simple benchmark header only

usage :

• BENCH_START : start the timer
• BENCH_LOG : log the time, increase iteration counter
• BENCH_MEAN(*m) : get mean
• BENCH_MEAN_STD(*m,*s) : get mean and stdev
• BENCH_LAST : get last logged time
• BENCH_PRINT : print mean and stdev
• BENCH_PRINT_PERIOD(t) : print every 't' iterations
• BENCH_PERIOD(t) : evaluate to true 't' iterations
• BENCH_BENCH(nb_repeat, function) : bench function with 'nb_repeat' repetition
• BENCH_BENCH_PRINT(nb_repeat, print_period, function) : bench function and print every 'print_period' iterations
• BENCH_RESET : reset iteration counter
• BENCH_INIT : init necessary variables

warning : mean and stdev are incorrect until the array is filled once (a star* is put at end of the print to warn of this case)

config :

• BENCH_LOG_SIZE : set the log size (default : 128)
• BENCH_PRECISION : set the time precision : s, ms, µs, ns (default : ms)
• BENCH_fd : set the output FILE* of fprintf (default : stdout)
• BENCH_PRINT_FORMAT : printf format for time (default : "%9.4lf")
• BENCH_NO_WARN_LOGSIZE : disable the star* at end of the print to warn that the array isn't filled.
• BENCH_CSV_PRINT : set the print output in csv format (mean, stdev, iterations)
• BENCH_NO_AUTO_INIT : disable auto init globals variables

dependencies :

• math.h : sqrt(), define BENCH_NO_SQRT to disable and get variance instead of stdev, or define your own sqrt in __BENCH_SQRT__
• time.h : clock_gettime()

example :

#define BENCH_LOG_SIZE 256
#define BENCH_PRECISION µs
#define BENCH_NO_AUTO_INIT
#include "bench.h"

void func()
{
    BENCH_INIT
    for(int i = 0; i < nb_repeat; i++){
        BENCH_START
        function_to_bench();
        BENCH_LOG
        BENCH_PRINT_PERIOD(16)
    }
    // same as :
    BENCH_BENCH_PRINT(nb_repeat, 16, function_to_bench());

    BENCH_BENCH(nb_repeat, 
                    reset_function_to_bench();
                    function_to_bench();
                );

    BENCH_PRINT
    printf("%lf\n", BENCH_LAST);

    double mean;
    BENCH_MEAN(&mean);
}