
(FPCore (ux uy maxCos) :precision binary32 (let* ((t_0 (+ (- 1.0 ux) (* ux maxCos)))) (* (sin (* (* uy 2.0) PI)) (sqrt (- 1.0 (* t_0 t_0))))))
float code(float ux, float uy, float maxCos) {
float t_0 = (1.0f - ux) + (ux * maxCos);
return sinf(((uy * 2.0f) * ((float) M_PI))) * sqrtf((1.0f - (t_0 * t_0)));
}
function code(ux, uy, maxCos) t_0 = Float32(Float32(Float32(1.0) - ux) + Float32(ux * maxCos)) return Float32(sin(Float32(Float32(uy * Float32(2.0)) * Float32(pi))) * sqrt(Float32(Float32(1.0) - Float32(t_0 * t_0)))) end
function tmp = code(ux, uy, maxCos) t_0 = (single(1.0) - ux) + (ux * maxCos); tmp = sin(((uy * single(2.0)) * single(pi))) * sqrt((single(1.0) - (t_0 * t_0))); end
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \left(1 - ux\right) + ux \cdot maxCos\\
\sin \left(\left(uy \cdot 2\right) \cdot \pi\right) \cdot \sqrt{1 - t_0 \cdot t_0}
\end{array}
\end{array}
Sampling outcomes in binary32 precision:
Herbie found 8 alternatives:
| Alternative | Accuracy | Speedup |
|---|
(FPCore (ux uy maxCos) :precision binary32 (let* ((t_0 (+ (- 1.0 ux) (* ux maxCos)))) (* (sin (* (* uy 2.0) PI)) (sqrt (- 1.0 (* t_0 t_0))))))
float code(float ux, float uy, float maxCos) {
float t_0 = (1.0f - ux) + (ux * maxCos);
return sinf(((uy * 2.0f) * ((float) M_PI))) * sqrtf((1.0f - (t_0 * t_0)));
}
function code(ux, uy, maxCos) t_0 = Float32(Float32(Float32(1.0) - ux) + Float32(ux * maxCos)) return Float32(sin(Float32(Float32(uy * Float32(2.0)) * Float32(pi))) * sqrt(Float32(Float32(1.0) - Float32(t_0 * t_0)))) end
function tmp = code(ux, uy, maxCos) t_0 = (single(1.0) - ux) + (ux * maxCos); tmp = sin(((uy * single(2.0)) * single(pi))) * sqrt((single(1.0) - (t_0 * t_0))); end
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \left(1 - ux\right) + ux \cdot maxCos\\
\sin \left(\left(uy \cdot 2\right) \cdot \pi\right) \cdot \sqrt{1 - t_0 \cdot t_0}
\end{array}
\end{array}
(FPCore (ux uy maxCos) :precision binary32 (* (sin (cbrt (* (pow (* uy 2.0) 3.0) (pow PI 3.0)))) (sqrt (fma (fma maxCos -2.0 2.0) ux (* (pow (- 1.0 maxCos) 2.0) (* ux (- ux)))))))
float code(float ux, float uy, float maxCos) {
return sinf(cbrtf((powf((uy * 2.0f), 3.0f) * powf(((float) M_PI), 3.0f)))) * sqrtf(fmaf(fmaf(maxCos, -2.0f, 2.0f), ux, (powf((1.0f - maxCos), 2.0f) * (ux * -ux))));
}
function code(ux, uy, maxCos) return Float32(sin(cbrt(Float32((Float32(uy * Float32(2.0)) ^ Float32(3.0)) * (Float32(pi) ^ Float32(3.0))))) * sqrt(fma(fma(maxCos, Float32(-2.0), Float32(2.0)), ux, Float32((Float32(Float32(1.0) - maxCos) ^ Float32(2.0)) * Float32(ux * Float32(-ux)))))) end
\begin{array}{l}
\\
\sin \left(\sqrt[3]{{\left(uy \cdot 2\right)}^{3} \cdot {\pi}^{3}}\right) \cdot \sqrt{\mathsf{fma}\left(\mathsf{fma}\left(maxCos, -2, 2\right), ux, {\left(1 - maxCos\right)}^{2} \cdot \left(ux \cdot \left(-ux\right)\right)\right)}
\end{array}
Initial program 55.5%
associate-*l*55.5%
+-commutative55.5%
associate-+r-55.3%
fma-def55.3%
+-commutative55.3%
associate-+r-55.2%
fma-def55.2%
Simplified55.2%
Taylor expanded in ux around -inf 98.5%
metadata-eval98.5%
cancel-sign-sub-inv98.5%
*-commutative98.5%
fma-def98.5%
cancel-sign-sub-inv98.5%
metadata-eval98.5%
+-commutative98.5%
*-commutative98.5%
fma-def98.5%
mul-1-neg98.5%
*-commutative98.5%
distribute-rgt-neg-in98.5%
mul-1-neg98.5%
sub-neg98.5%
unpow298.5%
distribute-rgt-neg-in98.5%
Simplified98.5%
associate-*r*98.5%
add-cbrt-cube98.5%
add-cbrt-cube98.5%
cbrt-unprod98.6%
pow398.6%
pow398.6%
Applied egg-rr98.6%
Final simplification98.6%
(FPCore (ux uy maxCos)
:precision binary32
(let* ((t_0 (sqrt (- (+ 1.0 (- 1.0 maxCos)) maxCos))))
(*
(sin (* uy (* 2.0 PI)))
(sqrt
(fma (+ maxCos -1.0) (* (- 1.0 maxCos) (* ux ux)) (* ux (* t_0 t_0)))))))
float code(float ux, float uy, float maxCos) {
float t_0 = sqrtf(((1.0f + (1.0f - maxCos)) - maxCos));
return sinf((uy * (2.0f * ((float) M_PI)))) * sqrtf(fmaf((maxCos + -1.0f), ((1.0f - maxCos) * (ux * ux)), (ux * (t_0 * t_0))));
}
function code(ux, uy, maxCos) t_0 = sqrt(Float32(Float32(Float32(1.0) + Float32(Float32(1.0) - maxCos)) - maxCos)) return Float32(sin(Float32(uy * Float32(Float32(2.0) * Float32(pi)))) * sqrt(fma(Float32(maxCos + Float32(-1.0)), Float32(Float32(Float32(1.0) - maxCos) * Float32(ux * ux)), Float32(ux * Float32(t_0 * t_0))))) end
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \sqrt{\left(1 + \left(1 - maxCos\right)\right) - maxCos}\\
\sin \left(uy \cdot \left(2 \cdot \pi\right)\right) \cdot \sqrt{\mathsf{fma}\left(maxCos + -1, \left(1 - maxCos\right) \cdot \left(ux \cdot ux\right), ux \cdot \left(t_0 \cdot t_0\right)\right)}
\end{array}
\end{array}
Initial program 55.5%
associate-*l*55.5%
sub-neg55.5%
+-commutative55.5%
distribute-rgt-neg-in55.5%
fma-def55.8%
+-commutative55.8%
associate-+r-55.6%
fma-def55.6%
neg-sub055.6%
+-commutative55.6%
associate-+r-55.4%
associate--r-55.4%
neg-sub055.4%
+-commutative55.4%
sub-neg55.4%
fma-def55.4%
Simplified55.4%
Taylor expanded in ux around 0 98.5%
fma-def98.5%
sub-neg98.5%
metadata-eval98.5%
*-commutative98.5%
unpow298.5%
mul-1-neg98.5%
sub-neg98.5%
metadata-eval98.5%
Simplified98.5%
add-sqr-sqrt98.5%
unsub-neg98.5%
unsub-neg98.5%
Applied egg-rr98.5%
Final simplification98.5%
(FPCore (ux uy maxCos) :precision binary32 (* (sqrt (fma (fma maxCos -2.0 2.0) ux (* (pow (- 1.0 maxCos) 2.0) (* ux (- ux))))) (sin (* uy (* 2.0 PI)))))
float code(float ux, float uy, float maxCos) {
return sqrtf(fmaf(fmaf(maxCos, -2.0f, 2.0f), ux, (powf((1.0f - maxCos), 2.0f) * (ux * -ux)))) * sinf((uy * (2.0f * ((float) M_PI))));
}
function code(ux, uy, maxCos) return Float32(sqrt(fma(fma(maxCos, Float32(-2.0), Float32(2.0)), ux, Float32((Float32(Float32(1.0) - maxCos) ^ Float32(2.0)) * Float32(ux * Float32(-ux))))) * sin(Float32(uy * Float32(Float32(2.0) * Float32(pi))))) end
\begin{array}{l}
\\
\sqrt{\mathsf{fma}\left(\mathsf{fma}\left(maxCos, -2, 2\right), ux, {\left(1 - maxCos\right)}^{2} \cdot \left(ux \cdot \left(-ux\right)\right)\right)} \cdot \sin \left(uy \cdot \left(2 \cdot \pi\right)\right)
\end{array}
Initial program 55.5%
associate-*l*55.5%
+-commutative55.5%
associate-+r-55.3%
fma-def55.3%
+-commutative55.3%
associate-+r-55.2%
fma-def55.2%
Simplified55.2%
Taylor expanded in ux around -inf 98.5%
metadata-eval98.5%
cancel-sign-sub-inv98.5%
*-commutative98.5%
fma-def98.5%
cancel-sign-sub-inv98.5%
metadata-eval98.5%
+-commutative98.5%
*-commutative98.5%
fma-def98.5%
mul-1-neg98.5%
*-commutative98.5%
distribute-rgt-neg-in98.5%
mul-1-neg98.5%
sub-neg98.5%
unpow298.5%
distribute-rgt-neg-in98.5%
Simplified98.5%
Final simplification98.5%
(FPCore (ux uy maxCos)
:precision binary32
(*
(sin (* uy (* 2.0 PI)))
(sqrt
(fma
(+ maxCos -1.0)
(* (- 1.0 maxCos) (* ux ux))
(* ux (+ 2.0 (* maxCos -2.0)))))))
float code(float ux, float uy, float maxCos) {
return sinf((uy * (2.0f * ((float) M_PI)))) * sqrtf(fmaf((maxCos + -1.0f), ((1.0f - maxCos) * (ux * ux)), (ux * (2.0f + (maxCos * -2.0f)))));
}
function code(ux, uy, maxCos) return Float32(sin(Float32(uy * Float32(Float32(2.0) * Float32(pi)))) * sqrt(fma(Float32(maxCos + Float32(-1.0)), Float32(Float32(Float32(1.0) - maxCos) * Float32(ux * ux)), Float32(ux * Float32(Float32(2.0) + Float32(maxCos * Float32(-2.0))))))) end
\begin{array}{l}
\\
\sin \left(uy \cdot \left(2 \cdot \pi\right)\right) \cdot \sqrt{\mathsf{fma}\left(maxCos + -1, \left(1 - maxCos\right) \cdot \left(ux \cdot ux\right), ux \cdot \left(2 + maxCos \cdot -2\right)\right)}
\end{array}
Initial program 55.5%
associate-*l*55.5%
sub-neg55.5%
+-commutative55.5%
distribute-rgt-neg-in55.5%
fma-def55.8%
+-commutative55.8%
associate-+r-55.6%
fma-def55.6%
neg-sub055.6%
+-commutative55.6%
associate-+r-55.4%
associate--r-55.4%
neg-sub055.4%
+-commutative55.4%
sub-neg55.4%
fma-def55.4%
Simplified55.4%
Taylor expanded in ux around 0 98.5%
fma-def98.5%
sub-neg98.5%
metadata-eval98.5%
*-commutative98.5%
unpow298.5%
mul-1-neg98.5%
sub-neg98.5%
metadata-eval98.5%
Simplified98.5%
Taylor expanded in maxCos around 0 98.5%
Final simplification98.5%
(FPCore (ux uy maxCos)
:precision binary32
(let* ((t_0 (* ux (+ ux -1.0))))
(*
(sin (* uy (* 2.0 PI)))
(sqrt (+ (* maxCos (+ t_0 t_0)) (* ux (- 2.0 ux)))))))
float code(float ux, float uy, float maxCos) {
float t_0 = ux * (ux + -1.0f);
return sinf((uy * (2.0f * ((float) M_PI)))) * sqrtf(((maxCos * (t_0 + t_0)) + (ux * (2.0f - ux))));
}
function code(ux, uy, maxCos) t_0 = Float32(ux * Float32(ux + Float32(-1.0))) return Float32(sin(Float32(uy * Float32(Float32(2.0) * Float32(pi)))) * sqrt(Float32(Float32(maxCos * Float32(t_0 + t_0)) + Float32(ux * Float32(Float32(2.0) - ux))))) end
function tmp = code(ux, uy, maxCos) t_0 = ux * (ux + single(-1.0)); tmp = sin((uy * (single(2.0) * single(pi)))) * sqrt(((maxCos * (t_0 + t_0)) + (ux * (single(2.0) - ux)))); end
\begin{array}{l}
\\
\begin{array}{l}
t_0 := ux \cdot \left(ux + -1\right)\\
\sin \left(uy \cdot \left(2 \cdot \pi\right)\right) \cdot \sqrt{maxCos \cdot \left(t_0 + t_0\right) + ux \cdot \left(2 - ux\right)}
\end{array}
\end{array}
Initial program 55.5%
associate-*l*55.5%
sub-neg55.5%
+-commutative55.5%
distribute-rgt-neg-in55.5%
fma-def55.8%
+-commutative55.8%
associate-+r-55.6%
fma-def55.6%
neg-sub055.6%
+-commutative55.6%
associate-+r-55.4%
associate--r-55.4%
neg-sub055.4%
+-commutative55.4%
sub-neg55.4%
fma-def55.4%
Simplified55.4%
Taylor expanded in maxCos around 0 53.5%
Taylor expanded in ux around 0 98.1%
mul-1-neg98.1%
unpow298.1%
distribute-rgt-neg-out98.1%
*-commutative98.1%
distribute-lft-out98.1%
Simplified98.1%
Final simplification98.1%
(FPCore (ux uy maxCos) :precision binary32 (* (sin (* PI (* uy 2.0))) (sqrt (* ux (- 2.0 ux)))))
float code(float ux, float uy, float maxCos) {
return sinf((((float) M_PI) * (uy * 2.0f))) * sqrtf((ux * (2.0f - ux)));
}
function code(ux, uy, maxCos) return Float32(sin(Float32(Float32(pi) * Float32(uy * Float32(2.0)))) * sqrt(Float32(ux * Float32(Float32(2.0) - ux)))) end
function tmp = code(ux, uy, maxCos) tmp = sin((single(pi) * (uy * single(2.0)))) * sqrt((ux * (single(2.0) - ux))); end
\begin{array}{l}
\\
\sin \left(\pi \cdot \left(uy \cdot 2\right)\right) \cdot \sqrt{ux \cdot \left(2 - ux\right)}
\end{array}
Initial program 55.5%
associate-*l*55.5%
+-commutative55.5%
associate-+r-55.3%
fma-def55.3%
+-commutative55.3%
associate-+r-55.2%
fma-def55.2%
Simplified55.2%
Taylor expanded in ux around -inf 98.5%
metadata-eval98.5%
cancel-sign-sub-inv98.5%
*-commutative98.5%
fma-def98.5%
cancel-sign-sub-inv98.5%
metadata-eval98.5%
+-commutative98.5%
*-commutative98.5%
fma-def98.5%
mul-1-neg98.5%
*-commutative98.5%
distribute-rgt-neg-in98.5%
mul-1-neg98.5%
sub-neg98.5%
unpow298.5%
distribute-rgt-neg-in98.5%
Simplified98.5%
Taylor expanded in maxCos around 0 93.4%
associate-*r*93.4%
*-commutative93.4%
*-commutative93.4%
*-commutative93.4%
mul-1-neg93.4%
unpow293.4%
distribute-rgt-neg-out93.4%
*-commutative93.4%
distribute-lft-out93.4%
Simplified93.4%
Final simplification93.4%
(FPCore (ux uy maxCos) :precision binary32 (* 2.0 (* uy (* PI (sqrt (- (* 2.0 ux) (* ux ux)))))))
float code(float ux, float uy, float maxCos) {
return 2.0f * (uy * (((float) M_PI) * sqrtf(((2.0f * ux) - (ux * ux)))));
}
function code(ux, uy, maxCos) return Float32(Float32(2.0) * Float32(uy * Float32(Float32(pi) * sqrt(Float32(Float32(Float32(2.0) * ux) - Float32(ux * ux)))))) end
function tmp = code(ux, uy, maxCos) tmp = single(2.0) * (uy * (single(pi) * sqrt(((single(2.0) * ux) - (ux * ux))))); end
\begin{array}{l}
\\
2 \cdot \left(uy \cdot \left(\pi \cdot \sqrt{2 \cdot ux - ux \cdot ux}\right)\right)
\end{array}
Initial program 55.5%
associate-*l*55.5%
sub-neg55.5%
+-commutative55.5%
distribute-rgt-neg-in55.5%
fma-def55.8%
+-commutative55.8%
associate-+r-55.6%
fma-def55.6%
neg-sub055.6%
+-commutative55.6%
associate-+r-55.4%
associate--r-55.4%
neg-sub055.4%
+-commutative55.4%
sub-neg55.4%
fma-def55.4%
Simplified55.4%
Taylor expanded in uy around 0 48.4%
Taylor expanded in maxCos around 0 47.2%
associate-*l*47.1%
sub-neg47.1%
metadata-eval47.1%
*-commutative47.1%
Simplified47.1%
Taylor expanded in ux around 0 77.7%
+-commutative77.7%
mul-1-neg77.7%
unsub-neg77.7%
unpow277.7%
Simplified77.7%
Final simplification77.7%
(FPCore (ux uy maxCos) :precision binary32 (* 2.0 (* uy (* PI (sqrt (* 2.0 ux))))))
float code(float ux, float uy, float maxCos) {
return 2.0f * (uy * (((float) M_PI) * sqrtf((2.0f * ux))));
}
function code(ux, uy, maxCos) return Float32(Float32(2.0) * Float32(uy * Float32(Float32(pi) * sqrt(Float32(Float32(2.0) * ux))))) end
function tmp = code(ux, uy, maxCos) tmp = single(2.0) * (uy * (single(pi) * sqrt((single(2.0) * ux)))); end
\begin{array}{l}
\\
2 \cdot \left(uy \cdot \left(\pi \cdot \sqrt{2 \cdot ux}\right)\right)
\end{array}
Initial program 55.5%
associate-*l*55.5%
sub-neg55.5%
+-commutative55.5%
distribute-rgt-neg-in55.5%
fma-def55.8%
+-commutative55.8%
associate-+r-55.6%
fma-def55.6%
neg-sub055.6%
+-commutative55.6%
associate-+r-55.4%
associate--r-55.4%
neg-sub055.4%
+-commutative55.4%
sub-neg55.4%
fma-def55.4%
Simplified55.4%
Taylor expanded in uy around 0 48.4%
Taylor expanded in maxCos around 0 47.2%
associate-*l*47.1%
sub-neg47.1%
metadata-eval47.1%
*-commutative47.1%
Simplified47.1%
Taylor expanded in ux around 0 64.8%
Final simplification64.8%
herbie shell --seed 2023258
(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)))))))