[Bug tree-optimization/89184] GCC does not simplify expressions involving shifts, bitwise operators and comparisons.

[glisse at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=89184

--- Comment #1 from Marc Glisse <glisse at gcc dot gnu.org> ---
So in high level terms (let's not do asm when we don't need to), you want
  ((i >> 1) & 3) == 2
replaced with
  i & (3 << 1) == (2 << 1)
(as long as (i>>1) and (i>>1)&3 are not used for anything else)

That makes sense.