
(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
(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 98.0%
associate-+l+98.0%
+-commutative98.0%
fma-define98.0%
Simplified98.6%
Final simplification98.6%
(FPCore (cosTheta c)
:precision binary32
(/
1.0
(+
1.0
(+
c
(*
(sqrt (/ (+ 1.0 (* cosTheta -2.0)) PI))
(/ (exp (- (pow cosTheta 2.0))) cosTheta))))))
float code(float cosTheta, float c) {
return 1.0f / (1.0f + (c + (sqrtf(((1.0f + (cosTheta * -2.0f)) / ((float) M_PI))) * (expf(-powf(cosTheta, 2.0f)) / cosTheta))));
}
function code(cosTheta, c) return Float32(Float32(1.0) / Float32(Float32(1.0) + Float32(c + Float32(sqrt(Float32(Float32(Float32(1.0) + Float32(cosTheta * Float32(-2.0))) / Float32(pi))) * Float32(exp(Float32(-(cosTheta ^ Float32(2.0)))) / cosTheta))))) end
function tmp = code(cosTheta, c) tmp = single(1.0) / (single(1.0) + (c + (sqrt(((single(1.0) + (cosTheta * single(-2.0))) / single(pi))) * (exp(-(cosTheta ^ single(2.0))) / cosTheta)))); end
\begin{array}{l}
\\
\frac{1}{1 + \left(c + \sqrt{\frac{1 + cosTheta \cdot -2}{\pi}} \cdot \frac{e^{-{cosTheta}^{2}}}{cosTheta}\right)}
\end{array}
Initial program 98.0%
associate-+l+98.0%
+-commutative98.0%
fma-define98.0%
Simplified98.6%
Taylor expanded in c around 0 98.2%
Final simplification98.2%
(FPCore (cosTheta c)
:precision binary32
(/
1.0
(+
1.0
(*
(sqrt (/ (+ 1.0 (* cosTheta -2.0)) PI))
(/ (exp (- (pow cosTheta 2.0))) cosTheta)))))
float code(float cosTheta, float c) {
return 1.0f / (1.0f + (sqrtf(((1.0f + (cosTheta * -2.0f)) / ((float) M_PI))) * (expf(-powf(cosTheta, 2.0f)) / 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(exp(Float32(-(cosTheta ^ Float32(2.0)))) / cosTheta)))) end
function tmp = code(cosTheta, c) tmp = single(1.0) / (single(1.0) + (sqrt(((single(1.0) + (cosTheta * single(-2.0))) / single(pi))) * (exp(-(cosTheta ^ single(2.0))) / cosTheta))); end
\begin{array}{l}
\\
\frac{1}{1 + \sqrt{\frac{1 + cosTheta \cdot -2}{\pi}} \cdot \frac{e^{-{cosTheta}^{2}}}{cosTheta}}
\end{array}
Initial program 98.0%
add-cube-cbrt98.0%
cbrt-unprod98.0%
frac-times98.0%
metadata-eval98.0%
add-sqr-sqrt98.0%
inv-pow98.0%
sqrt-pow298.0%
metadata-eval98.0%
Applied egg-rr98.0%
associate-*r/98.0%
cbrt-unprod97.9%
inv-pow97.9%
metadata-eval97.9%
pow-prod-up97.9%
add-cbrt-cube97.9%
Applied egg-rr97.9%
Taylor expanded in c around 0 97.8%
*-commutative97.8%
cancel-sign-sub-inv97.8%
metadata-eval97.8%
neg-mul-197.8%
Simplified97.8%
Final simplification97.8%
(FPCore (cosTheta c)
:precision binary32
(/
1.0
(+
1.0
(+
c
(*
(sqrt (* cosTheta (- (/ 1.0 (* cosTheta PI)) (/ 2.0 PI))))
(* (- 1.0 (pow cosTheta 2.0)) (/ 1.0 cosTheta)))))))
float code(float cosTheta, float c) {
return 1.0f / (1.0f + (c + (sqrtf((cosTheta * ((1.0f / (cosTheta * ((float) M_PI))) - (2.0f / ((float) M_PI))))) * ((1.0f - powf(cosTheta, 2.0f)) * (1.0f / cosTheta)))));
}
function code(cosTheta, c) return Float32(Float32(1.0) / Float32(Float32(1.0) + Float32(c + Float32(sqrt(Float32(cosTheta * Float32(Float32(Float32(1.0) / Float32(cosTheta * Float32(pi))) - Float32(Float32(2.0) / Float32(pi))))) * Float32(Float32(Float32(1.0) - (cosTheta ^ Float32(2.0))) * Float32(Float32(1.0) / cosTheta)))))) end
function tmp = code(cosTheta, c) tmp = single(1.0) / (single(1.0) + (c + (sqrt((cosTheta * ((single(1.0) / (cosTheta * single(pi))) - (single(2.0) / single(pi))))) * ((single(1.0) - (cosTheta ^ single(2.0))) * (single(1.0) / cosTheta))))); end
\begin{array}{l}
\\
\frac{1}{1 + \left(c + \sqrt{cosTheta \cdot \left(\frac{1}{cosTheta \cdot \pi} - \frac{2}{\pi}\right)} \cdot \left(\left(1 - {cosTheta}^{2}\right) \cdot \frac{1}{cosTheta}\right)\right)}
\end{array}
Initial program 98.0%
associate-+l+98.0%
+-commutative98.0%
fma-define98.0%
Simplified98.6%
Taylor expanded in c around 0 98.2%
Taylor expanded in cosTheta around inf 98.1%
*-commutative98.1%
associate-*r/98.1%
metadata-eval98.1%
Simplified98.1%
add-exp-log90.1%
*-commutative90.1%
log-prod89.9%
*-commutative89.9%
mul-1-neg89.9%
unpow289.9%
distribute-lft-neg-out89.9%
Applied egg-rr89.9%
exp-sum90.1%
rem-exp-log90.1%
*-commutative90.1%
Simplified90.1%
Taylor expanded in cosTheta around 0 89.1%
associate-*r*89.1%
neg-mul-189.1%
distribute-rgt1-in89.1%
exp-neg89.1%
rem-exp-log97.0%
Simplified97.0%
Final simplification97.0%
(FPCore (cosTheta c) :precision binary32 (* cosTheta (+ (sqrt PI) (* PI (* cosTheta (+ (sqrt (/ 1.0 PI)) (- -1.0 c)))))))
float code(float cosTheta, float c) {
return cosTheta * (sqrtf(((float) M_PI)) + (((float) M_PI) * (cosTheta * (sqrtf((1.0f / ((float) M_PI))) + (-1.0f - c)))));
}
function code(cosTheta, c) return Float32(cosTheta * Float32(sqrt(Float32(pi)) + Float32(Float32(pi) * Float32(cosTheta * Float32(sqrt(Float32(Float32(1.0) / Float32(pi))) + Float32(Float32(-1.0) - c)))))) end
function tmp = code(cosTheta, c) tmp = cosTheta * (sqrt(single(pi)) + (single(pi) * (cosTheta * (sqrt((single(1.0) / single(pi))) + (single(-1.0) - c))))); end
\begin{array}{l}
\\
cosTheta \cdot \left(\sqrt{\pi} + \pi \cdot \left(cosTheta \cdot \left(\sqrt{\frac{1}{\pi}} + \left(-1 - c\right)\right)\right)\right)
\end{array}
Initial program 98.0%
associate-+l+98.0%
+-commutative98.0%
fma-define98.0%
Simplified98.6%
Taylor expanded in cosTheta around 0 96.0%
mul-1-neg96.0%
unsub-neg96.0%
associate-*r*96.0%
*-commutative96.0%
associate-*l*96.0%
associate-+r+96.0%
mul-1-neg96.0%
unsub-neg96.0%
Simplified96.0%
Final simplification96.0%
(FPCore (cosTheta c)
:precision binary32
(/
1.0
(+
1.0
(+
c
(*
(sqrt (* cosTheta (- (/ 1.0 (* cosTheta PI)) (/ 2.0 PI))))
(/ 1.0 cosTheta))))))
float code(float cosTheta, float c) {
return 1.0f / (1.0f + (c + (sqrtf((cosTheta * ((1.0f / (cosTheta * ((float) M_PI))) - (2.0f / ((float) M_PI))))) * (1.0f / cosTheta))));
}
function code(cosTheta, c) return Float32(Float32(1.0) / Float32(Float32(1.0) + Float32(c + Float32(sqrt(Float32(cosTheta * Float32(Float32(Float32(1.0) / Float32(cosTheta * Float32(pi))) - Float32(Float32(2.0) / Float32(pi))))) * Float32(Float32(1.0) / cosTheta))))) end
function tmp = code(cosTheta, c) tmp = single(1.0) / (single(1.0) + (c + (sqrt((cosTheta * ((single(1.0) / (cosTheta * single(pi))) - (single(2.0) / single(pi))))) * (single(1.0) / cosTheta)))); end
\begin{array}{l}
\\
\frac{1}{1 + \left(c + \sqrt{cosTheta \cdot \left(\frac{1}{cosTheta \cdot \pi} - \frac{2}{\pi}\right)} \cdot \frac{1}{cosTheta}\right)}
\end{array}
Initial program 98.0%
associate-+l+98.0%
+-commutative98.0%
fma-define98.0%
Simplified98.6%
Taylor expanded in c around 0 98.2%
Taylor expanded in cosTheta around inf 98.1%
*-commutative98.1%
associate-*r/98.1%
metadata-eval98.1%
Simplified98.1%
add-exp-log90.1%
*-commutative90.1%
log-prod89.9%
*-commutative89.9%
mul-1-neg89.9%
unpow289.9%
distribute-lft-neg-out89.9%
Applied egg-rr89.9%
exp-sum90.1%
rem-exp-log90.1%
*-commutative90.1%
Simplified90.1%
Taylor expanded in cosTheta around 0 87.7%
exp-neg87.8%
rem-exp-log95.6%
Simplified95.6%
Final simplification95.6%
(FPCore (cosTheta c)
:precision binary32
(/
1.0
(+
1.0
(+
c
(*
(sqrt (/ 1.0 PI))
(+ (/ 1.0 cosTheta) (* cosTheta (/ -1.0 cosTheta))))))))
float code(float cosTheta, float c) {
return 1.0f / (1.0f + (c + (sqrtf((1.0f / ((float) M_PI))) * ((1.0f / cosTheta) + (cosTheta * (-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(Float32(1.0) / cosTheta) + Float32(cosTheta * 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) / cosTheta) + (cosTheta * (single(-1.0) / cosTheta)))))); end
\begin{array}{l}
\\
\frac{1}{1 + \left(c + \sqrt{\frac{1}{\pi}} \cdot \left(\frac{1}{cosTheta} + cosTheta \cdot \frac{-1}{cosTheta}\right)\right)}
\end{array}
Initial program 98.0%
associate-+l+98.0%
+-commutative98.0%
fma-define98.0%
Simplified98.6%
Taylor expanded in c around 0 98.2%
Taylor expanded in cosTheta around inf 98.1%
*-commutative98.1%
associate-*r/98.1%
metadata-eval98.1%
Simplified98.1%
add-exp-log90.1%
*-commutative90.1%
log-prod89.9%
*-commutative89.9%
mul-1-neg89.9%
unpow289.9%
distribute-lft-neg-out89.9%
Applied egg-rr89.9%
exp-sum90.1%
rem-exp-log90.1%
*-commutative90.1%
Simplified90.1%
Taylor expanded in cosTheta around 0 87.5%
+-commutative87.5%
*-commutative87.5%
associate-*r*87.5%
distribute-rgt-out87.5%
exp-neg87.6%
rem-exp-log95.4%
mul-1-neg95.4%
exp-neg95.4%
rem-exp-log95.4%
Simplified95.4%
Final simplification95.4%
(FPCore (cosTheta c) :precision binary32 (/ 1.0 (+ 1.0 (+ c (/ (* (sqrt (/ 1.0 PI)) (- 1.0 cosTheta)) cosTheta)))))
float code(float cosTheta, float c) {
return 1.0f / (1.0f + (c + ((sqrtf((1.0f / ((float) M_PI))) * (1.0f - cosTheta)) / cosTheta)));
}
function code(cosTheta, c) return Float32(Float32(1.0) / Float32(Float32(1.0) + Float32(c + Float32(Float32(sqrt(Float32(Float32(1.0) / Float32(pi))) * Float32(Float32(1.0) - cosTheta)) / cosTheta)))) end
function tmp = code(cosTheta, c) tmp = single(1.0) / (single(1.0) + (c + ((sqrt((single(1.0) / single(pi))) * (single(1.0) - cosTheta)) / cosTheta))); end
\begin{array}{l}
\\
\frac{1}{1 + \left(c + \frac{\sqrt{\frac{1}{\pi}} \cdot \left(1 - cosTheta\right)}{cosTheta}\right)}
\end{array}
Initial program 98.0%
associate-+l+98.0%
+-commutative98.0%
fma-define98.0%
Simplified98.6%
Taylor expanded in c around 0 98.2%
Taylor expanded in cosTheta around inf 98.1%
*-commutative98.1%
associate-*r/98.1%
metadata-eval98.1%
Simplified98.1%
Taylor expanded in cosTheta around 0 95.4%
associate-*r*95.4%
distribute-rgt1-in95.4%
mul-1-neg95.4%
Simplified95.4%
Final simplification95.4%
(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%
Simplified98.6%
Taylor expanded in c around 0 98.2%
Taylor expanded in cosTheta around 0 93.0%
Final simplification93.0%
(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 98.0%
associate-+l+98.0%
+-commutative98.0%
fma-define98.0%
Simplified98.6%
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 98.0%
associate-+l+98.0%
+-commutative98.0%
fma-define98.0%
Simplified98.6%
Taylor expanded in c around inf 10.7%
Taylor expanded in c around 0 10.7%
Final simplification10.7%
herbie shell --seed 2024131
(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))))))