lib/CodeGen/MachineFunction.cpp

   1 //===-- MachineFunction.cpp -----------------------------------------------===//
   2 //
   3 //                     The LLVM Compiler Infrastructure
   4 //
   5 // This file was developed by the LLVM research group and is distributed under
   6 // the University of Illinois Open Source License. See LICENSE.TXT for details.
   7 //
   8 //===----------------------------------------------------------------------===//
   9 //
  10 // Collect native machine code information for a function.  This allows
  11 // target-specific information about the generated code to be stored with each
  12 // function.
  13 //
  14 //===----------------------------------------------------------------------===//
  15
  16 #include "llvm/CodeGen/MachineFunctionPass.h"
  17 #include "llvm/CodeGen/MachineInstr.h"
  18 #include "llvm/CodeGen/SSARegMap.h"
  19 #include "llvm/CodeGen/MachineFrameInfo.h"
  20 #include "llvm/CodeGen/MachineConstantPool.h"
  21 #include "llvm/CodeGen/MachineJumpTableInfo.h"
  22 #include "llvm/CodeGen/Passes.h"
  23 #include "llvm/Target/TargetData.h"
  24 #include "llvm/Target/TargetMachine.h"
  25 #include "llvm/Target/TargetFrameInfo.h"
  26 #include "llvm/Function.h"
  27 #include "llvm/Instructions.h"
  28 #include "llvm/Support/LeakDetector.h"
  29 #include "llvm/Support/GraphWriter.h"
  30 #include "llvm/Support/Visibility.h"
  31 #include "llvm/Config/config.h"
  32 #include <fstream>
  33 #include <iostream>
  34 #include <sstream>
  35
  36 using namespace llvm;
  37
  38 static AnnotationID MF_AID(
  39   AnnotationManager::getID("CodeGen::MachineCodeForFunction"));
  40
  41 // Out of line virtual function to home classes.
  42 void MachineFunctionPass::virtfn() {}
  43
  44 namespace {
  45   struct VISIBILITY_HIDDEN Printer : public MachineFunctionPass {
  46     std::ostream *OS;
  47     const std::string Banner;
  48
  49     Printer (std::ostream *_OS, const std::string &_Banner) :
  50       OS (_OS), Banner (_Banner) { }
  51
  52     const char *getPassName() const { return "MachineFunction Printer"; }
  53
  54     virtual void getAnalysisUsage(AnalysisUsage &AU) const {
  55       AU.setPreservesAll();
  56     }
  57
  58     bool runOnMachineFunction(MachineFunction &MF) {
  59       (*OS) << Banner;
  60       MF.print (*OS);
  61       return false;
  62     }
  63   };
  64 }
  65
  66 /// Returns a newly-created MachineFunction Printer pass. The default output
  67 /// stream is std::cerr; the default banner is empty.
  68 ///
  69 FunctionPass *llvm::createMachineFunctionPrinterPass(std::ostream *OS,
  70                                                      const std::string &Banner){
  71   return new Printer(OS, Banner);
  72 }
  73
  74 namespace {
  75   struct VISIBILITY_HIDDEN Deleter : public MachineFunctionPass {
  76     const char *getPassName() const { return "Machine Code Deleter"; }
  77
  78     bool runOnMachineFunction(MachineFunction &MF) {
  79       // Delete the annotation from the function now.
  80       MachineFunction::destruct(MF.getFunction());
  81       return true;
  82     }
  83   };
  84 }
  85
  86 /// MachineCodeDeletion Pass - This pass deletes all of the machine code for
  87 /// the current function, which should happen after the function has been
  88 /// emitted to a .s file or to memory.
  89 FunctionPass *llvm::createMachineCodeDeleter() {
  90   return new Deleter();
  91 }
  92
  93
  94
  95 //===---------------------------------------------------------------------===//
  96 // MachineFunction implementation
  97 //===---------------------------------------------------------------------===//
  98
  99 MachineBasicBlock* ilist_traits<MachineBasicBlock>::createSentinel() {
 100   MachineBasicBlock* dummy = new MachineBasicBlock();
 101   LeakDetector::removeGarbageObject(dummy);
 102   return dummy;
 103 }
 104
 105 void ilist_traits<MachineBasicBlock>::transferNodesFromList(
 106   iplist<MachineBasicBlock, ilist_traits<MachineBasicBlock> >& toList,
 107   ilist_iterator<MachineBasicBlock> first,
 108   ilist_iterator<MachineBasicBlock> last) {
 109   if (Parent != toList.Parent)
 110     for (; first != last; ++first)
 111       first->Parent = toList.Parent;
 112 }
 113
 114 MachineFunction::MachineFunction(const Function *F,
 115                                  const TargetMachine &TM)
 116   : Annotation(MF_AID), Fn(F), Target(TM), UsedPhysRegs(0) {
 117   SSARegMapping = new SSARegMap();
 118   MFInfo = 0;
 119   FrameInfo = new MachineFrameInfo();
 120   ConstantPool = new MachineConstantPool(TM.getTargetData());
 121   JumpTableInfo = new MachineJumpTableInfo(TM.getTargetData());
 122   BasicBlocks.Parent = this;
 123 }
 124
 125 MachineFunction::~MachineFunction() {
 126   BasicBlocks.clear();
 127   delete SSARegMapping;
 128   delete MFInfo;
 129   delete FrameInfo;
 130   delete ConstantPool;
 131   delete JumpTableInfo;
 132   delete[] UsedPhysRegs;
 133 }
 134
 135 void MachineFunction::dump() const { print(std::cerr); }
 136
 137 void MachineFunction::print(std::ostream &OS) const {
 138   OS << "# Machine code for " << Fn->getName () << "():\n";
 139
 140   // Print Frame Information
 141   getFrameInfo()->print(*this, OS);
 142
 143   // Print JumpTable Information
 144   getJumpTableInfo()->print(OS);
 145
 146   // Print Constant Pool
 147   getConstantPool()->print(OS);
 148
 149   const MRegisterInfo *MRI = getTarget().getRegisterInfo();
 150
 151   if (livein_begin() != livein_end()) {
 152     OS << "Live Ins:";
 153     for (livein_iterator I = livein_begin(), E = livein_end(); I != E; ++I) {
 154       if (MRI)
 155         OS << " " << MRI->getName(I->first);
 156       else
 157         OS << " Reg #" << I->first;
 158
 159       if (I->second)
 160         OS << " in VR#" << I->second << " ";
 161     }
 162     OS << "\n";
 163   }
 164   if (liveout_begin() != liveout_end()) {
 165     OS << "Live Outs:";
 166     for (liveout_iterator I = liveout_begin(), E = liveout_end(); I != E; ++I)
 167       if (MRI)
 168         OS << " " << MRI->getName(*I);
 169       else
 170         OS << " Reg #" << *I;
 171     OS << "\n";
 172   }
 173
 174   for (const_iterator BB = begin(); BB != end(); ++BB)
 175     BB->print(OS);
 176
 177   OS << "\n# End machine code for " << Fn->getName () << "().\n\n";
 178 }
 179
 180 /// CFGOnly flag - This is used to control whether or not the CFG graph printer
 181 /// prints out the contents of basic blocks or not.  This is acceptable because
 182 /// this code is only really used for debugging purposes.
 183 ///
 184 static bool CFGOnly = false;
 185
 186 namespace llvm {
 187   template<>
 188   struct DOTGraphTraits<const MachineFunction*> : public DefaultDOTGraphTraits {
 189     static std::string getGraphName(const MachineFunction *F) {
 190       return "CFG for '" + F->getFunction()->getName() + "' function";
 191     }
 192
 193     static std::string getNodeLabel(const MachineBasicBlock *Node,
 194                                     const MachineFunction *Graph) {
 195       if (CFGOnly && Node->getBasicBlock() &&
 196           !Node->getBasicBlock()->getName().empty())
 197         return Node->getBasicBlock()->getName() + ":";
 198
 199       std::ostringstream Out;
 200       if (CFGOnly) {
 201         Out << Node->getNumber() << ':';
 202         return Out.str();
 203       }
 204
 205       Node->print(Out);
 206
 207       std::string OutStr = Out.str();
 208       if (OutStr[0] == '\n') OutStr.erase(OutStr.begin());
 209
 210       // Process string output to make it nicer...
 211       for (unsigned i = 0; i != OutStr.length(); ++i)
 212         if (OutStr[i] == '\n') {                            // Left justify
 213           OutStr[i] = '\\';
 214           OutStr.insert(OutStr.begin()+i+1, 'l');
 215         }
 216       return OutStr;
 217     }
 218   };
 219 }
 220
 221 void MachineFunction::viewCFG() const
 222 {
 223 #ifndef NDEBUG
 224   ViewGraph(this, "mf" + getFunction()->getName());
 225 #else
 226   std::cerr << "SelectionDAG::viewGraph is only available in debug builds on "
 227             << "systems with Graphviz or gv!\n";
 228 #endif // NDEBUG
 229 }
 230
 231 void MachineFunction::viewCFGOnly() const
 232 {
 233   CFGOnly = true;
 234   viewCFG();
 235   CFGOnly = false;
 236 }
 237
 238 // The next two methods are used to construct and to retrieve
 239 // the MachineCodeForFunction object for the given function.
 240 // construct() -- Allocates and initializes for a given function and target
 241 // get()       -- Returns a handle to the object.
 242 //                This should not be called before "construct()"
 243 //                for a given Function.
 244 //
 245 MachineFunction&
 246 MachineFunction::construct(const Function *Fn, const TargetMachine &Tar)
 247 {
 248   assert(Fn->getAnnotation(MF_AID) == 0 &&
 249          "Object already exists for this function!");
 250   MachineFunction* mcInfo = new MachineFunction(Fn, Tar);
 251   Fn->addAnnotation(mcInfo);
 252   return *mcInfo;
 253 }
 254
 255 void MachineFunction::destruct(const Function *Fn) {
 256   bool Deleted = Fn->deleteAnnotation(MF_AID);
 257   assert(Deleted && "Machine code did not exist for function!");
 258 }
 259
 260 MachineFunction& MachineFunction::get(const Function *F)
 261 {
 262   MachineFunction *mc = (MachineFunction*)F->getAnnotation(MF_AID);
 263   assert(mc && "Call construct() method first to allocate the object");
 264   return *mc;
 265 }
 266
 267 void MachineFunction::clearSSARegMap() {
 268   delete SSARegMapping;
 269   SSARegMapping = 0;
 270 }
 271
 272 //===----------------------------------------------------------------------===//
 273 //  MachineFrameInfo implementation
 274 //===----------------------------------------------------------------------===//
 275
 276 void MachineFrameInfo::print(const MachineFunction &MF, std::ostream &OS) const{
 277   int ValOffset = MF.getTarget().getFrameInfo()->getOffsetOfLocalArea();
 278
 279   for (unsigned i = 0, e = Objects.size(); i != e; ++i) {
 280     const StackObject &SO = Objects[i];
 281     OS << "  <fi #" << (int)(i-NumFixedObjects) << ">: ";
 282     if (SO.Size == 0)
 283       OS << "variable sized";
 284     else
 285       OS << "size is " << SO.Size << " byte" << (SO.Size != 1 ? "s," : ",");
 286     OS << " alignment is " << SO.Alignment << " byte"
 287        << (SO.Alignment != 1 ? "s," : ",");
 288
 289     if (i < NumFixedObjects)
 290       OS << " fixed";
 291     if (i < NumFixedObjects || SO.SPOffset != -1) {
 292       int Off = SO.SPOffset - ValOffset;
 293       OS << " at location [SP";
 294       if (Off > 0)
 295         OS << "+" << Off;
 296       else if (Off < 0)
 297         OS << Off;
 298       OS << "]";
 299     }
 300     OS << "\n";
 301   }
 302
 303   if (HasVarSizedObjects)
 304     OS << "  Stack frame contains variable sized objects\n";
 305 }
 306
 307 void MachineFrameInfo::dump(const MachineFunction &MF) const {
 308   print(MF, std::cerr);
 309 }
 310
 311
 312 //===----------------------------------------------------------------------===//
 313 //  MachineJumpTableInfo implementation
 314 //===----------------------------------------------------------------------===//
 315
 316 /// getJumpTableIndex - Create a new jump table entry in the jump table info
 317 /// or return an existing one.
 318 ///
 319 unsigned MachineJumpTableInfo::getJumpTableIndex(
 320                                      std::vector<MachineBasicBlock*> &DestBBs) {
 321   for (unsigned i = 0, e = JumpTables.size(); i != e; ++i)
 322     if (JumpTables[i].MBBs == DestBBs)
 323       return i;
 324
 325   JumpTables.push_back(MachineJumpTableEntry(DestBBs));
 326   return JumpTables.size()-1;
 327 }
 328
 329
 330 void MachineJumpTableInfo::print(std::ostream &OS) const {
 331   // FIXME: this is lame, maybe we could print out the MBB numbers or something
 332   // like {1, 2, 4, 5, 3, 0}
 333   for (unsigned i = 0, e = JumpTables.size(); i != e; ++i) {
 334     OS << "  <jt #" << i << "> has " << JumpTables[i].MBBs.size()
 335        << " entries\n";
 336   }
 337 }
 338
 339 unsigned MachineJumpTableInfo::getEntrySize() const {
 340   return TD->getPointerSize();
 341 }
 342
 343 unsigned MachineJumpTableInfo::getAlignment() const {
 344   return TD->getPointerAlignment();
 345 }
 346
 347 void MachineJumpTableInfo::dump() const { print(std::cerr); }
 348
 349
 350 //===----------------------------------------------------------------------===//
 351 //  MachineConstantPool implementation
 352 //===----------------------------------------------------------------------===//
 353
 354 /// getConstantPoolIndex - Create a new entry in the constant pool or return
 355 /// an existing one.  User must specify an alignment in bytes for the object.
 356 ///
 357 unsigned MachineConstantPool::getConstantPoolIndex(Constant *C,
 358                                                    unsigned Alignment) {
 359   assert(Alignment && "Alignment must be specified!");
 360   if (Alignment > PoolAlignment) PoolAlignment = Alignment;
 361
 362   // Check to see if we already have this constant.
 363   //
 364   // FIXME, this could be made much more efficient for large constant pools.
 365   unsigned AlignMask = (1 << Alignment)-1;
 366   for (unsigned i = 0, e = Constants.size(); i != e; ++i)
 367     if (Constants[i].Val == C && (Constants[i].Offset & AlignMask) == 0)
 368       return i;
 369
 370   unsigned Offset = 0;
 371   if (!Constants.empty()) {
 372     Offset = Constants.back().Offset;
 373     Offset += TD->getTypeSize(Constants.back().Val->getType());
 374     Offset = (Offset+AlignMask)&~AlignMask;
 375   }
 376
 377   Constants.push_back(MachineConstantPoolEntry(C, Offset));
 378   return Constants.size()-1;
 379 }
 380
 381
 382 void MachineConstantPool::print(std::ostream &OS) const {
 383   for (unsigned i = 0, e = Constants.size(); i != e; ++i) {
 384     OS << "  <cp #" << i << "> is" << *(Value*)Constants[i].Val;
 385     OS << " , offset=" << Constants[i].Offset;
 386     OS << "\n";
 387   }
 388 }
 389
 390 void MachineConstantPool::dump() const { print(std::cerr); }