/// DAGSize - Size of DAG being instruction selected.
///
unsigned DAGSize;
+
+ /// ISelPosition - Node iterator marking the current position of
+ /// instruction selection as it procedes through the topologically-sorted
+ /// node list.
+ SelectionDAG::allnodes_iterator ISelPosition;
+
+
+ /// ISelUpdater - helper class to handle updates of the
+ /// instruction selection graph.
+ class ISelUpdater : public SelectionDAG::DAGUpdateListener {
+ SelectionDAG::allnodes_iterator &ISelPosition;
+ public:
+ explicit ISelUpdater(SelectionDAG::allnodes_iterator &isp)
+ : ISelPosition(isp) {}
+
+ /// NodeDeleted - Handle nodes deleted from the graph. If the
+ /// node being deleted is the current ISelPosition node, update
+ /// ISelPosition.
+ ///
+ virtual void NodeDeleted(SDNode *N, SDNode *E) {
+ if (ISelPosition == SelectionDAG::allnodes_iterator(N))
+ ++ISelPosition;
+ }
+
+ /// NodeUpdated - Ignore updates for now.
+ virtual void NodeUpdated(SDNode *N) {}
+ };
+
+ /// ReplaceUses - replace all uses of the old node F with the use
+ /// of the new node T.
+ void ReplaceUses(SDValue F, SDValue T) {
+ ISelUpdater ISU(ISelPosition);
+ CurDAG->ReplaceAllUsesOfValueWith(F, T, &ISU);
+ }
+
+ /// ReplaceUses - replace all uses of the old nodes F with the use
+ /// of the new nodes T.
+ void ReplaceUses(const SDValue *F, const SDValue *T, unsigned Num) {
+ ISelUpdater ISU(ISelPosition);
+ CurDAG->ReplaceAllUsesOfValuesWith(F, T, Num, &ISU);
+ }
+
+ /// ReplaceUses - replace all uses of the old node F with the use
+ /// of the new node T.
+ void ReplaceUses(SDNode *F, SDNode *T) {
+ ISelUpdater ISU(ISelPosition);
+ CurDAG->ReplaceAllUsesWith(F, T, &ISU);
+ }
+
/// SelectInlineAsmMemoryOperands - Calls to this are automatically generated
/// by tblgen. Others should not call it.