math.sqrt on complex, real part

Percentage Accurate: 41.5% → 83.2%
Time: 7.5s
Alternatives: 8
Speedup: 1.7×

Specification

?
\[\begin{array}{l} \\ 0.5 \cdot \sqrt{2 \cdot \left(\sqrt{re \cdot re + im \cdot im} + re\right)} \end{array} \]
(FPCore (re im)
 :precision binary64
 (* 0.5 (sqrt (* 2.0 (+ (sqrt (+ (* re re) (* im im))) re)))))
double code(double re, double im) {
	return 0.5 * sqrt((2.0 * (sqrt(((re * re) + (im * im))) + re)));
}
real(8) function code(re, im)
    real(8), intent (in) :: re
    real(8), intent (in) :: im
    code = 0.5d0 * sqrt((2.0d0 * (sqrt(((re * re) + (im * im))) + re)))
end function
public static double code(double re, double im) {
	return 0.5 * Math.sqrt((2.0 * (Math.sqrt(((re * re) + (im * im))) + re)));
}
def code(re, im):
	return 0.5 * math.sqrt((2.0 * (math.sqrt(((re * re) + (im * im))) + re)))
function code(re, im)
	return Float64(0.5 * sqrt(Float64(2.0 * Float64(sqrt(Float64(Float64(re * re) + Float64(im * im))) + re))))
end
function tmp = code(re, im)
	tmp = 0.5 * sqrt((2.0 * (sqrt(((re * re) + (im * im))) + re)));
end
code[re_, im_] := N[(0.5 * N[Sqrt[N[(2.0 * N[(N[Sqrt[N[(N[(re * re), $MachinePrecision] + N[(im * im), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] + re), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
0.5 \cdot \sqrt{2 \cdot \left(\sqrt{re \cdot re + im \cdot im} + re\right)}
\end{array}

Sampling outcomes in binary64 precision:

Local Percentage Accuracy vs ?

The average percentage accuracy by input value. Horizontal axis shows value of an input variable; the variable is choosen in the title. Vertical axis is accuracy; higher is better. Red represent the original program, while blue represents Herbie's suggestion. These can be toggled with buttons below the plot. The line is an average while dots represent individual samples.

Accuracy vs Speed?

Herbie found 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: 41.5% accurate, 1.0× speedup?

\[\begin{array}{l} \\ 0.5 \cdot \sqrt{2 \cdot \left(\sqrt{re \cdot re + im \cdot im} + re\right)} \end{array} \]
(FPCore (re im)
 :precision binary64
 (* 0.5 (sqrt (* 2.0 (+ (sqrt (+ (* re re) (* im im))) re)))))
double code(double re, double im) {
	return 0.5 * sqrt((2.0 * (sqrt(((re * re) + (im * im))) + re)));
}
real(8) function code(re, im)
    real(8), intent (in) :: re
    real(8), intent (in) :: im
    code = 0.5d0 * sqrt((2.0d0 * (sqrt(((re * re) + (im * im))) + re)))
end function
public static double code(double re, double im) {
	return 0.5 * Math.sqrt((2.0 * (Math.sqrt(((re * re) + (im * im))) + re)));
}
def code(re, im):
	return 0.5 * math.sqrt((2.0 * (math.sqrt(((re * re) + (im * im))) + re)))
function code(re, im)
	return Float64(0.5 * sqrt(Float64(2.0 * Float64(sqrt(Float64(Float64(re * re) + Float64(im * im))) + re))))
end
function tmp = code(re, im)
	tmp = 0.5 * sqrt((2.0 * (sqrt(((re * re) + (im * im))) + re)));
end
code[re_, im_] := N[(0.5 * N[Sqrt[N[(2.0 * N[(N[Sqrt[N[(N[(re * re), $MachinePrecision] + N[(im * im), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] + re), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
0.5 \cdot \sqrt{2 \cdot \left(\sqrt{re \cdot re + im \cdot im} + re\right)}
\end{array}

Alternative 1: 83.2% accurate, 0.4× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;re \leq -1 \cdot 10^{+160}:\\ \;\;\;\;\sqrt{\frac{-im}{\frac{re}{im}}} \cdot 0.5\\ \mathbf{else}:\\ \;\;\;\;\sqrt{\left(\mathsf{hypot}\left(im, re\right) + re\right) \cdot 2} \cdot 0.5\\ \end{array} \end{array} \]
(FPCore (re im)
 :precision binary64
 (if (<= re -1e+160)
   (* (sqrt (/ (- im) (/ re im))) 0.5)
   (* (sqrt (* (+ (hypot im re) re) 2.0)) 0.5)))
double code(double re, double im) {
	double tmp;
	if (re <= -1e+160) {
		tmp = sqrt((-im / (re / im))) * 0.5;
	} else {
		tmp = sqrt(((hypot(im, re) + re) * 2.0)) * 0.5;
	}
	return tmp;
}
public static double code(double re, double im) {
	double tmp;
	if (re <= -1e+160) {
		tmp = Math.sqrt((-im / (re / im))) * 0.5;
	} else {
		tmp = Math.sqrt(((Math.hypot(im, re) + re) * 2.0)) * 0.5;
	}
	return tmp;
}
def code(re, im):
	tmp = 0
	if re <= -1e+160:
		tmp = math.sqrt((-im / (re / im))) * 0.5
	else:
		tmp = math.sqrt(((math.hypot(im, re) + re) * 2.0)) * 0.5
	return tmp
function code(re, im)
	tmp = 0.0
	if (re <= -1e+160)
		tmp = Float64(sqrt(Float64(Float64(-im) / Float64(re / im))) * 0.5);
	else
		tmp = Float64(sqrt(Float64(Float64(hypot(im, re) + re) * 2.0)) * 0.5);
	end
	return tmp
end
function tmp_2 = code(re, im)
	tmp = 0.0;
	if (re <= -1e+160)
		tmp = sqrt((-im / (re / im))) * 0.5;
	else
		tmp = sqrt(((hypot(im, re) + re) * 2.0)) * 0.5;
	end
	tmp_2 = tmp;
end
code[re_, im_] := If[LessEqual[re, -1e+160], N[(N[Sqrt[N[((-im) / N[(re / im), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] * 0.5), $MachinePrecision], N[(N[Sqrt[N[(N[(N[Sqrt[im ^ 2 + re ^ 2], $MachinePrecision] + re), $MachinePrecision] * 2.0), $MachinePrecision]], $MachinePrecision] * 0.5), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;re \leq -1 \cdot 10^{+160}:\\
\;\;\;\;\sqrt{\frac{-im}{\frac{re}{im}}} \cdot 0.5\\

\mathbf{else}:\\
\;\;\;\;\sqrt{\left(\mathsf{hypot}\left(im, re\right) + re\right) \cdot 2} \cdot 0.5\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if re < -1.00000000000000001e160

    1. Initial program 2.8%

      \[0.5 \cdot \sqrt{2 \cdot \left(\sqrt{re \cdot re + im \cdot im} + re\right)} \]
    2. Add Preprocessing
    3. Taylor expanded in re around -inf

      \[\leadsto \frac{1}{2} \cdot \sqrt{\color{blue}{-1 \cdot \frac{{im}^{2}}{re}}} \]
    4. Step-by-step derivation
      1. mul-1-negN/A

        \[\leadsto \frac{1}{2} \cdot \sqrt{\color{blue}{\mathsf{neg}\left(\frac{{im}^{2}}{re}\right)}} \]
      2. unpow2N/A

        \[\leadsto \frac{1}{2} \cdot \sqrt{\mathsf{neg}\left(\frac{\color{blue}{im \cdot im}}{re}\right)} \]
      3. associate-/l*N/A

        \[\leadsto \frac{1}{2} \cdot \sqrt{\mathsf{neg}\left(\color{blue}{im \cdot \frac{im}{re}}\right)} \]
      4. distribute-lft-neg-inN/A

        \[\leadsto \frac{1}{2} \cdot \sqrt{\color{blue}{\left(\mathsf{neg}\left(im\right)\right) \cdot \frac{im}{re}}} \]
      5. mul-1-negN/A

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

        \[\leadsto \frac{1}{2} \cdot \sqrt{\color{blue}{\left(-1 \cdot im\right) \cdot \frac{im}{re}}} \]
      7. mul-1-negN/A

        \[\leadsto \frac{1}{2} \cdot \sqrt{\color{blue}{\left(\mathsf{neg}\left(im\right)\right)} \cdot \frac{im}{re}} \]
      8. lower-neg.f64N/A

        \[\leadsto \frac{1}{2} \cdot \sqrt{\color{blue}{\left(-im\right)} \cdot \frac{im}{re}} \]
      9. lower-/.f6474.9

        \[\leadsto 0.5 \cdot \sqrt{\left(-im\right) \cdot \color{blue}{\frac{im}{re}}} \]
    5. Applied rewrites74.9%

      \[\leadsto 0.5 \cdot \sqrt{\color{blue}{\left(-im\right) \cdot \frac{im}{re}}} \]
    6. Step-by-step derivation
      1. Applied rewrites75.1%

        \[\leadsto 0.5 \cdot \sqrt{\frac{-im}{\color{blue}{\frac{re}{im}}}} \]

      if -1.00000000000000001e160 < re

      1. Initial program 46.5%

        \[0.5 \cdot \sqrt{2 \cdot \left(\sqrt{re \cdot re + im \cdot im} + re\right)} \]
      2. Add Preprocessing
      3. Step-by-step derivation
        1. lift-*.f64N/A

          \[\leadsto \color{blue}{\frac{1}{2} \cdot \sqrt{2 \cdot \left(\sqrt{re \cdot re + im \cdot im} + re\right)}} \]
        2. *-commutativeN/A

          \[\leadsto \color{blue}{\sqrt{2 \cdot \left(\sqrt{re \cdot re + im \cdot im} + re\right)} \cdot \frac{1}{2}} \]
        3. lower-*.f6446.5

          \[\leadsto \color{blue}{\sqrt{2 \cdot \left(\sqrt{re \cdot re + im \cdot im} + re\right)} \cdot 0.5} \]
        4. lift-*.f64N/A

          \[\leadsto \sqrt{\color{blue}{2 \cdot \left(\sqrt{re \cdot re + im \cdot im} + re\right)}} \cdot \frac{1}{2} \]
        5. *-commutativeN/A

          \[\leadsto \sqrt{\color{blue}{\left(\sqrt{re \cdot re + im \cdot im} + re\right) \cdot 2}} \cdot \frac{1}{2} \]
        6. lower-*.f6446.5

          \[\leadsto \sqrt{\color{blue}{\left(\sqrt{re \cdot re + im \cdot im} + re\right) \cdot 2}} \cdot 0.5 \]
        7. lift-sqrt.f64N/A

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

          \[\leadsto \sqrt{\left(\sqrt{\color{blue}{re \cdot re + im \cdot im}} + re\right) \cdot 2} \cdot \frac{1}{2} \]
        9. +-commutativeN/A

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

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

          \[\leadsto \sqrt{\left(\sqrt{im \cdot im + \color{blue}{re \cdot re}} + re\right) \cdot 2} \cdot \frac{1}{2} \]
        12. lower-hypot.f6484.8

          \[\leadsto \sqrt{\left(\color{blue}{\mathsf{hypot}\left(im, re\right)} + re\right) \cdot 2} \cdot 0.5 \]
      4. Applied rewrites84.8%

        \[\leadsto \color{blue}{\sqrt{\left(\mathsf{hypot}\left(im, re\right) + re\right) \cdot 2} \cdot 0.5} \]
    7. Recombined 2 regimes into one program.
    8. Final simplification83.5%

      \[\leadsto \begin{array}{l} \mathbf{if}\;re \leq -1 \cdot 10^{+160}:\\ \;\;\;\;\sqrt{\frac{-im}{\frac{re}{im}}} \cdot 0.5\\ \mathbf{else}:\\ \;\;\;\;\sqrt{\left(\mathsf{hypot}\left(im, re\right) + re\right) \cdot 2} \cdot 0.5\\ \end{array} \]
    9. Add Preprocessing

    Alternative 2: 56.8% accurate, 0.7× speedup?

    \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;re \leq -3.7 \cdot 10^{+118}:\\ \;\;\;\;\sqrt{\frac{-im}{\frac{re}{im}}} \cdot 0.5\\ \mathbf{elif}\;re \leq 9 \cdot 10^{-147}:\\ \;\;\;\;\sqrt{\mathsf{fma}\left(\frac{re}{im} + 2, re, im \cdot 2\right)} \cdot 0.5\\ \mathbf{elif}\;re \leq 2.4 \cdot 10^{+148}:\\ \;\;\;\;\sqrt{\left(\sqrt{im \cdot im + re \cdot re} + re\right) \cdot 2} \cdot 0.5\\ \mathbf{else}:\\ \;\;\;\;\sqrt{\mathsf{fma}\left(\frac{im}{re}, \frac{im}{re}, 4\right) \cdot re} \cdot 0.5\\ \end{array} \end{array} \]
    (FPCore (re im)
     :precision binary64
     (if (<= re -3.7e+118)
       (* (sqrt (/ (- im) (/ re im))) 0.5)
       (if (<= re 9e-147)
         (* (sqrt (fma (+ (/ re im) 2.0) re (* im 2.0))) 0.5)
         (if (<= re 2.4e+148)
           (* (sqrt (* (+ (sqrt (+ (* im im) (* re re))) re) 2.0)) 0.5)
           (* (sqrt (* (fma (/ im re) (/ im re) 4.0) re)) 0.5)))))
    double code(double re, double im) {
    	double tmp;
    	if (re <= -3.7e+118) {
    		tmp = sqrt((-im / (re / im))) * 0.5;
    	} else if (re <= 9e-147) {
    		tmp = sqrt(fma(((re / im) + 2.0), re, (im * 2.0))) * 0.5;
    	} else if (re <= 2.4e+148) {
    		tmp = sqrt(((sqrt(((im * im) + (re * re))) + re) * 2.0)) * 0.5;
    	} else {
    		tmp = sqrt((fma((im / re), (im / re), 4.0) * re)) * 0.5;
    	}
    	return tmp;
    }
    
    function code(re, im)
    	tmp = 0.0
    	if (re <= -3.7e+118)
    		tmp = Float64(sqrt(Float64(Float64(-im) / Float64(re / im))) * 0.5);
    	elseif (re <= 9e-147)
    		tmp = Float64(sqrt(fma(Float64(Float64(re / im) + 2.0), re, Float64(im * 2.0))) * 0.5);
    	elseif (re <= 2.4e+148)
    		tmp = Float64(sqrt(Float64(Float64(sqrt(Float64(Float64(im * im) + Float64(re * re))) + re) * 2.0)) * 0.5);
    	else
    		tmp = Float64(sqrt(Float64(fma(Float64(im / re), Float64(im / re), 4.0) * re)) * 0.5);
    	end
    	return tmp
    end
    
    code[re_, im_] := If[LessEqual[re, -3.7e+118], N[(N[Sqrt[N[((-im) / N[(re / im), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] * 0.5), $MachinePrecision], If[LessEqual[re, 9e-147], N[(N[Sqrt[N[(N[(N[(re / im), $MachinePrecision] + 2.0), $MachinePrecision] * re + N[(im * 2.0), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] * 0.5), $MachinePrecision], If[LessEqual[re, 2.4e+148], N[(N[Sqrt[N[(N[(N[Sqrt[N[(N[(im * im), $MachinePrecision] + N[(re * re), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] + re), $MachinePrecision] * 2.0), $MachinePrecision]], $MachinePrecision] * 0.5), $MachinePrecision], N[(N[Sqrt[N[(N[(N[(im / re), $MachinePrecision] * N[(im / re), $MachinePrecision] + 4.0), $MachinePrecision] * re), $MachinePrecision]], $MachinePrecision] * 0.5), $MachinePrecision]]]]
    
    \begin{array}{l}
    
    \\
    \begin{array}{l}
    \mathbf{if}\;re \leq -3.7 \cdot 10^{+118}:\\
    \;\;\;\;\sqrt{\frac{-im}{\frac{re}{im}}} \cdot 0.5\\
    
    \mathbf{elif}\;re \leq 9 \cdot 10^{-147}:\\
    \;\;\;\;\sqrt{\mathsf{fma}\left(\frac{re}{im} + 2, re, im \cdot 2\right)} \cdot 0.5\\
    
    \mathbf{elif}\;re \leq 2.4 \cdot 10^{+148}:\\
    \;\;\;\;\sqrt{\left(\sqrt{im \cdot im + re \cdot re} + re\right) \cdot 2} \cdot 0.5\\
    
    \mathbf{else}:\\
    \;\;\;\;\sqrt{\mathsf{fma}\left(\frac{im}{re}, \frac{im}{re}, 4\right) \cdot re} \cdot 0.5\\
    
    
    \end{array}
    \end{array}
    
    Derivation
    1. Split input into 4 regimes
    2. if re < -3.69999999999999987e118

      1. Initial program 4.7%

        \[0.5 \cdot \sqrt{2 \cdot \left(\sqrt{re \cdot re + im \cdot im} + re\right)} \]
      2. Add Preprocessing
      3. Taylor expanded in re around -inf

        \[\leadsto \frac{1}{2} \cdot \sqrt{\color{blue}{-1 \cdot \frac{{im}^{2}}{re}}} \]
      4. Step-by-step derivation
        1. mul-1-negN/A

          \[\leadsto \frac{1}{2} \cdot \sqrt{\color{blue}{\mathsf{neg}\left(\frac{{im}^{2}}{re}\right)}} \]
        2. unpow2N/A

          \[\leadsto \frac{1}{2} \cdot \sqrt{\mathsf{neg}\left(\frac{\color{blue}{im \cdot im}}{re}\right)} \]
        3. associate-/l*N/A

          \[\leadsto \frac{1}{2} \cdot \sqrt{\mathsf{neg}\left(\color{blue}{im \cdot \frac{im}{re}}\right)} \]
        4. distribute-lft-neg-inN/A

          \[\leadsto \frac{1}{2} \cdot \sqrt{\color{blue}{\left(\mathsf{neg}\left(im\right)\right) \cdot \frac{im}{re}}} \]
        5. mul-1-negN/A

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

          \[\leadsto \frac{1}{2} \cdot \sqrt{\color{blue}{\left(-1 \cdot im\right) \cdot \frac{im}{re}}} \]
        7. mul-1-negN/A

          \[\leadsto \frac{1}{2} \cdot \sqrt{\color{blue}{\left(\mathsf{neg}\left(im\right)\right)} \cdot \frac{im}{re}} \]
        8. lower-neg.f64N/A

          \[\leadsto \frac{1}{2} \cdot \sqrt{\color{blue}{\left(-im\right)} \cdot \frac{im}{re}} \]
        9. lower-/.f6464.1

          \[\leadsto 0.5 \cdot \sqrt{\left(-im\right) \cdot \color{blue}{\frac{im}{re}}} \]
      5. Applied rewrites64.1%

        \[\leadsto 0.5 \cdot \sqrt{\color{blue}{\left(-im\right) \cdot \frac{im}{re}}} \]
      6. Step-by-step derivation
        1. Applied rewrites64.2%

          \[\leadsto 0.5 \cdot \sqrt{\frac{-im}{\color{blue}{\frac{re}{im}}}} \]

        if -3.69999999999999987e118 < re < 8.99999999999999946e-147

        1. Initial program 47.1%

          \[0.5 \cdot \sqrt{2 \cdot \left(\sqrt{re \cdot re + im \cdot im} + re\right)} \]
        2. Add Preprocessing
        3. Taylor expanded in re around 0

          \[\leadsto \frac{1}{2} \cdot \sqrt{\color{blue}{2 \cdot im + re \cdot \left(2 + \frac{re}{im}\right)}} \]
        4. Step-by-step derivation
          1. +-commutativeN/A

            \[\leadsto \frac{1}{2} \cdot \sqrt{\color{blue}{re \cdot \left(2 + \frac{re}{im}\right) + 2 \cdot im}} \]
          2. *-commutativeN/A

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

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

            \[\leadsto \frac{1}{2} \cdot \sqrt{\mathsf{fma}\left(\color{blue}{\frac{re}{im} + 2}, re, 2 \cdot im\right)} \]
          5. lower-+.f64N/A

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

            \[\leadsto \frac{1}{2} \cdot \sqrt{\mathsf{fma}\left(\color{blue}{\frac{re}{im}} + 2, re, 2 \cdot im\right)} \]
          7. lower-*.f6432.5

            \[\leadsto 0.5 \cdot \sqrt{\mathsf{fma}\left(\frac{re}{im} + 2, re, \color{blue}{2 \cdot im}\right)} \]
        5. Applied rewrites32.5%

          \[\leadsto 0.5 \cdot \sqrt{\color{blue}{\mathsf{fma}\left(\frac{re}{im} + 2, re, 2 \cdot im\right)}} \]

        if 8.99999999999999946e-147 < re < 2.39999999999999995e148

        1. Initial program 79.4%

          \[0.5 \cdot \sqrt{2 \cdot \left(\sqrt{re \cdot re + im \cdot im} + re\right)} \]
        2. Add Preprocessing

        if 2.39999999999999995e148 < re

        1. Initial program 4.2%

          \[0.5 \cdot \sqrt{2 \cdot \left(\sqrt{re \cdot re + im \cdot im} + re\right)} \]
        2. Add Preprocessing
        3. Taylor expanded in re around inf

          \[\leadsto \frac{1}{2} \cdot \sqrt{\color{blue}{re \cdot \left(4 + \frac{{im}^{2}}{{re}^{2}}\right)}} \]
        4. Step-by-step derivation
          1. *-commutativeN/A

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

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

            \[\leadsto \frac{1}{2} \cdot \sqrt{\color{blue}{\left(\frac{{im}^{2}}{{re}^{2}} + 4\right)} \cdot re} \]
          4. unpow2N/A

            \[\leadsto \frac{1}{2} \cdot \sqrt{\left(\frac{\color{blue}{im \cdot im}}{{re}^{2}} + 4\right) \cdot re} \]
          5. unpow2N/A

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

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

            \[\leadsto \frac{1}{2} \cdot \sqrt{\color{blue}{\mathsf{fma}\left(\frac{im}{re}, \frac{im}{re}, 4\right)} \cdot re} \]
          8. lower-/.f64N/A

            \[\leadsto \frac{1}{2} \cdot \sqrt{\mathsf{fma}\left(\color{blue}{\frac{im}{re}}, \frac{im}{re}, 4\right) \cdot re} \]
          9. lower-/.f6492.3

            \[\leadsto 0.5 \cdot \sqrt{\mathsf{fma}\left(\frac{im}{re}, \color{blue}{\frac{im}{re}}, 4\right) \cdot re} \]
        5. Applied rewrites92.3%

          \[\leadsto 0.5 \cdot \sqrt{\color{blue}{\mathsf{fma}\left(\frac{im}{re}, \frac{im}{re}, 4\right) \cdot re}} \]
      7. Recombined 4 regimes into one program.
      8. Final simplification56.6%

        \[\leadsto \begin{array}{l} \mathbf{if}\;re \leq -3.7 \cdot 10^{+118}:\\ \;\;\;\;\sqrt{\frac{-im}{\frac{re}{im}}} \cdot 0.5\\ \mathbf{elif}\;re \leq 9 \cdot 10^{-147}:\\ \;\;\;\;\sqrt{\mathsf{fma}\left(\frac{re}{im} + 2, re, im \cdot 2\right)} \cdot 0.5\\ \mathbf{elif}\;re \leq 2.4 \cdot 10^{+148}:\\ \;\;\;\;\sqrt{\left(\sqrt{im \cdot im + re \cdot re} + re\right) \cdot 2} \cdot 0.5\\ \mathbf{else}:\\ \;\;\;\;\sqrt{\mathsf{fma}\left(\frac{im}{re}, \frac{im}{re}, 4\right) \cdot re} \cdot 0.5\\ \end{array} \]
      9. Add Preprocessing

      Alternative 3: 56.8% accurate, 0.7× speedup?

      \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;re \leq -3.7 \cdot 10^{+118}:\\ \;\;\;\;\sqrt{\frac{-im}{\frac{re}{im}}} \cdot 0.5\\ \mathbf{elif}\;re \leq 9 \cdot 10^{-147}:\\ \;\;\;\;\sqrt{\mathsf{fma}\left(\frac{re}{im} + 2, re, im \cdot 2\right)} \cdot 0.5\\ \mathbf{elif}\;re \leq 2.4 \cdot 10^{+148}:\\ \;\;\;\;\sqrt{\left(\sqrt{im \cdot im + re \cdot re} + re\right) \cdot 2} \cdot 0.5\\ \mathbf{else}:\\ \;\;\;\;\sqrt{re}\\ \end{array} \end{array} \]
      (FPCore (re im)
       :precision binary64
       (if (<= re -3.7e+118)
         (* (sqrt (/ (- im) (/ re im))) 0.5)
         (if (<= re 9e-147)
           (* (sqrt (fma (+ (/ re im) 2.0) re (* im 2.0))) 0.5)
           (if (<= re 2.4e+148)
             (* (sqrt (* (+ (sqrt (+ (* im im) (* re re))) re) 2.0)) 0.5)
             (sqrt re)))))
      double code(double re, double im) {
      	double tmp;
      	if (re <= -3.7e+118) {
      		tmp = sqrt((-im / (re / im))) * 0.5;
      	} else if (re <= 9e-147) {
      		tmp = sqrt(fma(((re / im) + 2.0), re, (im * 2.0))) * 0.5;
      	} else if (re <= 2.4e+148) {
      		tmp = sqrt(((sqrt(((im * im) + (re * re))) + re) * 2.0)) * 0.5;
      	} else {
      		tmp = sqrt(re);
      	}
      	return tmp;
      }
      
      function code(re, im)
      	tmp = 0.0
      	if (re <= -3.7e+118)
      		tmp = Float64(sqrt(Float64(Float64(-im) / Float64(re / im))) * 0.5);
      	elseif (re <= 9e-147)
      		tmp = Float64(sqrt(fma(Float64(Float64(re / im) + 2.0), re, Float64(im * 2.0))) * 0.5);
      	elseif (re <= 2.4e+148)
      		tmp = Float64(sqrt(Float64(Float64(sqrt(Float64(Float64(im * im) + Float64(re * re))) + re) * 2.0)) * 0.5);
      	else
      		tmp = sqrt(re);
      	end
      	return tmp
      end
      
      code[re_, im_] := If[LessEqual[re, -3.7e+118], N[(N[Sqrt[N[((-im) / N[(re / im), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] * 0.5), $MachinePrecision], If[LessEqual[re, 9e-147], N[(N[Sqrt[N[(N[(N[(re / im), $MachinePrecision] + 2.0), $MachinePrecision] * re + N[(im * 2.0), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] * 0.5), $MachinePrecision], If[LessEqual[re, 2.4e+148], N[(N[Sqrt[N[(N[(N[Sqrt[N[(N[(im * im), $MachinePrecision] + N[(re * re), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] + re), $MachinePrecision] * 2.0), $MachinePrecision]], $MachinePrecision] * 0.5), $MachinePrecision], N[Sqrt[re], $MachinePrecision]]]]
      
      \begin{array}{l}
      
      \\
      \begin{array}{l}
      \mathbf{if}\;re \leq -3.7 \cdot 10^{+118}:\\
      \;\;\;\;\sqrt{\frac{-im}{\frac{re}{im}}} \cdot 0.5\\
      
      \mathbf{elif}\;re \leq 9 \cdot 10^{-147}:\\
      \;\;\;\;\sqrt{\mathsf{fma}\left(\frac{re}{im} + 2, re, im \cdot 2\right)} \cdot 0.5\\
      
      \mathbf{elif}\;re \leq 2.4 \cdot 10^{+148}:\\
      \;\;\;\;\sqrt{\left(\sqrt{im \cdot im + re \cdot re} + re\right) \cdot 2} \cdot 0.5\\
      
      \mathbf{else}:\\
      \;\;\;\;\sqrt{re}\\
      
      
      \end{array}
      \end{array}
      
      Derivation
      1. Split input into 4 regimes
      2. if re < -3.69999999999999987e118

        1. Initial program 4.7%

          \[0.5 \cdot \sqrt{2 \cdot \left(\sqrt{re \cdot re + im \cdot im} + re\right)} \]
        2. Add Preprocessing
        3. Taylor expanded in re around -inf

          \[\leadsto \frac{1}{2} \cdot \sqrt{\color{blue}{-1 \cdot \frac{{im}^{2}}{re}}} \]
        4. Step-by-step derivation
          1. mul-1-negN/A

            \[\leadsto \frac{1}{2} \cdot \sqrt{\color{blue}{\mathsf{neg}\left(\frac{{im}^{2}}{re}\right)}} \]
          2. unpow2N/A

            \[\leadsto \frac{1}{2} \cdot \sqrt{\mathsf{neg}\left(\frac{\color{blue}{im \cdot im}}{re}\right)} \]
          3. associate-/l*N/A

            \[\leadsto \frac{1}{2} \cdot \sqrt{\mathsf{neg}\left(\color{blue}{im \cdot \frac{im}{re}}\right)} \]
          4. distribute-lft-neg-inN/A

            \[\leadsto \frac{1}{2} \cdot \sqrt{\color{blue}{\left(\mathsf{neg}\left(im\right)\right) \cdot \frac{im}{re}}} \]
          5. mul-1-negN/A

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

            \[\leadsto \frac{1}{2} \cdot \sqrt{\color{blue}{\left(-1 \cdot im\right) \cdot \frac{im}{re}}} \]
          7. mul-1-negN/A

            \[\leadsto \frac{1}{2} \cdot \sqrt{\color{blue}{\left(\mathsf{neg}\left(im\right)\right)} \cdot \frac{im}{re}} \]
          8. lower-neg.f64N/A

            \[\leadsto \frac{1}{2} \cdot \sqrt{\color{blue}{\left(-im\right)} \cdot \frac{im}{re}} \]
          9. lower-/.f6464.1

            \[\leadsto 0.5 \cdot \sqrt{\left(-im\right) \cdot \color{blue}{\frac{im}{re}}} \]
        5. Applied rewrites64.1%

          \[\leadsto 0.5 \cdot \sqrt{\color{blue}{\left(-im\right) \cdot \frac{im}{re}}} \]
        6. Step-by-step derivation
          1. Applied rewrites64.2%

            \[\leadsto 0.5 \cdot \sqrt{\frac{-im}{\color{blue}{\frac{re}{im}}}} \]

          if -3.69999999999999987e118 < re < 8.99999999999999946e-147

          1. Initial program 47.1%

            \[0.5 \cdot \sqrt{2 \cdot \left(\sqrt{re \cdot re + im \cdot im} + re\right)} \]
          2. Add Preprocessing
          3. Taylor expanded in re around 0

            \[\leadsto \frac{1}{2} \cdot \sqrt{\color{blue}{2 \cdot im + re \cdot \left(2 + \frac{re}{im}\right)}} \]
          4. Step-by-step derivation
            1. +-commutativeN/A

              \[\leadsto \frac{1}{2} \cdot \sqrt{\color{blue}{re \cdot \left(2 + \frac{re}{im}\right) + 2 \cdot im}} \]
            2. *-commutativeN/A

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

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

              \[\leadsto \frac{1}{2} \cdot \sqrt{\mathsf{fma}\left(\color{blue}{\frac{re}{im} + 2}, re, 2 \cdot im\right)} \]
            5. lower-+.f64N/A

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

              \[\leadsto \frac{1}{2} \cdot \sqrt{\mathsf{fma}\left(\color{blue}{\frac{re}{im}} + 2, re, 2 \cdot im\right)} \]
            7. lower-*.f6432.5

              \[\leadsto 0.5 \cdot \sqrt{\mathsf{fma}\left(\frac{re}{im} + 2, re, \color{blue}{2 \cdot im}\right)} \]
          5. Applied rewrites32.5%

            \[\leadsto 0.5 \cdot \sqrt{\color{blue}{\mathsf{fma}\left(\frac{re}{im} + 2, re, 2 \cdot im\right)}} \]

          if 8.99999999999999946e-147 < re < 2.39999999999999995e148

          1. Initial program 79.4%

            \[0.5 \cdot \sqrt{2 \cdot \left(\sqrt{re \cdot re + im \cdot im} + re\right)} \]
          2. Add Preprocessing

          if 2.39999999999999995e148 < re

          1. Initial program 4.2%

            \[0.5 \cdot \sqrt{2 \cdot \left(\sqrt{re \cdot re + im \cdot im} + re\right)} \]
          2. Add Preprocessing
          3. Taylor expanded in re around inf

            \[\leadsto \color{blue}{\frac{1}{2} \cdot \left(\sqrt{re} \cdot {\left(\sqrt{2}\right)}^{2}\right)} \]
          4. Step-by-step derivation
            1. *-commutativeN/A

              \[\leadsto \frac{1}{2} \cdot \color{blue}{\left({\left(\sqrt{2}\right)}^{2} \cdot \sqrt{re}\right)} \]
            2. unpow2N/A

              \[\leadsto \frac{1}{2} \cdot \left(\color{blue}{\left(\sqrt{2} \cdot \sqrt{2}\right)} \cdot \sqrt{re}\right) \]
            3. rem-square-sqrtN/A

              \[\leadsto \frac{1}{2} \cdot \left(\color{blue}{2} \cdot \sqrt{re}\right) \]
            4. associate-*r*N/A

              \[\leadsto \color{blue}{\left(\frac{1}{2} \cdot 2\right) \cdot \sqrt{re}} \]
            5. metadata-evalN/A

              \[\leadsto \color{blue}{1} \cdot \sqrt{re} \]
            6. *-lft-identityN/A

              \[\leadsto \color{blue}{\sqrt{re}} \]
            7. lower-sqrt.f6491.5

              \[\leadsto \color{blue}{\sqrt{re}} \]
          5. Applied rewrites91.5%

            \[\leadsto \color{blue}{\sqrt{re}} \]
        7. Recombined 4 regimes into one program.
        8. Final simplification56.5%

          \[\leadsto \begin{array}{l} \mathbf{if}\;re \leq -3.7 \cdot 10^{+118}:\\ \;\;\;\;\sqrt{\frac{-im}{\frac{re}{im}}} \cdot 0.5\\ \mathbf{elif}\;re \leq 9 \cdot 10^{-147}:\\ \;\;\;\;\sqrt{\mathsf{fma}\left(\frac{re}{im} + 2, re, im \cdot 2\right)} \cdot 0.5\\ \mathbf{elif}\;re \leq 2.4 \cdot 10^{+148}:\\ \;\;\;\;\sqrt{\left(\sqrt{im \cdot im + re \cdot re} + re\right) \cdot 2} \cdot 0.5\\ \mathbf{else}:\\ \;\;\;\;\sqrt{re}\\ \end{array} \]
        9. Add Preprocessing

        Alternative 4: 49.6% accurate, 1.0× speedup?

        \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;re \leq -6.2 \cdot 10^{+53}:\\ \;\;\;\;\sqrt{\frac{-im}{\frac{re}{im}}} \cdot 0.5\\ \mathbf{elif}\;re \leq 1.4 \cdot 10^{+111}:\\ \;\;\;\;\sqrt{\left(im + re\right) \cdot 2} \cdot 0.5\\ \mathbf{else}:\\ \;\;\;\;\sqrt{re}\\ \end{array} \end{array} \]
        (FPCore (re im)
         :precision binary64
         (if (<= re -6.2e+53)
           (* (sqrt (/ (- im) (/ re im))) 0.5)
           (if (<= re 1.4e+111) (* (sqrt (* (+ im re) 2.0)) 0.5) (sqrt re))))
        double code(double re, double im) {
        	double tmp;
        	if (re <= -6.2e+53) {
        		tmp = sqrt((-im / (re / im))) * 0.5;
        	} else if (re <= 1.4e+111) {
        		tmp = sqrt(((im + re) * 2.0)) * 0.5;
        	} else {
        		tmp = sqrt(re);
        	}
        	return tmp;
        }
        
        real(8) function code(re, im)
            real(8), intent (in) :: re
            real(8), intent (in) :: im
            real(8) :: tmp
            if (re <= (-6.2d+53)) then
                tmp = sqrt((-im / (re / im))) * 0.5d0
            else if (re <= 1.4d+111) then
                tmp = sqrt(((im + re) * 2.0d0)) * 0.5d0
            else
                tmp = sqrt(re)
            end if
            code = tmp
        end function
        
        public static double code(double re, double im) {
        	double tmp;
        	if (re <= -6.2e+53) {
        		tmp = Math.sqrt((-im / (re / im))) * 0.5;
        	} else if (re <= 1.4e+111) {
        		tmp = Math.sqrt(((im + re) * 2.0)) * 0.5;
        	} else {
        		tmp = Math.sqrt(re);
        	}
        	return tmp;
        }
        
        def code(re, im):
        	tmp = 0
        	if re <= -6.2e+53:
        		tmp = math.sqrt((-im / (re / im))) * 0.5
        	elif re <= 1.4e+111:
        		tmp = math.sqrt(((im + re) * 2.0)) * 0.5
        	else:
        		tmp = math.sqrt(re)
        	return tmp
        
        function code(re, im)
        	tmp = 0.0
        	if (re <= -6.2e+53)
        		tmp = Float64(sqrt(Float64(Float64(-im) / Float64(re / im))) * 0.5);
        	elseif (re <= 1.4e+111)
        		tmp = Float64(sqrt(Float64(Float64(im + re) * 2.0)) * 0.5);
        	else
        		tmp = sqrt(re);
        	end
        	return tmp
        end
        
        function tmp_2 = code(re, im)
        	tmp = 0.0;
        	if (re <= -6.2e+53)
        		tmp = sqrt((-im / (re / im))) * 0.5;
        	elseif (re <= 1.4e+111)
        		tmp = sqrt(((im + re) * 2.0)) * 0.5;
        	else
        		tmp = sqrt(re);
        	end
        	tmp_2 = tmp;
        end
        
        code[re_, im_] := If[LessEqual[re, -6.2e+53], N[(N[Sqrt[N[((-im) / N[(re / im), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] * 0.5), $MachinePrecision], If[LessEqual[re, 1.4e+111], N[(N[Sqrt[N[(N[(im + re), $MachinePrecision] * 2.0), $MachinePrecision]], $MachinePrecision] * 0.5), $MachinePrecision], N[Sqrt[re], $MachinePrecision]]]
        
        \begin{array}{l}
        
        \\
        \begin{array}{l}
        \mathbf{if}\;re \leq -6.2 \cdot 10^{+53}:\\
        \;\;\;\;\sqrt{\frac{-im}{\frac{re}{im}}} \cdot 0.5\\
        
        \mathbf{elif}\;re \leq 1.4 \cdot 10^{+111}:\\
        \;\;\;\;\sqrt{\left(im + re\right) \cdot 2} \cdot 0.5\\
        
        \mathbf{else}:\\
        \;\;\;\;\sqrt{re}\\
        
        
        \end{array}
        \end{array}
        
        Derivation
        1. Split input into 3 regimes
        2. if re < -6.20000000000000038e53

          1. Initial program 9.2%

            \[0.5 \cdot \sqrt{2 \cdot \left(\sqrt{re \cdot re + im \cdot im} + re\right)} \]
          2. Add Preprocessing
          3. Taylor expanded in re around -inf

            \[\leadsto \frac{1}{2} \cdot \sqrt{\color{blue}{-1 \cdot \frac{{im}^{2}}{re}}} \]
          4. Step-by-step derivation
            1. mul-1-negN/A

              \[\leadsto \frac{1}{2} \cdot \sqrt{\color{blue}{\mathsf{neg}\left(\frac{{im}^{2}}{re}\right)}} \]
            2. unpow2N/A

              \[\leadsto \frac{1}{2} \cdot \sqrt{\mathsf{neg}\left(\frac{\color{blue}{im \cdot im}}{re}\right)} \]
            3. associate-/l*N/A

              \[\leadsto \frac{1}{2} \cdot \sqrt{\mathsf{neg}\left(\color{blue}{im \cdot \frac{im}{re}}\right)} \]
            4. distribute-lft-neg-inN/A

              \[\leadsto \frac{1}{2} \cdot \sqrt{\color{blue}{\left(\mathsf{neg}\left(im\right)\right) \cdot \frac{im}{re}}} \]
            5. mul-1-negN/A

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

              \[\leadsto \frac{1}{2} \cdot \sqrt{\color{blue}{\left(-1 \cdot im\right) \cdot \frac{im}{re}}} \]
            7. mul-1-negN/A

              \[\leadsto \frac{1}{2} \cdot \sqrt{\color{blue}{\left(\mathsf{neg}\left(im\right)\right)} \cdot \frac{im}{re}} \]
            8. lower-neg.f64N/A

              \[\leadsto \frac{1}{2} \cdot \sqrt{\color{blue}{\left(-im\right)} \cdot \frac{im}{re}} \]
            9. lower-/.f6458.1

              \[\leadsto 0.5 \cdot \sqrt{\left(-im\right) \cdot \color{blue}{\frac{im}{re}}} \]
          5. Applied rewrites58.1%

            \[\leadsto 0.5 \cdot \sqrt{\color{blue}{\left(-im\right) \cdot \frac{im}{re}}} \]
          6. Step-by-step derivation
            1. Applied rewrites58.2%

              \[\leadsto 0.5 \cdot \sqrt{\frac{-im}{\color{blue}{\frac{re}{im}}}} \]

            if -6.20000000000000038e53 < re < 1.4e111

            1. Initial program 58.0%

              \[0.5 \cdot \sqrt{2 \cdot \left(\sqrt{re \cdot re + im \cdot im} + re\right)} \]
            2. Add Preprocessing
            3. Taylor expanded in re around 0

              \[\leadsto \frac{1}{2} \cdot \sqrt{2 \cdot \color{blue}{\left(im + re\right)}} \]
            4. Step-by-step derivation
              1. +-commutativeN/A

                \[\leadsto \frac{1}{2} \cdot \sqrt{2 \cdot \color{blue}{\left(re + im\right)}} \]
              2. lower-+.f6436.6

                \[\leadsto 0.5 \cdot \sqrt{2 \cdot \color{blue}{\left(re + im\right)}} \]
            5. Applied rewrites36.6%

              \[\leadsto 0.5 \cdot \sqrt{2 \cdot \color{blue}{\left(re + im\right)}} \]

            if 1.4e111 < re

            1. Initial program 21.6%

              \[0.5 \cdot \sqrt{2 \cdot \left(\sqrt{re \cdot re + im \cdot im} + re\right)} \]
            2. Add Preprocessing
            3. Taylor expanded in re around inf

              \[\leadsto \color{blue}{\frac{1}{2} \cdot \left(\sqrt{re} \cdot {\left(\sqrt{2}\right)}^{2}\right)} \]
            4. Step-by-step derivation
              1. *-commutativeN/A

                \[\leadsto \frac{1}{2} \cdot \color{blue}{\left({\left(\sqrt{2}\right)}^{2} \cdot \sqrt{re}\right)} \]
              2. unpow2N/A

                \[\leadsto \frac{1}{2} \cdot \left(\color{blue}{\left(\sqrt{2} \cdot \sqrt{2}\right)} \cdot \sqrt{re}\right) \]
              3. rem-square-sqrtN/A

                \[\leadsto \frac{1}{2} \cdot \left(\color{blue}{2} \cdot \sqrt{re}\right) \]
              4. associate-*r*N/A

                \[\leadsto \color{blue}{\left(\frac{1}{2} \cdot 2\right) \cdot \sqrt{re}} \]
              5. metadata-evalN/A

                \[\leadsto \color{blue}{1} \cdot \sqrt{re} \]
              6. *-lft-identityN/A

                \[\leadsto \color{blue}{\sqrt{re}} \]
              7. lower-sqrt.f6489.1

                \[\leadsto \color{blue}{\sqrt{re}} \]
            5. Applied rewrites89.1%

              \[\leadsto \color{blue}{\sqrt{re}} \]
          7. Recombined 3 regimes into one program.
          8. Final simplification50.5%

            \[\leadsto \begin{array}{l} \mathbf{if}\;re \leq -6.2 \cdot 10^{+53}:\\ \;\;\;\;\sqrt{\frac{-im}{\frac{re}{im}}} \cdot 0.5\\ \mathbf{elif}\;re \leq 1.4 \cdot 10^{+111}:\\ \;\;\;\;\sqrt{\left(im + re\right) \cdot 2} \cdot 0.5\\ \mathbf{else}:\\ \;\;\;\;\sqrt{re}\\ \end{array} \]
          9. Add Preprocessing

          Alternative 5: 49.6% accurate, 1.2× speedup?

          \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;re \leq -6.2 \cdot 10^{+53}:\\ \;\;\;\;\sqrt{\frac{-im}{re} \cdot im} \cdot 0.5\\ \mathbf{elif}\;re \leq 1.4 \cdot 10^{+111}:\\ \;\;\;\;\sqrt{\left(im + re\right) \cdot 2} \cdot 0.5\\ \mathbf{else}:\\ \;\;\;\;\sqrt{re}\\ \end{array} \end{array} \]
          (FPCore (re im)
           :precision binary64
           (if (<= re -6.2e+53)
             (* (sqrt (* (/ (- im) re) im)) 0.5)
             (if (<= re 1.4e+111) (* (sqrt (* (+ im re) 2.0)) 0.5) (sqrt re))))
          double code(double re, double im) {
          	double tmp;
          	if (re <= -6.2e+53) {
          		tmp = sqrt(((-im / re) * im)) * 0.5;
          	} else if (re <= 1.4e+111) {
          		tmp = sqrt(((im + re) * 2.0)) * 0.5;
          	} else {
          		tmp = sqrt(re);
          	}
          	return tmp;
          }
          
          real(8) function code(re, im)
              real(8), intent (in) :: re
              real(8), intent (in) :: im
              real(8) :: tmp
              if (re <= (-6.2d+53)) then
                  tmp = sqrt(((-im / re) * im)) * 0.5d0
              else if (re <= 1.4d+111) then
                  tmp = sqrt(((im + re) * 2.0d0)) * 0.5d0
              else
                  tmp = sqrt(re)
              end if
              code = tmp
          end function
          
          public static double code(double re, double im) {
          	double tmp;
          	if (re <= -6.2e+53) {
          		tmp = Math.sqrt(((-im / re) * im)) * 0.5;
          	} else if (re <= 1.4e+111) {
          		tmp = Math.sqrt(((im + re) * 2.0)) * 0.5;
          	} else {
          		tmp = Math.sqrt(re);
          	}
          	return tmp;
          }
          
          def code(re, im):
          	tmp = 0
          	if re <= -6.2e+53:
          		tmp = math.sqrt(((-im / re) * im)) * 0.5
          	elif re <= 1.4e+111:
          		tmp = math.sqrt(((im + re) * 2.0)) * 0.5
          	else:
          		tmp = math.sqrt(re)
          	return tmp
          
          function code(re, im)
          	tmp = 0.0
          	if (re <= -6.2e+53)
          		tmp = Float64(sqrt(Float64(Float64(Float64(-im) / re) * im)) * 0.5);
          	elseif (re <= 1.4e+111)
          		tmp = Float64(sqrt(Float64(Float64(im + re) * 2.0)) * 0.5);
          	else
          		tmp = sqrt(re);
          	end
          	return tmp
          end
          
          function tmp_2 = code(re, im)
          	tmp = 0.0;
          	if (re <= -6.2e+53)
          		tmp = sqrt(((-im / re) * im)) * 0.5;
          	elseif (re <= 1.4e+111)
          		tmp = sqrt(((im + re) * 2.0)) * 0.5;
          	else
          		tmp = sqrt(re);
          	end
          	tmp_2 = tmp;
          end
          
          code[re_, im_] := If[LessEqual[re, -6.2e+53], N[(N[Sqrt[N[(N[((-im) / re), $MachinePrecision] * im), $MachinePrecision]], $MachinePrecision] * 0.5), $MachinePrecision], If[LessEqual[re, 1.4e+111], N[(N[Sqrt[N[(N[(im + re), $MachinePrecision] * 2.0), $MachinePrecision]], $MachinePrecision] * 0.5), $MachinePrecision], N[Sqrt[re], $MachinePrecision]]]
          
          \begin{array}{l}
          
          \\
          \begin{array}{l}
          \mathbf{if}\;re \leq -6.2 \cdot 10^{+53}:\\
          \;\;\;\;\sqrt{\frac{-im}{re} \cdot im} \cdot 0.5\\
          
          \mathbf{elif}\;re \leq 1.4 \cdot 10^{+111}:\\
          \;\;\;\;\sqrt{\left(im + re\right) \cdot 2} \cdot 0.5\\
          
          \mathbf{else}:\\
          \;\;\;\;\sqrt{re}\\
          
          
          \end{array}
          \end{array}
          
          Derivation
          1. Split input into 3 regimes
          2. if re < -6.20000000000000038e53

            1. Initial program 9.2%

              \[0.5 \cdot \sqrt{2 \cdot \left(\sqrt{re \cdot re + im \cdot im} + re\right)} \]
            2. Add Preprocessing
            3. Taylor expanded in re around -inf

              \[\leadsto \frac{1}{2} \cdot \sqrt{\color{blue}{-1 \cdot \frac{{im}^{2}}{re}}} \]
            4. Step-by-step derivation
              1. mul-1-negN/A

                \[\leadsto \frac{1}{2} \cdot \sqrt{\color{blue}{\mathsf{neg}\left(\frac{{im}^{2}}{re}\right)}} \]
              2. unpow2N/A

                \[\leadsto \frac{1}{2} \cdot \sqrt{\mathsf{neg}\left(\frac{\color{blue}{im \cdot im}}{re}\right)} \]
              3. associate-/l*N/A

                \[\leadsto \frac{1}{2} \cdot \sqrt{\mathsf{neg}\left(\color{blue}{im \cdot \frac{im}{re}}\right)} \]
              4. distribute-lft-neg-inN/A

                \[\leadsto \frac{1}{2} \cdot \sqrt{\color{blue}{\left(\mathsf{neg}\left(im\right)\right) \cdot \frac{im}{re}}} \]
              5. mul-1-negN/A

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

                \[\leadsto \frac{1}{2} \cdot \sqrt{\color{blue}{\left(-1 \cdot im\right) \cdot \frac{im}{re}}} \]
              7. mul-1-negN/A

                \[\leadsto \frac{1}{2} \cdot \sqrt{\color{blue}{\left(\mathsf{neg}\left(im\right)\right)} \cdot \frac{im}{re}} \]
              8. lower-neg.f64N/A

                \[\leadsto \frac{1}{2} \cdot \sqrt{\color{blue}{\left(-im\right)} \cdot \frac{im}{re}} \]
              9. lower-/.f6458.1

                \[\leadsto 0.5 \cdot \sqrt{\left(-im\right) \cdot \color{blue}{\frac{im}{re}}} \]
            5. Applied rewrites58.1%

              \[\leadsto 0.5 \cdot \sqrt{\color{blue}{\left(-im\right) \cdot \frac{im}{re}}} \]

            if -6.20000000000000038e53 < re < 1.4e111

            1. Initial program 58.0%

              \[0.5 \cdot \sqrt{2 \cdot \left(\sqrt{re \cdot re + im \cdot im} + re\right)} \]
            2. Add Preprocessing
            3. Taylor expanded in re around 0

              \[\leadsto \frac{1}{2} \cdot \sqrt{2 \cdot \color{blue}{\left(im + re\right)}} \]
            4. Step-by-step derivation
              1. +-commutativeN/A

                \[\leadsto \frac{1}{2} \cdot \sqrt{2 \cdot \color{blue}{\left(re + im\right)}} \]
              2. lower-+.f6436.6

                \[\leadsto 0.5 \cdot \sqrt{2 \cdot \color{blue}{\left(re + im\right)}} \]
            5. Applied rewrites36.6%

              \[\leadsto 0.5 \cdot \sqrt{2 \cdot \color{blue}{\left(re + im\right)}} \]

            if 1.4e111 < re

            1. Initial program 21.6%

              \[0.5 \cdot \sqrt{2 \cdot \left(\sqrt{re \cdot re + im \cdot im} + re\right)} \]
            2. Add Preprocessing
            3. Taylor expanded in re around inf

              \[\leadsto \color{blue}{\frac{1}{2} \cdot \left(\sqrt{re} \cdot {\left(\sqrt{2}\right)}^{2}\right)} \]
            4. Step-by-step derivation
              1. *-commutativeN/A

                \[\leadsto \frac{1}{2} \cdot \color{blue}{\left({\left(\sqrt{2}\right)}^{2} \cdot \sqrt{re}\right)} \]
              2. unpow2N/A

                \[\leadsto \frac{1}{2} \cdot \left(\color{blue}{\left(\sqrt{2} \cdot \sqrt{2}\right)} \cdot \sqrt{re}\right) \]
              3. rem-square-sqrtN/A

                \[\leadsto \frac{1}{2} \cdot \left(\color{blue}{2} \cdot \sqrt{re}\right) \]
              4. associate-*r*N/A

                \[\leadsto \color{blue}{\left(\frac{1}{2} \cdot 2\right) \cdot \sqrt{re}} \]
              5. metadata-evalN/A

                \[\leadsto \color{blue}{1} \cdot \sqrt{re} \]
              6. *-lft-identityN/A

                \[\leadsto \color{blue}{\sqrt{re}} \]
              7. lower-sqrt.f6489.1

                \[\leadsto \color{blue}{\sqrt{re}} \]
            5. Applied rewrites89.1%

              \[\leadsto \color{blue}{\sqrt{re}} \]
          3. Recombined 3 regimes into one program.
          4. Final simplification50.5%

            \[\leadsto \begin{array}{l} \mathbf{if}\;re \leq -6.2 \cdot 10^{+53}:\\ \;\;\;\;\sqrt{\frac{-im}{re} \cdot im} \cdot 0.5\\ \mathbf{elif}\;re \leq 1.4 \cdot 10^{+111}:\\ \;\;\;\;\sqrt{\left(im + re\right) \cdot 2} \cdot 0.5\\ \mathbf{else}:\\ \;\;\;\;\sqrt{re}\\ \end{array} \]
          5. Add Preprocessing

          Alternative 6: 41.1% accurate, 1.3× speedup?

          \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;re \leq -4 \cdot 10^{+165}:\\ \;\;\;\;\sqrt{\left(\left(-re\right) + re\right) \cdot 2} \cdot 0.5\\ \mathbf{elif}\;re \leq 1.4 \cdot 10^{+111}:\\ \;\;\;\;\sqrt{\left(im + re\right) \cdot 2} \cdot 0.5\\ \mathbf{else}:\\ \;\;\;\;\sqrt{re}\\ \end{array} \end{array} \]
          (FPCore (re im)
           :precision binary64
           (if (<= re -4e+165)
             (* (sqrt (* (+ (- re) re) 2.0)) 0.5)
             (if (<= re 1.4e+111) (* (sqrt (* (+ im re) 2.0)) 0.5) (sqrt re))))
          double code(double re, double im) {
          	double tmp;
          	if (re <= -4e+165) {
          		tmp = sqrt(((-re + re) * 2.0)) * 0.5;
          	} else if (re <= 1.4e+111) {
          		tmp = sqrt(((im + re) * 2.0)) * 0.5;
          	} else {
          		tmp = sqrt(re);
          	}
          	return tmp;
          }
          
          real(8) function code(re, im)
              real(8), intent (in) :: re
              real(8), intent (in) :: im
              real(8) :: tmp
              if (re <= (-4d+165)) then
                  tmp = sqrt(((-re + re) * 2.0d0)) * 0.5d0
              else if (re <= 1.4d+111) then
                  tmp = sqrt(((im + re) * 2.0d0)) * 0.5d0
              else
                  tmp = sqrt(re)
              end if
              code = tmp
          end function
          
          public static double code(double re, double im) {
          	double tmp;
          	if (re <= -4e+165) {
          		tmp = Math.sqrt(((-re + re) * 2.0)) * 0.5;
          	} else if (re <= 1.4e+111) {
          		tmp = Math.sqrt(((im + re) * 2.0)) * 0.5;
          	} else {
          		tmp = Math.sqrt(re);
          	}
          	return tmp;
          }
          
          def code(re, im):
          	tmp = 0
          	if re <= -4e+165:
          		tmp = math.sqrt(((-re + re) * 2.0)) * 0.5
          	elif re <= 1.4e+111:
          		tmp = math.sqrt(((im + re) * 2.0)) * 0.5
          	else:
          		tmp = math.sqrt(re)
          	return tmp
          
          function code(re, im)
          	tmp = 0.0
          	if (re <= -4e+165)
          		tmp = Float64(sqrt(Float64(Float64(Float64(-re) + re) * 2.0)) * 0.5);
          	elseif (re <= 1.4e+111)
          		tmp = Float64(sqrt(Float64(Float64(im + re) * 2.0)) * 0.5);
          	else
          		tmp = sqrt(re);
          	end
          	return tmp
          end
          
          function tmp_2 = code(re, im)
          	tmp = 0.0;
          	if (re <= -4e+165)
          		tmp = sqrt(((-re + re) * 2.0)) * 0.5;
          	elseif (re <= 1.4e+111)
          		tmp = sqrt(((im + re) * 2.0)) * 0.5;
          	else
          		tmp = sqrt(re);
          	end
          	tmp_2 = tmp;
          end
          
          code[re_, im_] := If[LessEqual[re, -4e+165], N[(N[Sqrt[N[(N[((-re) + re), $MachinePrecision] * 2.0), $MachinePrecision]], $MachinePrecision] * 0.5), $MachinePrecision], If[LessEqual[re, 1.4e+111], N[(N[Sqrt[N[(N[(im + re), $MachinePrecision] * 2.0), $MachinePrecision]], $MachinePrecision] * 0.5), $MachinePrecision], N[Sqrt[re], $MachinePrecision]]]
          
          \begin{array}{l}
          
          \\
          \begin{array}{l}
          \mathbf{if}\;re \leq -4 \cdot 10^{+165}:\\
          \;\;\;\;\sqrt{\left(\left(-re\right) + re\right) \cdot 2} \cdot 0.5\\
          
          \mathbf{elif}\;re \leq 1.4 \cdot 10^{+111}:\\
          \;\;\;\;\sqrt{\left(im + re\right) \cdot 2} \cdot 0.5\\
          
          \mathbf{else}:\\
          \;\;\;\;\sqrt{re}\\
          
          
          \end{array}
          \end{array}
          
          Derivation
          1. Split input into 3 regimes
          2. if re < -3.9999999999999996e165

            1. Initial program 2.8%

              \[0.5 \cdot \sqrt{2 \cdot \left(\sqrt{re \cdot re + im \cdot im} + re\right)} \]
            2. Add Preprocessing
            3. Taylor expanded in re around -inf

              \[\leadsto \frac{1}{2} \cdot \sqrt{2 \cdot \left(\color{blue}{-1 \cdot re} + re\right)} \]
            4. Step-by-step derivation
              1. mul-1-negN/A

                \[\leadsto \frac{1}{2} \cdot \sqrt{2 \cdot \left(\color{blue}{\left(\mathsf{neg}\left(re\right)\right)} + re\right)} \]
              2. lower-neg.f6424.4

                \[\leadsto 0.5 \cdot \sqrt{2 \cdot \left(\color{blue}{\left(-re\right)} + re\right)} \]
            5. Applied rewrites24.4%

              \[\leadsto 0.5 \cdot \sqrt{2 \cdot \left(\color{blue}{\left(-re\right)} + re\right)} \]

            if -3.9999999999999996e165 < re < 1.4e111

            1. Initial program 52.1%

              \[0.5 \cdot \sqrt{2 \cdot \left(\sqrt{re \cdot re + im \cdot im} + re\right)} \]
            2. Add Preprocessing
            3. Taylor expanded in re around 0

              \[\leadsto \frac{1}{2} \cdot \sqrt{2 \cdot \color{blue}{\left(im + re\right)}} \]
            4. Step-by-step derivation
              1. +-commutativeN/A

                \[\leadsto \frac{1}{2} \cdot \sqrt{2 \cdot \color{blue}{\left(re + im\right)}} \]
              2. lower-+.f6434.1

                \[\leadsto 0.5 \cdot \sqrt{2 \cdot \color{blue}{\left(re + im\right)}} \]
            5. Applied rewrites34.1%

              \[\leadsto 0.5 \cdot \sqrt{2 \cdot \color{blue}{\left(re + im\right)}} \]

            if 1.4e111 < re

            1. Initial program 21.6%

              \[0.5 \cdot \sqrt{2 \cdot \left(\sqrt{re \cdot re + im \cdot im} + re\right)} \]
            2. Add Preprocessing
            3. Taylor expanded in re around inf

              \[\leadsto \color{blue}{\frac{1}{2} \cdot \left(\sqrt{re} \cdot {\left(\sqrt{2}\right)}^{2}\right)} \]
            4. Step-by-step derivation
              1. *-commutativeN/A

                \[\leadsto \frac{1}{2} \cdot \color{blue}{\left({\left(\sqrt{2}\right)}^{2} \cdot \sqrt{re}\right)} \]
              2. unpow2N/A

                \[\leadsto \frac{1}{2} \cdot \left(\color{blue}{\left(\sqrt{2} \cdot \sqrt{2}\right)} \cdot \sqrt{re}\right) \]
              3. rem-square-sqrtN/A

                \[\leadsto \frac{1}{2} \cdot \left(\color{blue}{2} \cdot \sqrt{re}\right) \]
              4. associate-*r*N/A

                \[\leadsto \color{blue}{\left(\frac{1}{2} \cdot 2\right) \cdot \sqrt{re}} \]
              5. metadata-evalN/A

                \[\leadsto \color{blue}{1} \cdot \sqrt{re} \]
              6. *-lft-identityN/A

                \[\leadsto \color{blue}{\sqrt{re}} \]
              7. lower-sqrt.f6489.1

                \[\leadsto \color{blue}{\sqrt{re}} \]
            5. Applied rewrites89.1%

              \[\leadsto \color{blue}{\sqrt{re}} \]
          3. Recombined 3 regimes into one program.
          4. Final simplification42.3%

            \[\leadsto \begin{array}{l} \mathbf{if}\;re \leq -4 \cdot 10^{+165}:\\ \;\;\;\;\sqrt{\left(\left(-re\right) + re\right) \cdot 2} \cdot 0.5\\ \mathbf{elif}\;re \leq 1.4 \cdot 10^{+111}:\\ \;\;\;\;\sqrt{\left(im + re\right) \cdot 2} \cdot 0.5\\ \mathbf{else}:\\ \;\;\;\;\sqrt{re}\\ \end{array} \]
          5. Add Preprocessing

          Alternative 7: 42.9% accurate, 1.7× speedup?

          \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;re \leq 3.45 \cdot 10^{-146}:\\ \;\;\;\;\sqrt{im \cdot 2} \cdot 0.5\\ \mathbf{else}:\\ \;\;\;\;\sqrt{re}\\ \end{array} \end{array} \]
          (FPCore (re im)
           :precision binary64
           (if (<= re 3.45e-146) (* (sqrt (* im 2.0)) 0.5) (sqrt re)))
          double code(double re, double im) {
          	double tmp;
          	if (re <= 3.45e-146) {
          		tmp = sqrt((im * 2.0)) * 0.5;
          	} else {
          		tmp = sqrt(re);
          	}
          	return tmp;
          }
          
          real(8) function code(re, im)
              real(8), intent (in) :: re
              real(8), intent (in) :: im
              real(8) :: tmp
              if (re <= 3.45d-146) then
                  tmp = sqrt((im * 2.0d0)) * 0.5d0
              else
                  tmp = sqrt(re)
              end if
              code = tmp
          end function
          
          public static double code(double re, double im) {
          	double tmp;
          	if (re <= 3.45e-146) {
          		tmp = Math.sqrt((im * 2.0)) * 0.5;
          	} else {
          		tmp = Math.sqrt(re);
          	}
          	return tmp;
          }
          
          def code(re, im):
          	tmp = 0
          	if re <= 3.45e-146:
          		tmp = math.sqrt((im * 2.0)) * 0.5
          	else:
          		tmp = math.sqrt(re)
          	return tmp
          
          function code(re, im)
          	tmp = 0.0
          	if (re <= 3.45e-146)
          		tmp = Float64(sqrt(Float64(im * 2.0)) * 0.5);
          	else
          		tmp = sqrt(re);
          	end
          	return tmp
          end
          
          function tmp_2 = code(re, im)
          	tmp = 0.0;
          	if (re <= 3.45e-146)
          		tmp = sqrt((im * 2.0)) * 0.5;
          	else
          		tmp = sqrt(re);
          	end
          	tmp_2 = tmp;
          end
          
          code[re_, im_] := If[LessEqual[re, 3.45e-146], N[(N[Sqrt[N[(im * 2.0), $MachinePrecision]], $MachinePrecision] * 0.5), $MachinePrecision], N[Sqrt[re], $MachinePrecision]]
          
          \begin{array}{l}
          
          \\
          \begin{array}{l}
          \mathbf{if}\;re \leq 3.45 \cdot 10^{-146}:\\
          \;\;\;\;\sqrt{im \cdot 2} \cdot 0.5\\
          
          \mathbf{else}:\\
          \;\;\;\;\sqrt{re}\\
          
          
          \end{array}
          \end{array}
          
          Derivation
          1. Split input into 2 regimes
          2. if re < 3.4500000000000001e-146

            1. Initial program 35.3%

              \[0.5 \cdot \sqrt{2 \cdot \left(\sqrt{re \cdot re + im \cdot im} + re\right)} \]
            2. Add Preprocessing
            3. Taylor expanded in re around 0

              \[\leadsto \frac{1}{2} \cdot \sqrt{\color{blue}{2 \cdot im}} \]
            4. Step-by-step derivation
              1. lower-*.f6426.4

                \[\leadsto 0.5 \cdot \sqrt{\color{blue}{2 \cdot im}} \]
            5. Applied rewrites26.4%

              \[\leadsto 0.5 \cdot \sqrt{\color{blue}{2 \cdot im}} \]

            if 3.4500000000000001e-146 < re

            1. Initial program 50.5%

              \[0.5 \cdot \sqrt{2 \cdot \left(\sqrt{re \cdot re + im \cdot im} + re\right)} \]
            2. Add Preprocessing
            3. Taylor expanded in re around inf

              \[\leadsto \color{blue}{\frac{1}{2} \cdot \left(\sqrt{re} \cdot {\left(\sqrt{2}\right)}^{2}\right)} \]
            4. Step-by-step derivation
              1. *-commutativeN/A

                \[\leadsto \frac{1}{2} \cdot \color{blue}{\left({\left(\sqrt{2}\right)}^{2} \cdot \sqrt{re}\right)} \]
              2. unpow2N/A

                \[\leadsto \frac{1}{2} \cdot \left(\color{blue}{\left(\sqrt{2} \cdot \sqrt{2}\right)} \cdot \sqrt{re}\right) \]
              3. rem-square-sqrtN/A

                \[\leadsto \frac{1}{2} \cdot \left(\color{blue}{2} \cdot \sqrt{re}\right) \]
              4. associate-*r*N/A

                \[\leadsto \color{blue}{\left(\frac{1}{2} \cdot 2\right) \cdot \sqrt{re}} \]
              5. metadata-evalN/A

                \[\leadsto \color{blue}{1} \cdot \sqrt{re} \]
              6. *-lft-identityN/A

                \[\leadsto \color{blue}{\sqrt{re}} \]
              7. lower-sqrt.f6471.4

                \[\leadsto \color{blue}{\sqrt{re}} \]
            5. Applied rewrites71.4%

              \[\leadsto \color{blue}{\sqrt{re}} \]
          3. Recombined 2 regimes into one program.
          4. Final simplification42.4%

            \[\leadsto \begin{array}{l} \mathbf{if}\;re \leq 3.45 \cdot 10^{-146}:\\ \;\;\;\;\sqrt{im \cdot 2} \cdot 0.5\\ \mathbf{else}:\\ \;\;\;\;\sqrt{re}\\ \end{array} \]
          5. Add Preprocessing

          Alternative 8: 26.5% accurate, 4.3× speedup?

          \[\begin{array}{l} \\ \sqrt{re} \end{array} \]
          (FPCore (re im) :precision binary64 (sqrt re))
          double code(double re, double im) {
          	return sqrt(re);
          }
          
          real(8) function code(re, im)
              real(8), intent (in) :: re
              real(8), intent (in) :: im
              code = sqrt(re)
          end function
          
          public static double code(double re, double im) {
          	return Math.sqrt(re);
          }
          
          def code(re, im):
          	return math.sqrt(re)
          
          function code(re, im)
          	return sqrt(re)
          end
          
          function tmp = code(re, im)
          	tmp = sqrt(re);
          end
          
          code[re_, im_] := N[Sqrt[re], $MachinePrecision]
          
          \begin{array}{l}
          
          \\
          \sqrt{re}
          \end{array}
          
          Derivation
          1. Initial program 40.7%

            \[0.5 \cdot \sqrt{2 \cdot \left(\sqrt{re \cdot re + im \cdot im} + re\right)} \]
          2. Add Preprocessing
          3. Taylor expanded in re around inf

            \[\leadsto \color{blue}{\frac{1}{2} \cdot \left(\sqrt{re} \cdot {\left(\sqrt{2}\right)}^{2}\right)} \]
          4. Step-by-step derivation
            1. *-commutativeN/A

              \[\leadsto \frac{1}{2} \cdot \color{blue}{\left({\left(\sqrt{2}\right)}^{2} \cdot \sqrt{re}\right)} \]
            2. unpow2N/A

              \[\leadsto \frac{1}{2} \cdot \left(\color{blue}{\left(\sqrt{2} \cdot \sqrt{2}\right)} \cdot \sqrt{re}\right) \]
            3. rem-square-sqrtN/A

              \[\leadsto \frac{1}{2} \cdot \left(\color{blue}{2} \cdot \sqrt{re}\right) \]
            4. associate-*r*N/A

              \[\leadsto \color{blue}{\left(\frac{1}{2} \cdot 2\right) \cdot \sqrt{re}} \]
            5. metadata-evalN/A

              \[\leadsto \color{blue}{1} \cdot \sqrt{re} \]
            6. *-lft-identityN/A

              \[\leadsto \color{blue}{\sqrt{re}} \]
            7. lower-sqrt.f6429.1

              \[\leadsto \color{blue}{\sqrt{re}} \]
          5. Applied rewrites29.1%

            \[\leadsto \color{blue}{\sqrt{re}} \]
          6. Add Preprocessing

          Developer Target 1: 48.7% accurate, 0.6× speedup?

          \[\begin{array}{l} \\ \begin{array}{l} t_0 := \sqrt{re \cdot re + im \cdot im}\\ \mathbf{if}\;re < 0:\\ \;\;\;\;0.5 \cdot \left(\sqrt{2} \cdot \sqrt{\frac{im \cdot im}{t\_0 - re}}\right)\\ \mathbf{else}:\\ \;\;\;\;0.5 \cdot \sqrt{2 \cdot \left(t\_0 + re\right)}\\ \end{array} \end{array} \]
          (FPCore (re im)
           :precision binary64
           (let* ((t_0 (sqrt (+ (* re re) (* im im)))))
             (if (< re 0.0)
               (* 0.5 (* (sqrt 2.0) (sqrt (/ (* im im) (- t_0 re)))))
               (* 0.5 (sqrt (* 2.0 (+ t_0 re)))))))
          double code(double re, double im) {
          	double t_0 = sqrt(((re * re) + (im * im)));
          	double tmp;
          	if (re < 0.0) {
          		tmp = 0.5 * (sqrt(2.0) * sqrt(((im * im) / (t_0 - re))));
          	} else {
          		tmp = 0.5 * sqrt((2.0 * (t_0 + re)));
          	}
          	return tmp;
          }
          
          real(8) function code(re, im)
              real(8), intent (in) :: re
              real(8), intent (in) :: im
              real(8) :: t_0
              real(8) :: tmp
              t_0 = sqrt(((re * re) + (im * im)))
              if (re < 0.0d0) then
                  tmp = 0.5d0 * (sqrt(2.0d0) * sqrt(((im * im) / (t_0 - re))))
              else
                  tmp = 0.5d0 * sqrt((2.0d0 * (t_0 + re)))
              end if
              code = tmp
          end function
          
          public static double code(double re, double im) {
          	double t_0 = Math.sqrt(((re * re) + (im * im)));
          	double tmp;
          	if (re < 0.0) {
          		tmp = 0.5 * (Math.sqrt(2.0) * Math.sqrt(((im * im) / (t_0 - re))));
          	} else {
          		tmp = 0.5 * Math.sqrt((2.0 * (t_0 + re)));
          	}
          	return tmp;
          }
          
          def code(re, im):
          	t_0 = math.sqrt(((re * re) + (im * im)))
          	tmp = 0
          	if re < 0.0:
          		tmp = 0.5 * (math.sqrt(2.0) * math.sqrt(((im * im) / (t_0 - re))))
          	else:
          		tmp = 0.5 * math.sqrt((2.0 * (t_0 + re)))
          	return tmp
          
          function code(re, im)
          	t_0 = sqrt(Float64(Float64(re * re) + Float64(im * im)))
          	tmp = 0.0
          	if (re < 0.0)
          		tmp = Float64(0.5 * Float64(sqrt(2.0) * sqrt(Float64(Float64(im * im) / Float64(t_0 - re)))));
          	else
          		tmp = Float64(0.5 * sqrt(Float64(2.0 * Float64(t_0 + re))));
          	end
          	return tmp
          end
          
          function tmp_2 = code(re, im)
          	t_0 = sqrt(((re * re) + (im * im)));
          	tmp = 0.0;
          	if (re < 0.0)
          		tmp = 0.5 * (sqrt(2.0) * sqrt(((im * im) / (t_0 - re))));
          	else
          		tmp = 0.5 * sqrt((2.0 * (t_0 + re)));
          	end
          	tmp_2 = tmp;
          end
          
          code[re_, im_] := Block[{t$95$0 = N[Sqrt[N[(N[(re * re), $MachinePrecision] + N[(im * im), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]}, If[Less[re, 0.0], N[(0.5 * N[(N[Sqrt[2.0], $MachinePrecision] * N[Sqrt[N[(N[(im * im), $MachinePrecision] / N[(t$95$0 - re), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(0.5 * N[Sqrt[N[(2.0 * N[(t$95$0 + re), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]]]
          
          \begin{array}{l}
          
          \\
          \begin{array}{l}
          t_0 := \sqrt{re \cdot re + im \cdot im}\\
          \mathbf{if}\;re < 0:\\
          \;\;\;\;0.5 \cdot \left(\sqrt{2} \cdot \sqrt{\frac{im \cdot im}{t\_0 - re}}\right)\\
          
          \mathbf{else}:\\
          \;\;\;\;0.5 \cdot \sqrt{2 \cdot \left(t\_0 + re\right)}\\
          
          
          \end{array}
          \end{array}
          

          Reproduce

          ?
          herbie shell --seed 2024264 
          (FPCore (re im)
            :name "math.sqrt on complex, real part"
            :precision binary64
          
            :alt
            (! :herbie-platform default (if (< re 0) (* 1/2 (* (sqrt 2) (sqrt (/ (* im im) (- (modulus re im) re))))) (* 1/2 (sqrt (* 2 (+ (modulus re im) re))))))
          
            (* 0.5 (sqrt (* 2.0 (+ (sqrt (+ (* re re) (* im im))) re)))))