It's reduced from 454.calculix:

$ cat deuldlag.f
      subroutine deuldlag(xi,et,ze,xlag,xeul,xj,xs)
      real*8 shp(3,20),xs(3,3),xlag(3,20),xeul(3,20)
      do i=1,3
        do j=1,3
        enddo
      enddo
      do i=1,3
        do j=1,3
          xs(i,j)=0.d0
          do k=1,20
            xs(i,j)=xs(i,j)+xeul(i,k)*shp(j,k)
          enddo
        enddo
      enddo
      end

$ gcc -O3 deuldlag.f -c
during GIMPLE pass: vect
deuldlag.f:1:0:

    1 |       subroutine deuldlag(xi,et,ze,xlag,xeul,xj,xs)
      | 
internal compiler error: Segmentation fault
0xeb3cff crash_signal
	/home/marxin/Programming/gcc/gcc/toplev.c:328
0x7ffff78f6f3f ???
	/usr/src/debug/glibc-2.31-5.1.x86_64/signal/../sysdeps/unix/sysv/linux/x86_64/sigaction.c:0
0x10f94e3 nested_in_vect_loop_p
	/home/marxin/Programming/gcc/gcc/tree-vectorizer.h:1260
0x10f94e3 vect_init_vector_1
	/home/marxin/Programming/gcc/gcc/tree-vect-stmts.c:1333
0x10f972a vect_init_vector(vec_info*, _stmt_vec_info*, tree_node*, tree_node*, gimple_stmt_iterator*)
	/home/marxin/Programming/gcc/gcc/tree-vect-stmts.c:1418
0x1144449 vect_create_constant_vectors
	/home/marxin/Programming/gcc/gcc/tree-vect-slp.c:3745
0x1144449 vect_schedule_slp_instance
	/home/marxin/Programming/gcc/gcc/tree-vect-slp.c:4066
0x1144938 vect_schedule_slp_instance
	/home/marxin/Programming/gcc/gcc/tree-vect-slp.c:4071
0x114a982 vect_schedule_slp(vec_info*)
	/home/marxin/Programming/gcc/gcc/tree-vect-slp.c:4303
0x113543e vect_transform_loop(_loop_vec_info*, gimple*)
	/home/marxin/Programming/gcc/gcc/tree-vect-loop.c:8753
0x1150edf try_vectorize_loop_1
	/home/marxin/Programming/gcc/gcc/tree-vectorizer.c:988
0x1151b89 vectorize_loops()
	/home/marxin/Programming/gcc/gcc/tree-vectorizer.c:1125
Please submit a full bug report,
with preprocessed source if appropriate.
Please include the complete backtrace with any bug report.
See <https://gcc.gnu.org/bugs/> for instructions.