chronoxor / cppbenchmark Goto Github PK

In README.md

How to build?
Linux
cd build
./unix.sh

don't have build directory and don't have unix.sh in the workspace.

I am browsing the examples and putting things together, and noticed, that the sort example does not really make sense.

Each sort class inheriting from the SortFixture calls Initialize at the beginning of an attempt, which populates the items, but then in each Run called during an attempt, the items are not changed. So the first Run sorts the items and then every subsequent run has the items already sorted.

Hello,
I managed to build the library on my machine with the build/vst.bat script, seems fine.

I tried to link with the library in my C++ console application project, I added include directories - CppBenchmark/Include and lib directories CppBenchmark/bin and added cppbenchmark.lib to my linker settings.

Then to my main.cpp file i just copied some of your examples - the random.cpp one, but when I compile, I get linker errors. Some unersolved symbols in file cppbenchmark.lib(launcher_console.obj) - optparse::OptionParser::print_help(), optparse::OptionParser::error(),optparse::OptionParser::parse_args() and others.

And in file cppbenchmark.lib(phase_metrics.obj) - unresolved symbols hdr_init, hdr_close, hdr_record_values, hrd_min, etc...

Do I need to link other libraries to my project as well?
I am on Win 10, VS 2019

Thanks

I build CppBenchmark library and put libcppbenchmark.a into /usr/lib/, then I try to compile serialize.cpp with flag -lcppbenchmark under FastBinaryEncoding/performance/, but it turns out an error like this:
serialize.cpp:5:10: fatal error: benchmark/cppbenchmark.h: No such file or directory
5 | #include "benchmark/cppbenchmark.h"
| ^~~~~~~~~~~~~~~~~~~~~~~~~~
compilation terminated.
What should I do?

When using std::aligned_storage, you must explicitly call constructor and destructors on the "reinterpreted_cast"'d object (with placement new, and explicit output->~T() call).

In all case, std::aligned_storage is not required in this file, since the compiler will ensure that the structure is correctly aligned anyway.
By default, unless you pragma pack your structure (which is not the case here), the compiler will ensure the structure is aligned with respect to its largest field's alignment requirement, and that's exactly what you get with the std::aligned_storage code that's written.

I'm not sure what functionality the fpu example is trying to demonstrate but I think it makes no sense. clock_gettime is being used to get the timestamp used for time calculation, but this function itself takes ~1us, which means it should not be used to benchmark sub-us activities like simple floating point operations in this example. As shown in the following example:

#include <cmath>
#include <ctime>

#include "benchmark/cppbenchmark.h"

BENCHMARK("empty", CppBenchmark::Settings().Attempts(2).Duration(5)) {}

BENCHMARK("sin", CppBenchmark::Settings().Attempts(2).Duration(5)) {
  [[maybe_unused]] static double sum = 0;
  sum += sin(123.456);
}

BENCHMARK("timestamp", CppBenchmark::Settings().Attempts(2).Duration(5)) {
  System::Timestamp();
}

BENCHMARK_MAIN()

Looks like cppbenchmark not working properly with gcc-13.

See my repo with some C++ benchmarks and issue: tilir/benchmarks#2