1 //===-- XCoreISelLowering.h - XCore 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 XCore uses to lower LLVM code into a
11 // selection DAG.
12 //
13 //===----------------------------------------------------------------------===//
14 
15 #ifndef LLVM_LIB_TARGET_XCORE_XCOREISELLOWERING_H
16 #define LLVM_LIB_TARGET_XCORE_XCOREISELLOWERING_H
17 
18 #include "XCore.h"
19 #include "llvm/CodeGen/SelectionDAG.h"
20 #include "llvm/Target/TargetLowering.h"
21 
22 namespace llvm {
23 
24   // Forward delcarations
25   class XCoreSubtarget;
26   class XCoreTargetMachine;
27 
28   namespace XCoreISD {
29     enum NodeType {
30       // Start the numbering where the builtin ops and target ops leave off.
31       FIRST_NUMBER = ISD::BUILTIN_OP_END,
32 
33       // Branch and link (call)
34       BL,
35 
36       // pc relative address
37       PCRelativeWrapper,
38 
39       // dp relative address
40       DPRelativeWrapper,
41 
42       // cp relative address
43       CPRelativeWrapper,
44 
45       // Load word from stack
46       LDWSP,
47 
48       // Store word to stack
49       STWSP,
50 
51       // Corresponds to retsp instruction
52       RETSP,
53 
54       // Corresponds to LADD instruction
55       LADD,
56 
57       // Corresponds to LSUB instruction
58       LSUB,
59 
60       // Corresponds to LMUL instruction
61       LMUL,
62 
63       // Corresponds to MACCU instruction
64       MACCU,
65 
66       // Corresponds to MACCS instruction
67       MACCS,
68 
69       // Corresponds to CRC8 instruction
70       CRC8,
71 
72       // Jumptable branch.
73       BR_JT,
74 
75       // Jumptable branch using long branches for each entry.
76       BR_JT32,
77 
78       // Offset from frame pointer to the first (possible) on-stack argument
79       FRAME_TO_ARGS_OFFSET,
80 
81       // Exception handler return. The stack is restored to the first
82       // followed by a jump to the second argument.
83       EH_RETURN,
84 
85       // Memory barrier.
86       MEMBARRIER
87     };
88   }
89 
90   //===--------------------------------------------------------------------===//
91   // TargetLowering Implementation
92   //===--------------------------------------------------------------------===//
93   class XCoreTargetLowering : public TargetLowering
94   {
95   public:
96     explicit XCoreTargetLowering(const TargetMachine &TM,
97                                  const XCoreSubtarget &Subtarget);
98 
99     using TargetLowering::isZExtFree;
100     bool isZExtFree(SDValue Val, EVT VT2) const override;
101 
102 
103     unsigned getJumpTableEncoding() const override;
getScalarShiftAmountTy(EVT LHSTy)104     MVT getScalarShiftAmountTy(EVT LHSTy) const override { return MVT::i32; }
105 
106     /// LowerOperation - Provide custom lowering hooks for some operations.
107     SDValue LowerOperation(SDValue Op, SelectionDAG &DAG) const override;
108 
109     /// ReplaceNodeResults - Replace the results of node with an illegal result
110     /// type with new values built out of custom code.
111     ///
112     void ReplaceNodeResults(SDNode *N, SmallVectorImpl<SDValue>&Results,
113                             SelectionDAG &DAG) const override;
114 
115     /// getTargetNodeName - This method returns the name of a target specific
116     //  DAG node.
117     const char *getTargetNodeName(unsigned Opcode) const override;
118 
119     MachineBasicBlock *
120       EmitInstrWithCustomInserter(MachineInstr *MI,
121                                   MachineBasicBlock *MBB) const override;
122 
123     bool isLegalAddressingMode(const AddrMode &AM, Type *Ty) const override;
124 
125   private:
126     const TargetMachine &TM;
127     const XCoreSubtarget &Subtarget;
128 
129     // Lower Operand helpers
130     SDValue LowerCCCArguments(SDValue Chain,
131                               CallingConv::ID CallConv,
132                               bool isVarArg,
133                               const SmallVectorImpl<ISD::InputArg> &Ins,
134                               SDLoc dl, SelectionDAG &DAG,
135                               SmallVectorImpl<SDValue> &InVals) const;
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                            SDLoc dl, SelectionDAG &DAG,
143                            SmallVectorImpl<SDValue> &InVals) const;
144     SDValue getReturnAddressFrameIndex(SelectionDAG &DAG) const;
145     SDValue getGlobalAddressWrapper(SDValue GA, const GlobalValue *GV,
146                                     SelectionDAG &DAG) const;
147     SDValue lowerLoadWordFromAlignedBasePlusOffset(SDLoc DL, SDValue Chain,
148                                                    SDValue Base, int64_t Offset,
149                                                    SelectionDAG &DAG) const;
150 
151     // Lower Operand specifics
152     SDValue LowerLOAD(SDValue Op, SelectionDAG &DAG) const;
153     SDValue LowerSTORE(SDValue Op, SelectionDAG &DAG) const;
154     SDValue LowerEH_RETURN(SDValue Op, SelectionDAG &DAG) const;
155     SDValue LowerGlobalAddress(SDValue Op, SelectionDAG &DAG) const;
156     SDValue LowerGlobalTLSAddress(SDValue Op, SelectionDAG &DAG) const;
157     SDValue LowerBlockAddress(SDValue Op, SelectionDAG &DAG) const;
158     SDValue LowerConstantPool(SDValue Op, SelectionDAG &DAG) const;
159     SDValue LowerBR_JT(SDValue Op, SelectionDAG &DAG) const;
160     SDValue LowerVAARG(SDValue Op, SelectionDAG &DAG) const;
161     SDValue LowerVASTART(SDValue Op, SelectionDAG &DAG) const;
162     SDValue LowerUMUL_LOHI(SDValue Op, SelectionDAG &DAG) const;
163     SDValue LowerSMUL_LOHI(SDValue Op, SelectionDAG &DAG) const;
164     SDValue LowerFRAMEADDR(SDValue Op, SelectionDAG &DAG) const;
165     SDValue LowerFRAME_TO_ARGS_OFFSET(SDValue Op, SelectionDAG &DAG) const;
166     SDValue LowerRETURNADDR(SDValue Op, SelectionDAG &DAG) const;
167     SDValue LowerINIT_TRAMPOLINE(SDValue Op, SelectionDAG &DAG) const;
168     SDValue LowerADJUST_TRAMPOLINE(SDValue Op, SelectionDAG &DAG) const;
169     SDValue LowerINTRINSIC_WO_CHAIN(SDValue Op, SelectionDAG &DAG) const;
170     SDValue LowerATOMIC_FENCE(SDValue Op, SelectionDAG &DAG) const;
171     SDValue LowerATOMIC_LOAD(SDValue Op, SelectionDAG &DAG) const;
172     SDValue LowerATOMIC_STORE(SDValue Op, SelectionDAG &DAG) const;
173 
174     // Inline asm support
175     std::pair<unsigned, const TargetRegisterClass *>
176     getRegForInlineAsmConstraint(const TargetRegisterInfo *TRI,
177                                  const std::string &Constraint,
178                                  MVT VT) const override;
179 
getInlineAsmMemConstraint(const std::string & ConstraintCode)180     unsigned getInlineAsmMemConstraint(
181         const std::string &ConstraintCode) const override {
182       // FIXME: Map different constraints differently.
183       return InlineAsm::Constraint_m;
184     }
185 
186     // Expand specifics
187     SDValue TryExpandADDWithMul(SDNode *Op, SelectionDAG &DAG) const;
188     SDValue ExpandADDSUB(SDNode *Op, SelectionDAG &DAG) const;
189 
190     SDValue PerformDAGCombine(SDNode *N, DAGCombinerInfo &DCI) const override;
191 
192     void computeKnownBitsForTargetNode(const SDValue Op,
193                                        APInt &KnownZero,
194                                        APInt &KnownOne,
195                                        const SelectionDAG &DAG,
196                                        unsigned Depth = 0) const override;
197 
198     SDValue
199       LowerFormalArguments(SDValue Chain,
200                            CallingConv::ID CallConv,
201                            bool isVarArg,
202                            const SmallVectorImpl<ISD::InputArg> &Ins,
203                            SDLoc dl, SelectionDAG &DAG,
204                            SmallVectorImpl<SDValue> &InVals) const override;
205 
206     SDValue
207       LowerCall(TargetLowering::CallLoweringInfo &CLI,
208                 SmallVectorImpl<SDValue> &InVals) const override;
209 
210     SDValue
211       LowerReturn(SDValue Chain,
212                   CallingConv::ID CallConv, bool isVarArg,
213                   const SmallVectorImpl<ISD::OutputArg> &Outs,
214                   const SmallVectorImpl<SDValue> &OutVals,
215                   SDLoc dl, SelectionDAG &DAG) const override;
216 
217     bool
218       CanLowerReturn(CallingConv::ID CallConv, MachineFunction &MF,
219                      bool isVarArg,
220                      const SmallVectorImpl<ISD::OutputArg> &ArgsFlags,
221                      LLVMContext &Context) const override;
222   };
223 }
224 
225 #endif
226