lib/CodeGen/MachineFunction.cpp

   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/TargetFrameLowering.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"
  41 using namespace llvm;
  42
  43 //===----------------------------------------------------------------------===//
  44 // MachineFunction implementation
  45 //===----------------------------------------------------------------------===//
  46
  47 // Out of line virtual method.
  48 MachineFunctionInfo::~MachineFunctionInfo() {}
  49
  50 void ilist_traits<MachineBasicBlock>::deleteNode(MachineBasicBlock *MBB) {
  51   MBB->getParent()->DeleteMachineBasicBlock(MBB);
  52 }
  53
  54 MachineFunction::MachineFunction(const Function *F, const TargetMachine &TM,
  55                                  unsigned FunctionNum, MachineModuleInfo &mmi,
  56                                  GCModuleInfo* gmi)
  57   : Fn(F), Target(TM), Ctx(mmi.getContext()), MMI(mmi), GMI(gmi) {
  58   if (TM.getRegisterInfo())
  59     RegInfo = new (Allocator) MachineRegisterInfo(*TM.getRegisterInfo());
  60   else
  61     RegInfo = 0;
  62   MFInfo = 0;
  63   FrameInfo = new (Allocator) MachineFrameInfo(*TM.getFrameLowering());
  64   if (Fn->hasFnAttr(Attribute::StackAlignment))
  65     FrameInfo->setMaxAlignment(Attribute::getStackAlignmentFromAttrs(
  66         Fn->getAttributes().getFnAttributes()));
  67   ConstantPool = new (Allocator) MachineConstantPool(TM.getTargetData());
  68   Alignment = TM.getTargetLowering()->getMinFunctionAlignment();
  69   // FIXME: Shouldn't use pref alignment if explicit alignment is set on Fn.
  70   if (!Fn->hasFnAttr(Attribute::OptimizeForSize))
  71     Alignment = std::max(Alignment,
  72                          TM.getTargetLowering()->getPrefFunctionAlignment());
  73   FunctionNumber = FunctionNum;
  74   JumpTableInfo = 0;
  75 }
  76
  77 MachineFunction::~MachineFunction() {
  78   BasicBlocks.clear();
  79   InstructionRecycler.clear(Allocator);
  80   BasicBlockRecycler.clear(Allocator);
  81   if (RegInfo) {
  82     RegInfo->~MachineRegisterInfo();
  83     Allocator.Deallocate(RegInfo);
  84   }
  85   if (MFInfo) {
  86     MFInfo->~MachineFunctionInfo();
  87     Allocator.Deallocate(MFInfo);
  88   }
  89   FrameInfo->~MachineFrameInfo();         Allocator.Deallocate(FrameInfo);
  90   ConstantPool->~MachineConstantPool();   Allocator.Deallocate(ConstantPool);
  91
  92   if (JumpTableInfo) {
  93     JumpTableInfo->~MachineJumpTableInfo();
  94     Allocator.Deallocate(JumpTableInfo);
  95   }
  96 }
  97
  98 /// getOrCreateJumpTableInfo - Get the JumpTableInfo for this function, if it
  99 /// does already exist, allocate one.
 100 MachineJumpTableInfo *MachineFunction::
 101 getOrCreateJumpTableInfo(unsigned EntryKind) {
 102   if (JumpTableInfo) return JumpTableInfo;
 103
 104   JumpTableInfo = new (Allocator)
 105     MachineJumpTableInfo((MachineJumpTableInfo::JTEntryKind)EntryKind);
 106   return JumpTableInfo;
 107 }
 108
 109 /// RenumberBlocks - This discards all of the MachineBasicBlock numbers and
 110 /// recomputes them.  This guarantees that the MBB numbers are sequential,
 111 /// dense, and match the ordering of the blocks within the function.  If a
 112 /// specific MachineBasicBlock is specified, only that block and those after
 113 /// it are renumbered.
 114 void MachineFunction::RenumberBlocks(MachineBasicBlock *MBB) {
 115   if (empty()) { MBBNumbering.clear(); return; }
 116   MachineFunction::iterator MBBI, E = end();
 117   if (MBB == 0)
 118     MBBI = begin();
 119   else
 120     MBBI = MBB;
 121
 122   // Figure out the block number this should have.
 123   unsigned BlockNo = 0;
 124   if (MBBI != begin())
 125     BlockNo = prior(MBBI)->getNumber()+1;
 126
 127   for (; MBBI != E; ++MBBI, ++BlockNo) {
 128     if (MBBI->getNumber() != (int)BlockNo) {
 129       // Remove use of the old number.
 130       if (MBBI->getNumber() != -1) {
 131         assert(MBBNumbering[MBBI->getNumber()] == &*MBBI &&
 132                "MBB number mismatch!");
 133         MBBNumbering[MBBI->getNumber()] = 0;
 134       }
 135
 136       // If BlockNo is already taken, set that block's number to -1.
 137       if (MBBNumbering[BlockNo])
 138         MBBNumbering[BlockNo]->setNumber(-1);
 139
 140       MBBNumbering[BlockNo] = MBBI;
 141       MBBI->setNumber(BlockNo);
 142     }
 143   }
 144
 145   // Okay, all the blocks are renumbered.  If we have compactified the block
 146   // numbering, shrink MBBNumbering now.
 147   assert(BlockNo <= MBBNumbering.size() && "Mismatch!");
 148   MBBNumbering.resize(BlockNo);
 149 }
 150
 151 /// CreateMachineInstr - Allocate a new MachineInstr. Use this instead
 152 /// of `new MachineInstr'.
 153 ///
 154 MachineInstr *
 155 MachineFunction::CreateMachineInstr(const MCInstrDesc &MCID,
 156                                     DebugLoc DL, bool NoImp) {
 157   return new (InstructionRecycler.Allocate<MachineInstr>(Allocator))
 158     MachineInstr(MCID, DL, NoImp);
 159 }
 160
 161 /// CloneMachineInstr - Create a new MachineInstr which is a copy of the
 162 /// 'Orig' instruction, identical in all ways except the instruction
 163 /// has no parent, prev, or next.
 164 ///
 165 MachineInstr *
 166 MachineFunction::CloneMachineInstr(const MachineInstr *Orig) {
 167   return new (InstructionRecycler.Allocate<MachineInstr>(Allocator))
 168              MachineInstr(*this, *Orig);
 169 }
 170
 171 /// DeleteMachineInstr - Delete the given MachineInstr.
 172 ///
 173 void
 174 MachineFunction::DeleteMachineInstr(MachineInstr *MI) {
 175   MI->~MachineInstr();
 176   InstructionRecycler.Deallocate(Allocator, MI);
 177 }
 178
 179 /// CreateMachineBasicBlock - Allocate a new MachineBasicBlock. Use this
 180 /// instead of `new MachineBasicBlock'.
 181 ///
 182 MachineBasicBlock *
 183 MachineFunction::CreateMachineBasicBlock(const BasicBlock *bb) {
 184   return new (BasicBlockRecycler.Allocate<MachineBasicBlock>(Allocator))
 185              MachineBasicBlock(*this, bb);
 186 }
 187
 188 /// DeleteMachineBasicBlock - Delete the given MachineBasicBlock.
 189 ///
 190 void
 191 MachineFunction::DeleteMachineBasicBlock(MachineBasicBlock *MBB) {
 192   assert(MBB->getParent() == this && "MBB parent mismatch!");
 193   MBB->~MachineBasicBlock();
 194   BasicBlockRecycler.Deallocate(Allocator, MBB);
 195 }
 196
 197 MachineMemOperand *
 198 MachineFunction::getMachineMemOperand(MachinePointerInfo PtrInfo, unsigned f,
 199                                       uint64_t s, unsigned base_alignment,
 200                                       const MDNode *TBAAInfo) {
 201   return new (Allocator) MachineMemOperand(PtrInfo, f, s, base_alignment,
 202                                            TBAAInfo);
 203 }
 204
 205 MachineMemOperand *
 206 MachineFunction::getMachineMemOperand(const MachineMemOperand *MMO,
 207                                       int64_t Offset, uint64_t Size) {
 208   return new (Allocator)
 209              MachineMemOperand(MachinePointerInfo(MMO->getValue(),
 210                                                   MMO->getOffset()+Offset),
 211                                MMO->getFlags(), Size,
 212                                MMO->getBaseAlignment(), 0);
 213 }
 214
 215 MachineInstr::mmo_iterator
 216 MachineFunction::allocateMemRefsArray(unsigned long Num) {
 217   return Allocator.Allocate<MachineMemOperand *>(Num);
 218 }
 219
 220 std::pair<MachineInstr::mmo_iterator, MachineInstr::mmo_iterator>
 221 MachineFunction::extractLoadMemRefs(MachineInstr::mmo_iterator Begin,
 222                                     MachineInstr::mmo_iterator End) {
 223   // Count the number of load mem refs.
 224   unsigned Num = 0;
 225   for (MachineInstr::mmo_iterator I = Begin; I != End; ++I)
 226     if ((*I)->isLoad())
 227       ++Num;
 228
 229   // Allocate a new array and populate it with the load information.
 230   MachineInstr::mmo_iterator Result = allocateMemRefsArray(Num);
 231   unsigned Index = 0;
 232   for (MachineInstr::mmo_iterator I = Begin; I != End; ++I) {
 233     if ((*I)->isLoad()) {
 234       if (!(*I)->isStore())
 235         // Reuse the MMO.
 236         Result[Index] = *I;
 237       else {
 238         // Clone the MMO and unset the store flag.
 239         MachineMemOperand *JustLoad =
 240           getMachineMemOperand((*I)->getPointerInfo(),
 241                                (*I)->getFlags() & ~MachineMemOperand::MOStore,
 242                                (*I)->getSize(), (*I)->getBaseAlignment(),
 243                                (*I)->getTBAAInfo());
 244         Result[Index] = JustLoad;
 245       }
 246       ++Index;
 247     }
 248   }
 249   return std::make_pair(Result, Result + Num);
 250 }
 251
 252 std::pair<MachineInstr::mmo_iterator, MachineInstr::mmo_iterator>
 253 MachineFunction::extractStoreMemRefs(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)->isStore())
 259       ++Num;
 260
 261   // Allocate a new array and populate it with the store 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)->isStore()) {
 266       if (!(*I)->isLoad())
 267         // Reuse the MMO.
 268         Result[Index] = *I;
 269       else {
 270         // Clone the MMO and unset the load flag.
 271         MachineMemOperand *JustStore =
 272           getMachineMemOperand((*I)->getPointerInfo(),
 273                                (*I)->getFlags() & ~MachineMemOperand::MOLoad,
 274                                (*I)->getSize(), (*I)->getBaseAlignment(),
 275                                (*I)->getTBAAInfo());
 276         Result[Index] = JustStore;
 277       }
 278       ++Index;
 279     }
 280   }
 281   return std::make_pair(Result, Result + Num);
 282 }
 283
 284 void MachineFunction::dump() const {
 285   print(dbgs());
 286 }
 287
 288 void MachineFunction::print(raw_ostream &OS, SlotIndexes *Indexes) const {
 289   OS << "# Machine code for function " << Fn->getName() << ":\n";
 290
 291   // Print Frame Information
 292   FrameInfo->print(*this, OS);
 293
 294   // Print JumpTable Information
 295   if (JumpTableInfo)
 296     JumpTableInfo->print(OS);
 297
 298   // Print Constant Pool
 299   ConstantPool->print(OS);
 300
 301   const TargetRegisterInfo *TRI = getTarget().getRegisterInfo();
 302
 303   if (RegInfo && !RegInfo->livein_empty()) {
 304     OS << "Function Live Ins: ";
 305     for (MachineRegisterInfo::livein_iterator
 306          I = RegInfo->livein_begin(), E = RegInfo->livein_end(); I != E; ++I) {
 307       OS << PrintReg(I->first, TRI);
 308       if (I->second)
 309         OS << " in " << PrintReg(I->second, TRI);
 310       if (llvm::next(I) != E)
 311         OS << ", ";
 312     }
 313     OS << '\n';
 314   }
 315   if (RegInfo && !RegInfo->liveout_empty()) {
 316     OS << "Function Live Outs:";
 317     for (MachineRegisterInfo::liveout_iterator
 318          I = RegInfo->liveout_begin(), E = RegInfo->liveout_end(); I != E; ++I)
 319       OS << ' ' << PrintReg(*I, TRI);
 320     OS << '\n';
 321   }
 322
 323   for (const_iterator BB = begin(), E = end(); BB != E; ++BB) {
 324     OS << '\n';
 325     BB->print(OS, Indexes);
 326   }
 327
 328   OS << "\n# End machine code for function " << Fn->getName() << ".\n\n";
 329 }
 330
 331 namespace llvm {
 332   template<>
 333   struct DOTGraphTraits<const MachineFunction*> : public DefaultDOTGraphTraits {
 334
 335   DOTGraphTraits (bool isSimple=false) : DefaultDOTGraphTraits(isSimple) {}
 336
 337     static std::string getGraphName(const MachineFunction *F) {
 338       return "CFG for '" + F->getFunction()->getNameStr() + "' function";
 339     }
 340
 341     std::string getNodeLabel(const MachineBasicBlock *Node,
 342                              const MachineFunction *Graph) {
 343       std::string OutStr;
 344       {
 345         raw_string_ostream OSS(OutStr);
 346
 347         if (isSimple()) {
 348           OSS << "BB#" << Node->getNumber();
 349           if (const BasicBlock *BB = Node->getBasicBlock())
 350             OSS << ": " << BB->getName();
 351         } else
 352           Node->print(OSS);
 353       }
 354
 355       if (OutStr[0] == '\n') OutStr.erase(OutStr.begin());
 356
 357       // Process string output to make it nicer...
 358       for (unsigned i = 0; i != OutStr.length(); ++i)
 359         if (OutStr[i] == '\n') {                            // Left justify
 360           OutStr[i] = '\\';
 361           OutStr.insert(OutStr.begin()+i+1, 'l');
 362         }
 363       return OutStr;
 364     }
 365   };
 366 }
 367
 368 void MachineFunction::viewCFG() const
 369 {
 370 #ifndef NDEBUG
 371   ViewGraph(this, "mf" + getFunction()->getNameStr());
 372 #else
 373   errs() << "MachineFunction::viewCFG is only available in debug builds on "
 374          << "systems with Graphviz or gv!\n";
 375 #endif // NDEBUG
 376 }
 377
 378 void MachineFunction::viewCFGOnly() const
 379 {
 380 #ifndef NDEBUG
 381   ViewGraph(this, "mf" + getFunction()->getNameStr(), true);
 382 #else
 383   errs() << "MachineFunction::viewCFGOnly is only available in debug builds on "
 384          << "systems with Graphviz or gv!\n";
 385 #endif // NDEBUG
 386 }
 387
 388 /// addLiveIn - Add the specified physical register as a live-in value and
 389 /// create a corresponding virtual register for it.
 390 unsigned MachineFunction::addLiveIn(unsigned PReg,
 391                                     const TargetRegisterClass *RC) {
 392   MachineRegisterInfo &MRI = getRegInfo();
 393   unsigned VReg = MRI.getLiveInVirtReg(PReg);
 394   if (VReg) {
 395     assert(MRI.getRegClass(VReg) == RC && "Register class mismatch!");
 396     return VReg;
 397   }
 398   VReg = MRI.createVirtualRegister(RC);
 399   MRI.addLiveIn(PReg, VReg);
 400   return VReg;
 401 }
 402
 403 /// getJTISymbol - Return the MCSymbol for the specified non-empty jump table.
 404 /// If isLinkerPrivate is specified, an 'l' label is returned, otherwise a
 405 /// normal 'L' label is returned.
 406 MCSymbol *MachineFunction::getJTISymbol(unsigned JTI, MCContext &Ctx,
 407                                         bool isLinkerPrivate) const {
 408   assert(JumpTableInfo && "No jump tables");
 409
 410   assert(JTI < JumpTableInfo->getJumpTables().size() && "Invalid JTI!");
 411   const MCAsmInfo &MAI = *getTarget().getMCAsmInfo();
 412
 413   const char *Prefix = isLinkerPrivate ? MAI.getLinkerPrivateGlobalPrefix() :
 414                                          MAI.getPrivateGlobalPrefix();
 415   SmallString<60> Name;
 416   raw_svector_ostream(Name)
 417     << Prefix << "JTI" << getFunctionNumber() << '_' << JTI;
 418   return Ctx.GetOrCreateSymbol(Name.str());
 419 }
 420
 421 /// getPICBaseSymbol - Return a function-local symbol to represent the PIC
 422 /// base.
 423 MCSymbol *MachineFunction::getPICBaseSymbol() const {
 424   const MCAsmInfo &MAI = *Target.getMCAsmInfo();
 425   return Ctx.GetOrCreateSymbol(Twine(MAI.getPrivateGlobalPrefix())+
 426                                Twine(getFunctionNumber())+"$pb");
 427 }
 428
 429 //===----------------------------------------------------------------------===//
 430 //  MachineFrameInfo implementation
 431 //===----------------------------------------------------------------------===//
 432
 433 /// CreateFixedObject - Create a new object at a fixed location on the stack.
 434 /// All fixed objects should be created before other objects are created for
 435 /// efficiency. By default, fixed objects are immutable. This returns an
 436 /// index with a negative value.
 437 ///
 438 int MachineFrameInfo::CreateFixedObject(uint64_t Size, int64_t SPOffset,
 439                                         bool Immutable) {
 440   assert(Size != 0 && "Cannot allocate zero size fixed stack objects!");
 441   // The alignment of the frame index can be determined from its offset from
 442   // the incoming frame position.  If the frame object is at offset 32 and
 443   // the stack is guaranteed to be 16-byte aligned, then we know that the
 444   // object is 16-byte aligned.
 445   unsigned StackAlign = TFI.getStackAlignment();
 446   unsigned Align = MinAlign(SPOffset, StackAlign);
 447   Objects.insert(Objects.begin(), StackObject(Size, Align, SPOffset, Immutable,
 448                                               /*isSS*/false, false));
 449   return -++NumFixedObjects;
 450 }
 451
 452
 453 BitVector
 454 MachineFrameInfo::getPristineRegs(const MachineBasicBlock *MBB) const {
 455   assert(MBB && "MBB must be valid");
 456   const MachineFunction *MF = MBB->getParent();
 457   assert(MF && "MBB must be part of a MachineFunction");
 458   const TargetMachine &TM = MF->getTarget();
 459   const TargetRegisterInfo *TRI = TM.getRegisterInfo();
 460   BitVector BV(TRI->getNumRegs());
 461
 462   // Before CSI is calculated, no registers are considered pristine. They can be
 463   // freely used and PEI will make sure they are saved.
 464   if (!isCalleeSavedInfoValid())
 465     return BV;
 466
 467   for (const unsigned *CSR = TRI->getCalleeSavedRegs(MF); CSR && *CSR; ++CSR)
 468     BV.set(*CSR);
 469
 470   // The entry MBB always has all CSRs pristine.
 471   if (MBB == &MF->front())
 472     return BV;
 473
 474   // On other MBBs the saved CSRs are not pristine.
 475   const std::vector<CalleeSavedInfo> &CSI = getCalleeSavedInfo();
 476   for (std::vector<CalleeSavedInfo>::const_iterator I = CSI.begin(),
 477          E = CSI.end(); I != E; ++I)
 478     BV.reset(I->getReg());
 479
 480   return BV;
 481 }
 482
 483
 484 void MachineFrameInfo::print(const MachineFunction &MF, raw_ostream &OS) const{
 485   if (Objects.empty()) return;
 486
 487   const TargetFrameLowering *FI = MF.getTarget().getFrameLowering();
 488   int ValOffset = (FI ? FI->getOffsetOfLocalArea() : 0);
 489
 490   OS << "Frame Objects:\n";
 491
 492   for (unsigned i = 0, e = Objects.size(); i != e; ++i) {
 493     const StackObject &SO = Objects[i];
 494     OS << "  fi#" << (int)(i-NumFixedObjects) << ": ";
 495     if (SO.Size == ~0ULL) {
 496       OS << "dead\n";
 497       continue;
 498     }
 499     if (SO.Size == 0)
 500       OS << "variable sized";
 501     else
 502       OS << "size=" << SO.Size;
 503     OS << ", align=" << SO.Alignment;
 504
 505     if (i < NumFixedObjects)
 506       OS << ", fixed";
 507     if (i < NumFixedObjects || SO.SPOffset != -1) {
 508       int64_t Off = SO.SPOffset - ValOffset;
 509       OS << ", at location [SP";
 510       if (Off > 0)
 511         OS << "+" << Off;
 512       else if (Off < 0)
 513         OS << Off;
 514       OS << "]";
 515     }
 516     OS << "\n";
 517   }
 518 }
 519
 520 void MachineFrameInfo::dump(const MachineFunction &MF) const {
 521   print(MF, dbgs());
 522 }
 523
 524 //===----------------------------------------------------------------------===//
 525 //  MachineJumpTableInfo implementation
 526 //===----------------------------------------------------------------------===//
 527
 528 /// getEntrySize - Return the size of each entry in the jump table.
 529 unsigned MachineJumpTableInfo::getEntrySize(const TargetData &TD) const {
 530   // The size of a jump table entry is 4 bytes unless the entry is just the
 531   // address of a block, in which case it is the pointer size.
 532   switch (getEntryKind()) {
 533   case MachineJumpTableInfo::EK_BlockAddress:
 534     return TD.getPointerSize();
 535   case MachineJumpTableInfo::EK_GPRel32BlockAddress:
 536   case MachineJumpTableInfo::EK_LabelDifference32:
 537   case MachineJumpTableInfo::EK_Custom32:
 538     return 4;
 539   case MachineJumpTableInfo::EK_Inline:
 540     return 0;
 541   }
 542   assert(0 && "Unknown jump table encoding!");
 543   return ~0;
 544 }
 545
 546 /// getEntryAlignment - Return the alignment of each entry in the jump table.
 547 unsigned MachineJumpTableInfo::getEntryAlignment(const TargetData &TD) const {
 548   // The alignment of a jump table entry is the alignment of int32 unless the
 549   // entry is just the address of a block, in which case it is the pointer
 550   // alignment.
 551   switch (getEntryKind()) {
 552   case MachineJumpTableInfo::EK_BlockAddress:
 553     return TD.getPointerABIAlignment();
 554   case MachineJumpTableInfo::EK_GPRel32BlockAddress:
 555   case MachineJumpTableInfo::EK_LabelDifference32:
 556   case MachineJumpTableInfo::EK_Custom32:
 557     return TD.getABIIntegerTypeAlignment(32);
 558   case MachineJumpTableInfo::EK_Inline:
 559     return 1;
 560   }
 561   assert(0 && "Unknown jump table encoding!");
 562   return ~0;
 563 }
 564
 565 /// createJumpTableIndex - Create a new jump table entry in the jump table info.
 566 ///
 567 unsigned MachineJumpTableInfo::createJumpTableIndex(
 568                                const std::vector<MachineBasicBlock*> &DestBBs) {
 569   assert(!DestBBs.empty() && "Cannot create an empty jump table!");
 570   JumpTables.push_back(MachineJumpTableEntry(DestBBs));
 571   return JumpTables.size()-1;
 572 }
 573
 574 /// ReplaceMBBInJumpTables - If Old is the target of any jump tables, update
 575 /// the jump tables to branch to New instead.
 576 bool MachineJumpTableInfo::ReplaceMBBInJumpTables(MachineBasicBlock *Old,
 577                                                   MachineBasicBlock *New) {
 578   assert(Old != New && "Not making a change?");
 579   bool MadeChange = false;
 580   for (size_t i = 0, e = JumpTables.size(); i != e; ++i)
 581     ReplaceMBBInJumpTable(i, Old, New);
 582   return MadeChange;
 583 }
 584
 585 /// ReplaceMBBInJumpTable - If Old is a target of the jump tables, update
 586 /// the jump table to branch to New instead.
 587 bool MachineJumpTableInfo::ReplaceMBBInJumpTable(unsigned Idx,
 588                                                  MachineBasicBlock *Old,
 589                                                  MachineBasicBlock *New) {
 590   assert(Old != New && "Not making a change?");
 591   bool MadeChange = false;
 592   MachineJumpTableEntry &JTE = JumpTables[Idx];
 593   for (size_t j = 0, e = JTE.MBBs.size(); j != e; ++j)
 594     if (JTE.MBBs[j] == Old) {
 595       JTE.MBBs[j] = New;
 596       MadeChange = true;
 597     }
 598   return MadeChange;
 599 }
 600
 601 void MachineJumpTableInfo::print(raw_ostream &OS) const {
 602   if (JumpTables.empty()) return;
 603
 604   OS << "Jump Tables:\n";
 605
 606   for (unsigned i = 0, e = JumpTables.size(); i != e; ++i) {
 607     OS << "  jt#" << i << ": ";
 608     for (unsigned j = 0, f = JumpTables[i].MBBs.size(); j != f; ++j)
 609       OS << " BB#" << JumpTables[i].MBBs[j]->getNumber();
 610   }
 611
 612   OS << '\n';
 613 }
 614
 615 void MachineJumpTableInfo::dump() const { print(dbgs()); }
 616
 617
 618 //===----------------------------------------------------------------------===//
 619 //  MachineConstantPool implementation
 620 //===----------------------------------------------------------------------===//
 621
 622 const Type *MachineConstantPoolEntry::getType() const {
 623   if (isMachineConstantPoolEntry())
 624     return Val.MachineCPVal->getType();
 625   return Val.ConstVal->getType();
 626 }
 627
 628
 629 unsigned MachineConstantPoolEntry::getRelocationInfo() const {
 630   if (isMachineConstantPoolEntry())
 631     return Val.MachineCPVal->getRelocationInfo();
 632   return Val.ConstVal->getRelocationInfo();
 633 }
 634
 635 MachineConstantPool::~MachineConstantPool() {
 636   for (unsigned i = 0, e = Constants.size(); i != e; ++i)
 637     if (Constants[i].isMachineConstantPoolEntry())
 638       delete Constants[i].Val.MachineCPVal;
 639   for (DenseSet<MachineConstantPoolValue*>::iterator I =
 640        MachineCPVsSharingEntries.begin(), E = MachineCPVsSharingEntries.end();
 641        I != E; ++I)
 642     delete *I;
 643 }
 644
 645 /// CanShareConstantPoolEntry - Test whether the given two constants
 646 /// can be allocated the same constant pool entry.
 647 static bool CanShareConstantPoolEntry(const Constant *A, const Constant *B,
 648                                       const TargetData *TD) {
 649   // Handle the trivial case quickly.
 650   if (A == B) return true;
 651
 652   // If they have the same type but weren't the same constant, quickly
 653   // reject them.
 654   if (A->getType() == B->getType()) return false;
 655
 656   // For now, only support constants with the same size.
 657   if (TD->getTypeStoreSize(A->getType()) != TD->getTypeStoreSize(B->getType()))
 658     return false;
 659
 660   // If a floating-point value and an integer value have the same encoding,
 661   // they can share a constant-pool entry.
 662   if (const ConstantFP *AFP = dyn_cast<ConstantFP>(A))
 663     if (const ConstantInt *BI = dyn_cast<ConstantInt>(B))
 664       return AFP->getValueAPF().bitcastToAPInt() == BI->getValue();
 665   if (const ConstantFP *BFP = dyn_cast<ConstantFP>(B))
 666     if (const ConstantInt *AI = dyn_cast<ConstantInt>(A))
 667       return BFP->getValueAPF().bitcastToAPInt() == AI->getValue();
 668
 669   // Two vectors can share an entry if each pair of corresponding
 670   // elements could.
 671   if (const ConstantVector *AV = dyn_cast<ConstantVector>(A))
 672     if (const ConstantVector *BV = dyn_cast<ConstantVector>(B)) {
 673       if (AV->getType()->getNumElements() != BV->getType()->getNumElements())
 674         return false;
 675       for (unsigned i = 0, e = AV->getType()->getNumElements(); i != e; ++i)
 676         if (!CanShareConstantPoolEntry(AV->getOperand(i),
 677                                        BV->getOperand(i), TD))
 678           return false;
 679       return true;
 680     }
 681
 682   // TODO: Handle other cases.
 683
 684   return false;
 685 }
 686
 687 /// getConstantPoolIndex - Create a new entry in the constant pool or return
 688 /// an existing one.  User must specify the log2 of the minimum required
 689 /// alignment for the object.
 690 ///
 691 unsigned MachineConstantPool::getConstantPoolIndex(const Constant *C,
 692                                                    unsigned Alignment) {
 693   assert(Alignment && "Alignment must be specified!");
 694   if (Alignment > PoolAlignment) PoolAlignment = Alignment;
 695
 696   // Check to see if we already have this constant.
 697   //
 698   // FIXME, this could be made much more efficient for large constant pools.
 699   for (unsigned i = 0, e = Constants.size(); i != e; ++i)
 700     if (!Constants[i].isMachineConstantPoolEntry() &&
 701         CanShareConstantPoolEntry(Constants[i].Val.ConstVal, C, TD)) {
 702       if ((unsigned)Constants[i].getAlignment() < Alignment)
 703         Constants[i].Alignment = Alignment;
 704       return i;
 705     }
 706
 707   Constants.push_back(MachineConstantPoolEntry(C, Alignment));
 708   return Constants.size()-1;
 709 }
 710
 711 unsigned MachineConstantPool::getConstantPoolIndex(MachineConstantPoolValue *V,
 712                                                    unsigned Alignment) {
 713   assert(Alignment && "Alignment must be specified!");
 714   if (Alignment > PoolAlignment) PoolAlignment = Alignment;
 715
 716   // Check to see if we already have this constant.
 717   //
 718   // FIXME, this could be made much more efficient for large constant pools.
 719   int Idx = V->getExistingMachineCPValue(this, Alignment);
 720   if (Idx != -1) {
 721     MachineCPVsSharingEntries.insert(V);
 722     return (unsigned)Idx;
 723   }
 724
 725   Constants.push_back(MachineConstantPoolEntry(V, Alignment));
 726   return Constants.size()-1;
 727 }
 728
 729 void MachineConstantPool::print(raw_ostream &OS) const {
 730   if (Constants.empty()) return;
 731
 732   OS << "Constant Pool:\n";
 733   for (unsigned i = 0, e = Constants.size(); i != e; ++i) {
 734     OS << "  cp#" << i << ": ";
 735     if (Constants[i].isMachineConstantPoolEntry())
 736       Constants[i].Val.MachineCPVal->print(OS);
 737     else
 738       OS << *(Value*)Constants[i].Val.ConstVal;
 739     OS << ", align=" << Constants[i].getAlignment();
 740     OS << "\n";
 741   }
 742 }
 743
 744 void MachineConstantPool::dump() const { print(dbgs()); }