MSP430ISelLowering.h revision 968b667e27d7fc9a5bf5da52191a7af629e174dc 
1//===-- MSP430ISelLowering.h - MSP430 DAG Lowering Interface ----*- C++ -*-===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// This file defines the interfaces that MSP430 uses to lower LLVM code into a
11// selection DAG.
12//
13//===----------------------------------------------------------------------===//
14
15#ifndef LLVM_TARGET_MSP430_ISELLOWERING_H
16#define LLVM_TARGET_MSP430_ISELLOWERING_H
17
18#include "MSP430.h"
19#include "llvm/CodeGen/SelectionDAG.h"
20#include "llvm/Target/TargetLowering.h"
21
22namespace llvm {
23  namespace MSP430ISD {
24    enum {
25      FIRST_NUMBER = ISD::BUILTIN_OP_END,
26
27      /// Return with a flag operand. Operand 0 is the chain operand.
28      RET_FLAG,
29
30      /// Same as RET_FLAG, but used for returning from ISRs.
31      RETI_FLAG,
32
33      /// Y = R{R,L}A X, rotate right (left) arithmetically
34      RRA, RLA,
35
36      /// Y = RRC X, rotate right via carry
37      RRC,
38
39      /// CALL - These operations represent an abstract call
40      /// instruction, which includes a bunch of information.
41      CALL,
42
43      /// Wrapper - A wrapper node for TargetConstantPool, TargetExternalSymbol,
44      /// and TargetGlobalAddress.
45      Wrapper,
46
47      /// CMP - Compare instruction.
48      CMP,
49
50      /// SetCC - Operand 0 is condition code, and operand 1 is the flag
51      /// operand produced by a CMP instruction.
52      SETCC,
53
54      /// MSP430 conditional branches. Operand 0 is the chain operand, operand 1
55      /// is the block to branch if condition is true, operand 2 is the
56      /// condition code, and operand 3 is the flag operand produced by a CMP
57      /// instruction.
58      BR_CC,
59
60      /// SELECT_CC - Operand 0 and operand 1 are selection variable, operand 3
61      /// is condition code and operand 4 is flag operand.
62      SELECT_CC,
63
64      /// SHL, SRA, SRL - Non-constant shifts.
65      SHL, SRA, SRL
66    };
67  }
68
69  class MSP430Subtarget;
70  class MSP430TargetMachine;
71
72  class MSP430TargetLowering : public TargetLowering {
73  public:
74    explicit MSP430TargetLowering(MSP430TargetMachine &TM);
75
76    virtual MVT getShiftAmountTy(EVT LHSTy) const { return MVT::i8; }
77
78    /// LowerOperation - Provide custom lowering hooks for some operations.
79    virtual SDValue LowerOperation(SDValue Op, SelectionDAG &DAG) const;
80
81    /// getTargetNodeName - This method returns the name of a target specific
82    /// DAG node.
83    virtual const char *getTargetNodeName(unsigned Opcode) const;
84
85    SDValue LowerShifts(SDValue Op, SelectionDAG &DAG) const;
86    SDValue LowerGlobalAddress(SDValue Op, SelectionDAG &DAG) const;
87    SDValue LowerBlockAddress(SDValue Op, SelectionDAG &DAG) const;
88    SDValue LowerExternalSymbol(SDValue Op, SelectionDAG &DAG) const;
89    SDValue LowerBR_CC(SDValue Op, SelectionDAG &DAG) const;
90    SDValue LowerSETCC(SDValue Op, SelectionDAG &DAG) const;
91    SDValue LowerSELECT_CC(SDValue Op, SelectionDAG &DAG) const;
92    SDValue LowerSIGN_EXTEND(SDValue Op, SelectionDAG &DAG) const;
93    SDValue LowerRETURNADDR(SDValue Op, SelectionDAG &DAG) const;
94    SDValue LowerFRAMEADDR(SDValue Op, SelectionDAG &DAG) const;
95    SDValue LowerVASTART(SDValue Op, SelectionDAG &DAG) const;
96    SDValue getReturnAddressFrameIndex(SelectionDAG &DAG) const;
97
98    TargetLowering::ConstraintType
99    getConstraintType(const std::string &Constraint) const;
100    std::pair<unsigned, const TargetRegisterClass*>
101    getRegForInlineAsmConstraint(const std::string &Constraint, EVT VT) const;
102
103    /// isTruncateFree - Return true if it's free to truncate a value of type
104    /// Ty1 to type Ty2. e.g. On msp430 it's free to truncate a i16 value in
105    /// register R15W to i8 by referencing its sub-register R15B.
106    virtual bool isTruncateFree(Type *Ty1, Type *Ty2) const;
107    virtual bool isTruncateFree(EVT VT1, EVT VT2) const;
108
109    /// isZExtFree - Return true if any actual instruction that defines a value
110    /// of type Ty1 implicit zero-extends the value to Ty2 in the result
111    /// register. This does not necessarily include registers defined in unknown
112    /// ways, such as incoming arguments, or copies from unknown virtual
113    /// registers. Also, if isTruncateFree(Ty2, Ty1) is true, this does not
114    /// necessarily apply to truncate instructions. e.g. on msp430, all
115    /// instructions that define 8-bit values implicit zero-extend the result
116    /// out to 16 bits.
117    virtual bool isZExtFree(Type *Ty1, Type *Ty2) const;
118    virtual bool isZExtFree(EVT VT1, EVT VT2) const;
119    virtual bool isZExtFree(SDValue Val, EVT VT2) const;
120
121    MachineBasicBlock* EmitInstrWithCustomInserter(MachineInstr *MI,
122                                                   MachineBasicBlock *BB) const;
123    MachineBasicBlock* EmitShiftInstr(MachineInstr *MI,
124                                      MachineBasicBlock *BB) const;
125
126  private:
127    SDValue LowerCCCCallTo(SDValue Chain, SDValue Callee,
128                           CallingConv::ID CallConv, bool isVarArg,
129                           bool isTailCall,
130                           const SmallVectorImpl<ISD::OutputArg> &Outs,
131                           const SmallVectorImpl<SDValue> &OutVals,
132                           const SmallVectorImpl<ISD::InputArg> &Ins,
133                           DebugLoc dl, SelectionDAG &DAG,
134                           SmallVectorImpl<SDValue> &InVals) const;
135
136    SDValue LowerCCCArguments(SDValue Chain,
137                              CallingConv::ID CallConv,
138                              bool isVarArg,
139                              const SmallVectorImpl<ISD::InputArg> &Ins,
140                              DebugLoc dl,
141                              SelectionDAG &DAG,
142                              SmallVectorImpl<SDValue> &InVals) const;
143
144    SDValue LowerCallResult(SDValue Chain, SDValue InFlag,
145                            CallingConv::ID CallConv, bool isVarArg,
146                            const SmallVectorImpl<ISD::InputArg> &Ins,
147                            DebugLoc dl, SelectionDAG &DAG,
148                            SmallVectorImpl<SDValue> &InVals) const;
149
150    virtual SDValue
151      LowerFormalArguments(SDValue Chain,
152                           CallingConv::ID CallConv, bool isVarArg,
153                           const SmallVectorImpl<ISD::InputArg> &Ins,
154                           DebugLoc dl, SelectionDAG &DAG,
155                           SmallVectorImpl<SDValue> &InVals) const;
156    virtual SDValue
157      LowerCall(TargetLowering::CallLoweringInfo &CLI,
158                SmallVectorImpl<SDValue> &InVals) const;
159
160    virtual SDValue
161      LowerReturn(SDValue Chain,
162                  CallingConv::ID CallConv, bool isVarArg,
163                  const SmallVectorImpl<ISD::OutputArg> &Outs,
164                  const SmallVectorImpl<SDValue> &OutVals,
165                  DebugLoc dl, SelectionDAG &DAG) const;
166
167    virtual bool getPostIndexedAddressParts(SDNode *N, SDNode *Op,
168                                            SDValue &Base,
169                                            SDValue &Offset,
170                                            ISD::MemIndexedMode &AM,
171                                            SelectionDAG &DAG) const;
172
173    const MSP430Subtarget &Subtarget;
174    const DataLayout *TD;
175  };
176} // namespace llvm
177
178#endif // LLVM_TARGET_MSP430_ISELLOWERING_H
179