LLVM API Documentation
00001 //===-- llvm/CodeGen/MachineFunction.h --------------------------*- C++ -*-===// 00002 // 00003 // The LLVM Compiler Infrastructure 00004 // 00005 // This file was developed by the LLVM research group and is distributed under 00006 // the University of Illinois Open Source License. See LICENSE.TXT for details. 00007 // 00008 //===----------------------------------------------------------------------===// 00009 // 00010 // Collect native machine code for a function. This class contains a list of 00011 // MachineBasicBlock instances that make up the current compiled function. 00012 // 00013 // This class also contains pointers to various classes which hold 00014 // target-specific information about the generated code. 00015 // 00016 //===----------------------------------------------------------------------===// 00017 00018 #ifndef LLVM_CODEGEN_MACHINEFUNCTION_H 00019 #define LLVM_CODEGEN_MACHINEFUNCTION_H 00020 00021 #include "llvm/CodeGen/MachineDebugInfo.h" 00022 #include "llvm/CodeGen/MachineBasicBlock.h" 00023 #include "llvm/Support/Annotation.h" 00024 00025 namespace llvm { 00026 00027 class Function; 00028 class TargetMachine; 00029 class SSARegMap; 00030 class MachineFrameInfo; 00031 class MachineConstantPool; 00032 00033 // ilist_traits 00034 template <> 00035 struct ilist_traits<MachineBasicBlock> { 00036 // this is only set by the MachineFunction owning the ilist 00037 friend class MachineFunction; 00038 MachineFunction* Parent; 00039 00040 public: 00041 ilist_traits<MachineBasicBlock>() : Parent(0) { } 00042 00043 static MachineBasicBlock* getPrev(MachineBasicBlock* N) { return N->Prev; } 00044 static MachineBasicBlock* getNext(MachineBasicBlock* N) { return N->Next; } 00045 00046 static const MachineBasicBlock* 00047 getPrev(const MachineBasicBlock* N) { return N->Prev; } 00048 00049 static const MachineBasicBlock* 00050 getNext(const MachineBasicBlock* N) { return N->Next; } 00051 00052 static void setPrev(MachineBasicBlock* N, MachineBasicBlock* prev) { 00053 N->Prev = prev; 00054 } 00055 static void setNext(MachineBasicBlock* N, MachineBasicBlock* next) { 00056 N->Next = next; 00057 } 00058 00059 static MachineBasicBlock* createSentinel(); 00060 static void destroySentinel(MachineBasicBlock *MBB) { delete MBB; } 00061 void addNodeToList(MachineBasicBlock* N); 00062 void removeNodeFromList(MachineBasicBlock* N); 00063 void transferNodesFromList(iplist<MachineBasicBlock, 00064 ilist_traits<MachineBasicBlock> > &toList, 00065 ilist_iterator<MachineBasicBlock> first, 00066 ilist_iterator<MachineBasicBlock> last); 00067 }; 00068 00069 /// MachineFunctionInfo - This class can be derived from and used by targets to 00070 /// hold private target-specific information for each MachineFunction. Objects 00071 /// of type are accessed/created with MF::getInfo and destroyed when the 00072 /// MachineFunction is destroyed. 00073 struct MachineFunctionInfo { 00074 virtual ~MachineFunctionInfo() {}; 00075 }; 00076 00077 class MachineFunction : private Annotation { 00078 const Function *Fn; 00079 const TargetMachine &Target; 00080 00081 // List of machine basic blocks in function 00082 ilist<MachineBasicBlock> BasicBlocks; 00083 00084 // Keeping track of mapping from SSA values to registers 00085 SSARegMap *SSARegMapping; 00086 00087 // Used to keep track of target-specific per-machine function information for 00088 // the target implementation. 00089 MachineFunctionInfo *MFInfo; 00090 00091 // Keep track of objects allocated on the stack. 00092 MachineFrameInfo *FrameInfo; 00093 00094 // Keep track of constants which are spilled to memory 00095 MachineConstantPool *ConstantPool; 00096 00097 // Function-level unique numbering for MachineBasicBlocks. When a 00098 // MachineBasicBlock is inserted into a MachineFunction is it automatically 00099 // numbered and this vector keeps track of the mapping from ID's to MBB's. 00100 std::vector<MachineBasicBlock*> MBBNumbering; 00101 00102 /// UsedPhysRegs - This is a new[]'d array of bools that is computed and set 00103 /// by the register allocator, and must be kept up to date by passes that run 00104 /// after register allocation (though most don't modify this). This is used 00105 /// so that the code generator knows which callee save registers to save and 00106 /// for other target specific uses. 00107 bool *UsedPhysRegs; 00108 00109 /// LiveIns/LiveOuts - Keep track of the physical registers that are 00110 /// livein/liveout of the function. Live in values are typically arguments in 00111 /// registers, live out values are typically return values in registers. 00112 /// LiveIn values are allowed to have virtual registers associated with them, 00113 /// stored in the second element. 00114 std::vector<std::pair<unsigned, unsigned> > LiveIns; 00115 std::vector<unsigned> LiveOuts; 00116 00117 public: 00118 MachineFunction(const Function *Fn, const TargetMachine &TM); 00119 ~MachineFunction(); 00120 00121 /// getFunction - Return the LLVM function that this machine code represents 00122 /// 00123 const Function *getFunction() const { return Fn; } 00124 00125 /// getTarget - Return the target machine this machine code is compiled with 00126 /// 00127 const TargetMachine &getTarget() const { return Target; } 00128 00129 /// SSARegMap Interface... Keep track of information about each SSA virtual 00130 /// register, such as which register class it belongs to. 00131 /// 00132 SSARegMap *getSSARegMap() const { return SSARegMapping; } 00133 void clearSSARegMap(); 00134 00135 /// getFrameInfo - Return the frame info object for the current function. 00136 /// This object contains information about objects allocated on the stack 00137 /// frame of the current function in an abstract way. 00138 /// 00139 MachineFrameInfo *getFrameInfo() const { return FrameInfo; } 00140 00141 /// getConstantPool - Return the constant pool object for the current 00142 /// function. 00143 /// 00144 MachineConstantPool *getConstantPool() const { return ConstantPool; } 00145 00146 /// MachineFunctionInfo - Keep track of various per-function pieces of 00147 /// information for backends that would like to do so. 00148 /// 00149 template<typename Ty> 00150 Ty *getInfo() { 00151 if (!MFInfo) MFInfo = new Ty(*this); 00152 00153 assert((void*)dynamic_cast<Ty*>(MFInfo) == (void*)MFInfo && 00154 "Invalid concrete type or multiple inheritence for getInfo"); 00155 return static_cast<Ty*>(MFInfo); 00156 } 00157 00158 /// setUsedPhysRegs - The register allocator should call this to initialized 00159 /// the UsedPhysRegs set. This should be passed a new[]'d array with entries 00160 /// for all of the physical registers that the target supports. Each array 00161 /// entry should be set to true iff the physical register is used within the 00162 /// function. 00163 void setUsedPhysRegs(bool *UPR) { UsedPhysRegs = UPR; } 00164 00165 /// getUsedPhysregs - This returns the UsedPhysRegs array. This returns null 00166 /// before register allocation. 00167 bool *getUsedPhysregs() { return UsedPhysRegs; } 00168 const bool *getUsedPhysregs() const { return UsedPhysRegs; } 00169 00170 /// isPhysRegUsed - Return true if the specified register is used in this 00171 /// function. This only works after register allocation. 00172 bool isPhysRegUsed(unsigned Reg) { return UsedPhysRegs[Reg]; } 00173 00174 /// changePhyRegUsed - This method allows code that runs after register 00175 /// allocation to keep the PhysRegsUsed array up-to-date. 00176 void changePhyRegUsed(unsigned Reg, bool State) { UsedPhysRegs[Reg] = State; } 00177 00178 00179 // LiveIn/LiveOut management methods. 00180 00181 /// addLiveIn/Out - Add the specified register as a live in/out. Note that it 00182 /// is an error to add the same register to the same set more than once. 00183 void addLiveIn(unsigned Reg, unsigned vreg = 0) { 00184 LiveIns.push_back(std::make_pair(Reg, vreg)); 00185 } 00186 void addLiveOut(unsigned Reg) { LiveOuts.push_back(Reg); } 00187 00188 // Iteration support for live in/out sets. These sets are kept in sorted 00189 // order by their register number. 00190 typedef std::vector<std::pair<unsigned,unsigned> >::const_iterator 00191 livein_iterator; 00192 typedef std::vector<unsigned>::const_iterator liveout_iterator; 00193 livein_iterator livein_begin() const { return LiveIns.begin(); } 00194 livein_iterator livein_end() const { return LiveIns.end(); } 00195 bool livein_empty() const { return LiveIns.empty(); } 00196 liveout_iterator liveout_begin() const { return LiveOuts.begin(); } 00197 liveout_iterator liveout_end() const { return LiveOuts.end(); } 00198 bool liveout_empty() const { return LiveOuts.empty(); } 00199 00200 /// getBlockNumbered - MachineBasicBlocks are automatically numbered when they 00201 /// are inserted into the machine function. The block number for a machine 00202 /// basic block can be found by using the MBB::getBlockNumber method, this 00203 /// method provides the inverse mapping. 00204 /// 00205 MachineBasicBlock *getBlockNumbered(unsigned N) { 00206 assert(N < MBBNumbering.size() && "Illegal block number"); 00207 assert(MBBNumbering[N] && "Block was removed from the machine function!"); 00208 return MBBNumbering[N]; 00209 } 00210 00211 /// getLastBlock - Returns the MachineBasicBlock with the greatest number 00212 MachineBasicBlock *getLastBlock() { 00213 return MBBNumbering.back(); 00214 } 00215 const MachineBasicBlock *getLastBlock() const { 00216 return MBBNumbering.back(); 00217 } 00218 00219 /// print - Print out the MachineFunction in a format suitable for debugging 00220 /// to the specified stream. 00221 /// 00222 void print(std::ostream &OS) const; 00223 00224 /// viewCFG - This function is meant for use from the debugger. You can just 00225 /// say 'call F->viewCFG()' and a ghostview window should pop up from the 00226 /// program, displaying the CFG of the current function with the code for each 00227 /// basic block inside. This depends on there being a 'dot' and 'gv' program 00228 /// in your path. 00229 /// 00230 void viewCFG() const; 00231 00232 /// viewCFGOnly - This function is meant for use from the debugger. It works 00233 /// just like viewCFG, but it does not include the contents of basic blocks 00234 /// into the nodes, just the label. If you are only interested in the CFG 00235 /// this can make the graph smaller. 00236 /// 00237 void viewCFGOnly() const; 00238 00239 /// dump - Print the current MachineFunction to cerr, useful for debugger use. 00240 /// 00241 void dump() const; 00242 00243 /// construct - Allocate and initialize a MachineFunction for a given Function 00244 /// and Target 00245 /// 00246 static MachineFunction& construct(const Function *F, const TargetMachine &TM); 00247 00248 /// destruct - Destroy the MachineFunction corresponding to a given Function 00249 /// 00250 static void destruct(const Function *F); 00251 00252 /// get - Return a handle to a MachineFunction corresponding to the given 00253 /// Function. This should not be called before "construct()" for a given 00254 /// Function. 00255 /// 00256 static MachineFunction& get(const Function *F); 00257 00258 // Provide accessors for the MachineBasicBlock list... 00259 typedef ilist<MachineBasicBlock> BasicBlockListType; 00260 typedef BasicBlockListType::iterator iterator; 00261 typedef BasicBlockListType::const_iterator const_iterator; 00262 typedef std::reverse_iterator<const_iterator> const_reverse_iterator; 00263 typedef std::reverse_iterator<iterator> reverse_iterator; 00264 00265 // Provide accessors for basic blocks... 00266 const BasicBlockListType &getBasicBlockList() const { return BasicBlocks; } 00267 BasicBlockListType &getBasicBlockList() { return BasicBlocks; } 00268 00269 //===--------------------------------------------------------------------===// 00270 // BasicBlock iterator forwarding functions 00271 // 00272 iterator begin() { return BasicBlocks.begin(); } 00273 const_iterator begin() const { return BasicBlocks.begin(); } 00274 iterator end () { return BasicBlocks.end(); } 00275 const_iterator end () const { return BasicBlocks.end(); } 00276 00277 reverse_iterator rbegin() { return BasicBlocks.rbegin(); } 00278 const_reverse_iterator rbegin() const { return BasicBlocks.rbegin(); } 00279 reverse_iterator rend () { return BasicBlocks.rend(); } 00280 const_reverse_iterator rend () const { return BasicBlocks.rend(); } 00281 00282 unsigned size() const { return BasicBlocks.size(); } 00283 bool empty() const { return BasicBlocks.empty(); } 00284 const MachineBasicBlock &front() const { return BasicBlocks.front(); } 00285 MachineBasicBlock &front() { return BasicBlocks.front(); } 00286 const MachineBasicBlock & back() const { return BasicBlocks.back(); } 00287 MachineBasicBlock & back() { return BasicBlocks.back(); } 00288 00289 //===--------------------------------------------------------------------===// 00290 // Internal functions used to automatically number MachineBasicBlocks 00291 // 00292 00293 /// getNextMBBNumber - Returns the next unique number to be assigned 00294 /// to a MachineBasicBlock in this MachineFunction. 00295 /// 00296 unsigned addToMBBNumbering(MachineBasicBlock *MBB) { 00297 MBBNumbering.push_back(MBB); 00298 return MBBNumbering.size()-1; 00299 } 00300 00301 /// removeFromMBBNumbering - Remove the specific machine basic block from our 00302 /// tracker, this is only really to be used by the MachineBasicBlock 00303 /// implementation. 00304 void removeFromMBBNumbering(unsigned N) { 00305 assert(N < MBBNumbering.size() && "Illegal basic block #"); 00306 MBBNumbering[N] = 0; 00307 } 00308 }; 00309 00310 //===--------------------------------------------------------------------===// 00311 // GraphTraits specializations for function basic block graphs (CFGs) 00312 //===--------------------------------------------------------------------===// 00313 00314 // Provide specializations of GraphTraits to be able to treat a 00315 // machine function as a graph of machine basic blocks... these are 00316 // the same as the machine basic block iterators, except that the root 00317 // node is implicitly the first node of the function. 00318 // 00319 template <> struct GraphTraits<MachineFunction*> : 00320 public GraphTraits<MachineBasicBlock*> { 00321 static NodeType *getEntryNode(MachineFunction *F) { 00322 return &F->front(); 00323 } 00324 00325 // nodes_iterator/begin/end - Allow iteration over all nodes in the graph 00326 typedef MachineFunction::iterator nodes_iterator; 00327 static nodes_iterator nodes_begin(MachineFunction *F) { return F->begin(); } 00328 static nodes_iterator nodes_end (MachineFunction *F) { return F->end(); } 00329 }; 00330 template <> struct GraphTraits<const MachineFunction*> : 00331 public GraphTraits<const MachineBasicBlock*> { 00332 static NodeType *getEntryNode(const MachineFunction *F) { 00333 return &F->front(); 00334 } 00335 00336 // nodes_iterator/begin/end - Allow iteration over all nodes in the graph 00337 typedef MachineFunction::const_iterator nodes_iterator; 00338 static nodes_iterator nodes_begin(const MachineFunction *F) { return F->begin(); } 00339 static nodes_iterator nodes_end (const MachineFunction *F) { return F->end(); } 00340 }; 00341 00342 00343 // Provide specializations of GraphTraits to be able to treat a function as a 00344 // graph of basic blocks... and to walk it in inverse order. Inverse order for 00345 // a function is considered to be when traversing the predecessor edges of a BB 00346 // instead of the successor edges. 00347 // 00348 template <> struct GraphTraits<Inverse<MachineFunction*> > : 00349 public GraphTraits<Inverse<MachineBasicBlock*> > { 00350 static NodeType *getEntryNode(Inverse<MachineFunction*> G) { 00351 return &G.Graph->front(); 00352 } 00353 }; 00354 template <> struct GraphTraits<Inverse<const MachineFunction*> > : 00355 public GraphTraits<Inverse<const MachineBasicBlock*> > { 00356 static NodeType *getEntryNode(Inverse<const MachineFunction *> G) { 00357 return &G.Graph->front(); 00358 } 00359 }; 00360 00361 } // End llvm namespace 00362 00363 #endif