
(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}
Herbie found 4 alternatives:
| Alternative | Accuracy | Speedup |
|---|
(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}
(FPCore (v) :precision binary64 (/ -1.3333333333333333 (* (* (sqrt (fma (* -6.0 v) v 2.0)) PI) (fma v v -1.0))))
double code(double v) {
return -1.3333333333333333 / ((sqrt(fma((-6.0 * v), v, 2.0)) * ((double) M_PI)) * fma(v, v, -1.0));
}
function code(v) return Float64(-1.3333333333333333 / Float64(Float64(sqrt(fma(Float64(-6.0 * v), v, 2.0)) * pi) * fma(v, v, -1.0))) end
code[v_] := N[(-1.3333333333333333 / N[(N[(N[Sqrt[N[(N[(-6.0 * v), $MachinePrecision] * v + 2.0), $MachinePrecision]], $MachinePrecision] * Pi), $MachinePrecision] * N[(v * v + -1.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{-1.3333333333333333}{\left(\sqrt{\mathsf{fma}\left(-6 \cdot v, v, 2\right)} \cdot \pi\right) \cdot \mathsf{fma}\left(v, v, -1\right)}
\end{array}
Initial program 98.5%
lift-/.f64N/A
lift-*.f64N/A
associate-/r*N/A
lower-/.f64N/A
lift-*.f64N/A
lift-*.f64N/A
associate-*l*N/A
associate-/r*N/A
lower-/.f64N/A
metadata-evalN/A
*-commutativeN/A
lower-*.f64100.0
lift--.f64N/A
sub-flipN/A
+-commutativeN/A
lift-*.f64N/A
distribute-lft-neg-outN/A
Applied rewrites100.0%
lift-fma.f64N/A
lift-*.f64N/A
associate-*l*N/A
lift-*.f64N/A
lift-fma.f64100.0
Applied rewrites100.0%
lift-/.f64N/A
lift-/.f64N/A
associate-/l/N/A
frac-2negN/A
lift-*.f64N/A
*-commutativeN/A
lift-fma.f64N/A
lift-*.f64N/A
associate-*l*N/A
lift-*.f64N/A
lift-fma.f64N/A
associate-*l*N/A
*-commutativeN/A
lift-*.f64N/A
lift-*.f64N/A
Applied rewrites100.0%
(FPCore (v) :precision binary64 (/ (/ 4.0 (sqrt (fma -6.0 (* v v) 2.0))) (* 3.0 PI)))
double code(double v) {
return (4.0 / sqrt(fma(-6.0, (v * v), 2.0))) / (3.0 * ((double) M_PI));
}
function code(v) return Float64(Float64(4.0 / sqrt(fma(-6.0, Float64(v * v), 2.0))) / Float64(3.0 * pi)) end
code[v_] := N[(N[(4.0 / N[Sqrt[N[(-6.0 * N[(v * v), $MachinePrecision] + 2.0), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] / N[(3.0 * Pi), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{\frac{4}{\sqrt{\mathsf{fma}\left(-6, v \cdot v, 2\right)}}}{3 \cdot \pi}
\end{array}
Initial program 98.5%
Taylor expanded in v around 0
lower-*.f64N/A
lower-PI.f6497.5
Applied rewrites97.5%
lift-/.f64N/A
lift-*.f64N/A
*-commutativeN/A
associate-/r*N/A
lower-/.f64N/A
lower-/.f6499.0
lift--.f64N/A
lift-*.f64N/A
fp-cancel-sub-sign-invN/A
metadata-evalN/A
+-commutativeN/A
lift-fma.f6499.0
Applied rewrites99.0%
(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(1.3333333333333333 / Float64(sqrt(fma(Float64(-6.0 * v), v, 2.0)) * pi)) end
code[v_] := N[(1.3333333333333333 / N[(N[Sqrt[N[(N[(-6.0 * v), $MachinePrecision] * v + 2.0), $MachinePrecision]], $MachinePrecision] * Pi), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{1.3333333333333333}{\sqrt{\mathsf{fma}\left(-6 \cdot v, v, 2\right)} \cdot \pi}
\end{array}
Initial program 98.5%
lift-/.f64N/A
lift-*.f64N/A
associate-/r*N/A
lower-/.f64N/A
lift-*.f64N/A
lift-*.f64N/A
associate-*l*N/A
associate-/r*N/A
lower-/.f64N/A
metadata-evalN/A
*-commutativeN/A
lower-*.f64100.0
lift--.f64N/A
sub-flipN/A
+-commutativeN/A
lift-*.f64N/A
distribute-lft-neg-outN/A
Applied rewrites100.0%
Taylor expanded in v around 0
lower-PI.f6499.0
Applied rewrites99.0%
lift-/.f64N/A
lift-/.f64N/A
associate-/l/N/A
lower-/.f64N/A
*-commutativeN/A
lower-*.f6499.0
lift-fma.f64N/A
lift-*.f64N/A
associate-*l*N/A
lift-*.f64N/A
lift-fma.f6499.0
Applied rewrites99.0%
(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}
Initial program 98.5%
Taylor expanded in v around 0
lower-/.f64N/A
lower-*.f64N/A
lower-PI.f64N/A
lower-sqrt.f6498.9
Applied rewrites98.9%
herbie shell --seed 2025150
(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)))))))