1 //===-- llvm/CodeGen/MachineFunction.h --------------------------*- C++ -*-===// 2 // 3 // The LLVM Compiler Infrastructure 4 // 5 // This file is distributed under the University of Illinois Open Source 6 // License. See LICENSE.TXT for details. 7 // 8 //===----------------------------------------------------------------------===// 9 // 10 // Collect native machine code for a function. This class contains a list of 11 // MachineBasicBlock instances that make up the current compiled function. 12 // 13 // This class also contains pointers to various classes which hold 14 // target-specific information about the generated code. 15 // 16 //===----------------------------------------------------------------------===// 17 18 #ifndef LLVM_CODEGEN_MACHINEFUNCTION_H 19 #define LLVM_CODEGEN_MACHINEFUNCTION_H 20 21 #include "llvm/CodeGen/MachineBasicBlock.h" 22 #include "llvm/ADT/ilist.h" 23 #include "llvm/Support/DebugLoc.h" 24 #include "llvm/Support/Allocator.h" 25 #include "llvm/Support/Recycler.h" 26 27 namespace llvm { 28 29 class Value; 30 class Function; 31 class GCModuleInfo; 32 class MachineRegisterInfo; 33 class MachineFrameInfo; 34 class MachineConstantPool; 35 class MachineJumpTableInfo; 36 class MachineModuleInfo; 37 class MCContext; 38 class Pass; 39 class TargetMachine; 40 class TargetRegisterClass; 41 struct MachinePointerInfo; 42 43 template <> 44 struct ilist_traits<MachineBasicBlock> 45 : public ilist_default_traits<MachineBasicBlock> { 46 mutable ilist_half_node<MachineBasicBlock> Sentinel; 47 public: 48 MachineBasicBlock *createSentinel() const { 49 return static_cast<MachineBasicBlock*>(&Sentinel); 50 } 51 void destroySentinel(MachineBasicBlock *) const {} 52 53 MachineBasicBlock *provideInitialHead() const { return createSentinel(); } 54 MachineBasicBlock *ensureHead(MachineBasicBlock*) const { 55 return createSentinel(); 56 } 57 static void noteHead(MachineBasicBlock*, MachineBasicBlock*) {} 58 59 void addNodeToList(MachineBasicBlock* MBB); 60 void removeNodeFromList(MachineBasicBlock* MBB); 61 void deleteNode(MachineBasicBlock *MBB); 62 private: 63 void createNode(const MachineBasicBlock &); 64 }; 65 66 /// MachineFunctionInfo - This class can be derived from and used by targets to 67 /// hold private target-specific information for each MachineFunction. Objects 68 /// of type are accessed/created with MF::getInfo and destroyed when the 69 /// MachineFunction is destroyed. 70 struct MachineFunctionInfo { 71 virtual ~MachineFunctionInfo(); 72 }; 73 74 class MachineFunction { 75 const Function *Fn; 76 const TargetMachine &Target; 77 MCContext &Ctx; 78 MachineModuleInfo &MMI; 79 GCModuleInfo *GMI; 80 81 // RegInfo - Information about each register in use in the function. 82 MachineRegisterInfo *RegInfo; 83 84 // Used to keep track of target-specific per-machine function information for 85 // the target implementation. 86 MachineFunctionInfo *MFInfo; 87 88 // Keep track of objects allocated on the stack. 89 MachineFrameInfo *FrameInfo; 90 91 // Keep track of constants which are spilled to memory 92 MachineConstantPool *ConstantPool; 93 94 // Keep track of jump tables for switch instructions 95 MachineJumpTableInfo *JumpTableInfo; 96 97 // Function-level unique numbering for MachineBasicBlocks. When a 98 // MachineBasicBlock is inserted into a MachineFunction is it automatically 99 // numbered and this vector keeps track of the mapping from ID's to MBB's. 100 std::vector<MachineBasicBlock*> MBBNumbering; 101 102 // Pool-allocate MachineFunction-lifetime and IR objects. 103 BumpPtrAllocator Allocator; 104 105 // Allocation management for instructions in function. 106 Recycler<MachineInstr> InstructionRecycler; 107 108 // Allocation management for basic blocks in function. 109 Recycler<MachineBasicBlock> BasicBlockRecycler; 110 111 // List of machine basic blocks in function 112 typedef ilist<MachineBasicBlock> BasicBlockListType; 113 BasicBlockListType BasicBlocks; 114 115 /// FunctionNumber - This provides a unique ID for each function emitted in 116 /// this translation unit. 117 /// 118 unsigned FunctionNumber; 119 120 /// Alignment - The alignment of the function. 121 unsigned Alignment; 122 123 /// ExposesReturnsTwice - True if the function calls setjmp or related 124 /// functions with attribute "returns twice", but doesn't have 125 /// the attribute itself. 126 /// This is used to limit optimizations which cannot reason 127 /// about the control flow of such functions. 128 bool ExposesReturnsTwice; 129 130 MachineFunction(const MachineFunction &); // DO NOT IMPLEMENT 131 void operator=(const MachineFunction&); // DO NOT IMPLEMENT 132 public: 133 MachineFunction(const Function *Fn, const TargetMachine &TM, 134 unsigned FunctionNum, MachineModuleInfo &MMI, 135 GCModuleInfo* GMI); 136 ~MachineFunction(); 137 138 MachineModuleInfo &getMMI() const { return MMI; } 139 GCModuleInfo *getGMI() const { return GMI; } 140 MCContext &getContext() const { return Ctx; } 141 142 /// getFunction - Return the LLVM function that this machine code represents 143 /// 144 const Function *getFunction() const { return Fn; } 145 146 /// getFunctionNumber - Return a unique ID for the current function. 147 /// 148 unsigned getFunctionNumber() const { return FunctionNumber; } 149 150 /// getTarget - Return the target machine this machine code is compiled with 151 /// 152 const TargetMachine &getTarget() const { return Target; } 153 154 /// getRegInfo - Return information about the registers currently in use. 155 /// 156 MachineRegisterInfo &getRegInfo() { return *RegInfo; } 157 const MachineRegisterInfo &getRegInfo() const { return *RegInfo; } 158 159 /// getFrameInfo - Return the frame info object for the current function. 160 /// This object contains information about objects allocated on the stack 161 /// frame of the current function in an abstract way. 162 /// 163 MachineFrameInfo *getFrameInfo() { return FrameInfo; } 164 const MachineFrameInfo *getFrameInfo() const { return FrameInfo; } 165 166 /// getJumpTableInfo - Return the jump table info object for the current 167 /// function. This object contains information about jump tables in the 168 /// current function. If the current function has no jump tables, this will 169 /// return null. 170 const MachineJumpTableInfo *getJumpTableInfo() const { return JumpTableInfo; } 171 MachineJumpTableInfo *getJumpTableInfo() { return JumpTableInfo; } 172 173 /// getOrCreateJumpTableInfo - Get the JumpTableInfo for this function, if it 174 /// does already exist, allocate one. 175 MachineJumpTableInfo *getOrCreateJumpTableInfo(unsigned JTEntryKind); 176 177 178 /// getConstantPool - Return the constant pool object for the current 179 /// function. 180 /// 181 MachineConstantPool *getConstantPool() { return ConstantPool; } 182 const MachineConstantPool *getConstantPool() const { return ConstantPool; } 183 184 /// getAlignment - Return the alignment (log2, not bytes) of the function. 185 /// 186 unsigned getAlignment() const { return Alignment; } 187 188 /// setAlignment - Set the alignment (log2, not bytes) of the function. 189 /// 190 void setAlignment(unsigned A) { Alignment = A; } 191 192 /// EnsureAlignment - Make sure the function is at least 1 << A bytes aligned. 193 void EnsureAlignment(unsigned A) { 194 if (Alignment < A) Alignment = A; 195 } 196 197 /// exposesReturnsTwice - Returns true if the function calls setjmp or 198 /// any other similar functions with attribute "returns twice" without 199 /// having the attribute itself. 200 bool exposesReturnsTwice() const { 201 return ExposesReturnsTwice; 202 } 203 204 /// setCallsSetJmp - Set a flag that indicates if there's a call to 205 /// a "returns twice" function. 206 void setExposesReturnsTwice(bool B) { 207 ExposesReturnsTwice = B; 208 } 209 210 /// getInfo - Keep track of various per-function pieces of information for 211 /// backends that would like to do so. 212 /// 213 template<typename Ty> 214 Ty *getInfo() { 215 if (!MFInfo) { 216 // This should be just `new (Allocator.Allocate<Ty>()) Ty(*this)', but 217 // that apparently breaks GCC 3.3. 218 Ty *Loc = static_cast<Ty*>(Allocator.Allocate(sizeof(Ty), 219 AlignOf<Ty>::Alignment)); 220 MFInfo = new (Loc) Ty(*this); 221 } 222 return static_cast<Ty*>(MFInfo); 223 } 224 225 template<typename Ty> 226 const Ty *getInfo() const { 227 return const_cast<MachineFunction*>(this)->getInfo<Ty>(); 228 } 229 230 /// getBlockNumbered - MachineBasicBlocks are automatically numbered when they 231 /// are inserted into the machine function. The block number for a machine 232 /// basic block can be found by using the MBB::getBlockNumber method, this 233 /// method provides the inverse mapping. 234 /// 235 MachineBasicBlock *getBlockNumbered(unsigned N) const { 236 assert(N < MBBNumbering.size() && "Illegal block number"); 237 assert(MBBNumbering[N] && "Block was removed from the machine function!"); 238 return MBBNumbering[N]; 239 } 240 241 /// getNumBlockIDs - Return the number of MBB ID's allocated. 242 /// 243 unsigned getNumBlockIDs() const { return (unsigned)MBBNumbering.size(); } 244 245 /// RenumberBlocks - This discards all of the MachineBasicBlock numbers and 246 /// recomputes them. This guarantees that the MBB numbers are sequential, 247 /// dense, and match the ordering of the blocks within the function. If a 248 /// specific MachineBasicBlock is specified, only that block and those after 249 /// it are renumbered. 250 void RenumberBlocks(MachineBasicBlock *MBBFrom = 0); 251 252 /// print - Print out the MachineFunction in a format suitable for debugging 253 /// to the specified stream. 254 /// 255 void print(raw_ostream &OS, SlotIndexes* = 0) const; 256 257 /// viewCFG - This function is meant for use from the debugger. You can just 258 /// say 'call F->viewCFG()' and a ghostview window should pop up from the 259 /// program, displaying the CFG of the current function with the code for each 260 /// basic block inside. This depends on there being a 'dot' and 'gv' program 261 /// in your path. 262 /// 263 void viewCFG() const; 264 265 /// viewCFGOnly - This function is meant for use from the debugger. It works 266 /// just like viewCFG, but it does not include the contents of basic blocks 267 /// into the nodes, just the label. If you are only interested in the CFG 268 /// this can make the graph smaller. 269 /// 270 void viewCFGOnly() const; 271 272 /// dump - Print the current MachineFunction to cerr, useful for debugger use. 273 /// 274 void dump() const; 275 276 /// verify - Run the current MachineFunction through the machine code 277 /// verifier, useful for debugger use. 278 void verify(Pass *p = NULL, const char *Banner = NULL) const; 279 280 // Provide accessors for the MachineBasicBlock list... 281 typedef BasicBlockListType::iterator iterator; 282 typedef BasicBlockListType::const_iterator const_iterator; 283 typedef std::reverse_iterator<const_iterator> const_reverse_iterator; 284 typedef std::reverse_iterator<iterator> reverse_iterator; 285 286 /// addLiveIn - Add the specified physical register as a live-in value and 287 /// create a corresponding virtual register for it. 288 unsigned addLiveIn(unsigned PReg, const TargetRegisterClass *RC); 289 290 //===--------------------------------------------------------------------===// 291 // BasicBlock accessor functions. 292 // 293 iterator begin() { return BasicBlocks.begin(); } 294 const_iterator begin() const { return BasicBlocks.begin(); } 295 iterator end () { return BasicBlocks.end(); } 296 const_iterator end () const { return BasicBlocks.end(); } 297 298 reverse_iterator rbegin() { return BasicBlocks.rbegin(); } 299 const_reverse_iterator rbegin() const { return BasicBlocks.rbegin(); } 300 reverse_iterator rend () { return BasicBlocks.rend(); } 301 const_reverse_iterator rend () const { return BasicBlocks.rend(); } 302 303 unsigned size() const { return (unsigned)BasicBlocks.size();} 304 bool empty() const { return BasicBlocks.empty(); } 305 const MachineBasicBlock &front() const { return BasicBlocks.front(); } 306 MachineBasicBlock &front() { return BasicBlocks.front(); } 307 const MachineBasicBlock & back() const { return BasicBlocks.back(); } 308 MachineBasicBlock & back() { return BasicBlocks.back(); } 309 310 void push_back (MachineBasicBlock *MBB) { BasicBlocks.push_back (MBB); } 311 void push_front(MachineBasicBlock *MBB) { BasicBlocks.push_front(MBB); } 312 void insert(iterator MBBI, MachineBasicBlock *MBB) { 313 BasicBlocks.insert(MBBI, MBB); 314 } 315 void splice(iterator InsertPt, iterator MBBI) { 316 BasicBlocks.splice(InsertPt, BasicBlocks, MBBI); 317 } 318 void splice(iterator InsertPt, iterator MBBI, iterator MBBE) { 319 BasicBlocks.splice(InsertPt, BasicBlocks, MBBI, MBBE); 320 } 321 322 void remove(iterator MBBI) { 323 BasicBlocks.remove(MBBI); 324 } 325 void erase(iterator MBBI) { 326 BasicBlocks.erase(MBBI); 327 } 328 329 //===--------------------------------------------------------------------===// 330 // Internal functions used to automatically number MachineBasicBlocks 331 // 332 333 /// getNextMBBNumber - Returns the next unique number to be assigned 334 /// to a MachineBasicBlock in this MachineFunction. 335 /// 336 unsigned addToMBBNumbering(MachineBasicBlock *MBB) { 337 MBBNumbering.push_back(MBB); 338 return (unsigned)MBBNumbering.size()-1; 339 } 340 341 /// removeFromMBBNumbering - Remove the specific machine basic block from our 342 /// tracker, this is only really to be used by the MachineBasicBlock 343 /// implementation. 344 void removeFromMBBNumbering(unsigned N) { 345 assert(N < MBBNumbering.size() && "Illegal basic block #"); 346 MBBNumbering[N] = 0; 347 } 348 349 /// CreateMachineInstr - Allocate a new MachineInstr. Use this instead 350 /// of `new MachineInstr'. 351 /// 352 MachineInstr *CreateMachineInstr(const MCInstrDesc &MCID, 353 DebugLoc DL, 354 bool NoImp = false); 355 356 /// CloneMachineInstr - Create a new MachineInstr which is a copy of the 357 /// 'Orig' instruction, identical in all ways except the instruction 358 /// has no parent, prev, or next. 359 /// 360 /// See also TargetInstrInfo::duplicate() for target-specific fixes to cloned 361 /// instructions. 362 MachineInstr *CloneMachineInstr(const MachineInstr *Orig); 363 364 /// DeleteMachineInstr - Delete the given MachineInstr. 365 /// 366 void DeleteMachineInstr(MachineInstr *MI); 367 368 /// CreateMachineBasicBlock - Allocate a new MachineBasicBlock. Use this 369 /// instead of `new MachineBasicBlock'. 370 /// 371 MachineBasicBlock *CreateMachineBasicBlock(const BasicBlock *bb = 0); 372 373 /// DeleteMachineBasicBlock - Delete the given MachineBasicBlock. 374 /// 375 void DeleteMachineBasicBlock(MachineBasicBlock *MBB); 376 377 /// getMachineMemOperand - Allocate a new MachineMemOperand. 378 /// MachineMemOperands are owned by the MachineFunction and need not be 379 /// explicitly deallocated. 380 MachineMemOperand *getMachineMemOperand(MachinePointerInfo PtrInfo, 381 unsigned f, uint64_t s, 382 unsigned base_alignment, 383 const MDNode *TBAAInfo = 0, 384 const MDNode *Ranges = 0); 385 386 /// getMachineMemOperand - Allocate a new MachineMemOperand by copying 387 /// an existing one, adjusting by an offset and using the given size. 388 /// MachineMemOperands are owned by the MachineFunction and need not be 389 /// explicitly deallocated. 390 MachineMemOperand *getMachineMemOperand(const MachineMemOperand *MMO, 391 int64_t Offset, uint64_t Size); 392 393 /// allocateMemRefsArray - Allocate an array to hold MachineMemOperand 394 /// pointers. This array is owned by the MachineFunction. 395 MachineInstr::mmo_iterator allocateMemRefsArray(unsigned long Num); 396 397 /// extractLoadMemRefs - Allocate an array and populate it with just the 398 /// load information from the given MachineMemOperand sequence. 399 std::pair<MachineInstr::mmo_iterator, 400 MachineInstr::mmo_iterator> 401 extractLoadMemRefs(MachineInstr::mmo_iterator Begin, 402 MachineInstr::mmo_iterator End); 403 404 /// extractStoreMemRefs - Allocate an array and populate it with just the 405 /// store information from the given MachineMemOperand sequence. 406 std::pair<MachineInstr::mmo_iterator, 407 MachineInstr::mmo_iterator> 408 extractStoreMemRefs(MachineInstr::mmo_iterator Begin, 409 MachineInstr::mmo_iterator End); 410 411 //===--------------------------------------------------------------------===// 412 // Label Manipulation. 413 // 414 415 /// getJTISymbol - Return the MCSymbol for the specified non-empty jump table. 416 /// If isLinkerPrivate is specified, an 'l' label is returned, otherwise a 417 /// normal 'L' label is returned. 418 MCSymbol *getJTISymbol(unsigned JTI, MCContext &Ctx, 419 bool isLinkerPrivate = false) const; 420 421 /// getPICBaseSymbol - Return a function-local symbol to represent the PIC 422 /// base. 423 MCSymbol *getPICBaseSymbol() const; 424 }; 425 426 //===--------------------------------------------------------------------===// 427 // GraphTraits specializations for function basic block graphs (CFGs) 428 //===--------------------------------------------------------------------===// 429 430 // Provide specializations of GraphTraits to be able to treat a 431 // machine function as a graph of machine basic blocks... these are 432 // the same as the machine basic block iterators, except that the root 433 // node is implicitly the first node of the function. 434 // 435 template <> struct GraphTraits<MachineFunction*> : 436 public GraphTraits<MachineBasicBlock*> { 437 static NodeType *getEntryNode(MachineFunction *F) { 438 return &F->front(); 439 } 440 441 // nodes_iterator/begin/end - Allow iteration over all nodes in the graph 442 typedef MachineFunction::iterator nodes_iterator; 443 static nodes_iterator nodes_begin(MachineFunction *F) { return F->begin(); } 444 static nodes_iterator nodes_end (MachineFunction *F) { return F->end(); } 445 static unsigned size (MachineFunction *F) { return F->size(); } 446 }; 447 template <> struct GraphTraits<const MachineFunction*> : 448 public GraphTraits<const MachineBasicBlock*> { 449 static NodeType *getEntryNode(const MachineFunction *F) { 450 return &F->front(); 451 } 452 453 // nodes_iterator/begin/end - Allow iteration over all nodes in the graph 454 typedef MachineFunction::const_iterator nodes_iterator; 455 static nodes_iterator nodes_begin(const MachineFunction *F) { 456 return F->begin(); 457 } 458 static nodes_iterator nodes_end (const MachineFunction *F) { 459 return F->end(); 460 } 461 static unsigned size (const MachineFunction *F) { 462 return F->size(); 463 } 464 }; 465 466 467 // Provide specializations of GraphTraits to be able to treat a function as a 468 // graph of basic blocks... and to walk it in inverse order. Inverse order for 469 // a function is considered to be when traversing the predecessor edges of a BB 470 // instead of the successor edges. 471 // 472 template <> struct GraphTraits<Inverse<MachineFunction*> > : 473 public GraphTraits<Inverse<MachineBasicBlock*> > { 474 static NodeType *getEntryNode(Inverse<MachineFunction*> G) { 475 return &G.Graph->front(); 476 } 477 }; 478 template <> struct GraphTraits<Inverse<const MachineFunction*> > : 479 public GraphTraits<Inverse<const MachineBasicBlock*> > { 480 static NodeType *getEntryNode(Inverse<const MachineFunction *> G) { 481 return &G.Graph->front(); 482 } 483 }; 484 485 } // End llvm namespace 486 487 #endif 488
