Add a RegisterMaskSDNode class.

This SelectionDAG node will be attached to call nodes by LowerCall(),
and eventually becomes a MO_RegisterMask MachineOperand on the
MachineInstr representing the call instruction.

LowerCall() will attach a register mask that depends on the calling
convention.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@148436 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/SelectionDAG/SelectionDAG.cpp b/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
index 848ba69..040791b 100644
--- a/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
+++ b/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
@@ -383,7 +383,9 @@
   case ISD::Register:
     ID.AddInteger(cast<RegisterSDNode>(N)->getReg());
     break;
-
+  case ISD::RegisterMask:
+    ID.AddPointer(cast<RegisterMaskSDNode>(N)->getRegMask());
+    break;
   case ISD::SRCVALUE:
     ID.AddPointer(cast<SrcValueSDNode>(N)->getValue());
     break;
@@ -1375,6 +1377,20 @@
   return SDValue(N, 0);
 }
 
+SDValue SelectionDAG::getRegisterMask(const uint32_t *RegMask) {
+  FoldingSetNodeID ID;
+  AddNodeIDNode(ID, ISD::RegisterMask, getVTList(MVT::Untyped), 0, 0);
+  ID.AddPointer(RegMask);
+  void *IP = 0;
+  if (SDNode *E = CSEMap.FindNodeOrInsertPos(ID, IP))
+    return SDValue(E, 0);
+
+  SDNode *N = new (NodeAllocator) RegisterMaskSDNode(RegMask);
+  CSEMap.InsertNode(N, IP);
+  AllNodes.push_back(N);
+  return SDValue(N, 0);
+}
+
 SDValue SelectionDAG::getEHLabel(DebugLoc dl, SDValue Root, MCSymbol *Label) {
   FoldingSetNodeID ID;
   SDValue Ops[] = { Root };
@@ -5946,7 +5962,7 @@
   case ISD::BasicBlock:    return "BasicBlock";
   case ISD::VALUETYPE:     return "ValueType";
   case ISD::Register:      return "Register";
-
+  case ISD::RegisterMask:  return "RegisterMask";
   case ISD::Constant:      return "Constant";
   case ISD::ConstantFP:    return "ConstantFP";
   case ISD::GlobalAddress: return "GlobalAddress";