
(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 4 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
(+
(+
1.0
(pow
(sqrt (acos (/ (- 1.0 (* 5.0 (pow v 2.0))) (+ (pow v 2.0) -1.0))))
2.0))
-1.0))
double code(double v) {
return (1.0 + pow(sqrt(acos(((1.0 - (5.0 * pow(v, 2.0))) / (pow(v, 2.0) + -1.0)))), 2.0)) + -1.0;
}
real(8) function code(v)
real(8), intent (in) :: v
code = (1.0d0 + (sqrt(acos(((1.0d0 - (5.0d0 * (v ** 2.0d0))) / ((v ** 2.0d0) + (-1.0d0))))) ** 2.0d0)) + (-1.0d0)
end function
public static double code(double v) {
return (1.0 + Math.pow(Math.sqrt(Math.acos(((1.0 - (5.0 * Math.pow(v, 2.0))) / (Math.pow(v, 2.0) + -1.0)))), 2.0)) + -1.0;
}
def code(v): return (1.0 + math.pow(math.sqrt(math.acos(((1.0 - (5.0 * math.pow(v, 2.0))) / (math.pow(v, 2.0) + -1.0)))), 2.0)) + -1.0
function code(v) return Float64(Float64(1.0 + (sqrt(acos(Float64(Float64(1.0 - Float64(5.0 * (v ^ 2.0))) / Float64((v ^ 2.0) + -1.0)))) ^ 2.0)) + -1.0) end
function tmp = code(v) tmp = (1.0 + (sqrt(acos(((1.0 - (5.0 * (v ^ 2.0))) / ((v ^ 2.0) + -1.0)))) ^ 2.0)) + -1.0; end
code[v_] := N[(N[(1.0 + N[Power[N[Sqrt[N[ArcCos[N[(N[(1.0 - N[(5.0 * N[Power[v, 2.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[(N[Power[v, 2.0], $MachinePrecision] + -1.0), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]], $MachinePrecision], 2.0], $MachinePrecision]), $MachinePrecision] + -1.0), $MachinePrecision]
\begin{array}{l}
\\
\left(1 + {\left(\sqrt{\cos^{-1} \left(\frac{1 - 5 \cdot {v}^{2}}{{v}^{2} + -1}\right)}\right)}^{2}\right) + -1
\end{array}
Initial program 99.4%
acos-asin99.4%
div-inv99.4%
metadata-eval99.4%
pow299.4%
fmm-def99.4%
metadata-eval99.4%
Applied egg-rr99.4%
metadata-eval99.4%
div-inv99.4%
acos-asin99.4%
expm1-log1p-u99.4%
expm1-undefine99.4%
sub-neg99.4%
log1p-undefine99.4%
rem-exp-log99.4%
sub-neg99.4%
*-commutative99.4%
distribute-rgt-neg-in99.4%
metadata-eval99.4%
metadata-eval99.4%
Applied egg-rr99.4%
add-sqr-sqrt99.4%
unpow299.4%
add-cbrt-cube99.4%
add-sqr-sqrt99.4%
cbrt-prod95.9%
*-commutative95.9%
Applied egg-rr99.4%
Taylor expanded in v around inf 99.4%
Final simplification99.4%
(FPCore (v) :precision binary64 (- (* PI 0.5) (asin (/ (- 1.0 (* 5.0 (pow v 2.0))) (fma v v -1.0)))))
double code(double v) {
return (((double) M_PI) * 0.5) - asin(((1.0 - (5.0 * pow(v, 2.0))) / fma(v, v, -1.0)));
}
function code(v) return Float64(Float64(pi * 0.5) - asin(Float64(Float64(1.0 - Float64(5.0 * (v ^ 2.0))) / fma(v, v, -1.0)))) end
code[v_] := N[(N[(Pi * 0.5), $MachinePrecision] - N[ArcSin[N[(N[(1.0 - N[(5.0 * N[Power[v, 2.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[(v * v + -1.0), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\pi \cdot 0.5 - \sin^{-1} \left(\frac{1 - 5 \cdot {v}^{2}}{\mathsf{fma}\left(v, v, -1\right)}\right)
\end{array}
Initial program 99.4%
acos-asin99.4%
div-inv99.4%
metadata-eval99.4%
pow299.4%
fmm-def99.4%
metadata-eval99.4%
Applied egg-rr99.4%
Final simplification99.4%
(FPCore (v) :precision binary64 (acos (/ (- 1.0 (* 5.0 (* v v))) (+ -1.0 (* v v)))))
double code(double v) {
return acos(((1.0 - (5.0 * (v * v))) / (-1.0 + (v * v))));
}
real(8) function code(v)
real(8), intent (in) :: v
code = acos(((1.0d0 - (5.0d0 * (v * v))) / ((-1.0d0) + (v * v))))
end function
public static double code(double v) {
return Math.acos(((1.0 - (5.0 * (v * v))) / (-1.0 + (v * v))));
}
def code(v): return math.acos(((1.0 - (5.0 * (v * v))) / (-1.0 + (v * v))))
function code(v) return acos(Float64(Float64(1.0 - Float64(5.0 * Float64(v * v))) / Float64(-1.0 + Float64(v * v)))) end
function tmp = code(v) tmp = acos(((1.0 - (5.0 * (v * v))) / (-1.0 + (v * v)))); end
code[v_] := N[ArcCos[N[(N[(1.0 - N[(5.0 * N[(v * v), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[(-1.0 + N[(v * v), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]
\begin{array}{l}
\\
\cos^{-1} \left(\frac{1 - 5 \cdot \left(v \cdot v\right)}{-1 + v \cdot v}\right)
\end{array}
Initial program 99.4%
Final simplification99.4%
(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 99.4%
Taylor expanded in v around 0 98.3%
Final simplification98.3%
herbie shell --seed 2024095
(FPCore (v)
:name "Falkner and Boettcher, Appendix B, 1"
:precision binary64
(acos (/ (- 1.0 (* 5.0 (* v v))) (- (* v v) 1.0))))