
(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 9 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(1.0) - Float32(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{1 - \left(cosTheta + cosTheta\right)}}} \cdot e^{cosTheta \cdot \left(-cosTheta\right)}}
\end{array}
Initial program 97.7%
frac-times98.5%
*-un-lft-identity98.5%
clear-num98.5%
associate--l-98.5%
Applied egg-rr98.5%
Final simplification98.5%
(FPCore (cosTheta c)
:precision binary32
(/
1.0
(+
(+ 1.0 c)
(*
(exp (* cosTheta (- cosTheta)))
(/ (sqrt (/ (- 1.0 (+ cosTheta cosTheta)) PI)) cosTheta)))))
float code(float cosTheta, float c) {
return 1.0f / ((1.0f + c) + (expf((cosTheta * -cosTheta)) * (sqrtf(((1.0f - (cosTheta + cosTheta)) / ((float) M_PI))) / cosTheta)));
}
function code(cosTheta, c) return Float32(Float32(1.0) / Float32(Float32(Float32(1.0) + c) + Float32(exp(Float32(cosTheta * Float32(-cosTheta))) * Float32(sqrt(Float32(Float32(Float32(1.0) - Float32(cosTheta + cosTheta)) / Float32(pi))) / cosTheta)))) end
function tmp = code(cosTheta, c) tmp = single(1.0) / ((single(1.0) + c) + (exp((cosTheta * -cosTheta)) * (sqrt(((single(1.0) - (cosTheta + cosTheta)) / single(pi))) / cosTheta))); end
\begin{array}{l}
\\
\frac{1}{\left(1 + c\right) + e^{cosTheta \cdot \left(-cosTheta\right)} \cdot \frac{\sqrt{\frac{1 - \left(cosTheta + cosTheta\right)}{\pi}}}{cosTheta}}
\end{array}
Initial program 97.7%
frac-times98.5%
*-un-lft-identity98.5%
associate-/r*97.9%
associate--l-97.9%
Applied egg-rr97.9%
sqrt-undiv97.9%
Applied egg-rr97.9%
Final simplification97.9%
(FPCore (cosTheta c)
:precision binary32
(/
1.0
(+
1.0
(+
c
(/
(/ (+ (- 1.0 cosTheta) (* (* cosTheta cosTheta) -0.5)) cosTheta)
(* (sqrt PI) (+ 1.0 (* cosTheta cosTheta))))))))
float code(float cosTheta, float c) {
return 1.0f / (1.0f + (c + ((((1.0f - cosTheta) + ((cosTheta * cosTheta) * -0.5f)) / cosTheta) / (sqrtf(((float) M_PI)) * (1.0f + (cosTheta * cosTheta))))));
}
function code(cosTheta, c) return Float32(Float32(1.0) / Float32(Float32(1.0) + Float32(c + Float32(Float32(Float32(Float32(Float32(1.0) - cosTheta) + Float32(Float32(cosTheta * cosTheta) * Float32(-0.5))) / cosTheta) / Float32(sqrt(Float32(pi)) * Float32(Float32(1.0) + 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))) / cosTheta) / (sqrt(single(pi)) * (single(1.0) + (cosTheta * cosTheta)))))); end
\begin{array}{l}
\\
\frac{1}{1 + \left(c + \frac{\frac{\left(1 - cosTheta\right) + \left(cosTheta \cdot cosTheta\right) \cdot -0.5}{cosTheta}}{\sqrt{\pi} \cdot \left(1 + cosTheta \cdot cosTheta\right)}\right)}
\end{array}
Initial program 97.7%
associate-+l+97.7%
associate-*l*97.7%
associate-*l/98.4%
*-lft-identity98.4%
associate-/l*98.4%
/-rgt-identity98.4%
associate-/l*98.4%
Simplified98.4%
Taylor expanded in cosTheta around 0 96.8%
neg-mul-196.8%
associate-+r+96.8%
sub-neg96.8%
*-commutative96.8%
unpow296.8%
Simplified96.8%
Taylor expanded in cosTheta around 0 96.8%
distribute-rgt1-in96.7%
unpow296.7%
Simplified96.7%
Final simplification96.7%
(FPCore (cosTheta c) :precision binary32 (/ 1.0 (+ 1.0 (+ c (/ (+ (+ (* cosTheta -0.5) (/ 1.0 cosTheta)) -1.0) (sqrt PI))))))
float code(float cosTheta, float c) {
return 1.0f / (1.0f + (c + ((((cosTheta * -0.5f) + (1.0f / cosTheta)) + -1.0f) / sqrtf(((float) M_PI)))));
}
function code(cosTheta, c) return Float32(Float32(1.0) / Float32(Float32(1.0) + Float32(c + 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 + ((((cosTheta * single(-0.5)) + (single(1.0) / cosTheta)) + single(-1.0)) / sqrt(single(pi))))); end
\begin{array}{l}
\\
\frac{1}{1 + \left(c + \frac{\left(cosTheta \cdot -0.5 + \frac{1}{cosTheta}\right) + -1}{\sqrt{\pi}}\right)}
\end{array}
Initial program 97.7%
associate-+l+97.7%
associate-*l*97.7%
associate-*l/98.4%
*-lft-identity98.4%
associate-/l*98.4%
/-rgt-identity98.4%
associate-/l*98.4%
Simplified98.4%
Taylor expanded in cosTheta around 0 95.8%
Taylor expanded in cosTheta around 0 95.7%
Final simplification95.7%
(FPCore (cosTheta c) :precision binary32 (/ 1.0 (+ 1.0 (+ c (/ (+ (/ 1.0 cosTheta) -1.0) (sqrt PI))))))
float code(float cosTheta, float c) {
return 1.0f / (1.0f + (c + (((1.0f / cosTheta) + -1.0f) / sqrtf(((float) M_PI)))));
}
function code(cosTheta, c) return Float32(Float32(1.0) / Float32(Float32(1.0) + Float32(c + 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 + (((single(1.0) / cosTheta) + single(-1.0)) / sqrt(single(pi))))); end
\begin{array}{l}
\\
\frac{1}{1 + \left(c + \frac{\frac{1}{cosTheta} + -1}{\sqrt{\pi}}\right)}
\end{array}
Initial program 97.7%
associate-+l+97.7%
associate-*l*97.7%
associate-*l/98.4%
*-lft-identity98.4%
associate-/l*98.4%
/-rgt-identity98.4%
associate-/l*98.4%
Simplified98.4%
Taylor expanded in cosTheta around 0 95.8%
Taylor expanded in cosTheta around 0 95.6%
Final simplification95.6%
(FPCore (cosTheta c) :precision binary32 (/ 1.0 (+ 1.0 (+ c (/ (/ (- 1.0 cosTheta) cosTheta) (sqrt PI))))))
float code(float cosTheta, float c) {
return 1.0f / (1.0f + (c + (((1.0f - cosTheta) / cosTheta) / sqrtf(((float) M_PI)))));
}
function code(cosTheta, c) return Float32(Float32(1.0) / Float32(Float32(1.0) + Float32(c + Float32(Float32(Float32(Float32(1.0) - cosTheta) / cosTheta) / sqrt(Float32(pi)))))) end
function tmp = code(cosTheta, c) tmp = single(1.0) / (single(1.0) + (c + (((single(1.0) - cosTheta) / cosTheta) / sqrt(single(pi))))); end
\begin{array}{l}
\\
\frac{1}{1 + \left(c + \frac{\frac{1 - cosTheta}{cosTheta}}{\sqrt{\pi}}\right)}
\end{array}
Initial program 97.7%
associate-+l+97.7%
associate-*l*97.7%
associate-*l/98.4%
*-lft-identity98.4%
associate-/l*98.4%
/-rgt-identity98.4%
associate-/l*98.4%
Simplified98.4%
Taylor expanded in cosTheta around 0 95.8%
Taylor expanded in cosTheta around 0 95.6%
neg-mul-195.6%
sub-neg95.6%
Simplified95.6%
Final simplification95.6%
(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 97.7%
frac-times98.5%
*-un-lft-identity98.5%
clear-num98.5%
associate--l-98.5%
Applied egg-rr98.5%
Taylor expanded in cosTheta around 0 93.8%
Final simplification93.8%
(FPCore (cosTheta c) :precision binary32 (* c (* (* cosTheta cosTheta) (- PI))))
float code(float cosTheta, float c) {
return c * ((cosTheta * cosTheta) * -((float) M_PI));
}
function code(cosTheta, c) return Float32(c * Float32(Float32(cosTheta * cosTheta) * Float32(-Float32(pi)))) end
function tmp = code(cosTheta, c) tmp = c * ((cosTheta * cosTheta) * -single(pi)); end
\begin{array}{l}
\\
c \cdot \left(\left(cosTheta \cdot cosTheta\right) \cdot \left(-\pi\right)\right)
\end{array}
Initial program 97.7%
associate-+l+97.7%
associate-*l*97.7%
associate-*l/98.4%
*-lft-identity98.4%
associate-/r/98.4%
associate-/l/98.4%
Simplified98.5%
Taylor expanded in cosTheta around 0 95.8%
fma-def95.8%
associate-*r*95.8%
mul-1-neg95.8%
unpow295.8%
*-commutative95.8%
mul-1-neg95.8%
Simplified95.8%
Taylor expanded in c around inf 11.2%
mul-1-neg11.2%
*-commutative11.2%
distribute-rgt-neg-in11.2%
*-commutative11.2%
unpow211.2%
Simplified11.2%
Final simplification11.2%
(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 97.7%
associate-+l+97.7%
associate-*l*97.7%
associate-*l/98.4%
*-lft-identity98.4%
associate-/r/98.4%
associate-/l/98.4%
Simplified98.5%
Taylor expanded in cosTheta around inf 10.3%
Taylor expanded in c around 0 10.3%
neg-mul-110.3%
+-commutative10.3%
unsub-neg10.3%
Simplified10.3%
Final simplification10.3%
herbie shell --seed 2023274
(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))))))