
(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 10 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 (- (- 1.0 cosTheta) cosTheta)) (exp (* cosTheta (- cosTheta))))
cosTheta)
(sqrt PI)))))
float code(float cosTheta, float c) {
return 1.0f / ((1.0f + c) + (((sqrtf(((1.0f - cosTheta) - cosTheta)) * expf((cosTheta * -cosTheta))) / cosTheta) / sqrtf(((float) M_PI))));
}
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)) * exp(Float32(cosTheta * Float32(-cosTheta)))) / cosTheta) / sqrt(Float32(pi))))) end
function tmp = code(cosTheta, c) tmp = single(1.0) / ((single(1.0) + c) + (((sqrt(((single(1.0) - cosTheta) - cosTheta)) * exp((cosTheta * -cosTheta))) / cosTheta) / sqrt(single(pi)))); end
\begin{array}{l}
\\
\frac{1}{\left(1 + c\right) + \frac{\frac{\sqrt{\left(1 - cosTheta\right) - cosTheta} \cdot e^{cosTheta \cdot \left(-cosTheta\right)}}{cosTheta}}{\sqrt{\pi}}}
\end{array}
Initial program 97.7%
*-commutativeN/A
div-invN/A
associate-*l/N/A
/-lowering-/.f32N/A
associate-*l/N/A
/-lowering-/.f32N/A
*-lowering-*.f32N/A
sqrt-lowering-sqrt.f32N/A
--lowering--.f32N/A
--lowering--.f32N/A
exp-lowering-exp.f32N/A
*-commutativeN/A
*-lowering-*.f32N/A
neg-lowering-neg.f32N/A
sqrt-lowering-sqrt.f32N/A
Applied egg-rr98.2%
(FPCore (cosTheta c)
:precision binary32
(let* ((t_0 (fma c (+ c -1.0) 1.0)))
(/
1.0
(/
(fma
(fma c (* c c) 1.0)
cosTheta
(*
t_0
(*
(sqrt (/ (- (- 1.0 cosTheta) cosTheta) PI))
(fma
(* cosTheta cosTheta)
(fma
(* cosTheta cosTheta)
(fma (* cosTheta cosTheta) -0.16666666666666666 0.5)
-1.0)
1.0))))
(* cosTheta t_0)))))
float code(float cosTheta, float c) {
float t_0 = fmaf(c, (c + -1.0f), 1.0f);
return 1.0f / (fmaf(fmaf(c, (c * c), 1.0f), cosTheta, (t_0 * (sqrtf((((1.0f - cosTheta) - cosTheta) / ((float) M_PI))) * fmaf((cosTheta * cosTheta), fmaf((cosTheta * cosTheta), fmaf((cosTheta * cosTheta), -0.16666666666666666f, 0.5f), -1.0f), 1.0f)))) / (cosTheta * t_0));
}
function code(cosTheta, c) t_0 = fma(c, Float32(c + Float32(-1.0)), Float32(1.0)) return Float32(Float32(1.0) / Float32(fma(fma(c, Float32(c * c), Float32(1.0)), cosTheta, Float32(t_0 * Float32(sqrt(Float32(Float32(Float32(Float32(1.0) - cosTheta) - cosTheta) / Float32(pi))) * fma(Float32(cosTheta * cosTheta), fma(Float32(cosTheta * cosTheta), fma(Float32(cosTheta * cosTheta), Float32(-0.16666666666666666), Float32(0.5)), Float32(-1.0)), Float32(1.0))))) / Float32(cosTheta * t_0))) end
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \mathsf{fma}\left(c, c + -1, 1\right)\\
\frac{1}{\frac{\mathsf{fma}\left(\mathsf{fma}\left(c, c \cdot c, 1\right), cosTheta, t\_0 \cdot \left(\sqrt{\frac{\left(1 - cosTheta\right) - cosTheta}{\pi}} \cdot \mathsf{fma}\left(cosTheta \cdot cosTheta, \mathsf{fma}\left(cosTheta \cdot cosTheta, \mathsf{fma}\left(cosTheta \cdot cosTheta, -0.16666666666666666, 0.5\right), -1\right), 1\right)\right)\right)}{cosTheta \cdot t\_0}}
\end{array}
\end{array}
Initial program 97.7%
Applied egg-rr98.1%
Taylor expanded in cosTheta around 0
+-commutativeN/A
accelerator-lowering-fma.f32N/A
unpow2N/A
*-lowering-*.f32N/A
sub-negN/A
metadata-evalN/A
accelerator-lowering-fma.f32N/A
unpow2N/A
*-lowering-*.f32N/A
+-commutativeN/A
*-commutativeN/A
accelerator-lowering-fma.f32N/A
unpow2N/A
*-lowering-*.f3297.8
Simplified97.8%
Final simplification97.8%
(FPCore (cosTheta c)
:precision binary32
(/
(fma cosTheta (fma c c (- c)) cosTheta)
(fma
1.0
cosTheta
(*
(sqrt (/ (- 1.0 (+ cosTheta cosTheta)) PI))
(*
(fma c (+ c -1.0) 1.0)
(fma
(* cosTheta cosTheta)
(fma
cosTheta
(* cosTheta (fma (* cosTheta cosTheta) -0.16666666666666666 0.5))
-1.0)
1.0))))))
float code(float cosTheta, float c) {
return fmaf(cosTheta, fmaf(c, c, -c), cosTheta) / fmaf(1.0f, cosTheta, (sqrtf(((1.0f - (cosTheta + cosTheta)) / ((float) M_PI))) * (fmaf(c, (c + -1.0f), 1.0f) * fmaf((cosTheta * cosTheta), fmaf(cosTheta, (cosTheta * fmaf((cosTheta * cosTheta), -0.16666666666666666f, 0.5f)), -1.0f), 1.0f))));
}
function code(cosTheta, c) return Float32(fma(cosTheta, fma(c, c, Float32(-c)), cosTheta) / fma(Float32(1.0), cosTheta, Float32(sqrt(Float32(Float32(Float32(1.0) - Float32(cosTheta + cosTheta)) / Float32(pi))) * Float32(fma(c, Float32(c + Float32(-1.0)), Float32(1.0)) * fma(Float32(cosTheta * cosTheta), fma(cosTheta, Float32(cosTheta * fma(Float32(cosTheta * cosTheta), Float32(-0.16666666666666666), Float32(0.5))), Float32(-1.0)), Float32(1.0)))))) end
\begin{array}{l}
\\
\frac{\mathsf{fma}\left(cosTheta, \mathsf{fma}\left(c, c, -c\right), cosTheta\right)}{\mathsf{fma}\left(1, cosTheta, \sqrt{\frac{1 - \left(cosTheta + cosTheta\right)}{\pi}} \cdot \left(\mathsf{fma}\left(c, c + -1, 1\right) \cdot \mathsf{fma}\left(cosTheta \cdot cosTheta, \mathsf{fma}\left(cosTheta, cosTheta \cdot \mathsf{fma}\left(cosTheta \cdot cosTheta, -0.16666666666666666, 0.5\right), -1\right), 1\right)\right)\right)}
\end{array}
Initial program 97.7%
Applied egg-rr98.1%
Taylor expanded in cosTheta around 0
+-commutativeN/A
accelerator-lowering-fma.f32N/A
unpow2N/A
*-lowering-*.f32N/A
sub-negN/A
metadata-evalN/A
accelerator-lowering-fma.f32N/A
unpow2N/A
*-lowering-*.f32N/A
+-commutativeN/A
*-commutativeN/A
accelerator-lowering-fma.f32N/A
unpow2N/A
*-lowering-*.f3297.8
Simplified97.8%
clear-numN/A
/-lowering-/.f32N/A
*-commutativeN/A
distribute-lft-inN/A
*-commutativeN/A
*-lft-identityN/A
accelerator-lowering-fma.f32N/A
distribute-lft-inN/A
accelerator-lowering-fma.f32N/A
*-commutativeN/A
mul-1-negN/A
neg-lowering-neg.f32N/A
Applied egg-rr97.8%
Taylor expanded in c around 0
Simplified97.8%
Final simplification97.8%
(FPCore (cosTheta c)
:precision binary32
(/
1.0
(+
(+ 1.0 c)
(/
(/
(*
(sqrt (- (- 1.0 cosTheta) cosTheta))
(fma (* cosTheta cosTheta) (fma (* cosTheta cosTheta) 0.5 -1.0) 1.0))
cosTheta)
(sqrt PI)))))
float code(float cosTheta, float c) {
return 1.0f / ((1.0f + c) + (((sqrtf(((1.0f - cosTheta) - cosTheta)) * fmaf((cosTheta * cosTheta), fmaf((cosTheta * cosTheta), 0.5f, -1.0f), 1.0f)) / cosTheta) / sqrtf(((float) M_PI))));
}
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)) * fma(Float32(cosTheta * cosTheta), fma(Float32(cosTheta * cosTheta), Float32(0.5), Float32(-1.0)), Float32(1.0))) / cosTheta) / sqrt(Float32(pi))))) end
\begin{array}{l}
\\
\frac{1}{\left(1 + c\right) + \frac{\frac{\sqrt{\left(1 - cosTheta\right) - cosTheta} \cdot \mathsf{fma}\left(cosTheta \cdot cosTheta, \mathsf{fma}\left(cosTheta \cdot cosTheta, 0.5, -1\right), 1\right)}{cosTheta}}{\sqrt{\pi}}}
\end{array}
Initial program 97.7%
*-commutativeN/A
div-invN/A
associate-*l/N/A
/-lowering-/.f32N/A
associate-*l/N/A
/-lowering-/.f32N/A
*-lowering-*.f32N/A
sqrt-lowering-sqrt.f32N/A
--lowering--.f32N/A
--lowering--.f32N/A
exp-lowering-exp.f32N/A
*-commutativeN/A
*-lowering-*.f32N/A
neg-lowering-neg.f32N/A
sqrt-lowering-sqrt.f32N/A
Applied egg-rr98.2%
Taylor expanded in cosTheta around 0
+-commutativeN/A
accelerator-lowering-fma.f32N/A
unpow2N/A
*-lowering-*.f32N/A
sub-negN/A
*-commutativeN/A
metadata-evalN/A
accelerator-lowering-fma.f32N/A
unpow2N/A
*-lowering-*.f3297.5
Simplified97.5%
(FPCore (cosTheta c)
:precision binary32
(/
cosTheta
(fma
(sqrt (/ (fma cosTheta -2.0 1.0) PI))
(fma
(* cosTheta cosTheta)
(fma
(* cosTheta cosTheta)
(fma (* cosTheta cosTheta) -0.16666666666666666 0.5)
-1.0)
1.0)
cosTheta)))
float code(float cosTheta, float c) {
return cosTheta / fmaf(sqrtf((fmaf(cosTheta, -2.0f, 1.0f) / ((float) M_PI))), fmaf((cosTheta * cosTheta), fmaf((cosTheta * cosTheta), fmaf((cosTheta * cosTheta), -0.16666666666666666f, 0.5f), -1.0f), 1.0f), cosTheta);
}
function code(cosTheta, c) return Float32(cosTheta / fma(sqrt(Float32(fma(cosTheta, Float32(-2.0), Float32(1.0)) / Float32(pi))), fma(Float32(cosTheta * cosTheta), fma(Float32(cosTheta * cosTheta), fma(Float32(cosTheta * cosTheta), Float32(-0.16666666666666666), Float32(0.5)), Float32(-1.0)), Float32(1.0)), cosTheta)) end
\begin{array}{l}
\\
\frac{cosTheta}{\mathsf{fma}\left(\sqrt{\frac{\mathsf{fma}\left(cosTheta, -2, 1\right)}{\pi}}, \mathsf{fma}\left(cosTheta \cdot cosTheta, \mathsf{fma}\left(cosTheta \cdot cosTheta, \mathsf{fma}\left(cosTheta \cdot cosTheta, -0.16666666666666666, 0.5\right), -1\right), 1\right), cosTheta\right)}
\end{array}
Initial program 97.7%
Applied egg-rr98.1%
Taylor expanded in cosTheta around 0
+-commutativeN/A
accelerator-lowering-fma.f32N/A
unpow2N/A
*-lowering-*.f32N/A
sub-negN/A
metadata-evalN/A
accelerator-lowering-fma.f32N/A
unpow2N/A
*-lowering-*.f32N/A
+-commutativeN/A
*-commutativeN/A
accelerator-lowering-fma.f32N/A
unpow2N/A
*-lowering-*.f3297.8
Simplified97.8%
Taylor expanded in c around 0
/-lowering-/.f32N/A
+-commutativeN/A
accelerator-lowering-fma.f32N/A
Simplified97.4%
(FPCore (cosTheta c)
:precision binary32
(/
1.0
(+
(+ 1.0 c)
(/
(/ (fma cosTheta (fma cosTheta (fma cosTheta 0.5 -1.5) -1.0) 1.0) cosTheta)
(sqrt PI)))))
float code(float cosTheta, float c) {
return 1.0f / ((1.0f + c) + ((fmaf(cosTheta, fmaf(cosTheta, fmaf(cosTheta, 0.5f, -1.5f), -1.0f), 1.0f) / cosTheta) / sqrtf(((float) M_PI))));
}
function code(cosTheta, c) return Float32(Float32(1.0) / Float32(Float32(Float32(1.0) + c) + Float32(Float32(fma(cosTheta, fma(cosTheta, fma(cosTheta, Float32(0.5), Float32(-1.5)), Float32(-1.0)), Float32(1.0)) / cosTheta) / sqrt(Float32(pi))))) end
\begin{array}{l}
\\
\frac{1}{\left(1 + c\right) + \frac{\frac{\mathsf{fma}\left(cosTheta, \mathsf{fma}\left(cosTheta, \mathsf{fma}\left(cosTheta, 0.5, -1.5\right), -1\right), 1\right)}{cosTheta}}{\sqrt{\pi}}}
\end{array}
Initial program 97.7%
*-commutativeN/A
div-invN/A
associate-*l/N/A
/-lowering-/.f32N/A
associate-*l/N/A
/-lowering-/.f32N/A
*-lowering-*.f32N/A
sqrt-lowering-sqrt.f32N/A
--lowering--.f32N/A
--lowering--.f32N/A
exp-lowering-exp.f32N/A
*-commutativeN/A
*-lowering-*.f32N/A
neg-lowering-neg.f32N/A
sqrt-lowering-sqrt.f32N/A
Applied egg-rr98.2%
Taylor expanded in cosTheta around 0
/-lowering-/.f32N/A
+-commutativeN/A
accelerator-lowering-fma.f32N/A
sub-negN/A
metadata-evalN/A
accelerator-lowering-fma.f32N/A
sub-negN/A
*-commutativeN/A
metadata-evalN/A
accelerator-lowering-fma.f3296.7
Simplified96.7%
(FPCore (cosTheta c) :precision binary32 (/ cosTheta (fma (sqrt (/ (fma cosTheta -2.0 1.0) PI)) (- 1.0 (* cosTheta cosTheta)) cosTheta)))
float code(float cosTheta, float c) {
return cosTheta / fmaf(sqrtf((fmaf(cosTheta, -2.0f, 1.0f) / ((float) M_PI))), (1.0f - (cosTheta * cosTheta)), cosTheta);
}
function code(cosTheta, c) return Float32(cosTheta / fma(sqrt(Float32(fma(cosTheta, Float32(-2.0), Float32(1.0)) / Float32(pi))), Float32(Float32(1.0) - Float32(cosTheta * cosTheta)), cosTheta)) end
\begin{array}{l}
\\
\frac{cosTheta}{\mathsf{fma}\left(\sqrt{\frac{\mathsf{fma}\left(cosTheta, -2, 1\right)}{\pi}}, 1 - cosTheta \cdot cosTheta, cosTheta\right)}
\end{array}
Initial program 97.7%
Applied egg-rr98.1%
Taylor expanded in cosTheta around 0
+-commutativeN/A
mul-1-negN/A
unpow2N/A
distribute-rgt-neg-inN/A
mul-1-negN/A
accelerator-lowering-fma.f32N/A
mul-1-negN/A
neg-lowering-neg.f3296.6
Simplified96.6%
Taylor expanded in c around 0
/-lowering-/.f32N/A
+-commutativeN/A
accelerator-lowering-fma.f32N/A
Simplified96.5%
(FPCore (cosTheta c) :precision binary32 (/ cosTheta (+ cosTheta (/ (fma cosTheta (fma cosTheta -1.5 -1.0) 1.0) (sqrt PI)))))
float code(float cosTheta, float c) {
return cosTheta / (cosTheta + (fmaf(cosTheta, fmaf(cosTheta, -1.5f, -1.0f), 1.0f) / sqrtf(((float) M_PI))));
}
function code(cosTheta, c) return Float32(cosTheta / Float32(cosTheta + Float32(fma(cosTheta, fma(cosTheta, Float32(-1.5), Float32(-1.0)), Float32(1.0)) / sqrt(Float32(pi))))) end
\begin{array}{l}
\\
\frac{cosTheta}{cosTheta + \frac{\mathsf{fma}\left(cosTheta, \mathsf{fma}\left(cosTheta, -1.5, -1\right), 1\right)}{\sqrt{\pi}}}
\end{array}
Initial program 97.7%
Taylor expanded in cosTheta around 0
/-lowering-/.f32N/A
Simplified96.0%
Taylor expanded in c around 0
+-commutativeN/A
distribute-rgt1-inN/A
+-commutativeN/A
accelerator-lowering-fma.f32N/A
+-commutativeN/A
accelerator-lowering-fma.f32N/A
sub-negN/A
*-commutativeN/A
metadata-evalN/A
accelerator-lowering-fma.f32N/A
sqrt-lowering-sqrt.f32N/A
/-lowering-/.f32N/A
PI-lowering-PI.f3295.9
Simplified95.9%
clear-numN/A
/-lowering-/.f32N/A
+-commutativeN/A
+-lowering-+.f32N/A
sqrt-divN/A
metadata-evalN/A
un-div-invN/A
/-lowering-/.f32N/A
accelerator-lowering-fma.f32N/A
accelerator-lowering-fma.f32N/A
sqrt-lowering-sqrt.f32N/A
PI-lowering-PI.f3295.9
Applied egg-rr95.9%
(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 97.7%
Taylor expanded in cosTheta around 0
*-lowering-*.f32N/A
sqrt-lowering-sqrt.f32N/A
PI-lowering-PI.f3291.9
Simplified91.9%
(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 97.7%
Taylor expanded in c around inf
Simplified60.4%
Taylor expanded in cosTheta around 0
associate-*l/N/A
*-lft-identityN/A
/-lowering-/.f32N/A
sqrt-lowering-sqrt.f32N/A
/-lowering-/.f32N/A
PI-lowering-PI.f32N/A
*-commutativeN/A
*-lowering-*.f3253.6
Simplified53.6%
Taylor expanded in cosTheta around inf
Simplified11.0%
herbie shell --seed 2024198
(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))))))