pow

// sploit.cpp : Defines the entry point for the console application.
//

#include "stdafx.h"
#include <string.h>
#include <stdlib.h>
#include <Windows.h>
#include <cmath>


static double LibPow(double x, int n)
{
    if (n < 0)
    { return (1.0 / LibPow(x, -n)); }

    switch (n)
    {
        case 0:
        { return (1.0); }
        case 1:
        { return (x); }
        case 2:
        { return (x * x); }
        case 3:
        { return (x * x * x); }
        case 4:
        {
            double x2 = x * x;
            return (x2 * x2);
        }                case 5:
        {
            double x2 = x * x;
            return (x2 * x2 * x);
        }
        case 6:
        {
            double x2 = x * x;
            return (x2 * x2 * x2);
        }
        case 7:
        {
            double x3 = x * x * x;
            return (x3 * x3 * x);
        }
        case 8:
        {
            double x2 = x * x;
            double x4 = x2 * x2;
            return (x4 * x4);
        }
        case 9:
        {
            double x3 = x * x * x;
            return (x3 * x3 * x3);
        }
        case 10:
        {
            double x2 = x * x;
            double x4 = x2 * x2;
            return (x4 * x4 * x2);
        }
        default:
        { return std::pow(x, n); }
    }
}

static double LibIfPow(double x, int n)
{
    if (n < 0)
    { return (1.0 / LibPow(x, -n)); }

    if(n == 0) return (1.0);
    else if(n == 1) return (x);
    else if(n == 2) return (x * x);
    else if(n == 3) return (x * x * x);
    else if(n == 4) {
            double x2 = x * x;
            return (x2 * x2);
    }
    else if(n == 5) {
            double x2 = x * x;
            return (x2 * x2 * x);
    } else if(n == 6) {
            double x2 = x * x;
            return (x2 * x2 * x2);
    } else if(n == 7) {
            double x3 = x * x * x;
            return (x3 * x3 * x);
    }
    else if(n == 8) {
            double x2 = x * x;
            double x4 = x2 * x2;
            return (x4 * x4);
    }
    else if(n == 9) {
            double x3 = x * x * x;
            return (x3 * x3 * x3);
    } else if(n == 10) {
            double x2 = x * x;
            double x4 = x2 * x2;
            return (x4 * x4 * x2);
    } else { return std::pow(x, n); }

}

#define METHOD 3
#define LIMIT 11
int _tmain(int argc, _TCHAR* argv[])
{
    DWORD64 begin = __rdtsc();
    double sum = 0;
    for(int i = 0; i < 100000000; ++i)
    {
#if METHOD == 1
        sum += LibPow(112.3, rand() % LIMIT);

#else
#if METHOD == 2
        sum += LibIfPow(112.3, rand() % LIMIT);
#else
        sum += std::pow(112.3, rand() % LIMIT);
#endif
#endif
    }

    DWORD64 end = __rdtsc();
    DWORD64 diff = end-begin;

    LARGE_INTEGER res;
    QueryPerformanceFrequency(&res);
    printf("\n%llu %llu", diff, diff/res.QuadPart);
    return sum;
}