xref: /aosp_15_r20/external/llvm/lib/Support/BlockFrequency.cpp (revision 9880d6810fe72a1726cb53787c6711e909410d58)
1  //====--------------- lib/Support/BlockFrequency.cpp -----------*- 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  #include "llvm/Support/BlockFrequency.h"
15  #include "llvm/Support/raw_ostream.h"
16  #include <cassert>
17  
18  using namespace llvm;
19  
operator *=(BranchProbability Prob)20  BlockFrequency &BlockFrequency::operator*=(BranchProbability Prob) {
21    Frequency = Prob.scale(Frequency);
22    return *this;
23  }
24  
operator *(BranchProbability Prob) const25  BlockFrequency BlockFrequency::operator*(BranchProbability Prob) const {
26    BlockFrequency Freq(Frequency);
27    Freq *= Prob;
28    return Freq;
29  }
30  
operator /=(BranchProbability Prob)31  BlockFrequency &BlockFrequency::operator/=(BranchProbability Prob) {
32    Frequency = Prob.scaleByInverse(Frequency);
33    return *this;
34  }
35  
operator /(BranchProbability Prob) const36  BlockFrequency BlockFrequency::operator/(BranchProbability Prob) const {
37    BlockFrequency Freq(Frequency);
38    Freq /= Prob;
39    return Freq;
40  }
41  
operator +=(BlockFrequency Freq)42  BlockFrequency &BlockFrequency::operator+=(BlockFrequency Freq) {
43    uint64_t Before = Freq.Frequency;
44    Frequency += Freq.Frequency;
45  
46    // If overflow, set frequency to the maximum value.
47    if (Frequency < Before)
48      Frequency = UINT64_MAX;
49  
50    return *this;
51  }
52  
operator +(BlockFrequency Freq) const53  BlockFrequency BlockFrequency::operator+(BlockFrequency Freq) const {
54    BlockFrequency NewFreq(Frequency);
55    NewFreq += Freq;
56    return NewFreq;
57  }
58  
operator -=(BlockFrequency Freq)59  BlockFrequency &BlockFrequency::operator-=(BlockFrequency Freq) {
60    // If underflow, set frequency to 0.
61    if (Frequency <= Freq.Frequency)
62      Frequency = 0;
63    else
64      Frequency -= Freq.Frequency;
65    return *this;
66  }
67  
operator -(BlockFrequency Freq) const68  BlockFrequency BlockFrequency::operator-(BlockFrequency Freq) const {
69    BlockFrequency NewFreq(Frequency);
70    NewFreq -= Freq;
71    return NewFreq;
72  }
73  
operator >>=(const unsigned count)74  BlockFrequency &BlockFrequency::operator>>=(const unsigned count) {
75    // Frequency can never be 0 by design.
76    assert(Frequency != 0);
77  
78    // Shift right by count.
79    Frequency >>= count;
80  
81    // Saturate to 1 if we are 0.
82    Frequency |= Frequency == 0;
83    return *this;
84  }
85