
(FPCore (cosTheta alpha)
:precision binary32
:pre (and (and (<= 0.0 cosTheta) (<= cosTheta 1.0))
(and (<= 0.0001 alpha) (<= alpha 1.0)))
(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}
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}
Herbie found 8 alternatives:
| Alternative | Accuracy | Speedup |
|---|
(FPCore (cosTheta alpha)
:precision binary32
:pre (and (and (<= 0.0 cosTheta) (<= cosTheta 1.0))
(and (<= 0.0001 alpha) (<= alpha 1.0)))
(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}
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}
(FPCore (cosTheta alpha)
:precision binary32
:pre (and (and (<= 0.0 cosTheta) (<= cosTheta 1.0))
(and (<= 0.0001 alpha) (<= alpha 1.0)))
(let* ((t_0 (- (* alpha alpha) 1.0)))
(/
t_0
(*
(log (pow (* alpha alpha) PI))
(+ 1.0 (* (* t_0 cosTheta) cosTheta))))))float code(float cosTheta, float alpha) {
float t_0 = (alpha * alpha) - 1.0f;
return t_0 / (logf(powf((alpha * alpha), ((float) M_PI))) * (1.0f + ((t_0 * cosTheta) * cosTheta)));
}
function code(cosTheta, alpha) t_0 = Float32(Float32(alpha * alpha) - Float32(1.0)) return Float32(t_0 / Float32(log((Float32(alpha * alpha) ^ Float32(pi))) * 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 / (log(((alpha * alpha) ^ single(pi))) * (single(1.0) + ((t_0 * cosTheta) * cosTheta))); end
\begin{array}{l}
t_0 := \alpha \cdot \alpha - 1\\
\frac{t\_0}{\log \left({\left(\alpha \cdot \alpha\right)}^{\pi}\right) \cdot \left(1 + \left(t\_0 \cdot cosTheta\right) \cdot cosTheta\right)}
\end{array}
Initial program 98.5%
Applied rewrites98.6%
(FPCore (cosTheta alpha)
:precision binary32
:pre (and (and (<= 0.0 cosTheta) (<= cosTheta 1.0))
(and (<= 0.0001 alpha) (<= alpha 1.0)))
(let* ((t_0 (log (* alpha alpha))))
(/
(- (* alpha alpha) 1.0)
(fma
PI
t_0
(* (* (* (* (fma alpha alpha -1.0) cosTheta) cosTheta) t_0) PI)))))float code(float cosTheta, float alpha) {
float t_0 = logf((alpha * alpha));
return ((alpha * alpha) - 1.0f) / fmaf(((float) M_PI), t_0, ((((fmaf(alpha, alpha, -1.0f) * cosTheta) * cosTheta) * t_0) * ((float) M_PI)));
}
function code(cosTheta, alpha) t_0 = log(Float32(alpha * alpha)) return Float32(Float32(Float32(alpha * alpha) - Float32(1.0)) / fma(Float32(pi), t_0, Float32(Float32(Float32(Float32(fma(alpha, alpha, Float32(-1.0)) * cosTheta) * cosTheta) * t_0) * Float32(pi)))) end
\begin{array}{l}
t_0 := \log \left(\alpha \cdot \alpha\right)\\
\frac{\alpha \cdot \alpha - 1}{\mathsf{fma}\left(\pi, t\_0, \left(\left(\left(\mathsf{fma}\left(\alpha, \alpha, -1\right) \cdot cosTheta\right) \cdot cosTheta\right) \cdot t\_0\right) \cdot \pi\right)}
\end{array}
Initial program 98.5%
Applied rewrites98.5%
(FPCore (cosTheta alpha)
:precision binary32
:pre (and (and (<= 0.0 cosTheta) (<= cosTheta 1.0))
(and (<= 0.0001 alpha) (<= alpha 1.0)))
(/
(/ 0.5 (log alpha))
(fma cosTheta (* cosTheta PI) (/ PI (fma alpha alpha -1.0)))))float code(float cosTheta, float alpha) {
return (0.5f / logf(alpha)) / fmaf(cosTheta, (cosTheta * ((float) M_PI)), (((float) M_PI) / fmaf(alpha, alpha, -1.0f)));
}
function code(cosTheta, alpha) return Float32(Float32(Float32(0.5) / log(alpha)) / fma(cosTheta, Float32(cosTheta * Float32(pi)), Float32(Float32(pi) / fma(alpha, alpha, Float32(-1.0))))) end
\frac{\frac{0.5}{\log \alpha}}{\mathsf{fma}\left(cosTheta, cosTheta \cdot \pi, \frac{\pi}{\mathsf{fma}\left(\alpha, \alpha, -1\right)}\right)}
Initial program 98.5%
Applied rewrites98.5%
Applied rewrites97.8%
Applied rewrites97.9%
Applied rewrites98.4%
(FPCore (cosTheta alpha)
:precision binary32
:pre (and (and (<= 0.0 cosTheta) (<= cosTheta 1.0))
(and (<= 0.0001 alpha) (<= alpha 1.0)))
(/
0.31830987334251404
(*
(log (* alpha alpha))
(fma cosTheta cosTheta (/ 1.0 (fma alpha alpha -1.0))))))float code(float cosTheta, float alpha) {
return 0.31830987334251404f / (logf((alpha * alpha)) * fmaf(cosTheta, cosTheta, (1.0f / fmaf(alpha, alpha, -1.0f))));
}
function code(cosTheta, alpha) return Float32(Float32(0.31830987334251404) / Float32(log(Float32(alpha * alpha)) * fma(cosTheta, cosTheta, Float32(Float32(1.0) / fma(alpha, alpha, Float32(-1.0)))))) end
\frac{0.31830987334251404}{\log \left(\alpha \cdot \alpha\right) \cdot \mathsf{fma}\left(cosTheta, cosTheta, \frac{1}{\mathsf{fma}\left(\alpha, \alpha, -1\right)}\right)}
Initial program 98.5%
Applied rewrites98.5%
Applied rewrites97.8%
Applied rewrites97.7%
Evaluated real constant97.7%
(FPCore (cosTheta alpha)
:precision binary32
:pre (and (and (<= 0.0 cosTheta) (<= cosTheta 1.0))
(and (<= 0.0001 alpha) (<= alpha 1.0)))
(/ (fma alpha alpha -1.0) (* (* 2.0 (log alpha)) PI)))float code(float cosTheta, float alpha) {
return fmaf(alpha, alpha, -1.0f) / ((2.0f * logf(alpha)) * ((float) M_PI));
}
function code(cosTheta, alpha) return Float32(fma(alpha, alpha, Float32(-1.0)) / Float32(Float32(Float32(2.0) * log(alpha)) * Float32(pi))) end
\frac{\mathsf{fma}\left(\alpha, \alpha, -1\right)}{\left(2 \cdot \log \alpha\right) \cdot \pi}
Initial program 98.5%
Applied rewrites98.5%
Taylor expanded in cosTheta around 0
Applied rewrites95.2%
Applied rewrites95.1%
Taylor expanded in alpha around 0
Applied rewrites95.2%
(FPCore (cosTheta alpha)
:precision binary32
:pre (and (and (<= 0.0 cosTheta) (<= cosTheta 1.0))
(and (<= 0.0001 alpha) (<= alpha 1.0)))
(/ (/ -1.0 PI) (* 2.0 (log alpha))))float code(float cosTheta, float alpha) {
return (-1.0f / ((float) M_PI)) / (2.0f * logf(alpha));
}
function code(cosTheta, alpha) return Float32(Float32(Float32(-1.0) / Float32(pi)) / Float32(Float32(2.0) * log(alpha))) end
function tmp = code(cosTheta, alpha) tmp = (single(-1.0) / single(pi)) / (single(2.0) * log(alpha)); end
\frac{\frac{-1}{\pi}}{2 \cdot \log \alpha}
Initial program 98.5%
Applied rewrites98.3%
Taylor expanded in cosTheta around 0
Applied rewrites95.0%
Applied rewrites95.1%
Taylor expanded in alpha around 0
Applied rewrites65.5%
(FPCore (cosTheta alpha)
:precision binary32
:pre (and (and (<= 0.0 cosTheta) (<= cosTheta 1.0))
(and (<= 0.0001 alpha) (<= alpha 1.0)))
(/ (/ -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
\frac{\frac{-1}{\pi}}{\log \left(\alpha \cdot \alpha\right)}
Initial program 98.5%
Applied rewrites98.3%
Taylor expanded in cosTheta around 0
Applied rewrites95.0%
Applied rewrites95.0%
Taylor expanded in alpha around 0
Applied rewrites65.5%
(FPCore (cosTheta alpha)
:precision binary32
:pre (and (and (<= 0.0 cosTheta) (<= cosTheta 1.0))
(and (<= 0.0001 alpha) (<= alpha 1.0)))
(/ -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(Float32(2.0) * log(alpha)) * Float32(pi))) end
function tmp = code(cosTheta, alpha) tmp = single(-1.0) / ((single(2.0) * log(alpha)) * single(pi)); end
\frac{-1}{\left(2 \cdot \log \alpha\right) \cdot \pi}
Initial program 98.5%
Applied rewrites98.5%
Taylor expanded in cosTheta around 0
Applied rewrites95.2%
Taylor expanded in alpha around 0
Applied rewrites95.1%
Taylor expanded in alpha around 0
Applied rewrites65.5%
herbie shell --seed 2026089 +o generate:egglog
(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)))))