https://gcc.gnu.org/bugzilla/show_bug.cgi?id=89651
Bug ID: 89651
Summary: OpenMP private array uninitialized warning with -O
flag
Product: gcc
Version: 8.2.1
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: fortran
Assignee: unassigned at gcc dot gnu.org
Reporter: jfeng33 at hotmail dot com
Target Milestone: ---
A private array variable generates an uninitialized warning when compiled with
-O, -O1, -O2, -O3. Without optimization flag, no error.
==============================================
program omp_array_private
use omp_lib
integer :: n
real, allocatable :: t(:)
real :: s
n=10
allocate(t(n),source=0.0)
!$omp parallel private(t)
s=sum(t)
!$omp end parallel
end program omp_array_private
==============================================
compile flag : gfortran -O3 -fopenmp -Wall
++++++++++++++++++++++++++++++++++++++++++++++
Results:
Warning: ‘t.dim[0].lbound’ may be used uninitialized in this function
[-Wmaybe-uninitialized]
Warning: ‘t.dim[0].ubound’ may be used uninitialized in this function
[-Wmaybe-uninitialized]
Warning: ‘t.offset’ may be used uninitialized in this function
[-Wmaybe-uninitialized]
