[llvm] r177377 - Revert "Cleanup some SCEV logic a bit."

[Andrew Trick]

Author: atrick
Date: Tue Mar 19 00:10:27 2013
New Revision: 177377

URL: http://llvm.org/viewvc/llvm-project?rev=177377&view=rev
Log:
Revert "Cleanup some SCEV logic a bit."

This reverts commit 82cd8f7382322bee7a71cdc31f7a923c44d37d32.

Just add a comment instead!

Modified:
    llvm/trunk/lib/Transforms/Scalar/LoopStrengthReduce.cpp

Modified: llvm/trunk/lib/Transforms/Scalar/LoopStrengthReduce.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/LoopStrengthReduce.cpp?rev=177377&r1=177376&r2=177377&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Scalar/LoopStrengthReduce.cpp (original)
+++ llvm/trunk/lib/Transforms/Scalar/LoopStrengthReduce.cpp Tue Mar 19 00:10:27 2013
@@ -2716,11 +2716,11 @@ void LSRInstance::GenerateIVChain(const
   // by LSR.
   const IVInc &Head = Chain.Incs[0];
   User::op_iterator IVOpEnd = Head.UserInst->op_end();
+  // findIVOperand returns IVOpEnd if it can no longer find a valid IV user.
   User::op_iterator IVOpIter = findIVOperand(Head.UserInst->op_begin(),
                                              IVOpEnd, L, SE);
-  assert(IVOpIter != IVOpEnd && "No IV operands found");
   Value *IVSrc = 0;
-  do {
+  while (IVOpIter != IVOpEnd) {
     IVSrc = getWideOperand(*IVOpIter);
 
     // If this operand computes the expression that the chain needs, we may use
@@ -2736,8 +2736,7 @@ void LSRInstance::GenerateIVChain(const
       break;
     }
     IVOpIter = findIVOperand(llvm::next(IVOpIter), IVOpEnd, L, SE);
-  } while (IVOpIter != IVOpEnd);
-
+  }
   if (IVOpIter == IVOpEnd) {
     // Gracefully give up on this chain.
     DEBUG(dbgs() << "Concealed chain head: " << *Head.UserInst << "\n");