
(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 8 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 (log1p (expm1 (* (* u2 2.0) PI))))))
float code(float cosTheta_i, float u1, float u2) {
return sqrtf(-log1pf(-u1)) * sinf(log1pf(expm1f(((u2 * 2.0f) * ((float) M_PI)))));
}
function code(cosTheta_i, u1, u2) return Float32(sqrt(Float32(-log1p(Float32(-u1)))) * sin(log1p(expm1(Float32(Float32(u2 * Float32(2.0)) * Float32(pi)))))) end
\begin{array}{l}
\\
\sqrt{-\mathsf{log1p}\left(-u1\right)} \cdot \sin \left(\mathsf{log1p}\left(\mathsf{expm1}\left(\left(u2 \cdot 2\right) \cdot \pi\right)\right)\right)
\end{array}
Initial program 57.4%
sub-neg57.4%
log1p-define98.3%
Simplified98.3%
log1p-expm1-u98.3%
*-commutative98.3%
associate-*r*98.3%
Applied egg-rr98.3%
(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 57.4%
sub-neg57.4%
log1p-define98.3%
Simplified98.3%
Final simplification98.3%
(FPCore (cosTheta_i u1 u2) :precision binary32 (* (sin (* u2 (* 2.0 PI))) (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 * (2.0f * ((float) M_PI)))) * 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(2.0) * Float32(pi)))) * 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(2.0) * single(pi)))) * 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(2 \cdot \pi\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 57.4%
Taylor expanded in u1 around 0 92.0%
*-commutative92.0%
Simplified92.0%
Final simplification92.0%
(FPCore (cosTheta_i u1 u2) :precision binary32 (* (sin (* u2 (* 2.0 PI))) (sqrt (* u1 (+ 1.0 (* u1 (+ 0.5 (* u1 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 * 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(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 * 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 0.3333333333333333\right)\right)}
\end{array}
Initial program 57.4%
Taylor expanded in u1 around 0 90.2%
*-commutative90.2%
Simplified90.2%
Final simplification90.2%
(FPCore (cosTheta_i u1 u2) :precision binary32 (* (sin (* u2 (* 2.0 PI))) (sqrt (* u1 (+ 1.0 (* u1 0.5))))))
float code(float cosTheta_i, float u1, float u2) {
return sinf((u2 * (2.0f * ((float) M_PI)))) * sqrtf((u1 * (1.0f + (u1 * 0.5f))));
}
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(0.5)))))) 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))))); end
\begin{array}{l}
\\
\sin \left(u2 \cdot \left(2 \cdot \pi\right)\right) \cdot \sqrt{u1 \cdot \left(1 + u1 \cdot 0.5\right)}
\end{array}
Initial program 57.4%
Taylor expanded in u1 around 0 87.0%
*-commutative87.0%
Simplified87.0%
Final simplification87.0%
(FPCore (cosTheta_i u1 u2) :precision binary32 (* (sin (* u2 (* 2.0 PI))) (sqrt u1)))
float code(float cosTheta_i, float u1, float u2) {
return sinf((u2 * (2.0f * ((float) M_PI)))) * sqrtf(u1);
}
function code(cosTheta_i, u1, u2) return Float32(sin(Float32(u2 * Float32(Float32(2.0) * Float32(pi)))) * sqrt(u1)) end
function tmp = code(cosTheta_i, u1, u2) tmp = sin((u2 * (single(2.0) * single(pi)))) * sqrt(u1); end
\begin{array}{l}
\\
\sin \left(u2 \cdot \left(2 \cdot \pi\right)\right) \cdot \sqrt{u1}
\end{array}
Initial program 57.4%
Taylor expanded in u1 around 0 76.2%
Final simplification76.2%
(FPCore (cosTheta_i u1 u2) :precision binary32 (* (* 2.0 (sqrt u1)) (* u2 PI)))
float code(float cosTheta_i, float u1, float u2) {
return (2.0f * sqrtf(u1)) * (u2 * ((float) M_PI));
}
function code(cosTheta_i, u1, u2) return Float32(Float32(Float32(2.0) * sqrt(u1)) * Float32(u2 * Float32(pi))) end
function tmp = code(cosTheta_i, u1, u2) tmp = (single(2.0) * sqrt(u1)) * (u2 * single(pi)); end
\begin{array}{l}
\\
\left(2 \cdot \sqrt{u1}\right) \cdot \left(u2 \cdot \pi\right)
\end{array}
Initial program 57.4%
Taylor expanded in u1 around 0 76.2%
Taylor expanded in u2 around 0 63.7%
associate-*r*63.7%
Simplified63.7%
(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 57.4%
Taylor expanded in u1 around 0 76.2%
Taylor expanded in u2 around 0 63.7%
associate-*r*63.7%
Simplified63.7%
pow163.7%
add-sqr-sqrt63.6%
sqrt-unprod63.7%
*-commutative63.7%
*-commutative63.7%
swap-sqr63.7%
add-sqr-sqrt63.7%
metadata-eval63.7%
*-commutative63.7%
Applied egg-rr63.7%
unpow163.7%
associate-*r*63.7%
*-commutative63.7%
*-commutative63.7%
Simplified63.7%
herbie shell --seed 2024113
(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))))