
(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 23 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
(sqrt
(fma
(* maxCos (+ ux -1.0))
(* (* ux ux) (* (- 1.0 ux) maxCos))
1.0)))
(t_1 (* 2.0 (* uy PI))))
(fma
(- 1.0 ux)
(* zi (* ux maxCos))
(fma (* t_0 (sin t_1)) yi (* xi (* t_0 (cos t_1)))))))
float code(float xi, float yi, float zi, float ux, float uy, float maxCos) {
float t_0 = sqrtf(fmaf((maxCos * (ux + -1.0f)), ((ux * ux) * ((1.0f - ux) * maxCos)), 1.0f));
float t_1 = 2.0f * (uy * ((float) M_PI));
return fmaf((1.0f - ux), (zi * (ux * maxCos)), fmaf((t_0 * sinf(t_1)), yi, (xi * (t_0 * cosf(t_1)))));
}
function code(xi, yi, zi, ux, uy, maxCos) t_0 = sqrt(fma(Float32(maxCos * Float32(ux + Float32(-1.0))), Float32(Float32(ux * ux) * Float32(Float32(Float32(1.0) - ux) * maxCos)), Float32(1.0))) t_1 = Float32(Float32(2.0) * Float32(uy * Float32(pi))) return fma(Float32(Float32(1.0) - ux), Float32(zi * Float32(ux * maxCos)), fma(Float32(t_0 * sin(t_1)), yi, Float32(xi * Float32(t_0 * cos(t_1))))) end
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \sqrt{\mathsf{fma}\left(maxCos \cdot \left(ux + -1\right), \left(ux \cdot ux\right) \cdot \left(\left(1 - ux\right) \cdot maxCos\right), 1\right)}\\
t_1 := 2 \cdot \left(uy \cdot \pi\right)\\
\mathsf{fma}\left(1 - ux, zi \cdot \left(ux \cdot maxCos\right), \mathsf{fma}\left(t\_0 \cdot \sin t\_1, yi, xi \cdot \left(t\_0 \cdot \cos t\_1\right)\right)\right)
\end{array}
\end{array}
Initial program 98.8%
Applied rewrites98.8%
Applied rewrites98.9%
Final simplification98.9%
(FPCore (xi yi zi ux uy maxCos)
:precision binary32
(let* ((t_0 (* 2.0 (* uy PI))))
(*
zi
(fma
maxCos
(* ux (- 1.0 ux))
(/
(*
(fma xi (cos t_0) (* (sin t_0) yi))
(sqrt
(fma (* maxCos maxCos) (* (* ux ux) (* (- 1.0 ux) (+ ux -1.0))) 1.0)))
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 zi * fmaf(maxCos, (ux * (1.0f - ux)), ((fmaf(xi, cosf(t_0), (sinf(t_0) * yi)) * sqrtf(fmaf((maxCos * maxCos), ((ux * ux) * ((1.0f - ux) * (ux + -1.0f))), 1.0f))) / zi));
}
function code(xi, yi, zi, ux, uy, maxCos) t_0 = Float32(Float32(2.0) * Float32(uy * Float32(pi))) return Float32(zi * fma(maxCos, Float32(ux * Float32(Float32(1.0) - ux)), Float32(Float32(fma(xi, cos(t_0), Float32(sin(t_0) * yi)) * sqrt(fma(Float32(maxCos * maxCos), Float32(Float32(ux * ux) * Float32(Float32(Float32(1.0) - ux) * Float32(ux + Float32(-1.0)))), Float32(1.0)))) / zi))) end
\begin{array}{l}
\\
\begin{array}{l}
t_0 := 2 \cdot \left(uy \cdot \pi\right)\\
zi \cdot \mathsf{fma}\left(maxCos, ux \cdot \left(1 - ux\right), \frac{\mathsf{fma}\left(xi, \cos t\_0, \sin t\_0 \cdot yi\right) \cdot \sqrt{\mathsf{fma}\left(maxCos \cdot maxCos, \left(ux \cdot ux\right) \cdot \left(\left(1 - ux\right) \cdot \left(ux + -1\right)\right), 1\right)}}{zi}\right)
\end{array}
\end{array}
Initial program 98.9%
Taylor expanded in zi around -inf
Applied rewrites98.3%
Final simplification98.3%
herbie shell --seed 2024228
(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)))