C file complied wrongly

I'm currently reading a book 'Introducing Speech and Language Processing'.

In the book lets me know a code that generates 200Hz cosine wave.

Below is the code. (file name is coswave.c)

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

int main() {
  int length, status, i;
  short int *x;
  float freq;
  double arg, twopi;
  FILE *file_id;

  length = 8000;
  freq = 0.025;
  twopi = 8.0 * atan(1.0);
  arg = twopi * freq;

  x = (short int *) calloc(length, sizeof(short int));

  if (!x) {
    printf("Unable to allocate space for samples\n");
    exit(1);
  }

  for (i = 0; i < length; i++)
    x[i] = (short int) 32000 * cos(i * arg);

  file_id = fopen("cosine.dat", "wb");
  
  if (file_id == NULL) {
    printf("Unable to open file\n");
    exit(1);
  }

  status = fwrite(x, sizeof(short int), length, file_id);
  
  if (status < length) {
    printf("Unable to write all samples\n");
    exit(1);
  }

  fclose(file_id);
  return 0;
}

After writing that code, in the cmd, I typed the below.

gcc -c coswave.c // this command gives me coswave.o file
gcc -o bleep.exe coswave.o // this command gives md bleep.exe file

After that, I executed bleep.exe file and cosine.dat is created.

I opened it with 'hexdump for VSC' extension, but except a first line all contents are filled with 00.

00000000: 00 7D 00 00 00 00 00 00 00 00 00 00 00 00 00 00    .}..............

What is wrong here?

for (i = 0; i < length; i++) {
    x[i] = (short int) 32000 * cos(i * arg);
    printf("%d %d \n", i, x[i]);
}

According to printf(), There is no problem with cosine values.

My OS is Windows and I used mingw gcc. Thank you very much.