Apparent OMP bugs in ifort 19.xx

Hello all, I've been trying to compile and run code with intel 19 (19.0.5 and 19.1.0.166) that had been working fine with ifort 18.0.5 but without much success. I've been getting various segfaults that seem to occur at the intersection of openmp and O3 optimization. I was able to come up with a simple code (below) that reproduces a problem, although I'm not certain it is precisely the problem I'm having in my real code as it doesn't manifest in quite the same way.

For the simple code, I find that when I compile with "-qopenmp" and run with several threads I correctly get

Flags: -qopenmp

 Checksum 1 =    151500000.000000
 Checksum 2 =    151500000.000000
 Checksum 3 =   0.000000000000000E+000

whereas when using optimization I instead get,

Flags: -qopenmp -O3

 Checksum 1 =    151500000.000000
 Checksum 2 =    151500000.000000
 Checksum 3 =    1617187600.00000

The code works in 18.xx with both compiler options. I also notice that if I try to compile the simple code with "-qopenmp -O3 -fPIC" I get the strange compiler error,

/tmp/ifortz68jYX.i90: catastrophic error: **Internal compiler error: segmentation violation signal raised** Please report this error along with the circumstances in which it occurred in a Software Problem Report.  Note: File and line given may not be explicit cause of this error.

although if I compile my full code with "fPIC" I do not get that error (although it doesn't work). In the simple reproducer the code runs but the numbers are wrong, whereas in my real code I get a seg fault that seems to be related to the array-valued function used in the OMP loop nest. The size of the array is only 3x1 though and I'm specifying both "ulimit -s unlimited" and OMP_STACKSIZE to be more than sufficient.

Thanks in advance for any help you can provide.

module math
	use, intrinsic :: iso_fortran_env
	implicit none
	integer, parameter :: rp = REAL64
	integer, parameter :: NDIM = 3
	integer, parameter :: N = 100
	contains

    function cross(a, b)

        real(rp), dimension(NDIM), intent(in) :: a, b
        real(rp), dimension(NDIM) :: cross

        cross(1) = a(2)*b(3) - a(3)*b(2)
        cross(2) = a(3)*b(1) - a(1)*b(3)
        cross(3) = a(1)*b(2) - a(2)*b(1)

    end function cross

end module math

program ompbug
	use math

	implicit none

	integer :: i,j,k
	real(rp), allocatable, dimension(:,:,:,:) :: Q1,Q2,Q3
	real(rp), dimension(NDIM) :: V1,V2

	allocate(Q1(N,N,N,NDIM))
	allocate(Q2(N,N,N,NDIM))
	allocate(Q3(N,N,N,NDIM))

    !$OMP PARALLEL DO default(shared) collapse(2) &
    !$OMP private(i,j,k,V1,V2)
	do i=1,N
		do j=1,N
			do k=1,N
				V1 = [1.0*i,1.0*j,1.0*k]
				V2 = [1.0*k,1.0*j,1.0*i]
				Q1(i,j,k,:) = V1
				Q2(i,j,k,:) = V2
				Q3(i,j,k,:) = cross(V1,V2)
			enddo
		enddo
	enddo

	write(*,*) 'Checksum 1 = ', sum(Q1)
	write(*,*) 'Checksum 2 = ', sum(Q2)
	write(*,*) 'Checksum 3 = ', sum(Q3)

end program ompbug