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.isClobber() != Res.isDef() &&
  83              "Local dep should be 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.isClobber() != Res.isDef() &&
  96                "Resolved non-local call dep should be def or clobber!");
  97         InstDeps.insert(std::make_pair(InstAndClobberFlag(Res.getInst(),
  98                                                           Res.isClobber()),
  99                                        I->getBB()));
 100       }
 101     } else {
 102       SmallVector<NonLocalDepResult, 4> NLDI;
 103       if (LoadInst *LI = dyn_cast<LoadInst>(Inst)) {
 104         // FIXME: Volatile is not handled properly here.
 105         AliasAnalysis::Location Loc = AA.getLocation(LI);
 106         MDA.getNonLocalPointerDependency(Loc, !LI->isVolatile(),
 107                                          LI->getParent(), NLDI);
 108       } else if (StoreInst *SI = dyn_cast<StoreInst>(Inst)) {
 109         // FIXME: Volatile is not handled properly here.
 110         AliasAnalysis::Location Loc = AA.getLocation(SI);
 111         MDA.getNonLocalPointerDependency(Loc, false, SI->getParent(), NLDI);
 112       } else if (VAArgInst *VI = dyn_cast<VAArgInst>(Inst)) {
 113         AliasAnalysis::Location Loc = AA.getLocation(VI);
 114         MDA.getNonLocalPointerDependency(Loc, false, VI->getParent(), NLDI);
 115       } else {
 116         llvm_unreachable("Unknown memory instruction!");
 117       }
 118
 119       DepSet &InstDeps = Deps[Inst];
 120       for (SmallVectorImpl<NonLocalDepResult>::const_iterator
 121            I = NLDI.begin(), E = NLDI.end(); I != E; ++I) {
 122         const MemDepResult &Res = I->getResult();
 123         assert(Res.isClobber() != Res.isDef() &&
 124                "Resolved non-local pointer dep should be def or clobber!");
 125         InstDeps.insert(std::make_pair(InstAndClobberFlag(Res.getInst(),
 126                                                           Res.isClobber()),
 127                                        I->getBB()));
 128       }
 129     }
 130   }
 131
 132   return false;
 133 }
 134
 135 void MemDepPrinter::print(raw_ostream &OS, const Module *M) const {
 136   for (const_inst_iterator I = inst_begin(*F), E = inst_end(*F); I != E; ++I) {
 137     const Instruction *Inst = &*I;
 138
 139     DepSetMap::const_iterator DI = Deps.find(Inst);
 140     if (DI == Deps.end())
 141       continue;
 142
 143     const DepSet &InstDeps = DI->second;
 144
 145     for (DepSet::const_iterator I = InstDeps.begin(), E = InstDeps.end();
 146          I != E; ++I) {
 147       const Instruction *DepInst = I->first.getPointer();
 148       bool isClobber = I->first.getInt();
 149       const BasicBlock *DepBB = I->second;
 150
 151       OS << "    " << (isClobber ? "Clobber" : "    Def");
 152       if (DepBB) {
 153         OS << " in block ";
 154         WriteAsOperand(OS, DepBB, /*PrintType=*/false, M);
 155       }
 156       OS << " from: ";
 157       if (DepInst == Inst)
 158         OS << "<unspecified>";
 159       else
 160         DepInst->print(OS);
 161       OS << "\n";
 162     }
 163
 164     Inst->print(OS);
 165     OS << "\n\n";
 166   }
 167 }