SynthBasics:moogVCF from YampaSynth-0.2

Percentage Accurate: 93.5% → 96.7%
Time: 10.1s
Alternatives: 7
Speedup: 1.0×

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 7 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: 93.5% 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: 96.7% accurate, 1.0× speedup?

\[\begin{array}{l} y_m = \left|y\right| \\ \begin{array}{l} \mathbf{if}\;y\_m \leq 2.1 \cdot 10^{+178}:\\ \;\;\;\;x + \left(\tanh \left(\frac{t}{y\_m}\right) - \tanh \left(\frac{x}{y\_m}\right)\right) \cdot \left(y\_m \cdot z\right)\\ \mathbf{else}:\\ \;\;\;\;x + z \cdot \left(t - x\right)\\ \end{array} \end{array} \]
y_m = (fabs.f64 y)
(FPCore (x y_m z t)
 :precision binary64
 (if (<= y_m 2.1e+178)
   (+ x (* (- (tanh (/ t y_m)) (tanh (/ x y_m))) (* y_m z)))
   (+ x (* z (- t x)))))
y_m = fabs(y);
double code(double x, double y_m, double z, double t) {
	double tmp;
	if (y_m <= 2.1e+178) {
		tmp = x + ((tanh((t / y_m)) - tanh((x / y_m))) * (y_m * z));
	} else {
		tmp = x + (z * (t - x));
	}
	return tmp;
}
y_m = abs(y)
real(8) function code(x, y_m, z, t)
    real(8), intent (in) :: x
    real(8), intent (in) :: y_m
    real(8), intent (in) :: z
    real(8), intent (in) :: t
    real(8) :: tmp
    if (y_m <= 2.1d+178) then
        tmp = x + ((tanh((t / y_m)) - tanh((x / y_m))) * (y_m * z))
    else
        tmp = x + (z * (t - x))
    end if
    code = tmp
end function
y_m = Math.abs(y);
public static double code(double x, double y_m, double z, double t) {
	double tmp;
	if (y_m <= 2.1e+178) {
		tmp = x + ((Math.tanh((t / y_m)) - Math.tanh((x / y_m))) * (y_m * z));
	} else {
		tmp = x + (z * (t - x));
	}
	return tmp;
}
y_m = math.fabs(y)
def code(x, y_m, z, t):
	tmp = 0
	if y_m <= 2.1e+178:
		tmp = x + ((math.tanh((t / y_m)) - math.tanh((x / y_m))) * (y_m * z))
	else:
		tmp = x + (z * (t - x))
	return tmp
y_m = abs(y)
function code(x, y_m, z, t)
	tmp = 0.0
	if (y_m <= 2.1e+178)
		tmp = Float64(x + Float64(Float64(tanh(Float64(t / y_m)) - tanh(Float64(x / y_m))) * Float64(y_m * z)));
	else
		tmp = Float64(x + Float64(z * Float64(t - x)));
	end
	return tmp
end
y_m = abs(y);
function tmp_2 = code(x, y_m, z, t)
	tmp = 0.0;
	if (y_m <= 2.1e+178)
		tmp = x + ((tanh((t / y_m)) - tanh((x / y_m))) * (y_m * z));
	else
		tmp = x + (z * (t - x));
	end
	tmp_2 = tmp;
end
y_m = N[Abs[y], $MachinePrecision]
code[x_, y$95$m_, z_, t_] := If[LessEqual[y$95$m, 2.1e+178], N[(x + N[(N[(N[Tanh[N[(t / y$95$m), $MachinePrecision]], $MachinePrecision] - N[Tanh[N[(x / y$95$m), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] * N[(y$95$m * z), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(x + N[(z * N[(t - x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
y_m = \left|y\right|

\\
\begin{array}{l}
\mathbf{if}\;y\_m \leq 2.1 \cdot 10^{+178}:\\
\;\;\;\;x + \left(\tanh \left(\frac{t}{y\_m}\right) - \tanh \left(\frac{x}{y\_m}\right)\right) \cdot \left(y\_m \cdot z\right)\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if y < 2.0999999999999999e178

    1. Initial program 95.3%

      \[x + \left(y \cdot z\right) \cdot \left(\tanh \left(\frac{t}{y}\right) - \tanh \left(\frac{x}{y}\right)\right) \]
    2. Add Preprocessing

    if 2.0999999999999999e178 < y

    1. Initial program 79.6%

      \[x + \left(y \cdot z\right) \cdot \left(\tanh \left(\frac{t}{y}\right) - \tanh \left(\frac{x}{y}\right)\right) \]
    2. Add Preprocessing
    3. Taylor expanded in y around inf 96.5%

      \[\leadsto x + \color{blue}{z \cdot \left(t - x\right)} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification95.5%

    \[\leadsto \begin{array}{l} \mathbf{if}\;y \leq 2.1 \cdot 10^{+178}:\\ \;\;\;\;x + \left(\tanh \left(\frac{t}{y}\right) - \tanh \left(\frac{x}{y}\right)\right) \cdot \left(y \cdot z\right)\\ \mathbf{else}:\\ \;\;\;\;x + z \cdot \left(t - x\right)\\ \end{array} \]
  5. Add Preprocessing

Alternative 2: 96.9% accurate, 0.7× speedup?

\[\begin{array}{l} y_m = \left|y\right| \\ \mathsf{fma}\left(y\_m, z \cdot \left(\tanh \left(\frac{t}{y\_m}\right) - \tanh \left(\frac{x}{y\_m}\right)\right), x\right) \end{array} \]
y_m = (fabs.f64 y)
(FPCore (x y_m z t)
 :precision binary64
 (fma y_m (* z (- (tanh (/ t y_m)) (tanh (/ x y_m)))) x))
y_m = fabs(y);
double code(double x, double y_m, double z, double t) {
	return fma(y_m, (z * (tanh((t / y_m)) - tanh((x / y_m)))), x);
}
y_m = abs(y)
function code(x, y_m, z, t)
	return fma(y_m, Float64(z * Float64(tanh(Float64(t / y_m)) - tanh(Float64(x / y_m)))), x)
end
y_m = N[Abs[y], $MachinePrecision]
code[x_, y$95$m_, z_, t_] := N[(y$95$m * N[(z * N[(N[Tanh[N[(t / y$95$m), $MachinePrecision]], $MachinePrecision] - N[Tanh[N[(x / y$95$m), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + x), $MachinePrecision]
\begin{array}{l}
y_m = \left|y\right|

\\
\mathsf{fma}\left(y\_m, z \cdot \left(\tanh \left(\frac{t}{y\_m}\right) - \tanh \left(\frac{x}{y\_m}\right)\right), x\right)
\end{array}
Derivation
  1. Initial program 93.6%

    \[x + \left(y \cdot z\right) \cdot \left(\tanh \left(\frac{t}{y}\right) - \tanh \left(\frac{x}{y}\right)\right) \]
  2. Step-by-step derivation
    1. +-commutative93.6%

      \[\leadsto \color{blue}{\left(y \cdot z\right) \cdot \left(\tanh \left(\frac{t}{y}\right) - \tanh \left(\frac{x}{y}\right)\right) + x} \]
    2. associate-*l*97.4%

      \[\leadsto \color{blue}{y \cdot \left(z \cdot \left(\tanh \left(\frac{t}{y}\right) - \tanh \left(\frac{x}{y}\right)\right)\right)} + x \]
    3. fma-define97.4%

      \[\leadsto \color{blue}{\mathsf{fma}\left(y, z \cdot \left(\tanh \left(\frac{t}{y}\right) - \tanh \left(\frac{x}{y}\right)\right), x\right)} \]
  3. Simplified97.4%

    \[\leadsto \color{blue}{\mathsf{fma}\left(y, z \cdot \left(\tanh \left(\frac{t}{y}\right) - \tanh \left(\frac{x}{y}\right)\right), x\right)} \]
  4. Add Preprocessing
  5. Add Preprocessing

Alternative 3: 85.3% accurate, 1.9× speedup?

\[\begin{array}{l} y_m = \left|y\right| \\ \begin{array}{l} \mathbf{if}\;y\_m \leq 8.2 \cdot 10^{+111}:\\ \;\;\;\;x + \tanh \left(\frac{t}{y\_m}\right) \cdot \left(y\_m \cdot z\right)\\ \mathbf{else}:\\ \;\;\;\;x + z \cdot \left(t - x\right)\\ \end{array} \end{array} \]
y_m = (fabs.f64 y)
(FPCore (x y_m z t)
 :precision binary64
 (if (<= y_m 8.2e+111)
   (+ x (* (tanh (/ t y_m)) (* y_m z)))
   (+ x (* z (- t x)))))
y_m = fabs(y);
double code(double x, double y_m, double z, double t) {
	double tmp;
	if (y_m <= 8.2e+111) {
		tmp = x + (tanh((t / y_m)) * (y_m * z));
	} else {
		tmp = x + (z * (t - x));
	}
	return tmp;
}
y_m = abs(y)
real(8) function code(x, y_m, z, t)
    real(8), intent (in) :: x
    real(8), intent (in) :: y_m
    real(8), intent (in) :: z
    real(8), intent (in) :: t
    real(8) :: tmp
    if (y_m <= 8.2d+111) then
        tmp = x + (tanh((t / y_m)) * (y_m * z))
    else
        tmp = x + (z * (t - x))
    end if
    code = tmp
end function
y_m = Math.abs(y);
public static double code(double x, double y_m, double z, double t) {
	double tmp;
	if (y_m <= 8.2e+111) {
		tmp = x + (Math.tanh((t / y_m)) * (y_m * z));
	} else {
		tmp = x + (z * (t - x));
	}
	return tmp;
}
y_m = math.fabs(y)
def code(x, y_m, z, t):
	tmp = 0
	if y_m <= 8.2e+111:
		tmp = x + (math.tanh((t / y_m)) * (y_m * z))
	else:
		tmp = x + (z * (t - x))
	return tmp
y_m = abs(y)
function code(x, y_m, z, t)
	tmp = 0.0
	if (y_m <= 8.2e+111)
		tmp = Float64(x + Float64(tanh(Float64(t / y_m)) * Float64(y_m * z)));
	else
		tmp = Float64(x + Float64(z * Float64(t - x)));
	end
	return tmp
end
y_m = abs(y);
function tmp_2 = code(x, y_m, z, t)
	tmp = 0.0;
	if (y_m <= 8.2e+111)
		tmp = x + (tanh((t / y_m)) * (y_m * z));
	else
		tmp = x + (z * (t - x));
	end
	tmp_2 = tmp;
end
y_m = N[Abs[y], $MachinePrecision]
code[x_, y$95$m_, z_, t_] := If[LessEqual[y$95$m, 8.2e+111], N[(x + N[(N[Tanh[N[(t / y$95$m), $MachinePrecision]], $MachinePrecision] * N[(y$95$m * z), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(x + N[(z * N[(t - x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
y_m = \left|y\right|

\\
\begin{array}{l}
\mathbf{if}\;y\_m \leq 8.2 \cdot 10^{+111}:\\
\;\;\;\;x + \tanh \left(\frac{t}{y\_m}\right) \cdot \left(y\_m \cdot z\right)\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if y < 8.19999999999999973e111

    1. Initial program 96.4%

      \[x + \left(y \cdot z\right) \cdot \left(\tanh \left(\frac{t}{y}\right) - \tanh \left(\frac{x}{y}\right)\right) \]
    2. Add Preprocessing
    3. Taylor expanded in x around 0 23.0%

      \[\leadsto x + \left(y \cdot z\right) \cdot \color{blue}{\left(\frac{e^{\frac{t}{y}}}{e^{\frac{t}{y}} + \frac{1}{e^{\frac{t}{y}}}} - \frac{1}{e^{\frac{t}{y}} \cdot \left(e^{\frac{t}{y}} + \frac{1}{e^{\frac{t}{y}}}\right)}\right)} \]
    4. Step-by-step derivation
      1. associate-/r*23.0%

        \[\leadsto x + \left(y \cdot z\right) \cdot \left(\frac{e^{\frac{t}{y}}}{e^{\frac{t}{y}} + \frac{1}{e^{\frac{t}{y}}}} - \color{blue}{\frac{\frac{1}{e^{\frac{t}{y}}}}{e^{\frac{t}{y}} + \frac{1}{e^{\frac{t}{y}}}}}\right) \]
      2. rec-exp23.0%

        \[\leadsto x + \left(y \cdot z\right) \cdot \left(\frac{e^{\frac{t}{y}}}{e^{\frac{t}{y}} + \frac{1}{e^{\frac{t}{y}}}} - \frac{\color{blue}{e^{-\frac{t}{y}}}}{e^{\frac{t}{y}} + \frac{1}{e^{\frac{t}{y}}}}\right) \]
      3. div-sub23.0%

        \[\leadsto x + \left(y \cdot z\right) \cdot \color{blue}{\frac{e^{\frac{t}{y}} - e^{-\frac{t}{y}}}{e^{\frac{t}{y}} + \frac{1}{e^{\frac{t}{y}}}}} \]
      4. rec-exp23.0%

        \[\leadsto x + \left(y \cdot z\right) \cdot \frac{e^{\frac{t}{y}} - e^{-\frac{t}{y}}}{e^{\frac{t}{y}} + \color{blue}{e^{-\frac{t}{y}}}} \]
      5. tanh-def-a83.5%

        \[\leadsto x + \left(y \cdot z\right) \cdot \color{blue}{\tanh \left(\frac{t}{y}\right)} \]
    5. Simplified83.5%

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

    if 8.19999999999999973e111 < y

    1. Initial program 79.0%

      \[x + \left(y \cdot z\right) \cdot \left(\tanh \left(\frac{t}{y}\right) - \tanh \left(\frac{x}{y}\right)\right) \]
    2. Add Preprocessing
    3. Taylor expanded in y around inf 95.3%

      \[\leadsto x + \color{blue}{z \cdot \left(t - x\right)} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification85.4%

    \[\leadsto \begin{array}{l} \mathbf{if}\;y \leq 8.2 \cdot 10^{+111}:\\ \;\;\;\;x + \tanh \left(\frac{t}{y}\right) \cdot \left(y \cdot z\right)\\ \mathbf{else}:\\ \;\;\;\;x + z \cdot \left(t - x\right)\\ \end{array} \]
  5. Add Preprocessing

Alternative 4: 68.9% accurate, 10.6× speedup?

\[\begin{array}{l} y_m = \left|y\right| \\ \begin{array}{l} \mathbf{if}\;y\_m \leq 7 \cdot 10^{-18}:\\ \;\;\;\;x\\ \mathbf{elif}\;y\_m \leq 4.3 \cdot 10^{+111} \lor \neg \left(y\_m \leq 1.55 \cdot 10^{+180}\right):\\ \;\;\;\;x + z \cdot t\\ \mathbf{else}:\\ \;\;\;\;x \cdot \left(1 - z\right)\\ \end{array} \end{array} \]
y_m = (fabs.f64 y)
(FPCore (x y_m z t)
 :precision binary64
 (if (<= y_m 7e-18)
   x
   (if (or (<= y_m 4.3e+111) (not (<= y_m 1.55e+180)))
     (+ x (* z t))
     (* x (- 1.0 z)))))
y_m = fabs(y);
double code(double x, double y_m, double z, double t) {
	double tmp;
	if (y_m <= 7e-18) {
		tmp = x;
	} else if ((y_m <= 4.3e+111) || !(y_m <= 1.55e+180)) {
		tmp = x + (z * t);
	} else {
		tmp = x * (1.0 - z);
	}
	return tmp;
}
y_m = abs(y)
real(8) function code(x, y_m, z, t)
    real(8), intent (in) :: x
    real(8), intent (in) :: y_m
    real(8), intent (in) :: z
    real(8), intent (in) :: t
    real(8) :: tmp
    if (y_m <= 7d-18) then
        tmp = x
    else if ((y_m <= 4.3d+111) .or. (.not. (y_m <= 1.55d+180))) then
        tmp = x + (z * t)
    else
        tmp = x * (1.0d0 - z)
    end if
    code = tmp
end function
y_m = Math.abs(y);
public static double code(double x, double y_m, double z, double t) {
	double tmp;
	if (y_m <= 7e-18) {
		tmp = x;
	} else if ((y_m <= 4.3e+111) || !(y_m <= 1.55e+180)) {
		tmp = x + (z * t);
	} else {
		tmp = x * (1.0 - z);
	}
	return tmp;
}
y_m = math.fabs(y)
def code(x, y_m, z, t):
	tmp = 0
	if y_m <= 7e-18:
		tmp = x
	elif (y_m <= 4.3e+111) or not (y_m <= 1.55e+180):
		tmp = x + (z * t)
	else:
		tmp = x * (1.0 - z)
	return tmp
y_m = abs(y)
function code(x, y_m, z, t)
	tmp = 0.0
	if (y_m <= 7e-18)
		tmp = x;
	elseif ((y_m <= 4.3e+111) || !(y_m <= 1.55e+180))
		tmp = Float64(x + Float64(z * t));
	else
		tmp = Float64(x * Float64(1.0 - z));
	end
	return tmp
end
y_m = abs(y);
function tmp_2 = code(x, y_m, z, t)
	tmp = 0.0;
	if (y_m <= 7e-18)
		tmp = x;
	elseif ((y_m <= 4.3e+111) || ~((y_m <= 1.55e+180)))
		tmp = x + (z * t);
	else
		tmp = x * (1.0 - z);
	end
	tmp_2 = tmp;
end
y_m = N[Abs[y], $MachinePrecision]
code[x_, y$95$m_, z_, t_] := If[LessEqual[y$95$m, 7e-18], x, If[Or[LessEqual[y$95$m, 4.3e+111], N[Not[LessEqual[y$95$m, 1.55e+180]], $MachinePrecision]], N[(x + N[(z * t), $MachinePrecision]), $MachinePrecision], N[(x * N[(1.0 - z), $MachinePrecision]), $MachinePrecision]]]
\begin{array}{l}
y_m = \left|y\right|

\\
\begin{array}{l}
\mathbf{if}\;y\_m \leq 7 \cdot 10^{-18}:\\
\;\;\;\;x\\

\mathbf{elif}\;y\_m \leq 4.3 \cdot 10^{+111} \lor \neg \left(y\_m \leq 1.55 \cdot 10^{+180}\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 < 6.9999999999999997e-18

    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. Add Preprocessing
    3. Taylor expanded in x around inf 62.6%

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

    if 6.9999999999999997e-18 < y < 4.29999999999999993e111 or 1.54999999999999999e180 < y

    1. Initial program 90.7%

      \[x + \left(y \cdot z\right) \cdot \left(\tanh \left(\frac{t}{y}\right) - \tanh \left(\frac{x}{y}\right)\right) \]
    2. Add Preprocessing
    3. Taylor expanded in x around 0 32.1%

      \[\leadsto x + \left(y \cdot z\right) \cdot \color{blue}{\left(\frac{e^{\frac{t}{y}}}{e^{\frac{t}{y}} + \frac{1}{e^{\frac{t}{y}}}} - \frac{1}{e^{\frac{t}{y}} \cdot \left(e^{\frac{t}{y}} + \frac{1}{e^{\frac{t}{y}}}\right)}\right)} \]
    4. Step-by-step derivation
      1. associate-/r*32.1%

        \[\leadsto x + \left(y \cdot z\right) \cdot \left(\frac{e^{\frac{t}{y}}}{e^{\frac{t}{y}} + \frac{1}{e^{\frac{t}{y}}}} - \color{blue}{\frac{\frac{1}{e^{\frac{t}{y}}}}{e^{\frac{t}{y}} + \frac{1}{e^{\frac{t}{y}}}}}\right) \]
      2. rec-exp32.1%

        \[\leadsto x + \left(y \cdot z\right) \cdot \left(\frac{e^{\frac{t}{y}}}{e^{\frac{t}{y}} + \frac{1}{e^{\frac{t}{y}}}} - \frac{\color{blue}{e^{-\frac{t}{y}}}}{e^{\frac{t}{y}} + \frac{1}{e^{\frac{t}{y}}}}\right) \]
      3. div-sub32.1%

        \[\leadsto x + \left(y \cdot z\right) \cdot \color{blue}{\frac{e^{\frac{t}{y}} - e^{-\frac{t}{y}}}{e^{\frac{t}{y}} + \frac{1}{e^{\frac{t}{y}}}}} \]
      4. rec-exp32.1%

        \[\leadsto x + \left(y \cdot z\right) \cdot \frac{e^{\frac{t}{y}} - e^{-\frac{t}{y}}}{e^{\frac{t}{y}} + \color{blue}{e^{-\frac{t}{y}}}} \]
      5. tanh-def-a82.3%

        \[\leadsto x + \left(y \cdot z\right) \cdot \color{blue}{\tanh \left(\frac{t}{y}\right)} \]
    5. Simplified82.3%

      \[\leadsto x + \left(y \cdot z\right) \cdot \color{blue}{\tanh \left(\frac{t}{y}\right)} \]
    6. Taylor expanded in y around inf 71.3%

      \[\leadsto \color{blue}{x + t \cdot z} \]
    7. Step-by-step derivation
      1. +-commutative71.3%

        \[\leadsto \color{blue}{t \cdot z + x} \]
      2. *-commutative71.3%

        \[\leadsto \color{blue}{z \cdot t} + x \]
    8. Simplified71.3%

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

    if 4.29999999999999993e111 < y < 1.54999999999999999e180

    1. Initial program 72.6%

      \[x + \left(y \cdot z\right) \cdot \left(\tanh \left(\frac{t}{y}\right) - \tanh \left(\frac{x}{y}\right)\right) \]
    2. Add Preprocessing
    3. Taylor expanded in y around inf 93.2%

      \[\leadsto x + \color{blue}{z \cdot \left(t - x\right)} \]
    4. Taylor expanded in x around inf 92.9%

      \[\leadsto \color{blue}{x \cdot \left(1 + -1 \cdot z\right)} \]
    5. Step-by-step derivation
      1. mul-1-neg92.9%

        \[\leadsto x \cdot \left(1 + \color{blue}{\left(-z\right)}\right) \]
      2. unsub-neg92.9%

        \[\leadsto x \cdot \color{blue}{\left(1 - z\right)} \]
    6. Simplified92.9%

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

    \[\leadsto \begin{array}{l} \mathbf{if}\;y \leq 7 \cdot 10^{-18}:\\ \;\;\;\;x\\ \mathbf{elif}\;y \leq 4.3 \cdot 10^{+111} \lor \neg \left(y \leq 1.55 \cdot 10^{+180}\right):\\ \;\;\;\;x + z \cdot t\\ \mathbf{else}:\\ \;\;\;\;x \cdot \left(1 - z\right)\\ \end{array} \]
  5. Add Preprocessing

Alternative 5: 78.2% accurate, 17.7× speedup?

\[\begin{array}{l} y_m = \left|y\right| \\ \begin{array}{l} \mathbf{if}\;y\_m \leq 5.5 \cdot 10^{+40}:\\ \;\;\;\;x\\ \mathbf{else}:\\ \;\;\;\;x + z \cdot \left(t - x\right)\\ \end{array} \end{array} \]
y_m = (fabs.f64 y)
(FPCore (x y_m z t)
 :precision binary64
 (if (<= y_m 5.5e+40) x (+ x (* z (- t x)))))
y_m = fabs(y);
double code(double x, double y_m, double z, double t) {
	double tmp;
	if (y_m <= 5.5e+40) {
		tmp = x;
	} else {
		tmp = x + (z * (t - x));
	}
	return tmp;
}
y_m = abs(y)
real(8) function code(x, y_m, z, t)
    real(8), intent (in) :: x
    real(8), intent (in) :: y_m
    real(8), intent (in) :: z
    real(8), intent (in) :: t
    real(8) :: tmp
    if (y_m <= 5.5d+40) then
        tmp = x
    else
        tmp = x + (z * (t - x))
    end if
    code = tmp
end function
y_m = Math.abs(y);
public static double code(double x, double y_m, double z, double t) {
	double tmp;
	if (y_m <= 5.5e+40) {
		tmp = x;
	} else {
		tmp = x + (z * (t - x));
	}
	return tmp;
}
y_m = math.fabs(y)
def code(x, y_m, z, t):
	tmp = 0
	if y_m <= 5.5e+40:
		tmp = x
	else:
		tmp = x + (z * (t - x))
	return tmp
y_m = abs(y)
function code(x, y_m, z, t)
	tmp = 0.0
	if (y_m <= 5.5e+40)
		tmp = x;
	else
		tmp = Float64(x + Float64(z * Float64(t - x)));
	end
	return tmp
end
y_m = abs(y);
function tmp_2 = code(x, y_m, z, t)
	tmp = 0.0;
	if (y_m <= 5.5e+40)
		tmp = x;
	else
		tmp = x + (z * (t - x));
	end
	tmp_2 = tmp;
end
y_m = N[Abs[y], $MachinePrecision]
code[x_, y$95$m_, z_, t_] := If[LessEqual[y$95$m, 5.5e+40], x, N[(x + N[(z * N[(t - x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
y_m = \left|y\right|

\\
\begin{array}{l}
\mathbf{if}\;y\_m \leq 5.5 \cdot 10^{+40}:\\
\;\;\;\;x\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if y < 5.49999999999999974e40

    1. Initial program 96.2%

      \[x + \left(y \cdot z\right) \cdot \left(\tanh \left(\frac{t}{y}\right) - \tanh \left(\frac{x}{y}\right)\right) \]
    2. Add Preprocessing
    3. Taylor expanded in x around inf 62.6%

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

    if 5.49999999999999974e40 < y

    1. Initial program 85.2%

      \[x + \left(y \cdot z\right) \cdot \left(\tanh \left(\frac{t}{y}\right) - \tanh \left(\frac{x}{y}\right)\right) \]
    2. Add Preprocessing
    3. Taylor expanded in y around inf 84.0%

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

Alternative 6: 66.6% accurate, 21.3× speedup?

\[\begin{array}{l} y_m = \left|y\right| \\ \begin{array}{l} \mathbf{if}\;y\_m \leq 3.7 \cdot 10^{+102}:\\ \;\;\;\;x\\ \mathbf{else}:\\ \;\;\;\;x \cdot \left(1 - z\right)\\ \end{array} \end{array} \]
y_m = (fabs.f64 y)
(FPCore (x y_m z t)
 :precision binary64
 (if (<= y_m 3.7e+102) x (* x (- 1.0 z))))
y_m = fabs(y);
double code(double x, double y_m, double z, double t) {
	double tmp;
	if (y_m <= 3.7e+102) {
		tmp = x;
	} else {
		tmp = x * (1.0 - z);
	}
	return tmp;
}
y_m = abs(y)
real(8) function code(x, y_m, z, t)
    real(8), intent (in) :: x
    real(8), intent (in) :: y_m
    real(8), intent (in) :: z
    real(8), intent (in) :: t
    real(8) :: tmp
    if (y_m <= 3.7d+102) then
        tmp = x
    else
        tmp = x * (1.0d0 - z)
    end if
    code = tmp
end function
y_m = Math.abs(y);
public static double code(double x, double y_m, double z, double t) {
	double tmp;
	if (y_m <= 3.7e+102) {
		tmp = x;
	} else {
		tmp = x * (1.0 - z);
	}
	return tmp;
}
y_m = math.fabs(y)
def code(x, y_m, z, t):
	tmp = 0
	if y_m <= 3.7e+102:
		tmp = x
	else:
		tmp = x * (1.0 - z)
	return tmp
y_m = abs(y)
function code(x, y_m, z, t)
	tmp = 0.0
	if (y_m <= 3.7e+102)
		tmp = x;
	else
		tmp = Float64(x * Float64(1.0 - z));
	end
	return tmp
end
y_m = abs(y);
function tmp_2 = code(x, y_m, z, t)
	tmp = 0.0;
	if (y_m <= 3.7e+102)
		tmp = x;
	else
		tmp = x * (1.0 - z);
	end
	tmp_2 = tmp;
end
y_m = N[Abs[y], $MachinePrecision]
code[x_, y$95$m_, z_, t_] := If[LessEqual[y$95$m, 3.7e+102], x, N[(x * N[(1.0 - z), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
y_m = \left|y\right|

\\
\begin{array}{l}
\mathbf{if}\;y\_m \leq 3.7 \cdot 10^{+102}:\\
\;\;\;\;x\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if y < 3.70000000000000023e102

    1. Initial program 96.4%

      \[x + \left(y \cdot z\right) \cdot \left(\tanh \left(\frac{t}{y}\right) - \tanh \left(\frac{x}{y}\right)\right) \]
    2. Add Preprocessing
    3. Taylor expanded in x around inf 60.2%

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

    if 3.70000000000000023e102 < y

    1. Initial program 80.0%

      \[x + \left(y \cdot z\right) \cdot \left(\tanh \left(\frac{t}{y}\right) - \tanh \left(\frac{x}{y}\right)\right) \]
    2. Add Preprocessing
    3. Taylor expanded in y around inf 93.4%

      \[\leadsto x + \color{blue}{z \cdot \left(t - x\right)} \]
    4. Taylor expanded in x around inf 68.5%

      \[\leadsto \color{blue}{x \cdot \left(1 + -1 \cdot z\right)} \]
    5. Step-by-step derivation
      1. mul-1-neg68.5%

        \[\leadsto x \cdot \left(1 + \color{blue}{\left(-z\right)}\right) \]
      2. unsub-neg68.5%

        \[\leadsto x \cdot \color{blue}{\left(1 - z\right)} \]
    6. Simplified68.5%

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

Alternative 7: 59.7% accurate, 213.0× speedup?

\[\begin{array}{l} y_m = \left|y\right| \\ x \end{array} \]
y_m = (fabs.f64 y)
(FPCore (x y_m z t) :precision binary64 x)
y_m = fabs(y);
double code(double x, double y_m, double z, double t) {
	return x;
}
y_m = abs(y)
real(8) function code(x, y_m, z, t)
    real(8), intent (in) :: x
    real(8), intent (in) :: y_m
    real(8), intent (in) :: z
    real(8), intent (in) :: t
    code = x
end function
y_m = Math.abs(y);
public static double code(double x, double y_m, double z, double t) {
	return x;
}
y_m = math.fabs(y)
def code(x, y_m, z, t):
	return x
y_m = abs(y)
function code(x, y_m, z, t)
	return x
end
y_m = abs(y);
function tmp = code(x, y_m, z, t)
	tmp = x;
end
y_m = N[Abs[y], $MachinePrecision]
code[x_, y$95$m_, z_, t_] := x
\begin{array}{l}
y_m = \left|y\right|

\\
x
\end{array}
Derivation
  1. Initial program 93.6%

    \[x + \left(y \cdot z\right) \cdot \left(\tanh \left(\frac{t}{y}\right) - \tanh \left(\frac{x}{y}\right)\right) \]
  2. Add Preprocessing
  3. Taylor expanded in x around inf 57.8%

    \[\leadsto \color{blue}{x} \]
  4. Add Preprocessing

Developer target: 96.9% 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 2024092 
(FPCore (x y z t)
  :name "SynthBasics:moogVCF from YampaSynth-0.2"
  :precision binary64

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

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