CbC/CbC_gcc: gcc/lto/lto-common.c comparison

comparison gcc/lto/lto-common.c @ 145:1830386684a0

gcc-9.2.0

author	anatofuz
date	Thu, 13 Feb 2020 11:34:05 +0900
parents
children

comparison

equal deleted inserted replaced

-:84e7813d76e9
+:1830386684a0
+/* Top-level LTO routines.
+Copyright (C) 2009-2020 Free Software Foundation, Inc.
+Contributed by CodeSourcery, Inc.
+This file is part of GCC.
+GCC is free software; you can redistribute it and/or modify it under
+the terms of the GNU General Public License as published by the Free
+Software Foundation; either version 3, or (at your option) any later
+version.
+GCC is distributed in the hope that it will be useful, but WITHOUT ANY
+WARRANTY; without even the implied warranty of MERCHANTABILITY or
+FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+for more details.
+You should have received a copy of the GNU General Public License
+along with GCC; see the file COPYING3.  If not see
+<http://www.gnu.org/licenses/>.  */
+#include "config.h"
+#include "system.h"
+#include "coretypes.h"
+#include "tm.h"
+#include "function.h"
+#include "bitmap.h"
+#include "basic-block.h"
+#include "tree.h"
+#include "gimple.h"
+#include "cfghooks.h"
+#include "alloc-pool.h"
+#include "tree-pass.h"
+#include "tree-streamer.h"
+#include "cgraph.h"
+#include "opts.h"
+#include "toplev.h"
+#include "stor-layout.h"
+#include "symbol-summary.h"
+#include "tree-vrp.h"
+#include "ipa-prop.h"
+#include "common.h"
+#include "debug.h"
+#include "lto.h"
+#include "lto-section-names.h"
+#include "splay-tree.h"
+#include "lto-partition.h"
+#include "context.h"
+#include "pass_manager.h"
+#include "ipa-fnsummary.h"
+#include "ipa-utils.h"
+#include "gomp-constants.h"
+#include "lto-symtab.h"
+#include "stringpool.h"
+#include "fold-const.h"
+#include "attribs.h"
+#include "builtins.h"
+#include "lto-common.h"
+#include "tree-pretty-print.h"
+/* True when no new types are going to be streamd from the global stream.  */
+static bool type_streaming_finished = false;
+GTY(()) tree first_personality_decl;
+GTY(()) const unsigned char *lto_mode_identity_table;
+/* Returns a hash code for P.  */
+static hashval_t
+hash_name (const void *p)
+{
+const struct lto_section_slot *ds = (const struct lto_section_slot *) p;
+return (hashval_t) htab_hash_string (ds->name);
+}
+/* Returns nonzero if P1 and P2 are equal.  */
+static int
+eq_name (const void *p1, const void *p2)
+{
+const struct lto_section_slot *s1
+= (const struct lto_section_slot *) p1;
+const struct lto_section_slot *s2
+= (const struct lto_section_slot *) p2;
+return strcmp (s1->name, s2->name) == 0;
+}
+/* Free lto_section_slot.  */
+static void
+free_with_string (void *arg)
+{
+struct lto_section_slot *s = (struct lto_section_slot *)arg;
+free (CONST_CAST (char *, s->name));
+free (arg);
+}
+/* Create section hash table.  */
+htab_t
+lto_obj_create_section_hash_table (void)
+{
+return htab_create (37, hash_name, eq_name, free_with_string);
+}
+/* Delete an allocated integer KEY in the splay tree.  */
+static void
+lto_splay_tree_delete_id (splay_tree_key key)
+{
+free ((void *) key);
+}
+/* Compare splay tree node ids A and B.  */
+static int
+lto_splay_tree_compare_ids (splay_tree_key a, splay_tree_key b)
+{
+unsigned HOST_WIDE_INT ai;
+unsigned HOST_WIDE_INT bi;
+ai = *(unsigned HOST_WIDE_INT *) a;
+bi = *(unsigned HOST_WIDE_INT *) b;
+if (ai < bi)
+return -1;
+else if (ai > bi)
+return 1;
+return 0;
+}
+/* Look up splay tree node by ID in splay tree T.  */
+static splay_tree_node
+lto_splay_tree_lookup (splay_tree t, unsigned HOST_WIDE_INT id)
+{
+return splay_tree_lookup (t, (splay_tree_key) &id);
+}
+/* Check if KEY has ID.  */
+static bool
+lto_splay_tree_id_equal_p (splay_tree_key key, unsigned HOST_WIDE_INT id)
+{
+return *(unsigned HOST_WIDE_INT *) key == id;
+}
+/* Insert a splay tree node into tree T with ID as key and FILE_DATA as value.
+The ID is allocated separately because we need HOST_WIDE_INTs which may
+be wider than a splay_tree_key.  */
+static void
+lto_splay_tree_insert (splay_tree t, unsigned HOST_WIDE_INT id,
+		       struct lto_file_decl_data *file_data)
+{
+unsigned HOST_WIDE_INT *idp = XCNEW (unsigned HOST_WIDE_INT);
+*idp = id;
+splay_tree_insert (t, (splay_tree_key) idp, (splay_tree_value) file_data);
+}
+/* Create a splay tree.  */
+static splay_tree
+lto_splay_tree_new (void)
+{
+return splay_tree_new (lto_splay_tree_compare_ids,
+			 lto_splay_tree_delete_id,
+			 NULL);
+}
+/* Decode the content of memory pointed to by DATA in the in decl
+state object STATE.  DATA_IN points to a data_in structure for
+decoding.  Return the address after the decoded object in the
+input.  */
+static const uint32_t *
+lto_read_in_decl_state (class data_in *data_in, const uint32_t *data,
+			struct lto_in_decl_state *state)
+{
+uint32_t ix;
+tree decl;
+uint32_t i, j;
+ix = *data++;
+state->compressed = ix & 1;
+ix /= 2;
+decl = streamer_tree_cache_get_tree (data_in->reader_cache, ix);
+if (!VAR_OR_FUNCTION_DECL_P (decl))
+{
+gcc_assert (decl == void_type_node);
+decl = NULL_TREE;
+}
+state->fn_decl = decl;
+for (i = 0; i < LTO_N_DECL_STREAMS; i++)
+{
+uint32_t size = *data++;
+vec<tree, va_gc> *decls = NULL;
+vec_alloc (decls, size);
+for (j = 0; j < size; j++)
+	vec_safe_push (decls,
+		       streamer_tree_cache_get_tree (data_in->reader_cache,
+						     data[j]));
+state->streams[i] = decls;
+data += size;
+}
+return data;
+}
+/* Global canonical type table.  */
+static htab_t gimple_canonical_types;
+static hash_map<const_tree, hashval_t> *canonical_type_hash_cache;
+static unsigned long num_canonical_type_hash_entries;
+static unsigned long num_canonical_type_hash_queries;
+/* Types postponed for registration to the canonical type table.
+During streaming we postpone all TYPE_CXX_ODR_P types so we can alter
+decide whether there is conflict with non-ODR type or not.  */
+static GTY(()) vec<tree, va_gc> *types_to_register = NULL;
+static void iterative_hash_canonical_type (tree type, inchash::hash &hstate);
+static hashval_t gimple_canonical_type_hash (const void *p);
+static hashval_t gimple_register_canonical_type_1 (tree t, hashval_t hash);
+/* Returning a hash value for gimple type TYPE.
+The hash value returned is equal for types considered compatible
+by gimple_canonical_types_compatible_p.  */
+static hashval_t
+hash_canonical_type (tree type)
+{
+inchash::hash hstate;
+enum tree_code code;
+/* We compute alias sets only for types that needs them.
+Be sure we do not recurse to something else as we cannot hash incomplete
+types in a way they would have same hash value as compatible complete
+types.  */
+gcc_checking_assert (type_with_alias_set_p (type));
+/* Combine a few common features of types so that types are grouped into
+smaller sets; when searching for existing matching types to merge,
+only existing types having the same features as the new type will be
+checked.  */
+code = tree_code_for_canonical_type_merging (TREE_CODE (type));
+hstate.add_int (code);
+hstate.add_int (TYPE_MODE (type));
+/* Incorporate common features of numerical types.  */
+if (INTEGRAL_TYPE_P (type)
+|| SCALAR_FLOAT_TYPE_P (type)
+|| FIXED_POINT_TYPE_P (type)
+|| TREE_CODE (type) == OFFSET_TYPE
+|| POINTER_TYPE_P (type))
+{
+hstate.add_int (TYPE_PRECISION (type));
+if (!type_with_interoperable_signedness (type))
+	hstate.add_int (TYPE_UNSIGNED (type));
+}
+if (VECTOR_TYPE_P (type))
+{
+hstate.add_poly_int (TYPE_VECTOR_SUBPARTS (type));
+hstate.add_int (TYPE_UNSIGNED (type));
+}
+if (TREE_CODE (type) == COMPLEX_TYPE)
+hstate.add_int (TYPE_UNSIGNED (type));
+/* Fortran's C_SIGNED_CHAR is !TYPE_STRING_FLAG but needs to be
+interoperable with "signed char".  Unless all frontends are revisited to
+agree on these types, we must ignore the flag completely.  */
+/* Fortran standard define C_PTR type that is compatible with every
+C pointer.  For this reason we need to glob all pointers into one.
+Still pointers in different address spaces are not compatible.  */
+if (POINTER_TYPE_P (type))
+hstate.add_int (TYPE_ADDR_SPACE (TREE_TYPE (type)));
+/* For array types hash the domain bounds and the string flag.  */
+if (TREE_CODE (type) == ARRAY_TYPE && TYPE_DOMAIN (type))
+{
+hstate.add_int (TYPE_STRING_FLAG (type));
+/* OMP lowering can introduce error_mark_node in place of
+	 random local decls in types.  */
+if (TYPE_MIN_VALUE (TYPE_DOMAIN (type)) != error_mark_node)
+	inchash::add_expr (TYPE_MIN_VALUE (TYPE_DOMAIN (type)), hstate);
+if (TYPE_MAX_VALUE (TYPE_DOMAIN (type)) != error_mark_node)
+	inchash::add_expr (TYPE_MAX_VALUE (TYPE_DOMAIN (type)), hstate);
+}
+/* Recurse for aggregates with a single element type.  */
+if (TREE_CODE (type) == ARRAY_TYPE
+|| TREE_CODE (type) == COMPLEX_TYPE
+|| TREE_CODE (type) == VECTOR_TYPE)
+iterative_hash_canonical_type (TREE_TYPE (type), hstate);
+/* Incorporate function return and argument types.  */
+if (TREE_CODE (type) == FUNCTION_TYPE || TREE_CODE (type) == METHOD_TYPE)
+{
+unsigned na;
+tree p;
+iterative_hash_canonical_type (TREE_TYPE (type), hstate);
+for (p = TYPE_ARG_TYPES (type), na = 0; p; p = TREE_CHAIN (p))
+	{
+	  iterative_hash_canonical_type (TREE_VALUE (p), hstate);
+	  na++;
+	}
+hstate.add_int (na);
+}
+if (RECORD_OR_UNION_TYPE_P (type))
+{
+unsigned nf;
+tree f;
+for (f = TYPE_FIELDS (type), nf = 0; f; f = TREE_CHAIN (f))
+	if (TREE_CODE (f) == FIELD_DECL
+	    && (! DECL_SIZE (f)
+		|| ! integer_zerop (DECL_SIZE (f))))
+	  {
+	    iterative_hash_canonical_type (TREE_TYPE (f), hstate);
+	    nf++;
+	  }
+hstate.add_int (nf);
+}
+return hstate.end();
+}
+/* Returning a hash value for gimple type TYPE combined with VAL.  */
+static void
+iterative_hash_canonical_type (tree type, inchash::hash &hstate)
+{
+hashval_t v;
+/* All type variants have same TYPE_CANONICAL.  */
+type = TYPE_MAIN_VARIANT (type);
+if (!canonical_type_used_p (type))
+v = hash_canonical_type (type);
+/* An already processed type.  */
+else if (TYPE_CANONICAL (type))
+{
+type = TYPE_CANONICAL (type);
+v = gimple_canonical_type_hash (type);
+}
+else
+{
+/* Canonical types should not be able to form SCCs by design, this
+	 recursion is just because we do not register canonical types in
+	 optimal order.  To avoid quadratic behavior also register the
+	 type here.  */
+v = hash_canonical_type (type);
+v = gimple_register_canonical_type_1 (type, v);
+}
+hstate.merge_hash (v);
+}
+/* Returns the hash for a canonical type P.  */
+static hashval_t
+gimple_canonical_type_hash (const void *p)
+{
+num_canonical_type_hash_queries++;
+hashval_t *slot = canonical_type_hash_cache->get ((const_tree) p);
+gcc_assert (slot != NULL);
+return *slot;
+}
+/* Returns nonzero if P1 and P2 are equal.  */
+static int
+gimple_canonical_type_eq (const void *p1, const void *p2)
+{
+const_tree t1 = (const_tree) p1;
+const_tree t2 = (const_tree) p2;
+return gimple_canonical_types_compatible_p (CONST_CAST_TREE (t1),
+					      CONST_CAST_TREE (t2));
+}
+/* Main worker for gimple_register_canonical_type.  */
+static hashval_t
+gimple_register_canonical_type_1 (tree t, hashval_t hash)
+{
+void **slot;
+gcc_checking_assert (TYPE_P (t) && !TYPE_CANONICAL (t)
+		       && type_with_alias_set_p (t)
+		       && canonical_type_used_p (t));
+/* ODR types for which there is no ODR violation and we did not record
+structurally equivalent non-ODR type can be treated as unique by their
+name.
+hash passed to gimple_register_canonical_type_1 is a structural hash
+that we can use to lookup structurally equivalent non-ODR type.
+In case we decide to treat type as unique ODR type we recompute hash based
+on name and let TBAA machinery know about our decision.  */
+if (RECORD_OR_UNION_TYPE_P (t)
+&& odr_type_p (t) && !odr_type_violation_reported_p (t))
+{
+/* Anonymous namespace types never conflict with non-C++ types.  */
+if (type_with_linkage_p (t) && type_in_anonymous_namespace_p (t))
+	slot = NULL;
+else
+	{
+	  /* Here we rely on fact that all non-ODR types was inserted into
+	     canonical type hash and thus we can safely detect conflicts between
+	     ODR types and interoperable non-ODR types.  */
+	  gcc_checking_assert (type_streaming_finished
+			       && TYPE_MAIN_VARIANT (t) == t);
+	  slot = htab_find_slot_with_hash (gimple_canonical_types, t, hash,
+					   NO_INSERT);
+	}
+if (slot && !TYPE_CXX_ODR_P (*(tree *)slot))
+	{
+	  tree nonodr = *(tree *)slot;
+	  if (symtab->dump_file)
+	    {
+	      fprintf (symtab->dump_file,
+		       "ODR and non-ODR type conflict: ");
+	      print_generic_expr (symtab->dump_file, t);
+	      fprintf (symtab->dump_file, " and ");
+	      print_generic_expr (symtab->dump_file, nonodr);
+	      fprintf (symtab->dump_file, " mangled:%s\n",
+			 IDENTIFIER_POINTER
+			   (DECL_ASSEMBLER_NAME (TYPE_NAME (t))));
+	    }
+	  /* Set canonical for T and all other ODR equivalent duplicates
+	     including incomplete structures.  */
+	  set_type_canonical_for_odr_type (t, nonodr);
+	}
+else
+	{
+	  tree prevail = prevailing_odr_type (t);
+	  if (symtab->dump_file)
+	    {
+	      fprintf (symtab->dump_file,
+		       "New canonical ODR type: ");
+	      print_generic_expr (symtab->dump_file, t);
+	      fprintf (symtab->dump_file, " mangled:%s\n",
+			 IDENTIFIER_POINTER
+			   (DECL_ASSEMBLER_NAME (TYPE_NAME (t))));
+	    }
+	  /* Set canonical for T and all other ODR equivalent duplicates
+	     including incomplete structures.  */
+	  set_type_canonical_for_odr_type (t, prevail);
+	  enable_odr_based_tbaa (t);
+	  if (!type_in_anonymous_namespace_p (t))
+	    hash = htab_hash_string (IDENTIFIER_POINTER
+					   (DECL_ASSEMBLER_NAME
+						   (TYPE_NAME (t))));
+	  else
+	    hash = TYPE_UID (t);
+	  /* All variants of t now have TYPE_CANONICAL set to prevail.
+	     Update canonical type hash cache accordingly.  */
+	  num_canonical_type_hash_entries++;
+	  bool existed_p = canonical_type_hash_cache->put (prevail, hash);
+	  gcc_checking_assert (!existed_p);
+	}
+return hash;
+}
+slot = htab_find_slot_with_hash (gimple_canonical_types, t, hash, INSERT);
+if (*slot)
+{
+tree new_type = (tree)(*slot);
+gcc_checking_assert (new_type != t);
+TYPE_CANONICAL (t) = new_type;
+}
+else
+{
+TYPE_CANONICAL (t) = t;
+*slot = (void *) t;
+/* Cache the just computed hash value.  */
+num_canonical_type_hash_entries++;
+bool existed_p = canonical_type_hash_cache->put (t, hash);
+gcc_assert (!existed_p);
+}
+return hash;
+}
+/* Register type T in the global type table gimple_types and set
+TYPE_CANONICAL of T accordingly.
+This is used by LTO to merge structurally equivalent types for
+type-based aliasing purposes across different TUs and languages.
+???  This merging does not exactly match how the tree.c middle-end
+functions will assign TYPE_CANONICAL when new types are created
+during optimization (which at least happens for pointer and array
+types).  */
+static void
+gimple_register_canonical_type (tree t)
+{
+if (TYPE_CANONICAL (t) || !type_with_alias_set_p (t)
+|| !canonical_type_used_p (t))
+return;
+/* Canonical types are same among all complete variants.  */
+if (TYPE_CANONICAL (TYPE_MAIN_VARIANT (t)))
+TYPE_CANONICAL (t) = TYPE_CANONICAL (TYPE_MAIN_VARIANT (t));
+else
+{
+hashval_t h = hash_canonical_type (TYPE_MAIN_VARIANT (t));
+gimple_register_canonical_type_1 (TYPE_MAIN_VARIANT (t), h);
+TYPE_CANONICAL (t) = TYPE_CANONICAL (TYPE_MAIN_VARIANT (t));
+}
+}
+/* Re-compute TYPE_CANONICAL for NODE and related types.  */
+static void
+lto_register_canonical_types (tree node, bool first_p)
+{
+if (!node
+|| !TYPE_P (node))
+return;
+if (first_p)
+TYPE_CANONICAL (node) = NULL_TREE;
+if (POINTER_TYPE_P (node)
+|| TREE_CODE (node) == COMPLEX_TYPE
+|| TREE_CODE (node) == ARRAY_TYPE)
+lto_register_canonical_types (TREE_TYPE (node), first_p);
+if (!first_p)
+gimple_register_canonical_type (node);
+}
+/* Finish canonical type calculation: after all units has been streamed in we
+can check if given ODR type structurally conflicts with a non-ODR type.  In
+the first case we set type canonical according to the canonical type hash.
+In the second case we use type names.  */
+static void
+lto_register_canonical_types_for_odr_types ()
+{
+tree t;
+unsigned int i;
+if (!types_to_register)
+return;
+type_streaming_finished = true;
+/* Be sure that no types derived from ODR types was
+not inserted into the hash table.  */
+if (flag_checking)
+FOR_EACH_VEC_ELT (*types_to_register, i, t)
+gcc_assert (!TYPE_CANONICAL (t));
+/* Register all remaining types.  */
+FOR_EACH_VEC_ELT (*types_to_register, i, t)
+{
+/* For pre-streamed types like va-arg it is possible that main variant
+	 is !CXX_ODR_P while the variant (which is streamed) is.
+	 Copy CXX_ODR_P to make type verifier happy.  This is safe because
+	 in canonical type calculation we only consider main variants.
+	 However we can not change this flag before streaming is finished
+	 to not affect tree merging.  */
+TYPE_CXX_ODR_P (t) = TYPE_CXX_ODR_P (TYPE_MAIN_VARIANT (t));
+if (!TYPE_CANONICAL (t))
+gimple_register_canonical_type (t);
+}
+}
+/* Remember trees that contains references to declarations.  */
+vec <tree, va_gc> *tree_with_vars;
+#define CHECK_VAR(tt) \
+do \
+{ \
+if ((tt) && VAR_OR_FUNCTION_DECL_P (tt) \
+	  && (TREE_PUBLIC (tt) || DECL_EXTERNAL (tt))) \
+	return true; \
+} while (0)
+#define CHECK_NO_VAR(tt) \
+gcc_checking_assert (!(tt) || !VAR_OR_FUNCTION_DECL_P (tt))
+/* Check presence of pointers to decls in fields of a tree_typed T.  */
+static inline bool
+mentions_vars_p_typed (tree t)
+{
+CHECK_NO_VAR (TREE_TYPE (t));
+return false;
+}
+/* Check presence of pointers to decls in fields of a tree_common T.  */
+static inline bool
+mentions_vars_p_common (tree t)
+{
+if (mentions_vars_p_typed (t))
+return true;
+CHECK_NO_VAR (TREE_CHAIN (t));
+return false;
+}
+/* Check presence of pointers to decls in fields of a decl_minimal T.  */
+static inline bool
+mentions_vars_p_decl_minimal (tree t)
+{
+if (mentions_vars_p_common (t))
+return true;
+CHECK_NO_VAR (DECL_NAME (t));
+CHECK_VAR (DECL_CONTEXT (t));
+return false;
+}
+/* Check presence of pointers to decls in fields of a decl_common T.  */
+static inline bool
+mentions_vars_p_decl_common (tree t)
+{
+if (mentions_vars_p_decl_minimal (t))
+return true;
+CHECK_VAR (DECL_SIZE (t));
+CHECK_VAR (DECL_SIZE_UNIT (t));
+CHECK_VAR (DECL_INITIAL (t));
+CHECK_NO_VAR (DECL_ATTRIBUTES (t));
+CHECK_VAR (DECL_ABSTRACT_ORIGIN (t));
+return false;
+}
+/* Check presence of pointers to decls in fields of a decl_with_vis T.  */
+static inline bool
+mentions_vars_p_decl_with_vis (tree t)
+{
+if (mentions_vars_p_decl_common (t))
+return true;
+/* Accessor macro has side-effects, use field-name here.  */
+CHECK_NO_VAR (DECL_ASSEMBLER_NAME_RAW (t));
+return false;
+}
+/* Check presence of pointers to decls in fields of a decl_non_common T.  */
+static inline bool
+mentions_vars_p_decl_non_common (tree t)
+{
+if (mentions_vars_p_decl_with_vis (t))
+return true;
+CHECK_NO_VAR (DECL_RESULT_FLD (t));
+return false;
+}
+/* Check presence of pointers to decls in fields of a decl_non_common T.  */
+static bool
+mentions_vars_p_function (tree t)
+{
+if (mentions_vars_p_decl_non_common (t))
+return true;
+CHECK_NO_VAR (DECL_ARGUMENTS (t));
+CHECK_NO_VAR (DECL_VINDEX (t));
+CHECK_VAR (DECL_FUNCTION_PERSONALITY (t));
+return false;
+}
+/* Check presence of pointers to decls in fields of a field_decl T.  */
+static bool
+mentions_vars_p_field_decl (tree t)
+{
+if (mentions_vars_p_decl_common (t))
+return true;
+CHECK_VAR (DECL_FIELD_OFFSET (t));
+CHECK_NO_VAR (DECL_BIT_FIELD_TYPE (t));
+CHECK_NO_VAR (DECL_QUALIFIER (t));
+CHECK_NO_VAR (DECL_FIELD_BIT_OFFSET (t));
+CHECK_NO_VAR (DECL_FCONTEXT (t));
+return false;
+}
+/* Check presence of pointers to decls in fields of a type T.  */
+static bool
+mentions_vars_p_type (tree t)
+{
+if (mentions_vars_p_common (t))
+return true;
+CHECK_NO_VAR (TYPE_CACHED_VALUES (t));
+CHECK_VAR (TYPE_SIZE (t));
+CHECK_VAR (TYPE_SIZE_UNIT (t));
+CHECK_NO_VAR (TYPE_ATTRIBUTES (t));
+CHECK_NO_VAR (TYPE_NAME (t));
+CHECK_VAR (TYPE_MIN_VALUE_RAW (t));
+CHECK_VAR (TYPE_MAX_VALUE_RAW (t));
+/* Accessor is for derived node types only.  */
+CHECK_NO_VAR (TYPE_LANG_SLOT_1 (t));
+CHECK_VAR (TYPE_CONTEXT (t));
+CHECK_NO_VAR (TYPE_CANONICAL (t));
+CHECK_NO_VAR (TYPE_MAIN_VARIANT (t));
+CHECK_NO_VAR (TYPE_NEXT_VARIANT (t));
+return false;
+}
+/* Check presence of pointers to decls in fields of a BINFO T.  */
+static bool
+mentions_vars_p_binfo (tree t)
+{
+unsigned HOST_WIDE_INT i, n;
+if (mentions_vars_p_common (t))
+return true;
+CHECK_VAR (BINFO_VTABLE (t));
+CHECK_NO_VAR (BINFO_OFFSET (t));
+CHECK_NO_VAR (BINFO_VIRTUALS (t));
+CHECK_NO_VAR (BINFO_VPTR_FIELD (t));
+n = vec_safe_length (BINFO_BASE_ACCESSES (t));
+for (i = 0; i < n; i++)
+CHECK_NO_VAR (BINFO_BASE_ACCESS (t, i));
+/* Do not walk BINFO_INHERITANCE_CHAIN, BINFO_SUBVTT_INDEX
+and BINFO_VPTR_INDEX; these are used by C++ FE only.  */
+n = BINFO_N_BASE_BINFOS (t);
+for (i = 0; i < n; i++)
+CHECK_NO_VAR (BINFO_BASE_BINFO (t, i));
+return false;
+}
+/* Check presence of pointers to decls in fields of a CONSTRUCTOR T.  */
+static bool
+mentions_vars_p_constructor (tree t)
+{
+unsigned HOST_WIDE_INT idx;
+constructor_elt *ce;
+if (mentions_vars_p_typed (t))
+return true;
+for (idx = 0; vec_safe_iterate (CONSTRUCTOR_ELTS (t), idx, &ce); idx++)
+{
+CHECK_NO_VAR (ce->index);
+CHECK_VAR (ce->value);
+}
+return false;
+}
+/* Check presence of pointers to decls in fields of an expression tree T.  */
+static bool
+mentions_vars_p_expr (tree t)
+{
+int i;
+if (mentions_vars_p_typed (t))
+return true;
+for (i = TREE_OPERAND_LENGTH (t) - 1; i >= 0; --i)
+CHECK_VAR (TREE_OPERAND (t, i));
+return false;
+}
+/* Check presence of pointers to decls in fields of an OMP_CLAUSE T.  */
+static bool
+mentions_vars_p_omp_clause (tree t)
+{
+int i;
+if (mentions_vars_p_common (t))
+return true;
+for (i = omp_clause_num_ops[OMP_CLAUSE_CODE (t)] - 1; i >= 0; --i)
+CHECK_VAR (OMP_CLAUSE_OPERAND (t, i));
+return false;
+}
+/* Check presence of pointers to decls that needs later fixup in T.  */
+static bool
+mentions_vars_p (tree t)
+{
+switch (TREE_CODE (t))
+{
+case IDENTIFIER_NODE:
+break;
+case TREE_LIST:
+CHECK_VAR (TREE_VALUE (t));
+CHECK_VAR (TREE_PURPOSE (t));
+CHECK_NO_VAR (TREE_CHAIN (t));
+break;
+case FIELD_DECL:
+return mentions_vars_p_field_decl (t);
+case LABEL_DECL:
+case CONST_DECL:
+case PARM_DECL:
+case RESULT_DECL:
+case IMPORTED_DECL:
+case NAMESPACE_DECL:
+case NAMELIST_DECL:
+return mentions_vars_p_decl_common (t);
+case VAR_DECL:
+return mentions_vars_p_decl_with_vis (t);
+case TYPE_DECL:
+return mentions_vars_p_decl_non_common (t);
+case FUNCTION_DECL:
+return mentions_vars_p_function (t);
+case TREE_BINFO:
+return mentions_vars_p_binfo (t);
+case PLACEHOLDER_EXPR:
+return mentions_vars_p_common (t);
+case BLOCK:
+case TRANSLATION_UNIT_DECL:
+case OPTIMIZATION_NODE:
+case TARGET_OPTION_NODE:
+break;
+case CONSTRUCTOR:
+return mentions_vars_p_constructor (t);
+case OMP_CLAUSE:
+return mentions_vars_p_omp_clause (t);
+default:
+if (TYPE_P (t))
+	{
+	  if (mentions_vars_p_type (t))
+	    return true;
+	}
+else if (EXPR_P (t))
+	{
+	  if (mentions_vars_p_expr (t))
+	    return true;
+	}
+else if (CONSTANT_CLASS_P (t))
+	CHECK_NO_VAR (TREE_TYPE (t));
+else
+	gcc_unreachable ();
+}
+return false;
+}
+/* Return the resolution for the decl with index INDEX from DATA_IN.  */
+static enum ld_plugin_symbol_resolution
+get_resolution (class data_in *data_in, unsigned index)
+{
+if (data_in->globals_resolution.exists ())
+{
+ld_plugin_symbol_resolution_t ret;
+/* We can have references to not emitted functions in
+	 DECL_FUNCTION_PERSONALITY at least.  So we can and have
+	 to indeed return LDPR_UNKNOWN in some cases.  */
+if (data_in->globals_resolution.length () <= index)
+	return LDPR_UNKNOWN;
+ret = data_in->globals_resolution[index];
+return ret;
+}
+else
+/* Delay resolution finding until decl merging.  */
+return LDPR_UNKNOWN;
+}
+/* We need to record resolutions until symbol table is read.  */
+static void
+register_resolution (struct lto_file_decl_data *file_data, tree decl,
+		     enum ld_plugin_symbol_resolution resolution)
+{
+bool existed;
+if (resolution == LDPR_UNKNOWN)
+return;
+if (!file_data->resolution_map)
+file_data->resolution_map
+= new hash_map<tree, ld_plugin_symbol_resolution>;
+ld_plugin_symbol_resolution_t &res
+= file_data->resolution_map->get_or_insert (decl, &existed);
+if (!existed
+|| resolution == LDPR_PREVAILING_DEF_IRONLY
+|| resolution == LDPR_PREVAILING_DEF
+|| resolution == LDPR_PREVAILING_DEF_IRONLY_EXP)
+res = resolution;
+}
+/* Register DECL with the global symbol table and change its
+name if necessary to avoid name clashes for static globals across
+different files.  */
+static void
+lto_register_var_decl_in_symtab (class data_in *data_in, tree decl,
+				 unsigned ix)
+{
+tree context;
+/* Variable has file scope, not local.  */
+if (!TREE_PUBLIC (decl)
+&& !((context = decl_function_context (decl))
+	   && auto_var_in_fn_p (decl, context)))
+rest_of_decl_compilation (decl, 1, 0);
+/* If this variable has already been declared, queue the
+declaration for merging.  */
+if (TREE_PUBLIC (decl))
+register_resolution (data_in->file_data,
+			 decl, get_resolution (data_in, ix));
+}
+/* Register DECL with the global symbol table and change its
+name if necessary to avoid name clashes for static globals across
+different files.  DATA_IN contains descriptors and tables for the
+file being read.  */
+static void
+lto_register_function_decl_in_symtab (class data_in *data_in, tree decl,
+				      unsigned ix)
+{
+/* If this variable has already been declared, queue the
+declaration for merging.  */
+if (TREE_PUBLIC (decl) && !DECL_ABSTRACT_P (decl))
+register_resolution (data_in->file_data,
+			 decl, get_resolution (data_in, ix));
+}
+/* Check if T is a decl and needs register its resolution info.  */
+static void
+lto_maybe_register_decl (class data_in *data_in, tree t, unsigned ix)
+{
+if (TREE_CODE (t) == VAR_DECL)
+lto_register_var_decl_in_symtab (data_in, t, ix);
+else if (TREE_CODE (t) == FUNCTION_DECL
+	   && !fndecl_built_in_p (t))
+lto_register_function_decl_in_symtab (data_in, t, ix);
+}
+/* For the type T re-materialize it in the type variant list and
+the pointer/reference-to chains.  */
+static void
+lto_fixup_prevailing_type (tree t)
+{
+/* The following re-creates proper variant lists while fixing up
+the variant leaders.  We do not stream TYPE_NEXT_VARIANT so the
+variant list state before fixup is broken.  */
+/* If we are not our own variant leader link us into our new leaders
+variant list.  */
+if (TYPE_MAIN_VARIANT (t) != t)
+{
+tree mv = TYPE_MAIN_VARIANT (t);
+TYPE_NEXT_VARIANT (t) = TYPE_NEXT_VARIANT (mv);
+TYPE_NEXT_VARIANT (mv) = t;
+}
+/* The following reconstructs the pointer chains
+of the new pointed-to type if we are a main variant.  We do
+not stream those so they are broken before fixup.  */
+if (TREE_CODE (t) == POINTER_TYPE
+&& TYPE_MAIN_VARIANT (t) == t)
+{
+TYPE_NEXT_PTR_TO (t) = TYPE_POINTER_TO (TREE_TYPE (t));
+TYPE_POINTER_TO (TREE_TYPE (t)) = t;
+}
+else if (TREE_CODE (t) == REFERENCE_TYPE
+	   && TYPE_MAIN_VARIANT (t) == t)
+{
+TYPE_NEXT_REF_TO (t) = TYPE_REFERENCE_TO (TREE_TYPE (t));
+TYPE_REFERENCE_TO (TREE_TYPE (t)) = t;
+}
+}
+/* We keep prevailing tree SCCs in a hashtable with manual collision
+handling (in case all hashes compare the same) and keep the colliding
+entries in the tree_scc->next chain.  */
+struct tree_scc
+{
+tree_scc *next;
+/* Hash of the whole SCC.  */
+hashval_t hash;
+/* Number of trees in the SCC.  */
+unsigned len;
+/* Number of possible entries into the SCC (tree nodes [0..entry_len-1]
+which share the same individual tree hash).  */
+unsigned entry_len;
+/* The members of the SCC.
+We only need to remember the first entry node candidate for prevailing
+SCCs (but of course have access to all entries for SCCs we are
+processing).
+???  For prevailing SCCs we really only need hash and the first
+entry candidate, but that's too awkward to implement.  */
+tree entries[1];
+};
+struct tree_scc_hasher : nofree_ptr_hash <tree_scc>
+{
+static inline hashval_t hash (const tree_scc *);
+static inline bool equal (const tree_scc *, const tree_scc *);
+};
+hashval_t
+tree_scc_hasher::hash (const tree_scc *scc)
+{
+return scc->hash;
+}
+bool
+tree_scc_hasher::equal (const tree_scc *scc1, const tree_scc *scc2)
+{
+if (scc1->hash != scc2->hash
+|| scc1->len != scc2->len
+|| scc1->entry_len != scc2->entry_len)
+return false;
+return true;
+}
+static hash_table<tree_scc_hasher> *tree_scc_hash;
+static struct obstack tree_scc_hash_obstack;
+static unsigned long num_merged_types;
+static unsigned long num_prevailing_types;
+static unsigned long num_type_scc_trees;
+static unsigned long total_scc_size;
+static unsigned long num_sccs_read;
+static unsigned long total_scc_size_merged;
+static unsigned long num_sccs_merged;
+static unsigned long num_scc_compares;
+static unsigned long num_scc_compare_collisions;
+/* Compare the two entries T1 and T2 of two SCCs that are possibly equal,
+recursing through in-SCC tree edges.  Returns true if the SCCs entered
+through T1 and T2 are equal and fills in *MAP with the pairs of
+SCC entries we visited, starting with (*MAP)[0] = T1 and (*MAP)[1] = T2.  */
+static bool
+compare_tree_sccs_1 (tree t1, tree t2, tree **map)
+{
+enum tree_code code;
+/* Mark already visited nodes.  */
+TREE_ASM_WRITTEN (t2) = 1;
+/* Push the pair onto map.  */
+(*map)[0] = t1;
+(*map)[1] = t2;
+*map = *map + 2;
+/* Compare value-fields.  */
+#define compare_values(X) \
+do { \
+if (X(t1) != X(t2)) \
+return false; \
+} while (0)
+compare_values (TREE_CODE);
+code = TREE_CODE (t1);
+if (!TYPE_P (t1))
+{
+compare_values (TREE_SIDE_EFFECTS);
+compare_values (TREE_CONSTANT);
+compare_values (TREE_READONLY);
+compare_values (TREE_PUBLIC);
+}
+compare_values (TREE_ADDRESSABLE);
+compare_values (TREE_THIS_VOLATILE);
+if (DECL_P (t1))
+compare_values (DECL_UNSIGNED);
+else if (TYPE_P (t1))
+compare_values (TYPE_UNSIGNED);
+if (TYPE_P (t1))
+compare_values (TYPE_ARTIFICIAL);
+else
+compare_values (TREE_NO_WARNING);
+compare_values (TREE_NOTHROW);
+compare_values (TREE_STATIC);
+if (code != TREE_BINFO)
+compare_values (TREE_PRIVATE);
+compare_values (TREE_PROTECTED);
+compare_values (TREE_DEPRECATED);
+if (TYPE_P (t1))
+{
+if (AGGREGATE_TYPE_P (t1))
+	compare_values (TYPE_REVERSE_STORAGE_ORDER);
+else
+	compare_values (TYPE_SATURATING);
+compare_values (TYPE_ADDR_SPACE);
+}
+else if (code == SSA_NAME)
+compare_values (SSA_NAME_IS_DEFAULT_DEF);
+if (CODE_CONTAINS_STRUCT (code, TS_INT_CST))
+{
+if (wi::to_wide (t1) != wi::to_wide (t2))
+	return false;
+}
+if (CODE_CONTAINS_STRUCT (code, TS_REAL_CST))
+{
+/* ???  No suitable compare routine available.  */
+REAL_VALUE_TYPE r1 = TREE_REAL_CST (t1);
+REAL_VALUE_TYPE r2 = TREE_REAL_CST (t2);
+if (r1.cl != r2.cl
+	  || r1.decimal != r2.decimal
+	  || r1.sign != r2.sign
+	  || r1.signalling != r2.signalling
+	  || r1.canonical != r2.canonical
+	  || r1.uexp != r2.uexp)
+	return false;
+for (unsigned i = 0; i < SIGSZ; ++i)
+	if (r1.sig[i] != r2.sig[i])
+	  return false;
+}
+if (CODE_CONTAINS_STRUCT (code, TS_FIXED_CST))
+if (!fixed_compare (EQ_EXPR,
+			TREE_FIXED_CST_PTR (t1), TREE_FIXED_CST_PTR (t2)))
+return false;
+if (CODE_CONTAINS_STRUCT (code, TS_VECTOR))
+{
+compare_values (VECTOR_CST_LOG2_NPATTERNS);
+compare_values (VECTOR_CST_NELTS_PER_PATTERN);
+}
+if (CODE_CONTAINS_STRUCT (code, TS_DECL_COMMON))
+{
+compare_values (DECL_MODE);
+compare_values (DECL_NONLOCAL);
+compare_values (DECL_VIRTUAL_P);
+compare_values (DECL_IGNORED_P);
+compare_values (DECL_ABSTRACT_P);
+compare_values (DECL_ARTIFICIAL);
+compare_values (DECL_USER_ALIGN);
+compare_values (DECL_PRESERVE_P);
+compare_values (DECL_EXTERNAL);
+compare_values (DECL_GIMPLE_REG_P);
+compare_values (DECL_ALIGN);
+if (code == LABEL_DECL)
+	{
+	  compare_values (EH_LANDING_PAD_NR);
+	  compare_values (LABEL_DECL_UID);
+	}
+else if (code == FIELD_DECL)
+	{
+	  compare_values (DECL_PACKED);
+	  compare_values (DECL_NONADDRESSABLE_P);
+	  compare_values (DECL_PADDING_P);
+	  compare_values (DECL_OFFSET_ALIGN);
+	}
+else if (code == VAR_DECL)
+	{
+	  compare_values (DECL_HAS_DEBUG_EXPR_P);
+	  compare_values (DECL_NONLOCAL_FRAME);
+	}
+if (code == RESULT_DECL
+	  || code == PARM_DECL
+	  || code == VAR_DECL)
+	{
+	  compare_values (DECL_BY_REFERENCE);
+	  if (code == VAR_DECL
+	      || code == PARM_DECL)
+	    compare_values (DECL_HAS_VALUE_EXPR_P);
+	}
+}
+if (CODE_CONTAINS_STRUCT (code, TS_DECL_WRTL))
+compare_values (DECL_REGISTER);
+if (CODE_CONTAINS_STRUCT (code, TS_DECL_WITH_VIS))
+{
+compare_values (DECL_COMMON);
+compare_values (DECL_DLLIMPORT_P);
+compare_values (DECL_WEAK);
+compare_values (DECL_SEEN_IN_BIND_EXPR_P);
+compare_values (DECL_COMDAT);
+compare_values (DECL_VISIBILITY);
+compare_values (DECL_VISIBILITY_SPECIFIED);
+if (code == VAR_DECL)
+	{
+	  compare_values (DECL_HARD_REGISTER);
+	  /* DECL_IN_TEXT_SECTION is set during final asm output only.  */
+	  compare_values (DECL_IN_CONSTANT_POOL);
+	}
+}
+if (CODE_CONTAINS_STRUCT (code, TS_FUNCTION_DECL))
+{
+compare_values (DECL_BUILT_IN_CLASS);
+compare_values (DECL_STATIC_CONSTRUCTOR);
+compare_values (DECL_STATIC_DESTRUCTOR);
+compare_values (DECL_UNINLINABLE);
+compare_values (DECL_POSSIBLY_INLINED);
+compare_values (DECL_IS_NOVOPS);
+compare_values (DECL_IS_RETURNS_TWICE);
+compare_values (DECL_IS_MALLOC);
+compare_values (DECL_IS_OPERATOR_NEW_P);
+compare_values (DECL_DECLARED_INLINE_P);
+compare_values (DECL_STATIC_CHAIN);
+compare_values (DECL_NO_INLINE_WARNING_P);
+compare_values (DECL_NO_INSTRUMENT_FUNCTION_ENTRY_EXIT);
+compare_values (DECL_NO_LIMIT_STACK);
+compare_values (DECL_DISREGARD_INLINE_LIMITS);
+compare_values (DECL_PURE_P);
+compare_values (DECL_LOOPING_CONST_OR_PURE_P);
+compare_values (DECL_FINAL_P);
+compare_values (DECL_CXX_CONSTRUCTOR_P);
+compare_values (DECL_CXX_DESTRUCTOR_P);
+if (DECL_BUILT_IN_CLASS (t1) != NOT_BUILT_IN)
+	compare_values (DECL_UNCHECKED_FUNCTION_CODE);
+}
+if (CODE_CONTAINS_STRUCT (code, TS_TYPE_COMMON))
+{
+compare_values (TYPE_MODE);
+compare_values (TYPE_NEEDS_CONSTRUCTING);
+if (RECORD_OR_UNION_TYPE_P (t1))
+	{
+	  compare_values (TYPE_TRANSPARENT_AGGR);
+	  compare_values (TYPE_FINAL_P);
+compare_values (TYPE_CXX_ODR_P);
+	}
+else if (code == ARRAY_TYPE)
+	compare_values (TYPE_NONALIASED_COMPONENT);
+if (code == ARRAY_TYPE || code == INTEGER_TYPE)
+compare_values (TYPE_STRING_FLAG);
+if (AGGREGATE_TYPE_P (t1))
+	compare_values (TYPE_TYPELESS_STORAGE);
+compare_values (TYPE_EMPTY_P);
+compare_values (TYPE_PACKED);
+compare_values (TYPE_RESTRICT);
+compare_values (TYPE_USER_ALIGN);
+compare_values (TYPE_READONLY);
+compare_values (TYPE_PRECISION);
+compare_values (TYPE_ALIGN);
+/* Do not compare TYPE_ALIAS_SET.  Doing so introduce ordering issues
+	 with calls to get_alias_set which may initialize it for streamed
+	 in types.  */
+}
+/* We don't want to compare locations, so there is nothing do compare
+for TS_EXP.  */
+/* BLOCKs are function local and we don't merge anything there, so
+simply refuse to merge.  */
+if (CODE_CONTAINS_STRUCT (code, TS_BLOCK))
+return false;
+if (CODE_CONTAINS_STRUCT (code, TS_TRANSLATION_UNIT_DECL))
+if (strcmp (TRANSLATION_UNIT_LANGUAGE (t1),
+		TRANSLATION_UNIT_LANGUAGE (t2)) != 0)
+return false;
+if (CODE_CONTAINS_STRUCT (code, TS_TARGET_OPTION))
+if (!cl_target_option_eq (TREE_TARGET_OPTION (t1), TREE_TARGET_OPTION (t2)))
+return false;
+if (CODE_CONTAINS_STRUCT (code, TS_OPTIMIZATION))
+if (!cl_optimization_option_eq (TREE_OPTIMIZATION (t1),
+				    TREE_OPTIMIZATION (t2)))
+return false;
+if (CODE_CONTAINS_STRUCT (code, TS_BINFO))
+if (vec_safe_length (BINFO_BASE_ACCESSES (t1))
+	!= vec_safe_length (BINFO_BASE_ACCESSES (t2)))
+return false;
+if (CODE_CONTAINS_STRUCT (code, TS_CONSTRUCTOR))
+compare_values (CONSTRUCTOR_NELTS);
+if (CODE_CONTAINS_STRUCT (code, TS_IDENTIFIER))
+if (IDENTIFIER_LENGTH (t1) != IDENTIFIER_LENGTH (t2)
+	|| memcmp (IDENTIFIER_POINTER (t1), IDENTIFIER_POINTER (t2),
+		   IDENTIFIER_LENGTH (t1)) != 0)
+return false;
+if (CODE_CONTAINS_STRUCT (code, TS_STRING))
+if (TREE_STRING_LENGTH (t1) != TREE_STRING_LENGTH (t2)
+	|| memcmp (TREE_STRING_POINTER (t1), TREE_STRING_POINTER (t2),
+		   TREE_STRING_LENGTH (t1)) != 0)
+return false;
+if (code == OMP_CLAUSE)
+{
+compare_values (OMP_CLAUSE_CODE);
+switch (OMP_CLAUSE_CODE (t1))
+	{
+	case OMP_CLAUSE_DEFAULT:
+	  compare_values (OMP_CLAUSE_DEFAULT_KIND);
+	  break;
+	case OMP_CLAUSE_SCHEDULE:
+	  compare_values (OMP_CLAUSE_SCHEDULE_KIND);
+	  break;
+	case OMP_CLAUSE_DEPEND:
+	  compare_values (OMP_CLAUSE_DEPEND_KIND);
+	  break;
+	case OMP_CLAUSE_MAP:
+	  compare_values (OMP_CLAUSE_MAP_KIND);
+	  break;
+	case OMP_CLAUSE_PROC_BIND:
+	  compare_values (OMP_CLAUSE_PROC_BIND_KIND);
+	  break;
+	case OMP_CLAUSE_REDUCTION:
+	  compare_values (OMP_CLAUSE_REDUCTION_CODE);
+	  compare_values (OMP_CLAUSE_REDUCTION_GIMPLE_INIT);
+	  compare_values (OMP_CLAUSE_REDUCTION_GIMPLE_MERGE);
+	  break;
+	default:
+	  break;
+	}
+}
+#undef compare_values
+/* Compare pointer fields.  */
+/* Recurse.  Search & Replaced from DFS_write_tree_body.
+Folding the early checks into the compare_tree_edges recursion
+macro makes debugging way quicker as you are able to break on
+compare_tree_sccs_1 and simply finish until a call returns false
+to spot the SCC members with the difference.  */
+#define compare_tree_edges(E1, E2) \
+do { \
+tree t1_ = (E1), t2_ = (E2); \
+if (t1_ != t2_ \
+	&& (!t1_ || !t2_ \
+	    || !TREE_VISITED (t2_) \
+	    || (!TREE_ASM_WRITTEN (t2_) \
+		&& !compare_tree_sccs_1 (t1_, t2_, map)))) \
+return false; \
+/* Only non-NULL trees outside of the SCC may compare equal.  */ \
+gcc_checking_assert (t1_ != t2_ || (!t2_ || !TREE_VISITED (t2_))); \
+} while (0)
+if (CODE_CONTAINS_STRUCT (code, TS_TYPED))
+{
+if (code != IDENTIFIER_NODE)
+	compare_tree_edges (TREE_TYPE (t1), TREE_TYPE (t2));
+}
+if (CODE_CONTAINS_STRUCT (code, TS_VECTOR))
+{
+/* Note that the number of elements for EXPR has already been emitted
+	 in EXPR's header (see streamer_write_tree_header).  */
+unsigned int count = vector_cst_encoded_nelts (t1);
+for (unsigned int i = 0; i < count; ++i)
+	compare_tree_edges (VECTOR_CST_ENCODED_ELT (t1, i),
+			    VECTOR_CST_ENCODED_ELT (t2, i));
+}
+if (CODE_CONTAINS_STRUCT (code, TS_COMPLEX))
+{
+compare_tree_edges (TREE_REALPART (t1), TREE_REALPART (t2));
+compare_tree_edges (TREE_IMAGPART (t1), TREE_IMAGPART (t2));
+}
+if (CODE_CONTAINS_STRUCT (code, TS_DECL_MINIMAL))
+{
+compare_tree_edges (DECL_NAME (t1), DECL_NAME (t2));
+/* ???  Global decls from different TUs have non-matching
+	 TRANSLATION_UNIT_DECLs.  Only consider a small set of
+	 decls equivalent, we should not end up merging others.  */
+if ((code == TYPE_DECL
+	   || code == NAMESPACE_DECL
+	   || code == IMPORTED_DECL
+	   || code == CONST_DECL
+	   || (VAR_OR_FUNCTION_DECL_P (t1)
+	       && (TREE_PUBLIC (t1) || DECL_EXTERNAL (t1))))
+	  && DECL_FILE_SCOPE_P (t1) && DECL_FILE_SCOPE_P (t2))
+	;
+else
+	compare_tree_edges (DECL_CONTEXT (t1), DECL_CONTEXT (t2));
+}
+if (CODE_CONTAINS_STRUCT (code, TS_DECL_COMMON))
+{
+compare_tree_edges (DECL_SIZE (t1), DECL_SIZE (t2));
+compare_tree_edges (DECL_SIZE_UNIT (t1), DECL_SIZE_UNIT (t2));
+compare_tree_edges (DECL_ATTRIBUTES (t1), DECL_ATTRIBUTES (t2));
+compare_tree_edges (DECL_ABSTRACT_ORIGIN (t1), DECL_ABSTRACT_ORIGIN (t2));
+if ((code == VAR_DECL
+	   || code == PARM_DECL)
+	  && DECL_HAS_VALUE_EXPR_P (t1))
+	compare_tree_edges (DECL_VALUE_EXPR (t1), DECL_VALUE_EXPR (t2));
+if (code == VAR_DECL
+	  && DECL_HAS_DEBUG_EXPR_P (t1))
+	compare_tree_edges (DECL_DEBUG_EXPR (t1), DECL_DEBUG_EXPR (t2));
+/* LTO specific edges.  */
+if (code != FUNCTION_DECL
+	  && code != TRANSLATION_UNIT_DECL)
+	compare_tree_edges (DECL_INITIAL (t1), DECL_INITIAL (t2));
+}
+if (CODE_CONTAINS_STRUCT (code, TS_DECL_NON_COMMON))
+{
+if (code == FUNCTION_DECL)
+	{
+	  tree a1, a2;
+	  for (a1 = DECL_ARGUMENTS (t1), a2 = DECL_ARGUMENTS (t2);
+	       a1 || a2;
+	       a1 = TREE_CHAIN (a1), a2 = TREE_CHAIN (a2))
+	    compare_tree_edges (a1, a2);
+	  compare_tree_edges (DECL_RESULT (t1), DECL_RESULT (t2));
+	}
+else if (code == TYPE_DECL)
+	compare_tree_edges (DECL_ORIGINAL_TYPE (t1), DECL_ORIGINAL_TYPE (t2));
+}
+if (CODE_CONTAINS_STRUCT (code, TS_DECL_WITH_VIS))
+{
+/* Make sure we don't inadvertently set the assembler name.  */
+if (DECL_ASSEMBLER_NAME_SET_P (t1))
+	compare_tree_edges (DECL_ASSEMBLER_NAME (t1),
+			    DECL_ASSEMBLER_NAME (t2));
+}
+if (CODE_CONTAINS_STRUCT (code, TS_FIELD_DECL))
+{
+compare_tree_edges (DECL_FIELD_OFFSET (t1), DECL_FIELD_OFFSET (t2));
+compare_tree_edges (DECL_BIT_FIELD_TYPE (t1), DECL_BIT_FIELD_TYPE (t2));
+compare_tree_edges (DECL_BIT_FIELD_REPRESENTATIVE (t1),
+			  DECL_BIT_FIELD_REPRESENTATIVE (t2));
+compare_tree_edges (DECL_FIELD_BIT_OFFSET (t1),
+			  DECL_FIELD_BIT_OFFSET (t2));
+compare_tree_edges (DECL_FCONTEXT (t1), DECL_FCONTEXT (t2));
+}
+if (CODE_CONTAINS_STRUCT (code, TS_FUNCTION_DECL))
+{
+compare_tree_edges (DECL_FUNCTION_PERSONALITY (t1),
+			  DECL_FUNCTION_PERSONALITY (t2));
+compare_tree_edges (DECL_VINDEX (t1), DECL_VINDEX (t2));
+compare_tree_edges (DECL_FUNCTION_SPECIFIC_TARGET (t1),
+			  DECL_FUNCTION_SPECIFIC_TARGET (t2));
+compare_tree_edges (DECL_FUNCTION_SPECIFIC_OPTIMIZATION (t1),
+			  DECL_FUNCTION_SPECIFIC_OPTIMIZATION (t2));
+}
+if (CODE_CONTAINS_STRUCT (code, TS_TYPE_COMMON))
+{
+compare_tree_edges (TYPE_SIZE (t1), TYPE_SIZE (t2));
+compare_tree_edges (TYPE_SIZE_UNIT (t1), TYPE_SIZE_UNIT (t2));
+compare_tree_edges (TYPE_ATTRIBUTES (t1), TYPE_ATTRIBUTES (t2));
+compare_tree_edges (TYPE_NAME (t1), TYPE_NAME (t2));
+/* Do not compare TYPE_POINTER_TO or TYPE_REFERENCE_TO.  They will be
+	 reconstructed during fixup.  */
+/* Do not compare TYPE_NEXT_VARIANT, we reconstruct the variant lists
+	 during fixup.  */
+compare_tree_edges (TYPE_MAIN_VARIANT (t1), TYPE_MAIN_VARIANT (t2));
+/* ???  Global types from different TUs have non-matching
+	 TRANSLATION_UNIT_DECLs.  Still merge them if they are otherwise
+	 equal.  */
+if (TYPE_FILE_SCOPE_P (t1) && TYPE_FILE_SCOPE_P (t2))
+	;
+else
+	compare_tree_edges (TYPE_CONTEXT (t1), TYPE_CONTEXT (t2));
+/* TYPE_CANONICAL is re-computed during type merging, so do not
+	 compare it here.  */
+compare_tree_edges (TYPE_STUB_DECL (t1), TYPE_STUB_DECL (t2));
+}
+if (CODE_CONTAINS_STRUCT (code, TS_TYPE_NON_COMMON))
+{
+if (code == ENUMERAL_TYPE)
+	compare_tree_edges (TYPE_VALUES (t1), TYPE_VALUES (t2));
+else if (code == ARRAY_TYPE)
+	compare_tree_edges (TYPE_DOMAIN (t1), TYPE_DOMAIN (t2));
+else if (RECORD_OR_UNION_TYPE_P (t1))
+	{
+	  tree f1, f2;
+	  for (f1 = TYPE_FIELDS (t1), f2 = TYPE_FIELDS (t2);
+	       f1 || f2;
+	       f1 = TREE_CHAIN (f1), f2 = TREE_CHAIN (f2))
+	    compare_tree_edges (f1, f2);
+	}
+else if (code == FUNCTION_TYPE
+	       || code == METHOD_TYPE)
+	compare_tree_edges (TYPE_ARG_TYPES (t1), TYPE_ARG_TYPES (t2));
+if (!POINTER_TYPE_P (t1))
+	compare_tree_edges (TYPE_MIN_VALUE_RAW (t1), TYPE_MIN_VALUE_RAW (t2));
+compare_tree_edges (TYPE_MAX_VALUE_RAW (t1), TYPE_MAX_VALUE_RAW (t2));
+}
+if (CODE_CONTAINS_STRUCT (code, TS_LIST))
+{
+compare_tree_edges (TREE_PURPOSE (t1), TREE_PURPOSE (t2));
+compare_tree_edges (TREE_VALUE (t1), TREE_VALUE (t2));
+compare_tree_edges (TREE_CHAIN (t1), TREE_CHAIN (t2));
+}
+if (CODE_CONTAINS_STRUCT (code, TS_VEC))
+for (int i = 0; i < TREE_VEC_LENGTH (t1); i++)
+compare_tree_edges (TREE_VEC_ELT (t1, i), TREE_VEC_ELT (t2, i));
+if (CODE_CONTAINS_STRUCT (code, TS_EXP))
+{
+for (int i = 0; i < TREE_OPERAND_LENGTH (t1); i++)
+	compare_tree_edges (TREE_OPERAND (t1, i),
+			    TREE_OPERAND (t2, i));
+/* BLOCKs are function local and we don't merge anything there.  */
+if (TREE_BLOCK (t1) || TREE_BLOCK (t2))
+	return false;
+}
+if (CODE_CONTAINS_STRUCT (code, TS_BINFO))
+{
+unsigned i;
+tree t;
+/* Lengths have already been compared above.  */
+FOR_EACH_VEC_ELT (*BINFO_BASE_BINFOS (t1), i, t)
+	compare_tree_edges (t, BINFO_BASE_BINFO (t2, i));
+FOR_EACH_VEC_SAFE_ELT (BINFO_BASE_ACCESSES (t1), i, t)
+	compare_tree_edges (t, BINFO_BASE_ACCESS (t2, i));
+compare_tree_edges (BINFO_OFFSET (t1), BINFO_OFFSET (t2));
+compare_tree_edges (BINFO_VTABLE (t1), BINFO_VTABLE (t2));
+compare_tree_edges (BINFO_VPTR_FIELD (t1), BINFO_VPTR_FIELD (t2));
+/* Do not walk BINFO_INHERITANCE_CHAIN, BINFO_SUBVTT_INDEX
+	 and BINFO_VPTR_INDEX; these are used by C++ FE only.  */
+}
+if (CODE_CONTAINS_STRUCT (code, TS_CONSTRUCTOR))
+{
+unsigned i;
+tree index, value;
+/* Lengths have already been compared above.  */
+FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (t1), i, index, value)
+	{
+	  compare_tree_edges (index, CONSTRUCTOR_ELT (t2, i)->index);
+	  compare_tree_edges (value, CONSTRUCTOR_ELT (t2, i)->value);
+	}
+}
+if (code == OMP_CLAUSE)
+{
+int i;
+for (i = 0; i < omp_clause_num_ops[OMP_CLAUSE_CODE (t1)]; i++)
+	compare_tree_edges (OMP_CLAUSE_OPERAND (t1, i),
+			    OMP_CLAUSE_OPERAND (t2, i));
+compare_tree_edges (OMP_CLAUSE_CHAIN (t1), OMP_CLAUSE_CHAIN (t2));
+}
+#undef compare_tree_edges
+return true;
+}
+/* Compare the tree scc SCC to the prevailing candidate PSCC, filling
+out MAP if they are equal.  */
+static bool
+compare_tree_sccs (tree_scc *pscc, tree_scc *scc,
+		   tree *map)
+{
+/* Assume SCC entry hashes are sorted after their cardinality.  Which
+means we can simply take the first n-tuple of equal hashes
+(which is recorded as entry_len) and do n SCC entry candidate
+comparisons.  */
+for (unsigned i = 0; i < pscc->entry_len; ++i)
+{
+tree *mapp = map;
+num_scc_compare_collisions++;
+if (compare_tree_sccs_1 (pscc->entries[0], scc->entries[i], &mapp))
+	{
+	  /* Equal - no need to reset TREE_VISITED or TREE_ASM_WRITTEN
+	     on the scc as all trees will be freed.  */
+	  return true;
+	}
+/* Reset TREE_ASM_WRITTEN on scc for the next compare or in case
+	 the SCC prevails.  */
+for (unsigned j = 0; j < scc->len; ++j)
+	TREE_ASM_WRITTEN (scc->entries[j]) = 0;
+}
+return false;
+}
+/* QSort sort function to sort a map of two pointers after the 2nd
+pointer.  */
+static int
+cmp_tree (const void *p1_, const void *p2_)
+{
+tree *p1 = (tree *)(const_cast<void *>(p1_));
+tree *p2 = (tree *)(const_cast<void *>(p2_));
+if (p1[1] == p2[1])
+return 0;
+return ((uintptr_t)p1[1] < (uintptr_t)p2[1]) ? -1 : 1;
+}
+/* Try to unify the SCC with nodes FROM to FROM + LEN in CACHE and
+hash value SCC_HASH with an already recorded SCC.  Return true if
+that was successful, otherwise return false.  */
+static bool
+unify_scc (class data_in *data_in, unsigned from,
+	   unsigned len, unsigned scc_entry_len, hashval_t scc_hash)
+{
+bool unified_p = false;
+struct streamer_tree_cache_d *cache = data_in->reader_cache;
+tree_scc *scc
+= (tree_scc *) alloca (sizeof (tree_scc) + (len - 1) * sizeof (tree));
+scc->next = NULL;
+scc->hash = scc_hash;
+scc->len = len;
+scc->entry_len = scc_entry_len;
+for (unsigned i = 0; i < len; ++i)
+{
+tree t = streamer_tree_cache_get_tree (cache, from + i);
+scc->entries[i] = t;
+/* Do not merge SCCs with local entities inside them.  Also do
+	 not merge TRANSLATION_UNIT_DECLs and anonymous namespaces
+	 and types therein types.  */
+if (TREE_CODE (t) == TRANSLATION_UNIT_DECL
+	  || (VAR_OR_FUNCTION_DECL_P (t)
+	      && !(TREE_PUBLIC (t) || DECL_EXTERNAL (t)))
+	  || TREE_CODE (t) == LABEL_DECL
+	  || (TREE_CODE (t) == NAMESPACE_DECL && !DECL_NAME (t))
+	  || (TYPE_P (t)
+	      && type_with_linkage_p (TYPE_MAIN_VARIANT (t))
+	      && type_in_anonymous_namespace_p (TYPE_MAIN_VARIANT (t))))
+	{
+	  /* Avoid doing any work for these cases and do not worry to
+	     record the SCCs for further merging.  */
+	  return false;
+	}
+}
+/* Look for the list of candidate SCCs to compare against.  */
+tree_scc **slot;
+slot = tree_scc_hash->find_slot_with_hash (scc, scc_hash, INSERT);
+if (*slot)
+{
+/* Try unifying against each candidate.  */
+num_scc_compares++;
+/* Set TREE_VISITED on the scc so we can easily identify tree nodes
+	 outside of the scc when following tree edges.  Make sure
+	 that TREE_ASM_WRITTEN is unset so we can use it as 2nd bit
+	 to track whether we visited the SCC member during the compare.
+	 We cannot use TREE_VISITED on the pscc members as the extended
+	 scc and pscc can overlap.  */
+for (unsigned i = 0; i < scc->len; ++i)
+	{
+	  TREE_VISITED (scc->entries[i]) = 1;
+	  gcc_checking_assert (!TREE_ASM_WRITTEN (scc->entries[i]));
+	}
+tree *map = XALLOCAVEC (tree, 2 * len);
+for (tree_scc *pscc = *slot; pscc; pscc = pscc->next)
+	{
+	  if (!compare_tree_sccs (pscc, scc, map))
+	    continue;
+	  /* Found an equal SCC.  */
+	  unified_p = true;
+	  num_scc_compare_collisions--;
+	  num_sccs_merged++;
+	  total_scc_size_merged += len;
+	  if (flag_checking)
+	    for (unsigned i = 0; i < len; ++i)
+	      {
+		tree t = map[2*i+1];
+		enum tree_code code = TREE_CODE (t);
+		/* IDENTIFIER_NODEs should be singletons and are merged by the
+		   streamer.  The others should be singletons, too, and we
+		   should not merge them in any way.  */
+		gcc_assert (code != TRANSLATION_UNIT_DECL
+			    && code != IDENTIFIER_NODE);
+	      }
+	  /* Fixup the streamer cache with the prevailing nodes according
+	     to the tree node mapping computed by compare_tree_sccs.  */
+	  if (len == 1)
+	    {
+	      /* If we got a debug reference queued, see if the prevailing
+		 tree has a debug reference and if not, register the one
+		 for the tree we are about to throw away.  */
+	      if (dref_queue.length () == 1)
+		{
+		  dref_entry e = dref_queue.pop ();
+		  gcc_assert (e.decl
+			      == streamer_tree_cache_get_tree (cache, from));
+		  const char *sym;
+		  unsigned HOST_WIDE_INT off;
+		  if (!debug_hooks->die_ref_for_decl (pscc->entries[0], &sym,
+						      &off))
+		    debug_hooks->register_external_die (pscc->entries[0],
+							e.sym, e.off);
+		}
+	      lto_maybe_register_decl (data_in, pscc->entries[0], from);
+	      streamer_tree_cache_replace_tree (cache, pscc->entries[0], from);
+	    }
+	  else
+	    {
+	      tree *map2 = XALLOCAVEC (tree, 2 * len);
+	      for (unsigned i = 0; i < len; ++i)
+		{
+		  map2[i*2] = (tree)(uintptr_t)(from + i);
+		  map2[i*2+1] = scc->entries[i];
+		}
+	      qsort (map2, len, 2 * sizeof (tree), cmp_tree);
+	      qsort (map, len, 2 * sizeof (tree), cmp_tree);
+	      for (unsigned i = 0; i < len; ++i)
+		{
+		  lto_maybe_register_decl (data_in, map[2*i],
+					   (uintptr_t)map2[2*i]);
+		  streamer_tree_cache_replace_tree (cache, map[2*i],
+						    (uintptr_t)map2[2*i]);
+		}
+	    }
+	  /* Free the tree nodes from the read SCC.  */
+	  data_in->location_cache.revert_location_cache ();
+	  for (unsigned i = 0; i < len; ++i)
+	    {
+	      if (TYPE_P (scc->entries[i]))
+		num_merged_types++;
+	      free_node (scc->entries[i]);
+	    }
+	  /* Drop DIE references.
+	     ???  Do as in the size-one SCC case which involves sorting
+	     the queue.  */
+	  dref_queue.truncate (0);
+	  break;
+	}
+/* Reset TREE_VISITED if we didn't unify the SCC with another.  */
+if (!unified_p)
+	for (unsigned i = 0; i < scc->len; ++i)
+	  TREE_VISITED (scc->entries[i]) = 0;
+}
+/* If we didn't unify it to any candidate duplicate the relevant
+pieces to permanent storage and link it into the chain.  */
+if (!unified_p)
+{
+tree_scc *pscc
+	= XOBNEWVAR (&tree_scc_hash_obstack, tree_scc, sizeof (tree_scc));
+memcpy (pscc, scc, sizeof (tree_scc));
+pscc->next = (*slot);
+*slot = pscc;
+}
+return unified_p;
+}
+/* Read all the symbols from buffer DATA, using descriptors in DECL_DATA.
+RESOLUTIONS is the set of symbols picked by the linker (read from the
+resolution file when the linker plugin is being used).  */
+static void
+lto_read_decls (struct lto_file_decl_data *decl_data, const void *data,
+		vec<ld_plugin_symbol_resolution_t> resolutions)
+{
+const struct lto_decl_header *header = (const struct lto_decl_header *) data;
+const int decl_offset = sizeof (struct lto_decl_header);
+const int main_offset = decl_offset + header->decl_state_size;
+const int string_offset = main_offset + header->main_size;
+class data_in *data_in;
+unsigned int i;
+const uint32_t *data_ptr, *data_end;
+uint32_t num_decl_states;
+lto_input_block ib_main ((const char *) data + main_offset,
+			   header->main_size, decl_data->mode_table);
+data_in = lto_data_in_create (decl_data, (const char *) data + string_offset,
+				header->string_size, resolutions);
+/* We do not uniquify the pre-loaded cache entries, those are middle-end
+internal types that should not be merged.  */
+typedef int_hash<unsigned, 0, UINT_MAX> code_id_hash;
+hash_map <code_id_hash, unsigned> hm;
+unsigned total = 0;
+/* Read the global declarations and types.  */
+while (ib_main.p < ib_main.len)
+{
+tree t;
+unsigned from = data_in->reader_cache->nodes.length ();
+/* Read and uniquify SCCs as in the input stream.  */
+enum LTO_tags tag = streamer_read_record_start (&ib_main);
+if (tag == LTO_tree_scc)
+	{
+	  unsigned len_;
+	  unsigned scc_entry_len;
+	  hashval_t scc_hash = lto_input_scc (&ib_main, data_in, &len_,
+					      &scc_entry_len);
+	  unsigned len = data_in->reader_cache->nodes.length () - from;
+	  gcc_assert (len == len_);
+	  total_scc_size += len;
+	  num_sccs_read++;
+	  /* We have the special case of size-1 SCCs that are pre-merged
+	     by means of identifier and string sharing for example.
+	     ???  Maybe we should avoid streaming those as SCCs.  */
+	  tree first = streamer_tree_cache_get_tree (data_in->reader_cache,
+						     from);
+	  if (len == 1
+	      && (TREE_CODE (first) == IDENTIFIER_NODE
+		  || (TREE_CODE (first) == INTEGER_CST
+		      && !TREE_OVERFLOW (first))))
+	    continue;
+	  /* Try to unify the SCC with already existing ones.  */
+	  if (!flag_ltrans
+	      && unify_scc (data_in, from,
+			    len, scc_entry_len, scc_hash))
+	    continue;
+	  /* Tree merging failed, mark entries in location cache as
+	     permanent.  */
+	  data_in->location_cache.accept_location_cache ();
+	  bool seen_type = false;
+	  for (unsigned i = 0; i < len; ++i)
+	    {
+	      tree t = streamer_tree_cache_get_tree (data_in->reader_cache,
+						     from + i);
+	      /* Reconstruct the type variant and pointer-to/reference-to
+		 chains.  */
+	      if (TYPE_P (t))
+		{
+		  /* Map the tree types to their frequencies.  */
+		  if (flag_lto_dump_type_stats)
+		    {
+		      unsigned key = (unsigned) TREE_CODE (t);
+		      unsigned *countp = hm.get (key);
+		      hm.put (key, countp ? (*countp) + 1 : 1);
+		      total++;
+		    }
+		  seen_type = true;
+		  num_prevailing_types++;
+		  lto_fixup_prevailing_type (t);
+		  /* Compute the canonical type of all non-ODR types.
+		     Delay ODR types for the end of merging process - the canonical
+		     type for those can be computed using the (unique) name however
+		     we want to do this only if units in other languages do not
+		     contain structurally equivalent type.
+		     Because SCC components are streamed in random (hash) order
+		     we may have encountered the type before while registering
+		     type canonical of a derived type in the same SCC.  */
+		  if (!TYPE_CANONICAL (t))
+		    {
+		      if (!RECORD_OR_UNION_TYPE_P (t)
+			  || !TYPE_CXX_ODR_P (t))
+		        gimple_register_canonical_type (t);
+		      else if (COMPLETE_TYPE_P (t))
+			vec_safe_push (types_to_register, t);
+		    }
+		  if (TYPE_MAIN_VARIANT (t) == t && odr_type_p (t))
+		    register_odr_type (t);
+		}
+	      /* Link shared INTEGER_CSTs into TYPE_CACHED_VALUEs of its
+		 type which is also member of this SCC.  */
+	      if (TREE_CODE (t) == INTEGER_CST
+		  && !TREE_OVERFLOW (t))
+		cache_integer_cst (t);
+	      if (!flag_ltrans)
+		{
+		  lto_maybe_register_decl (data_in, t, from + i);
+		  /* Scan the tree for references to global functions or
+		     variables and record those for later fixup.  */
+		  if (mentions_vars_p (t))
+		    vec_safe_push (tree_with_vars, t);
+		}
+	    }
+	  /* Register DECLs with the debuginfo machinery.  */
+	  while (!dref_queue.is_empty ())
+	    {
+	      dref_entry e = dref_queue.pop ();
+	      debug_hooks->register_external_die (e.decl, e.sym, e.off);
+	    }
+	  if (seen_type)
+	    num_type_scc_trees += len;
+	}
+else
+	{
+	  /* Pickle stray references.  */
+	  t = lto_input_tree_1 (&ib_main, data_in, tag, 0);
+	  gcc_assert (t && data_in->reader_cache->nodes.length () == from);
+	}
+}
+/* Dump type statistics.  */
+if (flag_lto_dump_type_stats)
+{
+fprintf (stdout, "       Type     Frequency   Percentage\n\n");
+for (hash_map<code_id_hash, unsigned>::iterator itr = hm.begin ();
+	   itr != hm.end ();
+	   ++itr)
+	{
+	  std::pair<unsigned, unsigned> p = *itr;
+	  enum tree_code code = (enum tree_code) p.first;
+	  fprintf (stdout, "%14s %6d %12.2f\n", get_tree_code_name (code),
+		   p.second, float (p.second)/total*100);
+	}
+}
+data_in->location_cache.apply_location_cache ();
+/* Read in lto_in_decl_state objects.  */
+data_ptr = (const uint32_t *) ((const char*) data + decl_offset);
+data_end
+= (const uint32_t *) ((const char*) data_ptr + header->decl_state_size);
+num_decl_states = *data_ptr++;
+gcc_assert (num_decl_states > 0);
+decl_data->global_decl_state = lto_new_in_decl_state ();
+data_ptr = lto_read_in_decl_state (data_in, data_ptr,
+				     decl_data->global_decl_state);
+/* Read in per-function decl states and enter them in hash table.  */
+decl_data->function_decl_states
+= hash_table<decl_state_hasher>::create_ggc (37);
+for (i = 1; i < num_decl_states; i++)
+{
+struct lto_in_decl_state *state = lto_new_in_decl_state ();
+data_ptr = lto_read_in_decl_state (data_in, data_ptr, state);
+lto_in_decl_state **slot
+	= decl_data->function_decl_states->find_slot (state, INSERT);
+gcc_assert (*slot == NULL);
+*slot = state;
+}
+if (data_ptr != data_end)
+internal_error ("bytecode stream: garbage at the end of symbols section");
+/* Set the current decl state to be the global state.  */
+decl_data->current_decl_state = decl_data->global_decl_state;
+lto_data_in_delete (data_in);
+}
+/* Custom version of strtoll, which is not portable.  */
+static int64_t
+lto_parse_hex (const char *p)
+{
+int64_t ret = 0;
+for (; *p != '\0'; ++p)
+{
+char c = *p;
+unsigned char part;
+ret <<= 4;
+if (c >= '0' && c <= '9')
+	part = c - '0';
+else if (c >= 'a' && c <= 'f')
+	part = c - 'a' + 10;
+else if (c >= 'A' && c <= 'F')
+	part = c - 'A' + 10;
+else
+	internal_error ("could not parse hex number");
+ret |= part;
+}
+return ret;
+}
+/* Read resolution for file named FILE_NAME.  The resolution is read from
+RESOLUTION.  */
+static void
+lto_resolution_read (splay_tree file_ids, FILE *resolution, lto_file *file)
+{
+/* We require that objects in the resolution file are in the same
+order as the lto1 command line.  */
+unsigned int name_len;
+char *obj_name;
+unsigned int num_symbols;
+unsigned int i;
+struct lto_file_decl_data *file_data;
+splay_tree_node nd = NULL;
+if (!resolution)
+return;
+name_len = strlen (file->filename);
+obj_name = XNEWVEC (char, name_len + 1);
+fscanf (resolution, " ");   /* Read white space.  */
+fread (obj_name, sizeof (char), name_len, resolution);
+obj_name[name_len] = '\0';
+if (filename_cmp (obj_name, file->filename) != 0)
+internal_error ("unexpected file name %s in linker resolution file. "
+		    "Expected %s", obj_name, file->filename);
+if (file->offset != 0)
+{
+int t;
+char offset_p[17];
+int64_t offset;
+t = fscanf (resolution, "@0x%16s", offset_p);
+if (t != 1)
+	internal_error ("could not parse file offset");
+offset = lto_parse_hex (offset_p);
+if (offset != file->offset)
+	internal_error ("unexpected offset");
+}
+free (obj_name);
+fscanf (resolution, "%u", &num_symbols);
+for (i = 0; i < num_symbols; i++)
+{
+int t;
+unsigned index;
+unsigned HOST_WIDE_INT id;
+char r_str[27];
+enum ld_plugin_symbol_resolution r = (enum ld_plugin_symbol_resolution) 0;
+unsigned int j;
+unsigned int lto_resolution_str_len
+	= sizeof (lto_resolution_str) / sizeof (char *);
+res_pair rp;
+t = fscanf (resolution, "%u " HOST_WIDE_INT_PRINT_HEX_PURE
+		  " %26s %*[^\n]\n", &index, &id, r_str);
+if (t != 3)
+	internal_error ("invalid line in the resolution file");
+for (j = 0; j < lto_resolution_str_len; j++)
+	{
+	  if (strcmp (lto_resolution_str[j], r_str) == 0)
+	    {
+	      r = (enum ld_plugin_symbol_resolution) j;
+	      break;
+	    }
+	}
+if (j == lto_resolution_str_len)
+	internal_error ("invalid resolution in the resolution file");
+if (!(nd && lto_splay_tree_id_equal_p (nd->key, id)))
+	{
+	  nd = lto_splay_tree_lookup (file_ids, id);
+	  if (nd == NULL)
+	    internal_error ("resolution sub id %wx not in object file", id);
+	}
+file_data = (struct lto_file_decl_data *)nd->value;
+/* The indexes are very sparse.  To save memory save them in a compact
+	 format that is only unpacked later when the subfile is processed.  */
+rp.res = r;
+rp.index = index;
+file_data->respairs.safe_push (rp);
+if (file_data->max_index < index)
+	file_data->max_index = index;
+}
+}
+/* List of file_decl_datas.  */
+struct file_data_list
+{
+struct lto_file_decl_data *first, *last;
+};
+/* Is the name for a id'ed LTO section? */
+static int
+lto_section_with_id (const char *name, unsigned HOST_WIDE_INT *id)
+{
+const char *s;
+if (strncmp (name, section_name_prefix, strlen (section_name_prefix)))
+return 0;
+s = strrchr (name, '.');
+if (!s)
+return 0;
+/* If the section is not suffixed with an ID return.  */
+if ((size_t)(s - name) == strlen (section_name_prefix))
+return 0;
+return sscanf (s, "." HOST_WIDE_INT_PRINT_HEX_PURE, id) == 1;
+}
+/* Create file_data of each sub file id.  */
+static int
+create_subid_section_table (struct lto_section_slot *ls, splay_tree file_ids,
+			    struct file_data_list *list)
+{
+struct lto_section_slot s_slot, *new_slot;
+unsigned HOST_WIDE_INT id;
+splay_tree_node nd;
+void **hash_slot;
+char *new_name;
+struct lto_file_decl_data *file_data;
+if (!lto_section_with_id (ls->name, &id))
+return 1;
+/* Find hash table of sub module id.  */
+nd = lto_splay_tree_lookup (file_ids, id);
+if (nd != NULL)
+{
+file_data = (struct lto_file_decl_data *)nd->value;
+}
+else
+{
+file_data = ggc_alloc<lto_file_decl_data> ();
+memset(file_data, 0, sizeof (struct lto_file_decl_data));
+file_data->id = id;
+file_data->section_hash_table = lto_obj_create_section_hash_table ();
+lto_splay_tree_insert (file_ids, id, file_data);
+/* Maintain list in linker order.  */
+if (!list->first)
+	list->first = file_data;
+if (list->last)
+	list->last->next = file_data;
+list->last = file_data;
+}
+/* Copy section into sub module hash table.  */
+new_name = XDUPVEC (char, ls->name, strlen (ls->name) + 1);
+s_slot.name = new_name;
+hash_slot = htab_find_slot (file_data->section_hash_table, &s_slot, INSERT);
+gcc_assert (*hash_slot == NULL);
+new_slot = XDUP (struct lto_section_slot, ls);
+new_slot->name = new_name;
+*hash_slot = new_slot;
+return 1;
+}
+/* Read declarations and other initializations for a FILE_DATA.  */
+static void
+lto_file_finalize (struct lto_file_decl_data *file_data, lto_file *file,
+		   int order)
+{
+const char *data;
+size_t len;
+vec<ld_plugin_symbol_resolution_t>
+	resolutions = vNULL;
+int i;
+res_pair *rp;
+/* Create vector for fast access of resolution.  We do this lazily
+to save memory.  */
+resolutions.safe_grow_cleared (file_data->max_index + 1);
+for (i = 0; file_data->respairs.iterate (i, &rp); i++)
+resolutions[rp->index] = rp->res;
+file_data->respairs.release ();
+file_data->renaming_hash_table = lto_create_renaming_table ();
+file_data->file_name = file->filename;
+file_data->order = order;
+#ifdef ACCEL_COMPILER
+lto_input_mode_table (file_data);
+#else
+file_data->mode_table = lto_mode_identity_table;
+#endif
+/* Read and verify LTO section.  */
+data = lto_get_summary_section_data (file_data, LTO_section_lto, &len);
+if (data == NULL)
+{
+fatal_error (input_location, "bytecode stream in file %qs generated "
+		   "with GCC compiler older than 10.0", file_data->file_name);
+return;
+}
+memcpy (&file_data->lto_section_header, data, sizeof (lto_section));
+lto_check_version (file_data->lto_section_header.major_version,
+		     file_data->lto_section_header.minor_version,
+		     file_data->file_name);
+data = lto_get_summary_section_data (file_data, LTO_section_decls, &len);
+if (data == NULL)
+{
+internal_error ("cannot read %<LTO_section_decls%> from %s",
+		      file_data->file_name);
+return;
+}
+/* Frees resolutions.  */
+lto_read_decls (file_data, data, resolutions);
+lto_free_section_data (file_data, LTO_section_decls, NULL, data, len);
+}
+/* Finalize FILE_DATA in FILE and increase COUNT.  */
+static int
+lto_create_files_from_ids (lto_file *file, struct lto_file_decl_data *file_data,
+			   int *count, int order)
+{
+lto_file_finalize (file_data, file, order);
+if (symtab->dump_file)
+fprintf (symtab->dump_file,
+	     "Creating file %s with sub id " HOST_WIDE_INT_PRINT_HEX "\n",
+	     file_data->file_name, file_data->id);
+(*count)++;
+return 0;
+}
+/* Generate a TREE representation for all types and external decls
+entities in FILE.
+Read all of the globals out of the file.  Then read the cgraph
+and process the .o index into the cgraph nodes so that it can open
+the .o file to load the functions and ipa information.  */
+static struct lto_file_decl_data *
+lto_file_read (lto_file *file, FILE *resolution_file, int *count)
+{
+struct lto_file_decl_data *file_data = NULL;
+splay_tree file_ids;
+htab_t section_hash_table;
+struct lto_section_slot *section;
+struct file_data_list file_list;
+struct lto_section_list section_list;
+memset (&section_list, 0, sizeof (struct lto_section_list));
+section_hash_table = lto_obj_build_section_table (file, &section_list);
+/* Dump the details of LTO objects.  */
+if (flag_lto_dump_objects)
+{
+int i=0;
+fprintf (stdout, "\n    LTO Object Name: %s\n", file->filename);
+fprintf (stdout, "\nNo.    Offset    Size       Section Name\n\n");
+for (section = section_list.first; section != NULL; section = section->next)
+fprintf (stdout, "%2d %8" PRId64 " %8" PRIu64 "   %s\n",
+	       ++i, (int64_t) section->start, (uint64_t) section->len,
+	       section->name);
+}
+/* Find all sub modules in the object and put their sections into new hash
+tables in a splay tree.  */
+file_ids = lto_splay_tree_new ();
+memset (&file_list, 0, sizeof (struct file_data_list));
+for (section = section_list.first; section != NULL; section = section->next)
+create_subid_section_table (section, file_ids, &file_list);
+/* Add resolutions to file ids.  */
+lto_resolution_read (file_ids, resolution_file, file);
+/* Finalize each lto file for each submodule in the merged object.  */
+int order = 0;
+for (file_data = file_list.first; file_data != NULL;
+file_data = file_data->next)
+lto_create_files_from_ids (file, file_data, count, order++);
+splay_tree_delete (file_ids);
+htab_delete (section_hash_table);
+return file_list.first;
+}
+#if HAVE_MMAP_FILE && HAVE_SYSCONF && defined _SC_PAGE_SIZE
+#define LTO_MMAP_IO 1
+#endif
+#if LTO_MMAP_IO
+/* Page size of machine is used for mmap and munmap calls.  */
+static size_t page_mask;
+#endif
+/* Get the section data of length LEN from FILENAME starting at
+OFFSET.  The data segment must be freed by the caller when the
+caller is finished.  Returns NULL if all was not well.  */
+static char *
+lto_read_section_data (struct lto_file_decl_data *file_data,
+		       intptr_t offset, size_t len)
+{
+char *result;
+static int fd = -1;
+static char *fd_name;
+#if LTO_MMAP_IO
+intptr_t computed_len;
+intptr_t computed_offset;
+intptr_t diff;
+#endif
+/* Keep a single-entry file-descriptor cache.  The last file we
+touched will get closed at exit.
+???  Eventually we want to add a more sophisticated larger cache
+or rather fix function body streaming to not stream them in
+practically random order.  */
+if (fd != -1
+&& filename_cmp (fd_name, file_data->file_name) != 0)
+{
+free (fd_name);
+close (fd);
+fd = -1;
+}
+if (fd == -1)
+{
+fd = open (file_data->file_name, O_RDONLY|O_BINARY);
+if (fd == -1)
+	{
+	  fatal_error (input_location, "Cannot open %s", file_data->file_name);
+	  return NULL;
+	}
+fd_name = xstrdup (file_data->file_name);
+}
+#if LTO_MMAP_IO
+if (!page_mask)
+{
+size_t page_size = sysconf (_SC_PAGE_SIZE);
+page_mask = ~(page_size - 1);
+}
+computed_offset = offset & page_mask;
+diff = offset - computed_offset;
+computed_len = len + diff;
+result = (char *) mmap (NULL, computed_len, PROT_READ, MAP_PRIVATE,
+			  fd, computed_offset);
+if (result == MAP_FAILED)
+{
+fatal_error (input_location, "Cannot map %s", file_data->file_name);
+return NULL;
+}
+return result + diff;
+#else
+result = (char *) xmalloc (len);
+if (lseek (fd, offset, SEEK_SET) != offset
+|| read (fd, result, len) != (ssize_t) len)
+{
+free (result);
+fatal_error (input_location, "Cannot read %s", file_data->file_name);
+result = NULL;
+}
+#ifdef __MINGW32__
+/* Native windows doesn't supports delayed unlink on opened file.  So
+we close file here again.  This produces higher I/O load, but at least
+it prevents to have dangling file handles preventing unlink.  */
+free (fd_name);
+fd_name = NULL;
+close (fd);
+fd = -1;
+#endif
+return result;
+#endif
+}
+/* Get the section data from FILE_DATA of SECTION_TYPE with NAME.
+NAME will be NULL unless the section type is for a function
+body.  */
+static const char *
+get_section_data (struct lto_file_decl_data *file_data,
+		  enum lto_section_type section_type,
+		  const char *name, int order,
+		  size_t *len)
+{
+htab_t section_hash_table = file_data->section_hash_table;
+struct lto_section_slot *f_slot;
+struct lto_section_slot s_slot;
+const char *section_name = lto_get_section_name (section_type, name,
+						   order, file_data);
+char *data = NULL;
+*len = 0;
+s_slot.name = section_name;
+f_slot = (struct lto_section_slot *) htab_find (section_hash_table, &s_slot);
+if (f_slot)
+{
+data = lto_read_section_data (file_data, f_slot->start, f_slot->len);
+*len = f_slot->len;
+}
+free (CONST_CAST (char *, section_name));
+return data;
+}
+/* Free the section data from FILE_DATA of SECTION_TYPE with NAME that
+starts at OFFSET and has LEN bytes.  */
+static void
+free_section_data (struct lto_file_decl_data *file_data ATTRIBUTE_UNUSED,
+		   enum lto_section_type section_type ATTRIBUTE_UNUSED,
+		   const char *name ATTRIBUTE_UNUSED,
+		   const char *offset, size_t len ATTRIBUTE_UNUSED)
+{
+#if LTO_MMAP_IO
+intptr_t computed_len;
+intptr_t computed_offset;
+intptr_t diff;
+#endif
+#if LTO_MMAP_IO
+computed_offset = ((intptr_t) offset) & page_mask;
+diff = (intptr_t) offset - computed_offset;
+computed_len = len + diff;
+munmap ((caddr_t) computed_offset, computed_len);
+#else
+free (CONST_CAST(char *, offset));
+#endif
+}
+static lto_file *current_lto_file;
+/* If TT is a variable or function decl replace it with its
+prevailing variant.  */
+#define LTO_SET_PREVAIL(tt) \
+do {\
+if ((tt) && VAR_OR_FUNCTION_DECL_P (tt) \
+	&& (TREE_PUBLIC (tt) || DECL_EXTERNAL (tt))) \
+{ \
+	tt = lto_symtab_prevailing_decl (tt); \
+	fixed = true; \
+} \
+} while (0)
+/* Ensure that TT isn't a replacable var of function decl.  */
+#define LTO_NO_PREVAIL(tt) \
+gcc_checking_assert (!(tt) || !VAR_OR_FUNCTION_DECL_P (tt))
+/* Given a tree T replace all fields referring to variables or functions
+with their prevailing variant.  */
+static void
+lto_fixup_prevailing_decls (tree t)
+{
+enum tree_code code = TREE_CODE (t);
+bool fixed = false;
+gcc_checking_assert (code != TREE_BINFO);
+LTO_NO_PREVAIL (TREE_TYPE (t));
+if (CODE_CONTAINS_STRUCT (code, TS_COMMON)
+/* lto_symtab_prevail_decl use TREE_CHAIN to link to the prevailing decl.
+	 in the case T is a prevailed declaration we would ICE here.  */
+&& !VAR_OR_FUNCTION_DECL_P (t))
+LTO_NO_PREVAIL (TREE_CHAIN (t));
+if (DECL_P (t))
+{
+LTO_NO_PREVAIL (DECL_NAME (t));
+LTO_SET_PREVAIL (DECL_CONTEXT (t));
+if (CODE_CONTAINS_STRUCT (code, TS_DECL_COMMON))
+	{
+	  LTO_SET_PREVAIL (DECL_SIZE (t));
+	  LTO_SET_PREVAIL (DECL_SIZE_UNIT (t));
+	  LTO_SET_PREVAIL (DECL_INITIAL (t));
+	  LTO_NO_PREVAIL (DECL_ATTRIBUTES (t));
+	  LTO_SET_PREVAIL (DECL_ABSTRACT_ORIGIN (t));
+	}
+if (CODE_CONTAINS_STRUCT (code, TS_DECL_WITH_VIS))
+	{
+	  LTO_NO_PREVAIL (DECL_ASSEMBLER_NAME_RAW (t));
+	}
+if (CODE_CONTAINS_STRUCT (code, TS_DECL_NON_COMMON))
+	{
+	  LTO_NO_PREVAIL (DECL_RESULT_FLD (t));
+	}
+if (CODE_CONTAINS_STRUCT (code, TS_FUNCTION_DECL))
+	{
+	  LTO_NO_PREVAIL (DECL_ARGUMENTS (t));
+	  LTO_SET_PREVAIL (DECL_FUNCTION_PERSONALITY (t));
+	  LTO_NO_PREVAIL (DECL_VINDEX (t));
+	}
+if (CODE_CONTAINS_STRUCT (code, TS_FIELD_DECL))
+	{
+	  LTO_SET_PREVAIL (DECL_FIELD_OFFSET (t));
+	  LTO_NO_PREVAIL (DECL_BIT_FIELD_TYPE (t));
+	  LTO_NO_PREVAIL (DECL_QUALIFIER (t));
+	  LTO_NO_PREVAIL (DECL_FIELD_BIT_OFFSET (t));
+	  LTO_NO_PREVAIL (DECL_FCONTEXT (t));
+	}
+}
+else if (TYPE_P (t))
+{
+LTO_NO_PREVAIL (TYPE_CACHED_VALUES (t));
+LTO_SET_PREVAIL (TYPE_SIZE (t));
+LTO_SET_PREVAIL (TYPE_SIZE_UNIT (t));
+LTO_NO_PREVAIL (TYPE_ATTRIBUTES (t));
+LTO_NO_PREVAIL (TYPE_NAME (t));
+LTO_SET_PREVAIL (TYPE_MIN_VALUE_RAW (t));
+LTO_SET_PREVAIL (TYPE_MAX_VALUE_RAW (t));
+LTO_NO_PREVAIL (TYPE_LANG_SLOT_1 (t));
+LTO_SET_PREVAIL (TYPE_CONTEXT (t));
+LTO_NO_PREVAIL (TYPE_CANONICAL (t));
+LTO_NO_PREVAIL (TYPE_MAIN_VARIANT (t));
+LTO_NO_PREVAIL (TYPE_NEXT_VARIANT (t));
+}
+else if (EXPR_P (t))
+{
+int i;
+for (i = TREE_OPERAND_LENGTH (t) - 1; i >= 0; --i)
+	LTO_SET_PREVAIL (TREE_OPERAND (t, i));
+}
+else if (TREE_CODE (t) == CONSTRUCTOR)
+{
+unsigned i;
+tree val;
+FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (t), i, val)
+	LTO_SET_PREVAIL (val);
+}
+else
+{
+switch (code)
+	{
+	case TREE_LIST:
+	  LTO_SET_PREVAIL (TREE_VALUE (t));
+	  LTO_SET_PREVAIL (TREE_PURPOSE (t));
+	  LTO_NO_PREVAIL (TREE_PURPOSE (t));
+	  break;
+	default:
+	  gcc_unreachable ();
+	}
+}
+/* If we fixed nothing, then we missed something seen by
+mentions_vars_p.  */
+gcc_checking_assert (fixed);
+}
+#undef LTO_SET_PREVAIL
+#undef LTO_NO_PREVAIL
+/* Helper function of lto_fixup_decls.  Walks the var and fn streams in STATE,
+replaces var and function decls with the corresponding prevailing def.  */
+static void
+lto_fixup_state (struct lto_in_decl_state *state)
+{
+unsigned i, si;
+/* Although we only want to replace FUNCTION_DECLs and VAR_DECLs,
+we still need to walk from all DECLs to find the reachable
+FUNCTION_DECLs and VAR_DECLs.  */
+for (si = 0; si < LTO_N_DECL_STREAMS; si++)
+{
+vec<tree, va_gc> *trees = state->streams[si];
+for (i = 0; i < vec_safe_length (trees); i++)
+	{
+	  tree t = (*trees)[i];
+	  if (flag_checking && TYPE_P (t))
+	    verify_type (t);
+	  if (VAR_OR_FUNCTION_DECL_P (t)
+	      && (TREE_PUBLIC (t) || DECL_EXTERNAL (t)))
+	    (*trees)[i] = lto_symtab_prevailing_decl (t);
+	}
+}
+}
+/* Fix the decls from all FILES.  Replaces each decl with the corresponding
+prevailing one.  */
+static void
+lto_fixup_decls (struct lto_file_decl_data **files)
+{
+unsigned int i;
+tree t;
+if (tree_with_vars)
+FOR_EACH_VEC_ELT ((*tree_with_vars), i, t)
+lto_fixup_prevailing_decls (t);
+for (i = 0; files[i]; i++)
+{
+struct lto_file_decl_data *file = files[i];
+struct lto_in_decl_state *state = file->global_decl_state;
+lto_fixup_state (state);
+hash_table<decl_state_hasher>::iterator iter;
+lto_in_decl_state *elt;
+FOR_EACH_HASH_TABLE_ELEMENT (*file->function_decl_states, elt,
+				   lto_in_decl_state *, iter)
+	lto_fixup_state (elt);
+}
+}
+static GTY((length ("lto_stats.num_input_files + 1"))) struct lto_file_decl_data **all_file_decl_data;
+/* Turn file datas for sub files into a single array, so that they look
+like separate files for further passes.  */
+static void
+lto_flatten_files (struct lto_file_decl_data **orig, int count,
+		   int last_file_ix)
+{
+struct lto_file_decl_data *n, *next;
+int i, k;
+lto_stats.num_input_files = count;
+all_file_decl_data
+= ggc_cleared_vec_alloc<lto_file_decl_data_ptr> (count + 1);
+/* Set the hooks so that all of the ipa passes can read in their data.  */
+lto_set_in_hooks (all_file_decl_data, get_section_data, free_section_data);
+for (i = 0, k = 0; i < last_file_ix; i++)
+{
+for (n = orig[i]; n != NULL; n = next)
+	{
+	  all_file_decl_data[k++] = n;
+	  next = n->next;
+	  n->next = NULL;
+	}
+}
+all_file_decl_data[k] = NULL;
+gcc_assert (k == count);
+}
+/* Input file data before flattening (i.e. splitting them to subfiles to support
+incremental linking.  */
+static int real_file_count;
+static GTY((length ("real_file_count + 1"))) struct lto_file_decl_data **real_file_decl_data;
+/* Read all the symbols from the input files FNAMES.  NFILES is the
+number of files requested in the command line.  Instantiate a
+global call graph by aggregating all the sub-graphs found in each
+file.  */
+void
+read_cgraph_and_symbols (unsigned nfiles, const char **fnames)
+{
+unsigned int i, last_file_ix;
+FILE *resolution;
+int count = 0;
+struct lto_file_decl_data **decl_data;
+symtab_node *snode;
+symtab->initialize ();
+timevar_push (TV_IPA_LTO_DECL_IN);
+#ifdef ACCEL_COMPILER
+section_name_prefix = OFFLOAD_SECTION_NAME_PREFIX;
+lto_stream_offload_p = true;
+#endif
+real_file_decl_data
+= decl_data = ggc_cleared_vec_alloc<lto_file_decl_data_ptr> (nfiles + 1);
+real_file_count = nfiles;
+/* Read the resolution file.  */
+resolution = NULL;
+if (resolution_file_name)
+{
+int t;
+unsigned num_objects;
+resolution = fopen (resolution_file_name, "r");
+if (resolution == NULL)
+	fatal_error (input_location,
+		     "could not open symbol resolution file: %m");
+t = fscanf (resolution, "%u", &num_objects);
+gcc_assert (t == 1);
+/* True, since the plugin splits the archives.  */
+gcc_assert (num_objects == nfiles);
+}
+symtab->state = LTO_STREAMING;
+canonical_type_hash_cache = new hash_map<const_tree, hashval_t> (251);
+gimple_canonical_types = htab_create (16381, gimple_canonical_type_hash,
+					gimple_canonical_type_eq, NULL);
+gcc_obstack_init (&tree_scc_hash_obstack);
+tree_scc_hash = new hash_table<tree_scc_hasher> (4096);
+/* Register the common node types with the canonical type machinery so
+we properly share alias-sets across languages and TUs.  Do not
+expose the common nodes as type merge target - those that should be
+are already exposed so by pre-loading the LTO streamer caches.
+Do two passes - first clear TYPE_CANONICAL and then re-compute it.  */
+for (i = 0; i < itk_none; ++i)
+lto_register_canonical_types (integer_types[i], true);
+for (i = 0; i < stk_type_kind_last; ++i)
+lto_register_canonical_types (sizetype_tab[i], true);
+for (i = 0; i < TI_MAX; ++i)
+lto_register_canonical_types (global_trees[i], true);
+for (i = 0; i < itk_none; ++i)
+lto_register_canonical_types (integer_types[i], false);
+for (i = 0; i < stk_type_kind_last; ++i)
+lto_register_canonical_types (sizetype_tab[i], false);
+for (i = 0; i < TI_MAX; ++i)
+lto_register_canonical_types (global_trees[i], false);
+if (!quiet_flag)
+fprintf (stderr, "Reading object files:");
+/* Read all of the object files specified on the command line.  */
+for (i = 0, last_file_ix = 0; i < nfiles; ++i)
+{
+struct lto_file_decl_data *file_data = NULL;
+if (!quiet_flag)
+	{
+	  fprintf (stderr, " %s", fnames[i]);
+	  fflush (stderr);
+	}
+current_lto_file = lto_obj_file_open (fnames[i], false);
+if (!current_lto_file)
+	break;
+file_data = lto_file_read (current_lto_file, resolution, &count);
+if (!file_data)
+	{
+	  lto_obj_file_close (current_lto_file);
+	  free (current_lto_file);
+	  current_lto_file = NULL;
+	  break;
+	}
+decl_data[last_file_ix++] = file_data;
+lto_obj_file_close (current_lto_file);
+free (current_lto_file);
+current_lto_file = NULL;
+}
+lto_flatten_files (decl_data, count, last_file_ix);
+lto_stats.num_input_files = count;
+ggc_free(decl_data);
+real_file_decl_data = NULL;
+lto_register_canonical_types_for_odr_types ();
+if (resolution_file_name)
+fclose (resolution);
+/* Show the LTO report before launching LTRANS.  */
+if (flag_lto_report || (flag_wpa && flag_lto_report_wpa))
+print_lto_report_1 ();
+/* Free gimple type merging datastructures.  */
+delete tree_scc_hash;
+tree_scc_hash = NULL;
+obstack_free (&tree_scc_hash_obstack, NULL);
+htab_delete (gimple_canonical_types);
+gimple_canonical_types = NULL;
+delete canonical_type_hash_cache;
+canonical_type_hash_cache = NULL;
+/* At this stage we know that majority of GGC memory is reachable.
+Growing the limits prevents unnecesary invocation of GGC.  */
+ggc_grow ();
+report_heap_memory_use ();
+/* Set the hooks so that all of the ipa passes can read in their data.  */
+lto_set_in_hooks (all_file_decl_data, get_section_data, free_section_data);
+timevar_pop (TV_IPA_LTO_DECL_IN);
+if (!quiet_flag)
+fprintf (stderr, "\nReading the symbol table:");
+timevar_push (TV_IPA_LTO_CGRAPH_IO);
+/* Read the symtab.  */
+input_symtab ();
+input_offload_tables (!flag_ltrans);
+/* Store resolutions into the symbol table.  */
+FOR_EACH_SYMBOL (snode)
+if (snode->externally_visible && snode->real_symbol_p ()
+	&& snode->lto_file_data && snode->lto_file_data->resolution_map
+	&& !(TREE_CODE (snode->decl) == FUNCTION_DECL
+	     && fndecl_built_in_p (snode->decl))
+	&& !(VAR_P (snode->decl) && DECL_HARD_REGISTER (snode->decl)))
+{
+	ld_plugin_symbol_resolution_t *res;
+	res = snode->lto_file_data->resolution_map->get (snode->decl);
+	if (!res || *res == LDPR_UNKNOWN)
+	  {
+	    if (snode->output_to_lto_symbol_table_p ())
+	      fatal_error (input_location, "missing resolution data for %s",
+			   IDENTIFIER_POINTER
+			     (DECL_ASSEMBLER_NAME (snode->decl)));
+	  }
+	/* Symbol versions are always used externally, but linker does not
+	   report that correctly.
+	   This is binutils PR25924.  */
+	else if (snode->symver && *res == LDPR_PREVAILING_DEF_IRONLY)
+	  snode->resolution = LDPR_PREVAILING_DEF_IRONLY_EXP;
+	else
+	  snode->resolution = *res;
+}
+for (i = 0; all_file_decl_data[i]; i++)
+if (all_file_decl_data[i]->resolution_map)
+{
+	delete all_file_decl_data[i]->resolution_map;
+	all_file_decl_data[i]->resolution_map = NULL;
+}
+timevar_pop (TV_IPA_LTO_CGRAPH_IO);
+if (!quiet_flag)
+fprintf (stderr, "\nMerging declarations:");
+timevar_push (TV_IPA_LTO_DECL_MERGE);
+/* Merge global decls.  In ltrans mode we read merged cgraph, we do not
+need to care about resolving symbols again, we only need to replace
+duplicated declarations read from the callgraph and from function
+sections.  */
+if (!flag_ltrans)
+{
+lto_symtab_merge_decls ();
+/* If there were errors during symbol merging bail out, we have no
+	 good way to recover here.  */
+if (seen_error ())
+	fatal_error (input_location,
+		     "errors during merging of translation units");
+/* Fixup all decls.  */
+lto_fixup_decls (all_file_decl_data);
+}
+if (tree_with_vars)
+ggc_free (tree_with_vars);
+tree_with_vars = NULL;
+/* During WPA we want to prevent ggc collecting by default.  Grow limits
+until after the IPA summaries are streamed in.  Basically all IPA memory
+is explcitly managed by ggc_free and ggc collect is not useful.
+Exception are the merged declarations.  */
+ggc_grow ();
+report_heap_memory_use ();
+timevar_pop (TV_IPA_LTO_DECL_MERGE);
+/* Each pass will set the appropriate timer.  */
+if (!quiet_flag)
+fprintf (stderr, "\nReading summaries:");
+/* Read the IPA summary data.  */
+if (flag_ltrans)
+ipa_read_optimization_summaries ();
+else
+ipa_read_summaries ();
+ggc_grow ();
+for (i = 0; all_file_decl_data[i]; i++)
+{
+gcc_assert (all_file_decl_data[i]->symtab_node_encoder);
+lto_symtab_encoder_delete (all_file_decl_data[i]->symtab_node_encoder);
+all_file_decl_data[i]->symtab_node_encoder = NULL;
+lto_in_decl_state *global_decl_state
+	= all_file_decl_data[i]->global_decl_state;
+lto_free_function_in_decl_state (global_decl_state);
+all_file_decl_data[i]->global_decl_state = NULL;
+all_file_decl_data[i]->current_decl_state = NULL;
+}
+if (!flag_ltrans)
+{
+/* Finally merge the cgraph according to the decl merging decisions.  */
+timevar_push (TV_IPA_LTO_CGRAPH_MERGE);
+if (!quiet_flag)
+	fprintf (stderr, "\nMerging symbols:");
+gcc_assert (!dump_file);
+dump_file = dump_begin (lto_link_dump_id, NULL);
+if (dump_file)
+	{
+	  fprintf (dump_file, "Before merging:\n");
+	  symtab->dump (dump_file);
+	}
+lto_symtab_merge_symbols ();
+/* Removal of unreachable symbols is needed to make verify_symtab to pass;
+	 we are still having duplicated comdat groups containing local statics.
+	 We could also just remove them while merging.  */
+symtab->remove_unreachable_nodes (dump_file);
+ggc_collect ();
+report_heap_memory_use ();
+if (dump_file)
+	dump_end (lto_link_dump_id, dump_file);
+dump_file = NULL;
+timevar_pop (TV_IPA_LTO_CGRAPH_MERGE);
+}
+symtab->state = IPA_SSA;
+/* All node removals happening here are useless, because
+WPA should not stream them.  Still always perform remove_unreachable_nodes
+because we may reshape clone tree, get rid of dead masters of inline
+clones and remove symbol entries for read-only variables we keep around
+only to be able to constant fold them.  */
+if (flag_ltrans)
+{
+if (symtab->dump_file)
+	 symtab->dump (symtab->dump_file);
+symtab->remove_unreachable_nodes (symtab->dump_file);
+}
+/* Indicate that the cgraph is built and ready.  */
+symtab->function_flags_ready = true;
+ggc_free (all_file_decl_data);
+all_file_decl_data = NULL;
+}
+/* Show various memory usage statistics related to LTO.  */
+void
+print_lto_report_1 (void)
+{
+const char *pfx = (flag_lto) ? "LTO" : (flag_wpa) ? "WPA" : "LTRANS";
+fprintf (stderr, "%s statistics\n", pfx);
+fprintf (stderr, "[%s] read %lu SCCs of average size %f\n",
+	   pfx, num_sccs_read, total_scc_size / (double)num_sccs_read);
+fprintf (stderr, "[%s] %lu tree bodies read in total\n", pfx, total_scc_size);
+if (flag_wpa && tree_scc_hash)
+{
+fprintf (stderr, "[%s] tree SCC table: size %ld, %ld elements, "
+	       "collision ratio: %f\n", pfx,
+	       (long) tree_scc_hash->size (),
+	       (long) tree_scc_hash->elements (),
+	       tree_scc_hash->collisions ());
+hash_table<tree_scc_hasher>::iterator hiter;
+tree_scc *scc, *max_scc = NULL;
+unsigned max_length = 0;
+FOR_EACH_HASH_TABLE_ELEMENT (*tree_scc_hash, scc, x, hiter)
+	{
+	  unsigned length = 0;
+	  tree_scc *s = scc;
+	  for (; s; s = s->next)
+	    length++;
+	  if (length > max_length)
+	    {
+	      max_length = length;
+	      max_scc = scc;
+	    }
+	}
+fprintf (stderr, "[%s] tree SCC max chain length %u (size %u)\n",
+	       pfx, max_length, max_scc->len);
+fprintf (stderr, "[%s] Compared %lu SCCs, %lu collisions (%f)\n", pfx,
+	       num_scc_compares, num_scc_compare_collisions,
+	       num_scc_compare_collisions / (double) num_scc_compares);
+fprintf (stderr, "[%s] Merged %lu SCCs\n", pfx, num_sccs_merged);
+fprintf (stderr, "[%s] Merged %lu tree bodies\n", pfx,
+	       total_scc_size_merged);
+fprintf (stderr, "[%s] Merged %lu types\n", pfx, num_merged_types);
+fprintf (stderr, "[%s] %lu types prevailed (%lu associated trees)\n",
+	       pfx, num_prevailing_types, num_type_scc_trees);
+fprintf (stderr, "[%s] GIMPLE canonical type table: size %ld, "
+	       "%ld elements, %ld searches, %ld collisions (ratio: %f)\n", pfx,
+	       (long) htab_size (gimple_canonical_types),
+	       (long) htab_elements (gimple_canonical_types),
+	       (long) gimple_canonical_types->searches,
+	       (long) gimple_canonical_types->collisions,
+	       htab_collisions (gimple_canonical_types));
+fprintf (stderr, "[%s] GIMPLE canonical type pointer-map: "
+	       "%lu elements, %ld searches\n", pfx,
+	       num_canonical_type_hash_entries,
+	       num_canonical_type_hash_queries);
+}
+print_lto_report (pfx);
+}
+GTY(()) tree lto_eh_personality_decl;
+/* Return the LTO personality function decl.  */
+tree
+lto_eh_personality (void)
+{
+if (!lto_eh_personality_decl)
+{
+/* Use the first personality DECL for our personality if we don't
+	 support multiple ones.  This ensures that we don't artificially
+	 create the need for them in a single-language program.  */
+if (first_personality_decl && !dwarf2out_do_cfi_asm ())
+	lto_eh_personality_decl = first_personality_decl;
+else
+	lto_eh_personality_decl = lhd_gcc_personality ();
+}
+return lto_eh_personality_decl;
+}
+/* Set the process name based on the LTO mode.  */
+static void
+lto_process_name (void)
+{
+if (flag_lto)
+setproctitle (flag_incremental_link == INCREMENTAL_LINK_LTO
+		  ? "lto1-inclink" : "lto1-lto");
+if (flag_wpa)
+setproctitle ("lto1-wpa");
+if (flag_ltrans)
+setproctitle ("lto1-ltrans");
+}
+/* Initialize the LTO front end.  */
+void
+lto_fe_init (void)
+{
+lto_process_name ();
+lto_streamer_hooks_init ();
+lto_reader_init ();
+lto_set_in_hooks (NULL, get_section_data, free_section_data);
+memset (&lto_stats, 0, sizeof (lto_stats));
+bitmap_obstack_initialize (NULL);
+gimple_register_cfg_hooks ();
+#ifndef ACCEL_COMPILER
+unsigned char *table
+= ggc_vec_alloc<unsigned char> (MAX_MACHINE_MODE);
+for (int m = 0; m < MAX_MACHINE_MODE; m++)
+table[m] = m;
+lto_mode_identity_table = table;
+#endif
+}
+#include "gt-lto-lto-common.h"

Mercurial > hg > CbC > CbC_gcc

comparison gcc/lto/lto-common.c @ 145:1830386684a0