1 //===-------- BlockFrequency.h - Block Frequency 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 // This file implements Block Frequency class. 11 // 12 //===----------------------------------------------------------------------===// 13 14 #ifndef LLVM_SUPPORT_BLOCKFREQUENCY_H 15 #define LLVM_SUPPORT_BLOCKFREQUENCY_H 16 17 #include "llvm/Support/DataTypes.h" 18 19 namespace llvm { 20 21 class raw_ostream; 22 class BranchProbability; 23 24 // This class represents Block Frequency as a 64-bit value. 25 class BlockFrequency { 26 uint64_t Frequency; 27 28 public: 29 BlockFrequency(uint64_t Freq = 0) : Frequency(Freq) { } 30 31 /// \brief Returns the maximum possible frequency, the saturation value. 32 static uint64_t getMaxFrequency() { return -1ULL; } 33 34 /// \brief Returns the frequency as a fixpoint number scaled by the entry 35 /// frequency. 36 uint64_t getFrequency() const { return Frequency; } 37 38 /// \brief Multiplies with a branch probability. The computation will never 39 /// overflow. 40 BlockFrequency &operator*=(const BranchProbability &Prob); 41 const BlockFrequency operator*(const BranchProbability &Prob) const; 42 43 /// \brief Divide by a non-zero branch probability using saturating 44 /// arithmetic. 45 BlockFrequency &operator/=(const BranchProbability &Prob); 46 BlockFrequency operator/(const BranchProbability &Prob) const; 47 48 /// \brief Adds another block frequency using saturating arithmetic. 49 BlockFrequency &operator+=(const BlockFrequency &Freq); 50 const BlockFrequency operator+(const BlockFrequency &Freq) const; 51 52 /// \brief Shift block frequency to the right by count digits saturating to 1. 53 BlockFrequency &operator>>=(const unsigned count); 54 55 bool operator<(const BlockFrequency &RHS) const { 56 return Frequency < RHS.Frequency; 57 } 58 59 bool operator<=(const BlockFrequency &RHS) const { 60 return Frequency <= RHS.Frequency; 61 } 62 63 bool operator>(const BlockFrequency &RHS) const { 64 return Frequency > RHS.Frequency; 65 } 66 67 bool operator>=(const BlockFrequency &RHS) const { 68 return Frequency >= RHS.Frequency; 69 } 70 }; 71 72 } 73 74 #endif 75
