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/DebugInfo.h" 18 #include "llvm/Function.h" 19 #include "llvm/CodeGen/MachineConstantPool.h" 20 #include "llvm/CodeGen/MachineFunctionPass.h" 21 #include "llvm/CodeGen/MachineFrameInfo.h" 22 #include "llvm/CodeGen/MachineInstr.h" 23 #include "llvm/CodeGen/MachineJumpTableInfo.h" 24 #include "llvm/CodeGen/MachineModuleInfo.h" 25 #include "llvm/CodeGen/MachineRegisterInfo.h" 26 #include "llvm/CodeGen/Passes.h" 27 #include "llvm/MC/MCAsmInfo.h" 28 #include "llvm/MC/MCContext.h" 29 #include "llvm/Analysis/ConstantFolding.h" 30 #include "llvm/Support/Debug.h" 31 #include "llvm/Target/TargetData.h" 32 #include "llvm/Target/TargetLowering.h" 33 #include "llvm/Target/TargetMachine.h" 34 #include "llvm/Target/TargetFrameLowering.h" 35 #include "llvm/ADT/SmallString.h" 36 #include "llvm/ADT/STLExtras.h" 37 #include "llvm/Support/GraphWriter.h" 38 #include "llvm/Support/raw_ostream.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->hasFnAttr(Attribute::StackAlignment)) 63 FrameInfo->ensureMaxAlignment(Attribute::getStackAlignmentFromAttrs( 64 Fn->getAttributes().getFnAttributes())); 65 ConstantPool = new (Allocator) MachineConstantPool(TM.getTargetData()); 66 Alignment = TM.getTargetLowering()->getMinFunctionAlignment(); 67 // FIXME: Shouldn't use pref alignment if explicit alignment is set on Fn. 68 if (!Fn->hasFnAttr(Attribute::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 #ifndef NDEBUG 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 /// CreateFixedObject - Create a new object at a fixed location on the stack. 449 /// All fixed objects should be created before other objects are created for 450 /// efficiency. By default, fixed objects are immutable. This returns an 451 /// index with a negative value. 452 /// 453 int MachineFrameInfo::CreateFixedObject(uint64_t Size, int64_t SPOffset, 454 bool Immutable) { 455 assert(Size != 0 && "Cannot allocate zero size fixed stack objects!"); 456 // The alignment of the frame index can be determined from its offset from 457 // the incoming frame position. If the frame object is at offset 32 and 458 // the stack is guaranteed to be 16-byte aligned, then we know that the 459 // object is 16-byte aligned. 460 unsigned StackAlign = TFI.getStackAlignment(); 461 unsigned Align = MinAlign(SPOffset, StackAlign); 462 Objects.insert(Objects.begin(), StackObject(Size, Align, SPOffset, Immutable, 463 /*isSS*/ false, 464 /*NeedSP*/ false, 465 /*Alloca*/ 0)); 466 return -++NumFixedObjects; 467 } 468 469 470 BitVector 471 MachineFrameInfo::getPristineRegs(const MachineBasicBlock *MBB) const { 472 assert(MBB && "MBB must be valid"); 473 const MachineFunction *MF = MBB->getParent(); 474 assert(MF && "MBB must be part of a MachineFunction"); 475 const TargetMachine &TM = MF->getTarget(); 476 const TargetRegisterInfo *TRI = TM.getRegisterInfo(); 477 BitVector BV(TRI->getNumRegs()); 478 479 // Before CSI is calculated, no registers are considered pristine. They can be 480 // freely used and PEI will make sure they are saved. 481 if (!isCalleeSavedInfoValid()) 482 return BV; 483 484 for (const uint16_t *CSR = TRI->getCalleeSavedRegs(MF); CSR && *CSR; ++CSR) 485 BV.set(*CSR); 486 487 // The entry MBB always has all CSRs pristine. 488 if (MBB == &MF->front()) 489 return BV; 490 491 // On other MBBs the saved CSRs are not pristine. 492 const std::vector<CalleeSavedInfo> &CSI = getCalleeSavedInfo(); 493 for (std::vector<CalleeSavedInfo>::const_iterator I = CSI.begin(), 494 E = CSI.end(); I != E; ++I) 495 BV.reset(I->getReg()); 496 497 return BV; 498 } 499 500 501 void MachineFrameInfo::print(const MachineFunction &MF, raw_ostream &OS) const{ 502 if (Objects.empty()) return; 503 504 const TargetFrameLowering *FI = MF.getTarget().getFrameLowering(); 505 int ValOffset = (FI ? FI->getOffsetOfLocalArea() : 0); 506 507 OS << "Frame Objects:\n"; 508 509 for (unsigned i = 0, e = Objects.size(); i != e; ++i) { 510 const StackObject &SO = Objects[i]; 511 OS << " fi#" << (int)(i-NumFixedObjects) << ": "; 512 if (SO.Size == ~0ULL) { 513 OS << "dead\n"; 514 continue; 515 } 516 if (SO.Size == 0) 517 OS << "variable sized"; 518 else 519 OS << "size=" << SO.Size; 520 OS << ", align=" << SO.Alignment; 521 522 if (i < NumFixedObjects) 523 OS << ", fixed"; 524 if (i < NumFixedObjects || SO.SPOffset != -1) { 525 int64_t Off = SO.SPOffset - ValOffset; 526 OS << ", at location [SP"; 527 if (Off > 0) 528 OS << "+" << Off; 529 else if (Off < 0) 530 OS << Off; 531 OS << "]"; 532 } 533 OS << "\n"; 534 } 535 } 536 537 #ifndef NDEBUG 538 void MachineFrameInfo::dump(const MachineFunction &MF) const { 539 print(MF, dbgs()); 540 } 541 #endif 542 543 //===----------------------------------------------------------------------===// 544 // MachineJumpTableInfo implementation 545 //===----------------------------------------------------------------------===// 546 547 /// getEntrySize - Return the size of each entry in the jump table. 548 unsigned MachineJumpTableInfo::getEntrySize(const TargetData &TD) const { 549 // The size of a jump table entry is 4 bytes unless the entry is just the 550 // address of a block, in which case it is the pointer size. 551 switch (getEntryKind()) { 552 case MachineJumpTableInfo::EK_BlockAddress: 553 return TD.getPointerSize(); 554 case MachineJumpTableInfo::EK_GPRel64BlockAddress: 555 return 8; 556 case MachineJumpTableInfo::EK_GPRel32BlockAddress: 557 case MachineJumpTableInfo::EK_LabelDifference32: 558 case MachineJumpTableInfo::EK_Custom32: 559 return 4; 560 case MachineJumpTableInfo::EK_Inline: 561 return 0; 562 } 563 llvm_unreachable("Unknown jump table encoding!"); 564 } 565 566 /// getEntryAlignment - Return the alignment of each entry in the jump table. 567 unsigned MachineJumpTableInfo::getEntryAlignment(const TargetData &TD) const { 568 // The alignment of a jump table entry is the alignment of int32 unless the 569 // entry is just the address of a block, in which case it is the pointer 570 // alignment. 571 switch (getEntryKind()) { 572 case MachineJumpTableInfo::EK_BlockAddress: 573 return TD.getPointerABIAlignment(); 574 case MachineJumpTableInfo::EK_GPRel64BlockAddress: 575 return TD.getABIIntegerTypeAlignment(64); 576 case MachineJumpTableInfo::EK_GPRel32BlockAddress: 577 case MachineJumpTableInfo::EK_LabelDifference32: 578 case MachineJumpTableInfo::EK_Custom32: 579 return TD.getABIIntegerTypeAlignment(32); 580 case MachineJumpTableInfo::EK_Inline: 581 return 1; 582 } 583 llvm_unreachable("Unknown jump table encoding!"); 584 } 585 586 /// createJumpTableIndex - Create a new jump table entry in the jump table info. 587 /// 588 unsigned MachineJumpTableInfo::createJumpTableIndex( 589 const std::vector<MachineBasicBlock*> &DestBBs) { 590 assert(!DestBBs.empty() && "Cannot create an empty jump table!"); 591 JumpTables.push_back(MachineJumpTableEntry(DestBBs)); 592 return JumpTables.size()-1; 593 } 594 595 /// ReplaceMBBInJumpTables - If Old is the target of any jump tables, update 596 /// the jump tables to branch to New instead. 597 bool MachineJumpTableInfo::ReplaceMBBInJumpTables(MachineBasicBlock *Old, 598 MachineBasicBlock *New) { 599 assert(Old != New && "Not making a change?"); 600 bool MadeChange = false; 601 for (size_t i = 0, e = JumpTables.size(); i != e; ++i) 602 ReplaceMBBInJumpTable(i, Old, New); 603 return MadeChange; 604 } 605 606 /// ReplaceMBBInJumpTable - If Old is a target of the jump tables, update 607 /// the jump table to branch to New instead. 608 bool MachineJumpTableInfo::ReplaceMBBInJumpTable(unsigned Idx, 609 MachineBasicBlock *Old, 610 MachineBasicBlock *New) { 611 assert(Old != New && "Not making a change?"); 612 bool MadeChange = false; 613 MachineJumpTableEntry &JTE = JumpTables[Idx]; 614 for (size_t j = 0, e = JTE.MBBs.size(); j != e; ++j) 615 if (JTE.MBBs[j] == Old) { 616 JTE.MBBs[j] = New; 617 MadeChange = true; 618 } 619 return MadeChange; 620 } 621 622 void MachineJumpTableInfo::print(raw_ostream &OS) const { 623 if (JumpTables.empty()) return; 624 625 OS << "Jump Tables:\n"; 626 627 for (unsigned i = 0, e = JumpTables.size(); i != e; ++i) { 628 OS << " jt#" << i << ": "; 629 for (unsigned j = 0, f = JumpTables[i].MBBs.size(); j != f; ++j) 630 OS << " BB#" << JumpTables[i].MBBs[j]->getNumber(); 631 } 632 633 OS << '\n'; 634 } 635 636 #ifndef NDEBUG 637 void MachineJumpTableInfo::dump() const { print(dbgs()); } 638 #endif 639 640 641 //===----------------------------------------------------------------------===// 642 // MachineConstantPool implementation 643 //===----------------------------------------------------------------------===// 644 645 void MachineConstantPoolValue::anchor() { } 646 647 Type *MachineConstantPoolEntry::getType() const { 648 if (isMachineConstantPoolEntry()) 649 return Val.MachineCPVal->getType(); 650 return Val.ConstVal->getType(); 651 } 652 653 654 unsigned MachineConstantPoolEntry::getRelocationInfo() const { 655 if (isMachineConstantPoolEntry()) 656 return Val.MachineCPVal->getRelocationInfo(); 657 return Val.ConstVal->getRelocationInfo(); 658 } 659 660 MachineConstantPool::~MachineConstantPool() { 661 for (unsigned i = 0, e = Constants.size(); i != e; ++i) 662 if (Constants[i].isMachineConstantPoolEntry()) 663 delete Constants[i].Val.MachineCPVal; 664 for (DenseSet<MachineConstantPoolValue*>::iterator I = 665 MachineCPVsSharingEntries.begin(), E = MachineCPVsSharingEntries.end(); 666 I != E; ++I) 667 delete *I; 668 } 669 670 /// CanShareConstantPoolEntry - Test whether the given two constants 671 /// can be allocated the same constant pool entry. 672 static bool CanShareConstantPoolEntry(const Constant *A, const Constant *B, 673 const TargetData *TD) { 674 // Handle the trivial case quickly. 675 if (A == B) return true; 676 677 // If they have the same type but weren't the same constant, quickly 678 // reject them. 679 if (A->getType() == B->getType()) return false; 680 681 // We can't handle structs or arrays. 682 if (isa<StructType>(A->getType()) || isa<ArrayType>(A->getType()) || 683 isa<StructType>(B->getType()) || isa<ArrayType>(B->getType())) 684 return false; 685 686 // For now, only support constants with the same size. 687 uint64_t StoreSize = TD->getTypeStoreSize(A->getType()); 688 if (StoreSize != TD->getTypeStoreSize(B->getType()) || 689 StoreSize > 128) 690 return false; 691 692 Type *IntTy = IntegerType::get(A->getContext(), StoreSize*8); 693 694 // Try constant folding a bitcast of both instructions to an integer. If we 695 // get two identical ConstantInt's, then we are good to share them. We use 696 // the constant folding APIs to do this so that we get the benefit of 697 // TargetData. 698 if (isa<PointerType>(A->getType())) 699 A = ConstantFoldInstOperands(Instruction::PtrToInt, IntTy, 700 const_cast<Constant*>(A), TD); 701 else if (A->getType() != IntTy) 702 A = ConstantFoldInstOperands(Instruction::BitCast, IntTy, 703 const_cast<Constant*>(A), TD); 704 if (isa<PointerType>(B->getType())) 705 B = ConstantFoldInstOperands(Instruction::PtrToInt, IntTy, 706 const_cast<Constant*>(B), TD); 707 else if (B->getType() != IntTy) 708 B = ConstantFoldInstOperands(Instruction::BitCast, IntTy, 709 const_cast<Constant*>(B), TD); 710 711 return A == B; 712 } 713 714 /// getConstantPoolIndex - Create a new entry in the constant pool or return 715 /// an existing one. User must specify the log2 of the minimum required 716 /// alignment for the object. 717 /// 718 unsigned MachineConstantPool::getConstantPoolIndex(const Constant *C, 719 unsigned Alignment) { 720 assert(Alignment && "Alignment must be specified!"); 721 if (Alignment > PoolAlignment) PoolAlignment = Alignment; 722 723 // Check to see if we already have this constant. 724 // 725 // FIXME, this could be made much more efficient for large constant pools. 726 for (unsigned i = 0, e = Constants.size(); i != e; ++i) 727 if (!Constants[i].isMachineConstantPoolEntry() && 728 CanShareConstantPoolEntry(Constants[i].Val.ConstVal, C, TD)) { 729 if ((unsigned)Constants[i].getAlignment() < Alignment) 730 Constants[i].Alignment = Alignment; 731 return i; 732 } 733 734 Constants.push_back(MachineConstantPoolEntry(C, Alignment)); 735 return Constants.size()-1; 736 } 737 738 unsigned MachineConstantPool::getConstantPoolIndex(MachineConstantPoolValue *V, 739 unsigned Alignment) { 740 assert(Alignment && "Alignment must be specified!"); 741 if (Alignment > PoolAlignment) PoolAlignment = Alignment; 742 743 // Check to see if we already have this constant. 744 // 745 // FIXME, this could be made much more efficient for large constant pools. 746 int Idx = V->getExistingMachineCPValue(this, Alignment); 747 if (Idx != -1) { 748 MachineCPVsSharingEntries.insert(V); 749 return (unsigned)Idx; 750 } 751 752 Constants.push_back(MachineConstantPoolEntry(V, Alignment)); 753 return Constants.size()-1; 754 } 755 756 void MachineConstantPool::print(raw_ostream &OS) const { 757 if (Constants.empty()) return; 758 759 OS << "Constant Pool:\n"; 760 for (unsigned i = 0, e = Constants.size(); i != e; ++i) { 761 OS << " cp#" << i << ": "; 762 if (Constants[i].isMachineConstantPoolEntry()) 763 Constants[i].Val.MachineCPVal->print(OS); 764 else 765 OS << *(const Value*)Constants[i].Val.ConstVal; 766 OS << ", align=" << Constants[i].getAlignment(); 767 OS << "\n"; 768 } 769 } 770 771 #ifndef NDEBUG 772 void MachineConstantPool::dump() const { print(dbgs()); } 773 #endif 774