c-common.c (c_common_attribute_table): Handle "omp declare target link" attribute.

gcc/c-family/
	* c-common.c (c_common_attribute_table): Handle "omp declare target
	link" attribute.
gcc/
	* cgraphunit.c (output_in_order): Do not assemble "omp declare target
	link" variables in ACCEL_COMPILER.
	* gimplify.c (gimplify_adjust_omp_clauses): Do not remove mapping of
	"omp declare target link" variables.
	* omp-low.c (scan_sharing_clauses): Do not remove mapping of "omp
	declare target link" variables.
	(add_decls_addresses_to_decl_constructor): For "omp declare target link"
	variables output address of the artificial pointer instead of address of
	the variable.  Set most significant bit of the size to mark them.
	(pass_data_omp_target_link): New pass_data.
	(pass_omp_target_link): New class.
	(find_link_var_op): New static function.
	(make_pass_omp_target_link): New function.
	* passes.def: Add pass_omp_target_link.
	* tree-pass.h (make_pass_omp_target_link): Declare.
	* varpool.c (symbol_table::output_variables): Do not assemble "omp
	declare target link" variables in ACCEL_COMPILER.
gcc/lto/
	* lto.c: Include stringpool.h and fold-const.h.
	(offload_handle_link_vars): New static function.
	(lto_main): Call offload_handle_link_vars.
libgomp/
	* libgomp.h (REFCOUNT_LINK): Define.
	(struct splay_tree_key_s): Add link_key.
	* target.c (gomp_map_vars): Treat REFCOUNT_LINK objects as not mapped.
	Replace target address of the pointer with target address of newly
	mapped object in the splay tree.  Set link pointer on target to the
	device address of the mapped object.
	(gomp_unmap_vars): Restore target address of the pointer in the splay
	tree for REFCOUNT_LINK objects after unmapping.
	(gomp_load_image_to_device): Set refcount to REFCOUNT_LINK for "omp
	declare target link" objects.
	(gomp_unload_image_from_device): Replace j with i.  Force unmap of all
	"omp declare target link" objects, which were mapped for the image.
	(gomp_exit_data): Restore target address of the pointer in the splay
	tree for REFCOUNT_LINK objects after unmapping.
	* testsuite/libgomp.c/target-link-1.c: New file.

From-SVN: r231655

1 files changed, 123 insertions, 8 deletions

diff --git a/gcc/omp-low.c b/gcc/omp-low.c
index 5643480..676b1df 100644
--- a/gcc/omp-low.c
+++ b/gcc/omp-low.c
@@ -2026,7 +2026,8 @@ scan_sharing_clauses (tree clauses, omp_context *ctx,
 	  decl = OMP_CLAUSE_DECL (c);
 	  /* Global variables with "omp declare target" attribute
 	     don't need to be copied, the receiver side will use them
-	     directly.  */
+	     directly.  However, global variables with "omp declare target link"
+	     attribute need to be copied.  */
 	  if (OMP_CLAUSE_CODE (c) == OMP_CLAUSE_MAP
 	      && DECL_P (decl)
 	      && ((OMP_CLAUSE_MAP_KIND (c) != GOMP_MAP_FIRSTPRIVATE_POINTER
@@ -2034,7 +2035,9 @@ scan_sharing_clauses (tree clauses, omp_context *ctx,
 		       != GOMP_MAP_FIRSTPRIVATE_REFERENCE))
 		  || TREE_CODE (TREE_TYPE (decl)) == ARRAY_TYPE)
 	      && is_global_var (maybe_lookup_decl_in_outer_ctx (decl, ctx))
-	      && varpool_node::get_create (decl)->offloadable)
+	      && varpool_node::get_create (decl)->offloadable
+	      && !lookup_attribute ("omp declare target link",
+				    DECL_ATTRIBUTES (decl)))
 	    break;
 	  if (OMP_CLAUSE_CODE (c) == OMP_CLAUSE_MAP
 	      && OMP_CLAUSE_MAP_KIND (c) == GOMP_MAP_POINTER)
@@ -18588,13 +18591,45 @@ add_decls_addresses_to_decl_constructor (vec<tree, va_gc> *v_decls,
   for (unsigned i = 0; i < len; i++)
     {
       tree it = (*v_decls)[i];
-      bool is_function = TREE_CODE (it) != VAR_DECL;
+      bool is_var = TREE_CODE (it) == VAR_DECL;
+      bool is_link_var
+	= is_var
+#ifdef ACCEL_COMPILER
+	  && DECL_HAS_VALUE_EXPR_P (it)
+#endif
+	  && lookup_attribute ("omp declare target link", DECL_ATTRIBUTES (it));
 
-      CONSTRUCTOR_APPEND_ELT (v_ctor, NULL_TREE, build_fold_addr_expr (it));
-      if (!is_function)
-	CONSTRUCTOR_APPEND_ELT (v_ctor, NULL_TREE,
-				fold_convert (const_ptr_type_node,
-					      DECL_SIZE_UNIT (it)));
+      tree size = NULL_TREE;
+      if (is_var)
+	size = fold_convert (const_ptr_type_node, DECL_SIZE_UNIT (it));
+
+      tree addr;
+      if (!is_link_var)
+	addr = build_fold_addr_expr (it);
+      else
+	{
+#ifdef ACCEL_COMPILER
+	  /* For "omp declare target link" vars add address of the pointer to
+	     the target table, instead of address of the var.  */
+	  tree value_expr = DECL_VALUE_EXPR (it);
+	  tree link_ptr_decl = TREE_OPERAND (value_expr, 0);
+	  varpool_node::finalize_decl (link_ptr_decl);
+	  addr = build_fold_addr_expr (link_ptr_decl);
+#else
+	  addr = build_fold_addr_expr (it);
+#endif
+
+	  /* Most significant bit of the size marks "omp declare target link"
+	     vars in host and target tables.  */
+	  unsigned HOST_WIDE_INT isize = tree_to_uhwi (size);
+	  isize |= 1ULL << (int_size_in_bytes (const_ptr_type_node)
+			    * BITS_PER_UNIT - 1);
+	  size = wide_int_to_tree (const_ptr_type_node, isize);
+	}
+
+      CONSTRUCTOR_APPEND_ELT (v_ctor, NULL_TREE, addr);
+      if (is_var)
+	CONSTRUCTOR_APPEND_ELT (v_ctor, NULL_TREE, size);
     }
 }
 
@@ -19831,4 +19866,84 @@ make_pass_oacc_device_lower (gcc::context *ctxt)
   return new pass_oacc_device_lower (ctxt);
 }
 
+/* "omp declare target link" handling pass.  */
+
+namespace {
+
+const pass_data pass_data_omp_target_link =
+{
+  GIMPLE_PASS,			/* type */
+  "omptargetlink",		/* name */
+  OPTGROUP_NONE,		/* optinfo_flags */
+  TV_NONE,			/* tv_id */
+  PROP_ssa,			/* properties_required */
+  0,				/* properties_provided */
+  0,				/* properties_destroyed */
+  0,				/* todo_flags_start */
+  TODO_update_ssa,		/* todo_flags_finish */
+};
+
+class pass_omp_target_link : public gimple_opt_pass
+{
+public:
+  pass_omp_target_link (gcc::context *ctxt)
+    : gimple_opt_pass (pass_data_omp_target_link, ctxt)
+  {}
+
+  /* opt_pass methods: */
+  virtual bool gate (function *fun)
+    {
+#ifdef ACCEL_COMPILER
+      tree attrs = DECL_ATTRIBUTES (fun->decl);
+      return lookup_attribute ("omp declare target", attrs)
+	     || lookup_attribute ("omp target entrypoint", attrs);
+#else
+      (void) fun;
+      return false;
+#endif
+    }
+
+  virtual unsigned execute (function *);
+};
+
+/* Callback for walk_gimple_stmt used to scan for link var operands.  */
+
+static tree
+find_link_var_op (tree *tp, int *walk_subtrees, void *)
+{
+  tree t = *tp;
+
+  if (TREE_CODE (t) == VAR_DECL && DECL_HAS_VALUE_EXPR_P (t)
+      && lookup_attribute ("omp declare target link", DECL_ATTRIBUTES (t)))
+    {
+      *walk_subtrees = 0;
+      return t;
+    }
+
+  return NULL_TREE;
+}
+
+unsigned
+pass_omp_target_link::execute (function *fun)
+{
+  basic_block bb;
+  FOR_EACH_BB_FN (bb, fun)
+    {
+      gimple_stmt_iterator gsi;
+      for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
+	if (walk_gimple_stmt (&gsi, NULL, find_link_var_op, NULL))
+	  gimple_regimplify_operands (gsi_stmt (gsi), &gsi);
+    }
+
+  return 0;
+}
+
+} // anon namespace
+
+gimple_opt_pass *
+make_pass_omp_target_link (gcc::context *ctxt)
+{
+  return new pass_omp_target_link (ctxt);
+}
+
 #include "gt-omp-low.h"