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/ADT/ilist.h" 22 #include "llvm/CodeGen/MachineBasicBlock.h" 23 #include "llvm/IR/DebugLoc.h" 24 #include "llvm/Support/Allocator.h" 25 #include "llvm/Support/ArrayRecycler.h" 26 #include "llvm/Support/Recycler.h" 27 28 namespace llvm { 29 30 class Value; 31 class Function; 32 class GCModuleInfo; 33 class MachineRegisterInfo; 34 class MachineFrameInfo; 35 class MachineConstantPool; 36 class MachineJumpTableInfo; 37 class MachineModuleInfo; 38 class MCContext; 39 class Pass; 40 class TargetMachine; 41 class TargetRegisterClass; 42 struct MachinePointerInfo; 43 44 template <> 45 struct ilist_traits<MachineBasicBlock> 46 : public ilist_default_traits<MachineBasicBlock> { 47 mutable ilist_half_node<MachineBasicBlock> Sentinel; 48 public: 49 MachineBasicBlock *createSentinel() const { 50 return static_cast<MachineBasicBlock*>(&Sentinel); 51 } 52 void destroySentinel(MachineBasicBlock *) const {} 53 54 MachineBasicBlock *provideInitialHead() const { return createSentinel(); } 55 MachineBasicBlock *ensureHead(MachineBasicBlock*) const { 56 return createSentinel(); 57 } 58 static void noteHead(MachineBasicBlock*, MachineBasicBlock*) {} 59 60 void addNodeToList(MachineBasicBlock* MBB); 61 void removeNodeFromList(MachineBasicBlock* MBB); 62 void deleteNode(MachineBasicBlock *MBB); 63 private: 64 void createNode(const MachineBasicBlock &); 65 }; 66 67 /// MachineFunctionInfo - This class can be derived from and used by targets to 68 /// hold private target-specific information for each MachineFunction. Objects 69 /// of type are accessed/created with MF::getInfo and destroyed when the 70 /// MachineFunction is destroyed. 71 struct MachineFunctionInfo { 72 virtual ~MachineFunctionInfo(); 73 }; 74 75 class MachineFunction { 76 const Function *Fn; 77 const TargetMachine &Target; 78 MCContext &Ctx; 79 MachineModuleInfo &MMI; 80 GCModuleInfo *GMI; 81 82 // RegInfo - Information about each register in use in the function. 83 MachineRegisterInfo *RegInfo; 84 85 // Used to keep track of target-specific per-machine function information for 86 // the target implementation. 87 MachineFunctionInfo *MFInfo; 88 89 // Keep track of objects allocated on the stack. 90 MachineFrameInfo *FrameInfo; 91 92 // Keep track of constants which are spilled to memory 93 MachineConstantPool *ConstantPool; 94 95 // Keep track of jump tables for switch instructions 96 MachineJumpTableInfo *JumpTableInfo; 97 98 // Function-level unique numbering for MachineBasicBlocks. When a 99 // MachineBasicBlock is inserted into a MachineFunction is it automatically 100 // numbered and this vector keeps track of the mapping from ID's to MBB's. 101 std::vector<MachineBasicBlock*> MBBNumbering; 102 103 // Pool-allocate MachineFunction-lifetime and IR objects. 104 BumpPtrAllocator Allocator; 105 106 // Allocation management for instructions in function. 107 Recycler<MachineInstr> InstructionRecycler; 108 109 // Allocation management for operand arrays on instructions. 110 ArrayRecycler<MachineOperand> OperandRecycler; 111 112 // Allocation management for basic blocks in function. 113 Recycler<MachineBasicBlock> BasicBlockRecycler; 114 115 // List of machine basic blocks in function 116 typedef ilist<MachineBasicBlock> BasicBlockListType; 117 BasicBlockListType BasicBlocks; 118 119 /// FunctionNumber - This provides a unique ID for each function emitted in 120 /// this translation unit. 121 /// 122 unsigned FunctionNumber; 123 124 /// Alignment - The alignment of the function. 125 unsigned Alignment; 126 127 /// ExposesReturnsTwice - True if the function calls setjmp or related 128 /// functions with attribute "returns twice", but doesn't have 129 /// the attribute itself. 130 /// This is used to limit optimizations which cannot reason 131 /// about the control flow of such functions. 132 bool ExposesReturnsTwice; 133 134 /// True if the function includes any inline assembly. 135 bool HasInlineAsm; 136 137 MachineFunction(const MachineFunction &) LLVM_DELETED_FUNCTION; 138 void operator=(const MachineFunction&) LLVM_DELETED_FUNCTION; 139 public: 140 MachineFunction(const Function *Fn, const TargetMachine &TM, 141 unsigned FunctionNum, MachineModuleInfo &MMI, 142 GCModuleInfo* GMI); 143 ~MachineFunction(); 144 145 MachineModuleInfo &getMMI() const { return MMI; } 146 GCModuleInfo *getGMI() const { return GMI; } 147 MCContext &getContext() const { return Ctx; } 148 149 /// getFunction - Return the LLVM function that this machine code represents 150 /// 151 const Function *getFunction() const { return Fn; } 152 153 /// getName - Return the name of the corresponding LLVM function. 154 /// 155 StringRef getName() const; 156 157 /// getFunctionNumber - Return a unique ID for the current function. 158 /// 159 unsigned getFunctionNumber() const { return FunctionNumber; } 160 161 /// getTarget - Return the target machine this machine code is compiled with 162 /// 163 const TargetMachine &getTarget() const { return Target; } 164 165 /// getRegInfo - Return information about the registers currently in use. 166 /// 167 MachineRegisterInfo &getRegInfo() { return *RegInfo; } 168 const MachineRegisterInfo &getRegInfo() const { return *RegInfo; } 169 170 /// getFrameInfo - Return the frame info object for the current function. 171 /// This object contains information about objects allocated on the stack 172 /// frame of the current function in an abstract way. 173 /// 174 MachineFrameInfo *getFrameInfo() { return FrameInfo; } 175 const MachineFrameInfo *getFrameInfo() const { return FrameInfo; } 176 177 /// getJumpTableInfo - Return the jump table info object for the current 178 /// function. This object contains information about jump tables in the 179 /// current function. If the current function has no jump tables, this will 180 /// return null. 181 const MachineJumpTableInfo *getJumpTableInfo() const { return JumpTableInfo; } 182 MachineJumpTableInfo *getJumpTableInfo() { return JumpTableInfo; } 183 184 /// getOrCreateJumpTableInfo - Get the JumpTableInfo for this function, if it 185 /// does already exist, allocate one. 186 MachineJumpTableInfo *getOrCreateJumpTableInfo(unsigned JTEntryKind); 187 188 189 /// getConstantPool - Return the constant pool object for the current 190 /// function. 191 /// 192 MachineConstantPool *getConstantPool() { return ConstantPool; } 193 const MachineConstantPool *getConstantPool() const { return ConstantPool; } 194 195 /// getAlignment - Return the alignment (log2, not bytes) of the function. 196 /// 197 unsigned getAlignment() const { return Alignment; } 198 199 /// setAlignment - Set the alignment (log2, not bytes) of the function. 200 /// 201 void setAlignment(unsigned A) { Alignment = A; } 202 203 /// ensureAlignment - Make sure the function is at least 1 << A bytes aligned. 204 void ensureAlignment(unsigned A) { 205 if (Alignment < A) Alignment = A; 206 } 207 208 /// exposesReturnsTwice - Returns true if the function calls setjmp or 209 /// any other similar functions with attribute "returns twice" without 210 /// having the attribute itself. 211 bool exposesReturnsTwice() const { 212 return ExposesReturnsTwice; 213 } 214 215 /// setCallsSetJmp - Set a flag that indicates if there's a call to 216 /// a "returns twice" function. 217 void setExposesReturnsTwice(bool B) { 218 ExposesReturnsTwice = B; 219 } 220 221 /// Returns true if the function contains any inline assembly. 222 bool hasInlineAsm() const { 223 return HasInlineAsm; 224 } 225 226 /// Set a flag that indicates that the function contains inline assembly. 227 void setHasInlineAsm(bool B) { 228 HasInlineAsm = B; 229 } 230 231 /// getInfo - Keep track of various per-function pieces of information for 232 /// backends that would like to do so. 233 /// 234 template<typename Ty> 235 Ty *getInfo() { 236 if (!MFInfo) { 237 // This should be just `new (Allocator.Allocate<Ty>()) Ty(*this)', but 238 // that apparently breaks GCC 3.3. 239 Ty *Loc = static_cast<Ty*>(Allocator.Allocate(sizeof(Ty), 240 AlignOf<Ty>::Alignment)); 241 MFInfo = new (Loc) Ty(*this); 242 } 243 return static_cast<Ty*>(MFInfo); 244 } 245 246 template<typename Ty> 247 const Ty *getInfo() const { 248 return const_cast<MachineFunction*>(this)->getInfo<Ty>(); 249 } 250 251 /// getBlockNumbered - MachineBasicBlocks are automatically numbered when they 252 /// are inserted into the machine function. The block number for a machine 253 /// basic block can be found by using the MBB::getBlockNumber method, this 254 /// method provides the inverse mapping. 255 /// 256 MachineBasicBlock *getBlockNumbered(unsigned N) const { 257 assert(N < MBBNumbering.size() && "Illegal block number"); 258 assert(MBBNumbering[N] && "Block was removed from the machine function!"); 259 return MBBNumbering[N]; 260 } 261 262 /// Should we be emitting segmented stack stuff for the function 263 bool shouldSplitStack(); 264 265 /// getNumBlockIDs - Return the number of MBB ID's allocated. 266 /// 267 unsigned getNumBlockIDs() const { return (unsigned)MBBNumbering.size(); } 268 269 /// RenumberBlocks - This discards all of the MachineBasicBlock numbers and 270 /// recomputes them. This guarantees that the MBB numbers are sequential, 271 /// dense, and match the ordering of the blocks within the function. If a 272 /// specific MachineBasicBlock is specified, only that block and those after 273 /// it are renumbered. 274 void RenumberBlocks(MachineBasicBlock *MBBFrom = nullptr); 275 276 /// print - Print out the MachineFunction in a format suitable for debugging 277 /// to the specified stream. 278 /// 279 void print(raw_ostream &OS, SlotIndexes* = nullptr) const; 280 281 /// viewCFG - This function is meant for use from the debugger. You can just 282 /// say 'call F->viewCFG()' and a ghostview window should pop up from the 283 /// program, displaying the CFG of the current function with the code for each 284 /// basic block inside. This depends on there being a 'dot' and 'gv' program 285 /// in your path. 286 /// 287 void viewCFG() const; 288 289 /// viewCFGOnly - This function is meant for use from the debugger. It works 290 /// just like viewCFG, but it does not include the contents of basic blocks 291 /// into the nodes, just the label. If you are only interested in the CFG 292 /// this can make the graph smaller. 293 /// 294 void viewCFGOnly() const; 295 296 /// dump - Print the current MachineFunction to cerr, useful for debugger use. 297 /// 298 void dump() const; 299 300 /// verify - Run the current MachineFunction through the machine code 301 /// verifier, useful for debugger use. 302 void verify(Pass *p = nullptr, const char *Banner = nullptr) const; 303 304 // Provide accessors for the MachineBasicBlock list... 305 typedef BasicBlockListType::iterator iterator; 306 typedef BasicBlockListType::const_iterator const_iterator; 307 typedef std::reverse_iterator<const_iterator> const_reverse_iterator; 308 typedef std::reverse_iterator<iterator> reverse_iterator; 309 310 /// addLiveIn - Add the specified physical register as a live-in value and 311 /// create a corresponding virtual register for it. 312 unsigned addLiveIn(unsigned PReg, const TargetRegisterClass *RC); 313 314 //===--------------------------------------------------------------------===// 315 // BasicBlock accessor functions. 316 // 317 iterator begin() { return BasicBlocks.begin(); } 318 const_iterator begin() const { return BasicBlocks.begin(); } 319 iterator end () { return BasicBlocks.end(); } 320 const_iterator end () const { return BasicBlocks.end(); } 321 322 reverse_iterator rbegin() { return BasicBlocks.rbegin(); } 323 const_reverse_iterator rbegin() const { return BasicBlocks.rbegin(); } 324 reverse_iterator rend () { return BasicBlocks.rend(); } 325 const_reverse_iterator rend () const { return BasicBlocks.rend(); } 326 327 unsigned size() const { return (unsigned)BasicBlocks.size();} 328 bool empty() const { return BasicBlocks.empty(); } 329 const MachineBasicBlock &front() const { return BasicBlocks.front(); } 330 MachineBasicBlock &front() { return BasicBlocks.front(); } 331 const MachineBasicBlock & back() const { return BasicBlocks.back(); } 332 MachineBasicBlock & back() { return BasicBlocks.back(); } 333 334 void push_back (MachineBasicBlock *MBB) { BasicBlocks.push_back (MBB); } 335 void push_front(MachineBasicBlock *MBB) { BasicBlocks.push_front(MBB); } 336 void insert(iterator MBBI, MachineBasicBlock *MBB) { 337 BasicBlocks.insert(MBBI, MBB); 338 } 339 void splice(iterator InsertPt, iterator MBBI) { 340 BasicBlocks.splice(InsertPt, BasicBlocks, MBBI); 341 } 342 void splice(iterator InsertPt, iterator MBBI, iterator MBBE) { 343 BasicBlocks.splice(InsertPt, BasicBlocks, MBBI, MBBE); 344 } 345 346 void remove(iterator MBBI) { 347 BasicBlocks.remove(MBBI); 348 } 349 void erase(iterator MBBI) { 350 BasicBlocks.erase(MBBI); 351 } 352 353 //===--------------------------------------------------------------------===// 354 // Internal functions used to automatically number MachineBasicBlocks 355 // 356 357 /// \brief Adds the MBB to the internal numbering. Returns the unique number 358 /// assigned to the MBB. 359 /// 360 unsigned addToMBBNumbering(MachineBasicBlock *MBB) { 361 MBBNumbering.push_back(MBB); 362 return (unsigned)MBBNumbering.size()-1; 363 } 364 365 /// removeFromMBBNumbering - Remove the specific machine basic block from our 366 /// tracker, this is only really to be used by the MachineBasicBlock 367 /// implementation. 368 void removeFromMBBNumbering(unsigned N) { 369 assert(N < MBBNumbering.size() && "Illegal basic block #"); 370 MBBNumbering[N] = nullptr; 371 } 372 373 /// CreateMachineInstr - Allocate a new MachineInstr. Use this instead 374 /// of `new MachineInstr'. 375 /// 376 MachineInstr *CreateMachineInstr(const MCInstrDesc &MCID, 377 DebugLoc DL, 378 bool NoImp = false); 379 380 /// CloneMachineInstr - Create a new MachineInstr which is a copy of the 381 /// 'Orig' instruction, identical in all ways except the instruction 382 /// has no parent, prev, or next. 383 /// 384 /// See also TargetInstrInfo::duplicate() for target-specific fixes to cloned 385 /// instructions. 386 MachineInstr *CloneMachineInstr(const MachineInstr *Orig); 387 388 /// DeleteMachineInstr - Delete the given MachineInstr. 389 /// 390 void DeleteMachineInstr(MachineInstr *MI); 391 392 /// CreateMachineBasicBlock - Allocate a new MachineBasicBlock. Use this 393 /// instead of `new MachineBasicBlock'. 394 /// 395 MachineBasicBlock *CreateMachineBasicBlock(const BasicBlock *bb = nullptr); 396 397 /// DeleteMachineBasicBlock - Delete the given MachineBasicBlock. 398 /// 399 void DeleteMachineBasicBlock(MachineBasicBlock *MBB); 400 401 /// getMachineMemOperand - Allocate a new MachineMemOperand. 402 /// MachineMemOperands are owned by the MachineFunction and need not be 403 /// explicitly deallocated. 404 MachineMemOperand *getMachineMemOperand(MachinePointerInfo PtrInfo, 405 unsigned f, uint64_t s, 406 unsigned base_alignment, 407 const MDNode *TBAAInfo = nullptr, 408 const MDNode *Ranges = nullptr); 409 410 /// getMachineMemOperand - Allocate a new MachineMemOperand by copying 411 /// an existing one, adjusting by an offset and using the given size. 412 /// MachineMemOperands are owned by the MachineFunction and need not be 413 /// explicitly deallocated. 414 MachineMemOperand *getMachineMemOperand(const MachineMemOperand *MMO, 415 int64_t Offset, uint64_t Size); 416 417 typedef ArrayRecycler<MachineOperand>::Capacity OperandCapacity; 418 419 /// Allocate an array of MachineOperands. This is only intended for use by 420 /// internal MachineInstr functions. 421 MachineOperand *allocateOperandArray(OperandCapacity Cap) { 422 return OperandRecycler.allocate(Cap, Allocator); 423 } 424 425 /// Dellocate an array of MachineOperands and recycle the memory. This is 426 /// only intended for use by internal MachineInstr functions. 427 /// Cap must be the same capacity that was used to allocate the array. 428 void deallocateOperandArray(OperandCapacity Cap, MachineOperand *Array) { 429 OperandRecycler.deallocate(Cap, Array); 430 } 431 432 /// \brief Allocate and initialize a register mask with @p NumRegister bits. 433 uint32_t *allocateRegisterMask(unsigned NumRegister) { 434 unsigned Size = (NumRegister + 31) / 32; 435 uint32_t *Mask = Allocator.Allocate<uint32_t>(Size); 436 for (unsigned i = 0; i != Size; ++i) 437 Mask[i] = 0; 438 return Mask; 439 } 440 441 /// allocateMemRefsArray - Allocate an array to hold MachineMemOperand 442 /// pointers. This array is owned by the MachineFunction. 443 MachineInstr::mmo_iterator allocateMemRefsArray(unsigned long Num); 444 445 /// extractLoadMemRefs - Allocate an array and populate it with just the 446 /// load information from the given MachineMemOperand sequence. 447 std::pair<MachineInstr::mmo_iterator, 448 MachineInstr::mmo_iterator> 449 extractLoadMemRefs(MachineInstr::mmo_iterator Begin, 450 MachineInstr::mmo_iterator End); 451 452 /// extractStoreMemRefs - Allocate an array and populate it with just the 453 /// store information from the given MachineMemOperand sequence. 454 std::pair<MachineInstr::mmo_iterator, 455 MachineInstr::mmo_iterator> 456 extractStoreMemRefs(MachineInstr::mmo_iterator Begin, 457 MachineInstr::mmo_iterator End); 458 459 //===--------------------------------------------------------------------===// 460 // Label Manipulation. 461 // 462 463 /// getJTISymbol - Return the MCSymbol for the specified non-empty jump table. 464 /// If isLinkerPrivate is specified, an 'l' label is returned, otherwise a 465 /// normal 'L' label is returned. 466 MCSymbol *getJTISymbol(unsigned JTI, MCContext &Ctx, 467 bool isLinkerPrivate = false) const; 468 469 /// getPICBaseSymbol - Return a function-local symbol to represent the PIC 470 /// base. 471 MCSymbol *getPICBaseSymbol() const; 472 }; 473 474 //===--------------------------------------------------------------------===// 475 // GraphTraits specializations for function basic block graphs (CFGs) 476 //===--------------------------------------------------------------------===// 477 478 // Provide specializations of GraphTraits to be able to treat a 479 // machine function as a graph of machine basic blocks... these are 480 // the same as the machine basic block iterators, except that the root 481 // node is implicitly the first node of the function. 482 // 483 template <> struct GraphTraits<MachineFunction*> : 484 public GraphTraits<MachineBasicBlock*> { 485 static NodeType *getEntryNode(MachineFunction *F) { 486 return &F->front(); 487 } 488 489 // nodes_iterator/begin/end - Allow iteration over all nodes in the graph 490 typedef MachineFunction::iterator nodes_iterator; 491 static nodes_iterator nodes_begin(MachineFunction *F) { return F->begin(); } 492 static nodes_iterator nodes_end (MachineFunction *F) { return F->end(); } 493 static unsigned size (MachineFunction *F) { return F->size(); } 494 }; 495 template <> struct GraphTraits<const MachineFunction*> : 496 public GraphTraits<const MachineBasicBlock*> { 497 static NodeType *getEntryNode(const MachineFunction *F) { 498 return &F->front(); 499 } 500 501 // nodes_iterator/begin/end - Allow iteration over all nodes in the graph 502 typedef MachineFunction::const_iterator nodes_iterator; 503 static nodes_iterator nodes_begin(const MachineFunction *F) { 504 return F->begin(); 505 } 506 static nodes_iterator nodes_end (const MachineFunction *F) { 507 return F->end(); 508 } 509 static unsigned size (const MachineFunction *F) { 510 return F->size(); 511 } 512 }; 513 514 515 // Provide specializations of GraphTraits to be able to treat a function as a 516 // graph of basic blocks... and to walk it in inverse order. Inverse order for 517 // a function is considered to be when traversing the predecessor edges of a BB 518 // instead of the successor edges. 519 // 520 template <> struct GraphTraits<Inverse<MachineFunction*> > : 521 public GraphTraits<Inverse<MachineBasicBlock*> > { 522 static NodeType *getEntryNode(Inverse<MachineFunction*> G) { 523 return &G.Graph->front(); 524 } 525 }; 526 template <> struct GraphTraits<Inverse<const MachineFunction*> > : 527 public GraphTraits<Inverse<const MachineBasicBlock*> > { 528 static NodeType *getEntryNode(Inverse<const MachineFunction *> G) { 529 return &G.Graph->front(); 530 } 531 }; 532 533 } // End llvm namespace 534 535 #endif 536
