Average Error: 37.4 → 12.8
Time: 11.6s
Precision: 64
Internal Precision: 3392
\[0.5 \cdot \sqrt{2.0 \cdot \left(\sqrt{re \cdot re + im \cdot im} + re\right)}\]
\[\sqrt{(\left(\sqrt{re^2 + im^2}^*\right) \cdot 2.0 + \left(2.0 \cdot re\right))_*} \cdot 0.5\]

Error

Bits error versus re

Bits error versus im

Target

Original37.4
Target32.3
Herbie12.8
\[\begin{array}{l} \mathbf{if}\;re \lt 0:\\ \;\;\;\;0.5 \cdot \left(\sqrt{2} \cdot \sqrt{\frac{im \cdot im}{\sqrt{re \cdot re + im \cdot im} - re}}\right)\\ \mathbf{else}:\\ \;\;\;\;0.5 \cdot \sqrt{2.0 \cdot \left(\sqrt{re \cdot re + im \cdot im} + re\right)}\\ \end{array}\]

Derivation

  1. Initial program 37.4

    \[0.5 \cdot \sqrt{2.0 \cdot \left(\sqrt{re \cdot re + im \cdot im} + re\right)}\]
  2. Initial simplification12.8

    \[\leadsto 0.5 \cdot \sqrt{(\left(\sqrt{re^2 + im^2}^*\right) \cdot 2.0 + \left(re \cdot 2.0\right))_*}\]
  3. Using strategy rm
  4. Applied add-sqr-sqrt14.0

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

    \[\leadsto 0.5 \cdot \sqrt{(\left(\sqrt{\sqrt{re^2 + im^2}^*} \cdot \color{blue}{\left(\sqrt{\sqrt{\sqrt{re^2 + im^2}^*}} \cdot \sqrt{\sqrt{\sqrt{re^2 + im^2}^*}}\right)}\right) \cdot 2.0 + \left(re \cdot 2.0\right))_*}\]
  7. Applied associate-*r*14.3

    \[\leadsto 0.5 \cdot \sqrt{(\color{blue}{\left(\left(\sqrt{\sqrt{re^2 + im^2}^*} \cdot \sqrt{\sqrt{\sqrt{re^2 + im^2}^*}}\right) \cdot \sqrt{\sqrt{\sqrt{re^2 + im^2}^*}}\right)} \cdot 2.0 + \left(re \cdot 2.0\right))_*}\]
  8. Using strategy rm
  9. Applied pow114.3

    \[\leadsto 0.5 \cdot \sqrt{(\left(\left(\sqrt{\sqrt{re^2 + im^2}^*} \cdot \sqrt{\sqrt{\sqrt{re^2 + im^2}^*}}\right) \cdot \color{blue}{{\left(\sqrt{\sqrt{\sqrt{re^2 + im^2}^*}}\right)}^{1}}\right) \cdot 2.0 + \left(re \cdot 2.0\right))_*}\]
  10. Applied pow114.3

    \[\leadsto 0.5 \cdot \sqrt{(\left(\color{blue}{{\left(\sqrt{\sqrt{re^2 + im^2}^*} \cdot \sqrt{\sqrt{\sqrt{re^2 + im^2}^*}}\right)}^{1}} \cdot {\left(\sqrt{\sqrt{\sqrt{re^2 + im^2}^*}}\right)}^{1}\right) \cdot 2.0 + \left(re \cdot 2.0\right))_*}\]
  11. Applied pow-prod-down14.3

    \[\leadsto 0.5 \cdot \sqrt{(\color{blue}{\left({\left(\left(\sqrt{\sqrt{re^2 + im^2}^*} \cdot \sqrt{\sqrt{\sqrt{re^2 + im^2}^*}}\right) \cdot \sqrt{\sqrt{\sqrt{re^2 + im^2}^*}}\right)}^{1}\right)} \cdot 2.0 + \left(re \cdot 2.0\right))_*}\]
  12. Simplified12.8

    \[\leadsto 0.5 \cdot \sqrt{(\left({\color{blue}{\left(\sqrt{re^2 + im^2}^*\right)}}^{1}\right) \cdot 2.0 + \left(re \cdot 2.0\right))_*}\]
  13. Final simplification12.8

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

Runtime

Time bar (total: 11.6s)Debug logProfile

BaselineHerbieOracleSpan%
Regimes12.812.812.60.20%
herbie shell --seed 2018295 +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)))))