
(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 9 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) (* (* 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(Float32(fma(alpha, alpha, Float32(-1.0)) * 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) \cdot cosTheta, cosTheta, 1\right)}
\end{array}
Initial program 98.6%
lift-*.f32N/A
lift--.f32N/A
lift-*.f32N/A
lift-*.f32N/A
+-commutativeN/A
lift-*.f32N/A
lower-fma.f3298.7
lift--.f32N/A
sub-negN/A
lift-*.f32N/A
lower-fma.f32N/A
metadata-eval98.7
Applied rewrites98.7%
Final simplification98.7%
(FPCore (cosTheta alpha) :precision binary32 (/ (fma 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 fmaf(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(fma(alpha, alpha, Float32(-1.0)) / Float32(Float32(Float32(pi) * log(Float32(alpha * alpha))) * fma(Float32(fma(alpha, alpha, Float32(-1.0)) * cosTheta), cosTheta, Float32(1.0)))) end
\begin{array}{l}
\\
\frac{\mathsf{fma}\left(\alpha, \alpha, -1\right)}{\left(\pi \cdot \log \left(\alpha \cdot \alpha\right)\right) \cdot \mathsf{fma}\left(\mathsf{fma}\left(\alpha, \alpha, -1\right) \cdot cosTheta, cosTheta, 1\right)}
\end{array}
Initial program 98.6%
lift-*.f32N/A
lift--.f32N/A
lift-*.f32N/A
lift-*.f32N/A
+-commutativeN/A
lift-*.f32N/A
lower-fma.f3298.7
lift--.f32N/A
sub-negN/A
lift-*.f32N/A
lower-fma.f32N/A
metadata-eval98.7
Applied rewrites98.7%
Taylor expanded in alpha around 0
sub-negN/A
unpow2N/A
metadata-evalN/A
lower-fma.f3298.6
Applied rewrites98.6%
(FPCore (cosTheta alpha) :precision binary32 (/ (+ (* alpha alpha) -1.0) (* (* PI (log (* alpha alpha))) (fma (- cosTheta) cosTheta 1.0))))
float code(float cosTheta, float alpha) {
return ((alpha * alpha) + -1.0f) / ((((float) M_PI) * logf((alpha * alpha))) * fmaf(-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(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(-cosTheta, cosTheta, 1\right)}
\end{array}
Initial program 98.6%
lift-*.f32N/A
lift--.f32N/A
lift-*.f32N/A
lift-*.f32N/A
+-commutativeN/A
lift-*.f32N/A
lower-fma.f3298.7
lift--.f32N/A
sub-negN/A
lift-*.f32N/A
lower-fma.f32N/A
metadata-eval98.7
Applied rewrites98.7%
Taylor expanded in alpha around 0
mul-1-negN/A
lower-neg.f3297.5
Applied rewrites97.5%
Final simplification97.5%
(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 98.6%
Taylor expanded in alpha around 0
mul-1-negN/A
unsub-negN/A
lower--.f32N/A
unpow2N/A
lower-*.f3297.5
Applied rewrites97.5%
Final simplification97.5%
(FPCore (cosTheta alpha) :precision binary32 (/ (fma alpha alpha -1.0) (* (* (- 1.0 (* cosTheta cosTheta)) (log alpha)) (* PI 2.0))))
float code(float cosTheta, float alpha) {
return fmaf(alpha, alpha, -1.0f) / (((1.0f - (cosTheta * cosTheta)) * logf(alpha)) * (((float) M_PI) * 2.0f));
}
function code(cosTheta, alpha) return Float32(fma(alpha, alpha, Float32(-1.0)) / Float32(Float32(Float32(Float32(1.0) - Float32(cosTheta * cosTheta)) * log(alpha)) * Float32(Float32(pi) * Float32(2.0)))) end
\begin{array}{l}
\\
\frac{\mathsf{fma}\left(\alpha, \alpha, -1\right)}{\left(\left(1 - cosTheta \cdot cosTheta\right) \cdot \log \alpha\right) \cdot \left(\pi \cdot 2\right)}
\end{array}
Initial program 98.6%
lift-*.f32N/A
lift--.f32N/A
lift-*.f32N/A
lift-*.f32N/A
+-commutativeN/A
lift-*.f32N/A
lower-fma.f3298.7
lift--.f32N/A
sub-negN/A
lift-*.f32N/A
lower-fma.f32N/A
metadata-eval98.7
Applied rewrites98.7%
Taylor expanded in alpha around 0
sub-negN/A
unpow2N/A
metadata-evalN/A
lower-fma.f3298.6
Applied rewrites98.6%
Taylor expanded in alpha around 0
associate-*r*N/A
*-commutativeN/A
lower-*.f32N/A
lower-*.f32N/A
lower-log.f32N/A
mul-1-negN/A
unsub-negN/A
lower--.f32N/A
unpow2N/A
lower-*.f32N/A
lower-*.f32N/A
lower-PI.f3297.5
Applied rewrites97.5%
Final simplification97.5%
(FPCore (cosTheta alpha) :precision binary32 (/ (fma alpha alpha -1.0) (* (* PI (log alpha)) (fma (* cosTheta cosTheta) -2.0 2.0))))
float code(float cosTheta, float alpha) {
return fmaf(alpha, alpha, -1.0f) / ((((float) M_PI) * logf(alpha)) * fmaf((cosTheta * cosTheta), -2.0f, 2.0f));
}
function code(cosTheta, alpha) return Float32(fma(alpha, alpha, Float32(-1.0)) / Float32(Float32(Float32(pi) * log(alpha)) * fma(Float32(cosTheta * cosTheta), Float32(-2.0), Float32(2.0)))) end
\begin{array}{l}
\\
\frac{\mathsf{fma}\left(\alpha, \alpha, -1\right)}{\left(\pi \cdot \log \alpha\right) \cdot \mathsf{fma}\left(cosTheta \cdot cosTheta, -2, 2\right)}
\end{array}
Initial program 98.6%
lift-*.f32N/A
sub-negN/A
lift-*.f32N/A
lower-fma.f32N/A
metadata-eval98.6
Applied rewrites98.6%
Taylor expanded in alpha around 0
*-commutativeN/A
associate-*r*N/A
associate-*l*N/A
*-commutativeN/A
lower-*.f32N/A
lower-*.f32N/A
lower-PI.f32N/A
lower-log.f32N/A
+-commutativeN/A
distribute-rgt-inN/A
*-commutativeN/A
associate-*l*N/A
metadata-evalN/A
metadata-evalN/A
lower-fma.f32N/A
unpow2N/A
lower-*.f3297.4
Applied rewrites97.4%
(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--.f32N/A
lift-*.f32N/A
lift-*.f32N/A
+-commutativeN/A
lift-*.f32N/A
lower-fma.f3298.7
lift--.f32N/A
sub-negN/A
lift-*.f32N/A
lower-fma.f32N/A
metadata-eval98.7
Applied rewrites98.7%
Taylor expanded in cosTheta around 0
lower-*.f32N/A
lower-PI.f32N/A
lower-log.f32N/A
unpow2N/A
lower-*.f3294.7
Applied rewrites94.7%
Final simplification94.7%
(FPCore (cosTheta alpha) :precision binary32 (/ (fma alpha alpha -1.0) (* PI (log (* alpha alpha)))))
float code(float cosTheta, float alpha) {
return fmaf(alpha, alpha, -1.0f) / (((float) M_PI) * logf((alpha * alpha)));
}
function code(cosTheta, alpha) return Float32(fma(alpha, alpha, Float32(-1.0)) / Float32(Float32(pi) * log(Float32(alpha * alpha)))) end
\begin{array}{l}
\\
\frac{\mathsf{fma}\left(\alpha, \alpha, -1\right)}{\pi \cdot \log \left(\alpha \cdot \alpha\right)}
\end{array}
Initial program 98.6%
Taylor expanded in cosTheta around 0
lower-/.f32N/A
sub-negN/A
unpow2N/A
metadata-evalN/A
lower-fma.f32N/A
lower-*.f32N/A
lower-PI.f32N/A
lower-log.f32N/A
unpow2N/A
lower-*.f3294.6
Applied rewrites94.6%
(FPCore (cosTheta alpha) :precision binary32 (/ -1.0 (* (/ 0.0 0.0) PI)))
float code(float cosTheta, float alpha) {
return -1.0f / ((0.0f / 0.0f) * ((float) M_PI));
}
function code(cosTheta, alpha) return Float32(Float32(-1.0) / Float32(Float32(Float32(0.0) / Float32(0.0)) * Float32(pi))) end
function tmp = code(cosTheta, alpha) tmp = single(-1.0) / ((single(0.0) / single(0.0)) * single(pi)); end
\begin{array}{l}
\\
\frac{-1}{\frac{0}{0} \cdot \pi}
\end{array}
Initial program 98.6%
lift-*.f32N/A
lift--.f32N/A
lift-PI.f32N/A
lift-*.f32N/A
lift-log.f32N/A
lift-*.f32N/A
lift-*.f32N/A
lift--.f32N/A
lift-*.f32N/A
lift-*.f32N/A
lift-+.f32N/A
lift-*.f32N/A
remove-double-negN/A
Applied rewrites-0.0%
Taylor expanded in alpha around 0
mul-1-negN/A
lower-neg.f32-0.0
Applied rewrites-0.0%
Taylor expanded in alpha around 0
Applied rewrites-0.0%
Taylor expanded in cosTheta around 0
lower-PI.f32-0.0
Applied rewrites-0.0%
herbie shell --seed 2024212
(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)))))