diff --git a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp index a2f36f33b45..29a31e4e1d6 100644 --- a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp +++ b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp @@ -137,6 +137,7 @@ namespace { // otherwise - N should be replaced by the returned Operand. // SDOperand visitTokenFactor(SDNode *N); + SDOperand visitMERGE_VALUES(SDNode *N); SDOperand visitADD(SDNode *N); SDOperand visitSUB(SDNode *N); SDOperand visitADDC(SDNode *N); @@ -662,6 +663,7 @@ SDOperand DAGCombiner::visit(SDNode *N) { switch(N->getOpcode()) { default: break; case ISD::TokenFactor: return visitTokenFactor(N); + case ISD::MERGE_VALUES: return visitMERGE_VALUES(N); case ISD::ADD: return visitADD(N); case ISD::SUB: return visitSUB(N); case ISD::ADDC: return visitADDC(N); @@ -837,6 +839,18 @@ SDOperand DAGCombiner::visitTokenFactor(SDNode *N) { return Result; } +/// MERGE_VALUES can always be eliminated. +SDOperand DAGCombiner::visitMERGE_VALUES(SDNode *N) { + WorkListRemover DeadNodes(*this); + for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i) + DAG.ReplaceAllUsesOfValueWith(SDOperand(N, i), N->getOperand(i), + &DeadNodes); + removeFromWorkList(N); + DAG.DeleteNode(N); + return SDOperand(N, 0); // Return N so it doesn't get rechecked! +} + + static SDOperand combineShlAddConstant(SDOperand N0, SDOperand N1, SelectionDAG &DAG) { MVT::ValueType VT = N0.getValueType();