
(FPCore (v) :precision binary64 (acos (/ (- 1.0 (* 5.0 (* v v))) (- (* v v) 1.0))))
double code(double v) {
return acos(((1.0 - (5.0 * (v * v))) / ((v * v) - 1.0)));
}
real(8) function code(v)
real(8), intent (in) :: v
code = acos(((1.0d0 - (5.0d0 * (v * v))) / ((v * v) - 1.0d0)))
end function
public static double code(double v) {
return Math.acos(((1.0 - (5.0 * (v * v))) / ((v * v) - 1.0)));
}
def code(v): return math.acos(((1.0 - (5.0 * (v * v))) / ((v * v) - 1.0)))
function code(v) return acos(Float64(Float64(1.0 - Float64(5.0 * Float64(v * v))) / Float64(Float64(v * v) - 1.0))) end
function tmp = code(v) tmp = acos(((1.0 - (5.0 * (v * v))) / ((v * v) - 1.0))); end
code[v_] := N[ArcCos[N[(N[(1.0 - N[(5.0 * N[(v * v), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[(N[(v * v), $MachinePrecision] - 1.0), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]
\begin{array}{l}
\\
\cos^{-1} \left(\frac{1 - 5 \cdot \left(v \cdot v\right)}{v \cdot v - 1}\right)
\end{array}
Sampling outcomes in binary64 precision:
Herbie found 7 alternatives:
| Alternative | Accuracy | Speedup |
|---|
(FPCore (v) :precision binary64 (acos (/ (- 1.0 (* 5.0 (* v v))) (- (* v v) 1.0))))
double code(double v) {
return acos(((1.0 - (5.0 * (v * v))) / ((v * v) - 1.0)));
}
real(8) function code(v)
real(8), intent (in) :: v
code = acos(((1.0d0 - (5.0d0 * (v * v))) / ((v * v) - 1.0d0)))
end function
public static double code(double v) {
return Math.acos(((1.0 - (5.0 * (v * v))) / ((v * v) - 1.0)));
}
def code(v): return math.acos(((1.0 - (5.0 * (v * v))) / ((v * v) - 1.0)))
function code(v) return acos(Float64(Float64(1.0 - Float64(5.0 * Float64(v * v))) / Float64(Float64(v * v) - 1.0))) end
function tmp = code(v) tmp = acos(((1.0 - (5.0 * (v * v))) / ((v * v) - 1.0))); end
code[v_] := N[ArcCos[N[(N[(1.0 - N[(5.0 * N[(v * v), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[(N[(v * v), $MachinePrecision] - 1.0), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]
\begin{array}{l}
\\
\cos^{-1} \left(\frac{1 - 5 \cdot \left(v \cdot v\right)}{v \cdot v - 1}\right)
\end{array}
(FPCore (v)
:precision binary64
(let* ((t_0 (/ (fma -5.0 (* v v) 1.0) (fma v v -1.0))) (t_1 (asin t_0)))
(/
(fma
PI
(* PI (* PI -0.125))
(- (pow (fma PI -0.5 (/ 1.0 (/ 1.0 (acos t_0)))) 3.0)))
(- (fma PI (* PI 0.25) (* t_1 (fma PI 0.5 t_1)))))))
double code(double v) {
double t_0 = fma(-5.0, (v * v), 1.0) / fma(v, v, -1.0);
double t_1 = asin(t_0);
return fma(((double) M_PI), (((double) M_PI) * (((double) M_PI) * -0.125)), -pow(fma(((double) M_PI), -0.5, (1.0 / (1.0 / acos(t_0)))), 3.0)) / -fma(((double) M_PI), (((double) M_PI) * 0.25), (t_1 * fma(((double) M_PI), 0.5, t_1)));
}
function code(v) t_0 = Float64(fma(-5.0, Float64(v * v), 1.0) / fma(v, v, -1.0)) t_1 = asin(t_0) return Float64(fma(pi, Float64(pi * Float64(pi * -0.125)), Float64(-(fma(pi, -0.5, Float64(1.0 / Float64(1.0 / acos(t_0)))) ^ 3.0))) / Float64(-fma(pi, Float64(pi * 0.25), Float64(t_1 * fma(pi, 0.5, t_1))))) end
code[v_] := Block[{t$95$0 = N[(N[(-5.0 * N[(v * v), $MachinePrecision] + 1.0), $MachinePrecision] / N[(v * v + -1.0), $MachinePrecision]), $MachinePrecision]}, Block[{t$95$1 = N[ArcSin[t$95$0], $MachinePrecision]}, N[(N[(Pi * N[(Pi * N[(Pi * -0.125), $MachinePrecision]), $MachinePrecision] + (-N[Power[N[(Pi * -0.5 + N[(1.0 / N[(1.0 / N[ArcCos[t$95$0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], 3.0], $MachinePrecision])), $MachinePrecision] / (-N[(Pi * N[(Pi * 0.25), $MachinePrecision] + N[(t$95$1 * N[(Pi * 0.5 + t$95$1), $MachinePrecision]), $MachinePrecision]), $MachinePrecision])), $MachinePrecision]]]
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \frac{\mathsf{fma}\left(-5, v \cdot v, 1\right)}{\mathsf{fma}\left(v, v, -1\right)}\\
t_1 := \sin^{-1} t\_0\\
\frac{\mathsf{fma}\left(\pi, \pi \cdot \left(\pi \cdot -0.125\right), -{\left(\mathsf{fma}\left(\pi, -0.5, \frac{1}{\frac{1}{\cos^{-1} t\_0}}\right)\right)}^{3}\right)}{-\mathsf{fma}\left(\pi, \pi \cdot 0.25, t\_1 \cdot \mathsf{fma}\left(\pi, 0.5, t\_1\right)\right)}
\end{array}
\end{array}
Initial program 99.3%
Applied egg-rr99.2%
lift-*.f64N/A
lift-fma.f64N/A
lift-fma.f64N/A
lift-/.f64N/A
asin-acosN/A
lift-acos.f64N/A
sub-negN/A
lift-PI.f64N/A
div-invN/A
metadata-evalN/A
lower-fma.f64N/A
lower-neg.f6499.3
Applied egg-rr99.3%
Taylor expanded in v around 0
Simplified99.2%
lift-*.f64N/A
lift-fma.f64N/A
lift-fma.f64N/A
lift-/.f64N/A
lift-acos.f6499.2
/-rgt-identityN/A
clear-numN/A
lift-/.f64N/A
lower-/.f6499.3
Applied egg-rr99.3%
Final simplification99.3%
(FPCore (v)
:precision binary64
(let* ((t_0 (asin (/ (fma v (* -5.0 v) 1.0) (fma v v -1.0)))))
(*
(-
(* (* PI (* PI PI)) 0.125)
(pow
(fma PI 0.5 (- (acos (/ (fma -5.0 (* v v) 1.0) (fma v v -1.0)))))
3.0))
(/ 1.0 (fma t_0 (fma PI 0.5 t_0) (* 0.25 (* PI PI)))))))
double code(double v) {
double t_0 = asin((fma(v, (-5.0 * v), 1.0) / fma(v, v, -1.0)));
return (((((double) M_PI) * (((double) M_PI) * ((double) M_PI))) * 0.125) - pow(fma(((double) M_PI), 0.5, -acos((fma(-5.0, (v * v), 1.0) / fma(v, v, -1.0)))), 3.0)) * (1.0 / fma(t_0, fma(((double) M_PI), 0.5, t_0), (0.25 * (((double) M_PI) * ((double) M_PI)))));
}
function code(v) t_0 = asin(Float64(fma(v, Float64(-5.0 * v), 1.0) / fma(v, v, -1.0))) return Float64(Float64(Float64(Float64(pi * Float64(pi * pi)) * 0.125) - (fma(pi, 0.5, Float64(-acos(Float64(fma(-5.0, Float64(v * v), 1.0) / fma(v, v, -1.0))))) ^ 3.0)) * Float64(1.0 / fma(t_0, fma(pi, 0.5, t_0), Float64(0.25 * Float64(pi * pi))))) end
code[v_] := Block[{t$95$0 = N[ArcSin[N[(N[(v * N[(-5.0 * v), $MachinePrecision] + 1.0), $MachinePrecision] / N[(v * v + -1.0), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]}, N[(N[(N[(N[(Pi * N[(Pi * Pi), $MachinePrecision]), $MachinePrecision] * 0.125), $MachinePrecision] - N[Power[N[(Pi * 0.5 + (-N[ArcCos[N[(N[(-5.0 * N[(v * v), $MachinePrecision] + 1.0), $MachinePrecision] / N[(v * v + -1.0), $MachinePrecision]), $MachinePrecision]], $MachinePrecision])), $MachinePrecision], 3.0], $MachinePrecision]), $MachinePrecision] * N[(1.0 / N[(t$95$0 * N[(Pi * 0.5 + t$95$0), $MachinePrecision] + N[(0.25 * N[(Pi * Pi), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \sin^{-1} \left(\frac{\mathsf{fma}\left(v, -5 \cdot v, 1\right)}{\mathsf{fma}\left(v, v, -1\right)}\right)\\
\left(\left(\pi \cdot \left(\pi \cdot \pi\right)\right) \cdot 0.125 - {\left(\mathsf{fma}\left(\pi, 0.5, -\cos^{-1} \left(\frac{\mathsf{fma}\left(-5, v \cdot v, 1\right)}{\mathsf{fma}\left(v, v, -1\right)}\right)\right)\right)}^{3}\right) \cdot \frac{1}{\mathsf{fma}\left(t\_0, \mathsf{fma}\left(\pi, 0.5, t\_0\right), 0.25 \cdot \left(\pi \cdot \pi\right)\right)}
\end{array}
\end{array}
Initial program 99.0%
Applied egg-rr99.0%
lift-*.f64N/A
lift-fma.f64N/A
lift-fma.f64N/A
lift-/.f64N/A
asin-acosN/A
lift-acos.f64N/A
sub-negN/A
lift-PI.f64N/A
div-invN/A
metadata-evalN/A
lower-fma.f64N/A
lower-neg.f6499.0
Applied egg-rr99.0%
Final simplification99.0%
herbie shell --seed 2024218
(FPCore (v)
:name "Falkner and Boettcher, Appendix B, 1"
:precision binary64
(acos (/ (- 1.0 (* 5.0 (* v v))) (- (* v v) 1.0))))