That's the only one I've ever seen, and it's really just checking for the absence of '%'.

What if it could convert:

printf("parsed: %s to %i\n", x, y);

To:

puts("parsed: "); puts(x); puts(" to "); _puti(y); putc('\n');

Well. Then we'd have a lot more function calls overhead. Maybe something like:

_printf_nofloat("parsed: %s to %i\n", x, y);