Esempio n. 1
0
void TestInstVisitor::visitSwitchInst(SwitchInst &I){
    if (except){
        return;
    }

    DynValEntry entry;
    size_t n = fread(&entry, sizeof(DynValEntry), 1, dlog);
    if (entry.entrytype == EXCEPTIONENTRY){
        except = true;
        return;
    }
    assert(entry.entrytype == SWITCHENTRY);
    //printf("switch %d\n", entry.entry.switchstmt.cond);
    IntegerType *intType = IntegerType::get(getGlobalContext(), sizeof(int)*8);
    ConstantInt *caseVal =
        ConstantInt::get(intType, entry.entry.switchstmt.cond);
    SwitchInst::CaseIt caseIndex = I.findCaseValue(caseVal);
    TFP->setNextBB(I.getSuccessor(caseIndex.getSuccessorIndex()));
}
Esempio n. 2
0
/// getFeasibleSuccessors - Return a vector of booleans to indicate which
/// successors are reachable from a given terminator instruction.
void SparseSolver::getFeasibleSuccessors(TerminatorInst &TI,
                                         SmallVectorImpl<bool> &Succs,
                                         bool AggressiveUndef) {
  Succs.resize(TI.getNumSuccessors());
  if (TI.getNumSuccessors() == 0) return;

  if (BranchInst *BI = dyn_cast<BranchInst>(&TI)) {
    if (BI->isUnconditional()) {
      Succs[0] = true;
      return;
    }

    LatticeVal BCValue;
    if (AggressiveUndef)
      BCValue = getOrInitValueState(BI->getCondition());
    else
      BCValue = getLatticeState(BI->getCondition());

    if (BCValue == LatticeFunc->getOverdefinedVal() ||
        BCValue == LatticeFunc->getUntrackedVal()) {
      // Overdefined condition variables can branch either way.
      Succs[0] = Succs[1] = true;
      return;
    }

    // If undefined, neither is feasible yet.
    if (BCValue == LatticeFunc->getUndefVal())
      return;

    Constant *C = LatticeFunc->GetConstant(BCValue, BI->getCondition(), *this);
    if (C == 0 || !isa<ConstantInt>(C)) {
      // Non-constant values can go either way.
      Succs[0] = Succs[1] = true;
      return;
    }

    // Constant condition variables mean the branch can only go a single way
    Succs[C->isNullValue()] = true;
    return;
  }

  if (isa<InvokeInst>(TI)) {
    // Invoke instructions successors are always executable.
    // TODO: Could ask the lattice function if the value can throw.
    Succs[0] = Succs[1] = true;
    return;
  }

  if (isa<IndirectBrInst>(TI)) {
    Succs.assign(Succs.size(), true);
    return;
  }

  SwitchInst &SI = cast<SwitchInst>(TI);
  LatticeVal SCValue;
  if (AggressiveUndef)
    SCValue = getOrInitValueState(SI.getCondition());
  else
    SCValue = getLatticeState(SI.getCondition());

  if (SCValue == LatticeFunc->getOverdefinedVal() ||
      SCValue == LatticeFunc->getUntrackedVal()) {
    // All destinations are executable!
    Succs.assign(TI.getNumSuccessors(), true);
    return;
  }

  // If undefined, neither is feasible yet.
  if (SCValue == LatticeFunc->getUndefVal())
    return;

  Constant *C = LatticeFunc->GetConstant(SCValue, SI.getCondition(), *this);
  if (C == 0 || !isa<ConstantInt>(C)) {
    // All destinations are executable!
    Succs.assign(TI.getNumSuccessors(), true);
    return;
  }
  SwitchInst::CaseIt Case = SI.findCaseValue(cast<ConstantInt>(C));
  Succs[Case.getSuccessorIndex()] = true;
}