in glog.go [603:612]
func (buf *buffer) nDigits(n, i, d int, pad byte) { j := n - 1 for ; j >= 0 && d > 0; j-- { buf.tmp[i+j] = digits[d%10] d /= 10 } for ; j >= 0; j-- { buf.tmp[i+j] = pad } }