https://gcc.gnu.org/bugzilla/show_bug.cgi?id=127731
Bug ID: 127731
Summary: Wrong values from a pointer function result associated
with a complex part designator
Product: gcc
Version: 16.2.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: fortran
Assignee: unassigned at gcc dot gnu.org
Reporter: ivan.pribec at gmail dot com
Target Milestone: ---
Using the imaginary component of a complex array returned via a procedure
pointer, gives wrong results when the function is used as a value.
This happens in an expression, an associate statement, as a procedure actual
argument, and when the result is assigned to an unlimited polymorphic pointer.
Pointer assignment works correctly.
The error was found using Claude Fable. It works as expected with ifx and
flang.
program p
implicit none
complex, target :: z(3) = [(1., 2.), (3., 4.), (5., 6.)]
real, pointer :: r(:)
class(*), pointer :: q(:)
print *, 'expression: ', g() ! 2. 4. 6.
print *, 'sum: ', sum(g()) ! 12.
associate (a => g())
print *, 'associate: ', a ! 2. 4. 6.
end associate
call show('actual argument: ', g()) ! 2. 4. 6.
q => f()
select type (q)
type is (real)
print *, 'CLASS(*) q => f():', q ! 2. 4. 6.
end select
r => g()
print *, 'REAL r => g(): ', r ! 2. 4. 6. (works)
contains
function g() result(res)
real, pointer :: res(:)
res => z%im
end function
function f() result(res)
class(*), pointer :: res(:)
res => z%im
end function
subroutine show(label, d)
character(*), intent(in) :: label
real, intent(in) :: d(:)
print *, label, d
end subroutine
end program
