
(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)
(*
(/
(/
(* (pow PI -0.16666666666666666) (sqrt (- 1.0 (* cosTheta 2.0))))
cosTheta)
(cbrt PI))
(exp (* cosTheta (- cosTheta)))))))
float code(float cosTheta, float c) {
return 1.0f / ((1.0f + c) + ((((powf(((float) M_PI), -0.16666666666666666f) * sqrtf((1.0f - (cosTheta * 2.0f)))) / cosTheta) / cbrtf(((float) M_PI))) * expf((cosTheta * -cosTheta))));
}
function code(cosTheta, c) return Float32(Float32(1.0) / Float32(Float32(Float32(1.0) + c) + Float32(Float32(Float32(Float32((Float32(pi) ^ Float32(-0.16666666666666666)) * sqrt(Float32(Float32(1.0) - Float32(cosTheta * Float32(2.0))))) / cosTheta) / cbrt(Float32(pi))) * exp(Float32(cosTheta * Float32(-cosTheta)))))) end
\begin{array}{l}
\\
\frac{1}{\left(1 + c\right) + \frac{\frac{{\pi}^{-0.16666666666666666} \cdot \sqrt{1 - cosTheta \cdot 2}}{cosTheta}}{\sqrt[3]{\pi}} \cdot e^{cosTheta \cdot \left(-cosTheta\right)}}
\end{array}
Initial program 97.6%
add-cube-cbrt97.6%
cbrt-unprod97.6%
frac-times97.8%
metadata-eval97.8%
add-sqr-sqrt97.8%
inv-pow97.8%
sqrt-pow297.8%
metadata-eval97.8%
Applied egg-rr97.8%
associate-*l*98.3%
cbrt-div98.3%
metadata-eval98.3%
pow1/398.3%
pow-pow98.3%
metadata-eval98.3%
associate--l-98.3%
add-log-exp98.3%
add-log-exp98.3%
sum-log98.3%
exp-lft-sqr98.4%
add-log-exp98.3%
Applied egg-rr98.3%
Applied egg-rr98.3%
associate-*l/98.4%
*-lft-identity98.4%
associate-*r/98.5%
Simplified98.5%
Final simplification98.5%
(FPCore (cosTheta c)
:precision binary32
(/
1.0
(+
(+ 1.0 c)
(*
(exp (* cosTheta (- cosTheta)))
(/
(*
(sqrt (- 1.0 (* cosTheta 2.0)))
(/ (pow PI -0.16666666666666666) (cbrt PI)))
cosTheta)))))
float code(float cosTheta, float c) {
return 1.0f / ((1.0f + c) + (expf((cosTheta * -cosTheta)) * ((sqrtf((1.0f - (cosTheta * 2.0f))) * (powf(((float) M_PI), -0.16666666666666666f) / cbrtf(((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(Float32(sqrt(Float32(Float32(1.0) - Float32(cosTheta * Float32(2.0)))) * Float32((Float32(pi) ^ Float32(-0.16666666666666666)) / cbrt(Float32(pi)))) / cosTheta)))) end
\begin{array}{l}
\\
\frac{1}{\left(1 + c\right) + e^{cosTheta \cdot \left(-cosTheta\right)} \cdot \frac{\sqrt{1 - cosTheta \cdot 2} \cdot \frac{{\pi}^{-0.16666666666666666}}{\sqrt[3]{\pi}}}{cosTheta}}
\end{array}
Initial program 97.6%
add-cube-cbrt97.6%
cbrt-unprod97.6%
frac-times97.8%
metadata-eval97.8%
add-sqr-sqrt97.8%
inv-pow97.8%
sqrt-pow297.8%
metadata-eval97.8%
Applied egg-rr97.8%
associate-*r/97.7%
inv-pow97.7%
metadata-eval97.7%
pow-prod-up97.7%
cbrt-unprod97.7%
add-cube-cbrt97.7%
associate--l-97.7%
add-log-exp97.6%
add-log-exp97.7%
sum-log97.7%
exp-lft-sqr97.8%
add-log-exp97.7%
Applied egg-rr97.7%
add-cube-cbrt97.7%
cbrt-unprod97.7%
pow-prod-up97.7%
metadata-eval97.7%
inv-pow97.7%
*-commutative97.7%
pow1/397.7%
pow-pow97.7%
metadata-eval97.7%
cbrt-div97.7%
metadata-eval97.7%
Applied egg-rr97.7%
associate-*r/97.7%
*-rgt-identity97.7%
Simplified97.7%
Final simplification97.7%
(FPCore (cosTheta c)
:precision binary32
(/
1.0
(+
1.0
(+
c
(*
(sqrt (/ (+ 1.0 (* cosTheta -2.0)) PI))
(/ (exp (- (pow cosTheta 2.0))) cosTheta))))))
float code(float cosTheta, float c) {
return 1.0f / (1.0f + (c + (sqrtf(((1.0f + (cosTheta * -2.0f)) / ((float) M_PI))) * (expf(-powf(cosTheta, 2.0f)) / cosTheta))));
}
function code(cosTheta, c) return Float32(Float32(1.0) / Float32(Float32(1.0) + Float32(c + Float32(sqrt(Float32(Float32(Float32(1.0) + Float32(cosTheta * Float32(-2.0))) / Float32(pi))) * Float32(exp(Float32(-(cosTheta ^ Float32(2.0)))) / cosTheta))))) end
function tmp = code(cosTheta, c) tmp = single(1.0) / (single(1.0) + (c + (sqrt(((single(1.0) + (cosTheta * single(-2.0))) / single(pi))) * (exp(-(cosTheta ^ single(2.0))) / cosTheta)))); end
\begin{array}{l}
\\
\frac{1}{1 + \left(c + \sqrt{\frac{1 + cosTheta \cdot -2}{\pi}} \cdot \frac{e^{-{cosTheta}^{2}}}{cosTheta}\right)}
\end{array}
Initial program 97.6%
associate-+l+97.6%
+-commutative97.6%
*-commutative97.6%
associate-*l*97.6%
fma-define97.6%
Simplified97.6%
Taylor expanded in c around 0 97.7%
Final simplification97.7%
(FPCore (cosTheta c)
:precision binary32
(/
1.0
(+
1.0
(*
(sqrt (/ (- 1.0 (* cosTheta 2.0)) PI))
(/ (exp (- (pow cosTheta 2.0))) cosTheta)))))
float code(float cosTheta, float c) {
return 1.0f / (1.0f + (sqrtf(((1.0f - (cosTheta * 2.0f)) / ((float) M_PI))) * (expf(-powf(cosTheta, 2.0f)) / cosTheta)));
}
function code(cosTheta, c) return Float32(Float32(1.0) / Float32(Float32(1.0) + Float32(sqrt(Float32(Float32(Float32(1.0) - Float32(cosTheta * Float32(2.0))) / Float32(pi))) * Float32(exp(Float32(-(cosTheta ^ Float32(2.0)))) / cosTheta)))) end
function tmp = code(cosTheta, c) tmp = single(1.0) / (single(1.0) + (sqrt(((single(1.0) - (cosTheta * single(2.0))) / single(pi))) * (exp(-(cosTheta ^ single(2.0))) / cosTheta))); end
\begin{array}{l}
\\
\frac{1}{1 + \sqrt{\frac{1 - cosTheta \cdot 2}{\pi}} \cdot \frac{e^{-{cosTheta}^{2}}}{cosTheta}}
\end{array}
Initial program 97.6%
add-cube-cbrt97.6%
cbrt-unprod97.6%
frac-times97.8%
metadata-eval97.8%
add-sqr-sqrt97.8%
inv-pow97.8%
sqrt-pow297.8%
metadata-eval97.8%
Applied egg-rr97.8%
associate-*l*98.3%
cbrt-div98.3%
metadata-eval98.3%
pow1/398.3%
pow-pow98.3%
metadata-eval98.3%
associate--l-98.3%
add-log-exp98.3%
add-log-exp98.3%
sum-log98.3%
exp-lft-sqr98.4%
add-log-exp98.3%
Applied egg-rr98.3%
Taylor expanded in c around 0 97.4%
neg-mul-197.4%
rem-exp-log90.4%
exp-neg90.4%
log1p-define90.4%
*-commutative90.4%
Simplified90.4%
exp-neg90.3%
log1p-undefine90.4%
rem-exp-log97.4%
Applied egg-rr97.4%
(FPCore (cosTheta c)
:precision binary32
(/
1.0
(+
(+ 1.0 c)
(*
(exp (* cosTheta (- cosTheta)))
(/
(*
(pow PI -0.5)
(+ 1.0 (* cosTheta (+ -1.0 (* cosTheta (- (* cosTheta -0.5) 0.5))))))
cosTheta)))))
float code(float cosTheta, float c) {
return 1.0f / ((1.0f + c) + (expf((cosTheta * -cosTheta)) * ((powf(((float) M_PI), -0.5f) * (1.0f + (cosTheta * (-1.0f + (cosTheta * ((cosTheta * -0.5f) - 0.5f)))))) / cosTheta)));
}
function code(cosTheta, c) return Float32(Float32(1.0) / Float32(Float32(Float32(1.0) + c) + Float32(exp(Float32(cosTheta * Float32(-cosTheta))) * Float32(Float32((Float32(pi) ^ Float32(-0.5)) * Float32(Float32(1.0) + Float32(cosTheta * Float32(Float32(-1.0) + Float32(cosTheta * Float32(Float32(cosTheta * Float32(-0.5)) - Float32(0.5))))))) / cosTheta)))) end
function tmp = code(cosTheta, c) tmp = single(1.0) / ((single(1.0) + c) + (exp((cosTheta * -cosTheta)) * (((single(pi) ^ single(-0.5)) * (single(1.0) + (cosTheta * (single(-1.0) + (cosTheta * ((cosTheta * single(-0.5)) - single(0.5))))))) / cosTheta))); end
\begin{array}{l}
\\
\frac{1}{\left(1 + c\right) + e^{cosTheta \cdot \left(-cosTheta\right)} \cdot \frac{{\pi}^{-0.5} \cdot \left(1 + cosTheta \cdot \left(-1 + cosTheta \cdot \left(cosTheta \cdot -0.5 - 0.5\right)\right)\right)}{cosTheta}}
\end{array}
Initial program 97.6%
add-cube-cbrt97.6%
cbrt-unprod97.6%
frac-times97.8%
metadata-eval97.8%
add-sqr-sqrt97.8%
inv-pow97.8%
sqrt-pow297.8%
metadata-eval97.8%
Applied egg-rr97.8%
associate-*r/97.7%
inv-pow97.7%
metadata-eval97.7%
pow-prod-up97.7%
cbrt-unprod97.7%
add-cube-cbrt97.7%
associate--l-97.7%
add-log-exp97.6%
add-log-exp97.7%
sum-log97.7%
exp-lft-sqr97.8%
add-log-exp97.7%
Applied egg-rr97.7%
Taylor expanded in cosTheta around 0 96.7%
Final simplification96.7%
(FPCore (cosTheta c)
:precision binary32
(/
1.0
(+
(+ 1.0 c)
(*
(exp (* cosTheta (- cosTheta)))
(/
(* (pow PI -0.5) (+ 1.0 (* cosTheta (+ -1.0 (* cosTheta -0.5)))))
cosTheta)))))
float code(float cosTheta, float c) {
return 1.0f / ((1.0f + c) + (expf((cosTheta * -cosTheta)) * ((powf(((float) M_PI), -0.5f) * (1.0f + (cosTheta * (-1.0f + (cosTheta * -0.5f))))) / cosTheta)));
}
function code(cosTheta, c) return Float32(Float32(1.0) / Float32(Float32(Float32(1.0) + c) + Float32(exp(Float32(cosTheta * Float32(-cosTheta))) * Float32(Float32((Float32(pi) ^ Float32(-0.5)) * Float32(Float32(1.0) + Float32(cosTheta * Float32(Float32(-1.0) + Float32(cosTheta * Float32(-0.5)))))) / cosTheta)))) end
function tmp = code(cosTheta, c) tmp = single(1.0) / ((single(1.0) + c) + (exp((cosTheta * -cosTheta)) * (((single(pi) ^ single(-0.5)) * (single(1.0) + (cosTheta * (single(-1.0) + (cosTheta * single(-0.5)))))) / cosTheta))); end
\begin{array}{l}
\\
\frac{1}{\left(1 + c\right) + e^{cosTheta \cdot \left(-cosTheta\right)} \cdot \frac{{\pi}^{-0.5} \cdot \left(1 + cosTheta \cdot \left(-1 + cosTheta \cdot -0.5\right)\right)}{cosTheta}}
\end{array}
Initial program 97.6%
add-cube-cbrt97.6%
cbrt-unprod97.6%
frac-times97.8%
metadata-eval97.8%
add-sqr-sqrt97.8%
inv-pow97.8%
sqrt-pow297.8%
metadata-eval97.8%
Applied egg-rr97.8%
associate-*r/97.7%
inv-pow97.7%
metadata-eval97.7%
pow-prod-up97.7%
cbrt-unprod97.7%
add-cube-cbrt97.7%
associate--l-97.7%
add-log-exp97.6%
add-log-exp97.7%
sum-log97.7%
exp-lft-sqr97.8%
add-log-exp97.7%
Applied egg-rr97.7%
Taylor expanded in cosTheta around 0 96.3%
Final simplification96.3%
(FPCore (cosTheta c) :precision binary32 (* cosTheta (+ (sqrt PI) (* (* PI cosTheta) (+ (sqrt (/ 1.0 PI)) (- -1.0 c))))))
float code(float cosTheta, float c) {
return cosTheta * (sqrtf(((float) M_PI)) + ((((float) M_PI) * cosTheta) * (sqrtf((1.0f / ((float) M_PI))) + (-1.0f - c))));
}
function code(cosTheta, c) return Float32(cosTheta * Float32(sqrt(Float32(pi)) + Float32(Float32(Float32(pi) * cosTheta) * Float32(sqrt(Float32(Float32(1.0) / Float32(pi))) + Float32(Float32(-1.0) - c))))) end
function tmp = code(cosTheta, c) tmp = cosTheta * (sqrt(single(pi)) + ((single(pi) * cosTheta) * (sqrt((single(1.0) / single(pi))) + (single(-1.0) - c)))); end
\begin{array}{l}
\\
cosTheta \cdot \left(\sqrt{\pi} + \left(\pi \cdot cosTheta\right) \cdot \left(\sqrt{\frac{1}{\pi}} + \left(-1 - c\right)\right)\right)
\end{array}
Initial program 97.6%
add-cube-cbrt97.6%
cbrt-unprod97.6%
frac-times97.8%
metadata-eval97.8%
add-sqr-sqrt97.8%
inv-pow97.8%
sqrt-pow297.8%
metadata-eval97.8%
Applied egg-rr97.8%
Taylor expanded in cosTheta around 0 95.9%
mul-1-neg95.9%
unsub-neg95.9%
associate-*r*95.9%
associate-+r+95.9%
mul-1-neg95.9%
unsub-neg95.9%
Simplified95.9%
Final simplification95.9%
(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 97.6%
associate-+l+97.6%
+-commutative97.6%
*-commutative97.6%
associate-*l*97.6%
fma-define97.6%
Simplified97.6%
Taylor expanded in cosTheta around 0 92.6%
(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 97.6%
associate-+l+97.6%
+-commutative97.6%
*-commutative97.6%
associate-*l*97.6%
fma-define97.6%
Simplified97.6%
Taylor expanded in c around inf 11.1%
Taylor expanded in c around 0 11.1%
mul-1-neg11.1%
unsub-neg11.1%
Simplified11.1%
herbie shell --seed 2024096
(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))))))