
(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 9 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
(cbrt
(*
(pow
(* ux (+ 2.0 (fma (- ux) (pow (+ maxCos -1.0) 2.0) (* maxCos -2.0))))
1.5)
(pow (sin (* uy (* 2.0 PI))) 3.0))))
float code(float ux, float uy, float maxCos) {
return cbrtf((powf((ux * (2.0f + fmaf(-ux, powf((maxCos + -1.0f), 2.0f), (maxCos * -2.0f)))), 1.5f) * powf(sinf((uy * (2.0f * ((float) M_PI)))), 3.0f)));
}
function code(ux, uy, maxCos) return cbrt(Float32((Float32(ux * Float32(Float32(2.0) + fma(Float32(-ux), (Float32(maxCos + Float32(-1.0)) ^ Float32(2.0)), Float32(maxCos * Float32(-2.0))))) ^ Float32(1.5)) * (sin(Float32(uy * Float32(Float32(2.0) * Float32(pi)))) ^ Float32(3.0)))) end
\begin{array}{l}
\\
\sqrt[3]{{\left(ux \cdot \left(2 + \mathsf{fma}\left(-ux, {\left(maxCos + -1\right)}^{2}, maxCos \cdot -2\right)\right)\right)}^{1.5} \cdot {\sin \left(uy \cdot \left(2 \cdot \pi\right)\right)}^{3}}
\end{array}
Initial program 56.2%
Taylor expanded in ux around 0 98.4%
associate--l+98.5%
associate-*r*98.5%
mul-1-neg98.5%
fmm-def98.5%
sub-neg98.5%
metadata-eval98.5%
+-commutative98.5%
distribute-lft-neg-in98.5%
metadata-eval98.5%
*-commutative98.5%
Simplified98.5%
*-commutative98.5%
add-cbrt-cube98.4%
*-commutative98.4%
associate-*r*98.4%
add-cbrt-cube98.4%
cbrt-unprod98.5%
Applied egg-rr98.7%
+-commutative98.7%
Simplified98.7%
(FPCore (ux uy maxCos)
:precision binary32
(*
(sin (* uy (* 2.0 PI)))
(sqrt
(*
ux
(-
(+ 1.0 (+ (- 1.0 maxCos) (* ux (* (+ maxCos -1.0) (- 1.0 maxCos)))))
maxCos)))))
float code(float ux, float uy, float maxCos) {
return sinf((uy * (2.0f * ((float) M_PI)))) * sqrtf((ux * ((1.0f + ((1.0f - maxCos) + (ux * ((maxCos + -1.0f) * (1.0f - maxCos))))) - maxCos)));
}
function code(ux, uy, maxCos) return Float32(sin(Float32(uy * Float32(Float32(2.0) * Float32(pi)))) * sqrt(Float32(ux * Float32(Float32(Float32(1.0) + Float32(Float32(Float32(1.0) - maxCos) + Float32(ux * Float32(Float32(maxCos + Float32(-1.0)) * Float32(Float32(1.0) - maxCos))))) - maxCos)))) end
function tmp = code(ux, uy, maxCos) tmp = sin((uy * (single(2.0) * single(pi)))) * sqrt((ux * ((single(1.0) + ((single(1.0) - maxCos) + (ux * ((maxCos + single(-1.0)) * (single(1.0) - maxCos))))) - maxCos))); end
\begin{array}{l}
\\
\sin \left(uy \cdot \left(2 \cdot \pi\right)\right) \cdot \sqrt{ux \cdot \left(\left(1 + \left(\left(1 - maxCos\right) + ux \cdot \left(\left(maxCos + -1\right) \cdot \left(1 - maxCos\right)\right)\right)\right) - maxCos\right)}
\end{array}
Initial program 56.2%
associate-*l*56.2%
sub-neg56.2%
+-commutative56.2%
distribute-rgt-neg-in56.2%
fma-define56.2%
Simplified56.3%
Taylor expanded in ux around inf 98.4%
Taylor expanded in ux around 0 98.4%
sub-neg98.4%
metadata-eval98.4%
distribute-lft-in98.4%
mul-1-neg98.4%
metadata-eval98.4%
+-commutative98.4%
sub-neg98.4%
sub-neg98.4%
metadata-eval98.4%
Simplified98.4%
Final simplification98.4%
(FPCore (ux uy maxCos) :precision binary32 (* (sin (* PI (* 2.0 uy))) (sqrt (* ux (+ 2.0 (- (* maxCos (- (- (* ux 2.0) (* ux maxCos)) 2.0)) ux))))))
float code(float ux, float uy, float maxCos) {
return sinf((((float) M_PI) * (2.0f * uy))) * sqrtf((ux * (2.0f + ((maxCos * (((ux * 2.0f) - (ux * maxCos)) - 2.0f)) - ux))));
}
function code(ux, uy, maxCos) return Float32(sin(Float32(Float32(pi) * Float32(Float32(2.0) * uy))) * sqrt(Float32(ux * Float32(Float32(2.0) + Float32(Float32(maxCos * Float32(Float32(Float32(ux * Float32(2.0)) - Float32(ux * maxCos)) - Float32(2.0))) - ux))))) end
function tmp = code(ux, uy, maxCos) tmp = sin((single(pi) * (single(2.0) * uy))) * sqrt((ux * (single(2.0) + ((maxCos * (((ux * single(2.0)) - (ux * maxCos)) - single(2.0))) - ux)))); end
\begin{array}{l}
\\
\sin \left(\pi \cdot \left(2 \cdot uy\right)\right) \cdot \sqrt{ux \cdot \left(2 + \left(maxCos \cdot \left(\left(ux \cdot 2 - ux \cdot maxCos\right) - 2\right) - ux\right)\right)}
\end{array}
Initial program 56.2%
Taylor expanded in ux around 0 98.4%
associate--l+98.5%
associate-*r*98.5%
mul-1-neg98.5%
fmm-def98.5%
sub-neg98.5%
metadata-eval98.5%
+-commutative98.5%
distribute-lft-neg-in98.5%
metadata-eval98.5%
*-commutative98.5%
Simplified98.5%
Taylor expanded in maxCos around 0 98.5%
Final simplification98.5%
(FPCore (ux uy maxCos) :precision binary32 (* (sin (* PI (* 2.0 uy))) (sqrt (* ux (+ 2.0 (- (* maxCos (- (* ux 2.0) 2.0)) ux))))))
float code(float ux, float uy, float maxCos) {
return sinf((((float) M_PI) * (2.0f * uy))) * sqrtf((ux * (2.0f + ((maxCos * ((ux * 2.0f) - 2.0f)) - ux))));
}
function code(ux, uy, maxCos) return Float32(sin(Float32(Float32(pi) * Float32(Float32(2.0) * uy))) * sqrt(Float32(ux * Float32(Float32(2.0) + Float32(Float32(maxCos * Float32(Float32(ux * Float32(2.0)) - Float32(2.0))) - ux))))) end
function tmp = code(ux, uy, maxCos) tmp = sin((single(pi) * (single(2.0) * uy))) * sqrt((ux * (single(2.0) + ((maxCos * ((ux * single(2.0)) - single(2.0))) - ux)))); end
\begin{array}{l}
\\
\sin \left(\pi \cdot \left(2 \cdot uy\right)\right) \cdot \sqrt{ux \cdot \left(2 + \left(maxCos \cdot \left(ux \cdot 2 - 2\right) - ux\right)\right)}
\end{array}
Initial program 56.2%
Taylor expanded in ux around 0 98.4%
associate--l+98.5%
associate-*r*98.5%
mul-1-neg98.5%
fmm-def98.5%
sub-neg98.5%
metadata-eval98.5%
+-commutative98.5%
distribute-lft-neg-in98.5%
metadata-eval98.5%
*-commutative98.5%
Simplified98.5%
Taylor expanded in maxCos around 0 98.2%
Final simplification98.2%
(FPCore (ux uy maxCos)
:precision binary32
(if (<= (* 2.0 uy) 0.012000000104308128)
(*
2.0
(*
(* ux (* uy PI))
(sqrt
(-
(-
(+ (* (- 1.0 maxCos) (+ maxCos -1.0)) (/ 1.0 ux))
(/ (+ maxCos -1.0) ux))
(/ maxCos ux)))))
(* (sin (* 2.0 (* uy PI))) (sqrt (* ux 2.0)))))
float code(float ux, float uy, float maxCos) {
float tmp;
if ((2.0f * uy) <= 0.012000000104308128f) {
tmp = 2.0f * ((ux * (uy * ((float) M_PI))) * sqrtf((((((1.0f - maxCos) * (maxCos + -1.0f)) + (1.0f / ux)) - ((maxCos + -1.0f) / ux)) - (maxCos / ux))));
} else {
tmp = sinf((2.0f * (uy * ((float) M_PI)))) * sqrtf((ux * 2.0f));
}
return tmp;
}
function code(ux, uy, maxCos) tmp = Float32(0.0) if (Float32(Float32(2.0) * uy) <= Float32(0.012000000104308128)) tmp = Float32(Float32(2.0) * Float32(Float32(ux * Float32(uy * Float32(pi))) * sqrt(Float32(Float32(Float32(Float32(Float32(Float32(1.0) - maxCos) * Float32(maxCos + Float32(-1.0))) + Float32(Float32(1.0) / ux)) - Float32(Float32(maxCos + Float32(-1.0)) / ux)) - Float32(maxCos / ux))))); else tmp = Float32(sin(Float32(Float32(2.0) * Float32(uy * Float32(pi)))) * sqrt(Float32(ux * Float32(2.0)))); end return tmp end
function tmp_2 = code(ux, uy, maxCos) tmp = single(0.0); if ((single(2.0) * uy) <= single(0.012000000104308128)) tmp = single(2.0) * ((ux * (uy * single(pi))) * sqrt((((((single(1.0) - maxCos) * (maxCos + single(-1.0))) + (single(1.0) / ux)) - ((maxCos + single(-1.0)) / ux)) - (maxCos / ux)))); else tmp = sin((single(2.0) * (uy * single(pi)))) * sqrt((ux * single(2.0))); end tmp_2 = tmp; end
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;2 \cdot uy \leq 0.012000000104308128:\\
\;\;\;\;2 \cdot \left(\left(ux \cdot \left(uy \cdot \pi\right)\right) \cdot \sqrt{\left(\left(\left(1 - maxCos\right) \cdot \left(maxCos + -1\right) + \frac{1}{ux}\right) - \frac{maxCos + -1}{ux}\right) - \frac{maxCos}{ux}}\right)\\
\mathbf{else}:\\
\;\;\;\;\sin \left(2 \cdot \left(uy \cdot \pi\right)\right) \cdot \sqrt{ux \cdot 2}\\
\end{array}
\end{array}
if (*.f32 uy #s(literal 2 binary32)) < 0.0120000001Initial program 56.5%
associate-*l*56.5%
sub-neg56.5%
+-commutative56.5%
distribute-rgt-neg-in56.5%
fma-define56.5%
Simplified56.5%
Taylor expanded in ux around inf 98.6%
Taylor expanded in uy around 0 95.2%
if 0.0120000001 < (*.f32 uy #s(literal 2 binary32)) Initial program 55.1%
Taylor expanded in ux around 0 98.0%
associate--l+98.2%
associate-*r*98.2%
mul-1-neg98.2%
fmm-def98.2%
sub-neg98.2%
metadata-eval98.2%
+-commutative98.2%
distribute-lft-neg-in98.2%
metadata-eval98.2%
*-commutative98.2%
Simplified98.2%
Taylor expanded in maxCos around 0 92.5%
neg-mul-192.5%
Simplified92.5%
Taylor expanded in ux around 0 74.0%
Final simplification90.8%
(FPCore (ux uy maxCos) :precision binary32 (* (sqrt (* ux (- 2.0 ux))) (sin (* 2.0 (* uy PI)))))
float code(float ux, float uy, float maxCos) {
return sqrtf((ux * (2.0f - ux))) * sinf((2.0f * (uy * ((float) M_PI))));
}
function code(ux, uy, maxCos) return Float32(sqrt(Float32(ux * Float32(Float32(2.0) - ux))) * sin(Float32(Float32(2.0) * Float32(uy * Float32(pi))))) end
function tmp = code(ux, uy, maxCos) tmp = sqrt((ux * (single(2.0) - ux))) * sin((single(2.0) * (uy * single(pi)))); end
\begin{array}{l}
\\
\sqrt{ux \cdot \left(2 - ux\right)} \cdot \sin \left(2 \cdot \left(uy \cdot \pi\right)\right)
\end{array}
Initial program 56.2%
Taylor expanded in ux around 0 98.4%
associate--l+98.5%
associate-*r*98.5%
mul-1-neg98.5%
fmm-def98.5%
sub-neg98.5%
metadata-eval98.5%
+-commutative98.5%
distribute-lft-neg-in98.5%
metadata-eval98.5%
*-commutative98.5%
Simplified98.5%
Taylor expanded in maxCos around 0 93.5%
neg-mul-193.5%
Simplified93.5%
Taylor expanded in uy around inf 93.5%
(FPCore (ux uy maxCos)
:precision binary32
(*
2.0
(*
(* ux (* uy PI))
(sqrt
(-
(-
(+ (* (- 1.0 maxCos) (+ maxCos -1.0)) (/ 1.0 ux))
(/ (+ maxCos -1.0) ux))
(/ maxCos ux))))))
float code(float ux, float uy, float maxCos) {
return 2.0f * ((ux * (uy * ((float) M_PI))) * sqrtf((((((1.0f - maxCos) * (maxCos + -1.0f)) + (1.0f / ux)) - ((maxCos + -1.0f) / ux)) - (maxCos / ux))));
}
function code(ux, uy, maxCos) return Float32(Float32(2.0) * Float32(Float32(ux * Float32(uy * Float32(pi))) * sqrt(Float32(Float32(Float32(Float32(Float32(Float32(1.0) - maxCos) * Float32(maxCos + Float32(-1.0))) + Float32(Float32(1.0) / ux)) - Float32(Float32(maxCos + Float32(-1.0)) / ux)) - Float32(maxCos / ux))))) end
function tmp = code(ux, uy, maxCos) tmp = single(2.0) * ((ux * (uy * single(pi))) * sqrt((((((single(1.0) - maxCos) * (maxCos + single(-1.0))) + (single(1.0) / ux)) - ((maxCos + single(-1.0)) / ux)) - (maxCos / ux)))); end
\begin{array}{l}
\\
2 \cdot \left(\left(ux \cdot \left(uy \cdot \pi\right)\right) \cdot \sqrt{\left(\left(\left(1 - maxCos\right) \cdot \left(maxCos + -1\right) + \frac{1}{ux}\right) - \frac{maxCos + -1}{ux}\right) - \frac{maxCos}{ux}}\right)
\end{array}
Initial program 56.2%
associate-*l*56.2%
sub-neg56.2%
+-commutative56.2%
distribute-rgt-neg-in56.2%
fma-define56.2%
Simplified56.3%
Taylor expanded in ux around inf 98.4%
Taylor expanded in uy around 0 82.5%
Final simplification82.5%
(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 56.2%
Taylor expanded in ux around 0 98.4%
associate--l+98.5%
associate-*r*98.5%
mul-1-neg98.5%
fmm-def98.5%
sub-neg98.5%
metadata-eval98.5%
+-commutative98.5%
distribute-lft-neg-in98.5%
metadata-eval98.5%
*-commutative98.5%
Simplified98.5%
Taylor expanded in maxCos around 0 93.5%
neg-mul-193.5%
Simplified93.5%
Taylor expanded in uy around 0 79.4%
associate-*r*79.4%
Simplified79.4%
Final simplification79.4%
(FPCore (ux uy maxCos) :precision binary32 0.0)
float code(float ux, float uy, float maxCos) {
return 0.0f;
}
real(4) function code(ux, uy, maxcos)
real(4), intent (in) :: ux
real(4), intent (in) :: uy
real(4), intent (in) :: maxcos
code = 0.0e0
end function
function code(ux, uy, maxCos) return Float32(0.0) end
function tmp = code(ux, uy, maxCos) tmp = single(0.0); end
\begin{array}{l}
\\
0
\end{array}
Initial program 56.2%
associate-*l*56.2%
sub-neg56.2%
+-commutative56.2%
distribute-rgt-neg-in56.2%
fma-define56.2%
Simplified56.3%
Taylor expanded in uy around 0 48.9%
Simplified49.0%
Taylor expanded in ux around 0 7.2%
Taylor expanded in uy around 0 7.2%
herbie shell --seed 2024132
(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)))))))