[Bug target/112398] Suboptimal code generation for xor pattern on subword data

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112398

Andrew Pinski <pinskia at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |WAITING
   Last reconfirmed|                            |2023-11-05
     Ever confirmed|0                           |1

--- Comment #2 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Also it depends on the ABI since the return value on many targets' ABI don't
care about the upper bits.

For an example on aarch64 we get:
neg8:
        ldrb    w0, [x0]
        mvn     w0, w0
        ret
neg16:
        ldrh    w0, [x0]
        mvn     w0, w0
        ret