
(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 97.9%
associate-+l+97.9%
+-commutative97.9%
fma-define97.9%
Simplified98.4%
Final simplification98.4%
(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 97.9%
+-commutative97.9%
fma-define98.0%
associate-*l/98.4%
*-lft-identity98.4%
associate--l-98.4%
sub-neg98.4%
neg-mul-198.4%
distribute-lft-out98.4%
distribute-rgt-out98.4%
metadata-eval98.4%
distribute-lft-neg-out98.4%
distribute-rgt-neg-out98.4%
exp-prod98.4%
Simplified98.4%
Taylor expanded in c around 0 98.1%
Final simplification98.1%
(FPCore (cosTheta c)
:precision binary32
(/
1.0
(+
1.0
(+
c
(*
(/ (- 1.0 cosTheta) (* cosTheta (sqrt PI)))
(exp (- (pow cosTheta 2.0))))))))
float code(float cosTheta, float c) {
return 1.0f / (1.0f + (c + (((1.0f - cosTheta) / (cosTheta * sqrtf(((float) M_PI)))) * expf(-powf(cosTheta, 2.0f)))));
}
function code(cosTheta, c) return Float32(Float32(1.0) / Float32(Float32(1.0) + Float32(c + Float32(Float32(Float32(Float32(1.0) - cosTheta) / Float32(cosTheta * sqrt(Float32(pi)))) * exp(Float32(-(cosTheta ^ Float32(2.0)))))))) end
function tmp = code(cosTheta, c) tmp = single(1.0) / (single(1.0) + (c + (((single(1.0) - cosTheta) / (cosTheta * sqrt(single(pi)))) * exp(-(cosTheta ^ single(2.0)))))); end
\begin{array}{l}
\\
\frac{1}{1 + \left(c + \frac{1 - cosTheta}{cosTheta \cdot \sqrt{\pi}} \cdot e^{-{cosTheta}^{2}}\right)}
\end{array}
Initial program 97.9%
associate-+l+97.9%
+-commutative97.9%
fma-define97.9%
Simplified98.4%
Taylor expanded in cosTheta around 0 96.4%
mul-1-neg96.4%
unsub-neg96.4%
Simplified96.4%
fma-undefine96.4%
*-commutative96.4%
pow-exp96.4%
distribute-lft-neg-out96.4%
unpow296.4%
Applied egg-rr96.4%
Final simplification96.4%
(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 97.9%
Taylor expanded in c around 0 97.4%
Final simplification97.4%
(FPCore (cosTheta c) :precision binary32 (* cosTheta (+ (sqrt PI) (* PI (* cosTheta (+ -1.0 (- (sqrt (/ 1.0 PI)) c)))))))
float code(float cosTheta, float c) {
return cosTheta * (sqrtf(((float) M_PI)) + (((float) M_PI) * (cosTheta * (-1.0f + (sqrtf((1.0f / ((float) M_PI))) - c)))));
}
function code(cosTheta, c) return Float32(cosTheta * Float32(sqrt(Float32(pi)) + Float32(Float32(pi) * Float32(cosTheta * Float32(Float32(-1.0) + Float32(sqrt(Float32(Float32(1.0) / Float32(pi))) - c)))))) end
function tmp = code(cosTheta, c) tmp = cosTheta * (sqrt(single(pi)) + (single(pi) * (cosTheta * (single(-1.0) + (sqrt((single(1.0) / single(pi))) - c))))); end
\begin{array}{l}
\\
cosTheta \cdot \left(\sqrt{\pi} + \pi \cdot \left(cosTheta \cdot \left(-1 + \left(\sqrt{\frac{1}{\pi}} - c\right)\right)\right)\right)
\end{array}
Initial program 97.9%
associate-+l+97.9%
+-commutative97.9%
fma-define97.9%
Simplified98.4%
Taylor expanded in cosTheta around 0 96.2%
mul-1-neg96.2%
unsub-neg96.2%
*-commutative96.2%
associate-*l*96.2%
*-commutative96.2%
mul-1-neg96.2%
unsub-neg96.2%
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(Float32(-1.0) + 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(\left(-1 + \sqrt{\frac{1}{\pi}}\right) - c\right)\right)
\end{array}
Initial program 97.9%
associate-+l+97.9%
+-commutative97.9%
fma-define97.9%
Simplified98.4%
Taylor expanded in cosTheta around 0 96.4%
mul-1-neg96.4%
unsub-neg96.4%
Simplified96.4%
Taylor expanded in cosTheta around 0 95.8%
distribute-lft-out95.8%
distribute-rgt1-in95.8%
Simplified95.8%
Taylor expanded in cosTheta around 0 96.2%
distribute-rgt-in96.2%
associate-*r*96.2%
associate-+r+96.2%
mul-1-neg96.2%
sub-neg96.2%
associate-*r*96.2%
distribute-rgt-in96.2%
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(cosTheta * Float32(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} + cosTheta \cdot \left(\pi \cdot \left(-1 + \left(\sqrt{\frac{1}{\pi}} - c\right)\right)\right)\right)
\end{array}
Initial program 97.9%
associate-+l+97.9%
+-commutative97.9%
fma-define97.9%
Simplified98.4%
Taylor expanded in cosTheta around 0 96.2%
associate-*r*96.2%
mul-1-neg96.2%
mul-1-neg96.2%
Simplified96.2%
Final simplification96.2%
(FPCore (cosTheta c) :precision binary32 (/ 1.0 (- 1.0 (- (* (sqrt (/ 1.0 PI)) (+ (+ 1.0 cosTheta) (/ -1.0 cosTheta))) c))))
float code(float cosTheta, float c) {
return 1.0f / (1.0f - ((sqrtf((1.0f / ((float) M_PI))) * ((1.0f + cosTheta) + (-1.0f / cosTheta))) - c));
}
function code(cosTheta, c) return Float32(Float32(1.0) / Float32(Float32(1.0) - Float32(Float32(sqrt(Float32(Float32(1.0) / Float32(pi))) * Float32(Float32(Float32(1.0) + cosTheta) + Float32(Float32(-1.0) / cosTheta))) - c))) 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) / cosTheta))) - c)); end
\begin{array}{l}
\\
\frac{1}{1 - \left(\sqrt{\frac{1}{\pi}} \cdot \left(\left(1 + cosTheta\right) + \frac{-1}{cosTheta}\right) - c\right)}
\end{array}
Initial program 97.9%
associate-+l+97.9%
+-commutative97.9%
fma-define97.9%
Simplified98.4%
Taylor expanded in cosTheta around 0 96.4%
mul-1-neg96.4%
unsub-neg96.4%
Simplified96.4%
Taylor expanded in cosTheta around 0 95.8%
distribute-lft-out95.8%
distribute-rgt1-in95.8%
Simplified95.8%
Taylor expanded in c around inf 56.3%
associate-*r*56.3%
distribute-rgt-out56.3%
mul-1-neg56.3%
*-commutative56.3%
Simplified56.3%
Taylor expanded in c around 0 95.9%
Final simplification95.9%
(FPCore (cosTheta c) :precision binary32 (/ 1.0 (+ 1.0 (* (sqrt (/ 1.0 PI)) (+ (/ 1.0 cosTheta) (- -1.0 cosTheta))))))
float code(float cosTheta, float c) {
return 1.0f / (1.0f + (sqrtf((1.0f / ((float) M_PI))) * ((1.0f / cosTheta) + (-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(Float32(1.0) / cosTheta) + 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) / cosTheta) + (single(-1.0) - cosTheta)))); end
\begin{array}{l}
\\
\frac{1}{1 + \sqrt{\frac{1}{\pi}} \cdot \left(\frac{1}{cosTheta} + \left(-1 - cosTheta\right)\right)}
\end{array}
Initial program 97.9%
associate-+l+97.9%
+-commutative97.9%
fma-define97.9%
Simplified98.4%
Taylor expanded in cosTheta around 0 96.4%
mul-1-neg96.4%
unsub-neg96.4%
Simplified96.4%
Taylor expanded in cosTheta around 0 95.8%
distribute-lft-out95.8%
distribute-rgt1-in95.8%
Simplified95.8%
Taylor expanded in c around inf 56.3%
associate-*r*56.3%
distribute-rgt-out56.3%
mul-1-neg56.3%
*-commutative56.3%
Simplified56.3%
Taylor expanded in c around 0 95.6%
Final simplification95.6%
(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 97.9%
associate-*l/98.4%
*-un-lft-identity98.4%
sub-neg98.4%
sub-neg98.4%
add-sqr-sqrt-0.0%
sqrt-unprod93.0%
sqr-neg93.0%
sqrt-unprod93.0%
add-sqr-sqrt93.0%
add-sqr-sqrt-0.0%
sqrt-unprod92.5%
sqr-neg92.5%
sqrt-unprod92.5%
add-sqr-sqrt92.5%
Applied egg-rr92.5%
Taylor expanded in cosTheta around 0 93.5%
Final simplification93.5%
(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}
\\
1 - c
\end{array}
Initial program 97.9%
associate-+l+97.9%
+-commutative97.9%
fma-define97.9%
Simplified98.4%
Taylor expanded in cosTheta around 0 96.4%
mul-1-neg96.4%
unsub-neg96.4%
Simplified96.4%
Taylor expanded in c around inf 10.7%
Taylor expanded in c around 0 10.7%
mul-1-neg10.7%
unsub-neg10.7%
Simplified10.7%
Final simplification10.7%
(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 97.9%
associate-+l+97.9%
+-commutative97.9%
fma-define97.9%
Simplified98.4%
Taylor expanded in cosTheta around 0 96.4%
mul-1-neg96.4%
unsub-neg96.4%
Simplified96.4%
Taylor expanded in c around inf 10.7%
Taylor expanded in c around 0 10.7%
Final simplification10.7%
herbie shell --seed 2024079
(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))))))