
(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 12 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 PI)))
(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(((float) M_PI)))), 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(Float32(pi)))), (exp(Float32(-cosTheta)) ^ cosTheta), c))) end
\begin{array}{l}
\\
\frac{1}{1 + \mathsf{fma}\left(\frac{\sqrt{1 + cosTheta \cdot -2}}{cosTheta \cdot \sqrt{\pi}}, {\left(e^{-cosTheta}\right)}^{cosTheta}, c\right)}
\end{array}
Initial program 98.1%
associate-+l+98.1%
+-commutative98.1%
fma-define98.1%
Simplified98.6%
Final simplification98.6%
(FPCore (cosTheta c)
:precision binary32
(/
1.0
(+
1.0
(+
c
(/
(*
(exp (- (pow cosTheta 2.0)))
(sqrt (* cosTheta (- (/ 1.0 (* cosTheta PI)) (/ 2.0 PI)))))
cosTheta)))))
float code(float cosTheta, float c) {
return 1.0f / (1.0f + (c + ((expf(-powf(cosTheta, 2.0f)) * sqrtf((cosTheta * ((1.0f / (cosTheta * ((float) M_PI))) - (2.0f / ((float) M_PI)))))) / cosTheta)));
}
function code(cosTheta, c) return Float32(Float32(1.0) / Float32(Float32(1.0) + Float32(c + Float32(Float32(exp(Float32(-(cosTheta ^ Float32(2.0)))) * sqrt(Float32(cosTheta * Float32(Float32(Float32(1.0) / Float32(cosTheta * Float32(pi))) - Float32(Float32(2.0) / Float32(pi)))))) / cosTheta)))) end
function tmp = code(cosTheta, c) tmp = single(1.0) / (single(1.0) + (c + ((exp(-(cosTheta ^ single(2.0))) * sqrt((cosTheta * ((single(1.0) / (cosTheta * single(pi))) - (single(2.0) / single(pi)))))) / cosTheta))); end
\begin{array}{l}
\\
\frac{1}{1 + \left(c + \frac{e^{-{cosTheta}^{2}} \cdot \sqrt{cosTheta \cdot \left(\frac{1}{cosTheta \cdot \pi} - \frac{2}{\pi}\right)}}{cosTheta}\right)}
\end{array}
Initial program 98.1%
+-commutative98.1%
fma-define98.1%
associate-*l/98.6%
*-lft-identity98.6%
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%
Taylor expanded in c around 0 98.1%
Taylor expanded in cosTheta around inf 98.0%
*-commutative98.0%
associate-*r/98.0%
metadata-eval98.0%
Simplified98.0%
associate-*l/98.2%
mul-1-neg98.2%
Applied egg-rr98.2%
Final simplification98.2%
(FPCore (cosTheta c)
:precision binary32
(/
1.0
(+
1.0
(+
c
(*
(sqrt (/ (+ 1.0 (* cosTheta -2.0)) PI))
(/ (exp (- (pow cosTheta 2.0))) cosTheta))))))
float code(float cosTheta, float c) {
return 1.0f / (1.0f + (c + (sqrtf(((1.0f + (cosTheta * -2.0f)) / ((float) M_PI))) * (expf(-powf(cosTheta, 2.0f)) / cosTheta))));
}
function code(cosTheta, c) return Float32(Float32(1.0) / Float32(Float32(1.0) + Float32(c + Float32(sqrt(Float32(Float32(Float32(1.0) + Float32(cosTheta * Float32(-2.0))) / Float32(pi))) * Float32(exp(Float32(-(cosTheta ^ Float32(2.0)))) / cosTheta))))) end
function tmp = code(cosTheta, c) tmp = single(1.0) / (single(1.0) + (c + (sqrt(((single(1.0) + (cosTheta * single(-2.0))) / single(pi))) * (exp(-(cosTheta ^ single(2.0))) / cosTheta)))); end
\begin{array}{l}
\\
\frac{1}{1 + \left(c + \sqrt{\frac{1 + cosTheta \cdot -2}{\pi}} \cdot \frac{e^{-{cosTheta}^{2}}}{cosTheta}\right)}
\end{array}
Initial program 98.1%
+-commutative98.1%
fma-define98.1%
associate-*l/98.6%
*-lft-identity98.6%
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%
Taylor expanded in c around 0 98.1%
Final simplification98.1%
(FPCore (cosTheta c)
:precision binary32
(/
1.0
(+
1.0
(*
(sqrt (/ (+ 1.0 (* cosTheta -2.0)) PI))
(/ (exp (- (pow cosTheta 2.0))) cosTheta)))))
float code(float cosTheta, float c) {
return 1.0f / (1.0f + (sqrtf(((1.0f + (cosTheta * -2.0f)) / ((float) M_PI))) * (expf(-powf(cosTheta, 2.0f)) / 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))) * Float32(exp(Float32(-(cosTheta ^ Float32(2.0)))) / cosTheta)))) end
function tmp = code(cosTheta, c) tmp = single(1.0) / (single(1.0) + (sqrt(((single(1.0) + (cosTheta * single(-2.0))) / single(pi))) * (exp(-(cosTheta ^ single(2.0))) / cosTheta))); end
\begin{array}{l}
\\
\frac{1}{1 + \sqrt{\frac{1 + cosTheta \cdot -2}{\pi}} \cdot \frac{e^{-{cosTheta}^{2}}}{cosTheta}}
\end{array}
Initial program 98.1%
*-un-lft-identity98.1%
inv-pow98.1%
sqrt-pow298.1%
metadata-eval98.1%
Applied egg-rr98.1%
*-lft-identity98.1%
Simplified98.1%
Taylor expanded in c around 0 97.9%
neg-mul-197.9%
cancel-sign-sub-inv97.9%
metadata-eval97.9%
Simplified97.9%
Final simplification97.9%
(FPCore (cosTheta c) :precision binary32 (* cosTheta (- (sqrt PI) (* (+ 1.0 (- c (sqrt (/ 1.0 PI)))) (* cosTheta PI)))))
float code(float cosTheta, float c) {
return cosTheta * (sqrtf(((float) M_PI)) - ((1.0f + (c - sqrtf((1.0f / ((float) M_PI))))) * (cosTheta * ((float) M_PI))));
}
function code(cosTheta, c) return Float32(cosTheta * Float32(sqrt(Float32(pi)) - Float32(Float32(Float32(1.0) + Float32(c - sqrt(Float32(Float32(1.0) / Float32(pi))))) * Float32(cosTheta * Float32(pi))))) end
function tmp = code(cosTheta, c) tmp = cosTheta * (sqrt(single(pi)) - ((single(1.0) + (c - sqrt((single(1.0) / single(pi))))) * (cosTheta * single(pi)))); end
\begin{array}{l}
\\
cosTheta \cdot \left(\sqrt{\pi} - \left(1 + \left(c - \sqrt{\frac{1}{\pi}}\right)\right) \cdot \left(cosTheta \cdot \pi\right)\right)
\end{array}
Initial program 98.1%
associate-+l+98.1%
+-commutative98.1%
fma-define98.1%
Simplified98.6%
Taylor expanded in cosTheta around 0 95.8%
mul-1-neg95.8%
unsub-neg95.8%
*-commutative95.8%
*-commutative95.8%
associate-*l*95.8%
mul-1-neg95.8%
unsub-neg95.8%
*-commutative95.8%
Simplified95.8%
Final simplification95.8%
(FPCore (cosTheta c) :precision binary32 (* cosTheta (+ (sqrt PI) (* (* cosTheta PI) (+ -1.0 (sqrt (/ 1.0 PI)))))))
float code(float cosTheta, float c) {
return cosTheta * (sqrtf(((float) M_PI)) + ((cosTheta * ((float) M_PI)) * (-1.0f + sqrtf((1.0f / ((float) M_PI))))));
}
function code(cosTheta, c) return Float32(cosTheta * Float32(sqrt(Float32(pi)) + Float32(Float32(cosTheta * Float32(pi)) * Float32(Float32(-1.0) + sqrt(Float32(Float32(1.0) / Float32(pi))))))) end
function tmp = code(cosTheta, c) tmp = cosTheta * (sqrt(single(pi)) + ((cosTheta * single(pi)) * (single(-1.0) + sqrt((single(1.0) / single(pi)))))); end
\begin{array}{l}
\\
cosTheta \cdot \left(\sqrt{\pi} + \left(cosTheta \cdot \pi\right) \cdot \left(-1 + \sqrt{\frac{1}{\pi}}\right)\right)
\end{array}
Initial program 98.1%
+-commutative98.1%
fma-define98.1%
associate-*l/98.6%
*-lft-identity98.6%
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%
Taylor expanded in c around 0 98.1%
Taylor expanded in cosTheta around 0 95.1%
mul-1-neg95.1%
*-commutative95.1%
Simplified95.1%
Taylor expanded in c around 0 95.1%
associate--l+95.1%
sub-neg95.1%
mul-1-neg95.1%
+-commutative95.1%
distribute-rgt-out95.1%
Simplified95.1%
Taylor expanded in cosTheta around 0 95.7%
mul-1-neg95.7%
unsub-neg95.7%
associate-*r*95.7%
mul-1-neg95.7%
unsub-neg95.7%
Simplified95.7%
Final simplification95.7%
(FPCore (cosTheta c) :precision binary32 (/ 1.0 (+ 1.0 (- (/ 1.0 (* cosTheta (sqrt PI))) (pow PI -0.5)))))
float code(float cosTheta, float c) {
return 1.0f / (1.0f + ((1.0f / (cosTheta * sqrtf(((float) M_PI)))) - powf(((float) M_PI), -0.5f)));
}
function code(cosTheta, c) return Float32(Float32(1.0) / Float32(Float32(1.0) + Float32(Float32(Float32(1.0) / Float32(cosTheta * sqrt(Float32(pi)))) - (Float32(pi) ^ Float32(-0.5))))) end
function tmp = code(cosTheta, c) tmp = single(1.0) / (single(1.0) + ((single(1.0) / (cosTheta * sqrt(single(pi)))) - (single(pi) ^ single(-0.5)))); end
\begin{array}{l}
\\
\frac{1}{1 + \left(\frac{1}{cosTheta \cdot \sqrt{\pi}} - {\pi}^{-0.5}\right)}
\end{array}
Initial program 98.1%
+-commutative98.1%
fma-define98.1%
associate-*l/98.6%
*-lft-identity98.6%
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%
Taylor expanded in c around 0 98.1%
Taylor expanded in cosTheta around 0 95.1%
mul-1-neg95.1%
*-commutative95.1%
Simplified95.1%
Taylor expanded in c around 0 95.1%
associate--l+95.1%
sub-neg95.1%
mul-1-neg95.1%
+-commutative95.1%
distribute-rgt-out95.1%
Simplified95.1%
distribute-rgt-in95.1%
pow1/295.1%
inv-pow95.1%
pow-pow95.1%
metadata-eval95.1%
sqrt-div95.1%
metadata-eval95.1%
div-inv95.6%
associate-/l/95.7%
Applied egg-rr95.7%
+-commutative95.7%
mul-1-neg95.7%
unsub-neg95.7%
*-commutative95.7%
Simplified95.7%
Final simplification95.7%
(FPCore (cosTheta c) :precision binary32 (/ 1.0 (+ 1.0 (+ c (* (sqrt (/ 1.0 PI)) (- -1.0 (/ -1.0 cosTheta)))))))
float code(float cosTheta, float c) {
return 1.0f / (1.0f + (c + (sqrtf((1.0f / ((float) M_PI))) * (-1.0f - (-1.0f / cosTheta)))));
}
function code(cosTheta, c) return Float32(Float32(1.0) / Float32(Float32(1.0) + Float32(c + Float32(sqrt(Float32(Float32(1.0) / Float32(pi))) * Float32(Float32(-1.0) - Float32(Float32(-1.0) / cosTheta)))))) end
function tmp = code(cosTheta, c) tmp = single(1.0) / (single(1.0) + (c + (sqrt((single(1.0) / single(pi))) * (single(-1.0) - (single(-1.0) / cosTheta))))); end
\begin{array}{l}
\\
\frac{1}{1 + \left(c + \sqrt{\frac{1}{\pi}} \cdot \left(-1 - \frac{-1}{cosTheta}\right)\right)}
\end{array}
Initial program 98.1%
+-commutative98.1%
fma-define98.1%
associate-*l/98.6%
*-lft-identity98.6%
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%
Taylor expanded in c around 0 98.1%
Taylor expanded in cosTheta around 0 95.1%
mul-1-neg95.1%
*-commutative95.1%
Simplified95.1%
Taylor expanded in cosTheta around inf 95.2%
distribute-rgt-out95.2%
Simplified95.2%
Final simplification95.2%
(FPCore (cosTheta c) :precision binary32 (/ 1.0 (+ 1.0 (* (pow PI -0.5) (- -1.0 (/ -1.0 cosTheta))))))
float code(float cosTheta, float c) {
return 1.0f / (1.0f + (powf(((float) M_PI), -0.5f) * (-1.0f - (-1.0f / cosTheta))));
}
function code(cosTheta, c) return Float32(Float32(1.0) / Float32(Float32(1.0) + Float32((Float32(pi) ^ Float32(-0.5)) * Float32(Float32(-1.0) - Float32(Float32(-1.0) / cosTheta))))) end
function tmp = code(cosTheta, c) tmp = single(1.0) / (single(1.0) + ((single(pi) ^ single(-0.5)) * (single(-1.0) - (single(-1.0) / cosTheta)))); end
\begin{array}{l}
\\
\frac{1}{1 + {\pi}^{-0.5} \cdot \left(-1 - \frac{-1}{cosTheta}\right)}
\end{array}
Initial program 98.1%
+-commutative98.1%
fma-define98.1%
associate-*l/98.6%
*-lft-identity98.6%
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%
Taylor expanded in c around 0 98.1%
Taylor expanded in cosTheta around 0 95.1%
mul-1-neg95.1%
*-commutative95.1%
Simplified95.1%
Taylor expanded in c around 0 95.1%
associate--l+95.1%
sub-neg95.1%
mul-1-neg95.1%
+-commutative95.1%
distribute-rgt-out95.1%
Simplified95.1%
distribute-lft-in95.1%
pow1/295.1%
inv-pow95.1%
pow-pow95.1%
metadata-eval95.1%
pow1/295.1%
inv-pow95.1%
pow-pow95.1%
metadata-eval95.1%
Applied egg-rr95.1%
distribute-lft-in95.1%
+-commutative95.1%
Simplified95.1%
Final simplification95.1%
(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 98.1%
+-commutative98.1%
fma-define98.1%
associate-*l/98.6%
*-lft-identity98.6%
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%
Taylor expanded in c around 0 98.1%
Taylor expanded in cosTheta around 0 93.6%
Final simplification93.6%
(FPCore (cosTheta c) :precision binary32 (/ 1.0 (+ 1.0 c)))
float code(float cosTheta, float c) {
return 1.0f / (1.0f + c);
}
real(4) function code(costheta, c)
real(4), intent (in) :: costheta
real(4), intent (in) :: c
code = 1.0e0 / (1.0e0 + c)
end function
function code(cosTheta, c) return Float32(Float32(1.0) / Float32(Float32(1.0) + c)) end
function tmp = code(cosTheta, c) tmp = single(1.0) / (single(1.0) + c); end
\begin{array}{l}
\\
\frac{1}{1 + c}
\end{array}
Initial program 98.1%
associate-*l/98.6%
*-un-lft-identity98.6%
sub-neg98.6%
sub-neg98.6%
add-sqr-sqrt-0.0%
sqrt-unprod93.2%
sqr-neg93.2%
sqrt-unprod93.2%
add-sqr-sqrt93.2%
add-sqr-sqrt-0.0%
sqrt-unprod92.8%
sqr-neg92.8%
sqrt-unprod92.8%
add-sqr-sqrt92.8%
Applied egg-rr92.8%
Taylor expanded in cosTheta around 0 93.2%
Taylor expanded in cosTheta around inf 10.4%
Final simplification10.4%
(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}
\\
\frac{1}{c}
\end{array}
Initial program 98.1%
associate-+l+98.1%
+-commutative98.1%
fma-define98.1%
Simplified98.6%
Taylor expanded in c around inf 4.9%
Final simplification4.9%
herbie shell --seed 2024077
(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))))))