LLVM  3.7.0
BlockFrequency.h
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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.
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.
41  const BlockFrequency operator*(const BranchProbability &Prob) const;
42 
43  /// \brief Divide by a non-zero branch probability using saturating
44  /// arithmetic.
46  BlockFrequency operator/(const BranchProbability &Prob) const;
47 
48  /// \brief Adds another block frequency using saturating arithmetic.
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
bool operator>=(const BlockFrequency &RHS) const
bool operator<=(const BlockFrequency &RHS) const
BlockFrequency & operator+=(const BlockFrequency &Freq)
Adds another block frequency using saturating arithmetic.
uint64_t getFrequency() const
Returns the frequency as a fixpoint number scaled by the entry frequency.
BlockFrequency & operator/=(const BranchProbability &Prob)
Divide by a non-zero branch probability using saturating arithmetic.
BlockFrequency(uint64_t Freq=0)
const BlockFrequency operator+(const BlockFrequency &Freq) const
const BlockFrequency operator*(const BranchProbability &Prob) const
bool operator>(const BlockFrequency &RHS) const
BlockFrequency & operator*=(const BranchProbability &Prob)
Multiplies with a branch probability.
BlockFrequency operator/(const BranchProbability &Prob) const
bool operator<(const BlockFrequency &RHS) const
static uint64_t getMaxFrequency()
Returns the maximum possible frequency, the saturation value.
BlockFrequency & operator>>=(const unsigned count)
Shift block frequency to the right by count digits saturating to 1.