
(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 alpha) PI)) (+ 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 * alpha), ((float) M_PI))) * (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((Float32(alpha * alpha) ^ Float32(pi))) * 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 * alpha) ^ single(pi))) * (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({\left(\alpha \cdot \alpha\right)}^{\pi}\right) \cdot \left(1 + cosTheta \cdot \left(t_0 \cdot cosTheta\right)\right)}
\end{array}
\end{array}
Initial program 98.6%
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))) (log (pow alpha (* PI 2.0)))))))
float code(float cosTheta, float alpha) {
float t_0 = (alpha * alpha) + -1.0f;
return t_0 / ((1.0f + (cosTheta * (t_0 * cosTheta))) * logf(powf(alpha, (((float) M_PI) * 2.0f))));
}
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))) * log((alpha ^ Float32(Float32(pi) * Float32(2.0)))))) end
function tmp = code(cosTheta, alpha) t_0 = (alpha * alpha) + single(-1.0); tmp = t_0 / ((single(1.0) + (cosTheta * (t_0 * cosTheta))) * log((alpha ^ (single(pi) * single(2.0))))); 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 \log \left({\alpha}^{\left(\pi \cdot 2\right)}\right)}
\end{array}
\end{array}
Initial program 98.6%
add-log-exp98.5%
*-commutative98.5%
exp-to-pow98.7%
Applied egg-rr98.7%
Taylor expanded in alpha around 0 98.4%
associate-*r*98.4%
log-pow98.5%
log-pow98.4%
*-commutative98.4%
associate-*l*98.4%
exp-to-pow98.7%
Simplified98.7%
Final simplification98.7%
(FPCore (cosTheta alpha)
:precision binary32
(/
(+ (* alpha alpha) -1.0)
(*
(* PI (log (* alpha alpha)))
(+
1.0
(-
(+ 1.0 (+ (* (* alpha alpha) (* cosTheta cosTheta)) -1.0))
(* cosTheta cosTheta))))))
float code(float cosTheta, float alpha) {
return ((alpha * alpha) + -1.0f) / ((((float) M_PI) * logf((alpha * alpha))) * (1.0f + ((1.0f + (((alpha * alpha) * (cosTheta * cosTheta)) + -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(Float32(Float32(1.0) + Float32(Float32(Float32(alpha * alpha) * Float32(cosTheta * cosTheta)) + 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) + ((single(1.0) + (((alpha * alpha) * (cosTheta * cosTheta)) + 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 + \left(\left(1 + \left(\left(\alpha \cdot \alpha\right) \cdot \left(cosTheta \cdot cosTheta\right) + -1\right)\right) - cosTheta \cdot cosTheta\right)\right)}
\end{array}
Initial program 98.6%
fma-neg98.6%
metadata-eval98.6%
associate-*r*98.6%
*-commutative98.6%
fma-udef98.6%
distribute-lft-in98.6%
Applied egg-rr98.6%
expm1-log1p-u98.6%
expm1-udef98.5%
log1p-udef98.5%
add-exp-log98.5%
*-commutative98.5%
Applied egg-rr98.5%
associate--l+98.6%
unswap-sqr98.6%
*-commutative98.6%
*-commutative98.6%
swap-sqr98.6%
Simplified98.6%
Final simplification98.6%
(FPCore (cosTheta alpha)
:precision binary32
(/
(+ (* alpha alpha) -1.0)
(*
(* PI (log (* alpha alpha)))
(+
1.0
(- (* (* alpha alpha) (* cosTheta cosTheta)) (* cosTheta cosTheta))))))
float code(float cosTheta, float alpha) {
return ((alpha * alpha) + -1.0f) / ((((float) M_PI) * logf((alpha * alpha))) * (1.0f + (((alpha * alpha) * (cosTheta * cosTheta)) - (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(Float32(Float32(alpha * alpha) * Float32(cosTheta * cosTheta)) - Float32(cosTheta * cosTheta))))) end
function tmp = code(cosTheta, alpha) tmp = ((alpha * alpha) + single(-1.0)) / ((single(pi) * log((alpha * alpha))) * (single(1.0) + (((alpha * alpha) * (cosTheta * cosTheta)) - (cosTheta * cosTheta)))); end
\begin{array}{l}
\\
\frac{\alpha \cdot \alpha + -1}{\left(\pi \cdot \log \left(\alpha \cdot \alpha\right)\right) \cdot \left(1 + \left(\left(\alpha \cdot \alpha\right) \cdot \left(cosTheta \cdot cosTheta\right) - cosTheta \cdot cosTheta\right)\right)}
\end{array}
Initial program 98.6%
fma-neg98.6%
metadata-eval98.6%
associate-*r*98.6%
*-commutative98.6%
fma-udef98.6%
distribute-lft-in98.6%
Applied egg-rr98.6%
Final simplification98.6%
(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) (* (- 1.0 (* cosTheta cosTheta)) (* 2.0 (* PI (log alpha))))))
float code(float cosTheta, float alpha) {
return ((alpha * alpha) + -1.0f) / ((1.0f - (cosTheta * cosTheta)) * (2.0f * (((float) M_PI) * logf(alpha))));
}
function code(cosTheta, alpha) return Float32(Float32(Float32(alpha * alpha) + Float32(-1.0)) / Float32(Float32(Float32(1.0) - Float32(cosTheta * cosTheta)) * Float32(Float32(2.0) * Float32(Float32(pi) * log(alpha))))) end
function tmp = code(cosTheta, alpha) tmp = ((alpha * alpha) + single(-1.0)) / ((single(1.0) - (cosTheta * cosTheta)) * (single(2.0) * (single(pi) * log(alpha)))); end
\begin{array}{l}
\\
\frac{\alpha \cdot \alpha + -1}{\left(1 - cosTheta \cdot cosTheta\right) \cdot \left(2 \cdot \left(\pi \cdot \log \alpha\right)\right)}
\end{array}
Initial program 98.6%
Taylor expanded in alpha around inf 98.2%
Taylor expanded in alpha around 0 97.5%
Simplified97.5%
Taylor expanded in alpha around 0 97.7%
Final simplification97.7%
(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 97.8%
Simplified97.8%
Final simplification97.8%
(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%
difference-of-sqr-198.2%
*-commutative98.2%
times-frac98.0%
*-commutative98.0%
times-frac98.2%
difference-of-sqr-198.6%
associate-/l/98.6%
log-prod98.6%
count-298.6%
*-commutative98.6%
fma-neg98.6%
metadata-eval98.6%
+-commutative98.6%
Simplified98.7%
associate-/l/98.6%
fma-udef98.5%
difference-of-sqr--198.3%
times-frac98.2%
sub-neg98.2%
metadata-eval98.2%
Applied egg-rr98.2%
Taylor expanded in cosTheta around 0 95.8%
associate-/l*95.6%
+-commutative95.6%
associate-/l*95.8%
*-commutative95.8%
sub-neg95.8%
metadata-eval95.8%
Simplified95.8%
Final simplification95.8%
(FPCore (cosTheta alpha) :precision binary32 (/ (/ -0.5 (log alpha)) (* PI (- 1.0 (* cosTheta cosTheta)))))
float code(float cosTheta, float alpha) {
return (-0.5f / logf(alpha)) / (((float) M_PI) * (1.0f - (cosTheta * cosTheta)));
}
function code(cosTheta, alpha) return Float32(Float32(Float32(-0.5) / log(alpha)) / Float32(Float32(pi) * Float32(Float32(1.0) - Float32(cosTheta * cosTheta)))) end
function tmp = code(cosTheta, alpha) tmp = (single(-0.5) / log(alpha)) / (single(pi) * (single(1.0) - (cosTheta * cosTheta))); end
\begin{array}{l}
\\
\frac{\frac{-0.5}{\log \alpha}}{\pi \cdot \left(1 - cosTheta \cdot cosTheta\right)}
\end{array}
Initial program 98.6%
add-log-exp98.5%
*-commutative98.5%
exp-to-pow98.7%
Applied egg-rr98.7%
Taylor expanded in alpha around 0 68.2%
associate-/r*68.2%
*-commutative68.2%
mul-1-neg68.2%
unsub-neg68.2%
unpow268.2%
Simplified68.2%
Final simplification68.2%
(FPCore (cosTheta alpha) :precision binary32 (/ -0.5 (* (log alpha) (* PI (- 1.0 (* cosTheta cosTheta))))))
float code(float cosTheta, float alpha) {
return -0.5f / (logf(alpha) * (((float) M_PI) * (1.0f - (cosTheta * cosTheta))));
}
function code(cosTheta, alpha) return Float32(Float32(-0.5) / Float32(log(alpha) * Float32(Float32(pi) * Float32(Float32(1.0) - Float32(cosTheta * cosTheta))))) end
function tmp = code(cosTheta, alpha) tmp = single(-0.5) / (log(alpha) * (single(pi) * (single(1.0) - (cosTheta * cosTheta)))); end
\begin{array}{l}
\\
\frac{-0.5}{\log \alpha \cdot \left(\pi \cdot \left(1 - cosTheta \cdot cosTheta\right)\right)}
\end{array}
Initial program 98.6%
Taylor expanded in alpha around 0 68.2%
Simplified68.2%
Final simplification68.2%
(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%
associate-/r*98.6%
difference-of-sqr-198.2%
*-commutative98.2%
times-frac98.0%
*-commutative98.0%
times-frac98.2%
difference-of-sqr-198.6%
associate-/l/98.6%
log-prod98.6%
count-298.6%
*-commutative98.6%
fma-neg98.6%
metadata-eval98.6%
+-commutative98.6%
Simplified98.7%
Taylor expanded in alpha around 0 68.3%
Simplified68.3%
Taylor expanded in cosTheta around 0 67.4%
Taylor expanded in alpha around 0 67.4%
Final simplification67.4%
herbie shell --seed 2023174
(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)))))