
(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 7 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-+.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 rewrites99.2%
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 (+ (* (cos (* (* PI 2.0) u2)) (* (sqrt (* (log u1) -2.0)) 0.16666666666666666)) 0.5))
double code(double u1, double u2) {
return (cos(((((double) M_PI) * 2.0) * u2)) * (sqrt((log(u1) * -2.0)) * 0.16666666666666666)) + 0.5;
}
public static double code(double u1, double u2) {
return (Math.cos(((Math.PI * 2.0) * u2)) * (Math.sqrt((Math.log(u1) * -2.0)) * 0.16666666666666666)) + 0.5;
}
def code(u1, u2): return (math.cos(((math.pi * 2.0) * u2)) * (math.sqrt((math.log(u1) * -2.0)) * 0.16666666666666666)) + 0.5
function code(u1, u2) return Float64(Float64(cos(Float64(Float64(pi * 2.0) * u2)) * Float64(sqrt(Float64(log(u1) * -2.0)) * 0.16666666666666666)) + 0.5) end
function tmp = code(u1, u2) tmp = (cos(((pi * 2.0) * u2)) * (sqrt((log(u1) * -2.0)) * 0.16666666666666666)) + 0.5; end
code[u1_, u2_] := N[(N[(N[Cos[N[(N[(Pi * 2.0), $MachinePrecision] * u2), $MachinePrecision]], $MachinePrecision] * N[(N[Sqrt[N[(N[Log[u1], $MachinePrecision] * -2.0), $MachinePrecision]], $MachinePrecision] * 0.16666666666666666), $MachinePrecision]), $MachinePrecision] + 0.5), $MachinePrecision]
\begin{array}{l}
\\
\cos \left(\left(\pi \cdot 2\right) \cdot u2\right) \cdot \left(\sqrt{\log u1 \cdot -2} \cdot 0.16666666666666666\right) + 0.5
\end{array}
Initial program 99.4%
lift-*.f64N/A
*-commutativeN/A
lower-*.f6499.4
lift-pow.f64N/A
unpow1/2N/A
lower-sqrt.f6499.4
lift-*.f64N/A
*-commutativeN/A
lower-*.f6499.4
lift-/.f64N/A
metadata-eval99.4
Applied rewrites99.4%
Final simplification99.4%
(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 (fma (sqrt (* -0.05555555555555555 (log u1))) (fabs (cos (* (* PI 2.0) u2))) 0.5))
double code(double u1, double u2) {
return fma(sqrt((-0.05555555555555555 * log(u1))), fabs(cos(((((double) M_PI) * 2.0) * u2))), 0.5);
}
function code(u1, u2) return fma(sqrt(Float64(-0.05555555555555555 * log(u1))), abs(cos(Float64(Float64(pi * 2.0) * u2))), 0.5) end
code[u1_, u2_] := N[(N[Sqrt[N[(-0.05555555555555555 * N[Log[u1], $MachinePrecision]), $MachinePrecision]], $MachinePrecision] * N[Abs[N[Cos[N[(N[(Pi * 2.0), $MachinePrecision] * u2), $MachinePrecision]], $MachinePrecision]], $MachinePrecision] + 0.5), $MachinePrecision]
\begin{array}{l}
\\
\mathsf{fma}\left(\sqrt{-0.05555555555555555 \cdot \log u1}, \left|\cos \left(\left(\pi \cdot 2\right) \cdot u2\right)\right|, 0.5\right)
\end{array}
Initial program 99.4%
lift-*.f64N/A
*-commutativeN/A
lower-*.f6499.4
lift-pow.f64N/A
unpow1/2N/A
lower-sqrt.f6499.4
lift-*.f64N/A
*-commutativeN/A
lower-*.f6499.4
lift-/.f64N/A
metadata-eval99.4
Applied rewrites99.4%
Applied rewrites99.4%
lift-pow.f64N/A
unpow1/2N/A
lower-sqrt.f6499.4
lift-*.f64N/A
*-commutativeN/A
lift-*.f64N/A
associate-*r*N/A
rem-square-sqrtN/A
lift-sqrt.f64N/A
lift-sqrt.f64N/A
metadata-evalN/A
swap-sqrN/A
Applied rewrites99.4%
lift-+.f64N/A
lift-sqrt.f64N/A
lift-*.f64N/A
sqrt-prodN/A
lower-fma.f64N/A
Applied rewrites99.4%
Final simplification99.4%
(FPCore (u1 u2) :precision binary64 (fma (* (fma (* -0.3333333333333333 (* u2 u2)) (* PI PI) 0.16666666666666666) (sqrt 2.0)) (sqrt (- (log u1))) 0.5))
double code(double u1, double u2) {
return fma((fma((-0.3333333333333333 * (u2 * u2)), (((double) M_PI) * ((double) M_PI)), 0.16666666666666666) * sqrt(2.0)), sqrt(-log(u1)), 0.5);
}
function code(u1, u2) return fma(Float64(fma(Float64(-0.3333333333333333 * Float64(u2 * u2)), Float64(pi * pi), 0.16666666666666666) * sqrt(2.0)), sqrt(Float64(-log(u1))), 0.5) end
code[u1_, u2_] := N[(N[(N[(N[(-0.3333333333333333 * N[(u2 * u2), $MachinePrecision]), $MachinePrecision] * N[(Pi * Pi), $MachinePrecision] + 0.16666666666666666), $MachinePrecision] * N[Sqrt[2.0], $MachinePrecision]), $MachinePrecision] * N[Sqrt[(-N[Log[u1], $MachinePrecision])], $MachinePrecision] + 0.5), $MachinePrecision]
\begin{array}{l}
\\
\mathsf{fma}\left(\mathsf{fma}\left(-0.3333333333333333 \cdot \left(u2 \cdot u2\right), \pi \cdot \pi, 0.16666666666666666\right) \cdot \sqrt{2}, \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 rewrites99.2%
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 rewrites98.2%
Final simplification98.2%
(FPCore (u1 u2)
:precision binary64
(+
(sqrt
(*
(fma (* u2 u2) (* 0.2222222222222222 (* PI PI)) -0.05555555555555555)
(log u1)))
0.5))
double code(double u1, double u2) {
return sqrt((fma((u2 * u2), (0.2222222222222222 * (((double) M_PI) * ((double) M_PI))), -0.05555555555555555) * log(u1))) + 0.5;
}
function code(u1, u2) return Float64(sqrt(Float64(fma(Float64(u2 * u2), Float64(0.2222222222222222 * Float64(pi * pi)), -0.05555555555555555) * log(u1))) + 0.5) end
code[u1_, u2_] := N[(N[Sqrt[N[(N[(N[(u2 * u2), $MachinePrecision] * N[(0.2222222222222222 * N[(Pi * Pi), $MachinePrecision]), $MachinePrecision] + -0.05555555555555555), $MachinePrecision] * N[Log[u1], $MachinePrecision]), $MachinePrecision]], $MachinePrecision] + 0.5), $MachinePrecision]
\begin{array}{l}
\\
\sqrt{\mathsf{fma}\left(u2 \cdot u2, 0.2222222222222222 \cdot \left(\pi \cdot \pi\right), -0.05555555555555555\right) \cdot \log u1} + 0.5
\end{array}
Initial program 99.4%
lift-*.f64N/A
*-commutativeN/A
lower-*.f6499.4
lift-pow.f64N/A
unpow1/2N/A
lower-sqrt.f6499.4
lift-*.f64N/A
*-commutativeN/A
lower-*.f6499.4
lift-/.f64N/A
metadata-eval99.4
Applied rewrites99.4%
Applied rewrites99.4%
lift-pow.f64N/A
unpow1/2N/A
lower-sqrt.f6499.4
lift-*.f64N/A
*-commutativeN/A
lift-*.f64N/A
associate-*r*N/A
rem-square-sqrtN/A
lift-sqrt.f64N/A
lift-sqrt.f64N/A
metadata-evalN/A
swap-sqrN/A
Applied rewrites99.4%
Taylor expanded in u2 around 0
+-commutativeN/A
*-commutativeN/A
associate-*r*N/A
*-commutativeN/A
associate-*r*N/A
associate-*r*N/A
distribute-rgt-outN/A
lower-*.f64N/A
lower-log.f64N/A
lower-fma.f64N/A
unpow2N/A
lower-*.f64N/A
*-commutativeN/A
lower-*.f64N/A
unpow2N/A
lower-*.f64N/A
lower-PI.f64N/A
lower-PI.f6498.2
Applied rewrites98.2%
Final simplification98.2%
(FPCore (u1 u2) :precision binary64 (+ (sqrt (* -0.05555555555555555 (log u1))) 0.5))
double code(double u1, double u2) {
return sqrt((-0.05555555555555555 * log(u1))) + 0.5;
}
real(8) function code(u1, u2)
real(8), intent (in) :: u1
real(8), intent (in) :: u2
code = sqrt(((-0.05555555555555555d0) * log(u1))) + 0.5d0
end function
public static double code(double u1, double u2) {
return Math.sqrt((-0.05555555555555555 * Math.log(u1))) + 0.5;
}
def code(u1, u2): return math.sqrt((-0.05555555555555555 * math.log(u1))) + 0.5
function code(u1, u2) return Float64(sqrt(Float64(-0.05555555555555555 * log(u1))) + 0.5) end
function tmp = code(u1, u2) tmp = sqrt((-0.05555555555555555 * log(u1))) + 0.5; end
code[u1_, u2_] := N[(N[Sqrt[N[(-0.05555555555555555 * N[Log[u1], $MachinePrecision]), $MachinePrecision]], $MachinePrecision] + 0.5), $MachinePrecision]
\begin{array}{l}
\\
\sqrt{-0.05555555555555555 \cdot \log u1} + 0.5
\end{array}
Initial program 99.4%
lift-*.f64N/A
*-commutativeN/A
lower-*.f6499.4
lift-pow.f64N/A
unpow1/2N/A
lower-sqrt.f6499.4
lift-*.f64N/A
*-commutativeN/A
lower-*.f6499.4
lift-/.f64N/A
metadata-eval99.4
Applied rewrites99.4%
Applied rewrites99.4%
Taylor expanded in u2 around 0
lower-*.f64N/A
lower-log.f6497.4
Applied rewrites97.4%
lift-pow.f64N/A
unpow1/2N/A
lower-sqrt.f6497.4
Applied rewrites97.4%
Final simplification97.4%
herbie shell --seed 2024235
(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))