
(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 12 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 (/ (/ 1.0 (/ (* 2.0 PI) (/ (fma alpha alpha -1.0) (log alpha)))) (+ 1.0 (* cosTheta (* (fma alpha alpha -1.0) cosTheta)))))
float code(float cosTheta, float alpha) {
return (1.0f / ((2.0f * ((float) M_PI)) / (fmaf(alpha, alpha, -1.0f) / logf(alpha)))) / (1.0f + (cosTheta * (fmaf(alpha, alpha, -1.0f) * cosTheta)));
}
function code(cosTheta, alpha) return Float32(Float32(Float32(1.0) / Float32(Float32(Float32(2.0) * Float32(pi)) / Float32(fma(alpha, alpha, Float32(-1.0)) / log(alpha)))) / Float32(Float32(1.0) + Float32(cosTheta * Float32(fma(alpha, alpha, Float32(-1.0)) * cosTheta)))) end
\begin{array}{l}
\\
\frac{\frac{1}{\frac{2 \cdot \pi}{\frac{\mathsf{fma}\left(\alpha, \alpha, -1\right)}{\log \alpha}}}}{1 + cosTheta \cdot \left(\mathsf{fma}\left(\alpha, \alpha, -1\right) \cdot cosTheta\right)}
\end{array}
Initial program 98.4%
associate-/r*98.4%
cancel-sign-sub98.4%
distribute-rgt-neg-out98.4%
unsub-neg98.4%
distribute-rgt-neg-out98.4%
fma-neg98.3%
metadata-eval98.3%
*-commutative98.3%
distribute-rgt-neg-out98.3%
distribute-rgt-neg-out98.3%
distribute-lft-neg-in98.3%
Simplified98.3%
clear-num98.1%
inv-pow98.1%
pow298.1%
log-pow98.2%
associate-*r*98.2%
Applied egg-rr98.2%
unpow-198.2%
associate-/l*98.5%
*-commutative98.5%
Simplified98.5%
Final simplification98.5%
(FPCore (cosTheta alpha)
:precision binary32
(let* ((t_0 (+ -1.0 (* alpha alpha))))
(/
t_0
(* (log (pow (pow alpha 2.0) PI)) (+ 1.0 (* cosTheta (* cosTheta t_0)))))))
float code(float cosTheta, float alpha) {
float t_0 = -1.0f + (alpha * alpha);
return t_0 / (logf(powf(powf(alpha, 2.0f), ((float) M_PI))) * (1.0f + (cosTheta * (cosTheta * t_0))));
}
function code(cosTheta, alpha) t_0 = Float32(Float32(-1.0) + Float32(alpha * alpha)) return Float32(t_0 / Float32(log(((alpha ^ Float32(2.0)) ^ Float32(pi))) * Float32(Float32(1.0) + Float32(cosTheta * Float32(cosTheta * t_0))))) end
function tmp = code(cosTheta, alpha) t_0 = single(-1.0) + (alpha * alpha); tmp = t_0 / (log(((alpha ^ single(2.0)) ^ single(pi))) * (single(1.0) + (cosTheta * (cosTheta * t_0)))); end
\begin{array}{l}
\\
\begin{array}{l}
t_0 := -1 + \alpha \cdot \alpha\\
\frac{t_0}{\log \left({\left({\alpha}^{2}\right)}^{\pi}\right) \cdot \left(1 + cosTheta \cdot \left(cosTheta \cdot t_0\right)\right)}
\end{array}
\end{array}
Initial program 98.4%
add-log-exp98.4%
*-commutative98.4%
exp-to-pow98.5%
pow298.5%
Applied egg-rr98.5%
Final simplification98.5%
(FPCore (cosTheta alpha) :precision binary32 (/ (+ -1.0 (* alpha alpha)) (* (* PI (log (* alpha alpha))) (+ 1.0 (* cosTheta (- (* cosTheta (pow alpha 2.0)) cosTheta))))))
float code(float cosTheta, float alpha) {
return (-1.0f + (alpha * alpha)) / ((((float) M_PI) * logf((alpha * alpha))) * (1.0f + (cosTheta * ((cosTheta * powf(alpha, 2.0f)) - cosTheta))));
}
function code(cosTheta, alpha) return Float32(Float32(Float32(-1.0) + Float32(alpha * alpha)) / Float32(Float32(Float32(pi) * log(Float32(alpha * alpha))) * Float32(Float32(1.0) + Float32(cosTheta * Float32(Float32(cosTheta * (alpha ^ Float32(2.0))) - cosTheta))))) end
function tmp = code(cosTheta, alpha) tmp = (single(-1.0) + (alpha * alpha)) / ((single(pi) * log((alpha * alpha))) * (single(1.0) + (cosTheta * ((cosTheta * (alpha ^ single(2.0))) - cosTheta)))); end
\begin{array}{l}
\\
\frac{-1 + \alpha \cdot \alpha}{\left(\pi \cdot \log \left(\alpha \cdot \alpha\right)\right) \cdot \left(1 + cosTheta \cdot \left(cosTheta \cdot {\alpha}^{2} - cosTheta\right)\right)}
\end{array}
Initial program 98.4%
fma-neg98.4%
metadata-eval98.4%
*-commutative98.4%
fma-udef98.4%
distribute-rgt-in98.4%
pow298.4%
Applied egg-rr98.4%
Final simplification98.4%
(FPCore (cosTheta alpha)
:precision binary32
(let* ((t_0 (+ -1.0 (* alpha alpha))))
(/
t_0
(* (+ 1.0 (* cosTheta (* cosTheta t_0))) (* PI (log (* alpha alpha)))))))
float code(float cosTheta, float alpha) {
float t_0 = -1.0f + (alpha * alpha);
return t_0 / ((1.0f + (cosTheta * (cosTheta * t_0))) * (((float) M_PI) * logf((alpha * alpha))));
}
function code(cosTheta, alpha) t_0 = Float32(Float32(-1.0) + Float32(alpha * alpha)) return Float32(t_0 / Float32(Float32(Float32(1.0) + Float32(cosTheta * Float32(cosTheta * t_0))) * Float32(Float32(pi) * log(Float32(alpha * alpha))))) end
function tmp = code(cosTheta, alpha) t_0 = single(-1.0) + (alpha * alpha); tmp = t_0 / ((single(1.0) + (cosTheta * (cosTheta * t_0))) * (single(pi) * log((alpha * alpha)))); end
\begin{array}{l}
\\
\begin{array}{l}
t_0 := -1 + \alpha \cdot \alpha\\
\frac{t_0}{\left(1 + cosTheta \cdot \left(cosTheta \cdot t_0\right)\right) \cdot \left(\pi \cdot \log \left(\alpha \cdot \alpha\right)\right)}
\end{array}
\end{array}
Initial program 98.4%
Final simplification98.4%
(FPCore (cosTheta alpha) :precision binary32 (/ (+ -1.0 (* alpha alpha)) (* (* PI (log (* alpha alpha))) (- 1.0 (* cosTheta cosTheta)))))
float code(float cosTheta, float alpha) {
return (-1.0f + (alpha * alpha)) / ((((float) M_PI) * logf((alpha * alpha))) * (1.0f - (cosTheta * cosTheta)));
}
function code(cosTheta, alpha) return Float32(Float32(Float32(-1.0) + Float32(alpha * alpha)) / Float32(Float32(Float32(pi) * log(Float32(alpha * alpha))) * Float32(Float32(1.0) - Float32(cosTheta * cosTheta)))) end
function tmp = code(cosTheta, alpha) tmp = (single(-1.0) + (alpha * alpha)) / ((single(pi) * log((alpha * alpha))) * (single(1.0) - (cosTheta * cosTheta))); end
\begin{array}{l}
\\
\frac{-1 + \alpha \cdot \alpha}{\left(\pi \cdot \log \left(\alpha \cdot \alpha\right)\right) \cdot \left(1 - cosTheta \cdot cosTheta\right)}
\end{array}
Initial program 98.4%
Taylor expanded in alpha around 0 97.7%
mul-1-neg97.7%
Simplified97.7%
Final simplification97.7%
(FPCore (cosTheta alpha) :precision binary32 (* (/ (+ 1.0 alpha) 2.0) (/ (/ (+ alpha -1.0) PI) (log alpha))))
float code(float cosTheta, float alpha) {
return ((1.0f + alpha) / 2.0f) * (((alpha + -1.0f) / ((float) M_PI)) / logf(alpha));
}
function code(cosTheta, alpha) return Float32(Float32(Float32(Float32(1.0) + alpha) / Float32(2.0)) * Float32(Float32(Float32(alpha + Float32(-1.0)) / Float32(pi)) / log(alpha))) end
function tmp = code(cosTheta, alpha) tmp = ((single(1.0) + alpha) / single(2.0)) * (((alpha + single(-1.0)) / single(pi)) / log(alpha)); end
\begin{array}{l}
\\
\frac{1 + \alpha}{2} \cdot \frac{\frac{\alpha + -1}{\pi}}{\log \alpha}
\end{array}
Initial program 98.4%
associate-/r*98.4%
cancel-sign-sub98.4%
distribute-rgt-neg-out98.4%
unsub-neg98.4%
distribute-rgt-neg-out98.4%
associate-/r*98.4%
sqr-neg98.4%
sqr-neg98.4%
fma-neg98.3%
metadata-eval98.3%
associate-*l*98.3%
Simplified98.4%
Taylor expanded in cosTheta around 0 94.8%
metadata-eval94.8%
fma-neg94.7%
difference-of-sqr-194.7%
*-un-lft-identity94.7%
fma-neg94.7%
metadata-eval94.7%
fma-def94.7%
*-un-lft-identity94.7%
*-commutative94.7%
*-commutative94.7%
frac-times94.5%
associate-*l/94.4%
*-commutative94.4%
times-frac94.5%
Applied egg-rr94.5%
Final simplification94.5%
(FPCore (cosTheta alpha) :precision binary32 (* (/ (+ 1.0 alpha) (log alpha)) (/ (/ (+ alpha -1.0) PI) 2.0)))
float code(float cosTheta, float alpha) {
return ((1.0f + alpha) / logf(alpha)) * (((alpha + -1.0f) / ((float) M_PI)) / 2.0f);
}
function code(cosTheta, alpha) return Float32(Float32(Float32(Float32(1.0) + alpha) / log(alpha)) * Float32(Float32(Float32(alpha + Float32(-1.0)) / Float32(pi)) / Float32(2.0))) end
function tmp = code(cosTheta, alpha) tmp = ((single(1.0) + alpha) / log(alpha)) * (((alpha + single(-1.0)) / single(pi)) / single(2.0)); end
\begin{array}{l}
\\
\frac{1 + \alpha}{\log \alpha} \cdot \frac{\frac{\alpha + -1}{\pi}}{2}
\end{array}
Initial program 98.4%
associate-/r*98.4%
cancel-sign-sub98.4%
distribute-rgt-neg-out98.4%
unsub-neg98.4%
distribute-rgt-neg-out98.4%
associate-/r*98.4%
sqr-neg98.4%
sqr-neg98.4%
fma-neg98.3%
metadata-eval98.3%
associate-*l*98.3%
Simplified98.4%
Taylor expanded in cosTheta around 0 94.8%
metadata-eval94.8%
fma-neg94.7%
difference-of-sqr-194.7%
*-un-lft-identity94.7%
fma-neg94.7%
metadata-eval94.7%
fma-def94.7%
*-un-lft-identity94.7%
*-commutative94.7%
*-commutative94.7%
frac-times94.5%
associate-*l/94.4%
times-frac94.5%
Applied egg-rr94.5%
Final simplification94.5%
(FPCore (cosTheta alpha) :precision binary32 (* (/ (+ 1.0 alpha) (* 2.0 PI)) (/ (+ alpha -1.0) (log alpha))))
float code(float cosTheta, float alpha) {
return ((1.0f + alpha) / (2.0f * ((float) M_PI))) * ((alpha + -1.0f) / logf(alpha));
}
function code(cosTheta, alpha) return Float32(Float32(Float32(Float32(1.0) + alpha) / Float32(Float32(2.0) * Float32(pi))) * Float32(Float32(alpha + Float32(-1.0)) / log(alpha))) end
function tmp = code(cosTheta, alpha) tmp = ((single(1.0) + alpha) / (single(2.0) * single(pi))) * ((alpha + single(-1.0)) / log(alpha)); end
\begin{array}{l}
\\
\frac{1 + \alpha}{2 \cdot \pi} \cdot \frac{\alpha + -1}{\log \alpha}
\end{array}
Initial program 98.4%
associate-/r*98.4%
cancel-sign-sub98.4%
distribute-rgt-neg-out98.4%
unsub-neg98.4%
distribute-rgt-neg-out98.4%
associate-/r*98.4%
sqr-neg98.4%
sqr-neg98.4%
fma-neg98.3%
metadata-eval98.3%
associate-*l*98.3%
Simplified98.4%
Taylor expanded in cosTheta around 0 94.8%
metadata-eval94.8%
fma-neg94.7%
difference-of-sqr-194.7%
*-un-lft-identity94.7%
fma-neg94.7%
metadata-eval94.7%
fma-def94.7%
*-un-lft-identity94.7%
associate-*r*94.7%
*-commutative94.7%
times-frac94.6%
*-commutative94.6%
Applied egg-rr94.6%
Final simplification94.6%
(FPCore (cosTheta alpha) :precision binary32 (/ (- 1.0 alpha) (/ (* (log alpha) (* 2.0 PI)) (- -1.0 alpha))))
float code(float cosTheta, float alpha) {
return (1.0f - alpha) / ((logf(alpha) * (2.0f * ((float) M_PI))) / (-1.0f - alpha));
}
function code(cosTheta, alpha) return Float32(Float32(Float32(1.0) - alpha) / Float32(Float32(log(alpha) * Float32(Float32(2.0) * Float32(pi))) / Float32(Float32(-1.0) - alpha))) end
function tmp = code(cosTheta, alpha) tmp = (single(1.0) - alpha) / ((log(alpha) * (single(2.0) * single(pi))) / (single(-1.0) - alpha)); end
\begin{array}{l}
\\
\frac{1 - \alpha}{\frac{\log \alpha \cdot \left(2 \cdot \pi\right)}{-1 - \alpha}}
\end{array}
Initial program 98.4%
associate-/r*98.4%
cancel-sign-sub98.4%
distribute-rgt-neg-out98.4%
unsub-neg98.4%
distribute-rgt-neg-out98.4%
associate-/r*98.4%
sqr-neg98.4%
sqr-neg98.4%
fma-neg98.3%
metadata-eval98.3%
associate-*l*98.3%
Simplified98.4%
Taylor expanded in cosTheta around 0 94.8%
metadata-eval94.8%
fma-neg94.7%
difference-of-sqr-194.7%
*-un-lft-identity94.7%
fma-neg94.7%
metadata-eval94.7%
fma-def94.7%
*-un-lft-identity94.7%
*-commutative94.7%
*-commutative94.7%
frac-times94.5%
associate-*l/94.4%
times-frac94.5%
Applied egg-rr94.5%
associate-*l/94.4%
associate-*r/94.5%
associate-/r*94.5%
associate-/r*94.5%
associate-*r/94.7%
remove-double-neg94.7%
distribute-rgt-neg-out94.7%
*-commutative94.7%
distribute-rgt-neg-out94.7%
associate-/l*94.6%
neg-sub094.6%
metadata-eval94.6%
+-commutative94.6%
associate--r+94.6%
metadata-eval94.6%
metadata-eval94.6%
associate-*r*94.6%
*-commutative94.6%
neg-sub094.6%
Simplified94.6%
Final simplification94.6%
(FPCore (cosTheta alpha) :precision binary32 (* (/ -1.0 PI) (/ (/ 1.0 (log alpha)) 2.0)))
float code(float cosTheta, float alpha) {
return (-1.0f / ((float) M_PI)) * ((1.0f / logf(alpha)) / 2.0f);
}
function code(cosTheta, alpha) return Float32(Float32(Float32(-1.0) / Float32(pi)) * Float32(Float32(Float32(1.0) / log(alpha)) / Float32(2.0))) end
function tmp = code(cosTheta, alpha) tmp = (single(-1.0) / single(pi)) * ((single(1.0) / log(alpha)) / single(2.0)); end
\begin{array}{l}
\\
\frac{-1}{\pi} \cdot \frac{\frac{1}{\log \alpha}}{2}
\end{array}
Initial program 98.4%
associate-/r*98.4%
cancel-sign-sub98.4%
distribute-rgt-neg-out98.4%
unsub-neg98.4%
distribute-rgt-neg-out98.4%
associate-/r*98.4%
sqr-neg98.4%
sqr-neg98.4%
fma-neg98.3%
metadata-eval98.3%
associate-*l*98.3%
Simplified98.4%
Taylor expanded in cosTheta around 0 94.8%
*-un-lft-identity94.8%
metadata-eval94.8%
times-frac94.8%
*-un-lft-identity94.8%
associate-*r*94.8%
*-commutative94.8%
frac-times94.7%
associate-*l/94.9%
*-un-lft-identity94.9%
div-inv94.8%
*-commutative94.8%
times-frac94.8%
Applied egg-rr94.8%
Taylor expanded in alpha around 0 64.6%
Final simplification64.6%
(FPCore (cosTheta alpha) :precision binary32 (/ 1.0 (/ PI (/ -0.5 (log alpha)))))
float code(float cosTheta, float alpha) {
return 1.0f / (((float) M_PI) / (-0.5f / logf(alpha)));
}
function code(cosTheta, alpha) return Float32(Float32(1.0) / Float32(Float32(pi) / Float32(Float32(-0.5) / log(alpha)))) end
function tmp = code(cosTheta, alpha) tmp = single(1.0) / (single(pi) / (single(-0.5) / log(alpha))); end
\begin{array}{l}
\\
\frac{1}{\frac{\pi}{\frac{-0.5}{\log \alpha}}}
\end{array}
Initial program 98.4%
Taylor expanded in alpha around 0 66.5%
mul-1-neg66.5%
Simplified66.5%
Taylor expanded in cosTheta around 0 64.6%
clear-num64.6%
inv-pow64.6%
Applied egg-rr64.6%
unpow-164.6%
associate-/l*64.6%
Simplified64.6%
Final simplification64.6%
(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 98.4%
Taylor expanded in alpha around 0 66.5%
mul-1-neg66.5%
Simplified66.5%
Taylor expanded in cosTheta around 0 64.6%
Final simplification64.6%
herbie shell --seed 2023322
(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)))))