generic insertion sort

// Generic insertion sort
// Can be compiled using : -W -Wall -Werror -Wextra -ansi -pedantic

void sort(void *p, int n, int size, int cmp(void *, void *))
{
  int i;
  int j;
  void *a;
  a = __builtin_malloc(size);

  for (i=1; i<n; i++)
  {
    __builtin_memcpy(a, (char*)p+i*size, size);

    for (j=i; j>0 && cmp((char*)p+(j-1)*size, a)>0; j--)
    {
      __builtin_memcpy((char*)p+j*size, (char*)p+(j-1)*size, size);
    }

    __builtin_memcpy((char*)p+j*size, a, size);
  }

  __builtin_free(a);
}


int compare(void *a, void *b)
{
  return *((int*)a) - *((int*)b);
}

#include <stdio.h>

int main()
{
  int tab[5] = {2,986,-9,0,16};
  printf("%d %d %d %d %d\n", tab[0], tab[1], tab[2], tab[3], tab[4]);
  sort(tab, 5, sizeof(int), compare);
  printf("%d %d %d %d %d\n", tab[0], tab[1], tab[2], tab[3], tab[4]);
  return 0;
}