Use phi ranges to simplify code. No functionality change intended.

llvm-svn: 321585

10 files changed, 72 insertions, 127 deletions

diff --git a/llvm/lib/Transforms/Scalar/CallSiteSplitting.cpp b/llvm/lib/Transforms/Scalar/CallSiteSplitting.cpp
index 207243231aa..caa73b2ff01 100644
--- a/llvm/lib/Transforms/Scalar/CallSiteSplitting.cpp
+++ b/llvm/lib/Transforms/Scalar/CallSiteSplitting.cpp
@@ -265,15 +265,12 @@ static void splitCallSite(CallSite CS, BasicBlock *PredBB1, BasicBlock *PredBB2,
   CallSite CS2(CallInst2);
 
   // Handle PHIs used as arguments in the call-site.
-  for (auto &PI : *TailBB) {
-    PHINode *PN = dyn_cast<PHINode>(&PI);
-    if (!PN)
-      break;
+  for (PHINode &PN : TailBB->phis()) {
     unsigned ArgNo = 0;
     for (auto &CI : CS.args()) {
-      if (&*CI == PN) {
-        CS1.setArgument(ArgNo, PN->getIncomingValueForBlock(SplitBlock1));
-        CS2.setArgument(ArgNo, PN->getIncomingValueForBlock(SplitBlock2));
+      if (&*CI == &PN) {
+        CS1.setArgument(ArgNo, PN.getIncomingValueForBlock(SplitBlock1));
+        CS2.setArgument(ArgNo, PN.getIncomingValueForBlock(SplitBlock2));
       }
       ++ArgNo;
     }
diff --git a/llvm/lib/Transforms/Scalar/GVNSink.cpp b/llvm/lib/Transforms/Scalar/GVNSink.cpp
index bf92e43c471..5594c29bbd9 100644
--- a/llvm/lib/Transforms/Scalar/GVNSink.cpp
+++ b/llvm/lib/Transforms/Scalar/GVNSink.cpp
@@ -592,12 +592,8 @@ private:
   /// Create a ModelledPHI for each PHI in BB, adding to PHIs.
   void analyzeInitialPHIs(BasicBlock *BB, ModelledPHISet &PHIs,
                           SmallPtrSetImpl<Value *> &PHIContents) {
-    for (auto &I : *BB) {
-      auto *PN = dyn_cast<PHINode>(&I);
-      if (!PN)
-        return;
-
-      auto MPHI = ModelledPHI(PN);
+    for (PHINode &PN : BB->phis()) {
+      auto MPHI = ModelledPHI(&PN);
       PHIs.insert(MPHI);
       for (auto *V : MPHI.getValues())
         PHIContents.insert(V);
diff --git a/llvm/lib/Transforms/Scalar/IndVarSimplify.cpp b/llvm/lib/Transforms/Scalar/IndVarSimplify.cpp
index 74d6014d3e3..221fe57581c 100644
--- a/llvm/lib/Transforms/Scalar/IndVarSimplify.cpp
+++ b/llvm/lib/Transforms/Scalar/IndVarSimplify.cpp
@@ -485,9 +485,8 @@ void IndVarSimplify::rewriteNonIntegerIVs(Loop *L) {
   BasicBlock *Header = L->getHeader();
 
   SmallVector<WeakTrackingVH, 8> PHIs;
-  for (BasicBlock::iterator I = Header->begin();
-       PHINode *PN = dyn_cast<PHINode>(I); ++I)
-    PHIs.push_back(PN);
+  for (PHINode &PN : Header->phis())
+    PHIs.push_back(&PN);
 
   for (unsigned i = 0, e = PHIs.size(); i != e; ++i)
     if (PHINode *PN = dyn_cast_or_null<PHINode>(&*PHIs[i]))
@@ -724,13 +723,12 @@ void IndVarSimplify::rewriteFirstIterationLoopExitValues(Loop *L) {
   assert(LoopHeader && "Invalid loop");
 
   for (auto *ExitBB : ExitBlocks) {
-    BasicBlock::iterator BBI = ExitBB->begin();
     // If there are no more PHI nodes in this exit block, then no more
     // values defined inside the loop are used on this path.
-    while (auto *PN = dyn_cast<PHINode>(BBI++)) {
-      for (unsigned IncomingValIdx = 0, E = PN->getNumIncomingValues();
-          IncomingValIdx != E; ++IncomingValIdx) {
-        auto *IncomingBB = PN->getIncomingBlock(IncomingValIdx);
+    for (PHINode &PN : ExitBB->phis()) {
+      for (unsigned IncomingValIdx = 0, E = PN.getNumIncomingValues();
+           IncomingValIdx != E; ++IncomingValIdx) {
+        auto *IncomingBB = PN.getIncomingBlock(IncomingValIdx);
 
         // We currently only support loop exits from loop header. If the
         // incoming block is not loop header, we need to recursively check
@@ -755,8 +753,7 @@ void IndVarSimplify::rewriteFirstIterationLoopExitValues(Loop *L) {
         if (!L->isLoopInvariant(Cond))
           continue;
 
-        auto *ExitVal =
-            dyn_cast<PHINode>(PN->getIncomingValue(IncomingValIdx));
+        auto *ExitVal = dyn_cast<PHINode>(PN.getIncomingValue(IncomingValIdx));
 
         // Only deal with PHIs.
         if (!ExitVal)
@@ -771,8 +768,8 @@ void IndVarSimplify::rewriteFirstIterationLoopExitValues(Loop *L) {
         if (PreheaderIdx != -1) {
           assert(ExitVal->getParent() == LoopHeader &&
                  "ExitVal must be in loop header");
-          PN->setIncomingValue(IncomingValIdx,
-              ExitVal->getIncomingValue(PreheaderIdx));
+          PN.setIncomingValue(IncomingValIdx,
+                              ExitVal->getIncomingValue(PreheaderIdx));
         }
       }
     }
diff --git a/llvm/lib/Transforms/Scalar/InductiveRangeCheckElimination.cpp b/llvm/lib/Transforms/Scalar/InductiveRangeCheckElimination.cpp
index 5c4d55bfbb2..cf98088111b 100644
--- a/llvm/lib/Transforms/Scalar/InductiveRangeCheckElimination.cpp
+++ b/llvm/lib/Transforms/Scalar/InductiveRangeCheckElimination.cpp
@@ -1174,13 +1174,9 @@ void LoopConstrainer::cloneLoop(LoopConstrainer::ClonedLoop &Result,
       if (OriginalLoop.contains(SBB))
         continue; // not an exit block
 
-      for (Instruction &I : *SBB) {
-        auto *PN = dyn_cast<PHINode>(&I);
-        if (!PN)
-          break;
-
-        Value *OldIncoming = PN->getIncomingValueForBlock(OriginalBB);
-        PN->addIncoming(GetClonedValue(OldIncoming), ClonedBB);
+      for (PHINode &PN : SBB->phis()) {
+        Value *OldIncoming = PN.getIncomingValueForBlock(OriginalBB);
+        PN.addIncoming(GetClonedValue(OldIncoming), ClonedBB);
       }
     }
   }
@@ -1327,16 +1323,12 @@ LoopConstrainer::RewrittenRangeInfo LoopConstrainer::changeIterationSpaceEnd(
   // We emit PHI nodes into `RRI.PseudoExit' that compute the "latest" value of
   // each of the PHI nodes in the loop header.  This feeds into the initial
   // value of the same PHI nodes if/when we continue execution.
-  for (Instruction &I : *LS.Header) {
-    auto *PN = dyn_cast<PHINode>(&I);
-    if (!PN)
-      break;
-
-    PHINode *NewPHI = PHINode::Create(PN->getType(), 2, PN->getName() + ".copy",
+  for (PHINode &PN : LS.Header->phis()) {
+    PHINode *NewPHI = PHINode::Create(PN.getType(), 2, PN.getName() + ".copy",
                                       BranchToContinuation);
 
-    NewPHI->addIncoming(PN->getIncomingValueForBlock(Preheader), Preheader);
-    NewPHI->addIncoming(PN->getIncomingValueForBlock(LS.Latch),
+    NewPHI->addIncoming(PN.getIncomingValueForBlock(Preheader), Preheader);
+    NewPHI->addIncoming(PN.getIncomingValueForBlock(LS.Latch),
                         RRI.ExitSelector);
     RRI.PHIValuesAtPseudoExit.push_back(NewPHI);
   }
@@ -1348,12 +1340,8 @@ LoopConstrainer::RewrittenRangeInfo LoopConstrainer::changeIterationSpaceEnd(
 
   // The latch exit now has a branch from `RRI.ExitSelector' instead of
   // `LS.Latch'.  The PHI nodes need to be updated to reflect that.
-  for (Instruction &I : *LS.LatchExit) {
-    if (PHINode *PN = dyn_cast<PHINode>(&I))
-      replacePHIBlock(PN, LS.Latch, RRI.ExitSelector);
-    else
-      break;
-  }
+  for (PHINode &PN : LS.LatchExit->phis())
+    replacePHIBlock(&PN, LS.Latch, RRI.ExitSelector);
 
   return RRI;
 }
@@ -1362,15 +1350,10 @@ void LoopConstrainer::rewriteIncomingValuesForPHIs(
     LoopStructure &LS, BasicBlock *ContinuationBlock,
     const LoopConstrainer::RewrittenRangeInfo &RRI) const {
   unsigned PHIIndex = 0;
-  for (Instruction &I : *LS.Header) {
-    auto *PN = dyn_cast<PHINode>(&I);
-    if (!PN)
-      break;
-
-    for (unsigned i = 0, e = PN->getNumIncomingValues(); i < e; ++i)
-      if (PN->getIncomingBlock(i) == ContinuationBlock)
-        PN->setIncomingValue(i, RRI.PHIValuesAtPseudoExit[PHIIndex++]);
-  }
+  for (PHINode &PN : LS.Header->phis())
+    for (unsigned i = 0, e = PN.getNumIncomingValues(); i < e; ++i)
+      if (PN.getIncomingBlock(i) == ContinuationBlock)
+        PN.setIncomingValue(i, RRI.PHIValuesAtPseudoExit[PHIIndex++]);
 
   LS.IndVarStart = RRI.IndVarEnd;
 }
@@ -1381,14 +1364,9 @@ BasicBlock *LoopConstrainer::createPreheader(const LoopStructure &LS,
   BasicBlock *Preheader = BasicBlock::Create(Ctx, Tag, &F, LS.Header);
   BranchInst::Create(LS.Header, Preheader);
 
-  for (Instruction &I : *LS.Header) {
-    auto *PN = dyn_cast<PHINode>(&I);
-    if (!PN)
-      break;
-
-    for (unsigned i = 0, e = PN->getNumIncomingValues(); i < e; ++i)
-      replacePHIBlock(PN, OldPreheader, Preheader);
-  }
+  for (PHINode &PN : LS.Header->phis())
+    for (unsigned i = 0, e = PN.getNumIncomingValues(); i < e; ++i)
+      replacePHIBlock(&PN, OldPreheader, Preheader);
 
   return Preheader;
 }
diff --git a/llvm/lib/Transforms/Scalar/JumpThreading.cpp b/llvm/lib/Transforms/Scalar/JumpThreading.cpp
index 1476f7850cf..141c9938bf8 100644
--- a/llvm/lib/Transforms/Scalar/JumpThreading.cpp
+++ b/llvm/lib/Transforms/Scalar/JumpThreading.cpp
@@ -1800,11 +1800,10 @@ static void AddPHINodeEntriesForMappedBlock(BasicBlock *PHIBB,
                                             BasicBlock *OldPred,
                                             BasicBlock *NewPred,
                                      DenseMap<Instruction*, Value*> &ValueMap) {
-  for (BasicBlock::iterator PNI = PHIBB->begin();
-       PHINode *PN = dyn_cast<PHINode>(PNI); ++PNI) {
+  for (PHINode &PN : PHIBB->phis()) {
     // Ok, we have a PHI node.  Figure out what the incoming value was for the
     // DestBlock.
-    Value *IV = PN->getIncomingValueForBlock(OldPred);
+    Value *IV = PN.getIncomingValueForBlock(OldPred);
 
     // Remap the value if necessary.
     if (Instruction *Inst = dyn_cast<Instruction>(IV)) {
@@ -1813,7 +1812,7 @@ static void AddPHINodeEntriesForMappedBlock(BasicBlock *PHIBB,
         IV = I->second;
     }
 
-    PN->addIncoming(IV, NewPred);
+    PN.addIncoming(IV, NewPred);
   }
 }
 
diff --git a/llvm/lib/Transforms/Scalar/LoopDeletion.cpp b/llvm/lib/Transforms/Scalar/LoopDeletion.cpp
index 82604a8842b..15cd1086f20 100644
--- a/llvm/lib/Transforms/Scalar/LoopDeletion.cpp
+++ b/llvm/lib/Transforms/Scalar/LoopDeletion.cpp
@@ -49,11 +49,10 @@ static bool isLoopDead(Loop *L, ScalarEvolution &SE,
   // must pass through a PHI in the exit block, meaning that this check is
   // sufficient to guarantee that no loop-variant values are used outside
   // of the loop.
-  BasicBlock::iterator BI = ExitBlock->begin();
   bool AllEntriesInvariant = true;
   bool AllOutgoingValuesSame = true;
-  while (PHINode *P = dyn_cast<PHINode>(BI)) {
-    Value *incoming = P->getIncomingValueForBlock(ExitingBlocks[0]);
+  for (PHINode &P : ExitBlock->phis()) {
+    Value *incoming = P.getIncomingValueForBlock(ExitingBlocks[0]);
 
     // Make sure all exiting blocks produce the same incoming value for the exit
     // block.  If there are different incoming values for different exiting
@@ -61,7 +60,7 @@ static bool isLoopDead(Loop *L, ScalarEvolution &SE,
     // be used.
     AllOutgoingValuesSame =
         all_of(makeArrayRef(ExitingBlocks).slice(1), [&](BasicBlock *BB) {
-          return incoming == P->getIncomingValueForBlock(BB);
+          return incoming == P.getIncomingValueForBlock(BB);
         });
 
     if (!AllOutgoingValuesSame)
@@ -72,8 +71,6 @@ static bool isLoopDead(Loop *L, ScalarEvolution &SE,
         AllEntriesInvariant = false;
         break;
       }
-
-    ++BI;
   }
 
   if (Changed)
@@ -162,11 +159,9 @@ static LoopDeletionResult deleteLoopIfDead(Loop *L, DominatorTree &DT,
   if (ExitBlock && isLoopNeverExecuted(L)) {
     DEBUG(dbgs() << "Loop is proven to never execute, delete it!");
     // Set incoming value to undef for phi nodes in the exit block.
-    BasicBlock::iterator BI = ExitBlock->begin();
-    while (PHINode *P = dyn_cast<PHINode>(BI)) {
-      for (unsigned i = 0; i < P->getNumIncomingValues(); i++)
-        P->setIncomingValue(i, UndefValue::get(P->getType()));
-      BI++;
+    for (PHINode &P : ExitBlock->phis()) {
+      std::fill(P.incoming_values().begin(), P.incoming_values().end(),
+                UndefValue::get(P.getType()));
     }
     deleteDeadLoop(L, &DT, &SE, &LI);
     ++NumDeleted;
diff --git a/llvm/lib/Transforms/Scalar/LoopStrengthReduce.cpp b/llvm/lib/Transforms/Scalar/LoopStrengthReduce.cpp
index 953854c8b7b..ff3e9eef16d 100644
--- a/llvm/lib/Transforms/Scalar/LoopStrengthReduce.cpp
+++ b/llvm/lib/Transforms/Scalar/LoopStrengthReduce.cpp
@@ -857,12 +857,11 @@ static MemAccessTy getAccessType(const TargetTransformInfo &TTI,
 
 /// Return true if this AddRec is already a phi in its loop.
 static bool isExistingPhi(const SCEVAddRecExpr *AR, ScalarEvolution &SE) {
-  for (BasicBlock::iterator I = AR->getLoop()->getHeader()->begin();
-       PHINode *PN = dyn_cast<PHINode>(I); ++I) {
-    if (SE.isSCEVable(PN->getType()) &&
-        (SE.getEffectiveSCEVType(PN->getType()) ==
+  for (PHINode &PN : AR->getLoop()->getHeader()->phis()) {
+    if (SE.isSCEVable(PN.getType()) &&
+        (SE.getEffectiveSCEVType(PN.getType()) ==
          SE.getEffectiveSCEVType(AR->getType())) &&
-        SE.getSCEV(PN) == AR)
+        SE.getSCEV(&PN) == AR)
       return true;
   }
   return false;
@@ -3013,15 +3012,14 @@ void LSRInstance::CollectChains() {
     } // Continue walking down the instructions.
   } // Continue walking down the domtree.
   // Visit phi backedges to determine if the chain can generate the IV postinc.
-  for (BasicBlock::iterator I = L->getHeader()->begin();
-       PHINode *PN = dyn_cast<PHINode>(I); ++I) {
-    if (!SE.isSCEVable(PN->getType()))
+  for (PHINode &PN : L->getHeader()->phis()) {
+    if (!SE.isSCEVable(PN.getType()))
       continue;
 
     Instruction *IncV =
-      dyn_cast<Instruction>(PN->getIncomingValueForBlock(L->getLoopLatch()));
+        dyn_cast<Instruction>(PN.getIncomingValueForBlock(L->getLoopLatch()));
     if (IncV)
-      ChainInstruction(PN, IncV, ChainUsersVec);
+      ChainInstruction(&PN, IncV, ChainUsersVec);
   }
   // Remove any unprofitable chains.
   unsigned ChainIdx = 0;
@@ -3152,12 +3150,11 @@ void LSRInstance::GenerateIVChain(const IVChain &Chain, SCEVExpander &Rewriter,
   // If LSR created a new, wider phi, we may also replace its postinc. We only
   // do this if we also found a wide value for the head of the chain.
   if (isa<PHINode>(Chain.tailUserInst())) {
-    for (BasicBlock::iterator I = L->getHeader()->begin();
-         PHINode *Phi = dyn_cast<PHINode>(I); ++I) {
-      if (!isCompatibleIVType(Phi, IVSrc))
+    for (PHINode &Phi : L->getHeader()->phis()) {
+      if (!isCompatibleIVType(&Phi, IVSrc))
         continue;
       Instruction *PostIncV = dyn_cast<Instruction>(
-        Phi->getIncomingValueForBlock(L->getLoopLatch()));
+          Phi.getIncomingValueForBlock(L->getLoopLatch()));
       if (!PostIncV || (SE.getSCEV(PostIncV) != SE.getSCEV(IVSrc)))
         continue;
       Value *IVOper = IVSrc;
@@ -3168,7 +3165,7 @@ void LSRInstance::GenerateIVChain(const IVChain &Chain, SCEVExpander &Rewriter,
         Builder.SetCurrentDebugLocation(PostIncV->getDebugLoc());
         IVOper = Builder.CreatePointerCast(IVSrc, PostIncTy, "lsr.chain");
       }
-      Phi->replaceUsesOfWith(PostIncV, IVOper);
+      Phi.replaceUsesOfWith(PostIncV, IVOper);
       DeadInsts.emplace_back(PostIncV);
     }
   }
diff --git a/llvm/lib/Transforms/Scalar/LoopUnswitch.cpp b/llvm/lib/Transforms/Scalar/LoopUnswitch.cpp
index bd468338a1d..f2405d9b0c0 100644
--- a/llvm/lib/Transforms/Scalar/LoopUnswitch.cpp
+++ b/llvm/lib/Transforms/Scalar/LoopUnswitch.cpp
@@ -1274,12 +1274,11 @@ void LoopUnswitch::UnswitchNontrivialCondition(Value *LIC, Constant *Val,
 
     // If the successor of the exit block had PHI nodes, add an entry for
     // NewExit.
-    for (BasicBlock::iterator I = ExitSucc->begin();
-         PHINode *PN = dyn_cast<PHINode>(I); ++I) {
-      Value *V = PN->getIncomingValueForBlock(ExitBlocks[i]);
+    for (PHINode &PN : ExitSucc->phis()) {
+      Value *V = PN.getIncomingValueForBlock(ExitBlocks[i]);
       ValueToValueMapTy::iterator It = VMap.find(V);
       if (It != VMap.end()) V = It->second;
-      PN->addIncoming(V, NewExit);
+      PN.addIncoming(V, NewExit);
     }
 
     if (LandingPadInst *LPad = NewExit->getLandingPadInst()) {
@@ -1496,10 +1495,9 @@ void LoopUnswitch::RewriteLoopBodyWithConditionConstant(Loop *L, Value *LIC,
     BranchInst::Create(Abort, OldSISucc,
                        ConstantInt::getTrue(Context), NewSISucc);
     // Release the PHI operands for this edge.
-    for (BasicBlock::iterator II = NewSISucc->begin();
-         PHINode *PN = dyn_cast<PHINode>(II); ++II)
-      PN->setIncomingValue(PN->getBasicBlockIndex(Switch),
-                           UndefValue::get(PN->getType()));
+    for (PHINode &PN : NewSISucc->phis())
+      PN.setIncomingValue(PN.getBasicBlockIndex(Switch),
+                          UndefValue::get(PN.getType()));
     // Tell the domtree about the new block. We don't fully update the
     // domtree here -- instead we force it to do a full recomputation
     // after the pass is complete -- but we do need to inform it of
diff --git a/llvm/lib/Transforms/Scalar/SCCP.cpp b/llvm/lib/Transforms/Scalar/SCCP.cpp
index 66608ec631f..9dc550ceaec 100644
--- a/llvm/lib/Transforms/Scalar/SCCP.cpp
+++ b/llvm/lib/Transforms/Scalar/SCCP.cpp
@@ -523,10 +523,8 @@ private:
       DEBUG(dbgs() << "Marking Edge Executable: " << Source->getName()
             << " -> " << Dest->getName() << '\n');
 
-      PHINode *PN;
-      for (BasicBlock::iterator I = Dest->begin();
-           (PN = dyn_cast<PHINode>(I)); ++I)
-        visitPHINode(*PN);
+      for (PHINode &PN : Dest->phis())
+        visitPHINode(PN);
     }
   }
 
diff --git a/llvm/lib/Transforms/Scalar/SimpleLoopUnswitch.cpp b/llvm/lib/Transforms/Scalar/SimpleLoopUnswitch.cpp
index 3d0fca0bc3a..aba732bc413 100644
--- a/llvm/lib/Transforms/Scalar/SimpleLoopUnswitch.cpp
+++ b/llvm/lib/Transforms/Scalar/SimpleLoopUnswitch.cpp
@@ -271,19 +271,14 @@ static bool areLoopExitPHIsLoopInvariant(Loop &L, BasicBlock &ExitingBB,
 static void rewritePHINodesForUnswitchedExitBlock(BasicBlock &UnswitchedBB,
                                                   BasicBlock &OldExitingBB,
                                                   BasicBlock &OldPH) {
-  for (Instruction &I : UnswitchedBB) {
-    auto *PN = dyn_cast<PHINode>(&I);
-    if (!PN)
-      // No more PHIs to check.
-      break;
-
+  for (PHINode &PN : UnswitchedBB.phis()) {
     // When the loop exit is directly unswitched we just need to update the
     // incoming basic block. We loop to handle weird cases with repeated
     // incoming blocks, but expect to typically only have one operand here.
-    for (auto i : seq<int>(0, PN->getNumOperands())) {
-      assert(PN->getIncomingBlock(i) == &OldExitingBB &&
+    for (auto i : seq<int>(0, PN.getNumOperands())) {
+      assert(PN.getIncomingBlock(i) == &OldExitingBB &&
              "Found incoming block different from unique predecessor!");
-      PN->setIncomingBlock(i, &OldPH);
+      PN.setIncomingBlock(i, &OldPH);
     }
   }
 }
@@ -302,14 +297,9 @@ static void rewritePHINodesForExitAndUnswitchedBlocks(BasicBlock &ExitBB,
   assert(&ExitBB != &UnswitchedBB &&
          "Must have different loop exit and unswitched blocks!");
   Instruction *InsertPt = &*UnswitchedBB.begin();
-  for (Instruction &I : ExitBB) {
-    auto *PN = dyn_cast<PHINode>(&I);
-    if (!PN)
-      // No more PHIs to check.
-      break;
-
-    auto *NewPN = PHINode::Create(PN->getType(), /*NumReservedValues*/ 2,
-                                  PN->getName() + ".split", InsertPt);
+  for (PHINode &PN : ExitBB.phis()) {
+    auto *NewPN = PHINode::Create(PN.getType(), /*NumReservedValues*/ 2,
+                                  PN.getName() + ".split", InsertPt);
 
     // Walk backwards over the old PHI node's inputs to minimize the cost of
     // removing each one. We have to do this weird loop manually so that we
@@ -320,18 +310,18 @@ static void rewritePHINodesForExitAndUnswitchedBlocks(BasicBlock &ExitBB,
     // allowed us to create a single entry for a predecessor block without
     // having separate entries for each "edge" even though these edges are
     // required to produce identical results.
-    for (int i = PN->getNumIncomingValues() - 1; i >= 0; --i) {
-      if (PN->getIncomingBlock(i) != &OldExitingBB)
+    for (int i = PN.getNumIncomingValues() - 1; i >= 0; --i) {
+      if (PN.getIncomingBlock(i) != &OldExitingBB)
         continue;
 
-      Value *Incoming = PN->removeIncomingValue(i);
+      Value *Incoming = PN.removeIncomingValue(i);
       NewPN->addIncoming(Incoming, &OldPH);
     }
 
     // Now replace the old PHI with the new one and wire the old one in as an
     // input to the new one.
-    PN->replaceAllUsesWith(NewPN);
-    NewPN->addIncoming(PN, &ExitBB);
+    PN.replaceAllUsesWith(NewPN);
+    NewPN->addIncoming(&PN, &ExitBB);
   }
 }