
(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 (expm1 (log1p (- (* PI 0.5) (asin (/ (fma v (* v -5.0) 1.0) (fma v v -1.0)))))))
double code(double v) {
return expm1(log1p(((((double) M_PI) * 0.5) - asin((fma(v, (v * -5.0), 1.0) / fma(v, v, -1.0))))));
}
function code(v) return expm1(log1p(Float64(Float64(pi * 0.5) - asin(Float64(fma(v, Float64(v * -5.0), 1.0) / fma(v, v, -1.0)))))) end
code[v_] := N[(Exp[N[Log[1 + N[(N[(Pi * 0.5), $MachinePrecision] - N[ArcSin[N[(N[(v * N[(v * -5.0), $MachinePrecision] + 1.0), $MachinePrecision] / N[(v * v + -1.0), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]], $MachinePrecision]] - 1), $MachinePrecision]
\begin{array}{l}
\\
\mathsf{expm1}\left(\mathsf{log1p}\left(\pi \cdot 0.5 - \sin^{-1} \left(\frac{\mathsf{fma}\left(v, v \cdot -5, 1\right)}{\mathsf{fma}\left(v, v, -1\right)}\right)\right)\right)
\end{array}
Initial program 98.9%
expm1-log1p-u98.9%
sub-neg98.9%
+-commutative98.9%
*-commutative98.9%
distribute-rgt-neg-in98.9%
fma-def98.9%
metadata-eval98.9%
fma-neg98.9%
metadata-eval98.9%
Applied egg-rr98.9%
acos-asin98.9%
div-inv98.9%
metadata-eval98.9%
fma-udef98.9%
associate-*l*98.9%
fma-def98.9%
Applied egg-rr98.9%
Final simplification98.9%
(FPCore (v) :precision binary64 (expm1 (log1p (acos (/ (fma (* v v) -5.0 1.0) (fma v v -1.0))))))
double code(double v) {
return expm1(log1p(acos((fma((v * v), -5.0, 1.0) / fma(v, v, -1.0)))));
}
function code(v) return expm1(log1p(acos(Float64(fma(Float64(v * v), -5.0, 1.0) / fma(v, v, -1.0))))) end
code[v_] := N[(Exp[N[Log[1 + N[ArcCos[N[(N[(N[(v * v), $MachinePrecision] * -5.0 + 1.0), $MachinePrecision] / N[(v * v + -1.0), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]], $MachinePrecision]] - 1), $MachinePrecision]
\begin{array}{l}
\\
\mathsf{expm1}\left(\mathsf{log1p}\left(\cos^{-1} \left(\frac{\mathsf{fma}\left(v \cdot v, -5, 1\right)}{\mathsf{fma}\left(v, v, -1\right)}\right)\right)\right)
\end{array}
Initial program 98.9%
expm1-log1p-u98.9%
sub-neg98.9%
+-commutative98.9%
*-commutative98.9%
distribute-rgt-neg-in98.9%
fma-def98.9%
metadata-eval98.9%
fma-neg98.9%
metadata-eval98.9%
Applied egg-rr98.9%
Final simplification98.9%
(FPCore (v) :precision binary64 (- (* PI 0.5) (asin (/ (fma (* v v) -5.0 1.0) (fma v v -1.0)))))
double code(double v) {
return (((double) M_PI) * 0.5) - asin((fma((v * v), -5.0, 1.0) / fma(v, v, -1.0)));
}
function code(v) return Float64(Float64(pi * 0.5) - asin(Float64(fma(Float64(v * v), -5.0, 1.0) / fma(v, v, -1.0)))) end
code[v_] := N[(N[(Pi * 0.5), $MachinePrecision] - N[ArcSin[N[(N[(N[(v * v), $MachinePrecision] * -5.0 + 1.0), $MachinePrecision] / N[(v * v + -1.0), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\pi \cdot 0.5 - \sin^{-1} \left(\frac{\mathsf{fma}\left(v \cdot v, -5, 1\right)}{\mathsf{fma}\left(v, v, -1\right)}\right)
\end{array}
Initial program 98.9%
acos-asin98.9%
sub-neg98.9%
div-inv98.9%
metadata-eval98.9%
sub-neg98.9%
+-commutative98.9%
*-commutative98.9%
distribute-rgt-neg-in98.9%
fma-def98.9%
metadata-eval98.9%
fma-neg98.9%
metadata-eval98.9%
Applied egg-rr98.9%
sub-neg98.9%
Simplified98.9%
Final simplification98.9%
(FPCore (v) :precision binary64 (acos (/ (- 1.0 (* (* v v) 5.0)) (+ -1.0 (* v v)))))
double code(double v) {
return acos(((1.0 - ((v * v) * 5.0)) / (-1.0 + (v * v))));
}
real(8) function code(v)
real(8), intent (in) :: v
code = acos(((1.0d0 - ((v * v) * 5.0d0)) / ((-1.0d0) + (v * v))))
end function
public static double code(double v) {
return Math.acos(((1.0 - ((v * v) * 5.0)) / (-1.0 + (v * v))));
}
def code(v): return math.acos(((1.0 - ((v * v) * 5.0)) / (-1.0 + (v * v))))
function code(v) return acos(Float64(Float64(1.0 - Float64(Float64(v * v) * 5.0)) / Float64(-1.0 + Float64(v * v)))) end
function tmp = code(v) tmp = acos(((1.0 - ((v * v) * 5.0)) / (-1.0 + (v * v)))); end
code[v_] := N[ArcCos[N[(N[(1.0 - N[(N[(v * v), $MachinePrecision] * 5.0), $MachinePrecision]), $MachinePrecision] / N[(-1.0 + N[(v * v), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]
\begin{array}{l}
\\
\cos^{-1} \left(\frac{1 - \left(v \cdot v\right) \cdot 5}{-1 + v \cdot v}\right)
\end{array}
Initial program 98.9%
Final simplification98.9%
(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 98.9%
Taylor expanded in v around 0 97.1%
Final simplification97.1%
herbie shell --seed 2023285
(FPCore (v)
:name "Falkner and Boettcher, Appendix B, 1"
:precision binary64
(acos (/ (- 1.0 (* 5.0 (* v v))) (- (* v v) 1.0))))