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

11 files changed, 210 insertions, 9 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 69fe3a7..02c2117 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,23 @@
+2015-12-15  Ilya Verbin  <ilya.verbin@intel.com>
+
+	* 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.
+
 2015-12-15  Bernd Schmidt  <bschmidt@redhat.com>
 
 	PR middle-end/21273
diff --git a/gcc/c-family/ChangeLog b/gcc/c-family/ChangeLog
index db9a279..525cc16 100644
--- a/gcc/c-family/ChangeLog
+++ b/gcc/c-family/ChangeLog
@@ -1,3 +1,8 @@
+2015-12-15  Ilya Verbin  <ilya.verbin@intel.com>
+
+	* c-common.c (c_common_attribute_table): Handle "omp declare target
+	link" attribute.
+
 2015-12-14  Jakub Jelinek  <jakub@redhat.com>
 
 	PR c/68833
diff --git a/gcc/c-family/c-common.c b/gcc/c-family/c-common.c
index 9bc02fc..4250cdf 100644
--- a/gcc/c-family/c-common.c
+++ b/gcc/c-family/c-common.c
@@ -821,6 +821,8 @@ const struct attribute_spec c_common_attribute_table[] =
 			      handle_simd_attribute, false },
   { "omp declare target",     0, 0, true, false, false,
 			      handle_omp_declare_target_attribute, false },
+  { "omp declare target link", 0, 0, true, false, false,
+			      handle_omp_declare_target_attribute, false },
   { "alloc_align",	      1, 1, false, true, true,
 			      handle_alloc_align_attribute, false },
   { "assume_aligned",	      1, 2, false, true, true,
diff --git a/gcc/cgraphunit.c b/gcc/cgraphunit.c
index 3d86c36..8443cb0 100644
--- a/gcc/cgraphunit.c
+++ b/gcc/cgraphunit.c
@@ -2210,6 +2210,13 @@ output_in_order (bool no_reorder)
 	  break;
 
 	case ORDER_VAR:
+#ifdef ACCEL_COMPILER
+	  /* Do not assemble "omp declare target link" vars.  */
+	  if (DECL_HAS_VALUE_EXPR_P (nodes[i].u.v->decl)
+	      && lookup_attribute ("omp declare target link",
+				   DECL_ATTRIBUTES (nodes[i].u.v->decl)))
+	    break;
+#endif
 	  nodes[i].u.v->assemble_decl ();
 	  break;
 
diff --git a/gcc/gimplify.c b/gcc/gimplify.c
index 80c6bf2..438efba 100644
--- a/gcc/gimplify.c
+++ b/gcc/gimplify.c
@@ -7910,7 +7910,9 @@ gimplify_adjust_omp_clauses (gimple_seq *pre_p, gimple_seq body, tree *list_p,
 	  n = splay_tree_lookup (ctx->variables, (splay_tree_key) decl);
 	  if ((ctx->region_type & ORT_TARGET) != 0
 	      && !(n->value & GOVD_SEEN)
-	      && GOMP_MAP_ALWAYS_P (OMP_CLAUSE_MAP_KIND (c)) == 0)
+	      && GOMP_MAP_ALWAYS_P (OMP_CLAUSE_MAP_KIND (c)) == 0
+	      && !lookup_attribute ("omp declare target link",
+				    DECL_ATTRIBUTES (decl)))
 	    {
 	      remove = true;
 	      /* For struct element mapping, if struct is never referenced
diff --git a/gcc/lto/ChangeLog b/gcc/lto/ChangeLog
index 6e90527..ac20a3f 100644
--- a/gcc/lto/ChangeLog
+++ b/gcc/lto/ChangeLog
@@ -1,3 +1,9 @@
+2015-12-15  Ilya Verbin  <ilya.verbin@intel.com>
+
+	* lto.c: Include stringpool.h and fold-const.h.
+	(offload_handle_link_vars): New static function.
+	(lto_main): Call offload_handle_link_vars.
+
 2015-12-10  Jan Hubicka  <hubicka@ucw.cz>
 
 	* lto.c (lto_read_in_decl_state): Unpickle compressed bit.
diff --git a/gcc/lto/lto.c b/gcc/lto/lto.c
index fcf7caf..5fd50dc 100644
--- a/gcc/lto/lto.c
+++ b/gcc/lto/lto.c
@@ -50,6 +50,8 @@ along with GCC; see the file COPYING3.  If not see
 #include "ipa-utils.h"
 #include "gomp-constants.h"
 #include "lto-symtab.h"
+#include "stringpool.h"
+#include "fold-const.h"
 
 
 /* Number of parallel tasks to run, -1 if we want to use GNU Make jobserver.  */
@@ -3226,6 +3228,37 @@ lto_init (void)
 #endif
 }
 
+/* Create artificial pointers for "omp declare target link" vars.  */
+
+static void
+offload_handle_link_vars (void)
+{
+#ifdef ACCEL_COMPILER
+  varpool_node *var;
+  FOR_EACH_VARIABLE (var)
+    if (lookup_attribute ("omp declare target link",
+			  DECL_ATTRIBUTES (var->decl)))
+      {
+	tree type = build_pointer_type (TREE_TYPE (var->decl));
+	tree link_ptr_var = make_node (VAR_DECL);
+	TREE_TYPE (link_ptr_var) = type;
+	TREE_USED (link_ptr_var) = 1;
+	TREE_STATIC (link_ptr_var) = 1;
+	DECL_MODE (link_ptr_var) = TYPE_MODE (type);
+	DECL_SIZE (link_ptr_var) = TYPE_SIZE (type);
+	DECL_SIZE_UNIT (link_ptr_var) = TYPE_SIZE_UNIT (type);
+	DECL_ARTIFICIAL (link_ptr_var) = 1;
+	tree var_name = DECL_ASSEMBLER_NAME (var->decl);
+	char *new_name
+	  = ACONCAT ((IDENTIFIER_POINTER (var_name), "_linkptr", NULL));
+	DECL_NAME (link_ptr_var) = get_identifier (new_name);
+	SET_DECL_ASSEMBLER_NAME (link_ptr_var, DECL_NAME (link_ptr_var));
+	SET_DECL_VALUE_EXPR (var->decl, build_simple_mem_ref (link_ptr_var));
+	DECL_HAS_VALUE_EXPR_P (var->decl) = 1;
+      }
+#endif
+}
+
 
 /* Main entry point for the GIMPLE front end.  This front end has
    three main personalities:
@@ -3274,6 +3307,8 @@ lto_main (void)
 
   if (!seen_error ())
     {
+      offload_handle_link_vars ();
+
       /* If WPA is enabled analyze the whole call graph and create an
 	 optimization plan.  Otherwise, read in all the function
 	 bodies and continue with optimization.  */
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"
diff --git a/gcc/passes.def b/gcc/passes.def
index 43ce3d5..c72b38b 100644
--- a/gcc/passes.def
+++ b/gcc/passes.def
@@ -170,6 +170,7 @@ along with GCC; see the file COPYING3.  If not see
   NEXT_PASS (pass_fixup_cfg);
   NEXT_PASS (pass_lower_eh_dispatch);
   NEXT_PASS (pass_oacc_device_lower);
+  NEXT_PASS (pass_omp_target_link);
   NEXT_PASS (pass_all_optimizations);
   PUSH_INSERT_PASSES_WITHIN (pass_all_optimizations)
       NEXT_PASS (pass_remove_cgraph_callee_edges);
diff --git a/gcc/tree-pass.h b/gcc/tree-pass.h
index e1cbce9..a13a865 100644
--- a/gcc/tree-pass.h
+++ b/gcc/tree-pass.h
@@ -417,6 +417,7 @@ extern gimple_opt_pass *make_pass_lower_omp (gcc::context *ctxt);
 extern gimple_opt_pass *make_pass_diagnose_omp_blocks (gcc::context *ctxt);
 extern gimple_opt_pass *make_pass_expand_omp (gcc::context *ctxt);
 extern gimple_opt_pass *make_pass_expand_omp_ssa (gcc::context *ctxt);
+extern gimple_opt_pass *make_pass_omp_target_link (gcc::context *ctxt);
 extern gimple_opt_pass *make_pass_oacc_device_lower (gcc::context *ctxt);
 extern gimple_opt_pass *make_pass_object_sizes (gcc::context *ctxt);
 extern gimple_opt_pass *make_pass_strlen (gcc::context *ctxt);
diff --git a/gcc/varpool.c b/gcc/varpool.c
index 5e4fcbf..d0101a1 100644
--- a/gcc/varpool.c
+++ b/gcc/varpool.c
@@ -748,6 +748,13 @@ symbol_table::output_variables (void)
       /* Handled in output_in_order.  */
       if (node->no_reorder)
 	continue;
+#ifdef ACCEL_COMPILER
+      /* Do not assemble "omp declare target link" vars.  */
+      if (DECL_HAS_VALUE_EXPR_P (node->decl)
+	  && lookup_attribute ("omp declare target link",
+			       DECL_ATTRIBUTES (node->decl)))
+	continue;
+#endif
       if (node->assemble_decl ())
         changed = true;
     }