
(FPCore (u1 u2) :precision binary64 (+ (* (* (/ 1.0 6.0) (pow (* -2.0 (log u1)) 0.5)) (cos (* (* 2.0 PI) u2))) 0.5))
double code(double u1, double u2) {
return (((1.0 / 6.0) * pow((-2.0 * log(u1)), 0.5)) * cos(((2.0 * ((double) M_PI)) * u2))) + 0.5;
}
public static double code(double u1, double u2) {
return (((1.0 / 6.0) * Math.pow((-2.0 * Math.log(u1)), 0.5)) * Math.cos(((2.0 * Math.PI) * u2))) + 0.5;
}
def code(u1, u2): return (((1.0 / 6.0) * math.pow((-2.0 * math.log(u1)), 0.5)) * math.cos(((2.0 * math.pi) * u2))) + 0.5
function code(u1, u2) return Float64(Float64(Float64(Float64(1.0 / 6.0) * (Float64(-2.0 * log(u1)) ^ 0.5)) * cos(Float64(Float64(2.0 * pi) * u2))) + 0.5) end
function tmp = code(u1, u2) tmp = (((1.0 / 6.0) * ((-2.0 * log(u1)) ^ 0.5)) * cos(((2.0 * pi) * u2))) + 0.5; end
code[u1_, u2_] := N[(N[(N[(N[(1.0 / 6.0), $MachinePrecision] * N[Power[N[(-2.0 * N[Log[u1], $MachinePrecision]), $MachinePrecision], 0.5], $MachinePrecision]), $MachinePrecision] * N[Cos[N[(N[(2.0 * Pi), $MachinePrecision] * u2), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] + 0.5), $MachinePrecision]
\begin{array}{l}
\\
\left(\frac{1}{6} \cdot {\left(-2 \cdot \log u1\right)}^{0.5}\right) \cdot \cos \left(\left(2 \cdot \pi\right) \cdot u2\right) + 0.5
\end{array}
Herbie found 3 alternatives:
| Alternative | Accuracy | Speedup |
|---|
(FPCore (u1 u2) :precision binary64 (+ (* (* (/ 1.0 6.0) (pow (* -2.0 (log u1)) 0.5)) (cos (* (* 2.0 PI) u2))) 0.5))
double code(double u1, double u2) {
return (((1.0 / 6.0) * pow((-2.0 * log(u1)), 0.5)) * cos(((2.0 * ((double) M_PI)) * u2))) + 0.5;
}
public static double code(double u1, double u2) {
return (((1.0 / 6.0) * Math.pow((-2.0 * Math.log(u1)), 0.5)) * Math.cos(((2.0 * Math.PI) * u2))) + 0.5;
}
def code(u1, u2): return (((1.0 / 6.0) * math.pow((-2.0 * math.log(u1)), 0.5)) * math.cos(((2.0 * math.pi) * u2))) + 0.5
function code(u1, u2) return Float64(Float64(Float64(Float64(1.0 / 6.0) * (Float64(-2.0 * log(u1)) ^ 0.5)) * cos(Float64(Float64(2.0 * pi) * u2))) + 0.5) end
function tmp = code(u1, u2) tmp = (((1.0 / 6.0) * ((-2.0 * log(u1)) ^ 0.5)) * cos(((2.0 * pi) * u2))) + 0.5; end
code[u1_, u2_] := N[(N[(N[(N[(1.0 / 6.0), $MachinePrecision] * N[Power[N[(-2.0 * N[Log[u1], $MachinePrecision]), $MachinePrecision], 0.5], $MachinePrecision]), $MachinePrecision] * N[Cos[N[(N[(2.0 * Pi), $MachinePrecision] * u2), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] + 0.5), $MachinePrecision]
\begin{array}{l}
\\
\left(\frac{1}{6} \cdot {\left(-2 \cdot \log u1\right)}^{0.5}\right) \cdot \cos \left(\left(2 \cdot \pi\right) \cdot u2\right) + 0.5
\end{array}
(FPCore (u1 u2) :precision binary64 (fma (* (cos (* u2 (+ PI PI))) (sqrt (* (log u1) -2.0))) 0.16666666666666666 0.5))
double code(double u1, double u2) {
return fma((cos((u2 * (((double) M_PI) + ((double) M_PI)))) * sqrt((log(u1) * -2.0))), 0.16666666666666666, 0.5);
}
function code(u1, u2) return fma(Float64(cos(Float64(u2 * Float64(pi + pi))) * sqrt(Float64(log(u1) * -2.0))), 0.16666666666666666, 0.5) end
code[u1_, u2_] := N[(N[(N[Cos[N[(u2 * N[(Pi + Pi), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] * N[Sqrt[N[(N[Log[u1], $MachinePrecision] * -2.0), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] * 0.16666666666666666 + 0.5), $MachinePrecision]
\begin{array}{l}
\\
\mathsf{fma}\left(\cos \left(u2 \cdot \left(\pi + \pi\right)\right) \cdot \sqrt{\log u1 \cdot -2}, 0.16666666666666666, 0.5\right)
\end{array}
Initial program 99.4%
lift-+.f64N/A
lift-*.f64N/A
lift-*.f64N/A
associate-*l*N/A
*-commutativeN/A
lower-fma.f64N/A
Applied rewrites99.4%
(FPCore (u1 u2) :precision binary64 (let* ((t_0 (sqrt (* -2.0 (log u1))))) (fma (/ 0.5 t_0) t_0 (* t_0 0.16666666666666666))))
double code(double u1, double u2) {
double t_0 = sqrt((-2.0 * log(u1)));
return fma((0.5 / t_0), t_0, (t_0 * 0.16666666666666666));
}
function code(u1, u2) t_0 = sqrt(Float64(-2.0 * log(u1))) return fma(Float64(0.5 / t_0), t_0, Float64(t_0 * 0.16666666666666666)) end
code[u1_, u2_] := Block[{t$95$0 = N[Sqrt[N[(-2.0 * N[Log[u1], $MachinePrecision]), $MachinePrecision]], $MachinePrecision]}, N[(N[(0.5 / t$95$0), $MachinePrecision] * t$95$0 + N[(t$95$0 * 0.16666666666666666), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \sqrt{-2 \cdot \log u1}\\
\mathsf{fma}\left(\frac{0.5}{t\_0}, t\_0, t\_0 \cdot 0.16666666666666666\right)
\end{array}
\end{array}
Initial program 99.4%
Taylor expanded in u2 around 0
metadata-evalN/A
lower-+.f64N/A
lower-*.f64N/A
metadata-evalN/A
lower-sqrt.f64N/A
lower-*.f64N/A
lower-log.f6497.9
Applied rewrites97.9%
lift-*.f64N/A
*-commutativeN/A
lift-sqrt.f64N/A
pow1/2N/A
pow-to-expN/A
lift-*.f64N/A
*-commutativeN/A
lift-*.f64N/A
pow-to-expN/A
pow1/2N/A
lift-sqrt.f64N/A
*-commutativeN/A
lift-sqrt.f64N/A
pow1/2N/A
metadata-evalN/A
pow-flipN/A
lift-pow.f64N/A
mult-flip-revN/A
lower-/.f6497.9
lift-pow.f64N/A
metadata-evalN/A
pow-negN/A
lower-unsound-pow.f32N/A
lower-pow.f32N/A
pow1/2N/A
lift-sqrt.f64N/A
Applied rewrites97.8%
lift-+.f64N/A
lift-/.f64N/A
add-to-fractionN/A
lift-/.f64N/A
lift-*.f64N/A
*-commutativeN/A
lift-*.f64N/A
mult-flipN/A
lift-/.f64N/A
metadata-evalN/A
sub-flipN/A
lift--.f64N/A
mult-flipN/A
lift-/.f64N/A
lift-*.f64N/A
*-commutativeN/A
lift-*.f64N/A
Applied rewrites97.9%
(FPCore (u1 u2) :precision binary64 (fma (sqrt (* -2.0 (log u1))) 0.16666666666666666 0.5))
double code(double u1, double u2) {
return fma(sqrt((-2.0 * log(u1))), 0.16666666666666666, 0.5);
}
function code(u1, u2) return fma(sqrt(Float64(-2.0 * log(u1))), 0.16666666666666666, 0.5) end
code[u1_, u2_] := N[(N[Sqrt[N[(-2.0 * N[Log[u1], $MachinePrecision]), $MachinePrecision]], $MachinePrecision] * 0.16666666666666666 + 0.5), $MachinePrecision]
\begin{array}{l}
\\
\mathsf{fma}\left(\sqrt{-2 \cdot \log u1}, 0.16666666666666666, 0.5\right)
\end{array}
Initial program 99.4%
Taylor expanded in u2 around 0
metadata-evalN/A
lower-+.f64N/A
lower-*.f64N/A
metadata-evalN/A
lower-sqrt.f64N/A
lower-*.f64N/A
lower-log.f6497.9
Applied rewrites97.9%
lift-+.f64N/A
+-commutativeN/A
lift-*.f64N/A
*-commutativeN/A
lift-sqrt.f64N/A
pow1/2N/A
pow-to-expN/A
lift-*.f64N/A
*-commutativeN/A
lift-*.f64N/A
pow-to-expN/A
pow1/2N/A
lift-sqrt.f64N/A
lower-fma.f6497.9
Applied rewrites97.9%
herbie shell --seed 2025154
(FPCore (u1 u2)
:name "normal distribution"
:precision binary64
:pre (and (and (<= 0.0 u1) (<= u1 1.0)) (and (<= 0.0 u2) (<= u2 1.0)))
(+ (* (* (/ 1.0 6.0) (pow (* -2.0 (log u1)) 0.5)) (cos (* (* 2.0 PI) u2))) 0.5))