[Bug tree-optimization/101403] [12 Regression] wrong code with __builtin_bswap16() at -O1 by r12-2137

[hjl.tools at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101403

H.J. Lu <hjl.tools at gmail dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |hjl.tools at gmail dot com
     Ever confirmed|0                           |1
             Status|UNCONFIRMED                 |NEW
            Summary|[12 Regression] wrong code  |[12 Regression] wrong code
                   |with __builtin_bswap16() at |with __builtin_bswap16() at
                   |-O1                         |-O1 by r12-2137
   Last reconfirmed|                            |2021-07-10

--- Comment #2 from H.J. Lu <hjl.tools at gmail dot com> ---
This is introduced by

commit 4c619132b3f14dc5e672a7f2f0e09cb784193559
Author: Roger Sayle <roger@nextmovesoftware.com>
Date:   Thu Jul 8 11:46:14 2021 +0100

    PR tree-optimization/40210: Fold (bswap(X)>>C1)&C2 to (X>>C3)&C2 in
match.pd