
(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 4 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 (* (- 1.0 ux) maxCos)) (t_1 (* uy (* 2.0 PI))))
(fma
t_0
(* ux zi)
(*
(sqrt (+ 1.0 (* ux (* (* ux t_0) (* maxCos (+ ux -1.0))))))
(+ (* (cos t_1) xi) (* (sin t_1) yi))))))
float code(float xi, float yi, float zi, float ux, float uy, float maxCos) {
float t_0 = (1.0f - ux) * maxCos;
float t_1 = uy * (2.0f * ((float) M_PI));
return fmaf(t_0, (ux * zi), (sqrtf((1.0f + (ux * ((ux * t_0) * (maxCos * (ux + -1.0f)))))) * ((cosf(t_1) * xi) + (sinf(t_1) * yi))));
}
function code(xi, yi, zi, ux, uy, maxCos) t_0 = Float32(Float32(Float32(1.0) - ux) * maxCos) t_1 = Float32(uy * Float32(Float32(2.0) * Float32(pi))) return fma(t_0, Float32(ux * zi), Float32(sqrt(Float32(Float32(1.0) + Float32(ux * Float32(Float32(ux * t_0) * Float32(maxCos * Float32(ux + Float32(-1.0))))))) * Float32(Float32(cos(t_1) * xi) + Float32(sin(t_1) * yi)))) end
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \left(1 - ux\right) \cdot maxCos\\
t_1 := uy \cdot \left(2 \cdot \pi\right)\\
\mathsf{fma}\left(t\_0, ux \cdot zi, \sqrt{1 + ux \cdot \left(\left(ux \cdot t\_0\right) \cdot \left(maxCos \cdot \left(ux + -1\right)\right)\right)} \cdot \left(\cos t\_1 \cdot xi + \sin t\_1 \cdot yi\right)\right)
\end{array}
\end{array}
Initial program 99.1%
+-commutative99.1%
associate-*l*99.1%
fma-define99.1%
Simplified99.1%
Final simplification99.1%
(FPCore (xi yi zi ux uy maxCos)
:precision binary32
(let* ((t_0 (* (- 1.0 ux) maxCos)))
(fma
t_0
(* ux zi)
(*
(sqrt (+ 1.0 (* ux (* (* ux t_0) (* maxCos (+ ux -1.0))))))
(+ (* (cos (* uy (* 2.0 PI))) xi) (* yi (* PI (* uy 2.0))))))))
float code(float xi, float yi, float zi, float ux, float uy, float maxCos) {
float t_0 = (1.0f - ux) * maxCos;
return fmaf(t_0, (ux * zi), (sqrtf((1.0f + (ux * ((ux * t_0) * (maxCos * (ux + -1.0f)))))) * ((cosf((uy * (2.0f * ((float) M_PI)))) * xi) + (yi * (((float) M_PI) * (uy * 2.0f))))));
}
function code(xi, yi, zi, ux, uy, maxCos) t_0 = Float32(Float32(Float32(1.0) - ux) * maxCos) return fma(t_0, Float32(ux * zi), Float32(sqrt(Float32(Float32(1.0) + Float32(ux * Float32(Float32(ux * t_0) * Float32(maxCos * Float32(ux + Float32(-1.0))))))) * Float32(Float32(cos(Float32(uy * Float32(Float32(2.0) * Float32(pi)))) * xi) + Float32(yi * Float32(Float32(pi) * Float32(uy * Float32(2.0))))))) end
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \left(1 - ux\right) \cdot maxCos\\
\mathsf{fma}\left(t\_0, ux \cdot zi, \sqrt{1 + ux \cdot \left(\left(ux \cdot t\_0\right) \cdot \left(maxCos \cdot \left(ux + -1\right)\right)\right)} \cdot \left(\cos \left(uy \cdot \left(2 \cdot \pi\right)\right) \cdot xi + yi \cdot \left(\pi \cdot \left(uy \cdot 2\right)\right)\right)\right)
\end{array}
\end{array}
Initial program 99.1%
+-commutative99.1%
associate-*l*99.1%
fma-define99.1%
Simplified99.1%
Taylor expanded in uy around 0 88.0%
associate-*r*88.0%
*-commutative88.0%
*-commutative88.0%
*-commutative88.0%
*-commutative88.0%
Simplified88.0%
*-commutative88.0%
associate-*r*88.0%
*-commutative88.0%
associate-*r*88.0%
*-commutative88.0%
*-commutative88.0%
associate-*l*88.0%
Applied egg-rr88.0%
Final simplification88.0%
(FPCore (xi yi zi ux uy maxCos)
:precision binary32
(let* ((t_0 (* (- 1.0 ux) maxCos)))
(fma
t_0
(* ux zi)
(*
(sqrt (+ 1.0 (* ux (* (* ux t_0) (* maxCos (+ ux -1.0))))))
(+ (* (cos (* uy (* 2.0 PI))) xi) (* (* uy 2.0) (* PI yi)))))))
float code(float xi, float yi, float zi, float ux, float uy, float maxCos) {
float t_0 = (1.0f - ux) * maxCos;
return fmaf(t_0, (ux * zi), (sqrtf((1.0f + (ux * ((ux * t_0) * (maxCos * (ux + -1.0f)))))) * ((cosf((uy * (2.0f * ((float) M_PI)))) * xi) + ((uy * 2.0f) * (((float) M_PI) * yi)))));
}
function code(xi, yi, zi, ux, uy, maxCos) t_0 = Float32(Float32(Float32(1.0) - ux) * maxCos) return fma(t_0, Float32(ux * zi), Float32(sqrt(Float32(Float32(1.0) + Float32(ux * Float32(Float32(ux * t_0) * Float32(maxCos * Float32(ux + Float32(-1.0))))))) * Float32(Float32(cos(Float32(uy * Float32(Float32(2.0) * Float32(pi)))) * xi) + Float32(Float32(uy * Float32(2.0)) * Float32(Float32(pi) * yi))))) end
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \left(1 - ux\right) \cdot maxCos\\
\mathsf{fma}\left(t\_0, ux \cdot zi, \sqrt{1 + ux \cdot \left(\left(ux \cdot t\_0\right) \cdot \left(maxCos \cdot \left(ux + -1\right)\right)\right)} \cdot \left(\cos \left(uy \cdot \left(2 \cdot \pi\right)\right) \cdot xi + \left(uy \cdot 2\right) \cdot \left(\pi \cdot yi\right)\right)\right)
\end{array}
\end{array}
Initial program 99.1%
+-commutative99.1%
associate-*l*99.1%
fma-define99.1%
Simplified99.1%
Taylor expanded in uy around 0 88.0%
associate-*r*88.0%
*-commutative88.0%
*-commutative88.0%
*-commutative88.0%
*-commutative88.0%
Simplified88.0%
Final simplification88.0%
(FPCore (xi yi zi ux uy maxCos)
:precision binary32
(let* ((t_0 (* (- 1.0 ux) maxCos)))
(fma
t_0
(* ux zi)
(*
(sqrt (- 1.0 (* ux (* t_0 (* ux maxCos)))))
(+ (* (cos (* uy (* 2.0 PI))) xi) (* PI (* yi (* uy 2.0))))))))
float code(float xi, float yi, float zi, float ux, float uy, float maxCos) {
float t_0 = (1.0f - ux) * maxCos;
return fmaf(t_0, (ux * zi), (sqrtf((1.0f - (ux * (t_0 * (ux * maxCos))))) * ((cosf((uy * (2.0f * ((float) M_PI)))) * xi) + (((float) M_PI) * (yi * (uy * 2.0f))))));
}
function code(xi, yi, zi, ux, uy, maxCos) t_0 = Float32(Float32(Float32(1.0) - ux) * maxCos) return fma(t_0, Float32(ux * zi), Float32(sqrt(Float32(Float32(1.0) - Float32(ux * Float32(t_0 * Float32(ux * maxCos))))) * Float32(Float32(cos(Float32(uy * Float32(Float32(2.0) * Float32(pi)))) * xi) + Float32(Float32(pi) * Float32(yi * Float32(uy * Float32(2.0))))))) end
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \left(1 - ux\right) \cdot maxCos\\
\mathsf{fma}\left(t\_0, ux \cdot zi, \sqrt{1 - ux \cdot \left(t\_0 \cdot \left(ux \cdot maxCos\right)\right)} \cdot \left(\cos \left(uy \cdot \left(2 \cdot \pi\right)\right) \cdot xi + \pi \cdot \left(yi \cdot \left(uy \cdot 2\right)\right)\right)\right)
\end{array}
\end{array}
Initial program 99.1%
+-commutative99.1%
associate-*l*99.1%
fma-define99.1%
Simplified99.1%
Taylor expanded in uy around 0 88.0%
associate-*r*88.0%
*-commutative88.0%
*-commutative88.0%
*-commutative88.0%
*-commutative88.0%
Simplified88.0%
*-commutative88.0%
*-commutative88.0%
associate-*r*88.0%
Applied egg-rr88.0%
Taylor expanded in ux around 0 87.7%
Final simplification87.7%
herbie shell --seed 2024096
(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)))