aboutsummaryrefslogtreecommitdiff
path: root/include/llvm/ADT/Statistic.h
blob: b54d10b9dd334d0317054f81c82c3504a3517007 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
//===-- llvm/ADT/Statistic.h - Easy way to expose stats ---------*- C++ -*-===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file defines the 'Statistic' class, which is designed to be an easy way
// to expose various metrics from passes.  These statistics are printed at the
// end of a run (from llvm_shutdown), when the -stats command line option is
// passed on the command line.
//
// This is useful for reporting information like the number of instructions
// simplified, optimized or removed by various transformations, like this:
//
// static Statistic NumInstsKilled("gcse", "Number of instructions killed");
//
// Later, in the code: ++NumInstsKilled;
//
// NOTE: Statistics *must* be declared as global variables.
//
//===----------------------------------------------------------------------===//

#ifndef LLVM_ADT_STATISTIC_H
#define LLVM_ADT_STATISTIC_H

#include "llvm/Support/Atomic.h"
#include "llvm/Support/Valgrind.h"

namespace llvm {
class raw_ostream;

class Statistic {
public:
  const char *Name;
  const char *Desc;
  volatile llvm::sys::cas_flag Value;
  bool Initialized;

  llvm::sys::cas_flag getValue() const { return Value; }
  const char *getName() const { return Name; }
  const char *getDesc() const { return Desc; }

  /// construct - This should only be called for non-global statistics.
  void construct(const char *name, const char *desc) {
    Name = name; Desc = desc;
    Value = 0; Initialized = 0;
  }

  // Allow use of this class as the value itself.
  operator unsigned() const { return Value; }
  const Statistic &operator=(unsigned Val) {
    Value = Val;
    return init();
  }

  const Statistic &operator++() {
    // FIXME: This function and all those that follow carefully use an
    // atomic operation to update the value safely in the presence of
    // concurrent accesses, but not to read the return value, so the
    // return value is not thread safe.
    sys::AtomicIncrement(&Value);
    return init();
  }

  unsigned operator++(int) {
    init();
    unsigned OldValue = Value;
    sys::AtomicIncrement(&Value);
    return OldValue;
  }

  const Statistic &operator--() {
    sys::AtomicDecrement(&Value);
    return init();
  }

  unsigned operator--(int) {
    init();
    unsigned OldValue = Value;
    sys::AtomicDecrement(&Value);
    return OldValue;
  }

  const Statistic &operator+=(const unsigned &V) {
    if (!V) return *this;
    sys::AtomicAdd(&Value, V);
    return init();
  }

  const Statistic &operator-=(const unsigned &V) {
    if (!V) return *this;
    sys::AtomicAdd(&Value, -V);
    return init();
  }

  const Statistic &operator*=(const unsigned &V) {
    sys::AtomicMul(&Value, V);
    return init();
  }

  const Statistic &operator/=(const unsigned &V) {
    sys::AtomicDiv(&Value, V);
    return init();
  }

protected:
  Statistic &init() {
    bool tmp = Initialized;
    sys::MemoryFence();
    if (!tmp) RegisterStatistic();
    TsanHappensAfter(this);
    return *this;
  }
  void RegisterStatistic();
};

// STATISTIC - A macro to make definition of statistics really simple.  This
// automatically passes the DEBUG_TYPE of the file into the statistic.
#define STATISTIC(VARNAME, DESC) \
  static llvm::Statistic VARNAME = { DEBUG_TYPE, DESC, 0, 0 }

/// \brief Enable the collection and printing of statistics.
void EnableStatistics();

/// \brief Check if statistics are enabled.
bool AreStatisticsEnabled();

/// \brief Print statistics to the file returned by CreateInfoOutputFile().
void PrintStatistics();

/// \brief Print statistics to the given output stream.
void PrintStatistics(raw_ostream &OS);

} // End llvm namespace

#endif