Toniolo and Linder, Equation (7)

Percentage Accurate: 33.3% → 84.8%
Time: 25.5s
Alternatives: 8
Speedup: 225.0×

Specification

?
\[\begin{array}{l} \\ \frac{\sqrt{2} \cdot t}{\sqrt{\frac{x + 1}{x - 1} \cdot \left(\ell \cdot \ell + 2 \cdot \left(t \cdot t\right)\right) - \ell \cdot \ell}} \end{array} \]
(FPCore (x l t)
 :precision binary64
 (/
  (* (sqrt 2.0) t)
  (sqrt (- (* (/ (+ x 1.0) (- x 1.0)) (+ (* l l) (* 2.0 (* t t)))) (* l l)))))
double code(double x, double l, double t) {
	return (sqrt(2.0) * t) / sqrt(((((x + 1.0) / (x - 1.0)) * ((l * l) + (2.0 * (t * t)))) - (l * l)));
}
real(8) function code(x, l, t)
    real(8), intent (in) :: x
    real(8), intent (in) :: l
    real(8), intent (in) :: t
    code = (sqrt(2.0d0) * t) / sqrt(((((x + 1.0d0) / (x - 1.0d0)) * ((l * l) + (2.0d0 * (t * t)))) - (l * l)))
end function
public static double code(double x, double l, double t) {
	return (Math.sqrt(2.0) * t) / Math.sqrt(((((x + 1.0) / (x - 1.0)) * ((l * l) + (2.0 * (t * t)))) - (l * l)));
}
def code(x, l, t):
	return (math.sqrt(2.0) * t) / math.sqrt(((((x + 1.0) / (x - 1.0)) * ((l * l) + (2.0 * (t * t)))) - (l * l)))
function code(x, l, t)
	return Float64(Float64(sqrt(2.0) * t) / sqrt(Float64(Float64(Float64(Float64(x + 1.0) / Float64(x - 1.0)) * Float64(Float64(l * l) + Float64(2.0 * Float64(t * t)))) - Float64(l * l))))
end
function tmp = code(x, l, t)
	tmp = (sqrt(2.0) * t) / sqrt(((((x + 1.0) / (x - 1.0)) * ((l * l) + (2.0 * (t * t)))) - (l * l)));
end
code[x_, l_, t_] := N[(N[(N[Sqrt[2.0], $MachinePrecision] * t), $MachinePrecision] / N[Sqrt[N[(N[(N[(N[(x + 1.0), $MachinePrecision] / N[(x - 1.0), $MachinePrecision]), $MachinePrecision] * N[(N[(l * l), $MachinePrecision] + N[(2.0 * N[(t * t), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] - N[(l * l), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{\sqrt{2} \cdot t}{\sqrt{\frac{x + 1}{x - 1} \cdot \left(\ell \cdot \ell + 2 \cdot \left(t \cdot t\right)\right) - \ell \cdot \ell}}
\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 8 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: 33.3% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \frac{\sqrt{2} \cdot t}{\sqrt{\frac{x + 1}{x - 1} \cdot \left(\ell \cdot \ell + 2 \cdot \left(t \cdot t\right)\right) - \ell \cdot \ell}} \end{array} \]
(FPCore (x l t)
 :precision binary64
 (/
  (* (sqrt 2.0) t)
  (sqrt (- (* (/ (+ x 1.0) (- x 1.0)) (+ (* l l) (* 2.0 (* t t)))) (* l l)))))
double code(double x, double l, double t) {
	return (sqrt(2.0) * t) / sqrt(((((x + 1.0) / (x - 1.0)) * ((l * l) + (2.0 * (t * t)))) - (l * l)));
}
real(8) function code(x, l, t)
    real(8), intent (in) :: x
    real(8), intent (in) :: l
    real(8), intent (in) :: t
    code = (sqrt(2.0d0) * t) / sqrt(((((x + 1.0d0) / (x - 1.0d0)) * ((l * l) + (2.0d0 * (t * t)))) - (l * l)))
end function
public static double code(double x, double l, double t) {
	return (Math.sqrt(2.0) * t) / Math.sqrt(((((x + 1.0) / (x - 1.0)) * ((l * l) + (2.0 * (t * t)))) - (l * l)));
}
def code(x, l, t):
	return (math.sqrt(2.0) * t) / math.sqrt(((((x + 1.0) / (x - 1.0)) * ((l * l) + (2.0 * (t * t)))) - (l * l)))
function code(x, l, t)
	return Float64(Float64(sqrt(2.0) * t) / sqrt(Float64(Float64(Float64(Float64(x + 1.0) / Float64(x - 1.0)) * Float64(Float64(l * l) + Float64(2.0 * Float64(t * t)))) - Float64(l * l))))
end
function tmp = code(x, l, t)
	tmp = (sqrt(2.0) * t) / sqrt(((((x + 1.0) / (x - 1.0)) * ((l * l) + (2.0 * (t * t)))) - (l * l)));
end
code[x_, l_, t_] := N[(N[(N[Sqrt[2.0], $MachinePrecision] * t), $MachinePrecision] / N[Sqrt[N[(N[(N[(N[(x + 1.0), $MachinePrecision] / N[(x - 1.0), $MachinePrecision]), $MachinePrecision] * N[(N[(l * l), $MachinePrecision] + N[(2.0 * N[(t * t), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] - N[(l * l), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{\sqrt{2} \cdot t}{\sqrt{\frac{x + 1}{x - 1} \cdot \left(\ell \cdot \ell + 2 \cdot \left(t \cdot t\right)\right) - \ell \cdot \ell}}
\end{array}

Alternative 1: 84.8% accurate, 0.2× speedup?

\[\begin{array}{l} t\_m = \left|t\right| \\ t\_s = \mathsf{copysign}\left(1, t\right) \\ \begin{array}{l} t_2 := 2 \cdot {t\_m}^{2}\\ t_3 := t\_2 + {\ell}^{2}\\ t_4 := t\_3 - -1 \cdot t\_3\\ t_5 := \sqrt{2} \cdot t\_m\\ t\_s \cdot \begin{array}{l} \mathbf{if}\;t\_m \leq 2.7 \cdot 10^{-158}:\\ \;\;\;\;\frac{t\_5}{0.5 \cdot \frac{t\_4}{t\_m \cdot \left(x \cdot \sqrt{2}\right)} + t\_m \cdot \sqrt{2}}\\ \mathbf{elif}\;t\_m \leq 5 \cdot 10^{-9}:\\ \;\;\;\;\frac{t\_5}{\sqrt{-1 \cdot \frac{\left(-1 \cdot t\_4 + -1 \cdot \frac{t\_3}{x}\right) - \left(2 \cdot \frac{{t\_m}^{2}}{x} + \frac{{\ell}^{2}}{x}\right)}{x} + t\_2}}\\ \mathbf{else}:\\ \;\;\;\;{\left(\frac{1 + x}{x + -1}\right)}^{-0.5}\\ \end{array} \end{array} \end{array} \]
t\_m = (fabs.f64 t)
t\_s = (copysign.f64 #s(literal 1 binary64) t)
(FPCore (t_s x l t_m)
 :precision binary64
 (let* ((t_2 (* 2.0 (pow t_m 2.0)))
        (t_3 (+ t_2 (pow l 2.0)))
        (t_4 (- t_3 (* -1.0 t_3)))
        (t_5 (* (sqrt 2.0) t_m)))
   (*
    t_s
    (if (<= t_m 2.7e-158)
      (/ t_5 (+ (* 0.5 (/ t_4 (* t_m (* x (sqrt 2.0))))) (* t_m (sqrt 2.0))))
      (if (<= t_m 5e-9)
        (/
         t_5
         (sqrt
          (+
           (*
            -1.0
            (/
             (-
              (+ (* -1.0 t_4) (* -1.0 (/ t_3 x)))
              (+ (* 2.0 (/ (pow t_m 2.0) x)) (/ (pow l 2.0) x)))
             x))
           t_2)))
        (pow (/ (+ 1.0 x) (+ x -1.0)) -0.5))))))
t\_m = fabs(t);
t\_s = copysign(1.0, t);
double code(double t_s, double x, double l, double t_m) {
	double t_2 = 2.0 * pow(t_m, 2.0);
	double t_3 = t_2 + pow(l, 2.0);
	double t_4 = t_3 - (-1.0 * t_3);
	double t_5 = sqrt(2.0) * t_m;
	double tmp;
	if (t_m <= 2.7e-158) {
		tmp = t_5 / ((0.5 * (t_4 / (t_m * (x * sqrt(2.0))))) + (t_m * sqrt(2.0)));
	} else if (t_m <= 5e-9) {
		tmp = t_5 / sqrt(((-1.0 * ((((-1.0 * t_4) + (-1.0 * (t_3 / x))) - ((2.0 * (pow(t_m, 2.0) / x)) + (pow(l, 2.0) / x))) / x)) + t_2));
	} else {
		tmp = pow(((1.0 + x) / (x + -1.0)), -0.5);
	}
	return t_s * tmp;
}
t\_m = abs(t)
t\_s = copysign(1.0d0, t)
real(8) function code(t_s, x, l, t_m)
    real(8), intent (in) :: t_s
    real(8), intent (in) :: x
    real(8), intent (in) :: l
    real(8), intent (in) :: t_m
    real(8) :: t_2
    real(8) :: t_3
    real(8) :: t_4
    real(8) :: t_5
    real(8) :: tmp
    t_2 = 2.0d0 * (t_m ** 2.0d0)
    t_3 = t_2 + (l ** 2.0d0)
    t_4 = t_3 - ((-1.0d0) * t_3)
    t_5 = sqrt(2.0d0) * t_m
    if (t_m <= 2.7d-158) then
        tmp = t_5 / ((0.5d0 * (t_4 / (t_m * (x * sqrt(2.0d0))))) + (t_m * sqrt(2.0d0)))
    else if (t_m <= 5d-9) then
        tmp = t_5 / sqrt((((-1.0d0) * (((((-1.0d0) * t_4) + ((-1.0d0) * (t_3 / x))) - ((2.0d0 * ((t_m ** 2.0d0) / x)) + ((l ** 2.0d0) / x))) / x)) + t_2))
    else
        tmp = ((1.0d0 + x) / (x + (-1.0d0))) ** (-0.5d0)
    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 x, double l, double t_m) {
	double t_2 = 2.0 * Math.pow(t_m, 2.0);
	double t_3 = t_2 + Math.pow(l, 2.0);
	double t_4 = t_3 - (-1.0 * t_3);
	double t_5 = Math.sqrt(2.0) * t_m;
	double tmp;
	if (t_m <= 2.7e-158) {
		tmp = t_5 / ((0.5 * (t_4 / (t_m * (x * Math.sqrt(2.0))))) + (t_m * Math.sqrt(2.0)));
	} else if (t_m <= 5e-9) {
		tmp = t_5 / Math.sqrt(((-1.0 * ((((-1.0 * t_4) + (-1.0 * (t_3 / x))) - ((2.0 * (Math.pow(t_m, 2.0) / x)) + (Math.pow(l, 2.0) / x))) / x)) + t_2));
	} else {
		tmp = Math.pow(((1.0 + x) / (x + -1.0)), -0.5);
	}
	return t_s * tmp;
}
t\_m = math.fabs(t)
t\_s = math.copysign(1.0, t)
def code(t_s, x, l, t_m):
	t_2 = 2.0 * math.pow(t_m, 2.0)
	t_3 = t_2 + math.pow(l, 2.0)
	t_4 = t_3 - (-1.0 * t_3)
	t_5 = math.sqrt(2.0) * t_m
	tmp = 0
	if t_m <= 2.7e-158:
		tmp = t_5 / ((0.5 * (t_4 / (t_m * (x * math.sqrt(2.0))))) + (t_m * math.sqrt(2.0)))
	elif t_m <= 5e-9:
		tmp = t_5 / math.sqrt(((-1.0 * ((((-1.0 * t_4) + (-1.0 * (t_3 / x))) - ((2.0 * (math.pow(t_m, 2.0) / x)) + (math.pow(l, 2.0) / x))) / x)) + t_2))
	else:
		tmp = math.pow(((1.0 + x) / (x + -1.0)), -0.5)
	return t_s * tmp
t\_m = abs(t)
t\_s = copysign(1.0, t)
function code(t_s, x, l, t_m)
	t_2 = Float64(2.0 * (t_m ^ 2.0))
	t_3 = Float64(t_2 + (l ^ 2.0))
	t_4 = Float64(t_3 - Float64(-1.0 * t_3))
	t_5 = Float64(sqrt(2.0) * t_m)
	tmp = 0.0
	if (t_m <= 2.7e-158)
		tmp = Float64(t_5 / Float64(Float64(0.5 * Float64(t_4 / Float64(t_m * Float64(x * sqrt(2.0))))) + Float64(t_m * sqrt(2.0))));
	elseif (t_m <= 5e-9)
		tmp = Float64(t_5 / sqrt(Float64(Float64(-1.0 * Float64(Float64(Float64(Float64(-1.0 * t_4) + Float64(-1.0 * Float64(t_3 / x))) - Float64(Float64(2.0 * Float64((t_m ^ 2.0) / x)) + Float64((l ^ 2.0) / x))) / x)) + t_2)));
	else
		tmp = Float64(Float64(1.0 + x) / Float64(x + -1.0)) ^ -0.5;
	end
	return Float64(t_s * tmp)
end
t\_m = abs(t);
t\_s = sign(t) * abs(1.0);
function tmp_2 = code(t_s, x, l, t_m)
	t_2 = 2.0 * (t_m ^ 2.0);
	t_3 = t_2 + (l ^ 2.0);
	t_4 = t_3 - (-1.0 * t_3);
	t_5 = sqrt(2.0) * t_m;
	tmp = 0.0;
	if (t_m <= 2.7e-158)
		tmp = t_5 / ((0.5 * (t_4 / (t_m * (x * sqrt(2.0))))) + (t_m * sqrt(2.0)));
	elseif (t_m <= 5e-9)
		tmp = t_5 / sqrt(((-1.0 * ((((-1.0 * t_4) + (-1.0 * (t_3 / x))) - ((2.0 * ((t_m ^ 2.0) / x)) + ((l ^ 2.0) / x))) / x)) + t_2));
	else
		tmp = ((1.0 + x) / (x + -1.0)) ^ -0.5;
	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_, x_, l_, t$95$m_] := Block[{t$95$2 = N[(2.0 * N[Power[t$95$m, 2.0], $MachinePrecision]), $MachinePrecision]}, Block[{t$95$3 = N[(t$95$2 + N[Power[l, 2.0], $MachinePrecision]), $MachinePrecision]}, Block[{t$95$4 = N[(t$95$3 - N[(-1.0 * t$95$3), $MachinePrecision]), $MachinePrecision]}, Block[{t$95$5 = N[(N[Sqrt[2.0], $MachinePrecision] * t$95$m), $MachinePrecision]}, N[(t$95$s * If[LessEqual[t$95$m, 2.7e-158], N[(t$95$5 / N[(N[(0.5 * N[(t$95$4 / N[(t$95$m * N[(x * N[Sqrt[2.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(t$95$m * N[Sqrt[2.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], If[LessEqual[t$95$m, 5e-9], N[(t$95$5 / N[Sqrt[N[(N[(-1.0 * N[(N[(N[(N[(-1.0 * t$95$4), $MachinePrecision] + N[(-1.0 * N[(t$95$3 / x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] - N[(N[(2.0 * N[(N[Power[t$95$m, 2.0], $MachinePrecision] / x), $MachinePrecision]), $MachinePrecision] + N[(N[Power[l, 2.0], $MachinePrecision] / x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / x), $MachinePrecision]), $MachinePrecision] + t$95$2), $MachinePrecision]], $MachinePrecision]), $MachinePrecision], N[Power[N[(N[(1.0 + x), $MachinePrecision] / N[(x + -1.0), $MachinePrecision]), $MachinePrecision], -0.5], $MachinePrecision]]]), $MachinePrecision]]]]]
\begin{array}{l}
t\_m = \left|t\right|
\\
t\_s = \mathsf{copysign}\left(1, t\right)

\\
\begin{array}{l}
t_2 := 2 \cdot {t\_m}^{2}\\
t_3 := t\_2 + {\ell}^{2}\\
t_4 := t\_3 - -1 \cdot t\_3\\
t_5 := \sqrt{2} \cdot t\_m\\
t\_s \cdot \begin{array}{l}
\mathbf{if}\;t\_m \leq 2.7 \cdot 10^{-158}:\\
\;\;\;\;\frac{t\_5}{0.5 \cdot \frac{t\_4}{t\_m \cdot \left(x \cdot \sqrt{2}\right)} + t\_m \cdot \sqrt{2}}\\

\mathbf{elif}\;t\_m \leq 5 \cdot 10^{-9}:\\
\;\;\;\;\frac{t\_5}{\sqrt{-1 \cdot \frac{\left(-1 \cdot t\_4 + -1 \cdot \frac{t\_3}{x}\right) - \left(2 \cdot \frac{{t\_m}^{2}}{x} + \frac{{\ell}^{2}}{x}\right)}{x} + t\_2}}\\

\mathbf{else}:\\
\;\;\;\;{\left(\frac{1 + x}{x + -1}\right)}^{-0.5}\\


\end{array}
\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if t < 2.6999999999999998e-158

    1. Initial program 31.0%

      \[\frac{\sqrt{2} \cdot t}{\sqrt{\frac{x + 1}{x - 1} \cdot \left(\ell \cdot \ell + 2 \cdot \left(t \cdot t\right)\right) - \ell \cdot \ell}} \]
    2. Add Preprocessing
    3. Taylor expanded in x around inf 13.2%

      \[\leadsto \frac{\sqrt{2} \cdot t}{\color{blue}{0.5 \cdot \frac{\left(2 \cdot {t}^{2} + {\ell}^{2}\right) - -1 \cdot \left(2 \cdot {t}^{2} + {\ell}^{2}\right)}{t \cdot \left(x \cdot \sqrt{2}\right)} + t \cdot \sqrt{2}}} \]

    if 2.6999999999999998e-158 < t < 5.0000000000000001e-9

    1. Initial program 44.7%

      \[\frac{\sqrt{2} \cdot t}{\sqrt{\frac{x + 1}{x - 1} \cdot \left(\ell \cdot \ell + 2 \cdot \left(t \cdot t\right)\right) - \ell \cdot \ell}} \]
    2. Add Preprocessing
    3. Taylor expanded in x around -inf 73.0%

      \[\leadsto \frac{\sqrt{2} \cdot t}{\sqrt{\color{blue}{-1 \cdot \frac{\left(-1 \cdot \left(\left(2 \cdot {t}^{2} + {\ell}^{2}\right) - -1 \cdot \left(2 \cdot {t}^{2} + {\ell}^{2}\right)\right) + -1 \cdot \frac{2 \cdot {t}^{2} + {\ell}^{2}}{x}\right) - \left(2 \cdot \frac{{t}^{2}}{x} + \frac{{\ell}^{2}}{x}\right)}{x} + 2 \cdot {t}^{2}}}} \]

    if 5.0000000000000001e-9 < t

    1. Initial program 41.9%

      \[\frac{\sqrt{2} \cdot t}{\sqrt{\frac{x + 1}{x - 1} \cdot \left(\ell \cdot \ell + 2 \cdot \left(t \cdot t\right)\right) - \ell \cdot \ell}} \]
    2. Simplified41.8%

      \[\leadsto \color{blue}{\sqrt{2} \cdot \frac{t}{\sqrt{\mathsf{fma}\left(x + 1, \frac{\mathsf{fma}\left(2, t \cdot t, \ell \cdot \ell\right)}{x + -1}, -\ell \cdot \ell\right)}}} \]
    3. Add Preprocessing
    4. Taylor expanded in t around inf 91.4%

      \[\leadsto \sqrt{2} \cdot \frac{t}{\color{blue}{\left(t \cdot \sqrt{2}\right) \cdot \sqrt{\frac{1 + x}{x - 1}}}} \]
    5. Taylor expanded in t around 0 91.7%

      \[\leadsto \color{blue}{\sqrt{\frac{x - 1}{1 + x}}} \]
    6. Step-by-step derivation
      1. clear-num91.7%

        \[\leadsto \sqrt{\color{blue}{\frac{1}{\frac{1 + x}{x - 1}}}} \]
      2. sub-neg91.7%

        \[\leadsto \sqrt{\frac{1}{\frac{1 + x}{\color{blue}{x + \left(-1\right)}}}} \]
      3. metadata-eval91.7%

        \[\leadsto \sqrt{\frac{1}{\frac{1 + x}{x + \color{blue}{-1}}}} \]
      4. sqrt-div91.7%

        \[\leadsto \color{blue}{\frac{\sqrt{1}}{\sqrt{\frac{1 + x}{x + -1}}}} \]
      5. metadata-eval91.7%

        \[\leadsto \frac{\color{blue}{1}}{\sqrt{\frac{1 + x}{x + -1}}} \]
      6. +-commutative91.7%

        \[\leadsto \frac{1}{\sqrt{\frac{\color{blue}{x + 1}}{x + -1}}} \]
    7. Applied egg-rr91.7%

      \[\leadsto \color{blue}{\frac{1}{\sqrt{\frac{x + 1}{x + -1}}}} \]
    8. Step-by-step derivation
      1. pow1/291.7%

        \[\leadsto \frac{1}{\color{blue}{{\left(\frac{x + 1}{x + -1}\right)}^{0.5}}} \]
      2. pow-flip91.7%

        \[\leadsto \color{blue}{{\left(\frac{x + 1}{x + -1}\right)}^{\left(-0.5\right)}} \]
      3. +-commutative91.7%

        \[\leadsto {\left(\frac{\color{blue}{1 + x}}{x + -1}\right)}^{\left(-0.5\right)} \]
      4. metadata-eval91.7%

        \[\leadsto {\left(\frac{1 + x}{x + -1}\right)}^{\color{blue}{-0.5}} \]
    9. Applied egg-rr91.7%

      \[\leadsto \color{blue}{{\left(\frac{1 + x}{x + -1}\right)}^{-0.5}} \]
  3. Recombined 3 regimes into one program.
  4. Add Preprocessing

Alternative 2: 81.3% accurate, 0.3× speedup?

\[\begin{array}{l} t\_m = \left|t\right| \\ t\_s = \mathsf{copysign}\left(1, t\right) \\ \begin{array}{l} t_2 := 2 \cdot {t\_m}^{2}\\ t\_s \cdot \begin{array}{l} \mathbf{if}\;t\_m \leq 1.02 \cdot 10^{-160}:\\ \;\;\;\;\frac{1}{1 + \left(\frac{0.5}{{x}^{2}} + \left(\frac{1}{x} + 0.5 \cdot \frac{1}{{x}^{3}}\right)\right)}\\ \mathbf{elif}\;t\_m \leq 2.2 \cdot 10^{-10}:\\ \;\;\;\;\sqrt{2} \cdot \frac{t\_m}{\sqrt{\left(2 \cdot \frac{{t\_m}^{2}}{x} + \left(t\_2 + \frac{{\ell}^{2}}{x}\right)\right) - -1 \cdot \frac{t\_2 + {\ell}^{2}}{x}}}\\ \mathbf{else}:\\ \;\;\;\;{\left(\frac{1 + x}{x + -1}\right)}^{-0.5}\\ \end{array} \end{array} \end{array} \]
t\_m = (fabs.f64 t)
t\_s = (copysign.f64 #s(literal 1 binary64) t)
(FPCore (t_s x l t_m)
 :precision binary64
 (let* ((t_2 (* 2.0 (pow t_m 2.0))))
   (*
    t_s
    (if (<= t_m 1.02e-160)
      (/
       1.0
       (+
        1.0
        (+ (/ 0.5 (pow x 2.0)) (+ (/ 1.0 x) (* 0.5 (/ 1.0 (pow x 3.0)))))))
      (if (<= t_m 2.2e-10)
        (*
         (sqrt 2.0)
         (/
          t_m
          (sqrt
           (-
            (+ (* 2.0 (/ (pow t_m 2.0) x)) (+ t_2 (/ (pow l 2.0) x)))
            (* -1.0 (/ (+ t_2 (pow l 2.0)) x))))))
        (pow (/ (+ 1.0 x) (+ x -1.0)) -0.5))))))
t\_m = fabs(t);
t\_s = copysign(1.0, t);
double code(double t_s, double x, double l, double t_m) {
	double t_2 = 2.0 * pow(t_m, 2.0);
	double tmp;
	if (t_m <= 1.02e-160) {
		tmp = 1.0 / (1.0 + ((0.5 / pow(x, 2.0)) + ((1.0 / x) + (0.5 * (1.0 / pow(x, 3.0))))));
	} else if (t_m <= 2.2e-10) {
		tmp = sqrt(2.0) * (t_m / sqrt((((2.0 * (pow(t_m, 2.0) / x)) + (t_2 + (pow(l, 2.0) / x))) - (-1.0 * ((t_2 + pow(l, 2.0)) / x)))));
	} else {
		tmp = pow(((1.0 + x) / (x + -1.0)), -0.5);
	}
	return t_s * tmp;
}
t\_m = abs(t)
t\_s = copysign(1.0d0, t)
real(8) function code(t_s, x, l, t_m)
    real(8), intent (in) :: t_s
    real(8), intent (in) :: x
    real(8), intent (in) :: l
    real(8), intent (in) :: t_m
    real(8) :: t_2
    real(8) :: tmp
    t_2 = 2.0d0 * (t_m ** 2.0d0)
    if (t_m <= 1.02d-160) then
        tmp = 1.0d0 / (1.0d0 + ((0.5d0 / (x ** 2.0d0)) + ((1.0d0 / x) + (0.5d0 * (1.0d0 / (x ** 3.0d0))))))
    else if (t_m <= 2.2d-10) then
        tmp = sqrt(2.0d0) * (t_m / sqrt((((2.0d0 * ((t_m ** 2.0d0) / x)) + (t_2 + ((l ** 2.0d0) / x))) - ((-1.0d0) * ((t_2 + (l ** 2.0d0)) / x)))))
    else
        tmp = ((1.0d0 + x) / (x + (-1.0d0))) ** (-0.5d0)
    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 x, double l, double t_m) {
	double t_2 = 2.0 * Math.pow(t_m, 2.0);
	double tmp;
	if (t_m <= 1.02e-160) {
		tmp = 1.0 / (1.0 + ((0.5 / Math.pow(x, 2.0)) + ((1.0 / x) + (0.5 * (1.0 / Math.pow(x, 3.0))))));
	} else if (t_m <= 2.2e-10) {
		tmp = Math.sqrt(2.0) * (t_m / Math.sqrt((((2.0 * (Math.pow(t_m, 2.0) / x)) + (t_2 + (Math.pow(l, 2.0) / x))) - (-1.0 * ((t_2 + Math.pow(l, 2.0)) / x)))));
	} else {
		tmp = Math.pow(((1.0 + x) / (x + -1.0)), -0.5);
	}
	return t_s * tmp;
}
t\_m = math.fabs(t)
t\_s = math.copysign(1.0, t)
def code(t_s, x, l, t_m):
	t_2 = 2.0 * math.pow(t_m, 2.0)
	tmp = 0
	if t_m <= 1.02e-160:
		tmp = 1.0 / (1.0 + ((0.5 / math.pow(x, 2.0)) + ((1.0 / x) + (0.5 * (1.0 / math.pow(x, 3.0))))))
	elif t_m <= 2.2e-10:
		tmp = math.sqrt(2.0) * (t_m / math.sqrt((((2.0 * (math.pow(t_m, 2.0) / x)) + (t_2 + (math.pow(l, 2.0) / x))) - (-1.0 * ((t_2 + math.pow(l, 2.0)) / x)))))
	else:
		tmp = math.pow(((1.0 + x) / (x + -1.0)), -0.5)
	return t_s * tmp
t\_m = abs(t)
t\_s = copysign(1.0, t)
function code(t_s, x, l, t_m)
	t_2 = Float64(2.0 * (t_m ^ 2.0))
	tmp = 0.0
	if (t_m <= 1.02e-160)
		tmp = Float64(1.0 / Float64(1.0 + Float64(Float64(0.5 / (x ^ 2.0)) + Float64(Float64(1.0 / x) + Float64(0.5 * Float64(1.0 / (x ^ 3.0)))))));
	elseif (t_m <= 2.2e-10)
		tmp = Float64(sqrt(2.0) * Float64(t_m / sqrt(Float64(Float64(Float64(2.0 * Float64((t_m ^ 2.0) / x)) + Float64(t_2 + Float64((l ^ 2.0) / x))) - Float64(-1.0 * Float64(Float64(t_2 + (l ^ 2.0)) / x))))));
	else
		tmp = Float64(Float64(1.0 + x) / Float64(x + -1.0)) ^ -0.5;
	end
	return Float64(t_s * tmp)
end
t\_m = abs(t);
t\_s = sign(t) * abs(1.0);
function tmp_2 = code(t_s, x, l, t_m)
	t_2 = 2.0 * (t_m ^ 2.0);
	tmp = 0.0;
	if (t_m <= 1.02e-160)
		tmp = 1.0 / (1.0 + ((0.5 / (x ^ 2.0)) + ((1.0 / x) + (0.5 * (1.0 / (x ^ 3.0))))));
	elseif (t_m <= 2.2e-10)
		tmp = sqrt(2.0) * (t_m / sqrt((((2.0 * ((t_m ^ 2.0) / x)) + (t_2 + ((l ^ 2.0) / x))) - (-1.0 * ((t_2 + (l ^ 2.0)) / x)))));
	else
		tmp = ((1.0 + x) / (x + -1.0)) ^ -0.5;
	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_, x_, l_, t$95$m_] := Block[{t$95$2 = N[(2.0 * N[Power[t$95$m, 2.0], $MachinePrecision]), $MachinePrecision]}, N[(t$95$s * If[LessEqual[t$95$m, 1.02e-160], N[(1.0 / N[(1.0 + N[(N[(0.5 / N[Power[x, 2.0], $MachinePrecision]), $MachinePrecision] + N[(N[(1.0 / x), $MachinePrecision] + N[(0.5 * N[(1.0 / N[Power[x, 3.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], If[LessEqual[t$95$m, 2.2e-10], N[(N[Sqrt[2.0], $MachinePrecision] * N[(t$95$m / N[Sqrt[N[(N[(N[(2.0 * N[(N[Power[t$95$m, 2.0], $MachinePrecision] / x), $MachinePrecision]), $MachinePrecision] + N[(t$95$2 + N[(N[Power[l, 2.0], $MachinePrecision] / x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] - N[(-1.0 * N[(N[(t$95$2 + N[Power[l, 2.0], $MachinePrecision]), $MachinePrecision] / x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[Power[N[(N[(1.0 + x), $MachinePrecision] / N[(x + -1.0), $MachinePrecision]), $MachinePrecision], -0.5], $MachinePrecision]]]), $MachinePrecision]]
\begin{array}{l}
t\_m = \left|t\right|
\\
t\_s = \mathsf{copysign}\left(1, t\right)

\\
\begin{array}{l}
t_2 := 2 \cdot {t\_m}^{2}\\
t\_s \cdot \begin{array}{l}
\mathbf{if}\;t\_m \leq 1.02 \cdot 10^{-160}:\\
\;\;\;\;\frac{1}{1 + \left(\frac{0.5}{{x}^{2}} + \left(\frac{1}{x} + 0.5 \cdot \frac{1}{{x}^{3}}\right)\right)}\\

\mathbf{elif}\;t\_m \leq 2.2 \cdot 10^{-10}:\\
\;\;\;\;\sqrt{2} \cdot \frac{t\_m}{\sqrt{\left(2 \cdot \frac{{t\_m}^{2}}{x} + \left(t\_2 + \frac{{\ell}^{2}}{x}\right)\right) - -1 \cdot \frac{t\_2 + {\ell}^{2}}{x}}}\\

\mathbf{else}:\\
\;\;\;\;{\left(\frac{1 + x}{x + -1}\right)}^{-0.5}\\


\end{array}
\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if t < 1.0200000000000001e-160

    1. Initial program 31.2%

      \[\frac{\sqrt{2} \cdot t}{\sqrt{\frac{x + 1}{x - 1} \cdot \left(\ell \cdot \ell + 2 \cdot \left(t \cdot t\right)\right) - \ell \cdot \ell}} \]
    2. Simplified28.1%

      \[\leadsto \color{blue}{\sqrt{2} \cdot \frac{t}{\sqrt{\mathsf{fma}\left(x + 1, \frac{\mathsf{fma}\left(2, t \cdot t, \ell \cdot \ell\right)}{x + -1}, -\ell \cdot \ell\right)}}} \]
    3. Add Preprocessing
    4. Taylor expanded in t around inf 8.1%

      \[\leadsto \sqrt{2} \cdot \frac{t}{\color{blue}{\left(t \cdot \sqrt{2}\right) \cdot \sqrt{\frac{1 + x}{x - 1}}}} \]
    5. Taylor expanded in t around 0 8.1%

      \[\leadsto \color{blue}{\sqrt{\frac{x - 1}{1 + x}}} \]
    6. Step-by-step derivation
      1. clear-num8.1%

        \[\leadsto \sqrt{\color{blue}{\frac{1}{\frac{1 + x}{x - 1}}}} \]
      2. sub-neg8.1%

        \[\leadsto \sqrt{\frac{1}{\frac{1 + x}{\color{blue}{x + \left(-1\right)}}}} \]
      3. metadata-eval8.1%

        \[\leadsto \sqrt{\frac{1}{\frac{1 + x}{x + \color{blue}{-1}}}} \]
      4. sqrt-div8.1%

        \[\leadsto \color{blue}{\frac{\sqrt{1}}{\sqrt{\frac{1 + x}{x + -1}}}} \]
      5. metadata-eval8.1%

        \[\leadsto \frac{\color{blue}{1}}{\sqrt{\frac{1 + x}{x + -1}}} \]
      6. +-commutative8.1%

        \[\leadsto \frac{1}{\sqrt{\frac{\color{blue}{x + 1}}{x + -1}}} \]
    7. Applied egg-rr8.1%

      \[\leadsto \color{blue}{\frac{1}{\sqrt{\frac{x + 1}{x + -1}}}} \]
    8. Taylor expanded in x around inf 8.1%

      \[\leadsto \frac{1}{\color{blue}{1 + \left(\frac{0.5}{{x}^{2}} + \left(\frac{1}{x} + 0.5 \cdot \frac{1}{{x}^{3}}\right)\right)}} \]

    if 1.0200000000000001e-160 < t < 2.1999999999999999e-10

    1. Initial program 43.3%

      \[\frac{\sqrt{2} \cdot t}{\sqrt{\frac{x + 1}{x - 1} \cdot \left(\ell \cdot \ell + 2 \cdot \left(t \cdot t\right)\right) - \ell \cdot \ell}} \]
    2. Simplified12.6%

      \[\leadsto \color{blue}{\sqrt{2} \cdot \frac{t}{\sqrt{\mathsf{fma}\left(x + 1, \frac{\mathsf{fma}\left(2, t \cdot t, \ell \cdot \ell\right)}{x + -1}, -\ell \cdot \ell\right)}}} \]
    3. Add Preprocessing
    4. Taylor expanded in x around inf 73.7%

      \[\leadsto \sqrt{2} \cdot \frac{t}{\sqrt{\color{blue}{\left(2 \cdot \frac{{t}^{2}}{x} + \left(2 \cdot {t}^{2} + \frac{{\ell}^{2}}{x}\right)\right) - -1 \cdot \frac{2 \cdot {t}^{2} + {\ell}^{2}}{x}}}} \]

    if 2.1999999999999999e-10 < t

    1. Initial program 41.9%

      \[\frac{\sqrt{2} \cdot t}{\sqrt{\frac{x + 1}{x - 1} \cdot \left(\ell \cdot \ell + 2 \cdot \left(t \cdot t\right)\right) - \ell \cdot \ell}} \]
    2. Simplified41.8%

      \[\leadsto \color{blue}{\sqrt{2} \cdot \frac{t}{\sqrt{\mathsf{fma}\left(x + 1, \frac{\mathsf{fma}\left(2, t \cdot t, \ell \cdot \ell\right)}{x + -1}, -\ell \cdot \ell\right)}}} \]
    3. Add Preprocessing
    4. Taylor expanded in t around inf 91.4%

      \[\leadsto \sqrt{2} \cdot \frac{t}{\color{blue}{\left(t \cdot \sqrt{2}\right) \cdot \sqrt{\frac{1 + x}{x - 1}}}} \]
    5. Taylor expanded in t around 0 91.7%

      \[\leadsto \color{blue}{\sqrt{\frac{x - 1}{1 + x}}} \]
    6. Step-by-step derivation
      1. clear-num91.7%

        \[\leadsto \sqrt{\color{blue}{\frac{1}{\frac{1 + x}{x - 1}}}} \]
      2. sub-neg91.7%

        \[\leadsto \sqrt{\frac{1}{\frac{1 + x}{\color{blue}{x + \left(-1\right)}}}} \]
      3. metadata-eval91.7%

        \[\leadsto \sqrt{\frac{1}{\frac{1 + x}{x + \color{blue}{-1}}}} \]
      4. sqrt-div91.7%

        \[\leadsto \color{blue}{\frac{\sqrt{1}}{\sqrt{\frac{1 + x}{x + -1}}}} \]
      5. metadata-eval91.7%

        \[\leadsto \frac{\color{blue}{1}}{\sqrt{\frac{1 + x}{x + -1}}} \]
      6. +-commutative91.7%

        \[\leadsto \frac{1}{\sqrt{\frac{\color{blue}{x + 1}}{x + -1}}} \]
    7. Applied egg-rr91.7%

      \[\leadsto \color{blue}{\frac{1}{\sqrt{\frac{x + 1}{x + -1}}}} \]
    8. Step-by-step derivation
      1. pow1/291.7%

        \[\leadsto \frac{1}{\color{blue}{{\left(\frac{x + 1}{x + -1}\right)}^{0.5}}} \]
      2. pow-flip91.7%

        \[\leadsto \color{blue}{{\left(\frac{x + 1}{x + -1}\right)}^{\left(-0.5\right)}} \]
      3. +-commutative91.7%

        \[\leadsto {\left(\frac{\color{blue}{1 + x}}{x + -1}\right)}^{\left(-0.5\right)} \]
      4. metadata-eval91.7%

        \[\leadsto {\left(\frac{1 + x}{x + -1}\right)}^{\color{blue}{-0.5}} \]
    9. Applied egg-rr91.7%

      \[\leadsto \color{blue}{{\left(\frac{1 + x}{x + -1}\right)}^{-0.5}} \]
  3. Recombined 3 regimes into one program.
  4. Add Preprocessing

Alternative 3: 81.3% accurate, 0.3× speedup?

\[\begin{array}{l} t\_m = \left|t\right| \\ t\_s = \mathsf{copysign}\left(1, t\right) \\ \begin{array}{l} t_2 := 2 \cdot {t\_m}^{2}\\ t\_s \cdot \begin{array}{l} \mathbf{if}\;t\_m \leq 1.55 \cdot 10^{-159}:\\ \;\;\;\;\frac{1}{1 + \left(\frac{0.5}{{x}^{2}} + \left(\frac{1}{x} + 0.5 \cdot \frac{1}{{x}^{3}}\right)\right)}\\ \mathbf{elif}\;t\_m \leq 6 \cdot 10^{-9}:\\ \;\;\;\;\frac{\sqrt{2} \cdot t\_m}{\sqrt{\left(2 \cdot \frac{{t\_m}^{2}}{x} + \left(t\_2 + \frac{{\ell}^{2}}{x}\right)\right) - -1 \cdot \frac{t\_2 + {\ell}^{2}}{x}}}\\ \mathbf{else}:\\ \;\;\;\;{\left(\frac{1 + x}{x + -1}\right)}^{-0.5}\\ \end{array} \end{array} \end{array} \]
t\_m = (fabs.f64 t)
t\_s = (copysign.f64 #s(literal 1 binary64) t)
(FPCore (t_s x l t_m)
 :precision binary64
 (let* ((t_2 (* 2.0 (pow t_m 2.0))))
   (*
    t_s
    (if (<= t_m 1.55e-159)
      (/
       1.0
       (+
        1.0
        (+ (/ 0.5 (pow x 2.0)) (+ (/ 1.0 x) (* 0.5 (/ 1.0 (pow x 3.0)))))))
      (if (<= t_m 6e-9)
        (/
         (* (sqrt 2.0) t_m)
         (sqrt
          (-
           (+ (* 2.0 (/ (pow t_m 2.0) x)) (+ t_2 (/ (pow l 2.0) x)))
           (* -1.0 (/ (+ t_2 (pow l 2.0)) x)))))
        (pow (/ (+ 1.0 x) (+ x -1.0)) -0.5))))))
t\_m = fabs(t);
t\_s = copysign(1.0, t);
double code(double t_s, double x, double l, double t_m) {
	double t_2 = 2.0 * pow(t_m, 2.0);
	double tmp;
	if (t_m <= 1.55e-159) {
		tmp = 1.0 / (1.0 + ((0.5 / pow(x, 2.0)) + ((1.0 / x) + (0.5 * (1.0 / pow(x, 3.0))))));
	} else if (t_m <= 6e-9) {
		tmp = (sqrt(2.0) * t_m) / sqrt((((2.0 * (pow(t_m, 2.0) / x)) + (t_2 + (pow(l, 2.0) / x))) - (-1.0 * ((t_2 + pow(l, 2.0)) / x))));
	} else {
		tmp = pow(((1.0 + x) / (x + -1.0)), -0.5);
	}
	return t_s * tmp;
}
t\_m = abs(t)
t\_s = copysign(1.0d0, t)
real(8) function code(t_s, x, l, t_m)
    real(8), intent (in) :: t_s
    real(8), intent (in) :: x
    real(8), intent (in) :: l
    real(8), intent (in) :: t_m
    real(8) :: t_2
    real(8) :: tmp
    t_2 = 2.0d0 * (t_m ** 2.0d0)
    if (t_m <= 1.55d-159) then
        tmp = 1.0d0 / (1.0d0 + ((0.5d0 / (x ** 2.0d0)) + ((1.0d0 / x) + (0.5d0 * (1.0d0 / (x ** 3.0d0))))))
    else if (t_m <= 6d-9) then
        tmp = (sqrt(2.0d0) * t_m) / sqrt((((2.0d0 * ((t_m ** 2.0d0) / x)) + (t_2 + ((l ** 2.0d0) / x))) - ((-1.0d0) * ((t_2 + (l ** 2.0d0)) / x))))
    else
        tmp = ((1.0d0 + x) / (x + (-1.0d0))) ** (-0.5d0)
    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 x, double l, double t_m) {
	double t_2 = 2.0 * Math.pow(t_m, 2.0);
	double tmp;
	if (t_m <= 1.55e-159) {
		tmp = 1.0 / (1.0 + ((0.5 / Math.pow(x, 2.0)) + ((1.0 / x) + (0.5 * (1.0 / Math.pow(x, 3.0))))));
	} else if (t_m <= 6e-9) {
		tmp = (Math.sqrt(2.0) * t_m) / Math.sqrt((((2.0 * (Math.pow(t_m, 2.0) / x)) + (t_2 + (Math.pow(l, 2.0) / x))) - (-1.0 * ((t_2 + Math.pow(l, 2.0)) / x))));
	} else {
		tmp = Math.pow(((1.0 + x) / (x + -1.0)), -0.5);
	}
	return t_s * tmp;
}
t\_m = math.fabs(t)
t\_s = math.copysign(1.0, t)
def code(t_s, x, l, t_m):
	t_2 = 2.0 * math.pow(t_m, 2.0)
	tmp = 0
	if t_m <= 1.55e-159:
		tmp = 1.0 / (1.0 + ((0.5 / math.pow(x, 2.0)) + ((1.0 / x) + (0.5 * (1.0 / math.pow(x, 3.0))))))
	elif t_m <= 6e-9:
		tmp = (math.sqrt(2.0) * t_m) / math.sqrt((((2.0 * (math.pow(t_m, 2.0) / x)) + (t_2 + (math.pow(l, 2.0) / x))) - (-1.0 * ((t_2 + math.pow(l, 2.0)) / x))))
	else:
		tmp = math.pow(((1.0 + x) / (x + -1.0)), -0.5)
	return t_s * tmp
t\_m = abs(t)
t\_s = copysign(1.0, t)
function code(t_s, x, l, t_m)
	t_2 = Float64(2.0 * (t_m ^ 2.0))
	tmp = 0.0
	if (t_m <= 1.55e-159)
		tmp = Float64(1.0 / Float64(1.0 + Float64(Float64(0.5 / (x ^ 2.0)) + Float64(Float64(1.0 / x) + Float64(0.5 * Float64(1.0 / (x ^ 3.0)))))));
	elseif (t_m <= 6e-9)
		tmp = Float64(Float64(sqrt(2.0) * t_m) / sqrt(Float64(Float64(Float64(2.0 * Float64((t_m ^ 2.0) / x)) + Float64(t_2 + Float64((l ^ 2.0) / x))) - Float64(-1.0 * Float64(Float64(t_2 + (l ^ 2.0)) / x)))));
	else
		tmp = Float64(Float64(1.0 + x) / Float64(x + -1.0)) ^ -0.5;
	end
	return Float64(t_s * tmp)
end
t\_m = abs(t);
t\_s = sign(t) * abs(1.0);
function tmp_2 = code(t_s, x, l, t_m)
	t_2 = 2.0 * (t_m ^ 2.0);
	tmp = 0.0;
	if (t_m <= 1.55e-159)
		tmp = 1.0 / (1.0 + ((0.5 / (x ^ 2.0)) + ((1.0 / x) + (0.5 * (1.0 / (x ^ 3.0))))));
	elseif (t_m <= 6e-9)
		tmp = (sqrt(2.0) * t_m) / sqrt((((2.0 * ((t_m ^ 2.0) / x)) + (t_2 + ((l ^ 2.0) / x))) - (-1.0 * ((t_2 + (l ^ 2.0)) / x))));
	else
		tmp = ((1.0 + x) / (x + -1.0)) ^ -0.5;
	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_, x_, l_, t$95$m_] := Block[{t$95$2 = N[(2.0 * N[Power[t$95$m, 2.0], $MachinePrecision]), $MachinePrecision]}, N[(t$95$s * If[LessEqual[t$95$m, 1.55e-159], N[(1.0 / N[(1.0 + N[(N[(0.5 / N[Power[x, 2.0], $MachinePrecision]), $MachinePrecision] + N[(N[(1.0 / x), $MachinePrecision] + N[(0.5 * N[(1.0 / N[Power[x, 3.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], If[LessEqual[t$95$m, 6e-9], N[(N[(N[Sqrt[2.0], $MachinePrecision] * t$95$m), $MachinePrecision] / N[Sqrt[N[(N[(N[(2.0 * N[(N[Power[t$95$m, 2.0], $MachinePrecision] / x), $MachinePrecision]), $MachinePrecision] + N[(t$95$2 + N[(N[Power[l, 2.0], $MachinePrecision] / x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] - N[(-1.0 * N[(N[(t$95$2 + N[Power[l, 2.0], $MachinePrecision]), $MachinePrecision] / x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision], N[Power[N[(N[(1.0 + x), $MachinePrecision] / N[(x + -1.0), $MachinePrecision]), $MachinePrecision], -0.5], $MachinePrecision]]]), $MachinePrecision]]
\begin{array}{l}
t\_m = \left|t\right|
\\
t\_s = \mathsf{copysign}\left(1, t\right)

\\
\begin{array}{l}
t_2 := 2 \cdot {t\_m}^{2}\\
t\_s \cdot \begin{array}{l}
\mathbf{if}\;t\_m \leq 1.55 \cdot 10^{-159}:\\
\;\;\;\;\frac{1}{1 + \left(\frac{0.5}{{x}^{2}} + \left(\frac{1}{x} + 0.5 \cdot \frac{1}{{x}^{3}}\right)\right)}\\

\mathbf{elif}\;t\_m \leq 6 \cdot 10^{-9}:\\
\;\;\;\;\frac{\sqrt{2} \cdot t\_m}{\sqrt{\left(2 \cdot \frac{{t\_m}^{2}}{x} + \left(t\_2 + \frac{{\ell}^{2}}{x}\right)\right) - -1 \cdot \frac{t\_2 + {\ell}^{2}}{x}}}\\

\mathbf{else}:\\
\;\;\;\;{\left(\frac{1 + x}{x + -1}\right)}^{-0.5}\\


\end{array}
\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if t < 1.55e-159

    1. Initial program 31.2%

      \[\frac{\sqrt{2} \cdot t}{\sqrt{\frac{x + 1}{x - 1} \cdot \left(\ell \cdot \ell + 2 \cdot \left(t \cdot t\right)\right) - \ell \cdot \ell}} \]
    2. Simplified28.1%

      \[\leadsto \color{blue}{\sqrt{2} \cdot \frac{t}{\sqrt{\mathsf{fma}\left(x + 1, \frac{\mathsf{fma}\left(2, t \cdot t, \ell \cdot \ell\right)}{x + -1}, -\ell \cdot \ell\right)}}} \]
    3. Add Preprocessing
    4. Taylor expanded in t around inf 8.1%

      \[\leadsto \sqrt{2} \cdot \frac{t}{\color{blue}{\left(t \cdot \sqrt{2}\right) \cdot \sqrt{\frac{1 + x}{x - 1}}}} \]
    5. Taylor expanded in t around 0 8.1%

      \[\leadsto \color{blue}{\sqrt{\frac{x - 1}{1 + x}}} \]
    6. Step-by-step derivation
      1. clear-num8.1%

        \[\leadsto \sqrt{\color{blue}{\frac{1}{\frac{1 + x}{x - 1}}}} \]
      2. sub-neg8.1%

        \[\leadsto \sqrt{\frac{1}{\frac{1 + x}{\color{blue}{x + \left(-1\right)}}}} \]
      3. metadata-eval8.1%

        \[\leadsto \sqrt{\frac{1}{\frac{1 + x}{x + \color{blue}{-1}}}} \]
      4. sqrt-div8.1%

        \[\leadsto \color{blue}{\frac{\sqrt{1}}{\sqrt{\frac{1 + x}{x + -1}}}} \]
      5. metadata-eval8.1%

        \[\leadsto \frac{\color{blue}{1}}{\sqrt{\frac{1 + x}{x + -1}}} \]
      6. +-commutative8.1%

        \[\leadsto \frac{1}{\sqrt{\frac{\color{blue}{x + 1}}{x + -1}}} \]
    7. Applied egg-rr8.1%

      \[\leadsto \color{blue}{\frac{1}{\sqrt{\frac{x + 1}{x + -1}}}} \]
    8. Taylor expanded in x around inf 8.1%

      \[\leadsto \frac{1}{\color{blue}{1 + \left(\frac{0.5}{{x}^{2}} + \left(\frac{1}{x} + 0.5 \cdot \frac{1}{{x}^{3}}\right)\right)}} \]

    if 1.55e-159 < t < 5.99999999999999996e-9

    1. Initial program 43.3%

      \[\frac{\sqrt{2} \cdot t}{\sqrt{\frac{x + 1}{x - 1} \cdot \left(\ell \cdot \ell + 2 \cdot \left(t \cdot t\right)\right) - \ell \cdot \ell}} \]
    2. Add Preprocessing
    3. Taylor expanded in x around inf 73.7%

      \[\leadsto \frac{\sqrt{2} \cdot t}{\sqrt{\color{blue}{\left(2 \cdot \frac{{t}^{2}}{x} + \left(2 \cdot {t}^{2} + \frac{{\ell}^{2}}{x}\right)\right) - -1 \cdot \frac{2 \cdot {t}^{2} + {\ell}^{2}}{x}}}} \]

    if 5.99999999999999996e-9 < t

    1. Initial program 41.9%

      \[\frac{\sqrt{2} \cdot t}{\sqrt{\frac{x + 1}{x - 1} \cdot \left(\ell \cdot \ell + 2 \cdot \left(t \cdot t\right)\right) - \ell \cdot \ell}} \]
    2. Simplified41.8%

      \[\leadsto \color{blue}{\sqrt{2} \cdot \frac{t}{\sqrt{\mathsf{fma}\left(x + 1, \frac{\mathsf{fma}\left(2, t \cdot t, \ell \cdot \ell\right)}{x + -1}, -\ell \cdot \ell\right)}}} \]
    3. Add Preprocessing
    4. Taylor expanded in t around inf 91.4%

      \[\leadsto \sqrt{2} \cdot \frac{t}{\color{blue}{\left(t \cdot \sqrt{2}\right) \cdot \sqrt{\frac{1 + x}{x - 1}}}} \]
    5. Taylor expanded in t around 0 91.7%

      \[\leadsto \color{blue}{\sqrt{\frac{x - 1}{1 + x}}} \]
    6. Step-by-step derivation
      1. clear-num91.7%

        \[\leadsto \sqrt{\color{blue}{\frac{1}{\frac{1 + x}{x - 1}}}} \]
      2. sub-neg91.7%

        \[\leadsto \sqrt{\frac{1}{\frac{1 + x}{\color{blue}{x + \left(-1\right)}}}} \]
      3. metadata-eval91.7%

        \[\leadsto \sqrt{\frac{1}{\frac{1 + x}{x + \color{blue}{-1}}}} \]
      4. sqrt-div91.7%

        \[\leadsto \color{blue}{\frac{\sqrt{1}}{\sqrt{\frac{1 + x}{x + -1}}}} \]
      5. metadata-eval91.7%

        \[\leadsto \frac{\color{blue}{1}}{\sqrt{\frac{1 + x}{x + -1}}} \]
      6. +-commutative91.7%

        \[\leadsto \frac{1}{\sqrt{\frac{\color{blue}{x + 1}}{x + -1}}} \]
    7. Applied egg-rr91.7%

      \[\leadsto \color{blue}{\frac{1}{\sqrt{\frac{x + 1}{x + -1}}}} \]
    8. Step-by-step derivation
      1. pow1/291.7%

        \[\leadsto \frac{1}{\color{blue}{{\left(\frac{x + 1}{x + -1}\right)}^{0.5}}} \]
      2. pow-flip91.7%

        \[\leadsto \color{blue}{{\left(\frac{x + 1}{x + -1}\right)}^{\left(-0.5\right)}} \]
      3. +-commutative91.7%

        \[\leadsto {\left(\frac{\color{blue}{1 + x}}{x + -1}\right)}^{\left(-0.5\right)} \]
      4. metadata-eval91.7%

        \[\leadsto {\left(\frac{1 + x}{x + -1}\right)}^{\color{blue}{-0.5}} \]
    9. Applied egg-rr91.7%

      \[\leadsto \color{blue}{{\left(\frac{1 + x}{x + -1}\right)}^{-0.5}} \]
  3. Recombined 3 regimes into one program.
  4. Add Preprocessing

Alternative 4: 84.7% accurate, 0.3× speedup?

\[\begin{array}{l} t\_m = \left|t\right| \\ t\_s = \mathsf{copysign}\left(1, t\right) \\ \begin{array}{l} t_2 := 2 \cdot {t\_m}^{2}\\ t_3 := t\_2 + {\ell}^{2}\\ t_4 := \sqrt{2} \cdot t\_m\\ t\_s \cdot \begin{array}{l} \mathbf{if}\;t\_m \leq 2.9 \cdot 10^{-158}:\\ \;\;\;\;\frac{t\_4}{0.5 \cdot \frac{t\_3 - -1 \cdot t\_3}{t\_m \cdot \left(x \cdot \sqrt{2}\right)} + t\_m \cdot \sqrt{2}}\\ \mathbf{elif}\;t\_m \leq 3.8 \cdot 10^{-8}:\\ \;\;\;\;\frac{t\_4}{\sqrt{\left(2 \cdot \frac{{t\_m}^{2}}{x} + \left(t\_2 + \frac{{\ell}^{2}}{x}\right)\right) - -1 \cdot \frac{t\_3}{x}}}\\ \mathbf{else}:\\ \;\;\;\;{\left(\frac{1 + x}{x + -1}\right)}^{-0.5}\\ \end{array} \end{array} \end{array} \]
t\_m = (fabs.f64 t)
t\_s = (copysign.f64 #s(literal 1 binary64) t)
(FPCore (t_s x l t_m)
 :precision binary64
 (let* ((t_2 (* 2.0 (pow t_m 2.0)))
        (t_3 (+ t_2 (pow l 2.0)))
        (t_4 (* (sqrt 2.0) t_m)))
   (*
    t_s
    (if (<= t_m 2.9e-158)
      (/
       t_4
       (+
        (* 0.5 (/ (- t_3 (* -1.0 t_3)) (* t_m (* x (sqrt 2.0)))))
        (* t_m (sqrt 2.0))))
      (if (<= t_m 3.8e-8)
        (/
         t_4
         (sqrt
          (-
           (+ (* 2.0 (/ (pow t_m 2.0) x)) (+ t_2 (/ (pow l 2.0) x)))
           (* -1.0 (/ t_3 x)))))
        (pow (/ (+ 1.0 x) (+ x -1.0)) -0.5))))))
t\_m = fabs(t);
t\_s = copysign(1.0, t);
double code(double t_s, double x, double l, double t_m) {
	double t_2 = 2.0 * pow(t_m, 2.0);
	double t_3 = t_2 + pow(l, 2.0);
	double t_4 = sqrt(2.0) * t_m;
	double tmp;
	if (t_m <= 2.9e-158) {
		tmp = t_4 / ((0.5 * ((t_3 - (-1.0 * t_3)) / (t_m * (x * sqrt(2.0))))) + (t_m * sqrt(2.0)));
	} else if (t_m <= 3.8e-8) {
		tmp = t_4 / sqrt((((2.0 * (pow(t_m, 2.0) / x)) + (t_2 + (pow(l, 2.0) / x))) - (-1.0 * (t_3 / x))));
	} else {
		tmp = pow(((1.0 + x) / (x + -1.0)), -0.5);
	}
	return t_s * tmp;
}
t\_m = abs(t)
t\_s = copysign(1.0d0, t)
real(8) function code(t_s, x, l, t_m)
    real(8), intent (in) :: t_s
    real(8), intent (in) :: x
    real(8), intent (in) :: l
    real(8), intent (in) :: t_m
    real(8) :: t_2
    real(8) :: t_3
    real(8) :: t_4
    real(8) :: tmp
    t_2 = 2.0d0 * (t_m ** 2.0d0)
    t_3 = t_2 + (l ** 2.0d0)
    t_4 = sqrt(2.0d0) * t_m
    if (t_m <= 2.9d-158) then
        tmp = t_4 / ((0.5d0 * ((t_3 - ((-1.0d0) * t_3)) / (t_m * (x * sqrt(2.0d0))))) + (t_m * sqrt(2.0d0)))
    else if (t_m <= 3.8d-8) then
        tmp = t_4 / sqrt((((2.0d0 * ((t_m ** 2.0d0) / x)) + (t_2 + ((l ** 2.0d0) / x))) - ((-1.0d0) * (t_3 / x))))
    else
        tmp = ((1.0d0 + x) / (x + (-1.0d0))) ** (-0.5d0)
    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 x, double l, double t_m) {
	double t_2 = 2.0 * Math.pow(t_m, 2.0);
	double t_3 = t_2 + Math.pow(l, 2.0);
	double t_4 = Math.sqrt(2.0) * t_m;
	double tmp;
	if (t_m <= 2.9e-158) {
		tmp = t_4 / ((0.5 * ((t_3 - (-1.0 * t_3)) / (t_m * (x * Math.sqrt(2.0))))) + (t_m * Math.sqrt(2.0)));
	} else if (t_m <= 3.8e-8) {
		tmp = t_4 / Math.sqrt((((2.0 * (Math.pow(t_m, 2.0) / x)) + (t_2 + (Math.pow(l, 2.0) / x))) - (-1.0 * (t_3 / x))));
	} else {
		tmp = Math.pow(((1.0 + x) / (x + -1.0)), -0.5);
	}
	return t_s * tmp;
}
t\_m = math.fabs(t)
t\_s = math.copysign(1.0, t)
def code(t_s, x, l, t_m):
	t_2 = 2.0 * math.pow(t_m, 2.0)
	t_3 = t_2 + math.pow(l, 2.0)
	t_4 = math.sqrt(2.0) * t_m
	tmp = 0
	if t_m <= 2.9e-158:
		tmp = t_4 / ((0.5 * ((t_3 - (-1.0 * t_3)) / (t_m * (x * math.sqrt(2.0))))) + (t_m * math.sqrt(2.0)))
	elif t_m <= 3.8e-8:
		tmp = t_4 / math.sqrt((((2.0 * (math.pow(t_m, 2.0) / x)) + (t_2 + (math.pow(l, 2.0) / x))) - (-1.0 * (t_3 / x))))
	else:
		tmp = math.pow(((1.0 + x) / (x + -1.0)), -0.5)
	return t_s * tmp
t\_m = abs(t)
t\_s = copysign(1.0, t)
function code(t_s, x, l, t_m)
	t_2 = Float64(2.0 * (t_m ^ 2.0))
	t_3 = Float64(t_2 + (l ^ 2.0))
	t_4 = Float64(sqrt(2.0) * t_m)
	tmp = 0.0
	if (t_m <= 2.9e-158)
		tmp = Float64(t_4 / Float64(Float64(0.5 * Float64(Float64(t_3 - Float64(-1.0 * t_3)) / Float64(t_m * Float64(x * sqrt(2.0))))) + Float64(t_m * sqrt(2.0))));
	elseif (t_m <= 3.8e-8)
		tmp = Float64(t_4 / sqrt(Float64(Float64(Float64(2.0 * Float64((t_m ^ 2.0) / x)) + Float64(t_2 + Float64((l ^ 2.0) / x))) - Float64(-1.0 * Float64(t_3 / x)))));
	else
		tmp = Float64(Float64(1.0 + x) / Float64(x + -1.0)) ^ -0.5;
	end
	return Float64(t_s * tmp)
end
t\_m = abs(t);
t\_s = sign(t) * abs(1.0);
function tmp_2 = code(t_s, x, l, t_m)
	t_2 = 2.0 * (t_m ^ 2.0);
	t_3 = t_2 + (l ^ 2.0);
	t_4 = sqrt(2.0) * t_m;
	tmp = 0.0;
	if (t_m <= 2.9e-158)
		tmp = t_4 / ((0.5 * ((t_3 - (-1.0 * t_3)) / (t_m * (x * sqrt(2.0))))) + (t_m * sqrt(2.0)));
	elseif (t_m <= 3.8e-8)
		tmp = t_4 / sqrt((((2.0 * ((t_m ^ 2.0) / x)) + (t_2 + ((l ^ 2.0) / x))) - (-1.0 * (t_3 / x))));
	else
		tmp = ((1.0 + x) / (x + -1.0)) ^ -0.5;
	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_, x_, l_, t$95$m_] := Block[{t$95$2 = N[(2.0 * N[Power[t$95$m, 2.0], $MachinePrecision]), $MachinePrecision]}, Block[{t$95$3 = N[(t$95$2 + N[Power[l, 2.0], $MachinePrecision]), $MachinePrecision]}, Block[{t$95$4 = N[(N[Sqrt[2.0], $MachinePrecision] * t$95$m), $MachinePrecision]}, N[(t$95$s * If[LessEqual[t$95$m, 2.9e-158], N[(t$95$4 / N[(N[(0.5 * N[(N[(t$95$3 - N[(-1.0 * t$95$3), $MachinePrecision]), $MachinePrecision] / N[(t$95$m * N[(x * N[Sqrt[2.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(t$95$m * N[Sqrt[2.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], If[LessEqual[t$95$m, 3.8e-8], N[(t$95$4 / N[Sqrt[N[(N[(N[(2.0 * N[(N[Power[t$95$m, 2.0], $MachinePrecision] / x), $MachinePrecision]), $MachinePrecision] + N[(t$95$2 + N[(N[Power[l, 2.0], $MachinePrecision] / x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] - N[(-1.0 * N[(t$95$3 / x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision], N[Power[N[(N[(1.0 + x), $MachinePrecision] / N[(x + -1.0), $MachinePrecision]), $MachinePrecision], -0.5], $MachinePrecision]]]), $MachinePrecision]]]]
\begin{array}{l}
t\_m = \left|t\right|
\\
t\_s = \mathsf{copysign}\left(1, t\right)

\\
\begin{array}{l}
t_2 := 2 \cdot {t\_m}^{2}\\
t_3 := t\_2 + {\ell}^{2}\\
t_4 := \sqrt{2} \cdot t\_m\\
t\_s \cdot \begin{array}{l}
\mathbf{if}\;t\_m \leq 2.9 \cdot 10^{-158}:\\
\;\;\;\;\frac{t\_4}{0.5 \cdot \frac{t\_3 - -1 \cdot t\_3}{t\_m \cdot \left(x \cdot \sqrt{2}\right)} + t\_m \cdot \sqrt{2}}\\

\mathbf{elif}\;t\_m \leq 3.8 \cdot 10^{-8}:\\
\;\;\;\;\frac{t\_4}{\sqrt{\left(2 \cdot \frac{{t\_m}^{2}}{x} + \left(t\_2 + \frac{{\ell}^{2}}{x}\right)\right) - -1 \cdot \frac{t\_3}{x}}}\\

\mathbf{else}:\\
\;\;\;\;{\left(\frac{1 + x}{x + -1}\right)}^{-0.5}\\


\end{array}
\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if t < 2.8999999999999998e-158

    1. Initial program 31.0%

      \[\frac{\sqrt{2} \cdot t}{\sqrt{\frac{x + 1}{x - 1} \cdot \left(\ell \cdot \ell + 2 \cdot \left(t \cdot t\right)\right) - \ell \cdot \ell}} \]
    2. Add Preprocessing
    3. Taylor expanded in x around inf 13.2%

      \[\leadsto \frac{\sqrt{2} \cdot t}{\color{blue}{0.5 \cdot \frac{\left(2 \cdot {t}^{2} + {\ell}^{2}\right) - -1 \cdot \left(2 \cdot {t}^{2} + {\ell}^{2}\right)}{t \cdot \left(x \cdot \sqrt{2}\right)} + t \cdot \sqrt{2}}} \]

    if 2.8999999999999998e-158 < t < 3.80000000000000028e-8

    1. Initial program 44.7%

      \[\frac{\sqrt{2} \cdot t}{\sqrt{\frac{x + 1}{x - 1} \cdot \left(\ell \cdot \ell + 2 \cdot \left(t \cdot t\right)\right) - \ell \cdot \ell}} \]
    2. Add Preprocessing
    3. Taylor expanded in x around inf 72.9%

      \[\leadsto \frac{\sqrt{2} \cdot t}{\sqrt{\color{blue}{\left(2 \cdot \frac{{t}^{2}}{x} + \left(2 \cdot {t}^{2} + \frac{{\ell}^{2}}{x}\right)\right) - -1 \cdot \frac{2 \cdot {t}^{2} + {\ell}^{2}}{x}}}} \]

    if 3.80000000000000028e-8 < t

    1. Initial program 41.9%

      \[\frac{\sqrt{2} \cdot t}{\sqrt{\frac{x + 1}{x - 1} \cdot \left(\ell \cdot \ell + 2 \cdot \left(t \cdot t\right)\right) - \ell \cdot \ell}} \]
    2. Simplified41.8%

      \[\leadsto \color{blue}{\sqrt{2} \cdot \frac{t}{\sqrt{\mathsf{fma}\left(x + 1, \frac{\mathsf{fma}\left(2, t \cdot t, \ell \cdot \ell\right)}{x + -1}, -\ell \cdot \ell\right)}}} \]
    3. Add Preprocessing
    4. Taylor expanded in t around inf 91.4%

      \[\leadsto \sqrt{2} \cdot \frac{t}{\color{blue}{\left(t \cdot \sqrt{2}\right) \cdot \sqrt{\frac{1 + x}{x - 1}}}} \]
    5. Taylor expanded in t around 0 91.7%

      \[\leadsto \color{blue}{\sqrt{\frac{x - 1}{1 + x}}} \]
    6. Step-by-step derivation
      1. clear-num91.7%

        \[\leadsto \sqrt{\color{blue}{\frac{1}{\frac{1 + x}{x - 1}}}} \]
      2. sub-neg91.7%

        \[\leadsto \sqrt{\frac{1}{\frac{1 + x}{\color{blue}{x + \left(-1\right)}}}} \]
      3. metadata-eval91.7%

        \[\leadsto \sqrt{\frac{1}{\frac{1 + x}{x + \color{blue}{-1}}}} \]
      4. sqrt-div91.7%

        \[\leadsto \color{blue}{\frac{\sqrt{1}}{\sqrt{\frac{1 + x}{x + -1}}}} \]
      5. metadata-eval91.7%

        \[\leadsto \frac{\color{blue}{1}}{\sqrt{\frac{1 + x}{x + -1}}} \]
      6. +-commutative91.7%

        \[\leadsto \frac{1}{\sqrt{\frac{\color{blue}{x + 1}}{x + -1}}} \]
    7. Applied egg-rr91.7%

      \[\leadsto \color{blue}{\frac{1}{\sqrt{\frac{x + 1}{x + -1}}}} \]
    8. Step-by-step derivation
      1. pow1/291.7%

        \[\leadsto \frac{1}{\color{blue}{{\left(\frac{x + 1}{x + -1}\right)}^{0.5}}} \]
      2. pow-flip91.7%

        \[\leadsto \color{blue}{{\left(\frac{x + 1}{x + -1}\right)}^{\left(-0.5\right)}} \]
      3. +-commutative91.7%

        \[\leadsto {\left(\frac{\color{blue}{1 + x}}{x + -1}\right)}^{\left(-0.5\right)} \]
      4. metadata-eval91.7%

        \[\leadsto {\left(\frac{1 + x}{x + -1}\right)}^{\color{blue}{-0.5}} \]
    9. Applied egg-rr91.7%

      \[\leadsto \color{blue}{{\left(\frac{1 + x}{x + -1}\right)}^{-0.5}} \]
  3. Recombined 3 regimes into one program.
  4. Add Preprocessing

Alternative 5: 77.5% accurate, 2.1× speedup?

\[\begin{array}{l} t\_m = \left|t\right| \\ t\_s = \mathsf{copysign}\left(1, t\right) \\ t\_s \cdot {\left(\frac{1 + x}{x + -1}\right)}^{-0.5} \end{array} \]
t\_m = (fabs.f64 t)
t\_s = (copysign.f64 #s(literal 1 binary64) t)
(FPCore (t_s x l t_m)
 :precision binary64
 (* t_s (pow (/ (+ 1.0 x) (+ x -1.0)) -0.5)))
t\_m = fabs(t);
t\_s = copysign(1.0, t);
double code(double t_s, double x, double l, double t_m) {
	return t_s * pow(((1.0 + x) / (x + -1.0)), -0.5);
}
t\_m = abs(t)
t\_s = copysign(1.0d0, t)
real(8) function code(t_s, x, l, t_m)
    real(8), intent (in) :: t_s
    real(8), intent (in) :: x
    real(8), intent (in) :: l
    real(8), intent (in) :: t_m
    code = t_s * (((1.0d0 + x) / (x + (-1.0d0))) ** (-0.5d0))
end function
t\_m = Math.abs(t);
t\_s = Math.copySign(1.0, t);
public static double code(double t_s, double x, double l, double t_m) {
	return t_s * Math.pow(((1.0 + x) / (x + -1.0)), -0.5);
}
t\_m = math.fabs(t)
t\_s = math.copysign(1.0, t)
def code(t_s, x, l, t_m):
	return t_s * math.pow(((1.0 + x) / (x + -1.0)), -0.5)
t\_m = abs(t)
t\_s = copysign(1.0, t)
function code(t_s, x, l, t_m)
	return Float64(t_s * (Float64(Float64(1.0 + x) / Float64(x + -1.0)) ^ -0.5))
end
t\_m = abs(t);
t\_s = sign(t) * abs(1.0);
function tmp = code(t_s, x, l, t_m)
	tmp = t_s * (((1.0 + x) / (x + -1.0)) ^ -0.5);
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_, x_, l_, t$95$m_] := N[(t$95$s * N[Power[N[(N[(1.0 + x), $MachinePrecision] / N[(x + -1.0), $MachinePrecision]), $MachinePrecision], -0.5], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
t\_m = \left|t\right|
\\
t\_s = \mathsf{copysign}\left(1, t\right)

\\
t\_s \cdot {\left(\frac{1 + x}{x + -1}\right)}^{-0.5}
\end{array}
Derivation
  1. Initial program 35.7%

    \[\frac{\sqrt{2} \cdot t}{\sqrt{\frac{x + 1}{x - 1} \cdot \left(\ell \cdot \ell + 2 \cdot \left(t \cdot t\right)\right) - \ell \cdot \ell}} \]
  2. Simplified29.9%

    \[\leadsto \color{blue}{\sqrt{2} \cdot \frac{t}{\sqrt{\mathsf{fma}\left(x + 1, \frac{\mathsf{fma}\left(2, t \cdot t, \ell \cdot \ell\right)}{x + -1}, -\ell \cdot \ell\right)}}} \]
  3. Add Preprocessing
  4. Taylor expanded in t around inf 37.9%

    \[\leadsto \sqrt{2} \cdot \frac{t}{\color{blue}{\left(t \cdot \sqrt{2}\right) \cdot \sqrt{\frac{1 + x}{x - 1}}}} \]
  5. Taylor expanded in t around 0 38.0%

    \[\leadsto \color{blue}{\sqrt{\frac{x - 1}{1 + x}}} \]
  6. Step-by-step derivation
    1. clear-num38.0%

      \[\leadsto \sqrt{\color{blue}{\frac{1}{\frac{1 + x}{x - 1}}}} \]
    2. sub-neg38.0%

      \[\leadsto \sqrt{\frac{1}{\frac{1 + x}{\color{blue}{x + \left(-1\right)}}}} \]
    3. metadata-eval38.0%

      \[\leadsto \sqrt{\frac{1}{\frac{1 + x}{x + \color{blue}{-1}}}} \]
    4. sqrt-div38.0%

      \[\leadsto \color{blue}{\frac{\sqrt{1}}{\sqrt{\frac{1 + x}{x + -1}}}} \]
    5. metadata-eval38.0%

      \[\leadsto \frac{\color{blue}{1}}{\sqrt{\frac{1 + x}{x + -1}}} \]
    6. +-commutative38.0%

      \[\leadsto \frac{1}{\sqrt{\frac{\color{blue}{x + 1}}{x + -1}}} \]
  7. Applied egg-rr38.0%

    \[\leadsto \color{blue}{\frac{1}{\sqrt{\frac{x + 1}{x + -1}}}} \]
  8. Step-by-step derivation
    1. pow1/238.0%

      \[\leadsto \frac{1}{\color{blue}{{\left(\frac{x + 1}{x + -1}\right)}^{0.5}}} \]
    2. pow-flip38.0%

      \[\leadsto \color{blue}{{\left(\frac{x + 1}{x + -1}\right)}^{\left(-0.5\right)}} \]
    3. +-commutative38.0%

      \[\leadsto {\left(\frac{\color{blue}{1 + x}}{x + -1}\right)}^{\left(-0.5\right)} \]
    4. metadata-eval38.0%

      \[\leadsto {\left(\frac{1 + x}{x + -1}\right)}^{\color{blue}{-0.5}} \]
  9. Applied egg-rr38.0%

    \[\leadsto \color{blue}{{\left(\frac{1 + x}{x + -1}\right)}^{-0.5}} \]
  10. Add Preprocessing

Alternative 6: 77.4% accurate, 2.1× speedup?

\[\begin{array}{l} t\_m = \left|t\right| \\ t\_s = \mathsf{copysign}\left(1, t\right) \\ t\_s \cdot \sqrt{\frac{x - 1}{1 + x}} \end{array} \]
t\_m = (fabs.f64 t)
t\_s = (copysign.f64 #s(literal 1 binary64) t)
(FPCore (t_s x l t_m)
 :precision binary64
 (* t_s (sqrt (/ (- x 1.0) (+ 1.0 x)))))
t\_m = fabs(t);
t\_s = copysign(1.0, t);
double code(double t_s, double x, double l, double t_m) {
	return t_s * sqrt(((x - 1.0) / (1.0 + x)));
}
t\_m = abs(t)
t\_s = copysign(1.0d0, t)
real(8) function code(t_s, x, l, t_m)
    real(8), intent (in) :: t_s
    real(8), intent (in) :: x
    real(8), intent (in) :: l
    real(8), intent (in) :: t_m
    code = t_s * sqrt(((x - 1.0d0) / (1.0d0 + x)))
end function
t\_m = Math.abs(t);
t\_s = Math.copySign(1.0, t);
public static double code(double t_s, double x, double l, double t_m) {
	return t_s * Math.sqrt(((x - 1.0) / (1.0 + x)));
}
t\_m = math.fabs(t)
t\_s = math.copysign(1.0, t)
def code(t_s, x, l, t_m):
	return t_s * math.sqrt(((x - 1.0) / (1.0 + x)))
t\_m = abs(t)
t\_s = copysign(1.0, t)
function code(t_s, x, l, t_m)
	return Float64(t_s * sqrt(Float64(Float64(x - 1.0) / Float64(1.0 + x))))
end
t\_m = abs(t);
t\_s = sign(t) * abs(1.0);
function tmp = code(t_s, x, l, t_m)
	tmp = t_s * sqrt(((x - 1.0) / (1.0 + x)));
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_, x_, l_, t$95$m_] := N[(t$95$s * N[Sqrt[N[(N[(x - 1.0), $MachinePrecision] / N[(1.0 + x), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
t\_m = \left|t\right|
\\
t\_s = \mathsf{copysign}\left(1, t\right)

\\
t\_s \cdot \sqrt{\frac{x - 1}{1 + x}}
\end{array}
Derivation
  1. Initial program 35.7%

    \[\frac{\sqrt{2} \cdot t}{\sqrt{\frac{x + 1}{x - 1} \cdot \left(\ell \cdot \ell + 2 \cdot \left(t \cdot t\right)\right) - \ell \cdot \ell}} \]
  2. Simplified29.9%

    \[\leadsto \color{blue}{\sqrt{2} \cdot \frac{t}{\sqrt{\mathsf{fma}\left(x + 1, \frac{\mathsf{fma}\left(2, t \cdot t, \ell \cdot \ell\right)}{x + -1}, -\ell \cdot \ell\right)}}} \]
  3. Add Preprocessing
  4. Taylor expanded in t around inf 37.9%

    \[\leadsto \sqrt{2} \cdot \frac{t}{\color{blue}{\left(t \cdot \sqrt{2}\right) \cdot \sqrt{\frac{1 + x}{x - 1}}}} \]
  5. Taylor expanded in t around 0 38.0%

    \[\leadsto \color{blue}{\sqrt{\frac{x - 1}{1 + x}}} \]
  6. Add Preprocessing

Alternative 7: 76.7% accurate, 45.0× speedup?

\[\begin{array}{l} t\_m = \left|t\right| \\ t\_s = \mathsf{copysign}\left(1, t\right) \\ t\_s \cdot \left(1 - \frac{1}{x}\right) \end{array} \]
t\_m = (fabs.f64 t)
t\_s = (copysign.f64 #s(literal 1 binary64) t)
(FPCore (t_s x l t_m) :precision binary64 (* t_s (- 1.0 (/ 1.0 x))))
t\_m = fabs(t);
t\_s = copysign(1.0, t);
double code(double t_s, double x, double l, double t_m) {
	return t_s * (1.0 - (1.0 / x));
}
t\_m = abs(t)
t\_s = copysign(1.0d0, t)
real(8) function code(t_s, x, l, t_m)
    real(8), intent (in) :: t_s
    real(8), intent (in) :: x
    real(8), intent (in) :: l
    real(8), intent (in) :: t_m
    code = t_s * (1.0d0 - (1.0d0 / x))
end function
t\_m = Math.abs(t);
t\_s = Math.copySign(1.0, t);
public static double code(double t_s, double x, double l, double t_m) {
	return t_s * (1.0 - (1.0 / x));
}
t\_m = math.fabs(t)
t\_s = math.copysign(1.0, t)
def code(t_s, x, l, t_m):
	return t_s * (1.0 - (1.0 / x))
t\_m = abs(t)
t\_s = copysign(1.0, t)
function code(t_s, x, l, t_m)
	return Float64(t_s * Float64(1.0 - Float64(1.0 / x)))
end
t\_m = abs(t);
t\_s = sign(t) * abs(1.0);
function tmp = code(t_s, x, l, t_m)
	tmp = t_s * (1.0 - (1.0 / x));
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_, x_, l_, t$95$m_] := N[(t$95$s * N[(1.0 - N[(1.0 / x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
t\_m = \left|t\right|
\\
t\_s = \mathsf{copysign}\left(1, t\right)

\\
t\_s \cdot \left(1 - \frac{1}{x}\right)
\end{array}
Derivation
  1. Initial program 35.7%

    \[\frac{\sqrt{2} \cdot t}{\sqrt{\frac{x + 1}{x - 1} \cdot \left(\ell \cdot \ell + 2 \cdot \left(t \cdot t\right)\right) - \ell \cdot \ell}} \]
  2. Simplified29.9%

    \[\leadsto \color{blue}{\sqrt{2} \cdot \frac{t}{\sqrt{\mathsf{fma}\left(x + 1, \frac{\mathsf{fma}\left(2, t \cdot t, \ell \cdot \ell\right)}{x + -1}, -\ell \cdot \ell\right)}}} \]
  3. Add Preprocessing
  4. Taylor expanded in t around inf 37.9%

    \[\leadsto \sqrt{2} \cdot \frac{t}{\color{blue}{\left(t \cdot \sqrt{2}\right) \cdot \sqrt{\frac{1 + x}{x - 1}}}} \]
  5. Taylor expanded in x around inf 37.5%

    \[\leadsto \color{blue}{1 - \frac{1}{x}} \]
  6. Add Preprocessing

Alternative 8: 76.1% accurate, 225.0× speedup?

\[\begin{array}{l} t\_m = \left|t\right| \\ t\_s = \mathsf{copysign}\left(1, t\right) \\ t\_s \cdot 1 \end{array} \]
t\_m = (fabs.f64 t)
t\_s = (copysign.f64 #s(literal 1 binary64) t)
(FPCore (t_s x l t_m) :precision binary64 (* t_s 1.0))
t\_m = fabs(t);
t\_s = copysign(1.0, t);
double code(double t_s, double x, double l, double t_m) {
	return t_s * 1.0;
}
t\_m = abs(t)
t\_s = copysign(1.0d0, t)
real(8) function code(t_s, x, l, t_m)
    real(8), intent (in) :: t_s
    real(8), intent (in) :: x
    real(8), intent (in) :: l
    real(8), intent (in) :: t_m
    code = t_s * 1.0d0
end function
t\_m = Math.abs(t);
t\_s = Math.copySign(1.0, t);
public static double code(double t_s, double x, double l, double t_m) {
	return t_s * 1.0;
}
t\_m = math.fabs(t)
t\_s = math.copysign(1.0, t)
def code(t_s, x, l, t_m):
	return t_s * 1.0
t\_m = abs(t)
t\_s = copysign(1.0, t)
function code(t_s, x, l, t_m)
	return Float64(t_s * 1.0)
end
t\_m = abs(t);
t\_s = sign(t) * abs(1.0);
function tmp = code(t_s, x, l, t_m)
	tmp = t_s * 1.0;
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_, x_, l_, t$95$m_] := N[(t$95$s * 1.0), $MachinePrecision]
\begin{array}{l}
t\_m = \left|t\right|
\\
t\_s = \mathsf{copysign}\left(1, t\right)

\\
t\_s \cdot 1
\end{array}
Derivation
  1. Initial program 35.7%

    \[\frac{\sqrt{2} \cdot t}{\sqrt{\frac{x + 1}{x - 1} \cdot \left(\ell \cdot \ell + 2 \cdot \left(t \cdot t\right)\right) - \ell \cdot \ell}} \]
  2. Simplified29.9%

    \[\leadsto \color{blue}{\sqrt{2} \cdot \frac{t}{\sqrt{\mathsf{fma}\left(x + 1, \frac{\mathsf{fma}\left(2, t \cdot t, \ell \cdot \ell\right)}{x + -1}, -\ell \cdot \ell\right)}}} \]
  3. Add Preprocessing
  4. Taylor expanded in t around inf 37.9%

    \[\leadsto \sqrt{2} \cdot \frac{t}{\color{blue}{\left(t \cdot \sqrt{2}\right) \cdot \sqrt{\frac{1 + x}{x - 1}}}} \]
  5. Taylor expanded in x around inf 37.4%

    \[\leadsto \color{blue}{1} \]
  6. Add Preprocessing

Reproduce

?
herbie shell --seed 2024077 -o generate:simplify
(FPCore (x l t)
  :name "Toniolo and Linder, Equation (7)"
  :precision binary64
  (/ (* (sqrt 2.0) t) (sqrt (- (* (/ (+ x 1.0) (- x 1.0)) (+ (* l l) (* 2.0 (* t t)))) (* l l)))))