lib/Target/MSP430/MSP430ISelLowering.h

   1 //===-- MSP430ISelLowering.h - MSP430 DAG Lowering Interface ----*- C++ -*-===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8 //
   9 // This file defines the interfaces that MSP430 uses to lower LLVM code into a
  10 // selection DAG.
  11 //
  12 //===----------------------------------------------------------------------===//
  13
  14 #ifndef LLVM_LIB_TARGET_MSP430_MSP430ISELLOWERING_H
  15 #define LLVM_LIB_TARGET_MSP430_MSP430ISELLOWERING_H
  16
  17 #include "MSP430.h"
  18 #include "llvm/CodeGen/SelectionDAG.h"
  19 #include "llvm/CodeGen/TargetLowering.h"
  20
  21 namespace llvm {
  22   namespace MSP430ISD {
  23     enum NodeType : unsigned {
  24       FIRST_NUMBER = ISD::BUILTIN_OP_END,
  25
  26       /// Return with a flag operand. Operand 0 is the chain operand.
  27       RET_FLAG,
  28
  29       /// Same as RET_FLAG, but used for returning from ISRs.
  30       RETI_FLAG,
  31
  32       /// Y = R{R,L}A X, rotate right (left) arithmetically
  33       RRA, RLA,
  34
  35       /// Y = RRC X, rotate right via carry
  36       RRC,
  37
  38       /// Rotate right via carry, carry gets cleared beforehand by clrc
  39       RRCL,
  40
  41       /// CALL - These operations represent an abstract call
  42       /// instruction, which includes a bunch of information.
  43       CALL,
  44
  45       /// Wrapper - A wrapper node for TargetConstantPool, TargetExternalSymbol,
  46       /// and TargetGlobalAddress.
  47       Wrapper,
  48
  49       /// CMP - Compare instruction.
  50       CMP,
  51
  52       /// SetCC - Operand 0 is condition code, and operand 1 is the flag
  53       /// operand produced by a CMP instruction.
  54       SETCC,
  55
  56       /// MSP430 conditional branches. Operand 0 is the chain operand, operand 1
  57       /// is the block to branch if condition is true, operand 2 is the
  58       /// condition code, and operand 3 is the flag operand produced by a CMP
  59       /// instruction.
  60       BR_CC,
  61
  62       /// SELECT_CC - Operand 0 and operand 1 are selection variable, operand 3
  63       /// is condition code and operand 4 is flag operand.
  64       SELECT_CC,
  65
  66       /// DADD - Decimal addition with carry
  67       /// TODO Nothing generates a node of this type yet.
  68       DADD,
  69     };
  70   }
  71
  72   class MSP430Subtarget;
  73   class MSP430TargetLowering : public TargetLowering {
  74   public:
  75     explicit MSP430TargetLowering(const TargetMachine &TM,
  76                                   const MSP430Subtarget &STI);
  77
  78     MVT getScalarShiftAmountTy(const DataLayout &, EVT) const override {
  79       return MVT::i8;
  80     }
  81
  82     /// LowerOperation - Provide custom lowering hooks for some operations.
  83     SDValue LowerOperation(SDValue Op, SelectionDAG &DAG) const override;
  84
  85     /// getTargetNodeName - This method returns the name of a target specific
  86     /// DAG node.
  87     const char *getTargetNodeName(unsigned Opcode) const override;
  88
  89     SDValue LowerShifts(SDValue Op, SelectionDAG &DAG) const;
  90     SDValue LowerGlobalAddress(SDValue Op, SelectionDAG &DAG) const;
  91     SDValue LowerBlockAddress(SDValue Op, SelectionDAG &DAG) const;
  92     SDValue LowerExternalSymbol(SDValue Op, SelectionDAG &DAG) const;
  93     SDValue LowerBR_CC(SDValue Op, SelectionDAG &DAG) const;
  94     SDValue LowerSETCC(SDValue Op, SelectionDAG &DAG) const;
  95     SDValue LowerSELECT_CC(SDValue Op, SelectionDAG &DAG) const;
  96     SDValue LowerSIGN_EXTEND(SDValue Op, SelectionDAG &DAG) const;
  97     SDValue LowerRETURNADDR(SDValue Op, SelectionDAG &DAG) const;
  98     SDValue LowerFRAMEADDR(SDValue Op, SelectionDAG &DAG) const;
  99     SDValue LowerVASTART(SDValue Op, SelectionDAG &DAG) const;
 100     SDValue LowerJumpTable(SDValue Op, SelectionDAG &DAG) const;
 101     SDValue getReturnAddressFrameIndex(SelectionDAG &DAG) const;
 102
 103     TargetLowering::ConstraintType
 104     getConstraintType(StringRef Constraint) const override;
 105     std::pair<unsigned, const TargetRegisterClass *>
 106     getRegForInlineAsmConstraint(const TargetRegisterInfo *TRI,
 107                                  StringRef Constraint, MVT VT) const override;
 108
 109     /// isTruncateFree - Return true if it's free to truncate a value of type
 110     /// Ty1 to type Ty2. e.g. On msp430 it's free to truncate a i16 value in
 111     /// register R15W to i8 by referencing its sub-register R15B.
 112     bool isTruncateFree(Type *Ty1, Type *Ty2) const override;
 113     bool isTruncateFree(EVT VT1, EVT VT2) const override;
 114
 115     /// isZExtFree - Return true if any actual instruction that defines a value
 116     /// of type Ty1 implicit zero-extends the value to Ty2 in the result
 117     /// register. This does not necessarily include registers defined in unknown
 118     /// ways, such as incoming arguments, or copies from unknown virtual
 119     /// registers. Also, if isTruncateFree(Ty2, Ty1) is true, this does not
 120     /// necessarily apply to truncate instructions. e.g. on msp430, all
 121     /// instructions that define 8-bit values implicit zero-extend the result
 122     /// out to 16 bits.
 123     bool isZExtFree(Type *Ty1, Type *Ty2) const override;
 124     bool isZExtFree(EVT VT1, EVT VT2) const override;
 125     bool isZExtFree(SDValue Val, EVT VT2) const override;
 126
 127     unsigned getShiftAmountThreshold(EVT VT) const override;
 128
 129     MachineBasicBlock *
 130     EmitInstrWithCustomInserter(MachineInstr &MI,
 131                                 MachineBasicBlock *BB) const override;
 132     MachineBasicBlock *EmitShiftInstr(MachineInstr &MI,
 133                                       MachineBasicBlock *BB) const;
 134
 135   private:
 136     SDValue LowerCCCCallTo(SDValue Chain, SDValue Callee,
 137                            CallingConv::ID CallConv, bool isVarArg,
 138                            bool isTailCall,
 139                            const SmallVectorImpl<ISD::OutputArg> &Outs,
 140                            const SmallVectorImpl<SDValue> &OutVals,
 141                            const SmallVectorImpl<ISD::InputArg> &Ins,
 142                            const SDLoc &dl, SelectionDAG &DAG,
 143                            SmallVectorImpl<SDValue> &InVals) const;
 144
 145     SDValue LowerCCCArguments(SDValue Chain, CallingConv::ID CallConv,
 146                               bool isVarArg,
 147                               const SmallVectorImpl<ISD::InputArg> &Ins,
 148                               const SDLoc &dl, SelectionDAG &DAG,
 149                               SmallVectorImpl<SDValue> &InVals) const;
 150
 151     SDValue LowerCallResult(SDValue Chain, SDValue InFlag,
 152                             CallingConv::ID CallConv, bool isVarArg,
 153                             const SmallVectorImpl<ISD::InputArg> &Ins,
 154                             const SDLoc &dl, SelectionDAG &DAG,
 155                             SmallVectorImpl<SDValue> &InVals) const;
 156
 157     SDValue
 158     LowerFormalArguments(SDValue Chain, CallingConv::ID CallConv, bool isVarArg,
 159                          const SmallVectorImpl<ISD::InputArg> &Ins,
 160                          const SDLoc &dl, SelectionDAG &DAG,
 161                          SmallVectorImpl<SDValue> &InVals) const override;
 162     SDValue
 163       LowerCall(TargetLowering::CallLoweringInfo &CLI,
 164                 SmallVectorImpl<SDValue> &InVals) const override;
 165
 166     bool CanLowerReturn(CallingConv::ID CallConv,
 167                         MachineFunction &MF,
 168                         bool IsVarArg,
 169                         const SmallVectorImpl<ISD::OutputArg> &Outs,
 170                         LLVMContext &Context) const override;
 171
 172     SDValue LowerReturn(SDValue Chain, CallingConv::ID CallConv, bool isVarArg,
 173                         const SmallVectorImpl<ISD::OutputArg> &Outs,
 174                         const SmallVectorImpl<SDValue> &OutVals,
 175                         const SDLoc &dl, SelectionDAG &DAG) const override;
 176
 177     bool getPostIndexedAddressParts(SDNode *N, SDNode *Op,
 178                                     SDValue &Base,
 179                                     SDValue &Offset,
 180                                     ISD::MemIndexedMode &AM,
 181                                     SelectionDAG &DAG) const override;
 182   };
 183 } // namespace llvm
 184
 185 #endif