FYI.
Begin forwarded message:
From: "Benjamin Réveillé" <[EMAIL PROTECTED]>
Date: May 2, 2006 7:44:38 AM PDT
To: [EMAIL PROTECTED]
Subject: Problem with OpenMP Reduction Clause
Hello
I've stumbled onto a problem with the OpenMP REDUCTION clause
Here is the reduced code array_reduction.f90
##########################################
program array_reduction
implicit none
integer, parameter :: n=10,m=1000
integer :: i
integer, dimension(n) :: sumarray
!
call foo(n,m,sumarray)
do i=1,n
print*,sumarray(i)
end do
end program array_reduction
subroutine foo(n,m,sumarray)
use omp_lib, only : omp_get_thread_num
implicit none
integer, intent(in) :: n,m
integer, dimension(n), intent(out) :: sumarray
!
integer :: i,j
!
sumarray(:)=0
!$OMP PARALLEL DEFAULT(shared)
print*,'hello from thread ',omp_get_thread_num()
!$OMP DO PRIVATE(j,i), REDUCTION(+:sumarray)
do j=1,m
do i=1,n
sumarray(i)=sumarray(i)+i
end do
end do
!$OMP END DO
!$OMP END PARALLEL
end subroutine foo
##########################################
pgi 6.1 and xlf10.1 both compile and execute with the following
correct output:
hello from thread 1
hello from thread 0
1000
2000
3000
4000
5000
6000
7000
8000
9000
10000
Intel 9.1 compiles but [Abort]s on execution.
gfortran
Using built-in specs.
Target: i386-linux
Configured with: ../gcc/configure
--prefix=/cosmic/coudert/tmp/gfortran-20060502/irun
--enable-languages=c,fortran --host=i386-linux
--with-gmp=/cosmic/coudert/tmp/gfortran-20060502/gfortran_libs
Thread model: posix
gcc version 4.2.0 20060502 (experimental)
gfortran segfault on compile (gfortran -fopenmp array_reduction.f90)
with the following message:
arrayreduction.f90: In function 'foo':
arrayreduction.f90:14: internal compiler error: Segmentation fault
Please submit a full bug report,
with preprocessed source if appropriate.
See <URL:http://gcc.gnu.org/bugs.html> for instructions.
My understanding (from following the mailing list) is that the
segfault itself is a gfortran bug...
Should I therefore file one ?
My 2nd question is is the coding valid ??? From reading page 83 of the
OpenMP 2.5 Specifications
(http://www.openmp.org/drupal/mp-documents/spec25.pdf) I tend to think
that sumarray is a valid array for the REDUCTION clause. I wonder
still since INTEL compilers seem to have a problem with it too.
Thanks for your help
