
(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 8 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
(let* ((t_0 (sin (* uy PI))))
(*
(+ (cos (* uy (* 2.0 PI))) (fma (- t_0) t_0 (pow t_0 2.0)))
(sqrt
(* ux (+ 2.0 (- (* maxCos (- (- (* 2.0 ux) (* ux maxCos)) 2.0)) ux)))))))
float code(float ux, float uy, float maxCos) {
float t_0 = sinf((uy * ((float) M_PI)));
return (cosf((uy * (2.0f * ((float) M_PI)))) + fmaf(-t_0, t_0, powf(t_0, 2.0f))) * sqrtf((ux * (2.0f + ((maxCos * (((2.0f * ux) - (ux * maxCos)) - 2.0f)) - ux))));
}
function code(ux, uy, maxCos) t_0 = sin(Float32(uy * Float32(pi))) return Float32(Float32(cos(Float32(uy * Float32(Float32(2.0) * Float32(pi)))) + fma(Float32(-t_0), t_0, (t_0 ^ Float32(2.0)))) * sqrt(Float32(ux * Float32(Float32(2.0) + Float32(Float32(maxCos * Float32(Float32(Float32(Float32(2.0) * ux) - Float32(ux * maxCos)) - Float32(2.0))) - ux))))) end
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \sin \left(uy \cdot \pi\right)\\
\left(\cos \left(uy \cdot \left(2 \cdot \pi\right)\right) + \mathsf{fma}\left(-t\_0, t\_0, {t\_0}^{2}\right)\right) \cdot \sqrt{ux \cdot \left(2 + \left(maxCos \cdot \left(\left(2 \cdot ux - ux \cdot maxCos\right) - 2\right) - ux\right)\right)}
\end{array}
\end{array}
Initial program 57.8%
Taylor expanded in ux around 0 99.0%
associate--l+99.0%
associate-*r*99.0%
mul-1-neg99.0%
sub-neg99.0%
metadata-eval99.0%
+-commutative99.0%
Simplified99.0%
Taylor expanded in maxCos around 0 99.0%
add-cube-cbrt98.9%
pow398.9%
Applied egg-rr98.9%
*-commutative98.9%
rem-cube-cbrt99.0%
associate-*r*99.0%
cos-298.8%
prod-diff98.8%
fmm-def98.8%
cos-299.0%
associate-*r*99.0%
*-commutative99.0%
associate-*l*99.0%
pow299.0%
Applied egg-rr99.0%
Final simplification99.0%
(FPCore (ux uy maxCos) :precision binary32 (* (cos (* PI (* uy 2.0))) (sqrt (* ux (+ 2.0 (- (* maxCos (+ (* ux (- 2.0 maxCos)) -2.0)) ux))))))
float code(float ux, float uy, float maxCos) {
return cosf((((float) M_PI) * (uy * 2.0f))) * sqrtf((ux * (2.0f + ((maxCos * ((ux * (2.0f - maxCos)) + -2.0f)) - ux))));
}
function code(ux, uy, maxCos) return Float32(cos(Float32(Float32(pi) * Float32(uy * Float32(2.0)))) * 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((single(pi) * (uy * single(2.0)))) * sqrt((ux * (single(2.0) + ((maxCos * ((ux * (single(2.0) - maxCos)) + single(-2.0))) - ux)))); end
\begin{array}{l}
\\
\cos \left(\pi \cdot \left(uy \cdot 2\right)\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 57.8%
Taylor expanded in ux around 0 99.0%
associate--l+99.0%
associate-*r*99.0%
mul-1-neg99.0%
sub-neg99.0%
metadata-eval99.0%
+-commutative99.0%
Simplified99.0%
Taylor expanded in maxCos around 0 99.0%
*-un-lft-identity99.0%
neg-mul-199.0%
+-commutative99.0%
fma-define99.0%
associate--l+99.0%
fma-define99.0%
*-commutative99.0%
fmm-def99.0%
metadata-eval99.0%
Applied egg-rr99.0%
*-lft-identity99.0%
fmm-undef99.0%
fma-undefine99.0%
neg-mul-199.0%
fma-undefine99.0%
associate-+r+99.0%
distribute-lft-neg-in99.0%
mul-1-neg99.0%
*-commutative99.0%
distribute-rgt-in99.0%
+-commutative99.0%
mul-1-neg99.0%
unsub-neg99.0%
Simplified99.0%
Final simplification99.0%
(FPCore (ux uy maxCos) :precision binary32 (* (cos (* PI (* uy 2.0))) (sqrt (* ux (+ 2.0 (- (* maxCos (- (* 2.0 ux) 2.0)) ux))))))
float code(float ux, float uy, float maxCos) {
return cosf((((float) M_PI) * (uy * 2.0f))) * sqrtf((ux * (2.0f + ((maxCos * ((2.0f * ux) - 2.0f)) - ux))));
}
function code(ux, uy, maxCos) return Float32(cos(Float32(Float32(pi) * Float32(uy * Float32(2.0)))) * 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((single(pi) * (uy * single(2.0)))) * sqrt((ux * (single(2.0) + ((maxCos * ((single(2.0) * ux) - single(2.0))) - ux)))); end
\begin{array}{l}
\\
\cos \left(\pi \cdot \left(uy \cdot 2\right)\right) \cdot \sqrt{ux \cdot \left(2 + \left(maxCos \cdot \left(2 \cdot ux - 2\right) - ux\right)\right)}
\end{array}
Initial program 57.8%
Taylor expanded in ux around 0 99.0%
associate--l+99.0%
associate-*r*99.0%
mul-1-neg99.0%
sub-neg99.0%
metadata-eval99.0%
+-commutative99.0%
Simplified99.0%
Taylor expanded in maxCos around 0 99.0%
*-un-lft-identity99.0%
neg-mul-199.0%
+-commutative99.0%
fma-define99.0%
associate--l+99.0%
fma-define99.0%
*-commutative99.0%
fmm-def99.0%
metadata-eval99.0%
Applied egg-rr99.0%
*-lft-identity99.0%
fmm-undef99.0%
fma-undefine99.0%
neg-mul-199.0%
fma-undefine99.0%
associate-+r+99.0%
distribute-lft-neg-in99.0%
mul-1-neg99.0%
*-commutative99.0%
distribute-rgt-in99.0%
+-commutative99.0%
mul-1-neg99.0%
unsub-neg99.0%
Simplified99.0%
Taylor expanded in maxCos around 0 98.6%
Final simplification98.6%
(FPCore (ux uy maxCos) :precision binary32 (* (cos (* PI (* uy 2.0))) (sqrt (* ux (- 2.0 ux)))))
float code(float ux, float uy, float maxCos) {
return cosf((((float) M_PI) * (uy * 2.0f))) * sqrtf((ux * (2.0f - ux)));
}
function code(ux, uy, maxCos) return Float32(cos(Float32(Float32(pi) * Float32(uy * Float32(2.0)))) * sqrt(Float32(ux * Float32(Float32(2.0) - ux)))) end
function tmp = code(ux, uy, maxCos) tmp = cos((single(pi) * (uy * single(2.0)))) * sqrt((ux * (single(2.0) - ux))); end
\begin{array}{l}
\\
\cos \left(\pi \cdot \left(uy \cdot 2\right)\right) \cdot \sqrt{ux \cdot \left(2 - ux\right)}
\end{array}
Initial program 57.8%
Taylor expanded in ux around 0 99.0%
associate--l+99.0%
associate-*r*99.0%
mul-1-neg99.0%
sub-neg99.0%
metadata-eval99.0%
+-commutative99.0%
Simplified99.0%
Taylor expanded in maxCos around 0 94.4%
neg-mul-194.4%
unsub-neg94.4%
Simplified94.4%
Final simplification94.4%
(FPCore (ux uy maxCos) :precision binary32 (sqrt (* ux (- (+ 2.0 (* maxCos (- (* ux (- 2.0 maxCos)) 2.0))) ux))))
float code(float ux, float uy, float maxCos) {
return sqrtf((ux * ((2.0f + (maxCos * ((ux * (2.0f - maxCos)) - 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 + (maxcos * ((ux * (2.0e0 - maxcos)) - 2.0e0))) - ux)))
end function
function code(ux, uy, maxCos) return sqrt(Float32(ux * Float32(Float32(Float32(2.0) + Float32(maxCos * Float32(Float32(ux * Float32(Float32(2.0) - maxCos)) - Float32(2.0)))) - ux))) end
function tmp = code(ux, uy, maxCos) tmp = sqrt((ux * ((single(2.0) + (maxCos * ((ux * (single(2.0) - maxCos)) - single(2.0)))) - ux))); end
\begin{array}{l}
\\
\sqrt{ux \cdot \left(\left(2 + maxCos \cdot \left(ux \cdot \left(2 - maxCos\right) - 2\right)\right) - ux\right)}
\end{array}
Initial program 57.8%
Taylor expanded in ux around 0 99.0%
associate--l+99.0%
associate-*r*99.0%
mul-1-neg99.0%
sub-neg99.0%
metadata-eval99.0%
+-commutative99.0%
Simplified99.0%
Taylor expanded in maxCos around 0 99.0%
*-un-lft-identity99.0%
neg-mul-199.0%
+-commutative99.0%
fma-define99.0%
associate--l+99.0%
fma-define99.0%
*-commutative99.0%
fmm-def99.0%
metadata-eval99.0%
Applied egg-rr99.0%
*-lft-identity99.0%
fmm-undef99.0%
fma-undefine99.0%
neg-mul-199.0%
fma-undefine99.0%
associate-+r+99.0%
distribute-lft-neg-in99.0%
mul-1-neg99.0%
*-commutative99.0%
distribute-rgt-in99.0%
+-commutative99.0%
mul-1-neg99.0%
unsub-neg99.0%
Simplified99.0%
Taylor expanded in uy around 0 79.3%
(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 57.8%
associate-*l*57.8%
sub-neg57.8%
+-commutative57.8%
distribute-rgt-neg-in57.8%
fma-define57.8%
Simplified57.9%
Taylor expanded in ux around inf 98.7%
Taylor expanded in maxCos around 0 93.9%
sub-neg93.9%
associate-*r/93.9%
metadata-eval93.9%
metadata-eval93.9%
Simplified93.9%
Taylor expanded in uy around 0 76.0%
Final simplification76.0%
(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 57.8%
associate-*l*57.8%
sub-neg57.8%
+-commutative57.8%
distribute-rgt-neg-in57.8%
fma-define57.8%
Simplified57.9%
Taylor expanded in uy around 0 50.0%
mul-1-neg50.0%
unsub-neg50.0%
sub-neg50.0%
metadata-eval50.0%
distribute-lft-in50.0%
*-commutative50.0%
mul-1-neg50.0%
sub-neg50.0%
*-commutative50.0%
associate--l+49.9%
unpow249.9%
sub-neg49.9%
Simplified50.0%
Taylor expanded in ux around 0 63.2%
(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 57.8%
associate-*l*57.8%
sub-neg57.8%
+-commutative57.8%
distribute-rgt-neg-in57.8%
fma-define57.8%
Simplified57.9%
Taylor expanded in uy around 0 50.0%
mul-1-neg50.0%
unsub-neg50.0%
sub-neg50.0%
metadata-eval50.0%
distribute-lft-in50.0%
*-commutative50.0%
mul-1-neg50.0%
sub-neg50.0%
*-commutative50.0%
associate--l+49.9%
unpow249.9%
sub-neg49.9%
Simplified50.0%
Taylor expanded in ux around 0 63.2%
Taylor expanded in maxCos around 0 61.6%
Final simplification61.6%
herbie shell --seed 2024157
(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)))))))