Maksimov and Kolovsky, Equation (3)

Percentage Accurate: 73.6% → 99.7%
Time: 4.9s
Alternatives: 7
Speedup: 0.3×

Specification

?
\[\begin{array}{l} \\ \begin{array}{l} t_0 := \cos \left(\frac{K}{2}\right)\\ \left(\left(-2 \cdot J\right) \cdot t\_0\right) \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot t\_0}\right)}^{2}} \end{array} \end{array} \]
(FPCore (J K U)
 :precision binary64
 (let* ((t_0 (cos (/ K 2.0))))
   (* (* (* -2.0 J) t_0) (sqrt (+ 1.0 (pow (/ U (* (* 2.0 J) t_0)) 2.0))))))
double code(double J, double K, double U) {
	double t_0 = cos((K / 2.0));
	return ((-2.0 * J) * t_0) * sqrt((1.0 + pow((U / ((2.0 * J) * t_0)), 2.0)));
}
module fmin_fmax_functions
    implicit none
    private
    public fmax
    public fmin

    interface fmax
        module procedure fmax88
        module procedure fmax44
        module procedure fmax84
        module procedure fmax48
    end interface
    interface fmin
        module procedure fmin88
        module procedure fmin44
        module procedure fmin84
        module procedure fmin48
    end interface
contains
    real(8) function fmax88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(4) function fmax44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(8) function fmax84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, max(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmax48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), max(dble(x), y), y /= y), x /= x)
    end function
    real(8) function fmin88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(4) function fmin44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(8) function fmin84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, min(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmin48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), min(dble(x), y), y /= y), x /= x)
    end function
end module

real(8) function code(j, k, u)
use fmin_fmax_functions
    real(8), intent (in) :: j
    real(8), intent (in) :: k
    real(8), intent (in) :: u
    real(8) :: t_0
    t_0 = cos((k / 2.0d0))
    code = (((-2.0d0) * j) * t_0) * sqrt((1.0d0 + ((u / ((2.0d0 * j) * t_0)) ** 2.0d0)))
end function
public static double code(double J, double K, double U) {
	double t_0 = Math.cos((K / 2.0));
	return ((-2.0 * J) * t_0) * Math.sqrt((1.0 + Math.pow((U / ((2.0 * J) * t_0)), 2.0)));
}
def code(J, K, U):
	t_0 = math.cos((K / 2.0))
	return ((-2.0 * J) * t_0) * math.sqrt((1.0 + math.pow((U / ((2.0 * J) * t_0)), 2.0)))
function code(J, K, U)
	t_0 = cos(Float64(K / 2.0))
	return Float64(Float64(Float64(-2.0 * J) * t_0) * sqrt(Float64(1.0 + (Float64(U / Float64(Float64(2.0 * J) * t_0)) ^ 2.0))))
end
function tmp = code(J, K, U)
	t_0 = cos((K / 2.0));
	tmp = ((-2.0 * J) * t_0) * sqrt((1.0 + ((U / ((2.0 * J) * t_0)) ^ 2.0)));
end
code[J_, K_, U_] := Block[{t$95$0 = N[Cos[N[(K / 2.0), $MachinePrecision]], $MachinePrecision]}, N[(N[(N[(-2.0 * J), $MachinePrecision] * t$95$0), $MachinePrecision] * N[Sqrt[N[(1.0 + N[Power[N[(U / N[(N[(2.0 * J), $MachinePrecision] * t$95$0), $MachinePrecision]), $MachinePrecision], 2.0], $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \cos \left(\frac{K}{2}\right)\\
\left(\left(-2 \cdot J\right) \cdot t\_0\right) \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot t\_0}\right)}^{2}}
\end{array}
\end{array}

Sampling outcomes in binary64 precision:

Local Percentage Accuracy vs ?

The average percentage accuracy by input value. Horizontal axis shows value of an input variable; the variable is choosen in the title. Vertical axis is accuracy; higher is better. Red represent the original program, while blue represents Herbie's suggestion. These can be toggled with buttons below the plot. The line is an average while dots represent individual samples.

Accuracy vs Speed?

Herbie found 7 alternatives:

AlternativeAccuracySpeedup
The accuracy (vertical axis) and speed (horizontal axis) of each alternatives. Up and to the right is better. The red square shows the initial program, and each blue circle shows an alternative.The line shows the best available speed-accuracy tradeoffs.

Initial Program: 73.6% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \cos \left(\frac{K}{2}\right)\\ \left(\left(-2 \cdot J\right) \cdot t\_0\right) \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot t\_0}\right)}^{2}} \end{array} \end{array} \]
(FPCore (J K U)
 :precision binary64
 (let* ((t_0 (cos (/ K 2.0))))
   (* (* (* -2.0 J) t_0) (sqrt (+ 1.0 (pow (/ U (* (* 2.0 J) t_0)) 2.0))))))
double code(double J, double K, double U) {
	double t_0 = cos((K / 2.0));
	return ((-2.0 * J) * t_0) * sqrt((1.0 + pow((U / ((2.0 * J) * t_0)), 2.0)));
}
module fmin_fmax_functions
    implicit none
    private
    public fmax
    public fmin

    interface fmax
        module procedure fmax88
        module procedure fmax44
        module procedure fmax84
        module procedure fmax48
    end interface
    interface fmin
        module procedure fmin88
        module procedure fmin44
        module procedure fmin84
        module procedure fmin48
    end interface
contains
    real(8) function fmax88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(4) function fmax44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(8) function fmax84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, max(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmax48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), max(dble(x), y), y /= y), x /= x)
    end function
    real(8) function fmin88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(4) function fmin44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(8) function fmin84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, min(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmin48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), min(dble(x), y), y /= y), x /= x)
    end function
end module

real(8) function code(j, k, u)
use fmin_fmax_functions
    real(8), intent (in) :: j
    real(8), intent (in) :: k
    real(8), intent (in) :: u
    real(8) :: t_0
    t_0 = cos((k / 2.0d0))
    code = (((-2.0d0) * j) * t_0) * sqrt((1.0d0 + ((u / ((2.0d0 * j) * t_0)) ** 2.0d0)))
end function
public static double code(double J, double K, double U) {
	double t_0 = Math.cos((K / 2.0));
	return ((-2.0 * J) * t_0) * Math.sqrt((1.0 + Math.pow((U / ((2.0 * J) * t_0)), 2.0)));
}
def code(J, K, U):
	t_0 = math.cos((K / 2.0))
	return ((-2.0 * J) * t_0) * math.sqrt((1.0 + math.pow((U / ((2.0 * J) * t_0)), 2.0)))
function code(J, K, U)
	t_0 = cos(Float64(K / 2.0))
	return Float64(Float64(Float64(-2.0 * J) * t_0) * sqrt(Float64(1.0 + (Float64(U / Float64(Float64(2.0 * J) * t_0)) ^ 2.0))))
end
function tmp = code(J, K, U)
	t_0 = cos((K / 2.0));
	tmp = ((-2.0 * J) * t_0) * sqrt((1.0 + ((U / ((2.0 * J) * t_0)) ^ 2.0)));
end
code[J_, K_, U_] := Block[{t$95$0 = N[Cos[N[(K / 2.0), $MachinePrecision]], $MachinePrecision]}, N[(N[(N[(-2.0 * J), $MachinePrecision] * t$95$0), $MachinePrecision] * N[Sqrt[N[(1.0 + N[Power[N[(U / N[(N[(2.0 * J), $MachinePrecision] * t$95$0), $MachinePrecision]), $MachinePrecision], 2.0], $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \cos \left(\frac{K}{2}\right)\\
\left(\left(-2 \cdot J\right) \cdot t\_0\right) \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot t\_0}\right)}^{2}}
\end{array}
\end{array}

Alternative 1: 99.7% accurate, 0.3× speedup?

\[\begin{array}{l} U_m = \left|U\right| \\ \begin{array}{l} t_0 := \cos \left(0.5 \cdot K\right)\\ t_1 := \cos \left(\frac{K}{2}\right)\\ t_2 := \left(\left(-2 \cdot J\right) \cdot t\_1\right) \cdot \sqrt{1 + {\left(\frac{U\_m}{\left(2 \cdot J\right) \cdot t\_1}\right)}^{2}}\\ \mathbf{if}\;t\_2 \leq -\infty:\\ \;\;\;\;\mathsf{fma}\left(\frac{J \cdot J}{U\_m}, -2, -U\_m\right)\\ \mathbf{elif}\;t\_2 \leq 4 \cdot 10^{+306}:\\ \;\;\;\;\left(\left(-2 \cdot J\right) \cdot t\_0\right) \cdot \sqrt{1 + {\left(\frac{U\_m}{\left(J + J\right) \cdot t\_0}\right)}^{2}}\\ \mathbf{else}:\\ \;\;\;\;U\_m\\ \end{array} \end{array} \]
U_m = (fabs.f64 U)
(FPCore (J K U_m)
 :precision binary64
 (let* ((t_0 (cos (* 0.5 K)))
        (t_1 (cos (/ K 2.0)))
        (t_2
         (*
          (* (* -2.0 J) t_1)
          (sqrt (+ 1.0 (pow (/ U_m (* (* 2.0 J) t_1)) 2.0))))))
   (if (<= t_2 (- INFINITY))
     (fma (/ (* J J) U_m) -2.0 (- U_m))
     (if (<= t_2 4e+306)
       (* (* (* -2.0 J) t_0) (sqrt (+ 1.0 (pow (/ U_m (* (+ J J) t_0)) 2.0))))
       U_m))))
U_m = fabs(U);
double code(double J, double K, double U_m) {
	double t_0 = cos((0.5 * K));
	double t_1 = cos((K / 2.0));
	double t_2 = ((-2.0 * J) * t_1) * sqrt((1.0 + pow((U_m / ((2.0 * J) * t_1)), 2.0)));
	double tmp;
	if (t_2 <= -((double) INFINITY)) {
		tmp = fma(((J * J) / U_m), -2.0, -U_m);
	} else if (t_2 <= 4e+306) {
		tmp = ((-2.0 * J) * t_0) * sqrt((1.0 + pow((U_m / ((J + J) * t_0)), 2.0)));
	} else {
		tmp = U_m;
	}
	return tmp;
}
U_m = abs(U)
function code(J, K, U_m)
	t_0 = cos(Float64(0.5 * K))
	t_1 = cos(Float64(K / 2.0))
	t_2 = Float64(Float64(Float64(-2.0 * J) * t_1) * sqrt(Float64(1.0 + (Float64(U_m / Float64(Float64(2.0 * J) * t_1)) ^ 2.0))))
	tmp = 0.0
	if (t_2 <= Float64(-Inf))
		tmp = fma(Float64(Float64(J * J) / U_m), -2.0, Float64(-U_m));
	elseif (t_2 <= 4e+306)
		tmp = Float64(Float64(Float64(-2.0 * J) * t_0) * sqrt(Float64(1.0 + (Float64(U_m / Float64(Float64(J + J) * t_0)) ^ 2.0))));
	else
		tmp = U_m;
	end
	return tmp
end
U_m = N[Abs[U], $MachinePrecision]
code[J_, K_, U$95$m_] := Block[{t$95$0 = N[Cos[N[(0.5 * K), $MachinePrecision]], $MachinePrecision]}, Block[{t$95$1 = N[Cos[N[(K / 2.0), $MachinePrecision]], $MachinePrecision]}, Block[{t$95$2 = N[(N[(N[(-2.0 * J), $MachinePrecision] * t$95$1), $MachinePrecision] * N[Sqrt[N[(1.0 + N[Power[N[(U$95$m / N[(N[(2.0 * J), $MachinePrecision] * t$95$1), $MachinePrecision]), $MachinePrecision], 2.0], $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]}, If[LessEqual[t$95$2, (-Infinity)], N[(N[(N[(J * J), $MachinePrecision] / U$95$m), $MachinePrecision] * -2.0 + (-U$95$m)), $MachinePrecision], If[LessEqual[t$95$2, 4e+306], N[(N[(N[(-2.0 * J), $MachinePrecision] * t$95$0), $MachinePrecision] * N[Sqrt[N[(1.0 + N[Power[N[(U$95$m / N[(N[(J + J), $MachinePrecision] * t$95$0), $MachinePrecision]), $MachinePrecision], 2.0], $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision], U$95$m]]]]]
\begin{array}{l}
U_m = \left|U\right|

\\
\begin{array}{l}
t_0 := \cos \left(0.5 \cdot K\right)\\
t_1 := \cos \left(\frac{K}{2}\right)\\
t_2 := \left(\left(-2 \cdot J\right) \cdot t\_1\right) \cdot \sqrt{1 + {\left(\frac{U\_m}{\left(2 \cdot J\right) \cdot t\_1}\right)}^{2}}\\
\mathbf{if}\;t\_2 \leq -\infty:\\
\;\;\;\;\mathsf{fma}\left(\frac{J \cdot J}{U\_m}, -2, -U\_m\right)\\

\mathbf{elif}\;t\_2 \leq 4 \cdot 10^{+306}:\\
\;\;\;\;\left(\left(-2 \cdot J\right) \cdot t\_0\right) \cdot \sqrt{1 + {\left(\frac{U\_m}{\left(J + J\right) \cdot t\_0}\right)}^{2}}\\

\mathbf{else}:\\
\;\;\;\;U\_m\\


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if (*.f64 (*.f64 (*.f64 #s(literal -2 binary64) J) (cos.f64 (/.f64 K #s(literal 2 binary64)))) (sqrt.f64 (+.f64 #s(literal 1 binary64) (pow.f64 (/.f64 U (*.f64 (*.f64 #s(literal 2 binary64) J) (cos.f64 (/.f64 K #s(literal 2 binary64))))) #s(literal 2 binary64))))) < -inf.0

    1. Initial program 8.3%

      \[\left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)}\right)}^{2}} \]
    2. Add Preprocessing
    3. Taylor expanded in K around 0

      \[\leadsto \color{blue}{-2 \cdot \left(J \cdot \sqrt{1 + \frac{1}{4} \cdot \frac{{U}^{2}}{{J}^{2}}}\right)} \]
    4. Step-by-step derivation
      1. associate-*r*N/A

        \[\leadsto \left(-2 \cdot J\right) \cdot \color{blue}{\sqrt{1 + \frac{1}{4} \cdot \frac{{U}^{2}}{{J}^{2}}}} \]
      2. lower-*.f64N/A

        \[\leadsto \left(-2 \cdot J\right) \cdot \color{blue}{\sqrt{1 + \frac{1}{4} \cdot \frac{{U}^{2}}{{J}^{2}}}} \]
      3. *-commutativeN/A

        \[\leadsto \left(J \cdot -2\right) \cdot \sqrt{\color{blue}{1 + \frac{1}{4} \cdot \frac{{U}^{2}}{{J}^{2}}}} \]
      4. lower-*.f64N/A

        \[\leadsto \left(J \cdot -2\right) \cdot \sqrt{\color{blue}{1 + \frac{1}{4} \cdot \frac{{U}^{2}}{{J}^{2}}}} \]
      5. lower-sqrt.f64N/A

        \[\leadsto \left(J \cdot -2\right) \cdot \sqrt{1 + \frac{1}{4} \cdot \frac{{U}^{2}}{{J}^{2}}} \]
      6. +-commutativeN/A

        \[\leadsto \left(J \cdot -2\right) \cdot \sqrt{\frac{1}{4} \cdot \frac{{U}^{2}}{{J}^{2}} + 1} \]
      7. *-commutativeN/A

        \[\leadsto \left(J \cdot -2\right) \cdot \sqrt{\frac{{U}^{2}}{{J}^{2}} \cdot \frac{1}{4} + 1} \]
      8. lower-fma.f64N/A

        \[\leadsto \left(J \cdot -2\right) \cdot \sqrt{\mathsf{fma}\left(\frac{{U}^{2}}{{J}^{2}}, \frac{1}{4}, 1\right)} \]
      9. lower-/.f64N/A

        \[\leadsto \left(J \cdot -2\right) \cdot \sqrt{\mathsf{fma}\left(\frac{{U}^{2}}{{J}^{2}}, \frac{1}{4}, 1\right)} \]
      10. unpow2N/A

        \[\leadsto \left(J \cdot -2\right) \cdot \sqrt{\mathsf{fma}\left(\frac{U \cdot U}{{J}^{2}}, \frac{1}{4}, 1\right)} \]
      11. lower-*.f64N/A

        \[\leadsto \left(J \cdot -2\right) \cdot \sqrt{\mathsf{fma}\left(\frac{U \cdot U}{{J}^{2}}, \frac{1}{4}, 1\right)} \]
      12. unpow2N/A

        \[\leadsto \left(J \cdot -2\right) \cdot \sqrt{\mathsf{fma}\left(\frac{U \cdot U}{J \cdot J}, \frac{1}{4}, 1\right)} \]
      13. lower-*.f647.0

        \[\leadsto \left(J \cdot -2\right) \cdot \sqrt{\mathsf{fma}\left(\frac{U \cdot U}{J \cdot J}, 0.25, 1\right)} \]
    5. Applied rewrites7.0%

      \[\leadsto \color{blue}{\left(J \cdot -2\right) \cdot \sqrt{\mathsf{fma}\left(\frac{U \cdot U}{J \cdot J}, 0.25, 1\right)}} \]
    6. Taylor expanded in J around 0

      \[\leadsto -2 \cdot \frac{{J}^{2}}{U} + \color{blue}{-1 \cdot U} \]
    7. Step-by-step derivation
      1. *-commutativeN/A

        \[\leadsto \frac{{J}^{2}}{U} \cdot -2 + -1 \cdot U \]
      2. lower-fma.f64N/A

        \[\leadsto \mathsf{fma}\left(\frac{{J}^{2}}{U}, -2, -1 \cdot U\right) \]
      3. lower-/.f64N/A

        \[\leadsto \mathsf{fma}\left(\frac{{J}^{2}}{U}, -2, -1 \cdot U\right) \]
      4. pow2N/A

        \[\leadsto \mathsf{fma}\left(\frac{J \cdot J}{U}, -2, -1 \cdot U\right) \]
      5. lift-*.f64N/A

        \[\leadsto \mathsf{fma}\left(\frac{J \cdot J}{U}, -2, -1 \cdot U\right) \]
      6. mul-1-negN/A

        \[\leadsto \mathsf{fma}\left(\frac{J \cdot J}{U}, -2, \mathsf{neg}\left(U\right)\right) \]
      7. lift-neg.f6463.6

        \[\leadsto \mathsf{fma}\left(\frac{J \cdot J}{U}, -2, -U\right) \]
    8. Applied rewrites63.6%

      \[\leadsto \mathsf{fma}\left(\frac{J \cdot J}{U}, \color{blue}{-2}, -U\right) \]

    if -inf.0 < (*.f64 (*.f64 (*.f64 #s(literal -2 binary64) J) (cos.f64 (/.f64 K #s(literal 2 binary64)))) (sqrt.f64 (+.f64 #s(literal 1 binary64) (pow.f64 (/.f64 U (*.f64 (*.f64 #s(literal 2 binary64) J) (cos.f64 (/.f64 K #s(literal 2 binary64))))) #s(literal 2 binary64))))) < 4.00000000000000007e306

    1. Initial program 99.8%

      \[\left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)}\right)}^{2}} \]
    2. Add Preprocessing
    3. Taylor expanded in K around 0

      \[\leadsto \left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \color{blue}{\left(\frac{1}{2} \cdot K\right)}}\right)}^{2}} \]
    4. Step-by-step derivation
      1. lower-*.f6499.8

        \[\leadsto \left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \left(0.5 \cdot \color{blue}{K}\right)}\right)}^{2}} \]
    5. Applied rewrites99.8%

      \[\leadsto \left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \color{blue}{\left(0.5 \cdot K\right)}}\right)}^{2}} \]
    6. Taylor expanded in K around inf

      \[\leadsto \left(\left(-2 \cdot J\right) \cdot \color{blue}{\cos \left(\frac{1}{2} \cdot K\right)}\right) \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \left(\frac{1}{2} \cdot K\right)}\right)}^{2}} \]
    7. Step-by-step derivation
      1. sin-+PI/2-revN/A

        \[\leadsto \left(\left(-2 \cdot J\right) \cdot \cos \color{blue}{\left(\frac{1}{2} \cdot K\right)}\right) \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \left(\frac{1}{2} \cdot K\right)}\right)}^{2}} \]
      2. lift-/.f64N/A

        \[\leadsto \left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{1}{2} \cdot K\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \left(\frac{1}{2} \cdot K\right)}\right)}^{2}} \]
      3. lift-PI.f64N/A

        \[\leadsto \left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{1}{2} \cdot K\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \left(\frac{1}{2} \cdot K\right)}\right)}^{2}} \]
      4. sin-sum-revN/A

        \[\leadsto \left(\left(-2 \cdot J\right) \cdot \cos \color{blue}{\left(\frac{1}{2} \cdot K\right)}\right) \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \left(\frac{1}{2} \cdot K\right)}\right)}^{2}} \]
      5. lift-PI.f64N/A

        \[\leadsto \left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{1}{2} \cdot K\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \left(\frac{1}{2} \cdot K\right)}\right)}^{2}} \]
      6. lift-/.f64N/A

        \[\leadsto \left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{1}{2} \cdot K\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \left(\frac{1}{2} \cdot K\right)}\right)}^{2}} \]
      7. lift-PI.f64N/A

        \[\leadsto \left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{1}{2} \cdot K\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \left(\frac{1}{2} \cdot K\right)}\right)}^{2}} \]
      8. lift-/.f64N/A

        \[\leadsto \left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{1}{2} \cdot K\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \left(\frac{1}{2} \cdot K\right)}\right)}^{2}} \]
      9. lift-cos.f64N/A

        \[\leadsto \left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{1}{2} \cdot K\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \left(\frac{1}{2} \cdot K\right)}\right)}^{2}} \]
      10. lift-*.f6499.8

        \[\leadsto \left(\left(-2 \cdot J\right) \cdot \cos \left(0.5 \cdot K\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \left(0.5 \cdot K\right)}\right)}^{2}} \]
    8. Applied rewrites99.8%

      \[\leadsto \left(\left(-2 \cdot J\right) \cdot \color{blue}{\cos \left(0.5 \cdot K\right)}\right) \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \left(0.5 \cdot K\right)}\right)}^{2}} \]
    9. Step-by-step derivation
      1. lift-*.f64N/A

        \[\leadsto \left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{1}{2} \cdot K\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{\color{blue}{\left(2 \cdot J\right)} \cdot \cos \left(\frac{1}{2} \cdot K\right)}\right)}^{2}} \]
      2. count-2-revN/A

        \[\leadsto \left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{1}{2} \cdot K\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{\color{blue}{\left(J + J\right)} \cdot \cos \left(\frac{1}{2} \cdot K\right)}\right)}^{2}} \]
      3. lower-+.f6499.8

        \[\leadsto \left(\left(-2 \cdot J\right) \cdot \cos \left(0.5 \cdot K\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{\color{blue}{\left(J + J\right)} \cdot \cos \left(0.5 \cdot K\right)}\right)}^{2}} \]
    10. Applied rewrites99.8%

      \[\leadsto \left(\left(-2 \cdot J\right) \cdot \cos \left(0.5 \cdot K\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{\color{blue}{\left(J + J\right)} \cdot \cos \left(0.5 \cdot K\right)}\right)}^{2}} \]

    if 4.00000000000000007e306 < (*.f64 (*.f64 (*.f64 #s(literal -2 binary64) J) (cos.f64 (/.f64 K #s(literal 2 binary64)))) (sqrt.f64 (+.f64 #s(literal 1 binary64) (pow.f64 (/.f64 U (*.f64 (*.f64 #s(literal 2 binary64) J) (cos.f64 (/.f64 K #s(literal 2 binary64))))) #s(literal 2 binary64)))))

    1. Initial program 8.7%

      \[\left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)}\right)}^{2}} \]
    2. Add Preprocessing
    3. Taylor expanded in U around -inf

      \[\leadsto \color{blue}{U} \]
    4. Step-by-step derivation
      1. Applied rewrites53.1%

        \[\leadsto \color{blue}{U} \]
    5. Recombined 3 regimes into one program.
    6. Add Preprocessing

    Alternative 2: 77.9% accurate, 0.2× speedup?

    \[\begin{array}{l} U_m = \left|U\right| \\ \begin{array}{l} t_0 := \mathsf{fma}\left(\frac{J \cdot J}{U\_m}, -2, -U\_m\right)\\ t_1 := \cos \left(\frac{K}{2}\right)\\ t_2 := \left(\left(-2 \cdot J\right) \cdot t\_1\right) \cdot \sqrt{1 + {\left(\frac{U\_m}{\left(2 \cdot J\right) \cdot t\_1}\right)}^{2}}\\ t_3 := \left(J \cdot -2\right) \cdot \cos \left(0.5 \cdot K\right)\\ \mathbf{if}\;t\_2 \leq -5 \cdot 10^{+306}:\\ \;\;\;\;t\_0\\ \mathbf{elif}\;t\_2 \leq -1 \cdot 10^{-53}:\\ \;\;\;\;t\_3\\ \mathbf{elif}\;t\_2 \leq -5 \cdot 10^{-270}:\\ \;\;\;\;t\_0\\ \mathbf{elif}\;t\_2 \leq 4 \cdot 10^{+306}:\\ \;\;\;\;t\_3\\ \mathbf{else}:\\ \;\;\;\;U\_m\\ \end{array} \end{array} \]
    U_m = (fabs.f64 U)
    (FPCore (J K U_m)
     :precision binary64
     (let* ((t_0 (fma (/ (* J J) U_m) -2.0 (- U_m)))
            (t_1 (cos (/ K 2.0)))
            (t_2
             (*
              (* (* -2.0 J) t_1)
              (sqrt (+ 1.0 (pow (/ U_m (* (* 2.0 J) t_1)) 2.0)))))
            (t_3 (* (* J -2.0) (cos (* 0.5 K)))))
       (if (<= t_2 -5e+306)
         t_0
         (if (<= t_2 -1e-53)
           t_3
           (if (<= t_2 -5e-270) t_0 (if (<= t_2 4e+306) t_3 U_m))))))
    U_m = fabs(U);
    double code(double J, double K, double U_m) {
    	double t_0 = fma(((J * J) / U_m), -2.0, -U_m);
    	double t_1 = cos((K / 2.0));
    	double t_2 = ((-2.0 * J) * t_1) * sqrt((1.0 + pow((U_m / ((2.0 * J) * t_1)), 2.0)));
    	double t_3 = (J * -2.0) * cos((0.5 * K));
    	double tmp;
    	if (t_2 <= -5e+306) {
    		tmp = t_0;
    	} else if (t_2 <= -1e-53) {
    		tmp = t_3;
    	} else if (t_2 <= -5e-270) {
    		tmp = t_0;
    	} else if (t_2 <= 4e+306) {
    		tmp = t_3;
    	} else {
    		tmp = U_m;
    	}
    	return tmp;
    }
    
    U_m = abs(U)
    function code(J, K, U_m)
    	t_0 = fma(Float64(Float64(J * J) / U_m), -2.0, Float64(-U_m))
    	t_1 = cos(Float64(K / 2.0))
    	t_2 = Float64(Float64(Float64(-2.0 * J) * t_1) * sqrt(Float64(1.0 + (Float64(U_m / Float64(Float64(2.0 * J) * t_1)) ^ 2.0))))
    	t_3 = Float64(Float64(J * -2.0) * cos(Float64(0.5 * K)))
    	tmp = 0.0
    	if (t_2 <= -5e+306)
    		tmp = t_0;
    	elseif (t_2 <= -1e-53)
    		tmp = t_3;
    	elseif (t_2 <= -5e-270)
    		tmp = t_0;
    	elseif (t_2 <= 4e+306)
    		tmp = t_3;
    	else
    		tmp = U_m;
    	end
    	return tmp
    end
    
    U_m = N[Abs[U], $MachinePrecision]
    code[J_, K_, U$95$m_] := Block[{t$95$0 = N[(N[(N[(J * J), $MachinePrecision] / U$95$m), $MachinePrecision] * -2.0 + (-U$95$m)), $MachinePrecision]}, Block[{t$95$1 = N[Cos[N[(K / 2.0), $MachinePrecision]], $MachinePrecision]}, Block[{t$95$2 = N[(N[(N[(-2.0 * J), $MachinePrecision] * t$95$1), $MachinePrecision] * N[Sqrt[N[(1.0 + N[Power[N[(U$95$m / N[(N[(2.0 * J), $MachinePrecision] * t$95$1), $MachinePrecision]), $MachinePrecision], 2.0], $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]}, Block[{t$95$3 = N[(N[(J * -2.0), $MachinePrecision] * N[Cos[N[(0.5 * K), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]}, If[LessEqual[t$95$2, -5e+306], t$95$0, If[LessEqual[t$95$2, -1e-53], t$95$3, If[LessEqual[t$95$2, -5e-270], t$95$0, If[LessEqual[t$95$2, 4e+306], t$95$3, U$95$m]]]]]]]]
    
    \begin{array}{l}
    U_m = \left|U\right|
    
    \\
    \begin{array}{l}
    t_0 := \mathsf{fma}\left(\frac{J \cdot J}{U\_m}, -2, -U\_m\right)\\
    t_1 := \cos \left(\frac{K}{2}\right)\\
    t_2 := \left(\left(-2 \cdot J\right) \cdot t\_1\right) \cdot \sqrt{1 + {\left(\frac{U\_m}{\left(2 \cdot J\right) \cdot t\_1}\right)}^{2}}\\
    t_3 := \left(J \cdot -2\right) \cdot \cos \left(0.5 \cdot K\right)\\
    \mathbf{if}\;t\_2 \leq -5 \cdot 10^{+306}:\\
    \;\;\;\;t\_0\\
    
    \mathbf{elif}\;t\_2 \leq -1 \cdot 10^{-53}:\\
    \;\;\;\;t\_3\\
    
    \mathbf{elif}\;t\_2 \leq -5 \cdot 10^{-270}:\\
    \;\;\;\;t\_0\\
    
    \mathbf{elif}\;t\_2 \leq 4 \cdot 10^{+306}:\\
    \;\;\;\;t\_3\\
    
    \mathbf{else}:\\
    \;\;\;\;U\_m\\
    
    
    \end{array}
    \end{array}
    
    Derivation
    1. Split input into 3 regimes
    2. if (*.f64 (*.f64 (*.f64 #s(literal -2 binary64) J) (cos.f64 (/.f64 K #s(literal 2 binary64)))) (sqrt.f64 (+.f64 #s(literal 1 binary64) (pow.f64 (/.f64 U (*.f64 (*.f64 #s(literal 2 binary64) J) (cos.f64 (/.f64 K #s(literal 2 binary64))))) #s(literal 2 binary64))))) < -4.99999999999999993e306 or -1.00000000000000003e-53 < (*.f64 (*.f64 (*.f64 #s(literal -2 binary64) J) (cos.f64 (/.f64 K #s(literal 2 binary64)))) (sqrt.f64 (+.f64 #s(literal 1 binary64) (pow.f64 (/.f64 U (*.f64 (*.f64 #s(literal 2 binary64) J) (cos.f64 (/.f64 K #s(literal 2 binary64))))) #s(literal 2 binary64))))) < -4.9999999999999998e-270

      1. Initial program 40.4%

        \[\left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)}\right)}^{2}} \]
      2. Add Preprocessing
      3. Taylor expanded in K around 0

        \[\leadsto \color{blue}{-2 \cdot \left(J \cdot \sqrt{1 + \frac{1}{4} \cdot \frac{{U}^{2}}{{J}^{2}}}\right)} \]
      4. Step-by-step derivation
        1. associate-*r*N/A

          \[\leadsto \left(-2 \cdot J\right) \cdot \color{blue}{\sqrt{1 + \frac{1}{4} \cdot \frac{{U}^{2}}{{J}^{2}}}} \]
        2. lower-*.f64N/A

          \[\leadsto \left(-2 \cdot J\right) \cdot \color{blue}{\sqrt{1 + \frac{1}{4} \cdot \frac{{U}^{2}}{{J}^{2}}}} \]
        3. *-commutativeN/A

          \[\leadsto \left(J \cdot -2\right) \cdot \sqrt{\color{blue}{1 + \frac{1}{4} \cdot \frac{{U}^{2}}{{J}^{2}}}} \]
        4. lower-*.f64N/A

          \[\leadsto \left(J \cdot -2\right) \cdot \sqrt{\color{blue}{1 + \frac{1}{4} \cdot \frac{{U}^{2}}{{J}^{2}}}} \]
        5. lower-sqrt.f64N/A

          \[\leadsto \left(J \cdot -2\right) \cdot \sqrt{1 + \frac{1}{4} \cdot \frac{{U}^{2}}{{J}^{2}}} \]
        6. +-commutativeN/A

          \[\leadsto \left(J \cdot -2\right) \cdot \sqrt{\frac{1}{4} \cdot \frac{{U}^{2}}{{J}^{2}} + 1} \]
        7. *-commutativeN/A

          \[\leadsto \left(J \cdot -2\right) \cdot \sqrt{\frac{{U}^{2}}{{J}^{2}} \cdot \frac{1}{4} + 1} \]
        8. lower-fma.f64N/A

          \[\leadsto \left(J \cdot -2\right) \cdot \sqrt{\mathsf{fma}\left(\frac{{U}^{2}}{{J}^{2}}, \frac{1}{4}, 1\right)} \]
        9. lower-/.f64N/A

          \[\leadsto \left(J \cdot -2\right) \cdot \sqrt{\mathsf{fma}\left(\frac{{U}^{2}}{{J}^{2}}, \frac{1}{4}, 1\right)} \]
        10. unpow2N/A

          \[\leadsto \left(J \cdot -2\right) \cdot \sqrt{\mathsf{fma}\left(\frac{U \cdot U}{{J}^{2}}, \frac{1}{4}, 1\right)} \]
        11. lower-*.f64N/A

          \[\leadsto \left(J \cdot -2\right) \cdot \sqrt{\mathsf{fma}\left(\frac{U \cdot U}{{J}^{2}}, \frac{1}{4}, 1\right)} \]
        12. unpow2N/A

          \[\leadsto \left(J \cdot -2\right) \cdot \sqrt{\mathsf{fma}\left(\frac{U \cdot U}{J \cdot J}, \frac{1}{4}, 1\right)} \]
        13. lower-*.f6416.0

          \[\leadsto \left(J \cdot -2\right) \cdot \sqrt{\mathsf{fma}\left(\frac{U \cdot U}{J \cdot J}, 0.25, 1\right)} \]
      5. Applied rewrites16.0%

        \[\leadsto \color{blue}{\left(J \cdot -2\right) \cdot \sqrt{\mathsf{fma}\left(\frac{U \cdot U}{J \cdot J}, 0.25, 1\right)}} \]
      6. Taylor expanded in J around 0

        \[\leadsto -2 \cdot \frac{{J}^{2}}{U} + \color{blue}{-1 \cdot U} \]
      7. Step-by-step derivation
        1. *-commutativeN/A

          \[\leadsto \frac{{J}^{2}}{U} \cdot -2 + -1 \cdot U \]
        2. lower-fma.f64N/A

          \[\leadsto \mathsf{fma}\left(\frac{{J}^{2}}{U}, -2, -1 \cdot U\right) \]
        3. lower-/.f64N/A

          \[\leadsto \mathsf{fma}\left(\frac{{J}^{2}}{U}, -2, -1 \cdot U\right) \]
        4. pow2N/A

          \[\leadsto \mathsf{fma}\left(\frac{J \cdot J}{U}, -2, -1 \cdot U\right) \]
        5. lift-*.f64N/A

          \[\leadsto \mathsf{fma}\left(\frac{J \cdot J}{U}, -2, -1 \cdot U\right) \]
        6. mul-1-negN/A

          \[\leadsto \mathsf{fma}\left(\frac{J \cdot J}{U}, -2, \mathsf{neg}\left(U\right)\right) \]
        7. lift-neg.f6447.4

          \[\leadsto \mathsf{fma}\left(\frac{J \cdot J}{U}, -2, -U\right) \]
      8. Applied rewrites47.4%

        \[\leadsto \mathsf{fma}\left(\frac{J \cdot J}{U}, \color{blue}{-2}, -U\right) \]

      if -4.99999999999999993e306 < (*.f64 (*.f64 (*.f64 #s(literal -2 binary64) J) (cos.f64 (/.f64 K #s(literal 2 binary64)))) (sqrt.f64 (+.f64 #s(literal 1 binary64) (pow.f64 (/.f64 U (*.f64 (*.f64 #s(literal 2 binary64) J) (cos.f64 (/.f64 K #s(literal 2 binary64))))) #s(literal 2 binary64))))) < -1.00000000000000003e-53 or -4.9999999999999998e-270 < (*.f64 (*.f64 (*.f64 #s(literal -2 binary64) J) (cos.f64 (/.f64 K #s(literal 2 binary64)))) (sqrt.f64 (+.f64 #s(literal 1 binary64) (pow.f64 (/.f64 U (*.f64 (*.f64 #s(literal 2 binary64) J) (cos.f64 (/.f64 K #s(literal 2 binary64))))) #s(literal 2 binary64))))) < 4.00000000000000007e306

      1. Initial program 99.8%

        \[\left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)}\right)}^{2}} \]
      2. Add Preprocessing
      3. Taylor expanded in J around inf

        \[\leadsto \color{blue}{-2 \cdot \left(J \cdot \cos \left(\frac{1}{2} \cdot K\right)\right)} \]
      4. Step-by-step derivation
        1. associate-*r*N/A

          \[\leadsto \left(-2 \cdot J\right) \cdot \color{blue}{\cos \left(\frac{1}{2} \cdot K\right)} \]
        2. lower-*.f64N/A

          \[\leadsto \left(-2 \cdot J\right) \cdot \color{blue}{\cos \left(\frac{1}{2} \cdot K\right)} \]
        3. *-commutativeN/A

          \[\leadsto \left(J \cdot -2\right) \cdot \cos \color{blue}{\left(\frac{1}{2} \cdot K\right)} \]
        4. lower-*.f64N/A

          \[\leadsto \left(J \cdot -2\right) \cdot \cos \color{blue}{\left(\frac{1}{2} \cdot K\right)} \]
        5. lower-cos.f64N/A

          \[\leadsto \left(J \cdot -2\right) \cdot \cos \left(\frac{1}{2} \cdot K\right) \]
        6. lower-*.f6474.7

          \[\leadsto \left(J \cdot -2\right) \cdot \cos \left(0.5 \cdot K\right) \]
      5. Applied rewrites74.7%

        \[\leadsto \color{blue}{\left(J \cdot -2\right) \cdot \cos \left(0.5 \cdot K\right)} \]

      if 4.00000000000000007e306 < (*.f64 (*.f64 (*.f64 #s(literal -2 binary64) J) (cos.f64 (/.f64 K #s(literal 2 binary64)))) (sqrt.f64 (+.f64 #s(literal 1 binary64) (pow.f64 (/.f64 U (*.f64 (*.f64 #s(literal 2 binary64) J) (cos.f64 (/.f64 K #s(literal 2 binary64))))) #s(literal 2 binary64)))))

      1. Initial program 8.7%

        \[\left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)}\right)}^{2}} \]
      2. Add Preprocessing
      3. Taylor expanded in U around -inf

        \[\leadsto \color{blue}{U} \]
      4. Step-by-step derivation
        1. Applied rewrites53.1%

          \[\leadsto \color{blue}{U} \]
      5. Recombined 3 regimes into one program.
      6. Add Preprocessing

      Alternative 3: 56.7% accurate, 0.3× speedup?

      \[\begin{array}{l} U_m = \left|U\right| \\ \begin{array}{l} t_0 := \mathsf{fma}\left(\frac{J \cdot J}{U\_m}, -2, -U\_m\right)\\ t_1 := \cos \left(\frac{K}{2}\right)\\ t_2 := \left(\left(-2 \cdot J\right) \cdot t\_1\right) \cdot \sqrt{1 + {\left(\frac{U\_m}{\left(2 \cdot J\right) \cdot t\_1}\right)}^{2}}\\ \mathbf{if}\;t\_2 \leq -2 \cdot 10^{+305}:\\ \;\;\;\;t\_0\\ \mathbf{elif}\;t\_2 \leq -1 \cdot 10^{-53}:\\ \;\;\;\;\left(J \cdot -2\right) \cdot \sqrt{\mathsf{fma}\left(\frac{U\_m \cdot U\_m}{J \cdot J}, 0.25, 1\right)}\\ \mathbf{elif}\;t\_2 \leq -5 \cdot 10^{-270}:\\ \;\;\;\;t\_0\\ \mathbf{else}:\\ \;\;\;\;U\_m\\ \end{array} \end{array} \]
      U_m = (fabs.f64 U)
      (FPCore (J K U_m)
       :precision binary64
       (let* ((t_0 (fma (/ (* J J) U_m) -2.0 (- U_m)))
              (t_1 (cos (/ K 2.0)))
              (t_2
               (*
                (* (* -2.0 J) t_1)
                (sqrt (+ 1.0 (pow (/ U_m (* (* 2.0 J) t_1)) 2.0))))))
         (if (<= t_2 -2e+305)
           t_0
           (if (<= t_2 -1e-53)
             (* (* J -2.0) (sqrt (fma (/ (* U_m U_m) (* J J)) 0.25 1.0)))
             (if (<= t_2 -5e-270) t_0 U_m)))))
      U_m = fabs(U);
      double code(double J, double K, double U_m) {
      	double t_0 = fma(((J * J) / U_m), -2.0, -U_m);
      	double t_1 = cos((K / 2.0));
      	double t_2 = ((-2.0 * J) * t_1) * sqrt((1.0 + pow((U_m / ((2.0 * J) * t_1)), 2.0)));
      	double tmp;
      	if (t_2 <= -2e+305) {
      		tmp = t_0;
      	} else if (t_2 <= -1e-53) {
      		tmp = (J * -2.0) * sqrt(fma(((U_m * U_m) / (J * J)), 0.25, 1.0));
      	} else if (t_2 <= -5e-270) {
      		tmp = t_0;
      	} else {
      		tmp = U_m;
      	}
      	return tmp;
      }
      
      U_m = abs(U)
      function code(J, K, U_m)
      	t_0 = fma(Float64(Float64(J * J) / U_m), -2.0, Float64(-U_m))
      	t_1 = cos(Float64(K / 2.0))
      	t_2 = Float64(Float64(Float64(-2.0 * J) * t_1) * sqrt(Float64(1.0 + (Float64(U_m / Float64(Float64(2.0 * J) * t_1)) ^ 2.0))))
      	tmp = 0.0
      	if (t_2 <= -2e+305)
      		tmp = t_0;
      	elseif (t_2 <= -1e-53)
      		tmp = Float64(Float64(J * -2.0) * sqrt(fma(Float64(Float64(U_m * U_m) / Float64(J * J)), 0.25, 1.0)));
      	elseif (t_2 <= -5e-270)
      		tmp = t_0;
      	else
      		tmp = U_m;
      	end
      	return tmp
      end
      
      U_m = N[Abs[U], $MachinePrecision]
      code[J_, K_, U$95$m_] := Block[{t$95$0 = N[(N[(N[(J * J), $MachinePrecision] / U$95$m), $MachinePrecision] * -2.0 + (-U$95$m)), $MachinePrecision]}, Block[{t$95$1 = N[Cos[N[(K / 2.0), $MachinePrecision]], $MachinePrecision]}, Block[{t$95$2 = N[(N[(N[(-2.0 * J), $MachinePrecision] * t$95$1), $MachinePrecision] * N[Sqrt[N[(1.0 + N[Power[N[(U$95$m / N[(N[(2.0 * J), $MachinePrecision] * t$95$1), $MachinePrecision]), $MachinePrecision], 2.0], $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]}, If[LessEqual[t$95$2, -2e+305], t$95$0, If[LessEqual[t$95$2, -1e-53], N[(N[(J * -2.0), $MachinePrecision] * N[Sqrt[N[(N[(N[(U$95$m * U$95$m), $MachinePrecision] / N[(J * J), $MachinePrecision]), $MachinePrecision] * 0.25 + 1.0), $MachinePrecision]], $MachinePrecision]), $MachinePrecision], If[LessEqual[t$95$2, -5e-270], t$95$0, U$95$m]]]]]]
      
      \begin{array}{l}
      U_m = \left|U\right|
      
      \\
      \begin{array}{l}
      t_0 := \mathsf{fma}\left(\frac{J \cdot J}{U\_m}, -2, -U\_m\right)\\
      t_1 := \cos \left(\frac{K}{2}\right)\\
      t_2 := \left(\left(-2 \cdot J\right) \cdot t\_1\right) \cdot \sqrt{1 + {\left(\frac{U\_m}{\left(2 \cdot J\right) \cdot t\_1}\right)}^{2}}\\
      \mathbf{if}\;t\_2 \leq -2 \cdot 10^{+305}:\\
      \;\;\;\;t\_0\\
      
      \mathbf{elif}\;t\_2 \leq -1 \cdot 10^{-53}:\\
      \;\;\;\;\left(J \cdot -2\right) \cdot \sqrt{\mathsf{fma}\left(\frac{U\_m \cdot U\_m}{J \cdot J}, 0.25, 1\right)}\\
      
      \mathbf{elif}\;t\_2 \leq -5 \cdot 10^{-270}:\\
      \;\;\;\;t\_0\\
      
      \mathbf{else}:\\
      \;\;\;\;U\_m\\
      
      
      \end{array}
      \end{array}
      
      Derivation
      1. Split input into 3 regimes
      2. if (*.f64 (*.f64 (*.f64 #s(literal -2 binary64) J) (cos.f64 (/.f64 K #s(literal 2 binary64)))) (sqrt.f64 (+.f64 #s(literal 1 binary64) (pow.f64 (/.f64 U (*.f64 (*.f64 #s(literal 2 binary64) J) (cos.f64 (/.f64 K #s(literal 2 binary64))))) #s(literal 2 binary64))))) < -1.9999999999999999e305 or -1.00000000000000003e-53 < (*.f64 (*.f64 (*.f64 #s(literal -2 binary64) J) (cos.f64 (/.f64 K #s(literal 2 binary64)))) (sqrt.f64 (+.f64 #s(literal 1 binary64) (pow.f64 (/.f64 U (*.f64 (*.f64 #s(literal 2 binary64) J) (cos.f64 (/.f64 K #s(literal 2 binary64))))) #s(literal 2 binary64))))) < -4.9999999999999998e-270

        1. Initial program 41.3%

          \[\left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)}\right)}^{2}} \]
        2. Add Preprocessing
        3. Taylor expanded in K around 0

          \[\leadsto \color{blue}{-2 \cdot \left(J \cdot \sqrt{1 + \frac{1}{4} \cdot \frac{{U}^{2}}{{J}^{2}}}\right)} \]
        4. Step-by-step derivation
          1. associate-*r*N/A

            \[\leadsto \left(-2 \cdot J\right) \cdot \color{blue}{\sqrt{1 + \frac{1}{4} \cdot \frac{{U}^{2}}{{J}^{2}}}} \]
          2. lower-*.f64N/A

            \[\leadsto \left(-2 \cdot J\right) \cdot \color{blue}{\sqrt{1 + \frac{1}{4} \cdot \frac{{U}^{2}}{{J}^{2}}}} \]
          3. *-commutativeN/A

            \[\leadsto \left(J \cdot -2\right) \cdot \sqrt{\color{blue}{1 + \frac{1}{4} \cdot \frac{{U}^{2}}{{J}^{2}}}} \]
          4. lower-*.f64N/A

            \[\leadsto \left(J \cdot -2\right) \cdot \sqrt{\color{blue}{1 + \frac{1}{4} \cdot \frac{{U}^{2}}{{J}^{2}}}} \]
          5. lower-sqrt.f64N/A

            \[\leadsto \left(J \cdot -2\right) \cdot \sqrt{1 + \frac{1}{4} \cdot \frac{{U}^{2}}{{J}^{2}}} \]
          6. +-commutativeN/A

            \[\leadsto \left(J \cdot -2\right) \cdot \sqrt{\frac{1}{4} \cdot \frac{{U}^{2}}{{J}^{2}} + 1} \]
          7. *-commutativeN/A

            \[\leadsto \left(J \cdot -2\right) \cdot \sqrt{\frac{{U}^{2}}{{J}^{2}} \cdot \frac{1}{4} + 1} \]
          8. lower-fma.f64N/A

            \[\leadsto \left(J \cdot -2\right) \cdot \sqrt{\mathsf{fma}\left(\frac{{U}^{2}}{{J}^{2}}, \frac{1}{4}, 1\right)} \]
          9. lower-/.f64N/A

            \[\leadsto \left(J \cdot -2\right) \cdot \sqrt{\mathsf{fma}\left(\frac{{U}^{2}}{{J}^{2}}, \frac{1}{4}, 1\right)} \]
          10. unpow2N/A

            \[\leadsto \left(J \cdot -2\right) \cdot \sqrt{\mathsf{fma}\left(\frac{U \cdot U}{{J}^{2}}, \frac{1}{4}, 1\right)} \]
          11. lower-*.f64N/A

            \[\leadsto \left(J \cdot -2\right) \cdot \sqrt{\mathsf{fma}\left(\frac{U \cdot U}{{J}^{2}}, \frac{1}{4}, 1\right)} \]
          12. unpow2N/A

            \[\leadsto \left(J \cdot -2\right) \cdot \sqrt{\mathsf{fma}\left(\frac{U \cdot U}{J \cdot J}, \frac{1}{4}, 1\right)} \]
          13. lower-*.f6415.7

            \[\leadsto \left(J \cdot -2\right) \cdot \sqrt{\mathsf{fma}\left(\frac{U \cdot U}{J \cdot J}, 0.25, 1\right)} \]
        5. Applied rewrites15.7%

          \[\leadsto \color{blue}{\left(J \cdot -2\right) \cdot \sqrt{\mathsf{fma}\left(\frac{U \cdot U}{J \cdot J}, 0.25, 1\right)}} \]
        6. Taylor expanded in J around 0

          \[\leadsto -2 \cdot \frac{{J}^{2}}{U} + \color{blue}{-1 \cdot U} \]
        7. Step-by-step derivation
          1. *-commutativeN/A

            \[\leadsto \frac{{J}^{2}}{U} \cdot -2 + -1 \cdot U \]
          2. lower-fma.f64N/A

            \[\leadsto \mathsf{fma}\left(\frac{{J}^{2}}{U}, -2, -1 \cdot U\right) \]
          3. lower-/.f64N/A

            \[\leadsto \mathsf{fma}\left(\frac{{J}^{2}}{U}, -2, -1 \cdot U\right) \]
          4. pow2N/A

            \[\leadsto \mathsf{fma}\left(\frac{J \cdot J}{U}, -2, -1 \cdot U\right) \]
          5. lift-*.f64N/A

            \[\leadsto \mathsf{fma}\left(\frac{J \cdot J}{U}, -2, -1 \cdot U\right) \]
          6. mul-1-negN/A

            \[\leadsto \mathsf{fma}\left(\frac{J \cdot J}{U}, -2, \mathsf{neg}\left(U\right)\right) \]
          7. lift-neg.f6446.8

            \[\leadsto \mathsf{fma}\left(\frac{J \cdot J}{U}, -2, -U\right) \]
        8. Applied rewrites46.8%

          \[\leadsto \mathsf{fma}\left(\frac{J \cdot J}{U}, \color{blue}{-2}, -U\right) \]

        if -1.9999999999999999e305 < (*.f64 (*.f64 (*.f64 #s(literal -2 binary64) J) (cos.f64 (/.f64 K #s(literal 2 binary64)))) (sqrt.f64 (+.f64 #s(literal 1 binary64) (pow.f64 (/.f64 U (*.f64 (*.f64 #s(literal 2 binary64) J) (cos.f64 (/.f64 K #s(literal 2 binary64))))) #s(literal 2 binary64))))) < -1.00000000000000003e-53

        1. Initial program 99.8%

          \[\left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)}\right)}^{2}} \]
        2. Add Preprocessing
        3. Taylor expanded in K around 0

          \[\leadsto \color{blue}{-2 \cdot \left(J \cdot \sqrt{1 + \frac{1}{4} \cdot \frac{{U}^{2}}{{J}^{2}}}\right)} \]
        4. Step-by-step derivation
          1. associate-*r*N/A

            \[\leadsto \left(-2 \cdot J\right) \cdot \color{blue}{\sqrt{1 + \frac{1}{4} \cdot \frac{{U}^{2}}{{J}^{2}}}} \]
          2. lower-*.f64N/A

            \[\leadsto \left(-2 \cdot J\right) \cdot \color{blue}{\sqrt{1 + \frac{1}{4} \cdot \frac{{U}^{2}}{{J}^{2}}}} \]
          3. *-commutativeN/A

            \[\leadsto \left(J \cdot -2\right) \cdot \sqrt{\color{blue}{1 + \frac{1}{4} \cdot \frac{{U}^{2}}{{J}^{2}}}} \]
          4. lower-*.f64N/A

            \[\leadsto \left(J \cdot -2\right) \cdot \sqrt{\color{blue}{1 + \frac{1}{4} \cdot \frac{{U}^{2}}{{J}^{2}}}} \]
          5. lower-sqrt.f64N/A

            \[\leadsto \left(J \cdot -2\right) \cdot \sqrt{1 + \frac{1}{4} \cdot \frac{{U}^{2}}{{J}^{2}}} \]
          6. +-commutativeN/A

            \[\leadsto \left(J \cdot -2\right) \cdot \sqrt{\frac{1}{4} \cdot \frac{{U}^{2}}{{J}^{2}} + 1} \]
          7. *-commutativeN/A

            \[\leadsto \left(J \cdot -2\right) \cdot \sqrt{\frac{{U}^{2}}{{J}^{2}} \cdot \frac{1}{4} + 1} \]
          8. lower-fma.f64N/A

            \[\leadsto \left(J \cdot -2\right) \cdot \sqrt{\mathsf{fma}\left(\frac{{U}^{2}}{{J}^{2}}, \frac{1}{4}, 1\right)} \]
          9. lower-/.f64N/A

            \[\leadsto \left(J \cdot -2\right) \cdot \sqrt{\mathsf{fma}\left(\frac{{U}^{2}}{{J}^{2}}, \frac{1}{4}, 1\right)} \]
          10. unpow2N/A

            \[\leadsto \left(J \cdot -2\right) \cdot \sqrt{\mathsf{fma}\left(\frac{U \cdot U}{{J}^{2}}, \frac{1}{4}, 1\right)} \]
          11. lower-*.f64N/A

            \[\leadsto \left(J \cdot -2\right) \cdot \sqrt{\mathsf{fma}\left(\frac{U \cdot U}{{J}^{2}}, \frac{1}{4}, 1\right)} \]
          12. unpow2N/A

            \[\leadsto \left(J \cdot -2\right) \cdot \sqrt{\mathsf{fma}\left(\frac{U \cdot U}{J \cdot J}, \frac{1}{4}, 1\right)} \]
          13. lower-*.f6453.6

            \[\leadsto \left(J \cdot -2\right) \cdot \sqrt{\mathsf{fma}\left(\frac{U \cdot U}{J \cdot J}, 0.25, 1\right)} \]
        5. Applied rewrites53.6%

          \[\leadsto \color{blue}{\left(J \cdot -2\right) \cdot \sqrt{\mathsf{fma}\left(\frac{U \cdot U}{J \cdot J}, 0.25, 1\right)}} \]

        if -4.9999999999999998e-270 < (*.f64 (*.f64 (*.f64 #s(literal -2 binary64) J) (cos.f64 (/.f64 K #s(literal 2 binary64)))) (sqrt.f64 (+.f64 #s(literal 1 binary64) (pow.f64 (/.f64 U (*.f64 (*.f64 #s(literal 2 binary64) J) (cos.f64 (/.f64 K #s(literal 2 binary64))))) #s(literal 2 binary64)))))

        1. Initial program 72.7%

          \[\left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)}\right)}^{2}} \]
        2. Add Preprocessing
        3. Taylor expanded in U around -inf

          \[\leadsto \color{blue}{U} \]
        4. Step-by-step derivation
          1. Applied rewrites26.7%

            \[\leadsto \color{blue}{U} \]
        5. Recombined 3 regimes into one program.
        6. Add Preprocessing

        Alternative 4: 54.6% accurate, 0.3× speedup?

        \[\begin{array}{l} U_m = \left|U\right| \\ \begin{array}{l} t_0 := \mathsf{fma}\left(\frac{J \cdot J}{U\_m}, -2, -U\_m\right)\\ t_1 := \cos \left(\frac{K}{2}\right)\\ t_2 := \left(\left(-2 \cdot J\right) \cdot t\_1\right) \cdot \sqrt{1 + {\left(\frac{U\_m}{\left(2 \cdot J\right) \cdot t\_1}\right)}^{2}}\\ \mathbf{if}\;t\_2 \leq -5 \cdot 10^{+306}:\\ \;\;\;\;t\_0\\ \mathbf{elif}\;t\_2 \leq -1 \cdot 10^{-53}:\\ \;\;\;\;J \cdot -2\\ \mathbf{elif}\;t\_2 \leq -5 \cdot 10^{-270}:\\ \;\;\;\;t\_0\\ \mathbf{else}:\\ \;\;\;\;U\_m\\ \end{array} \end{array} \]
        U_m = (fabs.f64 U)
        (FPCore (J K U_m)
         :precision binary64
         (let* ((t_0 (fma (/ (* J J) U_m) -2.0 (- U_m)))
                (t_1 (cos (/ K 2.0)))
                (t_2
                 (*
                  (* (* -2.0 J) t_1)
                  (sqrt (+ 1.0 (pow (/ U_m (* (* 2.0 J) t_1)) 2.0))))))
           (if (<= t_2 -5e+306)
             t_0
             (if (<= t_2 -1e-53) (* J -2.0) (if (<= t_2 -5e-270) t_0 U_m)))))
        U_m = fabs(U);
        double code(double J, double K, double U_m) {
        	double t_0 = fma(((J * J) / U_m), -2.0, -U_m);
        	double t_1 = cos((K / 2.0));
        	double t_2 = ((-2.0 * J) * t_1) * sqrt((1.0 + pow((U_m / ((2.0 * J) * t_1)), 2.0)));
        	double tmp;
        	if (t_2 <= -5e+306) {
        		tmp = t_0;
        	} else if (t_2 <= -1e-53) {
        		tmp = J * -2.0;
        	} else if (t_2 <= -5e-270) {
        		tmp = t_0;
        	} else {
        		tmp = U_m;
        	}
        	return tmp;
        }
        
        U_m = abs(U)
        function code(J, K, U_m)
        	t_0 = fma(Float64(Float64(J * J) / U_m), -2.0, Float64(-U_m))
        	t_1 = cos(Float64(K / 2.0))
        	t_2 = Float64(Float64(Float64(-2.0 * J) * t_1) * sqrt(Float64(1.0 + (Float64(U_m / Float64(Float64(2.0 * J) * t_1)) ^ 2.0))))
        	tmp = 0.0
        	if (t_2 <= -5e+306)
        		tmp = t_0;
        	elseif (t_2 <= -1e-53)
        		tmp = Float64(J * -2.0);
        	elseif (t_2 <= -5e-270)
        		tmp = t_0;
        	else
        		tmp = U_m;
        	end
        	return tmp
        end
        
        U_m = N[Abs[U], $MachinePrecision]
        code[J_, K_, U$95$m_] := Block[{t$95$0 = N[(N[(N[(J * J), $MachinePrecision] / U$95$m), $MachinePrecision] * -2.0 + (-U$95$m)), $MachinePrecision]}, Block[{t$95$1 = N[Cos[N[(K / 2.0), $MachinePrecision]], $MachinePrecision]}, Block[{t$95$2 = N[(N[(N[(-2.0 * J), $MachinePrecision] * t$95$1), $MachinePrecision] * N[Sqrt[N[(1.0 + N[Power[N[(U$95$m / N[(N[(2.0 * J), $MachinePrecision] * t$95$1), $MachinePrecision]), $MachinePrecision], 2.0], $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]}, If[LessEqual[t$95$2, -5e+306], t$95$0, If[LessEqual[t$95$2, -1e-53], N[(J * -2.0), $MachinePrecision], If[LessEqual[t$95$2, -5e-270], t$95$0, U$95$m]]]]]]
        
        \begin{array}{l}
        U_m = \left|U\right|
        
        \\
        \begin{array}{l}
        t_0 := \mathsf{fma}\left(\frac{J \cdot J}{U\_m}, -2, -U\_m\right)\\
        t_1 := \cos \left(\frac{K}{2}\right)\\
        t_2 := \left(\left(-2 \cdot J\right) \cdot t\_1\right) \cdot \sqrt{1 + {\left(\frac{U\_m}{\left(2 \cdot J\right) \cdot t\_1}\right)}^{2}}\\
        \mathbf{if}\;t\_2 \leq -5 \cdot 10^{+306}:\\
        \;\;\;\;t\_0\\
        
        \mathbf{elif}\;t\_2 \leq -1 \cdot 10^{-53}:\\
        \;\;\;\;J \cdot -2\\
        
        \mathbf{elif}\;t\_2 \leq -5 \cdot 10^{-270}:\\
        \;\;\;\;t\_0\\
        
        \mathbf{else}:\\
        \;\;\;\;U\_m\\
        
        
        \end{array}
        \end{array}
        
        Derivation
        1. Split input into 3 regimes
        2. if (*.f64 (*.f64 (*.f64 #s(literal -2 binary64) J) (cos.f64 (/.f64 K #s(literal 2 binary64)))) (sqrt.f64 (+.f64 #s(literal 1 binary64) (pow.f64 (/.f64 U (*.f64 (*.f64 #s(literal 2 binary64) J) (cos.f64 (/.f64 K #s(literal 2 binary64))))) #s(literal 2 binary64))))) < -4.99999999999999993e306 or -1.00000000000000003e-53 < (*.f64 (*.f64 (*.f64 #s(literal -2 binary64) J) (cos.f64 (/.f64 K #s(literal 2 binary64)))) (sqrt.f64 (+.f64 #s(literal 1 binary64) (pow.f64 (/.f64 U (*.f64 (*.f64 #s(literal 2 binary64) J) (cos.f64 (/.f64 K #s(literal 2 binary64))))) #s(literal 2 binary64))))) < -4.9999999999999998e-270

          1. Initial program 40.4%

            \[\left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)}\right)}^{2}} \]
          2. Add Preprocessing
          3. Taylor expanded in K around 0

            \[\leadsto \color{blue}{-2 \cdot \left(J \cdot \sqrt{1 + \frac{1}{4} \cdot \frac{{U}^{2}}{{J}^{2}}}\right)} \]
          4. Step-by-step derivation
            1. associate-*r*N/A

              \[\leadsto \left(-2 \cdot J\right) \cdot \color{blue}{\sqrt{1 + \frac{1}{4} \cdot \frac{{U}^{2}}{{J}^{2}}}} \]
            2. lower-*.f64N/A

              \[\leadsto \left(-2 \cdot J\right) \cdot \color{blue}{\sqrt{1 + \frac{1}{4} \cdot \frac{{U}^{2}}{{J}^{2}}}} \]
            3. *-commutativeN/A

              \[\leadsto \left(J \cdot -2\right) \cdot \sqrt{\color{blue}{1 + \frac{1}{4} \cdot \frac{{U}^{2}}{{J}^{2}}}} \]
            4. lower-*.f64N/A

              \[\leadsto \left(J \cdot -2\right) \cdot \sqrt{\color{blue}{1 + \frac{1}{4} \cdot \frac{{U}^{2}}{{J}^{2}}}} \]
            5. lower-sqrt.f64N/A

              \[\leadsto \left(J \cdot -2\right) \cdot \sqrt{1 + \frac{1}{4} \cdot \frac{{U}^{2}}{{J}^{2}}} \]
            6. +-commutativeN/A

              \[\leadsto \left(J \cdot -2\right) \cdot \sqrt{\frac{1}{4} \cdot \frac{{U}^{2}}{{J}^{2}} + 1} \]
            7. *-commutativeN/A

              \[\leadsto \left(J \cdot -2\right) \cdot \sqrt{\frac{{U}^{2}}{{J}^{2}} \cdot \frac{1}{4} + 1} \]
            8. lower-fma.f64N/A

              \[\leadsto \left(J \cdot -2\right) \cdot \sqrt{\mathsf{fma}\left(\frac{{U}^{2}}{{J}^{2}}, \frac{1}{4}, 1\right)} \]
            9. lower-/.f64N/A

              \[\leadsto \left(J \cdot -2\right) \cdot \sqrt{\mathsf{fma}\left(\frac{{U}^{2}}{{J}^{2}}, \frac{1}{4}, 1\right)} \]
            10. unpow2N/A

              \[\leadsto \left(J \cdot -2\right) \cdot \sqrt{\mathsf{fma}\left(\frac{U \cdot U}{{J}^{2}}, \frac{1}{4}, 1\right)} \]
            11. lower-*.f64N/A

              \[\leadsto \left(J \cdot -2\right) \cdot \sqrt{\mathsf{fma}\left(\frac{U \cdot U}{{J}^{2}}, \frac{1}{4}, 1\right)} \]
            12. unpow2N/A

              \[\leadsto \left(J \cdot -2\right) \cdot \sqrt{\mathsf{fma}\left(\frac{U \cdot U}{J \cdot J}, \frac{1}{4}, 1\right)} \]
            13. lower-*.f6416.0

              \[\leadsto \left(J \cdot -2\right) \cdot \sqrt{\mathsf{fma}\left(\frac{U \cdot U}{J \cdot J}, 0.25, 1\right)} \]
          5. Applied rewrites16.0%

            \[\leadsto \color{blue}{\left(J \cdot -2\right) \cdot \sqrt{\mathsf{fma}\left(\frac{U \cdot U}{J \cdot J}, 0.25, 1\right)}} \]
          6. Taylor expanded in J around 0

            \[\leadsto -2 \cdot \frac{{J}^{2}}{U} + \color{blue}{-1 \cdot U} \]
          7. Step-by-step derivation
            1. *-commutativeN/A

              \[\leadsto \frac{{J}^{2}}{U} \cdot -2 + -1 \cdot U \]
            2. lower-fma.f64N/A

              \[\leadsto \mathsf{fma}\left(\frac{{J}^{2}}{U}, -2, -1 \cdot U\right) \]
            3. lower-/.f64N/A

              \[\leadsto \mathsf{fma}\left(\frac{{J}^{2}}{U}, -2, -1 \cdot U\right) \]
            4. pow2N/A

              \[\leadsto \mathsf{fma}\left(\frac{J \cdot J}{U}, -2, -1 \cdot U\right) \]
            5. lift-*.f64N/A

              \[\leadsto \mathsf{fma}\left(\frac{J \cdot J}{U}, -2, -1 \cdot U\right) \]
            6. mul-1-negN/A

              \[\leadsto \mathsf{fma}\left(\frac{J \cdot J}{U}, -2, \mathsf{neg}\left(U\right)\right) \]
            7. lift-neg.f6447.4

              \[\leadsto \mathsf{fma}\left(\frac{J \cdot J}{U}, -2, -U\right) \]
          8. Applied rewrites47.4%

            \[\leadsto \mathsf{fma}\left(\frac{J \cdot J}{U}, \color{blue}{-2}, -U\right) \]

          if -4.99999999999999993e306 < (*.f64 (*.f64 (*.f64 #s(literal -2 binary64) J) (cos.f64 (/.f64 K #s(literal 2 binary64)))) (sqrt.f64 (+.f64 #s(literal 1 binary64) (pow.f64 (/.f64 U (*.f64 (*.f64 #s(literal 2 binary64) J) (cos.f64 (/.f64 K #s(literal 2 binary64))))) #s(literal 2 binary64))))) < -1.00000000000000003e-53

          1. Initial program 99.8%

            \[\left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)}\right)}^{2}} \]
          2. Add Preprocessing
          3. Taylor expanded in K around 0

            \[\leadsto \color{blue}{-2 \cdot \left(J \cdot \sqrt{1 + \frac{1}{4} \cdot \frac{{U}^{2}}{{J}^{2}}}\right)} \]
          4. Step-by-step derivation
            1. associate-*r*N/A

              \[\leadsto \left(-2 \cdot J\right) \cdot \color{blue}{\sqrt{1 + \frac{1}{4} \cdot \frac{{U}^{2}}{{J}^{2}}}} \]
            2. lower-*.f64N/A

              \[\leadsto \left(-2 \cdot J\right) \cdot \color{blue}{\sqrt{1 + \frac{1}{4} \cdot \frac{{U}^{2}}{{J}^{2}}}} \]
            3. *-commutativeN/A

              \[\leadsto \left(J \cdot -2\right) \cdot \sqrt{\color{blue}{1 + \frac{1}{4} \cdot \frac{{U}^{2}}{{J}^{2}}}} \]
            4. lower-*.f64N/A

              \[\leadsto \left(J \cdot -2\right) \cdot \sqrt{\color{blue}{1 + \frac{1}{4} \cdot \frac{{U}^{2}}{{J}^{2}}}} \]
            5. lower-sqrt.f64N/A

              \[\leadsto \left(J \cdot -2\right) \cdot \sqrt{1 + \frac{1}{4} \cdot \frac{{U}^{2}}{{J}^{2}}} \]
            6. +-commutativeN/A

              \[\leadsto \left(J \cdot -2\right) \cdot \sqrt{\frac{1}{4} \cdot \frac{{U}^{2}}{{J}^{2}} + 1} \]
            7. *-commutativeN/A

              \[\leadsto \left(J \cdot -2\right) \cdot \sqrt{\frac{{U}^{2}}{{J}^{2}} \cdot \frac{1}{4} + 1} \]
            8. lower-fma.f64N/A

              \[\leadsto \left(J \cdot -2\right) \cdot \sqrt{\mathsf{fma}\left(\frac{{U}^{2}}{{J}^{2}}, \frac{1}{4}, 1\right)} \]
            9. lower-/.f64N/A

              \[\leadsto \left(J \cdot -2\right) \cdot \sqrt{\mathsf{fma}\left(\frac{{U}^{2}}{{J}^{2}}, \frac{1}{4}, 1\right)} \]
            10. unpow2N/A

              \[\leadsto \left(J \cdot -2\right) \cdot \sqrt{\mathsf{fma}\left(\frac{U \cdot U}{{J}^{2}}, \frac{1}{4}, 1\right)} \]
            11. lower-*.f64N/A

              \[\leadsto \left(J \cdot -2\right) \cdot \sqrt{\mathsf{fma}\left(\frac{U \cdot U}{{J}^{2}}, \frac{1}{4}, 1\right)} \]
            12. unpow2N/A

              \[\leadsto \left(J \cdot -2\right) \cdot \sqrt{\mathsf{fma}\left(\frac{U \cdot U}{J \cdot J}, \frac{1}{4}, 1\right)} \]
            13. lower-*.f6452.7

              \[\leadsto \left(J \cdot -2\right) \cdot \sqrt{\mathsf{fma}\left(\frac{U \cdot U}{J \cdot J}, 0.25, 1\right)} \]
          5. Applied rewrites52.7%

            \[\leadsto \color{blue}{\left(J \cdot -2\right) \cdot \sqrt{\mathsf{fma}\left(\frac{U \cdot U}{J \cdot J}, 0.25, 1\right)}} \]
          6. Taylor expanded in J around inf

            \[\leadsto -2 \cdot \color{blue}{J} \]
          7. Step-by-step derivation
            1. *-commutativeN/A

              \[\leadsto J \cdot -2 \]
            2. lift-*.f6449.8

              \[\leadsto J \cdot -2 \]
          8. Applied rewrites49.8%

            \[\leadsto J \cdot \color{blue}{-2} \]

          if -4.9999999999999998e-270 < (*.f64 (*.f64 (*.f64 #s(literal -2 binary64) J) (cos.f64 (/.f64 K #s(literal 2 binary64)))) (sqrt.f64 (+.f64 #s(literal 1 binary64) (pow.f64 (/.f64 U (*.f64 (*.f64 #s(literal 2 binary64) J) (cos.f64 (/.f64 K #s(literal 2 binary64))))) #s(literal 2 binary64)))))

          1. Initial program 72.7%

            \[\left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)}\right)}^{2}} \]
          2. Add Preprocessing
          3. Taylor expanded in U around -inf

            \[\leadsto \color{blue}{U} \]
          4. Step-by-step derivation
            1. Applied rewrites26.7%

              \[\leadsto \color{blue}{U} \]
          5. Recombined 3 regimes into one program.
          6. Add Preprocessing

          Alternative 5: 54.6% accurate, 0.3× speedup?

          \[\begin{array}{l} U_m = \left|U\right| \\ \begin{array}{l} t_0 := \cos \left(\frac{K}{2}\right)\\ t_1 := \left(\left(-2 \cdot J\right) \cdot t\_0\right) \cdot \sqrt{1 + {\left(\frac{U\_m}{\left(2 \cdot J\right) \cdot t\_0}\right)}^{2}}\\ \mathbf{if}\;t\_1 \leq -5 \cdot 10^{+306}:\\ \;\;\;\;-U\_m\\ \mathbf{elif}\;t\_1 \leq -1 \cdot 10^{-53}:\\ \;\;\;\;J \cdot -2\\ \mathbf{elif}\;t\_1 \leq -5 \cdot 10^{-270}:\\ \;\;\;\;-U\_m\\ \mathbf{else}:\\ \;\;\;\;U\_m\\ \end{array} \end{array} \]
          U_m = (fabs.f64 U)
          (FPCore (J K U_m)
           :precision binary64
           (let* ((t_0 (cos (/ K 2.0)))
                  (t_1
                   (*
                    (* (* -2.0 J) t_0)
                    (sqrt (+ 1.0 (pow (/ U_m (* (* 2.0 J) t_0)) 2.0))))))
             (if (<= t_1 -5e+306)
               (- U_m)
               (if (<= t_1 -1e-53) (* J -2.0) (if (<= t_1 -5e-270) (- U_m) U_m)))))
          U_m = fabs(U);
          double code(double J, double K, double U_m) {
          	double t_0 = cos((K / 2.0));
          	double t_1 = ((-2.0 * J) * t_0) * sqrt((1.0 + pow((U_m / ((2.0 * J) * t_0)), 2.0)));
          	double tmp;
          	if (t_1 <= -5e+306) {
          		tmp = -U_m;
          	} else if (t_1 <= -1e-53) {
          		tmp = J * -2.0;
          	} else if (t_1 <= -5e-270) {
          		tmp = -U_m;
          	} else {
          		tmp = U_m;
          	}
          	return tmp;
          }
          
          U_m =     private
          module fmin_fmax_functions
              implicit none
              private
              public fmax
              public fmin
          
              interface fmax
                  module procedure fmax88
                  module procedure fmax44
                  module procedure fmax84
                  module procedure fmax48
              end interface
              interface fmin
                  module procedure fmin88
                  module procedure fmin44
                  module procedure fmin84
                  module procedure fmin48
              end interface
          contains
              real(8) function fmax88(x, y) result (res)
                  real(8), intent (in) :: x
                  real(8), intent (in) :: y
                  res = merge(y, merge(x, max(x, y), y /= y), x /= x)
              end function
              real(4) function fmax44(x, y) result (res)
                  real(4), intent (in) :: x
                  real(4), intent (in) :: y
                  res = merge(y, merge(x, max(x, y), y /= y), x /= x)
              end function
              real(8) function fmax84(x, y) result(res)
                  real(8), intent (in) :: x
                  real(4), intent (in) :: y
                  res = merge(dble(y), merge(x, max(x, dble(y)), y /= y), x /= x)
              end function
              real(8) function fmax48(x, y) result(res)
                  real(4), intent (in) :: x
                  real(8), intent (in) :: y
                  res = merge(y, merge(dble(x), max(dble(x), y), y /= y), x /= x)
              end function
              real(8) function fmin88(x, y) result (res)
                  real(8), intent (in) :: x
                  real(8), intent (in) :: y
                  res = merge(y, merge(x, min(x, y), y /= y), x /= x)
              end function
              real(4) function fmin44(x, y) result (res)
                  real(4), intent (in) :: x
                  real(4), intent (in) :: y
                  res = merge(y, merge(x, min(x, y), y /= y), x /= x)
              end function
              real(8) function fmin84(x, y) result(res)
                  real(8), intent (in) :: x
                  real(4), intent (in) :: y
                  res = merge(dble(y), merge(x, min(x, dble(y)), y /= y), x /= x)
              end function
              real(8) function fmin48(x, y) result(res)
                  real(4), intent (in) :: x
                  real(8), intent (in) :: y
                  res = merge(y, merge(dble(x), min(dble(x), y), y /= y), x /= x)
              end function
          end module
          
          real(8) function code(j, k, u_m)
          use fmin_fmax_functions
              real(8), intent (in) :: j
              real(8), intent (in) :: k
              real(8), intent (in) :: u_m
              real(8) :: t_0
              real(8) :: t_1
              real(8) :: tmp
              t_0 = cos((k / 2.0d0))
              t_1 = (((-2.0d0) * j) * t_0) * sqrt((1.0d0 + ((u_m / ((2.0d0 * j) * t_0)) ** 2.0d0)))
              if (t_1 <= (-5d+306)) then
                  tmp = -u_m
              else if (t_1 <= (-1d-53)) then
                  tmp = j * (-2.0d0)
              else if (t_1 <= (-5d-270)) then
                  tmp = -u_m
              else
                  tmp = u_m
              end if
              code = tmp
          end function
          
          U_m = Math.abs(U);
          public static double code(double J, double K, double U_m) {
          	double t_0 = Math.cos((K / 2.0));
          	double t_1 = ((-2.0 * J) * t_0) * Math.sqrt((1.0 + Math.pow((U_m / ((2.0 * J) * t_0)), 2.0)));
          	double tmp;
          	if (t_1 <= -5e+306) {
          		tmp = -U_m;
          	} else if (t_1 <= -1e-53) {
          		tmp = J * -2.0;
          	} else if (t_1 <= -5e-270) {
          		tmp = -U_m;
          	} else {
          		tmp = U_m;
          	}
          	return tmp;
          }
          
          U_m = math.fabs(U)
          def code(J, K, U_m):
          	t_0 = math.cos((K / 2.0))
          	t_1 = ((-2.0 * J) * t_0) * math.sqrt((1.0 + math.pow((U_m / ((2.0 * J) * t_0)), 2.0)))
          	tmp = 0
          	if t_1 <= -5e+306:
          		tmp = -U_m
          	elif t_1 <= -1e-53:
          		tmp = J * -2.0
          	elif t_1 <= -5e-270:
          		tmp = -U_m
          	else:
          		tmp = U_m
          	return tmp
          
          U_m = abs(U)
          function code(J, K, U_m)
          	t_0 = cos(Float64(K / 2.0))
          	t_1 = Float64(Float64(Float64(-2.0 * J) * t_0) * sqrt(Float64(1.0 + (Float64(U_m / Float64(Float64(2.0 * J) * t_0)) ^ 2.0))))
          	tmp = 0.0
          	if (t_1 <= -5e+306)
          		tmp = Float64(-U_m);
          	elseif (t_1 <= -1e-53)
          		tmp = Float64(J * -2.0);
          	elseif (t_1 <= -5e-270)
          		tmp = Float64(-U_m);
          	else
          		tmp = U_m;
          	end
          	return tmp
          end
          
          U_m = abs(U);
          function tmp_2 = code(J, K, U_m)
          	t_0 = cos((K / 2.0));
          	t_1 = ((-2.0 * J) * t_0) * sqrt((1.0 + ((U_m / ((2.0 * J) * t_0)) ^ 2.0)));
          	tmp = 0.0;
          	if (t_1 <= -5e+306)
          		tmp = -U_m;
          	elseif (t_1 <= -1e-53)
          		tmp = J * -2.0;
          	elseif (t_1 <= -5e-270)
          		tmp = -U_m;
          	else
          		tmp = U_m;
          	end
          	tmp_2 = tmp;
          end
          
          U_m = N[Abs[U], $MachinePrecision]
          code[J_, K_, U$95$m_] := Block[{t$95$0 = N[Cos[N[(K / 2.0), $MachinePrecision]], $MachinePrecision]}, Block[{t$95$1 = N[(N[(N[(-2.0 * J), $MachinePrecision] * t$95$0), $MachinePrecision] * N[Sqrt[N[(1.0 + N[Power[N[(U$95$m / N[(N[(2.0 * J), $MachinePrecision] * t$95$0), $MachinePrecision]), $MachinePrecision], 2.0], $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]}, If[LessEqual[t$95$1, -5e+306], (-U$95$m), If[LessEqual[t$95$1, -1e-53], N[(J * -2.0), $MachinePrecision], If[LessEqual[t$95$1, -5e-270], (-U$95$m), U$95$m]]]]]
          
          \begin{array}{l}
          U_m = \left|U\right|
          
          \\
          \begin{array}{l}
          t_0 := \cos \left(\frac{K}{2}\right)\\
          t_1 := \left(\left(-2 \cdot J\right) \cdot t\_0\right) \cdot \sqrt{1 + {\left(\frac{U\_m}{\left(2 \cdot J\right) \cdot t\_0}\right)}^{2}}\\
          \mathbf{if}\;t\_1 \leq -5 \cdot 10^{+306}:\\
          \;\;\;\;-U\_m\\
          
          \mathbf{elif}\;t\_1 \leq -1 \cdot 10^{-53}:\\
          \;\;\;\;J \cdot -2\\
          
          \mathbf{elif}\;t\_1 \leq -5 \cdot 10^{-270}:\\
          \;\;\;\;-U\_m\\
          
          \mathbf{else}:\\
          \;\;\;\;U\_m\\
          
          
          \end{array}
          \end{array}
          
          Derivation
          1. Split input into 3 regimes
          2. if (*.f64 (*.f64 (*.f64 #s(literal -2 binary64) J) (cos.f64 (/.f64 K #s(literal 2 binary64)))) (sqrt.f64 (+.f64 #s(literal 1 binary64) (pow.f64 (/.f64 U (*.f64 (*.f64 #s(literal 2 binary64) J) (cos.f64 (/.f64 K #s(literal 2 binary64))))) #s(literal 2 binary64))))) < -4.99999999999999993e306 or -1.00000000000000003e-53 < (*.f64 (*.f64 (*.f64 #s(literal -2 binary64) J) (cos.f64 (/.f64 K #s(literal 2 binary64)))) (sqrt.f64 (+.f64 #s(literal 1 binary64) (pow.f64 (/.f64 U (*.f64 (*.f64 #s(literal 2 binary64) J) (cos.f64 (/.f64 K #s(literal 2 binary64))))) #s(literal 2 binary64))))) < -4.9999999999999998e-270

            1. Initial program 40.4%

              \[\left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)}\right)}^{2}} \]
            2. Add Preprocessing
            3. Taylor expanded in J around 0

              \[\leadsto \color{blue}{-1 \cdot U} \]
            4. Step-by-step derivation
              1. mul-1-negN/A

                \[\leadsto \mathsf{neg}\left(U\right) \]
              2. lower-neg.f6445.9

                \[\leadsto -U \]
            5. Applied rewrites45.9%

              \[\leadsto \color{blue}{-U} \]

            if -4.99999999999999993e306 < (*.f64 (*.f64 (*.f64 #s(literal -2 binary64) J) (cos.f64 (/.f64 K #s(literal 2 binary64)))) (sqrt.f64 (+.f64 #s(literal 1 binary64) (pow.f64 (/.f64 U (*.f64 (*.f64 #s(literal 2 binary64) J) (cos.f64 (/.f64 K #s(literal 2 binary64))))) #s(literal 2 binary64))))) < -1.00000000000000003e-53

            1. Initial program 99.8%

              \[\left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)}\right)}^{2}} \]
            2. Add Preprocessing
            3. Taylor expanded in K around 0

              \[\leadsto \color{blue}{-2 \cdot \left(J \cdot \sqrt{1 + \frac{1}{4} \cdot \frac{{U}^{2}}{{J}^{2}}}\right)} \]
            4. Step-by-step derivation
              1. associate-*r*N/A

                \[\leadsto \left(-2 \cdot J\right) \cdot \color{blue}{\sqrt{1 + \frac{1}{4} \cdot \frac{{U}^{2}}{{J}^{2}}}} \]
              2. lower-*.f64N/A

                \[\leadsto \left(-2 \cdot J\right) \cdot \color{blue}{\sqrt{1 + \frac{1}{4} \cdot \frac{{U}^{2}}{{J}^{2}}}} \]
              3. *-commutativeN/A

                \[\leadsto \left(J \cdot -2\right) \cdot \sqrt{\color{blue}{1 + \frac{1}{4} \cdot \frac{{U}^{2}}{{J}^{2}}}} \]
              4. lower-*.f64N/A

                \[\leadsto \left(J \cdot -2\right) \cdot \sqrt{\color{blue}{1 + \frac{1}{4} \cdot \frac{{U}^{2}}{{J}^{2}}}} \]
              5. lower-sqrt.f64N/A

                \[\leadsto \left(J \cdot -2\right) \cdot \sqrt{1 + \frac{1}{4} \cdot \frac{{U}^{2}}{{J}^{2}}} \]
              6. +-commutativeN/A

                \[\leadsto \left(J \cdot -2\right) \cdot \sqrt{\frac{1}{4} \cdot \frac{{U}^{2}}{{J}^{2}} + 1} \]
              7. *-commutativeN/A

                \[\leadsto \left(J \cdot -2\right) \cdot \sqrt{\frac{{U}^{2}}{{J}^{2}} \cdot \frac{1}{4} + 1} \]
              8. lower-fma.f64N/A

                \[\leadsto \left(J \cdot -2\right) \cdot \sqrt{\mathsf{fma}\left(\frac{{U}^{2}}{{J}^{2}}, \frac{1}{4}, 1\right)} \]
              9. lower-/.f64N/A

                \[\leadsto \left(J \cdot -2\right) \cdot \sqrt{\mathsf{fma}\left(\frac{{U}^{2}}{{J}^{2}}, \frac{1}{4}, 1\right)} \]
              10. unpow2N/A

                \[\leadsto \left(J \cdot -2\right) \cdot \sqrt{\mathsf{fma}\left(\frac{U \cdot U}{{J}^{2}}, \frac{1}{4}, 1\right)} \]
              11. lower-*.f64N/A

                \[\leadsto \left(J \cdot -2\right) \cdot \sqrt{\mathsf{fma}\left(\frac{U \cdot U}{{J}^{2}}, \frac{1}{4}, 1\right)} \]
              12. unpow2N/A

                \[\leadsto \left(J \cdot -2\right) \cdot \sqrt{\mathsf{fma}\left(\frac{U \cdot U}{J \cdot J}, \frac{1}{4}, 1\right)} \]
              13. lower-*.f6452.7

                \[\leadsto \left(J \cdot -2\right) \cdot \sqrt{\mathsf{fma}\left(\frac{U \cdot U}{J \cdot J}, 0.25, 1\right)} \]
            5. Applied rewrites52.7%

              \[\leadsto \color{blue}{\left(J \cdot -2\right) \cdot \sqrt{\mathsf{fma}\left(\frac{U \cdot U}{J \cdot J}, 0.25, 1\right)}} \]
            6. Taylor expanded in J around inf

              \[\leadsto -2 \cdot \color{blue}{J} \]
            7. Step-by-step derivation
              1. *-commutativeN/A

                \[\leadsto J \cdot -2 \]
              2. lift-*.f6449.8

                \[\leadsto J \cdot -2 \]
            8. Applied rewrites49.8%

              \[\leadsto J \cdot \color{blue}{-2} \]

            if -4.9999999999999998e-270 < (*.f64 (*.f64 (*.f64 #s(literal -2 binary64) J) (cos.f64 (/.f64 K #s(literal 2 binary64)))) (sqrt.f64 (+.f64 #s(literal 1 binary64) (pow.f64 (/.f64 U (*.f64 (*.f64 #s(literal 2 binary64) J) (cos.f64 (/.f64 K #s(literal 2 binary64))))) #s(literal 2 binary64)))))

            1. Initial program 72.7%

              \[\left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)}\right)}^{2}} \]
            2. Add Preprocessing
            3. Taylor expanded in U around -inf

              \[\leadsto \color{blue}{U} \]
            4. Step-by-step derivation
              1. Applied rewrites26.7%

                \[\leadsto \color{blue}{U} \]
            5. Recombined 3 regimes into one program.
            6. Add Preprocessing

            Alternative 6: 51.8% accurate, 1.0× speedup?

            \[\begin{array}{l} U_m = \left|U\right| \\ \begin{array}{l} t_0 := \cos \left(\frac{K}{2}\right)\\ \mathbf{if}\;\left(\left(-2 \cdot J\right) \cdot t\_0\right) \cdot \sqrt{1 + {\left(\frac{U\_m}{\left(2 \cdot J\right) \cdot t\_0}\right)}^{2}} \leq -5 \cdot 10^{-270}:\\ \;\;\;\;-U\_m\\ \mathbf{else}:\\ \;\;\;\;U\_m\\ \end{array} \end{array} \]
            U_m = (fabs.f64 U)
            (FPCore (J K U_m)
             :precision binary64
             (let* ((t_0 (cos (/ K 2.0))))
               (if (<=
                    (*
                     (* (* -2.0 J) t_0)
                     (sqrt (+ 1.0 (pow (/ U_m (* (* 2.0 J) t_0)) 2.0))))
                    -5e-270)
                 (- U_m)
                 U_m)))
            U_m = fabs(U);
            double code(double J, double K, double U_m) {
            	double t_0 = cos((K / 2.0));
            	double tmp;
            	if ((((-2.0 * J) * t_0) * sqrt((1.0 + pow((U_m / ((2.0 * J) * t_0)), 2.0)))) <= -5e-270) {
            		tmp = -U_m;
            	} else {
            		tmp = U_m;
            	}
            	return tmp;
            }
            
            U_m =     private
            module fmin_fmax_functions
                implicit none
                private
                public fmax
                public fmin
            
                interface fmax
                    module procedure fmax88
                    module procedure fmax44
                    module procedure fmax84
                    module procedure fmax48
                end interface
                interface fmin
                    module procedure fmin88
                    module procedure fmin44
                    module procedure fmin84
                    module procedure fmin48
                end interface
            contains
                real(8) function fmax88(x, y) result (res)
                    real(8), intent (in) :: x
                    real(8), intent (in) :: y
                    res = merge(y, merge(x, max(x, y), y /= y), x /= x)
                end function
                real(4) function fmax44(x, y) result (res)
                    real(4), intent (in) :: x
                    real(4), intent (in) :: y
                    res = merge(y, merge(x, max(x, y), y /= y), x /= x)
                end function
                real(8) function fmax84(x, y) result(res)
                    real(8), intent (in) :: x
                    real(4), intent (in) :: y
                    res = merge(dble(y), merge(x, max(x, dble(y)), y /= y), x /= x)
                end function
                real(8) function fmax48(x, y) result(res)
                    real(4), intent (in) :: x
                    real(8), intent (in) :: y
                    res = merge(y, merge(dble(x), max(dble(x), y), y /= y), x /= x)
                end function
                real(8) function fmin88(x, y) result (res)
                    real(8), intent (in) :: x
                    real(8), intent (in) :: y
                    res = merge(y, merge(x, min(x, y), y /= y), x /= x)
                end function
                real(4) function fmin44(x, y) result (res)
                    real(4), intent (in) :: x
                    real(4), intent (in) :: y
                    res = merge(y, merge(x, min(x, y), y /= y), x /= x)
                end function
                real(8) function fmin84(x, y) result(res)
                    real(8), intent (in) :: x
                    real(4), intent (in) :: y
                    res = merge(dble(y), merge(x, min(x, dble(y)), y /= y), x /= x)
                end function
                real(8) function fmin48(x, y) result(res)
                    real(4), intent (in) :: x
                    real(8), intent (in) :: y
                    res = merge(y, merge(dble(x), min(dble(x), y), y /= y), x /= x)
                end function
            end module
            
            real(8) function code(j, k, u_m)
            use fmin_fmax_functions
                real(8), intent (in) :: j
                real(8), intent (in) :: k
                real(8), intent (in) :: u_m
                real(8) :: t_0
                real(8) :: tmp
                t_0 = cos((k / 2.0d0))
                if (((((-2.0d0) * j) * t_0) * sqrt((1.0d0 + ((u_m / ((2.0d0 * j) * t_0)) ** 2.0d0)))) <= (-5d-270)) then
                    tmp = -u_m
                else
                    tmp = u_m
                end if
                code = tmp
            end function
            
            U_m = Math.abs(U);
            public static double code(double J, double K, double U_m) {
            	double t_0 = Math.cos((K / 2.0));
            	double tmp;
            	if ((((-2.0 * J) * t_0) * Math.sqrt((1.0 + Math.pow((U_m / ((2.0 * J) * t_0)), 2.0)))) <= -5e-270) {
            		tmp = -U_m;
            	} else {
            		tmp = U_m;
            	}
            	return tmp;
            }
            
            U_m = math.fabs(U)
            def code(J, K, U_m):
            	t_0 = math.cos((K / 2.0))
            	tmp = 0
            	if (((-2.0 * J) * t_0) * math.sqrt((1.0 + math.pow((U_m / ((2.0 * J) * t_0)), 2.0)))) <= -5e-270:
            		tmp = -U_m
            	else:
            		tmp = U_m
            	return tmp
            
            U_m = abs(U)
            function code(J, K, U_m)
            	t_0 = cos(Float64(K / 2.0))
            	tmp = 0.0
            	if (Float64(Float64(Float64(-2.0 * J) * t_0) * sqrt(Float64(1.0 + (Float64(U_m / Float64(Float64(2.0 * J) * t_0)) ^ 2.0)))) <= -5e-270)
            		tmp = Float64(-U_m);
            	else
            		tmp = U_m;
            	end
            	return tmp
            end
            
            U_m = abs(U);
            function tmp_2 = code(J, K, U_m)
            	t_0 = cos((K / 2.0));
            	tmp = 0.0;
            	if ((((-2.0 * J) * t_0) * sqrt((1.0 + ((U_m / ((2.0 * J) * t_0)) ^ 2.0)))) <= -5e-270)
            		tmp = -U_m;
            	else
            		tmp = U_m;
            	end
            	tmp_2 = tmp;
            end
            
            U_m = N[Abs[U], $MachinePrecision]
            code[J_, K_, U$95$m_] := Block[{t$95$0 = N[Cos[N[(K / 2.0), $MachinePrecision]], $MachinePrecision]}, If[LessEqual[N[(N[(N[(-2.0 * J), $MachinePrecision] * t$95$0), $MachinePrecision] * N[Sqrt[N[(1.0 + N[Power[N[(U$95$m / N[(N[(2.0 * J), $MachinePrecision] * t$95$0), $MachinePrecision]), $MachinePrecision], 2.0], $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision], -5e-270], (-U$95$m), U$95$m]]
            
            \begin{array}{l}
            U_m = \left|U\right|
            
            \\
            \begin{array}{l}
            t_0 := \cos \left(\frac{K}{2}\right)\\
            \mathbf{if}\;\left(\left(-2 \cdot J\right) \cdot t\_0\right) \cdot \sqrt{1 + {\left(\frac{U\_m}{\left(2 \cdot J\right) \cdot t\_0}\right)}^{2}} \leq -5 \cdot 10^{-270}:\\
            \;\;\;\;-U\_m\\
            
            \mathbf{else}:\\
            \;\;\;\;U\_m\\
            
            
            \end{array}
            \end{array}
            
            Derivation
            1. Split input into 2 regimes
            2. if (*.f64 (*.f64 (*.f64 #s(literal -2 binary64) J) (cos.f64 (/.f64 K #s(literal 2 binary64)))) (sqrt.f64 (+.f64 #s(literal 1 binary64) (pow.f64 (/.f64 U (*.f64 (*.f64 #s(literal 2 binary64) J) (cos.f64 (/.f64 K #s(literal 2 binary64))))) #s(literal 2 binary64))))) < -4.9999999999999998e-270

              1. Initial program 70.5%

                \[\left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)}\right)}^{2}} \]
              2. Add Preprocessing
              3. Taylor expanded in J around 0

                \[\leadsto \color{blue}{-1 \cdot U} \]
              4. Step-by-step derivation
                1. mul-1-negN/A

                  \[\leadsto \mathsf{neg}\left(U\right) \]
                2. lower-neg.f6428.2

                  \[\leadsto -U \]
              5. Applied rewrites28.2%

                \[\leadsto \color{blue}{-U} \]

              if -4.9999999999999998e-270 < (*.f64 (*.f64 (*.f64 #s(literal -2 binary64) J) (cos.f64 (/.f64 K #s(literal 2 binary64)))) (sqrt.f64 (+.f64 #s(literal 1 binary64) (pow.f64 (/.f64 U (*.f64 (*.f64 #s(literal 2 binary64) J) (cos.f64 (/.f64 K #s(literal 2 binary64))))) #s(literal 2 binary64)))))

              1. Initial program 72.7%

                \[\left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)}\right)}^{2}} \]
              2. Add Preprocessing
              3. Taylor expanded in U around -inf

                \[\leadsto \color{blue}{U} \]
              4. Step-by-step derivation
                1. Applied rewrites26.7%

                  \[\leadsto \color{blue}{U} \]
              5. Recombined 2 regimes into one program.
              6. Add Preprocessing

              Alternative 7: 26.6% accurate, 373.0× speedup?

              \[\begin{array}{l} U_m = \left|U\right| \\ U\_m \end{array} \]
              U_m = (fabs.f64 U)
              (FPCore (J K U_m) :precision binary64 U_m)
              U_m = fabs(U);
              double code(double J, double K, double U_m) {
              	return U_m;
              }
              
              U_m =     private
              module fmin_fmax_functions
                  implicit none
                  private
                  public fmax
                  public fmin
              
                  interface fmax
                      module procedure fmax88
                      module procedure fmax44
                      module procedure fmax84
                      module procedure fmax48
                  end interface
                  interface fmin
                      module procedure fmin88
                      module procedure fmin44
                      module procedure fmin84
                      module procedure fmin48
                  end interface
              contains
                  real(8) function fmax88(x, y) result (res)
                      real(8), intent (in) :: x
                      real(8), intent (in) :: y
                      res = merge(y, merge(x, max(x, y), y /= y), x /= x)
                  end function
                  real(4) function fmax44(x, y) result (res)
                      real(4), intent (in) :: x
                      real(4), intent (in) :: y
                      res = merge(y, merge(x, max(x, y), y /= y), x /= x)
                  end function
                  real(8) function fmax84(x, y) result(res)
                      real(8), intent (in) :: x
                      real(4), intent (in) :: y
                      res = merge(dble(y), merge(x, max(x, dble(y)), y /= y), x /= x)
                  end function
                  real(8) function fmax48(x, y) result(res)
                      real(4), intent (in) :: x
                      real(8), intent (in) :: y
                      res = merge(y, merge(dble(x), max(dble(x), y), y /= y), x /= x)
                  end function
                  real(8) function fmin88(x, y) result (res)
                      real(8), intent (in) :: x
                      real(8), intent (in) :: y
                      res = merge(y, merge(x, min(x, y), y /= y), x /= x)
                  end function
                  real(4) function fmin44(x, y) result (res)
                      real(4), intent (in) :: x
                      real(4), intent (in) :: y
                      res = merge(y, merge(x, min(x, y), y /= y), x /= x)
                  end function
                  real(8) function fmin84(x, y) result(res)
                      real(8), intent (in) :: x
                      real(4), intent (in) :: y
                      res = merge(dble(y), merge(x, min(x, dble(y)), y /= y), x /= x)
                  end function
                  real(8) function fmin48(x, y) result(res)
                      real(4), intent (in) :: x
                      real(8), intent (in) :: y
                      res = merge(y, merge(dble(x), min(dble(x), y), y /= y), x /= x)
                  end function
              end module
              
              real(8) function code(j, k, u_m)
              use fmin_fmax_functions
                  real(8), intent (in) :: j
                  real(8), intent (in) :: k
                  real(8), intent (in) :: u_m
                  code = u_m
              end function
              
              U_m = Math.abs(U);
              public static double code(double J, double K, double U_m) {
              	return U_m;
              }
              
              U_m = math.fabs(U)
              def code(J, K, U_m):
              	return U_m
              
              U_m = abs(U)
              function code(J, K, U_m)
              	return U_m
              end
              
              U_m = abs(U);
              function tmp = code(J, K, U_m)
              	tmp = U_m;
              end
              
              U_m = N[Abs[U], $MachinePrecision]
              code[J_, K_, U$95$m_] := U$95$m
              
              \begin{array}{l}
              U_m = \left|U\right|
              
              \\
              U\_m
              \end{array}
              
              Derivation
              1. Initial program 71.6%

                \[\left(\left(-2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)\right) \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot \cos \left(\frac{K}{2}\right)}\right)}^{2}} \]
              2. Add Preprocessing
              3. Taylor expanded in U around -inf

                \[\leadsto \color{blue}{U} \]
              4. Step-by-step derivation
                1. Applied rewrites26.2%

                  \[\leadsto \color{blue}{U} \]
                2. Add Preprocessing

                Reproduce

                ?
                herbie shell --seed 2025073 
                (FPCore (J K U)
                  :name "Maksimov and Kolovsky, Equation (3)"
                  :precision binary64
                  (* (* (* -2.0 J) (cos (/ K 2.0))) (sqrt (+ 1.0 (pow (/ U (* (* 2.0 J) (cos (/ K 2.0)))) 2.0)))))