
(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 9 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 (fma (- ux) (pow (+ -1.0 maxCos) 2.0) (* maxCos -2.0)))))))
float code(float ux, float uy, float maxCos) {
return cosf(((uy * 2.0f) * ((float) M_PI))) * sqrtf((ux * (2.0f + fmaf(-ux, powf((-1.0f + maxCos), 2.0f), (maxCos * -2.0f)))));
}
function code(ux, uy, maxCos) return Float32(cos(Float32(Float32(uy * Float32(2.0)) * Float32(pi))) * sqrt(Float32(ux * Float32(Float32(2.0) + fma(Float32(-ux), (Float32(Float32(-1.0) + maxCos) ^ Float32(2.0)), Float32(maxCos * Float32(-2.0))))))) end
\begin{array}{l}
\\
\cos \left(\left(uy \cdot 2\right) \cdot \pi\right) \cdot \sqrt{ux \cdot \left(2 + \mathsf{fma}\left(-ux, {\left(-1 + maxCos\right)}^{2}, maxCos \cdot -2\right)\right)}
\end{array}
Initial program 57.6%
Taylor expanded in ux around 0 98.8%
associate--l+98.8%
associate-*r*98.8%
mul-1-neg98.8%
fma-neg98.8%
sub-neg98.8%
metadata-eval98.8%
+-commutative98.8%
distribute-lft-neg-in98.8%
metadata-eval98.8%
*-commutative98.8%
Simplified98.8%
Final simplification98.8%
(FPCore (ux uy maxCos) :precision binary32 (* (cos (* (* uy 2.0) PI)) (sqrt (* ux (+ (* maxCos -2.0) (- 2.0 (* ux (pow (+ -1.0 maxCos) 2.0))))))))
float code(float ux, float uy, float maxCos) {
return cosf(((uy * 2.0f) * ((float) M_PI))) * sqrtf((ux * ((maxCos * -2.0f) + (2.0f - (ux * powf((-1.0f + maxCos), 2.0f))))));
}
function code(ux, uy, maxCos) return Float32(cos(Float32(Float32(uy * Float32(2.0)) * Float32(pi))) * sqrt(Float32(ux * Float32(Float32(maxCos * Float32(-2.0)) + Float32(Float32(2.0) - Float32(ux * (Float32(Float32(-1.0) + maxCos) ^ Float32(2.0)))))))) end
function tmp = code(ux, uy, maxCos) tmp = cos(((uy * single(2.0)) * single(pi))) * sqrt((ux * ((maxCos * single(-2.0)) + (single(2.0) - (ux * ((single(-1.0) + maxCos) ^ single(2.0))))))); end
\begin{array}{l}
\\
\cos \left(\left(uy \cdot 2\right) \cdot \pi\right) \cdot \sqrt{ux \cdot \left(maxCos \cdot -2 + \left(2 - ux \cdot {\left(-1 + maxCos\right)}^{2}\right)\right)}
\end{array}
Initial program 57.6%
Taylor expanded in ux around 0 98.8%
cancel-sign-sub-inv98.8%
associate-*r*98.8%
mul-1-neg98.8%
sub-neg98.8%
metadata-eval98.8%
+-commutative98.8%
metadata-eval98.8%
*-commutative98.8%
Simplified98.8%
Final simplification98.8%
(FPCore (ux uy maxCos)
:precision binary32
(*
(cos (* uy (* 2.0 PI)))
(sqrt
(*
ux
(+ (- 1.0 maxCos) (* (+ -1.0 (* ux (- 1.0 maxCos))) (+ -1.0 maxCos)))))))
float code(float ux, float uy, float maxCos) {
return cosf((uy * (2.0f * ((float) M_PI)))) * sqrtf((ux * ((1.0f - maxCos) + ((-1.0f + (ux * (1.0f - maxCos))) * (-1.0f + maxCos)))));
}
function code(ux, uy, maxCos) return Float32(cos(Float32(uy * Float32(Float32(2.0) * Float32(pi)))) * sqrt(Float32(ux * Float32(Float32(Float32(1.0) - maxCos) + Float32(Float32(Float32(-1.0) + Float32(ux * Float32(Float32(1.0) - maxCos))) * Float32(Float32(-1.0) + maxCos)))))) end
function tmp = code(ux, uy, maxCos) tmp = cos((uy * (single(2.0) * single(pi)))) * sqrt((ux * ((single(1.0) - maxCos) + ((single(-1.0) + (ux * (single(1.0) - maxCos))) * (single(-1.0) + maxCos))))); end
\begin{array}{l}
\\
\cos \left(uy \cdot \left(2 \cdot \pi\right)\right) \cdot \sqrt{ux \cdot \left(\left(1 - maxCos\right) + \left(-1 + ux \cdot \left(1 - maxCos\right)\right) \cdot \left(-1 + maxCos\right)\right)}
\end{array}
Initial program 57.6%
associate-*l*57.6%
sub-neg57.6%
+-commutative57.6%
distribute-rgt-neg-in57.6%
fma-define57.6%
Simplified57.6%
Taylor expanded in ux around inf 98.7%
Taylor expanded in ux around 0 98.7%
+-commutative98.7%
associate--l+98.8%
associate-*r*98.8%
distribute-rgt-out98.8%
sub-neg98.8%
metadata-eval98.8%
+-commutative98.8%
Simplified98.8%
Final simplification98.8%
(FPCore (ux uy maxCos) :precision binary32 (if (<= (* uy 2.0) 0.00013099999341648072) (sqrt (* ux (+ 2.0 (- (* maxCos -2.0) (* ux (pow (+ -1.0 maxCos) 2.0)))))) (* (cos (* (* uy 2.0) PI)) (sqrt (* ux (- 2.0 ux))))))
float code(float ux, float uy, float maxCos) {
float tmp;
if ((uy * 2.0f) <= 0.00013099999341648072f) {
tmp = sqrtf((ux * (2.0f + ((maxCos * -2.0f) - (ux * powf((-1.0f + maxCos), 2.0f))))));
} else {
tmp = cosf(((uy * 2.0f) * ((float) M_PI))) * sqrtf((ux * (2.0f - ux)));
}
return tmp;
}
function code(ux, uy, maxCos) tmp = Float32(0.0) if (Float32(uy * Float32(2.0)) <= Float32(0.00013099999341648072)) tmp = sqrt(Float32(ux * Float32(Float32(2.0) + Float32(Float32(maxCos * Float32(-2.0)) - Float32(ux * (Float32(Float32(-1.0) + maxCos) ^ Float32(2.0))))))); else tmp = Float32(cos(Float32(Float32(uy * Float32(2.0)) * Float32(pi))) * sqrt(Float32(ux * Float32(Float32(2.0) - ux)))); end return tmp end
function tmp_2 = code(ux, uy, maxCos) tmp = single(0.0); if ((uy * single(2.0)) <= single(0.00013099999341648072)) tmp = sqrt((ux * (single(2.0) + ((maxCos * single(-2.0)) - (ux * ((single(-1.0) + maxCos) ^ single(2.0))))))); else tmp = cos(((uy * single(2.0)) * single(pi))) * sqrt((ux * (single(2.0) - ux))); end tmp_2 = tmp; end
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;uy \cdot 2 \leq 0.00013099999341648072:\\
\;\;\;\;\sqrt{ux \cdot \left(2 + \left(maxCos \cdot -2 - ux \cdot {\left(-1 + maxCos\right)}^{2}\right)\right)}\\
\mathbf{else}:\\
\;\;\;\;\cos \left(\left(uy \cdot 2\right) \cdot \pi\right) \cdot \sqrt{ux \cdot \left(2 - ux\right)}\\
\end{array}
\end{array}
if (*.f32 uy #s(literal 2 binary32)) < 1.30999993e-4Initial program 56.6%
Taylor expanded in ux around 0 99.4%
cancel-sign-sub-inv99.4%
associate-*r*99.4%
mul-1-neg99.4%
sub-neg99.4%
metadata-eval99.4%
+-commutative99.4%
metadata-eval99.4%
*-commutative99.4%
Simplified99.4%
Taylor expanded in uy around 0 99.4%
mul-1-neg99.4%
unsub-neg99.4%
sub-neg99.4%
metadata-eval99.4%
+-commutative99.4%
+-commutative99.4%
Simplified99.4%
if 1.30999993e-4 < (*.f32 uy #s(literal 2 binary32)) Initial program 59.1%
Taylor expanded in ux around 0 98.0%
associate--l+98.0%
associate-*r*98.0%
mul-1-neg98.0%
fma-neg98.0%
sub-neg98.0%
metadata-eval98.0%
+-commutative98.0%
distribute-lft-neg-in98.0%
metadata-eval98.0%
*-commutative98.0%
Simplified98.0%
Taylor expanded in maxCos around 0 94.3%
neg-mul-194.3%
unsub-neg94.3%
Simplified94.3%
Final simplification97.3%
(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 57.6%
Taylor expanded in ux around 0 98.8%
associate--l+98.8%
associate-*r*98.8%
mul-1-neg98.8%
fma-neg98.8%
sub-neg98.8%
metadata-eval98.8%
+-commutative98.8%
distribute-lft-neg-in98.8%
metadata-eval98.8%
*-commutative98.8%
Simplified98.8%
Taylor expanded in maxCos around 0 94.0%
neg-mul-194.0%
unsub-neg94.0%
Simplified94.0%
Final simplification94.0%
(FPCore (ux uy maxCos)
:precision binary32
(*
ux
(sqrt
(-
(-
(+ (* (- 1.0 maxCos) (+ -1.0 maxCos)) (/ 1.0 ux))
(/ (+ -1.0 maxCos) ux))
(/ maxCos ux)))))
float code(float ux, float uy, float maxCos) {
return ux * sqrtf((((((1.0f - maxCos) * (-1.0f + maxCos)) + (1.0f / ux)) - ((-1.0f + maxCos) / ux)) - (maxCos / ux)));
}
real(4) function code(ux, uy, maxcos)
real(4), intent (in) :: ux
real(4), intent (in) :: uy
real(4), intent (in) :: maxcos
code = ux * sqrt((((((1.0e0 - maxcos) * ((-1.0e0) + maxcos)) + (1.0e0 / ux)) - (((-1.0e0) + maxcos) / ux)) - (maxcos / ux)))
end function
function code(ux, uy, maxCos) return Float32(ux * sqrt(Float32(Float32(Float32(Float32(Float32(Float32(1.0) - maxCos) * Float32(Float32(-1.0) + maxCos)) + Float32(Float32(1.0) / ux)) - Float32(Float32(Float32(-1.0) + maxCos) / ux)) - Float32(maxCos / ux)))) end
function tmp = code(ux, uy, maxCos) tmp = ux * sqrt((((((single(1.0) - maxCos) * (single(-1.0) + maxCos)) + (single(1.0) / ux)) - ((single(-1.0) + maxCos) / ux)) - (maxCos / ux))); end
\begin{array}{l}
\\
ux \cdot \sqrt{\left(\left(\left(1 - maxCos\right) \cdot \left(-1 + maxCos\right) + \frac{1}{ux}\right) - \frac{-1 + maxCos}{ux}\right) - \frac{maxCos}{ux}}
\end{array}
Initial program 57.6%
associate-*l*57.6%
sub-neg57.6%
+-commutative57.6%
distribute-rgt-neg-in57.6%
fma-define57.6%
Simplified57.6%
Taylor expanded in ux around inf 98.7%
Taylor expanded in uy around 0 79.5%
Final simplification79.5%
(FPCore (ux uy maxCos) :precision binary32 (sqrt (* ux (- 2.0 (* 2.0 maxCos)))))
float code(float ux, float uy, float maxCos) {
return sqrtf((ux * (2.0f - (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 - (2.0e0 * maxcos))))
end function
function code(ux, uy, maxCos) return sqrt(Float32(ux * Float32(Float32(2.0) - Float32(Float32(2.0) * maxCos)))) end
function tmp = code(ux, uy, maxCos) tmp = sqrt((ux * (single(2.0) - (single(2.0) * maxCos)))); end
\begin{array}{l}
\\
\sqrt{ux \cdot \left(2 - 2 \cdot maxCos\right)}
\end{array}
Initial program 57.6%
associate-*l*57.6%
sub-neg57.6%
+-commutative57.6%
distribute-rgt-neg-in57.6%
fma-define57.6%
Simplified57.6%
Taylor expanded in uy around 0 48.1%
Simplified48.2%
Taylor expanded in ux around 0 65.2%
Final simplification65.2%
(FPCore (ux uy maxCos) :precision binary32 (* ux (sqrt (+ -1.0 (/ 2.0 ux)))))
float code(float ux, float uy, float maxCos) {
return ux * sqrtf((-1.0f + (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 = ux * sqrt(((-1.0e0) + (2.0e0 / ux)))
end function
function code(ux, uy, maxCos) return Float32(ux * sqrt(Float32(Float32(-1.0) + Float32(Float32(2.0) / ux)))) end
function tmp = code(ux, uy, maxCos) tmp = ux * sqrt((single(-1.0) + (single(2.0) / ux))); end
\begin{array}{l}
\\
ux \cdot \sqrt{-1 + \frac{2}{ux}}
\end{array}
Initial program 57.6%
Taylor expanded in ux around inf 98.7%
Taylor expanded in maxCos around 0 93.6%
associate-*l*93.6%
associate-*r*93.6%
*-commutative93.6%
*-commutative93.6%
*-commutative93.6%
sub-neg93.6%
associate-*r/93.6%
metadata-eval93.6%
metadata-eval93.6%
Simplified93.6%
Taylor expanded in uy around 0 75.8%
sub-neg75.8%
metadata-eval75.8%
+-commutative75.8%
associate-*r/75.8%
metadata-eval75.8%
Simplified75.8%
Final simplification75.8%
(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 57.6%
associate-*l*57.6%
sub-neg57.6%
+-commutative57.6%
distribute-rgt-neg-in57.6%
fma-define57.6%
Simplified57.6%
Taylor expanded in uy around 0 48.1%
Simplified48.2%
Taylor expanded in ux around 0 65.2%
Taylor expanded in maxCos around 0 62.8%
*-commutative62.8%
Simplified62.8%
Final simplification62.8%
herbie shell --seed 2024077
(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)))))))