[Bug tree-optimization/110922] `(a == b) & (a == c) & (b != c)` is not optimized to false

[pinskia at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110922

--- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
I think you need the following 3 patterns, there might be more though:
(simplify
 (bit_and:c
  (bit_and:c
   (eq:c @0 @1)
   (eq:c @0 @2)
  )
  (ne:c @1 @2)
 )
 ( { falsevalue; } )
)
(simplify
 (bit_and:c
  (bit_and:c
   (eq:c @0 @1)
   (ne:c @1 @2)
  )
  (eq:c @0 @2)
 )
 ( { falsevalue; } )
)
(simplify
 (bit_and:c
  (eq:c @0 @1)
  (bit_and:c
   (ne:c @1 @2)
   (eq:c @0 @2)
  )
 )
 ( { falsevalue; } )
)