1 //====--------------- lib/Support/BlockFrequency.cpp -----------*- C++ -*-====// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 // 9 // This file implements Block Frequency class. 10 // 11 //===----------------------------------------------------------------------===// 12 13 #include "llvm/Support/BlockFrequency.h" 14 #include <cassert> 15 16 using namespace llvm; 17 18 BlockFrequency &BlockFrequency::operator*=(BranchProbability Prob) { 19 Frequency = Prob.scale(Frequency); 20 return *this; 21 } 22 23 BlockFrequency BlockFrequency::operator*(BranchProbability Prob) const { 24 BlockFrequency Freq(Frequency); 25 Freq *= Prob; 26 return Freq; 27 } 28 29 BlockFrequency &BlockFrequency::operator/=(BranchProbability Prob) { 30 Frequency = Prob.scaleByInverse(Frequency); 31 return *this; 32 } 33 34 BlockFrequency BlockFrequency::operator/(BranchProbability Prob) const { 35 BlockFrequency Freq(Frequency); 36 Freq /= Prob; 37 return Freq; 38 } 39 40 BlockFrequency &BlockFrequency::operator+=(BlockFrequency Freq) { 41 uint64_t Before = Freq.Frequency; 42 Frequency += Freq.Frequency; 43 44 // If overflow, set frequency to the maximum value. 45 if (Frequency < Before) 46 Frequency = UINT64_MAX; 47 48 return *this; 49 } 50 51 BlockFrequency BlockFrequency::operator+(BlockFrequency Freq) const { 52 BlockFrequency NewFreq(Frequency); 53 NewFreq += Freq; 54 return NewFreq; 55 } 56 57 BlockFrequency &BlockFrequency::operator-=(BlockFrequency Freq) { 58 // If underflow, set frequency to 0. 59 if (Frequency <= Freq.Frequency) 60 Frequency = 0; 61 else 62 Frequency -= Freq.Frequency; 63 return *this; 64 } 65 66 BlockFrequency BlockFrequency::operator-(BlockFrequency Freq) const { 67 BlockFrequency NewFreq(Frequency); 68 NewFreq -= Freq; 69 return NewFreq; 70 } 71 72 BlockFrequency &BlockFrequency::operator>>=(const unsigned count) { 73 // Frequency can never be 0 by design. 74 assert(Frequency != 0); 75 76 // Shift right by count. 77 Frequency >>= count; 78 79 // Saturate to 1 if we are 0. 80 Frequency |= Frequency == 0; 81 return *this; 82 } 83