
(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 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)
(*
2.0
(+
(* (log alpha) (* PI (- 1.0 (* cosTheta cosTheta))))
(* (* cosTheta cosTheta) (* (* alpha alpha) (* (log alpha) PI)))))))
float code(float cosTheta, float alpha) {
return ((alpha * alpha) + -1.0f) / (2.0f * ((logf(alpha) * (((float) M_PI) * (1.0f - (cosTheta * cosTheta)))) + ((cosTheta * cosTheta) * ((alpha * alpha) * (logf(alpha) * ((float) M_PI))))));
}
function code(cosTheta, alpha) return Float32(Float32(Float32(alpha * alpha) + Float32(-1.0)) / Float32(Float32(2.0) * Float32(Float32(log(alpha) * Float32(Float32(pi) * Float32(Float32(1.0) - Float32(cosTheta * cosTheta)))) + Float32(Float32(cosTheta * cosTheta) * Float32(Float32(alpha * alpha) * Float32(log(alpha) * Float32(pi))))))) end
function tmp = code(cosTheta, alpha) tmp = ((alpha * alpha) + single(-1.0)) / (single(2.0) * ((log(alpha) * (single(pi) * (single(1.0) - (cosTheta * cosTheta)))) + ((cosTheta * cosTheta) * ((alpha * alpha) * (log(alpha) * single(pi)))))); end
\begin{array}{l}
\\
\frac{\alpha \cdot \alpha + -1}{2 \cdot \left(\log \alpha \cdot \left(\pi \cdot \left(1 - cosTheta \cdot cosTheta\right)\right) + \left(cosTheta \cdot cosTheta\right) \cdot \left(\left(\alpha \cdot \alpha\right) \cdot \left(\log \alpha \cdot \pi\right)\right)\right)}
\end{array}
Initial program 98.4%
Taylor expanded in alpha around 0
distribute-lft-outN/A
*-lowering-*.f32N/A
+-lowering-+.f32N/A
Simplified98.4%
Final simplification98.4%
(FPCore (cosTheta alpha)
:precision binary32
(let* ((t_0 (+ (* alpha alpha) -1.0)))
(/
t_0
(* (* PI (log (* alpha alpha))) (+ 1.0 (* cosTheta (* t_0 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 + (cosTheta * (t_0 * 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(cosTheta * Float32(t_0 * 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) + (cosTheta * (t_0 * 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 + cosTheta \cdot \left(t\_0 \cdot cosTheta\right)\right)}
\end{array}
\end{array}
Initial program 98.4%
Final simplification98.4%
(FPCore (cosTheta alpha) :precision binary32 (/ (+ (* alpha alpha) -1.0) (* (- 1.0 (* cosTheta cosTheta)) (* PI (log (* alpha alpha))))))
float code(float cosTheta, float alpha) {
return ((alpha * alpha) + -1.0f) / ((1.0f - (cosTheta * cosTheta)) * (((float) M_PI) * logf((alpha * alpha))));
}
function code(cosTheta, alpha) return Float32(Float32(Float32(alpha * alpha) + Float32(-1.0)) / Float32(Float32(Float32(1.0) - Float32(cosTheta * cosTheta)) * Float32(Float32(pi) * log(Float32(alpha * alpha))))) end
function tmp = code(cosTheta, alpha) tmp = ((alpha * alpha) + single(-1.0)) / ((single(1.0) - (cosTheta * cosTheta)) * (single(pi) * log((alpha * alpha)))); end
\begin{array}{l}
\\
\frac{\alpha \cdot \alpha + -1}{\left(1 - cosTheta \cdot cosTheta\right) \cdot \left(\pi \cdot \log \left(\alpha \cdot \alpha\right)\right)}
\end{array}
Initial program 98.4%
Taylor expanded in alpha around 0
mul-1-negN/A
neg-lowering-neg.f3297.1%
Simplified97.1%
Final simplification97.1%
(FPCore (cosTheta alpha) :precision binary32 (/ (+ (* alpha alpha) -1.0) (* (- 1.0 (* cosTheta cosTheta)) (* PI (* 2.0 (log alpha))))))
float code(float cosTheta, float alpha) {
return ((alpha * alpha) + -1.0f) / ((1.0f - (cosTheta * cosTheta)) * (((float) M_PI) * (2.0f * logf(alpha))));
}
function code(cosTheta, alpha) return Float32(Float32(Float32(alpha * alpha) + Float32(-1.0)) / Float32(Float32(Float32(1.0) - Float32(cosTheta * cosTheta)) * Float32(Float32(pi) * Float32(Float32(2.0) * log(alpha))))) end
function tmp = code(cosTheta, alpha) tmp = ((alpha * alpha) + single(-1.0)) / ((single(1.0) - (cosTheta * cosTheta)) * (single(pi) * (single(2.0) * log(alpha)))); end
\begin{array}{l}
\\
\frac{\alpha \cdot \alpha + -1}{\left(1 - cosTheta \cdot cosTheta\right) \cdot \left(\pi \cdot \left(2 \cdot \log \alpha\right)\right)}
\end{array}
Initial program 98.4%
Taylor expanded in alpha around 0
distribute-lft-outN/A
*-lowering-*.f32N/A
+-lowering-+.f32N/A
Simplified98.4%
Taylor expanded in alpha around 0
associate-*r*N/A
sub-negN/A
mul-1-negN/A
associate-*r*N/A
associate-*r*N/A
*-lowering-*.f32N/A
*-commutativeN/A
associate-*r*N/A
*-lowering-*.f32N/A
*-commutativeN/A
*-lowering-*.f32N/A
log-lowering-log.f32N/A
PI-lowering-PI.f32N/A
mul-1-negN/A
sub-negN/A
--lowering--.f32N/A
unpow2N/A
*-lowering-*.f3297.1%
Simplified97.1%
Final simplification97.1%
(FPCore (cosTheta alpha) :precision binary32 (/ (+ (* alpha alpha) -1.0) (* (* (log alpha) (- 1.0 (* cosTheta cosTheta))) (* 2.0 PI))))
float code(float cosTheta, float alpha) {
return ((alpha * alpha) + -1.0f) / ((logf(alpha) * (1.0f - (cosTheta * cosTheta))) * (2.0f * ((float) M_PI)));
}
function code(cosTheta, alpha) return Float32(Float32(Float32(alpha * alpha) + Float32(-1.0)) / Float32(Float32(log(alpha) * Float32(Float32(1.0) - Float32(cosTheta * cosTheta))) * Float32(Float32(2.0) * Float32(pi)))) end
function tmp = code(cosTheta, alpha) tmp = ((alpha * alpha) + single(-1.0)) / ((log(alpha) * (single(1.0) - (cosTheta * cosTheta))) * (single(2.0) * single(pi))); end
\begin{array}{l}
\\
\frac{\alpha \cdot \alpha + -1}{\left(\log \alpha \cdot \left(1 - cosTheta \cdot cosTheta\right)\right) \cdot \left(2 \cdot \pi\right)}
\end{array}
Initial program 98.4%
Taylor expanded in alpha around 0
associate-*r*N/A
*-commutativeN/A
*-lowering-*.f32N/A
*-lowering-*.f32N/A
log-lowering-log.f32N/A
mul-1-negN/A
unsub-negN/A
--lowering--.f32N/A
unpow2N/A
*-lowering-*.f32N/A
*-commutativeN/A
*-lowering-*.f32N/A
PI-lowering-PI.f3297.1%
Simplified97.1%
Final simplification97.1%
(FPCore (cosTheta alpha) :precision binary32 (* 0.5 (* (+ 1.0 (* cosTheta cosTheta)) (/ (+ (* alpha alpha) -1.0) (* (log alpha) PI)))))
float code(float cosTheta, float alpha) {
return 0.5f * ((1.0f + (cosTheta * cosTheta)) * (((alpha * alpha) + -1.0f) / (logf(alpha) * ((float) M_PI))));
}
function code(cosTheta, alpha) return Float32(Float32(0.5) * Float32(Float32(Float32(1.0) + Float32(cosTheta * cosTheta)) * Float32(Float32(Float32(alpha * alpha) + Float32(-1.0)) / Float32(log(alpha) * Float32(pi))))) end
function tmp = code(cosTheta, alpha) tmp = single(0.5) * ((single(1.0) + (cosTheta * cosTheta)) * (((alpha * alpha) + single(-1.0)) / (log(alpha) * single(pi)))); end
\begin{array}{l}
\\
0.5 \cdot \left(\left(1 + cosTheta \cdot cosTheta\right) \cdot \frac{\alpha \cdot \alpha + -1}{\log \alpha \cdot \pi}\right)
\end{array}
Initial program 98.4%
Taylor expanded in alpha around 0
associate-*r*N/A
*-commutativeN/A
*-lowering-*.f32N/A
*-lowering-*.f32N/A
log-lowering-log.f32N/A
mul-1-negN/A
unsub-negN/A
--lowering--.f32N/A
unpow2N/A
*-lowering-*.f32N/A
*-commutativeN/A
*-lowering-*.f32N/A
PI-lowering-PI.f3297.1%
Simplified97.1%
Taylor expanded in cosTheta around 0
distribute-lft-outN/A
*-lowering-*.f32N/A
associate-/l*N/A
distribute-lft1-inN/A
*-lowering-*.f32N/A
+-lowering-+.f32N/A
unpow2N/A
*-lowering-*.f32N/A
/-lowering-/.f32N/A
sub-negN/A
metadata-evalN/A
+-commutativeN/A
+-lowering-+.f32N/A
unpow2N/A
*-lowering-*.f32N/A
*-lowering-*.f32N/A
PI-lowering-PI.f32N/A
log-lowering-log.f3295.6%
Simplified95.6%
Final simplification95.6%
(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 98.4%
Taylor expanded in cosTheta around 0
*-lowering-*.f32N/A
PI-lowering-PI.f32N/A
log-lowering-log.f32N/A
unpow2N/A
*-lowering-*.f3293.7%
Simplified93.7%
Final simplification93.7%
(FPCore (cosTheta alpha) :precision binary32 (/ -0.5 (* (- 1.0 (* cosTheta cosTheta)) (* (log alpha) PI))))
float code(float cosTheta, float alpha) {
return -0.5f / ((1.0f - (cosTheta * cosTheta)) * (logf(alpha) * ((float) M_PI)));
}
function code(cosTheta, alpha) return Float32(Float32(-0.5) / Float32(Float32(Float32(1.0) - Float32(cosTheta * cosTheta)) * Float32(log(alpha) * Float32(pi)))) end
function tmp = code(cosTheta, alpha) tmp = single(-0.5) / ((single(1.0) - (cosTheta * cosTheta)) * (log(alpha) * single(pi))); end
\begin{array}{l}
\\
\frac{-0.5}{\left(1 - cosTheta \cdot cosTheta\right) \cdot \left(\log \alpha \cdot \pi\right)}
\end{array}
Initial program 98.4%
Taylor expanded in alpha around 0
distribute-lft-outN/A
*-lowering-*.f32N/A
+-lowering-+.f32N/A
Simplified98.4%
Taylor expanded in alpha around 0
/-lowering-/.f32N/A
associate-*r*N/A
sub-negN/A
mul-1-negN/A
*-lowering-*.f32N/A
*-lowering-*.f32N/A
PI-lowering-PI.f32N/A
log-lowering-log.f32N/A
mul-1-negN/A
sub-negN/A
--lowering--.f32N/A
unpow2N/A
*-lowering-*.f3267.8%
Simplified67.8%
Final simplification67.8%
(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(Float32(-1.0) / 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{\frac{-1}{\pi}}{\log \left(\alpha \cdot \alpha\right)}
\end{array}
Initial program 98.4%
associate-*l*N/A
associate-/r*N/A
/-lowering-/.f32N/A
/-lowering-/.f32N/A
sub-negN/A
+-lowering-+.f32N/A
*-lowering-*.f32N/A
metadata-evalN/A
PI-lowering-PI.f32N/A
*-lowering-*.f32N/A
log-lowering-log.f32N/A
*-lowering-*.f32N/A
+-lowering-+.f32N/A
associate-*l*N/A
*-lowering-*.f32N/A
Simplified98.3%
Taylor expanded in alpha around 0
/-lowering-/.f32N/A
PI-lowering-PI.f3267.9%
Simplified67.9%
Taylor expanded in cosTheta around 0
associate-/r*N/A
metadata-evalN/A
distribute-neg-fracN/A
/-lowering-/.f32N/A
distribute-neg-fracN/A
metadata-evalN/A
/-lowering-/.f32N/A
PI-lowering-PI.f32N/A
log-lowering-log.f32N/A
unpow2N/A
*-lowering-*.f3265.6%
Simplified65.6%
(FPCore (cosTheta alpha) :precision binary32 (/ (/ -1.0 PI) (/ 0.0 0.0)))
float code(float cosTheta, float alpha) {
return (-1.0f / ((float) M_PI)) / (0.0f / 0.0f);
}
function code(cosTheta, alpha) return Float32(Float32(Float32(-1.0) / Float32(pi)) / Float32(Float32(0.0) / Float32(0.0))) end
function tmp = code(cosTheta, alpha) tmp = (single(-1.0) / single(pi)) / (single(0.0) / single(0.0)); end
\begin{array}{l}
\\
\frac{\frac{-1}{\pi}}{\frac{0}{0}}
\end{array}
Initial program 98.4%
difference-of-sqr-1N/A
difference-of-sqr--1N/A
associate-/r*N/A
associate-/r*N/A
associate-/l/N/A
associate-/r*N/A
/-lowering-/.f32N/A
Applied egg-rr-0.0%
Taylor expanded in cosTheta around 0
/-lowering-/.f32N/A
sub-negN/A
metadata-evalN/A
+-lowering-+.f32N/A
unpow2N/A
*-lowering-*.f32N/A
PI-lowering-PI.f32-0.0%
Simplified-0.0%
Taylor expanded in alpha around 0
/-lowering-/.f32N/A
PI-lowering-PI.f32-0.0%
Simplified-0.0%
herbie shell --seed 2024155
(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)))))