How To Write Numerical Code

#include <stdio.h>

float func1()
{
        int i;
        float ret = 0;

        for (i = 0; i < 1000000; ++i) {
                ret += (1/i);
        }

        return ret;
}

float func2()
{
        int i;
        float ret = 0;

        for (i = 0; i < 1000000; ++i) {
                ret += (1/(i + 1));
        }

        return ret;
}

void func3()
{
}

int main()
{
        int i;

        printf("result: %.2f\n", func1());
        printf("result: %.2f\n", func2());
        func3();

        return 0;
}

~$ gcc -O0 -g -pg -o hotspot hotspot.c
~$ gprof hotspot gmon.out
Flat profile:

Each sample counts as 0.01 seconds.
  %   cumulative   self              self     total
 time   seconds   seconds    calls  ms/call  ms/call  name
101.01      0.03     0.03        1    30.30    30.30  func2
  0.00      0.03     0.00        1     0.00     0.00  func1
  0.00      0.03     0.00        1     0.00     0.00  func3