
(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 5 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 (* v v) -5.0 1.0)))
(+
(* 2.0 (log (cbrt (exp (acos (/ t_0 (fma v v -1.0)))))))
(log (cbrt (exp (acos (* t_0 (/ 1.0 (fma v v -1.0))))))))))
double code(double v) {
double t_0 = fma((v * v), -5.0, 1.0);
return (2.0 * log(cbrt(exp(acos((t_0 / fma(v, v, -1.0))))))) + log(cbrt(exp(acos((t_0 * (1.0 / fma(v, v, -1.0)))))));
}
function code(v) t_0 = fma(Float64(v * v), -5.0, 1.0) return Float64(Float64(2.0 * log(cbrt(exp(acos(Float64(t_0 / fma(v, v, -1.0))))))) + log(cbrt(exp(acos(Float64(t_0 * Float64(1.0 / fma(v, v, -1.0)))))))) end
code[v_] := Block[{t$95$0 = N[(N[(v * v), $MachinePrecision] * -5.0 + 1.0), $MachinePrecision]}, N[(N[(2.0 * N[Log[N[Power[N[Exp[N[ArcCos[N[(t$95$0 / N[(v * v + -1.0), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]], $MachinePrecision], 1/3], $MachinePrecision]], $MachinePrecision]), $MachinePrecision] + N[Log[N[Power[N[Exp[N[ArcCos[N[(t$95$0 * N[(1.0 / N[(v * v + -1.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]], $MachinePrecision], 1/3], $MachinePrecision]], $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \mathsf{fma}\left(v \cdot v, -5, 1\right)\\
2 \cdot \log \left(\sqrt[3]{e^{\cos^{-1} \left(\frac{t_0}{\mathsf{fma}\left(v, v, -1\right)}\right)}}\right) + \log \left(\sqrt[3]{e^{\cos^{-1} \left(t_0 \cdot \frac{1}{\mathsf{fma}\left(v, v, -1\right)}\right)}}\right)
\end{array}
\end{array}
Initial program 99.1%
add-log-exp99.1%
add-cube-cbrt99.1%
log-prod99.1%
Applied egg-rr99.1%
log-prod99.1%
count-299.1%
Simplified99.1%
div-inv99.1%
Applied egg-rr99.1%
Final simplification99.1%
(FPCore (v) :precision binary64 (* (log (cbrt (exp (acos (/ (fma (* v v) -5.0 1.0) (fma v v -1.0)))))) 3.0))
double code(double v) {
return log(cbrt(exp(acos((fma((v * v), -5.0, 1.0) / fma(v, v, -1.0)))))) * 3.0;
}
function code(v) return Float64(log(cbrt(exp(acos(Float64(fma(Float64(v * v), -5.0, 1.0) / fma(v, v, -1.0)))))) * 3.0) end
code[v_] := N[(N[Log[N[Power[N[Exp[N[ArcCos[N[(N[(N[(v * v), $MachinePrecision] * -5.0 + 1.0), $MachinePrecision] / N[(v * v + -1.0), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]], $MachinePrecision], 1/3], $MachinePrecision]], $MachinePrecision] * 3.0), $MachinePrecision]
\begin{array}{l}
\\
\log \left(\sqrt[3]{e^{\cos^{-1} \left(\frac{\mathsf{fma}\left(v \cdot v, -5, 1\right)}{\mathsf{fma}\left(v, v, -1\right)}\right)}}\right) \cdot 3
\end{array}
Initial program 99.1%
add-log-exp99.1%
add-cube-cbrt99.1%
log-prod99.1%
Applied egg-rr99.1%
log-prod99.1%
count-299.1%
Simplified99.1%
distribute-lft1-in99.1%
metadata-eval99.1%
Applied egg-rr99.1%
Final simplification99.1%
(FPCore (v) :precision binary64 (acos (/ (- 1.0 (pow (cbrt (* (* v v) 5.0)) 3.0)) (+ (* v v) -1.0))))
double code(double v) {
return acos(((1.0 - pow(cbrt(((v * v) * 5.0)), 3.0)) / ((v * v) + -1.0)));
}
public static double code(double v) {
return Math.acos(((1.0 - Math.pow(Math.cbrt(((v * v) * 5.0)), 3.0)) / ((v * v) + -1.0)));
}
function code(v) return acos(Float64(Float64(1.0 - (cbrt(Float64(Float64(v * v) * 5.0)) ^ 3.0)) / Float64(Float64(v * v) + -1.0))) end
code[v_] := N[ArcCos[N[(N[(1.0 - N[Power[N[Power[N[(N[(v * v), $MachinePrecision] * 5.0), $MachinePrecision], 1/3], $MachinePrecision], 3.0], $MachinePrecision]), $MachinePrecision] / N[(N[(v * v), $MachinePrecision] + -1.0), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]
\begin{array}{l}
\\
\cos^{-1} \left(\frac{1 - {\left(\sqrt[3]{\left(v \cdot v\right) \cdot 5}\right)}^{3}}{v \cdot v + -1}\right)
\end{array}
Initial program 99.1%
add-cube-cbrt99.1%
pow399.1%
Applied egg-rr99.1%
Final simplification99.1%
(FPCore (v) :precision binary64 (acos (/ (- 1.0 (* (* v v) 5.0)) (+ (* v v) -1.0))))
double code(double v) {
return acos(((1.0 - ((v * v) * 5.0)) / ((v * v) + -1.0)));
}
real(8) function code(v)
real(8), intent (in) :: v
code = acos(((1.0d0 - ((v * v) * 5.0d0)) / ((v * v) + (-1.0d0))))
end function
public static double code(double v) {
return Math.acos(((1.0 - ((v * v) * 5.0)) / ((v * v) + -1.0)));
}
def code(v): return math.acos(((1.0 - ((v * v) * 5.0)) / ((v * v) + -1.0)))
function code(v) return acos(Float64(Float64(1.0 - Float64(Float64(v * v) * 5.0)) / Float64(Float64(v * v) + -1.0))) end
function tmp = code(v) tmp = acos(((1.0 - ((v * v) * 5.0)) / ((v * v) + -1.0))); end
code[v_] := N[ArcCos[N[(N[(1.0 - N[(N[(v * v), $MachinePrecision] * 5.0), $MachinePrecision]), $MachinePrecision] / N[(N[(v * v), $MachinePrecision] + -1.0), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]
\begin{array}{l}
\\
\cos^{-1} \left(\frac{1 - \left(v \cdot v\right) \cdot 5}{v \cdot v + -1}\right)
\end{array}
Initial program 99.1%
Final simplification99.1%
(FPCore (v) :precision binary64 (acos -1.0))
double code(double v) {
return acos(-1.0);
}
real(8) function code(v)
real(8), intent (in) :: v
code = acos((-1.0d0))
end function
public static double code(double v) {
return Math.acos(-1.0);
}
def code(v): return math.acos(-1.0)
function code(v) return acos(-1.0) end
function tmp = code(v) tmp = acos(-1.0); end
code[v_] := N[ArcCos[-1.0], $MachinePrecision]
\begin{array}{l}
\\
\cos^{-1} -1
\end{array}
Initial program 99.1%
Taylor expanded in v around 0 97.8%
Final simplification97.8%
herbie shell --seed 2023207
(FPCore (v)
:name "Falkner and Boettcher, Appendix B, 1"
:precision binary64
(acos (/ (- 1.0 (* 5.0 (* v v))) (- (* v v) 1.0))))