Use LoopInfo's getLoopLatch() instead of doing what it does manualy.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@66467 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Transforms/Scalar/LoopStrengthReduce.cpp b/lib/Transforms/Scalar/LoopStrengthReduce.cpp
index b64c689df599ce1385b376360cdc4cb8156f9f0c..f3312151c489bbbe989644e653c6ed5e04deff00 100644 (file)
--- a/lib/Transforms/Scalar/LoopStrengthReduce.cpp
+++ b/lib/Transforms/Scalar/LoopStrengthReduce.cpp
@@ -1599,17 +1599,12 @@ static PHINode *InsertAffinePhi(SCEVHandle Start, SCEVHandle Step,
 
   BasicBlock *Header = L->getHeader();
   BasicBlock *Preheader = L->getLoopPreheader();
+  BasicBlock *LatchBlock = L->getLoopLatch();
 
   PHINode *PN = PHINode::Create(Start->getType(), "lsr.iv", Header->begin());
   PN->addIncoming(Rewriter.expandCodeFor(Start, Preheader->getTerminator()),
                   Preheader);
 
-  pred_iterator HPI = pred_begin(Header);
-  assert(HPI != pred_end(Header) && "Loop with zero preds???");
-  if (!L->contains(*HPI)) ++HPI;
-  assert(HPI != pred_end(Header) && L->contains(*HPI) &&
-         "No backedge in loop?");
-
   // If the stride is negative, insert a sub instead of an add for the
   // increment.
   bool isNegative = isNonConstantNegative(Step);
@@ -1622,17 +1617,14 @@ static PHINode *InsertAffinePhi(SCEVHandle Start, SCEVHandle Step,
   Value *StepV = Rewriter.expandCodeFor(IncAmount, Preheader->getTerminator());
   if (isNegative) {
     IncV = BinaryOperator::CreateSub(PN, StepV, "lsr.iv.next",
-                                     (*HPI)->getTerminator());
+                                     LatchBlock->getTerminator());
   } else {
     IncV = BinaryOperator::CreateAdd(PN, StepV, "lsr.iv.next",
-                                     (*HPI)->getTerminator());
+                                     LatchBlock->getTerminator());
   }
   if (!isa<ConstantInt>(StepV)) ++NumVariable;
 
-  pred_iterator PI = pred_begin(Header);
-  if (*PI == L->getLoopPreheader())
-    ++PI;
-  PN->addIncoming(IncV, *PI);
+  PN->addIncoming(IncV, LatchBlock);
 
   ++NumInserted;
   return PN;