[Bug target/100981] New: ICE in info_for_reduction, at tree-vect-loop.c:4897

[asolokha at gmx dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100981

            Bug ID: 100981
           Summary: ICE in info_for_reduction, at tree-vect-loop.c:4897
           Product: gcc
           Version: 12.0
            Status: UNCONFIRMED
          Keywords: ice-on-valid-code
          Severity: normal
          Priority: P3
         Component: target
          Assignee: unassigned at gcc dot gnu.org
          Reporter: asolokha at gmx dot com
  Target Milestone: ---
            Target: aarch64-linux-gnu

gfortran-12.0.0-alpha20210606 snapshot
(g:fed94fc9e704b0de228499495b7ca4d4c79ef76b) ICEs when compiling the following
testcase w/ -march=armv8.3-a -O3 -ftree-parallelize-loops=2 -fno-signed-zeros
-fno-trapping-math:

complex function cdcdot(n, cx)
  implicit none

  integer :: n, i, kx
  complex :: cx(*)
  double precision :: dsdotr, dsdoti, dt1, dt3

  kx = 1
  do i = 1, n
     dt1 = real(cx(kx))
     dt3 = aimag(cx(kx))
     dsdotr = dsdotr + dt1 * 2 - dt3 * 2
     dsdoti = dsdoti + dt1 * 2 + dt3 * 2
     kx = kx + 1
  end do
  cdcdot = cmplx(real(dsdotr), real(dsdoti))
  return
end function cdcdot

% aarch64-linux-gnu-gfortran-12.0.0 -march=armv8.3-a -O3
-ftree-parallelize-loops=2 -fno-signed-zeros -fno-trapping-math -c xrvsc8ow.f90
during GIMPLE pass: vect
xrvsc8ow.f90:9:8:

    9 |   do i = 1, n
      |        ^
internal compiler error: in info_for_reduction, at tree-vect-loop.c:4897
0x7c8b0d info_for_reduction(vec_info*, _stmt_vec_info*)
       
/var/tmp/portage/cross-aarch64-linux-gnu/gcc-12.0.0_alpha20210606/work/gcc-12-20210606/gcc/tree-vect-loop.c:4897
0x122d008 vectorizable_live_operation(vec_info*, _stmt_vec_info*,
gimple_stmt_iterator*, _slp_tree*, _slp_instance*, int, bool,
vec<stmt_info_for_cost, va_heap, vl_ptr>*)
       
/var/tmp/portage/cross-aarch64-linux-gnu/gcc-12.0.0_alpha20210606/work/gcc-12-20210606/gcc/tree-vect-loop.c:8547
0x11ed1d7 can_vectorize_live_stmts
       
/var/tmp/portage/cross-aarch64-linux-gnu/gcc-12.0.0_alpha20210606/work/gcc-12-20210606/gcc/tree-vect-stmts.c:10619
0x1216858 vect_transform_stmt(vec_info*, _stmt_vec_info*,
gimple_stmt_iterator*, _slp_tree*, _slp_instance*)
       
/var/tmp/portage/cross-aarch64-linux-gnu/gcc-12.0.0_alpha20210606/work/gcc-12-20210606/gcc/tree-vect-stmts.c:11003
0x124b296 vect_schedule_slp_node
       
/var/tmp/portage/cross-aarch64-linux-gnu/gcc-12.0.0_alpha20210606/work/gcc-12-20210606/gcc/tree-vect-slp.c:6302
0x12596cc vect_schedule_scc
       
/var/tmp/portage/cross-aarch64-linux-gnu/gcc-12.0.0_alpha20210606/work/gcc-12-20210606/gcc/tree-vect-slp.c:6516
0x125a71f vect_schedule_slp(vec_info*, vec<_slp_instance*, va_heap, vl_ptr>)
       
/var/tmp/portage/cross-aarch64-linux-gnu/gcc-12.0.0_alpha20210606/work/gcc-12-20210606/gcc/tree-vect-slp.c:6580
0x1236e7c vect_transform_loop(_loop_vec_info*, gimple*)
       
/var/tmp/portage/cross-aarch64-linux-gnu/gcc-12.0.0_alpha20210606/work/gcc-12-20210606/gcc/tree-vect-loop.c:9538
0x1265f0f try_vectorize_loop_1
       
/var/tmp/portage/cross-aarch64-linux-gnu/gcc-12.0.0_alpha20210606/work/gcc-12-20210606/gcc/tree-vectorizer.c:1104
0x1266ca0 vectorize_loops()
       
/var/tmp/portage/cross-aarch64-linux-gnu/gcc-12.0.0_alpha20210606/work/gcc-12-20210606/gcc/tree-vectorizer.c:1243