openacc: Don't strip TO_PSET/POINTER for enter/exit data

OpenACC 2.6 specifies that the array descriptor (when present) must be
copied to the target before attaching pointers in Fortran. This patch
reverses the stripping of GOMP_MAP_TO_PSET and GOMP_MAP_POINTER that
was introduced by the "OpenACC reference count overhaul" patch.

2020-07-10  Julian Brown  <julian@codesourcery.com>
	    Thomas Schwinge  <thomas@codesourcery.com>

gcc/
	* gimplify.c (gimplify_scan_omp_clauses): Do not strip
	GOMP_MAP_TO_PSET/GOMP_MAP_POINTER for OpenACC enter/exit data
	directives (see also PR92929).

gcc/testsuite/
	* gfortran.dg/goacc/finalize-1.f: Update expected dump output.

libgomp/
	* testsuite/libgomp.oacc-fortran/dynamic-pointer-1.f90: New test.

Co-Authored-By: Thomas Schwinge <thomas@codesourcery.com>

1 files changed, 97 insertions, 0 deletions

diff --git a/libgomp/testsuite/libgomp.oacc-fortran/dynamic-pointer-1.f90 b/libgomp/testsuite/libgomp.oacc-fortran/dynamic-pointer-1.f90
new file mode 100644
index 0000000..4f38902
--- /dev/null
+++ b/libgomp/testsuite/libgomp.oacc-fortran/dynamic-pointer-1.f90
@@ -0,0 +1,97 @@
+! Verify that a 'enter data'ed 'pointer' object creates a persistent, visible device copy
+
+! { dg-do run }
+! { dg-skip-if "" { *-*-* } { "*" } { "-DACC_MEM_SHARED=0" } }
+
+module m
+  implicit none
+contains
+
+  subroutine verify_a (a_ref, a)
+    implicit none
+    integer, dimension (:, :, :), allocatable :: a_ref
+    integer, dimension (:, :, :), pointer :: a
+
+    !$acc routine seq
+
+    if (any (lbound (a) /= lbound (a_ref))) stop 101
+    if (any (ubound (a) /= ubound (a_ref))) stop 102
+    if (size (a) /= size (a_ref)) stop 103
+  end subroutine verify_a
+
+end module m
+
+program main
+  use m
+  use openacc
+  implicit none
+  integer, parameter :: n = 30
+  integer, dimension (:, :, :), allocatable, target :: a1, a2
+  integer, dimension (:, :, :), pointer :: p
+
+  allocate (a1(1:n, 0:n-1, 10:n/2))
+  !$acc enter data create(a1)
+  allocate (a2(3:n/3, 10:n, n-10:n+10))
+  !$acc enter data create(a2)
+
+  p => a1
+  call verify_a(a1, p)
+
+  ! 'p' object isn't present on the device.
+  !$acc parallel ! Implicit 'copy(p)'; creates 'p' object...
+  call verify_a(a1, p)
+  !$acc end parallel ! ..., and deletes it again.
+
+  p => a2
+  call verify_a(a2, p)
+
+  ! 'p' object isn't present on the device.
+  !$acc parallel ! Implicit 'copy(p)'; creates 'p' object...
+  call verify_a(a2, p)
+  !$acc end parallel ! ..., and deletes it again.
+
+  p => a1
+
+  !$acc enter data create(p)
+  ! 'p' object is now present on the device (visible device copy).
+  !TODO PR96080 if (.not. acc_is_present (p)) stop 1
+
+  !$acc parallel
+  ! On the device, got created as 'p => a1'.
+  call verify_a(a1, p)
+  !$acc end parallel
+  call verify_a(a1, p)
+
+  !$acc parallel
+  p => a2
+  ! On the device, 'p => a2' is now set.
+  call verify_a(a2, p)
+  !$acc end parallel
+  ! On the host, 'p => a1' persists.
+  call verify_a(a1, p)
+
+  !$acc parallel
+  ! On the device, 'p => a2' persists.
+  call verify_a(a2, p)
+  !$acc end parallel
+  ! On the host, 'p => a1' still persists.
+  call verify_a(a1, p)
+
+  p => a2
+
+  !$acc parallel
+  p => a1
+  ! On the device, 'p => a1' is now set.
+  call verify_a(a1, p)
+  !$acc end parallel
+  ! On the host, 'p => a2' persists.
+  call verify_a(a2, p)
+
+  !$acc parallel
+  ! On the device, 'p => a1' persists.
+  call verify_a(a1, p)
+  !$acc end parallel
+  ! On the host, 'p => a2' still persists.
+  call verify_a(a2, p)
+
+end program main