
(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}
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
(/
(- (* alpha alpha) 1.0)
(log
(pow
alpha
(* (+ PI PI) (fma (* cosTheta cosTheta) (fma alpha alpha -1.0) 1.0))))))
float code(float cosTheta, float alpha) {
return ((alpha * alpha) - 1.0f) / logf(powf(alpha, ((((float) M_PI) + ((float) M_PI)) * fmaf((cosTheta * cosTheta), fmaf(alpha, alpha, -1.0f), 1.0f))));
}
function code(cosTheta, alpha) return Float32(Float32(Float32(alpha * alpha) - Float32(1.0)) / log((alpha ^ Float32(Float32(Float32(pi) + Float32(pi)) * fma(Float32(cosTheta * cosTheta), fma(alpha, alpha, Float32(-1.0)), Float32(1.0)))))) end
\begin{array}{l}
\\
\frac{\alpha \cdot \alpha - 1}{\log \left({\alpha}^{\left(\left(\pi + \pi\right) \cdot \mathsf{fma}\left(cosTheta \cdot cosTheta, \mathsf{fma}\left(\alpha, \alpha, -1\right), 1\right)\right)}\right)}
\end{array}
Initial program 98.5%
Applied rewrites98.6%
(FPCore (cosTheta alpha) :precision binary32 (/ (/ (fma alpha alpha -1.0) PI) (* (* (log alpha) 2.0) (fma (* cosTheta cosTheta) (fma alpha alpha -1.0) 1.0))))
float code(float cosTheta, float alpha) {
return (fmaf(alpha, alpha, -1.0f) / ((float) M_PI)) / ((logf(alpha) * 2.0f) * fmaf((cosTheta * cosTheta), fmaf(alpha, alpha, -1.0f), 1.0f));
}
function code(cosTheta, alpha) return Float32(Float32(fma(alpha, alpha, Float32(-1.0)) / Float32(pi)) / Float32(Float32(log(alpha) * Float32(2.0)) * fma(Float32(cosTheta * cosTheta), fma(alpha, alpha, Float32(-1.0)), Float32(1.0)))) end
\begin{array}{l}
\\
\frac{\frac{\mathsf{fma}\left(\alpha, \alpha, -1\right)}{\pi}}{\left(\log \alpha \cdot 2\right) \cdot \mathsf{fma}\left(cosTheta \cdot cosTheta, \mathsf{fma}\left(\alpha, \alpha, -1\right), 1\right)}
\end{array}
Initial program 98.5%
lift-/.f32N/A
lift-*.f32N/A
lift--.f32N/A
lift-*.f32N/A
lift-PI.f32N/A
lift-*.f32N/A
lift-*.f32N/A
lift-log.f32N/A
lift-+.f32N/A
lift-*.f32N/A
lift-*.f32N/A
lift-*.f32N/A
lift--.f32N/A
Applied rewrites98.5%
(FPCore (cosTheta alpha) :precision binary32 (/ (- (* alpha alpha) 1.0) (* (* PI (log (* alpha alpha))) (fma (fma alpha alpha -1.0) (* cosTheta cosTheta) 1.0))))
float code(float cosTheta, float alpha) {
return ((alpha * alpha) - 1.0f) / ((((float) M_PI) * logf((alpha * alpha))) * fmaf(fmaf(alpha, alpha, -1.0f), (cosTheta * cosTheta), 1.0f));
}
function code(cosTheta, alpha) return Float32(Float32(Float32(alpha * alpha) - Float32(1.0)) / Float32(Float32(Float32(pi) * log(Float32(alpha * alpha))) * fma(fma(alpha, alpha, Float32(-1.0)), Float32(cosTheta * cosTheta), Float32(1.0)))) end
\begin{array}{l}
\\
\frac{\alpha \cdot \alpha - 1}{\left(\pi \cdot \log \left(\alpha \cdot \alpha\right)\right) \cdot \mathsf{fma}\left(\mathsf{fma}\left(\alpha, \alpha, -1\right), cosTheta \cdot cosTheta, 1\right)}
\end{array}
Initial program 98.5%
lift-+.f32N/A
lift-*.f32N/A
lift-*.f32N/A
lift-*.f32N/A
lift--.f32N/A
fp-cancel-sign-sub-invN/A
fp-cancel-sub-sign-invN/A
+-commutativeN/A
remove-double-negN/A
lift--.f32N/A
lift-*.f32N/A
lift-*.f32N/A
lift-*.f32N/A
lift-*.f32N/A
lift--.f32N/A
associate-*l*N/A
pow2N/A
unpow2N/A
Applied rewrites98.5%
(FPCore (cosTheta alpha) :precision binary32 (/ (/ (fma alpha alpha -1.0) (fma (* cosTheta cosTheta) (fma alpha alpha -1.0) 1.0)) (* (+ PI PI) (log alpha))))
float code(float cosTheta, float alpha) {
return (fmaf(alpha, alpha, -1.0f) / fmaf((cosTheta * cosTheta), fmaf(alpha, alpha, -1.0f), 1.0f)) / ((((float) M_PI) + ((float) M_PI)) * logf(alpha));
}
function code(cosTheta, alpha) return Float32(Float32(fma(alpha, alpha, Float32(-1.0)) / fma(Float32(cosTheta * cosTheta), fma(alpha, alpha, Float32(-1.0)), Float32(1.0))) / Float32(Float32(Float32(pi) + Float32(pi)) * log(alpha))) end
\begin{array}{l}
\\
\frac{\frac{\mathsf{fma}\left(\alpha, \alpha, -1\right)}{\mathsf{fma}\left(cosTheta \cdot cosTheta, \mathsf{fma}\left(\alpha, \alpha, -1\right), 1\right)}}{\left(\pi + \pi\right) \cdot \log \alpha}
\end{array}
Initial program 98.5%
Applied rewrites98.5%
(FPCore (cosTheta alpha) :precision binary32 (/ (fma alpha alpha -1.0) (* (* (+ PI PI) (log alpha)) (fma (* cosTheta cosTheta) (fma alpha alpha -1.0) 1.0))))
float code(float cosTheta, float alpha) {
return fmaf(alpha, alpha, -1.0f) / (((((float) M_PI) + ((float) M_PI)) * logf(alpha)) * fmaf((cosTheta * cosTheta), fmaf(alpha, alpha, -1.0f), 1.0f));
}
function code(cosTheta, alpha) return Float32(fma(alpha, alpha, Float32(-1.0)) / Float32(Float32(Float32(Float32(pi) + Float32(pi)) * log(alpha)) * fma(Float32(cosTheta * cosTheta), fma(alpha, alpha, Float32(-1.0)), Float32(1.0)))) end
\begin{array}{l}
\\
\frac{\mathsf{fma}\left(\alpha, \alpha, -1\right)}{\left(\left(\pi + \pi\right) \cdot \log \alpha\right) \cdot \mathsf{fma}\left(cosTheta \cdot cosTheta, \mathsf{fma}\left(\alpha, \alpha, -1\right), 1\right)}
\end{array}
Initial program 98.5%
lift-*.f32N/A
lift--.f32N/A
difference-of-sqr-1N/A
difference-of-sqr--1-revN/A
lower-fma.f3298.4
lift-PI.f32N/A
lift-*.f32N/A
lift-*.f32N/A
lift-log.f32N/A
pow2N/A
log-pow-revN/A
associate-*r*N/A
*-commutativeN/A
lower-*.f32N/A
count-2-revN/A
lower-+.f32N/A
lift-PI.f32N/A
lift-PI.f32N/A
lower-log.f3298.5
lift-+.f32N/A
lift-*.f32N/A
Applied rewrites98.5%
(FPCore (cosTheta alpha) :precision binary32 (/ (/ (fma alpha alpha -1.0) PI) (* -2.0 (* (fma cosTheta cosTheta -1.0) (log alpha)))))
float code(float cosTheta, float alpha) {
return (fmaf(alpha, alpha, -1.0f) / ((float) M_PI)) / (-2.0f * (fmaf(cosTheta, cosTheta, -1.0f) * logf(alpha)));
}
function code(cosTheta, alpha) return Float32(Float32(fma(alpha, alpha, Float32(-1.0)) / Float32(pi)) / Float32(Float32(-2.0) * Float32(fma(cosTheta, cosTheta, Float32(-1.0)) * log(alpha)))) end
\begin{array}{l}
\\
\frac{\frac{\mathsf{fma}\left(\alpha, \alpha, -1\right)}{\pi}}{-2 \cdot \left(\mathsf{fma}\left(cosTheta, cosTheta, -1\right) \cdot \log \alpha\right)}
\end{array}
Initial program 98.5%
lift-/.f32N/A
lift-*.f32N/A
lift--.f32N/A
lift-*.f32N/A
lift-PI.f32N/A
lift-*.f32N/A
lift-*.f32N/A
lift-log.f32N/A
lift-+.f32N/A
lift-*.f32N/A
lift-*.f32N/A
lift-*.f32N/A
lift--.f32N/A
Applied rewrites98.5%
Taylor expanded in alpha around 0
Applied rewrites97.4%
(FPCore (cosTheta alpha) :precision binary32 (/ (fma alpha alpha -1.0) (* (* (+ PI PI) (log alpha)) (- 1.0 (* cosTheta cosTheta)))))
float code(float cosTheta, float alpha) {
return fmaf(alpha, alpha, -1.0f) / (((((float) M_PI) + ((float) M_PI)) * logf(alpha)) * (1.0f - (cosTheta * cosTheta)));
}
function code(cosTheta, alpha) return Float32(fma(alpha, alpha, Float32(-1.0)) / Float32(Float32(Float32(Float32(pi) + Float32(pi)) * log(alpha)) * Float32(Float32(1.0) - Float32(cosTheta * cosTheta)))) end
\begin{array}{l}
\\
\frac{\mathsf{fma}\left(\alpha, \alpha, -1\right)}{\left(\left(\pi + \pi\right) \cdot \log \alpha\right) \cdot \left(1 - cosTheta \cdot cosTheta\right)}
\end{array}
Initial program 98.5%
lift-*.f32N/A
lift--.f32N/A
difference-of-sqr-1N/A
difference-of-sqr--1-revN/A
lower-fma.f3298.4
lift-PI.f32N/A
lift-*.f32N/A
lift-*.f32N/A
lift-log.f32N/A
pow2N/A
log-pow-revN/A
associate-*r*N/A
*-commutativeN/A
lower-*.f32N/A
count-2-revN/A
lower-+.f32N/A
lift-PI.f32N/A
lift-PI.f32N/A
lower-log.f3298.5
lift-+.f32N/A
lift-*.f32N/A
Applied rewrites98.5%
Taylor expanded in alpha around 0
mul-1-negN/A
pow2N/A
distribute-lft-neg-inN/A
fp-cancel-sub-sign-invN/A
pow2N/A
lower--.f32N/A
pow2N/A
lift-*.f3297.5
Applied rewrites97.5%
(FPCore (cosTheta alpha) :precision binary32 (/ (/ (fma alpha alpha -1.0) PI) (* (log alpha) 2.0)))
float code(float cosTheta, float alpha) {
return (fmaf(alpha, alpha, -1.0f) / ((float) M_PI)) / (logf(alpha) * 2.0f);
}
function code(cosTheta, alpha) return Float32(Float32(fma(alpha, alpha, Float32(-1.0)) / Float32(pi)) / Float32(log(alpha) * Float32(2.0))) end
\begin{array}{l}
\\
\frac{\frac{\mathsf{fma}\left(\alpha, \alpha, -1\right)}{\pi}}{\log \alpha \cdot 2}
\end{array}
Initial program 98.5%
lift-/.f32N/A
lift-*.f32N/A
lift--.f32N/A
lift-*.f32N/A
lift-PI.f32N/A
lift-*.f32N/A
lift-*.f32N/A
lift-log.f32N/A
lift-+.f32N/A
lift-*.f32N/A
lift-*.f32N/A
lift-*.f32N/A
lift--.f32N/A
Applied rewrites98.5%
Taylor expanded in cosTheta around 0
*-commutativeN/A
lift-log.f32N/A
lift-*.f3295.1
Applied rewrites95.1%
(FPCore (cosTheta alpha) :precision binary32 (/ (fma alpha alpha -1.0) (* (+ PI PI) (log alpha))))
float code(float cosTheta, float alpha) {
return fmaf(alpha, alpha, -1.0f) / ((((float) M_PI) + ((float) M_PI)) * logf(alpha));
}
function code(cosTheta, alpha) return Float32(fma(alpha, alpha, Float32(-1.0)) / Float32(Float32(Float32(pi) + Float32(pi)) * log(alpha))) end
\begin{array}{l}
\\
\frac{\mathsf{fma}\left(\alpha, \alpha, -1\right)}{\left(\pi + \pi\right) \cdot \log \alpha}
\end{array}
Initial program 98.5%
Taylor expanded in cosTheta around 0
lower-/.f32N/A
pow2N/A
difference-of-sqr-1N/A
difference-of-sqr--1-revN/A
lower-fma.f32N/A
log-pow-revN/A
associate-*r*N/A
*-commutativeN/A
lower-*.f32N/A
count-2-revN/A
lower-+.f32N/A
lift-PI.f32N/A
lift-PI.f32N/A
lower-log.f3295.1
Applied rewrites95.1%
(FPCore (cosTheta alpha) :precision binary32 (* (/ -0.5 (log alpha)) (/ 1.0 PI)))
float code(float cosTheta, float alpha) {
return (-0.5f / logf(alpha)) * (1.0f / ((float) M_PI));
}
function code(cosTheta, alpha) return Float32(Float32(Float32(-0.5) / log(alpha)) * Float32(Float32(1.0) / Float32(pi))) end
function tmp = code(cosTheta, alpha) tmp = (single(-0.5) / log(alpha)) * (single(1.0) / single(pi)); end
\begin{array}{l}
\\
\frac{-0.5}{\log \alpha} \cdot \frac{1}{\pi}
\end{array}
Initial program 98.5%
Taylor expanded in alpha around 0
frac-2negN/A
metadata-evalN/A
distribute-rgt-neg-inN/A
distribute-lft-neg-outN/A
log-recN/A
lower-/.f32N/A
associate-*r*N/A
log-recN/A
distribute-rgt-neg-outN/A
distribute-lft-neg-inN/A
distribute-rgt-neg-inN/A
lower-*.f32N/A
Applied rewrites66.8%
Taylor expanded in cosTheta around 0
lower-/.f32N/A
*-commutativeN/A
lift-log.f32N/A
lift-*.f32N/A
lift-PI.f3265.4
Applied rewrites65.4%
lift-/.f32N/A
lift-PI.f32N/A
lift-*.f32N/A
lift-log.f32N/A
associate-/r*N/A
frac-2negN/A
metadata-evalN/A
log-recN/A
associate-/l/N/A
metadata-evalN/A
times-fracN/A
metadata-evalN/A
log-recN/A
frac-2negN/A
lower-*.f32N/A
lower-/.f32N/A
lift-log.f32N/A
lower-/.f32N/A
lift-PI.f3265.5
Applied rewrites65.5%
(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)) / 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%
Taylor expanded in alpha around 0
frac-2negN/A
metadata-evalN/A
distribute-rgt-neg-inN/A
distribute-lft-neg-outN/A
log-recN/A
lower-/.f32N/A
associate-*r*N/A
log-recN/A
distribute-rgt-neg-outN/A
distribute-lft-neg-inN/A
distribute-rgt-neg-inN/A
lower-*.f32N/A
Applied rewrites66.8%
Taylor expanded in cosTheta around 0
lower-/.f32N/A
*-commutativeN/A
lift-log.f32N/A
lift-*.f32N/A
lift-PI.f3265.4
Applied rewrites65.4%
lift-/.f32N/A
lift-PI.f32N/A
lift-*.f32N/A
lift-log.f32N/A
*-commutativeN/A
associate-/r*N/A
lower-/.f32N/A
lower-/.f32N/A
lift-PI.f32N/A
lift-log.f3265.5
Applied rewrites65.5%
(FPCore (cosTheta alpha) :precision binary32 (/ -0.5 (* (log alpha) PI)))
float code(float cosTheta, float alpha) {
return -0.5f / (logf(alpha) * ((float) M_PI));
}
function code(cosTheta, alpha) return Float32(Float32(-0.5) / Float32(log(alpha) * Float32(pi))) end
function tmp = code(cosTheta, alpha) tmp = single(-0.5) / (log(alpha) * single(pi)); end
\begin{array}{l}
\\
\frac{-0.5}{\log \alpha \cdot \pi}
\end{array}
Initial program 98.5%
Taylor expanded in alpha around 0
frac-2negN/A
metadata-evalN/A
distribute-rgt-neg-inN/A
distribute-lft-neg-outN/A
log-recN/A
lower-/.f32N/A
associate-*r*N/A
log-recN/A
distribute-rgt-neg-outN/A
distribute-lft-neg-inN/A
distribute-rgt-neg-inN/A
lower-*.f32N/A
Applied rewrites66.8%
Taylor expanded in cosTheta around 0
lower-/.f32N/A
*-commutativeN/A
lift-log.f32N/A
lift-*.f32N/A
lift-PI.f3265.4
Applied rewrites65.4%
herbie shell --seed 2025130
(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)))))