1 //===- BranchProbability.h - Branch Probability Wrapper ---------*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // Definition of BranchProbability shared by IR and Machine Instructions.
12 //===----------------------------------------------------------------------===//
14 #ifndef LLVM_SUPPORT_BRANCHPROBABILITY_H
15 #define LLVM_SUPPORT_BRANCHPROBABILITY_H
17 #include "llvm/Support/DataTypes.h"
24 // This class represents Branch Probability as a non-negative fraction.
25 class BranchProbability {
33 BranchProbability(uint32_t n, uint32_t d) : N(n), D(d) {
34 assert(d > 0 && "Denomiator cannot be 0!");
35 assert(n <= d && "Probability cannot be bigger than 1!");
38 static BranchProbability getZero() { return BranchProbability(0, 1); }
39 static BranchProbability getOne() { return BranchProbability(1, 1); }
41 uint32_t getNumerator() const { return N; }
42 uint32_t getDenominator() const { return D; }
44 // Return (1 - Probability).
45 BranchProbability getCompl() const {
46 return BranchProbability(D - N, D);
49 void print(raw_ostream &OS) const;
53 bool operator==(BranchProbability RHS) const {
54 return (uint64_t)N * RHS.D == (uint64_t)D * RHS.N;
56 bool operator!=(BranchProbability RHS) const {
57 return !(*this == RHS);
59 bool operator<(BranchProbability RHS) const {
60 return (uint64_t)N * RHS.D < (uint64_t)D * RHS.N;
62 bool operator>(BranchProbability RHS) const {
65 bool operator<=(BranchProbability RHS) const {
66 return (uint64_t)N * RHS.D <= (uint64_t)D * RHS.N;
68 bool operator>=(BranchProbability RHS) const {
73 raw_ostream &operator<<(raw_ostream &OS, const BranchProbability &Prob);