1 //- WebAssemblyISelLowering.h - WebAssembly 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 /// \file
11 /// This file defines the interfaces that WebAssembly uses to lower LLVM
12 /// code into a selection DAG.
13 ///
14 //===----------------------------------------------------------------------===//
15 
16 #ifndef LLVM_LIB_TARGET_WEBASSEMBLY_WEBASSEMBLYISELLOWERING_H
17 #define LLVM_LIB_TARGET_WEBASSEMBLY_WEBASSEMBLYISELLOWERING_H
18 
19 #include "llvm/CodeGen/TargetLowering.h"
20 
21 namespace llvm {
22 
23 namespace WebAssemblyISD {
24 
25 enum NodeType : unsigned {
26   FIRST_NUMBER = ISD::BUILTIN_OP_END,
27 #define HANDLE_NODETYPE(NODE) NODE,
28 #include "WebAssemblyISD.def"
29 #undef HANDLE_NODETYPE
30 };
31 
32 } // end namespace WebAssemblyISD
33 
34 class WebAssemblySubtarget;
35 class WebAssemblyTargetMachine;
36 
37 class WebAssemblyTargetLowering final : public TargetLowering {
38 public:
39   WebAssemblyTargetLowering(const TargetMachine &TM,
40                             const WebAssemblySubtarget &STI);
41 
42 private:
43   /// Keep a pointer to the WebAssemblySubtarget around so that we can make the
44   /// right decision when generating code for different targets.
45   const WebAssemblySubtarget *Subtarget;
46 
47   AtomicExpansionKind shouldExpandAtomicRMWInIR(AtomicRMWInst *) const override;
48   FastISel *createFastISel(FunctionLoweringInfo &FuncInfo,
49                            const TargetLibraryInfo *LibInfo) const override;
50   bool isOffsetFoldingLegal(const GlobalAddressSDNode *GA) const override;
51   MVT getScalarShiftAmountTy(const DataLayout &DL, EVT) const override;
52   MachineBasicBlock *
53   EmitInstrWithCustomInserter(MachineInstr &MI,
54                               MachineBasicBlock *MBB) const override;
55   const char *getTargetNodeName(unsigned Opcode) const override;
56   std::pair<unsigned, const TargetRegisterClass *>
57   getRegForInlineAsmConstraint(const TargetRegisterInfo *TRI,
58                                StringRef Constraint, MVT VT) const override;
59   bool isCheapToSpeculateCttz() const override;
60   bool isCheapToSpeculateCtlz() const override;
61   bool isLegalAddressingMode(const DataLayout &DL, const AddrMode &AM, Type *Ty,
62                              unsigned AS,
63                              Instruction *I = nullptr) const override;
64   bool allowsMisalignedMemoryAccesses(EVT, unsigned AddrSpace, unsigned Align,
65                                       bool *Fast) const override;
66   bool isIntDivCheap(EVT VT, AttributeList Attr) const override;
67 
68   EVT getSetCCResultType(const DataLayout &DL, LLVMContext &Context,
69                          EVT VT) const override;
70   bool getTgtMemIntrinsic(IntrinsicInfo &Info, const CallInst &I,
71                           MachineFunction &MF,
72                           unsigned Intrinsic) const override;
73 
74   SDValue LowerCall(CallLoweringInfo &CLI,
75                     SmallVectorImpl<SDValue> &InVals) const override;
76   bool CanLowerReturn(CallingConv::ID CallConv, MachineFunction &MF,
77                       bool isVarArg,
78                       const SmallVectorImpl<ISD::OutputArg> &Outs,
79                       LLVMContext &Context) const override;
80   SDValue LowerReturn(SDValue Chain, CallingConv::ID CallConv, bool isVarArg,
81                       const SmallVectorImpl<ISD::OutputArg> &Outs,
82                       const SmallVectorImpl<SDValue> &OutVals, const SDLoc &dl,
83                       SelectionDAG &DAG) const override;
84   SDValue LowerFormalArguments(SDValue Chain, CallingConv::ID CallConv,
85                                bool IsVarArg,
86                                const SmallVectorImpl<ISD::InputArg> &Ins,
87                                const SDLoc &DL, SelectionDAG &DAG,
88                                SmallVectorImpl<SDValue> &InVals) const override;
89 
90   // Custom lowering hooks.
91   SDValue LowerOperation(SDValue Op, SelectionDAG &DAG) const override;
92   SDValue LowerFrameIndex(SDValue Op, SelectionDAG &DAG) const;
93   SDValue LowerFRAMEADDR(SDValue Op, SelectionDAG &DAG) const;
94   SDValue LowerGlobalAddress(SDValue Op, SelectionDAG &DAG) const;
95   SDValue LowerExternalSymbol(SDValue Op, SelectionDAG &DAG) const;
96   SDValue LowerBR_JT(SDValue Op, SelectionDAG &DAG) const;
97   SDValue LowerJumpTable(SDValue Op, SelectionDAG &DAG) const;
98   SDValue LowerVASTART(SDValue Op, SelectionDAG &DAG) const;
99   SDValue LowerCopyToReg(SDValue Op, SelectionDAG &DAG) const;
100   SDValue LowerINTRINSIC_WO_CHAIN(SDValue Op, SelectionDAG &DAG) const;
101   SDValue LowerVECTOR_SHUFFLE(SDValue Op, SelectionDAG &DAG) const;
102   SDValue LowerShift(SDValue Op, SelectionDAG &DAG) const;
103 };
104 
105 namespace WebAssembly {
106 FastISel *createFastISel(FunctionLoweringInfo &funcInfo,
107                          const TargetLibraryInfo *libInfo);
108 } // end namespace WebAssembly
109 
110 } // end namespace llvm
111 
112 #endif
113