Falkner and Boettcher, Equation (22+)

Percentage Accurate: 98.5% → 100.0%
Time: 1.8s
Alternatives: 6
Speedup: 3.2×

Specification

?
\[\begin{array}{l} \\ \frac{4}{\left(\left(3 \cdot \pi\right) \cdot \left(1 - v \cdot v\right)\right) \cdot \sqrt{2 - 6 \cdot \left(v \cdot v\right)}} \end{array} \]
(FPCore (v)
 :precision binary64
 (/ 4.0 (* (* (* 3.0 PI) (- 1.0 (* v v))) (sqrt (- 2.0 (* 6.0 (* v v)))))))
double code(double v) {
	return 4.0 / (((3.0 * ((double) M_PI)) * (1.0 - (v * v))) * sqrt((2.0 - (6.0 * (v * v)))));
}
public static double code(double v) {
	return 4.0 / (((3.0 * Math.PI) * (1.0 - (v * v))) * Math.sqrt((2.0 - (6.0 * (v * v)))));
}
def code(v):
	return 4.0 / (((3.0 * math.pi) * (1.0 - (v * v))) * math.sqrt((2.0 - (6.0 * (v * v)))))
function code(v)
	return Float64(4.0 / Float64(Float64(Float64(3.0 * pi) * Float64(1.0 - Float64(v * v))) * sqrt(Float64(2.0 - Float64(6.0 * Float64(v * v))))))
end
function tmp = code(v)
	tmp = 4.0 / (((3.0 * pi) * (1.0 - (v * v))) * sqrt((2.0 - (6.0 * (v * v)))));
end
code[v_] := N[(4.0 / N[(N[(N[(3.0 * Pi), $MachinePrecision] * N[(1.0 - N[(v * v), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * N[Sqrt[N[(2.0 - N[(6.0 * N[(v * v), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{4}{\left(\left(3 \cdot \pi\right) \cdot \left(1 - v \cdot v\right)\right) \cdot \sqrt{2 - 6 \cdot \left(v \cdot v\right)}}
\end{array}

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: 98.5% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \frac{4}{\left(\left(3 \cdot \pi\right) \cdot \left(1 - v \cdot v\right)\right) \cdot \sqrt{2 - 6 \cdot \left(v \cdot v\right)}} \end{array} \]
(FPCore (v)
 :precision binary64
 (/ 4.0 (* (* (* 3.0 PI) (- 1.0 (* v v))) (sqrt (- 2.0 (* 6.0 (* v v)))))))
double code(double v) {
	return 4.0 / (((3.0 * ((double) M_PI)) * (1.0 - (v * v))) * sqrt((2.0 - (6.0 * (v * v)))));
}
public static double code(double v) {
	return 4.0 / (((3.0 * Math.PI) * (1.0 - (v * v))) * Math.sqrt((2.0 - (6.0 * (v * v)))));
}
def code(v):
	return 4.0 / (((3.0 * math.pi) * (1.0 - (v * v))) * math.sqrt((2.0 - (6.0 * (v * v)))))
function code(v)
	return Float64(4.0 / Float64(Float64(Float64(3.0 * pi) * Float64(1.0 - Float64(v * v))) * sqrt(Float64(2.0 - Float64(6.0 * Float64(v * v))))))
end
function tmp = code(v)
	tmp = 4.0 / (((3.0 * pi) * (1.0 - (v * v))) * sqrt((2.0 - (6.0 * (v * v)))));
end
code[v_] := N[(4.0 / N[(N[(N[(3.0 * Pi), $MachinePrecision] * N[(1.0 - N[(v * v), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * N[Sqrt[N[(2.0 - N[(6.0 * N[(v * v), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{4}{\left(\left(3 \cdot \pi\right) \cdot \left(1 - v \cdot v\right)\right) \cdot \sqrt{2 - 6 \cdot \left(v \cdot v\right)}}
\end{array}

Alternative 1: 100.0% accurate, 1.2× speedup?

\[\begin{array}{l} \\ \frac{-1.3333333333333333}{\left(\mathsf{fma}\left(v, v, -1\right) \cdot \pi\right) \cdot \sqrt{\mathsf{fma}\left(-6, v \cdot v, 2\right)}} \end{array} \]
(FPCore (v)
 :precision binary64
 (/
  -1.3333333333333333
  (* (* (fma v v -1.0) PI) (sqrt (fma -6.0 (* v v) 2.0)))))
double code(double v) {
	return -1.3333333333333333 / ((fma(v, v, -1.0) * ((double) M_PI)) * sqrt(fma(-6.0, (v * v), 2.0)));
}
function code(v)
	return Float64(-1.3333333333333333 / Float64(Float64(fma(v, v, -1.0) * pi) * sqrt(fma(-6.0, Float64(v * v), 2.0))))
end
code[v_] := N[(-1.3333333333333333 / N[(N[(N[(v * v + -1.0), $MachinePrecision] * Pi), $MachinePrecision] * N[Sqrt[N[(-6.0 * N[(v * v), $MachinePrecision] + 2.0), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{-1.3333333333333333}{\left(\mathsf{fma}\left(v, v, -1\right) \cdot \pi\right) \cdot \sqrt{\mathsf{fma}\left(-6, v \cdot v, 2\right)}}
\end{array}
Derivation
  1. Initial program 98.5%

    \[\frac{4}{\left(\left(3 \cdot \pi\right) \cdot \left(1 - v \cdot v\right)\right) \cdot \sqrt{2 - 6 \cdot \left(v \cdot v\right)}} \]
  2. Step-by-step derivation
    1. lift-/.f64N/A

      \[\leadsto \color{blue}{\frac{4}{\left(\left(3 \cdot \pi\right) \cdot \left(1 - v \cdot v\right)\right) \cdot \sqrt{2 - 6 \cdot \left(v \cdot v\right)}}} \]
    2. lift-*.f64N/A

      \[\leadsto \frac{4}{\color{blue}{\left(\left(3 \cdot \pi\right) \cdot \left(1 - v \cdot v\right)\right) \cdot \sqrt{2 - 6 \cdot \left(v \cdot v\right)}}} \]
    3. associate-/r*N/A

      \[\leadsto \color{blue}{\frac{\frac{4}{\left(3 \cdot \pi\right) \cdot \left(1 - v \cdot v\right)}}{\sqrt{2 - 6 \cdot \left(v \cdot v\right)}}} \]
    4. lower-/.f64N/A

      \[\leadsto \color{blue}{\frac{\frac{4}{\left(3 \cdot \pi\right) \cdot \left(1 - v \cdot v\right)}}{\sqrt{2 - 6 \cdot \left(v \cdot v\right)}}} \]
    5. lift-*.f64N/A

      \[\leadsto \frac{\frac{4}{\color{blue}{\left(3 \cdot \pi\right) \cdot \left(1 - v \cdot v\right)}}}{\sqrt{2 - 6 \cdot \left(v \cdot v\right)}} \]
    6. lift-*.f64N/A

      \[\leadsto \frac{\frac{4}{\color{blue}{\left(3 \cdot \pi\right)} \cdot \left(1 - v \cdot v\right)}}{\sqrt{2 - 6 \cdot \left(v \cdot v\right)}} \]
    7. associate-*l*N/A

      \[\leadsto \frac{\frac{4}{\color{blue}{3 \cdot \left(\pi \cdot \left(1 - v \cdot v\right)\right)}}}{\sqrt{2 - 6 \cdot \left(v \cdot v\right)}} \]
    8. associate-/r*N/A

      \[\leadsto \frac{\color{blue}{\frac{\frac{4}{3}}{\pi \cdot \left(1 - v \cdot v\right)}}}{\sqrt{2 - 6 \cdot \left(v \cdot v\right)}} \]
    9. lower-/.f64N/A

      \[\leadsto \frac{\color{blue}{\frac{\frac{4}{3}}{\pi \cdot \left(1 - v \cdot v\right)}}}{\sqrt{2 - 6 \cdot \left(v \cdot v\right)}} \]
    10. metadata-evalN/A

      \[\leadsto \frac{\frac{\color{blue}{\frac{4}{3}}}{\pi \cdot \left(1 - v \cdot v\right)}}{\sqrt{2 - 6 \cdot \left(v \cdot v\right)}} \]
    11. *-commutativeN/A

      \[\leadsto \frac{\frac{\frac{4}{3}}{\color{blue}{\left(1 - v \cdot v\right) \cdot \pi}}}{\sqrt{2 - 6 \cdot \left(v \cdot v\right)}} \]
    12. lower-*.f64100.0

      \[\leadsto \frac{\frac{1.3333333333333333}{\color{blue}{\left(1 - v \cdot v\right) \cdot \pi}}}{\sqrt{2 - 6 \cdot \left(v \cdot v\right)}} \]
    13. lift--.f64N/A

      \[\leadsto \frac{\frac{\frac{4}{3}}{\left(1 - v \cdot v\right) \cdot \pi}}{\sqrt{\color{blue}{2 - 6 \cdot \left(v \cdot v\right)}}} \]
    14. sub-flipN/A

      \[\leadsto \frac{\frac{\frac{4}{3}}{\left(1 - v \cdot v\right) \cdot \pi}}{\sqrt{\color{blue}{2 + \left(\mathsf{neg}\left(6 \cdot \left(v \cdot v\right)\right)\right)}}} \]
    15. +-commutativeN/A

      \[\leadsto \frac{\frac{\frac{4}{3}}{\left(1 - v \cdot v\right) \cdot \pi}}{\sqrt{\color{blue}{\left(\mathsf{neg}\left(6 \cdot \left(v \cdot v\right)\right)\right) + 2}}} \]
    16. lift-*.f64N/A

      \[\leadsto \frac{\frac{\frac{4}{3}}{\left(1 - v \cdot v\right) \cdot \pi}}{\sqrt{\left(\mathsf{neg}\left(\color{blue}{6 \cdot \left(v \cdot v\right)}\right)\right) + 2}} \]
    17. distribute-lft-neg-outN/A

      \[\leadsto \frac{\frac{\frac{4}{3}}{\left(1 - v \cdot v\right) \cdot \pi}}{\sqrt{\color{blue}{\left(\mathsf{neg}\left(6\right)\right) \cdot \left(v \cdot v\right)} + 2}} \]
  3. Applied rewrites100.0%

    \[\leadsto \color{blue}{\frac{\frac{1.3333333333333333}{\left(1 - v \cdot v\right) \cdot \pi}}{\sqrt{\mathsf{fma}\left(-6, v \cdot v, 2\right)}}} \]
  4. Step-by-step derivation
    1. lift-/.f64N/A

      \[\leadsto \color{blue}{\frac{\frac{\frac{4}{3}}{\left(1 - v \cdot v\right) \cdot \pi}}{\sqrt{\mathsf{fma}\left(-6, v \cdot v, 2\right)}}} \]
    2. lift-/.f64N/A

      \[\leadsto \frac{\color{blue}{\frac{\frac{4}{3}}{\left(1 - v \cdot v\right) \cdot \pi}}}{\sqrt{\mathsf{fma}\left(-6, v \cdot v, 2\right)}} \]
    3. frac-2negN/A

      \[\leadsto \frac{\color{blue}{\frac{\mathsf{neg}\left(\frac{4}{3}\right)}{\mathsf{neg}\left(\left(1 - v \cdot v\right) \cdot \pi\right)}}}{\sqrt{\mathsf{fma}\left(-6, v \cdot v, 2\right)}} \]
    4. associate-/l/N/A

      \[\leadsto \color{blue}{\frac{\mathsf{neg}\left(\frac{4}{3}\right)}{\left(\mathsf{neg}\left(\left(1 - v \cdot v\right) \cdot \pi\right)\right) \cdot \sqrt{\mathsf{fma}\left(-6, v \cdot v, 2\right)}}} \]
    5. lower-/.f64N/A

      \[\leadsto \color{blue}{\frac{\mathsf{neg}\left(\frac{4}{3}\right)}{\left(\mathsf{neg}\left(\left(1 - v \cdot v\right) \cdot \pi\right)\right) \cdot \sqrt{\mathsf{fma}\left(-6, v \cdot v, 2\right)}}} \]
    6. metadata-evalN/A

      \[\leadsto \frac{\color{blue}{\frac{-4}{3}}}{\left(\mathsf{neg}\left(\left(1 - v \cdot v\right) \cdot \pi\right)\right) \cdot \sqrt{\mathsf{fma}\left(-6, v \cdot v, 2\right)}} \]
    7. lower-*.f64N/A

      \[\leadsto \frac{\frac{-4}{3}}{\color{blue}{\left(\mathsf{neg}\left(\left(1 - v \cdot v\right) \cdot \pi\right)\right) \cdot \sqrt{\mathsf{fma}\left(-6, v \cdot v, 2\right)}}} \]
    8. lift-*.f64N/A

      \[\leadsto \frac{\frac{-4}{3}}{\left(\mathsf{neg}\left(\color{blue}{\left(1 - v \cdot v\right) \cdot \pi}\right)\right) \cdot \sqrt{\mathsf{fma}\left(-6, v \cdot v, 2\right)}} \]
    9. distribute-lft-neg-inN/A

      \[\leadsto \frac{\frac{-4}{3}}{\color{blue}{\left(\left(\mathsf{neg}\left(\left(1 - v \cdot v\right)\right)\right) \cdot \pi\right)} \cdot \sqrt{\mathsf{fma}\left(-6, v \cdot v, 2\right)}} \]
    10. lift--.f64N/A

      \[\leadsto \frac{\frac{-4}{3}}{\left(\left(\mathsf{neg}\left(\color{blue}{\left(1 - v \cdot v\right)}\right)\right) \cdot \pi\right) \cdot \sqrt{\mathsf{fma}\left(-6, v \cdot v, 2\right)}} \]
    11. sub-negate-revN/A

      \[\leadsto \frac{\frac{-4}{3}}{\left(\color{blue}{\left(v \cdot v - 1\right)} \cdot \pi\right) \cdot \sqrt{\mathsf{fma}\left(-6, v \cdot v, 2\right)}} \]
    12. lower-*.f64N/A

      \[\leadsto \frac{\frac{-4}{3}}{\color{blue}{\left(\left(v \cdot v - 1\right) \cdot \pi\right)} \cdot \sqrt{\mathsf{fma}\left(-6, v \cdot v, 2\right)}} \]
    13. sub-flipN/A

      \[\leadsto \frac{\frac{-4}{3}}{\left(\color{blue}{\left(v \cdot v + \left(\mathsf{neg}\left(1\right)\right)\right)} \cdot \pi\right) \cdot \sqrt{\mathsf{fma}\left(-6, v \cdot v, 2\right)}} \]
    14. lift-*.f64N/A

      \[\leadsto \frac{\frac{-4}{3}}{\left(\left(\color{blue}{v \cdot v} + \left(\mathsf{neg}\left(1\right)\right)\right) \cdot \pi\right) \cdot \sqrt{\mathsf{fma}\left(-6, v \cdot v, 2\right)}} \]
    15. metadata-evalN/A

      \[\leadsto \frac{\frac{-4}{3}}{\left(\left(v \cdot v + \color{blue}{-1}\right) \cdot \pi\right) \cdot \sqrt{\mathsf{fma}\left(-6, v \cdot v, 2\right)}} \]
    16. lower-fma.f64100.0

      \[\leadsto \frac{-1.3333333333333333}{\left(\color{blue}{\mathsf{fma}\left(v, v, -1\right)} \cdot \pi\right) \cdot \sqrt{\mathsf{fma}\left(-6, v \cdot v, 2\right)}} \]
  5. Applied rewrites100.0%

    \[\leadsto \color{blue}{\frac{-1.3333333333333333}{\left(\mathsf{fma}\left(v, v, -1\right) \cdot \pi\right) \cdot \sqrt{\mathsf{fma}\left(-6, v \cdot v, 2\right)}}} \]
  6. Add Preprocessing

Alternative 2: 99.0% accurate, 1.4× speedup?

\[\begin{array}{l} \\ \frac{\frac{4}{3 \cdot \pi}}{\sqrt{\mathsf{fma}\left(-6, v \cdot v, 2\right)}} \end{array} \]
(FPCore (v)
 :precision binary64
 (/ (/ 4.0 (* 3.0 PI)) (sqrt (fma -6.0 (* v v) 2.0))))
double code(double v) {
	return (4.0 / (3.0 * ((double) M_PI))) / sqrt(fma(-6.0, (v * v), 2.0));
}
function code(v)
	return Float64(Float64(4.0 / Float64(3.0 * pi)) / sqrt(fma(-6.0, Float64(v * v), 2.0)))
end
code[v_] := N[(N[(4.0 / N[(3.0 * Pi), $MachinePrecision]), $MachinePrecision] / N[Sqrt[N[(-6.0 * N[(v * v), $MachinePrecision] + 2.0), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{\frac{4}{3 \cdot \pi}}{\sqrt{\mathsf{fma}\left(-6, v \cdot v, 2\right)}}
\end{array}
Derivation
  1. Initial program 98.5%

    \[\frac{4}{\left(\left(3 \cdot \pi\right) \cdot \left(1 - v \cdot v\right)\right) \cdot \sqrt{2 - 6 \cdot \left(v \cdot v\right)}} \]
  2. Taylor expanded in v around 0

    \[\leadsto \frac{4}{\color{blue}{\left(3 \cdot \mathsf{PI}\left(\right)\right)} \cdot \sqrt{2 - 6 \cdot \left(v \cdot v\right)}} \]
  3. Step-by-step derivation
    1. lower-*.f64N/A

      \[\leadsto \frac{4}{\left(3 \cdot \color{blue}{\mathsf{PI}\left(\right)}\right) \cdot \sqrt{2 - 6 \cdot \left(v \cdot v\right)}} \]
    2. lower-PI.f6497.5

      \[\leadsto \frac{4}{\left(3 \cdot \pi\right) \cdot \sqrt{2 - 6 \cdot \left(v \cdot v\right)}} \]
  4. Applied rewrites97.5%

    \[\leadsto \frac{4}{\color{blue}{\left(3 \cdot \pi\right)} \cdot \sqrt{2 - 6 \cdot \left(v \cdot v\right)}} \]
  5. Step-by-step derivation
    1. lift-/.f64N/A

      \[\leadsto \color{blue}{\frac{4}{\left(3 \cdot \pi\right) \cdot \sqrt{2 - 6 \cdot \left(v \cdot v\right)}}} \]
    2. lift-*.f64N/A

      \[\leadsto \frac{4}{\color{blue}{\left(3 \cdot \pi\right) \cdot \sqrt{2 - 6 \cdot \left(v \cdot v\right)}}} \]
    3. associate-/r*N/A

      \[\leadsto \color{blue}{\frac{\frac{4}{3 \cdot \pi}}{\sqrt{2 - 6 \cdot \left(v \cdot v\right)}}} \]
    4. lift--.f64N/A

      \[\leadsto \frac{\frac{4}{3 \cdot \pi}}{\sqrt{\color{blue}{2 - 6 \cdot \left(v \cdot v\right)}}} \]
    5. lift-*.f64N/A

      \[\leadsto \frac{\frac{4}{3 \cdot \pi}}{\sqrt{2 - \color{blue}{6 \cdot \left(v \cdot v\right)}}} \]
    6. fp-cancel-sub-sign-invN/A

      \[\leadsto \frac{\frac{4}{3 \cdot \pi}}{\sqrt{\color{blue}{2 + \left(\mathsf{neg}\left(6\right)\right) \cdot \left(v \cdot v\right)}}} \]
    7. metadata-evalN/A

      \[\leadsto \frac{\frac{4}{3 \cdot \pi}}{\sqrt{2 + \color{blue}{-6} \cdot \left(v \cdot v\right)}} \]
    8. +-commutativeN/A

      \[\leadsto \frac{\frac{4}{3 \cdot \pi}}{\sqrt{\color{blue}{-6 \cdot \left(v \cdot v\right) + 2}}} \]
    9. lift-fma.f64N/A

      \[\leadsto \frac{\frac{4}{3 \cdot \pi}}{\sqrt{\color{blue}{\mathsf{fma}\left(-6, v \cdot v, 2\right)}}} \]
    10. lower-/.f64N/A

      \[\leadsto \color{blue}{\frac{\frac{4}{3 \cdot \pi}}{\sqrt{\mathsf{fma}\left(-6, v \cdot v, 2\right)}}} \]
    11. lower-/.f6499.0

      \[\leadsto \frac{\color{blue}{\frac{4}{3 \cdot \pi}}}{\sqrt{\mathsf{fma}\left(-6, v \cdot v, 2\right)}} \]
  6. Applied rewrites99.0%

    \[\leadsto \color{blue}{\frac{\frac{4}{3 \cdot \pi}}{\sqrt{\mathsf{fma}\left(-6, v \cdot v, 2\right)}}} \]
  7. Add Preprocessing

Alternative 3: 99.0% accurate, 1.5× speedup?

\[\begin{array}{l} \\ \frac{1}{\sqrt{\mathsf{fma}\left(-6, v \cdot v, 2\right)} \cdot \pi} \cdot 1.3333333333333333 \end{array} \]
(FPCore (v)
 :precision binary64
 (* (/ 1.0 (* (sqrt (fma -6.0 (* v v) 2.0)) PI)) 1.3333333333333333))
double code(double v) {
	return (1.0 / (sqrt(fma(-6.0, (v * v), 2.0)) * ((double) M_PI))) * 1.3333333333333333;
}
function code(v)
	return Float64(Float64(1.0 / Float64(sqrt(fma(-6.0, Float64(v * v), 2.0)) * pi)) * 1.3333333333333333)
end
code[v_] := N[(N[(1.0 / N[(N[Sqrt[N[(-6.0 * N[(v * v), $MachinePrecision] + 2.0), $MachinePrecision]], $MachinePrecision] * Pi), $MachinePrecision]), $MachinePrecision] * 1.3333333333333333), $MachinePrecision]
\begin{array}{l}

\\
\frac{1}{\sqrt{\mathsf{fma}\left(-6, v \cdot v, 2\right)} \cdot \pi} \cdot 1.3333333333333333
\end{array}
Derivation
  1. Initial program 98.5%

    \[\frac{4}{\left(\left(3 \cdot \pi\right) \cdot \left(1 - v \cdot v\right)\right) \cdot \sqrt{2 - 6 \cdot \left(v \cdot v\right)}} \]
  2. Step-by-step derivation
    1. lift-/.f64N/A

      \[\leadsto \color{blue}{\frac{4}{\left(\left(3 \cdot \pi\right) \cdot \left(1 - v \cdot v\right)\right) \cdot \sqrt{2 - 6 \cdot \left(v \cdot v\right)}}} \]
    2. lift-*.f64N/A

      \[\leadsto \frac{4}{\color{blue}{\left(\left(3 \cdot \pi\right) \cdot \left(1 - v \cdot v\right)\right) \cdot \sqrt{2 - 6 \cdot \left(v \cdot v\right)}}} \]
    3. associate-/r*N/A

      \[\leadsto \color{blue}{\frac{\frac{4}{\left(3 \cdot \pi\right) \cdot \left(1 - v \cdot v\right)}}{\sqrt{2 - 6 \cdot \left(v \cdot v\right)}}} \]
    4. lower-/.f64N/A

      \[\leadsto \color{blue}{\frac{\frac{4}{\left(3 \cdot \pi\right) \cdot \left(1 - v \cdot v\right)}}{\sqrt{2 - 6 \cdot \left(v \cdot v\right)}}} \]
    5. lift-*.f64N/A

      \[\leadsto \frac{\frac{4}{\color{blue}{\left(3 \cdot \pi\right) \cdot \left(1 - v \cdot v\right)}}}{\sqrt{2 - 6 \cdot \left(v \cdot v\right)}} \]
    6. lift-*.f64N/A

      \[\leadsto \frac{\frac{4}{\color{blue}{\left(3 \cdot \pi\right)} \cdot \left(1 - v \cdot v\right)}}{\sqrt{2 - 6 \cdot \left(v \cdot v\right)}} \]
    7. associate-*l*N/A

      \[\leadsto \frac{\frac{4}{\color{blue}{3 \cdot \left(\pi \cdot \left(1 - v \cdot v\right)\right)}}}{\sqrt{2 - 6 \cdot \left(v \cdot v\right)}} \]
    8. associate-/r*N/A

      \[\leadsto \frac{\color{blue}{\frac{\frac{4}{3}}{\pi \cdot \left(1 - v \cdot v\right)}}}{\sqrt{2 - 6 \cdot \left(v \cdot v\right)}} \]
    9. lower-/.f64N/A

      \[\leadsto \frac{\color{blue}{\frac{\frac{4}{3}}{\pi \cdot \left(1 - v \cdot v\right)}}}{\sqrt{2 - 6 \cdot \left(v \cdot v\right)}} \]
    10. metadata-evalN/A

      \[\leadsto \frac{\frac{\color{blue}{\frac{4}{3}}}{\pi \cdot \left(1 - v \cdot v\right)}}{\sqrt{2 - 6 \cdot \left(v \cdot v\right)}} \]
    11. *-commutativeN/A

      \[\leadsto \frac{\frac{\frac{4}{3}}{\color{blue}{\left(1 - v \cdot v\right) \cdot \pi}}}{\sqrt{2 - 6 \cdot \left(v \cdot v\right)}} \]
    12. lower-*.f64100.0

      \[\leadsto \frac{\frac{1.3333333333333333}{\color{blue}{\left(1 - v \cdot v\right) \cdot \pi}}}{\sqrt{2 - 6 \cdot \left(v \cdot v\right)}} \]
    13. lift--.f64N/A

      \[\leadsto \frac{\frac{\frac{4}{3}}{\left(1 - v \cdot v\right) \cdot \pi}}{\sqrt{\color{blue}{2 - 6 \cdot \left(v \cdot v\right)}}} \]
    14. sub-flipN/A

      \[\leadsto \frac{\frac{\frac{4}{3}}{\left(1 - v \cdot v\right) \cdot \pi}}{\sqrt{\color{blue}{2 + \left(\mathsf{neg}\left(6 \cdot \left(v \cdot v\right)\right)\right)}}} \]
    15. +-commutativeN/A

      \[\leadsto \frac{\frac{\frac{4}{3}}{\left(1 - v \cdot v\right) \cdot \pi}}{\sqrt{\color{blue}{\left(\mathsf{neg}\left(6 \cdot \left(v \cdot v\right)\right)\right) + 2}}} \]
    16. lift-*.f64N/A

      \[\leadsto \frac{\frac{\frac{4}{3}}{\left(1 - v \cdot v\right) \cdot \pi}}{\sqrt{\left(\mathsf{neg}\left(\color{blue}{6 \cdot \left(v \cdot v\right)}\right)\right) + 2}} \]
    17. distribute-lft-neg-outN/A

      \[\leadsto \frac{\frac{\frac{4}{3}}{\left(1 - v \cdot v\right) \cdot \pi}}{\sqrt{\color{blue}{\left(\mathsf{neg}\left(6\right)\right) \cdot \left(v \cdot v\right)} + 2}} \]
  3. Applied rewrites100.0%

    \[\leadsto \color{blue}{\frac{\frac{1.3333333333333333}{\left(1 - v \cdot v\right) \cdot \pi}}{\sqrt{\mathsf{fma}\left(-6, v \cdot v, 2\right)}}} \]
  4. Taylor expanded in v around 0

    \[\leadsto \frac{\frac{\frac{4}{3}}{\color{blue}{\mathsf{PI}\left(\right)}}}{\sqrt{\mathsf{fma}\left(-6, v \cdot v, 2\right)}} \]
  5. Step-by-step derivation
    1. lower-PI.f6499.0

      \[\leadsto \frac{\frac{1.3333333333333333}{\pi}}{\sqrt{\mathsf{fma}\left(-6, v \cdot v, 2\right)}} \]
  6. Applied rewrites99.0%

    \[\leadsto \frac{\frac{1.3333333333333333}{\color{blue}{\pi}}}{\sqrt{\mathsf{fma}\left(-6, v \cdot v, 2\right)}} \]
  7. Step-by-step derivation
    1. lift-/.f64N/A

      \[\leadsto \color{blue}{\frac{\frac{\frac{4}{3}}{\pi}}{\sqrt{\mathsf{fma}\left(-6, v \cdot v, 2\right)}}} \]
    2. lift-/.f64N/A

      \[\leadsto \frac{\color{blue}{\frac{\frac{4}{3}}{\pi}}}{\sqrt{\mathsf{fma}\left(-6, v \cdot v, 2\right)}} \]
    3. associate-/l/N/A

      \[\leadsto \color{blue}{\frac{\frac{4}{3}}{\pi \cdot \sqrt{\mathsf{fma}\left(-6, v \cdot v, 2\right)}}} \]
    4. mult-flipN/A

      \[\leadsto \color{blue}{\frac{4}{3} \cdot \frac{1}{\pi \cdot \sqrt{\mathsf{fma}\left(-6, v \cdot v, 2\right)}}} \]
    5. lower-*.f64N/A

      \[\leadsto \color{blue}{\frac{4}{3} \cdot \frac{1}{\pi \cdot \sqrt{\mathsf{fma}\left(-6, v \cdot v, 2\right)}}} \]
    6. lower-/.f64N/A

      \[\leadsto \frac{4}{3} \cdot \color{blue}{\frac{1}{\pi \cdot \sqrt{\mathsf{fma}\left(-6, v \cdot v, 2\right)}}} \]
    7. lower-*.f6499.0

      \[\leadsto 1.3333333333333333 \cdot \frac{1}{\color{blue}{\pi \cdot \sqrt{\mathsf{fma}\left(-6, v \cdot v, 2\right)}}} \]
    8. lift-fma.f64N/A

      \[\leadsto \frac{4}{3} \cdot \frac{1}{\pi \cdot \sqrt{\color{blue}{-6 \cdot \left(v \cdot v\right) + 2}}} \]
    9. *-commutativeN/A

      \[\leadsto \frac{4}{3} \cdot \frac{1}{\pi \cdot \sqrt{\color{blue}{\left(v \cdot v\right) \cdot -6} + 2}} \]
    10. lower-fma.f6499.0

      \[\leadsto 1.3333333333333333 \cdot \frac{1}{\pi \cdot \sqrt{\color{blue}{\mathsf{fma}\left(v \cdot v, -6, 2\right)}}} \]
  8. Applied rewrites99.0%

    \[\leadsto \color{blue}{1.3333333333333333 \cdot \frac{1}{\pi \cdot \sqrt{\mathsf{fma}\left(v \cdot v, -6, 2\right)}}} \]
  9. Step-by-step derivation
    1. lift-*.f64N/A

      \[\leadsto \color{blue}{\frac{4}{3} \cdot \frac{1}{\pi \cdot \sqrt{\mathsf{fma}\left(v \cdot v, -6, 2\right)}}} \]
    2. *-commutativeN/A

      \[\leadsto \color{blue}{\frac{1}{\pi \cdot \sqrt{\mathsf{fma}\left(v \cdot v, -6, 2\right)}} \cdot \frac{4}{3}} \]
    3. lower-*.f6499.0

      \[\leadsto \color{blue}{\frac{1}{\pi \cdot \sqrt{\mathsf{fma}\left(v \cdot v, -6, 2\right)}} \cdot 1.3333333333333333} \]
    4. lift-*.f64N/A

      \[\leadsto \frac{1}{\color{blue}{\pi \cdot \sqrt{\mathsf{fma}\left(v \cdot v, -6, 2\right)}}} \cdot \frac{4}{3} \]
    5. *-commutativeN/A

      \[\leadsto \frac{1}{\color{blue}{\sqrt{\mathsf{fma}\left(v \cdot v, -6, 2\right)} \cdot \pi}} \cdot \frac{4}{3} \]
    6. lower-*.f6499.0

      \[\leadsto \frac{1}{\color{blue}{\sqrt{\mathsf{fma}\left(v \cdot v, -6, 2\right)} \cdot \pi}} \cdot 1.3333333333333333 \]
    7. lift-fma.f64N/A

      \[\leadsto \frac{1}{\sqrt{\color{blue}{\left(v \cdot v\right) \cdot -6 + 2}} \cdot \pi} \cdot \frac{4}{3} \]
    8. *-commutativeN/A

      \[\leadsto \frac{1}{\sqrt{\color{blue}{-6 \cdot \left(v \cdot v\right)} + 2} \cdot \pi} \cdot \frac{4}{3} \]
    9. lower-fma.f6499.0

      \[\leadsto \frac{1}{\sqrt{\color{blue}{\mathsf{fma}\left(-6, v \cdot v, 2\right)}} \cdot \pi} \cdot 1.3333333333333333 \]
  10. Applied rewrites99.0%

    \[\leadsto \color{blue}{\frac{1}{\sqrt{\mathsf{fma}\left(-6, v \cdot v, 2\right)} \cdot \pi} \cdot 1.3333333333333333} \]
  11. Add Preprocessing

Alternative 4: 99.0% accurate, 1.7× speedup?

\[\begin{array}{l} \\ \frac{\frac{1.3333333333333333}{\sqrt{\mathsf{fma}\left(-6, v \cdot v, 2\right)}}}{\pi} \end{array} \]
(FPCore (v)
 :precision binary64
 (/ (/ 1.3333333333333333 (sqrt (fma -6.0 (* v v) 2.0))) PI))
double code(double v) {
	return (1.3333333333333333 / sqrt(fma(-6.0, (v * v), 2.0))) / ((double) M_PI);
}
function code(v)
	return Float64(Float64(1.3333333333333333 / sqrt(fma(-6.0, Float64(v * v), 2.0))) / pi)
end
code[v_] := N[(N[(1.3333333333333333 / N[Sqrt[N[(-6.0 * N[(v * v), $MachinePrecision] + 2.0), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] / Pi), $MachinePrecision]
\begin{array}{l}

\\
\frac{\frac{1.3333333333333333}{\sqrt{\mathsf{fma}\left(-6, v \cdot v, 2\right)}}}{\pi}
\end{array}
Derivation
  1. Initial program 98.5%

    \[\frac{4}{\left(\left(3 \cdot \pi\right) \cdot \left(1 - v \cdot v\right)\right) \cdot \sqrt{2 - 6 \cdot \left(v \cdot v\right)}} \]
  2. Step-by-step derivation
    1. lift-/.f64N/A

      \[\leadsto \color{blue}{\frac{4}{\left(\left(3 \cdot \pi\right) \cdot \left(1 - v \cdot v\right)\right) \cdot \sqrt{2 - 6 \cdot \left(v \cdot v\right)}}} \]
    2. lift-*.f64N/A

      \[\leadsto \frac{4}{\color{blue}{\left(\left(3 \cdot \pi\right) \cdot \left(1 - v \cdot v\right)\right) \cdot \sqrt{2 - 6 \cdot \left(v \cdot v\right)}}} \]
    3. associate-/r*N/A

      \[\leadsto \color{blue}{\frac{\frac{4}{\left(3 \cdot \pi\right) \cdot \left(1 - v \cdot v\right)}}{\sqrt{2 - 6 \cdot \left(v \cdot v\right)}}} \]
    4. lower-/.f64N/A

      \[\leadsto \color{blue}{\frac{\frac{4}{\left(3 \cdot \pi\right) \cdot \left(1 - v \cdot v\right)}}{\sqrt{2 - 6 \cdot \left(v \cdot v\right)}}} \]
    5. lift-*.f64N/A

      \[\leadsto \frac{\frac{4}{\color{blue}{\left(3 \cdot \pi\right) \cdot \left(1 - v \cdot v\right)}}}{\sqrt{2 - 6 \cdot \left(v \cdot v\right)}} \]
    6. lift-*.f64N/A

      \[\leadsto \frac{\frac{4}{\color{blue}{\left(3 \cdot \pi\right)} \cdot \left(1 - v \cdot v\right)}}{\sqrt{2 - 6 \cdot \left(v \cdot v\right)}} \]
    7. associate-*l*N/A

      \[\leadsto \frac{\frac{4}{\color{blue}{3 \cdot \left(\pi \cdot \left(1 - v \cdot v\right)\right)}}}{\sqrt{2 - 6 \cdot \left(v \cdot v\right)}} \]
    8. associate-/r*N/A

      \[\leadsto \frac{\color{blue}{\frac{\frac{4}{3}}{\pi \cdot \left(1 - v \cdot v\right)}}}{\sqrt{2 - 6 \cdot \left(v \cdot v\right)}} \]
    9. lower-/.f64N/A

      \[\leadsto \frac{\color{blue}{\frac{\frac{4}{3}}{\pi \cdot \left(1 - v \cdot v\right)}}}{\sqrt{2 - 6 \cdot \left(v \cdot v\right)}} \]
    10. metadata-evalN/A

      \[\leadsto \frac{\frac{\color{blue}{\frac{4}{3}}}{\pi \cdot \left(1 - v \cdot v\right)}}{\sqrt{2 - 6 \cdot \left(v \cdot v\right)}} \]
    11. *-commutativeN/A

      \[\leadsto \frac{\frac{\frac{4}{3}}{\color{blue}{\left(1 - v \cdot v\right) \cdot \pi}}}{\sqrt{2 - 6 \cdot \left(v \cdot v\right)}} \]
    12. lower-*.f64100.0

      \[\leadsto \frac{\frac{1.3333333333333333}{\color{blue}{\left(1 - v \cdot v\right) \cdot \pi}}}{\sqrt{2 - 6 \cdot \left(v \cdot v\right)}} \]
    13. lift--.f64N/A

      \[\leadsto \frac{\frac{\frac{4}{3}}{\left(1 - v \cdot v\right) \cdot \pi}}{\sqrt{\color{blue}{2 - 6 \cdot \left(v \cdot v\right)}}} \]
    14. sub-flipN/A

      \[\leadsto \frac{\frac{\frac{4}{3}}{\left(1 - v \cdot v\right) \cdot \pi}}{\sqrt{\color{blue}{2 + \left(\mathsf{neg}\left(6 \cdot \left(v \cdot v\right)\right)\right)}}} \]
    15. +-commutativeN/A

      \[\leadsto \frac{\frac{\frac{4}{3}}{\left(1 - v \cdot v\right) \cdot \pi}}{\sqrt{\color{blue}{\left(\mathsf{neg}\left(6 \cdot \left(v \cdot v\right)\right)\right) + 2}}} \]
    16. lift-*.f64N/A

      \[\leadsto \frac{\frac{\frac{4}{3}}{\left(1 - v \cdot v\right) \cdot \pi}}{\sqrt{\left(\mathsf{neg}\left(\color{blue}{6 \cdot \left(v \cdot v\right)}\right)\right) + 2}} \]
    17. distribute-lft-neg-outN/A

      \[\leadsto \frac{\frac{\frac{4}{3}}{\left(1 - v \cdot v\right) \cdot \pi}}{\sqrt{\color{blue}{\left(\mathsf{neg}\left(6\right)\right) \cdot \left(v \cdot v\right)} + 2}} \]
  3. Applied rewrites100.0%

    \[\leadsto \color{blue}{\frac{\frac{1.3333333333333333}{\left(1 - v \cdot v\right) \cdot \pi}}{\sqrt{\mathsf{fma}\left(-6, v \cdot v, 2\right)}}} \]
  4. Taylor expanded in v around 0

    \[\leadsto \frac{\frac{\frac{4}{3}}{\color{blue}{\mathsf{PI}\left(\right)}}}{\sqrt{\mathsf{fma}\left(-6, v \cdot v, 2\right)}} \]
  5. Step-by-step derivation
    1. lower-PI.f6499.0

      \[\leadsto \frac{\frac{1.3333333333333333}{\pi}}{\sqrt{\mathsf{fma}\left(-6, v \cdot v, 2\right)}} \]
  6. Applied rewrites99.0%

    \[\leadsto \frac{\frac{1.3333333333333333}{\color{blue}{\pi}}}{\sqrt{\mathsf{fma}\left(-6, v \cdot v, 2\right)}} \]
  7. Step-by-step derivation
    1. lift-/.f64N/A

      \[\leadsto \color{blue}{\frac{\frac{\frac{4}{3}}{\pi}}{\sqrt{\mathsf{fma}\left(-6, v \cdot v, 2\right)}}} \]
    2. lift-/.f64N/A

      \[\leadsto \frac{\color{blue}{\frac{\frac{4}{3}}{\pi}}}{\sqrt{\mathsf{fma}\left(-6, v \cdot v, 2\right)}} \]
    3. associate-/l/N/A

      \[\leadsto \color{blue}{\frac{\frac{4}{3}}{\pi \cdot \sqrt{\mathsf{fma}\left(-6, v \cdot v, 2\right)}}} \]
    4. mult-flipN/A

      \[\leadsto \color{blue}{\frac{4}{3} \cdot \frac{1}{\pi \cdot \sqrt{\mathsf{fma}\left(-6, v \cdot v, 2\right)}}} \]
    5. lower-*.f64N/A

      \[\leadsto \color{blue}{\frac{4}{3} \cdot \frac{1}{\pi \cdot \sqrt{\mathsf{fma}\left(-6, v \cdot v, 2\right)}}} \]
    6. lower-/.f64N/A

      \[\leadsto \frac{4}{3} \cdot \color{blue}{\frac{1}{\pi \cdot \sqrt{\mathsf{fma}\left(-6, v \cdot v, 2\right)}}} \]
    7. lower-*.f6499.0

      \[\leadsto 1.3333333333333333 \cdot \frac{1}{\color{blue}{\pi \cdot \sqrt{\mathsf{fma}\left(-6, v \cdot v, 2\right)}}} \]
    8. lift-fma.f64N/A

      \[\leadsto \frac{4}{3} \cdot \frac{1}{\pi \cdot \sqrt{\color{blue}{-6 \cdot \left(v \cdot v\right) + 2}}} \]
    9. *-commutativeN/A

      \[\leadsto \frac{4}{3} \cdot \frac{1}{\pi \cdot \sqrt{\color{blue}{\left(v \cdot v\right) \cdot -6} + 2}} \]
    10. lower-fma.f6499.0

      \[\leadsto 1.3333333333333333 \cdot \frac{1}{\pi \cdot \sqrt{\color{blue}{\mathsf{fma}\left(v \cdot v, -6, 2\right)}}} \]
  8. Applied rewrites99.0%

    \[\leadsto \color{blue}{1.3333333333333333 \cdot \frac{1}{\pi \cdot \sqrt{\mathsf{fma}\left(v \cdot v, -6, 2\right)}}} \]
  9. Step-by-step derivation
    1. lift-*.f64N/A

      \[\leadsto \color{blue}{\frac{4}{3} \cdot \frac{1}{\pi \cdot \sqrt{\mathsf{fma}\left(v \cdot v, -6, 2\right)}}} \]
    2. lift-/.f64N/A

      \[\leadsto \frac{4}{3} \cdot \color{blue}{\frac{1}{\pi \cdot \sqrt{\mathsf{fma}\left(v \cdot v, -6, 2\right)}}} \]
    3. mult-flip-revN/A

      \[\leadsto \color{blue}{\frac{\frac{4}{3}}{\pi \cdot \sqrt{\mathsf{fma}\left(v \cdot v, -6, 2\right)}}} \]
    4. lift-*.f64N/A

      \[\leadsto \frac{\frac{4}{3}}{\color{blue}{\pi \cdot \sqrt{\mathsf{fma}\left(v \cdot v, -6, 2\right)}}} \]
    5. *-commutativeN/A

      \[\leadsto \frac{\frac{4}{3}}{\color{blue}{\sqrt{\mathsf{fma}\left(v \cdot v, -6, 2\right)} \cdot \pi}} \]
    6. associate-/r*N/A

      \[\leadsto \color{blue}{\frac{\frac{\frac{4}{3}}{\sqrt{\mathsf{fma}\left(v \cdot v, -6, 2\right)}}}{\pi}} \]
    7. lower-/.f64N/A

      \[\leadsto \color{blue}{\frac{\frac{\frac{4}{3}}{\sqrt{\mathsf{fma}\left(v \cdot v, -6, 2\right)}}}{\pi}} \]
    8. lower-/.f6499.0

      \[\leadsto \frac{\color{blue}{\frac{1.3333333333333333}{\sqrt{\mathsf{fma}\left(v \cdot v, -6, 2\right)}}}}{\pi} \]
    9. lift-fma.f64N/A

      \[\leadsto \frac{\frac{\frac{4}{3}}{\sqrt{\color{blue}{\left(v \cdot v\right) \cdot -6 + 2}}}}{\pi} \]
    10. *-commutativeN/A

      \[\leadsto \frac{\frac{\frac{4}{3}}{\sqrt{\color{blue}{-6 \cdot \left(v \cdot v\right)} + 2}}}{\pi} \]
    11. lower-fma.f6499.0

      \[\leadsto \frac{\frac{1.3333333333333333}{\sqrt{\color{blue}{\mathsf{fma}\left(-6, v \cdot v, 2\right)}}}}{\pi} \]
  10. Applied rewrites99.0%

    \[\leadsto \color{blue}{\frac{\frac{1.3333333333333333}{\sqrt{\mathsf{fma}\left(-6, v \cdot v, 2\right)}}}{\pi}} \]
  11. Add Preprocessing

Alternative 5: 99.0% accurate, 1.7× speedup?

\[\begin{array}{l} \\ \frac{1.3333333333333333}{\pi \cdot \sqrt{\mathsf{fma}\left(v \cdot v, -6, 2\right)}} \end{array} \]
(FPCore (v)
 :precision binary64
 (/ 1.3333333333333333 (* PI (sqrt (fma (* v v) -6.0 2.0)))))
double code(double v) {
	return 1.3333333333333333 / (((double) M_PI) * sqrt(fma((v * v), -6.0, 2.0)));
}
function code(v)
	return Float64(1.3333333333333333 / Float64(pi * sqrt(fma(Float64(v * v), -6.0, 2.0))))
end
code[v_] := N[(1.3333333333333333 / N[(Pi * N[Sqrt[N[(N[(v * v), $MachinePrecision] * -6.0 + 2.0), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{1.3333333333333333}{\pi \cdot \sqrt{\mathsf{fma}\left(v \cdot v, -6, 2\right)}}
\end{array}
Derivation
  1. Initial program 98.5%

    \[\frac{4}{\left(\left(3 \cdot \pi\right) \cdot \left(1 - v \cdot v\right)\right) \cdot \sqrt{2 - 6 \cdot \left(v \cdot v\right)}} \]
  2. Step-by-step derivation
    1. lift-/.f64N/A

      \[\leadsto \color{blue}{\frac{4}{\left(\left(3 \cdot \pi\right) \cdot \left(1 - v \cdot v\right)\right) \cdot \sqrt{2 - 6 \cdot \left(v \cdot v\right)}}} \]
    2. lift-*.f64N/A

      \[\leadsto \frac{4}{\color{blue}{\left(\left(3 \cdot \pi\right) \cdot \left(1 - v \cdot v\right)\right) \cdot \sqrt{2 - 6 \cdot \left(v \cdot v\right)}}} \]
    3. associate-/r*N/A

      \[\leadsto \color{blue}{\frac{\frac{4}{\left(3 \cdot \pi\right) \cdot \left(1 - v \cdot v\right)}}{\sqrt{2 - 6 \cdot \left(v \cdot v\right)}}} \]
    4. lower-/.f64N/A

      \[\leadsto \color{blue}{\frac{\frac{4}{\left(3 \cdot \pi\right) \cdot \left(1 - v \cdot v\right)}}{\sqrt{2 - 6 \cdot \left(v \cdot v\right)}}} \]
    5. lift-*.f64N/A

      \[\leadsto \frac{\frac{4}{\color{blue}{\left(3 \cdot \pi\right) \cdot \left(1 - v \cdot v\right)}}}{\sqrt{2 - 6 \cdot \left(v \cdot v\right)}} \]
    6. lift-*.f64N/A

      \[\leadsto \frac{\frac{4}{\color{blue}{\left(3 \cdot \pi\right)} \cdot \left(1 - v \cdot v\right)}}{\sqrt{2 - 6 \cdot \left(v \cdot v\right)}} \]
    7. associate-*l*N/A

      \[\leadsto \frac{\frac{4}{\color{blue}{3 \cdot \left(\pi \cdot \left(1 - v \cdot v\right)\right)}}}{\sqrt{2 - 6 \cdot \left(v \cdot v\right)}} \]
    8. associate-/r*N/A

      \[\leadsto \frac{\color{blue}{\frac{\frac{4}{3}}{\pi \cdot \left(1 - v \cdot v\right)}}}{\sqrt{2 - 6 \cdot \left(v \cdot v\right)}} \]
    9. lower-/.f64N/A

      \[\leadsto \frac{\color{blue}{\frac{\frac{4}{3}}{\pi \cdot \left(1 - v \cdot v\right)}}}{\sqrt{2 - 6 \cdot \left(v \cdot v\right)}} \]
    10. metadata-evalN/A

      \[\leadsto \frac{\frac{\color{blue}{\frac{4}{3}}}{\pi \cdot \left(1 - v \cdot v\right)}}{\sqrt{2 - 6 \cdot \left(v \cdot v\right)}} \]
    11. *-commutativeN/A

      \[\leadsto \frac{\frac{\frac{4}{3}}{\color{blue}{\left(1 - v \cdot v\right) \cdot \pi}}}{\sqrt{2 - 6 \cdot \left(v \cdot v\right)}} \]
    12. lower-*.f64100.0

      \[\leadsto \frac{\frac{1.3333333333333333}{\color{blue}{\left(1 - v \cdot v\right) \cdot \pi}}}{\sqrt{2 - 6 \cdot \left(v \cdot v\right)}} \]
    13. lift--.f64N/A

      \[\leadsto \frac{\frac{\frac{4}{3}}{\left(1 - v \cdot v\right) \cdot \pi}}{\sqrt{\color{blue}{2 - 6 \cdot \left(v \cdot v\right)}}} \]
    14. sub-flipN/A

      \[\leadsto \frac{\frac{\frac{4}{3}}{\left(1 - v \cdot v\right) \cdot \pi}}{\sqrt{\color{blue}{2 + \left(\mathsf{neg}\left(6 \cdot \left(v \cdot v\right)\right)\right)}}} \]
    15. +-commutativeN/A

      \[\leadsto \frac{\frac{\frac{4}{3}}{\left(1 - v \cdot v\right) \cdot \pi}}{\sqrt{\color{blue}{\left(\mathsf{neg}\left(6 \cdot \left(v \cdot v\right)\right)\right) + 2}}} \]
    16. lift-*.f64N/A

      \[\leadsto \frac{\frac{\frac{4}{3}}{\left(1 - v \cdot v\right) \cdot \pi}}{\sqrt{\left(\mathsf{neg}\left(\color{blue}{6 \cdot \left(v \cdot v\right)}\right)\right) + 2}} \]
    17. distribute-lft-neg-outN/A

      \[\leadsto \frac{\frac{\frac{4}{3}}{\left(1 - v \cdot v\right) \cdot \pi}}{\sqrt{\color{blue}{\left(\mathsf{neg}\left(6\right)\right) \cdot \left(v \cdot v\right)} + 2}} \]
  3. Applied rewrites100.0%

    \[\leadsto \color{blue}{\frac{\frac{1.3333333333333333}{\left(1 - v \cdot v\right) \cdot \pi}}{\sqrt{\mathsf{fma}\left(-6, v \cdot v, 2\right)}}} \]
  4. Taylor expanded in v around 0

    \[\leadsto \frac{\frac{\frac{4}{3}}{\color{blue}{\mathsf{PI}\left(\right)}}}{\sqrt{\mathsf{fma}\left(-6, v \cdot v, 2\right)}} \]
  5. Step-by-step derivation
    1. lower-PI.f6499.0

      \[\leadsto \frac{\frac{1.3333333333333333}{\pi}}{\sqrt{\mathsf{fma}\left(-6, v \cdot v, 2\right)}} \]
  6. Applied rewrites99.0%

    \[\leadsto \frac{\frac{1.3333333333333333}{\color{blue}{\pi}}}{\sqrt{\mathsf{fma}\left(-6, v \cdot v, 2\right)}} \]
  7. Step-by-step derivation
    1. lift-/.f64N/A

      \[\leadsto \color{blue}{\frac{\frac{\frac{4}{3}}{\pi}}{\sqrt{\mathsf{fma}\left(-6, v \cdot v, 2\right)}}} \]
    2. lift-/.f64N/A

      \[\leadsto \frac{\color{blue}{\frac{\frac{4}{3}}{\pi}}}{\sqrt{\mathsf{fma}\left(-6, v \cdot v, 2\right)}} \]
    3. associate-/l/N/A

      \[\leadsto \color{blue}{\frac{\frac{4}{3}}{\pi \cdot \sqrt{\mathsf{fma}\left(-6, v \cdot v, 2\right)}}} \]
    4. lower-/.f64N/A

      \[\leadsto \color{blue}{\frac{\frac{4}{3}}{\pi \cdot \sqrt{\mathsf{fma}\left(-6, v \cdot v, 2\right)}}} \]
    5. lower-*.f6499.0

      \[\leadsto \frac{1.3333333333333333}{\color{blue}{\pi \cdot \sqrt{\mathsf{fma}\left(-6, v \cdot v, 2\right)}}} \]
    6. lift-fma.f64N/A

      \[\leadsto \frac{\frac{4}{3}}{\pi \cdot \sqrt{\color{blue}{-6 \cdot \left(v \cdot v\right) + 2}}} \]
    7. *-commutativeN/A

      \[\leadsto \frac{\frac{4}{3}}{\pi \cdot \sqrt{\color{blue}{\left(v \cdot v\right) \cdot -6} + 2}} \]
    8. lower-fma.f6499.0

      \[\leadsto \frac{1.3333333333333333}{\pi \cdot \sqrt{\color{blue}{\mathsf{fma}\left(v \cdot v, -6, 2\right)}}} \]
  8. Applied rewrites99.0%

    \[\leadsto \color{blue}{\frac{1.3333333333333333}{\pi \cdot \sqrt{\mathsf{fma}\left(v \cdot v, -6, 2\right)}}} \]
  9. Add Preprocessing

Alternative 6: 99.0% accurate, 3.2× speedup?

\[\begin{array}{l} \\ \frac{1.3333333333333333}{\pi \cdot \sqrt{2}} \end{array} \]
(FPCore (v) :precision binary64 (/ 1.3333333333333333 (* PI (sqrt 2.0))))
double code(double v) {
	return 1.3333333333333333 / (((double) M_PI) * sqrt(2.0));
}
public static double code(double v) {
	return 1.3333333333333333 / (Math.PI * Math.sqrt(2.0));
}
def code(v):
	return 1.3333333333333333 / (math.pi * math.sqrt(2.0))
function code(v)
	return Float64(1.3333333333333333 / Float64(pi * sqrt(2.0)))
end
function tmp = code(v)
	tmp = 1.3333333333333333 / (pi * sqrt(2.0));
end
code[v_] := N[(1.3333333333333333 / N[(Pi * N[Sqrt[2.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{1.3333333333333333}{\pi \cdot \sqrt{2}}
\end{array}
Derivation
  1. Initial program 98.5%

    \[\frac{4}{\left(\left(3 \cdot \pi\right) \cdot \left(1 - v \cdot v\right)\right) \cdot \sqrt{2 - 6 \cdot \left(v \cdot v\right)}} \]
  2. Taylor expanded in v around 0

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

      \[\leadsto \frac{\frac{4}{3}}{\color{blue}{\mathsf{PI}\left(\right) \cdot \sqrt{2}}} \]
    2. lower-*.f64N/A

      \[\leadsto \frac{\frac{4}{3}}{\mathsf{PI}\left(\right) \cdot \color{blue}{\sqrt{2}}} \]
    3. lower-PI.f64N/A

      \[\leadsto \frac{\frac{4}{3}}{\pi \cdot \sqrt{\color{blue}{2}}} \]
    4. lower-sqrt.f6499.0

      \[\leadsto \frac{1.3333333333333333}{\pi \cdot \sqrt{2}} \]
  4. Applied rewrites99.0%

    \[\leadsto \color{blue}{\frac{1.3333333333333333}{\pi \cdot \sqrt{2}}} \]
  5. Add Preprocessing

Reproduce

?
herbie shell --seed 2025151 
(FPCore (v)
  :name "Falkner and Boettcher, Equation (22+)"
  :precision binary64
  (/ 4.0 (* (* (* 3.0 PI) (- 1.0 (* v v))) (sqrt (- 2.0 (* 6.0 (* v v)))))))