1 //===-- llvm/CodeGen/SelectionDAGISel.h - Common Base Class------*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file implements the SelectionDAGISel class, which is used as the common
11 // base class for SelectionDAG-based instruction selectors.
13 //===----------------------------------------------------------------------===//
15 #ifndef LLVM_CODEGEN_SELECTIONDAG_ISEL_H
16 #define LLVM_CODEGEN_SELECTIONDAG_ISEL_H
18 #include "llvm/BasicBlock.h"
19 #include "llvm/Pass.h"
20 #include "llvm/Constant.h"
21 #include "llvm/CodeGen/SelectionDAG.h"
22 #include "llvm/CodeGen/MachineFunctionPass.h"
26 class SelectionDAGBuilder;
28 class MachineRegisterInfo;
29 class MachineBasicBlock;
30 class MachineFunction;
32 class MachineModuleInfo;
35 class TargetInstrInfo;
36 class FunctionLoweringInfo;
37 class ScheduleHazardRecognizer;
39 class ScheduleDAGSDNodes;
41 /// SelectionDAGISel - This is the common base class used for SelectionDAG-based
42 /// pattern-matching instruction selectors.
43 class SelectionDAGISel : public MachineFunctionPass {
45 const TargetMachine &TM;
47 FunctionLoweringInfo *FuncInfo;
49 MachineRegisterInfo *RegInfo;
51 SelectionDAGBuilder *SDB;
52 MachineBasicBlock *BB;
55 CodeGenOpt::Level OptLevel;
58 explicit SelectionDAGISel(TargetMachine &tm,
59 CodeGenOpt::Level OL = CodeGenOpt::Default);
60 virtual ~SelectionDAGISel();
62 TargetLowering &getTargetLowering() { return TLI; }
64 virtual void getAnalysisUsage(AnalysisUsage &AU) const;
66 virtual bool runOnMachineFunction(MachineFunction &MF);
68 unsigned MakeReg(EVT VT);
70 virtual void EmitFunctionEntryCode(Function &Fn, MachineFunction &MF) {}
72 /// PreprocessISelDAG - This hook allows targets to hack on the graph before
73 /// instruction selection starts.
74 virtual void PreprocessISelDAG() {}
76 /// PostprocessISelDAG() - This hook allows the target to hack on the graph
77 /// right after selection.
78 virtual void PostprocessISelDAG() {}
80 /// Select - Main hook targets implement to select a node.
81 virtual SDNode *Select(SDNode *N) = 0;
83 /// SelectInlineAsmMemoryOperand - Select the specified address as a target
84 /// addressing mode, according to the specified constraint code. If this does
85 /// not match or is not implemented, return true. The resultant operands
86 /// (which will appear in the machine instruction) should be added to the
88 virtual bool SelectInlineAsmMemoryOperand(const SDValue &Op,
90 std::vector<SDValue> &OutOps) {
94 /// IsProfitableToFold - Returns true if it's profitable to fold the specific
95 /// operand node N of U during instruction selection that starts at Root.
96 virtual bool IsProfitableToFold(SDValue N, SDNode *U, SDNode *Root) const;
98 /// IsLegalToFold - Returns true if the specific operand node N of
99 /// U can be folded during instruction selection that starts at Root.
100 bool IsLegalToFold(SDValue N, SDNode *U, SDNode *Root,
101 bool IgnoreChains = false) const;
103 /// CreateTargetHazardRecognizer - Return a newly allocated hazard recognizer
104 /// to use for this target when scheduling the DAG.
105 virtual ScheduleHazardRecognizer *CreateTargetHazardRecognizer();
108 // Opcodes used by the DAG state machine:
109 enum BuiltinOpcodes {
112 OPC_RecordChild0, OPC_RecordChild1, OPC_RecordChild2, OPC_RecordChild3,
113 OPC_RecordChild4, OPC_RecordChild5, OPC_RecordChild6, OPC_RecordChild7,
115 OPC_CaptureFlagInput,
119 OPC_CheckPatternPredicate,
125 OPC_CheckChild0Type, OPC_CheckChild1Type, OPC_CheckChild2Type,
126 OPC_CheckChild3Type, OPC_CheckChild4Type, OPC_CheckChild5Type,
127 OPC_CheckChild6Type, OPC_CheckChild7Type,
132 OPC_CheckAndImm, OPC_CheckOrImm,
133 OPC_CheckFoldableChainNode,
137 OPC_EmitConvertToTarget,
138 OPC_EmitMergeInputChains,
148 OPFL_None = 0, // Node has no chain or flag input and isn't variadic.
149 OPFL_Chain = 1, // Node has a chain input.
150 OPFL_FlagInput = 2, // Node has a flag input.
151 OPFL_FlagOutput = 4, // Node has a flag output.
152 OPFL_MemRefs = 8, // Node gets accumulated MemRefs.
153 OPFL_Variadic0 = 1<<4, // Node is variadic, root has 0 fixed inputs.
154 OPFL_Variadic1 = 2<<4, // Node is variadic, root has 1 fixed inputs.
155 OPFL_Variadic2 = 3<<4, // Node is variadic, root has 2 fixed inputs.
156 OPFL_Variadic3 = 4<<4, // Node is variadic, root has 3 fixed inputs.
157 OPFL_Variadic4 = 5<<4, // Node is variadic, root has 4 fixed inputs.
158 OPFL_Variadic5 = 6<<4, // Node is variadic, root has 5 fixed inputs.
159 OPFL_Variadic6 = 7<<4, // Node is variadic, root has 6 fixed inputs.
161 OPFL_VariadicInfo = OPFL_Variadic6
164 /// getNumFixedFromVariadicInfo - Transform an EmitNode flags word into the
165 /// number of fixed arity values that should be skipped when copying from the
167 static inline int getNumFixedFromVariadicInfo(unsigned Flags) {
168 return ((Flags&OPFL_VariadicInfo) >> 4)-1;
173 /// DAGSize - Size of DAG being instruction selected.
177 /// ISelPosition - Node iterator marking the current position of
178 /// instruction selection as it procedes through the topologically-sorted
180 SelectionDAG::allnodes_iterator ISelPosition;
183 /// ISelUpdater - helper class to handle updates of the
184 /// instruction selection graph.
185 class ISelUpdater : public SelectionDAG::DAGUpdateListener {
186 SelectionDAG::allnodes_iterator &ISelPosition;
188 explicit ISelUpdater(SelectionDAG::allnodes_iterator &isp)
189 : ISelPosition(isp) {}
191 /// NodeDeleted - Handle nodes deleted from the graph. If the
192 /// node being deleted is the current ISelPosition node, update
195 virtual void NodeDeleted(SDNode *N, SDNode *E) {
196 if (ISelPosition == SelectionDAG::allnodes_iterator(N))
200 /// NodeUpdated - Ignore updates for now.
201 virtual void NodeUpdated(SDNode *N) {}
204 /// ReplaceUses - replace all uses of the old node F with the use
205 /// of the new node T.
206 void ReplaceUses(SDValue F, SDValue T) {
207 ISelUpdater ISU(ISelPosition);
208 CurDAG->ReplaceAllUsesOfValueWith(F, T, &ISU);
211 /// ReplaceUses - replace all uses of the old nodes F with the use
212 /// of the new nodes T.
213 void ReplaceUses(const SDValue *F, const SDValue *T, unsigned Num) {
214 ISelUpdater ISU(ISelPosition);
215 CurDAG->ReplaceAllUsesOfValuesWith(F, T, Num, &ISU);
218 /// ReplaceUses - replace all uses of the old node F with the use
219 /// of the new node T.
220 void ReplaceUses(SDNode *F, SDNode *T) {
221 ISelUpdater ISU(ISelPosition);
222 CurDAG->ReplaceAllUsesWith(F, T, &ISU);
226 /// SelectInlineAsmMemoryOperands - Calls to this are automatically generated
227 /// by tblgen. Others should not call it.
228 void SelectInlineAsmMemoryOperands(std::vector<SDValue> &Ops);
232 // Calls to these predicates are generated by tblgen.
233 bool CheckAndMask(SDValue LHS, ConstantSDNode *RHS,
234 int64_t DesiredMaskS) const;
235 bool CheckOrMask(SDValue LHS, ConstantSDNode *RHS,
236 int64_t DesiredMaskS) const;
239 /// CheckPatternPredicate - This function is generated by tblgen in the
240 /// target. It runs the specified pattern predicate and returns true if it
241 /// succeeds or false if it fails. The number is a private implementation
242 /// detail to the code tblgen produces.
243 virtual bool CheckPatternPredicate(unsigned PredNo) const {
244 assert(0 && "Tblgen should generate the implementation of this!");
248 /// CheckNodePredicate - This function is generated by tblgen in the target.
249 /// It runs node predicate number PredNo and returns true if it succeeds or
250 /// false if it fails. The number is a private implementation
251 /// detail to the code tblgen produces.
252 virtual bool CheckNodePredicate(SDNode *N, unsigned PredNo) const {
253 assert(0 && "Tblgen should generate the implementation of this!");
257 virtual bool CheckComplexPattern(SDNode *Root, SDValue N, unsigned PatternNo,
258 SmallVectorImpl<SDValue> &Result) {
259 assert(0 && "Tblgen should generate the implementation of this!");
263 virtual SDValue RunSDNodeXForm(SDValue V, unsigned XFormNo) {
264 assert(0 && "Tblgen shoudl generate this!");
268 SDNode *SelectCodeCommon(SDNode *NodeToMatch,
269 const unsigned char *MatcherTable,
274 // Calls to these functions are generated by tblgen.
275 SDNode *Select_INLINEASM(SDNode *N);
276 SDNode *Select_UNDEF(SDNode *N);
277 void CannotYetSelect(SDNode *N);
280 void DoInstructionSelection();
281 SDNode *MorphNode(SDNode *Node, unsigned TargetOpc, SDVTList VTs,
282 const SDValue *Ops, unsigned NumOps, unsigned EmitNodeInfo);
284 void SelectAllBasicBlocks(Function &Fn, MachineFunction &MF,
285 MachineModuleInfo *MMI,
287 const TargetInstrInfo &TII);
288 void FinishBasicBlock();
290 void SelectBasicBlock(BasicBlock *LLVMBB,
291 BasicBlock::iterator Begin,
292 BasicBlock::iterator End,
294 void CodeGenAndEmitDAG();
295 void LowerArguments(BasicBlock *BB);
297 void ShrinkDemandedOps();
298 void ComputeLiveOutVRegInfo();
300 void HandlePHINodesInSuccessorBlocks(BasicBlock *LLVMBB);
302 bool HandlePHINodesInSuccessorBlocksFast(BasicBlock *LLVMBB, FastISel *F);
304 /// Create the scheduler. If a specific scheduler was specified
305 /// via the SchedulerRegistry, use it, otherwise select the
306 /// one preferred by the target.
308 ScheduleDAGSDNodes *CreateScheduler();
310 /// OpcodeOffset - This is a cache used to dispatch efficiently into isel
311 /// state machines that start with a OPC_SwitchOpcode node.
312 std::vector<unsigned> OpcodeOffset;
314 void UpdateChainsAndFlags(SDNode *NodeToMatch, SDValue InputChain,
315 const SmallVectorImpl<SDNode*> &ChainNodesMatched,
316 SDValue InputFlag,const SmallVectorImpl<SDNode*> &F,
323 #endif /* LLVM_CODEGEN_SELECTIONDAG_ISEL_H */