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, 38 insertions, 18 deletions

diff --git a/llvm/lib/Target/PIC16/PIC16ISelLowering.h b/llvm/lib/Target/PIC16/PIC16ISelLowering.h
index 69cc27071d2..1f3c59aad0b 100644
--- a/llvm/lib/Target/PIC16/PIC16ISelLowering.h
+++ b/llvm/lib/Target/PIC16/PIC16ISelLowering.h
@@ -52,6 +52,7 @@ namespace llvm {
       SUBCC,         // Compare for equality or inequality.
       SELECT_ICC,    // Psuedo to be caught in schedular and expanded to brcond.
       BRCOND,        // Conditional branch.
+      RET,           // Return.
       Dummy
     };
 
@@ -82,32 +83,35 @@ namespace llvm {
     virtual const char *getTargetNodeName(unsigned Opcode) const;
     /// getSetCCResultType - Return the ISD::SETCC ValueType
     virtual MVT getSetCCResultType(MVT ValType) const;
-    SDValue LowerFORMAL_ARGUMENTS(SDValue Op, SelectionDAG &DAG);
     SDValue LowerShift(SDValue Op, SelectionDAG &DAG);
     SDValue LowerMUL(SDValue Op, SelectionDAG &DAG);
     SDValue LowerADD(SDValue Op, SelectionDAG &DAG);
     SDValue LowerSUB(SDValue Op, SelectionDAG &DAG);
     SDValue LowerBinOp(SDValue Op, SelectionDAG &DAG);
-    SDValue LowerCALL(SDValue Op, SelectionDAG &DAG);
-    SDValue LowerRET(SDValue Op, SelectionDAG &DAG);
     // Call returns
     SDValue 
-    LowerDirectCallReturn(SDValue Op, SDValue Chain, SDValue FrameAddress, 
-                          SDValue InFlag, SelectionDAG &DAG);
+    LowerDirectCallReturn(SDValue RetLabel, SDValue Chain, SDValue InFlag,
+                          const SmallVectorImpl<ISD::InputArg> &Ins,
+                          DebugLoc dl, SelectionDAG &DAG,
+                          SmallVectorImpl<SDValue> &InVals);
     SDValue 
-    LowerIndirectCallReturn(SDValue Op, SDValue Chain, SDValue InFlag,
-                            SDValue DataAddr_Lo, SDValue DataAddr_Hi,
-                            SelectionDAG &DAG);
+    LowerIndirectCallReturn(SDValue Chain, SDValue InFlag,
+                             SDValue DataAddr_Lo, SDValue DataAddr_Hi,
+                            const SmallVectorImpl<ISD::InputArg> &Ins,
+                            DebugLoc dl, SelectionDAG &DAG,
+                            SmallVectorImpl<SDValue> &InVals);
 
     // Call arguments
     SDValue 
-    LowerDirectCallArguments(SDValue Op, SDValue Chain, SDValue FrameAddress, 
-                             SDValue InFlag, SelectionDAG &DAG);
+    LowerDirectCallArguments(SDValue ArgLabel, SDValue Chain, SDValue InFlag,
+                             const SmallVectorImpl<ISD::OutputArg> &Outs,
+                             DebugLoc dl, SelectionDAG &DAG);
 
     SDValue 
-    LowerIndirectCallArguments(SDValue Op, SDValue Chain, SDValue InFlag, 
+    LowerIndirectCallArguments(SDValue Chain, SDValue InFlag,
                                SDValue DataAddr_Lo, SDValue DataAddr_Hi, 
-                               SelectionDAG &DAG);
+                               const SmallVectorImpl<ISD::OutputArg> &Outs,
+                               DebugLoc dl, SelectionDAG &DAG);
 
     SDValue LowerBR_CC(SDValue Op, SelectionDAG &DAG);
     SDValue LowerSELECT_CC(SDValue Op, SelectionDAG &DAG);
@@ -125,6 +129,28 @@ namespace llvm {
                                        SmallVectorImpl<SDValue> &Results,
                                        SelectionDAG &DAG);
 
+    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);
+
     SDValue ExpandStore(SDNode *N, SelectionDAG &DAG);
     SDValue ExpandLoad(SDNode *N, SelectionDAG &DAG);
     SDValue ExpandGlobalAddress(SDNode *N, SelectionDAG &DAG);
@@ -175,12 +201,6 @@ namespace llvm {
     void LegalizeFrameIndex(SDValue Op, SelectionDAG &DAG, SDValue &ES, 
                             int &Offset);
 
-
-    // CALL node should have all legal operands only. Legalize all non-legal
-    // operands of CALL node and then return the new call will all operands
-    // legal.
-    SDValue LegalizeCALL(SDValue Op, SelectionDAG &DAG);
-
     // For indirect calls data address of the callee frame need to be
     // extracted. This function fills the arguments DataAddr_Lo and 
     // DataAddr_Hi with the address of the callee frame.