
(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 9 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 (cbrt (* (pow (* 2.0 PI) 3.0) (pow u2 3.0))))))
float code(float cosTheta_i, float u1, float u2) {
return sqrtf(-log1pf(-u1)) * sinf(cbrtf((powf((2.0f * ((float) M_PI)), 3.0f) * powf(u2, 3.0f))));
}
function code(cosTheta_i, u1, u2) return Float32(sqrt(Float32(-log1p(Float32(-u1)))) * sin(cbrt(Float32((Float32(Float32(2.0) * Float32(pi)) ^ Float32(3.0)) * (u2 ^ Float32(3.0)))))) end
\begin{array}{l}
\\
\sqrt{-\mathsf{log1p}\left(-u1\right)} \cdot \sin \left(\sqrt[3]{{\left(2 \cdot \pi\right)}^{3} \cdot {u2}^{3}}\right)
\end{array}
Initial program 55.8%
sub-neg55.8%
log1p-define98.5%
Simplified98.5%
add-cbrt-cube98.5%
add-cbrt-cube98.5%
cbrt-unprod98.4%
pow398.4%
pow398.5%
Applied egg-rr98.5%
Final simplification98.5%
(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(Float32(2.0) * Float32(pi)) * u2))) end
\begin{array}{l}
\\
\sqrt{-\mathsf{log1p}\left(-u1\right)} \cdot \sin \left(\left(2 \cdot \pi\right) \cdot u2\right)
\end{array}
Initial program 55.8%
sub-neg55.8%
log1p-define98.5%
Simplified98.5%
Final simplification98.5%
(FPCore (cosTheta_i u1 u2)
:precision binary32
(let* ((t_0 (* (* 2.0 PI) u2)))
(if (<= t_0 0.001449999981559813)
(* (sqrt (- (log1p (- u1)))) (* 2.0 (* PI u2)))
(* (sin t_0) (sqrt (* u1 (- 1.0 (* u1 -0.5))))))))
float code(float cosTheta_i, float u1, float u2) {
float t_0 = (2.0f * ((float) M_PI)) * u2;
float tmp;
if (t_0 <= 0.001449999981559813f) {
tmp = sqrtf(-log1pf(-u1)) * (2.0f * (((float) M_PI) * u2));
} else {
tmp = sinf(t_0) * sqrtf((u1 * (1.0f - (u1 * -0.5f))));
}
return tmp;
}
function code(cosTheta_i, u1, u2) t_0 = Float32(Float32(Float32(2.0) * Float32(pi)) * u2) tmp = Float32(0.0) if (t_0 <= Float32(0.001449999981559813)) tmp = Float32(sqrt(Float32(-log1p(Float32(-u1)))) * Float32(Float32(2.0) * Float32(Float32(pi) * u2))); else tmp = Float32(sin(t_0) * sqrt(Float32(u1 * Float32(Float32(1.0) - Float32(u1 * Float32(-0.5)))))); end return tmp end
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \left(2 \cdot \pi\right) \cdot u2\\
\mathbf{if}\;t\_0 \leq 0.001449999981559813:\\
\;\;\;\;\sqrt{-\mathsf{log1p}\left(-u1\right)} \cdot \left(2 \cdot \left(\pi \cdot u2\right)\right)\\
\mathbf{else}:\\
\;\;\;\;\sin t\_0 \cdot \sqrt{u1 \cdot \left(1 - u1 \cdot -0.5\right)}\\
\end{array}
\end{array}
if (*.f32 (*.f32 #s(literal 2 binary32) (PI.f32)) u2) < 0.00144999998Initial program 57.6%
sub-neg57.6%
log1p-define98.8%
Simplified98.8%
add-exp-log93.6%
*-commutative93.6%
associate-*r*93.6%
Applied egg-rr93.6%
rem-exp-log98.8%
associate-*l*98.8%
*-commutative98.8%
associate-*l*98.8%
sin-298.7%
*-commutative98.7%
*-commutative98.7%
*-commutative98.7%
Applied egg-rr98.7%
Taylor expanded in u2 around 0 98.3%
if 0.00144999998 < (*.f32 (*.f32 #s(literal 2 binary32) (PI.f32)) u2) Initial program 52.5%
Taylor expanded in u1 around 0 92.0%
Final simplification96.1%
(FPCore (cosTheta_i u1 u2)
:precision binary32
(if (<= u1 0.03999999910593033)
(*
(sin (* (* 2.0 PI) u2))
(sqrt (* u1 (- 1.0 (* u1 (- (* u1 -0.3333333333333333) 0.5))))))
(* (sqrt (- (log1p (- u1)))) (* 2.0 (* PI u2)))))
float code(float cosTheta_i, float u1, float u2) {
float tmp;
if (u1 <= 0.03999999910593033f) {
tmp = sinf(((2.0f * ((float) M_PI)) * u2)) * sqrtf((u1 * (1.0f - (u1 * ((u1 * -0.3333333333333333f) - 0.5f)))));
} else {
tmp = sqrtf(-log1pf(-u1)) * (2.0f * (((float) M_PI) * u2));
}
return tmp;
}
function code(cosTheta_i, u1, u2) tmp = Float32(0.0) if (u1 <= Float32(0.03999999910593033)) tmp = Float32(sin(Float32(Float32(Float32(2.0) * Float32(pi)) * u2)) * sqrt(Float32(u1 * Float32(Float32(1.0) - Float32(u1 * Float32(Float32(u1 * Float32(-0.3333333333333333)) - Float32(0.5))))))); else tmp = Float32(sqrt(Float32(-log1p(Float32(-u1)))) * Float32(Float32(2.0) * Float32(Float32(pi) * u2))); end return tmp end
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;u1 \leq 0.03999999910593033:\\
\;\;\;\;\sin \left(\left(2 \cdot \pi\right) \cdot u2\right) \cdot \sqrt{u1 \cdot \left(1 - u1 \cdot \left(u1 \cdot -0.3333333333333333 - 0.5\right)\right)}\\
\mathbf{else}:\\
\;\;\;\;\sqrt{-\mathsf{log1p}\left(-u1\right)} \cdot \left(2 \cdot \left(\pi \cdot u2\right)\right)\\
\end{array}
\end{array}
if u1 < 0.0399999991Initial program 50.8%
Taylor expanded in u1 around 0 98.0%
if 0.0399999991 < u1 Initial program 97.5%
sub-neg97.5%
log1p-define98.5%
Simplified98.5%
add-exp-log93.1%
*-commutative93.1%
associate-*r*93.1%
Applied egg-rr93.1%
rem-exp-log98.5%
associate-*l*98.5%
*-commutative98.5%
associate-*l*98.5%
sin-298.8%
*-commutative98.8%
*-commutative98.8%
*-commutative98.8%
Applied egg-rr98.8%
Taylor expanded in u2 around 0 91.7%
Final simplification97.3%
(FPCore (cosTheta_i u1 u2) :precision binary32 (* (sin (* (* 2.0 PI) u2)) (sqrt (* u1 (- 1.0 (* u1 (- (* u1 (- (* u1 -0.25) 0.3333333333333333)) 0.5)))))))
float code(float cosTheta_i, float u1, float u2) {
return sinf(((2.0f * ((float) M_PI)) * u2)) * sqrtf((u1 * (1.0f - (u1 * ((u1 * ((u1 * -0.25f) - 0.3333333333333333f)) - 0.5f)))));
}
function code(cosTheta_i, u1, u2) return Float32(sin(Float32(Float32(Float32(2.0) * Float32(pi)) * u2)) * sqrt(Float32(u1 * Float32(Float32(1.0) - Float32(u1 * Float32(Float32(u1 * Float32(Float32(u1 * Float32(-0.25)) - Float32(0.3333333333333333))) - Float32(0.5))))))) end
function tmp = code(cosTheta_i, u1, u2) tmp = sin(((single(2.0) * single(pi)) * u2)) * sqrt((u1 * (single(1.0) - (u1 * ((u1 * ((u1 * single(-0.25)) - single(0.3333333333333333))) - single(0.5)))))); end
\begin{array}{l}
\\
\sin \left(\left(2 \cdot \pi\right) \cdot u2\right) \cdot \sqrt{u1 \cdot \left(1 - u1 \cdot \left(u1 \cdot \left(u1 \cdot -0.25 - 0.3333333333333333\right) - 0.5\right)\right)}
\end{array}
Initial program 55.8%
Taylor expanded in u1 around 0 94.9%
Final simplification94.9%
(FPCore (cosTheta_i u1 u2)
:precision binary32
(let* ((t_0 (* (* 2.0 PI) u2)))
(if (<= t_0 0.01549999974668026)
(* (sqrt (- (log1p (- u1)))) (* 2.0 (* PI u2)))
(* (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 (t_0 <= 0.01549999974668026f) {
tmp = sqrtf(-log1pf(-u1)) * (2.0f * (((float) M_PI) * u2));
} else {
tmp = sinf(t_0) * sqrtf(u1);
}
return tmp;
}
function code(cosTheta_i, u1, u2) t_0 = Float32(Float32(Float32(2.0) * Float32(pi)) * u2) tmp = Float32(0.0) if (t_0 <= Float32(0.01549999974668026)) tmp = Float32(sqrt(Float32(-log1p(Float32(-u1)))) * Float32(Float32(2.0) * Float32(Float32(pi) * u2))); else tmp = Float32(sin(t_0) * sqrt(u1)); end return tmp end
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \left(2 \cdot \pi\right) \cdot u2\\
\mathbf{if}\;t\_0 \leq 0.01549999974668026:\\
\;\;\;\;\sqrt{-\mathsf{log1p}\left(-u1\right)} \cdot \left(2 \cdot \left(\pi \cdot u2\right)\right)\\
\mathbf{else}:\\
\;\;\;\;\sin t\_0 \cdot \sqrt{u1}\\
\end{array}
\end{array}
if (*.f32 (*.f32 #s(literal 2 binary32) (PI.f32)) u2) < 0.0154999997Initial program 57.8%
sub-neg57.8%
log1p-define98.8%
Simplified98.8%
add-exp-log93.9%
*-commutative93.9%
associate-*r*93.9%
Applied egg-rr93.9%
rem-exp-log98.8%
associate-*l*98.8%
*-commutative98.8%
associate-*l*98.8%
sin-298.6%
*-commutative98.6%
*-commutative98.6%
*-commutative98.6%
Applied egg-rr98.6%
Taylor expanded in u2 around 0 96.6%
if 0.0154999997 < (*.f32 (*.f32 #s(literal 2 binary32) (PI.f32)) u2) Initial program 50.2%
sub-neg50.2%
log1p-define97.7%
Simplified97.7%
pow1/297.7%
log1p-undefine50.2%
sub-neg50.2%
pow-to-exp50.2%
add-sqr-sqrt50.2%
sqrt-unprod50.2%
sqr-neg50.2%
sqrt-unprod1.9%
add-sqr-sqrt1.9%
sub-neg1.9%
log1p-undefine-0.0%
add-sqr-sqrt-0.0%
sqrt-unprod78.9%
sqr-neg78.9%
sqrt-unprod78.9%
add-sqr-sqrt78.9%
Applied egg-rr78.9%
Taylor expanded in u1 around 0 82.1%
Final simplification92.7%
(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(Float32(2.0) * 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(\left(2 \cdot \pi\right) \cdot u2\right) \cdot \sqrt{u1}
\end{array}
Initial program 55.8%
sub-neg55.8%
log1p-define98.5%
Simplified98.5%
pow1/298.5%
log1p-undefine55.8%
sub-neg55.8%
pow-to-exp55.8%
add-sqr-sqrt55.8%
sqrt-unprod55.8%
sqr-neg55.8%
sqrt-unprod1.7%
add-sqr-sqrt1.7%
sub-neg1.7%
log1p-undefine-0.0%
add-sqr-sqrt-0.0%
sqrt-unprod74.9%
sqr-neg74.9%
sqrt-unprod74.9%
add-sqr-sqrt74.9%
Applied egg-rr74.9%
Taylor expanded in u1 around 0 78.3%
Final simplification78.3%
(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 55.8%
Taylor expanded in u1 around 0 -0.0%
associate-*r*-0.0%
unpow2-0.0%
rem-square-sqrt4.0%
*-commutative4.0%
associate-*l*4.0%
*-commutative4.0%
mul-1-neg4.0%
Simplified4.0%
Taylor expanded in u2 around 0 4.6%
associate-*r*4.6%
Simplified4.6%
Taylor expanded in u1 around 0 4.6%
Simplified4.6%
Final simplification4.6%
(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 55.8%
Taylor expanded in u1 around 0 -0.0%
associate-*r*-0.0%
unpow2-0.0%
rem-square-sqrt4.0%
*-commutative4.0%
associate-*l*4.0%
*-commutative4.0%
mul-1-neg4.0%
Simplified4.0%
Taylor expanded in u2 around 0 4.6%
associate-*r*4.6%
Simplified4.6%
pow14.6%
*-commutative4.6%
*-commutative4.6%
*-commutative4.6%
associate-*l*4.6%
add-sqr-sqrt-0.0%
sqrt-unprod67.3%
*-commutative67.3%
*-commutative67.3%
swap-sqr67.3%
add-sqr-sqrt67.3%
metadata-eval67.3%
Applied egg-rr67.3%
Simplified67.3%
Final simplification67.3%
herbie shell --seed 2024058
(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))))