Data.Approximate.Numerics:blog from approximate-0.2.2.1

Percentage Accurate: 99.7% → 99.9%
Time: 9.4s
Alternatives: 9
Speedup: 1.0×

Specification

?
\[\begin{array}{l} \\ \frac{6 \cdot \left(x - 1\right)}{\left(x + 1\right) + 4 \cdot \sqrt{x}} \end{array} \]
(FPCore (x)
 :precision binary64
 (/ (* 6.0 (- x 1.0)) (+ (+ x 1.0) (* 4.0 (sqrt x)))))
double code(double x) {
	return (6.0 * (x - 1.0)) / ((x + 1.0) + (4.0 * sqrt(x)));
}
real(8) function code(x)
    real(8), intent (in) :: x
    code = (6.0d0 * (x - 1.0d0)) / ((x + 1.0d0) + (4.0d0 * sqrt(x)))
end function
public static double code(double x) {
	return (6.0 * (x - 1.0)) / ((x + 1.0) + (4.0 * Math.sqrt(x)));
}
def code(x):
	return (6.0 * (x - 1.0)) / ((x + 1.0) + (4.0 * math.sqrt(x)))
function code(x)
	return Float64(Float64(6.0 * Float64(x - 1.0)) / Float64(Float64(x + 1.0) + Float64(4.0 * sqrt(x))))
end
function tmp = code(x)
	tmp = (6.0 * (x - 1.0)) / ((x + 1.0) + (4.0 * sqrt(x)));
end
code[x_] := N[(N[(6.0 * N[(x - 1.0), $MachinePrecision]), $MachinePrecision] / N[(N[(x + 1.0), $MachinePrecision] + N[(4.0 * N[Sqrt[x], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{6 \cdot \left(x - 1\right)}{\left(x + 1\right) + 4 \cdot \sqrt{x}}
\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 9 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: 99.7% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \frac{6 \cdot \left(x - 1\right)}{\left(x + 1\right) + 4 \cdot \sqrt{x}} \end{array} \]
(FPCore (x)
 :precision binary64
 (/ (* 6.0 (- x 1.0)) (+ (+ x 1.0) (* 4.0 (sqrt x)))))
double code(double x) {
	return (6.0 * (x - 1.0)) / ((x + 1.0) + (4.0 * sqrt(x)));
}
real(8) function code(x)
    real(8), intent (in) :: x
    code = (6.0d0 * (x - 1.0d0)) / ((x + 1.0d0) + (4.0d0 * sqrt(x)))
end function
public static double code(double x) {
	return (6.0 * (x - 1.0)) / ((x + 1.0) + (4.0 * Math.sqrt(x)));
}
def code(x):
	return (6.0 * (x - 1.0)) / ((x + 1.0) + (4.0 * math.sqrt(x)))
function code(x)
	return Float64(Float64(6.0 * Float64(x - 1.0)) / Float64(Float64(x + 1.0) + Float64(4.0 * sqrt(x))))
end
function tmp = code(x)
	tmp = (6.0 * (x - 1.0)) / ((x + 1.0) + (4.0 * sqrt(x)));
end
code[x_] := N[(N[(6.0 * N[(x - 1.0), $MachinePrecision]), $MachinePrecision] / N[(N[(x + 1.0), $MachinePrecision] + N[(4.0 * N[Sqrt[x], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{6 \cdot \left(x - 1\right)}{\left(x + 1\right) + 4 \cdot \sqrt{x}}
\end{array}

Alternative 1: 99.9% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \left(x + -1\right) \cdot \frac{6}{1 + \left(x + 4 \cdot \sqrt{x}\right)} \end{array} \]
(FPCore (x)
 :precision binary64
 (* (+ x -1.0) (/ 6.0 (+ 1.0 (+ x (* 4.0 (sqrt x)))))))
double code(double x) {
	return (x + -1.0) * (6.0 / (1.0 + (x + (4.0 * sqrt(x)))));
}
real(8) function code(x)
    real(8), intent (in) :: x
    code = (x + (-1.0d0)) * (6.0d0 / (1.0d0 + (x + (4.0d0 * sqrt(x)))))
end function
public static double code(double x) {
	return (x + -1.0) * (6.0 / (1.0 + (x + (4.0 * Math.sqrt(x)))));
}
def code(x):
	return (x + -1.0) * (6.0 / (1.0 + (x + (4.0 * math.sqrt(x)))))
function code(x)
	return Float64(Float64(x + -1.0) * Float64(6.0 / Float64(1.0 + Float64(x + Float64(4.0 * sqrt(x))))))
end
function tmp = code(x)
	tmp = (x + -1.0) * (6.0 / (1.0 + (x + (4.0 * sqrt(x)))));
end
code[x_] := N[(N[(x + -1.0), $MachinePrecision] * N[(6.0 / N[(1.0 + N[(x + N[(4.0 * N[Sqrt[x], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\left(x + -1\right) \cdot \frac{6}{1 + \left(x + 4 \cdot \sqrt{x}\right)}
\end{array}
Derivation
  1. Initial program 99.5%

    \[\frac{6 \cdot \left(x - 1\right)}{\left(x + 1\right) + 4 \cdot \sqrt{x}} \]
  2. Step-by-step derivation
    1. /-rgt-identity99.5%

      \[\leadsto \color{blue}{\frac{\frac{6 \cdot \left(x - 1\right)}{\left(x + 1\right) + 4 \cdot \sqrt{x}}}{1}} \]
    2. associate-/l/99.5%

      \[\leadsto \color{blue}{\frac{6 \cdot \left(x - 1\right)}{1 \cdot \left(\left(x + 1\right) + 4 \cdot \sqrt{x}\right)}} \]
    3. sub-neg99.5%

      \[\leadsto \frac{6 \cdot \color{blue}{\left(x + \left(-1\right)\right)}}{1 \cdot \left(\left(x + 1\right) + 4 \cdot \sqrt{x}\right)} \]
    4. distribute-lft-in99.5%

      \[\leadsto \frac{\color{blue}{6 \cdot x + 6 \cdot \left(-1\right)}}{1 \cdot \left(\left(x + 1\right) + 4 \cdot \sqrt{x}\right)} \]
    5. metadata-eval99.5%

      \[\leadsto \frac{6 \cdot x + 6 \cdot \color{blue}{-1}}{1 \cdot \left(\left(x + 1\right) + 4 \cdot \sqrt{x}\right)} \]
    6. metadata-eval99.5%

      \[\leadsto \frac{6 \cdot x + \color{blue}{-6}}{1 \cdot \left(\left(x + 1\right) + 4 \cdot \sqrt{x}\right)} \]
    7. metadata-eval99.5%

      \[\leadsto \frac{6 \cdot x + \color{blue}{\left(-6\right)}}{1 \cdot \left(\left(x + 1\right) + 4 \cdot \sqrt{x}\right)} \]
    8. fma-define99.5%

      \[\leadsto \frac{\color{blue}{\mathsf{fma}\left(6, x, -6\right)}}{1 \cdot \left(\left(x + 1\right) + 4 \cdot \sqrt{x}\right)} \]
    9. metadata-eval99.5%

      \[\leadsto \frac{\mathsf{fma}\left(6, x, \color{blue}{-6}\right)}{1 \cdot \left(\left(x + 1\right) + 4 \cdot \sqrt{x}\right)} \]
    10. *-lft-identity99.5%

      \[\leadsto \frac{\mathsf{fma}\left(6, x, -6\right)}{\color{blue}{\left(x + 1\right) + 4 \cdot \sqrt{x}}} \]
    11. +-commutative99.5%

      \[\leadsto \frac{\mathsf{fma}\left(6, x, -6\right)}{\color{blue}{\left(1 + x\right)} + 4 \cdot \sqrt{x}} \]
    12. associate-+l+99.5%

      \[\leadsto \frac{\mathsf{fma}\left(6, x, -6\right)}{\color{blue}{1 + \left(x + 4 \cdot \sqrt{x}\right)}} \]
    13. +-commutative99.5%

      \[\leadsto \frac{\mathsf{fma}\left(6, x, -6\right)}{1 + \color{blue}{\left(4 \cdot \sqrt{x} + x\right)}} \]
    14. fma-define99.5%

      \[\leadsto \frac{\mathsf{fma}\left(6, x, -6\right)}{1 + \color{blue}{\mathsf{fma}\left(4, \sqrt{x}, x\right)}} \]
  3. Simplified99.5%

    \[\leadsto \color{blue}{\frac{\mathsf{fma}\left(6, x, -6\right)}{1 + \mathsf{fma}\left(4, \sqrt{x}, x\right)}} \]
  4. Add Preprocessing
  5. Step-by-step derivation
    1. fma-undefine99.5%

      \[\leadsto \frac{\color{blue}{6 \cdot x + -6}}{1 + \mathsf{fma}\left(4, \sqrt{x}, x\right)} \]
    2. metadata-eval99.5%

      \[\leadsto \frac{6 \cdot x + \color{blue}{6 \cdot -1}}{1 + \mathsf{fma}\left(4, \sqrt{x}, x\right)} \]
    3. metadata-eval99.5%

      \[\leadsto \frac{6 \cdot x + 6 \cdot \color{blue}{\left(-1\right)}}{1 + \mathsf{fma}\left(4, \sqrt{x}, x\right)} \]
    4. distribute-lft-in99.5%

      \[\leadsto \frac{\color{blue}{6 \cdot \left(x + \left(-1\right)\right)}}{1 + \mathsf{fma}\left(4, \sqrt{x}, x\right)} \]
    5. sub-neg99.5%

      \[\leadsto \frac{6 \cdot \color{blue}{\left(x - 1\right)}}{1 + \mathsf{fma}\left(4, \sqrt{x}, x\right)} \]
    6. +-commutative99.5%

      \[\leadsto \frac{6 \cdot \left(x - 1\right)}{\color{blue}{\mathsf{fma}\left(4, \sqrt{x}, x\right) + 1}} \]
    7. fma-undefine99.5%

      \[\leadsto \frac{6 \cdot \left(x - 1\right)}{\color{blue}{\left(4 \cdot \sqrt{x} + x\right)} + 1} \]
    8. associate-+r+99.5%

      \[\leadsto \frac{6 \cdot \left(x - 1\right)}{\color{blue}{4 \cdot \sqrt{x} + \left(x + 1\right)}} \]
    9. +-commutative99.5%

      \[\leadsto \frac{6 \cdot \left(x - 1\right)}{\color{blue}{\left(x + 1\right) + 4 \cdot \sqrt{x}}} \]
    10. *-commutative99.5%

      \[\leadsto \frac{\color{blue}{\left(x - 1\right) \cdot 6}}{\left(x + 1\right) + 4 \cdot \sqrt{x}} \]
    11. associate-/l*99.9%

      \[\leadsto \color{blue}{\left(x - 1\right) \cdot \frac{6}{\left(x + 1\right) + 4 \cdot \sqrt{x}}} \]
    12. sub-neg99.9%

      \[\leadsto \color{blue}{\left(x + \left(-1\right)\right)} \cdot \frac{6}{\left(x + 1\right) + 4 \cdot \sqrt{x}} \]
    13. metadata-eval99.9%

      \[\leadsto \left(x + \color{blue}{-1}\right) \cdot \frac{6}{\left(x + 1\right) + 4 \cdot \sqrt{x}} \]
    14. +-commutative99.9%

      \[\leadsto \left(x + -1\right) \cdot \frac{6}{\color{blue}{4 \cdot \sqrt{x} + \left(x + 1\right)}} \]
    15. fma-define99.9%

      \[\leadsto \left(x + -1\right) \cdot \frac{6}{\color{blue}{\mathsf{fma}\left(4, \sqrt{x}, x + 1\right)}} \]
  6. Applied egg-rr99.9%

    \[\leadsto \color{blue}{\left(x + -1\right) \cdot \frac{6}{\mathsf{fma}\left(4, \sqrt{x}, x + 1\right)}} \]
  7. Taylor expanded in x around 0 99.9%

    \[\leadsto \left(x + -1\right) \cdot \frac{6}{\color{blue}{1 + \left(x + 4 \cdot \sqrt{x}\right)}} \]
  8. Add Preprocessing

Alternative 2: 97.9% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq 4:\\ \;\;\;\;\frac{\left(x + -1\right) \cdot 6}{1 + 4 \cdot \sqrt{x}}\\ \mathbf{else}:\\ \;\;\;\;\frac{6}{1 - \frac{-4}{\sqrt{x}}}\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (if (<= x 4.0)
   (/ (* (+ x -1.0) 6.0) (+ 1.0 (* 4.0 (sqrt x))))
   (/ 6.0 (- 1.0 (/ -4.0 (sqrt x))))))
double code(double x) {
	double tmp;
	if (x <= 4.0) {
		tmp = ((x + -1.0) * 6.0) / (1.0 + (4.0 * sqrt(x)));
	} else {
		tmp = 6.0 / (1.0 - (-4.0 / sqrt(x)));
	}
	return tmp;
}
real(8) function code(x)
    real(8), intent (in) :: x
    real(8) :: tmp
    if (x <= 4.0d0) then
        tmp = ((x + (-1.0d0)) * 6.0d0) / (1.0d0 + (4.0d0 * sqrt(x)))
    else
        tmp = 6.0d0 / (1.0d0 - ((-4.0d0) / sqrt(x)))
    end if
    code = tmp
end function
public static double code(double x) {
	double tmp;
	if (x <= 4.0) {
		tmp = ((x + -1.0) * 6.0) / (1.0 + (4.0 * Math.sqrt(x)));
	} else {
		tmp = 6.0 / (1.0 - (-4.0 / Math.sqrt(x)));
	}
	return tmp;
}
def code(x):
	tmp = 0
	if x <= 4.0:
		tmp = ((x + -1.0) * 6.0) / (1.0 + (4.0 * math.sqrt(x)))
	else:
		tmp = 6.0 / (1.0 - (-4.0 / math.sqrt(x)))
	return tmp
function code(x)
	tmp = 0.0
	if (x <= 4.0)
		tmp = Float64(Float64(Float64(x + -1.0) * 6.0) / Float64(1.0 + Float64(4.0 * sqrt(x))));
	else
		tmp = Float64(6.0 / Float64(1.0 - Float64(-4.0 / sqrt(x))));
	end
	return tmp
end
function tmp_2 = code(x)
	tmp = 0.0;
	if (x <= 4.0)
		tmp = ((x + -1.0) * 6.0) / (1.0 + (4.0 * sqrt(x)));
	else
		tmp = 6.0 / (1.0 - (-4.0 / sqrt(x)));
	end
	tmp_2 = tmp;
end
code[x_] := If[LessEqual[x, 4.0], N[(N[(N[(x + -1.0), $MachinePrecision] * 6.0), $MachinePrecision] / N[(1.0 + N[(4.0 * N[Sqrt[x], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(6.0 / N[(1.0 - N[(-4.0 / N[Sqrt[x], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;x \leq 4:\\
\;\;\;\;\frac{\left(x + -1\right) \cdot 6}{1 + 4 \cdot \sqrt{x}}\\

\mathbf{else}:\\
\;\;\;\;\frac{6}{1 - \frac{-4}{\sqrt{x}}}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if x < 4

    1. Initial program 99.9%

      \[\frac{6 \cdot \left(x - 1\right)}{\left(x + 1\right) + 4 \cdot \sqrt{x}} \]
    2. Add Preprocessing
    3. Taylor expanded in x around 0 97.9%

      \[\leadsto \frac{6 \cdot \left(x - 1\right)}{\color{blue}{1} + 4 \cdot \sqrt{x}} \]

    if 4 < x

    1. Initial program 99.1%

      \[\frac{6 \cdot \left(x - 1\right)}{\left(x + 1\right) + 4 \cdot \sqrt{x}} \]
    2. Step-by-step derivation
      1. /-rgt-identity99.1%

        \[\leadsto \color{blue}{\frac{\frac{6 \cdot \left(x - 1\right)}{\left(x + 1\right) + 4 \cdot \sqrt{x}}}{1}} \]
      2. associate-/l/99.1%

        \[\leadsto \color{blue}{\frac{6 \cdot \left(x - 1\right)}{1 \cdot \left(\left(x + 1\right) + 4 \cdot \sqrt{x}\right)}} \]
      3. sub-neg99.1%

        \[\leadsto \frac{6 \cdot \color{blue}{\left(x + \left(-1\right)\right)}}{1 \cdot \left(\left(x + 1\right) + 4 \cdot \sqrt{x}\right)} \]
      4. distribute-lft-in99.1%

        \[\leadsto \frac{\color{blue}{6 \cdot x + 6 \cdot \left(-1\right)}}{1 \cdot \left(\left(x + 1\right) + 4 \cdot \sqrt{x}\right)} \]
      5. metadata-eval99.1%

        \[\leadsto \frac{6 \cdot x + 6 \cdot \color{blue}{-1}}{1 \cdot \left(\left(x + 1\right) + 4 \cdot \sqrt{x}\right)} \]
      6. metadata-eval99.1%

        \[\leadsto \frac{6 \cdot x + \color{blue}{-6}}{1 \cdot \left(\left(x + 1\right) + 4 \cdot \sqrt{x}\right)} \]
      7. metadata-eval99.1%

        \[\leadsto \frac{6 \cdot x + \color{blue}{\left(-6\right)}}{1 \cdot \left(\left(x + 1\right) + 4 \cdot \sqrt{x}\right)} \]
      8. fma-define99.1%

        \[\leadsto \frac{\color{blue}{\mathsf{fma}\left(6, x, -6\right)}}{1 \cdot \left(\left(x + 1\right) + 4 \cdot \sqrt{x}\right)} \]
      9. metadata-eval99.1%

        \[\leadsto \frac{\mathsf{fma}\left(6, x, \color{blue}{-6}\right)}{1 \cdot \left(\left(x + 1\right) + 4 \cdot \sqrt{x}\right)} \]
      10. *-lft-identity99.1%

        \[\leadsto \frac{\mathsf{fma}\left(6, x, -6\right)}{\color{blue}{\left(x + 1\right) + 4 \cdot \sqrt{x}}} \]
      11. +-commutative99.1%

        \[\leadsto \frac{\mathsf{fma}\left(6, x, -6\right)}{\color{blue}{\left(1 + x\right)} + 4 \cdot \sqrt{x}} \]
      12. associate-+l+99.1%

        \[\leadsto \frac{\mathsf{fma}\left(6, x, -6\right)}{\color{blue}{1 + \left(x + 4 \cdot \sqrt{x}\right)}} \]
      13. +-commutative99.1%

        \[\leadsto \frac{\mathsf{fma}\left(6, x, -6\right)}{1 + \color{blue}{\left(4 \cdot \sqrt{x} + x\right)}} \]
      14. fma-define99.1%

        \[\leadsto \frac{\mathsf{fma}\left(6, x, -6\right)}{1 + \color{blue}{\mathsf{fma}\left(4, \sqrt{x}, x\right)}} \]
    3. Simplified99.1%

      \[\leadsto \color{blue}{\frac{\mathsf{fma}\left(6, x, -6\right)}{1 + \mathsf{fma}\left(4, \sqrt{x}, x\right)}} \]
    4. Add Preprocessing
    5. Taylor expanded in x around inf 97.9%

      \[\leadsto \color{blue}{\frac{6}{1 + 4 \cdot \sqrt{\frac{1}{x}}}} \]
    6. Step-by-step derivation
      1. add-exp-log97.9%

        \[\leadsto \color{blue}{e^{\log \left(\frac{6}{1 + 4 \cdot \sqrt{\frac{1}{x}}}\right)}} \]
      2. log-div97.9%

        \[\leadsto e^{\color{blue}{\log 6 - \log \left(1 + 4 \cdot \sqrt{\frac{1}{x}}\right)}} \]
      3. log1p-define97.9%

        \[\leadsto e^{\log 6 - \color{blue}{\mathsf{log1p}\left(4 \cdot \sqrt{\frac{1}{x}}\right)}} \]
      4. sqrt-div97.9%

        \[\leadsto e^{\log 6 - \mathsf{log1p}\left(4 \cdot \color{blue}{\frac{\sqrt{1}}{\sqrt{x}}}\right)} \]
      5. metadata-eval97.9%

        \[\leadsto e^{\log 6 - \mathsf{log1p}\left(4 \cdot \frac{\color{blue}{1}}{\sqrt{x}}\right)} \]
      6. un-div-inv97.9%

        \[\leadsto e^{\log 6 - \mathsf{log1p}\left(\color{blue}{\frac{4}{\sqrt{x}}}\right)} \]
    7. Applied egg-rr97.9%

      \[\leadsto \color{blue}{e^{\log 6 - \mathsf{log1p}\left(\frac{4}{\sqrt{x}}\right)}} \]
    8. Step-by-step derivation
      1. exp-diff97.9%

        \[\leadsto \color{blue}{\frac{e^{\log 6}}{e^{\mathsf{log1p}\left(\frac{4}{\sqrt{x}}\right)}}} \]
      2. rem-exp-log97.9%

        \[\leadsto \frac{\color{blue}{6}}{e^{\mathsf{log1p}\left(\frac{4}{\sqrt{x}}\right)}} \]
      3. log1p-undefine97.9%

        \[\leadsto \frac{6}{e^{\color{blue}{\log \left(1 + \frac{4}{\sqrt{x}}\right)}}} \]
      4. rem-exp-log97.9%

        \[\leadsto \frac{6}{\color{blue}{1 + \frac{4}{\sqrt{x}}}} \]
      5. remove-double-neg97.9%

        \[\leadsto \frac{6}{1 + \color{blue}{\left(-\left(-\frac{4}{\sqrt{x}}\right)\right)}} \]
      6. unsub-neg97.9%

        \[\leadsto \frac{6}{\color{blue}{1 - \left(-\frac{4}{\sqrt{x}}\right)}} \]
      7. distribute-neg-frac97.9%

        \[\leadsto \frac{6}{1 - \color{blue}{\frac{-4}{\sqrt{x}}}} \]
      8. metadata-eval97.9%

        \[\leadsto \frac{6}{1 - \frac{\color{blue}{-4}}{\sqrt{x}}} \]
    9. Simplified97.9%

      \[\leadsto \color{blue}{\frac{6}{1 - \frac{-4}{\sqrt{x}}}} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification97.9%

    \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq 4:\\ \;\;\;\;\frac{\left(x + -1\right) \cdot 6}{1 + 4 \cdot \sqrt{x}}\\ \mathbf{else}:\\ \;\;\;\;\frac{6}{1 - \frac{-4}{\sqrt{x}}}\\ \end{array} \]
  5. Add Preprocessing

Alternative 3: 97.9% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq 4:\\ \;\;\;\;\left(x + -1\right) \cdot \frac{6}{1 + 4 \cdot \sqrt{x}}\\ \mathbf{else}:\\ \;\;\;\;\frac{6}{1 - \frac{-4}{\sqrt{x}}}\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (if (<= x 4.0)
   (* (+ x -1.0) (/ 6.0 (+ 1.0 (* 4.0 (sqrt x)))))
   (/ 6.0 (- 1.0 (/ -4.0 (sqrt x))))))
double code(double x) {
	double tmp;
	if (x <= 4.0) {
		tmp = (x + -1.0) * (6.0 / (1.0 + (4.0 * sqrt(x))));
	} else {
		tmp = 6.0 / (1.0 - (-4.0 / sqrt(x)));
	}
	return tmp;
}
real(8) function code(x)
    real(8), intent (in) :: x
    real(8) :: tmp
    if (x <= 4.0d0) then
        tmp = (x + (-1.0d0)) * (6.0d0 / (1.0d0 + (4.0d0 * sqrt(x))))
    else
        tmp = 6.0d0 / (1.0d0 - ((-4.0d0) / sqrt(x)))
    end if
    code = tmp
end function
public static double code(double x) {
	double tmp;
	if (x <= 4.0) {
		tmp = (x + -1.0) * (6.0 / (1.0 + (4.0 * Math.sqrt(x))));
	} else {
		tmp = 6.0 / (1.0 - (-4.0 / Math.sqrt(x)));
	}
	return tmp;
}
def code(x):
	tmp = 0
	if x <= 4.0:
		tmp = (x + -1.0) * (6.0 / (1.0 + (4.0 * math.sqrt(x))))
	else:
		tmp = 6.0 / (1.0 - (-4.0 / math.sqrt(x)))
	return tmp
function code(x)
	tmp = 0.0
	if (x <= 4.0)
		tmp = Float64(Float64(x + -1.0) * Float64(6.0 / Float64(1.0 + Float64(4.0 * sqrt(x)))));
	else
		tmp = Float64(6.0 / Float64(1.0 - Float64(-4.0 / sqrt(x))));
	end
	return tmp
end
function tmp_2 = code(x)
	tmp = 0.0;
	if (x <= 4.0)
		tmp = (x + -1.0) * (6.0 / (1.0 + (4.0 * sqrt(x))));
	else
		tmp = 6.0 / (1.0 - (-4.0 / sqrt(x)));
	end
	tmp_2 = tmp;
end
code[x_] := If[LessEqual[x, 4.0], N[(N[(x + -1.0), $MachinePrecision] * N[(6.0 / N[(1.0 + N[(4.0 * N[Sqrt[x], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(6.0 / N[(1.0 - N[(-4.0 / N[Sqrt[x], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;x \leq 4:\\
\;\;\;\;\left(x + -1\right) \cdot \frac{6}{1 + 4 \cdot \sqrt{x}}\\

\mathbf{else}:\\
\;\;\;\;\frac{6}{1 - \frac{-4}{\sqrt{x}}}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if x < 4

    1. Initial program 99.9%

      \[\frac{6 \cdot \left(x - 1\right)}{\left(x + 1\right) + 4 \cdot \sqrt{x}} \]
    2. Step-by-step derivation
      1. /-rgt-identity99.9%

        \[\leadsto \color{blue}{\frac{\frac{6 \cdot \left(x - 1\right)}{\left(x + 1\right) + 4 \cdot \sqrt{x}}}{1}} \]
      2. associate-/l/99.9%

        \[\leadsto \color{blue}{\frac{6 \cdot \left(x - 1\right)}{1 \cdot \left(\left(x + 1\right) + 4 \cdot \sqrt{x}\right)}} \]
      3. sub-neg99.9%

        \[\leadsto \frac{6 \cdot \color{blue}{\left(x + \left(-1\right)\right)}}{1 \cdot \left(\left(x + 1\right) + 4 \cdot \sqrt{x}\right)} \]
      4. distribute-lft-in99.9%

        \[\leadsto \frac{\color{blue}{6 \cdot x + 6 \cdot \left(-1\right)}}{1 \cdot \left(\left(x + 1\right) + 4 \cdot \sqrt{x}\right)} \]
      5. metadata-eval99.9%

        \[\leadsto \frac{6 \cdot x + 6 \cdot \color{blue}{-1}}{1 \cdot \left(\left(x + 1\right) + 4 \cdot \sqrt{x}\right)} \]
      6. metadata-eval99.9%

        \[\leadsto \frac{6 \cdot x + \color{blue}{-6}}{1 \cdot \left(\left(x + 1\right) + 4 \cdot \sqrt{x}\right)} \]
      7. metadata-eval99.9%

        \[\leadsto \frac{6 \cdot x + \color{blue}{\left(-6\right)}}{1 \cdot \left(\left(x + 1\right) + 4 \cdot \sqrt{x}\right)} \]
      8. fma-define99.9%

        \[\leadsto \frac{\color{blue}{\mathsf{fma}\left(6, x, -6\right)}}{1 \cdot \left(\left(x + 1\right) + 4 \cdot \sqrt{x}\right)} \]
      9. metadata-eval99.9%

        \[\leadsto \frac{\mathsf{fma}\left(6, x, \color{blue}{-6}\right)}{1 \cdot \left(\left(x + 1\right) + 4 \cdot \sqrt{x}\right)} \]
      10. *-lft-identity99.9%

        \[\leadsto \frac{\mathsf{fma}\left(6, x, -6\right)}{\color{blue}{\left(x + 1\right) + 4 \cdot \sqrt{x}}} \]
      11. +-commutative99.9%

        \[\leadsto \frac{\mathsf{fma}\left(6, x, -6\right)}{\color{blue}{\left(1 + x\right)} + 4 \cdot \sqrt{x}} \]
      12. associate-+l+99.9%

        \[\leadsto \frac{\mathsf{fma}\left(6, x, -6\right)}{\color{blue}{1 + \left(x + 4 \cdot \sqrt{x}\right)}} \]
      13. +-commutative99.9%

        \[\leadsto \frac{\mathsf{fma}\left(6, x, -6\right)}{1 + \color{blue}{\left(4 \cdot \sqrt{x} + x\right)}} \]
      14. fma-define99.9%

        \[\leadsto \frac{\mathsf{fma}\left(6, x, -6\right)}{1 + \color{blue}{\mathsf{fma}\left(4, \sqrt{x}, x\right)}} \]
    3. Simplified99.9%

      \[\leadsto \color{blue}{\frac{\mathsf{fma}\left(6, x, -6\right)}{1 + \mathsf{fma}\left(4, \sqrt{x}, x\right)}} \]
    4. Add Preprocessing
    5. Step-by-step derivation
      1. fma-undefine99.9%

        \[\leadsto \frac{\color{blue}{6 \cdot x + -6}}{1 + \mathsf{fma}\left(4, \sqrt{x}, x\right)} \]
      2. metadata-eval99.9%

        \[\leadsto \frac{6 \cdot x + \color{blue}{6 \cdot -1}}{1 + \mathsf{fma}\left(4, \sqrt{x}, x\right)} \]
      3. metadata-eval99.9%

        \[\leadsto \frac{6 \cdot x + 6 \cdot \color{blue}{\left(-1\right)}}{1 + \mathsf{fma}\left(4, \sqrt{x}, x\right)} \]
      4. distribute-lft-in99.9%

        \[\leadsto \frac{\color{blue}{6 \cdot \left(x + \left(-1\right)\right)}}{1 + \mathsf{fma}\left(4, \sqrt{x}, x\right)} \]
      5. sub-neg99.9%

        \[\leadsto \frac{6 \cdot \color{blue}{\left(x - 1\right)}}{1 + \mathsf{fma}\left(4, \sqrt{x}, x\right)} \]
      6. +-commutative99.9%

        \[\leadsto \frac{6 \cdot \left(x - 1\right)}{\color{blue}{\mathsf{fma}\left(4, \sqrt{x}, x\right) + 1}} \]
      7. fma-undefine99.9%

        \[\leadsto \frac{6 \cdot \left(x - 1\right)}{\color{blue}{\left(4 \cdot \sqrt{x} + x\right)} + 1} \]
      8. associate-+r+99.9%

        \[\leadsto \frac{6 \cdot \left(x - 1\right)}{\color{blue}{4 \cdot \sqrt{x} + \left(x + 1\right)}} \]
      9. +-commutative99.9%

        \[\leadsto \frac{6 \cdot \left(x - 1\right)}{\color{blue}{\left(x + 1\right) + 4 \cdot \sqrt{x}}} \]
      10. *-commutative99.9%

        \[\leadsto \frac{\color{blue}{\left(x - 1\right) \cdot 6}}{\left(x + 1\right) + 4 \cdot \sqrt{x}} \]
      11. associate-/l*99.9%

        \[\leadsto \color{blue}{\left(x - 1\right) \cdot \frac{6}{\left(x + 1\right) + 4 \cdot \sqrt{x}}} \]
      12. sub-neg99.9%

        \[\leadsto \color{blue}{\left(x + \left(-1\right)\right)} \cdot \frac{6}{\left(x + 1\right) + 4 \cdot \sqrt{x}} \]
      13. metadata-eval99.9%

        \[\leadsto \left(x + \color{blue}{-1}\right) \cdot \frac{6}{\left(x + 1\right) + 4 \cdot \sqrt{x}} \]
      14. +-commutative99.9%

        \[\leadsto \left(x + -1\right) \cdot \frac{6}{\color{blue}{4 \cdot \sqrt{x} + \left(x + 1\right)}} \]
      15. fma-define99.9%

        \[\leadsto \left(x + -1\right) \cdot \frac{6}{\color{blue}{\mathsf{fma}\left(4, \sqrt{x}, x + 1\right)}} \]
    6. Applied egg-rr99.9%

      \[\leadsto \color{blue}{\left(x + -1\right) \cdot \frac{6}{\mathsf{fma}\left(4, \sqrt{x}, x + 1\right)}} \]
    7. Taylor expanded in x around 0 97.9%

      \[\leadsto \left(x + -1\right) \cdot \color{blue}{\frac{6}{1 + 4 \cdot \sqrt{x}}} \]

    if 4 < x

    1. Initial program 99.1%

      \[\frac{6 \cdot \left(x - 1\right)}{\left(x + 1\right) + 4 \cdot \sqrt{x}} \]
    2. Step-by-step derivation
      1. /-rgt-identity99.1%

        \[\leadsto \color{blue}{\frac{\frac{6 \cdot \left(x - 1\right)}{\left(x + 1\right) + 4 \cdot \sqrt{x}}}{1}} \]
      2. associate-/l/99.1%

        \[\leadsto \color{blue}{\frac{6 \cdot \left(x - 1\right)}{1 \cdot \left(\left(x + 1\right) + 4 \cdot \sqrt{x}\right)}} \]
      3. sub-neg99.1%

        \[\leadsto \frac{6 \cdot \color{blue}{\left(x + \left(-1\right)\right)}}{1 \cdot \left(\left(x + 1\right) + 4 \cdot \sqrt{x}\right)} \]
      4. distribute-lft-in99.1%

        \[\leadsto \frac{\color{blue}{6 \cdot x + 6 \cdot \left(-1\right)}}{1 \cdot \left(\left(x + 1\right) + 4 \cdot \sqrt{x}\right)} \]
      5. metadata-eval99.1%

        \[\leadsto \frac{6 \cdot x + 6 \cdot \color{blue}{-1}}{1 \cdot \left(\left(x + 1\right) + 4 \cdot \sqrt{x}\right)} \]
      6. metadata-eval99.1%

        \[\leadsto \frac{6 \cdot x + \color{blue}{-6}}{1 \cdot \left(\left(x + 1\right) + 4 \cdot \sqrt{x}\right)} \]
      7. metadata-eval99.1%

        \[\leadsto \frac{6 \cdot x + \color{blue}{\left(-6\right)}}{1 \cdot \left(\left(x + 1\right) + 4 \cdot \sqrt{x}\right)} \]
      8. fma-define99.1%

        \[\leadsto \frac{\color{blue}{\mathsf{fma}\left(6, x, -6\right)}}{1 \cdot \left(\left(x + 1\right) + 4 \cdot \sqrt{x}\right)} \]
      9. metadata-eval99.1%

        \[\leadsto \frac{\mathsf{fma}\left(6, x, \color{blue}{-6}\right)}{1 \cdot \left(\left(x + 1\right) + 4 \cdot \sqrt{x}\right)} \]
      10. *-lft-identity99.1%

        \[\leadsto \frac{\mathsf{fma}\left(6, x, -6\right)}{\color{blue}{\left(x + 1\right) + 4 \cdot \sqrt{x}}} \]
      11. +-commutative99.1%

        \[\leadsto \frac{\mathsf{fma}\left(6, x, -6\right)}{\color{blue}{\left(1 + x\right)} + 4 \cdot \sqrt{x}} \]
      12. associate-+l+99.1%

        \[\leadsto \frac{\mathsf{fma}\left(6, x, -6\right)}{\color{blue}{1 + \left(x + 4 \cdot \sqrt{x}\right)}} \]
      13. +-commutative99.1%

        \[\leadsto \frac{\mathsf{fma}\left(6, x, -6\right)}{1 + \color{blue}{\left(4 \cdot \sqrt{x} + x\right)}} \]
      14. fma-define99.1%

        \[\leadsto \frac{\mathsf{fma}\left(6, x, -6\right)}{1 + \color{blue}{\mathsf{fma}\left(4, \sqrt{x}, x\right)}} \]
    3. Simplified99.1%

      \[\leadsto \color{blue}{\frac{\mathsf{fma}\left(6, x, -6\right)}{1 + \mathsf{fma}\left(4, \sqrt{x}, x\right)}} \]
    4. Add Preprocessing
    5. Taylor expanded in x around inf 97.9%

      \[\leadsto \color{blue}{\frac{6}{1 + 4 \cdot \sqrt{\frac{1}{x}}}} \]
    6. Step-by-step derivation
      1. add-exp-log97.9%

        \[\leadsto \color{blue}{e^{\log \left(\frac{6}{1 + 4 \cdot \sqrt{\frac{1}{x}}}\right)}} \]
      2. log-div97.9%

        \[\leadsto e^{\color{blue}{\log 6 - \log \left(1 + 4 \cdot \sqrt{\frac{1}{x}}\right)}} \]
      3. log1p-define97.9%

        \[\leadsto e^{\log 6 - \color{blue}{\mathsf{log1p}\left(4 \cdot \sqrt{\frac{1}{x}}\right)}} \]
      4. sqrt-div97.9%

        \[\leadsto e^{\log 6 - \mathsf{log1p}\left(4 \cdot \color{blue}{\frac{\sqrt{1}}{\sqrt{x}}}\right)} \]
      5. metadata-eval97.9%

        \[\leadsto e^{\log 6 - \mathsf{log1p}\left(4 \cdot \frac{\color{blue}{1}}{\sqrt{x}}\right)} \]
      6. un-div-inv97.9%

        \[\leadsto e^{\log 6 - \mathsf{log1p}\left(\color{blue}{\frac{4}{\sqrt{x}}}\right)} \]
    7. Applied egg-rr97.9%

      \[\leadsto \color{blue}{e^{\log 6 - \mathsf{log1p}\left(\frac{4}{\sqrt{x}}\right)}} \]
    8. Step-by-step derivation
      1. exp-diff97.9%

        \[\leadsto \color{blue}{\frac{e^{\log 6}}{e^{\mathsf{log1p}\left(\frac{4}{\sqrt{x}}\right)}}} \]
      2. rem-exp-log97.9%

        \[\leadsto \frac{\color{blue}{6}}{e^{\mathsf{log1p}\left(\frac{4}{\sqrt{x}}\right)}} \]
      3. log1p-undefine97.9%

        \[\leadsto \frac{6}{e^{\color{blue}{\log \left(1 + \frac{4}{\sqrt{x}}\right)}}} \]
      4. rem-exp-log97.9%

        \[\leadsto \frac{6}{\color{blue}{1 + \frac{4}{\sqrt{x}}}} \]
      5. remove-double-neg97.9%

        \[\leadsto \frac{6}{1 + \color{blue}{\left(-\left(-\frac{4}{\sqrt{x}}\right)\right)}} \]
      6. unsub-neg97.9%

        \[\leadsto \frac{6}{\color{blue}{1 - \left(-\frac{4}{\sqrt{x}}\right)}} \]
      7. distribute-neg-frac97.9%

        \[\leadsto \frac{6}{1 - \color{blue}{\frac{-4}{\sqrt{x}}}} \]
      8. metadata-eval97.9%

        \[\leadsto \frac{6}{1 - \frac{\color{blue}{-4}}{\sqrt{x}}} \]
    9. Simplified97.9%

      \[\leadsto \color{blue}{\frac{6}{1 - \frac{-4}{\sqrt{x}}}} \]
  3. Recombined 2 regimes into one program.
  4. Add Preprocessing

Alternative 4: 97.8% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq 1:\\ \;\;\;\;\frac{-6}{4 \cdot \sqrt{x} + \left(x + 1\right)}\\ \mathbf{else}:\\ \;\;\;\;\frac{6}{1 - \frac{-4}{\sqrt{x}}}\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (if (<= x 1.0)
   (/ -6.0 (+ (* 4.0 (sqrt x)) (+ x 1.0)))
   (/ 6.0 (- 1.0 (/ -4.0 (sqrt x))))))
double code(double x) {
	double tmp;
	if (x <= 1.0) {
		tmp = -6.0 / ((4.0 * sqrt(x)) + (x + 1.0));
	} else {
		tmp = 6.0 / (1.0 - (-4.0 / sqrt(x)));
	}
	return tmp;
}
real(8) function code(x)
    real(8), intent (in) :: x
    real(8) :: tmp
    if (x <= 1.0d0) then
        tmp = (-6.0d0) / ((4.0d0 * sqrt(x)) + (x + 1.0d0))
    else
        tmp = 6.0d0 / (1.0d0 - ((-4.0d0) / sqrt(x)))
    end if
    code = tmp
end function
public static double code(double x) {
	double tmp;
	if (x <= 1.0) {
		tmp = -6.0 / ((4.0 * Math.sqrt(x)) + (x + 1.0));
	} else {
		tmp = 6.0 / (1.0 - (-4.0 / Math.sqrt(x)));
	}
	return tmp;
}
def code(x):
	tmp = 0
	if x <= 1.0:
		tmp = -6.0 / ((4.0 * math.sqrt(x)) + (x + 1.0))
	else:
		tmp = 6.0 / (1.0 - (-4.0 / math.sqrt(x)))
	return tmp
function code(x)
	tmp = 0.0
	if (x <= 1.0)
		tmp = Float64(-6.0 / Float64(Float64(4.0 * sqrt(x)) + Float64(x + 1.0)));
	else
		tmp = Float64(6.0 / Float64(1.0 - Float64(-4.0 / sqrt(x))));
	end
	return tmp
end
function tmp_2 = code(x)
	tmp = 0.0;
	if (x <= 1.0)
		tmp = -6.0 / ((4.0 * sqrt(x)) + (x + 1.0));
	else
		tmp = 6.0 / (1.0 - (-4.0 / sqrt(x)));
	end
	tmp_2 = tmp;
end
code[x_] := If[LessEqual[x, 1.0], N[(-6.0 / N[(N[(4.0 * N[Sqrt[x], $MachinePrecision]), $MachinePrecision] + N[(x + 1.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(6.0 / N[(1.0 - N[(-4.0 / N[Sqrt[x], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;x \leq 1:\\
\;\;\;\;\frac{-6}{4 \cdot \sqrt{x} + \left(x + 1\right)}\\

\mathbf{else}:\\
\;\;\;\;\frac{6}{1 - \frac{-4}{\sqrt{x}}}\\


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

    1. Initial program 99.9%

      \[\frac{6 \cdot \left(x - 1\right)}{\left(x + 1\right) + 4 \cdot \sqrt{x}} \]
    2. Add Preprocessing
    3. Taylor expanded in x around 0 97.9%

      \[\leadsto \frac{6 \cdot \color{blue}{-1}}{\left(x + 1\right) + 4 \cdot \sqrt{x}} \]

    if 1 < x

    1. Initial program 99.1%

      \[\frac{6 \cdot \left(x - 1\right)}{\left(x + 1\right) + 4 \cdot \sqrt{x}} \]
    2. Step-by-step derivation
      1. /-rgt-identity99.1%

        \[\leadsto \color{blue}{\frac{\frac{6 \cdot \left(x - 1\right)}{\left(x + 1\right) + 4 \cdot \sqrt{x}}}{1}} \]
      2. associate-/l/99.1%

        \[\leadsto \color{blue}{\frac{6 \cdot \left(x - 1\right)}{1 \cdot \left(\left(x + 1\right) + 4 \cdot \sqrt{x}\right)}} \]
      3. sub-neg99.1%

        \[\leadsto \frac{6 \cdot \color{blue}{\left(x + \left(-1\right)\right)}}{1 \cdot \left(\left(x + 1\right) + 4 \cdot \sqrt{x}\right)} \]
      4. distribute-lft-in99.1%

        \[\leadsto \frac{\color{blue}{6 \cdot x + 6 \cdot \left(-1\right)}}{1 \cdot \left(\left(x + 1\right) + 4 \cdot \sqrt{x}\right)} \]
      5. metadata-eval99.1%

        \[\leadsto \frac{6 \cdot x + 6 \cdot \color{blue}{-1}}{1 \cdot \left(\left(x + 1\right) + 4 \cdot \sqrt{x}\right)} \]
      6. metadata-eval99.1%

        \[\leadsto \frac{6 \cdot x + \color{blue}{-6}}{1 \cdot \left(\left(x + 1\right) + 4 \cdot \sqrt{x}\right)} \]
      7. metadata-eval99.1%

        \[\leadsto \frac{6 \cdot x + \color{blue}{\left(-6\right)}}{1 \cdot \left(\left(x + 1\right) + 4 \cdot \sqrt{x}\right)} \]
      8. fma-define99.1%

        \[\leadsto \frac{\color{blue}{\mathsf{fma}\left(6, x, -6\right)}}{1 \cdot \left(\left(x + 1\right) + 4 \cdot \sqrt{x}\right)} \]
      9. metadata-eval99.1%

        \[\leadsto \frac{\mathsf{fma}\left(6, x, \color{blue}{-6}\right)}{1 \cdot \left(\left(x + 1\right) + 4 \cdot \sqrt{x}\right)} \]
      10. *-lft-identity99.1%

        \[\leadsto \frac{\mathsf{fma}\left(6, x, -6\right)}{\color{blue}{\left(x + 1\right) + 4 \cdot \sqrt{x}}} \]
      11. +-commutative99.1%

        \[\leadsto \frac{\mathsf{fma}\left(6, x, -6\right)}{\color{blue}{\left(1 + x\right)} + 4 \cdot \sqrt{x}} \]
      12. associate-+l+99.1%

        \[\leadsto \frac{\mathsf{fma}\left(6, x, -6\right)}{\color{blue}{1 + \left(x + 4 \cdot \sqrt{x}\right)}} \]
      13. +-commutative99.1%

        \[\leadsto \frac{\mathsf{fma}\left(6, x, -6\right)}{1 + \color{blue}{\left(4 \cdot \sqrt{x} + x\right)}} \]
      14. fma-define99.1%

        \[\leadsto \frac{\mathsf{fma}\left(6, x, -6\right)}{1 + \color{blue}{\mathsf{fma}\left(4, \sqrt{x}, x\right)}} \]
    3. Simplified99.1%

      \[\leadsto \color{blue}{\frac{\mathsf{fma}\left(6, x, -6\right)}{1 + \mathsf{fma}\left(4, \sqrt{x}, x\right)}} \]
    4. Add Preprocessing
    5. Taylor expanded in x around inf 97.9%

      \[\leadsto \color{blue}{\frac{6}{1 + 4 \cdot \sqrt{\frac{1}{x}}}} \]
    6. Step-by-step derivation
      1. add-exp-log97.9%

        \[\leadsto \color{blue}{e^{\log \left(\frac{6}{1 + 4 \cdot \sqrt{\frac{1}{x}}}\right)}} \]
      2. log-div97.9%

        \[\leadsto e^{\color{blue}{\log 6 - \log \left(1 + 4 \cdot \sqrt{\frac{1}{x}}\right)}} \]
      3. log1p-define97.9%

        \[\leadsto e^{\log 6 - \color{blue}{\mathsf{log1p}\left(4 \cdot \sqrt{\frac{1}{x}}\right)}} \]
      4. sqrt-div97.9%

        \[\leadsto e^{\log 6 - \mathsf{log1p}\left(4 \cdot \color{blue}{\frac{\sqrt{1}}{\sqrt{x}}}\right)} \]
      5. metadata-eval97.9%

        \[\leadsto e^{\log 6 - \mathsf{log1p}\left(4 \cdot \frac{\color{blue}{1}}{\sqrt{x}}\right)} \]
      6. un-div-inv97.9%

        \[\leadsto e^{\log 6 - \mathsf{log1p}\left(\color{blue}{\frac{4}{\sqrt{x}}}\right)} \]
    7. Applied egg-rr97.9%

      \[\leadsto \color{blue}{e^{\log 6 - \mathsf{log1p}\left(\frac{4}{\sqrt{x}}\right)}} \]
    8. Step-by-step derivation
      1. exp-diff97.9%

        \[\leadsto \color{blue}{\frac{e^{\log 6}}{e^{\mathsf{log1p}\left(\frac{4}{\sqrt{x}}\right)}}} \]
      2. rem-exp-log97.9%

        \[\leadsto \frac{\color{blue}{6}}{e^{\mathsf{log1p}\left(\frac{4}{\sqrt{x}}\right)}} \]
      3. log1p-undefine97.9%

        \[\leadsto \frac{6}{e^{\color{blue}{\log \left(1 + \frac{4}{\sqrt{x}}\right)}}} \]
      4. rem-exp-log97.9%

        \[\leadsto \frac{6}{\color{blue}{1 + \frac{4}{\sqrt{x}}}} \]
      5. remove-double-neg97.9%

        \[\leadsto \frac{6}{1 + \color{blue}{\left(-\left(-\frac{4}{\sqrt{x}}\right)\right)}} \]
      6. unsub-neg97.9%

        \[\leadsto \frac{6}{\color{blue}{1 - \left(-\frac{4}{\sqrt{x}}\right)}} \]
      7. distribute-neg-frac97.9%

        \[\leadsto \frac{6}{1 - \color{blue}{\frac{-4}{\sqrt{x}}}} \]
      8. metadata-eval97.9%

        \[\leadsto \frac{6}{1 - \frac{\color{blue}{-4}}{\sqrt{x}}} \]
    9. Simplified97.9%

      \[\leadsto \color{blue}{\frac{6}{1 - \frac{-4}{\sqrt{x}}}} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification97.9%

    \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq 1:\\ \;\;\;\;\frac{-6}{4 \cdot \sqrt{x} + \left(x + 1\right)}\\ \mathbf{else}:\\ \;\;\;\;\frac{6}{1 - \frac{-4}{\sqrt{x}}}\\ \end{array} \]
  5. Add Preprocessing

Alternative 5: 97.8% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq 1:\\ \;\;\;\;\frac{-6}{1 + 4 \cdot \sqrt{x}}\\ \mathbf{else}:\\ \;\;\;\;\frac{6}{1 - \frac{-4}{\sqrt{x}}}\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (if (<= x 1.0)
   (/ -6.0 (+ 1.0 (* 4.0 (sqrt x))))
   (/ 6.0 (- 1.0 (/ -4.0 (sqrt x))))))
double code(double x) {
	double tmp;
	if (x <= 1.0) {
		tmp = -6.0 / (1.0 + (4.0 * sqrt(x)));
	} else {
		tmp = 6.0 / (1.0 - (-4.0 / sqrt(x)));
	}
	return tmp;
}
real(8) function code(x)
    real(8), intent (in) :: x
    real(8) :: tmp
    if (x <= 1.0d0) then
        tmp = (-6.0d0) / (1.0d0 + (4.0d0 * sqrt(x)))
    else
        tmp = 6.0d0 / (1.0d0 - ((-4.0d0) / sqrt(x)))
    end if
    code = tmp
end function
public static double code(double x) {
	double tmp;
	if (x <= 1.0) {
		tmp = -6.0 / (1.0 + (4.0 * Math.sqrt(x)));
	} else {
		tmp = 6.0 / (1.0 - (-4.0 / Math.sqrt(x)));
	}
	return tmp;
}
def code(x):
	tmp = 0
	if x <= 1.0:
		tmp = -6.0 / (1.0 + (4.0 * math.sqrt(x)))
	else:
		tmp = 6.0 / (1.0 - (-4.0 / math.sqrt(x)))
	return tmp
function code(x)
	tmp = 0.0
	if (x <= 1.0)
		tmp = Float64(-6.0 / Float64(1.0 + Float64(4.0 * sqrt(x))));
	else
		tmp = Float64(6.0 / Float64(1.0 - Float64(-4.0 / sqrt(x))));
	end
	return tmp
end
function tmp_2 = code(x)
	tmp = 0.0;
	if (x <= 1.0)
		tmp = -6.0 / (1.0 + (4.0 * sqrt(x)));
	else
		tmp = 6.0 / (1.0 - (-4.0 / sqrt(x)));
	end
	tmp_2 = tmp;
end
code[x_] := If[LessEqual[x, 1.0], N[(-6.0 / N[(1.0 + N[(4.0 * N[Sqrt[x], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(6.0 / N[(1.0 - N[(-4.0 / N[Sqrt[x], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;x \leq 1:\\
\;\;\;\;\frac{-6}{1 + 4 \cdot \sqrt{x}}\\

\mathbf{else}:\\
\;\;\;\;\frac{6}{1 - \frac{-4}{\sqrt{x}}}\\


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

    1. Initial program 99.9%

      \[\frac{6 \cdot \left(x - 1\right)}{\left(x + 1\right) + 4 \cdot \sqrt{x}} \]
    2. Step-by-step derivation
      1. /-rgt-identity99.9%

        \[\leadsto \color{blue}{\frac{\frac{6 \cdot \left(x - 1\right)}{\left(x + 1\right) + 4 \cdot \sqrt{x}}}{1}} \]
      2. associate-/l/99.9%

        \[\leadsto \color{blue}{\frac{6 \cdot \left(x - 1\right)}{1 \cdot \left(\left(x + 1\right) + 4 \cdot \sqrt{x}\right)}} \]
      3. sub-neg99.9%

        \[\leadsto \frac{6 \cdot \color{blue}{\left(x + \left(-1\right)\right)}}{1 \cdot \left(\left(x + 1\right) + 4 \cdot \sqrt{x}\right)} \]
      4. distribute-lft-in99.9%

        \[\leadsto \frac{\color{blue}{6 \cdot x + 6 \cdot \left(-1\right)}}{1 \cdot \left(\left(x + 1\right) + 4 \cdot \sqrt{x}\right)} \]
      5. metadata-eval99.9%

        \[\leadsto \frac{6 \cdot x + 6 \cdot \color{blue}{-1}}{1 \cdot \left(\left(x + 1\right) + 4 \cdot \sqrt{x}\right)} \]
      6. metadata-eval99.9%

        \[\leadsto \frac{6 \cdot x + \color{blue}{-6}}{1 \cdot \left(\left(x + 1\right) + 4 \cdot \sqrt{x}\right)} \]
      7. metadata-eval99.9%

        \[\leadsto \frac{6 \cdot x + \color{blue}{\left(-6\right)}}{1 \cdot \left(\left(x + 1\right) + 4 \cdot \sqrt{x}\right)} \]
      8. fma-define99.9%

        \[\leadsto \frac{\color{blue}{\mathsf{fma}\left(6, x, -6\right)}}{1 \cdot \left(\left(x + 1\right) + 4 \cdot \sqrt{x}\right)} \]
      9. metadata-eval99.9%

        \[\leadsto \frac{\mathsf{fma}\left(6, x, \color{blue}{-6}\right)}{1 \cdot \left(\left(x + 1\right) + 4 \cdot \sqrt{x}\right)} \]
      10. *-lft-identity99.9%

        \[\leadsto \frac{\mathsf{fma}\left(6, x, -6\right)}{\color{blue}{\left(x + 1\right) + 4 \cdot \sqrt{x}}} \]
      11. +-commutative99.9%

        \[\leadsto \frac{\mathsf{fma}\left(6, x, -6\right)}{\color{blue}{\left(1 + x\right)} + 4 \cdot \sqrt{x}} \]
      12. associate-+l+99.9%

        \[\leadsto \frac{\mathsf{fma}\left(6, x, -6\right)}{\color{blue}{1 + \left(x + 4 \cdot \sqrt{x}\right)}} \]
      13. +-commutative99.9%

        \[\leadsto \frac{\mathsf{fma}\left(6, x, -6\right)}{1 + \color{blue}{\left(4 \cdot \sqrt{x} + x\right)}} \]
      14. fma-define99.9%

        \[\leadsto \frac{\mathsf{fma}\left(6, x, -6\right)}{1 + \color{blue}{\mathsf{fma}\left(4, \sqrt{x}, x\right)}} \]
    3. Simplified99.9%

      \[\leadsto \color{blue}{\frac{\mathsf{fma}\left(6, x, -6\right)}{1 + \mathsf{fma}\left(4, \sqrt{x}, x\right)}} \]
    4. Add Preprocessing
    5. Taylor expanded in x around 0 97.8%

      \[\leadsto \color{blue}{\frac{-6}{1 + 4 \cdot \sqrt{x}}} \]
    6. Step-by-step derivation
      1. *-commutative97.8%

        \[\leadsto \frac{-6}{1 + \color{blue}{\sqrt{x} \cdot 4}} \]
    7. Simplified97.8%

      \[\leadsto \color{blue}{\frac{-6}{1 + \sqrt{x} \cdot 4}} \]

    if 1 < x

    1. Initial program 99.1%

      \[\frac{6 \cdot \left(x - 1\right)}{\left(x + 1\right) + 4 \cdot \sqrt{x}} \]
    2. Step-by-step derivation
      1. /-rgt-identity99.1%

        \[\leadsto \color{blue}{\frac{\frac{6 \cdot \left(x - 1\right)}{\left(x + 1\right) + 4 \cdot \sqrt{x}}}{1}} \]
      2. associate-/l/99.1%

        \[\leadsto \color{blue}{\frac{6 \cdot \left(x - 1\right)}{1 \cdot \left(\left(x + 1\right) + 4 \cdot \sqrt{x}\right)}} \]
      3. sub-neg99.1%

        \[\leadsto \frac{6 \cdot \color{blue}{\left(x + \left(-1\right)\right)}}{1 \cdot \left(\left(x + 1\right) + 4 \cdot \sqrt{x}\right)} \]
      4. distribute-lft-in99.1%

        \[\leadsto \frac{\color{blue}{6 \cdot x + 6 \cdot \left(-1\right)}}{1 \cdot \left(\left(x + 1\right) + 4 \cdot \sqrt{x}\right)} \]
      5. metadata-eval99.1%

        \[\leadsto \frac{6 \cdot x + 6 \cdot \color{blue}{-1}}{1 \cdot \left(\left(x + 1\right) + 4 \cdot \sqrt{x}\right)} \]
      6. metadata-eval99.1%

        \[\leadsto \frac{6 \cdot x + \color{blue}{-6}}{1 \cdot \left(\left(x + 1\right) + 4 \cdot \sqrt{x}\right)} \]
      7. metadata-eval99.1%

        \[\leadsto \frac{6 \cdot x + \color{blue}{\left(-6\right)}}{1 \cdot \left(\left(x + 1\right) + 4 \cdot \sqrt{x}\right)} \]
      8. fma-define99.1%

        \[\leadsto \frac{\color{blue}{\mathsf{fma}\left(6, x, -6\right)}}{1 \cdot \left(\left(x + 1\right) + 4 \cdot \sqrt{x}\right)} \]
      9. metadata-eval99.1%

        \[\leadsto \frac{\mathsf{fma}\left(6, x, \color{blue}{-6}\right)}{1 \cdot \left(\left(x + 1\right) + 4 \cdot \sqrt{x}\right)} \]
      10. *-lft-identity99.1%

        \[\leadsto \frac{\mathsf{fma}\left(6, x, -6\right)}{\color{blue}{\left(x + 1\right) + 4 \cdot \sqrt{x}}} \]
      11. +-commutative99.1%

        \[\leadsto \frac{\mathsf{fma}\left(6, x, -6\right)}{\color{blue}{\left(1 + x\right)} + 4 \cdot \sqrt{x}} \]
      12. associate-+l+99.1%

        \[\leadsto \frac{\mathsf{fma}\left(6, x, -6\right)}{\color{blue}{1 + \left(x + 4 \cdot \sqrt{x}\right)}} \]
      13. +-commutative99.1%

        \[\leadsto \frac{\mathsf{fma}\left(6, x, -6\right)}{1 + \color{blue}{\left(4 \cdot \sqrt{x} + x\right)}} \]
      14. fma-define99.1%

        \[\leadsto \frac{\mathsf{fma}\left(6, x, -6\right)}{1 + \color{blue}{\mathsf{fma}\left(4, \sqrt{x}, x\right)}} \]
    3. Simplified99.1%

      \[\leadsto \color{blue}{\frac{\mathsf{fma}\left(6, x, -6\right)}{1 + \mathsf{fma}\left(4, \sqrt{x}, x\right)}} \]
    4. Add Preprocessing
    5. Taylor expanded in x around inf 97.9%

      \[\leadsto \color{blue}{\frac{6}{1 + 4 \cdot \sqrt{\frac{1}{x}}}} \]
    6. Step-by-step derivation
      1. add-exp-log97.9%

        \[\leadsto \color{blue}{e^{\log \left(\frac{6}{1 + 4 \cdot \sqrt{\frac{1}{x}}}\right)}} \]
      2. log-div97.9%

        \[\leadsto e^{\color{blue}{\log 6 - \log \left(1 + 4 \cdot \sqrt{\frac{1}{x}}\right)}} \]
      3. log1p-define97.9%

        \[\leadsto e^{\log 6 - \color{blue}{\mathsf{log1p}\left(4 \cdot \sqrt{\frac{1}{x}}\right)}} \]
      4. sqrt-div97.9%

        \[\leadsto e^{\log 6 - \mathsf{log1p}\left(4 \cdot \color{blue}{\frac{\sqrt{1}}{\sqrt{x}}}\right)} \]
      5. metadata-eval97.9%

        \[\leadsto e^{\log 6 - \mathsf{log1p}\left(4 \cdot \frac{\color{blue}{1}}{\sqrt{x}}\right)} \]
      6. un-div-inv97.9%

        \[\leadsto e^{\log 6 - \mathsf{log1p}\left(\color{blue}{\frac{4}{\sqrt{x}}}\right)} \]
    7. Applied egg-rr97.9%

      \[\leadsto \color{blue}{e^{\log 6 - \mathsf{log1p}\left(\frac{4}{\sqrt{x}}\right)}} \]
    8. Step-by-step derivation
      1. exp-diff97.9%

        \[\leadsto \color{blue}{\frac{e^{\log 6}}{e^{\mathsf{log1p}\left(\frac{4}{\sqrt{x}}\right)}}} \]
      2. rem-exp-log97.9%

        \[\leadsto \frac{\color{blue}{6}}{e^{\mathsf{log1p}\left(\frac{4}{\sqrt{x}}\right)}} \]
      3. log1p-undefine97.9%

        \[\leadsto \frac{6}{e^{\color{blue}{\log \left(1 + \frac{4}{\sqrt{x}}\right)}}} \]
      4. rem-exp-log97.9%

        \[\leadsto \frac{6}{\color{blue}{1 + \frac{4}{\sqrt{x}}}} \]
      5. remove-double-neg97.9%

        \[\leadsto \frac{6}{1 + \color{blue}{\left(-\left(-\frac{4}{\sqrt{x}}\right)\right)}} \]
      6. unsub-neg97.9%

        \[\leadsto \frac{6}{\color{blue}{1 - \left(-\frac{4}{\sqrt{x}}\right)}} \]
      7. distribute-neg-frac97.9%

        \[\leadsto \frac{6}{1 - \color{blue}{\frac{-4}{\sqrt{x}}}} \]
      8. metadata-eval97.9%

        \[\leadsto \frac{6}{1 - \frac{\color{blue}{-4}}{\sqrt{x}}} \]
    9. Simplified97.9%

      \[\leadsto \color{blue}{\frac{6}{1 - \frac{-4}{\sqrt{x}}}} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification97.8%

    \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq 1:\\ \;\;\;\;\frac{-6}{1 + 4 \cdot \sqrt{x}}\\ \mathbf{else}:\\ \;\;\;\;\frac{6}{1 - \frac{-4}{\sqrt{x}}}\\ \end{array} \]
  5. Add Preprocessing

Alternative 6: 7.0% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq 1:\\ \;\;\;\;\frac{-1.5}{\sqrt{x}}\\ \mathbf{else}:\\ \;\;\;\;\sqrt{x \cdot 2.25}\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (if (<= x 1.0) (/ -1.5 (sqrt x)) (sqrt (* x 2.25))))
double code(double x) {
	double tmp;
	if (x <= 1.0) {
		tmp = -1.5 / sqrt(x);
	} else {
		tmp = sqrt((x * 2.25));
	}
	return tmp;
}
real(8) function code(x)
    real(8), intent (in) :: x
    real(8) :: tmp
    if (x <= 1.0d0) then
        tmp = (-1.5d0) / sqrt(x)
    else
        tmp = sqrt((x * 2.25d0))
    end if
    code = tmp
end function
public static double code(double x) {
	double tmp;
	if (x <= 1.0) {
		tmp = -1.5 / Math.sqrt(x);
	} else {
		tmp = Math.sqrt((x * 2.25));
	}
	return tmp;
}
def code(x):
	tmp = 0
	if x <= 1.0:
		tmp = -1.5 / math.sqrt(x)
	else:
		tmp = math.sqrt((x * 2.25))
	return tmp
function code(x)
	tmp = 0.0
	if (x <= 1.0)
		tmp = Float64(-1.5 / sqrt(x));
	else
		tmp = sqrt(Float64(x * 2.25));
	end
	return tmp
end
function tmp_2 = code(x)
	tmp = 0.0;
	if (x <= 1.0)
		tmp = -1.5 / sqrt(x);
	else
		tmp = sqrt((x * 2.25));
	end
	tmp_2 = tmp;
end
code[x_] := If[LessEqual[x, 1.0], N[(-1.5 / N[Sqrt[x], $MachinePrecision]), $MachinePrecision], N[Sqrt[N[(x * 2.25), $MachinePrecision]], $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;x \leq 1:\\
\;\;\;\;\frac{-1.5}{\sqrt{x}}\\

\mathbf{else}:\\
\;\;\;\;\sqrt{x \cdot 2.25}\\


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

    1. Initial program 99.9%

      \[\frac{6 \cdot \left(x - 1\right)}{\left(x + 1\right) + 4 \cdot \sqrt{x}} \]
    2. Step-by-step derivation
      1. /-rgt-identity99.9%

        \[\leadsto \color{blue}{\frac{\frac{6 \cdot \left(x - 1\right)}{\left(x + 1\right) + 4 \cdot \sqrt{x}}}{1}} \]
      2. associate-/l/99.9%

        \[\leadsto \color{blue}{\frac{6 \cdot \left(x - 1\right)}{1 \cdot \left(\left(x + 1\right) + 4 \cdot \sqrt{x}\right)}} \]
      3. sub-neg99.9%

        \[\leadsto \frac{6 \cdot \color{blue}{\left(x + \left(-1\right)\right)}}{1 \cdot \left(\left(x + 1\right) + 4 \cdot \sqrt{x}\right)} \]
      4. distribute-lft-in99.9%

        \[\leadsto \frac{\color{blue}{6 \cdot x + 6 \cdot \left(-1\right)}}{1 \cdot \left(\left(x + 1\right) + 4 \cdot \sqrt{x}\right)} \]
      5. metadata-eval99.9%

        \[\leadsto \frac{6 \cdot x + 6 \cdot \color{blue}{-1}}{1 \cdot \left(\left(x + 1\right) + 4 \cdot \sqrt{x}\right)} \]
      6. metadata-eval99.9%

        \[\leadsto \frac{6 \cdot x + \color{blue}{-6}}{1 \cdot \left(\left(x + 1\right) + 4 \cdot \sqrt{x}\right)} \]
      7. metadata-eval99.9%

        \[\leadsto \frac{6 \cdot x + \color{blue}{\left(-6\right)}}{1 \cdot \left(\left(x + 1\right) + 4 \cdot \sqrt{x}\right)} \]
      8. fma-define99.9%

        \[\leadsto \frac{\color{blue}{\mathsf{fma}\left(6, x, -6\right)}}{1 \cdot \left(\left(x + 1\right) + 4 \cdot \sqrt{x}\right)} \]
      9. metadata-eval99.9%

        \[\leadsto \frac{\mathsf{fma}\left(6, x, \color{blue}{-6}\right)}{1 \cdot \left(\left(x + 1\right) + 4 \cdot \sqrt{x}\right)} \]
      10. *-lft-identity99.9%

        \[\leadsto \frac{\mathsf{fma}\left(6, x, -6\right)}{\color{blue}{\left(x + 1\right) + 4 \cdot \sqrt{x}}} \]
      11. +-commutative99.9%

        \[\leadsto \frac{\mathsf{fma}\left(6, x, -6\right)}{\color{blue}{\left(1 + x\right)} + 4 \cdot \sqrt{x}} \]
      12. associate-+l+99.9%

        \[\leadsto \frac{\mathsf{fma}\left(6, x, -6\right)}{\color{blue}{1 + \left(x + 4 \cdot \sqrt{x}\right)}} \]
      13. +-commutative99.9%

        \[\leadsto \frac{\mathsf{fma}\left(6, x, -6\right)}{1 + \color{blue}{\left(4 \cdot \sqrt{x} + x\right)}} \]
      14. fma-define99.9%

        \[\leadsto \frac{\mathsf{fma}\left(6, x, -6\right)}{1 + \color{blue}{\mathsf{fma}\left(4, \sqrt{x}, x\right)}} \]
    3. Simplified99.9%

      \[\leadsto \color{blue}{\frac{\mathsf{fma}\left(6, x, -6\right)}{1 + \mathsf{fma}\left(4, \sqrt{x}, x\right)}} \]
    4. Add Preprocessing
    5. Taylor expanded in x around 0 97.8%

      \[\leadsto \color{blue}{\frac{-6}{1 + 4 \cdot \sqrt{x}}} \]
    6. Step-by-step derivation
      1. *-commutative97.8%

        \[\leadsto \frac{-6}{1 + \color{blue}{\sqrt{x} \cdot 4}} \]
    7. Simplified97.8%

      \[\leadsto \color{blue}{\frac{-6}{1 + \sqrt{x} \cdot 4}} \]
    8. Taylor expanded in x around inf 7.2%

      \[\leadsto \color{blue}{-1.5 \cdot \sqrt{\frac{1}{x}}} \]
    9. Step-by-step derivation
      1. *-commutative7.2%

        \[\leadsto \color{blue}{\sqrt{\frac{1}{x}} \cdot -1.5} \]
    10. Simplified7.2%

      \[\leadsto \color{blue}{\sqrt{\frac{1}{x}} \cdot -1.5} \]
    11. Step-by-step derivation
      1. *-commutative7.2%

        \[\leadsto \color{blue}{-1.5 \cdot \sqrt{\frac{1}{x}}} \]
      2. sqrt-div7.2%

        \[\leadsto -1.5 \cdot \color{blue}{\frac{\sqrt{1}}{\sqrt{x}}} \]
      3. metadata-eval7.2%

        \[\leadsto -1.5 \cdot \frac{\color{blue}{1}}{\sqrt{x}} \]
      4. un-div-inv7.2%

        \[\leadsto \color{blue}{\frac{-1.5}{\sqrt{x}}} \]
    12. Applied egg-rr7.2%

      \[\leadsto \color{blue}{\frac{-1.5}{\sqrt{x}}} \]

    if 1 < x

    1. Initial program 99.1%

      \[\frac{6 \cdot \left(x - 1\right)}{\left(x + 1\right) + 4 \cdot \sqrt{x}} \]
    2. Add Preprocessing
    3. Taylor expanded in x around 0 6.9%

      \[\leadsto \frac{6 \cdot \left(x - 1\right)}{\color{blue}{1} + 4 \cdot \sqrt{x}} \]
    4. Taylor expanded in x around -inf 1.3%

      \[\leadsto \color{blue}{-1.5 \cdot \sqrt{x}} \]
    5. Step-by-step derivation
      1. *-commutative1.3%

        \[\leadsto \color{blue}{\sqrt{x} \cdot -1.5} \]
    6. Simplified1.3%

      \[\leadsto \color{blue}{\sqrt{x} \cdot -1.5} \]
    7. Step-by-step derivation
      1. pow11.3%

        \[\leadsto \color{blue}{{\left(\sqrt{x} \cdot -1.5\right)}^{1}} \]
      2. add-sqr-sqrt0.0%

        \[\leadsto {\color{blue}{\left(\sqrt{\sqrt{x} \cdot -1.5} \cdot \sqrt{\sqrt{x} \cdot -1.5}\right)}}^{1} \]
      3. sqrt-unprod6.9%

        \[\leadsto {\color{blue}{\left(\sqrt{\left(\sqrt{x} \cdot -1.5\right) \cdot \left(\sqrt{x} \cdot -1.5\right)}\right)}}^{1} \]
      4. swap-sqr6.9%

        \[\leadsto {\left(\sqrt{\color{blue}{\left(\sqrt{x} \cdot \sqrt{x}\right) \cdot \left(-1.5 \cdot -1.5\right)}}\right)}^{1} \]
      5. add-sqr-sqrt6.9%

        \[\leadsto {\left(\sqrt{\color{blue}{x} \cdot \left(-1.5 \cdot -1.5\right)}\right)}^{1} \]
      6. metadata-eval6.9%

        \[\leadsto {\left(\sqrt{x \cdot \color{blue}{2.25}}\right)}^{1} \]
    8. Applied egg-rr6.9%

      \[\leadsto \color{blue}{{\left(\sqrt{x \cdot 2.25}\right)}^{1}} \]
    9. Step-by-step derivation
      1. unpow16.9%

        \[\leadsto \color{blue}{\sqrt{x \cdot 2.25}} \]
    10. Simplified6.9%

      \[\leadsto \color{blue}{\sqrt{x \cdot 2.25}} \]
  3. Recombined 2 regimes into one program.
  4. Add Preprocessing

Alternative 7: 7.0% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq 1:\\ \;\;\;\;\sqrt{x} \cdot -1.5\\ \mathbf{else}:\\ \;\;\;\;\sqrt{x \cdot 2.25}\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (if (<= x 1.0) (* (sqrt x) -1.5) (sqrt (* x 2.25))))
double code(double x) {
	double tmp;
	if (x <= 1.0) {
		tmp = sqrt(x) * -1.5;
	} else {
		tmp = sqrt((x * 2.25));
	}
	return tmp;
}
real(8) function code(x)
    real(8), intent (in) :: x
    real(8) :: tmp
    if (x <= 1.0d0) then
        tmp = sqrt(x) * (-1.5d0)
    else
        tmp = sqrt((x * 2.25d0))
    end if
    code = tmp
end function
public static double code(double x) {
	double tmp;
	if (x <= 1.0) {
		tmp = Math.sqrt(x) * -1.5;
	} else {
		tmp = Math.sqrt((x * 2.25));
	}
	return tmp;
}
def code(x):
	tmp = 0
	if x <= 1.0:
		tmp = math.sqrt(x) * -1.5
	else:
		tmp = math.sqrt((x * 2.25))
	return tmp
function code(x)
	tmp = 0.0
	if (x <= 1.0)
		tmp = Float64(sqrt(x) * -1.5);
	else
		tmp = sqrt(Float64(x * 2.25));
	end
	return tmp
end
function tmp_2 = code(x)
	tmp = 0.0;
	if (x <= 1.0)
		tmp = sqrt(x) * -1.5;
	else
		tmp = sqrt((x * 2.25));
	end
	tmp_2 = tmp;
end
code[x_] := If[LessEqual[x, 1.0], N[(N[Sqrt[x], $MachinePrecision] * -1.5), $MachinePrecision], N[Sqrt[N[(x * 2.25), $MachinePrecision]], $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;x \leq 1:\\
\;\;\;\;\sqrt{x} \cdot -1.5\\

\mathbf{else}:\\
\;\;\;\;\sqrt{x \cdot 2.25}\\


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

    1. Initial program 99.9%

      \[\frac{6 \cdot \left(x - 1\right)}{\left(x + 1\right) + 4 \cdot \sqrt{x}} \]
    2. Add Preprocessing
    3. Taylor expanded in x around 0 97.9%

      \[\leadsto \frac{6 \cdot \left(x - 1\right)}{\color{blue}{1} + 4 \cdot \sqrt{x}} \]
    4. Taylor expanded in x around -inf 7.1%

      \[\leadsto \color{blue}{-1.5 \cdot \sqrt{x}} \]
    5. Step-by-step derivation
      1. *-commutative7.1%

        \[\leadsto \color{blue}{\sqrt{x} \cdot -1.5} \]
    6. Simplified7.1%

      \[\leadsto \color{blue}{\sqrt{x} \cdot -1.5} \]

    if 1 < x

    1. Initial program 99.1%

      \[\frac{6 \cdot \left(x - 1\right)}{\left(x + 1\right) + 4 \cdot \sqrt{x}} \]
    2. Add Preprocessing
    3. Taylor expanded in x around 0 6.9%

      \[\leadsto \frac{6 \cdot \left(x - 1\right)}{\color{blue}{1} + 4 \cdot \sqrt{x}} \]
    4. Taylor expanded in x around -inf 1.3%

      \[\leadsto \color{blue}{-1.5 \cdot \sqrt{x}} \]
    5. Step-by-step derivation
      1. *-commutative1.3%

        \[\leadsto \color{blue}{\sqrt{x} \cdot -1.5} \]
    6. Simplified1.3%

      \[\leadsto \color{blue}{\sqrt{x} \cdot -1.5} \]
    7. Step-by-step derivation
      1. pow11.3%

        \[\leadsto \color{blue}{{\left(\sqrt{x} \cdot -1.5\right)}^{1}} \]
      2. add-sqr-sqrt0.0%

        \[\leadsto {\color{blue}{\left(\sqrt{\sqrt{x} \cdot -1.5} \cdot \sqrt{\sqrt{x} \cdot -1.5}\right)}}^{1} \]
      3. sqrt-unprod6.9%

        \[\leadsto {\color{blue}{\left(\sqrt{\left(\sqrt{x} \cdot -1.5\right) \cdot \left(\sqrt{x} \cdot -1.5\right)}\right)}}^{1} \]
      4. swap-sqr6.9%

        \[\leadsto {\left(\sqrt{\color{blue}{\left(\sqrt{x} \cdot \sqrt{x}\right) \cdot \left(-1.5 \cdot -1.5\right)}}\right)}^{1} \]
      5. add-sqr-sqrt6.9%

        \[\leadsto {\left(\sqrt{\color{blue}{x} \cdot \left(-1.5 \cdot -1.5\right)}\right)}^{1} \]
      6. metadata-eval6.9%

        \[\leadsto {\left(\sqrt{x \cdot \color{blue}{2.25}}\right)}^{1} \]
    8. Applied egg-rr6.9%

      \[\leadsto \color{blue}{{\left(\sqrt{x \cdot 2.25}\right)}^{1}} \]
    9. Step-by-step derivation
      1. unpow16.9%

        \[\leadsto \color{blue}{\sqrt{x \cdot 2.25}} \]
    10. Simplified6.9%

      \[\leadsto \color{blue}{\sqrt{x \cdot 2.25}} \]
  3. Recombined 2 regimes into one program.
  4. Add Preprocessing

Alternative 8: 51.7% accurate, 1.1× speedup?

\[\begin{array}{l} \\ 6 \cdot \left(-1 + 4 \cdot \sqrt{x}\right) \end{array} \]
(FPCore (x) :precision binary64 (* 6.0 (+ -1.0 (* 4.0 (sqrt x)))))
double code(double x) {
	return 6.0 * (-1.0 + (4.0 * sqrt(x)));
}
real(8) function code(x)
    real(8), intent (in) :: x
    code = 6.0d0 * ((-1.0d0) + (4.0d0 * sqrt(x)))
end function
public static double code(double x) {
	return 6.0 * (-1.0 + (4.0 * Math.sqrt(x)));
}
def code(x):
	return 6.0 * (-1.0 + (4.0 * math.sqrt(x)))
function code(x)
	return Float64(6.0 * Float64(-1.0 + Float64(4.0 * sqrt(x))))
end
function tmp = code(x)
	tmp = 6.0 * (-1.0 + (4.0 * sqrt(x)));
end
code[x_] := N[(6.0 * N[(-1.0 + N[(4.0 * N[Sqrt[x], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
6 \cdot \left(-1 + 4 \cdot \sqrt{x}\right)
\end{array}
Derivation
  1. Initial program 99.5%

    \[\frac{6 \cdot \left(x - 1\right)}{\left(x + 1\right) + 4 \cdot \sqrt{x}} \]
  2. Step-by-step derivation
    1. /-rgt-identity99.5%

      \[\leadsto \color{blue}{\frac{\frac{6 \cdot \left(x - 1\right)}{\left(x + 1\right) + 4 \cdot \sqrt{x}}}{1}} \]
    2. associate-/l/99.5%

      \[\leadsto \color{blue}{\frac{6 \cdot \left(x - 1\right)}{1 \cdot \left(\left(x + 1\right) + 4 \cdot \sqrt{x}\right)}} \]
    3. sub-neg99.5%

      \[\leadsto \frac{6 \cdot \color{blue}{\left(x + \left(-1\right)\right)}}{1 \cdot \left(\left(x + 1\right) + 4 \cdot \sqrt{x}\right)} \]
    4. distribute-lft-in99.5%

      \[\leadsto \frac{\color{blue}{6 \cdot x + 6 \cdot \left(-1\right)}}{1 \cdot \left(\left(x + 1\right) + 4 \cdot \sqrt{x}\right)} \]
    5. metadata-eval99.5%

      \[\leadsto \frac{6 \cdot x + 6 \cdot \color{blue}{-1}}{1 \cdot \left(\left(x + 1\right) + 4 \cdot \sqrt{x}\right)} \]
    6. metadata-eval99.5%

      \[\leadsto \frac{6 \cdot x + \color{blue}{-6}}{1 \cdot \left(\left(x + 1\right) + 4 \cdot \sqrt{x}\right)} \]
    7. metadata-eval99.5%

      \[\leadsto \frac{6 \cdot x + \color{blue}{\left(-6\right)}}{1 \cdot \left(\left(x + 1\right) + 4 \cdot \sqrt{x}\right)} \]
    8. fma-define99.5%

      \[\leadsto \frac{\color{blue}{\mathsf{fma}\left(6, x, -6\right)}}{1 \cdot \left(\left(x + 1\right) + 4 \cdot \sqrt{x}\right)} \]
    9. metadata-eval99.5%

      \[\leadsto \frac{\mathsf{fma}\left(6, x, \color{blue}{-6}\right)}{1 \cdot \left(\left(x + 1\right) + 4 \cdot \sqrt{x}\right)} \]
    10. *-lft-identity99.5%

      \[\leadsto \frac{\mathsf{fma}\left(6, x, -6\right)}{\color{blue}{\left(x + 1\right) + 4 \cdot \sqrt{x}}} \]
    11. +-commutative99.5%

      \[\leadsto \frac{\mathsf{fma}\left(6, x, -6\right)}{\color{blue}{\left(1 + x\right)} + 4 \cdot \sqrt{x}} \]
    12. associate-+l+99.5%

      \[\leadsto \frac{\mathsf{fma}\left(6, x, -6\right)}{\color{blue}{1 + \left(x + 4 \cdot \sqrt{x}\right)}} \]
    13. +-commutative99.5%

      \[\leadsto \frac{\mathsf{fma}\left(6, x, -6\right)}{1 + \color{blue}{\left(4 \cdot \sqrt{x} + x\right)}} \]
    14. fma-define99.5%

      \[\leadsto \frac{\mathsf{fma}\left(6, x, -6\right)}{1 + \color{blue}{\mathsf{fma}\left(4, \sqrt{x}, x\right)}} \]
  3. Simplified99.5%

    \[\leadsto \color{blue}{\frac{\mathsf{fma}\left(6, x, -6\right)}{1 + \mathsf{fma}\left(4, \sqrt{x}, x\right)}} \]
  4. Add Preprocessing
  5. Taylor expanded in x around 0 50.2%

    \[\leadsto \color{blue}{\frac{-6}{1 + 4 \cdot \sqrt{x}}} \]
  6. Step-by-step derivation
    1. *-commutative50.2%

      \[\leadsto \frac{-6}{1 + \color{blue}{\sqrt{x} \cdot 4}} \]
  7. Simplified50.2%

    \[\leadsto \color{blue}{\frac{-6}{1 + \sqrt{x} \cdot 4}} \]
  8. Step-by-step derivation
    1. +-commutative50.2%

      \[\leadsto \frac{-6}{\color{blue}{\sqrt{x} \cdot 4 + 1}} \]
    2. *-commutative50.2%

      \[\leadsto \frac{-6}{\color{blue}{4 \cdot \sqrt{x}} + 1} \]
    3. flip-+50.2%

      \[\leadsto \frac{-6}{\color{blue}{\frac{\left(4 \cdot \sqrt{x}\right) \cdot \left(4 \cdot \sqrt{x}\right) - 1 \cdot 1}{4 \cdot \sqrt{x} - 1}}} \]
    4. *-commutative50.2%

      \[\leadsto \frac{-6}{\frac{\color{blue}{\left(\sqrt{x} \cdot 4\right)} \cdot \left(4 \cdot \sqrt{x}\right) - 1 \cdot 1}{4 \cdot \sqrt{x} - 1}} \]
    5. *-commutative50.2%

      \[\leadsto \frac{-6}{\frac{\left(\sqrt{x} \cdot 4\right) \cdot \color{blue}{\left(\sqrt{x} \cdot 4\right)} - 1 \cdot 1}{4 \cdot \sqrt{x} - 1}} \]
    6. swap-sqr50.2%

      \[\leadsto \frac{-6}{\frac{\color{blue}{\left(\sqrt{x} \cdot \sqrt{x}\right) \cdot \left(4 \cdot 4\right)} - 1 \cdot 1}{4 \cdot \sqrt{x} - 1}} \]
    7. add-sqr-sqrt50.2%

      \[\leadsto \frac{-6}{\frac{\color{blue}{x} \cdot \left(4 \cdot 4\right) - 1 \cdot 1}{4 \cdot \sqrt{x} - 1}} \]
    8. metadata-eval50.2%

      \[\leadsto \frac{-6}{\frac{x \cdot \color{blue}{16} - 1 \cdot 1}{4 \cdot \sqrt{x} - 1}} \]
    9. metadata-eval50.2%

      \[\leadsto \frac{-6}{\frac{x \cdot 16 - \color{blue}{1}}{4 \cdot \sqrt{x} - 1}} \]
  9. Applied egg-rr50.2%

    \[\leadsto \frac{-6}{\color{blue}{\frac{x \cdot 16 - 1}{4 \cdot \sqrt{x} - 1}}} \]
  10. Taylor expanded in x around 0 52.5%

    \[\leadsto \color{blue}{6 \cdot \left(4 \cdot \sqrt{x} - 1\right)} \]
  11. Final simplification52.5%

    \[\leadsto 6 \cdot \left(-1 + 4 \cdot \sqrt{x}\right) \]
  12. Add Preprocessing

Alternative 9: 4.4% accurate, 1.1× speedup?

\[\begin{array}{l} \\ \sqrt{x \cdot 2.25} \end{array} \]
(FPCore (x) :precision binary64 (sqrt (* x 2.25)))
double code(double x) {
	return sqrt((x * 2.25));
}
real(8) function code(x)
    real(8), intent (in) :: x
    code = sqrt((x * 2.25d0))
end function
public static double code(double x) {
	return Math.sqrt((x * 2.25));
}
def code(x):
	return math.sqrt((x * 2.25))
function code(x)
	return sqrt(Float64(x * 2.25))
end
function tmp = code(x)
	tmp = sqrt((x * 2.25));
end
code[x_] := N[Sqrt[N[(x * 2.25), $MachinePrecision]], $MachinePrecision]
\begin{array}{l}

\\
\sqrt{x \cdot 2.25}
\end{array}
Derivation
  1. Initial program 99.5%

    \[\frac{6 \cdot \left(x - 1\right)}{\left(x + 1\right) + 4 \cdot \sqrt{x}} \]
  2. Add Preprocessing
  3. Taylor expanded in x around 0 52.7%

    \[\leadsto \frac{6 \cdot \left(x - 1\right)}{\color{blue}{1} + 4 \cdot \sqrt{x}} \]
  4. Taylor expanded in x around -inf 4.2%

    \[\leadsto \color{blue}{-1.5 \cdot \sqrt{x}} \]
  5. Step-by-step derivation
    1. *-commutative4.2%

      \[\leadsto \color{blue}{\sqrt{x} \cdot -1.5} \]
  6. Simplified4.2%

    \[\leadsto \color{blue}{\sqrt{x} \cdot -1.5} \]
  7. Step-by-step derivation
    1. pow14.2%

      \[\leadsto \color{blue}{{\left(\sqrt{x} \cdot -1.5\right)}^{1}} \]
    2. add-sqr-sqrt0.0%

      \[\leadsto {\color{blue}{\left(\sqrt{\sqrt{x} \cdot -1.5} \cdot \sqrt{\sqrt{x} \cdot -1.5}\right)}}^{1} \]
    3. sqrt-unprod4.3%

      \[\leadsto {\color{blue}{\left(\sqrt{\left(\sqrt{x} \cdot -1.5\right) \cdot \left(\sqrt{x} \cdot -1.5\right)}\right)}}^{1} \]
    4. swap-sqr4.3%

      \[\leadsto {\left(\sqrt{\color{blue}{\left(\sqrt{x} \cdot \sqrt{x}\right) \cdot \left(-1.5 \cdot -1.5\right)}}\right)}^{1} \]
    5. add-sqr-sqrt4.3%

      \[\leadsto {\left(\sqrt{\color{blue}{x} \cdot \left(-1.5 \cdot -1.5\right)}\right)}^{1} \]
    6. metadata-eval4.3%

      \[\leadsto {\left(\sqrt{x \cdot \color{blue}{2.25}}\right)}^{1} \]
  8. Applied egg-rr4.3%

    \[\leadsto \color{blue}{{\left(\sqrt{x \cdot 2.25}\right)}^{1}} \]
  9. Step-by-step derivation
    1. unpow14.3%

      \[\leadsto \color{blue}{\sqrt{x \cdot 2.25}} \]
  10. Simplified4.3%

    \[\leadsto \color{blue}{\sqrt{x \cdot 2.25}} \]
  11. Add Preprocessing

Developer Target 1: 99.9% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \frac{6}{\frac{\left(x + 1\right) + 4 \cdot \sqrt{x}}{x - 1}} \end{array} \]
(FPCore (x)
 :precision binary64
 (/ 6.0 (/ (+ (+ x 1.0) (* 4.0 (sqrt x))) (- x 1.0))))
double code(double x) {
	return 6.0 / (((x + 1.0) + (4.0 * sqrt(x))) / (x - 1.0));
}
real(8) function code(x)
    real(8), intent (in) :: x
    code = 6.0d0 / (((x + 1.0d0) + (4.0d0 * sqrt(x))) / (x - 1.0d0))
end function
public static double code(double x) {
	return 6.0 / (((x + 1.0) + (4.0 * Math.sqrt(x))) / (x - 1.0));
}
def code(x):
	return 6.0 / (((x + 1.0) + (4.0 * math.sqrt(x))) / (x - 1.0))
function code(x)
	return Float64(6.0 / Float64(Float64(Float64(x + 1.0) + Float64(4.0 * sqrt(x))) / Float64(x - 1.0)))
end
function tmp = code(x)
	tmp = 6.0 / (((x + 1.0) + (4.0 * sqrt(x))) / (x - 1.0));
end
code[x_] := N[(6.0 / N[(N[(N[(x + 1.0), $MachinePrecision] + N[(4.0 * N[Sqrt[x], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[(x - 1.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{6}{\frac{\left(x + 1\right) + 4 \cdot \sqrt{x}}{x - 1}}
\end{array}

Reproduce

?
herbie shell --seed 2024170 
(FPCore (x)
  :name "Data.Approximate.Numerics:blog from approximate-0.2.2.1"
  :precision binary64

  :alt
  (! :herbie-platform default (/ 6 (/ (+ (+ x 1) (* 4 (sqrt x))) (- x 1))))

  (/ (* 6.0 (- x 1.0)) (+ (+ x 1.0) (* 4.0 (sqrt x)))))