1 //===- BranchProbability.h - Branch Probability Wrapper ---------*- C++ -*-===// 2 // 3 // The LLVM Compiler Infrastructure 4 // 5 // This file is distributed under the University of Illinois Open Source 6 // License. See LICENSE.TXT for details. 7 // 8 //===----------------------------------------------------------------------===// 9 // 10 // Definition of BranchProbability shared by IR and Machine Instructions. 11 // 12 //===----------------------------------------------------------------------===// 13 14 #ifndef LLVM_SUPPORT_BRANCHPROBABILITY_H 15 #define LLVM_SUPPORT_BRANCHPROBABILITY_H 16 17 #include "llvm/Support/DataTypes.h" 18 #include <cassert> 19 20 namespace llvm { 21 22 class raw_ostream; 23 24 // This class represents Branch Probability as a non-negative fraction. 25 class BranchProbability { 26 // Numerator 27 uint32_t N; 28 29 // Denominator 30 uint32_t D; 31 32 public: BranchProbability(uint32_t n,uint32_t d)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!"); 36 } 37 getZero()38 static BranchProbability getZero() { return BranchProbability(0, 1); } getOne()39 static BranchProbability getOne() { return BranchProbability(1, 1); } 40 getNumerator()41 uint32_t getNumerator() const { return N; } getDenominator()42 uint32_t getDenominator() const { return D; } 43 44 // Return (1 - Probability). getCompl()45 BranchProbability getCompl() const { 46 return BranchProbability(D - N, D); 47 } 48 49 void print(raw_ostream &OS) const; 50 51 void dump() const; 52 53 bool operator==(BranchProbability RHS) const { 54 return (uint64_t)N * RHS.D == (uint64_t)D * RHS.N; 55 } 56 bool operator!=(BranchProbability RHS) const { 57 return !(*this == RHS); 58 } 59 bool operator<(BranchProbability RHS) const { 60 return (uint64_t)N * RHS.D < (uint64_t)D * RHS.N; 61 } 62 bool operator>(BranchProbability RHS) const { 63 return RHS < *this; 64 } 65 bool operator<=(BranchProbability RHS) const { 66 return (uint64_t)N * RHS.D <= (uint64_t)D * RHS.N; 67 } 68 bool operator>=(BranchProbability RHS) const { 69 return RHS <= *this; 70 } 71 }; 72 73 raw_ostream &operator<<(raw_ostream &OS, const BranchProbability &Prob); 74 75 } 76 77 #endif 78