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/CodeGen/MachineConstantPool.h"
  18 #include "llvm/CodeGen/MachineFunctionPass.h"
  19 #include "llvm/CodeGen/MachineFrameInfo.h"
  20 #include "llvm/CodeGen/MachineInstr.h"
  21 #include "llvm/CodeGen/MachineJumpTableInfo.h"
  22 #include "llvm/CodeGen/MachineRegisterInfo.h"
  23 #include "llvm/CodeGen/Passes.h"
  24 #include "llvm/Target/TargetData.h"
  25 #include "llvm/Target/TargetMachine.h"
  26 #include "llvm/Target/TargetFrameInfo.h"
  27 #include "llvm/Function.h"
  28 #include "llvm/Instructions.h"
  29 #include "llvm/Support/Compiler.h"
  30 #include "llvm/Support/GraphWriter.h"
  31 #include "llvm/Support/raw_ostream.h"
  32 #include "llvm/ADT/STLExtras.h"
  33 #include "llvm/Config/config.h"
  34 #include <fstream>
  35 #include <sstream>
  36 using namespace llvm;
  37
  38 bool MachineFunctionPass::runOnFunction(Function &F) {
  39   // Do not codegen any 'available_externally' functions at all, they have
  40   // definitions outside the translation unit.
  41   if (F.hasAvailableExternallyLinkage())
  42     return false;
  43
  44   return runOnMachineFunction(MachineFunction::get(&F));
  45 }
  46
  47 namespace {
  48   struct VISIBILITY_HIDDEN Printer : public MachineFunctionPass {
  49     static char ID;
  50
  51     std::ostream *OS;
  52     const std::string Banner;
  53
  54     Printer (std::ostream *os, const std::string &banner)
  55       : MachineFunctionPass(&ID), OS(os), Banner(banner) {}
  56
  57     const char *getPassName() const { return "MachineFunction Printer"; }
  58
  59     virtual void getAnalysisUsage(AnalysisUsage &AU) const {
  60       AU.setPreservesAll();
  61     }
  62
  63     bool runOnMachineFunction(MachineFunction &MF) {
  64       (*OS) << Banner;
  65       MF.print (*OS);
  66       return false;
  67     }
  68   };
  69   char Printer::ID = 0;
  70 }
  71
  72 /// Returns a newly-created MachineFunction Printer pass. The default output
  73 /// stream is std::cerr; the default banner is empty.
  74 ///
  75 FunctionPass *llvm::createMachineFunctionPrinterPass(std::ostream *OS,
  76                                                      const std::string &Banner){
  77   return new Printer(OS, Banner);
  78 }
  79
  80 namespace {
  81   struct VISIBILITY_HIDDEN Deleter : public MachineFunctionPass {
  82     static char ID;
  83     Deleter() : MachineFunctionPass(&ID) {}
  84
  85     const char *getPassName() const { return "Machine Code Deleter"; }
  86
  87     bool runOnMachineFunction(MachineFunction &MF) {
  88       // Delete the annotation from the function now.
  89       MachineFunction::destruct(MF.getFunction());
  90       return true;
  91     }
  92   };
  93   char Deleter::ID = 0;
  94 }
  95
  96 /// MachineCodeDeletion Pass - This pass deletes all of the machine code for
  97 /// the current function, which should happen after the function has been
  98 /// emitted to a .s file or to memory.
  99 FunctionPass *llvm::createMachineCodeDeleter() {
 100   return new Deleter();
 101 }
 102
 103
 104
 105 //===---------------------------------------------------------------------===//
 106 // MachineFunction implementation
 107 //===---------------------------------------------------------------------===//
 108
 109 void ilist_traits<MachineBasicBlock>::deleteNode(MachineBasicBlock *MBB) {
 110   MBB->getParent()->DeleteMachineBasicBlock(MBB);
 111 }
 112
 113 MachineFunction::MachineFunction(const Function *F,
 114                                  const TargetMachine &TM)
 115   : Annotation(AnnotationManager::getID("CodeGen::MachineCodeForFunction")),
 116     Fn(F), Target(TM) {
 117   if (TM.getRegisterInfo())
 118     RegInfo = new (Allocator.Allocate<MachineRegisterInfo>())
 119                   MachineRegisterInfo(*TM.getRegisterInfo());
 120   else
 121     RegInfo = 0;
 122   MFInfo = 0;
 123   FrameInfo = new (Allocator.Allocate<MachineFrameInfo>())
 124                   MachineFrameInfo(*TM.getFrameInfo());
 125   ConstantPool = new (Allocator.Allocate<MachineConstantPool>())
 126                      MachineConstantPool(TM.getTargetData());
 127
 128   // Set up jump table.
 129   const TargetData &TD = *TM.getTargetData();
 130   bool IsPic = TM.getRelocationModel() == Reloc::PIC_;
 131   unsigned EntrySize = IsPic ? 4 : TD.getPointerSize();
 132   unsigned Alignment = IsPic ? TD.getABITypeAlignment(Type::Int32Ty)
 133                              : TD.getPointerABIAlignment();
 134   JumpTableInfo = new (Allocator.Allocate<MachineJumpTableInfo>())
 135                       MachineJumpTableInfo(EntrySize, Alignment);
 136 }
 137
 138 MachineFunction::~MachineFunction() {
 139   BasicBlocks.clear();
 140   InstructionRecycler.clear(Allocator);
 141   BasicBlockRecycler.clear(Allocator);
 142   if (RegInfo)
 143     RegInfo->~MachineRegisterInfo();        Allocator.Deallocate(RegInfo);
 144   if (MFInfo) {
 145     MFInfo->~MachineFunctionInfo();       Allocator.Deallocate(MFInfo);
 146   }
 147   FrameInfo->~MachineFrameInfo();         Allocator.Deallocate(FrameInfo);
 148   ConstantPool->~MachineConstantPool();   Allocator.Deallocate(ConstantPool);
 149   JumpTableInfo->~MachineJumpTableInfo(); Allocator.Deallocate(JumpTableInfo);
 150 }
 151
 152
 153 /// RenumberBlocks - This discards all of the MachineBasicBlock numbers and
 154 /// recomputes them.  This guarantees that the MBB numbers are sequential,
 155 /// dense, and match the ordering of the blocks within the function.  If a
 156 /// specific MachineBasicBlock is specified, only that block and those after
 157 /// it are renumbered.
 158 void MachineFunction::RenumberBlocks(MachineBasicBlock *MBB) {
 159   if (empty()) { MBBNumbering.clear(); return; }
 160   MachineFunction::iterator MBBI, E = end();
 161   if (MBB == 0)
 162     MBBI = begin();
 163   else
 164     MBBI = MBB;
 165
 166   // Figure out the block number this should have.
 167   unsigned BlockNo = 0;
 168   if (MBBI != begin())
 169     BlockNo = prior(MBBI)->getNumber()+1;
 170
 171   for (; MBBI != E; ++MBBI, ++BlockNo) {
 172     if (MBBI->getNumber() != (int)BlockNo) {
 173       // Remove use of the old number.
 174       if (MBBI->getNumber() != -1) {
 175         assert(MBBNumbering[MBBI->getNumber()] == &*MBBI &&
 176                "MBB number mismatch!");
 177         MBBNumbering[MBBI->getNumber()] = 0;
 178       }
 179
 180       // If BlockNo is already taken, set that block's number to -1.
 181       if (MBBNumbering[BlockNo])
 182         MBBNumbering[BlockNo]->setNumber(-1);
 183
 184       MBBNumbering[BlockNo] = MBBI;
 185       MBBI->setNumber(BlockNo);
 186     }
 187   }
 188
 189   // Okay, all the blocks are renumbered.  If we have compactified the block
 190   // numbering, shrink MBBNumbering now.
 191   assert(BlockNo <= MBBNumbering.size() && "Mismatch!");
 192   MBBNumbering.resize(BlockNo);
 193 }
 194
 195 /// CreateMachineInstr - Allocate a new MachineInstr. Use this instead
 196 /// of `new MachineInstr'.
 197 ///
 198 MachineInstr *
 199 MachineFunction::CreateMachineInstr(const TargetInstrDesc &TID,
 200                                     DebugLoc DL, bool NoImp) {
 201   return new (InstructionRecycler.Allocate<MachineInstr>(Allocator))
 202     MachineInstr(TID, DL, NoImp);
 203 }
 204
 205 /// CloneMachineInstr - Create a new MachineInstr which is a copy of the
 206 /// 'Orig' instruction, identical in all ways except the the instruction
 207 /// has no parent, prev, or next.
 208 ///
 209 MachineInstr *
 210 MachineFunction::CloneMachineInstr(const MachineInstr *Orig) {
 211   return new (InstructionRecycler.Allocate<MachineInstr>(Allocator))
 212              MachineInstr(*this, *Orig);
 213 }
 214
 215 /// DeleteMachineInstr - Delete the given MachineInstr.
 216 ///
 217 void
 218 MachineFunction::DeleteMachineInstr(MachineInstr *MI) {
 219   // Clear the instructions memoperands. This must be done manually because
 220   // the instruction's parent pointer is now null, so it can't properly
 221   // deallocate them on its own.
 222   MI->clearMemOperands(*this);
 223
 224   MI->~MachineInstr();
 225   InstructionRecycler.Deallocate(Allocator, MI);
 226 }
 227
 228 /// CreateMachineBasicBlock - Allocate a new MachineBasicBlock. Use this
 229 /// instead of `new MachineBasicBlock'.
 230 ///
 231 MachineBasicBlock *
 232 MachineFunction::CreateMachineBasicBlock(const BasicBlock *bb) {
 233   return new (BasicBlockRecycler.Allocate<MachineBasicBlock>(Allocator))
 234              MachineBasicBlock(*this, bb);
 235 }
 236
 237 /// DeleteMachineBasicBlock - Delete the given MachineBasicBlock.
 238 ///
 239 void
 240 MachineFunction::DeleteMachineBasicBlock(MachineBasicBlock *MBB) {
 241   assert(MBB->getParent() == this && "MBB parent mismatch!");
 242   MBB->~MachineBasicBlock();
 243   BasicBlockRecycler.Deallocate(Allocator, MBB);
 244 }
 245
 246 void MachineFunction::dump() const {
 247   print(*cerr.stream());
 248 }
 249
 250 void MachineFunction::print(std::ostream &OS) const {
 251   OS << "# Machine code for " << Fn->getName () << "():\n";
 252
 253   // Print Frame Information
 254   FrameInfo->print(*this, OS);
 255
 256   // Print JumpTable Information
 257   JumpTableInfo->print(OS);
 258
 259   // Print Constant Pool
 260   {
 261     raw_os_ostream OSS(OS);
 262     ConstantPool->print(OSS);
 263   }
 264
 265   const TargetRegisterInfo *TRI = getTarget().getRegisterInfo();
 266
 267   if (RegInfo && !RegInfo->livein_empty()) {
 268     OS << "Live Ins:";
 269     for (MachineRegisterInfo::livein_iterator
 270          I = RegInfo->livein_begin(), E = RegInfo->livein_end(); I != E; ++I) {
 271       if (TRI)
 272         OS << " " << TRI->getName(I->first);
 273       else
 274         OS << " Reg #" << I->first;
 275
 276       if (I->second)
 277         OS << " in VR#" << I->second << " ";
 278     }
 279     OS << "\n";
 280   }
 281   if (RegInfo && !RegInfo->liveout_empty()) {
 282     OS << "Live Outs:";
 283     for (MachineRegisterInfo::liveout_iterator
 284          I = RegInfo->liveout_begin(), E = RegInfo->liveout_end(); I != E; ++I)
 285       if (TRI)
 286         OS << " " << TRI->getName(*I);
 287       else
 288         OS << " Reg #" << *I;
 289     OS << "\n";
 290   }
 291
 292   for (const_iterator BB = begin(); BB != end(); ++BB)
 293     BB->print(OS);
 294
 295   OS << "\n# End machine code for " << Fn->getName () << "().\n\n";
 296 }
 297
 298 /// CFGOnly flag - This is used to control whether or not the CFG graph printer
 299 /// prints out the contents of basic blocks or not.  This is acceptable because
 300 /// this code is only really used for debugging purposes.
 301 ///
 302 static bool CFGOnly = false;
 303
 304 namespace llvm {
 305   template<>
 306   struct DOTGraphTraits<const MachineFunction*> : public DefaultDOTGraphTraits {
 307     static std::string getGraphName(const MachineFunction *F) {
 308       return "CFG for '" + F->getFunction()->getName() + "' function";
 309     }
 310
 311     static std::string getNodeLabel(const MachineBasicBlock *Node,
 312                                     const MachineFunction *Graph) {
 313       if (CFGOnly && Node->getBasicBlock() &&
 314           !Node->getBasicBlock()->getName().empty())
 315         return Node->getBasicBlock()->getName() + ":";
 316
 317       std::ostringstream Out;
 318       if (CFGOnly) {
 319         Out << Node->getNumber() << ':';
 320         return Out.str();
 321       }
 322
 323       Node->print(Out);
 324
 325       std::string OutStr = Out.str();
 326       if (OutStr[0] == '\n') OutStr.erase(OutStr.begin());
 327
 328       // Process string output to make it nicer...
 329       for (unsigned i = 0; i != OutStr.length(); ++i)
 330         if (OutStr[i] == '\n') {                            // Left justify
 331           OutStr[i] = '\\';
 332           OutStr.insert(OutStr.begin()+i+1, 'l');
 333         }
 334       return OutStr;
 335     }
 336   };
 337 }
 338
 339 void MachineFunction::viewCFG() const
 340 {
 341 #ifndef NDEBUG
 342   ViewGraph(this, "mf" + getFunction()->getName());
 343 #else
 344   cerr << "SelectionDAG::viewGraph is only available in debug builds on "
 345        << "systems with Graphviz or gv!\n";
 346 #endif // NDEBUG
 347 }
 348
 349 void MachineFunction::viewCFGOnly() const
 350 {
 351   CFGOnly = true;
 352   viewCFG();
 353   CFGOnly = false;
 354 }
 355
 356 // The next two methods are used to construct and to retrieve
 357 // the MachineCodeForFunction object for the given function.
 358 // construct() -- Allocates and initializes for a given function and target
 359 // get()       -- Returns a handle to the object.
 360 //                This should not be called before "construct()"
 361 //                for a given Function.
 362 //
 363 MachineFunction&
 364 MachineFunction::construct(const Function *Fn, const TargetMachine &Tar)
 365 {
 366   AnnotationID MF_AID =
 367                     AnnotationManager::getID("CodeGen::MachineCodeForFunction");
 368   assert(Fn->getAnnotation(MF_AID) == 0 &&
 369          "Object already exists for this function!");
 370   MachineFunction* mcInfo = new MachineFunction(Fn, Tar);
 371   Fn->addAnnotation(mcInfo);
 372   return *mcInfo;
 373 }
 374
 375 void MachineFunction::destruct(const Function *Fn) {
 376   AnnotationID MF_AID =
 377                     AnnotationManager::getID("CodeGen::MachineCodeForFunction");
 378   bool Deleted = Fn->deleteAnnotation(MF_AID);
 379   assert(Deleted && "Machine code did not exist for function!");
 380   Deleted = Deleted; // silence warning when no assertions.
 381 }
 382
 383 MachineFunction& MachineFunction::get(const Function *F)
 384 {
 385   AnnotationID MF_AID =
 386                     AnnotationManager::getID("CodeGen::MachineCodeForFunction");
 387   MachineFunction *mc = (MachineFunction*)F->getAnnotation(MF_AID);
 388   assert(mc && "Call construct() method first to allocate the object");
 389   return *mc;
 390 }
 391
 392 /// addLiveIn - Add the specified physical register as a live-in value and
 393 /// create a corresponding virtual register for it.
 394 unsigned MachineFunction::addLiveIn(unsigned PReg,
 395                                     const TargetRegisterClass *RC) {
 396   assert(RC->contains(PReg) && "Not the correct regclass!");
 397   unsigned VReg = getRegInfo().createVirtualRegister(RC);
 398   getRegInfo().addLiveIn(PReg, VReg);
 399   return VReg;
 400 }
 401
 402 /// getOrCreateDebugLocID - Look up the DebugLocTuple index with the given
 403 /// source file, line, and column. If none currently exists, create a new
 404 /// DebugLocTuple, and insert it into the DebugIdMap.
 405 unsigned MachineFunction::getOrCreateDebugLocID(GlobalVariable *CompileUnit,
 406                                                 unsigned Line, unsigned Col) {
 407   DebugLocTuple Tuple(CompileUnit, Line, Col);
 408   DenseMap<DebugLocTuple, unsigned>::iterator II
 409     = DebugLocInfo.DebugIdMap.find(Tuple);
 410   if (II != DebugLocInfo.DebugIdMap.end())
 411     return II->second;
 412   // Add a new tuple.
 413   unsigned Id = DebugLocInfo.DebugLocations.size();
 414   DebugLocInfo.DebugLocations.push_back(Tuple);
 415   DebugLocInfo.DebugIdMap[Tuple] = Id;
 416   return Id;
 417 }
 418
 419 /// getDebugLocTuple - Get the DebugLocTuple for a given DebugLoc object.
 420 DebugLocTuple MachineFunction::getDebugLocTuple(DebugLoc DL) const {
 421   unsigned Idx = DL.getIndex();
 422   assert(Idx < DebugLocInfo.DebugLocations.size() &&
 423          "Invalid index into debug locations!");
 424   return DebugLocInfo.DebugLocations[Idx];
 425 }
 426
 427 //===----------------------------------------------------------------------===//
 428 //  MachineFrameInfo implementation
 429 //===----------------------------------------------------------------------===//
 430
 431 /// CreateFixedObject - Create a new object at a fixed location on the stack.
 432 /// All fixed objects should be created before other objects are created for
 433 /// efficiency. By default, fixed objects are immutable. This returns an
 434 /// index with a negative value.
 435 ///
 436 int MachineFrameInfo::CreateFixedObject(uint64_t Size, int64_t SPOffset,
 437                                         bool Immutable) {
 438   assert(Size != 0 && "Cannot allocate zero size fixed stack objects!");
 439   Objects.insert(Objects.begin(), StackObject(Size, 1, SPOffset, Immutable));
 440   return -++NumFixedObjects;
 441 }
 442
 443
 444 void MachineFrameInfo::print(const MachineFunction &MF, std::ostream &OS) const{
 445   const TargetFrameInfo *FI = MF.getTarget().getFrameInfo();
 446   int ValOffset = (FI ? FI->getOffsetOfLocalArea() : 0);
 447
 448   for (unsigned i = 0, e = Objects.size(); i != e; ++i) {
 449     const StackObject &SO = Objects[i];
 450     OS << "  <fi#" << (int)(i-NumFixedObjects) << ">: ";
 451     if (SO.Size == ~0ULL) {
 452       OS << "dead\n";
 453       continue;
 454     }
 455     if (SO.Size == 0)
 456       OS << "variable sized";
 457     else
 458       OS << "size is " << SO.Size << " byte" << (SO.Size != 1 ? "s," : ",");
 459     OS << " alignment is " << SO.Alignment << " byte"
 460        << (SO.Alignment != 1 ? "s," : ",");
 461
 462     if (i < NumFixedObjects)
 463       OS << " fixed";
 464     if (i < NumFixedObjects || SO.SPOffset != -1) {
 465       int64_t Off = SO.SPOffset - ValOffset;
 466       OS << " at location [SP";
 467       if (Off > 0)
 468         OS << "+" << Off;
 469       else if (Off < 0)
 470         OS << Off;
 471       OS << "]";
 472     }
 473     OS << "\n";
 474   }
 475
 476   if (HasVarSizedObjects)
 477     OS << "  Stack frame contains variable sized objects\n";
 478 }
 479
 480 void MachineFrameInfo::dump(const MachineFunction &MF) const {
 481   print(MF, *cerr.stream());
 482 }
 483
 484
 485 //===----------------------------------------------------------------------===//
 486 //  MachineJumpTableInfo implementation
 487 //===----------------------------------------------------------------------===//
 488
 489 /// getJumpTableIndex - Create a new jump table entry in the jump table info
 490 /// or return an existing one.
 491 ///
 492 unsigned MachineJumpTableInfo::getJumpTableIndex(
 493                                const std::vector<MachineBasicBlock*> &DestBBs) {
 494   assert(!DestBBs.empty() && "Cannot create an empty jump table!");
 495   for (unsigned i = 0, e = JumpTables.size(); i != e; ++i)
 496     if (JumpTables[i].MBBs == DestBBs)
 497       return i;
 498
 499   JumpTables.push_back(MachineJumpTableEntry(DestBBs));
 500   return JumpTables.size()-1;
 501 }
 502
 503 /// ReplaceMBBInJumpTables - If Old is the target of any jump tables, update
 504 /// the jump tables to branch to New instead.
 505 bool
 506 MachineJumpTableInfo::ReplaceMBBInJumpTables(MachineBasicBlock *Old,
 507                                              MachineBasicBlock *New) {
 508   assert(Old != New && "Not making a change?");
 509   bool MadeChange = false;
 510   for (size_t i = 0, e = JumpTables.size(); i != e; ++i) {
 511     MachineJumpTableEntry &JTE = JumpTables[i];
 512     for (size_t j = 0, e = JTE.MBBs.size(); j != e; ++j)
 513       if (JTE.MBBs[j] == Old) {
 514         JTE.MBBs[j] = New;
 515         MadeChange = true;
 516       }
 517   }
 518   return MadeChange;
 519 }
 520
 521 void MachineJumpTableInfo::print(std::ostream &OS) const {
 522   // FIXME: this is lame, maybe we could print out the MBB numbers or something
 523   // like {1, 2, 4, 5, 3, 0}
 524   for (unsigned i = 0, e = JumpTables.size(); i != e; ++i) {
 525     OS << "  <jt#" << i << "> has " << JumpTables[i].MBBs.size()
 526        << " entries\n";
 527   }
 528 }
 529
 530 void MachineJumpTableInfo::dump() const { print(*cerr.stream()); }
 531
 532
 533 //===----------------------------------------------------------------------===//
 534 //  MachineConstantPool implementation
 535 //===----------------------------------------------------------------------===//
 536
 537 const Type *MachineConstantPoolEntry::getType() const {
 538   if (isMachineConstantPoolEntry())
 539       return Val.MachineCPVal->getType();
 540   return Val.ConstVal->getType();
 541 }
 542
 543 MachineConstantPool::~MachineConstantPool() {
 544   for (unsigned i = 0, e = Constants.size(); i != e; ++i)
 545     if (Constants[i].isMachineConstantPoolEntry())
 546       delete Constants[i].Val.MachineCPVal;
 547 }
 548
 549 /// getConstantPoolIndex - Create a new entry in the constant pool or return
 550 /// an existing one.  User must specify the log2 of the minimum required
 551 /// alignment for the object.
 552 ///
 553 unsigned MachineConstantPool::getConstantPoolIndex(Constant *C,
 554                                                    unsigned Alignment) {
 555   assert(Alignment && "Alignment must be specified!");
 556   if (Alignment > PoolAlignment) PoolAlignment = Alignment;
 557
 558   // Check to see if we already have this constant.
 559   //
 560   // FIXME, this could be made much more efficient for large constant pools.
 561   for (unsigned i = 0, e = Constants.size(); i != e; ++i)
 562     if (Constants[i].Val.ConstVal == C &&
 563         (Constants[i].getAlignment() & (Alignment - 1)) == 0)
 564       return i;
 565
 566   Constants.push_back(MachineConstantPoolEntry(C, Alignment));
 567   return Constants.size()-1;
 568 }
 569
 570 unsigned MachineConstantPool::getConstantPoolIndex(MachineConstantPoolValue *V,
 571                                                    unsigned Alignment) {
 572   assert(Alignment && "Alignment must be specified!");
 573   if (Alignment > PoolAlignment) PoolAlignment = Alignment;
 574
 575   // Check to see if we already have this constant.
 576   //
 577   // FIXME, this could be made much more efficient for large constant pools.
 578   int Idx = V->getExistingMachineCPValue(this, Alignment);
 579   if (Idx != -1)
 580     return (unsigned)Idx;
 581
 582   Constants.push_back(MachineConstantPoolEntry(V, Alignment));
 583   return Constants.size()-1;
 584 }
 585
 586 void MachineConstantPool::print(raw_ostream &OS) const {
 587   for (unsigned i = 0, e = Constants.size(); i != e; ++i) {
 588     OS << "  <cp#" << i << "> is";
 589     if (Constants[i].isMachineConstantPoolEntry())
 590       Constants[i].Val.MachineCPVal->print(OS);
 591     else
 592       OS << *(Value*)Constants[i].Val.ConstVal;
 593     OS << " , alignment=" << Constants[i].getAlignment();
 594     OS << "\n";
 595   }
 596 }
 597
 598 void MachineConstantPool::dump() const { print(errs()); }