
(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 61.1%
sub-neg61.1%
log1p-define98.3%
Simplified98.3%
add-cbrt-cube98.3%
add-cbrt-cube98.4%
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 (log1p (expm1 (* 2.0 (* PI u2)))))))
float code(float cosTheta_i, float u1, float u2) {
return sqrtf(-log1pf(-u1)) * sinf(log1pf(expm1f((2.0f * (((float) M_PI) * u2)))));
}
function code(cosTheta_i, u1, u2) return Float32(sqrt(Float32(-log1p(Float32(-u1)))) * sin(log1p(expm1(Float32(Float32(2.0) * Float32(Float32(pi) * u2)))))) end
\begin{array}{l}
\\
\sqrt{-\mathsf{log1p}\left(-u1\right)} \cdot \sin \left(\mathsf{log1p}\left(\mathsf{expm1}\left(2 \cdot \left(\pi \cdot u2\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 (* (* 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 61.1%
sub-neg61.1%
log1p-define98.3%
Simplified98.3%
Final simplification98.3%
(FPCore (cosTheta_i u1 u2)
:precision binary32
(let* ((t_0 (* (* 2.0 PI) u2)))
(if (<= t_0 0.0024999999441206455)
(* (sqrt (- (log1p (- u1)))) (* PI (* 2.0 u2)))
(* (sin t_0) (sqrt (* u1 (- (* u1 (- -0.5)) -1.0)))))))
float code(float cosTheta_i, float u1, float u2) {
float t_0 = (2.0f * ((float) M_PI)) * u2;
float tmp;
if (t_0 <= 0.0024999999441206455f) {
tmp = sqrtf(-log1pf(-u1)) * (((float) M_PI) * (2.0f * u2));
} else {
tmp = sinf(t_0) * sqrtf((u1 * ((u1 * -(-0.5f)) - -1.0f)));
}
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(0.0024999999441206455)) tmp = Float32(sqrt(Float32(-log1p(Float32(-u1)))) * Float32(Float32(pi) * Float32(Float32(2.0) * u2))); else tmp = Float32(sin(t_0) * sqrt(Float32(u1 * Float32(Float32(u1 * Float32(-Float32(-0.5))) - Float32(-1.0))))); end return tmp end
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \left(2 \cdot \pi\right) \cdot u2\\
\mathbf{if}\;t\_0 \leq 0.0024999999441206455:\\
\;\;\;\;\sqrt{-\mathsf{log1p}\left(-u1\right)} \cdot \left(\pi \cdot \left(2 \cdot u2\right)\right)\\
\mathbf{else}:\\
\;\;\;\;\sin t\_0 \cdot \sqrt{u1 \cdot \left(u1 \cdot \left(--0.5\right) - -1\right)}\\
\end{array}
\end{array}
if (*.f32 (*.f32 2 (PI.f32)) u2) < 0.00249999994Initial program 64.1%
sub-neg64.1%
log1p-define98.5%
Simplified98.5%
log1p-expm1-u98.5%
associate-*l*98.5%
Applied egg-rr98.5%
log1p-expm1-u98.5%
*-commutative98.5%
sin-298.5%
*-commutative98.5%
*-commutative98.5%
Applied egg-rr98.5%
associate-*r*98.5%
*-commutative98.5%
*-commutative98.5%
Simplified98.5%
Taylor expanded in u2 around 0 97.7%
associate-*r*97.7%
*-commutative97.7%
*-commutative97.7%
*-commutative97.7%
Simplified97.7%
if 0.00249999994 < (*.f32 (*.f32 2 (PI.f32)) u2) Initial program 56.3%
Taylor expanded in u1 around 0 87.0%
*-commutative87.0%
*-commutative87.0%
unpow287.0%
associate-*l*87.0%
distribute-lft-out87.0%
Simplified87.0%
Final simplification93.6%
(FPCore (cosTheta_i u1 u2)
:precision binary32
(let* ((t_0 (* (* 2.0 PI) u2)))
(if (<= t_0 0.012000000104308128)
(* (sqrt (- (log1p (- u1)))) (* PI (* 2.0 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 <= 0.012000000104308128f) {
tmp = sqrtf(-log1pf(-u1)) * (((float) M_PI) * (2.0f * 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(0.012000000104308128)) tmp = Float32(sqrt(Float32(-log1p(Float32(-u1)))) * Float32(Float32(pi) * Float32(Float32(2.0) * 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 0.012000000104308128:\\
\;\;\;\;\sqrt{-\mathsf{log1p}\left(-u1\right)} \cdot \left(\pi \cdot \left(2 \cdot u2\right)\right)\\
\mathbf{else}:\\
\;\;\;\;\sin t\_0 \cdot \sqrt{u1}\\
\end{array}
\end{array}
if (*.f32 (*.f32 2 (PI.f32)) u2) < 0.0120000001Initial program 63.0%
sub-neg63.0%
log1p-define98.5%
Simplified98.5%
log1p-expm1-u98.5%
associate-*l*98.5%
Applied egg-rr98.5%
log1p-expm1-u98.5%
*-commutative98.5%
sin-298.5%
*-commutative98.5%
*-commutative98.5%
Applied egg-rr98.5%
associate-*r*98.5%
*-commutative98.5%
*-commutative98.5%
Simplified98.5%
Taylor expanded in u2 around 0 95.8%
associate-*r*95.8%
*-commutative95.8%
*-commutative95.8%
*-commutative95.8%
Simplified95.8%
if 0.0120000001 < (*.f32 (*.f32 2 (PI.f32)) u2) Initial program 57.0%
sub-neg57.0%
log1p-define98.0%
Simplified98.0%
pow1/298.0%
log1p-undefine57.0%
sub-neg57.0%
pow-to-exp56.9%
add-sqr-sqrt56.9%
sqrt-unprod56.9%
sqr-neg56.9%
sqrt-unprod1.7%
add-sqr-sqrt1.7%
sub-neg1.7%
log1p-undefine-0.0%
add-sqr-sqrt-0.0%
sqrt-unprod72.3%
sqr-neg72.3%
sqrt-unprod72.3%
add-sqr-sqrt72.3%
Applied egg-rr72.3%
Taylor expanded in u1 around 0 75.6%
Final simplification89.5%
(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 61.1%
sub-neg61.1%
log1p-define98.3%
Simplified98.3%
pow1/298.3%
log1p-undefine61.1%
sub-neg61.1%
pow-to-exp61.1%
add-sqr-sqrt61.1%
sqrt-unprod61.1%
sqr-neg61.1%
sqrt-unprod1.4%
add-sqr-sqrt1.4%
sub-neg1.4%
log1p-undefine-0.0%
add-sqr-sqrt-0.0%
sqrt-unprod70.9%
sqr-neg70.9%
sqrt-unprod70.9%
add-sqr-sqrt70.9%
Applied egg-rr70.9%
Taylor expanded in u1 around 0 74.0%
Final simplification74.0%
(FPCore (cosTheta_i u1 u2) :precision binary32 (* (* (* PI u2) (sqrt u1)) -2.0))
float code(float cosTheta_i, float u1, float u2) {
return ((((float) M_PI) * u2) * sqrtf(u1)) * -2.0f;
}
function code(cosTheta_i, u1, u2) return Float32(Float32(Float32(Float32(pi) * u2) * sqrt(u1)) * Float32(-2.0)) end
function tmp = code(cosTheta_i, u1, u2) tmp = ((single(pi) * u2) * sqrt(u1)) * single(-2.0); end
\begin{array}{l}
\\
\left(\left(\pi \cdot u2\right) \cdot \sqrt{u1}\right) \cdot -2
\end{array}
Initial program 61.1%
Taylor expanded in u1 around 0 -0.0%
associate-*r*-0.0%
unpow2-0.0%
rem-square-sqrt4.0%
*-commutative4.0%
*-commutative4.0%
associate-*l*4.0%
*-commutative4.0%
associate-*l*4.0%
associate-*r*4.0%
*-commutative4.0%
mul-1-neg4.0%
Simplified4.0%
Taylor expanded in u2 around 0 4.5%
Final simplification4.5%
(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%
sub-neg61.1%
log1p-define98.3%
Simplified98.3%
pow1/298.3%
log1p-undefine61.1%
sub-neg61.1%
pow-to-exp61.1%
add-sqr-sqrt61.1%
sqrt-unprod61.1%
sqr-neg61.1%
sqrt-unprod1.4%
add-sqr-sqrt1.4%
sub-neg1.4%
log1p-undefine-0.0%
add-sqr-sqrt-0.0%
sqrt-unprod70.9%
sqr-neg70.9%
sqrt-unprod70.9%
add-sqr-sqrt70.9%
Applied egg-rr70.9%
Taylor expanded in u2 around 0 39.2%
associate-*l*39.2%
log1p-define61.4%
Simplified61.4%
Taylor expanded in u1 around 0 63.2%
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(Float32(pi) * 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(\left(\pi \cdot u2\right) \cdot \sqrt{u1}\right)
\end{array}
Initial program 61.1%
sub-neg61.1%
log1p-define98.3%
Simplified98.3%
pow1/298.3%
log1p-undefine61.1%
sub-neg61.1%
pow-to-exp61.1%
add-sqr-sqrt61.1%
sqrt-unprod61.1%
sqr-neg61.1%
sqrt-unprod1.4%
add-sqr-sqrt1.4%
sub-neg1.4%
log1p-undefine-0.0%
add-sqr-sqrt-0.0%
sqrt-unprod70.9%
sqr-neg70.9%
sqrt-unprod70.9%
add-sqr-sqrt70.9%
Applied egg-rr70.9%
Taylor expanded in u2 around 0 39.2%
associate-*l*39.2%
log1p-define61.4%
Simplified61.4%
Taylor expanded in u1 around 0 63.2%
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))))