gmsm/sm9/bn256/gfp_invert.go

// Code generated by addchain. DO NOT EDIT.
package bn256

// Invert sets e = 1/x, and returns e.
//
// If x == 0, Invert returns e = 0.
func (e *gfP) Invert(x *gfP) *gfP {
	// Inversion is implemented as exponentiation with exponent p − 2.
	// The sequence of 56 multiplications and 250 squarings is derived from the
	// following addition chain generated with github.com/mmcloughlin/addchain v0.4.0.
	//
	//	_10       = 2*1
	//	_100      = 2*_10
	//	_110      = _10 + _100
	//	_1010     = _100 + _110
	//	_1011     = 1 + _1010
	//	_1101     = _10 + _1011
	//	_10000    = _110 + _1010
	//	_10101    = _1010 + _1011
	//	_11011    = _110 + _10101
	//	_11101    = _10 + _11011
	//	_11111    = _10 + _11101
	//	_101001   = _1010 + _11111
	//	_101011   = _10 + _101001
	//	_111011   = _10000 + _101011
	//	_1000101  = _1010 + _111011
	//	_1001111  = _1010 + _1000101
	//	_1010001  = _10 + _1001111
	//	_1011011  = _1010 + _1010001
	//	_1011101  = _10 + _1011011
	//	_1011111  = _10 + _1011101
	//	_1100011  = _100 + _1011111
	//	_1101001  = _110 + _1100011
	//	_1101101  = _100 + _1101001
	//	_1101111  = _10 + _1101101
	//	_1110101  = _110 + _1101111
	//	_1111011  = _110 + _1110101
	//	_10110110 = _111011 + _1111011
	//	i72       = ((_10110110 << 2 + 1) << 33 + _10101) << 8
	//	i94       = ((_11101 + i72) << 9 + _1101111) << 10 + _1110101
	//	i116      = ((2*i94 + 1) << 14 + _1110101) << 5
	//	i129      = 2*((_1101 + i116) << 9 + _1111011 + _100)
	//	i146      = ((1 + i129) << 5 + _1011) << 9 + _111011
	//	i174      = ((i146 << 8 + _11101) << 9 + _101001) << 9
	//	i194      = ((_11111 + i174) << 8 + _101001) << 9 + _1101001
	//	i220      = ((i194 << 8 + _1100011) << 8 + _1001111) << 8
	//	i237      = ((_1011101 + i220) << 7 + _1101101) << 7 + _1011111
	//	i260      = ((i237 << 8 + _101011) << 6 + _11111) << 7
	//	i279      = ((_11011 + i260) << 9 + _1001111) << 7 + _1100011
	//	i305      = ((i279 << 8 + _1010001) << 8 + _1000101) << 8
	//	return      _1111011 + i305
	//
	var z = new(gfP).Set(e)
	var t0 = new(gfP)
	var t1 = new(gfP)
	var t2 = new(gfP)
	var t3 = new(gfP)
	var t4 = new(gfP)
	var t5 = new(gfP)
	var t6 = new(gfP)
	var t7 = new(gfP)
	var t8 = new(gfP)
	var t9 = new(gfP)
	var t10 = new(gfP)
	var t11 = new(gfP)
	var t12 = new(gfP)
	var t13 = new(gfP)
	var t14 = new(gfP)
	var t15 = new(gfP)
	var t16 = new(gfP)
	var t17 = new(gfP)
	var t18 = new(gfP)
	var t19 = new(gfP)
	var t20 = new(gfP)

	t17.Square(x)
	t15.Square(t17)
	z.Mul(t17, t15)
	t2.Mul(t15, z)
	t14.Mul(x, t2)
	t16.Mul(t17, t14)
	t0.Mul(z, t2)
	t19.Mul(t2, t14)
	t4.Mul(z, t19)
	t12.Mul(t17, t4)
	t5.Mul(t17, t12)
	t11.Mul(t2, t5)
	t6.Mul(t17, t11)
	t13.Mul(t0, t6)
	t0.Mul(t2, t13)
	t3.Mul(t2, t0)
	t1.Mul(t17, t3)
	t2.Mul(t2, t1)
	t9.Mul(t17, t2)
	t7.Mul(t17, t9)
	t2.Mul(t15, t7)
	t10.Mul(z, t2)
	t8.Mul(t15, t10)
	t18.Mul(t17, t8)
	t17.Mul(z, t18)
	z.Mul(z, t17)
	t20.Mul(t13, z)
	for s := 0; s < 2; s++ {
		t20.Square(t20)
	}
	t20.Mul(x, t20)
	for s := 0; s < 33; s++ {
		t20.Square(t20)
	}
	t19.Mul(t19, t20)
	for s := 0; s < 8; s++ {
		t19.Square(t19)
	}
	t19.Mul(t12, t19)
	for s := 0; s < 9; s++ {
		t19.Square(t19)
	}
	t18.Mul(t18, t19)
	for s := 0; s < 10; s++ {
		t18.Square(t18)
	}
	t18.Mul(t17, t18)
	t18.Square(t18)
	t18.Mul(x, t18)
	for s := 0; s < 14; s++ {
		t18.Square(t18)
	}
	t17.Mul(t17, t18)
	for s := 0; s < 5; s++ {
		t17.Square(t17)
	}
	t16.Mul(t16, t17)
	for s := 0; s < 9; s++ {
		t16.Square(t16)
	}
	t16.Mul(z, t16)
	t15.Mul(t15, t16)
	t15.Square(t15)
	t15.Mul(x, t15)
	for s := 0; s < 5; s++ {
		t15.Square(t15)
	}
	t14.Mul(t14, t15)
	for s := 0; s < 9; s++ {
		t14.Square(t14)
	}
	t13.Mul(t13, t14)
	for s := 0; s < 8; s++ {
		t13.Square(t13)
	}
	t12.Mul(t12, t13)
	for s := 0; s < 9; s++ {
		t12.Square(t12)
	}
	t12.Mul(t11, t12)
	for s := 0; s < 9; s++ {
		t12.Square(t12)
	}
	t12.Mul(t5, t12)
	for s := 0; s < 8; s++ {
		t12.Square(t12)
	}
	t11.Mul(t11, t12)
	for s := 0; s < 9; s++ {
		t11.Square(t11)
	}
	t10.Mul(t10, t11)
	for s := 0; s < 8; s++ {
		t10.Square(t10)
	}
	t10.Mul(t2, t10)
	for s := 0; s < 8; s++ {
		t10.Square(t10)
	}
	t10.Mul(t3, t10)
	for s := 0; s < 8; s++ {
		t10.Square(t10)
	}
	t9.Mul(t9, t10)
	for s := 0; s < 7; s++ {
		t9.Square(t9)
	}
	t8.Mul(t8, t9)
	for s := 0; s < 7; s++ {
		t8.Square(t8)
	}
	t7.Mul(t7, t8)
	for s := 0; s < 8; s++ {
		t7.Square(t7)
	}
	t6.Mul(t6, t7)
	for s := 0; s < 6; s++ {
		t6.Square(t6)
	}
	t5.Mul(t5, t6)
	for s := 0; s < 7; s++ {
		t5.Square(t5)
	}
	t4.Mul(t4, t5)
	for s := 0; s < 9; s++ {
		t4.Square(t4)
	}
	t3.Mul(t3, t4)
	for s := 0; s < 7; s++ {
		t3.Square(t3)
	}
	t2.Mul(t2, t3)
	for s := 0; s < 8; s++ {
		t2.Square(t2)
	}
	t1.Mul(t1, t2)
	for s := 0; s < 8; s++ {
		t1.Square(t1)
	}
	t0.Mul(t0, t1)
	for s := 0; s < 8; s++ {
		t0.Square(t0)
	}
	z.Mul(z, t0)
	return e.Set(z)
}