diff options
| author | Chris Lattner <sabre@nondot.org> | 2005-10-11 06:07:15 +0000 |
|---|---|---|
| committer | Chris Lattner <sabre@nondot.org> | 2005-10-11 06:07:15 +0000 |
| commit | 05b57433e68de3ba0f6eb01f4a0271fee3abeb09 (patch) | |
| tree | 9064ce74634e581b8826ad99d03b6edc4ba578ab /lib/CodeGen/SelectionDAG/DAGCombiner.cpp | |
| parent | 04ecf6d65fb5c8703eff8a3dcd5a8208e91318fe (diff) | |
Add a canonicalization that got lost, fixing PowerPC/fold-li.ll:SUB
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@23693 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/CodeGen/SelectionDAG/DAGCombiner.cpp')
| -rw-r--r-- | lib/CodeGen/SelectionDAG/DAGCombiner.cpp | 8 |
1 files changed, 5 insertions, 3 deletions
diff --git a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp index efeee071f0..0098a56a9a 100644 --- a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp +++ b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp @@ -517,9 +517,11 @@ SDOperand DAGCombiner::visitSUB(SDNode *N) { if (N0C && N1C) return DAG.getConstant(N0C->getValue() - N1C->getValue(), N->getValueType(0)); - // fold (sub x, 0) -> x - if (N1C && N1C->isNullValue()) - return N0; + // fold (sub x, c) -> (add x, -c) + if (N1C) + return DAG.getNode(ISD::ADD, N0.getValueType(), N0, + DAG.getConstant(-N1C->getValue(), N0.getValueType())); + // fold (A+B)-A -> B if (N0.getOpcode() == ISD::ADD && N0.getOperand(0) == N1) return N0.getOperand(1); |