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/Function.h" 18 #include "llvm/CodeGen/MachineConstantPool.h" 19 #include "llvm/CodeGen/MachineFunctionPass.h" 20 #include "llvm/CodeGen/MachineFrameInfo.h" 21 #include "llvm/CodeGen/MachineInstr.h" 22 #include "llvm/CodeGen/MachineJumpTableInfo.h" 23 #include "llvm/CodeGen/MachineModuleInfo.h" 24 #include "llvm/CodeGen/MachineRegisterInfo.h" 25 #include "llvm/CodeGen/Passes.h" 26 #include "llvm/MC/MCAsmInfo.h" 27 #include "llvm/MC/MCContext.h" 28 #include "llvm/Analysis/ConstantFolding.h" 29 #include "llvm/Analysis/DebugInfo.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 void MachineFunction::dump() const { 288 print(dbgs()); 289 } 290 291 void MachineFunction::print(raw_ostream &OS, SlotIndexes *Indexes) const { 292 OS << "# Machine code for function " << Fn->getName() << ": "; 293 if (RegInfo) { 294 OS << (RegInfo->isSSA() ? "SSA" : "Post SSA"); 295 if (!RegInfo->tracksLiveness()) 296 OS << ", not tracking liveness"; 297 } 298 OS << '\n'; 299 300 // Print Frame Information 301 FrameInfo->print(*this, OS); 302 303 // Print JumpTable Information 304 if (JumpTableInfo) 305 JumpTableInfo->print(OS); 306 307 // Print Constant Pool 308 ConstantPool->print(OS); 309 310 const TargetRegisterInfo *TRI = getTarget().getRegisterInfo(); 311 312 if (RegInfo && !RegInfo->livein_empty()) { 313 OS << "Function Live Ins: "; 314 for (MachineRegisterInfo::livein_iterator 315 I = RegInfo->livein_begin(), E = RegInfo->livein_end(); I != E; ++I) { 316 OS << PrintReg(I->first, TRI); 317 if (I->second) 318 OS << " in " << PrintReg(I->second, TRI); 319 if (llvm::next(I) != E) 320 OS << ", "; 321 } 322 OS << '\n'; 323 } 324 if (RegInfo && !RegInfo->liveout_empty()) { 325 OS << "Function Live Outs:"; 326 for (MachineRegisterInfo::liveout_iterator 327 I = RegInfo->liveout_begin(), E = RegInfo->liveout_end(); I != E; ++I) 328 OS << ' ' << PrintReg(*I, TRI); 329 OS << '\n'; 330 } 331 332 for (const_iterator BB = begin(), E = end(); BB != E; ++BB) { 333 OS << '\n'; 334 BB->print(OS, Indexes); 335 } 336 337 OS << "\n# End machine code for function " << Fn->getName() << ".\n\n"; 338 } 339 340 namespace llvm { 341 template<> 342 struct DOTGraphTraits<const MachineFunction*> : public DefaultDOTGraphTraits { 343 344 DOTGraphTraits (bool isSimple=false) : DefaultDOTGraphTraits(isSimple) {} 345 346 static std::string getGraphName(const MachineFunction *F) { 347 return "CFG for '" + F->getFunction()->getName().str() + "' function"; 348 } 349 350 std::string getNodeLabel(const MachineBasicBlock *Node, 351 const MachineFunction *Graph) { 352 std::string OutStr; 353 { 354 raw_string_ostream OSS(OutStr); 355 356 if (isSimple()) { 357 OSS << "BB#" << Node->getNumber(); 358 if (const BasicBlock *BB = Node->getBasicBlock()) 359 OSS << ": " << BB->getName(); 360 } else 361 Node->print(OSS); 362 } 363 364 if (OutStr[0] == '\n') OutStr.erase(OutStr.begin()); 365 366 // Process string output to make it nicer... 367 for (unsigned i = 0; i != OutStr.length(); ++i) 368 if (OutStr[i] == '\n') { // Left justify 369 OutStr[i] = '\\'; 370 OutStr.insert(OutStr.begin()+i+1, 'l'); 371 } 372 return OutStr; 373 } 374 }; 375 } 376 377 void MachineFunction::viewCFG() const 378 { 379 #ifndef NDEBUG 380 ViewGraph(this, "mf" + getFunction()->getName()); 381 #else 382 errs() << "MachineFunction::viewCFG is only available in debug builds on " 383 << "systems with Graphviz or gv!\n"; 384 #endif // NDEBUG 385 } 386 387 void MachineFunction::viewCFGOnly() const 388 { 389 #ifndef NDEBUG 390 ViewGraph(this, "mf" + getFunction()->getName(), true); 391 #else 392 errs() << "MachineFunction::viewCFGOnly is only available in debug builds on " 393 << "systems with Graphviz or gv!\n"; 394 #endif // NDEBUG 395 } 396 397 /// addLiveIn - Add the specified physical register as a live-in value and 398 /// create a corresponding virtual register for it. 399 unsigned MachineFunction::addLiveIn(unsigned PReg, 400 const TargetRegisterClass *RC) { 401 MachineRegisterInfo &MRI = getRegInfo(); 402 unsigned VReg = MRI.getLiveInVirtReg(PReg); 403 if (VReg) { 404 assert(MRI.getRegClass(VReg) == RC && "Register class mismatch!"); 405 return VReg; 406 } 407 VReg = MRI.createVirtualRegister(RC); 408 MRI.addLiveIn(PReg, VReg); 409 return VReg; 410 } 411 412 /// getJTISymbol - Return the MCSymbol for the specified non-empty jump table. 413 /// If isLinkerPrivate is specified, an 'l' label is returned, otherwise a 414 /// normal 'L' label is returned. 415 MCSymbol *MachineFunction::getJTISymbol(unsigned JTI, MCContext &Ctx, 416 bool isLinkerPrivate) const { 417 assert(JumpTableInfo && "No jump tables"); 418 assert(JTI < JumpTableInfo->getJumpTables().size() && "Invalid JTI!"); 419 const MCAsmInfo &MAI = *getTarget().getMCAsmInfo(); 420 421 const char *Prefix = isLinkerPrivate ? MAI.getLinkerPrivateGlobalPrefix() : 422 MAI.getPrivateGlobalPrefix(); 423 SmallString<60> Name; 424 raw_svector_ostream(Name) 425 << Prefix << "JTI" << getFunctionNumber() << '_' << JTI; 426 return Ctx.GetOrCreateSymbol(Name.str()); 427 } 428 429 /// getPICBaseSymbol - Return a function-local symbol to represent the PIC 430 /// base. 431 MCSymbol *MachineFunction::getPICBaseSymbol() const { 432 const MCAsmInfo &MAI = *Target.getMCAsmInfo(); 433 return Ctx.GetOrCreateSymbol(Twine(MAI.getPrivateGlobalPrefix())+ 434 Twine(getFunctionNumber())+"$pb"); 435 } 436 437 //===----------------------------------------------------------------------===// 438 // MachineFrameInfo implementation 439 //===----------------------------------------------------------------------===// 440 441 /// CreateFixedObject - Create a new object at a fixed location on the stack. 442 /// All fixed objects should be created before other objects are created for 443 /// efficiency. By default, fixed objects are immutable. This returns an 444 /// index with a negative value. 445 /// 446 int MachineFrameInfo::CreateFixedObject(uint64_t Size, int64_t SPOffset, 447 bool Immutable) { 448 assert(Size != 0 && "Cannot allocate zero size fixed stack objects!"); 449 // The alignment of the frame index can be determined from its offset from 450 // the incoming frame position. If the frame object is at offset 32 and 451 // the stack is guaranteed to be 16-byte aligned, then we know that the 452 // object is 16-byte aligned. 453 unsigned StackAlign = TFI.getStackAlignment(); 454 unsigned Align = MinAlign(SPOffset, StackAlign); 455 Objects.insert(Objects.begin(), StackObject(Size, Align, SPOffset, Immutable, 456 /*isSS*/false, false)); 457 return -++NumFixedObjects; 458 } 459 460 461 BitVector 462 MachineFrameInfo::getPristineRegs(const MachineBasicBlock *MBB) const { 463 assert(MBB && "MBB must be valid"); 464 const MachineFunction *MF = MBB->getParent(); 465 assert(MF && "MBB must be part of a MachineFunction"); 466 const TargetMachine &TM = MF->getTarget(); 467 const TargetRegisterInfo *TRI = TM.getRegisterInfo(); 468 BitVector BV(TRI->getNumRegs()); 469 470 // Before CSI is calculated, no registers are considered pristine. They can be 471 // freely used and PEI will make sure they are saved. 472 if (!isCalleeSavedInfoValid()) 473 return BV; 474 475 for (const uint16_t *CSR = TRI->getCalleeSavedRegs(MF); CSR && *CSR; ++CSR) 476 BV.set(*CSR); 477 478 // The entry MBB always has all CSRs pristine. 479 if (MBB == &MF->front()) 480 return BV; 481 482 // On other MBBs the saved CSRs are not pristine. 483 const std::vector<CalleeSavedInfo> &CSI = getCalleeSavedInfo(); 484 for (std::vector<CalleeSavedInfo>::const_iterator I = CSI.begin(), 485 E = CSI.end(); I != E; ++I) 486 BV.reset(I->getReg()); 487 488 return BV; 489 } 490 491 492 void MachineFrameInfo::print(const MachineFunction &MF, raw_ostream &OS) const{ 493 if (Objects.empty()) return; 494 495 const TargetFrameLowering *FI = MF.getTarget().getFrameLowering(); 496 int ValOffset = (FI ? FI->getOffsetOfLocalArea() : 0); 497 498 OS << "Frame Objects:\n"; 499 500 for (unsigned i = 0, e = Objects.size(); i != e; ++i) { 501 const StackObject &SO = Objects[i]; 502 OS << " fi#" << (int)(i-NumFixedObjects) << ": "; 503 if (SO.Size == ~0ULL) { 504 OS << "dead\n"; 505 continue; 506 } 507 if (SO.Size == 0) 508 OS << "variable sized"; 509 else 510 OS << "size=" << SO.Size; 511 OS << ", align=" << SO.Alignment; 512 513 if (i < NumFixedObjects) 514 OS << ", fixed"; 515 if (i < NumFixedObjects || SO.SPOffset != -1) { 516 int64_t Off = SO.SPOffset - ValOffset; 517 OS << ", at location [SP"; 518 if (Off > 0) 519 OS << "+" << Off; 520 else if (Off < 0) 521 OS << Off; 522 OS << "]"; 523 } 524 OS << "\n"; 525 } 526 } 527 528 void MachineFrameInfo::dump(const MachineFunction &MF) const { 529 print(MF, dbgs()); 530 } 531 532 //===----------------------------------------------------------------------===// 533 // MachineJumpTableInfo implementation 534 //===----------------------------------------------------------------------===// 535 536 /// getEntrySize - Return the size of each entry in the jump table. 537 unsigned MachineJumpTableInfo::getEntrySize(const TargetData &TD) const { 538 // The size of a jump table entry is 4 bytes unless the entry is just the 539 // address of a block, in which case it is the pointer size. 540 switch (getEntryKind()) { 541 case MachineJumpTableInfo::EK_BlockAddress: 542 return TD.getPointerSize(); 543 case MachineJumpTableInfo::EK_GPRel64BlockAddress: 544 return 8; 545 case MachineJumpTableInfo::EK_GPRel32BlockAddress: 546 case MachineJumpTableInfo::EK_LabelDifference32: 547 case MachineJumpTableInfo::EK_Custom32: 548 return 4; 549 case MachineJumpTableInfo::EK_Inline: 550 return 0; 551 } 552 llvm_unreachable("Unknown jump table encoding!"); 553 } 554 555 /// getEntryAlignment - Return the alignment of each entry in the jump table. 556 unsigned MachineJumpTableInfo::getEntryAlignment(const TargetData &TD) const { 557 // The alignment of a jump table entry is the alignment of int32 unless the 558 // entry is just the address of a block, in which case it is the pointer 559 // alignment. 560 switch (getEntryKind()) { 561 case MachineJumpTableInfo::EK_BlockAddress: 562 return TD.getPointerABIAlignment(); 563 case MachineJumpTableInfo::EK_GPRel64BlockAddress: 564 return TD.getABIIntegerTypeAlignment(64); 565 case MachineJumpTableInfo::EK_GPRel32BlockAddress: 566 case MachineJumpTableInfo::EK_LabelDifference32: 567 case MachineJumpTableInfo::EK_Custom32: 568 return TD.getABIIntegerTypeAlignment(32); 569 case MachineJumpTableInfo::EK_Inline: 570 return 1; 571 } 572 llvm_unreachable("Unknown jump table encoding!"); 573 } 574 575 /// createJumpTableIndex - Create a new jump table entry in the jump table info. 576 /// 577 unsigned MachineJumpTableInfo::createJumpTableIndex( 578 const std::vector<MachineBasicBlock*> &DestBBs) { 579 assert(!DestBBs.empty() && "Cannot create an empty jump table!"); 580 JumpTables.push_back(MachineJumpTableEntry(DestBBs)); 581 return JumpTables.size()-1; 582 } 583 584 /// ReplaceMBBInJumpTables - If Old is the target of any jump tables, update 585 /// the jump tables to branch to New instead. 586 bool MachineJumpTableInfo::ReplaceMBBInJumpTables(MachineBasicBlock *Old, 587 MachineBasicBlock *New) { 588 assert(Old != New && "Not making a change?"); 589 bool MadeChange = false; 590 for (size_t i = 0, e = JumpTables.size(); i != e; ++i) 591 ReplaceMBBInJumpTable(i, Old, New); 592 return MadeChange; 593 } 594 595 /// ReplaceMBBInJumpTable - If Old is a target of the jump tables, update 596 /// the jump table to branch to New instead. 597 bool MachineJumpTableInfo::ReplaceMBBInJumpTable(unsigned Idx, 598 MachineBasicBlock *Old, 599 MachineBasicBlock *New) { 600 assert(Old != New && "Not making a change?"); 601 bool MadeChange = false; 602 MachineJumpTableEntry &JTE = JumpTables[Idx]; 603 for (size_t j = 0, e = JTE.MBBs.size(); j != e; ++j) 604 if (JTE.MBBs[j] == Old) { 605 JTE.MBBs[j] = New; 606 MadeChange = true; 607 } 608 return MadeChange; 609 } 610 611 void MachineJumpTableInfo::print(raw_ostream &OS) const { 612 if (JumpTables.empty()) return; 613 614 OS << "Jump Tables:\n"; 615 616 for (unsigned i = 0, e = JumpTables.size(); i != e; ++i) { 617 OS << " jt#" << i << ": "; 618 for (unsigned j = 0, f = JumpTables[i].MBBs.size(); j != f; ++j) 619 OS << " BB#" << JumpTables[i].MBBs[j]->getNumber(); 620 } 621 622 OS << '\n'; 623 } 624 625 void MachineJumpTableInfo::dump() const { print(dbgs()); } 626 627 628 //===----------------------------------------------------------------------===// 629 // MachineConstantPool implementation 630 //===----------------------------------------------------------------------===// 631 632 void MachineConstantPoolValue::anchor() { } 633 634 Type *MachineConstantPoolEntry::getType() const { 635 if (isMachineConstantPoolEntry()) 636 return Val.MachineCPVal->getType(); 637 return Val.ConstVal->getType(); 638 } 639 640 641 unsigned MachineConstantPoolEntry::getRelocationInfo() const { 642 if (isMachineConstantPoolEntry()) 643 return Val.MachineCPVal->getRelocationInfo(); 644 return Val.ConstVal->getRelocationInfo(); 645 } 646 647 MachineConstantPool::~MachineConstantPool() { 648 for (unsigned i = 0, e = Constants.size(); i != e; ++i) 649 if (Constants[i].isMachineConstantPoolEntry()) 650 delete Constants[i].Val.MachineCPVal; 651 for (DenseSet<MachineConstantPoolValue*>::iterator I = 652 MachineCPVsSharingEntries.begin(), E = MachineCPVsSharingEntries.end(); 653 I != E; ++I) 654 delete *I; 655 } 656 657 /// CanShareConstantPoolEntry - Test whether the given two constants 658 /// can be allocated the same constant pool entry. 659 static bool CanShareConstantPoolEntry(const Constant *A, const Constant *B, 660 const TargetData *TD) { 661 // Handle the trivial case quickly. 662 if (A == B) return true; 663 664 // If they have the same type but weren't the same constant, quickly 665 // reject them. 666 if (A->getType() == B->getType()) return false; 667 668 // We can't handle structs or arrays. 669 if (isa<StructType>(A->getType()) || isa<ArrayType>(A->getType()) || 670 isa<StructType>(B->getType()) || isa<ArrayType>(B->getType())) 671 return false; 672 673 // For now, only support constants with the same size. 674 uint64_t StoreSize = TD->getTypeStoreSize(A->getType()); 675 if (StoreSize != TD->getTypeStoreSize(B->getType()) || 676 StoreSize > 128) 677 return false; 678 679 Type *IntTy = IntegerType::get(A->getContext(), StoreSize*8); 680 681 // Try constant folding a bitcast of both instructions to an integer. If we 682 // get two identical ConstantInt's, then we are good to share them. We use 683 // the constant folding APIs to do this so that we get the benefit of 684 // TargetData. 685 if (isa<PointerType>(A->getType())) 686 A = ConstantFoldInstOperands(Instruction::PtrToInt, IntTy, 687 const_cast<Constant*>(A), TD); 688 else if (A->getType() != IntTy) 689 A = ConstantFoldInstOperands(Instruction::BitCast, IntTy, 690 const_cast<Constant*>(A), TD); 691 if (isa<PointerType>(B->getType())) 692 B = ConstantFoldInstOperands(Instruction::PtrToInt, IntTy, 693 const_cast<Constant*>(B), TD); 694 else if (B->getType() != IntTy) 695 B = ConstantFoldInstOperands(Instruction::BitCast, IntTy, 696 const_cast<Constant*>(B), TD); 697 698 return A == B; 699 } 700 701 /// getConstantPoolIndex - Create a new entry in the constant pool or return 702 /// an existing one. User must specify the log2 of the minimum required 703 /// alignment for the object. 704 /// 705 unsigned MachineConstantPool::getConstantPoolIndex(const Constant *C, 706 unsigned Alignment) { 707 assert(Alignment && "Alignment must be specified!"); 708 if (Alignment > PoolAlignment) PoolAlignment = Alignment; 709 710 // Check to see if we already have this constant. 711 // 712 // FIXME, this could be made much more efficient for large constant pools. 713 for (unsigned i = 0, e = Constants.size(); i != e; ++i) 714 if (!Constants[i].isMachineConstantPoolEntry() && 715 CanShareConstantPoolEntry(Constants[i].Val.ConstVal, C, TD)) { 716 if ((unsigned)Constants[i].getAlignment() < Alignment) 717 Constants[i].Alignment = Alignment; 718 return i; 719 } 720 721 Constants.push_back(MachineConstantPoolEntry(C, Alignment)); 722 return Constants.size()-1; 723 } 724 725 unsigned MachineConstantPool::getConstantPoolIndex(MachineConstantPoolValue *V, 726 unsigned Alignment) { 727 assert(Alignment && "Alignment must be specified!"); 728 if (Alignment > PoolAlignment) PoolAlignment = Alignment; 729 730 // Check to see if we already have this constant. 731 // 732 // FIXME, this could be made much more efficient for large constant pools. 733 int Idx = V->getExistingMachineCPValue(this, Alignment); 734 if (Idx != -1) { 735 MachineCPVsSharingEntries.insert(V); 736 return (unsigned)Idx; 737 } 738 739 Constants.push_back(MachineConstantPoolEntry(V, Alignment)); 740 return Constants.size()-1; 741 } 742 743 void MachineConstantPool::print(raw_ostream &OS) const { 744 if (Constants.empty()) return; 745 746 OS << "Constant Pool:\n"; 747 for (unsigned i = 0, e = Constants.size(); i != e; ++i) { 748 OS << " cp#" << i << ": "; 749 if (Constants[i].isMachineConstantPoolEntry()) 750 Constants[i].Val.MachineCPVal->print(OS); 751 else 752 OS << *(Value*)Constants[i].Val.ConstVal; 753 OS << ", align=" << Constants[i].getAlignment(); 754 OS << "\n"; 755 } 756 } 757 758 void MachineConstantPool::dump() const { print(dbgs()); } 759