1package x448
  2
  3import (
  4	"encoding/binary"
  5	"math/bits"
  6
  7	"github.com/cloudflare/circl/math/fp448"
  8)
  9
 10func doubleGeneric(x, z *fp448.Elt) {
 11	t0, t1 := &fp448.Elt{}, &fp448.Elt{}
 12	fp448.AddSub(x, z)
 13	fp448.Sqr(x, x)
 14	fp448.Sqr(z, z)
 15	fp448.Sub(t0, x, z)
 16	mulA24Generic(t1, t0)
 17	fp448.Add(t1, t1, z)
 18	fp448.Mul(x, x, z)
 19	fp448.Mul(z, t0, t1)
 20}
 21
 22func diffAddGeneric(w *[5]fp448.Elt, b uint) {
 23	mu, x1, z1, x2, z2 := &w[0], &w[1], &w[2], &w[3], &w[4]
 24	fp448.Cswap(x1, x2, b)
 25	fp448.Cswap(z1, z2, b)
 26	fp448.AddSub(x1, z1)
 27	fp448.Mul(z1, z1, mu)
 28	fp448.AddSub(x1, z1)
 29	fp448.Sqr(x1, x1)
 30	fp448.Sqr(z1, z1)
 31	fp448.Mul(x1, x1, z2)
 32	fp448.Mul(z1, z1, x2)
 33}
 34
 35func ladderStepGeneric(w *[5]fp448.Elt, b uint) {
 36	x1, x2, z2, x3, z3 := &w[0], &w[1], &w[2], &w[3], &w[4]
 37	t0 := &fp448.Elt{}
 38	t1 := &fp448.Elt{}
 39	fp448.AddSub(x2, z2)
 40	fp448.AddSub(x3, z3)
 41	fp448.Mul(t0, x2, z3)
 42	fp448.Mul(t1, x3, z2)
 43	fp448.AddSub(t0, t1)
 44	fp448.Cmov(x2, x3, b)
 45	fp448.Cmov(z2, z3, b)
 46	fp448.Sqr(x3, t0)
 47	fp448.Sqr(z3, t1)
 48	fp448.Mul(z3, x1, z3)
 49	fp448.Sqr(x2, x2)
 50	fp448.Sqr(z2, z2)
 51	fp448.Sub(t0, x2, z2)
 52	mulA24Generic(t1, t0)
 53	fp448.Add(t1, t1, z2)
 54	fp448.Mul(x2, x2, z2)
 55	fp448.Mul(z2, t0, t1)
 56}
 57
 58func mulA24Generic(z, x *fp448.Elt) {
 59	const A24 = 39082
 60	const n = 8
 61	var xx [7]uint64
 62	for i := range xx {
 63		xx[i] = binary.LittleEndian.Uint64(x[i*n : (i+1)*n])
 64	}
 65	h0, l0 := bits.Mul64(xx[0], A24)
 66	h1, l1 := bits.Mul64(xx[1], A24)
 67	h2, l2 := bits.Mul64(xx[2], A24)
 68	h3, l3 := bits.Mul64(xx[3], A24)
 69	h4, l4 := bits.Mul64(xx[4], A24)
 70	h5, l5 := bits.Mul64(xx[5], A24)
 71	h6, l6 := bits.Mul64(xx[6], A24)
 72
 73	l1, c0 := bits.Add64(h0, l1, 0)
 74	l2, c1 := bits.Add64(h1, l2, c0)
 75	l3, c2 := bits.Add64(h2, l3, c1)
 76	l4, c3 := bits.Add64(h3, l4, c2)
 77	l5, c4 := bits.Add64(h4, l5, c3)
 78	l6, c5 := bits.Add64(h5, l6, c4)
 79	l7, _ := bits.Add64(h6, 0, c5)
 80
 81	l0, c0 = bits.Add64(l0, l7, 0)
 82	l1, c1 = bits.Add64(l1, 0, c0)
 83	l2, c2 = bits.Add64(l2, 0, c1)
 84	l3, c3 = bits.Add64(l3, l7<<32, c2)
 85	l4, c4 = bits.Add64(l4, 0, c3)
 86	l5, c5 = bits.Add64(l5, 0, c4)
 87	l6, l7 = bits.Add64(l6, 0, c5)
 88
 89	xx[0], c0 = bits.Add64(l0, l7, 0)
 90	xx[1], c1 = bits.Add64(l1, 0, c0)
 91	xx[2], c2 = bits.Add64(l2, 0, c1)
 92	xx[3], c3 = bits.Add64(l3, l7<<32, c2)
 93	xx[4], c4 = bits.Add64(l4, 0, c3)
 94	xx[5], c5 = bits.Add64(l5, 0, c4)
 95	xx[6], _ = bits.Add64(l6, 0, c5)
 96
 97	for i := range xx {
 98		binary.LittleEndian.PutUint64(z[i*n:(i+1)*n], xx[i])
 99	}
100}