
(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}
Sampling outcomes in binary64 precision:
Herbie found 8 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 (* (* PI u2) 2.0)) (* (sqrt 2.0) 0.16666666666666666)) (sqrt (- (log u1))) 0.5))
double code(double u1, double u2) {
return fma((cos(((((double) M_PI) * u2) * 2.0)) * (sqrt(2.0) * 0.16666666666666666)), sqrt(-log(u1)), 0.5);
}
function code(u1, u2) return fma(Float64(cos(Float64(Float64(pi * u2) * 2.0)) * Float64(sqrt(2.0) * 0.16666666666666666)), sqrt(Float64(-log(u1))), 0.5) end
code[u1_, u2_] := N[(N[(N[Cos[N[(N[(Pi * u2), $MachinePrecision] * 2.0), $MachinePrecision]], $MachinePrecision] * N[(N[Sqrt[2.0], $MachinePrecision] * 0.16666666666666666), $MachinePrecision]), $MachinePrecision] * N[Sqrt[(-N[Log[u1], $MachinePrecision])], $MachinePrecision] + 0.5), $MachinePrecision]
\begin{array}{l}
\\
\mathsf{fma}\left(\cos \left(\left(\pi \cdot u2\right) \cdot 2\right) \cdot \left(\sqrt{2} \cdot 0.16666666666666666\right), \sqrt{-\log u1}, 0.5\right)
\end{array}
Initial program 99.4%
lift-pow.f64N/A
pow-to-expN/A
*-commutativeN/A
exp-prodN/A
lower-pow.f64N/A
lower-exp.f64N/A
lower-log.f6498.8
lift-*.f64N/A
*-commutativeN/A
lower-*.f6498.8
Applied rewrites98.8%
Taylor expanded in u1 around inf
+-commutativeN/A
associate-*r*N/A
lower-fma.f64N/A
Applied rewrites99.6%
Final simplification99.6%
(FPCore (u1 u2) :precision binary64 (fma (* (cos (* (* PI 2.0) u2)) 0.16666666666666666) (sqrt (* (log u1) -2.0)) 0.5))
double code(double u1, double u2) {
return fma((cos(((((double) M_PI) * 2.0) * u2)) * 0.16666666666666666), sqrt((log(u1) * -2.0)), 0.5);
}
function code(u1, u2) return fma(Float64(cos(Float64(Float64(pi * 2.0) * u2)) * 0.16666666666666666), sqrt(Float64(log(u1) * -2.0)), 0.5) end
code[u1_, u2_] := N[(N[(N[Cos[N[(N[(Pi * 2.0), $MachinePrecision] * u2), $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(\left(\pi \cdot 2\right) \cdot u2\right) \cdot 0.16666666666666666, \sqrt{\log u1 \cdot -2}, 0.5\right)
\end{array}
Initial program 99.4%
lift-+.f64N/A
lift-*.f64N/A
lift-*.f64N/A
associate-*l*N/A
*-commutativeN/A
associate-*r*N/A
lower-fma.f64N/A
Applied rewrites99.4%
Final simplification99.4%
(FPCore (u1 u2)
:precision binary64
(let* ((t_0 (* (* u2 u2) -0.3333333333333333)))
(fma
(/
(fma (* (* PI PI) (* PI PI)) (* t_0 t_0) -0.027777777777777776)
(fma (* PI PI) t_0 -0.16666666666666666))
(sqrt (* (log u1) -2.0))
0.5)))
double code(double u1, double u2) {
double t_0 = (u2 * u2) * -0.3333333333333333;
return fma((fma(((((double) M_PI) * ((double) M_PI)) * (((double) M_PI) * ((double) M_PI))), (t_0 * t_0), -0.027777777777777776) / fma((((double) M_PI) * ((double) M_PI)), t_0, -0.16666666666666666)), sqrt((log(u1) * -2.0)), 0.5);
}
function code(u1, u2) t_0 = Float64(Float64(u2 * u2) * -0.3333333333333333) return fma(Float64(fma(Float64(Float64(pi * pi) * Float64(pi * pi)), Float64(t_0 * t_0), -0.027777777777777776) / fma(Float64(pi * pi), t_0, -0.16666666666666666)), sqrt(Float64(log(u1) * -2.0)), 0.5) end
code[u1_, u2_] := Block[{t$95$0 = N[(N[(u2 * u2), $MachinePrecision] * -0.3333333333333333), $MachinePrecision]}, N[(N[(N[(N[(N[(Pi * Pi), $MachinePrecision] * N[(Pi * Pi), $MachinePrecision]), $MachinePrecision] * N[(t$95$0 * t$95$0), $MachinePrecision] + -0.027777777777777776), $MachinePrecision] / N[(N[(Pi * Pi), $MachinePrecision] * t$95$0 + -0.16666666666666666), $MachinePrecision]), $MachinePrecision] * N[Sqrt[N[(N[Log[u1], $MachinePrecision] * -2.0), $MachinePrecision]], $MachinePrecision] + 0.5), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \left(u2 \cdot u2\right) \cdot -0.3333333333333333\\
\mathsf{fma}\left(\frac{\mathsf{fma}\left(\left(\pi \cdot \pi\right) \cdot \left(\pi \cdot \pi\right), t\_0 \cdot t\_0, -0.027777777777777776\right)}{\mathsf{fma}\left(\pi \cdot \pi, t\_0, -0.16666666666666666\right)}, \sqrt{\log u1 \cdot -2}, 0.5\right)
\end{array}
\end{array}
Initial program 99.4%
lift-+.f64N/A
lift-*.f64N/A
lift-*.f64N/A
associate-*l*N/A
*-commutativeN/A
associate-*r*N/A
lower-fma.f64N/A
Applied rewrites99.4%
Taylor expanded in u2 around 0
+-commutativeN/A
associate-*r*N/A
lower-fma.f64N/A
*-commutativeN/A
lower-*.f64N/A
unpow2N/A
lower-*.f64N/A
unpow2N/A
lower-*.f64N/A
lower-PI.f64N/A
lower-PI.f6498.9
Applied rewrites98.9%
Applied rewrites98.9%
Final simplification98.9%
(FPCore (u1 u2) :precision binary64 (fma (* (fma (* (* PI PI) -2.0) (* u2 u2) 1.0) 0.16666666666666666) (sqrt (* (log u1) -2.0)) 0.5))
double code(double u1, double u2) {
return fma((fma(((((double) M_PI) * ((double) M_PI)) * -2.0), (u2 * u2), 1.0) * 0.16666666666666666), sqrt((log(u1) * -2.0)), 0.5);
}
function code(u1, u2) return fma(Float64(fma(Float64(Float64(pi * pi) * -2.0), Float64(u2 * u2), 1.0) * 0.16666666666666666), sqrt(Float64(log(u1) * -2.0)), 0.5) end
code[u1_, u2_] := N[(N[(N[(N[(N[(Pi * Pi), $MachinePrecision] * -2.0), $MachinePrecision] * N[(u2 * u2), $MachinePrecision] + 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(\left(\pi \cdot \pi\right) \cdot -2, u2 \cdot u2, 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
lift-*.f64N/A
associate-*l*N/A
*-commutativeN/A
associate-*r*N/A
lower-fma.f64N/A
Applied rewrites99.4%
Taylor expanded in u2 around 0
+-commutativeN/A
rem-square-sqrtN/A
unpow2N/A
*-commutativeN/A
associate-*r*N/A
unpow2N/A
rem-square-sqrtN/A
lower-fma.f64N/A
*-commutativeN/A
rem-square-sqrtN/A
unpow2N/A
lower-*.f64N/A
unpow2N/A
lower-*.f64N/A
lower-PI.f64N/A
lower-PI.f64N/A
unpow2N/A
rem-square-sqrtN/A
unpow2N/A
lower-*.f6498.9
Applied rewrites98.9%
(FPCore (u1 u2) :precision binary64 (fma (fma (* (* u2 u2) -0.3333333333333333) (* PI PI) 0.16666666666666666) (sqrt (* (log u1) -2.0)) 0.5))
double code(double u1, double u2) {
return fma(fma(((u2 * u2) * -0.3333333333333333), (((double) M_PI) * ((double) M_PI)), 0.16666666666666666), sqrt((log(u1) * -2.0)), 0.5);
}
function code(u1, u2) return fma(fma(Float64(Float64(u2 * u2) * -0.3333333333333333), Float64(pi * pi), 0.16666666666666666), sqrt(Float64(log(u1) * -2.0)), 0.5) end
code[u1_, u2_] := N[(N[(N[(N[(u2 * u2), $MachinePrecision] * -0.3333333333333333), $MachinePrecision] * N[(Pi * Pi), $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(\left(u2 \cdot u2\right) \cdot -0.3333333333333333, \pi \cdot \pi, 0.16666666666666666\right), \sqrt{\log u1 \cdot -2}, 0.5\right)
\end{array}
Initial program 99.4%
lift-+.f64N/A
lift-*.f64N/A
lift-*.f64N/A
associate-*l*N/A
*-commutativeN/A
associate-*r*N/A
lower-fma.f64N/A
Applied rewrites99.4%
Taylor expanded in u2 around 0
+-commutativeN/A
associate-*r*N/A
lower-fma.f64N/A
*-commutativeN/A
lower-*.f64N/A
unpow2N/A
lower-*.f64N/A
unpow2N/A
lower-*.f64N/A
lower-PI.f64N/A
lower-PI.f6498.9
Applied rewrites98.9%
(FPCore (u1 u2) :precision binary64 (fma (* (sqrt 2.0) 0.16666666666666666) (sqrt (- (log u1))) 0.5))
double code(double u1, double u2) {
return fma((sqrt(2.0) * 0.16666666666666666), sqrt(-log(u1)), 0.5);
}
function code(u1, u2) return fma(Float64(sqrt(2.0) * 0.16666666666666666), sqrt(Float64(-log(u1))), 0.5) end
code[u1_, u2_] := N[(N[(N[Sqrt[2.0], $MachinePrecision] * 0.16666666666666666), $MachinePrecision] * N[Sqrt[(-N[Log[u1], $MachinePrecision])], $MachinePrecision] + 0.5), $MachinePrecision]
\begin{array}{l}
\\
\mathsf{fma}\left(\sqrt{2} \cdot 0.16666666666666666, \sqrt{-\log u1}, 0.5\right)
\end{array}
Initial program 99.4%
lift-pow.f64N/A
pow-to-expN/A
*-commutativeN/A
exp-prodN/A
lower-pow.f64N/A
lower-exp.f64N/A
lower-log.f6498.8
lift-*.f64N/A
*-commutativeN/A
lower-*.f6498.8
Applied rewrites98.8%
Taylor expanded in u1 around inf
+-commutativeN/A
associate-*r*N/A
lower-fma.f64N/A
Applied rewrites99.6%
Taylor expanded in u2 around 0
Applied rewrites98.7%
(FPCore (u1 u2) :precision binary64 (fma 0.16666666666666666 (* (sqrt 2.0) (sqrt (- (log u1)))) 0.5))
double code(double u1, double u2) {
return fma(0.16666666666666666, (sqrt(2.0) * sqrt(-log(u1))), 0.5);
}
function code(u1, u2) return fma(0.16666666666666666, Float64(sqrt(2.0) * sqrt(Float64(-log(u1)))), 0.5) end
code[u1_, u2_] := N[(0.16666666666666666 * N[(N[Sqrt[2.0], $MachinePrecision] * N[Sqrt[(-N[Log[u1], $MachinePrecision])], $MachinePrecision]), $MachinePrecision] + 0.5), $MachinePrecision]
\begin{array}{l}
\\
\mathsf{fma}\left(0.16666666666666666, \sqrt{2} \cdot \sqrt{-\log u1}, 0.5\right)
\end{array}
Initial program 99.4%
lift-pow.f64N/A
pow-to-expN/A
*-commutativeN/A
exp-prodN/A
lower-pow.f64N/A
lower-exp.f64N/A
lower-log.f6498.8
lift-*.f64N/A
*-commutativeN/A
lower-*.f6498.8
Applied rewrites98.8%
Taylor expanded in u1 around inf
+-commutativeN/A
associate-*r*N/A
lower-fma.f64N/A
Applied rewrites99.6%
Applied rewrites99.4%
Taylor expanded in u2 around 0
Applied rewrites98.5%
(FPCore (u1 u2) :precision binary64 (fma 0.16666666666666666 (sqrt (* (log u1) -2.0)) 0.5))
double code(double u1, double u2) {
return fma(0.16666666666666666, sqrt((log(u1) * -2.0)), 0.5);
}
function code(u1, u2) return fma(0.16666666666666666, sqrt(Float64(log(u1) * -2.0)), 0.5) end
code[u1_, u2_] := N[(0.16666666666666666 * N[Sqrt[N[(N[Log[u1], $MachinePrecision] * -2.0), $MachinePrecision]], $MachinePrecision] + 0.5), $MachinePrecision]
\begin{array}{l}
\\
\mathsf{fma}\left(0.16666666666666666, \sqrt{\log u1 \cdot -2}, 0.5\right)
\end{array}
Initial program 99.4%
lift-+.f64N/A
lift-*.f64N/A
lift-*.f64N/A
associate-*l*N/A
*-commutativeN/A
associate-*r*N/A
lower-fma.f64N/A
Applied rewrites99.4%
Taylor expanded in u2 around 0
Applied rewrites98.5%
herbie shell --seed 2024240
(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))