
(FPCore (c_p c_n t s)
:precision binary64
(let* ((t_1 (/ 1.0 (+ 1.0 (exp (- t))))) (t_2 (/ 1.0 (+ 1.0 (exp (- s))))))
(/
(* (pow t_2 c_p) (pow (- 1.0 t_2) c_n))
(* (pow t_1 c_p) (pow (- 1.0 t_1) c_n)))))
double code(double c_p, double c_n, double t, double s) {
double t_1 = 1.0 / (1.0 + exp(-t));
double t_2 = 1.0 / (1.0 + exp(-s));
return (pow(t_2, c_p) * pow((1.0 - t_2), c_n)) / (pow(t_1, c_p) * pow((1.0 - t_1), c_n));
}
real(8) function code(c_p, c_n, t, s)
real(8), intent (in) :: c_p
real(8), intent (in) :: c_n
real(8), intent (in) :: t
real(8), intent (in) :: s
real(8) :: t_1
real(8) :: t_2
t_1 = 1.0d0 / (1.0d0 + exp(-t))
t_2 = 1.0d0 / (1.0d0 + exp(-s))
code = ((t_2 ** c_p) * ((1.0d0 - t_2) ** c_n)) / ((t_1 ** c_p) * ((1.0d0 - t_1) ** c_n))
end function
public static double code(double c_p, double c_n, double t, double s) {
double t_1 = 1.0 / (1.0 + Math.exp(-t));
double t_2 = 1.0 / (1.0 + Math.exp(-s));
return (Math.pow(t_2, c_p) * Math.pow((1.0 - t_2), c_n)) / (Math.pow(t_1, c_p) * Math.pow((1.0 - t_1), c_n));
}
def code(c_p, c_n, t, s): t_1 = 1.0 / (1.0 + math.exp(-t)) t_2 = 1.0 / (1.0 + math.exp(-s)) return (math.pow(t_2, c_p) * math.pow((1.0 - t_2), c_n)) / (math.pow(t_1, c_p) * math.pow((1.0 - t_1), c_n))
function code(c_p, c_n, t, s) t_1 = Float64(1.0 / Float64(1.0 + exp(Float64(-t)))) t_2 = Float64(1.0 / Float64(1.0 + exp(Float64(-s)))) return Float64(Float64((t_2 ^ c_p) * (Float64(1.0 - t_2) ^ c_n)) / Float64((t_1 ^ c_p) * (Float64(1.0 - t_1) ^ c_n))) end
function tmp = code(c_p, c_n, t, s) t_1 = 1.0 / (1.0 + exp(-t)); t_2 = 1.0 / (1.0 + exp(-s)); tmp = ((t_2 ^ c_p) * ((1.0 - t_2) ^ c_n)) / ((t_1 ^ c_p) * ((1.0 - t_1) ^ c_n)); end
code[c$95$p_, c$95$n_, t_, s_] := Block[{t$95$1 = N[(1.0 / N[(1.0 + N[Exp[(-t)], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]}, Block[{t$95$2 = N[(1.0 / N[(1.0 + N[Exp[(-s)], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]}, N[(N[(N[Power[t$95$2, c$95$p], $MachinePrecision] * N[Power[N[(1.0 - t$95$2), $MachinePrecision], c$95$n], $MachinePrecision]), $MachinePrecision] / N[(N[Power[t$95$1, c$95$p], $MachinePrecision] * N[Power[N[(1.0 - t$95$1), $MachinePrecision], c$95$n], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]]
\begin{array}{l}
\\
\begin{array}{l}
t_1 := \frac{1}{1 + e^{-t}}\\
t_2 := \frac{1}{1 + e^{-s}}\\
\frac{{t\_2}^{c\_p} \cdot {\left(1 - t\_2\right)}^{c\_n}}{{t\_1}^{c\_p} \cdot {\left(1 - t\_1\right)}^{c\_n}}
\end{array}
\end{array}
Sampling outcomes in binary64 precision:
Herbie found 5 alternatives:
| Alternative | Accuracy | Speedup |
|---|
(FPCore (c_p c_n t s)
:precision binary64
(let* ((t_1 (/ 1.0 (+ 1.0 (exp (- t))))) (t_2 (/ 1.0 (+ 1.0 (exp (- s))))))
(/
(* (pow t_2 c_p) (pow (- 1.0 t_2) c_n))
(* (pow t_1 c_p) (pow (- 1.0 t_1) c_n)))))
double code(double c_p, double c_n, double t, double s) {
double t_1 = 1.0 / (1.0 + exp(-t));
double t_2 = 1.0 / (1.0 + exp(-s));
return (pow(t_2, c_p) * pow((1.0 - t_2), c_n)) / (pow(t_1, c_p) * pow((1.0 - t_1), c_n));
}
real(8) function code(c_p, c_n, t, s)
real(8), intent (in) :: c_p
real(8), intent (in) :: c_n
real(8), intent (in) :: t
real(8), intent (in) :: s
real(8) :: t_1
real(8) :: t_2
t_1 = 1.0d0 / (1.0d0 + exp(-t))
t_2 = 1.0d0 / (1.0d0 + exp(-s))
code = ((t_2 ** c_p) * ((1.0d0 - t_2) ** c_n)) / ((t_1 ** c_p) * ((1.0d0 - t_1) ** c_n))
end function
public static double code(double c_p, double c_n, double t, double s) {
double t_1 = 1.0 / (1.0 + Math.exp(-t));
double t_2 = 1.0 / (1.0 + Math.exp(-s));
return (Math.pow(t_2, c_p) * Math.pow((1.0 - t_2), c_n)) / (Math.pow(t_1, c_p) * Math.pow((1.0 - t_1), c_n));
}
def code(c_p, c_n, t, s): t_1 = 1.0 / (1.0 + math.exp(-t)) t_2 = 1.0 / (1.0 + math.exp(-s)) return (math.pow(t_2, c_p) * math.pow((1.0 - t_2), c_n)) / (math.pow(t_1, c_p) * math.pow((1.0 - t_1), c_n))
function code(c_p, c_n, t, s) t_1 = Float64(1.0 / Float64(1.0 + exp(Float64(-t)))) t_2 = Float64(1.0 / Float64(1.0 + exp(Float64(-s)))) return Float64(Float64((t_2 ^ c_p) * (Float64(1.0 - t_2) ^ c_n)) / Float64((t_1 ^ c_p) * (Float64(1.0 - t_1) ^ c_n))) end
function tmp = code(c_p, c_n, t, s) t_1 = 1.0 / (1.0 + exp(-t)); t_2 = 1.0 / (1.0 + exp(-s)); tmp = ((t_2 ^ c_p) * ((1.0 - t_2) ^ c_n)) / ((t_1 ^ c_p) * ((1.0 - t_1) ^ c_n)); end
code[c$95$p_, c$95$n_, t_, s_] := Block[{t$95$1 = N[(1.0 / N[(1.0 + N[Exp[(-t)], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]}, Block[{t$95$2 = N[(1.0 / N[(1.0 + N[Exp[(-s)], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]}, N[(N[(N[Power[t$95$2, c$95$p], $MachinePrecision] * N[Power[N[(1.0 - t$95$2), $MachinePrecision], c$95$n], $MachinePrecision]), $MachinePrecision] / N[(N[Power[t$95$1, c$95$p], $MachinePrecision] * N[Power[N[(1.0 - t$95$1), $MachinePrecision], c$95$n], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]]
\begin{array}{l}
\\
\begin{array}{l}
t_1 := \frac{1}{1 + e^{-t}}\\
t_2 := \frac{1}{1 + e^{-s}}\\
\frac{{t\_2}^{c\_p} \cdot {\left(1 - t\_2\right)}^{c\_n}}{{t\_1}^{c\_p} \cdot {\left(1 - t\_1\right)}^{c\_n}}
\end{array}
\end{array}
(FPCore (c_p c_n t s)
:precision binary64
(if (<= (- s) 10000000.0)
(+ 1.0 (* c_n (* t (+ 0.5 (* t 0.125)))))
(/
(pow (/ 1.0 (+ 1.0 (exp (- s)))) c_p)
(+ (* 0.5 (* t c_p)) (pow 0.5 c_p)))))
double code(double c_p, double c_n, double t, double s) {
double tmp;
if (-s <= 10000000.0) {
tmp = 1.0 + (c_n * (t * (0.5 + (t * 0.125))));
} else {
tmp = pow((1.0 / (1.0 + exp(-s))), c_p) / ((0.5 * (t * c_p)) + pow(0.5, c_p));
}
return tmp;
}
real(8) function code(c_p, c_n, t, s)
real(8), intent (in) :: c_p
real(8), intent (in) :: c_n
real(8), intent (in) :: t
real(8), intent (in) :: s
real(8) :: tmp
if (-s <= 10000000.0d0) then
tmp = 1.0d0 + (c_n * (t * (0.5d0 + (t * 0.125d0))))
else
tmp = ((1.0d0 / (1.0d0 + exp(-s))) ** c_p) / ((0.5d0 * (t * c_p)) + (0.5d0 ** c_p))
end if
code = tmp
end function
public static double code(double c_p, double c_n, double t, double s) {
double tmp;
if (-s <= 10000000.0) {
tmp = 1.0 + (c_n * (t * (0.5 + (t * 0.125))));
} else {
tmp = Math.pow((1.0 / (1.0 + Math.exp(-s))), c_p) / ((0.5 * (t * c_p)) + Math.pow(0.5, c_p));
}
return tmp;
}
def code(c_p, c_n, t, s): tmp = 0 if -s <= 10000000.0: tmp = 1.0 + (c_n * (t * (0.5 + (t * 0.125)))) else: tmp = math.pow((1.0 / (1.0 + math.exp(-s))), c_p) / ((0.5 * (t * c_p)) + math.pow(0.5, c_p)) return tmp
function code(c_p, c_n, t, s) tmp = 0.0 if (Float64(-s) <= 10000000.0) tmp = Float64(1.0 + Float64(c_n * Float64(t * Float64(0.5 + Float64(t * 0.125))))); else tmp = Float64((Float64(1.0 / Float64(1.0 + exp(Float64(-s)))) ^ c_p) / Float64(Float64(0.5 * Float64(t * c_p)) + (0.5 ^ c_p))); end return tmp end
function tmp_2 = code(c_p, c_n, t, s) tmp = 0.0; if (-s <= 10000000.0) tmp = 1.0 + (c_n * (t * (0.5 + (t * 0.125)))); else tmp = ((1.0 / (1.0 + exp(-s))) ^ c_p) / ((0.5 * (t * c_p)) + (0.5 ^ c_p)); end tmp_2 = tmp; end
code[c$95$p_, c$95$n_, t_, s_] := If[LessEqual[(-s), 10000000.0], N[(1.0 + N[(c$95$n * N[(t * N[(0.5 + N[(t * 0.125), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(N[Power[N[(1.0 / N[(1.0 + N[Exp[(-s)], $MachinePrecision]), $MachinePrecision]), $MachinePrecision], c$95$p], $MachinePrecision] / N[(N[(0.5 * N[(t * c$95$p), $MachinePrecision]), $MachinePrecision] + N[Power[0.5, c$95$p], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;-s \leq 10000000:\\
\;\;\;\;1 + c\_n \cdot \left(t \cdot \left(0.5 + t \cdot 0.125\right)\right)\\
\mathbf{else}:\\
\;\;\;\;\frac{{\left(\frac{1}{1 + e^{-s}}\right)}^{c\_p}}{0.5 \cdot \left(t \cdot c\_p\right) + {0.5}^{c\_p}}\\
\end{array}
\end{array}
if (neg.f64 s) < 1e7Initial program 94.0%
associate-/l/94.0%
Simplified94.0%
Taylor expanded in c_p around 0 96.8%
Taylor expanded in s around 0 97.2%
Taylor expanded in t around 0 97.9%
Taylor expanded in c_n around 0 97.9%
*-commutative97.9%
Simplified97.9%
if 1e7 < (neg.f64 s) Initial program 50.0%
associate-/l/50.0%
Simplified50.0%
Taylor expanded in c_n around 0 50.0%
Taylor expanded in t around 0 62.5%
Taylor expanded in c_p around 0 100.0%
Final simplification98.0%
(FPCore (c_p c_n t s) :precision binary64 (/ (pow (/ 1.0 (+ 2.0 (* s (+ (* s 0.5) -1.0)))) c_p) (pow 0.5 c_p)))
double code(double c_p, double c_n, double t, double s) {
return pow((1.0 / (2.0 + (s * ((s * 0.5) + -1.0)))), c_p) / pow(0.5, c_p);
}
real(8) function code(c_p, c_n, t, s)
real(8), intent (in) :: c_p
real(8), intent (in) :: c_n
real(8), intent (in) :: t
real(8), intent (in) :: s
code = ((1.0d0 / (2.0d0 + (s * ((s * 0.5d0) + (-1.0d0))))) ** c_p) / (0.5d0 ** c_p)
end function
public static double code(double c_p, double c_n, double t, double s) {
return Math.pow((1.0 / (2.0 + (s * ((s * 0.5) + -1.0)))), c_p) / Math.pow(0.5, c_p);
}
def code(c_p, c_n, t, s): return math.pow((1.0 / (2.0 + (s * ((s * 0.5) + -1.0)))), c_p) / math.pow(0.5, c_p)
function code(c_p, c_n, t, s) return Float64((Float64(1.0 / Float64(2.0 + Float64(s * Float64(Float64(s * 0.5) + -1.0)))) ^ c_p) / (0.5 ^ c_p)) end
function tmp = code(c_p, c_n, t, s) tmp = ((1.0 / (2.0 + (s * ((s * 0.5) + -1.0)))) ^ c_p) / (0.5 ^ c_p); end
code[c$95$p_, c$95$n_, t_, s_] := N[(N[Power[N[(1.0 / N[(2.0 + N[(s * N[(N[(s * 0.5), $MachinePrecision] + -1.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], c$95$p], $MachinePrecision] / N[Power[0.5, c$95$p], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{{\left(\frac{1}{2 + s \cdot \left(s \cdot 0.5 + -1\right)}\right)}^{c\_p}}{{0.5}^{c\_p}}
\end{array}
Initial program 92.6%
associate-/l/92.6%
Simplified92.6%
Taylor expanded in c_n around 0 94.7%
Taylor expanded in s around 0 95.0%
Taylor expanded in t around 0 95.4%
Final simplification95.4%
(FPCore (c_p c_n t s) :precision binary64 (+ 1.0 (* c_n (* t (+ 0.5 (* t 0.125))))))
double code(double c_p, double c_n, double t, double s) {
return 1.0 + (c_n * (t * (0.5 + (t * 0.125))));
}
real(8) function code(c_p, c_n, t, s)
real(8), intent (in) :: c_p
real(8), intent (in) :: c_n
real(8), intent (in) :: t
real(8), intent (in) :: s
code = 1.0d0 + (c_n * (t * (0.5d0 + (t * 0.125d0))))
end function
public static double code(double c_p, double c_n, double t, double s) {
return 1.0 + (c_n * (t * (0.5 + (t * 0.125))));
}
def code(c_p, c_n, t, s): return 1.0 + (c_n * (t * (0.5 + (t * 0.125))))
function code(c_p, c_n, t, s) return Float64(1.0 + Float64(c_n * Float64(t * Float64(0.5 + Float64(t * 0.125))))) end
function tmp = code(c_p, c_n, t, s) tmp = 1.0 + (c_n * (t * (0.5 + (t * 0.125)))); end
code[c$95$p_, c$95$n_, t_, s_] := N[(1.0 + N[(c$95$n * N[(t * N[(0.5 + N[(t * 0.125), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
1 + c\_n \cdot \left(t \cdot \left(0.5 + t \cdot 0.125\right)\right)
\end{array}
Initial program 92.6%
associate-/l/92.6%
Simplified92.6%
Taylor expanded in c_p around 0 93.9%
Taylor expanded in s around 0 94.2%
Taylor expanded in t around 0 94.9%
Taylor expanded in c_n around 0 94.9%
*-commutative94.9%
Simplified94.9%
(FPCore (c_p c_n t s) :precision binary64 (+ 1.0 (* 0.5 (* c_n t))))
double code(double c_p, double c_n, double t, double s) {
return 1.0 + (0.5 * (c_n * t));
}
real(8) function code(c_p, c_n, t, s)
real(8), intent (in) :: c_p
real(8), intent (in) :: c_n
real(8), intent (in) :: t
real(8), intent (in) :: s
code = 1.0d0 + (0.5d0 * (c_n * t))
end function
public static double code(double c_p, double c_n, double t, double s) {
return 1.0 + (0.5 * (c_n * t));
}
def code(c_p, c_n, t, s): return 1.0 + (0.5 * (c_n * t))
function code(c_p, c_n, t, s) return Float64(1.0 + Float64(0.5 * Float64(c_n * t))) end
function tmp = code(c_p, c_n, t, s) tmp = 1.0 + (0.5 * (c_n * t)); end
code[c$95$p_, c$95$n_, t_, s_] := N[(1.0 + N[(0.5 * N[(c$95$n * t), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
1 + 0.5 \cdot \left(c\_n \cdot t\right)
\end{array}
Initial program 92.6%
associate-/l/92.6%
Simplified92.6%
Taylor expanded in c_p around 0 93.9%
Taylor expanded in s around 0 94.2%
Taylor expanded in t around 0 94.9%
*-commutative94.9%
Simplified94.9%
Final simplification94.9%
(FPCore (c_p c_n t s) :precision binary64 1.0)
double code(double c_p, double c_n, double t, double s) {
return 1.0;
}
real(8) function code(c_p, c_n, t, s)
real(8), intent (in) :: c_p
real(8), intent (in) :: c_n
real(8), intent (in) :: t
real(8), intent (in) :: s
code = 1.0d0
end function
public static double code(double c_p, double c_n, double t, double s) {
return 1.0;
}
def code(c_p, c_n, t, s): return 1.0
function code(c_p, c_n, t, s) return 1.0 end
function tmp = code(c_p, c_n, t, s) tmp = 1.0; end
code[c$95$p_, c$95$n_, t_, s_] := 1.0
\begin{array}{l}
\\
1
\end{array}
Initial program 92.6%
associate-/l/92.6%
Simplified92.6%
Taylor expanded in c_n around 0 94.7%
Taylor expanded in c_p around 0 94.8%
(FPCore (c_p c_n t s) :precision binary64 (* (pow (/ (+ 1.0 (exp (- t))) (+ 1.0 (exp (- s)))) c_p) (pow (/ (+ 1.0 (exp t)) (+ 1.0 (exp s))) c_n)))
double code(double c_p, double c_n, double t, double s) {
return pow(((1.0 + exp(-t)) / (1.0 + exp(-s))), c_p) * pow(((1.0 + exp(t)) / (1.0 + exp(s))), c_n);
}
real(8) function code(c_p, c_n, t, s)
real(8), intent (in) :: c_p
real(8), intent (in) :: c_n
real(8), intent (in) :: t
real(8), intent (in) :: s
code = (((1.0d0 + exp(-t)) / (1.0d0 + exp(-s))) ** c_p) * (((1.0d0 + exp(t)) / (1.0d0 + exp(s))) ** c_n)
end function
public static double code(double c_p, double c_n, double t, double s) {
return Math.pow(((1.0 + Math.exp(-t)) / (1.0 + Math.exp(-s))), c_p) * Math.pow(((1.0 + Math.exp(t)) / (1.0 + Math.exp(s))), c_n);
}
def code(c_p, c_n, t, s): return math.pow(((1.0 + math.exp(-t)) / (1.0 + math.exp(-s))), c_p) * math.pow(((1.0 + math.exp(t)) / (1.0 + math.exp(s))), c_n)
function code(c_p, c_n, t, s) return Float64((Float64(Float64(1.0 + exp(Float64(-t))) / Float64(1.0 + exp(Float64(-s)))) ^ c_p) * (Float64(Float64(1.0 + exp(t)) / Float64(1.0 + exp(s))) ^ c_n)) end
function tmp = code(c_p, c_n, t, s) tmp = (((1.0 + exp(-t)) / (1.0 + exp(-s))) ^ c_p) * (((1.0 + exp(t)) / (1.0 + exp(s))) ^ c_n); end
code[c$95$p_, c$95$n_, t_, s_] := N[(N[Power[N[(N[(1.0 + N[Exp[(-t)], $MachinePrecision]), $MachinePrecision] / N[(1.0 + N[Exp[(-s)], $MachinePrecision]), $MachinePrecision]), $MachinePrecision], c$95$p], $MachinePrecision] * N[Power[N[(N[(1.0 + N[Exp[t], $MachinePrecision]), $MachinePrecision] / N[(1.0 + N[Exp[s], $MachinePrecision]), $MachinePrecision]), $MachinePrecision], c$95$n], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
{\left(\frac{1 + e^{-t}}{1 + e^{-s}}\right)}^{c\_p} \cdot {\left(\frac{1 + e^{t}}{1 + e^{s}}\right)}^{c\_n}
\end{array}
herbie shell --seed 2024170
(FPCore (c_p c_n t s)
:name "Harley's example"
:precision binary64
:pre (and (< 0.0 c_p) (< 0.0 c_n))
:alt
(! :herbie-platform default (* (pow (/ (+ 1 (exp (- t))) (+ 1 (exp (- s)))) c_p) (pow (/ (+ 1 (exp t)) (+ 1 (exp s))) c_n)))
(/ (* (pow (/ 1.0 (+ 1.0 (exp (- s)))) c_p) (pow (- 1.0 (/ 1.0 (+ 1.0 (exp (- s))))) c_n)) (* (pow (/ 1.0 (+ 1.0 (exp (- t)))) c_p) (pow (- 1.0 (/ 1.0 (+ 1.0 (exp (- t))))) c_n))))