benchmark memory operations from small 32 bytes to 4+ MB. results reported as factional nanoseconds.

mem_size_bench.c

#include <stdio.h>
#include <stdlib.h>
#include <sys/time.h>
#include <string.h>

static long long ustime(void) {
    struct timeval tv;
    long long ust;

    gettimeofday(&tv, NULL);
    ust = ((long long)tv.tv_sec)*1e6;
    ust += tv.tv_usec;
    return ust;
}

#define MB_8 8388608
#define MB_32 MB_8 * 4
#define MB_64 MB_32 * 2
#define MB_4 MB_8/2
int main(int argc, char *argv[]) {
    size_t limit = 32000;
    char *thingOne = malloc(MB_64 + MB_4);
    for (size_t size = 32; size <= MB_64; size *= 2) {

        long long start = ustime();
        for (size_t i = 0; i < limit; i++) {
            memmove(thingOne+8, thingOne+32, size);
        }
        long long end = ustime();

        long long duration_ns = (end - start) * 1000;
        double individual_loop_ns = duration_ns / (double)limit;
        double individual_memmove_time = individual_loop_ns / limit;
        printf("%lu\t%0.4f\n", size, individual_memmove_time);
        fflush(stdout);

    }
}