
(FPCore (x) :precision binary64 (/ 2.0 (+ (exp x) (exp (- x)))))
double code(double x) {
return 2.0 / (exp(x) + exp(-x));
}
real(8) function code(x)
real(8), intent (in) :: x
code = 2.0d0 / (exp(x) + exp(-x))
end function
public static double code(double x) {
return 2.0 / (Math.exp(x) + Math.exp(-x));
}
def code(x): return 2.0 / (math.exp(x) + math.exp(-x))
function code(x) return Float64(2.0 / Float64(exp(x) + exp(Float64(-x)))) end
function tmp = code(x) tmp = 2.0 / (exp(x) + exp(-x)); end
code[x_] := N[(2.0 / N[(N[Exp[x], $MachinePrecision] + N[Exp[(-x)], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{2}{e^{x} + e^{-x}}
\end{array}
Sampling outcomes in binary64 precision:
Herbie found 8 alternatives:
| Alternative | Accuracy | Speedup |
|---|
(FPCore (x) :precision binary64 (/ 2.0 (+ (exp x) (exp (- x)))))
double code(double x) {
return 2.0 / (exp(x) + exp(-x));
}
real(8) function code(x)
real(8), intent (in) :: x
code = 2.0d0 / (exp(x) + exp(-x))
end function
public static double code(double x) {
return 2.0 / (Math.exp(x) + Math.exp(-x));
}
def code(x): return 2.0 / (math.exp(x) + math.exp(-x))
function code(x) return Float64(2.0 / Float64(exp(x) + exp(Float64(-x)))) end
function tmp = code(x) tmp = 2.0 / (exp(x) + exp(-x)); end
code[x_] := N[(2.0 / N[(N[Exp[x], $MachinePrecision] + N[Exp[(-x)], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{2}{e^{x} + e^{-x}}
\end{array}
(FPCore (x) :precision binary64 (pow (cosh x) -1.0))
double code(double x) {
return pow(cosh(x), -1.0);
}
real(8) function code(x)
real(8), intent (in) :: x
code = cosh(x) ** (-1.0d0)
end function
public static double code(double x) {
return Math.pow(Math.cosh(x), -1.0);
}
def code(x): return math.pow(math.cosh(x), -1.0)
function code(x) return cosh(x) ^ -1.0 end
function tmp = code(x) tmp = cosh(x) ^ -1.0; end
code[x_] := N[Power[N[Cosh[x], $MachinePrecision], -1.0], $MachinePrecision]
\begin{array}{l}
\\
{\cosh x}^{-1}
\end{array}
Initial program 100.0%
lift-/.f64N/A
lift-+.f64N/A
lift-exp.f64N/A
lift-exp.f64N/A
lift-neg.f64N/A
cosh-undefN/A
associate-/r*N/A
metadata-evalN/A
lower-/.f64N/A
lower-cosh.f64100.0
Applied rewrites100.0%
Final simplification100.0%
(FPCore (x)
:precision binary64
(let* ((t_0 (* 0.041666666666666664 (* x x))) (t_1 (* (* t_0 x) x)))
(if (<= x 2.5e+77)
(pow (/ (- 1.0 (* t_1 t_1)) (- 1.0 t_1)) -1.0)
(pow (fma t_0 (* x x) 1.0) -1.0))))
double code(double x) {
double t_0 = 0.041666666666666664 * (x * x);
double t_1 = (t_0 * x) * x;
double tmp;
if (x <= 2.5e+77) {
tmp = pow(((1.0 - (t_1 * t_1)) / (1.0 - t_1)), -1.0);
} else {
tmp = pow(fma(t_0, (x * x), 1.0), -1.0);
}
return tmp;
}
function code(x) t_0 = Float64(0.041666666666666664 * Float64(x * x)) t_1 = Float64(Float64(t_0 * x) * x) tmp = 0.0 if (x <= 2.5e+77) tmp = Float64(Float64(1.0 - Float64(t_1 * t_1)) / Float64(1.0 - t_1)) ^ -1.0; else tmp = fma(t_0, Float64(x * x), 1.0) ^ -1.0; end return tmp end
code[x_] := Block[{t$95$0 = N[(0.041666666666666664 * N[(x * x), $MachinePrecision]), $MachinePrecision]}, Block[{t$95$1 = N[(N[(t$95$0 * x), $MachinePrecision] * x), $MachinePrecision]}, If[LessEqual[x, 2.5e+77], N[Power[N[(N[(1.0 - N[(t$95$1 * t$95$1), $MachinePrecision]), $MachinePrecision] / N[(1.0 - t$95$1), $MachinePrecision]), $MachinePrecision], -1.0], $MachinePrecision], N[Power[N[(t$95$0 * N[(x * x), $MachinePrecision] + 1.0), $MachinePrecision], -1.0], $MachinePrecision]]]]
\begin{array}{l}
\\
\begin{array}{l}
t_0 := 0.041666666666666664 \cdot \left(x \cdot x\right)\\
t_1 := \left(t\_0 \cdot x\right) \cdot x\\
\mathbf{if}\;x \leq 2.5 \cdot 10^{+77}:\\
\;\;\;\;{\left(\frac{1 - t\_1 \cdot t\_1}{1 - t\_1}\right)}^{-1}\\
\mathbf{else}:\\
\;\;\;\;{\left(\mathsf{fma}\left(t\_0, x \cdot x, 1\right)\right)}^{-1}\\
\end{array}
\end{array}
if x < 2.50000000000000002e77Initial program 100.0%
lift-/.f64N/A
lift-+.f64N/A
lift-exp.f64N/A
lift-exp.f64N/A
lift-neg.f64N/A
cosh-undefN/A
associate-/r*N/A
metadata-evalN/A
lower-/.f64N/A
lower-cosh.f64100.0
Applied rewrites100.0%
Taylor expanded in x around 0
+-commutativeN/A
*-commutativeN/A
lower-fma.f64N/A
+-commutativeN/A
lower-fma.f64N/A
unpow2N/A
lower-*.f64N/A
unpow2N/A
lower-*.f6483.8
Applied rewrites83.8%
Taylor expanded in x around inf
Applied rewrites83.6%
Applied rewrites66.4%
if 2.50000000000000002e77 < x Initial program 100.0%
lift-/.f64N/A
lift-+.f64N/A
lift-exp.f64N/A
lift-exp.f64N/A
lift-neg.f64N/A
cosh-undefN/A
associate-/r*N/A
metadata-evalN/A
lower-/.f64N/A
lower-cosh.f64100.0
Applied rewrites100.0%
Taylor expanded in x around 0
+-commutativeN/A
*-commutativeN/A
lower-fma.f64N/A
+-commutativeN/A
lower-fma.f64N/A
unpow2N/A
lower-*.f64N/A
unpow2N/A
lower-*.f64100.0
Applied rewrites100.0%
Taylor expanded in x around inf
Applied rewrites100.0%
Final simplification72.3%
(FPCore (x)
:precision binary64
(pow
(fma
(*
(fma (fma (* x x) 0.001388888888888889 0.041666666666666664) (* x x) 0.5)
x)
x
1.0)
-1.0))
double code(double x) {
return pow(fma((fma(fma((x * x), 0.001388888888888889, 0.041666666666666664), (x * x), 0.5) * x), x, 1.0), -1.0);
}
function code(x) return fma(Float64(fma(fma(Float64(x * x), 0.001388888888888889, 0.041666666666666664), Float64(x * x), 0.5) * x), x, 1.0) ^ -1.0 end
code[x_] := N[Power[N[(N[(N[(N[(N[(x * x), $MachinePrecision] * 0.001388888888888889 + 0.041666666666666664), $MachinePrecision] * N[(x * x), $MachinePrecision] + 0.5), $MachinePrecision] * x), $MachinePrecision] * x + 1.0), $MachinePrecision], -1.0], $MachinePrecision]
\begin{array}{l}
\\
{\left(\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(x \cdot x, 0.001388888888888889, 0.041666666666666664\right), x \cdot x, 0.5\right) \cdot x, x, 1\right)\right)}^{-1}
\end{array}
Initial program 100.0%
lift-/.f64N/A
lift-+.f64N/A
lift-exp.f64N/A
lift-exp.f64N/A
lift-neg.f64N/A
cosh-undefN/A
associate-/r*N/A
metadata-evalN/A
lower-/.f64N/A
lower-cosh.f64100.0
Applied rewrites100.0%
Taylor expanded in x around 0
+-commutativeN/A
*-commutativeN/A
lower-fma.f64N/A
+-commutativeN/A
*-commutativeN/A
lower-fma.f64N/A
+-commutativeN/A
lower-fma.f64N/A
unpow2N/A
lower-*.f64N/A
unpow2N/A
lower-*.f64N/A
unpow2N/A
lower-*.f6491.2
Applied rewrites91.2%
Applied rewrites91.2%
Final simplification91.2%
(FPCore (x) :precision binary64 (pow (fma (* (fma (* 0.001388888888888889 (* x x)) (* x x) 0.5) x) x 1.0) -1.0))
double code(double x) {
return pow(fma((fma((0.001388888888888889 * (x * x)), (x * x), 0.5) * x), x, 1.0), -1.0);
}
function code(x) return fma(Float64(fma(Float64(0.001388888888888889 * Float64(x * x)), Float64(x * x), 0.5) * x), x, 1.0) ^ -1.0 end
code[x_] := N[Power[N[(N[(N[(N[(0.001388888888888889 * N[(x * x), $MachinePrecision]), $MachinePrecision] * N[(x * x), $MachinePrecision] + 0.5), $MachinePrecision] * x), $MachinePrecision] * x + 1.0), $MachinePrecision], -1.0], $MachinePrecision]
\begin{array}{l}
\\
{\left(\mathsf{fma}\left(\mathsf{fma}\left(0.001388888888888889 \cdot \left(x \cdot x\right), x \cdot x, 0.5\right) \cdot x, x, 1\right)\right)}^{-1}
\end{array}
Initial program 100.0%
lift-/.f64N/A
lift-+.f64N/A
lift-exp.f64N/A
lift-exp.f64N/A
lift-neg.f64N/A
cosh-undefN/A
associate-/r*N/A
metadata-evalN/A
lower-/.f64N/A
lower-cosh.f64100.0
Applied rewrites100.0%
Taylor expanded in x around 0
+-commutativeN/A
*-commutativeN/A
lower-fma.f64N/A
+-commutativeN/A
*-commutativeN/A
lower-fma.f64N/A
+-commutativeN/A
lower-fma.f64N/A
unpow2N/A
lower-*.f64N/A
unpow2N/A
lower-*.f64N/A
unpow2N/A
lower-*.f6491.2
Applied rewrites91.2%
Taylor expanded in x around inf
Applied rewrites91.1%
Applied rewrites91.1%
Final simplification91.1%
(FPCore (x) :precision binary64 (pow (fma (* (fma 0.041666666666666664 (* x x) 0.5) x) x 1.0) -1.0))
double code(double x) {
return pow(fma((fma(0.041666666666666664, (x * x), 0.5) * x), x, 1.0), -1.0);
}
function code(x) return fma(Float64(fma(0.041666666666666664, Float64(x * x), 0.5) * x), x, 1.0) ^ -1.0 end
code[x_] := N[Power[N[(N[(N[(0.041666666666666664 * N[(x * x), $MachinePrecision] + 0.5), $MachinePrecision] * x), $MachinePrecision] * x + 1.0), $MachinePrecision], -1.0], $MachinePrecision]
\begin{array}{l}
\\
{\left(\mathsf{fma}\left(\mathsf{fma}\left(0.041666666666666664, x \cdot x, 0.5\right) \cdot x, x, 1\right)\right)}^{-1}
\end{array}
Initial program 100.0%
lift-/.f64N/A
lift-+.f64N/A
lift-exp.f64N/A
lift-exp.f64N/A
lift-neg.f64N/A
cosh-undefN/A
associate-/r*N/A
metadata-evalN/A
lower-/.f64N/A
lower-cosh.f64100.0
Applied rewrites100.0%
Taylor expanded in x around 0
+-commutativeN/A
*-commutativeN/A
lower-fma.f64N/A
+-commutativeN/A
lower-fma.f64N/A
unpow2N/A
lower-*.f64N/A
unpow2N/A
lower-*.f6486.7
Applied rewrites86.7%
Applied rewrites86.7%
Final simplification86.7%
(FPCore (x) :precision binary64 (pow (fma (* 0.041666666666666664 (* x x)) (* x x) 1.0) -1.0))
double code(double x) {
return pow(fma((0.041666666666666664 * (x * x)), (x * x), 1.0), -1.0);
}
function code(x) return fma(Float64(0.041666666666666664 * Float64(x * x)), Float64(x * x), 1.0) ^ -1.0 end
code[x_] := N[Power[N[(N[(0.041666666666666664 * N[(x * x), $MachinePrecision]), $MachinePrecision] * N[(x * x), $MachinePrecision] + 1.0), $MachinePrecision], -1.0], $MachinePrecision]
\begin{array}{l}
\\
{\left(\mathsf{fma}\left(0.041666666666666664 \cdot \left(x \cdot x\right), x \cdot x, 1\right)\right)}^{-1}
\end{array}
Initial program 100.0%
lift-/.f64N/A
lift-+.f64N/A
lift-exp.f64N/A
lift-exp.f64N/A
lift-neg.f64N/A
cosh-undefN/A
associate-/r*N/A
metadata-evalN/A
lower-/.f64N/A
lower-cosh.f64100.0
Applied rewrites100.0%
Taylor expanded in x around 0
+-commutativeN/A
*-commutativeN/A
lower-fma.f64N/A
+-commutativeN/A
lower-fma.f64N/A
unpow2N/A
lower-*.f64N/A
unpow2N/A
lower-*.f6486.7
Applied rewrites86.7%
Taylor expanded in x around inf
Applied rewrites86.5%
Final simplification86.5%
(FPCore (x) :precision binary64 (/ 2.0 (fma x x 2.0)))
double code(double x) {
return 2.0 / fma(x, x, 2.0);
}
function code(x) return Float64(2.0 / fma(x, x, 2.0)) end
code[x_] := N[(2.0 / N[(x * x + 2.0), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{2}{\mathsf{fma}\left(x, x, 2\right)}
\end{array}
Initial program 100.0%
Taylor expanded in x around 0
+-commutativeN/A
unpow2N/A
lower-fma.f6473.3
Applied rewrites73.3%
(FPCore (x) :precision binary64 1.0)
double code(double x) {
return 1.0;
}
real(8) function code(x)
real(8), intent (in) :: x
code = 1.0d0
end function
public static double code(double x) {
return 1.0;
}
def code(x): return 1.0
function code(x) return 1.0 end
function tmp = code(x) tmp = 1.0; end
code[x_] := 1.0
\begin{array}{l}
\\
1
\end{array}
Initial program 100.0%
Taylor expanded in x around 0
Applied rewrites48.3%
herbie shell --seed 2024326
(FPCore (x)
:name "Hyperbolic secant"
:precision binary64
(/ 2.0 (+ (exp x) (exp (- x)))))