prepare for a change I'm about to make

llvm-svn: 31248

1 files changed, 6 insertions, 0 deletions

diff --git a/llvm/lib/Transforms/Scalar/LoopStrengthReduce.cpp b/llvm/lib/Transforms/Scalar/LoopStrengthReduce.cpp
index e498860b5e8..1c6acc6eef8 100644
--- a/llvm/lib/Transforms/Scalar/LoopStrengthReduce.cpp
+++ b/llvm/lib/Transforms/Scalar/LoopStrengthReduce.cpp
@@ -379,6 +379,9 @@ static bool IVUseShouldUsePostIncValue(Instruction *User, Instruction *IV,
   for (unsigned i = 0, e = PN->getNumIncomingValues(); i != e; ++i)
     if (PN->getIncomingValue(i) == IV) {
       SplitCriticalEdge(PN->getIncomingBlock(i), PN->getParent(), P);
+      // Splitting the critical edge can reduce the number of entries in this
+      // PHI.
+      e = PN->getNumIncomingValues();
       if (--NumUses == 0) break;
     }
   
@@ -589,6 +592,9 @@ void BasedUser::RewriteInstructionToUseNewBase(const SCEVHandle &NewBase,
           BasicBlock *NewBB = PN->getIncomingBlock(i);
           NewBB->moveBefore(PN->getParent());
         }
+        
+        // Splitting the edge can reduce the number of PHI entries we have.
+        e = PN->getNumIncomingValues();
       }
 
       Value *&Code = InsertedCode[PN->getIncomingBlock(i)];