b := s.Bytes()
	if b[31] > 127 {
		panic("scalar has high bit set illegally")
	}
	if w < 2 {
		panic("w must be at least 2 by the definition of NAF")
	} else if w > 8 {
		panic("NAF digits must fit in int8")
	}

	var naf [256]int8
	var digits [5]uint64

	for i := 0; i < 4; i++ {
		digits[i] = byteorder.LeUint64(b[i*8:])
	}

	width := uint64(1 << w)

	// fewer additions).

	basepointNafTable := basepointNafTable()
	var aTable nafLookupTable5
	aTable.FromP3(A)
	// Because the basepoint is fixed, we can use a wider NAF
	// corresponding to a bigger table.
	aNaf := a.nonAdjacentForm(5)
	bNaf := b.nonAdjacentForm(8)

	// Find the first nonzero coefficient.
	i := 255
	for j := i; j >= 0; j-- {