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 /// getName - Return the name of the corresponding LLVM function. 147 /// 148 StringRef getName() const; 149 150 /// getFunctionNumber - Return a unique ID for the current function. 151 /// 152 unsigned getFunctionNumber() const { return FunctionNumber; } 153 154 /// getTarget - Return the target machine this machine code is compiled with 155 /// 156 const TargetMachine &getTarget() const { return Target; } 157 158 /// getRegInfo - Return information about the registers currently in use. 159 /// 160 MachineRegisterInfo &getRegInfo() { return *RegInfo; } 161 const MachineRegisterInfo &getRegInfo() const { return *RegInfo; } 162 163 /// getFrameInfo - Return the frame info object for the current function. 164 /// This object contains information about objects allocated on the stack 165 /// frame of the current function in an abstract way. 166 /// 167 MachineFrameInfo *getFrameInfo() { return FrameInfo; } 168 const MachineFrameInfo *getFrameInfo() const { return FrameInfo; } 169 170 /// getJumpTableInfo - Return the jump table info object for the current 171 /// function. This object contains information about jump tables in the 172 /// current function. If the current function has no jump tables, this will 173 /// return null. 174 const MachineJumpTableInfo *getJumpTableInfo() const { return JumpTableInfo; } 175 MachineJumpTableInfo *getJumpTableInfo() { return JumpTableInfo; } 176 177 /// getOrCreateJumpTableInfo - Get the JumpTableInfo for this function, if it 178 /// does already exist, allocate one. 179 MachineJumpTableInfo *getOrCreateJumpTableInfo(unsigned JTEntryKind); 180 181 182 /// getConstantPool - Return the constant pool object for the current 183 /// function. 184 /// 185 MachineConstantPool *getConstantPool() { return ConstantPool; } 186 const MachineConstantPool *getConstantPool() const { return ConstantPool; } 187 188 /// getAlignment - Return the alignment (log2, not bytes) of the function. 189 /// 190 unsigned getAlignment() const { return Alignment; } 191 192 /// setAlignment - Set the alignment (log2, not bytes) of the function. 193 /// 194 void setAlignment(unsigned A) { Alignment = A; } 195 196 /// ensureAlignment - Make sure the function is at least 1 << A bytes aligned. 197 void ensureAlignment(unsigned A) { 198 if (Alignment < A) Alignment = A; 199 } 200 201 /// exposesReturnsTwice - Returns true if the function calls setjmp or 202 /// any other similar functions with attribute "returns twice" without 203 /// having the attribute itself. 204 bool exposesReturnsTwice() const { 205 return ExposesReturnsTwice; 206 } 207 208 /// setCallsSetJmp - Set a flag that indicates if there's a call to 209 /// a "returns twice" function. 210 void setExposesReturnsTwice(bool B) { 211 ExposesReturnsTwice = B; 212 } 213 214 /// getInfo - Keep track of various per-function pieces of information for 215 /// backends that would like to do so. 216 /// 217 template<typename Ty> 218 Ty *getInfo() { 219 if (!MFInfo) { 220 // This should be just `new (Allocator.Allocate<Ty>()) Ty(*this)', but 221 // that apparently breaks GCC 3.3. 222 Ty *Loc = static_cast<Ty*>(Allocator.Allocate(sizeof(Ty), 223 AlignOf<Ty>::Alignment)); 224 MFInfo = new (Loc) Ty(*this); 225 } 226 return static_cast<Ty*>(MFInfo); 227 } 228 229 template<typename Ty> 230 const Ty *getInfo() const { 231 return const_cast<MachineFunction*>(this)->getInfo<Ty>(); 232 } 233 234 /// getBlockNumbered - MachineBasicBlocks are automatically numbered when they 235 /// are inserted into the machine function. The block number for a machine 236 /// basic block can be found by using the MBB::getBlockNumber method, this 237 /// method provides the inverse mapping. 238 /// 239 MachineBasicBlock *getBlockNumbered(unsigned N) const { 240 assert(N < MBBNumbering.size() && "Illegal block number"); 241 assert(MBBNumbering[N] && "Block was removed from the machine function!"); 242 return MBBNumbering[N]; 243 } 244 245 /// getNumBlockIDs - Return the number of MBB ID's allocated. 246 /// 247 unsigned getNumBlockIDs() const { return (unsigned)MBBNumbering.size(); } 248 249 /// RenumberBlocks - This discards all of the MachineBasicBlock numbers and 250 /// recomputes them. This guarantees that the MBB numbers are sequential, 251 /// dense, and match the ordering of the blocks within the function. If a 252 /// specific MachineBasicBlock is specified, only that block and those after 253 /// it are renumbered. 254 void RenumberBlocks(MachineBasicBlock *MBBFrom = 0); 255 256 /// print - Print out the MachineFunction in a format suitable for debugging 257 /// to the specified stream. 258 /// 259 void print(raw_ostream &OS, SlotIndexes* = 0) const; 260 261 /// viewCFG - This function is meant for use from the debugger. You can just 262 /// say 'call F->viewCFG()' and a ghostview window should pop up from the 263 /// program, displaying the CFG of the current function with the code for each 264 /// basic block inside. This depends on there being a 'dot' and 'gv' program 265 /// in your path. 266 /// 267 void viewCFG() const; 268 269 /// viewCFGOnly - This function is meant for use from the debugger. It works 270 /// just like viewCFG, but it does not include the contents of basic blocks 271 /// into the nodes, just the label. If you are only interested in the CFG 272 /// this can make the graph smaller. 273 /// 274 void viewCFGOnly() const; 275 276 /// dump - Print the current MachineFunction to cerr, useful for debugger use. 277 /// 278 void dump() const; 279 280 /// verify - Run the current MachineFunction through the machine code 281 /// verifier, useful for debugger use. 282 void verify(Pass *p = NULL, const char *Banner = NULL) const; 283 284 // Provide accessors for the MachineBasicBlock list... 285 typedef BasicBlockListType::iterator iterator; 286 typedef BasicBlockListType::const_iterator const_iterator; 287 typedef std::reverse_iterator<const_iterator> const_reverse_iterator; 288 typedef std::reverse_iterator<iterator> reverse_iterator; 289 290 /// addLiveIn - Add the specified physical register as a live-in value and 291 /// create a corresponding virtual register for it. 292 unsigned addLiveIn(unsigned PReg, const TargetRegisterClass *RC); 293 294 //===--------------------------------------------------------------------===// 295 // BasicBlock accessor functions. 296 // 297 iterator begin() { return BasicBlocks.begin(); } 298 const_iterator begin() const { return BasicBlocks.begin(); } 299 iterator end () { return BasicBlocks.end(); } 300 const_iterator end () const { return BasicBlocks.end(); } 301 302 reverse_iterator rbegin() { return BasicBlocks.rbegin(); } 303 const_reverse_iterator rbegin() const { return BasicBlocks.rbegin(); } 304 reverse_iterator rend () { return BasicBlocks.rend(); } 305 const_reverse_iterator rend () const { return BasicBlocks.rend(); } 306 307 unsigned size() const { return (unsigned)BasicBlocks.size();} 308 bool empty() const { return BasicBlocks.empty(); } 309 const MachineBasicBlock &front() const { return BasicBlocks.front(); } 310 MachineBasicBlock &front() { return BasicBlocks.front(); } 311 const MachineBasicBlock & back() const { return BasicBlocks.back(); } 312 MachineBasicBlock & back() { return BasicBlocks.back(); } 313 314 void push_back (MachineBasicBlock *MBB) { BasicBlocks.push_back (MBB); } 315 void push_front(MachineBasicBlock *MBB) { BasicBlocks.push_front(MBB); } 316 void insert(iterator MBBI, MachineBasicBlock *MBB) { 317 BasicBlocks.insert(MBBI, MBB); 318 } 319 void splice(iterator InsertPt, iterator MBBI) { 320 BasicBlocks.splice(InsertPt, BasicBlocks, MBBI); 321 } 322 void splice(iterator InsertPt, iterator MBBI, iterator MBBE) { 323 BasicBlocks.splice(InsertPt, BasicBlocks, MBBI, MBBE); 324 } 325 326 void remove(iterator MBBI) { 327 BasicBlocks.remove(MBBI); 328 } 329 void erase(iterator MBBI) { 330 BasicBlocks.erase(MBBI); 331 } 332 333 //===--------------------------------------------------------------------===// 334 // Internal functions used to automatically number MachineBasicBlocks 335 // 336 337 /// getNextMBBNumber - Returns the next unique number to be assigned 338 /// to a MachineBasicBlock in this MachineFunction. 339 /// 340 unsigned addToMBBNumbering(MachineBasicBlock *MBB) { 341 MBBNumbering.push_back(MBB); 342 return (unsigned)MBBNumbering.size()-1; 343 } 344 345 /// removeFromMBBNumbering - Remove the specific machine basic block from our 346 /// tracker, this is only really to be used by the MachineBasicBlock 347 /// implementation. 348 void removeFromMBBNumbering(unsigned N) { 349 assert(N < MBBNumbering.size() && "Illegal basic block #"); 350 MBBNumbering[N] = 0; 351 } 352 353 /// CreateMachineInstr - Allocate a new MachineInstr. Use this instead 354 /// of `new MachineInstr'. 355 /// 356 MachineInstr *CreateMachineInstr(const MCInstrDesc &MCID, 357 DebugLoc DL, 358 bool NoImp = false); 359 360 /// CloneMachineInstr - Create a new MachineInstr which is a copy of the 361 /// 'Orig' instruction, identical in all ways except the instruction 362 /// has no parent, prev, or next. 363 /// 364 /// See also TargetInstrInfo::duplicate() for target-specific fixes to cloned 365 /// instructions. 366 MachineInstr *CloneMachineInstr(const MachineInstr *Orig); 367 368 /// DeleteMachineInstr - Delete the given MachineInstr. 369 /// 370 void DeleteMachineInstr(MachineInstr *MI); 371 372 /// CreateMachineBasicBlock - Allocate a new MachineBasicBlock. Use this 373 /// instead of `new MachineBasicBlock'. 374 /// 375 MachineBasicBlock *CreateMachineBasicBlock(const BasicBlock *bb = 0); 376 377 /// DeleteMachineBasicBlock - Delete the given MachineBasicBlock. 378 /// 379 void DeleteMachineBasicBlock(MachineBasicBlock *MBB); 380 381 /// getMachineMemOperand - Allocate a new MachineMemOperand. 382 /// MachineMemOperands are owned by the MachineFunction and need not be 383 /// explicitly deallocated. 384 MachineMemOperand *getMachineMemOperand(MachinePointerInfo PtrInfo, 385 unsigned f, uint64_t s, 386 unsigned base_alignment, 387 const MDNode *TBAAInfo = 0, 388 const MDNode *Ranges = 0); 389 390 /// getMachineMemOperand - Allocate a new MachineMemOperand by copying 391 /// an existing one, adjusting by an offset and using the given size. 392 /// MachineMemOperands are owned by the MachineFunction and need not be 393 /// explicitly deallocated. 394 MachineMemOperand *getMachineMemOperand(const MachineMemOperand *MMO, 395 int64_t Offset, uint64_t Size); 396 397 /// allocateMemRefsArray - Allocate an array to hold MachineMemOperand 398 /// pointers. This array is owned by the MachineFunction. 399 MachineInstr::mmo_iterator allocateMemRefsArray(unsigned long Num); 400 401 /// extractLoadMemRefs - Allocate an array and populate it with just the 402 /// load information from the given MachineMemOperand sequence. 403 std::pair<MachineInstr::mmo_iterator, 404 MachineInstr::mmo_iterator> 405 extractLoadMemRefs(MachineInstr::mmo_iterator Begin, 406 MachineInstr::mmo_iterator End); 407 408 /// extractStoreMemRefs - Allocate an array and populate it with just the 409 /// store information from the given MachineMemOperand sequence. 410 std::pair<MachineInstr::mmo_iterator, 411 MachineInstr::mmo_iterator> 412 extractStoreMemRefs(MachineInstr::mmo_iterator Begin, 413 MachineInstr::mmo_iterator End); 414 415 //===--------------------------------------------------------------------===// 416 // Label Manipulation. 417 // 418 419 /// getJTISymbol - Return the MCSymbol for the specified non-empty jump table. 420 /// If isLinkerPrivate is specified, an 'l' label is returned, otherwise a 421 /// normal 'L' label is returned. 422 MCSymbol *getJTISymbol(unsigned JTI, MCContext &Ctx, 423 bool isLinkerPrivate = false) const; 424 425 /// getPICBaseSymbol - Return a function-local symbol to represent the PIC 426 /// base. 427 MCSymbol *getPICBaseSymbol() const; 428 }; 429 430 //===--------------------------------------------------------------------===// 431 // GraphTraits specializations for function basic block graphs (CFGs) 432 //===--------------------------------------------------------------------===// 433 434 // Provide specializations of GraphTraits to be able to treat a 435 // machine function as a graph of machine basic blocks... these are 436 // the same as the machine basic block iterators, except that the root 437 // node is implicitly the first node of the function. 438 // 439 template <> struct GraphTraits<MachineFunction*> : 440 public GraphTraits<MachineBasicBlock*> { 441 static NodeType *getEntryNode(MachineFunction *F) { 442 return &F->front(); 443 } 444 445 // nodes_iterator/begin/end - Allow iteration over all nodes in the graph 446 typedef MachineFunction::iterator nodes_iterator; 447 static nodes_iterator nodes_begin(MachineFunction *F) { return F->begin(); } 448 static nodes_iterator nodes_end (MachineFunction *F) { return F->end(); } 449 static unsigned size (MachineFunction *F) { return F->size(); } 450 }; 451 template <> struct GraphTraits<const MachineFunction*> : 452 public GraphTraits<const MachineBasicBlock*> { 453 static NodeType *getEntryNode(const MachineFunction *F) { 454 return &F->front(); 455 } 456 457 // nodes_iterator/begin/end - Allow iteration over all nodes in the graph 458 typedef MachineFunction::const_iterator nodes_iterator; 459 static nodes_iterator nodes_begin(const MachineFunction *F) { 460 return F->begin(); 461 } 462 static nodes_iterator nodes_end (const MachineFunction *F) { 463 return F->end(); 464 } 465 static unsigned size (const MachineFunction *F) { 466 return F->size(); 467 } 468 }; 469 470 471 // Provide specializations of GraphTraits to be able to treat a function as a 472 // graph of basic blocks... and to walk it in inverse order. Inverse order for 473 // a function is considered to be when traversing the predecessor edges of a BB 474 // instead of the successor edges. 475 // 476 template <> struct GraphTraits<Inverse<MachineFunction*> > : 477 public GraphTraits<Inverse<MachineBasicBlock*> > { 478 static NodeType *getEntryNode(Inverse<MachineFunction*> G) { 479 return &G.Graph->front(); 480 } 481 }; 482 template <> struct GraphTraits<Inverse<const MachineFunction*> > : 483 public GraphTraits<Inverse<const MachineBasicBlock*> > { 484 static NodeType *getEntryNode(Inverse<const MachineFunction *> G) { 485 return &G.Graph->front(); 486 } 487 }; 488 489 } // End llvm namespace 490 491 #endif 492
