
(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 ux (fma maxCos -2.0 2.0) (* (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(ux, fmaf(maxCos, -2.0f, 2.0f), (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(ux, fma(maxCos, Float32(-2.0), Float32(2.0)), 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(ux, \mathsf{fma}\left(maxCos, -2, 2\right), {\left(1 - maxCos\right)}^{2} \cdot \left(ux \cdot \left(-ux\right)\right)\right)}
\end{array}
Initial program 52.8%
associate-*l*52.8%
+-commutative52.8%
associate-+r-52.8%
fma-def52.8%
+-commutative52.8%
associate-+r-52.7%
fma-def52.7%
Simplified52.7%
Taylor expanded in ux around -inf 98.3%
+-commutative98.3%
metadata-eval98.3%
cancel-sign-sub-inv98.3%
fma-def98.4%
cancel-sign-sub-inv98.4%
metadata-eval98.4%
+-commutative98.4%
*-commutative98.4%
fma-def98.4%
mul-1-neg98.4%
*-commutative98.4%
distribute-rgt-neg-in98.4%
mul-1-neg98.4%
unsub-neg98.4%
unpow298.4%
distribute-rgt-neg-in98.4%
Simplified98.4%
associate-*r*98.4%
add-cbrt-cube98.4%
add-cbrt-cube98.4%
cbrt-unprod98.5%
pow398.5%
pow398.5%
Applied egg-rr98.5%
Final simplification98.5%
(FPCore (ux uy maxCos) :precision binary32 (* (sqrt (* ux (- (fma maxCos -2.0 2.0) (* ux (pow (- 1.0 maxCos) 2.0))))) (sin (* PI (* uy 2.0)))))
float code(float ux, float uy, float maxCos) {
return sqrtf((ux * (fmaf(maxCos, -2.0f, 2.0f) - (ux * powf((1.0f - maxCos), 2.0f))))) * sinf((((float) M_PI) * (uy * 2.0f)));
}
function code(ux, uy, maxCos) return Float32(sqrt(Float32(ux * Float32(fma(maxCos, Float32(-2.0), Float32(2.0)) - Float32(ux * (Float32(Float32(1.0) - maxCos) ^ Float32(2.0)))))) * sin(Float32(Float32(pi) * Float32(uy * Float32(2.0))))) end
\begin{array}{l}
\\
\sqrt{ux \cdot \left(\mathsf{fma}\left(maxCos, -2, 2\right) - ux \cdot {\left(1 - maxCos\right)}^{2}\right)} \cdot \sin \left(\pi \cdot \left(uy \cdot 2\right)\right)
\end{array}
Initial program 52.8%
associate-*l*52.8%
+-commutative52.8%
associate-+r-52.8%
fma-def52.8%
+-commutative52.8%
associate-+r-52.7%
fma-def52.7%
Simplified52.7%
Taylor expanded in ux around -inf 98.3%
+-commutative98.3%
metadata-eval98.3%
cancel-sign-sub-inv98.3%
fma-def98.4%
cancel-sign-sub-inv98.4%
metadata-eval98.4%
+-commutative98.4%
*-commutative98.4%
fma-def98.4%
mul-1-neg98.4%
*-commutative98.4%
distribute-rgt-neg-in98.4%
mul-1-neg98.4%
unsub-neg98.4%
unpow298.4%
distribute-rgt-neg-in98.4%
Simplified98.4%
associate-*r*98.4%
add-cbrt-cube98.4%
add-cbrt-cube98.4%
cbrt-unprod98.5%
pow398.5%
pow398.5%
Applied egg-rr98.5%
Taylor expanded in uy around inf 98.3%
*-commutative98.3%
Simplified98.3%
*-un-lft-identity98.3%
*-commutative98.3%
Applied egg-rr98.3%
*-lft-identity98.3%
distribute-lft-out--98.4%
Simplified98.4%
Final simplification98.4%
(FPCore (ux uy maxCos)
:precision binary32
(let* ((t_0 (- (* 2.0 ux) (* ux ux))))
(*
(sin (* PI (* uy 2.0)))
(+
(* 0.5 (* (sqrt (/ 1.0 t_0)) (* maxCos (* -2.0 (- ux (* ux ux))))))
(sqrt t_0)))))
float code(float ux, float uy, float maxCos) {
float t_0 = (2.0f * ux) - (ux * ux);
return sinf((((float) M_PI) * (uy * 2.0f))) * ((0.5f * (sqrtf((1.0f / t_0)) * (maxCos * (-2.0f * (ux - (ux * ux)))))) + sqrtf(t_0));
}
function code(ux, uy, maxCos) t_0 = Float32(Float32(Float32(2.0) * ux) - Float32(ux * ux)) return Float32(sin(Float32(Float32(pi) * Float32(uy * Float32(2.0)))) * Float32(Float32(Float32(0.5) * Float32(sqrt(Float32(Float32(1.0) / t_0)) * Float32(maxCos * Float32(Float32(-2.0) * Float32(ux - Float32(ux * ux)))))) + sqrt(t_0))) end
function tmp = code(ux, uy, maxCos) t_0 = (single(2.0) * ux) - (ux * ux); tmp = sin((single(pi) * (uy * single(2.0)))) * ((single(0.5) * (sqrt((single(1.0) / t_0)) * (maxCos * (single(-2.0) * (ux - (ux * ux)))))) + sqrt(t_0)); end
\begin{array}{l}
\\
\begin{array}{l}
t_0 := 2 \cdot ux - ux \cdot ux\\
\sin \left(\pi \cdot \left(uy \cdot 2\right)\right) \cdot \left(0.5 \cdot \left(\sqrt{\frac{1}{t_0}} \cdot \left(maxCos \cdot \left(-2 \cdot \left(ux - ux \cdot ux\right)\right)\right)\right) + \sqrt{t_0}\right)
\end{array}
\end{array}
Initial program 52.8%
associate-*l*52.8%
+-commutative52.8%
associate-+r-52.8%
fma-def52.8%
+-commutative52.8%
associate-+r-52.7%
fma-def52.7%
Simplified52.7%
Taylor expanded in ux around -inf 98.3%
+-commutative98.3%
metadata-eval98.3%
cancel-sign-sub-inv98.3%
fma-def98.4%
cancel-sign-sub-inv98.4%
metadata-eval98.4%
+-commutative98.4%
*-commutative98.4%
fma-def98.4%
mul-1-neg98.4%
*-commutative98.4%
distribute-rgt-neg-in98.4%
mul-1-neg98.4%
unsub-neg98.4%
unpow298.4%
distribute-rgt-neg-in98.4%
Simplified98.4%
associate-*r*98.4%
add-cbrt-cube98.4%
add-cbrt-cube98.4%
cbrt-unprod98.5%
pow398.5%
pow398.5%
Applied egg-rr98.5%
Taylor expanded in uy around inf 98.3%
*-commutative98.3%
Simplified98.3%
Taylor expanded in maxCos around 0 96.0%
+-commutative96.0%
*-commutative96.0%
unpow296.0%
distribute-lft-out--96.0%
unpow296.0%
unpow296.0%
Simplified96.0%
Final simplification96.0%
(FPCore (ux uy maxCos) :precision binary32 (if (<= maxCos 3.999999989900971e-6) (* (sin (* PI (* uy 2.0))) (sqrt (* ux (- 2.0 ux)))) (* (sin (* uy (* 2.0 PI))) (sqrt (* ux (- 2.0 (* 2.0 maxCos)))))))
float code(float ux, float uy, float maxCos) {
float tmp;
if (maxCos <= 3.999999989900971e-6f) {
tmp = sinf((((float) M_PI) * (uy * 2.0f))) * sqrtf((ux * (2.0f - ux)));
} else {
tmp = sinf((uy * (2.0f * ((float) M_PI)))) * sqrtf((ux * (2.0f - (2.0f * maxCos))));
}
return tmp;
}
function code(ux, uy, maxCos) tmp = Float32(0.0) if (maxCos <= Float32(3.999999989900971e-6)) tmp = Float32(sin(Float32(Float32(pi) * Float32(uy * Float32(2.0)))) * sqrt(Float32(ux * Float32(Float32(2.0) - ux)))); else tmp = Float32(sin(Float32(uy * Float32(Float32(2.0) * Float32(pi)))) * sqrt(Float32(ux * Float32(Float32(2.0) - Float32(Float32(2.0) * maxCos))))); end return tmp end
function tmp_2 = code(ux, uy, maxCos) tmp = single(0.0); if (maxCos <= single(3.999999989900971e-6)) tmp = sin((single(pi) * (uy * single(2.0)))) * sqrt((ux * (single(2.0) - ux))); else tmp = sin((uy * (single(2.0) * single(pi)))) * sqrt((ux * (single(2.0) - (single(2.0) * maxCos)))); end tmp_2 = tmp; end
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;maxCos \leq 3.999999989900971 \cdot 10^{-6}:\\
\;\;\;\;\sin \left(\pi \cdot \left(uy \cdot 2\right)\right) \cdot \sqrt{ux \cdot \left(2 - ux\right)}\\
\mathbf{else}:\\
\;\;\;\;\sin \left(uy \cdot \left(2 \cdot \pi\right)\right) \cdot \sqrt{ux \cdot \left(2 - 2 \cdot maxCos\right)}\\
\end{array}
\end{array}
if maxCos < 3.99999999e-6Initial program 53.9%
associate-*l*53.9%
+-commutative53.9%
associate-+r-53.9%
fma-def53.9%
+-commutative53.9%
associate-+r-53.9%
fma-def53.9%
Simplified53.9%
Taylor expanded in ux around -inf 98.4%
+-commutative98.4%
metadata-eval98.4%
cancel-sign-sub-inv98.4%
fma-def98.4%
cancel-sign-sub-inv98.4%
metadata-eval98.4%
+-commutative98.4%
*-commutative98.4%
fma-def98.4%
mul-1-neg98.4%
*-commutative98.4%
distribute-rgt-neg-in98.4%
mul-1-neg98.4%
unsub-neg98.4%
unpow298.4%
distribute-rgt-neg-in98.4%
Simplified98.4%
associate-*r*98.4%
add-cbrt-cube98.4%
add-cbrt-cube98.4%
cbrt-unprod98.5%
pow398.6%
pow398.6%
Applied egg-rr98.6%
Taylor expanded in maxCos around 0 98.1%
*-commutative98.1%
associate-*r*98.1%
*-commutative98.1%
associate-*l*98.1%
+-commutative98.1%
*-commutative98.1%
mul-1-neg98.1%
unpow298.1%
distribute-rgt-neg-out98.1%
distribute-lft-out98.1%
unsub-neg98.1%
Simplified98.1%
if 3.99999999e-6 < maxCos Initial program 47.2%
associate-*l*47.2%
+-commutative47.2%
associate-+r-46.7%
fma-def46.7%
+-commutative46.7%
associate-+r-46.3%
fma-def46.3%
Simplified46.3%
Taylor expanded in ux around 0 81.5%
Final simplification95.5%
(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 52.8%
associate-*l*52.8%
+-commutative52.8%
associate-+r-52.8%
fma-def52.8%
+-commutative52.8%
associate-+r-52.7%
fma-def52.7%
Simplified52.7%
Taylor expanded in ux around -inf 98.3%
+-commutative98.3%
metadata-eval98.3%
cancel-sign-sub-inv98.3%
fma-def98.4%
cancel-sign-sub-inv98.4%
metadata-eval98.4%
+-commutative98.4%
*-commutative98.4%
fma-def98.4%
mul-1-neg98.4%
*-commutative98.4%
distribute-rgt-neg-in98.4%
mul-1-neg98.4%
unsub-neg98.4%
unpow298.4%
distribute-rgt-neg-in98.4%
Simplified98.4%
associate-*r*98.4%
add-cbrt-cube98.4%
add-cbrt-cube98.4%
cbrt-unprod98.5%
pow398.5%
pow398.5%
Applied egg-rr98.5%
Taylor expanded in maxCos around 0 92.0%
*-commutative92.0%
associate-*r*92.0%
*-commutative92.0%
associate-*l*92.0%
+-commutative92.0%
*-commutative92.0%
mul-1-neg92.0%
unpow292.0%
distribute-rgt-neg-out92.0%
distribute-lft-out92.1%
unsub-neg92.1%
Simplified92.1%
Final simplification92.1%
(FPCore (ux uy maxCos) :precision binary32 (* uy (* 2.0 (* PI (sqrt (* ux (- 2.0 ux)))))))
float code(float ux, float uy, float maxCos) {
return uy * (2.0f * (((float) M_PI) * sqrtf((ux * (2.0f - ux)))));
}
function code(ux, uy, maxCos) return Float32(uy * Float32(Float32(2.0) * Float32(Float32(pi) * sqrt(Float32(ux * Float32(Float32(2.0) - ux)))))) end
function tmp = code(ux, uy, maxCos) tmp = uy * (single(2.0) * (single(pi) * sqrt((ux * (single(2.0) - ux))))); end
\begin{array}{l}
\\
uy \cdot \left(2 \cdot \left(\pi \cdot \sqrt{ux \cdot \left(2 - ux\right)}\right)\right)
\end{array}
Initial program 52.8%
associate-*l*52.8%
+-commutative52.8%
associate-+r-52.8%
fma-def52.8%
+-commutative52.8%
associate-+r-52.7%
fma-def52.7%
Simplified52.7%
Taylor expanded in ux around -inf 98.3%
+-commutative98.3%
metadata-eval98.3%
cancel-sign-sub-inv98.3%
fma-def98.4%
cancel-sign-sub-inv98.4%
metadata-eval98.4%
+-commutative98.4%
*-commutative98.4%
fma-def98.4%
mul-1-neg98.4%
*-commutative98.4%
distribute-rgt-neg-in98.4%
mul-1-neg98.4%
unsub-neg98.4%
unpow298.4%
distribute-rgt-neg-in98.4%
Simplified98.4%
Taylor expanded in maxCos around 0 92.0%
fma-def92.0%
unpow292.0%
Simplified92.0%
Taylor expanded in uy around 0 74.4%
*-commutative74.4%
associate-*l*74.4%
associate-*l*74.4%
+-commutative74.4%
*-commutative74.4%
mul-1-neg74.4%
unpow274.4%
distribute-rgt-neg-out74.4%
distribute-lft-out74.4%
unsub-neg74.4%
Simplified74.4%
Final simplification74.4%
(FPCore (ux uy maxCos) :precision binary32 (* (* uy PI) (* 2.0 (sqrt (* ux (- 2.0 ux))))))
float code(float ux, float uy, float maxCos) {
return (uy * ((float) M_PI)) * (2.0f * sqrtf((ux * (2.0f - ux))));
}
function code(ux, uy, maxCos) return Float32(Float32(uy * Float32(pi)) * Float32(Float32(2.0) * sqrt(Float32(ux * Float32(Float32(2.0) - ux))))) end
function tmp = code(ux, uy, maxCos) tmp = (uy * single(pi)) * (single(2.0) * sqrt((ux * (single(2.0) - ux)))); end
\begin{array}{l}
\\
\left(uy \cdot \pi\right) \cdot \left(2 \cdot \sqrt{ux \cdot \left(2 - ux\right)}\right)
\end{array}
Initial program 52.8%
associate-*l*52.8%
+-commutative52.8%
associate-+r-52.8%
fma-def52.8%
+-commutative52.8%
associate-+r-52.7%
fma-def52.7%
Simplified52.7%
Taylor expanded in ux around -inf 98.3%
+-commutative98.3%
metadata-eval98.3%
cancel-sign-sub-inv98.3%
fma-def98.4%
cancel-sign-sub-inv98.4%
metadata-eval98.4%
+-commutative98.4%
*-commutative98.4%
fma-def98.4%
mul-1-neg98.4%
*-commutative98.4%
distribute-rgt-neg-in98.4%
mul-1-neg98.4%
unsub-neg98.4%
unpow298.4%
distribute-rgt-neg-in98.4%
Simplified98.4%
Taylor expanded in maxCos around 0 92.0%
fma-def92.0%
unpow292.0%
Simplified92.0%
Taylor expanded in uy around 0 74.4%
*-commutative74.4%
associate-*l*74.4%
associate-*l*74.4%
+-commutative74.4%
*-commutative74.4%
mul-1-neg74.4%
unpow274.4%
distribute-rgt-neg-out74.4%
distribute-lft-out74.4%
unsub-neg74.4%
Simplified74.4%
Taylor expanded in uy around 0 74.4%
associate-*r*74.4%
*-commutative74.4%
Simplified74.4%
Final simplification74.4%
(FPCore (ux uy maxCos) :precision binary32 (* uy (* 2.0 (* PI (sqrt (* 2.0 ux))))))
float code(float ux, float uy, float maxCos) {
return uy * (2.0f * (((float) M_PI) * sqrtf((2.0f * ux))));
}
function code(ux, uy, maxCos) return Float32(uy * Float32(Float32(2.0) * Float32(Float32(pi) * sqrt(Float32(Float32(2.0) * ux))))) end
function tmp = code(ux, uy, maxCos) tmp = uy * (single(2.0) * (single(pi) * sqrt((single(2.0) * ux)))); end
\begin{array}{l}
\\
uy \cdot \left(2 \cdot \left(\pi \cdot \sqrt{2 \cdot ux}\right)\right)
\end{array}
Initial program 52.8%
associate-*l*52.8%
+-commutative52.8%
associate-+r-52.8%
fma-def52.8%
+-commutative52.8%
associate-+r-52.7%
fma-def52.7%
Simplified52.7%
Taylor expanded in ux around -inf 98.3%
+-commutative98.3%
metadata-eval98.3%
cancel-sign-sub-inv98.3%
fma-def98.4%
cancel-sign-sub-inv98.4%
metadata-eval98.4%
+-commutative98.4%
*-commutative98.4%
fma-def98.4%
mul-1-neg98.4%
*-commutative98.4%
distribute-rgt-neg-in98.4%
mul-1-neg98.4%
unsub-neg98.4%
unpow298.4%
distribute-rgt-neg-in98.4%
Simplified98.4%
Taylor expanded in maxCos around 0 92.0%
fma-def92.0%
unpow292.0%
Simplified92.0%
Taylor expanded in uy around 0 74.4%
*-commutative74.4%
associate-*l*74.4%
associate-*l*74.4%
+-commutative74.4%
*-commutative74.4%
mul-1-neg74.4%
unpow274.4%
distribute-rgt-neg-out74.4%
distribute-lft-out74.4%
unsub-neg74.4%
Simplified74.4%
Taylor expanded in ux around 0 63.4%
Final simplification63.4%
herbie shell --seed 2023279
(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)))))))