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