Major calling convention code refactoring.

Instead of awkwardly encoding calling-convention information with ISD::CALL,
ISD::FORMAL_ARGUMENTS, ISD::RET, and ISD::ARG_FLAGS nodes, TargetLowering
provides three virtual functions for targets to override:
LowerFormalArguments, LowerCall, and LowerRet, which replace the custom
lowering done on the special nodes. They provide the same information, but
in a more immediately usable format.

This also reworks much of the target-independent tail call logic. The
decision of whether or not to perform a tail call is now cleanly split
between target-independent portions, and the target dependent portion
in IsEligibleForTailCallOptimization.

This also synchronizes all in-tree targets, to help enable future
refactoring and feature work.

llvm-svn: 78142

1 files changed, 43 insertions, 11 deletions

diff --git a/llvm/lib/Target/MSP430/MSP430ISelLowering.h b/llvm/lib/Target/MSP430/MSP430ISelLowering.h
index 4a90a0eb263..1339ccda079 100644
--- a/llvm/lib/Target/MSP430/MSP430ISelLowering.h
+++ b/llvm/lib/Target/MSP430/MSP430ISelLowering.h
@@ -33,7 +33,7 @@ namespace llvm {
       /// Y = RRC X, rotate right via carry
       RRC,
 
-      /// CALL/TAILCALL - These operations represent an abstract call
+      /// CALL - These operations represent an abstract call
       /// instruction, which includes a bunch of information.
       CALL,
 
@@ -77,10 +77,6 @@ namespace llvm {
     /// getFunctionAlignment - Return the Log2 alignment of this function.
     virtual unsigned getFunctionAlignment(const Function *F) const;
 
-    SDValue LowerFORMAL_ARGUMENTS(SDValue Op, SelectionDAG &DAG);
-    SDValue LowerCALL(SDValue Op, SelectionDAG &DAG);
-    SDValue LowerRET(SDValue Op, SelectionDAG &DAG);
-    SDValue LowerCCCArguments(SDValue Op, SelectionDAG &DAG);
     SDValue LowerShifts(SDValue Op, SelectionDAG &DAG);
     SDValue LowerGlobalAddress(SDValue Op, SelectionDAG &DAG);
     SDValue LowerExternalSymbol(SDValue Op, SelectionDAG &DAG);
@@ -88,16 +84,52 @@ namespace llvm {
     SDValue LowerSELECT_CC(SDValue Op, SelectionDAG &DAG);
     SDValue LowerSIGN_EXTEND(SDValue Op, SelectionDAG &DAG);
 
-    SDValue LowerCCCCallTo(SDValue Op, SelectionDAG &DAG,
-                           unsigned CC);
-    SDNode* LowerCallResult(SDValue Chain, SDValue InFlag,
-                            CallSDNode *TheCall,
-                            unsigned CallingConv, SelectionDAG &DAG);
-
     MachineBasicBlock* EmitInstrWithCustomInserter(MachineInstr *MI,
                                                    MachineBasicBlock *BB) const;
 
   private:
+    SDValue LowerCCCCallTo(SDValue Chain, SDValue Callee,
+                           unsigned CallConv, bool isVarArg,
+                           bool isTailCall,
+                           const SmallVectorImpl<ISD::OutputArg> &Outs,
+                           const SmallVectorImpl<ISD::InputArg> &Ins,
+                           DebugLoc dl, SelectionDAG &DAG,
+                           SmallVectorImpl<SDValue> &InVals);
+
+    SDValue LowerCCCArguments(SDValue Chain,
+                              unsigned CallConv,
+                              bool isVarArg,
+                              const SmallVectorImpl<ISD::InputArg> &Ins,
+                              DebugLoc dl,
+                              SelectionDAG &DAG,
+                              SmallVectorImpl<SDValue> &InVals);
+
+    SDValue LowerCallResult(SDValue Chain, SDValue InFlag,
+                            unsigned CallConv, bool isVarArg,
+                            const SmallVectorImpl<ISD::InputArg> &Ins,
+                            DebugLoc dl, SelectionDAG &DAG,
+                            SmallVectorImpl<SDValue> &InVals);
+
+    virtual SDValue
+      LowerFormalArguments(SDValue Chain,
+                           unsigned CallConv, bool isVarArg,
+                           const SmallVectorImpl<ISD::InputArg> &Ins,
+                           DebugLoc dl, SelectionDAG &DAG,
+                           SmallVectorImpl<SDValue> &InVals);
+    virtual SDValue
+      LowerCall(SDValue Chain, SDValue Callee,
+                unsigned CallConv, bool isVarArg, bool isTailCall,
+                const SmallVectorImpl<ISD::OutputArg> &Outs,
+                const SmallVectorImpl<ISD::InputArg> &Ins,
+                DebugLoc dl, SelectionDAG &DAG,
+                SmallVectorImpl<SDValue> &InVals);
+
+    virtual SDValue
+      LowerReturn(SDValue Chain,
+                  unsigned CallConv, bool isVarArg,
+                  const SmallVectorImpl<ISD::OutputArg> &Outs,
+                  DebugLoc dl, SelectionDAG &DAG);
+
     const MSP430Subtarget &Subtarget;
     const MSP430TargetMachine &TM;
   };