  static void *tiny_sbrk(ptrdiff_t increment)
  {
    void *p = ecos_gc_brk;
    ecos_gc_brk += increment;
    if ((word)ecos_gc_brk > (word)(ecos_gc_memory + sizeof(ecos_gc_memory))) {
      ecos_gc_brk -= increment;
      return NULL;
    }
    return p;
  }
  static void *tiny_sbrk(ptrdiff_t increment)
  {
    void *p = ecos_gc_brk;
    ecos_gc_brk += increment;
    if ((word)ecos_gc_brk > (word)(ecos_gc_memory + sizeof(ecos_gc_memory))) {
      ecos_gc_brk -= increment;
      return NULL;
    }
    return p;
  }