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

llvm-svn: 321585

2 files changed, 18 insertions, 35 deletions

diff --git a/llvm/lib/Analysis/ScalarEvolution.cpp b/llvm/lib/Analysis/ScalarEvolution.cpp
index 14bfe0d17ac..10b5c74e378 100644
--- a/llvm/lib/Analysis/ScalarEvolution.cpp
+++ b/llvm/lib/Analysis/ScalarEvolution.cpp
@@ -6402,9 +6402,8 @@ PushLoopPHIs(const Loop *L, SmallVectorImpl<Instruction *> &Worklist) {
   BasicBlock *Header = L->getHeader();
 
   // Push all Loop-header PHIs onto the Worklist stack.
-  for (BasicBlock::iterator I = Header->begin();
-       PHINode *PN = dyn_cast<PHINode>(I); ++I)
-    Worklist.push_back(PN);
+  for (PHINode &PN : Header->phis())
+    Worklist.push_back(&PN);
 }
 
 const ScalarEvolution::BackedgeTakenInfo &
@@ -7638,12 +7637,9 @@ ScalarEvolution::getConstantEvolutionLoopExitValue(PHINode *PN,
   if (!Latch)
     return nullptr;
 
-  for (auto &I : *Header) {
-    PHINode *PHI = dyn_cast<PHINode>(&I);
-    if (!PHI) break;
-    auto *StartCST = getOtherIncomingValue(PHI, Latch);
-    if (!StartCST) continue;
-    CurrentIterVals[PHI] = StartCST;
+  for (PHINode &PHI : Header->phis()) {
+    if (auto *StartCST = getOtherIncomingValue(&PHI, Latch))
+      CurrentIterVals[&PHI] = StartCST;
   }
   if (!CurrentIterVals.count(PN))
     return RetVal = nullptr;
@@ -7720,13 +7716,9 @@ const SCEV *ScalarEvolution::computeExitCountExhaustively(const Loop *L,
   BasicBlock *Latch = L->getLoopLatch();
   assert(Latch && "Should follow from NumIncomingValues == 2!");
 
-  for (auto &I : *Header) {
-    PHINode *PHI = dyn_cast<PHINode>(&I);
-    if (!PHI)
-      break;
-    auto *StartCST = getOtherIncomingValue(PHI, Latch);
-    if (!StartCST) continue;
-    CurrentIterVals[PHI] = StartCST;
+  for (PHINode &PHI : Header->phis()) {
+    if (auto *StartCST = getOtherIncomingValue(&PHI, Latch))
+      CurrentIterVals[&PHI] = StartCST;
   }
   if (!CurrentIterVals.count(PN))
     return getCouldNotCompute();
diff --git a/llvm/lib/Analysis/ScalarEvolutionExpander.cpp b/llvm/lib/Analysis/ScalarEvolutionExpander.cpp
index 3ceda677ba6..53ce33bacbe 100644
--- a/llvm/lib/Analysis/ScalarEvolutionExpander.cpp
+++ b/llvm/lib/Analysis/ScalarEvolutionExpander.cpp
@@ -1154,16 +1154,11 @@ SCEVExpander::getAddRecExprPHILiterally(const SCEVAddRecExpr *Normalized,
         IVIncInsertLoop &&
         SE.DT.properlyDominates(LatchBlock, IVIncInsertLoop->getHeader());
 
-    for (auto &I : *L->getHeader()) {
-      auto *PN = dyn_cast<PHINode>(&I);
-      // Found first non-phi, the rest of instructions are also not Phis.
-      if (!PN)
-        break;
-
-      if (!SE.isSCEVable(PN->getType()))
+    for (PHINode &PN : L->getHeader()->phis()) {
+      if (!SE.isSCEVable(PN.getType()))
         continue;
 
-      const SCEVAddRecExpr *PhiSCEV = dyn_cast<SCEVAddRecExpr>(SE.getSCEV(PN));
+      const SCEVAddRecExpr *PhiSCEV = dyn_cast<SCEVAddRecExpr>(SE.getSCEV(&PN));
       if (!PhiSCEV)
         continue;
 
@@ -1175,16 +1170,16 @@ SCEVExpander::getAddRecExprPHILiterally(const SCEVAddRecExpr *Normalized,
           continue;
 
       Instruction *TempIncV =
-          cast<Instruction>(PN->getIncomingValueForBlock(LatchBlock));
+          cast<Instruction>(PN.getIncomingValueForBlock(LatchBlock));
 
       // Check whether we can reuse this PHI node.
       if (LSRMode) {
-        if (!isExpandedAddRecExprPHI(PN, TempIncV, L))
+        if (!isExpandedAddRecExprPHI(&PN, TempIncV, L))
           continue;
         if (L == IVIncInsertLoop && !hoistIVInc(TempIncV, IVIncInsertPos))
           continue;
       } else {
-        if (!isNormalAddRecExprPHI(PN, TempIncV, L))
+        if (!isNormalAddRecExprPHI(&PN, TempIncV, L))
           continue;
       }
 
@@ -1193,7 +1188,7 @@ SCEVExpander::getAddRecExprPHILiterally(const SCEVAddRecExpr *Normalized,
         IncV = TempIncV;
         TruncTy = nullptr;
         InvertStep = false;
-        AddRecPhiMatch = PN;
+        AddRecPhiMatch = &PN;
         break;
       }
 
@@ -1203,7 +1198,7 @@ SCEVExpander::getAddRecExprPHILiterally(const SCEVAddRecExpr *Normalized,
           canBeCheaplyTransformed(SE, PhiSCEV, Normalized, InvertStep)) {
         // Record the phi node. But don't stop we might find an exact match
         // later.
-        AddRecPhiMatch = PN;
+        AddRecPhiMatch = &PN;
         IncV = TempIncV;
         TruncTy = SE.getEffectiveSCEVType(Normalized->getType());
       }
@@ -1863,12 +1858,8 @@ SCEVExpander::replaceCongruentIVs(Loop *L, const DominatorTree *DT,
                                   const TargetTransformInfo *TTI) {
   // Find integer phis in order of increasing width.
   SmallVector<PHINode*, 8> Phis;
-  for (auto &I : *L->getHeader()) {
-    if (auto *PN = dyn_cast<PHINode>(&I))
-      Phis.push_back(PN);
-    else
-      break;
-  }
+  for (PHINode &PN : L->getHeader()->phis())
+    Phis.push_back(&PN);
 
   if (TTI)
     std::sort(Phis.begin(), Phis.end(), [](Value *LHS, Value *RHS) {