
(FPCore (cosTheta c)
:precision binary32
(/
1.0
(+
(+ 1.0 c)
(*
(* (/ 1.0 (sqrt PI)) (/ (sqrt (- (- 1.0 cosTheta) cosTheta)) cosTheta))
(exp (* (- cosTheta) cosTheta))))))
float code(float cosTheta, float c) {
return 1.0f / ((1.0f + c) + (((1.0f / sqrtf(((float) M_PI))) * (sqrtf(((1.0f - cosTheta) - cosTheta)) / cosTheta)) * expf((-cosTheta * cosTheta))));
}
function code(cosTheta, c) return Float32(Float32(1.0) / Float32(Float32(Float32(1.0) + c) + Float32(Float32(Float32(Float32(1.0) / sqrt(Float32(pi))) * Float32(sqrt(Float32(Float32(Float32(1.0) - cosTheta) - cosTheta)) / cosTheta)) * exp(Float32(Float32(-cosTheta) * cosTheta))))) end
function tmp = code(cosTheta, c) tmp = single(1.0) / ((single(1.0) + c) + (((single(1.0) / sqrt(single(pi))) * (sqrt(((single(1.0) - cosTheta) - cosTheta)) / cosTheta)) * exp((-cosTheta * cosTheta)))); end
\begin{array}{l}
\\
\frac{1}{\left(1 + c\right) + \left(\frac{1}{\sqrt{\pi}} \cdot \frac{\sqrt{\left(1 - cosTheta\right) - cosTheta}}{cosTheta}\right) \cdot e^{\left(-cosTheta\right) \cdot cosTheta}}
\end{array}
Sampling outcomes in binary32 precision:
Herbie found 11 alternatives:
| Alternative | Accuracy | Speedup |
|---|
(FPCore (cosTheta c)
:precision binary32
(/
1.0
(+
(+ 1.0 c)
(*
(* (/ 1.0 (sqrt PI)) (/ (sqrt (- (- 1.0 cosTheta) cosTheta)) cosTheta))
(exp (* (- cosTheta) cosTheta))))))
float code(float cosTheta, float c) {
return 1.0f / ((1.0f + c) + (((1.0f / sqrtf(((float) M_PI))) * (sqrtf(((1.0f - cosTheta) - cosTheta)) / cosTheta)) * expf((-cosTheta * cosTheta))));
}
function code(cosTheta, c) return Float32(Float32(1.0) / Float32(Float32(Float32(1.0) + c) + Float32(Float32(Float32(Float32(1.0) / sqrt(Float32(pi))) * Float32(sqrt(Float32(Float32(Float32(1.0) - cosTheta) - cosTheta)) / cosTheta)) * exp(Float32(Float32(-cosTheta) * cosTheta))))) end
function tmp = code(cosTheta, c) tmp = single(1.0) / ((single(1.0) + c) + (((single(1.0) / sqrt(single(pi))) * (sqrt(((single(1.0) - cosTheta) - cosTheta)) / cosTheta)) * exp((-cosTheta * cosTheta)))); end
\begin{array}{l}
\\
\frac{1}{\left(1 + c\right) + \left(\frac{1}{\sqrt{\pi}} \cdot \frac{\sqrt{\left(1 - cosTheta\right) - cosTheta}}{cosTheta}\right) \cdot e^{\left(-cosTheta\right) \cdot cosTheta}}
\end{array}
(FPCore (cosTheta c)
:precision binary32
(/
1.0
(+
1.0
(fma
(/
(sqrt (+ 1.0 (* cosTheta -2.0)))
(* cosTheta (sqrt (pow (cbrt PI) 3.0))))
(pow (exp (- cosTheta)) cosTheta)
c))))
float code(float cosTheta, float c) {
return 1.0f / (1.0f + fmaf((sqrtf((1.0f + (cosTheta * -2.0f))) / (cosTheta * sqrtf(powf(cbrtf(((float) M_PI)), 3.0f)))), powf(expf(-cosTheta), cosTheta), c));
}
function code(cosTheta, c) return Float32(Float32(1.0) / Float32(Float32(1.0) + fma(Float32(sqrt(Float32(Float32(1.0) + Float32(cosTheta * Float32(-2.0)))) / Float32(cosTheta * sqrt((cbrt(Float32(pi)) ^ Float32(3.0))))), (exp(Float32(-cosTheta)) ^ cosTheta), c))) end
\begin{array}{l}
\\
\frac{1}{1 + \mathsf{fma}\left(\frac{\sqrt{1 + cosTheta \cdot -2}}{cosTheta \cdot \sqrt{{\left(\sqrt[3]{\pi}\right)}^{3}}}, {\left(e^{-cosTheta}\right)}^{cosTheta}, c\right)}
\end{array}
Initial program 97.9%
associate-+l+97.9%
+-commutative97.9%
fma-define97.9%
times-frac98.4%
*-lft-identity98.4%
associate--l-98.4%
sub-neg98.4%
neg-mul-198.4%
distribute-lft-out98.4%
distribute-rgt-out98.4%
metadata-eval98.4%
exp-prod98.4%
Simplified98.4%
add-cube-cbrt98.5%
pow398.5%
Applied egg-rr98.5%
Final simplification98.5%
(FPCore (cosTheta c) :precision binary32 (/ 1.0 (fma (/ (/ (sqrt (+ 1.0 (* cosTheta -2.0))) cosTheta) (sqrt PI)) (pow (exp cosTheta) (- cosTheta)) (+ 1.0 c))))
float code(float cosTheta, float c) {
return 1.0f / fmaf(((sqrtf((1.0f + (cosTheta * -2.0f))) / cosTheta) / sqrtf(((float) M_PI))), powf(expf(cosTheta), -cosTheta), (1.0f + c));
}
function code(cosTheta, c) return Float32(Float32(1.0) / fma(Float32(Float32(sqrt(Float32(Float32(1.0) + Float32(cosTheta * Float32(-2.0)))) / cosTheta) / sqrt(Float32(pi))), (exp(cosTheta) ^ Float32(-cosTheta)), Float32(Float32(1.0) + c))) end
\begin{array}{l}
\\
\frac{1}{\mathsf{fma}\left(\frac{\frac{\sqrt{1 + cosTheta \cdot -2}}{cosTheta}}{\sqrt{\pi}}, {\left(e^{cosTheta}\right)}^{\left(-cosTheta\right)}, 1 + c\right)}
\end{array}
Initial program 97.9%
+-commutative97.9%
fma-define97.9%
associate-*l/98.4%
*-lft-identity98.4%
associate--l-98.5%
sub-neg98.5%
neg-mul-198.5%
distribute-lft-out98.5%
distribute-rgt-out98.5%
metadata-eval98.5%
distribute-lft-neg-out98.5%
distribute-rgt-neg-out98.5%
exp-prod98.5%
Simplified98.5%
(FPCore (cosTheta c)
:precision binary32
(/
1.0
(+
(+ 1.0 c)
(*
(/ (sqrt (- 1.0 (+ cosTheta cosTheta))) (* cosTheta (sqrt PI)))
(exp (* cosTheta (- cosTheta)))))))
float code(float cosTheta, float c) {
return 1.0f / ((1.0f + c) + ((sqrtf((1.0f - (cosTheta + cosTheta))) / (cosTheta * sqrtf(((float) M_PI)))) * expf((cosTheta * -cosTheta))));
}
function code(cosTheta, c) return Float32(Float32(1.0) / Float32(Float32(Float32(1.0) + c) + Float32(Float32(sqrt(Float32(Float32(1.0) - Float32(cosTheta + cosTheta))) / Float32(cosTheta * sqrt(Float32(pi)))) * exp(Float32(cosTheta * Float32(-cosTheta)))))) end
function tmp = code(cosTheta, c) tmp = single(1.0) / ((single(1.0) + c) + ((sqrt((single(1.0) - (cosTheta + cosTheta))) / (cosTheta * sqrt(single(pi)))) * exp((cosTheta * -cosTheta)))); end
\begin{array}{l}
\\
\frac{1}{\left(1 + c\right) + \frac{\sqrt{1 - \left(cosTheta + cosTheta\right)}}{cosTheta \cdot \sqrt{\pi}} \cdot e^{cosTheta \cdot \left(-cosTheta\right)}}
\end{array}
Initial program 97.9%
frac-times98.4%
*-un-lft-identity98.4%
associate--l-98.4%
*-commutative98.4%
Applied egg-rr98.4%
Final simplification98.4%
(FPCore (cosTheta c)
:precision binary32
(/
1.0
(+
1.0
(+
c
(*
(/ (exp (* cosTheta (- cosTheta))) cosTheta)
(sqrt (/ (- 1.0 (* cosTheta 2.0)) PI)))))))
float code(float cosTheta, float c) {
return 1.0f / (1.0f + (c + ((expf((cosTheta * -cosTheta)) / cosTheta) * sqrtf(((1.0f - (cosTheta * 2.0f)) / ((float) M_PI))))));
}
function code(cosTheta, c) return Float32(Float32(1.0) / Float32(Float32(1.0) + Float32(c + Float32(Float32(exp(Float32(cosTheta * Float32(-cosTheta))) / cosTheta) * sqrt(Float32(Float32(Float32(1.0) - Float32(cosTheta * Float32(2.0))) / Float32(pi))))))) end
function tmp = code(cosTheta, c) tmp = single(1.0) / (single(1.0) + (c + ((exp((cosTheta * -cosTheta)) / cosTheta) * sqrt(((single(1.0) - (cosTheta * single(2.0))) / single(pi)))))); end
\begin{array}{l}
\\
\frac{1}{1 + \left(c + \frac{e^{cosTheta \cdot \left(-cosTheta\right)}}{cosTheta} \cdot \sqrt{\frac{1 - cosTheta \cdot 2}{\pi}}\right)}
\end{array}
Initial program 97.9%
associate-+l+97.9%
distribute-lft-neg-out97.9%
distribute-rgt-neg-out97.9%
exp-prod97.9%
Simplified97.9%
Taylor expanded in c around 0 98.1%
unpow298.1%
Applied egg-rr98.1%
Final simplification98.1%
(FPCore (cosTheta c)
:precision binary32
(/
1.0
(+
(+ 1.0 c)
(*
(exp (* cosTheta (- cosTheta)))
(/ (- 1.0 cosTheta) (* cosTheta (sqrt PI)))))))
float code(float cosTheta, float c) {
return 1.0f / ((1.0f + c) + (expf((cosTheta * -cosTheta)) * ((1.0f - cosTheta) / (cosTheta * sqrtf(((float) M_PI))))));
}
function code(cosTheta, c) return Float32(Float32(1.0) / Float32(Float32(Float32(1.0) + c) + Float32(exp(Float32(cosTheta * Float32(-cosTheta))) * Float32(Float32(Float32(1.0) - cosTheta) / Float32(cosTheta * sqrt(Float32(pi))))))) end
function tmp = code(cosTheta, c) tmp = single(1.0) / ((single(1.0) + c) + (exp((cosTheta * -cosTheta)) * ((single(1.0) - cosTheta) / (cosTheta * sqrt(single(pi)))))); end
\begin{array}{l}
\\
\frac{1}{\left(1 + c\right) + e^{cosTheta \cdot \left(-cosTheta\right)} \cdot \frac{1 - cosTheta}{cosTheta \cdot \sqrt{\pi}}}
\end{array}
Initial program 97.9%
frac-times98.4%
*-un-lft-identity98.4%
associate--l-98.4%
*-commutative98.4%
Applied egg-rr98.4%
Taylor expanded in cosTheta around 0 95.7%
Simplified95.7%
Final simplification95.7%
(FPCore (cosTheta c) :precision binary32 (* cosTheta (+ (sqrt PI) (* (* cosTheta PI) (+ -1.0 (- (sqrt (/ 1.0 PI)) c))))))
float code(float cosTheta, float c) {
return cosTheta * (sqrtf(((float) M_PI)) + ((cosTheta * ((float) M_PI)) * (-1.0f + (sqrtf((1.0f / ((float) M_PI))) - c))));
}
function code(cosTheta, c) return Float32(cosTheta * Float32(sqrt(Float32(pi)) + Float32(Float32(cosTheta * Float32(pi)) * Float32(Float32(-1.0) + Float32(sqrt(Float32(Float32(1.0) / Float32(pi))) - c))))) end
function tmp = code(cosTheta, c) tmp = cosTheta * (sqrt(single(pi)) + ((cosTheta * single(pi)) * (single(-1.0) + (sqrt((single(1.0) / single(pi))) - c)))); end
\begin{array}{l}
\\
cosTheta \cdot \left(\sqrt{\pi} + \left(cosTheta \cdot \pi\right) \cdot \left(-1 + \left(\sqrt{\frac{1}{\pi}} - c\right)\right)\right)
\end{array}
Initial program 97.9%
associate-+l+97.9%
distribute-lft-neg-out97.9%
distribute-rgt-neg-out97.9%
exp-prod97.9%
Simplified97.9%
Taylor expanded in cosTheta around 0 95.4%
mul-1-neg95.4%
unsub-neg95.4%
associate-*r*95.4%
mul-1-neg95.4%
unsub-neg95.4%
Simplified95.4%
Final simplification95.4%
(FPCore (cosTheta c) :precision binary32 (/ 1.0 (+ 1.0 (/ (sqrt (/ (+ 1.0 (* cosTheta -2.0)) PI)) cosTheta))))
float code(float cosTheta, float c) {
return 1.0f / (1.0f + (sqrtf(((1.0f + (cosTheta * -2.0f)) / ((float) M_PI))) / cosTheta));
}
function code(cosTheta, c) return Float32(Float32(1.0) / Float32(Float32(1.0) + Float32(sqrt(Float32(Float32(Float32(1.0) + Float32(cosTheta * Float32(-2.0))) / Float32(pi))) / cosTheta))) end
function tmp = code(cosTheta, c) tmp = single(1.0) / (single(1.0) + (sqrt(((single(1.0) + (cosTheta * single(-2.0))) / single(pi))) / cosTheta)); end
\begin{array}{l}
\\
\frac{1}{1 + \frac{\sqrt{\frac{1 + cosTheta \cdot -2}{\pi}}}{cosTheta}}
\end{array}
Initial program 97.9%
associate-+l+97.9%
distribute-lft-neg-out97.9%
distribute-rgt-neg-out97.9%
exp-prod97.9%
Simplified97.9%
Taylor expanded in c around 0 98.1%
Taylor expanded in cosTheta around 0 95.1%
Taylor expanded in c around 0 95.2%
associate-*l/95.2%
*-lft-identity95.2%
*-commutative95.2%
*-commutative95.2%
cancel-sign-sub-inv95.2%
metadata-eval95.2%
*-commutative95.2%
Simplified95.2%
(FPCore (cosTheta c) :precision binary32 (* cosTheta (sqrt PI)))
float code(float cosTheta, float c) {
return cosTheta * sqrtf(((float) M_PI));
}
function code(cosTheta, c) return Float32(cosTheta * sqrt(Float32(pi))) end
function tmp = code(cosTheta, c) tmp = cosTheta * sqrt(single(pi)); end
\begin{array}{l}
\\
cosTheta \cdot \sqrt{\pi}
\end{array}
Initial program 97.9%
associate-+l+97.9%
distribute-lft-neg-out97.9%
distribute-rgt-neg-out97.9%
exp-prod97.9%
Simplified97.9%
Taylor expanded in cosTheta around 0 93.4%
(FPCore (cosTheta c) :precision binary32 (* c (+ -1.0 (/ 1.0 c))))
float code(float cosTheta, float c) {
return c * (-1.0f + (1.0f / c));
}
real(4) function code(costheta, c)
real(4), intent (in) :: costheta
real(4), intent (in) :: c
code = c * ((-1.0e0) + (1.0e0 / c))
end function
function code(cosTheta, c) return Float32(c * Float32(Float32(-1.0) + Float32(Float32(1.0) / c))) end
function tmp = code(cosTheta, c) tmp = c * (single(-1.0) + (single(1.0) / c)); end
\begin{array}{l}
\\
c \cdot \left(-1 + \frac{1}{c}\right)
\end{array}
Initial program 97.9%
associate-+l+97.9%
+-commutative97.9%
fma-define97.9%
times-frac98.4%
*-lft-identity98.4%
associate--l-98.4%
sub-neg98.4%
neg-mul-198.4%
distribute-lft-out98.4%
distribute-rgt-out98.4%
metadata-eval98.4%
exp-prod98.4%
Simplified98.4%
add-cube-cbrt98.5%
pow398.5%
Applied egg-rr98.5%
Taylor expanded in c around inf 10.5%
Taylor expanded in c around 0 10.5%
mul-1-neg10.5%
sub-neg10.5%
Simplified10.5%
Taylor expanded in c around inf 10.5%
Final simplification10.5%
(FPCore (cosTheta c) :precision binary32 (- 1.0 c))
float code(float cosTheta, float c) {
return 1.0f - c;
}
real(4) function code(costheta, c)
real(4), intent (in) :: costheta
real(4), intent (in) :: c
code = 1.0e0 - c
end function
function code(cosTheta, c) return Float32(Float32(1.0) - c) end
function tmp = code(cosTheta, c) tmp = single(1.0) - c; end
\begin{array}{l}
\\
1 - c
\end{array}
Initial program 97.9%
associate-+l+97.9%
+-commutative97.9%
fma-define97.9%
times-frac98.4%
*-lft-identity98.4%
associate--l-98.4%
sub-neg98.4%
neg-mul-198.4%
distribute-lft-out98.4%
distribute-rgt-out98.4%
metadata-eval98.4%
exp-prod98.4%
Simplified98.4%
add-cube-cbrt98.5%
pow398.5%
Applied egg-rr98.5%
Taylor expanded in c around inf 10.5%
Taylor expanded in c around 0 10.5%
mul-1-neg10.5%
sub-neg10.5%
Simplified10.5%
(FPCore (cosTheta c) :precision binary32 1.0)
float code(float cosTheta, float c) {
return 1.0f;
}
real(4) function code(costheta, c)
real(4), intent (in) :: costheta
real(4), intent (in) :: c
code = 1.0e0
end function
function code(cosTheta, c) return Float32(1.0) end
function tmp = code(cosTheta, c) tmp = single(1.0); end
\begin{array}{l}
\\
1
\end{array}
Initial program 97.9%
associate-+l+97.9%
+-commutative97.9%
fma-define97.9%
times-frac98.4%
*-lft-identity98.4%
associate--l-98.4%
sub-neg98.4%
neg-mul-198.4%
distribute-lft-out98.4%
distribute-rgt-out98.4%
metadata-eval98.4%
exp-prod98.4%
Simplified98.4%
add-cube-cbrt98.5%
pow398.5%
Applied egg-rr98.5%
Taylor expanded in c around inf 10.5%
Taylor expanded in c around 0 10.5%
mul-1-neg10.5%
sub-neg10.5%
Simplified10.5%
Taylor expanded in c around 0 10.5%
herbie shell --seed 2024144
(FPCore (cosTheta c)
:name "Beckmann Sample, normalization factor"
:precision binary32
:pre (and (and (< 0.0 cosTheta) (< cosTheta 0.9999)) (and (< -1.0 c) (< c 1.0)))
(/ 1.0 (+ (+ 1.0 c) (* (* (/ 1.0 (sqrt PI)) (/ (sqrt (- (- 1.0 cosTheta) cosTheta)) cosTheta)) (exp (* (- cosTheta) cosTheta))))))