Data.Approximate.Numerics:blog from approximate-0.2.2.1

Percentage Accurate: 99.7% → 99.9%
Time: 11.1s
Alternatives: 8
Speedup: 1.1×

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 8 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, 0.9× speedup?

\[\begin{array}{l} \\ \frac{6}{\frac{x + \mathsf{fma}\left(4, \sqrt{x}, 1\right)}{x + -1}} \end{array} \]
(FPCore (x)
 :precision binary64
 (/ 6.0 (/ (+ x (fma 4.0 (sqrt x) 1.0)) (+ x -1.0))))
double code(double x) {
	return 6.0 / ((x + fma(4.0, sqrt(x), 1.0)) / (x + -1.0));
}
function code(x)
	return Float64(6.0 / Float64(Float64(x + fma(4.0, sqrt(x), 1.0)) / Float64(x + -1.0)))
end
code[x_] := N[(6.0 / N[(N[(x + N[(4.0 * N[Sqrt[x], $MachinePrecision] + 1.0), $MachinePrecision]), $MachinePrecision] / N[(x + -1.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{6}{\frac{x + \mathsf{fma}\left(4, \sqrt{x}, 1\right)}{x + -1}}
\end{array}
Derivation
  1. Initial program 99.8%

    \[\frac{6 \cdot \left(x - 1\right)}{\left(x + 1\right) + 4 \cdot \sqrt{x}} \]
  2. Add Preprocessing
  3. Step-by-step derivation
    1. lift-/.f64N/A

      \[\leadsto \color{blue}{\frac{6 \cdot \left(x - 1\right)}{\left(x + 1\right) + 4 \cdot \sqrt{x}}} \]
    2. lift-*.f64N/A

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

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

      \[\leadsto 6 \cdot \color{blue}{\frac{1}{\frac{\left(x + 1\right) + 4 \cdot \sqrt{x}}{x - 1}}} \]
    5. un-div-invN/A

      \[\leadsto \color{blue}{\frac{6}{\frac{\left(x + 1\right) + 4 \cdot \sqrt{x}}{x - 1}}} \]
    6. lower-/.f64N/A

      \[\leadsto \color{blue}{\frac{6}{\frac{\left(x + 1\right) + 4 \cdot \sqrt{x}}{x - 1}}} \]
    7. lower-/.f6499.9

      \[\leadsto \frac{6}{\color{blue}{\frac{\left(x + 1\right) + 4 \cdot \sqrt{x}}{x - 1}}} \]
    8. lift-+.f64N/A

      \[\leadsto \frac{6}{\frac{\color{blue}{\left(x + 1\right) + 4 \cdot \sqrt{x}}}{x - 1}} \]
    9. lift-+.f64N/A

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

      \[\leadsto \frac{6}{\frac{\color{blue}{x + \left(1 + 4 \cdot \sqrt{x}\right)}}{x - 1}} \]
    11. lower-+.f64N/A

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

      \[\leadsto \frac{6}{\frac{x + \color{blue}{\left(4 \cdot \sqrt{x} + 1\right)}}{x - 1}} \]
    13. lift-*.f64N/A

      \[\leadsto \frac{6}{\frac{x + \left(\color{blue}{4 \cdot \sqrt{x}} + 1\right)}{x - 1}} \]
    14. lower-fma.f6499.9

      \[\leadsto \frac{6}{\frac{x + \color{blue}{\mathsf{fma}\left(4, \sqrt{x}, 1\right)}}{x - 1}} \]
    15. lift--.f64N/A

      \[\leadsto \frac{6}{\frac{x + \mathsf{fma}\left(4, \sqrt{x}, 1\right)}{\color{blue}{x - 1}}} \]
    16. sub-negN/A

      \[\leadsto \frac{6}{\frac{x + \mathsf{fma}\left(4, \sqrt{x}, 1\right)}{\color{blue}{x + \left(\mathsf{neg}\left(1\right)\right)}}} \]
    17. lower-+.f64N/A

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

      \[\leadsto \frac{6}{\frac{x + \mathsf{fma}\left(4, \sqrt{x}, 1\right)}{x + \color{blue}{-1}}} \]
  4. Applied rewrites99.9%

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

Alternative 2: 97.7% accurate, 0.5× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;\frac{6 \cdot \left(x + -1\right)}{\left(x + 1\right) + 4 \cdot \sqrt{x}} \leq -5:\\ \;\;\;\;\frac{-6}{1 + \mathsf{fma}\left(4, \sqrt{x}, x\right)}\\ \mathbf{else}:\\ \;\;\;\;\frac{\mathsf{fma}\left(x, -6, 6\right)}{\sqrt{x} \cdot -4 - x}\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (if (<= (/ (* 6.0 (+ x -1.0)) (+ (+ x 1.0) (* 4.0 (sqrt x)))) -5.0)
   (/ -6.0 (+ 1.0 (fma 4.0 (sqrt x) x)))
   (/ (fma x -6.0 6.0) (- (* (sqrt x) -4.0) x))))
double code(double x) {
	double tmp;
	if (((6.0 * (x + -1.0)) / ((x + 1.0) + (4.0 * sqrt(x)))) <= -5.0) {
		tmp = -6.0 / (1.0 + fma(4.0, sqrt(x), x));
	} else {
		tmp = fma(x, -6.0, 6.0) / ((sqrt(x) * -4.0) - x);
	}
	return tmp;
}
function code(x)
	tmp = 0.0
	if (Float64(Float64(6.0 * Float64(x + -1.0)) / Float64(Float64(x + 1.0) + Float64(4.0 * sqrt(x)))) <= -5.0)
		tmp = Float64(-6.0 / Float64(1.0 + fma(4.0, sqrt(x), x)));
	else
		tmp = Float64(fma(x, -6.0, 6.0) / Float64(Float64(sqrt(x) * -4.0) - x));
	end
	return tmp
end
code[x_] := If[LessEqual[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], -5.0], N[(-6.0 / N[(1.0 + N[(4.0 * N[Sqrt[x], $MachinePrecision] + x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(N[(x * -6.0 + 6.0), $MachinePrecision] / N[(N[(N[Sqrt[x], $MachinePrecision] * -4.0), $MachinePrecision] - x), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;\frac{6 \cdot \left(x + -1\right)}{\left(x + 1\right) + 4 \cdot \sqrt{x}} \leq -5:\\
\;\;\;\;\frac{-6}{1 + \mathsf{fma}\left(4, \sqrt{x}, x\right)}\\

\mathbf{else}:\\
\;\;\;\;\frac{\mathsf{fma}\left(x, -6, 6\right)}{\sqrt{x} \cdot -4 - x}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (/.f64 (*.f64 #s(literal 6 binary64) (-.f64 x #s(literal 1 binary64))) (+.f64 (+.f64 x #s(literal 1 binary64)) (*.f64 #s(literal 4 binary64) (sqrt.f64 x)))) < -5

    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

      \[\leadsto \frac{6 \cdot \left(x - 1\right)}{\color{blue}{1 + 4 \cdot \sqrt{x}}} \]
    4. Step-by-step derivation
      1. +-commutativeN/A

        \[\leadsto \frac{6 \cdot \left(x - 1\right)}{\color{blue}{4 \cdot \sqrt{x} + 1}} \]
      2. lower-fma.f64N/A

        \[\leadsto \frac{6 \cdot \left(x - 1\right)}{\color{blue}{\mathsf{fma}\left(4, \sqrt{x}, 1\right)}} \]
      3. lower-sqrt.f6498.8

        \[\leadsto \frac{6 \cdot \left(x - 1\right)}{\mathsf{fma}\left(4, \color{blue}{\sqrt{x}}, 1\right)} \]
    5. Applied rewrites98.8%

      \[\leadsto \frac{6 \cdot \left(x - 1\right)}{\color{blue}{\mathsf{fma}\left(4, \sqrt{x}, 1\right)}} \]
    6. Step-by-step derivation
      1. lift-*.f64N/A

        \[\leadsto \frac{\color{blue}{6 \cdot \left(x - 1\right)}}{\mathsf{fma}\left(4, \sqrt{x}, 1\right)} \]
      2. lift--.f64N/A

        \[\leadsto \frac{6 \cdot \color{blue}{\left(x - 1\right)}}{\mathsf{fma}\left(4, \sqrt{x}, 1\right)} \]
      3. sub-negN/A

        \[\leadsto \frac{6 \cdot \color{blue}{\left(x + \left(\mathsf{neg}\left(1\right)\right)\right)}}{\mathsf{fma}\left(4, \sqrt{x}, 1\right)} \]
      4. metadata-evalN/A

        \[\leadsto \frac{6 \cdot \left(x + \color{blue}{-1}\right)}{\mathsf{fma}\left(4, \sqrt{x}, 1\right)} \]
      5. distribute-rgt-inN/A

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

        \[\leadsto \frac{x \cdot 6 + \color{blue}{-6}}{\mathsf{fma}\left(4, \sqrt{x}, 1\right)} \]
      7. lower-fma.f6498.8

        \[\leadsto \frac{\color{blue}{\mathsf{fma}\left(x, 6, -6\right)}}{\mathsf{fma}\left(4, \sqrt{x}, 1\right)} \]
    7. Applied rewrites98.8%

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

      \[\leadsto \frac{\mathsf{fma}\left(x, 6, -6\right)}{\color{blue}{1 + \left(x + 4 \cdot \sqrt{x}\right)}} \]
    9. Step-by-step derivation
      1. lower-+.f64N/A

        \[\leadsto \frac{\mathsf{fma}\left(x, 6, -6\right)}{\color{blue}{1 + \left(x + 4 \cdot \sqrt{x}\right)}} \]
      2. +-commutativeN/A

        \[\leadsto \frac{\mathsf{fma}\left(x, 6, -6\right)}{1 + \color{blue}{\left(4 \cdot \sqrt{x} + x\right)}} \]
      3. lower-fma.f64N/A

        \[\leadsto \frac{\mathsf{fma}\left(x, 6, -6\right)}{1 + \color{blue}{\mathsf{fma}\left(4, \sqrt{x}, x\right)}} \]
      4. lower-sqrt.f6499.9

        \[\leadsto \frac{\mathsf{fma}\left(x, 6, -6\right)}{1 + \mathsf{fma}\left(4, \color{blue}{\sqrt{x}}, x\right)} \]
    10. Applied rewrites99.9%

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

      \[\leadsto \frac{\color{blue}{-6}}{1 + \mathsf{fma}\left(4, \sqrt{x}, x\right)} \]
    12. Step-by-step derivation
      1. Applied rewrites98.8%

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

      if -5 < (/.f64 (*.f64 #s(literal 6 binary64) (-.f64 x #s(literal 1 binary64))) (+.f64 (+.f64 x #s(literal 1 binary64)) (*.f64 #s(literal 4 binary64) (sqrt.f64 x))))

      1. Initial program 99.8%

        \[\frac{6 \cdot \left(x - 1\right)}{\left(x + 1\right) + 4 \cdot \sqrt{x}} \]
      2. Add Preprocessing
      3. Step-by-step derivation
        1. lift-/.f64N/A

          \[\leadsto \color{blue}{\frac{6 \cdot \left(x - 1\right)}{\left(x + 1\right) + 4 \cdot \sqrt{x}}} \]
        2. clear-numN/A

          \[\leadsto \color{blue}{\frac{1}{\frac{\left(x + 1\right) + 4 \cdot \sqrt{x}}{6 \cdot \left(x - 1\right)}}} \]
        3. lift-*.f64N/A

          \[\leadsto \frac{1}{\frac{\left(x + 1\right) + 4 \cdot \sqrt{x}}{\color{blue}{6 \cdot \left(x - 1\right)}}} \]
        4. associate-/r*N/A

          \[\leadsto \frac{1}{\color{blue}{\frac{\frac{\left(x + 1\right) + 4 \cdot \sqrt{x}}{6}}{x - 1}}} \]
        5. associate-/r/N/A

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

          \[\leadsto \color{blue}{\frac{6}{\left(x + 1\right) + 4 \cdot \sqrt{x}}} \cdot \left(x - 1\right) \]
        7. lower-*.f64N/A

          \[\leadsto \color{blue}{\frac{6}{\left(x + 1\right) + 4 \cdot \sqrt{x}} \cdot \left(x - 1\right)} \]
      4. Applied rewrites99.9%

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

        \[\leadsto \frac{-6}{\color{blue}{-4 \cdot \sqrt{x}} - x} \cdot \left(x + -1\right) \]
      6. Step-by-step derivation
        1. *-commutativeN/A

          \[\leadsto \frac{-6}{\color{blue}{\sqrt{x} \cdot -4} - x} \cdot \left(x + -1\right) \]
        2. lower-*.f64N/A

          \[\leadsto \frac{-6}{\color{blue}{\sqrt{x} \cdot -4} - x} \cdot \left(x + -1\right) \]
        3. lower-sqrt.f6496.7

          \[\leadsto \frac{-6}{\color{blue}{\sqrt{x}} \cdot -4 - x} \cdot \left(x + -1\right) \]
      7. Applied rewrites96.7%

        \[\leadsto \frac{-6}{\color{blue}{\sqrt{x} \cdot -4} - x} \cdot \left(x + -1\right) \]
      8. Step-by-step derivation
        1. lift-*.f64N/A

          \[\leadsto \color{blue}{\frac{-6}{\sqrt{x} \cdot -4 - x} \cdot \left(x + -1\right)} \]
        2. lift-/.f64N/A

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

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

          \[\leadsto \frac{\color{blue}{\left(\mathsf{neg}\left(6\right)\right)} \cdot \left(x + -1\right)}{\sqrt{x} \cdot -4 - x} \]
        5. distribute-lft-neg-inN/A

          \[\leadsto \frac{\color{blue}{\mathsf{neg}\left(6 \cdot \left(x + -1\right)\right)}}{\sqrt{x} \cdot -4 - x} \]
        6. lift-+.f64N/A

          \[\leadsto \frac{\mathsf{neg}\left(6 \cdot \color{blue}{\left(x + -1\right)}\right)}{\sqrt{x} \cdot -4 - x} \]
        7. metadata-evalN/A

          \[\leadsto \frac{\mathsf{neg}\left(6 \cdot \left(x + \color{blue}{\left(\mathsf{neg}\left(1\right)\right)}\right)\right)}{\sqrt{x} \cdot -4 - x} \]
        8. sub-negN/A

          \[\leadsto \frac{\mathsf{neg}\left(6 \cdot \color{blue}{\left(x - 1\right)}\right)}{\sqrt{x} \cdot -4 - x} \]
        9. lower-/.f64N/A

          \[\leadsto \color{blue}{\frac{\mathsf{neg}\left(6 \cdot \left(x - 1\right)\right)}{\sqrt{x} \cdot -4 - x}} \]
        10. sub-negN/A

          \[\leadsto \frac{\mathsf{neg}\left(6 \cdot \color{blue}{\left(x + \left(\mathsf{neg}\left(1\right)\right)\right)}\right)}{\sqrt{x} \cdot -4 - x} \]
        11. metadata-evalN/A

          \[\leadsto \frac{\mathsf{neg}\left(6 \cdot \left(x + \color{blue}{-1}\right)\right)}{\sqrt{x} \cdot -4 - x} \]
        12. lift-+.f64N/A

          \[\leadsto \frac{\mathsf{neg}\left(6 \cdot \color{blue}{\left(x + -1\right)}\right)}{\sqrt{x} \cdot -4 - x} \]
        13. distribute-lft-neg-inN/A

          \[\leadsto \frac{\color{blue}{\left(\mathsf{neg}\left(6\right)\right) \cdot \left(x + -1\right)}}{\sqrt{x} \cdot -4 - x} \]
        14. metadata-evalN/A

          \[\leadsto \frac{\color{blue}{-6} \cdot \left(x + -1\right)}{\sqrt{x} \cdot -4 - x} \]
        15. lift-+.f64N/A

          \[\leadsto \frac{-6 \cdot \color{blue}{\left(x + -1\right)}}{\sqrt{x} \cdot -4 - x} \]
        16. distribute-rgt-inN/A

          \[\leadsto \frac{\color{blue}{x \cdot -6 + -1 \cdot -6}}{\sqrt{x} \cdot -4 - x} \]
        17. metadata-evalN/A

          \[\leadsto \frac{x \cdot -6 + \color{blue}{6}}{\sqrt{x} \cdot -4 - x} \]
        18. lower-fma.f6496.6

          \[\leadsto \frac{\color{blue}{\mathsf{fma}\left(x, -6, 6\right)}}{\sqrt{x} \cdot -4 - x} \]
      9. Applied rewrites96.6%

        \[\leadsto \color{blue}{\frac{\mathsf{fma}\left(x, -6, 6\right)}{\sqrt{x} \cdot -4 - x}} \]
    13. Recombined 2 regimes into one program.
    14. Final simplification97.7%

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

    Alternative 3: 97.6% accurate, 0.5× speedup?

    \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;\frac{6 \cdot \left(x + -1\right)}{\left(x + 1\right) + 4 \cdot \sqrt{x}} \leq -5:\\ \;\;\;\;\frac{-6}{1 + \mathsf{fma}\left(4, \sqrt{x}, x\right)}\\ \mathbf{else}:\\ \;\;\;\;\frac{6 \cdot x}{\mathsf{fma}\left(\sqrt{x}, 4, x + 1\right)}\\ \end{array} \end{array} \]
    (FPCore (x)
     :precision binary64
     (if (<= (/ (* 6.0 (+ x -1.0)) (+ (+ x 1.0) (* 4.0 (sqrt x)))) -5.0)
       (/ -6.0 (+ 1.0 (fma 4.0 (sqrt x) x)))
       (/ (* 6.0 x) (fma (sqrt x) 4.0 (+ x 1.0)))))
    double code(double x) {
    	double tmp;
    	if (((6.0 * (x + -1.0)) / ((x + 1.0) + (4.0 * sqrt(x)))) <= -5.0) {
    		tmp = -6.0 / (1.0 + fma(4.0, sqrt(x), x));
    	} else {
    		tmp = (6.0 * x) / fma(sqrt(x), 4.0, (x + 1.0));
    	}
    	return tmp;
    }
    
    function code(x)
    	tmp = 0.0
    	if (Float64(Float64(6.0 * Float64(x + -1.0)) / Float64(Float64(x + 1.0) + Float64(4.0 * sqrt(x)))) <= -5.0)
    		tmp = Float64(-6.0 / Float64(1.0 + fma(4.0, sqrt(x), x)));
    	else
    		tmp = Float64(Float64(6.0 * x) / fma(sqrt(x), 4.0, Float64(x + 1.0)));
    	end
    	return tmp
    end
    
    code[x_] := If[LessEqual[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], -5.0], N[(-6.0 / N[(1.0 + N[(4.0 * N[Sqrt[x], $MachinePrecision] + x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(N[(6.0 * x), $MachinePrecision] / N[(N[Sqrt[x], $MachinePrecision] * 4.0 + N[(x + 1.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
    
    \begin{array}{l}
    
    \\
    \begin{array}{l}
    \mathbf{if}\;\frac{6 \cdot \left(x + -1\right)}{\left(x + 1\right) + 4 \cdot \sqrt{x}} \leq -5:\\
    \;\;\;\;\frac{-6}{1 + \mathsf{fma}\left(4, \sqrt{x}, x\right)}\\
    
    \mathbf{else}:\\
    \;\;\;\;\frac{6 \cdot x}{\mathsf{fma}\left(\sqrt{x}, 4, x + 1\right)}\\
    
    
    \end{array}
    \end{array}
    
    Derivation
    1. Split input into 2 regimes
    2. if (/.f64 (*.f64 #s(literal 6 binary64) (-.f64 x #s(literal 1 binary64))) (+.f64 (+.f64 x #s(literal 1 binary64)) (*.f64 #s(literal 4 binary64) (sqrt.f64 x)))) < -5

      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

        \[\leadsto \frac{6 \cdot \left(x - 1\right)}{\color{blue}{1 + 4 \cdot \sqrt{x}}} \]
      4. Step-by-step derivation
        1. +-commutativeN/A

          \[\leadsto \frac{6 \cdot \left(x - 1\right)}{\color{blue}{4 \cdot \sqrt{x} + 1}} \]
        2. lower-fma.f64N/A

          \[\leadsto \frac{6 \cdot \left(x - 1\right)}{\color{blue}{\mathsf{fma}\left(4, \sqrt{x}, 1\right)}} \]
        3. lower-sqrt.f6498.8

          \[\leadsto \frac{6 \cdot \left(x - 1\right)}{\mathsf{fma}\left(4, \color{blue}{\sqrt{x}}, 1\right)} \]
      5. Applied rewrites98.8%

        \[\leadsto \frac{6 \cdot \left(x - 1\right)}{\color{blue}{\mathsf{fma}\left(4, \sqrt{x}, 1\right)}} \]
      6. Step-by-step derivation
        1. lift-*.f64N/A

          \[\leadsto \frac{\color{blue}{6 \cdot \left(x - 1\right)}}{\mathsf{fma}\left(4, \sqrt{x}, 1\right)} \]
        2. lift--.f64N/A

          \[\leadsto \frac{6 \cdot \color{blue}{\left(x - 1\right)}}{\mathsf{fma}\left(4, \sqrt{x}, 1\right)} \]
        3. sub-negN/A

          \[\leadsto \frac{6 \cdot \color{blue}{\left(x + \left(\mathsf{neg}\left(1\right)\right)\right)}}{\mathsf{fma}\left(4, \sqrt{x}, 1\right)} \]
        4. metadata-evalN/A

          \[\leadsto \frac{6 \cdot \left(x + \color{blue}{-1}\right)}{\mathsf{fma}\left(4, \sqrt{x}, 1\right)} \]
        5. distribute-rgt-inN/A

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

          \[\leadsto \frac{x \cdot 6 + \color{blue}{-6}}{\mathsf{fma}\left(4, \sqrt{x}, 1\right)} \]
        7. lower-fma.f6498.8

          \[\leadsto \frac{\color{blue}{\mathsf{fma}\left(x, 6, -6\right)}}{\mathsf{fma}\left(4, \sqrt{x}, 1\right)} \]
      7. Applied rewrites98.8%

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

        \[\leadsto \frac{\mathsf{fma}\left(x, 6, -6\right)}{\color{blue}{1 + \left(x + 4 \cdot \sqrt{x}\right)}} \]
      9. Step-by-step derivation
        1. lower-+.f64N/A

          \[\leadsto \frac{\mathsf{fma}\left(x, 6, -6\right)}{\color{blue}{1 + \left(x + 4 \cdot \sqrt{x}\right)}} \]
        2. +-commutativeN/A

          \[\leadsto \frac{\mathsf{fma}\left(x, 6, -6\right)}{1 + \color{blue}{\left(4 \cdot \sqrt{x} + x\right)}} \]
        3. lower-fma.f64N/A

          \[\leadsto \frac{\mathsf{fma}\left(x, 6, -6\right)}{1 + \color{blue}{\mathsf{fma}\left(4, \sqrt{x}, x\right)}} \]
        4. lower-sqrt.f6499.9

          \[\leadsto \frac{\mathsf{fma}\left(x, 6, -6\right)}{1 + \mathsf{fma}\left(4, \color{blue}{\sqrt{x}}, x\right)} \]
      10. Applied rewrites99.9%

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

        \[\leadsto \frac{\color{blue}{-6}}{1 + \mathsf{fma}\left(4, \sqrt{x}, x\right)} \]
      12. Step-by-step derivation
        1. Applied rewrites98.8%

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

        if -5 < (/.f64 (*.f64 #s(literal 6 binary64) (-.f64 x #s(literal 1 binary64))) (+.f64 (+.f64 x #s(literal 1 binary64)) (*.f64 #s(literal 4 binary64) (sqrt.f64 x))))

        1. Initial program 99.8%

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

          \[\leadsto \frac{\color{blue}{6 \cdot x}}{\left(x + 1\right) + 4 \cdot \sqrt{x}} \]
        4. Step-by-step derivation
          1. lower-*.f6496.6

            \[\leadsto \frac{\color{blue}{6 \cdot x}}{\left(x + 1\right) + 4 \cdot \sqrt{x}} \]
        5. Applied rewrites96.6%

          \[\leadsto \frac{\color{blue}{6 \cdot x}}{\left(x + 1\right) + 4 \cdot \sqrt{x}} \]
        6. Step-by-step derivation
          1. lift-+.f64N/A

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

            \[\leadsto \frac{6 \cdot x}{\color{blue}{4 \cdot \sqrt{x} + \left(x + 1\right)}} \]
          3. lift-*.f64N/A

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

            \[\leadsto \frac{6 \cdot x}{\color{blue}{\sqrt{x} \cdot 4} + \left(x + 1\right)} \]
          5. lower-fma.f6496.6

            \[\leadsto \frac{6 \cdot x}{\color{blue}{\mathsf{fma}\left(\sqrt{x}, 4, x + 1\right)}} \]
        7. Applied rewrites96.6%

          \[\leadsto \frac{6 \cdot x}{\color{blue}{\mathsf{fma}\left(\sqrt{x}, 4, x + 1\right)}} \]
      13. Recombined 2 regimes into one program.
      14. Final simplification97.7%

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

      Alternative 4: 99.9% accurate, 1.1× speedup?

      \[\begin{array}{l} \\ \left(x + -1\right) \cdot \frac{6}{1 + \mathsf{fma}\left(4, \sqrt{x}, x\right)} \end{array} \]
      (FPCore (x)
       :precision binary64
       (* (+ x -1.0) (/ 6.0 (+ 1.0 (fma 4.0 (sqrt x) x)))))
      double code(double x) {
      	return (x + -1.0) * (6.0 / (1.0 + fma(4.0, sqrt(x), x)));
      }
      
      function code(x)
      	return Float64(Float64(x + -1.0) * Float64(6.0 / Float64(1.0 + fma(4.0, sqrt(x), x))))
      end
      
      code[x_] := N[(N[(x + -1.0), $MachinePrecision] * N[(6.0 / N[(1.0 + N[(4.0 * N[Sqrt[x], $MachinePrecision] + x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
      
      \begin{array}{l}
      
      \\
      \left(x + -1\right) \cdot \frac{6}{1 + \mathsf{fma}\left(4, \sqrt{x}, x\right)}
      \end{array}
      
      Derivation
      1. Initial program 99.8%

        \[\frac{6 \cdot \left(x - 1\right)}{\left(x + 1\right) + 4 \cdot \sqrt{x}} \]
      2. Add Preprocessing
      3. Step-by-step derivation
        1. lift-/.f64N/A

          \[\leadsto \color{blue}{\frac{6 \cdot \left(x - 1\right)}{\left(x + 1\right) + 4 \cdot \sqrt{x}}} \]
        2. lift-*.f64N/A

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

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

          \[\leadsto 6 \cdot \color{blue}{\frac{1}{\frac{\left(x + 1\right) + 4 \cdot \sqrt{x}}{x - 1}}} \]
        5. un-div-invN/A

          \[\leadsto \color{blue}{\frac{6}{\frac{\left(x + 1\right) + 4 \cdot \sqrt{x}}{x - 1}}} \]
        6. lower-/.f64N/A

          \[\leadsto \color{blue}{\frac{6}{\frac{\left(x + 1\right) + 4 \cdot \sqrt{x}}{x - 1}}} \]
        7. lower-/.f6499.9

          \[\leadsto \frac{6}{\color{blue}{\frac{\left(x + 1\right) + 4 \cdot \sqrt{x}}{x - 1}}} \]
        8. lift-+.f64N/A

          \[\leadsto \frac{6}{\frac{\color{blue}{\left(x + 1\right) + 4 \cdot \sqrt{x}}}{x - 1}} \]
        9. lift-+.f64N/A

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

          \[\leadsto \frac{6}{\frac{\color{blue}{x + \left(1 + 4 \cdot \sqrt{x}\right)}}{x - 1}} \]
        11. lower-+.f64N/A

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

          \[\leadsto \frac{6}{\frac{x + \color{blue}{\left(4 \cdot \sqrt{x} + 1\right)}}{x - 1}} \]
        13. lift-*.f64N/A

          \[\leadsto \frac{6}{\frac{x + \left(\color{blue}{4 \cdot \sqrt{x}} + 1\right)}{x - 1}} \]
        14. lower-fma.f6499.9

          \[\leadsto \frac{6}{\frac{x + \color{blue}{\mathsf{fma}\left(4, \sqrt{x}, 1\right)}}{x - 1}} \]
        15. lift--.f64N/A

          \[\leadsto \frac{6}{\frac{x + \mathsf{fma}\left(4, \sqrt{x}, 1\right)}{\color{blue}{x - 1}}} \]
        16. sub-negN/A

          \[\leadsto \frac{6}{\frac{x + \mathsf{fma}\left(4, \sqrt{x}, 1\right)}{\color{blue}{x + \left(\mathsf{neg}\left(1\right)\right)}}} \]
        17. lower-+.f64N/A

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

          \[\leadsto \frac{6}{\frac{x + \mathsf{fma}\left(4, \sqrt{x}, 1\right)}{x + \color{blue}{-1}}} \]
      4. Applied rewrites99.9%

        \[\leadsto \color{blue}{\frac{6}{\frac{x + \mathsf{fma}\left(4, \sqrt{x}, 1\right)}{x + -1}}} \]
      5. Step-by-step derivation
        1. lift-/.f64N/A

          \[\leadsto \color{blue}{\frac{6}{\frac{x + \mathsf{fma}\left(4, \sqrt{x}, 1\right)}{x + -1}}} \]
        2. lift-/.f64N/A

          \[\leadsto \frac{6}{\color{blue}{\frac{x + \mathsf{fma}\left(4, \sqrt{x}, 1\right)}{x + -1}}} \]
        3. associate-/r/N/A

          \[\leadsto \color{blue}{\frac{6}{x + \mathsf{fma}\left(4, \sqrt{x}, 1\right)} \cdot \left(x + -1\right)} \]
        4. lower-*.f64N/A

          \[\leadsto \color{blue}{\frac{6}{x + \mathsf{fma}\left(4, \sqrt{x}, 1\right)} \cdot \left(x + -1\right)} \]
        5. lift-+.f64N/A

          \[\leadsto \frac{6}{\color{blue}{x + \mathsf{fma}\left(4, \sqrt{x}, 1\right)}} \cdot \left(x + -1\right) \]
        6. lift-fma.f64N/A

          \[\leadsto \frac{6}{x + \color{blue}{\left(4 \cdot \sqrt{x} + 1\right)}} \cdot \left(x + -1\right) \]
        7. lift-*.f64N/A

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

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

          \[\leadsto \frac{6}{\color{blue}{\left(x + 1\right) + 4 \cdot \sqrt{x}}} \cdot \left(x + -1\right) \]
        10. lift-+.f64N/A

          \[\leadsto \frac{6}{\color{blue}{\left(x + 1\right)} + 4 \cdot \sqrt{x}} \cdot \left(x + -1\right) \]
        11. lift-+.f64N/A

          \[\leadsto \frac{6}{\color{blue}{\left(x + 1\right) + 4 \cdot \sqrt{x}}} \cdot \left(x + -1\right) \]
        12. lower-/.f6499.9

          \[\leadsto \color{blue}{\frac{6}{\left(x + 1\right) + 4 \cdot \sqrt{x}}} \cdot \left(x + -1\right) \]
        13. lift-+.f64N/A

          \[\leadsto \frac{6}{\color{blue}{\left(x + 1\right) + 4 \cdot \sqrt{x}}} \cdot \left(x + -1\right) \]
        14. lift-+.f64N/A

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

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

          \[\leadsto \frac{6}{\color{blue}{1 + \left(x + 4 \cdot \sqrt{x}\right)}} \cdot \left(x + -1\right) \]
        17. lower-+.f64N/A

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

          \[\leadsto \frac{6}{1 + \color{blue}{\left(4 \cdot \sqrt{x} + x\right)}} \cdot \left(x + -1\right) \]
        19. lift-*.f64N/A

          \[\leadsto \frac{6}{1 + \left(\color{blue}{4 \cdot \sqrt{x}} + x\right)} \cdot \left(x + -1\right) \]
        20. lower-fma.f6499.9

          \[\leadsto \frac{6}{1 + \color{blue}{\mathsf{fma}\left(4, \sqrt{x}, x\right)}} \cdot \left(x + -1\right) \]
      6. Applied rewrites99.9%

        \[\leadsto \color{blue}{\frac{6}{1 + \mathsf{fma}\left(4, \sqrt{x}, x\right)} \cdot \left(x + -1\right)} \]
      7. Final simplification99.9%

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

      Alternative 5: 99.9% accurate, 1.1× speedup?

      \[\begin{array}{l} \\ \left(x + -1\right) \cdot \frac{-6}{\mathsf{fma}\left(\sqrt{x}, -4, -1\right) - x} \end{array} \]
      (FPCore (x)
       :precision binary64
       (* (+ x -1.0) (/ -6.0 (- (fma (sqrt x) -4.0 -1.0) x))))
      double code(double x) {
      	return (x + -1.0) * (-6.0 / (fma(sqrt(x), -4.0, -1.0) - x));
      }
      
      function code(x)
      	return Float64(Float64(x + -1.0) * Float64(-6.0 / Float64(fma(sqrt(x), -4.0, -1.0) - x)))
      end
      
      code[x_] := N[(N[(x + -1.0), $MachinePrecision] * N[(-6.0 / N[(N[(N[Sqrt[x], $MachinePrecision] * -4.0 + -1.0), $MachinePrecision] - x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
      
      \begin{array}{l}
      
      \\
      \left(x + -1\right) \cdot \frac{-6}{\mathsf{fma}\left(\sqrt{x}, -4, -1\right) - x}
      \end{array}
      
      Derivation
      1. Initial program 99.8%

        \[\frac{6 \cdot \left(x - 1\right)}{\left(x + 1\right) + 4 \cdot \sqrt{x}} \]
      2. Add Preprocessing
      3. Step-by-step derivation
        1. lift-/.f64N/A

          \[\leadsto \color{blue}{\frac{6 \cdot \left(x - 1\right)}{\left(x + 1\right) + 4 \cdot \sqrt{x}}} \]
        2. clear-numN/A

          \[\leadsto \color{blue}{\frac{1}{\frac{\left(x + 1\right) + 4 \cdot \sqrt{x}}{6 \cdot \left(x - 1\right)}}} \]
        3. lift-*.f64N/A

          \[\leadsto \frac{1}{\frac{\left(x + 1\right) + 4 \cdot \sqrt{x}}{\color{blue}{6 \cdot \left(x - 1\right)}}} \]
        4. associate-/r*N/A

          \[\leadsto \frac{1}{\color{blue}{\frac{\frac{\left(x + 1\right) + 4 \cdot \sqrt{x}}{6}}{x - 1}}} \]
        5. associate-/r/N/A

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

          \[\leadsto \color{blue}{\frac{6}{\left(x + 1\right) + 4 \cdot \sqrt{x}}} \cdot \left(x - 1\right) \]
        7. lower-*.f64N/A

          \[\leadsto \color{blue}{\frac{6}{\left(x + 1\right) + 4 \cdot \sqrt{x}} \cdot \left(x - 1\right)} \]
      4. Applied rewrites99.9%

        \[\leadsto \color{blue}{\frac{-6}{\mathsf{fma}\left(\sqrt{x}, -4, -1\right) - x} \cdot \left(x + -1\right)} \]
      5. Final simplification99.9%

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

      Alternative 6: 99.7% accurate, 1.1× speedup?

      \[\begin{array}{l} \\ \frac{\mathsf{fma}\left(6, x, -6\right)}{1 + \mathsf{fma}\left(4, \sqrt{x}, x\right)} \end{array} \]
      (FPCore (x)
       :precision binary64
       (/ (fma 6.0 x -6.0) (+ 1.0 (fma 4.0 (sqrt x) x))))
      double code(double x) {
      	return fma(6.0, x, -6.0) / (1.0 + fma(4.0, sqrt(x), x));
      }
      
      function code(x)
      	return Float64(fma(6.0, x, -6.0) / Float64(1.0 + fma(4.0, sqrt(x), x)))
      end
      
      code[x_] := N[(N[(6.0 * x + -6.0), $MachinePrecision] / N[(1.0 + N[(4.0 * N[Sqrt[x], $MachinePrecision] + x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
      
      \begin{array}{l}
      
      \\
      \frac{\mathsf{fma}\left(6, x, -6\right)}{1 + \mathsf{fma}\left(4, \sqrt{x}, x\right)}
      \end{array}
      
      Derivation
      1. Initial program 99.8%

        \[\frac{6 \cdot \left(x - 1\right)}{\left(x + 1\right) + 4 \cdot \sqrt{x}} \]
      2. Add Preprocessing
      3. Step-by-step derivation
        1. lift-/.f64N/A

          \[\leadsto \color{blue}{\frac{6 \cdot \left(x - 1\right)}{\left(x + 1\right) + 4 \cdot \sqrt{x}}} \]
        2. lift-*.f64N/A

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

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

          \[\leadsto 6 \cdot \color{blue}{\frac{1}{\frac{\left(x + 1\right) + 4 \cdot \sqrt{x}}{x - 1}}} \]
        5. un-div-invN/A

          \[\leadsto \color{blue}{\frac{6}{\frac{\left(x + 1\right) + 4 \cdot \sqrt{x}}{x - 1}}} \]
        6. lower-/.f64N/A

          \[\leadsto \color{blue}{\frac{6}{\frac{\left(x + 1\right) + 4 \cdot \sqrt{x}}{x - 1}}} \]
        7. lower-/.f6499.9

          \[\leadsto \frac{6}{\color{blue}{\frac{\left(x + 1\right) + 4 \cdot \sqrt{x}}{x - 1}}} \]
        8. lift-+.f64N/A

          \[\leadsto \frac{6}{\frac{\color{blue}{\left(x + 1\right) + 4 \cdot \sqrt{x}}}{x - 1}} \]
        9. lift-+.f64N/A

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

          \[\leadsto \frac{6}{\frac{\color{blue}{x + \left(1 + 4 \cdot \sqrt{x}\right)}}{x - 1}} \]
        11. lower-+.f64N/A

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

          \[\leadsto \frac{6}{\frac{x + \color{blue}{\left(4 \cdot \sqrt{x} + 1\right)}}{x - 1}} \]
        13. lift-*.f64N/A

          \[\leadsto \frac{6}{\frac{x + \left(\color{blue}{4 \cdot \sqrt{x}} + 1\right)}{x - 1}} \]
        14. lower-fma.f6499.9

          \[\leadsto \frac{6}{\frac{x + \color{blue}{\mathsf{fma}\left(4, \sqrt{x}, 1\right)}}{x - 1}} \]
        15. lift--.f64N/A

          \[\leadsto \frac{6}{\frac{x + \mathsf{fma}\left(4, \sqrt{x}, 1\right)}{\color{blue}{x - 1}}} \]
        16. sub-negN/A

          \[\leadsto \frac{6}{\frac{x + \mathsf{fma}\left(4, \sqrt{x}, 1\right)}{\color{blue}{x + \left(\mathsf{neg}\left(1\right)\right)}}} \]
        17. lower-+.f64N/A

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

          \[\leadsto \frac{6}{\frac{x + \mathsf{fma}\left(4, \sqrt{x}, 1\right)}{x + \color{blue}{-1}}} \]
      4. Applied rewrites99.9%

        \[\leadsto \color{blue}{\frac{6}{\frac{x + \mathsf{fma}\left(4, \sqrt{x}, 1\right)}{x + -1}}} \]
      5. Step-by-step derivation
        1. lift-/.f64N/A

          \[\leadsto \color{blue}{\frac{6}{\frac{x + \mathsf{fma}\left(4, \sqrt{x}, 1\right)}{x + -1}}} \]
        2. lift-/.f64N/A

          \[\leadsto \frac{6}{\color{blue}{\frac{x + \mathsf{fma}\left(4, \sqrt{x}, 1\right)}{x + -1}}} \]
        3. associate-/r/N/A

          \[\leadsto \color{blue}{\frac{6}{x + \mathsf{fma}\left(4, \sqrt{x}, 1\right)} \cdot \left(x + -1\right)} \]
        4. lift-+.f64N/A

          \[\leadsto \frac{6}{\color{blue}{x + \mathsf{fma}\left(4, \sqrt{x}, 1\right)}} \cdot \left(x + -1\right) \]
        5. lift-fma.f64N/A

          \[\leadsto \frac{6}{x + \color{blue}{\left(4 \cdot \sqrt{x} + 1\right)}} \cdot \left(x + -1\right) \]
        6. lift-*.f64N/A

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

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

          \[\leadsto \frac{6}{\color{blue}{\left(x + 1\right) + 4 \cdot \sqrt{x}}} \cdot \left(x + -1\right) \]
        9. lift-+.f64N/A

          \[\leadsto \frac{6}{\color{blue}{\left(x + 1\right)} + 4 \cdot \sqrt{x}} \cdot \left(x + -1\right) \]
        10. lift-+.f64N/A

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

          \[\leadsto \color{blue}{\frac{6 \cdot \left(x + -1\right)}{\left(x + 1\right) + 4 \cdot \sqrt{x}}} \]
        12. lift-+.f64N/A

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

          \[\leadsto \frac{6 \cdot \left(x + \color{blue}{\left(\mathsf{neg}\left(1\right)\right)}\right)}{\left(x + 1\right) + 4 \cdot \sqrt{x}} \]
        14. sub-negN/A

          \[\leadsto \frac{6 \cdot \color{blue}{\left(x - 1\right)}}{\left(x + 1\right) + 4 \cdot \sqrt{x}} \]
        15. lift--.f64N/A

          \[\leadsto \frac{6 \cdot \color{blue}{\left(x - 1\right)}}{\left(x + 1\right) + 4 \cdot \sqrt{x}} \]
        16. lift-*.f64N/A

          \[\leadsto \frac{\color{blue}{6 \cdot \left(x - 1\right)}}{\left(x + 1\right) + 4 \cdot \sqrt{x}} \]
        17. lower-/.f6499.8

          \[\leadsto \color{blue}{\frac{6 \cdot \left(x - 1\right)}{\left(x + 1\right) + 4 \cdot \sqrt{x}}} \]
      6. Applied rewrites99.8%

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

      Alternative 7: 52.3% accurate, 1.2× speedup?

      \[\begin{array}{l} \\ \frac{\mathsf{fma}\left(x, 6, -6\right)}{\mathsf{fma}\left(4, \sqrt{x}, 1\right)} \end{array} \]
      (FPCore (x) :precision binary64 (/ (fma x 6.0 -6.0) (fma 4.0 (sqrt x) 1.0)))
      double code(double x) {
      	return fma(x, 6.0, -6.0) / fma(4.0, sqrt(x), 1.0);
      }
      
      function code(x)
      	return Float64(fma(x, 6.0, -6.0) / fma(4.0, sqrt(x), 1.0))
      end
      
      code[x_] := N[(N[(x * 6.0 + -6.0), $MachinePrecision] / N[(4.0 * N[Sqrt[x], $MachinePrecision] + 1.0), $MachinePrecision]), $MachinePrecision]
      
      \begin{array}{l}
      
      \\
      \frac{\mathsf{fma}\left(x, 6, -6\right)}{\mathsf{fma}\left(4, \sqrt{x}, 1\right)}
      \end{array}
      
      Derivation
      1. Initial program 99.8%

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

        \[\leadsto \frac{6 \cdot \left(x - 1\right)}{\color{blue}{1 + 4 \cdot \sqrt{x}}} \]
      4. Step-by-step derivation
        1. +-commutativeN/A

          \[\leadsto \frac{6 \cdot \left(x - 1\right)}{\color{blue}{4 \cdot \sqrt{x} + 1}} \]
        2. lower-fma.f64N/A

          \[\leadsto \frac{6 \cdot \left(x - 1\right)}{\color{blue}{\mathsf{fma}\left(4, \sqrt{x}, 1\right)}} \]
        3. lower-sqrt.f6451.6

          \[\leadsto \frac{6 \cdot \left(x - 1\right)}{\mathsf{fma}\left(4, \color{blue}{\sqrt{x}}, 1\right)} \]
      5. Applied rewrites51.6%

        \[\leadsto \frac{6 \cdot \left(x - 1\right)}{\color{blue}{\mathsf{fma}\left(4, \sqrt{x}, 1\right)}} \]
      6. Step-by-step derivation
        1. lift-*.f64N/A

          \[\leadsto \frac{\color{blue}{6 \cdot \left(x - 1\right)}}{\mathsf{fma}\left(4, \sqrt{x}, 1\right)} \]
        2. lift--.f64N/A

          \[\leadsto \frac{6 \cdot \color{blue}{\left(x - 1\right)}}{\mathsf{fma}\left(4, \sqrt{x}, 1\right)} \]
        3. sub-negN/A

          \[\leadsto \frac{6 \cdot \color{blue}{\left(x + \left(\mathsf{neg}\left(1\right)\right)\right)}}{\mathsf{fma}\left(4, \sqrt{x}, 1\right)} \]
        4. metadata-evalN/A

          \[\leadsto \frac{6 \cdot \left(x + \color{blue}{-1}\right)}{\mathsf{fma}\left(4, \sqrt{x}, 1\right)} \]
        5. distribute-rgt-inN/A

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

          \[\leadsto \frac{x \cdot 6 + \color{blue}{-6}}{\mathsf{fma}\left(4, \sqrt{x}, 1\right)} \]
        7. lower-fma.f6451.6

          \[\leadsto \frac{\color{blue}{\mathsf{fma}\left(x, 6, -6\right)}}{\mathsf{fma}\left(4, \sqrt{x}, 1\right)} \]
      7. Applied rewrites51.6%

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

      Alternative 8: 52.1% accurate, 2.4× speedup?

      \[\begin{array}{l} \\ \mathsf{fma}\left(\sqrt{x}, 24, -6\right) \end{array} \]
      (FPCore (x) :precision binary64 (fma (sqrt x) 24.0 -6.0))
      double code(double x) {
      	return fma(sqrt(x), 24.0, -6.0);
      }
      
      function code(x)
      	return fma(sqrt(x), 24.0, -6.0)
      end
      
      code[x_] := N[(N[Sqrt[x], $MachinePrecision] * 24.0 + -6.0), $MachinePrecision]
      
      \begin{array}{l}
      
      \\
      \mathsf{fma}\left(\sqrt{x}, 24, -6\right)
      \end{array}
      
      Derivation
      1. Initial program 99.8%

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

        \[\leadsto \color{blue}{\frac{-6}{1 + 4 \cdot \sqrt{x}}} \]
      4. Step-by-step derivation
        1. metadata-evalN/A

          \[\leadsto \frac{\color{blue}{\mathsf{neg}\left(6\right)}}{1 + 4 \cdot \sqrt{x}} \]
        2. distribute-neg-fracN/A

          \[\leadsto \color{blue}{\mathsf{neg}\left(\frac{6}{1 + 4 \cdot \sqrt{x}}\right)} \]
        3. distribute-neg-frac2N/A

          \[\leadsto \color{blue}{\frac{6}{\mathsf{neg}\left(\left(1 + 4 \cdot \sqrt{x}\right)\right)}} \]
        4. lower-/.f64N/A

          \[\leadsto \color{blue}{\frac{6}{\mathsf{neg}\left(\left(1 + 4 \cdot \sqrt{x}\right)\right)}} \]
        5. +-commutativeN/A

          \[\leadsto \frac{6}{\mathsf{neg}\left(\color{blue}{\left(4 \cdot \sqrt{x} + 1\right)}\right)} \]
        6. distribute-neg-inN/A

          \[\leadsto \frac{6}{\color{blue}{\left(\mathsf{neg}\left(4 \cdot \sqrt{x}\right)\right) + \left(\mathsf{neg}\left(1\right)\right)}} \]
        7. *-commutativeN/A

          \[\leadsto \frac{6}{\left(\mathsf{neg}\left(\color{blue}{\sqrt{x} \cdot 4}\right)\right) + \left(\mathsf{neg}\left(1\right)\right)} \]
        8. distribute-rgt-neg-inN/A

          \[\leadsto \frac{6}{\color{blue}{\sqrt{x} \cdot \left(\mathsf{neg}\left(4\right)\right)} + \left(\mathsf{neg}\left(1\right)\right)} \]
        9. metadata-evalN/A

          \[\leadsto \frac{6}{\sqrt{x} \cdot \color{blue}{-4} + \left(\mathsf{neg}\left(1\right)\right)} \]
        10. metadata-evalN/A

          \[\leadsto \frac{6}{\sqrt{x} \cdot \color{blue}{\left(4 \cdot -1\right)} + \left(\mathsf{neg}\left(1\right)\right)} \]
        11. metadata-evalN/A

          \[\leadsto \frac{6}{\sqrt{x} \cdot \left(4 \cdot -1\right) + \color{blue}{-1}} \]
        12. lower-fma.f64N/A

          \[\leadsto \frac{6}{\color{blue}{\mathsf{fma}\left(\sqrt{x}, 4 \cdot -1, -1\right)}} \]
        13. lower-sqrt.f64N/A

          \[\leadsto \frac{6}{\mathsf{fma}\left(\color{blue}{\sqrt{x}}, 4 \cdot -1, -1\right)} \]
        14. metadata-eval48.8

          \[\leadsto \frac{6}{\mathsf{fma}\left(\sqrt{x}, \color{blue}{-4}, -1\right)} \]
      5. Applied rewrites48.8%

        \[\leadsto \color{blue}{\frac{6}{\mathsf{fma}\left(\sqrt{x}, -4, -1\right)}} \]
      6. Step-by-step derivation
        1. Applied rewrites48.8%

          \[\leadsto \frac{6}{\mathsf{fma}\left(x, 16, -1\right)} \cdot \color{blue}{\mathsf{fma}\left(\sqrt{x}, -4, 1\right)} \]
        2. Taylor expanded in x around 0

          \[\leadsto -6 \cdot \color{blue}{\left(1 + -4 \cdot \sqrt{x}\right)} \]
        3. Step-by-step derivation
          1. Applied rewrites51.4%

            \[\leadsto \mathsf{fma}\left(\sqrt{x}, \color{blue}{24}, -6\right) \]
          2. Add Preprocessing

          Developer Target 1: 99.9% accurate, 0.9× 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 2024233 
          (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)))))