Numeric.SpecFunctions:invErfc from math-functions-0.1.5.2, B

Percentage Accurate: 99.9% → 99.9%
Time: 6.0s
Alternatives: 10
Speedup: 1.0×

Specification

?
\[\begin{array}{l} \\ 0.70711 \cdot \left(\frac{2.30753 + x \cdot 0.27061}{1 + x \cdot \left(0.99229 + x \cdot 0.04481\right)} - x\right) \end{array} \]
(FPCore (x)
 :precision binary64
 (*
  0.70711
  (- (/ (+ 2.30753 (* x 0.27061)) (+ 1.0 (* x (+ 0.99229 (* x 0.04481))))) x)))
double code(double x) {
	return 0.70711 * (((2.30753 + (x * 0.27061)) / (1.0 + (x * (0.99229 + (x * 0.04481))))) - x);
}
real(8) function code(x)
    real(8), intent (in) :: x
    code = 0.70711d0 * (((2.30753d0 + (x * 0.27061d0)) / (1.0d0 + (x * (0.99229d0 + (x * 0.04481d0))))) - x)
end function
public static double code(double x) {
	return 0.70711 * (((2.30753 + (x * 0.27061)) / (1.0 + (x * (0.99229 + (x * 0.04481))))) - x);
}
def code(x):
	return 0.70711 * (((2.30753 + (x * 0.27061)) / (1.0 + (x * (0.99229 + (x * 0.04481))))) - x)
function code(x)
	return Float64(0.70711 * Float64(Float64(Float64(2.30753 + Float64(x * 0.27061)) / Float64(1.0 + Float64(x * Float64(0.99229 + Float64(x * 0.04481))))) - x))
end
function tmp = code(x)
	tmp = 0.70711 * (((2.30753 + (x * 0.27061)) / (1.0 + (x * (0.99229 + (x * 0.04481))))) - x);
end
code[x_] := N[(0.70711 * N[(N[(N[(2.30753 + N[(x * 0.27061), $MachinePrecision]), $MachinePrecision] / N[(1.0 + N[(x * N[(0.99229 + N[(x * 0.04481), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] - x), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
0.70711 \cdot \left(\frac{2.30753 + x \cdot 0.27061}{1 + x \cdot \left(0.99229 + x \cdot 0.04481\right)} - x\right)
\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 10 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: 99.9% accurate, 1.0× speedup?

\[\begin{array}{l} \\ 0.70711 \cdot \left(\frac{2.30753 + x \cdot 0.27061}{1 + x \cdot \left(0.99229 + x \cdot 0.04481\right)} - x\right) \end{array} \]
(FPCore (x)
 :precision binary64
 (*
  0.70711
  (- (/ (+ 2.30753 (* x 0.27061)) (+ 1.0 (* x (+ 0.99229 (* x 0.04481))))) x)))
double code(double x) {
	return 0.70711 * (((2.30753 + (x * 0.27061)) / (1.0 + (x * (0.99229 + (x * 0.04481))))) - x);
}
real(8) function code(x)
    real(8), intent (in) :: x
    code = 0.70711d0 * (((2.30753d0 + (x * 0.27061d0)) / (1.0d0 + (x * (0.99229d0 + (x * 0.04481d0))))) - x)
end function
public static double code(double x) {
	return 0.70711 * (((2.30753 + (x * 0.27061)) / (1.0 + (x * (0.99229 + (x * 0.04481))))) - x);
}
def code(x):
	return 0.70711 * (((2.30753 + (x * 0.27061)) / (1.0 + (x * (0.99229 + (x * 0.04481))))) - x)
function code(x)
	return Float64(0.70711 * Float64(Float64(Float64(2.30753 + Float64(x * 0.27061)) / Float64(1.0 + Float64(x * Float64(0.99229 + Float64(x * 0.04481))))) - x))
end
function tmp = code(x)
	tmp = 0.70711 * (((2.30753 + (x * 0.27061)) / (1.0 + (x * (0.99229 + (x * 0.04481))))) - x);
end
code[x_] := N[(0.70711 * N[(N[(N[(2.30753 + N[(x * 0.27061), $MachinePrecision]), $MachinePrecision] / N[(1.0 + N[(x * N[(0.99229 + N[(x * 0.04481), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] - x), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
0.70711 \cdot \left(\frac{2.30753 + x \cdot 0.27061}{1 + x \cdot \left(0.99229 + x \cdot 0.04481\right)} - x\right)
\end{array}

Alternative 1: 99.9% accurate, 1.0× speedup?

\[\begin{array}{l} \\ 0.70711 \cdot \left(\frac{2.30753 + x \cdot 0.27061}{1 + x \cdot \left(0.99229 + x \cdot 0.04481\right)} - x\right) \end{array} \]
(FPCore (x)
 :precision binary64
 (*
  0.70711
  (- (/ (+ 2.30753 (* x 0.27061)) (+ 1.0 (* x (+ 0.99229 (* x 0.04481))))) x)))
double code(double x) {
	return 0.70711 * (((2.30753 + (x * 0.27061)) / (1.0 + (x * (0.99229 + (x * 0.04481))))) - x);
}
real(8) function code(x)
    real(8), intent (in) :: x
    code = 0.70711d0 * (((2.30753d0 + (x * 0.27061d0)) / (1.0d0 + (x * (0.99229d0 + (x * 0.04481d0))))) - x)
end function
public static double code(double x) {
	return 0.70711 * (((2.30753 + (x * 0.27061)) / (1.0 + (x * (0.99229 + (x * 0.04481))))) - x);
}
def code(x):
	return 0.70711 * (((2.30753 + (x * 0.27061)) / (1.0 + (x * (0.99229 + (x * 0.04481))))) - x)
function code(x)
	return Float64(0.70711 * Float64(Float64(Float64(2.30753 + Float64(x * 0.27061)) / Float64(1.0 + Float64(x * Float64(0.99229 + Float64(x * 0.04481))))) - x))
end
function tmp = code(x)
	tmp = 0.70711 * (((2.30753 + (x * 0.27061)) / (1.0 + (x * (0.99229 + (x * 0.04481))))) - x);
end
code[x_] := N[(0.70711 * N[(N[(N[(2.30753 + N[(x * 0.27061), $MachinePrecision]), $MachinePrecision] / N[(1.0 + N[(x * N[(0.99229 + N[(x * 0.04481), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] - x), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
0.70711 \cdot \left(\frac{2.30753 + x \cdot 0.27061}{1 + x \cdot \left(0.99229 + x \cdot 0.04481\right)} - x\right)
\end{array}
Derivation
  1. Initial program 99.9%

    \[0.70711 \cdot \left(\frac{2.30753 + x \cdot 0.27061}{1 + x \cdot \left(0.99229 + x \cdot 0.04481\right)} - x\right) \]
  2. Final simplification99.9%

    \[\leadsto 0.70711 \cdot \left(\frac{2.30753 + x \cdot 0.27061}{1 + x \cdot \left(0.99229 + x \cdot 0.04481\right)} - x\right) \]

Alternative 2: 99.1% accurate, 1.1× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq -1.05 \lor \neg \left(x \leq 1.15\right):\\ \;\;\;\;\frac{4.2702753202410175}{x} + \left(x \cdot -0.70711 - \frac{58.14938538768042}{x \cdot x}\right)\\ \mathbf{else}:\\ \;\;\;\;0.70711 \cdot \left(\left(x \cdot x\right) \cdot 1.900161040244073 + \left(2.30753 + x \cdot -3.0191289437\right)\right)\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (if (or (<= x -1.05) (not (<= x 1.15)))
   (+
    (/ 4.2702753202410175 x)
    (- (* x -0.70711) (/ 58.14938538768042 (* x x))))
   (*
    0.70711
    (+ (* (* x x) 1.900161040244073) (+ 2.30753 (* x -3.0191289437))))))
double code(double x) {
	double tmp;
	if ((x <= -1.05) || !(x <= 1.15)) {
		tmp = (4.2702753202410175 / x) + ((x * -0.70711) - (58.14938538768042 / (x * x)));
	} else {
		tmp = 0.70711 * (((x * x) * 1.900161040244073) + (2.30753 + (x * -3.0191289437)));
	}
	return tmp;
}
real(8) function code(x)
    real(8), intent (in) :: x
    real(8) :: tmp
    if ((x <= (-1.05d0)) .or. (.not. (x <= 1.15d0))) then
        tmp = (4.2702753202410175d0 / x) + ((x * (-0.70711d0)) - (58.14938538768042d0 / (x * x)))
    else
        tmp = 0.70711d0 * (((x * x) * 1.900161040244073d0) + (2.30753d0 + (x * (-3.0191289437d0))))
    end if
    code = tmp
end function
public static double code(double x) {
	double tmp;
	if ((x <= -1.05) || !(x <= 1.15)) {
		tmp = (4.2702753202410175 / x) + ((x * -0.70711) - (58.14938538768042 / (x * x)));
	} else {
		tmp = 0.70711 * (((x * x) * 1.900161040244073) + (2.30753 + (x * -3.0191289437)));
	}
	return tmp;
}
def code(x):
	tmp = 0
	if (x <= -1.05) or not (x <= 1.15):
		tmp = (4.2702753202410175 / x) + ((x * -0.70711) - (58.14938538768042 / (x * x)))
	else:
		tmp = 0.70711 * (((x * x) * 1.900161040244073) + (2.30753 + (x * -3.0191289437)))
	return tmp
function code(x)
	tmp = 0.0
	if ((x <= -1.05) || !(x <= 1.15))
		tmp = Float64(Float64(4.2702753202410175 / x) + Float64(Float64(x * -0.70711) - Float64(58.14938538768042 / Float64(x * x))));
	else
		tmp = Float64(0.70711 * Float64(Float64(Float64(x * x) * 1.900161040244073) + Float64(2.30753 + Float64(x * -3.0191289437))));
	end
	return tmp
end
function tmp_2 = code(x)
	tmp = 0.0;
	if ((x <= -1.05) || ~((x <= 1.15)))
		tmp = (4.2702753202410175 / x) + ((x * -0.70711) - (58.14938538768042 / (x * x)));
	else
		tmp = 0.70711 * (((x * x) * 1.900161040244073) + (2.30753 + (x * -3.0191289437)));
	end
	tmp_2 = tmp;
end
code[x_] := If[Or[LessEqual[x, -1.05], N[Not[LessEqual[x, 1.15]], $MachinePrecision]], N[(N[(4.2702753202410175 / x), $MachinePrecision] + N[(N[(x * -0.70711), $MachinePrecision] - N[(58.14938538768042 / N[(x * x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(0.70711 * N[(N[(N[(x * x), $MachinePrecision] * 1.900161040244073), $MachinePrecision] + N[(2.30753 + N[(x * -3.0191289437), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;x \leq -1.05 \lor \neg \left(x \leq 1.15\right):\\
\;\;\;\;\frac{4.2702753202410175}{x} + \left(x \cdot -0.70711 - \frac{58.14938538768042}{x \cdot x}\right)\\

\mathbf{else}:\\
\;\;\;\;0.70711 \cdot \left(\left(x \cdot x\right) \cdot 1.900161040244073 + \left(2.30753 + x \cdot -3.0191289437\right)\right)\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if x < -1.05000000000000004 or 1.1499999999999999 < x

    1. Initial program 99.8%

      \[0.70711 \cdot \left(\frac{2.30753 + x \cdot 0.27061}{1 + x \cdot \left(0.99229 + x \cdot 0.04481\right)} - x\right) \]
    2. Step-by-step derivation
      1. sub-neg99.8%

        \[\leadsto 0.70711 \cdot \color{blue}{\left(\frac{2.30753 + x \cdot 0.27061}{1 + x \cdot \left(0.99229 + x \cdot 0.04481\right)} + \left(-x\right)\right)} \]
      2. +-commutative99.8%

        \[\leadsto 0.70711 \cdot \color{blue}{\left(\left(-x\right) + \frac{2.30753 + x \cdot 0.27061}{1 + x \cdot \left(0.99229 + x \cdot 0.04481\right)}\right)} \]
      3. distribute-rgt-in99.8%

        \[\leadsto \color{blue}{\left(-x\right) \cdot 0.70711 + \frac{2.30753 + x \cdot 0.27061}{1 + x \cdot \left(0.99229 + x \cdot 0.04481\right)} \cdot 0.70711} \]
      4. distribute-lft-neg-out99.8%

        \[\leadsto \color{blue}{\left(-x \cdot 0.70711\right)} + \frac{2.30753 + x \cdot 0.27061}{1 + x \cdot \left(0.99229 + x \cdot 0.04481\right)} \cdot 0.70711 \]
      5. distribute-rgt-neg-in99.8%

        \[\leadsto \color{blue}{x \cdot \left(-0.70711\right)} + \frac{2.30753 + x \cdot 0.27061}{1 + x \cdot \left(0.99229 + x \cdot 0.04481\right)} \cdot 0.70711 \]
      6. metadata-eval99.8%

        \[\leadsto x \cdot \color{blue}{-0.70711} + \frac{2.30753 + x \cdot 0.27061}{1 + x \cdot \left(0.99229 + x \cdot 0.04481\right)} \cdot 0.70711 \]
      7. metadata-eval99.8%

        \[\leadsto x \cdot \color{blue}{\left(0.70711 \cdot -1\right)} + \frac{2.30753 + x \cdot 0.27061}{1 + x \cdot \left(0.99229 + x \cdot 0.04481\right)} \cdot 0.70711 \]
      8. fma-def99.8%

        \[\leadsto \color{blue}{\mathsf{fma}\left(x, 0.70711 \cdot -1, \frac{2.30753 + x \cdot 0.27061}{1 + x \cdot \left(0.99229 + x \cdot 0.04481\right)} \cdot 0.70711\right)} \]
      9. metadata-eval99.8%

        \[\leadsto \mathsf{fma}\left(x, \color{blue}{-0.70711}, \frac{2.30753 + x \cdot 0.27061}{1 + x \cdot \left(0.99229 + x \cdot 0.04481\right)} \cdot 0.70711\right) \]
      10. associate-*l/99.8%

        \[\leadsto \mathsf{fma}\left(x, -0.70711, \color{blue}{\frac{\left(2.30753 + x \cdot 0.27061\right) \cdot 0.70711}{1 + x \cdot \left(0.99229 + x \cdot 0.04481\right)}}\right) \]
    3. Simplified99.8%

      \[\leadsto \color{blue}{\mathsf{fma}\left(x, -0.70711, \frac{\mathsf{fma}\left(x, 0.1913510371, 1.6316775383\right)}{\mathsf{fma}\left(x, \mathsf{fma}\left(x, 0.04481, 0.99229\right), 1\right)}\right)} \]
    4. Taylor expanded in x around inf 98.5%

      \[\leadsto \color{blue}{\left(4.2702753202410175 \cdot \frac{1}{x} + -0.70711 \cdot x\right) - 58.14938538768042 \cdot \frac{1}{{x}^{2}}} \]
    5. Step-by-step derivation
      1. associate--l+98.5%

        \[\leadsto \color{blue}{4.2702753202410175 \cdot \frac{1}{x} + \left(-0.70711 \cdot x - 58.14938538768042 \cdot \frac{1}{{x}^{2}}\right)} \]
      2. associate-*r/98.5%

        \[\leadsto \color{blue}{\frac{4.2702753202410175 \cdot 1}{x}} + \left(-0.70711 \cdot x - 58.14938538768042 \cdot \frac{1}{{x}^{2}}\right) \]
      3. metadata-eval98.5%

        \[\leadsto \frac{\color{blue}{4.2702753202410175}}{x} + \left(-0.70711 \cdot x - 58.14938538768042 \cdot \frac{1}{{x}^{2}}\right) \]
      4. *-commutative98.5%

        \[\leadsto \frac{4.2702753202410175}{x} + \left(\color{blue}{x \cdot -0.70711} - 58.14938538768042 \cdot \frac{1}{{x}^{2}}\right) \]
      5. unpow298.5%

        \[\leadsto \frac{4.2702753202410175}{x} + \left(x \cdot -0.70711 - 58.14938538768042 \cdot \frac{1}{\color{blue}{x \cdot x}}\right) \]
      6. associate-*r/98.5%

        \[\leadsto \frac{4.2702753202410175}{x} + \left(x \cdot -0.70711 - \color{blue}{\frac{58.14938538768042 \cdot 1}{x \cdot x}}\right) \]
      7. metadata-eval98.5%

        \[\leadsto \frac{4.2702753202410175}{x} + \left(x \cdot -0.70711 - \frac{\color{blue}{58.14938538768042}}{x \cdot x}\right) \]
    6. Simplified98.5%

      \[\leadsto \color{blue}{\frac{4.2702753202410175}{x} + \left(x \cdot -0.70711 - \frac{58.14938538768042}{x \cdot x}\right)} \]

    if -1.05000000000000004 < x < 1.1499999999999999

    1. Initial program 100.0%

      \[0.70711 \cdot \left(\frac{2.30753 + x \cdot 0.27061}{1 + x \cdot \left(0.99229 + x \cdot 0.04481\right)} - x\right) \]
    2. Taylor expanded in x around 0 99.5%

      \[\leadsto 0.70711 \cdot \left(\color{blue}{\left(1.900161040244073 \cdot {x}^{2} + \left(2.30753 + -2.0191289437 \cdot x\right)\right)} - x\right) \]
    3. Step-by-step derivation
      1. fma-def99.5%

        \[\leadsto 0.70711 \cdot \left(\color{blue}{\mathsf{fma}\left(1.900161040244073, {x}^{2}, 2.30753 + -2.0191289437 \cdot x\right)} - x\right) \]
      2. unpow299.5%

        \[\leadsto 0.70711 \cdot \left(\mathsf{fma}\left(1.900161040244073, \color{blue}{x \cdot x}, 2.30753 + -2.0191289437 \cdot x\right) - x\right) \]
    4. Simplified99.5%

      \[\leadsto 0.70711 \cdot \left(\color{blue}{\mathsf{fma}\left(1.900161040244073, x \cdot x, 2.30753 + -2.0191289437 \cdot x\right)} - x\right) \]
    5. Taylor expanded in x around 0 99.4%

      \[\leadsto 0.70711 \cdot \color{blue}{\left(1.900161040244073 \cdot {x}^{2} + \left(2.30753 + -3.0191289437 \cdot x\right)\right)} \]
    6. Step-by-step derivation
      1. fma-def99.4%

        \[\leadsto 0.70711 \cdot \color{blue}{\mathsf{fma}\left(1.900161040244073, {x}^{2}, 2.30753 + -3.0191289437 \cdot x\right)} \]
      2. unpow299.4%

        \[\leadsto 0.70711 \cdot \mathsf{fma}\left(1.900161040244073, \color{blue}{x \cdot x}, 2.30753 + -3.0191289437 \cdot x\right) \]
      3. *-commutative99.4%

        \[\leadsto 0.70711 \cdot \mathsf{fma}\left(1.900161040244073, x \cdot x, 2.30753 + \color{blue}{x \cdot -3.0191289437}\right) \]
    7. Simplified99.4%

      \[\leadsto 0.70711 \cdot \color{blue}{\mathsf{fma}\left(1.900161040244073, x \cdot x, 2.30753 + x \cdot -3.0191289437\right)} \]
    8. Step-by-step derivation
      1. fma-udef99.4%

        \[\leadsto 0.70711 \cdot \color{blue}{\left(1.900161040244073 \cdot \left(x \cdot x\right) + \left(2.30753 + x \cdot -3.0191289437\right)\right)} \]
    9. Applied egg-rr99.4%

      \[\leadsto 0.70711 \cdot \color{blue}{\left(1.900161040244073 \cdot \left(x \cdot x\right) + \left(2.30753 + x \cdot -3.0191289437\right)\right)} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification99.0%

    \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq -1.05 \lor \neg \left(x \leq 1.15\right):\\ \;\;\;\;\frac{4.2702753202410175}{x} + \left(x \cdot -0.70711 - \frac{58.14938538768042}{x \cdot x}\right)\\ \mathbf{else}:\\ \;\;\;\;0.70711 \cdot \left(\left(x \cdot x\right) \cdot 1.900161040244073 + \left(2.30753 + x \cdot -3.0191289437\right)\right)\\ \end{array} \]

Alternative 3: 99.0% accurate, 1.1× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq -1.05:\\ \;\;\;\;\frac{4.2702753202410175}{x} + x \cdot -0.70711\\ \mathbf{elif}\;x \leq 1.15:\\ \;\;\;\;0.70711 \cdot \left(\left(x \cdot x\right) \cdot 1.900161040244073 + \left(2.30753 + x \cdot -3.0191289437\right)\right)\\ \mathbf{else}:\\ \;\;\;\;x \cdot -0.70711\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (if (<= x -1.05)
   (+ (/ 4.2702753202410175 x) (* x -0.70711))
   (if (<= x 1.15)
     (*
      0.70711
      (+ (* (* x x) 1.900161040244073) (+ 2.30753 (* x -3.0191289437))))
     (* x -0.70711))))
double code(double x) {
	double tmp;
	if (x <= -1.05) {
		tmp = (4.2702753202410175 / x) + (x * -0.70711);
	} else if (x <= 1.15) {
		tmp = 0.70711 * (((x * x) * 1.900161040244073) + (2.30753 + (x * -3.0191289437)));
	} else {
		tmp = x * -0.70711;
	}
	return tmp;
}
real(8) function code(x)
    real(8), intent (in) :: x
    real(8) :: tmp
    if (x <= (-1.05d0)) then
        tmp = (4.2702753202410175d0 / x) + (x * (-0.70711d0))
    else if (x <= 1.15d0) then
        tmp = 0.70711d0 * (((x * x) * 1.900161040244073d0) + (2.30753d0 + (x * (-3.0191289437d0))))
    else
        tmp = x * (-0.70711d0)
    end if
    code = tmp
end function
public static double code(double x) {
	double tmp;
	if (x <= -1.05) {
		tmp = (4.2702753202410175 / x) + (x * -0.70711);
	} else if (x <= 1.15) {
		tmp = 0.70711 * (((x * x) * 1.900161040244073) + (2.30753 + (x * -3.0191289437)));
	} else {
		tmp = x * -0.70711;
	}
	return tmp;
}
def code(x):
	tmp = 0
	if x <= -1.05:
		tmp = (4.2702753202410175 / x) + (x * -0.70711)
	elif x <= 1.15:
		tmp = 0.70711 * (((x * x) * 1.900161040244073) + (2.30753 + (x * -3.0191289437)))
	else:
		tmp = x * -0.70711
	return tmp
function code(x)
	tmp = 0.0
	if (x <= -1.05)
		tmp = Float64(Float64(4.2702753202410175 / x) + Float64(x * -0.70711));
	elseif (x <= 1.15)
		tmp = Float64(0.70711 * Float64(Float64(Float64(x * x) * 1.900161040244073) + Float64(2.30753 + Float64(x * -3.0191289437))));
	else
		tmp = Float64(x * -0.70711);
	end
	return tmp
end
function tmp_2 = code(x)
	tmp = 0.0;
	if (x <= -1.05)
		tmp = (4.2702753202410175 / x) + (x * -0.70711);
	elseif (x <= 1.15)
		tmp = 0.70711 * (((x * x) * 1.900161040244073) + (2.30753 + (x * -3.0191289437)));
	else
		tmp = x * -0.70711;
	end
	tmp_2 = tmp;
end
code[x_] := If[LessEqual[x, -1.05], N[(N[(4.2702753202410175 / x), $MachinePrecision] + N[(x * -0.70711), $MachinePrecision]), $MachinePrecision], If[LessEqual[x, 1.15], N[(0.70711 * N[(N[(N[(x * x), $MachinePrecision] * 1.900161040244073), $MachinePrecision] + N[(2.30753 + N[(x * -3.0191289437), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(x * -0.70711), $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;x \leq -1.05:\\
\;\;\;\;\frac{4.2702753202410175}{x} + x \cdot -0.70711\\

\mathbf{elif}\;x \leq 1.15:\\
\;\;\;\;0.70711 \cdot \left(\left(x \cdot x\right) \cdot 1.900161040244073 + \left(2.30753 + x \cdot -3.0191289437\right)\right)\\

\mathbf{else}:\\
\;\;\;\;x \cdot -0.70711\\


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if x < -1.05000000000000004

    1. Initial program 99.9%

      \[0.70711 \cdot \left(\frac{2.30753 + x \cdot 0.27061}{1 + x \cdot \left(0.99229 + x \cdot 0.04481\right)} - x\right) \]
    2. Step-by-step derivation
      1. sub-neg99.9%

        \[\leadsto 0.70711 \cdot \color{blue}{\left(\frac{2.30753 + x \cdot 0.27061}{1 + x \cdot \left(0.99229 + x \cdot 0.04481\right)} + \left(-x\right)\right)} \]
      2. +-commutative99.9%

        \[\leadsto 0.70711 \cdot \color{blue}{\left(\left(-x\right) + \frac{2.30753 + x \cdot 0.27061}{1 + x \cdot \left(0.99229 + x \cdot 0.04481\right)}\right)} \]
      3. distribute-rgt-in99.9%

        \[\leadsto \color{blue}{\left(-x\right) \cdot 0.70711 + \frac{2.30753 + x \cdot 0.27061}{1 + x \cdot \left(0.99229 + x \cdot 0.04481\right)} \cdot 0.70711} \]
      4. distribute-lft-neg-out99.9%

        \[\leadsto \color{blue}{\left(-x \cdot 0.70711\right)} + \frac{2.30753 + x \cdot 0.27061}{1 + x \cdot \left(0.99229 + x \cdot 0.04481\right)} \cdot 0.70711 \]
      5. distribute-rgt-neg-in99.9%

        \[\leadsto \color{blue}{x \cdot \left(-0.70711\right)} + \frac{2.30753 + x \cdot 0.27061}{1 + x \cdot \left(0.99229 + x \cdot 0.04481\right)} \cdot 0.70711 \]
      6. metadata-eval99.9%

        \[\leadsto x \cdot \color{blue}{-0.70711} + \frac{2.30753 + x \cdot 0.27061}{1 + x \cdot \left(0.99229 + x \cdot 0.04481\right)} \cdot 0.70711 \]
      7. metadata-eval99.9%

        \[\leadsto x \cdot \color{blue}{\left(0.70711 \cdot -1\right)} + \frac{2.30753 + x \cdot 0.27061}{1 + x \cdot \left(0.99229 + x \cdot 0.04481\right)} \cdot 0.70711 \]
      8. fma-def99.9%

        \[\leadsto \color{blue}{\mathsf{fma}\left(x, 0.70711 \cdot -1, \frac{2.30753 + x \cdot 0.27061}{1 + x \cdot \left(0.99229 + x \cdot 0.04481\right)} \cdot 0.70711\right)} \]
      9. metadata-eval99.9%

        \[\leadsto \mathsf{fma}\left(x, \color{blue}{-0.70711}, \frac{2.30753 + x \cdot 0.27061}{1 + x \cdot \left(0.99229 + x \cdot 0.04481\right)} \cdot 0.70711\right) \]
      10. associate-*l/99.9%

        \[\leadsto \mathsf{fma}\left(x, -0.70711, \color{blue}{\frac{\left(2.30753 + x \cdot 0.27061\right) \cdot 0.70711}{1 + x \cdot \left(0.99229 + x \cdot 0.04481\right)}}\right) \]
    3. Simplified99.9%

      \[\leadsto \color{blue}{\mathsf{fma}\left(x, -0.70711, \frac{\mathsf{fma}\left(x, 0.1913510371, 1.6316775383\right)}{\mathsf{fma}\left(x, \mathsf{fma}\left(x, 0.04481, 0.99229\right), 1\right)}\right)} \]
    4. Taylor expanded in x around inf 99.4%

      \[\leadsto \color{blue}{4.2702753202410175 \cdot \frac{1}{x} + -0.70711 \cdot x} \]
    5. Step-by-step derivation
      1. associate-*r/99.4%

        \[\leadsto \color{blue}{\frac{4.2702753202410175 \cdot 1}{x}} + -0.70711 \cdot x \]
      2. metadata-eval99.4%

        \[\leadsto \frac{\color{blue}{4.2702753202410175}}{x} + -0.70711 \cdot x \]
      3. *-commutative99.4%

        \[\leadsto \frac{4.2702753202410175}{x} + \color{blue}{x \cdot -0.70711} \]
    6. Simplified99.4%

      \[\leadsto \color{blue}{\frac{4.2702753202410175}{x} + x \cdot -0.70711} \]

    if -1.05000000000000004 < x < 1.1499999999999999

    1. Initial program 100.0%

      \[0.70711 \cdot \left(\frac{2.30753 + x \cdot 0.27061}{1 + x \cdot \left(0.99229 + x \cdot 0.04481\right)} - x\right) \]
    2. Taylor expanded in x around 0 99.5%

      \[\leadsto 0.70711 \cdot \left(\color{blue}{\left(1.900161040244073 \cdot {x}^{2} + \left(2.30753 + -2.0191289437 \cdot x\right)\right)} - x\right) \]
    3. Step-by-step derivation
      1. fma-def99.5%

        \[\leadsto 0.70711 \cdot \left(\color{blue}{\mathsf{fma}\left(1.900161040244073, {x}^{2}, 2.30753 + -2.0191289437 \cdot x\right)} - x\right) \]
      2. unpow299.5%

        \[\leadsto 0.70711 \cdot \left(\mathsf{fma}\left(1.900161040244073, \color{blue}{x \cdot x}, 2.30753 + -2.0191289437 \cdot x\right) - x\right) \]
    4. Simplified99.5%

      \[\leadsto 0.70711 \cdot \left(\color{blue}{\mathsf{fma}\left(1.900161040244073, x \cdot x, 2.30753 + -2.0191289437 \cdot x\right)} - x\right) \]
    5. Taylor expanded in x around 0 99.4%

      \[\leadsto 0.70711 \cdot \color{blue}{\left(1.900161040244073 \cdot {x}^{2} + \left(2.30753 + -3.0191289437 \cdot x\right)\right)} \]
    6. Step-by-step derivation
      1. fma-def99.4%

        \[\leadsto 0.70711 \cdot \color{blue}{\mathsf{fma}\left(1.900161040244073, {x}^{2}, 2.30753 + -3.0191289437 \cdot x\right)} \]
      2. unpow299.4%

        \[\leadsto 0.70711 \cdot \mathsf{fma}\left(1.900161040244073, \color{blue}{x \cdot x}, 2.30753 + -3.0191289437 \cdot x\right) \]
      3. *-commutative99.4%

        \[\leadsto 0.70711 \cdot \mathsf{fma}\left(1.900161040244073, x \cdot x, 2.30753 + \color{blue}{x \cdot -3.0191289437}\right) \]
    7. Simplified99.4%

      \[\leadsto 0.70711 \cdot \color{blue}{\mathsf{fma}\left(1.900161040244073, x \cdot x, 2.30753 + x \cdot -3.0191289437\right)} \]
    8. Step-by-step derivation
      1. fma-udef99.4%

        \[\leadsto 0.70711 \cdot \color{blue}{\left(1.900161040244073 \cdot \left(x \cdot x\right) + \left(2.30753 + x \cdot -3.0191289437\right)\right)} \]
    9. Applied egg-rr99.4%

      \[\leadsto 0.70711 \cdot \color{blue}{\left(1.900161040244073 \cdot \left(x \cdot x\right) + \left(2.30753 + x \cdot -3.0191289437\right)\right)} \]

    if 1.1499999999999999 < x

    1. Initial program 99.7%

      \[0.70711 \cdot \left(\frac{2.30753 + x \cdot 0.27061}{1 + x \cdot \left(0.99229 + x \cdot 0.04481\right)} - x\right) \]
    2. Step-by-step derivation
      1. sub-neg99.7%

        \[\leadsto 0.70711 \cdot \color{blue}{\left(\frac{2.30753 + x \cdot 0.27061}{1 + x \cdot \left(0.99229 + x \cdot 0.04481\right)} + \left(-x\right)\right)} \]
      2. +-commutative99.7%

        \[\leadsto 0.70711 \cdot \color{blue}{\left(\left(-x\right) + \frac{2.30753 + x \cdot 0.27061}{1 + x \cdot \left(0.99229 + x \cdot 0.04481\right)}\right)} \]
      3. distribute-rgt-in99.7%

        \[\leadsto \color{blue}{\left(-x\right) \cdot 0.70711 + \frac{2.30753 + x \cdot 0.27061}{1 + x \cdot \left(0.99229 + x \cdot 0.04481\right)} \cdot 0.70711} \]
      4. distribute-lft-neg-out99.7%

        \[\leadsto \color{blue}{\left(-x \cdot 0.70711\right)} + \frac{2.30753 + x \cdot 0.27061}{1 + x \cdot \left(0.99229 + x \cdot 0.04481\right)} \cdot 0.70711 \]
      5. distribute-rgt-neg-in99.7%

        \[\leadsto \color{blue}{x \cdot \left(-0.70711\right)} + \frac{2.30753 + x \cdot 0.27061}{1 + x \cdot \left(0.99229 + x \cdot 0.04481\right)} \cdot 0.70711 \]
      6. metadata-eval99.7%

        \[\leadsto x \cdot \color{blue}{-0.70711} + \frac{2.30753 + x \cdot 0.27061}{1 + x \cdot \left(0.99229 + x \cdot 0.04481\right)} \cdot 0.70711 \]
      7. metadata-eval99.7%

        \[\leadsto x \cdot \color{blue}{\left(0.70711 \cdot -1\right)} + \frac{2.30753 + x \cdot 0.27061}{1 + x \cdot \left(0.99229 + x \cdot 0.04481\right)} \cdot 0.70711 \]
      8. fma-def99.7%

        \[\leadsto \color{blue}{\mathsf{fma}\left(x, 0.70711 \cdot -1, \frac{2.30753 + x \cdot 0.27061}{1 + x \cdot \left(0.99229 + x \cdot 0.04481\right)} \cdot 0.70711\right)} \]
      9. metadata-eval99.7%

        \[\leadsto \mathsf{fma}\left(x, \color{blue}{-0.70711}, \frac{2.30753 + x \cdot 0.27061}{1 + x \cdot \left(0.99229 + x \cdot 0.04481\right)} \cdot 0.70711\right) \]
      10. associate-*l/99.7%

        \[\leadsto \mathsf{fma}\left(x, -0.70711, \color{blue}{\frac{\left(2.30753 + x \cdot 0.27061\right) \cdot 0.70711}{1 + x \cdot \left(0.99229 + x \cdot 0.04481\right)}}\right) \]
    3. Simplified99.7%

      \[\leadsto \color{blue}{\mathsf{fma}\left(x, -0.70711, \frac{\mathsf{fma}\left(x, 0.1913510371, 1.6316775383\right)}{\mathsf{fma}\left(x, \mathsf{fma}\left(x, 0.04481, 0.99229\right), 1\right)}\right)} \]
    4. Taylor expanded in x around inf 97.5%

      \[\leadsto \color{blue}{-0.70711 \cdot x} \]
    5. Step-by-step derivation
      1. *-commutative97.5%

        \[\leadsto \color{blue}{x \cdot -0.70711} \]
    6. Simplified97.5%

      \[\leadsto \color{blue}{x \cdot -0.70711} \]
  3. Recombined 3 regimes into one program.
  4. Final simplification98.9%

    \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq -1.05:\\ \;\;\;\;\frac{4.2702753202410175}{x} + x \cdot -0.70711\\ \mathbf{elif}\;x \leq 1.15:\\ \;\;\;\;0.70711 \cdot \left(\left(x \cdot x\right) \cdot 1.900161040244073 + \left(2.30753 + x \cdot -3.0191289437\right)\right)\\ \mathbf{else}:\\ \;\;\;\;x \cdot -0.70711\\ \end{array} \]

Alternative 4: 98.5% accurate, 1.3× speedup?

\[\begin{array}{l} \\ 0.70711 \cdot \left(\frac{2.30753 + x \cdot 0.27061}{1 + x \cdot 0.99229} - x\right) \end{array} \]
(FPCore (x)
 :precision binary64
 (* 0.70711 (- (/ (+ 2.30753 (* x 0.27061)) (+ 1.0 (* x 0.99229))) x)))
double code(double x) {
	return 0.70711 * (((2.30753 + (x * 0.27061)) / (1.0 + (x * 0.99229))) - x);
}
real(8) function code(x)
    real(8), intent (in) :: x
    code = 0.70711d0 * (((2.30753d0 + (x * 0.27061d0)) / (1.0d0 + (x * 0.99229d0))) - x)
end function
public static double code(double x) {
	return 0.70711 * (((2.30753 + (x * 0.27061)) / (1.0 + (x * 0.99229))) - x);
}
def code(x):
	return 0.70711 * (((2.30753 + (x * 0.27061)) / (1.0 + (x * 0.99229))) - x)
function code(x)
	return Float64(0.70711 * Float64(Float64(Float64(2.30753 + Float64(x * 0.27061)) / Float64(1.0 + Float64(x * 0.99229))) - x))
end
function tmp = code(x)
	tmp = 0.70711 * (((2.30753 + (x * 0.27061)) / (1.0 + (x * 0.99229))) - x);
end
code[x_] := N[(0.70711 * N[(N[(N[(2.30753 + N[(x * 0.27061), $MachinePrecision]), $MachinePrecision] / N[(1.0 + N[(x * 0.99229), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] - x), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
0.70711 \cdot \left(\frac{2.30753 + x \cdot 0.27061}{1 + x \cdot 0.99229} - x\right)
\end{array}
Derivation
  1. Initial program 99.9%

    \[0.70711 \cdot \left(\frac{2.30753 + x \cdot 0.27061}{1 + x \cdot \left(0.99229 + x \cdot 0.04481\right)} - x\right) \]
  2. Taylor expanded in x around 0 98.2%

    \[\leadsto 0.70711 \cdot \left(\frac{2.30753 + x \cdot 0.27061}{1 + \color{blue}{0.99229 \cdot x}} - x\right) \]
  3. Step-by-step derivation
    1. *-commutative98.2%

      \[\leadsto 0.70711 \cdot \left(\frac{2.30753 + x \cdot 0.27061}{1 + \color{blue}{x \cdot 0.99229}} - x\right) \]
  4. Simplified98.2%

    \[\leadsto 0.70711 \cdot \left(\frac{2.30753 + x \cdot 0.27061}{1 + \color{blue}{x \cdot 0.99229}} - x\right) \]
  5. Final simplification98.2%

    \[\leadsto 0.70711 \cdot \left(\frac{2.30753 + x \cdot 0.27061}{1 + x \cdot 0.99229} - x\right) \]

Alternative 5: 98.9% accurate, 1.4× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq -1.05 \lor \neg \left(x \leq 2.8\right):\\ \;\;\;\;\frac{4.2702753202410175}{x} + x \cdot -0.70711\\ \mathbf{else}:\\ \;\;\;\;0.70711 \cdot \left(\left(2.30753 + x \cdot -2.0191289437\right) - x\right)\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (if (or (<= x -1.05) (not (<= x 2.8)))
   (+ (/ 4.2702753202410175 x) (* x -0.70711))
   (* 0.70711 (- (+ 2.30753 (* x -2.0191289437)) x))))
double code(double x) {
	double tmp;
	if ((x <= -1.05) || !(x <= 2.8)) {
		tmp = (4.2702753202410175 / x) + (x * -0.70711);
	} else {
		tmp = 0.70711 * ((2.30753 + (x * -2.0191289437)) - x);
	}
	return tmp;
}
real(8) function code(x)
    real(8), intent (in) :: x
    real(8) :: tmp
    if ((x <= (-1.05d0)) .or. (.not. (x <= 2.8d0))) then
        tmp = (4.2702753202410175d0 / x) + (x * (-0.70711d0))
    else
        tmp = 0.70711d0 * ((2.30753d0 + (x * (-2.0191289437d0))) - x)
    end if
    code = tmp
end function
public static double code(double x) {
	double tmp;
	if ((x <= -1.05) || !(x <= 2.8)) {
		tmp = (4.2702753202410175 / x) + (x * -0.70711);
	} else {
		tmp = 0.70711 * ((2.30753 + (x * -2.0191289437)) - x);
	}
	return tmp;
}
def code(x):
	tmp = 0
	if (x <= -1.05) or not (x <= 2.8):
		tmp = (4.2702753202410175 / x) + (x * -0.70711)
	else:
		tmp = 0.70711 * ((2.30753 + (x * -2.0191289437)) - x)
	return tmp
function code(x)
	tmp = 0.0
	if ((x <= -1.05) || !(x <= 2.8))
		tmp = Float64(Float64(4.2702753202410175 / x) + Float64(x * -0.70711));
	else
		tmp = Float64(0.70711 * Float64(Float64(2.30753 + Float64(x * -2.0191289437)) - x));
	end
	return tmp
end
function tmp_2 = code(x)
	tmp = 0.0;
	if ((x <= -1.05) || ~((x <= 2.8)))
		tmp = (4.2702753202410175 / x) + (x * -0.70711);
	else
		tmp = 0.70711 * ((2.30753 + (x * -2.0191289437)) - x);
	end
	tmp_2 = tmp;
end
code[x_] := If[Or[LessEqual[x, -1.05], N[Not[LessEqual[x, 2.8]], $MachinePrecision]], N[(N[(4.2702753202410175 / x), $MachinePrecision] + N[(x * -0.70711), $MachinePrecision]), $MachinePrecision], N[(0.70711 * N[(N[(2.30753 + N[(x * -2.0191289437), $MachinePrecision]), $MachinePrecision] - x), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;x \leq -1.05 \lor \neg \left(x \leq 2.8\right):\\
\;\;\;\;\frac{4.2702753202410175}{x} + x \cdot -0.70711\\

\mathbf{else}:\\
\;\;\;\;0.70711 \cdot \left(\left(2.30753 + x \cdot -2.0191289437\right) - x\right)\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if x < -1.05000000000000004 or 2.7999999999999998 < x

    1. Initial program 99.8%

      \[0.70711 \cdot \left(\frac{2.30753 + x \cdot 0.27061}{1 + x \cdot \left(0.99229 + x \cdot 0.04481\right)} - x\right) \]
    2. Step-by-step derivation
      1. sub-neg99.8%

        \[\leadsto 0.70711 \cdot \color{blue}{\left(\frac{2.30753 + x \cdot 0.27061}{1 + x \cdot \left(0.99229 + x \cdot 0.04481\right)} + \left(-x\right)\right)} \]
      2. +-commutative99.8%

        \[\leadsto 0.70711 \cdot \color{blue}{\left(\left(-x\right) + \frac{2.30753 + x \cdot 0.27061}{1 + x \cdot \left(0.99229 + x \cdot 0.04481\right)}\right)} \]
      3. distribute-rgt-in99.8%

        \[\leadsto \color{blue}{\left(-x\right) \cdot 0.70711 + \frac{2.30753 + x \cdot 0.27061}{1 + x \cdot \left(0.99229 + x \cdot 0.04481\right)} \cdot 0.70711} \]
      4. distribute-lft-neg-out99.8%

        \[\leadsto \color{blue}{\left(-x \cdot 0.70711\right)} + \frac{2.30753 + x \cdot 0.27061}{1 + x \cdot \left(0.99229 + x \cdot 0.04481\right)} \cdot 0.70711 \]
      5. distribute-rgt-neg-in99.8%

        \[\leadsto \color{blue}{x \cdot \left(-0.70711\right)} + \frac{2.30753 + x \cdot 0.27061}{1 + x \cdot \left(0.99229 + x \cdot 0.04481\right)} \cdot 0.70711 \]
      6. metadata-eval99.8%

        \[\leadsto x \cdot \color{blue}{-0.70711} + \frac{2.30753 + x \cdot 0.27061}{1 + x \cdot \left(0.99229 + x \cdot 0.04481\right)} \cdot 0.70711 \]
      7. metadata-eval99.8%

        \[\leadsto x \cdot \color{blue}{\left(0.70711 \cdot -1\right)} + \frac{2.30753 + x \cdot 0.27061}{1 + x \cdot \left(0.99229 + x \cdot 0.04481\right)} \cdot 0.70711 \]
      8. fma-def99.8%

        \[\leadsto \color{blue}{\mathsf{fma}\left(x, 0.70711 \cdot -1, \frac{2.30753 + x \cdot 0.27061}{1 + x \cdot \left(0.99229 + x \cdot 0.04481\right)} \cdot 0.70711\right)} \]
      9. metadata-eval99.8%

        \[\leadsto \mathsf{fma}\left(x, \color{blue}{-0.70711}, \frac{2.30753 + x \cdot 0.27061}{1 + x \cdot \left(0.99229 + x \cdot 0.04481\right)} \cdot 0.70711\right) \]
      10. associate-*l/99.8%

        \[\leadsto \mathsf{fma}\left(x, -0.70711, \color{blue}{\frac{\left(2.30753 + x \cdot 0.27061\right) \cdot 0.70711}{1 + x \cdot \left(0.99229 + x \cdot 0.04481\right)}}\right) \]
    3. Simplified99.8%

      \[\leadsto \color{blue}{\mathsf{fma}\left(x, -0.70711, \frac{\mathsf{fma}\left(x, 0.1913510371, 1.6316775383\right)}{\mathsf{fma}\left(x, \mathsf{fma}\left(x, 0.04481, 0.99229\right), 1\right)}\right)} \]
    4. Taylor expanded in x around inf 99.0%

      \[\leadsto \color{blue}{4.2702753202410175 \cdot \frac{1}{x} + -0.70711 \cdot x} \]
    5. Step-by-step derivation
      1. associate-*r/99.0%

        \[\leadsto \color{blue}{\frac{4.2702753202410175 \cdot 1}{x}} + -0.70711 \cdot x \]
      2. metadata-eval99.0%

        \[\leadsto \frac{\color{blue}{4.2702753202410175}}{x} + -0.70711 \cdot x \]
      3. *-commutative99.0%

        \[\leadsto \frac{4.2702753202410175}{x} + \color{blue}{x \cdot -0.70711} \]
    6. Simplified99.0%

      \[\leadsto \color{blue}{\frac{4.2702753202410175}{x} + x \cdot -0.70711} \]

    if -1.05000000000000004 < x < 2.7999999999999998

    1. Initial program 100.0%

      \[0.70711 \cdot \left(\frac{2.30753 + x \cdot 0.27061}{1 + x \cdot \left(0.99229 + x \cdot 0.04481\right)} - x\right) \]
    2. Taylor expanded in x around 0 98.4%

      \[\leadsto 0.70711 \cdot \left(\color{blue}{\left(2.30753 + -2.0191289437 \cdot x\right)} - x\right) \]
  3. Recombined 2 regimes into one program.
  4. Final simplification98.7%

    \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq -1.05 \lor \neg \left(x \leq 2.8\right):\\ \;\;\;\;\frac{4.2702753202410175}{x} + x \cdot -0.70711\\ \mathbf{else}:\\ \;\;\;\;0.70711 \cdot \left(\left(2.30753 + x \cdot -2.0191289437\right) - x\right)\\ \end{array} \]

Alternative 6: 98.9% accurate, 1.7× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq -1.05 \lor \neg \left(x \leq 2.8\right):\\ \;\;\;\;\frac{4.2702753202410175}{x} + x \cdot -0.70711\\ \mathbf{else}:\\ \;\;\;\;x \cdot -2.134856267379707 + 1.6316775383\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (if (or (<= x -1.05) (not (<= x 2.8)))
   (+ (/ 4.2702753202410175 x) (* x -0.70711))
   (+ (* x -2.134856267379707) 1.6316775383)))
double code(double x) {
	double tmp;
	if ((x <= -1.05) || !(x <= 2.8)) {
		tmp = (4.2702753202410175 / x) + (x * -0.70711);
	} else {
		tmp = (x * -2.134856267379707) + 1.6316775383;
	}
	return tmp;
}
real(8) function code(x)
    real(8), intent (in) :: x
    real(8) :: tmp
    if ((x <= (-1.05d0)) .or. (.not. (x <= 2.8d0))) then
        tmp = (4.2702753202410175d0 / x) + (x * (-0.70711d0))
    else
        tmp = (x * (-2.134856267379707d0)) + 1.6316775383d0
    end if
    code = tmp
end function
public static double code(double x) {
	double tmp;
	if ((x <= -1.05) || !(x <= 2.8)) {
		tmp = (4.2702753202410175 / x) + (x * -0.70711);
	} else {
		tmp = (x * -2.134856267379707) + 1.6316775383;
	}
	return tmp;
}
def code(x):
	tmp = 0
	if (x <= -1.05) or not (x <= 2.8):
		tmp = (4.2702753202410175 / x) + (x * -0.70711)
	else:
		tmp = (x * -2.134856267379707) + 1.6316775383
	return tmp
function code(x)
	tmp = 0.0
	if ((x <= -1.05) || !(x <= 2.8))
		tmp = Float64(Float64(4.2702753202410175 / x) + Float64(x * -0.70711));
	else
		tmp = Float64(Float64(x * -2.134856267379707) + 1.6316775383);
	end
	return tmp
end
function tmp_2 = code(x)
	tmp = 0.0;
	if ((x <= -1.05) || ~((x <= 2.8)))
		tmp = (4.2702753202410175 / x) + (x * -0.70711);
	else
		tmp = (x * -2.134856267379707) + 1.6316775383;
	end
	tmp_2 = tmp;
end
code[x_] := If[Or[LessEqual[x, -1.05], N[Not[LessEqual[x, 2.8]], $MachinePrecision]], N[(N[(4.2702753202410175 / x), $MachinePrecision] + N[(x * -0.70711), $MachinePrecision]), $MachinePrecision], N[(N[(x * -2.134856267379707), $MachinePrecision] + 1.6316775383), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;x \leq -1.05 \lor \neg \left(x \leq 2.8\right):\\
\;\;\;\;\frac{4.2702753202410175}{x} + x \cdot -0.70711\\

\mathbf{else}:\\
\;\;\;\;x \cdot -2.134856267379707 + 1.6316775383\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if x < -1.05000000000000004 or 2.7999999999999998 < x

    1. Initial program 99.8%

      \[0.70711 \cdot \left(\frac{2.30753 + x \cdot 0.27061}{1 + x \cdot \left(0.99229 + x \cdot 0.04481\right)} - x\right) \]
    2. Step-by-step derivation
      1. sub-neg99.8%

        \[\leadsto 0.70711 \cdot \color{blue}{\left(\frac{2.30753 + x \cdot 0.27061}{1 + x \cdot \left(0.99229 + x \cdot 0.04481\right)} + \left(-x\right)\right)} \]
      2. +-commutative99.8%

        \[\leadsto 0.70711 \cdot \color{blue}{\left(\left(-x\right) + \frac{2.30753 + x \cdot 0.27061}{1 + x \cdot \left(0.99229 + x \cdot 0.04481\right)}\right)} \]
      3. distribute-rgt-in99.8%

        \[\leadsto \color{blue}{\left(-x\right) \cdot 0.70711 + \frac{2.30753 + x \cdot 0.27061}{1 + x \cdot \left(0.99229 + x \cdot 0.04481\right)} \cdot 0.70711} \]
      4. distribute-lft-neg-out99.8%

        \[\leadsto \color{blue}{\left(-x \cdot 0.70711\right)} + \frac{2.30753 + x \cdot 0.27061}{1 + x \cdot \left(0.99229 + x \cdot 0.04481\right)} \cdot 0.70711 \]
      5. distribute-rgt-neg-in99.8%

        \[\leadsto \color{blue}{x \cdot \left(-0.70711\right)} + \frac{2.30753 + x \cdot 0.27061}{1 + x \cdot \left(0.99229 + x \cdot 0.04481\right)} \cdot 0.70711 \]
      6. metadata-eval99.8%

        \[\leadsto x \cdot \color{blue}{-0.70711} + \frac{2.30753 + x \cdot 0.27061}{1 + x \cdot \left(0.99229 + x \cdot 0.04481\right)} \cdot 0.70711 \]
      7. metadata-eval99.8%

        \[\leadsto x \cdot \color{blue}{\left(0.70711 \cdot -1\right)} + \frac{2.30753 + x \cdot 0.27061}{1 + x \cdot \left(0.99229 + x \cdot 0.04481\right)} \cdot 0.70711 \]
      8. fma-def99.8%

        \[\leadsto \color{blue}{\mathsf{fma}\left(x, 0.70711 \cdot -1, \frac{2.30753 + x \cdot 0.27061}{1 + x \cdot \left(0.99229 + x \cdot 0.04481\right)} \cdot 0.70711\right)} \]
      9. metadata-eval99.8%

        \[\leadsto \mathsf{fma}\left(x, \color{blue}{-0.70711}, \frac{2.30753 + x \cdot 0.27061}{1 + x \cdot \left(0.99229 + x \cdot 0.04481\right)} \cdot 0.70711\right) \]
      10. associate-*l/99.8%

        \[\leadsto \mathsf{fma}\left(x, -0.70711, \color{blue}{\frac{\left(2.30753 + x \cdot 0.27061\right) \cdot 0.70711}{1 + x \cdot \left(0.99229 + x \cdot 0.04481\right)}}\right) \]
    3. Simplified99.8%

      \[\leadsto \color{blue}{\mathsf{fma}\left(x, -0.70711, \frac{\mathsf{fma}\left(x, 0.1913510371, 1.6316775383\right)}{\mathsf{fma}\left(x, \mathsf{fma}\left(x, 0.04481, 0.99229\right), 1\right)}\right)} \]
    4. Taylor expanded in x around inf 99.0%

      \[\leadsto \color{blue}{4.2702753202410175 \cdot \frac{1}{x} + -0.70711 \cdot x} \]
    5. Step-by-step derivation
      1. associate-*r/99.0%

        \[\leadsto \color{blue}{\frac{4.2702753202410175 \cdot 1}{x}} + -0.70711 \cdot x \]
      2. metadata-eval99.0%

        \[\leadsto \frac{\color{blue}{4.2702753202410175}}{x} + -0.70711 \cdot x \]
      3. *-commutative99.0%

        \[\leadsto \frac{4.2702753202410175}{x} + \color{blue}{x \cdot -0.70711} \]
    6. Simplified99.0%

      \[\leadsto \color{blue}{\frac{4.2702753202410175}{x} + x \cdot -0.70711} \]

    if -1.05000000000000004 < x < 2.7999999999999998

    1. Initial program 100.0%

      \[0.70711 \cdot \left(\frac{2.30753 + x \cdot 0.27061}{1 + x \cdot \left(0.99229 + x \cdot 0.04481\right)} - x\right) \]
    2. Step-by-step derivation
      1. sub-neg100.0%

        \[\leadsto 0.70711 \cdot \color{blue}{\left(\frac{2.30753 + x \cdot 0.27061}{1 + x \cdot \left(0.99229 + x \cdot 0.04481\right)} + \left(-x\right)\right)} \]
      2. +-commutative100.0%

        \[\leadsto 0.70711 \cdot \color{blue}{\left(\left(-x\right) + \frac{2.30753 + x \cdot 0.27061}{1 + x \cdot \left(0.99229 + x \cdot 0.04481\right)}\right)} \]
      3. distribute-rgt-in99.9%

        \[\leadsto \color{blue}{\left(-x\right) \cdot 0.70711 + \frac{2.30753 + x \cdot 0.27061}{1 + x \cdot \left(0.99229 + x \cdot 0.04481\right)} \cdot 0.70711} \]
      4. distribute-lft-neg-out99.9%

        \[\leadsto \color{blue}{\left(-x \cdot 0.70711\right)} + \frac{2.30753 + x \cdot 0.27061}{1 + x \cdot \left(0.99229 + x \cdot 0.04481\right)} \cdot 0.70711 \]
      5. distribute-rgt-neg-in99.9%

        \[\leadsto \color{blue}{x \cdot \left(-0.70711\right)} + \frac{2.30753 + x \cdot 0.27061}{1 + x \cdot \left(0.99229 + x \cdot 0.04481\right)} \cdot 0.70711 \]
      6. metadata-eval99.9%

        \[\leadsto x \cdot \color{blue}{-0.70711} + \frac{2.30753 + x \cdot 0.27061}{1 + x \cdot \left(0.99229 + x \cdot 0.04481\right)} \cdot 0.70711 \]
      7. metadata-eval99.9%

        \[\leadsto x \cdot \color{blue}{\left(0.70711 \cdot -1\right)} + \frac{2.30753 + x \cdot 0.27061}{1 + x \cdot \left(0.99229 + x \cdot 0.04481\right)} \cdot 0.70711 \]
      8. fma-def99.9%

        \[\leadsto \color{blue}{\mathsf{fma}\left(x, 0.70711 \cdot -1, \frac{2.30753 + x \cdot 0.27061}{1 + x \cdot \left(0.99229 + x \cdot 0.04481\right)} \cdot 0.70711\right)} \]
      9. metadata-eval99.9%

        \[\leadsto \mathsf{fma}\left(x, \color{blue}{-0.70711}, \frac{2.30753 + x \cdot 0.27061}{1 + x \cdot \left(0.99229 + x \cdot 0.04481\right)} \cdot 0.70711\right) \]
      10. associate-*l/100.0%

        \[\leadsto \mathsf{fma}\left(x, -0.70711, \color{blue}{\frac{\left(2.30753 + x \cdot 0.27061\right) \cdot 0.70711}{1 + x \cdot \left(0.99229 + x \cdot 0.04481\right)}}\right) \]
    3. Simplified100.0%

      \[\leadsto \color{blue}{\mathsf{fma}\left(x, -0.70711, \frac{\mathsf{fma}\left(x, 0.1913510371, 1.6316775383\right)}{\mathsf{fma}\left(x, \mathsf{fma}\left(x, 0.04481, 0.99229\right), 1\right)}\right)} \]
    4. Taylor expanded in x around 0 98.4%

      \[\leadsto \color{blue}{-2.134856267379707 \cdot x + 1.6316775383} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification98.7%

    \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq -1.05 \lor \neg \left(x \leq 2.8\right):\\ \;\;\;\;\frac{4.2702753202410175}{x} + x \cdot -0.70711\\ \mathbf{else}:\\ \;\;\;\;x \cdot -2.134856267379707 + 1.6316775383\\ \end{array} \]

Alternative 7: 98.8% accurate, 2.1× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq -1.05:\\ \;\;\;\;x \cdot -0.70711\\ \mathbf{elif}\;x \leq 1.12:\\ \;\;\;\;x \cdot -2.134856267379707 + 1.6316775383\\ \mathbf{else}:\\ \;\;\;\;x \cdot -0.70711\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (if (<= x -1.05)
   (* x -0.70711)
   (if (<= x 1.12) (+ (* x -2.134856267379707) 1.6316775383) (* x -0.70711))))
double code(double x) {
	double tmp;
	if (x <= -1.05) {
		tmp = x * -0.70711;
	} else if (x <= 1.12) {
		tmp = (x * -2.134856267379707) + 1.6316775383;
	} else {
		tmp = x * -0.70711;
	}
	return tmp;
}
real(8) function code(x)
    real(8), intent (in) :: x
    real(8) :: tmp
    if (x <= (-1.05d0)) then
        tmp = x * (-0.70711d0)
    else if (x <= 1.12d0) then
        tmp = (x * (-2.134856267379707d0)) + 1.6316775383d0
    else
        tmp = x * (-0.70711d0)
    end if
    code = tmp
end function
public static double code(double x) {
	double tmp;
	if (x <= -1.05) {
		tmp = x * -0.70711;
	} else if (x <= 1.12) {
		tmp = (x * -2.134856267379707) + 1.6316775383;
	} else {
		tmp = x * -0.70711;
	}
	return tmp;
}
def code(x):
	tmp = 0
	if x <= -1.05:
		tmp = x * -0.70711
	elif x <= 1.12:
		tmp = (x * -2.134856267379707) + 1.6316775383
	else:
		tmp = x * -0.70711
	return tmp
function code(x)
	tmp = 0.0
	if (x <= -1.05)
		tmp = Float64(x * -0.70711);
	elseif (x <= 1.12)
		tmp = Float64(Float64(x * -2.134856267379707) + 1.6316775383);
	else
		tmp = Float64(x * -0.70711);
	end
	return tmp
end
function tmp_2 = code(x)
	tmp = 0.0;
	if (x <= -1.05)
		tmp = x * -0.70711;
	elseif (x <= 1.12)
		tmp = (x * -2.134856267379707) + 1.6316775383;
	else
		tmp = x * -0.70711;
	end
	tmp_2 = tmp;
end
code[x_] := If[LessEqual[x, -1.05], N[(x * -0.70711), $MachinePrecision], If[LessEqual[x, 1.12], N[(N[(x * -2.134856267379707), $MachinePrecision] + 1.6316775383), $MachinePrecision], N[(x * -0.70711), $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;x \leq -1.05:\\
\;\;\;\;x \cdot -0.70711\\

\mathbf{elif}\;x \leq 1.12:\\
\;\;\;\;x \cdot -2.134856267379707 + 1.6316775383\\

\mathbf{else}:\\
\;\;\;\;x \cdot -0.70711\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if x < -1.05000000000000004 or 1.1200000000000001 < x

    1. Initial program 99.8%

      \[0.70711 \cdot \left(\frac{2.30753 + x \cdot 0.27061}{1 + x \cdot \left(0.99229 + x \cdot 0.04481\right)} - x\right) \]
    2. Step-by-step derivation
      1. sub-neg99.8%

        \[\leadsto 0.70711 \cdot \color{blue}{\left(\frac{2.30753 + x \cdot 0.27061}{1 + x \cdot \left(0.99229 + x \cdot 0.04481\right)} + \left(-x\right)\right)} \]
      2. +-commutative99.8%

        \[\leadsto 0.70711 \cdot \color{blue}{\left(\left(-x\right) + \frac{2.30753 + x \cdot 0.27061}{1 + x \cdot \left(0.99229 + x \cdot 0.04481\right)}\right)} \]
      3. distribute-rgt-in99.8%

        \[\leadsto \color{blue}{\left(-x\right) \cdot 0.70711 + \frac{2.30753 + x \cdot 0.27061}{1 + x \cdot \left(0.99229 + x \cdot 0.04481\right)} \cdot 0.70711} \]
      4. distribute-lft-neg-out99.8%

        \[\leadsto \color{blue}{\left(-x \cdot 0.70711\right)} + \frac{2.30753 + x \cdot 0.27061}{1 + x \cdot \left(0.99229 + x \cdot 0.04481\right)} \cdot 0.70711 \]
      5. distribute-rgt-neg-in99.8%

        \[\leadsto \color{blue}{x \cdot \left(-0.70711\right)} + \frac{2.30753 + x \cdot 0.27061}{1 + x \cdot \left(0.99229 + x \cdot 0.04481\right)} \cdot 0.70711 \]
      6. metadata-eval99.8%

        \[\leadsto x \cdot \color{blue}{-0.70711} + \frac{2.30753 + x \cdot 0.27061}{1 + x \cdot \left(0.99229 + x \cdot 0.04481\right)} \cdot 0.70711 \]
      7. metadata-eval99.8%

        \[\leadsto x \cdot \color{blue}{\left(0.70711 \cdot -1\right)} + \frac{2.30753 + x \cdot 0.27061}{1 + x \cdot \left(0.99229 + x \cdot 0.04481\right)} \cdot 0.70711 \]
      8. fma-def99.8%

        \[\leadsto \color{blue}{\mathsf{fma}\left(x, 0.70711 \cdot -1, \frac{2.30753 + x \cdot 0.27061}{1 + x \cdot \left(0.99229 + x \cdot 0.04481\right)} \cdot 0.70711\right)} \]
      9. metadata-eval99.8%

        \[\leadsto \mathsf{fma}\left(x, \color{blue}{-0.70711}, \frac{2.30753 + x \cdot 0.27061}{1 + x \cdot \left(0.99229 + x \cdot 0.04481\right)} \cdot 0.70711\right) \]
      10. associate-*l/99.8%

        \[\leadsto \mathsf{fma}\left(x, -0.70711, \color{blue}{\frac{\left(2.30753 + x \cdot 0.27061\right) \cdot 0.70711}{1 + x \cdot \left(0.99229 + x \cdot 0.04481\right)}}\right) \]
    3. Simplified99.8%

      \[\leadsto \color{blue}{\mathsf{fma}\left(x, -0.70711, \frac{\mathsf{fma}\left(x, 0.1913510371, 1.6316775383\right)}{\mathsf{fma}\left(x, \mathsf{fma}\left(x, 0.04481, 0.99229\right), 1\right)}\right)} \]
    4. Taylor expanded in x around inf 98.1%

      \[\leadsto \color{blue}{-0.70711 \cdot x} \]
    5. Step-by-step derivation
      1. *-commutative98.1%

        \[\leadsto \color{blue}{x \cdot -0.70711} \]
    6. Simplified98.1%

      \[\leadsto \color{blue}{x \cdot -0.70711} \]

    if -1.05000000000000004 < x < 1.1200000000000001

    1. Initial program 100.0%

      \[0.70711 \cdot \left(\frac{2.30753 + x \cdot 0.27061}{1 + x \cdot \left(0.99229 + x \cdot 0.04481\right)} - x\right) \]
    2. Step-by-step derivation
      1. sub-neg100.0%

        \[\leadsto 0.70711 \cdot \color{blue}{\left(\frac{2.30753 + x \cdot 0.27061}{1 + x \cdot \left(0.99229 + x \cdot 0.04481\right)} + \left(-x\right)\right)} \]
      2. +-commutative100.0%

        \[\leadsto 0.70711 \cdot \color{blue}{\left(\left(-x\right) + \frac{2.30753 + x \cdot 0.27061}{1 + x \cdot \left(0.99229 + x \cdot 0.04481\right)}\right)} \]
      3. distribute-rgt-in99.9%

        \[\leadsto \color{blue}{\left(-x\right) \cdot 0.70711 + \frac{2.30753 + x \cdot 0.27061}{1 + x \cdot \left(0.99229 + x \cdot 0.04481\right)} \cdot 0.70711} \]
      4. distribute-lft-neg-out99.9%

        \[\leadsto \color{blue}{\left(-x \cdot 0.70711\right)} + \frac{2.30753 + x \cdot 0.27061}{1 + x \cdot \left(0.99229 + x \cdot 0.04481\right)} \cdot 0.70711 \]
      5. distribute-rgt-neg-in99.9%

        \[\leadsto \color{blue}{x \cdot \left(-0.70711\right)} + \frac{2.30753 + x \cdot 0.27061}{1 + x \cdot \left(0.99229 + x \cdot 0.04481\right)} \cdot 0.70711 \]
      6. metadata-eval99.9%

        \[\leadsto x \cdot \color{blue}{-0.70711} + \frac{2.30753 + x \cdot 0.27061}{1 + x \cdot \left(0.99229 + x \cdot 0.04481\right)} \cdot 0.70711 \]
      7. metadata-eval99.9%

        \[\leadsto x \cdot \color{blue}{\left(0.70711 \cdot -1\right)} + \frac{2.30753 + x \cdot 0.27061}{1 + x \cdot \left(0.99229 + x \cdot 0.04481\right)} \cdot 0.70711 \]
      8. fma-def99.9%

        \[\leadsto \color{blue}{\mathsf{fma}\left(x, 0.70711 \cdot -1, \frac{2.30753 + x \cdot 0.27061}{1 + x \cdot \left(0.99229 + x \cdot 0.04481\right)} \cdot 0.70711\right)} \]
      9. metadata-eval99.9%

        \[\leadsto \mathsf{fma}\left(x, \color{blue}{-0.70711}, \frac{2.30753 + x \cdot 0.27061}{1 + x \cdot \left(0.99229 + x \cdot 0.04481\right)} \cdot 0.70711\right) \]
      10. associate-*l/100.0%

        \[\leadsto \mathsf{fma}\left(x, -0.70711, \color{blue}{\frac{\left(2.30753 + x \cdot 0.27061\right) \cdot 0.70711}{1 + x \cdot \left(0.99229 + x \cdot 0.04481\right)}}\right) \]
    3. Simplified100.0%

      \[\leadsto \color{blue}{\mathsf{fma}\left(x, -0.70711, \frac{\mathsf{fma}\left(x, 0.1913510371, 1.6316775383\right)}{\mathsf{fma}\left(x, \mathsf{fma}\left(x, 0.04481, 0.99229\right), 1\right)}\right)} \]
    4. Taylor expanded in x around 0 99.1%

      \[\leadsto \color{blue}{-2.134856267379707 \cdot x + 1.6316775383} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification98.6%

    \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq -1.05:\\ \;\;\;\;x \cdot -0.70711\\ \mathbf{elif}\;x \leq 1.12:\\ \;\;\;\;x \cdot -2.134856267379707 + 1.6316775383\\ \mathbf{else}:\\ \;\;\;\;x \cdot -0.70711\\ \end{array} \]

Alternative 8: 98.1% accurate, 2.7× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq -1.05:\\ \;\;\;\;x \cdot -0.70711\\ \mathbf{elif}\;x \leq 1.15:\\ \;\;\;\;1.6316775383\\ \mathbf{else}:\\ \;\;\;\;x \cdot -0.70711\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (if (<= x -1.05) (* x -0.70711) (if (<= x 1.15) 1.6316775383 (* x -0.70711))))
double code(double x) {
	double tmp;
	if (x <= -1.05) {
		tmp = x * -0.70711;
	} else if (x <= 1.15) {
		tmp = 1.6316775383;
	} else {
		tmp = x * -0.70711;
	}
	return tmp;
}
real(8) function code(x)
    real(8), intent (in) :: x
    real(8) :: tmp
    if (x <= (-1.05d0)) then
        tmp = x * (-0.70711d0)
    else if (x <= 1.15d0) then
        tmp = 1.6316775383d0
    else
        tmp = x * (-0.70711d0)
    end if
    code = tmp
end function
public static double code(double x) {
	double tmp;
	if (x <= -1.05) {
		tmp = x * -0.70711;
	} else if (x <= 1.15) {
		tmp = 1.6316775383;
	} else {
		tmp = x * -0.70711;
	}
	return tmp;
}
def code(x):
	tmp = 0
	if x <= -1.05:
		tmp = x * -0.70711
	elif x <= 1.15:
		tmp = 1.6316775383
	else:
		tmp = x * -0.70711
	return tmp
function code(x)
	tmp = 0.0
	if (x <= -1.05)
		tmp = Float64(x * -0.70711);
	elseif (x <= 1.15)
		tmp = 1.6316775383;
	else
		tmp = Float64(x * -0.70711);
	end
	return tmp
end
function tmp_2 = code(x)
	tmp = 0.0;
	if (x <= -1.05)
		tmp = x * -0.70711;
	elseif (x <= 1.15)
		tmp = 1.6316775383;
	else
		tmp = x * -0.70711;
	end
	tmp_2 = tmp;
end
code[x_] := If[LessEqual[x, -1.05], N[(x * -0.70711), $MachinePrecision], If[LessEqual[x, 1.15], 1.6316775383, N[(x * -0.70711), $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;x \leq -1.05:\\
\;\;\;\;x \cdot -0.70711\\

\mathbf{elif}\;x \leq 1.15:\\
\;\;\;\;1.6316775383\\

\mathbf{else}:\\
\;\;\;\;x \cdot -0.70711\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if x < -1.05000000000000004 or 1.1499999999999999 < x

    1. Initial program 99.8%

      \[0.70711 \cdot \left(\frac{2.30753 + x \cdot 0.27061}{1 + x \cdot \left(0.99229 + x \cdot 0.04481\right)} - x\right) \]
    2. Step-by-step derivation
      1. sub-neg99.8%

        \[\leadsto 0.70711 \cdot \color{blue}{\left(\frac{2.30753 + x \cdot 0.27061}{1 + x \cdot \left(0.99229 + x \cdot 0.04481\right)} + \left(-x\right)\right)} \]
      2. +-commutative99.8%

        \[\leadsto 0.70711 \cdot \color{blue}{\left(\left(-x\right) + \frac{2.30753 + x \cdot 0.27061}{1 + x \cdot \left(0.99229 + x \cdot 0.04481\right)}\right)} \]
      3. distribute-rgt-in99.8%

        \[\leadsto \color{blue}{\left(-x\right) \cdot 0.70711 + \frac{2.30753 + x \cdot 0.27061}{1 + x \cdot \left(0.99229 + x \cdot 0.04481\right)} \cdot 0.70711} \]
      4. distribute-lft-neg-out99.8%

        \[\leadsto \color{blue}{\left(-x \cdot 0.70711\right)} + \frac{2.30753 + x \cdot 0.27061}{1 + x \cdot \left(0.99229 + x \cdot 0.04481\right)} \cdot 0.70711 \]
      5. distribute-rgt-neg-in99.8%

        \[\leadsto \color{blue}{x \cdot \left(-0.70711\right)} + \frac{2.30753 + x \cdot 0.27061}{1 + x \cdot \left(0.99229 + x \cdot 0.04481\right)} \cdot 0.70711 \]
      6. metadata-eval99.8%

        \[\leadsto x \cdot \color{blue}{-0.70711} + \frac{2.30753 + x \cdot 0.27061}{1 + x \cdot \left(0.99229 + x \cdot 0.04481\right)} \cdot 0.70711 \]
      7. metadata-eval99.8%

        \[\leadsto x \cdot \color{blue}{\left(0.70711 \cdot -1\right)} + \frac{2.30753 + x \cdot 0.27061}{1 + x \cdot \left(0.99229 + x \cdot 0.04481\right)} \cdot 0.70711 \]
      8. fma-def99.8%

        \[\leadsto \color{blue}{\mathsf{fma}\left(x, 0.70711 \cdot -1, \frac{2.30753 + x \cdot 0.27061}{1 + x \cdot \left(0.99229 + x \cdot 0.04481\right)} \cdot 0.70711\right)} \]
      9. metadata-eval99.8%

        \[\leadsto \mathsf{fma}\left(x, \color{blue}{-0.70711}, \frac{2.30753 + x \cdot 0.27061}{1 + x \cdot \left(0.99229 + x \cdot 0.04481\right)} \cdot 0.70711\right) \]
      10. associate-*l/99.8%

        \[\leadsto \mathsf{fma}\left(x, -0.70711, \color{blue}{\frac{\left(2.30753 + x \cdot 0.27061\right) \cdot 0.70711}{1 + x \cdot \left(0.99229 + x \cdot 0.04481\right)}}\right) \]
    3. Simplified99.8%

      \[\leadsto \color{blue}{\mathsf{fma}\left(x, -0.70711, \frac{\mathsf{fma}\left(x, 0.1913510371, 1.6316775383\right)}{\mathsf{fma}\left(x, \mathsf{fma}\left(x, 0.04481, 0.99229\right), 1\right)}\right)} \]
    4. Taylor expanded in x around inf 98.1%

      \[\leadsto \color{blue}{-0.70711 \cdot x} \]
    5. Step-by-step derivation
      1. *-commutative98.1%

        \[\leadsto \color{blue}{x \cdot -0.70711} \]
    6. Simplified98.1%

      \[\leadsto \color{blue}{x \cdot -0.70711} \]

    if -1.05000000000000004 < x < 1.1499999999999999

    1. Initial program 100.0%

      \[0.70711 \cdot \left(\frac{2.30753 + x \cdot 0.27061}{1 + x \cdot \left(0.99229 + x \cdot 0.04481\right)} - x\right) \]
    2. Taylor expanded in x around 0 99.2%

      \[\leadsto 0.70711 \cdot \left(\frac{2.30753 + x \cdot 0.27061}{1 + \color{blue}{0.99229 \cdot x}} - x\right) \]
    3. Step-by-step derivation
      1. *-commutative99.2%

        \[\leadsto 0.70711 \cdot \left(\frac{2.30753 + x \cdot 0.27061}{1 + \color{blue}{x \cdot 0.99229}} - x\right) \]
    4. Simplified99.2%

      \[\leadsto 0.70711 \cdot \left(\frac{2.30753 + x \cdot 0.27061}{1 + \color{blue}{x \cdot 0.99229}} - x\right) \]
    5. Taylor expanded in x around 0 98.1%

      \[\leadsto \color{blue}{1.6316775383} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification98.1%

    \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq -1.05:\\ \;\;\;\;x \cdot -0.70711\\ \mathbf{elif}\;x \leq 1.15:\\ \;\;\;\;1.6316775383\\ \mathbf{else}:\\ \;\;\;\;x \cdot -0.70711\\ \end{array} \]

Alternative 9: 9.8% accurate, 19.0× speedup?

\[\begin{array}{l} \\ 0.1928378166664987 \end{array} \]
(FPCore (x) :precision binary64 0.1928378166664987)
double code(double x) {
	return 0.1928378166664987;
}
real(8) function code(x)
    real(8), intent (in) :: x
    code = 0.1928378166664987d0
end function
public static double code(double x) {
	return 0.1928378166664987;
}
def code(x):
	return 0.1928378166664987
function code(x)
	return 0.1928378166664987
end
function tmp = code(x)
	tmp = 0.1928378166664987;
end
code[x_] := 0.1928378166664987
\begin{array}{l}

\\
0.1928378166664987
\end{array}
Derivation
  1. Initial program 99.9%

    \[0.70711 \cdot \left(\frac{2.30753 + x \cdot 0.27061}{1 + x \cdot \left(0.99229 + x \cdot 0.04481\right)} - x\right) \]
  2. Taylor expanded in x around 0 98.2%

    \[\leadsto 0.70711 \cdot \left(\frac{2.30753 + x \cdot 0.27061}{1 + \color{blue}{0.99229 \cdot x}} - x\right) \]
  3. Step-by-step derivation
    1. *-commutative98.2%

      \[\leadsto 0.70711 \cdot \left(\frac{2.30753 + x \cdot 0.27061}{1 + \color{blue}{x \cdot 0.99229}} - x\right) \]
  4. Simplified98.2%

    \[\leadsto 0.70711 \cdot \left(\frac{2.30753 + x \cdot 0.27061}{1 + \color{blue}{x \cdot 0.99229}} - x\right) \]
  5. Taylor expanded in x around inf 57.0%

    \[\leadsto \color{blue}{0.1928378166664987 + -0.70711 \cdot x} \]
  6. Step-by-step derivation
    1. *-commutative57.0%

      \[\leadsto 0.1928378166664987 + \color{blue}{x \cdot -0.70711} \]
  7. Simplified57.0%

    \[\leadsto \color{blue}{0.1928378166664987 + x \cdot -0.70711} \]
  8. Taylor expanded in x around 0 9.6%

    \[\leadsto \color{blue}{0.1928378166664987} \]
  9. Final simplification9.6%

    \[\leadsto 0.1928378166664987 \]

Alternative 10: 51.1% accurate, 19.0× speedup?

\[\begin{array}{l} \\ 1.6316775383 \end{array} \]
(FPCore (x) :precision binary64 1.6316775383)
double code(double x) {
	return 1.6316775383;
}
real(8) function code(x)
    real(8), intent (in) :: x
    code = 1.6316775383d0
end function
public static double code(double x) {
	return 1.6316775383;
}
def code(x):
	return 1.6316775383
function code(x)
	return 1.6316775383
end
function tmp = code(x)
	tmp = 1.6316775383;
end
code[x_] := 1.6316775383
\begin{array}{l}

\\
1.6316775383
\end{array}
Derivation
  1. Initial program 99.9%

    \[0.70711 \cdot \left(\frac{2.30753 + x \cdot 0.27061}{1 + x \cdot \left(0.99229 + x \cdot 0.04481\right)} - x\right) \]
  2. Taylor expanded in x around 0 98.2%

    \[\leadsto 0.70711 \cdot \left(\frac{2.30753 + x \cdot 0.27061}{1 + \color{blue}{0.99229 \cdot x}} - x\right) \]
  3. Step-by-step derivation
    1. *-commutative98.2%

      \[\leadsto 0.70711 \cdot \left(\frac{2.30753 + x \cdot 0.27061}{1 + \color{blue}{x \cdot 0.99229}} - x\right) \]
  4. Simplified98.2%

    \[\leadsto 0.70711 \cdot \left(\frac{2.30753 + x \cdot 0.27061}{1 + \color{blue}{x \cdot 0.99229}} - x\right) \]
  5. Taylor expanded in x around 0 50.3%

    \[\leadsto \color{blue}{1.6316775383} \]
  6. Final simplification50.3%

    \[\leadsto 1.6316775383 \]

Reproduce

?
herbie shell --seed 2023229 
(FPCore (x)
  :name "Numeric.SpecFunctions:invErfc from math-functions-0.1.5.2, B"
  :precision binary64
  (* 0.70711 (- (/ (+ 2.30753 (* x 0.27061)) (+ 1.0 (* x (+ 0.99229 (* x 0.04481))))) x)))