
(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 14 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 (fma (/ (/ (sqrt (+ 1.0 (* cosTheta -2.0))) cosTheta) (sqrt PI)) (pow (exp cosTheta) (- cosTheta)) (+ 1.0 c))))
float code(float cosTheta, float c) {
return 1.0f / fmaf(((sqrtf((1.0f + (cosTheta * -2.0f))) / cosTheta) / sqrtf(((float) M_PI))), powf(expf(cosTheta), -cosTheta), (1.0f + c));
}
function code(cosTheta, c) return Float32(Float32(1.0) / fma(Float32(Float32(sqrt(Float32(Float32(1.0) + Float32(cosTheta * Float32(-2.0)))) / cosTheta) / sqrt(Float32(pi))), (exp(cosTheta) ^ Float32(-cosTheta)), Float32(Float32(1.0) + c))) end
\begin{array}{l}
\\
\frac{1}{\mathsf{fma}\left(\frac{\frac{\sqrt{1 + cosTheta \cdot -2}}{cosTheta}}{\sqrt{\pi}}, {\left(e^{cosTheta}\right)}^{\left(-cosTheta\right)}, 1 + c\right)}
\end{array}
Initial program 97.4%
+-commutative97.4%
fma-define97.4%
Simplified98.0%
Final simplification98.0%
(FPCore (cosTheta c)
:precision binary32
(/
1.0
(+
(+ 1.0 c)
(*
(/ (/ (sqrt (- 1.0 (+ cosTheta cosTheta))) cosTheta) (sqrt PI))
(exp (- (* cosTheta cosTheta)))))))
float code(float cosTheta, float c) {
return 1.0f / ((1.0f + c) + (((sqrtf((1.0f - (cosTheta + cosTheta))) / 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(Float32(sqrt(Float32(Float32(1.0) - Float32(cosTheta + cosTheta))) / cosTheta) / sqrt(Float32(pi))) * exp(Float32(-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))) * exp(-(cosTheta * cosTheta)))); end
\begin{array}{l}
\\
\frac{1}{\left(1 + c\right) + \frac{\frac{\sqrt{1 - \left(cosTheta + cosTheta\right)}}{cosTheta}}{\sqrt{\pi}} \cdot e^{-cosTheta \cdot cosTheta}}
\end{array}
Initial program 97.4%
associate-*l/98.1%
*-un-lft-identity98.1%
associate--l-98.0%
Applied egg-rr98.0%
Final simplification98.0%
(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 97.4%
associate-+l+97.4%
+-commutative97.4%
*-commutative97.4%
associate-*l*97.4%
fma-define97.4%
Simplified97.3%
Taylor expanded in c around 0 97.5%
Final simplification97.5%
(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 97.4%
associate-+l+97.4%
+-commutative97.4%
*-commutative97.4%
associate-*l*97.4%
fma-define97.4%
Simplified97.3%
Taylor expanded in c around 0 96.9%
Final simplification96.9%
(FPCore (cosTheta c)
:precision binary32
(/
1.0
(+
(+ 1.0 c)
(*
(exp (- (* cosTheta cosTheta)))
(/ (+ (+ (* cosTheta -0.5) (/ 1.0 cosTheta)) -1.0) (sqrt PI))))))
float code(float cosTheta, float c) {
return 1.0f / ((1.0f + c) + (expf(-(cosTheta * cosTheta)) * ((((cosTheta * -0.5f) + (1.0f / cosTheta)) + -1.0f) / sqrtf(((float) M_PI)))));
}
function code(cosTheta, c) return Float32(Float32(1.0) / Float32(Float32(Float32(1.0) + c) + Float32(exp(Float32(-Float32(cosTheta * cosTheta))) * Float32(Float32(Float32(Float32(cosTheta * Float32(-0.5)) + Float32(Float32(1.0) / cosTheta)) + Float32(-1.0)) / sqrt(Float32(pi)))))) end
function tmp = code(cosTheta, c) tmp = single(1.0) / ((single(1.0) + c) + (exp(-(cosTheta * cosTheta)) * ((((cosTheta * single(-0.5)) + (single(1.0) / cosTheta)) + single(-1.0)) / sqrt(single(pi))))); end
\begin{array}{l}
\\
\frac{1}{\left(1 + c\right) + e^{-cosTheta \cdot cosTheta} \cdot \frac{\left(cosTheta \cdot -0.5 + \frac{1}{cosTheta}\right) + -1}{\sqrt{\pi}}}
\end{array}
Initial program 97.4%
associate-*l/98.1%
*-un-lft-identity98.1%
associate--l-98.0%
Applied egg-rr98.0%
Taylor expanded in cosTheta around 0 96.3%
Final simplification96.3%
(FPCore (cosTheta c)
:precision binary32
(/
1.0
(+
(+ 1.0 c)
(*
(exp (- (* cosTheta cosTheta)))
(/ (+ (/ 1.0 cosTheta) -1.0) (sqrt PI))))))
float code(float cosTheta, float c) {
return 1.0f / ((1.0f + c) + (expf(-(cosTheta * cosTheta)) * (((1.0f / cosTheta) + -1.0f) / sqrtf(((float) M_PI)))));
}
function code(cosTheta, c) return Float32(Float32(1.0) / Float32(Float32(Float32(1.0) + c) + Float32(exp(Float32(-Float32(cosTheta * cosTheta))) * Float32(Float32(Float32(Float32(1.0) / cosTheta) + Float32(-1.0)) / sqrt(Float32(pi)))))) end
function tmp = code(cosTheta, c) tmp = single(1.0) / ((single(1.0) + c) + (exp(-(cosTheta * cosTheta)) * (((single(1.0) / cosTheta) + single(-1.0)) / sqrt(single(pi))))); end
\begin{array}{l}
\\
\frac{1}{\left(1 + c\right) + e^{-cosTheta \cdot cosTheta} \cdot \frac{\frac{1}{cosTheta} + -1}{\sqrt{\pi}}}
\end{array}
Initial program 97.4%
associate-*l/98.1%
*-un-lft-identity98.1%
associate--l-98.0%
Applied egg-rr98.0%
Taylor expanded in cosTheta around 0 95.7%
Final simplification95.7%
(FPCore (cosTheta c) :precision binary32 (/ 1.0 (+ 1.0 (- (/ (/ 1.0 cosTheta) (sqrt PI)) (sqrt (/ 1.0 PI))))))
float code(float cosTheta, float c) {
return 1.0f / (1.0f + (((1.0f / cosTheta) / sqrtf(((float) M_PI))) - sqrtf((1.0f / ((float) M_PI)))));
}
function code(cosTheta, c) return Float32(Float32(1.0) / Float32(Float32(1.0) + Float32(Float32(Float32(Float32(1.0) / cosTheta) / sqrt(Float32(pi))) - sqrt(Float32(Float32(1.0) / Float32(pi)))))) end
function tmp = code(cosTheta, c) tmp = single(1.0) / (single(1.0) + (((single(1.0) / cosTheta) / sqrt(single(pi))) - sqrt((single(1.0) / single(pi))))); end
\begin{array}{l}
\\
\frac{1}{1 + \left(\frac{\frac{1}{cosTheta}}{\sqrt{\pi}} - \sqrt{\frac{1}{\pi}}\right)}
\end{array}
Initial program 97.4%
+-commutative97.4%
fma-define97.4%
Simplified98.0%
Taylor expanded in c around 0 96.9%
+-commutative96.9%
fma-define97.1%
neg-mul-197.1%
+-commutative97.1%
*-commutative97.1%
fma-undefine97.1%
Simplified97.1%
Taylor expanded in cosTheta around 0 94.6%
inv-pow94.6%
sqrt-div94.6%
metadata-eval94.6%
inv-pow94.6%
unpow-prod-down95.2%
inv-pow95.2%
associate-/r*95.3%
Applied egg-rr95.3%
Final simplification95.3%
(FPCore (cosTheta c) :precision binary32 (/ 1.0 (+ 1.0 (- (/ 1.0 (* cosTheta (sqrt PI))) (pow PI -0.5)))))
float code(float cosTheta, float c) {
return 1.0f / (1.0f + ((1.0f / (cosTheta * sqrtf(((float) M_PI)))) - powf(((float) M_PI), -0.5f)));
}
function code(cosTheta, c) return Float32(Float32(1.0) / Float32(Float32(1.0) + Float32(Float32(Float32(1.0) / Float32(cosTheta * sqrt(Float32(pi)))) - (Float32(pi) ^ Float32(-0.5))))) end
function tmp = code(cosTheta, c) tmp = single(1.0) / (single(1.0) + ((single(1.0) / (cosTheta * sqrt(single(pi)))) - (single(pi) ^ single(-0.5)))); end
\begin{array}{l}
\\
\frac{1}{1 + \left(\frac{1}{cosTheta \cdot \sqrt{\pi}} - {\pi}^{-0.5}\right)}
\end{array}
Initial program 97.4%
+-commutative97.4%
fma-define97.4%
Simplified98.0%
Taylor expanded in c around 0 96.9%
+-commutative96.9%
fma-define97.1%
neg-mul-197.1%
+-commutative97.1%
*-commutative97.1%
fma-undefine97.1%
Simplified97.1%
Taylor expanded in cosTheta around 0 94.6%
+-commutative94.6%
add-sqr-sqrt94.4%
fma-define94.4%
Applied egg-rr94.8%
fma-neg94.7%
pow-sqr95.2%
metadata-eval95.2%
unpow-195.2%
Simplified95.2%
Final simplification95.2%
(FPCore (cosTheta c) :precision binary32 (/ 1.0 (fma (pow PI -0.5) (+ (/ 1.0 cosTheta) -1.0) 1.0)))
float code(float cosTheta, float c) {
return 1.0f / fmaf(powf(((float) M_PI), -0.5f), ((1.0f / cosTheta) + -1.0f), 1.0f);
}
function code(cosTheta, c) return Float32(Float32(1.0) / fma((Float32(pi) ^ Float32(-0.5)), Float32(Float32(Float32(1.0) / cosTheta) + Float32(-1.0)), Float32(1.0))) end
\begin{array}{l}
\\
\frac{1}{\mathsf{fma}\left({\pi}^{-0.5}, \frac{1}{cosTheta} + -1, 1\right)}
\end{array}
Initial program 97.4%
+-commutative97.4%
fma-define97.4%
Simplified98.0%
Taylor expanded in c around 0 96.9%
+-commutative96.9%
fma-define97.1%
neg-mul-197.1%
+-commutative97.1%
*-commutative97.1%
fma-undefine97.1%
Simplified97.1%
Taylor expanded in cosTheta around 0 94.6%
*-un-lft-identity94.6%
+-commutative94.6%
distribute-rgt-out94.7%
fma-define94.8%
inv-pow94.8%
sqrt-pow194.8%
metadata-eval94.8%
Applied egg-rr94.8%
*-lft-identity94.8%
Simplified94.8%
Final simplification94.8%
(FPCore (cosTheta c) :precision binary32 (/ 1.0 (+ 1.0 (+ c (* (pow PI -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) * ((1.0f / cosTheta) + -1.0f))));
}
function code(cosTheta, c) return Float32(Float32(1.0) / Float32(Float32(1.0) + Float32(c + Float32((Float32(pi) ^ Float32(-0.5)) * Float32(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)) * ((single(1.0) / cosTheta) + single(-1.0))))); end
\begin{array}{l}
\\
\frac{1}{1 + \left(c + {\pi}^{-0.5} \cdot \left(\frac{1}{cosTheta} + -1\right)\right)}
\end{array}
Initial program 97.4%
associate-+l+97.4%
+-commutative97.4%
*-commutative97.4%
associate-*l*97.4%
fma-define97.4%
Simplified97.3%
Taylor expanded in cosTheta around 0 94.8%
+-commutative94.8%
distribute-rgt-out94.7%
fma-define94.8%
Simplified94.8%
fma-undefine94.7%
inv-pow94.7%
sqrt-pow194.7%
metadata-eval94.7%
*-commutative94.7%
Applied egg-rr94.7%
Final simplification94.7%
(FPCore (cosTheta c) :precision binary32 (/ 1.0 (+ 1.0 (* (pow PI -0.5) (+ (/ 1.0 cosTheta) -1.0)))))
float code(float cosTheta, float c) {
return 1.0f / (1.0f + (powf(((float) M_PI), -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(1.0) / cosTheta) + Float32(-1.0))))) end
function tmp = code(cosTheta, c) tmp = single(1.0) / (single(1.0) + ((single(pi) ^ single(-0.5)) * ((single(1.0) / cosTheta) + single(-1.0)))); end
\begin{array}{l}
\\
\frac{1}{1 + {\pi}^{-0.5} \cdot \left(\frac{1}{cosTheta} + -1\right)}
\end{array}
Initial program 97.4%
+-commutative97.4%
fma-define97.4%
Simplified98.0%
Taylor expanded in c around 0 96.9%
+-commutative96.9%
fma-define97.1%
neg-mul-197.1%
+-commutative97.1%
*-commutative97.1%
fma-undefine97.1%
Simplified97.1%
Taylor expanded in cosTheta around 0 94.6%
*-un-lft-identity94.6%
distribute-rgt-out94.7%
inv-pow94.7%
sqrt-pow194.7%
metadata-eval94.7%
Applied egg-rr94.7%
*-lft-identity94.7%
Simplified94.7%
Final simplification94.7%
(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 97.4%
+-commutative97.4%
fma-define97.4%
Simplified98.0%
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 97.4%
associate-+l+97.4%
+-commutative97.4%
*-commutative97.4%
associate-*l*97.4%
fma-define97.4%
Simplified97.3%
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 97.4%
associate-+l+97.4%
+-commutative97.4%
*-commutative97.4%
associate-*l*97.4%
fma-define97.4%
Simplified97.3%
Taylor expanded in c around inf 10.7%
Taylor expanded in c around 0 10.7%
Final simplification10.7%
herbie shell --seed 2024053
(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))))))