llvm-6502/lib/Support/Statistic.cpp

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//===-- Statistic.cpp - Easy way to expose stats information --------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file implements the 'Statistic' class, which is designed to be an easy
// way to expose various success metrics from passes. These statistics are
// printed at the end of a run, when the -stats command line option is enabled
// 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 NumInstEliminated("GCSE", "Number of instructions killed");
//
// Later, in the code: ++NumInstEliminated;
//
//===----------------------------------------------------------------------===//
#include "llvm/ADT/Statistic.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/ManagedStatic.h"
#include "llvm/Support/Streams.h"
#include "llvm/ADT/StringExtras.h"
#include <algorithm>
#include <ostream>
#include <cstring>
using namespace llvm;
// GetLibSupportInfoOutputFile - Return a file stream to print our output on.
namespace llvm { extern std::ostream *GetLibSupportInfoOutputFile(); }
/// -stats - Command line option to cause transformations to emit stats about
/// what they did.
///
static cl::opt<bool>
Enabled("stats", cl::desc("Enable statistics output from program"));
namespace {
/// StatisticInfo - This class is used in a ManagedStatic so that it is created
/// on demand (when the first statistic is bumped) and destroyed only when
/// llvm_shutdown is called. We print statistics from the destructor.
class StatisticInfo {
std::vector<const Statistic*> Stats;
public:
~StatisticInfo();
void addStatistic(const Statistic *S) {
Stats.push_back(S);
}
};
}
static ManagedStatic<StatisticInfo> StatInfo;
/// RegisterStatistic - The first time a statistic is bumped, this method is
/// called.
void Statistic::RegisterStatistic() {
// If stats are enabled, inform StatInfo that this statistic should be
// printed.
if (Enabled)
StatInfo->addStatistic(this);
// Remember we have been registered.
Initialized = true;
}
struct NameCompare {
bool operator()(const Statistic *LHS, const Statistic *RHS) const {
int Cmp = std::strcmp(LHS->getName(), RHS->getName());
if (Cmp != 0) return Cmp < 0;
// Secondary key is the description.
return std::strcmp(LHS->getDesc(), RHS->getDesc()) < 0;
}
};
// Print information when destroyed, iff command line option is specified.
StatisticInfo::~StatisticInfo() {
// Statistics not enabled?
if (Stats.empty()) return;
// Get the stream to write to.
std::ostream &OutStream = *GetLibSupportInfoOutputFile();
// Figure out how long the biggest Value and Name fields are.
unsigned MaxNameLen = 0, MaxValLen = 0;
for (unsigned i = 0, e = Stats.size(); i != e; ++i) {
MaxValLen = std::max(MaxValLen,
(unsigned)utostr(Stats[i]->getValue()).size());
MaxNameLen = std::max(MaxNameLen,
(unsigned)std::strlen(Stats[i]->getName()));
}
// Sort the fields by name.
std::stable_sort(Stats.begin(), Stats.end(), NameCompare());
// Print out the statistics header...
OutStream << "===" << std::string(73, '-') << "===\n"
<< " ... Statistics Collected ...\n"
<< "===" << std::string(73, '-') << "===\n\n";
// Print all of the statistics.
for (unsigned i = 0, e = Stats.size(); i != e; ++i) {
std::string CountStr = utostr(Stats[i]->getValue());
OutStream << std::string(MaxValLen-CountStr.size(), ' ')
<< CountStr << " " << Stats[i]->getName()
<< std::string(MaxNameLen-std::strlen(Stats[i]->getName()), ' ')
<< " - " << Stats[i]->getDesc() << "\n";
}
OutStream << std::endl; // Flush the output stream...
if (&OutStream != cerr.stream() && &OutStream != cout.stream())
delete &OutStream; // Close the file.
}