exp-w (used to crash)

Percentage Accurate: 99.5% → 99.5%
Time: 12.7s
Alternatives: 7
Speedup: N/A×

Specification

?
\[\begin{array}{l} \\ e^{-w} \cdot {\ell}^{\left(e^{w}\right)} \end{array} \]
(FPCore (w l) :precision binary64 (* (exp (- w)) (pow l (exp w))))
double code(double w, double l) {
	return exp(-w) * pow(l, exp(w));
}
real(8) function code(w, l)
    real(8), intent (in) :: w
    real(8), intent (in) :: l
    code = exp(-w) * (l ** exp(w))
end function
public static double code(double w, double l) {
	return Math.exp(-w) * Math.pow(l, Math.exp(w));
}
def code(w, l):
	return math.exp(-w) * math.pow(l, math.exp(w))
function code(w, l)
	return Float64(exp(Float64(-w)) * (l ^ exp(w)))
end
function tmp = code(w, l)
	tmp = exp(-w) * (l ^ exp(w));
end
code[w_, l_] := N[(N[Exp[(-w)], $MachinePrecision] * N[Power[l, N[Exp[w], $MachinePrecision]], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
e^{-w} \cdot {\ell}^{\left(e^{w}\right)}
\end{array}

Sampling outcomes in binary64 precision:

Local Percentage Accuracy vs ?

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

Accuracy vs Speed?

Herbie found 7 alternatives:

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

Initial Program: 99.5% accurate, 1.0× speedup?

\[\begin{array}{l} \\ e^{-w} \cdot {\ell}^{\left(e^{w}\right)} \end{array} \]
(FPCore (w l) :precision binary64 (* (exp (- w)) (pow l (exp w))))
double code(double w, double l) {
	return exp(-w) * pow(l, exp(w));
}
real(8) function code(w, l)
    real(8), intent (in) :: w
    real(8), intent (in) :: l
    code = exp(-w) * (l ** exp(w))
end function
public static double code(double w, double l) {
	return Math.exp(-w) * Math.pow(l, Math.exp(w));
}
def code(w, l):
	return math.exp(-w) * math.pow(l, math.exp(w))
function code(w, l)
	return Float64(exp(Float64(-w)) * (l ^ exp(w)))
end
function tmp = code(w, l)
	tmp = exp(-w) * (l ^ exp(w));
end
code[w_, l_] := N[(N[Exp[(-w)], $MachinePrecision] * N[Power[l, N[Exp[w], $MachinePrecision]], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
e^{-w} \cdot {\ell}^{\left(e^{w}\right)}
\end{array}

Alternative 1: 99.5% accurate, 0.5× speedup?

\[\begin{array}{l} \\ \frac{1}{\sqrt[3]{e^{w + w}}} \cdot \frac{{\ell}^{\left(e^{w}\right)}}{\sqrt[3]{e^{w}}} \end{array} \]
(FPCore (w l)
 :precision binary64
 (* (/ 1.0 (cbrt (exp (+ w w)))) (/ (pow l (exp w)) (cbrt (exp w)))))
double code(double w, double l) {
	return (1.0 / cbrt(exp((w + w)))) * (pow(l, exp(w)) / cbrt(exp(w)));
}
public static double code(double w, double l) {
	return (1.0 / Math.cbrt(Math.exp((w + w)))) * (Math.pow(l, Math.exp(w)) / Math.cbrt(Math.exp(w)));
}
function code(w, l)
	return Float64(Float64(1.0 / cbrt(exp(Float64(w + w)))) * Float64((l ^ exp(w)) / cbrt(exp(w))))
end
code[w_, l_] := N[(N[(1.0 / N[Power[N[Exp[N[(w + w), $MachinePrecision]], $MachinePrecision], 1/3], $MachinePrecision]), $MachinePrecision] * N[(N[Power[l, N[Exp[w], $MachinePrecision]], $MachinePrecision] / N[Power[N[Exp[w], $MachinePrecision], 1/3], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{1}{\sqrt[3]{e^{w + w}}} \cdot \frac{{\ell}^{\left(e^{w}\right)}}{\sqrt[3]{e^{w}}}
\end{array}
Derivation
  1. Initial program 99.6%

    \[e^{-w} \cdot {\ell}^{\left(e^{w}\right)} \]
  2. Step-by-step derivation
    1. exp-neg99.6%

      \[\leadsto \color{blue}{\frac{1}{e^{w}}} \cdot {\ell}^{\left(e^{w}\right)} \]
    2. associate-*l/99.6%

      \[\leadsto \color{blue}{\frac{1 \cdot {\ell}^{\left(e^{w}\right)}}{e^{w}}} \]
    3. *-lft-identity99.6%

      \[\leadsto \frac{\color{blue}{{\ell}^{\left(e^{w}\right)}}}{e^{w}} \]
  3. Simplified99.6%

    \[\leadsto \color{blue}{\frac{{\ell}^{\left(e^{w}\right)}}{e^{w}}} \]
  4. Step-by-step derivation
    1. *-un-lft-identity99.6%

      \[\leadsto \frac{\color{blue}{1 \cdot {\ell}^{\left(e^{w}\right)}}}{e^{w}} \]
    2. add-cube-cbrt99.6%

      \[\leadsto \frac{1 \cdot {\ell}^{\left(e^{w}\right)}}{\color{blue}{\left(\sqrt[3]{e^{w}} \cdot \sqrt[3]{e^{w}}\right) \cdot \sqrt[3]{e^{w}}}} \]
    3. times-frac99.6%

      \[\leadsto \color{blue}{\frac{1}{\sqrt[3]{e^{w}} \cdot \sqrt[3]{e^{w}}} \cdot \frac{{\ell}^{\left(e^{w}\right)}}{\sqrt[3]{e^{w}}}} \]
    4. cbrt-unprod99.6%

      \[\leadsto \frac{1}{\color{blue}{\sqrt[3]{e^{w} \cdot e^{w}}}} \cdot \frac{{\ell}^{\left(e^{w}\right)}}{\sqrt[3]{e^{w}}} \]
    5. prod-exp99.6%

      \[\leadsto \frac{1}{\sqrt[3]{\color{blue}{e^{w + w}}}} \cdot \frac{{\ell}^{\left(e^{w}\right)}}{\sqrt[3]{e^{w}}} \]
  5. Applied egg-rr99.6%

    \[\leadsto \color{blue}{\frac{1}{\sqrt[3]{e^{w + w}}} \cdot \frac{{\ell}^{\left(e^{w}\right)}}{\sqrt[3]{e^{w}}}} \]
  6. Final simplification99.6%

    \[\leadsto \frac{1}{\sqrt[3]{e^{w + w}}} \cdot \frac{{\ell}^{\left(e^{w}\right)}}{\sqrt[3]{e^{w}}} \]

Alternative 2: 99.5% accurate, 0.6× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := e^{w \cdot -0.3333333333333333}\\ {\ell}^{\left(e^{w}\right)} \cdot \left(t_0 \cdot {t_0}^{2}\right) \end{array} \end{array} \]
(FPCore (w l)
 :precision binary64
 (let* ((t_0 (exp (* w -0.3333333333333333))))
   (* (pow l (exp w)) (* t_0 (pow t_0 2.0)))))
double code(double w, double l) {
	double t_0 = exp((w * -0.3333333333333333));
	return pow(l, exp(w)) * (t_0 * pow(t_0, 2.0));
}
real(8) function code(w, l)
    real(8), intent (in) :: w
    real(8), intent (in) :: l
    real(8) :: t_0
    t_0 = exp((w * (-0.3333333333333333d0)))
    code = (l ** exp(w)) * (t_0 * (t_0 ** 2.0d0))
end function
public static double code(double w, double l) {
	double t_0 = Math.exp((w * -0.3333333333333333));
	return Math.pow(l, Math.exp(w)) * (t_0 * Math.pow(t_0, 2.0));
}
def code(w, l):
	t_0 = math.exp((w * -0.3333333333333333))
	return math.pow(l, math.exp(w)) * (t_0 * math.pow(t_0, 2.0))
function code(w, l)
	t_0 = exp(Float64(w * -0.3333333333333333))
	return Float64((l ^ exp(w)) * Float64(t_0 * (t_0 ^ 2.0)))
end
function tmp = code(w, l)
	t_0 = exp((w * -0.3333333333333333));
	tmp = (l ^ exp(w)) * (t_0 * (t_0 ^ 2.0));
end
code[w_, l_] := Block[{t$95$0 = N[Exp[N[(w * -0.3333333333333333), $MachinePrecision]], $MachinePrecision]}, N[(N[Power[l, N[Exp[w], $MachinePrecision]], $MachinePrecision] * N[(t$95$0 * N[Power[t$95$0, 2.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := e^{w \cdot -0.3333333333333333}\\
{\ell}^{\left(e^{w}\right)} \cdot \left(t_0 \cdot {t_0}^{2}\right)
\end{array}
\end{array}
Derivation
  1. Initial program 99.6%

    \[e^{-w} \cdot {\ell}^{\left(e^{w}\right)} \]
  2. Step-by-step derivation
    1. exp-neg99.6%

      \[\leadsto \color{blue}{\frac{1}{e^{w}}} \cdot {\ell}^{\left(e^{w}\right)} \]
    2. associate-*l/99.6%

      \[\leadsto \color{blue}{\frac{1 \cdot {\ell}^{\left(e^{w}\right)}}{e^{w}}} \]
    3. *-lft-identity99.6%

      \[\leadsto \frac{\color{blue}{{\ell}^{\left(e^{w}\right)}}}{e^{w}} \]
  3. Simplified99.6%

    \[\leadsto \color{blue}{\frac{{\ell}^{\left(e^{w}\right)}}{e^{w}}} \]
  4. Taylor expanded in l around 0 94.3%

    \[\leadsto \frac{\color{blue}{e^{\log \ell \cdot e^{w}}}}{e^{w}} \]
  5. Step-by-step derivation
    1. pow-to-exp99.6%

      \[\leadsto \frac{\color{blue}{{\ell}^{\left(e^{w}\right)}}}{e^{w}} \]
    2. add-cbrt-cube99.6%

      \[\leadsto \frac{{\ell}^{\left(e^{w}\right)}}{\color{blue}{\sqrt[3]{\left(e^{w} \cdot e^{w}\right) \cdot e^{w}}}} \]
    3. exp-sum99.6%

      \[\leadsto \frac{{\ell}^{\left(e^{w}\right)}}{\sqrt[3]{\color{blue}{e^{w + w}} \cdot e^{w}}} \]
    4. cbrt-prod99.6%

      \[\leadsto \frac{{\ell}^{\left(e^{w}\right)}}{\color{blue}{\sqrt[3]{e^{w + w}} \cdot \sqrt[3]{e^{w}}}} \]
    5. associate-/l/99.6%

      \[\leadsto \color{blue}{\frac{\frac{{\ell}^{\left(e^{w}\right)}}{\sqrt[3]{e^{w}}}}{\sqrt[3]{e^{w + w}}}} \]
    6. div-inv99.6%

      \[\leadsto \color{blue}{\frac{{\ell}^{\left(e^{w}\right)}}{\sqrt[3]{e^{w}}} \cdot \frac{1}{\sqrt[3]{e^{w + w}}}} \]
    7. div-inv99.6%

      \[\leadsto \color{blue}{\left({\ell}^{\left(e^{w}\right)} \cdot \frac{1}{\sqrt[3]{e^{w}}}\right)} \cdot \frac{1}{\sqrt[3]{e^{w + w}}} \]
    8. associate-*l*99.6%

      \[\leadsto \color{blue}{{\ell}^{\left(e^{w}\right)} \cdot \left(\frac{1}{\sqrt[3]{e^{w}}} \cdot \frac{1}{\sqrt[3]{e^{w + w}}}\right)} \]
    9. add-exp-log99.6%

      \[\leadsto {\ell}^{\left(e^{w}\right)} \cdot \left(\frac{1}{\color{blue}{e^{\log \left(\sqrt[3]{e^{w}}\right)}}} \cdot \frac{1}{\sqrt[3]{e^{w + w}}}\right) \]
    10. rec-exp99.6%

      \[\leadsto {\ell}^{\left(e^{w}\right)} \cdot \left(\color{blue}{e^{-\log \left(\sqrt[3]{e^{w}}\right)}} \cdot \frac{1}{\sqrt[3]{e^{w + w}}}\right) \]
    11. pow1/399.6%

      \[\leadsto {\ell}^{\left(e^{w}\right)} \cdot \left(e^{-\log \color{blue}{\left({\left(e^{w}\right)}^{0.3333333333333333}\right)}} \cdot \frac{1}{\sqrt[3]{e^{w + w}}}\right) \]
    12. log-pow99.6%

      \[\leadsto {\ell}^{\left(e^{w}\right)} \cdot \left(e^{-\color{blue}{0.3333333333333333 \cdot \log \left(e^{w}\right)}} \cdot \frac{1}{\sqrt[3]{e^{w + w}}}\right) \]
    13. add-log-exp99.6%

      \[\leadsto {\ell}^{\left(e^{w}\right)} \cdot \left(e^{-0.3333333333333333 \cdot \color{blue}{w}} \cdot \frac{1}{\sqrt[3]{e^{w + w}}}\right) \]
  6. Applied egg-rr99.6%

    \[\leadsto \color{blue}{{\ell}^{\left(e^{w}\right)} \cdot \left(e^{-0.3333333333333333 \cdot w} \cdot {\left(e^{-0.3333333333333333 \cdot w}\right)}^{2}\right)} \]
  7. Taylor expanded in w around -inf 99.6%

    \[\leadsto {\ell}^{\left(e^{w}\right)} \cdot \left(e^{-0.3333333333333333 \cdot w} \cdot \color{blue}{{\left(e^{-0.3333333333333333 \cdot w}\right)}^{2}}\right) \]
  8. Step-by-step derivation
    1. *-commutative99.6%

      \[\leadsto {\ell}^{\left(e^{w}\right)} \cdot \left(e^{-0.3333333333333333 \cdot w} \cdot {\left(e^{\color{blue}{w \cdot -0.3333333333333333}}\right)}^{2}\right) \]
  9. Simplified99.6%

    \[\leadsto {\ell}^{\left(e^{w}\right)} \cdot \left(e^{-0.3333333333333333 \cdot w} \cdot \color{blue}{{\left(e^{w \cdot -0.3333333333333333}\right)}^{2}}\right) \]
  10. Taylor expanded in w around -inf 99.6%

    \[\leadsto {\ell}^{\left(e^{w}\right)} \cdot \left(\color{blue}{e^{-0.3333333333333333 \cdot w}} \cdot {\left(e^{w \cdot -0.3333333333333333}\right)}^{2}\right) \]
  11. Final simplification99.6%

    \[\leadsto {\ell}^{\left(e^{w}\right)} \cdot \left(e^{w \cdot -0.3333333333333333} \cdot {\left(e^{w \cdot -0.3333333333333333}\right)}^{2}\right) \]

Alternative 3: 99.4% accurate, 0.7× speedup?

\[\begin{array}{l} \\ {\ell}^{\left(e^{w}\right)} \cdot \sqrt[3]{e^{w \cdot \left(-3\right)}} \end{array} \]
(FPCore (w l)
 :precision binary64
 (* (pow l (exp w)) (cbrt (exp (* w (- 3.0))))))
double code(double w, double l) {
	return pow(l, exp(w)) * cbrt(exp((w * -3.0)));
}
public static double code(double w, double l) {
	return Math.pow(l, Math.exp(w)) * Math.cbrt(Math.exp((w * -3.0)));
}
function code(w, l)
	return Float64((l ^ exp(w)) * cbrt(exp(Float64(w * Float64(-3.0)))))
end
code[w_, l_] := N[(N[Power[l, N[Exp[w], $MachinePrecision]], $MachinePrecision] * N[Power[N[Exp[N[(w * (-3.0)), $MachinePrecision]], $MachinePrecision], 1/3], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
{\ell}^{\left(e^{w}\right)} \cdot \sqrt[3]{e^{w \cdot \left(-3\right)}}
\end{array}
Derivation
  1. Initial program 99.6%

    \[e^{-w} \cdot {\ell}^{\left(e^{w}\right)} \]
  2. Step-by-step derivation
    1. exp-neg99.6%

      \[\leadsto \color{blue}{\frac{1}{e^{w}}} \cdot {\ell}^{\left(e^{w}\right)} \]
    2. associate-*l/99.6%

      \[\leadsto \color{blue}{\frac{1 \cdot {\ell}^{\left(e^{w}\right)}}{e^{w}}} \]
    3. *-lft-identity99.6%

      \[\leadsto \frac{\color{blue}{{\ell}^{\left(e^{w}\right)}}}{e^{w}} \]
  3. Simplified99.6%

    \[\leadsto \color{blue}{\frac{{\ell}^{\left(e^{w}\right)}}{e^{w}}} \]
  4. Step-by-step derivation
    1. *-un-lft-identity99.6%

      \[\leadsto \frac{\color{blue}{1 \cdot {\ell}^{\left(e^{w}\right)}}}{e^{w}} \]
    2. add-cube-cbrt99.6%

      \[\leadsto \frac{1 \cdot {\ell}^{\left(e^{w}\right)}}{\color{blue}{\left(\sqrt[3]{e^{w}} \cdot \sqrt[3]{e^{w}}\right) \cdot \sqrt[3]{e^{w}}}} \]
    3. times-frac99.6%

      \[\leadsto \color{blue}{\frac{1}{\sqrt[3]{e^{w}} \cdot \sqrt[3]{e^{w}}} \cdot \frac{{\ell}^{\left(e^{w}\right)}}{\sqrt[3]{e^{w}}}} \]
    4. cbrt-unprod99.6%

      \[\leadsto \frac{1}{\color{blue}{\sqrt[3]{e^{w} \cdot e^{w}}}} \cdot \frac{{\ell}^{\left(e^{w}\right)}}{\sqrt[3]{e^{w}}} \]
    5. prod-exp99.6%

      \[\leadsto \frac{1}{\sqrt[3]{\color{blue}{e^{w + w}}}} \cdot \frac{{\ell}^{\left(e^{w}\right)}}{\sqrt[3]{e^{w}}} \]
  5. Applied egg-rr99.6%

    \[\leadsto \color{blue}{\frac{1}{\sqrt[3]{e^{w + w}}} \cdot \frac{{\ell}^{\left(e^{w}\right)}}{\sqrt[3]{e^{w}}}} \]
  6. Taylor expanded in w around inf 99.6%

    \[\leadsto \color{blue}{{\ell}^{\left(e^{w}\right)} \cdot {\left(\frac{1}{e^{2 \cdot w} \cdot e^{w}}\right)}^{0.3333333333333333}} \]
  7. Step-by-step derivation
    1. metadata-eval99.6%

      \[\leadsto {\ell}^{\left(e^{w}\right)} \cdot {\left(\frac{1}{e^{\color{blue}{\left(--2\right)} \cdot w} \cdot e^{w}}\right)}^{0.3333333333333333} \]
    2. distribute-lft-neg-in99.6%

      \[\leadsto {\ell}^{\left(e^{w}\right)} \cdot {\left(\frac{1}{e^{\color{blue}{--2 \cdot w}} \cdot e^{w}}\right)}^{0.3333333333333333} \]
    3. unpow1/399.6%

      \[\leadsto {\ell}^{\left(e^{w}\right)} \cdot \color{blue}{\sqrt[3]{\frac{1}{e^{--2 \cdot w} \cdot e^{w}}}} \]
    4. prod-exp99.6%

      \[\leadsto {\ell}^{\left(e^{w}\right)} \cdot \sqrt[3]{\frac{1}{\color{blue}{e^{\left(--2 \cdot w\right) + w}}}} \]
    5. distribute-lft-neg-in99.6%

      \[\leadsto {\ell}^{\left(e^{w}\right)} \cdot \sqrt[3]{\frac{1}{e^{\color{blue}{\left(--2\right) \cdot w} + w}}} \]
    6. metadata-eval99.6%

      \[\leadsto {\ell}^{\left(e^{w}\right)} \cdot \sqrt[3]{\frac{1}{e^{\color{blue}{2} \cdot w + w}}} \]
    7. rec-exp99.6%

      \[\leadsto {\ell}^{\left(e^{w}\right)} \cdot \sqrt[3]{\color{blue}{e^{-\left(2 \cdot w + w\right)}}} \]
    8. distribute-lft1-in99.6%

      \[\leadsto {\ell}^{\left(e^{w}\right)} \cdot \sqrt[3]{e^{-\color{blue}{\left(2 + 1\right) \cdot w}}} \]
    9. metadata-eval99.6%

      \[\leadsto {\ell}^{\left(e^{w}\right)} \cdot \sqrt[3]{e^{-\color{blue}{3} \cdot w}} \]
  8. Simplified99.6%

    \[\leadsto \color{blue}{{\ell}^{\left(e^{w}\right)} \cdot \sqrt[3]{e^{-3 \cdot w}}} \]
  9. Final simplification99.6%

    \[\leadsto {\ell}^{\left(e^{w}\right)} \cdot \sqrt[3]{e^{w \cdot \left(-3\right)}} \]

Alternative 4: 99.5% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \frac{{\ell}^{\left(e^{w}\right)}}{e^{w}} \end{array} \]
(FPCore (w l) :precision binary64 (/ (pow l (exp w)) (exp w)))
double code(double w, double l) {
	return pow(l, exp(w)) / exp(w);
}
real(8) function code(w, l)
    real(8), intent (in) :: w
    real(8), intent (in) :: l
    code = (l ** exp(w)) / exp(w)
end function
public static double code(double w, double l) {
	return Math.pow(l, Math.exp(w)) / Math.exp(w);
}
def code(w, l):
	return math.pow(l, math.exp(w)) / math.exp(w)
function code(w, l)
	return Float64((l ^ exp(w)) / exp(w))
end
function tmp = code(w, l)
	tmp = (l ^ exp(w)) / exp(w);
end
code[w_, l_] := N[(N[Power[l, N[Exp[w], $MachinePrecision]], $MachinePrecision] / N[Exp[w], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{{\ell}^{\left(e^{w}\right)}}{e^{w}}
\end{array}
Derivation
  1. Initial program 99.6%

    \[e^{-w} \cdot {\ell}^{\left(e^{w}\right)} \]
  2. Step-by-step derivation
    1. exp-neg99.6%

      \[\leadsto \color{blue}{\frac{1}{e^{w}}} \cdot {\ell}^{\left(e^{w}\right)} \]
    2. associate-*l/99.6%

      \[\leadsto \color{blue}{\frac{1 \cdot {\ell}^{\left(e^{w}\right)}}{e^{w}}} \]
    3. *-lft-identity99.6%

      \[\leadsto \frac{\color{blue}{{\ell}^{\left(e^{w}\right)}}}{e^{w}} \]
  3. Simplified99.6%

    \[\leadsto \color{blue}{\frac{{\ell}^{\left(e^{w}\right)}}{e^{w}}} \]
  4. Final simplification99.6%

    \[\leadsto \frac{{\ell}^{\left(e^{w}\right)}}{e^{w}} \]

Alternative 5: 97.8% accurate, 3.0× speedup?

\[\begin{array}{l} \\ \frac{\ell}{e^{w}} \end{array} \]
(FPCore (w l) :precision binary64 (/ l (exp w)))
double code(double w, double l) {
	return l / exp(w);
}
real(8) function code(w, l)
    real(8), intent (in) :: w
    real(8), intent (in) :: l
    code = l / exp(w)
end function
public static double code(double w, double l) {
	return l / Math.exp(w);
}
def code(w, l):
	return l / math.exp(w)
function code(w, l)
	return Float64(l / exp(w))
end
function tmp = code(w, l)
	tmp = l / exp(w);
end
code[w_, l_] := N[(l / N[Exp[w], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{\ell}{e^{w}}
\end{array}
Derivation
  1. Initial program 99.6%

    \[e^{-w} \cdot {\ell}^{\left(e^{w}\right)} \]
  2. Step-by-step derivation
    1. exp-neg99.6%

      \[\leadsto \color{blue}{\frac{1}{e^{w}}} \cdot {\ell}^{\left(e^{w}\right)} \]
    2. associate-*l/99.6%

      \[\leadsto \color{blue}{\frac{1 \cdot {\ell}^{\left(e^{w}\right)}}{e^{w}}} \]
    3. *-lft-identity99.6%

      \[\leadsto \frac{\color{blue}{{\ell}^{\left(e^{w}\right)}}}{e^{w}} \]
  3. Simplified99.6%

    \[\leadsto \color{blue}{\frac{{\ell}^{\left(e^{w}\right)}}{e^{w}}} \]
  4. Taylor expanded in w around 0 97.3%

    \[\leadsto \frac{\color{blue}{\ell}}{e^{w}} \]
  5. Final simplification97.3%

    \[\leadsto \frac{\ell}{e^{w}} \]

Alternative 6: 63.8% accurate, 61.0× speedup?

\[\begin{array}{l} \\ \ell - w \cdot \ell \end{array} \]
(FPCore (w l) :precision binary64 (- l (* w l)))
double code(double w, double l) {
	return l - (w * l);
}
real(8) function code(w, l)
    real(8), intent (in) :: w
    real(8), intent (in) :: l
    code = l - (w * l)
end function
public static double code(double w, double l) {
	return l - (w * l);
}
def code(w, l):
	return l - (w * l)
function code(w, l)
	return Float64(l - Float64(w * l))
end
function tmp = code(w, l)
	tmp = l - (w * l);
end
code[w_, l_] := N[(l - N[(w * l), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\ell - w \cdot \ell
\end{array}
Derivation
  1. Initial program 99.6%

    \[e^{-w} \cdot {\ell}^{\left(e^{w}\right)} \]
  2. Step-by-step derivation
    1. exp-neg99.6%

      \[\leadsto \color{blue}{\frac{1}{e^{w}}} \cdot {\ell}^{\left(e^{w}\right)} \]
    2. associate-*l/99.6%

      \[\leadsto \color{blue}{\frac{1 \cdot {\ell}^{\left(e^{w}\right)}}{e^{w}}} \]
    3. *-lft-identity99.6%

      \[\leadsto \frac{\color{blue}{{\ell}^{\left(e^{w}\right)}}}{e^{w}} \]
  3. Simplified99.6%

    \[\leadsto \color{blue}{\frac{{\ell}^{\left(e^{w}\right)}}{e^{w}}} \]
  4. Taylor expanded in w around 0 97.3%

    \[\leadsto \frac{\color{blue}{\ell}}{e^{w}} \]
  5. Taylor expanded in w around 0 67.2%

    \[\leadsto \color{blue}{-1 \cdot \left(\ell \cdot w\right) + \ell} \]
  6. Step-by-step derivation
    1. +-commutative67.2%

      \[\leadsto \color{blue}{\ell + -1 \cdot \left(\ell \cdot w\right)} \]
    2. mul-1-neg67.2%

      \[\leadsto \ell + \color{blue}{\left(-\ell \cdot w\right)} \]
    3. unsub-neg67.2%

      \[\leadsto \color{blue}{\ell - \ell \cdot w} \]
    4. *-commutative67.2%

      \[\leadsto \ell - \color{blue}{w \cdot \ell} \]
  7. Simplified67.2%

    \[\leadsto \color{blue}{\ell - w \cdot \ell} \]
  8. Final simplification67.2%

    \[\leadsto \ell - w \cdot \ell \]

Alternative 7: 57.3% accurate, 305.0× speedup?

\[\begin{array}{l} \\ \ell \end{array} \]
(FPCore (w l) :precision binary64 l)
double code(double w, double l) {
	return l;
}
real(8) function code(w, l)
    real(8), intent (in) :: w
    real(8), intent (in) :: l
    code = l
end function
public static double code(double w, double l) {
	return l;
}
def code(w, l):
	return l
function code(w, l)
	return l
end
function tmp = code(w, l)
	tmp = l;
end
code[w_, l_] := l
\begin{array}{l}

\\
\ell
\end{array}
Derivation
  1. Initial program 99.6%

    \[e^{-w} \cdot {\ell}^{\left(e^{w}\right)} \]
  2. Step-by-step derivation
    1. exp-neg99.6%

      \[\leadsto \color{blue}{\frac{1}{e^{w}}} \cdot {\ell}^{\left(e^{w}\right)} \]
    2. associate-*l/99.6%

      \[\leadsto \color{blue}{\frac{1 \cdot {\ell}^{\left(e^{w}\right)}}{e^{w}}} \]
    3. *-lft-identity99.6%

      \[\leadsto \frac{\color{blue}{{\ell}^{\left(e^{w}\right)}}}{e^{w}} \]
  3. Simplified99.6%

    \[\leadsto \color{blue}{\frac{{\ell}^{\left(e^{w}\right)}}{e^{w}}} \]
  4. Step-by-step derivation
    1. *-un-lft-identity99.6%

      \[\leadsto \frac{\color{blue}{1 \cdot {\ell}^{\left(e^{w}\right)}}}{e^{w}} \]
    2. add-cube-cbrt99.6%

      \[\leadsto \frac{1 \cdot {\ell}^{\left(e^{w}\right)}}{\color{blue}{\left(\sqrt[3]{e^{w}} \cdot \sqrt[3]{e^{w}}\right) \cdot \sqrt[3]{e^{w}}}} \]
    3. times-frac99.6%

      \[\leadsto \color{blue}{\frac{1}{\sqrt[3]{e^{w}} \cdot \sqrt[3]{e^{w}}} \cdot \frac{{\ell}^{\left(e^{w}\right)}}{\sqrt[3]{e^{w}}}} \]
    4. cbrt-unprod99.6%

      \[\leadsto \frac{1}{\color{blue}{\sqrt[3]{e^{w} \cdot e^{w}}}} \cdot \frac{{\ell}^{\left(e^{w}\right)}}{\sqrt[3]{e^{w}}} \]
    5. prod-exp99.6%

      \[\leadsto \frac{1}{\sqrt[3]{\color{blue}{e^{w + w}}}} \cdot \frac{{\ell}^{\left(e^{w}\right)}}{\sqrt[3]{e^{w}}} \]
  5. Applied egg-rr99.6%

    \[\leadsto \color{blue}{\frac{1}{\sqrt[3]{e^{w + w}}} \cdot \frac{{\ell}^{\left(e^{w}\right)}}{\sqrt[3]{e^{w}}}} \]
  6. Taylor expanded in w around 0 61.7%

    \[\leadsto \color{blue}{\ell} \]
  7. Final simplification61.7%

    \[\leadsto \ell \]

Reproduce

?
herbie shell --seed 2023203 
(FPCore (w l)
  :name "exp-w (used to crash)"
  :precision binary64
  (* (exp (- w)) (pow l (exp w))))