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/IR/Metadata.h" 25 #include "llvm/Support/Allocator.h" 26 #include "llvm/Support/ArrayRecycler.h" 27 #include "llvm/Support/Recycler.h" 28 29 namespace llvm { 30 31 class Value; 32 class Function; 33 class GCModuleInfo; 34 class MachineRegisterInfo; 35 class MachineFrameInfo; 36 class MachineConstantPool; 37 class MachineJumpTableInfo; 38 class MachineModuleInfo; 39 class MCContext; 40 class Pass; 41 class TargetMachine; 42 class TargetSubtargetInfo; 43 class TargetRegisterClass; 44 struct MachinePointerInfo; 45 46 template <> 47 struct ilist_traits<MachineBasicBlock> 48 : public ilist_default_traits<MachineBasicBlock> { 49 mutable ilist_half_node<MachineBasicBlock> Sentinel; 50 public: 51 MachineBasicBlock *createSentinel() const { 52 return static_cast<MachineBasicBlock*>(&Sentinel); 53 } 54 void destroySentinel(MachineBasicBlock *) const {} 55 56 MachineBasicBlock *provideInitialHead() const { return createSentinel(); } 57 MachineBasicBlock *ensureHead(MachineBasicBlock*) const { 58 return createSentinel(); 59 } 60 static void noteHead(MachineBasicBlock*, MachineBasicBlock*) {} 61 62 void addNodeToList(MachineBasicBlock* MBB); 63 void removeNodeFromList(MachineBasicBlock* MBB); 64 void deleteNode(MachineBasicBlock *MBB); 65 private: 66 void createNode(const MachineBasicBlock &); 67 }; 68 69 /// MachineFunctionInfo - This class can be derived from and used by targets to 70 /// hold private target-specific information for each MachineFunction. Objects 71 /// of type are accessed/created with MF::getInfo and destroyed when the 72 /// MachineFunction is destroyed. 73 struct MachineFunctionInfo { 74 virtual ~MachineFunctionInfo(); 75 76 /// \brief Factory function: default behavior is to call new using the 77 /// supplied allocator. 78 /// 79 /// This function can be overridden in a derive class. 80 template<typename Ty> 81 static Ty *create(BumpPtrAllocator &Allocator, MachineFunction &MF) { 82 return new (Allocator.Allocate<Ty>()) Ty(MF); 83 } 84 }; 85 86 class MachineFunction { 87 const Function *Fn; 88 const TargetMachine &Target; 89 const TargetSubtargetInfo *STI; 90 MCContext &Ctx; 91 MachineModuleInfo &MMI; 92 93 // RegInfo - Information about each register in use in the function. 94 MachineRegisterInfo *RegInfo; 95 96 // Used to keep track of target-specific per-machine function information for 97 // the target implementation. 98 MachineFunctionInfo *MFInfo; 99 100 // Keep track of objects allocated on the stack. 101 MachineFrameInfo *FrameInfo; 102 103 // Keep track of constants which are spilled to memory 104 MachineConstantPool *ConstantPool; 105 106 // Keep track of jump tables for switch instructions 107 MachineJumpTableInfo *JumpTableInfo; 108 109 // Function-level unique numbering for MachineBasicBlocks. When a 110 // MachineBasicBlock is inserted into a MachineFunction is it automatically 111 // numbered and this vector keeps track of the mapping from ID's to MBB's. 112 std::vector<MachineBasicBlock*> MBBNumbering; 113 114 // Pool-allocate MachineFunction-lifetime and IR objects. 115 BumpPtrAllocator Allocator; 116 117 // Allocation management for instructions in function. 118 Recycler<MachineInstr> InstructionRecycler; 119 120 // Allocation management for operand arrays on instructions. 121 ArrayRecycler<MachineOperand> OperandRecycler; 122 123 // Allocation management for basic blocks in function. 124 Recycler<MachineBasicBlock> BasicBlockRecycler; 125 126 // List of machine basic blocks in function 127 typedef ilist<MachineBasicBlock> BasicBlockListType; 128 BasicBlockListType BasicBlocks; 129 130 /// FunctionNumber - This provides a unique ID for each function emitted in 131 /// this translation unit. 132 /// 133 unsigned FunctionNumber; 134 135 /// Alignment - The alignment of the function. 136 unsigned Alignment; 137 138 /// ExposesReturnsTwice - True if the function calls setjmp or related 139 /// functions with attribute "returns twice", but doesn't have 140 /// the attribute itself. 141 /// This is used to limit optimizations which cannot reason 142 /// about the control flow of such functions. 143 bool ExposesReturnsTwice; 144 145 /// True if the function includes any inline assembly. 146 bool HasInlineAsm; 147 148 MachineFunction(const MachineFunction &) = delete; 149 void operator=(const MachineFunction&) = delete; 150 public: 151 MachineFunction(const Function *Fn, const TargetMachine &TM, 152 unsigned FunctionNum, MachineModuleInfo &MMI); 153 ~MachineFunction(); 154 155 MachineModuleInfo &getMMI() const { return MMI; } 156 MCContext &getContext() const { return Ctx; } 157 158 /// getFunction - Return the LLVM function that this machine code represents 159 /// 160 const Function *getFunction() const { return Fn; } 161 162 /// getName - Return the name of the corresponding LLVM function. 163 /// 164 StringRef getName() const; 165 166 /// getFunctionNumber - Return a unique ID for the current function. 167 /// 168 unsigned getFunctionNumber() const { return FunctionNumber; } 169 170 /// getTarget - Return the target machine this machine code is compiled with 171 /// 172 const TargetMachine &getTarget() const { return Target; } 173 174 /// getSubtarget - Return the subtarget for which this machine code is being 175 /// compiled. 176 const TargetSubtargetInfo &getSubtarget() const { return *STI; } 177 void setSubtarget(const TargetSubtargetInfo *ST) { STI = ST; } 178 179 /// getSubtarget - This method returns a pointer to the specified type of 180 /// TargetSubtargetInfo. In debug builds, it verifies that the object being 181 /// returned is of the correct type. 182 template<typename STC> const STC &getSubtarget() const { 183 return *static_cast<const STC *>(STI); 184 } 185 186 /// getRegInfo - Return information about the registers currently in use. 187 /// 188 MachineRegisterInfo &getRegInfo() { return *RegInfo; } 189 const MachineRegisterInfo &getRegInfo() const { return *RegInfo; } 190 191 /// getFrameInfo - Return the frame info object for the current function. 192 /// This object contains information about objects allocated on the stack 193 /// frame of the current function in an abstract way. 194 /// 195 MachineFrameInfo *getFrameInfo() { return FrameInfo; } 196 const MachineFrameInfo *getFrameInfo() const { return FrameInfo; } 197 198 /// getJumpTableInfo - Return the jump table info object for the current 199 /// function. This object contains information about jump tables in the 200 /// current function. If the current function has no jump tables, this will 201 /// return null. 202 const MachineJumpTableInfo *getJumpTableInfo() const { return JumpTableInfo; } 203 MachineJumpTableInfo *getJumpTableInfo() { return JumpTableInfo; } 204 205 /// getOrCreateJumpTableInfo - Get the JumpTableInfo for this function, if it 206 /// does already exist, allocate one. 207 MachineJumpTableInfo *getOrCreateJumpTableInfo(unsigned JTEntryKind); 208 209 210 /// getConstantPool - Return the constant pool object for the current 211 /// function. 212 /// 213 MachineConstantPool *getConstantPool() { return ConstantPool; } 214 const MachineConstantPool *getConstantPool() const { return ConstantPool; } 215 216 /// getAlignment - Return the alignment (log2, not bytes) of the function. 217 /// 218 unsigned getAlignment() const { return Alignment; } 219 220 /// setAlignment - Set the alignment (log2, not bytes) of the function. 221 /// 222 void setAlignment(unsigned A) { Alignment = A; } 223 224 /// ensureAlignment - Make sure the function is at least 1 << A bytes aligned. 225 void ensureAlignment(unsigned A) { 226 if (Alignment < A) Alignment = A; 227 } 228 229 /// exposesReturnsTwice - Returns true if the function calls setjmp or 230 /// any other similar functions with attribute "returns twice" without 231 /// having the attribute itself. 232 bool exposesReturnsTwice() const { 233 return ExposesReturnsTwice; 234 } 235 236 /// setCallsSetJmp - Set a flag that indicates if there's a call to 237 /// a "returns twice" function. 238 void setExposesReturnsTwice(bool B) { 239 ExposesReturnsTwice = B; 240 } 241 242 /// Returns true if the function contains any inline assembly. 243 bool hasInlineAsm() const { 244 return HasInlineAsm; 245 } 246 247 /// Set a flag that indicates that the function contains inline assembly. 248 void setHasInlineAsm(bool B) { 249 HasInlineAsm = B; 250 } 251 252 /// getInfo - Keep track of various per-function pieces of information for 253 /// backends that would like to do so. 254 /// 255 template<typename Ty> 256 Ty *getInfo() { 257 if (!MFInfo) 258 MFInfo = Ty::template create<Ty>(Allocator, *this); 259 return static_cast<Ty*>(MFInfo); 260 } 261 262 template<typename Ty> 263 const Ty *getInfo() const { 264 return const_cast<MachineFunction*>(this)->getInfo<Ty>(); 265 } 266 267 /// getBlockNumbered - MachineBasicBlocks are automatically numbered when they 268 /// are inserted into the machine function. The block number for a machine 269 /// basic block can be found by using the MBB::getBlockNumber method, this 270 /// method provides the inverse mapping. 271 /// 272 MachineBasicBlock *getBlockNumbered(unsigned N) const { 273 assert(N < MBBNumbering.size() && "Illegal block number"); 274 assert(MBBNumbering[N] && "Block was removed from the machine function!"); 275 return MBBNumbering[N]; 276 } 277 278 /// Should we be emitting segmented stack stuff for the function 279 bool shouldSplitStack(); 280 281 /// getNumBlockIDs - Return the number of MBB ID's allocated. 282 /// 283 unsigned getNumBlockIDs() const { return (unsigned)MBBNumbering.size(); } 284 285 /// RenumberBlocks - This discards all of the MachineBasicBlock numbers and 286 /// recomputes them. This guarantees that the MBB numbers are sequential, 287 /// dense, and match the ordering of the blocks within the function. If a 288 /// specific MachineBasicBlock is specified, only that block and those after 289 /// it are renumbered. 290 void RenumberBlocks(MachineBasicBlock *MBBFrom = nullptr); 291 292 /// print - Print out the MachineFunction in a format suitable for debugging 293 /// to the specified stream. 294 /// 295 void print(raw_ostream &OS, SlotIndexes* = nullptr) const; 296 297 /// viewCFG - This function is meant for use from the debugger. You can just 298 /// say 'call F->viewCFG()' and a ghostview window should pop up from the 299 /// program, displaying the CFG of the current function with the code for each 300 /// basic block inside. This depends on there being a 'dot' and 'gv' program 301 /// in your path. 302 /// 303 void viewCFG() const; 304 305 /// viewCFGOnly - This function is meant for use from the debugger. It works 306 /// just like viewCFG, but it does not include the contents of basic blocks 307 /// into the nodes, just the label. If you are only interested in the CFG 308 /// this can make the graph smaller. 309 /// 310 void viewCFGOnly() const; 311 312 /// dump - Print the current MachineFunction to cerr, useful for debugger use. 313 /// 314 void dump() const; 315 316 /// verify - Run the current MachineFunction through the machine code 317 /// verifier, useful for debugger use. 318 void verify(Pass *p = nullptr, const char *Banner = nullptr) const; 319 320 // Provide accessors for the MachineBasicBlock list... 321 typedef BasicBlockListType::iterator iterator; 322 typedef BasicBlockListType::const_iterator const_iterator; 323 typedef std::reverse_iterator<const_iterator> const_reverse_iterator; 324 typedef std::reverse_iterator<iterator> reverse_iterator; 325 326 /// addLiveIn - Add the specified physical register as a live-in value and 327 /// create a corresponding virtual register for it. 328 unsigned addLiveIn(unsigned PReg, const TargetRegisterClass *RC); 329 330 //===--------------------------------------------------------------------===// 331 // BasicBlock accessor functions. 332 // 333 iterator begin() { return BasicBlocks.begin(); } 334 const_iterator begin() const { return BasicBlocks.begin(); } 335 iterator end () { return BasicBlocks.end(); } 336 const_iterator end () const { return BasicBlocks.end(); } 337 338 reverse_iterator rbegin() { return BasicBlocks.rbegin(); } 339 const_reverse_iterator rbegin() const { return BasicBlocks.rbegin(); } 340 reverse_iterator rend () { return BasicBlocks.rend(); } 341 const_reverse_iterator rend () const { return BasicBlocks.rend(); } 342 343 unsigned size() const { return (unsigned)BasicBlocks.size();} 344 bool empty() const { return BasicBlocks.empty(); } 345 const MachineBasicBlock &front() const { return BasicBlocks.front(); } 346 MachineBasicBlock &front() { return BasicBlocks.front(); } 347 const MachineBasicBlock & back() const { return BasicBlocks.back(); } 348 MachineBasicBlock & back() { return BasicBlocks.back(); } 349 350 void push_back (MachineBasicBlock *MBB) { BasicBlocks.push_back (MBB); } 351 void push_front(MachineBasicBlock *MBB) { BasicBlocks.push_front(MBB); } 352 void insert(iterator MBBI, MachineBasicBlock *MBB) { 353 BasicBlocks.insert(MBBI, MBB); 354 } 355 void splice(iterator InsertPt, iterator MBBI) { 356 BasicBlocks.splice(InsertPt, BasicBlocks, MBBI); 357 } 358 void splice(iterator InsertPt, iterator MBBI, iterator MBBE) { 359 BasicBlocks.splice(InsertPt, BasicBlocks, MBBI, MBBE); 360 } 361 362 void remove(iterator MBBI) { 363 BasicBlocks.remove(MBBI); 364 } 365 void erase(iterator MBBI) { 366 BasicBlocks.erase(MBBI); 367 } 368 369 //===--------------------------------------------------------------------===// 370 // Internal functions used to automatically number MachineBasicBlocks 371 // 372 373 /// \brief Adds the MBB to the internal numbering. Returns the unique number 374 /// assigned to the MBB. 375 /// 376 unsigned addToMBBNumbering(MachineBasicBlock *MBB) { 377 MBBNumbering.push_back(MBB); 378 return (unsigned)MBBNumbering.size()-1; 379 } 380 381 /// removeFromMBBNumbering - Remove the specific machine basic block from our 382 /// tracker, this is only really to be used by the MachineBasicBlock 383 /// implementation. 384 void removeFromMBBNumbering(unsigned N) { 385 assert(N < MBBNumbering.size() && "Illegal basic block #"); 386 MBBNumbering[N] = nullptr; 387 } 388 389 /// CreateMachineInstr - Allocate a new MachineInstr. Use this instead 390 /// of `new MachineInstr'. 391 /// 392 MachineInstr *CreateMachineInstr(const MCInstrDesc &MCID, 393 DebugLoc DL, 394 bool NoImp = false); 395 396 /// CloneMachineInstr - Create a new MachineInstr which is a copy of the 397 /// 'Orig' instruction, identical in all ways except the instruction 398 /// has no parent, prev, or next. 399 /// 400 /// See also TargetInstrInfo::duplicate() for target-specific fixes to cloned 401 /// instructions. 402 MachineInstr *CloneMachineInstr(const MachineInstr *Orig); 403 404 /// DeleteMachineInstr - Delete the given MachineInstr. 405 /// 406 void DeleteMachineInstr(MachineInstr *MI); 407 408 /// CreateMachineBasicBlock - Allocate a new MachineBasicBlock. Use this 409 /// instead of `new MachineBasicBlock'. 410 /// 411 MachineBasicBlock *CreateMachineBasicBlock(const BasicBlock *bb = nullptr); 412 413 /// DeleteMachineBasicBlock - Delete the given MachineBasicBlock. 414 /// 415 void DeleteMachineBasicBlock(MachineBasicBlock *MBB); 416 417 /// getMachineMemOperand - Allocate a new MachineMemOperand. 418 /// MachineMemOperands are owned by the MachineFunction and need not be 419 /// explicitly deallocated. 420 MachineMemOperand *getMachineMemOperand(MachinePointerInfo PtrInfo, 421 unsigned f, uint64_t s, 422 unsigned base_alignment, 423 const AAMDNodes &AAInfo = AAMDNodes(), 424 const MDNode *Ranges = nullptr); 425 426 /// getMachineMemOperand - Allocate a new MachineMemOperand by copying 427 /// an existing one, adjusting by an offset and using the given size. 428 /// MachineMemOperands are owned by the MachineFunction and need not be 429 /// explicitly deallocated. 430 MachineMemOperand *getMachineMemOperand(const MachineMemOperand *MMO, 431 int64_t Offset, uint64_t Size); 432 433 typedef ArrayRecycler<MachineOperand>::Capacity OperandCapacity; 434 435 /// Allocate an array of MachineOperands. This is only intended for use by 436 /// internal MachineInstr functions. 437 MachineOperand *allocateOperandArray(OperandCapacity Cap) { 438 return OperandRecycler.allocate(Cap, Allocator); 439 } 440 441 /// Dellocate an array of MachineOperands and recycle the memory. This is 442 /// only intended for use by internal MachineInstr functions. 443 /// Cap must be the same capacity that was used to allocate the array. 444 void deallocateOperandArray(OperandCapacity Cap, MachineOperand *Array) { 445 OperandRecycler.deallocate(Cap, Array); 446 } 447 448 /// \brief Allocate and initialize a register mask with @p NumRegister bits. 449 uint32_t *allocateRegisterMask(unsigned NumRegister) { 450 unsigned Size = (NumRegister + 31) / 32; 451 uint32_t *Mask = Allocator.Allocate<uint32_t>(Size); 452 for (unsigned i = 0; i != Size; ++i) 453 Mask[i] = 0; 454 return Mask; 455 } 456 457 /// allocateMemRefsArray - Allocate an array to hold MachineMemOperand 458 /// pointers. This array is owned by the MachineFunction. 459 MachineInstr::mmo_iterator allocateMemRefsArray(unsigned long Num); 460 461 /// extractLoadMemRefs - Allocate an array and populate it with just the 462 /// load information from the given MachineMemOperand sequence. 463 std::pair<MachineInstr::mmo_iterator, 464 MachineInstr::mmo_iterator> 465 extractLoadMemRefs(MachineInstr::mmo_iterator Begin, 466 MachineInstr::mmo_iterator End); 467 468 /// extractStoreMemRefs - Allocate an array and populate it with just the 469 /// store information from the given MachineMemOperand sequence. 470 std::pair<MachineInstr::mmo_iterator, 471 MachineInstr::mmo_iterator> 472 extractStoreMemRefs(MachineInstr::mmo_iterator Begin, 473 MachineInstr::mmo_iterator End); 474 475 //===--------------------------------------------------------------------===// 476 // Label Manipulation. 477 // 478 479 /// getJTISymbol - Return the MCSymbol for the specified non-empty jump table. 480 /// If isLinkerPrivate is specified, an 'l' label is returned, otherwise a 481 /// normal 'L' label is returned. 482 MCSymbol *getJTISymbol(unsigned JTI, MCContext &Ctx, 483 bool isLinkerPrivate = false) const; 484 485 /// getPICBaseSymbol - Return a function-local symbol to represent the PIC 486 /// base. 487 MCSymbol *getPICBaseSymbol() const; 488 }; 489 490 //===--------------------------------------------------------------------===// 491 // GraphTraits specializations for function basic block graphs (CFGs) 492 //===--------------------------------------------------------------------===// 493 494 // Provide specializations of GraphTraits to be able to treat a 495 // machine function as a graph of machine basic blocks... these are 496 // the same as the machine basic block iterators, except that the root 497 // node is implicitly the first node of the function. 498 // 499 template <> struct GraphTraits<MachineFunction*> : 500 public GraphTraits<MachineBasicBlock*> { 501 static NodeType *getEntryNode(MachineFunction *F) { 502 return &F->front(); 503 } 504 505 // nodes_iterator/begin/end - Allow iteration over all nodes in the graph 506 typedef MachineFunction::iterator nodes_iterator; 507 static nodes_iterator nodes_begin(MachineFunction *F) { return F->begin(); } 508 static nodes_iterator nodes_end (MachineFunction *F) { return F->end(); } 509 static unsigned size (MachineFunction *F) { return F->size(); } 510 }; 511 template <> struct GraphTraits<const MachineFunction*> : 512 public GraphTraits<const MachineBasicBlock*> { 513 static NodeType *getEntryNode(const MachineFunction *F) { 514 return &F->front(); 515 } 516 517 // nodes_iterator/begin/end - Allow iteration over all nodes in the graph 518 typedef MachineFunction::const_iterator nodes_iterator; 519 static nodes_iterator nodes_begin(const MachineFunction *F) { 520 return F->begin(); 521 } 522 static nodes_iterator nodes_end (const MachineFunction *F) { 523 return F->end(); 524 } 525 static unsigned size (const MachineFunction *F) { 526 return F->size(); 527 } 528 }; 529 530 531 // Provide specializations of GraphTraits to be able to treat a function as a 532 // graph of basic blocks... and to walk it in inverse order. Inverse order for 533 // a function is considered to be when traversing the predecessor edges of a BB 534 // instead of the successor edges. 535 // 536 template <> struct GraphTraits<Inverse<MachineFunction*> > : 537 public GraphTraits<Inverse<MachineBasicBlock*> > { 538 static NodeType *getEntryNode(Inverse<MachineFunction*> G) { 539 return &G.Graph->front(); 540 } 541 }; 542 template <> struct GraphTraits<Inverse<const MachineFunction*> > : 543 public GraphTraits<Inverse<const MachineBasicBlock*> > { 544 static NodeType *getEntryNode(Inverse<const MachineFunction *> G) { 545 return &G.Graph->front(); 546 } 547 }; 548 549 } // End llvm namespace 550 551 #endif 552
