Paste: silly.c

//  gcc -O3 -std=c99 -o silly silly.c -lm

#include <math.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/time.h>

struct timeval TBeg, TEnd;

#define STARTTm         gettimeofday(&TBeg, NULL)
#define ENDTm           gettimeofday(&TEnd, NULL)

/* Elapsed time calculation, microseconds */
 #define DeltaUSec                                       \
((double)(TEnd.tv_sec - TBeg.tv_sec) * 1000000.0 +     \
 (double)(TEnd.tv_usec - TBeg.tv_usec))

struct Point
{
    float x, y, z;
};

float pointNorm(struct Point* p)
{
    return sqrt(p->x * p->x +
                p->y * p->y +
                p->z * p->z);
}

void initPoint(struct Point* p, int n)
{
    p->x = sin(n);
    p->y = cos(n) * 3.0;
    float s = sin(n);
    p->z = (s * s) / 2.0;
}

void normalizePoint(struct Point * p)
{
    float norm = pointNorm(p);
    p->x /= norm;
    p->y /= norm;
    p->z /= norm;
}

struct Point* makePoints(int len)
{
    struct Point* points = (struct Point *)malloc(len * sizeof(struct Point));
    
    for (int i = 0; i < len; i++) {
        initPoint(&points[i], i);
    }
 
    return points;
}

void normalizePoints(struct Point * point, int len)
{
    for (int i = 0; i < len; i++) {
        normalizePoint(&point[i]);
    }
}

void printPoint(struct Point * p)
{
    printf("%f, %f, %f\n", p->x, p->y, p->z);
}

#define MAX(a,b)         (a < b) ?  (b) : (a)

struct Point* maxPoints(struct Point * p, int len)

{
    struct Point * maxp = (struct Point*)malloc(sizeof(struct Point));
    maxp->x = maxp->y = maxp->z = 0;
    for (int i = 0; i < len; i++) {
        maxp->x = MAX(maxp->x, p[i].x);
        maxp->y = MAX(maxp->y, p[i].y);
        maxp->z = MAX(maxp->z, p[i].z);
    }
    return maxp;
}

void benchmark(int len)
{
    struct Point* points = makePoints(len);
    normalizePoints(points, len);
    printPoint(maxPoints(points, len));
}

int main()
{
    for (int i = 0; i < 8; i++) {
        STARTTm;
        benchmark(5000000);
        ENDTm;
        printf("Time: %0.f\n", DeltaUSec / 1000.0);
    }

    return 0;
}