Warning when -qopenmp is used

[Jeremie_V_]

Dear,

I got the following warning when using ifort on a Linux computer, and I am wondering what it means, and how I can avoid it. I googled it, but I am not sure that I fully understood the problem.

The warning message I get is:

ifort: warning #10247: explicit static allocation of locals specified, overriding OpenMP*'s implicit auto allocation

The version of ifort is:

ifort (IFORT) 16.0.3 20160415
Copyright (C) 1985-2016 Intel Corporation.  All rights reserved.

The program that I compiled is:

program  essai
 implicit none
 integer::i,j,io,un

 print*,"Hello world"
contains

subroutine numlines(unfile,n)
 implicit none
 integer::io
 integer,intent(in)::unfile
 integer,intent(out)::n
 rewind(unfile)
 n=0
 do
  read(unfile,*,iostat=io)
  if (io.ne.0) exit
  n=n+1
 enddo
 rewind(unfile)
end subroutine

end program

and the command line is:

ifort -qopenmp essai.f90

I got the same warning message with more complex codes and command lines involving Openmp and MKL. I am compiling the same codes on other clusters with the same command lines without getting this warning. So, I am wondering why this warning appears on this specific computer, how I can avoid it, and what could be the consequences if I cannot avoid it.

In advance thank you.

Yours sincerely,

Jeremie

[TimP]

If the warning occurs only when you have no omp parallel directive, it may be of no consequence.  Explicit local static allocation of a variable which is update inside an omp parallel region would be expected to create a race condition.

If this warning is specific to one installation of ifort, you should look for ifort.cfg in your ifort installation to see if there are settings there, or set -qopt-report and look for additional compiler flags on this installation.  You may wish to remove or over-ride any such flags.

[Jeremie_V_]

Thank you for your help. A file ifor,cfg contains some options (e.g. -save) and was mentioned through the environment variable IFORTCFG. Unsetting this environment variable solves the warning.

Jeremie