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

Percentage Accurate: 61.1% → 99.3%
Time: 18.3s
Alternatives: 8
Speedup: 11.3×

Specification

?
\[\begin{array}{l} \\ x - \frac{\log \left(\left(1 - y\right) + y \cdot e^{z}\right)}{t} \end{array} \]
(FPCore (x y z t)
 :precision binary64
 (- x (/ (log (+ (- 1.0 y) (* y (exp z)))) t)))
double code(double x, double y, double z, double t) {
	return x - (log(((1.0 - y) + (y * exp(z)))) / t);
}
real(8) function code(x, y, z, t)
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    real(8), intent (in) :: z
    real(8), intent (in) :: t
    code = x - (log(((1.0d0 - y) + (y * exp(z)))) / t)
end function
public static double code(double x, double y, double z, double t) {
	return x - (Math.log(((1.0 - y) + (y * Math.exp(z)))) / t);
}
def code(x, y, z, t):
	return x - (math.log(((1.0 - y) + (y * math.exp(z)))) / t)
function code(x, y, z, t)
	return Float64(x - Float64(log(Float64(Float64(1.0 - y) + Float64(y * exp(z)))) / t))
end
function tmp = code(x, y, z, t)
	tmp = x - (log(((1.0 - y) + (y * exp(z)))) / t);
end
code[x_, y_, z_, t_] := N[(x - N[(N[Log[N[(N[(1.0 - y), $MachinePrecision] + N[(y * N[Exp[z], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] / t), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

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

Sampling outcomes in binary64 precision:

Local Percentage Accuracy vs ?

The average percentage accuracy by input value. Horizontal axis shows value of an input variable; the variable is choosen in the title. Vertical axis is accuracy; higher is better. Red represent the original program, while blue represents Herbie's suggestion. These can be toggled with buttons below the plot. The line is an average while dots represent individual samples.

Accuracy vs Speed?

Herbie found 8 alternatives:

AlternativeAccuracySpeedup
The accuracy (vertical axis) and speed (horizontal axis) of each alternatives. Up and to the right is better. The red square shows the initial program, and each blue circle shows an alternative.The line shows the best available speed-accuracy tradeoffs.

Initial Program: 61.1% 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: 99.3% accurate, 0.5× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_1 := e^{z} \cdot y + \left(1 - y\right)\\ \mathbf{if}\;t\_1 \leq 0:\\ \;\;\;\;x - \frac{1}{\frac{t}{\mathsf{log1p}\left(y \cdot z\right)}}\\ \mathbf{elif}\;t\_1 \leq 2:\\ \;\;\;\;x - \frac{1}{\frac{\mathsf{fma}\left(y \cdot t, 0.5, \frac{t}{\mathsf{expm1}\left(z\right)}\right)}{y}}\\ \mathbf{else}:\\ \;\;\;\;x - \frac{\log t\_1}{t}\\ \end{array} \end{array} \]
(FPCore (x y z t)
 :precision binary64
 (let* ((t_1 (+ (* (exp z) y) (- 1.0 y))))
   (if (<= t_1 0.0)
     (- x (/ 1.0 (/ t (log1p (* y z)))))
     (if (<= t_1 2.0)
       (- x (/ 1.0 (/ (fma (* y t) 0.5 (/ t (expm1 z))) y)))
       (- x (/ (log t_1) t))))))
double code(double x, double y, double z, double t) {
	double t_1 = (exp(z) * y) + (1.0 - y);
	double tmp;
	if (t_1 <= 0.0) {
		tmp = x - (1.0 / (t / log1p((y * z))));
	} else if (t_1 <= 2.0) {
		tmp = x - (1.0 / (fma((y * t), 0.5, (t / expm1(z))) / y));
	} else {
		tmp = x - (log(t_1) / t);
	}
	return tmp;
}
function code(x, y, z, t)
	t_1 = Float64(Float64(exp(z) * y) + Float64(1.0 - y))
	tmp = 0.0
	if (t_1 <= 0.0)
		tmp = Float64(x - Float64(1.0 / Float64(t / log1p(Float64(y * z)))));
	elseif (t_1 <= 2.0)
		tmp = Float64(x - Float64(1.0 / Float64(fma(Float64(y * t), 0.5, Float64(t / expm1(z))) / y)));
	else
		tmp = Float64(x - Float64(log(t_1) / t));
	end
	return tmp
end
code[x_, y_, z_, t_] := Block[{t$95$1 = N[(N[(N[Exp[z], $MachinePrecision] * y), $MachinePrecision] + N[(1.0 - y), $MachinePrecision]), $MachinePrecision]}, If[LessEqual[t$95$1, 0.0], N[(x - N[(1.0 / N[(t / N[Log[1 + N[(y * z), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], If[LessEqual[t$95$1, 2.0], N[(x - N[(1.0 / N[(N[(N[(y * t), $MachinePrecision] * 0.5 + N[(t / N[(Exp[z] - 1), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / y), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(x - N[(N[Log[t$95$1], $MachinePrecision] / t), $MachinePrecision]), $MachinePrecision]]]]
\begin{array}{l}

\\
\begin{array}{l}
t_1 := e^{z} \cdot y + \left(1 - y\right)\\
\mathbf{if}\;t\_1 \leq 0:\\
\;\;\;\;x - \frac{1}{\frac{t}{\mathsf{log1p}\left(y \cdot z\right)}}\\

\mathbf{elif}\;t\_1 \leq 2:\\
\;\;\;\;x - \frac{1}{\frac{\mathsf{fma}\left(y \cdot t, 0.5, \frac{t}{\mathsf{expm1}\left(z\right)}\right)}{y}}\\

\mathbf{else}:\\
\;\;\;\;x - \frac{\log t\_1}{t}\\


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if (+.f64 (-.f64 #s(literal 1 binary64) y) (*.f64 y (exp.f64 z))) < 0.0

    1. Initial program 1.9%

      \[x - \frac{\log \left(\left(1 - y\right) + y \cdot e^{z}\right)}{t} \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. lift-/.f64N/A

        \[\leadsto x - \color{blue}{\frac{\log \left(\left(1 - y\right) + y \cdot e^{z}\right)}{t}} \]
      2. clear-numN/A

        \[\leadsto x - \color{blue}{\frac{1}{\frac{t}{\log \left(\left(1 - y\right) + y \cdot e^{z}\right)}}} \]
      3. lower-/.f64N/A

        \[\leadsto x - \color{blue}{\frac{1}{\frac{t}{\log \left(\left(1 - y\right) + y \cdot e^{z}\right)}}} \]
      4. lower-/.f641.9

        \[\leadsto x - \frac{1}{\color{blue}{\frac{t}{\log \left(\left(1 - y\right) + y \cdot e^{z}\right)}}} \]
      5. lift-log.f64N/A

        \[\leadsto x - \frac{1}{\frac{t}{\color{blue}{\log \left(\left(1 - y\right) + y \cdot e^{z}\right)}}} \]
      6. lift-+.f64N/A

        \[\leadsto x - \frac{1}{\frac{t}{\log \color{blue}{\left(\left(1 - y\right) + y \cdot e^{z}\right)}}} \]
      7. lift--.f64N/A

        \[\leadsto x - \frac{1}{\frac{t}{\log \left(\color{blue}{\left(1 - y\right)} + y \cdot e^{z}\right)}} \]
      8. sub-negN/A

        \[\leadsto x - \frac{1}{\frac{t}{\log \left(\color{blue}{\left(1 + \left(\mathsf{neg}\left(y\right)\right)\right)} + y \cdot e^{z}\right)}} \]
      9. associate-+l+N/A

        \[\leadsto x - \frac{1}{\frac{t}{\log \color{blue}{\left(1 + \left(\left(\mathsf{neg}\left(y\right)\right) + y \cdot e^{z}\right)\right)}}} \]
      10. lower-log1p.f64N/A

        \[\leadsto x - \frac{1}{\frac{t}{\color{blue}{\mathsf{log1p}\left(\left(\mathsf{neg}\left(y\right)\right) + y \cdot e^{z}\right)}}} \]
      11. +-commutativeN/A

        \[\leadsto x - \frac{1}{\frac{t}{\mathsf{log1p}\left(\color{blue}{y \cdot e^{z} + \left(\mathsf{neg}\left(y\right)\right)}\right)}} \]
      12. lift-*.f64N/A

        \[\leadsto x - \frac{1}{\frac{t}{\mathsf{log1p}\left(\color{blue}{y \cdot e^{z}} + \left(\mathsf{neg}\left(y\right)\right)\right)}} \]
      13. *-commutativeN/A

        \[\leadsto x - \frac{1}{\frac{t}{\mathsf{log1p}\left(\color{blue}{e^{z} \cdot y} + \left(\mathsf{neg}\left(y\right)\right)\right)}} \]
      14. lower-fma.f64N/A

        \[\leadsto x - \frac{1}{\frac{t}{\mathsf{log1p}\left(\color{blue}{\mathsf{fma}\left(e^{z}, y, \mathsf{neg}\left(y\right)\right)}\right)}} \]
      15. lower-neg.f6458.3

        \[\leadsto x - \frac{1}{\frac{t}{\mathsf{log1p}\left(\mathsf{fma}\left(e^{z}, y, \color{blue}{-y}\right)\right)}} \]
    4. Applied rewrites58.3%

      \[\leadsto x - \color{blue}{\frac{1}{\frac{t}{\mathsf{log1p}\left(\mathsf{fma}\left(e^{z}, y, -y\right)\right)}}} \]
    5. Taylor expanded in z around 0

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

        \[\leadsto x - \frac{1}{\frac{t}{\mathsf{log1p}\left(\color{blue}{z \cdot y}\right)}} \]
      2. lower-*.f6499.8

        \[\leadsto x - \frac{1}{\frac{t}{\mathsf{log1p}\left(\color{blue}{z \cdot y}\right)}} \]
    7. Applied rewrites99.8%

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

    if 0.0 < (+.f64 (-.f64 #s(literal 1 binary64) y) (*.f64 y (exp.f64 z))) < 2

    1. Initial program 81.1%

      \[x - \frac{\log \left(\left(1 - y\right) + y \cdot e^{z}\right)}{t} \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. lift-/.f64N/A

        \[\leadsto x - \color{blue}{\frac{\log \left(\left(1 - y\right) + y \cdot e^{z}\right)}{t}} \]
      2. clear-numN/A

        \[\leadsto x - \color{blue}{\frac{1}{\frac{t}{\log \left(\left(1 - y\right) + y \cdot e^{z}\right)}}} \]
      3. lower-/.f64N/A

        \[\leadsto x - \color{blue}{\frac{1}{\frac{t}{\log \left(\left(1 - y\right) + y \cdot e^{z}\right)}}} \]
      4. lower-/.f6481.1

        \[\leadsto x - \frac{1}{\color{blue}{\frac{t}{\log \left(\left(1 - y\right) + y \cdot e^{z}\right)}}} \]
      5. lift-log.f64N/A

        \[\leadsto x - \frac{1}{\frac{t}{\color{blue}{\log \left(\left(1 - y\right) + y \cdot e^{z}\right)}}} \]
      6. lift-+.f64N/A

        \[\leadsto x - \frac{1}{\frac{t}{\log \color{blue}{\left(\left(1 - y\right) + y \cdot e^{z}\right)}}} \]
      7. lift--.f64N/A

        \[\leadsto x - \frac{1}{\frac{t}{\log \left(\color{blue}{\left(1 - y\right)} + y \cdot e^{z}\right)}} \]
      8. sub-negN/A

        \[\leadsto x - \frac{1}{\frac{t}{\log \left(\color{blue}{\left(1 + \left(\mathsf{neg}\left(y\right)\right)\right)} + y \cdot e^{z}\right)}} \]
      9. associate-+l+N/A

        \[\leadsto x - \frac{1}{\frac{t}{\log \color{blue}{\left(1 + \left(\left(\mathsf{neg}\left(y\right)\right) + y \cdot e^{z}\right)\right)}}} \]
      10. lower-log1p.f64N/A

        \[\leadsto x - \frac{1}{\frac{t}{\color{blue}{\mathsf{log1p}\left(\left(\mathsf{neg}\left(y\right)\right) + y \cdot e^{z}\right)}}} \]
      11. +-commutativeN/A

        \[\leadsto x - \frac{1}{\frac{t}{\mathsf{log1p}\left(\color{blue}{y \cdot e^{z} + \left(\mathsf{neg}\left(y\right)\right)}\right)}} \]
      12. lift-*.f64N/A

        \[\leadsto x - \frac{1}{\frac{t}{\mathsf{log1p}\left(\color{blue}{y \cdot e^{z}} + \left(\mathsf{neg}\left(y\right)\right)\right)}} \]
      13. *-commutativeN/A

        \[\leadsto x - \frac{1}{\frac{t}{\mathsf{log1p}\left(\color{blue}{e^{z} \cdot y} + \left(\mathsf{neg}\left(y\right)\right)\right)}} \]
      14. lower-fma.f64N/A

        \[\leadsto x - \frac{1}{\frac{t}{\mathsf{log1p}\left(\color{blue}{\mathsf{fma}\left(e^{z}, y, \mathsf{neg}\left(y\right)\right)}\right)}} \]
      15. lower-neg.f6493.0

        \[\leadsto x - \frac{1}{\frac{t}{\mathsf{log1p}\left(\mathsf{fma}\left(e^{z}, y, \color{blue}{-y}\right)\right)}} \]
    4. Applied rewrites93.0%

      \[\leadsto x - \color{blue}{\frac{1}{\frac{t}{\mathsf{log1p}\left(\mathsf{fma}\left(e^{z}, y, -y\right)\right)}}} \]
    5. Taylor expanded in y around 0

      \[\leadsto x - \frac{1}{\color{blue}{\frac{\frac{1}{2} \cdot \left(t \cdot y\right) + \frac{t}{e^{z} - 1}}{y}}} \]
    6. Step-by-step derivation
      1. lower-/.f64N/A

        \[\leadsto x - \frac{1}{\color{blue}{\frac{\frac{1}{2} \cdot \left(t \cdot y\right) + \frac{t}{e^{z} - 1}}{y}}} \]
      2. *-commutativeN/A

        \[\leadsto x - \frac{1}{\frac{\color{blue}{\left(t \cdot y\right) \cdot \frac{1}{2}} + \frac{t}{e^{z} - 1}}{y}} \]
      3. lower-fma.f64N/A

        \[\leadsto x - \frac{1}{\frac{\color{blue}{\mathsf{fma}\left(t \cdot y, \frac{1}{2}, \frac{t}{e^{z} - 1}\right)}}{y}} \]
      4. lower-*.f64N/A

        \[\leadsto x - \frac{1}{\frac{\mathsf{fma}\left(\color{blue}{t \cdot y}, \frac{1}{2}, \frac{t}{e^{z} - 1}\right)}{y}} \]
      5. lower-/.f64N/A

        \[\leadsto x - \frac{1}{\frac{\mathsf{fma}\left(t \cdot y, \frac{1}{2}, \color{blue}{\frac{t}{e^{z} - 1}}\right)}{y}} \]
      6. lower-expm1.f6499.9

        \[\leadsto x - \frac{1}{\frac{\mathsf{fma}\left(t \cdot y, 0.5, \frac{t}{\color{blue}{\mathsf{expm1}\left(z\right)}}\right)}{y}} \]
    7. Applied rewrites99.9%

      \[\leadsto x - \frac{1}{\color{blue}{\frac{\mathsf{fma}\left(t \cdot y, 0.5, \frac{t}{\mathsf{expm1}\left(z\right)}\right)}{y}}} \]

    if 2 < (+.f64 (-.f64 #s(literal 1 binary64) y) (*.f64 y (exp.f64 z)))

    1. Initial program 94.0%

      \[x - \frac{\log \left(\left(1 - y\right) + y \cdot e^{z}\right)}{t} \]
    2. Add Preprocessing
  3. Recombined 3 regimes into one program.
  4. Final simplification99.2%

    \[\leadsto \begin{array}{l} \mathbf{if}\;e^{z} \cdot y + \left(1 - y\right) \leq 0:\\ \;\;\;\;x - \frac{1}{\frac{t}{\mathsf{log1p}\left(y \cdot z\right)}}\\ \mathbf{elif}\;e^{z} \cdot y + \left(1 - y\right) \leq 2:\\ \;\;\;\;x - \frac{1}{\frac{\mathsf{fma}\left(y \cdot t, 0.5, \frac{t}{\mathsf{expm1}\left(z\right)}\right)}{y}}\\ \mathbf{else}:\\ \;\;\;\;x - \frac{\log \left(e^{z} \cdot y + \left(1 - y\right)\right)}{t}\\ \end{array} \]
  5. Add Preprocessing

Alternative 2: 92.2% accurate, 0.4× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_1 := x - \frac{1}{\frac{t}{\mathsf{log1p}\left(y \cdot z\right)}}\\ t_2 := \frac{\log \left(e^{z} \cdot y + \left(1 - y\right)\right)}{t}\\ \mathbf{if}\;t\_2 \leq -2 \cdot 10^{-159}:\\ \;\;\;\;t\_1\\ \mathbf{elif}\;t\_2 \leq 2 \cdot 10^{-284}:\\ \;\;\;\;x - \frac{\mathsf{expm1}\left(z\right)}{t} \cdot y\\ \mathbf{else}:\\ \;\;\;\;t\_1\\ \end{array} \end{array} \]
(FPCore (x y z t)
 :precision binary64
 (let* ((t_1 (- x (/ 1.0 (/ t (log1p (* y z))))))
        (t_2 (/ (log (+ (* (exp z) y) (- 1.0 y))) t)))
   (if (<= t_2 -2e-159)
     t_1
     (if (<= t_2 2e-284) (- x (* (/ (expm1 z) t) y)) t_1))))
double code(double x, double y, double z, double t) {
	double t_1 = x - (1.0 / (t / log1p((y * z))));
	double t_2 = log(((exp(z) * y) + (1.0 - y))) / t;
	double tmp;
	if (t_2 <= -2e-159) {
		tmp = t_1;
	} else if (t_2 <= 2e-284) {
		tmp = x - ((expm1(z) / t) * y);
	} else {
		tmp = t_1;
	}
	return tmp;
}
public static double code(double x, double y, double z, double t) {
	double t_1 = x - (1.0 / (t / Math.log1p((y * z))));
	double t_2 = Math.log(((Math.exp(z) * y) + (1.0 - y))) / t;
	double tmp;
	if (t_2 <= -2e-159) {
		tmp = t_1;
	} else if (t_2 <= 2e-284) {
		tmp = x - ((Math.expm1(z) / t) * y);
	} else {
		tmp = t_1;
	}
	return tmp;
}
def code(x, y, z, t):
	t_1 = x - (1.0 / (t / math.log1p((y * z))))
	t_2 = math.log(((math.exp(z) * y) + (1.0 - y))) / t
	tmp = 0
	if t_2 <= -2e-159:
		tmp = t_1
	elif t_2 <= 2e-284:
		tmp = x - ((math.expm1(z) / t) * y)
	else:
		tmp = t_1
	return tmp
function code(x, y, z, t)
	t_1 = Float64(x - Float64(1.0 / Float64(t / log1p(Float64(y * z)))))
	t_2 = Float64(log(Float64(Float64(exp(z) * y) + Float64(1.0 - y))) / t)
	tmp = 0.0
	if (t_2 <= -2e-159)
		tmp = t_1;
	elseif (t_2 <= 2e-284)
		tmp = Float64(x - Float64(Float64(expm1(z) / t) * y));
	else
		tmp = t_1;
	end
	return tmp
end
code[x_, y_, z_, t_] := Block[{t$95$1 = N[(x - N[(1.0 / N[(t / N[Log[1 + N[(y * z), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]}, Block[{t$95$2 = N[(N[Log[N[(N[(N[Exp[z], $MachinePrecision] * y), $MachinePrecision] + N[(1.0 - y), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] / t), $MachinePrecision]}, If[LessEqual[t$95$2, -2e-159], t$95$1, If[LessEqual[t$95$2, 2e-284], N[(x - N[(N[(N[(Exp[z] - 1), $MachinePrecision] / t), $MachinePrecision] * y), $MachinePrecision]), $MachinePrecision], t$95$1]]]]
\begin{array}{l}

\\
\begin{array}{l}
t_1 := x - \frac{1}{\frac{t}{\mathsf{log1p}\left(y \cdot z\right)}}\\
t_2 := \frac{\log \left(e^{z} \cdot y + \left(1 - y\right)\right)}{t}\\
\mathbf{if}\;t\_2 \leq -2 \cdot 10^{-159}:\\
\;\;\;\;t\_1\\

\mathbf{elif}\;t\_2 \leq 2 \cdot 10^{-284}:\\
\;\;\;\;x - \frac{\mathsf{expm1}\left(z\right)}{t} \cdot y\\

\mathbf{else}:\\
\;\;\;\;t\_1\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (/.f64 (log.f64 (+.f64 (-.f64 #s(literal 1 binary64) y) (*.f64 y (exp.f64 z)))) t) < -1.99999999999999998e-159 or 2.00000000000000007e-284 < (/.f64 (log.f64 (+.f64 (-.f64 #s(literal 1 binary64) y) (*.f64 y (exp.f64 z)))) t)

    1. Initial program 25.9%

      \[x - \frac{\log \left(\left(1 - y\right) + y \cdot e^{z}\right)}{t} \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. lift-/.f64N/A

        \[\leadsto x - \color{blue}{\frac{\log \left(\left(1 - y\right) + y \cdot e^{z}\right)}{t}} \]
      2. clear-numN/A

        \[\leadsto x - \color{blue}{\frac{1}{\frac{t}{\log \left(\left(1 - y\right) + y \cdot e^{z}\right)}}} \]
      3. lower-/.f64N/A

        \[\leadsto x - \color{blue}{\frac{1}{\frac{t}{\log \left(\left(1 - y\right) + y \cdot e^{z}\right)}}} \]
      4. lower-/.f6425.9

        \[\leadsto x - \frac{1}{\color{blue}{\frac{t}{\log \left(\left(1 - y\right) + y \cdot e^{z}\right)}}} \]
      5. lift-log.f64N/A

        \[\leadsto x - \frac{1}{\frac{t}{\color{blue}{\log \left(\left(1 - y\right) + y \cdot e^{z}\right)}}} \]
      6. lift-+.f64N/A

        \[\leadsto x - \frac{1}{\frac{t}{\log \color{blue}{\left(\left(1 - y\right) + y \cdot e^{z}\right)}}} \]
      7. lift--.f64N/A

        \[\leadsto x - \frac{1}{\frac{t}{\log \left(\color{blue}{\left(1 - y\right)} + y \cdot e^{z}\right)}} \]
      8. sub-negN/A

        \[\leadsto x - \frac{1}{\frac{t}{\log \left(\color{blue}{\left(1 + \left(\mathsf{neg}\left(y\right)\right)\right)} + y \cdot e^{z}\right)}} \]
      9. associate-+l+N/A

        \[\leadsto x - \frac{1}{\frac{t}{\log \color{blue}{\left(1 + \left(\left(\mathsf{neg}\left(y\right)\right) + y \cdot e^{z}\right)\right)}}} \]
      10. lower-log1p.f64N/A

        \[\leadsto x - \frac{1}{\frac{t}{\color{blue}{\mathsf{log1p}\left(\left(\mathsf{neg}\left(y\right)\right) + y \cdot e^{z}\right)}}} \]
      11. +-commutativeN/A

        \[\leadsto x - \frac{1}{\frac{t}{\mathsf{log1p}\left(\color{blue}{y \cdot e^{z} + \left(\mathsf{neg}\left(y\right)\right)}\right)}} \]
      12. lift-*.f64N/A

        \[\leadsto x - \frac{1}{\frac{t}{\mathsf{log1p}\left(\color{blue}{y \cdot e^{z}} + \left(\mathsf{neg}\left(y\right)\right)\right)}} \]
      13. *-commutativeN/A

        \[\leadsto x - \frac{1}{\frac{t}{\mathsf{log1p}\left(\color{blue}{e^{z} \cdot y} + \left(\mathsf{neg}\left(y\right)\right)\right)}} \]
      14. lower-fma.f64N/A

        \[\leadsto x - \frac{1}{\frac{t}{\mathsf{log1p}\left(\color{blue}{\mathsf{fma}\left(e^{z}, y, \mathsf{neg}\left(y\right)\right)}\right)}} \]
      15. lower-neg.f6467.8

        \[\leadsto x - \frac{1}{\frac{t}{\mathsf{log1p}\left(\mathsf{fma}\left(e^{z}, y, \color{blue}{-y}\right)\right)}} \]
    4. Applied rewrites67.8%

      \[\leadsto x - \color{blue}{\frac{1}{\frac{t}{\mathsf{log1p}\left(\mathsf{fma}\left(e^{z}, y, -y\right)\right)}}} \]
    5. Taylor expanded in z around 0

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

        \[\leadsto x - \frac{1}{\frac{t}{\mathsf{log1p}\left(\color{blue}{z \cdot y}\right)}} \]
      2. lower-*.f6488.3

        \[\leadsto x - \frac{1}{\frac{t}{\mathsf{log1p}\left(\color{blue}{z \cdot y}\right)}} \]
    7. Applied rewrites88.3%

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

    if -1.99999999999999998e-159 < (/.f64 (log.f64 (+.f64 (-.f64 #s(literal 1 binary64) y) (*.f64 y (exp.f64 z)))) t) < 2.00000000000000007e-284

    1. Initial program 82.2%

      \[x - \frac{\log \left(\left(1 - y\right) + y \cdot e^{z}\right)}{t} \]
    2. Add Preprocessing
    3. Taylor expanded in y around 0

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

        \[\leadsto x - \color{blue}{y \cdot \frac{e^{z} - 1}{t}} \]
      2. div-subN/A

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

        \[\leadsto x - \color{blue}{\left(\frac{e^{z}}{t} - \frac{1}{t}\right) \cdot y} \]
      4. lower-*.f64N/A

        \[\leadsto x - \color{blue}{\left(\frac{e^{z}}{t} - \frac{1}{t}\right) \cdot y} \]
      5. div-subN/A

        \[\leadsto x - \color{blue}{\frac{e^{z} - 1}{t}} \cdot y \]
      6. lower-/.f64N/A

        \[\leadsto x - \color{blue}{\frac{e^{z} - 1}{t}} \cdot y \]
      7. lower-expm1.f6499.9

        \[\leadsto x - \frac{\color{blue}{\mathsf{expm1}\left(z\right)}}{t} \cdot y \]
    5. Applied rewrites99.9%

      \[\leadsto x - \color{blue}{\frac{\mathsf{expm1}\left(z\right)}{t} \cdot y} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification96.2%

    \[\leadsto \begin{array}{l} \mathbf{if}\;\frac{\log \left(e^{z} \cdot y + \left(1 - y\right)\right)}{t} \leq -2 \cdot 10^{-159}:\\ \;\;\;\;x - \frac{1}{\frac{t}{\mathsf{log1p}\left(y \cdot z\right)}}\\ \mathbf{elif}\;\frac{\log \left(e^{z} \cdot y + \left(1 - y\right)\right)}{t} \leq 2 \cdot 10^{-284}:\\ \;\;\;\;x - \frac{\mathsf{expm1}\left(z\right)}{t} \cdot y\\ \mathbf{else}:\\ \;\;\;\;x - \frac{1}{\frac{t}{\mathsf{log1p}\left(y \cdot z\right)}}\\ \end{array} \]
  5. Add Preprocessing

Alternative 3: 94.7% accurate, 0.9× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;e^{z} \cdot y + \left(1 - y\right) \leq 0:\\ \;\;\;\;x - \frac{1}{\frac{t}{\mathsf{log1p}\left(y \cdot z\right)}}\\ \mathbf{else}:\\ \;\;\;\;x - \frac{1}{\frac{\mathsf{fma}\left(y \cdot t, 0.5, \frac{t}{\mathsf{expm1}\left(z\right)}\right)}{y}}\\ \end{array} \end{array} \]
(FPCore (x y z t)
 :precision binary64
 (if (<= (+ (* (exp z) y) (- 1.0 y)) 0.0)
   (- x (/ 1.0 (/ t (log1p (* y z)))))
   (- x (/ 1.0 (/ (fma (* y t) 0.5 (/ t (expm1 z))) y)))))
double code(double x, double y, double z, double t) {
	double tmp;
	if (((exp(z) * y) + (1.0 - y)) <= 0.0) {
		tmp = x - (1.0 / (t / log1p((y * z))));
	} else {
		tmp = x - (1.0 / (fma((y * t), 0.5, (t / expm1(z))) / y));
	}
	return tmp;
}
function code(x, y, z, t)
	tmp = 0.0
	if (Float64(Float64(exp(z) * y) + Float64(1.0 - y)) <= 0.0)
		tmp = Float64(x - Float64(1.0 / Float64(t / log1p(Float64(y * z)))));
	else
		tmp = Float64(x - Float64(1.0 / Float64(fma(Float64(y * t), 0.5, Float64(t / expm1(z))) / y)));
	end
	return tmp
end
code[x_, y_, z_, t_] := If[LessEqual[N[(N[(N[Exp[z], $MachinePrecision] * y), $MachinePrecision] + N[(1.0 - y), $MachinePrecision]), $MachinePrecision], 0.0], N[(x - N[(1.0 / N[(t / N[Log[1 + N[(y * z), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(x - N[(1.0 / N[(N[(N[(y * t), $MachinePrecision] * 0.5 + N[(t / N[(Exp[z] - 1), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / y), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;e^{z} \cdot y + \left(1 - y\right) \leq 0:\\
\;\;\;\;x - \frac{1}{\frac{t}{\mathsf{log1p}\left(y \cdot z\right)}}\\

\mathbf{else}:\\
\;\;\;\;x - \frac{1}{\frac{\mathsf{fma}\left(y \cdot t, 0.5, \frac{t}{\mathsf{expm1}\left(z\right)}\right)}{y}}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (+.f64 (-.f64 #s(literal 1 binary64) y) (*.f64 y (exp.f64 z))) < 0.0

    1. Initial program 1.9%

      \[x - \frac{\log \left(\left(1 - y\right) + y \cdot e^{z}\right)}{t} \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. lift-/.f64N/A

        \[\leadsto x - \color{blue}{\frac{\log \left(\left(1 - y\right) + y \cdot e^{z}\right)}{t}} \]
      2. clear-numN/A

        \[\leadsto x - \color{blue}{\frac{1}{\frac{t}{\log \left(\left(1 - y\right) + y \cdot e^{z}\right)}}} \]
      3. lower-/.f64N/A

        \[\leadsto x - \color{blue}{\frac{1}{\frac{t}{\log \left(\left(1 - y\right) + y \cdot e^{z}\right)}}} \]
      4. lower-/.f641.9

        \[\leadsto x - \frac{1}{\color{blue}{\frac{t}{\log \left(\left(1 - y\right) + y \cdot e^{z}\right)}}} \]
      5. lift-log.f64N/A

        \[\leadsto x - \frac{1}{\frac{t}{\color{blue}{\log \left(\left(1 - y\right) + y \cdot e^{z}\right)}}} \]
      6. lift-+.f64N/A

        \[\leadsto x - \frac{1}{\frac{t}{\log \color{blue}{\left(\left(1 - y\right) + y \cdot e^{z}\right)}}} \]
      7. lift--.f64N/A

        \[\leadsto x - \frac{1}{\frac{t}{\log \left(\color{blue}{\left(1 - y\right)} + y \cdot e^{z}\right)}} \]
      8. sub-negN/A

        \[\leadsto x - \frac{1}{\frac{t}{\log \left(\color{blue}{\left(1 + \left(\mathsf{neg}\left(y\right)\right)\right)} + y \cdot e^{z}\right)}} \]
      9. associate-+l+N/A

        \[\leadsto x - \frac{1}{\frac{t}{\log \color{blue}{\left(1 + \left(\left(\mathsf{neg}\left(y\right)\right) + y \cdot e^{z}\right)\right)}}} \]
      10. lower-log1p.f64N/A

        \[\leadsto x - \frac{1}{\frac{t}{\color{blue}{\mathsf{log1p}\left(\left(\mathsf{neg}\left(y\right)\right) + y \cdot e^{z}\right)}}} \]
      11. +-commutativeN/A

        \[\leadsto x - \frac{1}{\frac{t}{\mathsf{log1p}\left(\color{blue}{y \cdot e^{z} + \left(\mathsf{neg}\left(y\right)\right)}\right)}} \]
      12. lift-*.f64N/A

        \[\leadsto x - \frac{1}{\frac{t}{\mathsf{log1p}\left(\color{blue}{y \cdot e^{z}} + \left(\mathsf{neg}\left(y\right)\right)\right)}} \]
      13. *-commutativeN/A

        \[\leadsto x - \frac{1}{\frac{t}{\mathsf{log1p}\left(\color{blue}{e^{z} \cdot y} + \left(\mathsf{neg}\left(y\right)\right)\right)}} \]
      14. lower-fma.f64N/A

        \[\leadsto x - \frac{1}{\frac{t}{\mathsf{log1p}\left(\color{blue}{\mathsf{fma}\left(e^{z}, y, \mathsf{neg}\left(y\right)\right)}\right)}} \]
      15. lower-neg.f6458.3

        \[\leadsto x - \frac{1}{\frac{t}{\mathsf{log1p}\left(\mathsf{fma}\left(e^{z}, y, \color{blue}{-y}\right)\right)}} \]
    4. Applied rewrites58.3%

      \[\leadsto x - \color{blue}{\frac{1}{\frac{t}{\mathsf{log1p}\left(\mathsf{fma}\left(e^{z}, y, -y\right)\right)}}} \]
    5. Taylor expanded in z around 0

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

        \[\leadsto x - \frac{1}{\frac{t}{\mathsf{log1p}\left(\color{blue}{z \cdot y}\right)}} \]
      2. lower-*.f6499.8

        \[\leadsto x - \frac{1}{\frac{t}{\mathsf{log1p}\left(\color{blue}{z \cdot y}\right)}} \]
    7. Applied rewrites99.8%

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

    if 0.0 < (+.f64 (-.f64 #s(literal 1 binary64) y) (*.f64 y (exp.f64 z)))

    1. Initial program 82.9%

      \[x - \frac{\log \left(\left(1 - y\right) + y \cdot e^{z}\right)}{t} \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. lift-/.f64N/A

        \[\leadsto x - \color{blue}{\frac{\log \left(\left(1 - y\right) + y \cdot e^{z}\right)}{t}} \]
      2. clear-numN/A

        \[\leadsto x - \color{blue}{\frac{1}{\frac{t}{\log \left(\left(1 - y\right) + y \cdot e^{z}\right)}}} \]
      3. lower-/.f64N/A

        \[\leadsto x - \color{blue}{\frac{1}{\frac{t}{\log \left(\left(1 - y\right) + y \cdot e^{z}\right)}}} \]
      4. lower-/.f6482.9

        \[\leadsto x - \frac{1}{\color{blue}{\frac{t}{\log \left(\left(1 - y\right) + y \cdot e^{z}\right)}}} \]
      5. lift-log.f64N/A

        \[\leadsto x - \frac{1}{\frac{t}{\color{blue}{\log \left(\left(1 - y\right) + y \cdot e^{z}\right)}}} \]
      6. lift-+.f64N/A

        \[\leadsto x - \frac{1}{\frac{t}{\log \color{blue}{\left(\left(1 - y\right) + y \cdot e^{z}\right)}}} \]
      7. lift--.f64N/A

        \[\leadsto x - \frac{1}{\frac{t}{\log \left(\color{blue}{\left(1 - y\right)} + y \cdot e^{z}\right)}} \]
      8. sub-negN/A

        \[\leadsto x - \frac{1}{\frac{t}{\log \left(\color{blue}{\left(1 + \left(\mathsf{neg}\left(y\right)\right)\right)} + y \cdot e^{z}\right)}} \]
      9. associate-+l+N/A

        \[\leadsto x - \frac{1}{\frac{t}{\log \color{blue}{\left(1 + \left(\left(\mathsf{neg}\left(y\right)\right) + y \cdot e^{z}\right)\right)}}} \]
      10. lower-log1p.f64N/A

        \[\leadsto x - \frac{1}{\frac{t}{\color{blue}{\mathsf{log1p}\left(\left(\mathsf{neg}\left(y\right)\right) + y \cdot e^{z}\right)}}} \]
      11. +-commutativeN/A

        \[\leadsto x - \frac{1}{\frac{t}{\mathsf{log1p}\left(\color{blue}{y \cdot e^{z} + \left(\mathsf{neg}\left(y\right)\right)}\right)}} \]
      12. lift-*.f64N/A

        \[\leadsto x - \frac{1}{\frac{t}{\mathsf{log1p}\left(\color{blue}{y \cdot e^{z}} + \left(\mathsf{neg}\left(y\right)\right)\right)}} \]
      13. *-commutativeN/A

        \[\leadsto x - \frac{1}{\frac{t}{\mathsf{log1p}\left(\color{blue}{e^{z} \cdot y} + \left(\mathsf{neg}\left(y\right)\right)\right)}} \]
      14. lower-fma.f64N/A

        \[\leadsto x - \frac{1}{\frac{t}{\mathsf{log1p}\left(\color{blue}{\mathsf{fma}\left(e^{z}, y, \mathsf{neg}\left(y\right)\right)}\right)}} \]
      15. lower-neg.f6493.1

        \[\leadsto x - \frac{1}{\frac{t}{\mathsf{log1p}\left(\mathsf{fma}\left(e^{z}, y, \color{blue}{-y}\right)\right)}} \]
    4. Applied rewrites93.1%

      \[\leadsto x - \color{blue}{\frac{1}{\frac{t}{\mathsf{log1p}\left(\mathsf{fma}\left(e^{z}, y, -y\right)\right)}}} \]
    5. Taylor expanded in y around 0

      \[\leadsto x - \frac{1}{\color{blue}{\frac{\frac{1}{2} \cdot \left(t \cdot y\right) + \frac{t}{e^{z} - 1}}{y}}} \]
    6. Step-by-step derivation
      1. lower-/.f64N/A

        \[\leadsto x - \frac{1}{\color{blue}{\frac{\frac{1}{2} \cdot \left(t \cdot y\right) + \frac{t}{e^{z} - 1}}{y}}} \]
      2. *-commutativeN/A

        \[\leadsto x - \frac{1}{\frac{\color{blue}{\left(t \cdot y\right) \cdot \frac{1}{2}} + \frac{t}{e^{z} - 1}}{y}} \]
      3. lower-fma.f64N/A

        \[\leadsto x - \frac{1}{\frac{\color{blue}{\mathsf{fma}\left(t \cdot y, \frac{1}{2}, \frac{t}{e^{z} - 1}\right)}}{y}} \]
      4. lower-*.f64N/A

        \[\leadsto x - \frac{1}{\frac{\mathsf{fma}\left(\color{blue}{t \cdot y}, \frac{1}{2}, \frac{t}{e^{z} - 1}\right)}{y}} \]
      5. lower-/.f64N/A

        \[\leadsto x - \frac{1}{\frac{\mathsf{fma}\left(t \cdot y, \frac{1}{2}, \color{blue}{\frac{t}{e^{z} - 1}}\right)}{y}} \]
      6. lower-expm1.f6494.3

        \[\leadsto x - \frac{1}{\frac{\mathsf{fma}\left(t \cdot y, 0.5, \frac{t}{\color{blue}{\mathsf{expm1}\left(z\right)}}\right)}{y}} \]
    7. Applied rewrites94.3%

      \[\leadsto x - \frac{1}{\color{blue}{\frac{\mathsf{fma}\left(t \cdot y, 0.5, \frac{t}{\mathsf{expm1}\left(z\right)}\right)}{y}}} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification95.6%

    \[\leadsto \begin{array}{l} \mathbf{if}\;e^{z} \cdot y + \left(1 - y\right) \leq 0:\\ \;\;\;\;x - \frac{1}{\frac{t}{\mathsf{log1p}\left(y \cdot z\right)}}\\ \mathbf{else}:\\ \;\;\;\;x - \frac{1}{\frac{\mathsf{fma}\left(y \cdot t, 0.5, \frac{t}{\mathsf{expm1}\left(z\right)}\right)}{y}}\\ \end{array} \]
  5. Add Preprocessing

Alternative 4: 98.4% accurate, 1.0× speedup?

\[\begin{array}{l} \\ x - \frac{1}{\frac{t}{\mathsf{log1p}\left(y \cdot \mathsf{expm1}\left(z\right)\right)}} \end{array} \]
(FPCore (x y z t)
 :precision binary64
 (- x (/ 1.0 (/ t (log1p (* y (expm1 z)))))))
double code(double x, double y, double z, double t) {
	return x - (1.0 / (t / log1p((y * expm1(z)))));
}
public static double code(double x, double y, double z, double t) {
	return x - (1.0 / (t / Math.log1p((y * Math.expm1(z)))));
}
def code(x, y, z, t):
	return x - (1.0 / (t / math.log1p((y * math.expm1(z)))))
function code(x, y, z, t)
	return Float64(x - Float64(1.0 / Float64(t / log1p(Float64(y * expm1(z))))))
end
code[x_, y_, z_, t_] := N[(x - N[(1.0 / N[(t / N[Log[1 + N[(y * N[(Exp[z] - 1), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
x - \frac{1}{\frac{t}{\mathsf{log1p}\left(y \cdot \mathsf{expm1}\left(z\right)\right)}}
\end{array}
Derivation
  1. Initial program 63.9%

    \[x - \frac{\log \left(\left(1 - y\right) + y \cdot e^{z}\right)}{t} \]
  2. Add Preprocessing
  3. Step-by-step derivation
    1. lift-/.f64N/A

      \[\leadsto x - \color{blue}{\frac{\log \left(\left(1 - y\right) + y \cdot e^{z}\right)}{t}} \]
    2. clear-numN/A

      \[\leadsto x - \color{blue}{\frac{1}{\frac{t}{\log \left(\left(1 - y\right) + y \cdot e^{z}\right)}}} \]
    3. lower-/.f64N/A

      \[\leadsto x - \color{blue}{\frac{1}{\frac{t}{\log \left(\left(1 - y\right) + y \cdot e^{z}\right)}}} \]
    4. lower-/.f6463.9

      \[\leadsto x - \frac{1}{\color{blue}{\frac{t}{\log \left(\left(1 - y\right) + y \cdot e^{z}\right)}}} \]
    5. lift-log.f64N/A

      \[\leadsto x - \frac{1}{\frac{t}{\color{blue}{\log \left(\left(1 - y\right) + y \cdot e^{z}\right)}}} \]
    6. lift-+.f64N/A

      \[\leadsto x - \frac{1}{\frac{t}{\log \color{blue}{\left(\left(1 - y\right) + y \cdot e^{z}\right)}}} \]
    7. lift--.f64N/A

      \[\leadsto x - \frac{1}{\frac{t}{\log \left(\color{blue}{\left(1 - y\right)} + y \cdot e^{z}\right)}} \]
    8. sub-negN/A

      \[\leadsto x - \frac{1}{\frac{t}{\log \left(\color{blue}{\left(1 + \left(\mathsf{neg}\left(y\right)\right)\right)} + y \cdot e^{z}\right)}} \]
    9. associate-+l+N/A

      \[\leadsto x - \frac{1}{\frac{t}{\log \color{blue}{\left(1 + \left(\left(\mathsf{neg}\left(y\right)\right) + y \cdot e^{z}\right)\right)}}} \]
    10. lower-log1p.f64N/A

      \[\leadsto x - \frac{1}{\frac{t}{\color{blue}{\mathsf{log1p}\left(\left(\mathsf{neg}\left(y\right)\right) + y \cdot e^{z}\right)}}} \]
    11. +-commutativeN/A

      \[\leadsto x - \frac{1}{\frac{t}{\mathsf{log1p}\left(\color{blue}{y \cdot e^{z} + \left(\mathsf{neg}\left(y\right)\right)}\right)}} \]
    12. lift-*.f64N/A

      \[\leadsto x - \frac{1}{\frac{t}{\mathsf{log1p}\left(\color{blue}{y \cdot e^{z}} + \left(\mathsf{neg}\left(y\right)\right)\right)}} \]
    13. *-commutativeN/A

      \[\leadsto x - \frac{1}{\frac{t}{\mathsf{log1p}\left(\color{blue}{e^{z} \cdot y} + \left(\mathsf{neg}\left(y\right)\right)\right)}} \]
    14. lower-fma.f64N/A

      \[\leadsto x - \frac{1}{\frac{t}{\mathsf{log1p}\left(\color{blue}{\mathsf{fma}\left(e^{z}, y, \mathsf{neg}\left(y\right)\right)}\right)}} \]
    15. lower-neg.f6484.9

      \[\leadsto x - \frac{1}{\frac{t}{\mathsf{log1p}\left(\mathsf{fma}\left(e^{z}, y, \color{blue}{-y}\right)\right)}} \]
  4. Applied rewrites84.9%

    \[\leadsto x - \color{blue}{\frac{1}{\frac{t}{\mathsf{log1p}\left(\mathsf{fma}\left(e^{z}, y, -y\right)\right)}}} \]
  5. Step-by-step derivation
    1. lift-exp.f64N/A

      \[\leadsto x - \frac{1}{\frac{t}{\mathsf{log1p}\left(\mathsf{fma}\left(\color{blue}{e^{z}}, y, -y\right)\right)}} \]
    2. lift-fma.f64N/A

      \[\leadsto x - \frac{1}{\frac{t}{\mathsf{log1p}\left(\color{blue}{e^{z} \cdot y + \left(-y\right)}\right)}} \]
    3. lift-neg.f64N/A

      \[\leadsto x - \frac{1}{\frac{t}{\mathsf{log1p}\left(e^{z} \cdot y + \color{blue}{\left(\mathsf{neg}\left(y\right)\right)}\right)}} \]
    4. neg-mul-1N/A

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

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

      \[\leadsto x - \frac{1}{\frac{t}{\mathsf{log1p}\left(y \cdot \left(e^{z} + \color{blue}{\left(\mathsf{neg}\left(1\right)\right)}\right)\right)}} \]
    7. sub-negN/A

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

      \[\leadsto x - \frac{1}{\frac{t}{\mathsf{log1p}\left(\color{blue}{\left(e^{z} - 1\right) \cdot y}\right)}} \]
    9. lower-*.f64N/A

      \[\leadsto x - \frac{1}{\frac{t}{\mathsf{log1p}\left(\color{blue}{\left(e^{z} - 1\right) \cdot y}\right)}} \]
    10. lower-expm1.f6498.5

      \[\leadsto x - \frac{1}{\frac{t}{\mathsf{log1p}\left(\color{blue}{\mathsf{expm1}\left(z\right)} \cdot y\right)}} \]
  6. Applied rewrites98.5%

    \[\leadsto x - \color{blue}{\frac{1}{\frac{t}{\mathsf{log1p}\left(\mathsf{expm1}\left(z\right) \cdot y\right)}}} \]
  7. Final simplification98.5%

    \[\leadsto x - \frac{1}{\frac{t}{\mathsf{log1p}\left(y \cdot \mathsf{expm1}\left(z\right)\right)}} \]
  8. Add Preprocessing

Alternative 5: 86.4% accurate, 1.8× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;y \leq -6.4 \cdot 10^{+75}:\\ \;\;\;\;x - \frac{\log \left(\mathsf{fma}\left(z, y, 1\right)\right)}{t}\\ \mathbf{else}:\\ \;\;\;\;x - \frac{\mathsf{expm1}\left(z\right)}{t} \cdot y\\ \end{array} \end{array} \]
(FPCore (x y z t)
 :precision binary64
 (if (<= y -6.4e+75)
   (- x (/ (log (fma z y 1.0)) t))
   (- x (* (/ (expm1 z) t) y))))
double code(double x, double y, double z, double t) {
	double tmp;
	if (y <= -6.4e+75) {
		tmp = x - (log(fma(z, y, 1.0)) / t);
	} else {
		tmp = x - ((expm1(z) / t) * y);
	}
	return tmp;
}
function code(x, y, z, t)
	tmp = 0.0
	if (y <= -6.4e+75)
		tmp = Float64(x - Float64(log(fma(z, y, 1.0)) / t));
	else
		tmp = Float64(x - Float64(Float64(expm1(z) / t) * y));
	end
	return tmp
end
code[x_, y_, z_, t_] := If[LessEqual[y, -6.4e+75], N[(x - N[(N[Log[N[(z * y + 1.0), $MachinePrecision]], $MachinePrecision] / t), $MachinePrecision]), $MachinePrecision], N[(x - N[(N[(N[(Exp[z] - 1), $MachinePrecision] / t), $MachinePrecision] * y), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;y \leq -6.4 \cdot 10^{+75}:\\
\;\;\;\;x - \frac{\log \left(\mathsf{fma}\left(z, y, 1\right)\right)}{t}\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if y < -6.39999999999999969e75

    1. Initial program 48.9%

      \[x - \frac{\log \left(\left(1 - y\right) + y \cdot e^{z}\right)}{t} \]
    2. Add Preprocessing
    3. Taylor expanded in z around 0

      \[\leadsto x - \frac{\log \color{blue}{\left(1 + y \cdot z\right)}}{t} \]
    4. Step-by-step derivation
      1. +-commutativeN/A

        \[\leadsto x - \frac{\log \color{blue}{\left(y \cdot z + 1\right)}}{t} \]
      2. *-commutativeN/A

        \[\leadsto x - \frac{\log \left(\color{blue}{z \cdot y} + 1\right)}{t} \]
      3. lower-fma.f6469.4

        \[\leadsto x - \frac{\log \color{blue}{\left(\mathsf{fma}\left(z, y, 1\right)\right)}}{t} \]
    5. Applied rewrites69.4%

      \[\leadsto x - \frac{\log \color{blue}{\left(\mathsf{fma}\left(z, y, 1\right)\right)}}{t} \]

    if -6.39999999999999969e75 < y

    1. Initial program 66.8%

      \[x - \frac{\log \left(\left(1 - y\right) + y \cdot e^{z}\right)}{t} \]
    2. Add Preprocessing
    3. Taylor expanded in y around 0

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

        \[\leadsto x - \color{blue}{y \cdot \frac{e^{z} - 1}{t}} \]
      2. div-subN/A

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

        \[\leadsto x - \color{blue}{\left(\frac{e^{z}}{t} - \frac{1}{t}\right) \cdot y} \]
      4. lower-*.f64N/A

        \[\leadsto x - \color{blue}{\left(\frac{e^{z}}{t} - \frac{1}{t}\right) \cdot y} \]
      5. div-subN/A

        \[\leadsto x - \color{blue}{\frac{e^{z} - 1}{t}} \cdot y \]
      6. lower-/.f64N/A

        \[\leadsto x - \color{blue}{\frac{e^{z} - 1}{t}} \cdot y \]
      7. lower-expm1.f6495.5

        \[\leadsto x - \frac{\color{blue}{\mathsf{expm1}\left(z\right)}}{t} \cdot y \]
    5. Applied rewrites95.5%

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

Alternative 6: 85.9% accurate, 1.9× speedup?

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

\\
x - \frac{\mathsf{expm1}\left(z\right)}{t} \cdot y
\end{array}
Derivation
  1. Initial program 63.9%

    \[x - \frac{\log \left(\left(1 - y\right) + y \cdot e^{z}\right)}{t} \]
  2. Add Preprocessing
  3. Taylor expanded in y around 0

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

      \[\leadsto x - \color{blue}{y \cdot \frac{e^{z} - 1}{t}} \]
    2. div-subN/A

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

      \[\leadsto x - \color{blue}{\left(\frac{e^{z}}{t} - \frac{1}{t}\right) \cdot y} \]
    4. lower-*.f64N/A

      \[\leadsto x - \color{blue}{\left(\frac{e^{z}}{t} - \frac{1}{t}\right) \cdot y} \]
    5. div-subN/A

      \[\leadsto x - \color{blue}{\frac{e^{z} - 1}{t}} \cdot y \]
    6. lower-/.f64N/A

      \[\leadsto x - \color{blue}{\frac{e^{z} - 1}{t}} \cdot y \]
    7. lower-expm1.f6488.4

      \[\leadsto x - \frac{\color{blue}{\mathsf{expm1}\left(z\right)}}{t} \cdot y \]
  5. Applied rewrites88.4%

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

Alternative 7: 83.2% accurate, 2.5× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;z \leq -5.8 \cdot 10^{-118}:\\ \;\;\;\;x - \frac{1}{\frac{\mathsf{fma}\left(\frac{-0.5}{y}, \frac{\left(\left(y - y \cdot y\right) \cdot z\right) \cdot t}{y}, \frac{t}{y}\right)}{z}}\\ \mathbf{else}:\\ \;\;\;\;x - \frac{\frac{z}{t} \cdot \mathsf{fma}\left(z \cdot z, 0.25, -1\right)}{\mathsf{fma}\left(0.5, z, -1\right)} \cdot y\\ \end{array} \end{array} \]
(FPCore (x y z t)
 :precision binary64
 (if (<= z -5.8e-118)
   (- x (/ 1.0 (/ (fma (/ -0.5 y) (/ (* (* (- y (* y y)) z) t) y) (/ t y)) z)))
   (- x (* (/ (* (/ z t) (fma (* z z) 0.25 -1.0)) (fma 0.5 z -1.0)) y))))
double code(double x, double y, double z, double t) {
	double tmp;
	if (z <= -5.8e-118) {
		tmp = x - (1.0 / (fma((-0.5 / y), ((((y - (y * y)) * z) * t) / y), (t / y)) / z));
	} else {
		tmp = x - ((((z / t) * fma((z * z), 0.25, -1.0)) / fma(0.5, z, -1.0)) * y);
	}
	return tmp;
}
function code(x, y, z, t)
	tmp = 0.0
	if (z <= -5.8e-118)
		tmp = Float64(x - Float64(1.0 / Float64(fma(Float64(-0.5 / y), Float64(Float64(Float64(Float64(y - Float64(y * y)) * z) * t) / y), Float64(t / y)) / z)));
	else
		tmp = Float64(x - Float64(Float64(Float64(Float64(z / t) * fma(Float64(z * z), 0.25, -1.0)) / fma(0.5, z, -1.0)) * y));
	end
	return tmp
end
code[x_, y_, z_, t_] := If[LessEqual[z, -5.8e-118], N[(x - N[(1.0 / N[(N[(N[(-0.5 / y), $MachinePrecision] * N[(N[(N[(N[(y - N[(y * y), $MachinePrecision]), $MachinePrecision] * z), $MachinePrecision] * t), $MachinePrecision] / y), $MachinePrecision] + N[(t / y), $MachinePrecision]), $MachinePrecision] / z), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(x - N[(N[(N[(N[(z / t), $MachinePrecision] * N[(N[(z * z), $MachinePrecision] * 0.25 + -1.0), $MachinePrecision]), $MachinePrecision] / N[(0.5 * z + -1.0), $MachinePrecision]), $MachinePrecision] * y), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;z \leq -5.8 \cdot 10^{-118}:\\
\;\;\;\;x - \frac{1}{\frac{\mathsf{fma}\left(\frac{-0.5}{y}, \frac{\left(\left(y - y \cdot y\right) \cdot z\right) \cdot t}{y}, \frac{t}{y}\right)}{z}}\\

\mathbf{else}:\\
\;\;\;\;x - \frac{\frac{z}{t} \cdot \mathsf{fma}\left(z \cdot z, 0.25, -1\right)}{\mathsf{fma}\left(0.5, z, -1\right)} \cdot y\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if z < -5.79999999999999961e-118

    1. Initial program 70.5%

      \[x - \frac{\log \left(\left(1 - y\right) + y \cdot e^{z}\right)}{t} \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. lift-/.f64N/A

        \[\leadsto x - \color{blue}{\frac{\log \left(\left(1 - y\right) + y \cdot e^{z}\right)}{t}} \]
      2. clear-numN/A

        \[\leadsto x - \color{blue}{\frac{1}{\frac{t}{\log \left(\left(1 - y\right) + y \cdot e^{z}\right)}}} \]
      3. lower-/.f64N/A

        \[\leadsto x - \color{blue}{\frac{1}{\frac{t}{\log \left(\left(1 - y\right) + y \cdot e^{z}\right)}}} \]
      4. lower-/.f6470.4

        \[\leadsto x - \frac{1}{\color{blue}{\frac{t}{\log \left(\left(1 - y\right) + y \cdot e^{z}\right)}}} \]
      5. lift-log.f64N/A

        \[\leadsto x - \frac{1}{\frac{t}{\color{blue}{\log \left(\left(1 - y\right) + y \cdot e^{z}\right)}}} \]
      6. lift-+.f64N/A

        \[\leadsto x - \frac{1}{\frac{t}{\log \color{blue}{\left(\left(1 - y\right) + y \cdot e^{z}\right)}}} \]
      7. lift--.f64N/A

        \[\leadsto x - \frac{1}{\frac{t}{\log \left(\color{blue}{\left(1 - y\right)} + y \cdot e^{z}\right)}} \]
      8. sub-negN/A

        \[\leadsto x - \frac{1}{\frac{t}{\log \left(\color{blue}{\left(1 + \left(\mathsf{neg}\left(y\right)\right)\right)} + y \cdot e^{z}\right)}} \]
      9. associate-+l+N/A

        \[\leadsto x - \frac{1}{\frac{t}{\log \color{blue}{\left(1 + \left(\left(\mathsf{neg}\left(y\right)\right) + y \cdot e^{z}\right)\right)}}} \]
      10. lower-log1p.f64N/A

        \[\leadsto x - \frac{1}{\frac{t}{\color{blue}{\mathsf{log1p}\left(\left(\mathsf{neg}\left(y\right)\right) + y \cdot e^{z}\right)}}} \]
      11. +-commutativeN/A

        \[\leadsto x - \frac{1}{\frac{t}{\mathsf{log1p}\left(\color{blue}{y \cdot e^{z} + \left(\mathsf{neg}\left(y\right)\right)}\right)}} \]
      12. lift-*.f64N/A

        \[\leadsto x - \frac{1}{\frac{t}{\mathsf{log1p}\left(\color{blue}{y \cdot e^{z}} + \left(\mathsf{neg}\left(y\right)\right)\right)}} \]
      13. *-commutativeN/A

        \[\leadsto x - \frac{1}{\frac{t}{\mathsf{log1p}\left(\color{blue}{e^{z} \cdot y} + \left(\mathsf{neg}\left(y\right)\right)\right)}} \]
      14. lower-fma.f64N/A

        \[\leadsto x - \frac{1}{\frac{t}{\mathsf{log1p}\left(\color{blue}{\mathsf{fma}\left(e^{z}, y, \mathsf{neg}\left(y\right)\right)}\right)}} \]
      15. lower-neg.f6491.4

        \[\leadsto x - \frac{1}{\frac{t}{\mathsf{log1p}\left(\mathsf{fma}\left(e^{z}, y, \color{blue}{-y}\right)\right)}} \]
    4. Applied rewrites91.4%

      \[\leadsto x - \color{blue}{\frac{1}{\frac{t}{\mathsf{log1p}\left(\mathsf{fma}\left(e^{z}, y, -y\right)\right)}}} \]
    5. Taylor expanded in z around 0

      \[\leadsto x - \frac{1}{\color{blue}{\frac{\frac{-1}{2} \cdot \frac{t \cdot \left(z \cdot \left(y + -1 \cdot {y}^{2}\right)\right)}{{y}^{2}} + \frac{t}{y}}{z}}} \]
    6. Step-by-step derivation
      1. lower-/.f64N/A

        \[\leadsto x - \frac{1}{\color{blue}{\frac{\frac{-1}{2} \cdot \frac{t \cdot \left(z \cdot \left(y + -1 \cdot {y}^{2}\right)\right)}{{y}^{2}} + \frac{t}{y}}{z}}} \]
    7. Applied rewrites70.5%

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

    if -5.79999999999999961e-118 < z

    1. Initial program 59.2%

      \[x - \frac{\log \left(\left(1 - y\right) + y \cdot e^{z}\right)}{t} \]
    2. Add Preprocessing
    3. Taylor expanded in y around 0

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

        \[\leadsto x - \color{blue}{y \cdot \frac{e^{z} - 1}{t}} \]
      2. div-subN/A

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

        \[\leadsto x - \color{blue}{\left(\frac{e^{z}}{t} - \frac{1}{t}\right) \cdot y} \]
      4. lower-*.f64N/A

        \[\leadsto x - \color{blue}{\left(\frac{e^{z}}{t} - \frac{1}{t}\right) \cdot y} \]
      5. div-subN/A

        \[\leadsto x - \color{blue}{\frac{e^{z} - 1}{t}} \cdot y \]
      6. lower-/.f64N/A

        \[\leadsto x - \color{blue}{\frac{e^{z} - 1}{t}} \cdot y \]
      7. lower-expm1.f6493.4

        \[\leadsto x - \frac{\color{blue}{\mathsf{expm1}\left(z\right)}}{t} \cdot y \]
    5. Applied rewrites93.4%

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

      \[\leadsto x - \left(z \cdot \left(\frac{1}{2} \cdot \frac{z}{t} + \frac{1}{t}\right)\right) \cdot y \]
    7. Step-by-step derivation
      1. Applied rewrites94.1%

        \[\leadsto x - \left(\mathsf{fma}\left(0.5, z, 1\right) \cdot \frac{z}{t}\right) \cdot y \]
      2. Step-by-step derivation
        1. Applied rewrites94.1%

          \[\leadsto x - \frac{\mathsf{fma}\left(z \cdot z, 0.25, -1\right) \cdot \frac{z}{t}}{\mathsf{fma}\left(0.5, z, -1\right)} \cdot y \]
      3. Recombined 2 regimes into one program.
      4. Final simplification84.1%

        \[\leadsto \begin{array}{l} \mathbf{if}\;z \leq -5.8 \cdot 10^{-118}:\\ \;\;\;\;x - \frac{1}{\frac{\mathsf{fma}\left(\frac{-0.5}{y}, \frac{\left(\left(y - y \cdot y\right) \cdot z\right) \cdot t}{y}, \frac{t}{y}\right)}{z}}\\ \mathbf{else}:\\ \;\;\;\;x - \frac{\frac{z}{t} \cdot \mathsf{fma}\left(z \cdot z, 0.25, -1\right)}{\mathsf{fma}\left(0.5, z, -1\right)} \cdot y\\ \end{array} \]
      5. Add Preprocessing

      Alternative 8: 74.9% accurate, 11.3× speedup?

      \[\begin{array}{l} \\ x - \frac{z}{t} \cdot y \end{array} \]
      (FPCore (x y z t) :precision binary64 (- x (* (/ z t) y)))
      double code(double x, double y, double z, double t) {
      	return x - ((z / t) * y);
      }
      
      real(8) function code(x, y, z, t)
          real(8), intent (in) :: x
          real(8), intent (in) :: y
          real(8), intent (in) :: z
          real(8), intent (in) :: t
          code = x - ((z / t) * y)
      end function
      
      public static double code(double x, double y, double z, double t) {
      	return x - ((z / t) * y);
      }
      
      def code(x, y, z, t):
      	return x - ((z / t) * y)
      
      function code(x, y, z, t)
      	return Float64(x - Float64(Float64(z / t) * y))
      end
      
      function tmp = code(x, y, z, t)
      	tmp = x - ((z / t) * y);
      end
      
      code[x_, y_, z_, t_] := N[(x - N[(N[(z / t), $MachinePrecision] * y), $MachinePrecision]), $MachinePrecision]
      
      \begin{array}{l}
      
      \\
      x - \frac{z}{t} \cdot y
      \end{array}
      
      Derivation
      1. Initial program 63.9%

        \[x - \frac{\log \left(\left(1 - y\right) + y \cdot e^{z}\right)}{t} \]
      2. Add Preprocessing
      3. Taylor expanded in y around 0

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

          \[\leadsto x - \color{blue}{y \cdot \frac{e^{z} - 1}{t}} \]
        2. div-subN/A

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

          \[\leadsto x - \color{blue}{\left(\frac{e^{z}}{t} - \frac{1}{t}\right) \cdot y} \]
        4. lower-*.f64N/A

          \[\leadsto x - \color{blue}{\left(\frac{e^{z}}{t} - \frac{1}{t}\right) \cdot y} \]
        5. div-subN/A

          \[\leadsto x - \color{blue}{\frac{e^{z} - 1}{t}} \cdot y \]
        6. lower-/.f64N/A

          \[\leadsto x - \color{blue}{\frac{e^{z} - 1}{t}} \cdot y \]
        7. lower-expm1.f6488.4

          \[\leadsto x - \frac{\color{blue}{\mathsf{expm1}\left(z\right)}}{t} \cdot y \]
      5. Applied rewrites88.4%

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

        \[\leadsto x - \frac{z}{t} \cdot y \]
      7. Step-by-step derivation
        1. Applied rewrites76.9%

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

        Developer Target 1: 74.9% accurate, 1.8× 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 2024270 
        (FPCore (x y z t)
          :name "System.Random.MWC.Distributions:truncatedExp from mwc-random-0.13.3.2"
          :precision binary64
        
          :alt
          (! :herbie-platform default (if (< z -288746230882079470000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000) (- (- x (/ (/ (- 1/2) (* y t)) (* z z))) (* (/ (- 1/2) (* y t)) (/ (/ 2 z) (* z z)))) (- x (/ (log (+ 1 (* z y))) t))))
        
          (- x (/ (log (+ (- 1.0 y) (* y (exp z)))) t)))