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/MachineFunctionInitializer.h" 23 #include "llvm/CodeGen/MachineFunctionPass.h" 24 #include "llvm/CodeGen/MachineInstr.h" 25 #include "llvm/CodeGen/MachineJumpTableInfo.h" 26 #include "llvm/CodeGen/MachineModuleInfo.h" 27 #include "llvm/CodeGen/MachineRegisterInfo.h" 28 #include "llvm/CodeGen/Passes.h" 29 #include "llvm/IR/DataLayout.h" 30 #include "llvm/IR/DebugInfo.h" 31 #include "llvm/IR/Function.h" 32 #include "llvm/IR/Module.h" 33 #include "llvm/IR/ModuleSlotTracker.h" 34 #include "llvm/MC/MCAsmInfo.h" 35 #include "llvm/MC/MCContext.h" 36 #include "llvm/Support/Debug.h" 37 #include "llvm/Support/GraphWriter.h" 38 #include "llvm/Support/raw_ostream.h" 39 #include "llvm/Target/TargetFrameLowering.h" 40 #include "llvm/Target/TargetLowering.h" 41 #include "llvm/Target/TargetMachine.h" 42 #include "llvm/Target/TargetSubtargetInfo.h" 43 using namespace llvm; 44 45 #define DEBUG_TYPE "codegen" 46 47 void MachineFunctionInitializer::anchor() {} 48 49 //===----------------------------------------------------------------------===// 50 // MachineFunction implementation 51 //===----------------------------------------------------------------------===// 52 53 // Out-of-line virtual method. 54 MachineFunctionInfo::~MachineFunctionInfo() {} 55 56 void ilist_traits<MachineBasicBlock>::deleteNode(MachineBasicBlock *MBB) { 57 MBB->getParent()->DeleteMachineBasicBlock(MBB); 58 } 59 60 MachineFunction::MachineFunction(const Function *F, const TargetMachine &TM, 61 unsigned FunctionNum, MachineModuleInfo &mmi) 62 : Fn(F), Target(TM), STI(TM.getSubtargetImpl(*F)), Ctx(mmi.getContext()), 63 MMI(mmi) { 64 if (STI->getRegisterInfo()) 65 RegInfo = new (Allocator) MachineRegisterInfo(this); 66 else 67 RegInfo = nullptr; 68 69 MFInfo = nullptr; 70 FrameInfo = new (Allocator) 71 MachineFrameInfo(STI->getFrameLowering()->getStackAlignment(), 72 STI->getFrameLowering()->isStackRealignable(), 73 !F->hasFnAttribute("no-realign-stack")); 74 75 if (Fn->hasFnAttribute(Attribute::StackAlignment)) 76 FrameInfo->ensureMaxAlignment(Fn->getFnStackAlignment()); 77 78 ConstantPool = new (Allocator) MachineConstantPool(getDataLayout()); 79 Alignment = STI->getTargetLowering()->getMinFunctionAlignment(); 80 81 // FIXME: Shouldn't use pref alignment if explicit alignment is set on Fn. 82 if (!Fn->hasFnAttribute(Attribute::OptimizeForSize)) 83 Alignment = std::max(Alignment, 84 STI->getTargetLowering()->getPrefFunctionAlignment()); 85 86 FunctionNumber = FunctionNum; 87 JumpTableInfo = nullptr; 88 } 89 90 MachineFunction::~MachineFunction() { 91 // Don't call destructors on MachineInstr and MachineOperand. All of their 92 // memory comes from the BumpPtrAllocator which is about to be purged. 93 // 94 // Do call MachineBasicBlock destructors, it contains std::vectors. 95 for (iterator I = begin(), E = end(); I != E; I = BasicBlocks.erase(I)) 96 I->Insts.clearAndLeakNodesUnsafely(); 97 98 InstructionRecycler.clear(Allocator); 99 OperandRecycler.clear(Allocator); 100 BasicBlockRecycler.clear(Allocator); 101 if (RegInfo) { 102 RegInfo->~MachineRegisterInfo(); 103 Allocator.Deallocate(RegInfo); 104 } 105 if (MFInfo) { 106 MFInfo->~MachineFunctionInfo(); 107 Allocator.Deallocate(MFInfo); 108 } 109 110 FrameInfo->~MachineFrameInfo(); 111 Allocator.Deallocate(FrameInfo); 112 113 ConstantPool->~MachineConstantPool(); 114 Allocator.Deallocate(ConstantPool); 115 116 if (JumpTableInfo) { 117 JumpTableInfo->~MachineJumpTableInfo(); 118 Allocator.Deallocate(JumpTableInfo); 119 } 120 } 121 122 const DataLayout &MachineFunction::getDataLayout() const { 123 return Fn->getParent()->getDataLayout(); 124 } 125 126 /// Get the JumpTableInfo for this function. 127 /// If it does not already exist, allocate one. 128 MachineJumpTableInfo *MachineFunction:: 129 getOrCreateJumpTableInfo(unsigned EntryKind) { 130 if (JumpTableInfo) return JumpTableInfo; 131 132 JumpTableInfo = new (Allocator) 133 MachineJumpTableInfo((MachineJumpTableInfo::JTEntryKind)EntryKind); 134 return JumpTableInfo; 135 } 136 137 /// Should we be emitting segmented stack stuff for the function 138 bool MachineFunction::shouldSplitStack() { 139 return getFunction()->hasFnAttribute("split-stack"); 140 } 141 142 /// This discards all of the MachineBasicBlock numbers and recomputes them. 143 /// This guarantees that the MBB numbers are sequential, dense, and match the 144 /// ordering of the blocks within the function. If a specific MachineBasicBlock 145 /// is specified, only that block and those after it are renumbered. 146 void MachineFunction::RenumberBlocks(MachineBasicBlock *MBB) { 147 if (empty()) { MBBNumbering.clear(); return; } 148 MachineFunction::iterator MBBI, E = end(); 149 if (MBB == nullptr) 150 MBBI = begin(); 151 else 152 MBBI = MBB; 153 154 // Figure out the block number this should have. 155 unsigned BlockNo = 0; 156 if (MBBI != begin()) 157 BlockNo = std::prev(MBBI)->getNumber() + 1; 158 159 for (; MBBI != E; ++MBBI, ++BlockNo) { 160 if (MBBI->getNumber() != (int)BlockNo) { 161 // Remove use of the old number. 162 if (MBBI->getNumber() != -1) { 163 assert(MBBNumbering[MBBI->getNumber()] == &*MBBI && 164 "MBB number mismatch!"); 165 MBBNumbering[MBBI->getNumber()] = nullptr; 166 } 167 168 // If BlockNo is already taken, set that block's number to -1. 169 if (MBBNumbering[BlockNo]) 170 MBBNumbering[BlockNo]->setNumber(-1); 171 172 MBBNumbering[BlockNo] = MBBI; 173 MBBI->setNumber(BlockNo); 174 } 175 } 176 177 // Okay, all the blocks are renumbered. If we have compactified the block 178 // numbering, shrink MBBNumbering now. 179 assert(BlockNo <= MBBNumbering.size() && "Mismatch!"); 180 MBBNumbering.resize(BlockNo); 181 } 182 183 /// Allocate a new MachineInstr. Use this instead of `new MachineInstr'. 184 MachineInstr * 185 MachineFunction::CreateMachineInstr(const MCInstrDesc &MCID, 186 DebugLoc DL, bool NoImp) { 187 return new (InstructionRecycler.Allocate<MachineInstr>(Allocator)) 188 MachineInstr(*this, MCID, DL, NoImp); 189 } 190 191 /// Create a new MachineInstr which is a copy of the 'Orig' instruction, 192 /// identical in all ways except the instruction has no parent, prev, or next. 193 MachineInstr * 194 MachineFunction::CloneMachineInstr(const MachineInstr *Orig) { 195 return new (InstructionRecycler.Allocate<MachineInstr>(Allocator)) 196 MachineInstr(*this, *Orig); 197 } 198 199 /// Delete the given MachineInstr. 200 /// 201 /// This function also serves as the MachineInstr destructor - the real 202 /// ~MachineInstr() destructor must be empty. 203 void 204 MachineFunction::DeleteMachineInstr(MachineInstr *MI) { 205 // Strip it for parts. The operand array and the MI object itself are 206 // independently recyclable. 207 if (MI->Operands) 208 deallocateOperandArray(MI->CapOperands, MI->Operands); 209 // Don't call ~MachineInstr() which must be trivial anyway because 210 // ~MachineFunction drops whole lists of MachineInstrs wihout calling their 211 // destructors. 212 InstructionRecycler.Deallocate(Allocator, MI); 213 } 214 215 /// Allocate a new MachineBasicBlock. Use this instead of 216 /// `new MachineBasicBlock'. 217 MachineBasicBlock * 218 MachineFunction::CreateMachineBasicBlock(const BasicBlock *bb) { 219 return new (BasicBlockRecycler.Allocate<MachineBasicBlock>(Allocator)) 220 MachineBasicBlock(*this, bb); 221 } 222 223 /// Delete the given MachineBasicBlock. 224 void 225 MachineFunction::DeleteMachineBasicBlock(MachineBasicBlock *MBB) { 226 assert(MBB->getParent() == this && "MBB parent mismatch!"); 227 MBB->~MachineBasicBlock(); 228 BasicBlockRecycler.Deallocate(Allocator, MBB); 229 } 230 231 MachineMemOperand * 232 MachineFunction::getMachineMemOperand(MachinePointerInfo PtrInfo, unsigned f, 233 uint64_t s, unsigned base_alignment, 234 const AAMDNodes &AAInfo, 235 const MDNode *Ranges) { 236 return new (Allocator) MachineMemOperand(PtrInfo, f, s, base_alignment, 237 AAInfo, Ranges); 238 } 239 240 MachineMemOperand * 241 MachineFunction::getMachineMemOperand(const MachineMemOperand *MMO, 242 int64_t Offset, uint64_t Size) { 243 if (MMO->getValue()) 244 return new (Allocator) 245 MachineMemOperand(MachinePointerInfo(MMO->getValue(), 246 MMO->getOffset()+Offset), 247 MMO->getFlags(), Size, 248 MMO->getBaseAlignment()); 249 return new (Allocator) 250 MachineMemOperand(MachinePointerInfo(MMO->getPseudoValue(), 251 MMO->getOffset()+Offset), 252 MMO->getFlags(), Size, 253 MMO->getBaseAlignment()); 254 } 255 256 MachineInstr::mmo_iterator 257 MachineFunction::allocateMemRefsArray(unsigned long Num) { 258 return Allocator.Allocate<MachineMemOperand *>(Num); 259 } 260 261 std::pair<MachineInstr::mmo_iterator, MachineInstr::mmo_iterator> 262 MachineFunction::extractLoadMemRefs(MachineInstr::mmo_iterator Begin, 263 MachineInstr::mmo_iterator End) { 264 // Count the number of load mem refs. 265 unsigned Num = 0; 266 for (MachineInstr::mmo_iterator I = Begin; I != End; ++I) 267 if ((*I)->isLoad()) 268 ++Num; 269 270 // Allocate a new array and populate it with the load information. 271 MachineInstr::mmo_iterator Result = allocateMemRefsArray(Num); 272 unsigned Index = 0; 273 for (MachineInstr::mmo_iterator I = Begin; I != End; ++I) { 274 if ((*I)->isLoad()) { 275 if (!(*I)->isStore()) 276 // Reuse the MMO. 277 Result[Index] = *I; 278 else { 279 // Clone the MMO and unset the store flag. 280 MachineMemOperand *JustLoad = 281 getMachineMemOperand((*I)->getPointerInfo(), 282 (*I)->getFlags() & ~MachineMemOperand::MOStore, 283 (*I)->getSize(), (*I)->getBaseAlignment(), 284 (*I)->getAAInfo()); 285 Result[Index] = JustLoad; 286 } 287 ++Index; 288 } 289 } 290 return std::make_pair(Result, Result + Num); 291 } 292 293 std::pair<MachineInstr::mmo_iterator, MachineInstr::mmo_iterator> 294 MachineFunction::extractStoreMemRefs(MachineInstr::mmo_iterator Begin, 295 MachineInstr::mmo_iterator End) { 296 // Count the number of load mem refs. 297 unsigned Num = 0; 298 for (MachineInstr::mmo_iterator I = Begin; I != End; ++I) 299 if ((*I)->isStore()) 300 ++Num; 301 302 // Allocate a new array and populate it with the store information. 303 MachineInstr::mmo_iterator Result = allocateMemRefsArray(Num); 304 unsigned Index = 0; 305 for (MachineInstr::mmo_iterator I = Begin; I != End; ++I) { 306 if ((*I)->isStore()) { 307 if (!(*I)->isLoad()) 308 // Reuse the MMO. 309 Result[Index] = *I; 310 else { 311 // Clone the MMO and unset the load flag. 312 MachineMemOperand *JustStore = 313 getMachineMemOperand((*I)->getPointerInfo(), 314 (*I)->getFlags() & ~MachineMemOperand::MOLoad, 315 (*I)->getSize(), (*I)->getBaseAlignment(), 316 (*I)->getAAInfo()); 317 Result[Index] = JustStore; 318 } 319 ++Index; 320 } 321 } 322 return std::make_pair(Result, Result + Num); 323 } 324 325 #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP) 326 void MachineFunction::dump() const { 327 print(dbgs()); 328 } 329 #endif 330 331 StringRef MachineFunction::getName() const { 332 assert(getFunction() && "No function!"); 333 return getFunction()->getName(); 334 } 335 336 void MachineFunction::print(raw_ostream &OS, SlotIndexes *Indexes) const { 337 OS << "# Machine code for function " << getName() << ": "; 338 if (RegInfo) { 339 OS << (RegInfo->isSSA() ? "SSA" : "Post SSA"); 340 if (!RegInfo->tracksLiveness()) 341 OS << ", not tracking liveness"; 342 } 343 OS << '\n'; 344 345 // Print Frame Information 346 FrameInfo->print(*this, OS); 347 348 // Print JumpTable Information 349 if (JumpTableInfo) 350 JumpTableInfo->print(OS); 351 352 // Print Constant Pool 353 ConstantPool->print(OS); 354 355 const TargetRegisterInfo *TRI = getSubtarget().getRegisterInfo(); 356 357 if (RegInfo && !RegInfo->livein_empty()) { 358 OS << "Function Live Ins: "; 359 for (MachineRegisterInfo::livein_iterator 360 I = RegInfo->livein_begin(), E = RegInfo->livein_end(); I != E; ++I) { 361 OS << PrintReg(I->first, TRI); 362 if (I->second) 363 OS << " in " << PrintReg(I->second, TRI); 364 if (std::next(I) != E) 365 OS << ", "; 366 } 367 OS << '\n'; 368 } 369 370 ModuleSlotTracker MST(getFunction()->getParent()); 371 MST.incorporateFunction(*getFunction()); 372 for (const auto &BB : *this) { 373 OS << '\n'; 374 BB.print(OS, MST, Indexes); 375 } 376 377 OS << "\n# End machine code for function " << getName() << ".\n\n"; 378 } 379 380 namespace llvm { 381 template<> 382 struct DOTGraphTraits<const MachineFunction*> : public DefaultDOTGraphTraits { 383 384 DOTGraphTraits (bool isSimple=false) : DefaultDOTGraphTraits(isSimple) {} 385 386 static std::string getGraphName(const MachineFunction *F) { 387 return ("CFG for '" + F->getName() + "' function").str(); 388 } 389 390 std::string getNodeLabel(const MachineBasicBlock *Node, 391 const MachineFunction *Graph) { 392 std::string OutStr; 393 { 394 raw_string_ostream OSS(OutStr); 395 396 if (isSimple()) { 397 OSS << "BB#" << Node->getNumber(); 398 if (const BasicBlock *BB = Node->getBasicBlock()) 399 OSS << ": " << BB->getName(); 400 } else 401 Node->print(OSS); 402 } 403 404 if (OutStr[0] == '\n') OutStr.erase(OutStr.begin()); 405 406 // Process string output to make it nicer... 407 for (unsigned i = 0; i != OutStr.length(); ++i) 408 if (OutStr[i] == '\n') { // Left justify 409 OutStr[i] = '\\'; 410 OutStr.insert(OutStr.begin()+i+1, 'l'); 411 } 412 return OutStr; 413 } 414 }; 415 } 416 417 void MachineFunction::viewCFG() const 418 { 419 #ifndef NDEBUG 420 ViewGraph(this, "mf" + getName()); 421 #else 422 errs() << "MachineFunction::viewCFG is only available in debug builds on " 423 << "systems with Graphviz or gv!\n"; 424 #endif // NDEBUG 425 } 426 427 void MachineFunction::viewCFGOnly() const 428 { 429 #ifndef NDEBUG 430 ViewGraph(this, "mf" + getName(), true); 431 #else 432 errs() << "MachineFunction::viewCFGOnly is only available in debug builds on " 433 << "systems with Graphviz or gv!\n"; 434 #endif // NDEBUG 435 } 436 437 /// Add the specified physical register as a live-in value and 438 /// create a corresponding virtual register for it. 439 unsigned MachineFunction::addLiveIn(unsigned PReg, 440 const TargetRegisterClass *RC) { 441 MachineRegisterInfo &MRI = getRegInfo(); 442 unsigned VReg = MRI.getLiveInVirtReg(PReg); 443 if (VReg) { 444 const TargetRegisterClass *VRegRC = MRI.getRegClass(VReg); 445 (void)VRegRC; 446 // A physical register can be added several times. 447 // Between two calls, the register class of the related virtual register 448 // may have been constrained to match some operation constraints. 449 // In that case, check that the current register class includes the 450 // physical register and is a sub class of the specified RC. 451 assert((VRegRC == RC || (VRegRC->contains(PReg) && 452 RC->hasSubClassEq(VRegRC))) && 453 "Register class mismatch!"); 454 return VReg; 455 } 456 VReg = MRI.createVirtualRegister(RC); 457 MRI.addLiveIn(PReg, VReg); 458 return VReg; 459 } 460 461 /// Return the MCSymbol for the specified non-empty jump table. 462 /// If isLinkerPrivate is specified, an 'l' label is returned, otherwise a 463 /// normal 'L' label is returned. 464 MCSymbol *MachineFunction::getJTISymbol(unsigned JTI, MCContext &Ctx, 465 bool isLinkerPrivate) const { 466 const DataLayout &DL = getDataLayout(); 467 assert(JumpTableInfo && "No jump tables"); 468 assert(JTI < JumpTableInfo->getJumpTables().size() && "Invalid JTI!"); 469 470 const char *Prefix = isLinkerPrivate ? DL.getLinkerPrivateGlobalPrefix() 471 : DL.getPrivateGlobalPrefix(); 472 SmallString<60> Name; 473 raw_svector_ostream(Name) 474 << Prefix << "JTI" << getFunctionNumber() << '_' << JTI; 475 return Ctx.getOrCreateSymbol(Name); 476 } 477 478 /// Return a function-local symbol to represent the PIC base. 479 MCSymbol *MachineFunction::getPICBaseSymbol() const { 480 const DataLayout &DL = getDataLayout(); 481 return Ctx.getOrCreateSymbol(Twine(DL.getPrivateGlobalPrefix()) + 482 Twine(getFunctionNumber()) + "$pb"); 483 } 484 485 //===----------------------------------------------------------------------===// 486 // MachineFrameInfo implementation 487 //===----------------------------------------------------------------------===// 488 489 /// Make sure the function is at least Align bytes aligned. 490 void MachineFrameInfo::ensureMaxAlignment(unsigned Align) { 491 if (!StackRealignable || !RealignOption) 492 assert(Align <= StackAlignment && 493 "For targets without stack realignment, Align is out of limit!"); 494 if (MaxAlignment < Align) MaxAlignment = Align; 495 } 496 497 /// Clamp the alignment if requested and emit a warning. 498 static inline unsigned clampStackAlignment(bool ShouldClamp, unsigned Align, 499 unsigned StackAlign) { 500 if (!ShouldClamp || Align <= StackAlign) 501 return Align; 502 DEBUG(dbgs() << "Warning: requested alignment " << Align 503 << " exceeds the stack alignment " << StackAlign 504 << " when stack realignment is off" << '\n'); 505 return StackAlign; 506 } 507 508 /// Create a new statically sized stack object, returning a nonnegative 509 /// identifier to represent it. 510 int MachineFrameInfo::CreateStackObject(uint64_t Size, unsigned Alignment, 511 bool isSS, const AllocaInst *Alloca) { 512 assert(Size != 0 && "Cannot allocate zero size stack objects!"); 513 Alignment = clampStackAlignment(!StackRealignable || !RealignOption, 514 Alignment, StackAlignment); 515 Objects.push_back(StackObject(Size, Alignment, 0, false, isSS, Alloca, 516 !isSS)); 517 int Index = (int)Objects.size() - NumFixedObjects - 1; 518 assert(Index >= 0 && "Bad frame index!"); 519 ensureMaxAlignment(Alignment); 520 return Index; 521 } 522 523 /// Create a new statically sized stack object that represents a spill slot, 524 /// returning a nonnegative identifier to represent it. 525 int MachineFrameInfo::CreateSpillStackObject(uint64_t Size, 526 unsigned Alignment) { 527 Alignment = clampStackAlignment(!StackRealignable || !RealignOption, 528 Alignment, StackAlignment); 529 CreateStackObject(Size, Alignment, true); 530 int Index = (int)Objects.size() - NumFixedObjects - 1; 531 ensureMaxAlignment(Alignment); 532 return Index; 533 } 534 535 /// Notify the MachineFrameInfo object that a variable sized object has been 536 /// created. This must be created whenever a variable sized object is created, 537 /// whether or not the index returned is actually used. 538 int MachineFrameInfo::CreateVariableSizedObject(unsigned Alignment, 539 const AllocaInst *Alloca) { 540 HasVarSizedObjects = true; 541 Alignment = clampStackAlignment(!StackRealignable || !RealignOption, 542 Alignment, StackAlignment); 543 Objects.push_back(StackObject(0, Alignment, 0, false, false, Alloca, true)); 544 ensureMaxAlignment(Alignment); 545 return (int)Objects.size()-NumFixedObjects-1; 546 } 547 548 /// Create a new object at a fixed location on the stack. 549 /// All fixed objects should be created before other objects are created for 550 /// efficiency. By default, fixed objects are immutable. This returns an 551 /// index with a negative value. 552 int MachineFrameInfo::CreateFixedObject(uint64_t Size, int64_t SPOffset, 553 bool Immutable, bool isAliased) { 554 assert(Size != 0 && "Cannot allocate zero size fixed stack objects!"); 555 // The alignment of the frame index can be determined from its offset from 556 // the incoming frame position. If the frame object is at offset 32 and 557 // the stack is guaranteed to be 16-byte aligned, then we know that the 558 // object is 16-byte aligned. 559 unsigned Align = MinAlign(SPOffset, StackAlignment); 560 Align = clampStackAlignment(!StackRealignable || !RealignOption, Align, 561 StackAlignment); 562 Objects.insert(Objects.begin(), StackObject(Size, Align, SPOffset, Immutable, 563 /*isSS*/ false, 564 /*Alloca*/ nullptr, isAliased)); 565 return -++NumFixedObjects; 566 } 567 568 /// Create a spill slot at a fixed location on the stack. 569 /// Returns an index with a negative value. 570 int MachineFrameInfo::CreateFixedSpillStackObject(uint64_t Size, 571 int64_t SPOffset) { 572 unsigned Align = MinAlign(SPOffset, StackAlignment); 573 Align = clampStackAlignment(!StackRealignable || !RealignOption, Align, 574 StackAlignment); 575 Objects.insert(Objects.begin(), StackObject(Size, Align, SPOffset, 576 /*Immutable*/ true, 577 /*isSS*/ true, 578 /*Alloca*/ nullptr, 579 /*isAliased*/ false)); 580 return -++NumFixedObjects; 581 } 582 583 BitVector MachineFrameInfo::getPristineRegs(const MachineFunction &MF) const { 584 const TargetRegisterInfo *TRI = MF.getSubtarget().getRegisterInfo(); 585 BitVector BV(TRI->getNumRegs()); 586 587 // Before CSI is calculated, no registers are considered pristine. They can be 588 // freely used and PEI will make sure they are saved. 589 if (!isCalleeSavedInfoValid()) 590 return BV; 591 592 for (const MCPhysReg *CSR = TRI->getCalleeSavedRegs(&MF); CSR && *CSR; ++CSR) 593 BV.set(*CSR); 594 595 // Saved CSRs are not pristine. 596 const std::vector<CalleeSavedInfo> &CSI = getCalleeSavedInfo(); 597 for (std::vector<CalleeSavedInfo>::const_iterator I = CSI.begin(), 598 E = CSI.end(); I != E; ++I) 599 BV.reset(I->getReg()); 600 601 return BV; 602 } 603 604 unsigned MachineFrameInfo::estimateStackSize(const MachineFunction &MF) const { 605 const TargetFrameLowering *TFI = MF.getSubtarget().getFrameLowering(); 606 const TargetRegisterInfo *RegInfo = MF.getSubtarget().getRegisterInfo(); 607 unsigned MaxAlign = getMaxAlignment(); 608 int Offset = 0; 609 610 // This code is very, very similar to PEI::calculateFrameObjectOffsets(). 611 // It really should be refactored to share code. Until then, changes 612 // should keep in mind that there's tight coupling between the two. 613 614 for (int i = getObjectIndexBegin(); i != 0; ++i) { 615 int FixedOff = -getObjectOffset(i); 616 if (FixedOff > Offset) Offset = FixedOff; 617 } 618 for (unsigned i = 0, e = getObjectIndexEnd(); i != e; ++i) { 619 if (isDeadObjectIndex(i)) 620 continue; 621 Offset += getObjectSize(i); 622 unsigned Align = getObjectAlignment(i); 623 // Adjust to alignment boundary 624 Offset = (Offset+Align-1)/Align*Align; 625 626 MaxAlign = std::max(Align, MaxAlign); 627 } 628 629 if (adjustsStack() && TFI->hasReservedCallFrame(MF)) 630 Offset += getMaxCallFrameSize(); 631 632 // Round up the size to a multiple of the alignment. If the function has 633 // any calls or alloca's, align to the target's StackAlignment value to 634 // ensure that the callee's frame or the alloca data is suitably aligned; 635 // otherwise, for leaf functions, align to the TransientStackAlignment 636 // value. 637 unsigned StackAlign; 638 if (adjustsStack() || hasVarSizedObjects() || 639 (RegInfo->needsStackRealignment(MF) && getObjectIndexEnd() != 0)) 640 StackAlign = TFI->getStackAlignment(); 641 else 642 StackAlign = TFI->getTransientStackAlignment(); 643 644 // If the frame pointer is eliminated, all frame offsets will be relative to 645 // SP not FP. Align to MaxAlign so this works. 646 StackAlign = std::max(StackAlign, MaxAlign); 647 unsigned AlignMask = StackAlign - 1; 648 Offset = (Offset + AlignMask) & ~uint64_t(AlignMask); 649 650 return (unsigned)Offset; 651 } 652 653 void MachineFrameInfo::print(const MachineFunction &MF, raw_ostream &OS) const{ 654 if (Objects.empty()) return; 655 656 const TargetFrameLowering *FI = MF.getSubtarget().getFrameLowering(); 657 int ValOffset = (FI ? FI->getOffsetOfLocalArea() : 0); 658 659 OS << "Frame Objects:\n"; 660 661 for (unsigned i = 0, e = Objects.size(); i != e; ++i) { 662 const StackObject &SO = Objects[i]; 663 OS << " fi#" << (int)(i-NumFixedObjects) << ": "; 664 if (SO.Size == ~0ULL) { 665 OS << "dead\n"; 666 continue; 667 } 668 if (SO.Size == 0) 669 OS << "variable sized"; 670 else 671 OS << "size=" << SO.Size; 672 OS << ", align=" << SO.Alignment; 673 674 if (i < NumFixedObjects) 675 OS << ", fixed"; 676 if (i < NumFixedObjects || SO.SPOffset != -1) { 677 int64_t Off = SO.SPOffset - ValOffset; 678 OS << ", at location [SP"; 679 if (Off > 0) 680 OS << "+" << Off; 681 else if (Off < 0) 682 OS << Off; 683 OS << "]"; 684 } 685 OS << "\n"; 686 } 687 } 688 689 #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP) 690 void MachineFrameInfo::dump(const MachineFunction &MF) const { 691 print(MF, dbgs()); 692 } 693 #endif 694 695 //===----------------------------------------------------------------------===// 696 // MachineJumpTableInfo implementation 697 //===----------------------------------------------------------------------===// 698 699 /// Return the size of each entry in the jump table. 700 unsigned MachineJumpTableInfo::getEntrySize(const DataLayout &TD) const { 701 // The size of a jump table entry is 4 bytes unless the entry is just the 702 // address of a block, in which case it is the pointer size. 703 switch (getEntryKind()) { 704 case MachineJumpTableInfo::EK_BlockAddress: 705 return TD.getPointerSize(); 706 case MachineJumpTableInfo::EK_GPRel64BlockAddress: 707 return 8; 708 case MachineJumpTableInfo::EK_GPRel32BlockAddress: 709 case MachineJumpTableInfo::EK_LabelDifference32: 710 case MachineJumpTableInfo::EK_Custom32: 711 return 4; 712 case MachineJumpTableInfo::EK_Inline: 713 return 0; 714 } 715 llvm_unreachable("Unknown jump table encoding!"); 716 } 717 718 /// Return the alignment of each entry in the jump table. 719 unsigned MachineJumpTableInfo::getEntryAlignment(const DataLayout &TD) const { 720 // The alignment of a jump table entry is the alignment of int32 unless the 721 // entry is just the address of a block, in which case it is the pointer 722 // alignment. 723 switch (getEntryKind()) { 724 case MachineJumpTableInfo::EK_BlockAddress: 725 return TD.getPointerABIAlignment(); 726 case MachineJumpTableInfo::EK_GPRel64BlockAddress: 727 return TD.getABIIntegerTypeAlignment(64); 728 case MachineJumpTableInfo::EK_GPRel32BlockAddress: 729 case MachineJumpTableInfo::EK_LabelDifference32: 730 case MachineJumpTableInfo::EK_Custom32: 731 return TD.getABIIntegerTypeAlignment(32); 732 case MachineJumpTableInfo::EK_Inline: 733 return 1; 734 } 735 llvm_unreachable("Unknown jump table encoding!"); 736 } 737 738 /// Create a new jump table entry in the jump table info. 739 unsigned MachineJumpTableInfo::createJumpTableIndex( 740 const std::vector<MachineBasicBlock*> &DestBBs) { 741 assert(!DestBBs.empty() && "Cannot create an empty jump table!"); 742 JumpTables.push_back(MachineJumpTableEntry(DestBBs)); 743 return JumpTables.size()-1; 744 } 745 746 /// If Old is the target of any jump tables, update the jump tables to branch 747 /// to New instead. 748 bool MachineJumpTableInfo::ReplaceMBBInJumpTables(MachineBasicBlock *Old, 749 MachineBasicBlock *New) { 750 assert(Old != New && "Not making a change?"); 751 bool MadeChange = false; 752 for (size_t i = 0, e = JumpTables.size(); i != e; ++i) 753 ReplaceMBBInJumpTable(i, Old, New); 754 return MadeChange; 755 } 756 757 /// If Old is a target of the jump tables, update the jump table to branch to 758 /// New instead. 759 bool MachineJumpTableInfo::ReplaceMBBInJumpTable(unsigned Idx, 760 MachineBasicBlock *Old, 761 MachineBasicBlock *New) { 762 assert(Old != New && "Not making a change?"); 763 bool MadeChange = false; 764 MachineJumpTableEntry &JTE = JumpTables[Idx]; 765 for (size_t j = 0, e = JTE.MBBs.size(); j != e; ++j) 766 if (JTE.MBBs[j] == Old) { 767 JTE.MBBs[j] = New; 768 MadeChange = true; 769 } 770 return MadeChange; 771 } 772 773 void MachineJumpTableInfo::print(raw_ostream &OS) const { 774 if (JumpTables.empty()) return; 775 776 OS << "Jump Tables:\n"; 777 778 for (unsigned i = 0, e = JumpTables.size(); i != e; ++i) { 779 OS << " jt#" << i << ": "; 780 for (unsigned j = 0, f = JumpTables[i].MBBs.size(); j != f; ++j) 781 OS << " BB#" << JumpTables[i].MBBs[j]->getNumber(); 782 } 783 784 OS << '\n'; 785 } 786 787 #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP) 788 void MachineJumpTableInfo::dump() const { print(dbgs()); } 789 #endif 790 791 792 //===----------------------------------------------------------------------===// 793 // MachineConstantPool implementation 794 //===----------------------------------------------------------------------===// 795 796 void MachineConstantPoolValue::anchor() { } 797 798 Type *MachineConstantPoolEntry::getType() const { 799 if (isMachineConstantPoolEntry()) 800 return Val.MachineCPVal->getType(); 801 return Val.ConstVal->getType(); 802 } 803 804 805 unsigned MachineConstantPoolEntry::getRelocationInfo() const { 806 if (isMachineConstantPoolEntry()) 807 return Val.MachineCPVal->getRelocationInfo(); 808 return Val.ConstVal->getRelocationInfo(); 809 } 810 811 SectionKind 812 MachineConstantPoolEntry::getSectionKind(const DataLayout *DL) const { 813 SectionKind Kind; 814 switch (getRelocationInfo()) { 815 default: 816 llvm_unreachable("Unknown section kind"); 817 case Constant::GlobalRelocations: 818 Kind = SectionKind::getReadOnlyWithRel(); 819 break; 820 case Constant::LocalRelocation: 821 Kind = SectionKind::getReadOnlyWithRelLocal(); 822 break; 823 case Constant::NoRelocation: 824 switch (DL->getTypeAllocSize(getType())) { 825 case 4: 826 Kind = SectionKind::getMergeableConst4(); 827 break; 828 case 8: 829 Kind = SectionKind::getMergeableConst8(); 830 break; 831 case 16: 832 Kind = SectionKind::getMergeableConst16(); 833 break; 834 default: 835 Kind = SectionKind::getReadOnly(); 836 break; 837 } 838 } 839 return Kind; 840 } 841 842 MachineConstantPool::~MachineConstantPool() { 843 for (unsigned i = 0, e = Constants.size(); i != e; ++i) 844 if (Constants[i].isMachineConstantPoolEntry()) 845 delete Constants[i].Val.MachineCPVal; 846 for (DenseSet<MachineConstantPoolValue*>::iterator I = 847 MachineCPVsSharingEntries.begin(), E = MachineCPVsSharingEntries.end(); 848 I != E; ++I) 849 delete *I; 850 } 851 852 /// Test whether the given two constants can be allocated the same constant pool 853 /// entry. 854 static bool CanShareConstantPoolEntry(const Constant *A, const Constant *B, 855 const DataLayout &DL) { 856 // Handle the trivial case quickly. 857 if (A == B) return true; 858 859 // If they have the same type but weren't the same constant, quickly 860 // reject them. 861 if (A->getType() == B->getType()) return false; 862 863 // We can't handle structs or arrays. 864 if (isa<StructType>(A->getType()) || isa<ArrayType>(A->getType()) || 865 isa<StructType>(B->getType()) || isa<ArrayType>(B->getType())) 866 return false; 867 868 // For now, only support constants with the same size. 869 uint64_t StoreSize = DL.getTypeStoreSize(A->getType()); 870 if (StoreSize != DL.getTypeStoreSize(B->getType()) || StoreSize > 128) 871 return false; 872 873 Type *IntTy = IntegerType::get(A->getContext(), StoreSize*8); 874 875 // Try constant folding a bitcast of both instructions to an integer. If we 876 // get two identical ConstantInt's, then we are good to share them. We use 877 // the constant folding APIs to do this so that we get the benefit of 878 // DataLayout. 879 if (isa<PointerType>(A->getType())) 880 A = ConstantFoldInstOperands(Instruction::PtrToInt, IntTy, 881 const_cast<Constant *>(A), DL); 882 else if (A->getType() != IntTy) 883 A = ConstantFoldInstOperands(Instruction::BitCast, IntTy, 884 const_cast<Constant *>(A), DL); 885 if (isa<PointerType>(B->getType())) 886 B = ConstantFoldInstOperands(Instruction::PtrToInt, IntTy, 887 const_cast<Constant *>(B), DL); 888 else if (B->getType() != IntTy) 889 B = ConstantFoldInstOperands(Instruction::BitCast, IntTy, 890 const_cast<Constant *>(B), DL); 891 892 return A == B; 893 } 894 895 /// Create a new entry in the constant pool or return an existing one. 896 /// User must specify the log2 of the minimum required alignment for the object. 897 unsigned MachineConstantPool::getConstantPoolIndex(const Constant *C, 898 unsigned Alignment) { 899 assert(Alignment && "Alignment must be specified!"); 900 if (Alignment > PoolAlignment) PoolAlignment = Alignment; 901 902 // Check to see if we already have this constant. 903 // 904 // FIXME, this could be made much more efficient for large constant pools. 905 for (unsigned i = 0, e = Constants.size(); i != e; ++i) 906 if (!Constants[i].isMachineConstantPoolEntry() && 907 CanShareConstantPoolEntry(Constants[i].Val.ConstVal, C, DL)) { 908 if ((unsigned)Constants[i].getAlignment() < Alignment) 909 Constants[i].Alignment = Alignment; 910 return i; 911 } 912 913 Constants.push_back(MachineConstantPoolEntry(C, Alignment)); 914 return Constants.size()-1; 915 } 916 917 unsigned MachineConstantPool::getConstantPoolIndex(MachineConstantPoolValue *V, 918 unsigned Alignment) { 919 assert(Alignment && "Alignment must be specified!"); 920 if (Alignment > PoolAlignment) PoolAlignment = Alignment; 921 922 // Check to see if we already have this constant. 923 // 924 // FIXME, this could be made much more efficient for large constant pools. 925 int Idx = V->getExistingMachineCPValue(this, Alignment); 926 if (Idx != -1) { 927 MachineCPVsSharingEntries.insert(V); 928 return (unsigned)Idx; 929 } 930 931 Constants.push_back(MachineConstantPoolEntry(V, Alignment)); 932 return Constants.size()-1; 933 } 934 935 void MachineConstantPool::print(raw_ostream &OS) const { 936 if (Constants.empty()) return; 937 938 OS << "Constant Pool:\n"; 939 for (unsigned i = 0, e = Constants.size(); i != e; ++i) { 940 OS << " cp#" << i << ": "; 941 if (Constants[i].isMachineConstantPoolEntry()) 942 Constants[i].Val.MachineCPVal->print(OS); 943 else 944 Constants[i].Val.ConstVal->printAsOperand(OS, /*PrintType=*/false); 945 OS << ", align=" << Constants[i].getAlignment(); 946 OS << "\n"; 947 } 948 } 949 950 #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP) 951 void MachineConstantPool::dump() const { print(dbgs()); } 952 #endif 953