Falkner and Boettcher, Equation (22+)

Percentage Accurate: 98.5% → 100.0%
Time: 2.9s
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, 0.9× speedup?

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

\\
\frac{4}{\sqrt{\mathsf{fma}\left(-6, v \cdot v, 2\right)} \cdot 3} \cdot \frac{1}{\left(1 - v \cdot v\right) \cdot \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. metadata-evalN/A

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

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

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

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

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

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

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

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

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

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

Alternative 2: 100.0% accurate, 1.2× speedup?

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

\\
\frac{-1.3333333333333333}{\mathsf{fma}\left(v, v, -1\right) \cdot \left(\sqrt{\mathsf{fma}\left(-6, v \cdot v, 2\right)} \cdot \pi\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. metadata-evalN/A

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

      \[\leadsto \frac{\frac{-4}{3}}{\mathsf{fma}\left(v, v, -1\right) \cdot \left(\color{blue}{\sqrt{\mathsf{fma}\left(v \cdot v, -6, 2\right)}} \cdot \pi\right)} \]
    11. pow1/2N/A

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

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

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

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

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

      \[\leadsto \frac{\frac{-4}{3}}{\mathsf{fma}\left(v, v, -1\right) \cdot \left({\color{blue}{\left(\mathsf{fma}\left(-6, v \cdot v, 2\right)\right)}}^{\frac{1}{2}} \cdot \pi\right)} \]
    17. pow1/2N/A

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

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

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

Alternative 3: 100.0% accurate, 1.2× speedup?

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

\\
\frac{-1.3333333333333333}{\left(\mathsf{fma}\left(v, v, -1\right) \cdot \sqrt{\mathsf{fma}\left(v \cdot v, -6, 2\right)}\right) \cdot \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. metadata-evalN/A

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

      \[\leadsto \frac{\frac{4}{3}}{\color{blue}{\sqrt{\mathsf{fma}\left(-6, v \cdot v, 2\right)}} \cdot \pi} \]
    5. pow1/2N/A

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

      \[\leadsto \frac{\frac{4}{3}}{{\color{blue}{\left(-6 \cdot \left(v \cdot v\right) + 2\right)}}^{\frac{1}{2}} \cdot \pi} \]
    7. add-flipN/A

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

      \[\leadsto \frac{\frac{4}{3}}{{\left(\color{blue}{\left(v \cdot v\right) \cdot -6} - \left(\mathsf{neg}\left(2\right)\right)\right)}^{\frac{1}{2}} \cdot \pi} \]
    9. add-flipN/A

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

      \[\leadsto \frac{\frac{4}{3}}{{\color{blue}{\left(\mathsf{fma}\left(v \cdot v, -6, 2\right)\right)}}^{\frac{1}{2}} \cdot \pi} \]
    11. pow1/2N/A

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

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

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

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

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

Alternative 5: 99.0% accurate, 1.7× speedup?

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

\\
\frac{1.3333333333333333}{\pi \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. mult-flipN/A

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Alternative 6: 98.9% 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.f6498.9

      \[\leadsto \frac{1.3333333333333333}{\pi \cdot \sqrt{2}} \]
  4. Applied rewrites98.9%

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

Reproduce

?
herbie shell --seed 2025153 
(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)))))))