1 //===-- llvm/CodeGen/SelectionDAG.h - InstSelection DAG ---------*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file was developed by the LLVM research group and is distributed under
6 // the University of Illinois Open Source License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file declares the SelectionDAG class, and transitively defines the
11 // SDNode class and subclasses.
13 //===----------------------------------------------------------------------===//
15 #ifndef LLVM_CODEGEN_SELECTIONDAG_H
16 #define LLVM_CODEGEN_SELECTIONDAG_H
18 #include "llvm/CodeGen/SelectionDAGNodes.h"
20 #include <string> // FIXME remove eventually, turning map into const char* map.
25 class MachineFunction;
27 /// SelectionDAG class - This is used to represent a portion of an LLVM function
28 /// in a low-level Data Dependence DAG representation suitable for instruction
29 /// selection. This DAG is constructed as the first step of instruction
30 /// selection in order to allow implementation of machine specific optimizations
31 /// and code simplifications.
33 /// The representation used by the SelectionDAG is a target-independent
34 /// representation, which has some similarities to the GCC RTL representation,
35 /// but is significantly more simple, powerful, and is a graph form instead of a
42 // Root - The root of the entire DAG. EntryNode - The starting token.
43 SDOperand Root, EntryNode;
45 // AllNodes - All of the nodes in the DAG
46 std::vector<SDNode*> AllNodes;
48 // ValueNodes - track SrcValue nodes
49 std::map<std::pair<const Value*, int>, SDNode*> ValueNodes;
52 SelectionDAG(TargetLowering &tli, MachineFunction &mf) : TLI(tli), MF(mf) {
53 EntryNode = Root = getNode(ISD::EntryToken, MVT::Other);
57 MachineFunction &getMachineFunction() const { return MF; }
58 const TargetMachine &getTarget() const;
59 TargetLowering &getTargetLoweringInfo() const { return TLI; }
61 /// viewGraph - Pop up a ghostview window with the DAG rendered using 'dot'.
66 typedef std::vector<SDNode*>::const_iterator allnodes_iterator;
67 allnodes_iterator allnodes_begin() const { return AllNodes.begin(); }
68 allnodes_iterator allnodes_end() const { return AllNodes.end(); }
70 /// getRoot - Return the root tag of the SelectionDAG.
72 const SDOperand &getRoot() const { return Root; }
74 /// getEntryNode - Return the token chain corresponding to the entry of the
76 const SDOperand &getEntryNode() const { return EntryNode; }
78 /// setRoot - Set the current root tag of the SelectionDAG.
80 const SDOperand &setRoot(SDOperand N) { return Root = N; }
82 /// Legalize - This transforms the SelectionDAG into a SelectionDAG that is
83 /// compatible with the target instruction selector, as indicated by the
84 /// TargetLowering object.
86 /// Note that this is an involved process that may invalidate pointers into
90 /// RemoveDeadNodes - This method deletes all unreachable nodes in the
91 /// SelectionDAG, including nodes (like loads) that have uses of their token
92 /// chain but no other uses and no side effect. If a node is passed in as an
93 /// argument, it is used as the seed for node deletion.
94 void RemoveDeadNodes(SDNode *N = 0);
96 SDOperand getConstant(uint64_t Val, MVT::ValueType VT);
97 SDOperand getTargetConstant(uint64_t Val, MVT::ValueType VT);
98 SDOperand getConstantFP(double Val, MVT::ValueType VT);
99 SDOperand getGlobalAddress(const GlobalValue *GV, MVT::ValueType VT);
100 SDOperand getTargetGlobalAddress(const GlobalValue *GV, MVT::ValueType VT);
101 SDOperand getFrameIndex(int FI, MVT::ValueType VT);
102 SDOperand getTargetFrameIndex(int FI, MVT::ValueType VT);
103 SDOperand getConstantPool(unsigned CPIdx, MVT::ValueType VT);
104 SDOperand getTargetConstantPool(unsigned CPIdx, MVT::ValueType VT);
105 SDOperand getBasicBlock(MachineBasicBlock *MBB);
106 SDOperand getExternalSymbol(const char *Sym, MVT::ValueType VT);
107 SDOperand getValueType(MVT::ValueType);
108 SDOperand getRegister(unsigned Reg, MVT::ValueType VT);
110 SDOperand getCopyToReg(SDOperand Chain, unsigned Reg, SDOperand N) {
111 return getNode(ISD::CopyToReg, MVT::Other, Chain,
112 getRegister(Reg, N.getValueType()), N);
115 SDOperand getCopyFromReg(SDOperand Chain, unsigned Reg, MVT::ValueType VT) {
116 std::vector<MVT::ValueType> ResultTys;
117 ResultTys.push_back(VT);
118 ResultTys.push_back(MVT::Other);
119 std::vector<SDOperand> Ops;
120 Ops.push_back(Chain);
121 Ops.push_back(getRegister(Reg, VT));
122 return getNode(ISD::CopyFromReg, ResultTys, Ops);
125 SDOperand getImplicitDef(SDOperand Chain, unsigned Reg, MVT::ValueType VT) {
126 return getNode(ISD::ImplicitDef, MVT::Other, Chain, getRegister(Reg, VT));
129 /// getCall - Note that this destroys the vector of RetVals passed in.
131 SDNode *getCall(std::vector<MVT::ValueType> &RetVals, SDOperand Chain,
132 SDOperand Callee, bool isTailCall = false) {
133 SDNode *NN = new SDNode(isTailCall ? ISD::TAILCALL : ISD::CALL, Chain,
135 NN->setValueTypes(RetVals);
136 AllNodes.push_back(NN);
140 /// getCall - This is identical to the one above, and should be used for calls
141 /// where arguments are passed in physical registers. This destroys the
142 /// RetVals and ArgsInRegs vectors.
143 SDNode *getCall(std::vector<MVT::ValueType> &RetVals, SDOperand Chain,
144 SDOperand Callee, std::vector<SDOperand> &ArgsInRegs,
145 bool isTailCall = false) {
146 ArgsInRegs.insert(ArgsInRegs.begin(), Callee);
147 ArgsInRegs.insert(ArgsInRegs.begin(), Chain);
148 SDNode *NN = new SDNode(isTailCall ? ISD::TAILCALL : ISD::CALL, ArgsInRegs);
149 NN->setValueTypes(RetVals);
150 AllNodes.push_back(NN);
154 SDOperand getCondCode(ISD::CondCode Cond);
156 /// getZeroExtendInReg - Return the expression required to zero extend the Op
157 /// value assuming it was the smaller SrcTy value.
158 SDOperand getZeroExtendInReg(SDOperand Op, MVT::ValueType SrcTy);
160 /// getNode - Gets or creates the specified node.
162 SDOperand getNode(unsigned Opcode, MVT::ValueType VT);
163 SDOperand getNode(unsigned Opcode, MVT::ValueType VT, SDOperand N);
164 SDOperand getNode(unsigned Opcode, MVT::ValueType VT,
165 SDOperand N1, SDOperand N2);
166 SDOperand getNode(unsigned Opcode, MVT::ValueType VT,
167 SDOperand N1, SDOperand N2, SDOperand N3);
168 SDOperand getNode(unsigned Opcode, MVT::ValueType VT,
169 SDOperand N1, SDOperand N2, SDOperand N3, SDOperand N4);
170 SDOperand getNode(unsigned Opcode, MVT::ValueType VT,
171 SDOperand N1, SDOperand N2, SDOperand N3, SDOperand N4,
173 SDOperand getNode(unsigned Opcode, MVT::ValueType VT,
174 std::vector<SDOperand> &Children);
175 SDOperand getNode(unsigned Opcode, std::vector<MVT::ValueType> &ResultTys,
176 std::vector<SDOperand> &Ops);
178 /// getSetCC - Helper function to make it easier to build SetCC's if you just
179 /// have an ISD::CondCode instead of an SDOperand.
181 SDOperand getSetCC(MVT::ValueType VT, SDOperand LHS, SDOperand RHS,
182 ISD::CondCode Cond) {
183 return getNode(ISD::SETCC, VT, LHS, RHS, getCondCode(Cond));
186 /// getSelectCC - Helper function to make it easier to build SelectCC's if you
187 /// just have an ISD::CondCode instead of an SDOperand.
189 SDOperand getSelectCC(SDOperand LHS, SDOperand RHS,
190 SDOperand True, SDOperand False, ISD::CondCode Cond) {
191 MVT::ValueType VT = True.getValueType();
192 return getNode(ISD::SELECT_CC, VT, LHS, RHS, True, False,getCondCode(Cond));
195 /// getBR2Way_CC - Helper function to make it easier to build BRTWOWAY_CC
198 SDOperand getBR2Way_CC(SDOperand Chain, SDOperand CCNode, SDOperand LHS,
199 SDOperand RHS, SDOperand True, SDOperand False) {
200 std::vector<SDOperand> Ops;
201 Ops.push_back(Chain);
202 Ops.push_back(CCNode);
206 Ops.push_back(False);
207 return getNode(ISD::BRTWOWAY_CC, MVT::Other, Ops);
210 /// getLoad - Loads are not normal binary operators: their result type is not
211 /// determined by their operands, and they produce a value AND a token chain.
213 SDOperand getLoad(MVT::ValueType VT, SDOperand Chain, SDOperand Ptr,
215 SDOperand getExtLoad(unsigned Opcode, MVT::ValueType VT, SDOperand Chain,
216 SDOperand Ptr, SDOperand SV, MVT::ValueType EVT);
218 // getSrcValue - construct a node to track a Value* through the backend
219 SDOperand getSrcValue(const Value* I, int offset = 0);
222 /// SelectNodeTo - These are used for target selectors to *mutate* the
223 /// specified node to have the specified return type, Target opcode, and
224 /// operands. Note that target opcodes are stored as
225 /// ISD::BUILTIN_OP_END+TargetOpcode in the node opcode field.
226 void SelectNodeTo(SDNode *N, MVT::ValueType VT, unsigned TargetOpc);
227 void SelectNodeTo(SDNode *N, MVT::ValueType VT, unsigned TargetOpc,
229 void SelectNodeTo(SDNode *N, MVT::ValueType VT, unsigned TargetOpc,
230 SDOperand Op1, SDOperand Op2);
231 void SelectNodeTo(SDNode *N, MVT::ValueType VT, unsigned TargetOpc,
232 SDOperand Op1, SDOperand Op2, SDOperand Op3);
233 void SelectNodeTo(SDNode *N, MVT::ValueType VT, unsigned TargetOpc,
234 SDOperand Op1, SDOperand Op2, SDOperand Op3, SDOperand Op4);
235 void SelectNodeTo(SDNode *N, MVT::ValueType VT, unsigned TargetOpc,
236 SDOperand Op1, SDOperand Op2, SDOperand Op3, SDOperand Op4,
238 void SelectNodeTo(SDNode *N, MVT::ValueType VT1, MVT::ValueType VT2,
239 unsigned TargetOpc, SDOperand Op1, SDOperand Op2);
240 void SelectNodeTo(SDNode *N, MVT::ValueType VT1, MVT::ValueType VT2,
241 unsigned TargetOpc, SDOperand Op1, SDOperand Op2,
244 SDOperand getTargetNode(unsigned Opcode, MVT::ValueType VT,
246 return getNode(ISD::BUILTIN_OP_END+Opcode, VT, Op1);
248 SDOperand getTargetNode(unsigned Opcode, MVT::ValueType VT,
249 SDOperand Op1, SDOperand Op2) {
250 return getNode(ISD::BUILTIN_OP_END+Opcode, VT, Op1, Op2);
252 SDOperand getTargetNode(unsigned Opcode, MVT::ValueType VT1,
253 MVT::ValueType VT2, SDOperand Op1, SDOperand Op2) {
254 std::vector<MVT::ValueType> ResultTys;
255 ResultTys.push_back(VT1);
256 ResultTys.push_back(VT2);
257 std::vector<SDOperand> Ops;
260 return getNode(ISD::BUILTIN_OP_END+Opcode, ResultTys, Ops);
262 SDOperand getTargetNode(unsigned Opcode, MVT::ValueType VT,
263 SDOperand Op1, SDOperand Op2, SDOperand Op3) {
264 return getNode(ISD::BUILTIN_OP_END+Opcode, VT, Op1, Op2, Op3);
266 SDOperand getTargetNode(unsigned Opcode, MVT::ValueType VT,
267 SDOperand Op1, SDOperand Op2, SDOperand Op3,
269 return getNode(ISD::BUILTIN_OP_END+Opcode, VT, Op1, Op2, Op3, Op4);
271 SDOperand getTargetNode(unsigned Opcode, MVT::ValueType VT,
272 SDOperand Op1, SDOperand Op2, SDOperand Op3,
273 SDOperand Op4, SDOperand Op5) {
274 return getNode(ISD::BUILTIN_OP_END+Opcode, VT, Op1, Op2, Op3, Op4, Op5);
276 SDOperand getTargetNode(unsigned Opcode, MVT::ValueType VT,
277 std::vector<SDOperand> &Ops) {
278 return getNode(ISD::BUILTIN_OP_END+Opcode, VT, Ops);
281 /// ReplaceAllUsesWith - Modify anything using 'From' to use 'To' instead.
282 /// This can cause recursive merging of nodes in the DAG.
284 void ReplaceAllUsesWith(SDNode *From, SDNode *To);
285 void ReplaceAllUsesWith(SDNode *From, const std::vector<SDOperand> &To);
290 void RemoveNodeFromCSEMaps(SDNode *N);
291 SDNode *AddNonLeafNodeToCSEMaps(SDNode *N);
292 void DeleteNodeIfDead(SDNode *N, void *NodeSet);
294 /// SimplifySetCC - Try to simplify a setcc built with the specified operands
295 /// and cc. If unable to simplify it, return a null SDOperand.
296 SDOperand SimplifySetCC(MVT::ValueType VT, SDOperand N1,
297 SDOperand N2, ISD::CondCode Cond);
299 /// SimplifySelectCC - Try to simplify a select_cc built with the specified
300 /// operands and cc. This can be used to simplify both the select_cc node,
301 /// and a select node whose first operand is a setcc.
302 SDOperand SimplifySelectCC(SDOperand N1, SDOperand N2, SDOperand N3,
303 SDOperand N4, ISD::CondCode CC);
305 // Maps to auto-CSE operations.
306 std::map<std::pair<unsigned, std::pair<SDOperand, MVT::ValueType> >,
308 std::map<std::pair<unsigned, std::pair<SDOperand, SDOperand> >,
311 std::vector<RegisterSDNode*> RegNodes;
312 std::vector<CondCodeSDNode*> CondCodeNodes;
314 std::map<std::pair<SDOperand, std::pair<SDOperand, MVT::ValueType> >,
317 std::map<const GlobalValue*, SDNode*> GlobalValues;
318 std::map<const GlobalValue*, SDNode*> TargetGlobalValues;
319 std::map<std::pair<uint64_t, MVT::ValueType>, SDNode*> Constants;
320 std::map<std::pair<uint64_t, MVT::ValueType>, SDNode*> TargetConstants;
321 std::map<std::pair<uint64_t, MVT::ValueType>, SDNode*> ConstantFPs;
322 std::map<int, SDNode*> FrameIndices, TargetFrameIndices;
323 std::map<unsigned, SDNode*> ConstantPoolIndices, TargetConstantPoolIndices;
324 std::map<MachineBasicBlock *, SDNode*> BBNodes;
325 std::vector<SDNode*> ValueTypeNodes;
326 std::map<std::string, SDNode*> ExternalSymbols;
327 std::map<std::pair<unsigned,
328 std::pair<MVT::ValueType, std::vector<SDOperand> > >,
329 SDNode*> OneResultNodes;
330 std::map<std::pair<unsigned,
331 std::pair<std::vector<MVT::ValueType>,
332 std::vector<SDOperand> > >,
333 SDNode*> ArbitraryNodes;
336 template <> struct GraphTraits<SelectionDAG*> : public GraphTraits<SDNode*> {
337 typedef SelectionDAG::allnodes_iterator nodes_iterator;
338 static nodes_iterator nodes_begin(SelectionDAG *G) {
339 return G->allnodes_begin();
341 static nodes_iterator nodes_end(SelectionDAG *G) {
342 return G->allnodes_end();