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/Function.h" 18 #include "llvm/Instructions.h" 19 #include "llvm/ADT/STLExtras.h" 20 #include "llvm/Config/config.h" 21 #include "llvm/CodeGen/MachineConstantPool.h" 22 #include "llvm/CodeGen/MachineFunctionPass.h" 23 #include "llvm/CodeGen/MachineFrameInfo.h" 24 #include "llvm/CodeGen/MachineInstr.h" 25 #include "llvm/CodeGen/MachineJumpTableInfo.h" 26 #include "llvm/CodeGen/MachineRegisterInfo.h" 27 #include "llvm/CodeGen/Passes.h" 28 #include "llvm/Target/TargetData.h" 29 #include "llvm/Target/TargetLowering.h" 30 #include "llvm/Target/TargetMachine.h" 31 #include "llvm/Target/TargetFrameInfo.h" 32 #include "llvm/Support/Compiler.h" 33 #include "llvm/Support/GraphWriter.h" 34 #include "llvm/Support/raw_ostream.h" 35 #include <fstream> 36 #include <sstream> 37 using namespace llvm; 38 39 namespace { 40 struct VISIBILITY_HIDDEN Printer : public MachineFunctionPass { 41 static char ID; 42 43 std::ostream *OS; 44 const std::string Banner; 45 46 Printer (std::ostream *os, const std::string &banner) 47 : MachineFunctionPass(&ID), OS(os), Banner(banner) {} 48 49 const char *getPassName() const { return "MachineFunction Printer"; } 50 51 virtual void getAnalysisUsage(AnalysisUsage &AU) const { 52 AU.setPreservesAll(); 53 MachineFunctionPass::getAnalysisUsage(AU); 54 } 55 56 bool runOnMachineFunction(MachineFunction &MF) { 57 (*OS) << Banner; 58 MF.print (*OS); 59 return false; 60 } 61 }; 62 char Printer::ID = 0; 63 } 64 65 /// Returns a newly-created MachineFunction Printer pass. The default banner is 66 /// empty. 67 /// 68 FunctionPass *llvm::createMachineFunctionPrinterPass(std::ostream *OS, 69 const std::string &Banner){ 70 return new Printer(OS, Banner); 71 } 72 73 //===---------------------------------------------------------------------===// 74 // MachineFunction implementation 75 //===---------------------------------------------------------------------===// 76 77 void ilist_traits<MachineBasicBlock>::deleteNode(MachineBasicBlock *MBB) { 78 MBB->getParent()->DeleteMachineBasicBlock(MBB); 79 } 80 81 MachineFunction::MachineFunction(Function *F, 82 const TargetMachine &TM) 83 : Fn(F), Target(TM) { 84 if (TM.getRegisterInfo()) 85 RegInfo = new (Allocator.Allocate<MachineRegisterInfo>()) 86 MachineRegisterInfo(*TM.getRegisterInfo()); 87 else 88 RegInfo = 0; 89 MFInfo = 0; 90 FrameInfo = new (Allocator.Allocate<MachineFrameInfo>()) 91 MachineFrameInfo(*TM.getFrameInfo()); 92 ConstantPool = new (Allocator.Allocate<MachineConstantPool>()) 93 MachineConstantPool(TM.getTargetData()); 94 Alignment = TM.getTargetLowering()->getFunctionAlignment(F); 95 96 // Set up jump table. 97 const TargetData &TD = *TM.getTargetData(); 98 bool IsPic = TM.getRelocationModel() == Reloc::PIC_; 99 unsigned EntrySize = IsPic ? 4 : TD.getPointerSize(); 100 unsigned TyAlignment = IsPic ? 101 TD.getABITypeAlignment(Type::getInt32Ty(F->getContext())) 102 : TD.getPointerABIAlignment(); 103 JumpTableInfo = new (Allocator.Allocate<MachineJumpTableInfo>()) 104 MachineJumpTableInfo(EntrySize, TyAlignment); 105 } 106 107 MachineFunction::~MachineFunction() { 108 BasicBlocks.clear(); 109 InstructionRecycler.clear(Allocator); 110 BasicBlockRecycler.clear(Allocator); 111 if (RegInfo) { 112 RegInfo->~MachineRegisterInfo(); 113 Allocator.Deallocate(RegInfo); 114 } 115 if (MFInfo) { 116 MFInfo->~MachineFunctionInfo(); 117 Allocator.Deallocate(MFInfo); 118 } 119 FrameInfo->~MachineFrameInfo(); Allocator.Deallocate(FrameInfo); 120 ConstantPool->~MachineConstantPool(); Allocator.Deallocate(ConstantPool); 121 JumpTableInfo->~MachineJumpTableInfo(); Allocator.Deallocate(JumpTableInfo); 122 } 123 124 125 /// RenumberBlocks - This discards all of the MachineBasicBlock numbers and 126 /// recomputes them. This guarantees that the MBB numbers are sequential, 127 /// dense, and match the ordering of the blocks within the function. If a 128 /// specific MachineBasicBlock is specified, only that block and those after 129 /// it are renumbered. 130 void MachineFunction::RenumberBlocks(MachineBasicBlock *MBB) { 131 if (empty()) { MBBNumbering.clear(); return; } 132 MachineFunction::iterator MBBI, E = end(); 133 if (MBB == 0) 134 MBBI = begin(); 135 else 136 MBBI = MBB; 137 138 // Figure out the block number this should have. 139 unsigned BlockNo = 0; 140 if (MBBI != begin()) 141 BlockNo = prior(MBBI)->getNumber()+1; 142 143 for (; MBBI != E; ++MBBI, ++BlockNo) { 144 if (MBBI->getNumber() != (int)BlockNo) { 145 // Remove use of the old number. 146 if (MBBI->getNumber() != -1) { 147 assert(MBBNumbering[MBBI->getNumber()] == &*MBBI && 148 "MBB number mismatch!"); 149 MBBNumbering[MBBI->getNumber()] = 0; 150 } 151 152 // If BlockNo is already taken, set that block's number to -1. 153 if (MBBNumbering[BlockNo]) 154 MBBNumbering[BlockNo]->setNumber(-1); 155 156 MBBNumbering[BlockNo] = MBBI; 157 MBBI->setNumber(BlockNo); 158 } 159 } 160 161 // Okay, all the blocks are renumbered. If we have compactified the block 162 // numbering, shrink MBBNumbering now. 163 assert(BlockNo <= MBBNumbering.size() && "Mismatch!"); 164 MBBNumbering.resize(BlockNo); 165 } 166 167 /// CreateMachineInstr - Allocate a new MachineInstr. Use this instead 168 /// of `new MachineInstr'. 169 /// 170 MachineInstr * 171 MachineFunction::CreateMachineInstr(const TargetInstrDesc &TID, 172 DebugLoc DL, bool NoImp) { 173 return new (InstructionRecycler.Allocate<MachineInstr>(Allocator)) 174 MachineInstr(TID, DL, NoImp); 175 } 176 177 /// CloneMachineInstr - Create a new MachineInstr which is a copy of the 178 /// 'Orig' instruction, identical in all ways except the the instruction 179 /// has no parent, prev, or next. 180 /// 181 MachineInstr * 182 MachineFunction::CloneMachineInstr(const MachineInstr *Orig) { 183 return new (InstructionRecycler.Allocate<MachineInstr>(Allocator)) 184 MachineInstr(*this, *Orig); 185 } 186 187 /// DeleteMachineInstr - Delete the given MachineInstr. 188 /// 189 void 190 MachineFunction::DeleteMachineInstr(MachineInstr *MI) { 191 // Clear the instructions memoperands. This must be done manually because 192 // the instruction's parent pointer is now null, so it can't properly 193 // deallocate them on its own. 194 MI->clearMemOperands(*this); 195 196 MI->~MachineInstr(); 197 InstructionRecycler.Deallocate(Allocator, MI); 198 } 199 200 /// CreateMachineBasicBlock - Allocate a new MachineBasicBlock. Use this 201 /// instead of `new MachineBasicBlock'. 202 /// 203 MachineBasicBlock * 204 MachineFunction::CreateMachineBasicBlock(const BasicBlock *bb) { 205 return new (BasicBlockRecycler.Allocate<MachineBasicBlock>(Allocator)) 206 MachineBasicBlock(*this, bb); 207 } 208 209 /// DeleteMachineBasicBlock - Delete the given MachineBasicBlock. 210 /// 211 void 212 MachineFunction::DeleteMachineBasicBlock(MachineBasicBlock *MBB) { 213 assert(MBB->getParent() == this && "MBB parent mismatch!"); 214 MBB->~MachineBasicBlock(); 215 BasicBlockRecycler.Deallocate(Allocator, MBB); 216 } 217 218 void MachineFunction::dump() const { 219 print(*cerr.stream()); 220 } 221 222 void MachineFunction::print(std::ostream &OS, 223 const PrefixPrinter &prefix) const { 224 OS << "# Machine code for " << Fn->getNameStr () << "():\n"; 225 226 // Print Frame Information 227 FrameInfo->print(*this, OS); 228 229 // Print JumpTable Information 230 JumpTableInfo->print(OS); 231 232 // Print Constant Pool 233 { 234 raw_os_ostream OSS(OS); 235 ConstantPool->print(OSS); 236 } 237 238 const TargetRegisterInfo *TRI = getTarget().getRegisterInfo(); 239 240 if (RegInfo && !RegInfo->livein_empty()) { 241 OS << "Live Ins:"; 242 for (MachineRegisterInfo::livein_iterator 243 I = RegInfo->livein_begin(), E = RegInfo->livein_end(); I != E; ++I) { 244 if (TRI) 245 OS << " " << TRI->getName(I->first); 246 else 247 OS << " Reg #" << I->first; 248 249 if (I->second) 250 OS << " in VR#" << I->second << " "; 251 } 252 OS << "\n"; 253 } 254 if (RegInfo && !RegInfo->liveout_empty()) { 255 OS << "Live Outs:"; 256 for (MachineRegisterInfo::liveout_iterator 257 I = RegInfo->liveout_begin(), E = RegInfo->liveout_end(); I != E; ++I) 258 if (TRI) 259 OS << " " << TRI->getName(*I); 260 else 261 OS << " Reg #" << *I; 262 OS << "\n"; 263 } 264 265 for (const_iterator BB = begin(); BB != end(); ++BB) { 266 prefix(OS, *BB); 267 BB->print(OS, prefix); 268 } 269 270 OS << "\n# End machine code for " << Fn->getNameStr () << "().\n\n"; 271 } 272 273 namespace llvm { 274 template<> 275 struct DOTGraphTraits<const MachineFunction*> : public DefaultDOTGraphTraits { 276 static std::string getGraphName(const MachineFunction *F) { 277 return "CFG for '" + F->getFunction()->getNameStr() + "' function"; 278 } 279 280 static std::string getNodeLabel(const MachineBasicBlock *Node, 281 const MachineFunction *Graph, 282 bool ShortNames) { 283 if (ShortNames && Node->getBasicBlock() && 284 !Node->getBasicBlock()->getName().empty()) 285 return Node->getBasicBlock()->getNameStr() + ":"; 286 287 std::ostringstream Out; 288 if (ShortNames) { 289 Out << Node->getNumber() << ':'; 290 return Out.str(); 291 } 292 293 Node->print(Out); 294 295 std::string OutStr = Out.str(); 296 if (OutStr[0] == '\n') OutStr.erase(OutStr.begin()); 297 298 // Process string output to make it nicer... 299 for (unsigned i = 0; i != OutStr.length(); ++i) 300 if (OutStr[i] == '\n') { // Left justify 301 OutStr[i] = '\\'; 302 OutStr.insert(OutStr.begin()+i+1, 'l'); 303 } 304 return OutStr; 305 } 306 }; 307 } 308 309 void MachineFunction::viewCFG() const 310 { 311 #ifndef NDEBUG 312 ViewGraph(this, "mf" + getFunction()->getNameStr()); 313 #else 314 cerr << "SelectionDAG::viewGraph is only available in debug builds on " 315 << "systems with Graphviz or gv!\n"; 316 #endif // NDEBUG 317 } 318 319 void MachineFunction::viewCFGOnly() const 320 { 321 #ifndef NDEBUG 322 ViewGraph(this, "mf" + getFunction()->getNameStr(), true); 323 #else 324 cerr << "SelectionDAG::viewGraph is only available in debug builds on " 325 << "systems with Graphviz or gv!\n"; 326 #endif // NDEBUG 327 } 328 329 /// addLiveIn - Add the specified physical register as a live-in value and 330 /// create a corresponding virtual register for it. 331 unsigned MachineFunction::addLiveIn(unsigned PReg, 332 const TargetRegisterClass *RC) { 333 assert(RC->contains(PReg) && "Not the correct regclass!"); 334 unsigned VReg = getRegInfo().createVirtualRegister(RC); 335 getRegInfo().addLiveIn(PReg, VReg); 336 return VReg; 337 } 338 339 /// getOrCreateDebugLocID - Look up the DebugLocTuple index with the given 340 /// source file, line, and column. If none currently exists, create a new 341 /// DebugLocTuple, and insert it into the DebugIdMap. 342 unsigned MachineFunction::getOrCreateDebugLocID(GlobalVariable *CompileUnit, 343 unsigned Line, unsigned Col) { 344 DebugLocTuple Tuple(CompileUnit, Line, Col); 345 DenseMap<DebugLocTuple, unsigned>::iterator II 346 = DebugLocInfo.DebugIdMap.find(Tuple); 347 if (II != DebugLocInfo.DebugIdMap.end()) 348 return II->second; 349 // Add a new tuple. 350 unsigned Id = DebugLocInfo.DebugLocations.size(); 351 DebugLocInfo.DebugLocations.push_back(Tuple); 352 DebugLocInfo.DebugIdMap[Tuple] = Id; 353 return Id; 354 } 355 356 /// getDebugLocTuple - Get the DebugLocTuple for a given DebugLoc object. 357 DebugLocTuple MachineFunction::getDebugLocTuple(DebugLoc DL) const { 358 unsigned Idx = DL.getIndex(); 359 assert(Idx < DebugLocInfo.DebugLocations.size() && 360 "Invalid index into debug locations!"); 361 return DebugLocInfo.DebugLocations[Idx]; 362 } 363 364 //===----------------------------------------------------------------------===// 365 // MachineFrameInfo implementation 366 //===----------------------------------------------------------------------===// 367 368 /// CreateFixedObject - Create a new object at a fixed location on the stack. 369 /// All fixed objects should be created before other objects are created for 370 /// efficiency. By default, fixed objects are immutable. This returns an 371 /// index with a negative value. 372 /// 373 int MachineFrameInfo::CreateFixedObject(uint64_t Size, int64_t SPOffset, 374 bool Immutable) { 375 assert(Size != 0 && "Cannot allocate zero size fixed stack objects!"); 376 Objects.insert(Objects.begin(), StackObject(Size, 1, SPOffset, Immutable)); 377 return -++NumFixedObjects; 378 } 379 380 381 BitVector 382 MachineFrameInfo::getPristineRegs(const MachineBasicBlock *MBB) const { 383 assert(MBB && "MBB must be valid"); 384 const MachineFunction *MF = MBB->getParent(); 385 assert(MF && "MBB must be part of a MachineFunction"); 386 const TargetMachine &TM = MF->getTarget(); 387 const TargetRegisterInfo *TRI = TM.getRegisterInfo(); 388 BitVector BV(TRI->getNumRegs()); 389 390 // Before CSI is calculated, no registers are considered pristine. They can be 391 // freely used and PEI will make sure they are saved. 392 if (!isCalleeSavedInfoValid()) 393 return BV; 394 395 for (const unsigned *CSR = TRI->getCalleeSavedRegs(MF); CSR && *CSR; ++CSR) 396 BV.set(*CSR); 397 398 // The entry MBB always has all CSRs pristine. 399 if (MBB == &MF->front()) 400 return BV; 401 402 // On other MBBs the saved CSRs are not pristine. 403 const std::vector<CalleeSavedInfo> &CSI = getCalleeSavedInfo(); 404 for (std::vector<CalleeSavedInfo>::const_iterator I = CSI.begin(), 405 E = CSI.end(); I != E; ++I) 406 BV.reset(I->getReg()); 407 408 return BV; 409 } 410 411 412 void MachineFrameInfo::print(const MachineFunction &MF, std::ostream &OS) const{ 413 const TargetFrameInfo *FI = MF.getTarget().getFrameInfo(); 414 int ValOffset = (FI ? FI->getOffsetOfLocalArea() : 0); 415 416 for (unsigned i = 0, e = Objects.size(); i != e; ++i) { 417 const StackObject &SO = Objects[i]; 418 OS << " <fi#" << (int)(i-NumFixedObjects) << ">: "; 419 if (SO.Size == ~0ULL) { 420 OS << "dead\n"; 421 continue; 422 } 423 if (SO.Size == 0) 424 OS << "variable sized"; 425 else 426 OS << "size is " << SO.Size << " byte" << (SO.Size != 1 ? "s," : ","); 427 OS << " alignment is " << SO.Alignment << " byte" 428 << (SO.Alignment != 1 ? "s," : ","); 429 430 if (i < NumFixedObjects) 431 OS << " fixed"; 432 if (i < NumFixedObjects || SO.SPOffset != -1) { 433 int64_t Off = SO.SPOffset - ValOffset; 434 OS << " at location [SP"; 435 if (Off > 0) 436 OS << "+" << Off; 437 else if (Off < 0) 438 OS << Off; 439 OS << "]"; 440 } 441 OS << "\n"; 442 } 443 444 if (HasVarSizedObjects) 445 OS << " Stack frame contains variable sized objects\n"; 446 } 447 448 void MachineFrameInfo::dump(const MachineFunction &MF) const { 449 print(MF, *cerr.stream()); 450 } 451 452 //===----------------------------------------------------------------------===// 453 // MachineJumpTableInfo implementation 454 //===----------------------------------------------------------------------===// 455 456 /// getJumpTableIndex - Create a new jump table entry in the jump table info 457 /// or return an existing one. 458 /// 459 unsigned MachineJumpTableInfo::getJumpTableIndex( 460 const std::vector<MachineBasicBlock*> &DestBBs) { 461 assert(!DestBBs.empty() && "Cannot create an empty jump table!"); 462 for (unsigned i = 0, e = JumpTables.size(); i != e; ++i) 463 if (JumpTables[i].MBBs == DestBBs) 464 return i; 465 466 JumpTables.push_back(MachineJumpTableEntry(DestBBs)); 467 return JumpTables.size()-1; 468 } 469 470 /// ReplaceMBBInJumpTables - If Old is the target of any jump tables, update 471 /// the jump tables to branch to New instead. 472 bool 473 MachineJumpTableInfo::ReplaceMBBInJumpTables(MachineBasicBlock *Old, 474 MachineBasicBlock *New) { 475 assert(Old != New && "Not making a change?"); 476 bool MadeChange = false; 477 for (size_t i = 0, e = JumpTables.size(); i != e; ++i) { 478 MachineJumpTableEntry &JTE = JumpTables[i]; 479 for (size_t j = 0, e = JTE.MBBs.size(); j != e; ++j) 480 if (JTE.MBBs[j] == Old) { 481 JTE.MBBs[j] = New; 482 MadeChange = true; 483 } 484 } 485 return MadeChange; 486 } 487 488 void MachineJumpTableInfo::print(std::ostream &OS) const { 489 // FIXME: this is lame, maybe we could print out the MBB numbers or something 490 // like {1, 2, 4, 5, 3, 0} 491 for (unsigned i = 0, e = JumpTables.size(); i != e; ++i) { 492 OS << " <jt#" << i << "> has " << JumpTables[i].MBBs.size() 493 << " entries\n"; 494 } 495 } 496 497 void MachineJumpTableInfo::dump() const { print(*cerr.stream()); } 498 499 500 //===----------------------------------------------------------------------===// 501 // MachineConstantPool implementation 502 //===----------------------------------------------------------------------===// 503 504 const Type *MachineConstantPoolEntry::getType() const { 505 if (isMachineConstantPoolEntry()) 506 return Val.MachineCPVal->getType(); 507 return Val.ConstVal->getType(); 508 } 509 510 511 unsigned MachineConstantPoolEntry::getRelocationInfo() const { 512 if (isMachineConstantPoolEntry()) 513 return Val.MachineCPVal->getRelocationInfo(); 514 return Val.ConstVal->getRelocationInfo(); 515 } 516 517 MachineConstantPool::~MachineConstantPool() { 518 for (unsigned i = 0, e = Constants.size(); i != e; ++i) 519 if (Constants[i].isMachineConstantPoolEntry()) 520 delete Constants[i].Val.MachineCPVal; 521 } 522 523 /// getConstantPoolIndex - Create a new entry in the constant pool or return 524 /// an existing one. User must specify the log2 of the minimum required 525 /// alignment for the object. 526 /// 527 unsigned MachineConstantPool::getConstantPoolIndex(Constant *C, 528 unsigned Alignment) { 529 assert(Alignment && "Alignment must be specified!"); 530 if (Alignment > PoolAlignment) PoolAlignment = Alignment; 531 532 // Check to see if we already have this constant. 533 // 534 // FIXME, this could be made much more efficient for large constant pools. 535 for (unsigned i = 0, e = Constants.size(); i != e; ++i) 536 if (Constants[i].Val.ConstVal == C && 537 (Constants[i].getAlignment() & (Alignment - 1)) == 0) 538 return i; 539 540 Constants.push_back(MachineConstantPoolEntry(C, Alignment)); 541 return Constants.size()-1; 542 } 543 544 unsigned MachineConstantPool::getConstantPoolIndex(MachineConstantPoolValue *V, 545 unsigned Alignment) { 546 assert(Alignment && "Alignment must be specified!"); 547 if (Alignment > PoolAlignment) PoolAlignment = Alignment; 548 549 // Check to see if we already have this constant. 550 // 551 // FIXME, this could be made much more efficient for large constant pools. 552 int Idx = V->getExistingMachineCPValue(this, Alignment); 553 if (Idx != -1) 554 return (unsigned)Idx; 555 556 Constants.push_back(MachineConstantPoolEntry(V, Alignment)); 557 return Constants.size()-1; 558 } 559 560 void MachineConstantPool::print(raw_ostream &OS) const { 561 for (unsigned i = 0, e = Constants.size(); i != e; ++i) { 562 OS << " <cp#" << i << "> is"; 563 if (Constants[i].isMachineConstantPoolEntry()) 564 Constants[i].Val.MachineCPVal->print(OS); 565 else 566 OS << *(Value*)Constants[i].Val.ConstVal; 567 OS << " , alignment=" << Constants[i].getAlignment(); 568 OS << "\n"; 569 } 570 } 571 572 void MachineConstantPool::dump() const { print(errs()); } 573