
(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 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 (/ (/ (/ (- (* alpha alpha) 1.0) PI) (log (* alpha alpha))) (fma (* cosTheta cosTheta) (* (- 1.0 (pow alpha -2.0)) (* alpha alpha)) 1.0)))
float code(float cosTheta, float alpha) {
return ((((alpha * alpha) - 1.0f) / ((float) M_PI)) / logf((alpha * alpha))) / fmaf((cosTheta * cosTheta), ((1.0f - powf(alpha, -2.0f)) * (alpha * alpha)), 1.0f);
}
function code(cosTheta, alpha) return Float32(Float32(Float32(Float32(Float32(alpha * alpha) - Float32(1.0)) / Float32(pi)) / log(Float32(alpha * alpha))) / fma(Float32(cosTheta * cosTheta), Float32(Float32(Float32(1.0) - (alpha ^ Float32(-2.0))) * Float32(alpha * alpha)), Float32(1.0))) end
\begin{array}{l}
\\
\frac{\frac{\frac{\alpha \cdot \alpha - 1}{\pi}}{\log \left(\alpha \cdot \alpha\right)}}{\mathsf{fma}\left(cosTheta \cdot cosTheta, \left(1 - {\alpha}^{-2}\right) \cdot \left(\alpha \cdot \alpha\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-log.f32N/A
lift-*.f32N/A
lift-+.f32N/A
lift-*.f32N/A
lift-*.f32N/A
lift--.f32N/A
lift-*.f32N/A
Applied rewrites98.4%
Taylor expanded in alpha around inf
*-commutativeN/A
lower-*.f32N/A
lower--.f32N/A
pow-flipN/A
metadata-evalN/A
lower-pow.f32N/A
pow2N/A
lift-*.f3298.4
Applied rewrites98.4%
(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(Float32(Float32(t_0 / Float32(pi)) / 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{\frac{\frac{t\_0}{\pi}}{\log \left(\alpha \cdot \alpha\right)}}{\mathsf{fma}\left(cosTheta \cdot cosTheta, t\_0, 1\right)}
\end{array}
\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-log.f32N/A
lift-*.f32N/A
lift-+.f32N/A
lift-*.f32N/A
lift-*.f32N/A
lift--.f32N/A
lift-*.f32N/A
Applied rewrites98.4%
(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(Float32(t_0 / 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{\frac{t\_0}{\pi}}{\log \left(\alpha \cdot \alpha\right) \cdot \mathsf{fma}\left(cosTheta \cdot cosTheta, t\_0, 1\right)}
\end{array}
\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-log.f32N/A
lift-*.f32N/A
lift-+.f32N/A
lift-*.f32N/A
lift-*.f32N/A
lift--.f32N/A
lift-*.f32N/A
Applied rewrites98.4%
lift-/.f32N/A
lift-/.f32N/A
lift-PI.f32N/A
lift-/.f32N/A
lift--.f32N/A
lift-*.f32N/A
lift-*.f32N/A
lift-fma.f32N/A
lift--.f32N/A
lift-*.f32N/A
associate-/l/N/A
Applied rewrites98.4%
(FPCore (cosTheta alpha)
:precision binary32
(/
(- (* alpha alpha) 1.0)
(*
PI
(*
(log (* alpha alpha))
(fma (fma (* alpha alpha) cosTheta (- 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), cosTheta, -cosTheta), cosTheta, 1.0f)));
}
function code(cosTheta, alpha) return Float32(Float32(Float32(alpha * alpha) - Float32(1.0)) / Float32(Float32(pi) * Float32(log(Float32(alpha * alpha)) * fma(fma(Float32(alpha * alpha), cosTheta, Float32(-cosTheta)), cosTheta, 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(\mathsf{fma}\left(\alpha \cdot \alpha, cosTheta, -cosTheta\right), cosTheta, 1\right)\right)}
\end{array}
Initial program 98.5%
Taylor expanded in alpha around 0
+-commutativeN/A
lower-fma.f32N/A
pow2N/A
lift-*.f32N/A
mul-1-negN/A
lower-neg.f3298.5
Applied rewrites98.5%
lift-*.f32N/A
lift-PI.f32N/A
lift-*.f32N/A
associate-*l*N/A
lower-*.f32N/A
lift-PI.f32N/A
lower-*.f3298.5
lift-+.f32N/A
+-commutativeN/A
lift-*.f32N/A
lower-fma.f3298.5
Applied rewrites98.5%
(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(Float32(alpha * alpha) - Float32(1.0)) / Float32(pi)) / Float32(log(Float32(alpha * alpha)) * fma(Float32(-cosTheta), cosTheta, Float32(1.0)))) end
\begin{array}{l}
\\
\frac{\frac{\alpha \cdot \alpha - 1}{\pi}}{\log \left(\alpha \cdot \alpha\right) \cdot \mathsf{fma}\left(-cosTheta, cosTheta, 1\right)}
\end{array}
Initial program 98.5%
Taylor expanded in alpha around 0
+-commutativeN/A
lower-fma.f32N/A
pow2N/A
lift-*.f32N/A
mul-1-negN/A
lower-neg.f3298.5
Applied rewrites98.5%
lift-*.f32N/A
lift-PI.f32N/A
lift-*.f32N/A
associate-*l*N/A
lower-*.f32N/A
lift-PI.f32N/A
lower-*.f3298.5
lift-+.f32N/A
+-commutativeN/A
lift-*.f32N/A
lower-fma.f3298.5
Applied rewrites98.5%
Taylor expanded in alpha around 0
mul-1-negN/A
lift-neg.f3297.5
Applied rewrites97.5%
lift-/.f32N/A
lift-PI.f32N/A
lift-*.f32N/A
associate-/r*N/A
lift--.f32N/A
lift-*.f32N/A
lower-/.f32N/A
lift-*.f32N/A
lift--.f32N/A
lift-/.f32N/A
lift-PI.f3297.5
Applied rewrites97.5%
(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(pi) * Float32(log(Float32(alpha * alpha)) * fma(Float32(-cosTheta), cosTheta, 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, cosTheta, 1\right)\right)}
\end{array}
Initial program 98.5%
Taylor expanded in alpha around 0
+-commutativeN/A
lower-fma.f32N/A
pow2N/A
lift-*.f32N/A
mul-1-negN/A
lower-neg.f3298.5
Applied rewrites98.5%
lift-*.f32N/A
lift-PI.f32N/A
lift-*.f32N/A
associate-*l*N/A
lower-*.f32N/A
lift-PI.f32N/A
lower-*.f3298.5
lift-+.f32N/A
+-commutativeN/A
lift-*.f32N/A
lower-fma.f3298.5
Applied rewrites98.5%
Taylor expanded in alpha around 0
mul-1-negN/A
lift-neg.f3297.5
Applied rewrites97.5%
(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(Float32(alpha * alpha) - Float32(1.0)) / 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{\frac{\alpha \cdot \alpha - 1}{\pi}}{\log \left(\alpha \cdot \alpha\right)}
\end{array}
Initial program 98.5%
Taylor expanded in cosTheta around 0
associate-/r*N/A
lower-/.f32N/A
lower-/.f32N/A
pow2N/A
lift-*.f32N/A
lift--.f32N/A
lift-PI.f32N/A
lower-log.f32N/A
pow2N/A
lift-*.f3295.1
Applied rewrites95.1%
(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 98.5%
Taylor expanded in alpha around 0
+-commutativeN/A
lower-fma.f32N/A
pow2N/A
lift-*.f32N/A
mul-1-negN/A
lower-neg.f3298.5
Applied rewrites98.5%
lift-*.f32N/A
lift-PI.f32N/A
lift-*.f32N/A
associate-*l*N/A
lower-*.f32N/A
lift-PI.f32N/A
lower-*.f3298.5
lift-+.f32N/A
+-commutativeN/A
lift-*.f32N/A
lower-fma.f3298.5
Applied rewrites98.5%
Taylor expanded in cosTheta around 0
lower-log.f32N/A
pow2N/A
lift-*.f3295.2
Applied rewrites95.2%
(FPCore (cosTheta alpha) :precision binary32 (/ (* 0.5 (- (* alpha alpha) 1.0)) (* (log alpha) PI)))
float code(float cosTheta, float alpha) {
return (0.5f * ((alpha * alpha) - 1.0f)) / (logf(alpha) * ((float) M_PI));
}
function code(cosTheta, alpha) return Float32(Float32(Float32(0.5) * Float32(Float32(alpha * alpha) - Float32(1.0))) / Float32(log(alpha) * Float32(pi))) end
function tmp = code(cosTheta, alpha) tmp = (single(0.5) * ((alpha * alpha) - single(1.0))) / (log(alpha) * single(pi)); end
\begin{array}{l}
\\
\frac{0.5 \cdot \left(\alpha \cdot \alpha - 1\right)}{\log \alpha \cdot \pi}
\end{array}
Initial program 98.5%
Taylor expanded in cosTheta around 0
Applied rewrites95.2%
Taylor expanded in alpha around 0
Applied rewrites65.3%
lift-PI.f32N/A
lift-*.f32N/A
lift-log.f32N/A
log-pow-revN/A
lift-*.f32N/A
pow2N/A
pow-powN/A
log-pow-revN/A
associate-*r*N/A
*-commutativeN/A
lower-*.f32N/A
*-commutativeN/A
lower-*.f32N/A
lower-log.f32N/A
lift-PI.f3265.3
Applied rewrites65.3%
Taylor expanded in cosTheta around 0
Applied rewrites95.1%
(FPCore (cosTheta alpha) :precision binary32 (/ -1.0 (* (* PI (log (* alpha alpha))) 1.0)))
float code(float cosTheta, float alpha) {
return -1.0f / ((((float) M_PI) * logf((alpha * alpha))) * 1.0f);
}
function code(cosTheta, alpha) return Float32(Float32(-1.0) / Float32(Float32(Float32(pi) * log(Float32(alpha * alpha))) * Float32(1.0))) end
function tmp = code(cosTheta, alpha) tmp = single(-1.0) / ((single(pi) * log((alpha * alpha))) * single(1.0)); end
\begin{array}{l}
\\
\frac{-1}{\left(\pi \cdot \log \left(\alpha \cdot \alpha\right)\right) \cdot 1}
\end{array}
Initial program 98.5%
Taylor expanded in cosTheta around 0
Applied rewrites95.2%
Taylor expanded in alpha around 0
Applied rewrites65.3%
herbie shell --seed 2025107
(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)))))