Implement a Simple Benchmark

Implement a Simple Benchmark#

This section shows how to implement a simple benchmark using cpp-stat-bench library.

Prerequisites#

Sample Code with Explanation#

Example of a simple benchmark.#
#include <stat_bench/benchmark_macros.h>

[[nodiscard]] int fibonacci(int number);

// Define a benchmark.
// First argument is the name of the group of benchmarks,
// and the second argument is the name of the case of the benchmark.
STAT_BENCH_CASE("Fibonacci", "fibonacci(10)") {
    const int number = 10;
    // Measure the time to invoke a function.
    // The return value is handled by cpp-stat-bench library to prevent
    // compilers from optimizing out the function call.
    STAT_BENCH_MEASURE() { return fibonacci(number); };
}

// Define another benchmark in the same group.
STAT_BENCH_CASE("Fibonacci", "fibonacci(15)") {
    const int number = 15;
    STAT_BENCH_MEASURE() { return fibonacci(number); };
}

// Define main function. (Required once in an executable.)
STAT_BENCH_MAIN

int fibonacci(int number) {
    if (number < 2) {
        return 1;
    }
    return fibonacci(number - 1) + fibonacci(number - 2);
}

Execution#

You can build the above code and run the resulting executable without arguments to see an output similar to the one below.

Example output to the console.#
cpp-stat-bench 0.21.0

Benchmark start at 2025-02-11T14:12:34.660223+0000

Time resolution: 1.000e-09 sec.

========================================================================================================================
Processing Time
========================================================================================================================

>> Fibonacci
                                                                                Time [us]
                                                            Iterations Samples       Mean Std. Err.       Max Custom Outputs (mean)
------------------------------------------------------------------------------------------------------------------------
fibonacci(10)                                                        1     100     0.1431    0.0008    0.2140
fibonacci(15)                                                        1     100     1.4411    0.0207    3.4840

========================================================================================================================
Mean Processing Time
========================================================================================================================

>> Fibonacci
                                                                                Time [us]
                                                            Iterations Samples       Mean Std. Err.       Max Custom Outputs (mean)
------------------------------------------------------------------------------------------------------------------------
fibonacci(10)                                                  1000000      30     0.0009    0.0000    0.0011
fibonacci(15)                                                  1000000      30     0.0012    0.0000    0.0016

Benchmark finished at 2025-02-11T14:12:36.373433+0000

Further Reading#