Average Error: 29.9 → 18.0
Time: 27.6s
Precision: 64
Internal Precision: 320
\[\sqrt{re \cdot re + im \cdot im}\]
\[\begin{array}{l} \mathbf{if}\;re \le -3.836812280349736 \cdot 10^{+127}:\\ \;\;\;\;-re\\ \mathbf{if}\;re \le -5.6974351952720775 \cdot 10^{-213}:\\ \;\;\;\;\sqrt{re \cdot re + im \cdot im}\\ \mathbf{if}\;re \le 1.0892602907625438 \cdot 10^{-235}:\\ \;\;\;\;im\\ \mathbf{if}\;re \le 2.8288165587341483 \cdot 10^{-187}:\\ \;\;\;\;{\left(\frac{-1}{im}\right)}^{-1}\\ \mathbf{if}\;re \le 1.23303634520905 \cdot 10^{-159}:\\ \;\;\;\;im\\ \mathbf{if}\;re \le 1.2688591977550717 \cdot 10^{+154}:\\ \;\;\;\;\sqrt{re \cdot re + im \cdot im}\\ \mathbf{else}:\\ \;\;\;\;re\\ \end{array}\]

Error

Bits error versus re

Bits error versus im

Derivation

  1. Split input into 5 regimes
  2. if re < -3.836812280349736e+127

    1. Initial program 52.9

      \[\sqrt{re \cdot re + im \cdot im}\]
    2. Taylor expanded around -inf 8.8

      \[\leadsto \color{blue}{-1 \cdot re}\]
    3. Applied simplify8.8

      \[\leadsto \color{blue}{-re}\]

    if -3.836812280349736e+127 < re < -5.6974351952720775e-213 or 1.23303634520905e-159 < re < 1.2688591977550717e+154

    1. Initial program 16.6

      \[\sqrt{re \cdot re + im \cdot im}\]

    if -5.6974351952720775e-213 < re < 1.0892602907625438e-235 or 2.8288165587341483e-187 < re < 1.23303634520905e-159

    1. Initial program 28.2

      \[\sqrt{re \cdot re + im \cdot im}\]
    2. Taylor expanded around 0 34.0

      \[\leadsto \color{blue}{im}\]

    if 1.0892602907625438e-235 < re < 2.8288165587341483e-187

    1. Initial program 30.6

      \[\sqrt{re \cdot re + im \cdot im}\]
    2. Using strategy rm
    3. Applied add-cbrt-cube42.3

      \[\leadsto \color{blue}{\sqrt[3]{\left(\sqrt{re \cdot re + im \cdot im} \cdot \sqrt{re \cdot re + im \cdot im}\right) \cdot \sqrt{re \cdot re + im \cdot im}}}\]
    4. Applied simplify42.3

      \[\leadsto \sqrt[3]{\color{blue}{\left(im \cdot im + re \cdot re\right) \cdot \sqrt{im \cdot im + re \cdot re}}}\]
    5. Taylor expanded around -inf 38.0

      \[\leadsto \color{blue}{{\left(\frac{-1}{im}\right)}^{-1}}\]

    if 1.2688591977550717e+154 < re

    1. Initial program 59.4

      \[\sqrt{re \cdot re + im \cdot im}\]
    2. Taylor expanded around inf 7.6

      \[\leadsto \color{blue}{re}\]
  3. Recombined 5 regimes into one program.

Runtime

Time bar (total: 27.6s)Debug logProfile

herbie shell --seed '#(1071501266 3581234924 1086666455 2685055582 1243441566 1802958749)' 
(FPCore (re im)
  :name "math.abs on complex"
  (sqrt (+ (* re re) (* im im))))