Numeric.SpecFunctions.Extra:bd0 from math-functions-0.1.5.2

Percentage Accurate: 78.3% → 99.7%
Time: 7.6s
Alternatives: 9
Speedup: 0.5×

Specification

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

\\
x \cdot \log \left(\frac{x}{y}\right) - z
\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 9 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: 78.3% accurate, 1.0× speedup?

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

\\
x \cdot \log \left(\frac{x}{y}\right) - z
\end{array}

Alternative 1: 99.7% accurate, 0.3× speedup?

\[\begin{array}{l} \\ x \cdot \left(3 \cdot \log \left(\frac{\sqrt[3]{x}}{\sqrt[3]{y}}\right)\right) - z \end{array} \]
(FPCore (x y z)
 :precision binary64
 (- (* x (* 3.0 (log (/ (cbrt x) (cbrt y))))) z))
double code(double x, double y, double z) {
	return (x * (3.0 * log((cbrt(x) / cbrt(y))))) - z;
}
public static double code(double x, double y, double z) {
	return (x * (3.0 * Math.log((Math.cbrt(x) / Math.cbrt(y))))) - z;
}
function code(x, y, z)
	return Float64(Float64(x * Float64(3.0 * log(Float64(cbrt(x) / cbrt(y))))) - z)
end
code[x_, y_, z_] := N[(N[(x * N[(3.0 * N[Log[N[(N[Power[x, 1/3], $MachinePrecision] / N[Power[y, 1/3], $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] - z), $MachinePrecision]
\begin{array}{l}

\\
x \cdot \left(3 \cdot \log \left(\frac{\sqrt[3]{x}}{\sqrt[3]{y}}\right)\right) - z
\end{array}
Derivation
  1. Initial program 73.9%

    \[x \cdot \log \left(\frac{x}{y}\right) - z \]
  2. Step-by-step derivation
    1. add-cube-cbrt73.9%

      \[\leadsto x \cdot \log \color{blue}{\left(\left(\sqrt[3]{\frac{x}{y}} \cdot \sqrt[3]{\frac{x}{y}}\right) \cdot \sqrt[3]{\frac{x}{y}}\right)} - z \]
    2. log-prod73.9%

      \[\leadsto x \cdot \color{blue}{\left(\log \left(\sqrt[3]{\frac{x}{y}} \cdot \sqrt[3]{\frac{x}{y}}\right) + \log \left(\sqrt[3]{\frac{x}{y}}\right)\right)} - z \]
    3. pow273.9%

      \[\leadsto x \cdot \left(\log \color{blue}{\left({\left(\sqrt[3]{\frac{x}{y}}\right)}^{2}\right)} + \log \left(\sqrt[3]{\frac{x}{y}}\right)\right) - z \]
  3. Applied egg-rr73.9%

    \[\leadsto x \cdot \color{blue}{\left(\log \left({\left(\sqrt[3]{\frac{x}{y}}\right)}^{2}\right) + \log \left(\sqrt[3]{\frac{x}{y}}\right)\right)} - z \]
  4. Step-by-step derivation
    1. log-pow73.9%

      \[\leadsto x \cdot \left(\color{blue}{2 \cdot \log \left(\sqrt[3]{\frac{x}{y}}\right)} + \log \left(\sqrt[3]{\frac{x}{y}}\right)\right) - z \]
    2. distribute-lft1-in73.9%

      \[\leadsto x \cdot \color{blue}{\left(\left(2 + 1\right) \cdot \log \left(\sqrt[3]{\frac{x}{y}}\right)\right)} - z \]
    3. metadata-eval73.9%

      \[\leadsto x \cdot \left(\color{blue}{3} \cdot \log \left(\sqrt[3]{\frac{x}{y}}\right)\right) - z \]
  5. Simplified73.9%

    \[\leadsto x \cdot \color{blue}{\left(3 \cdot \log \left(\sqrt[3]{\frac{x}{y}}\right)\right)} - z \]
  6. Step-by-step derivation
    1. cbrt-div99.7%

      \[\leadsto x \cdot \left(3 \cdot \log \color{blue}{\left(\frac{\sqrt[3]{x}}{\sqrt[3]{y}}\right)}\right) - z \]
    2. div-inv99.7%

      \[\leadsto x \cdot \left(3 \cdot \log \color{blue}{\left(\sqrt[3]{x} \cdot \frac{1}{\sqrt[3]{y}}\right)}\right) - z \]
  7. Applied egg-rr99.7%

    \[\leadsto x \cdot \left(3 \cdot \log \color{blue}{\left(\sqrt[3]{x} \cdot \frac{1}{\sqrt[3]{y}}\right)}\right) - z \]
  8. Step-by-step derivation
    1. associate-*r/99.7%

      \[\leadsto x \cdot \left(3 \cdot \log \color{blue}{\left(\frac{\sqrt[3]{x} \cdot 1}{\sqrt[3]{y}}\right)}\right) - z \]
    2. *-rgt-identity99.7%

      \[\leadsto x \cdot \left(3 \cdot \log \left(\frac{\color{blue}{\sqrt[3]{x}}}{\sqrt[3]{y}}\right)\right) - z \]
  9. Simplified99.7%

    \[\leadsto x \cdot \left(3 \cdot \log \color{blue}{\left(\frac{\sqrt[3]{x}}{\sqrt[3]{y}}\right)}\right) - z \]
  10. Final simplification99.7%

    \[\leadsto x \cdot \left(3 \cdot \log \left(\frac{\sqrt[3]{x}}{\sqrt[3]{y}}\right)\right) - z \]

Alternative 2: 86.6% accurate, 0.3× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := x \cdot \log \left(\frac{x}{y}\right)\\ \mathbf{if}\;t_0 \leq -\infty \lor \neg \left(t_0 \leq 5 \cdot 10^{+294}\right):\\ \;\;\;\;-z\\ \mathbf{else}:\\ \;\;\;\;-\mathsf{fma}\left(x, \log \left(\frac{y}{x}\right), z\right)\\ \end{array} \end{array} \]
(FPCore (x y z)
 :precision binary64
 (let* ((t_0 (* x (log (/ x y)))))
   (if (or (<= t_0 (- INFINITY)) (not (<= t_0 5e+294)))
     (- z)
     (- (fma x (log (/ y x)) z)))))
double code(double x, double y, double z) {
	double t_0 = x * log((x / y));
	double tmp;
	if ((t_0 <= -((double) INFINITY)) || !(t_0 <= 5e+294)) {
		tmp = -z;
	} else {
		tmp = -fma(x, log((y / x)), z);
	}
	return tmp;
}
function code(x, y, z)
	t_0 = Float64(x * log(Float64(x / y)))
	tmp = 0.0
	if ((t_0 <= Float64(-Inf)) || !(t_0 <= 5e+294))
		tmp = Float64(-z);
	else
		tmp = Float64(-fma(x, log(Float64(y / x)), z));
	end
	return tmp
end
code[x_, y_, z_] := Block[{t$95$0 = N[(x * N[Log[N[(x / y), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]}, If[Or[LessEqual[t$95$0, (-Infinity)], N[Not[LessEqual[t$95$0, 5e+294]], $MachinePrecision]], (-z), (-N[(x * N[Log[N[(y / x), $MachinePrecision]], $MachinePrecision] + z), $MachinePrecision])]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := x \cdot \log \left(\frac{x}{y}\right)\\
\mathbf{if}\;t_0 \leq -\infty \lor \neg \left(t_0 \leq 5 \cdot 10^{+294}\right):\\
\;\;\;\;-z\\

\mathbf{else}:\\
\;\;\;\;-\mathsf{fma}\left(x, \log \left(\frac{y}{x}\right), z\right)\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (*.f64 x (log.f64 (/.f64 x y))) < -inf.0 or 4.9999999999999999e294 < (*.f64 x (log.f64 (/.f64 x y)))

    1. Initial program 6.6%

      \[x \cdot \log \left(\frac{x}{y}\right) - z \]
    2. Step-by-step derivation
      1. remove-double-neg6.6%

        \[\leadsto \color{blue}{-\left(-\left(x \cdot \log \left(\frac{x}{y}\right) - z\right)\right)} \]
      2. sub0-neg6.6%

        \[\leadsto -\color{blue}{\left(0 - \left(x \cdot \log \left(\frac{x}{y}\right) - z\right)\right)} \]
      3. associate--r-6.6%

        \[\leadsto -\color{blue}{\left(\left(0 - x \cdot \log \left(\frac{x}{y}\right)\right) + z\right)} \]
      4. neg-sub06.6%

        \[\leadsto -\left(\color{blue}{\left(-x \cdot \log \left(\frac{x}{y}\right)\right)} + z\right) \]
      5. distribute-rgt-neg-in6.6%

        \[\leadsto -\left(\color{blue}{x \cdot \left(-\log \left(\frac{x}{y}\right)\right)} + z\right) \]
      6. neg-sub06.6%

        \[\leadsto -\left(x \cdot \color{blue}{\left(0 - \log \left(\frac{x}{y}\right)\right)} + z\right) \]
      7. log-div43.6%

        \[\leadsto -\left(x \cdot \left(0 - \color{blue}{\left(\log x - \log y\right)}\right) + z\right) \]
      8. associate-+l-43.6%

        \[\leadsto -\left(x \cdot \color{blue}{\left(\left(0 - \log x\right) + \log y\right)} + z\right) \]
      9. neg-sub043.6%

        \[\leadsto -\left(x \cdot \left(\color{blue}{\left(-\log x\right)} + \log y\right) + z\right) \]
      10. +-commutative43.6%

        \[\leadsto -\left(x \cdot \color{blue}{\left(\log y + \left(-\log x\right)\right)} + z\right) \]
      11. sub-neg43.6%

        \[\leadsto -\left(x \cdot \color{blue}{\left(\log y - \log x\right)} + z\right) \]
      12. log-div12.0%

        \[\leadsto -\left(x \cdot \color{blue}{\log \left(\frac{y}{x}\right)} + z\right) \]
      13. fma-udef12.0%

        \[\leadsto -\color{blue}{\mathsf{fma}\left(x, \log \left(\frac{y}{x}\right), z\right)} \]
    3. Simplified12.0%

      \[\leadsto \color{blue}{-\mathsf{fma}\left(x, \log \left(\frac{y}{x}\right), z\right)} \]
    4. Taylor expanded in x around 0 45.4%

      \[\leadsto -\color{blue}{z} \]

    if -inf.0 < (*.f64 x (log.f64 (/.f64 x y))) < 4.9999999999999999e294

    1. Initial program 99.8%

      \[x \cdot \log \left(\frac{x}{y}\right) - z \]
    2. Step-by-step derivation
      1. remove-double-neg99.8%

        \[\leadsto \color{blue}{-\left(-\left(x \cdot \log \left(\frac{x}{y}\right) - z\right)\right)} \]
      2. sub0-neg99.8%

        \[\leadsto -\color{blue}{\left(0 - \left(x \cdot \log \left(\frac{x}{y}\right) - z\right)\right)} \]
      3. associate--r-99.8%

        \[\leadsto -\color{blue}{\left(\left(0 - x \cdot \log \left(\frac{x}{y}\right)\right) + z\right)} \]
      4. neg-sub099.8%

        \[\leadsto -\left(\color{blue}{\left(-x \cdot \log \left(\frac{x}{y}\right)\right)} + z\right) \]
      5. distribute-rgt-neg-in99.8%

        \[\leadsto -\left(\color{blue}{x \cdot \left(-\log \left(\frac{x}{y}\right)\right)} + z\right) \]
      6. neg-sub099.8%

        \[\leadsto -\left(x \cdot \color{blue}{\left(0 - \log \left(\frac{x}{y}\right)\right)} + z\right) \]
      7. log-div45.7%

        \[\leadsto -\left(x \cdot \left(0 - \color{blue}{\left(\log x - \log y\right)}\right) + z\right) \]
      8. associate-+l-45.7%

        \[\leadsto -\left(x \cdot \color{blue}{\left(\left(0 - \log x\right) + \log y\right)} + z\right) \]
      9. neg-sub045.7%

        \[\leadsto -\left(x \cdot \left(\color{blue}{\left(-\log x\right)} + \log y\right) + z\right) \]
      10. +-commutative45.7%

        \[\leadsto -\left(x \cdot \color{blue}{\left(\log y + \left(-\log x\right)\right)} + z\right) \]
      11. sub-neg45.7%

        \[\leadsto -\left(x \cdot \color{blue}{\left(\log y - \log x\right)} + z\right) \]
      12. log-div99.8%

        \[\leadsto -\left(x \cdot \color{blue}{\log \left(\frac{y}{x}\right)} + z\right) \]
      13. fma-udef99.8%

        \[\leadsto -\color{blue}{\mathsf{fma}\left(x, \log \left(\frac{y}{x}\right), z\right)} \]
    3. Simplified99.8%

      \[\leadsto \color{blue}{-\mathsf{fma}\left(x, \log \left(\frac{y}{x}\right), z\right)} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification84.7%

    \[\leadsto \begin{array}{l} \mathbf{if}\;x \cdot \log \left(\frac{x}{y}\right) \leq -\infty \lor \neg \left(x \cdot \log \left(\frac{x}{y}\right) \leq 5 \cdot 10^{+294}\right):\\ \;\;\;\;-z\\ \mathbf{else}:\\ \;\;\;\;-\mathsf{fma}\left(x, \log \left(\frac{y}{x}\right), z\right)\\ \end{array} \]

Alternative 3: 87.5% accurate, 0.3× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := x \cdot \log \left(\frac{x}{y}\right)\\ \mathbf{if}\;t_0 \leq -\infty \lor \neg \left(t_0 \leq 5 \cdot 10^{+294}\right):\\ \;\;\;\;-z\\ \mathbf{else}:\\ \;\;\;\;t_0 - z\\ \end{array} \end{array} \]
(FPCore (x y z)
 :precision binary64
 (let* ((t_0 (* x (log (/ x y)))))
   (if (or (<= t_0 (- INFINITY)) (not (<= t_0 5e+294))) (- z) (- t_0 z))))
double code(double x, double y, double z) {
	double t_0 = x * log((x / y));
	double tmp;
	if ((t_0 <= -((double) INFINITY)) || !(t_0 <= 5e+294)) {
		tmp = -z;
	} else {
		tmp = t_0 - z;
	}
	return tmp;
}
public static double code(double x, double y, double z) {
	double t_0 = x * Math.log((x / y));
	double tmp;
	if ((t_0 <= -Double.POSITIVE_INFINITY) || !(t_0 <= 5e+294)) {
		tmp = -z;
	} else {
		tmp = t_0 - z;
	}
	return tmp;
}
def code(x, y, z):
	t_0 = x * math.log((x / y))
	tmp = 0
	if (t_0 <= -math.inf) or not (t_0 <= 5e+294):
		tmp = -z
	else:
		tmp = t_0 - z
	return tmp
function code(x, y, z)
	t_0 = Float64(x * log(Float64(x / y)))
	tmp = 0.0
	if ((t_0 <= Float64(-Inf)) || !(t_0 <= 5e+294))
		tmp = Float64(-z);
	else
		tmp = Float64(t_0 - z);
	end
	return tmp
end
function tmp_2 = code(x, y, z)
	t_0 = x * log((x / y));
	tmp = 0.0;
	if ((t_0 <= -Inf) || ~((t_0 <= 5e+294)))
		tmp = -z;
	else
		tmp = t_0 - z;
	end
	tmp_2 = tmp;
end
code[x_, y_, z_] := Block[{t$95$0 = N[(x * N[Log[N[(x / y), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]}, If[Or[LessEqual[t$95$0, (-Infinity)], N[Not[LessEqual[t$95$0, 5e+294]], $MachinePrecision]], (-z), N[(t$95$0 - z), $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := x \cdot \log \left(\frac{x}{y}\right)\\
\mathbf{if}\;t_0 \leq -\infty \lor \neg \left(t_0 \leq 5 \cdot 10^{+294}\right):\\
\;\;\;\;-z\\

\mathbf{else}:\\
\;\;\;\;t_0 - z\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (*.f64 x (log.f64 (/.f64 x y))) < -inf.0 or 4.9999999999999999e294 < (*.f64 x (log.f64 (/.f64 x y)))

    1. Initial program 6.6%

      \[x \cdot \log \left(\frac{x}{y}\right) - z \]
    2. Step-by-step derivation
      1. remove-double-neg6.6%

        \[\leadsto \color{blue}{-\left(-\left(x \cdot \log \left(\frac{x}{y}\right) - z\right)\right)} \]
      2. sub0-neg6.6%

        \[\leadsto -\color{blue}{\left(0 - \left(x \cdot \log \left(\frac{x}{y}\right) - z\right)\right)} \]
      3. associate--r-6.6%

        \[\leadsto -\color{blue}{\left(\left(0 - x \cdot \log \left(\frac{x}{y}\right)\right) + z\right)} \]
      4. neg-sub06.6%

        \[\leadsto -\left(\color{blue}{\left(-x \cdot \log \left(\frac{x}{y}\right)\right)} + z\right) \]
      5. distribute-rgt-neg-in6.6%

        \[\leadsto -\left(\color{blue}{x \cdot \left(-\log \left(\frac{x}{y}\right)\right)} + z\right) \]
      6. neg-sub06.6%

        \[\leadsto -\left(x \cdot \color{blue}{\left(0 - \log \left(\frac{x}{y}\right)\right)} + z\right) \]
      7. log-div43.6%

        \[\leadsto -\left(x \cdot \left(0 - \color{blue}{\left(\log x - \log y\right)}\right) + z\right) \]
      8. associate-+l-43.6%

        \[\leadsto -\left(x \cdot \color{blue}{\left(\left(0 - \log x\right) + \log y\right)} + z\right) \]
      9. neg-sub043.6%

        \[\leadsto -\left(x \cdot \left(\color{blue}{\left(-\log x\right)} + \log y\right) + z\right) \]
      10. +-commutative43.6%

        \[\leadsto -\left(x \cdot \color{blue}{\left(\log y + \left(-\log x\right)\right)} + z\right) \]
      11. sub-neg43.6%

        \[\leadsto -\left(x \cdot \color{blue}{\left(\log y - \log x\right)} + z\right) \]
      12. log-div12.0%

        \[\leadsto -\left(x \cdot \color{blue}{\log \left(\frac{y}{x}\right)} + z\right) \]
      13. fma-udef12.0%

        \[\leadsto -\color{blue}{\mathsf{fma}\left(x, \log \left(\frac{y}{x}\right), z\right)} \]
    3. Simplified12.0%

      \[\leadsto \color{blue}{-\mathsf{fma}\left(x, \log \left(\frac{y}{x}\right), z\right)} \]
    4. Taylor expanded in x around 0 45.4%

      \[\leadsto -\color{blue}{z} \]

    if -inf.0 < (*.f64 x (log.f64 (/.f64 x y))) < 4.9999999999999999e294

    1. Initial program 99.8%

      \[x \cdot \log \left(\frac{x}{y}\right) - z \]
  3. Recombined 2 regimes into one program.
  4. Final simplification84.7%

    \[\leadsto \begin{array}{l} \mathbf{if}\;x \cdot \log \left(\frac{x}{y}\right) \leq -\infty \lor \neg \left(x \cdot \log \left(\frac{x}{y}\right) \leq 5 \cdot 10^{+294}\right):\\ \;\;\;\;-z\\ \mathbf{else}:\\ \;\;\;\;x \cdot \log \left(\frac{x}{y}\right) - z\\ \end{array} \]

Alternative 4: 87.7% accurate, 0.5× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq -9 \cdot 10^{+184}:\\ \;\;\;\;x \cdot \left(\log \left(-x\right) - \log \left(-y\right)\right)\\ \mathbf{elif}\;x \leq -2.1 \cdot 10^{-209}:\\ \;\;\;\;-\mathsf{fma}\left(x, \log \left(\frac{y}{x}\right), z\right)\\ \mathbf{elif}\;x \leq 5.2 \cdot 10^{-210}:\\ \;\;\;\;-z\\ \mathbf{elif}\;x \leq 8.2 \cdot 10^{+176}:\\ \;\;\;\;x \cdot \log \left(\frac{x}{y}\right) - z\\ \mathbf{else}:\\ \;\;\;\;x \cdot \left(\log x - \log y\right)\\ \end{array} \end{array} \]
(FPCore (x y z)
 :precision binary64
 (if (<= x -9e+184)
   (* x (- (log (- x)) (log (- y))))
   (if (<= x -2.1e-209)
     (- (fma x (log (/ y x)) z))
     (if (<= x 5.2e-210)
       (- z)
       (if (<= x 8.2e+176)
         (- (* x (log (/ x y))) z)
         (* x (- (log x) (log y))))))))
double code(double x, double y, double z) {
	double tmp;
	if (x <= -9e+184) {
		tmp = x * (log(-x) - log(-y));
	} else if (x <= -2.1e-209) {
		tmp = -fma(x, log((y / x)), z);
	} else if (x <= 5.2e-210) {
		tmp = -z;
	} else if (x <= 8.2e+176) {
		tmp = (x * log((x / y))) - z;
	} else {
		tmp = x * (log(x) - log(y));
	}
	return tmp;
}
function code(x, y, z)
	tmp = 0.0
	if (x <= -9e+184)
		tmp = Float64(x * Float64(log(Float64(-x)) - log(Float64(-y))));
	elseif (x <= -2.1e-209)
		tmp = Float64(-fma(x, log(Float64(y / x)), z));
	elseif (x <= 5.2e-210)
		tmp = Float64(-z);
	elseif (x <= 8.2e+176)
		tmp = Float64(Float64(x * log(Float64(x / y))) - z);
	else
		tmp = Float64(x * Float64(log(x) - log(y)));
	end
	return tmp
end
code[x_, y_, z_] := If[LessEqual[x, -9e+184], N[(x * N[(N[Log[(-x)], $MachinePrecision] - N[Log[(-y)], $MachinePrecision]), $MachinePrecision]), $MachinePrecision], If[LessEqual[x, -2.1e-209], (-N[(x * N[Log[N[(y / x), $MachinePrecision]], $MachinePrecision] + z), $MachinePrecision]), If[LessEqual[x, 5.2e-210], (-z), If[LessEqual[x, 8.2e+176], N[(N[(x * N[Log[N[(x / y), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] - z), $MachinePrecision], N[(x * N[(N[Log[x], $MachinePrecision] - N[Log[y], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]]]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;x \leq -9 \cdot 10^{+184}:\\
\;\;\;\;x \cdot \left(\log \left(-x\right) - \log \left(-y\right)\right)\\

\mathbf{elif}\;x \leq -2.1 \cdot 10^{-209}:\\
\;\;\;\;-\mathsf{fma}\left(x, \log \left(\frac{y}{x}\right), z\right)\\

\mathbf{elif}\;x \leq 5.2 \cdot 10^{-210}:\\
\;\;\;\;-z\\

\mathbf{elif}\;x \leq 8.2 \cdot 10^{+176}:\\
\;\;\;\;x \cdot \log \left(\frac{x}{y}\right) - z\\

\mathbf{else}:\\
\;\;\;\;x \cdot \left(\log x - \log y\right)\\


\end{array}
\end{array}
Derivation
  1. Split input into 5 regimes
  2. if x < -9.00000000000000072e184

    1. Initial program 53.6%

      \[x \cdot \log \left(\frac{x}{y}\right) - z \]
    2. Taylor expanded in z around 0 53.6%

      \[\leadsto \color{blue}{x \cdot \log \left(\frac{x}{y}\right)} \]
    3. Step-by-step derivation
      1. frac-2neg53.6%

        \[\leadsto x \cdot \log \color{blue}{\left(\frac{-x}{-y}\right)} \]
      2. log-div90.3%

        \[\leadsto x \cdot \color{blue}{\left(\log \left(-x\right) - \log \left(-y\right)\right)} \]
    4. Applied egg-rr90.3%

      \[\leadsto x \cdot \color{blue}{\left(\log \left(-x\right) - \log \left(-y\right)\right)} \]

    if -9.00000000000000072e184 < x < -2.09999999999999996e-209

    1. Initial program 82.1%

      \[x \cdot \log \left(\frac{x}{y}\right) - z \]
    2. Step-by-step derivation
      1. remove-double-neg82.1%

        \[\leadsto \color{blue}{-\left(-\left(x \cdot \log \left(\frac{x}{y}\right) - z\right)\right)} \]
      2. sub0-neg82.1%

        \[\leadsto -\color{blue}{\left(0 - \left(x \cdot \log \left(\frac{x}{y}\right) - z\right)\right)} \]
      3. associate--r-82.1%

        \[\leadsto -\color{blue}{\left(\left(0 - x \cdot \log \left(\frac{x}{y}\right)\right) + z\right)} \]
      4. neg-sub082.1%

        \[\leadsto -\left(\color{blue}{\left(-x \cdot \log \left(\frac{x}{y}\right)\right)} + z\right) \]
      5. distribute-rgt-neg-in82.1%

        \[\leadsto -\left(\color{blue}{x \cdot \left(-\log \left(\frac{x}{y}\right)\right)} + z\right) \]
      6. neg-sub082.1%

        \[\leadsto -\left(x \cdot \color{blue}{\left(0 - \log \left(\frac{x}{y}\right)\right)} + z\right) \]
      7. log-div0.0%

        \[\leadsto -\left(x \cdot \left(0 - \color{blue}{\left(\log x - \log y\right)}\right) + z\right) \]
      8. associate-+l-0.0%

        \[\leadsto -\left(x \cdot \color{blue}{\left(\left(0 - \log x\right) + \log y\right)} + z\right) \]
      9. neg-sub00.0%

        \[\leadsto -\left(x \cdot \left(\color{blue}{\left(-\log x\right)} + \log y\right) + z\right) \]
      10. +-commutative0.0%

        \[\leadsto -\left(x \cdot \color{blue}{\left(\log y + \left(-\log x\right)\right)} + z\right) \]
      11. sub-neg0.0%

        \[\leadsto -\left(x \cdot \color{blue}{\left(\log y - \log x\right)} + z\right) \]
      12. log-div85.2%

        \[\leadsto -\left(x \cdot \color{blue}{\log \left(\frac{y}{x}\right)} + z\right) \]
      13. fma-udef85.2%

        \[\leadsto -\color{blue}{\mathsf{fma}\left(x, \log \left(\frac{y}{x}\right), z\right)} \]
    3. Simplified85.2%

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

    if -2.09999999999999996e-209 < x < 5.1999999999999997e-210

    1. Initial program 44.4%

      \[x \cdot \log \left(\frac{x}{y}\right) - z \]
    2. Step-by-step derivation
      1. remove-double-neg44.4%

        \[\leadsto \color{blue}{-\left(-\left(x \cdot \log \left(\frac{x}{y}\right) - z\right)\right)} \]
      2. sub0-neg44.4%

        \[\leadsto -\color{blue}{\left(0 - \left(x \cdot \log \left(\frac{x}{y}\right) - z\right)\right)} \]
      3. associate--r-44.4%

        \[\leadsto -\color{blue}{\left(\left(0 - x \cdot \log \left(\frac{x}{y}\right)\right) + z\right)} \]
      4. neg-sub044.4%

        \[\leadsto -\left(\color{blue}{\left(-x \cdot \log \left(\frac{x}{y}\right)\right)} + z\right) \]
      5. distribute-rgt-neg-in44.4%

        \[\leadsto -\left(\color{blue}{x \cdot \left(-\log \left(\frac{x}{y}\right)\right)} + z\right) \]
      6. neg-sub044.4%

        \[\leadsto -\left(x \cdot \color{blue}{\left(0 - \log \left(\frac{x}{y}\right)\right)} + z\right) \]
      7. log-div40.5%

        \[\leadsto -\left(x \cdot \left(0 - \color{blue}{\left(\log x - \log y\right)}\right) + z\right) \]
      8. associate-+l-40.5%

        \[\leadsto -\left(x \cdot \color{blue}{\left(\left(0 - \log x\right) + \log y\right)} + z\right) \]
      9. neg-sub040.5%

        \[\leadsto -\left(x \cdot \left(\color{blue}{\left(-\log x\right)} + \log y\right) + z\right) \]
      10. +-commutative40.5%

        \[\leadsto -\left(x \cdot \color{blue}{\left(\log y + \left(-\log x\right)\right)} + z\right) \]
      11. sub-neg40.5%

        \[\leadsto -\left(x \cdot \color{blue}{\left(\log y - \log x\right)} + z\right) \]
      12. log-div44.4%

        \[\leadsto -\left(x \cdot \color{blue}{\log \left(\frac{y}{x}\right)} + z\right) \]
      13. fma-udef44.4%

        \[\leadsto -\color{blue}{\mathsf{fma}\left(x, \log \left(\frac{y}{x}\right), z\right)} \]
    3. Simplified44.4%

      \[\leadsto \color{blue}{-\mathsf{fma}\left(x, \log \left(\frac{y}{x}\right), z\right)} \]
    4. Taylor expanded in x around 0 91.3%

      \[\leadsto -\color{blue}{z} \]

    if 5.1999999999999997e-210 < x < 8.1999999999999998e176

    1. Initial program 89.6%

      \[x \cdot \log \left(\frac{x}{y}\right) - z \]

    if 8.1999999999999998e176 < x

    1. Initial program 60.0%

      \[x \cdot \log \left(\frac{x}{y}\right) - z \]
    2. Taylor expanded in z around 0 52.6%

      \[\leadsto \color{blue}{x \cdot \log \left(\frac{x}{y}\right)} \]
    3. Step-by-step derivation
      1. log-div91.7%

        \[\leadsto x \cdot \color{blue}{\left(\log x - \log y\right)} \]
    4. Applied egg-rr91.7%

      \[\leadsto x \cdot \color{blue}{\left(\log x - \log y\right)} \]
  3. Recombined 5 regimes into one program.
  4. Final simplification88.5%

    \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq -9 \cdot 10^{+184}:\\ \;\;\;\;x \cdot \left(\log \left(-x\right) - \log \left(-y\right)\right)\\ \mathbf{elif}\;x \leq -2.1 \cdot 10^{-209}:\\ \;\;\;\;-\mathsf{fma}\left(x, \log \left(\frac{y}{x}\right), z\right)\\ \mathbf{elif}\;x \leq 5.2 \cdot 10^{-210}:\\ \;\;\;\;-z\\ \mathbf{elif}\;x \leq 8.2 \cdot 10^{+176}:\\ \;\;\;\;x \cdot \log \left(\frac{x}{y}\right) - z\\ \mathbf{else}:\\ \;\;\;\;x \cdot \left(\log x - \log y\right)\\ \end{array} \]

Alternative 5: 93.3% accurate, 0.5× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq -9 \cdot 10^{+180}:\\ \;\;\;\;x \cdot \left(\log \left(-x\right) - \log \left(-y\right)\right)\\ \mathbf{elif}\;x \leq -4.5 \cdot 10^{-212}:\\ \;\;\;\;-\mathsf{fma}\left(x, \log \left(\frac{y}{x}\right), z\right)\\ \mathbf{elif}\;x \leq -2 \cdot 10^{-308}:\\ \;\;\;\;-z\\ \mathbf{else}:\\ \;\;\;\;x \cdot \left(\log x - \log y\right) - z\\ \end{array} \end{array} \]
(FPCore (x y z)
 :precision binary64
 (if (<= x -9e+180)
   (* x (- (log (- x)) (log (- y))))
   (if (<= x -4.5e-212)
     (- (fma x (log (/ y x)) z))
     (if (<= x -2e-308) (- z) (- (* x (- (log x) (log y))) z)))))
double code(double x, double y, double z) {
	double tmp;
	if (x <= -9e+180) {
		tmp = x * (log(-x) - log(-y));
	} else if (x <= -4.5e-212) {
		tmp = -fma(x, log((y / x)), z);
	} else if (x <= -2e-308) {
		tmp = -z;
	} else {
		tmp = (x * (log(x) - log(y))) - z;
	}
	return tmp;
}
function code(x, y, z)
	tmp = 0.0
	if (x <= -9e+180)
		tmp = Float64(x * Float64(log(Float64(-x)) - log(Float64(-y))));
	elseif (x <= -4.5e-212)
		tmp = Float64(-fma(x, log(Float64(y / x)), z));
	elseif (x <= -2e-308)
		tmp = Float64(-z);
	else
		tmp = Float64(Float64(x * Float64(log(x) - log(y))) - z);
	end
	return tmp
end
code[x_, y_, z_] := If[LessEqual[x, -9e+180], N[(x * N[(N[Log[(-x)], $MachinePrecision] - N[Log[(-y)], $MachinePrecision]), $MachinePrecision]), $MachinePrecision], If[LessEqual[x, -4.5e-212], (-N[(x * N[Log[N[(y / x), $MachinePrecision]], $MachinePrecision] + z), $MachinePrecision]), If[LessEqual[x, -2e-308], (-z), N[(N[(x * N[(N[Log[x], $MachinePrecision] - N[Log[y], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] - z), $MachinePrecision]]]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;x \leq -9 \cdot 10^{+180}:\\
\;\;\;\;x \cdot \left(\log \left(-x\right) - \log \left(-y\right)\right)\\

\mathbf{elif}\;x \leq -4.5 \cdot 10^{-212}:\\
\;\;\;\;-\mathsf{fma}\left(x, \log \left(\frac{y}{x}\right), z\right)\\

\mathbf{elif}\;x \leq -2 \cdot 10^{-308}:\\
\;\;\;\;-z\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 4 regimes
  2. if x < -8.99999999999999962e180

    1. Initial program 53.6%

      \[x \cdot \log \left(\frac{x}{y}\right) - z \]
    2. Taylor expanded in z around 0 53.6%

      \[\leadsto \color{blue}{x \cdot \log \left(\frac{x}{y}\right)} \]
    3. Step-by-step derivation
      1. frac-2neg53.6%

        \[\leadsto x \cdot \log \color{blue}{\left(\frac{-x}{-y}\right)} \]
      2. log-div90.3%

        \[\leadsto x \cdot \color{blue}{\left(\log \left(-x\right) - \log \left(-y\right)\right)} \]
    4. Applied egg-rr90.3%

      \[\leadsto x \cdot \color{blue}{\left(\log \left(-x\right) - \log \left(-y\right)\right)} \]

    if -8.99999999999999962e180 < x < -4.4999999999999999e-212

    1. Initial program 82.1%

      \[x \cdot \log \left(\frac{x}{y}\right) - z \]
    2. Step-by-step derivation
      1. remove-double-neg82.1%

        \[\leadsto \color{blue}{-\left(-\left(x \cdot \log \left(\frac{x}{y}\right) - z\right)\right)} \]
      2. sub0-neg82.1%

        \[\leadsto -\color{blue}{\left(0 - \left(x \cdot \log \left(\frac{x}{y}\right) - z\right)\right)} \]
      3. associate--r-82.1%

        \[\leadsto -\color{blue}{\left(\left(0 - x \cdot \log \left(\frac{x}{y}\right)\right) + z\right)} \]
      4. neg-sub082.1%

        \[\leadsto -\left(\color{blue}{\left(-x \cdot \log \left(\frac{x}{y}\right)\right)} + z\right) \]
      5. distribute-rgt-neg-in82.1%

        \[\leadsto -\left(\color{blue}{x \cdot \left(-\log \left(\frac{x}{y}\right)\right)} + z\right) \]
      6. neg-sub082.1%

        \[\leadsto -\left(x \cdot \color{blue}{\left(0 - \log \left(\frac{x}{y}\right)\right)} + z\right) \]
      7. log-div0.0%

        \[\leadsto -\left(x \cdot \left(0 - \color{blue}{\left(\log x - \log y\right)}\right) + z\right) \]
      8. associate-+l-0.0%

        \[\leadsto -\left(x \cdot \color{blue}{\left(\left(0 - \log x\right) + \log y\right)} + z\right) \]
      9. neg-sub00.0%

        \[\leadsto -\left(x \cdot \left(\color{blue}{\left(-\log x\right)} + \log y\right) + z\right) \]
      10. +-commutative0.0%

        \[\leadsto -\left(x \cdot \color{blue}{\left(\log y + \left(-\log x\right)\right)} + z\right) \]
      11. sub-neg0.0%

        \[\leadsto -\left(x \cdot \color{blue}{\left(\log y - \log x\right)} + z\right) \]
      12. log-div85.2%

        \[\leadsto -\left(x \cdot \color{blue}{\log \left(\frac{y}{x}\right)} + z\right) \]
      13. fma-udef85.2%

        \[\leadsto -\color{blue}{\mathsf{fma}\left(x, \log \left(\frac{y}{x}\right), z\right)} \]
    3. Simplified85.2%

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

    if -4.4999999999999999e-212 < x < -1.9999999999999998e-308

    1. Initial program 55.1%

      \[x \cdot \log \left(\frac{x}{y}\right) - z \]
    2. Step-by-step derivation
      1. remove-double-neg55.1%

        \[\leadsto \color{blue}{-\left(-\left(x \cdot \log \left(\frac{x}{y}\right) - z\right)\right)} \]
      2. sub0-neg55.1%

        \[\leadsto -\color{blue}{\left(0 - \left(x \cdot \log \left(\frac{x}{y}\right) - z\right)\right)} \]
      3. associate--r-55.1%

        \[\leadsto -\color{blue}{\left(\left(0 - x \cdot \log \left(\frac{x}{y}\right)\right) + z\right)} \]
      4. neg-sub055.1%

        \[\leadsto -\left(\color{blue}{\left(-x \cdot \log \left(\frac{x}{y}\right)\right)} + z\right) \]
      5. distribute-rgt-neg-in55.1%

        \[\leadsto -\left(\color{blue}{x \cdot \left(-\log \left(\frac{x}{y}\right)\right)} + z\right) \]
      6. neg-sub055.1%

        \[\leadsto -\left(x \cdot \color{blue}{\left(0 - \log \left(\frac{x}{y}\right)\right)} + z\right) \]
      7. log-div0.0%

        \[\leadsto -\left(x \cdot \left(0 - \color{blue}{\left(\log x - \log y\right)}\right) + z\right) \]
      8. associate-+l-0.0%

        \[\leadsto -\left(x \cdot \color{blue}{\left(\left(0 - \log x\right) + \log y\right)} + z\right) \]
      9. neg-sub00.0%

        \[\leadsto -\left(x \cdot \left(\color{blue}{\left(-\log x\right)} + \log y\right) + z\right) \]
      10. +-commutative0.0%

        \[\leadsto -\left(x \cdot \color{blue}{\left(\log y + \left(-\log x\right)\right)} + z\right) \]
      11. sub-neg0.0%

        \[\leadsto -\left(x \cdot \color{blue}{\left(\log y - \log x\right)} + z\right) \]
      12. log-div55.1%

        \[\leadsto -\left(x \cdot \color{blue}{\log \left(\frac{y}{x}\right)} + z\right) \]
      13. fma-udef55.1%

        \[\leadsto -\color{blue}{\mathsf{fma}\left(x, \log \left(\frac{y}{x}\right), z\right)} \]
    3. Simplified55.1%

      \[\leadsto \color{blue}{-\mathsf{fma}\left(x, \log \left(\frac{y}{x}\right), z\right)} \]
    4. Taylor expanded in x around 0 89.5%

      \[\leadsto -\color{blue}{z} \]

    if -1.9999999999999998e-308 < x

    1. Initial program 75.1%

      \[x \cdot \log \left(\frac{x}{y}\right) - z \]
    2. Step-by-step derivation
      1. log-div46.9%

        \[\leadsto x \cdot \color{blue}{\left(\log x - \log y\right)} \]
    3. Applied egg-rr99.6%

      \[\leadsto x \cdot \color{blue}{\left(\log x - \log y\right)} - z \]
  3. Recombined 4 regimes into one program.
  4. Final simplification92.6%

    \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq -9 \cdot 10^{+180}:\\ \;\;\;\;x \cdot \left(\log \left(-x\right) - \log \left(-y\right)\right)\\ \mathbf{elif}\;x \leq -4.5 \cdot 10^{-212}:\\ \;\;\;\;-\mathsf{fma}\left(x, \log \left(\frac{y}{x}\right), z\right)\\ \mathbf{elif}\;x \leq -2 \cdot 10^{-308}:\\ \;\;\;\;-z\\ \mathbf{else}:\\ \;\;\;\;x \cdot \left(\log x - \log y\right) - z\\ \end{array} \]

Alternative 6: 99.5% accurate, 0.5× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;y \leq -5 \cdot 10^{-310}:\\ \;\;\;\;x \cdot \left(\log \left(-x\right) - \log \left(-y\right)\right) - z\\ \mathbf{else}:\\ \;\;\;\;x \cdot \left(\log x - \log y\right) - z\\ \end{array} \end{array} \]
(FPCore (x y z)
 :precision binary64
 (if (<= y -5e-310)
   (- (* x (- (log (- x)) (log (- y)))) z)
   (- (* x (- (log x) (log y))) z)))
double code(double x, double y, double z) {
	double tmp;
	if (y <= -5e-310) {
		tmp = (x * (log(-x) - log(-y))) - z;
	} else {
		tmp = (x * (log(x) - log(y))) - z;
	}
	return tmp;
}
real(8) function code(x, y, z)
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    real(8), intent (in) :: z
    real(8) :: tmp
    if (y <= (-5d-310)) then
        tmp = (x * (log(-x) - log(-y))) - z
    else
        tmp = (x * (log(x) - log(y))) - z
    end if
    code = tmp
end function
public static double code(double x, double y, double z) {
	double tmp;
	if (y <= -5e-310) {
		tmp = (x * (Math.log(-x) - Math.log(-y))) - z;
	} else {
		tmp = (x * (Math.log(x) - Math.log(y))) - z;
	}
	return tmp;
}
def code(x, y, z):
	tmp = 0
	if y <= -5e-310:
		tmp = (x * (math.log(-x) - math.log(-y))) - z
	else:
		tmp = (x * (math.log(x) - math.log(y))) - z
	return tmp
function code(x, y, z)
	tmp = 0.0
	if (y <= -5e-310)
		tmp = Float64(Float64(x * Float64(log(Float64(-x)) - log(Float64(-y)))) - z);
	else
		tmp = Float64(Float64(x * Float64(log(x) - log(y))) - z);
	end
	return tmp
end
function tmp_2 = code(x, y, z)
	tmp = 0.0;
	if (y <= -5e-310)
		tmp = (x * (log(-x) - log(-y))) - z;
	else
		tmp = (x * (log(x) - log(y))) - z;
	end
	tmp_2 = tmp;
end
code[x_, y_, z_] := If[LessEqual[y, -5e-310], N[(N[(x * N[(N[Log[(-x)], $MachinePrecision] - N[Log[(-y)], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] - z), $MachinePrecision], N[(N[(x * N[(N[Log[x], $MachinePrecision] - N[Log[y], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] - z), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;y \leq -5 \cdot 10^{-310}:\\
\;\;\;\;x \cdot \left(\log \left(-x\right) - \log \left(-y\right)\right) - z\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if y < -4.999999999999985e-310

    1. Initial program 73.0%

      \[x \cdot \log \left(\frac{x}{y}\right) - z \]
    2. Step-by-step derivation
      1. frac-2neg39.1%

        \[\leadsto x \cdot \log \color{blue}{\left(\frac{-x}{-y}\right)} \]
      2. log-div52.2%

        \[\leadsto x \cdot \color{blue}{\left(\log \left(-x\right) - \log \left(-y\right)\right)} \]
    3. Applied egg-rr99.6%

      \[\leadsto x \cdot \color{blue}{\left(\log \left(-x\right) - \log \left(-y\right)\right)} - z \]

    if -4.999999999999985e-310 < y

    1. Initial program 75.1%

      \[x \cdot \log \left(\frac{x}{y}\right) - z \]
    2. Step-by-step derivation
      1. log-div46.9%

        \[\leadsto x \cdot \color{blue}{\left(\log x - \log y\right)} \]
    3. Applied egg-rr99.6%

      \[\leadsto x \cdot \color{blue}{\left(\log x - \log y\right)} - z \]
  3. Recombined 2 regimes into one program.
  4. Final simplification99.6%

    \[\leadsto \begin{array}{l} \mathbf{if}\;y \leq -5 \cdot 10^{-310}:\\ \;\;\;\;x \cdot \left(\log \left(-x\right) - \log \left(-y\right)\right) - z\\ \mathbf{else}:\\ \;\;\;\;x \cdot \left(\log x - \log y\right) - z\\ \end{array} \]

Alternative 7: 67.7% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;z \leq -650000000000 \lor \neg \left(z \leq 125000\right):\\ \;\;\;\;-z\\ \mathbf{else}:\\ \;\;\;\;\left(-x\right) \cdot \log \left(\frac{y}{x}\right)\\ \end{array} \end{array} \]
(FPCore (x y z)
 :precision binary64
 (if (or (<= z -650000000000.0) (not (<= z 125000.0)))
   (- z)
   (* (- x) (log (/ y x)))))
double code(double x, double y, double z) {
	double tmp;
	if ((z <= -650000000000.0) || !(z <= 125000.0)) {
		tmp = -z;
	} else {
		tmp = -x * log((y / x));
	}
	return tmp;
}
real(8) function code(x, y, z)
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    real(8), intent (in) :: z
    real(8) :: tmp
    if ((z <= (-650000000000.0d0)) .or. (.not. (z <= 125000.0d0))) then
        tmp = -z
    else
        tmp = -x * log((y / x))
    end if
    code = tmp
end function
public static double code(double x, double y, double z) {
	double tmp;
	if ((z <= -650000000000.0) || !(z <= 125000.0)) {
		tmp = -z;
	} else {
		tmp = -x * Math.log((y / x));
	}
	return tmp;
}
def code(x, y, z):
	tmp = 0
	if (z <= -650000000000.0) or not (z <= 125000.0):
		tmp = -z
	else:
		tmp = -x * math.log((y / x))
	return tmp
function code(x, y, z)
	tmp = 0.0
	if ((z <= -650000000000.0) || !(z <= 125000.0))
		tmp = Float64(-z);
	else
		tmp = Float64(Float64(-x) * log(Float64(y / x)));
	end
	return tmp
end
function tmp_2 = code(x, y, z)
	tmp = 0.0;
	if ((z <= -650000000000.0) || ~((z <= 125000.0)))
		tmp = -z;
	else
		tmp = -x * log((y / x));
	end
	tmp_2 = tmp;
end
code[x_, y_, z_] := If[Or[LessEqual[z, -650000000000.0], N[Not[LessEqual[z, 125000.0]], $MachinePrecision]], (-z), N[((-x) * N[Log[N[(y / x), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;z \leq -650000000000 \lor \neg \left(z \leq 125000\right):\\
\;\;\;\;-z\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if z < -6.5e11 or 125000 < z

    1. Initial program 74.9%

      \[x \cdot \log \left(\frac{x}{y}\right) - z \]
    2. Step-by-step derivation
      1. remove-double-neg74.9%

        \[\leadsto \color{blue}{-\left(-\left(x \cdot \log \left(\frac{x}{y}\right) - z\right)\right)} \]
      2. sub0-neg74.9%

        \[\leadsto -\color{blue}{\left(0 - \left(x \cdot \log \left(\frac{x}{y}\right) - z\right)\right)} \]
      3. associate--r-74.9%

        \[\leadsto -\color{blue}{\left(\left(0 - x \cdot \log \left(\frac{x}{y}\right)\right) + z\right)} \]
      4. neg-sub074.9%

        \[\leadsto -\left(\color{blue}{\left(-x \cdot \log \left(\frac{x}{y}\right)\right)} + z\right) \]
      5. distribute-rgt-neg-in74.9%

        \[\leadsto -\left(\color{blue}{x \cdot \left(-\log \left(\frac{x}{y}\right)\right)} + z\right) \]
      6. neg-sub074.9%

        \[\leadsto -\left(x \cdot \color{blue}{\left(0 - \log \left(\frac{x}{y}\right)\right)} + z\right) \]
      7. log-div47.6%

        \[\leadsto -\left(x \cdot \left(0 - \color{blue}{\left(\log x - \log y\right)}\right) + z\right) \]
      8. associate-+l-47.6%

        \[\leadsto -\left(x \cdot \color{blue}{\left(\left(0 - \log x\right) + \log y\right)} + z\right) \]
      9. neg-sub047.6%

        \[\leadsto -\left(x \cdot \left(\color{blue}{\left(-\log x\right)} + \log y\right) + z\right) \]
      10. +-commutative47.6%

        \[\leadsto -\left(x \cdot \color{blue}{\left(\log y + \left(-\log x\right)\right)} + z\right) \]
      11. sub-neg47.6%

        \[\leadsto -\left(x \cdot \color{blue}{\left(\log y - \log x\right)} + z\right) \]
      12. log-div75.7%

        \[\leadsto -\left(x \cdot \color{blue}{\log \left(\frac{y}{x}\right)} + z\right) \]
      13. fma-udef75.7%

        \[\leadsto -\color{blue}{\mathsf{fma}\left(x, \log \left(\frac{y}{x}\right), z\right)} \]
    3. Simplified75.7%

      \[\leadsto \color{blue}{-\mathsf{fma}\left(x, \log \left(\frac{y}{x}\right), z\right)} \]
    4. Taylor expanded in x around 0 78.0%

      \[\leadsto -\color{blue}{z} \]

    if -6.5e11 < z < 125000

    1. Initial program 72.9%

      \[x \cdot \log \left(\frac{x}{y}\right) - z \]
    2. Step-by-step derivation
      1. remove-double-neg72.9%

        \[\leadsto \color{blue}{-\left(-\left(x \cdot \log \left(\frac{x}{y}\right) - z\right)\right)} \]
      2. sub0-neg72.9%

        \[\leadsto -\color{blue}{\left(0 - \left(x \cdot \log \left(\frac{x}{y}\right) - z\right)\right)} \]
      3. associate--r-72.9%

        \[\leadsto -\color{blue}{\left(\left(0 - x \cdot \log \left(\frac{x}{y}\right)\right) + z\right)} \]
      4. neg-sub072.9%

        \[\leadsto -\left(\color{blue}{\left(-x \cdot \log \left(\frac{x}{y}\right)\right)} + z\right) \]
      5. distribute-rgt-neg-in72.9%

        \[\leadsto -\left(\color{blue}{x \cdot \left(-\log \left(\frac{x}{y}\right)\right)} + z\right) \]
      6. neg-sub072.9%

        \[\leadsto -\left(x \cdot \color{blue}{\left(0 - \log \left(\frac{x}{y}\right)\right)} + z\right) \]
      7. log-div42.5%

        \[\leadsto -\left(x \cdot \left(0 - \color{blue}{\left(\log x - \log y\right)}\right) + z\right) \]
      8. associate-+l-42.5%

        \[\leadsto -\left(x \cdot \color{blue}{\left(\left(0 - \log x\right) + \log y\right)} + z\right) \]
      9. neg-sub042.5%

        \[\leadsto -\left(x \cdot \left(\color{blue}{\left(-\log x\right)} + \log y\right) + z\right) \]
      10. +-commutative42.5%

        \[\leadsto -\left(x \cdot \color{blue}{\left(\log y + \left(-\log x\right)\right)} + z\right) \]
      11. sub-neg42.5%

        \[\leadsto -\left(x \cdot \color{blue}{\left(\log y - \log x\right)} + z\right) \]
      12. log-div75.2%

        \[\leadsto -\left(x \cdot \color{blue}{\log \left(\frac{y}{x}\right)} + z\right) \]
      13. fma-udef75.2%

        \[\leadsto -\color{blue}{\mathsf{fma}\left(x, \log \left(\frac{y}{x}\right), z\right)} \]
    3. Simplified75.2%

      \[\leadsto \color{blue}{-\mathsf{fma}\left(x, \log \left(\frac{y}{x}\right), z\right)} \]
    4. Taylor expanded in x around inf 33.7%

      \[\leadsto -\color{blue}{x \cdot \left(\log y + \log \left(\frac{1}{x}\right)\right)} \]
    5. Step-by-step derivation
      1. log-rec33.7%

        \[\leadsto -x \cdot \left(\log y + \color{blue}{\left(-\log x\right)}\right) \]
      2. neg-mul-133.7%

        \[\leadsto -x \cdot \left(\log y + \color{blue}{-1 \cdot \log x}\right) \]
      3. neg-mul-133.7%

        \[\leadsto -x \cdot \left(\log y + \color{blue}{\left(-\log x\right)}\right) \]
      4. sub-neg33.7%

        \[\leadsto -x \cdot \color{blue}{\left(\log y - \log x\right)} \]
      5. log-div63.9%

        \[\leadsto -x \cdot \color{blue}{\log \left(\frac{y}{x}\right)} \]
    6. Simplified63.9%

      \[\leadsto -\color{blue}{x \cdot \log \left(\frac{y}{x}\right)} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification71.0%

    \[\leadsto \begin{array}{l} \mathbf{if}\;z \leq -650000000000 \lor \neg \left(z \leq 125000\right):\\ \;\;\;\;-z\\ \mathbf{else}:\\ \;\;\;\;\left(-x\right) \cdot \log \left(\frac{y}{x}\right)\\ \end{array} \]

Alternative 8: 67.4% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;z \leq -1650000000 \lor \neg \left(z \leq 47000000\right):\\ \;\;\;\;-z\\ \mathbf{else}:\\ \;\;\;\;x \cdot \log \left(\frac{x}{y}\right)\\ \end{array} \end{array} \]
(FPCore (x y z)
 :precision binary64
 (if (or (<= z -1650000000.0) (not (<= z 47000000.0)))
   (- z)
   (* x (log (/ x y)))))
double code(double x, double y, double z) {
	double tmp;
	if ((z <= -1650000000.0) || !(z <= 47000000.0)) {
		tmp = -z;
	} else {
		tmp = x * log((x / y));
	}
	return tmp;
}
real(8) function code(x, y, z)
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    real(8), intent (in) :: z
    real(8) :: tmp
    if ((z <= (-1650000000.0d0)) .or. (.not. (z <= 47000000.0d0))) then
        tmp = -z
    else
        tmp = x * log((x / y))
    end if
    code = tmp
end function
public static double code(double x, double y, double z) {
	double tmp;
	if ((z <= -1650000000.0) || !(z <= 47000000.0)) {
		tmp = -z;
	} else {
		tmp = x * Math.log((x / y));
	}
	return tmp;
}
def code(x, y, z):
	tmp = 0
	if (z <= -1650000000.0) or not (z <= 47000000.0):
		tmp = -z
	else:
		tmp = x * math.log((x / y))
	return tmp
function code(x, y, z)
	tmp = 0.0
	if ((z <= -1650000000.0) || !(z <= 47000000.0))
		tmp = Float64(-z);
	else
		tmp = Float64(x * log(Float64(x / y)));
	end
	return tmp
end
function tmp_2 = code(x, y, z)
	tmp = 0.0;
	if ((z <= -1650000000.0) || ~((z <= 47000000.0)))
		tmp = -z;
	else
		tmp = x * log((x / y));
	end
	tmp_2 = tmp;
end
code[x_, y_, z_] := If[Or[LessEqual[z, -1650000000.0], N[Not[LessEqual[z, 47000000.0]], $MachinePrecision]], (-z), N[(x * N[Log[N[(x / y), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;z \leq -1650000000 \lor \neg \left(z \leq 47000000\right):\\
\;\;\;\;-z\\

\mathbf{else}:\\
\;\;\;\;x \cdot \log \left(\frac{x}{y}\right)\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if z < -1.65e9 or 4.7e7 < z

    1. Initial program 74.9%

      \[x \cdot \log \left(\frac{x}{y}\right) - z \]
    2. Step-by-step derivation
      1. remove-double-neg74.9%

        \[\leadsto \color{blue}{-\left(-\left(x \cdot \log \left(\frac{x}{y}\right) - z\right)\right)} \]
      2. sub0-neg74.9%

        \[\leadsto -\color{blue}{\left(0 - \left(x \cdot \log \left(\frac{x}{y}\right) - z\right)\right)} \]
      3. associate--r-74.9%

        \[\leadsto -\color{blue}{\left(\left(0 - x \cdot \log \left(\frac{x}{y}\right)\right) + z\right)} \]
      4. neg-sub074.9%

        \[\leadsto -\left(\color{blue}{\left(-x \cdot \log \left(\frac{x}{y}\right)\right)} + z\right) \]
      5. distribute-rgt-neg-in74.9%

        \[\leadsto -\left(\color{blue}{x \cdot \left(-\log \left(\frac{x}{y}\right)\right)} + z\right) \]
      6. neg-sub074.9%

        \[\leadsto -\left(x \cdot \color{blue}{\left(0 - \log \left(\frac{x}{y}\right)\right)} + z\right) \]
      7. log-div47.6%

        \[\leadsto -\left(x \cdot \left(0 - \color{blue}{\left(\log x - \log y\right)}\right) + z\right) \]
      8. associate-+l-47.6%

        \[\leadsto -\left(x \cdot \color{blue}{\left(\left(0 - \log x\right) + \log y\right)} + z\right) \]
      9. neg-sub047.6%

        \[\leadsto -\left(x \cdot \left(\color{blue}{\left(-\log x\right)} + \log y\right) + z\right) \]
      10. +-commutative47.6%

        \[\leadsto -\left(x \cdot \color{blue}{\left(\log y + \left(-\log x\right)\right)} + z\right) \]
      11. sub-neg47.6%

        \[\leadsto -\left(x \cdot \color{blue}{\left(\log y - \log x\right)} + z\right) \]
      12. log-div75.7%

        \[\leadsto -\left(x \cdot \color{blue}{\log \left(\frac{y}{x}\right)} + z\right) \]
      13. fma-udef75.7%

        \[\leadsto -\color{blue}{\mathsf{fma}\left(x, \log \left(\frac{y}{x}\right), z\right)} \]
    3. Simplified75.7%

      \[\leadsto \color{blue}{-\mathsf{fma}\left(x, \log \left(\frac{y}{x}\right), z\right)} \]
    4. Taylor expanded in x around 0 78.0%

      \[\leadsto -\color{blue}{z} \]

    if -1.65e9 < z < 4.7e7

    1. Initial program 72.9%

      \[x \cdot \log \left(\frac{x}{y}\right) - z \]
    2. Taylor expanded in z around 0 61.6%

      \[\leadsto \color{blue}{x \cdot \log \left(\frac{x}{y}\right)} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification69.9%

    \[\leadsto \begin{array}{l} \mathbf{if}\;z \leq -1650000000 \lor \neg \left(z \leq 47000000\right):\\ \;\;\;\;-z\\ \mathbf{else}:\\ \;\;\;\;x \cdot \log \left(\frac{x}{y}\right)\\ \end{array} \]

Alternative 9: 49.7% accurate, 53.5× speedup?

\[\begin{array}{l} \\ -z \end{array} \]
(FPCore (x y z) :precision binary64 (- z))
double code(double x, double y, double z) {
	return -z;
}
real(8) function code(x, y, z)
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    real(8), intent (in) :: z
    code = -z
end function
public static double code(double x, double y, double z) {
	return -z;
}
def code(x, y, z):
	return -z
function code(x, y, z)
	return Float64(-z)
end
function tmp = code(x, y, z)
	tmp = -z;
end
code[x_, y_, z_] := (-z)
\begin{array}{l}

\\
-z
\end{array}
Derivation
  1. Initial program 73.9%

    \[x \cdot \log \left(\frac{x}{y}\right) - z \]
  2. Step-by-step derivation
    1. remove-double-neg73.9%

      \[\leadsto \color{blue}{-\left(-\left(x \cdot \log \left(\frac{x}{y}\right) - z\right)\right)} \]
    2. sub0-neg73.9%

      \[\leadsto -\color{blue}{\left(0 - \left(x \cdot \log \left(\frac{x}{y}\right) - z\right)\right)} \]
    3. associate--r-73.9%

      \[\leadsto -\color{blue}{\left(\left(0 - x \cdot \log \left(\frac{x}{y}\right)\right) + z\right)} \]
    4. neg-sub073.9%

      \[\leadsto -\left(\color{blue}{\left(-x \cdot \log \left(\frac{x}{y}\right)\right)} + z\right) \]
    5. distribute-rgt-neg-in73.9%

      \[\leadsto -\left(\color{blue}{x \cdot \left(-\log \left(\frac{x}{y}\right)\right)} + z\right) \]
    6. neg-sub073.9%

      \[\leadsto -\left(x \cdot \color{blue}{\left(0 - \log \left(\frac{x}{y}\right)\right)} + z\right) \]
    7. log-div45.1%

      \[\leadsto -\left(x \cdot \left(0 - \color{blue}{\left(\log x - \log y\right)}\right) + z\right) \]
    8. associate-+l-45.1%

      \[\leadsto -\left(x \cdot \color{blue}{\left(\left(0 - \log x\right) + \log y\right)} + z\right) \]
    9. neg-sub045.1%

      \[\leadsto -\left(x \cdot \left(\color{blue}{\left(-\log x\right)} + \log y\right) + z\right) \]
    10. +-commutative45.1%

      \[\leadsto -\left(x \cdot \color{blue}{\left(\log y + \left(-\log x\right)\right)} + z\right) \]
    11. sub-neg45.1%

      \[\leadsto -\left(x \cdot \color{blue}{\left(\log y - \log x\right)} + z\right) \]
    12. log-div75.4%

      \[\leadsto -\left(x \cdot \color{blue}{\log \left(\frac{y}{x}\right)} + z\right) \]
    13. fma-udef75.5%

      \[\leadsto -\color{blue}{\mathsf{fma}\left(x, \log \left(\frac{y}{x}\right), z\right)} \]
  3. Simplified75.5%

    \[\leadsto \color{blue}{-\mathsf{fma}\left(x, \log \left(\frac{y}{x}\right), z\right)} \]
  4. Taylor expanded in x around 0 50.4%

    \[\leadsto -\color{blue}{z} \]
  5. Final simplification50.4%

    \[\leadsto -z \]

Developer target: 88.9% accurate, 0.5× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;y < 7.595077799083773 \cdot 10^{-308}:\\ \;\;\;\;x \cdot \log \left(\frac{x}{y}\right) - z\\ \mathbf{else}:\\ \;\;\;\;x \cdot \left(\log x - \log y\right) - z\\ \end{array} \end{array} \]
(FPCore (x y z)
 :precision binary64
 (if (< y 7.595077799083773e-308)
   (- (* x (log (/ x y))) z)
   (- (* x (- (log x) (log y))) z)))
double code(double x, double y, double z) {
	double tmp;
	if (y < 7.595077799083773e-308) {
		tmp = (x * log((x / y))) - z;
	} else {
		tmp = (x * (log(x) - log(y))) - z;
	}
	return tmp;
}
real(8) function code(x, y, z)
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    real(8), intent (in) :: z
    real(8) :: tmp
    if (y < 7.595077799083773d-308) then
        tmp = (x * log((x / y))) - z
    else
        tmp = (x * (log(x) - log(y))) - z
    end if
    code = tmp
end function
public static double code(double x, double y, double z) {
	double tmp;
	if (y < 7.595077799083773e-308) {
		tmp = (x * Math.log((x / y))) - z;
	} else {
		tmp = (x * (Math.log(x) - Math.log(y))) - z;
	}
	return tmp;
}
def code(x, y, z):
	tmp = 0
	if y < 7.595077799083773e-308:
		tmp = (x * math.log((x / y))) - z
	else:
		tmp = (x * (math.log(x) - math.log(y))) - z
	return tmp
function code(x, y, z)
	tmp = 0.0
	if (y < 7.595077799083773e-308)
		tmp = Float64(Float64(x * log(Float64(x / y))) - z);
	else
		tmp = Float64(Float64(x * Float64(log(x) - log(y))) - z);
	end
	return tmp
end
function tmp_2 = code(x, y, z)
	tmp = 0.0;
	if (y < 7.595077799083773e-308)
		tmp = (x * log((x / y))) - z;
	else
		tmp = (x * (log(x) - log(y))) - z;
	end
	tmp_2 = tmp;
end
code[x_, y_, z_] := If[Less[y, 7.595077799083773e-308], N[(N[(x * N[Log[N[(x / y), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] - z), $MachinePrecision], N[(N[(x * N[(N[Log[x], $MachinePrecision] - N[Log[y], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] - z), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;y < 7.595077799083773 \cdot 10^{-308}:\\
\;\;\;\;x \cdot \log \left(\frac{x}{y}\right) - z\\

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


\end{array}
\end{array}

Reproduce

?
herbie shell --seed 2023336 
(FPCore (x y z)
  :name "Numeric.SpecFunctions.Extra:bd0 from math-functions-0.1.5.2"
  :precision binary64

  :herbie-target
  (if (< y 7.595077799083773e-308) (- (* x (log (/ x y))) z) (- (* x (- (log x) (log y))) z))

  (- (* x (log (/ x y))) z))