The other solutions are correct, it's mainly up to the implementation of the processor.
I decided to try it. Below is a test for N = 10000000, addition took .035s and subtraction took .044s.
Edit: this editor converts > to > and & to &
#include <stdio.h>
#include <stdlib.h>
#include <time.h>
void add(int *a, int b)
{
*a = *a + b;
}
void sub(int *a, int b)
{
*a = *a - b;
}
void runAddTest(int n)
{
int i=0;
while(n-->0)
{
add(&i,1);
}
}
void runSubTest(int n)
{
int i=n;
while(n-->;0)
{
sub(&i,1);
}
}
int main()
{
int N = 10000000;
printf("Running, please wait...\n");
clock_t t;
t=clock();
runAddTest(N);
t=clock() -t;
clock_t t2=clock();
runSubTest(N);
t2=clock() -t2;
printf("Addition: Time %f seconds.\n",((float)t)/CLOCKS_PER_SEC);
printf("Subtraction: Time %f seconds.\n",((float)t2)/CLOCKS_PER_SEC);
getchar();
return 0;
}