
(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 5 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 (+ (* (sqrt (* (log u1) -0.05555555555555555)) (cos (* (* 2.0 PI) u2))) 0.5))
double code(double u1, double u2) {
return (sqrt((log(u1) * -0.05555555555555555)) * cos(((2.0 * ((double) M_PI)) * u2))) + 0.5;
}
public static double code(double u1, double u2) {
return (Math.sqrt((Math.log(u1) * -0.05555555555555555)) * Math.cos(((2.0 * Math.PI) * u2))) + 0.5;
}
def code(u1, u2): return (math.sqrt((math.log(u1) * -0.05555555555555555)) * math.cos(((2.0 * math.pi) * u2))) + 0.5
function code(u1, u2) return Float64(Float64(sqrt(Float64(log(u1) * -0.05555555555555555)) * cos(Float64(Float64(2.0 * pi) * u2))) + 0.5) end
function tmp = code(u1, u2) tmp = (sqrt((log(u1) * -0.05555555555555555)) * cos(((2.0 * pi) * u2))) + 0.5; end
code[u1_, u2_] := N[(N[(N[Sqrt[N[(N[Log[u1], $MachinePrecision] * -0.05555555555555555), $MachinePrecision]], $MachinePrecision] * N[Cos[N[(N[(2.0 * Pi), $MachinePrecision] * u2), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] + 0.5), $MachinePrecision]
\begin{array}{l}
\\
\sqrt{\log u1 \cdot -0.05555555555555555} \cdot \cos \left(\left(2 \cdot \pi\right) \cdot u2\right) + 0.5
\end{array}
Initial program 99.4%
add-sqr-sqrt99.0%
sqrt-unprod99.4%
pow1/299.4%
*-commutative99.4%
pow1/299.4%
*-commutative99.4%
swap-sqr99.3%
add-sqr-sqrt99.7%
metadata-eval99.7%
metadata-eval99.7%
metadata-eval99.7%
Applied egg-rr99.7%
*-commutative99.7%
associate-*l*99.7%
metadata-eval99.7%
Simplified99.7%
Final simplification99.7%
(FPCore (u1 u2) :precision binary64 (+ 0.5 (* 0.16666666666666666 (* (sqrt 2.0) (sqrt (- (log u1)))))))
double code(double u1, double u2) {
return 0.5 + (0.16666666666666666 * (sqrt(2.0) * sqrt(-log(u1))));
}
real(8) function code(u1, u2)
real(8), intent (in) :: u1
real(8), intent (in) :: u2
code = 0.5d0 + (0.16666666666666666d0 * (sqrt(2.0d0) * sqrt(-log(u1))))
end function
public static double code(double u1, double u2) {
return 0.5 + (0.16666666666666666 * (Math.sqrt(2.0) * Math.sqrt(-Math.log(u1))));
}
def code(u1, u2): return 0.5 + (0.16666666666666666 * (math.sqrt(2.0) * math.sqrt(-math.log(u1))))
function code(u1, u2) return Float64(0.5 + Float64(0.16666666666666666 * Float64(sqrt(2.0) * sqrt(Float64(-log(u1)))))) end
function tmp = code(u1, u2) tmp = 0.5 + (0.16666666666666666 * (sqrt(2.0) * sqrt(-log(u1)))); end
code[u1_, u2_] := N[(0.5 + N[(0.16666666666666666 * N[(N[Sqrt[2.0], $MachinePrecision] * N[Sqrt[(-N[Log[u1], $MachinePrecision])], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
0.5 + 0.16666666666666666 \cdot \left(\sqrt{2} \cdot \sqrt{-\log u1}\right)
\end{array}
Initial program 99.4%
*-commutative99.4%
associate-*l*99.4%
fma-def99.4%
unpow1/299.4%
metadata-eval99.4%
associate-*l*99.4%
Simplified99.4%
Taylor expanded in u2 around 0 98.1%
pow1/298.1%
sqr-pow97.8%
pow297.8%
metadata-eval97.8%
Applied egg-rr97.8%
Taylor expanded in u1 around inf 98.2%
*-un-lft-identity98.2%
log-rec98.2%
Applied egg-rr98.2%
*-lft-identity98.2%
Simplified98.2%
Final simplification98.2%
(FPCore (u1 u2) :precision binary64 (+ 0.5 (* (* 0.16666666666666666 (sqrt 2.0)) (sqrt (- (log u1))))))
double code(double u1, double u2) {
return 0.5 + ((0.16666666666666666 * sqrt(2.0)) * sqrt(-log(u1)));
}
real(8) function code(u1, u2)
real(8), intent (in) :: u1
real(8), intent (in) :: u2
code = 0.5d0 + ((0.16666666666666666d0 * sqrt(2.0d0)) * sqrt(-log(u1)))
end function
public static double code(double u1, double u2) {
return 0.5 + ((0.16666666666666666 * Math.sqrt(2.0)) * Math.sqrt(-Math.log(u1)));
}
def code(u1, u2): return 0.5 + ((0.16666666666666666 * math.sqrt(2.0)) * math.sqrt(-math.log(u1)))
function code(u1, u2) return Float64(0.5 + Float64(Float64(0.16666666666666666 * sqrt(2.0)) * sqrt(Float64(-log(u1))))) end
function tmp = code(u1, u2) tmp = 0.5 + ((0.16666666666666666 * sqrt(2.0)) * sqrt(-log(u1))); end
code[u1_, u2_] := N[(0.5 + N[(N[(0.16666666666666666 * N[Sqrt[2.0], $MachinePrecision]), $MachinePrecision] * N[Sqrt[(-N[Log[u1], $MachinePrecision])], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
0.5 + \left(0.16666666666666666 \cdot \sqrt{2}\right) \cdot \sqrt{-\log u1}
\end{array}
Initial program 99.4%
*-commutative99.4%
associate-*l*99.4%
fma-def99.4%
unpow1/299.4%
metadata-eval99.4%
associate-*l*99.4%
Simplified99.4%
Taylor expanded in u2 around 0 98.1%
pow1/298.1%
sqr-pow97.8%
pow297.8%
metadata-eval97.8%
Applied egg-rr97.8%
Taylor expanded in u1 around inf 98.2%
associate-*r*98.3%
log-rec98.3%
Simplified98.3%
Final simplification98.3%
(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%
*-commutative99.4%
associate-*l*99.4%
fma-def99.4%
unpow1/299.4%
metadata-eval99.4%
associate-*l*99.4%
Simplified99.4%
Taylor expanded in u2 around 0 98.1%
metadata-eval98.1%
fma-udef98.1%
*-commutative98.1%
Applied egg-rr98.1%
fma-def98.1%
Simplified98.1%
Final simplification98.1%
(FPCore (u1 u2) :precision binary64 (+ 0.5 (* 0.16666666666666666 (sqrt (* (log u1) -2.0)))))
double code(double u1, double u2) {
return 0.5 + (0.16666666666666666 * sqrt((log(u1) * -2.0)));
}
real(8) function code(u1, u2)
real(8), intent (in) :: u1
real(8), intent (in) :: u2
code = 0.5d0 + (0.16666666666666666d0 * sqrt((log(u1) * (-2.0d0))))
end function
public static double code(double u1, double u2) {
return 0.5 + (0.16666666666666666 * Math.sqrt((Math.log(u1) * -2.0)));
}
def code(u1, u2): return 0.5 + (0.16666666666666666 * math.sqrt((math.log(u1) * -2.0)))
function code(u1, u2) return Float64(0.5 + Float64(0.16666666666666666 * sqrt(Float64(log(u1) * -2.0)))) end
function tmp = code(u1, u2) tmp = 0.5 + (0.16666666666666666 * sqrt((log(u1) * -2.0))); end
code[u1_, u2_] := N[(0.5 + N[(0.16666666666666666 * N[Sqrt[N[(N[Log[u1], $MachinePrecision] * -2.0), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
0.5 + 0.16666666666666666 \cdot \sqrt{\log u1 \cdot -2}
\end{array}
Initial program 99.4%
*-commutative99.4%
associate-*l*99.4%
fma-def99.4%
unpow1/299.4%
metadata-eval99.4%
associate-*l*99.4%
Simplified99.4%
Taylor expanded in u2 around 0 98.1%
metadata-eval98.1%
fma-udef98.1%
*-commutative98.1%
Applied egg-rr98.1%
Final simplification98.1%
herbie shell --seed 2023229
(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))