
(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 13 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)
(/
(* (sqrt (- 1.0 (* 2.0 cosTheta))) (exp (- (pow cosTheta 2.0))))
(* cosTheta (sqrt PI))))))
float code(float cosTheta, float c) {
return 1.0f / ((1.0f + c) + ((sqrtf((1.0f - (2.0f * cosTheta))) * expf(-powf(cosTheta, 2.0f))) / (cosTheta * sqrtf(((float) M_PI)))));
}
function code(cosTheta, c) return Float32(Float32(1.0) / Float32(Float32(Float32(1.0) + c) + Float32(Float32(sqrt(Float32(Float32(1.0) - Float32(Float32(2.0) * cosTheta))) * exp(Float32(-(cosTheta ^ Float32(2.0))))) / Float32(cosTheta * sqrt(Float32(pi)))))) end
function tmp = code(cosTheta, c) tmp = single(1.0) / ((single(1.0) + c) + ((sqrt((single(1.0) - (single(2.0) * cosTheta))) * exp(-(cosTheta ^ single(2.0)))) / (cosTheta * sqrt(single(pi))))); end
\begin{array}{l}
\\
\frac{1}{\left(1 + c\right) + \frac{\sqrt{1 - 2 \cdot cosTheta} \cdot e^{-{cosTheta}^{2}}}{cosTheta \cdot \sqrt{\pi}}}
\end{array}
Initial program 97.8%
expm1-log1p-u90.1%
frac-times90.2%
*-un-lft-identity90.2%
associate--l-90.2%
*-commutative90.2%
Applied egg-rr90.2%
expm1-log1p-u98.3%
associate-*l/98.3%
count-298.3%
distribute-lft-neg-out98.3%
unpow298.3%
Applied egg-rr98.3%
(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 97.8%
frac-times98.4%
*-un-lft-identity98.4%
associate--l-98.3%
*-commutative98.3%
Applied egg-rr98.3%
Final simplification98.3%
(FPCore (cosTheta c)
:precision binary32
(/
1.0
(+
1.0
(*
(/ (exp (- (pow cosTheta 2.0))) cosTheta)
(sqrt (/ (- 1.0 (* 2.0 cosTheta)) PI))))))
float code(float cosTheta, float c) {
return 1.0f / (1.0f + ((expf(-powf(cosTheta, 2.0f)) / cosTheta) * sqrtf(((1.0f - (2.0f * cosTheta)) / ((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(Float32(2.0) * cosTheta)) / 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) - (single(2.0) * cosTheta)) / single(pi))))); end
\begin{array}{l}
\\
\frac{1}{1 + \frac{e^{-{cosTheta}^{2}}}{cosTheta} \cdot \sqrt{\frac{1 - 2 \cdot cosTheta}{\pi}}}
\end{array}
Initial program 97.8%
associate-+l+97.8%
*-commutative97.8%
exp-prod97.8%
Simplified97.8%
Applied egg-rr97.6%
Taylor expanded in c around 0 97.7%
(FPCore (cosTheta c)
:precision binary32
(/
1.0
(+
(+ 1.0 c)
(*
(exp (* cosTheta (- cosTheta)))
(/
(+ 1.0 (* cosTheta (+ (* cosTheta (- (* cosTheta -0.5) 0.5)) -1.0)))
(* cosTheta (sqrt PI)))))))
float code(float cosTheta, float c) {
return 1.0f / ((1.0f + c) + (expf((cosTheta * -cosTheta)) * ((1.0f + (cosTheta * ((cosTheta * ((cosTheta * -0.5f) - 0.5f)) + -1.0f))) / (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) + Float32(cosTheta * Float32(Float32(cosTheta * Float32(Float32(cosTheta * Float32(-0.5)) - Float32(0.5))) + Float32(-1.0)))) / 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 * ((cosTheta * single(-0.5)) - single(0.5))) + single(-1.0)))) / (cosTheta * sqrt(single(pi)))))); end
\begin{array}{l}
\\
\frac{1}{\left(1 + c\right) + e^{cosTheta \cdot \left(-cosTheta\right)} \cdot \frac{1 + cosTheta \cdot \left(cosTheta \cdot \left(cosTheta \cdot -0.5 - 0.5\right) + -1\right)}{cosTheta \cdot \sqrt{\pi}}}
\end{array}
Initial program 97.8%
frac-times98.4%
*-un-lft-identity98.4%
associate--l-98.3%
*-commutative98.3%
Applied egg-rr98.3%
Taylor expanded in cosTheta around 0 97.7%
Final simplification97.7%
(FPCore (cosTheta c)
:precision binary32
(/
1.0
(+
(+ 1.0 c)
(*
(exp (* cosTheta (- cosTheta)))
(/
(+ 1.0 (* cosTheta (+ (* cosTheta -0.5) -1.0)))
(* cosTheta (sqrt PI)))))))
float code(float cosTheta, float c) {
return 1.0f / ((1.0f + c) + (expf((cosTheta * -cosTheta)) * ((1.0f + (cosTheta * ((cosTheta * -0.5f) + -1.0f))) / (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) + Float32(cosTheta * Float32(Float32(cosTheta * Float32(-0.5)) + Float32(-1.0)))) / 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 * single(-0.5)) + single(-1.0)))) / (cosTheta * sqrt(single(pi)))))); end
\begin{array}{l}
\\
\frac{1}{\left(1 + c\right) + e^{cosTheta \cdot \left(-cosTheta\right)} \cdot \frac{1 + cosTheta \cdot \left(cosTheta \cdot -0.5 + -1\right)}{cosTheta \cdot \sqrt{\pi}}}
\end{array}
Initial program 97.8%
frac-times98.4%
*-un-lft-identity98.4%
associate--l-98.3%
*-commutative98.3%
Applied egg-rr98.3%
Taylor expanded in cosTheta around 0 97.2%
Final simplification97.2%
(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 97.8%
frac-times98.4%
*-un-lft-identity98.4%
associate--l-98.3%
*-commutative98.3%
Applied egg-rr98.3%
Taylor expanded in cosTheta around 0 96.2%
Simplified96.2%
Final simplification96.2%
(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 97.8%
associate-+l+97.8%
*-commutative97.8%
exp-prod97.8%
Simplified97.8%
Taylor expanded in cosTheta around 0 96.1%
mul-1-neg96.1%
unsub-neg96.1%
associate-*r*96.1%
mul-1-neg96.1%
unsub-neg96.1%
Simplified96.1%
Final simplification96.1%
(FPCore (cosTheta c) :precision binary32 (* cosTheta (+ (sqrt PI) (* (* cosTheta PI) (+ (pow PI -0.5) -1.0)))))
float code(float cosTheta, float c) {
return cosTheta * (sqrtf(((float) M_PI)) + ((cosTheta * ((float) M_PI)) * (powf(((float) M_PI), -0.5f) + -1.0f)));
}
function code(cosTheta, c) return Float32(cosTheta * Float32(sqrt(Float32(pi)) + Float32(Float32(cosTheta * Float32(pi)) * Float32((Float32(pi) ^ Float32(-0.5)) + Float32(-1.0))))) end
function tmp = code(cosTheta, c) tmp = cosTheta * (sqrt(single(pi)) + ((cosTheta * single(pi)) * ((single(pi) ^ single(-0.5)) + single(-1.0)))); end
\begin{array}{l}
\\
cosTheta \cdot \left(\sqrt{\pi} + \left(cosTheta \cdot \pi\right) \cdot \left({\pi}^{-0.5} + -1\right)\right)
\end{array}
Initial program 97.8%
+-commutative97.8%
fma-define97.8%
associate-*l/98.3%
*-lft-identity98.3%
sub-neg98.3%
associate--l+98.2%
unsub-neg98.2%
neg-mul-198.2%
neg-mul-198.2%
distribute-rgt-out98.2%
metadata-eval98.2%
*-commutative98.2%
exp-prod98.2%
Simplified98.2%
Taylor expanded in cosTheta around 0 95.8%
Taylor expanded in c around 0 95.3%
associate-*l/95.3%
+-commutative95.3%
*-commutative95.3%
fma-undefine95.3%
*-lft-identity95.3%
Simplified95.3%
Taylor expanded in cosTheta around 0 95.9%
mul-1-neg95.9%
unsub-neg95.9%
associate-*r*95.9%
mul-1-neg95.9%
unsub-neg95.9%
unpow1/295.9%
rem-exp-log95.9%
exp-neg95.9%
exp-prod95.9%
distribute-lft-neg-out95.9%
distribute-rgt-neg-in95.9%
metadata-eval95.9%
exp-to-pow95.9%
Simplified95.9%
Final simplification95.9%
(FPCore (cosTheta c) :precision binary32 (/ 1.0 (+ 1.0 (+ c (* (/ 1.0 cosTheta) (sqrt (/ (+ 1.0 (* cosTheta -2.0)) PI)))))))
float code(float cosTheta, float c) {
return 1.0f / (1.0f + (c + ((1.0f / 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(Float32(1.0) / 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 + ((single(1.0) / cosTheta) * sqrt(((single(1.0) + (cosTheta * single(-2.0))) / single(pi)))))); end
\begin{array}{l}
\\
\frac{1}{1 + \left(c + \frac{1}{cosTheta} \cdot \sqrt{\frac{1 + cosTheta \cdot -2}{\pi}}\right)}
\end{array}
Initial program 97.8%
+-commutative97.8%
fma-define97.8%
associate-*l/98.3%
*-lft-identity98.3%
sub-neg98.3%
associate--l+98.2%
unsub-neg98.2%
neg-mul-198.2%
neg-mul-198.2%
distribute-rgt-out98.2%
metadata-eval98.2%
*-commutative98.2%
exp-prod98.2%
Simplified98.2%
Taylor expanded in cosTheta around 0 95.8%
Taylor expanded in c around 0 95.5%
Final simplification95.5%
(FPCore (cosTheta c) :precision binary32 (/ 1.0 (+ 1.0 (/ (sqrt (+ (/ 1.0 PI) (* -2.0 (/ cosTheta PI)))) cosTheta))))
float code(float cosTheta, float c) {
return 1.0f / (1.0f + (sqrtf(((1.0f / ((float) M_PI)) + (-2.0f * (cosTheta / ((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(pi)) + Float32(Float32(-2.0) * Float32(cosTheta / Float32(pi))))) / cosTheta))) end
function tmp = code(cosTheta, c) tmp = single(1.0) / (single(1.0) + (sqrt(((single(1.0) / single(pi)) + (single(-2.0) * (cosTheta / single(pi))))) / cosTheta)); end
\begin{array}{l}
\\
\frac{1}{1 + \frac{\sqrt{\frac{1}{\pi} + -2 \cdot \frac{cosTheta}{\pi}}}{cosTheta}}
\end{array}
Initial program 97.8%
+-commutative97.8%
fma-define97.8%
associate-*l/98.3%
*-lft-identity98.3%
sub-neg98.3%
associate--l+98.2%
unsub-neg98.2%
neg-mul-198.2%
neg-mul-198.2%
distribute-rgt-out98.2%
metadata-eval98.2%
*-commutative98.2%
exp-prod98.2%
Simplified98.2%
Taylor expanded in cosTheta around 0 95.8%
Taylor expanded in c around 0 95.3%
associate-*l/95.3%
+-commutative95.3%
*-commutative95.3%
fma-undefine95.3%
*-lft-identity95.3%
Simplified95.3%
Taylor expanded in cosTheta around 0 95.3%
Final simplification95.3%
(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 97.8%
+-commutative97.8%
fma-define97.8%
associate-*l/98.3%
*-lft-identity98.3%
sub-neg98.3%
associate--l+98.2%
unsub-neg98.2%
neg-mul-198.2%
neg-mul-198.2%
distribute-rgt-out98.2%
metadata-eval98.2%
*-commutative98.2%
exp-prod98.2%
Simplified98.2%
Taylor expanded in cosTheta around 0 95.8%
Taylor expanded in c around 0 95.3%
associate-*l/95.3%
+-commutative95.3%
*-commutative95.3%
fma-undefine95.3%
*-lft-identity95.3%
Simplified95.3%
fma-undefine95.3%
Applied egg-rr95.3%
Final simplification95.3%
(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 97.8%
associate-+l+97.8%
*-commutative97.8%
exp-prod97.8%
Simplified97.8%
Taylor expanded in cosTheta around 0 93.5%
(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}
\\
\frac{1}{c}
\end{array}
Initial program 97.8%
associate-+l+97.8%
*-commutative97.8%
exp-prod97.8%
Simplified97.8%
Taylor expanded in c around inf 5.0%
herbie shell --seed 2024180
(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))))))