// prime order elliptic curves" (https://eprint.iacr.org/2015/1060), §A.2.

	t0 := new(fiat.P256Element).Mul(p1.x, p2.x)  // t0 := X1 * X2
	t1 := new(fiat.P256Element).Mul(p1.y, p2.y)  // t1 := Y1 * Y2
	t2 := new(fiat.P256Element).Mul(p1.z, p2.z)  // t2 := Z1 * Z2
	t3 := new(fiat.P256Element).Add(p1.x, p1.y)  // t3 := X1 + Y1
	t4 := new(fiat.P256Element).Add(p2.x, p2.y)  // t4 := X2 + Y2
	t3.Mul(t3, t4)                               // t3 := t3 * t4

	"math/bits"
	"runtime"
	"unsafe"
)

// p256Element is a P-256 base field element in [0, P-1] in the Montgomery
// domain (with R 2²⁵⁶) as four limbs in little-endian order value.
type p256Element [4]uint64

// p256One is one in the Montgomery domain.
var p256One = p256Element{0x0000000000000001, 0xffffffff00000000,
	0xffffffffffffffff, 0x00000000fffffffe}

var p256Zero = p256Element{}

	JMP ·p256BigToLittle(SB)
/* ---------------------------------------*/
// func p256LittleToBig(res *[32]byte, in *p256Element)
TEXT ·p256LittleToBig(SB),NOSPLIT,$0
	JMP ·p256BigToLittle(SB)
/* ---------------------------------------*/
// func p256BigToLittle(res *p256Element, in *[32]byte)
TEXT ·p256BigToLittle(SB),NOSPLIT,$0
	MOVQ res+0(FP), res_ptr
	MOVQ in+8(FP), x_ptr

	MOVQ (8*0)(x_ptr), acc0

	JMP	·p256BigToLittle(SB)
/* ---------------------------------------*/
// func p256LittleToBig(res *[32]byte, in *p256Element)
TEXT ·p256LittleToBig(SB),NOSPLIT,$0
	JMP	·p256BigToLittle(SB)
/* ---------------------------------------*/
// func p256BigToLittle(res *p256Element, in *[32]byte)
TEXT ·p256BigToLittle(SB),NOSPLIT,$0
	MOVD	res+0(FP), res_ptr
	MOVD	in+8(FP), a_ptr

	LDP	0*16(a_ptr), (acc0, acc1)

	Params    *elliptic.CurveParams
	BuildTags string
}{
	{
		P:       "P224",
		Element: "fiat.P224Element",
		Params:  elliptic.P224().Params(),
	},
	{
		P:         "P256",
		Element:   "fiat.P256Element",
		Params:    elliptic.P256().Params(),
		BuildTags: "(!amd64 && !arm64 && !ppc64le && !s390x) || purego",
	},
	{
		P:       "P384",
		Element: "fiat.P384Element",
		Params:  elliptic.P384().Params(),
	},