
(FPCore (cosTheta alpha)
:precision binary32
(let* ((t_0 (- (* alpha alpha) 1.0)))
(/
t_0
(* (* PI (log (* alpha alpha))) (+ 1.0 (* (* t_0 cosTheta) cosTheta))))))
float code(float cosTheta, float alpha) {
float t_0 = (alpha * alpha) - 1.0f;
return t_0 / ((((float) M_PI) * logf((alpha * alpha))) * (1.0f + ((t_0 * cosTheta) * cosTheta)));
}
function code(cosTheta, alpha) t_0 = Float32(Float32(alpha * alpha) - Float32(1.0)) return Float32(t_0 / Float32(Float32(Float32(pi) * log(Float32(alpha * alpha))) * Float32(Float32(1.0) + Float32(Float32(t_0 * cosTheta) * cosTheta)))) end
function tmp = code(cosTheta, alpha) t_0 = (alpha * alpha) - single(1.0); tmp = t_0 / ((single(pi) * log((alpha * alpha))) * (single(1.0) + ((t_0 * cosTheta) * cosTheta))); end
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \alpha \cdot \alpha - 1\\
\frac{t_0}{\left(\pi \cdot \log \left(\alpha \cdot \alpha\right)\right) \cdot \left(1 + \left(t_0 \cdot cosTheta\right) \cdot cosTheta\right)}
\end{array}
\end{array}
Sampling outcomes in binary32 precision:
Herbie found 11 alternatives:
| Alternative | Accuracy | Speedup |
|---|
(FPCore (cosTheta alpha)
:precision binary32
(let* ((t_0 (- (* alpha alpha) 1.0)))
(/
t_0
(* (* PI (log (* alpha alpha))) (+ 1.0 (* (* t_0 cosTheta) cosTheta))))))
float code(float cosTheta, float alpha) {
float t_0 = (alpha * alpha) - 1.0f;
return t_0 / ((((float) M_PI) * logf((alpha * alpha))) * (1.0f + ((t_0 * cosTheta) * cosTheta)));
}
function code(cosTheta, alpha) t_0 = Float32(Float32(alpha * alpha) - Float32(1.0)) return Float32(t_0 / Float32(Float32(Float32(pi) * log(Float32(alpha * alpha))) * Float32(Float32(1.0) + Float32(Float32(t_0 * cosTheta) * cosTheta)))) end
function tmp = code(cosTheta, alpha) t_0 = (alpha * alpha) - single(1.0); tmp = t_0 / ((single(pi) * log((alpha * alpha))) * (single(1.0) + ((t_0 * cosTheta) * cosTheta))); end
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \alpha \cdot \alpha - 1\\
\frac{t_0}{\left(\pi \cdot \log \left(\alpha \cdot \alpha\right)\right) \cdot \left(1 + \left(t_0 \cdot cosTheta\right) \cdot cosTheta\right)}
\end{array}
\end{array}
(FPCore (cosTheta alpha)
:precision binary32
(let* ((t_0 (+ (* alpha alpha) -1.0)))
(/
t_0
(* (log (pow alpha (* PI 2.0))) (+ 1.0 (* cosTheta (* t_0 cosTheta)))))))
float code(float cosTheta, float alpha) {
float t_0 = (alpha * alpha) + -1.0f;
return t_0 / (logf(powf(alpha, (((float) M_PI) * 2.0f))) * (1.0f + (cosTheta * (t_0 * cosTheta))));
}
function code(cosTheta, alpha) t_0 = Float32(Float32(alpha * alpha) + Float32(-1.0)) return Float32(t_0 / Float32(log((alpha ^ Float32(Float32(pi) * Float32(2.0)))) * Float32(Float32(1.0) + Float32(cosTheta * Float32(t_0 * cosTheta))))) end
function tmp = code(cosTheta, alpha) t_0 = (alpha * alpha) + single(-1.0); tmp = t_0 / (log((alpha ^ (single(pi) * single(2.0)))) * (single(1.0) + (cosTheta * (t_0 * cosTheta)))); end
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \alpha \cdot \alpha + -1\\
\frac{t_0}{\log \left({\alpha}^{\left(\pi \cdot 2\right)}\right) \cdot \left(1 + cosTheta \cdot \left(t_0 \cdot cosTheta\right)\right)}
\end{array}
\end{array}
Initial program 98.6%
pow298.6%
log-pow98.5%
associate-*l*98.5%
add-log-exp98.5%
*-commutative98.5%
exp-to-pow98.7%
Applied egg-rr98.7%
Final simplification98.7%
(FPCore (cosTheta alpha)
:precision binary32
(let* ((t_0 (+ (* alpha alpha) -1.0)))
(/
t_0
(* (+ 1.0 (* cosTheta (* t_0 cosTheta))) (* 2.0 (* PI (log alpha)))))))
float code(float cosTheta, float alpha) {
float t_0 = (alpha * alpha) + -1.0f;
return t_0 / ((1.0f + (cosTheta * (t_0 * cosTheta))) * (2.0f * (((float) M_PI) * logf(alpha))));
}
function code(cosTheta, alpha) t_0 = Float32(Float32(alpha * alpha) + Float32(-1.0)) return Float32(t_0 / Float32(Float32(Float32(1.0) + Float32(cosTheta * Float32(t_0 * cosTheta))) * Float32(Float32(2.0) * Float32(Float32(pi) * log(alpha))))) end
function tmp = code(cosTheta, alpha) t_0 = (alpha * alpha) + single(-1.0); tmp = t_0 / ((single(1.0) + (cosTheta * (t_0 * cosTheta))) * (single(2.0) * (single(pi) * log(alpha)))); end
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \alpha \cdot \alpha + -1\\
\frac{t_0}{\left(1 + cosTheta \cdot \left(t_0 \cdot cosTheta\right)\right) \cdot \left(2 \cdot \left(\pi \cdot \log \alpha\right)\right)}
\end{array}
\end{array}
Initial program 98.6%
Taylor expanded in alpha around 0 98.5%
Final simplification98.5%
(FPCore (cosTheta alpha)
:precision binary32
(let* ((t_0 (+ (* alpha alpha) -1.0)))
(/
t_0
(* (+ 1.0 (* cosTheta (* t_0 cosTheta))) (* PI (log (* alpha alpha)))))))
float code(float cosTheta, float alpha) {
float t_0 = (alpha * alpha) + -1.0f;
return t_0 / ((1.0f + (cosTheta * (t_0 * cosTheta))) * (((float) M_PI) * logf((alpha * alpha))));
}
function code(cosTheta, alpha) t_0 = Float32(Float32(alpha * alpha) + Float32(-1.0)) return Float32(t_0 / Float32(Float32(Float32(1.0) + Float32(cosTheta * Float32(t_0 * cosTheta))) * Float32(Float32(pi) * log(Float32(alpha * alpha))))) end
function tmp = code(cosTheta, alpha) t_0 = (alpha * alpha) + single(-1.0); tmp = t_0 / ((single(1.0) + (cosTheta * (t_0 * cosTheta))) * (single(pi) * log((alpha * alpha)))); end
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \alpha \cdot \alpha + -1\\
\frac{t_0}{\left(1 + cosTheta \cdot \left(t_0 \cdot cosTheta\right)\right) \cdot \left(\pi \cdot \log \left(\alpha \cdot \alpha\right)\right)}
\end{array}
\end{array}
Initial program 98.6%
Final simplification98.6%
(FPCore (cosTheta alpha) :precision binary32 (/ (+ (* alpha alpha) -1.0) (* (* PI (log (* alpha alpha))) (- 1.0 (* cosTheta cosTheta)))))
float code(float cosTheta, float alpha) {
return ((alpha * alpha) + -1.0f) / ((((float) M_PI) * logf((alpha * alpha))) * (1.0f - (cosTheta * cosTheta)));
}
function code(cosTheta, alpha) return Float32(Float32(Float32(alpha * alpha) + Float32(-1.0)) / Float32(Float32(Float32(pi) * log(Float32(alpha * alpha))) * Float32(Float32(1.0) - Float32(cosTheta * cosTheta)))) end
function tmp = code(cosTheta, alpha) tmp = ((alpha * alpha) + single(-1.0)) / ((single(pi) * log((alpha * alpha))) * (single(1.0) - (cosTheta * cosTheta))); end
\begin{array}{l}
\\
\frac{\alpha \cdot \alpha + -1}{\left(\pi \cdot \log \left(\alpha \cdot \alpha\right)\right) \cdot \left(1 - cosTheta \cdot cosTheta\right)}
\end{array}
Initial program 98.6%
Taylor expanded in alpha around 0 97.5%
mul-1-neg97.5%
Simplified97.5%
Final simplification97.5%
(FPCore (cosTheta alpha) :precision binary32 (* 0.5 (/ (* (+ alpha 1.0) (+ alpha -1.0)) (* PI (log alpha)))))
float code(float cosTheta, float alpha) {
return 0.5f * (((alpha + 1.0f) * (alpha + -1.0f)) / (((float) M_PI) * logf(alpha)));
}
function code(cosTheta, alpha) return Float32(Float32(0.5) * Float32(Float32(Float32(alpha + Float32(1.0)) * Float32(alpha + Float32(-1.0))) / Float32(Float32(pi) * log(alpha)))) end
function tmp = code(cosTheta, alpha) tmp = single(0.5) * (((alpha + single(1.0)) * (alpha + single(-1.0))) / (single(pi) * log(alpha))); end
\begin{array}{l}
\\
0.5 \cdot \frac{\left(\alpha + 1\right) \cdot \left(\alpha + -1\right)}{\pi \cdot \log \alpha}
\end{array}
Initial program 98.6%
associate-/r*98.6%
fma-neg98.4%
metadata-eval98.4%
log-prod98.5%
distribute-rgt-in98.5%
distribute-lft-out98.5%
*-rgt-identity98.5%
*-rgt-identity98.5%
distribute-lft-out98.5%
metadata-eval98.5%
+-commutative98.5%
associate-*l*98.5%
fma-def98.5%
fma-neg98.5%
metadata-eval98.5%
Simplified98.5%
metadata-eval98.5%
fma-neg98.5%
difference-of-sqr-198.3%
add-exp-log98.2%
expm1-udef98.3%
associate-*r*98.3%
times-frac98.3%
*-commutative98.3%
expm1-udef98.3%
add-exp-log98.3%
sub-neg98.3%
metadata-eval98.3%
Applied egg-rr98.3%
Taylor expanded in cosTheta around 0 95.1%
Final simplification95.1%
(FPCore (cosTheta alpha) :precision binary32 (* (/ (+ alpha 1.0) (log alpha)) (/ 0.5 (/ PI (+ alpha -1.0)))))
float code(float cosTheta, float alpha) {
return ((alpha + 1.0f) / logf(alpha)) * (0.5f / (((float) M_PI) / (alpha + -1.0f)));
}
function code(cosTheta, alpha) return Float32(Float32(Float32(alpha + Float32(1.0)) / log(alpha)) * Float32(Float32(0.5) / Float32(Float32(pi) / Float32(alpha + Float32(-1.0))))) end
function tmp = code(cosTheta, alpha) tmp = ((alpha + single(1.0)) / log(alpha)) * (single(0.5) / (single(pi) / (alpha + single(-1.0)))); end
\begin{array}{l}
\\
\frac{\alpha + 1}{\log \alpha} \cdot \frac{0.5}{\frac{\pi}{\alpha + -1}}
\end{array}
Initial program 98.6%
Taylor expanded in alpha around 0 97.5%
mul-1-neg97.5%
Simplified97.5%
Taylor expanded in cosTheta around 0 95.5%
unpow295.5%
fma-neg95.3%
metadata-eval95.3%
log-pow95.5%
associate-*l*95.5%
*-commutative95.5%
associate-*r*95.5%
log-pow95.4%
Simplified95.4%
metadata-eval95.4%
fma-neg95.4%
log-pow95.5%
pow-unpow95.5%
difference-of-sqr-195.3%
*-un-lft-identity95.3%
fma-neg95.3%
metadata-eval95.3%
fma-def95.3%
*-un-lft-identity95.3%
log-pow95.1%
frac-times95.1%
associate-*l/95.1%
*-commutative95.1%
times-frac95.1%
Applied egg-rr95.1%
associate-*r/95.1%
div-inv95.1%
metadata-eval95.1%
Applied egg-rr95.1%
associate-/l*94.9%
*-commutative94.9%
associate-/r/95.0%
times-frac95.2%
Simplified95.2%
Final simplification95.2%
(FPCore (cosTheta alpha) :precision binary32 (* (/ (+ alpha -1.0) (* PI 2.0)) (/ (+ alpha 1.0) (log alpha))))
float code(float cosTheta, float alpha) {
return ((alpha + -1.0f) / (((float) M_PI) * 2.0f)) * ((alpha + 1.0f) / logf(alpha));
}
function code(cosTheta, alpha) return Float32(Float32(Float32(alpha + Float32(-1.0)) / Float32(Float32(pi) * Float32(2.0))) * Float32(Float32(alpha + Float32(1.0)) / log(alpha))) end
function tmp = code(cosTheta, alpha) tmp = ((alpha + single(-1.0)) / (single(pi) * single(2.0))) * ((alpha + single(1.0)) / log(alpha)); end
\begin{array}{l}
\\
\frac{\alpha + -1}{\pi \cdot 2} \cdot \frac{\alpha + 1}{\log \alpha}
\end{array}
Initial program 98.6%
Taylor expanded in alpha around 0 97.5%
mul-1-neg97.5%
Simplified97.5%
Taylor expanded in cosTheta around 0 95.5%
unpow295.5%
fma-neg95.3%
metadata-eval95.3%
log-pow95.5%
associate-*l*95.5%
*-commutative95.5%
associate-*r*95.5%
log-pow95.4%
Simplified95.4%
metadata-eval95.4%
fma-neg95.4%
difference-of-sqr-195.2%
*-un-lft-identity95.2%
fma-neg95.2%
metadata-eval95.2%
fma-def95.2%
*-un-lft-identity95.2%
*-commutative95.2%
log-pow95.2%
pow-unpow95.3%
log-pow95.1%
times-frac95.2%
Applied egg-rr95.2%
Final simplification95.2%
(FPCore (cosTheta alpha) :precision binary32 (* (/ (+ alpha 1.0) 2.0) (/ (+ alpha -1.0) (* PI (log alpha)))))
float code(float cosTheta, float alpha) {
return ((alpha + 1.0f) / 2.0f) * ((alpha + -1.0f) / (((float) M_PI) * logf(alpha)));
}
function code(cosTheta, alpha) return Float32(Float32(Float32(alpha + Float32(1.0)) / Float32(2.0)) * Float32(Float32(alpha + Float32(-1.0)) / Float32(Float32(pi) * log(alpha)))) end
function tmp = code(cosTheta, alpha) tmp = ((alpha + single(1.0)) / single(2.0)) * ((alpha + single(-1.0)) / (single(pi) * log(alpha))); end
\begin{array}{l}
\\
\frac{\alpha + 1}{2} \cdot \frac{\alpha + -1}{\pi \cdot \log \alpha}
\end{array}
Initial program 98.6%
Taylor expanded in alpha around 0 97.5%
mul-1-neg97.5%
Simplified97.5%
Taylor expanded in cosTheta around 0 95.5%
unpow295.5%
fma-neg95.3%
metadata-eval95.3%
log-pow95.5%
associate-*l*95.5%
*-commutative95.5%
associate-*r*95.5%
log-pow95.4%
Simplified95.4%
metadata-eval95.4%
fma-neg95.4%
difference-of-sqr-195.2%
*-un-lft-identity95.2%
fma-neg95.2%
metadata-eval95.2%
fma-def95.2%
*-un-lft-identity95.2%
times-frac95.1%
log-pow95.2%
Applied egg-rr95.2%
Final simplification95.2%
(FPCore (cosTheta alpha) :precision binary32 (* 0.5 (* (/ -1.0 PI) (/ 1.0 (log alpha)))))
float code(float cosTheta, float alpha) {
return 0.5f * ((-1.0f / ((float) M_PI)) * (1.0f / logf(alpha)));
}
function code(cosTheta, alpha) return Float32(Float32(0.5) * Float32(Float32(Float32(-1.0) / Float32(pi)) * Float32(Float32(1.0) / log(alpha)))) end
function tmp = code(cosTheta, alpha) tmp = single(0.5) * ((single(-1.0) / single(pi)) * (single(1.0) / log(alpha))); end
\begin{array}{l}
\\
0.5 \cdot \left(\frac{-1}{\pi} \cdot \frac{1}{\log \alpha}\right)
\end{array}
Initial program 98.6%
Taylor expanded in cosTheta around 0 95.5%
unpow295.5%
fma-neg95.3%
metadata-eval95.3%
*-lft-identity95.3%
log-pow95.5%
*-commutative95.5%
times-frac95.1%
associate-/r*95.1%
times-frac95.4%
*-commutative95.4%
times-frac95.4%
metadata-eval95.4%
Simplified95.4%
Taylor expanded in alpha around 0 63.8%
associate-/r*63.8%
Simplified63.8%
div-inv63.8%
Applied egg-rr63.8%
Final simplification63.8%
(FPCore (cosTheta alpha) :precision binary32 (* 0.5 (/ (/ -1.0 PI) (log alpha))))
float code(float cosTheta, float alpha) {
return 0.5f * ((-1.0f / ((float) M_PI)) / logf(alpha));
}
function code(cosTheta, alpha) return Float32(Float32(0.5) * Float32(Float32(Float32(-1.0) / Float32(pi)) / log(alpha))) end
function tmp = code(cosTheta, alpha) tmp = single(0.5) * ((single(-1.0) / single(pi)) / log(alpha)); end
\begin{array}{l}
\\
0.5 \cdot \frac{\frac{-1}{\pi}}{\log \alpha}
\end{array}
Initial program 98.6%
Taylor expanded in cosTheta around 0 95.5%
unpow295.5%
fma-neg95.3%
metadata-eval95.3%
*-lft-identity95.3%
log-pow95.5%
*-commutative95.5%
times-frac95.1%
associate-/r*95.1%
times-frac95.4%
*-commutative95.4%
times-frac95.4%
metadata-eval95.4%
Simplified95.4%
Taylor expanded in alpha around 0 63.8%
associate-/r*63.8%
Simplified63.8%
Final simplification63.8%
(FPCore (cosTheta alpha) :precision binary32 (/ -0.5 (* PI (log alpha))))
float code(float cosTheta, float alpha) {
return -0.5f / (((float) M_PI) * logf(alpha));
}
function code(cosTheta, alpha) return Float32(Float32(-0.5) / Float32(Float32(pi) * log(alpha))) end
function tmp = code(cosTheta, alpha) tmp = single(-0.5) / (single(pi) * log(alpha)); end
\begin{array}{l}
\\
\frac{-0.5}{\pi \cdot \log \alpha}
\end{array}
Initial program 98.6%
Taylor expanded in alpha around 0 64.8%
mul-1-neg64.8%
Simplified64.8%
Taylor expanded in cosTheta around 0 63.8%
Final simplification63.8%
herbie shell --seed 2023308
(FPCore (cosTheta alpha)
:name "GTR1 distribution"
:precision binary32
:pre (and (and (<= 0.0 cosTheta) (<= cosTheta 1.0)) (and (<= 0.0001 alpha) (<= alpha 1.0)))
(/ (- (* alpha alpha) 1.0) (* (* PI (log (* alpha alpha))) (+ 1.0 (* (* (- (* alpha alpha) 1.0) cosTheta) cosTheta)))))