diff options
Diffstat (limited to 'llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp')
| -rw-r--r-- | llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp index d9290c6dbe5..5a70deebd68 100644 --- a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp +++ b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp @@ -3715,8 +3715,8 @@ SDValue DAGCombiner::hoistLogicOpWithSameOpcodeHands(SDNode *N) { if (N0.getNumOperands() == 0) return SDValue(); - // FIXME: We need to check number of uses of the operands to not increase - // the instruction count. + // FIXME: We should check number of uses of the operands to not increase + // the instruction count for all transforms. EVT Op0VT = N0.getOperand(0).getValueType(); switch (HandOpcode) { @@ -3725,6 +3725,10 @@ SDValue DAGCombiner::hoistLogicOpWithSameOpcodeHands(SDNode *N) { case ISD::ZERO_EXTEND: case ISD::SIGN_EXTEND: case ISD::BSWAP: + // If both operands have other uses, this transform would create extra + // instructions without eliminating anything. + if (!N0.hasOneUse() && !N1.hasOneUse()) + return SDValue(); // We need matching integer source types. // Do not hoist logic op inside of a vector extend, since it may combine // into a vsetcc. |
