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

Percentage Accurate: 61.5% → 98.5%
Time: 14.7s
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: 61.5% 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: 98.5% 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 62.2%

    \[x - \frac{\log \left(\left(1 - y\right) + y \cdot e^{z}\right)}{t} \]
  2. Step-by-step derivation
    1. associate-+l-73.7%

      \[\leadsto x - \frac{\log \color{blue}{\left(1 - \left(y - y \cdot e^{z}\right)\right)}}{t} \]
    2. sub-neg73.7%

      \[\leadsto x - \frac{\log \color{blue}{\left(1 + \left(-\left(y - y \cdot e^{z}\right)\right)\right)}}{t} \]
    3. log1p-def79.0%

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

      \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{0 - \left(y - y \cdot e^{z}\right)}\right)}{t} \]
    5. associate-+l-79.0%

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

      \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{\left(-y\right)} + y \cdot e^{z}\right)}{t} \]
    7. neg-mul-179.0%

      \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{-1 \cdot y} + y \cdot e^{z}\right)}{t} \]
    8. *-commutative79.0%

      \[\leadsto x - \frac{\mathsf{log1p}\left(-1 \cdot y + \color{blue}{e^{z} \cdot y}\right)}{t} \]
    9. distribute-rgt-out79.0%

      \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{y \cdot \left(-1 + e^{z}\right)}\right)}{t} \]
    10. +-commutative79.0%

      \[\leadsto x - \frac{\mathsf{log1p}\left(y \cdot \color{blue}{\left(e^{z} + -1\right)}\right)}{t} \]
    11. metadata-eval79.0%

      \[\leadsto x - \frac{\mathsf{log1p}\left(y \cdot \left(e^{z} + \color{blue}{\left(-1\right)}\right)\right)}{t} \]
    12. sub-neg79.0%

      \[\leadsto x - \frac{\mathsf{log1p}\left(y \cdot \color{blue}{\left(e^{z} - 1\right)}\right)}{t} \]
    13. expm1-def97.6%

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

    \[\leadsto \color{blue}{x - \frac{\mathsf{log1p}\left(y \cdot \mathsf{expm1}\left(z\right)\right)}{t}} \]
  4. Final simplification97.6%

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

Alternative 2: 85.7% accurate, 1.9× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;z \leq -4 \cdot 10^{-81}:\\ \;\;\;\;x - \frac{\mathsf{expm1}\left(z\right)}{\frac{t}{y}}\\ \mathbf{else}:\\ \;\;\;\;x + y \cdot \left(z \cdot \left(\frac{z}{t} \cdot -0.5\right) - \frac{z}{t}\right)\\ \end{array} \end{array} \]
(FPCore (x y z t)
 :precision binary64
 (if (<= z -4e-81)
   (- x (/ (expm1 z) (/ t y)))
   (+ x (* y (- (* z (* (/ z t) -0.5)) (/ z t))))))
double code(double x, double y, double z, double t) {
	double tmp;
	if (z <= -4e-81) {
		tmp = x - (expm1(z) / (t / y));
	} else {
		tmp = x + (y * ((z * ((z / t) * -0.5)) - (z / t)));
	}
	return tmp;
}
public static double code(double x, double y, double z, double t) {
	double tmp;
	if (z <= -4e-81) {
		tmp = x - (Math.expm1(z) / (t / y));
	} else {
		tmp = x + (y * ((z * ((z / t) * -0.5)) - (z / t)));
	}
	return tmp;
}
def code(x, y, z, t):
	tmp = 0
	if z <= -4e-81:
		tmp = x - (math.expm1(z) / (t / y))
	else:
		tmp = x + (y * ((z * ((z / t) * -0.5)) - (z / t)))
	return tmp
function code(x, y, z, t)
	tmp = 0.0
	if (z <= -4e-81)
		tmp = Float64(x - Float64(expm1(z) / Float64(t / y)));
	else
		tmp = Float64(x + Float64(y * Float64(Float64(z * Float64(Float64(z / t) * -0.5)) - Float64(z / t))));
	end
	return tmp
end
code[x_, y_, z_, t_] := If[LessEqual[z, -4e-81], N[(x - N[(N[(Exp[z] - 1), $MachinePrecision] / N[(t / y), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(x + N[(y * N[(N[(z * N[(N[(z / t), $MachinePrecision] * -0.5), $MachinePrecision]), $MachinePrecision] - N[(z / t), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;z \leq -4 \cdot 10^{-81}:\\
\;\;\;\;x - \frac{\mathsf{expm1}\left(z\right)}{\frac{t}{y}}\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if z < -3.9999999999999998e-81

    1. Initial program 79.4%

      \[x - \frac{\log \left(\left(1 - y\right) + y \cdot e^{z}\right)}{t} \]
    2. Step-by-step derivation
      1. associate-+l-80.5%

        \[\leadsto x - \frac{\log \color{blue}{\left(1 - \left(y - y \cdot e^{z}\right)\right)}}{t} \]
      2. sub-neg80.5%

        \[\leadsto x - \frac{\log \color{blue}{\left(1 + \left(-\left(y - y \cdot e^{z}\right)\right)\right)}}{t} \]
      3. log1p-def91.7%

        \[\leadsto x - \frac{\color{blue}{\mathsf{log1p}\left(-\left(y - y \cdot e^{z}\right)\right)}}{t} \]
      4. neg-sub091.7%

        \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{0 - \left(y - y \cdot e^{z}\right)}\right)}{t} \]
      5. associate-+l-91.7%

        \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{\left(0 - y\right) + y \cdot e^{z}}\right)}{t} \]
      6. neg-sub091.7%

        \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{\left(-y\right)} + y \cdot e^{z}\right)}{t} \]
      7. neg-mul-191.7%

        \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{-1 \cdot y} + y \cdot e^{z}\right)}{t} \]
      8. *-commutative91.7%

        \[\leadsto x - \frac{\mathsf{log1p}\left(-1 \cdot y + \color{blue}{e^{z} \cdot y}\right)}{t} \]
      9. distribute-rgt-out91.8%

        \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{y \cdot \left(-1 + e^{z}\right)}\right)}{t} \]
      10. +-commutative91.8%

        \[\leadsto x - \frac{\mathsf{log1p}\left(y \cdot \color{blue}{\left(e^{z} + -1\right)}\right)}{t} \]
      11. metadata-eval91.8%

        \[\leadsto x - \frac{\mathsf{log1p}\left(y \cdot \left(e^{z} + \color{blue}{\left(-1\right)}\right)\right)}{t} \]
      12. sub-neg91.8%

        \[\leadsto x - \frac{\mathsf{log1p}\left(y \cdot \color{blue}{\left(e^{z} - 1\right)}\right)}{t} \]
      13. expm1-def99.1%

        \[\leadsto x - \frac{\mathsf{log1p}\left(y \cdot \color{blue}{\mathsf{expm1}\left(z\right)}\right)}{t} \]
    3. Simplified99.1%

      \[\leadsto \color{blue}{x - \frac{\mathsf{log1p}\left(y \cdot \mathsf{expm1}\left(z\right)\right)}{t}} \]
    4. Taylor expanded in y around 0 73.3%

      \[\leadsto x - \color{blue}{\frac{\left(e^{z} - 1\right) \cdot y}{t}} \]
    5. Step-by-step derivation
      1. expm1-def76.7%

        \[\leadsto x - \frac{\color{blue}{\mathsf{expm1}\left(z\right)} \cdot y}{t} \]
      2. associate-/l*77.5%

        \[\leadsto x - \color{blue}{\frac{\mathsf{expm1}\left(z\right)}{\frac{t}{y}}} \]
    6. Simplified77.5%

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

    if -3.9999999999999998e-81 < z

    1. Initial program 50.6%

      \[x - \frac{\log \left(\left(1 - y\right) + y \cdot e^{z}\right)}{t} \]
    2. Step-by-step derivation
      1. associate-+l-69.2%

        \[\leadsto x - \frac{\log \color{blue}{\left(1 - \left(y - y \cdot e^{z}\right)\right)}}{t} \]
      2. sub-neg69.2%

        \[\leadsto x - \frac{\log \color{blue}{\left(1 + \left(-\left(y - y \cdot e^{z}\right)\right)\right)}}{t} \]
      3. log1p-def70.5%

        \[\leadsto x - \frac{\color{blue}{\mathsf{log1p}\left(-\left(y - y \cdot e^{z}\right)\right)}}{t} \]
      4. neg-sub070.5%

        \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{0 - \left(y - y \cdot e^{z}\right)}\right)}{t} \]
      5. associate-+l-70.5%

        \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{\left(0 - y\right) + y \cdot e^{z}}\right)}{t} \]
      6. neg-sub070.5%

        \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{\left(-y\right)} + y \cdot e^{z}\right)}{t} \]
      7. neg-mul-170.5%

        \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{-1 \cdot y} + y \cdot e^{z}\right)}{t} \]
      8. *-commutative70.5%

        \[\leadsto x - \frac{\mathsf{log1p}\left(-1 \cdot y + \color{blue}{e^{z} \cdot y}\right)}{t} \]
      9. distribute-rgt-out70.5%

        \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{y \cdot \left(-1 + e^{z}\right)}\right)}{t} \]
      10. +-commutative70.5%

        \[\leadsto x - \frac{\mathsf{log1p}\left(y \cdot \color{blue}{\left(e^{z} + -1\right)}\right)}{t} \]
      11. metadata-eval70.5%

        \[\leadsto x - \frac{\mathsf{log1p}\left(y \cdot \left(e^{z} + \color{blue}{\left(-1\right)}\right)\right)}{t} \]
      12. sub-neg70.5%

        \[\leadsto x - \frac{\mathsf{log1p}\left(y \cdot \color{blue}{\left(e^{z} - 1\right)}\right)}{t} \]
      13. expm1-def96.6%

        \[\leadsto x - \frac{\mathsf{log1p}\left(y \cdot \color{blue}{\mathsf{expm1}\left(z\right)}\right)}{t} \]
    3. Simplified96.6%

      \[\leadsto \color{blue}{x - \frac{\mathsf{log1p}\left(y \cdot \mathsf{expm1}\left(z\right)\right)}{t}} \]
    4. Taylor expanded in y around 0 70.2%

      \[\leadsto x - \color{blue}{\frac{\left(e^{z} - 1\right) \cdot y}{t}} \]
    5. Step-by-step derivation
      1. expm1-def86.5%

        \[\leadsto x - \frac{\color{blue}{\mathsf{expm1}\left(z\right)} \cdot y}{t} \]
      2. associate-/l*84.4%

        \[\leadsto x - \color{blue}{\frac{\mathsf{expm1}\left(z\right)}{\frac{t}{y}}} \]
    6. Simplified84.4%

      \[\leadsto x - \color{blue}{\frac{\mathsf{expm1}\left(z\right)}{\frac{t}{y}}} \]
    7. Taylor expanded in z around 0 86.8%

      \[\leadsto x - \color{blue}{\left(\frac{y \cdot z}{t} + 0.5 \cdot \frac{y \cdot {z}^{2}}{t}\right)} \]
    8. Step-by-step derivation
      1. *-commutative86.8%

        \[\leadsto x - \left(\frac{\color{blue}{z \cdot y}}{t} + 0.5 \cdot \frac{y \cdot {z}^{2}}{t}\right) \]
      2. associate-/l*86.8%

        \[\leadsto x - \left(\frac{z \cdot y}{t} + 0.5 \cdot \color{blue}{\frac{y}{\frac{t}{{z}^{2}}}}\right) \]
      3. unpow286.8%

        \[\leadsto x - \left(\frac{z \cdot y}{t} + 0.5 \cdot \frac{y}{\frac{t}{\color{blue}{z \cdot z}}}\right) \]
    9. Simplified86.8%

      \[\leadsto x - \color{blue}{\left(\frac{z \cdot y}{t} + 0.5 \cdot \frac{y}{\frac{t}{z \cdot z}}\right)} \]
    10. Taylor expanded in y around -inf 88.6%

      \[\leadsto x - \color{blue}{-1 \cdot \left(y \cdot \left(-0.5 \cdot \frac{{z}^{2}}{t} + -1 \cdot \frac{z}{t}\right)\right)} \]
    11. Step-by-step derivation
      1. mul-1-neg88.6%

        \[\leadsto x - \color{blue}{\left(-y \cdot \left(-0.5 \cdot \frac{{z}^{2}}{t} + -1 \cdot \frac{z}{t}\right)\right)} \]
      2. distribute-rgt-neg-in88.6%

        \[\leadsto x - \color{blue}{y \cdot \left(-\left(-0.5 \cdot \frac{{z}^{2}}{t} + -1 \cdot \frac{z}{t}\right)\right)} \]
      3. mul-1-neg88.6%

        \[\leadsto x - y \cdot \left(-\left(-0.5 \cdot \frac{{z}^{2}}{t} + \color{blue}{\left(-\frac{z}{t}\right)}\right)\right) \]
      4. unsub-neg88.6%

        \[\leadsto x - y \cdot \left(-\color{blue}{\left(-0.5 \cdot \frac{{z}^{2}}{t} - \frac{z}{t}\right)}\right) \]
      5. *-commutative88.6%

        \[\leadsto x - y \cdot \left(-\left(\color{blue}{\frac{{z}^{2}}{t} \cdot -0.5} - \frac{z}{t}\right)\right) \]
      6. unpow288.6%

        \[\leadsto x - y \cdot \left(-\left(\frac{\color{blue}{z \cdot z}}{t} \cdot -0.5 - \frac{z}{t}\right)\right) \]
      7. associate-*r/88.6%

        \[\leadsto x - y \cdot \left(-\left(\color{blue}{\left(z \cdot \frac{z}{t}\right)} \cdot -0.5 - \frac{z}{t}\right)\right) \]
      8. associate-*l*88.6%

        \[\leadsto x - y \cdot \left(-\left(\color{blue}{z \cdot \left(\frac{z}{t} \cdot -0.5\right)} - \frac{z}{t}\right)\right) \]
    12. Simplified88.6%

      \[\leadsto x - \color{blue}{y \cdot \left(-\left(z \cdot \left(\frac{z}{t} \cdot -0.5\right) - \frac{z}{t}\right)\right)} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification84.1%

    \[\leadsto \begin{array}{l} \mathbf{if}\;z \leq -4 \cdot 10^{-81}:\\ \;\;\;\;x - \frac{\mathsf{expm1}\left(z\right)}{\frac{t}{y}}\\ \mathbf{else}:\\ \;\;\;\;x + y \cdot \left(z \cdot \left(\frac{z}{t} \cdot -0.5\right) - \frac{z}{t}\right)\\ \end{array} \]

Alternative 3: 90.7% accurate, 1.9× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;z \leq -1.05 \cdot 10^{+22}:\\ \;\;\;\;x - \frac{\mathsf{expm1}\left(z\right)}{\frac{t}{y}}\\ \mathbf{else}:\\ \;\;\;\;x - \frac{\mathsf{log1p}\left(y \cdot z\right)}{t}\\ \end{array} \end{array} \]
(FPCore (x y z t)
 :precision binary64
 (if (<= z -1.05e+22) (- x (/ (expm1 z) (/ t y))) (- x (/ (log1p (* y z)) t))))
double code(double x, double y, double z, double t) {
	double tmp;
	if (z <= -1.05e+22) {
		tmp = x - (expm1(z) / (t / y));
	} 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 <= -1.05e+22) {
		tmp = x - (Math.expm1(z) / (t / y));
	} else {
		tmp = x - (Math.log1p((y * z)) / t);
	}
	return tmp;
}
def code(x, y, z, t):
	tmp = 0
	if z <= -1.05e+22:
		tmp = x - (math.expm1(z) / (t / y))
	else:
		tmp = x - (math.log1p((y * z)) / t)
	return tmp
function code(x, y, z, t)
	tmp = 0.0
	if (z <= -1.05e+22)
		tmp = Float64(x - Float64(expm1(z) / Float64(t / y)));
	else
		tmp = Float64(x - Float64(log1p(Float64(y * z)) / t));
	end
	return tmp
end
code[x_, y_, z_, t_] := If[LessEqual[z, -1.05e+22], N[(x - N[(N[(Exp[z] - 1), $MachinePrecision] / N[(t / y), $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 -1.05 \cdot 10^{+22}:\\
\;\;\;\;x - \frac{\mathsf{expm1}\left(z\right)}{\frac{t}{y}}\\

\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 < -1.0499999999999999e22

    1. Initial program 85.4%

      \[x - \frac{\log \left(\left(1 - y\right) + y \cdot e^{z}\right)}{t} \]
    2. Step-by-step derivation
      1. associate-+l-85.4%

        \[\leadsto x - \frac{\log \color{blue}{\left(1 - \left(y - y \cdot e^{z}\right)\right)}}{t} \]
      2. sub-neg85.4%

        \[\leadsto x - \frac{\log \color{blue}{\left(1 + \left(-\left(y - y \cdot e^{z}\right)\right)\right)}}{t} \]
      3. log1p-def100.0%

        \[\leadsto x - \frac{\color{blue}{\mathsf{log1p}\left(-\left(y - y \cdot e^{z}\right)\right)}}{t} \]
      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. neg-mul-1100.0%

        \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{-1 \cdot y} + y \cdot e^{z}\right)}{t} \]
      8. *-commutative100.0%

        \[\leadsto x - \frac{\mathsf{log1p}\left(-1 \cdot y + \color{blue}{e^{z} \cdot y}\right)}{t} \]
      9. distribute-rgt-out100.0%

        \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{y \cdot \left(-1 + e^{z}\right)}\right)}{t} \]
      10. +-commutative100.0%

        \[\leadsto x - \frac{\mathsf{log1p}\left(y \cdot \color{blue}{\left(e^{z} + -1\right)}\right)}{t} \]
      11. metadata-eval100.0%

        \[\leadsto x - \frac{\mathsf{log1p}\left(y \cdot \left(e^{z} + \color{blue}{\left(-1\right)}\right)\right)}{t} \]
      12. sub-neg100.0%

        \[\leadsto x - \frac{\mathsf{log1p}\left(y \cdot \color{blue}{\left(e^{z} - 1\right)}\right)}{t} \]
      13. expm1-def100.0%

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

      \[\leadsto \color{blue}{x - \frac{\mathsf{log1p}\left(y \cdot \mathsf{expm1}\left(z\right)\right)}{t}} \]
    4. Taylor expanded in y around 0 78.9%

      \[\leadsto x - \color{blue}{\frac{\left(e^{z} - 1\right) \cdot y}{t}} \]
    5. Step-by-step derivation
      1. expm1-def78.9%

        \[\leadsto x - \frac{\color{blue}{\mathsf{expm1}\left(z\right)} \cdot y}{t} \]
      2. associate-/l*78.8%

        \[\leadsto x - \color{blue}{\frac{\mathsf{expm1}\left(z\right)}{\frac{t}{y}}} \]
    6. Simplified78.8%

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

    if -1.0499999999999999e22 < z

    1. Initial program 53.1%

      \[x - \frac{\log \left(\left(1 - y\right) + y \cdot e^{z}\right)}{t} \]
    2. Step-by-step derivation
      1. remove-double-neg53.1%

        \[\leadsto x - \color{blue}{\left(-\left(-\frac{\log \left(\left(1 - y\right) + y \cdot e^{z}\right)}{t}\right)\right)} \]
      2. sub0-neg53.1%

        \[\leadsto x - \color{blue}{\left(0 - \left(-\frac{\log \left(\left(1 - y\right) + y \cdot e^{z}\right)}{t}\right)\right)} \]
      3. sub0-neg53.1%

        \[\leadsto x - \color{blue}{\left(-\left(-\frac{\log \left(\left(1 - y\right) + y \cdot e^{z}\right)}{t}\right)\right)} \]
      4. remove-double-neg53.1%

        \[\leadsto x - \color{blue}{\frac{\log \left(\left(1 - y\right) + y \cdot e^{z}\right)}{t}} \]
      5. sub-neg53.1%

        \[\leadsto x - \frac{\log \left(\color{blue}{\left(1 + \left(-y\right)\right)} + y \cdot e^{z}\right)}{t} \]
      6. associate-+l+69.2%

        \[\leadsto x - \frac{\log \color{blue}{\left(1 + \left(\left(-y\right) + y \cdot e^{z}\right)\right)}}{t} \]
      7. log1p-def70.8%

        \[\leadsto x - \frac{\color{blue}{\mathsf{log1p}\left(\left(-y\right) + y \cdot e^{z}\right)}}{t} \]
      8. +-commutative70.8%

        \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{y \cdot e^{z} + \left(-y\right)}\right)}{t} \]
      9. unsub-neg70.8%

        \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{y \cdot e^{z} - y}\right)}{t} \]
    3. Simplified70.8%

      \[\leadsto \color{blue}{x - \frac{\mathsf{log1p}\left(y \cdot e^{z} - y\right)}{t}} \]
    4. Taylor expanded in z around 0 70.5%

      \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{\left(y \cdot z + y\right)} - y\right)}{t} \]
    5. Taylor expanded in y around 0 95.9%

      \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{y \cdot z}\right)}{t} \]
    6. Step-by-step derivation
      1. *-commutative95.9%

        \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{z \cdot y}\right)}{t} \]
    7. Simplified95.9%

      \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{z \cdot y}\right)}{t} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification91.1%

    \[\leadsto \begin{array}{l} \mathbf{if}\;z \leq -1.05 \cdot 10^{+22}:\\ \;\;\;\;x - \frac{\mathsf{expm1}\left(z\right)}{\frac{t}{y}}\\ \mathbf{else}:\\ \;\;\;\;x - \frac{\mathsf{log1p}\left(y \cdot z\right)}{t}\\ \end{array} \]

Alternative 4: 90.7% accurate, 1.9× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;z \leq -1.05 \cdot 10^{+22}:\\ \;\;\;\;x - \frac{y \cdot \mathsf{expm1}\left(z\right)}{t}\\ \mathbf{else}:\\ \;\;\;\;x - \frac{\mathsf{log1p}\left(y \cdot z\right)}{t}\\ \end{array} \end{array} \]
(FPCore (x y z t)
 :precision binary64
 (if (<= z -1.05e+22) (- x (/ (* y (expm1 z)) t)) (- x (/ (log1p (* y z)) t))))
double code(double x, double y, double z, double t) {
	double tmp;
	if (z <= -1.05e+22) {
		tmp = x - ((y * expm1(z)) / 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 <= -1.05e+22) {
		tmp = x - ((y * Math.expm1(z)) / t);
	} else {
		tmp = x - (Math.log1p((y * z)) / t);
	}
	return tmp;
}
def code(x, y, z, t):
	tmp = 0
	if z <= -1.05e+22:
		tmp = x - ((y * math.expm1(z)) / t)
	else:
		tmp = x - (math.log1p((y * z)) / t)
	return tmp
function code(x, y, z, t)
	tmp = 0.0
	if (z <= -1.05e+22)
		tmp = Float64(x - Float64(Float64(y * expm1(z)) / t));
	else
		tmp = Float64(x - Float64(log1p(Float64(y * z)) / t));
	end
	return tmp
end
code[x_, y_, z_, t_] := If[LessEqual[z, -1.05e+22], N[(x - N[(N[(y * N[(Exp[z] - 1), $MachinePrecision]), $MachinePrecision] / t), $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 -1.05 \cdot 10^{+22}:\\
\;\;\;\;x - \frac{y \cdot \mathsf{expm1}\left(z\right)}{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 < -1.0499999999999999e22

    1. Initial program 85.4%

      \[x - \frac{\log \left(\left(1 - y\right) + y \cdot e^{z}\right)}{t} \]
    2. Step-by-step derivation
      1. associate-+l-85.4%

        \[\leadsto x - \frac{\log \color{blue}{\left(1 - \left(y - y \cdot e^{z}\right)\right)}}{t} \]
      2. sub-neg85.4%

        \[\leadsto x - \frac{\log \color{blue}{\left(1 + \left(-\left(y - y \cdot e^{z}\right)\right)\right)}}{t} \]
      3. log1p-def100.0%

        \[\leadsto x - \frac{\color{blue}{\mathsf{log1p}\left(-\left(y - y \cdot e^{z}\right)\right)}}{t} \]
      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. neg-mul-1100.0%

        \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{-1 \cdot y} + y \cdot e^{z}\right)}{t} \]
      8. *-commutative100.0%

        \[\leadsto x - \frac{\mathsf{log1p}\left(-1 \cdot y + \color{blue}{e^{z} \cdot y}\right)}{t} \]
      9. distribute-rgt-out100.0%

        \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{y \cdot \left(-1 + e^{z}\right)}\right)}{t} \]
      10. +-commutative100.0%

        \[\leadsto x - \frac{\mathsf{log1p}\left(y \cdot \color{blue}{\left(e^{z} + -1\right)}\right)}{t} \]
      11. metadata-eval100.0%

        \[\leadsto x - \frac{\mathsf{log1p}\left(y \cdot \left(e^{z} + \color{blue}{\left(-1\right)}\right)\right)}{t} \]
      12. sub-neg100.0%

        \[\leadsto x - \frac{\mathsf{log1p}\left(y \cdot \color{blue}{\left(e^{z} - 1\right)}\right)}{t} \]
      13. expm1-def100.0%

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

      \[\leadsto \color{blue}{x - \frac{\mathsf{log1p}\left(y \cdot \mathsf{expm1}\left(z\right)\right)}{t}} \]
    4. Taylor expanded in y around 0 78.9%

      \[\leadsto x - \frac{\color{blue}{\left(e^{z} - 1\right) \cdot y}}{t} \]
    5. Step-by-step derivation
      1. expm1-def78.9%

        \[\leadsto x - \frac{\color{blue}{\mathsf{expm1}\left(z\right)} \cdot y}{t} \]
      2. *-commutative78.9%

        \[\leadsto x - \frac{\color{blue}{y \cdot \mathsf{expm1}\left(z\right)}}{t} \]
    6. Simplified78.9%

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

    if -1.0499999999999999e22 < z

    1. Initial program 53.1%

      \[x - \frac{\log \left(\left(1 - y\right) + y \cdot e^{z}\right)}{t} \]
    2. Step-by-step derivation
      1. remove-double-neg53.1%

        \[\leadsto x - \color{blue}{\left(-\left(-\frac{\log \left(\left(1 - y\right) + y \cdot e^{z}\right)}{t}\right)\right)} \]
      2. sub0-neg53.1%

        \[\leadsto x - \color{blue}{\left(0 - \left(-\frac{\log \left(\left(1 - y\right) + y \cdot e^{z}\right)}{t}\right)\right)} \]
      3. sub0-neg53.1%

        \[\leadsto x - \color{blue}{\left(-\left(-\frac{\log \left(\left(1 - y\right) + y \cdot e^{z}\right)}{t}\right)\right)} \]
      4. remove-double-neg53.1%

        \[\leadsto x - \color{blue}{\frac{\log \left(\left(1 - y\right) + y \cdot e^{z}\right)}{t}} \]
      5. sub-neg53.1%

        \[\leadsto x - \frac{\log \left(\color{blue}{\left(1 + \left(-y\right)\right)} + y \cdot e^{z}\right)}{t} \]
      6. associate-+l+69.2%

        \[\leadsto x - \frac{\log \color{blue}{\left(1 + \left(\left(-y\right) + y \cdot e^{z}\right)\right)}}{t} \]
      7. log1p-def70.8%

        \[\leadsto x - \frac{\color{blue}{\mathsf{log1p}\left(\left(-y\right) + y \cdot e^{z}\right)}}{t} \]
      8. +-commutative70.8%

        \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{y \cdot e^{z} + \left(-y\right)}\right)}{t} \]
      9. unsub-neg70.8%

        \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{y \cdot e^{z} - y}\right)}{t} \]
    3. Simplified70.8%

      \[\leadsto \color{blue}{x - \frac{\mathsf{log1p}\left(y \cdot e^{z} - y\right)}{t}} \]
    4. Taylor expanded in z around 0 70.5%

      \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{\left(y \cdot z + y\right)} - y\right)}{t} \]
    5. Taylor expanded in y around 0 95.9%

      \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{y \cdot z}\right)}{t} \]
    6. Step-by-step derivation
      1. *-commutative95.9%

        \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{z \cdot y}\right)}{t} \]
    7. Simplified95.9%

      \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{z \cdot y}\right)}{t} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification91.1%

    \[\leadsto \begin{array}{l} \mathbf{if}\;z \leq -1.05 \cdot 10^{+22}:\\ \;\;\;\;x - \frac{y \cdot \mathsf{expm1}\left(z\right)}{t}\\ \mathbf{else}:\\ \;\;\;\;x - \frac{\mathsf{log1p}\left(y \cdot z\right)}{t}\\ \end{array} \]

Alternative 5: 71.2% accurate, 30.1× speedup?

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

\\
x - z \cdot \frac{y}{t}
\end{array}
Derivation
  1. Initial program 62.2%

    \[x - \frac{\log \left(\left(1 - y\right) + y \cdot e^{z}\right)}{t} \]
  2. Step-by-step derivation
    1. associate-+l-73.7%

      \[\leadsto x - \frac{\log \color{blue}{\left(1 - \left(y - y \cdot e^{z}\right)\right)}}{t} \]
    2. sub-neg73.7%

      \[\leadsto x - \frac{\log \color{blue}{\left(1 + \left(-\left(y - y \cdot e^{z}\right)\right)\right)}}{t} \]
    3. log1p-def79.0%

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

      \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{0 - \left(y - y \cdot e^{z}\right)}\right)}{t} \]
    5. associate-+l-79.0%

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

      \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{\left(-y\right)} + y \cdot e^{z}\right)}{t} \]
    7. neg-mul-179.0%

      \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{-1 \cdot y} + y \cdot e^{z}\right)}{t} \]
    8. *-commutative79.0%

      \[\leadsto x - \frac{\mathsf{log1p}\left(-1 \cdot y + \color{blue}{e^{z} \cdot y}\right)}{t} \]
    9. distribute-rgt-out79.0%

      \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{y \cdot \left(-1 + e^{z}\right)}\right)}{t} \]
    10. +-commutative79.0%

      \[\leadsto x - \frac{\mathsf{log1p}\left(y \cdot \color{blue}{\left(e^{z} + -1\right)}\right)}{t} \]
    11. metadata-eval79.0%

      \[\leadsto x - \frac{\mathsf{log1p}\left(y \cdot \left(e^{z} + \color{blue}{\left(-1\right)}\right)\right)}{t} \]
    12. sub-neg79.0%

      \[\leadsto x - \frac{\mathsf{log1p}\left(y \cdot \color{blue}{\left(e^{z} - 1\right)}\right)}{t} \]
    13. expm1-def97.6%

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

    \[\leadsto \color{blue}{x - \frac{\mathsf{log1p}\left(y \cdot \mathsf{expm1}\left(z\right)\right)}{t}} \]
  4. Taylor expanded in z around 0 72.5%

    \[\leadsto x - \color{blue}{\frac{y \cdot z}{t}} \]
  5. Step-by-step derivation
    1. associate-/l*73.9%

      \[\leadsto x - \color{blue}{\frac{y}{\frac{t}{z}}} \]
    2. associate-/r/72.4%

      \[\leadsto x - \color{blue}{\frac{y}{t} \cdot z} \]
  6. Simplified72.4%

    \[\leadsto x - \color{blue}{\frac{y}{t} \cdot z} \]
  7. Final simplification72.4%

    \[\leadsto x - z \cdot \frac{y}{t} \]

Alternative 6: 73.5% 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 62.2%

    \[x - \frac{\log \left(\left(1 - y\right) + y \cdot e^{z}\right)}{t} \]
  2. Step-by-step derivation
    1. associate-+l-73.7%

      \[\leadsto x - \frac{\log \color{blue}{\left(1 - \left(y - y \cdot e^{z}\right)\right)}}{t} \]
    2. sub-neg73.7%

      \[\leadsto x - \frac{\log \color{blue}{\left(1 + \left(-\left(y - y \cdot e^{z}\right)\right)\right)}}{t} \]
    3. log1p-def79.0%

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

      \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{0 - \left(y - y \cdot e^{z}\right)}\right)}{t} \]
    5. associate-+l-79.0%

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

      \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{\left(-y\right)} + y \cdot e^{z}\right)}{t} \]
    7. neg-mul-179.0%

      \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{-1 \cdot y} + y \cdot e^{z}\right)}{t} \]
    8. *-commutative79.0%

      \[\leadsto x - \frac{\mathsf{log1p}\left(-1 \cdot y + \color{blue}{e^{z} \cdot y}\right)}{t} \]
    9. distribute-rgt-out79.0%

      \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{y \cdot \left(-1 + e^{z}\right)}\right)}{t} \]
    10. +-commutative79.0%

      \[\leadsto x - \frac{\mathsf{log1p}\left(y \cdot \color{blue}{\left(e^{z} + -1\right)}\right)}{t} \]
    11. metadata-eval79.0%

      \[\leadsto x - \frac{\mathsf{log1p}\left(y \cdot \left(e^{z} + \color{blue}{\left(-1\right)}\right)\right)}{t} \]
    12. sub-neg79.0%

      \[\leadsto x - \frac{\mathsf{log1p}\left(y \cdot \color{blue}{\left(e^{z} - 1\right)}\right)}{t} \]
    13. expm1-def97.6%

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

    \[\leadsto \color{blue}{x - \frac{\mathsf{log1p}\left(y \cdot \mathsf{expm1}\left(z\right)\right)}{t}} \]
  4. Taylor expanded in z around 0 72.5%

    \[\leadsto x - \color{blue}{\frac{y \cdot z}{t}} \]
  5. Step-by-step derivation
    1. associate-/l*73.9%

      \[\leadsto x - \color{blue}{\frac{y}{\frac{t}{z}}} \]
    2. associate-/r/72.4%

      \[\leadsto x - \color{blue}{\frac{y}{t} \cdot z} \]
  6. Simplified72.4%

    \[\leadsto x - \color{blue}{\frac{y}{t} \cdot z} \]
  7. Step-by-step derivation
    1. expm1-log1p-u67.6%

      \[\leadsto x - \color{blue}{\mathsf{expm1}\left(\mathsf{log1p}\left(\frac{y}{t} \cdot z\right)\right)} \]
    2. expm1-udef62.4%

      \[\leadsto x - \color{blue}{\left(e^{\mathsf{log1p}\left(\frac{y}{t} \cdot z\right)} - 1\right)} \]
    3. *-commutative62.4%

      \[\leadsto x - \left(e^{\mathsf{log1p}\left(\color{blue}{z \cdot \frac{y}{t}}\right)} - 1\right) \]
    4. clear-num62.4%

      \[\leadsto x - \left(e^{\mathsf{log1p}\left(z \cdot \color{blue}{\frac{1}{\frac{t}{y}}}\right)} - 1\right) \]
    5. un-div-inv62.4%

      \[\leadsto x - \left(e^{\mathsf{log1p}\left(\color{blue}{\frac{z}{\frac{t}{y}}}\right)} - 1\right) \]
  8. Applied egg-rr62.4%

    \[\leadsto x - \color{blue}{\left(e^{\mathsf{log1p}\left(\frac{z}{\frac{t}{y}}\right)} - 1\right)} \]
  9. Step-by-step derivation
    1. expm1-def67.6%

      \[\leadsto x - \color{blue}{\mathsf{expm1}\left(\mathsf{log1p}\left(\frac{z}{\frac{t}{y}}\right)\right)} \]
    2. expm1-log1p72.4%

      \[\leadsto x - \color{blue}{\frac{z}{\frac{t}{y}}} \]
    3. associate-/r/73.9%

      \[\leadsto x - \color{blue}{\frac{z}{t} \cdot y} \]
  10. Simplified73.9%

    \[\leadsto x - \color{blue}{\frac{z}{t} \cdot y} \]
  11. Final simplification73.9%

    \[\leadsto x - y \cdot \frac{z}{t} \]

Alternative 7: 73.6% accurate, 30.1× speedup?

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

\\
x - \frac{y}{\frac{t}{z}}
\end{array}
Derivation
  1. Initial program 62.2%

    \[x - \frac{\log \left(\left(1 - y\right) + y \cdot e^{z}\right)}{t} \]
  2. Step-by-step derivation
    1. associate-+l-73.7%

      \[\leadsto x - \frac{\log \color{blue}{\left(1 - \left(y - y \cdot e^{z}\right)\right)}}{t} \]
    2. sub-neg73.7%

      \[\leadsto x - \frac{\log \color{blue}{\left(1 + \left(-\left(y - y \cdot e^{z}\right)\right)\right)}}{t} \]
    3. log1p-def79.0%

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

      \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{0 - \left(y - y \cdot e^{z}\right)}\right)}{t} \]
    5. associate-+l-79.0%

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

      \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{\left(-y\right)} + y \cdot e^{z}\right)}{t} \]
    7. neg-mul-179.0%

      \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{-1 \cdot y} + y \cdot e^{z}\right)}{t} \]
    8. *-commutative79.0%

      \[\leadsto x - \frac{\mathsf{log1p}\left(-1 \cdot y + \color{blue}{e^{z} \cdot y}\right)}{t} \]
    9. distribute-rgt-out79.0%

      \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{y \cdot \left(-1 + e^{z}\right)}\right)}{t} \]
    10. +-commutative79.0%

      \[\leadsto x - \frac{\mathsf{log1p}\left(y \cdot \color{blue}{\left(e^{z} + -1\right)}\right)}{t} \]
    11. metadata-eval79.0%

      \[\leadsto x - \frac{\mathsf{log1p}\left(y \cdot \left(e^{z} + \color{blue}{\left(-1\right)}\right)\right)}{t} \]
    12. sub-neg79.0%

      \[\leadsto x - \frac{\mathsf{log1p}\left(y \cdot \color{blue}{\left(e^{z} - 1\right)}\right)}{t} \]
    13. expm1-def97.6%

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

    \[\leadsto \color{blue}{x - \frac{\mathsf{log1p}\left(y \cdot \mathsf{expm1}\left(z\right)\right)}{t}} \]
  4. Taylor expanded in z around 0 72.5%

    \[\leadsto x - \color{blue}{\frac{y \cdot z}{t}} \]
  5. Step-by-step derivation
    1. associate-/l*73.9%

      \[\leadsto x - \color{blue}{\frac{y}{\frac{t}{z}}} \]
  6. Simplified73.9%

    \[\leadsto x - \color{blue}{\frac{y}{\frac{t}{z}}} \]
  7. Final simplification73.9%

    \[\leadsto x - \frac{y}{\frac{t}{z}} \]

Developer target: 73.6% 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 2023196 
(FPCore (x y z t)
  :name "System.Random.MWC.Distributions:truncatedExp from mwc-random-0.13.3.2"
  :precision binary64

  :herbie-target
  (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)))