
(FPCore (a rand) :precision binary64 (let* ((t_0 (- a (/ 1.0 3.0)))) (* t_0 (+ 1.0 (* (/ 1.0 (sqrt (* 9.0 t_0))) rand)))))
double code(double a, double rand) {
double t_0 = a - (1.0 / 3.0);
return t_0 * (1.0 + ((1.0 / sqrt((9.0 * t_0))) * rand));
}
real(8) function code(a, rand)
real(8), intent (in) :: a
real(8), intent (in) :: rand
real(8) :: t_0
t_0 = a - (1.0d0 / 3.0d0)
code = t_0 * (1.0d0 + ((1.0d0 / sqrt((9.0d0 * t_0))) * rand))
end function
public static double code(double a, double rand) {
double t_0 = a - (1.0 / 3.0);
return t_0 * (1.0 + ((1.0 / Math.sqrt((9.0 * t_0))) * rand));
}
def code(a, rand): t_0 = a - (1.0 / 3.0) return t_0 * (1.0 + ((1.0 / math.sqrt((9.0 * t_0))) * rand))
function code(a, rand) t_0 = Float64(a - Float64(1.0 / 3.0)) return Float64(t_0 * Float64(1.0 + Float64(Float64(1.0 / sqrt(Float64(9.0 * t_0))) * rand))) end
function tmp = code(a, rand) t_0 = a - (1.0 / 3.0); tmp = t_0 * (1.0 + ((1.0 / sqrt((9.0 * t_0))) * rand)); end
code[a_, rand_] := Block[{t$95$0 = N[(a - N[(1.0 / 3.0), $MachinePrecision]), $MachinePrecision]}, N[(t$95$0 * N[(1.0 + N[(N[(1.0 / N[Sqrt[N[(9.0 * t$95$0), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] * rand), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
t_0 := a - \frac{1}{3}\\
t\_0 \cdot \left(1 + \frac{1}{\sqrt{9 \cdot t\_0}} \cdot rand\right)
\end{array}
\end{array}
Sampling outcomes in binary64 precision:
Herbie found 7 alternatives:
| Alternative | Accuracy | Speedup |
|---|
(FPCore (a rand) :precision binary64 (let* ((t_0 (- a (/ 1.0 3.0)))) (* t_0 (+ 1.0 (* (/ 1.0 (sqrt (* 9.0 t_0))) rand)))))
double code(double a, double rand) {
double t_0 = a - (1.0 / 3.0);
return t_0 * (1.0 + ((1.0 / sqrt((9.0 * t_0))) * rand));
}
real(8) function code(a, rand)
real(8), intent (in) :: a
real(8), intent (in) :: rand
real(8) :: t_0
t_0 = a - (1.0d0 / 3.0d0)
code = t_0 * (1.0d0 + ((1.0d0 / sqrt((9.0d0 * t_0))) * rand))
end function
public static double code(double a, double rand) {
double t_0 = a - (1.0 / 3.0);
return t_0 * (1.0 + ((1.0 / Math.sqrt((9.0 * t_0))) * rand));
}
def code(a, rand): t_0 = a - (1.0 / 3.0) return t_0 * (1.0 + ((1.0 / math.sqrt((9.0 * t_0))) * rand))
function code(a, rand) t_0 = Float64(a - Float64(1.0 / 3.0)) return Float64(t_0 * Float64(1.0 + Float64(Float64(1.0 / sqrt(Float64(9.0 * t_0))) * rand))) end
function tmp = code(a, rand) t_0 = a - (1.0 / 3.0); tmp = t_0 * (1.0 + ((1.0 / sqrt((9.0 * t_0))) * rand)); end
code[a_, rand_] := Block[{t$95$0 = N[(a - N[(1.0 / 3.0), $MachinePrecision]), $MachinePrecision]}, N[(t$95$0 * N[(1.0 + N[(N[(1.0 / N[Sqrt[N[(9.0 * t$95$0), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] * rand), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
t_0 := a - \frac{1}{3}\\
t\_0 \cdot \left(1 + \frac{1}{\sqrt{9 \cdot t\_0}} \cdot rand\right)
\end{array}
\end{array}
(FPCore (a rand) :precision binary64 (* (fma rand (sqrt (/ 1.0 (fma a 9.0 -3.0))) 1.0) (+ a -0.3333333333333333)))
double code(double a, double rand) {
return fma(rand, sqrt((1.0 / fma(a, 9.0, -3.0))), 1.0) * (a + -0.3333333333333333);
}
function code(a, rand) return Float64(fma(rand, sqrt(Float64(1.0 / fma(a, 9.0, -3.0))), 1.0) * Float64(a + -0.3333333333333333)) end
code[a_, rand_] := N[(N[(rand * N[Sqrt[N[(1.0 / N[(a * 9.0 + -3.0), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] + 1.0), $MachinePrecision] * N[(a + -0.3333333333333333), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\mathsf{fma}\left(rand, \sqrt{\frac{1}{\mathsf{fma}\left(a, 9, -3\right)}}, 1\right) \cdot \left(a + -0.3333333333333333\right)
\end{array}
Initial program 99.8%
Taylor expanded in a around 0
sub-negN/A
*-commutativeN/A
metadata-evalN/A
rem-square-sqrtN/A
unpow2N/A
lower-fma.f64N/A
unpow2N/A
rem-square-sqrt99.8
Simplified99.8%
Taylor expanded in rand around 0
+-commutativeN/A
associate--l+N/A
associate-*l*N/A
*-commutativeN/A
associate-*r*N/A
distribute-lft1-inN/A
rgt-mult-inverseN/A
distribute-lft-inN/A
lower-*.f64N/A
Simplified99.9%
(FPCore (a rand) :precision binary64 (* (+ a -0.3333333333333333) (fma rand (sqrt (/ 0.1111111111111111 a)) 1.0)))
double code(double a, double rand) {
return (a + -0.3333333333333333) * fma(rand, sqrt((0.1111111111111111 / a)), 1.0);
}
function code(a, rand) return Float64(Float64(a + -0.3333333333333333) * fma(rand, sqrt(Float64(0.1111111111111111 / a)), 1.0)) end
code[a_, rand_] := N[(N[(a + -0.3333333333333333), $MachinePrecision] * N[(rand * N[Sqrt[N[(0.1111111111111111 / a), $MachinePrecision]], $MachinePrecision] + 1.0), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\left(a + -0.3333333333333333\right) \cdot \mathsf{fma}\left(rand, \sqrt{\frac{0.1111111111111111}{a}}, 1\right)
\end{array}
Initial program 99.8%
Taylor expanded in a around 0
sub-negN/A
*-commutativeN/A
metadata-evalN/A
rem-square-sqrtN/A
unpow2N/A
lower-fma.f64N/A
unpow2N/A
rem-square-sqrt99.8
Simplified99.8%
Taylor expanded in rand around 0
+-commutativeN/A
associate--l+N/A
associate-*l*N/A
*-commutativeN/A
associate-*r*N/A
distribute-lft1-inN/A
rgt-mult-inverseN/A
distribute-lft-inN/A
lower-*.f64N/A
Simplified99.9%
Taylor expanded in a around inf
lower-/.f6499.1
Simplified99.1%
Final simplification99.1%
(FPCore (a rand)
:precision binary64
(let* ((t_0 (* 0.3333333333333333 (* rand (sqrt a)))))
(if (<= rand -1.3e+45)
t_0
(if (<= rand 6.5e+76) (+ a -0.3333333333333333) t_0))))
double code(double a, double rand) {
double t_0 = 0.3333333333333333 * (rand * sqrt(a));
double tmp;
if (rand <= -1.3e+45) {
tmp = t_0;
} else if (rand <= 6.5e+76) {
tmp = a + -0.3333333333333333;
} else {
tmp = t_0;
}
return tmp;
}
real(8) function code(a, rand)
real(8), intent (in) :: a
real(8), intent (in) :: rand
real(8) :: t_0
real(8) :: tmp
t_0 = 0.3333333333333333d0 * (rand * sqrt(a))
if (rand <= (-1.3d+45)) then
tmp = t_0
else if (rand <= 6.5d+76) then
tmp = a + (-0.3333333333333333d0)
else
tmp = t_0
end if
code = tmp
end function
public static double code(double a, double rand) {
double t_0 = 0.3333333333333333 * (rand * Math.sqrt(a));
double tmp;
if (rand <= -1.3e+45) {
tmp = t_0;
} else if (rand <= 6.5e+76) {
tmp = a + -0.3333333333333333;
} else {
tmp = t_0;
}
return tmp;
}
def code(a, rand): t_0 = 0.3333333333333333 * (rand * math.sqrt(a)) tmp = 0 if rand <= -1.3e+45: tmp = t_0 elif rand <= 6.5e+76: tmp = a + -0.3333333333333333 else: tmp = t_0 return tmp
function code(a, rand) t_0 = Float64(0.3333333333333333 * Float64(rand * sqrt(a))) tmp = 0.0 if (rand <= -1.3e+45) tmp = t_0; elseif (rand <= 6.5e+76) tmp = Float64(a + -0.3333333333333333); else tmp = t_0; end return tmp end
function tmp_2 = code(a, rand) t_0 = 0.3333333333333333 * (rand * sqrt(a)); tmp = 0.0; if (rand <= -1.3e+45) tmp = t_0; elseif (rand <= 6.5e+76) tmp = a + -0.3333333333333333; else tmp = t_0; end tmp_2 = tmp; end
code[a_, rand_] := Block[{t$95$0 = N[(0.3333333333333333 * N[(rand * N[Sqrt[a], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]}, If[LessEqual[rand, -1.3e+45], t$95$0, If[LessEqual[rand, 6.5e+76], N[(a + -0.3333333333333333), $MachinePrecision], t$95$0]]]
\begin{array}{l}
\\
\begin{array}{l}
t_0 := 0.3333333333333333 \cdot \left(rand \cdot \sqrt{a}\right)\\
\mathbf{if}\;rand \leq -1.3 \cdot 10^{+45}:\\
\;\;\;\;t\_0\\
\mathbf{elif}\;rand \leq 6.5 \cdot 10^{+76}:\\
\;\;\;\;a + -0.3333333333333333\\
\mathbf{else}:\\
\;\;\;\;t\_0\\
\end{array}
\end{array}
if rand < -1.30000000000000004e45 or 6.5000000000000005e76 < rand Initial program 99.6%
Taylor expanded in a around 0
sub-negN/A
*-commutativeN/A
metadata-evalN/A
rem-square-sqrtN/A
unpow2N/A
lower-fma.f64N/A
unpow2N/A
rem-square-sqrt99.6
Simplified99.6%
Taylor expanded in a around inf
lower-*.f64N/A
+-commutativeN/A
associate-*r*N/A
*-commutativeN/A
associate-*l*N/A
lower-fma.f64N/A
lower-sqrt.f64N/A
lower-/.f64N/A
*-commutativeN/A
lower-*.f6498.6
Simplified98.6%
Taylor expanded in a around 0
lower-*.f64N/A
lower-*.f64N/A
lower-sqrt.f6489.9
Simplified89.9%
if -1.30000000000000004e45 < rand < 6.5000000000000005e76Initial program 100.0%
Taylor expanded in a around 0
sub-negN/A
*-commutativeN/A
metadata-evalN/A
rem-square-sqrtN/A
unpow2N/A
lower-fma.f64N/A
unpow2N/A
rem-square-sqrt100.0
Simplified100.0%
Taylor expanded in rand around 0
sub-negN/A
metadata-evalN/A
lower-+.f6496.9
Simplified96.9%
Final simplification94.2%
(FPCore (a rand) :precision binary64 (fma rand (* 0.3333333333333333 (sqrt a)) (+ a -0.3333333333333333)))
double code(double a, double rand) {
return fma(rand, (0.3333333333333333 * sqrt(a)), (a + -0.3333333333333333));
}
function code(a, rand) return fma(rand, Float64(0.3333333333333333 * sqrt(a)), Float64(a + -0.3333333333333333)) end
code[a_, rand_] := N[(rand * N[(0.3333333333333333 * N[Sqrt[a], $MachinePrecision]), $MachinePrecision] + N[(a + -0.3333333333333333), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\mathsf{fma}\left(rand, 0.3333333333333333 \cdot \sqrt{a}, a + -0.3333333333333333\right)
\end{array}
Initial program 99.8%
Taylor expanded in a around 0
sub-negN/A
*-commutativeN/A
metadata-evalN/A
rem-square-sqrtN/A
unpow2N/A
lower-fma.f64N/A
unpow2N/A
rem-square-sqrt99.8
Simplified99.8%
Taylor expanded in rand around 0
+-commutativeN/A
associate--l+N/A
associate-*l*N/A
*-commutativeN/A
associate-*r*N/A
distribute-lft1-inN/A
rgt-mult-inverseN/A
distribute-lft-inN/A
lower-*.f64N/A
Simplified99.9%
Taylor expanded in rand around 0
+-commutativeN/A
associate--l+N/A
associate-*l*N/A
lower-fma.f64N/A
Simplified99.9%
Taylor expanded in a around inf
lower-*.f64N/A
lower-sqrt.f6499.1
Simplified99.1%
Final simplification99.1%
(FPCore (a rand) :precision binary64 (fma 0.3333333333333333 (* rand (sqrt a)) a))
double code(double a, double rand) {
return fma(0.3333333333333333, (rand * sqrt(a)), a);
}
function code(a, rand) return fma(0.3333333333333333, Float64(rand * sqrt(a)), a) end
code[a_, rand_] := N[(0.3333333333333333 * N[(rand * N[Sqrt[a], $MachinePrecision]), $MachinePrecision] + a), $MachinePrecision]
\begin{array}{l}
\\
\mathsf{fma}\left(0.3333333333333333, rand \cdot \sqrt{a}, a\right)
\end{array}
Initial program 99.8%
Taylor expanded in a around 0
sub-negN/A
*-commutativeN/A
metadata-evalN/A
rem-square-sqrtN/A
unpow2N/A
lower-fma.f64N/A
unpow2N/A
rem-square-sqrt99.8
Simplified99.8%
Taylor expanded in a around inf
lower-*.f64N/A
+-commutativeN/A
associate-*r*N/A
*-commutativeN/A
associate-*l*N/A
lower-fma.f64N/A
lower-sqrt.f64N/A
lower-/.f64N/A
*-commutativeN/A
lower-*.f6498.0
Simplified98.0%
Taylor expanded in a around 0
+-commutativeN/A
lower-fma.f64N/A
lower-*.f64N/A
lower-sqrt.f6498.0
Simplified98.0%
Final simplification98.0%
(FPCore (a rand) :precision binary64 (+ a -0.3333333333333333))
double code(double a, double rand) {
return a + -0.3333333333333333;
}
real(8) function code(a, rand)
real(8), intent (in) :: a
real(8), intent (in) :: rand
code = a + (-0.3333333333333333d0)
end function
public static double code(double a, double rand) {
return a + -0.3333333333333333;
}
def code(a, rand): return a + -0.3333333333333333
function code(a, rand) return Float64(a + -0.3333333333333333) end
function tmp = code(a, rand) tmp = a + -0.3333333333333333; end
code[a_, rand_] := N[(a + -0.3333333333333333), $MachinePrecision]
\begin{array}{l}
\\
a + -0.3333333333333333
\end{array}
Initial program 99.8%
Taylor expanded in a around 0
sub-negN/A
*-commutativeN/A
metadata-evalN/A
rem-square-sqrtN/A
unpow2N/A
lower-fma.f64N/A
unpow2N/A
rem-square-sqrt99.8
Simplified99.8%
Taylor expanded in rand around 0
sub-negN/A
metadata-evalN/A
lower-+.f6462.3
Simplified62.3%
(FPCore (a rand) :precision binary64 -0.3333333333333333)
double code(double a, double rand) {
return -0.3333333333333333;
}
real(8) function code(a, rand)
real(8), intent (in) :: a
real(8), intent (in) :: rand
code = -0.3333333333333333d0
end function
public static double code(double a, double rand) {
return -0.3333333333333333;
}
def code(a, rand): return -0.3333333333333333
function code(a, rand) return -0.3333333333333333 end
function tmp = code(a, rand) tmp = -0.3333333333333333; end
code[a_, rand_] := -0.3333333333333333
\begin{array}{l}
\\
-0.3333333333333333
\end{array}
Initial program 99.8%
Taylor expanded in a around 0
sub-negN/A
*-commutativeN/A
metadata-evalN/A
rem-square-sqrtN/A
unpow2N/A
lower-fma.f64N/A
unpow2N/A
rem-square-sqrt99.8
Simplified99.8%
Taylor expanded in rand around 0
sub-negN/A
metadata-evalN/A
lower-+.f6462.3
Simplified62.3%
Taylor expanded in a around 0
Simplified1.5%
herbie shell --seed 2024215
(FPCore (a rand)
:name "Octave 3.8, oct_fill_randg"
:precision binary64
(* (- a (/ 1.0 3.0)) (+ 1.0 (* (/ 1.0 (sqrt (* 9.0 (- a (/ 1.0 3.0))))) rand))))