
(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 10 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 (pow alpha 2.0) 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(powf(alpha, 2.0f), ((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(((alpha ^ Float32(2.0)) ^ 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 ^ single(2.0)) ^ 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}^{2}\right)}^{\pi}\right) \cdot \left(1 + cosTheta \cdot \left(t\_0 \cdot cosTheta\right)\right)}
\end{array}
\end{array}
Initial program 98.5%
*-commutative98.5%
add-log-exp98.4%
exp-to-pow98.6%
pow298.6%
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))) (log (pow alpha (* 2.0 PI)))))))
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, (2.0f * ((float) M_PI)))));
}
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(2.0) * Float32(pi)))))) 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(2.0) * single(pi))))); 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(2 \cdot \pi\right)}\right)}
\end{array}
\end{array}
Initial program 98.5%
*-commutative98.5%
add-log-exp98.4%
exp-to-pow98.6%
pow298.6%
Applied egg-rr98.6%
Taylor expanded in alpha around 0 98.4%
associate-*r*98.4%
*-commutative98.4%
exp-to-pow98.5%
Simplified98.5%
Final simplification98.5%
(FPCore (cosTheta alpha) :precision binary32 (/ (+ (* alpha alpha) -1.0) (* (* PI (log (* alpha alpha))) (+ 1.0 (* cosTheta (* cosTheta (fma alpha alpha -1.0)))))))
float code(float cosTheta, float alpha) {
return ((alpha * alpha) + -1.0f) / ((((float) M_PI) * logf((alpha * alpha))) * (1.0f + (cosTheta * (cosTheta * fmaf(alpha, alpha, -1.0f)))));
}
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 * Float32(cosTheta * fma(alpha, alpha, Float32(-1.0))))))) end
\begin{array}{l}
\\
\frac{\alpha \cdot \alpha + -1}{\left(\pi \cdot \log \left(\alpha \cdot \alpha\right)\right) \cdot \left(1 + cosTheta \cdot \left(cosTheta \cdot \mathsf{fma}\left(\alpha, \alpha, -1\right)\right)\right)}
\end{array}
Initial program 98.5%
Taylor expanded in alpha around 0 98.5%
+-commutative98.5%
distribute-rgt-out98.5%
unpow298.5%
fma-udef98.5%
Simplified98.5%
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 98.5%
Final simplification98.5%
(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 98.5%
Taylor expanded in alpha around 0 97.2%
mul-1-neg97.2%
Simplified97.2%
Final simplification97.2%
(FPCore (cosTheta alpha) :precision binary32 (/ (/ 1.0 (/ (log alpha) (/ -0.5 PI))) (- 1.0 (* cosTheta cosTheta))))
float code(float cosTheta, float alpha) {
return (1.0f / (logf(alpha) / (-0.5f / ((float) M_PI)))) / (1.0f - (cosTheta * cosTheta));
}
function code(cosTheta, alpha) return Float32(Float32(Float32(1.0) / Float32(log(alpha) / Float32(Float32(-0.5) / Float32(pi)))) / Float32(Float32(1.0) - Float32(cosTheta * cosTheta))) end
function tmp = code(cosTheta, alpha) tmp = (single(1.0) / (log(alpha) / (single(-0.5) / single(pi)))) / (single(1.0) - (cosTheta * cosTheta)); end
\begin{array}{l}
\\
\frac{\frac{1}{\frac{\log \alpha}{\frac{-0.5}{\pi}}}}{1 - cosTheta \cdot cosTheta}
\end{array}
Initial program 98.5%
associate-/r*98.4%
sqr-neg98.4%
sqr-neg98.4%
fma-neg98.3%
metadata-eval98.3%
*-commutative98.3%
cancel-sign-sub98.3%
cancel-sign-sub-inv98.3%
remove-double-neg98.3%
sqr-neg98.3%
sqr-neg98.3%
fma-neg98.3%
metadata-eval98.3%
Simplified98.3%
Taylor expanded in alpha around 0 66.2%
associate-/r*66.2%
Simplified66.2%
Taylor expanded in alpha around 0 66.2%
mul-1-neg66.2%
Simplified66.2%
clear-num66.2%
inv-pow66.2%
Applied egg-rr66.2%
unpow-166.2%
Simplified66.2%
Final simplification66.2%
(FPCore (cosTheta alpha) :precision binary32 (/ (/ -0.5 (* PI (log alpha))) (- 1.0 (* cosTheta cosTheta))))
float code(float cosTheta, float alpha) {
return (-0.5f / (((float) M_PI) * logf(alpha))) / (1.0f - (cosTheta * cosTheta));
}
function code(cosTheta, alpha) return Float32(Float32(Float32(-0.5) / Float32(Float32(pi) * log(alpha))) / Float32(Float32(1.0) - Float32(cosTheta * cosTheta))) end
function tmp = code(cosTheta, alpha) tmp = (single(-0.5) / (single(pi) * log(alpha))) / (single(1.0) - (cosTheta * cosTheta)); end
\begin{array}{l}
\\
\frac{\frac{-0.5}{\pi \cdot \log \alpha}}{1 - cosTheta \cdot cosTheta}
\end{array}
Initial program 98.5%
associate-/r*98.4%
sqr-neg98.4%
sqr-neg98.4%
fma-neg98.3%
metadata-eval98.3%
*-commutative98.3%
cancel-sign-sub98.3%
cancel-sign-sub-inv98.3%
remove-double-neg98.3%
sqr-neg98.3%
sqr-neg98.3%
fma-neg98.3%
metadata-eval98.3%
Simplified98.3%
Taylor expanded in alpha around 0 66.2%
associate-/r*66.2%
Simplified66.2%
Taylor expanded in alpha around 0 66.2%
mul-1-neg66.2%
Simplified66.2%
Taylor expanded in alpha around 0 66.1%
Final simplification66.1%
(FPCore (cosTheta alpha) :precision binary32 (/ (/ (/ -0.5 PI) (log alpha)) (- 1.0 (* cosTheta cosTheta))))
float code(float cosTheta, float alpha) {
return ((-0.5f / ((float) M_PI)) / logf(alpha)) / (1.0f - (cosTheta * cosTheta));
}
function code(cosTheta, alpha) return Float32(Float32(Float32(Float32(-0.5) / Float32(pi)) / log(alpha)) / Float32(Float32(1.0) - Float32(cosTheta * cosTheta))) end
function tmp = code(cosTheta, alpha) tmp = ((single(-0.5) / single(pi)) / log(alpha)) / (single(1.0) - (cosTheta * cosTheta)); end
\begin{array}{l}
\\
\frac{\frac{\frac{-0.5}{\pi}}{\log \alpha}}{1 - cosTheta \cdot cosTheta}
\end{array}
Initial program 98.5%
associate-/r*98.4%
sqr-neg98.4%
sqr-neg98.4%
fma-neg98.3%
metadata-eval98.3%
*-commutative98.3%
cancel-sign-sub98.3%
cancel-sign-sub-inv98.3%
remove-double-neg98.3%
sqr-neg98.3%
sqr-neg98.3%
fma-neg98.3%
metadata-eval98.3%
Simplified98.3%
Taylor expanded in alpha around 0 66.2%
associate-/r*66.2%
Simplified66.2%
Taylor expanded in alpha around 0 66.2%
mul-1-neg66.2%
Simplified66.2%
Final simplification66.2%
(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(Float32(0.5) / Float32(pi)) / Float32(-log(alpha))) end
function tmp = code(cosTheta, alpha) tmp = (single(0.5) / single(pi)) / -log(alpha); end
\begin{array}{l}
\\
\frac{\frac{0.5}{\pi}}{-\log \alpha}
\end{array}
Initial program 98.5%
associate-/r*98.4%
sqr-neg98.4%
sqr-neg98.4%
fma-neg98.3%
metadata-eval98.3%
*-commutative98.3%
cancel-sign-sub98.3%
cancel-sign-sub-inv98.3%
remove-double-neg98.3%
sqr-neg98.3%
sqr-neg98.3%
fma-neg98.3%
metadata-eval98.3%
Simplified98.3%
Taylor expanded in alpha around 0 66.2%
associate-/r*66.2%
Simplified66.2%
Taylor expanded in alpha around 0 66.2%
mul-1-neg66.2%
Simplified66.2%
Taylor expanded in cosTheta around 0 64.9%
Taylor expanded in alpha around inf 64.9%
log-rec64.9%
associate-/r*64.9%
Simplified64.9%
Final simplification64.9%
(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 98.5%
associate-/r*98.4%
sqr-neg98.4%
sqr-neg98.4%
fma-neg98.3%
metadata-eval98.3%
*-commutative98.3%
cancel-sign-sub98.3%
cancel-sign-sub-inv98.3%
remove-double-neg98.3%
sqr-neg98.3%
sqr-neg98.3%
fma-neg98.3%
metadata-eval98.3%
Simplified98.3%
Taylor expanded in alpha around 0 66.2%
associate-/r*66.2%
Simplified66.2%
Taylor expanded in alpha around 0 66.2%
mul-1-neg66.2%
Simplified66.2%
Taylor expanded in cosTheta around 0 64.9%
Final simplification64.9%
herbie shell --seed 2024040
(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)))))