Cleanup some SCEV logic a bit.
Make the code more obvious to scan-build and humans.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@177375 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/Scalar/LoopStrengthReduce.cpp b/lib/Transforms/Scalar/LoopStrengthReduce.cpp
index e4f093e..f01af00 100644
--- a/lib/Transforms/Scalar/LoopStrengthReduce.cpp
+++ b/lib/Transforms/Scalar/LoopStrengthReduce.cpp
@@ -2718,8 +2718,9 @@
User::op_iterator IVOpEnd = Head.UserInst->op_end();
User::op_iterator IVOpIter = findIVOperand(Head.UserInst->op_begin(),
IVOpEnd, L, SE);
+ assert(IVOpIter != IVOpEnd && "No IV operands found");
Value *IVSrc = 0;
- while (IVOpIter != IVOpEnd) {
+ do {
IVSrc = getWideOperand(*IVOpIter);
// If this operand computes the expression that the chain needs, we may use
@@ -2735,7 +2736,8 @@
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");