
(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 (let* ((t_0 (sin (* 2.0 (* PI u2))))) (cbrt (* (* t_0 (pow t_0 2.0)) (pow (- (log1p (- u1))) 1.5)))))
float code(float cosTheta_i, float u1, float u2) {
float t_0 = sinf((2.0f * (((float) M_PI) * u2)));
return cbrtf(((t_0 * powf(t_0, 2.0f)) * powf(-log1pf(-u1), 1.5f)));
}
function code(cosTheta_i, u1, u2) t_0 = sin(Float32(Float32(2.0) * Float32(Float32(pi) * u2))) return cbrt(Float32(Float32(t_0 * (t_0 ^ Float32(2.0))) * (Float32(-log1p(Float32(-u1))) ^ Float32(1.5)))) end
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \sin \left(2 \cdot \left(\pi \cdot u2\right)\right)\\
\sqrt[3]{\left(t\_0 \cdot {t\_0}^{2}\right) \cdot {\left(-\mathsf{log1p}\left(-u1\right)\right)}^{1.5}}
\end{array}
\end{array}
Initial program 58.6%
sub-neg58.6%
log1p-define98.5%
Simplified98.5%
associate-*l*98.5%
sin-298.3%
Applied egg-rr98.3%
sin-298.5%
*-commutative98.5%
add-cbrt-cube98.5%
add-cbrt-cube98.5%
cbrt-unprod98.3%
pow398.2%
Applied egg-rr98.4%
unpow398.5%
pow298.5%
Applied egg-rr98.5%
Final simplification98.5%
(FPCore (cosTheta_i u1 u2) :precision binary32 (* (sqrt (- (log1p (- u1)))) (sin (* u2 (* 2.0 PI)))))
float code(float cosTheta_i, float u1, float u2) {
return sqrtf(-log1pf(-u1)) * sinf((u2 * (2.0f * ((float) M_PI))));
}
function code(cosTheta_i, u1, u2) return Float32(sqrt(Float32(-log1p(Float32(-u1)))) * sin(Float32(u2 * Float32(Float32(2.0) * Float32(pi))))) end
\begin{array}{l}
\\
\sqrt{-\mathsf{log1p}\left(-u1\right)} \cdot \sin \left(u2 \cdot \left(2 \cdot \pi\right)\right)
\end{array}
Initial program 58.6%
sub-neg58.6%
log1p-define98.5%
Simplified98.5%
Final simplification98.5%
(FPCore (cosTheta_i u1 u2)
:precision binary32
(let* ((t_0 (* u2 (* 2.0 PI))))
(if (<= t_0 0.002099999925121665)
(* (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 * (2.0f * ((float) M_PI));
float tmp;
if (t_0 <= 0.002099999925121665f) {
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(2.0) * Float32(pi))) tmp = Float32(0.0) if (t_0 <= Float32(0.002099999925121665)) 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(2 \cdot \pi\right)\\
\mathbf{if}\;t\_0 \leq 0.002099999925121665:\\
\;\;\;\;\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) < 0.00209999993Initial program 58.8%
sub-neg58.8%
log1p-define98.7%
Simplified98.7%
associate-*l*98.7%
sin-298.6%
Applied egg-rr98.6%
Taylor expanded in u2 around 0 98.3%
if 0.00209999993 < (*.f32 (*.f32 #s(literal 2 binary32) (PI.f32)) u2) Initial program 58.2%
Taylor expanded in u1 around 0 89.7%
Final simplification95.4%
(FPCore (cosTheta_i u1 u2)
:precision binary32
(let* ((t_0 (* u2 (* 2.0 PI))))
(if (<= t_0 0.002099999925121665)
(* (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 * (2.0f * ((float) M_PI));
float tmp;
if (t_0 <= 0.002099999925121665f) {
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(2.0) * Float32(pi))) tmp = Float32(0.0) if (t_0 <= Float32(0.002099999925121665)) 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(2 \cdot \pi\right)\\
\mathbf{if}\;t\_0 \leq 0.002099999925121665:\\
\;\;\;\;\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) < 0.00209999993Initial program 58.8%
sub-neg58.8%
log1p-define98.7%
Simplified98.7%
associate-*l*98.7%
sin-298.6%
Applied egg-rr98.6%
Taylor expanded in u2 around 0 98.3%
if 0.00209999993 < (*.f32 (*.f32 #s(literal 2 binary32) (PI.f32)) u2) Initial program 58.2%
Taylor expanded in u1 around 0 86.2%
Final simplification94.2%
(FPCore (cosTheta_i u1 u2) :precision binary32 (* (sin (* u2 (* 2.0 PI))) (sqrt (* u1 (+ 1.0 (* u1 (- 0.5 (* u1 (- (* u1 -0.25) 0.3333333333333333)))))))))
float code(float cosTheta_i, float u1, float u2) {
return sinf((u2 * (2.0f * ((float) M_PI)))) * sqrtf((u1 * (1.0f + (u1 * (0.5f - (u1 * ((u1 * -0.25f) - 0.3333333333333333f)))))));
}
function code(cosTheta_i, u1, u2) return Float32(sin(Float32(u2 * Float32(Float32(2.0) * Float32(pi)))) * sqrt(Float32(u1 * Float32(Float32(1.0) + Float32(u1 * Float32(Float32(0.5) - Float32(u1 * Float32(Float32(u1 * Float32(-0.25)) - Float32(0.3333333333333333))))))))) end
function tmp = code(cosTheta_i, u1, u2) tmp = sin((u2 * (single(2.0) * single(pi)))) * sqrt((u1 * (single(1.0) + (u1 * (single(0.5) - (u1 * ((u1 * single(-0.25)) - single(0.3333333333333333)))))))); end
\begin{array}{l}
\\
\sin \left(u2 \cdot \left(2 \cdot \pi\right)\right) \cdot \sqrt{u1 \cdot \left(1 + u1 \cdot \left(0.5 - u1 \cdot \left(u1 \cdot -0.25 - 0.3333333333333333\right)\right)\right)}
\end{array}
Initial program 58.6%
Taylor expanded in u1 around 0 93.3%
Final simplification93.3%
(FPCore (cosTheta_i u1 u2) :precision binary32 (if (<= (* u2 (* 2.0 PI)) 0.04500000178813934) (* (sqrt (- (log1p (- u1)))) (* 2.0 (* PI u2))) (* (sqrt u1) (sin (* PI (* 2.0 u2))))))
float code(float cosTheta_i, float u1, float u2) {
float tmp;
if ((u2 * (2.0f * ((float) M_PI))) <= 0.04500000178813934f) {
tmp = sqrtf(-log1pf(-u1)) * (2.0f * (((float) M_PI) * u2));
} else {
tmp = sqrtf(u1) * sinf((((float) M_PI) * (2.0f * u2)));
}
return tmp;
}
function code(cosTheta_i, u1, u2) tmp = Float32(0.0) if (Float32(u2 * Float32(Float32(2.0) * Float32(pi))) <= Float32(0.04500000178813934)) tmp = Float32(sqrt(Float32(-log1p(Float32(-u1)))) * Float32(Float32(2.0) * Float32(Float32(pi) * u2))); else tmp = Float32(sqrt(u1) * sin(Float32(Float32(pi) * Float32(Float32(2.0) * u2)))); end return tmp end
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;u2 \cdot \left(2 \cdot \pi\right) \leq 0.04500000178813934:\\
\;\;\;\;\sqrt{-\mathsf{log1p}\left(-u1\right)} \cdot \left(2 \cdot \left(\pi \cdot u2\right)\right)\\
\mathbf{else}:\\
\;\;\;\;\sqrt{u1} \cdot \sin \left(\pi \cdot \left(2 \cdot u2\right)\right)\\
\end{array}
\end{array}
if (*.f32 (*.f32 #s(literal 2 binary32) (PI.f32)) u2) < 0.0450000018Initial program 59.3%
sub-neg59.3%
log1p-define98.6%
Simplified98.6%
associate-*l*98.6%
sin-298.5%
Applied egg-rr98.5%
Taylor expanded in u2 around 0 94.2%
if 0.0450000018 < (*.f32 (*.f32 #s(literal 2 binary32) (PI.f32)) u2) Initial program 55.8%
sub-neg55.8%
log1p-define98.0%
Simplified98.0%
add-cbrt-cube98.0%
pow1/395.5%
Applied egg-rr72.3%
unpow1/374.2%
Simplified74.2%
Taylor expanded in u1 around 0 76.1%
associate-*r*76.1%
*-commutative76.1%
*-commutative76.1%
Simplified76.1%
Final simplification90.7%
(FPCore (cosTheta_i u1 u2) :precision binary32 (* (sqrt u1) (sin (* PI (* 2.0 u2)))))
float code(float cosTheta_i, float u1, float u2) {
return sqrtf(u1) * sinf((((float) M_PI) * (2.0f * u2)));
}
function code(cosTheta_i, u1, u2) return Float32(sqrt(u1) * sin(Float32(Float32(pi) * Float32(Float32(2.0) * u2)))) end
function tmp = code(cosTheta_i, u1, u2) tmp = sqrt(u1) * sin((single(pi) * (single(2.0) * u2))); end
\begin{array}{l}
\\
\sqrt{u1} \cdot \sin \left(\pi \cdot \left(2 \cdot u2\right)\right)
\end{array}
Initial program 58.6%
sub-neg58.6%
log1p-define98.5%
Simplified98.5%
add-cbrt-cube98.5%
pow1/396.0%
Applied egg-rr72.1%
unpow1/373.7%
Simplified73.7%
Taylor expanded in u1 around 0 75.8%
associate-*r*75.8%
*-commutative75.8%
*-commutative75.8%
Simplified75.8%
Final simplification75.8%
(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(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 58.6%
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%
add-cube-cbrt4.0%
pow34.0%
*-commutative4.0%
add-sqr-sqrt-0.0%
sqrt-unprod75.5%
sqr-neg75.5%
add-sqr-sqrt75.5%
*-commutative75.5%
associate-*r*75.5%
*-commutative75.5%
associate-*l*75.5%
Applied egg-rr75.5%
Taylor expanded in u2 around 0 67.6%
associate-*r*67.7%
*-commutative67.7%
Simplified67.7%
Final simplification67.7%
(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 58.6%
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%
add-cube-cbrt4.0%
pow34.0%
*-commutative4.0%
add-sqr-sqrt-0.0%
sqrt-unprod75.5%
sqr-neg75.5%
add-sqr-sqrt75.5%
*-commutative75.5%
associate-*r*75.5%
*-commutative75.5%
associate-*l*75.5%
Applied egg-rr75.5%
Taylor expanded in u2 around 0 67.6%
associate-*r*67.7%
*-commutative67.7%
associate-*r*67.7%
*-commutative67.7%
Simplified67.7%
(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 58.6%
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 4.3%
Taylor expanded in u1 around -inf -0.0%
mul-1-neg-0.0%
distribute-rgt-neg-in-0.0%
*-commutative-0.0%
unpow2-0.0%
rem-square-sqrt4.3%
neg-mul-14.3%
distribute-rgt-neg-in4.3%
*-commutative4.3%
remove-double-neg4.3%
*-commutative4.3%
associate-*l*4.3%
Simplified4.3%
herbie shell --seed 2024081
(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))))