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

Percentage Accurate: 62.5% → 93.3%
Time: 16.1s
Alternatives: 11
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 11 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: 62.5% accurate, 1.0× speedup?

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

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

Alternative 1: 93.3% accurate, 0.7× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;e^{z} \cdot y + \left(1 - y\right) \leq 4:\\ \;\;\;\;x - \frac{\mathsf{expm1}\left(z\right)}{t} \cdot y\\ \mathbf{else}:\\ \;\;\;\;x - \frac{\log \left(\mathsf{expm1}\left(z\right) \cdot y\right)}{t}\\ \end{array} \end{array} \]
(FPCore (x y z t)
 :precision binary64
 (if (<= (+ (* (exp z) y) (- 1.0 y)) 4.0)
   (- x (* (/ (expm1 z) t) y))
   (- x (/ (log (* (expm1 z) y)) t))))
double code(double x, double y, double z, double t) {
	double tmp;
	if (((exp(z) * y) + (1.0 - y)) <= 4.0) {
		tmp = x - ((expm1(z) / t) * y);
	} else {
		tmp = x - (log((expm1(z) * y)) / t);
	}
	return tmp;
}
public static double code(double x, double y, double z, double t) {
	double tmp;
	if (((Math.exp(z) * y) + (1.0 - y)) <= 4.0) {
		tmp = x - ((Math.expm1(z) / t) * y);
	} else {
		tmp = x - (Math.log((Math.expm1(z) * y)) / t);
	}
	return tmp;
}
def code(x, y, z, t):
	tmp = 0
	if ((math.exp(z) * y) + (1.0 - y)) <= 4.0:
		tmp = x - ((math.expm1(z) / t) * y)
	else:
		tmp = x - (math.log((math.expm1(z) * y)) / t)
	return tmp
function code(x, y, z, t)
	tmp = 0.0
	if (Float64(Float64(exp(z) * y) + Float64(1.0 - y)) <= 4.0)
		tmp = Float64(x - Float64(Float64(expm1(z) / t) * y));
	else
		tmp = Float64(x - Float64(log(Float64(expm1(z) * y)) / t));
	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], 4.0], N[(x - N[(N[(N[(Exp[z] - 1), $MachinePrecision] / t), $MachinePrecision] * y), $MachinePrecision]), $MachinePrecision], N[(x - N[(N[Log[N[(N[(Exp[z] - 1), $MachinePrecision] * y), $MachinePrecision]], $MachinePrecision] / t), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;e^{z} \cdot y + \left(1 - y\right) \leq 4:\\
\;\;\;\;x - \frac{\mathsf{expm1}\left(z\right)}{t} \cdot y\\

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


\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))) < 4

    1. Initial program 58.3%

      \[x - \frac{\log \left(\left(1 - y\right) + y \cdot e^{z}\right)}{t} \]
    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.f6493.2

        \[\leadsto x - \frac{\color{blue}{\mathsf{expm1}\left(z\right)}}{t} \cdot y \]
    5. Applied rewrites93.2%

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

    if 4 < (+.f64 (-.f64 #s(literal 1 binary64) y) (*.f64 y (exp.f64 z)))

    1. Initial program 94.7%

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

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

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

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

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

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

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

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

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

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

        \[\leadsto x - \frac{\log \color{blue}{\left(y \cdot e^{z} - y \cdot 1\right)}}{t} \]
      10. distribute-lft-out--N/A

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

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

        \[\leadsto x - \frac{\log \color{blue}{\left(\left(e^{z} - 1\right) \cdot y\right)}}{t} \]
      13. lower-expm1.f6497.2

        \[\leadsto x - \frac{\log \left(\color{blue}{\mathsf{expm1}\left(z\right)} \cdot y\right)}{t} \]
    5. Applied rewrites97.2%

      \[\leadsto x - \frac{\log \color{blue}{\left(\mathsf{expm1}\left(z\right) \cdot y\right)}}{t} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification93.8%

    \[\leadsto \begin{array}{l} \mathbf{if}\;e^{z} \cdot y + \left(1 - y\right) \leq 4:\\ \;\;\;\;x - \frac{\mathsf{expm1}\left(z\right)}{t} \cdot y\\ \mathbf{else}:\\ \;\;\;\;x - \frac{\log \left(\mathsf{expm1}\left(z\right) \cdot y\right)}{t}\\ \end{array} \]
  5. Add Preprocessing

Alternative 2: 88.2% accurate, 0.3× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_1 := \frac{\log \left(e^{z} \cdot y + \left(1 - y\right)\right)}{t}\\ \mathbf{if}\;t\_1 \leq -\infty:\\ \;\;\;\;\mathsf{fma}\left(-\log \left(\mathsf{fma}\left(z, y, 1\right)\right), {t}^{-1}, x\right)\\ \mathbf{elif}\;t\_1 \leq -4 \cdot 10^{-15}:\\ \;\;\;\;\frac{\mathsf{log1p}\left(\mathsf{expm1}\left(z\right) \cdot y\right)}{-t}\\ \mathbf{else}:\\ \;\;\;\;x - \frac{\mathsf{expm1}\left(z\right)}{t} \cdot y\\ \end{array} \end{array} \]
(FPCore (x y z t)
 :precision binary64
 (let* ((t_1 (/ (log (+ (* (exp z) y) (- 1.0 y))) t)))
   (if (<= t_1 (- INFINITY))
     (fma (- (log (fma z y 1.0))) (pow t -1.0) x)
     (if (<= t_1 -4e-15)
       (/ (log1p (* (expm1 z) y)) (- t))
       (- x (* (/ (expm1 z) t) y))))))
double code(double x, double y, double z, double t) {
	double t_1 = log(((exp(z) * y) + (1.0 - y))) / t;
	double tmp;
	if (t_1 <= -((double) INFINITY)) {
		tmp = fma(-log(fma(z, y, 1.0)), pow(t, -1.0), x);
	} else if (t_1 <= -4e-15) {
		tmp = log1p((expm1(z) * y)) / -t;
	} else {
		tmp = x - ((expm1(z) / t) * y);
	}
	return tmp;
}
function code(x, y, z, t)
	t_1 = Float64(log(Float64(Float64(exp(z) * y) + Float64(1.0 - y))) / t)
	tmp = 0.0
	if (t_1 <= Float64(-Inf))
		tmp = fma(Float64(-log(fma(z, y, 1.0))), (t ^ -1.0), x);
	elseif (t_1 <= -4e-15)
		tmp = Float64(log1p(Float64(expm1(z) * y)) / Float64(-t));
	else
		tmp = Float64(x - Float64(Float64(expm1(z) / t) * y));
	end
	return tmp
end
code[x_, y_, z_, t_] := Block[{t$95$1 = N[(N[Log[N[(N[(N[Exp[z], $MachinePrecision] * y), $MachinePrecision] + N[(1.0 - y), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] / t), $MachinePrecision]}, If[LessEqual[t$95$1, (-Infinity)], N[((-N[Log[N[(z * y + 1.0), $MachinePrecision]], $MachinePrecision]) * N[Power[t, -1.0], $MachinePrecision] + x), $MachinePrecision], If[LessEqual[t$95$1, -4e-15], N[(N[Log[1 + N[(N[(Exp[z] - 1), $MachinePrecision] * y), $MachinePrecision]], $MachinePrecision] / (-t)), $MachinePrecision], N[(x - N[(N[(N[(Exp[z] - 1), $MachinePrecision] / t), $MachinePrecision] * y), $MachinePrecision]), $MachinePrecision]]]]
\begin{array}{l}

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

\mathbf{elif}\;t\_1 \leq -4 \cdot 10^{-15}:\\
\;\;\;\;\frac{\mathsf{log1p}\left(\mathsf{expm1}\left(z\right) \cdot y\right)}{-t}\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if (/.f64 (log.f64 (+.f64 (-.f64 #s(literal 1 binary64) y) (*.f64 y (exp.f64 z)))) t) < -inf.0

    1. Initial program 2.7%

      \[x - \frac{\log \left(\left(1 - y\right) + y \cdot e^{z}\right)}{t} \]
    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.f6491.3

        \[\leadsto x - \frac{\log \color{blue}{\left(\mathsf{fma}\left(z, y, 1\right)\right)}}{t} \]
    5. Applied rewrites91.3%

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

        \[\leadsto \color{blue}{x - \frac{\log \left(\mathsf{fma}\left(z, y, 1\right)\right)}{t}} \]
      2. sub-negN/A

        \[\leadsto \color{blue}{x + \left(\mathsf{neg}\left(\frac{\log \left(\mathsf{fma}\left(z, y, 1\right)\right)}{t}\right)\right)} \]
      3. +-commutativeN/A

        \[\leadsto \color{blue}{\left(\mathsf{neg}\left(\frac{\log \left(\mathsf{fma}\left(z, y, 1\right)\right)}{t}\right)\right) + x} \]
      4. lift-/.f64N/A

        \[\leadsto \left(\mathsf{neg}\left(\color{blue}{\frac{\log \left(\mathsf{fma}\left(z, y, 1\right)\right)}{t}}\right)\right) + x \]
      5. div-invN/A

        \[\leadsto \left(\mathsf{neg}\left(\color{blue}{\log \left(\mathsf{fma}\left(z, y, 1\right)\right) \cdot \frac{1}{t}}\right)\right) + x \]
      6. distribute-lft-neg-inN/A

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

        \[\leadsto \color{blue}{\mathsf{fma}\left(\mathsf{neg}\left(\log \left(\mathsf{fma}\left(z, y, 1\right)\right)\right), \frac{1}{t}, x\right)} \]
      8. lower-neg.f64N/A

        \[\leadsto \mathsf{fma}\left(\color{blue}{-\log \left(\mathsf{fma}\left(z, y, 1\right)\right)}, \frac{1}{t}, x\right) \]
      9. inv-powN/A

        \[\leadsto \mathsf{fma}\left(-\log \left(\mathsf{fma}\left(z, y, 1\right)\right), \color{blue}{{t}^{-1}}, x\right) \]
      10. lower-pow.f6491.4

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

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

    if -inf.0 < (/.f64 (log.f64 (+.f64 (-.f64 #s(literal 1 binary64) y) (*.f64 y (exp.f64 z)))) t) < -4.0000000000000003e-15

    1. Initial program 97.2%

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

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

        \[\leadsto \color{blue}{\mathsf{neg}\left(\frac{\log \left(\left(1 + y \cdot e^{z}\right) - y\right)}{t}\right)} \]
      2. distribute-neg-frac2N/A

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

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

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

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

        \[\leadsto \frac{\log \left(1 + \color{blue}{\left(y \cdot e^{z} - y\right)}\right)}{\mathsf{neg}\left(t\right)} \]
      7. *-rgt-identityN/A

        \[\leadsto \frac{\log \left(1 + \left(y \cdot e^{z} - \color{blue}{y \cdot 1}\right)\right)}{\mathsf{neg}\left(t\right)} \]
      8. distribute-lft-out--N/A

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

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

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

        \[\leadsto \frac{\mathsf{log1p}\left(\color{blue}{\left(e^{z} - 1\right) \cdot y}\right)}{\mathsf{neg}\left(t\right)} \]
      12. lower-expm1.f64N/A

        \[\leadsto \frac{\mathsf{log1p}\left(\color{blue}{\mathsf{expm1}\left(z\right)} \cdot y\right)}{\mathsf{neg}\left(t\right)} \]
      13. lower-neg.f6475.8

        \[\leadsto \frac{\mathsf{log1p}\left(\mathsf{expm1}\left(z\right) \cdot y\right)}{\color{blue}{-t}} \]
    5. Applied rewrites75.8%

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

    if -4.0000000000000003e-15 < (/.f64 (log.f64 (+.f64 (-.f64 #s(literal 1 binary64) y) (*.f64 y (exp.f64 z)))) t)

    1. Initial program 70.5%

      \[x - \frac{\log \left(\left(1 - y\right) + y \cdot e^{z}\right)}{t} \]
    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.f6492.9

        \[\leadsto x - \frac{\color{blue}{\mathsf{expm1}\left(z\right)}}{t} \cdot y \]
    5. Applied rewrites92.9%

      \[\leadsto x - \color{blue}{\frac{\mathsf{expm1}\left(z\right)}{t} \cdot y} \]
  3. Recombined 3 regimes into one program.
  4. Final simplification91.9%

    \[\leadsto \begin{array}{l} \mathbf{if}\;\frac{\log \left(e^{z} \cdot y + \left(1 - y\right)\right)}{t} \leq -\infty:\\ \;\;\;\;\mathsf{fma}\left(-\log \left(\mathsf{fma}\left(z, y, 1\right)\right), {t}^{-1}, x\right)\\ \mathbf{elif}\;\frac{\log \left(e^{z} \cdot y + \left(1 - y\right)\right)}{t} \leq -4 \cdot 10^{-15}:\\ \;\;\;\;\frac{\mathsf{log1p}\left(\mathsf{expm1}\left(z\right) \cdot y\right)}{-t}\\ \mathbf{else}:\\ \;\;\;\;x - \frac{\mathsf{expm1}\left(z\right)}{t} \cdot y\\ \end{array} \]
  5. Add Preprocessing

Alternative 3: 86.8% accurate, 0.5× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;\frac{\log \left(e^{z} \cdot y + \left(1 - y\right)\right)}{t} \leq -2 \cdot 10^{-11}:\\ \;\;\;\;\mathsf{fma}\left(-\log \left(\mathsf{fma}\left(z, y, 1\right)\right), {t}^{-1}, x\right)\\ \mathbf{else}:\\ \;\;\;\;x - \frac{\mathsf{expm1}\left(z\right)}{t} \cdot y\\ \end{array} \end{array} \]
(FPCore (x y z t)
 :precision binary64
 (if (<= (/ (log (+ (* (exp z) y) (- 1.0 y))) t) -2e-11)
   (fma (- (log (fma z y 1.0))) (pow t -1.0) x)
   (- x (* (/ (expm1 z) t) y))))
double code(double x, double y, double z, double t) {
	double tmp;
	if ((log(((exp(z) * y) + (1.0 - y))) / t) <= -2e-11) {
		tmp = fma(-log(fma(z, y, 1.0)), pow(t, -1.0), x);
	} else {
		tmp = x - ((expm1(z) / t) * y);
	}
	return tmp;
}
function code(x, y, z, t)
	tmp = 0.0
	if (Float64(log(Float64(Float64(exp(z) * y) + Float64(1.0 - y))) / t) <= -2e-11)
		tmp = fma(Float64(-log(fma(z, y, 1.0))), (t ^ -1.0), x);
	else
		tmp = Float64(x - Float64(Float64(expm1(z) / t) * y));
	end
	return tmp
end
code[x_, y_, z_, t_] := If[LessEqual[N[(N[Log[N[(N[(N[Exp[z], $MachinePrecision] * y), $MachinePrecision] + N[(1.0 - y), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] / t), $MachinePrecision], -2e-11], N[((-N[Log[N[(z * y + 1.0), $MachinePrecision]], $MachinePrecision]) * N[Power[t, -1.0], $MachinePrecision] + x), $MachinePrecision], N[(x - N[(N[(N[(Exp[z] - 1), $MachinePrecision] / t), $MachinePrecision] * y), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;\frac{\log \left(e^{z} \cdot y + \left(1 - y\right)\right)}{t} \leq -2 \cdot 10^{-11}:\\
\;\;\;\;\mathsf{fma}\left(-\log \left(\mathsf{fma}\left(z, y, 1\right)\right), {t}^{-1}, x\right)\\

\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 (/.f64 (log.f64 (+.f64 (-.f64 #s(literal 1 binary64) y) (*.f64 y (exp.f64 z)))) t) < -1.99999999999999988e-11

    1. Initial program 27.4%

      \[x - \frac{\log \left(\left(1 - y\right) + y \cdot e^{z}\right)}{t} \]
    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.f6473.5

        \[\leadsto x - \frac{\log \color{blue}{\left(\mathsf{fma}\left(z, y, 1\right)\right)}}{t} \]
    5. Applied rewrites73.5%

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

        \[\leadsto \color{blue}{x - \frac{\log \left(\mathsf{fma}\left(z, y, 1\right)\right)}{t}} \]
      2. sub-negN/A

        \[\leadsto \color{blue}{x + \left(\mathsf{neg}\left(\frac{\log \left(\mathsf{fma}\left(z, y, 1\right)\right)}{t}\right)\right)} \]
      3. +-commutativeN/A

        \[\leadsto \color{blue}{\left(\mathsf{neg}\left(\frac{\log \left(\mathsf{fma}\left(z, y, 1\right)\right)}{t}\right)\right) + x} \]
      4. lift-/.f64N/A

        \[\leadsto \left(\mathsf{neg}\left(\color{blue}{\frac{\log \left(\mathsf{fma}\left(z, y, 1\right)\right)}{t}}\right)\right) + x \]
      5. div-invN/A

        \[\leadsto \left(\mathsf{neg}\left(\color{blue}{\log \left(\mathsf{fma}\left(z, y, 1\right)\right) \cdot \frac{1}{t}}\right)\right) + x \]
      6. distribute-lft-neg-inN/A

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

        \[\leadsto \color{blue}{\mathsf{fma}\left(\mathsf{neg}\left(\log \left(\mathsf{fma}\left(z, y, 1\right)\right)\right), \frac{1}{t}, x\right)} \]
      8. lower-neg.f64N/A

        \[\leadsto \mathsf{fma}\left(\color{blue}{-\log \left(\mathsf{fma}\left(z, y, 1\right)\right)}, \frac{1}{t}, x\right) \]
      9. inv-powN/A

        \[\leadsto \mathsf{fma}\left(-\log \left(\mathsf{fma}\left(z, y, 1\right)\right), \color{blue}{{t}^{-1}}, x\right) \]
      10. lower-pow.f6473.5

        \[\leadsto \mathsf{fma}\left(-\log \left(\mathsf{fma}\left(z, y, 1\right)\right), \color{blue}{{t}^{-1}}, x\right) \]
    7. Applied rewrites73.5%

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

    if -1.99999999999999988e-11 < (/.f64 (log.f64 (+.f64 (-.f64 #s(literal 1 binary64) y) (*.f64 y (exp.f64 z)))) t)

    1. Initial program 70.7%

      \[x - \frac{\log \left(\left(1 - y\right) + y \cdot e^{z}\right)}{t} \]
    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.f6492.5

        \[\leadsto x - \frac{\color{blue}{\mathsf{expm1}\left(z\right)}}{t} \cdot y \]
    5. Applied rewrites92.5%

      \[\leadsto x - \color{blue}{\frac{\mathsf{expm1}\left(z\right)}{t} \cdot y} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification89.4%

    \[\leadsto \begin{array}{l} \mathbf{if}\;\frac{\log \left(e^{z} \cdot y + \left(1 - y\right)\right)}{t} \leq -2 \cdot 10^{-11}:\\ \;\;\;\;\mathsf{fma}\left(-\log \left(\mathsf{fma}\left(z, y, 1\right)\right), {t}^{-1}, x\right)\\ \mathbf{else}:\\ \;\;\;\;x - \frac{\mathsf{expm1}\left(z\right)}{t} \cdot y\\ \end{array} \]
  5. Add Preprocessing

Alternative 4: 88.3% accurate, 0.6× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_1 := e^{z} \cdot y + \left(1 - y\right)\\ \mathbf{if}\;t\_1 \leq 0:\\ \;\;\;\;x - \frac{z \cdot y}{t}\\ \mathbf{elif}\;t\_1 \leq 10^{+99}:\\ \;\;\;\;x - \frac{y}{t} \cdot \mathsf{expm1}\left(z\right)\\ \mathbf{else}:\\ \;\;\;\;x - \frac{\log 1}{t}\\ \end{array} \end{array} \]
(FPCore (x y z t)
 :precision binary64
 (let* ((t_1 (+ (* (exp z) y) (- 1.0 y))))
   (if (<= t_1 0.0)
     (- x (/ (* z y) t))
     (if (<= t_1 1e+99) (- x (* (/ y t) (expm1 z))) (- x (/ (log 1.0) 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 - ((z * y) / t);
	} else if (t_1 <= 1e+99) {
		tmp = x - ((y / t) * expm1(z));
	} else {
		tmp = x - (log(1.0) / t);
	}
	return tmp;
}
public static double code(double x, double y, double z, double t) {
	double t_1 = (Math.exp(z) * y) + (1.0 - y);
	double tmp;
	if (t_1 <= 0.0) {
		tmp = x - ((z * y) / t);
	} else if (t_1 <= 1e+99) {
		tmp = x - ((y / t) * Math.expm1(z));
	} else {
		tmp = x - (Math.log(1.0) / t);
	}
	return tmp;
}
def code(x, y, z, t):
	t_1 = (math.exp(z) * y) + (1.0 - y)
	tmp = 0
	if t_1 <= 0.0:
		tmp = x - ((z * y) / t)
	elif t_1 <= 1e+99:
		tmp = x - ((y / t) * math.expm1(z))
	else:
		tmp = x - (math.log(1.0) / 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(Float64(z * y) / t));
	elseif (t_1 <= 1e+99)
		tmp = Float64(x - Float64(Float64(y / t) * expm1(z)));
	else
		tmp = Float64(x - Float64(log(1.0) / 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[(N[(z * y), $MachinePrecision] / t), $MachinePrecision]), $MachinePrecision], If[LessEqual[t$95$1, 1e+99], N[(x - N[(N[(y / t), $MachinePrecision] * N[(Exp[z] - 1), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(x - N[(N[Log[1.0], $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{z \cdot y}{t}\\

\mathbf{elif}\;t\_1 \leq 10^{+99}:\\
\;\;\;\;x - \frac{y}{t} \cdot \mathsf{expm1}\left(z\right)\\

\mathbf{else}:\\
\;\;\;\;x - \frac{\log 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 2.2%

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

      \[\leadsto x - \frac{\color{blue}{y \cdot z}}{t} \]
    4. Step-by-step derivation
      1. *-commutativeN/A

        \[\leadsto x - \frac{\color{blue}{z \cdot y}}{t} \]
      2. lower-*.f6479.3

        \[\leadsto x - \frac{\color{blue}{z \cdot y}}{t} \]
    5. Applied rewrites79.3%

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

    if 0.0 < (+.f64 (-.f64 #s(literal 1 binary64) y) (*.f64 y (exp.f64 z))) < 9.9999999999999997e98

    1. Initial program 85.0%

      \[x - \frac{\log \left(\left(1 - y\right) + y \cdot e^{z}\right)}{t} \]
    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.f6495.7

        \[\leadsto x - \frac{\color{blue}{\mathsf{expm1}\left(z\right)}}{t} \cdot y \]
    5. Applied rewrites95.7%

      \[\leadsto x - \color{blue}{\frac{\mathsf{expm1}\left(z\right)}{t} \cdot y} \]
    6. Step-by-step derivation
      1. Applied rewrites95.8%

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

      if 9.9999999999999997e98 < (+.f64 (-.f64 #s(literal 1 binary64) y) (*.f64 y (exp.f64 z)))

      1. Initial program 91.1%

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

        \[\leadsto x - \frac{\log \color{blue}{1}}{t} \]
      4. Step-by-step derivation
        1. Applied rewrites65.8%

          \[\leadsto x - \frac{\log \color{blue}{1}}{t} \]
      5. Recombined 3 regimes into one program.
      6. Final simplification88.8%

        \[\leadsto \begin{array}{l} \mathbf{if}\;e^{z} \cdot y + \left(1 - y\right) \leq 0:\\ \;\;\;\;x - \frac{z \cdot y}{t}\\ \mathbf{elif}\;e^{z} \cdot y + \left(1 - y\right) \leq 10^{+99}:\\ \;\;\;\;x - \frac{y}{t} \cdot \mathsf{expm1}\left(z\right)\\ \mathbf{else}:\\ \;\;\;\;x - \frac{\log 1}{t}\\ \end{array} \]
      7. Add Preprocessing

      Alternative 5: 86.8% accurate, 0.6× speedup?

      \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;\frac{\log \left(e^{z} \cdot y + \left(1 - y\right)\right)}{t} \leq -2 \cdot 10^{-11}:\\ \;\;\;\;x - \frac{\log \left(\mathsf{fma}\left(z, y, 1\right)\right)}{t}\\ \mathbf{else}:\\ \;\;\;\;x - \frac{\mathsf{expm1}\left(z\right)}{t} \cdot y\\ \end{array} \end{array} \]
      (FPCore (x y z t)
       :precision binary64
       (if (<= (/ (log (+ (* (exp z) y) (- 1.0 y))) t) -2e-11)
         (- 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 ((log(((exp(z) * y) + (1.0 - y))) / t) <= -2e-11) {
      		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 (Float64(log(Float64(Float64(exp(z) * y) + Float64(1.0 - y))) / t) <= -2e-11)
      		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[N[(N[Log[N[(N[(N[Exp[z], $MachinePrecision] * y), $MachinePrecision] + N[(1.0 - y), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] / t), $MachinePrecision], -2e-11], 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}\;\frac{\log \left(e^{z} \cdot y + \left(1 - y\right)\right)}{t} \leq -2 \cdot 10^{-11}:\\
      \;\;\;\;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 (/.f64 (log.f64 (+.f64 (-.f64 #s(literal 1 binary64) y) (*.f64 y (exp.f64 z)))) t) < -1.99999999999999988e-11

        1. Initial program 27.4%

          \[x - \frac{\log \left(\left(1 - y\right) + y \cdot e^{z}\right)}{t} \]
        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.f6473.5

            \[\leadsto x - \frac{\log \color{blue}{\left(\mathsf{fma}\left(z, y, 1\right)\right)}}{t} \]
        5. Applied rewrites73.5%

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

        if -1.99999999999999988e-11 < (/.f64 (log.f64 (+.f64 (-.f64 #s(literal 1 binary64) y) (*.f64 y (exp.f64 z)))) t)

        1. Initial program 70.7%

          \[x - \frac{\log \left(\left(1 - y\right) + y \cdot e^{z}\right)}{t} \]
        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.f6492.5

            \[\leadsto x - \frac{\color{blue}{\mathsf{expm1}\left(z\right)}}{t} \cdot y \]
        5. Applied rewrites92.5%

          \[\leadsto x - \color{blue}{\frac{\mathsf{expm1}\left(z\right)}{t} \cdot y} \]
      3. Recombined 2 regimes into one program.
      4. Final simplification89.4%

        \[\leadsto \begin{array}{l} \mathbf{if}\;\frac{\log \left(e^{z} \cdot y + \left(1 - y\right)\right)}{t} \leq -2 \cdot 10^{-11}:\\ \;\;\;\;x - \frac{\log \left(\mathsf{fma}\left(z, y, 1\right)\right)}{t}\\ \mathbf{else}:\\ \;\;\;\;x - \frac{\mathsf{expm1}\left(z\right)}{t} \cdot y\\ \end{array} \]
      5. Add Preprocessing

      Alternative 6: 88.2% accurate, 1.0× speedup?

      \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;e^{z} \cdot y + \left(1 - y\right) \leq 10^{+99}:\\ \;\;\;\;x - \frac{\mathsf{expm1}\left(z\right)}{t} \cdot y\\ \mathbf{else}:\\ \;\;\;\;x - \frac{\log 1}{t}\\ \end{array} \end{array} \]
      (FPCore (x y z t)
       :precision binary64
       (if (<= (+ (* (exp z) y) (- 1.0 y)) 1e+99)
         (- x (* (/ (expm1 z) t) y))
         (- x (/ (log 1.0) t))))
      double code(double x, double y, double z, double t) {
      	double tmp;
      	if (((exp(z) * y) + (1.0 - y)) <= 1e+99) {
      		tmp = x - ((expm1(z) / t) * y);
      	} else {
      		tmp = x - (log(1.0) / t);
      	}
      	return tmp;
      }
      
      public static double code(double x, double y, double z, double t) {
      	double tmp;
      	if (((Math.exp(z) * y) + (1.0 - y)) <= 1e+99) {
      		tmp = x - ((Math.expm1(z) / t) * y);
      	} else {
      		tmp = x - (Math.log(1.0) / t);
      	}
      	return tmp;
      }
      
      def code(x, y, z, t):
      	tmp = 0
      	if ((math.exp(z) * y) + (1.0 - y)) <= 1e+99:
      		tmp = x - ((math.expm1(z) / t) * y)
      	else:
      		tmp = x - (math.log(1.0) / t)
      	return tmp
      
      function code(x, y, z, t)
      	tmp = 0.0
      	if (Float64(Float64(exp(z) * y) + Float64(1.0 - y)) <= 1e+99)
      		tmp = Float64(x - Float64(Float64(expm1(z) / t) * y));
      	else
      		tmp = Float64(x - Float64(log(1.0) / t));
      	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], 1e+99], N[(x - N[(N[(N[(Exp[z] - 1), $MachinePrecision] / t), $MachinePrecision] * y), $MachinePrecision]), $MachinePrecision], N[(x - N[(N[Log[1.0], $MachinePrecision] / t), $MachinePrecision]), $MachinePrecision]]
      
      \begin{array}{l}
      
      \\
      \begin{array}{l}
      \mathbf{if}\;e^{z} \cdot y + \left(1 - y\right) \leq 10^{+99}:\\
      \;\;\;\;x - \frac{\mathsf{expm1}\left(z\right)}{t} \cdot y\\
      
      \mathbf{else}:\\
      \;\;\;\;x - \frac{\log 1}{t}\\
      
      
      \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))) < 9.9999999999999997e98

        1. Initial program 61.0%

          \[x - \frac{\log \left(\left(1 - y\right) + y \cdot e^{z}\right)}{t} \]
        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.f6490.8

            \[\leadsto x - \frac{\color{blue}{\mathsf{expm1}\left(z\right)}}{t} \cdot y \]
        5. Applied rewrites90.8%

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

        if 9.9999999999999997e98 < (+.f64 (-.f64 #s(literal 1 binary64) y) (*.f64 y (exp.f64 z)))

        1. Initial program 91.1%

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

          \[\leadsto x - \frac{\log \color{blue}{1}}{t} \]
        4. Step-by-step derivation
          1. Applied rewrites65.8%

            \[\leadsto x - \frac{\log \color{blue}{1}}{t} \]
        5. Recombined 2 regimes into one program.
        6. Final simplification88.7%

          \[\leadsto \begin{array}{l} \mathbf{if}\;e^{z} \cdot y + \left(1 - y\right) \leq 10^{+99}:\\ \;\;\;\;x - \frac{\mathsf{expm1}\left(z\right)}{t} \cdot y\\ \mathbf{else}:\\ \;\;\;\;x - \frac{\log 1}{t}\\ \end{array} \]
        7. Add Preprocessing

        Alternative 7: 75.5% accurate, 1.6× speedup?

        \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;e^{z} \leq 0.0002:\\ \;\;\;\;x - \frac{y}{t} \cdot z\\ \mathbf{else}:\\ \;\;\;\;x - \left(\frac{z}{t} \cdot \mathsf{fma}\left(0.5, z, 1\right)\right) \cdot y\\ \end{array} \end{array} \]
        (FPCore (x y z t)
         :precision binary64
         (if (<= (exp z) 0.0002)
           (- x (* (/ y t) z))
           (- x (* (* (/ z t) (fma 0.5 z 1.0)) y))))
        double code(double x, double y, double z, double t) {
        	double tmp;
        	if (exp(z) <= 0.0002) {
        		tmp = x - ((y / t) * z);
        	} else {
        		tmp = x - (((z / t) * fma(0.5, z, 1.0)) * y);
        	}
        	return tmp;
        }
        
        function code(x, y, z, t)
        	tmp = 0.0
        	if (exp(z) <= 0.0002)
        		tmp = Float64(x - Float64(Float64(y / t) * z));
        	else
        		tmp = Float64(x - Float64(Float64(Float64(z / t) * fma(0.5, z, 1.0)) * y));
        	end
        	return tmp
        end
        
        code[x_, y_, z_, t_] := If[LessEqual[N[Exp[z], $MachinePrecision], 0.0002], N[(x - N[(N[(y / t), $MachinePrecision] * z), $MachinePrecision]), $MachinePrecision], N[(x - N[(N[(N[(z / t), $MachinePrecision] * N[(0.5 * z + 1.0), $MachinePrecision]), $MachinePrecision] * y), $MachinePrecision]), $MachinePrecision]]
        
        \begin{array}{l}
        
        \\
        \begin{array}{l}
        \mathbf{if}\;e^{z} \leq 0.0002:\\
        \;\;\;\;x - \frac{y}{t} \cdot z\\
        
        \mathbf{else}:\\
        \;\;\;\;x - \left(\frac{z}{t} \cdot \mathsf{fma}\left(0.5, z, 1\right)\right) \cdot y\\
        
        
        \end{array}
        \end{array}
        
        Derivation
        1. Split input into 2 regimes
        2. if (exp.f64 z) < 2.0000000000000001e-4

          1. Initial program 88.9%

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

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

              \[\leadsto x - \color{blue}{\frac{y}{t} \cdot z} \]
            2. lower-*.f64N/A

              \[\leadsto x - \color{blue}{\frac{y}{t} \cdot z} \]
            3. lower-/.f6457.2

              \[\leadsto x - \color{blue}{\frac{y}{t}} \cdot z \]
          5. Applied rewrites57.2%

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

          if 2.0000000000000001e-4 < (exp.f64 z)

          1. Initial program 50.2%

            \[x - \frac{\log \left(\left(1 - y\right) + y \cdot e^{z}\right)}{t} \]
          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.f6489.1

              \[\leadsto x - \frac{\color{blue}{\mathsf{expm1}\left(z\right)}}{t} \cdot y \]
          5. Applied rewrites89.1%

            \[\leadsto x - \color{blue}{\frac{\mathsf{expm1}\left(z\right)}{t} \cdot y} \]
          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 rewrites89.7%

              \[\leadsto x - \left(\mathsf{fma}\left(0.5, z, 1\right) \cdot \frac{z}{t}\right) \cdot y \]
          8. Recombined 2 regimes into one program.
          9. Final simplification78.5%

            \[\leadsto \begin{array}{l} \mathbf{if}\;e^{z} \leq 0.0002:\\ \;\;\;\;x - \frac{y}{t} \cdot z\\ \mathbf{else}:\\ \;\;\;\;x - \left(\frac{z}{t} \cdot \mathsf{fma}\left(0.5, z, 1\right)\right) \cdot y\\ \end{array} \]
          10. Add Preprocessing

          Alternative 8: 75.4% accurate, 1.6× speedup?

          \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;e^{z} \cdot y + \left(1 - y\right) \leq 0:\\ \;\;\;\;x - \frac{z \cdot y}{t}\\ \mathbf{else}:\\ \;\;\;\;x - \frac{y}{t} \cdot z\\ \end{array} \end{array} \]
          (FPCore (x y z t)
           :precision binary64
           (if (<= (+ (* (exp z) y) (- 1.0 y)) 0.0)
             (- x (/ (* z y) t))
             (- x (* (/ y t) z))))
          double code(double x, double y, double z, double t) {
          	double tmp;
          	if (((exp(z) * y) + (1.0 - y)) <= 0.0) {
          		tmp = x - ((z * y) / t);
          	} 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 (((exp(z) * y) + (1.0d0 - y)) <= 0.0d0) then
                  tmp = x - ((z * y) / t)
              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 (((Math.exp(z) * y) + (1.0 - y)) <= 0.0) {
          		tmp = x - ((z * y) / t);
          	} else {
          		tmp = x - ((y / t) * z);
          	}
          	return tmp;
          }
          
          def code(x, y, z, t):
          	tmp = 0
          	if ((math.exp(z) * y) + (1.0 - y)) <= 0.0:
          		tmp = x - ((z * y) / t)
          	else:
          		tmp = x - ((y / t) * z)
          	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(Float64(z * y) / t));
          	else
          		tmp = Float64(x - Float64(Float64(y / t) * z));
          	end
          	return tmp
          end
          
          function tmp_2 = code(x, y, z, t)
          	tmp = 0.0;
          	if (((exp(z) * y) + (1.0 - y)) <= 0.0)
          		tmp = x - ((z * y) / t);
          	else
          		tmp = x - ((y / t) * z);
          	end
          	tmp_2 = 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[(N[(z * y), $MachinePrecision] / t), $MachinePrecision]), $MachinePrecision], N[(x - N[(N[(y / t), $MachinePrecision] * z), $MachinePrecision]), $MachinePrecision]]
          
          \begin{array}{l}
          
          \\
          \begin{array}{l}
          \mathbf{if}\;e^{z} \cdot y + \left(1 - y\right) \leq 0:\\
          \;\;\;\;x - \frac{z \cdot y}{t}\\
          
          \mathbf{else}:\\
          \;\;\;\;x - \frac{y}{t} \cdot z\\
          
          
          \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 2.2%

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

              \[\leadsto x - \frac{\color{blue}{y \cdot z}}{t} \]
            4. Step-by-step derivation
              1. *-commutativeN/A

                \[\leadsto x - \frac{\color{blue}{z \cdot y}}{t} \]
              2. lower-*.f6479.3

                \[\leadsto x - \frac{\color{blue}{z \cdot y}}{t} \]
            5. Applied rewrites79.3%

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

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

            1. Initial program 85.8%

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

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

                \[\leadsto x - \color{blue}{\frac{y}{t} \cdot z} \]
              2. lower-*.f64N/A

                \[\leadsto x - \color{blue}{\frac{y}{t} \cdot z} \]
              3. lower-/.f6477.8

                \[\leadsto x - \color{blue}{\frac{y}{t}} \cdot z \]
            5. Applied rewrites77.8%

              \[\leadsto x - \color{blue}{\frac{y}{t} \cdot z} \]
          3. Recombined 2 regimes into one program.
          4. Final simplification78.2%

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

          Alternative 9: 75.4% accurate, 1.8× speedup?

          \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;e^{z} \leq 0.9999999:\\ \;\;\;\;x - \frac{y}{t} \cdot z\\ \mathbf{else}:\\ \;\;\;\;x - \frac{z}{t} \cdot y\\ \end{array} \end{array} \]
          (FPCore (x y z t)
           :precision binary64
           (if (<= (exp z) 0.9999999) (- x (* (/ y t) z)) (- x (* (/ z t) y))))
          double code(double x, double y, double z, double t) {
          	double tmp;
          	if (exp(z) <= 0.9999999) {
          		tmp = x - ((y / t) * z);
          	} else {
          		tmp = x - ((z / t) * y);
          	}
          	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 (exp(z) <= 0.9999999d0) then
                  tmp = x - ((y / t) * z)
              else
                  tmp = x - ((z / t) * y)
              end if
              code = tmp
          end function
          
          public static double code(double x, double y, double z, double t) {
          	double tmp;
          	if (Math.exp(z) <= 0.9999999) {
          		tmp = x - ((y / t) * z);
          	} else {
          		tmp = x - ((z / t) * y);
          	}
          	return tmp;
          }
          
          def code(x, y, z, t):
          	tmp = 0
          	if math.exp(z) <= 0.9999999:
          		tmp = x - ((y / t) * z)
          	else:
          		tmp = x - ((z / t) * y)
          	return tmp
          
          function code(x, y, z, t)
          	tmp = 0.0
          	if (exp(z) <= 0.9999999)
          		tmp = Float64(x - Float64(Float64(y / t) * z));
          	else
          		tmp = Float64(x - Float64(Float64(z / t) * y));
          	end
          	return tmp
          end
          
          function tmp_2 = code(x, y, z, t)
          	tmp = 0.0;
          	if (exp(z) <= 0.9999999)
          		tmp = x - ((y / t) * z);
          	else
          		tmp = x - ((z / t) * y);
          	end
          	tmp_2 = tmp;
          end
          
          code[x_, y_, z_, t_] := If[LessEqual[N[Exp[z], $MachinePrecision], 0.9999999], N[(x - N[(N[(y / t), $MachinePrecision] * z), $MachinePrecision]), $MachinePrecision], N[(x - N[(N[(z / t), $MachinePrecision] * y), $MachinePrecision]), $MachinePrecision]]
          
          \begin{array}{l}
          
          \\
          \begin{array}{l}
          \mathbf{if}\;e^{z} \leq 0.9999999:\\
          \;\;\;\;x - \frac{y}{t} \cdot z\\
          
          \mathbf{else}:\\
          \;\;\;\;x - \frac{z}{t} \cdot y\\
          
          
          \end{array}
          \end{array}
          
          Derivation
          1. Split input into 2 regimes
          2. if (exp.f64 z) < 0.999999900000000053

            1. Initial program 87.9%

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

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

                \[\leadsto x - \color{blue}{\frac{y}{t} \cdot z} \]
              2. lower-*.f64N/A

                \[\leadsto x - \color{blue}{\frac{y}{t} \cdot z} \]
              3. lower-/.f6456.6

                \[\leadsto x - \color{blue}{\frac{y}{t}} \cdot z \]
            5. Applied rewrites56.6%

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

            if 0.999999900000000053 < (exp.f64 z)

            1. Initial program 50.4%

              \[x - \frac{\log \left(\left(1 - y\right) + y \cdot e^{z}\right)}{t} \]
            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.f6489.6

                \[\leadsto x - \frac{\color{blue}{\mathsf{expm1}\left(z\right)}}{t} \cdot y \]
            5. Applied rewrites89.6%

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

              \[\leadsto x - \frac{z}{t} \cdot y \]
            7. Step-by-step derivation
              1. Applied rewrites89.8%

                \[\leadsto x - \frac{z}{t} \cdot y \]
            8. Recombined 2 regimes into one program.
            9. Add Preprocessing

            Alternative 10: 82.2% accurate, 1.9× speedup?

            \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;z \leq -1.9:\\ \;\;\;\;x - \frac{\log 1}{t}\\ \mathbf{else}:\\ \;\;\;\;x - \left(\frac{z}{t} \cdot \mathsf{fma}\left(0.5, z, 1\right)\right) \cdot y\\ \end{array} \end{array} \]
            (FPCore (x y z t)
             :precision binary64
             (if (<= z -1.9)
               (- x (/ (log 1.0) t))
               (- x (* (* (/ z t) (fma 0.5 z 1.0)) y))))
            double code(double x, double y, double z, double t) {
            	double tmp;
            	if (z <= -1.9) {
            		tmp = x - (log(1.0) / t);
            	} else {
            		tmp = x - (((z / t) * fma(0.5, z, 1.0)) * y);
            	}
            	return tmp;
            }
            
            function code(x, y, z, t)
            	tmp = 0.0
            	if (z <= -1.9)
            		tmp = Float64(x - Float64(log(1.0) / t));
            	else
            		tmp = Float64(x - Float64(Float64(Float64(z / t) * fma(0.5, z, 1.0)) * y));
            	end
            	return tmp
            end
            
            code[x_, y_, z_, t_] := If[LessEqual[z, -1.9], N[(x - N[(N[Log[1.0], $MachinePrecision] / t), $MachinePrecision]), $MachinePrecision], N[(x - N[(N[(N[(z / t), $MachinePrecision] * N[(0.5 * z + 1.0), $MachinePrecision]), $MachinePrecision] * y), $MachinePrecision]), $MachinePrecision]]
            
            \begin{array}{l}
            
            \\
            \begin{array}{l}
            \mathbf{if}\;z \leq -1.9:\\
            \;\;\;\;x - \frac{\log 1}{t}\\
            
            \mathbf{else}:\\
            \;\;\;\;x - \left(\frac{z}{t} \cdot \mathsf{fma}\left(0.5, z, 1\right)\right) \cdot y\\
            
            
            \end{array}
            \end{array}
            
            Derivation
            1. Split input into 2 regimes
            2. if z < -1.8999999999999999

              1. Initial program 88.9%

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

                \[\leadsto x - \frac{\log \color{blue}{1}}{t} \]
              4. Step-by-step derivation
                1. Applied rewrites75.1%

                  \[\leadsto x - \frac{\log \color{blue}{1}}{t} \]

                if -1.8999999999999999 < z

                1. Initial program 50.2%

                  \[x - \frac{\log \left(\left(1 - y\right) + y \cdot e^{z}\right)}{t} \]
                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.f6489.1

                    \[\leadsto x - \frac{\color{blue}{\mathsf{expm1}\left(z\right)}}{t} \cdot y \]
                5. Applied rewrites89.1%

                  \[\leadsto x - \color{blue}{\frac{\mathsf{expm1}\left(z\right)}{t} \cdot y} \]
                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 rewrites89.7%

                    \[\leadsto x - \left(\mathsf{fma}\left(0.5, z, 1\right) \cdot \frac{z}{t}\right) \cdot y \]
                8. Recombined 2 regimes into one program.
                9. Final simplification84.7%

                  \[\leadsto \begin{array}{l} \mathbf{if}\;z \leq -1.9:\\ \;\;\;\;x - \frac{\log 1}{t}\\ \mathbf{else}:\\ \;\;\;\;x - \left(\frac{z}{t} \cdot \mathsf{fma}\left(0.5, z, 1\right)\right) \cdot y\\ \end{array} \]
                10. Add Preprocessing

                Alternative 11: 74.3% 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 63.5%

                  \[x - \frac{\log \left(\left(1 - y\right) + y \cdot e^{z}\right)}{t} \]
                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.f6486.4

                    \[\leadsto x - \frac{\color{blue}{\mathsf{expm1}\left(z\right)}}{t} \cdot y \]
                5. Applied rewrites86.4%

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

                  \[\leadsto x - \frac{z}{t} \cdot y \]
                7. Step-by-step derivation
                  1. Applied rewrites75.1%

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

                  Developer Target 1: 74.5% 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 2024296 
                  (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)))