Equirectangular approximation to distance on a great circle

Percentage Accurate: 59.6% → 63.3%
Time: 3.0s
Alternatives: 9
Speedup: 1.0×

Specification

?
\[\mathsf{TRUE}\left(\right)\]
\[\begin{array}{l} \\ \begin{array}{l} t_0 := \left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\\ R \cdot \sqrt{t\_0 \cdot t\_0 + \left(\phi_1 - \phi_2\right) \cdot \left(\phi_1 - \phi_2\right)} \end{array} \end{array} \]
(FPCore (R lambda1 lambda2 phi1 phi2)
 :precision binary64
 (let* ((t_0 (* (- lambda1 lambda2) (cos (/ (+ phi1 phi2) 2.0)))))
   (* R (sqrt (+ (* t_0 t_0) (* (- phi1 phi2) (- phi1 phi2)))))))
double code(double R, double lambda1, double lambda2, double phi1, double phi2) {
	double t_0 = (lambda1 - lambda2) * cos(((phi1 + phi2) / 2.0));
	return R * sqrt(((t_0 * t_0) + ((phi1 - phi2) * (phi1 - phi2))));
}
real(8) function code(r, lambda1, lambda2, phi1, phi2)
    real(8), intent (in) :: r
    real(8), intent (in) :: lambda1
    real(8), intent (in) :: lambda2
    real(8), intent (in) :: phi1
    real(8), intent (in) :: phi2
    real(8) :: t_0
    t_0 = (lambda1 - lambda2) * cos(((phi1 + phi2) / 2.0d0))
    code = r * sqrt(((t_0 * t_0) + ((phi1 - phi2) * (phi1 - phi2))))
end function
public static double code(double R, double lambda1, double lambda2, double phi1, double phi2) {
	double t_0 = (lambda1 - lambda2) * Math.cos(((phi1 + phi2) / 2.0));
	return R * Math.sqrt(((t_0 * t_0) + ((phi1 - phi2) * (phi1 - phi2))));
}
def code(R, lambda1, lambda2, phi1, phi2):
	t_0 = (lambda1 - lambda2) * math.cos(((phi1 + phi2) / 2.0))
	return R * math.sqrt(((t_0 * t_0) + ((phi1 - phi2) * (phi1 - phi2))))
function code(R, lambda1, lambda2, phi1, phi2)
	t_0 = Float64(Float64(lambda1 - lambda2) * cos(Float64(Float64(phi1 + phi2) / 2.0)))
	return Float64(R * sqrt(Float64(Float64(t_0 * t_0) + Float64(Float64(phi1 - phi2) * Float64(phi1 - phi2)))))
end
function tmp = code(R, lambda1, lambda2, phi1, phi2)
	t_0 = (lambda1 - lambda2) * cos(((phi1 + phi2) / 2.0));
	tmp = R * sqrt(((t_0 * t_0) + ((phi1 - phi2) * (phi1 - phi2))));
end
code[R_, lambda1_, lambda2_, phi1_, phi2_] := Block[{t$95$0 = N[(N[(lambda1 - lambda2), $MachinePrecision] * N[Cos[N[(N[(phi1 + phi2), $MachinePrecision] / 2.0), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]}, N[(R * N[Sqrt[N[(N[(t$95$0 * t$95$0), $MachinePrecision] + N[(N[(phi1 - phi2), $MachinePrecision] * N[(phi1 - phi2), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\\
R \cdot \sqrt{t\_0 \cdot t\_0 + \left(\phi_1 - \phi_2\right) \cdot \left(\phi_1 - \phi_2\right)}
\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 9 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: 59.6% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\\ R \cdot \sqrt{t\_0 \cdot t\_0 + \left(\phi_1 - \phi_2\right) \cdot \left(\phi_1 - \phi_2\right)} \end{array} \end{array} \]
(FPCore (R lambda1 lambda2 phi1 phi2)
 :precision binary64
 (let* ((t_0 (* (- lambda1 lambda2) (cos (/ (+ phi1 phi2) 2.0)))))
   (* R (sqrt (+ (* t_0 t_0) (* (- phi1 phi2) (- phi1 phi2)))))))
double code(double R, double lambda1, double lambda2, double phi1, double phi2) {
	double t_0 = (lambda1 - lambda2) * cos(((phi1 + phi2) / 2.0));
	return R * sqrt(((t_0 * t_0) + ((phi1 - phi2) * (phi1 - phi2))));
}
real(8) function code(r, lambda1, lambda2, phi1, phi2)
    real(8), intent (in) :: r
    real(8), intent (in) :: lambda1
    real(8), intent (in) :: lambda2
    real(8), intent (in) :: phi1
    real(8), intent (in) :: phi2
    real(8) :: t_0
    t_0 = (lambda1 - lambda2) * cos(((phi1 + phi2) / 2.0d0))
    code = r * sqrt(((t_0 * t_0) + ((phi1 - phi2) * (phi1 - phi2))))
end function
public static double code(double R, double lambda1, double lambda2, double phi1, double phi2) {
	double t_0 = (lambda1 - lambda2) * Math.cos(((phi1 + phi2) / 2.0));
	return R * Math.sqrt(((t_0 * t_0) + ((phi1 - phi2) * (phi1 - phi2))));
}
def code(R, lambda1, lambda2, phi1, phi2):
	t_0 = (lambda1 - lambda2) * math.cos(((phi1 + phi2) / 2.0))
	return R * math.sqrt(((t_0 * t_0) + ((phi1 - phi2) * (phi1 - phi2))))
function code(R, lambda1, lambda2, phi1, phi2)
	t_0 = Float64(Float64(lambda1 - lambda2) * cos(Float64(Float64(phi1 + phi2) / 2.0)))
	return Float64(R * sqrt(Float64(Float64(t_0 * t_0) + Float64(Float64(phi1 - phi2) * Float64(phi1 - phi2)))))
end
function tmp = code(R, lambda1, lambda2, phi1, phi2)
	t_0 = (lambda1 - lambda2) * cos(((phi1 + phi2) / 2.0));
	tmp = R * sqrt(((t_0 * t_0) + ((phi1 - phi2) * (phi1 - phi2))));
end
code[R_, lambda1_, lambda2_, phi1_, phi2_] := Block[{t$95$0 = N[(N[(lambda1 - lambda2), $MachinePrecision] * N[Cos[N[(N[(phi1 + phi2), $MachinePrecision] / 2.0), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]}, N[(R * N[Sqrt[N[(N[(t$95$0 * t$95$0), $MachinePrecision] + N[(N[(phi1 - phi2), $MachinePrecision] * N[(phi1 - phi2), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\\
R \cdot \sqrt{t\_0 \cdot t\_0 + \left(\phi_1 - \phi_2\right) \cdot \left(\phi_1 - \phi_2\right)}
\end{array}
\end{array}

Alternative 1: 63.3% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\\ \mathbf{if}\;\lambda_1 - \lambda_2 \leq 2.1 \cdot 10^{+139}:\\ \;\;\;\;R \cdot \sqrt{t\_0 \cdot t\_0 + \left(\phi_1 - \phi_2\right) \cdot \left(\phi_1 - \phi_2\right)}\\ \mathbf{else}:\\ \;\;\;\;R \cdot \left(\lambda_1 - \lambda_2\right)\\ \end{array} \end{array} \]
(FPCore (R lambda1 lambda2 phi1 phi2)
 :precision binary64
 (let* ((t_0 (* (- lambda1 lambda2) (cos (/ (+ phi1 phi2) 2.0)))))
   (if (<= (- lambda1 lambda2) 2.1e+139)
     (* R (sqrt (+ (* t_0 t_0) (* (- phi1 phi2) (- phi1 phi2)))))
     (* R (- lambda1 lambda2)))))
double code(double R, double lambda1, double lambda2, double phi1, double phi2) {
	double t_0 = (lambda1 - lambda2) * cos(((phi1 + phi2) / 2.0));
	double tmp;
	if ((lambda1 - lambda2) <= 2.1e+139) {
		tmp = R * sqrt(((t_0 * t_0) + ((phi1 - phi2) * (phi1 - phi2))));
	} else {
		tmp = R * (lambda1 - lambda2);
	}
	return tmp;
}
real(8) function code(r, lambda1, lambda2, phi1, phi2)
    real(8), intent (in) :: r
    real(8), intent (in) :: lambda1
    real(8), intent (in) :: lambda2
    real(8), intent (in) :: phi1
    real(8), intent (in) :: phi2
    real(8) :: t_0
    real(8) :: tmp
    t_0 = (lambda1 - lambda2) * cos(((phi1 + phi2) / 2.0d0))
    if ((lambda1 - lambda2) <= 2.1d+139) then
        tmp = r * sqrt(((t_0 * t_0) + ((phi1 - phi2) * (phi1 - phi2))))
    else
        tmp = r * (lambda1 - lambda2)
    end if
    code = tmp
end function
public static double code(double R, double lambda1, double lambda2, double phi1, double phi2) {
	double t_0 = (lambda1 - lambda2) * Math.cos(((phi1 + phi2) / 2.0));
	double tmp;
	if ((lambda1 - lambda2) <= 2.1e+139) {
		tmp = R * Math.sqrt(((t_0 * t_0) + ((phi1 - phi2) * (phi1 - phi2))));
	} else {
		tmp = R * (lambda1 - lambda2);
	}
	return tmp;
}
def code(R, lambda1, lambda2, phi1, phi2):
	t_0 = (lambda1 - lambda2) * math.cos(((phi1 + phi2) / 2.0))
	tmp = 0
	if (lambda1 - lambda2) <= 2.1e+139:
		tmp = R * math.sqrt(((t_0 * t_0) + ((phi1 - phi2) * (phi1 - phi2))))
	else:
		tmp = R * (lambda1 - lambda2)
	return tmp
function code(R, lambda1, lambda2, phi1, phi2)
	t_0 = Float64(Float64(lambda1 - lambda2) * cos(Float64(Float64(phi1 + phi2) / 2.0)))
	tmp = 0.0
	if (Float64(lambda1 - lambda2) <= 2.1e+139)
		tmp = Float64(R * sqrt(Float64(Float64(t_0 * t_0) + Float64(Float64(phi1 - phi2) * Float64(phi1 - phi2)))));
	else
		tmp = Float64(R * Float64(lambda1 - lambda2));
	end
	return tmp
end
function tmp_2 = code(R, lambda1, lambda2, phi1, phi2)
	t_0 = (lambda1 - lambda2) * cos(((phi1 + phi2) / 2.0));
	tmp = 0.0;
	if ((lambda1 - lambda2) <= 2.1e+139)
		tmp = R * sqrt(((t_0 * t_0) + ((phi1 - phi2) * (phi1 - phi2))));
	else
		tmp = R * (lambda1 - lambda2);
	end
	tmp_2 = tmp;
end
code[R_, lambda1_, lambda2_, phi1_, phi2_] := Block[{t$95$0 = N[(N[(lambda1 - lambda2), $MachinePrecision] * N[Cos[N[(N[(phi1 + phi2), $MachinePrecision] / 2.0), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]}, If[LessEqual[N[(lambda1 - lambda2), $MachinePrecision], 2.1e+139], N[(R * N[Sqrt[N[(N[(t$95$0 * t$95$0), $MachinePrecision] + N[(N[(phi1 - phi2), $MachinePrecision] * N[(phi1 - phi2), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision], N[(R * N[(lambda1 - lambda2), $MachinePrecision]), $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\\
\mathbf{if}\;\lambda_1 - \lambda_2 \leq 2.1 \cdot 10^{+139}:\\
\;\;\;\;R \cdot \sqrt{t\_0 \cdot t\_0 + \left(\phi_1 - \phi_2\right) \cdot \left(\phi_1 - \phi_2\right)}\\

\mathbf{else}:\\
\;\;\;\;R \cdot \left(\lambda_1 - \lambda_2\right)\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (-.f64 lambda1 lambda2) < 2.0999999999999999e139

    1. Initial program 67.3%

      \[R \cdot \sqrt{\left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) \cdot \left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) + \left(\phi_1 - \phi_2\right) \cdot \left(\phi_1 - \phi_2\right)} \]
    2. Add Preprocessing

    if 2.0999999999999999e139 < (-.f64 lambda1 lambda2)

    1. Initial program 39.0%

      \[R \cdot \sqrt{\left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) \cdot \left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) + \left(\phi_1 - \phi_2\right) \cdot \left(\phi_1 - \phi_2\right)} \]
    2. Add Preprocessing
    3. Taylor expanded in lambda1 around 0

      \[\leadsto R \cdot \color{blue}{\sqrt{{\lambda_2}^{2} \cdot {\cos \left(\frac{1}{2} \cdot \left(\phi_1 + \phi_2\right)\right)}^{2} + {\left(\phi_1 - \phi_2\right)}^{2}}} \]
    4. Applied rewrites47.9%

      \[\leadsto R \cdot \color{blue}{\left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right)} \]
    5. Taylor expanded in lambda1 around 0

      \[\leadsto R \cdot \left(-1 \cdot \left(\lambda_2 \cdot \cos \left(\frac{1}{2} \cdot \left(\phi_1 + \phi_2\right)\right)\right) + \color{blue}{\lambda_1 \cdot \cos \left(\frac{1}{2} \cdot \left(\phi_1 + \phi_2\right)\right)}\right) \]
    6. Applied rewrites37.2%

      \[\leadsto R \cdot \left(\left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) \cdot \left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) + \color{blue}{\left(\phi_1 - \phi_2\right) \cdot \left(\phi_1 - \phi_2\right)}\right) \]
    7. Taylor expanded in lambda1 around 0

      \[\leadsto R \cdot \color{blue}{\sqrt{{\lambda_2}^{2} \cdot {\cos \left(\frac{1}{2} \cdot \left(\phi_1 + \phi_2\right)\right)}^{2} + {\left(\phi_1 - \phi_2\right)}^{2}}} \]
    8. Applied rewrites59.4%

      \[\leadsto R \cdot \color{blue}{\left(\lambda_1 - \lambda_2\right)} \]
  3. Recombined 2 regimes into one program.
  4. Add Preprocessing

Alternative 2: 44.4% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\\ \mathbf{if}\;\lambda_1 - \lambda_2 \leq -1.1 \cdot 10^{-12}:\\ \;\;\;\;R \cdot \left(t\_0 \cdot t\_0 + \left(\phi_1 - \phi_2\right) \cdot \left(\phi_1 - \phi_2\right)\right)\\ \mathbf{elif}\;\lambda_1 - \lambda_2 \leq 4 \cdot 10^{-50}:\\ \;\;\;\;R \cdot \left(\phi_1 + \phi_2\right)\\ \mathbf{else}:\\ \;\;\;\;R \cdot \left(\lambda_1 - \lambda_2\right)\\ \end{array} \end{array} \]
(FPCore (R lambda1 lambda2 phi1 phi2)
 :precision binary64
 (let* ((t_0 (* (- lambda1 lambda2) (cos (/ (+ phi1 phi2) 2.0)))))
   (if (<= (- lambda1 lambda2) -1.1e-12)
     (* R (+ (* t_0 t_0) (* (- phi1 phi2) (- phi1 phi2))))
     (if (<= (- lambda1 lambda2) 4e-50)
       (* R (+ phi1 phi2))
       (* R (- lambda1 lambda2))))))
double code(double R, double lambda1, double lambda2, double phi1, double phi2) {
	double t_0 = (lambda1 - lambda2) * cos(((phi1 + phi2) / 2.0));
	double tmp;
	if ((lambda1 - lambda2) <= -1.1e-12) {
		tmp = R * ((t_0 * t_0) + ((phi1 - phi2) * (phi1 - phi2)));
	} else if ((lambda1 - lambda2) <= 4e-50) {
		tmp = R * (phi1 + phi2);
	} else {
		tmp = R * (lambda1 - lambda2);
	}
	return tmp;
}
real(8) function code(r, lambda1, lambda2, phi1, phi2)
    real(8), intent (in) :: r
    real(8), intent (in) :: lambda1
    real(8), intent (in) :: lambda2
    real(8), intent (in) :: phi1
    real(8), intent (in) :: phi2
    real(8) :: t_0
    real(8) :: tmp
    t_0 = (lambda1 - lambda2) * cos(((phi1 + phi2) / 2.0d0))
    if ((lambda1 - lambda2) <= (-1.1d-12)) then
        tmp = r * ((t_0 * t_0) + ((phi1 - phi2) * (phi1 - phi2)))
    else if ((lambda1 - lambda2) <= 4d-50) then
        tmp = r * (phi1 + phi2)
    else
        tmp = r * (lambda1 - lambda2)
    end if
    code = tmp
end function
public static double code(double R, double lambda1, double lambda2, double phi1, double phi2) {
	double t_0 = (lambda1 - lambda2) * Math.cos(((phi1 + phi2) / 2.0));
	double tmp;
	if ((lambda1 - lambda2) <= -1.1e-12) {
		tmp = R * ((t_0 * t_0) + ((phi1 - phi2) * (phi1 - phi2)));
	} else if ((lambda1 - lambda2) <= 4e-50) {
		tmp = R * (phi1 + phi2);
	} else {
		tmp = R * (lambda1 - lambda2);
	}
	return tmp;
}
def code(R, lambda1, lambda2, phi1, phi2):
	t_0 = (lambda1 - lambda2) * math.cos(((phi1 + phi2) / 2.0))
	tmp = 0
	if (lambda1 - lambda2) <= -1.1e-12:
		tmp = R * ((t_0 * t_0) + ((phi1 - phi2) * (phi1 - phi2)))
	elif (lambda1 - lambda2) <= 4e-50:
		tmp = R * (phi1 + phi2)
	else:
		tmp = R * (lambda1 - lambda2)
	return tmp
function code(R, lambda1, lambda2, phi1, phi2)
	t_0 = Float64(Float64(lambda1 - lambda2) * cos(Float64(Float64(phi1 + phi2) / 2.0)))
	tmp = 0.0
	if (Float64(lambda1 - lambda2) <= -1.1e-12)
		tmp = Float64(R * Float64(Float64(t_0 * t_0) + Float64(Float64(phi1 - phi2) * Float64(phi1 - phi2))));
	elseif (Float64(lambda1 - lambda2) <= 4e-50)
		tmp = Float64(R * Float64(phi1 + phi2));
	else
		tmp = Float64(R * Float64(lambda1 - lambda2));
	end
	return tmp
end
function tmp_2 = code(R, lambda1, lambda2, phi1, phi2)
	t_0 = (lambda1 - lambda2) * cos(((phi1 + phi2) / 2.0));
	tmp = 0.0;
	if ((lambda1 - lambda2) <= -1.1e-12)
		tmp = R * ((t_0 * t_0) + ((phi1 - phi2) * (phi1 - phi2)));
	elseif ((lambda1 - lambda2) <= 4e-50)
		tmp = R * (phi1 + phi2);
	else
		tmp = R * (lambda1 - lambda2);
	end
	tmp_2 = tmp;
end
code[R_, lambda1_, lambda2_, phi1_, phi2_] := Block[{t$95$0 = N[(N[(lambda1 - lambda2), $MachinePrecision] * N[Cos[N[(N[(phi1 + phi2), $MachinePrecision] / 2.0), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]}, If[LessEqual[N[(lambda1 - lambda2), $MachinePrecision], -1.1e-12], N[(R * N[(N[(t$95$0 * t$95$0), $MachinePrecision] + N[(N[(phi1 - phi2), $MachinePrecision] * N[(phi1 - phi2), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], If[LessEqual[N[(lambda1 - lambda2), $MachinePrecision], 4e-50], N[(R * N[(phi1 + phi2), $MachinePrecision]), $MachinePrecision], N[(R * N[(lambda1 - lambda2), $MachinePrecision]), $MachinePrecision]]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\\
\mathbf{if}\;\lambda_1 - \lambda_2 \leq -1.1 \cdot 10^{-12}:\\
\;\;\;\;R \cdot \left(t\_0 \cdot t\_0 + \left(\phi_1 - \phi_2\right) \cdot \left(\phi_1 - \phi_2\right)\right)\\

\mathbf{elif}\;\lambda_1 - \lambda_2 \leq 4 \cdot 10^{-50}:\\
\;\;\;\;R \cdot \left(\phi_1 + \phi_2\right)\\

\mathbf{else}:\\
\;\;\;\;R \cdot \left(\lambda_1 - \lambda_2\right)\\


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if (-.f64 lambda1 lambda2) < -1.09999999999999996e-12

    1. Initial program 58.7%

      \[R \cdot \sqrt{\left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) \cdot \left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) + \left(\phi_1 - \phi_2\right) \cdot \left(\phi_1 - \phi_2\right)} \]
    2. Add Preprocessing
    3. Taylor expanded in lambda1 around 0

      \[\leadsto R \cdot \color{blue}{\sqrt{{\lambda_2}^{2} \cdot {\cos \left(\frac{1}{2} \cdot \left(\phi_1 + \phi_2\right)\right)}^{2} + {\left(\phi_1 - \phi_2\right)}^{2}}} \]
    4. Applied rewrites17.2%

      \[\leadsto R \cdot \color{blue}{\left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right)} \]
    5. Taylor expanded in lambda1 around 0

      \[\leadsto R \cdot \left(-1 \cdot \left(\lambda_2 \cdot \cos \left(\frac{1}{2} \cdot \left(\phi_1 + \phi_2\right)\right)\right) + \color{blue}{\lambda_1 \cdot \cos \left(\frac{1}{2} \cdot \left(\phi_1 + \phi_2\right)\right)}\right) \]
    6. Applied rewrites43.7%

      \[\leadsto R \cdot \left(\left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) \cdot \left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) + \color{blue}{\left(\phi_1 - \phi_2\right) \cdot \left(\phi_1 - \phi_2\right)}\right) \]

    if -1.09999999999999996e-12 < (-.f64 lambda1 lambda2) < 4.00000000000000003e-50

    1. Initial program 68.6%

      \[R \cdot \sqrt{\left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) \cdot \left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) + \left(\phi_1 - \phi_2\right) \cdot \left(\phi_1 - \phi_2\right)} \]
    2. Add Preprocessing
    3. Taylor expanded in lambda1 around 0

      \[\leadsto R \cdot \color{blue}{\sqrt{{\lambda_2}^{2} \cdot {\cos \left(\frac{1}{2} \cdot \left(\phi_1 + \phi_2\right)\right)}^{2} + {\left(\phi_1 - \phi_2\right)}^{2}}} \]
    4. Applied rewrites6.6%

      \[\leadsto R \cdot \color{blue}{\left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right)} \]
    5. Taylor expanded in lambda1 around 0

      \[\leadsto R \cdot \color{blue}{\left(\sqrt{{\lambda_2}^{2} \cdot {\cos \left(\frac{1}{2} \cdot \left(\phi_1 + \phi_2\right)\right)}^{2} + {\left(\phi_1 - \phi_2\right)}^{2}} + \lambda_1 \cdot \left(-1 \cdot \left(\left(\lambda_2 \cdot {\cos \left(\frac{1}{2} \cdot \left(\phi_1 + \phi_2\right)\right)}^{2}\right) \cdot \sqrt{\frac{1}{{\lambda_2}^{2} \cdot {\cos \left(\frac{1}{2} \cdot \left(\phi_1 + \phi_2\right)\right)}^{2} + {\left(\phi_1 - \phi_2\right)}^{2}}}\right) + \frac{1}{2} \cdot \left(\left(\lambda_1 \cdot \left({\cos \left(\frac{1}{2} \cdot \left(\phi_1 + \phi_2\right)\right)}^{2} - \frac{{\lambda_2}^{2} \cdot {\cos \left(\frac{1}{2} \cdot \left(\phi_1 + \phi_2\right)\right)}^{4}}{{\lambda_2}^{2} \cdot {\cos \left(\frac{1}{2} \cdot \left(\phi_1 + \phi_2\right)\right)}^{2} + {\left(\phi_1 - \phi_2\right)}^{2}}\right)\right) \cdot \sqrt{\frac{1}{{\lambda_2}^{2} \cdot {\cos \left(\frac{1}{2} \cdot \left(\phi_1 + \phi_2\right)\right)}^{2} + {\left(\phi_1 - \phi_2\right)}^{2}}}\right)\right)\right)} \]
    6. Applied rewrites50.5%

      \[\leadsto R \cdot \color{blue}{\left(\phi_1 + \phi_2\right)} \]

    if 4.00000000000000003e-50 < (-.f64 lambda1 lambda2)

    1. Initial program 57.6%

      \[R \cdot \sqrt{\left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) \cdot \left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) + \left(\phi_1 - \phi_2\right) \cdot \left(\phi_1 - \phi_2\right)} \]
    2. Add Preprocessing
    3. Taylor expanded in lambda1 around 0

      \[\leadsto R \cdot \color{blue}{\sqrt{{\lambda_2}^{2} \cdot {\cos \left(\frac{1}{2} \cdot \left(\phi_1 + \phi_2\right)\right)}^{2} + {\left(\phi_1 - \phi_2\right)}^{2}}} \]
    4. Applied rewrites43.4%

      \[\leadsto R \cdot \color{blue}{\left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right)} \]
    5. Taylor expanded in lambda1 around 0

      \[\leadsto R \cdot \left(-1 \cdot \left(\lambda_2 \cdot \cos \left(\frac{1}{2} \cdot \left(\phi_1 + \phi_2\right)\right)\right) + \color{blue}{\lambda_1 \cdot \cos \left(\frac{1}{2} \cdot \left(\phi_1 + \phi_2\right)\right)}\right) \]
    6. Applied rewrites32.7%

      \[\leadsto R \cdot \left(\left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) \cdot \left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) + \color{blue}{\left(\phi_1 - \phi_2\right) \cdot \left(\phi_1 - \phi_2\right)}\right) \]
    7. Taylor expanded in lambda1 around 0

      \[\leadsto R \cdot \color{blue}{\sqrt{{\lambda_2}^{2} \cdot {\cos \left(\frac{1}{2} \cdot \left(\phi_1 + \phi_2\right)\right)}^{2} + {\left(\phi_1 - \phi_2\right)}^{2}}} \]
    8. Applied rewrites50.9%

      \[\leadsto R \cdot \color{blue}{\left(\lambda_1 - \lambda_2\right)} \]
  3. Recombined 3 regimes into one program.
  4. Add Preprocessing

Alternative 3: 45.4% accurate, 1.1× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\\ \mathbf{if}\;\lambda_1 - \lambda_2 \leq -1.35 \cdot 10^{+124}:\\ \;\;\;\;R \cdot \left(t\_0 \cdot t\_0\right)\\ \mathbf{elif}\;\lambda_1 - \lambda_2 \leq 4 \cdot 10^{-50}:\\ \;\;\;\;R \cdot \left(\phi_1 + \phi_2\right)\\ \mathbf{else}:\\ \;\;\;\;R \cdot \left(\lambda_1 - \lambda_2\right)\\ \end{array} \end{array} \]
(FPCore (R lambda1 lambda2 phi1 phi2)
 :precision binary64
 (let* ((t_0 (* (- lambda1 lambda2) (cos (/ (+ phi1 phi2) 2.0)))))
   (if (<= (- lambda1 lambda2) -1.35e+124)
     (* R (* t_0 t_0))
     (if (<= (- lambda1 lambda2) 4e-50)
       (* R (+ phi1 phi2))
       (* R (- lambda1 lambda2))))))
double code(double R, double lambda1, double lambda2, double phi1, double phi2) {
	double t_0 = (lambda1 - lambda2) * cos(((phi1 + phi2) / 2.0));
	double tmp;
	if ((lambda1 - lambda2) <= -1.35e+124) {
		tmp = R * (t_0 * t_0);
	} else if ((lambda1 - lambda2) <= 4e-50) {
		tmp = R * (phi1 + phi2);
	} else {
		tmp = R * (lambda1 - lambda2);
	}
	return tmp;
}
real(8) function code(r, lambda1, lambda2, phi1, phi2)
    real(8), intent (in) :: r
    real(8), intent (in) :: lambda1
    real(8), intent (in) :: lambda2
    real(8), intent (in) :: phi1
    real(8), intent (in) :: phi2
    real(8) :: t_0
    real(8) :: tmp
    t_0 = (lambda1 - lambda2) * cos(((phi1 + phi2) / 2.0d0))
    if ((lambda1 - lambda2) <= (-1.35d+124)) then
        tmp = r * (t_0 * t_0)
    else if ((lambda1 - lambda2) <= 4d-50) then
        tmp = r * (phi1 + phi2)
    else
        tmp = r * (lambda1 - lambda2)
    end if
    code = tmp
end function
public static double code(double R, double lambda1, double lambda2, double phi1, double phi2) {
	double t_0 = (lambda1 - lambda2) * Math.cos(((phi1 + phi2) / 2.0));
	double tmp;
	if ((lambda1 - lambda2) <= -1.35e+124) {
		tmp = R * (t_0 * t_0);
	} else if ((lambda1 - lambda2) <= 4e-50) {
		tmp = R * (phi1 + phi2);
	} else {
		tmp = R * (lambda1 - lambda2);
	}
	return tmp;
}
def code(R, lambda1, lambda2, phi1, phi2):
	t_0 = (lambda1 - lambda2) * math.cos(((phi1 + phi2) / 2.0))
	tmp = 0
	if (lambda1 - lambda2) <= -1.35e+124:
		tmp = R * (t_0 * t_0)
	elif (lambda1 - lambda2) <= 4e-50:
		tmp = R * (phi1 + phi2)
	else:
		tmp = R * (lambda1 - lambda2)
	return tmp
function code(R, lambda1, lambda2, phi1, phi2)
	t_0 = Float64(Float64(lambda1 - lambda2) * cos(Float64(Float64(phi1 + phi2) / 2.0)))
	tmp = 0.0
	if (Float64(lambda1 - lambda2) <= -1.35e+124)
		tmp = Float64(R * Float64(t_0 * t_0));
	elseif (Float64(lambda1 - lambda2) <= 4e-50)
		tmp = Float64(R * Float64(phi1 + phi2));
	else
		tmp = Float64(R * Float64(lambda1 - lambda2));
	end
	return tmp
end
function tmp_2 = code(R, lambda1, lambda2, phi1, phi2)
	t_0 = (lambda1 - lambda2) * cos(((phi1 + phi2) / 2.0));
	tmp = 0.0;
	if ((lambda1 - lambda2) <= -1.35e+124)
		tmp = R * (t_0 * t_0);
	elseif ((lambda1 - lambda2) <= 4e-50)
		tmp = R * (phi1 + phi2);
	else
		tmp = R * (lambda1 - lambda2);
	end
	tmp_2 = tmp;
end
code[R_, lambda1_, lambda2_, phi1_, phi2_] := Block[{t$95$0 = N[(N[(lambda1 - lambda2), $MachinePrecision] * N[Cos[N[(N[(phi1 + phi2), $MachinePrecision] / 2.0), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]}, If[LessEqual[N[(lambda1 - lambda2), $MachinePrecision], -1.35e+124], N[(R * N[(t$95$0 * t$95$0), $MachinePrecision]), $MachinePrecision], If[LessEqual[N[(lambda1 - lambda2), $MachinePrecision], 4e-50], N[(R * N[(phi1 + phi2), $MachinePrecision]), $MachinePrecision], N[(R * N[(lambda1 - lambda2), $MachinePrecision]), $MachinePrecision]]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\\
\mathbf{if}\;\lambda_1 - \lambda_2 \leq -1.35 \cdot 10^{+124}:\\
\;\;\;\;R \cdot \left(t\_0 \cdot t\_0\right)\\

\mathbf{elif}\;\lambda_1 - \lambda_2 \leq 4 \cdot 10^{-50}:\\
\;\;\;\;R \cdot \left(\phi_1 + \phi_2\right)\\

\mathbf{else}:\\
\;\;\;\;R \cdot \left(\lambda_1 - \lambda_2\right)\\


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if (-.f64 lambda1 lambda2) < -1.34999999999999989e124

    1. Initial program 53.4%

      \[R \cdot \sqrt{\left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) \cdot \left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) + \left(\phi_1 - \phi_2\right) \cdot \left(\phi_1 - \phi_2\right)} \]
    2. Add Preprocessing
    3. Taylor expanded in lambda1 around 0

      \[\leadsto R \cdot \color{blue}{\sqrt{{\lambda_2}^{2} \cdot {\cos \left(\frac{1}{2} \cdot \left(\phi_1 + \phi_2\right)\right)}^{2} + {\left(\phi_1 - \phi_2\right)}^{2}}} \]
    4. Applied rewrites22.2%

      \[\leadsto R \cdot \color{blue}{\left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right)} \]
    5. Taylor expanded in lambda1 around 0

      \[\leadsto R \cdot \left(-1 \cdot \color{blue}{\left(\lambda_2 \cdot \cos \left(\frac{1}{2} \cdot \left(\phi_1 + \phi_2\right)\right)\right)}\right) \]
    6. Applied rewrites47.7%

      \[\leadsto R \cdot \left(\left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) \cdot \color{blue}{\left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right)}\right) \]

    if -1.34999999999999989e124 < (-.f64 lambda1 lambda2) < 4.00000000000000003e-50

    1. Initial program 69.3%

      \[R \cdot \sqrt{\left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) \cdot \left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) + \left(\phi_1 - \phi_2\right) \cdot \left(\phi_1 - \phi_2\right)} \]
    2. Add Preprocessing
    3. Taylor expanded in lambda1 around 0

      \[\leadsto R \cdot \color{blue}{\sqrt{{\lambda_2}^{2} \cdot {\cos \left(\frac{1}{2} \cdot \left(\phi_1 + \phi_2\right)\right)}^{2} + {\left(\phi_1 - \phi_2\right)}^{2}}} \]
    4. Applied rewrites6.5%

      \[\leadsto R \cdot \color{blue}{\left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right)} \]
    5. Taylor expanded in lambda1 around 0

      \[\leadsto R \cdot \color{blue}{\left(\sqrt{{\lambda_2}^{2} \cdot {\cos \left(\frac{1}{2} \cdot \left(\phi_1 + \phi_2\right)\right)}^{2} + {\left(\phi_1 - \phi_2\right)}^{2}} + \lambda_1 \cdot \left(-1 \cdot \left(\left(\lambda_2 \cdot {\cos \left(\frac{1}{2} \cdot \left(\phi_1 + \phi_2\right)\right)}^{2}\right) \cdot \sqrt{\frac{1}{{\lambda_2}^{2} \cdot {\cos \left(\frac{1}{2} \cdot \left(\phi_1 + \phi_2\right)\right)}^{2} + {\left(\phi_1 - \phi_2\right)}^{2}}}\right) + \frac{1}{2} \cdot \left(\left(\lambda_1 \cdot \left({\cos \left(\frac{1}{2} \cdot \left(\phi_1 + \phi_2\right)\right)}^{2} - \frac{{\lambda_2}^{2} \cdot {\cos \left(\frac{1}{2} \cdot \left(\phi_1 + \phi_2\right)\right)}^{4}}{{\lambda_2}^{2} \cdot {\cos \left(\frac{1}{2} \cdot \left(\phi_1 + \phi_2\right)\right)}^{2} + {\left(\phi_1 - \phi_2\right)}^{2}}\right)\right) \cdot \sqrt{\frac{1}{{\lambda_2}^{2} \cdot {\cos \left(\frac{1}{2} \cdot \left(\phi_1 + \phi_2\right)\right)}^{2} + {\left(\phi_1 - \phi_2\right)}^{2}}}\right)\right)\right)} \]
    6. Applied rewrites43.6%

      \[\leadsto R \cdot \color{blue}{\left(\phi_1 + \phi_2\right)} \]

    if 4.00000000000000003e-50 < (-.f64 lambda1 lambda2)

    1. Initial program 57.6%

      \[R \cdot \sqrt{\left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) \cdot \left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) + \left(\phi_1 - \phi_2\right) \cdot \left(\phi_1 - \phi_2\right)} \]
    2. Add Preprocessing
    3. Taylor expanded in lambda1 around 0

      \[\leadsto R \cdot \color{blue}{\sqrt{{\lambda_2}^{2} \cdot {\cos \left(\frac{1}{2} \cdot \left(\phi_1 + \phi_2\right)\right)}^{2} + {\left(\phi_1 - \phi_2\right)}^{2}}} \]
    4. Applied rewrites43.4%

      \[\leadsto R \cdot \color{blue}{\left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right)} \]
    5. Taylor expanded in lambda1 around 0

      \[\leadsto R \cdot \left(-1 \cdot \left(\lambda_2 \cdot \cos \left(\frac{1}{2} \cdot \left(\phi_1 + \phi_2\right)\right)\right) + \color{blue}{\lambda_1 \cdot \cos \left(\frac{1}{2} \cdot \left(\phi_1 + \phi_2\right)\right)}\right) \]
    6. Applied rewrites32.7%

      \[\leadsto R \cdot \left(\left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) \cdot \left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) + \color{blue}{\left(\phi_1 - \phi_2\right) \cdot \left(\phi_1 - \phi_2\right)}\right) \]
    7. Taylor expanded in lambda1 around 0

      \[\leadsto R \cdot \color{blue}{\sqrt{{\lambda_2}^{2} \cdot {\cos \left(\frac{1}{2} \cdot \left(\phi_1 + \phi_2\right)\right)}^{2} + {\left(\phi_1 - \phi_2\right)}^{2}}} \]
    8. Applied rewrites50.9%

      \[\leadsto R \cdot \color{blue}{\left(\lambda_1 - \lambda_2\right)} \]
  3. Recombined 3 regimes into one program.
  4. Add Preprocessing

Alternative 4: 39.5% accurate, 2.0× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \frac{\phi_1 + \phi_2}{2}\\ \mathbf{if}\;\phi_2 \leq -7.5 \cdot 10^{+54}:\\ \;\;\;\;R \cdot \left(R \cdot t\_0\right)\\ \mathbf{elif}\;\phi_2 \leq 3.8 \cdot 10^{-45}:\\ \;\;\;\;R \cdot \left(\left(\lambda_1 - \lambda_2\right) \cdot \cos t\_0\right)\\ \mathbf{else}:\\ \;\;\;\;R \cdot \left(\phi_1 + \phi_2\right)\\ \end{array} \end{array} \]
(FPCore (R lambda1 lambda2 phi1 phi2)
 :precision binary64
 (let* ((t_0 (/ (+ phi1 phi2) 2.0)))
   (if (<= phi2 -7.5e+54)
     (* R (* R t_0))
     (if (<= phi2 3.8e-45)
       (* R (* (- lambda1 lambda2) (cos t_0)))
       (* R (+ phi1 phi2))))))
double code(double R, double lambda1, double lambda2, double phi1, double phi2) {
	double t_0 = (phi1 + phi2) / 2.0;
	double tmp;
	if (phi2 <= -7.5e+54) {
		tmp = R * (R * t_0);
	} else if (phi2 <= 3.8e-45) {
		tmp = R * ((lambda1 - lambda2) * cos(t_0));
	} else {
		tmp = R * (phi1 + phi2);
	}
	return tmp;
}
real(8) function code(r, lambda1, lambda2, phi1, phi2)
    real(8), intent (in) :: r
    real(8), intent (in) :: lambda1
    real(8), intent (in) :: lambda2
    real(8), intent (in) :: phi1
    real(8), intent (in) :: phi2
    real(8) :: t_0
    real(8) :: tmp
    t_0 = (phi1 + phi2) / 2.0d0
    if (phi2 <= (-7.5d+54)) then
        tmp = r * (r * t_0)
    else if (phi2 <= 3.8d-45) then
        tmp = r * ((lambda1 - lambda2) * cos(t_0))
    else
        tmp = r * (phi1 + phi2)
    end if
    code = tmp
end function
public static double code(double R, double lambda1, double lambda2, double phi1, double phi2) {
	double t_0 = (phi1 + phi2) / 2.0;
	double tmp;
	if (phi2 <= -7.5e+54) {
		tmp = R * (R * t_0);
	} else if (phi2 <= 3.8e-45) {
		tmp = R * ((lambda1 - lambda2) * Math.cos(t_0));
	} else {
		tmp = R * (phi1 + phi2);
	}
	return tmp;
}
def code(R, lambda1, lambda2, phi1, phi2):
	t_0 = (phi1 + phi2) / 2.0
	tmp = 0
	if phi2 <= -7.5e+54:
		tmp = R * (R * t_0)
	elif phi2 <= 3.8e-45:
		tmp = R * ((lambda1 - lambda2) * math.cos(t_0))
	else:
		tmp = R * (phi1 + phi2)
	return tmp
function code(R, lambda1, lambda2, phi1, phi2)
	t_0 = Float64(Float64(phi1 + phi2) / 2.0)
	tmp = 0.0
	if (phi2 <= -7.5e+54)
		tmp = Float64(R * Float64(R * t_0));
	elseif (phi2 <= 3.8e-45)
		tmp = Float64(R * Float64(Float64(lambda1 - lambda2) * cos(t_0)));
	else
		tmp = Float64(R * Float64(phi1 + phi2));
	end
	return tmp
end
function tmp_2 = code(R, lambda1, lambda2, phi1, phi2)
	t_0 = (phi1 + phi2) / 2.0;
	tmp = 0.0;
	if (phi2 <= -7.5e+54)
		tmp = R * (R * t_0);
	elseif (phi2 <= 3.8e-45)
		tmp = R * ((lambda1 - lambda2) * cos(t_0));
	else
		tmp = R * (phi1 + phi2);
	end
	tmp_2 = tmp;
end
code[R_, lambda1_, lambda2_, phi1_, phi2_] := Block[{t$95$0 = N[(N[(phi1 + phi2), $MachinePrecision] / 2.0), $MachinePrecision]}, If[LessEqual[phi2, -7.5e+54], N[(R * N[(R * t$95$0), $MachinePrecision]), $MachinePrecision], If[LessEqual[phi2, 3.8e-45], N[(R * N[(N[(lambda1 - lambda2), $MachinePrecision] * N[Cos[t$95$0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(R * N[(phi1 + phi2), $MachinePrecision]), $MachinePrecision]]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \frac{\phi_1 + \phi_2}{2}\\
\mathbf{if}\;\phi_2 \leq -7.5 \cdot 10^{+54}:\\
\;\;\;\;R \cdot \left(R \cdot t\_0\right)\\

\mathbf{elif}\;\phi_2 \leq 3.8 \cdot 10^{-45}:\\
\;\;\;\;R \cdot \left(\left(\lambda_1 - \lambda_2\right) \cdot \cos t\_0\right)\\

\mathbf{else}:\\
\;\;\;\;R \cdot \left(\phi_1 + \phi_2\right)\\


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if phi2 < -7.50000000000000042e54

    1. Initial program 50.7%

      \[R \cdot \sqrt{\left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) \cdot \left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) + \left(\phi_1 - \phi_2\right) \cdot \left(\phi_1 - \phi_2\right)} \]
    2. Add Preprocessing
    3. Taylor expanded in lambda1 around 0

      \[\leadsto R \cdot \color{blue}{\sqrt{{\lambda_2}^{2} \cdot {\cos \left(\frac{1}{2} \cdot \left(\phi_1 + \phi_2\right)\right)}^{2} + {\left(\phi_1 - \phi_2\right)}^{2}}} \]
    4. Applied rewrites13.1%

      \[\leadsto R \cdot \color{blue}{\left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right)} \]
    5. Taylor expanded in lambda1 around 0

      \[\leadsto R \cdot \left(-1 \cdot \left(\lambda_2 \cdot \cos \left(\frac{1}{2} \cdot \left(\phi_1 + \phi_2\right)\right)\right) + \color{blue}{\lambda_1 \cdot \cos \left(\frac{1}{2} \cdot \left(\phi_1 + \phi_2\right)\right)}\right) \]
    6. Applied rewrites39.8%

      \[\leadsto R \cdot \left(\left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) \cdot \left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) + \color{blue}{\left(\phi_1 - \phi_2\right) \cdot \left(\phi_1 - \phi_2\right)}\right) \]
    7. Taylor expanded in lambda1 around 0

      \[\leadsto R \cdot \color{blue}{\left(\sqrt{{\lambda_2}^{2} \cdot {\cos \left(\frac{1}{2} \cdot \left(\phi_1 + \phi_2\right)\right)}^{2} + {\left(\phi_1 - \phi_2\right)}^{2}} + -1 \cdot \left(\left(\lambda_1 \cdot \left(\lambda_2 \cdot {\cos \left(\frac{1}{2} \cdot \left(\phi_1 + \phi_2\right)\right)}^{2}\right)\right) \cdot \sqrt{\frac{1}{{\lambda_2}^{2} \cdot {\cos \left(\frac{1}{2} \cdot \left(\phi_1 + \phi_2\right)\right)}^{2} + {\left(\phi_1 - \phi_2\right)}^{2}}}\right)\right)} \]
    8. Applied rewrites25.2%

      \[\leadsto R \cdot \color{blue}{\left(R \cdot \frac{\phi_1 + \phi_2}{2}\right)} \]

    if -7.50000000000000042e54 < phi2 < 3.79999999999999997e-45

    1. Initial program 68.6%

      \[R \cdot \sqrt{\left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) \cdot \left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) + \left(\phi_1 - \phi_2\right) \cdot \left(\phi_1 - \phi_2\right)} \]
    2. Add Preprocessing
    3. Taylor expanded in lambda1 around 0

      \[\leadsto R \cdot \color{blue}{\sqrt{{\lambda_2}^{2} \cdot {\cos \left(\frac{1}{2} \cdot \left(\phi_1 + \phi_2\right)\right)}^{2} + {\left(\phi_1 - \phi_2\right)}^{2}}} \]
    4. Applied rewrites41.1%

      \[\leadsto R \cdot \color{blue}{\left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right)} \]

    if 3.79999999999999997e-45 < phi2

    1. Initial program 51.0%

      \[R \cdot \sqrt{\left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) \cdot \left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) + \left(\phi_1 - \phi_2\right) \cdot \left(\phi_1 - \phi_2\right)} \]
    2. Add Preprocessing
    3. Taylor expanded in lambda1 around 0

      \[\leadsto R \cdot \color{blue}{\sqrt{{\lambda_2}^{2} \cdot {\cos \left(\frac{1}{2} \cdot \left(\phi_1 + \phi_2\right)\right)}^{2} + {\left(\phi_1 - \phi_2\right)}^{2}}} \]
    4. Applied rewrites11.1%

      \[\leadsto R \cdot \color{blue}{\left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right)} \]
    5. Taylor expanded in lambda1 around 0

      \[\leadsto R \cdot \color{blue}{\left(\sqrt{{\lambda_2}^{2} \cdot {\cos \left(\frac{1}{2} \cdot \left(\phi_1 + \phi_2\right)\right)}^{2} + {\left(\phi_1 - \phi_2\right)}^{2}} + \lambda_1 \cdot \left(-1 \cdot \left(\left(\lambda_2 \cdot {\cos \left(\frac{1}{2} \cdot \left(\phi_1 + \phi_2\right)\right)}^{2}\right) \cdot \sqrt{\frac{1}{{\lambda_2}^{2} \cdot {\cos \left(\frac{1}{2} \cdot \left(\phi_1 + \phi_2\right)\right)}^{2} + {\left(\phi_1 - \phi_2\right)}^{2}}}\right) + \frac{1}{2} \cdot \left(\left(\lambda_1 \cdot \left({\cos \left(\frac{1}{2} \cdot \left(\phi_1 + \phi_2\right)\right)}^{2} - \frac{{\lambda_2}^{2} \cdot {\cos \left(\frac{1}{2} \cdot \left(\phi_1 + \phi_2\right)\right)}^{4}}{{\lambda_2}^{2} \cdot {\cos \left(\frac{1}{2} \cdot \left(\phi_1 + \phi_2\right)\right)}^{2} + {\left(\phi_1 - \phi_2\right)}^{2}}\right)\right) \cdot \sqrt{\frac{1}{{\lambda_2}^{2} \cdot {\cos \left(\frac{1}{2} \cdot \left(\phi_1 + \phi_2\right)\right)}^{2} + {\left(\phi_1 - \phi_2\right)}^{2}}}\right)\right)\right)} \]
    6. Applied rewrites58.4%

      \[\leadsto R \cdot \color{blue}{\left(\phi_1 + \phi_2\right)} \]
  3. Recombined 3 regimes into one program.
  4. Add Preprocessing

Alternative 5: 39.7% accurate, 8.2× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;\lambda_1 - \lambda_2 \leq -3.8 \cdot 10^{+154}:\\ \;\;\;\;R \cdot \left(R \cdot \frac{\phi_1 + \phi_2}{2}\right)\\ \mathbf{elif}\;\lambda_1 - \lambda_2 \leq 4 \cdot 10^{-50}:\\ \;\;\;\;R \cdot \left(\phi_1 + \phi_2\right)\\ \mathbf{else}:\\ \;\;\;\;R \cdot \left(\lambda_1 - \lambda_2\right)\\ \end{array} \end{array} \]
(FPCore (R lambda1 lambda2 phi1 phi2)
 :precision binary64
 (if (<= (- lambda1 lambda2) -3.8e+154)
   (* R (* R (/ (+ phi1 phi2) 2.0)))
   (if (<= (- lambda1 lambda2) 4e-50)
     (* R (+ phi1 phi2))
     (* R (- lambda1 lambda2)))))
double code(double R, double lambda1, double lambda2, double phi1, double phi2) {
	double tmp;
	if ((lambda1 - lambda2) <= -3.8e+154) {
		tmp = R * (R * ((phi1 + phi2) / 2.0));
	} else if ((lambda1 - lambda2) <= 4e-50) {
		tmp = R * (phi1 + phi2);
	} else {
		tmp = R * (lambda1 - lambda2);
	}
	return tmp;
}
real(8) function code(r, lambda1, lambda2, phi1, phi2)
    real(8), intent (in) :: r
    real(8), intent (in) :: lambda1
    real(8), intent (in) :: lambda2
    real(8), intent (in) :: phi1
    real(8), intent (in) :: phi2
    real(8) :: tmp
    if ((lambda1 - lambda2) <= (-3.8d+154)) then
        tmp = r * (r * ((phi1 + phi2) / 2.0d0))
    else if ((lambda1 - lambda2) <= 4d-50) then
        tmp = r * (phi1 + phi2)
    else
        tmp = r * (lambda1 - lambda2)
    end if
    code = tmp
end function
public static double code(double R, double lambda1, double lambda2, double phi1, double phi2) {
	double tmp;
	if ((lambda1 - lambda2) <= -3.8e+154) {
		tmp = R * (R * ((phi1 + phi2) / 2.0));
	} else if ((lambda1 - lambda2) <= 4e-50) {
		tmp = R * (phi1 + phi2);
	} else {
		tmp = R * (lambda1 - lambda2);
	}
	return tmp;
}
def code(R, lambda1, lambda2, phi1, phi2):
	tmp = 0
	if (lambda1 - lambda2) <= -3.8e+154:
		tmp = R * (R * ((phi1 + phi2) / 2.0))
	elif (lambda1 - lambda2) <= 4e-50:
		tmp = R * (phi1 + phi2)
	else:
		tmp = R * (lambda1 - lambda2)
	return tmp
function code(R, lambda1, lambda2, phi1, phi2)
	tmp = 0.0
	if (Float64(lambda1 - lambda2) <= -3.8e+154)
		tmp = Float64(R * Float64(R * Float64(Float64(phi1 + phi2) / 2.0)));
	elseif (Float64(lambda1 - lambda2) <= 4e-50)
		tmp = Float64(R * Float64(phi1 + phi2));
	else
		tmp = Float64(R * Float64(lambda1 - lambda2));
	end
	return tmp
end
function tmp_2 = code(R, lambda1, lambda2, phi1, phi2)
	tmp = 0.0;
	if ((lambda1 - lambda2) <= -3.8e+154)
		tmp = R * (R * ((phi1 + phi2) / 2.0));
	elseif ((lambda1 - lambda2) <= 4e-50)
		tmp = R * (phi1 + phi2);
	else
		tmp = R * (lambda1 - lambda2);
	end
	tmp_2 = tmp;
end
code[R_, lambda1_, lambda2_, phi1_, phi2_] := If[LessEqual[N[(lambda1 - lambda2), $MachinePrecision], -3.8e+154], N[(R * N[(R * N[(N[(phi1 + phi2), $MachinePrecision] / 2.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], If[LessEqual[N[(lambda1 - lambda2), $MachinePrecision], 4e-50], N[(R * N[(phi1 + phi2), $MachinePrecision]), $MachinePrecision], N[(R * N[(lambda1 - lambda2), $MachinePrecision]), $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;\lambda_1 - \lambda_2 \leq -3.8 \cdot 10^{+154}:\\
\;\;\;\;R \cdot \left(R \cdot \frac{\phi_1 + \phi_2}{2}\right)\\

\mathbf{elif}\;\lambda_1 - \lambda_2 \leq 4 \cdot 10^{-50}:\\
\;\;\;\;R \cdot \left(\phi_1 + \phi_2\right)\\

\mathbf{else}:\\
\;\;\;\;R \cdot \left(\lambda_1 - \lambda_2\right)\\


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if (-.f64 lambda1 lambda2) < -3.7999999999999998e154

    1. Initial program 48.9%

      \[R \cdot \sqrt{\left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) \cdot \left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) + \left(\phi_1 - \phi_2\right) \cdot \left(\phi_1 - \phi_2\right)} \]
    2. Add Preprocessing
    3. Taylor expanded in lambda1 around 0

      \[\leadsto R \cdot \color{blue}{\sqrt{{\lambda_2}^{2} \cdot {\cos \left(\frac{1}{2} \cdot \left(\phi_1 + \phi_2\right)\right)}^{2} + {\left(\phi_1 - \phi_2\right)}^{2}}} \]
    4. Applied rewrites19.7%

      \[\leadsto R \cdot \color{blue}{\left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right)} \]
    5. Taylor expanded in lambda1 around 0

      \[\leadsto R \cdot \left(-1 \cdot \left(\lambda_2 \cdot \cos \left(\frac{1}{2} \cdot \left(\phi_1 + \phi_2\right)\right)\right) + \color{blue}{\lambda_1 \cdot \cos \left(\frac{1}{2} \cdot \left(\phi_1 + \phi_2\right)\right)}\right) \]
    6. Applied rewrites48.9%

      \[\leadsto R \cdot \left(\left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) \cdot \left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) + \color{blue}{\left(\phi_1 - \phi_2\right) \cdot \left(\phi_1 - \phi_2\right)}\right) \]
    7. Taylor expanded in lambda1 around 0

      \[\leadsto R \cdot \color{blue}{\left(\sqrt{{\lambda_2}^{2} \cdot {\cos \left(\frac{1}{2} \cdot \left(\phi_1 + \phi_2\right)\right)}^{2} + {\left(\phi_1 - \phi_2\right)}^{2}} + -1 \cdot \left(\left(\lambda_1 \cdot \left(\lambda_2 \cdot {\cos \left(\frac{1}{2} \cdot \left(\phi_1 + \phi_2\right)\right)}^{2}\right)\right) \cdot \sqrt{\frac{1}{{\lambda_2}^{2} \cdot {\cos \left(\frac{1}{2} \cdot \left(\phi_1 + \phi_2\right)\right)}^{2} + {\left(\phi_1 - \phi_2\right)}^{2}}}\right)\right)} \]
    8. Applied rewrites28.2%

      \[\leadsto R \cdot \color{blue}{\left(R \cdot \frac{\phi_1 + \phi_2}{2}\right)} \]

    if -3.7999999999999998e154 < (-.f64 lambda1 lambda2) < 4.00000000000000003e-50

    1. Initial program 69.5%

      \[R \cdot \sqrt{\left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) \cdot \left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) + \left(\phi_1 - \phi_2\right) \cdot \left(\phi_1 - \phi_2\right)} \]
    2. Add Preprocessing
    3. Taylor expanded in lambda1 around 0

      \[\leadsto R \cdot \color{blue}{\sqrt{{\lambda_2}^{2} \cdot {\cos \left(\frac{1}{2} \cdot \left(\phi_1 + \phi_2\right)\right)}^{2} + {\left(\phi_1 - \phi_2\right)}^{2}}} \]
    4. Applied rewrites10.2%

      \[\leadsto R \cdot \color{blue}{\left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right)} \]
    5. Taylor expanded in lambda1 around 0

      \[\leadsto R \cdot \color{blue}{\left(\sqrt{{\lambda_2}^{2} \cdot {\cos \left(\frac{1}{2} \cdot \left(\phi_1 + \phi_2\right)\right)}^{2} + {\left(\phi_1 - \phi_2\right)}^{2}} + \lambda_1 \cdot \left(-1 \cdot \left(\left(\lambda_2 \cdot {\cos \left(\frac{1}{2} \cdot \left(\phi_1 + \phi_2\right)\right)}^{2}\right) \cdot \sqrt{\frac{1}{{\lambda_2}^{2} \cdot {\cos \left(\frac{1}{2} \cdot \left(\phi_1 + \phi_2\right)\right)}^{2} + {\left(\phi_1 - \phi_2\right)}^{2}}}\right) + \frac{1}{2} \cdot \left(\left(\lambda_1 \cdot \left({\cos \left(\frac{1}{2} \cdot \left(\phi_1 + \phi_2\right)\right)}^{2} - \frac{{\lambda_2}^{2} \cdot {\cos \left(\frac{1}{2} \cdot \left(\phi_1 + \phi_2\right)\right)}^{4}}{{\lambda_2}^{2} \cdot {\cos \left(\frac{1}{2} \cdot \left(\phi_1 + \phi_2\right)\right)}^{2} + {\left(\phi_1 - \phi_2\right)}^{2}}\right)\right) \cdot \sqrt{\frac{1}{{\lambda_2}^{2} \cdot {\cos \left(\frac{1}{2} \cdot \left(\phi_1 + \phi_2\right)\right)}^{2} + {\left(\phi_1 - \phi_2\right)}^{2}}}\right)\right)\right)} \]
    6. Applied rewrites39.7%

      \[\leadsto R \cdot \color{blue}{\left(\phi_1 + \phi_2\right)} \]

    if 4.00000000000000003e-50 < (-.f64 lambda1 lambda2)

    1. Initial program 57.6%

      \[R \cdot \sqrt{\left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) \cdot \left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) + \left(\phi_1 - \phi_2\right) \cdot \left(\phi_1 - \phi_2\right)} \]
    2. Add Preprocessing
    3. Taylor expanded in lambda1 around 0

      \[\leadsto R \cdot \color{blue}{\sqrt{{\lambda_2}^{2} \cdot {\cos \left(\frac{1}{2} \cdot \left(\phi_1 + \phi_2\right)\right)}^{2} + {\left(\phi_1 - \phi_2\right)}^{2}}} \]
    4. Applied rewrites43.4%

      \[\leadsto R \cdot \color{blue}{\left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right)} \]
    5. Taylor expanded in lambda1 around 0

      \[\leadsto R \cdot \left(-1 \cdot \left(\lambda_2 \cdot \cos \left(\frac{1}{2} \cdot \left(\phi_1 + \phi_2\right)\right)\right) + \color{blue}{\lambda_1 \cdot \cos \left(\frac{1}{2} \cdot \left(\phi_1 + \phi_2\right)\right)}\right) \]
    6. Applied rewrites32.7%

      \[\leadsto R \cdot \left(\left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) \cdot \left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) + \color{blue}{\left(\phi_1 - \phi_2\right) \cdot \left(\phi_1 - \phi_2\right)}\right) \]
    7. Taylor expanded in lambda1 around 0

      \[\leadsto R \cdot \color{blue}{\sqrt{{\lambda_2}^{2} \cdot {\cos \left(\frac{1}{2} \cdot \left(\phi_1 + \phi_2\right)\right)}^{2} + {\left(\phi_1 - \phi_2\right)}^{2}}} \]
    8. Applied rewrites50.9%

      \[\leadsto R \cdot \color{blue}{\left(\lambda_1 - \lambda_2\right)} \]
  3. Recombined 3 regimes into one program.
  4. Add Preprocessing

Alternative 6: 41.1% accurate, 10.3× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := R \cdot \left(\lambda_1 - \lambda_2\right)\\ \mathbf{if}\;\lambda_1 - \lambda_2 \leq -7.2 \cdot 10^{+192}:\\ \;\;\;\;R \cdot t\_0\\ \mathbf{elif}\;\lambda_1 - \lambda_2 \leq 4 \cdot 10^{-50}:\\ \;\;\;\;R \cdot \left(\phi_1 + \phi_2\right)\\ \mathbf{else}:\\ \;\;\;\;t\_0\\ \end{array} \end{array} \]
(FPCore (R lambda1 lambda2 phi1 phi2)
 :precision binary64
 (let* ((t_0 (* R (- lambda1 lambda2))))
   (if (<= (- lambda1 lambda2) -7.2e+192)
     (* R t_0)
     (if (<= (- lambda1 lambda2) 4e-50) (* R (+ phi1 phi2)) t_0))))
double code(double R, double lambda1, double lambda2, double phi1, double phi2) {
	double t_0 = R * (lambda1 - lambda2);
	double tmp;
	if ((lambda1 - lambda2) <= -7.2e+192) {
		tmp = R * t_0;
	} else if ((lambda1 - lambda2) <= 4e-50) {
		tmp = R * (phi1 + phi2);
	} else {
		tmp = t_0;
	}
	return tmp;
}
real(8) function code(r, lambda1, lambda2, phi1, phi2)
    real(8), intent (in) :: r
    real(8), intent (in) :: lambda1
    real(8), intent (in) :: lambda2
    real(8), intent (in) :: phi1
    real(8), intent (in) :: phi2
    real(8) :: t_0
    real(8) :: tmp
    t_0 = r * (lambda1 - lambda2)
    if ((lambda1 - lambda2) <= (-7.2d+192)) then
        tmp = r * t_0
    else if ((lambda1 - lambda2) <= 4d-50) then
        tmp = r * (phi1 + phi2)
    else
        tmp = t_0
    end if
    code = tmp
end function
public static double code(double R, double lambda1, double lambda2, double phi1, double phi2) {
	double t_0 = R * (lambda1 - lambda2);
	double tmp;
	if ((lambda1 - lambda2) <= -7.2e+192) {
		tmp = R * t_0;
	} else if ((lambda1 - lambda2) <= 4e-50) {
		tmp = R * (phi1 + phi2);
	} else {
		tmp = t_0;
	}
	return tmp;
}
def code(R, lambda1, lambda2, phi1, phi2):
	t_0 = R * (lambda1 - lambda2)
	tmp = 0
	if (lambda1 - lambda2) <= -7.2e+192:
		tmp = R * t_0
	elif (lambda1 - lambda2) <= 4e-50:
		tmp = R * (phi1 + phi2)
	else:
		tmp = t_0
	return tmp
function code(R, lambda1, lambda2, phi1, phi2)
	t_0 = Float64(R * Float64(lambda1 - lambda2))
	tmp = 0.0
	if (Float64(lambda1 - lambda2) <= -7.2e+192)
		tmp = Float64(R * t_0);
	elseif (Float64(lambda1 - lambda2) <= 4e-50)
		tmp = Float64(R * Float64(phi1 + phi2));
	else
		tmp = t_0;
	end
	return tmp
end
function tmp_2 = code(R, lambda1, lambda2, phi1, phi2)
	t_0 = R * (lambda1 - lambda2);
	tmp = 0.0;
	if ((lambda1 - lambda2) <= -7.2e+192)
		tmp = R * t_0;
	elseif ((lambda1 - lambda2) <= 4e-50)
		tmp = R * (phi1 + phi2);
	else
		tmp = t_0;
	end
	tmp_2 = tmp;
end
code[R_, lambda1_, lambda2_, phi1_, phi2_] := Block[{t$95$0 = N[(R * N[(lambda1 - lambda2), $MachinePrecision]), $MachinePrecision]}, If[LessEqual[N[(lambda1 - lambda2), $MachinePrecision], -7.2e+192], N[(R * t$95$0), $MachinePrecision], If[LessEqual[N[(lambda1 - lambda2), $MachinePrecision], 4e-50], N[(R * N[(phi1 + phi2), $MachinePrecision]), $MachinePrecision], t$95$0]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := R \cdot \left(\lambda_1 - \lambda_2\right)\\
\mathbf{if}\;\lambda_1 - \lambda_2 \leq -7.2 \cdot 10^{+192}:\\
\;\;\;\;R \cdot t\_0\\

\mathbf{elif}\;\lambda_1 - \lambda_2 \leq 4 \cdot 10^{-50}:\\
\;\;\;\;R \cdot \left(\phi_1 + \phi_2\right)\\

\mathbf{else}:\\
\;\;\;\;t\_0\\


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if (-.f64 lambda1 lambda2) < -7.2000000000000004e192

    1. Initial program 43.6%

      \[R \cdot \sqrt{\left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) \cdot \left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) + \left(\phi_1 - \phi_2\right) \cdot \left(\phi_1 - \phi_2\right)} \]
    2. Add Preprocessing
    3. Taylor expanded in lambda1 around 0

      \[\leadsto R \cdot \color{blue}{\sqrt{{\lambda_2}^{2} \cdot {\cos \left(\frac{1}{2} \cdot \left(\phi_1 + \phi_2\right)\right)}^{2} + {\left(\phi_1 - \phi_2\right)}^{2}}} \]
    4. Applied rewrites20.9%

      \[\leadsto R \cdot \color{blue}{\left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right)} \]
    5. Taylor expanded in lambda1 around 0

      \[\leadsto R \cdot \left(-1 \cdot \color{blue}{\left(\lambda_2 \cdot \cos \left(\frac{1}{2} \cdot \left(\phi_1 + \phi_2\right)\right)\right)}\right) \]
    6. Applied rewrites43.6%

      \[\leadsto R \cdot \left(\left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) \cdot \color{blue}{\left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right)}\right) \]
    7. Taylor expanded in lambda1 around 0

      \[\leadsto R \cdot \color{blue}{\left(\sqrt{{\lambda_2}^{2} \cdot {\cos \left(\frac{1}{2} \cdot \left(\phi_1 + \phi_2\right)\right)}^{2} + {\left(\phi_1 - \phi_2\right)}^{2}} + \lambda_1 \cdot \left(-1 \cdot \left(\left(\lambda_2 \cdot {\cos \left(\frac{1}{2} \cdot \left(\phi_1 + \phi_2\right)\right)}^{2}\right) \cdot \sqrt{\frac{1}{{\lambda_2}^{2} \cdot {\cos \left(\frac{1}{2} \cdot \left(\phi_1 + \phi_2\right)\right)}^{2} + {\left(\phi_1 - \phi_2\right)}^{2}}}\right) + \frac{1}{2} \cdot \left(\left(\lambda_1 \cdot \left({\cos \left(\frac{1}{2} \cdot \left(\phi_1 + \phi_2\right)\right)}^{2} - \frac{{\lambda_2}^{2} \cdot {\cos \left(\frac{1}{2} \cdot \left(\phi_1 + \phi_2\right)\right)}^{4}}{{\lambda_2}^{2} \cdot {\cos \left(\frac{1}{2} \cdot \left(\phi_1 + \phi_2\right)\right)}^{2} + {\left(\phi_1 - \phi_2\right)}^{2}}\right)\right) \cdot \sqrt{\frac{1}{{\lambda_2}^{2} \cdot {\cos \left(\frac{1}{2} \cdot \left(\phi_1 + \phi_2\right)\right)}^{2} + {\left(\phi_1 - \phi_2\right)}^{2}}}\right)\right)\right)} \]
    8. Applied rewrites26.1%

      \[\leadsto R \cdot \color{blue}{\left(R \cdot \left(\lambda_1 - \lambda_2\right)\right)} \]

    if -7.2000000000000004e192 < (-.f64 lambda1 lambda2) < 4.00000000000000003e-50

    1. Initial program 70.1%

      \[R \cdot \sqrt{\left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) \cdot \left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) + \left(\phi_1 - \phi_2\right) \cdot \left(\phi_1 - \phi_2\right)} \]
    2. Add Preprocessing
    3. Taylor expanded in lambda1 around 0

      \[\leadsto R \cdot \color{blue}{\sqrt{{\lambda_2}^{2} \cdot {\cos \left(\frac{1}{2} \cdot \left(\phi_1 + \phi_2\right)\right)}^{2} + {\left(\phi_1 - \phi_2\right)}^{2}}} \]
    4. Applied rewrites10.5%

      \[\leadsto R \cdot \color{blue}{\left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right)} \]
    5. Taylor expanded in lambda1 around 0

      \[\leadsto R \cdot \color{blue}{\left(\sqrt{{\lambda_2}^{2} \cdot {\cos \left(\frac{1}{2} \cdot \left(\phi_1 + \phi_2\right)\right)}^{2} + {\left(\phi_1 - \phi_2\right)}^{2}} + \lambda_1 \cdot \left(-1 \cdot \left(\left(\lambda_2 \cdot {\cos \left(\frac{1}{2} \cdot \left(\phi_1 + \phi_2\right)\right)}^{2}\right) \cdot \sqrt{\frac{1}{{\lambda_2}^{2} \cdot {\cos \left(\frac{1}{2} \cdot \left(\phi_1 + \phi_2\right)\right)}^{2} + {\left(\phi_1 - \phi_2\right)}^{2}}}\right) + \frac{1}{2} \cdot \left(\left(\lambda_1 \cdot \left({\cos \left(\frac{1}{2} \cdot \left(\phi_1 + \phi_2\right)\right)}^{2} - \frac{{\lambda_2}^{2} \cdot {\cos \left(\frac{1}{2} \cdot \left(\phi_1 + \phi_2\right)\right)}^{4}}{{\lambda_2}^{2} \cdot {\cos \left(\frac{1}{2} \cdot \left(\phi_1 + \phi_2\right)\right)}^{2} + {\left(\phi_1 - \phi_2\right)}^{2}}\right)\right) \cdot \sqrt{\frac{1}{{\lambda_2}^{2} \cdot {\cos \left(\frac{1}{2} \cdot \left(\phi_1 + \phi_2\right)\right)}^{2} + {\left(\phi_1 - \phi_2\right)}^{2}}}\right)\right)\right)} \]
    6. Applied rewrites39.7%

      \[\leadsto R \cdot \color{blue}{\left(\phi_1 + \phi_2\right)} \]

    if 4.00000000000000003e-50 < (-.f64 lambda1 lambda2)

    1. Initial program 57.6%

      \[R \cdot \sqrt{\left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) \cdot \left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) + \left(\phi_1 - \phi_2\right) \cdot \left(\phi_1 - \phi_2\right)} \]
    2. Add Preprocessing
    3. Taylor expanded in lambda1 around 0

      \[\leadsto R \cdot \color{blue}{\sqrt{{\lambda_2}^{2} \cdot {\cos \left(\frac{1}{2} \cdot \left(\phi_1 + \phi_2\right)\right)}^{2} + {\left(\phi_1 - \phi_2\right)}^{2}}} \]
    4. Applied rewrites43.4%

      \[\leadsto R \cdot \color{blue}{\left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right)} \]
    5. Taylor expanded in lambda1 around 0

      \[\leadsto R \cdot \left(-1 \cdot \left(\lambda_2 \cdot \cos \left(\frac{1}{2} \cdot \left(\phi_1 + \phi_2\right)\right)\right) + \color{blue}{\lambda_1 \cdot \cos \left(\frac{1}{2} \cdot \left(\phi_1 + \phi_2\right)\right)}\right) \]
    6. Applied rewrites32.7%

      \[\leadsto R \cdot \left(\left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) \cdot \left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) + \color{blue}{\left(\phi_1 - \phi_2\right) \cdot \left(\phi_1 - \phi_2\right)}\right) \]
    7. Taylor expanded in lambda1 around 0

      \[\leadsto R \cdot \color{blue}{\sqrt{{\lambda_2}^{2} \cdot {\cos \left(\frac{1}{2} \cdot \left(\phi_1 + \phi_2\right)\right)}^{2} + {\left(\phi_1 - \phi_2\right)}^{2}}} \]
    8. Applied rewrites50.9%

      \[\leadsto R \cdot \color{blue}{\left(\lambda_1 - \lambda_2\right)} \]
  3. Recombined 3 regimes into one program.
  4. Add Preprocessing

Alternative 7: 39.7% accurate, 15.5× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;\lambda_1 - \lambda_2 \leq 4 \cdot 10^{-50}:\\ \;\;\;\;R \cdot \left(\phi_1 + \phi_2\right)\\ \mathbf{else}:\\ \;\;\;\;R \cdot \left(\lambda_1 - \lambda_2\right)\\ \end{array} \end{array} \]
(FPCore (R lambda1 lambda2 phi1 phi2)
 :precision binary64
 (if (<= (- lambda1 lambda2) 4e-50)
   (* R (+ phi1 phi2))
   (* R (- lambda1 lambda2))))
double code(double R, double lambda1, double lambda2, double phi1, double phi2) {
	double tmp;
	if ((lambda1 - lambda2) <= 4e-50) {
		tmp = R * (phi1 + phi2);
	} else {
		tmp = R * (lambda1 - lambda2);
	}
	return tmp;
}
real(8) function code(r, lambda1, lambda2, phi1, phi2)
    real(8), intent (in) :: r
    real(8), intent (in) :: lambda1
    real(8), intent (in) :: lambda2
    real(8), intent (in) :: phi1
    real(8), intent (in) :: phi2
    real(8) :: tmp
    if ((lambda1 - lambda2) <= 4d-50) then
        tmp = r * (phi1 + phi2)
    else
        tmp = r * (lambda1 - lambda2)
    end if
    code = tmp
end function
public static double code(double R, double lambda1, double lambda2, double phi1, double phi2) {
	double tmp;
	if ((lambda1 - lambda2) <= 4e-50) {
		tmp = R * (phi1 + phi2);
	} else {
		tmp = R * (lambda1 - lambda2);
	}
	return tmp;
}
def code(R, lambda1, lambda2, phi1, phi2):
	tmp = 0
	if (lambda1 - lambda2) <= 4e-50:
		tmp = R * (phi1 + phi2)
	else:
		tmp = R * (lambda1 - lambda2)
	return tmp
function code(R, lambda1, lambda2, phi1, phi2)
	tmp = 0.0
	if (Float64(lambda1 - lambda2) <= 4e-50)
		tmp = Float64(R * Float64(phi1 + phi2));
	else
		tmp = Float64(R * Float64(lambda1 - lambda2));
	end
	return tmp
end
function tmp_2 = code(R, lambda1, lambda2, phi1, phi2)
	tmp = 0.0;
	if ((lambda1 - lambda2) <= 4e-50)
		tmp = R * (phi1 + phi2);
	else
		tmp = R * (lambda1 - lambda2);
	end
	tmp_2 = tmp;
end
code[R_, lambda1_, lambda2_, phi1_, phi2_] := If[LessEqual[N[(lambda1 - lambda2), $MachinePrecision], 4e-50], N[(R * N[(phi1 + phi2), $MachinePrecision]), $MachinePrecision], N[(R * N[(lambda1 - lambda2), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;\lambda_1 - \lambda_2 \leq 4 \cdot 10^{-50}:\\
\;\;\;\;R \cdot \left(\phi_1 + \phi_2\right)\\

\mathbf{else}:\\
\;\;\;\;R \cdot \left(\lambda_1 - \lambda_2\right)\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (-.f64 lambda1 lambda2) < 4.00000000000000003e-50

    1. Initial program 62.1%

      \[R \cdot \sqrt{\left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) \cdot \left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) + \left(\phi_1 - \phi_2\right) \cdot \left(\phi_1 - \phi_2\right)} \]
    2. Add Preprocessing
    3. Taylor expanded in lambda1 around 0

      \[\leadsto R \cdot \color{blue}{\sqrt{{\lambda_2}^{2} \cdot {\cos \left(\frac{1}{2} \cdot \left(\phi_1 + \phi_2\right)\right)}^{2} + {\left(\phi_1 - \phi_2\right)}^{2}}} \]
    4. Applied rewrites13.6%

      \[\leadsto R \cdot \color{blue}{\left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right)} \]
    5. Taylor expanded in lambda1 around 0

      \[\leadsto R \cdot \color{blue}{\left(\sqrt{{\lambda_2}^{2} \cdot {\cos \left(\frac{1}{2} \cdot \left(\phi_1 + \phi_2\right)\right)}^{2} + {\left(\phi_1 - \phi_2\right)}^{2}} + \lambda_1 \cdot \left(-1 \cdot \left(\left(\lambda_2 \cdot {\cos \left(\frac{1}{2} \cdot \left(\phi_1 + \phi_2\right)\right)}^{2}\right) \cdot \sqrt{\frac{1}{{\lambda_2}^{2} \cdot {\cos \left(\frac{1}{2} \cdot \left(\phi_1 + \phi_2\right)\right)}^{2} + {\left(\phi_1 - \phi_2\right)}^{2}}}\right) + \frac{1}{2} \cdot \left(\left(\lambda_1 \cdot \left({\cos \left(\frac{1}{2} \cdot \left(\phi_1 + \phi_2\right)\right)}^{2} - \frac{{\lambda_2}^{2} \cdot {\cos \left(\frac{1}{2} \cdot \left(\phi_1 + \phi_2\right)\right)}^{4}}{{\lambda_2}^{2} \cdot {\cos \left(\frac{1}{2} \cdot \left(\phi_1 + \phi_2\right)\right)}^{2} + {\left(\phi_1 - \phi_2\right)}^{2}}\right)\right) \cdot \sqrt{\frac{1}{{\lambda_2}^{2} \cdot {\cos \left(\frac{1}{2} \cdot \left(\phi_1 + \phi_2\right)\right)}^{2} + {\left(\phi_1 - \phi_2\right)}^{2}}}\right)\right)\right)} \]
    6. Applied rewrites30.7%

      \[\leadsto R \cdot \color{blue}{\left(\phi_1 + \phi_2\right)} \]

    if 4.00000000000000003e-50 < (-.f64 lambda1 lambda2)

    1. Initial program 57.6%

      \[R \cdot \sqrt{\left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) \cdot \left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) + \left(\phi_1 - \phi_2\right) \cdot \left(\phi_1 - \phi_2\right)} \]
    2. Add Preprocessing
    3. Taylor expanded in lambda1 around 0

      \[\leadsto R \cdot \color{blue}{\sqrt{{\lambda_2}^{2} \cdot {\cos \left(\frac{1}{2} \cdot \left(\phi_1 + \phi_2\right)\right)}^{2} + {\left(\phi_1 - \phi_2\right)}^{2}}} \]
    4. Applied rewrites43.4%

      \[\leadsto R \cdot \color{blue}{\left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right)} \]
    5. Taylor expanded in lambda1 around 0

      \[\leadsto R \cdot \left(-1 \cdot \left(\lambda_2 \cdot \cos \left(\frac{1}{2} \cdot \left(\phi_1 + \phi_2\right)\right)\right) + \color{blue}{\lambda_1 \cdot \cos \left(\frac{1}{2} \cdot \left(\phi_1 + \phi_2\right)\right)}\right) \]
    6. Applied rewrites32.7%

      \[\leadsto R \cdot \left(\left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) \cdot \left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) + \color{blue}{\left(\phi_1 - \phi_2\right) \cdot \left(\phi_1 - \phi_2\right)}\right) \]
    7. Taylor expanded in lambda1 around 0

      \[\leadsto R \cdot \color{blue}{\sqrt{{\lambda_2}^{2} \cdot {\cos \left(\frac{1}{2} \cdot \left(\phi_1 + \phi_2\right)\right)}^{2} + {\left(\phi_1 - \phi_2\right)}^{2}}} \]
    8. Applied rewrites50.9%

      \[\leadsto R \cdot \color{blue}{\left(\lambda_1 - \lambda_2\right)} \]
  3. Recombined 2 regimes into one program.
  4. Add Preprocessing

Alternative 8: 29.8% accurate, 31.0× speedup?

\[\begin{array}{l} \\ R \cdot \left(\phi_1 + \phi_2\right) \end{array} \]
(FPCore (R lambda1 lambda2 phi1 phi2) :precision binary64 (* R (+ phi1 phi2)))
double code(double R, double lambda1, double lambda2, double phi1, double phi2) {
	return R * (phi1 + phi2);
}
real(8) function code(r, lambda1, lambda2, phi1, phi2)
    real(8), intent (in) :: r
    real(8), intent (in) :: lambda1
    real(8), intent (in) :: lambda2
    real(8), intent (in) :: phi1
    real(8), intent (in) :: phi2
    code = r * (phi1 + phi2)
end function
public static double code(double R, double lambda1, double lambda2, double phi1, double phi2) {
	return R * (phi1 + phi2);
}
def code(R, lambda1, lambda2, phi1, phi2):
	return R * (phi1 + phi2)
function code(R, lambda1, lambda2, phi1, phi2)
	return Float64(R * Float64(phi1 + phi2))
end
function tmp = code(R, lambda1, lambda2, phi1, phi2)
	tmp = R * (phi1 + phi2);
end
code[R_, lambda1_, lambda2_, phi1_, phi2_] := N[(R * N[(phi1 + phi2), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
R \cdot \left(\phi_1 + \phi_2\right)
\end{array}
Derivation
  1. Initial program 60.1%

    \[R \cdot \sqrt{\left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) \cdot \left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) + \left(\phi_1 - \phi_2\right) \cdot \left(\phi_1 - \phi_2\right)} \]
  2. Add Preprocessing
  3. Taylor expanded in lambda1 around 0

    \[\leadsto R \cdot \color{blue}{\sqrt{{\lambda_2}^{2} \cdot {\cos \left(\frac{1}{2} \cdot \left(\phi_1 + \phi_2\right)\right)}^{2} + {\left(\phi_1 - \phi_2\right)}^{2}}} \]
  4. Applied rewrites27.1%

    \[\leadsto R \cdot \color{blue}{\left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right)} \]
  5. Taylor expanded in lambda1 around 0

    \[\leadsto R \cdot \color{blue}{\left(\sqrt{{\lambda_2}^{2} \cdot {\cos \left(\frac{1}{2} \cdot \left(\phi_1 + \phi_2\right)\right)}^{2} + {\left(\phi_1 - \phi_2\right)}^{2}} + \lambda_1 \cdot \left(-1 \cdot \left(\left(\lambda_2 \cdot {\cos \left(\frac{1}{2} \cdot \left(\phi_1 + \phi_2\right)\right)}^{2}\right) \cdot \sqrt{\frac{1}{{\lambda_2}^{2} \cdot {\cos \left(\frac{1}{2} \cdot \left(\phi_1 + \phi_2\right)\right)}^{2} + {\left(\phi_1 - \phi_2\right)}^{2}}}\right) + \frac{1}{2} \cdot \left(\left(\lambda_1 \cdot \left({\cos \left(\frac{1}{2} \cdot \left(\phi_1 + \phi_2\right)\right)}^{2} - \frac{{\lambda_2}^{2} \cdot {\cos \left(\frac{1}{2} \cdot \left(\phi_1 + \phi_2\right)\right)}^{4}}{{\lambda_2}^{2} \cdot {\cos \left(\frac{1}{2} \cdot \left(\phi_1 + \phi_2\right)\right)}^{2} + {\left(\phi_1 - \phi_2\right)}^{2}}\right)\right) \cdot \sqrt{\frac{1}{{\lambda_2}^{2} \cdot {\cos \left(\frac{1}{2} \cdot \left(\phi_1 + \phi_2\right)\right)}^{2} + {\left(\phi_1 - \phi_2\right)}^{2}}}\right)\right)\right)} \]
  6. Applied rewrites28.0%

    \[\leadsto R \cdot \color{blue}{\left(\phi_1 + \phi_2\right)} \]
  7. Add Preprocessing

Alternative 9: 3.3% accurate, 69.8× speedup?

\[\begin{array}{l} \\ \lambda_1 - \lambda_2 \end{array} \]
(FPCore (R lambda1 lambda2 phi1 phi2) :precision binary64 (- lambda1 lambda2))
double code(double R, double lambda1, double lambda2, double phi1, double phi2) {
	return lambda1 - lambda2;
}
real(8) function code(r, lambda1, lambda2, phi1, phi2)
    real(8), intent (in) :: r
    real(8), intent (in) :: lambda1
    real(8), intent (in) :: lambda2
    real(8), intent (in) :: phi1
    real(8), intent (in) :: phi2
    code = lambda1 - lambda2
end function
public static double code(double R, double lambda1, double lambda2, double phi1, double phi2) {
	return lambda1 - lambda2;
}
def code(R, lambda1, lambda2, phi1, phi2):
	return lambda1 - lambda2
function code(R, lambda1, lambda2, phi1, phi2)
	return Float64(lambda1 - lambda2)
end
function tmp = code(R, lambda1, lambda2, phi1, phi2)
	tmp = lambda1 - lambda2;
end
code[R_, lambda1_, lambda2_, phi1_, phi2_] := N[(lambda1 - lambda2), $MachinePrecision]
\begin{array}{l}

\\
\lambda_1 - \lambda_2
\end{array}
Derivation
  1. Initial program 60.1%

    \[R \cdot \sqrt{\left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) \cdot \left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) + \left(\phi_1 - \phi_2\right) \cdot \left(\phi_1 - \phi_2\right)} \]
  2. Add Preprocessing
  3. Taylor expanded in lambda1 around 0

    \[\leadsto R \cdot \color{blue}{\sqrt{{\lambda_2}^{2} \cdot {\cos \left(\frac{1}{2} \cdot \left(\phi_1 + \phi_2\right)\right)}^{2} + {\left(\phi_1 - \phi_2\right)}^{2}}} \]
  4. Applied rewrites27.1%

    \[\leadsto R \cdot \color{blue}{\left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right)} \]
  5. Taylor expanded in lambda1 around 0

    \[\leadsto \color{blue}{R \cdot \sqrt{{\lambda_2}^{2} \cdot {\cos \left(\frac{1}{2} \cdot \left(\phi_1 + \phi_2\right)\right)}^{2} + {\left(\phi_1 - \phi_2\right)}^{2}} + \lambda_1 \cdot \left(-1 \cdot \left(\left(R \cdot \left(\lambda_2 \cdot {\cos \left(\frac{1}{2} \cdot \left(\phi_1 + \phi_2\right)\right)}^{2}\right)\right) \cdot \sqrt{\frac{1}{{\lambda_2}^{2} \cdot {\cos \left(\frac{1}{2} \cdot \left(\phi_1 + \phi_2\right)\right)}^{2} + {\left(\phi_1 - \phi_2\right)}^{2}}}\right) + \frac{1}{2} \cdot \left(\left(R \cdot \left(\lambda_1 \cdot \left({\cos \left(\frac{1}{2} \cdot \left(\phi_1 + \phi_2\right)\right)}^{2} - \frac{{\lambda_2}^{2} \cdot {\cos \left(\frac{1}{2} \cdot \left(\phi_1 + \phi_2\right)\right)}^{4}}{{\lambda_2}^{2} \cdot {\cos \left(\frac{1}{2} \cdot \left(\phi_1 + \phi_2\right)\right)}^{2} + {\left(\phi_1 - \phi_2\right)}^{2}}\right)\right)\right) \cdot \sqrt{\frac{1}{{\lambda_2}^{2} \cdot {\cos \left(\frac{1}{2} \cdot \left(\phi_1 + \phi_2\right)\right)}^{2} + {\left(\phi_1 - \phi_2\right)}^{2}}}\right)\right)} \]
  6. Applied rewrites3.3%

    \[\leadsto \color{blue}{\lambda_1 - \lambda_2} \]
  7. Add Preprocessing

Reproduce

?
herbie shell --seed 2024321 
(FPCore (R lambda1 lambda2 phi1 phi2)
  :name "Equirectangular approximation to distance on a great circle"
  :precision binary64
  :pre (TRUE)
  (* R (sqrt (+ (* (* (- lambda1 lambda2) (cos (/ (+ phi1 phi2) 2.0))) (* (- lambda1 lambda2) (cos (/ (+ phi1 phi2) 2.0)))) (* (- phi1 phi2) (- phi1 phi2))))))