Numeric.SpecFunctions:stirlingError from math-functions-0.1.5.2

Percentage Accurate: 99.8% → 99.9%
Time: 9.0s
Alternatives: 11
Speedup: 1.0×

Specification

?
\[\begin{array}{l} \\ \left(\left(x - \left(y + 0.5\right) \cdot \log y\right) + y\right) - z \end{array} \]
(FPCore (x y z) :precision binary64 (- (+ (- x (* (+ y 0.5) (log y))) y) z))
double code(double x, double y, double z) {
	return ((x - ((y + 0.5) * log(y))) + 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 - ((y + 0.5d0) * log(y))) + y) - z
end function
public static double code(double x, double y, double z) {
	return ((x - ((y + 0.5) * Math.log(y))) + y) - z;
}
def code(x, y, z):
	return ((x - ((y + 0.5) * math.log(y))) + y) - z
function code(x, y, z)
	return Float64(Float64(Float64(x - Float64(Float64(y + 0.5) * log(y))) + y) - z)
end
function tmp = code(x, y, z)
	tmp = ((x - ((y + 0.5) * log(y))) + y) - z;
end
code[x_, y_, z_] := N[(N[(N[(x - N[(N[(y + 0.5), $MachinePrecision] * N[Log[y], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + y), $MachinePrecision] - z), $MachinePrecision]
\begin{array}{l}

\\
\left(\left(x - \left(y + 0.5\right) \cdot \log y\right) + 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 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: 99.8% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \left(\left(x - \left(y + 0.5\right) \cdot \log y\right) + y\right) - z \end{array} \]
(FPCore (x y z) :precision binary64 (- (+ (- x (* (+ y 0.5) (log y))) y) z))
double code(double x, double y, double z) {
	return ((x - ((y + 0.5) * log(y))) + 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 - ((y + 0.5d0) * log(y))) + y) - z
end function
public static double code(double x, double y, double z) {
	return ((x - ((y + 0.5) * Math.log(y))) + y) - z;
}
def code(x, y, z):
	return ((x - ((y + 0.5) * math.log(y))) + y) - z
function code(x, y, z)
	return Float64(Float64(Float64(x - Float64(Float64(y + 0.5) * log(y))) + y) - z)
end
function tmp = code(x, y, z)
	tmp = ((x - ((y + 0.5) * log(y))) + y) - z;
end
code[x_, y_, z_] := N[(N[(N[(x - N[(N[(y + 0.5), $MachinePrecision] * N[Log[y], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + y), $MachinePrecision] - z), $MachinePrecision]
\begin{array}{l}

\\
\left(\left(x - \left(y + 0.5\right) \cdot \log y\right) + y\right) - z
\end{array}

Alternative 1: 99.9% accurate, 0.5× speedup?

\[\begin{array}{l} \\ x + \mathsf{fma}\left(\log y, -0.5 - y, y - z\right) \end{array} \]
(FPCore (x y z) :precision binary64 (+ x (fma (log y) (- -0.5 y) (- y z))))
double code(double x, double y, double z) {
	return x + fma(log(y), (-0.5 - y), (y - z));
}
function code(x, y, z)
	return Float64(x + fma(log(y), Float64(-0.5 - y), Float64(y - z)))
end
code[x_, y_, z_] := N[(x + N[(N[Log[y], $MachinePrecision] * N[(-0.5 - y), $MachinePrecision] + N[(y - z), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
x + \mathsf{fma}\left(\log y, -0.5 - y, y - z\right)
\end{array}
Derivation
  1. Initial program 99.8%

    \[\left(\left(x - \left(y + 0.5\right) \cdot \log y\right) + y\right) - z \]
  2. Step-by-step derivation
    1. associate--l+99.8%

      \[\leadsto \color{blue}{\left(x - \left(y + 0.5\right) \cdot \log y\right) + \left(y - z\right)} \]
    2. sub-neg99.8%

      \[\leadsto \color{blue}{\left(x + \left(-\left(y + 0.5\right) \cdot \log y\right)\right)} + \left(y - z\right) \]
    3. associate-+l+99.8%

      \[\leadsto \color{blue}{x + \left(\left(-\left(y + 0.5\right) \cdot \log y\right) + \left(y - z\right)\right)} \]
    4. *-commutative99.8%

      \[\leadsto x + \left(\left(-\color{blue}{\log y \cdot \left(y + 0.5\right)}\right) + \left(y - z\right)\right) \]
    5. distribute-rgt-neg-in99.8%

      \[\leadsto x + \left(\color{blue}{\log y \cdot \left(-\left(y + 0.5\right)\right)} + \left(y - z\right)\right) \]
    6. fma-def99.8%

      \[\leadsto x + \color{blue}{\mathsf{fma}\left(\log y, -\left(y + 0.5\right), y - z\right)} \]
    7. +-commutative99.8%

      \[\leadsto x + \mathsf{fma}\left(\log y, -\color{blue}{\left(0.5 + y\right)}, y - z\right) \]
    8. distribute-neg-in99.8%

      \[\leadsto x + \mathsf{fma}\left(\log y, \color{blue}{\left(-0.5\right) + \left(-y\right)}, y - z\right) \]
    9. unsub-neg99.8%

      \[\leadsto x + \mathsf{fma}\left(\log y, \color{blue}{\left(-0.5\right) - y}, y - z\right) \]
    10. metadata-eval99.8%

      \[\leadsto x + \mathsf{fma}\left(\log y, \color{blue}{-0.5} - y, y - z\right) \]
  3. Simplified99.8%

    \[\leadsto \color{blue}{x + \mathsf{fma}\left(\log y, -0.5 - y, y - z\right)} \]
  4. Final simplification99.8%

    \[\leadsto x + \mathsf{fma}\left(\log y, -0.5 - y, y - z\right) \]

Alternative 2: 68.4% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;y \leq 3.3 \cdot 10^{-35}:\\ \;\;\;\;x - z\\ \mathbf{elif}\;y \leq 107000000:\\ \;\;\;\;\log y \cdot -0.5 - z\\ \mathbf{elif}\;y \leq 9.8 \cdot 10^{+86} \lor \neg \left(y \leq 5.2 \cdot 10^{+186}\right) \land y \leq 6.2 \cdot 10^{+208}:\\ \;\;\;\;x - z\\ \mathbf{else}:\\ \;\;\;\;y - y \cdot \log y\\ \end{array} \end{array} \]
(FPCore (x y z)
 :precision binary64
 (if (<= y 3.3e-35)
   (- x z)
   (if (<= y 107000000.0)
     (- (* (log y) -0.5) z)
     (if (or (<= y 9.8e+86) (and (not (<= y 5.2e+186)) (<= y 6.2e+208)))
       (- x z)
       (- y (* y (log y)))))))
double code(double x, double y, double z) {
	double tmp;
	if (y <= 3.3e-35) {
		tmp = x - z;
	} else if (y <= 107000000.0) {
		tmp = (log(y) * -0.5) - z;
	} else if ((y <= 9.8e+86) || (!(y <= 5.2e+186) && (y <= 6.2e+208))) {
		tmp = x - z;
	} else {
		tmp = y - (y * log(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 (y <= 3.3d-35) then
        tmp = x - z
    else if (y <= 107000000.0d0) then
        tmp = (log(y) * (-0.5d0)) - z
    else if ((y <= 9.8d+86) .or. (.not. (y <= 5.2d+186)) .and. (y <= 6.2d+208)) then
        tmp = x - z
    else
        tmp = y - (y * log(y))
    end if
    code = tmp
end function
public static double code(double x, double y, double z) {
	double tmp;
	if (y <= 3.3e-35) {
		tmp = x - z;
	} else if (y <= 107000000.0) {
		tmp = (Math.log(y) * -0.5) - z;
	} else if ((y <= 9.8e+86) || (!(y <= 5.2e+186) && (y <= 6.2e+208))) {
		tmp = x - z;
	} else {
		tmp = y - (y * Math.log(y));
	}
	return tmp;
}
def code(x, y, z):
	tmp = 0
	if y <= 3.3e-35:
		tmp = x - z
	elif y <= 107000000.0:
		tmp = (math.log(y) * -0.5) - z
	elif (y <= 9.8e+86) or (not (y <= 5.2e+186) and (y <= 6.2e+208)):
		tmp = x - z
	else:
		tmp = y - (y * math.log(y))
	return tmp
function code(x, y, z)
	tmp = 0.0
	if (y <= 3.3e-35)
		tmp = Float64(x - z);
	elseif (y <= 107000000.0)
		tmp = Float64(Float64(log(y) * -0.5) - z);
	elseif ((y <= 9.8e+86) || (!(y <= 5.2e+186) && (y <= 6.2e+208)))
		tmp = Float64(x - z);
	else
		tmp = Float64(y - Float64(y * log(y)));
	end
	return tmp
end
function tmp_2 = code(x, y, z)
	tmp = 0.0;
	if (y <= 3.3e-35)
		tmp = x - z;
	elseif (y <= 107000000.0)
		tmp = (log(y) * -0.5) - z;
	elseif ((y <= 9.8e+86) || (~((y <= 5.2e+186)) && (y <= 6.2e+208)))
		tmp = x - z;
	else
		tmp = y - (y * log(y));
	end
	tmp_2 = tmp;
end
code[x_, y_, z_] := If[LessEqual[y, 3.3e-35], N[(x - z), $MachinePrecision], If[LessEqual[y, 107000000.0], N[(N[(N[Log[y], $MachinePrecision] * -0.5), $MachinePrecision] - z), $MachinePrecision], If[Or[LessEqual[y, 9.8e+86], And[N[Not[LessEqual[y, 5.2e+186]], $MachinePrecision], LessEqual[y, 6.2e+208]]], N[(x - z), $MachinePrecision], N[(y - N[(y * N[Log[y], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;y \leq 3.3 \cdot 10^{-35}:\\
\;\;\;\;x - z\\

\mathbf{elif}\;y \leq 107000000:\\
\;\;\;\;\log y \cdot -0.5 - z\\

\mathbf{elif}\;y \leq 9.8 \cdot 10^{+86} \lor \neg \left(y \leq 5.2 \cdot 10^{+186}\right) \land y \leq 6.2 \cdot 10^{+208}:\\
\;\;\;\;x - z\\

\mathbf{else}:\\
\;\;\;\;y - y \cdot \log y\\


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if y < 3.3e-35 or 1.07e8 < y < 9.7999999999999999e86 or 5.2000000000000001e186 < y < 6.19999999999999961e208

    1. Initial program 100.0%

      \[\left(\left(x - \left(y + 0.5\right) \cdot \log y\right) + y\right) - z \]
    2. Taylor expanded in y around 0 100.0%

      \[\leadsto \color{blue}{\left(\left(x + y \cdot \left(1 - \log y\right)\right) - 0.5 \cdot \log y\right)} - z \]
    3. Taylor expanded in x around inf 79.7%

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

    if 3.3e-35 < y < 1.07e8

    1. Initial program 99.5%

      \[\left(\left(x - \left(y + 0.5\right) \cdot \log y\right) + y\right) - z \]
    2. Taylor expanded in y around 0 99.7%

      \[\leadsto \color{blue}{\left(\left(x + y \cdot \left(1 - \log y\right)\right) - 0.5 \cdot \log y\right)} - z \]
    3. Taylor expanded in x around 0 94.9%

      \[\leadsto \color{blue}{\left(y \cdot \left(1 - \log y\right) - 0.5 \cdot \log y\right)} - z \]
    4. Taylor expanded in y around 0 80.9%

      \[\leadsto \color{blue}{-0.5 \cdot \log y} - z \]

    if 9.7999999999999999e86 < y < 5.2000000000000001e186 or 6.19999999999999961e208 < y

    1. Initial program 99.5%

      \[\left(\left(x - \left(y + 0.5\right) \cdot \log y\right) + y\right) - z \]
    2. Taylor expanded in y around inf 86.5%

      \[\leadsto \left(\color{blue}{y \cdot \log \left(\frac{1}{y}\right)} + y\right) - z \]
    3. Step-by-step derivation
      1. log-rec86.5%

        \[\leadsto \left(y \cdot \color{blue}{\left(-\log y\right)} + y\right) - z \]
    4. Simplified86.5%

      \[\leadsto \left(\color{blue}{y \cdot \left(-\log y\right)} + y\right) - z \]
    5. Taylor expanded in z around 0 86.5%

      \[\leadsto \color{blue}{y + \left(-1 \cdot z + -1 \cdot \left(y \cdot \log y\right)\right)} \]
    6. Step-by-step derivation
      1. neg-mul-186.5%

        \[\leadsto y + \left(\color{blue}{\left(-z\right)} + -1 \cdot \left(y \cdot \log y\right)\right) \]
      2. associate-+r+86.5%

        \[\leadsto \color{blue}{\left(y + \left(-z\right)\right) + -1 \cdot \left(y \cdot \log y\right)} \]
      3. sub-neg86.5%

        \[\leadsto \color{blue}{\left(y - z\right)} + -1 \cdot \left(y \cdot \log y\right) \]
      4. neg-mul-186.5%

        \[\leadsto \left(y - z\right) + \color{blue}{\left(-y \cdot \log y\right)} \]
      5. sub-neg86.5%

        \[\leadsto \color{blue}{\left(y - z\right) - y \cdot \log y} \]
    7. Simplified86.5%

      \[\leadsto \color{blue}{\left(y - z\right) - y \cdot \log y} \]
    8. Taylor expanded in z around 0 79.0%

      \[\leadsto \color{blue}{y - y \cdot \log y} \]
  3. Recombined 3 regimes into one program.
  4. Final simplification79.5%

    \[\leadsto \begin{array}{l} \mathbf{if}\;y \leq 3.3 \cdot 10^{-35}:\\ \;\;\;\;x - z\\ \mathbf{elif}\;y \leq 107000000:\\ \;\;\;\;\log y \cdot -0.5 - z\\ \mathbf{elif}\;y \leq 9.8 \cdot 10^{+86} \lor \neg \left(y \leq 5.2 \cdot 10^{+186}\right) \land y \leq 6.2 \cdot 10^{+208}:\\ \;\;\;\;x - z\\ \mathbf{else}:\\ \;\;\;\;y - y \cdot \log y\\ \end{array} \]

Alternative 3: 88.5% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;y \leq 5 \cdot 10^{+87}:\\ \;\;\;\;\left(x - \log y \cdot 0.5\right) - z\\ \mathbf{elif}\;y \leq 3.5 \cdot 10^{+187} \lor \neg \left(y \leq 1.36 \cdot 10^{+208}\right):\\ \;\;\;\;x + y \cdot \left(1 - \log y\right)\\ \mathbf{else}:\\ \;\;\;\;x - z\\ \end{array} \end{array} \]
(FPCore (x y z)
 :precision binary64
 (if (<= y 5e+87)
   (- (- x (* (log y) 0.5)) z)
   (if (or (<= y 3.5e+187) (not (<= y 1.36e+208)))
     (+ x (* y (- 1.0 (log y))))
     (- x z))))
double code(double x, double y, double z) {
	double tmp;
	if (y <= 5e+87) {
		tmp = (x - (log(y) * 0.5)) - z;
	} else if ((y <= 3.5e+187) || !(y <= 1.36e+208)) {
		tmp = x + (y * (1.0 - log(y)));
	} else {
		tmp = x - 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+87) then
        tmp = (x - (log(y) * 0.5d0)) - z
    else if ((y <= 3.5d+187) .or. (.not. (y <= 1.36d+208))) then
        tmp = x + (y * (1.0d0 - log(y)))
    else
        tmp = x - z
    end if
    code = tmp
end function
public static double code(double x, double y, double z) {
	double tmp;
	if (y <= 5e+87) {
		tmp = (x - (Math.log(y) * 0.5)) - z;
	} else if ((y <= 3.5e+187) || !(y <= 1.36e+208)) {
		tmp = x + (y * (1.0 - Math.log(y)));
	} else {
		tmp = x - z;
	}
	return tmp;
}
def code(x, y, z):
	tmp = 0
	if y <= 5e+87:
		tmp = (x - (math.log(y) * 0.5)) - z
	elif (y <= 3.5e+187) or not (y <= 1.36e+208):
		tmp = x + (y * (1.0 - math.log(y)))
	else:
		tmp = x - z
	return tmp
function code(x, y, z)
	tmp = 0.0
	if (y <= 5e+87)
		tmp = Float64(Float64(x - Float64(log(y) * 0.5)) - z);
	elseif ((y <= 3.5e+187) || !(y <= 1.36e+208))
		tmp = Float64(x + Float64(y * Float64(1.0 - log(y))));
	else
		tmp = Float64(x - z);
	end
	return tmp
end
function tmp_2 = code(x, y, z)
	tmp = 0.0;
	if (y <= 5e+87)
		tmp = (x - (log(y) * 0.5)) - z;
	elseif ((y <= 3.5e+187) || ~((y <= 1.36e+208)))
		tmp = x + (y * (1.0 - log(y)));
	else
		tmp = x - z;
	end
	tmp_2 = tmp;
end
code[x_, y_, z_] := If[LessEqual[y, 5e+87], N[(N[(x - N[(N[Log[y], $MachinePrecision] * 0.5), $MachinePrecision]), $MachinePrecision] - z), $MachinePrecision], If[Or[LessEqual[y, 3.5e+187], N[Not[LessEqual[y, 1.36e+208]], $MachinePrecision]], N[(x + N[(y * N[(1.0 - N[Log[y], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(x - z), $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;y \leq 5 \cdot 10^{+87}:\\
\;\;\;\;\left(x - \log y \cdot 0.5\right) - z\\

\mathbf{elif}\;y \leq 3.5 \cdot 10^{+187} \lor \neg \left(y \leq 1.36 \cdot 10^{+208}\right):\\
\;\;\;\;x + y \cdot \left(1 - \log y\right)\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if y < 4.9999999999999998e87

    1. Initial program 99.9%

      \[\left(\left(x - \left(y + 0.5\right) \cdot \log y\right) + y\right) - z \]
    2. Taylor expanded in y around 0 93.3%

      \[\leadsto \color{blue}{\left(x - 0.5 \cdot \log y\right)} - z \]

    if 4.9999999999999998e87 < y < 3.4999999999999998e187 or 1.3599999999999999e208 < y

    1. Initial program 99.5%

      \[\left(\left(x - \left(y + 0.5\right) \cdot \log y\right) + y\right) - z \]
    2. Step-by-step derivation
      1. associate--l+99.5%

        \[\leadsto \color{blue}{\left(x - \left(y + 0.5\right) \cdot \log y\right) + \left(y - z\right)} \]
      2. sub-neg99.5%

        \[\leadsto \color{blue}{\left(x + \left(-\left(y + 0.5\right) \cdot \log y\right)\right)} + \left(y - z\right) \]
      3. associate-+l+99.5%

        \[\leadsto \color{blue}{x + \left(\left(-\left(y + 0.5\right) \cdot \log y\right) + \left(y - z\right)\right)} \]
      4. *-commutative99.5%

        \[\leadsto x + \left(\left(-\color{blue}{\log y \cdot \left(y + 0.5\right)}\right) + \left(y - z\right)\right) \]
      5. distribute-rgt-neg-in99.5%

        \[\leadsto x + \left(\color{blue}{\log y \cdot \left(-\left(y + 0.5\right)\right)} + \left(y - z\right)\right) \]
      6. fma-def99.7%

        \[\leadsto x + \color{blue}{\mathsf{fma}\left(\log y, -\left(y + 0.5\right), y - z\right)} \]
      7. +-commutative99.7%

        \[\leadsto x + \mathsf{fma}\left(\log y, -\color{blue}{\left(0.5 + y\right)}, y - z\right) \]
      8. distribute-neg-in99.7%

        \[\leadsto x + \mathsf{fma}\left(\log y, \color{blue}{\left(-0.5\right) + \left(-y\right)}, y - z\right) \]
      9. unsub-neg99.7%

        \[\leadsto x + \mathsf{fma}\left(\log y, \color{blue}{\left(-0.5\right) - y}, y - z\right) \]
      10. metadata-eval99.7%

        \[\leadsto x + \mathsf{fma}\left(\log y, \color{blue}{-0.5} - y, y - z\right) \]
    3. Simplified99.7%

      \[\leadsto \color{blue}{x + \mathsf{fma}\left(\log y, -0.5 - y, y - z\right)} \]
    4. Taylor expanded in y around inf 93.2%

      \[\leadsto x + \color{blue}{y \cdot \left(1 + \log \left(\frac{1}{y}\right)\right)} \]
    5. Step-by-step derivation
      1. log-rec93.2%

        \[\leadsto x + y \cdot \left(1 + \color{blue}{\left(-\log y\right)}\right) \]
      2. sub-neg93.2%

        \[\leadsto x + y \cdot \color{blue}{\left(1 - \log y\right)} \]
    6. Simplified93.2%

      \[\leadsto x + \color{blue}{y \cdot \left(1 - \log y\right)} \]

    if 3.4999999999999998e187 < y < 1.3599999999999999e208

    1. Initial program 100.0%

      \[\left(\left(x - \left(y + 0.5\right) \cdot \log y\right) + y\right) - z \]
    2. Taylor expanded in y around 0 100.0%

      \[\leadsto \color{blue}{\left(\left(x + y \cdot \left(1 - \log y\right)\right) - 0.5 \cdot \log y\right)} - z \]
    3. Taylor expanded in x around inf 100.0%

      \[\leadsto \color{blue}{x} - z \]
  3. Recombined 3 regimes into one program.
  4. Final simplification93.5%

    \[\leadsto \begin{array}{l} \mathbf{if}\;y \leq 5 \cdot 10^{+87}:\\ \;\;\;\;\left(x - \log y \cdot 0.5\right) - z\\ \mathbf{elif}\;y \leq 3.5 \cdot 10^{+187} \lor \neg \left(y \leq 1.36 \cdot 10^{+208}\right):\\ \;\;\;\;x + y \cdot \left(1 - \log y\right)\\ \mathbf{else}:\\ \;\;\;\;x - z\\ \end{array} \]

Alternative 4: 69.9% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;y \leq 1.76 \cdot 10^{+87} \lor \neg \left(y \leq 3.5 \cdot 10^{+187}\right) \land y \leq 6.2 \cdot 10^{+208}:\\ \;\;\;\;x - z\\ \mathbf{else}:\\ \;\;\;\;y - y \cdot \log y\\ \end{array} \end{array} \]
(FPCore (x y z)
 :precision binary64
 (if (or (<= y 1.76e+87) (and (not (<= y 3.5e+187)) (<= y 6.2e+208)))
   (- x z)
   (- y (* y (log y)))))
double code(double x, double y, double z) {
	double tmp;
	if ((y <= 1.76e+87) || (!(y <= 3.5e+187) && (y <= 6.2e+208))) {
		tmp = x - z;
	} else {
		tmp = y - (y * log(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 ((y <= 1.76d+87) .or. (.not. (y <= 3.5d+187)) .and. (y <= 6.2d+208)) then
        tmp = x - z
    else
        tmp = y - (y * log(y))
    end if
    code = tmp
end function
public static double code(double x, double y, double z) {
	double tmp;
	if ((y <= 1.76e+87) || (!(y <= 3.5e+187) && (y <= 6.2e+208))) {
		tmp = x - z;
	} else {
		tmp = y - (y * Math.log(y));
	}
	return tmp;
}
def code(x, y, z):
	tmp = 0
	if (y <= 1.76e+87) or (not (y <= 3.5e+187) and (y <= 6.2e+208)):
		tmp = x - z
	else:
		tmp = y - (y * math.log(y))
	return tmp
function code(x, y, z)
	tmp = 0.0
	if ((y <= 1.76e+87) || (!(y <= 3.5e+187) && (y <= 6.2e+208)))
		tmp = Float64(x - z);
	else
		tmp = Float64(y - Float64(y * log(y)));
	end
	return tmp
end
function tmp_2 = code(x, y, z)
	tmp = 0.0;
	if ((y <= 1.76e+87) || (~((y <= 3.5e+187)) && (y <= 6.2e+208)))
		tmp = x - z;
	else
		tmp = y - (y * log(y));
	end
	tmp_2 = tmp;
end
code[x_, y_, z_] := If[Or[LessEqual[y, 1.76e+87], And[N[Not[LessEqual[y, 3.5e+187]], $MachinePrecision], LessEqual[y, 6.2e+208]]], N[(x - z), $MachinePrecision], N[(y - N[(y * N[Log[y], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;y \leq 1.76 \cdot 10^{+87} \lor \neg \left(y \leq 3.5 \cdot 10^{+187}\right) \land y \leq 6.2 \cdot 10^{+208}:\\
\;\;\;\;x - z\\

\mathbf{else}:\\
\;\;\;\;y - y \cdot \log y\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if y < 1.76000000000000003e87 or 3.4999999999999998e187 < y < 6.19999999999999961e208

    1. Initial program 99.9%

      \[\left(\left(x - \left(y + 0.5\right) \cdot \log y\right) + y\right) - z \]
    2. Taylor expanded in y around 0 99.9%

      \[\leadsto \color{blue}{\left(\left(x + y \cdot \left(1 - \log y\right)\right) - 0.5 \cdot \log y\right)} - z \]
    3. Taylor expanded in x around inf 76.8%

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

    if 1.76000000000000003e87 < y < 3.4999999999999998e187 or 6.19999999999999961e208 < y

    1. Initial program 99.5%

      \[\left(\left(x - \left(y + 0.5\right) \cdot \log y\right) + y\right) - z \]
    2. Taylor expanded in y around inf 86.5%

      \[\leadsto \left(\color{blue}{y \cdot \log \left(\frac{1}{y}\right)} + y\right) - z \]
    3. Step-by-step derivation
      1. log-rec86.5%

        \[\leadsto \left(y \cdot \color{blue}{\left(-\log y\right)} + y\right) - z \]
    4. Simplified86.5%

      \[\leadsto \left(\color{blue}{y \cdot \left(-\log y\right)} + y\right) - z \]
    5. Taylor expanded in z around 0 86.5%

      \[\leadsto \color{blue}{y + \left(-1 \cdot z + -1 \cdot \left(y \cdot \log y\right)\right)} \]
    6. Step-by-step derivation
      1. neg-mul-186.5%

        \[\leadsto y + \left(\color{blue}{\left(-z\right)} + -1 \cdot \left(y \cdot \log y\right)\right) \]
      2. associate-+r+86.5%

        \[\leadsto \color{blue}{\left(y + \left(-z\right)\right) + -1 \cdot \left(y \cdot \log y\right)} \]
      3. sub-neg86.5%

        \[\leadsto \color{blue}{\left(y - z\right)} + -1 \cdot \left(y \cdot \log y\right) \]
      4. neg-mul-186.5%

        \[\leadsto \left(y - z\right) + \color{blue}{\left(-y \cdot \log y\right)} \]
      5. sub-neg86.5%

        \[\leadsto \color{blue}{\left(y - z\right) - y \cdot \log y} \]
    7. Simplified86.5%

      \[\leadsto \color{blue}{\left(y - z\right) - y \cdot \log y} \]
    8. Taylor expanded in z around 0 79.0%

      \[\leadsto \color{blue}{y - y \cdot \log y} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification77.6%

    \[\leadsto \begin{array}{l} \mathbf{if}\;y \leq 1.76 \cdot 10^{+87} \lor \neg \left(y \leq 3.5 \cdot 10^{+187}\right) \land y \leq 6.2 \cdot 10^{+208}:\\ \;\;\;\;x - z\\ \mathbf{else}:\\ \;\;\;\;y - y \cdot \log y\\ \end{array} \]

Alternative 5: 76.4% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;z \leq -3.2 \cdot 10^{+42} \lor \neg \left(z \leq 3.8 \cdot 10^{+107}\right):\\ \;\;\;\;x - z\\ \mathbf{else}:\\ \;\;\;\;x + y \cdot \left(1 - \log y\right)\\ \end{array} \end{array} \]
(FPCore (x y z)
 :precision binary64
 (if (or (<= z -3.2e+42) (not (<= z 3.8e+107)))
   (- x z)
   (+ x (* y (- 1.0 (log y))))))
double code(double x, double y, double z) {
	double tmp;
	if ((z <= -3.2e+42) || !(z <= 3.8e+107)) {
		tmp = x - z;
	} else {
		tmp = x + (y * (1.0 - log(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 <= (-3.2d+42)) .or. (.not. (z <= 3.8d+107))) then
        tmp = x - z
    else
        tmp = x + (y * (1.0d0 - log(y)))
    end if
    code = tmp
end function
public static double code(double x, double y, double z) {
	double tmp;
	if ((z <= -3.2e+42) || !(z <= 3.8e+107)) {
		tmp = x - z;
	} else {
		tmp = x + (y * (1.0 - Math.log(y)));
	}
	return tmp;
}
def code(x, y, z):
	tmp = 0
	if (z <= -3.2e+42) or not (z <= 3.8e+107):
		tmp = x - z
	else:
		tmp = x + (y * (1.0 - math.log(y)))
	return tmp
function code(x, y, z)
	tmp = 0.0
	if ((z <= -3.2e+42) || !(z <= 3.8e+107))
		tmp = Float64(x - z);
	else
		tmp = Float64(x + Float64(y * Float64(1.0 - log(y))));
	end
	return tmp
end
function tmp_2 = code(x, y, z)
	tmp = 0.0;
	if ((z <= -3.2e+42) || ~((z <= 3.8e+107)))
		tmp = x - z;
	else
		tmp = x + (y * (1.0 - log(y)));
	end
	tmp_2 = tmp;
end
code[x_, y_, z_] := If[Or[LessEqual[z, -3.2e+42], N[Not[LessEqual[z, 3.8e+107]], $MachinePrecision]], N[(x - z), $MachinePrecision], N[(x + N[(y * N[(1.0 - N[Log[y], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;z \leq -3.2 \cdot 10^{+42} \lor \neg \left(z \leq 3.8 \cdot 10^{+107}\right):\\
\;\;\;\;x - z\\

\mathbf{else}:\\
\;\;\;\;x + y \cdot \left(1 - \log y\right)\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if z < -3.20000000000000002e42 or 3.7999999999999998e107 < z

    1. Initial program 99.9%

      \[\left(\left(x - \left(y + 0.5\right) \cdot \log y\right) + y\right) - z \]
    2. Taylor expanded in y around 0 99.9%

      \[\leadsto \color{blue}{\left(\left(x + y \cdot \left(1 - \log y\right)\right) - 0.5 \cdot \log y\right)} - z \]
    3. Taylor expanded in x around inf 84.2%

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

    if -3.20000000000000002e42 < z < 3.7999999999999998e107

    1. Initial program 99.7%

      \[\left(\left(x - \left(y + 0.5\right) \cdot \log y\right) + y\right) - z \]
    2. Step-by-step derivation
      1. associate--l+99.7%

        \[\leadsto \color{blue}{\left(x - \left(y + 0.5\right) \cdot \log y\right) + \left(y - z\right)} \]
      2. sub-neg99.7%

        \[\leadsto \color{blue}{\left(x + \left(-\left(y + 0.5\right) \cdot \log y\right)\right)} + \left(y - z\right) \]
      3. associate-+l+99.7%

        \[\leadsto \color{blue}{x + \left(\left(-\left(y + 0.5\right) \cdot \log y\right) + \left(y - z\right)\right)} \]
      4. *-commutative99.7%

        \[\leadsto x + \left(\left(-\color{blue}{\log y \cdot \left(y + 0.5\right)}\right) + \left(y - z\right)\right) \]
      5. distribute-rgt-neg-in99.7%

        \[\leadsto x + \left(\color{blue}{\log y \cdot \left(-\left(y + 0.5\right)\right)} + \left(y - z\right)\right) \]
      6. fma-def99.8%

        \[\leadsto x + \color{blue}{\mathsf{fma}\left(\log y, -\left(y + 0.5\right), y - z\right)} \]
      7. +-commutative99.8%

        \[\leadsto x + \mathsf{fma}\left(\log y, -\color{blue}{\left(0.5 + y\right)}, y - z\right) \]
      8. distribute-neg-in99.8%

        \[\leadsto x + \mathsf{fma}\left(\log y, \color{blue}{\left(-0.5\right) + \left(-y\right)}, y - z\right) \]
      9. unsub-neg99.8%

        \[\leadsto x + \mathsf{fma}\left(\log y, \color{blue}{\left(-0.5\right) - y}, y - z\right) \]
      10. metadata-eval99.8%

        \[\leadsto x + \mathsf{fma}\left(\log y, \color{blue}{-0.5} - y, y - z\right) \]
    3. Simplified99.8%

      \[\leadsto \color{blue}{x + \mathsf{fma}\left(\log y, -0.5 - y, y - z\right)} \]
    4. Taylor expanded in y around inf 77.9%

      \[\leadsto x + \color{blue}{y \cdot \left(1 + \log \left(\frac{1}{y}\right)\right)} \]
    5. Step-by-step derivation
      1. log-rec77.9%

        \[\leadsto x + y \cdot \left(1 + \color{blue}{\left(-\log y\right)}\right) \]
      2. sub-neg77.9%

        \[\leadsto x + y \cdot \color{blue}{\left(1 - \log y\right)} \]
    6. Simplified77.9%

      \[\leadsto x + \color{blue}{y \cdot \left(1 - \log y\right)} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification80.4%

    \[\leadsto \begin{array}{l} \mathbf{if}\;z \leq -3.2 \cdot 10^{+42} \lor \neg \left(z \leq 3.8 \cdot 10^{+107}\right):\\ \;\;\;\;x - z\\ \mathbf{else}:\\ \;\;\;\;x + y \cdot \left(1 - \log y\right)\\ \end{array} \]

Alternative 6: 89.7% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;y \leq 2 \cdot 10^{+88}:\\ \;\;\;\;\left(x - \log y \cdot 0.5\right) - z\\ \mathbf{elif}\;y \leq 6.7 \cdot 10^{+187}:\\ \;\;\;\;x + y \cdot \left(1 - \log y\right)\\ \mathbf{else}:\\ \;\;\;\;\left(y - z\right) - y \cdot \log y\\ \end{array} \end{array} \]
(FPCore (x y z)
 :precision binary64
 (if (<= y 2e+88)
   (- (- x (* (log y) 0.5)) z)
   (if (<= y 6.7e+187) (+ x (* y (- 1.0 (log y)))) (- (- y z) (* y (log y))))))
double code(double x, double y, double z) {
	double tmp;
	if (y <= 2e+88) {
		tmp = (x - (log(y) * 0.5)) - z;
	} else if (y <= 6.7e+187) {
		tmp = x + (y * (1.0 - log(y)));
	} else {
		tmp = (y - z) - (y * log(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 (y <= 2d+88) then
        tmp = (x - (log(y) * 0.5d0)) - z
    else if (y <= 6.7d+187) then
        tmp = x + (y * (1.0d0 - log(y)))
    else
        tmp = (y - z) - (y * log(y))
    end if
    code = tmp
end function
public static double code(double x, double y, double z) {
	double tmp;
	if (y <= 2e+88) {
		tmp = (x - (Math.log(y) * 0.5)) - z;
	} else if (y <= 6.7e+187) {
		tmp = x + (y * (1.0 - Math.log(y)));
	} else {
		tmp = (y - z) - (y * Math.log(y));
	}
	return tmp;
}
def code(x, y, z):
	tmp = 0
	if y <= 2e+88:
		tmp = (x - (math.log(y) * 0.5)) - z
	elif y <= 6.7e+187:
		tmp = x + (y * (1.0 - math.log(y)))
	else:
		tmp = (y - z) - (y * math.log(y))
	return tmp
function code(x, y, z)
	tmp = 0.0
	if (y <= 2e+88)
		tmp = Float64(Float64(x - Float64(log(y) * 0.5)) - z);
	elseif (y <= 6.7e+187)
		tmp = Float64(x + Float64(y * Float64(1.0 - log(y))));
	else
		tmp = Float64(Float64(y - z) - Float64(y * log(y)));
	end
	return tmp
end
function tmp_2 = code(x, y, z)
	tmp = 0.0;
	if (y <= 2e+88)
		tmp = (x - (log(y) * 0.5)) - z;
	elseif (y <= 6.7e+187)
		tmp = x + (y * (1.0 - log(y)));
	else
		tmp = (y - z) - (y * log(y));
	end
	tmp_2 = tmp;
end
code[x_, y_, z_] := If[LessEqual[y, 2e+88], N[(N[(x - N[(N[Log[y], $MachinePrecision] * 0.5), $MachinePrecision]), $MachinePrecision] - z), $MachinePrecision], If[LessEqual[y, 6.7e+187], N[(x + N[(y * N[(1.0 - N[Log[y], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(N[(y - z), $MachinePrecision] - N[(y * N[Log[y], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;y \leq 2 \cdot 10^{+88}:\\
\;\;\;\;\left(x - \log y \cdot 0.5\right) - z\\

\mathbf{elif}\;y \leq 6.7 \cdot 10^{+187}:\\
\;\;\;\;x + y \cdot \left(1 - \log y\right)\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if y < 1.99999999999999992e88

    1. Initial program 99.9%

      \[\left(\left(x - \left(y + 0.5\right) \cdot \log y\right) + y\right) - z \]
    2. Taylor expanded in y around 0 93.3%

      \[\leadsto \color{blue}{\left(x - 0.5 \cdot \log y\right)} - z \]

    if 1.99999999999999992e88 < y < 6.7000000000000001e187

    1. Initial program 99.6%

      \[\left(\left(x - \left(y + 0.5\right) \cdot \log y\right) + y\right) - z \]
    2. Step-by-step derivation
      1. associate--l+99.6%

        \[\leadsto \color{blue}{\left(x - \left(y + 0.5\right) \cdot \log y\right) + \left(y - z\right)} \]
      2. sub-neg99.6%

        \[\leadsto \color{blue}{\left(x + \left(-\left(y + 0.5\right) \cdot \log y\right)\right)} + \left(y - z\right) \]
      3. associate-+l+99.7%

        \[\leadsto \color{blue}{x + \left(\left(-\left(y + 0.5\right) \cdot \log y\right) + \left(y - z\right)\right)} \]
      4. *-commutative99.7%

        \[\leadsto x + \left(\left(-\color{blue}{\log y \cdot \left(y + 0.5\right)}\right) + \left(y - z\right)\right) \]
      5. distribute-rgt-neg-in99.7%

        \[\leadsto x + \left(\color{blue}{\log y \cdot \left(-\left(y + 0.5\right)\right)} + \left(y - z\right)\right) \]
      6. fma-def99.8%

        \[\leadsto x + \color{blue}{\mathsf{fma}\left(\log y, -\left(y + 0.5\right), y - z\right)} \]
      7. +-commutative99.8%

        \[\leadsto x + \mathsf{fma}\left(\log y, -\color{blue}{\left(0.5 + y\right)}, y - z\right) \]
      8. distribute-neg-in99.8%

        \[\leadsto x + \mathsf{fma}\left(\log y, \color{blue}{\left(-0.5\right) + \left(-y\right)}, y - z\right) \]
      9. unsub-neg99.8%

        \[\leadsto x + \mathsf{fma}\left(\log y, \color{blue}{\left(-0.5\right) - y}, y - z\right) \]
      10. metadata-eval99.8%

        \[\leadsto x + \mathsf{fma}\left(\log y, \color{blue}{-0.5} - y, y - z\right) \]
    3. Simplified99.8%

      \[\leadsto \color{blue}{x + \mathsf{fma}\left(\log y, -0.5 - y, y - z\right)} \]
    4. Taylor expanded in y around inf 94.8%

      \[\leadsto x + \color{blue}{y \cdot \left(1 + \log \left(\frac{1}{y}\right)\right)} \]
    5. Step-by-step derivation
      1. log-rec94.8%

        \[\leadsto x + y \cdot \left(1 + \color{blue}{\left(-\log y\right)}\right) \]
      2. sub-neg94.8%

        \[\leadsto x + y \cdot \color{blue}{\left(1 - \log y\right)} \]
    6. Simplified94.8%

      \[\leadsto x + \color{blue}{y \cdot \left(1 - \log y\right)} \]

    if 6.7000000000000001e187 < y

    1. Initial program 99.5%

      \[\left(\left(x - \left(y + 0.5\right) \cdot \log y\right) + y\right) - z \]
    2. Taylor expanded in y around inf 91.3%

      \[\leadsto \left(\color{blue}{y \cdot \log \left(\frac{1}{y}\right)} + y\right) - z \]
    3. Step-by-step derivation
      1. log-rec91.3%

        \[\leadsto \left(y \cdot \color{blue}{\left(-\log y\right)} + y\right) - z \]
    4. Simplified91.3%

      \[\leadsto \left(\color{blue}{y \cdot \left(-\log y\right)} + y\right) - z \]
    5. Taylor expanded in z around 0 91.3%

      \[\leadsto \color{blue}{y + \left(-1 \cdot z + -1 \cdot \left(y \cdot \log y\right)\right)} \]
    6. Step-by-step derivation
      1. neg-mul-191.3%

        \[\leadsto y + \left(\color{blue}{\left(-z\right)} + -1 \cdot \left(y \cdot \log y\right)\right) \]
      2. associate-+r+91.3%

        \[\leadsto \color{blue}{\left(y + \left(-z\right)\right) + -1 \cdot \left(y \cdot \log y\right)} \]
      3. sub-neg91.3%

        \[\leadsto \color{blue}{\left(y - z\right)} + -1 \cdot \left(y \cdot \log y\right) \]
      4. neg-mul-191.3%

        \[\leadsto \left(y - z\right) + \color{blue}{\left(-y \cdot \log y\right)} \]
      5. sub-neg91.3%

        \[\leadsto \color{blue}{\left(y - z\right) - y \cdot \log y} \]
    7. Simplified91.3%

      \[\leadsto \color{blue}{\left(y - z\right) - y \cdot \log y} \]
  3. Recombined 3 regimes into one program.
  4. Final simplification93.1%

    \[\leadsto \begin{array}{l} \mathbf{if}\;y \leq 2 \cdot 10^{+88}:\\ \;\;\;\;\left(x - \log y \cdot 0.5\right) - z\\ \mathbf{elif}\;y \leq 6.7 \cdot 10^{+187}:\\ \;\;\;\;x + y \cdot \left(1 - \log y\right)\\ \mathbf{else}:\\ \;\;\;\;\left(y - z\right) - y \cdot \log y\\ \end{array} \]

Alternative 7: 99.8% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \left(y + \left(x - \log y \cdot \left(y + 0.5\right)\right)\right) - z \end{array} \]
(FPCore (x y z) :precision binary64 (- (+ y (- x (* (log y) (+ y 0.5)))) z))
double code(double x, double y, double z) {
	return (y + (x - (log(y) * (y + 0.5)))) - z;
}
real(8) function code(x, y, z)
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    real(8), intent (in) :: z
    code = (y + (x - (log(y) * (y + 0.5d0)))) - z
end function
public static double code(double x, double y, double z) {
	return (y + (x - (Math.log(y) * (y + 0.5)))) - z;
}
def code(x, y, z):
	return (y + (x - (math.log(y) * (y + 0.5)))) - z
function code(x, y, z)
	return Float64(Float64(y + Float64(x - Float64(log(y) * Float64(y + 0.5)))) - z)
end
function tmp = code(x, y, z)
	tmp = (y + (x - (log(y) * (y + 0.5)))) - z;
end
code[x_, y_, z_] := N[(N[(y + N[(x - N[(N[Log[y], $MachinePrecision] * N[(y + 0.5), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] - z), $MachinePrecision]
\begin{array}{l}

\\
\left(y + \left(x - \log y \cdot \left(y + 0.5\right)\right)\right) - z
\end{array}
Derivation
  1. Initial program 99.8%

    \[\left(\left(x - \left(y + 0.5\right) \cdot \log y\right) + y\right) - z \]
  2. Final simplification99.8%

    \[\leadsto \left(y + \left(x - \log y \cdot \left(y + 0.5\right)\right)\right) - z \]

Alternative 8: 70.3% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;z \leq -4100000000 \lor \neg \left(z \leq 8.6 \cdot 10^{-11}\right):\\ \;\;\;\;x - z\\ \mathbf{else}:\\ \;\;\;\;x - \log y \cdot 0.5\\ \end{array} \end{array} \]
(FPCore (x y z)
 :precision binary64
 (if (or (<= z -4100000000.0) (not (<= z 8.6e-11)))
   (- x z)
   (- x (* (log y) 0.5))))
double code(double x, double y, double z) {
	double tmp;
	if ((z <= -4100000000.0) || !(z <= 8.6e-11)) {
		tmp = x - z;
	} else {
		tmp = x - (log(y) * 0.5);
	}
	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 <= (-4100000000.0d0)) .or. (.not. (z <= 8.6d-11))) then
        tmp = x - z
    else
        tmp = x - (log(y) * 0.5d0)
    end if
    code = tmp
end function
public static double code(double x, double y, double z) {
	double tmp;
	if ((z <= -4100000000.0) || !(z <= 8.6e-11)) {
		tmp = x - z;
	} else {
		tmp = x - (Math.log(y) * 0.5);
	}
	return tmp;
}
def code(x, y, z):
	tmp = 0
	if (z <= -4100000000.0) or not (z <= 8.6e-11):
		tmp = x - z
	else:
		tmp = x - (math.log(y) * 0.5)
	return tmp
function code(x, y, z)
	tmp = 0.0
	if ((z <= -4100000000.0) || !(z <= 8.6e-11))
		tmp = Float64(x - z);
	else
		tmp = Float64(x - Float64(log(y) * 0.5));
	end
	return tmp
end
function tmp_2 = code(x, y, z)
	tmp = 0.0;
	if ((z <= -4100000000.0) || ~((z <= 8.6e-11)))
		tmp = x - z;
	else
		tmp = x - (log(y) * 0.5);
	end
	tmp_2 = tmp;
end
code[x_, y_, z_] := If[Or[LessEqual[z, -4100000000.0], N[Not[LessEqual[z, 8.6e-11]], $MachinePrecision]], N[(x - z), $MachinePrecision], N[(x - N[(N[Log[y], $MachinePrecision] * 0.5), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;z \leq -4100000000 \lor \neg \left(z \leq 8.6 \cdot 10^{-11}\right):\\
\;\;\;\;x - z\\

\mathbf{else}:\\
\;\;\;\;x - \log y \cdot 0.5\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if z < -4.1e9 or 8.60000000000000003e-11 < z

    1. Initial program 99.9%

      \[\left(\left(x - \left(y + 0.5\right) \cdot \log y\right) + y\right) - z \]
    2. Taylor expanded in y around 0 99.9%

      \[\leadsto \color{blue}{\left(\left(x + y \cdot \left(1 - \log y\right)\right) - 0.5 \cdot \log y\right)} - z \]
    3. Taylor expanded in x around inf 77.8%

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

    if -4.1e9 < z < 8.60000000000000003e-11

    1. Initial program 99.7%

      \[\left(\left(x - \left(y + 0.5\right) \cdot \log y\right) + y\right) - z \]
    2. Taylor expanded in y around 0 58.6%

      \[\leadsto \color{blue}{\left(x - 0.5 \cdot \log y\right)} - z \]
    3. Taylor expanded in z around 0 58.2%

      \[\leadsto \color{blue}{x - 0.5 \cdot \log y} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification68.1%

    \[\leadsto \begin{array}{l} \mathbf{if}\;z \leq -4100000000 \lor \neg \left(z \leq 8.6 \cdot 10^{-11}\right):\\ \;\;\;\;x - z\\ \mathbf{else}:\\ \;\;\;\;x - \log y \cdot 0.5\\ \end{array} \]

Alternative 9: 48.3% accurate, 18.1× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;z \leq -6.2 \cdot 10^{+44} \lor \neg \left(z \leq 1.2 \cdot 10^{+50}\right):\\ \;\;\;\;-z\\ \mathbf{else}:\\ \;\;\;\;x\\ \end{array} \end{array} \]
(FPCore (x y z)
 :precision binary64
 (if (or (<= z -6.2e+44) (not (<= z 1.2e+50))) (- z) x))
double code(double x, double y, double z) {
	double tmp;
	if ((z <= -6.2e+44) || !(z <= 1.2e+50)) {
		tmp = -z;
	} else {
		tmp = 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 <= (-6.2d+44)) .or. (.not. (z <= 1.2d+50))) then
        tmp = -z
    else
        tmp = x
    end if
    code = tmp
end function
public static double code(double x, double y, double z) {
	double tmp;
	if ((z <= -6.2e+44) || !(z <= 1.2e+50)) {
		tmp = -z;
	} else {
		tmp = x;
	}
	return tmp;
}
def code(x, y, z):
	tmp = 0
	if (z <= -6.2e+44) or not (z <= 1.2e+50):
		tmp = -z
	else:
		tmp = x
	return tmp
function code(x, y, z)
	tmp = 0.0
	if ((z <= -6.2e+44) || !(z <= 1.2e+50))
		tmp = Float64(-z);
	else
		tmp = x;
	end
	return tmp
end
function tmp_2 = code(x, y, z)
	tmp = 0.0;
	if ((z <= -6.2e+44) || ~((z <= 1.2e+50)))
		tmp = -z;
	else
		tmp = x;
	end
	tmp_2 = tmp;
end
code[x_, y_, z_] := If[Or[LessEqual[z, -6.2e+44], N[Not[LessEqual[z, 1.2e+50]], $MachinePrecision]], (-z), x]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;z \leq -6.2 \cdot 10^{+44} \lor \neg \left(z \leq 1.2 \cdot 10^{+50}\right):\\
\;\;\;\;-z\\

\mathbf{else}:\\
\;\;\;\;x\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if z < -6.19999999999999991e44 or 1.2000000000000001e50 < z

    1. Initial program 99.9%

      \[\left(\left(x - \left(y + 0.5\right) \cdot \log y\right) + y\right) - z \]
    2. Taylor expanded in y around 0 99.9%

      \[\leadsto \color{blue}{\left(\left(x + y \cdot \left(1 - \log y\right)\right) - 0.5 \cdot \log y\right)} - z \]
    3. Taylor expanded in z around inf 67.7%

      \[\leadsto \color{blue}{-1 \cdot z} \]
    4. Step-by-step derivation
      1. neg-mul-167.7%

        \[\leadsto \color{blue}{-z} \]
    5. Simplified67.7%

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

    if -6.19999999999999991e44 < z < 1.2000000000000001e50

    1. Initial program 99.7%

      \[\left(\left(x - \left(y + 0.5\right) \cdot \log y\right) + y\right) - z \]
    2. Step-by-step derivation
      1. associate--l+99.7%

        \[\leadsto \color{blue}{\left(x - \left(y + 0.5\right) \cdot \log y\right) + \left(y - z\right)} \]
      2. sub-neg99.7%

        \[\leadsto \color{blue}{\left(x + \left(-\left(y + 0.5\right) \cdot \log y\right)\right)} + \left(y - z\right) \]
      3. associate-+l+99.7%

        \[\leadsto \color{blue}{x + \left(\left(-\left(y + 0.5\right) \cdot \log y\right) + \left(y - z\right)\right)} \]
      4. *-commutative99.7%

        \[\leadsto x + \left(\left(-\color{blue}{\log y \cdot \left(y + 0.5\right)}\right) + \left(y - z\right)\right) \]
      5. distribute-rgt-neg-in99.7%

        \[\leadsto x + \left(\color{blue}{\log y \cdot \left(-\left(y + 0.5\right)\right)} + \left(y - z\right)\right) \]
      6. fma-def99.8%

        \[\leadsto x + \color{blue}{\mathsf{fma}\left(\log y, -\left(y + 0.5\right), y - z\right)} \]
      7. +-commutative99.8%

        \[\leadsto x + \mathsf{fma}\left(\log y, -\color{blue}{\left(0.5 + y\right)}, y - z\right) \]
      8. distribute-neg-in99.8%

        \[\leadsto x + \mathsf{fma}\left(\log y, \color{blue}{\left(-0.5\right) + \left(-y\right)}, y - z\right) \]
      9. unsub-neg99.8%

        \[\leadsto x + \mathsf{fma}\left(\log y, \color{blue}{\left(-0.5\right) - y}, y - z\right) \]
      10. metadata-eval99.8%

        \[\leadsto x + \mathsf{fma}\left(\log y, \color{blue}{-0.5} - y, y - z\right) \]
    3. Simplified99.8%

      \[\leadsto \color{blue}{x + \mathsf{fma}\left(\log y, -0.5 - y, y - z\right)} \]
    4. Taylor expanded in x around inf 37.7%

      \[\leadsto \color{blue}{x} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification50.1%

    \[\leadsto \begin{array}{l} \mathbf{if}\;z \leq -6.2 \cdot 10^{+44} \lor \neg \left(z \leq 1.2 \cdot 10^{+50}\right):\\ \;\;\;\;-z\\ \mathbf{else}:\\ \;\;\;\;x\\ \end{array} \]

Alternative 10: 58.0% accurate, 37.0× speedup?

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

\\
x - z
\end{array}
Derivation
  1. Initial program 99.8%

    \[\left(\left(x - \left(y + 0.5\right) \cdot \log y\right) + y\right) - z \]
  2. Taylor expanded in y around 0 99.8%

    \[\leadsto \color{blue}{\left(\left(x + y \cdot \left(1 - \log y\right)\right) - 0.5 \cdot \log y\right)} - z \]
  3. Taylor expanded in x around inf 57.4%

    \[\leadsto \color{blue}{x} - z \]
  4. Final simplification57.4%

    \[\leadsto x - z \]

Alternative 11: 30.7% accurate, 111.0× speedup?

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

\\
x
\end{array}
Derivation
  1. Initial program 99.8%

    \[\left(\left(x - \left(y + 0.5\right) \cdot \log y\right) + y\right) - z \]
  2. Step-by-step derivation
    1. associate--l+99.8%

      \[\leadsto \color{blue}{\left(x - \left(y + 0.5\right) \cdot \log y\right) + \left(y - z\right)} \]
    2. sub-neg99.8%

      \[\leadsto \color{blue}{\left(x + \left(-\left(y + 0.5\right) \cdot \log y\right)\right)} + \left(y - z\right) \]
    3. associate-+l+99.8%

      \[\leadsto \color{blue}{x + \left(\left(-\left(y + 0.5\right) \cdot \log y\right) + \left(y - z\right)\right)} \]
    4. *-commutative99.8%

      \[\leadsto x + \left(\left(-\color{blue}{\log y \cdot \left(y + 0.5\right)}\right) + \left(y - z\right)\right) \]
    5. distribute-rgt-neg-in99.8%

      \[\leadsto x + \left(\color{blue}{\log y \cdot \left(-\left(y + 0.5\right)\right)} + \left(y - z\right)\right) \]
    6. fma-def99.8%

      \[\leadsto x + \color{blue}{\mathsf{fma}\left(\log y, -\left(y + 0.5\right), y - z\right)} \]
    7. +-commutative99.8%

      \[\leadsto x + \mathsf{fma}\left(\log y, -\color{blue}{\left(0.5 + y\right)}, y - z\right) \]
    8. distribute-neg-in99.8%

      \[\leadsto x + \mathsf{fma}\left(\log y, \color{blue}{\left(-0.5\right) + \left(-y\right)}, y - z\right) \]
    9. unsub-neg99.8%

      \[\leadsto x + \mathsf{fma}\left(\log y, \color{blue}{\left(-0.5\right) - y}, y - z\right) \]
    10. metadata-eval99.8%

      \[\leadsto x + \mathsf{fma}\left(\log y, \color{blue}{-0.5} - y, y - z\right) \]
  3. Simplified99.8%

    \[\leadsto \color{blue}{x + \mathsf{fma}\left(\log y, -0.5 - y, y - z\right)} \]
  4. Taylor expanded in x around inf 28.1%

    \[\leadsto \color{blue}{x} \]
  5. Final simplification28.1%

    \[\leadsto x \]

Developer target: 99.8% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \left(\left(y + x\right) - z\right) - \left(y + 0.5\right) \cdot \log y \end{array} \]
(FPCore (x y z) :precision binary64 (- (- (+ y x) z) (* (+ y 0.5) (log y))))
double code(double x, double y, double z) {
	return ((y + x) - z) - ((y + 0.5) * log(y));
}
real(8) function code(x, y, z)
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    real(8), intent (in) :: z
    code = ((y + x) - z) - ((y + 0.5d0) * log(y))
end function
public static double code(double x, double y, double z) {
	return ((y + x) - z) - ((y + 0.5) * Math.log(y));
}
def code(x, y, z):
	return ((y + x) - z) - ((y + 0.5) * math.log(y))
function code(x, y, z)
	return Float64(Float64(Float64(y + x) - z) - Float64(Float64(y + 0.5) * log(y)))
end
function tmp = code(x, y, z)
	tmp = ((y + x) - z) - ((y + 0.5) * log(y));
end
code[x_, y_, z_] := N[(N[(N[(y + x), $MachinePrecision] - z), $MachinePrecision] - N[(N[(y + 0.5), $MachinePrecision] * N[Log[y], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\left(\left(y + x\right) - z\right) - \left(y + 0.5\right) \cdot \log y
\end{array}

Reproduce

?
herbie shell --seed 2023310 
(FPCore (x y z)
  :name "Numeric.SpecFunctions:stirlingError from math-functions-0.1.5.2"
  :precision binary64

  :herbie-target
  (- (- (+ y x) z) (* (+ y 0.5) (log y)))

  (- (+ (- x (* (+ y 0.5) (log y))) y) z))