#include <stdio.h>

#include <stdlib.h>

#include <time.h>

#define LEN (1024 * 1024 * 8)

#define LOOP 50

struct timespec start;

static int vec[16] = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };

static void loop(char *inst) {

void *table[] = { &&L0, &&L1, &&L2, &&L3, &&L4, &&L5, &&L6, &&L7, &&L8, &&L9, &&L10, &&L11, &&L12, &&L13, &&L14, &&L15 };

void **addrs = malloc(LEN * sizeof(void *));

for (int i = 0; i < LEN; i++)

addrs[i] = table[inst[i]];

clock_gettime(CLOCK_REALTIME, &start);

#define NEXT goto *(*addrs++)

NEXT;

L0: return;

L1: for (int i = 0; i < LOOP; i++) vec[1]++; NEXT;

L2: for (int i = 0; i < LOOP; i++) vec[2]++; NEXT;

L3: for (int i = 0; i < LOOP; i++) vec[3]++; NEXT;

L4: for (int i = 0; i < LOOP; i++) vec[4]++; NEXT;

L5: for (int i = 0; i < LOOP; i++) vec[5]++; NEXT;

L6: for (int i = 0; i < LOOP; i++) vec[6]++; NEXT;

L7: for (int i = 0; i < LOOP; i++) vec[7]++; NEXT;

L8: for (int i = 0; i < LOOP; i++) vec[8]++; NEXT;

L9: for (int i = 0; i < LOOP; i++) vec[9]++; NEXT;

L10: for (int i = 0; i < LOOP; i++) vec[10]++; NEXT;

L11: for (int i = 0; i < LOOP; i++) vec[11]++; NEXT;

L12: for (int i = 0; i < LOOP; i++) vec[12]++; NEXT;

L13: for (int i = 0; i < LOOP; i++) vec[13]++; NEXT;

L14: for (int i = 0; i < LOOP; i++) vec[14]++; NEXT;

L15: for (int i = 0; i < LOOP; i++) vec[15]++; NEXT;

}

void printvec() {

for (int i = 0; i < 16; i++)

printf("%d ", vec[i]);

printf("\n");

}

void printtime() {

struct timespec end;

clock_gettime(CLOCK_REALTIME, &end);

long t1 = start.tv_sec * 1000 * 1000 * 1000 + start.tv_nsec;

long t2 = end.tv_sec * 1000 * 1000 * 1000 + end.tv_nsec;

printf("time: %f\n", (t2 - t1) / 1e9);

}

int main(int argc, char **argv) {

char *inst = malloc(LEN);

for (int i = 0; i < LEN - 1;) {

int op = rand() & 15;

if (op == 0) continue;

inst[i++] = op;

}

inst[LEN - 1] = 0;

loop(inst);

printvec();

printtime();

return 0;

}