Like the comment says, do not insert cast instructions before phi nodes

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@22586 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Transforms/Scalar/LoopStrengthReduce.cpp

@@ -232,6 +232,10 @@ void LoopStrengthReduce::AnalyzeGetElementPtrUsers(GetElementPtrInst *GEP,
         else
           ++InsertPt;
       }
+      
+      // Do not insert casts into the middle of PHI node blocks.
+      while (isa<PHINode>(InsertPt)) ++InsertPt;
+      
       BP = new CastInst(GEP->getOperand(0), UIntPtrTy,
                         GEP->getOperand(0)->getName(), InsertPt);
     }