1 //===-- llvm/CodeGen/SelectionDAGISel.h - Common Base Class------*- 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 implements the SelectionDAGISel class, which is used as the common 11 // base class for SelectionDAG-based instruction selectors. 12 // 13 //===----------------------------------------------------------------------===// 14 15 #ifndef LLVM_CODEGEN_SELECTIONDAGISEL_H 16 #define LLVM_CODEGEN_SELECTIONDAGISEL_H 17 18 #include "llvm/CodeGen/MachineFunctionPass.h" 19 #include "llvm/CodeGen/SelectionDAG.h" 20 #include "llvm/IR/BasicBlock.h" 21 #include "llvm/Pass.h" 22 #include "llvm/Target/TargetSubtargetInfo.h" 23 24 namespace llvm { 25 class FastISel; 26 class SelectionDAGBuilder; 27 class SDValue; 28 class MachineRegisterInfo; 29 class MachineBasicBlock; 30 class MachineFunction; 31 class MachineInstr; 32 class TargetLowering; 33 class TargetLibraryInfo; 34 class FunctionLoweringInfo; 35 class ScheduleHazardRecognizer; 36 class GCFunctionInfo; 37 class ScheduleDAGSDNodes; 38 class LoadInst; 39 40 /// SelectionDAGISel - This is the common base class used for SelectionDAG-based 41 /// pattern-matching instruction selectors. 42 class SelectionDAGISel : public MachineFunctionPass { 43 public: 44 TargetMachine &TM; 45 const TargetLibraryInfo *LibInfo; 46 FunctionLoweringInfo *FuncInfo; 47 MachineFunction *MF; 48 MachineRegisterInfo *RegInfo; 49 SelectionDAG *CurDAG; 50 SelectionDAGBuilder *SDB; 51 AliasAnalysis *AA; 52 GCFunctionInfo *GFI; 53 CodeGenOpt::Level OptLevel; 54 const TargetInstrInfo *TII; 55 const TargetLowering *TLI; 56 57 static char ID; 58 59 explicit SelectionDAGISel(TargetMachine &tm, 60 CodeGenOpt::Level OL = CodeGenOpt::Default); 61 ~SelectionDAGISel() override; 62 63 const TargetLowering *getTargetLowering() const { return TLI; } 64 65 void getAnalysisUsage(AnalysisUsage &AU) const override; 66 67 bool runOnMachineFunction(MachineFunction &MF) override; 68 69 virtual void EmitFunctionEntryCode() {} 70 71 /// PreprocessISelDAG - This hook allows targets to hack on the graph before 72 /// instruction selection starts. 73 virtual void PreprocessISelDAG() {} 74 75 /// PostprocessISelDAG() - This hook allows the target to hack on the graph 76 /// right after selection. 77 virtual void PostprocessISelDAG() {} 78 79 /// Select - Main hook targets implement to select a node. 80 virtual SDNode *Select(SDNode *N) = 0; 81 82 /// SelectInlineAsmMemoryOperand - Select the specified address as a target 83 /// addressing mode, according to the specified constraint. If this does 84 /// not match or is not implemented, return true. The resultant operands 85 /// (which will appear in the machine instruction) should be added to the 86 /// OutOps vector. 87 virtual bool SelectInlineAsmMemoryOperand(const SDValue &Op, 88 unsigned ConstraintID, 89 std::vector<SDValue> &OutOps) { 90 return true; 91 } 92 93 /// IsProfitableToFold - Returns true if it's profitable to fold the specific 94 /// operand node N of U during instruction selection that starts at Root. 95 virtual bool IsProfitableToFold(SDValue N, SDNode *U, SDNode *Root) const; 96 97 /// IsLegalToFold - Returns true if the specific operand node N of 98 /// U can be folded during instruction selection that starts at Root. 99 /// FIXME: This is a static member function because the MSP430/X86 100 /// targets, which uses it during isel. This could become a proper member. 101 static bool IsLegalToFold(SDValue N, SDNode *U, SDNode *Root, 102 CodeGenOpt::Level OptLevel, 103 bool IgnoreChains = false); 104 105 // Opcodes used by the DAG state machine: 106 enum BuiltinOpcodes { 107 OPC_Scope, 108 OPC_RecordNode, 109 OPC_RecordChild0, OPC_RecordChild1, OPC_RecordChild2, OPC_RecordChild3, 110 OPC_RecordChild4, OPC_RecordChild5, OPC_RecordChild6, OPC_RecordChild7, 111 OPC_RecordMemRef, 112 OPC_CaptureGlueInput, 113 OPC_MoveChild, 114 OPC_MoveParent, 115 OPC_CheckSame, 116 OPC_CheckChild0Same, OPC_CheckChild1Same, 117 OPC_CheckChild2Same, OPC_CheckChild3Same, 118 OPC_CheckPatternPredicate, 119 OPC_CheckPredicate, 120 OPC_CheckOpcode, 121 OPC_SwitchOpcode, 122 OPC_CheckType, 123 OPC_SwitchType, 124 OPC_CheckChild0Type, OPC_CheckChild1Type, OPC_CheckChild2Type, 125 OPC_CheckChild3Type, OPC_CheckChild4Type, OPC_CheckChild5Type, 126 OPC_CheckChild6Type, OPC_CheckChild7Type, 127 OPC_CheckInteger, 128 OPC_CheckChild0Integer, OPC_CheckChild1Integer, OPC_CheckChild2Integer, 129 OPC_CheckChild3Integer, OPC_CheckChild4Integer, 130 OPC_CheckCondCode, 131 OPC_CheckValueType, 132 OPC_CheckComplexPat, 133 OPC_CheckAndImm, OPC_CheckOrImm, 134 OPC_CheckFoldableChainNode, 135 136 OPC_EmitInteger, 137 OPC_EmitRegister, 138 OPC_EmitRegister2, 139 OPC_EmitConvertToTarget, 140 OPC_EmitMergeInputChains, 141 OPC_EmitMergeInputChains1_0, 142 OPC_EmitMergeInputChains1_1, 143 OPC_EmitCopyToReg, 144 OPC_EmitNodeXForm, 145 OPC_EmitNode, 146 OPC_MorphNodeTo, 147 OPC_MarkGlueResults, 148 OPC_CompleteMatch 149 }; 150 151 enum { 152 OPFL_None = 0, // Node has no chain or glue input and isn't variadic. 153 OPFL_Chain = 1, // Node has a chain input. 154 OPFL_GlueInput = 2, // Node has a glue input. 155 OPFL_GlueOutput = 4, // Node has a glue output. 156 OPFL_MemRefs = 8, // Node gets accumulated MemRefs. 157 OPFL_Variadic0 = 1<<4, // Node is variadic, root has 0 fixed inputs. 158 OPFL_Variadic1 = 2<<4, // Node is variadic, root has 1 fixed inputs. 159 OPFL_Variadic2 = 3<<4, // Node is variadic, root has 2 fixed inputs. 160 OPFL_Variadic3 = 4<<4, // Node is variadic, root has 3 fixed inputs. 161 OPFL_Variadic4 = 5<<4, // Node is variadic, root has 4 fixed inputs. 162 OPFL_Variadic5 = 6<<4, // Node is variadic, root has 5 fixed inputs. 163 OPFL_Variadic6 = 7<<4, // Node is variadic, root has 6 fixed inputs. 164 165 OPFL_VariadicInfo = OPFL_Variadic6 166 }; 167 168 /// getNumFixedFromVariadicInfo - Transform an EmitNode flags word into the 169 /// number of fixed arity values that should be skipped when copying from the 170 /// root. 171 static inline int getNumFixedFromVariadicInfo(unsigned Flags) { 172 return ((Flags&OPFL_VariadicInfo) >> 4)-1; 173 } 174 175 176 protected: 177 /// DAGSize - Size of DAG being instruction selected. 178 /// 179 unsigned DAGSize; 180 181 /// ReplaceUses - replace all uses of the old node F with the use 182 /// of the new node T. 183 void ReplaceUses(SDValue F, SDValue T) { 184 CurDAG->ReplaceAllUsesOfValueWith(F, T); 185 } 186 187 /// ReplaceUses - replace all uses of the old nodes F with the use 188 /// of the new nodes T. 189 void ReplaceUses(const SDValue *F, const SDValue *T, unsigned Num) { 190 CurDAG->ReplaceAllUsesOfValuesWith(F, T, Num); 191 } 192 193 /// ReplaceUses - replace all uses of the old node F with the use 194 /// of the new node T. 195 void ReplaceUses(SDNode *F, SDNode *T) { 196 CurDAG->ReplaceAllUsesWith(F, T); 197 } 198 199 200 /// SelectInlineAsmMemoryOperands - Calls to this are automatically generated 201 /// by tblgen. Others should not call it. 202 void SelectInlineAsmMemoryOperands(std::vector<SDValue> &Ops, SDLoc DL); 203 204 205 public: 206 // Calls to these predicates are generated by tblgen. 207 bool CheckAndMask(SDValue LHS, ConstantSDNode *RHS, 208 int64_t DesiredMaskS) const; 209 bool CheckOrMask(SDValue LHS, ConstantSDNode *RHS, 210 int64_t DesiredMaskS) const; 211 212 213 /// CheckPatternPredicate - This function is generated by tblgen in the 214 /// target. It runs the specified pattern predicate and returns true if it 215 /// succeeds or false if it fails. The number is a private implementation 216 /// detail to the code tblgen produces. 217 virtual bool CheckPatternPredicate(unsigned PredNo) const { 218 llvm_unreachable("Tblgen should generate the implementation of this!"); 219 } 220 221 /// CheckNodePredicate - This function is generated by tblgen in the target. 222 /// It runs node predicate number PredNo and returns true if it succeeds or 223 /// false if it fails. The number is a private implementation 224 /// detail to the code tblgen produces. 225 virtual bool CheckNodePredicate(SDNode *N, unsigned PredNo) const { 226 llvm_unreachable("Tblgen should generate the implementation of this!"); 227 } 228 229 virtual bool CheckComplexPattern(SDNode *Root, SDNode *Parent, SDValue N, 230 unsigned PatternNo, 231 SmallVectorImpl<std::pair<SDValue, SDNode*> > &Result) { 232 llvm_unreachable("Tblgen should generate the implementation of this!"); 233 } 234 235 virtual SDValue RunSDNodeXForm(SDValue V, unsigned XFormNo) { 236 llvm_unreachable("Tblgen should generate this!"); 237 } 238 239 SDNode *SelectCodeCommon(SDNode *NodeToMatch, 240 const unsigned char *MatcherTable, 241 unsigned TableSize); 242 243 /// \brief Return true if complex patterns for this target can mutate the 244 /// DAG. 245 virtual bool ComplexPatternFuncMutatesDAG() const { 246 return false; 247 } 248 249 private: 250 251 // Calls to these functions are generated by tblgen. 252 SDNode *Select_INLINEASM(SDNode *N); 253 SDNode *Select_READ_REGISTER(SDNode *N); 254 SDNode *Select_WRITE_REGISTER(SDNode *N); 255 SDNode *Select_UNDEF(SDNode *N); 256 void CannotYetSelect(SDNode *N); 257 258 private: 259 void DoInstructionSelection(); 260 SDNode *MorphNode(SDNode *Node, unsigned TargetOpc, SDVTList VTs, 261 ArrayRef<SDValue> Ops, unsigned EmitNodeInfo); 262 263 /// Prepares the landing pad to take incoming values or do other EH 264 /// personality specific tasks. Returns true if the block should be 265 /// instruction selected, false if no code should be emitted for it. 266 bool PrepareEHLandingPad(); 267 268 /// \brief Perform instruction selection on all basic blocks in the function. 269 void SelectAllBasicBlocks(const Function &Fn); 270 271 /// \brief Perform instruction selection on a single basic block, for 272 /// instructions between \p Begin and \p End. \p HadTailCall will be set 273 /// to true if a call in the block was translated as a tail call. 274 void SelectBasicBlock(BasicBlock::const_iterator Begin, 275 BasicBlock::const_iterator End, 276 bool &HadTailCall); 277 void FinishBasicBlock(); 278 279 void CodeGenAndEmitDAG(); 280 281 /// \brief Generate instructions for lowering the incoming arguments of the 282 /// given function. 283 void LowerArguments(const Function &F); 284 285 void ComputeLiveOutVRegInfo(); 286 287 /// Create the scheduler. If a specific scheduler was specified 288 /// via the SchedulerRegistry, use it, otherwise select the 289 /// one preferred by the target. 290 /// 291 ScheduleDAGSDNodes *CreateScheduler(); 292 293 /// OpcodeOffset - This is a cache used to dispatch efficiently into isel 294 /// state machines that start with a OPC_SwitchOpcode node. 295 std::vector<unsigned> OpcodeOffset; 296 297 void UpdateChainsAndGlue(SDNode *NodeToMatch, SDValue InputChain, 298 const SmallVectorImpl<SDNode*> &ChainNodesMatched, 299 SDValue InputGlue, const SmallVectorImpl<SDNode*> &F, 300 bool isMorphNodeTo); 301 302 }; 303 304 } 305 306 #endif /* LLVM_CODEGEN_SELECTIONDAGISEL_H */ 307
