count ip

#include <time.h>
#include <stdio.h>
#include <malloc.h>
#include <stdlib.h>
#define C55 0x5555555555555555ULL
#define C33 0x3333333333333333ULL
#define C0F 0x0f0f0f0f0f0f0f0fULL
#define C01 0x0101010101010101ULL


int count_bytes(unsigned char byte) {
    return (byte & 1) +
        ((byte & 2) >> 1) +
        ((byte & 4) >> 2) +
        ((byte & 8) >> 3) +
        ((byte & 16) >> 4) +
        ((byte & 32) >> 5) +
        ((byte & 64) >> 6) +
        ((byte & 128) >> 7);
}

int main(int argc, char *argv[]) {
    FILE *fp;
    char *line = (char *) malloc(17);
    char *oct = (char *) malloc(4);
    unsigned long long idx;
    unsigned long long *bitmap = (unsigned long long *) calloc
            (sizeof(unsigned long long) * 67108864, 1);

    clock_t begin = clock();
    fp = fopen(argv[1], "r");
    while (fgets(line, 17, fp)) {
        register char *temp = line;
        register char *buf_oct = oct;
        idx = 0;

        while (*temp) {
            if (*temp == '.') {
                *buf_oct = '\0';
                buf_oct = oct;
                idx = (idx << 8) | (unsigned char) atoi(oct);
                temp++;
            }
            *buf_oct++ = *temp++;
        }

        *buf_oct = '\0';
        idx = (idx << 8) | (unsigned char) atoi(oct);
        bitmap[idx / 64] |= (unsigned long long) 1 << (idx % 64);
    }

    int cnt = 0;
    for (int i = 0; i < 67108864; ++i) {
        unsigned long long chunk = bitmap[i];
        chunk -= (chunk >> 1) & C55;              // put count of each 2 bits into those 2 bits
        chunk = (chunk & C33) + ((chunk >> 2) & C33);// put count of each 4 bits into those 4 bits
        chunk = (chunk + (chunk >> 4)) & C0F;        // put count of each 8 bits into those 8 bits
        chunk = (chunk * C01) >> 56;
        cnt += (int) chunk;
    }

    clock_t end = clock();
    double time_spent = (double) (end - begin) / CLOCKS_PER_SEC;
    printf("Time execution: %f seconds; ip: %d\n", time_spent, cnt);
    free(line);
    free(oct);
    free(bitmap);
}