
(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 11 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) (* (+ (* (* (* cosTheta (- alpha 1.0)) cosTheta) (+ 1.0 alpha)) 1.0) (* (log (* alpha alpha)) PI))))
float code(float cosTheta, float alpha) {
return ((alpha * alpha) - 1.0f) / (((((cosTheta * (alpha - 1.0f)) * cosTheta) * (1.0f + alpha)) + 1.0f) * (logf((alpha * alpha)) * ((float) M_PI)));
}
function code(cosTheta, alpha) return Float32(Float32(Float32(alpha * alpha) - Float32(1.0)) / Float32(Float32(Float32(Float32(Float32(cosTheta * Float32(alpha - Float32(1.0))) * cosTheta) * Float32(Float32(1.0) + alpha)) + Float32(1.0)) * Float32(log(Float32(alpha * alpha)) * Float32(pi)))) end
function tmp = code(cosTheta, alpha) tmp = ((alpha * alpha) - single(1.0)) / (((((cosTheta * (alpha - single(1.0))) * cosTheta) * (single(1.0) + alpha)) + single(1.0)) * (log((alpha * alpha)) * single(pi))); end
\begin{array}{l}
\\
\frac{\alpha \cdot \alpha - 1}{\left(\left(\left(cosTheta \cdot \left(\alpha - 1\right)\right) \cdot cosTheta\right) \cdot \left(1 + \alpha\right) + 1\right) \cdot \left(\log \left(\alpha \cdot \alpha\right) \cdot \pi\right)}
\end{array}
Initial program 98.6%
lift-*.f32N/A
lift-*.f32N/A
associate-*l*N/A
lift--.f32N/A
lift-*.f32N/A
difference-of-sqr-1N/A
associate-*l*N/A
lower-*.f32N/A
+-commutativeN/A
lower-+.f32N/A
associate-*r*N/A
lower-*.f32N/A
lower-*.f32N/A
lower--.f3298.6
Applied rewrites98.6%
Final simplification98.6%
(FPCore (cosTheta alpha) :precision binary32 (/ (- (* alpha alpha) 1.0) (* (fma (* (fma alpha alpha -1.0) cosTheta) cosTheta 1.0) (* (log (* alpha alpha)) PI))))
float code(float cosTheta, float alpha) {
return ((alpha * alpha) - 1.0f) / (fmaf((fmaf(alpha, alpha, -1.0f) * cosTheta), cosTheta, 1.0f) * (logf((alpha * alpha)) * ((float) M_PI)));
}
function code(cosTheta, alpha) return Float32(Float32(Float32(alpha * alpha) - Float32(1.0)) / Float32(fma(Float32(fma(alpha, alpha, Float32(-1.0)) * cosTheta), cosTheta, Float32(1.0)) * Float32(log(Float32(alpha * alpha)) * Float32(pi)))) end
\begin{array}{l}
\\
\frac{\alpha \cdot \alpha - 1}{\mathsf{fma}\left(\mathsf{fma}\left(\alpha, \alpha, -1\right) \cdot cosTheta, cosTheta, 1\right) \cdot \left(\log \left(\alpha \cdot \alpha\right) \cdot \pi\right)}
\end{array}
Initial program 98.6%
lift-+.f32N/A
+-commutativeN/A
lift-*.f32N/A
lower-fma.f3298.6
lift-*.f32N/A
*-commutativeN/A
lower-*.f3298.6
lift--.f32N/A
sub-negN/A
lift-*.f32N/A
lower-fma.f32N/A
metadata-eval98.6
Applied rewrites98.6%
Final simplification98.6%
(FPCore (cosTheta alpha) :precision binary32 (/ (fma alpha alpha -1.0) (* (fma (* (fma alpha alpha -1.0) cosTheta) cosTheta 1.0) (* (log (* alpha alpha)) PI))))
float code(float cosTheta, float alpha) {
return fmaf(alpha, alpha, -1.0f) / (fmaf((fmaf(alpha, alpha, -1.0f) * cosTheta), cosTheta, 1.0f) * (logf((alpha * alpha)) * ((float) M_PI)));
}
function code(cosTheta, alpha) return Float32(fma(alpha, alpha, Float32(-1.0)) / Float32(fma(Float32(fma(alpha, alpha, Float32(-1.0)) * cosTheta), cosTheta, Float32(1.0)) * Float32(log(Float32(alpha * alpha)) * Float32(pi)))) end
\begin{array}{l}
\\
\frac{\mathsf{fma}\left(\alpha, \alpha, -1\right)}{\mathsf{fma}\left(\mathsf{fma}\left(\alpha, \alpha, -1\right) \cdot cosTheta, cosTheta, 1\right) \cdot \left(\log \left(\alpha \cdot \alpha\right) \cdot \pi\right)}
\end{array}
Initial program 98.6%
lift-+.f32N/A
+-commutativeN/A
lift-*.f32N/A
lower-fma.f3298.6
lift-*.f32N/A
*-commutativeN/A
lower-*.f3298.6
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
sub-negN/A
unpow2N/A
metadata-evalN/A
lower-fma.f3298.5
Applied rewrites98.5%
Final simplification98.5%
(FPCore (cosTheta alpha) :precision binary32 (/ (- (* alpha alpha) 1.0) (* (fma (- cosTheta) cosTheta 1.0) (* (log (* alpha alpha)) PI))))
float code(float cosTheta, float alpha) {
return ((alpha * alpha) - 1.0f) / (fmaf(-cosTheta, cosTheta, 1.0f) * (logf((alpha * alpha)) * ((float) M_PI)));
}
function code(cosTheta, alpha) return Float32(Float32(Float32(alpha * alpha) - Float32(1.0)) / Float32(fma(Float32(-cosTheta), cosTheta, Float32(1.0)) * Float32(log(Float32(alpha * alpha)) * Float32(pi)))) end
\begin{array}{l}
\\
\frac{\alpha \cdot \alpha - 1}{\mathsf{fma}\left(-cosTheta, cosTheta, 1\right) \cdot \left(\log \left(\alpha \cdot \alpha\right) \cdot \pi\right)}
\end{array}
Initial program 98.6%
lift-+.f32N/A
+-commutativeN/A
lift-*.f32N/A
lower-fma.f3298.6
lift-*.f32N/A
*-commutativeN/A
lower-*.f3298.6
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
mul-1-negN/A
lower-neg.f3296.6
Applied rewrites96.6%
Final simplification96.6%
(FPCore (cosTheta alpha) :precision binary32 (/ (- (* alpha alpha) 1.0) (* (- 1.0 (* cosTheta cosTheta)) (* (log (* alpha alpha)) PI))))
float code(float cosTheta, float alpha) {
return ((alpha * alpha) - 1.0f) / ((1.0f - (cosTheta * cosTheta)) * (logf((alpha * alpha)) * ((float) M_PI)));
}
function code(cosTheta, alpha) return Float32(Float32(Float32(alpha * alpha) - Float32(1.0)) / Float32(Float32(Float32(1.0) - Float32(cosTheta * cosTheta)) * Float32(log(Float32(alpha * alpha)) * Float32(pi)))) end
function tmp = code(cosTheta, alpha) tmp = ((alpha * alpha) - single(1.0)) / ((single(1.0) - (cosTheta * cosTheta)) * (log((alpha * alpha)) * single(pi))); end
\begin{array}{l}
\\
\frac{\alpha \cdot \alpha - 1}{\left(1 - cosTheta \cdot cosTheta\right) \cdot \left(\log \left(\alpha \cdot \alpha\right) \cdot \pi\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-*.f3296.6
Applied rewrites96.6%
Final simplification96.6%
(FPCore (cosTheta alpha) :precision binary32 (/ (- (* alpha alpha) 1.0) (* (fma -2.0 (* cosTheta cosTheta) 2.0) (* (log alpha) PI))))
float code(float cosTheta, float alpha) {
return ((alpha * alpha) - 1.0f) / (fmaf(-2.0f, (cosTheta * cosTheta), 2.0f) * (logf(alpha) * ((float) M_PI)));
}
function code(cosTheta, alpha) return Float32(Float32(Float32(alpha * alpha) - Float32(1.0)) / Float32(fma(Float32(-2.0), Float32(cosTheta * cosTheta), Float32(2.0)) * Float32(log(alpha) * Float32(pi)))) end
\begin{array}{l}
\\
\frac{\alpha \cdot \alpha - 1}{\mathsf{fma}\left(-2, cosTheta \cdot cosTheta, 2\right) \cdot \left(\log \alpha \cdot \pi\right)}
\end{array}
Initial program 98.6%
lift-+.f32N/A
+-commutativeN/A
lift-*.f32N/A
lower-fma.f3298.6
lift-*.f32N/A
*-commutativeN/A
lower-*.f3298.6
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
*-commutativeN/A
lower-*.f32N/A
lower-log.f32N/A
lower-PI.f32N/A
+-commutativeN/A
distribute-lft-inN/A
associate-*r*N/A
metadata-evalN/A
metadata-evalN/A
lower-fma.f32N/A
unpow2N/A
lower-*.f3296.5
Applied rewrites96.5%
Final simplification96.5%
(FPCore (cosTheta alpha) :precision binary32 (/ (fma alpha alpha -1.0) (* (fma (- cosTheta) cosTheta 1.0) (* (log (* alpha alpha)) PI))))
float code(float cosTheta, float alpha) {
return fmaf(alpha, alpha, -1.0f) / (fmaf(-cosTheta, cosTheta, 1.0f) * (logf((alpha * alpha)) * ((float) M_PI)));
}
function code(cosTheta, alpha) return Float32(fma(alpha, alpha, Float32(-1.0)) / Float32(fma(Float32(-cosTheta), cosTheta, Float32(1.0)) * Float32(log(Float32(alpha * alpha)) * Float32(pi)))) end
\begin{array}{l}
\\
\frac{\mathsf{fma}\left(\alpha, \alpha, -1\right)}{\mathsf{fma}\left(-cosTheta, cosTheta, 1\right) \cdot \left(\log \left(\alpha \cdot \alpha\right) \cdot \pi\right)}
\end{array}
Initial program 98.6%
lift-+.f32N/A
+-commutativeN/A
lift-*.f32N/A
lower-fma.f3298.6
lift-*.f32N/A
*-commutativeN/A
lower-*.f3298.6
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
mul-1-negN/A
lower-neg.f3296.6
Applied rewrites96.6%
Taylor expanded in alpha around 0
sub-negN/A
unpow2N/A
metadata-evalN/A
lower-fma.f3296.5
Applied rewrites96.5%
Final simplification96.5%
(FPCore (cosTheta alpha) :precision binary32 (/ (* 0.5 (fma alpha alpha -1.0)) (* (log alpha) PI)))
float code(float cosTheta, float alpha) {
return (0.5f * fmaf(alpha, alpha, -1.0f)) / (logf(alpha) * ((float) M_PI));
}
function code(cosTheta, alpha) return Float32(Float32(Float32(0.5) * fma(alpha, alpha, Float32(-1.0))) / Float32(log(alpha) * Float32(pi))) end
\begin{array}{l}
\\
\frac{0.5 \cdot \mathsf{fma}\left(\alpha, \alpha, -1\right)}{\log \alpha \cdot \pi}
\end{array}
Initial program 98.6%
lift-*.f32N/A
lift-log.f32N/A
lift-*.f32N/A
log-prodN/A
distribute-rgt-inN/A
distribute-lft-outN/A
lower-*.f32N/A
lower-log.f32N/A
lower-+.f3298.6
Applied rewrites98.6%
Taylor expanded in cosTheta around 0
associate-*r/N/A
lower-/.f32N/A
lower-*.f32N/A
sub-negN/A
unpow2N/A
metadata-evalN/A
lower-fma.f32N/A
*-commutativeN/A
lower-*.f32N/A
lower-log.f32N/A
lower-PI.f3293.1
Applied rewrites93.1%
(FPCore (cosTheta alpha) :precision binary32 (/ (fma alpha alpha -1.0) (* (log (* alpha alpha)) PI)))
float code(float cosTheta, float alpha) {
return fmaf(alpha, alpha, -1.0f) / (logf((alpha * alpha)) * ((float) M_PI));
}
function code(cosTheta, alpha) return Float32(fma(alpha, alpha, Float32(-1.0)) / Float32(log(Float32(alpha * alpha)) * Float32(pi))) end
\begin{array}{l}
\\
\frac{\mathsf{fma}\left(\alpha, \alpha, -1\right)}{\log \left(\alpha \cdot \alpha\right) \cdot \pi}
\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
*-commutativeN/A
lower-*.f32N/A
lower-log.f32N/A
unpow2N/A
lower-*.f32N/A
lower-PI.f3293.0
Applied rewrites93.0%
(FPCore (cosTheta alpha) :precision binary32 (/ -1.0 (* 2.0 (* (log alpha) PI))))
float code(float cosTheta, float alpha) {
return -1.0f / (2.0f * (logf(alpha) * ((float) M_PI)));
}
function code(cosTheta, alpha) return Float32(Float32(-1.0) / Float32(Float32(2.0) * Float32(log(alpha) * Float32(pi)))) end
function tmp = code(cosTheta, alpha) tmp = single(-1.0) / (single(2.0) * (log(alpha) * single(pi))); end
\begin{array}{l}
\\
\frac{-1}{2 \cdot \left(\log \alpha \cdot \pi\right)}
\end{array}
Initial program 98.6%
lift-*.f32N/A
lift-log.f32N/A
lift-*.f32N/A
log-prodN/A
distribute-rgt-inN/A
distribute-lft-outN/A
lower-*.f32N/A
lower-log.f32N/A
lower-+.f3298.6
Applied rewrites98.6%
Taylor expanded in alpha around 0
Applied rewrites65.3%
Taylor expanded in cosTheta around 0
*-commutativeN/A
lower-*.f32N/A
*-commutativeN/A
lower-*.f32N/A
lower-log.f32N/A
lower-PI.f3263.6
Applied rewrites63.6%
Final simplification63.6%
(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
sub-negN/A
lift-*.f32N/A
lower-fma.f32N/A
metadata-eval98.5
lift-*.f32N/A
lift-*.f32N/A
associate-*l*N/A
*-commutativeN/A
associate-*r*N/A
lower-*.f32N/A
Applied rewrites-0.0%
Taylor expanded in cosTheta around 0
lower-PI.f32-0.0
Applied rewrites-0.0%
Taylor expanded in alpha around 0
Applied rewrites-0.0%
Final simplification-0.0%
herbie shell --seed 2024235
(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)))))