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/CodeGen/MachineFunction.h" 17 #include "llvm/ADT/STLExtras.h" 18 #include "llvm/ADT/SmallString.h" 19 #include "llvm/Analysis/ConstantFolding.h" 20 #include "llvm/CodeGen/MachineConstantPool.h" 21 #include "llvm/CodeGen/MachineFrameInfo.h" 22 #include "llvm/CodeGen/MachineFunctionPass.h" 23 #include "llvm/CodeGen/MachineInstr.h" 24 #include "llvm/CodeGen/MachineJumpTableInfo.h" 25 #include "llvm/CodeGen/MachineModuleInfo.h" 26 #include "llvm/CodeGen/MachineRegisterInfo.h" 27 #include "llvm/CodeGen/Passes.h" 28 #include "llvm/DataLayout.h" 29 #include "llvm/DebugInfo.h" 30 #include "llvm/Function.h" 31 #include "llvm/MC/MCAsmInfo.h" 32 #include "llvm/MC/MCContext.h" 33 #include "llvm/Support/Debug.h" 34 #include "llvm/Support/GraphWriter.h" 35 #include "llvm/Support/raw_ostream.h" 36 #include "llvm/Target/TargetFrameLowering.h" 37 #include "llvm/Target/TargetLowering.h" 38 #include "llvm/Target/TargetMachine.h" 39 using namespace llvm; 40 41 //===----------------------------------------------------------------------===// 42 // MachineFunction implementation 43 //===----------------------------------------------------------------------===// 44 45 // Out of line virtual method. 46 MachineFunctionInfo::~MachineFunctionInfo() {} 47 48 void ilist_traits<MachineBasicBlock>::deleteNode(MachineBasicBlock *MBB) { 49 MBB->getParent()->DeleteMachineBasicBlock(MBB); 50 } 51 52 MachineFunction::MachineFunction(const Function *F, const TargetMachine &TM, 53 unsigned FunctionNum, MachineModuleInfo &mmi, 54 GCModuleInfo* gmi) 55 : Fn(F), Target(TM), Ctx(mmi.getContext()), MMI(mmi), GMI(gmi) { 56 if (TM.getRegisterInfo()) 57 RegInfo = new (Allocator) MachineRegisterInfo(*TM.getRegisterInfo()); 58 else 59 RegInfo = 0; 60 MFInfo = 0; 61 FrameInfo = new (Allocator) MachineFrameInfo(*TM.getFrameLowering()); 62 if (Fn->getFnAttributes().hasAttribute(Attributes::StackAlignment)) 63 FrameInfo->ensureMaxAlignment(Fn->getAttributes(). 64 getFnAttributes().getStackAlignment()); 65 ConstantPool = new (Allocator) MachineConstantPool(TM.getDataLayout()); 66 Alignment = TM.getTargetLowering()->getMinFunctionAlignment(); 67 // FIXME: Shouldn't use pref alignment if explicit alignment is set on Fn. 68 if (!Fn->getFnAttributes().hasAttribute(Attributes::OptimizeForSize)) 69 Alignment = std::max(Alignment, 70 TM.getTargetLowering()->getPrefFunctionAlignment()); 71 FunctionNumber = FunctionNum; 72 JumpTableInfo = 0; 73 } 74 75 MachineFunction::~MachineFunction() { 76 BasicBlocks.clear(); 77 InstructionRecycler.clear(Allocator); 78 BasicBlockRecycler.clear(Allocator); 79 if (RegInfo) { 80 RegInfo->~MachineRegisterInfo(); 81 Allocator.Deallocate(RegInfo); 82 } 83 if (MFInfo) { 84 MFInfo->~MachineFunctionInfo(); 85 Allocator.Deallocate(MFInfo); 86 } 87 88 FrameInfo->~MachineFrameInfo(); 89 Allocator.Deallocate(FrameInfo); 90 91 ConstantPool->~MachineConstantPool(); 92 Allocator.Deallocate(ConstantPool); 93 94 if (JumpTableInfo) { 95 JumpTableInfo->~MachineJumpTableInfo(); 96 Allocator.Deallocate(JumpTableInfo); 97 } 98 } 99 100 /// getOrCreateJumpTableInfo - Get the JumpTableInfo for this function, if it 101 /// does already exist, allocate one. 102 MachineJumpTableInfo *MachineFunction:: 103 getOrCreateJumpTableInfo(unsigned EntryKind) { 104 if (JumpTableInfo) return JumpTableInfo; 105 106 JumpTableInfo = new (Allocator) 107 MachineJumpTableInfo((MachineJumpTableInfo::JTEntryKind)EntryKind); 108 return JumpTableInfo; 109 } 110 111 /// RenumberBlocks - This discards all of the MachineBasicBlock numbers and 112 /// recomputes them. This guarantees that the MBB numbers are sequential, 113 /// dense, and match the ordering of the blocks within the function. If a 114 /// specific MachineBasicBlock is specified, only that block and those after 115 /// it are renumbered. 116 void MachineFunction::RenumberBlocks(MachineBasicBlock *MBB) { 117 if (empty()) { MBBNumbering.clear(); return; } 118 MachineFunction::iterator MBBI, E = end(); 119 if (MBB == 0) 120 MBBI = begin(); 121 else 122 MBBI = MBB; 123 124 // Figure out the block number this should have. 125 unsigned BlockNo = 0; 126 if (MBBI != begin()) 127 BlockNo = prior(MBBI)->getNumber()+1; 128 129 for (; MBBI != E; ++MBBI, ++BlockNo) { 130 if (MBBI->getNumber() != (int)BlockNo) { 131 // Remove use of the old number. 132 if (MBBI->getNumber() != -1) { 133 assert(MBBNumbering[MBBI->getNumber()] == &*MBBI && 134 "MBB number mismatch!"); 135 MBBNumbering[MBBI->getNumber()] = 0; 136 } 137 138 // If BlockNo is already taken, set that block's number to -1. 139 if (MBBNumbering[BlockNo]) 140 MBBNumbering[BlockNo]->setNumber(-1); 141 142 MBBNumbering[BlockNo] = MBBI; 143 MBBI->setNumber(BlockNo); 144 } 145 } 146 147 // Okay, all the blocks are renumbered. If we have compactified the block 148 // numbering, shrink MBBNumbering now. 149 assert(BlockNo <= MBBNumbering.size() && "Mismatch!"); 150 MBBNumbering.resize(BlockNo); 151 } 152 153 /// CreateMachineInstr - Allocate a new MachineInstr. Use this instead 154 /// of `new MachineInstr'. 155 /// 156 MachineInstr * 157 MachineFunction::CreateMachineInstr(const MCInstrDesc &MCID, 158 DebugLoc DL, bool NoImp) { 159 return new (InstructionRecycler.Allocate<MachineInstr>(Allocator)) 160 MachineInstr(MCID, DL, NoImp); 161 } 162 163 /// CloneMachineInstr - Create a new MachineInstr which is a copy of the 164 /// 'Orig' instruction, identical in all ways except the instruction 165 /// has no parent, prev, or next. 166 /// 167 MachineInstr * 168 MachineFunction::CloneMachineInstr(const MachineInstr *Orig) { 169 return new (InstructionRecycler.Allocate<MachineInstr>(Allocator)) 170 MachineInstr(*this, *Orig); 171 } 172 173 /// DeleteMachineInstr - Delete the given MachineInstr. 174 /// 175 void 176 MachineFunction::DeleteMachineInstr(MachineInstr *MI) { 177 MI->~MachineInstr(); 178 InstructionRecycler.Deallocate(Allocator, MI); 179 } 180 181 /// CreateMachineBasicBlock - Allocate a new MachineBasicBlock. Use this 182 /// instead of `new MachineBasicBlock'. 183 /// 184 MachineBasicBlock * 185 MachineFunction::CreateMachineBasicBlock(const BasicBlock *bb) { 186 return new (BasicBlockRecycler.Allocate<MachineBasicBlock>(Allocator)) 187 MachineBasicBlock(*this, bb); 188 } 189 190 /// DeleteMachineBasicBlock - Delete the given MachineBasicBlock. 191 /// 192 void 193 MachineFunction::DeleteMachineBasicBlock(MachineBasicBlock *MBB) { 194 assert(MBB->getParent() == this && "MBB parent mismatch!"); 195 MBB->~MachineBasicBlock(); 196 BasicBlockRecycler.Deallocate(Allocator, MBB); 197 } 198 199 MachineMemOperand * 200 MachineFunction::getMachineMemOperand(MachinePointerInfo PtrInfo, unsigned f, 201 uint64_t s, unsigned base_alignment, 202 const MDNode *TBAAInfo, 203 const MDNode *Ranges) { 204 return new (Allocator) MachineMemOperand(PtrInfo, f, s, base_alignment, 205 TBAAInfo, Ranges); 206 } 207 208 MachineMemOperand * 209 MachineFunction::getMachineMemOperand(const MachineMemOperand *MMO, 210 int64_t Offset, uint64_t Size) { 211 return new (Allocator) 212 MachineMemOperand(MachinePointerInfo(MMO->getValue(), 213 MMO->getOffset()+Offset), 214 MMO->getFlags(), Size, 215 MMO->getBaseAlignment(), 0); 216 } 217 218 MachineInstr::mmo_iterator 219 MachineFunction::allocateMemRefsArray(unsigned long Num) { 220 return Allocator.Allocate<MachineMemOperand *>(Num); 221 } 222 223 std::pair<MachineInstr::mmo_iterator, MachineInstr::mmo_iterator> 224 MachineFunction::extractLoadMemRefs(MachineInstr::mmo_iterator Begin, 225 MachineInstr::mmo_iterator End) { 226 // Count the number of load mem refs. 227 unsigned Num = 0; 228 for (MachineInstr::mmo_iterator I = Begin; I != End; ++I) 229 if ((*I)->isLoad()) 230 ++Num; 231 232 // Allocate a new array and populate it with the load information. 233 MachineInstr::mmo_iterator Result = allocateMemRefsArray(Num); 234 unsigned Index = 0; 235 for (MachineInstr::mmo_iterator I = Begin; I != End; ++I) { 236 if ((*I)->isLoad()) { 237 if (!(*I)->isStore()) 238 // Reuse the MMO. 239 Result[Index] = *I; 240 else { 241 // Clone the MMO and unset the store flag. 242 MachineMemOperand *JustLoad = 243 getMachineMemOperand((*I)->getPointerInfo(), 244 (*I)->getFlags() & ~MachineMemOperand::MOStore, 245 (*I)->getSize(), (*I)->getBaseAlignment(), 246 (*I)->getTBAAInfo()); 247 Result[Index] = JustLoad; 248 } 249 ++Index; 250 } 251 } 252 return std::make_pair(Result, Result + Num); 253 } 254 255 std::pair<MachineInstr::mmo_iterator, MachineInstr::mmo_iterator> 256 MachineFunction::extractStoreMemRefs(MachineInstr::mmo_iterator Begin, 257 MachineInstr::mmo_iterator End) { 258 // Count the number of load mem refs. 259 unsigned Num = 0; 260 for (MachineInstr::mmo_iterator I = Begin; I != End; ++I) 261 if ((*I)->isStore()) 262 ++Num; 263 264 // Allocate a new array and populate it with the store information. 265 MachineInstr::mmo_iterator Result = allocateMemRefsArray(Num); 266 unsigned Index = 0; 267 for (MachineInstr::mmo_iterator I = Begin; I != End; ++I) { 268 if ((*I)->isStore()) { 269 if (!(*I)->isLoad()) 270 // Reuse the MMO. 271 Result[Index] = *I; 272 else { 273 // Clone the MMO and unset the load flag. 274 MachineMemOperand *JustStore = 275 getMachineMemOperand((*I)->getPointerInfo(), 276 (*I)->getFlags() & ~MachineMemOperand::MOLoad, 277 (*I)->getSize(), (*I)->getBaseAlignment(), 278 (*I)->getTBAAInfo()); 279 Result[Index] = JustStore; 280 } 281 ++Index; 282 } 283 } 284 return std::make_pair(Result, Result + Num); 285 } 286 287 #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP) 288 void MachineFunction::dump() const { 289 print(dbgs()); 290 } 291 #endif 292 293 StringRef MachineFunction::getName() const { 294 assert(getFunction() && "No function!"); 295 return getFunction()->getName(); 296 } 297 298 void MachineFunction::print(raw_ostream &OS, SlotIndexes *Indexes) const { 299 OS << "# Machine code for function " << getName() << ": "; 300 if (RegInfo) { 301 OS << (RegInfo->isSSA() ? "SSA" : "Post SSA"); 302 if (!RegInfo->tracksLiveness()) 303 OS << ", not tracking liveness"; 304 } 305 OS << '\n'; 306 307 // Print Frame Information 308 FrameInfo->print(*this, OS); 309 310 // Print JumpTable Information 311 if (JumpTableInfo) 312 JumpTableInfo->print(OS); 313 314 // Print Constant Pool 315 ConstantPool->print(OS); 316 317 const TargetRegisterInfo *TRI = getTarget().getRegisterInfo(); 318 319 if (RegInfo && !RegInfo->livein_empty()) { 320 OS << "Function Live Ins: "; 321 for (MachineRegisterInfo::livein_iterator 322 I = RegInfo->livein_begin(), E = RegInfo->livein_end(); I != E; ++I) { 323 OS << PrintReg(I->first, TRI); 324 if (I->second) 325 OS << " in " << PrintReg(I->second, TRI); 326 if (llvm::next(I) != E) 327 OS << ", "; 328 } 329 OS << '\n'; 330 } 331 if (RegInfo && !RegInfo->liveout_empty()) { 332 OS << "Function Live Outs:"; 333 for (MachineRegisterInfo::liveout_iterator 334 I = RegInfo->liveout_begin(), E = RegInfo->liveout_end(); I != E; ++I) 335 OS << ' ' << PrintReg(*I, TRI); 336 OS << '\n'; 337 } 338 339 for (const_iterator BB = begin(), E = end(); BB != E; ++BB) { 340 OS << '\n'; 341 BB->print(OS, Indexes); 342 } 343 344 OS << "\n# End machine code for function " << getName() << ".\n\n"; 345 } 346 347 namespace llvm { 348 template<> 349 struct DOTGraphTraits<const MachineFunction*> : public DefaultDOTGraphTraits { 350 351 DOTGraphTraits (bool isSimple=false) : DefaultDOTGraphTraits(isSimple) {} 352 353 static std::string getGraphName(const MachineFunction *F) { 354 return "CFG for '" + F->getName().str() + "' function"; 355 } 356 357 std::string getNodeLabel(const MachineBasicBlock *Node, 358 const MachineFunction *Graph) { 359 std::string OutStr; 360 { 361 raw_string_ostream OSS(OutStr); 362 363 if (isSimple()) { 364 OSS << "BB#" << Node->getNumber(); 365 if (const BasicBlock *BB = Node->getBasicBlock()) 366 OSS << ": " << BB->getName(); 367 } else 368 Node->print(OSS); 369 } 370 371 if (OutStr[0] == '\n') OutStr.erase(OutStr.begin()); 372 373 // Process string output to make it nicer... 374 for (unsigned i = 0; i != OutStr.length(); ++i) 375 if (OutStr[i] == '\n') { // Left justify 376 OutStr[i] = '\\'; 377 OutStr.insert(OutStr.begin()+i+1, 'l'); 378 } 379 return OutStr; 380 } 381 }; 382 } 383 384 void MachineFunction::viewCFG() const 385 { 386 #ifndef NDEBUG 387 ViewGraph(this, "mf" + getName()); 388 #else 389 errs() << "MachineFunction::viewCFG is only available in debug builds on " 390 << "systems with Graphviz or gv!\n"; 391 #endif // NDEBUG 392 } 393 394 void MachineFunction::viewCFGOnly() const 395 { 396 #ifndef NDEBUG 397 ViewGraph(this, "mf" + getName(), true); 398 #else 399 errs() << "MachineFunction::viewCFGOnly is only available in debug builds on " 400 << "systems with Graphviz or gv!\n"; 401 #endif // NDEBUG 402 } 403 404 /// addLiveIn - Add the specified physical register as a live-in value and 405 /// create a corresponding virtual register for it. 406 unsigned MachineFunction::addLiveIn(unsigned PReg, 407 const TargetRegisterClass *RC) { 408 MachineRegisterInfo &MRI = getRegInfo(); 409 unsigned VReg = MRI.getLiveInVirtReg(PReg); 410 if (VReg) { 411 assert(MRI.getRegClass(VReg) == RC && "Register class mismatch!"); 412 return VReg; 413 } 414 VReg = MRI.createVirtualRegister(RC); 415 MRI.addLiveIn(PReg, VReg); 416 return VReg; 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 *MachineFunction::getJTISymbol(unsigned JTI, MCContext &Ctx, 423 bool isLinkerPrivate) const { 424 assert(JumpTableInfo && "No jump tables"); 425 assert(JTI < JumpTableInfo->getJumpTables().size() && "Invalid JTI!"); 426 const MCAsmInfo &MAI = *getTarget().getMCAsmInfo(); 427 428 const char *Prefix = isLinkerPrivate ? MAI.getLinkerPrivateGlobalPrefix() : 429 MAI.getPrivateGlobalPrefix(); 430 SmallString<60> Name; 431 raw_svector_ostream(Name) 432 << Prefix << "JTI" << getFunctionNumber() << '_' << JTI; 433 return Ctx.GetOrCreateSymbol(Name.str()); 434 } 435 436 /// getPICBaseSymbol - Return a function-local symbol to represent the PIC 437 /// base. 438 MCSymbol *MachineFunction::getPICBaseSymbol() const { 439 const MCAsmInfo &MAI = *Target.getMCAsmInfo(); 440 return Ctx.GetOrCreateSymbol(Twine(MAI.getPrivateGlobalPrefix())+ 441 Twine(getFunctionNumber())+"$pb"); 442 } 443 444 //===----------------------------------------------------------------------===// 445 // MachineFrameInfo implementation 446 //===----------------------------------------------------------------------===// 447 448 /// ensureMaxAlignment - Make sure the function is at least Align bytes 449 /// aligned. 450 void MachineFrameInfo::ensureMaxAlignment(unsigned Align) { 451 if (MaxAlignment < Align) MaxAlignment = Align; 452 } 453 454 /// CreateStackObject - Create a new statically sized stack object, returning 455 /// a nonnegative identifier to represent it. 456 /// 457 int MachineFrameInfo::CreateStackObject(uint64_t Size, unsigned Alignment, 458 bool isSS, bool MayNeedSP, const AllocaInst *Alloca) { 459 assert(Size != 0 && "Cannot allocate zero size stack objects!"); 460 Objects.push_back(StackObject(Size, Alignment, 0, false, isSS, MayNeedSP, 461 Alloca)); 462 int Index = (int)Objects.size() - NumFixedObjects - 1; 463 assert(Index >= 0 && "Bad frame index!"); 464 ensureMaxAlignment(Alignment); 465 return Index; 466 } 467 468 /// CreateSpillStackObject - Create a new statically sized stack object that 469 /// represents a spill slot, returning a nonnegative identifier to represent 470 /// it. 471 /// 472 int MachineFrameInfo::CreateSpillStackObject(uint64_t Size, 473 unsigned Alignment) { 474 CreateStackObject(Size, Alignment, true, false); 475 int Index = (int)Objects.size() - NumFixedObjects - 1; 476 ensureMaxAlignment(Alignment); 477 return Index; 478 } 479 480 /// CreateVariableSizedObject - Notify the MachineFrameInfo object that a 481 /// variable sized object has been created. This must be created whenever a 482 /// variable sized object is created, whether or not the index returned is 483 /// actually used. 484 /// 485 int MachineFrameInfo::CreateVariableSizedObject(unsigned Alignment) { 486 HasVarSizedObjects = true; 487 Objects.push_back(StackObject(0, Alignment, 0, false, false, true, 0)); 488 ensureMaxAlignment(Alignment); 489 return (int)Objects.size()-NumFixedObjects-1; 490 } 491 492 /// CreateFixedObject - Create a new object at a fixed location on the stack. 493 /// All fixed objects should be created before other objects are created for 494 /// efficiency. By default, fixed objects are immutable. This returns an 495 /// index with a negative value. 496 /// 497 int MachineFrameInfo::CreateFixedObject(uint64_t Size, int64_t SPOffset, 498 bool Immutable) { 499 assert(Size != 0 && "Cannot allocate zero size fixed stack objects!"); 500 // The alignment of the frame index can be determined from its offset from 501 // the incoming frame position. If the frame object is at offset 32 and 502 // the stack is guaranteed to be 16-byte aligned, then we know that the 503 // object is 16-byte aligned. 504 unsigned StackAlign = TFI.getStackAlignment(); 505 unsigned Align = MinAlign(SPOffset, StackAlign); 506 Objects.insert(Objects.begin(), StackObject(Size, Align, SPOffset, Immutable, 507 /*isSS*/ false, 508 /*NeedSP*/ false, 509 /*Alloca*/ 0)); 510 return -++NumFixedObjects; 511 } 512 513 514 BitVector 515 MachineFrameInfo::getPristineRegs(const MachineBasicBlock *MBB) const { 516 assert(MBB && "MBB must be valid"); 517 const MachineFunction *MF = MBB->getParent(); 518 assert(MF && "MBB must be part of a MachineFunction"); 519 const TargetMachine &TM = MF->getTarget(); 520 const TargetRegisterInfo *TRI = TM.getRegisterInfo(); 521 BitVector BV(TRI->getNumRegs()); 522 523 // Before CSI is calculated, no registers are considered pristine. They can be 524 // freely used and PEI will make sure they are saved. 525 if (!isCalleeSavedInfoValid()) 526 return BV; 527 528 for (const uint16_t *CSR = TRI->getCalleeSavedRegs(MF); CSR && *CSR; ++CSR) 529 BV.set(*CSR); 530 531 // The entry MBB always has all CSRs pristine. 532 if (MBB == &MF->front()) 533 return BV; 534 535 // On other MBBs the saved CSRs are not pristine. 536 const std::vector<CalleeSavedInfo> &CSI = getCalleeSavedInfo(); 537 for (std::vector<CalleeSavedInfo>::const_iterator I = CSI.begin(), 538 E = CSI.end(); I != E; ++I) 539 BV.reset(I->getReg()); 540 541 return BV; 542 } 543 544 545 void MachineFrameInfo::print(const MachineFunction &MF, raw_ostream &OS) const{ 546 if (Objects.empty()) return; 547 548 const TargetFrameLowering *FI = MF.getTarget().getFrameLowering(); 549 int ValOffset = (FI ? FI->getOffsetOfLocalArea() : 0); 550 551 OS << "Frame Objects:\n"; 552 553 for (unsigned i = 0, e = Objects.size(); i != e; ++i) { 554 const StackObject &SO = Objects[i]; 555 OS << " fi#" << (int)(i-NumFixedObjects) << ": "; 556 if (SO.Size == ~0ULL) { 557 OS << "dead\n"; 558 continue; 559 } 560 if (SO.Size == 0) 561 OS << "variable sized"; 562 else 563 OS << "size=" << SO.Size; 564 OS << ", align=" << SO.Alignment; 565 566 if (i < NumFixedObjects) 567 OS << ", fixed"; 568 if (i < NumFixedObjects || SO.SPOffset != -1) { 569 int64_t Off = SO.SPOffset - ValOffset; 570 OS << ", at location [SP"; 571 if (Off > 0) 572 OS << "+" << Off; 573 else if (Off < 0) 574 OS << Off; 575 OS << "]"; 576 } 577 OS << "\n"; 578 } 579 } 580 581 #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP) 582 void MachineFrameInfo::dump(const MachineFunction &MF) const { 583 print(MF, dbgs()); 584 } 585 #endif 586 587 //===----------------------------------------------------------------------===// 588 // MachineJumpTableInfo implementation 589 //===----------------------------------------------------------------------===// 590 591 /// getEntrySize - Return the size of each entry in the jump table. 592 unsigned MachineJumpTableInfo::getEntrySize(const DataLayout &TD) const { 593 // The size of a jump table entry is 4 bytes unless the entry is just the 594 // address of a block, in which case it is the pointer size. 595 switch (getEntryKind()) { 596 case MachineJumpTableInfo::EK_BlockAddress: 597 return TD.getPointerSize(); 598 case MachineJumpTableInfo::EK_GPRel64BlockAddress: 599 return 8; 600 case MachineJumpTableInfo::EK_GPRel32BlockAddress: 601 case MachineJumpTableInfo::EK_LabelDifference32: 602 case MachineJumpTableInfo::EK_Custom32: 603 return 4; 604 case MachineJumpTableInfo::EK_Inline: 605 return 0; 606 } 607 llvm_unreachable("Unknown jump table encoding!"); 608 } 609 610 /// getEntryAlignment - Return the alignment of each entry in the jump table. 611 unsigned MachineJumpTableInfo::getEntryAlignment(const DataLayout &TD) const { 612 // The alignment of a jump table entry is the alignment of int32 unless the 613 // entry is just the address of a block, in which case it is the pointer 614 // alignment. 615 switch (getEntryKind()) { 616 case MachineJumpTableInfo::EK_BlockAddress: 617 return TD.getPointerABIAlignment(); 618 case MachineJumpTableInfo::EK_GPRel64BlockAddress: 619 return TD.getABIIntegerTypeAlignment(64); 620 case MachineJumpTableInfo::EK_GPRel32BlockAddress: 621 case MachineJumpTableInfo::EK_LabelDifference32: 622 case MachineJumpTableInfo::EK_Custom32: 623 return TD.getABIIntegerTypeAlignment(32); 624 case MachineJumpTableInfo::EK_Inline: 625 return 1; 626 } 627 llvm_unreachable("Unknown jump table encoding!"); 628 } 629 630 /// createJumpTableIndex - Create a new jump table entry in the jump table info. 631 /// 632 unsigned MachineJumpTableInfo::createJumpTableIndex( 633 const std::vector<MachineBasicBlock*> &DestBBs) { 634 assert(!DestBBs.empty() && "Cannot create an empty jump table!"); 635 JumpTables.push_back(MachineJumpTableEntry(DestBBs)); 636 return JumpTables.size()-1; 637 } 638 639 /// ReplaceMBBInJumpTables - If Old is the target of any jump tables, update 640 /// the jump tables to branch to New instead. 641 bool MachineJumpTableInfo::ReplaceMBBInJumpTables(MachineBasicBlock *Old, 642 MachineBasicBlock *New) { 643 assert(Old != New && "Not making a change?"); 644 bool MadeChange = false; 645 for (size_t i = 0, e = JumpTables.size(); i != e; ++i) 646 ReplaceMBBInJumpTable(i, Old, New); 647 return MadeChange; 648 } 649 650 /// ReplaceMBBInJumpTable - If Old is a target of the jump tables, update 651 /// the jump table to branch to New instead. 652 bool MachineJumpTableInfo::ReplaceMBBInJumpTable(unsigned Idx, 653 MachineBasicBlock *Old, 654 MachineBasicBlock *New) { 655 assert(Old != New && "Not making a change?"); 656 bool MadeChange = false; 657 MachineJumpTableEntry &JTE = JumpTables[Idx]; 658 for (size_t j = 0, e = JTE.MBBs.size(); j != e; ++j) 659 if (JTE.MBBs[j] == Old) { 660 JTE.MBBs[j] = New; 661 MadeChange = true; 662 } 663 return MadeChange; 664 } 665 666 void MachineJumpTableInfo::print(raw_ostream &OS) const { 667 if (JumpTables.empty()) return; 668 669 OS << "Jump Tables:\n"; 670 671 for (unsigned i = 0, e = JumpTables.size(); i != e; ++i) { 672 OS << " jt#" << i << ": "; 673 for (unsigned j = 0, f = JumpTables[i].MBBs.size(); j != f; ++j) 674 OS << " BB#" << JumpTables[i].MBBs[j]->getNumber(); 675 } 676 677 OS << '\n'; 678 } 679 680 #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP) 681 void MachineJumpTableInfo::dump() const { print(dbgs()); } 682 #endif 683 684 685 //===----------------------------------------------------------------------===// 686 // MachineConstantPool implementation 687 //===----------------------------------------------------------------------===// 688 689 void MachineConstantPoolValue::anchor() { } 690 691 Type *MachineConstantPoolEntry::getType() const { 692 if (isMachineConstantPoolEntry()) 693 return Val.MachineCPVal->getType(); 694 return Val.ConstVal->getType(); 695 } 696 697 698 unsigned MachineConstantPoolEntry::getRelocationInfo() const { 699 if (isMachineConstantPoolEntry()) 700 return Val.MachineCPVal->getRelocationInfo(); 701 return Val.ConstVal->getRelocationInfo(); 702 } 703 704 MachineConstantPool::~MachineConstantPool() { 705 for (unsigned i = 0, e = Constants.size(); i != e; ++i) 706 if (Constants[i].isMachineConstantPoolEntry()) 707 delete Constants[i].Val.MachineCPVal; 708 for (DenseSet<MachineConstantPoolValue*>::iterator I = 709 MachineCPVsSharingEntries.begin(), E = MachineCPVsSharingEntries.end(); 710 I != E; ++I) 711 delete *I; 712 } 713 714 /// CanShareConstantPoolEntry - Test whether the given two constants 715 /// can be allocated the same constant pool entry. 716 static bool CanShareConstantPoolEntry(const Constant *A, const Constant *B, 717 const DataLayout *TD) { 718 // Handle the trivial case quickly. 719 if (A == B) return true; 720 721 // If they have the same type but weren't the same constant, quickly 722 // reject them. 723 if (A->getType() == B->getType()) return false; 724 725 // We can't handle structs or arrays. 726 if (isa<StructType>(A->getType()) || isa<ArrayType>(A->getType()) || 727 isa<StructType>(B->getType()) || isa<ArrayType>(B->getType())) 728 return false; 729 730 // For now, only support constants with the same size. 731 uint64_t StoreSize = TD->getTypeStoreSize(A->getType()); 732 if (StoreSize != TD->getTypeStoreSize(B->getType()) || 733 StoreSize > 128) 734 return false; 735 736 Type *IntTy = IntegerType::get(A->getContext(), StoreSize*8); 737 738 // Try constant folding a bitcast of both instructions to an integer. If we 739 // get two identical ConstantInt's, then we are good to share them. We use 740 // the constant folding APIs to do this so that we get the benefit of 741 // DataLayout. 742 if (isa<PointerType>(A->getType())) 743 A = ConstantFoldInstOperands(Instruction::PtrToInt, IntTy, 744 const_cast<Constant*>(A), TD); 745 else if (A->getType() != IntTy) 746 A = ConstantFoldInstOperands(Instruction::BitCast, IntTy, 747 const_cast<Constant*>(A), TD); 748 if (isa<PointerType>(B->getType())) 749 B = ConstantFoldInstOperands(Instruction::PtrToInt, IntTy, 750 const_cast<Constant*>(B), TD); 751 else if (B->getType() != IntTy) 752 B = ConstantFoldInstOperands(Instruction::BitCast, IntTy, 753 const_cast<Constant*>(B), TD); 754 755 return A == B; 756 } 757 758 /// getConstantPoolIndex - Create a new entry in the constant pool or return 759 /// an existing one. User must specify the log2 of the minimum required 760 /// alignment for the object. 761 /// 762 unsigned MachineConstantPool::getConstantPoolIndex(const Constant *C, 763 unsigned Alignment) { 764 assert(Alignment && "Alignment must be specified!"); 765 if (Alignment > PoolAlignment) PoolAlignment = Alignment; 766 767 // Check to see if we already have this constant. 768 // 769 // FIXME, this could be made much more efficient for large constant pools. 770 for (unsigned i = 0, e = Constants.size(); i != e; ++i) 771 if (!Constants[i].isMachineConstantPoolEntry() && 772 CanShareConstantPoolEntry(Constants[i].Val.ConstVal, C, TD)) { 773 if ((unsigned)Constants[i].getAlignment() < Alignment) 774 Constants[i].Alignment = Alignment; 775 return i; 776 } 777 778 Constants.push_back(MachineConstantPoolEntry(C, Alignment)); 779 return Constants.size()-1; 780 } 781 782 unsigned MachineConstantPool::getConstantPoolIndex(MachineConstantPoolValue *V, 783 unsigned Alignment) { 784 assert(Alignment && "Alignment must be specified!"); 785 if (Alignment > PoolAlignment) PoolAlignment = Alignment; 786 787 // Check to see if we already have this constant. 788 // 789 // FIXME, this could be made much more efficient for large constant pools. 790 int Idx = V->getExistingMachineCPValue(this, Alignment); 791 if (Idx != -1) { 792 MachineCPVsSharingEntries.insert(V); 793 return (unsigned)Idx; 794 } 795 796 Constants.push_back(MachineConstantPoolEntry(V, Alignment)); 797 return Constants.size()-1; 798 } 799 800 void MachineConstantPool::print(raw_ostream &OS) const { 801 if (Constants.empty()) return; 802 803 OS << "Constant Pool:\n"; 804 for (unsigned i = 0, e = Constants.size(); i != e; ++i) { 805 OS << " cp#" << i << ": "; 806 if (Constants[i].isMachineConstantPoolEntry()) 807 Constants[i].Val.MachineCPVal->print(OS); 808 else 809 OS << *(const Value*)Constants[i].Val.ConstVal; 810 OS << ", align=" << Constants[i].getAlignment(); 811 OS << "\n"; 812 } 813 } 814 815 #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP) 816 void MachineConstantPool::dump() const { print(dbgs()); } 817 #endif 818