
(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 13 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
(pow
(* alpha alpha)
(* (* (fma (* (fma alpha alpha -1.0) cosTheta) cosTheta 1.0) 0.5) PI))))))
float code(float cosTheta, float alpha) {
return ((alpha * alpha) - 1.0f) / (2.0f * logf(powf((alpha * alpha), ((fmaf((fmaf(alpha, alpha, -1.0f) * cosTheta), cosTheta, 1.0f) * 0.5f) * ((float) M_PI)))));
}
function code(cosTheta, alpha) return Float32(Float32(Float32(alpha * alpha) - Float32(1.0)) / Float32(Float32(2.0) * log((Float32(alpha * alpha) ^ Float32(Float32(fma(Float32(fma(alpha, alpha, Float32(-1.0)) * cosTheta), cosTheta, Float32(1.0)) * Float32(0.5)) * Float32(pi)))))) end
\begin{array}{l}
\\
\frac{\alpha \cdot \alpha - 1}{2 \cdot \log \left({\left(\alpha \cdot \alpha\right)}^{\left(\left(\mathsf{fma}\left(\mathsf{fma}\left(\alpha, \alpha, -1\right) \cdot cosTheta, cosTheta, 1\right) \cdot 0.5\right) \cdot \pi\right)}\right)}
\end{array}
Initial program 98.5%
lift-*.f32N/A
*-commutativeN/A
lift-*.f32N/A
associate-*r*N/A
lift-log.f32N/A
log-pow-revN/A
lower-log.f32N/A
lower-pow.f32N/A
lower-*.f3298.6
Applied rewrites98.6%
lift-pow.f32N/A
sqr-powN/A
lower-unsound-*.f32N/A
lower-unsound-pow.f32N/A
lower-unsound-/.f32N/A
lift-*.f32N/A
*-commutativeN/A
lower-*.f32N/A
lower-unsound-pow.f32N/A
lower-unsound-/.f3298.6
lift-*.f32N/A
*-commutativeN/A
lower-*.f3298.6
Applied rewrites98.6%
lift-log.f32N/A
lift-*.f32N/A
pow2N/A
log-powN/A
lower-unsound-*.f32N/A
lower-unsound-log.f3298.6
lift-/.f32N/A
lift-*.f32N/A
associate-/l*N/A
*-commutativeN/A
lower-*.f32N/A
Applied rewrites98.6%
(FPCore (cosTheta alpha)
:precision binary32
(/
(- (* alpha alpha) 1.0)
(log
(pow
(* alpha alpha)
(* (fma (* (fma alpha alpha -1.0) cosTheta) cosTheta 1.0) PI)))))
float code(float cosTheta, float alpha) {
return ((alpha * alpha) - 1.0f) / logf(powf((alpha * alpha), (fmaf((fmaf(alpha, alpha, -1.0f) * cosTheta), cosTheta, 1.0f) * ((float) M_PI))));
}
function code(cosTheta, alpha) return Float32(Float32(Float32(alpha * alpha) - Float32(1.0)) / log((Float32(alpha * alpha) ^ Float32(fma(Float32(fma(alpha, alpha, Float32(-1.0)) * cosTheta), cosTheta, Float32(1.0)) * Float32(pi))))) end
\begin{array}{l}
\\
\frac{\alpha \cdot \alpha - 1}{\log \left({\left(\alpha \cdot \alpha\right)}^{\left(\mathsf{fma}\left(\mathsf{fma}\left(\alpha, \alpha, -1\right) \cdot cosTheta, cosTheta, 1\right) \cdot \pi\right)}\right)}
\end{array}
Initial program 98.5%
lift-*.f32N/A
*-commutativeN/A
lift-*.f32N/A
associate-*r*N/A
lift-log.f32N/A
log-pow-revN/A
lower-log.f32N/A
lower-pow.f32N/A
lower-*.f3298.6
Applied rewrites98.6%
(FPCore (cosTheta alpha)
:precision binary32
(/
(/
(fma alpha alpha -1.0)
(*
(fma (* (fma alpha alpha -1.0) cosTheta) cosTheta 1.0)
(* 2.0 (log alpha))))
PI))
float code(float cosTheta, float alpha) {
return (fmaf(alpha, alpha, -1.0f) / (fmaf((fmaf(alpha, alpha, -1.0f) * cosTheta), cosTheta, 1.0f) * (2.0f * logf(alpha)))) / ((float) M_PI);
}
function code(cosTheta, alpha) return Float32(Float32(fma(alpha, alpha, Float32(-1.0)) / Float32(fma(Float32(fma(alpha, alpha, Float32(-1.0)) * cosTheta), cosTheta, Float32(1.0)) * Float32(Float32(2.0) * log(alpha)))) / Float32(pi)) end
\begin{array}{l}
\\
\frac{\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(2 \cdot \log \alpha\right)}}{\pi}
\end{array}
Initial program 98.5%
lift-/.f32N/A
lift-*.f32N/A
lift-*.f32N/A
associate-*l*N/A
*-commutativeN/A
associate-/r*N/A
lower-/.f32N/A
Applied rewrites98.4%
lift-log.f32N/A
lift-*.f32N/A
pow2N/A
log-powN/A
lower-unsound-*.f32N/A
lower-unsound-log.f3298.5
Applied rewrites98.5%
(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(Float32(fma(Float32(fma(alpha, alpha, Float32(-1.0)) * cosTheta), cosTheta, Float32(1.0)) * log(Float32(alpha * alpha))) * Float32(pi))) end
\begin{array}{l}
\\
\frac{\alpha \cdot \alpha - 1}{\left(\mathsf{fma}\left(\mathsf{fma}\left(\alpha, \alpha, -1\right) \cdot cosTheta, cosTheta, 1\right) \cdot \log \left(\alpha \cdot \alpha\right)\right) \cdot \pi}
\end{array}
Initial program 98.5%
lift-*.f32N/A
lift-*.f32N/A
associate-*l*N/A
*-commutativeN/A
lower-*.f32N/A
Applied rewrites98.5%
(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(fma(alpha, alpha, Float32(-1.0)), 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(\mathsf{fma}\left(\alpha, \alpha, -1\right), cosTheta \cdot cosTheta, 1\right)}
\end{array}
Initial program 98.5%
lift-+.f32N/A
+-commutativeN/A
lift-*.f32N/A
lift-*.f32N/A
associate-*l*N/A
lower-fma.f32N/A
remove-double-negN/A
lift--.f32N/A
sub-flipN/A
distribute-neg-inN/A
remove-double-negN/A
distribute-neg-inN/A
lift-*.f32N/A
sqr-abs-revN/A
distribute-rgt-neg-inN/A
distribute-lft-neg-outN/A
sqr-neg-revN/A
sqr-abs-revN/A
lower-fma.f32N/A
metadata-evalN/A
lower-*.f3298.5
Applied rewrites98.5%
(FPCore (cosTheta alpha) :precision binary32 (/ (fma alpha alpha -1.0) (* (* (fma (* (fma alpha alpha -1.0) cosTheta) cosTheta 1.0) PI) (log (* alpha alpha)))))
float code(float cosTheta, float alpha) {
return fmaf(alpha, alpha, -1.0f) / ((fmaf((fmaf(alpha, alpha, -1.0f) * cosTheta), cosTheta, 1.0f) * ((float) M_PI)) * logf((alpha * alpha)));
}
function code(cosTheta, alpha) return Float32(fma(alpha, alpha, Float32(-1.0)) / Float32(Float32(fma(Float32(fma(alpha, alpha, Float32(-1.0)) * cosTheta), cosTheta, Float32(1.0)) * Float32(pi)) * log(Float32(alpha * alpha)))) end
\begin{array}{l}
\\
\frac{\mathsf{fma}\left(\alpha, \alpha, -1\right)}{\left(\mathsf{fma}\left(\mathsf{fma}\left(\alpha, \alpha, -1\right) \cdot cosTheta, cosTheta, 1\right) \cdot \pi\right) \cdot \log \left(\alpha \cdot \alpha\right)}
\end{array}
Initial program 98.5%
remove-double-negN/A
lift--.f32N/A
sub-flipN/A
distribute-neg-inN/A
remove-double-negN/A
distribute-neg-inN/A
lift-*.f32N/A
sqr-abs-revN/A
distribute-rgt-neg-inN/A
distribute-lft-neg-outN/A
sqr-neg-revN/A
sqr-abs-revN/A
lower-fma.f32N/A
metadata-eval98.4
lift-*.f32N/A
*-commutativeN/A
lift-*.f32N/A
associate-*r*N/A
Applied rewrites98.4%
(FPCore (cosTheta alpha) :precision binary32 (/ (- (* alpha alpha) 1.0) (* (* PI (log (* alpha alpha))) (+ 1.0 (* (* -1.0 cosTheta) cosTheta)))))
float code(float cosTheta, float alpha) {
return ((alpha * alpha) - 1.0f) / ((((float) M_PI) * logf((alpha * alpha))) * (1.0f + ((-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(Float32(Float32(-1.0) * cosTheta) * cosTheta)))) end
function tmp = code(cosTheta, alpha) tmp = ((alpha * alpha) - single(1.0)) / ((single(pi) * log((alpha * alpha))) * (single(1.0) + ((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 + \left(-1 \cdot cosTheta\right) \cdot cosTheta\right)}
\end{array}
Initial program 98.5%
Taylor expanded in alpha around 0
lower-*.f3297.5
Applied rewrites97.5%
(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(Float32(fma(Float32(-cosTheta), cosTheta, Float32(1.0)) * log(Float32(alpha * alpha))) * Float32(pi))) end
\begin{array}{l}
\\
\frac{\mathsf{fma}\left(\alpha, \alpha, -1\right)}{\left(\mathsf{fma}\left(-cosTheta, cosTheta, 1\right) \cdot \log \left(\alpha \cdot \alpha\right)\right) \cdot \pi}
\end{array}
Initial program 98.5%
lift-/.f32N/A
lift-*.f32N/A
lift-*.f32N/A
associate-*l*N/A
*-commutativeN/A
associate-/r*N/A
lower-/.f32N/A
Applied rewrites98.4%
Taylor expanded in alpha around 0
lower-*.f3297.5
Applied rewrites97.5%
Applied rewrites97.5%
(FPCore (cosTheta alpha) :precision binary32 (/ (- (* alpha alpha) 1.0) (* (* PI (log (* alpha alpha))) 1.0)))
float code(float cosTheta, float alpha) {
return ((alpha * alpha) - 1.0f) / ((((float) M_PI) * logf((alpha * alpha))) * 1.0f);
}
function code(cosTheta, alpha) return Float32(Float32(Float32(alpha * alpha) - Float32(1.0)) / Float32(Float32(Float32(pi) * log(Float32(alpha * alpha))) * Float32(1.0))) end
function tmp = code(cosTheta, alpha) tmp = ((alpha * alpha) - single(1.0)) / ((single(pi) * log((alpha * alpha))) * single(1.0)); end
\begin{array}{l}
\\
\frac{\alpha \cdot \alpha - 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%
(FPCore (cosTheta alpha) :precision binary32 (/ (fma alpha alpha -1.0) (* (* (* (log alpha) 2.0) 1.0) PI)))
float code(float cosTheta, float alpha) {
return fmaf(alpha, alpha, -1.0f) / (((logf(alpha) * 2.0f) * 1.0f) * ((float) M_PI));
}
function code(cosTheta, alpha) return Float32(fma(alpha, alpha, Float32(-1.0)) / Float32(Float32(Float32(log(alpha) * Float32(2.0)) * Float32(1.0)) * Float32(pi))) end
\begin{array}{l}
\\
\frac{\mathsf{fma}\left(\alpha, \alpha, -1\right)}{\left(\left(\log \alpha \cdot 2\right) \cdot 1\right) \cdot \pi}
\end{array}
Initial program 98.5%
Taylor expanded in cosTheta around 0
Applied rewrites95.2%
Taylor expanded in alpha around inf
lower-*.f32N/A
lower-log.f32N/A
lower-/.f3295.0
Applied rewrites95.0%
lift--.f32N/A
lift-*.f32N/A
difference-of-sqr-1N/A
difference-of-sqr--1N/A
lift-fma.f3295.0
lift-*.f32N/A
lift-*.f32N/A
associate-*l*N/A
*-commutativeN/A
lower-*.f32N/A
Applied rewrites95.2%
(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(Float32(fma(alpha, alpha, Float32(-1.0)) / Float32(pi)) / log(Float32(alpha * alpha))) end
\begin{array}{l}
\\
\frac{\frac{\mathsf{fma}\left(\alpha, \alpha, -1\right)}{\pi}}{\log \left(\alpha \cdot \alpha\right)}
\end{array}
Initial program 98.5%
Taylor expanded in cosTheta around 0
Applied rewrites95.2%
lift-/.f32N/A
mult-flipN/A
lift--.f32N/A
lift-*.f32N/A
difference-of-sqr-1N/A
difference-of-sqr--1N/A
lift-fma.f32N/A
lower-*.f32N/A
lower-/.f3295.0
lift-*.f32N/A
*-commutativeN/A
lift-*.f32N/A
associate-*r*N/A
Applied rewrites95.0%
lift-*.f32N/A
lift-/.f32N/A
mult-flip-revN/A
lift-*.f32N/A
associate-/r*N/A
lower-/.f32N/A
lower-/.f3295.1
Applied rewrites95.1%
Taylor expanded in cosTheta around 0
lower-PI.f3295.1
Applied rewrites95.1%
(FPCore (cosTheta alpha) :precision binary32 (* (/ (/ 0.5 (log alpha)) (* 1.0 PI)) -1.0))
float code(float cosTheta, float alpha) {
return ((0.5f / logf(alpha)) / (1.0f * ((float) M_PI))) * -1.0f;
}
function code(cosTheta, alpha) return Float32(Float32(Float32(Float32(0.5) / log(alpha)) / Float32(Float32(1.0) * Float32(pi))) * Float32(-1.0)) end
function tmp = code(cosTheta, alpha) tmp = ((single(0.5) / log(alpha)) / (single(1.0) * single(pi))) * single(-1.0); end
\begin{array}{l}
\\
\frac{\frac{0.5}{\log \alpha}}{1 \cdot \pi} \cdot -1
\end{array}
Initial program 98.5%
Taylor expanded in cosTheta around 0
Applied rewrites95.2%
Taylor expanded in alpha around 0
Applied rewrites65.4%
lift-/.f32N/A
mult-flipN/A
lift-*.f32N/A
*-commutativeN/A
lift-*.f32N/A
associate-*l*N/A
lift-*.f32N/A
lift-*.f32N/A
lift-/.f32N/A
Applied rewrites65.4%
(FPCore (cosTheta alpha) :precision binary32 (/ -1.0 (* 2.0 (* PI (log alpha)))))
float code(float cosTheta, float alpha) {
return -1.0f / (2.0f * (((float) M_PI) * logf(alpha)));
}
function code(cosTheta, alpha) return Float32(Float32(-1.0) / Float32(Float32(2.0) * Float32(Float32(pi) * log(alpha)))) end
function tmp = code(cosTheta, alpha) tmp = single(-1.0) / (single(2.0) * (single(pi) * log(alpha))); end
\begin{array}{l}
\\
\frac{-1}{2 \cdot \left(\pi \cdot \log \alpha\right)}
\end{array}
Initial program 98.5%
Taylor expanded in cosTheta around 0
Applied rewrites95.2%
Taylor expanded in alpha around 0
Applied rewrites65.4%
lift-log.f32N/A
lift-*.f32N/A
pow2N/A
log-pow-revN/A
lift-log.f32N/A
lower-*.f3265.4
Applied rewrites65.4%
Taylor expanded in cosTheta around 0
lower-*.f32N/A
lower-*.f32N/A
lower-PI.f32N/A
lower-log.f3265.4
Applied rewrites65.4%
herbie shell --seed 2025157
(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)))))