Octave 3.8, jcobi/1

Percentage Accurate: 75.5% → 99.4%
Time: 5.5s
Alternatives: 8
Speedup: 1.2×

Specification

?
\[\alpha > -1 \land \beta > -1\]
\[\begin{array}{l} \\ \frac{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1}{2} \end{array} \]
(FPCore (alpha beta)
 :precision binary64
 (/ (+ (/ (- beta alpha) (+ (+ alpha beta) 2.0)) 1.0) 2.0))
double code(double alpha, double beta) {
	return (((beta - alpha) / ((alpha + beta) + 2.0)) + 1.0) / 2.0;
}
real(8) function code(alpha, beta)
    real(8), intent (in) :: alpha
    real(8), intent (in) :: beta
    code = (((beta - alpha) / ((alpha + beta) + 2.0d0)) + 1.0d0) / 2.0d0
end function
public static double code(double alpha, double beta) {
	return (((beta - alpha) / ((alpha + beta) + 2.0)) + 1.0) / 2.0;
}
def code(alpha, beta):
	return (((beta - alpha) / ((alpha + beta) + 2.0)) + 1.0) / 2.0
function code(alpha, beta)
	return Float64(Float64(Float64(Float64(beta - alpha) / Float64(Float64(alpha + beta) + 2.0)) + 1.0) / 2.0)
end
function tmp = code(alpha, beta)
	tmp = (((beta - alpha) / ((alpha + beta) + 2.0)) + 1.0) / 2.0;
end
code[alpha_, beta_] := N[(N[(N[(N[(beta - alpha), $MachinePrecision] / N[(N[(alpha + beta), $MachinePrecision] + 2.0), $MachinePrecision]), $MachinePrecision] + 1.0), $MachinePrecision] / 2.0), $MachinePrecision]
\begin{array}{l}

\\
\frac{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1}{2}
\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 8 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: 75.5% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \frac{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1}{2} \end{array} \]
(FPCore (alpha beta)
 :precision binary64
 (/ (+ (/ (- beta alpha) (+ (+ alpha beta) 2.0)) 1.0) 2.0))
double code(double alpha, double beta) {
	return (((beta - alpha) / ((alpha + beta) + 2.0)) + 1.0) / 2.0;
}
real(8) function code(alpha, beta)
    real(8), intent (in) :: alpha
    real(8), intent (in) :: beta
    code = (((beta - alpha) / ((alpha + beta) + 2.0d0)) + 1.0d0) / 2.0d0
end function
public static double code(double alpha, double beta) {
	return (((beta - alpha) / ((alpha + beta) + 2.0)) + 1.0) / 2.0;
}
def code(alpha, beta):
	return (((beta - alpha) / ((alpha + beta) + 2.0)) + 1.0) / 2.0
function code(alpha, beta)
	return Float64(Float64(Float64(Float64(beta - alpha) / Float64(Float64(alpha + beta) + 2.0)) + 1.0) / 2.0)
end
function tmp = code(alpha, beta)
	tmp = (((beta - alpha) / ((alpha + beta) + 2.0)) + 1.0) / 2.0;
end
code[alpha_, beta_] := N[(N[(N[(N[(beta - alpha), $MachinePrecision] / N[(N[(alpha + beta), $MachinePrecision] + 2.0), $MachinePrecision]), $MachinePrecision] + 1.0), $MachinePrecision] / 2.0), $MachinePrecision]
\begin{array}{l}

\\
\frac{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1}{2}
\end{array}

Alternative 1: 99.4% accurate, 0.1× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;\frac{\beta - \alpha}{\left(\beta + \alpha\right) + 2} \leq -1:\\ \;\;\;\;\frac{\beta + 1}{\alpha}\\ \mathbf{else}:\\ \;\;\;\;\frac{e^{\mathsf{log1p}\left(\frac{\beta - \alpha}{\beta + \left(\alpha + 2\right)}\right)}}{2}\\ \end{array} \end{array} \]
(FPCore (alpha beta)
 :precision binary64
 (if (<= (/ (- beta alpha) (+ (+ beta alpha) 2.0)) -1.0)
   (/ (+ beta 1.0) alpha)
   (/ (exp (log1p (/ (- beta alpha) (+ beta (+ alpha 2.0))))) 2.0)))
double code(double alpha, double beta) {
	double tmp;
	if (((beta - alpha) / ((beta + alpha) + 2.0)) <= -1.0) {
		tmp = (beta + 1.0) / alpha;
	} else {
		tmp = exp(log1p(((beta - alpha) / (beta + (alpha + 2.0))))) / 2.0;
	}
	return tmp;
}
public static double code(double alpha, double beta) {
	double tmp;
	if (((beta - alpha) / ((beta + alpha) + 2.0)) <= -1.0) {
		tmp = (beta + 1.0) / alpha;
	} else {
		tmp = Math.exp(Math.log1p(((beta - alpha) / (beta + (alpha + 2.0))))) / 2.0;
	}
	return tmp;
}
def code(alpha, beta):
	tmp = 0
	if ((beta - alpha) / ((beta + alpha) + 2.0)) <= -1.0:
		tmp = (beta + 1.0) / alpha
	else:
		tmp = math.exp(math.log1p(((beta - alpha) / (beta + (alpha + 2.0))))) / 2.0
	return tmp
function code(alpha, beta)
	tmp = 0.0
	if (Float64(Float64(beta - alpha) / Float64(Float64(beta + alpha) + 2.0)) <= -1.0)
		tmp = Float64(Float64(beta + 1.0) / alpha);
	else
		tmp = Float64(exp(log1p(Float64(Float64(beta - alpha) / Float64(beta + Float64(alpha + 2.0))))) / 2.0);
	end
	return tmp
end
code[alpha_, beta_] := If[LessEqual[N[(N[(beta - alpha), $MachinePrecision] / N[(N[(beta + alpha), $MachinePrecision] + 2.0), $MachinePrecision]), $MachinePrecision], -1.0], N[(N[(beta + 1.0), $MachinePrecision] / alpha), $MachinePrecision], N[(N[Exp[N[Log[1 + N[(N[(beta - alpha), $MachinePrecision] / N[(beta + N[(alpha + 2.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]], $MachinePrecision] / 2.0), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;\frac{\beta - \alpha}{\left(\beta + \alpha\right) + 2} \leq -1:\\
\;\;\;\;\frac{\beta + 1}{\alpha}\\

\mathbf{else}:\\
\;\;\;\;\frac{e^{\mathsf{log1p}\left(\frac{\beta - \alpha}{\beta + \left(\alpha + 2\right)}\right)}}{2}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (/.f64 (-.f64 beta alpha) (+.f64 (+.f64 alpha beta) 2)) < -1

    1. Initial program 5.6%

      \[\frac{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1}{2} \]
    2. Step-by-step derivation
      1. +-commutative5.6%

        \[\leadsto \frac{\frac{\beta - \alpha}{\color{blue}{\left(\beta + \alpha\right)} + 2} + 1}{2} \]
    3. Simplified5.6%

      \[\leadsto \color{blue}{\frac{\frac{\beta - \alpha}{\left(\beta + \alpha\right) + 2} + 1}{2}} \]
    4. Taylor expanded in alpha around inf 100.0%

      \[\leadsto \frac{\color{blue}{\frac{2 + 2 \cdot \beta}{\alpha}}}{2} \]
    5. Taylor expanded in alpha around 0 100.0%

      \[\leadsto \color{blue}{0.5 \cdot \frac{2 + 2 \cdot \beta}{\alpha}} \]
    6. Step-by-step derivation
      1. metadata-eval100.0%

        \[\leadsto \color{blue}{\frac{1}{2}} \cdot \frac{2 + 2 \cdot \beta}{\alpha} \]
      2. +-commutative100.0%

        \[\leadsto \frac{1}{2} \cdot \frac{\color{blue}{2 \cdot \beta + 2}}{\alpha} \]
      3. fma-udef100.0%

        \[\leadsto \frac{1}{2} \cdot \frac{\color{blue}{\mathsf{fma}\left(2, \beta, 2\right)}}{\alpha} \]
      4. times-frac100.0%

        \[\leadsto \color{blue}{\frac{1 \cdot \mathsf{fma}\left(2, \beta, 2\right)}{2 \cdot \alpha}} \]
      5. *-lft-identity100.0%

        \[\leadsto \frac{\color{blue}{\mathsf{fma}\left(2, \beta, 2\right)}}{2 \cdot \alpha} \]
      6. fma-udef100.0%

        \[\leadsto \frac{\color{blue}{2 \cdot \beta + 2}}{2 \cdot \alpha} \]
      7. *-commutative100.0%

        \[\leadsto \frac{\color{blue}{\beta \cdot 2} + 2}{2 \cdot \alpha} \]
      8. distribute-lft1-in100.0%

        \[\leadsto \frac{\color{blue}{\left(\beta + 1\right) \cdot 2}}{2 \cdot \alpha} \]
      9. *-commutative100.0%

        \[\leadsto \frac{\left(\beta + 1\right) \cdot 2}{\color{blue}{\alpha \cdot 2}} \]
      10. times-frac100.0%

        \[\leadsto \color{blue}{\frac{\beta + 1}{\alpha} \cdot \frac{2}{2}} \]
      11. metadata-eval100.0%

        \[\leadsto \frac{\beta + 1}{\alpha} \cdot \color{blue}{1} \]
    7. Simplified100.0%

      \[\leadsto \color{blue}{\frac{\beta + 1}{\alpha} \cdot 1} \]

    if -1 < (/.f64 (-.f64 beta alpha) (+.f64 (+.f64 alpha beta) 2))

    1. Initial program 100.0%

      \[\frac{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1}{2} \]
    2. Step-by-step derivation
      1. +-commutative100.0%

        \[\leadsto \frac{\frac{\beta - \alpha}{\color{blue}{\left(\beta + \alpha\right)} + 2} + 1}{2} \]
    3. Simplified100.0%

      \[\leadsto \color{blue}{\frac{\frac{\beta - \alpha}{\left(\beta + \alpha\right) + 2} + 1}{2}} \]
    4. Step-by-step derivation
      1. add-exp-log100.0%

        \[\leadsto \frac{\color{blue}{e^{\log \left(\frac{\beta - \alpha}{\left(\beta + \alpha\right) + 2} + 1\right)}}}{2} \]
      2. +-commutative100.0%

        \[\leadsto \frac{e^{\log \color{blue}{\left(1 + \frac{\beta - \alpha}{\left(\beta + \alpha\right) + 2}\right)}}}{2} \]
      3. log1p-udef100.0%

        \[\leadsto \frac{e^{\color{blue}{\mathsf{log1p}\left(\frac{\beta - \alpha}{\left(\beta + \alpha\right) + 2}\right)}}}{2} \]
      4. associate-+l+100.0%

        \[\leadsto \frac{e^{\mathsf{log1p}\left(\frac{\beta - \alpha}{\color{blue}{\beta + \left(\alpha + 2\right)}}\right)}}{2} \]
    5. Applied egg-rr100.0%

      \[\leadsto \frac{\color{blue}{e^{\mathsf{log1p}\left(\frac{\beta - \alpha}{\beta + \left(\alpha + 2\right)}\right)}}}{2} \]
    6. Step-by-step derivation
      1. +-commutative100.0%

        \[\leadsto \frac{e^{\mathsf{log1p}\left(\frac{\beta - \alpha}{\color{blue}{\left(\alpha + 2\right) + \beta}}\right)}}{2} \]
    7. Simplified100.0%

      \[\leadsto \frac{\color{blue}{e^{\mathsf{log1p}\left(\frac{\beta - \alpha}{\left(\alpha + 2\right) + \beta}\right)}}}{2} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification100.0%

    \[\leadsto \begin{array}{l} \mathbf{if}\;\frac{\beta - \alpha}{\left(\beta + \alpha\right) + 2} \leq -1:\\ \;\;\;\;\frac{\beta + 1}{\alpha}\\ \mathbf{else}:\\ \;\;\;\;\frac{e^{\mathsf{log1p}\left(\frac{\beta - \alpha}{\beta + \left(\alpha + 2\right)}\right)}}{2}\\ \end{array} \]

Alternative 2: 99.4% accurate, 0.6× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \frac{\beta - \alpha}{\left(\beta + \alpha\right) + 2}\\ \mathbf{if}\;t_0 \leq -1:\\ \;\;\;\;\frac{\beta + 1}{\alpha}\\ \mathbf{else}:\\ \;\;\;\;\frac{t_0 + 1}{2}\\ \end{array} \end{array} \]
(FPCore (alpha beta)
 :precision binary64
 (let* ((t_0 (/ (- beta alpha) (+ (+ beta alpha) 2.0))))
   (if (<= t_0 -1.0) (/ (+ beta 1.0) alpha) (/ (+ t_0 1.0) 2.0))))
double code(double alpha, double beta) {
	double t_0 = (beta - alpha) / ((beta + alpha) + 2.0);
	double tmp;
	if (t_0 <= -1.0) {
		tmp = (beta + 1.0) / alpha;
	} else {
		tmp = (t_0 + 1.0) / 2.0;
	}
	return tmp;
}
real(8) function code(alpha, beta)
    real(8), intent (in) :: alpha
    real(8), intent (in) :: beta
    real(8) :: t_0
    real(8) :: tmp
    t_0 = (beta - alpha) / ((beta + alpha) + 2.0d0)
    if (t_0 <= (-1.0d0)) then
        tmp = (beta + 1.0d0) / alpha
    else
        tmp = (t_0 + 1.0d0) / 2.0d0
    end if
    code = tmp
end function
public static double code(double alpha, double beta) {
	double t_0 = (beta - alpha) / ((beta + alpha) + 2.0);
	double tmp;
	if (t_0 <= -1.0) {
		tmp = (beta + 1.0) / alpha;
	} else {
		tmp = (t_0 + 1.0) / 2.0;
	}
	return tmp;
}
def code(alpha, beta):
	t_0 = (beta - alpha) / ((beta + alpha) + 2.0)
	tmp = 0
	if t_0 <= -1.0:
		tmp = (beta + 1.0) / alpha
	else:
		tmp = (t_0 + 1.0) / 2.0
	return tmp
function code(alpha, beta)
	t_0 = Float64(Float64(beta - alpha) / Float64(Float64(beta + alpha) + 2.0))
	tmp = 0.0
	if (t_0 <= -1.0)
		tmp = Float64(Float64(beta + 1.0) / alpha);
	else
		tmp = Float64(Float64(t_0 + 1.0) / 2.0);
	end
	return tmp
end
function tmp_2 = code(alpha, beta)
	t_0 = (beta - alpha) / ((beta + alpha) + 2.0);
	tmp = 0.0;
	if (t_0 <= -1.0)
		tmp = (beta + 1.0) / alpha;
	else
		tmp = (t_0 + 1.0) / 2.0;
	end
	tmp_2 = tmp;
end
code[alpha_, beta_] := Block[{t$95$0 = N[(N[(beta - alpha), $MachinePrecision] / N[(N[(beta + alpha), $MachinePrecision] + 2.0), $MachinePrecision]), $MachinePrecision]}, If[LessEqual[t$95$0, -1.0], N[(N[(beta + 1.0), $MachinePrecision] / alpha), $MachinePrecision], N[(N[(t$95$0 + 1.0), $MachinePrecision] / 2.0), $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \frac{\beta - \alpha}{\left(\beta + \alpha\right) + 2}\\
\mathbf{if}\;t_0 \leq -1:\\
\;\;\;\;\frac{\beta + 1}{\alpha}\\

\mathbf{else}:\\
\;\;\;\;\frac{t_0 + 1}{2}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (/.f64 (-.f64 beta alpha) (+.f64 (+.f64 alpha beta) 2)) < -1

    1. Initial program 5.6%

      \[\frac{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1}{2} \]
    2. Step-by-step derivation
      1. +-commutative5.6%

        \[\leadsto \frac{\frac{\beta - \alpha}{\color{blue}{\left(\beta + \alpha\right)} + 2} + 1}{2} \]
    3. Simplified5.6%

      \[\leadsto \color{blue}{\frac{\frac{\beta - \alpha}{\left(\beta + \alpha\right) + 2} + 1}{2}} \]
    4. Taylor expanded in alpha around inf 100.0%

      \[\leadsto \frac{\color{blue}{\frac{2 + 2 \cdot \beta}{\alpha}}}{2} \]
    5. Taylor expanded in alpha around 0 100.0%

      \[\leadsto \color{blue}{0.5 \cdot \frac{2 + 2 \cdot \beta}{\alpha}} \]
    6. Step-by-step derivation
      1. metadata-eval100.0%

        \[\leadsto \color{blue}{\frac{1}{2}} \cdot \frac{2 + 2 \cdot \beta}{\alpha} \]
      2. +-commutative100.0%

        \[\leadsto \frac{1}{2} \cdot \frac{\color{blue}{2 \cdot \beta + 2}}{\alpha} \]
      3. fma-udef100.0%

        \[\leadsto \frac{1}{2} \cdot \frac{\color{blue}{\mathsf{fma}\left(2, \beta, 2\right)}}{\alpha} \]
      4. times-frac100.0%

        \[\leadsto \color{blue}{\frac{1 \cdot \mathsf{fma}\left(2, \beta, 2\right)}{2 \cdot \alpha}} \]
      5. *-lft-identity100.0%

        \[\leadsto \frac{\color{blue}{\mathsf{fma}\left(2, \beta, 2\right)}}{2 \cdot \alpha} \]
      6. fma-udef100.0%

        \[\leadsto \frac{\color{blue}{2 \cdot \beta + 2}}{2 \cdot \alpha} \]
      7. *-commutative100.0%

        \[\leadsto \frac{\color{blue}{\beta \cdot 2} + 2}{2 \cdot \alpha} \]
      8. distribute-lft1-in100.0%

        \[\leadsto \frac{\color{blue}{\left(\beta + 1\right) \cdot 2}}{2 \cdot \alpha} \]
      9. *-commutative100.0%

        \[\leadsto \frac{\left(\beta + 1\right) \cdot 2}{\color{blue}{\alpha \cdot 2}} \]
      10. times-frac100.0%

        \[\leadsto \color{blue}{\frac{\beta + 1}{\alpha} \cdot \frac{2}{2}} \]
      11. metadata-eval100.0%

        \[\leadsto \frac{\beta + 1}{\alpha} \cdot \color{blue}{1} \]
    7. Simplified100.0%

      \[\leadsto \color{blue}{\frac{\beta + 1}{\alpha} \cdot 1} \]

    if -1 < (/.f64 (-.f64 beta alpha) (+.f64 (+.f64 alpha beta) 2))

    1. Initial program 100.0%

      \[\frac{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1}{2} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification100.0%

    \[\leadsto \begin{array}{l} \mathbf{if}\;\frac{\beta - \alpha}{\left(\beta + \alpha\right) + 2} \leq -1:\\ \;\;\;\;\frac{\beta + 1}{\alpha}\\ \mathbf{else}:\\ \;\;\;\;\frac{\frac{\beta - \alpha}{\left(\beta + \alpha\right) + 2} + 1}{2}\\ \end{array} \]

Alternative 3: 73.7% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \frac{1 - \alpha \cdot 0.5}{2}\\ \mathbf{if}\;\alpha \leq 5 \cdot 10^{-287}:\\ \;\;\;\;t_0\\ \mathbf{elif}\;\alpha \leq 10^{-271}:\\ \;\;\;\;1\\ \mathbf{elif}\;\alpha \leq 1.95:\\ \;\;\;\;t_0\\ \mathbf{else}:\\ \;\;\;\;\frac{\beta + 1}{\alpha}\\ \end{array} \end{array} \]
(FPCore (alpha beta)
 :precision binary64
 (let* ((t_0 (/ (- 1.0 (* alpha 0.5)) 2.0)))
   (if (<= alpha 5e-287)
     t_0
     (if (<= alpha 1e-271)
       1.0
       (if (<= alpha 1.95) t_0 (/ (+ beta 1.0) alpha))))))
double code(double alpha, double beta) {
	double t_0 = (1.0 - (alpha * 0.5)) / 2.0;
	double tmp;
	if (alpha <= 5e-287) {
		tmp = t_0;
	} else if (alpha <= 1e-271) {
		tmp = 1.0;
	} else if (alpha <= 1.95) {
		tmp = t_0;
	} else {
		tmp = (beta + 1.0) / alpha;
	}
	return tmp;
}
real(8) function code(alpha, beta)
    real(8), intent (in) :: alpha
    real(8), intent (in) :: beta
    real(8) :: t_0
    real(8) :: tmp
    t_0 = (1.0d0 - (alpha * 0.5d0)) / 2.0d0
    if (alpha <= 5d-287) then
        tmp = t_0
    else if (alpha <= 1d-271) then
        tmp = 1.0d0
    else if (alpha <= 1.95d0) then
        tmp = t_0
    else
        tmp = (beta + 1.0d0) / alpha
    end if
    code = tmp
end function
public static double code(double alpha, double beta) {
	double t_0 = (1.0 - (alpha * 0.5)) / 2.0;
	double tmp;
	if (alpha <= 5e-287) {
		tmp = t_0;
	} else if (alpha <= 1e-271) {
		tmp = 1.0;
	} else if (alpha <= 1.95) {
		tmp = t_0;
	} else {
		tmp = (beta + 1.0) / alpha;
	}
	return tmp;
}
def code(alpha, beta):
	t_0 = (1.0 - (alpha * 0.5)) / 2.0
	tmp = 0
	if alpha <= 5e-287:
		tmp = t_0
	elif alpha <= 1e-271:
		tmp = 1.0
	elif alpha <= 1.95:
		tmp = t_0
	else:
		tmp = (beta + 1.0) / alpha
	return tmp
function code(alpha, beta)
	t_0 = Float64(Float64(1.0 - Float64(alpha * 0.5)) / 2.0)
	tmp = 0.0
	if (alpha <= 5e-287)
		tmp = t_0;
	elseif (alpha <= 1e-271)
		tmp = 1.0;
	elseif (alpha <= 1.95)
		tmp = t_0;
	else
		tmp = Float64(Float64(beta + 1.0) / alpha);
	end
	return tmp
end
function tmp_2 = code(alpha, beta)
	t_0 = (1.0 - (alpha * 0.5)) / 2.0;
	tmp = 0.0;
	if (alpha <= 5e-287)
		tmp = t_0;
	elseif (alpha <= 1e-271)
		tmp = 1.0;
	elseif (alpha <= 1.95)
		tmp = t_0;
	else
		tmp = (beta + 1.0) / alpha;
	end
	tmp_2 = tmp;
end
code[alpha_, beta_] := Block[{t$95$0 = N[(N[(1.0 - N[(alpha * 0.5), $MachinePrecision]), $MachinePrecision] / 2.0), $MachinePrecision]}, If[LessEqual[alpha, 5e-287], t$95$0, If[LessEqual[alpha, 1e-271], 1.0, If[LessEqual[alpha, 1.95], t$95$0, N[(N[(beta + 1.0), $MachinePrecision] / alpha), $MachinePrecision]]]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \frac{1 - \alpha \cdot 0.5}{2}\\
\mathbf{if}\;\alpha \leq 5 \cdot 10^{-287}:\\
\;\;\;\;t_0\\

\mathbf{elif}\;\alpha \leq 10^{-271}:\\
\;\;\;\;1\\

\mathbf{elif}\;\alpha \leq 1.95:\\
\;\;\;\;t_0\\

\mathbf{else}:\\
\;\;\;\;\frac{\beta + 1}{\alpha}\\


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if alpha < 5.00000000000000025e-287 or 9.99999999999999963e-272 < alpha < 1.94999999999999996

    1. Initial program 100.0%

      \[\frac{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1}{2} \]
    2. Step-by-step derivation
      1. +-commutative100.0%

        \[\leadsto \frac{\frac{\beta - \alpha}{\color{blue}{\left(\beta + \alpha\right)} + 2} + 1}{2} \]
    3. Simplified100.0%

      \[\leadsto \color{blue}{\frac{\frac{\beta - \alpha}{\left(\beta + \alpha\right) + 2} + 1}{2}} \]
    4. Taylor expanded in beta around 0 73.3%

      \[\leadsto \frac{\color{blue}{1 - \frac{\alpha}{2 + \alpha}}}{2} \]
    5. Step-by-step derivation
      1. +-commutative73.3%

        \[\leadsto \frac{1 - \frac{\alpha}{\color{blue}{\alpha + 2}}}{2} \]
    6. Simplified73.3%

      \[\leadsto \frac{\color{blue}{1 - \frac{\alpha}{\alpha + 2}}}{2} \]
    7. Taylor expanded in alpha around 0 72.3%

      \[\leadsto \frac{1 - \color{blue}{0.5 \cdot \alpha}}{2} \]
    8. Step-by-step derivation
      1. *-commutative72.3%

        \[\leadsto \frac{1 - \color{blue}{\alpha \cdot 0.5}}{2} \]
    9. Simplified72.3%

      \[\leadsto \frac{1 - \color{blue}{\alpha \cdot 0.5}}{2} \]

    if 5.00000000000000025e-287 < alpha < 9.99999999999999963e-272

    1. Initial program 100.0%

      \[\frac{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1}{2} \]
    2. Step-by-step derivation
      1. +-commutative100.0%

        \[\leadsto \frac{\frac{\beta - \alpha}{\color{blue}{\left(\beta + \alpha\right)} + 2} + 1}{2} \]
    3. Simplified100.0%

      \[\leadsto \color{blue}{\frac{\frac{\beta - \alpha}{\left(\beta + \alpha\right) + 2} + 1}{2}} \]
    4. Taylor expanded in beta around inf 88.4%

      \[\leadsto \frac{\color{blue}{2}}{2} \]

    if 1.94999999999999996 < alpha

    1. Initial program 21.9%

      \[\frac{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1}{2} \]
    2. Step-by-step derivation
      1. +-commutative21.9%

        \[\leadsto \frac{\frac{\beta - \alpha}{\color{blue}{\left(\beta + \alpha\right)} + 2} + 1}{2} \]
    3. Simplified21.9%

      \[\leadsto \color{blue}{\frac{\frac{\beta - \alpha}{\left(\beta + \alpha\right) + 2} + 1}{2}} \]
    4. Taylor expanded in alpha around inf 83.8%

      \[\leadsto \frac{\color{blue}{\frac{2 + 2 \cdot \beta}{\alpha}}}{2} \]
    5. Taylor expanded in alpha around 0 83.8%

      \[\leadsto \color{blue}{0.5 \cdot \frac{2 + 2 \cdot \beta}{\alpha}} \]
    6. Step-by-step derivation
      1. metadata-eval83.8%

        \[\leadsto \color{blue}{\frac{1}{2}} \cdot \frac{2 + 2 \cdot \beta}{\alpha} \]
      2. +-commutative83.8%

        \[\leadsto \frac{1}{2} \cdot \frac{\color{blue}{2 \cdot \beta + 2}}{\alpha} \]
      3. fma-udef83.8%

        \[\leadsto \frac{1}{2} \cdot \frac{\color{blue}{\mathsf{fma}\left(2, \beta, 2\right)}}{\alpha} \]
      4. times-frac83.8%

        \[\leadsto \color{blue}{\frac{1 \cdot \mathsf{fma}\left(2, \beta, 2\right)}{2 \cdot \alpha}} \]
      5. *-lft-identity83.8%

        \[\leadsto \frac{\color{blue}{\mathsf{fma}\left(2, \beta, 2\right)}}{2 \cdot \alpha} \]
      6. fma-udef83.8%

        \[\leadsto \frac{\color{blue}{2 \cdot \beta + 2}}{2 \cdot \alpha} \]
      7. *-commutative83.8%

        \[\leadsto \frac{\color{blue}{\beta \cdot 2} + 2}{2 \cdot \alpha} \]
      8. distribute-lft1-in83.8%

        \[\leadsto \frac{\color{blue}{\left(\beta + 1\right) \cdot 2}}{2 \cdot \alpha} \]
      9. *-commutative83.8%

        \[\leadsto \frac{\left(\beta + 1\right) \cdot 2}{\color{blue}{\alpha \cdot 2}} \]
      10. times-frac83.8%

        \[\leadsto \color{blue}{\frac{\beta + 1}{\alpha} \cdot \frac{2}{2}} \]
      11. metadata-eval83.8%

        \[\leadsto \frac{\beta + 1}{\alpha} \cdot \color{blue}{1} \]
    7. Simplified83.8%

      \[\leadsto \color{blue}{\frac{\beta + 1}{\alpha} \cdot 1} \]
  3. Recombined 3 regimes into one program.
  4. Final simplification77.2%

    \[\leadsto \begin{array}{l} \mathbf{if}\;\alpha \leq 5 \cdot 10^{-287}:\\ \;\;\;\;\frac{1 - \alpha \cdot 0.5}{2}\\ \mathbf{elif}\;\alpha \leq 10^{-271}:\\ \;\;\;\;1\\ \mathbf{elif}\;\alpha \leq 1.95:\\ \;\;\;\;\frac{1 - \alpha \cdot 0.5}{2}\\ \mathbf{else}:\\ \;\;\;\;\frac{\beta + 1}{\alpha}\\ \end{array} \]

Alternative 4: 73.0% accurate, 1.2× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;\alpha \leq 8 \cdot 10^{-287}:\\ \;\;\;\;0.5\\ \mathbf{elif}\;\alpha \leq 6.2 \cdot 10^{-272}:\\ \;\;\;\;1\\ \mathbf{elif}\;\alpha \leq 80000000000:\\ \;\;\;\;0.5\\ \mathbf{else}:\\ \;\;\;\;\frac{\beta + 1}{\alpha}\\ \end{array} \end{array} \]
(FPCore (alpha beta)
 :precision binary64
 (if (<= alpha 8e-287)
   0.5
   (if (<= alpha 6.2e-272)
     1.0
     (if (<= alpha 80000000000.0) 0.5 (/ (+ beta 1.0) alpha)))))
double code(double alpha, double beta) {
	double tmp;
	if (alpha <= 8e-287) {
		tmp = 0.5;
	} else if (alpha <= 6.2e-272) {
		tmp = 1.0;
	} else if (alpha <= 80000000000.0) {
		tmp = 0.5;
	} else {
		tmp = (beta + 1.0) / alpha;
	}
	return tmp;
}
real(8) function code(alpha, beta)
    real(8), intent (in) :: alpha
    real(8), intent (in) :: beta
    real(8) :: tmp
    if (alpha <= 8d-287) then
        tmp = 0.5d0
    else if (alpha <= 6.2d-272) then
        tmp = 1.0d0
    else if (alpha <= 80000000000.0d0) then
        tmp = 0.5d0
    else
        tmp = (beta + 1.0d0) / alpha
    end if
    code = tmp
end function
public static double code(double alpha, double beta) {
	double tmp;
	if (alpha <= 8e-287) {
		tmp = 0.5;
	} else if (alpha <= 6.2e-272) {
		tmp = 1.0;
	} else if (alpha <= 80000000000.0) {
		tmp = 0.5;
	} else {
		tmp = (beta + 1.0) / alpha;
	}
	return tmp;
}
def code(alpha, beta):
	tmp = 0
	if alpha <= 8e-287:
		tmp = 0.5
	elif alpha <= 6.2e-272:
		tmp = 1.0
	elif alpha <= 80000000000.0:
		tmp = 0.5
	else:
		tmp = (beta + 1.0) / alpha
	return tmp
function code(alpha, beta)
	tmp = 0.0
	if (alpha <= 8e-287)
		tmp = 0.5;
	elseif (alpha <= 6.2e-272)
		tmp = 1.0;
	elseif (alpha <= 80000000000.0)
		tmp = 0.5;
	else
		tmp = Float64(Float64(beta + 1.0) / alpha);
	end
	return tmp
end
function tmp_2 = code(alpha, beta)
	tmp = 0.0;
	if (alpha <= 8e-287)
		tmp = 0.5;
	elseif (alpha <= 6.2e-272)
		tmp = 1.0;
	elseif (alpha <= 80000000000.0)
		tmp = 0.5;
	else
		tmp = (beta + 1.0) / alpha;
	end
	tmp_2 = tmp;
end
code[alpha_, beta_] := If[LessEqual[alpha, 8e-287], 0.5, If[LessEqual[alpha, 6.2e-272], 1.0, If[LessEqual[alpha, 80000000000.0], 0.5, N[(N[(beta + 1.0), $MachinePrecision] / alpha), $MachinePrecision]]]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;\alpha \leq 8 \cdot 10^{-287}:\\
\;\;\;\;0.5\\

\mathbf{elif}\;\alpha \leq 6.2 \cdot 10^{-272}:\\
\;\;\;\;1\\

\mathbf{elif}\;\alpha \leq 80000000000:\\
\;\;\;\;0.5\\

\mathbf{else}:\\
\;\;\;\;\frac{\beta + 1}{\alpha}\\


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if alpha < 8.00000000000000017e-287 or 6.20000000000000059e-272 < alpha < 8e10

    1. Initial program 100.0%

      \[\frac{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1}{2} \]
    2. Step-by-step derivation
      1. +-commutative100.0%

        \[\leadsto \frac{\frac{\beta - \alpha}{\color{blue}{\left(\beta + \alpha\right)} + 2} + 1}{2} \]
    3. Simplified100.0%

      \[\leadsto \color{blue}{\frac{\frac{\beta - \alpha}{\left(\beta + \alpha\right) + 2} + 1}{2}} \]
    4. Step-by-step derivation
      1. add-exp-log100.0%

        \[\leadsto \frac{\color{blue}{e^{\log \left(\frac{\beta - \alpha}{\left(\beta + \alpha\right) + 2} + 1\right)}}}{2} \]
      2. +-commutative100.0%

        \[\leadsto \frac{e^{\log \color{blue}{\left(1 + \frac{\beta - \alpha}{\left(\beta + \alpha\right) + 2}\right)}}}{2} \]
      3. log1p-udef100.0%

        \[\leadsto \frac{e^{\color{blue}{\mathsf{log1p}\left(\frac{\beta - \alpha}{\left(\beta + \alpha\right) + 2}\right)}}}{2} \]
      4. associate-+l+100.0%

        \[\leadsto \frac{e^{\mathsf{log1p}\left(\frac{\beta - \alpha}{\color{blue}{\beta + \left(\alpha + 2\right)}}\right)}}{2} \]
    5. Applied egg-rr100.0%

      \[\leadsto \frac{\color{blue}{e^{\mathsf{log1p}\left(\frac{\beta - \alpha}{\beta + \left(\alpha + 2\right)}\right)}}}{2} \]
    6. Step-by-step derivation
      1. +-commutative100.0%

        \[\leadsto \frac{e^{\mathsf{log1p}\left(\frac{\beta - \alpha}{\color{blue}{\left(\alpha + 2\right) + \beta}}\right)}}{2} \]
    7. Simplified100.0%

      \[\leadsto \frac{\color{blue}{e^{\mathsf{log1p}\left(\frac{\beta - \alpha}{\left(\alpha + 2\right) + \beta}\right)}}}{2} \]
    8. Taylor expanded in alpha around 0 97.9%

      \[\leadsto \frac{e^{\mathsf{log1p}\left(\color{blue}{\frac{\beta}{\beta + 2}}\right)}}{2} \]
    9. Taylor expanded in beta around 0 70.9%

      \[\leadsto \frac{\color{blue}{1}}{2} \]

    if 8.00000000000000017e-287 < alpha < 6.20000000000000059e-272

    1. Initial program 100.0%

      \[\frac{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1}{2} \]
    2. Step-by-step derivation
      1. +-commutative100.0%

        \[\leadsto \frac{\frac{\beta - \alpha}{\color{blue}{\left(\beta + \alpha\right)} + 2} + 1}{2} \]
    3. Simplified100.0%

      \[\leadsto \color{blue}{\frac{\frac{\beta - \alpha}{\left(\beta + \alpha\right) + 2} + 1}{2}} \]
    4. Taylor expanded in beta around inf 88.4%

      \[\leadsto \frac{\color{blue}{2}}{2} \]

    if 8e10 < alpha

    1. Initial program 21.1%

      \[\frac{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1}{2} \]
    2. Step-by-step derivation
      1. +-commutative21.1%

        \[\leadsto \frac{\frac{\beta - \alpha}{\color{blue}{\left(\beta + \alpha\right)} + 2} + 1}{2} \]
    3. Simplified21.1%

      \[\leadsto \color{blue}{\frac{\frac{\beta - \alpha}{\left(\beta + \alpha\right) + 2} + 1}{2}} \]
    4. Taylor expanded in alpha around inf 84.6%

      \[\leadsto \frac{\color{blue}{\frac{2 + 2 \cdot \beta}{\alpha}}}{2} \]
    5. Taylor expanded in alpha around 0 84.6%

      \[\leadsto \color{blue}{0.5 \cdot \frac{2 + 2 \cdot \beta}{\alpha}} \]
    6. Step-by-step derivation
      1. metadata-eval84.6%

        \[\leadsto \color{blue}{\frac{1}{2}} \cdot \frac{2 + 2 \cdot \beta}{\alpha} \]
      2. +-commutative84.6%

        \[\leadsto \frac{1}{2} \cdot \frac{\color{blue}{2 \cdot \beta + 2}}{\alpha} \]
      3. fma-udef84.6%

        \[\leadsto \frac{1}{2} \cdot \frac{\color{blue}{\mathsf{fma}\left(2, \beta, 2\right)}}{\alpha} \]
      4. times-frac84.6%

        \[\leadsto \color{blue}{\frac{1 \cdot \mathsf{fma}\left(2, \beta, 2\right)}{2 \cdot \alpha}} \]
      5. *-lft-identity84.6%

        \[\leadsto \frac{\color{blue}{\mathsf{fma}\left(2, \beta, 2\right)}}{2 \cdot \alpha} \]
      6. fma-udef84.6%

        \[\leadsto \frac{\color{blue}{2 \cdot \beta + 2}}{2 \cdot \alpha} \]
      7. *-commutative84.6%

        \[\leadsto \frac{\color{blue}{\beta \cdot 2} + 2}{2 \cdot \alpha} \]
      8. distribute-lft1-in84.6%

        \[\leadsto \frac{\color{blue}{\left(\beta + 1\right) \cdot 2}}{2 \cdot \alpha} \]
      9. *-commutative84.6%

        \[\leadsto \frac{\left(\beta + 1\right) \cdot 2}{\color{blue}{\alpha \cdot 2}} \]
      10. times-frac84.6%

        \[\leadsto \color{blue}{\frac{\beta + 1}{\alpha} \cdot \frac{2}{2}} \]
      11. metadata-eval84.6%

        \[\leadsto \frac{\beta + 1}{\alpha} \cdot \color{blue}{1} \]
    7. Simplified84.6%

      \[\leadsto \color{blue}{\frac{\beta + 1}{\alpha} \cdot 1} \]
  3. Recombined 3 regimes into one program.
  4. Final simplification76.6%

    \[\leadsto \begin{array}{l} \mathbf{if}\;\alpha \leq 8 \cdot 10^{-287}:\\ \;\;\;\;0.5\\ \mathbf{elif}\;\alpha \leq 6.2 \cdot 10^{-272}:\\ \;\;\;\;1\\ \mathbf{elif}\;\alpha \leq 80000000000:\\ \;\;\;\;0.5\\ \mathbf{else}:\\ \;\;\;\;\frac{\beta + 1}{\alpha}\\ \end{array} \]

Alternative 5: 93.2% accurate, 1.2× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;\alpha \leq 680000000000:\\ \;\;\;\;\frac{1 + \frac{\beta}{\beta + 2}}{2}\\ \mathbf{else}:\\ \;\;\;\;\frac{\beta + 1}{\alpha}\\ \end{array} \end{array} \]
(FPCore (alpha beta)
 :precision binary64
 (if (<= alpha 680000000000.0)
   (/ (+ 1.0 (/ beta (+ beta 2.0))) 2.0)
   (/ (+ beta 1.0) alpha)))
double code(double alpha, double beta) {
	double tmp;
	if (alpha <= 680000000000.0) {
		tmp = (1.0 + (beta / (beta + 2.0))) / 2.0;
	} else {
		tmp = (beta + 1.0) / alpha;
	}
	return tmp;
}
real(8) function code(alpha, beta)
    real(8), intent (in) :: alpha
    real(8), intent (in) :: beta
    real(8) :: tmp
    if (alpha <= 680000000000.0d0) then
        tmp = (1.0d0 + (beta / (beta + 2.0d0))) / 2.0d0
    else
        tmp = (beta + 1.0d0) / alpha
    end if
    code = tmp
end function
public static double code(double alpha, double beta) {
	double tmp;
	if (alpha <= 680000000000.0) {
		tmp = (1.0 + (beta / (beta + 2.0))) / 2.0;
	} else {
		tmp = (beta + 1.0) / alpha;
	}
	return tmp;
}
def code(alpha, beta):
	tmp = 0
	if alpha <= 680000000000.0:
		tmp = (1.0 + (beta / (beta + 2.0))) / 2.0
	else:
		tmp = (beta + 1.0) / alpha
	return tmp
function code(alpha, beta)
	tmp = 0.0
	if (alpha <= 680000000000.0)
		tmp = Float64(Float64(1.0 + Float64(beta / Float64(beta + 2.0))) / 2.0);
	else
		tmp = Float64(Float64(beta + 1.0) / alpha);
	end
	return tmp
end
function tmp_2 = code(alpha, beta)
	tmp = 0.0;
	if (alpha <= 680000000000.0)
		tmp = (1.0 + (beta / (beta + 2.0))) / 2.0;
	else
		tmp = (beta + 1.0) / alpha;
	end
	tmp_2 = tmp;
end
code[alpha_, beta_] := If[LessEqual[alpha, 680000000000.0], N[(N[(1.0 + N[(beta / N[(beta + 2.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / 2.0), $MachinePrecision], N[(N[(beta + 1.0), $MachinePrecision] / alpha), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;\alpha \leq 680000000000:\\
\;\;\;\;\frac{1 + \frac{\beta}{\beta + 2}}{2}\\

\mathbf{else}:\\
\;\;\;\;\frac{\beta + 1}{\alpha}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if alpha < 6.8e11

    1. Initial program 100.0%

      \[\frac{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1}{2} \]
    2. Step-by-step derivation
      1. +-commutative100.0%

        \[\leadsto \frac{\frac{\beta - \alpha}{\color{blue}{\left(\beta + \alpha\right)} + 2} + 1}{2} \]
    3. Simplified100.0%

      \[\leadsto \color{blue}{\frac{\frac{\beta - \alpha}{\left(\beta + \alpha\right) + 2} + 1}{2}} \]
    4. Taylor expanded in alpha around 0 98.0%

      \[\leadsto \frac{\color{blue}{\frac{\beta}{\beta + 2}} + 1}{2} \]

    if 6.8e11 < alpha

    1. Initial program 21.1%

      \[\frac{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1}{2} \]
    2. Step-by-step derivation
      1. +-commutative21.1%

        \[\leadsto \frac{\frac{\beta - \alpha}{\color{blue}{\left(\beta + \alpha\right)} + 2} + 1}{2} \]
    3. Simplified21.1%

      \[\leadsto \color{blue}{\frac{\frac{\beta - \alpha}{\left(\beta + \alpha\right) + 2} + 1}{2}} \]
    4. Taylor expanded in alpha around inf 84.6%

      \[\leadsto \frac{\color{blue}{\frac{2 + 2 \cdot \beta}{\alpha}}}{2} \]
    5. Taylor expanded in alpha around 0 84.6%

      \[\leadsto \color{blue}{0.5 \cdot \frac{2 + 2 \cdot \beta}{\alpha}} \]
    6. Step-by-step derivation
      1. metadata-eval84.6%

        \[\leadsto \color{blue}{\frac{1}{2}} \cdot \frac{2 + 2 \cdot \beta}{\alpha} \]
      2. +-commutative84.6%

        \[\leadsto \frac{1}{2} \cdot \frac{\color{blue}{2 \cdot \beta + 2}}{\alpha} \]
      3. fma-udef84.6%

        \[\leadsto \frac{1}{2} \cdot \frac{\color{blue}{\mathsf{fma}\left(2, \beta, 2\right)}}{\alpha} \]
      4. times-frac84.6%

        \[\leadsto \color{blue}{\frac{1 \cdot \mathsf{fma}\left(2, \beta, 2\right)}{2 \cdot \alpha}} \]
      5. *-lft-identity84.6%

        \[\leadsto \frac{\color{blue}{\mathsf{fma}\left(2, \beta, 2\right)}}{2 \cdot \alpha} \]
      6. fma-udef84.6%

        \[\leadsto \frac{\color{blue}{2 \cdot \beta + 2}}{2 \cdot \alpha} \]
      7. *-commutative84.6%

        \[\leadsto \frac{\color{blue}{\beta \cdot 2} + 2}{2 \cdot \alpha} \]
      8. distribute-lft1-in84.6%

        \[\leadsto \frac{\color{blue}{\left(\beta + 1\right) \cdot 2}}{2 \cdot \alpha} \]
      9. *-commutative84.6%

        \[\leadsto \frac{\left(\beta + 1\right) \cdot 2}{\color{blue}{\alpha \cdot 2}} \]
      10. times-frac84.6%

        \[\leadsto \color{blue}{\frac{\beta + 1}{\alpha} \cdot \frac{2}{2}} \]
      11. metadata-eval84.6%

        \[\leadsto \frac{\beta + 1}{\alpha} \cdot \color{blue}{1} \]
    7. Simplified84.6%

      \[\leadsto \color{blue}{\frac{\beta + 1}{\alpha} \cdot 1} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification92.9%

    \[\leadsto \begin{array}{l} \mathbf{if}\;\alpha \leq 680000000000:\\ \;\;\;\;\frac{1 + \frac{\beta}{\beta + 2}}{2}\\ \mathbf{else}:\\ \;\;\;\;\frac{\beta + 1}{\alpha}\\ \end{array} \]

Alternative 6: 67.7% accurate, 1.4× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;\alpha \leq 7.2 \cdot 10^{-287}:\\ \;\;\;\;0.5\\ \mathbf{elif}\;\alpha \leq 6.2 \cdot 10^{-272}:\\ \;\;\;\;1\\ \mathbf{elif}\;\alpha \leq 80000000000:\\ \;\;\;\;0.5\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{\alpha}\\ \end{array} \end{array} \]
(FPCore (alpha beta)
 :precision binary64
 (if (<= alpha 7.2e-287)
   0.5
   (if (<= alpha 6.2e-272)
     1.0
     (if (<= alpha 80000000000.0) 0.5 (/ 1.0 alpha)))))
double code(double alpha, double beta) {
	double tmp;
	if (alpha <= 7.2e-287) {
		tmp = 0.5;
	} else if (alpha <= 6.2e-272) {
		tmp = 1.0;
	} else if (alpha <= 80000000000.0) {
		tmp = 0.5;
	} else {
		tmp = 1.0 / alpha;
	}
	return tmp;
}
real(8) function code(alpha, beta)
    real(8), intent (in) :: alpha
    real(8), intent (in) :: beta
    real(8) :: tmp
    if (alpha <= 7.2d-287) then
        tmp = 0.5d0
    else if (alpha <= 6.2d-272) then
        tmp = 1.0d0
    else if (alpha <= 80000000000.0d0) then
        tmp = 0.5d0
    else
        tmp = 1.0d0 / alpha
    end if
    code = tmp
end function
public static double code(double alpha, double beta) {
	double tmp;
	if (alpha <= 7.2e-287) {
		tmp = 0.5;
	} else if (alpha <= 6.2e-272) {
		tmp = 1.0;
	} else if (alpha <= 80000000000.0) {
		tmp = 0.5;
	} else {
		tmp = 1.0 / alpha;
	}
	return tmp;
}
def code(alpha, beta):
	tmp = 0
	if alpha <= 7.2e-287:
		tmp = 0.5
	elif alpha <= 6.2e-272:
		tmp = 1.0
	elif alpha <= 80000000000.0:
		tmp = 0.5
	else:
		tmp = 1.0 / alpha
	return tmp
function code(alpha, beta)
	tmp = 0.0
	if (alpha <= 7.2e-287)
		tmp = 0.5;
	elseif (alpha <= 6.2e-272)
		tmp = 1.0;
	elseif (alpha <= 80000000000.0)
		tmp = 0.5;
	else
		tmp = Float64(1.0 / alpha);
	end
	return tmp
end
function tmp_2 = code(alpha, beta)
	tmp = 0.0;
	if (alpha <= 7.2e-287)
		tmp = 0.5;
	elseif (alpha <= 6.2e-272)
		tmp = 1.0;
	elseif (alpha <= 80000000000.0)
		tmp = 0.5;
	else
		tmp = 1.0 / alpha;
	end
	tmp_2 = tmp;
end
code[alpha_, beta_] := If[LessEqual[alpha, 7.2e-287], 0.5, If[LessEqual[alpha, 6.2e-272], 1.0, If[LessEqual[alpha, 80000000000.0], 0.5, N[(1.0 / alpha), $MachinePrecision]]]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;\alpha \leq 7.2 \cdot 10^{-287}:\\
\;\;\;\;0.5\\

\mathbf{elif}\;\alpha \leq 6.2 \cdot 10^{-272}:\\
\;\;\;\;1\\

\mathbf{elif}\;\alpha \leq 80000000000:\\
\;\;\;\;0.5\\

\mathbf{else}:\\
\;\;\;\;\frac{1}{\alpha}\\


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if alpha < 7.2000000000000003e-287 or 6.20000000000000059e-272 < alpha < 8e10

    1. Initial program 100.0%

      \[\frac{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1}{2} \]
    2. Step-by-step derivation
      1. +-commutative100.0%

        \[\leadsto \frac{\frac{\beta - \alpha}{\color{blue}{\left(\beta + \alpha\right)} + 2} + 1}{2} \]
    3. Simplified100.0%

      \[\leadsto \color{blue}{\frac{\frac{\beta - \alpha}{\left(\beta + \alpha\right) + 2} + 1}{2}} \]
    4. Step-by-step derivation
      1. add-exp-log100.0%

        \[\leadsto \frac{\color{blue}{e^{\log \left(\frac{\beta - \alpha}{\left(\beta + \alpha\right) + 2} + 1\right)}}}{2} \]
      2. +-commutative100.0%

        \[\leadsto \frac{e^{\log \color{blue}{\left(1 + \frac{\beta - \alpha}{\left(\beta + \alpha\right) + 2}\right)}}}{2} \]
      3. log1p-udef100.0%

        \[\leadsto \frac{e^{\color{blue}{\mathsf{log1p}\left(\frac{\beta - \alpha}{\left(\beta + \alpha\right) + 2}\right)}}}{2} \]
      4. associate-+l+100.0%

        \[\leadsto \frac{e^{\mathsf{log1p}\left(\frac{\beta - \alpha}{\color{blue}{\beta + \left(\alpha + 2\right)}}\right)}}{2} \]
    5. Applied egg-rr100.0%

      \[\leadsto \frac{\color{blue}{e^{\mathsf{log1p}\left(\frac{\beta - \alpha}{\beta + \left(\alpha + 2\right)}\right)}}}{2} \]
    6. Step-by-step derivation
      1. +-commutative100.0%

        \[\leadsto \frac{e^{\mathsf{log1p}\left(\frac{\beta - \alpha}{\color{blue}{\left(\alpha + 2\right) + \beta}}\right)}}{2} \]
    7. Simplified100.0%

      \[\leadsto \frac{\color{blue}{e^{\mathsf{log1p}\left(\frac{\beta - \alpha}{\left(\alpha + 2\right) + \beta}\right)}}}{2} \]
    8. Taylor expanded in alpha around 0 97.9%

      \[\leadsto \frac{e^{\mathsf{log1p}\left(\color{blue}{\frac{\beta}{\beta + 2}}\right)}}{2} \]
    9. Taylor expanded in beta around 0 70.9%

      \[\leadsto \frac{\color{blue}{1}}{2} \]

    if 7.2000000000000003e-287 < alpha < 6.20000000000000059e-272

    1. Initial program 100.0%

      \[\frac{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1}{2} \]
    2. Step-by-step derivation
      1. +-commutative100.0%

        \[\leadsto \frac{\frac{\beta - \alpha}{\color{blue}{\left(\beta + \alpha\right)} + 2} + 1}{2} \]
    3. Simplified100.0%

      \[\leadsto \color{blue}{\frac{\frac{\beta - \alpha}{\left(\beta + \alpha\right) + 2} + 1}{2}} \]
    4. Taylor expanded in beta around inf 88.4%

      \[\leadsto \frac{\color{blue}{2}}{2} \]

    if 8e10 < alpha

    1. Initial program 21.1%

      \[\frac{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1}{2} \]
    2. Step-by-step derivation
      1. +-commutative21.1%

        \[\leadsto \frac{\frac{\beta - \alpha}{\color{blue}{\left(\beta + \alpha\right)} + 2} + 1}{2} \]
    3. Simplified21.1%

      \[\leadsto \color{blue}{\frac{\frac{\beta - \alpha}{\left(\beta + \alpha\right) + 2} + 1}{2}} \]
    4. Taylor expanded in alpha around inf 84.6%

      \[\leadsto \frac{\color{blue}{\frac{2 + 2 \cdot \beta}{\alpha}}}{2} \]
    5. Taylor expanded in beta around 0 76.4%

      \[\leadsto \color{blue}{\frac{1}{\alpha}} \]
  3. Recombined 3 regimes into one program.
  4. Final simplification73.4%

    \[\leadsto \begin{array}{l} \mathbf{if}\;\alpha \leq 7.2 \cdot 10^{-287}:\\ \;\;\;\;0.5\\ \mathbf{elif}\;\alpha \leq 6.2 \cdot 10^{-272}:\\ \;\;\;\;1\\ \mathbf{elif}\;\alpha \leq 80000000000:\\ \;\;\;\;0.5\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{\alpha}\\ \end{array} \]

Alternative 7: 68.3% accurate, 2.6× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;\alpha \leq 80000000000:\\ \;\;\;\;0.5\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{\alpha}\\ \end{array} \end{array} \]
(FPCore (alpha beta)
 :precision binary64
 (if (<= alpha 80000000000.0) 0.5 (/ 1.0 alpha)))
double code(double alpha, double beta) {
	double tmp;
	if (alpha <= 80000000000.0) {
		tmp = 0.5;
	} else {
		tmp = 1.0 / alpha;
	}
	return tmp;
}
real(8) function code(alpha, beta)
    real(8), intent (in) :: alpha
    real(8), intent (in) :: beta
    real(8) :: tmp
    if (alpha <= 80000000000.0d0) then
        tmp = 0.5d0
    else
        tmp = 1.0d0 / alpha
    end if
    code = tmp
end function
public static double code(double alpha, double beta) {
	double tmp;
	if (alpha <= 80000000000.0) {
		tmp = 0.5;
	} else {
		tmp = 1.0 / alpha;
	}
	return tmp;
}
def code(alpha, beta):
	tmp = 0
	if alpha <= 80000000000.0:
		tmp = 0.5
	else:
		tmp = 1.0 / alpha
	return tmp
function code(alpha, beta)
	tmp = 0.0
	if (alpha <= 80000000000.0)
		tmp = 0.5;
	else
		tmp = Float64(1.0 / alpha);
	end
	return tmp
end
function tmp_2 = code(alpha, beta)
	tmp = 0.0;
	if (alpha <= 80000000000.0)
		tmp = 0.5;
	else
		tmp = 1.0 / alpha;
	end
	tmp_2 = tmp;
end
code[alpha_, beta_] := If[LessEqual[alpha, 80000000000.0], 0.5, N[(1.0 / alpha), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;\alpha \leq 80000000000:\\
\;\;\;\;0.5\\

\mathbf{else}:\\
\;\;\;\;\frac{1}{\alpha}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if alpha < 8e10

    1. Initial program 100.0%

      \[\frac{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1}{2} \]
    2. Step-by-step derivation
      1. +-commutative100.0%

        \[\leadsto \frac{\frac{\beta - \alpha}{\color{blue}{\left(\beta + \alpha\right)} + 2} + 1}{2} \]
    3. Simplified100.0%

      \[\leadsto \color{blue}{\frac{\frac{\beta - \alpha}{\left(\beta + \alpha\right) + 2} + 1}{2}} \]
    4. Step-by-step derivation
      1. add-exp-log100.0%

        \[\leadsto \frac{\color{blue}{e^{\log \left(\frac{\beta - \alpha}{\left(\beta + \alpha\right) + 2} + 1\right)}}}{2} \]
      2. +-commutative100.0%

        \[\leadsto \frac{e^{\log \color{blue}{\left(1 + \frac{\beta - \alpha}{\left(\beta + \alpha\right) + 2}\right)}}}{2} \]
      3. log1p-udef100.0%

        \[\leadsto \frac{e^{\color{blue}{\mathsf{log1p}\left(\frac{\beta - \alpha}{\left(\beta + \alpha\right) + 2}\right)}}}{2} \]
      4. associate-+l+100.0%

        \[\leadsto \frac{e^{\mathsf{log1p}\left(\frac{\beta - \alpha}{\color{blue}{\beta + \left(\alpha + 2\right)}}\right)}}{2} \]
    5. Applied egg-rr100.0%

      \[\leadsto \frac{\color{blue}{e^{\mathsf{log1p}\left(\frac{\beta - \alpha}{\beta + \left(\alpha + 2\right)}\right)}}}{2} \]
    6. Step-by-step derivation
      1. +-commutative100.0%

        \[\leadsto \frac{e^{\mathsf{log1p}\left(\frac{\beta - \alpha}{\color{blue}{\left(\alpha + 2\right) + \beta}}\right)}}{2} \]
    7. Simplified100.0%

      \[\leadsto \frac{\color{blue}{e^{\mathsf{log1p}\left(\frac{\beta - \alpha}{\left(\alpha + 2\right) + \beta}\right)}}}{2} \]
    8. Taylor expanded in alpha around 0 98.0%

      \[\leadsto \frac{e^{\mathsf{log1p}\left(\color{blue}{\frac{\beta}{\beta + 2}}\right)}}{2} \]
    9. Taylor expanded in beta around 0 69.1%

      \[\leadsto \frac{\color{blue}{1}}{2} \]

    if 8e10 < alpha

    1. Initial program 21.1%

      \[\frac{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1}{2} \]
    2. Step-by-step derivation
      1. +-commutative21.1%

        \[\leadsto \frac{\frac{\beta - \alpha}{\color{blue}{\left(\beta + \alpha\right)} + 2} + 1}{2} \]
    3. Simplified21.1%

      \[\leadsto \color{blue}{\frac{\frac{\beta - \alpha}{\left(\beta + \alpha\right) + 2} + 1}{2}} \]
    4. Taylor expanded in alpha around inf 84.6%

      \[\leadsto \frac{\color{blue}{\frac{2 + 2 \cdot \beta}{\alpha}}}{2} \]
    5. Taylor expanded in beta around 0 76.4%

      \[\leadsto \color{blue}{\frac{1}{\alpha}} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification71.9%

    \[\leadsto \begin{array}{l} \mathbf{if}\;\alpha \leq 80000000000:\\ \;\;\;\;0.5\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{\alpha}\\ \end{array} \]

Alternative 8: 49.8% accurate, 13.0× speedup?

\[\begin{array}{l} \\ 0.5 \end{array} \]
(FPCore (alpha beta) :precision binary64 0.5)
double code(double alpha, double beta) {
	return 0.5;
}
real(8) function code(alpha, beta)
    real(8), intent (in) :: alpha
    real(8), intent (in) :: beta
    code = 0.5d0
end function
public static double code(double alpha, double beta) {
	return 0.5;
}
def code(alpha, beta):
	return 0.5
function code(alpha, beta)
	return 0.5
end
function tmp = code(alpha, beta)
	tmp = 0.5;
end
code[alpha_, beta_] := 0.5
\begin{array}{l}

\\
0.5
\end{array}
Derivation
  1. Initial program 70.1%

    \[\frac{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1}{2} \]
  2. Step-by-step derivation
    1. +-commutative70.1%

      \[\leadsto \frac{\frac{\beta - \alpha}{\color{blue}{\left(\beta + \alpha\right)} + 2} + 1}{2} \]
  3. Simplified70.1%

    \[\leadsto \color{blue}{\frac{\frac{\beta - \alpha}{\left(\beta + \alpha\right) + 2} + 1}{2}} \]
  4. Step-by-step derivation
    1. add-exp-log70.1%

      \[\leadsto \frac{\color{blue}{e^{\log \left(\frac{\beta - \alpha}{\left(\beta + \alpha\right) + 2} + 1\right)}}}{2} \]
    2. +-commutative70.1%

      \[\leadsto \frac{e^{\log \color{blue}{\left(1 + \frac{\beta - \alpha}{\left(\beta + \alpha\right) + 2}\right)}}}{2} \]
    3. log1p-udef70.1%

      \[\leadsto \frac{e^{\color{blue}{\mathsf{log1p}\left(\frac{\beta - \alpha}{\left(\beta + \alpha\right) + 2}\right)}}}{2} \]
    4. associate-+l+70.1%

      \[\leadsto \frac{e^{\mathsf{log1p}\left(\frac{\beta - \alpha}{\color{blue}{\beta + \left(\alpha + 2\right)}}\right)}}{2} \]
  5. Applied egg-rr70.1%

    \[\leadsto \frac{\color{blue}{e^{\mathsf{log1p}\left(\frac{\beta - \alpha}{\beta + \left(\alpha + 2\right)}\right)}}}{2} \]
  6. Step-by-step derivation
    1. +-commutative70.1%

      \[\leadsto \frac{e^{\mathsf{log1p}\left(\frac{\beta - \alpha}{\color{blue}{\left(\alpha + 2\right) + \beta}}\right)}}{2} \]
  7. Simplified70.1%

    \[\leadsto \frac{\color{blue}{e^{\mathsf{log1p}\left(\frac{\beta - \alpha}{\left(\alpha + 2\right) + \beta}\right)}}}{2} \]
  8. Taylor expanded in alpha around 0 68.6%

    \[\leadsto \frac{e^{\mathsf{log1p}\left(\color{blue}{\frac{\beta}{\beta + 2}}\right)}}{2} \]
  9. Taylor expanded in beta around 0 45.7%

    \[\leadsto \frac{\color{blue}{1}}{2} \]
  10. Final simplification45.7%

    \[\leadsto 0.5 \]

Reproduce

?
herbie shell --seed 2023178 
(FPCore (alpha beta)
  :name "Octave 3.8, jcobi/1"
  :precision binary64
  :pre (and (> alpha -1.0) (> beta -1.0))
  (/ (+ (/ (- beta alpha) (+ (+ alpha beta) 2.0)) 1.0) 2.0))