
(FPCore (ux uy maxCos) :precision binary32 (let* ((t_0 (+ (- 1.0 ux) (* ux maxCos)))) (* (cos (* (* 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 cosf(((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(cos(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 = cos(((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\\
\cos \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 10 alternatives:
| Alternative | Accuracy | Speedup |
|---|
(FPCore (ux uy maxCos) :precision binary32 (let* ((t_0 (+ (- 1.0 ux) (* ux maxCos)))) (* (cos (* (* 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 cosf(((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(cos(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 = cos(((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\\
\cos \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 (* (pow (* ux (- (fma -2.0 maxCos 2.0) (* ux (pow (+ maxCos -1.0) 2.0)))) 0.5) (cos (* 2.0 (* uy PI)))))
float code(float ux, float uy, float maxCos) {
return powf((ux * (fmaf(-2.0f, maxCos, 2.0f) - (ux * powf((maxCos + -1.0f), 2.0f)))), 0.5f) * cosf((2.0f * (uy * ((float) M_PI))));
}
function code(ux, uy, maxCos) return Float32((Float32(ux * Float32(fma(Float32(-2.0), maxCos, Float32(2.0)) - Float32(ux * (Float32(maxCos + Float32(-1.0)) ^ Float32(2.0))))) ^ Float32(0.5)) * cos(Float32(Float32(2.0) * Float32(uy * Float32(pi))))) end
\begin{array}{l}
\\
{\left(ux \cdot \left(\mathsf{fma}\left(-2, maxCos, 2\right) - ux \cdot {\left(maxCos + -1\right)}^{2}\right)\right)}^{0.5} \cdot \cos \left(2 \cdot \left(uy \cdot \pi\right)\right)
\end{array}
Initial program 52.7%
associate-*l*52.7%
+-commutative52.7%
associate-+r-52.6%
fma-def52.6%
+-commutative52.6%
associate-+r-52.6%
fma-def52.6%
Simplified52.6%
Taylor expanded in ux around 0 98.9%
cancel-sign-sub-inv98.9%
metadata-eval98.9%
+-commutative98.9%
mul-1-neg98.9%
unsub-neg98.9%
*-commutative98.9%
fma-def98.9%
sub-neg98.9%
metadata-eval98.9%
unpow298.9%
Simplified98.9%
Taylor expanded in uy around inf 98.9%
*-commutative98.9%
Simplified99.0%
pow1/299.0%
*-commutative99.0%
Applied egg-rr99.0%
Final simplification99.0%
(FPCore (ux uy maxCos) :precision binary32 (* (cos (* 2.0 (* uy PI))) (sqrt (* ux (- (+ 2.0 (* -2.0 maxCos)) (* ux (pow (+ maxCos -1.0) 2.0)))))))
float code(float ux, float uy, float maxCos) {
return cosf((2.0f * (uy * ((float) M_PI)))) * sqrtf((ux * ((2.0f + (-2.0f * maxCos)) - (ux * powf((maxCos + -1.0f), 2.0f)))));
}
function code(ux, uy, maxCos) return Float32(cos(Float32(Float32(2.0) * Float32(uy * Float32(pi)))) * sqrt(Float32(ux * Float32(Float32(Float32(2.0) + Float32(Float32(-2.0) * maxCos)) - Float32(ux * (Float32(maxCos + Float32(-1.0)) ^ Float32(2.0))))))) end
function tmp = code(ux, uy, maxCos) tmp = cos((single(2.0) * (uy * single(pi)))) * sqrt((ux * ((single(2.0) + (single(-2.0) * maxCos)) - (ux * ((maxCos + single(-1.0)) ^ single(2.0)))))); end
\begin{array}{l}
\\
\cos \left(2 \cdot \left(uy \cdot \pi\right)\right) \cdot \sqrt{ux \cdot \left(\left(2 + -2 \cdot maxCos\right) - ux \cdot {\left(maxCos + -1\right)}^{2}\right)}
\end{array}
Initial program 52.7%
associate-*l*52.7%
+-commutative52.7%
associate-+r-52.6%
fma-def52.6%
+-commutative52.6%
associate-+r-52.6%
fma-def52.6%
Simplified52.6%
Taylor expanded in ux around 0 98.9%
cancel-sign-sub-inv98.9%
metadata-eval98.9%
+-commutative98.9%
mul-1-neg98.9%
unsub-neg98.9%
*-commutative98.9%
fma-def98.9%
sub-neg98.9%
metadata-eval98.9%
unpow298.9%
Simplified98.9%
Taylor expanded in uy around inf 98.9%
*-commutative98.9%
Simplified99.0%
pow1/299.0%
*-commutative99.0%
Applied egg-rr99.0%
Taylor expanded in uy around inf 99.0%
Final simplification99.0%
(FPCore (ux uy maxCos) :precision binary32 (* (cos (* 2.0 (* uy PI))) (sqrt (- (* ux (- 2.0 ux)) (* maxCos (* ux (+ 2.0 (* ux -2.0))))))))
float code(float ux, float uy, float maxCos) {
return cosf((2.0f * (uy * ((float) M_PI)))) * sqrtf(((ux * (2.0f - ux)) - (maxCos * (ux * (2.0f + (ux * -2.0f))))));
}
function code(ux, uy, maxCos) return Float32(cos(Float32(Float32(2.0) * Float32(uy * Float32(pi)))) * sqrt(Float32(Float32(ux * Float32(Float32(2.0) - ux)) - Float32(maxCos * Float32(ux * Float32(Float32(2.0) + Float32(ux * Float32(-2.0)))))))) end
function tmp = code(ux, uy, maxCos) tmp = cos((single(2.0) * (uy * single(pi)))) * sqrt(((ux * (single(2.0) - ux)) - (maxCos * (ux * (single(2.0) + (ux * single(-2.0))))))); end
\begin{array}{l}
\\
\cos \left(2 \cdot \left(uy \cdot \pi\right)\right) \cdot \sqrt{ux \cdot \left(2 - ux\right) - maxCos \cdot \left(ux \cdot \left(2 + ux \cdot -2\right)\right)}
\end{array}
Initial program 52.7%
associate-*l*52.7%
+-commutative52.7%
associate-+r-52.6%
fma-def52.6%
+-commutative52.6%
associate-+r-52.6%
fma-def52.6%
Simplified52.6%
Taylor expanded in ux around 0 98.9%
cancel-sign-sub-inv98.9%
metadata-eval98.9%
+-commutative98.9%
mul-1-neg98.9%
unsub-neg98.9%
*-commutative98.9%
fma-def98.9%
sub-neg98.9%
metadata-eval98.9%
unpow298.9%
Simplified98.9%
Taylor expanded in uy around inf 98.9%
*-commutative98.9%
Simplified99.0%
Taylor expanded in maxCos around 0 98.3%
Final simplification98.3%
(FPCore (ux uy maxCos) :precision binary32 (if (<= maxCos 3.999999989900971e-6) (* (cos (* 2.0 (* uy PI))) (pow (* ux (- 2.0 ux)) 0.5)) (* (cos (* uy (* 2.0 PI))) (sqrt (* ux (- 2.0 (* maxCos 2.0)))))))
float code(float ux, float uy, float maxCos) {
float tmp;
if (maxCos <= 3.999999989900971e-6f) {
tmp = cosf((2.0f * (uy * ((float) M_PI)))) * powf((ux * (2.0f - ux)), 0.5f);
} else {
tmp = cosf((uy * (2.0f * ((float) M_PI)))) * sqrtf((ux * (2.0f - (maxCos * 2.0f))));
}
return tmp;
}
function code(ux, uy, maxCos) tmp = Float32(0.0) if (maxCos <= Float32(3.999999989900971e-6)) tmp = Float32(cos(Float32(Float32(2.0) * Float32(uy * Float32(pi)))) * (Float32(ux * Float32(Float32(2.0) - ux)) ^ Float32(0.5))); else tmp = Float32(cos(Float32(uy * Float32(Float32(2.0) * Float32(pi)))) * sqrt(Float32(ux * Float32(Float32(2.0) - Float32(maxCos * Float32(2.0)))))); end return tmp end
function tmp_2 = code(ux, uy, maxCos) tmp = single(0.0); if (maxCos <= single(3.999999989900971e-6)) tmp = cos((single(2.0) * (uy * single(pi)))) * ((ux * (single(2.0) - ux)) ^ single(0.5)); else tmp = cos((uy * (single(2.0) * single(pi)))) * sqrt((ux * (single(2.0) - (maxCos * single(2.0))))); end tmp_2 = tmp; end
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;maxCos \leq 3.999999989900971 \cdot 10^{-6}:\\
\;\;\;\;\cos \left(2 \cdot \left(uy \cdot \pi\right)\right) \cdot {\left(ux \cdot \left(2 - ux\right)\right)}^{0.5}\\
\mathbf{else}:\\
\;\;\;\;\cos \left(uy \cdot \left(2 \cdot \pi\right)\right) \cdot \sqrt{ux \cdot \left(2 - maxCos \cdot 2\right)}\\
\end{array}
\end{array}
if maxCos < 3.99999999e-6Initial program 53.7%
associate-*l*53.7%
+-commutative53.7%
associate-+r-53.7%
fma-def53.7%
+-commutative53.7%
associate-+r-53.7%
fma-def53.7%
Simplified53.7%
Taylor expanded in ux around 0 98.9%
cancel-sign-sub-inv98.9%
metadata-eval98.9%
+-commutative98.9%
mul-1-neg98.9%
unsub-neg98.9%
*-commutative98.9%
fma-def98.9%
sub-neg98.9%
metadata-eval98.9%
unpow298.9%
Simplified98.9%
Taylor expanded in uy around inf 98.9%
*-commutative98.9%
Simplified98.9%
pow1/298.9%
*-commutative98.9%
Applied egg-rr98.9%
Taylor expanded in maxCos around 0 98.7%
if 3.99999999e-6 < maxCos Initial program 47.3%
associate-*l*47.3%
+-commutative47.3%
associate-+r-46.8%
fma-def46.8%
+-commutative46.8%
associate-+r-46.5%
fma-def46.5%
Simplified46.5%
Taylor expanded in ux around 0 81.5%
Final simplification95.9%
(FPCore (ux uy maxCos) :precision binary32 (* (cos (* 2.0 (* uy PI))) (pow (* ux (- 2.0 ux)) 0.5)))
float code(float ux, float uy, float maxCos) {
return cosf((2.0f * (uy * ((float) M_PI)))) * powf((ux * (2.0f - ux)), 0.5f);
}
function code(ux, uy, maxCos) return Float32(cos(Float32(Float32(2.0) * Float32(uy * Float32(pi)))) * (Float32(ux * Float32(Float32(2.0) - ux)) ^ Float32(0.5))) end
function tmp = code(ux, uy, maxCos) tmp = cos((single(2.0) * (uy * single(pi)))) * ((ux * (single(2.0) - ux)) ^ single(0.5)); end
\begin{array}{l}
\\
\cos \left(2 \cdot \left(uy \cdot \pi\right)\right) \cdot {\left(ux \cdot \left(2 - ux\right)\right)}^{0.5}
\end{array}
Initial program 52.7%
associate-*l*52.7%
+-commutative52.7%
associate-+r-52.6%
fma-def52.6%
+-commutative52.6%
associate-+r-52.6%
fma-def52.6%
Simplified52.6%
Taylor expanded in ux around 0 98.9%
cancel-sign-sub-inv98.9%
metadata-eval98.9%
+-commutative98.9%
mul-1-neg98.9%
unsub-neg98.9%
*-commutative98.9%
fma-def98.9%
sub-neg98.9%
metadata-eval98.9%
unpow298.9%
Simplified98.9%
Taylor expanded in uy around inf 98.9%
*-commutative98.9%
Simplified99.0%
pow1/299.0%
*-commutative99.0%
Applied egg-rr99.0%
Taylor expanded in maxCos around 0 92.5%
Final simplification92.5%
(FPCore (ux uy maxCos) :precision binary32 (* (cos (* uy (* 2.0 PI))) (sqrt (* ux (- 2.0 ux)))))
float code(float ux, float uy, float maxCos) {
return cosf((uy * (2.0f * ((float) M_PI)))) * sqrtf((ux * (2.0f - ux)));
}
function code(ux, uy, maxCos) return Float32(cos(Float32(uy * Float32(Float32(2.0) * Float32(pi)))) * sqrt(Float32(ux * Float32(Float32(2.0) - ux)))) end
function tmp = code(ux, uy, maxCos) tmp = cos((uy * (single(2.0) * single(pi)))) * sqrt((ux * (single(2.0) - ux))); end
\begin{array}{l}
\\
\cos \left(uy \cdot \left(2 \cdot \pi\right)\right) \cdot \sqrt{ux \cdot \left(2 - ux\right)}
\end{array}
Initial program 52.7%
associate-*l*52.7%
+-commutative52.7%
associate-+r-52.6%
fma-def52.6%
+-commutative52.6%
associate-+r-52.6%
fma-def52.6%
Simplified52.6%
Taylor expanded in ux around 0 98.9%
cancel-sign-sub-inv98.9%
metadata-eval98.9%
+-commutative98.9%
mul-1-neg98.9%
unsub-neg98.9%
*-commutative98.9%
fma-def98.9%
sub-neg98.9%
metadata-eval98.9%
unpow298.9%
Simplified98.9%
Taylor expanded in maxCos around 0 92.5%
unpow292.5%
distribute-rgt-out--92.5%
Simplified92.5%
Final simplification92.5%
(FPCore (ux uy maxCos) :precision binary32 (sqrt (* ux (- (+ 2.0 (* -2.0 maxCos)) (* ux (pow (+ maxCos -1.0) 2.0))))))
float code(float ux, float uy, float maxCos) {
return sqrtf((ux * ((2.0f + (-2.0f * maxCos)) - (ux * powf((maxCos + -1.0f), 2.0f)))));
}
real(4) function code(ux, uy, maxcos)
real(4), intent (in) :: ux
real(4), intent (in) :: uy
real(4), intent (in) :: maxcos
code = sqrt((ux * ((2.0e0 + ((-2.0e0) * maxcos)) - (ux * ((maxcos + (-1.0e0)) ** 2.0e0)))))
end function
function code(ux, uy, maxCos) return sqrt(Float32(ux * Float32(Float32(Float32(2.0) + Float32(Float32(-2.0) * maxCos)) - Float32(ux * (Float32(maxCos + Float32(-1.0)) ^ Float32(2.0)))))) end
function tmp = code(ux, uy, maxCos) tmp = sqrt((ux * ((single(2.0) + (single(-2.0) * maxCos)) - (ux * ((maxCos + single(-1.0)) ^ single(2.0)))))); end
\begin{array}{l}
\\
\sqrt{ux \cdot \left(\left(2 + -2 \cdot maxCos\right) - ux \cdot {\left(maxCos + -1\right)}^{2}\right)}
\end{array}
Initial program 52.7%
associate-*l*52.7%
+-commutative52.7%
associate-+r-52.6%
fma-def52.6%
+-commutative52.6%
associate-+r-52.6%
fma-def52.6%
Simplified52.6%
Taylor expanded in ux around 0 98.9%
cancel-sign-sub-inv98.9%
metadata-eval98.9%
+-commutative98.9%
mul-1-neg98.9%
unsub-neg98.9%
*-commutative98.9%
fma-def98.9%
sub-neg98.9%
metadata-eval98.9%
unpow298.9%
Simplified98.9%
Taylor expanded in uy around inf 98.9%
*-commutative98.9%
Simplified99.0%
pow1/299.0%
*-commutative99.0%
Applied egg-rr99.0%
Taylor expanded in uy around 0 76.1%
Final simplification76.1%
(FPCore (ux uy maxCos) :precision binary32 (sqrt (- (* ux (fma -2.0 maxCos 2.0)) (* ux ux))))
float code(float ux, float uy, float maxCos) {
return sqrtf(((ux * fmaf(-2.0f, maxCos, 2.0f)) - (ux * ux)));
}
function code(ux, uy, maxCos) return sqrt(Float32(Float32(ux * fma(Float32(-2.0), maxCos, Float32(2.0))) - Float32(ux * ux))) end
\begin{array}{l}
\\
\sqrt{ux \cdot \mathsf{fma}\left(-2, maxCos, 2\right) - ux \cdot ux}
\end{array}
Initial program 52.7%
associate-*l*52.7%
+-commutative52.7%
associate-+r-52.6%
fma-def52.6%
+-commutative52.6%
associate-+r-52.6%
fma-def52.6%
Simplified52.6%
Taylor expanded in ux around 0 98.9%
cancel-sign-sub-inv98.9%
metadata-eval98.9%
+-commutative98.9%
mul-1-neg98.9%
unsub-neg98.9%
*-commutative98.9%
fma-def98.9%
sub-neg98.9%
metadata-eval98.9%
unpow298.9%
Simplified98.9%
pow1/298.9%
Applied egg-rr98.9%
Taylor expanded in uy around 0 76.1%
*-commutative76.1%
+-commutative76.1%
*-commutative76.1%
fma-def76.1%
sub-neg76.1%
metadata-eval76.1%
*-commutative76.1%
unpow276.1%
Simplified76.1%
Taylor expanded in maxCos around 0 75.2%
unpow275.2%
Simplified75.2%
Final simplification75.2%
(FPCore (ux uy maxCos) :precision binary32 (sqrt (* ux (- 2.0 ux))))
float code(float ux, float uy, float maxCos) {
return sqrtf((ux * (2.0f - ux)));
}
real(4) function code(ux, uy, maxcos)
real(4), intent (in) :: ux
real(4), intent (in) :: uy
real(4), intent (in) :: maxcos
code = sqrt((ux * (2.0e0 - ux)))
end function
function code(ux, uy, maxCos) return sqrt(Float32(ux * Float32(Float32(2.0) - ux))) end
function tmp = code(ux, uy, maxCos) tmp = sqrt((ux * (single(2.0) - ux))); end
\begin{array}{l}
\\
\sqrt{ux \cdot \left(2 - ux\right)}
\end{array}
Initial program 52.7%
associate-*l*52.7%
+-commutative52.7%
associate-+r-52.6%
fma-def52.6%
+-commutative52.6%
associate-+r-52.6%
fma-def52.6%
Simplified52.6%
Taylor expanded in ux around 0 98.9%
cancel-sign-sub-inv98.9%
metadata-eval98.9%
+-commutative98.9%
mul-1-neg98.9%
unsub-neg98.9%
*-commutative98.9%
fma-def98.9%
sub-neg98.9%
metadata-eval98.9%
unpow298.9%
Simplified98.9%
pow1/298.9%
Applied egg-rr98.9%
Taylor expanded in uy around 0 76.1%
*-commutative76.1%
+-commutative76.1%
*-commutative76.1%
fma-def76.1%
sub-neg76.1%
metadata-eval76.1%
*-commutative76.1%
unpow276.1%
Simplified76.1%
Taylor expanded in maxCos around 0 72.5%
unpow272.5%
distribute-rgt-out--72.5%
Simplified72.5%
Final simplification72.5%
(FPCore (ux uy maxCos) :precision binary32 (sqrt (* ux 2.0)))
float code(float ux, float uy, float maxCos) {
return sqrtf((ux * 2.0f));
}
real(4) function code(ux, uy, maxcos)
real(4), intent (in) :: ux
real(4), intent (in) :: uy
real(4), intent (in) :: maxcos
code = sqrt((ux * 2.0e0))
end function
function code(ux, uy, maxCos) return sqrt(Float32(ux * Float32(2.0))) end
function tmp = code(ux, uy, maxCos) tmp = sqrt((ux * single(2.0))); end
\begin{array}{l}
\\
\sqrt{ux \cdot 2}
\end{array}
Initial program 52.7%
associate-*l*52.7%
+-commutative52.7%
associate-+r-52.6%
fma-def52.6%
+-commutative52.6%
associate-+r-52.6%
fma-def52.6%
Simplified52.6%
Taylor expanded in uy around 0 44.6%
Taylor expanded in ux around 0 63.4%
Taylor expanded in maxCos around 0 61.5%
Final simplification61.5%
herbie shell --seed 2023279
(FPCore (ux uy maxCos)
:name "UniformSampleCone, x"
: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)))
(* (cos (* (* uy 2.0) PI)) (sqrt (- 1.0 (* (+ (- 1.0 ux) (* ux maxCos)) (+ (- 1.0 ux) (* ux maxCos)))))))