
(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 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
(+
0.5
(pow
(*
(* (* -2.0 (log u1)) 0.027777777777777776)
(+ 0.5 (* 0.5 (cos (* 2.0 (* 2.0 (* PI u2)))))))
0.5)))
double code(double u1, double u2) {
return 0.5 + pow((((-2.0 * log(u1)) * 0.027777777777777776) * (0.5 + (0.5 * cos((2.0 * (2.0 * (((double) M_PI) * u2))))))), 0.5);
}
public static double code(double u1, double u2) {
return 0.5 + Math.pow((((-2.0 * Math.log(u1)) * 0.027777777777777776) * (0.5 + (0.5 * Math.cos((2.0 * (2.0 * (Math.PI * u2))))))), 0.5);
}
def code(u1, u2): return 0.5 + math.pow((((-2.0 * math.log(u1)) * 0.027777777777777776) * (0.5 + (0.5 * math.cos((2.0 * (2.0 * (math.pi * u2))))))), 0.5)
function code(u1, u2) return Float64(0.5 + (Float64(Float64(Float64(-2.0 * log(u1)) * 0.027777777777777776) * Float64(0.5 + Float64(0.5 * cos(Float64(2.0 * Float64(2.0 * Float64(pi * u2))))))) ^ 0.5)) end
function tmp = code(u1, u2) tmp = 0.5 + ((((-2.0 * log(u1)) * 0.027777777777777776) * (0.5 + (0.5 * cos((2.0 * (2.0 * (pi * u2))))))) ^ 0.5); end
code[u1_, u2_] := N[(0.5 + N[Power[N[(N[(N[(-2.0 * N[Log[u1], $MachinePrecision]), $MachinePrecision] * 0.027777777777777776), $MachinePrecision] * N[(0.5 + N[(0.5 * N[Cos[N[(2.0 * N[(2.0 * N[(Pi * u2), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], 0.5], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
0.5 + {\left(\left(\left(-2 \cdot \log u1\right) \cdot 0.027777777777777776\right) \cdot \left(0.5 + 0.5 \cdot \cos \left(2 \cdot \left(2 \cdot \left(\pi \cdot u2\right)\right)\right)\right)\right)}^{0.5}
\end{array}
Initial program 99.5%
lift-pow.f64N/A
sqr-powN/A
pow2N/A
lower-pow.f64N/A
metadata-evalN/A
metadata-evalN/A
lower-pow.f64N/A
metadata-eval99.1
Applied rewrites99.1%
Applied rewrites99.7%
Final simplification99.7%
(FPCore (u1 u2) :precision binary64 (fma (sqrt (* (log u1) -0.05555555555555555)) (fabs (cos (* 2.0 (* PI u2)))) 0.5))
double code(double u1, double u2) {
return fma(sqrt((log(u1) * -0.05555555555555555)), fabs(cos((2.0 * (((double) M_PI) * u2)))), 0.5);
}
function code(u1, u2) return fma(sqrt(Float64(log(u1) * -0.05555555555555555)), abs(cos(Float64(2.0 * Float64(pi * u2)))), 0.5) end
code[u1_, u2_] := N[(N[Sqrt[N[(N[Log[u1], $MachinePrecision] * -0.05555555555555555), $MachinePrecision]], $MachinePrecision] * N[Abs[N[Cos[N[(2.0 * N[(Pi * u2), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]], $MachinePrecision] + 0.5), $MachinePrecision]
\begin{array}{l}
\\
\mathsf{fma}\left(\sqrt{\log u1 \cdot -0.05555555555555555}, \left|\cos \left(2 \cdot \left(\pi \cdot u2\right)\right)\right|, 0.5\right)
\end{array}
Initial program 99.5%
lift-pow.f64N/A
sqr-powN/A
pow2N/A
lower-pow.f64N/A
metadata-evalN/A
metadata-evalN/A
lower-pow.f64N/A
metadata-eval99.1
Applied rewrites99.1%
Applied rewrites99.7%
Applied rewrites99.7%
(FPCore (u1 u2)
:precision binary64
(+
0.5
(pow
(*
(log u1)
(fma (* (* u2 u2) 0.2222222222222222) (* PI PI) -0.05555555555555555))
0.5)))
double code(double u1, double u2) {
return 0.5 + pow((log(u1) * fma(((u2 * u2) * 0.2222222222222222), (((double) M_PI) * ((double) M_PI)), -0.05555555555555555)), 0.5);
}
function code(u1, u2) return Float64(0.5 + (Float64(log(u1) * fma(Float64(Float64(u2 * u2) * 0.2222222222222222), Float64(pi * pi), -0.05555555555555555)) ^ 0.5)) end
code[u1_, u2_] := N[(0.5 + N[Power[N[(N[Log[u1], $MachinePrecision] * N[(N[(N[(u2 * u2), $MachinePrecision] * 0.2222222222222222), $MachinePrecision] * N[(Pi * Pi), $MachinePrecision] + -0.05555555555555555), $MachinePrecision]), $MachinePrecision], 0.5], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
0.5 + {\left(\log u1 \cdot \mathsf{fma}\left(\left(u2 \cdot u2\right) \cdot 0.2222222222222222, \pi \cdot \pi, -0.05555555555555555\right)\right)}^{0.5}
\end{array}
Initial program 99.5%
lift-pow.f64N/A
sqr-powN/A
pow2N/A
lower-pow.f64N/A
metadata-evalN/A
metadata-evalN/A
lower-pow.f64N/A
metadata-eval99.1
Applied rewrites99.1%
Applied rewrites99.7%
Taylor expanded in u2 around 0
+-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
*-commutativeN/A
lower-*.f64N/A
unpow2N/A
lower-*.f64N/A
unpow2N/A
lower-*.f64N/A
lower-PI.f64N/A
lower-PI.f6499.6
Applied rewrites99.6%
Final simplification99.6%
(FPCore (u1 u2) :precision binary64 (+ 0.5 (* (* (/ 1.0 6.0) (* (sqrt (- (log u1))) (sqrt 2.0))) (fma u2 (* u2 (* -2.0 (* PI PI))) 1.0))))
double code(double u1, double u2) {
return 0.5 + (((1.0 / 6.0) * (sqrt(-log(u1)) * sqrt(2.0))) * fma(u2, (u2 * (-2.0 * (((double) M_PI) * ((double) M_PI)))), 1.0));
}
function code(u1, u2) return Float64(0.5 + Float64(Float64(Float64(1.0 / 6.0) * Float64(sqrt(Float64(-log(u1))) * sqrt(2.0))) * fma(u2, Float64(u2 * Float64(-2.0 * Float64(pi * pi))), 1.0))) end
code[u1_, u2_] := N[(0.5 + N[(N[(N[(1.0 / 6.0), $MachinePrecision] * N[(N[Sqrt[(-N[Log[u1], $MachinePrecision])], $MachinePrecision] * N[Sqrt[2.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * N[(u2 * N[(u2 * N[(-2.0 * N[(Pi * Pi), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + 1.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
0.5 + \left(\frac{1}{6} \cdot \left(\sqrt{-\log u1} \cdot \sqrt{2}\right)\right) \cdot \mathsf{fma}\left(u2, u2 \cdot \left(-2 \cdot \left(\pi \cdot \pi\right)\right), 1\right)
\end{array}
Initial program 99.5%
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
*-commutativeN/A
rem-square-sqrtN/A
unpow2N/A
associate-*r*N/A
unpow2N/A
unpow2N/A
rem-square-sqrtN/A
*-commutativeN/A
associate-*l*N/A
lower-fma.f64N/A
Applied rewrites99.4%
Final simplification99.4%
(FPCore (u1 u2) :precision binary64 (fma (* (sqrt (- (* (log u1) 2.0))) (fma u2 (* -2.0 (* u2 (* PI PI))) 1.0)) 0.16666666666666666 0.5))
double code(double u1, double u2) {
return fma((sqrt(-(log(u1) * 2.0)) * fma(u2, (-2.0 * (u2 * (((double) M_PI) * ((double) M_PI)))), 1.0)), 0.16666666666666666, 0.5);
}
function code(u1, u2) return fma(Float64(sqrt(Float64(-Float64(log(u1) * 2.0))) * fma(u2, Float64(-2.0 * Float64(u2 * Float64(pi * pi))), 1.0)), 0.16666666666666666, 0.5) end
code[u1_, u2_] := N[(N[(N[Sqrt[(-N[(N[Log[u1], $MachinePrecision] * 2.0), $MachinePrecision])], $MachinePrecision] * N[(u2 * N[(-2.0 * N[(u2 * N[(Pi * Pi), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + 1.0), $MachinePrecision]), $MachinePrecision] * 0.16666666666666666 + 0.5), $MachinePrecision]
\begin{array}{l}
\\
\mathsf{fma}\left(\sqrt{-\log u1 \cdot 2} \cdot \mathsf{fma}\left(u2, -2 \cdot \left(u2 \cdot \left(\pi \cdot \pi\right)\right), 1\right), 0.16666666666666666, 0.5\right)
\end{array}
Initial program 99.5%
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
*-commutativeN/A
rem-square-sqrtN/A
unpow2N/A
associate-*r*N/A
unpow2N/A
unpow2N/A
rem-square-sqrtN/A
*-commutativeN/A
associate-*l*N/A
lower-fma.f64N/A
Applied rewrites99.4%
lift-+.f64N/A
Applied rewrites99.4%
(FPCore (u1 u2) :precision binary64 (- (sqrt (* (log u1) -0.05555555555555555)) -0.5))
double code(double u1, double u2) {
return sqrt((log(u1) * -0.05555555555555555)) - -0.5;
}
real(8) function code(u1, u2)
real(8), intent (in) :: u1
real(8), intent (in) :: u2
code = sqrt((log(u1) * (-0.05555555555555555d0))) - (-0.5d0)
end function
public static double code(double u1, double u2) {
return Math.sqrt((Math.log(u1) * -0.05555555555555555)) - -0.5;
}
def code(u1, u2): return math.sqrt((math.log(u1) * -0.05555555555555555)) - -0.5
function code(u1, u2) return Float64(sqrt(Float64(log(u1) * -0.05555555555555555)) - -0.5) end
function tmp = code(u1, u2) tmp = sqrt((log(u1) * -0.05555555555555555)) - -0.5; end
code[u1_, u2_] := N[(N[Sqrt[N[(N[Log[u1], $MachinePrecision] * -0.05555555555555555), $MachinePrecision]], $MachinePrecision] - -0.5), $MachinePrecision]
\begin{array}{l}
\\
\sqrt{\log u1 \cdot -0.05555555555555555} - -0.5
\end{array}
Initial program 99.5%
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 rewrites99.1%
Applied rewrites99.3%
herbie shell --seed 2024233
(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))