Provide an interface to transfer SDDbgValue from one SDNode to another.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124245 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/CodeGen/SelectionDAG.h

@@ -100,6 +100,10 @@ public:
     return DbgValMap[Node];
   }
 
+  void removeSDDbgValues(const SDNode *Node) {
+    DbgValMap.erase(Node);
+  }
+
   typedef SmallVector<SDDbgValue*,32>::iterator DbgIterator;
   DbgIterator DbgBegin() { return DbgValues.begin(); }
   DbgIterator DbgEnd()   { return DbgValues.end(); }
@@ -902,6 +906,9 @@ public:
     return DbgInfo->getSDDbgValues(SD);
   }
   
+  /// TransferDbgValues - Transfer SDDbgValues.
+  void TransferDbgValues(SDValue From, SDValue To);
+
   /// hasDebugValues - Return true if there are any SDDbgValue nodes associated
   /// with this SelectionDAG.
   bool hasDebugValues() const { return !DbgInfo->empty(); }

lib/CodeGen/SelectionDAG/SDNodeDbgValue.h

@@ -83,6 +83,14 @@ public:
   // Returns the SDNode* for a register ref
   SDNode *getSDNode() { assert (kind==SDNODE); return u.s.Node; }
 
+  // setSDNode - If underlying SDNode is replaced by another node then
+  // SelectionDAG can use this to transfer DbgValue.
+  void setSDNode(SDNode *N, unsigned R) { 
+    assert (kind==SDNODE); 
+    u.s.Node = N; 
+    u.s.ResNo = R;
+  }
+
   // Returns the ResNo for a register ref
   unsigned getResNo() { assert (kind==SDNODE); return u.s.ResNo; }
 

lib/CodeGen/SelectionDAG/SelectionDAG.cpp

@@ -5424,6 +5424,23 @@ void SelectionDAG::AddDbgValue(SDDbgValue *DB, SDNode *SD, bool isParameter) {
     SD->setHasDebugValue(true);
 }
 
+/// TransferDbgValues - Transfer SDDbgValues.
+void SelectionDAG::TransferDbgValues(SDValue From, SDValue To) {
+  if (From == To || !From.getNode()->getHasDebugValue())
+    return;
+  SDNode *FromNode = From.getNode();
+  SDNode *ToNode = To.getNode();
+  SmallVector<SDDbgValue*,2> &DVs = GetDbgValues(FromNode);
+  DbgInfo->removeSDDbgValues(FromNode);
+  for (SmallVector<SDDbgValue *, 2>::iterator I = DVs.begin(), E = DVs.end();
+       I != E; ++I) {
+    if ((*I)->getKind() == SDDbgValue::SDNODE) {
+      AddDbgValue(*I, ToNode, false);
+      (*I)->setSDNode(ToNode, To.getResNo());
+    }
+  }
+}
+
 //===----------------------------------------------------------------------===//
 //                              SDNode Class
 //===----------------------------------------------------------------------===//