Average Error: 37.8 → 14.5
Time: 16.2s
Precision: 64
Internal Precision: 128
\[0.5 \cdot \sqrt{2.0 \cdot \left(\sqrt{re \cdot re + im \cdot im} + re\right)}\]
\[\left(\sqrt{\sqrt{(\left(\sqrt{\sqrt{re^2 + im^2}^*} \cdot \sqrt{\sqrt{re^2 + im^2}^*}\right) \cdot 2.0 + \left(2.0 \cdot re\right))_*}} \cdot \sqrt{\sqrt{(\left(\sqrt{\sqrt{re^2 + im^2}^*} \cdot \sqrt{\sqrt{re^2 + im^2}^*}\right) \cdot 2.0 + \left(2.0 \cdot re\right))_*}}\right) \cdot 0.5\]

Error

Bits error versus re

Bits error versus im

Target

Original37.8
Target33.0
Herbie14.5
\[\begin{array}{l} \mathbf{if}\;re \lt 0:\\ \;\;\;\;0.5 \cdot \left(\sqrt{2} \cdot \sqrt{\frac{im \cdot im}{\sqrt{re \cdot re + im \cdot im} - re}}\right)\\ \mathbf{else}:\\ \;\;\;\;0.5 \cdot \sqrt{2.0 \cdot \left(\sqrt{re \cdot re + im \cdot im} + re\right)}\\ \end{array}\]

Derivation

  1. Initial program 37.8

    \[0.5 \cdot \sqrt{2.0 \cdot \left(\sqrt{re \cdot re + im \cdot im} + re\right)}\]
  2. Initial simplification13.2

    \[\leadsto 0.5 \cdot \sqrt{(\left(\sqrt{re^2 + im^2}^*\right) \cdot 2.0 + \left(re \cdot 2.0\right))_*}\]
  3. Using strategy rm
  4. Applied add-sqr-sqrt14.2

    \[\leadsto 0.5 \cdot \sqrt{(\color{blue}{\left(\sqrt{\sqrt{re^2 + im^2}^*} \cdot \sqrt{\sqrt{re^2 + im^2}^*}\right)} \cdot 2.0 + \left(re \cdot 2.0\right))_*}\]
  5. Using strategy rm
  6. Applied add-sqr-sqrt14.5

    \[\leadsto 0.5 \cdot \color{blue}{\left(\sqrt{\sqrt{(\left(\sqrt{\sqrt{re^2 + im^2}^*} \cdot \sqrt{\sqrt{re^2 + im^2}^*}\right) \cdot 2.0 + \left(re \cdot 2.0\right))_*}} \cdot \sqrt{\sqrt{(\left(\sqrt{\sqrt{re^2 + im^2}^*} \cdot \sqrt{\sqrt{re^2 + im^2}^*}\right) \cdot 2.0 + \left(re \cdot 2.0\right))_*}}\right)}\]
  7. Final simplification14.5

    \[\leadsto \left(\sqrt{\sqrt{(\left(\sqrt{\sqrt{re^2 + im^2}^*} \cdot \sqrt{\sqrt{re^2 + im^2}^*}\right) \cdot 2.0 + \left(2.0 \cdot re\right))_*}} \cdot \sqrt{\sqrt{(\left(\sqrt{\sqrt{re^2 + im^2}^*} \cdot \sqrt{\sqrt{re^2 + im^2}^*}\right) \cdot 2.0 + \left(2.0 \cdot re\right))_*}}\right) \cdot 0.5\]

Runtime

Time bar (total: 16.2s)Debug logProfile

BaselineHerbieOracleSpan%
Regimes14.514.513.01.60%
herbie shell --seed 2018351 +o rules:numerics
(FPCore (re im)
  :name "math.sqrt on complex, real part"

  :herbie-target
  (if (< re 0) (* 0.5 (* (sqrt 2) (sqrt (/ (* im im) (- (sqrt (+ (* re re) (* im im))) re))))) (* 0.5 (sqrt (* 2.0 (+ (sqrt (+ (* re re) (* im im))) re)))))

  (* 0.5 (sqrt (* 2.0 (+ (sqrt (+ (* re re) (* im im))) re)))))