
(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 7 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 (* (cos (* (* uy 2.0) PI)) (sqrt (* ux (- (- 2.0 (* ux (pow (+ -1.0 maxCos) 2.0))) (* 2.0 maxCos))))))
float code(float ux, float uy, float maxCos) {
return cosf(((uy * 2.0f) * ((float) M_PI))) * sqrtf((ux * ((2.0f - (ux * powf((-1.0f + maxCos), 2.0f))) - (2.0f * maxCos))));
}
function code(ux, uy, maxCos) return Float32(cos(Float32(Float32(uy * Float32(2.0)) * Float32(pi))) * sqrt(Float32(ux * Float32(Float32(Float32(2.0) - Float32(ux * (Float32(Float32(-1.0) + maxCos) ^ Float32(2.0)))) - Float32(Float32(2.0) * maxCos))))) end
function tmp = code(ux, uy, maxCos) tmp = cos(((uy * single(2.0)) * single(pi))) * sqrt((ux * ((single(2.0) - (ux * ((single(-1.0) + maxCos) ^ single(2.0)))) - (single(2.0) * maxCos)))); end
\begin{array}{l}
\\
\cos \left(\left(uy \cdot 2\right) \cdot \pi\right) \cdot \sqrt{ux \cdot \left(\left(2 - ux \cdot {\left(-1 + maxCos\right)}^{2}\right) - 2 \cdot maxCos\right)}
\end{array}
Initial program 59.5%
Taylor expanded in ux around 0 98.7%
Final simplification98.7%
(FPCore (ux uy maxCos) :precision binary32 (* (cos (* uy (* 2.0 PI))) (sqrt (* ux (+ 2.0 (+ (* maxCos -2.0) (* ux (+ -1.0 (* 2.0 maxCos)))))))))
float code(float ux, float uy, float maxCos) {
return cosf((uy * (2.0f * ((float) M_PI)))) * sqrtf((ux * (2.0f + ((maxCos * -2.0f) + (ux * (-1.0f + (2.0f * maxCos)))))));
}
function code(ux, uy, maxCos) return Float32(cos(Float32(uy * Float32(Float32(2.0) * Float32(pi)))) * sqrt(Float32(ux * Float32(Float32(2.0) + Float32(Float32(maxCos * Float32(-2.0)) + Float32(ux * Float32(Float32(-1.0) + Float32(Float32(2.0) * maxCos)))))))) end
function tmp = code(ux, uy, maxCos) tmp = cos((uy * (single(2.0) * single(pi)))) * sqrt((ux * (single(2.0) + ((maxCos * single(-2.0)) + (ux * (single(-1.0) + (single(2.0) * maxCos))))))); end
\begin{array}{l}
\\
\cos \left(uy \cdot \left(2 \cdot \pi\right)\right) \cdot \sqrt{ux \cdot \left(2 + \left(maxCos \cdot -2 + ux \cdot \left(-1 + 2 \cdot maxCos\right)\right)\right)}
\end{array}
Initial program 59.5%
associate-*l*59.5%
sub-neg59.5%
+-commutative59.5%
distribute-rgt-neg-in59.5%
fma-define59.7%
Simplified59.9%
Taylor expanded in maxCos around 0 59.6%
Taylor expanded in ux around 0 98.5%
Final simplification98.5%
(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(Float32(uy * 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(\left(uy \cdot 2\right) \cdot \pi\right) \cdot \sqrt{ux \cdot \left(2 - ux\right)}
\end{array}
Initial program 59.5%
Taylor expanded in ux around 0 98.7%
Taylor expanded in maxCos around 0 92.4%
neg-mul-192.4%
unsub-neg92.4%
Simplified92.4%
Final simplification92.4%
(FPCore (ux uy maxCos) :precision binary32 (sqrt (- (- (* maxCos (* ux (+ 2.0 (* ux -2.0))))) (* ux (+ ux -2.0)))))
float code(float ux, float uy, float maxCos) {
return sqrtf((-(maxCos * (ux * (2.0f + (ux * -2.0f)))) - (ux * (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((-(maxcos * (ux * (2.0e0 + (ux * (-2.0e0))))) - (ux * (ux + (-2.0e0)))))
end function
function code(ux, uy, maxCos) return sqrt(Float32(Float32(-Float32(maxCos * Float32(ux * Float32(Float32(2.0) + Float32(ux * Float32(-2.0)))))) - Float32(ux * Float32(ux + Float32(-2.0))))) end
function tmp = code(ux, uy, maxCos) tmp = sqrt((-(maxCos * (ux * (single(2.0) + (ux * single(-2.0))))) - (ux * (ux + single(-2.0))))); end
\begin{array}{l}
\\
\sqrt{\left(-maxCos \cdot \left(ux \cdot \left(2 + ux \cdot -2\right)\right)\right) - ux \cdot \left(ux + -2\right)}
\end{array}
Initial program 59.5%
associate-*l*59.5%
sub-neg59.5%
+-commutative59.5%
distribute-rgt-neg-in59.5%
fma-define59.7%
Simplified59.9%
Taylor expanded in uy around 0 47.9%
Simplified47.9%
Taylor expanded in ux around 0 50.0%
Taylor expanded in maxCos around 0 74.3%
mul-1-neg74.3%
*-commutative74.3%
sub-neg74.3%
metadata-eval74.3%
Simplified74.3%
Final simplification74.3%
(FPCore (ux uy maxCos) :precision binary32 (sqrt (* ux (+ 2.0 (+ (* maxCos -2.0) (* ux (+ -1.0 (* 2.0 maxCos))))))))
float code(float ux, float uy, float maxCos) {
return sqrtf((ux * (2.0f + ((maxCos * -2.0f) + (ux * (-1.0f + (2.0f * maxCos)))))));
}
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 + ((maxcos * (-2.0e0)) + (ux * ((-1.0e0) + (2.0e0 * maxcos)))))))
end function
function code(ux, uy, maxCos) return sqrt(Float32(ux * Float32(Float32(2.0) + Float32(Float32(maxCos * Float32(-2.0)) + Float32(ux * Float32(Float32(-1.0) + Float32(Float32(2.0) * maxCos))))))) end
function tmp = code(ux, uy, maxCos) tmp = sqrt((ux * (single(2.0) + ((maxCos * single(-2.0)) + (ux * (single(-1.0) + (single(2.0) * maxCos))))))); end
\begin{array}{l}
\\
\sqrt{ux \cdot \left(2 + \left(maxCos \cdot -2 + ux \cdot \left(-1 + 2 \cdot maxCos\right)\right)\right)}
\end{array}
Initial program 59.5%
associate-*l*59.5%
sub-neg59.5%
+-commutative59.5%
distribute-rgt-neg-in59.5%
fma-define59.7%
Simplified59.9%
Taylor expanded in maxCos around 0 59.6%
Taylor expanded in ux around 0 98.5%
Taylor expanded in uy around 0 74.3%
Final simplification74.3%
(FPCore (ux uy maxCos) :precision binary32 (sqrt (* ux (- (- ux) -2.0))))
float code(float ux, float uy, float maxCos) {
return sqrtf((ux * (-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 * (-ux - (-2.0e0))))
end function
function code(ux, uy, maxCos) return sqrt(Float32(ux * Float32(Float32(-ux) - Float32(-2.0)))) end
function tmp = code(ux, uy, maxCos) tmp = sqrt((ux * (-ux - single(-2.0)))); end
\begin{array}{l}
\\
\sqrt{ux \cdot \left(\left(-ux\right) - -2\right)}
\end{array}
Initial program 59.5%
associate-*l*59.5%
sub-neg59.5%
+-commutative59.5%
distribute-rgt-neg-in59.5%
fma-define59.7%
Simplified59.9%
Taylor expanded in uy around 0 47.9%
Simplified47.9%
Taylor expanded in ux around 0 50.0%
Taylor expanded in maxCos around 0 70.9%
associate-*r*70.9%
mul-1-neg70.9%
sub-neg70.9%
metadata-eval70.9%
Simplified70.9%
Final simplification70.9%
(FPCore (ux uy maxCos) :precision binary32 (sqrt (* 2.0 ux)))
float code(float ux, float uy, float maxCos) {
return sqrtf((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((2.0e0 * ux))
end function
function code(ux, uy, maxCos) return sqrt(Float32(Float32(2.0) * ux)) end
function tmp = code(ux, uy, maxCos) tmp = sqrt((single(2.0) * ux)); end
\begin{array}{l}
\\
\sqrt{2 \cdot ux}
\end{array}
Initial program 59.5%
associate-*l*59.5%
sub-neg59.5%
+-commutative59.5%
distribute-rgt-neg-in59.5%
fma-define59.7%
Simplified59.9%
Taylor expanded in uy around 0 47.9%
Simplified47.9%
Taylor expanded in ux around 0 59.4%
Taylor expanded in maxCos around 0 57.4%
*-commutative57.4%
Simplified57.4%
Final simplification57.4%
herbie shell --seed 2024078
(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)))))))