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

llvm-svn: 124245

2 files changed, 25 insertions, 0 deletions

diff --git a/llvm/lib/CodeGen/SelectionDAG/SDNodeDbgValue.h b/llvm/lib/CodeGen/SelectionDAG/SDNodeDbgValue.h
index 2dcb2295732..e5cd23a6c9f 100644
--- a/llvm/lib/CodeGen/SelectionDAG/SDNodeDbgValue.h
+++ b/llvm/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; }
 
diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
index f6aea1f7956..e751e22a81b 100644
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
+++ b/llvm/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
 //===----------------------------------------------------------------------===//