\[0.5 \cdot \sqrt{2.0 \cdot \left(\sqrt{re \cdot re + im \cdot im} + re\right)}\]
Test:
math.sqrt on complex, real part
Bits:
128 bits
Bits error versus re
Bits error versus im
Time: 9.2 s
Input Error: 18.6
Output Error: 9.6
Log: ⚲
Profile: 🕒
\(\begin{cases} \sqrt{{im}^2 \cdot 2.0} \cdot \frac{0.5}{\sqrt{re \cdot -2}} & \text{when } re \le -6.63865f-12 \\ 0.5 \cdot \sqrt{2.0 \cdot \left(\sqrt{re \cdot re + im \cdot im} + re\right)} & \text{when } re \le 4.3888258f+13 \\ 0.5 \cdot \sqrt{\left(2 \cdot re + \frac{im \cdot \frac{1}{2}}{\frac{re}{im}}\right) \cdot 2.0} & \text{otherwise} \end{cases}\)

    if re < -6.63865f-12

    1. Started with
      \[0.5 \cdot \sqrt{2.0 \cdot \left(\sqrt{re \cdot re + im \cdot im} + re\right)}\]
      28.0
    2. Using strategy rm
      28.0
    3. Applied flip-+ to get
      \[0.5 \cdot \sqrt{2.0 \cdot \color{red}{\left(\sqrt{re \cdot re + im \cdot im} + re\right)}} \leadsto 0.5 \cdot \sqrt{2.0 \cdot \color{blue}{\frac{{\left(\sqrt{re \cdot re + im \cdot im}\right)}^2 - {re}^2}{\sqrt{re \cdot re + im \cdot im} - re}}}\]
      28.8
    4. Applied associate-*r/ to get
      \[0.5 \cdot \sqrt{\color{red}{2.0 \cdot \frac{{\left(\sqrt{re \cdot re + im \cdot im}\right)}^2 - {re}^2}{\sqrt{re \cdot re + im \cdot im} - re}}} \leadsto 0.5 \cdot \sqrt{\color{blue}{\frac{2.0 \cdot \left({\left(\sqrt{re \cdot re + im \cdot im}\right)}^2 - {re}^2\right)}{\sqrt{re \cdot re + im \cdot im} - re}}}\]
      28.8
    5. Applied sqrt-div to get
      \[0.5 \cdot \color{red}{\sqrt{\frac{2.0 \cdot \left({\left(\sqrt{re \cdot re + im \cdot im}\right)}^2 - {re}^2\right)}{\sqrt{re \cdot re + im \cdot im} - re}}} \leadsto 0.5 \cdot \color{blue}{\frac{\sqrt{2.0 \cdot \left({\left(\sqrt{re \cdot re + im \cdot im}\right)}^2 - {re}^2\right)}}{\sqrt{\sqrt{re \cdot re + im \cdot im} - re}}}\]
      28.8
    6. Applied simplify to get
      \[0.5 \cdot \frac{\color{red}{\sqrt{2.0 \cdot \left({\left(\sqrt{re \cdot re + im \cdot im}\right)}^2 - {re}^2\right)}}}{\sqrt{\sqrt{re \cdot re + im \cdot im} - re}} \leadsto 0.5 \cdot \frac{\color{blue}{\sqrt{\left(2.0 \cdot im\right) \cdot im}}}{\sqrt{\sqrt{re \cdot re + im \cdot im} - re}}\]
      20.3
    7. Applied simplify to get
      \[0.5 \cdot \frac{\sqrt{\left(2.0 \cdot im\right) \cdot im}}{\color{red}{\sqrt{\sqrt{re \cdot re + im \cdot im} - re}}} \leadsto 0.5 \cdot \frac{\sqrt{\left(2.0 \cdot im\right) \cdot im}}{\color{blue}{\sqrt{\sqrt{{re}^2 + im \cdot im} - re}}}\]
      20.3
    8. Applied taylor to get
      \[0.5 \cdot \frac{\sqrt{\left(2.0 \cdot im\right) \cdot im}}{\sqrt{\sqrt{{re}^2 + im \cdot im} - re}} \leadsto 0.5 \cdot \frac{\sqrt{\left(2.0 \cdot im\right) \cdot im}}{\sqrt{-2 \cdot re}}\]
      11.1
    9. Taylor expanded around -inf to get
      \[0.5 \cdot \frac{\sqrt{\left(2.0 \cdot im\right) \cdot im}}{\sqrt{\color{red}{-2 \cdot re}}} \leadsto 0.5 \cdot \frac{\sqrt{\left(2.0 \cdot im\right) \cdot im}}{\sqrt{\color{blue}{-2 \cdot re}}}\]
      11.1
    10. Applied simplify to get
      \[0.5 \cdot \frac{\sqrt{\left(2.0 \cdot im\right) \cdot im}}{\sqrt{-2 \cdot re}} \leadsto \frac{\sqrt{\left(im \cdot im\right) \cdot 2.0}}{\frac{\sqrt{-2 \cdot re}}{0.5}}\]
      11.1
    11. Applied final simplification
    12. Applied simplify to get
      \[\color{red}{\frac{\sqrt{\left(im \cdot im\right) \cdot 2.0}}{\frac{\sqrt{-2 \cdot re}}{0.5}}} \leadsto \color{blue}{\sqrt{{im}^2 \cdot 2.0} \cdot \frac{0.5}{\sqrt{re \cdot -2}}}\]
      11.1

    if -6.63865f-12 < re < 4.3888258f+13

    1. Started with
      \[0.5 \cdot \sqrt{2.0 \cdot \left(\sqrt{re \cdot re + im \cdot im} + re\right)}\]
      10.7

    if 4.3888258f+13 < re

    1. Started with
      \[0.5 \cdot \sqrt{2.0 \cdot \left(\sqrt{re \cdot re + im \cdot im} + re\right)}\]
      24.8
    2. Using strategy rm
      24.8
    3. Applied add-cube-cbrt to get
      \[0.5 \cdot \sqrt{2.0 \cdot \left(\color{red}{\sqrt{re \cdot re + im \cdot im}} + re\right)} \leadsto 0.5 \cdot \sqrt{2.0 \cdot \left(\color{blue}{{\left(\sqrt[3]{\sqrt{re \cdot re + im \cdot im}}\right)}^3} + re\right)}\]
      24.8
    4. Applied simplify to get
      \[0.5 \cdot \sqrt{2.0 \cdot \left({\color{red}{\left(\sqrt[3]{\sqrt{re \cdot re + im \cdot im}}\right)}}^3 + re\right)} \leadsto 0.5 \cdot \sqrt{2.0 \cdot \left({\color{blue}{\left(\sqrt[3]{\sqrt{{re}^2 + im \cdot im}}\right)}}^3 + re\right)}\]
      24.8
    5. Applied taylor to get
      \[0.5 \cdot \sqrt{2.0 \cdot \left({\left(\sqrt[3]{\sqrt{{re}^2 + im \cdot im}}\right)}^3 + re\right)} \leadsto 0.5 \cdot \sqrt{2.0 \cdot \left(2 \cdot re + \frac{1}{2} \cdot \frac{{im}^2}{re}\right)}\]
      7.8
    6. Taylor expanded around 0 to get
      \[0.5 \cdot \sqrt{2.0 \cdot \color{red}{\left(2 \cdot re + \frac{1}{2} \cdot \frac{{im}^2}{re}\right)}} \leadsto 0.5 \cdot \sqrt{2.0 \cdot \color{blue}{\left(2 \cdot re + \frac{1}{2} \cdot \frac{{im}^2}{re}\right)}}\]
      7.8
    7. Applied simplify to get
      \[0.5 \cdot \sqrt{2.0 \cdot \left(2 \cdot re + \frac{1}{2} \cdot \frac{{im}^2}{re}\right)} \leadsto 0.5 \cdot \sqrt{\left(2 \cdot re + \frac{im \cdot \frac{1}{2}}{\frac{re}{im}}\right) \cdot 2.0}\]
      2.9
    8. Applied final simplification
  1. Removed slow pow expressions

Original test:


(lambda ((re default) (im default))
  #:name "math.sqrt on complex, real part"
  (* 0.5 (sqrt (* 2.0 (+ (sqrt (+ (* re re) (* im im))) re))))
  #:target
  (if (< re 0) (* 0.5 (* (sqrt 2) (sqrt (/ (sqr im) (- (sqrt (+ (sqr re) (sqr im))) re))))) (* 0.5 (sqrt (* 2.0 (+ (sqrt (+ (* re re) (* im im))) re))))))