Statistic.cpp revision 193323
1//===-- Statistic.cpp - Easy way to expose stats information --------------===// 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 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. 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 NumInstEliminated("GCSE", "Number of instructions killed"); 19// 20// Later, in the code: ++NumInstEliminated; 21// 22//===----------------------------------------------------------------------===// 23 24#include "llvm/ADT/Statistic.h" 25#include "llvm/Support/CommandLine.h" 26#include "llvm/Support/ManagedStatic.h" 27#include "llvm/Support/Streams.h" 28#include "llvm/ADT/StringExtras.h" 29#include <algorithm> 30#include <ostream> 31#include <cstring> 32using namespace llvm; 33 34// GetLibSupportInfoOutputFile - Return a file stream to print our output on. 35namespace llvm { extern std::ostream *GetLibSupportInfoOutputFile(); } 36 37/// -stats - Command line option to cause transformations to emit stats about 38/// what they did. 39/// 40static cl::opt<bool> 41Enabled("stats", cl::desc("Enable statistics output from program")); 42 43 44namespace { 45/// StatisticInfo - This class is used in a ManagedStatic so that it is created 46/// on demand (when the first statistic is bumped) and destroyed only when 47/// llvm_shutdown is called. We print statistics from the destructor. 48class StatisticInfo { 49 std::vector<const Statistic*> Stats; 50public: 51 ~StatisticInfo(); 52 53 void addStatistic(const Statistic *S) { 54 Stats.push_back(S); 55 } 56}; 57} 58 59static ManagedStatic<StatisticInfo> StatInfo; 60 61 62/// RegisterStatistic - The first time a statistic is bumped, this method is 63/// called. 64void Statistic::RegisterStatistic() { 65 // If stats are enabled, inform StatInfo that this statistic should be 66 // printed. 67 if (Enabled) 68 StatInfo->addStatistic(this); 69 // Remember we have been registered. 70 Initialized = true; 71} 72 73namespace { 74 75struct NameCompare { 76 bool operator()(const Statistic *LHS, const Statistic *RHS) const { 77 int Cmp = std::strcmp(LHS->getName(), RHS->getName()); 78 if (Cmp != 0) return Cmp < 0; 79 80 // Secondary key is the description. 81 return std::strcmp(LHS->getDesc(), RHS->getDesc()) < 0; 82 } 83}; 84 85} 86 87// Print information when destroyed, iff command line option is specified. 88StatisticInfo::~StatisticInfo() { 89 // Statistics not enabled? 90 if (Stats.empty()) return; 91 92 // Get the stream to write to. 93 std::ostream &OutStream = *GetLibSupportInfoOutputFile(); 94 95 // Figure out how long the biggest Value and Name fields are. 96 unsigned MaxNameLen = 0, MaxValLen = 0; 97 for (size_t i = 0, e = Stats.size(); i != e; ++i) { 98 MaxValLen = std::max(MaxValLen, 99 (unsigned)utostr(Stats[i]->getValue()).size()); 100 MaxNameLen = std::max(MaxNameLen, 101 (unsigned)std::strlen(Stats[i]->getName())); 102 } 103 104 // Sort the fields by name. 105 std::stable_sort(Stats.begin(), Stats.end(), NameCompare()); 106 107 // Print out the statistics header... 108 OutStream << "===" << std::string(73, '-') << "===\n" 109 << " ... Statistics Collected ...\n" 110 << "===" << std::string(73, '-') << "===\n\n"; 111 112 // Print all of the statistics. 113 for (size_t i = 0, e = Stats.size(); i != e; ++i) { 114 std::string CountStr = utostr(Stats[i]->getValue()); 115 OutStream << std::string(MaxValLen-CountStr.size(), ' ') 116 << CountStr << " " << Stats[i]->getName() 117 << std::string(MaxNameLen-std::strlen(Stats[i]->getName()), ' ') 118 << " - " << Stats[i]->getDesc() << "\n"; 119 120 } 121 122 OutStream << std::endl; // Flush the output stream... 123 124 if (&OutStream != cerr.stream() && &OutStream != cout.stream()) 125 delete &OutStream; // Close the file. 126} 127