Falkner and Boettcher, Appendix B, 2

Percentage Accurate: 100.0% → 100.0%
Time: 11.2s
Alternatives: 3
Speedup: 1.9×

Specification

?
\[\begin{array}{l} \\ \left(\frac{\sqrt{2}}{4} \cdot \sqrt{1 - 3 \cdot \left(v \cdot v\right)}\right) \cdot \left(1 - v \cdot v\right) \end{array} \]
(FPCore (v)
 :precision binary64
 (* (* (/ (sqrt 2.0) 4.0) (sqrt (- 1.0 (* 3.0 (* v v))))) (- 1.0 (* v v))))
double code(double v) {
	return ((sqrt(2.0) / 4.0) * sqrt((1.0 - (3.0 * (v * v))))) * (1.0 - (v * v));
}
real(8) function code(v)
    real(8), intent (in) :: v
    code = ((sqrt(2.0d0) / 4.0d0) * sqrt((1.0d0 - (3.0d0 * (v * v))))) * (1.0d0 - (v * v))
end function
public static double code(double v) {
	return ((Math.sqrt(2.0) / 4.0) * Math.sqrt((1.0 - (3.0 * (v * v))))) * (1.0 - (v * v));
}
def code(v):
	return ((math.sqrt(2.0) / 4.0) * math.sqrt((1.0 - (3.0 * (v * v))))) * (1.0 - (v * v))
function code(v)
	return Float64(Float64(Float64(sqrt(2.0) / 4.0) * sqrt(Float64(1.0 - Float64(3.0 * Float64(v * v))))) * Float64(1.0 - Float64(v * v)))
end
function tmp = code(v)
	tmp = ((sqrt(2.0) / 4.0) * sqrt((1.0 - (3.0 * (v * v))))) * (1.0 - (v * v));
end
code[v_] := N[(N[(N[(N[Sqrt[2.0], $MachinePrecision] / 4.0), $MachinePrecision] * N[Sqrt[N[(1.0 - N[(3.0 * N[(v * v), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] * N[(1.0 - N[(v * v), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\left(\frac{\sqrt{2}}{4} \cdot \sqrt{1 - 3 \cdot \left(v \cdot v\right)}\right) \cdot \left(1 - v \cdot v\right)
\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 3 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: 100.0% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \left(\frac{\sqrt{2}}{4} \cdot \sqrt{1 - 3 \cdot \left(v \cdot v\right)}\right) \cdot \left(1 - v \cdot v\right) \end{array} \]
(FPCore (v)
 :precision binary64
 (* (* (/ (sqrt 2.0) 4.0) (sqrt (- 1.0 (* 3.0 (* v v))))) (- 1.0 (* v v))))
double code(double v) {
	return ((sqrt(2.0) / 4.0) * sqrt((1.0 - (3.0 * (v * v))))) * (1.0 - (v * v));
}
real(8) function code(v)
    real(8), intent (in) :: v
    code = ((sqrt(2.0d0) / 4.0d0) * sqrt((1.0d0 - (3.0d0 * (v * v))))) * (1.0d0 - (v * v))
end function
public static double code(double v) {
	return ((Math.sqrt(2.0) / 4.0) * Math.sqrt((1.0 - (3.0 * (v * v))))) * (1.0 - (v * v));
}
def code(v):
	return ((math.sqrt(2.0) / 4.0) * math.sqrt((1.0 - (3.0 * (v * v))))) * (1.0 - (v * v))
function code(v)
	return Float64(Float64(Float64(sqrt(2.0) / 4.0) * sqrt(Float64(1.0 - Float64(3.0 * Float64(v * v))))) * Float64(1.0 - Float64(v * v)))
end
function tmp = code(v)
	tmp = ((sqrt(2.0) / 4.0) * sqrt((1.0 - (3.0 * (v * v))))) * (1.0 - (v * v));
end
code[v_] := N[(N[(N[(N[Sqrt[2.0], $MachinePrecision] / 4.0), $MachinePrecision] * N[Sqrt[N[(1.0 - N[(3.0 * N[(v * v), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] * N[(1.0 - N[(v * v), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

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

Alternative 1: 100.0% accurate, 1.9× speedup?

\[\begin{array}{l} \\ \frac{\sqrt{2 + 2 \cdot \left(\left(v \cdot v\right) \cdot -3\right)}}{4} \cdot \left(1 - v \cdot v\right) \end{array} \]
(FPCore (v)
 :precision binary64
 (* (/ (sqrt (+ 2.0 (* 2.0 (* (* v v) -3.0)))) 4.0) (- 1.0 (* v v))))
double code(double v) {
	return (sqrt((2.0 + (2.0 * ((v * v) * -3.0)))) / 4.0) * (1.0 - (v * v));
}
real(8) function code(v)
    real(8), intent (in) :: v
    code = (sqrt((2.0d0 + (2.0d0 * ((v * v) * (-3.0d0))))) / 4.0d0) * (1.0d0 - (v * v))
end function
public static double code(double v) {
	return (Math.sqrt((2.0 + (2.0 * ((v * v) * -3.0)))) / 4.0) * (1.0 - (v * v));
}
def code(v):
	return (math.sqrt((2.0 + (2.0 * ((v * v) * -3.0)))) / 4.0) * (1.0 - (v * v))
function code(v)
	return Float64(Float64(sqrt(Float64(2.0 + Float64(2.0 * Float64(Float64(v * v) * -3.0)))) / 4.0) * Float64(1.0 - Float64(v * v)))
end
function tmp = code(v)
	tmp = (sqrt((2.0 + (2.0 * ((v * v) * -3.0)))) / 4.0) * (1.0 - (v * v));
end
code[v_] := N[(N[(N[Sqrt[N[(2.0 + N[(2.0 * N[(N[(v * v), $MachinePrecision] * -3.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] / 4.0), $MachinePrecision] * N[(1.0 - N[(v * v), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{\sqrt{2 + 2 \cdot \left(\left(v \cdot v\right) \cdot -3\right)}}{4} \cdot \left(1 - v \cdot v\right)
\end{array}
Derivation
  1. Initial program 100.0%

    \[\left(\frac{\sqrt{2}}{4} \cdot \sqrt{1 - 3 \cdot \left(v \cdot v\right)}\right) \cdot \left(1 - v \cdot v\right) \]
  2. Add Preprocessing
  3. Step-by-step derivation
    1. add-sqr-sqrt100.0%

      \[\leadsto \left(\frac{\sqrt{2}}{4} \cdot \sqrt{1 - \color{blue}{\sqrt{3 \cdot \left(v \cdot v\right)} \cdot \sqrt{3 \cdot \left(v \cdot v\right)}}}\right) \cdot \left(1 - v \cdot v\right) \]
    2. sqrt-unprod100.0%

      \[\leadsto \left(\frac{\sqrt{2}}{4} \cdot \sqrt{1 - \color{blue}{\sqrt{\left(3 \cdot \left(v \cdot v\right)\right) \cdot \left(3 \cdot \left(v \cdot v\right)\right)}}}\right) \cdot \left(1 - v \cdot v\right) \]
    3. swap-sqr100.0%

      \[\leadsto \left(\frac{\sqrt{2}}{4} \cdot \sqrt{1 - \sqrt{\color{blue}{\left(3 \cdot 3\right) \cdot \left(\left(v \cdot v\right) \cdot \left(v \cdot v\right)\right)}}}\right) \cdot \left(1 - v \cdot v\right) \]
    4. metadata-eval100.0%

      \[\leadsto \left(\frac{\sqrt{2}}{4} \cdot \sqrt{1 - \sqrt{\color{blue}{9} \cdot \left(\left(v \cdot v\right) \cdot \left(v \cdot v\right)\right)}}\right) \cdot \left(1 - v \cdot v\right) \]
    5. metadata-eval100.0%

      \[\leadsto \left(\frac{\sqrt{2}}{4} \cdot \sqrt{1 - \sqrt{\color{blue}{\left(-3 \cdot -3\right)} \cdot \left(\left(v \cdot v\right) \cdot \left(v \cdot v\right)\right)}}\right) \cdot \left(1 - v \cdot v\right) \]
    6. swap-sqr100.0%

      \[\leadsto \left(\frac{\sqrt{2}}{4} \cdot \sqrt{1 - \sqrt{\color{blue}{\left(-3 \cdot \left(v \cdot v\right)\right) \cdot \left(-3 \cdot \left(v \cdot v\right)\right)}}}\right) \cdot \left(1 - v \cdot v\right) \]
    7. sqrt-unprod43.4%

      \[\leadsto \left(\frac{\sqrt{2}}{4} \cdot \sqrt{1 - \color{blue}{\sqrt{-3 \cdot \left(v \cdot v\right)} \cdot \sqrt{-3 \cdot \left(v \cdot v\right)}}}\right) \cdot \left(1 - v \cdot v\right) \]
    8. add-sqr-sqrt97.2%

      \[\leadsto \left(\frac{\sqrt{2}}{4} \cdot \sqrt{1 - \color{blue}{-3 \cdot \left(v \cdot v\right)}}\right) \cdot \left(1 - v \cdot v\right) \]
    9. metadata-eval97.2%

      \[\leadsto \left(\frac{\sqrt{2}}{4} \cdot \sqrt{1 - \color{blue}{\left(-3\right)} \cdot \left(v \cdot v\right)}\right) \cdot \left(1 - v \cdot v\right) \]
    10. distribute-lft-neg-in97.2%

      \[\leadsto \left(\frac{\sqrt{2}}{4} \cdot \sqrt{1 - \color{blue}{\left(-3 \cdot \left(v \cdot v\right)\right)}}\right) \cdot \left(1 - v \cdot v\right) \]
    11. add-log-exp97.2%

      \[\leadsto \left(\frac{\sqrt{2}}{4} \cdot \sqrt{1 - \left(-\color{blue}{\log \left(e^{3 \cdot \left(v \cdot v\right)}\right)}\right)}\right) \cdot \left(1 - v \cdot v\right) \]
    12. neg-log97.2%

      \[\leadsto \left(\frac{\sqrt{2}}{4} \cdot \sqrt{1 - \color{blue}{\log \left(\frac{1}{e^{3 \cdot \left(v \cdot v\right)}}\right)}}\right) \cdot \left(1 - v \cdot v\right) \]
    13. add-sqr-sqrt97.2%

      \[\leadsto \left(\frac{\sqrt{2}}{4} \cdot \sqrt{1 - \log \left(\frac{1}{e^{\color{blue}{\sqrt{3 \cdot \left(v \cdot v\right)} \cdot \sqrt{3 \cdot \left(v \cdot v\right)}}}}\right)}\right) \cdot \left(1 - v \cdot v\right) \]
    14. sqrt-unprod97.2%

      \[\leadsto \left(\frac{\sqrt{2}}{4} \cdot \sqrt{1 - \log \left(\frac{1}{e^{\color{blue}{\sqrt{\left(3 \cdot \left(v \cdot v\right)\right) \cdot \left(3 \cdot \left(v \cdot v\right)\right)}}}}\right)}\right) \cdot \left(1 - v \cdot v\right) \]
    15. swap-sqr97.2%

      \[\leadsto \left(\frac{\sqrt{2}}{4} \cdot \sqrt{1 - \log \left(\frac{1}{e^{\sqrt{\color{blue}{\left(3 \cdot 3\right) \cdot \left(\left(v \cdot v\right) \cdot \left(v \cdot v\right)\right)}}}}\right)}\right) \cdot \left(1 - v \cdot v\right) \]
    16. metadata-eval97.2%

      \[\leadsto \left(\frac{\sqrt{2}}{4} \cdot \sqrt{1 - \log \left(\frac{1}{e^{\sqrt{\color{blue}{9} \cdot \left(\left(v \cdot v\right) \cdot \left(v \cdot v\right)\right)}}}\right)}\right) \cdot \left(1 - v \cdot v\right) \]
    17. metadata-eval97.2%

      \[\leadsto \left(\frac{\sqrt{2}}{4} \cdot \sqrt{1 - \log \left(\frac{1}{e^{\sqrt{\color{blue}{\left(-3 \cdot -3\right)} \cdot \left(\left(v \cdot v\right) \cdot \left(v \cdot v\right)\right)}}}\right)}\right) \cdot \left(1 - v \cdot v\right) \]
    18. swap-sqr97.2%

      \[\leadsto \left(\frac{\sqrt{2}}{4} \cdot \sqrt{1 - \log \left(\frac{1}{e^{\sqrt{\color{blue}{\left(-3 \cdot \left(v \cdot v\right)\right) \cdot \left(-3 \cdot \left(v \cdot v\right)\right)}}}}\right)}\right) \cdot \left(1 - v \cdot v\right) \]
    19. sqrt-unprod43.4%

      \[\leadsto \left(\frac{\sqrt{2}}{4} \cdot \sqrt{1 - \log \left(\frac{1}{e^{\color{blue}{\sqrt{-3 \cdot \left(v \cdot v\right)} \cdot \sqrt{-3 \cdot \left(v \cdot v\right)}}}}\right)}\right) \cdot \left(1 - v \cdot v\right) \]
    20. add-sqr-sqrt100.0%

      \[\leadsto \left(\frac{\sqrt{2}}{4} \cdot \sqrt{1 - \log \left(\frac{1}{e^{\color{blue}{-3 \cdot \left(v \cdot v\right)}}}\right)}\right) \cdot \left(1 - v \cdot v\right) \]
    21. exp-prod100.0%

      \[\leadsto \left(\frac{\sqrt{2}}{4} \cdot \sqrt{1 - \log \left(\frac{1}{\color{blue}{{\left(e^{-3}\right)}^{\left(v \cdot v\right)}}}\right)}\right) \cdot \left(1 - v \cdot v\right) \]
    22. pow2100.0%

      \[\leadsto \left(\frac{\sqrt{2}}{4} \cdot \sqrt{1 - \log \left(\frac{1}{{\left(e^{-3}\right)}^{\color{blue}{\left({v}^{2}\right)}}}\right)}\right) \cdot \left(1 - v \cdot v\right) \]
  4. Applied egg-rr100.0%

    \[\leadsto \left(\frac{\sqrt{2}}{4} \cdot \sqrt{1 - \color{blue}{\log \left(\frac{1}{{\left(e^{-3}\right)}^{\left({v}^{2}\right)}}\right)}}\right) \cdot \left(1 - v \cdot v\right) \]
  5. Step-by-step derivation
    1. associate-*l/100.0%

      \[\leadsto \color{blue}{\frac{\sqrt{2} \cdot \sqrt{1 - \log \left(\frac{1}{{\left(e^{-3}\right)}^{\left({v}^{2}\right)}}\right)}}{4}} \cdot \left(1 - v \cdot v\right) \]
    2. pow1/2100.0%

      \[\leadsto \frac{\color{blue}{{2}^{0.5}} \cdot \sqrt{1 - \log \left(\frac{1}{{\left(e^{-3}\right)}^{\left({v}^{2}\right)}}\right)}}{4} \cdot \left(1 - v \cdot v\right) \]
    3. pow1/2100.0%

      \[\leadsto \frac{{2}^{0.5} \cdot \color{blue}{{\left(1 - \log \left(\frac{1}{{\left(e^{-3}\right)}^{\left({v}^{2}\right)}}\right)\right)}^{0.5}}}{4} \cdot \left(1 - v \cdot v\right) \]
    4. pow-prod-down100.0%

      \[\leadsto \frac{\color{blue}{{\left(2 \cdot \left(1 - \log \left(\frac{1}{{\left(e^{-3}\right)}^{\left({v}^{2}\right)}}\right)\right)\right)}^{0.5}}}{4} \cdot \left(1 - v \cdot v\right) \]
    5. pow-flip100.0%

      \[\leadsto \frac{{\left(2 \cdot \left(1 - \log \color{blue}{\left({\left(e^{-3}\right)}^{\left(-{v}^{2}\right)}\right)}\right)\right)}^{0.5}}{4} \cdot \left(1 - v \cdot v\right) \]
    6. log-pow100.0%

      \[\leadsto \frac{{\left(2 \cdot \left(1 - \color{blue}{\left(-{v}^{2}\right) \cdot \log \left(e^{-3}\right)}\right)\right)}^{0.5}}{4} \cdot \left(1 - v \cdot v\right) \]
    7. rem-log-exp100.0%

      \[\leadsto \frac{{\left(2 \cdot \left(1 - \left(-{v}^{2}\right) \cdot \color{blue}{-3}\right)\right)}^{0.5}}{4} \cdot \left(1 - v \cdot v\right) \]
  6. Applied egg-rr100.0%

    \[\leadsto \color{blue}{\frac{{\left(2 \cdot \left(1 - \left(-{v}^{2}\right) \cdot -3\right)\right)}^{0.5}}{4}} \cdot \left(1 - v \cdot v\right) \]
  7. Step-by-step derivation
    1. unpow1/2100.0%

      \[\leadsto \frac{\color{blue}{\sqrt{2 \cdot \left(1 - \left(-{v}^{2}\right) \cdot -3\right)}}}{4} \cdot \left(1 - v \cdot v\right) \]
    2. cancel-sign-sub100.0%

      \[\leadsto \frac{\sqrt{2 \cdot \color{blue}{\left(1 + {v}^{2} \cdot -3\right)}}}{4} \cdot \left(1 - v \cdot v\right) \]
    3. distribute-lft-in100.0%

      \[\leadsto \frac{\sqrt{\color{blue}{2 \cdot 1 + 2 \cdot \left({v}^{2} \cdot -3\right)}}}{4} \cdot \left(1 - v \cdot v\right) \]
    4. metadata-eval100.0%

      \[\leadsto \frac{\sqrt{\color{blue}{2} + 2 \cdot \left({v}^{2} \cdot -3\right)}}{4} \cdot \left(1 - v \cdot v\right) \]
  8. Simplified100.0%

    \[\leadsto \color{blue}{\frac{\sqrt{2 + 2 \cdot \left({v}^{2} \cdot -3\right)}}{4}} \cdot \left(1 - v \cdot v\right) \]
  9. Step-by-step derivation
    1. pow2100.0%

      \[\leadsto \frac{\sqrt{2 + 2 \cdot \left(\color{blue}{\left(v \cdot v\right)} \cdot -3\right)}}{4} \cdot \left(1 - v \cdot v\right) \]
  10. Applied egg-rr100.0%

    \[\leadsto \frac{\sqrt{2 + 2 \cdot \left(\color{blue}{\left(v \cdot v\right)} \cdot -3\right)}}{4} \cdot \left(1 - v \cdot v\right) \]
  11. Add Preprocessing

Alternative 2: 99.6% accurate, 2.0× speedup?

\[\begin{array}{l} \\ \sqrt{2} \cdot \left(0.25 + \left(v \cdot v\right) \cdot -0.625\right) \end{array} \]
(FPCore (v) :precision binary64 (* (sqrt 2.0) (+ 0.25 (* (* v v) -0.625))))
double code(double v) {
	return sqrt(2.0) * (0.25 + ((v * v) * -0.625));
}
real(8) function code(v)
    real(8), intent (in) :: v
    code = sqrt(2.0d0) * (0.25d0 + ((v * v) * (-0.625d0)))
end function
public static double code(double v) {
	return Math.sqrt(2.0) * (0.25 + ((v * v) * -0.625));
}
def code(v):
	return math.sqrt(2.0) * (0.25 + ((v * v) * -0.625))
function code(v)
	return Float64(sqrt(2.0) * Float64(0.25 + Float64(Float64(v * v) * -0.625)))
end
function tmp = code(v)
	tmp = sqrt(2.0) * (0.25 + ((v * v) * -0.625));
end
code[v_] := N[(N[Sqrt[2.0], $MachinePrecision] * N[(0.25 + N[(N[(v * v), $MachinePrecision] * -0.625), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\sqrt{2} \cdot \left(0.25 + \left(v \cdot v\right) \cdot -0.625\right)
\end{array}
Derivation
  1. Initial program 100.0%

    \[\left(\frac{\sqrt{2}}{4} \cdot \sqrt{1 - 3 \cdot \left(v \cdot v\right)}\right) \cdot \left(1 - v \cdot v\right) \]
  2. Add Preprocessing
  3. Step-by-step derivation
    1. add-sqr-sqrt100.0%

      \[\leadsto \left(\frac{\sqrt{2}}{4} \cdot \sqrt{1 - \color{blue}{\sqrt{3 \cdot \left(v \cdot v\right)} \cdot \sqrt{3 \cdot \left(v \cdot v\right)}}}\right) \cdot \left(1 - v \cdot v\right) \]
    2. sqrt-unprod100.0%

      \[\leadsto \left(\frac{\sqrt{2}}{4} \cdot \sqrt{1 - \color{blue}{\sqrt{\left(3 \cdot \left(v \cdot v\right)\right) \cdot \left(3 \cdot \left(v \cdot v\right)\right)}}}\right) \cdot \left(1 - v \cdot v\right) \]
    3. swap-sqr100.0%

      \[\leadsto \left(\frac{\sqrt{2}}{4} \cdot \sqrt{1 - \sqrt{\color{blue}{\left(3 \cdot 3\right) \cdot \left(\left(v \cdot v\right) \cdot \left(v \cdot v\right)\right)}}}\right) \cdot \left(1 - v \cdot v\right) \]
    4. metadata-eval100.0%

      \[\leadsto \left(\frac{\sqrt{2}}{4} \cdot \sqrt{1 - \sqrt{\color{blue}{9} \cdot \left(\left(v \cdot v\right) \cdot \left(v \cdot v\right)\right)}}\right) \cdot \left(1 - v \cdot v\right) \]
    5. metadata-eval100.0%

      \[\leadsto \left(\frac{\sqrt{2}}{4} \cdot \sqrt{1 - \sqrt{\color{blue}{\left(-3 \cdot -3\right)} \cdot \left(\left(v \cdot v\right) \cdot \left(v \cdot v\right)\right)}}\right) \cdot \left(1 - v \cdot v\right) \]
    6. swap-sqr100.0%

      \[\leadsto \left(\frac{\sqrt{2}}{4} \cdot \sqrt{1 - \sqrt{\color{blue}{\left(-3 \cdot \left(v \cdot v\right)\right) \cdot \left(-3 \cdot \left(v \cdot v\right)\right)}}}\right) \cdot \left(1 - v \cdot v\right) \]
    7. sqrt-unprod43.4%

      \[\leadsto \left(\frac{\sqrt{2}}{4} \cdot \sqrt{1 - \color{blue}{\sqrt{-3 \cdot \left(v \cdot v\right)} \cdot \sqrt{-3 \cdot \left(v \cdot v\right)}}}\right) \cdot \left(1 - v \cdot v\right) \]
    8. add-sqr-sqrt97.2%

      \[\leadsto \left(\frac{\sqrt{2}}{4} \cdot \sqrt{1 - \color{blue}{-3 \cdot \left(v \cdot v\right)}}\right) \cdot \left(1 - v \cdot v\right) \]
    9. metadata-eval97.2%

      \[\leadsto \left(\frac{\sqrt{2}}{4} \cdot \sqrt{1 - \color{blue}{\left(-3\right)} \cdot \left(v \cdot v\right)}\right) \cdot \left(1 - v \cdot v\right) \]
    10. distribute-lft-neg-in97.2%

      \[\leadsto \left(\frac{\sqrt{2}}{4} \cdot \sqrt{1 - \color{blue}{\left(-3 \cdot \left(v \cdot v\right)\right)}}\right) \cdot \left(1 - v \cdot v\right) \]
    11. add-log-exp97.2%

      \[\leadsto \left(\frac{\sqrt{2}}{4} \cdot \sqrt{1 - \left(-\color{blue}{\log \left(e^{3 \cdot \left(v \cdot v\right)}\right)}\right)}\right) \cdot \left(1 - v \cdot v\right) \]
    12. neg-log97.2%

      \[\leadsto \left(\frac{\sqrt{2}}{4} \cdot \sqrt{1 - \color{blue}{\log \left(\frac{1}{e^{3 \cdot \left(v \cdot v\right)}}\right)}}\right) \cdot \left(1 - v \cdot v\right) \]
    13. add-sqr-sqrt97.2%

      \[\leadsto \left(\frac{\sqrt{2}}{4} \cdot \sqrt{1 - \log \left(\frac{1}{e^{\color{blue}{\sqrt{3 \cdot \left(v \cdot v\right)} \cdot \sqrt{3 \cdot \left(v \cdot v\right)}}}}\right)}\right) \cdot \left(1 - v \cdot v\right) \]
    14. sqrt-unprod97.2%

      \[\leadsto \left(\frac{\sqrt{2}}{4} \cdot \sqrt{1 - \log \left(\frac{1}{e^{\color{blue}{\sqrt{\left(3 \cdot \left(v \cdot v\right)\right) \cdot \left(3 \cdot \left(v \cdot v\right)\right)}}}}\right)}\right) \cdot \left(1 - v \cdot v\right) \]
    15. swap-sqr97.2%

      \[\leadsto \left(\frac{\sqrt{2}}{4} \cdot \sqrt{1 - \log \left(\frac{1}{e^{\sqrt{\color{blue}{\left(3 \cdot 3\right) \cdot \left(\left(v \cdot v\right) \cdot \left(v \cdot v\right)\right)}}}}\right)}\right) \cdot \left(1 - v \cdot v\right) \]
    16. metadata-eval97.2%

      \[\leadsto \left(\frac{\sqrt{2}}{4} \cdot \sqrt{1 - \log \left(\frac{1}{e^{\sqrt{\color{blue}{9} \cdot \left(\left(v \cdot v\right) \cdot \left(v \cdot v\right)\right)}}}\right)}\right) \cdot \left(1 - v \cdot v\right) \]
    17. metadata-eval97.2%

      \[\leadsto \left(\frac{\sqrt{2}}{4} \cdot \sqrt{1 - \log \left(\frac{1}{e^{\sqrt{\color{blue}{\left(-3 \cdot -3\right)} \cdot \left(\left(v \cdot v\right) \cdot \left(v \cdot v\right)\right)}}}\right)}\right) \cdot \left(1 - v \cdot v\right) \]
    18. swap-sqr97.2%

      \[\leadsto \left(\frac{\sqrt{2}}{4} \cdot \sqrt{1 - \log \left(\frac{1}{e^{\sqrt{\color{blue}{\left(-3 \cdot \left(v \cdot v\right)\right) \cdot \left(-3 \cdot \left(v \cdot v\right)\right)}}}}\right)}\right) \cdot \left(1 - v \cdot v\right) \]
    19. sqrt-unprod43.4%

      \[\leadsto \left(\frac{\sqrt{2}}{4} \cdot \sqrt{1 - \log \left(\frac{1}{e^{\color{blue}{\sqrt{-3 \cdot \left(v \cdot v\right)} \cdot \sqrt{-3 \cdot \left(v \cdot v\right)}}}}\right)}\right) \cdot \left(1 - v \cdot v\right) \]
    20. add-sqr-sqrt100.0%

      \[\leadsto \left(\frac{\sqrt{2}}{4} \cdot \sqrt{1 - \log \left(\frac{1}{e^{\color{blue}{-3 \cdot \left(v \cdot v\right)}}}\right)}\right) \cdot \left(1 - v \cdot v\right) \]
    21. exp-prod100.0%

      \[\leadsto \left(\frac{\sqrt{2}}{4} \cdot \sqrt{1 - \log \left(\frac{1}{\color{blue}{{\left(e^{-3}\right)}^{\left(v \cdot v\right)}}}\right)}\right) \cdot \left(1 - v \cdot v\right) \]
    22. pow2100.0%

      \[\leadsto \left(\frac{\sqrt{2}}{4} \cdot \sqrt{1 - \log \left(\frac{1}{{\left(e^{-3}\right)}^{\color{blue}{\left({v}^{2}\right)}}}\right)}\right) \cdot \left(1 - v \cdot v\right) \]
  4. Applied egg-rr100.0%

    \[\leadsto \left(\frac{\sqrt{2}}{4} \cdot \sqrt{1 - \color{blue}{\log \left(\frac{1}{{\left(e^{-3}\right)}^{\left({v}^{2}\right)}}\right)}}\right) \cdot \left(1 - v \cdot v\right) \]
  5. Taylor expanded in v around 0 98.7%

    \[\leadsto \color{blue}{0.25 \cdot \sqrt{2} + 0.25 \cdot \left({v}^{2} \cdot \left(-1.5 \cdot \sqrt{2} + -1 \cdot \sqrt{2}\right)\right)} \]
  6. Step-by-step derivation
    1. *-commutative98.7%

      \[\leadsto 0.25 \cdot \sqrt{2} + 0.25 \cdot \color{blue}{\left(\left(-1.5 \cdot \sqrt{2} + -1 \cdot \sqrt{2}\right) \cdot {v}^{2}\right)} \]
    2. associate-*r*98.7%

      \[\leadsto 0.25 \cdot \sqrt{2} + \color{blue}{\left(0.25 \cdot \left(-1.5 \cdot \sqrt{2} + -1 \cdot \sqrt{2}\right)\right) \cdot {v}^{2}} \]
    3. *-commutative98.7%

      \[\leadsto 0.25 \cdot \sqrt{2} + \color{blue}{\left(\left(-1.5 \cdot \sqrt{2} + -1 \cdot \sqrt{2}\right) \cdot 0.25\right)} \cdot {v}^{2} \]
    4. distribute-rgt-out98.7%

      \[\leadsto 0.25 \cdot \sqrt{2} + \left(\color{blue}{\left(\sqrt{2} \cdot \left(-1.5 + -1\right)\right)} \cdot 0.25\right) \cdot {v}^{2} \]
    5. associate-*l*98.7%

      \[\leadsto 0.25 \cdot \sqrt{2} + \color{blue}{\left(\sqrt{2} \cdot \left(\left(-1.5 + -1\right) \cdot 0.25\right)\right)} \cdot {v}^{2} \]
    6. metadata-eval98.7%

      \[\leadsto 0.25 \cdot \sqrt{2} + \left(\sqrt{2} \cdot \left(\color{blue}{-2.5} \cdot 0.25\right)\right) \cdot {v}^{2} \]
    7. metadata-eval98.7%

      \[\leadsto 0.25 \cdot \sqrt{2} + \left(\sqrt{2} \cdot \color{blue}{-0.625}\right) \cdot {v}^{2} \]
    8. *-commutative98.7%

      \[\leadsto 0.25 \cdot \sqrt{2} + \color{blue}{\left(-0.625 \cdot \sqrt{2}\right)} \cdot {v}^{2} \]
    9. associate-*r*98.7%

      \[\leadsto 0.25 \cdot \sqrt{2} + \color{blue}{-0.625 \cdot \left(\sqrt{2} \cdot {v}^{2}\right)} \]
    10. *-commutative98.7%

      \[\leadsto 0.25 \cdot \sqrt{2} + -0.625 \cdot \color{blue}{\left({v}^{2} \cdot \sqrt{2}\right)} \]
    11. associate-*r*98.7%

      \[\leadsto 0.25 \cdot \sqrt{2} + \color{blue}{\left(-0.625 \cdot {v}^{2}\right) \cdot \sqrt{2}} \]
    12. distribute-rgt-out98.7%

      \[\leadsto \color{blue}{\sqrt{2} \cdot \left(0.25 + -0.625 \cdot {v}^{2}\right)} \]
  7. Simplified98.7%

    \[\leadsto \color{blue}{\sqrt{2} \cdot \left(0.25 + -0.625 \cdot {v}^{2}\right)} \]
  8. Step-by-step derivation
    1. pow2100.0%

      \[\leadsto \frac{\sqrt{2 + 2 \cdot \left(\color{blue}{\left(v \cdot v\right)} \cdot -3\right)}}{4} \cdot \left(1 - v \cdot v\right) \]
  9. Applied egg-rr98.7%

    \[\leadsto \sqrt{2} \cdot \left(0.25 + -0.625 \cdot \color{blue}{\left(v \cdot v\right)}\right) \]
  10. Final simplification98.7%

    \[\leadsto \sqrt{2} \cdot \left(0.25 + \left(v \cdot v\right) \cdot -0.625\right) \]
  11. Add Preprocessing

Alternative 3: 99.0% accurate, 2.1× speedup?

\[\begin{array}{l} \\ \sqrt{2} \cdot 0.25 \end{array} \]
(FPCore (v) :precision binary64 (* (sqrt 2.0) 0.25))
double code(double v) {
	return sqrt(2.0) * 0.25;
}
real(8) function code(v)
    real(8), intent (in) :: v
    code = sqrt(2.0d0) * 0.25d0
end function
public static double code(double v) {
	return Math.sqrt(2.0) * 0.25;
}
def code(v):
	return math.sqrt(2.0) * 0.25
function code(v)
	return Float64(sqrt(2.0) * 0.25)
end
function tmp = code(v)
	tmp = sqrt(2.0) * 0.25;
end
code[v_] := N[(N[Sqrt[2.0], $MachinePrecision] * 0.25), $MachinePrecision]
\begin{array}{l}

\\
\sqrt{2} \cdot 0.25
\end{array}
Derivation
  1. Initial program 100.0%

    \[\left(\frac{\sqrt{2}}{4} \cdot \sqrt{1 - 3 \cdot \left(v \cdot v\right)}\right) \cdot \left(1 - v \cdot v\right) \]
  2. Add Preprocessing
  3. Step-by-step derivation
    1. add-sqr-sqrt100.0%

      \[\leadsto \left(\frac{\sqrt{2}}{4} \cdot \sqrt{1 - \color{blue}{\sqrt{3 \cdot \left(v \cdot v\right)} \cdot \sqrt{3 \cdot \left(v \cdot v\right)}}}\right) \cdot \left(1 - v \cdot v\right) \]
    2. sqrt-unprod100.0%

      \[\leadsto \left(\frac{\sqrt{2}}{4} \cdot \sqrt{1 - \color{blue}{\sqrt{\left(3 \cdot \left(v \cdot v\right)\right) \cdot \left(3 \cdot \left(v \cdot v\right)\right)}}}\right) \cdot \left(1 - v \cdot v\right) \]
    3. swap-sqr100.0%

      \[\leadsto \left(\frac{\sqrt{2}}{4} \cdot \sqrt{1 - \sqrt{\color{blue}{\left(3 \cdot 3\right) \cdot \left(\left(v \cdot v\right) \cdot \left(v \cdot v\right)\right)}}}\right) \cdot \left(1 - v \cdot v\right) \]
    4. metadata-eval100.0%

      \[\leadsto \left(\frac{\sqrt{2}}{4} \cdot \sqrt{1 - \sqrt{\color{blue}{9} \cdot \left(\left(v \cdot v\right) \cdot \left(v \cdot v\right)\right)}}\right) \cdot \left(1 - v \cdot v\right) \]
    5. metadata-eval100.0%

      \[\leadsto \left(\frac{\sqrt{2}}{4} \cdot \sqrt{1 - \sqrt{\color{blue}{\left(-3 \cdot -3\right)} \cdot \left(\left(v \cdot v\right) \cdot \left(v \cdot v\right)\right)}}\right) \cdot \left(1 - v \cdot v\right) \]
    6. swap-sqr100.0%

      \[\leadsto \left(\frac{\sqrt{2}}{4} \cdot \sqrt{1 - \sqrt{\color{blue}{\left(-3 \cdot \left(v \cdot v\right)\right) \cdot \left(-3 \cdot \left(v \cdot v\right)\right)}}}\right) \cdot \left(1 - v \cdot v\right) \]
    7. sqrt-unprod43.4%

      \[\leadsto \left(\frac{\sqrt{2}}{4} \cdot \sqrt{1 - \color{blue}{\sqrt{-3 \cdot \left(v \cdot v\right)} \cdot \sqrt{-3 \cdot \left(v \cdot v\right)}}}\right) \cdot \left(1 - v \cdot v\right) \]
    8. add-sqr-sqrt97.2%

      \[\leadsto \left(\frac{\sqrt{2}}{4} \cdot \sqrt{1 - \color{blue}{-3 \cdot \left(v \cdot v\right)}}\right) \cdot \left(1 - v \cdot v\right) \]
    9. metadata-eval97.2%

      \[\leadsto \left(\frac{\sqrt{2}}{4} \cdot \sqrt{1 - \color{blue}{\left(-3\right)} \cdot \left(v \cdot v\right)}\right) \cdot \left(1 - v \cdot v\right) \]
    10. distribute-lft-neg-in97.2%

      \[\leadsto \left(\frac{\sqrt{2}}{4} \cdot \sqrt{1 - \color{blue}{\left(-3 \cdot \left(v \cdot v\right)\right)}}\right) \cdot \left(1 - v \cdot v\right) \]
    11. add-log-exp97.2%

      \[\leadsto \left(\frac{\sqrt{2}}{4} \cdot \sqrt{1 - \left(-\color{blue}{\log \left(e^{3 \cdot \left(v \cdot v\right)}\right)}\right)}\right) \cdot \left(1 - v \cdot v\right) \]
    12. neg-log97.2%

      \[\leadsto \left(\frac{\sqrt{2}}{4} \cdot \sqrt{1 - \color{blue}{\log \left(\frac{1}{e^{3 \cdot \left(v \cdot v\right)}}\right)}}\right) \cdot \left(1 - v \cdot v\right) \]
    13. add-sqr-sqrt97.2%

      \[\leadsto \left(\frac{\sqrt{2}}{4} \cdot \sqrt{1 - \log \left(\frac{1}{e^{\color{blue}{\sqrt{3 \cdot \left(v \cdot v\right)} \cdot \sqrt{3 \cdot \left(v \cdot v\right)}}}}\right)}\right) \cdot \left(1 - v \cdot v\right) \]
    14. sqrt-unprod97.2%

      \[\leadsto \left(\frac{\sqrt{2}}{4} \cdot \sqrt{1 - \log \left(\frac{1}{e^{\color{blue}{\sqrt{\left(3 \cdot \left(v \cdot v\right)\right) \cdot \left(3 \cdot \left(v \cdot v\right)\right)}}}}\right)}\right) \cdot \left(1 - v \cdot v\right) \]
    15. swap-sqr97.2%

      \[\leadsto \left(\frac{\sqrt{2}}{4} \cdot \sqrt{1 - \log \left(\frac{1}{e^{\sqrt{\color{blue}{\left(3 \cdot 3\right) \cdot \left(\left(v \cdot v\right) \cdot \left(v \cdot v\right)\right)}}}}\right)}\right) \cdot \left(1 - v \cdot v\right) \]
    16. metadata-eval97.2%

      \[\leadsto \left(\frac{\sqrt{2}}{4} \cdot \sqrt{1 - \log \left(\frac{1}{e^{\sqrt{\color{blue}{9} \cdot \left(\left(v \cdot v\right) \cdot \left(v \cdot v\right)\right)}}}\right)}\right) \cdot \left(1 - v \cdot v\right) \]
    17. metadata-eval97.2%

      \[\leadsto \left(\frac{\sqrt{2}}{4} \cdot \sqrt{1 - \log \left(\frac{1}{e^{\sqrt{\color{blue}{\left(-3 \cdot -3\right)} \cdot \left(\left(v \cdot v\right) \cdot \left(v \cdot v\right)\right)}}}\right)}\right) \cdot \left(1 - v \cdot v\right) \]
    18. swap-sqr97.2%

      \[\leadsto \left(\frac{\sqrt{2}}{4} \cdot \sqrt{1 - \log \left(\frac{1}{e^{\sqrt{\color{blue}{\left(-3 \cdot \left(v \cdot v\right)\right) \cdot \left(-3 \cdot \left(v \cdot v\right)\right)}}}}\right)}\right) \cdot \left(1 - v \cdot v\right) \]
    19. sqrt-unprod43.4%

      \[\leadsto \left(\frac{\sqrt{2}}{4} \cdot \sqrt{1 - \log \left(\frac{1}{e^{\color{blue}{\sqrt{-3 \cdot \left(v \cdot v\right)} \cdot \sqrt{-3 \cdot \left(v \cdot v\right)}}}}\right)}\right) \cdot \left(1 - v \cdot v\right) \]
    20. add-sqr-sqrt100.0%

      \[\leadsto \left(\frac{\sqrt{2}}{4} \cdot \sqrt{1 - \log \left(\frac{1}{e^{\color{blue}{-3 \cdot \left(v \cdot v\right)}}}\right)}\right) \cdot \left(1 - v \cdot v\right) \]
    21. exp-prod100.0%

      \[\leadsto \left(\frac{\sqrt{2}}{4} \cdot \sqrt{1 - \log \left(\frac{1}{\color{blue}{{\left(e^{-3}\right)}^{\left(v \cdot v\right)}}}\right)}\right) \cdot \left(1 - v \cdot v\right) \]
    22. pow2100.0%

      \[\leadsto \left(\frac{\sqrt{2}}{4} \cdot \sqrt{1 - \log \left(\frac{1}{{\left(e^{-3}\right)}^{\color{blue}{\left({v}^{2}\right)}}}\right)}\right) \cdot \left(1 - v \cdot v\right) \]
  4. Applied egg-rr100.0%

    \[\leadsto \left(\frac{\sqrt{2}}{4} \cdot \sqrt{1 - \color{blue}{\log \left(\frac{1}{{\left(e^{-3}\right)}^{\left({v}^{2}\right)}}\right)}}\right) \cdot \left(1 - v \cdot v\right) \]
  5. Taylor expanded in v around 0 98.7%

    \[\leadsto \color{blue}{0.25 \cdot \sqrt{2} + 0.25 \cdot \left({v}^{2} \cdot \left(-1.5 \cdot \sqrt{2} + -1 \cdot \sqrt{2}\right)\right)} \]
  6. Step-by-step derivation
    1. *-commutative98.7%

      \[\leadsto 0.25 \cdot \sqrt{2} + 0.25 \cdot \color{blue}{\left(\left(-1.5 \cdot \sqrt{2} + -1 \cdot \sqrt{2}\right) \cdot {v}^{2}\right)} \]
    2. associate-*r*98.7%

      \[\leadsto 0.25 \cdot \sqrt{2} + \color{blue}{\left(0.25 \cdot \left(-1.5 \cdot \sqrt{2} + -1 \cdot \sqrt{2}\right)\right) \cdot {v}^{2}} \]
    3. *-commutative98.7%

      \[\leadsto 0.25 \cdot \sqrt{2} + \color{blue}{\left(\left(-1.5 \cdot \sqrt{2} + -1 \cdot \sqrt{2}\right) \cdot 0.25\right)} \cdot {v}^{2} \]
    4. distribute-rgt-out98.7%

      \[\leadsto 0.25 \cdot \sqrt{2} + \left(\color{blue}{\left(\sqrt{2} \cdot \left(-1.5 + -1\right)\right)} \cdot 0.25\right) \cdot {v}^{2} \]
    5. associate-*l*98.7%

      \[\leadsto 0.25 \cdot \sqrt{2} + \color{blue}{\left(\sqrt{2} \cdot \left(\left(-1.5 + -1\right) \cdot 0.25\right)\right)} \cdot {v}^{2} \]
    6. metadata-eval98.7%

      \[\leadsto 0.25 \cdot \sqrt{2} + \left(\sqrt{2} \cdot \left(\color{blue}{-2.5} \cdot 0.25\right)\right) \cdot {v}^{2} \]
    7. metadata-eval98.7%

      \[\leadsto 0.25 \cdot \sqrt{2} + \left(\sqrt{2} \cdot \color{blue}{-0.625}\right) \cdot {v}^{2} \]
    8. *-commutative98.7%

      \[\leadsto 0.25 \cdot \sqrt{2} + \color{blue}{\left(-0.625 \cdot \sqrt{2}\right)} \cdot {v}^{2} \]
    9. associate-*r*98.7%

      \[\leadsto 0.25 \cdot \sqrt{2} + \color{blue}{-0.625 \cdot \left(\sqrt{2} \cdot {v}^{2}\right)} \]
    10. *-commutative98.7%

      \[\leadsto 0.25 \cdot \sqrt{2} + -0.625 \cdot \color{blue}{\left({v}^{2} \cdot \sqrt{2}\right)} \]
    11. associate-*r*98.7%

      \[\leadsto 0.25 \cdot \sqrt{2} + \color{blue}{\left(-0.625 \cdot {v}^{2}\right) \cdot \sqrt{2}} \]
    12. distribute-rgt-out98.7%

      \[\leadsto \color{blue}{\sqrt{2} \cdot \left(0.25 + -0.625 \cdot {v}^{2}\right)} \]
  7. Simplified98.7%

    \[\leadsto \color{blue}{\sqrt{2} \cdot \left(0.25 + -0.625 \cdot {v}^{2}\right)} \]
  8. Taylor expanded in v around 0 97.2%

    \[\leadsto \color{blue}{0.25 \cdot \sqrt{2}} \]
  9. Final simplification97.2%

    \[\leadsto \sqrt{2} \cdot 0.25 \]
  10. Add Preprocessing

Reproduce

?
herbie shell --seed 2024108 
(FPCore (v)
  :name "Falkner and Boettcher, Appendix B, 2"
  :precision binary64
  (* (* (/ (sqrt 2.0) 4.0) (sqrt (- 1.0 (* 3.0 (* v v))))) (- 1.0 (* v v))))