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

Percentage Accurate: 61.7% → 98.5%
Time: 13.6s
Alternatives: 6
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 6 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: 61.7% 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 59.5%

    \[x - \frac{\log \left(\left(1 - y\right) + y \cdot e^{z}\right)}{t} \]
  2. Step-by-step derivation
    1. sub-neg59.5%

      \[\leadsto x - \frac{\log \left(\color{blue}{\left(1 + \left(-y\right)\right)} + y \cdot e^{z}\right)}{t} \]
    2. associate-+l+76.7%

      \[\leadsto x - \frac{\log \color{blue}{\left(1 + \left(\left(-y\right) + y \cdot e^{z}\right)\right)}}{t} \]
    3. cancel-sign-sub76.7%

      \[\leadsto x - \frac{\log \left(1 + \color{blue}{\left(\left(-y\right) - \left(-y\right) \cdot e^{z}\right)}\right)}{t} \]
    4. log1p-def82.1%

      \[\leadsto x - \frac{\color{blue}{\mathsf{log1p}\left(\left(-y\right) - \left(-y\right) \cdot e^{z}\right)}}{t} \]
    5. cancel-sign-sub82.1%

      \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{\left(-y\right) + y \cdot e^{z}}\right)}{t} \]
    6. +-commutative82.1%

      \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{y \cdot e^{z} + \left(-y\right)}\right)}{t} \]
    7. unsub-neg82.1%

      \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{y \cdot e^{z} - y}\right)}{t} \]
    8. *-rgt-identity82.1%

      \[\leadsto x - \frac{\mathsf{log1p}\left(y \cdot e^{z} - \color{blue}{y \cdot 1}\right)}{t} \]
    9. distribute-lft-out--82.1%

      \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{y \cdot \left(e^{z} - 1\right)}\right)}{t} \]
    10. expm1-def98.4%

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

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

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

Alternative 2: 86.9% accurate, 1.9× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;y \leq -2.3 \cdot 10^{+177}:\\ \;\;\;\;x\\ \mathbf{else}:\\ \;\;\;\;x + \frac{-1}{\frac{1}{y \cdot \frac{\mathsf{expm1}\left(z\right)}{t}}}\\ \end{array} \end{array} \]
(FPCore (x y z t)
 :precision binary64
 (if (<= y -2.3e+177) x (+ x (/ -1.0 (/ 1.0 (* y (/ (expm1 z) t)))))))
double code(double x, double y, double z, double t) {
	double tmp;
	if (y <= -2.3e+177) {
		tmp = x;
	} else {
		tmp = x + (-1.0 / (1.0 / (y * (expm1(z) / t))));
	}
	return tmp;
}
public static double code(double x, double y, double z, double t) {
	double tmp;
	if (y <= -2.3e+177) {
		tmp = x;
	} else {
		tmp = x + (-1.0 / (1.0 / (y * (Math.expm1(z) / t))));
	}
	return tmp;
}
def code(x, y, z, t):
	tmp = 0
	if y <= -2.3e+177:
		tmp = x
	else:
		tmp = x + (-1.0 / (1.0 / (y * (math.expm1(z) / t))))
	return tmp
function code(x, y, z, t)
	tmp = 0.0
	if (y <= -2.3e+177)
		tmp = x;
	else
		tmp = Float64(x + Float64(-1.0 / Float64(1.0 / Float64(y * Float64(expm1(z) / t)))));
	end
	return tmp
end
code[x_, y_, z_, t_] := If[LessEqual[y, -2.3e+177], x, N[(x + N[(-1.0 / N[(1.0 / N[(y * N[(N[(Exp[z] - 1), $MachinePrecision] / t), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;y \leq -2.3 \cdot 10^{+177}:\\
\;\;\;\;x\\

\mathbf{else}:\\
\;\;\;\;x + \frac{-1}{\frac{1}{y \cdot \frac{\mathsf{expm1}\left(z\right)}{t}}}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if y < -2.2999999999999999e177

    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. sub-neg50.6%

        \[\leadsto x - \frac{\log \left(\color{blue}{\left(1 + \left(-y\right)\right)} + y \cdot e^{z}\right)}{t} \]
      2. associate-+l+77.5%

        \[\leadsto x - \frac{\log \color{blue}{\left(1 + \left(\left(-y\right) + y \cdot e^{z}\right)\right)}}{t} \]
      3. cancel-sign-sub77.5%

        \[\leadsto x - \frac{\log \left(1 + \color{blue}{\left(\left(-y\right) - \left(-y\right) \cdot e^{z}\right)}\right)}{t} \]
      4. log1p-def77.5%

        \[\leadsto x - \frac{\color{blue}{\mathsf{log1p}\left(\left(-y\right) - \left(-y\right) \cdot e^{z}\right)}}{t} \]
      5. cancel-sign-sub77.5%

        \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{\left(-y\right) + y \cdot e^{z}}\right)}{t} \]
      6. +-commutative77.5%

        \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{y \cdot e^{z} + \left(-y\right)}\right)}{t} \]
      7. unsub-neg77.5%

        \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{y \cdot e^{z} - y}\right)}{t} \]
      8. *-rgt-identity77.5%

        \[\leadsto x - \frac{\mathsf{log1p}\left(y \cdot e^{z} - \color{blue}{y \cdot 1}\right)}{t} \]
      9. distribute-lft-out--77.5%

        \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{y \cdot \left(e^{z} - 1\right)}\right)}{t} \]
      10. 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 x around inf 56.8%

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

    if -2.2999999999999999e177 < y

    1. Initial program 60.6%

      \[x - \frac{\log \left(\left(1 - y\right) + y \cdot e^{z}\right)}{t} \]
    2. Step-by-step derivation
      1. sub-neg60.6%

        \[\leadsto x - \frac{\log \left(\color{blue}{\left(1 + \left(-y\right)\right)} + y \cdot e^{z}\right)}{t} \]
      2. associate-+l+76.6%

        \[\leadsto x - \frac{\log \color{blue}{\left(1 + \left(\left(-y\right) + y \cdot e^{z}\right)\right)}}{t} \]
      3. cancel-sign-sub76.6%

        \[\leadsto x - \frac{\log \left(1 + \color{blue}{\left(\left(-y\right) - \left(-y\right) \cdot e^{z}\right)}\right)}{t} \]
      4. log1p-def82.7%

        \[\leadsto x - \frac{\color{blue}{\mathsf{log1p}\left(\left(-y\right) - \left(-y\right) \cdot e^{z}\right)}}{t} \]
      5. cancel-sign-sub82.7%

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

        \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{y \cdot e^{z} + \left(-y\right)}\right)}{t} \]
      7. unsub-neg82.7%

        \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{y \cdot e^{z} - y}\right)}{t} \]
      8. *-rgt-identity82.7%

        \[\leadsto x - \frac{\mathsf{log1p}\left(y \cdot e^{z} - \color{blue}{y \cdot 1}\right)}{t} \]
      9. distribute-lft-out--82.7%

        \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{y \cdot \left(e^{z} - 1\right)}\right)}{t} \]
      10. expm1-def98.3%

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

      \[\leadsto \color{blue}{x - \frac{\mathsf{log1p}\left(y \cdot \mathsf{expm1}\left(z\right)\right)}{t}} \]
    4. Taylor expanded in y around 0 78.5%

      \[\leadsto x - \color{blue}{\frac{y \cdot \left(e^{z} - 1\right)}{t}} \]
    5. Step-by-step derivation
      1. clear-num78.5%

        \[\leadsto x - \color{blue}{\frac{1}{\frac{t}{y \cdot \left(e^{z} - 1\right)}}} \]
      2. inv-pow78.5%

        \[\leadsto x - \color{blue}{{\left(\frac{t}{y \cdot \left(e^{z} - 1\right)}\right)}^{-1}} \]
      3. expm1-udef89.5%

        \[\leadsto x - {\left(\frac{t}{y \cdot \color{blue}{\mathsf{expm1}\left(z\right)}}\right)}^{-1} \]
    6. Applied egg-rr89.5%

      \[\leadsto x - \color{blue}{{\left(\frac{t}{y \cdot \mathsf{expm1}\left(z\right)}\right)}^{-1}} \]
    7. Step-by-step derivation
      1. unpow-189.5%

        \[\leadsto x - \color{blue}{\frac{1}{\frac{t}{y \cdot \mathsf{expm1}\left(z\right)}}} \]
      2. associate-/r*89.7%

        \[\leadsto x - \frac{1}{\color{blue}{\frac{\frac{t}{y}}{\mathsf{expm1}\left(z\right)}}} \]
    8. Simplified89.7%

      \[\leadsto x - \color{blue}{\frac{1}{\frac{\frac{t}{y}}{\mathsf{expm1}\left(z\right)}}} \]
    9. Step-by-step derivation
      1. clear-num89.8%

        \[\leadsto x - \frac{1}{\color{blue}{\frac{1}{\frac{\mathsf{expm1}\left(z\right)}{\frac{t}{y}}}}} \]
      2. inv-pow89.8%

        \[\leadsto x - \frac{1}{\color{blue}{{\left(\frac{\mathsf{expm1}\left(z\right)}{\frac{t}{y}}\right)}^{-1}}} \]
      3. div-inv89.3%

        \[\leadsto x - \frac{1}{{\color{blue}{\left(\mathsf{expm1}\left(z\right) \cdot \frac{1}{\frac{t}{y}}\right)}}^{-1}} \]
      4. clear-num89.3%

        \[\leadsto x - \frac{1}{{\left(\mathsf{expm1}\left(z\right) \cdot \color{blue}{\frac{y}{t}}\right)}^{-1}} \]
    10. Applied egg-rr89.3%

      \[\leadsto x - \frac{1}{\color{blue}{{\left(\mathsf{expm1}\left(z\right) \cdot \frac{y}{t}\right)}^{-1}}} \]
    11. Step-by-step derivation
      1. unpow-189.3%

        \[\leadsto x - \frac{1}{\color{blue}{\frac{1}{\mathsf{expm1}\left(z\right) \cdot \frac{y}{t}}}} \]
      2. *-commutative89.3%

        \[\leadsto x - \frac{1}{\frac{1}{\color{blue}{\frac{y}{t} \cdot \mathsf{expm1}\left(z\right)}}} \]
      3. associate-*l/89.5%

        \[\leadsto x - \frac{1}{\frac{1}{\color{blue}{\frac{y \cdot \mathsf{expm1}\left(z\right)}{t}}}} \]
      4. associate-*r/90.0%

        \[\leadsto x - \frac{1}{\frac{1}{\color{blue}{y \cdot \frac{\mathsf{expm1}\left(z\right)}{t}}}} \]
    12. Simplified90.0%

      \[\leadsto x - \frac{1}{\color{blue}{\frac{1}{y \cdot \frac{\mathsf{expm1}\left(z\right)}{t}}}} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification86.3%

    \[\leadsto \begin{array}{l} \mathbf{if}\;y \leq -2.3 \cdot 10^{+177}:\\ \;\;\;\;x\\ \mathbf{else}:\\ \;\;\;\;x + \frac{-1}{\frac{1}{y \cdot \frac{\mathsf{expm1}\left(z\right)}{t}}}\\ \end{array} \]

Alternative 3: 84.9% accurate, 1.9× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;y \leq -2 \cdot 10^{+176}:\\ \;\;\;\;x\\ \mathbf{else}:\\ \;\;\;\;x - \frac{\mathsf{expm1}\left(z\right)}{\frac{t}{y}}\\ \end{array} \end{array} \]
(FPCore (x y z t)
 :precision binary64
 (if (<= y -2e+176) x (- x (/ (expm1 z) (/ t y)))))
double code(double x, double y, double z, double t) {
	double tmp;
	if (y <= -2e+176) {
		tmp = x;
	} else {
		tmp = x - (expm1(z) / (t / y));
	}
	return tmp;
}
public static double code(double x, double y, double z, double t) {
	double tmp;
	if (y <= -2e+176) {
		tmp = x;
	} else {
		tmp = x - (Math.expm1(z) / (t / y));
	}
	return tmp;
}
def code(x, y, z, t):
	tmp = 0
	if y <= -2e+176:
		tmp = x
	else:
		tmp = x - (math.expm1(z) / (t / y))
	return tmp
function code(x, y, z, t)
	tmp = 0.0
	if (y <= -2e+176)
		tmp = x;
	else
		tmp = Float64(x - Float64(expm1(z) / Float64(t / y)));
	end
	return tmp
end
code[x_, y_, z_, t_] := If[LessEqual[y, -2e+176], x, N[(x - N[(N[(Exp[z] - 1), $MachinePrecision] / N[(t / y), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;y \leq -2 \cdot 10^{+176}:\\
\;\;\;\;x\\

\mathbf{else}:\\
\;\;\;\;x - \frac{\mathsf{expm1}\left(z\right)}{\frac{t}{y}}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if y < -2e176

    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. sub-neg50.6%

        \[\leadsto x - \frac{\log \left(\color{blue}{\left(1 + \left(-y\right)\right)} + y \cdot e^{z}\right)}{t} \]
      2. associate-+l+77.5%

        \[\leadsto x - \frac{\log \color{blue}{\left(1 + \left(\left(-y\right) + y \cdot e^{z}\right)\right)}}{t} \]
      3. cancel-sign-sub77.5%

        \[\leadsto x - \frac{\log \left(1 + \color{blue}{\left(\left(-y\right) - \left(-y\right) \cdot e^{z}\right)}\right)}{t} \]
      4. log1p-def77.5%

        \[\leadsto x - \frac{\color{blue}{\mathsf{log1p}\left(\left(-y\right) - \left(-y\right) \cdot e^{z}\right)}}{t} \]
      5. cancel-sign-sub77.5%

        \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{\left(-y\right) + y \cdot e^{z}}\right)}{t} \]
      6. +-commutative77.5%

        \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{y \cdot e^{z} + \left(-y\right)}\right)}{t} \]
      7. unsub-neg77.5%

        \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{y \cdot e^{z} - y}\right)}{t} \]
      8. *-rgt-identity77.5%

        \[\leadsto x - \frac{\mathsf{log1p}\left(y \cdot e^{z} - \color{blue}{y \cdot 1}\right)}{t} \]
      9. distribute-lft-out--77.5%

        \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{y \cdot \left(e^{z} - 1\right)}\right)}{t} \]
      10. 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 x around inf 56.8%

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

    if -2e176 < y

    1. Initial program 60.6%

      \[x - \frac{\log \left(\left(1 - y\right) + y \cdot e^{z}\right)}{t} \]
    2. Step-by-step derivation
      1. sub-neg60.6%

        \[\leadsto x - \frac{\log \left(\color{blue}{\left(1 + \left(-y\right)\right)} + y \cdot e^{z}\right)}{t} \]
      2. associate-+l+76.6%

        \[\leadsto x - \frac{\log \color{blue}{\left(1 + \left(\left(-y\right) + y \cdot e^{z}\right)\right)}}{t} \]
      3. cancel-sign-sub76.6%

        \[\leadsto x - \frac{\log \left(1 + \color{blue}{\left(\left(-y\right) - \left(-y\right) \cdot e^{z}\right)}\right)}{t} \]
      4. log1p-def82.7%

        \[\leadsto x - \frac{\color{blue}{\mathsf{log1p}\left(\left(-y\right) - \left(-y\right) \cdot e^{z}\right)}}{t} \]
      5. cancel-sign-sub82.7%

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

        \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{y \cdot e^{z} + \left(-y\right)}\right)}{t} \]
      7. unsub-neg82.7%

        \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{y \cdot e^{z} - y}\right)}{t} \]
      8. *-rgt-identity82.7%

        \[\leadsto x - \frac{\mathsf{log1p}\left(y \cdot e^{z} - \color{blue}{y \cdot 1}\right)}{t} \]
      9. distribute-lft-out--82.7%

        \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{y \cdot \left(e^{z} - 1\right)}\right)}{t} \]
      10. expm1-def98.3%

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

      \[\leadsto \color{blue}{x - \frac{\mathsf{log1p}\left(y \cdot \mathsf{expm1}\left(z\right)\right)}{t}} \]
    4. Taylor expanded in y around 0 78.5%

      \[\leadsto x - \color{blue}{\frac{y \cdot \left(e^{z} - 1\right)}{t}} \]
    5. Step-by-step derivation
      1. clear-num78.5%

        \[\leadsto x - \color{blue}{\frac{1}{\frac{t}{y \cdot \left(e^{z} - 1\right)}}} \]
      2. inv-pow78.5%

        \[\leadsto x - \color{blue}{{\left(\frac{t}{y \cdot \left(e^{z} - 1\right)}\right)}^{-1}} \]
      3. expm1-udef89.5%

        \[\leadsto x - {\left(\frac{t}{y \cdot \color{blue}{\mathsf{expm1}\left(z\right)}}\right)}^{-1} \]
    6. Applied egg-rr89.5%

      \[\leadsto x - \color{blue}{{\left(\frac{t}{y \cdot \mathsf{expm1}\left(z\right)}\right)}^{-1}} \]
    7. Step-by-step derivation
      1. unpow-189.5%

        \[\leadsto x - \color{blue}{\frac{1}{\frac{t}{y \cdot \mathsf{expm1}\left(z\right)}}} \]
      2. associate-/r*89.7%

        \[\leadsto x - \frac{1}{\color{blue}{\frac{\frac{t}{y}}{\mathsf{expm1}\left(z\right)}}} \]
    8. Simplified89.7%

      \[\leadsto x - \color{blue}{\frac{1}{\frac{\frac{t}{y}}{\mathsf{expm1}\left(z\right)}}} \]
    9. Step-by-step derivation
      1. clear-num89.8%

        \[\leadsto x - \color{blue}{\frac{\mathsf{expm1}\left(z\right)}{\frac{t}{y}}} \]
      2. add-cube-cbrt89.5%

        \[\leadsto x - \frac{\color{blue}{\left(\sqrt[3]{\mathsf{expm1}\left(z\right)} \cdot \sqrt[3]{\mathsf{expm1}\left(z\right)}\right) \cdot \sqrt[3]{\mathsf{expm1}\left(z\right)}}}{\frac{t}{y}} \]
      3. *-un-lft-identity89.5%

        \[\leadsto x - \frac{\left(\sqrt[3]{\mathsf{expm1}\left(z\right)} \cdot \sqrt[3]{\mathsf{expm1}\left(z\right)}\right) \cdot \sqrt[3]{\mathsf{expm1}\left(z\right)}}{\color{blue}{1 \cdot \frac{t}{y}}} \]
      4. times-frac89.5%

        \[\leadsto x - \color{blue}{\frac{\sqrt[3]{\mathsf{expm1}\left(z\right)} \cdot \sqrt[3]{\mathsf{expm1}\left(z\right)}}{1} \cdot \frac{\sqrt[3]{\mathsf{expm1}\left(z\right)}}{\frac{t}{y}}} \]
      5. pow289.5%

        \[\leadsto x - \frac{\color{blue}{{\left(\sqrt[3]{\mathsf{expm1}\left(z\right)}\right)}^{2}}}{1} \cdot \frac{\sqrt[3]{\mathsf{expm1}\left(z\right)}}{\frac{t}{y}} \]
    10. Applied egg-rr89.5%

      \[\leadsto x - \color{blue}{\frac{{\left(\sqrt[3]{\mathsf{expm1}\left(z\right)}\right)}^{2}}{1} \cdot \frac{\sqrt[3]{\mathsf{expm1}\left(z\right)}}{\frac{t}{y}}} \]
    11. Step-by-step derivation
      1. /-rgt-identity89.5%

        \[\leadsto x - \color{blue}{{\left(\sqrt[3]{\mathsf{expm1}\left(z\right)}\right)}^{2}} \cdot \frac{\sqrt[3]{\mathsf{expm1}\left(z\right)}}{\frac{t}{y}} \]
      2. associate-*r/89.5%

        \[\leadsto x - \color{blue}{\frac{{\left(\sqrt[3]{\mathsf{expm1}\left(z\right)}\right)}^{2} \cdot \sqrt[3]{\mathsf{expm1}\left(z\right)}}{\frac{t}{y}}} \]
      3. unpow289.5%

        \[\leadsto x - \frac{\color{blue}{\left(\sqrt[3]{\mathsf{expm1}\left(z\right)} \cdot \sqrt[3]{\mathsf{expm1}\left(z\right)}\right)} \cdot \sqrt[3]{\mathsf{expm1}\left(z\right)}}{\frac{t}{y}} \]
      4. rem-3cbrt-lft89.8%

        \[\leadsto x - \frac{\color{blue}{\mathsf{expm1}\left(z\right)}}{\frac{t}{y}} \]
    12. Simplified89.8%

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

    \[\leadsto \begin{array}{l} \mathbf{if}\;y \leq -2 \cdot 10^{+176}:\\ \;\;\;\;x\\ \mathbf{else}:\\ \;\;\;\;x - \frac{\mathsf{expm1}\left(z\right)}{\frac{t}{y}}\\ \end{array} \]

Alternative 4: 79.2% accurate, 23.3× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;z \leq -0.0114:\\ \;\;\;\;x\\ \mathbf{else}:\\ \;\;\;\;x - z \cdot \frac{y}{t}\\ \end{array} \end{array} \]
(FPCore (x y z t)
 :precision binary64
 (if (<= z -0.0114) x (- x (* z (/ y t)))))
double code(double x, double y, double z, double t) {
	double tmp;
	if (z <= -0.0114) {
		tmp = x;
	} else {
		tmp = x - (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) :: tmp
    if (z <= (-0.0114d0)) then
        tmp = x
    else
        tmp = x - (z * (y / t))
    end if
    code = tmp
end function
public static double code(double x, double y, double z, double t) {
	double tmp;
	if (z <= -0.0114) {
		tmp = x;
	} else {
		tmp = x - (z * (y / t));
	}
	return tmp;
}
def code(x, y, z, t):
	tmp = 0
	if z <= -0.0114:
		tmp = x
	else:
		tmp = x - (z * (y / t))
	return tmp
function code(x, y, z, t)
	tmp = 0.0
	if (z <= -0.0114)
		tmp = x;
	else
		tmp = Float64(x - Float64(z * Float64(y / t)));
	end
	return tmp
end
function tmp_2 = code(x, y, z, t)
	tmp = 0.0;
	if (z <= -0.0114)
		tmp = x;
	else
		tmp = x - (z * (y / t));
	end
	tmp_2 = tmp;
end
code[x_, y_, z_, t_] := If[LessEqual[z, -0.0114], x, N[(x - N[(z * N[(y / t), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;z \leq -0.0114:\\
\;\;\;\;x\\

\mathbf{else}:\\
\;\;\;\;x - z \cdot \frac{y}{t}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if z < -0.0114

    1. Initial program 84.7%

      \[x - \frac{\log \left(\left(1 - y\right) + y \cdot e^{z}\right)}{t} \]
    2. Step-by-step derivation
      1. sub-neg84.7%

        \[\leadsto x - \frac{\log \left(\color{blue}{\left(1 + \left(-y\right)\right)} + y \cdot e^{z}\right)}{t} \]
      2. associate-+l+84.7%

        \[\leadsto x - \frac{\log \color{blue}{\left(1 + \left(\left(-y\right) + y \cdot e^{z}\right)\right)}}{t} \]
      3. cancel-sign-sub84.7%

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

        \[\leadsto x - \frac{\color{blue}{\mathsf{log1p}\left(\left(-y\right) - \left(-y\right) \cdot e^{z}\right)}}{t} \]
      5. cancel-sign-sub100.0%

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

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

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

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

        \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{y \cdot \left(e^{z} - 1\right)}\right)}{t} \]
      10. 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 x around inf 68.0%

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

    if -0.0114 < z

    1. Initial program 47.9%

      \[x - \frac{\log \left(\left(1 - y\right) + y \cdot e^{z}\right)}{t} \]
    2. Step-by-step derivation
      1. sub-neg47.9%

        \[\leadsto x - \frac{\log \left(\color{blue}{\left(1 + \left(-y\right)\right)} + y \cdot e^{z}\right)}{t} \]
      2. associate-+l+73.0%

        \[\leadsto x - \frac{\log \color{blue}{\left(1 + \left(\left(-y\right) + y \cdot e^{z}\right)\right)}}{t} \]
      3. cancel-sign-sub73.0%

        \[\leadsto x - \frac{\log \left(1 + \color{blue}{\left(\left(-y\right) - \left(-y\right) \cdot e^{z}\right)}\right)}{t} \]
      4. log1p-def73.8%

        \[\leadsto x - \frac{\color{blue}{\mathsf{log1p}\left(\left(-y\right) - \left(-y\right) \cdot e^{z}\right)}}{t} \]
      5. cancel-sign-sub73.8%

        \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{\left(-y\right) + y \cdot e^{z}}\right)}{t} \]
      6. +-commutative73.8%

        \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{y \cdot e^{z} + \left(-y\right)}\right)}{t} \]
      7. unsub-neg73.8%

        \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{y \cdot e^{z} - y}\right)}{t} \]
      8. *-rgt-identity73.8%

        \[\leadsto x - \frac{\mathsf{log1p}\left(y \cdot e^{z} - \color{blue}{y \cdot 1}\right)}{t} \]
      9. distribute-lft-out--73.8%

        \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{y \cdot \left(e^{z} - 1\right)}\right)}{t} \]
      10. expm1-def97.7%

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

      \[\leadsto \color{blue}{x - \frac{\mathsf{log1p}\left(y \cdot \mathsf{expm1}\left(z\right)\right)}{t}} \]
    4. Taylor expanded in z around 0 86.4%

      \[\leadsto x - \color{blue}{\frac{y \cdot z}{t}} \]
    5. Step-by-step derivation
      1. associate-/l*87.3%

        \[\leadsto x - \color{blue}{\frac{y}{\frac{t}{z}}} \]
      2. associate-/r/85.6%

        \[\leadsto x - \color{blue}{\frac{y}{t} \cdot z} \]
    6. Simplified85.6%

      \[\leadsto x - \color{blue}{\frac{y}{t} \cdot z} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification80.0%

    \[\leadsto \begin{array}{l} \mathbf{if}\;z \leq -0.0114:\\ \;\;\;\;x\\ \mathbf{else}:\\ \;\;\;\;x - z \cdot \frac{y}{t}\\ \end{array} \]

Alternative 5: 82.3% accurate, 23.3× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;z \leq -0.000106:\\ \;\;\;\;x\\ \mathbf{else}:\\ \;\;\;\;x - \frac{y}{\frac{t}{z}}\\ \end{array} \end{array} \]
(FPCore (x y z t)
 :precision binary64
 (if (<= z -0.000106) x (- x (/ y (/ t z)))))
double code(double x, double y, double z, double t) {
	double tmp;
	if (z <= -0.000106) {
		tmp = x;
	} else {
		tmp = x - (y / (t / 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 <= (-0.000106d0)) then
        tmp = x
    else
        tmp = x - (y / (t / z))
    end if
    code = tmp
end function
public static double code(double x, double y, double z, double t) {
	double tmp;
	if (z <= -0.000106) {
		tmp = x;
	} else {
		tmp = x - (y / (t / z));
	}
	return tmp;
}
def code(x, y, z, t):
	tmp = 0
	if z <= -0.000106:
		tmp = x
	else:
		tmp = x - (y / (t / z))
	return tmp
function code(x, y, z, t)
	tmp = 0.0
	if (z <= -0.000106)
		tmp = x;
	else
		tmp = Float64(x - Float64(y / Float64(t / z)));
	end
	return tmp
end
function tmp_2 = code(x, y, z, t)
	tmp = 0.0;
	if (z <= -0.000106)
		tmp = x;
	else
		tmp = x - (y / (t / z));
	end
	tmp_2 = tmp;
end
code[x_, y_, z_, t_] := If[LessEqual[z, -0.000106], x, N[(x - N[(y / N[(t / z), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;z \leq -0.000106:\\
\;\;\;\;x\\

\mathbf{else}:\\
\;\;\;\;x - \frac{y}{\frac{t}{z}}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if z < -1.06e-4

    1. Initial program 84.7%

      \[x - \frac{\log \left(\left(1 - y\right) + y \cdot e^{z}\right)}{t} \]
    2. Step-by-step derivation
      1. sub-neg84.7%

        \[\leadsto x - \frac{\log \left(\color{blue}{\left(1 + \left(-y\right)\right)} + y \cdot e^{z}\right)}{t} \]
      2. associate-+l+84.7%

        \[\leadsto x - \frac{\log \color{blue}{\left(1 + \left(\left(-y\right) + y \cdot e^{z}\right)\right)}}{t} \]
      3. cancel-sign-sub84.7%

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

        \[\leadsto x - \frac{\color{blue}{\mathsf{log1p}\left(\left(-y\right) - \left(-y\right) \cdot e^{z}\right)}}{t} \]
      5. cancel-sign-sub100.0%

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

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

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

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

        \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{y \cdot \left(e^{z} - 1\right)}\right)}{t} \]
      10. 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 x around inf 68.0%

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

    if -1.06e-4 < z

    1. Initial program 47.9%

      \[x - \frac{\log \left(\left(1 - y\right) + y \cdot e^{z}\right)}{t} \]
    2. Step-by-step derivation
      1. sub-neg47.9%

        \[\leadsto x - \frac{\log \left(\color{blue}{\left(1 + \left(-y\right)\right)} + y \cdot e^{z}\right)}{t} \]
      2. associate-+l+73.0%

        \[\leadsto x - \frac{\log \color{blue}{\left(1 + \left(\left(-y\right) + y \cdot e^{z}\right)\right)}}{t} \]
      3. cancel-sign-sub73.0%

        \[\leadsto x - \frac{\log \left(1 + \color{blue}{\left(\left(-y\right) - \left(-y\right) \cdot e^{z}\right)}\right)}{t} \]
      4. log1p-def73.8%

        \[\leadsto x - \frac{\color{blue}{\mathsf{log1p}\left(\left(-y\right) - \left(-y\right) \cdot e^{z}\right)}}{t} \]
      5. cancel-sign-sub73.8%

        \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{\left(-y\right) + y \cdot e^{z}}\right)}{t} \]
      6. +-commutative73.8%

        \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{y \cdot e^{z} + \left(-y\right)}\right)}{t} \]
      7. unsub-neg73.8%

        \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{y \cdot e^{z} - y}\right)}{t} \]
      8. *-rgt-identity73.8%

        \[\leadsto x - \frac{\mathsf{log1p}\left(y \cdot e^{z} - \color{blue}{y \cdot 1}\right)}{t} \]
      9. distribute-lft-out--73.8%

        \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{y \cdot \left(e^{z} - 1\right)}\right)}{t} \]
      10. expm1-def97.7%

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

      \[\leadsto \color{blue}{x - \frac{\mathsf{log1p}\left(y \cdot \mathsf{expm1}\left(z\right)\right)}{t}} \]
    4. Taylor expanded in z around 0 86.4%

      \[\leadsto x - \color{blue}{\frac{y \cdot z}{t}} \]
    5. Step-by-step derivation
      1. associate-/l*87.3%

        \[\leadsto x - \color{blue}{\frac{y}{\frac{t}{z}}} \]
    6. Simplified87.3%

      \[\leadsto x - \color{blue}{\frac{y}{\frac{t}{z}}} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification81.1%

    \[\leadsto \begin{array}{l} \mathbf{if}\;z \leq -0.000106:\\ \;\;\;\;x\\ \mathbf{else}:\\ \;\;\;\;x - \frac{y}{\frac{t}{z}}\\ \end{array} \]

Alternative 6: 71.6% 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 59.5%

    \[x - \frac{\log \left(\left(1 - y\right) + y \cdot e^{z}\right)}{t} \]
  2. Step-by-step derivation
    1. sub-neg59.5%

      \[\leadsto x - \frac{\log \left(\color{blue}{\left(1 + \left(-y\right)\right)} + y \cdot e^{z}\right)}{t} \]
    2. associate-+l+76.7%

      \[\leadsto x - \frac{\log \color{blue}{\left(1 + \left(\left(-y\right) + y \cdot e^{z}\right)\right)}}{t} \]
    3. cancel-sign-sub76.7%

      \[\leadsto x - \frac{\log \left(1 + \color{blue}{\left(\left(-y\right) - \left(-y\right) \cdot e^{z}\right)}\right)}{t} \]
    4. log1p-def82.1%

      \[\leadsto x - \frac{\color{blue}{\mathsf{log1p}\left(\left(-y\right) - \left(-y\right) \cdot e^{z}\right)}}{t} \]
    5. cancel-sign-sub82.1%

      \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{\left(-y\right) + y \cdot e^{z}}\right)}{t} \]
    6. +-commutative82.1%

      \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{y \cdot e^{z} + \left(-y\right)}\right)}{t} \]
    7. unsub-neg82.1%

      \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{y \cdot e^{z} - y}\right)}{t} \]
    8. *-rgt-identity82.1%

      \[\leadsto x - \frac{\mathsf{log1p}\left(y \cdot e^{z} - \color{blue}{y \cdot 1}\right)}{t} \]
    9. distribute-lft-out--82.1%

      \[\leadsto x - \frac{\mathsf{log1p}\left(\color{blue}{y \cdot \left(e^{z} - 1\right)}\right)}{t} \]
    10. expm1-def98.4%

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

    \[\leadsto \color{blue}{x - \frac{\mathsf{log1p}\left(y \cdot \mathsf{expm1}\left(z\right)\right)}{t}} \]
  4. Taylor expanded in x around inf 71.1%

    \[\leadsto \color{blue}{x} \]
  5. Final simplification71.1%

    \[\leadsto x \]

Developer target: 74.8% 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 2023322 
(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)))