
(FPCore (cosTheta_i u1 u2) :precision binary32 (* (sqrt (- (log (- 1.0 u1)))) (cos (* (* 2.0 PI) u2))))
float code(float cosTheta_i, float u1, float u2) {
return sqrtf(-logf((1.0f - u1))) * cosf(((2.0f * ((float) M_PI)) * u2));
}
function code(cosTheta_i, u1, u2) return Float32(sqrt(Float32(-log(Float32(Float32(1.0) - u1)))) * cos(Float32(Float32(Float32(2.0) * Float32(pi)) * u2))) end
function tmp = code(cosTheta_i, u1, u2) tmp = sqrt(-log((single(1.0) - u1))) * cos(((single(2.0) * single(pi)) * u2)); end
\begin{array}{l}
\\
\sqrt{-\log \left(1 - u1\right)} \cdot \cos \left(\left(2 \cdot \pi\right) \cdot u2\right)
\end{array}
Herbie found 10 alternatives:
| Alternative | Accuracy | Speedup |
|---|
(FPCore (cosTheta_i u1 u2) :precision binary32 (* (sqrt (- (log (- 1.0 u1)))) (cos (* (* 2.0 PI) u2))))
float code(float cosTheta_i, float u1, float u2) {
return sqrtf(-logf((1.0f - u1))) * cosf(((2.0f * ((float) M_PI)) * u2));
}
function code(cosTheta_i, u1, u2) return Float32(sqrt(Float32(-log(Float32(Float32(1.0) - u1)))) * cos(Float32(Float32(Float32(2.0) * Float32(pi)) * u2))) end
function tmp = code(cosTheta_i, u1, u2) tmp = sqrt(-log((single(1.0) - u1))) * cos(((single(2.0) * single(pi)) * u2)); end
\begin{array}{l}
\\
\sqrt{-\log \left(1 - u1\right)} \cdot \cos \left(\left(2 \cdot \pi\right) \cdot u2\right)
\end{array}
(FPCore (cosTheta_i u1 u2) :precision binary32 (* (sqrt (- (log1p (- u1)))) (cos (* (+ PI PI) u2))))
float code(float cosTheta_i, float u1, float u2) {
return sqrtf(-log1pf(-u1)) * cosf(((((float) M_PI) + ((float) M_PI)) * u2));
}
function code(cosTheta_i, u1, u2) return Float32(sqrt(Float32(-log1p(Float32(-u1)))) * cos(Float32(Float32(Float32(pi) + Float32(pi)) * u2))) end
\begin{array}{l}
\\
\sqrt{-\mathsf{log1p}\left(-u1\right)} \cdot \cos \left(\left(\pi + \pi\right) \cdot u2\right)
\end{array}
Initial program 57.9%
lift--.f32N/A
lift-log.f32N/A
negate-subN/A
lower-log1p.f32N/A
lower-neg.f3299.0
Applied rewrites99.0%
lift-PI.f32N/A
lift-*.f32N/A
count-2-revN/A
lift-+.f32N/A
lift-PI.f32N/A
lift-PI.f3299.0
Applied rewrites99.0%
(FPCore (cosTheta_i u1 u2)
:precision binary32
(if (<= u2 0.05000000074505806)
(*
(sqrt (- (log1p (- u1))))
(fma
(fma
(* 0.6666666666666666 (* u2 u2))
(* (* PI PI) (* PI PI))
(* (* PI PI) -2.0))
(* u2 u2)
1.0))
(* (sqrt (* (fma 0.5 u1 1.0) u1)) (cos (* (+ PI PI) u2)))))
float code(float cosTheta_i, float u1, float u2) {
float tmp;
if (u2 <= 0.05000000074505806f) {
tmp = sqrtf(-log1pf(-u1)) * fmaf(fmaf((0.6666666666666666f * (u2 * u2)), ((((float) M_PI) * ((float) M_PI)) * (((float) M_PI) * ((float) M_PI))), ((((float) M_PI) * ((float) M_PI)) * -2.0f)), (u2 * u2), 1.0f);
} else {
tmp = sqrtf((fmaf(0.5f, u1, 1.0f) * u1)) * cosf(((((float) M_PI) + ((float) M_PI)) * u2));
}
return tmp;
}
function code(cosTheta_i, u1, u2) tmp = Float32(0.0) if (u2 <= Float32(0.05000000074505806)) tmp = Float32(sqrt(Float32(-log1p(Float32(-u1)))) * fma(fma(Float32(Float32(0.6666666666666666) * Float32(u2 * u2)), Float32(Float32(Float32(pi) * Float32(pi)) * Float32(Float32(pi) * Float32(pi))), Float32(Float32(Float32(pi) * Float32(pi)) * Float32(-2.0))), Float32(u2 * u2), Float32(1.0))); else tmp = Float32(sqrt(Float32(fma(Float32(0.5), u1, Float32(1.0)) * u1)) * cos(Float32(Float32(Float32(pi) + Float32(pi)) * u2))); end return tmp end
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;u2 \leq 0.05000000074505806:\\
\;\;\;\;\sqrt{-\mathsf{log1p}\left(-u1\right)} \cdot \mathsf{fma}\left(\mathsf{fma}\left(0.6666666666666666 \cdot \left(u2 \cdot u2\right), \left(\pi \cdot \pi\right) \cdot \left(\pi \cdot \pi\right), \left(\pi \cdot \pi\right) \cdot -2\right), u2 \cdot u2, 1\right)\\
\mathbf{else}:\\
\;\;\;\;\sqrt{\mathsf{fma}\left(0.5, u1, 1\right) \cdot u1} \cdot \cos \left(\left(\pi + \pi\right) \cdot u2\right)\\
\end{array}
\end{array}
if u2 < 0.0500000007Initial program 57.9%
lift--.f32N/A
lift-log.f32N/A
negate-subN/A
lower-log1p.f32N/A
lower-neg.f3299.4
Applied rewrites99.4%
lift-PI.f32N/A
lift-*.f32N/A
count-2-revN/A
lift-+.f32N/A
lift-PI.f32N/A
lift-PI.f3299.4
Applied rewrites99.4%
Taylor expanded in u2 around 0
count-2-revN/A
+-commutativeN/A
*-commutativeN/A
lower-fma.f32N/A
Applied rewrites99.3%
if 0.0500000007 < u2 Initial program 58.0%
lift--.f32N/A
lift-log.f32N/A
negate-subN/A
lower-log1p.f32N/A
lower-neg.f3296.7
Applied rewrites96.7%
lift-PI.f32N/A
lift-*.f32N/A
count-2-revN/A
lift-+.f32N/A
lift-PI.f32N/A
lift-PI.f3296.7
Applied rewrites96.7%
Taylor expanded in u1 around 0
+-commutativeN/A
*-commutativeN/A
lift-fma.f32N/A
lift-*.f3285.8
Applied rewrites85.8%
(FPCore (cosTheta_i u1 u2)
:precision binary32
(if (<= u2 0.07000000029802322)
(*
(sqrt (- (log1p (- u1))))
(fma
(fma
(* 0.6666666666666666 (* u2 u2))
(* (* PI PI) (* PI PI))
(* (* PI PI) -2.0))
(* u2 u2)
1.0))
(* (sqrt u1) (cos (* (+ PI PI) u2)))))
float code(float cosTheta_i, float u1, float u2) {
float tmp;
if (u2 <= 0.07000000029802322f) {
tmp = sqrtf(-log1pf(-u1)) * fmaf(fmaf((0.6666666666666666f * (u2 * u2)), ((((float) M_PI) * ((float) M_PI)) * (((float) M_PI) * ((float) M_PI))), ((((float) M_PI) * ((float) M_PI)) * -2.0f)), (u2 * u2), 1.0f);
} else {
tmp = sqrtf(u1) * cosf(((((float) M_PI) + ((float) M_PI)) * u2));
}
return tmp;
}
function code(cosTheta_i, u1, u2) tmp = Float32(0.0) if (u2 <= Float32(0.07000000029802322)) tmp = Float32(sqrt(Float32(-log1p(Float32(-u1)))) * fma(fma(Float32(Float32(0.6666666666666666) * Float32(u2 * u2)), Float32(Float32(Float32(pi) * Float32(pi)) * Float32(Float32(pi) * Float32(pi))), Float32(Float32(Float32(pi) * Float32(pi)) * Float32(-2.0))), Float32(u2 * u2), Float32(1.0))); else tmp = Float32(sqrt(u1) * cos(Float32(Float32(Float32(pi) + Float32(pi)) * u2))); end return tmp end
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;u2 \leq 0.07000000029802322:\\
\;\;\;\;\sqrt{-\mathsf{log1p}\left(-u1\right)} \cdot \mathsf{fma}\left(\mathsf{fma}\left(0.6666666666666666 \cdot \left(u2 \cdot u2\right), \left(\pi \cdot \pi\right) \cdot \left(\pi \cdot \pi\right), \left(\pi \cdot \pi\right) \cdot -2\right), u2 \cdot u2, 1\right)\\
\mathbf{else}:\\
\;\;\;\;\sqrt{u1} \cdot \cos \left(\left(\pi + \pi\right) \cdot u2\right)\\
\end{array}
\end{array}
if u2 < 0.0700000003Initial program 57.8%
lift--.f32N/A
lift-log.f32N/A
negate-subN/A
lower-log1p.f32N/A
lower-neg.f3299.4
Applied rewrites99.4%
lift-PI.f32N/A
lift-*.f32N/A
count-2-revN/A
lift-+.f32N/A
lift-PI.f32N/A
lift-PI.f3299.4
Applied rewrites99.4%
Taylor expanded in u2 around 0
count-2-revN/A
+-commutativeN/A
*-commutativeN/A
lower-fma.f32N/A
Applied rewrites99.0%
if 0.0700000003 < u2 Initial program 58.6%
lift--.f32N/A
lift-log.f32N/A
negate-subN/A
lower-log1p.f32N/A
lower-neg.f3296.4
Applied rewrites96.4%
lift-PI.f32N/A
lift-*.f32N/A
count-2-revN/A
lift-+.f32N/A
lift-PI.f32N/A
lift-PI.f3296.4
Applied rewrites96.4%
Taylor expanded in u1 around 0
Applied rewrites74.5%
(FPCore (cosTheta_i u1 u2) :precision binary32 (if (<= (cos (* (* 2.0 PI) u2)) 0.9745000004768372) (* (sqrt u1) (cos (* (+ PI PI) u2))) (* (sqrt (- (log1p (- u1)))) (fma (* -2.0 (* u2 u2)) (* PI PI) 1.0))))
float code(float cosTheta_i, float u1, float u2) {
float tmp;
if (cosf(((2.0f * ((float) M_PI)) * u2)) <= 0.9745000004768372f) {
tmp = sqrtf(u1) * cosf(((((float) M_PI) + ((float) M_PI)) * u2));
} else {
tmp = sqrtf(-log1pf(-u1)) * fmaf((-2.0f * (u2 * u2)), (((float) M_PI) * ((float) M_PI)), 1.0f);
}
return tmp;
}
function code(cosTheta_i, u1, u2) tmp = Float32(0.0) if (cos(Float32(Float32(Float32(2.0) * Float32(pi)) * u2)) <= Float32(0.9745000004768372)) tmp = Float32(sqrt(u1) * cos(Float32(Float32(Float32(pi) + Float32(pi)) * u2))); else tmp = Float32(sqrt(Float32(-log1p(Float32(-u1)))) * fma(Float32(Float32(-2.0) * Float32(u2 * u2)), Float32(Float32(pi) * Float32(pi)), Float32(1.0))); end return tmp end
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;\cos \left(\left(2 \cdot \pi\right) \cdot u2\right) \leq 0.9745000004768372:\\
\;\;\;\;\sqrt{u1} \cdot \cos \left(\left(\pi + \pi\right) \cdot u2\right)\\
\mathbf{else}:\\
\;\;\;\;\sqrt{-\mathsf{log1p}\left(-u1\right)} \cdot \mathsf{fma}\left(-2 \cdot \left(u2 \cdot u2\right), \pi \cdot \pi, 1\right)\\
\end{array}
\end{array}
if (cos.f32 (*.f32 (*.f32 #s(literal 2 binary32) (PI.f32)) u2)) < 0.9745Initial program 57.6%
lift--.f32N/A
lift-log.f32N/A
negate-subN/A
lower-log1p.f32N/A
lower-neg.f3296.8
Applied rewrites96.8%
lift-PI.f32N/A
lift-*.f32N/A
count-2-revN/A
lift-+.f32N/A
lift-PI.f32N/A
lift-PI.f3296.8
Applied rewrites96.8%
Taylor expanded in u1 around 0
Applied rewrites75.4%
if 0.9745 < (cos.f32 (*.f32 (*.f32 #s(literal 2 binary32) (PI.f32)) u2)) Initial program 58.0%
lift--.f32N/A
lift-log.f32N/A
negate-subN/A
lower-log1p.f32N/A
lower-neg.f3299.4
Applied rewrites99.4%
Taylor expanded in u2 around 0
count-2-revN/A
+-commutativeN/A
associate-*r*N/A
lower-fma.f32N/A
lower-*.f32N/A
pow2N/A
lift-*.f32N/A
pow2N/A
lift-*.f32N/A
lift-PI.f32N/A
lift-PI.f3297.5
Applied rewrites97.5%
(FPCore (cosTheta_i u1 u2) :precision binary32 (* (sqrt (- (log1p (- u1)))) (fma (* -2.0 (* u2 u2)) (* PI PI) 1.0)))
float code(float cosTheta_i, float u1, float u2) {
return sqrtf(-log1pf(-u1)) * fmaf((-2.0f * (u2 * u2)), (((float) M_PI) * ((float) M_PI)), 1.0f);
}
function code(cosTheta_i, u1, u2) return Float32(sqrt(Float32(-log1p(Float32(-u1)))) * fma(Float32(Float32(-2.0) * Float32(u2 * u2)), Float32(Float32(pi) * Float32(pi)), Float32(1.0))) end
\begin{array}{l}
\\
\sqrt{-\mathsf{log1p}\left(-u1\right)} \cdot \mathsf{fma}\left(-2 \cdot \left(u2 \cdot u2\right), \pi \cdot \pi, 1\right)
\end{array}
Initial program 57.9%
lift--.f32N/A
lift-log.f32N/A
negate-subN/A
lower-log1p.f32N/A
lower-neg.f3299.0
Applied rewrites99.0%
Taylor expanded in u2 around 0
count-2-revN/A
+-commutativeN/A
associate-*r*N/A
lower-fma.f32N/A
lower-*.f32N/A
pow2N/A
lift-*.f32N/A
pow2N/A
lift-*.f32N/A
lift-PI.f32N/A
lift-PI.f3287.9
Applied rewrites87.9%
(FPCore (cosTheta_i u1 u2) :precision binary32 (* (sqrt (- (log1p (- u1)))) 1.0))
float code(float cosTheta_i, float u1, float u2) {
return sqrtf(-log1pf(-u1)) * 1.0f;
}
function code(cosTheta_i, u1, u2) return Float32(sqrt(Float32(-log1p(Float32(-u1)))) * Float32(1.0)) end
\begin{array}{l}
\\
\sqrt{-\mathsf{log1p}\left(-u1\right)} \cdot 1
\end{array}
Initial program 57.9%
lift--.f32N/A
lift-log.f32N/A
negate-subN/A
lower-log1p.f32N/A
lower-neg.f3299.0
Applied rewrites99.0%
Taylor expanded in u2 around 0
count-2-rev79.6
Applied rewrites79.6%
(FPCore (cosTheta_i u1 u2) :precision binary32 (if (<= u1 0.009999999776482582) (sqrt (* (fma (fma 0.3333333333333333 u1 0.5) u1 1.0) u1)) (sqrt (* (log (- 1.0 u1)) -1.0))))
float code(float cosTheta_i, float u1, float u2) {
float tmp;
if (u1 <= 0.009999999776482582f) {
tmp = sqrtf((fmaf(fmaf(0.3333333333333333f, u1, 0.5f), u1, 1.0f) * u1));
} else {
tmp = sqrtf((logf((1.0f - u1)) * -1.0f));
}
return tmp;
}
function code(cosTheta_i, u1, u2) tmp = Float32(0.0) if (u1 <= Float32(0.009999999776482582)) tmp = sqrt(Float32(fma(fma(Float32(0.3333333333333333), u1, Float32(0.5)), u1, Float32(1.0)) * u1)); else tmp = sqrt(Float32(log(Float32(Float32(1.0) - u1)) * Float32(-1.0))); end return tmp end
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;u1 \leq 0.009999999776482582:\\
\;\;\;\;\sqrt{\mathsf{fma}\left(\mathsf{fma}\left(0.3333333333333333, u1, 0.5\right), u1, 1\right) \cdot u1}\\
\mathbf{else}:\\
\;\;\;\;\sqrt{\log \left(1 - u1\right) \cdot -1}\\
\end{array}
\end{array}
if u1 < 0.00999999978Initial program 47.8%
Taylor expanded in u2 around 0
sqrt-unprodN/A
lower-sqrt.f32N/A
lower-*.f32N/A
lift-log.f32N/A
lift--.f3242.3
Applied rewrites42.3%
Taylor expanded in u1 around 0
*-commutativeN/A
lower-*.f32N/A
+-commutativeN/A
*-commutativeN/A
lower-fma.f32N/A
+-commutativeN/A
lower-fma.f3279.8
Applied rewrites79.8%
if 0.00999999978 < u1 Initial program 95.9%
Taylor expanded in u2 around 0
sqrt-unprodN/A
lower-sqrt.f32N/A
lower-*.f32N/A
lift-log.f32N/A
lift--.f3276.3
Applied rewrites76.3%
(FPCore (cosTheta_i u1 u2)
:precision binary32
(let* ((t_0 (log (- 1.0 u1))))
(if (<= (* (sqrt (- t_0)) (cos (* (* 2.0 PI) u2))) 0.05999999865889549)
(sqrt (* (fma 0.5 u1 1.0) u1))
(sqrt (* t_0 -1.0)))))
float code(float cosTheta_i, float u1, float u2) {
float t_0 = logf((1.0f - u1));
float tmp;
if ((sqrtf(-t_0) * cosf(((2.0f * ((float) M_PI)) * u2))) <= 0.05999999865889549f) {
tmp = sqrtf((fmaf(0.5f, u1, 1.0f) * u1));
} else {
tmp = sqrtf((t_0 * -1.0f));
}
return tmp;
}
function code(cosTheta_i, u1, u2) t_0 = log(Float32(Float32(1.0) - u1)) tmp = Float32(0.0) if (Float32(sqrt(Float32(-t_0)) * cos(Float32(Float32(Float32(2.0) * Float32(pi)) * u2))) <= Float32(0.05999999865889549)) tmp = sqrt(Float32(fma(Float32(0.5), u1, Float32(1.0)) * u1)); else tmp = sqrt(Float32(t_0 * Float32(-1.0))); end return tmp end
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \log \left(1 - u1\right)\\
\mathbf{if}\;\sqrt{-t\_0} \cdot \cos \left(\left(2 \cdot \pi\right) \cdot u2\right) \leq 0.05999999865889549:\\
\;\;\;\;\sqrt{\mathsf{fma}\left(0.5, u1, 1\right) \cdot u1}\\
\mathbf{else}:\\
\;\;\;\;\sqrt{t\_0 \cdot -1}\\
\end{array}
\end{array}
if (*.f32 (sqrt.f32 (neg.f32 (log.f32 (-.f32 #s(literal 1 binary32) u1)))) (cos.f32 (*.f32 (*.f32 #s(literal 2 binary32) (PI.f32)) u2))) < 0.0599999987Initial program 46.6%
Taylor expanded in u2 around 0
sqrt-unprodN/A
lower-sqrt.f32N/A
lower-*.f32N/A
lift-log.f32N/A
lift--.f3239.6
Applied rewrites39.6%
Taylor expanded in u1 around 0
*-commutativeN/A
lower-*.f32N/A
+-commutativeN/A
lower-fma.f3277.4
Applied rewrites77.4%
if 0.0599999987 < (*.f32 (sqrt.f32 (neg.f32 (log.f32 (-.f32 #s(literal 1 binary32) u1)))) (cos.f32 (*.f32 (*.f32 #s(literal 2 binary32) (PI.f32)) u2))) Initial program 94.9%
Taylor expanded in u2 around 0
sqrt-unprodN/A
lower-sqrt.f32N/A
lower-*.f32N/A
lift-log.f32N/A
lift--.f3281.6
Applied rewrites81.6%
(FPCore (cosTheta_i u1 u2) :precision binary32 (sqrt (* (fma 0.5 u1 1.0) u1)))
float code(float cosTheta_i, float u1, float u2) {
return sqrtf((fmaf(0.5f, u1, 1.0f) * u1));
}
function code(cosTheta_i, u1, u2) return sqrt(Float32(fma(Float32(0.5), u1, Float32(1.0)) * u1)) end
\begin{array}{l}
\\
\sqrt{\mathsf{fma}\left(0.5, u1, 1\right) \cdot u1}
\end{array}
Initial program 57.9%
Taylor expanded in u2 around 0
sqrt-unprodN/A
lower-sqrt.f32N/A
lower-*.f32N/A
lift-log.f32N/A
lift--.f3249.5
Applied rewrites49.5%
Taylor expanded in u1 around 0
*-commutativeN/A
lower-*.f32N/A
+-commutativeN/A
lower-fma.f3272.5
Applied rewrites72.5%
(FPCore (cosTheta_i u1 u2) :precision binary32 (sqrt u1))
float code(float cosTheta_i, float u1, float u2) {
return sqrtf(u1);
}
module fmin_fmax_functions
implicit none
private
public fmax
public fmin
interface fmax
module procedure fmax88
module procedure fmax44
module procedure fmax84
module procedure fmax48
end interface
interface fmin
module procedure fmin88
module procedure fmin44
module procedure fmin84
module procedure fmin48
end interface
contains
real(8) function fmax88(x, y) result (res)
real(8), intent (in) :: x
real(8), intent (in) :: y
res = merge(y, merge(x, max(x, y), y /= y), x /= x)
end function
real(4) function fmax44(x, y) result (res)
real(4), intent (in) :: x
real(4), intent (in) :: y
res = merge(y, merge(x, max(x, y), y /= y), x /= x)
end function
real(8) function fmax84(x, y) result(res)
real(8), intent (in) :: x
real(4), intent (in) :: y
res = merge(dble(y), merge(x, max(x, dble(y)), y /= y), x /= x)
end function
real(8) function fmax48(x, y) result(res)
real(4), intent (in) :: x
real(8), intent (in) :: y
res = merge(y, merge(dble(x), max(dble(x), y), y /= y), x /= x)
end function
real(8) function fmin88(x, y) result (res)
real(8), intent (in) :: x
real(8), intent (in) :: y
res = merge(y, merge(x, min(x, y), y /= y), x /= x)
end function
real(4) function fmin44(x, y) result (res)
real(4), intent (in) :: x
real(4), intent (in) :: y
res = merge(y, merge(x, min(x, y), y /= y), x /= x)
end function
real(8) function fmin84(x, y) result(res)
real(8), intent (in) :: x
real(4), intent (in) :: y
res = merge(dble(y), merge(x, min(x, dble(y)), y /= y), x /= x)
end function
real(8) function fmin48(x, y) result(res)
real(4), intent (in) :: x
real(8), intent (in) :: y
res = merge(y, merge(dble(x), min(dble(x), y), y /= y), x /= x)
end function
end module
real(4) function code(costheta_i, u1, u2)
use fmin_fmax_functions
real(4), intent (in) :: costheta_i
real(4), intent (in) :: u1
real(4), intent (in) :: u2
code = sqrt(u1)
end function
function code(cosTheta_i, u1, u2) return sqrt(u1) end
function tmp = code(cosTheta_i, u1, u2) tmp = sqrt(u1); end
\begin{array}{l}
\\
\sqrt{u1}
\end{array}
Initial program 57.9%
Taylor expanded in u2 around 0
sqrt-unprodN/A
lower-sqrt.f32N/A
lower-*.f32N/A
lift-log.f32N/A
lift--.f3249.5
Applied rewrites49.5%
Taylor expanded in u1 around 0
Applied rewrites64.5%
herbie shell --seed 2025119
(FPCore (cosTheta_i u1 u2)
:name "Beckmann Sample, near normal, slope_x"
:precision binary32
:pre (and (and (and (> cosTheta_i 0.9999) (<= cosTheta_i 1.0)) (and (<= 2.328306437e-10 u1) (<= u1 1.0))) (and (<= 2.328306437e-10 u2) (<= u2 1.0)))
(* (sqrt (- (log (- 1.0 u1)))) (cos (* (* 2.0 PI) u2))))