
(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 8 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 61.1%
sub-neg61.1%
log1p-def98.3%
associate-*l*98.3%
Simplified98.3%
Final simplification98.3%
(FPCore (cosTheta_i u1 u2) :precision binary32 (if (<= (* u2 (* 2.0 PI)) 0.004000000189989805) (* (sqrt (- (log1p (- u1)))) (* 2.0 (* PI u2))) (* (sqrt (- u1 (* -0.5 (* u1 u1)))) (sin (* PI (+ u2 u2))))))
float code(float cosTheta_i, float u1, float u2) {
float tmp;
if ((u2 * (2.0f * ((float) M_PI))) <= 0.004000000189989805f) {
tmp = sqrtf(-log1pf(-u1)) * (2.0f * (((float) M_PI) * u2));
} else {
tmp = sqrtf((u1 - (-0.5f * (u1 * u1)))) * sinf((((float) M_PI) * (u2 + u2)));
}
return tmp;
}
function code(cosTheta_i, u1, u2) tmp = Float32(0.0) if (Float32(u2 * Float32(Float32(2.0) * Float32(pi))) <= Float32(0.004000000189989805)) tmp = Float32(sqrt(Float32(-log1p(Float32(-u1)))) * Float32(Float32(2.0) * Float32(Float32(pi) * u2))); else tmp = Float32(sqrt(Float32(u1 - Float32(Float32(-0.5) * Float32(u1 * u1)))) * sin(Float32(Float32(pi) * Float32(u2 + u2)))); end return tmp end
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;u2 \cdot \left(2 \cdot \pi\right) \leq 0.004000000189989805:\\
\;\;\;\;\sqrt{-\mathsf{log1p}\left(-u1\right)} \cdot \left(2 \cdot \left(\pi \cdot u2\right)\right)\\
\mathbf{else}:\\
\;\;\;\;\sqrt{u1 - -0.5 \cdot \left(u1 \cdot u1\right)} \cdot \sin \left(\pi \cdot \left(u2 + u2\right)\right)\\
\end{array}
\end{array}
if (*.f32 (*.f32 2 (PI.f32)) u2) < 0.00400000019Initial program 61.1%
sub-neg61.1%
log1p-def98.6%
associate-*l*98.6%
Simplified98.6%
add-sqr-sqrt97.9%
pow297.9%
Applied egg-rr97.9%
Taylor expanded in u2 around 0 97.9%
if 0.00400000019 < (*.f32 (*.f32 2 (PI.f32)) u2) Initial program 61.1%
associate-*r*61.1%
add-cube-cbrt60.9%
pow361.0%
Applied egg-rr61.0%
Taylor expanded in u1 around 0 85.8%
+-commutative85.8%
mul-1-neg85.8%
unsub-neg85.8%
*-commutative85.8%
unpow285.8%
associate-*l*85.8%
Simplified85.8%
Taylor expanded in u2 around inf 86.3%
*-commutative86.3%
unpow286.3%
count-286.3%
distribute-rgt-out86.3%
Simplified86.3%
Final simplification93.5%
(FPCore (cosTheta_i u1 u2)
:precision binary32
(let* ((t_0 (* 2.0 (* PI u2))))
(if (<= (* u2 (* 2.0 PI)) 0.02500000037252903)
(* (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))) <= 0.02500000037252903f) {
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(0.02500000037252903)) 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 0.02500000037252903:\\
\;\;\;\;\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) < 0.0250000004Initial program 61.2%
sub-neg61.2%
log1p-def98.5%
associate-*l*98.5%
Simplified98.5%
add-sqr-sqrt97.9%
pow297.9%
Applied egg-rr97.9%
Taylor expanded in u2 around 0 94.8%
if 0.0250000004 < (*.f32 (*.f32 2 (PI.f32)) u2) Initial program 60.9%
sub-neg60.9%
log1p-def97.9%
associate-*l*97.9%
Simplified97.9%
neg-mul-197.9%
log1p-udef60.9%
sub-neg60.9%
neg-mul-160.9%
add-sqr-sqrt61.0%
pow261.0%
Applied egg-rr73.3%
Taylor expanded in u1 around 0 75.5%
Final simplification89.5%
(FPCore (cosTheta_i u1 u2) :precision binary32 (if (<= u2 0.000699999975040555) (* PI (* (sqrt (- u1 (* -0.5 (* u1 u1)))) (+ u2 u2))) (* (sin (* 2.0 (* PI u2))) (sqrt u1))))
float code(float cosTheta_i, float u1, float u2) {
float tmp;
if (u2 <= 0.000699999975040555f) {
tmp = ((float) M_PI) * (sqrtf((u1 - (-0.5f * (u1 * u1)))) * (u2 + u2));
} else {
tmp = sinf((2.0f * (((float) M_PI) * u2))) * sqrtf(u1);
}
return tmp;
}
function code(cosTheta_i, u1, u2) tmp = Float32(0.0) if (u2 <= Float32(0.000699999975040555)) tmp = Float32(Float32(pi) * Float32(sqrt(Float32(u1 - Float32(Float32(-0.5) * Float32(u1 * u1)))) * Float32(u2 + u2))); else tmp = Float32(sin(Float32(Float32(2.0) * Float32(Float32(pi) * u2))) * sqrt(u1)); end return tmp end
function tmp_2 = code(cosTheta_i, u1, u2) tmp = single(0.0); if (u2 <= single(0.000699999975040555)) tmp = single(pi) * (sqrt((u1 - (single(-0.5) * (u1 * u1)))) * (u2 + u2)); else tmp = sin((single(2.0) * (single(pi) * u2))) * sqrt(u1); end tmp_2 = tmp; end
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;u2 \leq 0.000699999975040555:\\
\;\;\;\;\pi \cdot \left(\sqrt{u1 - -0.5 \cdot \left(u1 \cdot u1\right)} \cdot \left(u2 + u2\right)\right)\\
\mathbf{else}:\\
\;\;\;\;\sin \left(2 \cdot \left(\pi \cdot u2\right)\right) \cdot \sqrt{u1}\\
\end{array}
\end{array}
if u2 < 6.99999975e-4Initial program 61.3%
associate-*r*61.3%
add-cube-cbrt61.2%
pow361.2%
Applied egg-rr61.2%
Taylor expanded in u1 around 0 88.0%
+-commutative88.0%
mul-1-neg88.0%
unsub-neg88.0%
*-commutative88.0%
unpow288.0%
associate-*l*88.0%
Simplified88.0%
Taylor expanded in u2 around 0 88.1%
associate-*r*88.1%
associate-*r*88.1%
*-commutative88.1%
*-commutative88.1%
associate-*l*88.2%
*-commutative88.2%
rem-log-exp34.7%
log-pow34.8%
unpow234.8%
log-prod34.7%
rem-log-exp44.0%
rem-log-exp88.2%
unpow288.2%
Simplified88.2%
if 6.99999975e-4 < u2 Initial program 60.8%
sub-neg60.8%
log1p-def98.0%
associate-*l*98.0%
Simplified98.0%
neg-mul-198.0%
log1p-udef60.8%
sub-neg60.8%
neg-mul-160.8%
add-sqr-sqrt61.0%
pow261.0%
Applied egg-rr72.4%
Taylor expanded in u1 around 0 74.6%
Final simplification83.2%
(FPCore (cosTheta_i u1 u2) :precision binary32 (* PI (* (sqrt (- u1 (* -0.5 (* u1 u1)))) (+ u2 u2))))
float code(float cosTheta_i, float u1, float u2) {
return ((float) M_PI) * (sqrtf((u1 - (-0.5f * (u1 * u1)))) * (u2 + u2));
}
function code(cosTheta_i, u1, u2) return Float32(Float32(pi) * Float32(sqrt(Float32(u1 - Float32(Float32(-0.5) * Float32(u1 * u1)))) * Float32(u2 + u2))) end
function tmp = code(cosTheta_i, u1, u2) tmp = single(pi) * (sqrt((u1 - (single(-0.5) * (u1 * u1)))) * (u2 + u2)); end
\begin{array}{l}
\\
\pi \cdot \left(\sqrt{u1 - -0.5 \cdot \left(u1 \cdot u1\right)} \cdot \left(u2 + u2\right)\right)
\end{array}
Initial program 61.1%
associate-*r*61.1%
add-cube-cbrt61.0%
pow361.0%
Applied egg-rr61.0%
Taylor expanded in u1 around 0 87.1%
+-commutative87.1%
mul-1-neg87.1%
unsub-neg87.1%
*-commutative87.1%
unpow287.1%
associate-*l*87.1%
Simplified87.1%
Taylor expanded in u2 around 0 72.6%
associate-*r*72.6%
associate-*r*72.6%
*-commutative72.6%
*-commutative72.6%
associate-*l*72.7%
*-commutative72.7%
rem-log-exp39.0%
log-pow39.0%
unpow239.0%
log-prod39.0%
rem-log-exp44.9%
rem-log-exp72.7%
unpow272.7%
Simplified72.7%
Final simplification72.7%
(FPCore (cosTheta_i u1 u2) :precision binary32 (* u2 (* PI (* 2.0 (sqrt u1)))))
float code(float cosTheta_i, float u1, float u2) {
return u2 * (((float) M_PI) * (2.0f * sqrtf(u1)));
}
function code(cosTheta_i, u1, u2) return Float32(u2 * Float32(Float32(pi) * Float32(Float32(2.0) * sqrt(u1)))) end
function tmp = code(cosTheta_i, u1, u2) tmp = u2 * (single(pi) * (single(2.0) * sqrt(u1))); end
\begin{array}{l}
\\
u2 \cdot \left(\pi \cdot \left(2 \cdot \sqrt{u1}\right)\right)
\end{array}
Initial program 61.1%
Taylor expanded in u1 around 0 75.7%
mul-1-neg75.7%
Simplified75.7%
Taylor expanded in u2 around 0 64.6%
*-commutative64.6%
*-commutative64.6%
associate-*r*64.6%
*-commutative64.6%
Simplified64.6%
Taylor expanded in u2 around 0 64.6%
*-commutative64.6%
*-commutative64.6%
*-commutative64.6%
associate-*l*64.5%
associate-*l*64.5%
Simplified64.5%
Taylor expanded in u2 around 0 64.6%
associate-*r*64.6%
*-commutative64.6%
associate-*r*64.5%
*-commutative64.5%
associate-*l*64.5%
*-commutative64.5%
Simplified64.5%
Final simplification64.5%
(FPCore (cosTheta_i u1 u2) :precision binary32 (* PI (* 2.0 (* u2 (sqrt u1)))))
float code(float cosTheta_i, float u1, float u2) {
return ((float) M_PI) * (2.0f * (u2 * sqrtf(u1)));
}
function code(cosTheta_i, u1, u2) return Float32(Float32(pi) * Float32(Float32(2.0) * Float32(u2 * sqrt(u1)))) end
function tmp = code(cosTheta_i, u1, u2) tmp = single(pi) * (single(2.0) * (u2 * sqrt(u1))); end
\begin{array}{l}
\\
\pi \cdot \left(2 \cdot \left(u2 \cdot \sqrt{u1}\right)\right)
\end{array}
Initial program 61.1%
Taylor expanded in u1 around 0 75.7%
mul-1-neg75.7%
Simplified75.7%
Taylor expanded in u2 around 0 64.6%
*-commutative64.6%
*-commutative64.6%
associate-*r*64.6%
*-commutative64.6%
Simplified64.6%
Taylor expanded in u2 around 0 64.6%
*-commutative64.6%
*-commutative64.6%
*-commutative64.6%
associate-*l*64.5%
associate-*l*64.5%
Simplified64.5%
Final simplification64.5%
(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 61.1%
Taylor expanded in u1 around 0 75.7%
mul-1-neg75.7%
Simplified75.7%
Taylor expanded in u2 around 0 64.6%
*-commutative64.6%
*-commutative64.6%
associate-*r*64.6%
*-commutative64.6%
Simplified64.6%
Final simplification64.6%
herbie shell --seed 2023271
(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))))