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

Percentage Accurate: 99.8% → 99.9%
Time: 10.3s
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: 99.8% 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?

\[\begin{array}{l} \\ x \cdot -0.70711 + \frac{1.6316775383 + x \cdot 0.1913510371}{1 - x \cdot \left(-0.99229 + x \cdot -0.04481\right)} \end{array} \]
(FPCore (x)
 :precision binary64
 (+
  (* x -0.70711)
  (/
   (+ 1.6316775383 (* x 0.1913510371))
   (- 1.0 (* x (+ -0.99229 (* x -0.04481)))))))
double code(double x) {
	return (x * -0.70711) + ((1.6316775383 + (x * 0.1913510371)) / (1.0 - (x * (-0.99229 + (x * -0.04481)))));
}
real(8) function code(x)
    real(8), intent (in) :: x
    code = (x * (-0.70711d0)) + ((1.6316775383d0 + (x * 0.1913510371d0)) / (1.0d0 - (x * ((-0.99229d0) + (x * (-0.04481d0))))))
end function
public static double code(double x) {
	return (x * -0.70711) + ((1.6316775383 + (x * 0.1913510371)) / (1.0 - (x * (-0.99229 + (x * -0.04481)))));
}
def code(x):
	return (x * -0.70711) + ((1.6316775383 + (x * 0.1913510371)) / (1.0 - (x * (-0.99229 + (x * -0.04481)))))
function code(x)
	return Float64(Float64(x * -0.70711) + Float64(Float64(1.6316775383 + Float64(x * 0.1913510371)) / Float64(1.0 - Float64(x * Float64(-0.99229 + Float64(x * -0.04481))))))
end
function tmp = code(x)
	tmp = (x * -0.70711) + ((1.6316775383 + (x * 0.1913510371)) / (1.0 - (x * (-0.99229 + (x * -0.04481)))));
end
code[x_] := N[(N[(x * -0.70711), $MachinePrecision] + N[(N[(1.6316775383 + N[(x * 0.1913510371), $MachinePrecision]), $MachinePrecision] / N[(1.0 - N[(x * N[(-0.99229 + N[(x * -0.04481), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
x \cdot -0.70711 + \frac{1.6316775383 + x \cdot 0.1913510371}{1 - x \cdot \left(-0.99229 + x \cdot -0.04481\right)}
\end{array}
Derivation
  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-negN/A

      \[\leadsto \frac{70711}{100000} \cdot \left(\frac{\frac{230753}{100000} + x \cdot \frac{27061}{100000}}{1 + x \cdot \left(\frac{99229}{100000} + x \cdot \frac{4481}{100000}\right)} + \color{blue}{\left(\mathsf{neg}\left(x\right)\right)}\right) \]
    2. +-commutativeN/A

      \[\leadsto \frac{70711}{100000} \cdot \left(\left(\mathsf{neg}\left(x\right)\right) + \color{blue}{\frac{\frac{230753}{100000} + x \cdot \frac{27061}{100000}}{1 + x \cdot \left(\frac{99229}{100000} + x \cdot \frac{4481}{100000}\right)}}\right) \]
    3. distribute-lft-inN/A

      \[\leadsto \frac{70711}{100000} \cdot \left(\mathsf{neg}\left(x\right)\right) + \color{blue}{\frac{70711}{100000} \cdot \frac{\frac{230753}{100000} + x \cdot \frac{27061}{100000}}{1 + x \cdot \left(\frac{99229}{100000} + x \cdot \frac{4481}{100000}\right)}} \]
    4. *-commutativeN/A

      \[\leadsto \frac{70711}{100000} \cdot \left(\mathsf{neg}\left(x\right)\right) + \frac{\frac{230753}{100000} + x \cdot \frac{27061}{100000}}{1 + x \cdot \left(\frac{99229}{100000} + x \cdot \frac{4481}{100000}\right)} \cdot \color{blue}{\frac{70711}{100000}} \]
    5. +-lowering-+.f64N/A

      \[\leadsto \mathsf{+.f64}\left(\left(\frac{70711}{100000} \cdot \left(\mathsf{neg}\left(x\right)\right)\right), \color{blue}{\left(\frac{\frac{230753}{100000} + x \cdot \frac{27061}{100000}}{1 + x \cdot \left(\frac{99229}{100000} + x \cdot \frac{4481}{100000}\right)} \cdot \frac{70711}{100000}\right)}\right) \]
    6. neg-mul-1N/A

      \[\leadsto \mathsf{+.f64}\left(\left(\frac{70711}{100000} \cdot \left(-1 \cdot x\right)\right), \left(\frac{\frac{230753}{100000} + x \cdot \frac{27061}{100000}}{\color{blue}{1 + x \cdot \left(\frac{99229}{100000} + x \cdot \frac{4481}{100000}\right)}} \cdot \frac{70711}{100000}\right)\right) \]
    7. associate-*r*N/A

      \[\leadsto \mathsf{+.f64}\left(\left(\left(\frac{70711}{100000} \cdot -1\right) \cdot x\right), \left(\color{blue}{\frac{\frac{230753}{100000} + x \cdot \frac{27061}{100000}}{1 + x \cdot \left(\frac{99229}{100000} + x \cdot \frac{4481}{100000}\right)}} \cdot \frac{70711}{100000}\right)\right) \]
    8. *-commutativeN/A

      \[\leadsto \mathsf{+.f64}\left(\left(x \cdot \left(\frac{70711}{100000} \cdot -1\right)\right), \left(\color{blue}{\frac{\frac{230753}{100000} + x \cdot \frac{27061}{100000}}{1 + x \cdot \left(\frac{99229}{100000} + x \cdot \frac{4481}{100000}\right)}} \cdot \frac{70711}{100000}\right)\right) \]
    9. *-lowering-*.f64N/A

      \[\leadsto \mathsf{+.f64}\left(\mathsf{*.f64}\left(x, \left(\frac{70711}{100000} \cdot -1\right)\right), \left(\color{blue}{\frac{\frac{230753}{100000} + x \cdot \frac{27061}{100000}}{1 + x \cdot \left(\frac{99229}{100000} + x \cdot \frac{4481}{100000}\right)}} \cdot \frac{70711}{100000}\right)\right) \]
    10. metadata-evalN/A

      \[\leadsto \mathsf{+.f64}\left(\mathsf{*.f64}\left(x, \frac{-70711}{100000}\right), \left(\frac{\frac{230753}{100000} + x \cdot \frac{27061}{100000}}{\color{blue}{1 + x \cdot \left(\frac{99229}{100000} + x \cdot \frac{4481}{100000}\right)}} \cdot \frac{70711}{100000}\right)\right) \]
    11. *-commutativeN/A

      \[\leadsto \mathsf{+.f64}\left(\mathsf{*.f64}\left(x, \frac{-70711}{100000}\right), \left(\frac{70711}{100000} \cdot \color{blue}{\frac{\frac{230753}{100000} + x \cdot \frac{27061}{100000}}{1 + x \cdot \left(\frac{99229}{100000} + x \cdot \frac{4481}{100000}\right)}}\right)\right) \]
    12. associate-*r/N/A

      \[\leadsto \mathsf{+.f64}\left(\mathsf{*.f64}\left(x, \frac{-70711}{100000}\right), \left(\frac{\frac{70711}{100000} \cdot \left(\frac{230753}{100000} + x \cdot \frac{27061}{100000}\right)}{\color{blue}{1 + x \cdot \left(\frac{99229}{100000} + x \cdot \frac{4481}{100000}\right)}}\right)\right) \]
    13. /-lowering-/.f64N/A

      \[\leadsto \mathsf{+.f64}\left(\mathsf{*.f64}\left(x, \frac{-70711}{100000}\right), \mathsf{/.f64}\left(\left(\frac{70711}{100000} \cdot \left(\frac{230753}{100000} + x \cdot \frac{27061}{100000}\right)\right), \color{blue}{\left(1 + x \cdot \left(\frac{99229}{100000} + x \cdot \frac{4481}{100000}\right)\right)}\right)\right) \]
  3. Simplified99.8%

    \[\leadsto \color{blue}{x \cdot -0.70711 + \frac{1.6316775383 + x \cdot 0.1913510371}{1 - x \cdot \left(-0.99229 + x \cdot -0.04481\right)}} \]
  4. Add Preprocessing
  5. Add Preprocessing

Alternative 2: 99.3% accurate, 0.8× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq -1.05:\\ \;\;\;\;0.70711 \cdot \left(\frac{6.039053782637804}{x} - x\right)\\ \mathbf{elif}\;x \leq 6.2:\\ \;\;\;\;1.6316775383 + x \cdot \left(-2.134856267379707 + x \cdot \left(1.3436228731669864 + x \cdot -1.2692862305735844\right)\right)\\ \mathbf{else}:\\ \;\;\;\;x \cdot -0.70711 + \frac{4.2702753202410175 + \frac{\frac{1192.3851440772235}{x} + -58.14938538768042}{x}}{x}\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (if (<= x -1.05)
   (* 0.70711 (- (/ 6.039053782637804 x) x))
   (if (<= x 6.2)
     (+
      1.6316775383
      (*
       x
       (+
        -2.134856267379707
        (* x (+ 1.3436228731669864 (* x -1.2692862305735844))))))
     (+
      (* x -0.70711)
      (/
       (+
        4.2702753202410175
        (/ (+ (/ 1192.3851440772235 x) -58.14938538768042) x))
       x)))))
double code(double x) {
	double tmp;
	if (x <= -1.05) {
		tmp = 0.70711 * ((6.039053782637804 / x) - x);
	} else if (x <= 6.2) {
		tmp = 1.6316775383 + (x * (-2.134856267379707 + (x * (1.3436228731669864 + (x * -1.2692862305735844)))));
	} else {
		tmp = (x * -0.70711) + ((4.2702753202410175 + (((1192.3851440772235 / x) + -58.14938538768042) / x)) / x);
	}
	return tmp;
}
real(8) function code(x)
    real(8), intent (in) :: x
    real(8) :: tmp
    if (x <= (-1.05d0)) then
        tmp = 0.70711d0 * ((6.039053782637804d0 / x) - x)
    else if (x <= 6.2d0) then
        tmp = 1.6316775383d0 + (x * ((-2.134856267379707d0) + (x * (1.3436228731669864d0 + (x * (-1.2692862305735844d0))))))
    else
        tmp = (x * (-0.70711d0)) + ((4.2702753202410175d0 + (((1192.3851440772235d0 / x) + (-58.14938538768042d0)) / x)) / x)
    end if
    code = tmp
end function
public static double code(double x) {
	double tmp;
	if (x <= -1.05) {
		tmp = 0.70711 * ((6.039053782637804 / x) - x);
	} else if (x <= 6.2) {
		tmp = 1.6316775383 + (x * (-2.134856267379707 + (x * (1.3436228731669864 + (x * -1.2692862305735844)))));
	} else {
		tmp = (x * -0.70711) + ((4.2702753202410175 + (((1192.3851440772235 / x) + -58.14938538768042) / x)) / x);
	}
	return tmp;
}
def code(x):
	tmp = 0
	if x <= -1.05:
		tmp = 0.70711 * ((6.039053782637804 / x) - x)
	elif x <= 6.2:
		tmp = 1.6316775383 + (x * (-2.134856267379707 + (x * (1.3436228731669864 + (x * -1.2692862305735844)))))
	else:
		tmp = (x * -0.70711) + ((4.2702753202410175 + (((1192.3851440772235 / x) + -58.14938538768042) / x)) / x)
	return tmp
function code(x)
	tmp = 0.0
	if (x <= -1.05)
		tmp = Float64(0.70711 * Float64(Float64(6.039053782637804 / x) - x));
	elseif (x <= 6.2)
		tmp = Float64(1.6316775383 + Float64(x * Float64(-2.134856267379707 + Float64(x * Float64(1.3436228731669864 + Float64(x * -1.2692862305735844))))));
	else
		tmp = Float64(Float64(x * -0.70711) + Float64(Float64(4.2702753202410175 + Float64(Float64(Float64(1192.3851440772235 / x) + -58.14938538768042) / x)) / x));
	end
	return tmp
end
function tmp_2 = code(x)
	tmp = 0.0;
	if (x <= -1.05)
		tmp = 0.70711 * ((6.039053782637804 / x) - x);
	elseif (x <= 6.2)
		tmp = 1.6316775383 + (x * (-2.134856267379707 + (x * (1.3436228731669864 + (x * -1.2692862305735844)))));
	else
		tmp = (x * -0.70711) + ((4.2702753202410175 + (((1192.3851440772235 / x) + -58.14938538768042) / x)) / x);
	end
	tmp_2 = tmp;
end
code[x_] := If[LessEqual[x, -1.05], N[(0.70711 * N[(N[(6.039053782637804 / x), $MachinePrecision] - x), $MachinePrecision]), $MachinePrecision], If[LessEqual[x, 6.2], N[(1.6316775383 + N[(x * N[(-2.134856267379707 + N[(x * N[(1.3436228731669864 + N[(x * -1.2692862305735844), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(N[(x * -0.70711), $MachinePrecision] + N[(N[(4.2702753202410175 + N[(N[(N[(1192.3851440772235 / x), $MachinePrecision] + -58.14938538768042), $MachinePrecision] / x), $MachinePrecision]), $MachinePrecision] / x), $MachinePrecision]), $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;x \leq -1.05:\\
\;\;\;\;0.70711 \cdot \left(\frac{6.039053782637804}{x} - x\right)\\

\mathbf{elif}\;x \leq 6.2:\\
\;\;\;\;1.6316775383 + x \cdot \left(-2.134856267379707 + x \cdot \left(1.3436228731669864 + x \cdot -1.2692862305735844\right)\right)\\

\mathbf{else}:\\
\;\;\;\;x \cdot -0.70711 + \frac{4.2702753202410175 + \frac{\frac{1192.3851440772235}{x} + -58.14938538768042}{x}}{x}\\


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

    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. Add Preprocessing
    3. Taylor expanded in x around inf

      \[\leadsto \mathsf{*.f64}\left(\frac{70711}{100000}, \mathsf{\_.f64}\left(\color{blue}{\left(\frac{\frac{27061}{4481}}{x}\right)}, x\right)\right) \]
    4. Step-by-step derivation
      1. /-lowering-/.f6499.8%

        \[\leadsto \mathsf{*.f64}\left(\frac{70711}{100000}, \mathsf{\_.f64}\left(\mathsf{/.f64}\left(\frac{27061}{4481}, x\right), x\right)\right) \]
    5. Simplified99.8%

      \[\leadsto 0.70711 \cdot \left(\color{blue}{\frac{6.039053782637804}{x}} - x\right) \]

    if -1.05000000000000004 < x < 6.20000000000000018

    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. Add Preprocessing
    3. Taylor expanded in x around 0

      \[\leadsto \color{blue}{\frac{16316775383}{10000000000} + x \cdot \left(x \cdot \left(\frac{134362287316698645903}{100000000000000000000} + \frac{-12692862305735843227608787}{10000000000000000000000000} \cdot x\right) - \frac{2134856267379707}{1000000000000000}\right)} \]
    4. Step-by-step derivation
      1. +-lowering-+.f64N/A

        \[\leadsto \mathsf{+.f64}\left(\frac{16316775383}{10000000000}, \color{blue}{\left(x \cdot \left(x \cdot \left(\frac{134362287316698645903}{100000000000000000000} + \frac{-12692862305735843227608787}{10000000000000000000000000} \cdot x\right) - \frac{2134856267379707}{1000000000000000}\right)\right)}\right) \]
      2. *-lowering-*.f64N/A

        \[\leadsto \mathsf{+.f64}\left(\frac{16316775383}{10000000000}, \mathsf{*.f64}\left(x, \color{blue}{\left(x \cdot \left(\frac{134362287316698645903}{100000000000000000000} + \frac{-12692862305735843227608787}{10000000000000000000000000} \cdot x\right) - \frac{2134856267379707}{1000000000000000}\right)}\right)\right) \]
      3. sub-negN/A

        \[\leadsto \mathsf{+.f64}\left(\frac{16316775383}{10000000000}, \mathsf{*.f64}\left(x, \left(x \cdot \left(\frac{134362287316698645903}{100000000000000000000} + \frac{-12692862305735843227608787}{10000000000000000000000000} \cdot x\right) + \color{blue}{\left(\mathsf{neg}\left(\frac{2134856267379707}{1000000000000000}\right)\right)}\right)\right)\right) \]
      4. metadata-evalN/A

        \[\leadsto \mathsf{+.f64}\left(\frac{16316775383}{10000000000}, \mathsf{*.f64}\left(x, \left(x \cdot \left(\frac{134362287316698645903}{100000000000000000000} + \frac{-12692862305735843227608787}{10000000000000000000000000} \cdot x\right) + \frac{-2134856267379707}{1000000000000000}\right)\right)\right) \]
      5. +-commutativeN/A

        \[\leadsto \mathsf{+.f64}\left(\frac{16316775383}{10000000000}, \mathsf{*.f64}\left(x, \left(\frac{-2134856267379707}{1000000000000000} + \color{blue}{x \cdot \left(\frac{134362287316698645903}{100000000000000000000} + \frac{-12692862305735843227608787}{10000000000000000000000000} \cdot x\right)}\right)\right)\right) \]
      6. +-lowering-+.f64N/A

        \[\leadsto \mathsf{+.f64}\left(\frac{16316775383}{10000000000}, \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(\frac{-2134856267379707}{1000000000000000}, \color{blue}{\left(x \cdot \left(\frac{134362287316698645903}{100000000000000000000} + \frac{-12692862305735843227608787}{10000000000000000000000000} \cdot x\right)\right)}\right)\right)\right) \]
      7. *-lowering-*.f64N/A

        \[\leadsto \mathsf{+.f64}\left(\frac{16316775383}{10000000000}, \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(\frac{-2134856267379707}{1000000000000000}, \mathsf{*.f64}\left(x, \color{blue}{\left(\frac{134362287316698645903}{100000000000000000000} + \frac{-12692862305735843227608787}{10000000000000000000000000} \cdot x\right)}\right)\right)\right)\right) \]
      8. +-lowering-+.f64N/A

        \[\leadsto \mathsf{+.f64}\left(\frac{16316775383}{10000000000}, \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(\frac{-2134856267379707}{1000000000000000}, \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(\frac{134362287316698645903}{100000000000000000000}, \color{blue}{\left(\frac{-12692862305735843227608787}{10000000000000000000000000} \cdot x\right)}\right)\right)\right)\right)\right) \]
      9. *-commutativeN/A

        \[\leadsto \mathsf{+.f64}\left(\frac{16316775383}{10000000000}, \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(\frac{-2134856267379707}{1000000000000000}, \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(\frac{134362287316698645903}{100000000000000000000}, \left(x \cdot \color{blue}{\frac{-12692862305735843227608787}{10000000000000000000000000}}\right)\right)\right)\right)\right)\right) \]
      10. *-lowering-*.f6499.5%

        \[\leadsto \mathsf{+.f64}\left(\frac{16316775383}{10000000000}, \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(\frac{-2134856267379707}{1000000000000000}, \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(\frac{134362287316698645903}{100000000000000000000}, \mathsf{*.f64}\left(x, \color{blue}{\frac{-12692862305735843227608787}{10000000000000000000000000}}\right)\right)\right)\right)\right)\right) \]
    5. Simplified99.5%

      \[\leadsto \color{blue}{1.6316775383 + x \cdot \left(-2.134856267379707 + x \cdot \left(1.3436228731669864 + x \cdot -1.2692862305735844\right)\right)} \]

    if 6.20000000000000018 < 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-negN/A

        \[\leadsto \frac{70711}{100000} \cdot \left(\frac{\frac{230753}{100000} + x \cdot \frac{27061}{100000}}{1 + x \cdot \left(\frac{99229}{100000} + x \cdot \frac{4481}{100000}\right)} + \color{blue}{\left(\mathsf{neg}\left(x\right)\right)}\right) \]
      2. +-commutativeN/A

        \[\leadsto \frac{70711}{100000} \cdot \left(\left(\mathsf{neg}\left(x\right)\right) + \color{blue}{\frac{\frac{230753}{100000} + x \cdot \frac{27061}{100000}}{1 + x \cdot \left(\frac{99229}{100000} + x \cdot \frac{4481}{100000}\right)}}\right) \]
      3. distribute-lft-inN/A

        \[\leadsto \frac{70711}{100000} \cdot \left(\mathsf{neg}\left(x\right)\right) + \color{blue}{\frac{70711}{100000} \cdot \frac{\frac{230753}{100000} + x \cdot \frac{27061}{100000}}{1 + x \cdot \left(\frac{99229}{100000} + x \cdot \frac{4481}{100000}\right)}} \]
      4. *-commutativeN/A

        \[\leadsto \frac{70711}{100000} \cdot \left(\mathsf{neg}\left(x\right)\right) + \frac{\frac{230753}{100000} + x \cdot \frac{27061}{100000}}{1 + x \cdot \left(\frac{99229}{100000} + x \cdot \frac{4481}{100000}\right)} \cdot \color{blue}{\frac{70711}{100000}} \]
      5. +-lowering-+.f64N/A

        \[\leadsto \mathsf{+.f64}\left(\left(\frac{70711}{100000} \cdot \left(\mathsf{neg}\left(x\right)\right)\right), \color{blue}{\left(\frac{\frac{230753}{100000} + x \cdot \frac{27061}{100000}}{1 + x \cdot \left(\frac{99229}{100000} + x \cdot \frac{4481}{100000}\right)} \cdot \frac{70711}{100000}\right)}\right) \]
      6. neg-mul-1N/A

        \[\leadsto \mathsf{+.f64}\left(\left(\frac{70711}{100000} \cdot \left(-1 \cdot x\right)\right), \left(\frac{\frac{230753}{100000} + x \cdot \frac{27061}{100000}}{\color{blue}{1 + x \cdot \left(\frac{99229}{100000} + x \cdot \frac{4481}{100000}\right)}} \cdot \frac{70711}{100000}\right)\right) \]
      7. associate-*r*N/A

        \[\leadsto \mathsf{+.f64}\left(\left(\left(\frac{70711}{100000} \cdot -1\right) \cdot x\right), \left(\color{blue}{\frac{\frac{230753}{100000} + x \cdot \frac{27061}{100000}}{1 + x \cdot \left(\frac{99229}{100000} + x \cdot \frac{4481}{100000}\right)}} \cdot \frac{70711}{100000}\right)\right) \]
      8. *-commutativeN/A

        \[\leadsto \mathsf{+.f64}\left(\left(x \cdot \left(\frac{70711}{100000} \cdot -1\right)\right), \left(\color{blue}{\frac{\frac{230753}{100000} + x \cdot \frac{27061}{100000}}{1 + x \cdot \left(\frac{99229}{100000} + x \cdot \frac{4481}{100000}\right)}} \cdot \frac{70711}{100000}\right)\right) \]
      9. *-lowering-*.f64N/A

        \[\leadsto \mathsf{+.f64}\left(\mathsf{*.f64}\left(x, \left(\frac{70711}{100000} \cdot -1\right)\right), \left(\color{blue}{\frac{\frac{230753}{100000} + x \cdot \frac{27061}{100000}}{1 + x \cdot \left(\frac{99229}{100000} + x \cdot \frac{4481}{100000}\right)}} \cdot \frac{70711}{100000}\right)\right) \]
      10. metadata-evalN/A

        \[\leadsto \mathsf{+.f64}\left(\mathsf{*.f64}\left(x, \frac{-70711}{100000}\right), \left(\frac{\frac{230753}{100000} + x \cdot \frac{27061}{100000}}{\color{blue}{1 + x \cdot \left(\frac{99229}{100000} + x \cdot \frac{4481}{100000}\right)}} \cdot \frac{70711}{100000}\right)\right) \]
      11. *-commutativeN/A

        \[\leadsto \mathsf{+.f64}\left(\mathsf{*.f64}\left(x, \frac{-70711}{100000}\right), \left(\frac{70711}{100000} \cdot \color{blue}{\frac{\frac{230753}{100000} + x \cdot \frac{27061}{100000}}{1 + x \cdot \left(\frac{99229}{100000} + x \cdot \frac{4481}{100000}\right)}}\right)\right) \]
      12. associate-*r/N/A

        \[\leadsto \mathsf{+.f64}\left(\mathsf{*.f64}\left(x, \frac{-70711}{100000}\right), \left(\frac{\frac{70711}{100000} \cdot \left(\frac{230753}{100000} + x \cdot \frac{27061}{100000}\right)}{\color{blue}{1 + x \cdot \left(\frac{99229}{100000} + x \cdot \frac{4481}{100000}\right)}}\right)\right) \]
      13. /-lowering-/.f64N/A

        \[\leadsto \mathsf{+.f64}\left(\mathsf{*.f64}\left(x, \frac{-70711}{100000}\right), \mathsf{/.f64}\left(\left(\frac{70711}{100000} \cdot \left(\frac{230753}{100000} + x \cdot \frac{27061}{100000}\right)\right), \color{blue}{\left(1 + x \cdot \left(\frac{99229}{100000} + x \cdot \frac{4481}{100000}\right)\right)}\right)\right) \]
    3. Simplified99.7%

      \[\leadsto \color{blue}{x \cdot -0.70711 + \frac{1.6316775383 + x \cdot 0.1913510371}{1 - x \cdot \left(-0.99229 + x \cdot -0.04481\right)}} \]
    4. Add Preprocessing
    5. Taylor expanded in x around inf

      \[\leadsto \mathsf{+.f64}\left(\mathsf{*.f64}\left(x, \frac{-70711}{100000}\right), \color{blue}{\left(\frac{\left(\frac{1913510371}{448100000} + \frac{\frac{335267464412236892}{281173802003125}}{{x}^{2}}\right) - \frac{3648757816023}{62748003125} \cdot \frac{1}{x}}{x}\right)}\right) \]
    6. Step-by-step derivation
      1. /-lowering-/.f64N/A

        \[\leadsto \mathsf{+.f64}\left(\mathsf{*.f64}\left(x, \frac{-70711}{100000}\right), \mathsf{/.f64}\left(\left(\left(\frac{1913510371}{448100000} + \frac{\frac{335267464412236892}{281173802003125}}{{x}^{2}}\right) - \frac{3648757816023}{62748003125} \cdot \frac{1}{x}\right), \color{blue}{x}\right)\right) \]
      2. associate--l+N/A

        \[\leadsto \mathsf{+.f64}\left(\mathsf{*.f64}\left(x, \frac{-70711}{100000}\right), \mathsf{/.f64}\left(\left(\frac{1913510371}{448100000} + \left(\frac{\frac{335267464412236892}{281173802003125}}{{x}^{2}} - \frac{3648757816023}{62748003125} \cdot \frac{1}{x}\right)\right), x\right)\right) \]
      3. unpow2N/A

        \[\leadsto \mathsf{+.f64}\left(\mathsf{*.f64}\left(x, \frac{-70711}{100000}\right), \mathsf{/.f64}\left(\left(\frac{1913510371}{448100000} + \left(\frac{\frac{335267464412236892}{281173802003125}}{x \cdot x} - \frac{3648757816023}{62748003125} \cdot \frac{1}{x}\right)\right), x\right)\right) \]
      4. associate-/r*N/A

        \[\leadsto \mathsf{+.f64}\left(\mathsf{*.f64}\left(x, \frac{-70711}{100000}\right), \mathsf{/.f64}\left(\left(\frac{1913510371}{448100000} + \left(\frac{\frac{\frac{335267464412236892}{281173802003125}}{x}}{x} - \frac{3648757816023}{62748003125} \cdot \frac{1}{x}\right)\right), x\right)\right) \]
      5. metadata-evalN/A

        \[\leadsto \mathsf{+.f64}\left(\mathsf{*.f64}\left(x, \frac{-70711}{100000}\right), \mathsf{/.f64}\left(\left(\frac{1913510371}{448100000} + \left(\frac{\frac{\frac{335267464412236892}{281173802003125} \cdot 1}{x}}{x} - \frac{3648757816023}{62748003125} \cdot \frac{1}{x}\right)\right), x\right)\right) \]
      6. associate-*r/N/A

        \[\leadsto \mathsf{+.f64}\left(\mathsf{*.f64}\left(x, \frac{-70711}{100000}\right), \mathsf{/.f64}\left(\left(\frac{1913510371}{448100000} + \left(\frac{\frac{335267464412236892}{281173802003125} \cdot \frac{1}{x}}{x} - \frac{3648757816023}{62748003125} \cdot \frac{1}{x}\right)\right), x\right)\right) \]
      7. associate-*r/N/A

        \[\leadsto \mathsf{+.f64}\left(\mathsf{*.f64}\left(x, \frac{-70711}{100000}\right), \mathsf{/.f64}\left(\left(\frac{1913510371}{448100000} + \left(\frac{\frac{335267464412236892}{281173802003125} \cdot \frac{1}{x}}{x} - \frac{\frac{3648757816023}{62748003125} \cdot 1}{x}\right)\right), x\right)\right) \]
      8. metadata-evalN/A

        \[\leadsto \mathsf{+.f64}\left(\mathsf{*.f64}\left(x, \frac{-70711}{100000}\right), \mathsf{/.f64}\left(\left(\frac{1913510371}{448100000} + \left(\frac{\frac{335267464412236892}{281173802003125} \cdot \frac{1}{x}}{x} - \frac{\frac{3648757816023}{62748003125}}{x}\right)\right), x\right)\right) \]
      9. div-subN/A

        \[\leadsto \mathsf{+.f64}\left(\mathsf{*.f64}\left(x, \frac{-70711}{100000}\right), \mathsf{/.f64}\left(\left(\frac{1913510371}{448100000} + \frac{\frac{335267464412236892}{281173802003125} \cdot \frac{1}{x} - \frac{3648757816023}{62748003125}}{x}\right), x\right)\right) \]
      10. +-lowering-+.f64N/A

        \[\leadsto \mathsf{+.f64}\left(\mathsf{*.f64}\left(x, \frac{-70711}{100000}\right), \mathsf{/.f64}\left(\mathsf{+.f64}\left(\frac{1913510371}{448100000}, \left(\frac{\frac{335267464412236892}{281173802003125} \cdot \frac{1}{x} - \frac{3648757816023}{62748003125}}{x}\right)\right), x\right)\right) \]
      11. /-lowering-/.f64N/A

        \[\leadsto \mathsf{+.f64}\left(\mathsf{*.f64}\left(x, \frac{-70711}{100000}\right), \mathsf{/.f64}\left(\mathsf{+.f64}\left(\frac{1913510371}{448100000}, \mathsf{/.f64}\left(\left(\frac{335267464412236892}{281173802003125} \cdot \frac{1}{x} - \frac{3648757816023}{62748003125}\right), x\right)\right), x\right)\right) \]
      12. sub-negN/A

        \[\leadsto \mathsf{+.f64}\left(\mathsf{*.f64}\left(x, \frac{-70711}{100000}\right), \mathsf{/.f64}\left(\mathsf{+.f64}\left(\frac{1913510371}{448100000}, \mathsf{/.f64}\left(\left(\frac{335267464412236892}{281173802003125} \cdot \frac{1}{x} + \left(\mathsf{neg}\left(\frac{3648757816023}{62748003125}\right)\right)\right), x\right)\right), x\right)\right) \]
      13. +-lowering-+.f64N/A

        \[\leadsto \mathsf{+.f64}\left(\mathsf{*.f64}\left(x, \frac{-70711}{100000}\right), \mathsf{/.f64}\left(\mathsf{+.f64}\left(\frac{1913510371}{448100000}, \mathsf{/.f64}\left(\mathsf{+.f64}\left(\left(\frac{335267464412236892}{281173802003125} \cdot \frac{1}{x}\right), \left(\mathsf{neg}\left(\frac{3648757816023}{62748003125}\right)\right)\right), x\right)\right), x\right)\right) \]
      14. associate-*r/N/A

        \[\leadsto \mathsf{+.f64}\left(\mathsf{*.f64}\left(x, \frac{-70711}{100000}\right), \mathsf{/.f64}\left(\mathsf{+.f64}\left(\frac{1913510371}{448100000}, \mathsf{/.f64}\left(\mathsf{+.f64}\left(\left(\frac{\frac{335267464412236892}{281173802003125} \cdot 1}{x}\right), \left(\mathsf{neg}\left(\frac{3648757816023}{62748003125}\right)\right)\right), x\right)\right), x\right)\right) \]
      15. metadata-evalN/A

        \[\leadsto \mathsf{+.f64}\left(\mathsf{*.f64}\left(x, \frac{-70711}{100000}\right), \mathsf{/.f64}\left(\mathsf{+.f64}\left(\frac{1913510371}{448100000}, \mathsf{/.f64}\left(\mathsf{+.f64}\left(\left(\frac{\frac{335267464412236892}{281173802003125}}{x}\right), \left(\mathsf{neg}\left(\frac{3648757816023}{62748003125}\right)\right)\right), x\right)\right), x\right)\right) \]
      16. /-lowering-/.f64N/A

        \[\leadsto \mathsf{+.f64}\left(\mathsf{*.f64}\left(x, \frac{-70711}{100000}\right), \mathsf{/.f64}\left(\mathsf{+.f64}\left(\frac{1913510371}{448100000}, \mathsf{/.f64}\left(\mathsf{+.f64}\left(\mathsf{/.f64}\left(\frac{335267464412236892}{281173802003125}, x\right), \left(\mathsf{neg}\left(\frac{3648757816023}{62748003125}\right)\right)\right), x\right)\right), x\right)\right) \]
      17. metadata-eval99.6%

        \[\leadsto \mathsf{+.f64}\left(\mathsf{*.f64}\left(x, \frac{-70711}{100000}\right), \mathsf{/.f64}\left(\mathsf{+.f64}\left(\frac{1913510371}{448100000}, \mathsf{/.f64}\left(\mathsf{+.f64}\left(\mathsf{/.f64}\left(\frac{335267464412236892}{281173802003125}, x\right), \frac{-3648757816023}{62748003125}\right), x\right)\right), x\right)\right) \]
    7. Simplified99.6%

      \[\leadsto x \cdot -0.70711 + \color{blue}{\frac{4.2702753202410175 + \frac{\frac{1192.3851440772235}{x} + -58.14938538768042}{x}}{x}} \]
  3. Recombined 3 regimes into one program.
  4. Add Preprocessing

Alternative 3: 99.3% accurate, 0.8× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq -1.05:\\ \;\;\;\;0.70711 \cdot \left(\frac{6.039053782637804}{x} - x\right)\\ \mathbf{elif}\;x \leq 2.2:\\ \;\;\;\;1.6316775383 + x \cdot \left(-2.134856267379707 + x \cdot \left(1.3436228731669864 + x \cdot -1.2692862305735844\right)\right)\\ \mathbf{else}:\\ \;\;\;\;x \cdot -0.70711 + \frac{4.2702753202410175 + \frac{-58.14938538768042}{x}}{x}\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (if (<= x -1.05)
   (* 0.70711 (- (/ 6.039053782637804 x) x))
   (if (<= x 2.2)
     (+
      1.6316775383
      (*
       x
       (+
        -2.134856267379707
        (* x (+ 1.3436228731669864 (* x -1.2692862305735844))))))
     (+
      (* x -0.70711)
      (/ (+ 4.2702753202410175 (/ -58.14938538768042 x)) x)))))
double code(double x) {
	double tmp;
	if (x <= -1.05) {
		tmp = 0.70711 * ((6.039053782637804 / x) - x);
	} else if (x <= 2.2) {
		tmp = 1.6316775383 + (x * (-2.134856267379707 + (x * (1.3436228731669864 + (x * -1.2692862305735844)))));
	} else {
		tmp = (x * -0.70711) + ((4.2702753202410175 + (-58.14938538768042 / x)) / x);
	}
	return tmp;
}
real(8) function code(x)
    real(8), intent (in) :: x
    real(8) :: tmp
    if (x <= (-1.05d0)) then
        tmp = 0.70711d0 * ((6.039053782637804d0 / x) - x)
    else if (x <= 2.2d0) then
        tmp = 1.6316775383d0 + (x * ((-2.134856267379707d0) + (x * (1.3436228731669864d0 + (x * (-1.2692862305735844d0))))))
    else
        tmp = (x * (-0.70711d0)) + ((4.2702753202410175d0 + ((-58.14938538768042d0) / x)) / x)
    end if
    code = tmp
end function
public static double code(double x) {
	double tmp;
	if (x <= -1.05) {
		tmp = 0.70711 * ((6.039053782637804 / x) - x);
	} else if (x <= 2.2) {
		tmp = 1.6316775383 + (x * (-2.134856267379707 + (x * (1.3436228731669864 + (x * -1.2692862305735844)))));
	} else {
		tmp = (x * -0.70711) + ((4.2702753202410175 + (-58.14938538768042 / x)) / x);
	}
	return tmp;
}
def code(x):
	tmp = 0
	if x <= -1.05:
		tmp = 0.70711 * ((6.039053782637804 / x) - x)
	elif x <= 2.2:
		tmp = 1.6316775383 + (x * (-2.134856267379707 + (x * (1.3436228731669864 + (x * -1.2692862305735844)))))
	else:
		tmp = (x * -0.70711) + ((4.2702753202410175 + (-58.14938538768042 / x)) / x)
	return tmp
function code(x)
	tmp = 0.0
	if (x <= -1.05)
		tmp = Float64(0.70711 * Float64(Float64(6.039053782637804 / x) - x));
	elseif (x <= 2.2)
		tmp = Float64(1.6316775383 + Float64(x * Float64(-2.134856267379707 + Float64(x * Float64(1.3436228731669864 + Float64(x * -1.2692862305735844))))));
	else
		tmp = Float64(Float64(x * -0.70711) + Float64(Float64(4.2702753202410175 + Float64(-58.14938538768042 / x)) / x));
	end
	return tmp
end
function tmp_2 = code(x)
	tmp = 0.0;
	if (x <= -1.05)
		tmp = 0.70711 * ((6.039053782637804 / x) - x);
	elseif (x <= 2.2)
		tmp = 1.6316775383 + (x * (-2.134856267379707 + (x * (1.3436228731669864 + (x * -1.2692862305735844)))));
	else
		tmp = (x * -0.70711) + ((4.2702753202410175 + (-58.14938538768042 / x)) / x);
	end
	tmp_2 = tmp;
end
code[x_] := If[LessEqual[x, -1.05], N[(0.70711 * N[(N[(6.039053782637804 / x), $MachinePrecision] - x), $MachinePrecision]), $MachinePrecision], If[LessEqual[x, 2.2], N[(1.6316775383 + N[(x * N[(-2.134856267379707 + N[(x * N[(1.3436228731669864 + N[(x * -1.2692862305735844), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(N[(x * -0.70711), $MachinePrecision] + N[(N[(4.2702753202410175 + N[(-58.14938538768042 / x), $MachinePrecision]), $MachinePrecision] / x), $MachinePrecision]), $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;x \leq -1.05:\\
\;\;\;\;0.70711 \cdot \left(\frac{6.039053782637804}{x} - x\right)\\

\mathbf{elif}\;x \leq 2.2:\\
\;\;\;\;1.6316775383 + x \cdot \left(-2.134856267379707 + x \cdot \left(1.3436228731669864 + x \cdot -1.2692862305735844\right)\right)\\

\mathbf{else}:\\
\;\;\;\;x \cdot -0.70711 + \frac{4.2702753202410175 + \frac{-58.14938538768042}{x}}{x}\\


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

    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. Add Preprocessing
    3. Taylor expanded in x around inf

      \[\leadsto \mathsf{*.f64}\left(\frac{70711}{100000}, \mathsf{\_.f64}\left(\color{blue}{\left(\frac{\frac{27061}{4481}}{x}\right)}, x\right)\right) \]
    4. Step-by-step derivation
      1. /-lowering-/.f6499.8%

        \[\leadsto \mathsf{*.f64}\left(\frac{70711}{100000}, \mathsf{\_.f64}\left(\mathsf{/.f64}\left(\frac{27061}{4481}, x\right), x\right)\right) \]
    5. Simplified99.8%

      \[\leadsto 0.70711 \cdot \left(\color{blue}{\frac{6.039053782637804}{x}} - x\right) \]

    if -1.05000000000000004 < x < 2.2000000000000002

    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. Add Preprocessing
    3. Taylor expanded in x around 0

      \[\leadsto \color{blue}{\frac{16316775383}{10000000000} + x \cdot \left(x \cdot \left(\frac{134362287316698645903}{100000000000000000000} + \frac{-12692862305735843227608787}{10000000000000000000000000} \cdot x\right) - \frac{2134856267379707}{1000000000000000}\right)} \]
    4. Step-by-step derivation
      1. +-lowering-+.f64N/A

        \[\leadsto \mathsf{+.f64}\left(\frac{16316775383}{10000000000}, \color{blue}{\left(x \cdot \left(x \cdot \left(\frac{134362287316698645903}{100000000000000000000} + \frac{-12692862305735843227608787}{10000000000000000000000000} \cdot x\right) - \frac{2134856267379707}{1000000000000000}\right)\right)}\right) \]
      2. *-lowering-*.f64N/A

        \[\leadsto \mathsf{+.f64}\left(\frac{16316775383}{10000000000}, \mathsf{*.f64}\left(x, \color{blue}{\left(x \cdot \left(\frac{134362287316698645903}{100000000000000000000} + \frac{-12692862305735843227608787}{10000000000000000000000000} \cdot x\right) - \frac{2134856267379707}{1000000000000000}\right)}\right)\right) \]
      3. sub-negN/A

        \[\leadsto \mathsf{+.f64}\left(\frac{16316775383}{10000000000}, \mathsf{*.f64}\left(x, \left(x \cdot \left(\frac{134362287316698645903}{100000000000000000000} + \frac{-12692862305735843227608787}{10000000000000000000000000} \cdot x\right) + \color{blue}{\left(\mathsf{neg}\left(\frac{2134856267379707}{1000000000000000}\right)\right)}\right)\right)\right) \]
      4. metadata-evalN/A

        \[\leadsto \mathsf{+.f64}\left(\frac{16316775383}{10000000000}, \mathsf{*.f64}\left(x, \left(x \cdot \left(\frac{134362287316698645903}{100000000000000000000} + \frac{-12692862305735843227608787}{10000000000000000000000000} \cdot x\right) + \frac{-2134856267379707}{1000000000000000}\right)\right)\right) \]
      5. +-commutativeN/A

        \[\leadsto \mathsf{+.f64}\left(\frac{16316775383}{10000000000}, \mathsf{*.f64}\left(x, \left(\frac{-2134856267379707}{1000000000000000} + \color{blue}{x \cdot \left(\frac{134362287316698645903}{100000000000000000000} + \frac{-12692862305735843227608787}{10000000000000000000000000} \cdot x\right)}\right)\right)\right) \]
      6. +-lowering-+.f64N/A

        \[\leadsto \mathsf{+.f64}\left(\frac{16316775383}{10000000000}, \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(\frac{-2134856267379707}{1000000000000000}, \color{blue}{\left(x \cdot \left(\frac{134362287316698645903}{100000000000000000000} + \frac{-12692862305735843227608787}{10000000000000000000000000} \cdot x\right)\right)}\right)\right)\right) \]
      7. *-lowering-*.f64N/A

        \[\leadsto \mathsf{+.f64}\left(\frac{16316775383}{10000000000}, \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(\frac{-2134856267379707}{1000000000000000}, \mathsf{*.f64}\left(x, \color{blue}{\left(\frac{134362287316698645903}{100000000000000000000} + \frac{-12692862305735843227608787}{10000000000000000000000000} \cdot x\right)}\right)\right)\right)\right) \]
      8. +-lowering-+.f64N/A

        \[\leadsto \mathsf{+.f64}\left(\frac{16316775383}{10000000000}, \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(\frac{-2134856267379707}{1000000000000000}, \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(\frac{134362287316698645903}{100000000000000000000}, \color{blue}{\left(\frac{-12692862305735843227608787}{10000000000000000000000000} \cdot x\right)}\right)\right)\right)\right)\right) \]
      9. *-commutativeN/A

        \[\leadsto \mathsf{+.f64}\left(\frac{16316775383}{10000000000}, \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(\frac{-2134856267379707}{1000000000000000}, \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(\frac{134362287316698645903}{100000000000000000000}, \left(x \cdot \color{blue}{\frac{-12692862305735843227608787}{10000000000000000000000000}}\right)\right)\right)\right)\right)\right) \]
      10. *-lowering-*.f6499.5%

        \[\leadsto \mathsf{+.f64}\left(\frac{16316775383}{10000000000}, \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(\frac{-2134856267379707}{1000000000000000}, \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(\frac{134362287316698645903}{100000000000000000000}, \mathsf{*.f64}\left(x, \color{blue}{\frac{-12692862305735843227608787}{10000000000000000000000000}}\right)\right)\right)\right)\right)\right) \]
    5. Simplified99.5%

      \[\leadsto \color{blue}{1.6316775383 + x \cdot \left(-2.134856267379707 + x \cdot \left(1.3436228731669864 + x \cdot -1.2692862305735844\right)\right)} \]

    if 2.2000000000000002 < 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-negN/A

        \[\leadsto \frac{70711}{100000} \cdot \left(\frac{\frac{230753}{100000} + x \cdot \frac{27061}{100000}}{1 + x \cdot \left(\frac{99229}{100000} + x \cdot \frac{4481}{100000}\right)} + \color{blue}{\left(\mathsf{neg}\left(x\right)\right)}\right) \]
      2. +-commutativeN/A

        \[\leadsto \frac{70711}{100000} \cdot \left(\left(\mathsf{neg}\left(x\right)\right) + \color{blue}{\frac{\frac{230753}{100000} + x \cdot \frac{27061}{100000}}{1 + x \cdot \left(\frac{99229}{100000} + x \cdot \frac{4481}{100000}\right)}}\right) \]
      3. distribute-lft-inN/A

        \[\leadsto \frac{70711}{100000} \cdot \left(\mathsf{neg}\left(x\right)\right) + \color{blue}{\frac{70711}{100000} \cdot \frac{\frac{230753}{100000} + x \cdot \frac{27061}{100000}}{1 + x \cdot \left(\frac{99229}{100000} + x \cdot \frac{4481}{100000}\right)}} \]
      4. *-commutativeN/A

        \[\leadsto \frac{70711}{100000} \cdot \left(\mathsf{neg}\left(x\right)\right) + \frac{\frac{230753}{100000} + x \cdot \frac{27061}{100000}}{1 + x \cdot \left(\frac{99229}{100000} + x \cdot \frac{4481}{100000}\right)} \cdot \color{blue}{\frac{70711}{100000}} \]
      5. +-lowering-+.f64N/A

        \[\leadsto \mathsf{+.f64}\left(\left(\frac{70711}{100000} \cdot \left(\mathsf{neg}\left(x\right)\right)\right), \color{blue}{\left(\frac{\frac{230753}{100000} + x \cdot \frac{27061}{100000}}{1 + x \cdot \left(\frac{99229}{100000} + x \cdot \frac{4481}{100000}\right)} \cdot \frac{70711}{100000}\right)}\right) \]
      6. neg-mul-1N/A

        \[\leadsto \mathsf{+.f64}\left(\left(\frac{70711}{100000} \cdot \left(-1 \cdot x\right)\right), \left(\frac{\frac{230753}{100000} + x \cdot \frac{27061}{100000}}{\color{blue}{1 + x \cdot \left(\frac{99229}{100000} + x \cdot \frac{4481}{100000}\right)}} \cdot \frac{70711}{100000}\right)\right) \]
      7. associate-*r*N/A

        \[\leadsto \mathsf{+.f64}\left(\left(\left(\frac{70711}{100000} \cdot -1\right) \cdot x\right), \left(\color{blue}{\frac{\frac{230753}{100000} + x \cdot \frac{27061}{100000}}{1 + x \cdot \left(\frac{99229}{100000} + x \cdot \frac{4481}{100000}\right)}} \cdot \frac{70711}{100000}\right)\right) \]
      8. *-commutativeN/A

        \[\leadsto \mathsf{+.f64}\left(\left(x \cdot \left(\frac{70711}{100000} \cdot -1\right)\right), \left(\color{blue}{\frac{\frac{230753}{100000} + x \cdot \frac{27061}{100000}}{1 + x \cdot \left(\frac{99229}{100000} + x \cdot \frac{4481}{100000}\right)}} \cdot \frac{70711}{100000}\right)\right) \]
      9. *-lowering-*.f64N/A

        \[\leadsto \mathsf{+.f64}\left(\mathsf{*.f64}\left(x, \left(\frac{70711}{100000} \cdot -1\right)\right), \left(\color{blue}{\frac{\frac{230753}{100000} + x \cdot \frac{27061}{100000}}{1 + x \cdot \left(\frac{99229}{100000} + x \cdot \frac{4481}{100000}\right)}} \cdot \frac{70711}{100000}\right)\right) \]
      10. metadata-evalN/A

        \[\leadsto \mathsf{+.f64}\left(\mathsf{*.f64}\left(x, \frac{-70711}{100000}\right), \left(\frac{\frac{230753}{100000} + x \cdot \frac{27061}{100000}}{\color{blue}{1 + x \cdot \left(\frac{99229}{100000} + x \cdot \frac{4481}{100000}\right)}} \cdot \frac{70711}{100000}\right)\right) \]
      11. *-commutativeN/A

        \[\leadsto \mathsf{+.f64}\left(\mathsf{*.f64}\left(x, \frac{-70711}{100000}\right), \left(\frac{70711}{100000} \cdot \color{blue}{\frac{\frac{230753}{100000} + x \cdot \frac{27061}{100000}}{1 + x \cdot \left(\frac{99229}{100000} + x \cdot \frac{4481}{100000}\right)}}\right)\right) \]
      12. associate-*r/N/A

        \[\leadsto \mathsf{+.f64}\left(\mathsf{*.f64}\left(x, \frac{-70711}{100000}\right), \left(\frac{\frac{70711}{100000} \cdot \left(\frac{230753}{100000} + x \cdot \frac{27061}{100000}\right)}{\color{blue}{1 + x \cdot \left(\frac{99229}{100000} + x \cdot \frac{4481}{100000}\right)}}\right)\right) \]
      13. /-lowering-/.f64N/A

        \[\leadsto \mathsf{+.f64}\left(\mathsf{*.f64}\left(x, \frac{-70711}{100000}\right), \mathsf{/.f64}\left(\left(\frac{70711}{100000} \cdot \left(\frac{230753}{100000} + x \cdot \frac{27061}{100000}\right)\right), \color{blue}{\left(1 + x \cdot \left(\frac{99229}{100000} + x \cdot \frac{4481}{100000}\right)\right)}\right)\right) \]
    3. Simplified99.7%

      \[\leadsto \color{blue}{x \cdot -0.70711 + \frac{1.6316775383 + x \cdot 0.1913510371}{1 - x \cdot \left(-0.99229 + x \cdot -0.04481\right)}} \]
    4. Add Preprocessing
    5. Taylor expanded in x around inf

      \[\leadsto \mathsf{+.f64}\left(\mathsf{*.f64}\left(x, \frac{-70711}{100000}\right), \color{blue}{\left(\frac{\frac{1913510371}{448100000} - \frac{3648757816023}{62748003125} \cdot \frac{1}{x}}{x}\right)}\right) \]
    6. Step-by-step derivation
      1. /-lowering-/.f64N/A

        \[\leadsto \mathsf{+.f64}\left(\mathsf{*.f64}\left(x, \frac{-70711}{100000}\right), \mathsf{/.f64}\left(\left(\frac{1913510371}{448100000} - \frac{3648757816023}{62748003125} \cdot \frac{1}{x}\right), \color{blue}{x}\right)\right) \]
      2. sub-negN/A

        \[\leadsto \mathsf{+.f64}\left(\mathsf{*.f64}\left(x, \frac{-70711}{100000}\right), \mathsf{/.f64}\left(\left(\frac{1913510371}{448100000} + \left(\mathsf{neg}\left(\frac{3648757816023}{62748003125} \cdot \frac{1}{x}\right)\right)\right), x\right)\right) \]
      3. +-lowering-+.f64N/A

        \[\leadsto \mathsf{+.f64}\left(\mathsf{*.f64}\left(x, \frac{-70711}{100000}\right), \mathsf{/.f64}\left(\mathsf{+.f64}\left(\frac{1913510371}{448100000}, \left(\mathsf{neg}\left(\frac{3648757816023}{62748003125} \cdot \frac{1}{x}\right)\right)\right), x\right)\right) \]
      4. associate-*r/N/A

        \[\leadsto \mathsf{+.f64}\left(\mathsf{*.f64}\left(x, \frac{-70711}{100000}\right), \mathsf{/.f64}\left(\mathsf{+.f64}\left(\frac{1913510371}{448100000}, \left(\mathsf{neg}\left(\frac{\frac{3648757816023}{62748003125} \cdot 1}{x}\right)\right)\right), x\right)\right) \]
      5. metadata-evalN/A

        \[\leadsto \mathsf{+.f64}\left(\mathsf{*.f64}\left(x, \frac{-70711}{100000}\right), \mathsf{/.f64}\left(\mathsf{+.f64}\left(\frac{1913510371}{448100000}, \left(\mathsf{neg}\left(\frac{\frac{3648757816023}{62748003125}}{x}\right)\right)\right), x\right)\right) \]
      6. distribute-neg-fracN/A

        \[\leadsto \mathsf{+.f64}\left(\mathsf{*.f64}\left(x, \frac{-70711}{100000}\right), \mathsf{/.f64}\left(\mathsf{+.f64}\left(\frac{1913510371}{448100000}, \left(\frac{\mathsf{neg}\left(\frac{3648757816023}{62748003125}\right)}{x}\right)\right), x\right)\right) \]
      7. /-lowering-/.f64N/A

        \[\leadsto \mathsf{+.f64}\left(\mathsf{*.f64}\left(x, \frac{-70711}{100000}\right), \mathsf{/.f64}\left(\mathsf{+.f64}\left(\frac{1913510371}{448100000}, \mathsf{/.f64}\left(\left(\mathsf{neg}\left(\frac{3648757816023}{62748003125}\right)\right), x\right)\right), x\right)\right) \]
      8. metadata-eval99.4%

        \[\leadsto \mathsf{+.f64}\left(\mathsf{*.f64}\left(x, \frac{-70711}{100000}\right), \mathsf{/.f64}\left(\mathsf{+.f64}\left(\frac{1913510371}{448100000}, \mathsf{/.f64}\left(\frac{-3648757816023}{62748003125}, x\right)\right), x\right)\right) \]
    7. Simplified99.4%

      \[\leadsto x \cdot -0.70711 + \color{blue}{\frac{4.2702753202410175 + \frac{-58.14938538768042}{x}}{x}} \]
  3. Recombined 3 regimes into one program.
  4. Add Preprocessing

Alternative 4: 99.2% accurate, 0.9× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq -1.05:\\ \;\;\;\;0.70711 \cdot \left(\frac{6.039053782637804}{x} - x\right)\\ \mathbf{elif}\;x \leq 1.15:\\ \;\;\;\;1.6316775383 + x \cdot \left(-2.134856267379707 + x \cdot 1.3436228731669864\right)\\ \mathbf{else}:\\ \;\;\;\;x \cdot -0.70711 + \frac{4.2702753202410175 + \frac{-58.14938538768042}{x}}{x}\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (if (<= x -1.05)
   (* 0.70711 (- (/ 6.039053782637804 x) x))
   (if (<= x 1.15)
     (+ 1.6316775383 (* x (+ -2.134856267379707 (* x 1.3436228731669864))))
     (+
      (* x -0.70711)
      (/ (+ 4.2702753202410175 (/ -58.14938538768042 x)) x)))))
double code(double x) {
	double tmp;
	if (x <= -1.05) {
		tmp = 0.70711 * ((6.039053782637804 / x) - x);
	} else if (x <= 1.15) {
		tmp = 1.6316775383 + (x * (-2.134856267379707 + (x * 1.3436228731669864)));
	} else {
		tmp = (x * -0.70711) + ((4.2702753202410175 + (-58.14938538768042 / x)) / x);
	}
	return tmp;
}
real(8) function code(x)
    real(8), intent (in) :: x
    real(8) :: tmp
    if (x <= (-1.05d0)) then
        tmp = 0.70711d0 * ((6.039053782637804d0 / x) - x)
    else if (x <= 1.15d0) then
        tmp = 1.6316775383d0 + (x * ((-2.134856267379707d0) + (x * 1.3436228731669864d0)))
    else
        tmp = (x * (-0.70711d0)) + ((4.2702753202410175d0 + ((-58.14938538768042d0) / x)) / x)
    end if
    code = tmp
end function
public static double code(double x) {
	double tmp;
	if (x <= -1.05) {
		tmp = 0.70711 * ((6.039053782637804 / x) - x);
	} else if (x <= 1.15) {
		tmp = 1.6316775383 + (x * (-2.134856267379707 + (x * 1.3436228731669864)));
	} else {
		tmp = (x * -0.70711) + ((4.2702753202410175 + (-58.14938538768042 / x)) / x);
	}
	return tmp;
}
def code(x):
	tmp = 0
	if x <= -1.05:
		tmp = 0.70711 * ((6.039053782637804 / x) - x)
	elif x <= 1.15:
		tmp = 1.6316775383 + (x * (-2.134856267379707 + (x * 1.3436228731669864)))
	else:
		tmp = (x * -0.70711) + ((4.2702753202410175 + (-58.14938538768042 / x)) / x)
	return tmp
function code(x)
	tmp = 0.0
	if (x <= -1.05)
		tmp = Float64(0.70711 * Float64(Float64(6.039053782637804 / x) - x));
	elseif (x <= 1.15)
		tmp = Float64(1.6316775383 + Float64(x * Float64(-2.134856267379707 + Float64(x * 1.3436228731669864))));
	else
		tmp = Float64(Float64(x * -0.70711) + Float64(Float64(4.2702753202410175 + Float64(-58.14938538768042 / x)) / x));
	end
	return tmp
end
function tmp_2 = code(x)
	tmp = 0.0;
	if (x <= -1.05)
		tmp = 0.70711 * ((6.039053782637804 / x) - x);
	elseif (x <= 1.15)
		tmp = 1.6316775383 + (x * (-2.134856267379707 + (x * 1.3436228731669864)));
	else
		tmp = (x * -0.70711) + ((4.2702753202410175 + (-58.14938538768042 / x)) / x);
	end
	tmp_2 = tmp;
end
code[x_] := If[LessEqual[x, -1.05], N[(0.70711 * N[(N[(6.039053782637804 / x), $MachinePrecision] - x), $MachinePrecision]), $MachinePrecision], If[LessEqual[x, 1.15], N[(1.6316775383 + N[(x * N[(-2.134856267379707 + N[(x * 1.3436228731669864), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(N[(x * -0.70711), $MachinePrecision] + N[(N[(4.2702753202410175 + N[(-58.14938538768042 / x), $MachinePrecision]), $MachinePrecision] / x), $MachinePrecision]), $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;x \leq -1.05:\\
\;\;\;\;0.70711 \cdot \left(\frac{6.039053782637804}{x} - x\right)\\

\mathbf{elif}\;x \leq 1.15:\\
\;\;\;\;1.6316775383 + x \cdot \left(-2.134856267379707 + x \cdot 1.3436228731669864\right)\\

\mathbf{else}:\\
\;\;\;\;x \cdot -0.70711 + \frac{4.2702753202410175 + \frac{-58.14938538768042}{x}}{x}\\


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

    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. Add Preprocessing
    3. Taylor expanded in x around inf

      \[\leadsto \mathsf{*.f64}\left(\frac{70711}{100000}, \mathsf{\_.f64}\left(\color{blue}{\left(\frac{\frac{27061}{4481}}{x}\right)}, x\right)\right) \]
    4. Step-by-step derivation
      1. /-lowering-/.f6499.8%

        \[\leadsto \mathsf{*.f64}\left(\frac{70711}{100000}, \mathsf{\_.f64}\left(\mathsf{/.f64}\left(\frac{27061}{4481}, x\right), x\right)\right) \]
    5. Simplified99.8%

      \[\leadsto 0.70711 \cdot \left(\color{blue}{\frac{6.039053782637804}{x}} - x\right) \]

    if -1.05000000000000004 < x < 1.1499999999999999

    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. Add Preprocessing
    3. Taylor expanded in x around 0

      \[\leadsto \color{blue}{\frac{16316775383}{10000000000} + x \cdot \left(\frac{134362287316698645903}{100000000000000000000} \cdot x - \frac{2134856267379707}{1000000000000000}\right)} \]
    4. Step-by-step derivation
      1. +-lowering-+.f64N/A

        \[\leadsto \mathsf{+.f64}\left(\frac{16316775383}{10000000000}, \color{blue}{\left(x \cdot \left(\frac{134362287316698645903}{100000000000000000000} \cdot x - \frac{2134856267379707}{1000000000000000}\right)\right)}\right) \]
      2. *-lowering-*.f64N/A

        \[\leadsto \mathsf{+.f64}\left(\frac{16316775383}{10000000000}, \mathsf{*.f64}\left(x, \color{blue}{\left(\frac{134362287316698645903}{100000000000000000000} \cdot x - \frac{2134856267379707}{1000000000000000}\right)}\right)\right) \]
      3. sub-negN/A

        \[\leadsto \mathsf{+.f64}\left(\frac{16316775383}{10000000000}, \mathsf{*.f64}\left(x, \left(\frac{134362287316698645903}{100000000000000000000} \cdot x + \color{blue}{\left(\mathsf{neg}\left(\frac{2134856267379707}{1000000000000000}\right)\right)}\right)\right)\right) \]
      4. metadata-evalN/A

        \[\leadsto \mathsf{+.f64}\left(\frac{16316775383}{10000000000}, \mathsf{*.f64}\left(x, \left(\frac{134362287316698645903}{100000000000000000000} \cdot x + \frac{-2134856267379707}{1000000000000000}\right)\right)\right) \]
      5. +-commutativeN/A

        \[\leadsto \mathsf{+.f64}\left(\frac{16316775383}{10000000000}, \mathsf{*.f64}\left(x, \left(\frac{-2134856267379707}{1000000000000000} + \color{blue}{\frac{134362287316698645903}{100000000000000000000} \cdot x}\right)\right)\right) \]
      6. +-lowering-+.f64N/A

        \[\leadsto \mathsf{+.f64}\left(\frac{16316775383}{10000000000}, \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(\frac{-2134856267379707}{1000000000000000}, \color{blue}{\left(\frac{134362287316698645903}{100000000000000000000} \cdot x\right)}\right)\right)\right) \]
      7. *-commutativeN/A

        \[\leadsto \mathsf{+.f64}\left(\frac{16316775383}{10000000000}, \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(\frac{-2134856267379707}{1000000000000000}, \left(x \cdot \color{blue}{\frac{134362287316698645903}{100000000000000000000}}\right)\right)\right)\right) \]
      8. *-lowering-*.f6499.3%

        \[\leadsto \mathsf{+.f64}\left(\frac{16316775383}{10000000000}, \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(\frac{-2134856267379707}{1000000000000000}, \mathsf{*.f64}\left(x, \color{blue}{\frac{134362287316698645903}{100000000000000000000}}\right)\right)\right)\right) \]
    5. Simplified99.3%

      \[\leadsto \color{blue}{1.6316775383 + x \cdot \left(-2.134856267379707 + x \cdot 1.3436228731669864\right)} \]

    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-negN/A

        \[\leadsto \frac{70711}{100000} \cdot \left(\frac{\frac{230753}{100000} + x \cdot \frac{27061}{100000}}{1 + x \cdot \left(\frac{99229}{100000} + x \cdot \frac{4481}{100000}\right)} + \color{blue}{\left(\mathsf{neg}\left(x\right)\right)}\right) \]
      2. +-commutativeN/A

        \[\leadsto \frac{70711}{100000} \cdot \left(\left(\mathsf{neg}\left(x\right)\right) + \color{blue}{\frac{\frac{230753}{100000} + x \cdot \frac{27061}{100000}}{1 + x \cdot \left(\frac{99229}{100000} + x \cdot \frac{4481}{100000}\right)}}\right) \]
      3. distribute-lft-inN/A

        \[\leadsto \frac{70711}{100000} \cdot \left(\mathsf{neg}\left(x\right)\right) + \color{blue}{\frac{70711}{100000} \cdot \frac{\frac{230753}{100000} + x \cdot \frac{27061}{100000}}{1 + x \cdot \left(\frac{99229}{100000} + x \cdot \frac{4481}{100000}\right)}} \]
      4. *-commutativeN/A

        \[\leadsto \frac{70711}{100000} \cdot \left(\mathsf{neg}\left(x\right)\right) + \frac{\frac{230753}{100000} + x \cdot \frac{27061}{100000}}{1 + x \cdot \left(\frac{99229}{100000} + x \cdot \frac{4481}{100000}\right)} \cdot \color{blue}{\frac{70711}{100000}} \]
      5. +-lowering-+.f64N/A

        \[\leadsto \mathsf{+.f64}\left(\left(\frac{70711}{100000} \cdot \left(\mathsf{neg}\left(x\right)\right)\right), \color{blue}{\left(\frac{\frac{230753}{100000} + x \cdot \frac{27061}{100000}}{1 + x \cdot \left(\frac{99229}{100000} + x \cdot \frac{4481}{100000}\right)} \cdot \frac{70711}{100000}\right)}\right) \]
      6. neg-mul-1N/A

        \[\leadsto \mathsf{+.f64}\left(\left(\frac{70711}{100000} \cdot \left(-1 \cdot x\right)\right), \left(\frac{\frac{230753}{100000} + x \cdot \frac{27061}{100000}}{\color{blue}{1 + x \cdot \left(\frac{99229}{100000} + x \cdot \frac{4481}{100000}\right)}} \cdot \frac{70711}{100000}\right)\right) \]
      7. associate-*r*N/A

        \[\leadsto \mathsf{+.f64}\left(\left(\left(\frac{70711}{100000} \cdot -1\right) \cdot x\right), \left(\color{blue}{\frac{\frac{230753}{100000} + x \cdot \frac{27061}{100000}}{1 + x \cdot \left(\frac{99229}{100000} + x \cdot \frac{4481}{100000}\right)}} \cdot \frac{70711}{100000}\right)\right) \]
      8. *-commutativeN/A

        \[\leadsto \mathsf{+.f64}\left(\left(x \cdot \left(\frac{70711}{100000} \cdot -1\right)\right), \left(\color{blue}{\frac{\frac{230753}{100000} + x \cdot \frac{27061}{100000}}{1 + x \cdot \left(\frac{99229}{100000} + x \cdot \frac{4481}{100000}\right)}} \cdot \frac{70711}{100000}\right)\right) \]
      9. *-lowering-*.f64N/A

        \[\leadsto \mathsf{+.f64}\left(\mathsf{*.f64}\left(x, \left(\frac{70711}{100000} \cdot -1\right)\right), \left(\color{blue}{\frac{\frac{230753}{100000} + x \cdot \frac{27061}{100000}}{1 + x \cdot \left(\frac{99229}{100000} + x \cdot \frac{4481}{100000}\right)}} \cdot \frac{70711}{100000}\right)\right) \]
      10. metadata-evalN/A

        \[\leadsto \mathsf{+.f64}\left(\mathsf{*.f64}\left(x, \frac{-70711}{100000}\right), \left(\frac{\frac{230753}{100000} + x \cdot \frac{27061}{100000}}{\color{blue}{1 + x \cdot \left(\frac{99229}{100000} + x \cdot \frac{4481}{100000}\right)}} \cdot \frac{70711}{100000}\right)\right) \]
      11. *-commutativeN/A

        \[\leadsto \mathsf{+.f64}\left(\mathsf{*.f64}\left(x, \frac{-70711}{100000}\right), \left(\frac{70711}{100000} \cdot \color{blue}{\frac{\frac{230753}{100000} + x \cdot \frac{27061}{100000}}{1 + x \cdot \left(\frac{99229}{100000} + x \cdot \frac{4481}{100000}\right)}}\right)\right) \]
      12. associate-*r/N/A

        \[\leadsto \mathsf{+.f64}\left(\mathsf{*.f64}\left(x, \frac{-70711}{100000}\right), \left(\frac{\frac{70711}{100000} \cdot \left(\frac{230753}{100000} + x \cdot \frac{27061}{100000}\right)}{\color{blue}{1 + x \cdot \left(\frac{99229}{100000} + x \cdot \frac{4481}{100000}\right)}}\right)\right) \]
      13. /-lowering-/.f64N/A

        \[\leadsto \mathsf{+.f64}\left(\mathsf{*.f64}\left(x, \frac{-70711}{100000}\right), \mathsf{/.f64}\left(\left(\frac{70711}{100000} \cdot \left(\frac{230753}{100000} + x \cdot \frac{27061}{100000}\right)\right), \color{blue}{\left(1 + x \cdot \left(\frac{99229}{100000} + x \cdot \frac{4481}{100000}\right)\right)}\right)\right) \]
    3. Simplified99.7%

      \[\leadsto \color{blue}{x \cdot -0.70711 + \frac{1.6316775383 + x \cdot 0.1913510371}{1 - x \cdot \left(-0.99229 + x \cdot -0.04481\right)}} \]
    4. Add Preprocessing
    5. Taylor expanded in x around inf

      \[\leadsto \mathsf{+.f64}\left(\mathsf{*.f64}\left(x, \frac{-70711}{100000}\right), \color{blue}{\left(\frac{\frac{1913510371}{448100000} - \frac{3648757816023}{62748003125} \cdot \frac{1}{x}}{x}\right)}\right) \]
    6. Step-by-step derivation
      1. /-lowering-/.f64N/A

        \[\leadsto \mathsf{+.f64}\left(\mathsf{*.f64}\left(x, \frac{-70711}{100000}\right), \mathsf{/.f64}\left(\left(\frac{1913510371}{448100000} - \frac{3648757816023}{62748003125} \cdot \frac{1}{x}\right), \color{blue}{x}\right)\right) \]
      2. sub-negN/A

        \[\leadsto \mathsf{+.f64}\left(\mathsf{*.f64}\left(x, \frac{-70711}{100000}\right), \mathsf{/.f64}\left(\left(\frac{1913510371}{448100000} + \left(\mathsf{neg}\left(\frac{3648757816023}{62748003125} \cdot \frac{1}{x}\right)\right)\right), x\right)\right) \]
      3. +-lowering-+.f64N/A

        \[\leadsto \mathsf{+.f64}\left(\mathsf{*.f64}\left(x, \frac{-70711}{100000}\right), \mathsf{/.f64}\left(\mathsf{+.f64}\left(\frac{1913510371}{448100000}, \left(\mathsf{neg}\left(\frac{3648757816023}{62748003125} \cdot \frac{1}{x}\right)\right)\right), x\right)\right) \]
      4. associate-*r/N/A

        \[\leadsto \mathsf{+.f64}\left(\mathsf{*.f64}\left(x, \frac{-70711}{100000}\right), \mathsf{/.f64}\left(\mathsf{+.f64}\left(\frac{1913510371}{448100000}, \left(\mathsf{neg}\left(\frac{\frac{3648757816023}{62748003125} \cdot 1}{x}\right)\right)\right), x\right)\right) \]
      5. metadata-evalN/A

        \[\leadsto \mathsf{+.f64}\left(\mathsf{*.f64}\left(x, \frac{-70711}{100000}\right), \mathsf{/.f64}\left(\mathsf{+.f64}\left(\frac{1913510371}{448100000}, \left(\mathsf{neg}\left(\frac{\frac{3648757816023}{62748003125}}{x}\right)\right)\right), x\right)\right) \]
      6. distribute-neg-fracN/A

        \[\leadsto \mathsf{+.f64}\left(\mathsf{*.f64}\left(x, \frac{-70711}{100000}\right), \mathsf{/.f64}\left(\mathsf{+.f64}\left(\frac{1913510371}{448100000}, \left(\frac{\mathsf{neg}\left(\frac{3648757816023}{62748003125}\right)}{x}\right)\right), x\right)\right) \]
      7. /-lowering-/.f64N/A

        \[\leadsto \mathsf{+.f64}\left(\mathsf{*.f64}\left(x, \frac{-70711}{100000}\right), \mathsf{/.f64}\left(\mathsf{+.f64}\left(\frac{1913510371}{448100000}, \mathsf{/.f64}\left(\left(\mathsf{neg}\left(\frac{3648757816023}{62748003125}\right)\right), x\right)\right), x\right)\right) \]
      8. metadata-eval99.4%

        \[\leadsto \mathsf{+.f64}\left(\mathsf{*.f64}\left(x, \frac{-70711}{100000}\right), \mathsf{/.f64}\left(\mathsf{+.f64}\left(\frac{1913510371}{448100000}, \mathsf{/.f64}\left(\frac{-3648757816023}{62748003125}, x\right)\right), x\right)\right) \]
    7. Simplified99.4%

      \[\leadsto x \cdot -0.70711 + \color{blue}{\frac{4.2702753202410175 + \frac{-58.14938538768042}{x}}{x}} \]
  3. Recombined 3 regimes into one program.
  4. Add Preprocessing

Alternative 5: 99.2% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := 0.70711 \cdot \left(\frac{6.039053782637804}{x} - x\right)\\ \mathbf{if}\;x \leq -1.05:\\ \;\;\;\;t\_0\\ \mathbf{elif}\;x \leq 1.55:\\ \;\;\;\;1.6316775383 + x \cdot \left(-2.134856267379707 + x \cdot 1.3436228731669864\right)\\ \mathbf{else}:\\ \;\;\;\;t\_0\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (let* ((t_0 (* 0.70711 (- (/ 6.039053782637804 x) x))))
   (if (<= x -1.05)
     t_0
     (if (<= x 1.55)
       (+ 1.6316775383 (* x (+ -2.134856267379707 (* x 1.3436228731669864))))
       t_0))))
double code(double x) {
	double t_0 = 0.70711 * ((6.039053782637804 / x) - x);
	double tmp;
	if (x <= -1.05) {
		tmp = t_0;
	} else if (x <= 1.55) {
		tmp = 1.6316775383 + (x * (-2.134856267379707 + (x * 1.3436228731669864)));
	} else {
		tmp = t_0;
	}
	return tmp;
}
real(8) function code(x)
    real(8), intent (in) :: x
    real(8) :: t_0
    real(8) :: tmp
    t_0 = 0.70711d0 * ((6.039053782637804d0 / x) - x)
    if (x <= (-1.05d0)) then
        tmp = t_0
    else if (x <= 1.55d0) then
        tmp = 1.6316775383d0 + (x * ((-2.134856267379707d0) + (x * 1.3436228731669864d0)))
    else
        tmp = t_0
    end if
    code = tmp
end function
public static double code(double x) {
	double t_0 = 0.70711 * ((6.039053782637804 / x) - x);
	double tmp;
	if (x <= -1.05) {
		tmp = t_0;
	} else if (x <= 1.55) {
		tmp = 1.6316775383 + (x * (-2.134856267379707 + (x * 1.3436228731669864)));
	} else {
		tmp = t_0;
	}
	return tmp;
}
def code(x):
	t_0 = 0.70711 * ((6.039053782637804 / x) - x)
	tmp = 0
	if x <= -1.05:
		tmp = t_0
	elif x <= 1.55:
		tmp = 1.6316775383 + (x * (-2.134856267379707 + (x * 1.3436228731669864)))
	else:
		tmp = t_0
	return tmp
function code(x)
	t_0 = Float64(0.70711 * Float64(Float64(6.039053782637804 / x) - x))
	tmp = 0.0
	if (x <= -1.05)
		tmp = t_0;
	elseif (x <= 1.55)
		tmp = Float64(1.6316775383 + Float64(x * Float64(-2.134856267379707 + Float64(x * 1.3436228731669864))));
	else
		tmp = t_0;
	end
	return tmp
end
function tmp_2 = code(x)
	t_0 = 0.70711 * ((6.039053782637804 / x) - x);
	tmp = 0.0;
	if (x <= -1.05)
		tmp = t_0;
	elseif (x <= 1.55)
		tmp = 1.6316775383 + (x * (-2.134856267379707 + (x * 1.3436228731669864)));
	else
		tmp = t_0;
	end
	tmp_2 = tmp;
end
code[x_] := Block[{t$95$0 = N[(0.70711 * N[(N[(6.039053782637804 / x), $MachinePrecision] - x), $MachinePrecision]), $MachinePrecision]}, If[LessEqual[x, -1.05], t$95$0, If[LessEqual[x, 1.55], N[(1.6316775383 + N[(x * N[(-2.134856267379707 + N[(x * 1.3436228731669864), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], t$95$0]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := 0.70711 \cdot \left(\frac{6.039053782637804}{x} - x\right)\\
\mathbf{if}\;x \leq -1.05:\\
\;\;\;\;t\_0\\

\mathbf{elif}\;x \leq 1.55:\\
\;\;\;\;1.6316775383 + x \cdot \left(-2.134856267379707 + x \cdot 1.3436228731669864\right)\\

\mathbf{else}:\\
\;\;\;\;t\_0\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if x < -1.05000000000000004 or 1.55000000000000004 < 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. Add Preprocessing
    3. Taylor expanded in x around inf

      \[\leadsto \mathsf{*.f64}\left(\frac{70711}{100000}, \mathsf{\_.f64}\left(\color{blue}{\left(\frac{\frac{27061}{4481}}{x}\right)}, x\right)\right) \]
    4. Step-by-step derivation
      1. /-lowering-/.f6499.5%

        \[\leadsto \mathsf{*.f64}\left(\frac{70711}{100000}, \mathsf{\_.f64}\left(\mathsf{/.f64}\left(\frac{27061}{4481}, x\right), x\right)\right) \]
    5. Simplified99.5%

      \[\leadsto 0.70711 \cdot \left(\color{blue}{\frac{6.039053782637804}{x}} - x\right) \]

    if -1.05000000000000004 < x < 1.55000000000000004

    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. Add Preprocessing
    3. Taylor expanded in x around 0

      \[\leadsto \color{blue}{\frac{16316775383}{10000000000} + x \cdot \left(\frac{134362287316698645903}{100000000000000000000} \cdot x - \frac{2134856267379707}{1000000000000000}\right)} \]
    4. Step-by-step derivation
      1. +-lowering-+.f64N/A

        \[\leadsto \mathsf{+.f64}\left(\frac{16316775383}{10000000000}, \color{blue}{\left(x \cdot \left(\frac{134362287316698645903}{100000000000000000000} \cdot x - \frac{2134856267379707}{1000000000000000}\right)\right)}\right) \]
      2. *-lowering-*.f64N/A

        \[\leadsto \mathsf{+.f64}\left(\frac{16316775383}{10000000000}, \mathsf{*.f64}\left(x, \color{blue}{\left(\frac{134362287316698645903}{100000000000000000000} \cdot x - \frac{2134856267379707}{1000000000000000}\right)}\right)\right) \]
      3. sub-negN/A

        \[\leadsto \mathsf{+.f64}\left(\frac{16316775383}{10000000000}, \mathsf{*.f64}\left(x, \left(\frac{134362287316698645903}{100000000000000000000} \cdot x + \color{blue}{\left(\mathsf{neg}\left(\frac{2134856267379707}{1000000000000000}\right)\right)}\right)\right)\right) \]
      4. metadata-evalN/A

        \[\leadsto \mathsf{+.f64}\left(\frac{16316775383}{10000000000}, \mathsf{*.f64}\left(x, \left(\frac{134362287316698645903}{100000000000000000000} \cdot x + \frac{-2134856267379707}{1000000000000000}\right)\right)\right) \]
      5. +-commutativeN/A

        \[\leadsto \mathsf{+.f64}\left(\frac{16316775383}{10000000000}, \mathsf{*.f64}\left(x, \left(\frac{-2134856267379707}{1000000000000000} + \color{blue}{\frac{134362287316698645903}{100000000000000000000} \cdot x}\right)\right)\right) \]
      6. +-lowering-+.f64N/A

        \[\leadsto \mathsf{+.f64}\left(\frac{16316775383}{10000000000}, \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(\frac{-2134856267379707}{1000000000000000}, \color{blue}{\left(\frac{134362287316698645903}{100000000000000000000} \cdot x\right)}\right)\right)\right) \]
      7. *-commutativeN/A

        \[\leadsto \mathsf{+.f64}\left(\frac{16316775383}{10000000000}, \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(\frac{-2134856267379707}{1000000000000000}, \left(x \cdot \color{blue}{\frac{134362287316698645903}{100000000000000000000}}\right)\right)\right)\right) \]
      8. *-lowering-*.f6499.3%

        \[\leadsto \mathsf{+.f64}\left(\frac{16316775383}{10000000000}, \mathsf{*.f64}\left(x, \mathsf{+.f64}\left(\frac{-2134856267379707}{1000000000000000}, \mathsf{*.f64}\left(x, \color{blue}{\frac{134362287316698645903}{100000000000000000000}}\right)\right)\right)\right) \]
    5. Simplified99.3%

      \[\leadsto \color{blue}{1.6316775383 + x \cdot \left(-2.134856267379707 + x \cdot 1.3436228731669864\right)} \]
  3. Recombined 2 regimes into one program.
  4. Add Preprocessing

Alternative 6: 99.8% 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 99.8%

    \[0.70711 \cdot \left(\frac{2.30753 + x \cdot 0.27061}{1 + x \cdot \left(0.99229 + x \cdot 0.04481\right)} - x\right) \]
  2. Add Preprocessing
  3. Add Preprocessing

Alternative 7: 99.0% accurate, 1.1× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := 0.70711 \cdot \left(\frac{6.039053782637804}{x} - x\right)\\ \mathbf{if}\;x \leq -1.05:\\ \;\;\;\;t\_0\\ \mathbf{elif}\;x \leq 2.8:\\ \;\;\;\;1.6316775383 + x \cdot -2.134856267379707\\ \mathbf{else}:\\ \;\;\;\;t\_0\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (let* ((t_0 (* 0.70711 (- (/ 6.039053782637804 x) x))))
   (if (<= x -1.05)
     t_0
     (if (<= x 2.8) (+ 1.6316775383 (* x -2.134856267379707)) t_0))))
double code(double x) {
	double t_0 = 0.70711 * ((6.039053782637804 / x) - x);
	double tmp;
	if (x <= -1.05) {
		tmp = t_0;
	} else if (x <= 2.8) {
		tmp = 1.6316775383 + (x * -2.134856267379707);
	} else {
		tmp = t_0;
	}
	return tmp;
}
real(8) function code(x)
    real(8), intent (in) :: x
    real(8) :: t_0
    real(8) :: tmp
    t_0 = 0.70711d0 * ((6.039053782637804d0 / x) - x)
    if (x <= (-1.05d0)) then
        tmp = t_0
    else if (x <= 2.8d0) then
        tmp = 1.6316775383d0 + (x * (-2.134856267379707d0))
    else
        tmp = t_0
    end if
    code = tmp
end function
public static double code(double x) {
	double t_0 = 0.70711 * ((6.039053782637804 / x) - x);
	double tmp;
	if (x <= -1.05) {
		tmp = t_0;
	} else if (x <= 2.8) {
		tmp = 1.6316775383 + (x * -2.134856267379707);
	} else {
		tmp = t_0;
	}
	return tmp;
}
def code(x):
	t_0 = 0.70711 * ((6.039053782637804 / x) - x)
	tmp = 0
	if x <= -1.05:
		tmp = t_0
	elif x <= 2.8:
		tmp = 1.6316775383 + (x * -2.134856267379707)
	else:
		tmp = t_0
	return tmp
function code(x)
	t_0 = Float64(0.70711 * Float64(Float64(6.039053782637804 / x) - x))
	tmp = 0.0
	if (x <= -1.05)
		tmp = t_0;
	elseif (x <= 2.8)
		tmp = Float64(1.6316775383 + Float64(x * -2.134856267379707));
	else
		tmp = t_0;
	end
	return tmp
end
function tmp_2 = code(x)
	t_0 = 0.70711 * ((6.039053782637804 / x) - x);
	tmp = 0.0;
	if (x <= -1.05)
		tmp = t_0;
	elseif (x <= 2.8)
		tmp = 1.6316775383 + (x * -2.134856267379707);
	else
		tmp = t_0;
	end
	tmp_2 = tmp;
end
code[x_] := Block[{t$95$0 = N[(0.70711 * N[(N[(6.039053782637804 / x), $MachinePrecision] - x), $MachinePrecision]), $MachinePrecision]}, If[LessEqual[x, -1.05], t$95$0, If[LessEqual[x, 2.8], N[(1.6316775383 + N[(x * -2.134856267379707), $MachinePrecision]), $MachinePrecision], t$95$0]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := 0.70711 \cdot \left(\frac{6.039053782637804}{x} - x\right)\\
\mathbf{if}\;x \leq -1.05:\\
\;\;\;\;t\_0\\

\mathbf{elif}\;x \leq 2.8:\\
\;\;\;\;1.6316775383 + x \cdot -2.134856267379707\\

\mathbf{else}:\\
\;\;\;\;t\_0\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if x < -1.05000000000000004 or 2.7999999999999998 < 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. Add Preprocessing
    3. Taylor expanded in x around inf

      \[\leadsto \mathsf{*.f64}\left(\frac{70711}{100000}, \mathsf{\_.f64}\left(\color{blue}{\left(\frac{\frac{27061}{4481}}{x}\right)}, x\right)\right) \]
    4. Step-by-step derivation
      1. /-lowering-/.f6499.5%

        \[\leadsto \mathsf{*.f64}\left(\frac{70711}{100000}, \mathsf{\_.f64}\left(\mathsf{/.f64}\left(\frac{27061}{4481}, x\right), x\right)\right) \]
    5. Simplified99.5%

      \[\leadsto 0.70711 \cdot \left(\color{blue}{\frac{6.039053782637804}{x}} - x\right) \]

    if -1.05000000000000004 < x < 2.7999999999999998

    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. Add Preprocessing
    3. Taylor expanded in x around 0

      \[\leadsto \color{blue}{\frac{16316775383}{10000000000} + \frac{-2134856267379707}{1000000000000000} \cdot x} \]
    4. Step-by-step derivation
      1. +-lowering-+.f64N/A

        \[\leadsto \mathsf{+.f64}\left(\frac{16316775383}{10000000000}, \color{blue}{\left(\frac{-2134856267379707}{1000000000000000} \cdot x\right)}\right) \]
      2. *-lowering-*.f6499.0%

        \[\leadsto \mathsf{+.f64}\left(\frac{16316775383}{10000000000}, \mathsf{*.f64}\left(\frac{-2134856267379707}{1000000000000000}, \color{blue}{x}\right)\right) \]
    5. Simplified99.0%

      \[\leadsto \color{blue}{1.6316775383 + -2.134856267379707 \cdot x} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification99.2%

    \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq -1.05:\\ \;\;\;\;0.70711 \cdot \left(\frac{6.039053782637804}{x} - x\right)\\ \mathbf{elif}\;x \leq 2.8:\\ \;\;\;\;1.6316775383 + x \cdot -2.134856267379707\\ \mathbf{else}:\\ \;\;\;\;0.70711 \cdot \left(\frac{6.039053782637804}{x} - x\right)\\ \end{array} \]
  5. Add Preprocessing

Alternative 8: 98.9% accurate, 1.3× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq -1.05:\\ \;\;\;\;x \cdot -0.70711\\ \mathbf{elif}\;x \leq 1.15:\\ \;\;\;\;1.6316775383 + x \cdot -2.134856267379707\\ \mathbf{else}:\\ \;\;\;\;x \cdot -0.70711\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (if (<= x -1.05)
   (* x -0.70711)
   (if (<= x 1.15) (+ 1.6316775383 (* x -2.134856267379707)) (* 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 + (x * -2.134856267379707);
	} 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 + (x * (-2.134856267379707d0))
    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 + (x * -2.134856267379707);
	} 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 + (x * -2.134856267379707)
	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 = Float64(1.6316775383 + Float64(x * -2.134856267379707));
	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 + (x * -2.134856267379707);
	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], N[(1.6316775383 + N[(x * -2.134856267379707), $MachinePrecision]), $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 1.15:\\
\;\;\;\;1.6316775383 + x \cdot -2.134856267379707\\

\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 99.7%

      \[0.70711 \cdot \left(\frac{2.30753 + x \cdot 0.27061}{1 + x \cdot \left(0.99229 + x \cdot 0.04481\right)} - x\right) \]
    2. Add Preprocessing
    3. Taylor expanded in x around inf

      \[\leadsto \color{blue}{\frac{-70711}{100000} \cdot x} \]
    4. Step-by-step derivation
      1. *-commutativeN/A

        \[\leadsto x \cdot \color{blue}{\frac{-70711}{100000}} \]
      2. *-lowering-*.f6499.2%

        \[\leadsto \mathsf{*.f64}\left(x, \color{blue}{\frac{-70711}{100000}}\right) \]
    5. Simplified99.2%

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

    if -1.05000000000000004 < x < 1.1499999999999999

    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. Add Preprocessing
    3. Taylor expanded in x around 0

      \[\leadsto \color{blue}{\frac{16316775383}{10000000000} + \frac{-2134856267379707}{1000000000000000} \cdot x} \]
    4. Step-by-step derivation
      1. +-lowering-+.f64N/A

        \[\leadsto \mathsf{+.f64}\left(\frac{16316775383}{10000000000}, \color{blue}{\left(\frac{-2134856267379707}{1000000000000000} \cdot x\right)}\right) \]
      2. *-lowering-*.f6499.0%

        \[\leadsto \mathsf{+.f64}\left(\frac{16316775383}{10000000000}, \mathsf{*.f64}\left(\frac{-2134856267379707}{1000000000000000}, \color{blue}{x}\right)\right) \]
    5. Simplified99.0%

      \[\leadsto \color{blue}{1.6316775383 + -2.134856267379707 \cdot x} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification99.1%

    \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq -1.05:\\ \;\;\;\;x \cdot -0.70711\\ \mathbf{elif}\;x \leq 1.15:\\ \;\;\;\;1.6316775383 + x \cdot -2.134856267379707\\ \mathbf{else}:\\ \;\;\;\;x \cdot -0.70711\\ \end{array} \]
  5. Add Preprocessing

Alternative 9: 98.3% accurate, 1.5× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq -3.5:\\ \;\;\;\;x \cdot -0.70711\\ \mathbf{elif}\;x \leq 1.15:\\ \;\;\;\;1.6316775383\\ \mathbf{else}:\\ \;\;\;\;x \cdot -0.70711\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (if (<= x -3.5) (* x -0.70711) (if (<= x 1.15) 1.6316775383 (* x -0.70711))))
double code(double x) {
	double tmp;
	if (x <= -3.5) {
		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 <= (-3.5d0)) 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 <= -3.5) {
		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 <= -3.5:
		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 <= -3.5)
		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 <= -3.5)
		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, -3.5], 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 -3.5:\\
\;\;\;\;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 < -3.5 or 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. Add Preprocessing
    3. Taylor expanded in x around inf

      \[\leadsto \color{blue}{\frac{-70711}{100000} \cdot x} \]
    4. Step-by-step derivation
      1. *-commutativeN/A

        \[\leadsto x \cdot \color{blue}{\frac{-70711}{100000}} \]
      2. *-lowering-*.f6499.2%

        \[\leadsto \mathsf{*.f64}\left(x, \color{blue}{\frac{-70711}{100000}}\right) \]
    5. Simplified99.2%

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

    if -3.5 < x < 1.1499999999999999

    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. Add Preprocessing
    3. Taylor expanded in x around 0

      \[\leadsto \color{blue}{\frac{16316775383}{10000000000}} \]
    4. Step-by-step derivation
      1. Simplified98.0%

        \[\leadsto \color{blue}{1.6316775383} \]
    5. Recombined 2 regimes into one program.
    6. Add Preprocessing

    Alternative 10: 50.1% 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 99.8%

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

      \[\leadsto \color{blue}{\frac{16316775383}{10000000000}} \]
    4. Step-by-step derivation
      1. Simplified51.6%

        \[\leadsto \color{blue}{1.6316775383} \]
      2. Add Preprocessing

      Reproduce

      ?
      herbie shell --seed 2024161 
      (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)))