void sal_free(void *object)
{
    assert(object != NULL);

    // access header
    free_header_t *curr = (void *)(object - HEADER_SIZE);
    vaddr_t chosen_ptr = (void *)(object) - (void *)(memory) - HEADER_SIZE;

    // validate header
    if(curr->magic != MAGIC_ALLOC) {
        if(curr->magic != MAGIC_FREE) {
            fprintf(stderr, "  memory corruption(sf0). aborting operation\n");
            sal_stats();
            abort();
        } else if(curr->magic == MAGIC_FREE) {
            fprintf(stderr, "  memory already free...");
            return;
        }
    }
    assert(curr->magic == MAGIC_ALLOC);

    // FREE DA MEMORY!!!!
    free_header_t *temp = (void *)(memory + free_list_ptr);
    if(temp->magic != MAGIC_FREE) {
        // just freed the only free mem block.
        free_list_ptr = chosen_ptr;
        curr->next = chosen_ptr;
        curr->prev = chosen_ptr;
        fprintf(stdout, "  >> freed memory size %d at offset %d\n"
                        "     no merging required\n",
            curr->size, chosen_ptr);
        curr->magic = MAGIC_FREE;
        return;
    }
}