diff mbox series

[08/14] OpenMP: Pointers and member mappings

Message ID c9312554aa15cd93c3e463f9dee84daccba31a67.1687201315.git.julian@codesourcery.com
State New
Headers show
Series OpenMP/OpenACC: map clause and OMP gimplify rework | expand

Commit Message

Julian Brown June 19, 2023, 9:17 p.m. UTC
This patch changes the mapping node arrangement used for array components
of derived types, e.g.:

  type T
  integer, pointer, dimension(:) :: arrptr
  end type T

  type(T) :: tvar
  [...]
  !$omp target map(tofrom: tvar%arrptr)

This will currently be mapped using three mapping nodes:

  GOMP_MAP_TO             tvar%arrptr       (the descriptor)
  GOMP_MAP_TOFROM         *tvar%arrptr%data (the actual array data)
  GOMP_MAP_ALWAYS_POINTER tvar%arrptr%data  (a pointer to the array data)

This follows OMP 5.0, 2.19.7.1 (or OpenMP 5.2, 5.8.3) "map Clause":

  "If a list item in a map clause is an associated pointer and the
   pointer is not the base pointer of another list item in a map clause
   on the same construct, then it is treated as if its pointer target
   is implicitly mapped in the same clause. For the purposes of the map
   clause, the mapped pointer target is treated as if its base pointer
   is the associated pointer."

However, we can also write this:

  map(to: tvar%arrptr) map(tofrom: tvar%arrptr(3:8))

and then instead we should follow (OpenMP 5.2, 5.8.3 "map Clause"):

  "For map clauses on map-entering constructs, if any list item has a base
   pointer for which a corresponding pointer exists in the data environment
   upon entry to the region and either a new list item or the corresponding
   pointer is created in the device data environment on entry to the region,
   then:
   1. [Fortran] The corresponding pointer variable is associated with
      a pointer target that has the same rank and bounds as the pointer
      target of the original pointer, such that the corresponding list item
      can be accessed through the pointer in a target region.
   2. The corresponding pointer variable becomes an attached pointer
      for the corresponding list item."

With this patch you can write the above mappings, and the mapping nodes
used to map pointers to array sections (with descriptors) now look
like this:

  1) map(to: tvar%arrptr)   -->
  GOMP_MAP_TO [implicit]  *tvar%arrptr%data  (the array data)
  GOMP_MAP_TO_PSET        tvar%arrptr        (the descriptor)
  GOMP_MAP_ATTACH_DETACH  tvar%arrptr%data

  2) map(tofrom: tvar%arrptr(3:8)   -->
  GOMP_MAP_TOFROM         *tvar%arrptr%data(3)  (size 8-3+1, etc.)
  GOMP_MAP_TO_PSET        tvar%arrptr
  GOMP_MAP_ATTACH_DETACH  tvar%arrptr%data      (bias 3, etc.)

In this case, we can determine in the front-end that the
whole-array/pointer mapping (1) is only needed to map the pointer --
so we drop it entirely.  (Note also that we set -- early -- the
OMP_CLAUSE_MAP_RUNTIME_IMPLICIT_P flag for whole-array-via-pointer
mappings. See below.)

In the middle end, we process mappings using the struct sibling-list
handling machinery by moving the "GOMP_MAP_TO_PSET" node from the middle
of the group of three mapping nodes to the proper sorted position after
the GOMP_MAP_STRUCT mapping:

  GOMP_MAP_STRUCT   tvar     (len: 1)
  GOMP_MAP_TO_PSET  tvar%arr (size: 64, etc.)  <--. moved here
  [...]                                           |
  GOMP_MAP_TOFROM         *tvar%arrptr%data(3) ___|
  GOMP_MAP_ATTACH_DETACH  tvar%arrptr%data

In another case, if we have an array of derived-type values "dtarr",
and mappings like:

  i = 1
  j = 1
  map(to: dtarr(i)%arrptr) map(tofrom: dtarr(j)%arrptr(3:8))

We still map the same way, but this time we cannot prove that the base
expressions "dtarr(i) and "dtarr(j)" are the same in the front-end.
So we keep both mappings, but we move the "[implicit]" mapping of the
full-array reference to the end of the clause list in gimplify.cc (by
adjusting the topological sorting algorithm):

  GOMP_MAP_STRUCT         dtvar  (len: 2)
  GOMP_MAP_TO_PSET        dtvar(i)%arrptr
  GOMP_MAP_TO_PSET        dtvar(j)%arrptr
  [...]
  GOMP_MAP_TOFROM         *dtvar(j)%arrptr%data(3)  (size: 8-3+1)
  GOMP_MAP_ATTACH_DETACH  dtvar(j)%arrptr%data
  GOMP_MAP_TO [implicit]  *dtvar(i)%arrptr%data(1)  (size: whole array)
  GOMP_MAP_ATTACH_DETACH  dtvar(i)%arrptr%data

Always moving "[implicit]" full-array mappings after array-section
mappings (without that bit set) means that we'll avoid copying the whole
array unnecessarily -- even in cases where we can't prove that the arrays
are the same.

The patch also fixes some bugs with "enter data" and "exit data"
directives with this new mapping arrangement.  Also now if you have
mappings like this:

  #pragma omp target enter data map(to: dv, dv%arr(1:20))

The whole of the derived-type variable "dv" is mapped, so the
GOMP_MAP_TO_PSET for the array-section mapping can be dropped:

  GOMP_MAP_TO            dv

  GOMP_MAP_TO            *dv%arr%data
  GOMP_MAP_TO_PSET       dv%arr <-- deleted (array section mapping)
  GOMP_MAP_ATTACH_DETACH dv%arr%data

To accommodate for recent changes to mapping nodes made by
Tobias, this version of the patch avoids using GOMP_MAP_TO_PSET
for "exit data" directives, in favour of using the "correct"
GOMP_MAP_RELEASE/GOMP_MAP_DELETE kinds during early expansion.

2023-06-16  Julian Brown  <julian@codesourcery.com>

gcc/fortran/
	* dependency.cc (gfc_omp_expr_prefix_same): New function.
	* dependency.h (gfc_omp_expr_prefix_same): Add prototype.
	* gfortran.h (gfc_omp_namelist): Add "duplicate_of" field to "u2"
	union.
	* trans-openmp.cc (dependency.h): Include.
	(gfc_trans_omp_array_section): Adjust mapping node arrangement for
	array descriptors.  Use GOMP_MAP_TO_PSET or
	GOMP_MAP_RELEASE/GOMP_MAP_DELETE with the OMP_CLAUSE_RELEASE_DESCRIPTOR
	flag set.
	(gfc_symbol_rooted_namelist): New function.
	(gfc_trans_omp_clauses): Check subcomponent and subarray/element
	accesses elsewhere in the clause list for pointers to derived types or
	array descriptors, and adjust or drop mapping nodes appropriately.
	Adjust for changes to mapping node arrangement.
	(gfc_trans_oacc_executable_directive): Pass code op through.

gcc/
	* gimplify.cc (omp_map_clause_descriptor_p): New function.
	(build_omp_struct_comp_nodes, omp_get_attachment, omp_group_base): Use
	above function.
	(omp_tsort_mapping_groups): Process nodes that have
	OMP_CLAUSE_MAP_RUNTIME_IMPLICIT_P set after those that don't.  Add
	enter_exit_data parameter.
	(omp_resolve_clause_dependencies): Remove GOMP_MAP_TO_PSET mappings if
	we're mapping the whole containing derived-type variable.
	(omp_accumulate_sibling_list): Adjust GOMP_MAP_TO_PSET handling.
	Remove GOMP_MAP_ALWAYS_POINTER handling.
	(gimplify_scan_omp_clauses): Pass enter_exit argument to
	omp_tsort_mapping_groups.  Don't adjust/remove GOMP_MAP_TO_PSET
	mappings for derived-type components here.
	* tree.h (OMP_CLAUSE_RELEASE_DESCRIPTOR): New macro.

gcc/testsuite/
	* gfortran.dg/gomp/map-9.f90: Adjust scan output.
	* gfortran.dg/gomp/map-subarray-2.f90: New test.
	* gfortran.dg/gomp/map-subarray.f90: New test.

libgomp/
	* testsuite/libgomp.fortran/map-subarray.f90: New test.
	* testsuite/libgomp.fortran/map-subarray-2.f90: New test.
	* testsuite/libgomp.fortran/map-subarray-3.f90: New test.
	* testsuite/libgomp.fortran/map-subarray-4.f90: New test.
	* testsuite/libgomp.fortran/map-subarray-6.f90: New test.
	* testsuite/libgomp.fortran/map-subarray-7.f90: New test.
	* testsuite/libgomp.fortran/map-subarray-8.f90: New test.
	* testsuite/libgomp.fortran/map-subcomponents.f90: New test.
	* testsuite/libgomp.fortran/struct-elem-map-1.f90: Adjust for
	descriptor-mapping changes.  Remove XFAIL.
---
 gcc/fortran/dependency.cc                     | 128 +++++++++
 gcc/fortran/dependency.h                      |   1 +
 gcc/fortran/gfortran.h                        |   1 +
 gcc/fortran/trans-openmp.cc                   | 260 +++++++++++++++---
 gcc/gimplify.cc                               | 161 ++++++++---
 gcc/testsuite/gfortran.dg/gomp/map-9.f90      |   2 +-
 .../gfortran.dg/gomp/map-subarray-2.f90       |  57 ++++
 .../gfortran.dg/gomp/map-subarray.f90         |  40 +++
 gcc/tree.h                                    |   4 +
 .../libgomp.fortran/map-subarray-2.f90        | 108 ++++++++
 .../libgomp.fortran/map-subarray-3.f90        |  62 +++++
 .../libgomp.fortran/map-subarray-4.f90        |  35 +++
 .../libgomp.fortran/map-subarray-6.f90        |  26 ++
 .../libgomp.fortran/map-subarray-7.f90        |  29 ++
 .../libgomp.fortran/map-subarray-8.f90        |  47 ++++
 .../libgomp.fortran/map-subarray.f90          |  33 +++
 .../libgomp.fortran/map-subcomponents.f90     |  32 +++
 .../libgomp.fortran/struct-elem-map-1.f90     | 183 +++++++++++-
 18 files changed, 1126 insertions(+), 83 deletions(-)
 create mode 100644 gcc/testsuite/gfortran.dg/gomp/map-subarray-2.f90
 create mode 100644 gcc/testsuite/gfortran.dg/gomp/map-subarray.f90
 create mode 100644 libgomp/testsuite/libgomp.fortran/map-subarray-2.f90
 create mode 100644 libgomp/testsuite/libgomp.fortran/map-subarray-3.f90
 create mode 100644 libgomp/testsuite/libgomp.fortran/map-subarray-4.f90
 create mode 100644 libgomp/testsuite/libgomp.fortran/map-subarray-6.f90
 create mode 100644 libgomp/testsuite/libgomp.fortran/map-subarray-7.f90
 create mode 100644 libgomp/testsuite/libgomp.fortran/map-subarray-8.f90
 create mode 100644 libgomp/testsuite/libgomp.fortran/map-subarray.f90
 create mode 100644 libgomp/testsuite/libgomp.fortran/map-subcomponents.f90
diff mbox series

Patch

diff --git a/gcc/fortran/dependency.cc b/gcc/fortran/dependency.cc
index 9117825ee6e..5c31044b4d3 100644
--- a/gcc/fortran/dependency.cc
+++ b/gcc/fortran/dependency.cc
@@ -2339,3 +2339,131 @@  gfc_dep_resolver (gfc_ref *lref, gfc_ref *rref, gfc_reverse *reverse,
 
   return fin_dep == GFC_DEP_OVERLAP;
 }
+
+/* Check if two refs are equal, for the purposes of checking if one might be
+   the base of the other for OpenMP (target directives).  Derived from
+   gfc_dep_resolver.  This function is stricter, e.g. indices arr(i) and
+   arr(j) compare as non-equal.  */
+
+bool
+gfc_omp_expr_prefix_same (gfc_expr *lexpr, gfc_expr *rexpr)
+{
+  gfc_ref *lref, *rref;
+
+  if (lexpr->symtree && rexpr->symtree)
+    {
+      /* See are_identical_variables above.  */
+      if (lexpr->symtree->n.sym->attr.dummy
+	  && rexpr->symtree->n.sym->attr.dummy)
+	{
+	  /* Dummy arguments: Only check for equal names.  */
+	  if (lexpr->symtree->n.sym->name != rexpr->symtree->n.sym->name)
+	    return false;
+	}
+      else
+	{
+	  if (lexpr->symtree->n.sym != rexpr->symtree->n.sym)
+	    return false;
+	}
+    }
+  else if (lexpr->base_expr && rexpr->base_expr)
+    {
+      if (gfc_dep_compare_expr (lexpr->base_expr, rexpr->base_expr) != 0)
+	return false;
+    }
+  else
+    return false;
+
+  lref = lexpr->ref;
+  rref = rexpr->ref;
+
+  while (lref && rref)
+    {
+      gfc_dependency fin_dep = GFC_DEP_EQUAL;
+
+      if (lref && lref->type == REF_COMPONENT && lref->u.c.component
+	  && strcmp (lref->u.c.component->name, "_data") == 0)
+	lref = lref->next;
+
+      if (rref && rref->type == REF_COMPONENT && rref->u.c.component
+	  && strcmp (rref->u.c.component->name, "_data") == 0)
+	rref = rref->next;
+
+      gcc_assert (lref->type == rref->type);
+
+      switch (lref->type)
+	{
+	case REF_COMPONENT:
+	  if (lref->u.c.component != rref->u.c.component)
+	    return false;
+	  break;
+
+	case REF_ARRAY:
+	  if (ref_same_as_full_array (lref, rref))
+	    break;
+	  if (ref_same_as_full_array (rref, lref))
+	    break;
+
+	  if (lref->u.ar.dimen != rref->u.ar.dimen)
+	    {
+	      if (lref->u.ar.type == AR_FULL
+		  && gfc_full_array_ref_p (rref, NULL))
+		break;
+	      if (rref->u.ar.type == AR_FULL
+		  && gfc_full_array_ref_p (lref, NULL))
+		break;
+	      return false;
+	    }
+
+	  for (int n = 0; n < lref->u.ar.dimen; n++)
+	    {
+	      if (lref->u.ar.dimen_type[n] == DIMEN_VECTOR
+		  && rref->u.ar.dimen_type[n] == DIMEN_VECTOR
+		  && gfc_dep_compare_expr (lref->u.ar.start[n],
+					   rref->u.ar.start[n]) == 0)
+		continue;
+	      if (lref->u.ar.dimen_type[n] == DIMEN_RANGE
+		  && rref->u.ar.dimen_type[n] == DIMEN_RANGE)
+		fin_dep = check_section_vs_section (&lref->u.ar, &rref->u.ar,
+						    n);
+	      else if (lref->u.ar.dimen_type[n] == DIMEN_ELEMENT
+		       && rref->u.ar.dimen_type[n] == DIMEN_RANGE)
+		fin_dep = gfc_check_element_vs_section (lref, rref, n);
+	      else if (rref->u.ar.dimen_type[n] == DIMEN_ELEMENT
+		       && lref->u.ar.dimen_type[n] == DIMEN_RANGE)
+		fin_dep = gfc_check_element_vs_section (rref, lref, n);
+	      else if (lref->u.ar.dimen_type[n] == DIMEN_ELEMENT
+		       && rref->u.ar.dimen_type[n] == DIMEN_ELEMENT)
+		{
+		  gfc_array_ref l_ar = lref->u.ar;
+		  gfc_array_ref r_ar = rref->u.ar;
+		  gfc_expr *l_start = l_ar.start[n];
+		  gfc_expr *r_start = r_ar.start[n];
+		  int i = gfc_dep_compare_expr (r_start, l_start);
+		  if (i == 0)
+		    fin_dep = GFC_DEP_EQUAL;
+		  else
+		    return false;
+		}
+	      else
+		return false;
+	      if (n + 1 < lref->u.ar.dimen
+		  && fin_dep != GFC_DEP_EQUAL)
+		return false;
+	    }
+
+	  if (fin_dep != GFC_DEP_EQUAL
+	      && fin_dep != GFC_DEP_OVERLAP)
+	    return false;
+
+	  break;
+
+	default:
+	  gcc_unreachable ();
+	}
+      lref = lref->next;
+      rref = rref->next;
+    }
+
+  return true;
+}
diff --git a/gcc/fortran/dependency.h b/gcc/fortran/dependency.h
index b1150316f5d..d5dffdd0bcb 100644
--- a/gcc/fortran/dependency.h
+++ b/gcc/fortran/dependency.h
@@ -40,5 +40,6 @@  int gfc_expr_is_one (gfc_expr *, int);
 int gfc_dep_resolver (gfc_ref *, gfc_ref *, gfc_reverse *,
 		      bool identical = false);
 int gfc_are_equivalenced_arrays (gfc_expr *, gfc_expr *);
+bool gfc_omp_expr_prefix_same (gfc_expr *, gfc_expr *);
 
 gfc_expr * gfc_discard_nops (gfc_expr *);
diff --git a/gcc/fortran/gfortran.h b/gcc/fortran/gfortran.h
index 9c8d88669a0..23afacd015e 100644
--- a/gcc/fortran/gfortran.h
+++ b/gcc/fortran/gfortran.h
@@ -1378,6 +1378,7 @@  typedef struct gfc_omp_namelist
     {
       struct gfc_omp_namelist_udr *udr;
       gfc_namespace *ns;
+      struct gfc_omp_namelist *duplicate_of;
     } u2;
   struct gfc_symbol *memspace_sym;
   struct gfc_symbol *traits_sym;
diff --git a/gcc/fortran/trans-openmp.cc b/gcc/fortran/trans-openmp.cc
index a055aa5a61a..a108f718ffa 100644
--- a/gcc/fortran/trans-openmp.cc
+++ b/gcc/fortran/trans-openmp.cc
@@ -49,6 +49,7 @@  along with GCC; see the file COPYING3.  If not see
 #include "stor-layout.h"
 #include "gimple-iterator.h"
 #include "gimplify-me.h"
+#include "dependency.h"
 
 #undef GCC_DIAG_STYLE
 #define GCC_DIAG_STYLE __gcc_tdiag__
@@ -3939,36 +3940,23 @@  gfc_trans_omp_array_section (stmtblock_t *block, gfc_exec_op op,
     }
   if (GFC_DESCRIPTOR_TYPE_P (TREE_TYPE (decl)))
     {
-      tree desc_node;
       tree type = TREE_TYPE (decl);
       ptr2 = gfc_conv_descriptor_data_get (decl);
-      desc_node = build_omp_clause (input_location, OMP_CLAUSE_MAP);
-      OMP_CLAUSE_DECL (desc_node) = decl;
-      OMP_CLAUSE_SIZE (desc_node) = TYPE_SIZE_UNIT (type);
-      if (OMP_CLAUSE_MAP_KIND (node) == GOMP_MAP_DELETE)
+      node2 = build_omp_clause (input_location, OMP_CLAUSE_MAP);
+      OMP_CLAUSE_DECL (node2) = decl;
+      OMP_CLAUSE_SIZE (node2) = TYPE_SIZE_UNIT (type);
+      if (OMP_CLAUSE_MAP_KIND (node) == GOMP_MAP_DELETE
+	  || OMP_CLAUSE_MAP_KIND (node) == GOMP_MAP_RELEASE
+	  || op == EXEC_OMP_TARGET_EXIT_DATA)
 	{
-	  OMP_CLAUSE_SET_MAP_KIND (desc_node, GOMP_MAP_DELETE);
-	  node2 = desc_node;
-	}
-      else if (OMP_CLAUSE_MAP_KIND (node) == GOMP_MAP_RELEASE
-	       || op == EXEC_OMP_TARGET_EXIT_DATA)
-	{
-	  OMP_CLAUSE_SET_MAP_KIND (desc_node, GOMP_MAP_RELEASE);
-	  node2 = desc_node;
-	}
-      else if (ptr_kind == GOMP_MAP_ALWAYS_POINTER)
-	{
-	  OMP_CLAUSE_SET_MAP_KIND (desc_node, GOMP_MAP_TO);
-	  node2 = node;
-	  node = desc_node;  /* Needs to come first.  */
+	  gomp_map_kind map_kind
+	    = (op == EXEC_OMP_TARGET_EXIT_DATA) ? GOMP_MAP_RELEASE
+						: OMP_CLAUSE_MAP_KIND (node);
+	  OMP_CLAUSE_SET_MAP_KIND (node2, map_kind);
+	  OMP_CLAUSE_RELEASE_DESCRIPTOR (node2) = 1;
 	}
       else
-	{
-	  OMP_CLAUSE_SET_MAP_KIND (desc_node, GOMP_MAP_TO_PSET);
-	  node2 = desc_node;
-	}
-      if (op == EXEC_OMP_TARGET_EXIT_DATA)
-	return;
+	OMP_CLAUSE_SET_MAP_KIND (node2, GOMP_MAP_TO_PSET);
       node3 = build_omp_clause (input_location, OMP_CLAUSE_MAP);
       OMP_CLAUSE_SET_MAP_KIND (node3, ptr_kind);
       OMP_CLAUSE_DECL (node3) = gfc_conv_descriptor_data_get (decl);
@@ -4072,6 +4060,73 @@  handle_iterator (gfc_namespace *ns, stmtblock_t *iter_block, tree block)
   return list;
 }
 
+/* To alleviate quadratic behaviour in checking each entry of a
+   gfc_omp_namelist against every other entry, we build a hashtable indexed by
+   gfc_symbol pointer, which we can use in the usual case that a map
+   expression has a symbol as its root term.  Return a namelist based on the
+   root symbol used by N, building a new table in SYM_ROOTED_NL using the
+   gfc_omp_namelist N2 (all clauses) if we haven't done so already.  */
+
+static gfc_omp_namelist *
+get_symbol_rooted_namelist (hash_map<gfc_symbol *,
+				     gfc_omp_namelist *> *&sym_rooted_nl,
+			    gfc_omp_namelist *n,
+			    gfc_omp_namelist *n2, bool *sym_based)
+{
+  /* Early-out if we have a NULL clause list (e.g. for OpenACC).  */
+  if (!n2)
+    return NULL;
+
+  gfc_symbol *use_sym = NULL;
+
+  /* We're only interested in cases where we have an expression, e.g. a
+     component access.  */
+  if (n->expr && n->expr->expr_type == EXPR_VARIABLE && n->expr->symtree)
+    use_sym = n->expr->symtree->n.sym;
+
+  *sym_based = false;
+
+  if (!use_sym)
+    return n2;
+
+  if (!sym_rooted_nl)
+    {
+      sym_rooted_nl = new hash_map<gfc_symbol *, gfc_omp_namelist *> ();
+
+      for (; n2 != NULL; n2 = n2->next)
+	{
+	  if (!n2->expr
+	      || n2->expr->expr_type != EXPR_VARIABLE
+	      || !n2->expr->symtree)
+	    continue;
+
+	  gfc_omp_namelist *nl_copy = gfc_get_omp_namelist ();
+	  memcpy (nl_copy, n2, sizeof *nl_copy);
+	  nl_copy->u2.duplicate_of = n2;
+	  nl_copy->next = NULL;
+
+	  gfc_symbol *idx_sym = n2->expr->symtree->n.sym;
+
+	  bool existed;
+	  gfc_omp_namelist *&entry
+	    = sym_rooted_nl->get_or_insert (idx_sym, &existed);
+	  if (existed)
+	    nl_copy->next = entry;
+	  entry = nl_copy;
+	}
+    }
+
+  gfc_omp_namelist **n2_sym = sym_rooted_nl->get (use_sym);
+
+  if (n2_sym)
+    {
+      *sym_based = true;
+      return *n2_sym;
+    }
+
+  return NULL;
+}
+
 static tree
 gfc_trans_omp_clauses (stmtblock_t *block, gfc_omp_clauses *clauses,
 		       locus where, bool declare_simd = false,
@@ -4089,6 +4144,8 @@  gfc_trans_omp_clauses (stmtblock_t *block, gfc_omp_clauses *clauses,
   if (clauses == NULL)
     return NULL_TREE;
 
+  hash_map<gfc_symbol *, gfc_omp_namelist *> *sym_rooted_nl = NULL;
+
   for (list = 0; list < OMP_LIST_NUM; list++)
     {
       gfc_omp_namelist *n = clauses->lists[list];
@@ -5202,6 +5259,54 @@  gfc_trans_omp_clauses (stmtblock_t *block, gfc_omp_clauses *clauses,
 			      goto finalize_map_clause;
 			    }
 
+			  gfc_omp_namelist *n2
+			    = openacc ? NULL : clauses->lists[OMP_LIST_MAP];
+
+			  bool sym_based;
+			  n2 = get_symbol_rooted_namelist (sym_rooted_nl, n,
+							   n2, &sym_based);
+
+			  /* If the last reference is a pointer to a derived
+			     type ("foo%dt_ptr"), check if any subcomponents
+			     of the same derived type member are being mapped
+			     elsewhere in the clause list ("foo%dt_ptr%x",
+			     etc.).  If we have such subcomponent mappings,
+			     we only create an ALLOC node for the pointer
+			     itself, and inhibit mapping the whole derived
+			     type.  */
+
+			  for (; n2 != NULL; n2 = n2->next)
+			    {
+			      if ((!sym_based && n == n2)
+				  || (sym_based && n == n2->u2.duplicate_of)
+				  || !n2->expr)
+				continue;
+
+			      if (!gfc_omp_expr_prefix_same (n->expr,
+							     n2->expr))
+				continue;
+
+			      gfc_ref *ref1 = n->expr->ref;
+			      gfc_ref *ref2 = n2->expr->ref;
+
+			      while (ref1->next && ref2->next)
+				{
+				  ref1 = ref1->next;
+				  ref2 = ref2->next;
+				}
+
+			      if (ref2->next)
+				{
+				  inner = build_fold_addr_expr (inner);
+				  OMP_CLAUSE_SET_MAP_KIND (node,
+							   GOMP_MAP_ALLOC);
+				  OMP_CLAUSE_DECL (node) = inner;
+				  OMP_CLAUSE_SIZE (node)
+				    = TYPE_SIZE_UNIT (TREE_TYPE (inner));
+				  goto finalize_map_clause;
+				}
+			    }
+
 			  tree data, size;
 
 			  if (lastref->u.c.component->ts.type == BT_CLASS)
@@ -5273,7 +5378,6 @@  gfc_trans_omp_clauses (stmtblock_t *block, gfc_omp_clauses *clauses,
 		      if (GFC_DESCRIPTOR_TYPE_P (TREE_TYPE (inner)))
 			{
 			  gomp_map_kind map_kind;
-			  tree desc_node;
 			  tree type = TREE_TYPE (inner);
 			  tree ptr = gfc_conv_descriptor_data_get (inner);
 			  ptr = build_fold_indirect_ref (ptr);
@@ -5316,21 +5420,19 @@  gfc_trans_omp_clauses (stmtblock_t *block, gfc_omp_clauses *clauses,
 			  OMP_CLAUSE_SIZE (node)
 			    = fold_build2 (MULT_EXPR, gfc_array_index_type,
 					   OMP_CLAUSE_SIZE (node), elemsz);
-			  desc_node = build_omp_clause (input_location,
-							OMP_CLAUSE_MAP);
-			  if (openacc)
-			    OMP_CLAUSE_SET_MAP_KIND (desc_node,
+			  node2 = build_omp_clause (input_location,
+						    OMP_CLAUSE_MAP);
+			  if (openacc
+			      || (map_kind != GOMP_MAP_RELEASE
+				  && map_kind != GOMP_MAP_DELETE))
+			    OMP_CLAUSE_SET_MAP_KIND (node2,
 						     GOMP_MAP_TO_PSET);
 			  else
-			    OMP_CLAUSE_SET_MAP_KIND (desc_node, map_kind);
-			  OMP_CLAUSE_DECL (desc_node) = inner;
-			  OMP_CLAUSE_SIZE (desc_node) = TYPE_SIZE_UNIT (type);
-			  if (openacc)
-			    node2 = desc_node;
-			  else
+			    OMP_CLAUSE_SET_MAP_KIND (node2, map_kind);
+			  OMP_CLAUSE_DECL (node2) = inner;
+			  OMP_CLAUSE_SIZE (node2) = TYPE_SIZE_UNIT (type);
+			  if (!openacc)
 			    {
-			      node2 = node;
-			      node = desc_node;  /* Put first.  */
 			      if (n->expr->ts.type == BT_DERIVED
 				  && n->expr->ts.u.derived->attr.alloc_comp)
 				{
@@ -5338,18 +5440,73 @@  gfc_trans_omp_clauses (stmtblock_t *block, gfc_omp_clauses *clauses,
 				     in gfc_omp_deep_mapping{,_p,_cnt}; force
 				     evaluate to ensure that it is
 				     not gimplified + is a decl.  */
-				  tree tmp = OMP_CLAUSE_SIZE (node2);
+				  tree tmp = OMP_CLAUSE_SIZE (node);
 				  tree var = gfc_create_var (TREE_TYPE (tmp),
 							     NULL);
 				  gfc_add_modify_loc (input_location, block,
 						      var, tmp);
-				  OMP_CLAUSE_SIZE (node2) = var;
+				  OMP_CLAUSE_SIZE (node) = var;
 				  gfc_allocate_lang_decl (var);
 				  GFC_DECL_SAVED_DESCRIPTOR (var) = inner;
 				}
+
+			      gfc_omp_namelist *n2
+				= clauses->lists[OMP_LIST_MAP];
+
+			      /* If we don't have a mapping of a smaller part
+				 of the array -- or we can't prove that we do
+				 statically -- set this flag.  If there is a
+				 mapping of a smaller part of the array after
+				 all, this will turn into a no-op at
+				 runtime.  */
+			      OMP_CLAUSE_MAP_RUNTIME_IMPLICIT_P (node) = 1;
+
+			      bool sym_based;
+			      n2 = get_symbol_rooted_namelist (sym_rooted_nl,
+							       n, n2,
+							       &sym_based);
+
+			      bool drop_mapping = false;
+
+			      for (; n2 != NULL; n2 = n2->next)
+				{
+				  if ((!sym_based && n == n2)
+				      || (sym_based && n == n2->u2.duplicate_of)
+				      || !n2->expr)
+				    continue;
+
+				  if (!gfc_omp_expr_prefix_same (n->expr,
+								 n2->expr))
+				    continue;
+
+				  gfc_ref *ref1 = n->expr->ref;
+				  gfc_ref *ref2 = n2->expr->ref;
+
+				  /* We know ref1 and ref2 overlap.  We're
+				     interested in whether ref2 describes a
+				     smaller part of the array than ref1, which
+				     we already know refers to the full
+				     array.  */
+
+				  while (ref1->next && ref2->next)
+				    {
+				      ref1 = ref1->next;
+				      ref2 = ref2->next;
+				    }
+
+				  if (ref2->next
+				      || (ref2->type == REF_ARRAY
+					  && (ref2->u.ar.type == AR_ELEMENT
+					      || (ref2->u.ar.type
+						  == AR_SECTION))))
+				    {
+				      drop_mapping = true;
+				      break;
+				    }
+				}
+			      if (drop_mapping)
+				continue;
 			    }
-			  if (op == EXEC_OMP_TARGET_EXIT_DATA)
-			    goto finalize_map_clause;
 			  node3 = build_omp_clause (input_location,
 						    OMP_CLAUSE_MAP);
 			  OMP_CLAUSE_SET_MAP_KIND (node3,
@@ -5527,6 +5684,23 @@  gfc_trans_omp_clauses (stmtblock_t *block, gfc_omp_clauses *clauses,
 	}
     }
 
+  /* Free hashmap if we built it.  */
+  if (sym_rooted_nl)
+    {
+      typedef hash_map<gfc_symbol *, gfc_omp_namelist *>::iterator hti;
+      for (hti it = sym_rooted_nl->begin (); it != sym_rooted_nl->end (); ++it)
+	{
+	  gfc_omp_namelist *&nl = (*it).second;
+	  while (nl)
+	    {
+	      gfc_omp_namelist *next = nl->next;
+	      free (nl);
+	      nl = next;
+	    }
+	}
+      delete sym_rooted_nl;
+    }
+
   if (clauses->if_expr)
     {
       tree if_var;
@@ -6397,7 +6571,7 @@  gfc_trans_oacc_executable_directive (gfc_code *code)
 
   gfc_start_block (&block);
   oacc_clauses = gfc_trans_omp_clauses (&block, clauses, code->loc,
-					false, true);
+					false, true, code->op);
   stmt = build1_loc (input_location, construct_code, void_type_node, 
 		     oacc_clauses);
   gfc_add_expr_to_block (&block, stmt);
diff --git a/gcc/gimplify.cc b/gcc/gimplify.cc
index 6a43c792450..da81582da1c 100644
--- a/gcc/gimplify.cc
+++ b/gcc/gimplify.cc
@@ -8865,6 +8865,25 @@  gimplify_omp_depend (tree *list_p, gimple_seq *pre_p)
   return 1;
 }
 
+/* True if mapping node C maps, or unmaps, a (Fortran) array descriptor.  */
+
+static bool
+omp_map_clause_descriptor_p (tree c)
+{
+  if (OMP_CLAUSE_CODE (c) != OMP_CLAUSE_MAP)
+    return false;
+
+  if (OMP_CLAUSE_MAP_KIND (c) == GOMP_MAP_TO_PSET)
+    return true;
+
+  if ((OMP_CLAUSE_MAP_KIND (c) == GOMP_MAP_RELEASE
+       || OMP_CLAUSE_MAP_KIND (c) == GOMP_MAP_DELETE)
+      && OMP_CLAUSE_RELEASE_DESCRIPTOR (c))
+    return true;
+
+  return false;
+}
+
 /* For a set of mappings describing an array section pointed to by a struct
    (or derived type, etc.) component, create an "alloc" or "release" node to
    insert into a list following a GOMP_MAP_STRUCT node.  For some types of
@@ -8900,9 +8919,7 @@  build_omp_struct_comp_nodes (enum tree_code code, tree grp_start, tree grp_end,
   if (OMP_CLAUSE_CHAIN (grp_start) != grp_end)
     grp_mid = OMP_CLAUSE_CHAIN (grp_start);
 
-  if (grp_mid
-      && OMP_CLAUSE_CODE (grp_mid) == OMP_CLAUSE_MAP
-      && OMP_CLAUSE_MAP_KIND (grp_mid) == GOMP_MAP_TO_PSET)
+  if (grp_mid && omp_map_clause_descriptor_p (grp_mid))
     OMP_CLAUSE_SIZE (c2) = OMP_CLAUSE_SIZE (grp_mid);
   else
     OMP_CLAUSE_SIZE (c2) = TYPE_SIZE_UNIT (ptr_type_node);
@@ -9088,7 +9105,7 @@  omp_get_attachment (omp_mapping_group *grp)
 	return NULL_TREE;
 
       node = OMP_CLAUSE_CHAIN (node);
-      if (node && OMP_CLAUSE_MAP_KIND (node) == GOMP_MAP_TO_PSET)
+      if (node && omp_map_clause_descriptor_p (node))
 	{
 	  gcc_assert (node != grp->grp_end);
 	  node = OMP_CLAUSE_CHAIN (node);
@@ -9181,7 +9198,7 @@  omp_group_last (tree *start_p)
 		 || (OMP_CLAUSE_MAP_KIND (nc)
 		     == GOMP_MAP_ATTACH_ZERO_LENGTH_ARRAY_SECTION)
 		 || OMP_CLAUSE_MAP_KIND (nc) == GOMP_MAP_ALWAYS_POINTER
-		 || OMP_CLAUSE_MAP_KIND (nc) == GOMP_MAP_TO_PSET))
+		 || omp_map_clause_descriptor_p (nc)))
 	{
 	  grp_last_p = &OMP_CLAUSE_CHAIN (c);
 	  c = nc;
@@ -9337,32 +9354,31 @@  omp_group_base (omp_mapping_group *grp, unsigned int *chained,
 	return node;
 
       node = OMP_CLAUSE_CHAIN (node);
-      if (node && OMP_CLAUSE_MAP_KIND (node) == GOMP_MAP_TO_PSET)
+      if (!node)
+	internal_error ("unexpected mapping node");
+      if (omp_map_clause_descriptor_p (node))
 	{
 	  if (node == grp->grp_end)
 	    return *grp->grp_start;
 	  node = OMP_CLAUSE_CHAIN (node);
 	}
-      if (node)
-	switch (OMP_CLAUSE_MAP_KIND (node))
-	  {
-	  case GOMP_MAP_POINTER:
-	  case GOMP_MAP_FIRSTPRIVATE_POINTER:
-	  case GOMP_MAP_FIRSTPRIVATE_REFERENCE:
-	  case GOMP_MAP_POINTER_TO_ZERO_LENGTH_ARRAY_SECTION:
-	    *firstprivate = OMP_CLAUSE_DECL (node);
-	    return *grp->grp_start;
+      switch (OMP_CLAUSE_MAP_KIND (node))
+	{
+	case GOMP_MAP_POINTER:
+	case GOMP_MAP_FIRSTPRIVATE_POINTER:
+	case GOMP_MAP_FIRSTPRIVATE_REFERENCE:
+	case GOMP_MAP_POINTER_TO_ZERO_LENGTH_ARRAY_SECTION:
+	  *firstprivate = OMP_CLAUSE_DECL (node);
+	  return *grp->grp_start;
 
-	  case GOMP_MAP_ALWAYS_POINTER:
-	  case GOMP_MAP_ATTACH_DETACH:
-	  case GOMP_MAP_ATTACH_ZERO_LENGTH_ARRAY_SECTION:
-	    return *grp->grp_start;
+	case GOMP_MAP_ALWAYS_POINTER:
+	case GOMP_MAP_ATTACH_DETACH:
+	case GOMP_MAP_ATTACH_ZERO_LENGTH_ARRAY_SECTION:
+	  return *grp->grp_start;
 
-	  default:
-	    internal_error ("unexpected mapping node");
-	  }
-      else
-	internal_error ("unexpected mapping node");
+	default:
+	  internal_error ("unexpected mapping node");
+	}
       return error_mark_node;
 
     case GOMP_MAP_TO_PSET:
@@ -9712,18 +9728,45 @@  omp_tsort_mapping_groups_1 (omp_mapping_group ***outlist,
 static omp_mapping_group *
 omp_tsort_mapping_groups (vec<omp_mapping_group> *groups,
 			  hash_map<tree_operand_hash_no_se, omp_mapping_group *>
-			    *grpmap)
+			    *grpmap,
+			  bool enter_exit_data)
 {
   omp_mapping_group *grp, *outlist = NULL, **cursor;
   unsigned int i;
+  bool saw_runtime_implicit = false;
 
   cursor = &outlist;
 
   FOR_EACH_VEC_ELT (*groups, i, grp)
     {
       if (grp->mark != PERMANENT)
-	if (!omp_tsort_mapping_groups_1 (&cursor, groups, grpmap, grp))
-	  return NULL;
+	{
+	  if (OMP_CLAUSE_MAP_RUNTIME_IMPLICIT_P (*grp->grp_start))
+	    {
+	      saw_runtime_implicit = true;
+	      continue;
+	    }
+	  if (!omp_tsort_mapping_groups_1 (&cursor, groups, grpmap, grp))
+	    return NULL;
+	}
+    }
+
+  if (!saw_runtime_implicit)
+    return outlist;
+
+  FOR_EACH_VEC_ELT (*groups, i, grp)
+    {
+      if (grp->mark != PERMANENT
+	  && OMP_CLAUSE_MAP_RUNTIME_IMPLICIT_P (*grp->grp_start))
+	{
+	  /* Clear the flag for enter/exit data because it is currently
+	     meaningless for those operations in libgomp.  */
+	  if (enter_exit_data)
+	    OMP_CLAUSE_MAP_RUNTIME_IMPLICIT_P (*grp->grp_start) = 0;
+
+	  if (!omp_tsort_mapping_groups_1 (&cursor, groups, grpmap, grp))
+	    return NULL;
+	}
     }
 
   return outlist;
@@ -10126,6 +10169,11 @@  omp_check_mapping_compatibility (location_t loc,
    mapping.  However, if we have a reference to pointer, make other appropriate
    adjustments to the mapping nodes instead.
 
+   If we have an ATTACH_DETACH node with a Fortran pointer-set (array
+   descriptor) mapping for a derived-type component, and we're also mapping the
+   whole of the derived-type variable on another clause, the pointer-set
+   mapping is removed.
+
    If we have a component access but we're also mapping the whole of the
    containing struct, drop the former access.
 
@@ -10305,6 +10353,17 @@  omp_resolve_clause_dependencies (enum tree_code code,
 		   GOMP_MAP_ATTACH_ZLAS for it.  */
 		if (!base_mapped_to && referenced_ptr_node)
 		  OMP_CLAUSE_SET_MAP_KIND (referenced_ptr_node, zlas_kind);
+
+		omp_mapping_group *struct_group;
+		tree desc;
+		if ((desc = OMP_CLAUSE_CHAIN (*grp->grp_start))
+		    && omp_map_clause_descriptor_p (desc)
+		    && omp_mapped_by_containing_struct (grpmap, decl,
+							&struct_group))
+		  /* If we have a pointer set but we're mapping (or unmapping)
+		     the whole of the containing struct, we can remove the
+		     pointer set mapping.  */
+		  OMP_CLAUSE_CHAIN (*grp->grp_start) = OMP_CLAUSE_CHAIN (desc);
 	      }
 	    else if (TREE_CODE (TREE_TYPE (base_ptr)) == REFERENCE_TYPE
 		     && (TREE_CODE (TREE_TYPE (TREE_TYPE (base_ptr)))
@@ -10752,11 +10811,17 @@  omp_accumulate_sibling_list (enum omp_region_type region_type,
      for the purposes of gathering sibling lists, etc.  */
   /* gcc_assert (base == addr_tokens[base_token]->expr);  */
 
-  bool ptr = (OMP_CLAUSE_MAP_KIND (grp_end) == GOMP_MAP_ALWAYS_POINTER);
   bool attach_detach = ((OMP_CLAUSE_MAP_KIND (grp_end)
 			 == GOMP_MAP_ATTACH_DETACH)
 			|| (OMP_CLAUSE_MAP_KIND (grp_end)
 			    == GOMP_MAP_ATTACH_ZERO_LENGTH_ARRAY_SECTION));
+  bool has_descriptor = false;
+  if (OMP_CLAUSE_CHAIN (*grp_start_p) != grp_end)
+    {
+      tree grp_mid = OMP_CLAUSE_CHAIN (*grp_start_p);
+      if (grp_mid && omp_map_clause_descriptor_p (grp_mid))
+	has_descriptor = true;
+    }
 
   if (!struct_map_to_clause || struct_map_to_clause->get (base) == NULL)
     {
@@ -10779,7 +10844,18 @@  omp_accumulate_sibling_list (enum omp_region_type region_type,
 	 GOMP_MAP_STRUCT into the middle of the old one.  */
       tree *insert_node_pos = reprocessing_struct ? *added_tail : grp_start_p;
 
-      if (ptr || attach_detach)
+      if (has_descriptor)
+	{
+	  tree desc = OMP_CLAUSE_CHAIN (*grp_start_p);
+	  if (code == OMP_TARGET_EXIT_DATA || code == OACC_EXIT_DATA)
+	    OMP_CLAUSE_SET_MAP_KIND (desc, GOMP_MAP_RELEASE);
+	  tree sc = *insert_node_pos;
+	  OMP_CLAUSE_CHAIN (l) = desc;
+	  OMP_CLAUSE_CHAIN (*grp_start_p) = OMP_CLAUSE_CHAIN (desc);
+	  OMP_CLAUSE_CHAIN (desc) = sc;
+	  *insert_node_pos = l;
+	}
+      else if (attach_detach)
 	{
 	  tree extra_node;
 	  tree alloc_node
@@ -11010,7 +11086,7 @@  omp_accumulate_sibling_list (enum omp_region_type region_type,
 	  || OMP_CLAUSE_MAP_KIND (*sc) == GOMP_MAP_ATTACH_DETACH)
 	sc = &OMP_CLAUSE_CHAIN (*sc);
       for (i = 0; i < elems; i++, sc = &OMP_CLAUSE_CHAIN (*sc))
-	if ((ptr || attach_detach) && sc == grp_start_p)
+	if (attach_detach && sc == grp_start_p)
 	  break;
 	else if (TREE_CODE (OMP_CLAUSE_DECL (*sc)) != COMPONENT_REF
 		 && TREE_CODE (OMP_CLAUSE_DECL (*sc)) != INDIRECT_REF
@@ -11066,7 +11142,7 @@  omp_accumulate_sibling_list (enum omp_region_type region_type,
 		|| (known_eq (coffset, offset)
 		    && maybe_lt (cbitpos, bitpos)))
 	      {
-		if (ptr || attach_detach)
+		if (attach_detach)
 		  scp = sc;
 		else
 		  break;
@@ -11082,7 +11158,9 @@  omp_accumulate_sibling_list (enum omp_region_type region_type,
 	     the list manipulation below.  We only need to handle the (pointer
 	     or reference) attach/detach case.  */
 	  tree extra_node, alloc_node;
-	  if (attach_detach)
+	  if (has_descriptor)
+	    gcc_unreachable ();
+	  else if (attach_detach)
 	    alloc_node = build_omp_struct_comp_nodes (code, *grp_start_p,
 						      grp_end, &extra_node);
 	  else
@@ -11115,7 +11193,17 @@  omp_accumulate_sibling_list (enum omp_region_type region_type,
 	  return NULL;
 	}
 
-      if (ptr || attach_detach)
+      if (has_descriptor)
+	{
+	  tree desc = OMP_CLAUSE_CHAIN (*grp_start_p);
+	  if (code == OMP_TARGET_EXIT_DATA
+	      || code == OACC_EXIT_DATA)
+	    OMP_CLAUSE_SET_MAP_KIND (desc, GOMP_MAP_RELEASE);
+	  omp_siblist_move_node_after (desc,
+				       &OMP_CLAUSE_CHAIN (*grp_start_p),
+				       scp ? scp : sc);
+	}
+      else if (attach_detach)
 	{
 	  tree cl = NULL_TREE, extra_node;
 	  tree alloc_node = build_omp_struct_comp_nodes (code, *grp_start_p,
@@ -11260,8 +11348,7 @@  omp_build_struct_sibling_lists (enum tree_code code,
 	     as a struct (the GOMP_MAP_POINTER following will have the form
 	     "var.data", but such mappings are handled specially).  */
 	  tree grpmid = OMP_CLAUSE_CHAIN (*grp_start_p);
-	  if (OMP_CLAUSE_CODE (grpmid) == OMP_CLAUSE_MAP
-	      && OMP_CLAUSE_MAP_KIND (grpmid) == GOMP_MAP_TO_PSET
+	  if (omp_map_clause_descriptor_p (grpmid)
 	      && DECL_P (OMP_CLAUSE_DECL (grpmid)))
 	    continue;
 	}
@@ -11537,6 +11624,8 @@  gimplify_scan_omp_clauses (tree *list_p, gimple_seq *pre_p,
 					  list_p);
 
 	  omp_mapping_group *outlist = NULL;
+	  bool enter_exit = (code == OMP_TARGET_ENTER_DATA
+			     || code == OMP_TARGET_EXIT_DATA);
 
 	  /* Topological sorting may fail if we have duplicate nodes, which
 	     we should have detected and shown an error for already.  Skip
@@ -11551,7 +11640,7 @@  gimplify_scan_omp_clauses (tree *list_p, gimple_seq *pre_p,
 	  groups = omp_gather_mapping_groups (list_p);
 	  grpmap = omp_index_mapping_groups (groups);
 
-	  outlist = omp_tsort_mapping_groups (groups, grpmap);
+	  outlist = omp_tsort_mapping_groups (groups, grpmap, enter_exit);
 	  outlist = omp_segregate_mapping_groups (outlist);
 	  list_p = omp_reorder_mapping_groups (groups, outlist, list_p);
 
diff --git a/gcc/testsuite/gfortran.dg/gomp/map-9.f90 b/gcc/testsuite/gfortran.dg/gomp/map-9.f90
index f930a49d9ff..8c8d4f7c57c 100644
--- a/gcc/testsuite/gfortran.dg/gomp/map-9.f90
+++ b/gcc/testsuite/gfortran.dg/gomp/map-9.f90
@@ -2,7 +2,7 @@ 
 
 ! PR fortran/108545
 
-! { dg-final { scan-tree-dump "#pragma omp target enter data map\\(struct:x \\\[len: 1\\\]\\) map\\(always,to:x\.a \\\[len: \[0-9\]+\\\]\\) map\\(to:MEM <integer\\(kind=4\\)\\\[0:\\\]> \\\[\\(integer\\(kind=4\\)\\\[0:\\\] \\*\\)_\[0-9\]+] \\\[len: _\[0-9\]+\\\]\\) map\\(attach:x\.a\.data \\\[bias: 0\\\]\\)" "omplower" } }
+! { dg-final { scan-tree-dump "#pragma omp target enter data map\\(struct:x \\\[len: 1\\\]\\) map\\(to:x\.a \\\[pointer set, len: \[0-9\]+\\\]\\) map\\(to:MEM <integer\\(kind=4\\)\\\[0:\\\]> \\\[\\(integer\\(kind=4\\)\\\[0:\\\] \\*\\)_\[0-9\]+] \\\[len: _\[0-9\]+\\\]\\) map\\(attach:x\.a\.data \\\[bias: 0\\\]\\)" "omplower" } }
 
 program p
    type t
diff --git a/gcc/testsuite/gfortran.dg/gomp/map-subarray-2.f90 b/gcc/testsuite/gfortran.dg/gomp/map-subarray-2.f90
new file mode 100644
index 00000000000..5aaaf53e697
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/gomp/map-subarray-2.f90
@@ -0,0 +1,57 @@ 
+! { dg-do compile }
+! { dg-additional-options "-fdump-tree-gimple" }
+
+type T
+integer, pointer :: arr1(:)
+integer, pointer :: arr2(:)
+integer, pointer :: arr3(:)
+integer, pointer :: arr4(:)
+end type T
+
+type(T) :: tv
+integer, allocatable, target, dimension(:) :: arr
+
+allocate(arr(1:20))
+
+tv%arr1 => arr
+tv%arr2 => arr
+tv%arr3 => arr
+tv%arr4 => arr
+
+!$omp target enter data map(to: tv%arr1)
+
+! { dg-final { scan-tree-dump {(?n)#pragma omp target enter data map\(struct:tv \[len: 1\]\) map\(to:tv\.arr1 \[pointer set, len: [0-9]+\]\) map\(to:MEM <integer\(kind=4\)\[0:\]> \[\(integer\(kind=4\)\[0:\] \*\)_[0-9]+\] \[len: _[0-9]+\]\) map\(attach:tv\.arr1\.data \[bias: 0\]\)} "gimple" } }
+
+!$omp target exit data map(from: tv%arr1)
+
+! { dg-final { scan-tree-dump {(?n)#pragma omp target exit data map\(from:MEM <integer\(kind=4\)\[0:\]> \[\(integer\(kind=4\)\[0:\] \*\)_[0-9]+\] \[len: _[0-9]+\]\) map\(release:tv\.arr1 \[len: [0-9]+\]\) map\(detach:tv\.arr1\.data \[bias: 0\]\)} "gimple" } }
+
+
+!$omp target enter data map(to: tv%arr2) map(to: tv%arr2(1:10))
+
+! { dg-final { scan-tree-dump {(?n)#pragma omp target enter data map\(struct:tv \[len: 1\]\) map\(to:tv\.arr2 \[pointer set, len: [0-9]+\]\) map\(to:MEM <integer\(kind=4\)\[0:\]> \[\(integer\(kind=4\)\[0:\] \*\)_[0-9]+\] \[len: _[0-9]+\]\) map\(attach:tv\.arr2\.data \[bias: [^\]]+\]\)} "gimple" } }
+
+!$omp target exit data map(from: tv%arr2) map(from: tv%arr2(1:10))
+
+! { dg-final { scan-tree-dump {(?n)#pragma omp target exit data map\(release:tv\.arr2 \[len: [0-9]+\]\) map\(from:MEM <integer\(kind=4\)\[0:\]> \[\(integer\(kind=4\)\[0:\] \*\)_[0-9]+\] \[len: _[0-9]+\]\) map\(detach:tv\.arr2\.data \[bias: [^\]]+\]\)} "gimple" } }
+
+
+!$omp target enter data map(to: tv, tv%arr3(1:10))
+
+! { dg-final { scan-tree-dump {(?n)#pragma omp target enter data map\(to:tv \[len: [0-9]+\]\) map\(to:MEM <integer\(kind=4\)\[0:\]> \[\(integer\(kind=4\)\[0:\] \*\)_[0-9]+\] \[len: _[0-9]+\]\) map\(attach:tv\.arr3\.data \[bias: [^\]]+\]\)} "gimple" } }
+
+!$omp target exit data map(from: tv, tv%arr3(1:10))
+
+! { dg-final { scan-tree-dump {(?n)#pragma omp target exit data map\(from:tv \[len: [0-9]+\]\) map\(from:MEM <integer\(kind=4\)\[0:\]> \[\(integer\(kind=4\)\[0:\] \*\)[_[0-9]+\] \[len: _[0-9]+\]\) map\(detach:tv\.arr3\.data \[bias: [^\]]+\]\)} "gimple" } }
+
+
+!$omp target enter data map(to: tv%arr4(1:10))
+
+! { dg-final { scan-tree-dump {(?n)#pragma omp target enter data map\(struct:tv \[len: 1\]\) map\(to:tv\.arr4 \[pointer set, len: [0-9]+\]\) map\(to:MEM <integer\(kind=4\)\[0:\]> \[\(integer\(kind=4\)\[0:\] \*\)_[0-9]+\] \[len: _[0-9]+\]\) map\(attach:tv\.arr4\.data \[bias: [^\]]+\]\)} "gimple" } }
+
+!$omp target exit data map(from: tv%arr4(1:10))
+
+! { dg-final { scan-tree-dump {(?n)#pragma omp target exit data map\(release:tv\.arr4 \[len: [0-9]+\]\) map\(from:MEM <integer\(kind=4\)\[0:\]> \[\(integer\(kind=4\)\[0:\] \*\)_[0-9]+\] \[len: _[0-9]+\]\) map\(detach:tv\.arr4\.data \[bias: [^\]]+\]\)} "gimple" } }
+
+end
+
diff --git a/gcc/testsuite/gfortran.dg/gomp/map-subarray.f90 b/gcc/testsuite/gfortran.dg/gomp/map-subarray.f90
new file mode 100644
index 00000000000..197888a4336
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/gomp/map-subarray.f90
@@ -0,0 +1,40 @@ 
+! { dg-do compile }
+! { dg-additional-options "-fdump-tree-gimple" }
+
+type T
+integer, pointer :: arr1(:)
+integer, pointer :: arr2(:)
+end type T
+
+type(T) :: tv
+integer, allocatable, target, dimension(:) :: arr
+
+allocate(arr(1:20))
+
+tv%arr1 => arr
+tv%arr2 => arr
+
+!$omp target map(tv%arr1)
+tv%arr1(1) = tv%arr1(1) + 1
+!$omp end target
+
+! { dg-final { scan-tree-dump {(?n)#pragma omp target.* map\(struct:tv \[len: 1\]\) map\(to:tv\.arr1 \[pointer set, len: [0-9]+\]\) map\(tofrom:MEM <integer\(kind=4\)\[0:\]> \[\(integer\(kind=4\)\[0:\] \*\)_[0-9]+\] \[len: _[0-9]+\]\[implicit\]\) map\(attach:tv\.arr1\.data \[bias: 0\]\)} "gimple" } }
+
+!$omp target map(tv%arr2) map(tv%arr2(1:10))
+tv%arr2(1) = tv%arr2(1) + 1
+!$omp end target
+
+!$omp target map(tv%arr2(1:10))
+tv%arr2(1) = tv%arr2(1) + 1
+!$omp end target
+
+! { dg-final { scan-tree-dump-times {(?n)#pragma omp target.* map\(struct:tv \[len: 1\]\) map\(to:tv\.arr2 \[pointer set, len: [0-9]+\]\) map\(tofrom:MEM <integer\(kind=4\)\[0:\]> \[\(integer\(kind=4\)\[0:\] \*\)_[0-9]+\] \[len: _[0-9]+\]\) map\(attach:tv\.arr2\.data \[bias: [^\]]+\]\)} 2 "gimple" } }
+
+!$omp target map(tv, tv%arr2(1:10))
+tv%arr2(1) = tv%arr2(1) + 1
+!$omp end target
+
+! { dg-final { scan-tree-dump {(?n)#pragma omp target.* map\(tofrom:tv \[len: [0-9]+\]\) map\(tofrom:MEM <integer\(kind=4\)\[0:\]> \[\(integer\(kind=4\)\[0:\] \*\)_[0-9]+\] \[len: _[0-9]+\]\) map\(attach:tv\.arr2\.data \[bias: [^\]]+\]\)} "gimple" } }
+
+end
+
diff --git a/gcc/tree.h b/gcc/tree.h
index 58f2e2e20cb..8e2e3654b56 100644
--- a/gcc/tree.h
+++ b/gcc/tree.h
@@ -1797,6 +1797,10 @@  class auto_suppress_location_wrappers
    same directive.  */
 #define OMP_CLAUSE_ATTACHMENT_MAPPING_ERASED(NODE) \
   TREE_STATIC (OMP_CLAUSE_SUBCODE_CHECK (NODE, OMP_CLAUSE_MAP))
+/* Nonzero if this is an attach/detach that is indirect, i.e. not applied to
+   a structure member.  */
+#define OMP_CLAUSE_RELEASE_DESCRIPTOR(NODE) \
+  TREE_NOTHROW (OMP_CLAUSE_SUBCODE_CHECK (NODE, OMP_CLAUSE_MAP))
 
 /* Flag that 'OMP_CLAUSE_DECL (NODE)' is to be made addressable during OMP
    lowering.  */
diff --git a/libgomp/testsuite/libgomp.fortran/map-subarray-2.f90 b/libgomp/testsuite/libgomp.fortran/map-subarray-2.f90
new file mode 100644
index 00000000000..02f08c52a8c
--- /dev/null
+++ b/libgomp/testsuite/libgomp.fortran/map-subarray-2.f90
@@ -0,0 +1,108 @@ 
+! { dg-do run }
+
+program myprog
+type u
+  integer, dimension (:), pointer :: tarr1
+  integer, dimension (:), pointer :: tarr2
+  integer, dimension (:), pointer :: tarr3
+end type u
+
+type(u) :: myu1, myu2, myu3
+
+integer, dimension (12), target :: myarray1
+integer, dimension (12), target :: myarray2
+integer, dimension (12), target :: myarray3
+integer, dimension (12), target :: myarray4
+integer, dimension (12), target :: myarray5
+integer, dimension (12), target :: myarray6
+integer, dimension (12), target :: myarray7
+integer, dimension (12), target :: myarray8
+integer, dimension (12), target :: myarray9
+
+myu1%tarr1 => myarray1
+myu1%tarr2 => myarray2
+myu1%tarr3 => myarray3
+myu2%tarr1 => myarray4
+myu2%tarr2 => myarray5
+myu2%tarr3 => myarray6
+myu3%tarr1 => myarray7
+myu3%tarr2 => myarray8
+myu3%tarr3 => myarray9
+
+myu1%tarr1 = 0
+myu1%tarr2 = 0
+myu1%tarr3 = 0
+myu2%tarr1 = 0
+myu2%tarr2 = 0
+myu2%tarr3 = 0
+myu3%tarr1 = 0
+myu3%tarr2 = 0
+myu3%tarr3 = 0
+
+!$omp target map(to:myu1%tarr1) map(tofrom:myu1%tarr1(:)) &
+!$omp&       map(to:myu1%tarr2) map(tofrom:myu1%tarr2(:)) &
+!$omp&       map(to:myu1%tarr3) map(tofrom:myu1%tarr3(:)) &
+!$omp&       map(to:myu2%tarr1) map(tofrom:myu2%tarr1(:)) &
+!$omp&       map(to:myu2%tarr2) map(tofrom:myu2%tarr2(:)) &
+!$omp&       map(to:myu2%tarr3) map(tofrom:myu2%tarr3(:)) &
+!$omp&       map(to:myu3%tarr1) map(tofrom:myu3%tarr1(:)) &
+!$omp&       map(to:myu3%tarr2) map(tofrom:myu3%tarr2(:)) &
+!$omp&       map(to:myu3%tarr3) map(tofrom:myu3%tarr3(:))
+myu1%tarr1(1) = myu1%tarr1(1) + 1
+myu2%tarr1(1) = myu2%tarr1(1) + 1
+myu3%tarr1(1) = myu3%tarr1(1) + 1
+!$omp end target
+
+!$omp target map(to:myu1%tarr1) map(tofrom:myu1%tarr1(1:2)) &
+!$omp&       map(to:myu1%tarr2) map(tofrom:myu1%tarr2(1:2)) &
+!$omp&       map(to:myu1%tarr3) map(tofrom:myu1%tarr3(1:2)) &
+!$omp&       map(to:myu2%tarr1) map(tofrom:myu2%tarr1(1:2)) &
+!$omp&       map(to:myu2%tarr2) map(tofrom:myu2%tarr2(1:2)) &
+!$omp&       map(to:myu2%tarr3) map(tofrom:myu2%tarr3(1:2)) &
+!$omp&       map(to:myu3%tarr1) map(tofrom:myu3%tarr1(1:2)) &
+!$omp&       map(to:myu3%tarr2) map(tofrom:myu3%tarr2(1:2)) &
+!$omp&       map(to:myu3%tarr3) map(tofrom:myu3%tarr3(1:2))
+myu1%tarr2(1) = myu1%tarr2(1) + 1
+myu2%tarr2(1) = myu2%tarr2(1) + 1
+myu3%tarr2(1) = myu3%tarr2(1) + 1
+!$omp end target
+
+!$omp target map(to:myu1%tarr1) map(tofrom:myu1%tarr1(1)) &
+!$omp&       map(to:myu1%tarr2) map(tofrom:myu1%tarr2(1)) &
+!$omp&       map(to:myu1%tarr3) map(tofrom:myu1%tarr3(1)) &
+!$omp&       map(to:myu2%tarr1) map(tofrom:myu2%tarr1(1)) &
+!$omp&       map(to:myu2%tarr2) map(tofrom:myu2%tarr2(1)) &
+!$omp&       map(to:myu2%tarr3) map(tofrom:myu2%tarr3(1)) &
+!$omp&       map(to:myu3%tarr1) map(tofrom:myu3%tarr1(1)) &
+!$omp&       map(to:myu3%tarr2) map(tofrom:myu3%tarr2(1)) &
+!$omp&       map(to:myu3%tarr3) map(tofrom:myu3%tarr3(1))
+myu1%tarr3(1) = myu1%tarr3(1) + 1
+myu2%tarr3(1) = myu2%tarr3(1) + 1
+myu3%tarr3(1) = myu3%tarr3(1) + 1
+!$omp end target
+
+!$omp target map(tofrom:myu1%tarr1) &
+!$omp&       map(tofrom:myu1%tarr2) &
+!$omp&       map(tofrom:myu1%tarr3) &
+!$omp&       map(tofrom:myu2%tarr1) &
+!$omp&       map(tofrom:myu2%tarr2) &
+!$omp&       map(tofrom:myu2%tarr3) &
+!$omp&       map(tofrom:myu3%tarr1) &
+!$omp&       map(tofrom:myu3%tarr2) &
+!$omp&       map(tofrom:myu3%tarr3)
+myu1%tarr2(1) = myu1%tarr2(1) + 1
+myu2%tarr2(1) = myu2%tarr2(1) + 1
+myu3%tarr2(1) = myu3%tarr2(1) + 1
+!$omp end target
+
+if (myu1%tarr1(1).ne.1) stop 1
+if (myu2%tarr1(1).ne.1) stop 2
+if (myu3%tarr1(1).ne.1) stop 3
+if (myu1%tarr2(1).ne.2) stop 4
+if (myu2%tarr2(1).ne.2) stop 5
+if (myu3%tarr2(1).ne.2) stop 6
+if (myu1%tarr3(1).ne.1) stop 7
+if (myu2%tarr3(1).ne.1) stop 8
+if (myu3%tarr3(1).ne.1) stop 9
+
+end program myprog
diff --git a/libgomp/testsuite/libgomp.fortran/map-subarray-3.f90 b/libgomp/testsuite/libgomp.fortran/map-subarray-3.f90
new file mode 100644
index 00000000000..318e77ea44f
--- /dev/null
+++ b/libgomp/testsuite/libgomp.fortran/map-subarray-3.f90
@@ -0,0 +1,62 @@ 
+! { dg-do run }
+
+module mymod
+type G
+integer :: x, y
+integer, pointer :: arr(:)
+integer :: z
+end type G
+end module mymod
+
+program myprog
+use mymod
+
+integer, target :: arr1(10)
+integer, target :: arr2(10)
+integer, target :: arr3(10)
+type(G), dimension(3) :: gvar
+
+integer :: i, j
+
+gvar(1)%arr => arr1
+gvar(2)%arr => arr2
+gvar(3)%arr => arr3
+
+gvar(1)%arr = 0
+gvar(2)%arr = 0
+gvar(3)%arr = 0
+
+i = 1
+j = 1
+
+! Here 'gvar(i)' and 'gvar(j)' are the same element, so this should work.
+! This generates a whole-array mapping for gvar(i)%arr, but with the
+! "runtime implicit" bit set so the smaller subarray gvar(j)%arr(1:5) takes
+! precedence.
+
+!$omp target map(gvar(i)%arr, gvar(j)%arr(1:5))
+gvar(i)%arr(1) = gvar(i)%arr(1) + 1
+gvar(j)%arr(1) = gvar(j)%arr(1) + 2
+!$omp end target
+
+!$omp target map(gvar(i)%arr(1:5), gvar(j)%arr)
+gvar(i)%arr(1) = gvar(i)%arr(1) + 3
+gvar(j)%arr(1) = gvar(j)%arr(1) + 4
+!$omp end target
+
+! For these ones, we know the array index is the same, so we can just
+! drop the whole-array mapping.
+
+!$omp target map(gvar(i)%arr, gvar(i)%arr(1:5))
+gvar(i)%arr(1) = gvar(i)%arr(1) + 1
+gvar(i)%arr(1) = gvar(j)%arr(1) + 2
+!$omp end target
+
+!$omp target map(gvar(i)%arr(1:5), gvar(i)%arr)
+gvar(i)%arr(1) = gvar(i)%arr(1) + 3
+gvar(i)%arr(1) = gvar(j)%arr(1) + 4
+!$omp end target
+
+if (gvar(1)%arr(1).ne.20) stop 1
+
+end program myprog
diff --git a/libgomp/testsuite/libgomp.fortran/map-subarray-4.f90 b/libgomp/testsuite/libgomp.fortran/map-subarray-4.f90
new file mode 100644
index 00000000000..5d15808f0da
--- /dev/null
+++ b/libgomp/testsuite/libgomp.fortran/map-subarray-4.f90
@@ -0,0 +1,35 @@ 
+! { dg-do run }
+
+type t
+  integer, pointer :: p(:)
+end type t
+
+type(t) :: var(2)
+
+allocate (var(1)%p, source=[1,2,3,5])
+allocate (var(2)%p, source=[2,3,5])
+
+!$omp target map(var(1)%p, var(2)%p)
+var(1)%p(1) = 5
+var(2)%p(2) = 7
+!$omp end target
+
+!$omp target map(var(1)%p(1:3), var(1)%p, var(2)%p)
+var(1)%p(1) = var(1)%p(1) + 1
+var(2)%p(2) = var(2)%p(2) + 1
+!$omp end target
+
+!$omp target map(var(1)%p, var(2)%p, var(2)%p(1:3))
+var(1)%p(1) = var(1)%p(1) + 1
+var(2)%p(2) = var(2)%p(2) + 1
+!$omp end target
+
+!$omp target map(var(1)%p, var(1)%p(1:3), var(2)%p, var(2)%p(2))
+var(1)%p(1) = var(1)%p(1) + 1
+var(2)%p(2) = var(2)%p(2) + 1
+!$omp end target
+
+if (var(1)%p(1).ne.8) stop 1
+if (var(2)%p(2).ne.10) stop 2
+
+end
diff --git a/libgomp/testsuite/libgomp.fortran/map-subarray-6.f90 b/libgomp/testsuite/libgomp.fortran/map-subarray-6.f90
new file mode 100644
index 00000000000..9f0edf70890
--- /dev/null
+++ b/libgomp/testsuite/libgomp.fortran/map-subarray-6.f90
@@ -0,0 +1,26 @@ 
+! { dg-do run }
+
+type t
+  integer, pointer :: p(:)
+  integer, pointer :: p2(:)
+end type t
+
+type(t) :: var
+integer, target :: tgt(5), tgt2(1000)
+var%p => tgt
+var%p2 => tgt2
+
+p = 0
+p2 = 0
+
+!$omp target map(tgt, tgt2(4:6), var)
+  var%p(1) = 5
+  var%p2(5) = 7
+!$omp end target
+
+if (var%p(1).ne.5) stop 1
+if (var%p2(5).ne.7) stop 2
+
+end
+
+! { dg-shouldfail "" { offload_device_nonshared_as } }
diff --git a/libgomp/testsuite/libgomp.fortran/map-subarray-7.f90 b/libgomp/testsuite/libgomp.fortran/map-subarray-7.f90
new file mode 100644
index 00000000000..42da7296106
--- /dev/null
+++ b/libgomp/testsuite/libgomp.fortran/map-subarray-7.f90
@@ -0,0 +1,29 @@ 
+type t
+integer, pointer :: p2(:)
+end type t
+
+integer, target :: A(5)
+integer, pointer :: p(:), p2(:)
+type(t) :: var
+
+allocate(p2(1:20))
+p => A
+var%p2 => p2
+
+A = 0
+p2 = 0
+
+! These arrays "share original storage", so are unsupported.  This will
+! (correctly) fail with a non-shared address space.
+
+!$omp target map(A(3:4), p2(4:8), p, var%p2)
+A(3) = A(3) + 1
+p2(4) = p2(4) + 2
+!$omp end target
+
+if (A(3).ne.1) stop 1
+if (p2(4).ne.2) stop 2
+
+end program
+
+! { dg-shouldfail "" { offload_device_nonshared_as } }
diff --git a/libgomp/testsuite/libgomp.fortran/map-subarray-8.f90 b/libgomp/testsuite/libgomp.fortran/map-subarray-8.f90
new file mode 100644
index 00000000000..a47360e10ec
--- /dev/null
+++ b/libgomp/testsuite/libgomp.fortran/map-subarray-8.f90
@@ -0,0 +1,47 @@ 
+! { dg-do run }
+
+type F
+integer, pointer :: mem(:)
+end type F
+
+type(F) :: fv
+integer, allocatable, target :: arr(:)
+
+allocate(arr(1:20))
+
+fv%mem => arr
+fv%mem = 0
+
+!$omp target enter data map(to: fv%mem(1:10))
+!$omp target map(alloc: fv%mem)
+fv%mem(1) = fv%mem(1) + 1
+!$omp end target
+!$omp target exit data map(from: fv%mem(1:10))
+
+if (fv%mem(1).ne.1) stop 1
+
+!$omp target enter data map(to: fv, fv%mem(1:10))
+!$omp target
+fv%mem(1) = fv%mem(1) + 1
+!$omp end target
+!$omp target exit data map(from: fv, fv%mem(1:10))
+
+if (fv%mem(1).ne.2) stop 2
+
+!$omp target enter data map(to: fv%mem, fv%mem(1:10))
+!$omp target
+fv%mem(1) = fv%mem(1) + 1
+!$omp end target
+!$omp target exit data map(from: fv%mem, fv%mem(1:10))
+
+if (fv%mem(1).ne.3) stop 3
+
+!$omp target enter data map(to: fv%mem)
+!$omp target
+fv%mem(1) = fv%mem(1) + 1
+!$omp end target
+!$omp target exit data map(from: fv%mem)
+
+if (fv%mem(1).ne.4) stop 4
+
+end
diff --git a/libgomp/testsuite/libgomp.fortran/map-subarray.f90 b/libgomp/testsuite/libgomp.fortran/map-subarray.f90
new file mode 100644
index 00000000000..85f5af3a2a6
--- /dev/null
+++ b/libgomp/testsuite/libgomp.fortran/map-subarray.f90
@@ -0,0 +1,33 @@ 
+! { dg-do run }
+
+program myprog
+type u
+  integer, dimension (:), pointer :: tarr
+end type u
+
+type(u) :: myu
+integer, dimension (12), target :: myarray
+
+myu%tarr => myarray
+
+myu%tarr = 0
+
+!$omp target map(to:myu%tarr) map(tofrom:myu%tarr(:))
+myu%tarr(1) = myu%tarr(1) + 1
+!$omp end target
+
+!$omp target map(to:myu%tarr) map(tofrom:myu%tarr(1:2))
+myu%tarr(1) = myu%tarr(1) + 1
+!$omp end target
+
+!$omp target map(to:myu%tarr) map(tofrom:myu%tarr(1))
+myu%tarr(1) = myu%tarr(1) + 1
+!$omp end target
+
+!$omp target map(tofrom:myu%tarr)
+myu%tarr(1) = myu%tarr(1) + 1
+!$omp end target
+
+if (myu%tarr(1).ne.4) stop 1
+
+end program myprog
diff --git a/libgomp/testsuite/libgomp.fortran/map-subcomponents.f90 b/libgomp/testsuite/libgomp.fortran/map-subcomponents.f90
new file mode 100644
index 00000000000..c7f90131cba
--- /dev/null
+++ b/libgomp/testsuite/libgomp.fortran/map-subcomponents.f90
@@ -0,0 +1,32 @@ 
+! { dg-do run }
+
+module mymod
+type F
+integer :: a, b, c
+integer, dimension(10) :: d
+end type F
+
+type G
+integer :: x, y
+type(F), pointer :: myf
+integer :: z
+end type G
+end module mymod
+
+program myprog
+use mymod
+
+type(F), target :: ftmp
+type(G) :: gvar
+
+gvar%myf => ftmp
+
+gvar%myf%d = 0
+
+!$omp target map(to:gvar%myf) map(tofrom: gvar%myf%b, gvar%myf%d)
+gvar%myf%d(1) = gvar%myf%d(1) + 1
+!$omp end target
+
+if (gvar%myf%d(1).ne.1) stop 1
+
+end program myprog
diff --git a/libgomp/testsuite/libgomp.fortran/struct-elem-map-1.f90 b/libgomp/testsuite/libgomp.fortran/struct-elem-map-1.f90
index 7f3d8174f97..b1d696656c0 100644
--- a/libgomp/testsuite/libgomp.fortran/struct-elem-map-1.f90
+++ b/libgomp/testsuite/libgomp.fortran/struct-elem-map-1.f90
@@ -36,6 +36,10 @@  program main
   call six ()
   call seven ()
   call eight ()
+  call nine ()
+  call ten ()
+  call eleven ()
+  call twelve ()
 
 contains
   ! Implicitly mapped – but no pointers are mapped
@@ -408,7 +412,180 @@  contains
     !$omp end target
   end subroutine eight
 
-end program main
+  ! This is "subroutine four" but with explicit base-pointer mappings
+  ! (var%f, etc.).
+  subroutine nine()
+    type(t2) :: var
 
-! Fixed by the "Fortran pointers and member mappings" patch
-! { dg-xfail-run-if TODO { offload_device_nonshared_as } }
+    print '(g0)', '==== TESTCASE "nine" ===='
+
+    var = t2(a = 1, &
+             b = 2, c = cmplx(-1.0_8, 2.0_8,kind=8), &
+             d = [(-3*i, i = 1, 10)], &
+             str1 = "abcde", &
+             str2 = ["12345", "67890", "ABCDE", "FGHIJ"], &
+             uni1 = 4_"abcde", &
+             uni2 = [4_"12345", 4_"67890", 4_"ABCDE", 4_"FGHIJ"])
+    allocate (var%f, source=[22, 33, 44, 55])
+    allocate (var%str4, source=["Let's", "Go!!!"])
+    allocate (var%uni4, source=[4_"Let's", 4_"Go!!!"])
+
+!   !$omp target map(tofrom: var%d(4:7), var%f(2:3), var%str2(2:3)) &
+!   !$omp&       map(tofrom: var%str4(2:2), var%uni2(2:3), var%uni4(2:2))
+    !$omp target map(to: var%f) map(tofrom: var%d(4:7), var%f(2:3), &
+    !$omp&       var%str2(2:3), var%uni2(2:3))
+      if (any (var%d(4:7) /= [(-3*i, i = 4, 7)])) stop 4
+      if (any (var%str2(2:3) /= ["67890", "ABCDE"])) stop 6
+
+      if (.not. associated (var%f)) stop 9
+      if (size (var%f) /= 4) stop 10
+      if (any (var%f(2:3) /= [33, 44])) stop 11
+!     if (.not. associated (var%str4)) stop 15
+!     if (len (var%str4) /= 5) stop 16
+!     if (size (var%str4) /= 2) stop 17
+!     if (var%str4(2) /= "Go!!!") stop 18
+
+      if (any (var%uni2(2:3) /= [4_"67890", 4_"ABCDE"])) stop 19
+!     if (.not. associated (var%uni4)) stop 20
+!     if (len (var%uni4) /= 5) stop 21
+!     if (size (var%uni4) /= 2) stop 22
+!     if (var%uni4(2) /= "Go!!!") stop 23
+    !$omp end target
+
+    deallocate(var%f, var%str4)
+  end subroutine nine
+
+  ! This is "subroutine five" but with explicit base-pointer mappings.
+  subroutine ten()
+    type(t2) :: var
+
+    print '(g0)', '==== TESTCASE "ten" ===='
+
+    var = t2(a = 1, &
+             b = 2, c = cmplx(-1.0_8, 2.0_8,kind=8), &
+             d = [(-3*i, i = 1, 10)], &
+             str1 = "abcde", &
+             str2 = ["12345", "67890", "ABCDE", "FGHIJ"], &
+             uni1 = 4_"abcde", &
+             uni2 = [4_"12345", 4_"67890", 4_"ABCDE", 4_"FGHIJ"])
+    allocate (var%f, source=[22, 33, 44, 55])
+    allocate (var%str4, source=["Let's", "Go!!!"])
+
+    !$omp target map(tofrom: var%d(4:7))
+      if (any (var%d(4:7) /= [(-3*i, i = 4, 7)])) stop 4
+    !$omp end target
+    !$omp target map(tofrom: var%str2(2:3))
+      if (any (var%str2(2:3) /= ["67890", "ABCDE"])) stop 6
+    !$omp end target
+
+    !$omp target map(to: var%f) map(tofrom: var%f(2:3))
+     if (.not. associated (var%f)) stop 9
+     if (size (var%f) /= 4) stop 10
+     if (any (var%f(2:3) /= [33, 44])) stop 11
+    !$omp end target
+!  !$omp target map(tofrom: var%str4(2:2))
+!     if (.not. associated (var%str4)) stop 15
+!     if (len (var%str4) /= 5) stop 16
+!     if (size (var%str4) /= 2) stop 17
+!     if (var%str4(2) /= "Go!!!") stop 18
+!   !$omp end target
+!  !$omp target map(tofrom: var%uni4(2:2))
+!     if (.not. associated (var%uni4)) stop 15
+!     if (len (var%uni4) /= 5) stop 16
+!     if (size (var%uni4) /= 2) stop 17
+!     if (var%uni4(2) /= 4_"Go!!!") stop 18
+!  !$omp end target
+
+    deallocate(var%f, var%str4)
+  end subroutine ten
+
+  ! This is "subroutine six" but with explicit base pointer mappings.
+  subroutine eleven()
+    type(t2) :: var
+
+    print '(g0)', '==== TESTCASE "eleven" ===='
+
+    var = t2(a = 1, &
+             b = 2, c = cmplx(-1.0_8, 2.0_8,kind=8), &
+             d = [(-3*i, i = 1, 10)], &
+             str1 = "abcde", &
+             str2 = ["12345", "67890", "ABCDE", "FGHIJ"], &
+             uni1 = 4_"abcde", &
+             uni2 = [4_"12345", 4_"67890", 4_"ABCDE", 4_"FGHIJ"])
+    allocate (var%f, source=[22, 33, 44, 55])
+    allocate (var%str4, source=["Let's", "Go!!!"])
+    allocate (var%uni4, source=[4_"Let's", 4_"Go!!!"])
+
+!   !$omp target map(tofrom: var%d(5), var%f(3), var%str2(3), &
+!   !$omp                    var%str4(2), var%uni2(3), var%uni4(2))
+    !$omp target map(to: var%f) map(tofrom: var%d(5), var%f(3), &
+    !$omp&                                  var%str2(3), var%uni2(3))
+      if (var%d(5) /= -3*5) stop 4
+      if (var%str2(3) /= "ABCDE") stop 6
+      if (var%uni2(3) /= 4_"ABCDE") stop 7
+
+     if (.not. associated (var%f)) stop 9
+     if (size (var%f) /= 4) stop 10
+     if (var%f(3) /= 44) stop 11
+!     if (.not. associated (var%str4)) stop 15
+!     if (len (var%str4) /= 5) stop 16
+!     if (size (var%str4) /= 2) stop 17
+!     if (var%str4(2) /= "Go!!!") stop 18
+!     if (.not. associated (var%uni4)) stop 19
+!     if (len (var%uni4) /= 5) stop 20
+!     if (size (var%uni4) /= 2) stop 21
+!     if (var%uni4(2) /= 4_"Go!!!") stop 22
+    !$omp end target
+
+    deallocate(var%f, var%str4, var%uni4)
+  end subroutine eleven
+
+  ! This is "subroutine seven" but with explicit base-pointer mappings.
+  subroutine twelve()
+    type(t2) :: var
+
+    print '(g0)', '==== TESTCASE "twelve" ===='
+
+    var = t2(a = 1, &
+             b = 2, c = cmplx(-1.0_8, 2.0_8,kind=8), &
+             d = [(-3*i, i = 1, 10)], &
+             str1 = "abcde", &
+             str2 = ["12345", "67890", "ABCDE", "FGHIJ"], &
+             uni1 = 4_"abcde", &
+             uni2 = [4_"12345", 4_"67890", 4_"ABCDE", 4_"FGHIJ"])
+    allocate (var%f, source=[22, 33, 44, 55])
+    allocate (var%str4, source=["Let's", "Go!!!"])
+    allocate (var%uni4, source=[4_"Let's", 4_"Go!!!"])
+
+    !$omp target map(tofrom: var%d(5))
+      if (var%d(5) /= (-3*5)) stop 4
+    !$omp end target
+    !$omp target map(tofrom: var%str2(2:3))
+      if (any (var%str2(2:3) /= ["67890", "ABCDE"])) stop 6
+    !$omp end target
+    !$omp target map(tofrom: var%uni2(2:3))
+      if (any (var%uni2(2:3) /= [4_"67890", 4_"ABCDE"])) stop 7
+    !$omp end target
+
+    !$omp target map(to: var%f) map(tofrom: var%f(2:3))
+     if (.not. associated (var%f)) stop 9
+     if (size (var%f) /= 4) stop 10
+     if (any (var%f(2:3) /= [33, 44])) stop 11
+    !$omp end target
+!   !$omp target map(tofrom: var%str4(2:2))
+!     if (.not. associated (var%str4)) stop 15
+!     if (len (var%str4) /= 5) stop 16
+!     if (size (var%str4) /= 2) stop 17
+!     if (var%str4(2) /= "Go!!!") stop 18
+!   !$omp end target
+!   !$omp target map(tofrom: var%uni4(2:2))
+!     if (.not. associated (var%uni4)) stop 15
+!     if (len (var%uni4) /= 5) stop 16
+!     if (size (var%uni4) /= 2) stop 17
+!     if (var%uni4(2) /= 4_"Go!!!") stop 18
+!   !$omp end target
+
+    deallocate(var%f, var%str4, var%uni4)
+  end subroutine twelve
+
+end program main