src/llvm/lib/Analysis/MemDepPrinter.cpp

   1 //===- MemDepPrinter.cpp - Printer for MemoryDependenceAnalysis -----------===//
   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 //
  11 //===----------------------------------------------------------------------===//
  12
  13 #include "llvm/Analysis/Passes.h"
  14 #include "llvm/ADT/SetVector.h"
  15 #include "llvm/Analysis/MemoryDependenceAnalysis.h"
  16 #include "llvm/Assembly/Writer.h"
  17 #include "llvm/IR/LLVMContext.h"
  18 #include "llvm/Support/CallSite.h"
  19 #include "llvm/Support/ErrorHandling.h"
  20 #include "llvm/Support/InstIterator.h"
  21 #include "llvm/Support/raw_ostream.h"
  22 using namespace llvm;
  23
  24 namespace {
  25   struct MemDepPrinter : public FunctionPass {
  26     const Function *F;
  27
  28     enum DepType {
  29       Clobber = 0,
  30       Def,
  31       NonFuncLocal,
  32       Unknown
  33     };
  34
  35     static const char *const DepTypeStr[];
  36
  37     typedef PointerIntPair<const Instruction *, 2, DepType> InstTypePair;
  38     typedef std::pair<InstTypePair, const BasicBlock *> Dep;
  39     typedef SmallSetVector<Dep, 4> DepSet;
  40     typedef DenseMap<const Instruction *, DepSet> DepSetMap;
  41     DepSetMap Deps;
  42
  43     static char ID; // Pass identifcation, replacement for typeid
  44     MemDepPrinter() : FunctionPass(ID) {
  45       initializeMemDepPrinterPass(*PassRegistry::getPassRegistry());
  46     }
  47
  48     virtual bool runOnFunction(Function &F);
  49
  50     void print(raw_ostream &OS, const Module * = 0) const;
  51
  52     virtual void getAnalysisUsage(AnalysisUsage &AU) const {
  53       AU.addRequiredTransitive<AliasAnalysis>();
  54       AU.addRequiredTransitive<MemoryDependenceAnalysis>();
  55       AU.setPreservesAll();
  56     }
  57
  58     virtual void releaseMemory() {
  59       Deps.clear();
  60       F = 0;
  61     }
  62
  63   private:
  64     static InstTypePair getInstTypePair(MemDepResult dep) {
  65       if (dep.isClobber())
  66         return InstTypePair(dep.getInst(), Clobber);
  67       if (dep.isDef())
  68         return InstTypePair(dep.getInst(), Def);
  69       if (dep.isNonFuncLocal())
  70         return InstTypePair(dep.getInst(), NonFuncLocal);
  71       assert(dep.isUnknown() && "unexptected dependence type");
  72       return InstTypePair(dep.getInst(), Unknown);
  73     }
  74     static InstTypePair getInstTypePair(const Instruction* inst, DepType type) {
  75       return InstTypePair(inst, type);
  76     }
  77   };
  78 }
  79
  80 char MemDepPrinter::ID = 0;
  81 INITIALIZE_PASS_BEGIN(MemDepPrinter, "print-memdeps",
  82                       "Print MemDeps of function", false, true)
  83 INITIALIZE_PASS_DEPENDENCY(MemoryDependenceAnalysis)
  84 INITIALIZE_PASS_END(MemDepPrinter, "print-memdeps",
  85                       "Print MemDeps of function", false, true)
  86
  87 FunctionPass *llvm::createMemDepPrinter() {
  88   return new MemDepPrinter();
  89 }
  90
  91 const char *const MemDepPrinter::DepTypeStr[]
  92   = {"Clobber", "Def", "NonFuncLocal", "Unknown"};
  93
  94 bool MemDepPrinter::runOnFunction(Function &F) {
  95   this->F = &F;
  96   AliasAnalysis &AA = getAnalysis<AliasAnalysis>();
  97   MemoryDependenceAnalysis &MDA = getAnalysis<MemoryDependenceAnalysis>();
  98
  99   // All this code uses non-const interfaces because MemDep is not
 100   // const-friendly, though nothing is actually modified.
 101   for (inst_iterator I = inst_begin(F), E = inst_end(F); I != E; ++I) {
 102     Instruction *Inst = &*I;
 103
 104     if (!Inst->mayReadFromMemory() && !Inst->mayWriteToMemory())
 105       continue;
 106
 107     MemDepResult Res = MDA.getDependency(Inst);
 108     if (!Res.isNonLocal()) {
 109       Deps[Inst].insert(std::make_pair(getInstTypePair(Res),
 110                                        static_cast<BasicBlock *>(0)));
 111     } else if (CallSite CS = cast<Value>(Inst)) {
 112       const MemoryDependenceAnalysis::NonLocalDepInfo &NLDI =
 113         MDA.getNonLocalCallDependency(CS);
 114
 115       DepSet &InstDeps = Deps[Inst];
 116       for (MemoryDependenceAnalysis::NonLocalDepInfo::const_iterator
 117            I = NLDI.begin(), E = NLDI.end(); I != E; ++I) {
 118         const MemDepResult &Res = I->getResult();
 119         InstDeps.insert(std::make_pair(getInstTypePair(Res), I->getBB()));
 120       }
 121     } else {
 122       SmallVector<NonLocalDepResult, 4> NLDI;
 123       if (LoadInst *LI = dyn_cast<LoadInst>(Inst)) {
 124         if (!LI->isUnordered()) {
 125           // FIXME: Handle atomic/volatile loads.
 126           Deps[Inst].insert(std::make_pair(getInstTypePair(0, Unknown),
 127                                            static_cast<BasicBlock *>(0)));
 128           continue;
 129         }
 130         AliasAnalysis::Location Loc = AA.getLocation(LI);
 131         MDA.getNonLocalPointerDependency(Loc, true, LI->getParent(), NLDI);
 132       } else if (StoreInst *SI = dyn_cast<StoreInst>(Inst)) {
 133         if (!SI->isUnordered()) {
 134           // FIXME: Handle atomic/volatile stores.
 135           Deps[Inst].insert(std::make_pair(getInstTypePair(0, Unknown),
 136                                            static_cast<BasicBlock *>(0)));
 137           continue;
 138         }
 139         AliasAnalysis::Location Loc = AA.getLocation(SI);
 140         MDA.getNonLocalPointerDependency(Loc, false, SI->getParent(), NLDI);
 141       } else if (VAArgInst *VI = dyn_cast<VAArgInst>(Inst)) {
 142         AliasAnalysis::Location Loc = AA.getLocation(VI);
 143         MDA.getNonLocalPointerDependency(Loc, false, VI->getParent(), NLDI);
 144       } else {
 145         llvm_unreachable("Unknown memory instruction!");
 146       }
 147
 148       DepSet &InstDeps = Deps[Inst];
 149       for (SmallVectorImpl<NonLocalDepResult>::const_iterator
 150            I = NLDI.begin(), E = NLDI.end(); I != E; ++I) {
 151         const MemDepResult &Res = I->getResult();
 152         InstDeps.insert(std::make_pair(getInstTypePair(Res), I->getBB()));
 153       }
 154     }
 155   }
 156
 157   return false;
 158 }
 159
 160 void MemDepPrinter::print(raw_ostream &OS, const Module *M) const {
 161   for (const_inst_iterator I = inst_begin(*F), E = inst_end(*F); I != E; ++I) {
 162     const Instruction *Inst = &*I;
 163
 164     DepSetMap::const_iterator DI = Deps.find(Inst);
 165     if (DI == Deps.end())
 166       continue;
 167
 168     const DepSet &InstDeps = DI->second;
 169
 170     for (DepSet::const_iterator I = InstDeps.begin(), E = InstDeps.end();
 171          I != E; ++I) {
 172       const Instruction *DepInst = I->first.getPointer();
 173       DepType type = I->first.getInt();
 174       const BasicBlock *DepBB = I->second;
 175
 176       OS << "    ";
 177       OS << DepTypeStr[type];
 178       if (DepBB) {
 179         OS << " in block ";
 180         WriteAsOperand(OS, DepBB, /*PrintType=*/false, M);
 181       }
 182       if (DepInst) {
 183         OS << " from: ";
 184         DepInst->print(OS);
 185       }
 186       OS << "\n";
 187     }
 188
 189     Inst->print(OS);
 190     OS << "\n\n";
 191   }
 192 }