
(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 6 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 (cbrt (* (pow (sin (* 2.0 (* PI u2))) 3.0) (pow (- (log1p (- u1))) 1.5))))
float code(float cosTheta_i, float u1, float u2) {
return cbrtf((powf(sinf((2.0f * (((float) M_PI) * u2))), 3.0f) * powf(-log1pf(-u1), 1.5f)));
}
function code(cosTheta_i, u1, u2) return cbrt(Float32((sin(Float32(Float32(2.0) * Float32(Float32(pi) * u2))) ^ Float32(3.0)) * (Float32(-log1p(Float32(-u1))) ^ Float32(1.5)))) end
\begin{array}{l}
\\
\sqrt[3]{{\sin \left(2 \cdot \left(\pi \cdot u2\right)\right)}^{3} \cdot {\left(-\mathsf{log1p}\left(-u1\right)\right)}^{1.5}}
\end{array}
Initial program 58.6%
sub-neg58.6%
log1p-def98.4%
associate-*l*98.4%
Simplified98.4%
expm1-log1p-u98.4%
Applied egg-rr98.4%
add-cube-cbrt98.1%
pow398.1%
Applied egg-rr98.1%
*-commutative98.1%
sin-298.0%
expm1-log1p-u98.0%
rem-cube-cbrt98.3%
expm1-log1p-u98.3%
rem-cube-cbrt98.3%
sin-298.4%
add-cbrt-cube98.4%
add-cbrt-cube98.4%
Applied egg-rr98.5%
Final simplification98.5%
(FPCore (cosTheta_i u1 u2) :precision binary32 (if (<= (* u2 (* 2.0 PI)) 0.0019000000320374966) (* (* PI (* 2.0 u2)) (sqrt (+ u1 (* 0.5 (* u1 u1))))) (* (sin (* 2.0 (* PI u2))) (sqrt u1))))
float code(float cosTheta_i, float u1, float u2) {
float tmp;
if ((u2 * (2.0f * ((float) M_PI))) <= 0.0019000000320374966f) {
tmp = (((float) M_PI) * (2.0f * u2)) * sqrtf((u1 + (0.5f * (u1 * u1))));
} else {
tmp = sinf((2.0f * (((float) M_PI) * u2))) * sqrtf(u1);
}
return tmp;
}
function code(cosTheta_i, u1, u2) tmp = Float32(0.0) if (Float32(u2 * Float32(Float32(2.0) * Float32(pi))) <= Float32(0.0019000000320374966)) tmp = Float32(Float32(Float32(pi) * Float32(Float32(2.0) * u2)) * sqrt(Float32(u1 + Float32(Float32(0.5) * Float32(u1 * u1))))); 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(2.0) * single(pi))) <= single(0.0019000000320374966)) tmp = (single(pi) * (single(2.0) * u2)) * sqrt((u1 + (single(0.5) * (u1 * u1)))); 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 \cdot \left(2 \cdot \pi\right) \leq 0.0019000000320374966:\\
\;\;\;\;\left(\pi \cdot \left(2 \cdot u2\right)\right) \cdot \sqrt{u1 + 0.5 \cdot \left(u1 \cdot u1\right)}\\
\mathbf{else}:\\
\;\;\;\;\sin \left(2 \cdot \left(\pi \cdot u2\right)\right) \cdot \sqrt{u1}\\
\end{array}
\end{array}
if (*.f32 (*.f32 2 (PI.f32)) u2) < 0.00190000003Initial program 57.6%
associate-*r*57.6%
add-sqr-sqrt57.6%
pow257.6%
Applied egg-rr57.6%
Taylor expanded in u1 around 0 88.1%
+-commutative88.1%
mul-1-neg88.1%
unsub-neg88.1%
*-commutative88.1%
unpow288.1%
associate-*l*88.1%
Simplified88.1%
Taylor expanded in u2 around 0 88.3%
associate-*r*88.3%
associate-*r*88.3%
*-commutative88.3%
cancel-sign-sub-inv88.3%
metadata-eval88.3%
unpow288.3%
Simplified88.3%
if 0.00190000003 < (*.f32 (*.f32 2 (PI.f32)) u2) Initial program 60.3%
sub-neg60.3%
log1p-def98.2%
associate-*l*98.2%
Simplified98.2%
log1p-udef60.3%
sub-neg60.3%
add-sqr-sqrt60.2%
pow260.2%
Applied egg-rr75.1%
Taylor expanded in u1 around 0 77.3%
Final simplification84.2%
(FPCore (cosTheta_i u1 u2) :precision binary32 (* (sin (* 2.0 (* PI u2))) (sqrt (- (log1p (- u1))))))
float code(float cosTheta_i, float u1, float u2) {
return sinf((2.0f * (((float) M_PI) * u2))) * sqrtf(-log1pf(-u1));
}
function code(cosTheta_i, u1, u2) return Float32(sin(Float32(Float32(2.0) * Float32(Float32(pi) * u2))) * sqrt(Float32(-log1p(Float32(-u1))))) end
\begin{array}{l}
\\
\sin \left(2 \cdot \left(\pi \cdot u2\right)\right) \cdot \sqrt{-\mathsf{log1p}\left(-u1\right)}
\end{array}
Initial program 58.6%
sub-neg58.6%
log1p-def98.4%
associate-*l*98.4%
Simplified98.4%
Final simplification98.4%
(FPCore (cosTheta_i u1 u2) :precision binary32 (* (sin (* PI (* 2.0 u2))) (sqrt (+ u1 (* 0.5 (* u1 u1))))))
float code(float cosTheta_i, float u1, float u2) {
return sinf((((float) M_PI) * (2.0f * u2))) * sqrtf((u1 + (0.5f * (u1 * u1))));
}
function code(cosTheta_i, u1, u2) return Float32(sin(Float32(Float32(pi) * Float32(Float32(2.0) * u2))) * sqrt(Float32(u1 + Float32(Float32(0.5) * Float32(u1 * u1))))) end
function tmp = code(cosTheta_i, u1, u2) tmp = sin((single(pi) * (single(2.0) * u2))) * sqrt((u1 + (single(0.5) * (u1 * u1)))); end
\begin{array}{l}
\\
\sin \left(\pi \cdot \left(2 \cdot u2\right)\right) \cdot \sqrt{u1 + 0.5 \cdot \left(u1 \cdot u1\right)}
\end{array}
Initial program 58.6%
associate-*r*58.6%
add-sqr-sqrt57.6%
pow257.6%
Applied egg-rr57.6%
Taylor expanded in u1 around 0 86.6%
+-commutative86.6%
mul-1-neg86.6%
unsub-neg86.6%
*-commutative86.6%
unpow286.6%
associate-*l*86.6%
Simplified86.6%
Taylor expanded in u2 around inf 88.6%
associate-*r*88.6%
*-commutative88.6%
cancel-sign-sub-inv88.6%
metadata-eval88.6%
unpow288.6%
Simplified88.6%
Final simplification88.6%
(FPCore (cosTheta_i u1 u2) :precision binary32 (* (* PI (* 2.0 u2)) (sqrt (+ u1 (* 0.5 (* u1 u1))))))
float code(float cosTheta_i, float u1, float u2) {
return (((float) M_PI) * (2.0f * u2)) * sqrtf((u1 + (0.5f * (u1 * u1))));
}
function code(cosTheta_i, u1, u2) return Float32(Float32(Float32(pi) * Float32(Float32(2.0) * u2)) * sqrt(Float32(u1 + Float32(Float32(0.5) * Float32(u1 * u1))))) end
function tmp = code(cosTheta_i, u1, u2) tmp = (single(pi) * (single(2.0) * u2)) * sqrt((u1 + (single(0.5) * (u1 * u1)))); end
\begin{array}{l}
\\
\left(\pi \cdot \left(2 \cdot u2\right)\right) \cdot \sqrt{u1 + 0.5 \cdot \left(u1 \cdot u1\right)}
\end{array}
Initial program 58.6%
associate-*r*58.6%
add-sqr-sqrt57.6%
pow257.6%
Applied egg-rr57.6%
Taylor expanded in u1 around 0 86.6%
+-commutative86.6%
mul-1-neg86.6%
unsub-neg86.6%
*-commutative86.6%
unpow286.6%
associate-*l*86.6%
Simplified86.6%
Taylor expanded in u2 around 0 76.7%
associate-*r*76.7%
associate-*r*76.7%
*-commutative76.7%
cancel-sign-sub-inv76.7%
metadata-eval76.7%
unpow276.7%
Simplified76.7%
Final simplification76.7%
(FPCore (cosTheta_i u1 u2) :precision binary32 (* u2 (* PI (sqrt (* u1 4.0)))))
float code(float cosTheta_i, float u1, float u2) {
return u2 * (((float) M_PI) * sqrtf((u1 * 4.0f)));
}
function code(cosTheta_i, u1, u2) return Float32(u2 * Float32(Float32(pi) * sqrt(Float32(u1 * Float32(4.0))))) end
function tmp = code(cosTheta_i, u1, u2) tmp = u2 * (single(pi) * sqrt((u1 * single(4.0)))); end
\begin{array}{l}
\\
u2 \cdot \left(\pi \cdot \sqrt{u1 \cdot 4}\right)
\end{array}
Initial program 58.6%
Taylor expanded in u1 around 0 76.9%
mul-1-neg76.9%
Simplified76.9%
Taylor expanded in u2 around 0 68.5%
associate-*r*68.5%
Simplified68.5%
Taylor expanded in u2 around 0 68.5%
*-commutative68.5%
associate-*r*68.5%
associate-*l*68.5%
*-commutative68.5%
*-commutative68.5%
Simplified68.5%
associate-*r*68.5%
associate-*l*68.5%
*-commutative68.5%
*-commutative68.5%
associate-*r*68.5%
rem-cube-cbrt68.3%
expm1-log1p-u68.3%
expm1-udef29.7%
Applied egg-rr29.7%
expm1-def68.5%
expm1-log1p68.5%
*-commutative68.5%
Simplified68.5%
Final simplification68.5%
herbie shell --seed 2023275
(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))))