-//===- BranchProbability.h - Branch Probability Analysis --------*- C++ -*-===//
+//===- BranchProbability.h - Branch Probability Wrapper ---------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
#define LLVM_SUPPORT_BRANCHPROBABILITY_H
#include "llvm/Support/DataTypes.h"
+#include <cassert>
namespace llvm {
// This class represents Branch Probability as a non-negative fraction.
class BranchProbability {
-
// Numerator
uint32_t N;
uint32_t D;
public:
- BranchProbability(uint32_t n, uint32_t d);
+ BranchProbability(uint32_t n, uint32_t d) : N(n), D(d) {
+ assert(d > 0 && "Denomiator cannot be 0!");
+ assert(n <= d && "Probability cannot be bigger than 1!");
+ }
+
+ static BranchProbability getZero() { return BranchProbability(0, 1); }
+ static BranchProbability getOne() { return BranchProbability(1, 1); }
uint32_t getNumerator() const { return N; }
uint32_t getDenominator() const { return D; }
-
+
// Return (1 - Probability).
- BranchProbability getCompl() {
+ BranchProbability getCompl() const {
return BranchProbability(D - N, D);
}
raw_ostream &print(raw_ostream &OS) const;
void dump() const;
+
+ /// \brief Scale a large integer.
+ ///
+ /// Scales \c Num. Guarantees full precision. Returns the floor of the
+ /// result.
+ ///
+ /// \return \c Num times \c this.
+ uint64_t scale(uint64_t Num) const;
+
+ /// \brief Scale a large integer by the inverse.
+ ///
+ /// Scales \c Num by the inverse of \c this. Guarantees full precision.
+ /// Returns the floor of the result.
+ ///
+ /// \return \c Num divided by \c this.
+ uint64_t scaleByInverse(uint64_t Num) const;
+
+ bool operator==(BranchProbability RHS) const {
+ return (uint64_t)N * RHS.D == (uint64_t)D * RHS.N;
+ }
+ bool operator!=(BranchProbability RHS) const {
+ return !(*this == RHS);
+ }
+ bool operator<(BranchProbability RHS) const {
+ return (uint64_t)N * RHS.D < (uint64_t)D * 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); }
};
-raw_ostream &operator<<(raw_ostream &OS, const BranchProbability &Prob);
+inline raw_ostream &operator<<(raw_ostream &OS, const BranchProbability &Prob) {
+ return Prob.print(OS);
+}
}