[Bug tree-optimization/125177] BB SLP graph partitioning is not correct

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=125177

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |ASSIGNED
           Assignee|unassigned at gcc dot gnu.org      |rguenth at gcc dot 
gnu.org
   Last reconfirmed|                            |2026-05-05
     Ever confirmed|0                           |1

--- Comment #1 from Richard Biener <rguenth at gcc dot gnu.org> ---
Mine.  The scalar coverage walk can be used to also partition the graph I
think,
effectively re-ordering

  /* Mark all the statements that we vectorize.  */
  vect_bb_slp_mark_stmts_vectorized (bb_vinfo);

  /* Compute vectorizable live stmts.  */
  vect_bb_slp_mark_live_stmts (bb_vinfo);

  vect_bb_partition_graph (bb_vinfo);

as

  /* Mark all the statements that we vectorize.  */
  vect_bb_slp_mark_stmts_vectorized_and_partition_graph (bb_vinfo);

  /* Compute vectorizable live stmts.  */
  vect_bb_slp_mark_live_stmts (bb_vinfo);