// Test whether two basic blocks have equivalent behaviour.
int FunctionComparator::cmpBasicBlocks(const BasicBlock *BBL,
                                       const BasicBlock *BBR) const {
  BasicBlock::const_iterator InstL = BBL->begin(), InstLE = BBL->end();
  BasicBlock::const_iterator InstR = BBR->begin(), InstRE = BBR->end();

  do {
    bool needToCmpOperands = true;
    if (int Res = cmpOperations(&*InstL, &*InstR, needToCmpOperands))
      return Res;
    if (needToCmpOperands) {
      assert(InstL->getNumOperands() == InstR->getNumOperands());

      for (unsigned i = 0, e = InstL->getNumOperands(); i != e; ++i) {
        Value *OpL = InstL->getOperand(i);
        Value *OpR = InstR->getOperand(i);
        if (int Res = cmpValues(OpL, OpR))
          return Res;
        // cmpValues should ensure this is true.
        assert(cmpTypes(OpL->getType(), OpR->getType()) == 0);
      }
    }

    ++InstL;
    ++InstR;
  } while (InstL != InstLE && InstR != InstRE);

  if (InstL != InstLE && InstR == InstRE)
    return 1;
  if (InstL == InstLE && InstR != InstRE)
    return -1;
  return 0;
}
示例#2
0
static bool equals(const BasicBlock *BB1, const BasicBlock *BB2,
                   DenseMap<const Value *, const Value *> &ValueMap,
                   DenseMap<const Value *, const Value *> &SpeculationMap) {
  // Specutively add it anyways. If it's false, we'll notice a difference later, and
  // this won't matter.
  ValueMap[BB1] = BB2;

  BasicBlock::const_iterator FI = BB1->begin(), FE = BB1->end();
  BasicBlock::const_iterator GI = BB2->begin(), GE = BB2->end();

  do {
    if (!FI->isSameOperationAs(const_cast<Instruction *>(&*GI)))
      return false;

    if (FI->getNumOperands() != GI->getNumOperands())
      return false;

    if (ValueMap[FI] == GI) {
      ++FI, ++GI;
      continue;
    }

    if (ValueMap[FI] != NULL)
      return false;

    for (unsigned i = 0, e = FI->getNumOperands(); i != e; ++i) {
      Value *OpF = FI->getOperand(i);
      Value *OpG = GI->getOperand(i);

      if (ValueMap[OpF] == OpG)
        continue;

      if (ValueMap[OpF] != NULL)
        return false;

      assert(OpF->getType() == OpG->getType() &&
             "Two of the same operation has operands of different type.");

      if (OpF->getValueID() != OpG->getValueID())
        return false;

      if (isa<PHINode>(FI)) {
        if (SpeculationMap[OpF] == NULL)
          SpeculationMap[OpF] = OpG;
        else if (SpeculationMap[OpF] != OpG)
          return false;
        continue;
      } else if (isa<BasicBlock>(OpF)) {
        assert(isa<TerminatorInst>(FI) &&
               "BasicBlock referenced by non-Terminator non-PHI");
        // This call changes the ValueMap, hence we can't use
        // Value *& = ValueMap[...]
        if (!equals(cast<BasicBlock>(OpF), cast<BasicBlock>(OpG), ValueMap,
                    SpeculationMap))
          return false;
      } else {
        if (!compare(OpF, OpG))
          return false;
      }

      ValueMap[OpF] = OpG;
    }

    ValueMap[FI] = GI;
    ++FI, ++GI;
  } while (FI != FE && GI != GE);

  return FI == FE && GI == GE;
}
示例#3
0
static bool equals(const BasicBlock *BB1, const BasicBlock *BB2,
                   DenseMap<const Value *, const Value *> &ValueMap,
                   DenseMap<const Value *, const Value *> &SpeculationMap) {
  // Speculatively add it anyways. If it's false, we'll notice a difference
  // later, and this won't matter.
  ValueMap[BB1] = BB2;

  BasicBlock::const_iterator FI = BB1->begin(), FE = BB1->end();
  BasicBlock::const_iterator GI = BB2->begin(), GE = BB2->end();

  do {
    if (isa<BitCastInst>(FI)) {
      ++FI;
      continue;
    }
    if (isa<BitCastInst>(GI)) {
      ++GI;
      continue;
    }

    if (!isEquivalentOperation(FI, GI))
      return false;

    if (isa<GetElementPtrInst>(FI)) {
      const GetElementPtrInst *GEPF = cast<GetElementPtrInst>(FI);
      const GetElementPtrInst *GEPG = cast<GetElementPtrInst>(GI);
      if (GEPF->hasAllZeroIndices() && GEPG->hasAllZeroIndices()) {
        // It's effectively a bitcast.
        ++FI, ++GI;
        continue;
      }

      // TODO: we only really care about the elements before the index
      if (FI->getOperand(0)->getType() != GI->getOperand(0)->getType())
        return false;
    }

    if (ValueMap[FI] == GI) {
      ++FI, ++GI;
      continue;
    }

    if (ValueMap[FI] != NULL)
      return false;

    for (unsigned i = 0, e = FI->getNumOperands(); i != e; ++i) {
      Value *OpF = IgnoreBitcasts(FI->getOperand(i));
      Value *OpG = IgnoreBitcasts(GI->getOperand(i));

      if (ValueMap[OpF] == OpG)
        continue;

      if (ValueMap[OpF] != NULL)
        return false;

      if (OpF->getValueID() != OpG->getValueID() ||
          !isEquivalentType(OpF->getType(), OpG->getType()))
        return false;

      if (isa<PHINode>(FI)) {
        if (SpeculationMap[OpF] == NULL)
          SpeculationMap[OpF] = OpG;
        else if (SpeculationMap[OpF] != OpG)
          return false;
        continue;
      } else if (isa<BasicBlock>(OpF)) {
        assert(isa<TerminatorInst>(FI) &&
               "BasicBlock referenced by non-Terminator non-PHI");
        // This call changes the ValueMap, hence we can't use
        // Value *& = ValueMap[...]
        if (!equals(cast<BasicBlock>(OpF), cast<BasicBlock>(OpG), ValueMap,
                    SpeculationMap))
          return false;
      } else {
        if (!compare(OpF, OpG))
          return false;
      }

      ValueMap[OpF] = OpG;
    }

    ValueMap[FI] = GI;
    ++FI, ++GI;
  } while (FI != FE && GI != GE);

  return FI == FE && GI == GE;
}