Decrement integer without volatile

main.c

#include <stdio.h>
#include <stdint.h>
#include <time.h>

int main()
{
    puts("Lets go");

    time_t t;
    int elapsed_time = time(&t);

    uint32_t i = 999999999;
    for( ; i > 0 ; i--);

    elapsed_time = time(&t) - elapsed_time;
    printf("Elapsed time: %ds\n", elapsed_time);
    return 0;
}