
(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 (pow (cbrt (* PI 2.0)) 2.0) 3.0) (* PI 2.0)) (pow u2 3.0))))))
float code(float cosTheta_i, float u1, float u2) {
return sqrtf(-log1pf(-u1)) * sinf(cbrtf(((powf(powf(cbrtf((((float) M_PI) * 2.0f)), 2.0f), 3.0f) * (((float) M_PI) * 2.0f)) * powf(u2, 3.0f))));
}
function code(cosTheta_i, u1, u2) return Float32(sqrt(Float32(-log1p(Float32(-u1)))) * sin(cbrt(Float32(Float32(((cbrt(Float32(Float32(pi) * Float32(2.0))) ^ Float32(2.0)) ^ Float32(3.0)) * Float32(Float32(pi) * Float32(2.0))) * (u2 ^ Float32(3.0)))))) end
\begin{array}{l}
\\
\sqrt{-\mathsf{log1p}\left(-u1\right)} \cdot \sin \left(\sqrt[3]{\left({\left({\left(\sqrt[3]{\pi \cdot 2}\right)}^{2}\right)}^{3} \cdot \left(\pi \cdot 2\right)\right) \cdot {u2}^{3}}\right)
\end{array}
Initial program 56.8%
sub-neg56.8%
log1p-define98.4%
Simplified98.4%
add-cbrt-cube98.4%
add-cbrt-cube98.3%
cbrt-unprod98.3%
pow398.3%
pow398.4%
Applied egg-rr98.4%
add-cube-cbrt98.4%
unpow-prod-down98.6%
pow298.6%
*-commutative98.6%
pow398.6%
add-cube-cbrt98.6%
*-commutative98.6%
Applied egg-rr98.6%
Final simplification98.6%
(FPCore (cosTheta_i u1 u2) :precision binary32 (* (sqrt (- (log1p (- u1)))) (sin (cbrt (* (pow u2 3.0) (pow (* PI 2.0) 3.0))))))
float code(float cosTheta_i, float u1, float u2) {
return sqrtf(-log1pf(-u1)) * sinf(cbrtf((powf(u2, 3.0f) * powf((((float) M_PI) * 2.0f), 3.0f))));
}
function code(cosTheta_i, u1, u2) return Float32(sqrt(Float32(-log1p(Float32(-u1)))) * sin(cbrt(Float32((u2 ^ Float32(3.0)) * (Float32(Float32(pi) * Float32(2.0)) ^ Float32(3.0)))))) end
\begin{array}{l}
\\
\sqrt{-\mathsf{log1p}\left(-u1\right)} \cdot \sin \left(\sqrt[3]{{u2}^{3} \cdot {\left(\pi \cdot 2\right)}^{3}}\right)
\end{array}
Initial program 56.8%
sub-neg56.8%
log1p-define98.4%
Simplified98.4%
add-cbrt-cube98.4%
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)))) (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 56.8%
sub-neg56.8%
log1p-define98.4%
Simplified98.4%
Final simplification98.4%
(FPCore (cosTheta_i u1 u2)
:precision binary32
(let* ((t_0 (* u2 (* PI 2.0))))
(if (<= t_0 0.0013500000350177288)
(* (sqrt (- (log1p (- u1)))) (* 2.0 (* PI u2)))
(*
(sin t_0)
(sqrt
(*
u1
(+ 1.0 (* u1 (+ 0.5 (* u1 (- 0.3333333333333333 (* u1 -0.25))))))))))))
float code(float cosTheta_i, float u1, float u2) {
float t_0 = u2 * (((float) M_PI) * 2.0f);
float tmp;
if (t_0 <= 0.0013500000350177288f) {
tmp = sqrtf(-log1pf(-u1)) * (2.0f * (((float) M_PI) * u2));
} else {
tmp = sinf(t_0) * sqrtf((u1 * (1.0f + (u1 * (0.5f + (u1 * (0.3333333333333333f - (u1 * -0.25f))))))));
}
return tmp;
}
function code(cosTheta_i, u1, u2) t_0 = Float32(u2 * Float32(Float32(pi) * Float32(2.0))) tmp = Float32(0.0) if (t_0 <= Float32(0.0013500000350177288)) 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(Float32(0.5) + Float32(u1 * Float32(Float32(0.3333333333333333) - Float32(u1 * Float32(-0.25)))))))))); end return tmp end
\begin{array}{l}
\\
\begin{array}{l}
t_0 := u2 \cdot \left(\pi \cdot 2\right)\\
\mathbf{if}\;t\_0 \leq 0.0013500000350177288:\\
\;\;\;\;\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 \left(0.5 + u1 \cdot \left(0.3333333333333333 - u1 \cdot -0.25\right)\right)\right)}\\
\end{array}
\end{array}
if (*.f32 (*.f32 #s(literal 2 binary32) (PI.f32)) u2) < 0.00135000004Initial program 57.2%
sub-neg57.2%
log1p-define98.7%
Simplified98.7%
add-cbrt-cube98.7%
pow1/392.4%
pow392.4%
*-commutative92.4%
associate-*r*92.4%
Applied egg-rr92.4%
Taylor expanded in u2 around 0 98.6%
if 0.00135000004 < (*.f32 (*.f32 #s(literal 2 binary32) (PI.f32)) u2) Initial program 56.1%
Taylor expanded in u1 around 0 93.1%
Final simplification96.7%
(FPCore (cosTheta_i u1 u2)
:precision binary32
(let* ((t_0 (* u2 (* PI 2.0))))
(if (<= t_0 0.0013500000350177288)
(* (sqrt (- (log1p (- u1)))) (* 2.0 (* PI u2)))
(*
(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 = u2 * (((float) M_PI) * 2.0f);
float tmp;
if (t_0 <= 0.0013500000350177288f) {
tmp = sqrtf(-log1pf(-u1)) * (2.0f * (((float) M_PI) * u2));
} 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(u2 * Float32(Float32(pi) * Float32(2.0))) tmp = Float32(0.0) if (t_0 <= Float32(0.0013500000350177288)) 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(Float32(0.5) - Float32(u1 * Float32(-0.3333333333333333)))))))); end return tmp end
\begin{array}{l}
\\
\begin{array}{l}
t_0 := u2 \cdot \left(\pi \cdot 2\right)\\
\mathbf{if}\;t\_0 \leq 0.0013500000350177288:\\
\;\;\;\;\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 \left(0.5 - u1 \cdot -0.3333333333333333\right)\right)}\\
\end{array}
\end{array}
if (*.f32 (*.f32 #s(literal 2 binary32) (PI.f32)) u2) < 0.00135000004Initial program 57.2%
sub-neg57.2%
log1p-define98.7%
Simplified98.7%
add-cbrt-cube98.7%
pow1/392.4%
pow392.4%
*-commutative92.4%
associate-*r*92.4%
Applied egg-rr92.4%
Taylor expanded in u2 around 0 98.6%
if 0.00135000004 < (*.f32 (*.f32 #s(literal 2 binary32) (PI.f32)) u2) Initial program 56.1%
Taylor expanded in u1 around 0 91.4%
Final simplification96.0%
(FPCore (cosTheta_i u1 u2)
:precision binary32
(let* ((t_0 (* u2 (* PI 2.0))))
(if (<= t_0 0.007499999832361937)
(* (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 = u2 * (((float) M_PI) * 2.0f);
float tmp;
if (t_0 <= 0.007499999832361937f) {
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(u2 * Float32(Float32(pi) * Float32(2.0))) tmp = Float32(0.0) if (t_0 <= Float32(0.007499999832361937)) 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 := u2 \cdot \left(\pi \cdot 2\right)\\
\mathbf{if}\;t\_0 \leq 0.007499999832361937:\\
\;\;\;\;\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) < 0.00749999983Initial program 57.3%
sub-neg57.3%
log1p-define98.6%
Simplified98.6%
add-cbrt-cube98.6%
pow1/392.8%
pow392.8%
*-commutative92.8%
associate-*r*92.8%
Applied egg-rr92.8%
Taylor expanded in u2 around 0 97.3%
if 0.00749999983 < (*.f32 (*.f32 #s(literal 2 binary32) (PI.f32)) u2) Initial program 55.6%
Taylor expanded in u1 around 0 88.9%
Final simplification95.0%
(FPCore (cosTheta_i u1 u2)
:precision binary32
(let* ((t_0 (* 2.0 (* PI u2))))
(if (<= (* u2 (* PI 2.0)) 0.04500000178813934)
(* (sqrt (- (log1p (- u1)))) t_0)
(* (sqrt u1) (sin t_0)))))
float code(float cosTheta_i, float u1, float u2) {
float t_0 = 2.0f * (((float) M_PI) * u2);
float tmp;
if ((u2 * (((float) M_PI) * 2.0f)) <= 0.04500000178813934f) {
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(2.0) * Float32(Float32(pi) * u2)) tmp = Float32(0.0) if (Float32(u2 * Float32(Float32(pi) * Float32(2.0))) <= Float32(0.04500000178813934)) 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 := 2 \cdot \left(\pi \cdot u2\right)\\
\mathbf{if}\;u2 \cdot \left(\pi \cdot 2\right) \leq 0.04500000178813934:\\
\;\;\;\;\sqrt{-\mathsf{log1p}\left(-u1\right)} \cdot t\_0\\
\mathbf{else}:\\
\;\;\;\;\sqrt{u1} \cdot \sin t\_0\\
\end{array}
\end{array}
if (*.f32 (*.f32 #s(literal 2 binary32) (PI.f32)) u2) < 0.0450000018Initial program 58.4%
sub-neg58.4%
log1p-define98.6%
Simplified98.6%
add-cbrt-cube98.6%
pow1/393.1%
pow393.1%
*-commutative93.1%
associate-*r*93.1%
Applied egg-rr93.1%
Taylor expanded in u2 around 0 95.5%
if 0.0450000018 < (*.f32 (*.f32 #s(literal 2 binary32) (PI.f32)) u2) Initial program 51.0%
Taylor expanded in u1 around 0 -0.0%
associate-*r*-0.0%
unpow2-0.0%
rem-square-sqrt3.6%
*-commutative3.6%
associate-*l*3.6%
*-commutative3.6%
mul-1-neg3.6%
Simplified3.6%
expm1-log1p-u3.6%
expm1-undefine3.6%
*-commutative3.6%
add-sqr-sqrt-0.0%
sqrt-unprod61.7%
sqr-neg61.7%
add-sqr-sqrt61.7%
associate-*r*61.7%
*-commutative61.7%
*-commutative61.7%
*-commutative61.7%
Applied egg-rr61.7%
sub-neg61.7%
metadata-eval61.7%
+-commutative61.7%
log1p-undefine61.7%
rem-exp-log61.7%
associate-+r+82.4%
metadata-eval82.4%
mul0-lft82.4%
*-commutative82.4%
*-commutative82.4%
associate-*r*82.4%
distribute-rgt-in82.4%
+-lft-identity82.4%
Simplified82.4%
Final simplification92.6%
(FPCore (cosTheta_i u1 u2) :precision binary32 (* (sqrt u1) (sin (* 2.0 (* PI u2)))))
float code(float cosTheta_i, float u1, float u2) {
return sqrtf(u1) * sinf((2.0f * (((float) M_PI) * u2)));
}
function code(cosTheta_i, u1, u2) return Float32(sqrt(u1) * sin(Float32(Float32(2.0) * Float32(Float32(pi) * u2)))) end
function tmp = code(cosTheta_i, u1, u2) tmp = sqrt(u1) * sin((single(2.0) * (single(pi) * u2))); end
\begin{array}{l}
\\
\sqrt{u1} \cdot \sin \left(2 \cdot \left(\pi \cdot u2\right)\right)
\end{array}
Initial program 56.8%
Taylor expanded in u1 around 0 -0.0%
associate-*r*-0.0%
unpow2-0.0%
rem-square-sqrt4.1%
*-commutative4.1%
associate-*l*4.1%
*-commutative4.1%
mul-1-neg4.1%
Simplified4.1%
expm1-log1p-u4.1%
expm1-undefine5.3%
*-commutative5.3%
add-sqr-sqrt-0.0%
sqrt-unprod31.8%
sqr-neg31.8%
add-sqr-sqrt31.8%
associate-*r*31.8%
*-commutative31.8%
*-commutative31.8%
*-commutative31.8%
Applied egg-rr31.8%
sub-neg31.8%
metadata-eval31.8%
+-commutative31.8%
log1p-undefine31.8%
rem-exp-log31.8%
associate-+r+78.1%
metadata-eval78.1%
mul0-lft78.1%
*-commutative78.1%
*-commutative78.1%
associate-*r*78.1%
distribute-rgt-in78.1%
+-lft-identity78.1%
Simplified78.1%
Final simplification78.1%
(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 56.8%
Taylor expanded in u1 around 0 -0.0%
associate-*r*-0.0%
unpow2-0.0%
rem-square-sqrt4.1%
*-commutative4.1%
associate-*l*4.1%
*-commutative4.1%
mul-1-neg4.1%
Simplified4.1%
Taylor expanded in u2 around 0 4.8%
Final simplification4.8%
(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(Float32(2.0) * 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}
\\
\left(2 \cdot \left(\pi \cdot u2\right)\right) \cdot \sqrt{u1}
\end{array}
Initial program 56.8%
Taylor expanded in u1 around 0 -0.0%
associate-*r*-0.0%
unpow2-0.0%
rem-square-sqrt4.1%
*-commutative4.1%
associate-*l*4.1%
*-commutative4.1%
mul-1-neg4.1%
Simplified4.1%
expm1-log1p-u4.1%
expm1-undefine5.3%
*-commutative5.3%
add-sqr-sqrt-0.0%
sqrt-unprod31.8%
sqr-neg31.8%
add-sqr-sqrt31.8%
associate-*r*31.8%
*-commutative31.8%
*-commutative31.8%
*-commutative31.8%
Applied egg-rr31.8%
sub-neg31.8%
metadata-eval31.8%
+-commutative31.8%
log1p-undefine31.8%
rem-exp-log31.8%
associate-+r+78.1%
metadata-eval78.1%
mul0-lft78.1%
*-commutative78.1%
*-commutative78.1%
associate-*r*78.1%
distribute-rgt-in78.1%
+-lft-identity78.1%
Simplified78.1%
Taylor expanded in u2 around 0 67.3%
Final simplification67.3%
herbie shell --seed 2024078
(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))))