
(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 (let* ((t_0 (sqrt (* PI 2.0)))) (* (sqrt (- (log1p (- u1)))) (sin (* t_0 (* u2 t_0))))))
float code(float cosTheta_i, float u1, float u2) {
float t_0 = sqrtf((((float) M_PI) * 2.0f));
return sqrtf(-log1pf(-u1)) * sinf((t_0 * (u2 * t_0)));
}
function code(cosTheta_i, u1, u2) t_0 = sqrt(Float32(Float32(pi) * Float32(2.0))) return Float32(sqrt(Float32(-log1p(Float32(-u1)))) * sin(Float32(t_0 * Float32(u2 * t_0)))) end
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \sqrt{\pi \cdot 2}\\
\sqrt{-\mathsf{log1p}\left(-u1\right)} \cdot \sin \left(t\_0 \cdot \left(u2 \cdot t\_0\right)\right)
\end{array}
\end{array}
Initial program 59.6%
sub-neg59.6%
log1p-define98.4%
Simplified98.4%
expm1-log1p-u98.4%
associate-*l*98.4%
Applied egg-rr98.4%
expm1-log1p-u98.4%
associate-*r*98.4%
*-commutative98.4%
add-sqr-sqrt98.4%
associate-*r*98.6%
*-commutative98.6%
*-commutative98.6%
Applied egg-rr98.6%
Final simplification98.6%
(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 59.6%
sub-neg59.6%
log1p-define98.4%
Simplified98.4%
Final simplification98.4%
(FPCore (cosTheta_i u1 u2) :precision binary32 (* (sin (* u2 (* PI 2.0))) (sqrt (* u1 (+ 1.0 (* u1 (+ 0.5 (* u1 (- 0.3333333333333333 (* u1 -0.25))))))))))
float code(float cosTheta_i, float u1, float u2) {
return sinf((u2 * (((float) M_PI) * 2.0f))) * sqrtf((u1 * (1.0f + (u1 * (0.5f + (u1 * (0.3333333333333333f - (u1 * -0.25f))))))));
}
function code(cosTheta_i, u1, u2) return Float32(sin(Float32(u2 * Float32(Float32(pi) * Float32(2.0)))) * 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
function tmp = code(cosTheta_i, u1, u2) tmp = sin((u2 * (single(pi) * single(2.0)))) * sqrt((u1 * (single(1.0) + (u1 * (single(0.5) + (u1 * (single(0.3333333333333333) - (u1 * single(-0.25))))))))); end
\begin{array}{l}
\\
\sin \left(u2 \cdot \left(\pi \cdot 2\right)\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 59.6%
Taylor expanded in u1 around 0 92.8%
Final simplification92.8%
(FPCore (cosTheta_i u1 u2) :precision binary32 (* (sin (* u2 (* PI 2.0))) (sqrt (* u1 (+ 1.0 (* u1 (- 0.5 (* u1 -0.3333333333333333))))))))
float code(float cosTheta_i, float u1, float u2) {
return sinf((u2 * (((float) M_PI) * 2.0f))) * sqrtf((u1 * (1.0f + (u1 * (0.5f - (u1 * -0.3333333333333333f))))));
}
function code(cosTheta_i, u1, u2) return Float32(sin(Float32(u2 * Float32(Float32(pi) * Float32(2.0)))) * sqrt(Float32(u1 * Float32(Float32(1.0) + Float32(u1 * Float32(Float32(0.5) - Float32(u1 * Float32(-0.3333333333333333)))))))) end
function tmp = code(cosTheta_i, u1, u2) tmp = sin((u2 * (single(pi) * single(2.0)))) * sqrt((u1 * (single(1.0) + (u1 * (single(0.5) - (u1 * single(-0.3333333333333333))))))); end
\begin{array}{l}
\\
\sin \left(u2 \cdot \left(\pi \cdot 2\right)\right) \cdot \sqrt{u1 \cdot \left(1 + u1 \cdot \left(0.5 - u1 \cdot -0.3333333333333333\right)\right)}
\end{array}
Initial program 59.6%
Taylor expanded in u1 around 0 90.9%
Final simplification90.9%
(FPCore (cosTheta_i u1 u2) :precision binary32 (* (sin (* u2 (* PI 2.0))) (sqrt (* u1 (- 1.0 (* u1 -0.5))))))
float code(float cosTheta_i, float u1, float u2) {
return sinf((u2 * (((float) M_PI) * 2.0f))) * sqrtf((u1 * (1.0f - (u1 * -0.5f))));
}
function code(cosTheta_i, u1, u2) return Float32(sin(Float32(u2 * Float32(Float32(pi) * Float32(2.0)))) * sqrt(Float32(u1 * Float32(Float32(1.0) - Float32(u1 * Float32(-0.5)))))) end
function tmp = code(cosTheta_i, u1, u2) tmp = sin((u2 * (single(pi) * single(2.0)))) * sqrt((u1 * (single(1.0) - (u1 * single(-0.5))))); end
\begin{array}{l}
\\
\sin \left(u2 \cdot \left(\pi \cdot 2\right)\right) \cdot \sqrt{u1 \cdot \left(1 - u1 \cdot -0.5\right)}
\end{array}
Initial program 59.6%
Taylor expanded in u1 around 0 87.3%
Final simplification87.3%
(FPCore (cosTheta_i u1 u2) :precision binary32 (* (sin (* u2 (* PI 2.0))) (sqrt u1)))
float code(float cosTheta_i, float u1, float u2) {
return sinf((u2 * (((float) M_PI) * 2.0f))) * sqrtf(u1);
}
function code(cosTheta_i, u1, u2) return Float32(sin(Float32(u2 * Float32(Float32(pi) * Float32(2.0)))) * sqrt(u1)) end
function tmp = code(cosTheta_i, u1, u2) tmp = sin((u2 * (single(pi) * single(2.0)))) * sqrt(u1); end
\begin{array}{l}
\\
\sin \left(u2 \cdot \left(\pi \cdot 2\right)\right) \cdot \sqrt{u1}
\end{array}
Initial program 59.6%
sub-neg59.6%
log1p-define98.4%
Simplified98.4%
add-cbrt-cube98.4%
pow1/395.9%
Applied egg-rr71.9%
unpow1/373.4%
Simplified73.4%
Taylor expanded in u1 around 0 75.6%
*-commutative75.6%
associate-*r*75.6%
Simplified75.6%
Final simplification75.6%
(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 59.6%
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-sqr-sqrt0.1%
pow20.1%
Applied egg-rr73.2%
Taylor expanded in u2 around 0 65.4%
*-commutative65.4%
associate-*r*65.5%
*-commutative65.5%
*-commutative65.5%
Simplified65.5%
(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 59.6%
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 4.6%
associate-*r*4.6%
Simplified4.6%
Final simplification4.6%
(FPCore (cosTheta_i u1 u2) :precision binary32 (* (* u2 (* PI (sqrt u1))) -2.0))
float code(float cosTheta_i, float u1, float u2) {
return (u2 * (((float) M_PI) * sqrtf(u1))) * -2.0f;
}
function code(cosTheta_i, u1, u2) return Float32(Float32(u2 * Float32(Float32(pi) * sqrt(u1))) * Float32(-2.0)) end
function tmp = code(cosTheta_i, u1, u2) tmp = (u2 * (single(pi) * sqrt(u1))) * single(-2.0); end
\begin{array}{l}
\\
\left(u2 \cdot \left(\pi \cdot \sqrt{u1}\right)\right) \cdot -2
\end{array}
Initial program 59.6%
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 4.6%
associate-*r*4.6%
Simplified4.6%
pow14.6%
*-commutative4.6%
associate-*r*4.6%
Applied egg-rr4.6%
unpow14.6%
*-commutative4.6%
*-commutative4.6%
Simplified4.6%
Final simplification4.6%
herbie shell --seed 2024089
(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))))