Add new ImplicitDef node, rename CopyRegSDNode class to RegSDNode.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@19535 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/CodeGen/SelectionDAG.h

@@ -119,14 +119,21 @@ public:
   SDOperand getCopyToReg(SDOperand Chain, SDOperand N, unsigned Reg) {
     // Note: these are auto-CSE'd because the caller doesn't make requests that
     // could cause duplicates to occur.
-    SDNode *NN = new CopyRegSDNode(Chain, N, Reg);
+    SDNode *NN = new RegSDNode(Chain, N, Reg);
     AllNodes.push_back(NN);
     return SDOperand(NN, 0);
   }
 
   SDOperand getCopyFromReg(unsigned Reg, MVT::ValueType VT) {
     // Note: These nodes are auto-CSE'd by the caller of this method.
-    SDNode *NN = new CopyRegSDNode(Reg, VT);
+    SDNode *NN = new RegSDNode(ISD::CopyFromReg, Reg, VT);
+    AllNodes.push_back(NN);
+    return SDOperand(NN, 0);
+  }
+
+  SDOperand getImplicitDef(unsigned Reg) {
+    // Note: These nodes are auto-CSE'd by the caller of this method.
+    SDNode *NN = new RegSDNode(ISD::ImplicitDef, Reg, MVT::Other);
     AllNodes.push_back(NN);
     return SDOperand(NN, 0);
   }

include/llvm/CodeGen/SelectionDAGNodes.h

@@ -58,16 +58,22 @@ namespace ISD {
 
     // CopyToReg - This node has chain and child nodes, and an associated
     // register number.  The instruction selector must guarantee that the value
-    // of the value node is available in the register stored in the
-    // CopyRegSDNode object.
+    // of the value node is available in the register stored in the RegSDNode
+    // object.
     CopyToReg,
 
     // CopyFromReg - This node indicates that the input value is a virtual or
     // physical register that is defined outside of the scope of this
-    // SelectionDAG.  The register number is available from the CopyRegSDNode
-    // object.
+    // SelectionDAG.  The register is available from the RegSDNode object.
     CopyFromReg,
 
+    // ImplicitDef - This node indicates that the specified register is
+    // implicitly defined by some operation (e.g. its a live-in argument).  This
+    // register is indicated in the RegSDNode object.  The only operand to this
+    // is the token chain coming in, the only result is the token chain going
+    // out.
+    ImplicitDef,
+
     // EXTRACT_ELEMENT - This is used to get the first or second (determined by
     // a Constant, which is required to be operand #1), element of the aggregate
     // value specified as operand #0.  This is only for use before legalization,
@@ -608,25 +614,26 @@ public:
 };
 
 
-class CopyRegSDNode : public SDNode {
+class RegSDNode : public SDNode {
   unsigned Reg;
 protected:
   friend class SelectionDAG;
-  CopyRegSDNode(SDOperand Chain, SDOperand Src, unsigned reg)
+  RegSDNode(SDOperand Chain, SDOperand Src, unsigned reg)
     : SDNode(ISD::CopyToReg, Chain, Src), Reg(reg) {
     setValueTypes(MVT::Other);  // Just a token chain.
   }
-  CopyRegSDNode(unsigned reg, MVT::ValueType VT)
-    : SDNode(ISD::CopyFromReg, VT), Reg(reg) {
+  RegSDNode(unsigned Opc, unsigned reg, MVT::ValueType VT)
+    : SDNode(Opc, VT), Reg(reg) {
   }
 public:
 
   unsigned getReg() const { return Reg; }
 
-  static bool classof(const CopyRegSDNode *) { return true; }
+  static bool classof(const RegSDNode *) { return true; }
   static bool classof(const SDNode *N) {
     return N->getOpcode() == ISD::CopyToReg ||
-           N->getOpcode() == ISD::CopyFromReg;
+           N->getOpcode() == ISD::CopyFromReg ||
+           N->getOpcode() == ISD::ImplicitDef;
   }
 };
 

lib/CodeGen/SelectionDAG/LegalizeDAG.cpp

@@ -244,6 +244,11 @@ SDOperand SelectionDAGLegalize::LegalizeOp(SDOperand Op) {
     assert(getTypeAction(Node->getValueType(0)) == Legal &&
            "This must be legal!");
     break;
+  case ISD::ImplicitDef:
+    Tmp1 = LegalizeOp(Node->getOperand(0));
+    if (Tmp1 != Node->getOperand(0))
+      Result = DAG.getImplicitDef(cast<RegSDNode>(Node)->getReg());
+    break;
   case ISD::Constant:
     // We know we don't need to expand constants here, constants only have one
     // value and we check that it is fine above.
@@ -398,13 +403,12 @@ SDOperand SelectionDAGLegalize::LegalizeOp(SDOperand Op) {
       // Legalize the incoming value (must be legal).
       Tmp2 = LegalizeOp(Node->getOperand(1));
       if (Tmp1 != Node->getOperand(0) || Tmp2 != Node->getOperand(1))
-        Result = DAG.getCopyToReg(Tmp1, Tmp2,
-                                  cast<CopyRegSDNode>(Node)->getReg());
+        Result = DAG.getCopyToReg(Tmp1, Tmp2, cast<RegSDNode>(Node)->getReg());
       break;
     case Expand: {
       SDOperand Lo, Hi;
       ExpandOp(Node->getOperand(1), Lo, Hi);      
-      unsigned Reg = cast<CopyRegSDNode>(Node)->getReg();
+      unsigned Reg = cast<RegSDNode>(Node)->getReg();
       Result = DAG.getCopyToReg(Tmp1, Lo, Reg);
       Result = DAG.getCopyToReg(Result, Hi, Reg+1);
       assert(isTypeLegal(Result.getValueType()) &&
@@ -748,7 +752,7 @@ void SelectionDAGLegalize::ExpandOp(SDOperand Op, SDOperand &Lo, SDOperand &Hi){
   }
 
   case ISD::CopyFromReg: {
-    unsigned Reg = cast<CopyRegSDNode>(Node)->getReg();
+    unsigned Reg = cast<RegSDNode>(Node)->getReg();
     // Aggregate register values are always in consequtive pairs.
     Lo = DAG.getCopyFromReg(Reg, NVT);
     Hi = DAG.getCopyFromReg(Reg+1, NVT);

lib/CodeGen/SelectionDAG/SelectionDAG.cpp

@@ -880,6 +880,7 @@ const char *SDNode::getOperationName() const {
   case ISD::ConstantPool:  return "ConstantPoolIndex";
   case ISD::CopyToReg:     return "CopyToReg";
   case ISD::CopyFromReg:   return "CopyFromReg";
+  case ISD::ImplicitDef:   return "ImplicitDef";
 
   case ISD::ADD:    return "add";
   case ISD::SUB:    return "sub";
@@ -1006,7 +1007,7 @@ void SDNode::dump() const {
     if (LBB)
       std::cerr << LBB->getName() << " ";
     std::cerr << (const void*)BBDN->getBasicBlock() << ">";
-  } else if (const CopyRegSDNode *C2V = dyn_cast<CopyRegSDNode>(this)) {
+  } else if (const RegSDNode *C2V = dyn_cast<RegSDNode>(this)) {
     std::cerr << "<reg #" << C2V->getReg() << ">";
   } else if (const ExternalSymbolSDNode *ES =
              dyn_cast<ExternalSymbolSDNode>(this)) {

lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp

@@ -772,8 +772,9 @@ SDOperand SelectionDAGISel::
 CopyValueToVirtualRegister(SelectionDAGLowering &SDL, Value *V, unsigned Reg) {
   SelectionDAG &DAG = SDL.DAG;
   SDOperand Op = SDL.getValue(V);
-  if (CopyRegSDNode *CR = dyn_cast<CopyRegSDNode>(Op))
-    assert(CR->getReg() != Reg && "Copy from a reg to the same reg!");
+  assert((Op.getOpcode() != ISD::CopyFromReg ||
+          cast<RegSDNode>(Op)->getReg() != Reg) &&
+         "Copy from a reg to the same reg!");
   return DAG.getCopyToReg(DAG.getRoot(), Op, Reg);
 }
 

lib/CodeGen/SelectionDAG/SelectionDAGPrinter.cpp

@@ -85,7 +85,7 @@ std::string DOTGraphTraits<SelectionDAG*>::getNodeLabel(const SDNode *Node,
     if (LBB)
       Op += LBB->getName();
     //Op += " " + (const void*)BBDN->getBasicBlock();
-  } else if (const CopyRegSDNode *C2V = dyn_cast<CopyRegSDNode>(Node)) {
+  } else if (const RegSDNode *C2V = dyn_cast<RegSDNode>(Node)) {
     Op += " #" + utostr(C2V->getReg());
   } else if (const ExternalSymbolSDNode *ES =
              dyn_cast<ExternalSymbolSDNode>(Node)) {

lib/Target/X86/X86ISelPattern.cpp

@@ -1023,7 +1023,7 @@ unsigned ISel::SelectExpr(SDOperand N) {
 
   if (Node->getOpcode() == ISD::CopyFromReg)
     // Just use the specified register as our input.
-    return dyn_cast<CopyRegSDNode>(Node)->getReg();
+    return dyn_cast<RegSDNode>(Node)->getReg();
   
   unsigned &Reg = ExprMap[N];
   if (Reg) return Reg;
@@ -2111,7 +2111,7 @@ void ISel::Select(SDOperand N) {
       Tmp1 = SelectExpr(N.getOperand(1));
       Select(N.getOperand(0));
     }
-    Tmp2 = cast<CopyRegSDNode>(N)->getReg();
+    Tmp2 = cast<RegSDNode>(N)->getReg();
     
     if (Tmp1 != Tmp2) {
       switch (N.getOperand(1).getValueType()) {