Jmat.Real.dawson

Percentage Accurate: 53.5% → 99.6%
Time: 12.0s
Alternatives: 6
Speedup: 21.6×

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 6 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: 53.5% 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: 99.6% accurate, 8.6× speedup?

\[\begin{array}{l} x\_m = \left|x\right| \\ x\_s = \mathsf{copysign}\left(1, x\right) \\ x\_s \cdot \begin{array}{l} \mathbf{if}\;x\_m \leq 1.15:\\ \;\;\;\;x\_m \cdot \left(1 + \left(x\_m \cdot x\_m\right) \cdot \left(-0.6665536072 + \left(x\_m \cdot x\_m\right) \cdot 0.265709700396151\right)\right)\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{x\_m \cdot \left(2 - \frac{1.0056716002661497}{x\_m \cdot x\_m}\right)}\\ \end{array} \end{array} \]
x\_m = (fabs.f64 x)
x\_s = (copysign.f64 #s(literal 1 binary64) x)
(FPCore (x_s x_m)
 :precision binary64
 (*
  x_s
  (if (<= x_m 1.15)
    (*
     x_m
     (+
      1.0
      (* (* x_m x_m) (+ -0.6665536072 (* (* x_m x_m) 0.265709700396151)))))
    (/ 1.0 (* x_m (- 2.0 (/ 1.0056716002661497 (* x_m 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 <= 1.15) {
		tmp = x_m * (1.0 + ((x_m * x_m) * (-0.6665536072 + ((x_m * x_m) * 0.265709700396151))));
	} else {
		tmp = 1.0 / (x_m * (2.0 - (1.0056716002661497 / (x_m * 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 <= 1.15d0) then
        tmp = x_m * (1.0d0 + ((x_m * x_m) * ((-0.6665536072d0) + ((x_m * x_m) * 0.265709700396151d0))))
    else
        tmp = 1.0d0 / (x_m * (2.0d0 - (1.0056716002661497d0 / (x_m * 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 <= 1.15) {
		tmp = x_m * (1.0 + ((x_m * x_m) * (-0.6665536072 + ((x_m * x_m) * 0.265709700396151))));
	} else {
		tmp = 1.0 / (x_m * (2.0 - (1.0056716002661497 / (x_m * 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 <= 1.15:
		tmp = x_m * (1.0 + ((x_m * x_m) * (-0.6665536072 + ((x_m * x_m) * 0.265709700396151))))
	else:
		tmp = 1.0 / (x_m * (2.0 - (1.0056716002661497 / (x_m * 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 <= 1.15)
		tmp = Float64(x_m * Float64(1.0 + Float64(Float64(x_m * x_m) * Float64(-0.6665536072 + Float64(Float64(x_m * x_m) * 0.265709700396151)))));
	else
		tmp = Float64(1.0 / Float64(x_m * Float64(2.0 - Float64(1.0056716002661497 / Float64(x_m * 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 <= 1.15)
		tmp = x_m * (1.0 + ((x_m * x_m) * (-0.6665536072 + ((x_m * x_m) * 0.265709700396151))));
	else
		tmp = 1.0 / (x_m * (2.0 - (1.0056716002661497 / (x_m * 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, 1.15], N[(x$95$m * N[(1.0 + N[(N[(x$95$m * x$95$m), $MachinePrecision] * N[(-0.6665536072 + N[(N[(x$95$m * x$95$m), $MachinePrecision] * 0.265709700396151), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(1.0 / N[(x$95$m * N[(2.0 - N[(1.0056716002661497 / N[(x$95$m * x$95$m), $MachinePrecision]), $MachinePrecision]), $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 1.15:\\
\;\;\;\;x\_m \cdot \left(1 + \left(x\_m \cdot x\_m\right) \cdot \left(-0.6665536072 + \left(x\_m \cdot x\_m\right) \cdot 0.265709700396151\right)\right)\\

\mathbf{else}:\\
\;\;\;\;\frac{1}{x\_m \cdot \left(2 - \frac{1.0056716002661497}{x\_m \cdot x\_m}\right)}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if x < 1.1499999999999999

    1. Initial program 68.5%

      \[\frac{\left(\left(\left(\left(1 + 0.1049934947 \cdot \left(x \cdot x\right)\right) + 0.0424060604 \cdot \left(\left(x \cdot x\right) \cdot \left(x \cdot x\right)\right)\right) + 0.0072644182 \cdot \left(\left(\left(x \cdot x\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right)\right) + 0.0005064034 \cdot \left(\left(\left(\left(x \cdot x\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right)\right) + 0.0001789971 \cdot \left(\left(\left(\left(\left(x \cdot x\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right)}{\left(\left(\left(\left(\left(1 + 0.7715471019 \cdot \left(x \cdot x\right)\right) + 0.2909738639 \cdot \left(\left(x \cdot x\right) \cdot \left(x \cdot x\right)\right)\right) + 0.0694555761 \cdot \left(\left(\left(x \cdot x\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right)\right) + 0.0140005442 \cdot \left(\left(\left(\left(x \cdot x\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right)\right) + 0.0008327945 \cdot \left(\left(\left(\left(\left(x \cdot x\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right)\right) + \left(2 \cdot 0.0001789971\right) \cdot \left(\left(\left(\left(\left(\left(x \cdot x\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right)} \cdot x \]
    2. Add Preprocessing
    3. Taylor expanded in x around 0

      \[\leadsto \mathsf{*.f64}\left(\color{blue}{\left(1 + {x}^{2} \cdot \left(\frac{3321371254951887171}{12500000000000000000} \cdot {x}^{2} - \frac{833192009}{1250000000}\right)\right)}, x\right) \]
    4. Step-by-step derivation
      1. +-lowering-+.f64N/A

        \[\leadsto \mathsf{*.f64}\left(\mathsf{+.f64}\left(1, \left({x}^{2} \cdot \left(\frac{3321371254951887171}{12500000000000000000} \cdot {x}^{2} - \frac{833192009}{1250000000}\right)\right)\right), x\right) \]
      2. *-lowering-*.f64N/A

        \[\leadsto \mathsf{*.f64}\left(\mathsf{+.f64}\left(1, \mathsf{*.f64}\left(\left({x}^{2}\right), \left(\frac{3321371254951887171}{12500000000000000000} \cdot {x}^{2} - \frac{833192009}{1250000000}\right)\right)\right), x\right) \]
      3. unpow2N/A

        \[\leadsto \mathsf{*.f64}\left(\mathsf{+.f64}\left(1, \mathsf{*.f64}\left(\left(x \cdot x\right), \left(\frac{3321371254951887171}{12500000000000000000} \cdot {x}^{2} - \frac{833192009}{1250000000}\right)\right)\right), x\right) \]
      4. *-lowering-*.f64N/A

        \[\leadsto \mathsf{*.f64}\left(\mathsf{+.f64}\left(1, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \left(\frac{3321371254951887171}{12500000000000000000} \cdot {x}^{2} - \frac{833192009}{1250000000}\right)\right)\right), x\right) \]
      5. sub-negN/A

        \[\leadsto \mathsf{*.f64}\left(\mathsf{+.f64}\left(1, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \left(\frac{3321371254951887171}{12500000000000000000} \cdot {x}^{2} + \left(\mathsf{neg}\left(\frac{833192009}{1250000000}\right)\right)\right)\right)\right), x\right) \]
      6. metadata-evalN/A

        \[\leadsto \mathsf{*.f64}\left(\mathsf{+.f64}\left(1, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \left(\frac{3321371254951887171}{12500000000000000000} \cdot {x}^{2} + \frac{-833192009}{1250000000}\right)\right)\right), x\right) \]
      7. +-commutativeN/A

        \[\leadsto \mathsf{*.f64}\left(\mathsf{+.f64}\left(1, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \left(\frac{-833192009}{1250000000} + \frac{3321371254951887171}{12500000000000000000} \cdot {x}^{2}\right)\right)\right), x\right) \]
      8. +-lowering-+.f64N/A

        \[\leadsto \mathsf{*.f64}\left(\mathsf{+.f64}\left(1, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{+.f64}\left(\frac{-833192009}{1250000000}, \left(\frac{3321371254951887171}{12500000000000000000} \cdot {x}^{2}\right)\right)\right)\right), x\right) \]
      9. *-commutativeN/A

        \[\leadsto \mathsf{*.f64}\left(\mathsf{+.f64}\left(1, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{+.f64}\left(\frac{-833192009}{1250000000}, \left({x}^{2} \cdot \frac{3321371254951887171}{12500000000000000000}\right)\right)\right)\right), x\right) \]
      10. *-lowering-*.f64N/A

        \[\leadsto \mathsf{*.f64}\left(\mathsf{+.f64}\left(1, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{+.f64}\left(\frac{-833192009}{1250000000}, \mathsf{*.f64}\left(\left({x}^{2}\right), \frac{3321371254951887171}{12500000000000000000}\right)\right)\right)\right), x\right) \]
      11. unpow2N/A

        \[\leadsto \mathsf{*.f64}\left(\mathsf{+.f64}\left(1, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{+.f64}\left(\frac{-833192009}{1250000000}, \mathsf{*.f64}\left(\left(x \cdot x\right), \frac{3321371254951887171}{12500000000000000000}\right)\right)\right)\right), x\right) \]
      12. *-lowering-*.f6466.9%

        \[\leadsto \mathsf{*.f64}\left(\mathsf{+.f64}\left(1, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \mathsf{+.f64}\left(\frac{-833192009}{1250000000}, \mathsf{*.f64}\left(\mathsf{*.f64}\left(x, x\right), \frac{3321371254951887171}{12500000000000000000}\right)\right)\right)\right), x\right) \]
    5. Simplified66.9%

      \[\leadsto \color{blue}{\left(1 + \left(x \cdot x\right) \cdot \left(-0.6665536072 + \left(x \cdot x\right) \cdot 0.265709700396151\right)\right)} \cdot x \]

    if 1.1499999999999999 < x

    1. Initial program 5.0%

      \[\frac{\left(\left(\left(\left(1 + 0.1049934947 \cdot \left(x \cdot x\right)\right) + 0.0424060604 \cdot \left(\left(x \cdot x\right) \cdot \left(x \cdot x\right)\right)\right) + 0.0072644182 \cdot \left(\left(\left(x \cdot x\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right)\right) + 0.0005064034 \cdot \left(\left(\left(\left(x \cdot x\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right)\right) + 0.0001789971 \cdot \left(\left(\left(\left(\left(x \cdot x\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right)}{\left(\left(\left(\left(\left(1 + 0.7715471019 \cdot \left(x \cdot x\right)\right) + 0.2909738639 \cdot \left(\left(x \cdot x\right) \cdot \left(x \cdot x\right)\right)\right) + 0.0694555761 \cdot \left(\left(\left(x \cdot x\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right)\right) + 0.0140005442 \cdot \left(\left(\left(\left(x \cdot x\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right)\right) + 0.0008327945 \cdot \left(\left(\left(\left(\left(x \cdot x\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right)\right) + \left(2 \cdot 0.0001789971\right) \cdot \left(\left(\left(\left(\left(\left(x \cdot x\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right)} \cdot x \]
    2. Add Preprocessing
    3. Taylor expanded in x around inf

      \[\leadsto \color{blue}{\frac{\frac{1}{2} + \frac{600041}{2386628} \cdot \frac{1}{{x}^{2}}}{x}} \]
    4. Step-by-step derivation
      1. /-lowering-/.f64N/A

        \[\leadsto \mathsf{/.f64}\left(\left(\frac{1}{2} + \frac{600041}{2386628} \cdot \frac{1}{{x}^{2}}\right), \color{blue}{x}\right) \]
      2. +-lowering-+.f64N/A

        \[\leadsto \mathsf{/.f64}\left(\mathsf{+.f64}\left(\frac{1}{2}, \left(\frac{600041}{2386628} \cdot \frac{1}{{x}^{2}}\right)\right), x\right) \]
      3. associate-*r/N/A

        \[\leadsto \mathsf{/.f64}\left(\mathsf{+.f64}\left(\frac{1}{2}, \left(\frac{\frac{600041}{2386628} \cdot 1}{{x}^{2}}\right)\right), x\right) \]
      4. metadata-evalN/A

        \[\leadsto \mathsf{/.f64}\left(\mathsf{+.f64}\left(\frac{1}{2}, \left(\frac{\frac{600041}{2386628}}{{x}^{2}}\right)\right), x\right) \]
      5. unpow2N/A

        \[\leadsto \mathsf{/.f64}\left(\mathsf{+.f64}\left(\frac{1}{2}, \left(\frac{\frac{600041}{2386628}}{x \cdot x}\right)\right), x\right) \]
      6. associate-/r*N/A

        \[\leadsto \mathsf{/.f64}\left(\mathsf{+.f64}\left(\frac{1}{2}, \left(\frac{\frac{\frac{600041}{2386628}}{x}}{x}\right)\right), x\right) \]
      7. /-lowering-/.f64N/A

        \[\leadsto \mathsf{/.f64}\left(\mathsf{+.f64}\left(\frac{1}{2}, \mathsf{/.f64}\left(\left(\frac{\frac{600041}{2386628}}{x}\right), x\right)\right), x\right) \]
      8. /-lowering-/.f6499.9%

        \[\leadsto \mathsf{/.f64}\left(\mathsf{+.f64}\left(\frac{1}{2}, \mathsf{/.f64}\left(\mathsf{/.f64}\left(\frac{600041}{2386628}, x\right), x\right)\right), x\right) \]
    5. Simplified99.9%

      \[\leadsto \color{blue}{\frac{0.5 + \frac{\frac{0.2514179000665374}{x}}{x}}{x}} \]
    6. Step-by-step derivation
      1. clear-numN/A

        \[\leadsto \frac{1}{\color{blue}{\frac{x}{\frac{1}{2} + \frac{\frac{\frac{600041}{2386628}}{x}}{x}}}} \]
      2. /-lowering-/.f64N/A

        \[\leadsto \mathsf{/.f64}\left(1, \color{blue}{\left(\frac{x}{\frac{1}{2} + \frac{\frac{\frac{600041}{2386628}}{x}}{x}}\right)}\right) \]
      3. /-lowering-/.f64N/A

        \[\leadsto \mathsf{/.f64}\left(1, \mathsf{/.f64}\left(x, \color{blue}{\left(\frac{1}{2} + \frac{\frac{\frac{600041}{2386628}}{x}}{x}\right)}\right)\right) \]
      4. +-lowering-+.f64N/A

        \[\leadsto \mathsf{/.f64}\left(1, \mathsf{/.f64}\left(x, \mathsf{+.f64}\left(\frac{1}{2}, \color{blue}{\left(\frac{\frac{\frac{600041}{2386628}}{x}}{x}\right)}\right)\right)\right) \]
      5. associate-/l/N/A

        \[\leadsto \mathsf{/.f64}\left(1, \mathsf{/.f64}\left(x, \mathsf{+.f64}\left(\frac{1}{2}, \left(\frac{\frac{600041}{2386628}}{\color{blue}{x \cdot x}}\right)\right)\right)\right) \]
      6. /-lowering-/.f64N/A

        \[\leadsto \mathsf{/.f64}\left(1, \mathsf{/.f64}\left(x, \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{/.f64}\left(\frac{600041}{2386628}, \color{blue}{\left(x \cdot x\right)}\right)\right)\right)\right) \]
      7. *-lowering-*.f6499.9%

        \[\leadsto \mathsf{/.f64}\left(1, \mathsf{/.f64}\left(x, \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{/.f64}\left(\frac{600041}{2386628}, \mathsf{*.f64}\left(x, \color{blue}{x}\right)\right)\right)\right)\right) \]
    7. Applied egg-rr99.9%

      \[\leadsto \color{blue}{\frac{1}{\frac{x}{0.5 + \frac{0.2514179000665374}{x \cdot x}}}} \]
    8. Taylor expanded in x around inf

      \[\leadsto \mathsf{/.f64}\left(1, \color{blue}{\left(x \cdot \left(2 - \frac{600041}{596657} \cdot \frac{1}{{x}^{2}}\right)\right)}\right) \]
    9. Step-by-step derivation
      1. *-lowering-*.f64N/A

        \[\leadsto \mathsf{/.f64}\left(1, \mathsf{*.f64}\left(x, \color{blue}{\left(2 - \frac{600041}{596657} \cdot \frac{1}{{x}^{2}}\right)}\right)\right) \]
      2. --lowering--.f64N/A

        \[\leadsto \mathsf{/.f64}\left(1, \mathsf{*.f64}\left(x, \mathsf{\_.f64}\left(2, \color{blue}{\left(\frac{600041}{596657} \cdot \frac{1}{{x}^{2}}\right)}\right)\right)\right) \]
      3. associate-*r/N/A

        \[\leadsto \mathsf{/.f64}\left(1, \mathsf{*.f64}\left(x, \mathsf{\_.f64}\left(2, \left(\frac{\frac{600041}{596657} \cdot 1}{\color{blue}{{x}^{2}}}\right)\right)\right)\right) \]
      4. metadata-evalN/A

        \[\leadsto \mathsf{/.f64}\left(1, \mathsf{*.f64}\left(x, \mathsf{\_.f64}\left(2, \left(\frac{\frac{600041}{596657}}{{\color{blue}{x}}^{2}}\right)\right)\right)\right) \]
      5. /-lowering-/.f64N/A

        \[\leadsto \mathsf{/.f64}\left(1, \mathsf{*.f64}\left(x, \mathsf{\_.f64}\left(2, \mathsf{/.f64}\left(\frac{600041}{596657}, \color{blue}{\left({x}^{2}\right)}\right)\right)\right)\right) \]
      6. unpow2N/A

        \[\leadsto \mathsf{/.f64}\left(1, \mathsf{*.f64}\left(x, \mathsf{\_.f64}\left(2, \mathsf{/.f64}\left(\frac{600041}{596657}, \left(x \cdot \color{blue}{x}\right)\right)\right)\right)\right) \]
      7. *-lowering-*.f64100.0%

        \[\leadsto \mathsf{/.f64}\left(1, \mathsf{*.f64}\left(x, \mathsf{\_.f64}\left(2, \mathsf{/.f64}\left(\frac{600041}{596657}, \mathsf{*.f64}\left(x, \color{blue}{x}\right)\right)\right)\right)\right) \]
    10. Simplified100.0%

      \[\leadsto \frac{1}{\color{blue}{x \cdot \left(2 - \frac{1.0056716002661497}{x \cdot x}\right)}} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification74.5%

    \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq 1.15:\\ \;\;\;\;x \cdot \left(1 + \left(x \cdot x\right) \cdot \left(-0.6665536072 + \left(x \cdot x\right) \cdot 0.265709700396151\right)\right)\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{x \cdot \left(2 - \frac{1.0056716002661497}{x \cdot x}\right)}\\ \end{array} \]
  5. Add Preprocessing

Alternative 2: 99.5% accurate, 10.8× speedup?

\[\begin{array}{l} x\_m = \left|x\right| \\ x\_s = \mathsf{copysign}\left(1, x\right) \\ x\_s \cdot \begin{array}{l} \mathbf{if}\;x\_m \leq 1:\\ \;\;\;\;x\_m \cdot \left(1 + x\_m \cdot \left(x\_m \cdot -0.6665536072\right)\right)\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{x\_m \cdot \left(2 - \frac{1.0056716002661497}{x\_m \cdot x\_m}\right)}\\ \end{array} \end{array} \]
x\_m = (fabs.f64 x)
x\_s = (copysign.f64 #s(literal 1 binary64) x)
(FPCore (x_s x_m)
 :precision binary64
 (*
  x_s
  (if (<= x_m 1.0)
    (* x_m (+ 1.0 (* x_m (* x_m -0.6665536072))))
    (/ 1.0 (* x_m (- 2.0 (/ 1.0056716002661497 (* x_m 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 <= 1.0) {
		tmp = x_m * (1.0 + (x_m * (x_m * -0.6665536072)));
	} else {
		tmp = 1.0 / (x_m * (2.0 - (1.0056716002661497 / (x_m * 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 <= 1.0d0) then
        tmp = x_m * (1.0d0 + (x_m * (x_m * (-0.6665536072d0))))
    else
        tmp = 1.0d0 / (x_m * (2.0d0 - (1.0056716002661497d0 / (x_m * 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 <= 1.0) {
		tmp = x_m * (1.0 + (x_m * (x_m * -0.6665536072)));
	} else {
		tmp = 1.0 / (x_m * (2.0 - (1.0056716002661497 / (x_m * 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 <= 1.0:
		tmp = x_m * (1.0 + (x_m * (x_m * -0.6665536072)))
	else:
		tmp = 1.0 / (x_m * (2.0 - (1.0056716002661497 / (x_m * 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 <= 1.0)
		tmp = Float64(x_m * Float64(1.0 + Float64(x_m * Float64(x_m * -0.6665536072))));
	else
		tmp = Float64(1.0 / Float64(x_m * Float64(2.0 - Float64(1.0056716002661497 / Float64(x_m * 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 <= 1.0)
		tmp = x_m * (1.0 + (x_m * (x_m * -0.6665536072)));
	else
		tmp = 1.0 / (x_m * (2.0 - (1.0056716002661497 / (x_m * 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, 1.0], N[(x$95$m * N[(1.0 + N[(x$95$m * N[(x$95$m * -0.6665536072), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(1.0 / N[(x$95$m * N[(2.0 - N[(1.0056716002661497 / N[(x$95$m * x$95$m), $MachinePrecision]), $MachinePrecision]), $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 1:\\
\;\;\;\;x\_m \cdot \left(1 + x\_m \cdot \left(x\_m \cdot -0.6665536072\right)\right)\\

\mathbf{else}:\\
\;\;\;\;\frac{1}{x\_m \cdot \left(2 - \frac{1.0056716002661497}{x\_m \cdot x\_m}\right)}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if x < 1

    1. Initial program 68.5%

      \[\frac{\left(\left(\left(\left(1 + 0.1049934947 \cdot \left(x \cdot x\right)\right) + 0.0424060604 \cdot \left(\left(x \cdot x\right) \cdot \left(x \cdot x\right)\right)\right) + 0.0072644182 \cdot \left(\left(\left(x \cdot x\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right)\right) + 0.0005064034 \cdot \left(\left(\left(\left(x \cdot x\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right)\right) + 0.0001789971 \cdot \left(\left(\left(\left(\left(x \cdot x\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right)}{\left(\left(\left(\left(\left(1 + 0.7715471019 \cdot \left(x \cdot x\right)\right) + 0.2909738639 \cdot \left(\left(x \cdot x\right) \cdot \left(x \cdot x\right)\right)\right) + 0.0694555761 \cdot \left(\left(\left(x \cdot x\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right)\right) + 0.0140005442 \cdot \left(\left(\left(\left(x \cdot x\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right)\right) + 0.0008327945 \cdot \left(\left(\left(\left(\left(x \cdot x\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right)\right) + \left(2 \cdot 0.0001789971\right) \cdot \left(\left(\left(\left(\left(\left(x \cdot x\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right)} \cdot x \]
    2. Add Preprocessing
    3. Taylor expanded in x around 0

      \[\leadsto \mathsf{*.f64}\left(\color{blue}{\left(1 + \frac{-833192009}{1250000000} \cdot {x}^{2}\right)}, x\right) \]
    4. Step-by-step derivation
      1. +-lowering-+.f64N/A

        \[\leadsto \mathsf{*.f64}\left(\mathsf{+.f64}\left(1, \left(\frac{-833192009}{1250000000} \cdot {x}^{2}\right)\right), x\right) \]
      2. *-commutativeN/A

        \[\leadsto \mathsf{*.f64}\left(\mathsf{+.f64}\left(1, \left({x}^{2} \cdot \frac{-833192009}{1250000000}\right)\right), x\right) \]
      3. unpow2N/A

        \[\leadsto \mathsf{*.f64}\left(\mathsf{+.f64}\left(1, \left(\left(x \cdot x\right) \cdot \frac{-833192009}{1250000000}\right)\right), x\right) \]
      4. associate-*l*N/A

        \[\leadsto \mathsf{*.f64}\left(\mathsf{+.f64}\left(1, \left(x \cdot \left(x \cdot \frac{-833192009}{1250000000}\right)\right)\right), x\right) \]
      5. *-lowering-*.f64N/A

        \[\leadsto \mathsf{*.f64}\left(\mathsf{+.f64}\left(1, \mathsf{*.f64}\left(x, \left(x \cdot \frac{-833192009}{1250000000}\right)\right)\right), x\right) \]
      6. *-lowering-*.f6466.4%

        \[\leadsto \mathsf{*.f64}\left(\mathsf{+.f64}\left(1, \mathsf{*.f64}\left(x, \mathsf{*.f64}\left(x, \frac{-833192009}{1250000000}\right)\right)\right), x\right) \]
    5. Simplified66.4%

      \[\leadsto \color{blue}{\left(1 + x \cdot \left(x \cdot -0.6665536072\right)\right)} \cdot x \]

    if 1 < x

    1. Initial program 5.0%

      \[\frac{\left(\left(\left(\left(1 + 0.1049934947 \cdot \left(x \cdot x\right)\right) + 0.0424060604 \cdot \left(\left(x \cdot x\right) \cdot \left(x \cdot x\right)\right)\right) + 0.0072644182 \cdot \left(\left(\left(x \cdot x\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right)\right) + 0.0005064034 \cdot \left(\left(\left(\left(x \cdot x\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right)\right) + 0.0001789971 \cdot \left(\left(\left(\left(\left(x \cdot x\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right)}{\left(\left(\left(\left(\left(1 + 0.7715471019 \cdot \left(x \cdot x\right)\right) + 0.2909738639 \cdot \left(\left(x \cdot x\right) \cdot \left(x \cdot x\right)\right)\right) + 0.0694555761 \cdot \left(\left(\left(x \cdot x\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right)\right) + 0.0140005442 \cdot \left(\left(\left(\left(x \cdot x\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right)\right) + 0.0008327945 \cdot \left(\left(\left(\left(\left(x \cdot x\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right)\right) + \left(2 \cdot 0.0001789971\right) \cdot \left(\left(\left(\left(\left(\left(x \cdot x\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right)} \cdot x \]
    2. Add Preprocessing
    3. Taylor expanded in x around inf

      \[\leadsto \color{blue}{\frac{\frac{1}{2} + \frac{600041}{2386628} \cdot \frac{1}{{x}^{2}}}{x}} \]
    4. Step-by-step derivation
      1. /-lowering-/.f64N/A

        \[\leadsto \mathsf{/.f64}\left(\left(\frac{1}{2} + \frac{600041}{2386628} \cdot \frac{1}{{x}^{2}}\right), \color{blue}{x}\right) \]
      2. +-lowering-+.f64N/A

        \[\leadsto \mathsf{/.f64}\left(\mathsf{+.f64}\left(\frac{1}{2}, \left(\frac{600041}{2386628} \cdot \frac{1}{{x}^{2}}\right)\right), x\right) \]
      3. associate-*r/N/A

        \[\leadsto \mathsf{/.f64}\left(\mathsf{+.f64}\left(\frac{1}{2}, \left(\frac{\frac{600041}{2386628} \cdot 1}{{x}^{2}}\right)\right), x\right) \]
      4. metadata-evalN/A

        \[\leadsto \mathsf{/.f64}\left(\mathsf{+.f64}\left(\frac{1}{2}, \left(\frac{\frac{600041}{2386628}}{{x}^{2}}\right)\right), x\right) \]
      5. unpow2N/A

        \[\leadsto \mathsf{/.f64}\left(\mathsf{+.f64}\left(\frac{1}{2}, \left(\frac{\frac{600041}{2386628}}{x \cdot x}\right)\right), x\right) \]
      6. associate-/r*N/A

        \[\leadsto \mathsf{/.f64}\left(\mathsf{+.f64}\left(\frac{1}{2}, \left(\frac{\frac{\frac{600041}{2386628}}{x}}{x}\right)\right), x\right) \]
      7. /-lowering-/.f64N/A

        \[\leadsto \mathsf{/.f64}\left(\mathsf{+.f64}\left(\frac{1}{2}, \mathsf{/.f64}\left(\left(\frac{\frac{600041}{2386628}}{x}\right), x\right)\right), x\right) \]
      8. /-lowering-/.f6499.9%

        \[\leadsto \mathsf{/.f64}\left(\mathsf{+.f64}\left(\frac{1}{2}, \mathsf{/.f64}\left(\mathsf{/.f64}\left(\frac{600041}{2386628}, x\right), x\right)\right), x\right) \]
    5. Simplified99.9%

      \[\leadsto \color{blue}{\frac{0.5 + \frac{\frac{0.2514179000665374}{x}}{x}}{x}} \]
    6. Step-by-step derivation
      1. clear-numN/A

        \[\leadsto \frac{1}{\color{blue}{\frac{x}{\frac{1}{2} + \frac{\frac{\frac{600041}{2386628}}{x}}{x}}}} \]
      2. /-lowering-/.f64N/A

        \[\leadsto \mathsf{/.f64}\left(1, \color{blue}{\left(\frac{x}{\frac{1}{2} + \frac{\frac{\frac{600041}{2386628}}{x}}{x}}\right)}\right) \]
      3. /-lowering-/.f64N/A

        \[\leadsto \mathsf{/.f64}\left(1, \mathsf{/.f64}\left(x, \color{blue}{\left(\frac{1}{2} + \frac{\frac{\frac{600041}{2386628}}{x}}{x}\right)}\right)\right) \]
      4. +-lowering-+.f64N/A

        \[\leadsto \mathsf{/.f64}\left(1, \mathsf{/.f64}\left(x, \mathsf{+.f64}\left(\frac{1}{2}, \color{blue}{\left(\frac{\frac{\frac{600041}{2386628}}{x}}{x}\right)}\right)\right)\right) \]
      5. associate-/l/N/A

        \[\leadsto \mathsf{/.f64}\left(1, \mathsf{/.f64}\left(x, \mathsf{+.f64}\left(\frac{1}{2}, \left(\frac{\frac{600041}{2386628}}{\color{blue}{x \cdot x}}\right)\right)\right)\right) \]
      6. /-lowering-/.f64N/A

        \[\leadsto \mathsf{/.f64}\left(1, \mathsf{/.f64}\left(x, \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{/.f64}\left(\frac{600041}{2386628}, \color{blue}{\left(x \cdot x\right)}\right)\right)\right)\right) \]
      7. *-lowering-*.f6499.9%

        \[\leadsto \mathsf{/.f64}\left(1, \mathsf{/.f64}\left(x, \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{/.f64}\left(\frac{600041}{2386628}, \mathsf{*.f64}\left(x, \color{blue}{x}\right)\right)\right)\right)\right) \]
    7. Applied egg-rr99.9%

      \[\leadsto \color{blue}{\frac{1}{\frac{x}{0.5 + \frac{0.2514179000665374}{x \cdot x}}}} \]
    8. Taylor expanded in x around inf

      \[\leadsto \mathsf{/.f64}\left(1, \color{blue}{\left(x \cdot \left(2 - \frac{600041}{596657} \cdot \frac{1}{{x}^{2}}\right)\right)}\right) \]
    9. Step-by-step derivation
      1. *-lowering-*.f64N/A

        \[\leadsto \mathsf{/.f64}\left(1, \mathsf{*.f64}\left(x, \color{blue}{\left(2 - \frac{600041}{596657} \cdot \frac{1}{{x}^{2}}\right)}\right)\right) \]
      2. --lowering--.f64N/A

        \[\leadsto \mathsf{/.f64}\left(1, \mathsf{*.f64}\left(x, \mathsf{\_.f64}\left(2, \color{blue}{\left(\frac{600041}{596657} \cdot \frac{1}{{x}^{2}}\right)}\right)\right)\right) \]
      3. associate-*r/N/A

        \[\leadsto \mathsf{/.f64}\left(1, \mathsf{*.f64}\left(x, \mathsf{\_.f64}\left(2, \left(\frac{\frac{600041}{596657} \cdot 1}{\color{blue}{{x}^{2}}}\right)\right)\right)\right) \]
      4. metadata-evalN/A

        \[\leadsto \mathsf{/.f64}\left(1, \mathsf{*.f64}\left(x, \mathsf{\_.f64}\left(2, \left(\frac{\frac{600041}{596657}}{{\color{blue}{x}}^{2}}\right)\right)\right)\right) \]
      5. /-lowering-/.f64N/A

        \[\leadsto \mathsf{/.f64}\left(1, \mathsf{*.f64}\left(x, \mathsf{\_.f64}\left(2, \mathsf{/.f64}\left(\frac{600041}{596657}, \color{blue}{\left({x}^{2}\right)}\right)\right)\right)\right) \]
      6. unpow2N/A

        \[\leadsto \mathsf{/.f64}\left(1, \mathsf{*.f64}\left(x, \mathsf{\_.f64}\left(2, \mathsf{/.f64}\left(\frac{600041}{596657}, \left(x \cdot \color{blue}{x}\right)\right)\right)\right)\right) \]
      7. *-lowering-*.f64100.0%

        \[\leadsto \mathsf{/.f64}\left(1, \mathsf{*.f64}\left(x, \mathsf{\_.f64}\left(2, \mathsf{/.f64}\left(\frac{600041}{596657}, \mathsf{*.f64}\left(x, \color{blue}{x}\right)\right)\right)\right)\right) \]
    10. Simplified100.0%

      \[\leadsto \frac{1}{\color{blue}{x \cdot \left(2 - \frac{1.0056716002661497}{x \cdot x}\right)}} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification74.1%

    \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq 1:\\ \;\;\;\;x \cdot \left(1 + x \cdot \left(x \cdot -0.6665536072\right)\right)\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{x \cdot \left(2 - \frac{1.0056716002661497}{x \cdot x}\right)}\\ \end{array} \]
  5. Add Preprocessing

Alternative 3: 99.5% accurate, 12.3× speedup?

\[\begin{array}{l} x\_m = \left|x\right| \\ x\_s = \mathsf{copysign}\left(1, x\right) \\ x\_s \cdot \begin{array}{l} \mathbf{if}\;x\_m \leq 1:\\ \;\;\;\;x\_m \cdot \left(1 + x\_m \cdot \left(x\_m \cdot -0.6665536072\right)\right)\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{x\_m \cdot 2 + \frac{-1.0056716002661497}{x\_m}}\\ \end{array} \end{array} \]
x\_m = (fabs.f64 x)
x\_s = (copysign.f64 #s(literal 1 binary64) x)
(FPCore (x_s x_m)
 :precision binary64
 (*
  x_s
  (if (<= x_m 1.0)
    (* x_m (+ 1.0 (* x_m (* x_m -0.6665536072))))
    (/ 1.0 (+ (* x_m 2.0) (/ -1.0056716002661497 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 <= 1.0) {
		tmp = x_m * (1.0 + (x_m * (x_m * -0.6665536072)));
	} else {
		tmp = 1.0 / ((x_m * 2.0) + (-1.0056716002661497 / 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 <= 1.0d0) then
        tmp = x_m * (1.0d0 + (x_m * (x_m * (-0.6665536072d0))))
    else
        tmp = 1.0d0 / ((x_m * 2.0d0) + ((-1.0056716002661497d0) / 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 <= 1.0) {
		tmp = x_m * (1.0 + (x_m * (x_m * -0.6665536072)));
	} else {
		tmp = 1.0 / ((x_m * 2.0) + (-1.0056716002661497 / 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 <= 1.0:
		tmp = x_m * (1.0 + (x_m * (x_m * -0.6665536072)))
	else:
		tmp = 1.0 / ((x_m * 2.0) + (-1.0056716002661497 / 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 <= 1.0)
		tmp = Float64(x_m * Float64(1.0 + Float64(x_m * Float64(x_m * -0.6665536072))));
	else
		tmp = Float64(1.0 / Float64(Float64(x_m * 2.0) + Float64(-1.0056716002661497 / 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 <= 1.0)
		tmp = x_m * (1.0 + (x_m * (x_m * -0.6665536072)));
	else
		tmp = 1.0 / ((x_m * 2.0) + (-1.0056716002661497 / 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, 1.0], N[(x$95$m * N[(1.0 + N[(x$95$m * N[(x$95$m * -0.6665536072), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(1.0 / N[(N[(x$95$m * 2.0), $MachinePrecision] + N[(-1.0056716002661497 / x$95$m), $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 1:\\
\;\;\;\;x\_m \cdot \left(1 + x\_m \cdot \left(x\_m \cdot -0.6665536072\right)\right)\\

\mathbf{else}:\\
\;\;\;\;\frac{1}{x\_m \cdot 2 + \frac{-1.0056716002661497}{x\_m}}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if x < 1

    1. Initial program 68.5%

      \[\frac{\left(\left(\left(\left(1 + 0.1049934947 \cdot \left(x \cdot x\right)\right) + 0.0424060604 \cdot \left(\left(x \cdot x\right) \cdot \left(x \cdot x\right)\right)\right) + 0.0072644182 \cdot \left(\left(\left(x \cdot x\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right)\right) + 0.0005064034 \cdot \left(\left(\left(\left(x \cdot x\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right)\right) + 0.0001789971 \cdot \left(\left(\left(\left(\left(x \cdot x\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right)}{\left(\left(\left(\left(\left(1 + 0.7715471019 \cdot \left(x \cdot x\right)\right) + 0.2909738639 \cdot \left(\left(x \cdot x\right) \cdot \left(x \cdot x\right)\right)\right) + 0.0694555761 \cdot \left(\left(\left(x \cdot x\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right)\right) + 0.0140005442 \cdot \left(\left(\left(\left(x \cdot x\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right)\right) + 0.0008327945 \cdot \left(\left(\left(\left(\left(x \cdot x\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right)\right) + \left(2 \cdot 0.0001789971\right) \cdot \left(\left(\left(\left(\left(\left(x \cdot x\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right)} \cdot x \]
    2. Add Preprocessing
    3. Taylor expanded in x around 0

      \[\leadsto \mathsf{*.f64}\left(\color{blue}{\left(1 + \frac{-833192009}{1250000000} \cdot {x}^{2}\right)}, x\right) \]
    4. Step-by-step derivation
      1. +-lowering-+.f64N/A

        \[\leadsto \mathsf{*.f64}\left(\mathsf{+.f64}\left(1, \left(\frac{-833192009}{1250000000} \cdot {x}^{2}\right)\right), x\right) \]
      2. *-commutativeN/A

        \[\leadsto \mathsf{*.f64}\left(\mathsf{+.f64}\left(1, \left({x}^{2} \cdot \frac{-833192009}{1250000000}\right)\right), x\right) \]
      3. unpow2N/A

        \[\leadsto \mathsf{*.f64}\left(\mathsf{+.f64}\left(1, \left(\left(x \cdot x\right) \cdot \frac{-833192009}{1250000000}\right)\right), x\right) \]
      4. associate-*l*N/A

        \[\leadsto \mathsf{*.f64}\left(\mathsf{+.f64}\left(1, \left(x \cdot \left(x \cdot \frac{-833192009}{1250000000}\right)\right)\right), x\right) \]
      5. *-lowering-*.f64N/A

        \[\leadsto \mathsf{*.f64}\left(\mathsf{+.f64}\left(1, \mathsf{*.f64}\left(x, \left(x \cdot \frac{-833192009}{1250000000}\right)\right)\right), x\right) \]
      6. *-lowering-*.f6466.4%

        \[\leadsto \mathsf{*.f64}\left(\mathsf{+.f64}\left(1, \mathsf{*.f64}\left(x, \mathsf{*.f64}\left(x, \frac{-833192009}{1250000000}\right)\right)\right), x\right) \]
    5. Simplified66.4%

      \[\leadsto \color{blue}{\left(1 + x \cdot \left(x \cdot -0.6665536072\right)\right)} \cdot x \]

    if 1 < x

    1. Initial program 5.0%

      \[\frac{\left(\left(\left(\left(1 + 0.1049934947 \cdot \left(x \cdot x\right)\right) + 0.0424060604 \cdot \left(\left(x \cdot x\right) \cdot \left(x \cdot x\right)\right)\right) + 0.0072644182 \cdot \left(\left(\left(x \cdot x\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right)\right) + 0.0005064034 \cdot \left(\left(\left(\left(x \cdot x\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right)\right) + 0.0001789971 \cdot \left(\left(\left(\left(\left(x \cdot x\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right)}{\left(\left(\left(\left(\left(1 + 0.7715471019 \cdot \left(x \cdot x\right)\right) + 0.2909738639 \cdot \left(\left(x \cdot x\right) \cdot \left(x \cdot x\right)\right)\right) + 0.0694555761 \cdot \left(\left(\left(x \cdot x\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right)\right) + 0.0140005442 \cdot \left(\left(\left(\left(x \cdot x\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right)\right) + 0.0008327945 \cdot \left(\left(\left(\left(\left(x \cdot x\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right)\right) + \left(2 \cdot 0.0001789971\right) \cdot \left(\left(\left(\left(\left(\left(x \cdot x\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right)} \cdot x \]
    2. Add Preprocessing
    3. Taylor expanded in x around inf

      \[\leadsto \color{blue}{\frac{\frac{1}{2} + \frac{600041}{2386628} \cdot \frac{1}{{x}^{2}}}{x}} \]
    4. Step-by-step derivation
      1. /-lowering-/.f64N/A

        \[\leadsto \mathsf{/.f64}\left(\left(\frac{1}{2} + \frac{600041}{2386628} \cdot \frac{1}{{x}^{2}}\right), \color{blue}{x}\right) \]
      2. +-lowering-+.f64N/A

        \[\leadsto \mathsf{/.f64}\left(\mathsf{+.f64}\left(\frac{1}{2}, \left(\frac{600041}{2386628} \cdot \frac{1}{{x}^{2}}\right)\right), x\right) \]
      3. associate-*r/N/A

        \[\leadsto \mathsf{/.f64}\left(\mathsf{+.f64}\left(\frac{1}{2}, \left(\frac{\frac{600041}{2386628} \cdot 1}{{x}^{2}}\right)\right), x\right) \]
      4. metadata-evalN/A

        \[\leadsto \mathsf{/.f64}\left(\mathsf{+.f64}\left(\frac{1}{2}, \left(\frac{\frac{600041}{2386628}}{{x}^{2}}\right)\right), x\right) \]
      5. unpow2N/A

        \[\leadsto \mathsf{/.f64}\left(\mathsf{+.f64}\left(\frac{1}{2}, \left(\frac{\frac{600041}{2386628}}{x \cdot x}\right)\right), x\right) \]
      6. associate-/r*N/A

        \[\leadsto \mathsf{/.f64}\left(\mathsf{+.f64}\left(\frac{1}{2}, \left(\frac{\frac{\frac{600041}{2386628}}{x}}{x}\right)\right), x\right) \]
      7. /-lowering-/.f64N/A

        \[\leadsto \mathsf{/.f64}\left(\mathsf{+.f64}\left(\frac{1}{2}, \mathsf{/.f64}\left(\left(\frac{\frac{600041}{2386628}}{x}\right), x\right)\right), x\right) \]
      8. /-lowering-/.f6499.9%

        \[\leadsto \mathsf{/.f64}\left(\mathsf{+.f64}\left(\frac{1}{2}, \mathsf{/.f64}\left(\mathsf{/.f64}\left(\frac{600041}{2386628}, x\right), x\right)\right), x\right) \]
    5. Simplified99.9%

      \[\leadsto \color{blue}{\frac{0.5 + \frac{\frac{0.2514179000665374}{x}}{x}}{x}} \]
    6. Step-by-step derivation
      1. clear-numN/A

        \[\leadsto \frac{1}{\color{blue}{\frac{x}{\frac{1}{2} + \frac{\frac{\frac{600041}{2386628}}{x}}{x}}}} \]
      2. /-lowering-/.f64N/A

        \[\leadsto \mathsf{/.f64}\left(1, \color{blue}{\left(\frac{x}{\frac{1}{2} + \frac{\frac{\frac{600041}{2386628}}{x}}{x}}\right)}\right) \]
      3. /-lowering-/.f64N/A

        \[\leadsto \mathsf{/.f64}\left(1, \mathsf{/.f64}\left(x, \color{blue}{\left(\frac{1}{2} + \frac{\frac{\frac{600041}{2386628}}{x}}{x}\right)}\right)\right) \]
      4. +-lowering-+.f64N/A

        \[\leadsto \mathsf{/.f64}\left(1, \mathsf{/.f64}\left(x, \mathsf{+.f64}\left(\frac{1}{2}, \color{blue}{\left(\frac{\frac{\frac{600041}{2386628}}{x}}{x}\right)}\right)\right)\right) \]
      5. associate-/l/N/A

        \[\leadsto \mathsf{/.f64}\left(1, \mathsf{/.f64}\left(x, \mathsf{+.f64}\left(\frac{1}{2}, \left(\frac{\frac{600041}{2386628}}{\color{blue}{x \cdot x}}\right)\right)\right)\right) \]
      6. /-lowering-/.f64N/A

        \[\leadsto \mathsf{/.f64}\left(1, \mathsf{/.f64}\left(x, \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{/.f64}\left(\frac{600041}{2386628}, \color{blue}{\left(x \cdot x\right)}\right)\right)\right)\right) \]
      7. *-lowering-*.f6499.9%

        \[\leadsto \mathsf{/.f64}\left(1, \mathsf{/.f64}\left(x, \mathsf{+.f64}\left(\frac{1}{2}, \mathsf{/.f64}\left(\frac{600041}{2386628}, \mathsf{*.f64}\left(x, \color{blue}{x}\right)\right)\right)\right)\right) \]
    7. Applied egg-rr99.9%

      \[\leadsto \color{blue}{\frac{1}{\frac{x}{0.5 + \frac{0.2514179000665374}{x \cdot x}}}} \]
    8. Taylor expanded in x around inf

      \[\leadsto \mathsf{/.f64}\left(1, \color{blue}{\left(x \cdot \left(2 - \frac{600041}{596657} \cdot \frac{1}{{x}^{2}}\right)\right)}\right) \]
    9. Step-by-step derivation
      1. *-lowering-*.f64N/A

        \[\leadsto \mathsf{/.f64}\left(1, \mathsf{*.f64}\left(x, \color{blue}{\left(2 - \frac{600041}{596657} \cdot \frac{1}{{x}^{2}}\right)}\right)\right) \]
      2. --lowering--.f64N/A

        \[\leadsto \mathsf{/.f64}\left(1, \mathsf{*.f64}\left(x, \mathsf{\_.f64}\left(2, \color{blue}{\left(\frac{600041}{596657} \cdot \frac{1}{{x}^{2}}\right)}\right)\right)\right) \]
      3. associate-*r/N/A

        \[\leadsto \mathsf{/.f64}\left(1, \mathsf{*.f64}\left(x, \mathsf{\_.f64}\left(2, \left(\frac{\frac{600041}{596657} \cdot 1}{\color{blue}{{x}^{2}}}\right)\right)\right)\right) \]
      4. metadata-evalN/A

        \[\leadsto \mathsf{/.f64}\left(1, \mathsf{*.f64}\left(x, \mathsf{\_.f64}\left(2, \left(\frac{\frac{600041}{596657}}{{\color{blue}{x}}^{2}}\right)\right)\right)\right) \]
      5. /-lowering-/.f64N/A

        \[\leadsto \mathsf{/.f64}\left(1, \mathsf{*.f64}\left(x, \mathsf{\_.f64}\left(2, \mathsf{/.f64}\left(\frac{600041}{596657}, \color{blue}{\left({x}^{2}\right)}\right)\right)\right)\right) \]
      6. unpow2N/A

        \[\leadsto \mathsf{/.f64}\left(1, \mathsf{*.f64}\left(x, \mathsf{\_.f64}\left(2, \mathsf{/.f64}\left(\frac{600041}{596657}, \left(x \cdot \color{blue}{x}\right)\right)\right)\right)\right) \]
      7. *-lowering-*.f64100.0%

        \[\leadsto \mathsf{/.f64}\left(1, \mathsf{*.f64}\left(x, \mathsf{\_.f64}\left(2, \mathsf{/.f64}\left(\frac{600041}{596657}, \mathsf{*.f64}\left(x, \color{blue}{x}\right)\right)\right)\right)\right) \]
    10. Simplified100.0%

      \[\leadsto \frac{1}{\color{blue}{x \cdot \left(2 - \frac{1.0056716002661497}{x \cdot x}\right)}} \]
    11. Taylor expanded in x around 0

      \[\leadsto \mathsf{/.f64}\left(1, \color{blue}{\left(\frac{2 \cdot {x}^{2} - \frac{600041}{596657}}{x}\right)}\right) \]
    12. Step-by-step derivation
      1. div-subN/A

        \[\leadsto \mathsf{/.f64}\left(1, \left(\frac{2 \cdot {x}^{2}}{x} - \color{blue}{\frac{\frac{600041}{596657}}{x}}\right)\right) \]
      2. associate-/l*N/A

        \[\leadsto \mathsf{/.f64}\left(1, \left(2 \cdot \frac{{x}^{2}}{x} - \frac{\color{blue}{\frac{600041}{596657}}}{x}\right)\right) \]
      3. fmm-defN/A

        \[\leadsto \mathsf{/.f64}\left(1, \left(\mathsf{fma}\left(2, \color{blue}{\frac{{x}^{2}}{x}}, \mathsf{neg}\left(\frac{\frac{600041}{596657}}{x}\right)\right)\right)\right) \]
      4. unpow2N/A

        \[\leadsto \mathsf{/.f64}\left(1, \left(\mathsf{fma}\left(2, \frac{x \cdot x}{x}, \mathsf{neg}\left(\frac{\frac{600041}{596657}}{x}\right)\right)\right)\right) \]
      5. associate-*l/N/A

        \[\leadsto \mathsf{/.f64}\left(1, \left(\mathsf{fma}\left(2, \frac{x}{x} \cdot \color{blue}{x}, \mathsf{neg}\left(\frac{\frac{600041}{596657}}{x}\right)\right)\right)\right) \]
      6. *-inversesN/A

        \[\leadsto \mathsf{/.f64}\left(1, \left(\mathsf{fma}\left(2, 1 \cdot x, \mathsf{neg}\left(\frac{\frac{600041}{596657}}{x}\right)\right)\right)\right) \]
      7. *-lft-identityN/A

        \[\leadsto \mathsf{/.f64}\left(1, \left(\mathsf{fma}\left(2, x, \mathsf{neg}\left(\frac{\frac{600041}{596657}}{x}\right)\right)\right)\right) \]
      8. metadata-evalN/A

        \[\leadsto \mathsf{/.f64}\left(1, \left(\mathsf{fma}\left(2, x, \mathsf{neg}\left(\frac{1 \cdot \frac{600041}{596657}}{x}\right)\right)\right)\right) \]
      9. associate-*l/N/A

        \[\leadsto \mathsf{/.f64}\left(1, \left(\mathsf{fma}\left(2, x, \mathsf{neg}\left(\frac{1}{x} \cdot \frac{600041}{596657}\right)\right)\right)\right) \]
      10. rgt-mult-inverseN/A

        \[\leadsto \mathsf{/.f64}\left(1, \left(\mathsf{fma}\left(2, x, \mathsf{neg}\left(\frac{x \cdot \frac{1}{x}}{x} \cdot \frac{600041}{596657}\right)\right)\right)\right) \]
      11. associate-*r/N/A

        \[\leadsto \mathsf{/.f64}\left(1, \left(\mathsf{fma}\left(2, x, \mathsf{neg}\left(\left(x \cdot \frac{\frac{1}{x}}{x}\right) \cdot \frac{600041}{596657}\right)\right)\right)\right) \]
      12. associate-/r*N/A

        \[\leadsto \mathsf{/.f64}\left(1, \left(\mathsf{fma}\left(2, x, \mathsf{neg}\left(\left(x \cdot \frac{1}{x \cdot x}\right) \cdot \frac{600041}{596657}\right)\right)\right)\right) \]
      13. unpow2N/A

        \[\leadsto \mathsf{/.f64}\left(1, \left(\mathsf{fma}\left(2, x, \mathsf{neg}\left(\left(x \cdot \frac{1}{{x}^{2}}\right) \cdot \frac{600041}{596657}\right)\right)\right)\right) \]
      14. associate-*r*N/A

        \[\leadsto \mathsf{/.f64}\left(1, \left(\mathsf{fma}\left(2, x, \mathsf{neg}\left(x \cdot \left(\frac{1}{{x}^{2}} \cdot \frac{600041}{596657}\right)\right)\right)\right)\right) \]
      15. *-commutativeN/A

        \[\leadsto \mathsf{/.f64}\left(1, \left(\mathsf{fma}\left(2, x, \mathsf{neg}\left(x \cdot \left(\frac{600041}{596657} \cdot \frac{1}{{x}^{2}}\right)\right)\right)\right)\right) \]
      16. *-commutativeN/A

        \[\leadsto \mathsf{/.f64}\left(1, \left(\mathsf{fma}\left(2, x, \mathsf{neg}\left(\left(\frac{600041}{596657} \cdot \frac{1}{{x}^{2}}\right) \cdot x\right)\right)\right)\right) \]
      17. distribute-lft-neg-outN/A

        \[\leadsto \mathsf{/.f64}\left(1, \left(\mathsf{fma}\left(2, x, \left(\mathsf{neg}\left(\frac{600041}{596657} \cdot \frac{1}{{x}^{2}}\right)\right) \cdot x\right)\right)\right) \]
      18. fma-defineN/A

        \[\leadsto \mathsf{/.f64}\left(1, \left(2 \cdot x + \color{blue}{\left(\mathsf{neg}\left(\frac{600041}{596657} \cdot \frac{1}{{x}^{2}}\right)\right) \cdot x}\right)\right) \]
      19. +-lowering-+.f64N/A

        \[\leadsto \mathsf{/.f64}\left(1, \mathsf{+.f64}\left(\left(2 \cdot x\right), \color{blue}{\left(\left(\mathsf{neg}\left(\frac{600041}{596657} \cdot \frac{1}{{x}^{2}}\right)\right) \cdot x\right)}\right)\right) \]
    13. Simplified99.9%

      \[\leadsto \frac{1}{\color{blue}{x \cdot 2 + \frac{-1.0056716002661497}{x}}} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification74.1%

    \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq 1:\\ \;\;\;\;x \cdot \left(1 + x \cdot \left(x \cdot -0.6665536072\right)\right)\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{x \cdot 2 + \frac{-1.0056716002661497}{x}}\\ \end{array} \]
  5. Add Preprocessing

Alternative 4: 99.3% accurate, 12.3× speedup?

\[\begin{array}{l} x\_m = \left|x\right| \\ x\_s = \mathsf{copysign}\left(1, x\right) \\ x\_s \cdot \begin{array}{l} \mathbf{if}\;x\_m \leq 0.78:\\ \;\;\;\;x\_m \cdot \left(1 + x\_m \cdot \left(x\_m \cdot -0.6665536072\right)\right)\\ \mathbf{else}:\\ \;\;\;\;\frac{0.5}{x\_m}\\ \end{array} \end{array} \]
x\_m = (fabs.f64 x)
x\_s = (copysign.f64 #s(literal 1 binary64) x)
(FPCore (x_s x_m)
 :precision binary64
 (*
  x_s
  (if (<= x_m 0.78)
    (* x_m (+ 1.0 (* x_m (* x_m -0.6665536072))))
    (/ 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 <= 0.78) {
		tmp = x_m * (1.0 + (x_m * (x_m * -0.6665536072)));
	} 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 <= 0.78d0) then
        tmp = x_m * (1.0d0 + (x_m * (x_m * (-0.6665536072d0))))
    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 <= 0.78) {
		tmp = x_m * (1.0 + (x_m * (x_m * -0.6665536072)));
	} 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 <= 0.78:
		tmp = x_m * (1.0 + (x_m * (x_m * -0.6665536072)))
	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 <= 0.78)
		tmp = Float64(x_m * Float64(1.0 + Float64(x_m * Float64(x_m * -0.6665536072))));
	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 <= 0.78)
		tmp = x_m * (1.0 + (x_m * (x_m * -0.6665536072)));
	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, 0.78], N[(x$95$m * N[(1.0 + N[(x$95$m * N[(x$95$m * -0.6665536072), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], 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 0.78:\\
\;\;\;\;x\_m \cdot \left(1 + x\_m \cdot \left(x\_m \cdot -0.6665536072\right)\right)\\

\mathbf{else}:\\
\;\;\;\;\frac{0.5}{x\_m}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if x < 0.78000000000000003

    1. Initial program 68.5%

      \[\frac{\left(\left(\left(\left(1 + 0.1049934947 \cdot \left(x \cdot x\right)\right) + 0.0424060604 \cdot \left(\left(x \cdot x\right) \cdot \left(x \cdot x\right)\right)\right) + 0.0072644182 \cdot \left(\left(\left(x \cdot x\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right)\right) + 0.0005064034 \cdot \left(\left(\left(\left(x \cdot x\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right)\right) + 0.0001789971 \cdot \left(\left(\left(\left(\left(x \cdot x\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right)}{\left(\left(\left(\left(\left(1 + 0.7715471019 \cdot \left(x \cdot x\right)\right) + 0.2909738639 \cdot \left(\left(x \cdot x\right) \cdot \left(x \cdot x\right)\right)\right) + 0.0694555761 \cdot \left(\left(\left(x \cdot x\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right)\right) + 0.0140005442 \cdot \left(\left(\left(\left(x \cdot x\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right)\right) + 0.0008327945 \cdot \left(\left(\left(\left(\left(x \cdot x\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right)\right) + \left(2 \cdot 0.0001789971\right) \cdot \left(\left(\left(\left(\left(\left(x \cdot x\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right)} \cdot x \]
    2. Add Preprocessing
    3. Taylor expanded in x around 0

      \[\leadsto \mathsf{*.f64}\left(\color{blue}{\left(1 + \frac{-833192009}{1250000000} \cdot {x}^{2}\right)}, x\right) \]
    4. Step-by-step derivation
      1. +-lowering-+.f64N/A

        \[\leadsto \mathsf{*.f64}\left(\mathsf{+.f64}\left(1, \left(\frac{-833192009}{1250000000} \cdot {x}^{2}\right)\right), x\right) \]
      2. *-commutativeN/A

        \[\leadsto \mathsf{*.f64}\left(\mathsf{+.f64}\left(1, \left({x}^{2} \cdot \frac{-833192009}{1250000000}\right)\right), x\right) \]
      3. unpow2N/A

        \[\leadsto \mathsf{*.f64}\left(\mathsf{+.f64}\left(1, \left(\left(x \cdot x\right) \cdot \frac{-833192009}{1250000000}\right)\right), x\right) \]
      4. associate-*l*N/A

        \[\leadsto \mathsf{*.f64}\left(\mathsf{+.f64}\left(1, \left(x \cdot \left(x \cdot \frac{-833192009}{1250000000}\right)\right)\right), x\right) \]
      5. *-lowering-*.f64N/A

        \[\leadsto \mathsf{*.f64}\left(\mathsf{+.f64}\left(1, \mathsf{*.f64}\left(x, \left(x \cdot \frac{-833192009}{1250000000}\right)\right)\right), x\right) \]
      6. *-lowering-*.f6466.4%

        \[\leadsto \mathsf{*.f64}\left(\mathsf{+.f64}\left(1, \mathsf{*.f64}\left(x, \mathsf{*.f64}\left(x, \frac{-833192009}{1250000000}\right)\right)\right), x\right) \]
    5. Simplified66.4%

      \[\leadsto \color{blue}{\left(1 + x \cdot \left(x \cdot -0.6665536072\right)\right)} \cdot x \]

    if 0.78000000000000003 < x

    1. Initial program 5.0%

      \[\frac{\left(\left(\left(\left(1 + 0.1049934947 \cdot \left(x \cdot x\right)\right) + 0.0424060604 \cdot \left(\left(x \cdot x\right) \cdot \left(x \cdot x\right)\right)\right) + 0.0072644182 \cdot \left(\left(\left(x \cdot x\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right)\right) + 0.0005064034 \cdot \left(\left(\left(\left(x \cdot x\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right)\right) + 0.0001789971 \cdot \left(\left(\left(\left(\left(x \cdot x\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right)}{\left(\left(\left(\left(\left(1 + 0.7715471019 \cdot \left(x \cdot x\right)\right) + 0.2909738639 \cdot \left(\left(x \cdot x\right) \cdot \left(x \cdot x\right)\right)\right) + 0.0694555761 \cdot \left(\left(\left(x \cdot x\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right)\right) + 0.0140005442 \cdot \left(\left(\left(\left(x \cdot x\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right)\right) + 0.0008327945 \cdot \left(\left(\left(\left(\left(x \cdot x\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right)\right) + \left(2 \cdot 0.0001789971\right) \cdot \left(\left(\left(\left(\left(\left(x \cdot x\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right)} \cdot x \]
    2. Add Preprocessing
    3. Taylor expanded in x around inf

      \[\leadsto \color{blue}{\frac{\frac{1}{2}}{x}} \]
    4. Step-by-step derivation
      1. /-lowering-/.f6499.3%

        \[\leadsto \mathsf{/.f64}\left(\frac{1}{2}, \color{blue}{x}\right) \]
    5. Simplified99.3%

      \[\leadsto \color{blue}{\frac{0.5}{x}} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification73.9%

    \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq 0.78:\\ \;\;\;\;x \cdot \left(1 + x \cdot \left(x \cdot -0.6665536072\right)\right)\\ \mathbf{else}:\\ \;\;\;\;\frac{0.5}{x}\\ \end{array} \]
  5. Add Preprocessing

Alternative 5: 99.1% accurate, 21.6× speedup?

\[\begin{array}{l} x\_m = \left|x\right| \\ x\_s = \mathsf{copysign}\left(1, x\right) \\ x\_s \cdot \begin{array}{l} \mathbf{if}\;x\_m \leq 0.72:\\ \;\;\;\;x\_m\\ \mathbf{else}:\\ \;\;\;\;\frac{0.5}{x\_m}\\ \end{array} \end{array} \]
x\_m = (fabs.f64 x)
x\_s = (copysign.f64 #s(literal 1 binary64) x)
(FPCore (x_s x_m)
 :precision binary64
 (* x_s (if (<= x_m 0.72) 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 <= 0.72) {
		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 <= 0.72d0) 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 <= 0.72) {
		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 <= 0.72:
		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 <= 0.72)
		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 <= 0.72)
		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, 0.72], 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 0.72:\\
\;\;\;\;x\_m\\

\mathbf{else}:\\
\;\;\;\;\frac{0.5}{x\_m}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if x < 0.71999999999999997

    1. Initial program 68.5%

      \[\frac{\left(\left(\left(\left(1 + 0.1049934947 \cdot \left(x \cdot x\right)\right) + 0.0424060604 \cdot \left(\left(x \cdot x\right) \cdot \left(x \cdot x\right)\right)\right) + 0.0072644182 \cdot \left(\left(\left(x \cdot x\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right)\right) + 0.0005064034 \cdot \left(\left(\left(\left(x \cdot x\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right)\right) + 0.0001789971 \cdot \left(\left(\left(\left(\left(x \cdot x\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right)}{\left(\left(\left(\left(\left(1 + 0.7715471019 \cdot \left(x \cdot x\right)\right) + 0.2909738639 \cdot \left(\left(x \cdot x\right) \cdot \left(x \cdot x\right)\right)\right) + 0.0694555761 \cdot \left(\left(\left(x \cdot x\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right)\right) + 0.0140005442 \cdot \left(\left(\left(\left(x \cdot x\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right)\right) + 0.0008327945 \cdot \left(\left(\left(\left(\left(x \cdot x\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right)\right) + \left(2 \cdot 0.0001789971\right) \cdot \left(\left(\left(\left(\left(\left(x \cdot x\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right)} \cdot x \]
    2. Add Preprocessing
    3. Taylor expanded in x around 0

      \[\leadsto \color{blue}{x} \]
    4. Step-by-step derivation
      1. Simplified66.8%

        \[\leadsto \color{blue}{x} \]

      if 0.71999999999999997 < x

      1. Initial program 5.0%

        \[\frac{\left(\left(\left(\left(1 + 0.1049934947 \cdot \left(x \cdot x\right)\right) + 0.0424060604 \cdot \left(\left(x \cdot x\right) \cdot \left(x \cdot x\right)\right)\right) + 0.0072644182 \cdot \left(\left(\left(x \cdot x\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right)\right) + 0.0005064034 \cdot \left(\left(\left(\left(x \cdot x\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right)\right) + 0.0001789971 \cdot \left(\left(\left(\left(\left(x \cdot x\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right)}{\left(\left(\left(\left(\left(1 + 0.7715471019 \cdot \left(x \cdot x\right)\right) + 0.2909738639 \cdot \left(\left(x \cdot x\right) \cdot \left(x \cdot x\right)\right)\right) + 0.0694555761 \cdot \left(\left(\left(x \cdot x\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right)\right) + 0.0140005442 \cdot \left(\left(\left(\left(x \cdot x\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right)\right) + 0.0008327945 \cdot \left(\left(\left(\left(\left(x \cdot x\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right)\right) + \left(2 \cdot 0.0001789971\right) \cdot \left(\left(\left(\left(\left(\left(x \cdot x\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right)} \cdot x \]
      2. Add Preprocessing
      3. Taylor expanded in x around inf

        \[\leadsto \color{blue}{\frac{\frac{1}{2}}{x}} \]
      4. Step-by-step derivation
        1. /-lowering-/.f6499.3%

          \[\leadsto \mathsf{/.f64}\left(\frac{1}{2}, \color{blue}{x}\right) \]
      5. Simplified99.3%

        \[\leadsto \color{blue}{\frac{0.5}{x}} \]
    5. Recombined 2 regimes into one program.
    6. Add Preprocessing

    Alternative 6: 50.7% 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 #s(literal 1 binary64) 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
    1. Initial program 53.9%

      \[\frac{\left(\left(\left(\left(1 + 0.1049934947 \cdot \left(x \cdot x\right)\right) + 0.0424060604 \cdot \left(\left(x \cdot x\right) \cdot \left(x \cdot x\right)\right)\right) + 0.0072644182 \cdot \left(\left(\left(x \cdot x\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right)\right) + 0.0005064034 \cdot \left(\left(\left(\left(x \cdot x\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right)\right) + 0.0001789971 \cdot \left(\left(\left(\left(\left(x \cdot x\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right)}{\left(\left(\left(\left(\left(1 + 0.7715471019 \cdot \left(x \cdot x\right)\right) + 0.2909738639 \cdot \left(\left(x \cdot x\right) \cdot \left(x \cdot x\right)\right)\right) + 0.0694555761 \cdot \left(\left(\left(x \cdot x\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right)\right) + 0.0140005442 \cdot \left(\left(\left(\left(x \cdot x\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right)\right) + 0.0008327945 \cdot \left(\left(\left(\left(\left(x \cdot x\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right)\right) + \left(2 \cdot 0.0001789971\right) \cdot \left(\left(\left(\left(\left(\left(x \cdot x\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)\right)} \cdot x \]
    2. Add Preprocessing
    3. Taylor expanded in x around 0

      \[\leadsto \color{blue}{x} \]
    4. Step-by-step derivation
      1. Simplified52.3%

        \[\leadsto \color{blue}{x} \]
      2. Add Preprocessing

      Reproduce

      ?
      herbie shell --seed 2024155 
      (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))