
(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
(+
c
(/
(exp (* cosTheta (- cosTheta)))
(/ (* cosTheta (sqrt PI)) (sqrt (fma cosTheta -2.0 1.0))))))))
float code(float cosTheta, float c) {
return 1.0f / (1.0f + (c + (expf((cosTheta * -cosTheta)) / ((cosTheta * sqrtf(((float) M_PI))) / sqrtf(fmaf(cosTheta, -2.0f, 1.0f))))));
}
function code(cosTheta, c) return Float32(Float32(1.0) / Float32(Float32(1.0) + Float32(c + Float32(exp(Float32(cosTheta * Float32(-cosTheta))) / Float32(Float32(cosTheta * sqrt(Float32(pi))) / sqrt(fma(cosTheta, Float32(-2.0), Float32(1.0)))))))) end
\begin{array}{l}
\\
\frac{1}{1 + \left(c + \frac{e^{cosTheta \cdot \left(-cosTheta\right)}}{\frac{cosTheta \cdot \sqrt{\pi}}{\sqrt{\mathsf{fma}\left(cosTheta, -2, 1\right)}}}\right)}
\end{array}
Initial program 98.0%
associate-+l+98.0%
+-commutative98.0%
fma-define98.0%
Simplified98.7%
associate-/l/98.5%
clear-num98.6%
inv-pow98.6%
+-commutative98.6%
fma-define98.6%
Applied egg-rr98.6%
fma-undefine98.6%
unpow-198.6%
associate-/r/98.7%
pow-exp98.7%
distribute-lft-neg-out98.7%
pow298.7%
Applied egg-rr98.7%
+-commutative98.7%
associate-*l/98.7%
neg-mul-198.7%
*-lft-identity98.7%
neg-mul-198.7%
associate-*l/98.7%
*-commutative98.7%
Simplified98.7%
unpow298.7%
Applied egg-rr98.7%
Final simplification98.7%
(FPCore (cosTheta c)
:precision binary32
(/
1.0
(+
1.0
(+
c
(*
(/ (exp (- (pow cosTheta 2.0))) cosTheta)
(sqrt (/ (+ 1.0 (* cosTheta -2.0)) PI)))))))
float code(float cosTheta, float c) {
return 1.0f / (1.0f + (c + ((expf(-powf(cosTheta, 2.0f)) / 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(2.0)))) / 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 ^ single(2.0))) / cosTheta) * sqrt(((single(1.0) + (cosTheta * single(-2.0))) / single(pi)))))); end
\begin{array}{l}
\\
\frac{1}{1 + \left(c + \frac{e^{-{cosTheta}^{2}}}{cosTheta} \cdot \sqrt{\frac{1 + cosTheta \cdot -2}{\pi}}\right)}
\end{array}
Initial program 98.0%
associate-+l+98.0%
+-commutative98.0%
fma-define98.0%
Simplified98.7%
Taylor expanded in c around 0 98.0%
Final simplification98.0%
(FPCore (cosTheta c)
:precision binary32
(/
1.0
(+
1.0
(*
(/ (exp (- (pow cosTheta 2.0))) cosTheta)
(sqrt (/ (- 1.0 (* cosTheta 2.0)) PI))))))
float code(float cosTheta, float c) {
return 1.0f / (1.0f + ((expf(-powf(cosTheta, 2.0f)) / cosTheta) * sqrtf(((1.0f - (cosTheta * 2.0f)) / ((float) M_PI)))));
}
function code(cosTheta, c) return Float32(Float32(1.0) / Float32(Float32(1.0) + Float32(Float32(exp(Float32(-(cosTheta ^ Float32(2.0)))) / 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) + ((exp(-(cosTheta ^ single(2.0))) / cosTheta) * sqrt(((single(1.0) - (cosTheta * single(2.0))) / single(pi))))); end
\begin{array}{l}
\\
\frac{1}{1 + \frac{e^{-{cosTheta}^{2}}}{cosTheta} \cdot \sqrt{\frac{1 - cosTheta \cdot 2}{\pi}}}
\end{array}
Initial program 98.0%
Taylor expanded in c around 0 97.8%
Final simplification97.8%
(FPCore (cosTheta c)
:precision binary32
(/
1.0
(+
1.0
(-
c
(/
(exp (* cosTheta (- cosTheta)))
(/
(* cosTheta (sqrt PI))
(- -1.0 (* cosTheta (+ -1.0 (* cosTheta -0.5))))))))))
float code(float cosTheta, float c) {
return 1.0f / (1.0f + (c - (expf((cosTheta * -cosTheta)) / ((cosTheta * sqrtf(((float) M_PI))) / (-1.0f - (cosTheta * (-1.0f + (cosTheta * -0.5f))))))));
}
function code(cosTheta, c) return Float32(Float32(1.0) / Float32(Float32(1.0) + Float32(c - Float32(exp(Float32(cosTheta * Float32(-cosTheta))) / Float32(Float32(cosTheta * sqrt(Float32(pi))) / Float32(Float32(-1.0) - Float32(cosTheta * Float32(Float32(-1.0) + Float32(cosTheta * Float32(-0.5)))))))))) end
function tmp = code(cosTheta, c) tmp = single(1.0) / (single(1.0) + (c - (exp((cosTheta * -cosTheta)) / ((cosTheta * sqrt(single(pi))) / (single(-1.0) - (cosTheta * (single(-1.0) + (cosTheta * single(-0.5))))))))); end
\begin{array}{l}
\\
\frac{1}{1 + \left(c - \frac{e^{cosTheta \cdot \left(-cosTheta\right)}}{\frac{cosTheta \cdot \sqrt{\pi}}{-1 - cosTheta \cdot \left(-1 + cosTheta \cdot -0.5\right)}}\right)}
\end{array}
Initial program 98.0%
associate-+l+98.0%
+-commutative98.0%
fma-define98.0%
Simplified98.7%
associate-/l/98.5%
clear-num98.6%
inv-pow98.6%
+-commutative98.6%
fma-define98.6%
Applied egg-rr98.6%
fma-undefine98.6%
unpow-198.6%
associate-/r/98.7%
pow-exp98.7%
distribute-lft-neg-out98.7%
pow298.7%
Applied egg-rr98.7%
+-commutative98.7%
associate-*l/98.7%
neg-mul-198.7%
*-lft-identity98.7%
neg-mul-198.7%
associate-*l/98.7%
*-commutative98.7%
Simplified98.7%
unpow298.7%
Applied egg-rr98.7%
Taylor expanded in cosTheta around 0 97.5%
Final simplification97.5%
(FPCore (cosTheta c)
:precision binary32
(/
1.0
(+
1.0
(+
c
(/
(exp (* cosTheta (- cosTheta)))
(/ (* cosTheta (sqrt PI)) (- 1.0 cosTheta)))))))
float code(float cosTheta, float c) {
return 1.0f / (1.0f + (c + (expf((cosTheta * -cosTheta)) / ((cosTheta * sqrtf(((float) M_PI))) / (1.0f - cosTheta)))));
}
function code(cosTheta, c) return Float32(Float32(1.0) / Float32(Float32(1.0) + Float32(c + Float32(exp(Float32(cosTheta * Float32(-cosTheta))) / Float32(Float32(cosTheta * sqrt(Float32(pi))) / Float32(Float32(1.0) - cosTheta)))))) end
function tmp = code(cosTheta, c) tmp = single(1.0) / (single(1.0) + (c + (exp((cosTheta * -cosTheta)) / ((cosTheta * sqrt(single(pi))) / (single(1.0) - cosTheta))))); end
\begin{array}{l}
\\
\frac{1}{1 + \left(c + \frac{e^{cosTheta \cdot \left(-cosTheta\right)}}{\frac{cosTheta \cdot \sqrt{\pi}}{1 - cosTheta}}\right)}
\end{array}
Initial program 98.0%
associate-+l+98.0%
+-commutative98.0%
fma-define98.0%
Simplified98.7%
associate-/l/98.5%
clear-num98.6%
inv-pow98.6%
+-commutative98.6%
fma-define98.6%
Applied egg-rr98.6%
fma-undefine98.6%
unpow-198.6%
associate-/r/98.7%
pow-exp98.7%
distribute-lft-neg-out98.7%
pow298.7%
Applied egg-rr98.7%
+-commutative98.7%
associate-*l/98.7%
neg-mul-198.7%
*-lft-identity98.7%
neg-mul-198.7%
associate-*l/98.7%
*-commutative98.7%
Simplified98.7%
unpow298.7%
Applied egg-rr98.7%
Taylor expanded in cosTheta around 0 96.8%
mul-1-neg96.8%
sub-neg96.8%
Simplified96.8%
Final simplification96.8%
(FPCore (cosTheta c) :precision binary32 (* cosTheta (+ (sqrt PI) (* cosTheta (* PI (- -1.0 (- c (sqrt (/ 1.0 PI)))))))))
float code(float cosTheta, float c) {
return cosTheta * (sqrtf(((float) M_PI)) + (cosTheta * (((float) M_PI) * (-1.0f - (c - sqrtf((1.0f / ((float) M_PI))))))));
}
function code(cosTheta, c) return Float32(cosTheta * Float32(sqrt(Float32(pi)) + Float32(cosTheta * Float32(Float32(pi) * Float32(Float32(-1.0) - Float32(c - sqrt(Float32(Float32(1.0) / Float32(pi))))))))) end
function tmp = code(cosTheta, c) tmp = cosTheta * (sqrt(single(pi)) + (cosTheta * (single(pi) * (single(-1.0) - (c - sqrt((single(1.0) / single(pi)))))))); end
\begin{array}{l}
\\
cosTheta \cdot \left(\sqrt{\pi} + cosTheta \cdot \left(\pi \cdot \left(-1 - \left(c - \sqrt{\frac{1}{\pi}}\right)\right)\right)\right)
\end{array}
Initial program 98.0%
associate-+l+98.0%
+-commutative98.0%
fma-define98.0%
Simplified98.7%
Taylor expanded in cosTheta around 0 96.6%
associate-*r*96.6%
mul-1-neg96.6%
mul-1-neg96.6%
Simplified96.6%
Final simplification96.6%
(FPCore (cosTheta c) :precision binary32 (* cosTheta (+ (sqrt PI) (* (* cosTheta PI) (+ (pow PI -0.5) (- -1.0 c))))))
float code(float cosTheta, float c) {
return cosTheta * (sqrtf(((float) M_PI)) + ((cosTheta * ((float) M_PI)) * (powf(((float) M_PI), -0.5f) + (-1.0f - c))));
}
function code(cosTheta, c) return Float32(cosTheta * Float32(sqrt(Float32(pi)) + Float32(Float32(cosTheta * Float32(pi)) * Float32((Float32(pi) ^ Float32(-0.5)) + Float32(Float32(-1.0) - c))))) end
function tmp = code(cosTheta, c) tmp = cosTheta * (sqrt(single(pi)) + ((cosTheta * single(pi)) * ((single(pi) ^ single(-0.5)) + (single(-1.0) - c)))); end
\begin{array}{l}
\\
cosTheta \cdot \left(\sqrt{\pi} + \left(cosTheta \cdot \pi\right) \cdot \left({\pi}^{-0.5} + \left(-1 - c\right)\right)\right)
\end{array}
Initial program 98.0%
associate-+l+98.0%
+-commutative98.0%
fma-define98.0%
Simplified98.7%
Taylor expanded in cosTheta around 0 96.6%
mul-1-neg96.6%
unsub-neg96.6%
associate-*r*96.6%
associate-+r+96.6%
mul-1-neg96.6%
unsub-neg96.6%
Simplified96.6%
associate--l+96.6%
pow1/296.6%
inv-pow96.6%
pow-pow96.6%
metadata-eval96.6%
Applied egg-rr96.6%
associate-+r-96.6%
Simplified96.6%
Final simplification96.6%
(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 98.0%
associate-+l+98.0%
+-commutative98.0%
fma-define98.0%
Simplified98.7%
Taylor expanded in cosTheta around 0 96.6%
mul-1-neg96.6%
unsub-neg96.6%
associate-*r*96.6%
associate-+r+96.6%
mul-1-neg96.6%
unsub-neg96.6%
Simplified96.6%
Taylor expanded in c around 0 96.5%
Final simplification96.5%
(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 98.0%
associate-+l+98.0%
+-commutative98.0%
fma-define98.0%
Simplified98.7%
Taylor expanded in cosTheta around 0 95.9%
mul-1-neg95.9%
Simplified95.9%
Taylor expanded in cosTheta around inf 95.9%
associate--l+95.9%
sub-neg95.9%
mul-1-neg95.9%
+-commutative95.9%
distribute-rgt-out95.9%
Simplified95.9%
(FPCore (cosTheta c) :precision binary32 (/ 1.0 (+ 1.0 (* (sqrt (/ 1.0 PI)) (+ -1.0 (/ 1.0 cosTheta))))))
float code(float cosTheta, float c) {
return 1.0f / (1.0f + (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(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) + (sqrt((single(1.0) / single(pi))) * (single(-1.0) + (single(1.0) / cosTheta)))); end
\begin{array}{l}
\\
\frac{1}{1 + \sqrt{\frac{1}{\pi}} \cdot \left(-1 + \frac{1}{cosTheta}\right)}
\end{array}
Initial program 98.0%
associate-+l+98.0%
+-commutative98.0%
fma-define98.0%
Simplified98.7%
Taylor expanded in cosTheta around 0 95.9%
mul-1-neg95.9%
Simplified95.9%
Taylor expanded in c around 0 95.8%
associate--l+95.8%
sub-neg95.8%
mul-1-neg95.8%
+-commutative95.8%
distribute-rgt-out95.8%
Simplified95.8%
(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 98.0%
associate-+l+98.0%
+-commutative98.0%
fma-define98.0%
Simplified98.7%
associate-/l/98.5%
clear-num98.6%
inv-pow98.6%
+-commutative98.6%
fma-define98.6%
Applied egg-rr98.6%
Taylor expanded in cosTheta around 0 94.5%
(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 98.0%
associate-+l+98.0%
+-commutative98.0%
fma-define98.0%
Simplified98.7%
Taylor expanded in c around inf 10.4%
Taylor expanded in c around 0 10.4%
mul-1-neg10.4%
unsub-neg10.4%
Simplified10.4%
Taylor expanded in c around 0 10.4%
herbie shell --seed 2024186
(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))))))