
(FPCore (xi yi zi ux uy maxCos)
:precision binary32
(let* ((t_0 (* (* (- 1.0 ux) maxCos) ux))
(t_1 (sqrt (- 1.0 (* t_0 t_0))))
(t_2 (* (* uy 2.0) PI)))
(+ (+ (* (* (cos t_2) t_1) xi) (* (* (sin t_2) t_1) yi)) (* t_0 zi))))
float code(float xi, float yi, float zi, float ux, float uy, float maxCos) {
float t_0 = ((1.0f - ux) * maxCos) * ux;
float t_1 = sqrtf((1.0f - (t_0 * t_0)));
float t_2 = (uy * 2.0f) * ((float) M_PI);
return (((cosf(t_2) * t_1) * xi) + ((sinf(t_2) * t_1) * yi)) + (t_0 * zi);
}
function code(xi, yi, zi, ux, uy, maxCos) t_0 = Float32(Float32(Float32(Float32(1.0) - ux) * maxCos) * ux) t_1 = sqrt(Float32(Float32(1.0) - Float32(t_0 * t_0))) t_2 = Float32(Float32(uy * Float32(2.0)) * Float32(pi)) return Float32(Float32(Float32(Float32(cos(t_2) * t_1) * xi) + Float32(Float32(sin(t_2) * t_1) * yi)) + Float32(t_0 * zi)) end
function tmp = code(xi, yi, zi, ux, uy, maxCos) t_0 = ((single(1.0) - ux) * maxCos) * ux; t_1 = sqrt((single(1.0) - (t_0 * t_0))); t_2 = (uy * single(2.0)) * single(pi); tmp = (((cos(t_2) * t_1) * xi) + ((sin(t_2) * t_1) * yi)) + (t_0 * zi); end
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \left(\left(1 - ux\right) \cdot maxCos\right) \cdot ux\\
t_1 := \sqrt{1 - t\_0 \cdot t\_0}\\
t_2 := \left(uy \cdot 2\right) \cdot \pi\\
\left(\left(\cos t\_2 \cdot t\_1\right) \cdot xi + \left(\sin t\_2 \cdot t\_1\right) \cdot yi\right) + t\_0 \cdot zi
\end{array}
\end{array}
Sampling outcomes in binary32 precision:
Herbie found 25 alternatives:
| Alternative | Accuracy | Speedup |
|---|
(FPCore (xi yi zi ux uy maxCos)
:precision binary32
(let* ((t_0 (* (* (- 1.0 ux) maxCos) ux))
(t_1 (sqrt (- 1.0 (* t_0 t_0))))
(t_2 (* (* uy 2.0) PI)))
(+ (+ (* (* (cos t_2) t_1) xi) (* (* (sin t_2) t_1) yi)) (* t_0 zi))))
float code(float xi, float yi, float zi, float ux, float uy, float maxCos) {
float t_0 = ((1.0f - ux) * maxCos) * ux;
float t_1 = sqrtf((1.0f - (t_0 * t_0)));
float t_2 = (uy * 2.0f) * ((float) M_PI);
return (((cosf(t_2) * t_1) * xi) + ((sinf(t_2) * t_1) * yi)) + (t_0 * zi);
}
function code(xi, yi, zi, ux, uy, maxCos) t_0 = Float32(Float32(Float32(Float32(1.0) - ux) * maxCos) * ux) t_1 = sqrt(Float32(Float32(1.0) - Float32(t_0 * t_0))) t_2 = Float32(Float32(uy * Float32(2.0)) * Float32(pi)) return Float32(Float32(Float32(Float32(cos(t_2) * t_1) * xi) + Float32(Float32(sin(t_2) * t_1) * yi)) + Float32(t_0 * zi)) end
function tmp = code(xi, yi, zi, ux, uy, maxCos) t_0 = ((single(1.0) - ux) * maxCos) * ux; t_1 = sqrt((single(1.0) - (t_0 * t_0))); t_2 = (uy * single(2.0)) * single(pi); tmp = (((cos(t_2) * t_1) * xi) + ((sin(t_2) * t_1) * yi)) + (t_0 * zi); end
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \left(\left(1 - ux\right) \cdot maxCos\right) \cdot ux\\
t_1 := \sqrt{1 - t\_0 \cdot t\_0}\\
t_2 := \left(uy \cdot 2\right) \cdot \pi\\
\left(\left(\cos t\_2 \cdot t\_1\right) \cdot xi + \left(\sin t\_2 \cdot t\_1\right) \cdot yi\right) + t\_0 \cdot zi
\end{array}
\end{array}
(FPCore (xi yi zi ux uy maxCos)
:precision binary32
(let* ((t_0 (* uy (* 2.0 PI))))
(fma
(* (- 1.0 ux) maxCos)
(* ux zi)
(*
(sqrt
(fma (* maxCos maxCos) (* ux (* (- 1.0 ux) (* ux (+ ux -1.0)))) 1.0))
(fma yi (sin t_0) (* xi (cos t_0)))))))
float code(float xi, float yi, float zi, float ux, float uy, float maxCos) {
float t_0 = uy * (2.0f * ((float) M_PI));
return fmaf(((1.0f - ux) * maxCos), (ux * zi), (sqrtf(fmaf((maxCos * maxCos), (ux * ((1.0f - ux) * (ux * (ux + -1.0f)))), 1.0f)) * fmaf(yi, sinf(t_0), (xi * cosf(t_0)))));
}
function code(xi, yi, zi, ux, uy, maxCos) t_0 = Float32(uy * Float32(Float32(2.0) * Float32(pi))) return fma(Float32(Float32(Float32(1.0) - ux) * maxCos), Float32(ux * zi), Float32(sqrt(fma(Float32(maxCos * maxCos), Float32(ux * Float32(Float32(Float32(1.0) - ux) * Float32(ux * Float32(ux + Float32(-1.0))))), Float32(1.0))) * fma(yi, sin(t_0), Float32(xi * cos(t_0))))) end
\begin{array}{l}
\\
\begin{array}{l}
t_0 := uy \cdot \left(2 \cdot \pi\right)\\
\mathsf{fma}\left(\left(1 - ux\right) \cdot maxCos, ux \cdot zi, \sqrt{\mathsf{fma}\left(maxCos \cdot maxCos, ux \cdot \left(\left(1 - ux\right) \cdot \left(ux \cdot \left(ux + -1\right)\right)\right), 1\right)} \cdot \mathsf{fma}\left(yi, \sin t\_0, xi \cdot \cos t\_0\right)\right)
\end{array}
\end{array}
Initial program 98.7%
lift-+.f32N/A
+-commutativeN/A
lift-*.f32N/A
lift-*.f32N/A
associate-*l*N/A
Applied rewrites98.7%
Applied rewrites98.7%
Applied rewrites98.7%
Final simplification98.7%
(FPCore (xi yi zi ux uy maxCos) :precision binary32 (let* ((t_0 (* 2.0 (* uy PI)))) (fma xi (cos t_0) (fma yi (sin t_0) (* maxCos (* (- 1.0 ux) (* ux zi)))))))
float code(float xi, float yi, float zi, float ux, float uy, float maxCos) {
float t_0 = 2.0f * (uy * ((float) M_PI));
return fmaf(xi, cosf(t_0), fmaf(yi, sinf(t_0), (maxCos * ((1.0f - ux) * (ux * zi)))));
}
function code(xi, yi, zi, ux, uy, maxCos) t_0 = Float32(Float32(2.0) * Float32(uy * Float32(pi))) return fma(xi, cos(t_0), fma(yi, sin(t_0), Float32(maxCos * Float32(Float32(Float32(1.0) - ux) * Float32(ux * zi))))) end
\begin{array}{l}
\\
\begin{array}{l}
t_0 := 2 \cdot \left(uy \cdot \pi\right)\\
\mathsf{fma}\left(xi, \cos t\_0, \mathsf{fma}\left(yi, \sin t\_0, maxCos \cdot \left(\left(1 - ux\right) \cdot \left(ux \cdot zi\right)\right)\right)\right)
\end{array}
\end{array}
Initial program 98.9%
Taylor expanded in maxCos around 0
+-commutativeN/A
associate-+l+N/A
lower-fma.f32N/A
lower-cos.f32N/A
lower-*.f32N/A
lower-*.f32N/A
lower-PI.f32N/A
lower-fma.f32N/A
lower-sin.f32N/A
lower-*.f32N/A
lower-*.f32N/A
lower-PI.f32N/A
lower-*.f32N/A
associate-*r*N/A
lower-*.f32N/A
lower-*.f32N/A
Applied rewrites98.7%
Final simplification98.7%
herbie shell --seed 2024226
(FPCore (xi yi zi ux uy maxCos)
:name "UniformSampleCone 2"
:precision binary32
:pre (and (and (and (and (and (and (<= -10000.0 xi) (<= xi 10000.0)) (and (<= -10000.0 yi) (<= yi 10000.0))) (and (<= -10000.0 zi) (<= zi 10000.0))) (and (<= 2.328306437e-10 ux) (<= ux 1.0))) (and (<= 2.328306437e-10 uy) (<= uy 1.0))) (and (<= 0.0 maxCos) (<= maxCos 1.0)))
(+ (+ (* (* (cos (* (* uy 2.0) PI)) (sqrt (- 1.0 (* (* (* (- 1.0 ux) maxCos) ux) (* (* (- 1.0 ux) maxCos) ux))))) xi) (* (* (sin (* (* uy 2.0) PI)) (sqrt (- 1.0 (* (* (* (- 1.0 ux) maxCos) ux) (* (* (- 1.0 ux) maxCos) ux))))) yi)) (* (* (* (- 1.0 ux) maxCos) ux) zi)))