Esempi in C++ (Cpp) per FCmpInst::isTrueWhenEqual

Esempio n. 1

bool BranchProbabilityInfo::calcFloatingPointHeuristics(BasicBlock *BB) {
  BranchInst *BI = dyn_cast<BranchInst>(BB->getTerminator());
  if (!BI || !BI->isConditional())
    return false;

  Value *Cond = BI->getCondition();
  FCmpInst *FCmp = dyn_cast<FCmpInst>(Cond);
  if (!FCmp)
    return false;

  bool isProb;
  if (FCmp->isEquality()) {
    // f1 == f2 -> Unlikely
    // f1 != f2 -> Likely
    isProb = !FCmp->isTrueWhenEqual();
  } else if (FCmp->getPredicate() == FCmpInst::FCMP_ORD) {
    // !isnan -> Likely
    isProb = true;
  } else if (FCmp->getPredicate() == FCmpInst::FCMP_UNO) {
    // isnan -> Unlikely
    isProb = false;
  } else {
    return false;
  }

  unsigned TakenIdx = 0, NonTakenIdx = 1;

  if (!isProb)
    std::swap(TakenIdx, NonTakenIdx);

  setEdgeWeight(BB, TakenIdx, FPH_TAKEN_WEIGHT);
  setEdgeWeight(BB, NonTakenIdx, FPH_NONTAKEN_WEIGHT);

  return true;
}