// Create the node.
SDNode *Res = 0;
- if (Opcode == OPC_MorphNodeTo) {
+ if (Opcode != OPC_MorphNodeTo) {
+ // If this is a normal EmitNode command, just create the new node and
+ // add the results to the RecordedNodes list.
+ Res = CurDAG->getMachineNode(TargetOpc, NodeToMatch->getDebugLoc(),
+ VTList, Ops.data(), Ops.size());
+
+ // Add all the non-flag/non-chain results to the RecordedNodes list.
+ for (unsigned i = 0, e = VTs.size(); i != e; ++i) {
+ if (VTs[i] == MVT::Other || VTs[i] == MVT::Flag) break;
+ RecordedNodes.push_back(SDValue(Res, i));
+ }
+
+ } else {
// It is possible we're using MorphNodeTo to replace a node with no
// normal results with one that has a normal result (or we could be
// adding a chain) and the input could have flags and chains as well.
Res = CurDAG->MorphNodeTo(NodeToMatch, ~TargetOpc, VTList,
Ops.data(), Ops.size());
- // Reset the node ID, to the isel, this should be just like a newly
- // allocated machine node.
- Res->setNodeId(-1);
+
+ // MorphNodeTo can operate in two ways: if an existing node with the
+ // specified operands exists, it can just return it. Otherwise, it
+ // updates the node in place to have the requested operands.
+ if (Res == NodeToMatch) {
+ // If we updated the node in place, reset the node ID. To the isel,
+ // this should be just like a newly allocated machine node.
+ Res->setNodeId(-1);
+ }
// FIXME: Whether the selected node has a flag result should come from
// flags on the node.
// Move the flag if needed.
if (OldFlagResultNo != -1 &&
(unsigned)OldFlagResultNo != ResNumResults-1)
- ReplaceUses(SDValue(Res, OldFlagResultNo),
+ ReplaceUses(SDValue(NodeToMatch, OldFlagResultNo),
SDValue(Res, ResNumResults-1));
--ResNumResults;
}
// Move the chain reference if needed.
if ((EmitNodeInfo & OPFL_Chain) && OldChainResultNo != -1 &&
(unsigned)OldChainResultNo != ResNumResults-1)
- ReplaceUses(SDValue(Res, OldChainResultNo),
+ ReplaceUses(SDValue(NodeToMatch, OldChainResultNo),
SDValue(Res, ResNumResults-1));
- } else {
- Res = CurDAG->getMachineNode(TargetOpc, NodeToMatch->getDebugLoc(),
- VTList, Ops.data(), Ops.size());
-
- // Add all the non-flag/non-chain results to the RecordedNodes list.
- for (unsigned i = 0, e = VTs.size(); i != e; ++i) {
- if (VTs[i] == MVT::Other || VTs[i] == MVT::Flag) break;
- RecordedNodes.push_back(SDValue(Res, i));
+
+ if (Res != NodeToMatch) {
+ // Otherwise, no replacement happened because the node already exists.
+ ReplaceUses(NodeToMatch, Res);
}
}
// Update chain and flag uses.
UpdateChainsAndFlags(NodeToMatch, InputChain, ChainNodesMatched,
InputFlag, FlagResultNodesMatched, true);
- return Res;
+ return 0;
}
continue;