can someone please help! task is to optimize code and get it to run faster using

Question

can someone please help!

task is to optimize code and get it to run faster using C program and GCC.

this code needs to be compiled WITHOUT gcc optimization feature. Compile the code like this: gcc -Wall -g Code.c -o Code
code needs to run less then 5.0 seconds.

sample run:

$ gcc -Wall test.c -0 test
$ time ./test

real 0m4.412s
user 0m4.390s
sys 0m0.000s


// This is the starting code.

#include <stdio.h>
#include <stdlib.h>
#include <time.h>

// Submitted code must have the correct values for these two constants:
// N_TIMES: 200000
// ARRAY_SIZE: 9973

#define N_TIMES 200000
#define ARRAY_SIZE 9973

int main (void)
{
int *array = calloc(ARRAY_SIZE, sizeof(int));
int sum = 0;
int checksum = 0;
int i;
int j;
int x;

// Initialize the array with random values 0 to 13.
//
srand(time(NULL));
for (j=0; j < ARRAY_SIZE; j++) {

x = rand() / (int)(((unsigned)RAND_MAX + 1) / 14);
array[j] = x;
checksum += x;
}
//printf("Checksum is %d. ",checksum);

for (i = 0; i < N_TIMES; i++) {

// ---------------------------------------------------------------
// Do not alter anything above this line, except for any variables that need to be declared
// outside of the i loop. Here is where you make your changes to
// optimize performance.


for (j=0; j < ARRAY_SIZE; j++) {
sum += array[j];
// printf("Sum is now: %d ",sum);
}


// Do not alter anything below this line.
// ---------------------------------------------------------------

// Check each iteration.
//
if (sum != checksum) {
printf("Checksum error! ");
}
sum = 0;

}
return 0;

Explanation / Answer

try optimizing by manually unrolling the loop the loop code is for (j=0; j

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