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/CodeGen/SelectionDAG.h"
21 #include "llvm/CodeGen/MachineFunctionPass.h"
25 class SelectionDAGBuilder;
27 class MachineRegisterInfo;
28 class MachineBasicBlock;
29 class MachineFunction;
32 class TargetInstrInfo;
33 class FunctionLoweringInfo;
34 class ScheduleHazardRecognizer;
36 class ScheduleDAGSDNodes;
39 /// SelectionDAGISel - This is the common base class used for SelectionDAG-based
40 /// pattern-matching instruction selectors.
41 class SelectionDAGISel : public MachineFunctionPass {
43 const TargetMachine &TM;
44 const TargetLowering &TLI;
45 FunctionLoweringInfo *FuncInfo;
47 MachineRegisterInfo *RegInfo;
49 SelectionDAGBuilder *SDB;
52 CodeGenOpt::Level OptLevel;
55 explicit SelectionDAGISel(const TargetMachine &tm,
56 CodeGenOpt::Level OL = CodeGenOpt::Default);
57 virtual ~SelectionDAGISel();
59 const TargetLowering &getTargetLowering() { return TLI; }
61 virtual void getAnalysisUsage(AnalysisUsage &AU) const;
63 virtual bool runOnMachineFunction(MachineFunction &MF);
65 virtual void EmitFunctionEntryCode() {}
67 /// PreprocessISelDAG - This hook allows targets to hack on the graph before
68 /// instruction selection starts.
69 virtual void PreprocessISelDAG() {}
71 /// PostprocessISelDAG() - This hook allows the target to hack on the graph
72 /// right after selection.
73 virtual void PostprocessISelDAG() {}
75 /// Select - Main hook targets implement to select a node.
76 virtual SDNode *Select(SDNode *N) = 0;
78 /// SelectInlineAsmMemoryOperand - Select the specified address as a target
79 /// addressing mode, according to the specified constraint code. If this does
80 /// not match or is not implemented, return true. The resultant operands
81 /// (which will appear in the machine instruction) should be added to the
83 virtual bool SelectInlineAsmMemoryOperand(const SDValue &Op,
85 std::vector<SDValue> &OutOps) {
89 /// IsProfitableToFold - Returns true if it's profitable to fold the specific
90 /// operand node N of U during instruction selection that starts at Root.
91 virtual bool IsProfitableToFold(SDValue N, SDNode *U, SDNode *Root) const;
93 /// IsLegalToFold - Returns true if the specific operand node N of
94 /// U can be folded during instruction selection that starts at Root.
95 /// FIXME: This is a static member function because the MSP430/SystemZ/X86
96 /// targets, which uses it during isel. This could become a proper member.
97 static bool IsLegalToFold(SDValue N, SDNode *U, SDNode *Root,
98 CodeGenOpt::Level OptLevel,
99 bool IgnoreChains = false);
101 // Opcodes used by the DAG state machine:
102 enum BuiltinOpcodes {
105 OPC_RecordChild0, OPC_RecordChild1, OPC_RecordChild2, OPC_RecordChild3,
106 OPC_RecordChild4, OPC_RecordChild5, OPC_RecordChild6, OPC_RecordChild7,
108 OPC_CaptureGlueInput,
112 OPC_CheckPatternPredicate,
118 OPC_CheckChild0Type, OPC_CheckChild1Type, OPC_CheckChild2Type,
119 OPC_CheckChild3Type, OPC_CheckChild4Type, OPC_CheckChild5Type,
120 OPC_CheckChild6Type, OPC_CheckChild7Type,
125 OPC_CheckAndImm, OPC_CheckOrImm,
126 OPC_CheckFoldableChainNode,
131 OPC_EmitConvertToTarget,
132 OPC_EmitMergeInputChains,
133 OPC_EmitMergeInputChains1_0,
134 OPC_EmitMergeInputChains1_1,
144 OPFL_None = 0, // Node has no chain or glue input and isn't variadic.
145 OPFL_Chain = 1, // Node has a chain input.
146 OPFL_GlueInput = 2, // Node has a glue input.
147 OPFL_GlueOutput = 4, // Node has a glue output.
148 OPFL_MemRefs = 8, // Node gets accumulated MemRefs.
149 OPFL_Variadic0 = 1<<4, // Node is variadic, root has 0 fixed inputs.
150 OPFL_Variadic1 = 2<<4, // Node is variadic, root has 1 fixed inputs.
151 OPFL_Variadic2 = 3<<4, // Node is variadic, root has 2 fixed inputs.
152 OPFL_Variadic3 = 4<<4, // Node is variadic, root has 3 fixed inputs.
153 OPFL_Variadic4 = 5<<4, // Node is variadic, root has 4 fixed inputs.
154 OPFL_Variadic5 = 6<<4, // Node is variadic, root has 5 fixed inputs.
155 OPFL_Variadic6 = 7<<4, // Node is variadic, root has 6 fixed inputs.
157 OPFL_VariadicInfo = OPFL_Variadic6
160 /// getNumFixedFromVariadicInfo - Transform an EmitNode flags word into the
161 /// number of fixed arity values that should be skipped when copying from the
163 static inline int getNumFixedFromVariadicInfo(unsigned Flags) {
164 return ((Flags&OPFL_VariadicInfo) >> 4)-1;
169 /// DAGSize - Size of DAG being instruction selected.
173 /// ISelPosition - Node iterator marking the current position of
174 /// instruction selection as it procedes through the topologically-sorted
176 SelectionDAG::allnodes_iterator ISelPosition;
179 /// ISelUpdater - helper class to handle updates of the
180 /// instruction selection graph.
181 class ISelUpdater : public SelectionDAG::DAGUpdateListener {
182 SelectionDAG::allnodes_iterator &ISelPosition;
184 explicit ISelUpdater(SelectionDAG::allnodes_iterator &isp)
185 : ISelPosition(isp) {}
187 /// NodeDeleted - Handle nodes deleted from the graph. If the
188 /// node being deleted is the current ISelPosition node, update
191 virtual void NodeDeleted(SDNode *N, SDNode *E) {
192 if (ISelPosition == SelectionDAG::allnodes_iterator(N))
196 /// NodeUpdated - Ignore updates for now.
197 virtual void NodeUpdated(SDNode *N) {}
200 /// ReplaceUses - replace all uses of the old node F with the use
201 /// of the new node T.
202 void ReplaceUses(SDValue F, SDValue T) {
203 ISelUpdater ISU(ISelPosition);
204 CurDAG->ReplaceAllUsesOfValueWith(F, T, &ISU);
207 /// ReplaceUses - replace all uses of the old nodes F with the use
208 /// of the new nodes T.
209 void ReplaceUses(const SDValue *F, const SDValue *T, unsigned Num) {
210 ISelUpdater ISU(ISelPosition);
211 CurDAG->ReplaceAllUsesOfValuesWith(F, T, Num, &ISU);
214 /// ReplaceUses - replace all uses of the old node F with the use
215 /// of the new node T.
216 void ReplaceUses(SDNode *F, SDNode *T) {
217 ISelUpdater ISU(ISelPosition);
218 CurDAG->ReplaceAllUsesWith(F, T, &ISU);
222 /// SelectInlineAsmMemoryOperands - Calls to this are automatically generated
223 /// by tblgen. Others should not call it.
224 void SelectInlineAsmMemoryOperands(std::vector<SDValue> &Ops);
228 // Calls to these predicates are generated by tblgen.
229 bool CheckAndMask(SDValue LHS, ConstantSDNode *RHS,
230 int64_t DesiredMaskS) const;
231 bool CheckOrMask(SDValue LHS, ConstantSDNode *RHS,
232 int64_t DesiredMaskS) const;
235 /// CheckPatternPredicate - This function is generated by tblgen in the
236 /// target. It runs the specified pattern predicate and returns true if it
237 /// succeeds or false if it fails. The number is a private implementation
238 /// detail to the code tblgen produces.
239 virtual bool CheckPatternPredicate(unsigned PredNo) const {
240 assert(0 && "Tblgen should generate the implementation of this!");
244 /// CheckNodePredicate - This function is generated by tblgen in the target.
245 /// It runs node predicate number PredNo and returns true if it succeeds or
246 /// false if it fails. The number is a private implementation
247 /// detail to the code tblgen produces.
248 virtual bool CheckNodePredicate(SDNode *N, unsigned PredNo) const {
249 assert(0 && "Tblgen should generate the implementation of this!");
253 virtual bool CheckComplexPattern(SDNode *Root, SDNode *Parent, SDValue N,
255 SmallVectorImpl<std::pair<SDValue, SDNode*> > &Result) {
256 assert(0 && "Tblgen should generate the implementation of this!");
260 virtual SDValue RunSDNodeXForm(SDValue V, unsigned XFormNo) {
261 assert(0 && "Tblgen should generate this!");
265 SDNode *SelectCodeCommon(SDNode *NodeToMatch,
266 const unsigned char *MatcherTable,
271 // Calls to these functions are generated by tblgen.
272 SDNode *Select_INLINEASM(SDNode *N);
273 SDNode *Select_UNDEF(SDNode *N);
274 void CannotYetSelect(SDNode *N);
277 void DoInstructionSelection();
278 SDNode *MorphNode(SDNode *Node, unsigned TargetOpc, SDVTList VTs,
279 const SDValue *Ops, unsigned NumOps, unsigned EmitNodeInfo);
281 void PrepareEHLandingPad();
282 void SelectAllBasicBlocks(const Function &Fn);
283 bool TryToFoldFastISelLoad(const LoadInst *LI, const Instruction *FoldInst,
285 void FinishBasicBlock();
287 void SelectBasicBlock(BasicBlock::const_iterator Begin,
288 BasicBlock::const_iterator End,
290 void CodeGenAndEmitDAG();
291 void LowerArguments(const BasicBlock *BB);
293 void ComputeLiveOutVRegInfo();
295 /// Create the scheduler. If a specific scheduler was specified
296 /// via the SchedulerRegistry, use it, otherwise select the
297 /// one preferred by the target.
299 ScheduleDAGSDNodes *CreateScheduler();
301 /// OpcodeOffset - This is a cache used to dispatch efficiently into isel
302 /// state machines that start with a OPC_SwitchOpcode node.
303 std::vector<unsigned> OpcodeOffset;
305 void UpdateChainsAndGlue(SDNode *NodeToMatch, SDValue InputChain,
306 const SmallVectorImpl<SDNode*> &ChainNodesMatched,
307 SDValue InputGlue, const SmallVectorImpl<SDNode*> &F,
314 #endif /* LLVM_CODEGEN_SELECTIONDAG_ISEL_H */