LLVM  16.0.0git
Statistic.h
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1 //===-- llvm/ADT/Statistic.h - Easy way to expose stats ---------*- 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 /// \file
10 /// This file defines the 'Statistic' class, which is designed to be an easy way
11 /// to expose various metrics from passes. These statistics are printed at the
12 /// end of a run (from llvm_shutdown), when the -stats command line option is
13 /// passed on the command line.
14 ///
15 /// This is useful for reporting information like the number of instructions
16 /// simplified, optimized or removed by various transformations, like this:
17 ///
18 /// static Statistic NumInstsKilled("gcse", "Number of instructions killed");
19 ///
20 /// Later, in the code: ++NumInstsKilled;
21 ///
22 /// NOTE: Statistics *must* be declared as global variables.
23 ///
24 //===----------------------------------------------------------------------===//
25 
26 #ifndef LLVM_ADT_STATISTIC_H
27 #define LLVM_ADT_STATISTIC_H
28 
29 #include "llvm/Config/llvm-config.h"
30 #include "llvm/Support/Compiler.h"
31 #include <atomic>
32 #include <memory>
33 #include <vector>
34 
35 // Determine whether statistics should be enabled. We must do it here rather
36 // than in CMake because multi-config generators cannot determine this at
37 // configure time.
38 #if !defined(NDEBUG) || LLVM_FORCE_ENABLE_STATS
39 #define LLVM_ENABLE_STATS 1
40 #else
41 #define LLVM_ENABLE_STATS 0
42 #endif
43 
44 namespace llvm {
45 
46 class raw_ostream;
47 class raw_fd_ostream;
48 class StringRef;
49 
51 public:
52  const char *const DebugType;
53  const char *const Name;
54  const char *const Desc;
55 
56  std::atomic<uint64_t> Value;
57  std::atomic<bool> Initialized;
58 
59  constexpr TrackingStatistic(const char *DebugType, const char *Name,
60  const char *Desc)
62  Initialized(false) {}
63 
64  const char *getDebugType() const { return DebugType; }
65  const char *getName() const { return Name; }
66  const char *getDesc() const { return Desc; }
67 
68  uint64_t getValue() const { return Value.load(std::memory_order_relaxed); }
69 
70  // Allow use of this class as the value itself.
71  operator uint64_t() const { return getValue(); }
72 
74  Value.store(Val, std::memory_order_relaxed);
75  return init();
76  }
77 
79  Value.fetch_add(1, std::memory_order_relaxed);
80  return init();
81  }
82 
84  init();
85  return Value.fetch_add(1, std::memory_order_relaxed);
86  }
87 
89  Value.fetch_sub(1, std::memory_order_relaxed);
90  return init();
91  }
92 
94  init();
95  return Value.fetch_sub(1, std::memory_order_relaxed);
96  }
97 
99  if (V == 0)
100  return *this;
101  Value.fetch_add(V, std::memory_order_relaxed);
102  return init();
103  }
104 
106  if (V == 0)
107  return *this;
108  Value.fetch_sub(V, std::memory_order_relaxed);
109  return init();
110  }
111 
112  void updateMax(uint64_t V) {
113  uint64_t PrevMax = Value.load(std::memory_order_relaxed);
114  // Keep trying to update max until we succeed or another thread produces
115  // a bigger max than us.
116  while (V > PrevMax && !Value.compare_exchange_weak(
117  PrevMax, V, std::memory_order_relaxed)) {
118  }
119  init();
120  }
121 
122 protected:
124  if (!Initialized.load(std::memory_order_acquire))
126  return *this;
127  }
128 
129  void RegisterStatistic();
130 };
131 
133 public:
134  NoopStatistic(const char * /*DebugType*/, const char * /*Name*/,
135  const char * /*Desc*/) {}
136 
137  uint64_t getValue() const { return 0; }
138 
139  // Allow use of this class as the value itself.
140  operator uint64_t() const { return 0; }
141 
142  const NoopStatistic &operator=(uint64_t Val) { return *this; }
143 
144  const NoopStatistic &operator++() { return *this; }
145 
146  uint64_t operator++(int) { return 0; }
147 
148  const NoopStatistic &operator--() { return *this; }
149 
150  uint64_t operator--(int) { return 0; }
151 
152  const NoopStatistic &operator+=(const uint64_t &V) { return *this; }
153 
154  const NoopStatistic &operator-=(const uint64_t &V) { return *this; }
155 
156  void updateMax(uint64_t V) {}
157 };
158 
159 #if LLVM_ENABLE_STATS
161 #else
162 using Statistic = NoopStatistic;
163 #endif
164 
165 // STATISTIC - A macro to make definition of statistics really simple. This
166 // automatically passes the DEBUG_TYPE of the file into the statistic.
167 #define STATISTIC(VARNAME, DESC) \
168  static llvm::Statistic VARNAME = {DEBUG_TYPE, #VARNAME, DESC}
169 
170 // ALWAYS_ENABLED_STATISTIC - A macro to define a statistic like STATISTIC but
171 // it is enabled even if LLVM_ENABLE_STATS is off.
172 #define ALWAYS_ENABLED_STATISTIC(VARNAME, DESC) \
173  static llvm::TrackingStatistic VARNAME = {DEBUG_TYPE, #VARNAME, DESC}
174 
175 /// Enable the collection and printing of statistics.
176 void EnableStatistics(bool DoPrintOnExit = true);
177 
178 /// Check if statistics are enabled.
179 bool AreStatisticsEnabled();
180 
181 /// Return a file stream to print our output on.
182 std::unique_ptr<raw_fd_ostream> CreateInfoOutputFile();
183 
184 /// Print statistics to the file returned by CreateInfoOutputFile().
185 void PrintStatistics();
186 
187 /// Print statistics to the given output stream.
188 void PrintStatistics(raw_ostream &OS);
189 
190 /// Print statistics in JSON format. This does include all global timers (\see
191 /// Timer, TimerGroup). Note that the timers are cleared after printing and will
192 /// not be printed in human readable form or in a second call of
193 /// PrintStatisticsJSON().
194 void PrintStatisticsJSON(raw_ostream &OS);
195 
196 /// Get the statistics. This can be used to look up the value of
197 /// statistics without needing to parse JSON.
198 ///
199 /// This function does not prevent statistics being updated by other threads
200 /// during it's execution. It will return the value at the point that it is
201 /// read. However, it will prevent new statistics from registering until it
202 /// completes.
203 std::vector<std::pair<StringRef, uint64_t>> GetStatistics();
204 
205 /// Reset the statistics. This can be used to zero and de-register the
206 /// statistics in order to measure a compilation.
207 ///
208 /// When this function begins to call destructors prior to returning, all
209 /// statistics will be zero and unregistered. However, that might not remain the
210 /// case by the time this function finishes returning. Whether update from other
211 /// threads are lost or merely deferred until during the function return is
212 /// timing sensitive.
213 ///
214 /// Callers who intend to use this to measure statistics for a single
215 /// compilation should ensure that no compilations are in progress at the point
216 /// this function is called and that only one compilation executes until calling
217 /// GetStatistics().
218 void ResetStatistics();
219 
220 } // end namespace llvm
221 
222 #endif // LLVM_ADT_STATISTIC_H
llvm::TrackingStatistic::Value
std::atomic< uint64_t > Value
Definition: Statistic.h:56
llvm
This is an optimization pass for GlobalISel generic memory operations.
Definition: AddressRanges.h:18
llvm::TrackingStatistic::operator=
const TrackingStatistic & operator=(uint64_t Val)
Definition: Statistic.h:73
llvm::TrackingStatistic::operator--
uint64_t operator--(int)
Definition: Statistic.h:93
llvm::TrackingStatistic::getDebugType
const char * getDebugType() const
Definition: Statistic.h:64
llvm::NoopStatistic::NoopStatistic
NoopStatistic(const char *, const char *, const char *)
Definition: Statistic.h:134
llvm::CreateInfoOutputFile
std::unique_ptr< raw_fd_ostream > CreateInfoOutputFile()
Return a file stream to print our output on.
Definition: Timer.cpp:96
llvm::TrackingStatistic::operator++
uint64_t operator++(int)
Definition: Statistic.h:83
llvm::NoopStatistic::operator--
uint64_t operator--(int)
Definition: Statistic.h:150
llvm::AreStatisticsEnabled
bool AreStatisticsEnabled()
Check if statistics are enabled.
Definition: Statistic.cpp:139
llvm::TrackingStatistic::RegisterStatistic
void RegisterStatistic()
RegisterStatistic - The first time a statistic is bumped, this method is called.
Definition: Statistic.cpp:98
llvm::NoopStatistic
Definition: Statistic.h:132
false
Definition: StackSlotColoring.cpp:141
llvm::TrackingStatistic::operator--
const TrackingStatistic & operator--()
Definition: Statistic.h:88
llvm::TrackingStatistic::getName
const char * getName() const
Definition: Statistic.h:65
llvm::TrackingStatistic::DebugType
const char *const DebugType
Definition: Statistic.h:52
llvm::TrackingStatistic::getDesc
const char * getDesc() const
Definition: Statistic.h:66
llvm::PrintStatisticsJSON
void PrintStatisticsJSON(raw_ostream &OS)
Print statistics in JSON format.
Definition: Statistic.cpp:203
llvm::NoopStatistic::getValue
uint64_t getValue() const
Definition: Statistic.h:137
llvm::TrackingStatistic::getValue
uint64_t getValue() const
Definition: Statistic.h:68
uint64_t
llvm::NoopStatistic::operator=
const NoopStatistic & operator=(uint64_t Val)
Definition: Statistic.h:142
llvm::TrackingStatistic::init
TrackingStatistic & init()
Definition: Statistic.h:123
llvm::EnableStatistics
void EnableStatistics(bool DoPrintOnExit=true)
Enable the collection and printing of statistics.
Definition: Statistic.cpp:134
llvm::TrackingStatistic::TrackingStatistic
constexpr TrackingStatistic(const char *DebugType, const char *Name, const char *Desc)
Definition: Statistic.h:59
llvm::TrackingStatistic::updateMax
void updateMax(uint64_t V)
Definition: Statistic.h:112
llvm::PrintStatistics
void PrintStatistics()
Print statistics to the file returned by CreateInfoOutputFile().
Definition: Statistic.cpp:229
llvm::TrackingStatistic::Name
const char *const Name
Definition: Statistic.h:53
Compiler.h
llvm::TrackingStatistic
Definition: Statistic.h:50
llvm::TrackingStatistic::operator-=
const TrackingStatistic & operator-=(uint64_t V)
Definition: Statistic.h:105
llvm::TrackingStatistic::operator+=
const TrackingStatistic & operator+=(uint64_t V)
Definition: Statistic.h:98
llvm::NoopStatistic::operator++
const NoopStatistic & operator++()
Definition: Statistic.h:144
llvm::TrackingStatistic::Desc
const char *const Desc
Definition: Statistic.h:54
llvm::TrackingStatistic::Initialized
std::atomic< bool > Initialized
Definition: Statistic.h:57
llvm::ResetStatistics
void ResetStatistics()
Reset the statistics.
Definition: Statistic.cpp:266
llvm::NoopStatistic::updateMax
void updateMax(uint64_t V)
Definition: Statistic.h:156
llvm::NoopStatistic::operator+=
const NoopStatistic & operator+=(const uint64_t &V)
Definition: Statistic.h:152
llvm::NoopStatistic::operator-=
const NoopStatistic & operator-=(const uint64_t &V)
Definition: Statistic.h:154
llvm::NoopStatistic::operator--
const NoopStatistic & operator--()
Definition: Statistic.h:148
llvm::GetStatistics
std::vector< std::pair< StringRef, uint64_t > > GetStatistics()
Get the statistics.
Definition: Statistic.cpp:257
llvm::Value
LLVM Value Representation.
Definition: Value.h:74
llvm::TrackingStatistic::operator++
const TrackingStatistic & operator++()
Definition: Statistic.h:78
llvm::NoopStatistic::operator++
uint64_t operator++(int)
Definition: Statistic.h:146