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Further benchmark improvements

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git-svn-id: http://svn.boost.org/svn/boost/sandbox/endian@74297 b8fc166d-592f-0410-95f2-cb63ce0dd405
This commit is contained in:
bemandawes
2011-09-07 16:03:15 +00:00
parent 4955da9ba5
commit 14dc87c0fa
2 changed files with 76 additions and 31 deletions
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2
boost/endian/support/timer.hpp
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@@ -58,7 +58,7 @@ namespace boost
~timer() {} // never throws
void start();
const times_t& stop();
const times_t& stop();
bool stopped() const { return m_flags& m_stopped; }
void elapsed(times_t& result); // does not stop()

105
libs/endian/test/benchmark.cpp
View File

@@ -7,11 +7,13 @@
#define _CRT_SECURE_NO_WARNINGS
#include <cstdlib>
#include <boost/endian/conversion.hpp>
#include <boost/random.hpp>
#include <boost/cstdint.hpp>
#include <boost/endian/support/timer.hpp>
#include <iostream>
#include <string>
using namespace boost;
using std::cout;
@@ -19,33 +21,44 @@ using std::cerr;
using std::endl;
using std::vector;
#define BENCHMARK(Function) \
{ \
cout << "\nRunning benchmark..." << endl << ' '; \
int64_t sum = 0; \
int32_t value; \
\
endian::run_timer t; \
\
for (int32_t i = n; i; --i) \
{ \
value = 0x01020304; \
Function(value); \
sum += value ; \
} \
\
t.report(); \
\
cout << " Benchmark complete\n" \
" sum is " << sum << endl; \
}
namespace
{
std::string command_args;
long n;
long seed = 1;
long long n;
int places = 2;
bool verbose (false);
typedef int32_t (*timee_func)(int32_t);
endian::microsecond_t benchmark(timee_func timee, const char* msg,
endian::microsecond_t overhead = 0)
{
if (verbose)
cout << "\nRunning benchmark..." << endl;
int64_t sum = 0;
endian::times_t times;
endian::microsecond_t cpu_time;
endian::run_timer t(places);
for (long long i = n; i; --i)
{
sum += timee(static_cast<int32_t>(i)) ;
}
times = t.stop();
cpu_time = (times.system + times.user) - overhead;
const long double sec = 1000000.0L;
cout.setf(std::ios_base::fixed, std::ios_base::floatfield);
cout.precision(places);
cout << msg << " " << cpu_time / sec << endl;
if (verbose)
{
t.report();
cout << " Benchmark complete\n"
" sum is " << sum << endl;
}
return cpu_time;
}
void process_command_line(int argc, char * argv[])
{
@@ -59,12 +72,18 @@ namespace
cout << command_args << '\n';;
if (argc >=2)
n = std::atol(argv[1]);
#ifndef _MSC_VER
n = std::atoll(argv[1]);
#else
n = _atoi64(argv[1]);
#endif
for (; argc > 2; ++argv, --argc)
{
if ( *(argv[2]+1) == 'p' )
places = atoi( argv[2]+2 );
else if ( *(argv[2]+1) == 'v' )
verbose = true;
else
{
cout << "Error - unknown option: " << argv[2] << "\n\n";
@@ -78,19 +97,43 @@ namespace
cout << "Usage: benchmark n [Options]\n"
" The argument n specifies the number of test cases to run\n"
" Options:\n"
" -v Verbose messages\n"
" -p# Decimal places for times; default -p" << places << "\n";
return std::exit(1);
}
}
inline void noop(int32_t&) {}
inline void shift_and_mask(int32_t& x)
inline void in_place(int32_t& x)
{
x = ((x << 24) & 0xff000000) | ((x << 8) & 0x00ff0000) | ((x >> 24) & 0x000000ff)
| ((x >> 8) & 0x0000ff00);
}
inline int32_t by_return(int32_t x)
{
return ((x << 24) & 0xff000000) | ((x << 8) & 0x00ff0000) | ((x >> 24) & 0x000000ff)
| ((x >> 8) & 0x0000ff00);
}
int32_t modify_noop(int32_t x)
{
int32_t v(x);
return v;
}
int32_t modify_in_place(int32_t x)
{
int32_t v(x);
in_place(v);
return v;
}
int32_t modify_by_return(int32_t x)
{
int32_t v(x);
return by_return(v);
}
} // unnamed namespace
//-------------------------------------- main() ---------------------------------------//
@@ -99,9 +142,11 @@ int main(int argc, char * argv[])
{
process_command_line(argc, argv);
BENCHMARK(noop);
BENCHMARK(endian::reorder);
BENCHMARK(shift_and_mask);
endian::microsecond_t overhead;
overhead = benchmark(modify_noop, "modify no-op");
benchmark(modify_in_place, "modify in place", overhead);
benchmark(modify_by_return, "modify by return", overhead);
return 0;
}