Define CallSDNode, an SDNode subclass for use with ISD::CALL.

Currently it just holds the calling convention and flags
for isVarArgs and isTailCall.

And it has several utility methods, which eliminate magic
5+2*i and similar index computations in several places.

CallSDNodes are not CSE'd. Teach UpdateNodeOperands to handle
nodes that are not CSE'd gracefully.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@56183 91177308-0d34-0410-b5e6-96231b3b80d8

4 files changed, 64 insertions, 11 deletions

diff --git a/include/llvm/CodeGen/CallingConvLower.h b/include/llvm/CodeGen/CallingConvLower.h
index 6773c49..2a57cc1 100644
--- a/include/llvm/CodeGen/CallingConvLower.h
+++ b/include/llvm/CodeGen/CallingConvLower.h
@@ -143,7 +143,7 @@ public:
   
   /// AnalyzeCallOperands - Analyze an ISD::CALL node, incorporating info
   /// about the passed values into this state.
-  void AnalyzeCallOperands(SDNode *TheCall, CCAssignFn Fn);
+  void AnalyzeCallOperands(CallSDNode *TheCall, CCAssignFn Fn);
 
   /// AnalyzeCallOperands - Same as above except it takes vectors of types
   /// and argument flags.
@@ -153,7 +153,7 @@ public:
 
   /// AnalyzeCallResult - Analyze the return values of an ISD::CALL node,
   /// incorporating info about the passed values into this state.
-  void AnalyzeCallResult(SDNode *TheCall, CCAssignFn Fn);
+  void AnalyzeCallResult(CallSDNode *TheCall, CCAssignFn Fn);
   
   /// AnalyzeCallResult - Same as above except it's specialized for calls which
   /// produce a single value.
diff --git a/include/llvm/CodeGen/SelectionDAG.h b/include/llvm/CodeGen/SelectionDAG.h
index 52c67c0..15d0edc 100644
--- a/include/llvm/CodeGen/SelectionDAG.h
+++ b/include/llvm/CodeGen/SelectionDAG.h
@@ -463,6 +463,11 @@ public:
     return getNode(ISD::MERGE_VALUES, VTs, Ops, NumOps);
   }
 
+  /// getCall - Create a CALL node from the given information.
+  ///
+  SDValue getCall(unsigned CallingConv, bool IsVarArgs, bool IsTailCall,
+                  SDVTList VTs, const SDValue *Operands, unsigned NumOperands);
+
   /// getLoad - Loads are not normal binary operators: their result type is not
   /// determined by their operands, and they produce a value AND a token chain.
   ///
@@ -731,7 +736,7 @@ public:
   SDValue getShuffleScalarElt(const SDNode *N, unsigned Idx);
   
 private:
-  void RemoveNodeFromCSEMaps(SDNode *N);
+  bool RemoveNodeFromCSEMaps(SDNode *N);
   SDNode *AddNonLeafNodeToCSEMaps(SDNode *N);
   SDNode *FindModifiedNodeSlot(SDNode *N, SDValue Op, void *&InsertPos);
   SDNode *FindModifiedNodeSlot(SDNode *N, SDValue Op1, SDValue Op2,
diff --git a/include/llvm/CodeGen/SelectionDAGNodes.h b/include/llvm/CodeGen/SelectionDAGNodes.h
index 7d6a177..85c4649 100644
--- a/include/llvm/CodeGen/SelectionDAGNodes.h
+++ b/include/llvm/CodeGen/SelectionDAGNodes.h
@@ -179,7 +179,7 @@ namespace ISD {
     /// 
     FORMAL_ARGUMENTS,
     
-    /// RV1, RV2...RVn, CHAIN = CALL(CHAIN, CC#, ISVARARG, ISTAILCALL, CALLEE,
+    /// RV1, RV2...RVn, CHAIN = CALL(CHAIN, CALLEE,
     ///                              ARG0, FLAG0, ARG1, FLAG1, ... ARGn, FLAGn)
     /// This node represents a fully general function call, before the legalizer
     /// runs.  This has one result value for each argument / flag pair, plus
@@ -194,6 +194,11 @@ namespace ISD {
     /// Bit 10-26 - size of byval structures
     /// Bits 31:27 - argument ABI alignment in the first argument piece and
     /// alignment '1' in other argument pieces.
+    ///
+    /// CALL nodes use the CallSDNode subclass of SDNode, which
+    /// additionally carries information about the calling convention,
+    /// whether the call is varargs, and if it's marked as a tail call.
+    ///
     CALL,
 
     // EXTRACT_ELEMENT - This is used to get the lower or upper (determined by
@@ -2181,6 +2186,49 @@ public:
   }
 };
 
+/// CallSDNode - Node for calls -- ISD::CALL.
+class CallSDNode : public SDNode {
+  unsigned CallingConv;
+  bool IsVarArg;
+  bool IsTailCall;
+  virtual void ANCHOR();  // Out-of-line virtual method to give class a home.
+protected:
+  friend class SelectionDAG;
+  CallSDNode(unsigned cc, bool isvararg, bool istailcall,
+             SDVTList VTs, const SDValue *Operands, unsigned numOperands)
+    : SDNode(ISD::CALL, VTs, Operands, numOperands),
+      CallingConv(cc), IsVarArg(isvararg), IsTailCall(istailcall) {}
+public:
+  unsigned getCallingConv() const { return CallingConv; }
+  unsigned isVarArg() const { return IsVarArg; }
+  unsigned isTailCall() const { return IsTailCall; }
+
+  /// Set this call to not be marked as a tail call. Normally setter
+  /// methods in SDNodes are unsafe because it breaks the CSE map,
+  /// but we don't CSE calls so it's ok in this case.
+  void setNotTailCall() { IsTailCall = false; }
+
+  SDValue getChain() const { return getOperand(0); }
+  SDValue getCallee() const { return getOperand(1); }
+
+  unsigned getNumArgs() const { return (getNumOperands() - 2) / 2; }
+  SDValue getArg(unsigned i) const { return getOperand(2+2*i); }
+  SDValue getArgFlagsVal(unsigned i) const {
+    return getOperand(3+2*i);
+  }
+  ISD::ArgFlagsTy getArgFlags(unsigned i) const {
+    return cast<ARG_FLAGSSDNode>(getArgFlagsVal(i).getNode())->getArgFlags();
+  }
+
+  unsigned getNumRetVals() const { return getNumValues() - 1; }
+  MVT getRetValType(unsigned i) const { return getValueType(i); }
+
+  static bool classof(const CallSDNode *) { return true; }
+  static bool classof(const SDNode *N) {
+    return N->getOpcode() == ISD::CALL;
+  }
+};
+
 /// VTSDNode - This class is used to represent MVT's, which are used
 /// to parameterize some operations.
 class VTSDNode : public SDNode {
diff --git a/include/llvm/Target/TargetLowering.h b/include/llvm/Target/TargetLowering.h
index 85279bb..af56416 100644
--- a/include/llvm/Target/TargetLowering.h
+++ b/include/llvm/Target/TargetLowering.h
@@ -1075,7 +1075,7 @@ public:
   /// IsEligibleForTailCallOptimization - Check whether the call is eligible for
   /// tail call optimization. Targets which want to do tail call optimization
   /// should override this function. 
-  virtual bool IsEligibleForTailCallOptimization(SDValue Call, 
+  virtual bool IsEligibleForTailCallOptimization(CallSDNode *Call, 
                                                  SDValue Ret, 
                                                  SelectionDAG &DAG) const {
     return false;
@@ -1085,15 +1085,15 @@ public:
   /// preceeds the RET node and whether the return uses the result of the node
   /// or is a void return. This function can be used by the target to determine
   /// eligiblity of tail call optimization.
-  static bool CheckTailCallReturnConstraints(SDValue Call, SDValue Ret) {
+  static bool CheckTailCallReturnConstraints(CallSDNode *TheCall, SDValue Ret) {
     unsigned NumOps = Ret.getNumOperands();
     if ((NumOps == 1 &&
-       (Ret.getOperand(0) == SDValue(Call.getNode(),1) ||
-        Ret.getOperand(0) == SDValue(Call.getNode(),0))) ||
+       (Ret.getOperand(0) == SDValue(TheCall,1) ||
+        Ret.getOperand(0) == SDValue(TheCall,0))) ||
       (NumOps > 1 &&
-       Ret.getOperand(0) == SDValue(Call.getNode(),
-                                    Call.getNode()->getNumValues()-1) &&
-       Ret.getOperand(1) == SDValue(Call.getNode(),0)))
+       Ret.getOperand(0) == SDValue(TheCall,
+                                    TheCall->getNumValues()-1) &&
+       Ret.getOperand(1) == SDValue(TheCall,0)))
       return true;
     return false;
   }