
(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
(exp
(*
(log
(pow
(cbrt (cbrt (cbrt (acos (/ (fma v (* v -5.0) 1.0) (fma v v -1.0))))))
3.0))
9.0)))
double code(double v) {
return exp((log(pow(cbrt(cbrt(cbrt(acos((fma(v, (v * -5.0), 1.0) / fma(v, v, -1.0)))))), 3.0)) * 9.0));
}
function code(v) return exp(Float64(log((cbrt(cbrt(cbrt(acos(Float64(fma(v, Float64(v * -5.0), 1.0) / fma(v, v, -1.0)))))) ^ 3.0)) * 9.0)) end
code[v_] := N[Exp[N[(N[Log[N[Power[N[Power[N[Power[N[Power[N[ArcCos[N[(N[(v * N[(v * -5.0), $MachinePrecision] + 1.0), $MachinePrecision] / N[(v * v + -1.0), $MachinePrecision]), $MachinePrecision]], $MachinePrecision], 1/3], $MachinePrecision], 1/3], $MachinePrecision], 1/3], $MachinePrecision], 3.0], $MachinePrecision]], $MachinePrecision] * 9.0), $MachinePrecision]], $MachinePrecision]
\begin{array}{l}
\\
e^{\log \left({\left(\sqrt[3]{\sqrt[3]{\sqrt[3]{\cos^{-1} \left(\frac{\mathsf{fma}\left(v, v \cdot -5, 1\right)}{\mathsf{fma}\left(v, v, -1\right)}\right)}}}\right)}^{3}\right) \cdot 9}
\end{array}
Initial program 99.5%
add-log-exp99.5%
add-cube-cbrt99.5%
log-prod99.5%
Applied egg-rr99.5%
log-prod99.5%
count-299.5%
distribute-lft1-in99.5%
metadata-eval99.5%
fma-udef99.5%
metadata-eval99.5%
distribute-rgt-neg-in99.5%
*-commutative99.5%
unpow299.5%
+-commutative99.5%
sub-neg99.5%
metadata-eval99.5%
fma-neg99.5%
Simplified99.5%
add-cube-cbrt95.6%
pow396.0%
Applied egg-rr96.0%
add-log-exp96.0%
*-commutative96.0%
rem-cube-cbrt99.5%
exp-to-pow99.5%
pow399.5%
add-cube-cbrt99.5%
add-log-exp99.5%
add-cube-cbrt97.1%
Applied egg-rr99.5%
add-cube-cbrt99.5%
pow399.5%
Applied egg-rr99.5%
Final simplification99.5%
(FPCore (v) :precision binary64 (exp (* 9.0 (log (cbrt (cbrt (acos (/ (fma v (* v -5.0) 1.0) (fma v v -1.0)))))))))
double code(double v) {
return exp((9.0 * log(cbrt(cbrt(acos((fma(v, (v * -5.0), 1.0) / fma(v, v, -1.0))))))));
}
function code(v) return exp(Float64(9.0 * log(cbrt(cbrt(acos(Float64(fma(v, Float64(v * -5.0), 1.0) / fma(v, v, -1.0)))))))) end
code[v_] := N[Exp[N[(9.0 * N[Log[N[Power[N[Power[N[ArcCos[N[(N[(v * N[(v * -5.0), $MachinePrecision] + 1.0), $MachinePrecision] / N[(v * v + -1.0), $MachinePrecision]), $MachinePrecision]], $MachinePrecision], 1/3], $MachinePrecision], 1/3], $MachinePrecision]], $MachinePrecision]), $MachinePrecision]], $MachinePrecision]
\begin{array}{l}
\\
e^{9 \cdot \log \left(\sqrt[3]{\sqrt[3]{\cos^{-1} \left(\frac{\mathsf{fma}\left(v, v \cdot -5, 1\right)}{\mathsf{fma}\left(v, v, -1\right)}\right)}}\right)}
\end{array}
Initial program 99.5%
add-log-exp99.5%
add-cube-cbrt99.5%
log-prod99.5%
Applied egg-rr99.5%
log-prod99.5%
count-299.5%
distribute-lft1-in99.5%
metadata-eval99.5%
fma-udef99.5%
metadata-eval99.5%
distribute-rgt-neg-in99.5%
*-commutative99.5%
unpow299.5%
+-commutative99.5%
sub-neg99.5%
metadata-eval99.5%
fma-neg99.5%
Simplified99.5%
add-cube-cbrt95.6%
pow396.0%
Applied egg-rr96.0%
add-log-exp96.0%
*-commutative96.0%
rem-cube-cbrt99.5%
exp-to-pow99.5%
pow399.5%
add-cube-cbrt99.5%
add-log-exp99.5%
add-cube-cbrt97.1%
Applied egg-rr99.5%
Final simplification99.5%
(FPCore (v) :precision binary64 (* 3.0 (* (acos (/ (fma v (* v -5.0) 1.0) (fma v v -1.0))) 0.3333333333333333)))
double code(double v) {
return 3.0 * (acos((fma(v, (v * -5.0), 1.0) / fma(v, v, -1.0))) * 0.3333333333333333);
}
function code(v) return Float64(3.0 * Float64(acos(Float64(fma(v, Float64(v * -5.0), 1.0) / fma(v, v, -1.0))) * 0.3333333333333333)) end
code[v_] := N[(3.0 * N[(N[ArcCos[N[(N[(v * N[(v * -5.0), $MachinePrecision] + 1.0), $MachinePrecision] / N[(v * v + -1.0), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] * 0.3333333333333333), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
3 \cdot \left(\cos^{-1} \left(\frac{\mathsf{fma}\left(v, v \cdot -5, 1\right)}{\mathsf{fma}\left(v, v, -1\right)}\right) \cdot 0.3333333333333333\right)
\end{array}
Initial program 99.5%
add-cube-cbrt97.1%
pow398.0%
sub-neg98.0%
+-commutative98.0%
*-commutative98.0%
distribute-rgt-neg-in98.0%
fma-def98.0%
metadata-eval98.0%
fma-neg98.0%
metadata-eval98.0%
Applied egg-rr98.0%
pow1/398.0%
add-sqr-sqrt98.0%
unpow-prod-down97.1%
fma-udef97.1%
associate-*r*97.1%
fma-udef97.1%
fma-udef97.1%
associate-*r*97.1%
fma-udef97.1%
Applied egg-rr97.1%
unpow1/398.0%
unpow1/394.7%
Simplified94.7%
unpow395.0%
Applied egg-rr99.5%
Final simplification99.5%
(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 99.5%
Final simplification99.5%
herbie shell --seed 2023189
(FPCore (v)
:name "Falkner and Boettcher, Appendix B, 1"
:precision binary64
(acos (/ (- 1.0 (* 5.0 (* v v))) (- (* v v) 1.0))))