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