1 //===-- MachineFunction.cpp -----------------------------------------------===// 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 information for a function. This allows 11 // target-specific information about the generated code to be stored with each 12 // function. 13 // 14 //===----------------------------------------------------------------------===// 15 16 #include "llvm/DerivedTypes.h" 17 #include "llvm/CodeGen/MachineConstantPool.h" 18 #include "llvm/CodeGen/MachineFunctionPass.h" 19 #include "llvm/CodeGen/MachineFrameInfo.h" 20 #include "llvm/CodeGen/MachineInstr.h" 21 #include "llvm/CodeGen/MachineJumpTableInfo.h" 22 #include "llvm/CodeGen/MachineRegisterInfo.h" 23 #include "llvm/CodeGen/Passes.h" 24 #include "llvm/Target/TargetData.h" 25 #include "llvm/Target/TargetMachine.h" 26 #include "llvm/Target/TargetFrameInfo.h" 27 #include "llvm/Function.h" 28 #include "llvm/Instructions.h" 29 #include "llvm/Support/Compiler.h" 30 #include "llvm/Support/GraphWriter.h" 31 #include "llvm/Support/raw_ostream.h" 32 #include "llvm/ADT/STLExtras.h" 33 #include "llvm/Config/config.h" 34 #include <fstream> 35 #include <sstream> 36 using namespace llvm; 37 38 bool MachineFunctionPass::runOnFunction(Function &F) { 39 // Do not codegen any 'available_externally' functions at all, they have 40 // definitions outside the translation unit. 41 if (F.hasAvailableExternallyLinkage()) 42 return false; 43 44 return runOnMachineFunction(MachineFunction::get(&F)); 45 } 46 47 namespace { 48 struct VISIBILITY_HIDDEN Printer : public MachineFunctionPass { 49 static char ID; 50 51 std::ostream *OS; 52 const std::string Banner; 53 54 Printer (std::ostream *os, const std::string &banner) 55 : MachineFunctionPass(&ID), OS(os), Banner(banner) {} 56 57 const char *getPassName() const { return "MachineFunction Printer"; } 58 59 virtual void getAnalysisUsage(AnalysisUsage &AU) const { 60 AU.setPreservesAll(); 61 } 62 63 bool runOnMachineFunction(MachineFunction &MF) { 64 (*OS) << Banner; 65 MF.print (*OS); 66 return false; 67 } 68 }; 69 char Printer::ID = 0; 70 } 71 72 /// Returns a newly-created MachineFunction Printer pass. The default output 73 /// stream is std::cerr; the default banner is empty. 74 /// 75 FunctionPass *llvm::createMachineFunctionPrinterPass(std::ostream *OS, 76 const std::string &Banner){ 77 return new Printer(OS, Banner); 78 } 79 80 namespace { 81 struct VISIBILITY_HIDDEN Deleter : public MachineFunctionPass { 82 static char ID; 83 Deleter() : MachineFunctionPass(&ID) {} 84 85 const char *getPassName() const { return "Machine Code Deleter"; } 86 87 bool runOnMachineFunction(MachineFunction &MF) { 88 // Delete the annotation from the function now. 89 MachineFunction::destruct(MF.getFunction()); 90 return true; 91 } 92 }; 93 char Deleter::ID = 0; 94 } 95 96 /// MachineCodeDeletion Pass - This pass deletes all of the machine code for 97 /// the current function, which should happen after the function has been 98 /// emitted to a .s file or to memory. 99 FunctionPass *llvm::createMachineCodeDeleter() { 100 return new Deleter(); 101 } 102 103 104 105 //===---------------------------------------------------------------------===// 106 // MachineFunction implementation 107 //===---------------------------------------------------------------------===// 108 109 void ilist_traits<MachineBasicBlock>::deleteNode(MachineBasicBlock *MBB) { 110 MBB->getParent()->DeleteMachineBasicBlock(MBB); 111 } 112 113 MachineFunction::MachineFunction(const Function *F, 114 const TargetMachine &TM) 115 : Annotation(AnnotationManager::getID("CodeGen::MachineCodeForFunction")), 116 Fn(F), Target(TM) { 117 if (TM.getRegisterInfo()) 118 RegInfo = new (Allocator.Allocate<MachineRegisterInfo>()) 119 MachineRegisterInfo(*TM.getRegisterInfo()); 120 else 121 RegInfo = 0; 122 MFInfo = 0; 123 FrameInfo = new (Allocator.Allocate<MachineFrameInfo>()) 124 MachineFrameInfo(*TM.getFrameInfo()); 125 ConstantPool = new (Allocator.Allocate<MachineConstantPool>()) 126 MachineConstantPool(TM.getTargetData()); 127 128 // Set up jump table. 129 const TargetData &TD = *TM.getTargetData(); 130 bool IsPic = TM.getRelocationModel() == Reloc::PIC_; 131 unsigned EntrySize = IsPic ? 4 : TD.getPointerSize(); 132 unsigned Alignment = IsPic ? TD.getABITypeAlignment(Type::Int32Ty) 133 : TD.getPointerABIAlignment(); 134 JumpTableInfo = new (Allocator.Allocate<MachineJumpTableInfo>()) 135 MachineJumpTableInfo(EntrySize, Alignment); 136 } 137 138 MachineFunction::~MachineFunction() { 139 BasicBlocks.clear(); 140 InstructionRecycler.clear(Allocator); 141 BasicBlockRecycler.clear(Allocator); 142 if (RegInfo) 143 RegInfo->~MachineRegisterInfo(); Allocator.Deallocate(RegInfo); 144 if (MFInfo) { 145 MFInfo->~MachineFunctionInfo(); Allocator.Deallocate(MFInfo); 146 } 147 FrameInfo->~MachineFrameInfo(); Allocator.Deallocate(FrameInfo); 148 ConstantPool->~MachineConstantPool(); Allocator.Deallocate(ConstantPool); 149 JumpTableInfo->~MachineJumpTableInfo(); Allocator.Deallocate(JumpTableInfo); 150 } 151 152 153 /// RenumberBlocks - This discards all of the MachineBasicBlock numbers and 154 /// recomputes them. This guarantees that the MBB numbers are sequential, 155 /// dense, and match the ordering of the blocks within the function. If a 156 /// specific MachineBasicBlock is specified, only that block and those after 157 /// it are renumbered. 158 void MachineFunction::RenumberBlocks(MachineBasicBlock *MBB) { 159 if (empty()) { MBBNumbering.clear(); return; } 160 MachineFunction::iterator MBBI, E = end(); 161 if (MBB == 0) 162 MBBI = begin(); 163 else 164 MBBI = MBB; 165 166 // Figure out the block number this should have. 167 unsigned BlockNo = 0; 168 if (MBBI != begin()) 169 BlockNo = prior(MBBI)->getNumber()+1; 170 171 for (; MBBI != E; ++MBBI, ++BlockNo) { 172 if (MBBI->getNumber() != (int)BlockNo) { 173 // Remove use of the old number. 174 if (MBBI->getNumber() != -1) { 175 assert(MBBNumbering[MBBI->getNumber()] == &*MBBI && 176 "MBB number mismatch!"); 177 MBBNumbering[MBBI->getNumber()] = 0; 178 } 179 180 // If BlockNo is already taken, set that block's number to -1. 181 if (MBBNumbering[BlockNo]) 182 MBBNumbering[BlockNo]->setNumber(-1); 183 184 MBBNumbering[BlockNo] = MBBI; 185 MBBI->setNumber(BlockNo); 186 } 187 } 188 189 // Okay, all the blocks are renumbered. If we have compactified the block 190 // numbering, shrink MBBNumbering now. 191 assert(BlockNo <= MBBNumbering.size() && "Mismatch!"); 192 MBBNumbering.resize(BlockNo); 193 } 194 195 /// CreateMachineInstr - Allocate a new MachineInstr. Use this instead 196 /// of `new MachineInstr'. 197 /// 198 MachineInstr * 199 MachineFunction::CreateMachineInstr(const TargetInstrDesc &TID, 200 DebugLoc DL, bool NoImp) { 201 return new (InstructionRecycler.Allocate<MachineInstr>(Allocator)) 202 MachineInstr(TID, DL, NoImp); 203 } 204 205 /// CloneMachineInstr - Create a new MachineInstr which is a copy of the 206 /// 'Orig' instruction, identical in all ways except the the instruction 207 /// has no parent, prev, or next. 208 /// 209 MachineInstr * 210 MachineFunction::CloneMachineInstr(const MachineInstr *Orig) { 211 return new (InstructionRecycler.Allocate<MachineInstr>(Allocator)) 212 MachineInstr(*this, *Orig); 213 } 214 215 /// DeleteMachineInstr - Delete the given MachineInstr. 216 /// 217 void 218 MachineFunction::DeleteMachineInstr(MachineInstr *MI) { 219 // Clear the instructions memoperands. This must be done manually because 220 // the instruction's parent pointer is now null, so it can't properly 221 // deallocate them on its own. 222 MI->clearMemOperands(*this); 223 224 MI->~MachineInstr(); 225 InstructionRecycler.Deallocate(Allocator, MI); 226 } 227 228 /// CreateMachineBasicBlock - Allocate a new MachineBasicBlock. Use this 229 /// instead of `new MachineBasicBlock'. 230 /// 231 MachineBasicBlock * 232 MachineFunction::CreateMachineBasicBlock(const BasicBlock *bb) { 233 return new (BasicBlockRecycler.Allocate<MachineBasicBlock>(Allocator)) 234 MachineBasicBlock(*this, bb); 235 } 236 237 /// DeleteMachineBasicBlock - Delete the given MachineBasicBlock. 238 /// 239 void 240 MachineFunction::DeleteMachineBasicBlock(MachineBasicBlock *MBB) { 241 assert(MBB->getParent() == this && "MBB parent mismatch!"); 242 MBB->~MachineBasicBlock(); 243 BasicBlockRecycler.Deallocate(Allocator, MBB); 244 } 245 246 void MachineFunction::dump() const { 247 print(*cerr.stream()); 248 } 249 250 void MachineFunction::print(std::ostream &OS) const { 251 OS << "# Machine code for " << Fn->getName () << "():\n"; 252 253 // Print Frame Information 254 FrameInfo->print(*this, OS); 255 256 // Print JumpTable Information 257 JumpTableInfo->print(OS); 258 259 // Print Constant Pool 260 { 261 raw_os_ostream OSS(OS); 262 ConstantPool->print(OSS); 263 } 264 265 const TargetRegisterInfo *TRI = getTarget().getRegisterInfo(); 266 267 if (RegInfo && !RegInfo->livein_empty()) { 268 OS << "Live Ins:"; 269 for (MachineRegisterInfo::livein_iterator 270 I = RegInfo->livein_begin(), E = RegInfo->livein_end(); I != E; ++I) { 271 if (TRI) 272 OS << " " << TRI->getName(I->first); 273 else 274 OS << " Reg #" << I->first; 275 276 if (I->second) 277 OS << " in VR#" << I->second << " "; 278 } 279 OS << "\n"; 280 } 281 if (RegInfo && !RegInfo->liveout_empty()) { 282 OS << "Live Outs:"; 283 for (MachineRegisterInfo::liveout_iterator 284 I = RegInfo->liveout_begin(), E = RegInfo->liveout_end(); I != E; ++I) 285 if (TRI) 286 OS << " " << TRI->getName(*I); 287 else 288 OS << " Reg #" << *I; 289 OS << "\n"; 290 } 291 292 for (const_iterator BB = begin(); BB != end(); ++BB) 293 BB->print(OS); 294 295 OS << "\n# End machine code for " << Fn->getName () << "().\n\n"; 296 } 297 298 /// CFGOnly flag - This is used to control whether or not the CFG graph printer 299 /// prints out the contents of basic blocks or not. This is acceptable because 300 /// this code is only really used for debugging purposes. 301 /// 302 static bool CFGOnly = false; 303 304 namespace llvm { 305 template<> 306 struct DOTGraphTraits<const MachineFunction*> : public DefaultDOTGraphTraits { 307 static std::string getGraphName(const MachineFunction *F) { 308 return "CFG for '" + F->getFunction()->getName() + "' function"; 309 } 310 311 static std::string getNodeLabel(const MachineBasicBlock *Node, 312 const MachineFunction *Graph) { 313 if (CFGOnly && Node->getBasicBlock() && 314 !Node->getBasicBlock()->getName().empty()) 315 return Node->getBasicBlock()->getName() + ":"; 316 317 std::ostringstream Out; 318 if (CFGOnly) { 319 Out << Node->getNumber() << ':'; 320 return Out.str(); 321 } 322 323 Node->print(Out); 324 325 std::string OutStr = Out.str(); 326 if (OutStr[0] == '\n') OutStr.erase(OutStr.begin()); 327 328 // Process string output to make it nicer... 329 for (unsigned i = 0; i != OutStr.length(); ++i) 330 if (OutStr[i] == '\n') { // Left justify 331 OutStr[i] = '\\'; 332 OutStr.insert(OutStr.begin()+i+1, 'l'); 333 } 334 return OutStr; 335 } 336 }; 337 } 338 339 void MachineFunction::viewCFG() const 340 { 341 #ifndef NDEBUG 342 ViewGraph(this, "mf" + getFunction()->getName()); 343 #else 344 cerr << "SelectionDAG::viewGraph is only available in debug builds on " 345 << "systems with Graphviz or gv!\n"; 346 #endif // NDEBUG 347 } 348 349 void MachineFunction::viewCFGOnly() const 350 { 351 CFGOnly = true; 352 viewCFG(); 353 CFGOnly = false; 354 } 355 356 // The next two methods are used to construct and to retrieve 357 // the MachineCodeForFunction object for the given function. 358 // construct() -- Allocates and initializes for a given function and target 359 // get() -- Returns a handle to the object. 360 // This should not be called before "construct()" 361 // for a given Function. 362 // 363 MachineFunction& 364 MachineFunction::construct(const Function *Fn, const TargetMachine &Tar) 365 { 366 AnnotationID MF_AID = 367 AnnotationManager::getID("CodeGen::MachineCodeForFunction"); 368 assert(Fn->getAnnotation(MF_AID) == 0 && 369 "Object already exists for this function!"); 370 MachineFunction* mcInfo = new MachineFunction(Fn, Tar); 371 Fn->addAnnotation(mcInfo); 372 return *mcInfo; 373 } 374 375 void MachineFunction::destruct(const Function *Fn) { 376 AnnotationID MF_AID = 377 AnnotationManager::getID("CodeGen::MachineCodeForFunction"); 378 bool Deleted = Fn->deleteAnnotation(MF_AID); 379 assert(Deleted && "Machine code did not exist for function!"); 380 Deleted = Deleted; // silence warning when no assertions. 381 } 382 383 MachineFunction& MachineFunction::get(const Function *F) 384 { 385 AnnotationID MF_AID = 386 AnnotationManager::getID("CodeGen::MachineCodeForFunction"); 387 MachineFunction *mc = (MachineFunction*)F->getAnnotation(MF_AID); 388 assert(mc && "Call construct() method first to allocate the object"); 389 return *mc; 390 } 391 392 /// addLiveIn - Add the specified physical register as a live-in value and 393 /// create a corresponding virtual register for it. 394 unsigned MachineFunction::addLiveIn(unsigned PReg, 395 const TargetRegisterClass *RC) { 396 assert(RC->contains(PReg) && "Not the correct regclass!"); 397 unsigned VReg = getRegInfo().createVirtualRegister(RC); 398 getRegInfo().addLiveIn(PReg, VReg); 399 return VReg; 400 } 401 402 /// getOrCreateDebugLocID - Look up the DebugLocTuple index with the given 403 /// source file, line, and column. If none currently exists, create a new 404 /// DebugLocTuple, and insert it into the DebugIdMap. 405 unsigned MachineFunction::getOrCreateDebugLocID(GlobalVariable *CompileUnit, 406 DebugScope Scope, 407 unsigned Line, unsigned Col) { 408 DebugLocTuple Tuple(CompileUnit, Scope, Line, Col); 409 DenseMap<DebugLocTuple, unsigned>::iterator II 410 = DebugLocInfo.DebugIdMap.find(Tuple); 411 if (II != DebugLocInfo.DebugIdMap.end()) 412 return II->second; 413 // Add a new tuple. 414 unsigned Id = DebugLocInfo.DebugLocations.size(); 415 DebugLocInfo.DebugLocations.push_back(Tuple); 416 DebugLocInfo.DebugIdMap[Tuple] = Id; 417 return Id; 418 } 419 420 /// getDebugLocTuple - Get the DebugLocTuple for a given DebugLoc object. 421 DebugLocTuple MachineFunction::getDebugLocTuple(DebugLoc DL) const { 422 unsigned Idx = DL.getIndex(); 423 assert(Idx < DebugLocInfo.DebugLocations.size() && 424 "Invalid index into debug locations!"); 425 return DebugLocInfo.DebugLocations[Idx]; 426 } 427 428 /// CreateDebugScope - Create a new debug scope. 429 DebugScope MachineFunction::CreateDebugScope(GlobalVariable *ScopeGV, 430 DebugScope Parent) { 431 DbgScopeInfos.push_back(DebugScopeInfo(ScopeGV, Parent)); 432 return DebugScope::get(DbgScopeInfos.size() - 1); 433 } 434 435 /// getDebugScopeInfo - Get the DebugScopeInfo for a given DebugScope object. 436 const DebugScopeInfo &MachineFunction::getDebugScopeInfo(DebugScope DS) const { 437 unsigned Idx = DS.getIndex(); 438 assert(Idx < DbgScopeInfos.size() && "Invalid index into debug scopes!"); 439 return DbgScopeInfos[Idx]; 440 } 441 442 443 //===----------------------------------------------------------------------===// 444 // MachineFrameInfo implementation 445 //===----------------------------------------------------------------------===// 446 447 /// CreateFixedObject - Create a new object at a fixed location on the stack. 448 /// All fixed objects should be created before other objects are created for 449 /// efficiency. By default, fixed objects are immutable. This returns an 450 /// index with a negative value. 451 /// 452 int MachineFrameInfo::CreateFixedObject(uint64_t Size, int64_t SPOffset, 453 bool Immutable) { 454 assert(Size != 0 && "Cannot allocate zero size fixed stack objects!"); 455 Objects.insert(Objects.begin(), StackObject(Size, 1, SPOffset, Immutable)); 456 return -++NumFixedObjects; 457 } 458 459 460 void MachineFrameInfo::print(const MachineFunction &MF, std::ostream &OS) const{ 461 const TargetFrameInfo *FI = MF.getTarget().getFrameInfo(); 462 int ValOffset = (FI ? FI->getOffsetOfLocalArea() : 0); 463 464 for (unsigned i = 0, e = Objects.size(); i != e; ++i) { 465 const StackObject &SO = Objects[i]; 466 OS << " <fi#" << (int)(i-NumFixedObjects) << ">: "; 467 if (SO.Size == ~0ULL) { 468 OS << "dead\n"; 469 continue; 470 } 471 if (SO.Size == 0) 472 OS << "variable sized"; 473 else 474 OS << "size is " << SO.Size << " byte" << (SO.Size != 1 ? "s," : ","); 475 OS << " alignment is " << SO.Alignment << " byte" 476 << (SO.Alignment != 1 ? "s," : ","); 477 478 if (i < NumFixedObjects) 479 OS << " fixed"; 480 if (i < NumFixedObjects || SO.SPOffset != -1) { 481 int64_t Off = SO.SPOffset - ValOffset; 482 OS << " at location [SP"; 483 if (Off > 0) 484 OS << "+" << Off; 485 else if (Off < 0) 486 OS << Off; 487 OS << "]"; 488 } 489 OS << "\n"; 490 } 491 492 if (HasVarSizedObjects) 493 OS << " Stack frame contains variable sized objects\n"; 494 } 495 496 void MachineFrameInfo::dump(const MachineFunction &MF) const { 497 print(MF, *cerr.stream()); 498 } 499 500 501 //===----------------------------------------------------------------------===// 502 // MachineJumpTableInfo implementation 503 //===----------------------------------------------------------------------===// 504 505 /// getJumpTableIndex - Create a new jump table entry in the jump table info 506 /// or return an existing one. 507 /// 508 unsigned MachineJumpTableInfo::getJumpTableIndex( 509 const std::vector<MachineBasicBlock*> &DestBBs) { 510 assert(!DestBBs.empty() && "Cannot create an empty jump table!"); 511 for (unsigned i = 0, e = JumpTables.size(); i != e; ++i) 512 if (JumpTables[i].MBBs == DestBBs) 513 return i; 514 515 JumpTables.push_back(MachineJumpTableEntry(DestBBs)); 516 return JumpTables.size()-1; 517 } 518 519 /// ReplaceMBBInJumpTables - If Old is the target of any jump tables, update 520 /// the jump tables to branch to New instead. 521 bool 522 MachineJumpTableInfo::ReplaceMBBInJumpTables(MachineBasicBlock *Old, 523 MachineBasicBlock *New) { 524 assert(Old != New && "Not making a change?"); 525 bool MadeChange = false; 526 for (size_t i = 0, e = JumpTables.size(); i != e; ++i) { 527 MachineJumpTableEntry &JTE = JumpTables[i]; 528 for (size_t j = 0, e = JTE.MBBs.size(); j != e; ++j) 529 if (JTE.MBBs[j] == Old) { 530 JTE.MBBs[j] = New; 531 MadeChange = true; 532 } 533 } 534 return MadeChange; 535 } 536 537 void MachineJumpTableInfo::print(std::ostream &OS) const { 538 // FIXME: this is lame, maybe we could print out the MBB numbers or something 539 // like {1, 2, 4, 5, 3, 0} 540 for (unsigned i = 0, e = JumpTables.size(); i != e; ++i) { 541 OS << " <jt#" << i << "> has " << JumpTables[i].MBBs.size() 542 << " entries\n"; 543 } 544 } 545 546 void MachineJumpTableInfo::dump() const { print(*cerr.stream()); } 547 548 549 //===----------------------------------------------------------------------===// 550 // MachineConstantPool implementation 551 //===----------------------------------------------------------------------===// 552 553 const Type *MachineConstantPoolEntry::getType() const { 554 if (isMachineConstantPoolEntry()) 555 return Val.MachineCPVal->getType(); 556 return Val.ConstVal->getType(); 557 } 558 559 MachineConstantPool::~MachineConstantPool() { 560 for (unsigned i = 0, e = Constants.size(); i != e; ++i) 561 if (Constants[i].isMachineConstantPoolEntry()) 562 delete Constants[i].Val.MachineCPVal; 563 } 564 565 /// getConstantPoolIndex - Create a new entry in the constant pool or return 566 /// an existing one. User must specify the log2 of the minimum required 567 /// alignment for the object. 568 /// 569 unsigned MachineConstantPool::getConstantPoolIndex(Constant *C, 570 unsigned Alignment) { 571 assert(Alignment && "Alignment must be specified!"); 572 if (Alignment > PoolAlignment) PoolAlignment = Alignment; 573 574 // Check to see if we already have this constant. 575 // 576 // FIXME, this could be made much more efficient for large constant pools. 577 for (unsigned i = 0, e = Constants.size(); i != e; ++i) 578 if (Constants[i].Val.ConstVal == C && 579 (Constants[i].getAlignment() & (Alignment - 1)) == 0) 580 return i; 581 582 Constants.push_back(MachineConstantPoolEntry(C, Alignment)); 583 return Constants.size()-1; 584 } 585 586 unsigned MachineConstantPool::getConstantPoolIndex(MachineConstantPoolValue *V, 587 unsigned Alignment) { 588 assert(Alignment && "Alignment must be specified!"); 589 if (Alignment > PoolAlignment) PoolAlignment = Alignment; 590 591 // Check to see if we already have this constant. 592 // 593 // FIXME, this could be made much more efficient for large constant pools. 594 int Idx = V->getExistingMachineCPValue(this, Alignment); 595 if (Idx != -1) 596 return (unsigned)Idx; 597 598 Constants.push_back(MachineConstantPoolEntry(V, Alignment)); 599 return Constants.size()-1; 600 } 601 602 void MachineConstantPool::print(raw_ostream &OS) const { 603 for (unsigned i = 0, e = Constants.size(); i != e; ++i) { 604 OS << " <cp#" << i << "> is"; 605 if (Constants[i].isMachineConstantPoolEntry()) 606 Constants[i].Val.MachineCPVal->print(OS); 607 else 608 OS << *(Value*)Constants[i].Val.ConstVal; 609 OS << " , alignment=" << Constants[i].getAlignment(); 610 OS << "\n"; 611 } 612 } 613 614 void MachineConstantPool::dump() const { print(errs()); } 615