SynthBasics:moogVCF from YampaSynth-0.2

Percentage Accurate: 93.8% → 98.1%
Time: 12.0s
Alternatives: 9
Speedup: 0.7×

Specification

?
\[\begin{array}{l} \\ x + \left(y \cdot z\right) \cdot \left(\tanh \left(\frac{t}{y}\right) - \tanh \left(\frac{x}{y}\right)\right) \end{array} \]
(FPCore (x y z t)
 :precision binary64
 (+ x (* (* y z) (- (tanh (/ t y)) (tanh (/ x y))))))
double code(double x, double y, double z, double t) {
	return x + ((y * z) * (tanh((t / y)) - tanh((x / y))));
}
real(8) function code(x, y, z, t)
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    real(8), intent (in) :: z
    real(8), intent (in) :: t
    code = x + ((y * z) * (tanh((t / y)) - tanh((x / y))))
end function
public static double code(double x, double y, double z, double t) {
	return x + ((y * z) * (Math.tanh((t / y)) - Math.tanh((x / y))));
}
def code(x, y, z, t):
	return x + ((y * z) * (math.tanh((t / y)) - math.tanh((x / y))))
function code(x, y, z, t)
	return Float64(x + Float64(Float64(y * z) * Float64(tanh(Float64(t / y)) - tanh(Float64(x / y)))))
end
function tmp = code(x, y, z, t)
	tmp = x + ((y * z) * (tanh((t / y)) - tanh((x / y))));
end
code[x_, y_, z_, t_] := N[(x + N[(N[(y * z), $MachinePrecision] * N[(N[Tanh[N[(t / y), $MachinePrecision]], $MachinePrecision] - N[Tanh[N[(x / y), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
x + \left(y \cdot z\right) \cdot \left(\tanh \left(\frac{t}{y}\right) - \tanh \left(\frac{x}{y}\right)\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 9 alternatives:

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

Initial Program: 93.8% accurate, 1.0× speedup?

\[\begin{array}{l} \\ x + \left(y \cdot z\right) \cdot \left(\tanh \left(\frac{t}{y}\right) - \tanh \left(\frac{x}{y}\right)\right) \end{array} \]
(FPCore (x y z t)
 :precision binary64
 (+ x (* (* y z) (- (tanh (/ t y)) (tanh (/ x y))))))
double code(double x, double y, double z, double t) {
	return x + ((y * z) * (tanh((t / y)) - tanh((x / y))));
}
real(8) function code(x, y, z, t)
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    real(8), intent (in) :: z
    real(8), intent (in) :: t
    code = x + ((y * z) * (tanh((t / y)) - tanh((x / y))))
end function
public static double code(double x, double y, double z, double t) {
	return x + ((y * z) * (Math.tanh((t / y)) - Math.tanh((x / y))));
}
def code(x, y, z, t):
	return x + ((y * z) * (math.tanh((t / y)) - math.tanh((x / y))))
function code(x, y, z, t)
	return Float64(x + Float64(Float64(y * z) * Float64(tanh(Float64(t / y)) - tanh(Float64(x / y)))))
end
function tmp = code(x, y, z, t)
	tmp = x + ((y * z) * (tanh((t / y)) - tanh((x / y))));
end
code[x_, y_, z_, t_] := N[(x + N[(N[(y * z), $MachinePrecision] * N[(N[Tanh[N[(t / y), $MachinePrecision]], $MachinePrecision] - N[Tanh[N[(x / y), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
x + \left(y \cdot z\right) \cdot \left(\tanh \left(\frac{t}{y}\right) - \tanh \left(\frac{x}{y}\right)\right)
\end{array}

Alternative 1: 98.1% accurate, 0.3× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_1 := x + \left(\tanh \left(\frac{t}{y}\right) - \tanh \left(\frac{x}{y}\right)\right) \cdot \left(z \cdot y\right)\\ \mathbf{if}\;t_1 \leq -\infty \lor \neg \left(t_1 \leq 4 \cdot 10^{+292}\right):\\ \;\;\;\;x + z \cdot \left(t - x\right)\\ \mathbf{else}:\\ \;\;\;\;t_1\\ \end{array} \end{array} \]
(FPCore (x y z t)
 :precision binary64
 (let* ((t_1 (+ x (* (- (tanh (/ t y)) (tanh (/ x y))) (* z y)))))
   (if (or (<= t_1 (- INFINITY)) (not (<= t_1 4e+292)))
     (+ x (* z (- t x)))
     t_1)))
double code(double x, double y, double z, double t) {
	double t_1 = x + ((tanh((t / y)) - tanh((x / y))) * (z * y));
	double tmp;
	if ((t_1 <= -((double) INFINITY)) || !(t_1 <= 4e+292)) {
		tmp = x + (z * (t - x));
	} else {
		tmp = t_1;
	}
	return tmp;
}
public static double code(double x, double y, double z, double t) {
	double t_1 = x + ((Math.tanh((t / y)) - Math.tanh((x / y))) * (z * y));
	double tmp;
	if ((t_1 <= -Double.POSITIVE_INFINITY) || !(t_1 <= 4e+292)) {
		tmp = x + (z * (t - x));
	} else {
		tmp = t_1;
	}
	return tmp;
}
def code(x, y, z, t):
	t_1 = x + ((math.tanh((t / y)) - math.tanh((x / y))) * (z * y))
	tmp = 0
	if (t_1 <= -math.inf) or not (t_1 <= 4e+292):
		tmp = x + (z * (t - x))
	else:
		tmp = t_1
	return tmp
function code(x, y, z, t)
	t_1 = Float64(x + Float64(Float64(tanh(Float64(t / y)) - tanh(Float64(x / y))) * Float64(z * y)))
	tmp = 0.0
	if ((t_1 <= Float64(-Inf)) || !(t_1 <= 4e+292))
		tmp = Float64(x + Float64(z * Float64(t - x)));
	else
		tmp = t_1;
	end
	return tmp
end
function tmp_2 = code(x, y, z, t)
	t_1 = x + ((tanh((t / y)) - tanh((x / y))) * (z * y));
	tmp = 0.0;
	if ((t_1 <= -Inf) || ~((t_1 <= 4e+292)))
		tmp = x + (z * (t - x));
	else
		tmp = t_1;
	end
	tmp_2 = tmp;
end
code[x_, y_, z_, t_] := Block[{t$95$1 = N[(x + N[(N[(N[Tanh[N[(t / y), $MachinePrecision]], $MachinePrecision] - N[Tanh[N[(x / y), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] * N[(z * y), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]}, If[Or[LessEqual[t$95$1, (-Infinity)], N[Not[LessEqual[t$95$1, 4e+292]], $MachinePrecision]], N[(x + N[(z * N[(t - x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], t$95$1]]
\begin{array}{l}

\\
\begin{array}{l}
t_1 := x + \left(\tanh \left(\frac{t}{y}\right) - \tanh \left(\frac{x}{y}\right)\right) \cdot \left(z \cdot y\right)\\
\mathbf{if}\;t_1 \leq -\infty \lor \neg \left(t_1 \leq 4 \cdot 10^{+292}\right):\\
\;\;\;\;x + z \cdot \left(t - x\right)\\

\mathbf{else}:\\
\;\;\;\;t_1\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (+.f64 x (*.f64 (*.f64 y z) (-.f64 (tanh.f64 (/.f64 t y)) (tanh.f64 (/.f64 x y))))) < -inf.0 or 4.0000000000000001e292 < (+.f64 x (*.f64 (*.f64 y z) (-.f64 (tanh.f64 (/.f64 t y)) (tanh.f64 (/.f64 x y)))))

    1. Initial program 38.8%

      \[x + \left(y \cdot z\right) \cdot \left(\tanh \left(\frac{t}{y}\right) - \tanh \left(\frac{x}{y}\right)\right) \]
    2. Taylor expanded in y around inf 91.8%

      \[\leadsto x + \color{blue}{z \cdot \left(t - x\right)} \]

    if -inf.0 < (+.f64 x (*.f64 (*.f64 y z) (-.f64 (tanh.f64 (/.f64 t y)) (tanh.f64 (/.f64 x y))))) < 4.0000000000000001e292

    1. Initial program 99.5%

      \[x + \left(y \cdot z\right) \cdot \left(\tanh \left(\frac{t}{y}\right) - \tanh \left(\frac{x}{y}\right)\right) \]
  3. Recombined 2 regimes into one program.
  4. Final simplification98.4%

    \[\leadsto \begin{array}{l} \mathbf{if}\;x + \left(\tanh \left(\frac{t}{y}\right) - \tanh \left(\frac{x}{y}\right)\right) \cdot \left(z \cdot y\right) \leq -\infty \lor \neg \left(x + \left(\tanh \left(\frac{t}{y}\right) - \tanh \left(\frac{x}{y}\right)\right) \cdot \left(z \cdot y\right) \leq 4 \cdot 10^{+292}\right):\\ \;\;\;\;x + z \cdot \left(t - x\right)\\ \mathbf{else}:\\ \;\;\;\;x + \left(\tanh \left(\frac{t}{y}\right) - \tanh \left(\frac{x}{y}\right)\right) \cdot \left(z \cdot y\right)\\ \end{array} \]

Alternative 2: 97.2% accurate, 0.5× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_1 := \tanh \left(\frac{t}{y}\right)\\ t_2 := \tanh \left(\frac{x}{y}\right)\\ \mathbf{if}\;x + \left(t_1 - t_2\right) \cdot \left(z \cdot y\right) \leq 4 \cdot 10^{+292}:\\ \;\;\;\;x + \left(y \cdot \left(z \cdot t_1\right) - y \cdot \left(z \cdot t_2\right)\right)\\ \mathbf{else}:\\ \;\;\;\;x + z \cdot \left(t - x\right)\\ \end{array} \end{array} \]
(FPCore (x y z t)
 :precision binary64
 (let* ((t_1 (tanh (/ t y))) (t_2 (tanh (/ x y))))
   (if (<= (+ x (* (- t_1 t_2) (* z y))) 4e+292)
     (+ x (- (* y (* z t_1)) (* y (* z t_2))))
     (+ x (* z (- t x))))))
double code(double x, double y, double z, double t) {
	double t_1 = tanh((t / y));
	double t_2 = tanh((x / y));
	double tmp;
	if ((x + ((t_1 - t_2) * (z * y))) <= 4e+292) {
		tmp = x + ((y * (z * t_1)) - (y * (z * t_2)));
	} else {
		tmp = x + (z * (t - x));
	}
	return tmp;
}
real(8) function code(x, y, z, t)
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    real(8), intent (in) :: z
    real(8), intent (in) :: t
    real(8) :: t_1
    real(8) :: t_2
    real(8) :: tmp
    t_1 = tanh((t / y))
    t_2 = tanh((x / y))
    if ((x + ((t_1 - t_2) * (z * y))) <= 4d+292) then
        tmp = x + ((y * (z * t_1)) - (y * (z * t_2)))
    else
        tmp = x + (z * (t - x))
    end if
    code = tmp
end function
public static double code(double x, double y, double z, double t) {
	double t_1 = Math.tanh((t / y));
	double t_2 = Math.tanh((x / y));
	double tmp;
	if ((x + ((t_1 - t_2) * (z * y))) <= 4e+292) {
		tmp = x + ((y * (z * t_1)) - (y * (z * t_2)));
	} else {
		tmp = x + (z * (t - x));
	}
	return tmp;
}
def code(x, y, z, t):
	t_1 = math.tanh((t / y))
	t_2 = math.tanh((x / y))
	tmp = 0
	if (x + ((t_1 - t_2) * (z * y))) <= 4e+292:
		tmp = x + ((y * (z * t_1)) - (y * (z * t_2)))
	else:
		tmp = x + (z * (t - x))
	return tmp
function code(x, y, z, t)
	t_1 = tanh(Float64(t / y))
	t_2 = tanh(Float64(x / y))
	tmp = 0.0
	if (Float64(x + Float64(Float64(t_1 - t_2) * Float64(z * y))) <= 4e+292)
		tmp = Float64(x + Float64(Float64(y * Float64(z * t_1)) - Float64(y * Float64(z * t_2))));
	else
		tmp = Float64(x + Float64(z * Float64(t - x)));
	end
	return tmp
end
function tmp_2 = code(x, y, z, t)
	t_1 = tanh((t / y));
	t_2 = tanh((x / y));
	tmp = 0.0;
	if ((x + ((t_1 - t_2) * (z * y))) <= 4e+292)
		tmp = x + ((y * (z * t_1)) - (y * (z * t_2)));
	else
		tmp = x + (z * (t - x));
	end
	tmp_2 = tmp;
end
code[x_, y_, z_, t_] := Block[{t$95$1 = N[Tanh[N[(t / y), $MachinePrecision]], $MachinePrecision]}, Block[{t$95$2 = N[Tanh[N[(x / y), $MachinePrecision]], $MachinePrecision]}, If[LessEqual[N[(x + N[(N[(t$95$1 - t$95$2), $MachinePrecision] * N[(z * y), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], 4e+292], N[(x + N[(N[(y * N[(z * t$95$1), $MachinePrecision]), $MachinePrecision] - N[(y * N[(z * t$95$2), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(x + N[(z * N[(t - x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]]]
\begin{array}{l}

\\
\begin{array}{l}
t_1 := \tanh \left(\frac{t}{y}\right)\\
t_2 := \tanh \left(\frac{x}{y}\right)\\
\mathbf{if}\;x + \left(t_1 - t_2\right) \cdot \left(z \cdot y\right) \leq 4 \cdot 10^{+292}:\\
\;\;\;\;x + \left(y \cdot \left(z \cdot t_1\right) - y \cdot \left(z \cdot t_2\right)\right)\\

\mathbf{else}:\\
\;\;\;\;x + z \cdot \left(t - x\right)\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (+.f64 x (*.f64 (*.f64 y z) (-.f64 (tanh.f64 (/.f64 t y)) (tanh.f64 (/.f64 x y))))) < 4.0000000000000001e292

    1. Initial program 96.0%

      \[x + \left(y \cdot z\right) \cdot \left(\tanh \left(\frac{t}{y}\right) - \tanh \left(\frac{x}{y}\right)\right) \]
    2. Step-by-step derivation
      1. sub-neg96.0%

        \[\leadsto x + \left(y \cdot z\right) \cdot \color{blue}{\left(\tanh \left(\frac{t}{y}\right) + \left(-\tanh \left(\frac{x}{y}\right)\right)\right)} \]
      2. distribute-lft-in94.2%

        \[\leadsto x + \color{blue}{\left(\left(y \cdot z\right) \cdot \tanh \left(\frac{t}{y}\right) + \left(y \cdot z\right) \cdot \left(-\tanh \left(\frac{x}{y}\right)\right)\right)} \]
    3. Applied egg-rr94.2%

      \[\leadsto x + \color{blue}{\left(\left(y \cdot z\right) \cdot \tanh \left(\frac{t}{y}\right) + \left(y \cdot z\right) \cdot \left(-\tanh \left(\frac{x}{y}\right)\right)\right)} \]
    4. Step-by-step derivation
      1. *-commutative94.2%

        \[\leadsto x + \left(\left(y \cdot z\right) \cdot \tanh \left(\frac{t}{y}\right) + \color{blue}{\left(-\tanh \left(\frac{x}{y}\right)\right) \cdot \left(y \cdot z\right)}\right) \]
      2. add-sqr-sqrt55.5%

        \[\leadsto x + \left(\left(y \cdot z\right) \cdot \tanh \left(\frac{t}{y}\right) + \color{blue}{\left(\sqrt{-\tanh \left(\frac{x}{y}\right)} \cdot \sqrt{-\tanh \left(\frac{x}{y}\right)}\right)} \cdot \left(y \cdot z\right)\right) \]
      3. sqrt-unprod88.2%

        \[\leadsto x + \left(\left(y \cdot z\right) \cdot \tanh \left(\frac{t}{y}\right) + \color{blue}{\sqrt{\left(-\tanh \left(\frac{x}{y}\right)\right) \cdot \left(-\tanh \left(\frac{x}{y}\right)\right)}} \cdot \left(y \cdot z\right)\right) \]
      4. sqr-neg88.2%

        \[\leadsto x + \left(\left(y \cdot z\right) \cdot \tanh \left(\frac{t}{y}\right) + \sqrt{\color{blue}{\tanh \left(\frac{x}{y}\right) \cdot \tanh \left(\frac{x}{y}\right)}} \cdot \left(y \cdot z\right)\right) \]
      5. sqrt-unprod42.9%

        \[\leadsto x + \left(\left(y \cdot z\right) \cdot \tanh \left(\frac{t}{y}\right) + \color{blue}{\left(\sqrt{\tanh \left(\frac{x}{y}\right)} \cdot \sqrt{\tanh \left(\frac{x}{y}\right)}\right)} \cdot \left(y \cdot z\right)\right) \]
      6. add-sqr-sqrt78.7%

        \[\leadsto x + \left(\left(y \cdot z\right) \cdot \tanh \left(\frac{t}{y}\right) + \color{blue}{\tanh \left(\frac{x}{y}\right)} \cdot \left(y \cdot z\right)\right) \]
      7. cancel-sign-sub78.7%

        \[\leadsto x + \color{blue}{\left(\left(y \cdot z\right) \cdot \tanh \left(\frac{t}{y}\right) - \left(-\tanh \left(\frac{x}{y}\right)\right) \cdot \left(y \cdot z\right)\right)} \]
      8. associate-*l*78.3%

        \[\leadsto x + \left(\color{blue}{y \cdot \left(z \cdot \tanh \left(\frac{t}{y}\right)\right)} - \left(-\tanh \left(\frac{x}{y}\right)\right) \cdot \left(y \cdot z\right)\right) \]
      9. *-commutative78.3%

        \[\leadsto x + \left(y \cdot \left(z \cdot \tanh \left(\frac{t}{y}\right)\right) - \color{blue}{\left(y \cdot z\right) \cdot \left(-\tanh \left(\frac{x}{y}\right)\right)}\right) \]
      10. associate-*l*81.7%

        \[\leadsto x + \left(y \cdot \left(z \cdot \tanh \left(\frac{t}{y}\right)\right) - \color{blue}{y \cdot \left(z \cdot \left(-\tanh \left(\frac{x}{y}\right)\right)\right)}\right) \]
      11. add-sqr-sqrt48.1%

        \[\leadsto x + \left(y \cdot \left(z \cdot \tanh \left(\frac{t}{y}\right)\right) - y \cdot \left(z \cdot \color{blue}{\left(\sqrt{-\tanh \left(\frac{x}{y}\right)} \cdot \sqrt{-\tanh \left(\frac{x}{y}\right)}\right)}\right)\right) \]
      12. sqrt-unprod86.3%

        \[\leadsto x + \left(y \cdot \left(z \cdot \tanh \left(\frac{t}{y}\right)\right) - y \cdot \left(z \cdot \color{blue}{\sqrt{\left(-\tanh \left(\frac{x}{y}\right)\right) \cdot \left(-\tanh \left(\frac{x}{y}\right)\right)}}\right)\right) \]
      13. sqr-neg86.3%

        \[\leadsto x + \left(y \cdot \left(z \cdot \tanh \left(\frac{t}{y}\right)\right) - y \cdot \left(z \cdot \sqrt{\color{blue}{\tanh \left(\frac{x}{y}\right) \cdot \tanh \left(\frac{x}{y}\right)}}\right)\right) \]
      14. sqrt-unprod50.9%

        \[\leadsto x + \left(y \cdot \left(z \cdot \tanh \left(\frac{t}{y}\right)\right) - y \cdot \left(z \cdot \color{blue}{\left(\sqrt{\tanh \left(\frac{x}{y}\right)} \cdot \sqrt{\tanh \left(\frac{x}{y}\right)}\right)}\right)\right) \]
      15. add-sqr-sqrt99.1%

        \[\leadsto x + \left(y \cdot \left(z \cdot \tanh \left(\frac{t}{y}\right)\right) - y \cdot \left(z \cdot \color{blue}{\tanh \left(\frac{x}{y}\right)}\right)\right) \]
    5. Applied egg-rr99.1%

      \[\leadsto x + \color{blue}{\left(y \cdot \left(z \cdot \tanh \left(\frac{t}{y}\right)\right) - y \cdot \left(z \cdot \tanh \left(\frac{x}{y}\right)\right)\right)} \]

    if 4.0000000000000001e292 < (+.f64 x (*.f64 (*.f64 y z) (-.f64 (tanh.f64 (/.f64 t y)) (tanh.f64 (/.f64 x y)))))

    1. Initial program 31.7%

      \[x + \left(y \cdot z\right) \cdot \left(\tanh \left(\frac{t}{y}\right) - \tanh \left(\frac{x}{y}\right)\right) \]
    2. Taylor expanded in y around inf 85.3%

      \[\leadsto x + \color{blue}{z \cdot \left(t - x\right)} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification98.1%

    \[\leadsto \begin{array}{l} \mathbf{if}\;x + \left(\tanh \left(\frac{t}{y}\right) - \tanh \left(\frac{x}{y}\right)\right) \cdot \left(z \cdot y\right) \leq 4 \cdot 10^{+292}:\\ \;\;\;\;x + \left(y \cdot \left(z \cdot \tanh \left(\frac{t}{y}\right)\right) - y \cdot \left(z \cdot \tanh \left(\frac{x}{y}\right)\right)\right)\\ \mathbf{else}:\\ \;\;\;\;x + z \cdot \left(t - x\right)\\ \end{array} \]

Alternative 3: 97.8% accurate, 0.7× speedup?

\[\begin{array}{l} \\ \mathsf{fma}\left(z, y \cdot \left(\tanh \left(\frac{t}{y}\right) - \tanh \left(\frac{x}{y}\right)\right), x\right) \end{array} \]
(FPCore (x y z t)
 :precision binary64
 (fma z (* y (- (tanh (/ t y)) (tanh (/ x y)))) x))
double code(double x, double y, double z, double t) {
	return fma(z, (y * (tanh((t / y)) - tanh((x / y)))), x);
}
function code(x, y, z, t)
	return fma(z, Float64(y * Float64(tanh(Float64(t / y)) - tanh(Float64(x / y)))), x)
end
code[x_, y_, z_, t_] := N[(z * N[(y * N[(N[Tanh[N[(t / y), $MachinePrecision]], $MachinePrecision] - N[Tanh[N[(x / y), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + x), $MachinePrecision]
\begin{array}{l}

\\
\mathsf{fma}\left(z, y \cdot \left(\tanh \left(\frac{t}{y}\right) - \tanh \left(\frac{x}{y}\right)\right), x\right)
\end{array}
Derivation
  1. Initial program 90.9%

    \[x + \left(y \cdot z\right) \cdot \left(\tanh \left(\frac{t}{y}\right) - \tanh \left(\frac{x}{y}\right)\right) \]
  2. Step-by-step derivation
    1. +-commutative90.9%

      \[\leadsto \color{blue}{\left(y \cdot z\right) \cdot \left(\tanh \left(\frac{t}{y}\right) - \tanh \left(\frac{x}{y}\right)\right) + x} \]
    2. *-commutative90.9%

      \[\leadsto \color{blue}{\left(z \cdot y\right)} \cdot \left(\tanh \left(\frac{t}{y}\right) - \tanh \left(\frac{x}{y}\right)\right) + x \]
    3. associate-*l*97.7%

      \[\leadsto \color{blue}{z \cdot \left(y \cdot \left(\tanh \left(\frac{t}{y}\right) - \tanh \left(\frac{x}{y}\right)\right)\right)} + x \]
    4. fma-def97.7%

      \[\leadsto \color{blue}{\mathsf{fma}\left(z, y \cdot \left(\tanh \left(\frac{t}{y}\right) - \tanh \left(\frac{x}{y}\right)\right), x\right)} \]
  3. Simplified97.7%

    \[\leadsto \color{blue}{\mathsf{fma}\left(z, y \cdot \left(\tanh \left(\frac{t}{y}\right) - \tanh \left(\frac{x}{y}\right)\right), x\right)} \]
  4. Final simplification97.7%

    \[\leadsto \mathsf{fma}\left(z, y \cdot \left(\tanh \left(\frac{t}{y}\right) - \tanh \left(\frac{x}{y}\right)\right), x\right) \]

Alternative 4: 83.2% accurate, 1.9× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_1 := \tanh \left(\frac{t}{y}\right)\\ \mathbf{if}\;y \leq 0.94:\\ \;\;\;\;x + t_1 \cdot \left(z \cdot y\right)\\ \mathbf{else}:\\ \;\;\;\;x + z \cdot \left(y \cdot t_1 - x\right)\\ \end{array} \end{array} \]
(FPCore (x y z t)
 :precision binary64
 (let* ((t_1 (tanh (/ t y))))
   (if (<= y 0.94) (+ x (* t_1 (* z y))) (+ x (* z (- (* y t_1) x))))))
double code(double x, double y, double z, double t) {
	double t_1 = tanh((t / y));
	double tmp;
	if (y <= 0.94) {
		tmp = x + (t_1 * (z * y));
	} else {
		tmp = x + (z * ((y * t_1) - x));
	}
	return tmp;
}
real(8) function code(x, y, z, t)
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    real(8), intent (in) :: z
    real(8), intent (in) :: t
    real(8) :: t_1
    real(8) :: tmp
    t_1 = tanh((t / y))
    if (y <= 0.94d0) then
        tmp = x + (t_1 * (z * y))
    else
        tmp = x + (z * ((y * t_1) - x))
    end if
    code = tmp
end function
public static double code(double x, double y, double z, double t) {
	double t_1 = Math.tanh((t / y));
	double tmp;
	if (y <= 0.94) {
		tmp = x + (t_1 * (z * y));
	} else {
		tmp = x + (z * ((y * t_1) - x));
	}
	return tmp;
}
def code(x, y, z, t):
	t_1 = math.tanh((t / y))
	tmp = 0
	if y <= 0.94:
		tmp = x + (t_1 * (z * y))
	else:
		tmp = x + (z * ((y * t_1) - x))
	return tmp
function code(x, y, z, t)
	t_1 = tanh(Float64(t / y))
	tmp = 0.0
	if (y <= 0.94)
		tmp = Float64(x + Float64(t_1 * Float64(z * y)));
	else
		tmp = Float64(x + Float64(z * Float64(Float64(y * t_1) - x)));
	end
	return tmp
end
function tmp_2 = code(x, y, z, t)
	t_1 = tanh((t / y));
	tmp = 0.0;
	if (y <= 0.94)
		tmp = x + (t_1 * (z * y));
	else
		tmp = x + (z * ((y * t_1) - x));
	end
	tmp_2 = tmp;
end
code[x_, y_, z_, t_] := Block[{t$95$1 = N[Tanh[N[(t / y), $MachinePrecision]], $MachinePrecision]}, If[LessEqual[y, 0.94], N[(x + N[(t$95$1 * N[(z * y), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(x + N[(z * N[(N[(y * t$95$1), $MachinePrecision] - x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
t_1 := \tanh \left(\frac{t}{y}\right)\\
\mathbf{if}\;y \leq 0.94:\\
\;\;\;\;x + t_1 \cdot \left(z \cdot y\right)\\

\mathbf{else}:\\
\;\;\;\;x + z \cdot \left(y \cdot t_1 - x\right)\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if y < 0.93999999999999995

    1. Initial program 95.0%

      \[x + \left(y \cdot z\right) \cdot \left(\tanh \left(\frac{t}{y}\right) - \tanh \left(\frac{x}{y}\right)\right) \]
    2. Taylor expanded in x around 0 22.2%

      \[\leadsto x + \color{blue}{y \cdot \left(z \cdot \left(\frac{e^{\frac{t}{y}}}{e^{\frac{t}{y}} + \frac{1}{e^{\frac{t}{y}}}} - \frac{1}{e^{\frac{t}{y}} \cdot \left(e^{\frac{t}{y}} + \frac{1}{e^{\frac{t}{y}}}\right)}\right)\right)} \]
    3. Step-by-step derivation
      1. associate-*r*22.1%

        \[\leadsto x + \color{blue}{\left(y \cdot z\right) \cdot \left(\frac{e^{\frac{t}{y}}}{e^{\frac{t}{y}} + \frac{1}{e^{\frac{t}{y}}}} - \frac{1}{e^{\frac{t}{y}} \cdot \left(e^{\frac{t}{y}} + \frac{1}{e^{\frac{t}{y}}}\right)}\right)} \]
      2. associate-/r*22.1%

        \[\leadsto x + \left(y \cdot z\right) \cdot \left(\frac{e^{\frac{t}{y}}}{e^{\frac{t}{y}} + \frac{1}{e^{\frac{t}{y}}}} - \color{blue}{\frac{\frac{1}{e^{\frac{t}{y}}}}{e^{\frac{t}{y}} + \frac{1}{e^{\frac{t}{y}}}}}\right) \]
      3. div-sub22.1%

        \[\leadsto x + \left(y \cdot z\right) \cdot \color{blue}{\frac{e^{\frac{t}{y}} - \frac{1}{e^{\frac{t}{y}}}}{e^{\frac{t}{y}} + \frac{1}{e^{\frac{t}{y}}}}} \]
      4. rec-exp22.1%

        \[\leadsto x + \left(y \cdot z\right) \cdot \frac{e^{\frac{t}{y}} - \color{blue}{e^{-\frac{t}{y}}}}{e^{\frac{t}{y}} + \frac{1}{e^{\frac{t}{y}}}} \]
      5. rec-exp22.1%

        \[\leadsto x + \left(y \cdot z\right) \cdot \frac{e^{\frac{t}{y}} - e^{-\frac{t}{y}}}{e^{\frac{t}{y}} + \color{blue}{e^{-\frac{t}{y}}}} \]
      6. tanh-def-a80.6%

        \[\leadsto x + \left(y \cdot z\right) \cdot \color{blue}{\tanh \left(\frac{t}{y}\right)} \]
    4. Simplified80.6%

      \[\leadsto x + \color{blue}{\left(y \cdot z\right) \cdot \tanh \left(\frac{t}{y}\right)} \]

    if 0.93999999999999995 < y

    1. Initial program 79.4%

      \[x + \left(y \cdot z\right) \cdot \left(\tanh \left(\frac{t}{y}\right) - \tanh \left(\frac{x}{y}\right)\right) \]
    2. Taylor expanded in x around 0 48.9%

      \[\leadsto x + \color{blue}{\left(-1 \cdot \left(x \cdot z\right) + y \cdot \left(z \cdot \left(\frac{e^{\frac{t}{y}}}{e^{\frac{t}{y}} + \frac{1}{e^{\frac{t}{y}}}} - \frac{1}{e^{\frac{t}{y}} \cdot \left(e^{\frac{t}{y}} + \frac{1}{e^{\frac{t}{y}}}\right)}\right)\right)\right)} \]
    3. Step-by-step derivation
      1. +-commutative48.9%

        \[\leadsto x + \color{blue}{\left(y \cdot \left(z \cdot \left(\frac{e^{\frac{t}{y}}}{e^{\frac{t}{y}} + \frac{1}{e^{\frac{t}{y}}}} - \frac{1}{e^{\frac{t}{y}} \cdot \left(e^{\frac{t}{y}} + \frac{1}{e^{\frac{t}{y}}}\right)}\right)\right) + -1 \cdot \left(x \cdot z\right)\right)} \]
    4. Simplified82.7%

      \[\leadsto x + \color{blue}{z \cdot \mathsf{fma}\left(y, \tanh \left(\frac{t}{y}\right), -x\right)} \]
    5. Taylor expanded in y around 0 48.9%

      \[\leadsto x + z \cdot \color{blue}{\left(-1 \cdot x + y \cdot \left(\frac{e^{\frac{t}{y}}}{e^{\frac{t}{y}} + \frac{1}{e^{\frac{t}{y}}}} - \frac{1}{e^{\frac{t}{y}} \cdot \left(e^{\frac{t}{y}} + \frac{1}{e^{\frac{t}{y}}}\right)}\right)\right)} \]
    6. Step-by-step derivation
      1. mul-1-neg48.9%

        \[\leadsto x + z \cdot \left(\color{blue}{\left(-x\right)} + y \cdot \left(\frac{e^{\frac{t}{y}}}{e^{\frac{t}{y}} + \frac{1}{e^{\frac{t}{y}}}} - \frac{1}{e^{\frac{t}{y}} \cdot \left(e^{\frac{t}{y}} + \frac{1}{e^{\frac{t}{y}}}\right)}\right)\right) \]
      2. +-commutative48.9%

        \[\leadsto x + z \cdot \color{blue}{\left(y \cdot \left(\frac{e^{\frac{t}{y}}}{e^{\frac{t}{y}} + \frac{1}{e^{\frac{t}{y}}}} - \frac{1}{e^{\frac{t}{y}} \cdot \left(e^{\frac{t}{y}} + \frac{1}{e^{\frac{t}{y}}}\right)}\right) + \left(-x\right)\right)} \]
      3. fma-def48.9%

        \[\leadsto x + z \cdot \color{blue}{\mathsf{fma}\left(y, \frac{e^{\frac{t}{y}}}{e^{\frac{t}{y}} + \frac{1}{e^{\frac{t}{y}}}} - \frac{1}{e^{\frac{t}{y}} \cdot \left(e^{\frac{t}{y}} + \frac{1}{e^{\frac{t}{y}}}\right)}, -x\right)} \]
    7. Simplified82.7%

      \[\leadsto x + z \cdot \color{blue}{\left(y \cdot \tanh \left(\frac{t}{y}\right) - x\right)} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification81.2%

    \[\leadsto \begin{array}{l} \mathbf{if}\;y \leq 0.94:\\ \;\;\;\;x + \tanh \left(\frac{t}{y}\right) \cdot \left(z \cdot y\right)\\ \mathbf{else}:\\ \;\;\;\;x + z \cdot \left(y \cdot \tanh \left(\frac{t}{y}\right) - x\right)\\ \end{array} \]

Alternative 5: 82.7% accurate, 1.9× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;y \leq 6.2 \cdot 10^{+136}:\\ \;\;\;\;x + \tanh \left(\frac{t}{y}\right) \cdot \left(z \cdot y\right)\\ \mathbf{else}:\\ \;\;\;\;x + z \cdot \left(t - x\right)\\ \end{array} \end{array} \]
(FPCore (x y z t)
 :precision binary64
 (if (<= y 6.2e+136) (+ x (* (tanh (/ t y)) (* z y))) (+ x (* z (- t x)))))
double code(double x, double y, double z, double t) {
	double tmp;
	if (y <= 6.2e+136) {
		tmp = x + (tanh((t / y)) * (z * y));
	} else {
		tmp = x + (z * (t - x));
	}
	return tmp;
}
real(8) function code(x, y, z, t)
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    real(8), intent (in) :: z
    real(8), intent (in) :: t
    real(8) :: tmp
    if (y <= 6.2d+136) then
        tmp = x + (tanh((t / y)) * (z * y))
    else
        tmp = x + (z * (t - x))
    end if
    code = tmp
end function
public static double code(double x, double y, double z, double t) {
	double tmp;
	if (y <= 6.2e+136) {
		tmp = x + (Math.tanh((t / y)) * (z * y));
	} else {
		tmp = x + (z * (t - x));
	}
	return tmp;
}
def code(x, y, z, t):
	tmp = 0
	if y <= 6.2e+136:
		tmp = x + (math.tanh((t / y)) * (z * y))
	else:
		tmp = x + (z * (t - x))
	return tmp
function code(x, y, z, t)
	tmp = 0.0
	if (y <= 6.2e+136)
		tmp = Float64(x + Float64(tanh(Float64(t / y)) * Float64(z * y)));
	else
		tmp = Float64(x + Float64(z * Float64(t - x)));
	end
	return tmp
end
function tmp_2 = code(x, y, z, t)
	tmp = 0.0;
	if (y <= 6.2e+136)
		tmp = x + (tanh((t / y)) * (z * y));
	else
		tmp = x + (z * (t - x));
	end
	tmp_2 = tmp;
end
code[x_, y_, z_, t_] := If[LessEqual[y, 6.2e+136], N[(x + N[(N[Tanh[N[(t / y), $MachinePrecision]], $MachinePrecision] * N[(z * y), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(x + N[(z * N[(t - x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;y \leq 6.2 \cdot 10^{+136}:\\
\;\;\;\;x + \tanh \left(\frac{t}{y}\right) \cdot \left(z \cdot y\right)\\

\mathbf{else}:\\
\;\;\;\;x + z \cdot \left(t - x\right)\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if y < 6.19999999999999967e136

    1. Initial program 94.6%

      \[x + \left(y \cdot z\right) \cdot \left(\tanh \left(\frac{t}{y}\right) - \tanh \left(\frac{x}{y}\right)\right) \]
    2. Taylor expanded in x around 0 23.2%

      \[\leadsto x + \color{blue}{y \cdot \left(z \cdot \left(\frac{e^{\frac{t}{y}}}{e^{\frac{t}{y}} + \frac{1}{e^{\frac{t}{y}}}} - \frac{1}{e^{\frac{t}{y}} \cdot \left(e^{\frac{t}{y}} + \frac{1}{e^{\frac{t}{y}}}\right)}\right)\right)} \]
    3. Step-by-step derivation
      1. associate-*r*23.1%

        \[\leadsto x + \color{blue}{\left(y \cdot z\right) \cdot \left(\frac{e^{\frac{t}{y}}}{e^{\frac{t}{y}} + \frac{1}{e^{\frac{t}{y}}}} - \frac{1}{e^{\frac{t}{y}} \cdot \left(e^{\frac{t}{y}} + \frac{1}{e^{\frac{t}{y}}}\right)}\right)} \]
      2. associate-/r*23.1%

        \[\leadsto x + \left(y \cdot z\right) \cdot \left(\frac{e^{\frac{t}{y}}}{e^{\frac{t}{y}} + \frac{1}{e^{\frac{t}{y}}}} - \color{blue}{\frac{\frac{1}{e^{\frac{t}{y}}}}{e^{\frac{t}{y}} + \frac{1}{e^{\frac{t}{y}}}}}\right) \]
      3. div-sub23.1%

        \[\leadsto x + \left(y \cdot z\right) \cdot \color{blue}{\frac{e^{\frac{t}{y}} - \frac{1}{e^{\frac{t}{y}}}}{e^{\frac{t}{y}} + \frac{1}{e^{\frac{t}{y}}}}} \]
      4. rec-exp23.1%

        \[\leadsto x + \left(y \cdot z\right) \cdot \frac{e^{\frac{t}{y}} - \color{blue}{e^{-\frac{t}{y}}}}{e^{\frac{t}{y}} + \frac{1}{e^{\frac{t}{y}}}} \]
      5. rec-exp23.1%

        \[\leadsto x + \left(y \cdot z\right) \cdot \frac{e^{\frac{t}{y}} - e^{-\frac{t}{y}}}{e^{\frac{t}{y}} + \color{blue}{e^{-\frac{t}{y}}}} \]
      6. tanh-def-a80.3%

        \[\leadsto x + \left(y \cdot z\right) \cdot \color{blue}{\tanh \left(\frac{t}{y}\right)} \]
    4. Simplified80.3%

      \[\leadsto x + \color{blue}{\left(y \cdot z\right) \cdot \tanh \left(\frac{t}{y}\right)} \]

    if 6.19999999999999967e136 < y

    1. Initial program 71.6%

      \[x + \left(y \cdot z\right) \cdot \left(\tanh \left(\frac{t}{y}\right) - \tanh \left(\frac{x}{y}\right)\right) \]
    2. Taylor expanded in y around inf 84.5%

      \[\leadsto x + \color{blue}{z \cdot \left(t - x\right)} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification80.9%

    \[\leadsto \begin{array}{l} \mathbf{if}\;y \leq 6.2 \cdot 10^{+136}:\\ \;\;\;\;x + \tanh \left(\frac{t}{y}\right) \cdot \left(z \cdot y\right)\\ \mathbf{else}:\\ \;\;\;\;x + z \cdot \left(t - x\right)\\ \end{array} \]

Alternative 6: 66.1% accurate, 19.0× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;y \leq 8.5 \cdot 10^{+29}:\\ \;\;\;\;x\\ \mathbf{elif}\;y \leq 2.8 \cdot 10^{+183} \lor \neg \left(y \leq 1.35 \cdot 10^{+207}\right):\\ \;\;\;\;x + z \cdot t\\ \mathbf{else}:\\ \;\;\;\;x \cdot \left(1 - z\right)\\ \end{array} \end{array} \]
(FPCore (x y z t)
 :precision binary64
 (if (<= y 8.5e+29)
   x
   (if (or (<= y 2.8e+183) (not (<= y 1.35e+207)))
     (+ x (* z t))
     (* x (- 1.0 z)))))
double code(double x, double y, double z, double t) {
	double tmp;
	if (y <= 8.5e+29) {
		tmp = x;
	} else if ((y <= 2.8e+183) || !(y <= 1.35e+207)) {
		tmp = x + (z * t);
	} else {
		tmp = x * (1.0 - z);
	}
	return tmp;
}
real(8) function code(x, y, z, t)
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    real(8), intent (in) :: z
    real(8), intent (in) :: t
    real(8) :: tmp
    if (y <= 8.5d+29) then
        tmp = x
    else if ((y <= 2.8d+183) .or. (.not. (y <= 1.35d+207))) then
        tmp = x + (z * t)
    else
        tmp = x * (1.0d0 - z)
    end if
    code = tmp
end function
public static double code(double x, double y, double z, double t) {
	double tmp;
	if (y <= 8.5e+29) {
		tmp = x;
	} else if ((y <= 2.8e+183) || !(y <= 1.35e+207)) {
		tmp = x + (z * t);
	} else {
		tmp = x * (1.0 - z);
	}
	return tmp;
}
def code(x, y, z, t):
	tmp = 0
	if y <= 8.5e+29:
		tmp = x
	elif (y <= 2.8e+183) or not (y <= 1.35e+207):
		tmp = x + (z * t)
	else:
		tmp = x * (1.0 - z)
	return tmp
function code(x, y, z, t)
	tmp = 0.0
	if (y <= 8.5e+29)
		tmp = x;
	elseif ((y <= 2.8e+183) || !(y <= 1.35e+207))
		tmp = Float64(x + Float64(z * t));
	else
		tmp = Float64(x * Float64(1.0 - z));
	end
	return tmp
end
function tmp_2 = code(x, y, z, t)
	tmp = 0.0;
	if (y <= 8.5e+29)
		tmp = x;
	elseif ((y <= 2.8e+183) || ~((y <= 1.35e+207)))
		tmp = x + (z * t);
	else
		tmp = x * (1.0 - z);
	end
	tmp_2 = tmp;
end
code[x_, y_, z_, t_] := If[LessEqual[y, 8.5e+29], x, If[Or[LessEqual[y, 2.8e+183], N[Not[LessEqual[y, 1.35e+207]], $MachinePrecision]], N[(x + N[(z * t), $MachinePrecision]), $MachinePrecision], N[(x * N[(1.0 - z), $MachinePrecision]), $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;y \leq 8.5 \cdot 10^{+29}:\\
\;\;\;\;x\\

\mathbf{elif}\;y \leq 2.8 \cdot 10^{+183} \lor \neg \left(y \leq 1.35 \cdot 10^{+207}\right):\\
\;\;\;\;x + z \cdot t\\

\mathbf{else}:\\
\;\;\;\;x \cdot \left(1 - z\right)\\


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if y < 8.5000000000000006e29

    1. Initial program 94.6%

      \[x + \left(y \cdot z\right) \cdot \left(\tanh \left(\frac{t}{y}\right) - \tanh \left(\frac{x}{y}\right)\right) \]
    2. Taylor expanded in x around inf 65.7%

      \[\leadsto \color{blue}{x} \]

    if 8.5000000000000006e29 < y < 2.80000000000000018e183 or 1.35000000000000012e207 < y

    1. Initial program 77.6%

      \[x + \left(y \cdot z\right) \cdot \left(\tanh \left(\frac{t}{y}\right) - \tanh \left(\frac{x}{y}\right)\right) \]
    2. Taylor expanded in x around 0 35.6%

      \[\leadsto x + \color{blue}{y \cdot \left(z \cdot \left(\frac{e^{\frac{t}{y}}}{e^{\frac{t}{y}} + \frac{1}{e^{\frac{t}{y}}}} - \frac{1}{e^{\frac{t}{y}} \cdot \left(e^{\frac{t}{y}} + \frac{1}{e^{\frac{t}{y}}}\right)}\right)\right)} \]
    3. Step-by-step derivation
      1. associate-*r*34.8%

        \[\leadsto x + \color{blue}{\left(y \cdot z\right) \cdot \left(\frac{e^{\frac{t}{y}}}{e^{\frac{t}{y}} + \frac{1}{e^{\frac{t}{y}}}} - \frac{1}{e^{\frac{t}{y}} \cdot \left(e^{\frac{t}{y}} + \frac{1}{e^{\frac{t}{y}}}\right)}\right)} \]
      2. associate-/r*34.8%

        \[\leadsto x + \left(y \cdot z\right) \cdot \left(\frac{e^{\frac{t}{y}}}{e^{\frac{t}{y}} + \frac{1}{e^{\frac{t}{y}}}} - \color{blue}{\frac{\frac{1}{e^{\frac{t}{y}}}}{e^{\frac{t}{y}} + \frac{1}{e^{\frac{t}{y}}}}}\right) \]
      3. div-sub34.8%

        \[\leadsto x + \left(y \cdot z\right) \cdot \color{blue}{\frac{e^{\frac{t}{y}} - \frac{1}{e^{\frac{t}{y}}}}{e^{\frac{t}{y}} + \frac{1}{e^{\frac{t}{y}}}}} \]
      4. rec-exp34.8%

        \[\leadsto x + \left(y \cdot z\right) \cdot \frac{e^{\frac{t}{y}} - \color{blue}{e^{-\frac{t}{y}}}}{e^{\frac{t}{y}} + \frac{1}{e^{\frac{t}{y}}}} \]
      5. rec-exp34.8%

        \[\leadsto x + \left(y \cdot z\right) \cdot \frac{e^{\frac{t}{y}} - e^{-\frac{t}{y}}}{e^{\frac{t}{y}} + \color{blue}{e^{-\frac{t}{y}}}} \]
      6. tanh-def-a68.1%

        \[\leadsto x + \left(y \cdot z\right) \cdot \color{blue}{\tanh \left(\frac{t}{y}\right)} \]
    4. Simplified68.1%

      \[\leadsto x + \color{blue}{\left(y \cdot z\right) \cdot \tanh \left(\frac{t}{y}\right)} \]
    5. Taylor expanded in y around inf 66.2%

      \[\leadsto x + \color{blue}{t \cdot z} \]
    6. Step-by-step derivation
      1. *-commutative66.2%

        \[\leadsto x + \color{blue}{z \cdot t} \]
    7. Simplified66.2%

      \[\leadsto x + \color{blue}{z \cdot t} \]

    if 2.80000000000000018e183 < y < 1.35000000000000012e207

    1. Initial program 88.1%

      \[x + \left(y \cdot z\right) \cdot \left(\tanh \left(\frac{t}{y}\right) - \tanh \left(\frac{x}{y}\right)\right) \]
    2. Taylor expanded in x around 0 87.5%

      \[\leadsto x + \color{blue}{\left(-1 \cdot \left(x \cdot z\right) + y \cdot \left(z \cdot \left(\frac{e^{\frac{t}{y}}}{e^{\frac{t}{y}} + \frac{1}{e^{\frac{t}{y}}}} - \frac{1}{e^{\frac{t}{y}} \cdot \left(e^{\frac{t}{y}} + \frac{1}{e^{\frac{t}{y}}}\right)}\right)\right)\right)} \]
    3. Step-by-step derivation
      1. +-commutative87.5%

        \[\leadsto x + \color{blue}{\left(y \cdot \left(z \cdot \left(\frac{e^{\frac{t}{y}}}{e^{\frac{t}{y}} + \frac{1}{e^{\frac{t}{y}}}} - \frac{1}{e^{\frac{t}{y}} \cdot \left(e^{\frac{t}{y}} + \frac{1}{e^{\frac{t}{y}}}\right)}\right)\right) + -1 \cdot \left(x \cdot z\right)\right)} \]
    4. Simplified100.0%

      \[\leadsto x + \color{blue}{z \cdot \mathsf{fma}\left(y, \tanh \left(\frac{t}{y}\right), -x\right)} \]
    5. Taylor expanded in x around inf 75.8%

      \[\leadsto \color{blue}{x \cdot \left(1 + -1 \cdot z\right)} \]
    6. Step-by-step derivation
      1. mul-1-neg75.8%

        \[\leadsto x \cdot \left(1 + \color{blue}{\left(-z\right)}\right) \]
      2. unsub-neg75.8%

        \[\leadsto x \cdot \color{blue}{\left(1 - z\right)} \]
    7. Simplified75.8%

      \[\leadsto \color{blue}{x \cdot \left(1 - z\right)} \]
  3. Recombined 3 regimes into one program.
  4. Final simplification66.1%

    \[\leadsto \begin{array}{l} \mathbf{if}\;y \leq 8.5 \cdot 10^{+29}:\\ \;\;\;\;x\\ \mathbf{elif}\;y \leq 2.8 \cdot 10^{+183} \lor \neg \left(y \leq 1.35 \cdot 10^{+207}\right):\\ \;\;\;\;x + z \cdot t\\ \mathbf{else}:\\ \;\;\;\;x \cdot \left(1 - z\right)\\ \end{array} \]

Alternative 7: 69.3% accurate, 23.5× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;y \leq 5 \cdot 10^{+22}:\\ \;\;\;\;x\\ \mathbf{else}:\\ \;\;\;\;x + z \cdot \left(t - x\right)\\ \end{array} \end{array} \]
(FPCore (x y z t) :precision binary64 (if (<= y 5e+22) x (+ x (* z (- t x)))))
double code(double x, double y, double z, double t) {
	double tmp;
	if (y <= 5e+22) {
		tmp = x;
	} else {
		tmp = x + (z * (t - x));
	}
	return tmp;
}
real(8) function code(x, y, z, t)
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    real(8), intent (in) :: z
    real(8), intent (in) :: t
    real(8) :: tmp
    if (y <= 5d+22) then
        tmp = x
    else
        tmp = x + (z * (t - x))
    end if
    code = tmp
end function
public static double code(double x, double y, double z, double t) {
	double tmp;
	if (y <= 5e+22) {
		tmp = x;
	} else {
		tmp = x + (z * (t - x));
	}
	return tmp;
}
def code(x, y, z, t):
	tmp = 0
	if y <= 5e+22:
		tmp = x
	else:
		tmp = x + (z * (t - x))
	return tmp
function code(x, y, z, t)
	tmp = 0.0
	if (y <= 5e+22)
		tmp = x;
	else
		tmp = Float64(x + Float64(z * Float64(t - x)));
	end
	return tmp
end
function tmp_2 = code(x, y, z, t)
	tmp = 0.0;
	if (y <= 5e+22)
		tmp = x;
	else
		tmp = x + (z * (t - x));
	end
	tmp_2 = tmp;
end
code[x_, y_, z_, t_] := If[LessEqual[y, 5e+22], x, N[(x + N[(z * N[(t - x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;y \leq 5 \cdot 10^{+22}:\\
\;\;\;\;x\\

\mathbf{else}:\\
\;\;\;\;x + z \cdot \left(t - x\right)\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if y < 4.9999999999999996e22

    1. Initial program 94.6%

      \[x + \left(y \cdot z\right) \cdot \left(\tanh \left(\frac{t}{y}\right) - \tanh \left(\frac{x}{y}\right)\right) \]
    2. Taylor expanded in x around inf 66.0%

      \[\leadsto \color{blue}{x} \]

    if 4.9999999999999996e22 < y

    1. Initial program 79.3%

      \[x + \left(y \cdot z\right) \cdot \left(\tanh \left(\frac{t}{y}\right) - \tanh \left(\frac{x}{y}\right)\right) \]
    2. Taylor expanded in y around inf 76.1%

      \[\leadsto x + \color{blue}{z \cdot \left(t - x\right)} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification68.5%

    \[\leadsto \begin{array}{l} \mathbf{if}\;y \leq 5 \cdot 10^{+22}:\\ \;\;\;\;x\\ \mathbf{else}:\\ \;\;\;\;x + z \cdot \left(t - x\right)\\ \end{array} \]

Alternative 8: 64.3% accurate, 30.2× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;y \leq 1.02 \cdot 10^{+58}:\\ \;\;\;\;x\\ \mathbf{else}:\\ \;\;\;\;x \cdot \left(1 - z\right)\\ \end{array} \end{array} \]
(FPCore (x y z t) :precision binary64 (if (<= y 1.02e+58) x (* x (- 1.0 z))))
double code(double x, double y, double z, double t) {
	double tmp;
	if (y <= 1.02e+58) {
		tmp = x;
	} else {
		tmp = x * (1.0 - z);
	}
	return tmp;
}
real(8) function code(x, y, z, t)
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    real(8), intent (in) :: z
    real(8), intent (in) :: t
    real(8) :: tmp
    if (y <= 1.02d+58) then
        tmp = x
    else
        tmp = x * (1.0d0 - z)
    end if
    code = tmp
end function
public static double code(double x, double y, double z, double t) {
	double tmp;
	if (y <= 1.02e+58) {
		tmp = x;
	} else {
		tmp = x * (1.0 - z);
	}
	return tmp;
}
def code(x, y, z, t):
	tmp = 0
	if y <= 1.02e+58:
		tmp = x
	else:
		tmp = x * (1.0 - z)
	return tmp
function code(x, y, z, t)
	tmp = 0.0
	if (y <= 1.02e+58)
		tmp = x;
	else
		tmp = Float64(x * Float64(1.0 - z));
	end
	return tmp
end
function tmp_2 = code(x, y, z, t)
	tmp = 0.0;
	if (y <= 1.02e+58)
		tmp = x;
	else
		tmp = x * (1.0 - z);
	end
	tmp_2 = tmp;
end
code[x_, y_, z_, t_] := If[LessEqual[y, 1.02e+58], x, N[(x * N[(1.0 - z), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;y \leq 1.02 \cdot 10^{+58}:\\
\;\;\;\;x\\

\mathbf{else}:\\
\;\;\;\;x \cdot \left(1 - z\right)\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if y < 1.02000000000000005e58

    1. Initial program 94.3%

      \[x + \left(y \cdot z\right) \cdot \left(\tanh \left(\frac{t}{y}\right) - \tanh \left(\frac{x}{y}\right)\right) \]
    2. Taylor expanded in x around inf 65.5%

      \[\leadsto \color{blue}{x} \]

    if 1.02000000000000005e58 < y

    1. Initial program 78.0%

      \[x + \left(y \cdot z\right) \cdot \left(\tanh \left(\frac{t}{y}\right) - \tanh \left(\frac{x}{y}\right)\right) \]
    2. Taylor expanded in x around 0 52.5%

      \[\leadsto x + \color{blue}{\left(-1 \cdot \left(x \cdot z\right) + y \cdot \left(z \cdot \left(\frac{e^{\frac{t}{y}}}{e^{\frac{t}{y}} + \frac{1}{e^{\frac{t}{y}}}} - \frac{1}{e^{\frac{t}{y}} \cdot \left(e^{\frac{t}{y}} + \frac{1}{e^{\frac{t}{y}}}\right)}\right)\right)\right)} \]
    3. Step-by-step derivation
      1. +-commutative52.5%

        \[\leadsto x + \color{blue}{\left(y \cdot \left(z \cdot \left(\frac{e^{\frac{t}{y}}}{e^{\frac{t}{y}} + \frac{1}{e^{\frac{t}{y}}}} - \frac{1}{e^{\frac{t}{y}} \cdot \left(e^{\frac{t}{y}} + \frac{1}{e^{\frac{t}{y}}}\right)}\right)\right) + -1 \cdot \left(x \cdot z\right)\right)} \]
    4. Simplified82.9%

      \[\leadsto x + \color{blue}{z \cdot \mathsf{fma}\left(y, \tanh \left(\frac{t}{y}\right), -x\right)} \]
    5. Taylor expanded in x around inf 51.0%

      \[\leadsto \color{blue}{x \cdot \left(1 + -1 \cdot z\right)} \]
    6. Step-by-step derivation
      1. mul-1-neg51.0%

        \[\leadsto x \cdot \left(1 + \color{blue}{\left(-z\right)}\right) \]
      2. unsub-neg51.0%

        \[\leadsto x \cdot \color{blue}{\left(1 - z\right)} \]
    7. Simplified51.0%

      \[\leadsto \color{blue}{x \cdot \left(1 - z\right)} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification62.5%

    \[\leadsto \begin{array}{l} \mathbf{if}\;y \leq 1.02 \cdot 10^{+58}:\\ \;\;\;\;x\\ \mathbf{else}:\\ \;\;\;\;x \cdot \left(1 - z\right)\\ \end{array} \]

Alternative 9: 61.1% accurate, 213.0× speedup?

\[\begin{array}{l} \\ x \end{array} \]
(FPCore (x y z t) :precision binary64 x)
double code(double x, double y, double z, double t) {
	return x;
}
real(8) function code(x, y, z, t)
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    real(8), intent (in) :: z
    real(8), intent (in) :: t
    code = x
end function
public static double code(double x, double y, double z, double t) {
	return x;
}
def code(x, y, z, t):
	return x
function code(x, y, z, t)
	return x
end
function tmp = code(x, y, z, t)
	tmp = x;
end
code[x_, y_, z_, t_] := x
\begin{array}{l}

\\
x
\end{array}
Derivation
  1. Initial program 90.9%

    \[x + \left(y \cdot z\right) \cdot \left(\tanh \left(\frac{t}{y}\right) - \tanh \left(\frac{x}{y}\right)\right) \]
  2. Taylor expanded in x around inf 60.1%

    \[\leadsto \color{blue}{x} \]
  3. Final simplification60.1%

    \[\leadsto x \]

Developer target: 97.1% accurate, 1.0× speedup?

\[\begin{array}{l} \\ x + y \cdot \left(z \cdot \left(\tanh \left(\frac{t}{y}\right) - \tanh \left(\frac{x}{y}\right)\right)\right) \end{array} \]
(FPCore (x y z t)
 :precision binary64
 (+ x (* y (* z (- (tanh (/ t y)) (tanh (/ x y)))))))
double code(double x, double y, double z, double t) {
	return x + (y * (z * (tanh((t / y)) - tanh((x / y)))));
}
real(8) function code(x, y, z, t)
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    real(8), intent (in) :: z
    real(8), intent (in) :: t
    code = x + (y * (z * (tanh((t / y)) - tanh((x / y)))))
end function
public static double code(double x, double y, double z, double t) {
	return x + (y * (z * (Math.tanh((t / y)) - Math.tanh((x / y)))));
}
def code(x, y, z, t):
	return x + (y * (z * (math.tanh((t / y)) - math.tanh((x / y)))))
function code(x, y, z, t)
	return Float64(x + Float64(y * Float64(z * Float64(tanh(Float64(t / y)) - tanh(Float64(x / y))))))
end
function tmp = code(x, y, z, t)
	tmp = x + (y * (z * (tanh((t / y)) - tanh((x / y)))));
end
code[x_, y_, z_, t_] := N[(x + N[(y * N[(z * N[(N[Tanh[N[(t / y), $MachinePrecision]], $MachinePrecision] - N[Tanh[N[(x / y), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
x + y \cdot \left(z \cdot \left(\tanh \left(\frac{t}{y}\right) - \tanh \left(\frac{x}{y}\right)\right)\right)
\end{array}

Reproduce

?
herbie shell --seed 2023340 
(FPCore (x y z t)
  :name "SynthBasics:moogVCF from YampaSynth-0.2"
  :precision binary64

  :herbie-target
  (+ x (* y (* z (- (tanh (/ t y)) (tanh (/ x y))))))

  (+ x (* (* y z) (- (tanh (/ t y)) (tanh (/ x y))))))