llvm-project/lldb/tools/lldb-perf/lib/Metric.cpp

61 lines
1.5 KiB
C++

//===-- Metric.cpp ----------------------------------------------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#include "Metric.h"
#include "MemoryGauge.h"
#include <cmath>
using namespace lldb_perf;
template <class T> Metric<T>::Metric() : Metric("") {}
template <class T>
Metric<T>::Metric(const char *n, const char *d)
: m_name(n ? n : ""), m_description(d ? d : ""), m_dataset() {}
template <class T> void Metric<T>::Append(T v) { m_dataset.push_back(v); }
template <class T> size_t Metric<T>::GetCount() const {
return m_dataset.size();
}
template <class T> T Metric<T>::GetSum() const {
T sum = 0;
for (auto v : m_dataset)
sum += v;
return sum;
}
template <class T> T Metric<T>::GetAverage() const {
return GetSum() / GetCount();
}
// Knuth's algorithm for stddev - massive cancellation resistant
template <class T>
T Metric<T>::GetStandardDeviation(StandardDeviationMode mode) const {
size_t n = 0;
T mean = 0;
T M2 = 0;
for (auto x : m_dataset) {
n = n + 1;
T delta = x - mean;
mean = mean + delta / n;
M2 = M2 + delta * (x - mean);
}
T variance;
if (mode == StandardDeviationMode::ePopulation || n == 1)
variance = M2 / n;
else
variance = M2 / (n - 1);
return sqrt(variance);
}
template class lldb_perf::Metric<double>;
template class lldb_perf::Metric<MemoryStats>;