Octave 3.8, jcobi/1

Percentage Accurate: 74.0% → 99.7%
Time: 6.6s
Alternatives: 6
Speedup: 0.9×

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 6 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: 74.0% 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: 99.7% accurate, 0.5× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \frac{\beta - \alpha}{\left(\beta + \alpha\right) + 2}\\ \mathbf{if}\;t\_0 \leq -0.99999998:\\ \;\;\;\;\frac{\beta + 1}{\alpha}\\ \mathbf{else}:\\ \;\;\;\;\frac{t\_0 + 1}{2}\\ \end{array} \end{array} \]
(FPCore (alpha beta)
 :precision binary64
 (let* ((t_0 (/ (- beta alpha) (+ (+ beta alpha) 2.0))))
   (if (<= t_0 -0.99999998) (/ (+ 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 <= -0.99999998) {
		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 <= (-0.99999998d0)) 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 <= -0.99999998) {
		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 <= -0.99999998:
		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 <= -0.99999998)
		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 <= -0.99999998)
		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, -0.99999998], 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 -0.99999998:\\
\;\;\;\;\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)) < -0.999999980000000011

    1. Initial program 5.8%

      \[\frac{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1}{2} \]
    2. Step-by-step derivation
      1. +-commutative5.8%

        \[\leadsto \frac{\frac{\beta - \alpha}{\color{blue}{\left(\beta + \alpha\right)} + 2} + 1}{2} \]
    3. Simplified5.8%

      \[\leadsto \color{blue}{\frac{\frac{\beta - \alpha}{\left(\beta + \alpha\right) + 2} + 1}{2}} \]
    4. Add Preprocessing
    5. Taylor expanded in alpha around inf 99.7%

      \[\leadsto \color{blue}{0.5 \cdot \frac{2 + 2 \cdot \beta}{\alpha}} \]
    6. Step-by-step derivation
      1. associate-*r/99.7%

        \[\leadsto \color{blue}{\frac{0.5 \cdot \left(2 + 2 \cdot \beta\right)}{\alpha}} \]
      2. distribute-lft-in99.7%

        \[\leadsto \frac{\color{blue}{0.5 \cdot 2 + 0.5 \cdot \left(2 \cdot \beta\right)}}{\alpha} \]
      3. metadata-eval99.7%

        \[\leadsto \frac{\color{blue}{1} + 0.5 \cdot \left(2 \cdot \beta\right)}{\alpha} \]
      4. associate-*r*99.7%

        \[\leadsto \frac{1 + \color{blue}{\left(0.5 \cdot 2\right) \cdot \beta}}{\alpha} \]
      5. metadata-eval99.7%

        \[\leadsto \frac{1 + \color{blue}{1} \cdot \beta}{\alpha} \]
    7. Simplified99.7%

      \[\leadsto \color{blue}{\frac{1 + 1 \cdot \beta}{\alpha}} \]
    8. Taylor expanded in beta around 0 99.7%

      \[\leadsto \color{blue}{\frac{1}{\alpha} + \frac{\beta}{\alpha}} \]
    9. Step-by-step derivation
      1. +-commutative99.7%

        \[\leadsto \color{blue}{\frac{\beta}{\alpha} + \frac{1}{\alpha}} \]
      2. *-lft-identity99.7%

        \[\leadsto \frac{\color{blue}{1 \cdot \beta}}{\alpha} + \frac{1}{\alpha} \]
      3. associate-*l/99.6%

        \[\leadsto \color{blue}{\frac{1}{\alpha} \cdot \beta} + \frac{1}{\alpha} \]
      4. *-rgt-identity99.6%

        \[\leadsto \frac{1}{\alpha} \cdot \beta + \color{blue}{\frac{1}{\alpha} \cdot 1} \]
      5. distribute-lft-in99.6%

        \[\leadsto \color{blue}{\frac{1}{\alpha} \cdot \left(\beta + 1\right)} \]
      6. associate-*l/99.7%

        \[\leadsto \color{blue}{\frac{1 \cdot \left(\beta + 1\right)}{\alpha}} \]
      7. *-lft-identity99.7%

        \[\leadsto \frac{\color{blue}{\beta + 1}}{\alpha} \]
    10. Simplified99.7%

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

    if -0.999999980000000011 < (/.f64 (-.f64 beta alpha) (+.f64 (+.f64 alpha beta) 2))

    1. Initial program 99.8%

      \[\frac{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1}{2} \]
    2. Add Preprocessing
  3. Recombined 2 regimes into one program.
  4. Final simplification99.8%

    \[\leadsto \begin{array}{l} \mathbf{if}\;\frac{\beta - \alpha}{\left(\beta + \alpha\right) + 2} \leq -0.99999998:\\ \;\;\;\;\frac{\beta + 1}{\alpha}\\ \mathbf{else}:\\ \;\;\;\;\frac{\frac{\beta - \alpha}{\left(\beta + \alpha\right) + 2} + 1}{2}\\ \end{array} \]
  5. Add Preprocessing

Alternative 2: 73.8% accurate, 0.6× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := 0.5 + \alpha \cdot -0.25\\ \mathbf{if}\;\alpha \leq -1.15 \cdot 10^{-111}:\\ \;\;\;\;t\_0\\ \mathbf{elif}\;\alpha \leq -5.4 \cdot 10^{-151}:\\ \;\;\;\;1\\ \mathbf{elif}\;\alpha \leq 1.95:\\ \;\;\;\;t\_0\\ \mathbf{else}:\\ \;\;\;\;\frac{\beta + 1}{\alpha}\\ \end{array} \end{array} \]
(FPCore (alpha beta)
 :precision binary64
 (let* ((t_0 (+ 0.5 (* alpha -0.25))))
   (if (<= alpha -1.15e-111)
     t_0
     (if (<= alpha -5.4e-151)
       1.0
       (if (<= alpha 1.95) t_0 (/ (+ beta 1.0) alpha))))))
double code(double alpha, double beta) {
	double t_0 = 0.5 + (alpha * -0.25);
	double tmp;
	if (alpha <= -1.15e-111) {
		tmp = t_0;
	} else if (alpha <= -5.4e-151) {
		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 = 0.5d0 + (alpha * (-0.25d0))
    if (alpha <= (-1.15d-111)) then
        tmp = t_0
    else if (alpha <= (-5.4d-151)) 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 = 0.5 + (alpha * -0.25);
	double tmp;
	if (alpha <= -1.15e-111) {
		tmp = t_0;
	} else if (alpha <= -5.4e-151) {
		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 = 0.5 + (alpha * -0.25)
	tmp = 0
	if alpha <= -1.15e-111:
		tmp = t_0
	elif alpha <= -5.4e-151:
		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(0.5 + Float64(alpha * -0.25))
	tmp = 0.0
	if (alpha <= -1.15e-111)
		tmp = t_0;
	elseif (alpha <= -5.4e-151)
		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 = 0.5 + (alpha * -0.25);
	tmp = 0.0;
	if (alpha <= -1.15e-111)
		tmp = t_0;
	elseif (alpha <= -5.4e-151)
		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[(0.5 + N[(alpha * -0.25), $MachinePrecision]), $MachinePrecision]}, If[LessEqual[alpha, -1.15e-111], t$95$0, If[LessEqual[alpha, -5.4e-151], 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 := 0.5 + \alpha \cdot -0.25\\
\mathbf{if}\;\alpha \leq -1.15 \cdot 10^{-111}:\\
\;\;\;\;t\_0\\

\mathbf{elif}\;\alpha \leq -5.4 \cdot 10^{-151}:\\
\;\;\;\;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 < -1.15e-111 or -5.40000000000000014e-151 < 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. Add Preprocessing
    5. Taylor expanded in beta around 0 72.0%

      \[\leadsto \frac{\color{blue}{1 - \frac{\alpha}{2 + \alpha}}}{2} \]
    6. Step-by-step derivation
      1. +-commutative72.0%

        \[\leadsto \frac{1 - \frac{\alpha}{\color{blue}{\alpha + 2}}}{2} \]
    7. Simplified72.0%

      \[\leadsto \frac{\color{blue}{1 - \frac{\alpha}{\alpha + 2}}}{2} \]
    8. Taylor expanded in alpha around 0 71.5%

      \[\leadsto \color{blue}{0.5 + -0.25 \cdot \alpha} \]

    if -1.15e-111 < alpha < -5.40000000000000014e-151

    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. Add Preprocessing
    5. Taylor expanded in beta around inf 91.0%

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

    if 1.94999999999999996 < alpha

    1. Initial program 23.2%

      \[\frac{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1}{2} \]
    2. Step-by-step derivation
      1. +-commutative23.2%

        \[\leadsto \frac{\frac{\beta - \alpha}{\color{blue}{\left(\beta + \alpha\right)} + 2} + 1}{2} \]
    3. Simplified23.2%

      \[\leadsto \color{blue}{\frac{\frac{\beta - \alpha}{\left(\beta + \alpha\right) + 2} + 1}{2}} \]
    4. Add Preprocessing
    5. Taylor expanded in alpha around inf 82.6%

      \[\leadsto \color{blue}{0.5 \cdot \frac{2 + 2 \cdot \beta}{\alpha}} \]
    6. Step-by-step derivation
      1. associate-*r/82.6%

        \[\leadsto \color{blue}{\frac{0.5 \cdot \left(2 + 2 \cdot \beta\right)}{\alpha}} \]
      2. distribute-lft-in82.6%

        \[\leadsto \frac{\color{blue}{0.5 \cdot 2 + 0.5 \cdot \left(2 \cdot \beta\right)}}{\alpha} \]
      3. metadata-eval82.6%

        \[\leadsto \frac{\color{blue}{1} + 0.5 \cdot \left(2 \cdot \beta\right)}{\alpha} \]
      4. associate-*r*82.6%

        \[\leadsto \frac{1 + \color{blue}{\left(0.5 \cdot 2\right) \cdot \beta}}{\alpha} \]
      5. metadata-eval82.6%

        \[\leadsto \frac{1 + \color{blue}{1} \cdot \beta}{\alpha} \]
    7. Simplified82.6%

      \[\leadsto \color{blue}{\frac{1 + 1 \cdot \beta}{\alpha}} \]
    8. Taylor expanded in beta around 0 82.6%

      \[\leadsto \color{blue}{\frac{1}{\alpha} + \frac{\beta}{\alpha}} \]
    9. Step-by-step derivation
      1. +-commutative82.6%

        \[\leadsto \color{blue}{\frac{\beta}{\alpha} + \frac{1}{\alpha}} \]
      2. *-lft-identity82.6%

        \[\leadsto \frac{\color{blue}{1 \cdot \beta}}{\alpha} + \frac{1}{\alpha} \]
      3. associate-*l/82.6%

        \[\leadsto \color{blue}{\frac{1}{\alpha} \cdot \beta} + \frac{1}{\alpha} \]
      4. *-rgt-identity82.6%

        \[\leadsto \frac{1}{\alpha} \cdot \beta + \color{blue}{\frac{1}{\alpha} \cdot 1} \]
      5. distribute-lft-in82.6%

        \[\leadsto \color{blue}{\frac{1}{\alpha} \cdot \left(\beta + 1\right)} \]
      6. associate-*l/82.6%

        \[\leadsto \color{blue}{\frac{1 \cdot \left(\beta + 1\right)}{\alpha}} \]
      7. *-lft-identity82.6%

        \[\leadsto \frac{\color{blue}{\beta + 1}}{\alpha} \]
    10. Simplified82.6%

      \[\leadsto \color{blue}{\frac{\beta + 1}{\alpha}} \]
  3. Recombined 3 regimes into one program.
  4. Final simplification75.9%

    \[\leadsto \begin{array}{l} \mathbf{if}\;\alpha \leq -1.15 \cdot 10^{-111}:\\ \;\;\;\;0.5 + \alpha \cdot -0.25\\ \mathbf{elif}\;\alpha \leq -5.4 \cdot 10^{-151}:\\ \;\;\;\;1\\ \mathbf{elif}\;\alpha \leq 1.95:\\ \;\;\;\;0.5 + \alpha \cdot -0.25\\ \mathbf{else}:\\ \;\;\;\;\frac{\beta + 1}{\alpha}\\ \end{array} \]
  5. Add Preprocessing

Alternative 3: 70.4% accurate, 0.8× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;\beta \leq 1.02 \cdot 10^{-41}:\\ \;\;\;\;0.5\\ \mathbf{elif}\;\beta \leq 7.5 \cdot 10^{-34}:\\ \;\;\;\;\frac{1}{\alpha}\\ \mathbf{elif}\;\beta \leq 2.05:\\ \;\;\;\;0.5\\ \mathbf{else}:\\ \;\;\;\;1\\ \end{array} \end{array} \]
(FPCore (alpha beta)
 :precision binary64
 (if (<= beta 1.02e-41)
   0.5
   (if (<= beta 7.5e-34) (/ 1.0 alpha) (if (<= beta 2.05) 0.5 1.0))))
double code(double alpha, double beta) {
	double tmp;
	if (beta <= 1.02e-41) {
		tmp = 0.5;
	} else if (beta <= 7.5e-34) {
		tmp = 1.0 / alpha;
	} else if (beta <= 2.05) {
		tmp = 0.5;
	} else {
		tmp = 1.0;
	}
	return tmp;
}
real(8) function code(alpha, beta)
    real(8), intent (in) :: alpha
    real(8), intent (in) :: beta
    real(8) :: tmp
    if (beta <= 1.02d-41) then
        tmp = 0.5d0
    else if (beta <= 7.5d-34) then
        tmp = 1.0d0 / alpha
    else if (beta <= 2.05d0) then
        tmp = 0.5d0
    else
        tmp = 1.0d0
    end if
    code = tmp
end function
public static double code(double alpha, double beta) {
	double tmp;
	if (beta <= 1.02e-41) {
		tmp = 0.5;
	} else if (beta <= 7.5e-34) {
		tmp = 1.0 / alpha;
	} else if (beta <= 2.05) {
		tmp = 0.5;
	} else {
		tmp = 1.0;
	}
	return tmp;
}
def code(alpha, beta):
	tmp = 0
	if beta <= 1.02e-41:
		tmp = 0.5
	elif beta <= 7.5e-34:
		tmp = 1.0 / alpha
	elif beta <= 2.05:
		tmp = 0.5
	else:
		tmp = 1.0
	return tmp
function code(alpha, beta)
	tmp = 0.0
	if (beta <= 1.02e-41)
		tmp = 0.5;
	elseif (beta <= 7.5e-34)
		tmp = Float64(1.0 / alpha);
	elseif (beta <= 2.05)
		tmp = 0.5;
	else
		tmp = 1.0;
	end
	return tmp
end
function tmp_2 = code(alpha, beta)
	tmp = 0.0;
	if (beta <= 1.02e-41)
		tmp = 0.5;
	elseif (beta <= 7.5e-34)
		tmp = 1.0 / alpha;
	elseif (beta <= 2.05)
		tmp = 0.5;
	else
		tmp = 1.0;
	end
	tmp_2 = tmp;
end
code[alpha_, beta_] := If[LessEqual[beta, 1.02e-41], 0.5, If[LessEqual[beta, 7.5e-34], N[(1.0 / alpha), $MachinePrecision], If[LessEqual[beta, 2.05], 0.5, 1.0]]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;\beta \leq 1.02 \cdot 10^{-41}:\\
\;\;\;\;0.5\\

\mathbf{elif}\;\beta \leq 7.5 \cdot 10^{-34}:\\
\;\;\;\;\frac{1}{\alpha}\\

\mathbf{elif}\;\beta \leq 2.05:\\
\;\;\;\;0.5\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if beta < 1.02e-41 or 7.5000000000000004e-34 < beta < 2.0499999999999998

    1. Initial program 71.3%

      \[\frac{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1}{2} \]
    2. Step-by-step derivation
      1. +-commutative71.3%

        \[\leadsto \frac{\frac{\beta - \alpha}{\color{blue}{\left(\beta + \alpha\right)} + 2} + 1}{2} \]
    3. Simplified71.3%

      \[\leadsto \color{blue}{\frac{\frac{\beta - \alpha}{\left(\beta + \alpha\right) + 2} + 1}{2}} \]
    4. Add Preprocessing
    5. Taylor expanded in beta around 0 70.3%

      \[\leadsto \frac{\color{blue}{1 - \frac{\alpha}{2 + \alpha}}}{2} \]
    6. Step-by-step derivation
      1. +-commutative70.3%

        \[\leadsto \frac{1 - \frac{\alpha}{\color{blue}{\alpha + 2}}}{2} \]
    7. Simplified70.3%

      \[\leadsto \frac{\color{blue}{1 - \frac{\alpha}{\alpha + 2}}}{2} \]
    8. Taylor expanded in alpha around 0 68.3%

      \[\leadsto \color{blue}{0.5} \]

    if 1.02e-41 < beta < 7.5000000000000004e-34

    1. Initial program 5.9%

      \[\frac{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1}{2} \]
    2. Step-by-step derivation
      1. +-commutative5.9%

        \[\leadsto \frac{\frac{\beta - \alpha}{\color{blue}{\left(\beta + \alpha\right)} + 2} + 1}{2} \]
    3. Simplified5.9%

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

      \[\leadsto \color{blue}{0.5 \cdot \frac{2 + 2 \cdot \beta}{\alpha}} \]
    6. Step-by-step derivation
      1. associate-*r/100.0%

        \[\leadsto \color{blue}{\frac{0.5 \cdot \left(2 + 2 \cdot \beta\right)}{\alpha}} \]
      2. distribute-lft-in100.0%

        \[\leadsto \frac{\color{blue}{0.5 \cdot 2 + 0.5 \cdot \left(2 \cdot \beta\right)}}{\alpha} \]
      3. metadata-eval100.0%

        \[\leadsto \frac{\color{blue}{1} + 0.5 \cdot \left(2 \cdot \beta\right)}{\alpha} \]
      4. associate-*r*100.0%

        \[\leadsto \frac{1 + \color{blue}{\left(0.5 \cdot 2\right) \cdot \beta}}{\alpha} \]
      5. metadata-eval100.0%

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

      \[\leadsto \color{blue}{\frac{1 + 1 \cdot \beta}{\alpha}} \]
    8. Taylor expanded in beta around 0 100.0%

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

    if 2.0499999999999998 < beta

    1. Initial program 83.5%

      \[\frac{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1}{2} \]
    2. Step-by-step derivation
      1. +-commutative83.5%

        \[\leadsto \frac{\frac{\beta - \alpha}{\color{blue}{\left(\beta + \alpha\right)} + 2} + 1}{2} \]
    3. Simplified83.5%

      \[\leadsto \color{blue}{\frac{\frac{\beta - \alpha}{\left(\beta + \alpha\right) + 2} + 1}{2}} \]
    4. Add Preprocessing
    5. Taylor expanded in beta around inf 82.9%

      \[\leadsto \frac{\color{blue}{2}}{2} \]
  3. Recombined 3 regimes into one program.
  4. Final simplification74.2%

    \[\leadsto \begin{array}{l} \mathbf{if}\;\beta \leq 1.02 \cdot 10^{-41}:\\ \;\;\;\;0.5\\ \mathbf{elif}\;\beta \leq 7.5 \cdot 10^{-34}:\\ \;\;\;\;\frac{1}{\alpha}\\ \mathbf{elif}\;\beta \leq 2.05:\\ \;\;\;\;0.5\\ \mathbf{else}:\\ \;\;\;\;1\\ \end{array} \]
  5. Add Preprocessing

Alternative 4: 93.7% accurate, 0.9× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;\alpha \leq 6.6 \cdot 10^{+16}:\\ \;\;\;\;\frac{1 + \frac{\beta}{\beta + 2}}{2}\\ \mathbf{else}:\\ \;\;\;\;\frac{\beta + 1}{\alpha}\\ \end{array} \end{array} \]
(FPCore (alpha beta)
 :precision binary64
 (if (<= alpha 6.6e+16)
   (/ (+ 1.0 (/ beta (+ beta 2.0))) 2.0)
   (/ (+ beta 1.0) alpha)))
double code(double alpha, double beta) {
	double tmp;
	if (alpha <= 6.6e+16) {
		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 <= 6.6d+16) 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 <= 6.6e+16) {
		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 <= 6.6e+16:
		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 <= 6.6e+16)
		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 <= 6.6e+16)
		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, 6.6e+16], 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 6.6 \cdot 10^{+16}:\\
\;\;\;\;\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 < 6.6e16

    1. Initial program 99.5%

      \[\frac{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1}{2} \]
    2. Step-by-step derivation
      1. +-commutative99.5%

        \[\leadsto \frac{\frac{\beta - \alpha}{\color{blue}{\left(\beta + \alpha\right)} + 2} + 1}{2} \]
    3. Simplified99.5%

      \[\leadsto \color{blue}{\frac{\frac{\beta - \alpha}{\left(\beta + \alpha\right) + 2} + 1}{2}} \]
    4. Add Preprocessing
    5. Taylor expanded in alpha around 0 97.7%

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

    if 6.6e16 < alpha

    1. Initial program 19.4%

      \[\frac{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1}{2} \]
    2. Step-by-step derivation
      1. +-commutative19.4%

        \[\leadsto \frac{\frac{\beta - \alpha}{\color{blue}{\left(\beta + \alpha\right)} + 2} + 1}{2} \]
    3. Simplified19.4%

      \[\leadsto \color{blue}{\frac{\frac{\beta - \alpha}{\left(\beta + \alpha\right) + 2} + 1}{2}} \]
    4. Add Preprocessing
    5. Taylor expanded in alpha around inf 85.9%

      \[\leadsto \color{blue}{0.5 \cdot \frac{2 + 2 \cdot \beta}{\alpha}} \]
    6. Step-by-step derivation
      1. associate-*r/85.9%

        \[\leadsto \color{blue}{\frac{0.5 \cdot \left(2 + 2 \cdot \beta\right)}{\alpha}} \]
      2. distribute-lft-in85.9%

        \[\leadsto \frac{\color{blue}{0.5 \cdot 2 + 0.5 \cdot \left(2 \cdot \beta\right)}}{\alpha} \]
      3. metadata-eval85.9%

        \[\leadsto \frac{\color{blue}{1} + 0.5 \cdot \left(2 \cdot \beta\right)}{\alpha} \]
      4. associate-*r*85.9%

        \[\leadsto \frac{1 + \color{blue}{\left(0.5 \cdot 2\right) \cdot \beta}}{\alpha} \]
      5. metadata-eval85.9%

        \[\leadsto \frac{1 + \color{blue}{1} \cdot \beta}{\alpha} \]
    7. Simplified85.9%

      \[\leadsto \color{blue}{\frac{1 + 1 \cdot \beta}{\alpha}} \]
    8. Taylor expanded in beta around 0 85.9%

      \[\leadsto \color{blue}{\frac{1}{\alpha} + \frac{\beta}{\alpha}} \]
    9. Step-by-step derivation
      1. +-commutative85.9%

        \[\leadsto \color{blue}{\frac{\beta}{\alpha} + \frac{1}{\alpha}} \]
      2. *-lft-identity85.9%

        \[\leadsto \frac{\color{blue}{1 \cdot \beta}}{\alpha} + \frac{1}{\alpha} \]
      3. associate-*l/85.8%

        \[\leadsto \color{blue}{\frac{1}{\alpha} \cdot \beta} + \frac{1}{\alpha} \]
      4. *-rgt-identity85.8%

        \[\leadsto \frac{1}{\alpha} \cdot \beta + \color{blue}{\frac{1}{\alpha} \cdot 1} \]
      5. distribute-lft-in85.8%

        \[\leadsto \color{blue}{\frac{1}{\alpha} \cdot \left(\beta + 1\right)} \]
      6. associate-*l/85.9%

        \[\leadsto \color{blue}{\frac{1 \cdot \left(\beta + 1\right)}{\alpha}} \]
      7. *-lft-identity85.9%

        \[\leadsto \frac{\color{blue}{\beta + 1}}{\alpha} \]
    10. Simplified85.9%

      \[\leadsto \color{blue}{\frac{\beta + 1}{\alpha}} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification94.0%

    \[\leadsto \begin{array}{l} \mathbf{if}\;\alpha \leq 6.6 \cdot 10^{+16}:\\ \;\;\;\;\frac{1 + \frac{\beta}{\beta + 2}}{2}\\ \mathbf{else}:\\ \;\;\;\;\frac{\beta + 1}{\alpha}\\ \end{array} \]
  5. Add Preprocessing

Alternative 5: 68.8% accurate, 1.6× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;\alpha \leq 4.7:\\ \;\;\;\;0.5\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{\alpha}\\ \end{array} \end{array} \]
(FPCore (alpha beta) :precision binary64 (if (<= alpha 4.7) 0.5 (/ 1.0 alpha)))
double code(double alpha, double beta) {
	double tmp;
	if (alpha <= 4.7) {
		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 <= 4.7d0) 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 <= 4.7) {
		tmp = 0.5;
	} else {
		tmp = 1.0 / alpha;
	}
	return tmp;
}
def code(alpha, beta):
	tmp = 0
	if alpha <= 4.7:
		tmp = 0.5
	else:
		tmp = 1.0 / alpha
	return tmp
function code(alpha, beta)
	tmp = 0.0
	if (alpha <= 4.7)
		tmp = 0.5;
	else
		tmp = Float64(1.0 / alpha);
	end
	return tmp
end
function tmp_2 = code(alpha, beta)
	tmp = 0.0;
	if (alpha <= 4.7)
		tmp = 0.5;
	else
		tmp = 1.0 / alpha;
	end
	tmp_2 = tmp;
end
code[alpha_, beta_] := If[LessEqual[alpha, 4.7], 0.5, N[(1.0 / alpha), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;\alpha \leq 4.7:\\
\;\;\;\;0.5\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if alpha < 4.70000000000000018

    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. Add Preprocessing
    5. Taylor expanded in beta around 0 69.3%

      \[\leadsto \frac{\color{blue}{1 - \frac{\alpha}{2 + \alpha}}}{2} \]
    6. Step-by-step derivation
      1. +-commutative69.3%

        \[\leadsto \frac{1 - \frac{\alpha}{\color{blue}{\alpha + 2}}}{2} \]
    7. Simplified69.3%

      \[\leadsto \frac{\color{blue}{1 - \frac{\alpha}{\alpha + 2}}}{2} \]
    8. Taylor expanded in alpha around 0 68.0%

      \[\leadsto \color{blue}{0.5} \]

    if 4.70000000000000018 < alpha

    1. Initial program 22.2%

      \[\frac{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1}{2} \]
    2. Step-by-step derivation
      1. +-commutative22.2%

        \[\leadsto \frac{\frac{\beta - \alpha}{\color{blue}{\left(\beta + \alpha\right)} + 2} + 1}{2} \]
    3. Simplified22.2%

      \[\leadsto \color{blue}{\frac{\frac{\beta - \alpha}{\left(\beta + \alpha\right) + 2} + 1}{2}} \]
    4. Add Preprocessing
    5. Taylor expanded in alpha around inf 83.6%

      \[\leadsto \color{blue}{0.5 \cdot \frac{2 + 2 \cdot \beta}{\alpha}} \]
    6. Step-by-step derivation
      1. associate-*r/83.6%

        \[\leadsto \color{blue}{\frac{0.5 \cdot \left(2 + 2 \cdot \beta\right)}{\alpha}} \]
      2. distribute-lft-in83.6%

        \[\leadsto \frac{\color{blue}{0.5 \cdot 2 + 0.5 \cdot \left(2 \cdot \beta\right)}}{\alpha} \]
      3. metadata-eval83.6%

        \[\leadsto \frac{\color{blue}{1} + 0.5 \cdot \left(2 \cdot \beta\right)}{\alpha} \]
      4. associate-*r*83.6%

        \[\leadsto \frac{1 + \color{blue}{\left(0.5 \cdot 2\right) \cdot \beta}}{\alpha} \]
      5. metadata-eval83.6%

        \[\leadsto \frac{1 + \color{blue}{1} \cdot \beta}{\alpha} \]
    7. Simplified83.6%

      \[\leadsto \color{blue}{\frac{1 + 1 \cdot \beta}{\alpha}} \]
    8. Taylor expanded in beta around 0 65.3%

      \[\leadsto \color{blue}{\frac{1}{\alpha}} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification67.1%

    \[\leadsto \begin{array}{l} \mathbf{if}\;\alpha \leq 4.7:\\ \;\;\;\;0.5\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{\alpha}\\ \end{array} \]
  5. Add Preprocessing

Alternative 6: 49.0% 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 74.5%

    \[\frac{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1}{2} \]
  2. Step-by-step derivation
    1. +-commutative74.5%

      \[\leadsto \frac{\frac{\beta - \alpha}{\color{blue}{\left(\beta + \alpha\right)} + 2} + 1}{2} \]
  3. Simplified74.5%

    \[\leadsto \color{blue}{\frac{\frac{\beta - \alpha}{\left(\beta + \alpha\right) + 2} + 1}{2}} \]
  4. Add Preprocessing
  5. Taylor expanded in beta around 0 48.6%

    \[\leadsto \frac{\color{blue}{1 - \frac{\alpha}{2 + \alpha}}}{2} \]
  6. Step-by-step derivation
    1. +-commutative48.6%

      \[\leadsto \frac{1 - \frac{\alpha}{\color{blue}{\alpha + 2}}}{2} \]
  7. Simplified48.6%

    \[\leadsto \frac{\color{blue}{1 - \frac{\alpha}{\alpha + 2}}}{2} \]
  8. Taylor expanded in alpha around 0 48.2%

    \[\leadsto \color{blue}{0.5} \]
  9. Final simplification48.2%

    \[\leadsto 0.5 \]
  10. Add Preprocessing

Reproduce

?
herbie shell --seed 2024050 
(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))