
(FPCore (k n) :precision binary64 (* (/ 1.0 (sqrt k)) (pow (* (* 2.0 PI) n) (/ (- 1.0 k) 2.0))))
double code(double k, double n) {
return (1.0 / sqrt(k)) * pow(((2.0 * ((double) M_PI)) * n), ((1.0 - k) / 2.0));
}
public static double code(double k, double n) {
return (1.0 / Math.sqrt(k)) * Math.pow(((2.0 * Math.PI) * n), ((1.0 - k) / 2.0));
}
def code(k, n): return (1.0 / math.sqrt(k)) * math.pow(((2.0 * math.pi) * n), ((1.0 - k) / 2.0))
function code(k, n) return Float64(Float64(1.0 / sqrt(k)) * (Float64(Float64(2.0 * pi) * n) ^ Float64(Float64(1.0 - k) / 2.0))) end
function tmp = code(k, n) tmp = (1.0 / sqrt(k)) * (((2.0 * pi) * n) ^ ((1.0 - k) / 2.0)); end
code[k_, n_] := N[(N[(1.0 / N[Sqrt[k], $MachinePrecision]), $MachinePrecision] * N[Power[N[(N[(2.0 * Pi), $MachinePrecision] * n), $MachinePrecision], N[(N[(1.0 - k), $MachinePrecision] / 2.0), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{1}{\sqrt{k}} \cdot {\left(\left(2 \cdot \pi\right) \cdot n\right)}^{\left(\frac{1 - k}{2}\right)}
\end{array}
Sampling outcomes in binary64 precision:
Herbie found 5 alternatives:
| Alternative | Accuracy | Speedup |
|---|
(FPCore (k n) :precision binary64 (* (/ 1.0 (sqrt k)) (pow (* (* 2.0 PI) n) (/ (- 1.0 k) 2.0))))
double code(double k, double n) {
return (1.0 / sqrt(k)) * pow(((2.0 * ((double) M_PI)) * n), ((1.0 - k) / 2.0));
}
public static double code(double k, double n) {
return (1.0 / Math.sqrt(k)) * Math.pow(((2.0 * Math.PI) * n), ((1.0 - k) / 2.0));
}
def code(k, n): return (1.0 / math.sqrt(k)) * math.pow(((2.0 * math.pi) * n), ((1.0 - k) / 2.0))
function code(k, n) return Float64(Float64(1.0 / sqrt(k)) * (Float64(Float64(2.0 * pi) * n) ^ Float64(Float64(1.0 - k) / 2.0))) end
function tmp = code(k, n) tmp = (1.0 / sqrt(k)) * (((2.0 * pi) * n) ^ ((1.0 - k) / 2.0)); end
code[k_, n_] := N[(N[(1.0 / N[Sqrt[k], $MachinePrecision]), $MachinePrecision] * N[Power[N[(N[(2.0 * Pi), $MachinePrecision] * n), $MachinePrecision], N[(N[(1.0 - k), $MachinePrecision] / 2.0), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{1}{\sqrt{k}} \cdot {\left(\left(2 \cdot \pi\right) \cdot n\right)}^{\left(\frac{1 - k}{2}\right)}
\end{array}
(FPCore (k n) :precision binary64 (/ (pow (* (* PI 2.0) n) (/ (- 1.0 k) 2.0)) (sqrt k)))
double code(double k, double n) {
return pow(((((double) M_PI) * 2.0) * n), ((1.0 - k) / 2.0)) / sqrt(k);
}
public static double code(double k, double n) {
return Math.pow(((Math.PI * 2.0) * n), ((1.0 - k) / 2.0)) / Math.sqrt(k);
}
def code(k, n): return math.pow(((math.pi * 2.0) * n), ((1.0 - k) / 2.0)) / math.sqrt(k)
function code(k, n) return Float64((Float64(Float64(pi * 2.0) * n) ^ Float64(Float64(1.0 - k) / 2.0)) / sqrt(k)) end
function tmp = code(k, n) tmp = (((pi * 2.0) * n) ^ ((1.0 - k) / 2.0)) / sqrt(k); end
code[k_, n_] := N[(N[Power[N[(N[(Pi * 2.0), $MachinePrecision] * n), $MachinePrecision], N[(N[(1.0 - k), $MachinePrecision] / 2.0), $MachinePrecision]], $MachinePrecision] / N[Sqrt[k], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{{\left(\left(\pi \cdot 2\right) \cdot n\right)}^{\left(\frac{1 - k}{2}\right)}}{\sqrt{k}}
\end{array}
Initial program 99.5%
lift-*.f64N/A
lift-/.f64N/A
lift-sqrt.f64N/A
lift-pow.f64N/A
lift-*.f64N/A
lift-PI.f64N/A
lift-*.f64N/A
lift--.f64N/A
lift-/.f64N/A
associate-*l/N/A
lower-/.f64N/A
Applied rewrites99.6%
Final simplification99.6%
(FPCore (k n) :precision binary64 (if (<= (* (/ 1.0 (sqrt k)) (pow (* (* 2.0 PI) n) (/ (- 1.0 k) 2.0))) 1e+140) (sqrt (* PI (* (/ n k) 2.0))) (/ (sqrt (* (* (* PI n) k) 2.0)) k)))
double code(double k, double n) {
double tmp;
if (((1.0 / sqrt(k)) * pow(((2.0 * ((double) M_PI)) * n), ((1.0 - k) / 2.0))) <= 1e+140) {
tmp = sqrt((((double) M_PI) * ((n / k) * 2.0)));
} else {
tmp = sqrt((((((double) M_PI) * n) * k) * 2.0)) / k;
}
return tmp;
}
public static double code(double k, double n) {
double tmp;
if (((1.0 / Math.sqrt(k)) * Math.pow(((2.0 * Math.PI) * n), ((1.0 - k) / 2.0))) <= 1e+140) {
tmp = Math.sqrt((Math.PI * ((n / k) * 2.0)));
} else {
tmp = Math.sqrt((((Math.PI * n) * k) * 2.0)) / k;
}
return tmp;
}
def code(k, n): tmp = 0 if ((1.0 / math.sqrt(k)) * math.pow(((2.0 * math.pi) * n), ((1.0 - k) / 2.0))) <= 1e+140: tmp = math.sqrt((math.pi * ((n / k) * 2.0))) else: tmp = math.sqrt((((math.pi * n) * k) * 2.0)) / k return tmp
function code(k, n) tmp = 0.0 if (Float64(Float64(1.0 / sqrt(k)) * (Float64(Float64(2.0 * pi) * n) ^ Float64(Float64(1.0 - k) / 2.0))) <= 1e+140) tmp = sqrt(Float64(pi * Float64(Float64(n / k) * 2.0))); else tmp = Float64(sqrt(Float64(Float64(Float64(pi * n) * k) * 2.0)) / k); end return tmp end
function tmp_2 = code(k, n) tmp = 0.0; if (((1.0 / sqrt(k)) * (((2.0 * pi) * n) ^ ((1.0 - k) / 2.0))) <= 1e+140) tmp = sqrt((pi * ((n / k) * 2.0))); else tmp = sqrt((((pi * n) * k) * 2.0)) / k; end tmp_2 = tmp; end
code[k_, n_] := If[LessEqual[N[(N[(1.0 / N[Sqrt[k], $MachinePrecision]), $MachinePrecision] * N[Power[N[(N[(2.0 * Pi), $MachinePrecision] * n), $MachinePrecision], N[(N[(1.0 - k), $MachinePrecision] / 2.0), $MachinePrecision]], $MachinePrecision]), $MachinePrecision], 1e+140], N[Sqrt[N[(Pi * N[(N[(n / k), $MachinePrecision] * 2.0), $MachinePrecision]), $MachinePrecision]], $MachinePrecision], N[(N[Sqrt[N[(N[(N[(Pi * n), $MachinePrecision] * k), $MachinePrecision] * 2.0), $MachinePrecision]], $MachinePrecision] / k), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;\frac{1}{\sqrt{k}} \cdot {\left(\left(2 \cdot \pi\right) \cdot n\right)}^{\left(\frac{1 - k}{2}\right)} \leq 10^{+140}:\\
\;\;\;\;\sqrt{\pi \cdot \left(\frac{n}{k} \cdot 2\right)}\\
\mathbf{else}:\\
\;\;\;\;\frac{\sqrt{\left(\left(\pi \cdot n\right) \cdot k\right) \cdot 2}}{k}\\
\end{array}
\end{array}
if (*.f64 (/.f64 #s(literal 1 binary64) (sqrt.f64 k)) (pow.f64 (*.f64 (*.f64 #s(literal 2 binary64) (PI.f64)) n) (/.f64 (-.f64 #s(literal 1 binary64) k) #s(literal 2 binary64)))) < 1.00000000000000006e140Initial program 99.5%
Taylor expanded in k around 0
sqrt-unprodN/A
lower-sqrt.f64N/A
lower-*.f64N/A
lower-/.f64N/A
*-commutativeN/A
lower-*.f64N/A
lift-PI.f6459.7
Applied rewrites59.7%
lift-/.f64N/A
lift-PI.f64N/A
lift-*.f64N/A
associate-/l*N/A
lower-*.f64N/A
lift-PI.f64N/A
lower-/.f6459.8
Applied rewrites59.8%
lift-*.f64N/A
lift-PI.f64N/A
lift-*.f64N/A
associate-*l*N/A
lower-*.f64N/A
lift-PI.f64N/A
lower-*.f6459.8
Applied rewrites59.8%
if 1.00000000000000006e140 < (*.f64 (/.f64 #s(literal 1 binary64) (sqrt.f64 k)) (pow.f64 (*.f64 (*.f64 #s(literal 2 binary64) (PI.f64)) n) (/.f64 (-.f64 #s(literal 1 binary64) k) #s(literal 2 binary64)))) Initial program 99.6%
Taylor expanded in k around 0
lower-/.f64N/A
Applied rewrites72.6%
Taylor expanded in k around 0
*-commutativeN/A
*-commutativeN/A
sqrt-prodN/A
lower-sqrt.f64N/A
lift-*.f64N/A
lift-PI.f64N/A
lift-*.f64N/A
lift-*.f6427.9
Applied rewrites27.9%
(FPCore (k n) :precision binary64 (* (sqrt (/ 1.0 k)) (pow (* (+ PI PI) n) (fma -0.5 k 0.5))))
double code(double k, double n) {
return sqrt((1.0 / k)) * pow(((((double) M_PI) + ((double) M_PI)) * n), fma(-0.5, k, 0.5));
}
function code(k, n) return Float64(sqrt(Float64(1.0 / k)) * (Float64(Float64(pi + pi) * n) ^ fma(-0.5, k, 0.5))) end
code[k_, n_] := N[(N[Sqrt[N[(1.0 / k), $MachinePrecision]], $MachinePrecision] * N[Power[N[(N[(Pi + Pi), $MachinePrecision] * n), $MachinePrecision], N[(-0.5 * k + 0.5), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\sqrt{\frac{1}{k}} \cdot {\left(\left(\pi + \pi\right) \cdot n\right)}^{\left(\mathsf{fma}\left(-0.5, k, 0.5\right)\right)}
\end{array}
Initial program 99.5%
Taylor expanded in k around 0
+-commutativeN/A
lower-fma.f6499.5
Applied rewrites99.5%
lift-/.f64N/A
metadata-evalN/A
lift-sqrt.f64N/A
sqrt-divN/A
lower-sqrt.f64N/A
inv-powN/A
lower-pow.f6499.6
Applied rewrites99.6%
lift-pow.f64N/A
inv-powN/A
lower-/.f6499.6
Applied rewrites99.6%
lift-PI.f64N/A
lift-*.f64N/A
count-2-revN/A
lower-+.f64N/A
lift-PI.f64N/A
lift-PI.f6499.6
Applied rewrites99.6%
(FPCore (k n) :precision binary64 (/ (sqrt (* (* 2.0 n) PI)) (sqrt k)))
double code(double k, double n) {
return sqrt(((2.0 * n) * ((double) M_PI))) / sqrt(k);
}
public static double code(double k, double n) {
return Math.sqrt(((2.0 * n) * Math.PI)) / Math.sqrt(k);
}
def code(k, n): return math.sqrt(((2.0 * n) * math.pi)) / math.sqrt(k)
function code(k, n) return Float64(sqrt(Float64(Float64(2.0 * n) * pi)) / sqrt(k)) end
function tmp = code(k, n) tmp = sqrt(((2.0 * n) * pi)) / sqrt(k); end
code[k_, n_] := N[(N[Sqrt[N[(N[(2.0 * n), $MachinePrecision] * Pi), $MachinePrecision]], $MachinePrecision] / N[Sqrt[k], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{\sqrt{\left(2 \cdot n\right) \cdot \pi}}{\sqrt{k}}
\end{array}
Initial program 99.5%
lift-*.f64N/A
lift-/.f64N/A
lift-sqrt.f64N/A
lift-pow.f64N/A
lift-*.f64N/A
lift-PI.f64N/A
lift-*.f64N/A
lift--.f64N/A
lift-/.f64N/A
associate-*l/N/A
lower-/.f64N/A
Applied rewrites99.6%
Taylor expanded in k around 0
*-lft-identityN/A
lift-*.f64N/A
lift-PI.f64N/A
lift-*.f64N/A
sqr-powN/A
lift-*.f64N/A
lift-PI.f64N/A
lift-*.f64N/A
lift-*.f64N/A
lift-PI.f64N/A
lift-*.f64N/A
sqrt-unprodN/A
*-commutativeN/A
*-commutativeN/A
Applied rewrites47.0%
(FPCore (k n) :precision binary64 (sqrt (* PI (* (/ n k) 2.0))))
double code(double k, double n) {
return sqrt((((double) M_PI) * ((n / k) * 2.0)));
}
public static double code(double k, double n) {
return Math.sqrt((Math.PI * ((n / k) * 2.0)));
}
def code(k, n): return math.sqrt((math.pi * ((n / k) * 2.0)))
function code(k, n) return sqrt(Float64(pi * Float64(Float64(n / k) * 2.0))) end
function tmp = code(k, n) tmp = sqrt((pi * ((n / k) * 2.0))); end
code[k_, n_] := N[Sqrt[N[(Pi * N[(N[(n / k), $MachinePrecision] * 2.0), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]
\begin{array}{l}
\\
\sqrt{\pi \cdot \left(\frac{n}{k} \cdot 2\right)}
\end{array}
Initial program 99.5%
Taylor expanded in k around 0
sqrt-unprodN/A
lower-sqrt.f64N/A
lower-*.f64N/A
lower-/.f64N/A
*-commutativeN/A
lower-*.f64N/A
lift-PI.f6437.7
Applied rewrites37.7%
lift-/.f64N/A
lift-PI.f64N/A
lift-*.f64N/A
associate-/l*N/A
lower-*.f64N/A
lift-PI.f64N/A
lower-/.f6437.7
Applied rewrites37.7%
lift-*.f64N/A
lift-PI.f64N/A
lift-*.f64N/A
associate-*l*N/A
lower-*.f64N/A
lift-PI.f64N/A
lower-*.f6437.7
Applied rewrites37.7%
herbie shell --seed 2025064
(FPCore (k n)
:name "Migdal et al, Equation (51)"
:precision binary64
(* (/ 1.0 (sqrt k)) (pow (* (* 2.0 PI) n) (/ (- 1.0 k) 2.0))))