
(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 13 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
(cast
(!
:precision
binary64
(/
1.0
(+
c
(+
1.0
(/
(sqrt (/ (fma -2.0 cosTheta 1.0) PI))
(* cosTheta (exp (pow cosTheta 2.0))))))))))
float code(float cosTheta, float c) {
double tmp = 1.0 / (((double) c) + (1.0 + (sqrt((fma(-2.0, cosTheta, 1.0) / ((double) M_PI))) / (((double) cosTheta) * exp(pow(cosTheta, 2.0))))));
return (float) tmp;
}
function code(cosTheta, c) tmp = Float64(1.0 / Float64(Float64(c) + Float64(1.0 + Float64(sqrt(Float64(fma(-2.0, cosTheta, 1.0) / pi)) / Float64(Float64(cosTheta) * exp((cosTheta ^ 2.0))))))) return Float32(tmp) end
\begin{array}{l}
\\
\langle \left( \frac{1}{c + \left(1 + \frac{\sqrt{\frac{\mathsf{fma}\left(-2, cosTheta, 1\right)}{\pi}}}{cosTheta \cdot e^{{cosTheta}^{2}}}\right)} \right)_{\text{binary64}} \rangle_{\text{binary32}}
\end{array}
Initial program 99.5%
div-inv99.5%
associate-+l+99.5%
associate-/r*99.5%
associate-/l/99.5%
Applied egg-rr99.5%
*-lft-identity99.5%
+-commutative99.5%
associate-+l+99.5%
fma-udef99.5%
*-commutative99.5%
fma-def99.5%
*-commutative99.5%
Simplified99.5%
Final simplification99.5%
(FPCore (cosTheta c)
:precision binary32
(/
1.0
(+
(+ 1.0 c)
(*
(cast
(!
:precision
binary64
(* (/ 1.0 (sqrt PI)) (/ (sqrt (- 1.0 (* cosTheta 2.0))) cosTheta))))
(exp (- (* cosTheta cosTheta)))))))
float code(float cosTheta, float c) {
double tmp = (1.0 / sqrt(((double) M_PI))) * (sqrt((1.0 - (((double) cosTheta) * 2.0))) / ((double) cosTheta));
return 1.0f / ((1.0f + c) + (((float) tmp) * expf(-(cosTheta * cosTheta))));
}
function code(cosTheta, c) tmp = Float64(Float64(1.0 / sqrt(pi)) * Float64(sqrt(Float64(1.0 - Float64(Float64(cosTheta) * 2.0))) / Float64(cosTheta))) return Float32(Float32(1.0) / Float32(Float32(Float32(1.0) + c) + Float32(Float32(tmp) * exp(Float32(-Float32(cosTheta * cosTheta)))))) end
function tmp_2 = code(cosTheta, c) tmp = (1.0 / sqrt(pi)) * (sqrt((1.0 - (double(cosTheta) * 2.0))) / double(cosTheta)); tmp_2 = single(1.0) / ((single(1.0) + c) + single((single(tmp) * double(exp(-(cosTheta * cosTheta)))))); end
\begin{array}{l}
\\
\frac{1}{\left(1 + c\right) + \langle \left( \left(\frac{1}{\sqrt{\pi}} \cdot \frac{\sqrt{1 - cosTheta \cdot 2}}{cosTheta}\right) \right)_{\text{binary64}} \rangle_{\text{binary32}} \cdot e^{-cosTheta \cdot cosTheta}}
\end{array}
Initial program 97.9%
rewrite-binary32/binary6498.9%
Applied rewrite-once98.9%
associate--r+98.9%
count-298.9%
Simplified98.9%
Final simplification98.9%
(FPCore (cosTheta c)
:precision binary32
(/
1.0
(+
(+ 1.0 c)
(/
(/
(sqrt (+ 1.0 (* -2.0 cosTheta)))
(cast (! :precision binary64 (* cosTheta (sqrt PI)))))
(pow (exp cosTheta) cosTheta)))))
float code(float cosTheta, float c) {
double tmp = ((double) cosTheta) * sqrt(((double) M_PI));
return 1.0f / ((1.0f + c) + ((sqrtf((1.0f + (-2.0f * cosTheta))) / ((float) tmp)) / powf(expf(cosTheta), cosTheta)));
}
function code(cosTheta, c) tmp = Float64(Float64(cosTheta) * sqrt(pi)) return Float32(Float32(1.0) / Float32(Float32(Float32(1.0) + c) + Float32(Float32(sqrt(Float32(Float32(1.0) + Float32(Float32(-2.0) * cosTheta))) / Float32(tmp)) / (exp(cosTheta) ^ cosTheta)))) end
function tmp_2 = code(cosTheta, c) tmp = double(cosTheta) * sqrt(pi); tmp_2 = single(1.0) / ((single(1.0) + c) + (single((double(sqrt((single(1.0) + (single(-2.0) * cosTheta)))) / single(tmp))) / (exp(cosTheta) ^ cosTheta))); end
\begin{array}{l}
\\
\frac{1}{\left(1 + c\right) + \frac{\frac{\sqrt{1 + -2 \cdot cosTheta}}{\langle \left( cosTheta \cdot \sqrt{\pi} \right)_{\text{binary64}} \rangle_{\text{binary32}}}}{{\left(e^{cosTheta}\right)}^{cosTheta}}}
\end{array}
Initial program 97.9%
*-commutative97.9%
associate-*l*97.9%
/-rgt-identity97.9%
associate-/r/97.9%
exp-neg97.9%
distribute-lft-neg-out97.9%
remove-double-neg97.9%
associate-*r/97.9%
*-commutative97.9%
Simplified98.5%
rewrite-binary32/binary6498.9%
Applied rewrite-once98.9%
Final simplification98.9%
(FPCore (cosTheta c)
:precision binary32
(/
1.0
(+
(+ 1.0 c)
(/
(/ (sqrt (+ 1.0 (* -2.0 cosTheta))) (* cosTheta (sqrt PI)))
(pow (exp cosTheta) cosTheta)))))
float code(float cosTheta, float c) {
return 1.0f / ((1.0f + c) + ((sqrtf((1.0f + (-2.0f * cosTheta))) / (cosTheta * sqrtf(((float) M_PI)))) / powf(expf(cosTheta), cosTheta)));
}
function code(cosTheta, c) return Float32(Float32(1.0) / Float32(Float32(Float32(1.0) + c) + Float32(Float32(sqrt(Float32(Float32(1.0) + Float32(Float32(-2.0) * cosTheta))) / Float32(cosTheta * sqrt(Float32(pi)))) / (exp(cosTheta) ^ cosTheta)))) end
function tmp = code(cosTheta, c) tmp = single(1.0) / ((single(1.0) + c) + ((sqrt((single(1.0) + (single(-2.0) * cosTheta))) / (cosTheta * sqrt(single(pi)))) / (exp(cosTheta) ^ cosTheta))); end
\begin{array}{l}
\\
\frac{1}{\left(1 + c\right) + \frac{\frac{\sqrt{1 + -2 \cdot cosTheta}}{cosTheta \cdot \sqrt{\pi}}}{{\left(e^{cosTheta}\right)}^{cosTheta}}}
\end{array}
Initial program 97.9%
*-commutative97.9%
associate-*l*97.9%
/-rgt-identity97.9%
associate-/r/97.9%
exp-neg97.9%
distribute-lft-neg-out97.9%
remove-double-neg97.9%
associate-*r/97.9%
*-commutative97.9%
Simplified98.5%
Final simplification98.5%
(FPCore (cosTheta c)
:precision binary32
(/
1.0
(+
(+ 1.0 c)
(*
(exp (- (* cosTheta cosTheta)))
(* (pow PI -0.5) (/ (sqrt (- (- 1.0 cosTheta) cosTheta)) cosTheta))))))
float code(float cosTheta, float c) {
return 1.0f / ((1.0f + c) + (expf(-(cosTheta * cosTheta)) * (powf(((float) M_PI), -0.5f) * (sqrtf(((1.0f - cosTheta) - cosTheta)) / cosTheta))));
}
function code(cosTheta, c) return Float32(Float32(1.0) / Float32(Float32(Float32(1.0) + c) + Float32(exp(Float32(-Float32(cosTheta * cosTheta))) * Float32((Float32(pi) ^ Float32(-0.5)) * Float32(sqrt(Float32(Float32(Float32(1.0) - cosTheta) - cosTheta)) / cosTheta))))) end
function tmp = code(cosTheta, c) tmp = single(1.0) / ((single(1.0) + c) + (exp(-(cosTheta * cosTheta)) * ((single(pi) ^ single(-0.5)) * (sqrt(((single(1.0) - cosTheta) - cosTheta)) / cosTheta)))); end
\begin{array}{l}
\\
\frac{1}{\left(1 + c\right) + e^{-cosTheta \cdot cosTheta} \cdot \left({\pi}^{-0.5} \cdot \frac{\sqrt{\left(1 - cosTheta\right) - cosTheta}}{cosTheta}\right)}
\end{array}
Initial program 97.9%
div-inv96.5%
pow1/296.5%
pow-flip96.5%
metadata-eval96.5%
Applied egg-rr97.9%
*-lft-identity96.5%
Simplified97.9%
Final simplification97.9%
(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%
Taylor expanded in c around 0 97.8%
mul-1-neg97.8%
exp-neg97.8%
unpow297.8%
exp-prod97.8%
associate-/r*97.8%
exp-prod97.8%
unpow297.8%
*-commutative97.8%
cancel-sign-sub-inv97.8%
metadata-eval97.8%
Simplified97.9%
Final simplification97.9%
(FPCore (cosTheta c)
:precision binary32
(/
1.0
(+
(+ 1.0 c)
(*
(pow PI -0.5)
(+
(+ -1.0 (fma 0.5 (* cosTheta cosTheta) (/ 1.0 cosTheta)))
(* cosTheta -1.5))))))
float code(float cosTheta, float c) {
return 1.0f / ((1.0f + c) + (powf(((float) M_PI), -0.5f) * ((-1.0f + fmaf(0.5f, (cosTheta * cosTheta), (1.0f / cosTheta))) + (cosTheta * -1.5f))));
}
function code(cosTheta, c) return Float32(Float32(1.0) / Float32(Float32(Float32(1.0) + c) + Float32((Float32(pi) ^ Float32(-0.5)) * Float32(Float32(Float32(-1.0) + fma(Float32(0.5), Float32(cosTheta * cosTheta), Float32(Float32(1.0) / cosTheta))) + Float32(cosTheta * Float32(-1.5)))))) end
\begin{array}{l}
\\
\frac{1}{\left(1 + c\right) + {\pi}^{-0.5} \cdot \left(\left(-1 + \mathsf{fma}\left(0.5, cosTheta \cdot cosTheta, \frac{1}{cosTheta}\right)\right) + cosTheta \cdot -1.5\right)}
\end{array}
Initial program 97.9%
associate-*l*97.9%
associate--l-97.9%
*-commutative97.9%
exp-prod97.9%
Simplified97.9%
Taylor expanded in cosTheta around 0 96.5%
associate--l+96.5%
distribute-lft-in96.5%
inv-pow96.5%
sqrt-pow296.5%
metadata-eval96.5%
*-commutative96.5%
inv-pow96.5%
sqrt-pow296.5%
metadata-eval96.5%
sub-neg96.5%
fma-def96.5%
unpow296.5%
metadata-eval96.5%
Applied egg-rr96.5%
distribute-lft-out96.5%
+-commutative96.5%
Simplified96.5%
Final simplification96.5%
(FPCore (cosTheta c)
:precision binary32
(/
1.0
(+
(+ 1.0 c)
(*
(pow PI -0.5)
(+
-1.0
(+
(* cosTheta -1.5)
(+ (/ 1.0 cosTheta) (* (* cosTheta cosTheta) 0.5))))))))
float code(float cosTheta, float c) {
return 1.0f / ((1.0f + c) + (powf(((float) M_PI), -0.5f) * (-1.0f + ((cosTheta * -1.5f) + ((1.0f / cosTheta) + ((cosTheta * cosTheta) * 0.5f))))));
}
function code(cosTheta, c) return Float32(Float32(1.0) / Float32(Float32(Float32(1.0) + c) + Float32((Float32(pi) ^ Float32(-0.5)) * Float32(Float32(-1.0) + Float32(Float32(cosTheta * Float32(-1.5)) + Float32(Float32(Float32(1.0) / cosTheta) + Float32(Float32(cosTheta * cosTheta) * Float32(0.5)))))))) end
function tmp = code(cosTheta, c) tmp = single(1.0) / ((single(1.0) + c) + ((single(pi) ^ single(-0.5)) * (single(-1.0) + ((cosTheta * single(-1.5)) + ((single(1.0) / cosTheta) + ((cosTheta * cosTheta) * single(0.5))))))); end
\begin{array}{l}
\\
\frac{1}{\left(1 + c\right) + {\pi}^{-0.5} \cdot \left(-1 + \left(cosTheta \cdot -1.5 + \left(\frac{1}{cosTheta} + \left(cosTheta \cdot cosTheta\right) \cdot 0.5\right)\right)\right)}
\end{array}
Initial program 97.9%
associate-*l*97.9%
associate--l-97.9%
*-commutative97.9%
exp-prod97.9%
Simplified97.9%
Taylor expanded in cosTheta around 0 96.5%
add-exp-log_binary3296.5%
Applied rewrite-once96.5%
rem-exp-log96.5%
*-commutative96.5%
unpow296.5%
Simplified96.5%
div-inv96.5%
pow1/296.5%
pow-flip96.5%
metadata-eval96.5%
Applied egg-rr96.5%
*-lft-identity96.5%
Simplified96.5%
Final simplification96.5%
(FPCore (cosTheta c) :precision binary32 (/ 1.0 (+ (+ 1.0 c) (* (/ 1.0 (sqrt PI)) (+ -1.0 (+ (/ 1.0 cosTheta) (* cosTheta -1.5)))))))
float code(float cosTheta, float c) {
return 1.0f / ((1.0f + c) + ((1.0f / sqrtf(((float) M_PI))) * (-1.0f + ((1.0f / cosTheta) + (cosTheta * -1.5f)))));
}
function code(cosTheta, c) return Float32(Float32(1.0) / Float32(Float32(Float32(1.0) + c) + Float32(Float32(Float32(1.0) / sqrt(Float32(pi))) * Float32(Float32(-1.0) + Float32(Float32(Float32(1.0) / cosTheta) + Float32(cosTheta * Float32(-1.5))))))) end
function tmp = code(cosTheta, c) tmp = single(1.0) / ((single(1.0) + c) + ((single(1.0) / sqrt(single(pi))) * (single(-1.0) + ((single(1.0) / cosTheta) + (cosTheta * single(-1.5)))))); end
\begin{array}{l}
\\
\frac{1}{\left(1 + c\right) + \frac{1}{\sqrt{\pi}} \cdot \left(-1 + \left(\frac{1}{cosTheta} + cosTheta \cdot -1.5\right)\right)}
\end{array}
Initial program 97.9%
associate-*l*97.9%
associate--l-97.9%
*-commutative97.9%
exp-prod97.9%
Simplified97.9%
Taylor expanded in cosTheta around 0 95.8%
Final simplification95.8%
(FPCore (cosTheta c) :precision binary32 (/ 1.0 (+ (+ 1.0 c) (* (/ 1.0 (sqrt PI)) (+ -1.0 (/ 1.0 cosTheta))))))
float code(float cosTheta, float c) {
return 1.0f / ((1.0f + c) + ((1.0f / sqrtf(((float) M_PI))) * (-1.0f + (1.0f / cosTheta))));
}
function code(cosTheta, c) return Float32(Float32(1.0) / Float32(Float32(Float32(1.0) + c) + Float32(Float32(Float32(1.0) / sqrt(Float32(pi))) * Float32(Float32(-1.0) + Float32(Float32(1.0) / cosTheta))))) end
function tmp = code(cosTheta, c) tmp = single(1.0) / ((single(1.0) + c) + ((single(1.0) / sqrt(single(pi))) * (single(-1.0) + (single(1.0) / cosTheta)))); end
\begin{array}{l}
\\
\frac{1}{\left(1 + c\right) + \frac{1}{\sqrt{\pi}} \cdot \left(-1 + \frac{1}{cosTheta}\right)}
\end{array}
Initial program 97.9%
associate-*l*97.9%
associate--l-97.9%
*-commutative97.9%
exp-prod97.9%
Simplified97.9%
Taylor expanded in cosTheta around 0 94.4%
Final simplification94.4%
(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%
Taylor expanded in cosTheta around 0 92.8%
Final simplification92.8%
(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%
Taylor expanded in cosTheta around inf 10.8%
Taylor expanded in c around 0 10.8%
neg-mul-110.8%
sub-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%
Taylor expanded in cosTheta around inf 10.8%
Taylor expanded in c around 0 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))))))