[Octopus-devel] [Octopus-notify] svn commit: r4355 - trunk/src/states by lorenzen

[Tobias Burnus]

octopus-notify at tddft.org wrote:
>       Author: lorenzen
>         Date: Fri Jul  4 09:16:22 2008
> New Revision: 4355
>    Changeset: http://www.tddft.org/trac/octopus/changeset/4355
> Modified:
>    trunk/src/states/restart.F90
> Log:
> This fixes the failure of open_systems/03-extended_eigenstate.test in
> i386_gfortran_test:#356. It cirumvents a bug in GFortran.
>   

I would argue that this was a bug in Octopus and not in gfortran:


-  st%zphi((k-1)*m_lead%np+1:k*m_lead%np, idim, jst, k_index) = tmp
+ ! Do not write this inner loop as vector assignment. GFortran
+ ! has a problem with that. 
+ lb = (k-1)*m_lead%np+1
+ do ip = lb, k*m_lead%np
+   st%zphi(ip, idim, jst, k_index) = tmp(ip-lb+1)
+ end do

lb  is 1  and  k*m_lead%np  is two. Thus: LHS has a size of two. 
However, tmp and thus the RHS has a size of 12.
Thus LHS and RHS have a size mismatch.


In the explicit loop, one iterates over the LHS and thus it works. 
Similarly should work:

-  st%zphi((k-1)*m_lead%np+1:k*m_lead%np, idim, jst, k_index) = tmp
+  st%zphi((k-1)*m_lead%np+1:k*m_lead%np, idim, jst, k_index) = 
tmp(1:(k*m_lead%np)-(k-1)*m_lead%np+1)+1)


 * * *

Seemingly, this size mismatch this is not tested with g95 and ifort - at 
least for the following program "ifort -check all" and "g95 
-fbounds-check" produce no error:

integer,allocatable :: a(:)
integer :: b(1)
allocate(a(12))
b(:) = a
end

(gfortran and NAG f95 find the problem; NAG: "Rank 1 of A has extent 12 
instead of 1".)

 * * *

I therefore suggest the following patch:

Index: ../octopus-trunk/src/states/restart.F90
===================================================================
--- ../octopus-trunk/src/states/restart.F90     (Revision 4361)
+++ ../octopus-trunk/src/states/restart.F90
@@ -697,8 +697,6 @@
       ! It only works in this compact form because the 
transport-direction (x) is
       ! the index running slowest.
       do k = 1, 
nint(sb%lsize(TRANS_DIR)/gr%sb%lead_unit_cell(LEFT)%lsize(TRANS_DIR))
-        ! Do not write this inner loop as vector assignment. GFortran
-        ! has a problem with that.
         lb = (k-1)*m_lead%np+1
         do ip = lb, k*m_lead%np
           st%zphi(ip, idim, jst, k_index) = tmp(ip-lb+1)


An alternative would be to find out why tmp is too big and whether it is 
supposed to be too big.

Tobias