[Bug tree-optimization/91568] internal compiler error: in vect_schedule_slp_instance, at tree-vect-slp.c:3922

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91568

--- Comment #7 from Richard Biener <rguenth at gcc dot gnu.org> ---
So the fixing rev. makes us not sink stmts into a loop (in this case the
invariant division 1./z) so the issue is probably latent.  Reduced testcase
w/o undefined behavior:

      subroutine h3dall(z,hvec,hder,nterms)
      complex *16 hvec(0:1),hder(0:1)
      complex *16 z,zinv,ztmp/1.0/
      zinv=1.0/z
      do i=1,nterms
         ztmp=zinv*i
         hder(i)=hvec(i-1)-ztmp*hvec(i)
      enddo
      end