Move nested function info out of cgraph_node

this patch moves nested function information out of symbol table (to a summary).
This saves memory (especially at WPA time) and also makes nested function
support more contained.

gcc/ChangeLog:

2020-10-22  Jan Hubicka  <hubicka@ucw.cz>

	* cgraph.c: Include tree-nested.h
	(cgraph_node::create): Call maybe_record_nested_function.
	(cgraph_node::remove): Do not remove function from nested function
	infos.
	(cgraph_node::dump): Update.
	(cgraph_node::unnest): Move to tree-nested.c
	(cgraph_node::verify_node): Update.
	(cgraph_c_finalize): Call nested_function_info::release.
	* cgraph.h (struct symtab_node): Remove nested function info.
	* cgraphclones.c (cgraph_node::create_clone): Do not clone nested
	function info.
	* cgraphunit.c (cgraph_node::analyze): Update.
	(cgraph_node::expand): Do not worry about nested functions; they are
	lowered.
	(symbol_table::finalize_compilation_unit): Call
	nested_function_info::release.
	* gimplify.c: Include tree-nested.h
	(unshare_body): Update.
	(unvisit_body): Update.
	* omp-offload.c (omp_discover_implicit_declare_target): Update.
	* tree-nested.c: Include alloc-pool.h, tree-nested.h, symbol-summary.h
	(nested_function_sum): New static variable.
	(nested_function_info::get): New member function.
	(nested_function_info::get_create): New member function.
	(unnest_function): New function.
	(nested_function_info::~nested_function_info): New member function.
	(nested_function_info::release): New function.
	(maybe_record_nested_function): New function.
	(lookup_element_for_decl): Update.
	(check_for_nested_with_variably_modified): Update.
	(create_nesting_tree): Update.
	(unnest_nesting_tree_1): Update.
	(gimplify_all_functions): Update.
	(lower_nested_functions): Update.
	* tree-nested.h (class nested_function_info): New class.
	(maybe_record_nested_function): Declare.
	(unnest_function): Declare.
	(first_nested_function): New inline function.
	(next_nested_function): New inline function.
	(nested_function_origin): New inline function.

gcc/ada/ChangeLog:

2020-10-22  Jan Hubicka  <hubicka@ucw.cz>

	* gcc-interface/trans.c: Include tree-nested.h
	(walk_nesting_tree): Update for new nested function info.

gcc/c-family/ChangeLog:

2020-10-22  Jan Hubicka  <hubicka@ucw.cz>

	* c-gimplify.c: Include tree-nested.h
	(c_genericize): Update for new nested function info.

gcc/d/ChangeLog:

2020-10-22  Jan Hubicka  <hubicka@ucw.cz>

	* decl.cc: Include tree-nested.h
	(get_symbol_decl): Update for new nested function info.

1 files changed, 1 insertions, 11 deletions

diff --git a/gcc/cgraph.h b/gcc/cgraph.h
index 96d6cf609fe..c953a1b6711 100644
--- a/gcc/cgraph.h
+++ b/gcc/cgraph.h
@@ -921,7 +921,7 @@ struct GTY((tag ("SYMTAB_FUNCTION"))) cgraph_node : public symtab_node
   /* Constructor.  */
   explicit cgraph_node (int uid)
     : symtab_node (SYMTAB_FUNCTION), callees (NULL), callers (NULL),
-      indirect_calls (NULL), origin (NULL), nested (NULL), next_nested (NULL),
+      indirect_calls (NULL),
       next_sibling_clone (NULL), prev_sibling_clone (NULL), clones (NULL),
       clone_of (NULL), call_site_hash (NULL), former_clone_of (NULL),
       simdclone (NULL), simd_clones (NULL), ipa_transforms_to_apply (vNULL),
@@ -1161,9 +1161,6 @@ struct GTY((tag ("SYMTAB_FUNCTION"))) cgraph_node : public symtab_node
   /* Return the DECL_STRUCT_FUNCTION of the function.  */
   struct function *get_fun () const;
 
-  /* cgraph_node is no longer nested function; update cgraph accordingly.  */
-  void unnest (void);
-
   /* Bring cgraph node local.  */
   void make_local (void);
 
@@ -1436,13 +1433,6 @@ struct GTY((tag ("SYMTAB_FUNCTION"))) cgraph_node : public symtab_node
   /* List of edges representing indirect calls with a yet undetermined
      callee.  */
   cgraph_edge *indirect_calls;
-  /* For nested functions points to function the node is nested in.  */
-  cgraph_node *origin;
-  /* Points to first nested function, if any.  */
-  cgraph_node *nested;
-  /* Pointer to the next function with same origin, if any.  */
-  cgraph_node *next_nested;
-  /* Pointer to the next clone.  */
   cgraph_node *next_sibling_clone;
   cgraph_node *prev_sibling_clone;
   cgraph_node *clones;