xref: /freebsd/contrib/llvm-project/llvm/lib/Target/AVR/AVRISelLowering.h (revision a7dea1671b87c07d2d266f836bfa8b58efc7c134)
1 //===-- AVRISelLowering.h - AVR 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 AVR uses to lower LLVM code into a
10 // selection DAG.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #ifndef LLVM_AVR_ISEL_LOWERING_H
15 #define LLVM_AVR_ISEL_LOWERING_H
16 
17 #include "llvm/CodeGen/CallingConvLower.h"
18 #include "llvm/CodeGen/TargetLowering.h"
19 
20 namespace llvm {
21 
22 namespace AVRISD {
23 
24 /// AVR Specific DAG Nodes
25 enum NodeType {
26   /// Start the numbering where the builtin ops leave off.
27   FIRST_NUMBER = ISD::BUILTIN_OP_END,
28   /// Return from subroutine.
29   RET_FLAG,
30   /// Return from ISR.
31   RETI_FLAG,
32   /// Represents an abstract call instruction,
33   /// which includes a bunch of information.
34   CALL,
35   /// A wrapper node for TargetConstantPool,
36   /// TargetExternalSymbol, and TargetGlobalAddress.
37   WRAPPER,
38   LSL,     ///< Logical shift left.
39   LSR,     ///< Logical shift right.
40   ASR,     ///< Arithmetic shift right.
41   ROR,     ///< Bit rotate right.
42   ROL,     ///< Bit rotate left.
43   LSLLOOP, ///< A loop of single logical shift left instructions.
44   LSRLOOP, ///< A loop of single logical shift right instructions.
45   ROLLOOP, ///< A loop of single left bit rotate instructions.
46   RORLOOP, ///< A loop of single right bit rotate instructions.
47   ASRLOOP, ///< A loop of single arithmetic shift right instructions.
48   /// AVR conditional branches. Operand 0 is the chain operand, operand 1
49   /// is the block to branch if condition is true, operand 2 is the
50   /// condition code, and operand 3 is the flag operand produced by a CMP
51   /// or TEST instruction.
52   BRCOND,
53   /// Compare instruction.
54   CMP,
55   /// Compare with carry instruction.
56   CMPC,
57   /// Test for zero or minus instruction.
58   TST,
59   /// Operand 0 and operand 1 are selection variable, operand 2
60   /// is condition code and operand 3 is flag operand.
61   SELECT_CC
62 };
63 
64 } // end of namespace AVRISD
65 
66 class AVRSubtarget;
67 class AVRTargetMachine;
68 
69 /// Performs target lowering for the AVR.
70 class AVRTargetLowering : public TargetLowering {
71 public:
72   explicit AVRTargetLowering(const AVRTargetMachine &TM,
73                              const AVRSubtarget &STI);
74 
75 public:
76   MVT getScalarShiftAmountTy(const DataLayout &, EVT LHSTy) const override {
77     return MVT::i8;
78   }
79 
80   MVT::SimpleValueType getCmpLibcallReturnType() const override {
81     return MVT::i8;
82   }
83 
84   const char *getTargetNodeName(unsigned Opcode) const override;
85 
86   SDValue LowerOperation(SDValue Op, SelectionDAG &DAG) const override;
87 
88   void ReplaceNodeResults(SDNode *N, SmallVectorImpl<SDValue> &Results,
89                           SelectionDAG &DAG) const override;
90 
91   bool isLegalAddressingMode(const DataLayout &DL, const AddrMode &AM, Type *Ty,
92                              unsigned AS,
93                              Instruction *I = nullptr) const override;
94 
95   bool getPreIndexedAddressParts(SDNode *N, SDValue &Base, SDValue &Offset,
96                                  ISD::MemIndexedMode &AM,
97                                  SelectionDAG &DAG) const override;
98 
99   bool getPostIndexedAddressParts(SDNode *N, SDNode *Op, SDValue &Base,
100                                   SDValue &Offset, ISD::MemIndexedMode &AM,
101                                   SelectionDAG &DAG) const override;
102 
103   bool isOffsetFoldingLegal(const GlobalAddressSDNode *GA) const override;
104 
105   EVT getSetCCResultType(const DataLayout &DL, LLVMContext &Context,
106                          EVT VT) const override;
107 
108   MachineBasicBlock *
109   EmitInstrWithCustomInserter(MachineInstr &MI,
110                               MachineBasicBlock *MBB) const override;
111 
112   ConstraintType getConstraintType(StringRef Constraint) const override;
113 
114   ConstraintWeight
115   getSingleConstraintMatchWeight(AsmOperandInfo &info,
116                                  const char *constraint) const override;
117 
118   std::pair<unsigned, const TargetRegisterClass *>
119   getRegForInlineAsmConstraint(const TargetRegisterInfo *TRI,
120                                StringRef Constraint, MVT VT) const override;
121 
122   unsigned getInlineAsmMemConstraint(StringRef ConstraintCode) const override;
123 
124   void LowerAsmOperandForConstraint(SDValue Op, std::string &Constraint,
125                                     std::vector<SDValue> &Ops,
126                                     SelectionDAG &DAG) const override;
127 
128   Register getRegisterByName(const char* RegName, EVT VT,
129                              const MachineFunction &MF) const override;
130 
131   bool shouldSplitFunctionArgumentsAsLittleEndian(const DataLayout &DL)
132     const override {
133     return false;
134   }
135 
136 private:
137   SDValue getAVRCmp(SDValue LHS, SDValue RHS, ISD::CondCode CC, SDValue &AVRcc,
138                     SelectionDAG &DAG, SDLoc dl) const;
139   SDValue LowerShifts(SDValue Op, SelectionDAG &DAG) const;
140   SDValue LowerDivRem(SDValue Op, SelectionDAG &DAG) const;
141   SDValue LowerGlobalAddress(SDValue Op, SelectionDAG &DAG) const;
142   SDValue LowerBlockAddress(SDValue Op, SelectionDAG &DAG) const;
143   SDValue LowerBR_CC(SDValue Op, SelectionDAG &DAG) const;
144   SDValue LowerINLINEASM(SDValue Op, SelectionDAG &DAG) const;
145   SDValue LowerSELECT_CC(SDValue Op, SelectionDAG &DAG) const;
146   SDValue LowerSETCC(SDValue Op, SelectionDAG &DAG) const;
147   SDValue LowerVASTART(SDValue Op, SelectionDAG &DAG) const;
148 
149   CCAssignFn *CCAssignFnForReturn(CallingConv::ID CC) const;
150 
151   bool CanLowerReturn(CallingConv::ID CallConv,
152                       MachineFunction &MF, bool isVarArg,
153                       const SmallVectorImpl<ISD::OutputArg> &Outs,
154                       LLVMContext &Context) const override;
155 
156   SDValue LowerReturn(SDValue Chain, CallingConv::ID CallConv, bool isVarArg,
157                       const SmallVectorImpl<ISD::OutputArg> &Outs,
158                       const SmallVectorImpl<SDValue> &OutVals, const SDLoc &dl,
159                       SelectionDAG &DAG) const override;
160   SDValue LowerFormalArguments(SDValue Chain, CallingConv::ID CallConv,
161                                bool isVarArg,
162                                const SmallVectorImpl<ISD::InputArg> &Ins,
163                                const SDLoc &dl, SelectionDAG &DAG,
164                                SmallVectorImpl<SDValue> &InVals) const override;
165   SDValue LowerCall(TargetLowering::CallLoweringInfo &CLI,
166                     SmallVectorImpl<SDValue> &InVals) const override;
167   SDValue LowerCallResult(SDValue Chain, SDValue InFlag,
168                           CallingConv::ID CallConv, bool isVarArg,
169                           const SmallVectorImpl<ISD::InputArg> &Ins,
170                           const SDLoc &dl, SelectionDAG &DAG,
171                           SmallVectorImpl<SDValue> &InVals) const;
172 
173 protected:
174 
175   const AVRSubtarget &Subtarget;
176 
177 private:
178   MachineBasicBlock *insertShift(MachineInstr &MI, MachineBasicBlock *BB) const;
179   MachineBasicBlock *insertMul(MachineInstr &MI, MachineBasicBlock *BB) const;
180 };
181 
182 } // end namespace llvm
183 
184 #endif // LLVM_AVR_ISEL_LOWERING_H
185