
(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 11 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))
(* (* cosTheta (exp (* cosTheta cosTheta))) (sqrt PI))))))
float code(float cosTheta, float c) {
return 1.0f / ((1.0f + c) + (sqrtf(fmaf(cosTheta, -2.0f, 1.0f)) / ((cosTheta * expf((cosTheta * cosTheta))) * sqrtf(((float) M_PI)))));
}
function code(cosTheta, c) return Float32(Float32(1.0) / Float32(Float32(Float32(1.0) + c) + Float32(sqrt(fma(cosTheta, Float32(-2.0), Float32(1.0))) / Float32(Float32(cosTheta * exp(Float32(cosTheta * cosTheta))) * sqrt(Float32(pi)))))) end
\begin{array}{l}
\\
\frac{1}{\left(1 + c\right) + \frac{\sqrt{\mathsf{fma}\left(cosTheta, -2, 1\right)}}{\left(cosTheta \cdot e^{cosTheta \cdot cosTheta}\right) \cdot \sqrt{\pi}}}
\end{array}
Initial program 97.6%
lift-/.f32N/A
inv-powN/A
lift-sqrt.f32N/A
pow1/2N/A
pow-powN/A
rem-cube-cbrtN/A
lift-PI.f32N/A
pow-powN/A
lower-pow.f32N/A
lift-PI.f32N/A
lower-cbrt.f32N/A
metadata-evalN/A
metadata-eval98.0
Applied rewrites98.0%
Applied rewrites98.3%
(FPCore (cosTheta c)
:precision binary32
(/
1.0
(+
(+ 1.0 c)
(/
(sqrt (fma cosTheta -2.0 1.0))
(*
cosTheta
(fma
(* cosTheta cosTheta)
(fma
(* cosTheta cosTheta)
(fma
(sqrt PI)
0.5
(* (sqrt PI) (* (* cosTheta cosTheta) 0.16666666666666666)))
(sqrt PI))
(sqrt PI)))))))
float code(float cosTheta, float c) {
return 1.0f / ((1.0f + c) + (sqrtf(fmaf(cosTheta, -2.0f, 1.0f)) / (cosTheta * fmaf((cosTheta * cosTheta), fmaf((cosTheta * cosTheta), fmaf(sqrtf(((float) M_PI)), 0.5f, (sqrtf(((float) M_PI)) * ((cosTheta * cosTheta) * 0.16666666666666666f))), sqrtf(((float) M_PI))), sqrtf(((float) M_PI))))));
}
function code(cosTheta, c) return Float32(Float32(1.0) / Float32(Float32(Float32(1.0) + c) + Float32(sqrt(fma(cosTheta, Float32(-2.0), Float32(1.0))) / Float32(cosTheta * fma(Float32(cosTheta * cosTheta), fma(Float32(cosTheta * cosTheta), fma(sqrt(Float32(pi)), Float32(0.5), Float32(sqrt(Float32(pi)) * Float32(Float32(cosTheta * cosTheta) * Float32(0.16666666666666666)))), sqrt(Float32(pi))), sqrt(Float32(pi))))))) end
\begin{array}{l}
\\
\frac{1}{\left(1 + c\right) + \frac{\sqrt{\mathsf{fma}\left(cosTheta, -2, 1\right)}}{cosTheta \cdot \mathsf{fma}\left(cosTheta \cdot cosTheta, \mathsf{fma}\left(cosTheta \cdot cosTheta, \mathsf{fma}\left(\sqrt{\pi}, 0.5, \sqrt{\pi} \cdot \left(\left(cosTheta \cdot cosTheta\right) \cdot 0.16666666666666666\right)\right), \sqrt{\pi}\right), \sqrt{\pi}\right)}}
\end{array}
Initial program 97.6%
lift-/.f32N/A
inv-powN/A
lift-sqrt.f32N/A
pow1/2N/A
pow-powN/A
rem-cube-cbrtN/A
lift-PI.f32N/A
pow-powN/A
lower-pow.f32N/A
lift-PI.f32N/A
lower-cbrt.f32N/A
metadata-evalN/A
metadata-eval98.0
Applied rewrites98.0%
Applied rewrites98.3%
Taylor expanded in cosTheta around 0
lower-*.f32N/A
+-commutativeN/A
lower-fma.f32N/A
Applied rewrites98.0%
Final simplification98.0%
(FPCore (cosTheta c)
:precision binary32
(/
1.0
(+
(+ 1.0 c)
(/
(sqrt (fma cosTheta -2.0 1.0))
(*
cosTheta
(fma
(* cosTheta cosTheta)
(fma 0.5 (* (* cosTheta cosTheta) (sqrt PI)) (sqrt PI))
(sqrt PI)))))))
float code(float cosTheta, float c) {
return 1.0f / ((1.0f + c) + (sqrtf(fmaf(cosTheta, -2.0f, 1.0f)) / (cosTheta * fmaf((cosTheta * cosTheta), fmaf(0.5f, ((cosTheta * cosTheta) * sqrtf(((float) M_PI))), sqrtf(((float) M_PI))), sqrtf(((float) M_PI))))));
}
function code(cosTheta, c) return Float32(Float32(1.0) / Float32(Float32(Float32(1.0) + c) + Float32(sqrt(fma(cosTheta, Float32(-2.0), Float32(1.0))) / Float32(cosTheta * fma(Float32(cosTheta * cosTheta), fma(Float32(0.5), Float32(Float32(cosTheta * cosTheta) * sqrt(Float32(pi))), sqrt(Float32(pi))), sqrt(Float32(pi))))))) end
\begin{array}{l}
\\
\frac{1}{\left(1 + c\right) + \frac{\sqrt{\mathsf{fma}\left(cosTheta, -2, 1\right)}}{cosTheta \cdot \mathsf{fma}\left(cosTheta \cdot cosTheta, \mathsf{fma}\left(0.5, \left(cosTheta \cdot cosTheta\right) \cdot \sqrt{\pi}, \sqrt{\pi}\right), \sqrt{\pi}\right)}}
\end{array}
Initial program 97.6%
lift-/.f32N/A
inv-powN/A
lift-sqrt.f32N/A
pow1/2N/A
pow-powN/A
rem-cube-cbrtN/A
lift-PI.f32N/A
pow-powN/A
lower-pow.f32N/A
lift-PI.f32N/A
lower-cbrt.f32N/A
metadata-evalN/A
metadata-eval98.0
Applied rewrites98.0%
Applied rewrites98.3%
Taylor expanded in cosTheta around 0
lower-*.f32N/A
+-commutativeN/A
lower-fma.f32N/A
unpow2N/A
lower-*.f32N/A
+-commutativeN/A
lower-fma.f32N/A
lower-*.f32N/A
unpow2N/A
lower-*.f32N/A
lower-sqrt.f32N/A
lower-PI.f32N/A
lower-sqrt.f32N/A
lower-PI.f32N/A
lower-sqrt.f32N/A
lower-PI.f3297.7
Applied rewrites97.7%
(FPCore (cosTheta c)
:precision binary32
(/
1.0
(+
(+ 1.0 c)
(/
(*
(sqrt (fma cosTheta -2.0 1.0))
(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(fmaf(cosTheta, -2.0f, 1.0f)) * 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(sqrt(fma(cosTheta, Float32(-2.0), Float32(1.0))) * fma(Float32(cosTheta * cosTheta), fma(Float32(cosTheta * cosTheta), Float32(0.5), Float32(-1.0)), Float32(1.0))) / Float32(cosTheta * sqrt(Float32(pi)))))) end
\begin{array}{l}
\\
\frac{1}{\left(1 + c\right) + \frac{\sqrt{\mathsf{fma}\left(cosTheta, -2, 1\right)} \cdot \mathsf{fma}\left(cosTheta \cdot cosTheta, \mathsf{fma}\left(cosTheta \cdot cosTheta, 0.5, -1\right), 1\right)}{cosTheta \cdot \sqrt{\pi}}}
\end{array}
Initial program 97.6%
lift-/.f32N/A
inv-powN/A
lift-sqrt.f32N/A
pow1/2N/A
pow-powN/A
rem-cube-cbrtN/A
lift-PI.f32N/A
pow-powN/A
lower-pow.f32N/A
lift-PI.f32N/A
lower-cbrt.f32N/A
metadata-evalN/A
metadata-eval98.0
Applied rewrites98.0%
lift-*.f32N/A
lift-*.f32N/A
lift-/.f32N/A
associate-*r/N/A
associate-*l/N/A
Applied rewrites98.3%
Taylor expanded in cosTheta around 0
+-commutativeN/A
lower-fma.f32N/A
unpow2N/A
lower-*.f32N/A
sub-negN/A
*-commutativeN/A
metadata-evalN/A
lower-fma.f32N/A
unpow2N/A
lower-*.f3297.7
Applied rewrites97.7%
(FPCore (cosTheta c)
:precision binary32
(/
1.0
(fma
(/
(fma (* cosTheta cosTheta) (fma (* cosTheta cosTheta) 0.5 -1.0) 1.0)
cosTheta)
(sqrt (/ (fma cosTheta -2.0 1.0) PI))
(+ 1.0 c))))
float code(float cosTheta, float c) {
return 1.0f / fmaf((fmaf((cosTheta * cosTheta), fmaf((cosTheta * cosTheta), 0.5f, -1.0f), 1.0f) / cosTheta), sqrtf((fmaf(cosTheta, -2.0f, 1.0f) / ((float) M_PI))), (1.0f + c));
}
function code(cosTheta, c) return Float32(Float32(1.0) / fma(Float32(fma(Float32(cosTheta * cosTheta), fma(Float32(cosTheta * cosTheta), Float32(0.5), Float32(-1.0)), Float32(1.0)) / cosTheta), sqrt(Float32(fma(cosTheta, Float32(-2.0), Float32(1.0)) / Float32(pi))), Float32(Float32(1.0) + c))) end
\begin{array}{l}
\\
\frac{1}{\mathsf{fma}\left(\frac{\mathsf{fma}\left(cosTheta \cdot cosTheta, \mathsf{fma}\left(cosTheta \cdot cosTheta, 0.5, -1\right), 1\right)}{cosTheta}, \sqrt{\frac{\mathsf{fma}\left(cosTheta, -2, 1\right)}{\pi}}, 1 + c\right)}
\end{array}
Initial program 97.6%
Taylor expanded in c around 0
associate-+r+N/A
+-commutativeN/A
lower-fma.f32N/A
Applied rewrites97.7%
Taylor expanded in cosTheta around 0
Applied rewrites97.1%
(FPCore (cosTheta c)
:precision binary32
(/
1.0
(+
(+ 1.0 c)
(/
(sqrt (fma cosTheta -2.0 1.0))
(* cosTheta (* (sqrt PI) (fma cosTheta cosTheta 1.0)))))))
float code(float cosTheta, float c) {
return 1.0f / ((1.0f + c) + (sqrtf(fmaf(cosTheta, -2.0f, 1.0f)) / (cosTheta * (sqrtf(((float) M_PI)) * fmaf(cosTheta, cosTheta, 1.0f)))));
}
function code(cosTheta, c) return Float32(Float32(1.0) / Float32(Float32(Float32(1.0) + c) + Float32(sqrt(fma(cosTheta, Float32(-2.0), Float32(1.0))) / Float32(cosTheta * Float32(sqrt(Float32(pi)) * fma(cosTheta, cosTheta, Float32(1.0))))))) end
\begin{array}{l}
\\
\frac{1}{\left(1 + c\right) + \frac{\sqrt{\mathsf{fma}\left(cosTheta, -2, 1\right)}}{cosTheta \cdot \left(\sqrt{\pi} \cdot \mathsf{fma}\left(cosTheta, cosTheta, 1\right)\right)}}
\end{array}
Initial program 97.6%
lift-/.f32N/A
inv-powN/A
lift-sqrt.f32N/A
pow1/2N/A
pow-powN/A
rem-cube-cbrtN/A
lift-PI.f32N/A
pow-powN/A
lower-pow.f32N/A
lift-PI.f32N/A
lower-cbrt.f32N/A
metadata-evalN/A
metadata-eval98.0
Applied rewrites98.0%
Applied rewrites98.3%
Taylor expanded in cosTheta around 0
lower-*.f32N/A
distribute-rgt1-inN/A
lower-*.f32N/A
unpow2N/A
lower-fma.f32N/A
lower-sqrt.f32N/A
lower-PI.f3297.1
Applied rewrites97.1%
Final simplification97.1%
(FPCore (cosTheta c) :precision binary32 (/ 1.0 (fma (/ (fma cosTheta (- cosTheta) 1.0) cosTheta) (sqrt (/ (fma cosTheta -2.0 1.0) PI)) (+ 1.0 c))))
float code(float cosTheta, float c) {
return 1.0f / fmaf((fmaf(cosTheta, -cosTheta, 1.0f) / cosTheta), sqrtf((fmaf(cosTheta, -2.0f, 1.0f) / ((float) M_PI))), (1.0f + c));
}
function code(cosTheta, c) return Float32(Float32(1.0) / fma(Float32(fma(cosTheta, Float32(-cosTheta), Float32(1.0)) / cosTheta), sqrt(Float32(fma(cosTheta, Float32(-2.0), Float32(1.0)) / Float32(pi))), Float32(Float32(1.0) + c))) end
\begin{array}{l}
\\
\frac{1}{\mathsf{fma}\left(\frac{\mathsf{fma}\left(cosTheta, -cosTheta, 1\right)}{cosTheta}, \sqrt{\frac{\mathsf{fma}\left(cosTheta, -2, 1\right)}{\pi}}, 1 + c\right)}
\end{array}
Initial program 97.6%
Taylor expanded in c around 0
associate-+r+N/A
+-commutativeN/A
lower-fma.f32N/A
Applied rewrites97.7%
Taylor expanded in cosTheta around 0
Applied rewrites96.4%
(FPCore (cosTheta c) :precision binary32 (/ 1.0 (fma (fma cosTheta (- cosTheta) 1.0) (/ (sqrt (/ (fma cosTheta -2.0 1.0) PI)) cosTheta) 1.0)))
float code(float cosTheta, float c) {
return 1.0f / fmaf(fmaf(cosTheta, -cosTheta, 1.0f), (sqrtf((fmaf(cosTheta, -2.0f, 1.0f) / ((float) M_PI))) / cosTheta), 1.0f);
}
function code(cosTheta, c) return Float32(Float32(1.0) / fma(fma(cosTheta, Float32(-cosTheta), Float32(1.0)), Float32(sqrt(Float32(fma(cosTheta, Float32(-2.0), Float32(1.0)) / Float32(pi))) / cosTheta), Float32(1.0))) end
\begin{array}{l}
\\
\frac{1}{\mathsf{fma}\left(\mathsf{fma}\left(cosTheta, -cosTheta, 1\right), \frac{\sqrt{\frac{\mathsf{fma}\left(cosTheta, -2, 1\right)}{\pi}}}{cosTheta}, 1\right)}
\end{array}
Initial program 97.6%
lift-/.f32N/A
inv-powN/A
lift-sqrt.f32N/A
pow1/2N/A
pow-powN/A
rem-cube-cbrtN/A
lift-PI.f32N/A
pow-powN/A
lower-pow.f32N/A
lift-PI.f32N/A
lower-cbrt.f32N/A
metadata-evalN/A
metadata-eval98.0
Applied rewrites98.0%
Applied rewrites98.3%
Taylor expanded in c around 0
+-commutativeN/A
associate-*l/N/A
metadata-evalN/A
cancel-sign-sub-invN/A
*-commutativeN/A
times-fracN/A
exp-negN/A
neg-mul-1N/A
lower-fma.f32N/A
Applied rewrites97.4%
Taylor expanded in cosTheta around 0
Applied rewrites96.2%
(FPCore (cosTheta c) :precision binary32 (* cosTheta (fma (fma PI (- c (sqrt (/ 1.0 PI))) PI) (- cosTheta) (sqrt PI))))
float code(float cosTheta, float c) {
return cosTheta * fmaf(fmaf(((float) M_PI), (c - sqrtf((1.0f / ((float) M_PI)))), ((float) M_PI)), -cosTheta, sqrtf(((float) M_PI)));
}
function code(cosTheta, c) return Float32(cosTheta * fma(fma(Float32(pi), Float32(c - sqrt(Float32(Float32(1.0) / Float32(pi)))), Float32(pi)), Float32(-cosTheta), sqrt(Float32(pi)))) end
\begin{array}{l}
\\
cosTheta \cdot \mathsf{fma}\left(\mathsf{fma}\left(\pi, c - \sqrt{\frac{1}{\pi}}, \pi\right), -cosTheta, \sqrt{\pi}\right)
\end{array}
Initial program 97.6%
Taylor expanded in cosTheta around 0
lower-*.f32N/A
+-commutativeN/A
associate-*r*N/A
*-commutativeN/A
lower-fma.f32N/A
Applied rewrites95.2%
(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 97.6%
Taylor expanded in cosTheta around 0
lower-*.f32N/A
lower-sqrt.f32N/A
lower-PI.f3292.9
Applied rewrites92.9%
(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}
\\
\frac{1}{c}
\end{array}
Initial program 97.6%
Taylor expanded in c around inf
lower-/.f324.9
Applied rewrites4.9%
herbie shell --seed 2024237
(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))))))