
(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 6 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 2.0))) (* (pow (pow (log u1) 2.0) 0.25) (pow 4.0 0.25))) 0.16666666666666666 0.5))
double code(double u1, double u2) {
return fma((cos((u2 * (((double) M_PI) * 2.0))) * (pow(pow(log(u1), 2.0), 0.25) * pow(4.0, 0.25))), 0.16666666666666666, 0.5);
}
function code(u1, u2) return fma(Float64(cos(Float64(u2 * Float64(pi * 2.0))) * Float64(((log(u1) ^ 2.0) ^ 0.25) * (4.0 ^ 0.25))), 0.16666666666666666, 0.5) end
code[u1_, u2_] := N[(N[(N[Cos[N[(u2 * N[(Pi * 2.0), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] * N[(N[Power[N[Power[N[Log[u1], $MachinePrecision], 2.0], $MachinePrecision], 0.25], $MachinePrecision] * N[Power[4.0, 0.25], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * 0.16666666666666666 + 0.5), $MachinePrecision]
\begin{array}{l}
\\
\mathsf{fma}\left(\cos \left(u2 \cdot \left(\pi \cdot 2\right)\right) \cdot \left({\left({\log u1}^{2}\right)}^{0.25} \cdot {4}^{0.25}\right), 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%
lift-sqrt.f64N/A
pow1/2N/A
metadata-evalN/A
pow-powN/A
pow2N/A
lift-*.f64N/A
lift-*.f64N/A
swap-sqrN/A
unpow-prod-downN/A
lower-*.f64N/A
lower-pow.f64N/A
pow2N/A
lower-pow.f64N/A
lower-pow.f64N/A
metadata-eval99.5
Applied rewrites99.5%
(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%
lift-*.f64N/A
*-commutativeN/A
count-2-revN/A
lower-+.f6499.4
Applied rewrites99.4%
(FPCore (u1 u2) :precision binary64 (fma (* (cos (* u2 (+ PI PI))) 0.16666666666666666) (sqrt (* (log u1) -2.0)) 0.5))
double code(double u1, double u2) {
return fma((cos((u2 * (((double) M_PI) + ((double) M_PI)))) * 0.16666666666666666), sqrt((log(u1) * -2.0)), 0.5);
}
function code(u1, u2) return fma(Float64(cos(Float64(u2 * Float64(pi + pi))) * 0.16666666666666666), sqrt(Float64(log(u1) * -2.0)), 0.5) end
code[u1_, u2_] := N[(N[(N[Cos[N[(u2 * N[(Pi + Pi), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] * 0.16666666666666666), $MachinePrecision] * N[Sqrt[N[(N[Log[u1], $MachinePrecision] * -2.0), $MachinePrecision]], $MachinePrecision] + 0.5), $MachinePrecision]
\begin{array}{l}
\\
\mathsf{fma}\left(\cos \left(u2 \cdot \left(\pi + \pi\right)\right) \cdot 0.16666666666666666, \sqrt{\log u1 \cdot -2}, 0.5\right)
\end{array}
Initial program 99.4%
lift-+.f64N/A
lift-*.f64N/A
*-commutativeN/A
lift-*.f64N/A
associate-*r*N/A
lower-fma.f64N/A
Applied rewrites99.4%
lift-*.f64N/A
*-commutativeN/A
count-2-revN/A
lower-+.f6499.4
Applied rewrites99.4%
(FPCore (u1 u2) :precision binary64 (fma (* (fma (* u2 u2) -2.0 1.0) 0.16666666666666666) (sqrt (* (log u1) -2.0)) 0.5))
double code(double u1, double u2) {
return fma((fma((u2 * u2), -2.0, 1.0) * 0.16666666666666666), sqrt((log(u1) * -2.0)), 0.5);
}
function code(u1, u2) return fma(Float64(fma(Float64(u2 * u2), -2.0, 1.0) * 0.16666666666666666), sqrt(Float64(log(u1) * -2.0)), 0.5) end
code[u1_, u2_] := N[(N[(N[(N[(u2 * u2), $MachinePrecision] * -2.0 + 1.0), $MachinePrecision] * 0.16666666666666666), $MachinePrecision] * N[Sqrt[N[(N[Log[u1], $MachinePrecision] * -2.0), $MachinePrecision]], $MachinePrecision] + 0.5), $MachinePrecision]
\begin{array}{l}
\\
\mathsf{fma}\left(\mathsf{fma}\left(u2 \cdot u2, -2, 1\right) \cdot 0.16666666666666666, \sqrt{\log u1 \cdot -2}, 0.5\right)
\end{array}
Initial program 99.4%
lift-+.f64N/A
lift-*.f64N/A
*-commutativeN/A
lift-*.f64N/A
associate-*r*N/A
lower-fma.f64N/A
Applied rewrites99.4%
lift-*.f64N/A
*-commutativeN/A
count-2-revN/A
lower-+.f6499.4
Applied rewrites99.4%
Applied rewrites98.2%
Taylor expanded in u2 around 0
+-commutativeN/A
*-commutativeN/A
lower-fma.f64N/A
unpow2N/A
lower-*.f6498.2
Applied rewrites98.2%
(FPCore (u1 u2) :precision binary64 (fma (fma (* u2 u2) -0.3333333333333333 0.16666666666666666) (sqrt (* (log u1) -2.0)) 0.5))
double code(double u1, double u2) {
return fma(fma((u2 * u2), -0.3333333333333333, 0.16666666666666666), sqrt((log(u1) * -2.0)), 0.5);
}
function code(u1, u2) return fma(fma(Float64(u2 * u2), -0.3333333333333333, 0.16666666666666666), sqrt(Float64(log(u1) * -2.0)), 0.5) end
code[u1_, u2_] := N[(N[(N[(u2 * u2), $MachinePrecision] * -0.3333333333333333 + 0.16666666666666666), $MachinePrecision] * N[Sqrt[N[(N[Log[u1], $MachinePrecision] * -2.0), $MachinePrecision]], $MachinePrecision] + 0.5), $MachinePrecision]
\begin{array}{l}
\\
\mathsf{fma}\left(\mathsf{fma}\left(u2 \cdot u2, -0.3333333333333333, 0.16666666666666666\right), \sqrt{\log u1 \cdot -2}, 0.5\right)
\end{array}
Initial program 99.4%
lift-+.f64N/A
lift-*.f64N/A
*-commutativeN/A
lift-*.f64N/A
associate-*r*N/A
lower-fma.f64N/A
Applied rewrites99.4%
lift-*.f64N/A
*-commutativeN/A
count-2-revN/A
lower-+.f6499.4
Applied rewrites99.4%
Applied rewrites98.2%
Taylor expanded in u2 around 0
+-commutativeN/A
*-commutativeN/A
lower-fma.f64N/A
unpow2N/A
lower-*.f6498.2
Applied rewrites98.2%
(FPCore (u1 u2) :precision binary64 (fma (sqrt (* (log u1) -2.0)) 0.16666666666666666 0.5))
double code(double u1, double u2) {
return fma(sqrt((log(u1) * -2.0)), 0.16666666666666666, 0.5);
}
function code(u1, u2) return fma(sqrt(Float64(log(u1) * -2.0)), 0.16666666666666666, 0.5) end
code[u1_, u2_] := N[(N[Sqrt[N[(N[Log[u1], $MachinePrecision] * -2.0), $MachinePrecision]], $MachinePrecision] * 0.16666666666666666 + 0.5), $MachinePrecision]
\begin{array}{l}
\\
\mathsf{fma}\left(\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%
lift-*.f64N/A
*-commutativeN/A
count-2-revN/A
lower-+.f6499.4
Applied rewrites99.4%
Taylor expanded in u2 around 0
sqrt-prodN/A
lift-log.f64N/A
lift-*.f64N/A
lift-sqrt.f6498.2
Applied rewrites98.2%
herbie shell --seed 2025106
(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))