Jmat.Real.dawson

Percentage Accurate: 54.5% → 100.0%
Time: 6.2s
Alternatives: 5
Speedup: 34.2×

Specification

?
\[\begin{array}{l} \\ \begin{array}{l} t_0 := \left(x \cdot x\right) \cdot \left(x \cdot x\right)\\ t_1 := t_0 \cdot \left(x \cdot x\right)\\ t_2 := t_1 \cdot \left(x \cdot x\right)\\ t_3 := t_2 \cdot \left(x \cdot x\right)\\ \frac{\left(\left(\left(\left(1 + 0.1049934947 \cdot \left(x \cdot x\right)\right) + 0.0424060604 \cdot t_0\right) + 0.0072644182 \cdot t_1\right) + 0.0005064034 \cdot t_2\right) + 0.0001789971 \cdot t_3}{\left(\left(\left(\left(\left(1 + 0.7715471019 \cdot \left(x \cdot x\right)\right) + 0.2909738639 \cdot t_0\right) + 0.0694555761 \cdot t_1\right) + 0.0140005442 \cdot t_2\right) + 0.0008327945 \cdot t_3\right) + \left(2 \cdot 0.0001789971\right) \cdot \left(t_3 \cdot \left(x \cdot x\right)\right)} \cdot x \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (let* ((t_0 (* (* x x) (* x x)))
        (t_1 (* t_0 (* x x)))
        (t_2 (* t_1 (* x x)))
        (t_3 (* t_2 (* x x))))
   (*
    (/
     (+
      (+
       (+
        (+ (+ 1.0 (* 0.1049934947 (* x x))) (* 0.0424060604 t_0))
        (* 0.0072644182 t_1))
       (* 0.0005064034 t_2))
      (* 0.0001789971 t_3))
     (+
      (+
       (+
        (+
         (+ (+ 1.0 (* 0.7715471019 (* x x))) (* 0.2909738639 t_0))
         (* 0.0694555761 t_1))
        (* 0.0140005442 t_2))
       (* 0.0008327945 t_3))
      (* (* 2.0 0.0001789971) (* t_3 (* x x)))))
    x)))
double code(double x) {
	double t_0 = (x * x) * (x * x);
	double t_1 = t_0 * (x * x);
	double t_2 = t_1 * (x * x);
	double t_3 = t_2 * (x * x);
	return ((((((1.0 + (0.1049934947 * (x * x))) + (0.0424060604 * t_0)) + (0.0072644182 * t_1)) + (0.0005064034 * t_2)) + (0.0001789971 * t_3)) / ((((((1.0 + (0.7715471019 * (x * x))) + (0.2909738639 * t_0)) + (0.0694555761 * t_1)) + (0.0140005442 * t_2)) + (0.0008327945 * t_3)) + ((2.0 * 0.0001789971) * (t_3 * (x * x))))) * x;
}
real(8) function code(x)
    real(8), intent (in) :: x
    real(8) :: t_0
    real(8) :: t_1
    real(8) :: t_2
    real(8) :: t_3
    t_0 = (x * x) * (x * x)
    t_1 = t_0 * (x * x)
    t_2 = t_1 * (x * x)
    t_3 = t_2 * (x * x)
    code = ((((((1.0d0 + (0.1049934947d0 * (x * x))) + (0.0424060604d0 * t_0)) + (0.0072644182d0 * t_1)) + (0.0005064034d0 * t_2)) + (0.0001789971d0 * t_3)) / ((((((1.0d0 + (0.7715471019d0 * (x * x))) + (0.2909738639d0 * t_0)) + (0.0694555761d0 * t_1)) + (0.0140005442d0 * t_2)) + (0.0008327945d0 * t_3)) + ((2.0d0 * 0.0001789971d0) * (t_3 * (x * x))))) * x
end function
public static double code(double x) {
	double t_0 = (x * x) * (x * x);
	double t_1 = t_0 * (x * x);
	double t_2 = t_1 * (x * x);
	double t_3 = t_2 * (x * x);
	return ((((((1.0 + (0.1049934947 * (x * x))) + (0.0424060604 * t_0)) + (0.0072644182 * t_1)) + (0.0005064034 * t_2)) + (0.0001789971 * t_3)) / ((((((1.0 + (0.7715471019 * (x * x))) + (0.2909738639 * t_0)) + (0.0694555761 * t_1)) + (0.0140005442 * t_2)) + (0.0008327945 * t_3)) + ((2.0 * 0.0001789971) * (t_3 * (x * x))))) * x;
}
def code(x):
	t_0 = (x * x) * (x * x)
	t_1 = t_0 * (x * x)
	t_2 = t_1 * (x * x)
	t_3 = t_2 * (x * x)
	return ((((((1.0 + (0.1049934947 * (x * x))) + (0.0424060604 * t_0)) + (0.0072644182 * t_1)) + (0.0005064034 * t_2)) + (0.0001789971 * t_3)) / ((((((1.0 + (0.7715471019 * (x * x))) + (0.2909738639 * t_0)) + (0.0694555761 * t_1)) + (0.0140005442 * t_2)) + (0.0008327945 * t_3)) + ((2.0 * 0.0001789971) * (t_3 * (x * x))))) * x
function code(x)
	t_0 = Float64(Float64(x * x) * Float64(x * x))
	t_1 = Float64(t_0 * Float64(x * x))
	t_2 = Float64(t_1 * Float64(x * x))
	t_3 = Float64(t_2 * Float64(x * x))
	return Float64(Float64(Float64(Float64(Float64(Float64(Float64(1.0 + Float64(0.1049934947 * Float64(x * x))) + Float64(0.0424060604 * t_0)) + Float64(0.0072644182 * t_1)) + Float64(0.0005064034 * t_2)) + Float64(0.0001789971 * t_3)) / Float64(Float64(Float64(Float64(Float64(Float64(1.0 + Float64(0.7715471019 * Float64(x * x))) + Float64(0.2909738639 * t_0)) + Float64(0.0694555761 * t_1)) + Float64(0.0140005442 * t_2)) + Float64(0.0008327945 * t_3)) + Float64(Float64(2.0 * 0.0001789971) * Float64(t_3 * Float64(x * x))))) * x)
end
function tmp = code(x)
	t_0 = (x * x) * (x * x);
	t_1 = t_0 * (x * x);
	t_2 = t_1 * (x * x);
	t_3 = t_2 * (x * x);
	tmp = ((((((1.0 + (0.1049934947 * (x * x))) + (0.0424060604 * t_0)) + (0.0072644182 * t_1)) + (0.0005064034 * t_2)) + (0.0001789971 * t_3)) / ((((((1.0 + (0.7715471019 * (x * x))) + (0.2909738639 * t_0)) + (0.0694555761 * t_1)) + (0.0140005442 * t_2)) + (0.0008327945 * t_3)) + ((2.0 * 0.0001789971) * (t_3 * (x * x))))) * x;
end
code[x_] := Block[{t$95$0 = N[(N[(x * x), $MachinePrecision] * N[(x * x), $MachinePrecision]), $MachinePrecision]}, Block[{t$95$1 = N[(t$95$0 * N[(x * x), $MachinePrecision]), $MachinePrecision]}, Block[{t$95$2 = N[(t$95$1 * N[(x * x), $MachinePrecision]), $MachinePrecision]}, Block[{t$95$3 = N[(t$95$2 * N[(x * x), $MachinePrecision]), $MachinePrecision]}, N[(N[(N[(N[(N[(N[(N[(1.0 + N[(0.1049934947 * N[(x * x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(0.0424060604 * t$95$0), $MachinePrecision]), $MachinePrecision] + N[(0.0072644182 * t$95$1), $MachinePrecision]), $MachinePrecision] + N[(0.0005064034 * t$95$2), $MachinePrecision]), $MachinePrecision] + N[(0.0001789971 * t$95$3), $MachinePrecision]), $MachinePrecision] / N[(N[(N[(N[(N[(N[(1.0 + N[(0.7715471019 * N[(x * x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(0.2909738639 * t$95$0), $MachinePrecision]), $MachinePrecision] + N[(0.0694555761 * t$95$1), $MachinePrecision]), $MachinePrecision] + N[(0.0140005442 * t$95$2), $MachinePrecision]), $MachinePrecision] + N[(0.0008327945 * t$95$3), $MachinePrecision]), $MachinePrecision] + N[(N[(2.0 * 0.0001789971), $MachinePrecision] * N[(t$95$3 * N[(x * x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * x), $MachinePrecision]]]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \left(x \cdot x\right) \cdot \left(x \cdot x\right)\\
t_1 := t_0 \cdot \left(x \cdot x\right)\\
t_2 := t_1 \cdot \left(x \cdot x\right)\\
t_3 := t_2 \cdot \left(x \cdot x\right)\\
\frac{\left(\left(\left(\left(1 + 0.1049934947 \cdot \left(x \cdot x\right)\right) + 0.0424060604 \cdot t_0\right) + 0.0072644182 \cdot t_1\right) + 0.0005064034 \cdot t_2\right) + 0.0001789971 \cdot t_3}{\left(\left(\left(\left(\left(1 + 0.7715471019 \cdot \left(x \cdot x\right)\right) + 0.2909738639 \cdot t_0\right) + 0.0694555761 \cdot t_1\right) + 0.0140005442 \cdot t_2\right) + 0.0008327945 \cdot t_3\right) + \left(2 \cdot 0.0001789971\right) \cdot \left(t_3 \cdot \left(x \cdot x\right)\right)} \cdot x
\end{array}
\end{array}

Sampling outcomes in binary64 precision:

Local Percentage Accuracy vs ?

The average percentage accuracy by input value. Horizontal axis shows value of an input variable; the variable is choosen in the title. Vertical axis is accuracy; higher is better. Red represent the original program, while blue represents Herbie's suggestion. These can be toggled with buttons below the plot. The line is an average while dots represent individual samples.

Accuracy vs Speed?

Herbie found 5 alternatives:

AlternativeAccuracySpeedup
The accuracy (vertical axis) and speed (horizontal axis) of each alternatives. Up and to the right is better. The red square shows the initial program, and each blue circle shows an alternative.The line shows the best available speed-accuracy tradeoffs.

Initial Program: 54.5% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \left(x \cdot x\right) \cdot \left(x \cdot x\right)\\ t_1 := t_0 \cdot \left(x \cdot x\right)\\ t_2 := t_1 \cdot \left(x \cdot x\right)\\ t_3 := t_2 \cdot \left(x \cdot x\right)\\ \frac{\left(\left(\left(\left(1 + 0.1049934947 \cdot \left(x \cdot x\right)\right) + 0.0424060604 \cdot t_0\right) + 0.0072644182 \cdot t_1\right) + 0.0005064034 \cdot t_2\right) + 0.0001789971 \cdot t_3}{\left(\left(\left(\left(\left(1 + 0.7715471019 \cdot \left(x \cdot x\right)\right) + 0.2909738639 \cdot t_0\right) + 0.0694555761 \cdot t_1\right) + 0.0140005442 \cdot t_2\right) + 0.0008327945 \cdot t_3\right) + \left(2 \cdot 0.0001789971\right) \cdot \left(t_3 \cdot \left(x \cdot x\right)\right)} \cdot x \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (let* ((t_0 (* (* x x) (* x x)))
        (t_1 (* t_0 (* x x)))
        (t_2 (* t_1 (* x x)))
        (t_3 (* t_2 (* x x))))
   (*
    (/
     (+
      (+
       (+
        (+ (+ 1.0 (* 0.1049934947 (* x x))) (* 0.0424060604 t_0))
        (* 0.0072644182 t_1))
       (* 0.0005064034 t_2))
      (* 0.0001789971 t_3))
     (+
      (+
       (+
        (+
         (+ (+ 1.0 (* 0.7715471019 (* x x))) (* 0.2909738639 t_0))
         (* 0.0694555761 t_1))
        (* 0.0140005442 t_2))
       (* 0.0008327945 t_3))
      (* (* 2.0 0.0001789971) (* t_3 (* x x)))))
    x)))
double code(double x) {
	double t_0 = (x * x) * (x * x);
	double t_1 = t_0 * (x * x);
	double t_2 = t_1 * (x * x);
	double t_3 = t_2 * (x * x);
	return ((((((1.0 + (0.1049934947 * (x * x))) + (0.0424060604 * t_0)) + (0.0072644182 * t_1)) + (0.0005064034 * t_2)) + (0.0001789971 * t_3)) / ((((((1.0 + (0.7715471019 * (x * x))) + (0.2909738639 * t_0)) + (0.0694555761 * t_1)) + (0.0140005442 * t_2)) + (0.0008327945 * t_3)) + ((2.0 * 0.0001789971) * (t_3 * (x * x))))) * x;
}
real(8) function code(x)
    real(8), intent (in) :: x
    real(8) :: t_0
    real(8) :: t_1
    real(8) :: t_2
    real(8) :: t_3
    t_0 = (x * x) * (x * x)
    t_1 = t_0 * (x * x)
    t_2 = t_1 * (x * x)
    t_3 = t_2 * (x * x)
    code = ((((((1.0d0 + (0.1049934947d0 * (x * x))) + (0.0424060604d0 * t_0)) + (0.0072644182d0 * t_1)) + (0.0005064034d0 * t_2)) + (0.0001789971d0 * t_3)) / ((((((1.0d0 + (0.7715471019d0 * (x * x))) + (0.2909738639d0 * t_0)) + (0.0694555761d0 * t_1)) + (0.0140005442d0 * t_2)) + (0.0008327945d0 * t_3)) + ((2.0d0 * 0.0001789971d0) * (t_3 * (x * x))))) * x
end function
public static double code(double x) {
	double t_0 = (x * x) * (x * x);
	double t_1 = t_0 * (x * x);
	double t_2 = t_1 * (x * x);
	double t_3 = t_2 * (x * x);
	return ((((((1.0 + (0.1049934947 * (x * x))) + (0.0424060604 * t_0)) + (0.0072644182 * t_1)) + (0.0005064034 * t_2)) + (0.0001789971 * t_3)) / ((((((1.0 + (0.7715471019 * (x * x))) + (0.2909738639 * t_0)) + (0.0694555761 * t_1)) + (0.0140005442 * t_2)) + (0.0008327945 * t_3)) + ((2.0 * 0.0001789971) * (t_3 * (x * x))))) * x;
}
def code(x):
	t_0 = (x * x) * (x * x)
	t_1 = t_0 * (x * x)
	t_2 = t_1 * (x * x)
	t_3 = t_2 * (x * x)
	return ((((((1.0 + (0.1049934947 * (x * x))) + (0.0424060604 * t_0)) + (0.0072644182 * t_1)) + (0.0005064034 * t_2)) + (0.0001789971 * t_3)) / ((((((1.0 + (0.7715471019 * (x * x))) + (0.2909738639 * t_0)) + (0.0694555761 * t_1)) + (0.0140005442 * t_2)) + (0.0008327945 * t_3)) + ((2.0 * 0.0001789971) * (t_3 * (x * x))))) * x
function code(x)
	t_0 = Float64(Float64(x * x) * Float64(x * x))
	t_1 = Float64(t_0 * Float64(x * x))
	t_2 = Float64(t_1 * Float64(x * x))
	t_3 = Float64(t_2 * Float64(x * x))
	return Float64(Float64(Float64(Float64(Float64(Float64(Float64(1.0 + Float64(0.1049934947 * Float64(x * x))) + Float64(0.0424060604 * t_0)) + Float64(0.0072644182 * t_1)) + Float64(0.0005064034 * t_2)) + Float64(0.0001789971 * t_3)) / Float64(Float64(Float64(Float64(Float64(Float64(1.0 + Float64(0.7715471019 * Float64(x * x))) + Float64(0.2909738639 * t_0)) + Float64(0.0694555761 * t_1)) + Float64(0.0140005442 * t_2)) + Float64(0.0008327945 * t_3)) + Float64(Float64(2.0 * 0.0001789971) * Float64(t_3 * Float64(x * x))))) * x)
end
function tmp = code(x)
	t_0 = (x * x) * (x * x);
	t_1 = t_0 * (x * x);
	t_2 = t_1 * (x * x);
	t_3 = t_2 * (x * x);
	tmp = ((((((1.0 + (0.1049934947 * (x * x))) + (0.0424060604 * t_0)) + (0.0072644182 * t_1)) + (0.0005064034 * t_2)) + (0.0001789971 * t_3)) / ((((((1.0 + (0.7715471019 * (x * x))) + (0.2909738639 * t_0)) + (0.0694555761 * t_1)) + (0.0140005442 * t_2)) + (0.0008327945 * t_3)) + ((2.0 * 0.0001789971) * (t_3 * (x * x))))) * x;
end
code[x_] := Block[{t$95$0 = N[(N[(x * x), $MachinePrecision] * N[(x * x), $MachinePrecision]), $MachinePrecision]}, Block[{t$95$1 = N[(t$95$0 * N[(x * x), $MachinePrecision]), $MachinePrecision]}, Block[{t$95$2 = N[(t$95$1 * N[(x * x), $MachinePrecision]), $MachinePrecision]}, Block[{t$95$3 = N[(t$95$2 * N[(x * x), $MachinePrecision]), $MachinePrecision]}, N[(N[(N[(N[(N[(N[(N[(1.0 + N[(0.1049934947 * N[(x * x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(0.0424060604 * t$95$0), $MachinePrecision]), $MachinePrecision] + N[(0.0072644182 * t$95$1), $MachinePrecision]), $MachinePrecision] + N[(0.0005064034 * t$95$2), $MachinePrecision]), $MachinePrecision] + N[(0.0001789971 * t$95$3), $MachinePrecision]), $MachinePrecision] / N[(N[(N[(N[(N[(N[(1.0 + N[(0.7715471019 * N[(x * x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(0.2909738639 * t$95$0), $MachinePrecision]), $MachinePrecision] + N[(0.0694555761 * t$95$1), $MachinePrecision]), $MachinePrecision] + N[(0.0140005442 * t$95$2), $MachinePrecision]), $MachinePrecision] + N[(0.0008327945 * t$95$3), $MachinePrecision]), $MachinePrecision] + N[(N[(2.0 * 0.0001789971), $MachinePrecision] * N[(t$95$3 * N[(x * x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * x), $MachinePrecision]]]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \left(x \cdot x\right) \cdot \left(x \cdot x\right)\\
t_1 := t_0 \cdot \left(x \cdot x\right)\\
t_2 := t_1 \cdot \left(x \cdot x\right)\\
t_3 := t_2 \cdot \left(x \cdot x\right)\\
\frac{\left(\left(\left(\left(1 + 0.1049934947 \cdot \left(x \cdot x\right)\right) + 0.0424060604 \cdot t_0\right) + 0.0072644182 \cdot t_1\right) + 0.0005064034 \cdot t_2\right) + 0.0001789971 \cdot t_3}{\left(\left(\left(\left(\left(1 + 0.7715471019 \cdot \left(x \cdot x\right)\right) + 0.2909738639 \cdot t_0\right) + 0.0694555761 \cdot t_1\right) + 0.0140005442 \cdot t_2\right) + 0.0008327945 \cdot t_3\right) + \left(2 \cdot 0.0001789971\right) \cdot \left(t_3 \cdot \left(x \cdot x\right)\right)} \cdot x
\end{array}
\end{array}

Alternative 1: 100.0% accurate, 1.0× speedup?

\[\begin{array}{l} x_m = \left|x\right| \\ x_s = \mathsf{copysign}\left(1, x\right) \\ \begin{array}{l} t_0 := \left(x_m \cdot x_m\right) \cdot \left(x_m \cdot x_m\right)\\ t_1 := \left(x_m \cdot x_m\right) \cdot t_0\\ t_2 := \left(x_m \cdot x_m\right) \cdot t_1\\ t_3 := \left(x_m \cdot x_m\right) \cdot t_2\\ x_s \cdot \begin{array}{l} \mathbf{if}\;x_m \leq 2000:\\ \;\;\;\;x_m \cdot \frac{\left(\left(\left(\left(1 + 0.1049934947 \cdot \left(x_m \cdot x_m\right)\right) + 0.0424060604 \cdot t_0\right) + 0.0072644182 \cdot t_1\right) + 0.0005064034 \cdot t_2\right) + 0.0001789971 \cdot t_3}{\left(\left(\left(\left(\left(1 + \left(x_m \cdot x_m\right) \cdot 0.7715471019\right) + t_0 \cdot 0.2909738639\right) + t_1 \cdot 0.0694555761\right) + t_2 \cdot 0.0140005442\right) + t_3 \cdot 0.0008327945\right) + 0.0003579942 \cdot \left(\left(x_m \cdot x_m\right) \cdot t_3\right)}\\ \mathbf{else}:\\ \;\;\;\;\frac{0.5}{x_m} + \frac{0.2514179000665374}{{x_m}^{3}}\\ \end{array} \end{array} \end{array} \]
x_m = (fabs.f64 x)
x_s = (copysign.f64 1 x)
(FPCore (x_s x_m)
 :precision binary64
 (let* ((t_0 (* (* x_m x_m) (* x_m x_m)))
        (t_1 (* (* x_m x_m) t_0))
        (t_2 (* (* x_m x_m) t_1))
        (t_3 (* (* x_m x_m) t_2)))
   (*
    x_s
    (if (<= x_m 2000.0)
      (*
       x_m
       (/
        (+
         (+
          (+
           (+ (+ 1.0 (* 0.1049934947 (* x_m x_m))) (* 0.0424060604 t_0))
           (* 0.0072644182 t_1))
          (* 0.0005064034 t_2))
         (* 0.0001789971 t_3))
        (+
         (+
          (+
           (+
            (+ (+ 1.0 (* (* x_m x_m) 0.7715471019)) (* t_0 0.2909738639))
            (* t_1 0.0694555761))
           (* t_2 0.0140005442))
          (* t_3 0.0008327945))
         (* 0.0003579942 (* (* x_m x_m) t_3)))))
      (+ (/ 0.5 x_m) (/ 0.2514179000665374 (pow x_m 3.0)))))))
x_m = fabs(x);
x_s = copysign(1.0, x);
double code(double x_s, double x_m) {
	double t_0 = (x_m * x_m) * (x_m * x_m);
	double t_1 = (x_m * x_m) * t_0;
	double t_2 = (x_m * x_m) * t_1;
	double t_3 = (x_m * x_m) * t_2;
	double tmp;
	if (x_m <= 2000.0) {
		tmp = x_m * ((((((1.0 + (0.1049934947 * (x_m * x_m))) + (0.0424060604 * t_0)) + (0.0072644182 * t_1)) + (0.0005064034 * t_2)) + (0.0001789971 * t_3)) / ((((((1.0 + ((x_m * x_m) * 0.7715471019)) + (t_0 * 0.2909738639)) + (t_1 * 0.0694555761)) + (t_2 * 0.0140005442)) + (t_3 * 0.0008327945)) + (0.0003579942 * ((x_m * x_m) * t_3))));
	} else {
		tmp = (0.5 / x_m) + (0.2514179000665374 / pow(x_m, 3.0));
	}
	return x_s * tmp;
}
x_m = abs(x)
x_s = copysign(1.0d0, x)
real(8) function code(x_s, x_m)
    real(8), intent (in) :: x_s
    real(8), intent (in) :: x_m
    real(8) :: t_0
    real(8) :: t_1
    real(8) :: t_2
    real(8) :: t_3
    real(8) :: tmp
    t_0 = (x_m * x_m) * (x_m * x_m)
    t_1 = (x_m * x_m) * t_0
    t_2 = (x_m * x_m) * t_1
    t_3 = (x_m * x_m) * t_2
    if (x_m <= 2000.0d0) then
        tmp = x_m * ((((((1.0d0 + (0.1049934947d0 * (x_m * x_m))) + (0.0424060604d0 * t_0)) + (0.0072644182d0 * t_1)) + (0.0005064034d0 * t_2)) + (0.0001789971d0 * t_3)) / ((((((1.0d0 + ((x_m * x_m) * 0.7715471019d0)) + (t_0 * 0.2909738639d0)) + (t_1 * 0.0694555761d0)) + (t_2 * 0.0140005442d0)) + (t_3 * 0.0008327945d0)) + (0.0003579942d0 * ((x_m * x_m) * t_3))))
    else
        tmp = (0.5d0 / x_m) + (0.2514179000665374d0 / (x_m ** 3.0d0))
    end if
    code = x_s * tmp
end function
x_m = Math.abs(x);
x_s = Math.copySign(1.0, x);
public static double code(double x_s, double x_m) {
	double t_0 = (x_m * x_m) * (x_m * x_m);
	double t_1 = (x_m * x_m) * t_0;
	double t_2 = (x_m * x_m) * t_1;
	double t_3 = (x_m * x_m) * t_2;
	double tmp;
	if (x_m <= 2000.0) {
		tmp = x_m * ((((((1.0 + (0.1049934947 * (x_m * x_m))) + (0.0424060604 * t_0)) + (0.0072644182 * t_1)) + (0.0005064034 * t_2)) + (0.0001789971 * t_3)) / ((((((1.0 + ((x_m * x_m) * 0.7715471019)) + (t_0 * 0.2909738639)) + (t_1 * 0.0694555761)) + (t_2 * 0.0140005442)) + (t_3 * 0.0008327945)) + (0.0003579942 * ((x_m * x_m) * t_3))));
	} else {
		tmp = (0.5 / x_m) + (0.2514179000665374 / Math.pow(x_m, 3.0));
	}
	return x_s * tmp;
}
x_m = math.fabs(x)
x_s = math.copysign(1.0, x)
def code(x_s, x_m):
	t_0 = (x_m * x_m) * (x_m * x_m)
	t_1 = (x_m * x_m) * t_0
	t_2 = (x_m * x_m) * t_1
	t_3 = (x_m * x_m) * t_2
	tmp = 0
	if x_m <= 2000.0:
		tmp = x_m * ((((((1.0 + (0.1049934947 * (x_m * x_m))) + (0.0424060604 * t_0)) + (0.0072644182 * t_1)) + (0.0005064034 * t_2)) + (0.0001789971 * t_3)) / ((((((1.0 + ((x_m * x_m) * 0.7715471019)) + (t_0 * 0.2909738639)) + (t_1 * 0.0694555761)) + (t_2 * 0.0140005442)) + (t_3 * 0.0008327945)) + (0.0003579942 * ((x_m * x_m) * t_3))))
	else:
		tmp = (0.5 / x_m) + (0.2514179000665374 / math.pow(x_m, 3.0))
	return x_s * tmp
x_m = abs(x)
x_s = copysign(1.0, x)
function code(x_s, x_m)
	t_0 = Float64(Float64(x_m * x_m) * Float64(x_m * x_m))
	t_1 = Float64(Float64(x_m * x_m) * t_0)
	t_2 = Float64(Float64(x_m * x_m) * t_1)
	t_3 = Float64(Float64(x_m * x_m) * t_2)
	tmp = 0.0
	if (x_m <= 2000.0)
		tmp = Float64(x_m * Float64(Float64(Float64(Float64(Float64(Float64(1.0 + Float64(0.1049934947 * Float64(x_m * x_m))) + Float64(0.0424060604 * t_0)) + Float64(0.0072644182 * t_1)) + Float64(0.0005064034 * t_2)) + Float64(0.0001789971 * t_3)) / Float64(Float64(Float64(Float64(Float64(Float64(1.0 + Float64(Float64(x_m * x_m) * 0.7715471019)) + Float64(t_0 * 0.2909738639)) + Float64(t_1 * 0.0694555761)) + Float64(t_2 * 0.0140005442)) + Float64(t_3 * 0.0008327945)) + Float64(0.0003579942 * Float64(Float64(x_m * x_m) * t_3)))));
	else
		tmp = Float64(Float64(0.5 / x_m) + Float64(0.2514179000665374 / (x_m ^ 3.0)));
	end
	return Float64(x_s * tmp)
end
x_m = abs(x);
x_s = sign(x) * abs(1.0);
function tmp_2 = code(x_s, x_m)
	t_0 = (x_m * x_m) * (x_m * x_m);
	t_1 = (x_m * x_m) * t_0;
	t_2 = (x_m * x_m) * t_1;
	t_3 = (x_m * x_m) * t_2;
	tmp = 0.0;
	if (x_m <= 2000.0)
		tmp = x_m * ((((((1.0 + (0.1049934947 * (x_m * x_m))) + (0.0424060604 * t_0)) + (0.0072644182 * t_1)) + (0.0005064034 * t_2)) + (0.0001789971 * t_3)) / ((((((1.0 + ((x_m * x_m) * 0.7715471019)) + (t_0 * 0.2909738639)) + (t_1 * 0.0694555761)) + (t_2 * 0.0140005442)) + (t_3 * 0.0008327945)) + (0.0003579942 * ((x_m * x_m) * t_3))));
	else
		tmp = (0.5 / x_m) + (0.2514179000665374 / (x_m ^ 3.0));
	end
	tmp_2 = x_s * tmp;
end
x_m = N[Abs[x], $MachinePrecision]
x_s = N[With[{TMP1 = Abs[1.0], TMP2 = Sign[x]}, TMP1 * If[TMP2 == 0, 1, TMP2]], $MachinePrecision]
code[x$95$s_, x$95$m_] := Block[{t$95$0 = N[(N[(x$95$m * x$95$m), $MachinePrecision] * N[(x$95$m * x$95$m), $MachinePrecision]), $MachinePrecision]}, Block[{t$95$1 = N[(N[(x$95$m * x$95$m), $MachinePrecision] * t$95$0), $MachinePrecision]}, Block[{t$95$2 = N[(N[(x$95$m * x$95$m), $MachinePrecision] * t$95$1), $MachinePrecision]}, Block[{t$95$3 = N[(N[(x$95$m * x$95$m), $MachinePrecision] * t$95$2), $MachinePrecision]}, N[(x$95$s * If[LessEqual[x$95$m, 2000.0], N[(x$95$m * N[(N[(N[(N[(N[(N[(1.0 + N[(0.1049934947 * N[(x$95$m * x$95$m), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(0.0424060604 * t$95$0), $MachinePrecision]), $MachinePrecision] + N[(0.0072644182 * t$95$1), $MachinePrecision]), $MachinePrecision] + N[(0.0005064034 * t$95$2), $MachinePrecision]), $MachinePrecision] + N[(0.0001789971 * t$95$3), $MachinePrecision]), $MachinePrecision] / N[(N[(N[(N[(N[(N[(1.0 + N[(N[(x$95$m * x$95$m), $MachinePrecision] * 0.7715471019), $MachinePrecision]), $MachinePrecision] + N[(t$95$0 * 0.2909738639), $MachinePrecision]), $MachinePrecision] + N[(t$95$1 * 0.0694555761), $MachinePrecision]), $MachinePrecision] + N[(t$95$2 * 0.0140005442), $MachinePrecision]), $MachinePrecision] + N[(t$95$3 * 0.0008327945), $MachinePrecision]), $MachinePrecision] + N[(0.0003579942 * N[(N[(x$95$m * x$95$m), $MachinePrecision] * t$95$3), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(N[(0.5 / x$95$m), $MachinePrecision] + N[(0.2514179000665374 / N[Power[x$95$m, 3.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]), $MachinePrecision]]]]]
\begin{array}{l}
x_m = \left|x\right|
\\
x_s = \mathsf{copysign}\left(1, x\right)

\\
\begin{array}{l}
t_0 := \left(x_m \cdot x_m\right) \cdot \left(x_m \cdot x_m\right)\\
t_1 := \left(x_m \cdot x_m\right) \cdot t_0\\
t_2 := \left(x_m \cdot x_m\right) \cdot t_1\\
t_3 := \left(x_m \cdot x_m\right) \cdot t_2\\
x_s \cdot \begin{array}{l}
\mathbf{if}\;x_m \leq 2000:\\
\;\;\;\;x_m \cdot \frac{\left(\left(\left(\left(1 + 0.1049934947 \cdot \left(x_m \cdot x_m\right)\right) + 0.0424060604 \cdot t_0\right) + 0.0072644182 \cdot t_1\right) + 0.0005064034 \cdot t_2\right) + 0.0001789971 \cdot t_3}{\left(\left(\left(\left(\left(1 + \left(x_m \cdot x_m\right) \cdot 0.7715471019\right) + t_0 \cdot 0.2909738639\right) + t_1 \cdot 0.0694555761\right) + t_2 \cdot 0.0140005442\right) + t_3 \cdot 0.0008327945\right) + 0.0003579942 \cdot \left(\left(x_m \cdot x_m\right) \cdot t_3\right)}\\

\mathbf{else}:\\
\;\;\;\;\frac{0.5}{x_m} + \frac{0.2514179000665374}{{x_m}^{3}}\\


\end{array}
\end{array}
\end{array}
Derivation
    &prev;&pcontext;&pcontext2;&ctx;
  1. Add Preprocessing

Alternative 2: 100.0% accurate, 1.0× speedup?

\[\begin{array}{l} x_m = \left|x\right| \\ x_s = \mathsf{copysign}\left(1, x\right) \\ \begin{array}{l} t_0 := x_m \cdot \left(x_m \cdot \left(x_m \cdot x_m\right)\right)\\ t_1 := \left(x_m \cdot x_m\right) \cdot t_0\\ t_2 := \left(x_m \cdot x_m\right) \cdot t_1\\ t_3 := t_0 \cdot t_1\\ x_s \cdot \begin{array}{l} \mathbf{if}\;x_m \leq 15000:\\ \;\;\;\;x_m \cdot \frac{0.0001789971 \cdot t_3 + \left(0.0005064034 \cdot t_2 + \left(0.0072644182 \cdot t_1 + \left(1 + \left(0.1049934947 \cdot \left(x_m \cdot x_m\right) + \left(x_m \cdot x_m\right) \cdot \left(\left(x_m \cdot x_m\right) \cdot 0.0424060604\right)\right)\right)\right)\right)}{0.0003579942 \cdot \left(t_0 \cdot t_2\right) + \left(0.0008327945 \cdot t_3 + \left(0.0140005442 \cdot t_2 + \left(0.0694555761 \cdot t_1 + \left(\left(1 + \left(x_m \cdot x_m\right) \cdot 0.7715471019\right) + 0.2909738639 \cdot t_0\right)\right)\right)\right)}\\ \mathbf{else}:\\ \;\;\;\;\frac{0.5}{x_m} + \frac{0.2514179000665374}{{x_m}^{3}}\\ \end{array} \end{array} \end{array} \]
x_m = (fabs.f64 x)
x_s = (copysign.f64 1 x)
(FPCore (x_s x_m)
 :precision binary64
 (let* ((t_0 (* x_m (* x_m (* x_m x_m))))
        (t_1 (* (* x_m x_m) t_0))
        (t_2 (* (* x_m x_m) t_1))
        (t_3 (* t_0 t_1)))
   (*
    x_s
    (if (<= x_m 15000.0)
      (*
       x_m
       (/
        (+
         (* 0.0001789971 t_3)
         (+
          (* 0.0005064034 t_2)
          (+
           (* 0.0072644182 t_1)
           (+
            1.0
            (+
             (* 0.1049934947 (* x_m x_m))
             (* (* x_m x_m) (* (* x_m x_m) 0.0424060604)))))))
        (+
         (* 0.0003579942 (* t_0 t_2))
         (+
          (* 0.0008327945 t_3)
          (+
           (* 0.0140005442 t_2)
           (+
            (* 0.0694555761 t_1)
            (+ (+ 1.0 (* (* x_m x_m) 0.7715471019)) (* 0.2909738639 t_0))))))))
      (+ (/ 0.5 x_m) (/ 0.2514179000665374 (pow x_m 3.0)))))))
x_m = fabs(x);
x_s = copysign(1.0, x);
double code(double x_s, double x_m) {
	double t_0 = x_m * (x_m * (x_m * x_m));
	double t_1 = (x_m * x_m) * t_0;
	double t_2 = (x_m * x_m) * t_1;
	double t_3 = t_0 * t_1;
	double tmp;
	if (x_m <= 15000.0) {
		tmp = x_m * (((0.0001789971 * t_3) + ((0.0005064034 * t_2) + ((0.0072644182 * t_1) + (1.0 + ((0.1049934947 * (x_m * x_m)) + ((x_m * x_m) * ((x_m * x_m) * 0.0424060604))))))) / ((0.0003579942 * (t_0 * t_2)) + ((0.0008327945 * t_3) + ((0.0140005442 * t_2) + ((0.0694555761 * t_1) + ((1.0 + ((x_m * x_m) * 0.7715471019)) + (0.2909738639 * t_0)))))));
	} else {
		tmp = (0.5 / x_m) + (0.2514179000665374 / pow(x_m, 3.0));
	}
	return x_s * tmp;
}
x_m = abs(x)
x_s = copysign(1.0d0, x)
real(8) function code(x_s, x_m)
    real(8), intent (in) :: x_s
    real(8), intent (in) :: x_m
    real(8) :: t_0
    real(8) :: t_1
    real(8) :: t_2
    real(8) :: t_3
    real(8) :: tmp
    t_0 = x_m * (x_m * (x_m * x_m))
    t_1 = (x_m * x_m) * t_0
    t_2 = (x_m * x_m) * t_1
    t_3 = t_0 * t_1
    if (x_m <= 15000.0d0) then
        tmp = x_m * (((0.0001789971d0 * t_3) + ((0.0005064034d0 * t_2) + ((0.0072644182d0 * t_1) + (1.0d0 + ((0.1049934947d0 * (x_m * x_m)) + ((x_m * x_m) * ((x_m * x_m) * 0.0424060604d0))))))) / ((0.0003579942d0 * (t_0 * t_2)) + ((0.0008327945d0 * t_3) + ((0.0140005442d0 * t_2) + ((0.0694555761d0 * t_1) + ((1.0d0 + ((x_m * x_m) * 0.7715471019d0)) + (0.2909738639d0 * t_0)))))))
    else
        tmp = (0.5d0 / x_m) + (0.2514179000665374d0 / (x_m ** 3.0d0))
    end if
    code = x_s * tmp
end function
x_m = Math.abs(x);
x_s = Math.copySign(1.0, x);
public static double code(double x_s, double x_m) {
	double t_0 = x_m * (x_m * (x_m * x_m));
	double t_1 = (x_m * x_m) * t_0;
	double t_2 = (x_m * x_m) * t_1;
	double t_3 = t_0 * t_1;
	double tmp;
	if (x_m <= 15000.0) {
		tmp = x_m * (((0.0001789971 * t_3) + ((0.0005064034 * t_2) + ((0.0072644182 * t_1) + (1.0 + ((0.1049934947 * (x_m * x_m)) + ((x_m * x_m) * ((x_m * x_m) * 0.0424060604))))))) / ((0.0003579942 * (t_0 * t_2)) + ((0.0008327945 * t_3) + ((0.0140005442 * t_2) + ((0.0694555761 * t_1) + ((1.0 + ((x_m * x_m) * 0.7715471019)) + (0.2909738639 * t_0)))))));
	} else {
		tmp = (0.5 / x_m) + (0.2514179000665374 / Math.pow(x_m, 3.0));
	}
	return x_s * tmp;
}
x_m = math.fabs(x)
x_s = math.copysign(1.0, x)
def code(x_s, x_m):
	t_0 = x_m * (x_m * (x_m * x_m))
	t_1 = (x_m * x_m) * t_0
	t_2 = (x_m * x_m) * t_1
	t_3 = t_0 * t_1
	tmp = 0
	if x_m <= 15000.0:
		tmp = x_m * (((0.0001789971 * t_3) + ((0.0005064034 * t_2) + ((0.0072644182 * t_1) + (1.0 + ((0.1049934947 * (x_m * x_m)) + ((x_m * x_m) * ((x_m * x_m) * 0.0424060604))))))) / ((0.0003579942 * (t_0 * t_2)) + ((0.0008327945 * t_3) + ((0.0140005442 * t_2) + ((0.0694555761 * t_1) + ((1.0 + ((x_m * x_m) * 0.7715471019)) + (0.2909738639 * t_0)))))))
	else:
		tmp = (0.5 / x_m) + (0.2514179000665374 / math.pow(x_m, 3.0))
	return x_s * tmp
x_m = abs(x)
x_s = copysign(1.0, x)
function code(x_s, x_m)
	t_0 = Float64(x_m * Float64(x_m * Float64(x_m * x_m)))
	t_1 = Float64(Float64(x_m * x_m) * t_0)
	t_2 = Float64(Float64(x_m * x_m) * t_1)
	t_3 = Float64(t_0 * t_1)
	tmp = 0.0
	if (x_m <= 15000.0)
		tmp = Float64(x_m * Float64(Float64(Float64(0.0001789971 * t_3) + Float64(Float64(0.0005064034 * t_2) + Float64(Float64(0.0072644182 * t_1) + Float64(1.0 + Float64(Float64(0.1049934947 * Float64(x_m * x_m)) + Float64(Float64(x_m * x_m) * Float64(Float64(x_m * x_m) * 0.0424060604))))))) / Float64(Float64(0.0003579942 * Float64(t_0 * t_2)) + Float64(Float64(0.0008327945 * t_3) + Float64(Float64(0.0140005442 * t_2) + Float64(Float64(0.0694555761 * t_1) + Float64(Float64(1.0 + Float64(Float64(x_m * x_m) * 0.7715471019)) + Float64(0.2909738639 * t_0))))))));
	else
		tmp = Float64(Float64(0.5 / x_m) + Float64(0.2514179000665374 / (x_m ^ 3.0)));
	end
	return Float64(x_s * tmp)
end
x_m = abs(x);
x_s = sign(x) * abs(1.0);
function tmp_2 = code(x_s, x_m)
	t_0 = x_m * (x_m * (x_m * x_m));
	t_1 = (x_m * x_m) * t_0;
	t_2 = (x_m * x_m) * t_1;
	t_3 = t_0 * t_1;
	tmp = 0.0;
	if (x_m <= 15000.0)
		tmp = x_m * (((0.0001789971 * t_3) + ((0.0005064034 * t_2) + ((0.0072644182 * t_1) + (1.0 + ((0.1049934947 * (x_m * x_m)) + ((x_m * x_m) * ((x_m * x_m) * 0.0424060604))))))) / ((0.0003579942 * (t_0 * t_2)) + ((0.0008327945 * t_3) + ((0.0140005442 * t_2) + ((0.0694555761 * t_1) + ((1.0 + ((x_m * x_m) * 0.7715471019)) + (0.2909738639 * t_0)))))));
	else
		tmp = (0.5 / x_m) + (0.2514179000665374 / (x_m ^ 3.0));
	end
	tmp_2 = x_s * tmp;
end
x_m = N[Abs[x], $MachinePrecision]
x_s = N[With[{TMP1 = Abs[1.0], TMP2 = Sign[x]}, TMP1 * If[TMP2 == 0, 1, TMP2]], $MachinePrecision]
code[x$95$s_, x$95$m_] := Block[{t$95$0 = N[(x$95$m * N[(x$95$m * N[(x$95$m * x$95$m), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]}, Block[{t$95$1 = N[(N[(x$95$m * x$95$m), $MachinePrecision] * t$95$0), $MachinePrecision]}, Block[{t$95$2 = N[(N[(x$95$m * x$95$m), $MachinePrecision] * t$95$1), $MachinePrecision]}, Block[{t$95$3 = N[(t$95$0 * t$95$1), $MachinePrecision]}, N[(x$95$s * If[LessEqual[x$95$m, 15000.0], N[(x$95$m * N[(N[(N[(0.0001789971 * t$95$3), $MachinePrecision] + N[(N[(0.0005064034 * t$95$2), $MachinePrecision] + N[(N[(0.0072644182 * t$95$1), $MachinePrecision] + N[(1.0 + N[(N[(0.1049934947 * N[(x$95$m * x$95$m), $MachinePrecision]), $MachinePrecision] + N[(N[(x$95$m * x$95$m), $MachinePrecision] * N[(N[(x$95$m * x$95$m), $MachinePrecision] * 0.0424060604), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[(N[(0.0003579942 * N[(t$95$0 * t$95$2), $MachinePrecision]), $MachinePrecision] + N[(N[(0.0008327945 * t$95$3), $MachinePrecision] + N[(N[(0.0140005442 * t$95$2), $MachinePrecision] + N[(N[(0.0694555761 * t$95$1), $MachinePrecision] + N[(N[(1.0 + N[(N[(x$95$m * x$95$m), $MachinePrecision] * 0.7715471019), $MachinePrecision]), $MachinePrecision] + N[(0.2909738639 * t$95$0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(N[(0.5 / x$95$m), $MachinePrecision] + N[(0.2514179000665374 / N[Power[x$95$m, 3.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]), $MachinePrecision]]]]]
\begin{array}{l}
x_m = \left|x\right|
\\
x_s = \mathsf{copysign}\left(1, x\right)

\\
\begin{array}{l}
t_0 := x_m \cdot \left(x_m \cdot \left(x_m \cdot x_m\right)\right)\\
t_1 := \left(x_m \cdot x_m\right) \cdot t_0\\
t_2 := \left(x_m \cdot x_m\right) \cdot t_1\\
t_3 := t_0 \cdot t_1\\
x_s \cdot \begin{array}{l}
\mathbf{if}\;x_m \leq 15000:\\
\;\;\;\;x_m \cdot \frac{0.0001789971 \cdot t_3 + \left(0.0005064034 \cdot t_2 + \left(0.0072644182 \cdot t_1 + \left(1 + \left(0.1049934947 \cdot \left(x_m \cdot x_m\right) + \left(x_m \cdot x_m\right) \cdot \left(\left(x_m \cdot x_m\right) \cdot 0.0424060604\right)\right)\right)\right)\right)}{0.0003579942 \cdot \left(t_0 \cdot t_2\right) + \left(0.0008327945 \cdot t_3 + \left(0.0140005442 \cdot t_2 + \left(0.0694555761 \cdot t_1 + \left(\left(1 + \left(x_m \cdot x_m\right) \cdot 0.7715471019\right) + 0.2909738639 \cdot t_0\right)\right)\right)\right)}\\

\mathbf{else}:\\
\;\;\;\;\frac{0.5}{x_m} + \frac{0.2514179000665374}{{x_m}^{3}}\\


\end{array}
\end{array}
\end{array}
Derivation
    &prev;&pcontext;&pcontext2;&ctx;
  1. Add Preprocessing

Alternative 3: 99.2% accurate, 1.6× speedup?

\[\begin{array}{l} x_m = \left|x\right| \\ x_s = \mathsf{copysign}\left(1, x\right) \\ x_s \cdot \begin{array}{l} \mathbf{if}\;x_m \leq 0.9:\\ \;\;\;\;x_m\\ \mathbf{else}:\\ \;\;\;\;\frac{0.5}{x_m} + \frac{0.2514179000665374}{{x_m}^{3}}\\ \end{array} \end{array} \]
x_m = (fabs.f64 x)
x_s = (copysign.f64 1 x)
(FPCore (x_s x_m)
 :precision binary64
 (*
  x_s
  (if (<= x_m 0.9) x_m (+ (/ 0.5 x_m) (/ 0.2514179000665374 (pow x_m 3.0))))))
x_m = fabs(x);
x_s = copysign(1.0, x);
double code(double x_s, double x_m) {
	double tmp;
	if (x_m <= 0.9) {
		tmp = x_m;
	} else {
		tmp = (0.5 / x_m) + (0.2514179000665374 / pow(x_m, 3.0));
	}
	return x_s * tmp;
}
x_m = abs(x)
x_s = copysign(1.0d0, x)
real(8) function code(x_s, x_m)
    real(8), intent (in) :: x_s
    real(8), intent (in) :: x_m
    real(8) :: tmp
    if (x_m <= 0.9d0) then
        tmp = x_m
    else
        tmp = (0.5d0 / x_m) + (0.2514179000665374d0 / (x_m ** 3.0d0))
    end if
    code = x_s * tmp
end function
x_m = Math.abs(x);
x_s = Math.copySign(1.0, x);
public static double code(double x_s, double x_m) {
	double tmp;
	if (x_m <= 0.9) {
		tmp = x_m;
	} else {
		tmp = (0.5 / x_m) + (0.2514179000665374 / Math.pow(x_m, 3.0));
	}
	return x_s * tmp;
}
x_m = math.fabs(x)
x_s = math.copysign(1.0, x)
def code(x_s, x_m):
	tmp = 0
	if x_m <= 0.9:
		tmp = x_m
	else:
		tmp = (0.5 / x_m) + (0.2514179000665374 / math.pow(x_m, 3.0))
	return x_s * tmp
x_m = abs(x)
x_s = copysign(1.0, x)
function code(x_s, x_m)
	tmp = 0.0
	if (x_m <= 0.9)
		tmp = x_m;
	else
		tmp = Float64(Float64(0.5 / x_m) + Float64(0.2514179000665374 / (x_m ^ 3.0)));
	end
	return Float64(x_s * tmp)
end
x_m = abs(x);
x_s = sign(x) * abs(1.0);
function tmp_2 = code(x_s, x_m)
	tmp = 0.0;
	if (x_m <= 0.9)
		tmp = x_m;
	else
		tmp = (0.5 / x_m) + (0.2514179000665374 / (x_m ^ 3.0));
	end
	tmp_2 = x_s * tmp;
end
x_m = N[Abs[x], $MachinePrecision]
x_s = N[With[{TMP1 = Abs[1.0], TMP2 = Sign[x]}, TMP1 * If[TMP2 == 0, 1, TMP2]], $MachinePrecision]
code[x$95$s_, x$95$m_] := N[(x$95$s * If[LessEqual[x$95$m, 0.9], x$95$m, N[(N[(0.5 / x$95$m), $MachinePrecision] + N[(0.2514179000665374 / N[Power[x$95$m, 3.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]), $MachinePrecision]
\begin{array}{l}
x_m = \left|x\right|
\\
x_s = \mathsf{copysign}\left(1, x\right)

\\
x_s \cdot \begin{array}{l}
\mathbf{if}\;x_m \leq 0.9:\\
\;\;\;\;x_m\\

\mathbf{else}:\\
\;\;\;\;\frac{0.5}{x_m} + \frac{0.2514179000665374}{{x_m}^{3}}\\


\end{array}
\end{array}
Derivation
    &prev;&pcontext;&pcontext2;&ctx;
  1. Add Preprocessing

Alternative 4: 99.0% accurate, 34.2× speedup?

\[\begin{array}{l} x_m = \left|x\right| \\ x_s = \mathsf{copysign}\left(1, x\right) \\ x_s \cdot \begin{array}{l} \mathbf{if}\;x_m \leq 0.7:\\ \;\;\;\;x_m\\ \mathbf{else}:\\ \;\;\;\;\frac{0.5}{x_m}\\ \end{array} \end{array} \]
x_m = (fabs.f64 x)
x_s = (copysign.f64 1 x)
(FPCore (x_s x_m)
 :precision binary64
 (* x_s (if (<= x_m 0.7) x_m (/ 0.5 x_m))))
x_m = fabs(x);
x_s = copysign(1.0, x);
double code(double x_s, double x_m) {
	double tmp;
	if (x_m <= 0.7) {
		tmp = x_m;
	} else {
		tmp = 0.5 / x_m;
	}
	return x_s * tmp;
}
x_m = abs(x)
x_s = copysign(1.0d0, x)
real(8) function code(x_s, x_m)
    real(8), intent (in) :: x_s
    real(8), intent (in) :: x_m
    real(8) :: tmp
    if (x_m <= 0.7d0) then
        tmp = x_m
    else
        tmp = 0.5d0 / x_m
    end if
    code = x_s * tmp
end function
x_m = Math.abs(x);
x_s = Math.copySign(1.0, x);
public static double code(double x_s, double x_m) {
	double tmp;
	if (x_m <= 0.7) {
		tmp = x_m;
	} else {
		tmp = 0.5 / x_m;
	}
	return x_s * tmp;
}
x_m = math.fabs(x)
x_s = math.copysign(1.0, x)
def code(x_s, x_m):
	tmp = 0
	if x_m <= 0.7:
		tmp = x_m
	else:
		tmp = 0.5 / x_m
	return x_s * tmp
x_m = abs(x)
x_s = copysign(1.0, x)
function code(x_s, x_m)
	tmp = 0.0
	if (x_m <= 0.7)
		tmp = x_m;
	else
		tmp = Float64(0.5 / x_m);
	end
	return Float64(x_s * tmp)
end
x_m = abs(x);
x_s = sign(x) * abs(1.0);
function tmp_2 = code(x_s, x_m)
	tmp = 0.0;
	if (x_m <= 0.7)
		tmp = x_m;
	else
		tmp = 0.5 / x_m;
	end
	tmp_2 = x_s * tmp;
end
x_m = N[Abs[x], $MachinePrecision]
x_s = N[With[{TMP1 = Abs[1.0], TMP2 = Sign[x]}, TMP1 * If[TMP2 == 0, 1, TMP2]], $MachinePrecision]
code[x$95$s_, x$95$m_] := N[(x$95$s * If[LessEqual[x$95$m, 0.7], x$95$m, N[(0.5 / x$95$m), $MachinePrecision]]), $MachinePrecision]
\begin{array}{l}
x_m = \left|x\right|
\\
x_s = \mathsf{copysign}\left(1, x\right)

\\
x_s \cdot \begin{array}{l}
\mathbf{if}\;x_m \leq 0.7:\\
\;\;\;\;x_m\\

\mathbf{else}:\\
\;\;\;\;\frac{0.5}{x_m}\\


\end{array}
\end{array}
Derivation
    &prev;&pcontext;&pcontext2;&ctx;
  1. Add Preprocessing

Alternative 5: 51.7% accurate, 173.0× speedup?

\[\begin{array}{l} x_m = \left|x\right| \\ x_s = \mathsf{copysign}\left(1, x\right) \\ x_s \cdot x_m \end{array} \]
x_m = (fabs.f64 x)
x_s = (copysign.f64 1 x)
(FPCore (x_s x_m) :precision binary64 (* x_s x_m))
x_m = fabs(x);
x_s = copysign(1.0, x);
double code(double x_s, double x_m) {
	return x_s * x_m;
}
x_m = abs(x)
x_s = copysign(1.0d0, x)
real(8) function code(x_s, x_m)
    real(8), intent (in) :: x_s
    real(8), intent (in) :: x_m
    code = x_s * x_m
end function
x_m = Math.abs(x);
x_s = Math.copySign(1.0, x);
public static double code(double x_s, double x_m) {
	return x_s * x_m;
}
x_m = math.fabs(x)
x_s = math.copysign(1.0, x)
def code(x_s, x_m):
	return x_s * x_m
x_m = abs(x)
x_s = copysign(1.0, x)
function code(x_s, x_m)
	return Float64(x_s * x_m)
end
x_m = abs(x);
x_s = sign(x) * abs(1.0);
function tmp = code(x_s, x_m)
	tmp = x_s * x_m;
end
x_m = N[Abs[x], $MachinePrecision]
x_s = N[With[{TMP1 = Abs[1.0], TMP2 = Sign[x]}, TMP1 * If[TMP2 == 0, 1, TMP2]], $MachinePrecision]
code[x$95$s_, x$95$m_] := N[(x$95$s * x$95$m), $MachinePrecision]
\begin{array}{l}
x_m = \left|x\right|
\\
x_s = \mathsf{copysign}\left(1, x\right)

\\
x_s \cdot x_m
\end{array}
Derivation
    &prev;&pcontext;&pcontext2;&ctx;
  1. Add Preprocessing

Reproduce

?
herbie shell --seed 2024010 
(FPCore (x)
  :name "Jmat.Real.dawson"
  :precision binary64
  (* (/ (+ (+ (+ (+ (+ 1.0 (* 0.1049934947 (* x x))) (* 0.0424060604 (* (* x x) (* x x)))) (* 0.0072644182 (* (* (* x x) (* x x)) (* x x)))) (* 0.0005064034 (* (* (* (* x x) (* x x)) (* x x)) (* x x)))) (* 0.0001789971 (* (* (* (* (* x x) (* x x)) (* x x)) (* x x)) (* x x)))) (+ (+ (+ (+ (+ (+ 1.0 (* 0.7715471019 (* x x))) (* 0.2909738639 (* (* x x) (* x x)))) (* 0.0694555761 (* (* (* x x) (* x x)) (* x x)))) (* 0.0140005442 (* (* (* (* x x) (* x x)) (* x x)) (* x x)))) (* 0.0008327945 (* (* (* (* (* x x) (* x x)) (* x x)) (* x x)) (* x x)))) (* (* 2.0 0.0001789971) (* (* (* (* (* (* x x) (* x x)) (* x x)) (* x x)) (* x x)) (* x x))))) x))