
(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 (cbrt (* (pow PI 3.0) (pow u2 3.0)))))))
float code(float cosTheta_i, float u1, float u2) {
return sqrtf(-log1pf(-u1)) * sinf((2.0f * cbrtf((powf(((float) M_PI), 3.0f) * powf(u2, 3.0f)))));
}
function code(cosTheta_i, u1, u2) return Float32(sqrt(Float32(-log1p(Float32(-u1)))) * sin(Float32(Float32(2.0) * cbrt(Float32((Float32(pi) ^ Float32(3.0)) * (u2 ^ Float32(3.0))))))) end
\begin{array}{l}
\\
\sqrt{-\mathsf{log1p}\left(-u1\right)} \cdot \sin \left(2 \cdot \sqrt[3]{{\pi}^{3} \cdot {u2}^{3}}\right)
\end{array}
Initial program 55.7%
sub-neg55.7%
log1p-def98.3%
associate-*l*98.3%
Simplified98.3%
add-cbrt-cube98.3%
add-cbrt-cube98.3%
cbrt-unprod98.3%
pow398.3%
pow398.4%
Applied egg-rr98.4%
Final simplification98.4%
(FPCore (cosTheta_i u1 u2) :precision binary32 (* (sqrt (- (log1p (- u1)))) (* 2.0 (* (sin (* PI u2)) (cos (* PI u2))))))
float code(float cosTheta_i, float u1, float u2) {
return sqrtf(-log1pf(-u1)) * (2.0f * (sinf((((float) M_PI) * u2)) * cosf((((float) M_PI) * u2))));
}
function code(cosTheta_i, u1, u2) return Float32(sqrt(Float32(-log1p(Float32(-u1)))) * Float32(Float32(2.0) * Float32(sin(Float32(Float32(pi) * u2)) * cos(Float32(Float32(pi) * u2))))) end
\begin{array}{l}
\\
\sqrt{-\mathsf{log1p}\left(-u1\right)} \cdot \left(2 \cdot \left(\sin \left(\pi \cdot u2\right) \cdot \cos \left(\pi \cdot u2\right)\right)\right)
\end{array}
Initial program 55.7%
sub-neg55.7%
log1p-def98.3%
associate-*l*98.3%
Simplified98.3%
add-cbrt-cube98.3%
add-cbrt-cube98.3%
cbrt-unprod98.3%
pow398.3%
pow398.4%
Applied egg-rr98.4%
pow-prod-down98.3%
rem-cbrt-cube98.3%
sin-298.3%
*-commutative98.3%
Applied egg-rr98.3%
Final simplification98.3%
(FPCore (cosTheta_i u1 u2) :precision binary32 (if (<= (* u2 (* 2.0 PI)) 0.02500000037252903) (* (sqrt (- (log1p (- u1)))) (* PI (+ u2 u2))) (* (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))) <= 0.02500000037252903f) {
tmp = sqrtf(-log1pf(-u1)) * (((float) M_PI) * (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 (Float32(u2 * Float32(Float32(2.0) * Float32(pi))) <= Float32(0.02500000037252903)) tmp = Float32(sqrt(Float32(-log1p(Float32(-u1)))) * Float32(Float32(pi) * Float32(u2 + u2))); else tmp = Float32(sin(Float32(Float32(2.0) * Float32(Float32(pi) * u2))) * sqrt(u1)); end return tmp end
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;u2 \cdot \left(2 \cdot \pi\right) \leq 0.02500000037252903:\\
\;\;\;\;\sqrt{-\mathsf{log1p}\left(-u1\right)} \cdot \left(\pi \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 (*.f32 (*.f32 2 (PI.f32)) u2) < 0.0250000004Initial program 56.1%
sub-neg56.1%
log1p-def98.5%
associate-*l*98.5%
Simplified98.5%
add-cbrt-cube98.5%
add-cbrt-cube98.5%
cbrt-unprod98.4%
pow398.4%
pow398.5%
Applied egg-rr98.5%
Taylor expanded in u2 around 0 95.4%
associate-*r*95.4%
count-295.4%
*-commutative95.4%
Simplified95.4%
if 0.0250000004 < (*.f32 (*.f32 2 (PI.f32)) u2) Initial program 54.5%
sub-neg54.5%
log1p-def97.8%
associate-*l*97.8%
Simplified97.8%
add-cbrt-cube97.7%
pow1/395.2%
Applied egg-rr76.3%
Taylor expanded in u1 around 0 79.9%
Final simplification91.3%
(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 55.7%
sub-neg55.7%
log1p-def98.3%
associate-*l*98.3%
Simplified98.3%
Final simplification98.3%
(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 55.7%
sub-neg55.7%
log1p-def98.3%
associate-*l*98.3%
Simplified98.3%
add-cbrt-cube98.3%
pow1/395.6%
Applied egg-rr74.0%
Taylor expanded in u1 around 0 77.7%
Final simplification77.7%
(FPCore (cosTheta_i u1 u2) :precision binary32 (* PI (* (+ u2 u2) (sqrt u1))))
float code(float cosTheta_i, float u1, float u2) {
return ((float) M_PI) * ((u2 + u2) * sqrtf(u1));
}
function code(cosTheta_i, u1, u2) return Float32(Float32(pi) * Float32(Float32(u2 + u2) * sqrt(u1))) end
function tmp = code(cosTheta_i, u1, u2) tmp = single(pi) * ((u2 + u2) * sqrt(u1)); end
\begin{array}{l}
\\
\pi \cdot \left(\left(u2 + u2\right) \cdot \sqrt{u1}\right)
\end{array}
Initial program 55.7%
Taylor expanded in u1 around 0 77.7%
mul-1-neg77.7%
Simplified77.7%
Taylor expanded in u2 around 0 66.6%
associate-*r*66.6%
associate-*r*66.6%
count-266.6%
*-commutative66.6%
Simplified66.6%
Taylor expanded in u2 around 0 66.6%
Simplified66.6%
Final simplification66.6%
(FPCore (cosTheta_i u1 u2) :precision binary32 (* (* PI (+ u2 u2)) (sqrt u1)))
float code(float cosTheta_i, float u1, float u2) {
return (((float) M_PI) * (u2 + u2)) * sqrtf(u1);
}
function code(cosTheta_i, u1, u2) return Float32(Float32(Float32(pi) * Float32(u2 + u2)) * sqrt(u1)) end
function tmp = code(cosTheta_i, u1, u2) tmp = (single(pi) * (u2 + u2)) * sqrt(u1); end
\begin{array}{l}
\\
\left(\pi \cdot \left(u2 + u2\right)\right) \cdot \sqrt{u1}
\end{array}
Initial program 55.7%
Taylor expanded in u1 around 0 77.7%
mul-1-neg77.7%
Simplified77.7%
Taylor expanded in u2 around 0 66.6%
associate-*r*66.6%
associate-*r*66.6%
count-266.6%
*-commutative66.6%
Simplified66.6%
Final simplification66.6%
(FPCore (cosTheta_i u1 u2) :precision binary32 (sqrt (* u1 (+ u2 u2))))
float code(float cosTheta_i, float u1, float u2) {
return sqrtf((u1 * (u2 + u2)));
}
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 = sqrt((u1 * (u2 + u2)))
end function
function code(cosTheta_i, u1, u2) return sqrt(Float32(u1 * Float32(u2 + u2))) end
function tmp = code(cosTheta_i, u1, u2) tmp = sqrt((u1 * (u2 + u2))); end
\begin{array}{l}
\\
\sqrt{u1 \cdot \left(u2 + u2\right)}
\end{array}
Initial program 55.7%
Taylor expanded in u1 around 0 77.7%
mul-1-neg77.7%
Simplified77.7%
Taylor expanded in u2 around 0 66.6%
associate-*r*66.6%
associate-*r*66.6%
count-266.6%
*-commutative66.6%
Simplified66.6%
Taylor expanded in u2 around 0 66.6%
Simplified66.6%
*-commutative66.6%
associate-*l*66.6%
*-commutative66.6%
flip-+-0.0%
+-inverses-0.0%
+-inverses-0.0%
associate-*r/-0.0%
+-inverses-0.0%
distribute-lft-out---0.0%
+-inverses-0.0%
+-inverses-0.0%
+-inverses-0.0%
flip-+25.4%
add-sqr-sqrt25.4%
sqrt-unprod25.4%
swap-sqr25.4%
add-sqr-sqrt25.4%
flip-+-0.0%
+-inverses-0.0%
+-inverses-0.0%
associate-*r/-0.0%
Applied egg-rr21.7%
Final simplification21.7%
herbie shell --seed 2023213
(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))))