commit c7fc81e6595865296738fe0f8ffe692ea41b1ffc
author Benjamin Kramer <benny.kra@googlemail.com> Sat Dec 30 15:27:33 2017 +0000
committer Benjamin Kramer <benny.kra@googlemail.com> Sat Dec 30 15:27:33 2017 +0000
tree 9c14093b59b87a53d42ecbeb9c263c85f46f97e3
parent 06f6d262f99d4bc13739eb224084d239f5445682

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

llvm-svn: 321585

llvm/lib/Transforms/Scalar/LoopStrengthReduce.cpp

diff --git a/llvm/lib/Transforms/Scalar/LoopStrengthReduce.cpp b/llvm/lib/Transforms/Scalar/LoopStrengthReduce.cpp
index 953854c..ff3e9ee 100644
--- a/llvm/lib/Transforms/Scalar/LoopStrengthReduce.cpp
+++ b/llvm/lib/Transforms/Scalar/LoopStrengthReduce.cpp
@@ -857,12 +857,11 @@
 
 /// 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 @@
     } // 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 @@
   // 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 @@
         Builder.SetCurrentDebugLocation(PostIncV->getDebugLoc());
         IVOper = Builder.CreatePointerCast(IVSrc, PostIncTy, "lsr.chain");
       }
-      Phi->replaceUsesOfWith(PostIncV, IVOper);
+      Phi.replaceUsesOfWith(PostIncV, IVOper);
       DeadInsts.emplace_back(PostIncV);
     }
   }