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