[Bug middle-end/106231] sign-extension of the result of `__builtin_ctz`

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106231

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
          Component|target                      |middle-end
     Ever confirmed|0                           |1
           Severity|normal                      |enhancement
   Last reconfirmed|                            |2022-07-08
            Summary|sign-extension of the       |sign-extension of the
                   |result of                   |result of `__builtin_ctz`
                   |`__builtin_tzcnt()`         |

--- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Confirmed.

There could be an easy pattern added for:
Failed to match this instruction:
(set (reg:DI 88 [ _1 ])
    (sign_extend:DI (ctz:SI (reg:SI 90))))

And for :

Failed to match this instruction:
(set (reg:DI 89 [ _1 ])
    (zero_extend:DI (ctz:SI (reg:SI 91))))