
(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}
Herbie found 4 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 n) 2.0) (fma -0.5 k 0.5)) (sqrt k)))
double code(double k, double n) {
return pow(((((double) M_PI) * n) * 2.0), fma(-0.5, k, 0.5)) / sqrt(k);
}
function code(k, n) return Float64((Float64(Float64(pi * n) * 2.0) ^ fma(-0.5, k, 0.5)) / sqrt(k)) end
code[k_, n_] := N[(N[Power[N[(N[(Pi * n), $MachinePrecision] * 2.0), $MachinePrecision], N[(-0.5 * k + 0.5), $MachinePrecision]], $MachinePrecision] / N[Sqrt[k], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{{\left(\left(\pi \cdot n\right) \cdot 2\right)}^{\left(\mathsf{fma}\left(-0.5, k, 0.5\right)\right)}}{\sqrt{k}}
\end{array}
Initial program 99.5%
Taylor expanded in k around 0
+-commutativeN/A
lower-fma.f6499.5
Applied rewrites99.5%
lift-*.f64N/A
lift-/.f64N/A
lift-sqrt.f64N/A
associate-*l/N/A
lower-/.f64N/A
lower-*.f64N/A
lift-*.f64N/A
lift-PI.f64N/A
lift-*.f64N/A
associate-*l*N/A
*-commutativeN/A
associate-*r*N/A
lower-*.f64N/A
lower-*.f64N/A
lift-PI.f64N/A
lift-sqrt.f6499.6
Applied rewrites99.6%
lift-*.f64N/A
*-lft-identity99.6
lift-*.f64N/A
lift-PI.f64N/A
lift-*.f64N/A
associate-*r*N/A
*-commutativeN/A
lower-*.f64N/A
*-commutativeN/A
lower-*.f64N/A
lift-PI.f6499.6
Applied rewrites99.6%
(FPCore (k n) :precision binary64 (if (<= k 1.0) (/ (sqrt (* (* 2.0 n) PI)) (sqrt k)) (/ (pow (* (* PI n) 2.0) (* -0.5 k)) (sqrt k))))
double code(double k, double n) {
double tmp;
if (k <= 1.0) {
tmp = sqrt(((2.0 * n) * ((double) M_PI))) / sqrt(k);
} else {
tmp = pow(((((double) M_PI) * n) * 2.0), (-0.5 * k)) / sqrt(k);
}
return tmp;
}
public static double code(double k, double n) {
double tmp;
if (k <= 1.0) {
tmp = Math.sqrt(((2.0 * n) * Math.PI)) / Math.sqrt(k);
} else {
tmp = Math.pow(((Math.PI * n) * 2.0), (-0.5 * k)) / Math.sqrt(k);
}
return tmp;
}
def code(k, n): tmp = 0 if k <= 1.0: tmp = math.sqrt(((2.0 * n) * math.pi)) / math.sqrt(k) else: tmp = math.pow(((math.pi * n) * 2.0), (-0.5 * k)) / math.sqrt(k) return tmp
function code(k, n) tmp = 0.0 if (k <= 1.0) tmp = Float64(sqrt(Float64(Float64(2.0 * n) * pi)) / sqrt(k)); else tmp = Float64((Float64(Float64(pi * n) * 2.0) ^ Float64(-0.5 * k)) / sqrt(k)); end return tmp end
function tmp_2 = code(k, n) tmp = 0.0; if (k <= 1.0) tmp = sqrt(((2.0 * n) * pi)) / sqrt(k); else tmp = (((pi * n) * 2.0) ^ (-0.5 * k)) / sqrt(k); end tmp_2 = tmp; end
code[k_, n_] := If[LessEqual[k, 1.0], N[(N[Sqrt[N[(N[(2.0 * n), $MachinePrecision] * Pi), $MachinePrecision]], $MachinePrecision] / N[Sqrt[k], $MachinePrecision]), $MachinePrecision], N[(N[Power[N[(N[(Pi * n), $MachinePrecision] * 2.0), $MachinePrecision], N[(-0.5 * k), $MachinePrecision]], $MachinePrecision] / N[Sqrt[k], $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;k \leq 1:\\
\;\;\;\;\frac{\sqrt{\left(2 \cdot n\right) \cdot \pi}}{\sqrt{k}}\\
\mathbf{else}:\\
\;\;\;\;\frac{{\left(\left(\pi \cdot n\right) \cdot 2\right)}^{\left(-0.5 \cdot k\right)}}{\sqrt{k}}\\
\end{array}
\end{array}
if k < 1Initial program 99.0%
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 rewrites99.1%
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 rewrites97.0%
if 1 < k Initial program 100.0%
Taylor expanded in k around 0
+-commutativeN/A
lower-fma.f64100.0
Applied rewrites100.0%
lift-*.f64N/A
lift-/.f64N/A
lift-sqrt.f64N/A
associate-*l/N/A
lower-/.f64N/A
lower-*.f64N/A
lift-*.f64N/A
lift-PI.f64N/A
lift-*.f64N/A
associate-*l*N/A
*-commutativeN/A
associate-*r*N/A
lower-*.f64N/A
lower-*.f64N/A
lift-PI.f64N/A
lift-sqrt.f64100.0
Applied rewrites100.0%
lift-*.f64N/A
*-lft-identity100.0
lift-*.f64N/A
lift-PI.f64N/A
lift-*.f64N/A
associate-*r*N/A
*-commutativeN/A
lower-*.f64N/A
*-commutativeN/A
lower-*.f64N/A
lift-PI.f64100.0
Applied rewrites100.0%
Taylor expanded in k around inf
lower-*.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 rewrites49.6%
(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 2025086
(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))))