[Bug tree-optimization/111431] a & (a == 0) is not optimized to 0

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111431

--- Comment #2 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
The pattern should be:

(simplify
 (bit_and:c (convert@2 (eq @0 INTEGER_CST@1)) (convert? @0))
 (if ((wi::to_wide (@1) & 1) != 0)
  @2
  { build_zero_cst (type); }))

Since 0/1 of the eq, the convert on the @0 inside the bit_and does not matter.