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