var z nat
				z = z.expWW(x, y)
				z.utoa(base) // warm divisor cache
				b.StartTimer()

				for i := 0; i < b.N; i++ {
					_ = z.utoa(base)
				}
			})
		}
	}
}

func BenchmarkLeafSize(b *testing.B) {
	for n := 0; n <= 16; n++ {
		b.Run(fmt.Sprint(n), func(b *testing.B) { LeafSizeHelper(b, 10, n) })
	}
	// Try some large lengths
	for _, n := range []int{32, 64} {

// range 2..64 shows that values of 8 and 16 work well, with a 4x speedup at medium lengths and
// ~30x for 20000 digits. Use nat_test.go's BenchmarkLeafSize tests to optimize leafSize for
// specific hardware.
func (q nat) convertWords(s []byte, b Word, ndigits int, bb Word, table []divisor) {
	// split larger blocks recursively
	if table != nil {