LXVD2X (R19)(P1ptr), Y0
	LXVD2X (R20)(P1ptr), Y1
	XXPERMDI Y0, Y0, $2, Y0
	XXPERMDI Y1, Y1, $2, Y1

	CALL p256MulInternal<>(SB)

	// Leave T0, T1 as is.
	XXPERMDI T0, T0, $2, TT0
	XXPERMDI T1, T1, $2, TT1
	STXVD2X TT0, (R19)(P3ptr)
	STXVD2X TT1, (R20)(P3ptr)

	// X-  ; Y=X ; MUL; T-    // Y3 = Y3²
	VOR  X0, X0, Y0
	VOR  X1, X1, Y1
	CALL p256MulInternal<>(SB)

#define X0    V0
#define X1    V1
#define Y0    V2
#define Y1    V3

TEXT p256SqrInternal<>(SB), NOFRAME|NOSPLIT, $0
	VLR X0, Y0
	VLR X1, Y1
	BR  p256MulInternal<>(SB)

#undef X0
#undef X1
#undef Y0
#undef Y1

#define p256SubInternal(T1, T0, X1, X0, Y1, Y0) \
	VZERO   ZER                \
	VSCBIQ  Y0, X0, CAR1       \
	VSQ     Y0, X0, T0         \
	VSBCBIQ X1, Y1, CAR1, SEL1 \

	} {
		for i := range [8]int{} {
			x0, y0 := test.x, test.y
			if i&1 != 0 {
				x0 = -x0
			}
			if i&2 != 0 {
				y0 = -y0
			}
			if i&4 != 0 {
				x0, y0 = y0, x0
			}

			x := NewFloat(x0)
			y := NewFloat(y0)
			z := new(Float).SetPrec(53)

			z.Mul(x, y)
			got, _ := z.Float64()
			want := x0 * y0
			if got != want {

    grad_outputs->push_back(dx);
    auto dy =
        MatMul(scope, y0, y1, MatMul::TransposeA(adj_y0).TransposeB(adj_y1));
    grad_outputs->push_back(dy);
  } else {
    auto dx = BatchMatMulV3(scope, x0, x1, x_data_type,
                            BatchMatMulV3::AdjX(adj_x0).AdjY(adj_x1));
    grad_outputs->push_back(dx);
    auto dy = BatchMatMulV3(scope, y0, y1, y_data_type,

	return metrics.PriorityLevelExecutionSeatsGaugeVec.NewForLabelValuesSafe(0, 1, []string{"test"})
}

func float64close(x, y float64) bool {
	x0 := float64NaNTo0(x)
	y0 := float64NaNTo0(y)
	diff := math.Abs(x0 - y0)
	den := math.Max(math.Abs(x0), math.Abs(y0))
	return den == 0 || diff/den < 1e-10
}

func uint64max(a, b uint64) uint64 {
	if b > a {
		return b
	}
	return a
}

	y := new(Int)

	if a.Sign() <= 0 || b.Sign() <= 0 {
		return true // can only test positive arguments
	}

	d := new(Int).lehmerGCD(x, y, a, b)
	d0, x0, y0 := euclidExtGCD(a, b)

	return d.Cmp(d0) == 0 && x.Cmp(x0) == 0 && y.Cmp(y0) == 0
}

var gcdTests = []struct {
	d, x, y, a, b string
}{
	// a <= 0 || b <= 0
	{"0", "0", "0", "0", "0"},
	{"7", "0", "1", "0", "7"},