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   FastISel *createFastISel(FunctionLoweringInfo &FuncInfo,
48                            const TargetLibraryInfo *LibInfo) const override;
49   bool isOffsetFoldingLegal(const GlobalAddressSDNode *GA) const override;
50   MVT getScalarShiftAmountTy(const DataLayout &DL, EVT) const override;
51   MachineBasicBlock *
52   EmitInstrWithCustomInserter(MachineInstr &MI,
53                               MachineBasicBlock *MBB) const override;
54   const char *getTargetNodeName(unsigned Opcode) const override;
55   std::pair<unsigned, const TargetRegisterClass *> getRegForInlineAsmConstraint(
56       const TargetRegisterInfo *TRI, StringRef Constraint,
57       MVT VT) const override;
58   bool isCheapToSpeculateCttz() const override;
59   bool isCheapToSpeculateCtlz() const override;
60   bool isLegalAddressingMode(const DataLayout &DL, const AddrMode &AM, Type *Ty,
61                              unsigned AS,
62                              Instruction *I = nullptr) const override;
63   bool allowsMisalignedMemoryAccesses(EVT, unsigned AddrSpace, unsigned Align,
64                                       bool *Fast) const override;
65   bool isIntDivCheap(EVT VT, AttributeList Attr) const override;
66 
67   EVT getSetCCResultType(const DataLayout &DL, LLVMContext &Context,
68                          EVT VT) const override;
69 
70   SDValue LowerCall(CallLoweringInfo &CLI,
71                     SmallVectorImpl<SDValue> &InVals) const override;
72   bool CanLowerReturn(CallingConv::ID CallConv, MachineFunction &MF,
73                       bool isVarArg,
74                       const SmallVectorImpl<ISD::OutputArg> &Outs,
75                       LLVMContext &Context) const override;
76   SDValue LowerReturn(SDValue Chain, CallingConv::ID CallConv, bool isVarArg,
77                       const SmallVectorImpl<ISD::OutputArg> &Outs,
78                       const SmallVectorImpl<SDValue> &OutVals, const SDLoc &dl,
79                       SelectionDAG &DAG) const override;
80   SDValue LowerFormalArguments(SDValue Chain, CallingConv::ID CallConv,
81                                bool IsVarArg,
82                                const SmallVectorImpl<ISD::InputArg> &Ins,
83                                const SDLoc &DL, SelectionDAG &DAG,
84                                SmallVectorImpl<SDValue> &InVals) const override;
85 
86   // Custom lowering hooks.
87   SDValue LowerOperation(SDValue Op, SelectionDAG &DAG) const override;
88   SDValue LowerFrameIndex(SDValue Op, SelectionDAG &DAG) const;
89   SDValue LowerFRAMEADDR(SDValue Op, SelectionDAG &DAG) const;
90   SDValue LowerGlobalAddress(SDValue Op, SelectionDAG &DAG) const;
91   SDValue LowerExternalSymbol(SDValue Op, SelectionDAG &DAG) const;
92   SDValue LowerBR_JT(SDValue Op, SelectionDAG &DAG) const;
93   SDValue LowerJumpTable(SDValue Op, SelectionDAG &DAG) const;
94   SDValue LowerVASTART(SDValue Op, SelectionDAG &DAG) const;
95   SDValue LowerCopyToReg(SDValue Op, SelectionDAG &DAG) const;
96   SDValue LowerINTRINSIC_WO_CHAIN(SDValue Op, SelectionDAG &DAG) const;
97 };
98 
99 namespace WebAssembly {
100 FastISel *createFastISel(FunctionLoweringInfo &funcInfo,
101                          const TargetLibraryInfo *libInfo);
102 }  // end namespace WebAssembly
103 
104 }  // end namespace llvm
105 
106 #endif
107