
(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 (let* ((t_0 (sqrt (* PI 2.0)))) (* (sqrt (- (log1p (- u1)))) (sin (* t_0 (* u2 t_0))))))
float code(float cosTheta_i, float u1, float u2) {
float t_0 = sqrtf((((float) M_PI) * 2.0f));
return sqrtf(-log1pf(-u1)) * sinf((t_0 * (u2 * t_0)));
}
function code(cosTheta_i, u1, u2) t_0 = sqrt(Float32(Float32(pi) * Float32(2.0))) return Float32(sqrt(Float32(-log1p(Float32(-u1)))) * sin(Float32(t_0 * Float32(u2 * t_0)))) end
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \sqrt{\pi \cdot 2}\\
\sqrt{-\mathsf{log1p}\left(-u1\right)} \cdot \sin \left(t\_0 \cdot \left(u2 \cdot t\_0\right)\right)
\end{array}
\end{array}
Initial program 61.1%
sub-neg61.1%
log1p-define98.3%
Simplified98.3%
expm1-log1p-u98.2%
expm1-undefine64.4%
associate-*l*64.4%
Applied egg-rr64.4%
expm1-define98.2%
associate-*r*98.2%
*-commutative98.2%
associate-*l*98.2%
Simplified98.2%
expm1-log1p-u98.3%
associate-*r*98.3%
*-commutative98.3%
*-commutative98.3%
add-sqr-sqrt98.3%
associate-*r*98.5%
*-commutative98.5%
*-commutative98.5%
Applied egg-rr98.5%
Final simplification98.5%
(FPCore (cosTheta_i u1 u2) :precision binary32 (* (sqrt (- (log1p (- u1)))) (sin (log1p (expm1 (* 2.0 (* u2 PI)))))))
float code(float cosTheta_i, float u1, float u2) {
return sqrtf(-log1pf(-u1)) * sinf(log1pf(expm1f((2.0f * (u2 * ((float) M_PI))))));
}
function code(cosTheta_i, u1, u2) return Float32(sqrt(Float32(-log1p(Float32(-u1)))) * sin(log1p(expm1(Float32(Float32(2.0) * Float32(u2 * Float32(pi))))))) end
\begin{array}{l}
\\
\sqrt{-\mathsf{log1p}\left(-u1\right)} \cdot \sin \left(\mathsf{log1p}\left(\mathsf{expm1}\left(2 \cdot \left(u2 \cdot \pi\right)\right)\right)\right)
\end{array}
Initial program 61.1%
sub-neg61.1%
log1p-define98.3%
Simplified98.3%
log1p-expm1-u98.4%
associate-*l*98.4%
Applied egg-rr98.4%
Final simplification98.4%
(FPCore (cosTheta_i u1 u2) :precision binary32 (* (sqrt (- (log1p (- u1)))) (sin (* u2 (* PI 2.0)))))
float code(float cosTheta_i, float u1, float u2) {
return sqrtf(-log1pf(-u1)) * sinf((u2 * (((float) M_PI) * 2.0f)));
}
function code(cosTheta_i, u1, u2) return Float32(sqrt(Float32(-log1p(Float32(-u1)))) * sin(Float32(u2 * Float32(Float32(pi) * Float32(2.0))))) end
\begin{array}{l}
\\
\sqrt{-\mathsf{log1p}\left(-u1\right)} \cdot \sin \left(u2 \cdot \left(\pi \cdot 2\right)\right)
\end{array}
Initial program 61.1%
sub-neg61.1%
log1p-define98.3%
Simplified98.3%
Final simplification98.3%
(FPCore (cosTheta_i u1 u2)
:precision binary32
(let* ((t_0 (* PI (* u2 2.0))))
(if (<= (* u2 (* PI 2.0)) 0.012000000104308128)
(* (sqrt (- (log1p (- u1)))) t_0)
(* (sqrt u1) (sin t_0)))))
float code(float cosTheta_i, float u1, float u2) {
float t_0 = ((float) M_PI) * (u2 * 2.0f);
float tmp;
if ((u2 * (((float) M_PI) * 2.0f)) <= 0.012000000104308128f) {
tmp = sqrtf(-log1pf(-u1)) * t_0;
} else {
tmp = sqrtf(u1) * sinf(t_0);
}
return tmp;
}
function code(cosTheta_i, u1, u2) t_0 = Float32(Float32(pi) * Float32(u2 * Float32(2.0))) tmp = Float32(0.0) if (Float32(u2 * Float32(Float32(pi) * Float32(2.0))) <= Float32(0.012000000104308128)) tmp = Float32(sqrt(Float32(-log1p(Float32(-u1)))) * t_0); else tmp = Float32(sqrt(u1) * sin(t_0)); end return tmp end
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \pi \cdot \left(u2 \cdot 2\right)\\
\mathbf{if}\;u2 \cdot \left(\pi \cdot 2\right) \leq 0.012000000104308128:\\
\;\;\;\;\sqrt{-\mathsf{log1p}\left(-u1\right)} \cdot t\_0\\
\mathbf{else}:\\
\;\;\;\;\sqrt{u1} \cdot \sin t\_0\\
\end{array}
\end{array}
if (*.f32 (*.f32 2 (PI.f32)) u2) < 0.0120000001Initial program 63.0%
sub-neg63.0%
log1p-define98.5%
Simplified98.5%
add-exp-log94.4%
associate-*l*94.4%
Applied egg-rr94.4%
Taylor expanded in u2 around 0 95.8%
associate-*r*95.8%
*-commutative95.8%
Simplified95.8%
if 0.0120000001 < (*.f32 (*.f32 2 (PI.f32)) u2) Initial program 57.0%
Taylor expanded in u1 around 0 75.6%
mul-1-neg75.6%
Simplified75.6%
Taylor expanded in u2 around inf 75.6%
associate-*r*75.6%
*-commutative75.6%
Simplified75.6%
Final simplification89.5%
(FPCore (cosTheta_i u1 u2) :precision binary32 (* (sqrt u1) (sin (* PI (* u2 2.0)))))
float code(float cosTheta_i, float u1, float u2) {
return sqrtf(u1) * sinf((((float) M_PI) * (u2 * 2.0f)));
}
function code(cosTheta_i, u1, u2) return Float32(sqrt(u1) * sin(Float32(Float32(pi) * Float32(u2 * Float32(2.0))))) end
function tmp = code(cosTheta_i, u1, u2) tmp = sqrt(u1) * sin((single(pi) * (u2 * single(2.0)))); end
\begin{array}{l}
\\
\sqrt{u1} \cdot \sin \left(\pi \cdot \left(u2 \cdot 2\right)\right)
\end{array}
Initial program 61.1%
Taylor expanded in u1 around 0 74.0%
mul-1-neg74.0%
Simplified74.0%
Taylor expanded in u2 around inf 74.0%
associate-*r*74.0%
*-commutative74.0%
Simplified74.0%
Final simplification74.0%
(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 61.1%
Taylor expanded in u1 around 0 74.0%
mul-1-neg74.0%
Simplified74.0%
Taylor expanded in u2 around 0 63.2%
associate-*r*63.2%
*-commutative63.2%
*-commutative63.2%
Simplified63.2%
Taylor expanded in u2 around 0 63.2%
*-commutative63.2%
associate-*r*63.2%
Simplified63.2%
Final simplification63.2%
(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(2.0) * Float32(Float32(pi) * Float32(u2 * sqrt(u1)))) end
function tmp = code(cosTheta_i, u1, u2) tmp = single(2.0) * (single(pi) * (u2 * sqrt(u1))); end
\begin{array}{l}
\\
2 \cdot \left(\pi \cdot \left(u2 \cdot \sqrt{u1}\right)\right)
\end{array}
Initial program 61.1%
Taylor expanded in u1 around 0 74.0%
mul-1-neg74.0%
Simplified74.0%
Taylor expanded in u2 around 0 63.2%
associate-*r*63.2%
*-commutative63.2%
*-commutative63.2%
Simplified63.2%
Final simplification63.2%
herbie shell --seed 2024050
(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))))