System.Random.MWC.Distributions:truncatedExp from mwc-random-0.13.3.2

Percentage Accurate: 61.0% → 98.4%
Time: 22.0s
Alternatives: 8
Speedup: 211.0×

Specification

?
\[\begin{array}{l} \\ x - \frac{\log \left(\left(1 - y\right) + y \cdot e^{z}\right)}{t} \end{array} \]
(FPCore (x y z t)
 :precision binary64
 (- x (/ (log (+ (- 1.0 y) (* y (exp z)))) t)))
double code(double x, double y, double z, double t) {
	return x - (log(((1.0 - y) + (y * exp(z)))) / t);
}
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 - (log(((1.0d0 - y) + (y * exp(z)))) / t)
end function
public static double code(double x, double y, double z, double t) {
	return x - (Math.log(((1.0 - y) + (y * Math.exp(z)))) / t);
}
def code(x, y, z, t):
	return x - (math.log(((1.0 - y) + (y * math.exp(z)))) / t)
function code(x, y, z, t)
	return Float64(x - Float64(log(Float64(Float64(1.0 - y) + Float64(y * exp(z)))) / t))
end
function tmp = code(x, y, z, t)
	tmp = x - (log(((1.0 - y) + (y * exp(z)))) / t);
end
code[x_, y_, z_, t_] := N[(x - N[(N[Log[N[(N[(1.0 - y), $MachinePrecision] + N[(y * N[Exp[z], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] / t), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
x - \frac{\log \left(\left(1 - y\right) + y \cdot e^{z}\right)}{t}
\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: 61.0% accurate, 1.0× speedup?

\[\begin{array}{l} \\ x - \frac{\log \left(\left(1 - y\right) + y \cdot e^{z}\right)}{t} \end{array} \]
(FPCore (x y z t)
 :precision binary64
 (- x (/ (log (+ (- 1.0 y) (* y (exp z)))) t)))
double code(double x, double y, double z, double t) {
	return x - (log(((1.0 - y) + (y * exp(z)))) / t);
}
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 - (log(((1.0d0 - y) + (y * exp(z)))) / t)
end function
public static double code(double x, double y, double z, double t) {
	return x - (Math.log(((1.0 - y) + (y * Math.exp(z)))) / t);
}
def code(x, y, z, t):
	return x - (math.log(((1.0 - y) + (y * math.exp(z)))) / t)
function code(x, y, z, t)
	return Float64(x - Float64(log(Float64(Float64(1.0 - y) + Float64(y * exp(z)))) / t))
end
function tmp = code(x, y, z, t)
	tmp = x - (log(((1.0 - y) + (y * exp(z)))) / t);
end
code[x_, y_, z_, t_] := N[(x - N[(N[Log[N[(N[(1.0 - y), $MachinePrecision] + N[(y * N[Exp[z], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] / t), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
x - \frac{\log \left(\left(1 - y\right) + y \cdot e^{z}\right)}{t}
\end{array}

Alternative 1: 98.4% accurate, 1.0× speedup?

\[\begin{array}{l} \\ x - \frac{\mathsf{log1p}\left(y \cdot \mathsf{expm1}\left(z\right)\right)}{t} \end{array} \]
(FPCore (x y z t) :precision binary64 (- x (/ (log1p (* y (expm1 z))) t)))
double code(double x, double y, double z, double t) {
	return x - (log1p((y * expm1(z))) / t);
}
public static double code(double x, double y, double z, double t) {
	return x - (Math.log1p((y * Math.expm1(z))) / t);
}
def code(x, y, z, t):
	return x - (math.log1p((y * math.expm1(z))) / t)
function code(x, y, z, t)
	return Float64(x - Float64(log1p(Float64(y * expm1(z))) / t))
end
code[x_, y_, z_, t_] := N[(x - N[(N[Log[1 + N[(y * N[(Exp[z] - 1), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] / t), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
x - \frac{\mathsf{log1p}\left(y \cdot \mathsf{expm1}\left(z\right)\right)}{t}
\end{array}
Derivation
  1. Initial program 64.2%

    \[x - \frac{\log \left(\left(1 - y\right) + y \cdot e^{z}\right)}{t} \]
  2. Step-by-step derivation
    1. associate-+l-81.1%

      \[\leadsto x - \frac{\log \color{blue}{\left(1 - \left(y - y \cdot e^{z}\right)\right)}}{t} \]
    2. sub-neg81.1%

      \[\leadsto x - \frac{\log \color{blue}{\left(1 + \left(-\left(y - y \cdot e^{z}\right)\right)\right)}}{t} \]
    3. log1p-define85.6%

      \[\leadsto x - \frac{\color{blue}{\mathsf{log1p}\left(-\left(y - y \cdot e^{z}\right)\right)}}{t} \]
    4. neg-sub085.6%

      \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{0 - \left(y - y \cdot e^{z}\right)}\right)}{t} \]
    5. associate-+l-85.6%

      \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{\left(0 - y\right) + y \cdot e^{z}}\right)}{t} \]
    6. neg-sub085.6%

      \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{\left(-y\right)} + y \cdot e^{z}\right)}{t} \]
    7. +-commutative85.6%

      \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{y \cdot e^{z} + \left(-y\right)}\right)}{t} \]
    8. unsub-neg85.6%

      \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{y \cdot e^{z} - y}\right)}{t} \]
    9. *-rgt-identity85.6%

      \[\leadsto x - \frac{\mathsf{log1p}\left(y \cdot e^{z} - \color{blue}{y \cdot 1}\right)}{t} \]
    10. distribute-lft-out--85.6%

      \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{y \cdot \left(e^{z} - 1\right)}\right)}{t} \]
    11. expm1-define98.8%

      \[\leadsto x - \frac{\mathsf{log1p}\left(y \cdot \color{blue}{\mathsf{expm1}\left(z\right)}\right)}{t} \]
  3. Simplified98.8%

    \[\leadsto \color{blue}{x - \frac{\mathsf{log1p}\left(y \cdot \mathsf{expm1}\left(z\right)\right)}{t}} \]
  4. Add Preprocessing
  5. Final simplification98.8%

    \[\leadsto x - \frac{\mathsf{log1p}\left(y \cdot \mathsf{expm1}\left(z\right)\right)}{t} \]
  6. Add Preprocessing

Alternative 2: 93.9% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;e^{z} \leq 0.005:\\ \;\;\;\;x + \frac{1}{\frac{\frac{t}{1 - e^{z}} - 0.5 \cdot \left(y \cdot t\right)}{y}}\\ \mathbf{else}:\\ \;\;\;\;x - \frac{\mathsf{log1p}\left(z \cdot \left(y + 0.5 \cdot \left(y \cdot z\right)\right)\right)}{t}\\ \end{array} \end{array} \]
(FPCore (x y z t)
 :precision binary64
 (if (<= (exp z) 0.005)
   (+ x (/ 1.0 (/ (- (/ t (- 1.0 (exp z))) (* 0.5 (* y t))) y)))
   (- x (/ (log1p (* z (+ y (* 0.5 (* y z))))) t))))
double code(double x, double y, double z, double t) {
	double tmp;
	if (exp(z) <= 0.005) {
		tmp = x + (1.0 / (((t / (1.0 - exp(z))) - (0.5 * (y * t))) / y));
	} else {
		tmp = x - (log1p((z * (y + (0.5 * (y * z))))) / t);
	}
	return tmp;
}
public static double code(double x, double y, double z, double t) {
	double tmp;
	if (Math.exp(z) <= 0.005) {
		tmp = x + (1.0 / (((t / (1.0 - Math.exp(z))) - (0.5 * (y * t))) / y));
	} else {
		tmp = x - (Math.log1p((z * (y + (0.5 * (y * z))))) / t);
	}
	return tmp;
}
def code(x, y, z, t):
	tmp = 0
	if math.exp(z) <= 0.005:
		tmp = x + (1.0 / (((t / (1.0 - math.exp(z))) - (0.5 * (y * t))) / y))
	else:
		tmp = x - (math.log1p((z * (y + (0.5 * (y * z))))) / t)
	return tmp
function code(x, y, z, t)
	tmp = 0.0
	if (exp(z) <= 0.005)
		tmp = Float64(x + Float64(1.0 / Float64(Float64(Float64(t / Float64(1.0 - exp(z))) - Float64(0.5 * Float64(y * t))) / y)));
	else
		tmp = Float64(x - Float64(log1p(Float64(z * Float64(y + Float64(0.5 * Float64(y * z))))) / t));
	end
	return tmp
end
code[x_, y_, z_, t_] := If[LessEqual[N[Exp[z], $MachinePrecision], 0.005], N[(x + N[(1.0 / N[(N[(N[(t / N[(1.0 - N[Exp[z], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] - N[(0.5 * N[(y * t), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / y), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(x - N[(N[Log[1 + N[(z * N[(y + N[(0.5 * N[(y * z), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] / t), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;e^{z} \leq 0.005:\\
\;\;\;\;x + \frac{1}{\frac{\frac{t}{1 - e^{z}} - 0.5 \cdot \left(y \cdot t\right)}{y}}\\

\mathbf{else}:\\
\;\;\;\;x - \frac{\mathsf{log1p}\left(z \cdot \left(y + 0.5 \cdot \left(y \cdot z\right)\right)\right)}{t}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (exp.f64 z) < 0.0050000000000000001

    1. Initial program 86.1%

      \[x - \frac{\log \left(\left(1 - y\right) + y \cdot e^{z}\right)}{t} \]
    2. Step-by-step derivation
      1. associate-+l-86.1%

        \[\leadsto x - \frac{\log \color{blue}{\left(1 - \left(y - y \cdot e^{z}\right)\right)}}{t} \]
      2. sub-neg86.1%

        \[\leadsto x - \frac{\log \color{blue}{\left(1 + \left(-\left(y - y \cdot e^{z}\right)\right)\right)}}{t} \]
      3. log1p-define99.9%

        \[\leadsto x - \frac{\color{blue}{\mathsf{log1p}\left(-\left(y - y \cdot e^{z}\right)\right)}}{t} \]
      4. neg-sub099.9%

        \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{0 - \left(y - y \cdot e^{z}\right)}\right)}{t} \]
      5. associate-+l-99.9%

        \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{\left(0 - y\right) + y \cdot e^{z}}\right)}{t} \]
      6. neg-sub099.9%

        \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{\left(-y\right)} + y \cdot e^{z}\right)}{t} \]
      7. +-commutative99.9%

        \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{y \cdot e^{z} + \left(-y\right)}\right)}{t} \]
      8. unsub-neg99.9%

        \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{y \cdot e^{z} - y}\right)}{t} \]
      9. *-rgt-identity99.9%

        \[\leadsto x - \frac{\mathsf{log1p}\left(y \cdot e^{z} - \color{blue}{y \cdot 1}\right)}{t} \]
      10. distribute-lft-out--99.9%

        \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{y \cdot \left(e^{z} - 1\right)}\right)}{t} \]
      11. expm1-define99.9%

        \[\leadsto x - \frac{\mathsf{log1p}\left(y \cdot \color{blue}{\mathsf{expm1}\left(z\right)}\right)}{t} \]
    3. Simplified99.9%

      \[\leadsto \color{blue}{x - \frac{\mathsf{log1p}\left(y \cdot \mathsf{expm1}\left(z\right)\right)}{t}} \]
    4. Add Preprocessing
    5. Step-by-step derivation
      1. clear-num99.7%

        \[\leadsto x - \color{blue}{\frac{1}{\frac{t}{\mathsf{log1p}\left(y \cdot \mathsf{expm1}\left(z\right)\right)}}} \]
      2. associate-/r/99.8%

        \[\leadsto x - \color{blue}{\frac{1}{t} \cdot \mathsf{log1p}\left(y \cdot \mathsf{expm1}\left(z\right)\right)} \]
    6. Applied egg-rr99.8%

      \[\leadsto x - \color{blue}{\frac{1}{t} \cdot \mathsf{log1p}\left(y \cdot \mathsf{expm1}\left(z\right)\right)} \]
    7. Step-by-step derivation
      1. associate-*l/99.9%

        \[\leadsto x - \color{blue}{\frac{1 \cdot \mathsf{log1p}\left(y \cdot \mathsf{expm1}\left(z\right)\right)}{t}} \]
      2. *-un-lft-identity99.9%

        \[\leadsto x - \frac{\color{blue}{\mathsf{log1p}\left(y \cdot \mathsf{expm1}\left(z\right)\right)}}{t} \]
      3. clear-num99.7%

        \[\leadsto x - \color{blue}{\frac{1}{\frac{t}{\mathsf{log1p}\left(y \cdot \mathsf{expm1}\left(z\right)\right)}}} \]
    8. Applied egg-rr99.7%

      \[\leadsto x - \color{blue}{\frac{1}{\frac{t}{\mathsf{log1p}\left(y \cdot \mathsf{expm1}\left(z\right)\right)}}} \]
    9. Taylor expanded in y around 0 79.0%

      \[\leadsto x - \frac{1}{\color{blue}{\frac{0.5 \cdot \left(t \cdot y\right) + \frac{t}{e^{z} - 1}}{y}}} \]

    if 0.0050000000000000001 < (exp.f64 z)

    1. Initial program 53.7%

      \[x - \frac{\log \left(\left(1 - y\right) + y \cdot e^{z}\right)}{t} \]
    2. Step-by-step derivation
      1. associate-+l-78.7%

        \[\leadsto x - \frac{\log \color{blue}{\left(1 - \left(y - y \cdot e^{z}\right)\right)}}{t} \]
      2. sub-neg78.7%

        \[\leadsto x - \frac{\log \color{blue}{\left(1 + \left(-\left(y - y \cdot e^{z}\right)\right)\right)}}{t} \]
      3. log1p-define78.7%

        \[\leadsto x - \frac{\color{blue}{\mathsf{log1p}\left(-\left(y - y \cdot e^{z}\right)\right)}}{t} \]
      4. neg-sub078.7%

        \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{0 - \left(y - y \cdot e^{z}\right)}\right)}{t} \]
      5. associate-+l-78.7%

        \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{\left(0 - y\right) + y \cdot e^{z}}\right)}{t} \]
      6. neg-sub078.7%

        \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{\left(-y\right)} + y \cdot e^{z}\right)}{t} \]
      7. +-commutative78.7%

        \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{y \cdot e^{z} + \left(-y\right)}\right)}{t} \]
      8. unsub-neg78.7%

        \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{y \cdot e^{z} - y}\right)}{t} \]
      9. *-rgt-identity78.7%

        \[\leadsto x - \frac{\mathsf{log1p}\left(y \cdot e^{z} - \color{blue}{y \cdot 1}\right)}{t} \]
      10. distribute-lft-out--78.7%

        \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{y \cdot \left(e^{z} - 1\right)}\right)}{t} \]
      11. expm1-define98.2%

        \[\leadsto x - \frac{\mathsf{log1p}\left(y \cdot \color{blue}{\mathsf{expm1}\left(z\right)}\right)}{t} \]
    3. Simplified98.2%

      \[\leadsto \color{blue}{x - \frac{\mathsf{log1p}\left(y \cdot \mathsf{expm1}\left(z\right)\right)}{t}} \]
    4. Add Preprocessing
    5. Taylor expanded in z around 0 97.8%

      \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{z \cdot \left(y + 0.5 \cdot \left(y \cdot z\right)\right)}\right)}{t} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification91.7%

    \[\leadsto \begin{array}{l} \mathbf{if}\;e^{z} \leq 0.005:\\ \;\;\;\;x + \frac{1}{\frac{\frac{t}{1 - e^{z}} - 0.5 \cdot \left(y \cdot t\right)}{y}}\\ \mathbf{else}:\\ \;\;\;\;x - \frac{\mathsf{log1p}\left(z \cdot \left(y + 0.5 \cdot \left(y \cdot z\right)\right)\right)}{t}\\ \end{array} \]
  5. Add Preprocessing

Alternative 3: 93.6% accurate, 1.7× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;z \leq -1.7 \cdot 10^{+18}:\\ \;\;\;\;x + \frac{1}{\frac{\frac{t}{1 - e^{z}} - 0.5 \cdot \left(y \cdot t\right)}{y}}\\ \mathbf{else}:\\ \;\;\;\;x - \frac{\mathsf{log1p}\left(z \cdot \left(y + y \cdot \left(z \cdot \left(0.5 + z \cdot 0.16666666666666666\right)\right)\right)\right)}{t}\\ \end{array} \end{array} \]
(FPCore (x y z t)
 :precision binary64
 (if (<= z -1.7e+18)
   (+ x (/ 1.0 (/ (- (/ t (- 1.0 (exp z))) (* 0.5 (* y t))) y)))
   (-
    x
    (/ (log1p (* z (+ y (* y (* z (+ 0.5 (* z 0.16666666666666666))))))) t))))
double code(double x, double y, double z, double t) {
	double tmp;
	if (z <= -1.7e+18) {
		tmp = x + (1.0 / (((t / (1.0 - exp(z))) - (0.5 * (y * t))) / y));
	} else {
		tmp = x - (log1p((z * (y + (y * (z * (0.5 + (z * 0.16666666666666666))))))) / t);
	}
	return tmp;
}
public static double code(double x, double y, double z, double t) {
	double tmp;
	if (z <= -1.7e+18) {
		tmp = x + (1.0 / (((t / (1.0 - Math.exp(z))) - (0.5 * (y * t))) / y));
	} else {
		tmp = x - (Math.log1p((z * (y + (y * (z * (0.5 + (z * 0.16666666666666666))))))) / t);
	}
	return tmp;
}
def code(x, y, z, t):
	tmp = 0
	if z <= -1.7e+18:
		tmp = x + (1.0 / (((t / (1.0 - math.exp(z))) - (0.5 * (y * t))) / y))
	else:
		tmp = x - (math.log1p((z * (y + (y * (z * (0.5 + (z * 0.16666666666666666))))))) / t)
	return tmp
function code(x, y, z, t)
	tmp = 0.0
	if (z <= -1.7e+18)
		tmp = Float64(x + Float64(1.0 / Float64(Float64(Float64(t / Float64(1.0 - exp(z))) - Float64(0.5 * Float64(y * t))) / y)));
	else
		tmp = Float64(x - Float64(log1p(Float64(z * Float64(y + Float64(y * Float64(z * Float64(0.5 + Float64(z * 0.16666666666666666))))))) / t));
	end
	return tmp
end
code[x_, y_, z_, t_] := If[LessEqual[z, -1.7e+18], N[(x + N[(1.0 / N[(N[(N[(t / N[(1.0 - N[Exp[z], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] - N[(0.5 * N[(y * t), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / y), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(x - N[(N[Log[1 + N[(z * N[(y + N[(y * N[(z * N[(0.5 + N[(z * 0.16666666666666666), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] / t), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;z \leq -1.7 \cdot 10^{+18}:\\
\;\;\;\;x + \frac{1}{\frac{\frac{t}{1 - e^{z}} - 0.5 \cdot \left(y \cdot t\right)}{y}}\\

\mathbf{else}:\\
\;\;\;\;x - \frac{\mathsf{log1p}\left(z \cdot \left(y + y \cdot \left(z \cdot \left(0.5 + z \cdot 0.16666666666666666\right)\right)\right)\right)}{t}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if z < -1.7e18

    1. Initial program 85.3%

      \[x - \frac{\log \left(\left(1 - y\right) + y \cdot e^{z}\right)}{t} \]
    2. Step-by-step derivation
      1. associate-+l-85.3%

        \[\leadsto x - \frac{\log \color{blue}{\left(1 - \left(y - y \cdot e^{z}\right)\right)}}{t} \]
      2. sub-neg85.3%

        \[\leadsto x - \frac{\log \color{blue}{\left(1 + \left(-\left(y - y \cdot e^{z}\right)\right)\right)}}{t} \]
      3. log1p-define99.9%

        \[\leadsto x - \frac{\color{blue}{\mathsf{log1p}\left(-\left(y - y \cdot e^{z}\right)\right)}}{t} \]
      4. neg-sub099.9%

        \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{0 - \left(y - y \cdot e^{z}\right)}\right)}{t} \]
      5. associate-+l-99.9%

        \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{\left(0 - y\right) + y \cdot e^{z}}\right)}{t} \]
      6. neg-sub099.9%

        \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{\left(-y\right)} + y \cdot e^{z}\right)}{t} \]
      7. +-commutative99.9%

        \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{y \cdot e^{z} + \left(-y\right)}\right)}{t} \]
      8. unsub-neg99.9%

        \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{y \cdot e^{z} - y}\right)}{t} \]
      9. *-rgt-identity99.9%

        \[\leadsto x - \frac{\mathsf{log1p}\left(y \cdot e^{z} - \color{blue}{y \cdot 1}\right)}{t} \]
      10. distribute-lft-out--99.9%

        \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{y \cdot \left(e^{z} - 1\right)}\right)}{t} \]
      11. expm1-define99.9%

        \[\leadsto x - \frac{\mathsf{log1p}\left(y \cdot \color{blue}{\mathsf{expm1}\left(z\right)}\right)}{t} \]
    3. Simplified99.9%

      \[\leadsto \color{blue}{x - \frac{\mathsf{log1p}\left(y \cdot \mathsf{expm1}\left(z\right)\right)}{t}} \]
    4. Add Preprocessing
    5. Step-by-step derivation
      1. clear-num99.7%

        \[\leadsto x - \color{blue}{\frac{1}{\frac{t}{\mathsf{log1p}\left(y \cdot \mathsf{expm1}\left(z\right)\right)}}} \]
      2. associate-/r/99.8%

        \[\leadsto x - \color{blue}{\frac{1}{t} \cdot \mathsf{log1p}\left(y \cdot \mathsf{expm1}\left(z\right)\right)} \]
    6. Applied egg-rr99.8%

      \[\leadsto x - \color{blue}{\frac{1}{t} \cdot \mathsf{log1p}\left(y \cdot \mathsf{expm1}\left(z\right)\right)} \]
    7. Step-by-step derivation
      1. associate-*l/99.9%

        \[\leadsto x - \color{blue}{\frac{1 \cdot \mathsf{log1p}\left(y \cdot \mathsf{expm1}\left(z\right)\right)}{t}} \]
      2. *-un-lft-identity99.9%

        \[\leadsto x - \frac{\color{blue}{\mathsf{log1p}\left(y \cdot \mathsf{expm1}\left(z\right)\right)}}{t} \]
      3. clear-num99.7%

        \[\leadsto x - \color{blue}{\frac{1}{\frac{t}{\mathsf{log1p}\left(y \cdot \mathsf{expm1}\left(z\right)\right)}}} \]
    8. Applied egg-rr99.7%

      \[\leadsto x - \color{blue}{\frac{1}{\frac{t}{\mathsf{log1p}\left(y \cdot \mathsf{expm1}\left(z\right)\right)}}} \]
    9. Taylor expanded in y around 0 79.9%

      \[\leadsto x - \frac{1}{\color{blue}{\frac{0.5 \cdot \left(t \cdot y\right) + \frac{t}{e^{z} - 1}}{y}}} \]

    if -1.7e18 < z

    1. Initial program 55.0%

      \[x - \frac{\log \left(\left(1 - y\right) + y \cdot e^{z}\right)}{t} \]
    2. Step-by-step derivation
      1. associate-+l-79.3%

        \[\leadsto x - \frac{\log \color{blue}{\left(1 - \left(y - y \cdot e^{z}\right)\right)}}{t} \]
      2. sub-neg79.3%

        \[\leadsto x - \frac{\log \color{blue}{\left(1 + \left(-\left(y - y \cdot e^{z}\right)\right)\right)}}{t} \]
      3. log1p-define79.3%

        \[\leadsto x - \frac{\color{blue}{\mathsf{log1p}\left(-\left(y - y \cdot e^{z}\right)\right)}}{t} \]
      4. neg-sub079.3%

        \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{0 - \left(y - y \cdot e^{z}\right)}\right)}{t} \]
      5. associate-+l-79.3%

        \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{\left(0 - y\right) + y \cdot e^{z}}\right)}{t} \]
      6. neg-sub079.3%

        \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{\left(-y\right)} + y \cdot e^{z}\right)}{t} \]
      7. +-commutative79.3%

        \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{y \cdot e^{z} + \left(-y\right)}\right)}{t} \]
      8. unsub-neg79.3%

        \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{y \cdot e^{z} - y}\right)}{t} \]
      9. *-rgt-identity79.3%

        \[\leadsto x - \frac{\mathsf{log1p}\left(y \cdot e^{z} - \color{blue}{y \cdot 1}\right)}{t} \]
      10. distribute-lft-out--79.3%

        \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{y \cdot \left(e^{z} - 1\right)}\right)}{t} \]
      11. expm1-define98.3%

        \[\leadsto x - \frac{\mathsf{log1p}\left(y \cdot \color{blue}{\mathsf{expm1}\left(z\right)}\right)}{t} \]
    3. Simplified98.3%

      \[\leadsto \color{blue}{x - \frac{\mathsf{log1p}\left(y \cdot \mathsf{expm1}\left(z\right)\right)}{t}} \]
    4. Add Preprocessing
    5. Taylor expanded in z around 0 97.0%

      \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{z \cdot \left(y + z \cdot \left(0.16666666666666666 \cdot \left(y \cdot z\right) + 0.5 \cdot y\right)\right)}\right)}{t} \]
    6. Taylor expanded in t around 0 85.3%

      \[\leadsto x - \color{blue}{\frac{\log \left(1 + z \cdot \left(y + z \cdot \left(0.16666666666666666 \cdot \left(y \cdot z\right) + 0.5 \cdot y\right)\right)\right)}{t}} \]
    7. Step-by-step derivation
      1. Simplified97.0%

        \[\leadsto x - \color{blue}{\frac{\mathsf{log1p}\left(z \cdot \left(y + y \cdot \left(z \cdot \left(0.5 + z \cdot 0.16666666666666666\right)\right)\right)\right)}{t}} \]
    8. Recombined 2 regimes into one program.
    9. Final simplification91.8%

      \[\leadsto \begin{array}{l} \mathbf{if}\;z \leq -1.7 \cdot 10^{+18}:\\ \;\;\;\;x + \frac{1}{\frac{\frac{t}{1 - e^{z}} - 0.5 \cdot \left(y \cdot t\right)}{y}}\\ \mathbf{else}:\\ \;\;\;\;x - \frac{\mathsf{log1p}\left(z \cdot \left(y + y \cdot \left(z \cdot \left(0.5 + z \cdot 0.16666666666666666\right)\right)\right)\right)}{t}\\ \end{array} \]
    10. Add Preprocessing

    Alternative 4: 87.3% accurate, 1.9× speedup?

    \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;y \leq -250000000:\\ \;\;\;\;x + \frac{-1}{\frac{0.5 \cdot \left(z \cdot t\right) + \frac{t}{y}}{z}}\\ \mathbf{else}:\\ \;\;\;\;x - y \cdot \frac{\mathsf{expm1}\left(z\right)}{t}\\ \end{array} \end{array} \]
    (FPCore (x y z t)
     :precision binary64
     (if (<= y -250000000.0)
       (+ x (/ -1.0 (/ (+ (* 0.5 (* z t)) (/ t y)) z)))
       (- x (* y (/ (expm1 z) t)))))
    double code(double x, double y, double z, double t) {
    	double tmp;
    	if (y <= -250000000.0) {
    		tmp = x + (-1.0 / (((0.5 * (z * t)) + (t / y)) / z));
    	} else {
    		tmp = x - (y * (expm1(z) / t));
    	}
    	return tmp;
    }
    
    public static double code(double x, double y, double z, double t) {
    	double tmp;
    	if (y <= -250000000.0) {
    		tmp = x + (-1.0 / (((0.5 * (z * t)) + (t / y)) / z));
    	} else {
    		tmp = x - (y * (Math.expm1(z) / t));
    	}
    	return tmp;
    }
    
    def code(x, y, z, t):
    	tmp = 0
    	if y <= -250000000.0:
    		tmp = x + (-1.0 / (((0.5 * (z * t)) + (t / y)) / z))
    	else:
    		tmp = x - (y * (math.expm1(z) / t))
    	return tmp
    
    function code(x, y, z, t)
    	tmp = 0.0
    	if (y <= -250000000.0)
    		tmp = Float64(x + Float64(-1.0 / Float64(Float64(Float64(0.5 * Float64(z * t)) + Float64(t / y)) / z)));
    	else
    		tmp = Float64(x - Float64(y * Float64(expm1(z) / t)));
    	end
    	return tmp
    end
    
    code[x_, y_, z_, t_] := If[LessEqual[y, -250000000.0], N[(x + N[(-1.0 / N[(N[(N[(0.5 * N[(z * t), $MachinePrecision]), $MachinePrecision] + N[(t / y), $MachinePrecision]), $MachinePrecision] / z), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(x - N[(y * N[(N[(Exp[z] - 1), $MachinePrecision] / t), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
    
    \begin{array}{l}
    
    \\
    \begin{array}{l}
    \mathbf{if}\;y \leq -250000000:\\
    \;\;\;\;x + \frac{-1}{\frac{0.5 \cdot \left(z \cdot t\right) + \frac{t}{y}}{z}}\\
    
    \mathbf{else}:\\
    \;\;\;\;x - y \cdot \frac{\mathsf{expm1}\left(z\right)}{t}\\
    
    
    \end{array}
    \end{array}
    
    Derivation
    1. Split input into 2 regimes
    2. if y < -2.5e8

      1. Initial program 48.8%

        \[x - \frac{\log \left(\left(1 - y\right) + y \cdot e^{z}\right)}{t} \]
      2. Step-by-step derivation
        1. associate-+l-85.5%

          \[\leadsto x - \frac{\log \color{blue}{\left(1 - \left(y - y \cdot e^{z}\right)\right)}}{t} \]
        2. sub-neg85.5%

          \[\leadsto x - \frac{\log \color{blue}{\left(1 + \left(-\left(y - y \cdot e^{z}\right)\right)\right)}}{t} \]
        3. log1p-define85.5%

          \[\leadsto x - \frac{\color{blue}{\mathsf{log1p}\left(-\left(y - y \cdot e^{z}\right)\right)}}{t} \]
        4. neg-sub085.5%

          \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{0 - \left(y - y \cdot e^{z}\right)}\right)}{t} \]
        5. associate-+l-85.5%

          \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{\left(0 - y\right) + y \cdot e^{z}}\right)}{t} \]
        6. neg-sub085.5%

          \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{\left(-y\right)} + y \cdot e^{z}\right)}{t} \]
        7. +-commutative85.5%

          \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{y \cdot e^{z} + \left(-y\right)}\right)}{t} \]
        8. unsub-neg85.5%

          \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{y \cdot e^{z} - y}\right)}{t} \]
        9. *-rgt-identity85.5%

          \[\leadsto x - \frac{\mathsf{log1p}\left(y \cdot e^{z} - \color{blue}{y \cdot 1}\right)}{t} \]
        10. distribute-lft-out--85.5%

          \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{y \cdot \left(e^{z} - 1\right)}\right)}{t} \]
        11. expm1-define99.8%

          \[\leadsto x - \frac{\mathsf{log1p}\left(y \cdot \color{blue}{\mathsf{expm1}\left(z\right)}\right)}{t} \]
      3. Simplified99.8%

        \[\leadsto \color{blue}{x - \frac{\mathsf{log1p}\left(y \cdot \mathsf{expm1}\left(z\right)\right)}{t}} \]
      4. Add Preprocessing
      5. Step-by-step derivation
        1. clear-num99.7%

          \[\leadsto x - \color{blue}{\frac{1}{\frac{t}{\mathsf{log1p}\left(y \cdot \mathsf{expm1}\left(z\right)\right)}}} \]
        2. associate-/r/99.7%

          \[\leadsto x - \color{blue}{\frac{1}{t} \cdot \mathsf{log1p}\left(y \cdot \mathsf{expm1}\left(z\right)\right)} \]
      6. Applied egg-rr99.7%

        \[\leadsto x - \color{blue}{\frac{1}{t} \cdot \mathsf{log1p}\left(y \cdot \mathsf{expm1}\left(z\right)\right)} \]
      7. Step-by-step derivation
        1. associate-*l/99.8%

          \[\leadsto x - \color{blue}{\frac{1 \cdot \mathsf{log1p}\left(y \cdot \mathsf{expm1}\left(z\right)\right)}{t}} \]
        2. *-un-lft-identity99.8%

          \[\leadsto x - \frac{\color{blue}{\mathsf{log1p}\left(y \cdot \mathsf{expm1}\left(z\right)\right)}}{t} \]
        3. clear-num99.7%

          \[\leadsto x - \color{blue}{\frac{1}{\frac{t}{\mathsf{log1p}\left(y \cdot \mathsf{expm1}\left(z\right)\right)}}} \]
      8. Applied egg-rr99.7%

        \[\leadsto x - \color{blue}{\frac{1}{\frac{t}{\mathsf{log1p}\left(y \cdot \mathsf{expm1}\left(z\right)\right)}}} \]
      9. Taylor expanded in z around 0 67.5%

        \[\leadsto x - \frac{1}{\frac{t}{\mathsf{log1p}\left(\color{blue}{y \cdot z}\right)}} \]
      10. Taylor expanded in z around 0 66.4%

        \[\leadsto x - \frac{1}{\color{blue}{\frac{0.5 \cdot \left(t \cdot z\right) + \frac{t}{y}}{z}}} \]

      if -2.5e8 < y

      1. Initial program 70.3%

        \[x - \frac{\log \left(\left(1 - y\right) + y \cdot e^{z}\right)}{t} \]
      2. Step-by-step derivation
        1. associate-+l-79.4%

          \[\leadsto x - \frac{\log \color{blue}{\left(1 - \left(y - y \cdot e^{z}\right)\right)}}{t} \]
        2. sub-neg79.4%

          \[\leadsto x - \frac{\log \color{blue}{\left(1 + \left(-\left(y - y \cdot e^{z}\right)\right)\right)}}{t} \]
        3. log1p-define85.6%

          \[\leadsto x - \frac{\color{blue}{\mathsf{log1p}\left(-\left(y - y \cdot e^{z}\right)\right)}}{t} \]
        4. neg-sub085.6%

          \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{0 - \left(y - y \cdot e^{z}\right)}\right)}{t} \]
        5. associate-+l-85.6%

          \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{\left(0 - y\right) + y \cdot e^{z}}\right)}{t} \]
        6. neg-sub085.6%

          \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{\left(-y\right)} + y \cdot e^{z}\right)}{t} \]
        7. +-commutative85.6%

          \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{y \cdot e^{z} + \left(-y\right)}\right)}{t} \]
        8. unsub-neg85.6%

          \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{y \cdot e^{z} - y}\right)}{t} \]
        9. *-rgt-identity85.6%

          \[\leadsto x - \frac{\mathsf{log1p}\left(y \cdot e^{z} - \color{blue}{y \cdot 1}\right)}{t} \]
        10. distribute-lft-out--85.6%

          \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{y \cdot \left(e^{z} - 1\right)}\right)}{t} \]
        11. expm1-define98.4%

          \[\leadsto x - \frac{\mathsf{log1p}\left(y \cdot \color{blue}{\mathsf{expm1}\left(z\right)}\right)}{t} \]
      3. Simplified98.4%

        \[\leadsto \color{blue}{x - \frac{\mathsf{log1p}\left(y \cdot \mathsf{expm1}\left(z\right)\right)}{t}} \]
      4. Add Preprocessing
      5. Taylor expanded in y around 0 83.7%

        \[\leadsto x - \color{blue}{\frac{y \cdot \left(e^{z} - 1\right)}{t}} \]
      6. Step-by-step derivation
        1. associate-/l*83.7%

          \[\leadsto x - \color{blue}{y \cdot \frac{e^{z} - 1}{t}} \]
        2. expm1-define93.9%

          \[\leadsto x - y \cdot \frac{\color{blue}{\mathsf{expm1}\left(z\right)}}{t} \]
      7. Simplified93.9%

        \[\leadsto x - \color{blue}{y \cdot \frac{\mathsf{expm1}\left(z\right)}{t}} \]
    3. Recombined 2 regimes into one program.
    4. Final simplification86.2%

      \[\leadsto \begin{array}{l} \mathbf{if}\;y \leq -250000000:\\ \;\;\;\;x + \frac{-1}{\frac{0.5 \cdot \left(z \cdot t\right) + \frac{t}{y}}{z}}\\ \mathbf{else}:\\ \;\;\;\;x - y \cdot \frac{\mathsf{expm1}\left(z\right)}{t}\\ \end{array} \]
    5. Add Preprocessing

    Alternative 5: 90.7% accurate, 1.9× speedup?

    \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;z \leq -1.08 \cdot 10^{+71}:\\ \;\;\;\;x - \mathsf{expm1}\left(z\right) \cdot \frac{y}{t}\\ \mathbf{else}:\\ \;\;\;\;x - \frac{\mathsf{log1p}\left(y \cdot z\right)}{t}\\ \end{array} \end{array} \]
    (FPCore (x y z t)
     :precision binary64
     (if (<= z -1.08e+71) (- x (* (expm1 z) (/ y t))) (- x (/ (log1p (* y z)) t))))
    double code(double x, double y, double z, double t) {
    	double tmp;
    	if (z <= -1.08e+71) {
    		tmp = x - (expm1(z) * (y / t));
    	} else {
    		tmp = x - (log1p((y * z)) / t);
    	}
    	return tmp;
    }
    
    public static double code(double x, double y, double z, double t) {
    	double tmp;
    	if (z <= -1.08e+71) {
    		tmp = x - (Math.expm1(z) * (y / t));
    	} else {
    		tmp = x - (Math.log1p((y * z)) / t);
    	}
    	return tmp;
    }
    
    def code(x, y, z, t):
    	tmp = 0
    	if z <= -1.08e+71:
    		tmp = x - (math.expm1(z) * (y / t))
    	else:
    		tmp = x - (math.log1p((y * z)) / t)
    	return tmp
    
    function code(x, y, z, t)
    	tmp = 0.0
    	if (z <= -1.08e+71)
    		tmp = Float64(x - Float64(expm1(z) * Float64(y / t)));
    	else
    		tmp = Float64(x - Float64(log1p(Float64(y * z)) / t));
    	end
    	return tmp
    end
    
    code[x_, y_, z_, t_] := If[LessEqual[z, -1.08e+71], N[(x - N[(N[(Exp[z] - 1), $MachinePrecision] * N[(y / t), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(x - N[(N[Log[1 + N[(y * z), $MachinePrecision]], $MachinePrecision] / t), $MachinePrecision]), $MachinePrecision]]
    
    \begin{array}{l}
    
    \\
    \begin{array}{l}
    \mathbf{if}\;z \leq -1.08 \cdot 10^{+71}:\\
    \;\;\;\;x - \mathsf{expm1}\left(z\right) \cdot \frac{y}{t}\\
    
    \mathbf{else}:\\
    \;\;\;\;x - \frac{\mathsf{log1p}\left(y \cdot z\right)}{t}\\
    
    
    \end{array}
    \end{array}
    
    Derivation
    1. Split input into 2 regimes
    2. if z < -1.08e71

      1. Initial program 81.6%

        \[x - \frac{\log \left(\left(1 - y\right) + y \cdot e^{z}\right)}{t} \]
      2. Step-by-step derivation
        1. associate-+l-81.6%

          \[\leadsto x - \frac{\log \color{blue}{\left(1 - \left(y - y \cdot e^{z}\right)\right)}}{t} \]
        2. sub-neg81.6%

          \[\leadsto x - \frac{\log \color{blue}{\left(1 + \left(-\left(y - y \cdot e^{z}\right)\right)\right)}}{t} \]
        3. log1p-define99.9%

          \[\leadsto x - \frac{\color{blue}{\mathsf{log1p}\left(-\left(y - y \cdot e^{z}\right)\right)}}{t} \]
        4. neg-sub099.9%

          \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{0 - \left(y - y \cdot e^{z}\right)}\right)}{t} \]
        5. associate-+l-99.9%

          \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{\left(0 - y\right) + y \cdot e^{z}}\right)}{t} \]
        6. neg-sub099.9%

          \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{\left(-y\right)} + y \cdot e^{z}\right)}{t} \]
        7. +-commutative99.9%

          \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{y \cdot e^{z} + \left(-y\right)}\right)}{t} \]
        8. unsub-neg99.9%

          \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{y \cdot e^{z} - y}\right)}{t} \]
        9. *-rgt-identity99.9%

          \[\leadsto x - \frac{\mathsf{log1p}\left(y \cdot e^{z} - \color{blue}{y \cdot 1}\right)}{t} \]
        10. distribute-lft-out--99.9%

          \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{y \cdot \left(e^{z} - 1\right)}\right)}{t} \]
        11. expm1-define99.9%

          \[\leadsto x - \frac{\mathsf{log1p}\left(y \cdot \color{blue}{\mathsf{expm1}\left(z\right)}\right)}{t} \]
      3. Simplified99.9%

        \[\leadsto \color{blue}{x - \frac{\mathsf{log1p}\left(y \cdot \mathsf{expm1}\left(z\right)\right)}{t}} \]
      4. Add Preprocessing
      5. Taylor expanded in y around 0 75.5%

        \[\leadsto x - \color{blue}{\frac{y \cdot \left(e^{z} - 1\right)}{t}} \]
      6. Step-by-step derivation
        1. *-commutative75.5%

          \[\leadsto x - \frac{\color{blue}{\left(e^{z} - 1\right) \cdot y}}{t} \]
        2. associate-/l*75.5%

          \[\leadsto x - \color{blue}{\left(e^{z} - 1\right) \cdot \frac{y}{t}} \]
        3. expm1-define75.5%

          \[\leadsto x - \color{blue}{\mathsf{expm1}\left(z\right)} \cdot \frac{y}{t} \]
      7. Simplified75.5%

        \[\leadsto x - \color{blue}{\mathsf{expm1}\left(z\right) \cdot \frac{y}{t}} \]

      if -1.08e71 < z

      1. Initial program 59.4%

        \[x - \frac{\log \left(\left(1 - y\right) + y \cdot e^{z}\right)}{t} \]
      2. Step-by-step derivation
        1. associate-+l-81.0%

          \[\leadsto x - \frac{\log \color{blue}{\left(1 - \left(y - y \cdot e^{z}\right)\right)}}{t} \]
        2. sub-neg81.0%

          \[\leadsto x - \frac{\log \color{blue}{\left(1 + \left(-\left(y - y \cdot e^{z}\right)\right)\right)}}{t} \]
        3. log1p-define81.6%

          \[\leadsto x - \frac{\color{blue}{\mathsf{log1p}\left(-\left(y - y \cdot e^{z}\right)\right)}}{t} \]
        4. neg-sub081.6%

          \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{0 - \left(y - y \cdot e^{z}\right)}\right)}{t} \]
        5. associate-+l-81.6%

          \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{\left(0 - y\right) + y \cdot e^{z}}\right)}{t} \]
        6. neg-sub081.6%

          \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{\left(-y\right)} + y \cdot e^{z}\right)}{t} \]
        7. +-commutative81.6%

          \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{y \cdot e^{z} + \left(-y\right)}\right)}{t} \]
        8. unsub-neg81.6%

          \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{y \cdot e^{z} - y}\right)}{t} \]
        9. *-rgt-identity81.6%

          \[\leadsto x - \frac{\mathsf{log1p}\left(y \cdot e^{z} - \color{blue}{y \cdot 1}\right)}{t} \]
        10. distribute-lft-out--81.6%

          \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{y \cdot \left(e^{z} - 1\right)}\right)}{t} \]
        11. expm1-define98.4%

          \[\leadsto x - \frac{\mathsf{log1p}\left(y \cdot \color{blue}{\mathsf{expm1}\left(z\right)}\right)}{t} \]
      3. Simplified98.4%

        \[\leadsto \color{blue}{x - \frac{\mathsf{log1p}\left(y \cdot \mathsf{expm1}\left(z\right)\right)}{t}} \]
      4. Add Preprocessing
      5. Taylor expanded in z around 0 93.7%

        \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{y \cdot z}\right)}{t} \]
    3. Recombined 2 regimes into one program.
    4. Final simplification89.7%

      \[\leadsto \begin{array}{l} \mathbf{if}\;z \leq -1.08 \cdot 10^{+71}:\\ \;\;\;\;x - \mathsf{expm1}\left(z\right) \cdot \frac{y}{t}\\ \mathbf{else}:\\ \;\;\;\;x - \frac{\mathsf{log1p}\left(y \cdot z\right)}{t}\\ \end{array} \]
    5. Add Preprocessing

    Alternative 6: 81.0% accurate, 10.5× speedup?

    \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;z \leq -3 \cdot 10^{+88}:\\ \;\;\;\;x\\ \mathbf{else}:\\ \;\;\;\;x + \frac{-1}{\frac{0.5 \cdot \left(z \cdot t\right) + \frac{t}{y}}{z}}\\ \end{array} \end{array} \]
    (FPCore (x y z t)
     :precision binary64
     (if (<= z -3e+88) x (+ x (/ -1.0 (/ (+ (* 0.5 (* z t)) (/ t y)) z)))))
    double code(double x, double y, double z, double t) {
    	double tmp;
    	if (z <= -3e+88) {
    		tmp = x;
    	} else {
    		tmp = x + (-1.0 / (((0.5 * (z * t)) + (t / y)) / 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 (z <= (-3d+88)) then
            tmp = x
        else
            tmp = x + ((-1.0d0) / (((0.5d0 * (z * t)) + (t / y)) / z))
        end if
        code = tmp
    end function
    
    public static double code(double x, double y, double z, double t) {
    	double tmp;
    	if (z <= -3e+88) {
    		tmp = x;
    	} else {
    		tmp = x + (-1.0 / (((0.5 * (z * t)) + (t / y)) / z));
    	}
    	return tmp;
    }
    
    def code(x, y, z, t):
    	tmp = 0
    	if z <= -3e+88:
    		tmp = x
    	else:
    		tmp = x + (-1.0 / (((0.5 * (z * t)) + (t / y)) / z))
    	return tmp
    
    function code(x, y, z, t)
    	tmp = 0.0
    	if (z <= -3e+88)
    		tmp = x;
    	else
    		tmp = Float64(x + Float64(-1.0 / Float64(Float64(Float64(0.5 * Float64(z * t)) + Float64(t / y)) / z)));
    	end
    	return tmp
    end
    
    function tmp_2 = code(x, y, z, t)
    	tmp = 0.0;
    	if (z <= -3e+88)
    		tmp = x;
    	else
    		tmp = x + (-1.0 / (((0.5 * (z * t)) + (t / y)) / z));
    	end
    	tmp_2 = tmp;
    end
    
    code[x_, y_, z_, t_] := If[LessEqual[z, -3e+88], x, N[(x + N[(-1.0 / N[(N[(N[(0.5 * N[(z * t), $MachinePrecision]), $MachinePrecision] + N[(t / y), $MachinePrecision]), $MachinePrecision] / z), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
    
    \begin{array}{l}
    
    \\
    \begin{array}{l}
    \mathbf{if}\;z \leq -3 \cdot 10^{+88}:\\
    \;\;\;\;x\\
    
    \mathbf{else}:\\
    \;\;\;\;x + \frac{-1}{\frac{0.5 \cdot \left(z \cdot t\right) + \frac{t}{y}}{z}}\\
    
    
    \end{array}
    \end{array}
    
    Derivation
    1. Split input into 2 regimes
    2. if z < -3.00000000000000005e88

      1. Initial program 82.4%

        \[x - \frac{\log \left(\left(1 - y\right) + y \cdot e^{z}\right)}{t} \]
      2. Step-by-step derivation
        1. associate-+l-82.4%

          \[\leadsto x - \frac{\log \color{blue}{\left(1 - \left(y - y \cdot e^{z}\right)\right)}}{t} \]
        2. sub-neg82.4%

          \[\leadsto x - \frac{\log \color{blue}{\left(1 + \left(-\left(y - y \cdot e^{z}\right)\right)\right)}}{t} \]
        3. log1p-define100.0%

          \[\leadsto x - \frac{\color{blue}{\mathsf{log1p}\left(-\left(y - y \cdot e^{z}\right)\right)}}{t} \]
        4. neg-sub0100.0%

          \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{0 - \left(y - y \cdot e^{z}\right)}\right)}{t} \]
        5. associate-+l-100.0%

          \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{\left(0 - y\right) + y \cdot e^{z}}\right)}{t} \]
        6. neg-sub0100.0%

          \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{\left(-y\right)} + y \cdot e^{z}\right)}{t} \]
        7. +-commutative100.0%

          \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{y \cdot e^{z} + \left(-y\right)}\right)}{t} \]
        8. unsub-neg100.0%

          \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{y \cdot e^{z} - y}\right)}{t} \]
        9. *-rgt-identity100.0%

          \[\leadsto x - \frac{\mathsf{log1p}\left(y \cdot e^{z} - \color{blue}{y \cdot 1}\right)}{t} \]
        10. distribute-lft-out--100.0%

          \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{y \cdot \left(e^{z} - 1\right)}\right)}{t} \]
        11. expm1-define100.0%

          \[\leadsto x - \frac{\mathsf{log1p}\left(y \cdot \color{blue}{\mathsf{expm1}\left(z\right)}\right)}{t} \]
      3. Simplified100.0%

        \[\leadsto \color{blue}{x - \frac{\mathsf{log1p}\left(y \cdot \mathsf{expm1}\left(z\right)\right)}{t}} \]
      4. Add Preprocessing
      5. Taylor expanded in x around inf 60.0%

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

      if -3.00000000000000005e88 < z

      1. Initial program 59.7%

        \[x - \frac{\log \left(\left(1 - y\right) + y \cdot e^{z}\right)}{t} \]
      2. Step-by-step derivation
        1. associate-+l-80.8%

          \[\leadsto x - \frac{\log \color{blue}{\left(1 - \left(y - y \cdot e^{z}\right)\right)}}{t} \]
        2. sub-neg80.8%

          \[\leadsto x - \frac{\log \color{blue}{\left(1 + \left(-\left(y - y \cdot e^{z}\right)\right)\right)}}{t} \]
        3. log1p-define82.0%

          \[\leadsto x - \frac{\color{blue}{\mathsf{log1p}\left(-\left(y - y \cdot e^{z}\right)\right)}}{t} \]
        4. neg-sub082.0%

          \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{0 - \left(y - y \cdot e^{z}\right)}\right)}{t} \]
        5. associate-+l-82.0%

          \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{\left(0 - y\right) + y \cdot e^{z}}\right)}{t} \]
        6. neg-sub082.0%

          \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{\left(-y\right)} + y \cdot e^{z}\right)}{t} \]
        7. +-commutative82.0%

          \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{y \cdot e^{z} + \left(-y\right)}\right)}{t} \]
        8. unsub-neg82.0%

          \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{y \cdot e^{z} - y}\right)}{t} \]
        9. *-rgt-identity82.0%

          \[\leadsto x - \frac{\mathsf{log1p}\left(y \cdot e^{z} - \color{blue}{y \cdot 1}\right)}{t} \]
        10. distribute-lft-out--82.0%

          \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{y \cdot \left(e^{z} - 1\right)}\right)}{t} \]
        11. expm1-define98.5%

          \[\leadsto x - \frac{\mathsf{log1p}\left(y \cdot \color{blue}{\mathsf{expm1}\left(z\right)}\right)}{t} \]
      3. Simplified98.5%

        \[\leadsto \color{blue}{x - \frac{\mathsf{log1p}\left(y \cdot \mathsf{expm1}\left(z\right)\right)}{t}} \]
      4. Add Preprocessing
      5. Step-by-step derivation
        1. clear-num98.4%

          \[\leadsto x - \color{blue}{\frac{1}{\frac{t}{\mathsf{log1p}\left(y \cdot \mathsf{expm1}\left(z\right)\right)}}} \]
        2. associate-/r/98.4%

          \[\leadsto x - \color{blue}{\frac{1}{t} \cdot \mathsf{log1p}\left(y \cdot \mathsf{expm1}\left(z\right)\right)} \]
      6. Applied egg-rr98.4%

        \[\leadsto x - \color{blue}{\frac{1}{t} \cdot \mathsf{log1p}\left(y \cdot \mathsf{expm1}\left(z\right)\right)} \]
      7. Step-by-step derivation
        1. associate-*l/98.5%

          \[\leadsto x - \color{blue}{\frac{1 \cdot \mathsf{log1p}\left(y \cdot \mathsf{expm1}\left(z\right)\right)}{t}} \]
        2. *-un-lft-identity98.5%

          \[\leadsto x - \frac{\color{blue}{\mathsf{log1p}\left(y \cdot \mathsf{expm1}\left(z\right)\right)}}{t} \]
        3. clear-num98.4%

          \[\leadsto x - \color{blue}{\frac{1}{\frac{t}{\mathsf{log1p}\left(y \cdot \mathsf{expm1}\left(z\right)\right)}}} \]
      8. Applied egg-rr98.4%

        \[\leadsto x - \color{blue}{\frac{1}{\frac{t}{\mathsf{log1p}\left(y \cdot \mathsf{expm1}\left(z\right)\right)}}} \]
      9. Taylor expanded in z around 0 92.0%

        \[\leadsto x - \frac{1}{\frac{t}{\mathsf{log1p}\left(\color{blue}{y \cdot z}\right)}} \]
      10. Taylor expanded in z around 0 85.9%

        \[\leadsto x - \frac{1}{\color{blue}{\frac{0.5 \cdot \left(t \cdot z\right) + \frac{t}{y}}{z}}} \]
    3. Recombined 2 regimes into one program.
    4. Final simplification80.7%

      \[\leadsto \begin{array}{l} \mathbf{if}\;z \leq -3 \cdot 10^{+88}:\\ \;\;\;\;x\\ \mathbf{else}:\\ \;\;\;\;x + \frac{-1}{\frac{0.5 \cdot \left(z \cdot t\right) + \frac{t}{y}}{z}}\\ \end{array} \]
    5. Add Preprocessing

    Alternative 7: 82.1% accurate, 17.6× speedup?

    \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;z \leq -3.25 \cdot 10^{-7}:\\ \;\;\;\;x\\ \mathbf{else}:\\ \;\;\;\;x - y \cdot \frac{z}{t}\\ \end{array} \end{array} \]
    (FPCore (x y z t)
     :precision binary64
     (if (<= z -3.25e-7) x (- x (* y (/ z t)))))
    double code(double x, double y, double z, double t) {
    	double tmp;
    	if (z <= -3.25e-7) {
    		tmp = x;
    	} else {
    		tmp = x - (y * (z / t));
    	}
    	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 (z <= (-3.25d-7)) then
            tmp = x
        else
            tmp = x - (y * (z / t))
        end if
        code = tmp
    end function
    
    public static double code(double x, double y, double z, double t) {
    	double tmp;
    	if (z <= -3.25e-7) {
    		tmp = x;
    	} else {
    		tmp = x - (y * (z / t));
    	}
    	return tmp;
    }
    
    def code(x, y, z, t):
    	tmp = 0
    	if z <= -3.25e-7:
    		tmp = x
    	else:
    		tmp = x - (y * (z / t))
    	return tmp
    
    function code(x, y, z, t)
    	tmp = 0.0
    	if (z <= -3.25e-7)
    		tmp = x;
    	else
    		tmp = Float64(x - Float64(y * Float64(z / t)));
    	end
    	return tmp
    end
    
    function tmp_2 = code(x, y, z, t)
    	tmp = 0.0;
    	if (z <= -3.25e-7)
    		tmp = x;
    	else
    		tmp = x - (y * (z / t));
    	end
    	tmp_2 = tmp;
    end
    
    code[x_, y_, z_, t_] := If[LessEqual[z, -3.25e-7], x, N[(x - N[(y * N[(z / t), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
    
    \begin{array}{l}
    
    \\
    \begin{array}{l}
    \mathbf{if}\;z \leq -3.25 \cdot 10^{-7}:\\
    \;\;\;\;x\\
    
    \mathbf{else}:\\
    \;\;\;\;x - y \cdot \frac{z}{t}\\
    
    
    \end{array}
    \end{array}
    
    Derivation
    1. Split input into 2 regimes
    2. if z < -3.25000000000000012e-7

      1. Initial program 86.6%

        \[x - \frac{\log \left(\left(1 - y\right) + y \cdot e^{z}\right)}{t} \]
      2. Step-by-step derivation
        1. associate-+l-86.6%

          \[\leadsto x - \frac{\log \color{blue}{\left(1 - \left(y - y \cdot e^{z}\right)\right)}}{t} \]
        2. sub-neg86.6%

          \[\leadsto x - \frac{\log \color{blue}{\left(1 + \left(-\left(y - y \cdot e^{z}\right)\right)\right)}}{t} \]
        3. log1p-define99.9%

          \[\leadsto x - \frac{\color{blue}{\mathsf{log1p}\left(-\left(y - y \cdot e^{z}\right)\right)}}{t} \]
        4. neg-sub099.9%

          \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{0 - \left(y - y \cdot e^{z}\right)}\right)}{t} \]
        5. associate-+l-99.9%

          \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{\left(0 - y\right) + y \cdot e^{z}}\right)}{t} \]
        6. neg-sub099.9%

          \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{\left(-y\right)} + y \cdot e^{z}\right)}{t} \]
        7. +-commutative99.9%

          \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{y \cdot e^{z} + \left(-y\right)}\right)}{t} \]
        8. unsub-neg99.9%

          \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{y \cdot e^{z} - y}\right)}{t} \]
        9. *-rgt-identity99.9%

          \[\leadsto x - \frac{\mathsf{log1p}\left(y \cdot e^{z} - \color{blue}{y \cdot 1}\right)}{t} \]
        10. distribute-lft-out--99.9%

          \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{y \cdot \left(e^{z} - 1\right)}\right)}{t} \]
        11. expm1-define99.9%

          \[\leadsto x - \frac{\mathsf{log1p}\left(y \cdot \color{blue}{\mathsf{expm1}\left(z\right)}\right)}{t} \]
      3. Simplified99.9%

        \[\leadsto \color{blue}{x - \frac{\mathsf{log1p}\left(y \cdot \mathsf{expm1}\left(z\right)\right)}{t}} \]
      4. Add Preprocessing
      5. Taylor expanded in x around inf 61.8%

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

      if -3.25000000000000012e-7 < z

      1. Initial program 52.9%

        \[x - \frac{\log \left(\left(1 - y\right) + y \cdot e^{z}\right)}{t} \]
      2. Step-by-step derivation
        1. associate-+l-78.4%

          \[\leadsto x - \frac{\log \color{blue}{\left(1 - \left(y - y \cdot e^{z}\right)\right)}}{t} \]
        2. sub-neg78.4%

          \[\leadsto x - \frac{\log \color{blue}{\left(1 + \left(-\left(y - y \cdot e^{z}\right)\right)\right)}}{t} \]
        3. log1p-define78.4%

          \[\leadsto x - \frac{\color{blue}{\mathsf{log1p}\left(-\left(y - y \cdot e^{z}\right)\right)}}{t} \]
        4. neg-sub078.4%

          \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{0 - \left(y - y \cdot e^{z}\right)}\right)}{t} \]
        5. associate-+l-78.4%

          \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{\left(0 - y\right) + y \cdot e^{z}}\right)}{t} \]
        6. neg-sub078.4%

          \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{\left(-y\right)} + y \cdot e^{z}\right)}{t} \]
        7. +-commutative78.4%

          \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{y \cdot e^{z} + \left(-y\right)}\right)}{t} \]
        8. unsub-neg78.4%

          \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{y \cdot e^{z} - y}\right)}{t} \]
        9. *-rgt-identity78.4%

          \[\leadsto x - \frac{\mathsf{log1p}\left(y \cdot e^{z} - \color{blue}{y \cdot 1}\right)}{t} \]
        10. distribute-lft-out--78.4%

          \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{y \cdot \left(e^{z} - 1\right)}\right)}{t} \]
        11. expm1-define98.2%

          \[\leadsto x - \frac{\mathsf{log1p}\left(y \cdot \color{blue}{\mathsf{expm1}\left(z\right)}\right)}{t} \]
      3. Simplified98.2%

        \[\leadsto \color{blue}{x - \frac{\mathsf{log1p}\left(y \cdot \mathsf{expm1}\left(z\right)\right)}{t}} \]
      4. Add Preprocessing
      5. Taylor expanded in z around 0 88.5%

        \[\leadsto x - \color{blue}{\frac{y \cdot z}{t}} \]
      6. Step-by-step derivation
        1. associate-/l*90.2%

          \[\leadsto x - \color{blue}{y \cdot \frac{z}{t}} \]
      7. Simplified90.2%

        \[\leadsto x - \color{blue}{y \cdot \frac{z}{t}} \]
    3. Recombined 2 regimes into one program.
    4. Final simplification80.7%

      \[\leadsto \begin{array}{l} \mathbf{if}\;z \leq -3.25 \cdot 10^{-7}:\\ \;\;\;\;x\\ \mathbf{else}:\\ \;\;\;\;x - y \cdot \frac{z}{t}\\ \end{array} \]
    5. Add Preprocessing

    Alternative 8: 71.4% accurate, 211.0× 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 64.2%

      \[x - \frac{\log \left(\left(1 - y\right) + y \cdot e^{z}\right)}{t} \]
    2. Step-by-step derivation
      1. associate-+l-81.1%

        \[\leadsto x - \frac{\log \color{blue}{\left(1 - \left(y - y \cdot e^{z}\right)\right)}}{t} \]
      2. sub-neg81.1%

        \[\leadsto x - \frac{\log \color{blue}{\left(1 + \left(-\left(y - y \cdot e^{z}\right)\right)\right)}}{t} \]
      3. log1p-define85.6%

        \[\leadsto x - \frac{\color{blue}{\mathsf{log1p}\left(-\left(y - y \cdot e^{z}\right)\right)}}{t} \]
      4. neg-sub085.6%

        \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{0 - \left(y - y \cdot e^{z}\right)}\right)}{t} \]
      5. associate-+l-85.6%

        \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{\left(0 - y\right) + y \cdot e^{z}}\right)}{t} \]
      6. neg-sub085.6%

        \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{\left(-y\right)} + y \cdot e^{z}\right)}{t} \]
      7. +-commutative85.6%

        \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{y \cdot e^{z} + \left(-y\right)}\right)}{t} \]
      8. unsub-neg85.6%

        \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{y \cdot e^{z} - y}\right)}{t} \]
      9. *-rgt-identity85.6%

        \[\leadsto x - \frac{\mathsf{log1p}\left(y \cdot e^{z} - \color{blue}{y \cdot 1}\right)}{t} \]
      10. distribute-lft-out--85.6%

        \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{y \cdot \left(e^{z} - 1\right)}\right)}{t} \]
      11. expm1-define98.8%

        \[\leadsto x - \frac{\mathsf{log1p}\left(y \cdot \color{blue}{\mathsf{expm1}\left(z\right)}\right)}{t} \]
    3. Simplified98.8%

      \[\leadsto \color{blue}{x - \frac{\mathsf{log1p}\left(y \cdot \mathsf{expm1}\left(z\right)\right)}{t}} \]
    4. Add Preprocessing
    5. Taylor expanded in x around inf 72.0%

      \[\leadsto \color{blue}{x} \]
    6. Final simplification72.0%

      \[\leadsto x \]
    7. Add Preprocessing

    Developer target: 75.5% accurate, 1.9× speedup?

    \[\begin{array}{l} \\ \begin{array}{l} t_1 := \frac{-0.5}{y \cdot t}\\ \mathbf{if}\;z < -2.8874623088207947 \cdot 10^{+119}:\\ \;\;\;\;\left(x - \frac{t\_1}{z \cdot z}\right) - t\_1 \cdot \frac{\frac{2}{z}}{z \cdot z}\\ \mathbf{else}:\\ \;\;\;\;x - \frac{\log \left(1 + z \cdot y\right)}{t}\\ \end{array} \end{array} \]
    (FPCore (x y z t)
     :precision binary64
     (let* ((t_1 (/ (- 0.5) (* y t))))
       (if (< z -2.8874623088207947e+119)
         (- (- x (/ t_1 (* z z))) (* t_1 (/ (/ 2.0 z) (* z z))))
         (- x (/ (log (+ 1.0 (* z y))) t)))))
    double code(double x, double y, double z, double t) {
    	double t_1 = -0.5 / (y * t);
    	double tmp;
    	if (z < -2.8874623088207947e+119) {
    		tmp = (x - (t_1 / (z * z))) - (t_1 * ((2.0 / z) / (z * z)));
    	} else {
    		tmp = x - (log((1.0 + (z * y))) / t);
    	}
    	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 = -0.5d0 / (y * t)
        if (z < (-2.8874623088207947d+119)) then
            tmp = (x - (t_1 / (z * z))) - (t_1 * ((2.0d0 / z) / (z * z)))
        else
            tmp = x - (log((1.0d0 + (z * y))) / t)
        end if
        code = tmp
    end function
    
    public static double code(double x, double y, double z, double t) {
    	double t_1 = -0.5 / (y * t);
    	double tmp;
    	if (z < -2.8874623088207947e+119) {
    		tmp = (x - (t_1 / (z * z))) - (t_1 * ((2.0 / z) / (z * z)));
    	} else {
    		tmp = x - (Math.log((1.0 + (z * y))) / t);
    	}
    	return tmp;
    }
    
    def code(x, y, z, t):
    	t_1 = -0.5 / (y * t)
    	tmp = 0
    	if z < -2.8874623088207947e+119:
    		tmp = (x - (t_1 / (z * z))) - (t_1 * ((2.0 / z) / (z * z)))
    	else:
    		tmp = x - (math.log((1.0 + (z * y))) / t)
    	return tmp
    
    function code(x, y, z, t)
    	t_1 = Float64(Float64(-0.5) / Float64(y * t))
    	tmp = 0.0
    	if (z < -2.8874623088207947e+119)
    		tmp = Float64(Float64(x - Float64(t_1 / Float64(z * z))) - Float64(t_1 * Float64(Float64(2.0 / z) / Float64(z * z))));
    	else
    		tmp = Float64(x - Float64(log(Float64(1.0 + Float64(z * y))) / t));
    	end
    	return tmp
    end
    
    function tmp_2 = code(x, y, z, t)
    	t_1 = -0.5 / (y * t);
    	tmp = 0.0;
    	if (z < -2.8874623088207947e+119)
    		tmp = (x - (t_1 / (z * z))) - (t_1 * ((2.0 / z) / (z * z)));
    	else
    		tmp = x - (log((1.0 + (z * y))) / t);
    	end
    	tmp_2 = tmp;
    end
    
    code[x_, y_, z_, t_] := Block[{t$95$1 = N[((-0.5) / N[(y * t), $MachinePrecision]), $MachinePrecision]}, If[Less[z, -2.8874623088207947e+119], N[(N[(x - N[(t$95$1 / N[(z * z), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] - N[(t$95$1 * N[(N[(2.0 / z), $MachinePrecision] / N[(z * z), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(x - N[(N[Log[N[(1.0 + N[(z * y), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] / t), $MachinePrecision]), $MachinePrecision]]]
    
    \begin{array}{l}
    
    \\
    \begin{array}{l}
    t_1 := \frac{-0.5}{y \cdot t}\\
    \mathbf{if}\;z < -2.8874623088207947 \cdot 10^{+119}:\\
    \;\;\;\;\left(x - \frac{t\_1}{z \cdot z}\right) - t\_1 \cdot \frac{\frac{2}{z}}{z \cdot z}\\
    
    \mathbf{else}:\\
    \;\;\;\;x - \frac{\log \left(1 + z \cdot y\right)}{t}\\
    
    
    \end{array}
    \end{array}
    

    Reproduce

    ?
    herbie shell --seed 2024115 
    (FPCore (x y z t)
      :name "System.Random.MWC.Distributions:truncatedExp from mwc-random-0.13.3.2"
      :precision binary64
    
      :alt
      (if (< z -2.8874623088207947e+119) (- (- x (/ (/ (- 0.5) (* y t)) (* z z))) (* (/ (- 0.5) (* y t)) (/ (/ 2.0 z) (* z z)))) (- x (/ (log (+ 1.0 (* z y))) t)))
    
      (- x (/ (log (+ (- 1.0 y) (* y (exp z)))) t)))