Octave 3.8, jcobi/3

Percentage Accurate: 94.3% → 99.6%
Time: 12.0s
Alternatives: 22
Speedup: 3.2×

Specification

?
\[\alpha > -1 \land \beta > -1\]
\[\begin{array}{l} \\ \begin{array}{l} t_0 := \left(\alpha + \beta\right) + 2 \cdot 1\\ \frac{\frac{\frac{\left(\left(\alpha + \beta\right) + \beta \cdot \alpha\right) + 1}{t\_0}}{t\_0}}{t\_0 + 1} \end{array} \end{array} \]
(FPCore (alpha beta)
 :precision binary64
 (let* ((t_0 (+ (+ alpha beta) (* 2.0 1.0))))
   (/ (/ (/ (+ (+ (+ alpha beta) (* beta alpha)) 1.0) t_0) t_0) (+ t_0 1.0))))
double code(double alpha, double beta) {
	double t_0 = (alpha + beta) + (2.0 * 1.0);
	return (((((alpha + beta) + (beta * alpha)) + 1.0) / t_0) / t_0) / (t_0 + 1.0);
}
real(8) function code(alpha, beta)
    real(8), intent (in) :: alpha
    real(8), intent (in) :: beta
    real(8) :: t_0
    t_0 = (alpha + beta) + (2.0d0 * 1.0d0)
    code = (((((alpha + beta) + (beta * alpha)) + 1.0d0) / t_0) / t_0) / (t_0 + 1.0d0)
end function
public static double code(double alpha, double beta) {
	double t_0 = (alpha + beta) + (2.0 * 1.0);
	return (((((alpha + beta) + (beta * alpha)) + 1.0) / t_0) / t_0) / (t_0 + 1.0);
}
def code(alpha, beta):
	t_0 = (alpha + beta) + (2.0 * 1.0)
	return (((((alpha + beta) + (beta * alpha)) + 1.0) / t_0) / t_0) / (t_0 + 1.0)
function code(alpha, beta)
	t_0 = Float64(Float64(alpha + beta) + Float64(2.0 * 1.0))
	return Float64(Float64(Float64(Float64(Float64(Float64(alpha + beta) + Float64(beta * alpha)) + 1.0) / t_0) / t_0) / Float64(t_0 + 1.0))
end
function tmp = code(alpha, beta)
	t_0 = (alpha + beta) + (2.0 * 1.0);
	tmp = (((((alpha + beta) + (beta * alpha)) + 1.0) / t_0) / t_0) / (t_0 + 1.0);
end
code[alpha_, beta_] := Block[{t$95$0 = N[(N[(alpha + beta), $MachinePrecision] + N[(2.0 * 1.0), $MachinePrecision]), $MachinePrecision]}, N[(N[(N[(N[(N[(N[(alpha + beta), $MachinePrecision] + N[(beta * alpha), $MachinePrecision]), $MachinePrecision] + 1.0), $MachinePrecision] / t$95$0), $MachinePrecision] / t$95$0), $MachinePrecision] / N[(t$95$0 + 1.0), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \left(\alpha + \beta\right) + 2 \cdot 1\\
\frac{\frac{\frac{\left(\left(\alpha + \beta\right) + \beta \cdot \alpha\right) + 1}{t\_0}}{t\_0}}{t\_0 + 1}
\end{array}
\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 22 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: 94.3% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \left(\alpha + \beta\right) + 2 \cdot 1\\ \frac{\frac{\frac{\left(\left(\alpha + \beta\right) + \beta \cdot \alpha\right) + 1}{t\_0}}{t\_0}}{t\_0 + 1} \end{array} \end{array} \]
(FPCore (alpha beta)
 :precision binary64
 (let* ((t_0 (+ (+ alpha beta) (* 2.0 1.0))))
   (/ (/ (/ (+ (+ (+ alpha beta) (* beta alpha)) 1.0) t_0) t_0) (+ t_0 1.0))))
double code(double alpha, double beta) {
	double t_0 = (alpha + beta) + (2.0 * 1.0);
	return (((((alpha + beta) + (beta * alpha)) + 1.0) / t_0) / t_0) / (t_0 + 1.0);
}
real(8) function code(alpha, beta)
    real(8), intent (in) :: alpha
    real(8), intent (in) :: beta
    real(8) :: t_0
    t_0 = (alpha + beta) + (2.0d0 * 1.0d0)
    code = (((((alpha + beta) + (beta * alpha)) + 1.0d0) / t_0) / t_0) / (t_0 + 1.0d0)
end function
public static double code(double alpha, double beta) {
	double t_0 = (alpha + beta) + (2.0 * 1.0);
	return (((((alpha + beta) + (beta * alpha)) + 1.0) / t_0) / t_0) / (t_0 + 1.0);
}
def code(alpha, beta):
	t_0 = (alpha + beta) + (2.0 * 1.0)
	return (((((alpha + beta) + (beta * alpha)) + 1.0) / t_0) / t_0) / (t_0 + 1.0)
function code(alpha, beta)
	t_0 = Float64(Float64(alpha + beta) + Float64(2.0 * 1.0))
	return Float64(Float64(Float64(Float64(Float64(Float64(alpha + beta) + Float64(beta * alpha)) + 1.0) / t_0) / t_0) / Float64(t_0 + 1.0))
end
function tmp = code(alpha, beta)
	t_0 = (alpha + beta) + (2.0 * 1.0);
	tmp = (((((alpha + beta) + (beta * alpha)) + 1.0) / t_0) / t_0) / (t_0 + 1.0);
end
code[alpha_, beta_] := Block[{t$95$0 = N[(N[(alpha + beta), $MachinePrecision] + N[(2.0 * 1.0), $MachinePrecision]), $MachinePrecision]}, N[(N[(N[(N[(N[(N[(alpha + beta), $MachinePrecision] + N[(beta * alpha), $MachinePrecision]), $MachinePrecision] + 1.0), $MachinePrecision] / t$95$0), $MachinePrecision] / t$95$0), $MachinePrecision] / N[(t$95$0 + 1.0), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \left(\alpha + \beta\right) + 2 \cdot 1\\
\frac{\frac{\frac{\left(\left(\alpha + \beta\right) + \beta \cdot \alpha\right) + 1}{t\_0}}{t\_0}}{t\_0 + 1}
\end{array}
\end{array}

Alternative 1: 99.6% accurate, 0.8× speedup?

\[\begin{array}{l} [alpha, beta] = \mathsf{sort}([alpha, beta])\\ \\ \begin{array}{l} \mathbf{if}\;\beta \leq 2900000000:\\ \;\;\;\;\frac{\frac{\mathsf{fma}\left(\alpha, \beta, \beta + \alpha\right) + 1}{\mathsf{fma}\left(\beta + \alpha, \beta + \alpha, -4\right)}}{\alpha + \left(\beta + 3\right)} \cdot \frac{\left(\beta + \alpha\right) + -2}{\left(\beta + \alpha\right) + 2}\\ \mathbf{else}:\\ \;\;\;\;\frac{\frac{\left(-1 - \alpha\right) \cdot \frac{\mathsf{fma}\left(\alpha, 2, 4\right)}{\beta} + \left(\left(\frac{1}{\beta} + \frac{\alpha}{\beta}\right) + \left(\alpha + 1\right)\right)}{\beta}}{\beta \cdot \left(\frac{\alpha + 3}{\beta} + 1\right)}\\ \end{array} \end{array} \]
NOTE: alpha and beta should be sorted in increasing order before calling this function.
(FPCore (alpha beta)
 :precision binary64
 (if (<= beta 2900000000.0)
   (*
    (/
     (/
      (+ (fma alpha beta (+ beta alpha)) 1.0)
      (fma (+ beta alpha) (+ beta alpha) -4.0))
     (+ alpha (+ beta 3.0)))
    (/ (+ (+ beta alpha) -2.0) (+ (+ beta alpha) 2.0)))
   (/
    (/
     (+
      (* (- -1.0 alpha) (/ (fma alpha 2.0 4.0) beta))
      (+ (+ (/ 1.0 beta) (/ alpha beta)) (+ alpha 1.0)))
     beta)
    (* beta (+ (/ (+ alpha 3.0) beta) 1.0)))))
assert(alpha < beta);
double code(double alpha, double beta) {
	double tmp;
	if (beta <= 2900000000.0) {
		tmp = (((fma(alpha, beta, (beta + alpha)) + 1.0) / fma((beta + alpha), (beta + alpha), -4.0)) / (alpha + (beta + 3.0))) * (((beta + alpha) + -2.0) / ((beta + alpha) + 2.0));
	} else {
		tmp = ((((-1.0 - alpha) * (fma(alpha, 2.0, 4.0) / beta)) + (((1.0 / beta) + (alpha / beta)) + (alpha + 1.0))) / beta) / (beta * (((alpha + 3.0) / beta) + 1.0));
	}
	return tmp;
}
alpha, beta = sort([alpha, beta])
function code(alpha, beta)
	tmp = 0.0
	if (beta <= 2900000000.0)
		tmp = Float64(Float64(Float64(Float64(fma(alpha, beta, Float64(beta + alpha)) + 1.0) / fma(Float64(beta + alpha), Float64(beta + alpha), -4.0)) / Float64(alpha + Float64(beta + 3.0))) * Float64(Float64(Float64(beta + alpha) + -2.0) / Float64(Float64(beta + alpha) + 2.0)));
	else
		tmp = Float64(Float64(Float64(Float64(Float64(-1.0 - alpha) * Float64(fma(alpha, 2.0, 4.0) / beta)) + Float64(Float64(Float64(1.0 / beta) + Float64(alpha / beta)) + Float64(alpha + 1.0))) / beta) / Float64(beta * Float64(Float64(Float64(alpha + 3.0) / beta) + 1.0)));
	end
	return tmp
end
NOTE: alpha and beta should be sorted in increasing order before calling this function.
code[alpha_, beta_] := If[LessEqual[beta, 2900000000.0], N[(N[(N[(N[(N[(alpha * beta + N[(beta + alpha), $MachinePrecision]), $MachinePrecision] + 1.0), $MachinePrecision] / N[(N[(beta + alpha), $MachinePrecision] * N[(beta + alpha), $MachinePrecision] + -4.0), $MachinePrecision]), $MachinePrecision] / N[(alpha + N[(beta + 3.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * N[(N[(N[(beta + alpha), $MachinePrecision] + -2.0), $MachinePrecision] / N[(N[(beta + alpha), $MachinePrecision] + 2.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(N[(N[(N[(N[(-1.0 - alpha), $MachinePrecision] * N[(N[(alpha * 2.0 + 4.0), $MachinePrecision] / beta), $MachinePrecision]), $MachinePrecision] + N[(N[(N[(1.0 / beta), $MachinePrecision] + N[(alpha / beta), $MachinePrecision]), $MachinePrecision] + N[(alpha + 1.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / beta), $MachinePrecision] / N[(beta * N[(N[(N[(alpha + 3.0), $MachinePrecision] / beta), $MachinePrecision] + 1.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
[alpha, beta] = \mathsf{sort}([alpha, beta])\\
\\
\begin{array}{l}
\mathbf{if}\;\beta \leq 2900000000:\\
\;\;\;\;\frac{\frac{\mathsf{fma}\left(\alpha, \beta, \beta + \alpha\right) + 1}{\mathsf{fma}\left(\beta + \alpha, \beta + \alpha, -4\right)}}{\alpha + \left(\beta + 3\right)} \cdot \frac{\left(\beta + \alpha\right) + -2}{\left(\beta + \alpha\right) + 2}\\

\mathbf{else}:\\
\;\;\;\;\frac{\frac{\left(-1 - \alpha\right) \cdot \frac{\mathsf{fma}\left(\alpha, 2, 4\right)}{\beta} + \left(\left(\frac{1}{\beta} + \frac{\alpha}{\beta}\right) + \left(\alpha + 1\right)\right)}{\beta}}{\beta \cdot \left(\frac{\alpha + 3}{\beta} + 1\right)}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if beta < 2.9e9

    1. Initial program 99.9%

      \[\frac{\frac{\frac{\left(\left(\alpha + \beta\right) + \beta \cdot \alpha\right) + 1}{\left(\alpha + \beta\right) + 2 \cdot 1}}{\left(\alpha + \beta\right) + 2 \cdot 1}}{\left(\left(\alpha + \beta\right) + 2 \cdot 1\right) + 1} \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. lift-/.f64N/A

        \[\leadsto \color{blue}{\frac{\frac{\frac{\left(\left(\alpha + \beta\right) + \beta \cdot \alpha\right) + 1}{\left(\alpha + \beta\right) + 2 \cdot 1}}{\left(\alpha + \beta\right) + 2 \cdot 1}}{\left(\left(\alpha + \beta\right) + 2 \cdot 1\right) + 1}} \]
      2. lift-/.f64N/A

        \[\leadsto \frac{\color{blue}{\frac{\frac{\left(\left(\alpha + \beta\right) + \beta \cdot \alpha\right) + 1}{\left(\alpha + \beta\right) + 2 \cdot 1}}{\left(\alpha + \beta\right) + 2 \cdot 1}}}{\left(\left(\alpha + \beta\right) + 2 \cdot 1\right) + 1} \]
      3. associate-/l/N/A

        \[\leadsto \color{blue}{\frac{\frac{\left(\left(\alpha + \beta\right) + \beta \cdot \alpha\right) + 1}{\left(\alpha + \beta\right) + 2 \cdot 1}}{\left(\left(\left(\alpha + \beta\right) + 2 \cdot 1\right) + 1\right) \cdot \left(\left(\alpha + \beta\right) + 2 \cdot 1\right)}} \]
      4. lift-/.f64N/A

        \[\leadsto \frac{\color{blue}{\frac{\left(\left(\alpha + \beta\right) + \beta \cdot \alpha\right) + 1}{\left(\alpha + \beta\right) + 2 \cdot 1}}}{\left(\left(\left(\alpha + \beta\right) + 2 \cdot 1\right) + 1\right) \cdot \left(\left(\alpha + \beta\right) + 2 \cdot 1\right)} \]
      5. lift-+.f64N/A

        \[\leadsto \frac{\frac{\left(\left(\alpha + \beta\right) + \beta \cdot \alpha\right) + 1}{\color{blue}{\left(\alpha + \beta\right) + 2 \cdot 1}}}{\left(\left(\left(\alpha + \beta\right) + 2 \cdot 1\right) + 1\right) \cdot \left(\left(\alpha + \beta\right) + 2 \cdot 1\right)} \]
      6. flip-+N/A

        \[\leadsto \frac{\frac{\left(\left(\alpha + \beta\right) + \beta \cdot \alpha\right) + 1}{\color{blue}{\frac{\left(\alpha + \beta\right) \cdot \left(\alpha + \beta\right) - \left(2 \cdot 1\right) \cdot \left(2 \cdot 1\right)}{\left(\alpha + \beta\right) - 2 \cdot 1}}}}{\left(\left(\left(\alpha + \beta\right) + 2 \cdot 1\right) + 1\right) \cdot \left(\left(\alpha + \beta\right) + 2 \cdot 1\right)} \]
      7. associate-/r/N/A

        \[\leadsto \frac{\color{blue}{\frac{\left(\left(\alpha + \beta\right) + \beta \cdot \alpha\right) + 1}{\left(\alpha + \beta\right) \cdot \left(\alpha + \beta\right) - \left(2 \cdot 1\right) \cdot \left(2 \cdot 1\right)} \cdot \left(\left(\alpha + \beta\right) - 2 \cdot 1\right)}}{\left(\left(\left(\alpha + \beta\right) + 2 \cdot 1\right) + 1\right) \cdot \left(\left(\alpha + \beta\right) + 2 \cdot 1\right)} \]
      8. times-fracN/A

        \[\leadsto \color{blue}{\frac{\frac{\left(\left(\alpha + \beta\right) + \beta \cdot \alpha\right) + 1}{\left(\alpha + \beta\right) \cdot \left(\alpha + \beta\right) - \left(2 \cdot 1\right) \cdot \left(2 \cdot 1\right)}}{\left(\left(\alpha + \beta\right) + 2 \cdot 1\right) + 1} \cdot \frac{\left(\alpha + \beta\right) - 2 \cdot 1}{\left(\alpha + \beta\right) + 2 \cdot 1}} \]
    4. Applied rewrites99.9%

      \[\leadsto \color{blue}{\frac{\frac{\mathsf{fma}\left(\alpha, \beta, \alpha + \beta\right) + 1}{\mathsf{fma}\left(\alpha + \beta, \alpha + \beta, -4\right)}}{\alpha + \left(\beta + 3\right)} \cdot \frac{\left(\alpha + \beta\right) + -2}{\left(\alpha + \beta\right) + 2}} \]

    if 2.9e9 < beta

    1. Initial program 86.7%

      \[\frac{\frac{\frac{\left(\left(\alpha + \beta\right) + \beta \cdot \alpha\right) + 1}{\left(\alpha + \beta\right) + 2 \cdot 1}}{\left(\alpha + \beta\right) + 2 \cdot 1}}{\left(\left(\alpha + \beta\right) + 2 \cdot 1\right) + 1} \]
    2. Add Preprocessing
    3. Taylor expanded in beta around inf

      \[\leadsto \frac{\frac{\color{blue}{1 + \alpha}}{\left(\alpha + \beta\right) + 2 \cdot 1}}{\left(\left(\alpha + \beta\right) + 2 \cdot 1\right) + 1} \]
    4. Step-by-step derivation
      1. lower-+.f6499.4

        \[\leadsto \frac{\frac{\color{blue}{1 + \alpha}}{\left(\alpha + \beta\right) + 2 \cdot 1}}{\left(\left(\alpha + \beta\right) + 2 \cdot 1\right) + 1} \]
    5. Applied rewrites99.4%

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

      \[\leadsto \frac{\frac{1 + \alpha}{\left(\alpha + \beta\right) + 2 \cdot 1}}{\color{blue}{-1 \cdot \left(\beta \cdot \left(-1 \cdot \frac{3 + \alpha}{\beta} - 1\right)\right)}} \]
    7. Step-by-step derivation
      1. associate-*r*N/A

        \[\leadsto \frac{\frac{1 + \alpha}{\left(\alpha + \beta\right) + 2 \cdot 1}}{\color{blue}{\left(-1 \cdot \beta\right) \cdot \left(-1 \cdot \frac{3 + \alpha}{\beta} - 1\right)}} \]
      2. lower-*.f64N/A

        \[\leadsto \frac{\frac{1 + \alpha}{\left(\alpha + \beta\right) + 2 \cdot 1}}{\color{blue}{\left(-1 \cdot \beta\right) \cdot \left(-1 \cdot \frac{3 + \alpha}{\beta} - 1\right)}} \]
      3. mul-1-negN/A

        \[\leadsto \frac{\frac{1 + \alpha}{\left(\alpha + \beta\right) + 2 \cdot 1}}{\color{blue}{\left(\mathsf{neg}\left(\beta\right)\right)} \cdot \left(-1 \cdot \frac{3 + \alpha}{\beta} - 1\right)} \]
      4. lower-neg.f64N/A

        \[\leadsto \frac{\frac{1 + \alpha}{\left(\alpha + \beta\right) + 2 \cdot 1}}{\color{blue}{\left(\mathsf{neg}\left(\beta\right)\right)} \cdot \left(-1 \cdot \frac{3 + \alpha}{\beta} - 1\right)} \]
      5. sub-negN/A

        \[\leadsto \frac{\frac{1 + \alpha}{\left(\alpha + \beta\right) + 2 \cdot 1}}{\left(\mathsf{neg}\left(\beta\right)\right) \cdot \color{blue}{\left(-1 \cdot \frac{3 + \alpha}{\beta} + \left(\mathsf{neg}\left(1\right)\right)\right)}} \]
      6. metadata-evalN/A

        \[\leadsto \frac{\frac{1 + \alpha}{\left(\alpha + \beta\right) + 2 \cdot 1}}{\left(\mathsf{neg}\left(\beta\right)\right) \cdot \left(-1 \cdot \frac{3 + \alpha}{\beta} + \color{blue}{-1}\right)} \]
      7. lower-+.f64N/A

        \[\leadsto \frac{\frac{1 + \alpha}{\left(\alpha + \beta\right) + 2 \cdot 1}}{\left(\mathsf{neg}\left(\beta\right)\right) \cdot \color{blue}{\left(-1 \cdot \frac{3 + \alpha}{\beta} + -1\right)}} \]
      8. mul-1-negN/A

        \[\leadsto \frac{\frac{1 + \alpha}{\left(\alpha + \beta\right) + 2 \cdot 1}}{\left(\mathsf{neg}\left(\beta\right)\right) \cdot \left(\color{blue}{\left(\mathsf{neg}\left(\frac{3 + \alpha}{\beta}\right)\right)} + -1\right)} \]
      9. lower-neg.f64N/A

        \[\leadsto \frac{\frac{1 + \alpha}{\left(\alpha + \beta\right) + 2 \cdot 1}}{\left(\mathsf{neg}\left(\beta\right)\right) \cdot \left(\color{blue}{\left(\mathsf{neg}\left(\frac{3 + \alpha}{\beta}\right)\right)} + -1\right)} \]
      10. lower-/.f64N/A

        \[\leadsto \frac{\frac{1 + \alpha}{\left(\alpha + \beta\right) + 2 \cdot 1}}{\left(\mathsf{neg}\left(\beta\right)\right) \cdot \left(\left(\mathsf{neg}\left(\color{blue}{\frac{3 + \alpha}{\beta}}\right)\right) + -1\right)} \]
      11. lower-+.f6499.4

        \[\leadsto \frac{\frac{1 + \alpha}{\left(\alpha + \beta\right) + 2 \cdot 1}}{\left(-\beta\right) \cdot \left(\left(-\frac{\color{blue}{3 + \alpha}}{\beta}\right) + -1\right)} \]
    8. Applied rewrites99.4%

      \[\leadsto \frac{\frac{1 + \alpha}{\left(\alpha + \beta\right) + 2 \cdot 1}}{\color{blue}{\left(-\beta\right) \cdot \left(\left(-\frac{3 + \alpha}{\beta}\right) + -1\right)}} \]
    9. Taylor expanded in beta around inf

      \[\leadsto \frac{\color{blue}{\frac{\left(1 + \left(\alpha + \left(\frac{1}{\beta} + \frac{\alpha}{\beta}\right)\right)\right) - \frac{\left(1 + \alpha\right) \cdot \left(4 + 2 \cdot \alpha\right)}{\beta}}{\beta}}}{\left(\mathsf{neg}\left(\beta\right)\right) \cdot \left(\left(\mathsf{neg}\left(\frac{3 + \alpha}{\beta}\right)\right) + -1\right)} \]
    10. Step-by-step derivation
      1. lower-/.f64N/A

        \[\leadsto \frac{\color{blue}{\frac{\left(1 + \left(\alpha + \left(\frac{1}{\beta} + \frac{\alpha}{\beta}\right)\right)\right) - \frac{\left(1 + \alpha\right) \cdot \left(4 + 2 \cdot \alpha\right)}{\beta}}{\beta}}}{\left(\mathsf{neg}\left(\beta\right)\right) \cdot \left(\left(\mathsf{neg}\left(\frac{3 + \alpha}{\beta}\right)\right) + -1\right)} \]
    11. Applied rewrites99.8%

      \[\leadsto \frac{\color{blue}{\frac{\left(\left(\alpha + 1\right) + \left(\frac{1}{\beta} + \frac{\alpha}{\beta}\right)\right) + \left(-1 - \alpha\right) \cdot \frac{\mathsf{fma}\left(\alpha, 2, 4\right)}{\beta}}{\beta}}}{\left(-\beta\right) \cdot \left(\left(-\frac{3 + \alpha}{\beta}\right) + -1\right)} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification99.9%

    \[\leadsto \begin{array}{l} \mathbf{if}\;\beta \leq 2900000000:\\ \;\;\;\;\frac{\frac{\mathsf{fma}\left(\alpha, \beta, \beta + \alpha\right) + 1}{\mathsf{fma}\left(\beta + \alpha, \beta + \alpha, -4\right)}}{\alpha + \left(\beta + 3\right)} \cdot \frac{\left(\beta + \alpha\right) + -2}{\left(\beta + \alpha\right) + 2}\\ \mathbf{else}:\\ \;\;\;\;\frac{\frac{\left(-1 - \alpha\right) \cdot \frac{\mathsf{fma}\left(\alpha, 2, 4\right)}{\beta} + \left(\left(\frac{1}{\beta} + \frac{\alpha}{\beta}\right) + \left(\alpha + 1\right)\right)}{\beta}}{\beta \cdot \left(\frac{\alpha + 3}{\beta} + 1\right)}\\ \end{array} \]
  5. Add Preprocessing

Alternative 2: 99.6% accurate, 0.9× speedup?

\[\begin{array}{l} [alpha, beta] = \mathsf{sort}([alpha, beta])\\ \\ \begin{array}{l} t_0 := \left(\beta + \alpha\right) + 2\\ \mathbf{if}\;\beta \leq 2900000000:\\ \;\;\;\;\frac{\frac{\mathsf{fma}\left(\alpha, \beta, \beta + \alpha\right) + 1}{\mathsf{fma}\left(\beta + \alpha, \beta + \alpha, -4\right)}}{\alpha + \left(\beta + 3\right)} \cdot \frac{\left(\beta + \alpha\right) + -2}{t\_0}\\ \mathbf{else}:\\ \;\;\;\;\frac{\frac{\left(\left(\frac{1}{\beta} + \frac{\alpha}{\beta}\right) + \left(\alpha + 1\right)\right) + \left(-1 - \alpha\right) \cdot \frac{\mathsf{fma}\left(2, \alpha, 4\right)}{\beta}}{\beta}}{t\_0 + 1}\\ \end{array} \end{array} \]
NOTE: alpha and beta should be sorted in increasing order before calling this function.
(FPCore (alpha beta)
 :precision binary64
 (let* ((t_0 (+ (+ beta alpha) 2.0)))
   (if (<= beta 2900000000.0)
     (*
      (/
       (/
        (+ (fma alpha beta (+ beta alpha)) 1.0)
        (fma (+ beta alpha) (+ beta alpha) -4.0))
       (+ alpha (+ beta 3.0)))
      (/ (+ (+ beta alpha) -2.0) t_0))
     (/
      (/
       (+
        (+ (+ (/ 1.0 beta) (/ alpha beta)) (+ alpha 1.0))
        (* (- -1.0 alpha) (/ (fma 2.0 alpha 4.0) beta)))
       beta)
      (+ t_0 1.0)))))
assert(alpha < beta);
double code(double alpha, double beta) {
	double t_0 = (beta + alpha) + 2.0;
	double tmp;
	if (beta <= 2900000000.0) {
		tmp = (((fma(alpha, beta, (beta + alpha)) + 1.0) / fma((beta + alpha), (beta + alpha), -4.0)) / (alpha + (beta + 3.0))) * (((beta + alpha) + -2.0) / t_0);
	} else {
		tmp = (((((1.0 / beta) + (alpha / beta)) + (alpha + 1.0)) + ((-1.0 - alpha) * (fma(2.0, alpha, 4.0) / beta))) / beta) / (t_0 + 1.0);
	}
	return tmp;
}
alpha, beta = sort([alpha, beta])
function code(alpha, beta)
	t_0 = Float64(Float64(beta + alpha) + 2.0)
	tmp = 0.0
	if (beta <= 2900000000.0)
		tmp = Float64(Float64(Float64(Float64(fma(alpha, beta, Float64(beta + alpha)) + 1.0) / fma(Float64(beta + alpha), Float64(beta + alpha), -4.0)) / Float64(alpha + Float64(beta + 3.0))) * Float64(Float64(Float64(beta + alpha) + -2.0) / t_0));
	else
		tmp = Float64(Float64(Float64(Float64(Float64(Float64(1.0 / beta) + Float64(alpha / beta)) + Float64(alpha + 1.0)) + Float64(Float64(-1.0 - alpha) * Float64(fma(2.0, alpha, 4.0) / beta))) / beta) / Float64(t_0 + 1.0));
	end
	return tmp
end
NOTE: alpha and beta should be sorted in increasing order before calling this function.
code[alpha_, beta_] := Block[{t$95$0 = N[(N[(beta + alpha), $MachinePrecision] + 2.0), $MachinePrecision]}, If[LessEqual[beta, 2900000000.0], N[(N[(N[(N[(N[(alpha * beta + N[(beta + alpha), $MachinePrecision]), $MachinePrecision] + 1.0), $MachinePrecision] / N[(N[(beta + alpha), $MachinePrecision] * N[(beta + alpha), $MachinePrecision] + -4.0), $MachinePrecision]), $MachinePrecision] / N[(alpha + N[(beta + 3.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * N[(N[(N[(beta + alpha), $MachinePrecision] + -2.0), $MachinePrecision] / t$95$0), $MachinePrecision]), $MachinePrecision], N[(N[(N[(N[(N[(N[(1.0 / beta), $MachinePrecision] + N[(alpha / beta), $MachinePrecision]), $MachinePrecision] + N[(alpha + 1.0), $MachinePrecision]), $MachinePrecision] + N[(N[(-1.0 - alpha), $MachinePrecision] * N[(N[(2.0 * alpha + 4.0), $MachinePrecision] / beta), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / beta), $MachinePrecision] / N[(t$95$0 + 1.0), $MachinePrecision]), $MachinePrecision]]]
\begin{array}{l}
[alpha, beta] = \mathsf{sort}([alpha, beta])\\
\\
\begin{array}{l}
t_0 := \left(\beta + \alpha\right) + 2\\
\mathbf{if}\;\beta \leq 2900000000:\\
\;\;\;\;\frac{\frac{\mathsf{fma}\left(\alpha, \beta, \beta + \alpha\right) + 1}{\mathsf{fma}\left(\beta + \alpha, \beta + \alpha, -4\right)}}{\alpha + \left(\beta + 3\right)} \cdot \frac{\left(\beta + \alpha\right) + -2}{t\_0}\\

\mathbf{else}:\\
\;\;\;\;\frac{\frac{\left(\left(\frac{1}{\beta} + \frac{\alpha}{\beta}\right) + \left(\alpha + 1\right)\right) + \left(-1 - \alpha\right) \cdot \frac{\mathsf{fma}\left(2, \alpha, 4\right)}{\beta}}{\beta}}{t\_0 + 1}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if beta < 2.9e9

    1. Initial program 99.9%

      \[\frac{\frac{\frac{\left(\left(\alpha + \beta\right) + \beta \cdot \alpha\right) + 1}{\left(\alpha + \beta\right) + 2 \cdot 1}}{\left(\alpha + \beta\right) + 2 \cdot 1}}{\left(\left(\alpha + \beta\right) + 2 \cdot 1\right) + 1} \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. lift-/.f64N/A

        \[\leadsto \color{blue}{\frac{\frac{\frac{\left(\left(\alpha + \beta\right) + \beta \cdot \alpha\right) + 1}{\left(\alpha + \beta\right) + 2 \cdot 1}}{\left(\alpha + \beta\right) + 2 \cdot 1}}{\left(\left(\alpha + \beta\right) + 2 \cdot 1\right) + 1}} \]
      2. lift-/.f64N/A

        \[\leadsto \frac{\color{blue}{\frac{\frac{\left(\left(\alpha + \beta\right) + \beta \cdot \alpha\right) + 1}{\left(\alpha + \beta\right) + 2 \cdot 1}}{\left(\alpha + \beta\right) + 2 \cdot 1}}}{\left(\left(\alpha + \beta\right) + 2 \cdot 1\right) + 1} \]
      3. associate-/l/N/A

        \[\leadsto \color{blue}{\frac{\frac{\left(\left(\alpha + \beta\right) + \beta \cdot \alpha\right) + 1}{\left(\alpha + \beta\right) + 2 \cdot 1}}{\left(\left(\left(\alpha + \beta\right) + 2 \cdot 1\right) + 1\right) \cdot \left(\left(\alpha + \beta\right) + 2 \cdot 1\right)}} \]
      4. lift-/.f64N/A

        \[\leadsto \frac{\color{blue}{\frac{\left(\left(\alpha + \beta\right) + \beta \cdot \alpha\right) + 1}{\left(\alpha + \beta\right) + 2 \cdot 1}}}{\left(\left(\left(\alpha + \beta\right) + 2 \cdot 1\right) + 1\right) \cdot \left(\left(\alpha + \beta\right) + 2 \cdot 1\right)} \]
      5. lift-+.f64N/A

        \[\leadsto \frac{\frac{\left(\left(\alpha + \beta\right) + \beta \cdot \alpha\right) + 1}{\color{blue}{\left(\alpha + \beta\right) + 2 \cdot 1}}}{\left(\left(\left(\alpha + \beta\right) + 2 \cdot 1\right) + 1\right) \cdot \left(\left(\alpha + \beta\right) + 2 \cdot 1\right)} \]
      6. flip-+N/A

        \[\leadsto \frac{\frac{\left(\left(\alpha + \beta\right) + \beta \cdot \alpha\right) + 1}{\color{blue}{\frac{\left(\alpha + \beta\right) \cdot \left(\alpha + \beta\right) - \left(2 \cdot 1\right) \cdot \left(2 \cdot 1\right)}{\left(\alpha + \beta\right) - 2 \cdot 1}}}}{\left(\left(\left(\alpha + \beta\right) + 2 \cdot 1\right) + 1\right) \cdot \left(\left(\alpha + \beta\right) + 2 \cdot 1\right)} \]
      7. associate-/r/N/A

        \[\leadsto \frac{\color{blue}{\frac{\left(\left(\alpha + \beta\right) + \beta \cdot \alpha\right) + 1}{\left(\alpha + \beta\right) \cdot \left(\alpha + \beta\right) - \left(2 \cdot 1\right) \cdot \left(2 \cdot 1\right)} \cdot \left(\left(\alpha + \beta\right) - 2 \cdot 1\right)}}{\left(\left(\left(\alpha + \beta\right) + 2 \cdot 1\right) + 1\right) \cdot \left(\left(\alpha + \beta\right) + 2 \cdot 1\right)} \]
      8. times-fracN/A

        \[\leadsto \color{blue}{\frac{\frac{\left(\left(\alpha + \beta\right) + \beta \cdot \alpha\right) + 1}{\left(\alpha + \beta\right) \cdot \left(\alpha + \beta\right) - \left(2 \cdot 1\right) \cdot \left(2 \cdot 1\right)}}{\left(\left(\alpha + \beta\right) + 2 \cdot 1\right) + 1} \cdot \frac{\left(\alpha + \beta\right) - 2 \cdot 1}{\left(\alpha + \beta\right) + 2 \cdot 1}} \]
    4. Applied rewrites99.9%

      \[\leadsto \color{blue}{\frac{\frac{\mathsf{fma}\left(\alpha, \beta, \alpha + \beta\right) + 1}{\mathsf{fma}\left(\alpha + \beta, \alpha + \beta, -4\right)}}{\alpha + \left(\beta + 3\right)} \cdot \frac{\left(\alpha + \beta\right) + -2}{\left(\alpha + \beta\right) + 2}} \]

    if 2.9e9 < beta

    1. Initial program 89.7%

      \[\frac{\frac{\frac{\left(\left(\alpha + \beta\right) + \beta \cdot \alpha\right) + 1}{\left(\alpha + \beta\right) + 2 \cdot 1}}{\left(\alpha + \beta\right) + 2 \cdot 1}}{\left(\left(\alpha + \beta\right) + 2 \cdot 1\right) + 1} \]
    2. Add Preprocessing
    3. Taylor expanded in beta around inf

      \[\leadsto \frac{\color{blue}{\frac{\left(1 + \left(\alpha + \left(\frac{1}{\beta} + \frac{\alpha}{\beta}\right)\right)\right) - \frac{\left(1 + \alpha\right) \cdot \left(4 + 2 \cdot \alpha\right)}{\beta}}{\beta}}}{\left(\left(\alpha + \beta\right) + 2 \cdot 1\right) + 1} \]
    4. Step-by-step derivation
      1. lower-/.f64N/A

        \[\leadsto \frac{\color{blue}{\frac{\left(1 + \left(\alpha + \left(\frac{1}{\beta} + \frac{\alpha}{\beta}\right)\right)\right) - \frac{\left(1 + \alpha\right) \cdot \left(4 + 2 \cdot \alpha\right)}{\beta}}{\beta}}}{\left(\left(\alpha + \beta\right) + 2 \cdot 1\right) + 1} \]
    5. Applied rewrites99.3%

      \[\leadsto \frac{\color{blue}{\frac{\left(\left(1 + \alpha\right) + \left(\frac{1}{\beta} + \frac{\alpha}{\beta}\right)\right) + \left(-1 - \alpha\right) \cdot \frac{\mathsf{fma}\left(2, \alpha, 4\right)}{\beta}}{\beta}}}{\left(\left(\alpha + \beta\right) + 2 \cdot 1\right) + 1} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification99.6%

    \[\leadsto \begin{array}{l} \mathbf{if}\;\beta \leq 2900000000:\\ \;\;\;\;\frac{\frac{\mathsf{fma}\left(\alpha, \beta, \beta + \alpha\right) + 1}{\mathsf{fma}\left(\beta + \alpha, \beta + \alpha, -4\right)}}{\alpha + \left(\beta + 3\right)} \cdot \frac{\left(\beta + \alpha\right) + -2}{\left(\beta + \alpha\right) + 2}\\ \mathbf{else}:\\ \;\;\;\;\frac{\frac{\left(\left(\frac{1}{\beta} + \frac{\alpha}{\beta}\right) + \left(\alpha + 1\right)\right) + \left(-1 - \alpha\right) \cdot \frac{\mathsf{fma}\left(2, \alpha, 4\right)}{\beta}}{\beta}}{\left(\left(\beta + \alpha\right) + 2\right) + 1}\\ \end{array} \]
  5. Add Preprocessing

Reproduce

?
herbie shell --seed 2024230 
(FPCore (alpha beta)
  :name "Octave 3.8, jcobi/3"
  :precision binary64
  :pre (and (> alpha -1.0) (> beta -1.0))
  (/ (/ (/ (+ (+ (+ alpha beta) (* beta alpha)) 1.0) (+ (+ alpha beta) (* 2.0 1.0))) (+ (+ alpha beta) (* 2.0 1.0))) (+ (+ (+ alpha beta) (* 2.0 1.0)) 1.0)))