Numeric.SpecFunctions:invIncompleteBetaWorker from math-functions-0.1.5.2, F

Percentage Accurate: 77.6% → 77.6%
Time: 2.6s
Alternatives: 7
Speedup: 1.0×

Specification

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

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

Sampling outcomes in binary64 precision:

Local Percentage Accuracy vs ?

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

Accuracy vs Speed?

Herbie found 7 alternatives:

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

Initial Program: 77.6% accurate, 1.0× speedup?

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

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

Alternative 1: 77.6% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \log \left(\frac{x}{x + y}\right)\\ t_1 := \frac{e^{x \cdot t\_0}}{x}\\ \mathbf{if}\;y \leq 2.9 \cdot 10^{+47}:\\ \;\;\;\;t\_1\\ \mathbf{elif}\;y \leq 1.42 \cdot 10^{+131}:\\ \;\;\;\;t\_0\\ \mathbf{else}:\\ \;\;\;\;t\_1\\ \end{array} \end{array} \]
(FPCore (x y)
 :precision binary64
 (let* ((t_0 (log (/ x (+ x y)))) (t_1 (/ (exp (* x t_0)) x)))
   (if (<= y 2.9e+47) t_1 (if (<= y 1.42e+131) t_0 t_1))))
double code(double x, double y) {
	double t_0 = log((x / (x + y)));
	double t_1 = exp((x * t_0)) / x;
	double tmp;
	if (y <= 2.9e+47) {
		tmp = t_1;
	} else if (y <= 1.42e+131) {
		tmp = t_0;
	} else {
		tmp = t_1;
	}
	return tmp;
}
real(8) function code(x, y)
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    real(8) :: t_0
    real(8) :: t_1
    real(8) :: tmp
    t_0 = log((x / (x + y)))
    t_1 = exp((x * t_0)) / x
    if (y <= 2.9d+47) then
        tmp = t_1
    else if (y <= 1.42d+131) then
        tmp = t_0
    else
        tmp = t_1
    end if
    code = tmp
end function
public static double code(double x, double y) {
	double t_0 = Math.log((x / (x + y)));
	double t_1 = Math.exp((x * t_0)) / x;
	double tmp;
	if (y <= 2.9e+47) {
		tmp = t_1;
	} else if (y <= 1.42e+131) {
		tmp = t_0;
	} else {
		tmp = t_1;
	}
	return tmp;
}
def code(x, y):
	t_0 = math.log((x / (x + y)))
	t_1 = math.exp((x * t_0)) / x
	tmp = 0
	if y <= 2.9e+47:
		tmp = t_1
	elif y <= 1.42e+131:
		tmp = t_0
	else:
		tmp = t_1
	return tmp
function code(x, y)
	t_0 = log(Float64(x / Float64(x + y)))
	t_1 = Float64(exp(Float64(x * t_0)) / x)
	tmp = 0.0
	if (y <= 2.9e+47)
		tmp = t_1;
	elseif (y <= 1.42e+131)
		tmp = t_0;
	else
		tmp = t_1;
	end
	return tmp
end
function tmp_2 = code(x, y)
	t_0 = log((x / (x + y)));
	t_1 = exp((x * t_0)) / x;
	tmp = 0.0;
	if (y <= 2.9e+47)
		tmp = t_1;
	elseif (y <= 1.42e+131)
		tmp = t_0;
	else
		tmp = t_1;
	end
	tmp_2 = tmp;
end
code[x_, y_] := Block[{t$95$0 = N[Log[N[(x / N[(x + y), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]}, Block[{t$95$1 = N[(N[Exp[N[(x * t$95$0), $MachinePrecision]], $MachinePrecision] / x), $MachinePrecision]}, If[LessEqual[y, 2.9e+47], t$95$1, If[LessEqual[y, 1.42e+131], t$95$0, t$95$1]]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \log \left(\frac{x}{x + y}\right)\\
t_1 := \frac{e^{x \cdot t\_0}}{x}\\
\mathbf{if}\;y \leq 2.9 \cdot 10^{+47}:\\
\;\;\;\;t\_1\\

\mathbf{elif}\;y \leq 1.42 \cdot 10^{+131}:\\
\;\;\;\;t\_0\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if y < 2.8999999999999998e47 or 1.42e131 < y

    1. Initial program 79.0%

      \[\frac{e^{x \cdot \log \left(\frac{x}{x + y}\right)}}{x} \]
    2. Add Preprocessing

    if 2.8999999999999998e47 < y < 1.42e131

    1. Initial program 12.1%

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

      \[\leadsto \color{blue}{\frac{1 + x \cdot \left(\log x + \left(\log \left(\frac{1}{y}\right) + x \cdot \left(\left(\frac{1}{2} \cdot {\left(\log x + \log \left(\frac{1}{y}\right)\right)}^{2} + x \cdot \left(-1 \cdot \frac{\log x + \log \left(\frac{1}{y}\right)}{y} + \left(\frac{1}{6} \cdot {\left(\log x + \log \left(\frac{1}{y}\right)\right)}^{3} + \frac{1}{2} \cdot \frac{1}{{y}^{2}}\right)\right)\right) - \frac{1}{y}\right)\right)\right)}{x}} \]
    4. Applied rewrites88.4%

      \[\leadsto \color{blue}{\log \left(\frac{x}{x + y}\right)} \]
  3. Recombined 2 regimes into one program.
  4. Add Preprocessing

Alternative 2: 61.9% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \frac{x}{x + y}\\ t_1 := x \cdot \log t\_0\\ \mathbf{if}\;y \leq -10500:\\ \;\;\;\;e^{\frac{x}{e^{t\_0}}}\\ \mathbf{elif}\;y \leq 5600:\\ \;\;\;\;\frac{t\_0}{x}\\ \mathbf{elif}\;y \leq 1.15 \cdot 10^{+135}:\\ \;\;\;\;t\_1\\ \mathbf{else}:\\ \;\;\;\;e^{t\_1}\\ \end{array} \end{array} \]
(FPCore (x y)
 :precision binary64
 (let* ((t_0 (/ x (+ x y))) (t_1 (* x (log t_0))))
   (if (<= y -10500.0)
     (exp (/ x (exp t_0)))
     (if (<= y 5600.0) (/ t_0 x) (if (<= y 1.15e+135) t_1 (exp t_1))))))
double code(double x, double y) {
	double t_0 = x / (x + y);
	double t_1 = x * log(t_0);
	double tmp;
	if (y <= -10500.0) {
		tmp = exp((x / exp(t_0)));
	} else if (y <= 5600.0) {
		tmp = t_0 / x;
	} else if (y <= 1.15e+135) {
		tmp = t_1;
	} else {
		tmp = exp(t_1);
	}
	return tmp;
}
real(8) function code(x, y)
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    real(8) :: t_0
    real(8) :: t_1
    real(8) :: tmp
    t_0 = x / (x + y)
    t_1 = x * log(t_0)
    if (y <= (-10500.0d0)) then
        tmp = exp((x / exp(t_0)))
    else if (y <= 5600.0d0) then
        tmp = t_0 / x
    else if (y <= 1.15d+135) then
        tmp = t_1
    else
        tmp = exp(t_1)
    end if
    code = tmp
end function
public static double code(double x, double y) {
	double t_0 = x / (x + y);
	double t_1 = x * Math.log(t_0);
	double tmp;
	if (y <= -10500.0) {
		tmp = Math.exp((x / Math.exp(t_0)));
	} else if (y <= 5600.0) {
		tmp = t_0 / x;
	} else if (y <= 1.15e+135) {
		tmp = t_1;
	} else {
		tmp = Math.exp(t_1);
	}
	return tmp;
}
def code(x, y):
	t_0 = x / (x + y)
	t_1 = x * math.log(t_0)
	tmp = 0
	if y <= -10500.0:
		tmp = math.exp((x / math.exp(t_0)))
	elif y <= 5600.0:
		tmp = t_0 / x
	elif y <= 1.15e+135:
		tmp = t_1
	else:
		tmp = math.exp(t_1)
	return tmp
function code(x, y)
	t_0 = Float64(x / Float64(x + y))
	t_1 = Float64(x * log(t_0))
	tmp = 0.0
	if (y <= -10500.0)
		tmp = exp(Float64(x / exp(t_0)));
	elseif (y <= 5600.0)
		tmp = Float64(t_0 / x);
	elseif (y <= 1.15e+135)
		tmp = t_1;
	else
		tmp = exp(t_1);
	end
	return tmp
end
function tmp_2 = code(x, y)
	t_0 = x / (x + y);
	t_1 = x * log(t_0);
	tmp = 0.0;
	if (y <= -10500.0)
		tmp = exp((x / exp(t_0)));
	elseif (y <= 5600.0)
		tmp = t_0 / x;
	elseif (y <= 1.15e+135)
		tmp = t_1;
	else
		tmp = exp(t_1);
	end
	tmp_2 = tmp;
end
code[x_, y_] := Block[{t$95$0 = N[(x / N[(x + y), $MachinePrecision]), $MachinePrecision]}, Block[{t$95$1 = N[(x * N[Log[t$95$0], $MachinePrecision]), $MachinePrecision]}, If[LessEqual[y, -10500.0], N[Exp[N[(x / N[Exp[t$95$0], $MachinePrecision]), $MachinePrecision]], $MachinePrecision], If[LessEqual[y, 5600.0], N[(t$95$0 / x), $MachinePrecision], If[LessEqual[y, 1.15e+135], t$95$1, N[Exp[t$95$1], $MachinePrecision]]]]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \frac{x}{x + y}\\
t_1 := x \cdot \log t\_0\\
\mathbf{if}\;y \leq -10500:\\
\;\;\;\;e^{\frac{x}{e^{t\_0}}}\\

\mathbf{elif}\;y \leq 5600:\\
\;\;\;\;\frac{t\_0}{x}\\

\mathbf{elif}\;y \leq 1.15 \cdot 10^{+135}:\\
\;\;\;\;t\_1\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 4 regimes
  2. if y < -10500

    1. Initial program 44.8%

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

      \[\leadsto \color{blue}{\frac{1 + x \cdot \left(\log x + \log \left(\frac{1}{y}\right)\right)}{x}} \]
    4. Applied rewrites7.0%

      \[\leadsto \color{blue}{e^{x \cdot \log \left(\frac{x}{x + y}\right)}} \]
    5. Taylor expanded in x around 0

      \[\leadsto e^{x \cdot \left(\log x + \left(\log \left(\frac{1}{y}\right) + -1 \cdot \frac{x}{y}\right)\right)} \]
    6. Applied rewrites1.3%

      \[\leadsto e^{\frac{x}{x + y}} \]
    7. Taylor expanded in x around 0

      \[\leadsto e^{\frac{x}{y}} \]
    8. Applied rewrites19.4%

      \[\leadsto e^{\frac{x}{e^{\frac{x}{x + y}}}} \]

    if -10500 < y < 5600

    1. Initial program 98.4%

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

      \[\leadsto \frac{\color{blue}{1}}{x} \]
    4. Applied rewrites84.2%

      \[\leadsto \frac{\color{blue}{\frac{x}{x + y}}}{x} \]

    if 5600 < y < 1.1500000000000001e135

    1. Initial program 31.8%

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

      \[\leadsto \color{blue}{\frac{1 + x \cdot \left(\log x + \left(\log \left(\frac{1}{y}\right) + x \cdot \left(\frac{1}{2} \cdot {\left(\log x + \log \left(\frac{1}{y}\right)\right)}^{2} - \frac{1}{y}\right)\right)\right)}{x}} \]
    4. Applied rewrites70.6%

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

    if 1.1500000000000001e135 < y

    1. Initial program 54.8%

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

      \[\leadsto \color{blue}{\frac{1 + x \cdot \left(\log x + \log \left(\frac{1}{y}\right)\right)}{x}} \]
    4. Applied rewrites40.2%

      \[\leadsto \color{blue}{e^{x \cdot \log \left(\frac{x}{x + y}\right)}} \]
  3. Recombined 4 regimes into one program.
  4. Add Preprocessing

Alternative 3: 58.4% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \frac{x}{x + y}\\ t_1 := x \cdot \log t\_0\\ \mathbf{if}\;y \leq 5600:\\ \;\;\;\;\frac{t\_0}{x}\\ \mathbf{elif}\;y \leq 1.15 \cdot 10^{+135}:\\ \;\;\;\;t\_1\\ \mathbf{else}:\\ \;\;\;\;e^{t\_1}\\ \end{array} \end{array} \]
(FPCore (x y)
 :precision binary64
 (let* ((t_0 (/ x (+ x y))) (t_1 (* x (log t_0))))
   (if (<= y 5600.0) (/ t_0 x) (if (<= y 1.15e+135) t_1 (exp t_1)))))
double code(double x, double y) {
	double t_0 = x / (x + y);
	double t_1 = x * log(t_0);
	double tmp;
	if (y <= 5600.0) {
		tmp = t_0 / x;
	} else if (y <= 1.15e+135) {
		tmp = t_1;
	} else {
		tmp = exp(t_1);
	}
	return tmp;
}
real(8) function code(x, y)
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    real(8) :: t_0
    real(8) :: t_1
    real(8) :: tmp
    t_0 = x / (x + y)
    t_1 = x * log(t_0)
    if (y <= 5600.0d0) then
        tmp = t_0 / x
    else if (y <= 1.15d+135) then
        tmp = t_1
    else
        tmp = exp(t_1)
    end if
    code = tmp
end function
public static double code(double x, double y) {
	double t_0 = x / (x + y);
	double t_1 = x * Math.log(t_0);
	double tmp;
	if (y <= 5600.0) {
		tmp = t_0 / x;
	} else if (y <= 1.15e+135) {
		tmp = t_1;
	} else {
		tmp = Math.exp(t_1);
	}
	return tmp;
}
def code(x, y):
	t_0 = x / (x + y)
	t_1 = x * math.log(t_0)
	tmp = 0
	if y <= 5600.0:
		tmp = t_0 / x
	elif y <= 1.15e+135:
		tmp = t_1
	else:
		tmp = math.exp(t_1)
	return tmp
function code(x, y)
	t_0 = Float64(x / Float64(x + y))
	t_1 = Float64(x * log(t_0))
	tmp = 0.0
	if (y <= 5600.0)
		tmp = Float64(t_0 / x);
	elseif (y <= 1.15e+135)
		tmp = t_1;
	else
		tmp = exp(t_1);
	end
	return tmp
end
function tmp_2 = code(x, y)
	t_0 = x / (x + y);
	t_1 = x * log(t_0);
	tmp = 0.0;
	if (y <= 5600.0)
		tmp = t_0 / x;
	elseif (y <= 1.15e+135)
		tmp = t_1;
	else
		tmp = exp(t_1);
	end
	tmp_2 = tmp;
end
code[x_, y_] := Block[{t$95$0 = N[(x / N[(x + y), $MachinePrecision]), $MachinePrecision]}, Block[{t$95$1 = N[(x * N[Log[t$95$0], $MachinePrecision]), $MachinePrecision]}, If[LessEqual[y, 5600.0], N[(t$95$0 / x), $MachinePrecision], If[LessEqual[y, 1.15e+135], t$95$1, N[Exp[t$95$1], $MachinePrecision]]]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \frac{x}{x + y}\\
t_1 := x \cdot \log t\_0\\
\mathbf{if}\;y \leq 5600:\\
\;\;\;\;\frac{t\_0}{x}\\

\mathbf{elif}\;y \leq 1.15 \cdot 10^{+135}:\\
\;\;\;\;t\_1\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if y < 5600

    1. Initial program 84.7%

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

      \[\leadsto \frac{\color{blue}{1}}{x} \]
    4. Applied rewrites63.4%

      \[\leadsto \frac{\color{blue}{\frac{x}{x + y}}}{x} \]

    if 5600 < y < 1.1500000000000001e135

    1. Initial program 31.8%

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

      \[\leadsto \color{blue}{\frac{1 + x \cdot \left(\log x + \left(\log \left(\frac{1}{y}\right) + x \cdot \left(\frac{1}{2} \cdot {\left(\log x + \log \left(\frac{1}{y}\right)\right)}^{2} - \frac{1}{y}\right)\right)\right)}{x}} \]
    4. Applied rewrites70.6%

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

    if 1.1500000000000001e135 < y

    1. Initial program 54.8%

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

      \[\leadsto \color{blue}{\frac{1 + x \cdot \left(\log x + \log \left(\frac{1}{y}\right)\right)}{x}} \]
    4. Applied rewrites40.2%

      \[\leadsto \color{blue}{e^{x \cdot \log \left(\frac{x}{x + y}\right)}} \]
  3. Recombined 3 regimes into one program.
  4. Add Preprocessing

Alternative 4: 56.4% accurate, 1.9× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \frac{x}{x + y}\\ \mathbf{if}\;y \leq 5600:\\ \;\;\;\;\frac{t\_0}{x}\\ \mathbf{else}:\\ \;\;\;\;\log t\_0\\ \end{array} \end{array} \]
(FPCore (x y)
 :precision binary64
 (let* ((t_0 (/ x (+ x y)))) (if (<= y 5600.0) (/ t_0 x) (log t_0))))
double code(double x, double y) {
	double t_0 = x / (x + y);
	double tmp;
	if (y <= 5600.0) {
		tmp = t_0 / x;
	} else {
		tmp = log(t_0);
	}
	return tmp;
}
real(8) function code(x, y)
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    real(8) :: t_0
    real(8) :: tmp
    t_0 = x / (x + y)
    if (y <= 5600.0d0) then
        tmp = t_0 / x
    else
        tmp = log(t_0)
    end if
    code = tmp
end function
public static double code(double x, double y) {
	double t_0 = x / (x + y);
	double tmp;
	if (y <= 5600.0) {
		tmp = t_0 / x;
	} else {
		tmp = Math.log(t_0);
	}
	return tmp;
}
def code(x, y):
	t_0 = x / (x + y)
	tmp = 0
	if y <= 5600.0:
		tmp = t_0 / x
	else:
		tmp = math.log(t_0)
	return tmp
function code(x, y)
	t_0 = Float64(x / Float64(x + y))
	tmp = 0.0
	if (y <= 5600.0)
		tmp = Float64(t_0 / x);
	else
		tmp = log(t_0);
	end
	return tmp
end
function tmp_2 = code(x, y)
	t_0 = x / (x + y);
	tmp = 0.0;
	if (y <= 5600.0)
		tmp = t_0 / x;
	else
		tmp = log(t_0);
	end
	tmp_2 = tmp;
end
code[x_, y_] := Block[{t$95$0 = N[(x / N[(x + y), $MachinePrecision]), $MachinePrecision]}, If[LessEqual[y, 5600.0], N[(t$95$0 / x), $MachinePrecision], N[Log[t$95$0], $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \frac{x}{x + y}\\
\mathbf{if}\;y \leq 5600:\\
\;\;\;\;\frac{t\_0}{x}\\

\mathbf{else}:\\
\;\;\;\;\log t\_0\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if y < 5600

    1. Initial program 84.7%

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

      \[\leadsto \frac{\color{blue}{1}}{x} \]
    4. Applied rewrites63.4%

      \[\leadsto \frac{\color{blue}{\frac{x}{x + y}}}{x} \]

    if 5600 < y

    1. Initial program 44.0%

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

      \[\leadsto \color{blue}{\frac{1 + x \cdot \left(\log x + \left(\log \left(\frac{1}{y}\right) + x \cdot \left(\left(\frac{1}{2} \cdot {\left(\log x + \log \left(\frac{1}{y}\right)\right)}^{2} + x \cdot \left(-1 \cdot \frac{\log x + \log \left(\frac{1}{y}\right)}{y} + \left(\frac{1}{6} \cdot {\left(\log x + \log \left(\frac{1}{y}\right)\right)}^{3} + \frac{1}{2} \cdot \frac{1}{{y}^{2}}\right)\right)\right) - \frac{1}{y}\right)\right)\right)}{x}} \]
    4. Applied rewrites43.2%

      \[\leadsto \color{blue}{\log \left(\frac{x}{x + y}\right)} \]
  3. Recombined 2 regimes into one program.
  4. Add Preprocessing

Alternative 5: 50.0% accurate, 8.9× speedup?

\[\begin{array}{l} \\ \frac{\frac{x}{x + y}}{x} \end{array} \]
(FPCore (x y) :precision binary64 (/ (/ x (+ x y)) x))
double code(double x, double y) {
	return (x / (x + y)) / x;
}
real(8) function code(x, y)
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    code = (x / (x + y)) / x
end function
public static double code(double x, double y) {
	return (x / (x + y)) / x;
}
def code(x, y):
	return (x / (x + y)) / x
function code(x, y)
	return Float64(Float64(x / Float64(x + y)) / x)
end
function tmp = code(x, y)
	tmp = (x / (x + y)) / x;
end
code[x_, y_] := N[(N[(x / N[(x + y), $MachinePrecision]), $MachinePrecision] / x), $MachinePrecision]
\begin{array}{l}

\\
\frac{\frac{x}{x + y}}{x}
\end{array}
Derivation
  1. Initial program 74.5%

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

    \[\leadsto \frac{\color{blue}{1}}{x} \]
  4. Applied rewrites48.9%

    \[\leadsto \frac{\color{blue}{\frac{x}{x + y}}}{x} \]
  5. Add Preprocessing

Alternative 6: 4.5% accurate, 8.9× speedup?

\[\begin{array}{l} \\ \frac{x}{\frac{x}{x + y}} \end{array} \]
(FPCore (x y) :precision binary64 (/ x (/ x (+ x y))))
double code(double x, double y) {
	return x / (x / (x + y));
}
real(8) function code(x, y)
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    code = x / (x / (x + y))
end function
public static double code(double x, double y) {
	return x / (x / (x + y));
}
def code(x, y):
	return x / (x / (x + y))
function code(x, y)
	return Float64(x / Float64(x / Float64(x + y)))
end
function tmp = code(x, y)
	tmp = x / (x / (x + y));
end
code[x_, y_] := N[(x / N[(x / N[(x + y), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{x}{\frac{x}{x + y}}
\end{array}
Derivation
  1. Initial program 74.5%

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

    \[\leadsto \color{blue}{\frac{1 + x \cdot \left(\log x + \left(\log \left(\frac{1}{y}\right) + x \cdot \left(\frac{1}{2} \cdot {\left(\log x + \log \left(\frac{1}{y}\right)\right)}^{2} - \frac{1}{y}\right)\right)\right)}{x}} \]
  4. Applied rewrites13.2%

    \[\leadsto \color{blue}{x \cdot \log \left(\frac{x}{x + y}\right)} \]
  5. Taylor expanded in x around 0

    \[\leadsto x \cdot \color{blue}{\left(\log x + \left(\log \left(\frac{1}{y}\right) + -1 \cdot \frac{x}{y}\right)\right)} \]
  6. Applied rewrites3.4%

    \[\leadsto \frac{x}{\color{blue}{x + y}} \]
  7. Taylor expanded in x around 0

    \[\leadsto \frac{x}{x + y} \]
  8. Applied rewrites3.8%

    \[\leadsto \frac{x}{e^{\frac{\frac{x}{x + y}}{x}}} \]
  9. Taylor expanded in x around 0

    \[\leadsto \frac{x}{x + y} \]
  10. Applied rewrites4.4%

    \[\leadsto \frac{x}{\frac{x}{x + y}} \]
  11. Add Preprocessing

Alternative 7: 4.5% accurate, 57.8× speedup?

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

\\
x + y
\end{array}
Derivation
  1. Initial program 74.5%

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

    \[\leadsto \color{blue}{\frac{1 + x \cdot \left(\log x + \log \left(\frac{1}{y}\right)\right)}{x}} \]
  4. Applied rewrites10.9%

    \[\leadsto \color{blue}{e^{x \cdot \log \left(\frac{x}{x + y}\right)}} \]
  5. Taylor expanded in x around 0

    \[\leadsto 1 + \color{blue}{x \cdot \left(\log x + \left(\log \left(\frac{1}{y}\right) + x \cdot \left(\frac{1}{2} \cdot {\left(\log x + \log \left(\frac{1}{y}\right)\right)}^{2} - \frac{1}{y}\right)\right)\right)} \]
  6. Applied rewrites4.4%

    \[\leadsto x + \color{blue}{y} \]
  7. Add Preprocessing

Developer Target 1: 77.9% accurate, 0.7× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \frac{e^{\frac{-1}{y}}}{x}\\ t_1 := \frac{{\left(\frac{x}{y + x}\right)}^{x}}{x}\\ \mathbf{if}\;y < -3.7311844206647956 \cdot 10^{+94}:\\ \;\;\;\;t\_0\\ \mathbf{elif}\;y < 2.817959242728288 \cdot 10^{+37}:\\ \;\;\;\;t\_1\\ \mathbf{elif}\;y < 2.347387415166998 \cdot 10^{+178}:\\ \;\;\;\;\log \left(e^{t\_1}\right)\\ \mathbf{else}:\\ \;\;\;\;t\_0\\ \end{array} \end{array} \]
(FPCore (x y)
 :precision binary64
 (let* ((t_0 (/ (exp (/ -1.0 y)) x)) (t_1 (/ (pow (/ x (+ y x)) x) x)))
   (if (< y -3.7311844206647956e+94)
     t_0
     (if (< y 2.817959242728288e+37)
       t_1
       (if (< y 2.347387415166998e+178) (log (exp t_1)) t_0)))))
double code(double x, double y) {
	double t_0 = exp((-1.0 / y)) / x;
	double t_1 = pow((x / (y + x)), x) / x;
	double tmp;
	if (y < -3.7311844206647956e+94) {
		tmp = t_0;
	} else if (y < 2.817959242728288e+37) {
		tmp = t_1;
	} else if (y < 2.347387415166998e+178) {
		tmp = log(exp(t_1));
	} else {
		tmp = t_0;
	}
	return tmp;
}
real(8) function code(x, y)
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    real(8) :: t_0
    real(8) :: t_1
    real(8) :: tmp
    t_0 = exp(((-1.0d0) / y)) / x
    t_1 = ((x / (y + x)) ** x) / x
    if (y < (-3.7311844206647956d+94)) then
        tmp = t_0
    else if (y < 2.817959242728288d+37) then
        tmp = t_1
    else if (y < 2.347387415166998d+178) then
        tmp = log(exp(t_1))
    else
        tmp = t_0
    end if
    code = tmp
end function
public static double code(double x, double y) {
	double t_0 = Math.exp((-1.0 / y)) / x;
	double t_1 = Math.pow((x / (y + x)), x) / x;
	double tmp;
	if (y < -3.7311844206647956e+94) {
		tmp = t_0;
	} else if (y < 2.817959242728288e+37) {
		tmp = t_1;
	} else if (y < 2.347387415166998e+178) {
		tmp = Math.log(Math.exp(t_1));
	} else {
		tmp = t_0;
	}
	return tmp;
}
def code(x, y):
	t_0 = math.exp((-1.0 / y)) / x
	t_1 = math.pow((x / (y + x)), x) / x
	tmp = 0
	if y < -3.7311844206647956e+94:
		tmp = t_0
	elif y < 2.817959242728288e+37:
		tmp = t_1
	elif y < 2.347387415166998e+178:
		tmp = math.log(math.exp(t_1))
	else:
		tmp = t_0
	return tmp
function code(x, y)
	t_0 = Float64(exp(Float64(-1.0 / y)) / x)
	t_1 = Float64((Float64(x / Float64(y + x)) ^ x) / x)
	tmp = 0.0
	if (y < -3.7311844206647956e+94)
		tmp = t_0;
	elseif (y < 2.817959242728288e+37)
		tmp = t_1;
	elseif (y < 2.347387415166998e+178)
		tmp = log(exp(t_1));
	else
		tmp = t_0;
	end
	return tmp
end
function tmp_2 = code(x, y)
	t_0 = exp((-1.0 / y)) / x;
	t_1 = ((x / (y + x)) ^ x) / x;
	tmp = 0.0;
	if (y < -3.7311844206647956e+94)
		tmp = t_0;
	elseif (y < 2.817959242728288e+37)
		tmp = t_1;
	elseif (y < 2.347387415166998e+178)
		tmp = log(exp(t_1));
	else
		tmp = t_0;
	end
	tmp_2 = tmp;
end
code[x_, y_] := Block[{t$95$0 = N[(N[Exp[N[(-1.0 / y), $MachinePrecision]], $MachinePrecision] / x), $MachinePrecision]}, Block[{t$95$1 = N[(N[Power[N[(x / N[(y + x), $MachinePrecision]), $MachinePrecision], x], $MachinePrecision] / x), $MachinePrecision]}, If[Less[y, -3.7311844206647956e+94], t$95$0, If[Less[y, 2.817959242728288e+37], t$95$1, If[Less[y, 2.347387415166998e+178], N[Log[N[Exp[t$95$1], $MachinePrecision]], $MachinePrecision], t$95$0]]]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \frac{e^{\frac{-1}{y}}}{x}\\
t_1 := \frac{{\left(\frac{x}{y + x}\right)}^{x}}{x}\\
\mathbf{if}\;y < -3.7311844206647956 \cdot 10^{+94}:\\
\;\;\;\;t\_0\\

\mathbf{elif}\;y < 2.817959242728288 \cdot 10^{+37}:\\
\;\;\;\;t\_1\\

\mathbf{elif}\;y < 2.347387415166998 \cdot 10^{+178}:\\
\;\;\;\;\log \left(e^{t\_1}\right)\\

\mathbf{else}:\\
\;\;\;\;t\_0\\


\end{array}
\end{array}

Reproduce

?
herbie shell --seed 2024321 
(FPCore (x y)
  :name "Numeric.SpecFunctions:invIncompleteBetaWorker from math-functions-0.1.5.2, F"
  :precision binary64
  :pre (TRUE)

  :alt
  (! :herbie-platform default (if (< y -37311844206647956000000000000000000000000000000000000000000000000000000000000000000000000000000) (/ (exp (/ -1 y)) x) (if (< y 28179592427282880000000000000000000000) (/ (pow (/ x (+ y x)) x) x) (if (< y 23473874151669980000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000) (log (exp (/ (pow (/ x (+ y x)) x) x))) (/ (exp (/ -1 y)) x)))))

  (/ (exp (* x (log (/ x (+ x y))))) x))