
(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
(+
c
(/
(sqrt (fma cosTheta -2.0 1.0))
(* (sqrt PI) (* cosTheta (exp (* cosTheta cosTheta)))))))))
float code(float cosTheta, float c) {
return 1.0f / (1.0f + (c + (sqrtf(fmaf(cosTheta, -2.0f, 1.0f)) / (sqrtf(((float) M_PI)) * (cosTheta * expf((cosTheta * cosTheta)))))));
}
function code(cosTheta, c) return Float32(Float32(1.0) / Float32(Float32(1.0) + Float32(c + Float32(sqrt(fma(cosTheta, Float32(-2.0), Float32(1.0))) / Float32(sqrt(Float32(pi)) * Float32(cosTheta * exp(Float32(cosTheta * cosTheta)))))))) end
\begin{array}{l}
\\
\frac{1}{1 + \left(c + \frac{\sqrt{\mathsf{fma}\left(cosTheta, -2, 1\right)}}{\sqrt{\pi} \cdot \left(cosTheta \cdot e^{cosTheta \cdot cosTheta}\right)}\right)}
\end{array}
Initial program 97.9%
associate-+l+97.9%
associate-*l*97.9%
associate-*l/98.4%
*-lft-identity98.4%
associate-/r/98.4%
associate-/l/98.5%
Simplified98.5%
Final simplification98.5%
(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(Float32(1.0) - cosTheta) - cosTheta)) / cosTheta) / sqrt(Float32(pi))) * exp(Float32(cosTheta * Float32(-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{\left(1 - cosTheta\right) - cosTheta}}{cosTheta}}{\sqrt{\pi}} \cdot e^{cosTheta \cdot \left(-cosTheta\right)}}
\end{array}
Initial program 97.9%
associate-*l/98.5%
*-un-lft-identity98.5%
Applied egg-rr98.5%
Final simplification98.5%
(FPCore (cosTheta c)
:precision binary32
(/
1.0
(+
1.0
(/
(sqrt (/ (fma cosTheta -2.0 1.0) PI))
(* cosTheta (exp (* cosTheta cosTheta)))))))
float code(float cosTheta, float c) {
return 1.0f / (1.0f + (sqrtf((fmaf(cosTheta, -2.0f, 1.0f) / ((float) M_PI))) / (cosTheta * expf((cosTheta * cosTheta)))));
}
function code(cosTheta, c) return Float32(Float32(1.0) / Float32(Float32(1.0) + Float32(sqrt(Float32(fma(cosTheta, Float32(-2.0), Float32(1.0)) / Float32(pi))) / Float32(cosTheta * exp(Float32(cosTheta * cosTheta)))))) end
\begin{array}{l}
\\
\frac{1}{1 + \frac{\sqrt{\frac{\mathsf{fma}\left(cosTheta, -2, 1\right)}{\pi}}}{cosTheta \cdot e^{cosTheta \cdot cosTheta}}}
\end{array}
Initial program 97.9%
associate-+l+97.9%
associate-*l*97.9%
associate-*l/98.4%
*-lft-identity98.4%
associate-/l*98.4%
/-rgt-identity98.4%
associate-/l*98.4%
Simplified98.4%
*-un-lft-identity98.4%
associate-/r*98.4%
fma-udef98.4%
+-commutative98.4%
associate-/l/98.5%
+-commutative98.5%
fma-udef98.5%
Applied egg-rr98.5%
Taylor expanded in c around 0 97.8%
associate-*l/97.9%
+-commutative97.9%
*-commutative97.9%
fma-udef97.9%
*-lft-identity97.9%
unpow297.9%
Simplified97.9%
Final simplification97.9%
(FPCore (cosTheta c)
:precision binary32
(/
1.0
(+
1.0
(+
c
(/
(+ (- 1.0 cosTheta) (* (* cosTheta cosTheta) -0.5))
(* (sqrt PI) (* cosTheta (exp (* cosTheta cosTheta)))))))))
float code(float cosTheta, float c) {
return 1.0f / (1.0f + (c + (((1.0f - cosTheta) + ((cosTheta * cosTheta) * -0.5f)) / (sqrtf(((float) M_PI)) * (cosTheta * expf((cosTheta * cosTheta)))))));
}
function code(cosTheta, c) return Float32(Float32(1.0) / Float32(Float32(1.0) + Float32(c + Float32(Float32(Float32(Float32(1.0) - cosTheta) + Float32(Float32(cosTheta * cosTheta) * Float32(-0.5))) / Float32(sqrt(Float32(pi)) * Float32(cosTheta * exp(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))) / (sqrt(single(pi)) * (cosTheta * exp((cosTheta * cosTheta))))))); end
\begin{array}{l}
\\
\frac{1}{1 + \left(c + \frac{\left(1 - cosTheta\right) + \left(cosTheta \cdot cosTheta\right) \cdot -0.5}{\sqrt{\pi} \cdot \left(cosTheta \cdot e^{cosTheta \cdot cosTheta}\right)}\right)}
\end{array}
Initial program 97.9%
associate-+l+97.9%
associate-*l*97.9%
associate-*l/98.4%
*-lft-identity98.4%
associate-/r/98.4%
associate-/l/98.5%
Simplified98.5%
Taylor expanded in cosTheta around 0 96.3%
neg-mul-196.3%
associate-+r+96.2%
sub-neg96.2%
*-commutative96.2%
unpow296.2%
Simplified96.3%
Final simplification96.3%
(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 97.9%
associate-+l+97.9%
associate-*l*97.9%
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 96.3%
neg-mul-196.3%
associate-+r+96.2%
sub-neg96.2%
*-commutative96.2%
unpow296.2%
Simplified96.2%
Taylor expanded in cosTheta around 0 96.2%
distribute-rgt1-in96.2%
unpow296.2%
Simplified96.2%
Final simplification96.2%
(FPCore (cosTheta c) :precision binary32 (/ 1.0 (+ 1.0 (* (sqrt (/ 1.0 PI)) (+ (+ (* cosTheta -1.5) (/ 1.0 cosTheta)) -1.0)))))
float code(float cosTheta, float c) {
return 1.0f / (1.0f + (sqrtf((1.0f / ((float) M_PI))) * (((cosTheta * -1.5f) + (1.0f / cosTheta)) + -1.0f)));
}
function code(cosTheta, c) return Float32(Float32(1.0) / Float32(Float32(1.0) + Float32(sqrt(Float32(Float32(1.0) / 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) + (sqrt((single(1.0) / single(pi))) * (((cosTheta * single(-1.5)) + (single(1.0) / cosTheta)) + single(-1.0)))); end
\begin{array}{l}
\\
\frac{1}{1 + \sqrt{\frac{1}{\pi}} \cdot \left(\left(cosTheta \cdot -1.5 + \frac{1}{cosTheta}\right) + -1\right)}
\end{array}
Initial program 97.9%
associate-+l+97.9%
associate-*l*97.9%
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 96.3%
neg-mul-196.3%
associate-+r+96.2%
sub-neg96.2%
*-commutative96.2%
unpow296.2%
Simplified96.2%
Taylor expanded in c around 0 95.6%
*-commutative95.6%
associate--l+95.6%
*-commutative95.6%
unpow295.6%
associate-*r*95.6%
unpow295.6%
Simplified95.6%
Taylor expanded in cosTheta around 0 95.7%
Final simplification95.7%
(FPCore (cosTheta c) :precision binary32 (/ 1.0 (+ 1.0 (* (sqrt (/ 1.0 PI)) (+ (/ 1.0 cosTheta) -1.0)))))
float code(float cosTheta, float c) {
return 1.0f / (1.0f + (sqrtf((1.0f / ((float) M_PI))) * ((1.0f / cosTheta) + -1.0f)));
}
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(-1.0))))) 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)))); end
\begin{array}{l}
\\
\frac{1}{1 + \sqrt{\frac{1}{\pi}} \cdot \left(\frac{1}{cosTheta} + -1\right)}
\end{array}
Initial program 97.9%
associate-+l+97.9%
associate-*l*97.9%
associate-*l/98.4%
*-lft-identity98.4%
associate-/r/98.4%
associate-/l/98.5%
Simplified98.5%
Taylor expanded in cosTheta around 0 94.4%
distribute-rgt-out94.4%
Simplified94.4%
Taylor expanded in c around 0 94.3%
Final simplification94.3%
(FPCore (cosTheta c) :precision binary32 (/ 1.0 (+ c (+ 1.0 (/ (+ (/ 1.0 cosTheta) -1.0) (sqrt PI))))))
float code(float cosTheta, float c) {
return 1.0f / (c + (1.0f + (((1.0f / cosTheta) + -1.0f) / sqrtf(((float) M_PI)))));
}
function code(cosTheta, c) return Float32(Float32(1.0) / Float32(c + Float32(Float32(1.0) + Float32(Float32(Float32(Float32(1.0) / cosTheta) + Float32(-1.0)) / sqrt(Float32(pi)))))) end
function tmp = code(cosTheta, c) tmp = single(1.0) / (c + (single(1.0) + (((single(1.0) / cosTheta) + single(-1.0)) / sqrt(single(pi))))); end
\begin{array}{l}
\\
\frac{1}{c + \left(1 + \frac{\frac{1}{cosTheta} + -1}{\sqrt{\pi}}\right)}
\end{array}
Initial program 97.9%
associate-+l+97.9%
associate-*l*97.9%
associate-*l/98.4%
*-lft-identity98.4%
associate-/r/98.4%
associate-/l/98.5%
Simplified98.5%
Taylor expanded in cosTheta around 0 94.4%
distribute-rgt-out94.4%
Simplified94.4%
*-un-lft-identity94.4%
+-commutative94.4%
sqrt-div94.4%
metadata-eval94.4%
Applied egg-rr94.4%
*-lft-identity94.4%
associate-+r+94.4%
+-commutative94.4%
associate-*l/94.8%
*-lft-identity94.8%
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 97.9%
associate-*l/98.5%
*-un-lft-identity98.5%
Applied egg-rr98.5%
Taylor expanded in cosTheta around 0 92.8%
Final simplification92.8%
(FPCore (cosTheta c) :precision binary32 (* PI (* c (* cosTheta (- cosTheta)))))
float code(float cosTheta, float c) {
return ((float) M_PI) * (c * (cosTheta * -cosTheta));
}
function code(cosTheta, c) return Float32(Float32(pi) * Float32(c * Float32(cosTheta * Float32(-cosTheta)))) end
function tmp = code(cosTheta, c) tmp = single(pi) * (c * (cosTheta * -cosTheta)); end
\begin{array}{l}
\\
\pi \cdot \left(c \cdot \left(cosTheta \cdot \left(-cosTheta\right)\right)\right)
\end{array}
Initial program 97.9%
associate-+l+97.9%
associate-*l*97.9%
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 92.1%
Taylor expanded in cosTheta around 0 92.4%
+-commutative92.4%
mul-1-neg92.4%
unsub-neg92.4%
unpow292.4%
associate-*l*92.4%
Simplified92.4%
Taylor expanded in c around inf 10.8%
mul-1-neg10.8%
associate-*r*10.8%
distribute-rgt-neg-in10.8%
unpow210.8%
Simplified10.8%
Final simplification10.8%
(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%
associate-*l*97.9%
associate-*l/98.4%
*-lft-identity98.4%
associate-/r/98.4%
associate-/l/98.5%
Simplified98.5%
Taylor expanded in cosTheta around inf 10.8%
Taylor expanded in c around 0 10.8%
mul-1-neg10.8%
unsub-neg10.8%
Simplified10.8%
Final simplification10.8%
(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%
associate-*l*97.9%
associate-*l/98.4%
*-lft-identity98.4%
associate-/r/98.4%
associate-/l/98.5%
Simplified98.5%
Taylor expanded in c around 0 97.8%
Taylor expanded in cosTheta around inf 10.8%
Final simplification10.8%
herbie shell --seed 2023297
(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))))))