
(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 8 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 (* (* t_0 cosTheta) 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 + ((t_0 * cosTheta) * 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(Float32(t_0 * cosTheta) * 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) + ((t_0 * cosTheta) * 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 + \left(t\_0 \cdot cosTheta\right) \cdot cosTheta\right)}
\end{array}
\end{array}
Initial program 98.6%
lift-PI.f32N/A
lift-*.f32N/A
lift-log.f32N/A
log-pow-revN/A
lift-*.f32N/A
pow2N/A
lower-log.f32N/A
lower-pow.f32N/A
pow2N/A
lift-*.f32N/A
lift-PI.f3298.7
Applied rewrites98.7%
(FPCore (cosTheta alpha)
:precision binary32
(let* ((t_0 (- (* alpha alpha) 1.0)))
(/
t_0
(* PI (* (log (* alpha alpha)) (fma (* cosTheta cosTheta) t_0 1.0))))))
float code(float cosTheta, float alpha) {
float t_0 = (alpha * alpha) - 1.0f;
return t_0 / (((float) M_PI) * (logf((alpha * alpha)) * fmaf((cosTheta * cosTheta), t_0, 1.0f)));
}
function code(cosTheta, alpha) t_0 = Float32(Float32(alpha * alpha) - Float32(1.0)) return Float32(t_0 / Float32(Float32(pi) * Float32(log(Float32(alpha * alpha)) * fma(Float32(cosTheta * cosTheta), t_0, Float32(1.0))))) end
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \alpha \cdot \alpha - 1\\
\frac{t\_0}{\pi \cdot \left(\log \left(\alpha \cdot \alpha\right) \cdot \mathsf{fma}\left(cosTheta \cdot cosTheta, t\_0, 1\right)\right)}
\end{array}
\end{array}
Initial program 98.6%
lift-*.f32N/A
lift-PI.f32N/A
lift-*.f32N/A
lift-log.f32N/A
lift-*.f32N/A
pow2N/A
lift-+.f32N/A
lift-*.f32N/A
lift-*.f32N/A
lift--.f32N/A
lift-*.f32N/A
associate-*l*N/A
lower-*.f32N/A
lift-PI.f32N/A
lower-*.f32N/A
Applied rewrites98.6%
(FPCore (cosTheta alpha) :precision binary32 (/ (- (* alpha alpha) 1.0) (* PI (* (log (* alpha alpha)) (fma (* cosTheta cosTheta) -1.0 1.0)))))
float code(float cosTheta, float alpha) {
return ((alpha * alpha) - 1.0f) / (((float) M_PI) * (logf((alpha * alpha)) * fmaf((cosTheta * cosTheta), -1.0f, 1.0f)));
}
function code(cosTheta, alpha) return Float32(Float32(Float32(alpha * alpha) - Float32(1.0)) / Float32(Float32(pi) * Float32(log(Float32(alpha * alpha)) * fma(Float32(cosTheta * cosTheta), Float32(-1.0), Float32(1.0))))) end
\begin{array}{l}
\\
\frac{\alpha \cdot \alpha - 1}{\pi \cdot \left(\log \left(\alpha \cdot \alpha\right) \cdot \mathsf{fma}\left(cosTheta \cdot cosTheta, -1, 1\right)\right)}
\end{array}
Initial program 98.6%
lift-*.f32N/A
lift-PI.f32N/A
lift-*.f32N/A
lift-log.f32N/A
lift-*.f32N/A
pow2N/A
lift-+.f32N/A
lift-*.f32N/A
lift-*.f32N/A
lift--.f32N/A
lift-*.f32N/A
associate-*l*N/A
lower-*.f32N/A
lift-PI.f32N/A
lower-*.f32N/A
Applied rewrites98.6%
Taylor expanded in alpha around 0
Applied rewrites97.8%
(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(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 + \left(-cosTheta\right) \cdot cosTheta\right)}
\end{array}
Initial program 98.6%
Taylor expanded in alpha around 0
mul-1-negN/A
lower-neg.f3297.8
Applied rewrites97.8%
(FPCore (cosTheta alpha) :precision binary32 (/ (- (* alpha alpha) 1.0) (* PI (log (* alpha alpha)))))
float code(float cosTheta, float alpha) {
return ((alpha * alpha) - 1.0f) / (((float) M_PI) * logf((alpha * alpha)));
}
function code(cosTheta, alpha) return Float32(Float32(Float32(alpha * alpha) - Float32(1.0)) / Float32(Float32(pi) * log(Float32(alpha * alpha)))) end
function tmp = code(cosTheta, alpha) tmp = ((alpha * alpha) - single(1.0)) / (single(pi) * log((alpha * alpha))); end
\begin{array}{l}
\\
\frac{\alpha \cdot \alpha - 1}{\pi \cdot \log \left(\alpha \cdot \alpha\right)}
\end{array}
Initial program 98.6%
lift-*.f32N/A
lift-PI.f32N/A
lift-*.f32N/A
lift-log.f32N/A
lift-*.f32N/A
pow2N/A
lift-+.f32N/A
lift-*.f32N/A
lift-*.f32N/A
lift--.f32N/A
lift-*.f32N/A
associate-*l*N/A
lower-*.f32N/A
lift-PI.f32N/A
lower-*.f32N/A
Applied rewrites98.6%
Taylor expanded in cosTheta around 0
lower-log.f32N/A
pow2N/A
lift-*.f3296.2
Applied rewrites96.2%
(FPCore (cosTheta alpha) :precision binary32 (/ (- (* alpha alpha) 1.0) (* (* 2.0 PI) (log alpha))))
float code(float cosTheta, float alpha) {
return ((alpha * alpha) - 1.0f) / ((2.0f * ((float) M_PI)) * logf(alpha));
}
function code(cosTheta, alpha) return Float32(Float32(Float32(alpha * alpha) - Float32(1.0)) / Float32(Float32(Float32(2.0) * Float32(pi)) * log(alpha))) end
function tmp = code(cosTheta, alpha) tmp = ((alpha * alpha) - single(1.0)) / ((single(2.0) * single(pi)) * log(alpha)); end
\begin{array}{l}
\\
\frac{\alpha \cdot \alpha - 1}{\left(2 \cdot \pi\right) \cdot \log \alpha}
\end{array}
Initial program 98.6%
lift-PI.f32N/A
lift-*.f32N/A
lift-log.f32N/A
log-pow-revN/A
lift-*.f32N/A
pow2N/A
lower-log.f32N/A
lower-pow.f32N/A
pow2N/A
lift-*.f32N/A
lift-PI.f3298.7
Applied rewrites98.7%
Taylor expanded in cosTheta around 0
Applied rewrites96.1%
(FPCore (cosTheta alpha) :precision binary32 (/ -1.0 (* PI (* (log alpha) 2.0))))
float code(float cosTheta, float alpha) {
return -1.0f / (((float) M_PI) * (logf(alpha) * 2.0f));
}
function code(cosTheta, alpha) return Float32(Float32(-1.0) / Float32(Float32(pi) * Float32(log(alpha) * Float32(2.0)))) end
function tmp = code(cosTheta, alpha) tmp = single(-1.0) / (single(pi) * (log(alpha) * single(2.0))); end
\begin{array}{l}
\\
\frac{-1}{\pi \cdot \left(\log \alpha \cdot 2\right)}
\end{array}
Initial program 98.6%
lift-*.f32N/A
lift-PI.f32N/A
lift-*.f32N/A
lift-log.f32N/A
lift-*.f32N/A
pow2N/A
lift-+.f32N/A
lift-*.f32N/A
lift-*.f32N/A
lift--.f32N/A
lift-*.f32N/A
associate-*l*N/A
lower-*.f32N/A
lift-PI.f32N/A
lower-*.f32N/A
Applied rewrites98.6%
Taylor expanded in alpha around 0
Applied rewrites67.8%
Taylor expanded in cosTheta around 0
lower-log.f32N/A
pow2N/A
lift-*.f3266.8
Applied rewrites66.8%
lift-log.f32N/A
lift-*.f32N/A
log-prodN/A
count-2-revN/A
*-commutativeN/A
lower-*.f32N/A
lift-log.f3266.8
Applied rewrites66.8%
(FPCore (cosTheta alpha) :precision binary32 (/ -1.0 (* PI (log (* alpha alpha)))))
float code(float cosTheta, float alpha) {
return -1.0f / (((float) M_PI) * logf((alpha * alpha)));
}
function code(cosTheta, alpha) return Float32(Float32(-1.0) / Float32(Float32(pi) * log(Float32(alpha * alpha)))) end
function tmp = code(cosTheta, alpha) tmp = single(-1.0) / (single(pi) * log((alpha * alpha))); end
\begin{array}{l}
\\
\frac{-1}{\pi \cdot \log \left(\alpha \cdot \alpha\right)}
\end{array}
Initial program 98.6%
lift-*.f32N/A
lift-PI.f32N/A
lift-*.f32N/A
lift-log.f32N/A
lift-*.f32N/A
pow2N/A
lift-+.f32N/A
lift-*.f32N/A
lift-*.f32N/A
lift--.f32N/A
lift-*.f32N/A
associate-*l*N/A
lower-*.f32N/A
lift-PI.f32N/A
lower-*.f32N/A
Applied rewrites98.6%
Taylor expanded in alpha around 0
Applied rewrites67.8%
Taylor expanded in cosTheta around 0
lower-log.f32N/A
pow2N/A
lift-*.f3266.8
Applied rewrites66.8%
herbie shell --seed 2025057
(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)))))