Average Error: 33.8 → 6.9
Time: 6.0s
Precision: binary64
\[\]
\[\]

Error

Bits error versus a

Bits error versus b_2

Bits error versus c

Derivation

  1. Split input into 4 regimes
  2. if b_2 < -446010382391396610

    1. Initial program 56.1

      \[\]
    2. Using strategy rm
    3. Applied flip--56.1

      \[\leadsto \]
    4. Simplified26.7

      \[\leadsto \]
    5. Simplified26.7

      \[\leadsto \]
    6. Using strategy rm
    7. Applied *-un-lft-identity26.7

      \[\leadsto \]
    8. Applied *-un-lft-identity26.7

      \[\leadsto \]
    9. Applied times-frac26.7

      \[\leadsto \]
    10. Simplified26.7

      \[\leadsto \]
    11. Simplified23.0

      \[\leadsto \]
    12. Taylor expanded around -inf 7.7

      \[\leadsto \]
    13. Simplified5.1

      \[\leadsto \]

    if -446010382391396610 < b_2 < 3.11018247161006561e-199

    1. Initial program 24.7

      \[\]
    2. Using strategy rm
    3. Applied flip--24.8

      \[\leadsto \]
    4. Simplified16.6

      \[\leadsto \]
    5. Simplified16.6

      \[\leadsto \]
    6. Using strategy rm
    7. Applied *-un-lft-identity16.6

      \[\leadsto \]
    8. Applied *-un-lft-identity16.6

      \[\leadsto \]
    9. Applied times-frac16.6

      \[\leadsto \]
    10. Simplified16.6

      \[\leadsto \]
    11. Simplified10.9

      \[\leadsto \]

    if 3.11018247161006561e-199 < b_2 < 1.1464830517773706e127

    1. Initial program 6.2

      \[\]
    2. Using strategy rm
    3. Applied clear-num6.4

      \[\leadsto \]

    if 1.1464830517773706e127 < b_2

    1. Initial program 53.1

      \[\]
    2. Using strategy rm
    3. Applied flip--63.7

      \[\leadsto \]
    4. Simplified62.7

      \[\leadsto \]
    5. Simplified62.7

      \[\leadsto \]
    6. Taylor expanded around 0 2.8

      \[\leadsto \]
    7. Simplified2.8

      \[\leadsto \]
  3. Recombined 4 regimes into one program.
  4. Final simplification6.9

    \[\leadsto \]

Reproduce

herbie shell --seed 2020181 
(FPCore (a b_2 c)
  :name "quad2m (problem 3.2.1, negative)"
  :precision binary64
  (/ (- (neg b_2) (sqrt (- (* b_2 b_2) (* a c)))) a))