Toniolo and Linder, Equation (10-)

Percentage Accurate: 35.9% → 96.5%
Time: 17.8s
Alternatives: 21
Speedup: 11.0×

Specification

?
\[\begin{array}{l} \\ \frac{2}{\left(\left(\frac{{t}^{3}}{\ell \cdot \ell} \cdot \sin k\right) \cdot \tan k\right) \cdot \left(\left(1 + {\left(\frac{k}{t}\right)}^{2}\right) - 1\right)} \end{array} \]
(FPCore (t l k)
 :precision binary64
 (/
  2.0
  (*
   (* (* (/ (pow t 3.0) (* l l)) (sin k)) (tan k))
   (- (+ 1.0 (pow (/ k t) 2.0)) 1.0))))
double code(double t, double l, double k) {
	return 2.0 / ((((pow(t, 3.0) / (l * l)) * sin(k)) * tan(k)) * ((1.0 + pow((k / t), 2.0)) - 1.0));
}
real(8) function code(t, l, k)
    real(8), intent (in) :: t
    real(8), intent (in) :: l
    real(8), intent (in) :: k
    code = 2.0d0 / (((((t ** 3.0d0) / (l * l)) * sin(k)) * tan(k)) * ((1.0d0 + ((k / t) ** 2.0d0)) - 1.0d0))
end function
public static double code(double t, double l, double k) {
	return 2.0 / ((((Math.pow(t, 3.0) / (l * l)) * Math.sin(k)) * Math.tan(k)) * ((1.0 + Math.pow((k / t), 2.0)) - 1.0));
}
def code(t, l, k):
	return 2.0 / ((((math.pow(t, 3.0) / (l * l)) * math.sin(k)) * math.tan(k)) * ((1.0 + math.pow((k / t), 2.0)) - 1.0))
function code(t, l, k)
	return Float64(2.0 / Float64(Float64(Float64(Float64((t ^ 3.0) / Float64(l * l)) * sin(k)) * tan(k)) * Float64(Float64(1.0 + (Float64(k / t) ^ 2.0)) - 1.0)))
end
function tmp = code(t, l, k)
	tmp = 2.0 / (((((t ^ 3.0) / (l * l)) * sin(k)) * tan(k)) * ((1.0 + ((k / t) ^ 2.0)) - 1.0));
end
code[t_, l_, k_] := N[(2.0 / N[(N[(N[(N[(N[Power[t, 3.0], $MachinePrecision] / N[(l * l), $MachinePrecision]), $MachinePrecision] * N[Sin[k], $MachinePrecision]), $MachinePrecision] * N[Tan[k], $MachinePrecision]), $MachinePrecision] * N[(N[(1.0 + N[Power[N[(k / t), $MachinePrecision], 2.0], $MachinePrecision]), $MachinePrecision] - 1.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{2}{\left(\left(\frac{{t}^{3}}{\ell \cdot \ell} \cdot \sin k\right) \cdot \tan k\right) \cdot \left(\left(1 + {\left(\frac{k}{t}\right)}^{2}\right) - 1\right)}
\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 21 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: 35.9% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \frac{2}{\left(\left(\frac{{t}^{3}}{\ell \cdot \ell} \cdot \sin k\right) \cdot \tan k\right) \cdot \left(\left(1 + {\left(\frac{k}{t}\right)}^{2}\right) - 1\right)} \end{array} \]
(FPCore (t l k)
 :precision binary64
 (/
  2.0
  (*
   (* (* (/ (pow t 3.0) (* l l)) (sin k)) (tan k))
   (- (+ 1.0 (pow (/ k t) 2.0)) 1.0))))
double code(double t, double l, double k) {
	return 2.0 / ((((pow(t, 3.0) / (l * l)) * sin(k)) * tan(k)) * ((1.0 + pow((k / t), 2.0)) - 1.0));
}
real(8) function code(t, l, k)
    real(8), intent (in) :: t
    real(8), intent (in) :: l
    real(8), intent (in) :: k
    code = 2.0d0 / (((((t ** 3.0d0) / (l * l)) * sin(k)) * tan(k)) * ((1.0d0 + ((k / t) ** 2.0d0)) - 1.0d0))
end function
public static double code(double t, double l, double k) {
	return 2.0 / ((((Math.pow(t, 3.0) / (l * l)) * Math.sin(k)) * Math.tan(k)) * ((1.0 + Math.pow((k / t), 2.0)) - 1.0));
}
def code(t, l, k):
	return 2.0 / ((((math.pow(t, 3.0) / (l * l)) * math.sin(k)) * math.tan(k)) * ((1.0 + math.pow((k / t), 2.0)) - 1.0))
function code(t, l, k)
	return Float64(2.0 / Float64(Float64(Float64(Float64((t ^ 3.0) / Float64(l * l)) * sin(k)) * tan(k)) * Float64(Float64(1.0 + (Float64(k / t) ^ 2.0)) - 1.0)))
end
function tmp = code(t, l, k)
	tmp = 2.0 / (((((t ^ 3.0) / (l * l)) * sin(k)) * tan(k)) * ((1.0 + ((k / t) ^ 2.0)) - 1.0));
end
code[t_, l_, k_] := N[(2.0 / N[(N[(N[(N[(N[Power[t, 3.0], $MachinePrecision] / N[(l * l), $MachinePrecision]), $MachinePrecision] * N[Sin[k], $MachinePrecision]), $MachinePrecision] * N[Tan[k], $MachinePrecision]), $MachinePrecision] * N[(N[(1.0 + N[Power[N[(k / t), $MachinePrecision], 2.0], $MachinePrecision]), $MachinePrecision] - 1.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{2}{\left(\left(\frac{{t}^{3}}{\ell \cdot \ell} \cdot \sin k\right) \cdot \tan k\right) \cdot \left(\left(1 + {\left(\frac{k}{t}\right)}^{2}\right) - 1\right)}
\end{array}

Alternative 1: 96.5% accurate, 1.7× speedup?

\[\begin{array}{l} t\_m = \left|t\right| \\ t\_s = \mathsf{copysign}\left(1, t\right) \\ \begin{array}{l} t_2 := \frac{2 \cdot \ell}{\sin k \cdot \tan k}\\ t\_s \cdot \begin{array}{l} \mathbf{if}\;t\_m \leq 5:\\ \;\;\;\;t\_2 \cdot \left(\frac{1}{t\_m \cdot k} \cdot \frac{\ell}{k}\right)\\ \mathbf{else}:\\ \;\;\;\;\frac{\frac{t\_2}{t\_m}}{k \cdot \frac{k}{\ell}}\\ \end{array} \end{array} \end{array} \]
t\_m = (fabs.f64 t)
t\_s = (copysign.f64 #s(literal 1 binary64) t)
(FPCore (t_s t_m l k)
 :precision binary64
 (let* ((t_2 (/ (* 2.0 l) (* (sin k) (tan k)))))
   (*
    t_s
    (if (<= t_m 5.0)
      (* t_2 (* (/ 1.0 (* t_m k)) (/ l k)))
      (/ (/ t_2 t_m) (* k (/ k l)))))))
t\_m = fabs(t);
t\_s = copysign(1.0, t);
double code(double t_s, double t_m, double l, double k) {
	double t_2 = (2.0 * l) / (sin(k) * tan(k));
	double tmp;
	if (t_m <= 5.0) {
		tmp = t_2 * ((1.0 / (t_m * k)) * (l / k));
	} else {
		tmp = (t_2 / t_m) / (k * (k / l));
	}
	return t_s * tmp;
}
t\_m = abs(t)
t\_s = copysign(1.0d0, t)
real(8) function code(t_s, t_m, l, k)
    real(8), intent (in) :: t_s
    real(8), intent (in) :: t_m
    real(8), intent (in) :: l
    real(8), intent (in) :: k
    real(8) :: t_2
    real(8) :: tmp
    t_2 = (2.0d0 * l) / (sin(k) * tan(k))
    if (t_m <= 5.0d0) then
        tmp = t_2 * ((1.0d0 / (t_m * k)) * (l / k))
    else
        tmp = (t_2 / t_m) / (k * (k / l))
    end if
    code = t_s * tmp
end function
t\_m = Math.abs(t);
t\_s = Math.copySign(1.0, t);
public static double code(double t_s, double t_m, double l, double k) {
	double t_2 = (2.0 * l) / (Math.sin(k) * Math.tan(k));
	double tmp;
	if (t_m <= 5.0) {
		tmp = t_2 * ((1.0 / (t_m * k)) * (l / k));
	} else {
		tmp = (t_2 / t_m) / (k * (k / l));
	}
	return t_s * tmp;
}
t\_m = math.fabs(t)
t\_s = math.copysign(1.0, t)
def code(t_s, t_m, l, k):
	t_2 = (2.0 * l) / (math.sin(k) * math.tan(k))
	tmp = 0
	if t_m <= 5.0:
		tmp = t_2 * ((1.0 / (t_m * k)) * (l / k))
	else:
		tmp = (t_2 / t_m) / (k * (k / l))
	return t_s * tmp
t\_m = abs(t)
t\_s = copysign(1.0, t)
function code(t_s, t_m, l, k)
	t_2 = Float64(Float64(2.0 * l) / Float64(sin(k) * tan(k)))
	tmp = 0.0
	if (t_m <= 5.0)
		tmp = Float64(t_2 * Float64(Float64(1.0 / Float64(t_m * k)) * Float64(l / k)));
	else
		tmp = Float64(Float64(t_2 / t_m) / Float64(k * Float64(k / l)));
	end
	return Float64(t_s * tmp)
end
t\_m = abs(t);
t\_s = sign(t) * abs(1.0);
function tmp_2 = code(t_s, t_m, l, k)
	t_2 = (2.0 * l) / (sin(k) * tan(k));
	tmp = 0.0;
	if (t_m <= 5.0)
		tmp = t_2 * ((1.0 / (t_m * k)) * (l / k));
	else
		tmp = (t_2 / t_m) / (k * (k / l));
	end
	tmp_2 = t_s * tmp;
end
t\_m = N[Abs[t], $MachinePrecision]
t\_s = N[With[{TMP1 = Abs[1.0], TMP2 = Sign[t]}, TMP1 * If[TMP2 == 0, 1, TMP2]], $MachinePrecision]
code[t$95$s_, t$95$m_, l_, k_] := Block[{t$95$2 = N[(N[(2.0 * l), $MachinePrecision] / N[(N[Sin[k], $MachinePrecision] * N[Tan[k], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]}, N[(t$95$s * If[LessEqual[t$95$m, 5.0], N[(t$95$2 * N[(N[(1.0 / N[(t$95$m * k), $MachinePrecision]), $MachinePrecision] * N[(l / k), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(N[(t$95$2 / t$95$m), $MachinePrecision] / N[(k * N[(k / l), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]), $MachinePrecision]]
\begin{array}{l}
t\_m = \left|t\right|
\\
t\_s = \mathsf{copysign}\left(1, t\right)

\\
\begin{array}{l}
t_2 := \frac{2 \cdot \ell}{\sin k \cdot \tan k}\\
t\_s \cdot \begin{array}{l}
\mathbf{if}\;t\_m \leq 5:\\
\;\;\;\;t\_2 \cdot \left(\frac{1}{t\_m \cdot k} \cdot \frac{\ell}{k}\right)\\

\mathbf{else}:\\
\;\;\;\;\frac{\frac{t\_2}{t\_m}}{k \cdot \frac{k}{\ell}}\\


\end{array}
\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if t < 5

    1. Initial program 42.9%

      \[\frac{2}{\left(\left(\frac{{t}^{3}}{\ell \cdot \ell} \cdot \sin k\right) \cdot \tan k\right) \cdot \left(\left(1 + {\left(\frac{k}{t}\right)}^{2}\right) - 1\right)} \]
    2. Add Preprocessing
    3. Taylor expanded in t around 0

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

        \[\leadsto \color{blue}{\frac{2 \cdot \left({\ell}^{2} \cdot \cos k\right)}{{k}^{2} \cdot \left(t \cdot {\sin k}^{2}\right)}} \]
      2. lower-/.f64N/A

        \[\leadsto \color{blue}{\frac{2 \cdot \left({\ell}^{2} \cdot \cos k\right)}{{k}^{2} \cdot \left(t \cdot {\sin k}^{2}\right)}} \]
      3. lower-*.f64N/A

        \[\leadsto \frac{\color{blue}{2 \cdot \left({\ell}^{2} \cdot \cos k\right)}}{{k}^{2} \cdot \left(t \cdot {\sin k}^{2}\right)} \]
      4. unpow2N/A

        \[\leadsto \frac{2 \cdot \left(\color{blue}{\left(\ell \cdot \ell\right)} \cdot \cos k\right)}{{k}^{2} \cdot \left(t \cdot {\sin k}^{2}\right)} \]
      5. associate-*l*N/A

        \[\leadsto \frac{2 \cdot \color{blue}{\left(\ell \cdot \left(\ell \cdot \cos k\right)\right)}}{{k}^{2} \cdot \left(t \cdot {\sin k}^{2}\right)} \]
      6. *-commutativeN/A

        \[\leadsto \frac{2 \cdot \left(\ell \cdot \color{blue}{\left(\cos k \cdot \ell\right)}\right)}{{k}^{2} \cdot \left(t \cdot {\sin k}^{2}\right)} \]
      7. lower-*.f64N/A

        \[\leadsto \frac{2 \cdot \color{blue}{\left(\ell \cdot \left(\cos k \cdot \ell\right)\right)}}{{k}^{2} \cdot \left(t \cdot {\sin k}^{2}\right)} \]
      8. *-commutativeN/A

        \[\leadsto \frac{2 \cdot \left(\ell \cdot \color{blue}{\left(\ell \cdot \cos k\right)}\right)}{{k}^{2} \cdot \left(t \cdot {\sin k}^{2}\right)} \]
      9. lower-*.f64N/A

        \[\leadsto \frac{2 \cdot \left(\ell \cdot \color{blue}{\left(\ell \cdot \cos k\right)}\right)}{{k}^{2} \cdot \left(t \cdot {\sin k}^{2}\right)} \]
      10. lower-cos.f64N/A

        \[\leadsto \frac{2 \cdot \left(\ell \cdot \left(\ell \cdot \color{blue}{\cos k}\right)\right)}{{k}^{2} \cdot \left(t \cdot {\sin k}^{2}\right)} \]
      11. associate-*r*N/A

        \[\leadsto \frac{2 \cdot \left(\ell \cdot \left(\ell \cdot \cos k\right)\right)}{\color{blue}{\left({k}^{2} \cdot t\right) \cdot {\sin k}^{2}}} \]
      12. *-commutativeN/A

        \[\leadsto \frac{2 \cdot \left(\ell \cdot \left(\ell \cdot \cos k\right)\right)}{\color{blue}{{\sin k}^{2} \cdot \left({k}^{2} \cdot t\right)}} \]
      13. lower-*.f64N/A

        \[\leadsto \frac{2 \cdot \left(\ell \cdot \left(\ell \cdot \cos k\right)\right)}{\color{blue}{{\sin k}^{2} \cdot \left({k}^{2} \cdot t\right)}} \]
      14. lower-pow.f64N/A

        \[\leadsto \frac{2 \cdot \left(\ell \cdot \left(\ell \cdot \cos k\right)\right)}{\color{blue}{{\sin k}^{2}} \cdot \left({k}^{2} \cdot t\right)} \]
      15. lower-sin.f64N/A

        \[\leadsto \frac{2 \cdot \left(\ell \cdot \left(\ell \cdot \cos k\right)\right)}{{\color{blue}{\sin k}}^{2} \cdot \left({k}^{2} \cdot t\right)} \]
      16. *-commutativeN/A

        \[\leadsto \frac{2 \cdot \left(\ell \cdot \left(\ell \cdot \cos k\right)\right)}{{\sin k}^{2} \cdot \color{blue}{\left(t \cdot {k}^{2}\right)}} \]
      17. lower-*.f64N/A

        \[\leadsto \frac{2 \cdot \left(\ell \cdot \left(\ell \cdot \cos k\right)\right)}{{\sin k}^{2} \cdot \color{blue}{\left(t \cdot {k}^{2}\right)}} \]
      18. unpow2N/A

        \[\leadsto \frac{2 \cdot \left(\ell \cdot \left(\ell \cdot \cos k\right)\right)}{{\sin k}^{2} \cdot \left(t \cdot \color{blue}{\left(k \cdot k\right)}\right)} \]
      19. lower-*.f6472.5

        \[\leadsto \frac{2 \cdot \left(\ell \cdot \left(\ell \cdot \cos k\right)\right)}{{\sin k}^{2} \cdot \left(t \cdot \color{blue}{\left(k \cdot k\right)}\right)} \]
    5. Applied rewrites72.5%

      \[\leadsto \color{blue}{\frac{2 \cdot \left(\ell \cdot \left(\ell \cdot \cos k\right)\right)}{{\sin k}^{2} \cdot \left(t \cdot \left(k \cdot k\right)\right)}} \]
    6. Step-by-step derivation
      1. Applied rewrites75.1%

        \[\leadsto \frac{2 \cdot \ell}{t \cdot \left(0.5 - 0.5 \cdot \cos \left(k + k\right)\right)} \cdot \color{blue}{\frac{\ell \cdot \cos k}{k \cdot k}} \]
      2. Step-by-step derivation
        1. Applied rewrites89.9%

          \[\leadsto \frac{\ell}{k} \cdot \color{blue}{\frac{\frac{\ell \cdot \left(2 \cdot \cos k\right)}{\mathsf{fma}\left(\cos \left(k + k\right), -0.5, 0.5\right)}}{t \cdot k}} \]
        2. Step-by-step derivation
          1. Applied rewrites99.0%

            \[\leadsto \frac{\ell \cdot 2}{\sin k \cdot \tan k} \cdot \color{blue}{\left(\frac{1}{k \cdot t} \cdot \frac{\ell}{k}\right)} \]

          if 5 < t

          1. Initial program 23.3%

            \[\frac{2}{\left(\left(\frac{{t}^{3}}{\ell \cdot \ell} \cdot \sin k\right) \cdot \tan k\right) \cdot \left(\left(1 + {\left(\frac{k}{t}\right)}^{2}\right) - 1\right)} \]
          2. Add Preprocessing
          3. Taylor expanded in t around 0

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

              \[\leadsto \color{blue}{\frac{2 \cdot \left({\ell}^{2} \cdot \cos k\right)}{{k}^{2} \cdot \left(t \cdot {\sin k}^{2}\right)}} \]
            2. lower-/.f64N/A

              \[\leadsto \color{blue}{\frac{2 \cdot \left({\ell}^{2} \cdot \cos k\right)}{{k}^{2} \cdot \left(t \cdot {\sin k}^{2}\right)}} \]
            3. lower-*.f64N/A

              \[\leadsto \frac{\color{blue}{2 \cdot \left({\ell}^{2} \cdot \cos k\right)}}{{k}^{2} \cdot \left(t \cdot {\sin k}^{2}\right)} \]
            4. unpow2N/A

              \[\leadsto \frac{2 \cdot \left(\color{blue}{\left(\ell \cdot \ell\right)} \cdot \cos k\right)}{{k}^{2} \cdot \left(t \cdot {\sin k}^{2}\right)} \]
            5. associate-*l*N/A

              \[\leadsto \frac{2 \cdot \color{blue}{\left(\ell \cdot \left(\ell \cdot \cos k\right)\right)}}{{k}^{2} \cdot \left(t \cdot {\sin k}^{2}\right)} \]
            6. *-commutativeN/A

              \[\leadsto \frac{2 \cdot \left(\ell \cdot \color{blue}{\left(\cos k \cdot \ell\right)}\right)}{{k}^{2} \cdot \left(t \cdot {\sin k}^{2}\right)} \]
            7. lower-*.f64N/A

              \[\leadsto \frac{2 \cdot \color{blue}{\left(\ell \cdot \left(\cos k \cdot \ell\right)\right)}}{{k}^{2} \cdot \left(t \cdot {\sin k}^{2}\right)} \]
            8. *-commutativeN/A

              \[\leadsto \frac{2 \cdot \left(\ell \cdot \color{blue}{\left(\ell \cdot \cos k\right)}\right)}{{k}^{2} \cdot \left(t \cdot {\sin k}^{2}\right)} \]
            9. lower-*.f64N/A

              \[\leadsto \frac{2 \cdot \left(\ell \cdot \color{blue}{\left(\ell \cdot \cos k\right)}\right)}{{k}^{2} \cdot \left(t \cdot {\sin k}^{2}\right)} \]
            10. lower-cos.f64N/A

              \[\leadsto \frac{2 \cdot \left(\ell \cdot \left(\ell \cdot \color{blue}{\cos k}\right)\right)}{{k}^{2} \cdot \left(t \cdot {\sin k}^{2}\right)} \]
            11. associate-*r*N/A

              \[\leadsto \frac{2 \cdot \left(\ell \cdot \left(\ell \cdot \cos k\right)\right)}{\color{blue}{\left({k}^{2} \cdot t\right) \cdot {\sin k}^{2}}} \]
            12. *-commutativeN/A

              \[\leadsto \frac{2 \cdot \left(\ell \cdot \left(\ell \cdot \cos k\right)\right)}{\color{blue}{{\sin k}^{2} \cdot \left({k}^{2} \cdot t\right)}} \]
            13. lower-*.f64N/A

              \[\leadsto \frac{2 \cdot \left(\ell \cdot \left(\ell \cdot \cos k\right)\right)}{\color{blue}{{\sin k}^{2} \cdot \left({k}^{2} \cdot t\right)}} \]
            14. lower-pow.f64N/A

              \[\leadsto \frac{2 \cdot \left(\ell \cdot \left(\ell \cdot \cos k\right)\right)}{\color{blue}{{\sin k}^{2}} \cdot \left({k}^{2} \cdot t\right)} \]
            15. lower-sin.f64N/A

              \[\leadsto \frac{2 \cdot \left(\ell \cdot \left(\ell \cdot \cos k\right)\right)}{{\color{blue}{\sin k}}^{2} \cdot \left({k}^{2} \cdot t\right)} \]
            16. *-commutativeN/A

              \[\leadsto \frac{2 \cdot \left(\ell \cdot \left(\ell \cdot \cos k\right)\right)}{{\sin k}^{2} \cdot \color{blue}{\left(t \cdot {k}^{2}\right)}} \]
            17. lower-*.f64N/A

              \[\leadsto \frac{2 \cdot \left(\ell \cdot \left(\ell \cdot \cos k\right)\right)}{{\sin k}^{2} \cdot \color{blue}{\left(t \cdot {k}^{2}\right)}} \]
            18. unpow2N/A

              \[\leadsto \frac{2 \cdot \left(\ell \cdot \left(\ell \cdot \cos k\right)\right)}{{\sin k}^{2} \cdot \left(t \cdot \color{blue}{\left(k \cdot k\right)}\right)} \]
            19. lower-*.f6471.0

              \[\leadsto \frac{2 \cdot \left(\ell \cdot \left(\ell \cdot \cos k\right)\right)}{{\sin k}^{2} \cdot \left(t \cdot \color{blue}{\left(k \cdot k\right)}\right)} \]
          5. Applied rewrites71.0%

            \[\leadsto \color{blue}{\frac{2 \cdot \left(\ell \cdot \left(\ell \cdot \cos k\right)\right)}{{\sin k}^{2} \cdot \left(t \cdot \left(k \cdot k\right)\right)}} \]
          6. Step-by-step derivation
            1. Applied rewrites79.5%

              \[\leadsto \frac{2 \cdot \ell}{t \cdot \left(0.5 - 0.5 \cdot \cos \left(k + k\right)\right)} \cdot \color{blue}{\frac{\ell \cdot \cos k}{k \cdot k}} \]
            2. Step-by-step derivation
              1. Applied rewrites78.7%

                \[\leadsto \frac{\ell}{k} \cdot \color{blue}{\frac{\frac{\ell \cdot \left(2 \cdot \cos k\right)}{\mathsf{fma}\left(\cos \left(k + k\right), -0.5, 0.5\right)}}{t \cdot k}} \]
              2. Applied rewrites96.0%

                \[\leadsto \frac{\frac{\frac{\ell \cdot 2}{\sin k \cdot \tan k}}{t}}{\color{blue}{\frac{k}{\ell} \cdot k}} \]
            3. Recombined 2 regimes into one program.
            4. Final simplification97.5%

              \[\leadsto \begin{array}{l} \mathbf{if}\;t \leq 5:\\ \;\;\;\;\frac{2 \cdot \ell}{\sin k \cdot \tan k} \cdot \left(\frac{1}{t \cdot k} \cdot \frac{\ell}{k}\right)\\ \mathbf{else}:\\ \;\;\;\;\frac{\frac{\frac{2 \cdot \ell}{\sin k \cdot \tan k}}{t}}{k \cdot \frac{k}{\ell}}\\ \end{array} \]
            5. Add Preprocessing

            Alternative 2: 84.5% accurate, 1.8× speedup?

            \[\begin{array}{l} t\_m = \left|t\right| \\ t\_s = \mathsf{copysign}\left(1, t\right) \\ t\_s \cdot \begin{array}{l} \mathbf{if}\;k \leq 3.6 \cdot 10^{-59}:\\ \;\;\;\;\frac{\frac{2 \cdot \frac{\frac{\ell}{k}}{\frac{k}{\ell}}}{t\_m \cdot k}}{k}\\ \mathbf{else}:\\ \;\;\;\;\frac{\ell}{k} \cdot \left(\ell \cdot \frac{\frac{2}{\sin k \cdot \tan k}}{t\_m \cdot k}\right)\\ \end{array} \end{array} \]
            t\_m = (fabs.f64 t)
            t\_s = (copysign.f64 #s(literal 1 binary64) t)
            (FPCore (t_s t_m l k)
             :precision binary64
             (*
              t_s
              (if (<= k 3.6e-59)
                (/ (/ (* 2.0 (/ (/ l k) (/ k l))) (* t_m k)) k)
                (* (/ l k) (* l (/ (/ 2.0 (* (sin k) (tan k))) (* t_m k)))))))
            t\_m = fabs(t);
            t\_s = copysign(1.0, t);
            double code(double t_s, double t_m, double l, double k) {
            	double tmp;
            	if (k <= 3.6e-59) {
            		tmp = ((2.0 * ((l / k) / (k / l))) / (t_m * k)) / k;
            	} else {
            		tmp = (l / k) * (l * ((2.0 / (sin(k) * tan(k))) / (t_m * k)));
            	}
            	return t_s * tmp;
            }
            
            t\_m = abs(t)
            t\_s = copysign(1.0d0, t)
            real(8) function code(t_s, t_m, l, k)
                real(8), intent (in) :: t_s
                real(8), intent (in) :: t_m
                real(8), intent (in) :: l
                real(8), intent (in) :: k
                real(8) :: tmp
                if (k <= 3.6d-59) then
                    tmp = ((2.0d0 * ((l / k) / (k / l))) / (t_m * k)) / k
                else
                    tmp = (l / k) * (l * ((2.0d0 / (sin(k) * tan(k))) / (t_m * k)))
                end if
                code = t_s * tmp
            end function
            
            t\_m = Math.abs(t);
            t\_s = Math.copySign(1.0, t);
            public static double code(double t_s, double t_m, double l, double k) {
            	double tmp;
            	if (k <= 3.6e-59) {
            		tmp = ((2.0 * ((l / k) / (k / l))) / (t_m * k)) / k;
            	} else {
            		tmp = (l / k) * (l * ((2.0 / (Math.sin(k) * Math.tan(k))) / (t_m * k)));
            	}
            	return t_s * tmp;
            }
            
            t\_m = math.fabs(t)
            t\_s = math.copysign(1.0, t)
            def code(t_s, t_m, l, k):
            	tmp = 0
            	if k <= 3.6e-59:
            		tmp = ((2.0 * ((l / k) / (k / l))) / (t_m * k)) / k
            	else:
            		tmp = (l / k) * (l * ((2.0 / (math.sin(k) * math.tan(k))) / (t_m * k)))
            	return t_s * tmp
            
            t\_m = abs(t)
            t\_s = copysign(1.0, t)
            function code(t_s, t_m, l, k)
            	tmp = 0.0
            	if (k <= 3.6e-59)
            		tmp = Float64(Float64(Float64(2.0 * Float64(Float64(l / k) / Float64(k / l))) / Float64(t_m * k)) / k);
            	else
            		tmp = Float64(Float64(l / k) * Float64(l * Float64(Float64(2.0 / Float64(sin(k) * tan(k))) / Float64(t_m * k))));
            	end
            	return Float64(t_s * tmp)
            end
            
            t\_m = abs(t);
            t\_s = sign(t) * abs(1.0);
            function tmp_2 = code(t_s, t_m, l, k)
            	tmp = 0.0;
            	if (k <= 3.6e-59)
            		tmp = ((2.0 * ((l / k) / (k / l))) / (t_m * k)) / k;
            	else
            		tmp = (l / k) * (l * ((2.0 / (sin(k) * tan(k))) / (t_m * k)));
            	end
            	tmp_2 = t_s * tmp;
            end
            
            t\_m = N[Abs[t], $MachinePrecision]
            t\_s = N[With[{TMP1 = Abs[1.0], TMP2 = Sign[t]}, TMP1 * If[TMP2 == 0, 1, TMP2]], $MachinePrecision]
            code[t$95$s_, t$95$m_, l_, k_] := N[(t$95$s * If[LessEqual[k, 3.6e-59], N[(N[(N[(2.0 * N[(N[(l / k), $MachinePrecision] / N[(k / l), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[(t$95$m * k), $MachinePrecision]), $MachinePrecision] / k), $MachinePrecision], N[(N[(l / k), $MachinePrecision] * N[(l * N[(N[(2.0 / N[(N[Sin[k], $MachinePrecision] * N[Tan[k], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[(t$95$m * k), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]), $MachinePrecision]
            
            \begin{array}{l}
            t\_m = \left|t\right|
            \\
            t\_s = \mathsf{copysign}\left(1, t\right)
            
            \\
            t\_s \cdot \begin{array}{l}
            \mathbf{if}\;k \leq 3.6 \cdot 10^{-59}:\\
            \;\;\;\;\frac{\frac{2 \cdot \frac{\frac{\ell}{k}}{\frac{k}{\ell}}}{t\_m \cdot k}}{k}\\
            
            \mathbf{else}:\\
            \;\;\;\;\frac{\ell}{k} \cdot \left(\ell \cdot \frac{\frac{2}{\sin k \cdot \tan k}}{t\_m \cdot k}\right)\\
            
            
            \end{array}
            \end{array}
            
            Derivation
            1. Split input into 2 regimes
            2. if k < 3.6e-59

              1. Initial program 37.8%

                \[\frac{2}{\left(\left(\frac{{t}^{3}}{\ell \cdot \ell} \cdot \sin k\right) \cdot \tan k\right) \cdot \left(\left(1 + {\left(\frac{k}{t}\right)}^{2}\right) - 1\right)} \]
              2. Add Preprocessing
              3. Taylor expanded in t around 0

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

                  \[\leadsto \color{blue}{\frac{2 \cdot \left({\ell}^{2} \cdot \cos k\right)}{{k}^{2} \cdot \left(t \cdot {\sin k}^{2}\right)}} \]
                2. lower-/.f64N/A

                  \[\leadsto \color{blue}{\frac{2 \cdot \left({\ell}^{2} \cdot \cos k\right)}{{k}^{2} \cdot \left(t \cdot {\sin k}^{2}\right)}} \]
                3. lower-*.f64N/A

                  \[\leadsto \frac{\color{blue}{2 \cdot \left({\ell}^{2} \cdot \cos k\right)}}{{k}^{2} \cdot \left(t \cdot {\sin k}^{2}\right)} \]
                4. unpow2N/A

                  \[\leadsto \frac{2 \cdot \left(\color{blue}{\left(\ell \cdot \ell\right)} \cdot \cos k\right)}{{k}^{2} \cdot \left(t \cdot {\sin k}^{2}\right)} \]
                5. associate-*l*N/A

                  \[\leadsto \frac{2 \cdot \color{blue}{\left(\ell \cdot \left(\ell \cdot \cos k\right)\right)}}{{k}^{2} \cdot \left(t \cdot {\sin k}^{2}\right)} \]
                6. *-commutativeN/A

                  \[\leadsto \frac{2 \cdot \left(\ell \cdot \color{blue}{\left(\cos k \cdot \ell\right)}\right)}{{k}^{2} \cdot \left(t \cdot {\sin k}^{2}\right)} \]
                7. lower-*.f64N/A

                  \[\leadsto \frac{2 \cdot \color{blue}{\left(\ell \cdot \left(\cos k \cdot \ell\right)\right)}}{{k}^{2} \cdot \left(t \cdot {\sin k}^{2}\right)} \]
                8. *-commutativeN/A

                  \[\leadsto \frac{2 \cdot \left(\ell \cdot \color{blue}{\left(\ell \cdot \cos k\right)}\right)}{{k}^{2} \cdot \left(t \cdot {\sin k}^{2}\right)} \]
                9. lower-*.f64N/A

                  \[\leadsto \frac{2 \cdot \left(\ell \cdot \color{blue}{\left(\ell \cdot \cos k\right)}\right)}{{k}^{2} \cdot \left(t \cdot {\sin k}^{2}\right)} \]
                10. lower-cos.f64N/A

                  \[\leadsto \frac{2 \cdot \left(\ell \cdot \left(\ell \cdot \color{blue}{\cos k}\right)\right)}{{k}^{2} \cdot \left(t \cdot {\sin k}^{2}\right)} \]
                11. associate-*r*N/A

                  \[\leadsto \frac{2 \cdot \left(\ell \cdot \left(\ell \cdot \cos k\right)\right)}{\color{blue}{\left({k}^{2} \cdot t\right) \cdot {\sin k}^{2}}} \]
                12. *-commutativeN/A

                  \[\leadsto \frac{2 \cdot \left(\ell \cdot \left(\ell \cdot \cos k\right)\right)}{\color{blue}{{\sin k}^{2} \cdot \left({k}^{2} \cdot t\right)}} \]
                13. lower-*.f64N/A

                  \[\leadsto \frac{2 \cdot \left(\ell \cdot \left(\ell \cdot \cos k\right)\right)}{\color{blue}{{\sin k}^{2} \cdot \left({k}^{2} \cdot t\right)}} \]
                14. lower-pow.f64N/A

                  \[\leadsto \frac{2 \cdot \left(\ell \cdot \left(\ell \cdot \cos k\right)\right)}{\color{blue}{{\sin k}^{2}} \cdot \left({k}^{2} \cdot t\right)} \]
                15. lower-sin.f64N/A

                  \[\leadsto \frac{2 \cdot \left(\ell \cdot \left(\ell \cdot \cos k\right)\right)}{{\color{blue}{\sin k}}^{2} \cdot \left({k}^{2} \cdot t\right)} \]
                16. *-commutativeN/A

                  \[\leadsto \frac{2 \cdot \left(\ell \cdot \left(\ell \cdot \cos k\right)\right)}{{\sin k}^{2} \cdot \color{blue}{\left(t \cdot {k}^{2}\right)}} \]
                17. lower-*.f64N/A

                  \[\leadsto \frac{2 \cdot \left(\ell \cdot \left(\ell \cdot \cos k\right)\right)}{{\sin k}^{2} \cdot \color{blue}{\left(t \cdot {k}^{2}\right)}} \]
                18. unpow2N/A

                  \[\leadsto \frac{2 \cdot \left(\ell \cdot \left(\ell \cdot \cos k\right)\right)}{{\sin k}^{2} \cdot \left(t \cdot \color{blue}{\left(k \cdot k\right)}\right)} \]
                19. lower-*.f6473.1

                  \[\leadsto \frac{2 \cdot \left(\ell \cdot \left(\ell \cdot \cos k\right)\right)}{{\sin k}^{2} \cdot \left(t \cdot \color{blue}{\left(k \cdot k\right)}\right)} \]
              5. Applied rewrites73.1%

                \[\leadsto \color{blue}{\frac{2 \cdot \left(\ell \cdot \left(\ell \cdot \cos k\right)\right)}{{\sin k}^{2} \cdot \left(t \cdot \left(k \cdot k\right)\right)}} \]
              6. Step-by-step derivation
                1. Applied rewrites69.8%

                  \[\leadsto \frac{\frac{\frac{\ell \cdot \left(\left(\ell \cdot \cos k\right) \cdot 2\right)}{0.5 - 0.5 \cdot \cos \left(k + k\right)}}{t \cdot k}}{\color{blue}{k}} \]
                2. Taylor expanded in k around 0

                  \[\leadsto \frac{\frac{2 \cdot \frac{{\ell}^{2}}{{k}^{2}}}{t \cdot k}}{k} \]
                3. Step-by-step derivation
                  1. Applied rewrites77.7%

                    \[\leadsto \frac{\frac{2 \cdot \left(\ell \cdot \frac{\ell}{k \cdot k}\right)}{t \cdot k}}{k} \]
                  2. Step-by-step derivation
                    1. Applied rewrites80.0%

                      \[\leadsto \frac{\frac{2 \cdot \frac{\frac{\ell}{k}}{\frac{k}{\ell}}}{t \cdot k}}{k} \]

                    if 3.6e-59 < k

                    1. Initial program 31.3%

                      \[\frac{2}{\left(\left(\frac{{t}^{3}}{\ell \cdot \ell} \cdot \sin k\right) \cdot \tan k\right) \cdot \left(\left(1 + {\left(\frac{k}{t}\right)}^{2}\right) - 1\right)} \]
                    2. Add Preprocessing
                    3. Taylor expanded in t around 0

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

                        \[\leadsto \color{blue}{\frac{2 \cdot \left({\ell}^{2} \cdot \cos k\right)}{{k}^{2} \cdot \left(t \cdot {\sin k}^{2}\right)}} \]
                      2. lower-/.f64N/A

                        \[\leadsto \color{blue}{\frac{2 \cdot \left({\ell}^{2} \cdot \cos k\right)}{{k}^{2} \cdot \left(t \cdot {\sin k}^{2}\right)}} \]
                      3. lower-*.f64N/A

                        \[\leadsto \frac{\color{blue}{2 \cdot \left({\ell}^{2} \cdot \cos k\right)}}{{k}^{2} \cdot \left(t \cdot {\sin k}^{2}\right)} \]
                      4. unpow2N/A

                        \[\leadsto \frac{2 \cdot \left(\color{blue}{\left(\ell \cdot \ell\right)} \cdot \cos k\right)}{{k}^{2} \cdot \left(t \cdot {\sin k}^{2}\right)} \]
                      5. associate-*l*N/A

                        \[\leadsto \frac{2 \cdot \color{blue}{\left(\ell \cdot \left(\ell \cdot \cos k\right)\right)}}{{k}^{2} \cdot \left(t \cdot {\sin k}^{2}\right)} \]
                      6. *-commutativeN/A

                        \[\leadsto \frac{2 \cdot \left(\ell \cdot \color{blue}{\left(\cos k \cdot \ell\right)}\right)}{{k}^{2} \cdot \left(t \cdot {\sin k}^{2}\right)} \]
                      7. lower-*.f64N/A

                        \[\leadsto \frac{2 \cdot \color{blue}{\left(\ell \cdot \left(\cos k \cdot \ell\right)\right)}}{{k}^{2} \cdot \left(t \cdot {\sin k}^{2}\right)} \]
                      8. *-commutativeN/A

                        \[\leadsto \frac{2 \cdot \left(\ell \cdot \color{blue}{\left(\ell \cdot \cos k\right)}\right)}{{k}^{2} \cdot \left(t \cdot {\sin k}^{2}\right)} \]
                      9. lower-*.f64N/A

                        \[\leadsto \frac{2 \cdot \left(\ell \cdot \color{blue}{\left(\ell \cdot \cos k\right)}\right)}{{k}^{2} \cdot \left(t \cdot {\sin k}^{2}\right)} \]
                      10. lower-cos.f64N/A

                        \[\leadsto \frac{2 \cdot \left(\ell \cdot \left(\ell \cdot \color{blue}{\cos k}\right)\right)}{{k}^{2} \cdot \left(t \cdot {\sin k}^{2}\right)} \]
                      11. associate-*r*N/A

                        \[\leadsto \frac{2 \cdot \left(\ell \cdot \left(\ell \cdot \cos k\right)\right)}{\color{blue}{\left({k}^{2} \cdot t\right) \cdot {\sin k}^{2}}} \]
                      12. *-commutativeN/A

                        \[\leadsto \frac{2 \cdot \left(\ell \cdot \left(\ell \cdot \cos k\right)\right)}{\color{blue}{{\sin k}^{2} \cdot \left({k}^{2} \cdot t\right)}} \]
                      13. lower-*.f64N/A

                        \[\leadsto \frac{2 \cdot \left(\ell \cdot \left(\ell \cdot \cos k\right)\right)}{\color{blue}{{\sin k}^{2} \cdot \left({k}^{2} \cdot t\right)}} \]
                      14. lower-pow.f64N/A

                        \[\leadsto \frac{2 \cdot \left(\ell \cdot \left(\ell \cdot \cos k\right)\right)}{\color{blue}{{\sin k}^{2}} \cdot \left({k}^{2} \cdot t\right)} \]
                      15. lower-sin.f64N/A

                        \[\leadsto \frac{2 \cdot \left(\ell \cdot \left(\ell \cdot \cos k\right)\right)}{{\color{blue}{\sin k}}^{2} \cdot \left({k}^{2} \cdot t\right)} \]
                      16. *-commutativeN/A

                        \[\leadsto \frac{2 \cdot \left(\ell \cdot \left(\ell \cdot \cos k\right)\right)}{{\sin k}^{2} \cdot \color{blue}{\left(t \cdot {k}^{2}\right)}} \]
                      17. lower-*.f64N/A

                        \[\leadsto \frac{2 \cdot \left(\ell \cdot \left(\ell \cdot \cos k\right)\right)}{{\sin k}^{2} \cdot \color{blue}{\left(t \cdot {k}^{2}\right)}} \]
                      18. unpow2N/A

                        \[\leadsto \frac{2 \cdot \left(\ell \cdot \left(\ell \cdot \cos k\right)\right)}{{\sin k}^{2} \cdot \left(t \cdot \color{blue}{\left(k \cdot k\right)}\right)} \]
                      19. lower-*.f6474.0

                        \[\leadsto \frac{2 \cdot \left(\ell \cdot \left(\ell \cdot \cos k\right)\right)}{{\sin k}^{2} \cdot \left(t \cdot \color{blue}{\left(k \cdot k\right)}\right)} \]
                    5. Applied rewrites74.0%

                      \[\leadsto \color{blue}{\frac{2 \cdot \left(\ell \cdot \left(\ell \cdot \cos k\right)\right)}{{\sin k}^{2} \cdot \left(t \cdot \left(k \cdot k\right)\right)}} \]
                    6. Step-by-step derivation
                      1. Applied rewrites74.0%

                        \[\leadsto \frac{2 \cdot \ell}{t \cdot \left(0.5 - 0.5 \cdot \cos \left(k + k\right)\right)} \cdot \color{blue}{\frac{\ell \cdot \cos k}{k \cdot k}} \]
                      2. Step-by-step derivation
                        1. Applied rewrites86.3%

                          \[\leadsto \frac{\ell}{k} \cdot \color{blue}{\frac{\frac{\ell \cdot \left(2 \cdot \cos k\right)}{\mathsf{fma}\left(\cos \left(k + k\right), -0.5, 0.5\right)}}{t \cdot k}} \]
                        2. Step-by-step derivation
                          1. Applied rewrites94.7%

                            \[\leadsto \frac{\ell}{k} \cdot \left(\ell \cdot \color{blue}{\frac{\frac{2}{\sin k \cdot \tan k}}{k \cdot t}}\right) \]
                        3. Recombined 2 regimes into one program.
                        4. Final simplification84.5%

                          \[\leadsto \begin{array}{l} \mathbf{if}\;k \leq 3.6 \cdot 10^{-59}:\\ \;\;\;\;\frac{\frac{2 \cdot \frac{\frac{\ell}{k}}{\frac{k}{\ell}}}{t \cdot k}}{k}\\ \mathbf{else}:\\ \;\;\;\;\frac{\ell}{k} \cdot \left(\ell \cdot \frac{\frac{2}{\sin k \cdot \tan k}}{t \cdot k}\right)\\ \end{array} \]
                        5. Add Preprocessing

                        Reproduce

                        ?
                        herbie shell --seed 2024228 
                        (FPCore (t l k)
                          :name "Toniolo and Linder, Equation (10-)"
                          :precision binary64
                          (/ 2.0 (* (* (* (/ (pow t 3.0) (* l l)) (sin k)) (tan k)) (- (+ 1.0 (pow (/ k t) 2.0)) 1.0))))