From de78866594d7f38cdf4418552b4034cc81d4a803 Mon Sep 17 00:00:00 2001 From: Andrew Trick Date: Tue, 19 Mar 2013 04:14:59 +0000 Subject: [PATCH] Cleanup some SCEV logic a bit. Make the code more obvious to scan-build and humans. llvm-svn: 177375 --- llvm/lib/Transforms/Scalar/LoopStrengthReduce.cpp | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/llvm/lib/Transforms/Scalar/LoopStrengthReduce.cpp b/llvm/lib/Transforms/Scalar/LoopStrengthReduce.cpp index e4f093e1c376..f01af001ca9d 100644 --- a/llvm/lib/Transforms/Scalar/LoopStrengthReduce.cpp +++ b/llvm/lib/Transforms/Scalar/LoopStrengthReduce.cpp @@ -2718,8 +2718,9 @@ void LSRInstance::GenerateIVChain(const IVChain &Chain, SCEVExpander &Rewriter, 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 @@ void LSRInstance::GenerateIVChain(const IVChain &Chain, SCEVExpander &Rewriter, 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");