Getting started

git clone --recursive --shallow-submodules https://github.com/seantalts/perf-math.git

First run

(unless you have the Google benchmark library installed)

cd benchmark
git clone --depth=1 https://github.com/google/googletest
mkdir build && cd build
cmake .. -DCMAKE_BUILD_TYPE=RELEASE
make

Writing a benchmark

There is an example, this matstuff.cpp. You can make your own or reuse this file. See https://github.com/google/benchmark for details.

Essential structure:

static void BM_Name(benchmark::State& state) {
  setup();
  for (auto _ : state) {
    thing_to_time();
  }
}
BENCHMARK(BM_Name);

BENCHMARK_MAIN();

Making a benchmark

$ make matstuff && ./matstuff 
c++ -Imath/lib/eigen_3.3.3/ -Ibenchmark/include -std=c++1y -Imath/
-Imath/lib/boost_1.66.0  -Lbenchmark/build/src  matstuff.cpp  -lbenchmark -o
matstuff
2018-08-29 04:52:47
Running ./matstuff
Run on (4 X 2200 MHz CPU s)
CPU Caches:
  L1 Data 32K (x2)
    L1 Instruction 32K (x2)
      L2 Unified 262K (x2)
        L3 Unified 4194K (x1)
        ------------------------------------------------------
        Benchmark               Time           CPU Iterations
        ------------------------------------------------------
        BM_LogOrig     2688940713 ns 2669717000 ns          1
        BM_LogProposed 2711084835 ns 2696761000 ns          1