
(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 c)
(/
(* (/ 1.0 cosTheta) (pow (exp (- cosTheta)) cosTheta))
(sqrt (/ PI (+ 1.0 (* cosTheta -2.0))))))))
float code(float cosTheta, float c) {
return 1.0f / ((1.0f + c) + (((1.0f / cosTheta) * powf(expf(-cosTheta), cosTheta)) / sqrtf((((float) M_PI) / (1.0f + (cosTheta * -2.0f))))));
}
function code(cosTheta, c) return Float32(Float32(1.0) / Float32(Float32(Float32(1.0) + c) + Float32(Float32(Float32(Float32(1.0) / cosTheta) * (exp(Float32(-cosTheta)) ^ cosTheta)) / sqrt(Float32(Float32(pi) / Float32(Float32(1.0) + Float32(cosTheta * Float32(-2.0)))))))) end
function tmp = code(cosTheta, c) tmp = single(1.0) / ((single(1.0) + c) + (((single(1.0) / cosTheta) * (exp(-cosTheta) ^ cosTheta)) / sqrt((single(pi) / (single(1.0) + (cosTheta * single(-2.0))))))); end
\begin{array}{l}
\\
\frac{1}{\left(1 + c\right) + \frac{\frac{1}{cosTheta} \cdot {\left(e^{-cosTheta}\right)}^{cosTheta}}{\sqrt{\frac{\pi}{1 + cosTheta \cdot -2}}}}
\end{array}
Initial program 98.1%
frac-times98.5%
*-un-lft-identity98.5%
associate--r+98.5%
associate-/l/98.6%
clear-num98.6%
Applied egg-rr98.6%
add-sqr-sqrt97.7%
associate-/r/97.7%
associate-/r/97.6%
Applied egg-rr97.6%
*-un-lft-identity97.6%
add-sqr-sqrt98.4%
*-commutative98.4%
sqrt-undiv98.6%
Applied egg-rr98.6%
*-lft-identity98.6%
associate-/r*98.6%
count-298.6%
cancel-sign-sub-inv98.6%
metadata-eval98.6%
Simplified98.6%
*-un-lft-identity98.6%
associate-+l+98.6%
associate-*l/98.7%
exp-prod98.7%
*-commutative98.7%
Applied egg-rr98.7%
*-lft-identity98.7%
associate-+r+98.7%
Simplified98.7%
Final simplification98.7%
(FPCore (cosTheta c)
:precision binary32
(/
1.0
(+
1.0
(+
c
(/
(+
(+ (* cosTheta -1.5) (+ (/ 1.0 cosTheta) (* 0.5 (pow cosTheta 2.0))))
-1.0)
(sqrt PI))))))
float code(float cosTheta, float c) {
return 1.0f / (1.0f + (c + ((((cosTheta * -1.5f) + ((1.0f / cosTheta) + (0.5f * powf(cosTheta, 2.0f)))) + -1.0f) / sqrtf(((float) M_PI)))));
}
function code(cosTheta, c) return Float32(Float32(1.0) / Float32(Float32(1.0) + Float32(c + Float32(Float32(Float32(Float32(cosTheta * Float32(-1.5)) + Float32(Float32(Float32(1.0) / cosTheta) + Float32(Float32(0.5) * (cosTheta ^ Float32(2.0))))) + Float32(-1.0)) / sqrt(Float32(pi)))))) end
function tmp = code(cosTheta, c) tmp = single(1.0) / (single(1.0) + (c + ((((cosTheta * single(-1.5)) + ((single(1.0) / cosTheta) + (single(0.5) * (cosTheta ^ single(2.0))))) + single(-1.0)) / sqrt(single(pi))))); end
\begin{array}{l}
\\
\frac{1}{1 + \left(c + \frac{\left(cosTheta \cdot -1.5 + \left(\frac{1}{cosTheta} + 0.5 \cdot {cosTheta}^{2}\right)\right) + -1}{\sqrt{\pi}}\right)}
\end{array}
Initial program 98.1%
associate-+l+98.1%
associate-*l*98.1%
associate-*l/98.6%
*-lft-identity98.6%
Simplified98.5%
Taylor expanded in cosTheta around 0 97.6%
Final simplification97.6%
(FPCore (cosTheta c)
:precision binary32
(/
1.0
(+
(+ 1.0 c)
(*
(exp (* cosTheta (- cosTheta)))
(/ 1.0 (* cosTheta (sqrt (/ PI (+ 1.0 (* cosTheta -2.0))))))))))
float code(float cosTheta, float c) {
return 1.0f / ((1.0f + c) + (expf((cosTheta * -cosTheta)) * (1.0f / (cosTheta * sqrtf((((float) M_PI) / (1.0f + (cosTheta * -2.0f))))))));
}
function code(cosTheta, c) return Float32(Float32(1.0) / Float32(Float32(Float32(1.0) + c) + Float32(exp(Float32(cosTheta * Float32(-cosTheta))) * Float32(Float32(1.0) / Float32(cosTheta * sqrt(Float32(Float32(pi) / Float32(Float32(1.0) + Float32(cosTheta * Float32(-2.0)))))))))) end
function tmp = code(cosTheta, c) tmp = single(1.0) / ((single(1.0) + c) + (exp((cosTheta * -cosTheta)) * (single(1.0) / (cosTheta * sqrt((single(pi) / (single(1.0) + (cosTheta * single(-2.0))))))))); end
\begin{array}{l}
\\
\frac{1}{\left(1 + c\right) + e^{cosTheta \cdot \left(-cosTheta\right)} \cdot \frac{1}{cosTheta \cdot \sqrt{\frac{\pi}{1 + cosTheta \cdot -2}}}}
\end{array}
Initial program 98.1%
frac-times98.5%
*-un-lft-identity98.5%
associate--r+98.5%
associate-/l/98.6%
clear-num98.6%
Applied egg-rr98.6%
add-sqr-sqrt97.7%
associate-/r/97.7%
associate-/r/97.6%
Applied egg-rr97.6%
pow297.6%
*-commutative97.6%
sqrt-undiv97.6%
Applied egg-rr97.6%
unpow297.6%
rem-square-sqrt98.6%
sub-neg98.6%
count-298.6%
*-commutative98.6%
distribute-rgt-neg-in98.6%
metadata-eval98.6%
Simplified98.6%
Final simplification98.6%
(FPCore (cosTheta c)
:precision binary32
(/
1.0
(+
(+ 1.0 c)
(*
(/ (/ 1.0 cosTheta) (sqrt (/ PI (+ 1.0 (* cosTheta -2.0)))))
(exp (* cosTheta (- cosTheta)))))))
float code(float cosTheta, float c) {
return 1.0f / ((1.0f + c) + (((1.0f / cosTheta) / sqrtf((((float) M_PI) / (1.0f + (cosTheta * -2.0f))))) * expf((cosTheta * -cosTheta))));
}
function code(cosTheta, c) return Float32(Float32(1.0) / Float32(Float32(Float32(1.0) + c) + Float32(Float32(Float32(Float32(1.0) / cosTheta) / sqrt(Float32(Float32(pi) / Float32(Float32(1.0) + Float32(cosTheta * Float32(-2.0)))))) * exp(Float32(cosTheta * Float32(-cosTheta)))))) end
function tmp = code(cosTheta, c) tmp = single(1.0) / ((single(1.0) + c) + (((single(1.0) / cosTheta) / sqrt((single(pi) / (single(1.0) + (cosTheta * single(-2.0)))))) * exp((cosTheta * -cosTheta)))); end
\begin{array}{l}
\\
\frac{1}{\left(1 + c\right) + \frac{\frac{1}{cosTheta}}{\sqrt{\frac{\pi}{1 + cosTheta \cdot -2}}} \cdot e^{cosTheta \cdot \left(-cosTheta\right)}}
\end{array}
Initial program 98.1%
frac-times98.5%
*-un-lft-identity98.5%
associate--r+98.5%
associate-/l/98.6%
clear-num98.6%
Applied egg-rr98.6%
add-sqr-sqrt97.7%
associate-/r/97.7%
associate-/r/97.6%
Applied egg-rr97.6%
*-un-lft-identity97.6%
add-sqr-sqrt98.4%
*-commutative98.4%
sqrt-undiv98.6%
Applied egg-rr98.6%
*-lft-identity98.6%
associate-/r*98.6%
count-298.6%
cancel-sign-sub-inv98.6%
metadata-eval98.6%
Simplified98.6%
Final simplification98.6%
(FPCore (cosTheta c)
:precision binary32
(/
1.0
(+
(+ 1.0 c)
(/
(/ (sqrt (- 1.0 (+ cosTheta cosTheta))) cosTheta)
(* (sqrt PI) (+ 1.0 (* cosTheta cosTheta)))))))
float code(float cosTheta, float c) {
return 1.0f / ((1.0f + c) + ((sqrtf((1.0f - (cosTheta + cosTheta))) / cosTheta) / (sqrtf(((float) M_PI)) * (1.0f + (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))) / cosTheta) / Float32(sqrt(Float32(pi)) * Float32(Float32(1.0) + Float32(cosTheta * 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)) * (single(1.0) + (cosTheta * cosTheta))))); end
\begin{array}{l}
\\
\frac{1}{\left(1 + c\right) + \frac{\frac{\sqrt{1 - \left(cosTheta + cosTheta\right)}}{cosTheta}}{\sqrt{\pi} \cdot \left(1 + cosTheta \cdot cosTheta\right)}}
\end{array}
Initial program 98.1%
+-commutative98.1%
fma-def98.1%
associate-*l/98.6%
*-lft-identity98.6%
associate--l-98.6%
*-commutative98.6%
exp-prod98.6%
Simplified98.6%
fma-udef98.6%
pow-neg98.6%
div-inv98.6%
associate-/l/98.5%
pow-exp98.5%
Applied egg-rr98.5%
Taylor expanded in cosTheta around 0 97.5%
unpow297.5%
distribute-rgt1-in97.5%
Simplified97.5%
Final simplification97.5%
(FPCore (cosTheta c) :precision binary32 (/ 1.0 (+ 1.0 (+ c (/ (+ (+ (/ 1.0 cosTheta) (* cosTheta -1.5)) -1.0) (sqrt PI))))))
float code(float cosTheta, float c) {
return 1.0f / (1.0f + (c + ((((1.0f / cosTheta) + (cosTheta * -1.5f)) + -1.0f) / sqrtf(((float) M_PI)))));
}
function code(cosTheta, c) return Float32(Float32(1.0) / Float32(Float32(1.0) + Float32(c + Float32(Float32(Float32(Float32(Float32(1.0) / cosTheta) + Float32(cosTheta * Float32(-1.5))) + Float32(-1.0)) / sqrt(Float32(pi)))))) end
function tmp = code(cosTheta, c) tmp = single(1.0) / (single(1.0) + (c + ((((single(1.0) / cosTheta) + (cosTheta * single(-1.5))) + single(-1.0)) / sqrt(single(pi))))); end
\begin{array}{l}
\\
\frac{1}{1 + \left(c + \frac{\left(\frac{1}{cosTheta} + cosTheta \cdot -1.5\right) + -1}{\sqrt{\pi}}\right)}
\end{array}
Initial program 98.1%
associate-+l+98.1%
associate-*l*98.1%
associate-*l/98.6%
*-lft-identity98.6%
Simplified98.5%
Taylor expanded in cosTheta around 0 96.9%
Final simplification96.9%
(FPCore (cosTheta c) :precision binary32 (/ 1.0 (+ (+ 1.0 c) (* (sqrt (/ 1.0 PI)) (+ (/ 1.0 cosTheta) -1.0)))))
float code(float cosTheta, float c) {
return 1.0f / ((1.0f + c) + (sqrtf((1.0f / ((float) M_PI))) * ((1.0f / cosTheta) + -1.0f)));
}
function code(cosTheta, c) return Float32(Float32(1.0) / Float32(Float32(Float32(1.0) + c) + Float32(sqrt(Float32(Float32(1.0) / Float32(pi))) * Float32(Float32(Float32(1.0) / cosTheta) + Float32(-1.0))))) end
function tmp = code(cosTheta, c) tmp = single(1.0) / ((single(1.0) + c) + (sqrt((single(1.0) / single(pi))) * ((single(1.0) / cosTheta) + single(-1.0)))); end
\begin{array}{l}
\\
\frac{1}{\left(1 + c\right) + \sqrt{\frac{1}{\pi}} \cdot \left(\frac{1}{cosTheta} + -1\right)}
\end{array}
Initial program 98.1%
+-commutative98.1%
fma-def98.1%
associate-*l/98.6%
*-lft-identity98.6%
associate--l-98.6%
*-commutative98.6%
exp-prod98.6%
Simplified98.6%
Taylor expanded in cosTheta around 0 94.7%
associate-+r+94.7%
+-commutative94.7%
distribute-rgt-out94.7%
Simplified94.7%
Final simplification94.7%
(FPCore (cosTheta c) :precision binary32 (/ 1.0 (+ 1.0 (* (sqrt (/ 1.0 PI)) (+ (/ 1.0 cosTheta) -1.0)))))
float code(float cosTheta, float c) {
return 1.0f / (1.0f + (sqrtf((1.0f / ((float) M_PI))) * ((1.0f / cosTheta) + -1.0f)));
}
function code(cosTheta, c) return Float32(Float32(1.0) / Float32(Float32(1.0) + Float32(sqrt(Float32(Float32(1.0) / Float32(pi))) * Float32(Float32(Float32(1.0) / cosTheta) + Float32(-1.0))))) end
function tmp = code(cosTheta, c) tmp = single(1.0) / (single(1.0) + (sqrt((single(1.0) / single(pi))) * ((single(1.0) / cosTheta) + single(-1.0)))); end
\begin{array}{l}
\\
\frac{1}{1 + \sqrt{\frac{1}{\pi}} \cdot \left(\frac{1}{cosTheta} + -1\right)}
\end{array}
Initial program 98.1%
associate-*l*98.1%
*-lft-identity98.1%
associate-*r*98.1%
*-lft-identity98.1%
associate--l-98.0%
*-commutative98.0%
Simplified98.0%
Taylor expanded in cosTheta around 0 96.4%
Taylor expanded in cosTheta around 0 96.4%
associate--l+96.4%
unpow296.4%
sub-neg96.4%
fma-def96.4%
metadata-eval96.4%
Simplified96.4%
Taylor expanded in c around 0 96.3%
Taylor expanded in cosTheta around 0 94.6%
Final simplification94.6%
(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-def98.1%
associate-*l/98.6%
*-lft-identity98.6%
associate--l-98.6%
*-commutative98.6%
exp-prod98.6%
Simplified98.6%
Taylor expanded in cosTheta around 0 92.0%
Final simplification92.0%
(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 98.1%
+-commutative98.1%
fma-def98.1%
associate-*l/98.6%
*-lft-identity98.6%
associate--l-98.6%
*-commutative98.6%
exp-prod98.6%
Simplified98.6%
Taylor expanded in cosTheta around inf 10.9%
Taylor expanded in c around 0 10.9%
+-commutative10.9%
mul-1-neg10.9%
unsub-neg10.9%
Simplified10.9%
Final simplification10.9%
(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 98.1%
+-commutative98.1%
fma-def98.1%
associate-*l/98.6%
*-lft-identity98.6%
associate--l-98.6%
*-commutative98.6%
exp-prod98.6%
Simplified98.6%
Taylor expanded in cosTheta around inf 10.9%
Taylor expanded in c around 0 10.9%
Final simplification10.9%
herbie shell --seed 2023242
(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))))))