11beff
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Showing 41 changed files with 166 additions and 226 deletions.
diff --git a/llvm/docs/ProgrammersManual.rst b/llvm/docs/ProgrammersManual.rst
@@ -1854,12 +1854,11 @@ iterate over all predecessors of BB:
   #include "llvm/Support/CFG.h"
   BasicBlock *BB = ...;
 
-  for (pred_iterator PI = pred_begin(BB), E = pred_end(BB); PI != E; ++PI) {
-    BasicBlock *Pred = *PI;
+  for (BasicBlock *Pred : predecessors(BB)) {
     // ...
   }
 
-Similarly, to iterate over successors use ``succ_iterator/succ_begin/succ_end``.
+Similarly, to iterate over successors use ``successors``.
 
 .. _simplechanges:
 

diff --git a/llvm/include/llvm/IR/CFG.h b/llvm/include/llvm/IR/CFG.h
@@ -93,6 +93,12 @@ inline pred_iterator pred_end(BasicBlock *BB) { return pred_iterator(BB, true);}
 inline const_pred_iterator pred_end(const BasicBlock *BB) {
   return const_pred_iterator(BB, true);
 }
+inline iterator_range<pred_iterator> predecessors(BasicBlock *BB) {
+  return make_range(pred_begin(BB), pred_end(BB));
+}
+inline iterator_range<const_pred_iterator> predecessors(const BasicBlock *BB) {
+  return make_range(pred_begin(BB), pred_end(BB));
+}
 
 
 
@@ -257,6 +263,12 @@ inline succ_iterator succ_end(BasicBlock *BB) {
 inline succ_const_iterator succ_end(const BasicBlock *BB) {
   return succ_const_iterator(BB->getTerminator(), true);
 }
+inline iterator_range<succ_iterator> successors(BasicBlock *BB) {
+  return make_range(succ_begin(BB), succ_end(BB));
+}
+inline iterator_range<succ_const_iterator> successors(const BasicBlock *BB) {
+  return make_range(succ_begin(BB), succ_end(BB));
+}
 
 template <typename T, typename U> struct isPodLike<SuccIterator<T, U> > {
   static const bool value = isPodLike<T>::value;

diff --git a/llvm/lib/Analysis/BranchProbabilityInfo.cpp b/llvm/lib/Analysis/BranchProbabilityInfo.cpp
@@ -530,9 +530,8 @@ void BranchProbabilityInfo::print(raw_ostream &OS, const Module *) const {
   assert(LastF && "Cannot print prior to running over a function");
   for (Function::const_iterator BI = LastF->begin(), BE = LastF->end();
        BI != BE; ++BI) {
-    for (succ_const_iterator SI = succ_begin(BI), SE = succ_end(BI);
-         SI != SE; ++SI) {
-      printEdgeProbability(OS << "  ", BI, *SI);
+    for (const BasicBlock *Succ : successors(BI)) {
+      printEdgeProbability(OS << "  ", BI, Succ);
     }
   }
 }
@@ -563,8 +562,7 @@ BasicBlock *BranchProbabilityInfo::getHotSucc(BasicBlock *BB) const {
   uint32_t MaxWeight = 0;
   BasicBlock *MaxSucc = nullptr;
 
-  for (succ_iterator I = succ_begin(BB), E = succ_end(BB); I != E; ++I) {
-    BasicBlock *Succ = *I;
+  for (BasicBlock *Succ : successors(BB)) {
     uint32_t Weight = getEdgeWeight(BB, Succ);
     uint32_t PrevSum = Sum;
 

diff --git a/llvm/lib/Analysis/Interval.cpp b/llvm/lib/Analysis/Interval.cpp
@@ -29,9 +29,8 @@ using namespace llvm;
 bool Interval::isLoop() const {
   // There is a loop in this interval iff one of the predecessors of the header
   // node lives in the interval.
-  for (::pred_iterator I = ::pred_begin(HeaderNode), E = ::pred_end(HeaderNode);
-       I != E; ++I)
-    if (contains(*I))
+  for (BasicBlock *Pred : predecessors(HeaderNode))
+    if (contains(Pred))
       return true;
   return false;
 }

diff --git a/llvm/lib/Analysis/LazyValueInfo.cpp b/llvm/lib/Analysis/LazyValueInfo.cpp
@@ -625,9 +625,9 @@ bool LazyValueInfoCache::solveBlockValueNonLocal(LVILatticeVal &BBLV,
   // Loop over all of our predecessors, merging what we know from them into
   // result.
   bool EdgesMissing = false;
-  for (pred_iterator PI = pred_begin(BB), E = pred_end(BB); PI != E; ++PI) {
+  for (BasicBlock *Pred : predecessors(BB)) {
     LVILatticeVal EdgeResult;
-    EdgesMissing |= !getEdgeValue(Val, *PI, BB, EdgeResult);
+    EdgesMissing |= !getEdgeValue(Val, Pred, BB, EdgeResult);
     if (EdgesMissing)
       continue;
 

diff --git a/llvm/lib/Analysis/LoopInfo.cpp b/llvm/lib/Analysis/LoopInfo.cpp
@@ -336,9 +336,8 @@ bool Loop::hasDedicatedExits() const {
   SmallVector<BasicBlock *, 4> ExitBlocks;
   getExitBlocks(ExitBlocks);
   for (unsigned i = 0, e = ExitBlocks.size(); i != e; ++i)
-    for (pred_iterator PI = pred_begin(ExitBlocks[i]),
-         PE = pred_end(ExitBlocks[i]); PI != PE; ++PI)
-      if (!contains(*PI))
+    for (BasicBlock *Pred : predecessors(ExitBlocks[i]))
+      if (!contains(Pred))
         return false;
   // All the requirements are met.
   return true;
@@ -360,12 +359,12 @@ Loop::getUniqueExitBlocks(SmallVectorImpl<BasicBlock *> &ExitBlocks) const {
     BasicBlock *current = *BI;
     switchExitBlocks.clear();
 
-    for (succ_iterator I = succ_begin(*BI), E = succ_end(*BI); I != E; ++I) {
+    for (BasicBlock *Succ : successors(*BI)) {
       // If block is inside the loop then it is not a exit block.
-      if (contains(*I))
+      if (contains(Succ))
         continue;
 
-      pred_iterator PI = pred_begin(*I);
+      pred_iterator PI = pred_begin(Succ);
       BasicBlock *firstPred = *PI;
 
       // If current basic block is this exit block's first predecessor
@@ -379,17 +378,17 @@ Loop::getUniqueExitBlocks(SmallVectorImpl<BasicBlock *> &ExitBlocks) const {
       // then it is possible that there are multiple edges from current block
       // to one exit block.
       if (std::distance(succ_begin(current), succ_end(current)) <= 2) {
-        ExitBlocks.push_back(*I);
+        ExitBlocks.push_back(Succ);
         continue;
       }
 
       // In case of multiple edges from current block to exit block, collect
       // only one edge in ExitBlocks. Use switchExitBlocks to keep track of
       // duplicate edges.
-      if (std::find(switchExitBlocks.begin(), switchExitBlocks.end(), *I)
+      if (std::find(switchExitBlocks.begin(), switchExitBlocks.end(), Succ)
           == switchExitBlocks.end()) {
-        switchExitBlocks.push_back(*I);
-        ExitBlocks.push_back(*I);
+        switchExitBlocks.push_back(Succ);
+        ExitBlocks.push_back(Succ);
       }
     }
   }

diff --git a/llvm/lib/Analysis/ScalarEvolution.cpp b/llvm/lib/Analysis/ScalarEvolution.cpp
@@ -4512,13 +4512,12 @@ ScalarEvolution::ComputeExitLimit(const Loop *L, BasicBlock *ExitingBlock) {
   // lead to the loop header.
   bool MustExecuteLoopHeader = true;
   BasicBlock *Exit = nullptr;
-  for (succ_iterator SI = succ_begin(ExitingBlock), SE = succ_end(ExitingBlock);
-       SI != SE; ++SI)
-    if (!L->contains(*SI)) {
+  for (BasicBlock *Succ : successors(ExitingBlock))
+    if (!L->contains(Succ)) {
       if (Exit) // Multiple exit successors.
         return getCouldNotCompute();
-      Exit = *SI;
-    } else if (*SI != L->getHeader()) {
+      Exit = Succ;
+    } else if (Succ != L->getHeader()) {
       MustExecuteLoopHeader = false;
     }
 

diff --git a/llvm/lib/CodeGen/CodeGenPrepare.cpp b/llvm/lib/CodeGen/CodeGenPrepare.cpp
@@ -453,8 +453,8 @@ void CodeGenPrepare::EliminateMostlyEmptyBlock(BasicBlock *BB) {
         for (unsigned i = 0, e = BBPN->getNumIncomingValues(); i != e; ++i)
           PN->addIncoming(InVal, BBPN->getIncomingBlock(i));
       } else {
-        for (pred_iterator PI = pred_begin(BB), E = pred_end(BB); PI != E; ++PI)
-          PN->addIncoming(InVal, *PI);
+        for (BasicBlock *Pred : predecessors(BB))
+          PN->addIncoming(InVal, Pred);
       }
     }
   }
@@ -977,11 +977,11 @@ bool CodeGenPrepare::DupRetToEnableTailCallOpts(BasicBlock *BB) {
     }
   } else {
     SmallPtrSet<BasicBlock*, 4> VisitedBBs;
-    for (pred_iterator PI = pred_begin(BB), PE = pred_end(BB); PI != PE; ++PI) {
-      if (!VisitedBBs.insert(*PI))
+    for (BasicBlock *Pred : predecessors(BB)) {
+      if (!VisitedBBs.insert(Pred))
         continue;
 
-      BasicBlock::InstListType &InstList = (*PI)->getInstList();
+      BasicBlock::InstListType &InstList = Pred->getInstList();
       BasicBlock::InstListType::reverse_iterator RI = InstList.rbegin();
       BasicBlock::InstListType::reverse_iterator RE = InstList.rend();
       do { ++RI; } while (RI != RE && isa<DbgInfoIntrinsic>(&*RI));

diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
@@ -1052,9 +1052,8 @@ void SelectionDAGISel::SelectAllBasicBlocks(const Function &Fn) {
 
     if (OptLevel != CodeGenOpt::None) {
       bool AllPredsVisited = true;
-      for (const_pred_iterator PI = pred_begin(LLVMBB), PE = pred_end(LLVMBB);
-           PI != PE; ++PI) {
-        if (!FuncInfo->VisitedBBs.count(*PI)) {
+      for (const BasicBlock *Pred : predecessors(LLVMBB)) {
+        if (!FuncInfo->VisitedBBs.count(Pred)) {
           AllPredsVisited = false;
           break;
         }

diff --git a/llvm/lib/CodeGen/SjLjEHPrepare.cpp b/llvm/lib/CodeGen/SjLjEHPrepare.cpp
@@ -142,8 +142,8 @@ static void MarkBlocksLiveIn(BasicBlock *BB,
   if (!LiveBBs.insert(BB))
     return; // already been here.
 
-  for (pred_iterator PI = pred_begin(BB), E = pred_end(BB); PI != E; ++PI)
-    MarkBlocksLiveIn(*PI, LiveBBs);
+  for (BasicBlock *Pred : predecessors(BB))
+    MarkBlocksLiveIn(Pred, LiveBBs);
 }
 
 /// substituteLPadValues - Substitute the values returned by the landingpad

diff --git a/llvm/lib/CodeGen/UnreachableBlockElim.cpp b/llvm/lib/CodeGen/UnreachableBlockElim.cpp
@@ -79,8 +79,8 @@ bool UnreachableBlockElim::runOnFunction(Function &F) {
         PN->replaceAllUsesWith(Constant::getNullValue(PN->getType()));
         BB->getInstList().pop_front();
       }
-      for (succ_iterator SI = succ_begin(BB), E = succ_end(BB); SI != E; ++SI)
-        (*SI)->removePredecessor(BB);
+      for (BasicBlock *S : successors(BB))
+        S->removePredecessor(BB);
       BB->dropAllReferences();
     }
 

diff --git a/llvm/lib/IR/BasicBlock.cpp b/llvm/lib/IR/BasicBlock.cpp
@@ -321,10 +321,9 @@ BasicBlock *BasicBlock::splitBasicBlock(iterator I, const Twine &BBName) {
   // successors.  If there were PHI nodes in the successors, then they need to
   // know that incoming branches will be from New, not from Old.
   //
-  for (succ_iterator I = succ_begin(New), E = succ_end(New); I != E; ++I) {
+  for (BasicBlock *Successor : successors(New)) {
     // Loop over any phi nodes in the basic block, updating the BB field of
     // incoming values...
-    BasicBlock *Successor = *I;
     PHINode *PN;
     for (BasicBlock::iterator II = Successor->begin();
          (PN = dyn_cast<PHINode>(II)); ++II) {

diff --git a/llvm/lib/IR/Dominators.cpp b/llvm/lib/IR/Dominators.cpp
@@ -179,9 +179,7 @@ bool DominatorTree::dominates(const BasicBlockEdge &BBE,
   // trivially dominates itself, so we only have to find if it dominates the
   // other predecessors. Since the only way out of X is via NormalDest, X can
   // only properly dominate a node if NormalDest dominates that node too.
-  for (const_pred_iterator PI = pred_begin(End), E = pred_end(End);
-       PI != E; ++PI) {
-    const BasicBlock *BB = *PI;
+  for (const BasicBlock *BB : predecessors(End)) {
     if (BB == Start)
       continue;
 

diff --git a/llvm/lib/IR/Verifier.cpp b/llvm/lib/IR/Verifier.cpp
@@ -2107,8 +2107,8 @@ void Verifier::visitLandingPadInst(LandingPadInst &LPI) {
 
   // The landingpad instruction defines its parent as a landing pad block. The
   // landing pad block may be branched to only by the unwind edge of an invoke.
-  for (pred_iterator I = pred_begin(BB), E = pred_end(BB); I != E; ++I) {
-    const InvokeInst *II = dyn_cast<InvokeInst>((*I)->getTerminator());
+  for (BasicBlock *Pred : predecessors(BB)) {
+    const InvokeInst *II = dyn_cast<InvokeInst>(Pred->getTerminator());
     Assert1(II && II->getUnwindDest() == BB && II->getNormalDest() != BB,
             "Block containing LandingPadInst must be jumped to "
             "only by the unwind edge of an invoke.", &LPI);

diff --git a/llvm/lib/Transforms/IPO/ArgumentPromotion.cpp b/llvm/lib/Transforms/IPO/ArgumentPromotion.cpp
@@ -473,8 +473,7 @@ bool ArgPromotion::isSafeToPromoteArgument(Argument *Arg,
     // Now check every path from the entry block to the load for transparency.
     // To do this, we perform a depth first search on the inverse CFG from the
     // loading block.
-    for (pred_iterator PI = pred_begin(BB), E = pred_end(BB); PI != E; ++PI) {
-      BasicBlock *P = *PI;
+    for (BasicBlock *P : predecessors(BB)) {
       for (idf_ext_iterator<BasicBlock*, SmallPtrSet<BasicBlock*, 16> >
              I = idf_ext_begin(P, TranspBlocks),
              E = idf_ext_end(P, TranspBlocks); I != E; ++I)

diff --git a/llvm/lib/Transforms/IPO/LoopExtractor.cpp b/llvm/lib/Transforms/IPO/LoopExtractor.cpp
@@ -229,9 +229,7 @@ void BlockExtractorPass::SplitLandingPadPreds(Function *F) {
     // Look through the landing pad's predecessors. If one of them ends in an
     // 'invoke', then we want to split the landing pad.
     bool Split = false;
-    for (pred_iterator
-           PI = pred_begin(LPad), PE = pred_end(LPad); PI != PE; ++PI) {
-      BasicBlock *BB = *PI;
+    for (BasicBlock *BB : predecessors(LPad)) {
       if (BB->isLandingPad() && BB != Parent &&
           isa<InvokeInst>(Parent->getTerminator())) {
         Split = true;

diff --git a/llvm/lib/Transforms/IPO/PartialInlining.cpp b/llvm/lib/Transforms/IPO/PartialInlining.cpp
@@ -58,13 +58,12 @@ Function* PartialInliner::unswitchFunction(Function* F) {
   BasicBlock* returnBlock = nullptr;
   BasicBlock* nonReturnBlock = nullptr;
   unsigned returnCount = 0;
-  for (succ_iterator SI = succ_begin(entryBlock), SE = succ_end(entryBlock);
-       SI != SE; ++SI)
-    if (isa<ReturnInst>((*SI)->getTerminator())) {
-      returnBlock = *SI;
+  for (BasicBlock *Succ : successors(entryBlock))
+    if (isa<ReturnInst>(Succ->getTerminator())) {
+      returnBlock = Succ;
       returnCount++;
     } else
-      nonReturnBlock = *SI;
+      nonReturnBlock = Succ;
 
   if (returnCount != 1)
     return nullptr;

diff --git a/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp b/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp
@@ -2718,8 +2718,8 @@ bool InstCombiner::DoOneIteration(Function &F, unsigned Iteration) {
       if (UserParent != BB) {
         bool UserIsSuccessor = false;
         // See if the user is one of our successors.
-        for (succ_iterator SI = succ_begin(BB), E = succ_end(BB); SI != E; ++SI)
-          if (*SI == UserParent) {
+        for (BasicBlock *Succ : successors(BB))
+          if (Succ == UserParent) {
             UserIsSuccessor = true;
             break;
           }

diff --git a/llvm/lib/Transforms/Scalar/DeadStoreElimination.cpp b/llvm/lib/Transforms/Scalar/DeadStoreElimination.cpp
@@ -642,8 +642,7 @@ bool DSE::runOnBasicBlock(BasicBlock &BB) {
 /// 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;
     TerminatorInst *PredTI = Pred->getTerminator();
     if (PredTI->getNumSuccessors() != 1)

diff --git a/llvm/lib/Transforms/Scalar/GVN.cpp b/llvm/lib/Transforms/Scalar/GVN.cpp
@@ -1555,9 +1555,7 @@ bool GVN::PerformLoadPRE(LoadInst *LI, AvailValInBlkVect &ValuesPerBlock,
     FullyAvailableBlocks[UnavailableBlocks[i]] = false;
 
   SmallVector<BasicBlock *, 4> CriticalEdgePred;
-  for (pred_iterator PI = pred_begin(LoadBB), E = pred_end(LoadBB);
-       PI != E; ++PI) {
-    BasicBlock *Pred = *PI;
+  for (BasicBlock *Pred : predecessors(LoadBB)) {
     if (IsValueFullyAvailableInBlock(Pred, FullyAvailableBlocks, 0)) {
       continue;
     }
@@ -2483,9 +2481,7 @@ bool GVN::performPRE(Function &F) {
       BasicBlock *PREPred = nullptr;
       predMap.clear();
 
-      for (pred_iterator PI = pred_begin(CurrentBlock),
-           PE = pred_end(CurrentBlock); PI != PE; ++PI) {
-        BasicBlock *P = *PI;
+      for (BasicBlock *P : predecessors(CurrentBlock)) {
         // We're not interested in PRE where the block is its
         // own predecessor, or in blocks with predecessors
         // that are not reachable.
@@ -2713,14 +2709,13 @@ void GVN::addDeadBlock(BasicBlock *BB) {
     for (SmallVectorImpl<BasicBlock *>::iterator I = Dom.begin(),
            E = Dom.end(); I != E; I++) {
       BasicBlock *B = *I;
-      for (succ_iterator SI = succ_begin(B), SE = succ_end(B); SI != SE; SI++) {
-        BasicBlock *S = *SI;
+      for (BasicBlock *S : successors(B)) {
         if (DeadBlocks.count(S))
           continue;
 
         bool AllPredDead = true;
-        for (pred_iterator PI = pred_begin(S), PE = pred_end(S); PI != PE; PI++)
-          if (!DeadBlocks.count(*PI)) {
+        for (BasicBlock *Pred : predecessors(S))
+          if (!DeadBlocks.count(Pred)) {
             AllPredDead = false;
             break;
           }