#include <sys/stat.h>
#include <sys/time.h>
#include <sys/types.h>
#include <iostream>
using namespace std;

//g++ -O2 -o sillybenchmark sillybenchmark.cpp


typedef unsigned long long uint64;
class ZTimer
{
public:
    struct timeval t1, t2;
public:
    ZTimer() { gettimeofday(&t1,0); t2 = t1; }
    void reset() {gettimeofday(&t1,0); t2 = t1;}
    int elapsed() { return ((t2.tv_sec - t1.tv_sec) * 1000) + ((t2.tv_usec - t1.
tv_usec) / 1000); }
    int split() { gettimeofday(&t2,0); return elapsed(); }
};


uint64 test1() {// standard scalar product
    const int N =1024*32;
    uint64 vector1[N];
    uint64 vector2[N];
    uint64 answer;
    for(int k =0; k<N;++k)
     answer += vector1[k] * vector2[k];
    return answer;
}

uint64 test2() {//  scalar product 2x2
    const int N = 1024*32;
    uint64 vector1[N];
    uint64 vector2[N];
    uint64 answer;
    for(int k =0; k+1<N;k+=2)
     answer += vector1[k] * vector2[k]+vector1[k+1] * vector2[k+1];
    return answer;
}

uint64 test3() {// not a scalar product (fewer multiplications)
    const int N = 1024*32;
    uint64 vector1[N];
    uint64 vector2[N];
    uint64 answer;
    for(int k =0; k+1<N;k+=2)
     answer += ( vector1[k] + vector2[k] ) * ( vector1[k+1] + vector2[k+1] );
    return answer;
}

uint64 test4() {// standard scalar product with squares
    const int N =1024*32;
    uint64 vector1[N];
    uint64 vector2[N];
    uint64 answer;
    for(int k =0; k<N;++k) {
     answer += (vector1[k] + vector2[k])* (vector1[k] + vector2[k]);
    }
    return answer;
}

uint64 test5() {//  scalar product 4x4
    const int N = 1024*32;
    uint64 vector1[N];
    uint64 vector2[N];
    uint64 answer;
    for(int k =0; k+1<N;k+=4)
     answer += vector1[k] * vector2[k]+vector1[k+1] * vector2[k+1]+vector1[k+2] * vector2[k+2]+vector1[k+3] * vector2[k+3];
    return answer;
}

uint64 test6() {//  just additions
    const int N = 1024*32;
    uint64 vector1[N];
    uint64 vector2[N];
    uint64 answer;
    for(int k =0; k+1<N;k+=4)
     answer += vector1[k] + vector2[k];
    return answer;
}

int main(int params, char ** args) {
    ZTimer t;
    uint64 fakesum;
    double timeelapsed;
    t.reset();
    for(int loop = 1; loop<10000;++loop) fakesum += test1();
    timeelapsed = t.split()/(1000.0);
    cout<<timeelapsed<<endl;
    t.reset();
    for(int loop = 1; loop<10000;++loop) fakesum += test2();
    timeelapsed = t.split()/(1000.0);
    cout<<timeelapsed<<endl;
    t.reset();
    for(int loop = 1; loop<10000;++loop) fakesum += test3();
    timeelapsed = t.split()/(1000.0);
    cout<<timeelapsed<<endl;
    t.reset();
    for(int loop = 1; loop<10000;++loop) fakesum += test4();
    timeelapsed = t.split()/(1000.0);
    cout<<timeelapsed<<endl;
    t.reset();
    for(int loop = 1; loop<10000;++loop) fakesum += test5();
    timeelapsed = t.split()/(1000.0);
    cout<<timeelapsed<<endl;
    t.reset();
    for(int loop = 1; loop<10000;++loop) fakesum += test6();
    timeelapsed = t.split()/(1000.0);
    cout<<timeelapsed<<endl;
    cout<<endl;
    cout<<fakesum<<endl;
}