MachineFunction.cpp revision 1168d1d30803fd4449b36efba80b827d06b17fb3
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/DerivedTypes.h" 17#include "llvm/Function.h" 18#include "llvm/Instructions.h" 19#include "llvm/Config/config.h" 20#include "llvm/CodeGen/MachineConstantPool.h" 21#include "llvm/CodeGen/MachineFunction.h" 22#include "llvm/CodeGen/MachineFunctionPass.h" 23#include "llvm/CodeGen/MachineFrameInfo.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/MC/MCAsmInfo.h" 30#include "llvm/MC/MCContext.h" 31#include "llvm/Analysis/DebugInfo.h" 32#include "llvm/Support/Debug.h" 33#include "llvm/Target/TargetData.h" 34#include "llvm/Target/TargetLowering.h" 35#include "llvm/Target/TargetMachine.h" 36#include "llvm/Target/TargetFrameInfo.h" 37#include "llvm/ADT/SmallString.h" 38#include "llvm/ADT/STLExtras.h" 39#include "llvm/Support/GraphWriter.h" 40#include "llvm/Support/raw_ostream.h" 41using namespace llvm; 42 43//===----------------------------------------------------------------------===// 44// MachineFunction implementation 45//===----------------------------------------------------------------------===// 46 47// Out of line virtual method. 48MachineFunctionInfo::~MachineFunctionInfo() {} 49 50void ilist_traits<MachineBasicBlock>::deleteNode(MachineBasicBlock *MBB) { 51 MBB->getParent()->DeleteMachineBasicBlock(MBB); 52} 53 54MachineFunction::MachineFunction(Function *F, const TargetMachine &TM, 55 unsigned FunctionNum, MachineModuleInfo &mmi) 56 : Fn(F), Target(TM), Ctx(mmi.getContext()), MMI(mmi) { 57 if (TM.getRegisterInfo()) 58 RegInfo = new (Allocator) MachineRegisterInfo(*TM.getRegisterInfo()); 59 else 60 RegInfo = 0; 61 MFInfo = 0; 62 FrameInfo = new (Allocator) MachineFrameInfo(*TM.getFrameInfo()); 63 if (Fn->hasFnAttr(Attribute::StackAlignment)) 64 FrameInfo->setMaxAlignment(Attribute::getStackAlignmentFromAttrs( 65 Fn->getAttributes().getFnAttributes())); 66 ConstantPool = new (Allocator) MachineConstantPool(TM.getTargetData()); 67 Alignment = TM.getTargetLowering()->getFunctionAlignment(F); 68 FunctionNumber = FunctionNum; 69 JumpTableInfo = 0; 70} 71 72MachineFunction::~MachineFunction() { 73 BasicBlocks.clear(); 74 InstructionRecycler.clear(Allocator); 75 BasicBlockRecycler.clear(Allocator); 76 if (RegInfo) { 77 RegInfo->~MachineRegisterInfo(); 78 Allocator.Deallocate(RegInfo); 79 } 80 if (MFInfo) { 81 MFInfo->~MachineFunctionInfo(); 82 Allocator.Deallocate(MFInfo); 83 } 84 FrameInfo->~MachineFrameInfo(); Allocator.Deallocate(FrameInfo); 85 ConstantPool->~MachineConstantPool(); Allocator.Deallocate(ConstantPool); 86 87 if (JumpTableInfo) { 88 JumpTableInfo->~MachineJumpTableInfo(); 89 Allocator.Deallocate(JumpTableInfo); 90 } 91} 92 93/// getOrCreateJumpTableInfo - Get the JumpTableInfo for this function, if it 94/// does already exist, allocate one. 95MachineJumpTableInfo *MachineFunction:: 96getOrCreateJumpTableInfo(unsigned EntryKind) { 97 if (JumpTableInfo) return JumpTableInfo; 98 99 JumpTableInfo = new (Allocator) 100 MachineJumpTableInfo((MachineJumpTableInfo::JTEntryKind)EntryKind); 101 return JumpTableInfo; 102} 103 104/// RenumberBlocks - This discards all of the MachineBasicBlock numbers and 105/// recomputes them. This guarantees that the MBB numbers are sequential, 106/// dense, and match the ordering of the blocks within the function. If a 107/// specific MachineBasicBlock is specified, only that block and those after 108/// it are renumbered. 109void MachineFunction::RenumberBlocks(MachineBasicBlock *MBB) { 110 if (empty()) { MBBNumbering.clear(); return; } 111 MachineFunction::iterator MBBI, E = end(); 112 if (MBB == 0) 113 MBBI = begin(); 114 else 115 MBBI = MBB; 116 117 // Figure out the block number this should have. 118 unsigned BlockNo = 0; 119 if (MBBI != begin()) 120 BlockNo = prior(MBBI)->getNumber()+1; 121 122 for (; MBBI != E; ++MBBI, ++BlockNo) { 123 if (MBBI->getNumber() != (int)BlockNo) { 124 // Remove use of the old number. 125 if (MBBI->getNumber() != -1) { 126 assert(MBBNumbering[MBBI->getNumber()] == &*MBBI && 127 "MBB number mismatch!"); 128 MBBNumbering[MBBI->getNumber()] = 0; 129 } 130 131 // If BlockNo is already taken, set that block's number to -1. 132 if (MBBNumbering[BlockNo]) 133 MBBNumbering[BlockNo]->setNumber(-1); 134 135 MBBNumbering[BlockNo] = MBBI; 136 MBBI->setNumber(BlockNo); 137 } 138 } 139 140 // Okay, all the blocks are renumbered. If we have compactified the block 141 // numbering, shrink MBBNumbering now. 142 assert(BlockNo <= MBBNumbering.size() && "Mismatch!"); 143 MBBNumbering.resize(BlockNo); 144} 145 146/// CreateMachineInstr - Allocate a new MachineInstr. Use this instead 147/// of `new MachineInstr'. 148/// 149MachineInstr * 150MachineFunction::CreateMachineInstr(const TargetInstrDesc &TID, 151 DebugLoc DL, bool NoImp) { 152 return new (InstructionRecycler.Allocate<MachineInstr>(Allocator)) 153 MachineInstr(TID, DL, NoImp); 154} 155 156/// CloneMachineInstr - Create a new MachineInstr which is a copy of the 157/// 'Orig' instruction, identical in all ways except the instruction 158/// has no parent, prev, or next. 159/// 160MachineInstr * 161MachineFunction::CloneMachineInstr(const MachineInstr *Orig) { 162 return new (InstructionRecycler.Allocate<MachineInstr>(Allocator)) 163 MachineInstr(*this, *Orig); 164} 165 166/// DeleteMachineInstr - Delete the given MachineInstr. 167/// 168void 169MachineFunction::DeleteMachineInstr(MachineInstr *MI) { 170 MI->~MachineInstr(); 171 InstructionRecycler.Deallocate(Allocator, MI); 172} 173 174/// CreateMachineBasicBlock - Allocate a new MachineBasicBlock. Use this 175/// instead of `new MachineBasicBlock'. 176/// 177MachineBasicBlock * 178MachineFunction::CreateMachineBasicBlock(const BasicBlock *bb) { 179 return new (BasicBlockRecycler.Allocate<MachineBasicBlock>(Allocator)) 180 MachineBasicBlock(*this, bb); 181} 182 183/// DeleteMachineBasicBlock - Delete the given MachineBasicBlock. 184/// 185void 186MachineFunction::DeleteMachineBasicBlock(MachineBasicBlock *MBB) { 187 assert(MBB->getParent() == this && "MBB parent mismatch!"); 188 MBB->~MachineBasicBlock(); 189 BasicBlockRecycler.Deallocate(Allocator, MBB); 190} 191 192MachineMemOperand * 193MachineFunction::getMachineMemOperand(const Value *v, unsigned f, 194 int64_t o, uint64_t s, 195 unsigned base_alignment) { 196 return new (Allocator) MachineMemOperand(v, f, o, s, base_alignment); 197} 198 199MachineMemOperand * 200MachineFunction::getMachineMemOperand(const MachineMemOperand *MMO, 201 int64_t Offset, uint64_t Size) { 202 return new (Allocator) 203 MachineMemOperand(MMO->getValue(), MMO->getFlags(), 204 int64_t(uint64_t(MMO->getOffset()) + 205 uint64_t(Offset)), 206 Size, MMO->getBaseAlignment()); 207} 208 209MachineInstr::mmo_iterator 210MachineFunction::allocateMemRefsArray(unsigned long Num) { 211 return Allocator.Allocate<MachineMemOperand *>(Num); 212} 213 214std::pair<MachineInstr::mmo_iterator, MachineInstr::mmo_iterator> 215MachineFunction::extractLoadMemRefs(MachineInstr::mmo_iterator Begin, 216 MachineInstr::mmo_iterator End) { 217 // Count the number of load mem refs. 218 unsigned Num = 0; 219 for (MachineInstr::mmo_iterator I = Begin; I != End; ++I) 220 if ((*I)->isLoad()) 221 ++Num; 222 223 // Allocate a new array and populate it with the load information. 224 MachineInstr::mmo_iterator Result = allocateMemRefsArray(Num); 225 unsigned Index = 0; 226 for (MachineInstr::mmo_iterator I = Begin; I != End; ++I) { 227 if ((*I)->isLoad()) { 228 if (!(*I)->isStore()) 229 // Reuse the MMO. 230 Result[Index] = *I; 231 else { 232 // Clone the MMO and unset the store flag. 233 MachineMemOperand *JustLoad = 234 getMachineMemOperand((*I)->getValue(), 235 (*I)->getFlags() & ~MachineMemOperand::MOStore, 236 (*I)->getOffset(), (*I)->getSize(), 237 (*I)->getBaseAlignment()); 238 Result[Index] = JustLoad; 239 } 240 ++Index; 241 } 242 } 243 return std::make_pair(Result, Result + Num); 244} 245 246std::pair<MachineInstr::mmo_iterator, MachineInstr::mmo_iterator> 247MachineFunction::extractStoreMemRefs(MachineInstr::mmo_iterator Begin, 248 MachineInstr::mmo_iterator End) { 249 // Count the number of load mem refs. 250 unsigned Num = 0; 251 for (MachineInstr::mmo_iterator I = Begin; I != End; ++I) 252 if ((*I)->isStore()) 253 ++Num; 254 255 // Allocate a new array and populate it with the store information. 256 MachineInstr::mmo_iterator Result = allocateMemRefsArray(Num); 257 unsigned Index = 0; 258 for (MachineInstr::mmo_iterator I = Begin; I != End; ++I) { 259 if ((*I)->isStore()) { 260 if (!(*I)->isLoad()) 261 // Reuse the MMO. 262 Result[Index] = *I; 263 else { 264 // Clone the MMO and unset the load flag. 265 MachineMemOperand *JustStore = 266 getMachineMemOperand((*I)->getValue(), 267 (*I)->getFlags() & ~MachineMemOperand::MOLoad, 268 (*I)->getOffset(), (*I)->getSize(), 269 (*I)->getBaseAlignment()); 270 Result[Index] = JustStore; 271 } 272 ++Index; 273 } 274 } 275 return std::make_pair(Result, Result + Num); 276} 277 278void MachineFunction::dump() const { 279 print(dbgs()); 280} 281 282void MachineFunction::print(raw_ostream &OS) const { 283 OS << "# Machine code for function " << Fn->getName() << ":\n"; 284 285 // Print Frame Information 286 FrameInfo->print(*this, OS); 287 288 // Print JumpTable Information 289 if (JumpTableInfo) 290 JumpTableInfo->print(OS); 291 292 // Print Constant Pool 293 ConstantPool->print(OS); 294 295 const TargetRegisterInfo *TRI = getTarget().getRegisterInfo(); 296 297 if (RegInfo && !RegInfo->livein_empty()) { 298 OS << "Function Live Ins: "; 299 for (MachineRegisterInfo::livein_iterator 300 I = RegInfo->livein_begin(), E = RegInfo->livein_end(); I != E; ++I) { 301 if (TRI) 302 OS << "%" << TRI->getName(I->first); 303 else 304 OS << " %physreg" << I->first; 305 306 if (I->second) 307 OS << " in reg%" << I->second; 308 309 if (llvm::next(I) != E) 310 OS << ", "; 311 } 312 OS << '\n'; 313 } 314 if (RegInfo && !RegInfo->liveout_empty()) { 315 OS << "Function Live Outs: "; 316 for (MachineRegisterInfo::liveout_iterator 317 I = RegInfo->liveout_begin(), E = RegInfo->liveout_end(); I != E; ++I){ 318 if (TRI) 319 OS << '%' << TRI->getName(*I); 320 else 321 OS << "%physreg" << *I; 322 323 if (llvm::next(I) != E) 324 OS << " "; 325 } 326 OS << '\n'; 327 } 328 329 for (const_iterator BB = begin(), E = end(); BB != E; ++BB) { 330 OS << '\n'; 331 BB->print(OS); 332 } 333 334 OS << "\n# End machine code for function " << Fn->getName() << ".\n\n"; 335} 336 337namespace llvm { 338 template<> 339 struct DOTGraphTraits<const MachineFunction*> : public DefaultDOTGraphTraits { 340 341 DOTGraphTraits (bool isSimple=false) : DefaultDOTGraphTraits(isSimple) {} 342 343 static std::string getGraphName(const MachineFunction *F) { 344 return "CFG for '" + F->getFunction()->getNameStr() + "' function"; 345 } 346 347 std::string getNodeLabel(const MachineBasicBlock *Node, 348 const MachineFunction *Graph) { 349 if (isSimple () && Node->getBasicBlock() && 350 !Node->getBasicBlock()->getName().empty()) 351 return Node->getBasicBlock()->getNameStr() + ":"; 352 353 std::string OutStr; 354 { 355 raw_string_ostream OSS(OutStr); 356 357 if (isSimple()) 358 OSS << Node->getNumber() << ':'; 359 else 360 Node->print(OSS); 361 } 362 363 if (OutStr[0] == '\n') OutStr.erase(OutStr.begin()); 364 365 // Process string output to make it nicer... 366 for (unsigned i = 0; i != OutStr.length(); ++i) 367 if (OutStr[i] == '\n') { // Left justify 368 OutStr[i] = '\\'; 369 OutStr.insert(OutStr.begin()+i+1, 'l'); 370 } 371 return OutStr; 372 } 373 }; 374} 375 376void MachineFunction::viewCFG() const 377{ 378#ifndef NDEBUG 379 ViewGraph(this, "mf" + getFunction()->getNameStr()); 380#else 381 errs() << "SelectionDAG::viewGraph is only available in debug builds on " 382 << "systems with Graphviz or gv!\n"; 383#endif // NDEBUG 384} 385 386void MachineFunction::viewCFGOnly() const 387{ 388#ifndef NDEBUG 389 ViewGraph(this, "mf" + getFunction()->getNameStr(), true); 390#else 391 errs() << "SelectionDAG::viewGraph is only available in debug builds on " 392 << "systems with Graphviz or gv!\n"; 393#endif // NDEBUG 394} 395 396/// addLiveIn - Add the specified physical register as a live-in value and 397/// create a corresponding virtual register for it. 398unsigned MachineFunction::addLiveIn(unsigned PReg, 399 const TargetRegisterClass *RC) { 400 assert(RC->contains(PReg) && "Not the correct regclass!"); 401 unsigned VReg = getRegInfo().createVirtualRegister(RC); 402 getRegInfo().addLiveIn(PReg, VReg); 403 return VReg; 404} 405 406/// getJTISymbol - Return the MCSymbol for the specified non-empty jump table. 407/// If isLinkerPrivate is specified, an 'l' label is returned, otherwise a 408/// normal 'L' label is returned. 409MCSymbol *MachineFunction::getJTISymbol(unsigned JTI, MCContext &Ctx, 410 bool isLinkerPrivate) const { 411 assert(JumpTableInfo && "No jump tables"); 412 413 assert(JTI < JumpTableInfo->getJumpTables().size() && "Invalid JTI!"); 414 const MCAsmInfo &MAI = *getTarget().getMCAsmInfo(); 415 416 const char *Prefix = isLinkerPrivate ? MAI.getLinkerPrivateGlobalPrefix() : 417 MAI.getPrivateGlobalPrefix(); 418 SmallString<60> Name; 419 raw_svector_ostream(Name) 420 << Prefix << "JTI" << getFunctionNumber() << '_' << JTI; 421 return Ctx.GetOrCreateSymbol(Name.str()); 422} 423 424 425//===----------------------------------------------------------------------===// 426// MachineFrameInfo implementation 427//===----------------------------------------------------------------------===// 428 429/// CreateFixedObject - Create a new object at a fixed location on the stack. 430/// All fixed objects should be created before other objects are created for 431/// efficiency. By default, fixed objects are immutable. This returns an 432/// index with a negative value. 433/// 434int MachineFrameInfo::CreateFixedObject(uint64_t Size, int64_t SPOffset, 435 bool Immutable, bool isSS) { 436 assert(Size != 0 && "Cannot allocate zero size fixed stack objects!"); 437 Objects.insert(Objects.begin(), StackObject(Size, 1, SPOffset, Immutable, 438 isSS)); 439 return -++NumFixedObjects; 440} 441 442 443BitVector 444MachineFrameInfo::getPristineRegs(const MachineBasicBlock *MBB) const { 445 assert(MBB && "MBB must be valid"); 446 const MachineFunction *MF = MBB->getParent(); 447 assert(MF && "MBB must be part of a MachineFunction"); 448 const TargetMachine &TM = MF->getTarget(); 449 const TargetRegisterInfo *TRI = TM.getRegisterInfo(); 450 BitVector BV(TRI->getNumRegs()); 451 452 // Before CSI is calculated, no registers are considered pristine. They can be 453 // freely used and PEI will make sure they are saved. 454 if (!isCalleeSavedInfoValid()) 455 return BV; 456 457 for (const unsigned *CSR = TRI->getCalleeSavedRegs(MF); CSR && *CSR; ++CSR) 458 BV.set(*CSR); 459 460 // The entry MBB always has all CSRs pristine. 461 if (MBB == &MF->front()) 462 return BV; 463 464 // On other MBBs the saved CSRs are not pristine. 465 const std::vector<CalleeSavedInfo> &CSI = getCalleeSavedInfo(); 466 for (std::vector<CalleeSavedInfo>::const_iterator I = CSI.begin(), 467 E = CSI.end(); I != E; ++I) 468 BV.reset(I->getReg()); 469 470 return BV; 471} 472 473 474void MachineFrameInfo::print(const MachineFunction &MF, raw_ostream &OS) const{ 475 if (Objects.empty()) return; 476 477 const TargetFrameInfo *FI = MF.getTarget().getFrameInfo(); 478 int ValOffset = (FI ? FI->getOffsetOfLocalArea() : 0); 479 480 OS << "Frame Objects:\n"; 481 482 for (unsigned i = 0, e = Objects.size(); i != e; ++i) { 483 const StackObject &SO = Objects[i]; 484 OS << " fi#" << (int)(i-NumFixedObjects) << ": "; 485 if (SO.Size == ~0ULL) { 486 OS << "dead\n"; 487 continue; 488 } 489 if (SO.Size == 0) 490 OS << "variable sized"; 491 else 492 OS << "size=" << SO.Size; 493 OS << ", align=" << SO.Alignment; 494 495 if (i < NumFixedObjects) 496 OS << ", fixed"; 497 if (i < NumFixedObjects || SO.SPOffset != -1) { 498 int64_t Off = SO.SPOffset - ValOffset; 499 OS << ", at location [SP"; 500 if (Off > 0) 501 OS << "+" << Off; 502 else if (Off < 0) 503 OS << Off; 504 OS << "]"; 505 } 506 OS << "\n"; 507 } 508} 509 510void MachineFrameInfo::dump(const MachineFunction &MF) const { 511 print(MF, dbgs()); 512} 513 514//===----------------------------------------------------------------------===// 515// MachineJumpTableInfo implementation 516//===----------------------------------------------------------------------===// 517 518/// getEntrySize - Return the size of each entry in the jump table. 519unsigned MachineJumpTableInfo::getEntrySize(const TargetData &TD) const { 520 // The size of a jump table entry is 4 bytes unless the entry is just the 521 // address of a block, in which case it is the pointer size. 522 switch (getEntryKind()) { 523 case MachineJumpTableInfo::EK_BlockAddress: 524 return TD.getPointerSize(); 525 case MachineJumpTableInfo::EK_GPRel32BlockAddress: 526 case MachineJumpTableInfo::EK_LabelDifference32: 527 case MachineJumpTableInfo::EK_Custom32: 528 return 4; 529 case MachineJumpTableInfo::EK_Inline: 530 return 0; 531 } 532 assert(0 && "Unknown jump table encoding!"); 533 return ~0; 534} 535 536/// getEntryAlignment - Return the alignment of each entry in the jump table. 537unsigned MachineJumpTableInfo::getEntryAlignment(const TargetData &TD) const { 538 // The alignment of a jump table entry is the alignment of int32 unless the 539 // entry is just the address of a block, in which case it is the pointer 540 // alignment. 541 switch (getEntryKind()) { 542 case MachineJumpTableInfo::EK_BlockAddress: 543 return TD.getPointerABIAlignment(); 544 case MachineJumpTableInfo::EK_GPRel32BlockAddress: 545 case MachineJumpTableInfo::EK_LabelDifference32: 546 case MachineJumpTableInfo::EK_Custom32: 547 return TD.getABIIntegerTypeAlignment(32); 548 case MachineJumpTableInfo::EK_Inline: 549 return 1; 550 } 551 assert(0 && "Unknown jump table encoding!"); 552 return ~0; 553} 554 555/// createJumpTableIndex - Create a new jump table entry in the jump table info. 556/// 557unsigned MachineJumpTableInfo::createJumpTableIndex( 558 const std::vector<MachineBasicBlock*> &DestBBs) { 559 assert(!DestBBs.empty() && "Cannot create an empty jump table!"); 560 JumpTables.push_back(MachineJumpTableEntry(DestBBs)); 561 return JumpTables.size()-1; 562} 563 564/// ReplaceMBBInJumpTables - If Old is the target of any jump tables, update 565/// the jump tables to branch to New instead. 566bool MachineJumpTableInfo::ReplaceMBBInJumpTables(MachineBasicBlock *Old, 567 MachineBasicBlock *New) { 568 assert(Old != New && "Not making a change?"); 569 bool MadeChange = false; 570 for (size_t i = 0, e = JumpTables.size(); i != e; ++i) 571 ReplaceMBBInJumpTable(i, Old, New); 572 return MadeChange; 573} 574 575/// ReplaceMBBInJumpTable - If Old is a target of the jump tables, update 576/// the jump table to branch to New instead. 577bool MachineJumpTableInfo::ReplaceMBBInJumpTable(unsigned Idx, 578 MachineBasicBlock *Old, 579 MachineBasicBlock *New) { 580 assert(Old != New && "Not making a change?"); 581 bool MadeChange = false; 582 MachineJumpTableEntry &JTE = JumpTables[Idx]; 583 for (size_t j = 0, e = JTE.MBBs.size(); j != e; ++j) 584 if (JTE.MBBs[j] == Old) { 585 JTE.MBBs[j] = New; 586 MadeChange = true; 587 } 588 return MadeChange; 589} 590 591void MachineJumpTableInfo::print(raw_ostream &OS) const { 592 if (JumpTables.empty()) return; 593 594 OS << "Jump Tables:\n"; 595 596 for (unsigned i = 0, e = JumpTables.size(); i != e; ++i) { 597 OS << " jt#" << i << ": "; 598 for (unsigned j = 0, f = JumpTables[i].MBBs.size(); j != f; ++j) 599 OS << " BB#" << JumpTables[i].MBBs[j]->getNumber(); 600 } 601 602 OS << '\n'; 603} 604 605void MachineJumpTableInfo::dump() const { print(dbgs()); } 606 607 608//===----------------------------------------------------------------------===// 609// MachineConstantPool implementation 610//===----------------------------------------------------------------------===// 611 612const Type *MachineConstantPoolEntry::getType() const { 613 if (isMachineConstantPoolEntry()) 614 return Val.MachineCPVal->getType(); 615 return Val.ConstVal->getType(); 616} 617 618 619unsigned MachineConstantPoolEntry::getRelocationInfo() const { 620 if (isMachineConstantPoolEntry()) 621 return Val.MachineCPVal->getRelocationInfo(); 622 return Val.ConstVal->getRelocationInfo(); 623} 624 625MachineConstantPool::~MachineConstantPool() { 626 for (unsigned i = 0, e = Constants.size(); i != e; ++i) 627 if (Constants[i].isMachineConstantPoolEntry()) 628 delete Constants[i].Val.MachineCPVal; 629} 630 631/// CanShareConstantPoolEntry - Test whether the given two constants 632/// can be allocated the same constant pool entry. 633static bool CanShareConstantPoolEntry(Constant *A, Constant *B, 634 const TargetData *TD) { 635 // Handle the trivial case quickly. 636 if (A == B) return true; 637 638 // If they have the same type but weren't the same constant, quickly 639 // reject them. 640 if (A->getType() == B->getType()) return false; 641 642 // For now, only support constants with the same size. 643 if (TD->getTypeStoreSize(A->getType()) != TD->getTypeStoreSize(B->getType())) 644 return false; 645 646 // If a floating-point value and an integer value have the same encoding, 647 // they can share a constant-pool entry. 648 if (ConstantFP *AFP = dyn_cast<ConstantFP>(A)) 649 if (ConstantInt *BI = dyn_cast<ConstantInt>(B)) 650 return AFP->getValueAPF().bitcastToAPInt() == BI->getValue(); 651 if (ConstantFP *BFP = dyn_cast<ConstantFP>(B)) 652 if (ConstantInt *AI = dyn_cast<ConstantInt>(A)) 653 return BFP->getValueAPF().bitcastToAPInt() == AI->getValue(); 654 655 // Two vectors can share an entry if each pair of corresponding 656 // elements could. 657 if (ConstantVector *AV = dyn_cast<ConstantVector>(A)) 658 if (ConstantVector *BV = dyn_cast<ConstantVector>(B)) { 659 if (AV->getType()->getNumElements() != BV->getType()->getNumElements()) 660 return false; 661 for (unsigned i = 0, e = AV->getType()->getNumElements(); i != e; ++i) 662 if (!CanShareConstantPoolEntry(AV->getOperand(i), 663 BV->getOperand(i), TD)) 664 return false; 665 return true; 666 } 667 668 // TODO: Handle other cases. 669 670 return false; 671} 672 673/// getConstantPoolIndex - Create a new entry in the constant pool or return 674/// an existing one. User must specify the log2 of the minimum required 675/// alignment for the object. 676/// 677unsigned MachineConstantPool::getConstantPoolIndex(Constant *C, 678 unsigned Alignment) { 679 assert(Alignment && "Alignment must be specified!"); 680 if (Alignment > PoolAlignment) PoolAlignment = Alignment; 681 682 // Check to see if we already have this constant. 683 // 684 // FIXME, this could be made much more efficient for large constant pools. 685 for (unsigned i = 0, e = Constants.size(); i != e; ++i) 686 if (!Constants[i].isMachineConstantPoolEntry() && 687 CanShareConstantPoolEntry(Constants[i].Val.ConstVal, C, TD)) { 688 if ((unsigned)Constants[i].getAlignment() < Alignment) 689 Constants[i].Alignment = Alignment; 690 return i; 691 } 692 693 Constants.push_back(MachineConstantPoolEntry(C, Alignment)); 694 return Constants.size()-1; 695} 696 697unsigned MachineConstantPool::getConstantPoolIndex(MachineConstantPoolValue *V, 698 unsigned Alignment) { 699 assert(Alignment && "Alignment must be specified!"); 700 if (Alignment > PoolAlignment) PoolAlignment = Alignment; 701 702 // Check to see if we already have this constant. 703 // 704 // FIXME, this could be made much more efficient for large constant pools. 705 int Idx = V->getExistingMachineCPValue(this, Alignment); 706 if (Idx != -1) 707 return (unsigned)Idx; 708 709 Constants.push_back(MachineConstantPoolEntry(V, Alignment)); 710 return Constants.size()-1; 711} 712 713void MachineConstantPool::print(raw_ostream &OS) const { 714 if (Constants.empty()) return; 715 716 OS << "Constant Pool:\n"; 717 for (unsigned i = 0, e = Constants.size(); i != e; ++i) { 718 OS << " cp#" << i << ": "; 719 if (Constants[i].isMachineConstantPoolEntry()) 720 Constants[i].Val.MachineCPVal->print(OS); 721 else 722 OS << *(Value*)Constants[i].Val.ConstVal; 723 OS << ", align=" << Constants[i].getAlignment(); 724 OS << "\n"; 725 } 726} 727 728void MachineConstantPool::dump() const { print(dbgs()); } 729