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 getFrameIndex(int FI, MVT::ValueType VT);
101 SDOperand getConstantPool(unsigned CPIdx, MVT::ValueType VT);
102 SDOperand getBasicBlock(MachineBasicBlock *MBB);
103 SDOperand getExternalSymbol(const char *Sym, MVT::ValueType VT);
104 SDOperand getValueType(MVT::ValueType);
105 SDOperand getRegister(unsigned Reg, MVT::ValueType VT);
107 SDOperand getCopyToReg(SDOperand Chain, unsigned Reg, SDOperand N) {
108 return getNode(ISD::CopyToReg, MVT::Other, Chain,
109 getRegister(Reg, N.getValueType()), N);
112 SDOperand getCopyFromReg(SDOperand Chain, unsigned Reg, MVT::ValueType VT) {
113 std::vector<MVT::ValueType> ResultTys;
114 ResultTys.push_back(VT);
115 ResultTys.push_back(MVT::Other);
116 std::vector<SDOperand> Ops;
117 Ops.push_back(Chain);
118 Ops.push_back(getRegister(Reg, VT));
119 return getNode(ISD::CopyFromReg, ResultTys, Ops);
122 SDOperand getImplicitDef(SDOperand Chain, unsigned Reg, MVT::ValueType VT) {
123 return getNode(ISD::ImplicitDef, MVT::Other, Chain, getRegister(Reg, VT));
126 /// getCall - Note that this destroys the vector of RetVals passed in.
128 SDNode *getCall(std::vector<MVT::ValueType> &RetVals, SDOperand Chain,
129 SDOperand Callee, bool isTailCall = false) {
130 SDNode *NN = new SDNode(isTailCall ? ISD::TAILCALL : ISD::CALL, Chain,
132 NN->setValueTypes(RetVals);
133 AllNodes.push_back(NN);
137 /// getCall - This is identical to the one above, and should be used for calls
138 /// where arguments are passed in physical registers. This destroys the
139 /// RetVals and ArgsInRegs vectors.
140 SDNode *getCall(std::vector<MVT::ValueType> &RetVals, SDOperand Chain,
141 SDOperand Callee, std::vector<SDOperand> &ArgsInRegs,
142 bool isTailCall = false) {
143 ArgsInRegs.insert(ArgsInRegs.begin(), Callee);
144 ArgsInRegs.insert(ArgsInRegs.begin(), Chain);
145 SDNode *NN = new SDNode(isTailCall ? ISD::TAILCALL : ISD::CALL, ArgsInRegs);
146 NN->setValueTypes(RetVals);
147 AllNodes.push_back(NN);
151 SDOperand getCondCode(ISD::CondCode Cond);
153 /// getZeroExtendInReg - Return the expression required to zero extend the Op
154 /// value assuming it was the smaller SrcTy value.
155 SDOperand getZeroExtendInReg(SDOperand Op, MVT::ValueType SrcTy);
157 /// getNode - Gets or creates the specified node.
159 SDOperand getNode(unsigned Opcode, MVT::ValueType VT);
160 SDOperand getNode(unsigned Opcode, MVT::ValueType VT, SDOperand N);
161 SDOperand getNode(unsigned Opcode, MVT::ValueType VT,
162 SDOperand N1, SDOperand N2);
163 SDOperand getNode(unsigned Opcode, MVT::ValueType VT,
164 SDOperand N1, SDOperand N2, SDOperand N3);
165 SDOperand getNode(unsigned Opcode, MVT::ValueType VT,
166 SDOperand N1, SDOperand N2, SDOperand N3, SDOperand N4);
167 SDOperand getNode(unsigned Opcode, MVT::ValueType VT,
168 SDOperand N1, SDOperand N2, SDOperand N3, SDOperand N4,
170 SDOperand getNode(unsigned Opcode, MVT::ValueType VT,
171 std::vector<SDOperand> &Children);
172 SDOperand getNode(unsigned Opcode, std::vector<MVT::ValueType> &ResultTys,
173 std::vector<SDOperand> &Ops);
175 /// getSetCC - Helper function to make it easier to build SetCC's if you just
176 /// have an ISD::CondCode instead of an SDOperand.
178 SDOperand getSetCC(MVT::ValueType VT, SDOperand LHS, SDOperand RHS,
179 ISD::CondCode Cond) {
180 return getNode(ISD::SETCC, VT, LHS, RHS, getCondCode(Cond));
183 /// getSelectCC - Helper function to make it easier to build SelectCC's if you
184 /// just have an ISD::CondCode instead of an SDOperand.
186 SDOperand getSelectCC(SDOperand LHS, SDOperand RHS,
187 SDOperand True, SDOperand False, ISD::CondCode Cond) {
188 MVT::ValueType VT = True.getValueType();
189 return getNode(ISD::SELECT_CC, VT, LHS, RHS, True, False,getCondCode(Cond));
192 /// getBR2Way_CC - Helper function to make it easier to build BRTWOWAY_CC
195 SDOperand getBR2Way_CC(SDOperand Chain, SDOperand CCNode, SDOperand LHS,
196 SDOperand RHS, SDOperand True, SDOperand False) {
197 std::vector<SDOperand> Ops;
198 Ops.push_back(Chain);
199 Ops.push_back(CCNode);
203 Ops.push_back(False);
204 return getNode(ISD::BRTWOWAY_CC, MVT::Other, Ops);
207 /// getLoad - Loads are not normal binary operators: their result type is not
208 /// determined by their operands, and they produce a value AND a token chain.
210 SDOperand getLoad(MVT::ValueType VT, SDOperand Chain, SDOperand Ptr,
212 SDOperand getExtLoad(unsigned Opcode, MVT::ValueType VT, SDOperand Chain,
213 SDOperand Ptr, SDOperand SV, MVT::ValueType EVT);
215 // getSrcValue - construct a node to track a Value* through the backend
216 SDOperand getSrcValue(const Value* I, int offset = 0);
219 /// SelectNodeTo - These are used for target selectors to *mutate* the
220 /// specified node to have the specified return type, Target opcode, and
221 /// operands. Note that target opcodes are stored as
222 /// ISD::BUILTIN_OP_END+TargetOpcode in the node opcode field.
223 void SelectNodeTo(SDNode *N, MVT::ValueType VT, unsigned TargetOpc,
225 void SelectNodeTo(SDNode *N, MVT::ValueType VT, unsigned TargetOpc,
226 SDOperand Op1, SDOperand Op2);
227 void SelectNodeTo(SDNode *N, MVT::ValueType VT, unsigned TargetOpc,
228 SDOperand Op1, SDOperand Op2, SDOperand Op3);
230 SDOperand getTargetNode(unsigned Opcode, MVT::ValueType VT,
232 return getNode(ISD::BUILTIN_OP_END+Opcode, VT, Op1);
234 SDOperand getTargetNode(unsigned Opcode, MVT::ValueType VT,
235 SDOperand Op1, SDOperand Op2) {
236 return getNode(ISD::BUILTIN_OP_END+Opcode, VT, Op1, Op2);
238 SDOperand getTargetNode(unsigned Opcode, MVT::ValueType VT,
239 SDOperand Op1, SDOperand Op2, SDOperand Op3) {
240 return getNode(ISD::BUILTIN_OP_END+Opcode, VT, Op1, Op2, Op3);
243 /// ReplaceAllUsesWith - Modify anything using 'From' to use 'To' instead.
244 /// This can cause recursive merging of nodes in the DAG.
246 void ReplaceAllUsesWith(SDNode *From, SDNode *To);
251 void RemoveNodeFromCSEMaps(SDNode *N);
252 SDNode *AddNonLeafNodeToCSEMaps(SDNode *N);
253 void DeleteNodeIfDead(SDNode *N, void *NodeSet);
255 /// SimplifySetCC - Try to simplify a setcc built with the specified operands
256 /// and cc. If unable to simplify it, return a null SDOperand.
257 SDOperand SimplifySetCC(MVT::ValueType VT, SDOperand N1,
258 SDOperand N2, ISD::CondCode Cond);
260 /// SimplifySelectCC - Try to simplify a select_cc built with the specified
261 /// operands and cc. This can be used to simplify both the select_cc node,
262 /// and a select node whose first operand is a setcc.
263 SDOperand SimplifySelectCC(SDOperand N1, SDOperand N2, SDOperand N3,
264 SDOperand N4, ISD::CondCode CC);
266 // Maps to auto-CSE operations.
267 std::map<std::pair<unsigned, std::pair<SDOperand, MVT::ValueType> >,
269 std::map<std::pair<unsigned, std::pair<SDOperand, SDOperand> >,
272 std::vector<RegisterSDNode*> RegNodes;
273 std::vector<CondCodeSDNode*> CondCodeNodes;
275 std::map<std::pair<SDOperand, std::pair<SDOperand, MVT::ValueType> >,
278 std::map<const GlobalValue*, SDNode*> GlobalValues;
279 std::map<std::pair<uint64_t, MVT::ValueType>, SDNode*> Constants;
280 std::map<std::pair<uint64_t, MVT::ValueType>, SDNode*> TargetConstants;
281 std::map<std::pair<uint64_t, MVT::ValueType>, SDNode*> ConstantFPs;
282 std::map<int, SDNode*> FrameIndices;
283 std::map<unsigned, SDNode*> ConstantPoolIndices;
284 std::map<MachineBasicBlock *, SDNode*> BBNodes;
285 std::vector<SDNode*> ValueTypeNodes;
286 std::map<std::string, SDNode*> ExternalSymbols;
287 std::map<std::pair<unsigned,
288 std::pair<MVT::ValueType, std::vector<SDOperand> > >,
289 SDNode*> OneResultNodes;
290 std::map<std::pair<unsigned,
291 std::pair<std::vector<MVT::ValueType>,
292 std::vector<SDOperand> > >,
293 SDNode*> ArbitraryNodes;
296 template <> struct GraphTraits<SelectionDAG*> : public GraphTraits<SDNode*> {
297 typedef SelectionDAG::allnodes_iterator nodes_iterator;
298 static nodes_iterator nodes_begin(SelectionDAG *G) {
299 return G->allnodes_begin();
301 static nodes_iterator nodes_end(SelectionDAG *G) {
302 return G->allnodes_end();