0_result

-O3
* C: 100% (~1.14sec)
* C++: 99.73%
* C++ exception: 84.6%

-O2
* C: 100% (~2.12sec)
* C++: 100.51%
* C++ exception: 74.02%

% of time, lower is better.

a.c

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


int64_t foo(int n, int64_t *counter) {
    (*counter)++;
    if(n < 2 && *counter > 500000000) return -1;

    if(n) {
        for(int i=0;i<n;i++) {
            if(foo(n-1, counter) == -1) return -1;
        }
    }
    return 0;
}

int main() {
    clock_t start = clock();
    double duration;

    int64_t result = 0;
    foo(14, &result);
    printf("result %ld\n", result);

    duration = ( clock() - start ) / (double) CLOCKS_PER_SEC;

    printf("Duration: %f\n", duration);
}

exception.cpp

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


void foo(int n, int64_t *counter) {
    (*counter)++;
    if(n < 2 && *counter > 500000000) throw *counter;

    if(n) {
        for(int i=0;i<n;i++) {
            foo(n-1, counter);
        }
    }
}

int main() {
    clock_t start = clock();
    double duration;

    int64_t result = 0;
    try {
        foo(14, &result);
    } catch (int64_t e) {
        printf("exception %ld\n", e);
    }
    printf("result %ld\n", result);

    duration = ( clock() - start ) / (double) CLOCKS_PER_SEC;

    printf("Duration: %f\n", duration);
}