// Create a BranchProbability object with the given numerator and 1<<31
// as denominator.
static BranchProbability getRaw(uint32_t N) { return BranchProbability(N); }
+ // Create a BranchProbability object from 64-bit integers.
+ static BranchProbability getBranchProbability(uint64_t Numerator,
+ uint64_t Denominator);
// Normalize given probabilties so that the sum of them becomes approximate
// one.
return *this;
}
+ BranchProbability &operator/=(uint32_t RHS) {
+ assert(N != UnknownN &&
+ "Unknown probability cannot participate in arithmetics.");
+ assert(RHS > 0 && "The divider cannot be zero.");
+ N /= RHS;
+ return *this;
+ }
+
BranchProbability operator+(BranchProbability RHS) const {
BranchProbability Prob(*this);
return Prob += RHS;
return Prob *= RHS;
}
+ BranchProbability operator/(uint32_t RHS) const {
+ BranchProbability Prob(*this);
+ return Prob /= RHS;
+ }
+
bool operator==(BranchProbability RHS) const { return N == RHS.N; }
bool operator!=(BranchProbability RHS) const { return !(*this == RHS); }
- bool operator<(BranchProbability RHS) const { return N < RHS.N; }
- bool operator>(BranchProbability RHS) const { return RHS < *this; }
- bool operator<=(BranchProbability RHS) const { return !(RHS < *this); }
- bool operator>=(BranchProbability RHS) const { return !(*this < RHS); }
+
+ bool operator<(BranchProbability RHS) const {
+ assert(N != UnknownN && RHS.N != UnknownN &&
+ "Unknown probability cannot participate in comparisons.");
+ return N < RHS.N;
+ }
+
+ bool operator>(BranchProbability RHS) const {
+ assert(N != UnknownN && RHS.N != UnknownN &&
+ "Unknown probability cannot participate in comparisons.");
+ return RHS < *this;
+ }
+
+ bool operator<=(BranchProbability RHS) const {
+ assert(N != UnknownN && RHS.N != UnknownN &&
+ "Unknown probability cannot participate in comparisons.");
+ return !(RHS < *this);
+ }
+
+ bool operator>=(BranchProbability RHS) const {
+ assert(N != UnknownN && RHS.N != UnknownN &&
+ "Unknown probability cannot participate in comparisons.");
+ return !(*this < RHS);
+ }
};
inline raw_ostream &operator<<(raw_ostream &OS, BranchProbability Prob) {
return Prob.print(OS);
}
-inline BranchProbability operator/(BranchProbability LHS, uint32_t RHS) {
- assert(LHS != BranchProbability::getUnknown() &&
- "Unknown probability cannot participate in arithmetics.");
- return BranchProbability::getRaw(LHS.getNumerator() / RHS);
-}
-
template <class ProbabilityIter>
void BranchProbability::normalizeProbabilities(ProbabilityIter Begin,
ProbabilityIter End) {
if (Begin == End)
return;
- auto UnknownProbCount =
- std::count(Begin, End, BranchProbability::getUnknown());
- assert((UnknownProbCount == 0 ||
- UnknownProbCount == std::distance(Begin, End)) &&
- "Cannot normalize probabilities with known and unknown ones.");
- (void)UnknownProbCount;
-
- uint64_t Sum = std::accumulate(
- Begin, End, uint64_t(0),
- [](uint64_t S, const BranchProbability &BP) { return S + BP.N; });
-
+ unsigned UnknownProbCount = 0;
+ uint64_t Sum = std::accumulate(Begin, End, uint64_t(0),
+ [&](uint64_t S, const BranchProbability &BP) {
+ if (!BP.isUnknown())
+ return S + BP.N;
+ UnknownProbCount++;
+ return S;
+ });
+
+ if (UnknownProbCount > 0) {
+ BranchProbability ProbForUnknown = BranchProbability::getZero();
+ // If the sum of all known probabilities is less than one, evenly distribute
+ // the complement of sum to unknown probabilities. Otherwise, set unknown
+ // probabilities to zeros and continue to normalize known probabilities.
+ if (Sum < BranchProbability::getDenominator())
+ ProbForUnknown = BranchProbability::getRaw(
+ (BranchProbability::getDenominator() - Sum) / UnknownProbCount);
+
+ std::replace_if(Begin, End,
+ [](const BranchProbability &BP) { return BP.isUnknown(); },
+ ProbForUnknown);
+
+ if (Sum <= BranchProbability::getDenominator())
+ return;
+ }
+
if (Sum == 0) {
BranchProbability BP(1, std::distance(Begin, End));
std::fill(Begin, End, BP);