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

Percentage Accurate: 61.0% → 98.3%
Time: 20.3s
Alternatives: 7
Speedup: 30.1×

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 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: 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: 98.3% 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 60.5%

    \[x - \frac{\log \left(\left(1 - y\right) + y \cdot e^{z}\right)}{t} \]
  2. Step-by-step derivation
    1. associate-+l-77.5%

      \[\leadsto x - \frac{\log \color{blue}{\left(1 - \left(y - y \cdot e^{z}\right)\right)}}{t} \]
    2. sub-neg77.5%

      \[\leadsto x - \frac{\log \color{blue}{\left(1 + \left(-\left(y - y \cdot e^{z}\right)\right)\right)}}{t} \]
    3. log1p-define82.8%

      \[\leadsto x - \frac{\color{blue}{\mathsf{log1p}\left(-\left(y - y \cdot e^{z}\right)\right)}}{t} \]
    4. neg-sub082.8%

      \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{0 - \left(y - y \cdot e^{z}\right)}\right)}{t} \]
    5. associate-+l-82.8%

      \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{\left(0 - y\right) + y \cdot e^{z}}\right)}{t} \]
    6. neg-sub082.8%

      \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{\left(-y\right)} + y \cdot e^{z}\right)}{t} \]
    7. +-commutative82.8%

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

      \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{y \cdot e^{z} - y}\right)}{t} \]
    9. *-rgt-identity82.8%

      \[\leadsto x - \frac{\mathsf{log1p}\left(y \cdot e^{z} - \color{blue}{y \cdot 1}\right)}{t} \]
    10. distribute-lft-out--82.8%

      \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{y \cdot \left(e^{z} - 1\right)}\right)}{t} \]
    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. Add Preprocessing

Alternative 2: 91.9% accurate, 0.9× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;e^{z} \leq 0:\\ \;\;\;\;x - \frac{y \cdot \mathsf{expm1}\left(z\right)}{t}\\ \mathbf{else}:\\ \;\;\;\;x - \frac{\mathsf{log1p}\left(z \cdot \left(y + z \cdot \left(0.16666666666666666 \cdot \left(y \cdot z\right) + y \cdot 0.5\right)\right)\right)}{t}\\ \end{array} \end{array} \]
(FPCore (x y z t)
 :precision binary64
 (if (<= (exp z) 0.0)
   (- x (/ (* y (expm1 z)) t))
   (-
    x
    (/
     (log1p (* z (+ y (* z (+ (* 0.16666666666666666 (* y z)) (* y 0.5))))))
     t))))
double code(double x, double y, double z, double t) {
	double tmp;
	if (exp(z) <= 0.0) {
		tmp = x - ((y * expm1(z)) / t);
	} else {
		tmp = x - (log1p((z * (y + (z * ((0.16666666666666666 * (y * z)) + (y * 0.5)))))) / t);
	}
	return tmp;
}
public static double code(double x, double y, double z, double t) {
	double tmp;
	if (Math.exp(z) <= 0.0) {
		tmp = x - ((y * Math.expm1(z)) / t);
	} else {
		tmp = x - (Math.log1p((z * (y + (z * ((0.16666666666666666 * (y * z)) + (y * 0.5)))))) / t);
	}
	return tmp;
}
def code(x, y, z, t):
	tmp = 0
	if math.exp(z) <= 0.0:
		tmp = x - ((y * math.expm1(z)) / t)
	else:
		tmp = x - (math.log1p((z * (y + (z * ((0.16666666666666666 * (y * z)) + (y * 0.5)))))) / t)
	return tmp
function code(x, y, z, t)
	tmp = 0.0
	if (exp(z) <= 0.0)
		tmp = Float64(x - Float64(Float64(y * expm1(z)) / t));
	else
		tmp = Float64(x - Float64(log1p(Float64(z * Float64(y + Float64(z * Float64(Float64(0.16666666666666666 * Float64(y * z)) + Float64(y * 0.5)))))) / t));
	end
	return tmp
end
code[x_, y_, z_, t_] := If[LessEqual[N[Exp[z], $MachinePrecision], 0.0], N[(x - N[(N[(y * N[(Exp[z] - 1), $MachinePrecision]), $MachinePrecision] / t), $MachinePrecision]), $MachinePrecision], N[(x - N[(N[Log[1 + N[(z * N[(y + N[(z * N[(N[(0.16666666666666666 * N[(y * z), $MachinePrecision]), $MachinePrecision] + N[(y * 0.5), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] / t), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;e^{z} \leq 0:\\
\;\;\;\;x - \frac{y \cdot \mathsf{expm1}\left(z\right)}{t}\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (exp.f64 z) < 0.0

    1. Initial program 81.4%

      \[x - \frac{\log \left(\left(1 - y\right) + y \cdot e^{z}\right)}{t} \]
    2. Step-by-step derivation
      1. associate-+l-81.4%

        \[\leadsto x - \frac{\log \color{blue}{\left(1 - \left(y - y \cdot e^{z}\right)\right)}}{t} \]
      2. sub-neg81.4%

        \[\leadsto x - \frac{\log \color{blue}{\left(1 + \left(-\left(y - y \cdot e^{z}\right)\right)\right)}}{t} \]
      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 y around 0 82.7%

      \[\leadsto x - \frac{\color{blue}{y \cdot \left(e^{z} - 1\right)}}{t} \]
    6. Step-by-step derivation
      1. expm1-define82.7%

        \[\leadsto x - \frac{y \cdot \color{blue}{\mathsf{expm1}\left(z\right)}}{t} \]
    7. Simplified82.7%

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

    if 0.0 < (exp.f64 z)

    1. Initial program 53.2%

      \[x - \frac{\log \left(\left(1 - y\right) + y \cdot e^{z}\right)}{t} \]
    2. Step-by-step derivation
      1. associate-+l-76.1%

        \[\leadsto x - \frac{\log \color{blue}{\left(1 - \left(y - y \cdot e^{z}\right)\right)}}{t} \]
      2. sub-neg76.1%

        \[\leadsto x - \frac{\log \color{blue}{\left(1 + \left(-\left(y - y \cdot e^{z}\right)\right)\right)}}{t} \]
      3. log1p-define76.9%

        \[\leadsto x - \frac{\color{blue}{\mathsf{log1p}\left(-\left(y - y \cdot e^{z}\right)\right)}}{t} \]
      4. neg-sub076.9%

        \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{0 - \left(y - y \cdot e^{z}\right)}\right)}{t} \]
      5. associate-+l-76.9%

        \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{\left(0 - y\right) + y \cdot e^{z}}\right)}{t} \]
      6. neg-sub076.9%

        \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{\left(-y\right)} + y \cdot e^{z}\right)}{t} \]
      7. +-commutative76.9%

        \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{y \cdot e^{z} + \left(-y\right)}\right)}{t} \]
      8. unsub-neg76.9%

        \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{y \cdot e^{z} - y}\right)}{t} \]
      9. *-rgt-identity76.9%

        \[\leadsto x - \frac{\mathsf{log1p}\left(y \cdot e^{z} - \color{blue}{y \cdot 1}\right)}{t} \]
      10. distribute-lft-out--76.9%

        \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{y \cdot \left(e^{z} - 1\right)}\right)}{t} \]
      11. expm1-define97.7%

        \[\leadsto x - \frac{\mathsf{log1p}\left(y \cdot \color{blue}{\mathsf{expm1}\left(z\right)}\right)}{t} \]
    3. Simplified97.7%

      \[\leadsto \color{blue}{x - \frac{\mathsf{log1p}\left(y \cdot \mathsf{expm1}\left(z\right)\right)}{t}} \]
    4. Add Preprocessing
    5. Taylor expanded in z around 0 98.2%

      \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{z \cdot \left(y + z \cdot \left(0.16666666666666666 \cdot \left(y \cdot z\right) + 0.5 \cdot y\right)\right)}\right)}{t} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification94.2%

    \[\leadsto \begin{array}{l} \mathbf{if}\;e^{z} \leq 0:\\ \;\;\;\;x - \frac{y \cdot \mathsf{expm1}\left(z\right)}{t}\\ \mathbf{else}:\\ \;\;\;\;x - \frac{\mathsf{log1p}\left(z \cdot \left(y + z \cdot \left(0.16666666666666666 \cdot \left(y \cdot z\right) + y \cdot 0.5\right)\right)\right)}{t}\\ \end{array} \]
  5. Add Preprocessing

Alternative 3: 91.7% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;e^{z} \leq 0.99999996:\\ \;\;\;\;x - \frac{y \cdot \mathsf{expm1}\left(z\right)}{t}\\ \mathbf{else}:\\ \;\;\;\;x - \frac{\mathsf{log1p}\left(z \cdot \left(y + \left(y \cdot z\right) \cdot 0.5\right)\right)}{t}\\ \end{array} \end{array} \]
(FPCore (x y z t)
 :precision binary64
 (if (<= (exp z) 0.99999996)
   (- x (/ (* y (expm1 z)) t))
   (- x (/ (log1p (* z (+ y (* (* y z) 0.5)))) t))))
double code(double x, double y, double z, double t) {
	double tmp;
	if (exp(z) <= 0.99999996) {
		tmp = x - ((y * expm1(z)) / t);
	} else {
		tmp = x - (log1p((z * (y + ((y * z) * 0.5)))) / t);
	}
	return tmp;
}
public static double code(double x, double y, double z, double t) {
	double tmp;
	if (Math.exp(z) <= 0.99999996) {
		tmp = x - ((y * Math.expm1(z)) / t);
	} else {
		tmp = x - (Math.log1p((z * (y + ((y * z) * 0.5)))) / t);
	}
	return tmp;
}
def code(x, y, z, t):
	tmp = 0
	if math.exp(z) <= 0.99999996:
		tmp = x - ((y * math.expm1(z)) / t)
	else:
		tmp = x - (math.log1p((z * (y + ((y * z) * 0.5)))) / t)
	return tmp
function code(x, y, z, t)
	tmp = 0.0
	if (exp(z) <= 0.99999996)
		tmp = Float64(x - Float64(Float64(y * expm1(z)) / t));
	else
		tmp = Float64(x - Float64(log1p(Float64(z * Float64(y + Float64(Float64(y * z) * 0.5)))) / t));
	end
	return tmp
end
code[x_, y_, z_, t_] := If[LessEqual[N[Exp[z], $MachinePrecision], 0.99999996], N[(x - N[(N[(y * N[(Exp[z] - 1), $MachinePrecision]), $MachinePrecision] / t), $MachinePrecision]), $MachinePrecision], N[(x - N[(N[Log[1 + N[(z * N[(y + N[(N[(y * z), $MachinePrecision] * 0.5), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] / t), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;e^{z} \leq 0.99999996:\\
\;\;\;\;x - \frac{y \cdot \mathsf{expm1}\left(z\right)}{t}\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (exp.f64 z) < 0.99999996000000002

    1. Initial program 80.9%

      \[x - \frac{\log \left(\left(1 - y\right) + y \cdot e^{z}\right)}{t} \]
    2. Step-by-step derivation
      1. associate-+l-80.9%

        \[\leadsto x - \frac{\log \color{blue}{\left(1 - \left(y - y \cdot e^{z}\right)\right)}}{t} \]
      2. sub-neg80.9%

        \[\leadsto x - \frac{\log \color{blue}{\left(1 + \left(-\left(y - y \cdot e^{z}\right)\right)\right)}}{t} \]
      3. log1p-define99.5%

        \[\leadsto x - \frac{\color{blue}{\mathsf{log1p}\left(-\left(y - y \cdot e^{z}\right)\right)}}{t} \]
      4. neg-sub099.5%

        \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{0 - \left(y - y \cdot e^{z}\right)}\right)}{t} \]
      5. associate-+l-99.5%

        \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{\left(0 - y\right) + y \cdot e^{z}}\right)}{t} \]
      6. neg-sub099.5%

        \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{\left(-y\right)} + y \cdot e^{z}\right)}{t} \]
      7. +-commutative99.5%

        \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{y \cdot e^{z} + \left(-y\right)}\right)}{t} \]
      8. unsub-neg99.5%

        \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{y \cdot e^{z} - y}\right)}{t} \]
      9. *-rgt-identity99.5%

        \[\leadsto x - \frac{\mathsf{log1p}\left(y \cdot e^{z} - \color{blue}{y \cdot 1}\right)}{t} \]
      10. distribute-lft-out--99.5%

        \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{y \cdot \left(e^{z} - 1\right)}\right)}{t} \]
      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 y around 0 83.0%

      \[\leadsto x - \frac{\color{blue}{y \cdot \left(e^{z} - 1\right)}}{t} \]
    6. Step-by-step derivation
      1. expm1-define83.4%

        \[\leadsto x - \frac{y \cdot \color{blue}{\mathsf{expm1}\left(z\right)}}{t} \]
    7. Simplified83.4%

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

    if 0.99999996000000002 < (exp.f64 z)

    1. Initial program 53.0%

      \[x - \frac{\log \left(\left(1 - y\right) + y \cdot e^{z}\right)}{t} \]
    2. Step-by-step derivation
      1. associate-+l-76.2%

        \[\leadsto x - \frac{\log \color{blue}{\left(1 - \left(y - y \cdot e^{z}\right)\right)}}{t} \]
      2. sub-neg76.2%

        \[\leadsto x - \frac{\log \color{blue}{\left(1 + \left(-\left(y - y \cdot e^{z}\right)\right)\right)}}{t} \]
      3. log1p-define76.7%

        \[\leadsto x - \frac{\color{blue}{\mathsf{log1p}\left(-\left(y - y \cdot e^{z}\right)\right)}}{t} \]
      4. neg-sub076.7%

        \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{0 - \left(y - y \cdot e^{z}\right)}\right)}{t} \]
      5. associate-+l-76.7%

        \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{\left(0 - y\right) + y \cdot e^{z}}\right)}{t} \]
      6. neg-sub076.7%

        \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{\left(-y\right)} + y \cdot e^{z}\right)}{t} \]
      7. +-commutative76.7%

        \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{y \cdot e^{z} + \left(-y\right)}\right)}{t} \]
      8. unsub-neg76.7%

        \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{y \cdot e^{z} - y}\right)}{t} \]
      9. *-rgt-identity76.7%

        \[\leadsto x - \frac{\mathsf{log1p}\left(y \cdot e^{z} - \color{blue}{y \cdot 1}\right)}{t} \]
      10. distribute-lft-out--76.7%

        \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{y \cdot \left(e^{z} - 1\right)}\right)}{t} \]
      11. expm1-define97.6%

        \[\leadsto x - \frac{\mathsf{log1p}\left(y \cdot \color{blue}{\mathsf{expm1}\left(z\right)}\right)}{t} \]
    3. Simplified97.6%

      \[\leadsto \color{blue}{x - \frac{\mathsf{log1p}\left(y \cdot \mathsf{expm1}\left(z\right)\right)}{t}} \]
    4. Add Preprocessing
    5. Taylor expanded in z around 0 98.2%

      \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{z \cdot \left(y + 0.5 \cdot \left(y \cdot z\right)\right)}\right)}{t} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification94.2%

    \[\leadsto \begin{array}{l} \mathbf{if}\;e^{z} \leq 0.99999996:\\ \;\;\;\;x - \frac{y \cdot \mathsf{expm1}\left(z\right)}{t}\\ \mathbf{else}:\\ \;\;\;\;x - \frac{\mathsf{log1p}\left(z \cdot \left(y + \left(y \cdot z\right) \cdot 0.5\right)\right)}{t}\\ \end{array} \]
  5. Add Preprocessing

Alternative 4: 86.4% accurate, 2.0× speedup?

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

\\
x - y \cdot \frac{\mathsf{expm1}\left(z\right)}{t}
\end{array}
Derivation
  1. Initial program 60.5%

    \[x - \frac{\log \left(\left(1 - y\right) + y \cdot e^{z}\right)}{t} \]
  2. Step-by-step derivation
    1. associate-+l-77.5%

      \[\leadsto x - \frac{\log \color{blue}{\left(1 - \left(y - y \cdot e^{z}\right)\right)}}{t} \]
    2. sub-neg77.5%

      \[\leadsto x - \frac{\log \color{blue}{\left(1 + \left(-\left(y - y \cdot e^{z}\right)\right)\right)}}{t} \]
    3. log1p-define82.8%

      \[\leadsto x - \frac{\color{blue}{\mathsf{log1p}\left(-\left(y - y \cdot e^{z}\right)\right)}}{t} \]
    4. neg-sub082.8%

      \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{0 - \left(y - y \cdot e^{z}\right)}\right)}{t} \]
    5. associate-+l-82.8%

      \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{\left(0 - y\right) + y \cdot e^{z}}\right)}{t} \]
    6. neg-sub082.8%

      \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{\left(-y\right)} + y \cdot e^{z}\right)}{t} \]
    7. +-commutative82.8%

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

      \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{y \cdot e^{z} - y}\right)}{t} \]
    9. *-rgt-identity82.8%

      \[\leadsto x - \frac{\mathsf{log1p}\left(y \cdot e^{z} - \color{blue}{y \cdot 1}\right)}{t} \]
    10. distribute-lft-out--82.8%

      \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{y \cdot \left(e^{z} - 1\right)}\right)}{t} \]
    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 y around 0 77.4%

    \[\leadsto x - \color{blue}{\frac{y \cdot \left(e^{z} - 1\right)}{t}} \]
  6. Step-by-step derivation
    1. associate-/l*77.4%

      \[\leadsto x - \color{blue}{y \cdot \frac{e^{z} - 1}{t}} \]
    2. expm1-define87.1%

      \[\leadsto x - y \cdot \frac{\color{blue}{\mathsf{expm1}\left(z\right)}}{t} \]
  7. Simplified87.1%

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

Alternative 5: 81.8% accurate, 9.6× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;z \leq -5 \cdot 10^{-53}:\\ \;\;\;\;x + \frac{-1}{\frac{-0.5 \cdot \frac{z \cdot t}{y} + \frac{t}{y}}{z}}\\ \mathbf{else}:\\ \;\;\;\;x + y \cdot \left(z \cdot \frac{-1 - z \cdot 0.5}{t}\right)\\ \end{array} \end{array} \]
(FPCore (x y z t)
 :precision binary64
 (if (<= z -5e-53)
   (+ x (/ -1.0 (/ (+ (* -0.5 (/ (* z t) y)) (/ t y)) z)))
   (+ x (* y (* z (/ (- -1.0 (* z 0.5)) t))))))
double code(double x, double y, double z, double t) {
	double tmp;
	if (z <= -5e-53) {
		tmp = x + (-1.0 / (((-0.5 * ((z * t) / y)) + (t / y)) / z));
	} else {
		tmp = x + (y * (z * ((-1.0 - (z * 0.5)) / 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 <= (-5d-53)) then
        tmp = x + ((-1.0d0) / ((((-0.5d0) * ((z * t) / y)) + (t / y)) / z))
    else
        tmp = x + (y * (z * (((-1.0d0) - (z * 0.5d0)) / t)))
    end if
    code = tmp
end function
public static double code(double x, double y, double z, double t) {
	double tmp;
	if (z <= -5e-53) {
		tmp = x + (-1.0 / (((-0.5 * ((z * t) / y)) + (t / y)) / z));
	} else {
		tmp = x + (y * (z * ((-1.0 - (z * 0.5)) / t)));
	}
	return tmp;
}
def code(x, y, z, t):
	tmp = 0
	if z <= -5e-53:
		tmp = x + (-1.0 / (((-0.5 * ((z * t) / y)) + (t / y)) / z))
	else:
		tmp = x + (y * (z * ((-1.0 - (z * 0.5)) / t)))
	return tmp
function code(x, y, z, t)
	tmp = 0.0
	if (z <= -5e-53)
		tmp = Float64(x + Float64(-1.0 / Float64(Float64(Float64(-0.5 * Float64(Float64(z * t) / y)) + Float64(t / y)) / z)));
	else
		tmp = Float64(x + Float64(y * Float64(z * Float64(Float64(-1.0 - Float64(z * 0.5)) / t))));
	end
	return tmp
end
function tmp_2 = code(x, y, z, t)
	tmp = 0.0;
	if (z <= -5e-53)
		tmp = x + (-1.0 / (((-0.5 * ((z * t) / y)) + (t / y)) / z));
	else
		tmp = x + (y * (z * ((-1.0 - (z * 0.5)) / t)));
	end
	tmp_2 = tmp;
end
code[x_, y_, z_, t_] := If[LessEqual[z, -5e-53], N[(x + N[(-1.0 / N[(N[(N[(-0.5 * N[(N[(z * t), $MachinePrecision] / y), $MachinePrecision]), $MachinePrecision] + N[(t / y), $MachinePrecision]), $MachinePrecision] / z), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(x + N[(y * N[(z * N[(N[(-1.0 - N[(z * 0.5), $MachinePrecision]), $MachinePrecision] / t), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;z \leq -5 \cdot 10^{-53}:\\
\;\;\;\;x + \frac{-1}{\frac{-0.5 \cdot \frac{z \cdot t}{y} + \frac{t}{y}}{z}}\\

\mathbf{else}:\\
\;\;\;\;x + y \cdot \left(z \cdot \frac{-1 - z \cdot 0.5}{t}\right)\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if z < -5e-53

    1. Initial program 77.3%

      \[x - \frac{\log \left(\left(1 - y\right) + y \cdot e^{z}\right)}{t} \]
    2. Step-by-step derivation
      1. associate-+l-77.4%

        \[\leadsto x - \frac{\log \color{blue}{\left(1 - \left(y - y \cdot e^{z}\right)\right)}}{t} \]
      2. sub-neg77.4%

        \[\leadsto x - \frac{\log \color{blue}{\left(1 + \left(-\left(y - y \cdot e^{z}\right)\right)\right)}}{t} \]
      3. log1p-define93.0%

        \[\leadsto x - \frac{\color{blue}{\mathsf{log1p}\left(-\left(y - y \cdot e^{z}\right)\right)}}{t} \]
      4. neg-sub093.0%

        \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{0 - \left(y - y \cdot e^{z}\right)}\right)}{t} \]
      5. associate-+l-93.0%

        \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{\left(0 - y\right) + y \cdot e^{z}}\right)}{t} \]
      6. neg-sub093.0%

        \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{\left(-y\right)} + y \cdot e^{z}\right)}{t} \]
      7. +-commutative93.0%

        \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{y \cdot e^{z} + \left(-y\right)}\right)}{t} \]
      8. unsub-neg93.0%

        \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{y \cdot e^{z} - y}\right)}{t} \]
      9. *-rgt-identity93.0%

        \[\leadsto x - \frac{\mathsf{log1p}\left(y \cdot e^{z} - \color{blue}{y \cdot 1}\right)}{t} \]
      10. distribute-lft-out--93.0%

        \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{y \cdot \left(e^{z} - 1\right)}\right)}{t} \]
      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 77.2%

      \[\leadsto x - \frac{\color{blue}{y \cdot \left(e^{z} - 1\right)}}{t} \]
    6. Step-by-step derivation
      1. expm1-define82.9%

        \[\leadsto x - \frac{y \cdot \color{blue}{\mathsf{expm1}\left(z\right)}}{t} \]
    7. Simplified82.9%

      \[\leadsto x - \frac{\color{blue}{y \cdot \mathsf{expm1}\left(z\right)}}{t} \]
    8. Step-by-step derivation
      1. clear-num82.9%

        \[\leadsto x - \color{blue}{\frac{1}{\frac{t}{y \cdot \mathsf{expm1}\left(z\right)}}} \]
      2. inv-pow82.9%

        \[\leadsto x - \color{blue}{{\left(\frac{t}{y \cdot \mathsf{expm1}\left(z\right)}\right)}^{-1}} \]
    9. Applied egg-rr82.9%

      \[\leadsto x - \color{blue}{{\left(\frac{t}{y \cdot \mathsf{expm1}\left(z\right)}\right)}^{-1}} \]
    10. Step-by-step derivation
      1. unpow-182.9%

        \[\leadsto x - \color{blue}{\frac{1}{\frac{t}{y \cdot \mathsf{expm1}\left(z\right)}}} \]
      2. expm1-define77.2%

        \[\leadsto x - \frac{1}{\frac{t}{y \cdot \color{blue}{\left(e^{z} - 1\right)}}} \]
      3. associate-/r*77.1%

        \[\leadsto x - \frac{1}{\color{blue}{\frac{\frac{t}{y}}{e^{z} - 1}}} \]
      4. expm1-define82.9%

        \[\leadsto x - \frac{1}{\frac{\frac{t}{y}}{\color{blue}{\mathsf{expm1}\left(z\right)}}} \]
    11. Simplified82.9%

      \[\leadsto x - \color{blue}{\frac{1}{\frac{\frac{t}{y}}{\mathsf{expm1}\left(z\right)}}} \]
    12. Taylor expanded in z around 0 72.2%

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

    if -5e-53 < z

    1. Initial program 52.3%

      \[x - \frac{\log \left(\left(1 - y\right) + y \cdot e^{z}\right)}{t} \]
    2. Step-by-step derivation
      1. associate-+l-77.5%

        \[\leadsto x - \frac{\log \color{blue}{\left(1 - \left(y - y \cdot e^{z}\right)\right)}}{t} \]
      2. sub-neg77.5%

        \[\leadsto x - \frac{\log \color{blue}{\left(1 + \left(-\left(y - y \cdot e^{z}\right)\right)\right)}}{t} \]
      3. log1p-define77.8%

        \[\leadsto x - \frac{\color{blue}{\mathsf{log1p}\left(-\left(y - y \cdot e^{z}\right)\right)}}{t} \]
      4. neg-sub077.8%

        \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{0 - \left(y - y \cdot e^{z}\right)}\right)}{t} \]
      5. associate-+l-77.8%

        \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{\left(0 - y\right) + y \cdot e^{z}}\right)}{t} \]
      6. neg-sub077.8%

        \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{\left(-y\right)} + y \cdot e^{z}\right)}{t} \]
      7. +-commutative77.8%

        \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{y \cdot e^{z} + \left(-y\right)}\right)}{t} \]
      8. unsub-neg77.8%

        \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{y \cdot e^{z} - y}\right)}{t} \]
      9. *-rgt-identity77.8%

        \[\leadsto x - \frac{\mathsf{log1p}\left(y \cdot e^{z} - \color{blue}{y \cdot 1}\right)}{t} \]
      10. distribute-lft-out--77.8%

        \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{y \cdot \left(e^{z} - 1\right)}\right)}{t} \]
      11. expm1-define97.4%

        \[\leadsto x - \frac{\mathsf{log1p}\left(y \cdot \color{blue}{\mathsf{expm1}\left(z\right)}\right)}{t} \]
    3. Simplified97.4%

      \[\leadsto \color{blue}{x - \frac{\mathsf{log1p}\left(y \cdot \mathsf{expm1}\left(z\right)\right)}{t}} \]
    4. Add Preprocessing
    5. Taylor expanded in z around 0 77.7%

      \[\leadsto x - \frac{\color{blue}{z \cdot \left(y + 0.5 \cdot \left(z \cdot \left(y + -1 \cdot {y}^{2}\right)\right)\right)}}{t} \]
    6. Step-by-step derivation
      1. associate-*r*77.7%

        \[\leadsto x - \frac{z \cdot \left(y + \color{blue}{\left(0.5 \cdot z\right) \cdot \left(y + -1 \cdot {y}^{2}\right)}\right)}{t} \]
      2. mul-1-neg77.7%

        \[\leadsto x - \frac{z \cdot \left(y + \left(0.5 \cdot z\right) \cdot \left(y + \color{blue}{\left(-{y}^{2}\right)}\right)\right)}{t} \]
    7. Simplified77.7%

      \[\leadsto x - \frac{\color{blue}{z \cdot \left(y + \left(0.5 \cdot z\right) \cdot \left(y + \left(-{y}^{2}\right)\right)\right)}}{t} \]
    8. Taylor expanded in y around 0 88.3%

      \[\leadsto x - \color{blue}{\frac{y \cdot \left(z \cdot \left(1 + 0.5 \cdot z\right)\right)}{t}} \]
    9. Step-by-step derivation
      1. associate-/l*89.2%

        \[\leadsto x - \color{blue}{y \cdot \frac{z \cdot \left(1 + 0.5 \cdot z\right)}{t}} \]
      2. associate-/l*89.2%

        \[\leadsto x - y \cdot \color{blue}{\left(z \cdot \frac{1 + 0.5 \cdot z}{t}\right)} \]
      3. *-commutative89.2%

        \[\leadsto x - y \cdot \left(z \cdot \frac{1 + \color{blue}{z \cdot 0.5}}{t}\right) \]
    10. Simplified89.2%

      \[\leadsto x - \color{blue}{y \cdot \left(z \cdot \frac{1 + z \cdot 0.5}{t}\right)} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification83.6%

    \[\leadsto \begin{array}{l} \mathbf{if}\;z \leq -5 \cdot 10^{-53}:\\ \;\;\;\;x + \frac{-1}{\frac{-0.5 \cdot \frac{z \cdot t}{y} + \frac{t}{y}}{z}}\\ \mathbf{else}:\\ \;\;\;\;x + y \cdot \left(z \cdot \frac{-1 - z \cdot 0.5}{t}\right)\\ \end{array} \]
  5. Add Preprocessing

Alternative 6: 74.4% accurate, 23.4× speedup?

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

\\
x + y \cdot \left(z \cdot \frac{-1}{t}\right)
\end{array}
Derivation
  1. Initial program 60.5%

    \[x - \frac{\log \left(\left(1 - y\right) + y \cdot e^{z}\right)}{t} \]
  2. Step-by-step derivation
    1. associate-+l-77.5%

      \[\leadsto x - \frac{\log \color{blue}{\left(1 - \left(y - y \cdot e^{z}\right)\right)}}{t} \]
    2. sub-neg77.5%

      \[\leadsto x - \frac{\log \color{blue}{\left(1 + \left(-\left(y - y \cdot e^{z}\right)\right)\right)}}{t} \]
    3. log1p-define82.8%

      \[\leadsto x - \frac{\color{blue}{\mathsf{log1p}\left(-\left(y - y \cdot e^{z}\right)\right)}}{t} \]
    4. neg-sub082.8%

      \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{0 - \left(y - y \cdot e^{z}\right)}\right)}{t} \]
    5. associate-+l-82.8%

      \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{\left(0 - y\right) + y \cdot e^{z}}\right)}{t} \]
    6. neg-sub082.8%

      \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{\left(-y\right)} + y \cdot e^{z}\right)}{t} \]
    7. +-commutative82.8%

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

      \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{y \cdot e^{z} - y}\right)}{t} \]
    9. *-rgt-identity82.8%

      \[\leadsto x - \frac{\mathsf{log1p}\left(y \cdot e^{z} - \color{blue}{y \cdot 1}\right)}{t} \]
    10. distribute-lft-out--82.8%

      \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{y \cdot \left(e^{z} - 1\right)}\right)}{t} \]
    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 64.0%

    \[\leadsto x - \frac{\color{blue}{z \cdot \left(y + 0.5 \cdot \left(z \cdot \left(y + -1 \cdot {y}^{2}\right)\right)\right)}}{t} \]
  6. Step-by-step derivation
    1. associate-*r*64.0%

      \[\leadsto x - \frac{z \cdot \left(y + \color{blue}{\left(0.5 \cdot z\right) \cdot \left(y + -1 \cdot {y}^{2}\right)}\right)}{t} \]
    2. mul-1-neg64.0%

      \[\leadsto x - \frac{z \cdot \left(y + \left(0.5 \cdot z\right) \cdot \left(y + \color{blue}{\left(-{y}^{2}\right)}\right)\right)}{t} \]
  7. Simplified64.0%

    \[\leadsto x - \frac{\color{blue}{z \cdot \left(y + \left(0.5 \cdot z\right) \cdot \left(y + \left(-{y}^{2}\right)\right)\right)}}{t} \]
  8. Taylor expanded in y around 0 69.9%

    \[\leadsto x - \color{blue}{\frac{y \cdot \left(z \cdot \left(1 + 0.5 \cdot z\right)\right)}{t}} \]
  9. Step-by-step derivation
    1. associate-/l*70.1%

      \[\leadsto x - \color{blue}{y \cdot \frac{z \cdot \left(1 + 0.5 \cdot z\right)}{t}} \]
    2. associate-/l*72.0%

      \[\leadsto x - y \cdot \color{blue}{\left(z \cdot \frac{1 + 0.5 \cdot z}{t}\right)} \]
    3. *-commutative72.0%

      \[\leadsto x - y \cdot \left(z \cdot \frac{1 + \color{blue}{z \cdot 0.5}}{t}\right) \]
  10. Simplified72.0%

    \[\leadsto x - \color{blue}{y \cdot \left(z \cdot \frac{1 + z \cdot 0.5}{t}\right)} \]
  11. Taylor expanded in z around 0 76.0%

    \[\leadsto x - y \cdot \left(z \cdot \color{blue}{\frac{1}{t}}\right) \]
  12. Final simplification76.0%

    \[\leadsto x + y \cdot \left(z \cdot \frac{-1}{t}\right) \]
  13. Add Preprocessing

Alternative 7: 74.4% accurate, 30.1× speedup?

\[\begin{array}{l} \\ x - y \cdot \frac{z}{t} \end{array} \]
(FPCore (x y z t) :precision binary64 (- x (* y (/ z t))))
double code(double x, double y, double z, double t) {
	return x - (y * (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 - (y * (z / t))
end function
public static double code(double x, double y, double z, double t) {
	return x - (y * (z / t));
}
def code(x, y, z, t):
	return x - (y * (z / t))
function code(x, y, z, t)
	return Float64(x - Float64(y * Float64(z / t)))
end
function tmp = code(x, y, z, t)
	tmp = x - (y * (z / t));
end
code[x_, y_, z_, t_] := N[(x - N[(y * N[(z / t), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
x - y \cdot \frac{z}{t}
\end{array}
Derivation
  1. Initial program 60.5%

    \[x - \frac{\log \left(\left(1 - y\right) + y \cdot e^{z}\right)}{t} \]
  2. Step-by-step derivation
    1. associate-+l-77.5%

      \[\leadsto x - \frac{\log \color{blue}{\left(1 - \left(y - y \cdot e^{z}\right)\right)}}{t} \]
    2. sub-neg77.5%

      \[\leadsto x - \frac{\log \color{blue}{\left(1 + \left(-\left(y - y \cdot e^{z}\right)\right)\right)}}{t} \]
    3. log1p-define82.8%

      \[\leadsto x - \frac{\color{blue}{\mathsf{log1p}\left(-\left(y - y \cdot e^{z}\right)\right)}}{t} \]
    4. neg-sub082.8%

      \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{0 - \left(y - y \cdot e^{z}\right)}\right)}{t} \]
    5. associate-+l-82.8%

      \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{\left(0 - y\right) + y \cdot e^{z}}\right)}{t} \]
    6. neg-sub082.8%

      \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{\left(-y\right)} + y \cdot e^{z}\right)}{t} \]
    7. +-commutative82.8%

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

      \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{y \cdot e^{z} - y}\right)}{t} \]
    9. *-rgt-identity82.8%

      \[\leadsto x - \frac{\mathsf{log1p}\left(y \cdot e^{z} - \color{blue}{y \cdot 1}\right)}{t} \]
    10. distribute-lft-out--82.8%

      \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{y \cdot \left(e^{z} - 1\right)}\right)}{t} \]
    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 75.7%

    \[\leadsto x - \color{blue}{\frac{y \cdot z}{t}} \]
  6. Step-by-step derivation
    1. associate-/l*76.0%

      \[\leadsto x - \color{blue}{y \cdot \frac{z}{t}} \]
  7. Simplified76.0%

    \[\leadsto x - \color{blue}{y \cdot \frac{z}{t}} \]
  8. Add Preprocessing

Developer target: 74.4% 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 2024085 
(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)))