\sin \left(\left(uy \cdot 2\right) \cdot \pi\right) \cdot \sqrt{1 - \left(\left(1 - ux\right) + ux \cdot maxCos\right) \cdot \left(\left(1 - ux\right) + ux \cdot maxCos\right)}
\sin \left(\sqrt[3]{{\left({\pi}^{\left(\sqrt{3}\right)}\right)}^{\left(\sqrt{3}\right)} \cdot \left({uy}^{3} \cdot 8\right)}\right) \cdot \sqrt{\left(2 \cdot \left(maxCos \cdot {ux}^{2}\right) + 2 \cdot ux\right) - \left({ux}^{2} + \left({ux}^{2} \cdot {maxCos}^{2} + 2 \cdot \left(maxCos \cdot ux\right)\right)\right)}
(FPCore (ux uy maxCos) :precision binary32 (* (sin (* (* uy 2.0) PI)) (sqrt (- 1.0 (* (+ (- 1.0 ux) (* ux maxCos)) (+ (- 1.0 ux) (* ux maxCos)))))))
(FPCore (ux uy maxCos)
:precision binary32
(*
(sin (cbrt (* (pow (pow PI (sqrt 3.0)) (sqrt 3.0)) (* (pow uy 3.0) 8.0))))
(sqrt
(-
(+ (* 2.0 (* maxCos (pow ux 2.0))) (* 2.0 ux))
(+
(pow ux 2.0)
(+ (* (pow ux 2.0) (pow maxCos 2.0)) (* 2.0 (* maxCos ux))))))))float code(float ux, float uy, float maxCos) {
return sinf((uy * 2.0f) * ((float) M_PI)) * sqrtf(1.0f - (((1.0f - ux) + (ux * maxCos)) * ((1.0f - ux) + (ux * maxCos))));
}
float code(float ux, float uy, float maxCos) {
return sinf(cbrtf(powf(powf(((float) M_PI), sqrtf(3.0f)), sqrtf(3.0f)) * (powf(uy, 3.0f) * 8.0f))) * sqrtf(((2.0f * (maxCos * powf(ux, 2.0f))) + (2.0f * ux)) - (powf(ux, 2.0f) + ((powf(ux, 2.0f) * powf(maxCos, 2.0f)) + (2.0f * (maxCos * ux)))));
}



Bits error versus ux



Bits error versus uy



Bits error versus maxCos
Results
Initial program 13.6
Taylor expanded in ux around 0 0.5
Applied add-cbrt-cube_binary320.5
Applied add-cbrt-cube_binary320.5
Applied add-cbrt-cube_binary320.6
Applied cbrt-unprod_binary320.6
Applied cbrt-unprod_binary320.6
Simplified0.6
Applied add-sqr-sqrt_binary320.6
Applied pow-unpow_binary320.5
Final simplification0.5
herbie shell --seed 2022081
(FPCore (ux uy maxCos)
:name "UniformSampleCone, y"
:precision binary32
:pre (and (and (and (<= 2.328306437e-10 ux) (<= ux 1.0)) (and (<= 2.328306437e-10 uy) (<= uy 1.0))) (and (<= 0.0 maxCos) (<= maxCos 1.0)))
(* (sin (* (* uy 2.0) PI)) (sqrt (- 1.0 (* (+ (- 1.0 ux) (* ux maxCos)) (+ (- 1.0 ux) (* ux maxCos)))))))