
(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 6 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 (- (* maxCos (- (* ux (- 2.0 maxCos)) 2.0)) ux))))))
float code(float ux, float uy, float maxCos) {
return cosf(((uy * 2.0f) * ((float) M_PI))) * sqrtf((ux * (2.0f + ((maxCos * ((ux * (2.0f - maxCos)) - 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) + Float32(Float32(maxCos * Float32(Float32(ux * Float32(Float32(2.0) - maxCos)) - Float32(2.0))) - ux))))) end
function tmp = code(ux, uy, maxCos) tmp = cos(((uy * single(2.0)) * single(pi))) * sqrt((ux * (single(2.0) + ((maxCos * ((ux * (single(2.0) - maxCos)) - single(2.0))) - ux)))); end
\begin{array}{l}
\\
\cos \left(\left(uy \cdot 2\right) \cdot \pi\right) \cdot \sqrt{ux \cdot \left(2 + \left(maxCos \cdot \left(ux \cdot \left(2 - maxCos\right) - 2\right) - ux\right)\right)}
\end{array}
Initial program 58.6%
Taylor expanded in ux around 0 98.9%
Taylor expanded in maxCos around 0 99.0%
Taylor expanded in ux around 0 99.0%
neg-mul-199.0%
sub-neg99.0%
Simplified99.0%
Final simplification99.0%
(FPCore (ux uy maxCos)
:precision binary32
(let* ((t_0 (cos (* (* uy 2.0) PI))))
(if (<= t_0 0.9999995231628418)
(* t_0 (sqrt (* ux (- 2.0 ux))))
(sqrt
(* ux (- (- 2.0 (* ux (pow (+ -1.0 maxCos) 2.0))) (* 2.0 maxCos)))))))
float code(float ux, float uy, float maxCos) {
float t_0 = cosf(((uy * 2.0f) * ((float) M_PI)));
float tmp;
if (t_0 <= 0.9999995231628418f) {
tmp = t_0 * sqrtf((ux * (2.0f - ux)));
} else {
tmp = sqrtf((ux * ((2.0f - (ux * powf((-1.0f + maxCos), 2.0f))) - (2.0f * maxCos))));
}
return tmp;
}
function code(ux, uy, maxCos) t_0 = cos(Float32(Float32(uy * Float32(2.0)) * Float32(pi))) tmp = Float32(0.0) if (t_0 <= Float32(0.9999995231628418)) tmp = Float32(t_0 * sqrt(Float32(ux * Float32(Float32(2.0) - ux)))); else tmp = sqrt(Float32(ux * Float32(Float32(Float32(2.0) - Float32(ux * (Float32(Float32(-1.0) + maxCos) ^ Float32(2.0)))) - Float32(Float32(2.0) * maxCos)))); end return tmp end
function tmp_2 = code(ux, uy, maxCos) t_0 = cos(((uy * single(2.0)) * single(pi))); tmp = single(0.0); if (t_0 <= single(0.9999995231628418)) tmp = t_0 * sqrt((ux * (single(2.0) - ux))); else tmp = sqrt((ux * ((single(2.0) - (ux * ((single(-1.0) + maxCos) ^ single(2.0)))) - (single(2.0) * maxCos)))); end tmp_2 = tmp; end
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \cos \left(\left(uy \cdot 2\right) \cdot \pi\right)\\
\mathbf{if}\;t\_0 \leq 0.9999995231628418:\\
\;\;\;\;t\_0 \cdot \sqrt{ux \cdot \left(2 - ux\right)}\\
\mathbf{else}:\\
\;\;\;\;\sqrt{ux \cdot \left(\left(2 - ux \cdot {\left(-1 + maxCos\right)}^{2}\right) - 2 \cdot maxCos\right)}\\
\end{array}
\end{array}
if (cos.f32 (*.f32 (*.f32 uy #s(literal 2 binary32)) (PI.f32))) < 0.999999523Initial program 57.0%
Taylor expanded in ux around 0 98.3%
Taylor expanded in maxCos around 0 92.5%
neg-mul-192.5%
unsub-neg92.5%
Simplified92.5%
if 0.999999523 < (cos.f32 (*.f32 (*.f32 uy #s(literal 2 binary32)) (PI.f32))) Initial program 59.9%
Taylor expanded in ux around 0 99.5%
Taylor expanded in uy around 0 99.2%
Final simplification96.3%
(FPCore (ux uy maxCos) :precision binary32 (* (cos (* (* uy 2.0) PI)) (sqrt (* ux (+ 2.0 (- (* maxCos (- (* 2.0 ux) 2.0)) ux))))))
float code(float ux, float uy, float maxCos) {
return cosf(((uy * 2.0f) * ((float) M_PI))) * sqrtf((ux * (2.0f + ((maxCos * ((2.0f * 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) + Float32(Float32(maxCos * Float32(Float32(Float32(2.0) * ux) - Float32(2.0))) - ux))))) 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(2.0))) - ux)))); end
\begin{array}{l}
\\
\cos \left(\left(uy \cdot 2\right) \cdot \pi\right) \cdot \sqrt{ux \cdot \left(2 + \left(maxCos \cdot \left(2 \cdot ux - 2\right) - ux\right)\right)}
\end{array}
Initial program 58.6%
Taylor expanded in ux around 0 98.9%
Taylor expanded in maxCos around 0 98.8%
Final simplification98.8%
(FPCore (ux uy maxCos)
:precision binary32
(let* ((t_0 (cos (* (* uy 2.0) PI))))
(if (<= maxCos 2.5999999706982635e-5)
(* t_0 (sqrt (* ux (- 2.0 ux))))
(* t_0 (sqrt (* ux (- 2.0 (* 2.0 maxCos))))))))
float code(float ux, float uy, float maxCos) {
float t_0 = cosf(((uy * 2.0f) * ((float) M_PI)));
float tmp;
if (maxCos <= 2.5999999706982635e-5f) {
tmp = t_0 * sqrtf((ux * (2.0f - ux)));
} else {
tmp = t_0 * sqrtf((ux * (2.0f - (2.0f * maxCos))));
}
return tmp;
}
function code(ux, uy, maxCos) t_0 = cos(Float32(Float32(uy * Float32(2.0)) * Float32(pi))) tmp = Float32(0.0) if (maxCos <= Float32(2.5999999706982635e-5)) tmp = Float32(t_0 * sqrt(Float32(ux * Float32(Float32(2.0) - ux)))); else tmp = Float32(t_0 * sqrt(Float32(ux * Float32(Float32(2.0) - Float32(Float32(2.0) * maxCos))))); end return tmp end
function tmp_2 = code(ux, uy, maxCos) t_0 = cos(((uy * single(2.0)) * single(pi))); tmp = single(0.0); if (maxCos <= single(2.5999999706982635e-5)) tmp = t_0 * sqrt((ux * (single(2.0) - ux))); else tmp = t_0 * sqrt((ux * (single(2.0) - (single(2.0) * maxCos)))); end tmp_2 = tmp; end
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \cos \left(\left(uy \cdot 2\right) \cdot \pi\right)\\
\mathbf{if}\;maxCos \leq 2.5999999706982635 \cdot 10^{-5}:\\
\;\;\;\;t\_0 \cdot \sqrt{ux \cdot \left(2 - ux\right)}\\
\mathbf{else}:\\
\;\;\;\;t\_0 \cdot \sqrt{ux \cdot \left(2 - 2 \cdot maxCos\right)}\\
\end{array}
\end{array}
if maxCos < 2.59999997e-5Initial program 61.0%
Taylor expanded in ux around 0 98.9%
Taylor expanded in maxCos around 0 98.1%
neg-mul-198.1%
unsub-neg98.1%
Simplified98.1%
if 2.59999997e-5 < maxCos Initial program 45.6%
Taylor expanded in ux around 0 83.9%
(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 58.6%
Taylor expanded in ux around 0 98.9%
Taylor expanded in maxCos around 0 92.0%
neg-mul-192.0%
unsub-neg92.0%
Simplified92.0%
(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 58.6%
Taylor expanded in ux around 0 98.9%
Taylor expanded in maxCos around 0 92.0%
neg-mul-192.0%
unsub-neg92.0%
Simplified92.0%
add-cbrt-cube92.0%
add-cbrt-cube92.0%
cbrt-unprod92.0%
pow392.0%
*-commutative92.0%
pow392.0%
Applied egg-rr92.0%
Taylor expanded in uy around 0 73.3%
herbie shell --seed 2024111
(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)))))))