[Bug tree-optimization/126457] [16/17 Regression] ICE at -O2/3 on aarch64 during GIMPLE pass: vect

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=126457

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Last reconfirmed|                            |2026-07-29
     Ever confirmed|0                           |1
           Assignee|unassigned at gcc dot gnu.org      |rguenth at gcc dot gnu.org
   Target Milestone|---                         |16.2
             Status|UNCONFIRMED                 |ASSIGNED

--- Comment #1 from Richard Biener <rguenth at gcc dot gnu.org> ---
This is another latent issue - reduction operation handling doesn't know of the
special case vectorizable_call has:

  /* Similarly pretend IFN_CLZ and IFN_CTZ only has one argument, the second
     argument just says whether it is well-defined at zero or not and what
     value should be returned for it.  */
  if ((cfn == CFN_CLZ || cfn == CFN_CTZ) && nargs == 2)
    {
      nargs = 1;
      clz_ctz_arg1 = gimple_call_arg (stmt, 1);
    }

now, this isn't going to be a reduction operation, but we're ICEing
trying to inspect call argument 1 which is done before we validate that.