1 //===-- Statistic.cpp - Easy way to expose stats information --------------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file implements the 'Statistic' class, which is designed to be an easy
11 // way to expose various success metrics from passes. These statistics are
12 // printed at the end of a run, when the -stats command line option is enabled
13 // on the command line.
15 // This is useful for reporting information like the number of instructions
16 // simplified, optimized or removed by various transformations, like this:
18 // static Statistic NumInstEliminated("GCSE", "Number of instructions killed");
20 // Later, in the code: ++NumInstEliminated;
22 //===----------------------------------------------------------------------===//
24 #include "llvm/ADT/Statistic.h"
25 #include "llvm/Support/CommandLine.h"
26 #include "llvm/Support/Debug.h"
27 #include "llvm/Support/ManagedStatic.h"
28 #include "llvm/Support/raw_ostream.h"
29 #include "llvm/System/Mutex.h"
30 #include "llvm/ADT/StringExtras.h"
35 // GetLibSupportInfoOutputFile - Return a file stream to print our output on.
36 namespace llvm { extern raw_ostream *GetLibSupportInfoOutputFile(); }
38 /// -stats - Command line option to cause transformations to emit stats about
42 Enabled("stats", cl::desc("Enable statistics output from program"));
46 /// StatisticInfo - This class is used in a ManagedStatic so that it is created
47 /// on demand (when the first statistic is bumped) and destroyed only when
48 /// llvm_shutdown is called. We print statistics from the destructor.
50 std::vector<const Statistic*> Stats;
54 void addStatistic(const Statistic *S) {
60 static ManagedStatic<StatisticInfo> StatInfo;
61 static ManagedStatic<sys::SmartMutex<true> > StatLock;
63 /// RegisterStatistic - The first time a statistic is bumped, this method is
65 void Statistic::RegisterStatistic() {
66 // If stats are enabled, inform StatInfo that this statistic should be
68 sys::SmartScopedLock<true> Writer(*StatLock);
71 StatInfo->addStatistic(this);
74 // Remember we have been registered.
82 bool operator()(const Statistic *LHS, const Statistic *RHS) const {
83 int Cmp = std::strcmp(LHS->getName(), RHS->getName());
84 if (Cmp != 0) return Cmp < 0;
86 // Secondary key is the description.
87 return std::strcmp(LHS->getDesc(), RHS->getDesc()) < 0;
93 // Print information when destroyed, iff command line option is specified.
94 StatisticInfo::~StatisticInfo() {
95 // Statistics not enabled?
96 if (Stats.empty()) return;
98 // Get the stream to write to.
99 raw_ostream &OutStream = *GetLibSupportInfoOutputFile();
101 // Figure out how long the biggest Value and Name fields are.
102 unsigned MaxNameLen = 0, MaxValLen = 0;
103 for (size_t i = 0, e = Stats.size(); i != e; ++i) {
104 MaxValLen = std::max(MaxValLen,
105 (unsigned)utostr(Stats[i]->getValue()).size());
106 MaxNameLen = std::max(MaxNameLen,
107 (unsigned)std::strlen(Stats[i]->getName()));
110 // Sort the fields by name.
111 std::stable_sort(Stats.begin(), Stats.end(), NameCompare());
113 // Print out the statistics header...
114 OutStream << "===" << std::string(73, '-') << "===\n"
115 << " ... Statistics Collected ...\n"
116 << "===" << std::string(73, '-') << "===\n\n";
118 // Print all of the statistics.
119 for (size_t i = 0, e = Stats.size(); i != e; ++i) {
120 std::string CountStr = utostr(Stats[i]->getValue());
121 OutStream << std::string(MaxValLen-CountStr.size(), ' ')
122 << CountStr << " " << Stats[i]->getName()
123 << std::string(MaxNameLen-std::strlen(Stats[i]->getName()), ' ')
124 << " - " << Stats[i]->getDesc() << "\n";
128 OutStream << '\n'; // Flush the output stream...
131 if (&OutStream != &outs() && &OutStream != &errs() && &OutStream != &dbgs())
132 delete &OutStream; // Close the file.