[Bug tree-optimization/98113] [11 Regression] popcnt is not vectorized on s390 since f5e18dd9c7da

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98113

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Assignee|unassigned at gcc dot gnu.org      |rguenth at gcc dot 
gnu.org
   Target Milestone|---                         |11.0
             Target|                            |x86_64-*-* s390x-*-*
           Keywords|                            |missed-optimization

--- Comment #3 from Richard Biener <rguenth at gcc dot gnu.org> ---
The most straight-forward approach would be to treat

  r_14 = BIT_INSERT_EXPR <r_15(D), _18, 0 (32 bits)>;
  r_33 = BIT_INSERT_EXPR <r_14, _27, 32 (32 bits)>;
  r_32 = BIT_INSERT_EXPR <r_33, _36, 64 (32 bits)>;
  r_31 = BIT_INSERT_EXPR <r_32, _3, 96 (32 bits)>;

itself as a SLP source much like we look for CTORs as SLP source.  Note the
transformed load is an extra complication but at least I added support to
SLP existing vectors.

Also regresses on x86_64.

I'll see whether I can cook up sth.