diff options
Diffstat (limited to 'llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp')
| -rw-r--r-- | llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp b/llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp index 9732a17..b209aecf 100644 --- a/llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp +++ b/llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp @@ -9044,7 +9044,9 @@ void TargetLowering::expandUADDSUBO( if (IsAdd && isOneConstant(RHS)) { // Special case: uaddo X, 1 overflowed if X+1 is 0. This potential reduces // the live range of X. We assume comparing with 0 is cheap. - // TODO: This generalizes to (X + C) < C. + // The general case (X + C) < C is not necessarily beneficial. Although we + // reduce the live range of X, we may introduce the materialization of + // constant C. SetCC = DAG.getSetCC(dl, SetCCType, Result, DAG.getConstant(0, dl, Node->getValueType(0)), ISD::SETEQ); |