
(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 (sqrt (- (log u1))) (* (* 0.16666666666666666 (sqrt 2.0)) (cos (* 2.0 (* u2 PI)))) 0.5))
double code(double u1, double u2) {
return fma(sqrt(-log(u1)), ((0.16666666666666666 * sqrt(2.0)) * cos((2.0 * (u2 * ((double) M_PI))))), 0.5);
}
function code(u1, u2) return fma(sqrt(Float64(-log(u1))), Float64(Float64(0.16666666666666666 * sqrt(2.0)) * cos(Float64(2.0 * Float64(u2 * pi)))), 0.5) end
code[u1_, u2_] := N[(N[Sqrt[(-N[Log[u1], $MachinePrecision])], $MachinePrecision] * N[(N[(0.16666666666666666 * N[Sqrt[2.0], $MachinePrecision]), $MachinePrecision] * N[Cos[N[(2.0 * N[(u2 * Pi), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] + 0.5), $MachinePrecision]
\begin{array}{l}
\\
\mathsf{fma}\left(\sqrt{-\log u1}, \left(0.16666666666666666 \cdot \sqrt{2}\right) \cdot \cos \left(2 \cdot \left(u2 \cdot \pi\right)\right), 0.5\right)
\end{array}
Initial program 99.4%
lift-+.f64N/A
lift-*.f64N/A
lift-*.f64N/A
*-commutativeN/A
associate-*l*N/A
lift-pow.f64N/A
sqr-powN/A
associate-*l*N/A
lower-fma.f64N/A
Applied rewrites99.1%
Taylor expanded in u1 around inf
+-commutativeN/A
associate-*r*N/A
*-commutativeN/A
lower-fma.f64N/A
Applied rewrites99.5%
(FPCore (u1 u2) :precision binary64 (fma (* (sqrt (* -2.0 (log u1))) (cos (* 2.0 (* u2 PI)))) 0.16666666666666666 0.5))
double code(double u1, double u2) {
return fma((sqrt((-2.0 * log(u1))) * cos((2.0 * (u2 * ((double) M_PI))))), 0.16666666666666666, 0.5);
}
function code(u1, u2) return fma(Float64(sqrt(Float64(-2.0 * log(u1))) * cos(Float64(2.0 * Float64(u2 * pi)))), 0.16666666666666666, 0.5) end
code[u1_, u2_] := N[(N[(N[Sqrt[N[(-2.0 * N[Log[u1], $MachinePrecision]), $MachinePrecision]], $MachinePrecision] * N[Cos[N[(2.0 * N[(u2 * Pi), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] * 0.16666666666666666 + 0.5), $MachinePrecision]
\begin{array}{l}
\\
\mathsf{fma}\left(\sqrt{-2 \cdot \log u1} \cdot \cos \left(2 \cdot \left(u2 \cdot \pi\right)\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%
Final simplification99.4%
(FPCore (u1 u2) :precision binary64 (fma (* 0.16666666666666666 (sqrt (* -2.0 (log u1)))) (cos (* 2.0 (* u2 PI))) 0.5))
double code(double u1, double u2) {
return fma((0.16666666666666666 * sqrt((-2.0 * log(u1)))), cos((2.0 * (u2 * ((double) M_PI)))), 0.5);
}
function code(u1, u2) return fma(Float64(0.16666666666666666 * sqrt(Float64(-2.0 * log(u1)))), cos(Float64(2.0 * Float64(u2 * pi))), 0.5) end
code[u1_, u2_] := N[(N[(0.16666666666666666 * N[Sqrt[N[(-2.0 * N[Log[u1], $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] * N[Cos[N[(2.0 * N[(u2 * Pi), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] + 0.5), $MachinePrecision]
\begin{array}{l}
\\
\mathsf{fma}\left(0.16666666666666666 \cdot \sqrt{-2 \cdot \log u1}, \cos \left(2 \cdot \left(u2 \cdot \pi\right)\right), 0.5\right)
\end{array}
Initial program 99.4%
lift-+.f64N/A
lift-*.f64N/A
lower-fma.f6499.4
lift-*.f64N/A
*-commutativeN/A
lower-*.f6499.4
lift-pow.f64N/A
unpow1/2N/A
lower-sqrt.f6499.4
lift-/.f64N/A
metadata-eval99.4
lift-*.f64N/A
lift-*.f64N/A
associate-*l*N/A
lower-*.f64N/A
lower-*.f6499.4
Applied rewrites99.4%
Final simplification99.4%
(FPCore (u1 u2) :precision binary64 (fma (sqrt (- (log u1))) (* (sqrt 2.0) (fma (* u2 u2) (* -0.3333333333333333 (* PI PI)) 0.16666666666666666)) 0.5))
double code(double u1, double u2) {
return fma(sqrt(-log(u1)), (sqrt(2.0) * fma((u2 * u2), (-0.3333333333333333 * (((double) M_PI) * ((double) M_PI))), 0.16666666666666666)), 0.5);
}
function code(u1, u2) return fma(sqrt(Float64(-log(u1))), Float64(sqrt(2.0) * fma(Float64(u2 * u2), Float64(-0.3333333333333333 * Float64(pi * pi)), 0.16666666666666666)), 0.5) end
code[u1_, u2_] := N[(N[Sqrt[(-N[Log[u1], $MachinePrecision])], $MachinePrecision] * N[(N[Sqrt[2.0], $MachinePrecision] * N[(N[(u2 * u2), $MachinePrecision] * N[(-0.3333333333333333 * N[(Pi * Pi), $MachinePrecision]), $MachinePrecision] + 0.16666666666666666), $MachinePrecision]), $MachinePrecision] + 0.5), $MachinePrecision]
\begin{array}{l}
\\
\mathsf{fma}\left(\sqrt{-\log u1}, \sqrt{2} \cdot \mathsf{fma}\left(u2 \cdot u2, -0.3333333333333333 \cdot \left(\pi \cdot \pi\right), 0.16666666666666666\right), 0.5\right)
\end{array}
Initial program 99.4%
lift-+.f64N/A
lift-*.f64N/A
lift-*.f64N/A
*-commutativeN/A
associate-*l*N/A
lift-pow.f64N/A
sqr-powN/A
associate-*l*N/A
lower-fma.f64N/A
Applied rewrites99.1%
Taylor expanded in u1 around inf
+-commutativeN/A
associate-*r*N/A
*-commutativeN/A
lower-fma.f64N/A
Applied rewrites99.5%
Taylor expanded in u2 around 0
Applied rewrites98.1%
Taylor expanded in u2 around 0
Applied rewrites98.9%
(FPCore (u1 u2) :precision binary64 (fma (* 0.16666666666666666 (sqrt (* 2.0 (- (log u1))))) (fma (* PI PI) (* -2.0 (* u2 u2)) 1.0) 0.5))
double code(double u1, double u2) {
return fma((0.16666666666666666 * sqrt((2.0 * -log(u1)))), fma((((double) M_PI) * ((double) M_PI)), (-2.0 * (u2 * u2)), 1.0), 0.5);
}
function code(u1, u2) return fma(Float64(0.16666666666666666 * sqrt(Float64(2.0 * Float64(-log(u1))))), fma(Float64(pi * pi), Float64(-2.0 * Float64(u2 * u2)), 1.0), 0.5) end
code[u1_, u2_] := N[(N[(0.16666666666666666 * N[Sqrt[N[(2.0 * (-N[Log[u1], $MachinePrecision])), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] * N[(N[(Pi * Pi), $MachinePrecision] * N[(-2.0 * N[(u2 * u2), $MachinePrecision]), $MachinePrecision] + 1.0), $MachinePrecision] + 0.5), $MachinePrecision]
\begin{array}{l}
\\
\mathsf{fma}\left(0.16666666666666666 \cdot \sqrt{2 \cdot \left(-\log u1\right)}, \mathsf{fma}\left(\pi \cdot \pi, -2 \cdot \left(u2 \cdot u2\right), 1\right), 0.5\right)
\end{array}
Initial program 99.4%
Taylor expanded in u1 around inf
lower-*.f64N/A
lower-sqrt.f64N/A
log-recN/A
lower-neg.f64N/A
lower-log.f64N/A
lower-sqrt.f6499.5
Applied rewrites99.5%
Taylor expanded in u2 around 0
+-commutativeN/A
associate-*r*N/A
*-commutativeN/A
rem-square-sqrtN/A
unpow2N/A
lower-fma.f64N/A
unpow2N/A
lower-*.f64N/A
lower-PI.f64N/A
lower-PI.f64N/A
*-commutativeN/A
lower-*.f64N/A
unpow2N/A
lower-*.f64N/A
unpow2N/A
rem-square-sqrt98.8
Applied rewrites98.8%
lift-+.f64N/A
lift-*.f64N/A
lower-fma.f6498.8
Applied rewrites98.7%
Final simplification98.7%
(FPCore (u1 u2) :precision binary64 (fma (sqrt (- (log u1))) (* 0.16666666666666666 (sqrt 2.0)) 0.5))
double code(double u1, double u2) {
return fma(sqrt(-log(u1)), (0.16666666666666666 * sqrt(2.0)), 0.5);
}
function code(u1, u2) return fma(sqrt(Float64(-log(u1))), Float64(0.16666666666666666 * sqrt(2.0)), 0.5) end
code[u1_, u2_] := N[(N[Sqrt[(-N[Log[u1], $MachinePrecision])], $MachinePrecision] * N[(0.16666666666666666 * N[Sqrt[2.0], $MachinePrecision]), $MachinePrecision] + 0.5), $MachinePrecision]
\begin{array}{l}
\\
\mathsf{fma}\left(\sqrt{-\log u1}, 0.16666666666666666 \cdot \sqrt{2}, 0.5\right)
\end{array}
Initial program 99.4%
lift-+.f64N/A
lift-*.f64N/A
lift-*.f64N/A
*-commutativeN/A
associate-*l*N/A
lift-pow.f64N/A
sqr-powN/A
associate-*l*N/A
lower-fma.f64N/A
Applied rewrites99.1%
Taylor expanded in u1 around inf
+-commutativeN/A
associate-*r*N/A
*-commutativeN/A
lower-fma.f64N/A
Applied rewrites99.5%
Taylor expanded in u2 around 0
Applied rewrites98.1%
(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(sqrt(2.0), Float64(0.16666666666666666 * sqrt(Float64(-log(u1)))), 0.5) end
code[u1_, u2_] := N[(N[Sqrt[2.0], $MachinePrecision] * N[(0.16666666666666666 * N[Sqrt[(-N[Log[u1], $MachinePrecision])], $MachinePrecision]), $MachinePrecision] + 0.5), $MachinePrecision]
\begin{array}{l}
\\
\mathsf{fma}\left(\sqrt{2}, 0.16666666666666666 \cdot \sqrt{-\log u1}, 0.5\right)
\end{array}
Initial program 99.4%
lift-+.f64N/A
lift-*.f64N/A
lift-*.f64N/A
*-commutativeN/A
associate-*l*N/A
lift-pow.f64N/A
sqr-powN/A
associate-*l*N/A
lower-fma.f64N/A
Applied rewrites99.1%
Taylor expanded in u1 around inf
+-commutativeN/A
associate-*r*N/A
*-commutativeN/A
lower-fma.f64N/A
Applied rewrites99.5%
Taylor expanded in u1 around inf
+-commutativeN/A
associate-*r*N/A
*-commutativeN/A
associate-*l*N/A
lower-fma.f64N/A
Applied rewrites99.5%
Taylor expanded in u2 around 0
Applied rewrites98.0%
(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
+-commutativeN/A
*-commutativeN/A
associate-*l*N/A
*-commutativeN/A
lower-fma.f64N/A
lower-sqrt.f64N/A
lower-log.f64N/A
*-commutativeN/A
lower-*.f64N/A
lower-sqrt.f640.0
Applied rewrites0.0%
Applied rewrites97.9%
herbie shell --seed 2024219
(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))