
(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 (* n (+ PI PI)) (fma -0.5 k 0.5)) (sqrt k)))
double code(double k, double n) {
return pow((n * (((double) M_PI) + ((double) M_PI))), fma(-0.5, k, 0.5)) / sqrt(k);
}
function code(k, n) return Float64((Float64(n * Float64(pi + pi)) ^ fma(-0.5, k, 0.5)) / sqrt(k)) end
code[k_, n_] := N[(N[Power[N[(n * N[(Pi + Pi), $MachinePrecision]), $MachinePrecision], N[(-0.5 * k + 0.5), $MachinePrecision]], $MachinePrecision] / N[Sqrt[k], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{{\left(n \cdot \left(\pi + \pi\right)\right)}^{\left(\mathsf{fma}\left(-0.5, k, 0.5\right)\right)}}{\sqrt{k}}
\end{array}
Initial program 99.2%
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 rewrites99.3%
Taylor expanded in k around 0
+-commutativeN/A
lower-fma.f6499.3
Applied rewrites99.3%
lift-*.f64N/A
*-lft-identity99.3
lift-*.f64N/A
*-commutativeN/A
lift-*.f6499.3
Applied rewrites99.3%
lift-PI.f64N/A
lift-*.f64N/A
*-commutativeN/A
count-2-revN/A
lift-+.f64N/A
lift-PI.f64N/A
lift-PI.f6499.3
Applied rewrites99.3%
(FPCore (k n) :precision binary64 (if (<= (* (/ 1.0 (sqrt k)) (pow (* (* 2.0 PI) n) (/ (- 1.0 k) 2.0))) 2e+148) (sqrt (* (* n (/ PI k)) 2.0)) (/ (sqrt (* (* 2.0 k) (* PI n))) 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))) <= 2e+148) {
tmp = sqrt(((n * (((double) M_PI) / k)) * 2.0));
} else {
tmp = sqrt(((2.0 * k) * (((double) M_PI) * n))) / 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))) <= 2e+148) {
tmp = Math.sqrt(((n * (Math.PI / k)) * 2.0));
} else {
tmp = Math.sqrt(((2.0 * k) * (Math.PI * n))) / 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))) <= 2e+148: tmp = math.sqrt(((n * (math.pi / k)) * 2.0)) else: tmp = math.sqrt(((2.0 * k) * (math.pi * n))) / 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))) <= 2e+148) tmp = sqrt(Float64(Float64(n * Float64(pi / k)) * 2.0)); else tmp = Float64(sqrt(Float64(Float64(2.0 * k) * Float64(pi * n))) / 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))) <= 2e+148) tmp = sqrt(((n * (pi / k)) * 2.0)); else tmp = sqrt(((2.0 * k) * (pi * n))) / 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], 2e+148], N[Sqrt[N[(N[(n * N[(Pi / k), $MachinePrecision]), $MachinePrecision] * 2.0), $MachinePrecision]], $MachinePrecision], N[(N[Sqrt[N[(N[(2.0 * k), $MachinePrecision] * N[(Pi * n), $MachinePrecision]), $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 2 \cdot 10^{+148}:\\
\;\;\;\;\sqrt{\left(n \cdot \frac{\pi}{k}\right) \cdot 2}\\
\mathbf{else}:\\
\;\;\;\;\frac{\sqrt{\left(2 \cdot k\right) \cdot \left(\pi \cdot n\right)}}{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)))) < 2.0000000000000001e148Initial program 99.0%
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.f6466.3
Applied rewrites66.3%
lift-/.f64N/A
lift-PI.f64N/A
lift-*.f64N/A
*-commutativeN/A
associate-/l*N/A
lower-*.f64N/A
lower-/.f64N/A
lift-PI.f6466.3
Applied rewrites66.3%
if 2.0000000000000001e148 < (*.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 99.7%
Taylor expanded in k around 0
lower-/.f64N/A
Applied rewrites81.8%
Taylor expanded in k around 0
*-commutativeN/A
lift-*.f64N/A
lift-PI.f64N/A
*-commutativeN/A
lift-*.f64N/A
sqrt-prodN/A
lift-*.f64N/A
lift-sqrt.f6438.1
lift-*.f64N/A
*-commutativeN/A
lift-*.f64N/A
*-commutativeN/A
lift-PI.f64N/A
lift-*.f64N/A
*-commutativeN/A
associate-*r*N/A
Applied rewrites38.1%
(FPCore (k n) :precision binary64 (/ (sqrt (* n (* PI 2.0))) (sqrt k)))
double code(double k, double n) {
return sqrt((n * (((double) M_PI) * 2.0))) / sqrt(k);
}
public static double code(double k, double n) {
return Math.sqrt((n * (Math.PI * 2.0))) / Math.sqrt(k);
}
def code(k, n): return math.sqrt((n * (math.pi * 2.0))) / math.sqrt(k)
function code(k, n) return Float64(sqrt(Float64(n * Float64(pi * 2.0))) / sqrt(k)) end
function tmp = code(k, n) tmp = sqrt((n * (pi * 2.0))) / sqrt(k); end
code[k_, n_] := N[(N[Sqrt[N[(n * N[(Pi * 2.0), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] / N[Sqrt[k], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{\sqrt{n \cdot \left(\pi \cdot 2\right)}}{\sqrt{k}}
\end{array}
Initial program 99.2%
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 rewrites99.3%
Taylor expanded in k around 0
*-lft-identityN/A
*-commutativeN/A
sqrt-unprodN/A
*-commutativeN/A
*-commutativeN/A
associate-*l*N/A
*-commutativeN/A
lift-*.f64N/A
lift-PI.f64N/A
lift-*.f64N/A
lift-sqrt.f6456.0
lift-*.f64N/A
*-commutativeN/A
lower-*.f6456.0
Applied rewrites56.0%
(FPCore (k n) :precision binary64 (sqrt (* (* n (/ PI k)) 2.0)))
double code(double k, double n) {
return sqrt(((n * (((double) M_PI) / k)) * 2.0));
}
public static double code(double k, double n) {
return Math.sqrt(((n * (Math.PI / k)) * 2.0));
}
def code(k, n): return math.sqrt(((n * (math.pi / k)) * 2.0))
function code(k, n) return sqrt(Float64(Float64(n * Float64(pi / k)) * 2.0)) end
function tmp = code(k, n) tmp = sqrt(((n * (pi / k)) * 2.0)); end
code[k_, n_] := N[Sqrt[N[(N[(n * N[(Pi / k), $MachinePrecision]), $MachinePrecision] * 2.0), $MachinePrecision]], $MachinePrecision]
\begin{array}{l}
\\
\sqrt{\left(n \cdot \frac{\pi}{k}\right) \cdot 2}
\end{array}
Initial program 99.2%
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.f6444.0
Applied rewrites44.0%
lift-/.f64N/A
lift-PI.f64N/A
lift-*.f64N/A
*-commutativeN/A
associate-/l*N/A
lower-*.f64N/A
lower-/.f64N/A
lift-PI.f6444.1
Applied rewrites44.1%
(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 99.2%
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.f6444.0
Applied rewrites44.0%
lift-/.f64N/A
lift-PI.f64N/A
lift-*.f64N/A
associate-/l*N/A
lower-*.f64N/A
lift-PI.f64N/A
lower-/.f6444.1
Applied rewrites44.1%
lift-*.f64N/A
lift-PI.f64N/A
lift-*.f64N/A
associate-*l*N/A
lower-*.f64N/A
lift-PI.f64N/A
lower-*.f6444.1
Applied rewrites44.1%
herbie shell --seed 2025072
(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))))