Toniolo and Linder, Equation (7)

Percentage Accurate: 33.1% → 79.2%
Time: 14.5s
Alternatives: 8
Speedup: 85.0×

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: 33.1% 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: 79.2% accurate, 1.0× speedup?

\[\begin{array}{l} l_m = \left|\ell\right| \\ t\_m = \left|t\right| \\ t\_s = \mathsf{copysign}\left(1, t\right) \\ \begin{array}{l} t_2 := \sqrt{2} \cdot t\_m\\ t\_s \cdot \begin{array}{l} \mathbf{if}\;l\_m \cdot l\_m \leq 10^{+276}:\\ \;\;\;\;\frac{t\_2}{t\_2 \cdot \sqrt{\frac{x + 1}{x + -1}}}\\ \mathbf{else}:\\ \;\;\;\;\frac{t\_2}{l\_m \cdot \sqrt{\frac{2}{x}}}\\ \end{array} \end{array} \end{array} \]
l_m = (fabs.f64 l)
t\_m = (fabs.f64 t)
t\_s = (copysign.f64 #s(literal 1 binary64) t)
(FPCore (t_s x l_m t_m)
 :precision binary64
 (let* ((t_2 (* (sqrt 2.0) t_m)))
   (*
    t_s
    (if (<= (* l_m l_m) 1e+276)
      (/ t_2 (* t_2 (sqrt (/ (+ x 1.0) (+ x -1.0)))))
      (/ t_2 (* l_m (sqrt (/ 2.0 x))))))))
l_m = fabs(l);
t\_m = fabs(t);
t\_s = copysign(1.0, t);
double code(double t_s, double x, double l_m, double t_m) {
	double t_2 = sqrt(2.0) * t_m;
	double tmp;
	if ((l_m * l_m) <= 1e+276) {
		tmp = t_2 / (t_2 * sqrt(((x + 1.0) / (x + -1.0))));
	} else {
		tmp = t_2 / (l_m * sqrt((2.0 / x)));
	}
	return t_s * tmp;
}
l_m = abs(l)
t\_m = abs(t)
t\_s = copysign(1.0d0, t)
real(8) function code(t_s, x, l_m, t_m)
    real(8), intent (in) :: t_s
    real(8), intent (in) :: x
    real(8), intent (in) :: l_m
    real(8), intent (in) :: t_m
    real(8) :: t_2
    real(8) :: tmp
    t_2 = sqrt(2.0d0) * t_m
    if ((l_m * l_m) <= 1d+276) then
        tmp = t_2 / (t_2 * sqrt(((x + 1.0d0) / (x + (-1.0d0)))))
    else
        tmp = t_2 / (l_m * sqrt((2.0d0 / x)))
    end if
    code = t_s * tmp
end function
l_m = Math.abs(l);
t\_m = Math.abs(t);
t\_s = Math.copySign(1.0, t);
public static double code(double t_s, double x, double l_m, double t_m) {
	double t_2 = Math.sqrt(2.0) * t_m;
	double tmp;
	if ((l_m * l_m) <= 1e+276) {
		tmp = t_2 / (t_2 * Math.sqrt(((x + 1.0) / (x + -1.0))));
	} else {
		tmp = t_2 / (l_m * Math.sqrt((2.0 / x)));
	}
	return t_s * tmp;
}
l_m = math.fabs(l)
t\_m = math.fabs(t)
t\_s = math.copysign(1.0, t)
def code(t_s, x, l_m, t_m):
	t_2 = math.sqrt(2.0) * t_m
	tmp = 0
	if (l_m * l_m) <= 1e+276:
		tmp = t_2 / (t_2 * math.sqrt(((x + 1.0) / (x + -1.0))))
	else:
		tmp = t_2 / (l_m * math.sqrt((2.0 / x)))
	return t_s * tmp
l_m = abs(l)
t\_m = abs(t)
t\_s = copysign(1.0, t)
function code(t_s, x, l_m, t_m)
	t_2 = Float64(sqrt(2.0) * t_m)
	tmp = 0.0
	if (Float64(l_m * l_m) <= 1e+276)
		tmp = Float64(t_2 / Float64(t_2 * sqrt(Float64(Float64(x + 1.0) / Float64(x + -1.0)))));
	else
		tmp = Float64(t_2 / Float64(l_m * sqrt(Float64(2.0 / x))));
	end
	return Float64(t_s * tmp)
end
l_m = abs(l);
t\_m = abs(t);
t\_s = sign(t) * abs(1.0);
function tmp_2 = code(t_s, x, l_m, t_m)
	t_2 = sqrt(2.0) * t_m;
	tmp = 0.0;
	if ((l_m * l_m) <= 1e+276)
		tmp = t_2 / (t_2 * sqrt(((x + 1.0) / (x + -1.0))));
	else
		tmp = t_2 / (l_m * sqrt((2.0 / x)));
	end
	tmp_2 = t_s * tmp;
end
l_m = N[Abs[l], $MachinePrecision]
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$95$m_, t$95$m_] := Block[{t$95$2 = N[(N[Sqrt[2.0], $MachinePrecision] * t$95$m), $MachinePrecision]}, N[(t$95$s * If[LessEqual[N[(l$95$m * l$95$m), $MachinePrecision], 1e+276], N[(t$95$2 / N[(t$95$2 * N[Sqrt[N[(N[(x + 1.0), $MachinePrecision] / N[(x + -1.0), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(t$95$2 / N[(l$95$m * N[Sqrt[N[(2.0 / x), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]), $MachinePrecision]]
\begin{array}{l}
l_m = \left|\ell\right|
\\
t\_m = \left|t\right|
\\
t\_s = \mathsf{copysign}\left(1, t\right)

\\
\begin{array}{l}
t_2 := \sqrt{2} \cdot t\_m\\
t\_s \cdot \begin{array}{l}
\mathbf{if}\;l\_m \cdot l\_m \leq 10^{+276}:\\
\;\;\;\;\frac{t\_2}{t\_2 \cdot \sqrt{\frac{x + 1}{x + -1}}}\\

\mathbf{else}:\\
\;\;\;\;\frac{t\_2}{l\_m \cdot \sqrt{\frac{2}{x}}}\\


\end{array}
\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (*.f64 l l) < 1.0000000000000001e276

    1. Initial program 40.1%

      \[\frac{\sqrt{2} \cdot t}{\sqrt{\frac{x + 1}{x - 1} \cdot \left(\ell \cdot \ell + 2 \cdot \left(t \cdot t\right)\right) - \ell \cdot \ell}} \]
    2. Add Preprocessing
    3. Taylor expanded in l around 0

      \[\leadsto \frac{\sqrt{2} \cdot t}{\color{blue}{\left(t \cdot \sqrt{2}\right) \cdot \sqrt{\frac{1 + x}{x - 1}}}} \]
    4. Step-by-step derivation
      1. lower-*.f64N/A

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

        \[\leadsto \frac{\sqrt{2} \cdot t}{\color{blue}{\left(t \cdot \sqrt{2}\right)} \cdot \sqrt{\frac{1 + x}{x - 1}}} \]
      3. lower-sqrt.f64N/A

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

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

        \[\leadsto \frac{\sqrt{2} \cdot t}{\left(t \cdot \sqrt{2}\right) \cdot \sqrt{\color{blue}{\frac{1 + x}{x - 1}}}} \]
      6. lower-+.f64N/A

        \[\leadsto \frac{\sqrt{2} \cdot t}{\left(t \cdot \sqrt{2}\right) \cdot \sqrt{\frac{\color{blue}{1 + x}}{x - 1}}} \]
      7. sub-negN/A

        \[\leadsto \frac{\sqrt{2} \cdot t}{\left(t \cdot \sqrt{2}\right) \cdot \sqrt{\frac{1 + x}{\color{blue}{x + \left(\mathsf{neg}\left(1\right)\right)}}}} \]
      8. metadata-evalN/A

        \[\leadsto \frac{\sqrt{2} \cdot t}{\left(t \cdot \sqrt{2}\right) \cdot \sqrt{\frac{1 + x}{x + \color{blue}{-1}}}} \]
      9. lower-+.f6483.2

        \[\leadsto \frac{\sqrt{2} \cdot t}{\left(t \cdot \sqrt{2}\right) \cdot \sqrt{\frac{1 + x}{\color{blue}{x + -1}}}} \]
    5. Applied rewrites83.2%

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

    if 1.0000000000000001e276 < (*.f64 l l)

    1. Initial program 0.0%

      \[\frac{\sqrt{2} \cdot t}{\sqrt{\frac{x + 1}{x - 1} \cdot \left(\ell \cdot \ell + 2 \cdot \left(t \cdot t\right)\right) - \ell \cdot \ell}} \]
    2. Add Preprocessing
    3. Applied rewrites0.0%

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

      \[\leadsto \frac{\sqrt{2} \cdot t}{\color{blue}{\ell \cdot \sqrt{\frac{{\left(1 + x\right)}^{2}}{{x}^{2} - 1} - 1}}} \]
    5. Step-by-step derivation
      1. lower-*.f64N/A

        \[\leadsto \frac{\sqrt{2} \cdot t}{\color{blue}{\ell \cdot \sqrt{\frac{{\left(1 + x\right)}^{2}}{{x}^{2} - 1} - 1}}} \]
      2. lower-sqrt.f64N/A

        \[\leadsto \frac{\sqrt{2} \cdot t}{\ell \cdot \color{blue}{\sqrt{\frac{{\left(1 + x\right)}^{2}}{{x}^{2} - 1} - 1}}} \]
      3. sub-negN/A

        \[\leadsto \frac{\sqrt{2} \cdot t}{\ell \cdot \sqrt{\color{blue}{\frac{{\left(1 + x\right)}^{2}}{{x}^{2} - 1} + \left(\mathsf{neg}\left(1\right)\right)}}} \]
      4. metadata-evalN/A

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

        \[\leadsto \frac{\sqrt{2} \cdot t}{\ell \cdot \sqrt{\color{blue}{\frac{{\left(1 + x\right)}^{2}}{{x}^{2} - 1} + -1}}} \]
      6. lower-/.f64N/A

        \[\leadsto \frac{\sqrt{2} \cdot t}{\ell \cdot \sqrt{\color{blue}{\frac{{\left(1 + x\right)}^{2}}{{x}^{2} - 1}} + -1}} \]
      7. unpow2N/A

        \[\leadsto \frac{\sqrt{2} \cdot t}{\ell \cdot \sqrt{\frac{\color{blue}{\left(1 + x\right) \cdot \left(1 + x\right)}}{{x}^{2} - 1} + -1}} \]
      8. lower-*.f64N/A

        \[\leadsto \frac{\sqrt{2} \cdot t}{\ell \cdot \sqrt{\frac{\color{blue}{\left(1 + x\right) \cdot \left(1 + x\right)}}{{x}^{2} - 1} + -1}} \]
      9. lower-+.f64N/A

        \[\leadsto \frac{\sqrt{2} \cdot t}{\ell \cdot \sqrt{\frac{\color{blue}{\left(1 + x\right)} \cdot \left(1 + x\right)}{{x}^{2} - 1} + -1}} \]
      10. lower-+.f64N/A

        \[\leadsto \frac{\sqrt{2} \cdot t}{\ell \cdot \sqrt{\frac{\left(1 + x\right) \cdot \color{blue}{\left(1 + x\right)}}{{x}^{2} - 1} + -1}} \]
      11. sub-negN/A

        \[\leadsto \frac{\sqrt{2} \cdot t}{\ell \cdot \sqrt{\frac{\left(1 + x\right) \cdot \left(1 + x\right)}{\color{blue}{{x}^{2} + \left(\mathsf{neg}\left(1\right)\right)}} + -1}} \]
      12. unpow2N/A

        \[\leadsto \frac{\sqrt{2} \cdot t}{\ell \cdot \sqrt{\frac{\left(1 + x\right) \cdot \left(1 + x\right)}{\color{blue}{x \cdot x} + \left(\mathsf{neg}\left(1\right)\right)} + -1}} \]
      13. metadata-evalN/A

        \[\leadsto \frac{\sqrt{2} \cdot t}{\ell \cdot \sqrt{\frac{\left(1 + x\right) \cdot \left(1 + x\right)}{x \cdot x + \color{blue}{-1}} + -1}} \]
      14. lower-fma.f643.2

        \[\leadsto \frac{\sqrt{2} \cdot t}{\ell \cdot \sqrt{\frac{\left(1 + x\right) \cdot \left(1 + x\right)}{\color{blue}{\mathsf{fma}\left(x, x, -1\right)}} + -1}} \]
    6. Applied rewrites3.2%

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

      \[\leadsto \frac{\sqrt{2} \cdot t}{\ell \cdot \sqrt{\frac{2}{x}}} \]
    8. Step-by-step derivation
      1. Applied rewrites74.7%

        \[\leadsto \frac{\sqrt{2} \cdot t}{\ell \cdot \sqrt{\frac{2}{x}}} \]
    9. Recombined 2 regimes into one program.
    10. Final simplification81.7%

      \[\leadsto \begin{array}{l} \mathbf{if}\;\ell \cdot \ell \leq 10^{+276}:\\ \;\;\;\;\frac{\sqrt{2} \cdot t}{\left(\sqrt{2} \cdot t\right) \cdot \sqrt{\frac{x + 1}{x + -1}}}\\ \mathbf{else}:\\ \;\;\;\;\frac{\sqrt{2} \cdot t}{\ell \cdot \sqrt{\frac{2}{x}}}\\ \end{array} \]
    11. Add Preprocessing

    Alternative 2: 79.1% accurate, 1.2× speedup?

    \[\begin{array}{l} l_m = \left|\ell\right| \\ t\_m = \left|t\right| \\ t\_s = \mathsf{copysign}\left(1, t\right) \\ \begin{array}{l} t_2 := \sqrt{2} \cdot t\_m\\ t\_s \cdot \begin{array}{l} \mathbf{if}\;l\_m \cdot l\_m \leq 10^{+276}:\\ \;\;\;\;\frac{t\_2}{t\_m \cdot \sqrt{\frac{\mathsf{fma}\left(x, 2, 2\right)}{x + -1}}}\\ \mathbf{else}:\\ \;\;\;\;\frac{t\_2}{l\_m \cdot \sqrt{\frac{2}{x}}}\\ \end{array} \end{array} \end{array} \]
    l_m = (fabs.f64 l)
    t\_m = (fabs.f64 t)
    t\_s = (copysign.f64 #s(literal 1 binary64) t)
    (FPCore (t_s x l_m t_m)
     :precision binary64
     (let* ((t_2 (* (sqrt 2.0) t_m)))
       (*
        t_s
        (if (<= (* l_m l_m) 1e+276)
          (/ t_2 (* t_m (sqrt (/ (fma x 2.0 2.0) (+ x -1.0)))))
          (/ t_2 (* l_m (sqrt (/ 2.0 x))))))))
    l_m = fabs(l);
    t\_m = fabs(t);
    t\_s = copysign(1.0, t);
    double code(double t_s, double x, double l_m, double t_m) {
    	double t_2 = sqrt(2.0) * t_m;
    	double tmp;
    	if ((l_m * l_m) <= 1e+276) {
    		tmp = t_2 / (t_m * sqrt((fma(x, 2.0, 2.0) / (x + -1.0))));
    	} else {
    		tmp = t_2 / (l_m * sqrt((2.0 / x)));
    	}
    	return t_s * tmp;
    }
    
    l_m = abs(l)
    t\_m = abs(t)
    t\_s = copysign(1.0, t)
    function code(t_s, x, l_m, t_m)
    	t_2 = Float64(sqrt(2.0) * t_m)
    	tmp = 0.0
    	if (Float64(l_m * l_m) <= 1e+276)
    		tmp = Float64(t_2 / Float64(t_m * sqrt(Float64(fma(x, 2.0, 2.0) / Float64(x + -1.0)))));
    	else
    		tmp = Float64(t_2 / Float64(l_m * sqrt(Float64(2.0 / x))));
    	end
    	return Float64(t_s * tmp)
    end
    
    l_m = N[Abs[l], $MachinePrecision]
    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$95$m_, t$95$m_] := Block[{t$95$2 = N[(N[Sqrt[2.0], $MachinePrecision] * t$95$m), $MachinePrecision]}, N[(t$95$s * If[LessEqual[N[(l$95$m * l$95$m), $MachinePrecision], 1e+276], N[(t$95$2 / N[(t$95$m * N[Sqrt[N[(N[(x * 2.0 + 2.0), $MachinePrecision] / N[(x + -1.0), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(t$95$2 / N[(l$95$m * N[Sqrt[N[(2.0 / x), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]), $MachinePrecision]]
    
    \begin{array}{l}
    l_m = \left|\ell\right|
    \\
    t\_m = \left|t\right|
    \\
    t\_s = \mathsf{copysign}\left(1, t\right)
    
    \\
    \begin{array}{l}
    t_2 := \sqrt{2} \cdot t\_m\\
    t\_s \cdot \begin{array}{l}
    \mathbf{if}\;l\_m \cdot l\_m \leq 10^{+276}:\\
    \;\;\;\;\frac{t\_2}{t\_m \cdot \sqrt{\frac{\mathsf{fma}\left(x, 2, 2\right)}{x + -1}}}\\
    
    \mathbf{else}:\\
    \;\;\;\;\frac{t\_2}{l\_m \cdot \sqrt{\frac{2}{x}}}\\
    
    
    \end{array}
    \end{array}
    \end{array}
    
    Derivation
    1. Split input into 2 regimes
    2. if (*.f64 l l) < 1.0000000000000001e276

      1. Initial program 42.0%

        \[\frac{\sqrt{2} \cdot t}{\sqrt{\frac{x + 1}{x - 1} \cdot \left(\ell \cdot \ell + 2 \cdot \left(t \cdot t\right)\right) - \ell \cdot \ell}} \]
      2. Add Preprocessing
      3. Taylor expanded in l around 0

        \[\leadsto \frac{\sqrt{2} \cdot t}{\color{blue}{\left(t \cdot \sqrt{2}\right) \cdot \sqrt{\frac{1 + x}{x - 1}}}} \]
      4. Step-by-step derivation
        1. lower-*.f64N/A

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

          \[\leadsto \frac{\sqrt{2} \cdot t}{\color{blue}{\left(t \cdot \sqrt{2}\right)} \cdot \sqrt{\frac{1 + x}{x - 1}}} \]
        3. lower-sqrt.f64N/A

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

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

          \[\leadsto \frac{\sqrt{2} \cdot t}{\left(t \cdot \sqrt{2}\right) \cdot \sqrt{\color{blue}{\frac{1 + x}{x - 1}}}} \]
        6. lower-+.f64N/A

          \[\leadsto \frac{\sqrt{2} \cdot t}{\left(t \cdot \sqrt{2}\right) \cdot \sqrt{\frac{\color{blue}{1 + x}}{x - 1}}} \]
        7. sub-negN/A

          \[\leadsto \frac{\sqrt{2} \cdot t}{\left(t \cdot \sqrt{2}\right) \cdot \sqrt{\frac{1 + x}{\color{blue}{x + \left(\mathsf{neg}\left(1\right)\right)}}}} \]
        8. metadata-evalN/A

          \[\leadsto \frac{\sqrt{2} \cdot t}{\left(t \cdot \sqrt{2}\right) \cdot \sqrt{\frac{1 + x}{x + \color{blue}{-1}}}} \]
        9. lower-+.f6485.4

          \[\leadsto \frac{\sqrt{2} \cdot t}{\left(t \cdot \sqrt{2}\right) \cdot \sqrt{\frac{1 + x}{\color{blue}{x + -1}}}} \]
      5. Applied rewrites85.4%

        \[\leadsto \frac{\sqrt{2} \cdot t}{\color{blue}{\left(t \cdot \sqrt{2}\right) \cdot \sqrt{\frac{1 + x}{x + -1}}}} \]
      6. Step-by-step derivation
        1. lift-/.f64N/A

          \[\leadsto \color{blue}{\frac{\sqrt{2} \cdot t}{\left(t \cdot \sqrt{2}\right) \cdot \sqrt{\frac{1 + x}{x + -1}}}} \]
        2. clear-numN/A

          \[\leadsto \color{blue}{\frac{1}{\frac{\left(t \cdot \sqrt{2}\right) \cdot \sqrt{\frac{1 + x}{x + -1}}}{\sqrt{2} \cdot t}}} \]
        3. associate-/r/N/A

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

          \[\leadsto \color{blue}{\frac{1}{\left(t \cdot \sqrt{2}\right) \cdot \sqrt{\frac{1 + x}{x + -1}}} \cdot \left(\sqrt{2} \cdot t\right)} \]
      7. Applied rewrites85.3%

        \[\leadsto \color{blue}{\frac{1}{t \cdot \sqrt{2 \cdot \frac{x + 1}{x + -1}}} \cdot \left(\sqrt{2} \cdot t\right)} \]
      8. Applied rewrites85.3%

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

      if 1.0000000000000001e276 < (*.f64 l l)

      1. Initial program 0.6%

        \[\frac{\sqrt{2} \cdot t}{\sqrt{\frac{x + 1}{x - 1} \cdot \left(\ell \cdot \ell + 2 \cdot \left(t \cdot t\right)\right) - \ell \cdot \ell}} \]
      2. Add Preprocessing
      3. Applied rewrites0.7%

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

        \[\leadsto \frac{\sqrt{2} \cdot t}{\color{blue}{\ell \cdot \sqrt{\frac{{\left(1 + x\right)}^{2}}{{x}^{2} - 1} - 1}}} \]
      5. Step-by-step derivation
        1. lower-*.f64N/A

          \[\leadsto \frac{\sqrt{2} \cdot t}{\color{blue}{\ell \cdot \sqrt{\frac{{\left(1 + x\right)}^{2}}{{x}^{2} - 1} - 1}}} \]
        2. lower-sqrt.f64N/A

          \[\leadsto \frac{\sqrt{2} \cdot t}{\ell \cdot \color{blue}{\sqrt{\frac{{\left(1 + x\right)}^{2}}{{x}^{2} - 1} - 1}}} \]
        3. sub-negN/A

          \[\leadsto \frac{\sqrt{2} \cdot t}{\ell \cdot \sqrt{\color{blue}{\frac{{\left(1 + x\right)}^{2}}{{x}^{2} - 1} + \left(\mathsf{neg}\left(1\right)\right)}}} \]
        4. metadata-evalN/A

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

          \[\leadsto \frac{\sqrt{2} \cdot t}{\ell \cdot \sqrt{\color{blue}{\frac{{\left(1 + x\right)}^{2}}{{x}^{2} - 1} + -1}}} \]
        6. lower-/.f64N/A

          \[\leadsto \frac{\sqrt{2} \cdot t}{\ell \cdot \sqrt{\color{blue}{\frac{{\left(1 + x\right)}^{2}}{{x}^{2} - 1}} + -1}} \]
        7. unpow2N/A

          \[\leadsto \frac{\sqrt{2} \cdot t}{\ell \cdot \sqrt{\frac{\color{blue}{\left(1 + x\right) \cdot \left(1 + x\right)}}{{x}^{2} - 1} + -1}} \]
        8. lower-*.f64N/A

          \[\leadsto \frac{\sqrt{2} \cdot t}{\ell \cdot \sqrt{\frac{\color{blue}{\left(1 + x\right) \cdot \left(1 + x\right)}}{{x}^{2} - 1} + -1}} \]
        9. lower-+.f64N/A

          \[\leadsto \frac{\sqrt{2} \cdot t}{\ell \cdot \sqrt{\frac{\color{blue}{\left(1 + x\right)} \cdot \left(1 + x\right)}{{x}^{2} - 1} + -1}} \]
        10. lower-+.f64N/A

          \[\leadsto \frac{\sqrt{2} \cdot t}{\ell \cdot \sqrt{\frac{\left(1 + x\right) \cdot \color{blue}{\left(1 + x\right)}}{{x}^{2} - 1} + -1}} \]
        11. sub-negN/A

          \[\leadsto \frac{\sqrt{2} \cdot t}{\ell \cdot \sqrt{\frac{\left(1 + x\right) \cdot \left(1 + x\right)}{\color{blue}{{x}^{2} + \left(\mathsf{neg}\left(1\right)\right)}} + -1}} \]
        12. unpow2N/A

          \[\leadsto \frac{\sqrt{2} \cdot t}{\ell \cdot \sqrt{\frac{\left(1 + x\right) \cdot \left(1 + x\right)}{\color{blue}{x \cdot x} + \left(\mathsf{neg}\left(1\right)\right)} + -1}} \]
        13. metadata-evalN/A

          \[\leadsto \frac{\sqrt{2} \cdot t}{\ell \cdot \sqrt{\frac{\left(1 + x\right) \cdot \left(1 + x\right)}{x \cdot x + \color{blue}{-1}} + -1}} \]
        14. lower-fma.f643.0

          \[\leadsto \frac{\sqrt{2} \cdot t}{\ell \cdot \sqrt{\frac{\left(1 + x\right) \cdot \left(1 + x\right)}{\color{blue}{\mathsf{fma}\left(x, x, -1\right)}} + -1}} \]
      6. Applied rewrites3.0%

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

        \[\leadsto \frac{\sqrt{2} \cdot t}{\ell \cdot \sqrt{\frac{2}{x}}} \]
      8. Step-by-step derivation
        1. Applied rewrites56.5%

          \[\leadsto \frac{\sqrt{2} \cdot t}{\ell \cdot \sqrt{\frac{2}{x}}} \]
      9. Recombined 2 regimes into one program.
      10. Final simplification79.1%

        \[\leadsto \begin{array}{l} \mathbf{if}\;\ell \cdot \ell \leq 10^{+276}:\\ \;\;\;\;\frac{\sqrt{2} \cdot t}{t \cdot \sqrt{\frac{\mathsf{fma}\left(x, 2, 2\right)}{x + -1}}}\\ \mathbf{else}:\\ \;\;\;\;\frac{\sqrt{2} \cdot t}{\ell \cdot \sqrt{\frac{2}{x}}}\\ \end{array} \]
      11. Add Preprocessing

      Reproduce

      ?
      herbie shell --seed 2024227 
      (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)))))