
(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 10 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 57.2%
sub-neg57.2%
log1p-define98.5%
Simplified98.5%
add-cbrt-cube98.5%
add-cbrt-cube98.5%
cbrt-unprod98.4%
pow398.4%
pow398.5%
Applied egg-rr98.5%
(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 57.2%
sub-neg57.2%
log1p-define98.5%
Simplified98.5%
(FPCore (cosTheta_i u1 u2)
:precision binary32
(let* ((t_0 (* (* 2.0 PI) u2)))
(if (<= t_0 0.0006000000284984708)
(* (sqrt (- (log1p (- u1)))) t_0)
(*
(sin t_0)
(sqrt (* u1 (+ 1.0 (* u1 (+ 0.5 (* u1 0.3333333333333333))))))))))
float code(float cosTheta_i, float u1, float u2) {
float t_0 = (2.0f * ((float) M_PI)) * u2;
float tmp;
if (t_0 <= 0.0006000000284984708f) {
tmp = sqrtf(-log1pf(-u1)) * t_0;
} else {
tmp = sinf(t_0) * sqrtf((u1 * (1.0f + (u1 * (0.5f + (u1 * 0.3333333333333333f))))));
}
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(0.0006000000284984708)) tmp = Float32(sqrt(Float32(-log1p(Float32(-u1)))) * t_0); else tmp = Float32(sin(t_0) * sqrt(Float32(u1 * Float32(Float32(1.0) + Float32(u1 * Float32(Float32(0.5) + Float32(u1 * Float32(0.3333333333333333)))))))); end return tmp end
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \left(2 \cdot \pi\right) \cdot u2\\
\mathbf{if}\;t\_0 \leq 0.0006000000284984708:\\
\;\;\;\;\sqrt{-\mathsf{log1p}\left(-u1\right)} \cdot t\_0\\
\mathbf{else}:\\
\;\;\;\;\sin t\_0 \cdot \sqrt{u1 \cdot \left(1 + u1 \cdot \left(0.5 + u1 \cdot 0.3333333333333333\right)\right)}\\
\end{array}
\end{array}
if (*.f32 (*.f32 #s(literal 2 binary32) (PI.f32)) u2) < 6.00000028e-4Initial program 57.9%
sub-neg57.9%
log1p-define98.8%
Simplified98.8%
add-cbrt-cube98.8%
add-cbrt-cube98.7%
cbrt-unprod98.7%
pow398.7%
pow398.8%
Applied egg-rr98.8%
Taylor expanded in u2 around 0 98.8%
associate-*r*98.8%
*-commutative98.8%
associate-*r*98.8%
Simplified98.8%
if 6.00000028e-4 < (*.f32 (*.f32 #s(literal 2 binary32) (PI.f32)) u2) Initial program 56.4%
Taylor expanded in u1 around 0 92.6%
*-commutative92.6%
Simplified92.6%
Final simplification96.1%
(FPCore (cosTheta_i u1 u2)
:precision binary32
(let* ((t_0 (* (* 2.0 PI) u2)))
(if (<= t_0 0.0007099999929778278)
(* (sqrt (- (log1p (- u1)))) t_0)
(* (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 <= 0.0007099999929778278f) {
tmp = sqrtf(-log1pf(-u1)) * t_0;
} 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(0.0007099999929778278)) tmp = Float32(sqrt(Float32(-log1p(Float32(-u1)))) * t_0); 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 0.0007099999929778278:\\
\;\;\;\;\sqrt{-\mathsf{log1p}\left(-u1\right)} \cdot t\_0\\
\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) < 7.09999993e-4Initial program 58.2%
sub-neg58.2%
log1p-define98.8%
Simplified98.8%
add-cbrt-cube98.8%
add-cbrt-cube98.7%
cbrt-unprod98.7%
pow398.7%
pow398.8%
Applied egg-rr98.8%
Taylor expanded in u2 around 0 98.7%
associate-*r*98.7%
*-commutative98.7%
associate-*r*98.7%
Simplified98.7%
if 7.09999993e-4 < (*.f32 (*.f32 #s(literal 2 binary32) (PI.f32)) u2) Initial program 55.8%
Taylor expanded in u1 around 0 89.5%
*-commutative89.5%
Simplified89.5%
Final simplification94.9%
(FPCore (cosTheta_i u1 u2) :precision binary32 (* (sin (* (* 2.0 PI) u2)) (sqrt (* u1 (+ 1.0 (* u1 (+ 0.5 (* u1 (+ 0.3333333333333333 (* u1 0.25))))))))))
float code(float cosTheta_i, float u1, float u2) {
return sinf(((2.0f * ((float) M_PI)) * u2)) * sqrtf((u1 * (1.0f + (u1 * (0.5f + (u1 * (0.3333333333333333f + (u1 * 0.25f))))))));
}
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(0.5) + Float32(u1 * Float32(Float32(0.3333333333333333) + Float32(u1 * Float32(0.25)))))))))) end
function tmp = code(cosTheta_i, u1, u2) tmp = sin(((single(2.0) * single(pi)) * u2)) * sqrt((u1 * (single(1.0) + (u1 * (single(0.5) + (u1 * (single(0.3333333333333333) + (u1 * single(0.25))))))))); end
\begin{array}{l}
\\
\sin \left(\left(2 \cdot \pi\right) \cdot u2\right) \cdot \sqrt{u1 \cdot \left(1 + u1 \cdot \left(0.5 + u1 \cdot \left(0.3333333333333333 + u1 \cdot 0.25\right)\right)\right)}
\end{array}
Initial program 57.2%
Taylor expanded in u1 around 0 94.3%
*-commutative94.3%
Simplified94.3%
Final simplification94.3%
(FPCore (cosTheta_i u1 u2)
:precision binary32
(let* ((t_0 (* (* 2.0 PI) u2)))
(if (<= t_0 0.006599999964237213)
(* (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 (t_0 <= 0.006599999964237213f) {
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(Float32(2.0) * Float32(pi)) * u2) tmp = Float32(0.0) if (t_0 <= Float32(0.006599999964237213)) 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 := \left(2 \cdot \pi\right) \cdot u2\\
\mathbf{if}\;t\_0 \leq 0.006599999964237213:\\
\;\;\;\;\sqrt{-\mathsf{log1p}\left(-u1\right)} \cdot t\_0\\
\mathbf{else}:\\
\;\;\;\;\sin t\_0 \cdot \sqrt{u1}\\
\end{array}
\end{array}
if (*.f32 (*.f32 #s(literal 2 binary32) (PI.f32)) u2) < 0.0066Initial program 58.9%
sub-neg58.9%
log1p-define98.8%
Simplified98.8%
add-cbrt-cube98.8%
add-cbrt-cube98.7%
cbrt-unprod98.6%
pow398.6%
pow398.8%
Applied egg-rr98.8%
Taylor expanded in u2 around 0 97.3%
associate-*r*97.3%
*-commutative97.3%
associate-*r*97.3%
Simplified97.3%
if 0.0066 < (*.f32 (*.f32 #s(literal 2 binary32) (PI.f32)) u2) Initial program 53.9%
Taylor expanded in u1 around 0 80.0%
Final simplification91.5%
(FPCore (cosTheta_i u1 u2)
:precision binary32
(let* ((t_0 (* (* 2.0 PI) u2)))
(if (<= t_0 0.005499999970197678)
(*
2.0
(*
(sqrt (* u1 (+ 1.0 (* u1 (+ 0.5 (* u1 0.3333333333333333))))))
(* 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 <= 0.005499999970197678f) {
tmp = 2.0f * (sqrtf((u1 * (1.0f + (u1 * (0.5f + (u1 * 0.3333333333333333f)))))) * (((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(0.005499999970197678)) tmp = Float32(Float32(2.0) * Float32(sqrt(Float32(u1 * Float32(Float32(1.0) + Float32(u1 * Float32(Float32(0.5) + Float32(u1 * Float32(0.3333333333333333))))))) * Float32(Float32(pi) * u2))); else tmp = Float32(sin(t_0) * sqrt(u1)); end return tmp end
function tmp_2 = code(cosTheta_i, u1, u2) t_0 = (single(2.0) * single(pi)) * u2; tmp = single(0.0); if (t_0 <= single(0.005499999970197678)) tmp = single(2.0) * (sqrt((u1 * (single(1.0) + (u1 * (single(0.5) + (u1 * single(0.3333333333333333))))))) * (single(pi) * u2)); else tmp = sin(t_0) * sqrt(u1); end tmp_2 = tmp; end
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \left(2 \cdot \pi\right) \cdot u2\\
\mathbf{if}\;t\_0 \leq 0.005499999970197678:\\
\;\;\;\;2 \cdot \left(\sqrt{u1 \cdot \left(1 + u1 \cdot \left(0.5 + u1 \cdot 0.3333333333333333\right)\right)} \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) < 0.00549999997Initial program 58.7%
Taylor expanded in u1 around 0 93.2%
*-commutative93.2%
Simplified93.2%
Taylor expanded in u2 around 0 92.4%
if 0.00549999997 < (*.f32 (*.f32 #s(literal 2 binary32) (PI.f32)) u2) Initial program 54.5%
Taylor expanded in u1 around 0 79.7%
Final simplification87.9%
(FPCore (cosTheta_i u1 u2) :precision binary32 (* 2.0 (* (sqrt (* u1 (+ 1.0 (* u1 (+ 0.5 (* u1 0.3333333333333333)))))) (* PI u2))))
float code(float cosTheta_i, float u1, float u2) {
return 2.0f * (sqrtf((u1 * (1.0f + (u1 * (0.5f + (u1 * 0.3333333333333333f)))))) * (((float) M_PI) * u2));
}
function code(cosTheta_i, u1, u2) return Float32(Float32(2.0) * Float32(sqrt(Float32(u1 * Float32(Float32(1.0) + Float32(u1 * Float32(Float32(0.5) + Float32(u1 * Float32(0.3333333333333333))))))) * Float32(Float32(pi) * u2))) end
function tmp = code(cosTheta_i, u1, u2) tmp = single(2.0) * (sqrt((u1 * (single(1.0) + (u1 * (single(0.5) + (u1 * single(0.3333333333333333))))))) * (single(pi) * u2)); end
\begin{array}{l}
\\
2 \cdot \left(\sqrt{u1 \cdot \left(1 + u1 \cdot \left(0.5 + u1 \cdot 0.3333333333333333\right)\right)} \cdot \left(\pi \cdot u2\right)\right)
\end{array}
Initial program 57.2%
Taylor expanded in u1 around 0 92.7%
*-commutative92.7%
Simplified92.7%
Taylor expanded in u2 around 0 76.5%
Final simplification76.5%
(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 57.2%
Taylor expanded in u1 around 0 78.5%
Taylor expanded in u2 around 0 66.2%
associate-*r*66.2%
Simplified66.2%
pow166.2%
*-commutative66.2%
associate-*l*66.3%
add-sqr-sqrt66.1%
sqrt-unprod66.3%
*-commutative66.3%
*-commutative66.3%
swap-sqr66.3%
add-sqr-sqrt66.3%
metadata-eval66.3%
Applied egg-rr66.3%
unpow166.3%
Simplified66.3%
(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 57.2%
Taylor expanded in u1 around 0 78.5%
Taylor expanded in u2 around 0 66.2%
associate-*r*66.2%
Simplified66.2%
pow166.2%
*-commutative66.2%
associate-*l*66.3%
add-sqr-sqrt66.1%
sqrt-unprod66.3%
*-commutative66.3%
*-commutative66.3%
swap-sqr66.3%
add-sqr-sqrt66.3%
metadata-eval66.3%
Applied egg-rr66.3%
unpow166.3%
Simplified66.3%
Taylor expanded in u2 around 0 66.2%
associate-*r*66.2%
Simplified66.2%
Final simplification66.2%
herbie shell --seed 2024172
(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))))