http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55100
Bug #: 55100
Summary: FORALL: If the RHS is scalar, not array temporary is
needed
Classification: Unclassified
Product: gcc
Version: 4.8.0
Status: UNCONFIRMED
Keywords: missed-optimization
Severity: normal
Priority: P3
Component: fortran
AssignedTo: unassig...@gcc.gnu.org
ReportedBy: bur...@gcc.gnu.org
As the dump shows, gfortran generates a temporary array in this case. While a
temporary is needed, a scalar temporary is sufficient if/as the RHS is a scalar
(or a an array element which doesn't depend on the forall index).
implicit none
type inner
integer :: i = 5
end type inner
type t
integer :: i
type(inner), pointer :: str
end type t
type(t), pointer :: y(:)
type(inner), target :: tgt
integer :: i, n
n = 10
allocate(y(n))
forall(i=1:n) y(i)%str => null() ! Ok, no tmp needed
forall(i=1:n) y(i)%i = 5 ! Ok, no tmp needed
do i = 1, n
if (associated(y(i)%str)) stop 'ERROR'
if (y(i)%i /= 5) stop 'ERROR'
end do
forall(i=1:n) y(i)%str => tgt ! Only scalar tmp needed
do i = 1, n
if (.not. associated(y(i)%str,tgt)) stop 'ERROR'
end do
! Pointless assignment of the value from tgt to tgt
forall(i=1:n) y(i)%str = tgt ! Only scalar tmp needed
end
