
(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 10 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 (/ (* (sqrt PI) cosTheta) (sqrt (- (- 1.0 cosTheta) cosTheta))))
(exp (* cosTheta (- cosTheta)))))))
float code(float cosTheta, float c) {
return 1.0f / ((1.0f + c) + ((1.0f / ((sqrtf(((float) M_PI)) * cosTheta) / sqrtf(((1.0f - cosTheta) - cosTheta)))) * expf((cosTheta * -cosTheta))));
}
function code(cosTheta, c) return Float32(Float32(1.0) / Float32(Float32(Float32(1.0) + c) + Float32(Float32(Float32(1.0) / Float32(Float32(sqrt(Float32(pi)) * cosTheta) / sqrt(Float32(Float32(Float32(1.0) - cosTheta) - cosTheta)))) * exp(Float32(cosTheta * Float32(-cosTheta)))))) end
function tmp = code(cosTheta, c) tmp = single(1.0) / ((single(1.0) + c) + ((single(1.0) / ((sqrt(single(pi)) * cosTheta) / sqrt(((single(1.0) - cosTheta) - cosTheta)))) * exp((cosTheta * -cosTheta)))); end
\begin{array}{l}
\\
\frac{1}{\left(1 + c\right) + \frac{1}{\frac{\sqrt{\pi} \cdot cosTheta}{\sqrt{\left(1 - cosTheta\right) - cosTheta}}} \cdot e^{cosTheta \cdot \left(-cosTheta\right)}}
\end{array}
Initial program 98.0%
frac-times98.6%
*-un-lft-identity98.6%
clear-num98.6%
Applied egg-rr98.6%
Final simplification98.6%
(FPCore (cosTheta c)
:precision binary32
(/
1.0
(+
(+ 1.0 c)
(/
(sqrt (- (- 1.0 cosTheta) cosTheta))
(* (* (sqrt PI) cosTheta) (exp (* cosTheta cosTheta)))))))
float code(float cosTheta, float c) {
return 1.0f / ((1.0f + c) + (sqrtf(((1.0f - cosTheta) - cosTheta)) / ((sqrtf(((float) M_PI)) * cosTheta) * expf((cosTheta * cosTheta)))));
}
function code(cosTheta, c) return Float32(Float32(1.0) / Float32(Float32(Float32(1.0) + c) + Float32(sqrt(Float32(Float32(Float32(1.0) - cosTheta) - cosTheta)) / Float32(Float32(sqrt(Float32(pi)) * cosTheta) * exp(Float32(cosTheta * cosTheta)))))) end
function tmp = code(cosTheta, c) tmp = single(1.0) / ((single(1.0) + c) + (sqrt(((single(1.0) - cosTheta) - cosTheta)) / ((sqrt(single(pi)) * cosTheta) * exp((cosTheta * cosTheta))))); end
\begin{array}{l}
\\
\frac{1}{\left(1 + c\right) + \frac{\sqrt{\left(1 - cosTheta\right) - cosTheta}}{\left(\sqrt{\pi} \cdot cosTheta\right) \cdot e^{cosTheta \cdot cosTheta}}}
\end{array}
Initial program 98.0%
associate-*l*98.0%
*-commutative98.0%
exp-prod98.0%
Simplified98.0%
associate-*r*98.0%
pow-neg98.0%
pow-exp98.0%
div-inv98.0%
frac-times98.6%
*-un-lft-identity98.6%
associate-/l/98.6%
Applied egg-rr98.6%
Final simplification98.6%
(FPCore (cosTheta c)
:precision binary32
(/
1.0
(+
1.0
(+
c
(/
(+ (- 1.0 cosTheta) (* (* cosTheta cosTheta) -0.5))
(* (sqrt PI) (* cosTheta (exp (* cosTheta cosTheta)))))))))
float code(float cosTheta, float c) {
return 1.0f / (1.0f + (c + (((1.0f - cosTheta) + ((cosTheta * cosTheta) * -0.5f)) / (sqrtf(((float) M_PI)) * (cosTheta * expf((cosTheta * cosTheta)))))));
}
function code(cosTheta, c) return Float32(Float32(1.0) / Float32(Float32(1.0) + Float32(c + Float32(Float32(Float32(Float32(1.0) - cosTheta) + Float32(Float32(cosTheta * cosTheta) * Float32(-0.5))) / Float32(sqrt(Float32(pi)) * Float32(cosTheta * exp(Float32(cosTheta * cosTheta)))))))) end
function tmp = code(cosTheta, c) tmp = single(1.0) / (single(1.0) + (c + (((single(1.0) - cosTheta) + ((cosTheta * cosTheta) * single(-0.5))) / (sqrt(single(pi)) * (cosTheta * exp((cosTheta * cosTheta))))))); end
\begin{array}{l}
\\
\frac{1}{1 + \left(c + \frac{\left(1 - cosTheta\right) + \left(cosTheta \cdot cosTheta\right) \cdot -0.5}{\sqrt{\pi} \cdot \left(cosTheta \cdot e^{cosTheta \cdot cosTheta}\right)}\right)}
\end{array}
Initial program 98.0%
associate-+l+98.0%
associate-*l*98.0%
associate-*l/98.5%
*-lft-identity98.5%
associate-/r/98.5%
associate-/l/98.6%
Simplified98.6%
Taylor expanded in cosTheta around 0 97.9%
neg-mul-197.9%
associate-+r+97.9%
sub-neg97.9%
*-commutative97.9%
unpow297.9%
Simplified97.9%
Final simplification97.9%
(FPCore (cosTheta c)
:precision binary32
(/
1.0
(+
1.0
(*
(sqrt (/ (+ 1.0 (* cosTheta -2.0)) PI))
(/ 1.0 (* cosTheta (exp (* cosTheta cosTheta))))))))
float code(float cosTheta, float c) {
return 1.0f / (1.0f + (sqrtf(((1.0f + (cosTheta * -2.0f)) / ((float) M_PI))) * (1.0f / (cosTheta * expf((cosTheta * 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(Float32(1.0) / Float32(cosTheta * exp(Float32(cosTheta * cosTheta))))))) end
function tmp = code(cosTheta, c) tmp = single(1.0) / (single(1.0) + (sqrt(((single(1.0) + (cosTheta * single(-2.0))) / single(pi))) * (single(1.0) / (cosTheta * exp((cosTheta * cosTheta)))))); end
\begin{array}{l}
\\
\frac{1}{1 + \sqrt{\frac{1 + cosTheta \cdot -2}{\pi}} \cdot \frac{1}{cosTheta \cdot e^{cosTheta \cdot cosTheta}}}
\end{array}
Initial program 98.0%
associate-*l*98.0%
*-commutative98.0%
exp-prod98.0%
Simplified98.0%
associate-*r*98.0%
pow-neg98.0%
pow-exp98.0%
div-inv98.0%
frac-times98.6%
*-un-lft-identity98.6%
associate-/l/98.6%
Applied egg-rr98.6%
Taylor expanded in c around 0 97.8%
cancel-sign-sub-inv97.8%
metadata-eval97.8%
*-commutative97.8%
unpow297.8%
Simplified97.8%
Final simplification97.8%
(FPCore (cosTheta c)
:precision binary32
(/
1.0
(+
1.0
(+
c
(/
(- 1.0 cosTheta)
(* (sqrt PI) (* cosTheta (exp (* cosTheta cosTheta)))))))))
float code(float cosTheta, float c) {
return 1.0f / (1.0f + (c + ((1.0f - cosTheta) / (sqrtf(((float) M_PI)) * (cosTheta * expf((cosTheta * cosTheta)))))));
}
function code(cosTheta, c) return Float32(Float32(1.0) / Float32(Float32(1.0) + Float32(c + Float32(Float32(Float32(1.0) - cosTheta) / Float32(sqrt(Float32(pi)) * Float32(cosTheta * exp(Float32(cosTheta * cosTheta)))))))) end
function tmp = code(cosTheta, c) tmp = single(1.0) / (single(1.0) + (c + ((single(1.0) - cosTheta) / (sqrt(single(pi)) * (cosTheta * exp((cosTheta * cosTheta))))))); end
\begin{array}{l}
\\
\frac{1}{1 + \left(c + \frac{1 - cosTheta}{\sqrt{\pi} \cdot \left(cosTheta \cdot e^{cosTheta \cdot cosTheta}\right)}\right)}
\end{array}
Initial program 98.0%
associate-+l+98.0%
associate-*l*98.0%
associate-*l/98.5%
*-lft-identity98.5%
associate-/r/98.5%
associate-/l/98.6%
Simplified98.6%
Taylor expanded in cosTheta around 0 97.1%
neg-mul-197.1%
sub-neg97.1%
Simplified97.1%
Final simplification97.1%
(FPCore (cosTheta c) :precision binary32 (/ 1.0 (+ c (+ 1.0 (/ (+ -1.0 (/ 1.0 cosTheta)) (sqrt PI))))))
float code(float cosTheta, float c) {
return 1.0f / (c + (1.0f + ((-1.0f + (1.0f / cosTheta)) / sqrtf(((float) M_PI)))));
}
function code(cosTheta, c) return Float32(Float32(1.0) / Float32(c + Float32(Float32(1.0) + Float32(Float32(Float32(-1.0) + Float32(Float32(1.0) / cosTheta)) / sqrt(Float32(pi)))))) end
function tmp = code(cosTheta, c) tmp = single(1.0) / (c + (single(1.0) + ((single(-1.0) + (single(1.0) / cosTheta)) / sqrt(single(pi))))); end
\begin{array}{l}
\\
\frac{1}{c + \left(1 + \frac{-1 + \frac{1}{cosTheta}}{\sqrt{\pi}}\right)}
\end{array}
Initial program 98.0%
associate-+l+98.0%
associate-*l*98.0%
associate-*l/98.5%
*-lft-identity98.5%
associate-/r/98.5%
associate-/l/98.6%
Simplified98.6%
Taylor expanded in cosTheta around 0 96.2%
distribute-rgt-out96.2%
Simplified96.2%
*-un-lft-identity96.2%
sqrt-div96.2%
metadata-eval96.2%
Applied egg-rr96.2%
*-lft-identity96.2%
+-commutative96.2%
associate-+l+96.2%
associate-*l/96.6%
*-lft-identity96.6%
Simplified96.6%
Final simplification96.6%
(FPCore (cosTheta c) :precision binary32 (/ 1.0 (+ 1.0 (/ (+ -1.0 (/ 1.0 cosTheta)) (sqrt PI)))))
float code(float cosTheta, float c) {
return 1.0f / (1.0f + ((-1.0f + (1.0f / cosTheta)) / sqrtf(((float) M_PI))));
}
function code(cosTheta, c) return Float32(Float32(1.0) / Float32(Float32(1.0) + Float32(Float32(Float32(-1.0) + Float32(Float32(1.0) / cosTheta)) / sqrt(Float32(pi))))) end
function tmp = code(cosTheta, c) tmp = single(1.0) / (single(1.0) + ((single(-1.0) + (single(1.0) / cosTheta)) / sqrt(single(pi)))); end
\begin{array}{l}
\\
\frac{1}{1 + \frac{-1 + \frac{1}{cosTheta}}{\sqrt{\pi}}}
\end{array}
Initial program 98.0%
associate-+l+98.0%
associate-*l*98.0%
associate-*l/98.5%
*-lft-identity98.5%
associate-/r/98.5%
associate-/l/98.6%
Simplified98.6%
Taylor expanded in cosTheta around 0 96.2%
distribute-rgt-out96.2%
Simplified96.2%
Taylor expanded in c around 0 96.1%
sub-neg96.1%
metadata-eval96.1%
+-commutative96.1%
*-commutative96.1%
sqrt-div96.1%
metadata-eval96.1%
associate-*l/96.5%
*-un-lft-identity96.5%
+-commutative96.5%
Applied egg-rr96.5%
Final simplification96.5%
(FPCore (cosTheta c) :precision binary32 (* (sqrt PI) cosTheta))
float code(float cosTheta, float c) {
return sqrtf(((float) M_PI)) * cosTheta;
}
function code(cosTheta, c) return Float32(sqrt(Float32(pi)) * cosTheta) end
function tmp = code(cosTheta, c) tmp = sqrt(single(pi)) * cosTheta; end
\begin{array}{l}
\\
\sqrt{\pi} \cdot cosTheta
\end{array}
Initial program 98.0%
frac-times98.6%
*-un-lft-identity98.6%
clear-num98.6%
Applied egg-rr98.6%
Taylor expanded in cosTheta around 0 94.3%
Final simplification94.3%
(FPCore (cosTheta c) :precision binary32 (* c (- (* PI (* cosTheta cosTheta)))))
float code(float cosTheta, float c) {
return c * -(((float) M_PI) * (cosTheta * cosTheta));
}
function code(cosTheta, c) return Float32(c * Float32(-Float32(Float32(pi) * Float32(cosTheta * cosTheta)))) end
function tmp = code(cosTheta, c) tmp = c * -(single(pi) * (cosTheta * cosTheta)); end
\begin{array}{l}
\\
c \cdot \left(-\pi \cdot \left(cosTheta \cdot cosTheta\right)\right)
\end{array}
Initial program 98.0%
associate-+l+98.0%
associate-*l*98.0%
associate-*l/98.5%
*-lft-identity98.5%
associate-/r/98.5%
associate-/l/98.6%
Simplified98.6%
Taylor expanded in cosTheta around 0 96.8%
fma-def96.9%
associate-*r*96.9%
mul-1-neg96.9%
unpow296.9%
*-commutative96.9%
associate-+r+96.9%
+-commutative96.9%
mul-1-neg96.9%
Simplified96.9%
Taylor expanded in c around inf 10.6%
mul-1-neg10.6%
distribute-rgt-neg-in10.6%
*-commutative10.6%
unpow210.6%
Simplified10.6%
Final simplification10.6%
(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%
Taylor expanded in c around 0 97.7%
Taylor expanded in cosTheta around inf 10.4%
Final simplification10.4%
herbie shell --seed 2023279
(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))))))