[Bug middle-end/111378] Missed optimization for comparing with exact_log2 constants

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111378

ktkachov at gcc dot gnu.org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
     Ever confirmed|0                           |1
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2023-09-12
                 CC|                            |ktkachov at gcc dot gnu.org

--- Comment #1 from ktkachov at gcc dot gnu.org ---
Confirmed. On aarch64 GCC generates:
test:
        mov     w2, 65535
        cmp     w1, w2
        bhi     .L2
        b       do_something
.L2:
        b       do_something_other

but LLVM generates the shorter:
test:                                   // @test
        lsr     w8, w1, #16
        cbnz    w8, .LBB0_2
        b       do_something
.LBB0_2:
        b       do_something_other