
(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 6 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
(fma
ux
(* (- 1.0 ux) (* maxCos zi))
(*
(sqrt (- 1.0 (* ux (* ux (* maxCos maxCos)))))
(+
(* (cos (* uy (* 2.0 PI))) xi)
(* (sin (log1p (expm1 (* 2.0 (* uy PI))))) yi)))))
float code(float xi, float yi, float zi, float ux, float uy, float maxCos) {
return fmaf(ux, ((1.0f - ux) * (maxCos * zi)), (sqrtf((1.0f - (ux * (ux * (maxCos * maxCos))))) * ((cosf((uy * (2.0f * ((float) M_PI)))) * xi) + (sinf(log1pf(expm1f((2.0f * (uy * ((float) M_PI)))))) * yi))));
}
function code(xi, yi, zi, ux, uy, maxCos) return fma(ux, Float32(Float32(Float32(1.0) - ux) * Float32(maxCos * zi)), Float32(sqrt(Float32(Float32(1.0) - Float32(ux * Float32(ux * Float32(maxCos * maxCos))))) * Float32(Float32(cos(Float32(uy * Float32(Float32(2.0) * Float32(pi)))) * xi) + Float32(sin(log1p(expm1(Float32(Float32(2.0) * Float32(uy * Float32(pi)))))) * yi)))) end
\begin{array}{l}
\\
\mathsf{fma}\left(ux, \left(1 - ux\right) \cdot \left(maxCos \cdot zi\right), \sqrt{1 - ux \cdot \left(ux \cdot \left(maxCos \cdot maxCos\right)\right)} \cdot \left(\cos \left(uy \cdot \left(2 \cdot \pi\right)\right) \cdot xi + \sin \left(\mathsf{log1p}\left(\mathsf{expm1}\left(2 \cdot \left(uy \cdot \pi\right)\right)\right)\right) \cdot yi\right)\right)
\end{array}
Initial program 99.0%
Simplified99.0%
associate-*r*99.0%
log1p-expm1-u99.0%
*-commutative99.0%
associate-*l*99.0%
Applied egg-rr99.0%
Taylor expanded in ux around 0 99.0%
Final simplification99.0%
(FPCore (xi yi zi ux uy maxCos)
:precision binary32
(let* ((t_0 (* uy (* 2.0 PI))))
(fma
ux
(* (- 1.0 ux) (* maxCos zi))
(*
(sqrt (- 1.0 (* ux (* ux (* maxCos maxCos)))))
(+ (* (cos t_0) xi) (* yi (sin 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(ux, ((1.0f - ux) * (maxCos * zi)), (sqrtf((1.0f - (ux * (ux * (maxCos * maxCos))))) * ((cosf(t_0) * xi) + (yi * sinf(t_0)))));
}
function code(xi, yi, zi, ux, uy, maxCos) t_0 = Float32(uy * Float32(Float32(2.0) * Float32(pi))) return fma(ux, Float32(Float32(Float32(1.0) - ux) * Float32(maxCos * zi)), Float32(sqrt(Float32(Float32(1.0) - Float32(ux * Float32(ux * Float32(maxCos * maxCos))))) * Float32(Float32(cos(t_0) * xi) + Float32(yi * sin(t_0))))) end
\begin{array}{l}
\\
\begin{array}{l}
t_0 := uy \cdot \left(2 \cdot \pi\right)\\
\mathsf{fma}\left(ux, \left(1 - ux\right) \cdot \left(maxCos \cdot zi\right), \sqrt{1 - ux \cdot \left(ux \cdot \left(maxCos \cdot maxCos\right)\right)} \cdot \left(\cos t_0 \cdot xi + yi \cdot \sin t_0\right)\right)
\end{array}
\end{array}
Initial program 99.0%
Simplified99.0%
Taylor expanded in ux around 0 99.0%
Final simplification99.0%
(FPCore (xi yi zi ux uy maxCos)
:precision binary32
(fma
ux
(* (- 1.0 ux) (* maxCos zi))
(*
(sqrt
(+ 1.0 (* ux (* ux (* maxCos (* maxCos (* (- 1.0 ux) (+ ux -1.0))))))))
(+ (* (cos (* uy (* 2.0 PI))) xi) (* 2.0 (* PI (* uy yi)))))))
float code(float xi, float yi, float zi, float ux, float uy, float maxCos) {
return fmaf(ux, ((1.0f - ux) * (maxCos * zi)), (sqrtf((1.0f + (ux * (ux * (maxCos * (maxCos * ((1.0f - ux) * (ux + -1.0f)))))))) * ((cosf((uy * (2.0f * ((float) M_PI)))) * xi) + (2.0f * (((float) M_PI) * (uy * yi))))));
}
function code(xi, yi, zi, ux, uy, maxCos) return fma(ux, Float32(Float32(Float32(1.0) - ux) * Float32(maxCos * zi)), Float32(sqrt(Float32(Float32(1.0) + Float32(ux * Float32(ux * Float32(maxCos * Float32(maxCos * Float32(Float32(Float32(1.0) - ux) * Float32(ux + Float32(-1.0))))))))) * Float32(Float32(cos(Float32(uy * Float32(Float32(2.0) * Float32(pi)))) * xi) + Float32(Float32(2.0) * Float32(Float32(pi) * Float32(uy * yi)))))) end
\begin{array}{l}
\\
\mathsf{fma}\left(ux, \left(1 - ux\right) \cdot \left(maxCos \cdot zi\right), \sqrt{1 + ux \cdot \left(ux \cdot \left(maxCos \cdot \left(maxCos \cdot \left(\left(1 - ux\right) \cdot \left(ux + -1\right)\right)\right)\right)\right)} \cdot \left(\cos \left(uy \cdot \left(2 \cdot \pi\right)\right) \cdot xi + 2 \cdot \left(\pi \cdot \left(uy \cdot yi\right)\right)\right)\right)
\end{array}
Initial program 99.0%
Simplified99.0%
Taylor expanded in uy around 0 92.4%
associate-*r*92.4%
Simplified92.4%
Final simplification92.4%
(FPCore (xi yi zi ux uy maxCos) :precision binary32 (fma ux (* (- 1.0 ux) (* maxCos zi)) (* (sqrt (- 1.0 (* ux (* ux (* maxCos maxCos))))) (+ (* (cos (* uy (* 2.0 PI))) xi) (* 2.0 (* uy (* PI yi)))))))
float code(float xi, float yi, float zi, float ux, float uy, float maxCos) {
return fmaf(ux, ((1.0f - ux) * (maxCos * zi)), (sqrtf((1.0f - (ux * (ux * (maxCos * maxCos))))) * ((cosf((uy * (2.0f * ((float) M_PI)))) * xi) + (2.0f * (uy * (((float) M_PI) * yi))))));
}
function code(xi, yi, zi, ux, uy, maxCos) return fma(ux, Float32(Float32(Float32(1.0) - ux) * Float32(maxCos * zi)), Float32(sqrt(Float32(Float32(1.0) - Float32(ux * Float32(ux * Float32(maxCos * maxCos))))) * Float32(Float32(cos(Float32(uy * Float32(Float32(2.0) * Float32(pi)))) * xi) + Float32(Float32(2.0) * Float32(uy * Float32(Float32(pi) * yi)))))) end
\begin{array}{l}
\\
\mathsf{fma}\left(ux, \left(1 - ux\right) \cdot \left(maxCos \cdot zi\right), \sqrt{1 - ux \cdot \left(ux \cdot \left(maxCos \cdot maxCos\right)\right)} \cdot \left(\cos \left(uy \cdot \left(2 \cdot \pi\right)\right) \cdot xi + 2 \cdot \left(uy \cdot \left(\pi \cdot yi\right)\right)\right)\right)
\end{array}
Initial program 99.0%
Simplified99.0%
Taylor expanded in uy around 0 92.4%
Taylor expanded in ux around 0 92.4%
Final simplification92.4%
(FPCore (xi yi zi ux uy maxCos) :precision binary32 (fma ux (* maxCos (* (- 1.0 ux) zi)) (* (sqrt (- 1.0 (* ux (* ux (* maxCos maxCos))))) (+ xi (* 2.0 (* uy (* PI yi)))))))
float code(float xi, float yi, float zi, float ux, float uy, float maxCos) {
return fmaf(ux, (maxCos * ((1.0f - ux) * zi)), (sqrtf((1.0f - (ux * (ux * (maxCos * maxCos))))) * (xi + (2.0f * (uy * (((float) M_PI) * yi))))));
}
function code(xi, yi, zi, ux, uy, maxCos) return fma(ux, Float32(maxCos * Float32(Float32(Float32(1.0) - ux) * zi)), Float32(sqrt(Float32(Float32(1.0) - Float32(ux * Float32(ux * Float32(maxCos * maxCos))))) * Float32(xi + Float32(Float32(2.0) * Float32(uy * Float32(Float32(pi) * yi)))))) end
\begin{array}{l}
\\
\mathsf{fma}\left(ux, maxCos \cdot \left(\left(1 - ux\right) \cdot zi\right), \sqrt{1 - ux \cdot \left(ux \cdot \left(maxCos \cdot maxCos\right)\right)} \cdot \left(xi + 2 \cdot \left(uy \cdot \left(\pi \cdot yi\right)\right)\right)\right)
\end{array}
Initial program 99.0%
Simplified99.0%
Taylor expanded in uy around 0 92.4%
Taylor expanded in ux around 0 92.4%
Taylor expanded in uy around 0 82.7%
Taylor expanded in ux around 0 82.8%
+-commutative82.8%
*-lft-identity82.8%
mul-1-neg82.8%
*-commutative82.8%
associate-*l*82.8%
*-commutative82.8%
distribute-lft-neg-out82.8%
distribute-rgt-in82.7%
sub-neg82.7%
associate-*l*82.8%
Simplified82.8%
Final simplification82.8%
(FPCore (xi yi zi ux uy maxCos) :precision binary32 (fma ux (* maxCos zi) (* (sqrt (- 1.0 (* ux (* ux (* maxCos maxCos))))) (+ xi (* 2.0 (* uy (* PI yi)))))))
float code(float xi, float yi, float zi, float ux, float uy, float maxCos) {
return fmaf(ux, (maxCos * zi), (sqrtf((1.0f - (ux * (ux * (maxCos * maxCos))))) * (xi + (2.0f * (uy * (((float) M_PI) * yi))))));
}
function code(xi, yi, zi, ux, uy, maxCos) return fma(ux, Float32(maxCos * zi), Float32(sqrt(Float32(Float32(1.0) - Float32(ux * Float32(ux * Float32(maxCos * maxCos))))) * Float32(xi + Float32(Float32(2.0) * Float32(uy * Float32(Float32(pi) * yi)))))) end
\begin{array}{l}
\\
\mathsf{fma}\left(ux, maxCos \cdot zi, \sqrt{1 - ux \cdot \left(ux \cdot \left(maxCos \cdot maxCos\right)\right)} \cdot \left(xi + 2 \cdot \left(uy \cdot \left(\pi \cdot yi\right)\right)\right)\right)
\end{array}
Initial program 99.0%
Simplified99.0%
Taylor expanded in uy around 0 92.4%
Taylor expanded in ux around 0 92.4%
Taylor expanded in uy around 0 82.7%
Taylor expanded in ux around 0 79.6%
Final simplification79.6%
herbie shell --seed 2023242
(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)))