
(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 (fma cosTheta -2.0 1.0)) (* cosTheta (sqrt PI)))
(pow (exp (- cosTheta)) cosTheta)
c))))
float code(float cosTheta, float c) {
return 1.0f / (1.0f + fmaf((sqrtf(fmaf(cosTheta, -2.0f, 1.0f)) / (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(fma(cosTheta, Float32(-2.0), Float32(1.0))) / Float32(cosTheta * sqrt(Float32(pi)))), (exp(Float32(-cosTheta)) ^ cosTheta), c))) end
\begin{array}{l}
\\
\frac{1}{1 + \mathsf{fma}\left(\frac{\sqrt{\mathsf{fma}\left(cosTheta, -2, 1\right)}}{cosTheta \cdot \sqrt{\pi}}, {\left(e^{-cosTheta}\right)}^{cosTheta}, c\right)}
\end{array}
Initial program 97.5%
associate-+l+97.5%
+-commutative97.5%
fma-def97.6%
Simplified98.6%
Final simplification98.6%
(FPCore (cosTheta c)
:precision binary32
(/
1.0
(+
(+ 1.0 c)
(/
(/ (sqrt (+ 1.0 (* cosTheta -2.0))) (* cosTheta (sqrt PI)))
(exp (* cosTheta cosTheta))))))
float code(float cosTheta, float c) {
return 1.0f / ((1.0f + c) + ((sqrtf((1.0f + (cosTheta * -2.0f))) / (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 * Float32(-2.0)))) / Float32(cosTheta * sqrt(Float32(pi)))) / exp(Float32(cosTheta * cosTheta))))) end
function tmp = code(cosTheta, c) tmp = single(1.0) / ((single(1.0) + c) + ((sqrt((single(1.0) + (cosTheta * single(-2.0)))) / (cosTheta * sqrt(single(pi)))) / exp((cosTheta * cosTheta)))); end
\begin{array}{l}
\\
\frac{1}{\left(1 + c\right) + \frac{\frac{\sqrt{1 + cosTheta \cdot -2}}{cosTheta \cdot \sqrt{\pi}}}{e^{cosTheta \cdot cosTheta}}}
\end{array}
Initial program 97.5%
distribute-lft-neg-out97.5%
exp-neg97.5%
associate-*r/97.5%
associate-/l*97.5%
/-rgt-identity97.5%
*-commutative97.5%
Simplified98.5%
Final simplification98.5%
(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 97.5%
associate-*l*97.6%
*-lft-identity97.6%
*-lft-identity97.6%
associate--l-97.5%
*-commutative97.5%
exp-prod97.5%
Simplified97.5%
Applied egg-rr98.3%
expm1-log1p-u90.1%
expm1-udef90.1%
associate-/r/90.1%
pow290.1%
rec-exp90.1%
pow290.1%
Applied egg-rr90.1%
expm1-def90.1%
expm1-log1p98.3%
Simplified98.3%
Taylor expanded in c around 0 97.1%
Final simplification97.1%
(FPCore (cosTheta c)
:precision binary32
(/
1.0
(+
(+ 1.0 c)
(*
(pow PI -0.5)
(+
(+ (* cosTheta -1.5) (+ (* (pow cosTheta 2.0) 0.5) (/ 1.0 cosTheta)))
-1.0)))))
float code(float cosTheta, float c) {
return 1.0f / ((1.0f + c) + (powf(((float) M_PI), -0.5f) * (((cosTheta * -1.5f) + ((powf(cosTheta, 2.0f) * 0.5f) + (1.0f / cosTheta))) + -1.0f)));
}
function code(cosTheta, c) return Float32(Float32(1.0) / Float32(Float32(Float32(1.0) + c) + Float32((Float32(pi) ^ Float32(-0.5)) * Float32(Float32(Float32(cosTheta * Float32(-1.5)) + Float32(Float32((cosTheta ^ Float32(2.0)) * Float32(0.5)) + Float32(Float32(1.0) / cosTheta))) + Float32(-1.0))))) end
function tmp = code(cosTheta, c) tmp = single(1.0) / ((single(1.0) + c) + ((single(pi) ^ single(-0.5)) * (((cosTheta * single(-1.5)) + (((cosTheta ^ single(2.0)) * single(0.5)) + (single(1.0) / cosTheta))) + single(-1.0)))); end
\begin{array}{l}
\\
\frac{1}{\left(1 + c\right) + {\pi}^{-0.5} \cdot \left(\left(cosTheta \cdot -1.5 + \left({cosTheta}^{2} \cdot 0.5 + \frac{1}{cosTheta}\right)\right) + -1\right)}
\end{array}
Initial program 97.5%
associate-*l*97.6%
*-lft-identity97.6%
*-lft-identity97.6%
associate--l-97.5%
*-commutative97.5%
exp-prod97.5%
Simplified97.5%
Taylor expanded in cosTheta around 0 96.6%
expm1-log1p-u96.6%
expm1-udef96.6%
pow1/296.6%
pow-flip96.6%
metadata-eval96.6%
Applied egg-rr96.6%
expm1-def96.6%
expm1-log1p96.6%
Simplified96.6%
Final simplification96.6%
(FPCore (cosTheta c)
:precision binary32
(/
1.0
(+
1.0
(*
(pow PI -0.5)
(+
(+ (* cosTheta -1.5) (+ (* (pow cosTheta 2.0) 0.5) (/ 1.0 cosTheta)))
-1.0)))))
float code(float cosTheta, float c) {
return 1.0f / (1.0f + (powf(((float) M_PI), -0.5f) * (((cosTheta * -1.5f) + ((powf(cosTheta, 2.0f) * 0.5f) + (1.0f / cosTheta))) + -1.0f)));
}
function code(cosTheta, c) return Float32(Float32(1.0) / Float32(Float32(1.0) + Float32((Float32(pi) ^ Float32(-0.5)) * Float32(Float32(Float32(cosTheta * Float32(-1.5)) + Float32(Float32((cosTheta ^ Float32(2.0)) * Float32(0.5)) + Float32(Float32(1.0) / cosTheta))) + Float32(-1.0))))) end
function tmp = code(cosTheta, c) tmp = single(1.0) / (single(1.0) + ((single(pi) ^ single(-0.5)) * (((cosTheta * single(-1.5)) + (((cosTheta ^ single(2.0)) * single(0.5)) + (single(1.0) / cosTheta))) + single(-1.0)))); end
\begin{array}{l}
\\
\frac{1}{1 + {\pi}^{-0.5} \cdot \left(\left(cosTheta \cdot -1.5 + \left({cosTheta}^{2} \cdot 0.5 + \frac{1}{cosTheta}\right)\right) + -1\right)}
\end{array}
Initial program 97.5%
associate-*l*97.6%
*-lft-identity97.6%
*-lft-identity97.6%
associate--l-97.5%
*-commutative97.5%
exp-prod97.5%
Simplified97.5%
Taylor expanded in cosTheta around 0 96.6%
Taylor expanded in c around 0 96.2%
*-un-lft-identity96.2%
sqrt-div96.2%
metadata-eval96.2%
pow1/296.2%
pow-flip96.2%
metadata-eval96.2%
Applied egg-rr96.2%
*-lft-identity96.2%
Simplified96.2%
Final simplification96.2%
(FPCore (cosTheta c) :precision binary32 (/ 1.0 (+ (+ 1.0 c) (* (/ 1.0 (sqrt PI)) (+ (+ (* cosTheta -1.5) (/ 1.0 cosTheta)) -1.0)))))
float code(float cosTheta, float c) {
return 1.0f / ((1.0f + c) + ((1.0f / sqrtf(((float) M_PI))) * (((cosTheta * -1.5f) + (1.0f / cosTheta)) + -1.0f)));
}
function code(cosTheta, c) return Float32(Float32(1.0) / Float32(Float32(Float32(1.0) + c) + Float32(Float32(Float32(1.0) / sqrt(Float32(pi))) * Float32(Float32(Float32(cosTheta * Float32(-1.5)) + Float32(Float32(1.0) / cosTheta)) + Float32(-1.0))))) end
function tmp = code(cosTheta, c) tmp = single(1.0) / ((single(1.0) + c) + ((single(1.0) / sqrt(single(pi))) * (((cosTheta * single(-1.5)) + (single(1.0) / cosTheta)) + single(-1.0)))); end
\begin{array}{l}
\\
\frac{1}{\left(1 + c\right) + \frac{1}{\sqrt{\pi}} \cdot \left(\left(cosTheta \cdot -1.5 + \frac{1}{cosTheta}\right) + -1\right)}
\end{array}
Initial program 97.5%
associate-*l*97.6%
*-lft-identity97.6%
*-lft-identity97.6%
associate--l-97.5%
*-commutative97.5%
exp-prod97.5%
Simplified97.5%
Taylor expanded in cosTheta around 0 95.7%
Final simplification95.7%
(FPCore (cosTheta c) :precision binary32 (/ 1.0 (+ 1.0 (* (+ (+ (* cosTheta -1.5) (/ 1.0 cosTheta)) -1.0) (sqrt (/ 1.0 PI))))))
float code(float cosTheta, float c) {
return 1.0f / (1.0f + ((((cosTheta * -1.5f) + (1.0f / cosTheta)) + -1.0f) * sqrtf((1.0f / ((float) M_PI)))));
}
function code(cosTheta, c) return Float32(Float32(1.0) / Float32(Float32(1.0) + Float32(Float32(Float32(Float32(cosTheta * Float32(-1.5)) + Float32(Float32(1.0) / cosTheta)) + Float32(-1.0)) * sqrt(Float32(Float32(1.0) / Float32(pi)))))) end
function tmp = code(cosTheta, c) tmp = single(1.0) / (single(1.0) + ((((cosTheta * single(-1.5)) + (single(1.0) / cosTheta)) + single(-1.0)) * sqrt((single(1.0) / single(pi))))); end
\begin{array}{l}
\\
\frac{1}{1 + \left(\left(cosTheta \cdot -1.5 + \frac{1}{cosTheta}\right) + -1\right) \cdot \sqrt{\frac{1}{\pi}}}
\end{array}
Initial program 97.5%
associate-*l*97.6%
*-lft-identity97.6%
*-lft-identity97.6%
associate--l-97.5%
*-commutative97.5%
exp-prod97.5%
Simplified97.5%
Taylor expanded in cosTheta around 0 96.6%
Taylor expanded in c around 0 96.2%
Taylor expanded in cosTheta around 0 95.4%
Final simplification95.4%
(FPCore (cosTheta c) :precision binary32 (/ 1.0 (+ (+ 1.0 c) (* (/ 1.0 (sqrt PI)) (+ (/ 1.0 cosTheta) -1.0)))))
float code(float cosTheta, float c) {
return 1.0f / ((1.0f + c) + ((1.0f / sqrtf(((float) M_PI))) * ((1.0f / cosTheta) + -1.0f)));
}
function code(cosTheta, c) return Float32(Float32(1.0) / Float32(Float32(Float32(1.0) + c) + Float32(Float32(Float32(1.0) / sqrt(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) + ((single(1.0) / sqrt(single(pi))) * ((single(1.0) / cosTheta) + single(-1.0)))); end
\begin{array}{l}
\\
\frac{1}{\left(1 + c\right) + \frac{1}{\sqrt{\pi}} \cdot \left(\frac{1}{cosTheta} + -1\right)}
\end{array}
Initial program 97.5%
associate-*l*97.6%
*-lft-identity97.6%
*-lft-identity97.6%
associate--l-97.5%
*-commutative97.5%
exp-prod97.5%
Simplified97.5%
Taylor expanded in cosTheta around 0 94.0%
Final simplification94.0%
(FPCore (cosTheta c) :precision binary32 (/ 1.0 (+ (+ 1.0 c) (/ 1.0 (* (sqrt PI) (* cosTheta (+ 1.0 cosTheta)))))))
float code(float cosTheta, float c) {
return 1.0f / ((1.0f + c) + (1.0f / (sqrtf(((float) M_PI)) * (cosTheta * (1.0f + cosTheta)))));
}
function code(cosTheta, c) return Float32(Float32(1.0) / Float32(Float32(Float32(1.0) + c) + Float32(Float32(1.0) / Float32(sqrt(Float32(pi)) * Float32(cosTheta * Float32(Float32(1.0) + cosTheta)))))) end
function tmp = code(cosTheta, c) tmp = single(1.0) / ((single(1.0) + c) + (single(1.0) / (sqrt(single(pi)) * (cosTheta * (single(1.0) + cosTheta))))); end
\begin{array}{l}
\\
\frac{1}{\left(1 + c\right) + \frac{1}{\sqrt{\pi} \cdot \left(cosTheta \cdot \left(1 + cosTheta\right)\right)}}
\end{array}
Initial program 97.5%
associate-*l*97.6%
*-lft-identity97.6%
*-lft-identity97.6%
associate--l-97.5%
*-commutative97.5%
exp-prod97.5%
Simplified97.5%
Applied egg-rr98.3%
Taylor expanded in cosTheta around 0 94.8%
distribute-rgt-out94.8%
unpow294.8%
distribute-rgt1-in94.8%
Simplified94.8%
Final simplification94.8%
(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 97.5%
associate-*l*97.6%
*-lft-identity97.6%
*-lft-identity97.6%
associate--l-97.5%
*-commutative97.5%
exp-prod97.5%
Simplified97.5%
Applied egg-rr98.3%
expm1-log1p-u90.1%
expm1-udef90.1%
associate-/r/90.1%
pow290.1%
rec-exp90.1%
pow290.1%
Applied egg-rr90.1%
expm1-def90.1%
expm1-log1p98.3%
Simplified98.3%
Taylor expanded in cosTheta around 0 92.2%
Final simplification92.2%
(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 97.5%
associate-+l+97.5%
+-commutative97.5%
fma-def97.6%
Simplified98.6%
Taylor expanded in cosTheta 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 97.5%
distribute-lft-neg-out97.5%
exp-neg97.5%
associate-*r/97.5%
associate-/l*97.5%
/-rgt-identity97.5%
*-commutative97.5%
Simplified98.5%
Taylor expanded in c around 0 97.1%
Taylor expanded in cosTheta around inf 10.7%
Final simplification10.7%
herbie shell --seed 2024010
(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))))))