[Bug middle-end/80131] powerpc: 1U << (31 - x) doesn't generate optimised code

[ktkachov at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80131

ktkachov at gcc dot gnu.org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |missed-optimization
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2017-03-21
                 CC|                            |ktkachov at gcc dot gnu.org
          Component|c                           |middle-end
     Ever confirmed|0                           |1

--- Comment #1 from ktkachov at gcc dot gnu.org ---
On aarch64 we also get:
f1:
        mov     w1, 31
        mov     w2, 1
        sub     w0, w1, w0
        lsl     w0, w2, w0
        ret

f2:
        mov     w1, -2147483648
        lsr     w0, w1, w0
        ret