1 //- WebAssemblyISelLowering.h - WebAssembly 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 /// \file
10 /// This file defines the interfaces that WebAssembly uses to lower LLVM
11 /// code into a selection DAG.
12 ///
13 //===----------------------------------------------------------------------===//
14 
15 #ifndef LLVM_LIB_TARGET_WEBASSEMBLY_WEBASSEMBLYISELLOWERING_H
16 #define LLVM_LIB_TARGET_WEBASSEMBLY_WEBASSEMBLYISELLOWERING_H
17 
18 #include "llvm/CodeGen/TargetLowering.h"
19 
20 namespace llvm {
21 
22 namespace WebAssemblyISD {
23 
24 enum NodeType : unsigned {
25   FIRST_NUMBER = ISD::BUILTIN_OP_END,
26 #define HANDLE_NODETYPE(NODE) NODE,
27 #define HANDLE_MEM_NODETYPE(NODE)
28 #include "WebAssemblyISD.def"
29   FIRST_MEM_OPCODE = ISD::FIRST_TARGET_MEMORY_OPCODE,
30 #undef HANDLE_NODETYPE
31 #undef HANDLE_MEM_NODETYPE
32 #define HANDLE_NODETYPE(NODE)
33 #define HANDLE_MEM_NODETYPE(NODE) NODE,
34 #include "WebAssemblyISD.def"
35 #undef HANDLE_NODETYPE
36 #undef HANDLE_MEM_NODETYPE
37 };
38 
39 } // end namespace WebAssemblyISD
40 
41 class WebAssemblySubtarget;
42 class WebAssemblyTargetMachine;
43 
44 class WebAssemblyTargetLowering final : public TargetLowering {
45 public:
46   WebAssemblyTargetLowering(const TargetMachine &TM,
47                             const WebAssemblySubtarget &STI);
48 
49 private:
50   /// Keep a pointer to the WebAssemblySubtarget around so that we can make the
51   /// right decision when generating code for different targets.
52   const WebAssemblySubtarget *Subtarget;
53 
54   AtomicExpansionKind shouldExpandAtomicRMWInIR(AtomicRMWInst *) const override;
55   FastISel *createFastISel(FunctionLoweringInfo &FuncInfo,
56                            const TargetLibraryInfo *LibInfo) const override;
57   MVT getScalarShiftAmountTy(const DataLayout &DL, EVT) const override;
58   MachineBasicBlock *
59   EmitInstrWithCustomInserter(MachineInstr &MI,
60                               MachineBasicBlock *MBB) const override;
61   const char *getTargetNodeName(unsigned Opcode) const override;
62   std::pair<unsigned, const TargetRegisterClass *>
63   getRegForInlineAsmConstraint(const TargetRegisterInfo *TRI,
64                                StringRef Constraint, MVT VT) const override;
65   bool isCheapToSpeculateCttz() const override;
66   bool isCheapToSpeculateCtlz() const override;
67   bool isLegalAddressingMode(const DataLayout &DL, const AddrMode &AM, Type *Ty,
68                              unsigned AS,
69                              Instruction *I = nullptr) const override;
70   bool allowsMisalignedMemoryAccesses(EVT, unsigned AddrSpace, unsigned Align,
71                                       MachineMemOperand::Flags Flags,
72                                       bool *Fast) const override;
73   bool isIntDivCheap(EVT VT, AttributeList Attr) const override;
74   bool isVectorLoadExtDesirable(SDValue ExtVal) const override;
75   EVT getSetCCResultType(const DataLayout &DL, LLVMContext &Context,
76                          EVT VT) const override;
77   bool getTgtMemIntrinsic(IntrinsicInfo &Info, const CallInst &I,
78                           MachineFunction &MF,
79                           unsigned Intrinsic) const override;
80 
81   SDValue LowerCall(CallLoweringInfo &CLI,
82                     SmallVectorImpl<SDValue> &InVals) const override;
83   bool CanLowerReturn(CallingConv::ID CallConv, MachineFunction &MF,
84                       bool isVarArg,
85                       const SmallVectorImpl<ISD::OutputArg> &Outs,
86                       LLVMContext &Context) const override;
87   SDValue LowerReturn(SDValue Chain, CallingConv::ID CallConv, bool isVarArg,
88                       const SmallVectorImpl<ISD::OutputArg> &Outs,
89                       const SmallVectorImpl<SDValue> &OutVals, const SDLoc &dl,
90                       SelectionDAG &DAG) const override;
91   SDValue LowerFormalArguments(SDValue Chain, CallingConv::ID CallConv,
92                                bool IsVarArg,
93                                const SmallVectorImpl<ISD::InputArg> &Ins,
94                                const SDLoc &DL, SelectionDAG &DAG,
95                                SmallVectorImpl<SDValue> &InVals) const override;
96 
97   void ReplaceNodeResults(SDNode *N, SmallVectorImpl<SDValue> &Results,
98                           SelectionDAG &DAG) const override;
99 
getClearCacheBuiltinName()100   const char *getClearCacheBuiltinName() const override {
101     report_fatal_error("llvm.clear_cache is not supported on wasm");
102   }
103 
104   // Custom lowering hooks.
105   SDValue LowerOperation(SDValue Op, SelectionDAG &DAG) const override;
106   SDValue LowerFrameIndex(SDValue Op, SelectionDAG &DAG) const;
107   SDValue LowerRETURNADDR(SDValue Op, SelectionDAG &DAG) const;
108   SDValue LowerFRAMEADDR(SDValue Op, SelectionDAG &DAG) const;
109   SDValue LowerGlobalAddress(SDValue Op, SelectionDAG &DAG) const;
110   SDValue LowerExternalSymbol(SDValue Op, SelectionDAG &DAG) const;
111   SDValue LowerBR_JT(SDValue Op, SelectionDAG &DAG) const;
112   SDValue LowerJumpTable(SDValue Op, SelectionDAG &DAG) const;
113   SDValue LowerVASTART(SDValue Op, SelectionDAG &DAG) const;
114   SDValue LowerCopyToReg(SDValue Op, SelectionDAG &DAG) const;
115   SDValue LowerIntrinsic(SDValue Op, SelectionDAG &DAG) const;
116   SDValue LowerSIGN_EXTEND_INREG(SDValue Op, SelectionDAG &DAG) const;
117   SDValue LowerBUILD_VECTOR(SDValue Op, SelectionDAG &DAG) const;
118   SDValue LowerVECTOR_SHUFFLE(SDValue Op, SelectionDAG &DAG) const;
119   SDValue LowerSETCC(SDValue Op, SelectionDAG &DAG) const;
120   SDValue LowerAccessVectorElement(SDValue Op, SelectionDAG &DAG) const;
121   SDValue LowerShift(SDValue Op, SelectionDAG &DAG) const;
122 };
123 
124 namespace WebAssembly {
125 FastISel *createFastISel(FunctionLoweringInfo &funcInfo,
126                          const TargetLibraryInfo *libInfo);
127 } // end namespace WebAssembly
128 
129 } // end namespace llvm
130 
131 #endif
132