
(FPCore (u s)
:precision binary32
(let* ((t_0 (/ 1.0 (+ 1.0 (exp (/ PI s))))))
(*
(- s)
(log
(-
(/ 1.0 (+ (* u (- (/ 1.0 (+ 1.0 (exp (/ (- PI) s)))) t_0)) t_0))
1.0)))))
float code(float u, float s) {
float t_0 = 1.0f / (1.0f + expf((((float) M_PI) / s)));
return -s * logf(((1.0f / ((u * ((1.0f / (1.0f + expf((-((float) M_PI) / s)))) - t_0)) + t_0)) - 1.0f));
}
function code(u, s) t_0 = Float32(Float32(1.0) / Float32(Float32(1.0) + exp(Float32(Float32(pi) / s)))) return Float32(Float32(-s) * log(Float32(Float32(Float32(1.0) / Float32(Float32(u * Float32(Float32(Float32(1.0) / Float32(Float32(1.0) + exp(Float32(Float32(-Float32(pi)) / s)))) - t_0)) + t_0)) - Float32(1.0)))) end
function tmp = code(u, s) t_0 = single(1.0) / (single(1.0) + exp((single(pi) / s))); tmp = -s * log(((single(1.0) / ((u * ((single(1.0) / (single(1.0) + exp((-single(pi) / s)))) - t_0)) + t_0)) - single(1.0))); end
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \frac{1}{1 + e^{\frac{\pi}{s}}}\\
\left(-s\right) \cdot \log \left(\frac{1}{u \cdot \left(\frac{1}{1 + e^{\frac{-\pi}{s}}} - t\_0\right) + t\_0} - 1\right)
\end{array}
\end{array}
Sampling outcomes in binary32 precision:
Herbie found 13 alternatives:
| Alternative | Accuracy | Speedup |
|---|
(FPCore (u s)
:precision binary32
(let* ((t_0 (/ 1.0 (+ 1.0 (exp (/ PI s))))))
(*
(- s)
(log
(-
(/ 1.0 (+ (* u (- (/ 1.0 (+ 1.0 (exp (/ (- PI) s)))) t_0)) t_0))
1.0)))))
float code(float u, float s) {
float t_0 = 1.0f / (1.0f + expf((((float) M_PI) / s)));
return -s * logf(((1.0f / ((u * ((1.0f / (1.0f + expf((-((float) M_PI) / s)))) - t_0)) + t_0)) - 1.0f));
}
function code(u, s) t_0 = Float32(Float32(1.0) / Float32(Float32(1.0) + exp(Float32(Float32(pi) / s)))) return Float32(Float32(-s) * log(Float32(Float32(Float32(1.0) / Float32(Float32(u * Float32(Float32(Float32(1.0) / Float32(Float32(1.0) + exp(Float32(Float32(-Float32(pi)) / s)))) - t_0)) + t_0)) - Float32(1.0)))) end
function tmp = code(u, s) t_0 = single(1.0) / (single(1.0) + exp((single(pi) / s))); tmp = -s * log(((single(1.0) / ((u * ((single(1.0) / (single(1.0) + exp((-single(pi) / s)))) - t_0)) + t_0)) - single(1.0))); end
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \frac{1}{1 + e^{\frac{\pi}{s}}}\\
\left(-s\right) \cdot \log \left(\frac{1}{u \cdot \left(\frac{1}{1 + e^{\frac{-\pi}{s}}} - t\_0\right) + t\_0} - 1\right)
\end{array}
\end{array}
(FPCore (u s)
:precision binary32
(*
(- s)
(log
(+
(/
1.0
(+
(/ u (+ 1.0 (exp (/ (- PI) s))))
(/ (- 1.0 u) (+ 1.0 (pow E (* PI (/ 1.0 s)))))))
-1.0))))
float code(float u, float s) {
return -s * logf(((1.0f / ((u / (1.0f + expf((-((float) M_PI) / s)))) + ((1.0f - u) / (1.0f + powf(((float) M_E), (((float) M_PI) * (1.0f / s))))))) + -1.0f));
}
function code(u, s) return Float32(Float32(-s) * log(Float32(Float32(Float32(1.0) / Float32(Float32(u / Float32(Float32(1.0) + exp(Float32(Float32(-Float32(pi)) / s)))) + Float32(Float32(Float32(1.0) - u) / Float32(Float32(1.0) + (Float32(exp(1)) ^ Float32(Float32(pi) * Float32(Float32(1.0) / s))))))) + Float32(-1.0)))) end
function tmp = code(u, s) tmp = -s * log(((single(1.0) / ((u / (single(1.0) + exp((-single(pi) / s)))) + ((single(1.0) - u) / (single(1.0) + (single(2.71828182845904523536) ^ (single(pi) * (single(1.0) / s))))))) + single(-1.0))); end
\begin{array}{l}
\\
\left(-s\right) \cdot \log \left(\frac{1}{\frac{u}{1 + e^{\frac{-\pi}{s}}} + \frac{1 - u}{1 + {e}^{\left(\pi \cdot \frac{1}{s}\right)}}} + -1\right)
\end{array}
Initial program 99.0%
Simplified99.0%
*-un-lft-identity99.0%
exp-prod99.0%
Applied egg-rr99.0%
clear-num99.0%
associate-/r/99.1%
Applied egg-rr99.1%
Final simplification99.1%
(FPCore (u s)
:precision binary32
(*
s
(-
(log
(+
-1.0
(/
1.0
(+
(/ u (+ 1.0 (exp (/ (- PI) s))))
(/ (- 1.0 u) (+ 1.0 (pow E (/ PI s)))))))))))
float code(float u, float s) {
return s * -logf((-1.0f + (1.0f / ((u / (1.0f + expf((-((float) M_PI) / s)))) + ((1.0f - u) / (1.0f + powf(((float) M_E), (((float) M_PI) / s))))))));
}
function code(u, s) return Float32(s * Float32(-log(Float32(Float32(-1.0) + Float32(Float32(1.0) / Float32(Float32(u / Float32(Float32(1.0) + exp(Float32(Float32(-Float32(pi)) / s)))) + Float32(Float32(Float32(1.0) - u) / Float32(Float32(1.0) + (Float32(exp(1)) ^ Float32(Float32(pi) / s)))))))))) end
function tmp = code(u, s) tmp = s * -log((single(-1.0) + (single(1.0) / ((u / (single(1.0) + exp((-single(pi) / s)))) + ((single(1.0) - u) / (single(1.0) + (single(2.71828182845904523536) ^ (single(pi) / s)))))))); end
\begin{array}{l}
\\
s \cdot \left(-\log \left(-1 + \frac{1}{\frac{u}{1 + e^{\frac{-\pi}{s}}} + \frac{1 - u}{1 + {e}^{\left(\frac{\pi}{s}\right)}}}\right)\right)
\end{array}
Initial program 99.0%
Simplified99.0%
*-un-lft-identity99.0%
exp-prod99.0%
Applied egg-rr99.0%
Final simplification99.0%
(FPCore (u s)
:precision binary32
(*
s
(-
(log
(+
-1.0
(/
1.0
(+
(/ u (+ 1.0 (exp (/ (- PI) s))))
(/ (- 1.0 u) (+ 1.0 (exp (/ PI s)))))))))))
float code(float u, float s) {
return s * -logf((-1.0f + (1.0f / ((u / (1.0f + expf((-((float) M_PI) / s)))) + ((1.0f - u) / (1.0f + expf((((float) M_PI) / s))))))));
}
function code(u, s) return Float32(s * Float32(-log(Float32(Float32(-1.0) + Float32(Float32(1.0) / Float32(Float32(u / Float32(Float32(1.0) + exp(Float32(Float32(-Float32(pi)) / s)))) + Float32(Float32(Float32(1.0) - u) / Float32(Float32(1.0) + exp(Float32(Float32(pi) / s)))))))))) end
function tmp = code(u, s) tmp = s * -log((single(-1.0) + (single(1.0) / ((u / (single(1.0) + exp((-single(pi) / s)))) + ((single(1.0) - u) / (single(1.0) + exp((single(pi) / s)))))))); end
\begin{array}{l}
\\
s \cdot \left(-\log \left(-1 + \frac{1}{\frac{u}{1 + e^{\frac{-\pi}{s}}} + \frac{1 - u}{1 + e^{\frac{\pi}{s}}}}\right)\right)
\end{array}
Initial program 99.0%
Simplified99.0%
Final simplification99.0%
(FPCore (u s)
:precision binary32
(*
(- s)
(log
(+
-1.0
(/
1.0
(+
(/ u (+ 1.0 (exp (/ (- PI) s))))
(/ (- 1.0 u) (+ 1.0 (+ 1.0 (/ PI s))))))))))
float code(float u, float s) {
return -s * logf((-1.0f + (1.0f / ((u / (1.0f + expf((-((float) M_PI) / s)))) + ((1.0f - u) / (1.0f + (1.0f + (((float) M_PI) / s))))))));
}
function code(u, s) return Float32(Float32(-s) * log(Float32(Float32(-1.0) + Float32(Float32(1.0) / Float32(Float32(u / Float32(Float32(1.0) + exp(Float32(Float32(-Float32(pi)) / s)))) + Float32(Float32(Float32(1.0) - u) / Float32(Float32(1.0) + Float32(Float32(1.0) + Float32(Float32(pi) / s))))))))) end
function tmp = code(u, s) tmp = -s * log((single(-1.0) + (single(1.0) / ((u / (single(1.0) + exp((-single(pi) / s)))) + ((single(1.0) - u) / (single(1.0) + (single(1.0) + (single(pi) / s)))))))); end
\begin{array}{l}
\\
\left(-s\right) \cdot \log \left(-1 + \frac{1}{\frac{u}{1 + e^{\frac{-\pi}{s}}} + \frac{1 - u}{1 + \left(1 + \frac{\pi}{s}\right)}}\right)
\end{array}
Initial program 99.0%
Simplified99.0%
Taylor expanded in s around inf 88.2%
+-commutative88.2%
Simplified88.2%
Final simplification88.2%
(FPCore (u s) :precision binary32 (* (- s) (log (+ -1.0 (/ 1.0 (* u (+ (/ 1.0 (+ 1.0 (exp (/ (- PI) s)))) -0.5)))))))
float code(float u, float s) {
return -s * logf((-1.0f + (1.0f / (u * ((1.0f / (1.0f + expf((-((float) M_PI) / s)))) + -0.5f)))));
}
function code(u, s) return Float32(Float32(-s) * log(Float32(Float32(-1.0) + Float32(Float32(1.0) / Float32(u * Float32(Float32(Float32(1.0) / Float32(Float32(1.0) + exp(Float32(Float32(-Float32(pi)) / s)))) + Float32(-0.5))))))) end
function tmp = code(u, s) tmp = -s * log((single(-1.0) + (single(1.0) / (u * ((single(1.0) / (single(1.0) + exp((-single(pi) / s)))) + single(-0.5)))))); end
\begin{array}{l}
\\
\left(-s\right) \cdot \log \left(-1 + \frac{1}{u \cdot \left(\frac{1}{1 + e^{\frac{-\pi}{s}}} + -0.5\right)}\right)
\end{array}
Initial program 99.0%
Simplified99.0%
Taylor expanded in s around inf 8.9%
Taylor expanded in u around inf 37.3%
sub-neg37.3%
sub-neg37.3%
associate-*r/37.3%
mul-1-neg37.3%
metadata-eval37.3%
metadata-eval37.3%
Simplified37.3%
Final simplification37.3%
(FPCore (u s) :precision binary32 (* (- s) (log (/ (/ 1.0 u) (+ (/ 1.0 (+ 1.0 (exp (/ (- PI) s)))) -0.5)))))
float code(float u, float s) {
return -s * logf(((1.0f / u) / ((1.0f / (1.0f + expf((-((float) M_PI) / s)))) + -0.5f)));
}
function code(u, s) return Float32(Float32(-s) * log(Float32(Float32(Float32(1.0) / u) / Float32(Float32(Float32(1.0) / Float32(Float32(1.0) + exp(Float32(Float32(-Float32(pi)) / s)))) + Float32(-0.5))))) end
function tmp = code(u, s) tmp = -s * log(((single(1.0) / u) / ((single(1.0) / (single(1.0) + exp((-single(pi) / s)))) + single(-0.5)))); end
\begin{array}{l}
\\
\left(-s\right) \cdot \log \left(\frac{\frac{1}{u}}{\frac{1}{1 + e^{\frac{-\pi}{s}}} + -0.5}\right)
\end{array}
Initial program 99.0%
Simplified99.0%
Taylor expanded in s around inf 8.9%
Taylor expanded in u around inf 37.3%
sub-neg37.3%
sub-neg37.3%
associate-*r/37.3%
mul-1-neg37.3%
metadata-eval37.3%
metadata-eval37.3%
Simplified37.3%
Taylor expanded in u around 0 37.3%
associate-/r*37.3%
sub-neg37.3%
neg-mul-137.3%
distribute-frac-neg237.3%
metadata-eval37.3%
+-commutative37.3%
distribute-frac-neg237.3%
neg-mul-137.3%
neg-mul-137.3%
distribute-neg-frac37.3%
Simplified37.3%
Final simplification37.3%
(FPCore (u s) :precision binary32 (* s (* u (- (* -4.0 (/ 1.0 (+ -1.0 (+ -1.0 (/ PI s))))) 2.0))))
float code(float u, float s) {
return s * (u * ((-4.0f * (1.0f / (-1.0f + (-1.0f + (((float) M_PI) / s))))) - 2.0f));
}
function code(u, s) return Float32(s * Float32(u * Float32(Float32(Float32(-4.0) * Float32(Float32(1.0) / Float32(Float32(-1.0) + Float32(Float32(-1.0) + Float32(Float32(pi) / s))))) - Float32(2.0)))) end
function tmp = code(u, s) tmp = s * (u * ((single(-4.0) * (single(1.0) / (single(-1.0) + (single(-1.0) + (single(pi) / s))))) - single(2.0))); end
\begin{array}{l}
\\
s \cdot \left(u \cdot \left(-4 \cdot \frac{1}{-1 + \left(-1 + \frac{\pi}{s}\right)} - 2\right)\right)
\end{array}
Initial program 99.0%
Simplified99.0%
Taylor expanded in s around inf 8.9%
Taylor expanded in u around 0 8.7%
*-commutative8.7%
associate-*r*8.7%
*-commutative8.7%
sub-neg8.7%
metadata-eval8.7%
distribute-lft-in8.7%
mul-1-neg8.7%
distribute-neg-frac28.7%
metadata-eval8.7%
Simplified8.7%
Taylor expanded in s around inf 16.4%
mul-1-neg16.4%
unsub-neg16.4%
Simplified16.4%
Final simplification16.4%
(FPCore (u s) :precision binary32 (* -4.0 (* u (+ (* PI -0.5) (* 0.25 (/ 1.0 (/ 1.0 (/ PI u))))))))
float code(float u, float s) {
return -4.0f * (u * ((((float) M_PI) * -0.5f) + (0.25f * (1.0f / (1.0f / (((float) M_PI) / u))))));
}
function code(u, s) return Float32(Float32(-4.0) * Float32(u * Float32(Float32(Float32(pi) * Float32(-0.5)) + Float32(Float32(0.25) * Float32(Float32(1.0) / Float32(Float32(1.0) / Float32(Float32(pi) / u))))))) end
function tmp = code(u, s) tmp = single(-4.0) * (u * ((single(pi) * single(-0.5)) + (single(0.25) * (single(1.0) / (single(1.0) / (single(pi) / u)))))); end
\begin{array}{l}
\\
-4 \cdot \left(u \cdot \left(\pi \cdot -0.5 + 0.25 \cdot \frac{1}{\frac{1}{\frac{\pi}{u}}}\right)\right)
\end{array}
Initial program 99.0%
Simplified99.0%
Taylor expanded in s around -inf 11.4%
associate--r+11.4%
cancel-sign-sub-inv11.4%
cancel-sign-sub-inv11.4%
metadata-eval11.4%
associate-*r*11.4%
distribute-rgt-out11.4%
*-commutative11.4%
metadata-eval11.4%
*-commutative11.4%
associate-*l*11.4%
Simplified11.4%
Taylor expanded in u around inf 11.4%
clear-num11.4%
inv-pow11.4%
Applied egg-rr11.4%
unpow-111.4%
Simplified11.4%
clear-num11.4%
inv-pow11.4%
Applied egg-rr11.4%
unpow-111.4%
Simplified11.4%
Final simplification11.4%
(FPCore (u s) :precision binary32 (* -4.0 (* u (/ (* PI (+ 0.25 (* u -0.5))) u))))
float code(float u, float s) {
return -4.0f * (u * ((((float) M_PI) * (0.25f + (u * -0.5f))) / u));
}
function code(u, s) return Float32(Float32(-4.0) * Float32(u * Float32(Float32(Float32(pi) * Float32(Float32(0.25) + Float32(u * Float32(-0.5)))) / u))) end
function tmp = code(u, s) tmp = single(-4.0) * (u * ((single(pi) * (single(0.25) + (u * single(-0.5)))) / u)); end
\begin{array}{l}
\\
-4 \cdot \left(u \cdot \frac{\pi \cdot \left(0.25 + u \cdot -0.5\right)}{u}\right)
\end{array}
Initial program 99.0%
Simplified99.0%
Taylor expanded in s around -inf 11.4%
associate--r+11.4%
cancel-sign-sub-inv11.4%
cancel-sign-sub-inv11.4%
metadata-eval11.4%
associate-*r*11.4%
distribute-rgt-out11.4%
*-commutative11.4%
metadata-eval11.4%
*-commutative11.4%
associate-*l*11.4%
Simplified11.4%
Taylor expanded in u around inf 11.4%
Taylor expanded in u around 0 11.4%
+-commutative11.4%
associate-*r*11.4%
*-commutative11.4%
distribute-rgt-out11.4%
Simplified11.4%
(FPCore (u s) :precision binary32 (* -4.0 (* u (+ (* PI -0.5) (* 0.25 (/ PI u))))))
float code(float u, float s) {
return -4.0f * (u * ((((float) M_PI) * -0.5f) + (0.25f * (((float) M_PI) / u))));
}
function code(u, s) return Float32(Float32(-4.0) * Float32(u * Float32(Float32(Float32(pi) * Float32(-0.5)) + Float32(Float32(0.25) * Float32(Float32(pi) / u))))) end
function tmp = code(u, s) tmp = single(-4.0) * (u * ((single(pi) * single(-0.5)) + (single(0.25) * (single(pi) / u)))); end
\begin{array}{l}
\\
-4 \cdot \left(u \cdot \left(\pi \cdot -0.5 + 0.25 \cdot \frac{\pi}{u}\right)\right)
\end{array}
Initial program 99.0%
Simplified99.0%
Taylor expanded in s around -inf 11.4%
associate--r+11.4%
cancel-sign-sub-inv11.4%
cancel-sign-sub-inv11.4%
metadata-eval11.4%
associate-*r*11.4%
distribute-rgt-out11.4%
*-commutative11.4%
metadata-eval11.4%
*-commutative11.4%
associate-*l*11.4%
Simplified11.4%
Taylor expanded in u around inf 11.4%
Final simplification11.4%
(FPCore (u s) :precision binary32 (* -4.0 (* PI (+ 0.25 (* u -0.5)))))
float code(float u, float s) {
return -4.0f * (((float) M_PI) * (0.25f + (u * -0.5f)));
}
function code(u, s) return Float32(Float32(-4.0) * Float32(Float32(pi) * Float32(Float32(0.25) + Float32(u * Float32(-0.5))))) end
function tmp = code(u, s) tmp = single(-4.0) * (single(pi) * (single(0.25) + (u * single(-0.5)))); end
\begin{array}{l}
\\
-4 \cdot \left(\pi \cdot \left(0.25 + u \cdot -0.5\right)\right)
\end{array}
Initial program 99.0%
Simplified99.0%
Taylor expanded in s around -inf 11.4%
associate--r+11.4%
cancel-sign-sub-inv11.4%
cancel-sign-sub-inv11.4%
metadata-eval11.4%
associate-*r*11.4%
distribute-rgt-out11.4%
*-commutative11.4%
metadata-eval11.4%
*-commutative11.4%
associate-*l*11.4%
Simplified11.4%
Taylor expanded in u around 0 11.4%
associate-*r*11.4%
distribute-rgt-out11.4%
Simplified11.4%
Final simplification11.4%
(FPCore (u s) :precision binary32 (* -4.0 (* u (* 0.25 (/ PI u)))))
float code(float u, float s) {
return -4.0f * (u * (0.25f * (((float) M_PI) / u)));
}
function code(u, s) return Float32(Float32(-4.0) * Float32(u * Float32(Float32(0.25) * Float32(Float32(pi) / u)))) end
function tmp = code(u, s) tmp = single(-4.0) * (u * (single(0.25) * (single(pi) / u))); end
\begin{array}{l}
\\
-4 \cdot \left(u \cdot \left(0.25 \cdot \frac{\pi}{u}\right)\right)
\end{array}
Initial program 99.0%
Simplified99.0%
Taylor expanded in s around -inf 11.4%
associate--r+11.4%
cancel-sign-sub-inv11.4%
cancel-sign-sub-inv11.4%
metadata-eval11.4%
associate-*r*11.4%
distribute-rgt-out11.4%
*-commutative11.4%
metadata-eval11.4%
*-commutative11.4%
associate-*l*11.4%
Simplified11.4%
Taylor expanded in u around inf 11.4%
Taylor expanded in u around 0 11.3%
(FPCore (u s) :precision binary32 (- PI))
float code(float u, float s) {
return -((float) M_PI);
}
function code(u, s) return Float32(-Float32(pi)) end
function tmp = code(u, s) tmp = -single(pi); end
\begin{array}{l}
\\
-\pi
\end{array}
Initial program 99.0%
Simplified99.0%
Taylor expanded in u around 0 11.3%
neg-mul-111.3%
Simplified11.3%
herbie shell --seed 2024085
(FPCore (u s)
:name "Sample trimmed logistic on [-pi, pi]"
:precision binary32
:pre (and (and (<= 2.328306437e-10 u) (<= u 1.0)) (and (<= 0.0 s) (<= s 1.0651631)))
(* (- s) (log (- (/ 1.0 (+ (* u (- (/ 1.0 (+ 1.0 (exp (/ (- PI) s)))) (/ 1.0 (+ 1.0 (exp (/ PI s)))))) (/ 1.0 (+ 1.0 (exp (/ PI s)))))) 1.0))))