
(FPCore (cosTheta_i u1 u2) :precision binary32 (* (sqrt (- (log (- 1.0 u1)))) (sin (* (* 2.0 PI) u2))))
float code(float cosTheta_i, float u1, float u2) {
return sqrtf(-logf((1.0f - u1))) * sinf(((2.0f * ((float) M_PI)) * u2));
}
function code(cosTheta_i, u1, u2) return Float32(sqrt(Float32(-log(Float32(Float32(1.0) - u1)))) * sin(Float32(Float32(Float32(2.0) * Float32(pi)) * u2))) end
function tmp = code(cosTheta_i, u1, u2) tmp = sqrt(-log((single(1.0) - u1))) * sin(((single(2.0) * single(pi)) * u2)); end
\begin{array}{l}
\\
\sqrt{-\log \left(1 - u1\right)} \cdot \sin \left(\left(2 \cdot \pi\right) \cdot u2\right)
\end{array}
Sampling outcomes in binary32 precision:
Herbie found 7 alternatives:
| Alternative | Accuracy | Speedup |
|---|
(FPCore (cosTheta_i u1 u2) :precision binary32 (* (sqrt (- (log (- 1.0 u1)))) (sin (* (* 2.0 PI) u2))))
float code(float cosTheta_i, float u1, float u2) {
return sqrtf(-logf((1.0f - u1))) * sinf(((2.0f * ((float) M_PI)) * u2));
}
function code(cosTheta_i, u1, u2) return Float32(sqrt(Float32(-log(Float32(Float32(1.0) - u1)))) * sin(Float32(Float32(Float32(2.0) * Float32(pi)) * u2))) end
function tmp = code(cosTheta_i, u1, u2) tmp = sqrt(-log((single(1.0) - u1))) * sin(((single(2.0) * single(pi)) * u2)); end
\begin{array}{l}
\\
\sqrt{-\log \left(1 - u1\right)} \cdot \sin \left(\left(2 \cdot \pi\right) \cdot u2\right)
\end{array}
(FPCore (cosTheta_i u1 u2) :precision binary32 (* (sqrt (- (log1p (- u1)))) (sin (* 2.0 (* PI u2)))))
float code(float cosTheta_i, float u1, float u2) {
return sqrtf(-log1pf(-u1)) * sinf((2.0f * (((float) M_PI) * u2)));
}
function code(cosTheta_i, u1, u2) return Float32(sqrt(Float32(-log1p(Float32(-u1)))) * sin(Float32(Float32(2.0) * Float32(Float32(pi) * u2)))) end
\begin{array}{l}
\\
\sqrt{-\mathsf{log1p}\left(-u1\right)} \cdot \sin \left(2 \cdot \left(\pi \cdot u2\right)\right)
\end{array}
Initial program 57.1%
sub-neg57.1%
log1p-def98.4%
associate-*l*98.4%
Simplified98.4%
Final simplification98.4%
(FPCore (cosTheta_i u1 u2)
:precision binary32
(let* ((t_0 (* u2 (* 2.0 PI))))
(if (<= t_0 0.0027000000700354576)
(* (sqrt (- (log1p (- u1)))) (* 2.0 (* PI u2)))
(* (sqrt (- u1 (* u1 (* u1 -0.5)))) (sin t_0)))))
float code(float cosTheta_i, float u1, float u2) {
float t_0 = u2 * (2.0f * ((float) M_PI));
float tmp;
if (t_0 <= 0.0027000000700354576f) {
tmp = sqrtf(-log1pf(-u1)) * (2.0f * (((float) M_PI) * u2));
} else {
tmp = sqrtf((u1 - (u1 * (u1 * -0.5f)))) * sinf(t_0);
}
return tmp;
}
function code(cosTheta_i, u1, u2) t_0 = Float32(u2 * Float32(Float32(2.0) * Float32(pi))) tmp = Float32(0.0) if (t_0 <= Float32(0.0027000000700354576)) tmp = Float32(sqrt(Float32(-log1p(Float32(-u1)))) * Float32(Float32(2.0) * Float32(Float32(pi) * u2))); else tmp = Float32(sqrt(Float32(u1 - Float32(u1 * Float32(u1 * Float32(-0.5))))) * sin(t_0)); end return tmp end
\begin{array}{l}
\\
\begin{array}{l}
t_0 := u2 \cdot \left(2 \cdot \pi\right)\\
\mathbf{if}\;t_0 \leq 0.0027000000700354576:\\
\;\;\;\;\sqrt{-\mathsf{log1p}\left(-u1\right)} \cdot \left(2 \cdot \left(\pi \cdot u2\right)\right)\\
\mathbf{else}:\\
\;\;\;\;\sqrt{u1 - u1 \cdot \left(u1 \cdot -0.5\right)} \cdot \sin t_0\\
\end{array}
\end{array}
if (*.f32 (*.f32 2 (PI.f32)) u2) < 0.00270000007Initial program 57.6%
sub-neg57.6%
log1p-def98.6%
associate-*l*98.6%
Simplified98.6%
add-cbrt-cube98.6%
add-cbrt-cube98.6%
cbrt-unprod98.6%
pow398.6%
pow398.7%
Applied egg-rr98.7%
Taylor expanded in u2 around 0 97.9%
if 0.00270000007 < (*.f32 (*.f32 2 (PI.f32)) u2) Initial program 56.4%
Taylor expanded in u1 around 0 86.9%
+-commutative86.9%
mul-1-neg86.9%
unsub-neg86.9%
unpow286.9%
associate-*r*86.9%
Simplified86.9%
Final simplification93.2%
(FPCore (cosTheta_i u1 u2)
:precision binary32
(let* ((t_0 (* 2.0 (* PI u2))))
(if (<= (* u2 (* 2.0 PI)) 0.006000000052154064)
(* (sqrt (- (log1p (- u1)))) t_0)
(* (sin t_0) (sqrt u1)))))
float code(float cosTheta_i, float u1, float u2) {
float t_0 = 2.0f * (((float) M_PI) * u2);
float tmp;
if ((u2 * (2.0f * ((float) M_PI))) <= 0.006000000052154064f) {
tmp = sqrtf(-log1pf(-u1)) * t_0;
} else {
tmp = sinf(t_0) * sqrtf(u1);
}
return tmp;
}
function code(cosTheta_i, u1, u2) t_0 = Float32(Float32(2.0) * Float32(Float32(pi) * u2)) tmp = Float32(0.0) if (Float32(u2 * Float32(Float32(2.0) * Float32(pi))) <= Float32(0.006000000052154064)) tmp = Float32(sqrt(Float32(-log1p(Float32(-u1)))) * t_0); else tmp = Float32(sin(t_0) * sqrt(u1)); end return tmp end
\begin{array}{l}
\\
\begin{array}{l}
t_0 := 2 \cdot \left(\pi \cdot u2\right)\\
\mathbf{if}\;u2 \cdot \left(2 \cdot \pi\right) \leq 0.006000000052154064:\\
\;\;\;\;\sqrt{-\mathsf{log1p}\left(-u1\right)} \cdot t_0\\
\mathbf{else}:\\
\;\;\;\;\sin t_0 \cdot \sqrt{u1}\\
\end{array}
\end{array}
if (*.f32 (*.f32 2 (PI.f32)) u2) < 0.00600000005Initial program 58.2%
sub-neg58.2%
log1p-def98.6%
associate-*l*98.6%
Simplified98.6%
add-cbrt-cube98.6%
add-cbrt-cube98.6%
cbrt-unprod98.6%
pow398.6%
pow398.7%
Applied egg-rr98.7%
Taylor expanded in u2 around 0 96.8%
if 0.00600000005 < (*.f32 (*.f32 2 (PI.f32)) u2) Initial program 55.3%
Taylor expanded in u1 around 0 76.4%
mul-1-neg76.4%
Simplified76.4%
Taylor expanded in u2 around inf 76.4%
Final simplification89.0%
(FPCore (cosTheta_i u1 u2) :precision binary32 (* (sin (* 2.0 (* PI u2))) (sqrt u1)))
float code(float cosTheta_i, float u1, float u2) {
return sinf((2.0f * (((float) M_PI) * u2))) * sqrtf(u1);
}
function code(cosTheta_i, u1, u2) return Float32(sin(Float32(Float32(2.0) * Float32(Float32(pi) * u2))) * sqrt(u1)) end
function tmp = code(cosTheta_i, u1, u2) tmp = sin((single(2.0) * (single(pi) * u2))) * sqrt(u1); end
\begin{array}{l}
\\
\sin \left(2 \cdot \left(\pi \cdot u2\right)\right) \cdot \sqrt{u1}
\end{array}
Initial program 57.1%
Taylor expanded in u1 around 0 76.1%
mul-1-neg76.1%
Simplified76.1%
Taylor expanded in u2 around inf 76.1%
Final simplification76.1%
(FPCore (cosTheta_i u1 u2) :precision binary32 (* 2.0 (* u2 (* PI (sqrt u1)))))
float code(float cosTheta_i, float u1, float u2) {
return 2.0f * (u2 * (((float) M_PI) * sqrtf(u1)));
}
function code(cosTheta_i, u1, u2) return Float32(Float32(2.0) * Float32(u2 * Float32(Float32(pi) * sqrt(u1)))) end
function tmp = code(cosTheta_i, u1, u2) tmp = single(2.0) * (u2 * (single(pi) * sqrt(u1))); end
\begin{array}{l}
\\
2 \cdot \left(u2 \cdot \left(\pi \cdot \sqrt{u1}\right)\right)
\end{array}
Initial program 57.1%
Taylor expanded in u1 around 0 76.1%
mul-1-neg76.1%
Simplified76.1%
Taylor expanded in u2 around 0 63.5%
associate-*r*63.5%
Simplified63.5%
Taylor expanded in u2 around 0 63.5%
*-commutative63.5%
associate-*r*63.4%
Simplified63.4%
Taylor expanded in u2 around 0 63.5%
associate-*l*63.4%
Simplified63.4%
Final simplification63.4%
(FPCore (cosTheta_i u1 u2) :precision binary32 (* (* 2.0 (* PI u2)) (sqrt u1)))
float code(float cosTheta_i, float u1, float u2) {
return (2.0f * (((float) M_PI) * u2)) * sqrtf(u1);
}
function code(cosTheta_i, u1, u2) return Float32(Float32(Float32(2.0) * Float32(Float32(pi) * u2)) * sqrt(u1)) end
function tmp = code(cosTheta_i, u1, u2) tmp = (single(2.0) * (single(pi) * u2)) * sqrt(u1); end
\begin{array}{l}
\\
\left(2 \cdot \left(\pi \cdot u2\right)\right) \cdot \sqrt{u1}
\end{array}
Initial program 57.1%
Taylor expanded in u1 around 0 76.1%
mul-1-neg76.1%
Simplified76.1%
Taylor expanded in u2 around 0 63.5%
associate-*r*63.5%
Simplified63.5%
Final simplification63.5%
(FPCore (cosTheta_i u1 u2) :precision binary32 0.0)
float code(float cosTheta_i, float u1, float u2) {
return 0.0f;
}
real(4) function code(costheta_i, u1, u2)
real(4), intent (in) :: costheta_i
real(4), intent (in) :: u1
real(4), intent (in) :: u2
code = 0.0e0
end function
function code(cosTheta_i, u1, u2) return Float32(0.0) end
function tmp = code(cosTheta_i, u1, u2) tmp = single(0.0); end
\begin{array}{l}
\\
0
\end{array}
Initial program 57.1%
associate-*r*57.1%
add-cube-cbrt57.0%
pow357.0%
Applied egg-rr57.0%
Taylor expanded in u2 around 0 7.1%
Final simplification7.1%
herbie shell --seed 2023200
(FPCore (cosTheta_i u1 u2)
:name "Beckmann Sample, near normal, slope_y"
: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)))) (sin (* (* 2.0 PI) u2))))