/* Top-level LTO routines. Copyright 2009, 2010, 2011 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 . */ #include "config.h" #include "system.h" #include "coretypes.h" #include "opts.h" #include "toplev.h" #include "tree.h" #include "tree-flow.h" #include "diagnostic-core.h" #include "tm.h" #include "cgraph.h" #include "ggc.h" #include "tree-ssa-operands.h" #include "tree-pass.h" #include "langhooks.h" #include "vec.h" #include "bitmap.h" #include "pointer-set.h" #include "ipa-prop.h" #include "common.h" #include "debug.h" #include "timevar.h" #include "gimple.h" #include "lto.h" #include "lto-tree.h" #include "lto-streamer.h" #include "tree-streamer.h" #include "splay-tree.h" #include "params.h" #include "ipa-inline.h" #include "ipa-utils.h" static GTY(()) tree first_personality_decl; /* 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); } /* Read the constructors and inits. */ static void lto_materialize_constructors_and_inits (struct lto_file_decl_data * file_data) { size_t len; const char *data = lto_get_section_data (file_data, LTO_section_static_initializer, NULL, &len); lto_input_constructors_and_inits (file_data, data); lto_free_section_data (file_data, LTO_section_static_initializer, NULL, data, len); } /* Return true when NODE has a clone that is analyzed (i.e. we need to load its body even if the node itself is not needed). */ static bool has_analyzed_clone_p (struct cgraph_node *node) { struct cgraph_node *orig = node; node = node->clones; if (node) while (node != orig) { if (node->analyzed) return true; if (node->clones) node = node->clones; else if (node->next_sibling_clone) node = node->next_sibling_clone; else { while (node != orig && !node->next_sibling_clone) node = node->clone_of; if (node != orig) node = node->next_sibling_clone; } } return false; } /* Read the function body for the function associated with NODE. */ static void lto_materialize_function (struct cgraph_node *node) { tree decl; struct lto_file_decl_data *file_data; const char *data, *name; size_t len; decl = node->decl; /* Read in functions with body (analyzed nodes) and also functions that are needed to produce virtual clones. */ if (cgraph_function_with_gimple_body_p (node) || has_analyzed_clone_p (node)) { /* Clones and thunks don't need to be read. */ if (node->clone_of) return; /* Load the function body only if not operating in WPA mode. In WPA mode, the body of the function is not needed. */ if (!flag_wpa) { file_data = node->local.lto_file_data; name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl)); /* We may have renamed the declaration, e.g., a static function. */ name = lto_get_decl_name_mapping (file_data, name); data = lto_get_section_data (file_data, LTO_section_function_body, name, &len); if (!data) fatal_error ("%s: section %s is missing", file_data->file_name, name); gcc_assert (DECL_STRUCT_FUNCTION (decl) == NULL); allocate_struct_function (decl, false); announce_function (decl); lto_input_function_body (file_data, decl, data); if (DECL_FUNCTION_PERSONALITY (decl) && !first_personality_decl) first_personality_decl = DECL_FUNCTION_PERSONALITY (decl); lto_stats.num_function_bodies++; lto_free_section_data (file_data, LTO_section_function_body, name, data, len); ggc_collect (); } } /* Let the middle end know about the function. */ rest_of_decl_compilation (decl, 1, 0); } /* 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 (struct 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++; decl = streamer_tree_cache_get (data_in->reader_cache, ix); if (TREE_CODE (decl) != FUNCTION_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++; tree *decls = ggc_alloc_vec_tree (size); for (j = 0; j < size; j++) decls[j] = streamer_tree_cache_get (data_in->reader_cache, data[j]); state->streams[i].size = size; state->streams[i].trees = decls; data += size; } return data; } /* A hashtable of trees that potentially refer to variables or functions that must be replaced with their prevailing variant. */ static GTY((if_marked ("ggc_marked_p"), param_is (union tree_node))) htab_t tree_with_vars; /* Remember that T is a tree that (potentially) refers to a variable or function decl that may be replaced with its prevailing variant. */ static void remember_with_vars (tree t) { *(tree *) htab_find_slot (tree_with_vars, t, INSERT) = t; } #define GIMPLE_REGISTER_TYPE(tt) \ (TREE_VISITED (tt) ? gimple_register_type (tt) : tt) #define LTO_FIXUP_TREE(tt) \ do \ { \ if (tt) \ { \ if (TYPE_P (tt)) \ (tt) = GIMPLE_REGISTER_TYPE (tt); \ if (VAR_OR_FUNCTION_DECL_P (tt) && TREE_PUBLIC (tt)) \ remember_with_vars (t); \ } \ } while (0) static void lto_fixup_types (tree); /* Fix up fields of a tree_typed T. */ static void lto_ft_typed (tree t) { LTO_FIXUP_TREE (TREE_TYPE (t)); } /* Fix up fields of a tree_common T. */ static void lto_ft_common (tree t) { lto_ft_typed (t); LTO_FIXUP_TREE (TREE_CHAIN (t)); } /* Fix up fields of a decl_minimal T. */ static void lto_ft_decl_minimal (tree t) { lto_ft_common (t); LTO_FIXUP_TREE (DECL_NAME (t)); LTO_FIXUP_TREE (DECL_CONTEXT (t)); } /* Fix up fields of a decl_common T. */ static void lto_ft_decl_common (tree t) { lto_ft_decl_minimal (t); LTO_FIXUP_TREE (DECL_SIZE (t)); LTO_FIXUP_TREE (DECL_SIZE_UNIT (t)); LTO_FIXUP_TREE (DECL_INITIAL (t)); LTO_FIXUP_TREE (DECL_ATTRIBUTES (t)); LTO_FIXUP_TREE (DECL_ABSTRACT_ORIGIN (t)); } /* Fix up fields of a decl_with_vis T. */ static void lto_ft_decl_with_vis (tree t) { lto_ft_decl_common (t); /* Accessor macro has side-effects, use field-name here. */ LTO_FIXUP_TREE (t->decl_with_vis.assembler_name); LTO_FIXUP_TREE (DECL_SECTION_NAME (t)); } /* Fix up fields of a decl_non_common T. */ static void lto_ft_decl_non_common (tree t) { lto_ft_decl_with_vis (t); LTO_FIXUP_TREE (DECL_ARGUMENT_FLD (t)); LTO_FIXUP_TREE (DECL_RESULT_FLD (t)); LTO_FIXUP_TREE (DECL_VINDEX (t)); /* The C frontends may create exact duplicates for DECL_ORIGINAL_TYPE like for 'typedef enum foo foo'. We have no way of avoiding to merge them and dwarf2out.c cannot deal with this, so fix this up by clearing DECL_ORIGINAL_TYPE in this case. */ if (TREE_CODE (t) == TYPE_DECL && DECL_ORIGINAL_TYPE (t) == TREE_TYPE (t)) DECL_ORIGINAL_TYPE (t) = NULL_TREE; } /* Fix up fields of a decl_non_common T. */ static void lto_ft_function (tree t) { lto_ft_decl_non_common (t); LTO_FIXUP_TREE (DECL_FUNCTION_PERSONALITY (t)); } /* Fix up fields of a field_decl T. */ static void lto_ft_field_decl (tree t) { lto_ft_decl_common (t); LTO_FIXUP_TREE (DECL_FIELD_OFFSET (t)); LTO_FIXUP_TREE (DECL_BIT_FIELD_TYPE (t)); LTO_FIXUP_TREE (DECL_QUALIFIER (t)); LTO_FIXUP_TREE (DECL_FIELD_BIT_OFFSET (t)); LTO_FIXUP_TREE (DECL_FCONTEXT (t)); } /* Fix up fields of a type T. */ static void lto_ft_type (tree t) { lto_ft_common (t); LTO_FIXUP_TREE (TYPE_CACHED_VALUES (t)); LTO_FIXUP_TREE (TYPE_SIZE (t)); LTO_FIXUP_TREE (TYPE_SIZE_UNIT (t)); LTO_FIXUP_TREE (TYPE_ATTRIBUTES (t)); LTO_FIXUP_TREE (TYPE_NAME (t)); /* Accessors are for derived node types only. */ if (!POINTER_TYPE_P (t)) LTO_FIXUP_TREE (TYPE_MINVAL (t)); LTO_FIXUP_TREE (TYPE_MAXVAL (t)); /* Accessor is for derived node types only. */ LTO_FIXUP_TREE (t->type_non_common.binfo); LTO_FIXUP_TREE (TYPE_CONTEXT (t)); } /* Fix up fields of a BINFO T. */ static void lto_ft_binfo (tree t) { unsigned HOST_WIDE_INT i, n; tree base, saved_base; lto_ft_common (t); LTO_FIXUP_TREE (BINFO_VTABLE (t)); LTO_FIXUP_TREE (BINFO_OFFSET (t)); LTO_FIXUP_TREE (BINFO_VIRTUALS (t)); LTO_FIXUP_TREE (BINFO_VPTR_FIELD (t)); n = VEC_length (tree, BINFO_BASE_ACCESSES (t)); for (i = 0; i < n; i++) { saved_base = base = BINFO_BASE_ACCESS (t, i); LTO_FIXUP_TREE (base); if (base != saved_base) VEC_replace (tree, BINFO_BASE_ACCESSES (t), i, base); } LTO_FIXUP_TREE (BINFO_INHERITANCE_CHAIN (t)); LTO_FIXUP_TREE (BINFO_SUBVTT_INDEX (t)); LTO_FIXUP_TREE (BINFO_VPTR_INDEX (t)); n = BINFO_N_BASE_BINFOS (t); for (i = 0; i < n; i++) { saved_base = base = BINFO_BASE_BINFO (t, i); LTO_FIXUP_TREE (base); if (base != saved_base) VEC_replace (tree, BINFO_BASE_BINFOS (t), i, base); } } /* Fix up fields of a CONSTRUCTOR T. */ static void lto_ft_constructor (tree t) { unsigned HOST_WIDE_INT idx; constructor_elt *ce; lto_ft_typed (t); for (idx = 0; VEC_iterate(constructor_elt, CONSTRUCTOR_ELTS (t), idx, ce); idx++) { LTO_FIXUP_TREE (ce->index); LTO_FIXUP_TREE (ce->value); } } /* Fix up fields of an expression tree T. */ static void lto_ft_expr (tree t) { int i; lto_ft_typed (t); for (i = TREE_OPERAND_LENGTH (t) - 1; i >= 0; --i) LTO_FIXUP_TREE (TREE_OPERAND (t, i)); } /* Given a tree T fixup fields of T by replacing types with their merged variant and other entities by an equal entity from an earlier compilation unit, or an entity being canonical in a different way. This includes for instance integer or string constants. */ static void lto_fixup_types (tree t) { switch (TREE_CODE (t)) { case IDENTIFIER_NODE: break; case TREE_LIST: LTO_FIXUP_TREE (TREE_VALUE (t)); LTO_FIXUP_TREE (TREE_PURPOSE (t)); LTO_FIXUP_TREE (TREE_CHAIN (t)); break; case FIELD_DECL: lto_ft_field_decl (t); break; case LABEL_DECL: case CONST_DECL: case PARM_DECL: case RESULT_DECL: case IMPORTED_DECL: lto_ft_decl_common (t); break; case VAR_DECL: lto_ft_decl_with_vis (t); break; case TYPE_DECL: lto_ft_decl_non_common (t); break; case FUNCTION_DECL: lto_ft_function (t); break; case TREE_BINFO: lto_ft_binfo (t); break; case PLACEHOLDER_EXPR: lto_ft_common (t); break; case BLOCK: case TRANSLATION_UNIT_DECL: case OPTIMIZATION_NODE: case TARGET_OPTION_NODE: break; default: if (TYPE_P (t)) lto_ft_type (t); else if (TREE_CODE (t) == CONSTRUCTOR) lto_ft_constructor (t); else if (CONSTANT_CLASS_P (t)) LTO_FIXUP_TREE (TREE_TYPE (t)); else if (EXPR_P (t)) { lto_ft_expr (t); } else { remember_with_vars (t); } } } /* Return the resolution for the decl with index INDEX from DATA_IN. */ static enum ld_plugin_symbol_resolution get_resolution (struct data_in *data_in, unsigned index) { if (data_in->globals_resolution) { 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 (VEC_length (ld_plugin_symbol_resolution_t, data_in->globals_resolution) <= index) return LDPR_UNKNOWN; ret = VEC_index (ld_plugin_symbol_resolution_t, data_in->globals_resolution, index); return ret; } else /* Delay resolution finding until decl merging. */ return LDPR_UNKNOWN; } /* 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 (struct data_in *data_in, tree decl) { tree context; /* Variable has file scope, not local. Need to ensure static variables between different files don't clash unexpectedly. */ if (!TREE_PUBLIC (decl) && !((context = decl_function_context (decl)) && auto_var_in_fn_p (decl, context))) { /* ??? We normally pre-mangle names before we serialize them out. Here, in lto1, we do not know the language, and thus cannot do the mangling again. Instead, we just append a suffix to the mangled name. The resulting name, however, is not a properly-formed mangled name, and will confuse any attempt to unmangle it. */ const char *name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl)); char *label; ASM_FORMAT_PRIVATE_NAME (label, name, DECL_UID (decl)); SET_DECL_ASSEMBLER_NAME (decl, get_identifier (label)); rest_of_decl_compilation (decl, 1, 0); VEC_safe_push (tree, gc, lto_global_var_decls, decl); } /* If this variable has already been declared, queue the declaration for merging. */ if (TREE_PUBLIC (decl)) { unsigned ix; if (!streamer_tree_cache_lookup (data_in->reader_cache, decl, &ix)) gcc_unreachable (); lto_symtab_register_decl (decl, get_resolution (data_in, ix), data_in->file_data); } } /* 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 (struct data_in *data_in, tree decl) { /* Need to ensure static entities between different files don't clash unexpectedly. */ if (!TREE_PUBLIC (decl)) { /* We must not use the DECL_ASSEMBLER_NAME macro here, as it may set the assembler name where it was previously empty. */ tree old_assembler_name = decl->decl_with_vis.assembler_name; /* FIXME lto: We normally pre-mangle names before we serialize them out. Here, in lto1, we do not know the language, and thus cannot do the mangling again. Instead, we just append a suffix to the mangled name. The resulting name, however, is not a properly-formed mangled name, and will confuse any attempt to unmangle it. */ const char *name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl)); char *label; ASM_FORMAT_PRIVATE_NAME (label, name, DECL_UID (decl)); SET_DECL_ASSEMBLER_NAME (decl, get_identifier (label)); /* We may arrive here with the old assembler name not set if the function body is not needed, e.g., it has been inlined away and does not appear in the cgraph. */ if (old_assembler_name) { tree new_assembler_name = DECL_ASSEMBLER_NAME (decl); /* Make the original assembler name available for later use. We may have used it to indicate the section within its object file where the function body may be found. FIXME lto: Find a better way to maintain the function decl to body section mapping so we don't need this hack. */ lto_record_renamed_decl (data_in->file_data, IDENTIFIER_POINTER (old_assembler_name), IDENTIFIER_POINTER (new_assembler_name)); } } /* If this variable has already been declared, queue the declaration for merging. */ if (TREE_PUBLIC (decl) && !DECL_ABSTRACT (decl)) { unsigned ix; if (!streamer_tree_cache_lookup (data_in->reader_cache, decl, &ix)) gcc_unreachable (); lto_symtab_register_decl (decl, get_resolution (data_in, ix), data_in->file_data); } } /* Given a streamer cache structure DATA_IN (holding a sequence of trees for one compilation unit) go over all trees starting at index FROM until the end of the sequence and replace fields of those trees, and the trees themself with their canonical variants as per gimple_register_type. */ static void uniquify_nodes (struct data_in *data_in, unsigned from) { struct streamer_tree_cache_d *cache = data_in->reader_cache; unsigned len = VEC_length (tree, cache->nodes); unsigned i; /* Go backwards because children streamed for the first time come as part of their parents, and hence are created after them. */ /* First register all the types in the cache. This makes sure to have the original structure in the type cycles when registering them and computing hashes. */ for (i = len; i-- > from;) { tree t = VEC_index (tree, cache->nodes, i); if (t && TYPE_P (t)) { tree newt = gimple_register_type (t); /* Mark non-prevailing types so we fix them up. No need to reset that flag afterwards - nothing that refers to those types is left and they are collected. */ if (newt != t) TREE_VISITED (t) = 1; } } /* Second fixup all trees in the new cache entries. */ for (i = len; i-- > from;) { tree t = VEC_index (tree, cache->nodes, i); tree oldt = t; if (!t) continue; /* First fixup the fields of T. */ lto_fixup_types (t); if (!TYPE_P (t)) continue; /* Now try to find a canonical variant of T itself. */ t = GIMPLE_REGISTER_TYPE (t); if (t == oldt) { /* 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. */ tree tem, mv; /* Remove us from our main variant list if we are not the variant leader. */ if (TYPE_MAIN_VARIANT (t) != t) { tem = TYPE_MAIN_VARIANT (t); while (tem && TYPE_NEXT_VARIANT (tem) != t) tem = TYPE_NEXT_VARIANT (tem); if (tem) TYPE_NEXT_VARIANT (tem) = TYPE_NEXT_VARIANT (t); TYPE_NEXT_VARIANT (t) = NULL_TREE; } /* Query our new main variant. */ mv = GIMPLE_REGISTER_TYPE (TYPE_MAIN_VARIANT (t)); /* If we were the variant leader and we get replaced ourselves drop all variants from our list. */ if (TYPE_MAIN_VARIANT (t) == t && mv != t) { tem = t; while (tem) { tree tem2 = TYPE_NEXT_VARIANT (tem); TYPE_NEXT_VARIANT (tem) = NULL_TREE; tem = tem2; } } /* If we are not our own variant leader link us into our new leaders variant list. */ if (mv != t) { TYPE_NEXT_VARIANT (t) = TYPE_NEXT_VARIANT (mv); TYPE_NEXT_VARIANT (mv) = t; if (RECORD_OR_UNION_TYPE_P (t)) TYPE_BINFO (t) = TYPE_BINFO (mv); } /* Finally adjust our main variant and fix it up. */ TYPE_MAIN_VARIANT (t) = mv; /* 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; } } else { if (RECORD_OR_UNION_TYPE_P (t)) { tree f1, f2; if (TYPE_FIELDS (t) != TYPE_FIELDS (oldt)) for (f1 = TYPE_FIELDS (t), f2 = TYPE_FIELDS (oldt); f1 && f2; f1 = TREE_CHAIN (f1), f2 = TREE_CHAIN (f2)) { unsigned ix; gcc_assert (f1 != f2 && DECL_NAME (f1) == DECL_NAME (f2)); if (!streamer_tree_cache_lookup (cache, f2, &ix)) gcc_unreachable (); /* If we're going to replace an element which we'd still visit in the next iterations, we wouldn't handle it, so do it here. We do have to handle it even though the field_decl itself will be removed, as it could refer to e.g. integer_cst which we wouldn't reach via any other way, hence they (and their type) would stay uncollected. */ /* ??? We should rather make sure to replace all references to f2 with f1. That means handling COMPONENT_REFs and CONSTRUCTOR elements in lto_fixup_types and special-case the field-decl operand handling. */ if (ix < i) lto_fixup_types (f2); streamer_tree_cache_insert_at (cache, f1, ix); } } /* If we found a tree that is equal to oldt replace it in the cache, so that further users (in the various LTO sections) make use of it. */ streamer_tree_cache_insert_at (cache, t, i); } } /* Finally compute the canonical type of all TREE_TYPEs and register VAR_DECL and FUNCTION_DECL nodes in the symbol table. From this point there are no longer any types with TYPE_STRUCTURAL_EQUALITY_P and its type-based alias problems. This step requires the TYPE_POINTER_TO lists being present, so make sure it is done last. */ for (i = len; i-- > from;) { tree t = VEC_index (tree, cache->nodes, i); if (t == NULL_TREE) continue; if (TREE_CODE (t) == VAR_DECL) lto_register_var_decl_in_symtab (data_in, t); else if (TREE_CODE (t) == FUNCTION_DECL && !DECL_BUILT_IN (t)) lto_register_function_decl_in_symtab (data_in, t); else if (!flag_wpa && TREE_CODE (t) == TYPE_DECL) debug_hooks->type_decl (t, !DECL_FILE_SCOPE_P (t)); else if (TYPE_P (t) && !TYPE_CANONICAL (t)) TYPE_CANONICAL (t) = gimple_register_canonical_type (t); } } /* 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,heap) *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; struct lto_input_block ib_main; struct data_in *data_in; unsigned int i; const uint32_t *data_ptr, *data_end; uint32_t num_decl_states; LTO_INIT_INPUT_BLOCK (ib_main, (const char *) data + main_offset, 0, header->main_size); 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. */ /* Read the global declarations and types. */ while (ib_main.p < ib_main.len) { tree t; unsigned from = VEC_length (tree, data_in->reader_cache->nodes); t = stream_read_tree (&ib_main, data_in); gcc_assert (t && ib_main.p <= ib_main.len); uniquify_nodes (data_in, from); } /* 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 = htab_create_ggc (37, lto_hash_in_decl_state, lto_eq_in_decl_state, NULL); for (i = 1; i < num_decl_states; i++) { struct lto_in_decl_state *state = lto_new_in_decl_state (); void **slot; data_ptr = lto_read_in_decl_state (data_in, data_ptr, state); slot = htab_find_slot (decl_data->function_decl_states, 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 HOST_WIDEST_INT lto_parse_hex (const char *p) { HOST_WIDEST_INT 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]; HOST_WIDEST_INT 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 " HOST_WIDE_INT_PRINT_HEX_PURE " 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; VEC_safe_push (res_pair, heap, file_data->respairs, &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, LTO_SECTION_NAME_PREFIX, strlen (LTO_SECTION_NAME_PREFIX))) return 0; s = strrchr (name, '.'); return s && 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) { const char *data; size_t len; VEC(ld_plugin_symbol_resolution_t,heap) *resolutions = NULL; int i; res_pair *rp; /* Create vector for fast access of resolution. We do this lazily to save memory. */ VEC_safe_grow_cleared (ld_plugin_symbol_resolution_t, heap, resolutions, file_data->max_index + 1); for (i = 0; VEC_iterate (res_pair, file_data->respairs, i, rp); i++) VEC_replace (ld_plugin_symbol_resolution_t, resolutions, rp->index, rp->res); VEC_free (res_pair, heap, file_data->respairs); file_data->renaming_hash_table = lto_create_renaming_table (); file_data->file_name = file->filename; data = lto_get_section_data (file_data, LTO_section_decls, NULL, &len); if (data == NULL) { internal_error ("cannot read LTO 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) { lto_file_finalize (file_data, file); if (cgraph_dump_file) fprintf (cgraph_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 (§ion_list, 0, sizeof (struct lto_section_list)); section_hash_table = lto_obj_build_section_table (file, §ion_list); /* 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 */ for (file_data = file_list.first; file_data != NULL; file_data = file_data->next) lto_create_files_from_ids (file, file_data, count); 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 ("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 ("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 ("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, 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, 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 } /* Structure describing ltrans partitions. */ struct ltrans_partition_def { cgraph_node_set cgraph_set; varpool_node_set varpool_set; const char * name; int insns; }; typedef struct ltrans_partition_def *ltrans_partition; DEF_VEC_P(ltrans_partition); DEF_VEC_ALLOC_P(ltrans_partition,heap); static VEC(ltrans_partition, heap) *ltrans_partitions; static void add_cgraph_node_to_partition (ltrans_partition part, struct cgraph_node *node); static void add_varpool_node_to_partition (ltrans_partition part, struct varpool_node *vnode); /* Create new partition with name NAME. */ static ltrans_partition new_partition (const char *name) { ltrans_partition part = XCNEW (struct ltrans_partition_def); part->cgraph_set = cgraph_node_set_new (); part->varpool_set = varpool_node_set_new (); part->name = name; part->insns = 0; VEC_safe_push (ltrans_partition, heap, ltrans_partitions, part); return part; } /* Free memory used by ltrans datastructures. */ static void free_ltrans_partitions (void) { unsigned int idx; ltrans_partition part; for (idx = 0; VEC_iterate (ltrans_partition, ltrans_partitions, idx, part); idx++) { free_cgraph_node_set (part->cgraph_set); free (part); } VEC_free (ltrans_partition, heap, ltrans_partitions); } /* See all references that go to comdat objects and bring them into partition too. */ static void add_references_to_partition (ltrans_partition part, struct ipa_ref_list *refs) { int i; struct ipa_ref *ref; for (i = 0; ipa_ref_list_reference_iterate (refs, i, ref); i++) { if (ref->refered_type == IPA_REF_CGRAPH && DECL_COMDAT (cgraph_function_node (ipa_ref_node (ref), NULL)->decl) && !cgraph_node_in_set_p (ipa_ref_node (ref), part->cgraph_set)) add_cgraph_node_to_partition (part, ipa_ref_node (ref)); else if (ref->refered_type == IPA_REF_VARPOOL && DECL_COMDAT (ipa_ref_varpool_node (ref)->decl) && !varpool_node_in_set_p (ipa_ref_varpool_node (ref), part->varpool_set)) add_varpool_node_to_partition (part, ipa_ref_varpool_node (ref)); } } /* Worker for add_cgraph_node_to_partition. */ static bool add_cgraph_node_to_partition_1 (struct cgraph_node *node, void *data) { ltrans_partition part = (ltrans_partition) data; /* non-COMDAT aliases of COMDAT functions needs to be output just once. */ if (!DECL_COMDAT (node->decl) && !node->global.inlined_to && node->aux) { gcc_assert (node->thunk.thunk_p || node->alias); return false; } if (node->aux) { node->in_other_partition = 1; if (cgraph_dump_file) fprintf (cgraph_dump_file, "Node %s/%i now used in multiple partitions\n", cgraph_node_name (node), node->uid); } node->aux = (void *)((size_t)node->aux + 1); cgraph_node_set_add (part->cgraph_set, node); return false; } /* Add NODE to partition as well as the inline callees and referred comdats into partition PART. */ static void add_cgraph_node_to_partition (ltrans_partition part, struct cgraph_node *node) { struct cgraph_edge *e; cgraph_node_set_iterator csi; struct cgraph_node *n; /* We always decide on functions, not associated thunks and aliases. */ node = cgraph_function_node (node, NULL); /* If NODE is already there, we have nothing to do. */ csi = cgraph_node_set_find (part->cgraph_set, node); if (!csi_end_p (csi)) return; cgraph_for_node_thunks_and_aliases (node, add_cgraph_node_to_partition_1, part, true); part->insns += inline_summary (node)->self_size; cgraph_node_set_add (part->cgraph_set, node); for (e = node->callees; e; e = e->next_callee) if ((!e->inline_failed || DECL_COMDAT (cgraph_function_node (e->callee, NULL)->decl)) && !cgraph_node_in_set_p (e->callee, part->cgraph_set)) add_cgraph_node_to_partition (part, e->callee); add_references_to_partition (part, &node->ref_list); if (node->same_comdat_group) for (n = node->same_comdat_group; n != node; n = n->same_comdat_group) add_cgraph_node_to_partition (part, n); } /* Add VNODE to partition as well as comdat references partition PART. */ static void add_varpool_node_to_partition (ltrans_partition part, struct varpool_node *vnode) { varpool_node_set_iterator vsi; vnode = varpool_variable_node (vnode, NULL); /* If NODE is already there, we have nothing to do. */ vsi = varpool_node_set_find (part->varpool_set, vnode); if (!vsi_end_p (vsi)) return; varpool_node_set_add (part->varpool_set, vnode); if (vnode->aux) { vnode->in_other_partition = 1; if (cgraph_dump_file) fprintf (cgraph_dump_file, "Varpool node %s now used in multiple partitions\n", varpool_node_name (vnode)); } vnode->aux = (void *)((size_t)vnode->aux + 1); add_references_to_partition (part, &vnode->ref_list); if (vnode->same_comdat_group && !varpool_node_in_set_p (vnode->same_comdat_group, part->varpool_set)) add_varpool_node_to_partition (part, vnode->same_comdat_group); } /* Undo all additions until number of cgraph nodes in PARITION is N_CGRAPH_NODES and number of varpool nodes is N_VARPOOL_NODES. */ static void undo_partition (ltrans_partition partition, unsigned int n_cgraph_nodes, unsigned int n_varpool_nodes) { while (VEC_length (cgraph_node_ptr, partition->cgraph_set->nodes) > n_cgraph_nodes) { struct cgraph_node *node = VEC_index (cgraph_node_ptr, partition->cgraph_set->nodes, n_cgraph_nodes); partition->insns -= inline_summary (node)->self_size; cgraph_node_set_remove (partition->cgraph_set, node); node->aux = (void *)((size_t)node->aux - 1); } while (VEC_length (varpool_node_ptr, partition->varpool_set->nodes) > n_varpool_nodes) { struct varpool_node *node = VEC_index (varpool_node_ptr, partition->varpool_set->nodes, n_varpool_nodes); varpool_node_set_remove (partition->varpool_set, node); node->aux = (void *)((size_t)node->aux - 1); } } /* Return true if NODE should be partitioned. This means that partitioning algorithm should put NODE into one of partitions. This apply to most functions with bodies. Functions that are not partitions are put into every unit needing them. This is the case of i.e. COMDATs. */ static bool partition_cgraph_node_p (struct cgraph_node *node) { /* We will get proper partition based on function they are inlined to. */ if (node->global.inlined_to) return false; /* Nodes without a body do not need partitioning. */ if (!node->analyzed) return false; /* Extern inlines and comdat are always only in partitions they are needed. */ if (DECL_EXTERNAL (node->decl) || (DECL_COMDAT (node->decl) && !cgraph_used_from_object_file_p (node))) return false; if (lookup_attribute ("weakref", DECL_ATTRIBUTES (node->decl))) return false; return true; } /* Return true if VNODE should be partitioned. This means that partitioning algorithm should put VNODE into one of partitions. */ static bool partition_varpool_node_p (struct varpool_node *vnode) { if (vnode->alias || !vnode->needed) return false; /* Constant pool and comdat are always only in partitions they are needed. */ if (DECL_IN_CONSTANT_POOL (vnode->decl) || (DECL_COMDAT (vnode->decl) && !vnode->force_output && !varpool_used_from_object_file_p (vnode))) return false; if (lookup_attribute ("weakref", DECL_ATTRIBUTES (vnode->decl))) return false; return true; } /* Group cgrah nodes by input files. This is used mainly for testing right now. */ static void lto_1_to_1_map (void) { struct cgraph_node *node; struct varpool_node *vnode; struct lto_file_decl_data *file_data; struct pointer_map_t *pmap; ltrans_partition partition; void **slot; int npartitions = 0; timevar_push (TV_WHOPR_WPA); pmap = pointer_map_create (); for (node = cgraph_nodes; node; node = node->next) { if (!partition_cgraph_node_p (node) || node->aux) continue; file_data = node->local.lto_file_data; if (file_data) { slot = pointer_map_contains (pmap, file_data); if (slot) partition = (ltrans_partition) *slot; else { partition = new_partition (file_data->file_name); slot = pointer_map_insert (pmap, file_data); *slot = partition; npartitions++; } } else if (!file_data && VEC_length (ltrans_partition, ltrans_partitions)) partition = VEC_index (ltrans_partition, ltrans_partitions, 0); else { partition = new_partition (""); slot = pointer_map_insert (pmap, NULL); *slot = partition; npartitions++; } add_cgraph_node_to_partition (partition, node); } for (vnode = varpool_nodes; vnode; vnode = vnode->next) { if (!partition_varpool_node_p (vnode) || vnode->aux) continue; file_data = vnode->lto_file_data; slot = pointer_map_contains (pmap, file_data); if (slot) partition = (ltrans_partition) *slot; else { partition = new_partition (file_data->file_name); slot = pointer_map_insert (pmap, file_data); *slot = partition; npartitions++; } add_varpool_node_to_partition (partition, vnode); } for (node = cgraph_nodes; node; node = node->next) node->aux = NULL; for (vnode = varpool_nodes; vnode; vnode = vnode->next) vnode->aux = NULL; /* If the cgraph is empty, create one cgraph node set so that there is still an output file for any variables that need to be exported in a DSO. */ if (!npartitions) new_partition ("empty"); pointer_map_destroy (pmap); timevar_pop (TV_WHOPR_WPA); lto_stats.num_cgraph_partitions += VEC_length (ltrans_partition, ltrans_partitions); } /* Helper function for qsort; sort nodes by order. */ static int node_cmp (const void *pa, const void *pb) { const struct cgraph_node *a = *(const struct cgraph_node * const *) pa; const struct cgraph_node *b = *(const struct cgraph_node * const *) pb; return b->order - a->order; } /* Helper function for qsort; sort nodes by order. */ static int varpool_node_cmp (const void *pa, const void *pb) { const struct varpool_node *a = *(const struct varpool_node * const *) pa; const struct varpool_node *b = *(const struct varpool_node * const *) pb; return b->order - a->order; } /* Group cgraph nodes into equally-sized partitions. The partitioning algorithm is simple: nodes are taken in predefined order. The order corresponds to the order we want functions to have in the final output. In the future this will be given by function reordering pass, but at the moment we use the topological order, which is a good approximation. The goal is to partition this linear order into intervals (partitions) so that all the partitions have approximately the same size and the number of callgraph or IPA reference edges crossing boundaries is minimal. This is a lot faster (O(n) in size of callgraph) than algorithms doing priority-based graph clustering that are generally O(n^2) and, since WHOPR is designed to make things go well across partitions, it leads to good results. We compute the expected size of a partition as: max (total_size / lto_partitions, min_partition_size) We use dynamic expected size of partition so small programs are partitioned into enough partitions to allow use of multiple CPUs, while large programs are not partitioned too much. Creating too many partitions significantly increases the streaming overhead. In the future, we would like to bound the maximal size of partitions so as to prevent the LTRANS stage from consuming too much memory. At the moment, however, the WPA stage is the most memory intensive for large benchmarks, since too many types and declarations are read into memory. The function implements a simple greedy algorithm. Nodes are being added to the current partition until after 3/4 of the expected partition size is reached. Past this threshold, we keep track of boundary size (number of edges going to other partitions) and continue adding functions until after the current partition has grown to twice the expected partition size. Then the process is undone to the point where the minimal ratio of boundary size and in-partition calls was reached. */ static void lto_balanced_map (void) { int n_nodes = 0; int n_varpool_nodes = 0, varpool_pos = 0; struct cgraph_node **postorder = XCNEWVEC (struct cgraph_node *, cgraph_n_nodes); struct cgraph_node **order = XNEWVEC (struct cgraph_node *, cgraph_max_uid); struct varpool_node **varpool_order = NULL; int i, postorder_len; struct cgraph_node *node; int total_size = 0, best_total_size = 0; int partition_size; ltrans_partition partition; unsigned int last_visited_cgraph_node = 0, last_visited_varpool_node = 0; struct varpool_node *vnode; int cost = 0, internal = 0; int best_n_nodes = 0, best_n_varpool_nodes = 0, best_i = 0, best_cost = INT_MAX, best_internal = 0; int npartitions; int current_order = -1; for (vnode = varpool_nodes; vnode; vnode = vnode->next) gcc_assert (!vnode->aux); /* Until we have better ordering facility, use toplogical order. Include only nodes we will partition and compute estimate of program size. Note that since nodes that are not partitioned might be put into multiple partitions, this is just an estimate of real size. This is why we keep partition_size updated after every partition is finalized. */ postorder_len = ipa_reverse_postorder (postorder); for (i = 0; i < postorder_len; i++) { node = postorder[i]; if (partition_cgraph_node_p (node)) { order[n_nodes++] = node; total_size += inline_summary (node)->size; } } free (postorder); if (!flag_toplevel_reorder) { qsort (order, n_nodes, sizeof (struct cgraph_node *), node_cmp); for (vnode = varpool_nodes; vnode; vnode = vnode->next) if (partition_varpool_node_p (vnode)) n_varpool_nodes++; varpool_order = XNEWVEC (struct varpool_node *, n_varpool_nodes); n_varpool_nodes = 0; for (vnode = varpool_nodes; vnode; vnode = vnode->next) if (partition_varpool_node_p (vnode)) varpool_order[n_varpool_nodes++] = vnode; qsort (varpool_order, n_varpool_nodes, sizeof (struct varpool_node *), varpool_node_cmp); } /* Compute partition size and create the first partition. */ partition_size = total_size / PARAM_VALUE (PARAM_LTO_PARTITIONS); if (partition_size < PARAM_VALUE (MIN_PARTITION_SIZE)) partition_size = PARAM_VALUE (MIN_PARTITION_SIZE); npartitions = 1; partition = new_partition (""); if (cgraph_dump_file) fprintf (cgraph_dump_file, "Total unit size: %i, partition size: %i\n", total_size, partition_size); for (i = 0; i < n_nodes; i++) { if (order[i]->aux) continue; current_order = order[i]->order; if (!flag_toplevel_reorder) while (varpool_pos < n_varpool_nodes && varpool_order[varpool_pos]->order < current_order) { if (!varpool_order[varpool_pos]->aux) add_varpool_node_to_partition (partition, varpool_order[varpool_pos]); varpool_pos++; } add_cgraph_node_to_partition (partition, order[i]); total_size -= inline_summary (order[i])->size; /* Once we added a new node to the partition, we also want to add all referenced variables unless they was already added into some earlier partition. add_cgraph_node_to_partition adds possibly multiple nodes and variables that are needed to satisfy needs of ORDER[i]. We remember last visited cgraph and varpool node from last iteration of outer loop that allows us to process every new addition. At the same time we compute size of the boundary into COST. Every callgraph or IPA reference edge leaving the partition contributes into COST. Every edge inside partition was earlier computed as one leaving it and thus we need to subtract it from COST. */ while (last_visited_cgraph_node < VEC_length (cgraph_node_ptr, partition->cgraph_set->nodes) || last_visited_varpool_node < VEC_length (varpool_node_ptr, partition->varpool_set-> nodes)) { struct ipa_ref_list *refs; int j; struct ipa_ref *ref; bool cgraph_p = false; if (last_visited_cgraph_node < VEC_length (cgraph_node_ptr, partition->cgraph_set->nodes)) { struct cgraph_edge *edge; cgraph_p = true; node = VEC_index (cgraph_node_ptr, partition->cgraph_set->nodes, last_visited_cgraph_node); refs = &node->ref_list; last_visited_cgraph_node++; gcc_assert (node->analyzed); /* Compute boundary cost of callgraph edges. */ for (edge = node->callees; edge; edge = edge->next_callee) if (edge->callee->analyzed) { int edge_cost = edge->frequency; cgraph_node_set_iterator csi; if (!edge_cost) edge_cost = 1; gcc_assert (edge_cost > 0); csi = cgraph_node_set_find (partition->cgraph_set, edge->callee); if (!csi_end_p (csi) && csi.index < last_visited_cgraph_node - 1) cost -= edge_cost, internal+= edge_cost; else cost += edge_cost; } for (edge = node->callers; edge; edge = edge->next_caller) { int edge_cost = edge->frequency; cgraph_node_set_iterator csi; gcc_assert (edge->caller->analyzed); if (!edge_cost) edge_cost = 1; gcc_assert (edge_cost > 0); csi = cgraph_node_set_find (partition->cgraph_set, edge->caller); if (!csi_end_p (csi) && csi.index < last_visited_cgraph_node) cost -= edge_cost; else cost += edge_cost; } } else { refs = &VEC_index (varpool_node_ptr, partition->varpool_set->nodes, last_visited_varpool_node)->ref_list; last_visited_varpool_node++; } /* Compute boundary cost of IPA REF edges and at the same time look into variables referenced from current partition and try to add them. */ for (j = 0; ipa_ref_list_reference_iterate (refs, j, ref); j++) if (ref->refered_type == IPA_REF_VARPOOL) { varpool_node_set_iterator vsi; vnode = ipa_ref_varpool_node (ref); if (!vnode->finalized) continue; if (!vnode->aux && flag_toplevel_reorder && partition_varpool_node_p (vnode)) add_varpool_node_to_partition (partition, vnode); vsi = varpool_node_set_find (partition->varpool_set, vnode); if (!vsi_end_p (vsi) && vsi.index < last_visited_varpool_node - !cgraph_p) cost--, internal++; else cost++; } else { cgraph_node_set_iterator csi; node = ipa_ref_node (ref); if (!node->analyzed) continue; csi = cgraph_node_set_find (partition->cgraph_set, node); if (!csi_end_p (csi) && csi.index < last_visited_cgraph_node - cgraph_p) cost--, internal++; else cost++; } for (j = 0; ipa_ref_list_refering_iterate (refs, j, ref); j++) if (ref->refering_type == IPA_REF_VARPOOL) { varpool_node_set_iterator vsi; vnode = ipa_ref_refering_varpool_node (ref); gcc_assert (vnode->finalized); if (!vnode->aux && flag_toplevel_reorder && partition_varpool_node_p (vnode)) add_varpool_node_to_partition (partition, vnode); vsi = varpool_node_set_find (partition->varpool_set, vnode); if (!vsi_end_p (vsi) && vsi.index < last_visited_varpool_node) cost--; else cost++; } else { cgraph_node_set_iterator csi; node = ipa_ref_refering_node (ref); gcc_assert (node->analyzed); csi = cgraph_node_set_find (partition->cgraph_set, node); if (!csi_end_p (csi) && csi.index < last_visited_cgraph_node) cost--; else cost++; } } /* If the partition is large enough, start looking for smallest boundary cost. */ if (partition->insns < partition_size * 3 / 4 || best_cost == INT_MAX || ((!cost || (best_internal * (HOST_WIDE_INT) cost > (internal * (HOST_WIDE_INT)best_cost))) && partition->insns < partition_size * 5 / 4)) { best_cost = cost; best_internal = internal; best_i = i; best_n_nodes = VEC_length (cgraph_node_ptr, partition->cgraph_set->nodes); best_n_varpool_nodes = VEC_length (varpool_node_ptr, partition->varpool_set->nodes); best_total_size = total_size; } if (cgraph_dump_file) fprintf (cgraph_dump_file, "Step %i: added %s/%i, size %i, cost %i/%i best %i/%i, step %i\n", i, cgraph_node_name (order[i]), order[i]->uid, partition->insns, cost, internal, best_cost, best_internal, best_i); /* Partition is too large, unwind into step when best cost was reached and start new partition. */ if (partition->insns > 2 * partition_size) { if (best_i != i) { if (cgraph_dump_file) fprintf (cgraph_dump_file, "Unwinding %i insertions to step %i\n", i - best_i, best_i); undo_partition (partition, best_n_nodes, best_n_varpool_nodes); } i = best_i; /* When we are finished, avoid creating empty partition. */ while (i < n_nodes - 1 && order[i + 1]->aux) i++; if (i == n_nodes - 1) break; partition = new_partition (""); last_visited_cgraph_node = 0; last_visited_varpool_node = 0; total_size = best_total_size; cost = 0; if (cgraph_dump_file) fprintf (cgraph_dump_file, "New partition\n"); best_n_nodes = 0; best_n_varpool_nodes = 0; best_cost = INT_MAX; /* Since the size of partitions is just approximate, update the size after we finished current one. */ if (npartitions < PARAM_VALUE (PARAM_LTO_PARTITIONS)) partition_size = total_size / (PARAM_VALUE (PARAM_LTO_PARTITIONS) - npartitions); else partition_size = INT_MAX; if (partition_size < PARAM_VALUE (MIN_PARTITION_SIZE)) partition_size = PARAM_VALUE (MIN_PARTITION_SIZE); npartitions ++; } } /* Varables that are not reachable from the code go into last partition. */ if (flag_toplevel_reorder) { for (vnode = varpool_nodes; vnode; vnode = vnode->next) if (partition_varpool_node_p (vnode) && !vnode->aux) add_varpool_node_to_partition (partition, vnode); } else { while (varpool_pos < n_varpool_nodes) { if (!varpool_order[varpool_pos]->aux) add_varpool_node_to_partition (partition, varpool_order[varpool_pos]); varpool_pos++; } free (varpool_order); } free (order); } /* Promote variable VNODE to be static. */ static bool promote_var (struct varpool_node *vnode) { if (TREE_PUBLIC (vnode->decl) || DECL_EXTERNAL (vnode->decl)) return false; gcc_assert (flag_wpa); TREE_PUBLIC (vnode->decl) = 1; DECL_VISIBILITY (vnode->decl) = VISIBILITY_HIDDEN; DECL_VISIBILITY_SPECIFIED (vnode->decl) = true; if (cgraph_dump_file) fprintf (cgraph_dump_file, "Promoting var as hidden: %s\n", varpool_node_name (vnode)); return true; } /* Promote function NODE to be static. */ static bool promote_fn (struct cgraph_node *node) { gcc_assert (flag_wpa); if (TREE_PUBLIC (node->decl) || DECL_EXTERNAL (node->decl)) return false; TREE_PUBLIC (node->decl) = 1; DECL_VISIBILITY (node->decl) = VISIBILITY_HIDDEN; DECL_VISIBILITY_SPECIFIED (node->decl) = true; if (cgraph_dump_file) fprintf (cgraph_dump_file, "Promoting function as hidden: %s/%i\n", cgraph_node_name (node), node->uid); return true; } /* Find out all static decls that need to be promoted to global because of cross file sharing. This function must be run in the WPA mode after all inlinees are added. */ static void lto_promote_cross_file_statics (void) { struct varpool_node *vnode; unsigned i, n_sets; cgraph_node_set set; varpool_node_set vset; cgraph_node_set_iterator csi; varpool_node_set_iterator vsi; VEC(varpool_node_ptr, heap) *promoted_initializers = NULL; struct pointer_set_t *inserted = pointer_set_create (); gcc_assert (flag_wpa); n_sets = VEC_length (ltrans_partition, ltrans_partitions); for (i = 0; i < n_sets; i++) { ltrans_partition part = VEC_index (ltrans_partition, ltrans_partitions, i); set = part->cgraph_set; vset = part->varpool_set; /* If node called or referred to from other partition, it needs to be globalized. */ for (csi = csi_start (set); !csi_end_p (csi); csi_next (&csi)) { struct cgraph_node *node = csi_node (csi); if (node->local.externally_visible) continue; if (node->global.inlined_to) continue; if ((!DECL_EXTERNAL (node->decl) && !DECL_COMDAT (node->decl)) && (referenced_from_other_partition_p (&node->ref_list, set, vset) || reachable_from_other_partition_p (node, set))) promote_fn (node); } for (vsi = vsi_start (vset); !vsi_end_p (vsi); vsi_next (&vsi)) { vnode = vsi_node (vsi); /* Constant pool references use internal labels and thus can not be made global. It is sensible to keep those ltrans local to allow better optimization. */ if (!DECL_IN_CONSTANT_POOL (vnode->decl) && !DECL_COMDAT (vnode->decl) && !vnode->externally_visible && vnode->analyzed && referenced_from_other_partition_p (&vnode->ref_list, set, vset)) promote_var (vnode); } /* We export the initializer of a read-only var into each partition referencing the var. Folding might take declarations from the initializer and use them, so everything referenced from the initializer can be accessed from this partition after folding. This means that we need to promote all variables and functions referenced from all initializers of read-only vars referenced from this partition that are not in this partition. This needs to be done recursively. */ for (vnode = varpool_nodes; vnode; vnode = vnode->next) if (const_value_known_p (vnode->decl) && DECL_INITIAL (vnode->decl) && !varpool_node_in_set_p (vnode, vset) && referenced_from_this_partition_p (&vnode->ref_list, set, vset) && !pointer_set_insert (inserted, vnode)) VEC_safe_push (varpool_node_ptr, heap, promoted_initializers, vnode); while (!VEC_empty (varpool_node_ptr, promoted_initializers)) { int i; struct ipa_ref *ref; vnode = VEC_pop (varpool_node_ptr, promoted_initializers); for (i = 0; ipa_ref_list_reference_iterate (&vnode->ref_list, i, ref); i++) { if (ref->refered_type == IPA_REF_CGRAPH) { struct cgraph_node *n = ipa_ref_node (ref); gcc_assert (!n->global.inlined_to); if (!n->local.externally_visible && !cgraph_node_in_set_p (n, set)) promote_fn (n); } else { struct varpool_node *v = ipa_ref_varpool_node (ref); if (varpool_node_in_set_p (v, vset)) continue; /* Constant pool references use internal labels and thus cannot be made global. It is sensible to keep those ltrans local to allow better optimization. */ if (DECL_IN_CONSTANT_POOL (v->decl)) { if (!pointer_set_insert (inserted, vnode)) VEC_safe_push (varpool_node_ptr, heap, promoted_initializers, v); } else if (!v->externally_visible && v->analyzed) { if (promote_var (v) && DECL_INITIAL (v->decl) && const_value_known_p (v->decl) && !pointer_set_insert (inserted, vnode)) VEC_safe_push (varpool_node_ptr, heap, promoted_initializers, v); } } } } } pointer_set_destroy (inserted); } static lto_file *current_lto_file; /* Helper for qsort; compare partitions and return one with smaller size. We sort from greatest to smallest so parallel build doesn't stale on the longest compilation being executed too late. */ static int cmp_partitions_size (const void *a, const void *b) { const struct ltrans_partition_def *pa = *(struct ltrans_partition_def *const *)a; const struct ltrans_partition_def *pb = *(struct ltrans_partition_def *const *)b; return pb->insns - pa->insns; } /* Helper for qsort; compare partitions and return one with smaller order. */ static int cmp_partitions_order (const void *a, const void *b) { const struct ltrans_partition_def *pa = *(struct ltrans_partition_def *const *)a; const struct ltrans_partition_def *pb = *(struct ltrans_partition_def *const *)b; int ordera = -1, orderb = -1; if (VEC_length (cgraph_node_ptr, pa->cgraph_set->nodes)) ordera = VEC_index (cgraph_node_ptr, pa->cgraph_set->nodes, 0)->order; else if (VEC_length (varpool_node_ptr, pa->varpool_set->nodes)) ordera = VEC_index (varpool_node_ptr, pa->varpool_set->nodes, 0)->order; if (VEC_length (cgraph_node_ptr, pb->cgraph_set->nodes)) orderb = VEC_index (cgraph_node_ptr, pb->cgraph_set->nodes, 0)->order; else if (VEC_length (varpool_node_ptr, pb->varpool_set->nodes)) orderb = VEC_index (varpool_node_ptr, pb->varpool_set->nodes, 0)->order; return orderb - ordera; } /* Write all output files in WPA mode and the file with the list of LTRANS units. */ static void lto_wpa_write_files (void) { unsigned i, n_sets; lto_file *file; cgraph_node_set set; varpool_node_set vset; ltrans_partition part; FILE *ltrans_output_list_stream; char *temp_filename; size_t blen; /* Open the LTRANS output list. */ if (!ltrans_output_list) fatal_error ("no LTRANS output list filename provided"); ltrans_output_list_stream = fopen (ltrans_output_list, "w"); if (ltrans_output_list_stream == NULL) fatal_error ("opening LTRANS output list %s: %m", ltrans_output_list); timevar_push (TV_WHOPR_WPA); FOR_EACH_VEC_ELT (ltrans_partition, ltrans_partitions, i, part) lto_stats.num_output_cgraph_nodes += VEC_length (cgraph_node_ptr, part->cgraph_set->nodes); /* Find out statics that need to be promoted to globals with hidden visibility because they are accessed from multiple partitions. */ lto_promote_cross_file_statics (); timevar_pop (TV_WHOPR_WPA); timevar_push (TV_WHOPR_WPA_IO); /* Generate a prefix for the LTRANS unit files. */ blen = strlen (ltrans_output_list); temp_filename = (char *) xmalloc (blen + sizeof ("2147483648.o")); strcpy (temp_filename, ltrans_output_list); if (blen > sizeof (".out") && strcmp (temp_filename + blen - sizeof (".out") + 1, ".out") == 0) temp_filename[blen - sizeof (".out") + 1] = '\0'; blen = strlen (temp_filename); n_sets = VEC_length (ltrans_partition, ltrans_partitions); /* Sort partitions by size so small ones are compiled last. FIXME: Even when not reordering we may want to output one list for parallel make and other for final link command. */ VEC_qsort (ltrans_partition, ltrans_partitions, flag_toplevel_reorder ? cmp_partitions_size : cmp_partitions_order); for (i = 0; i < n_sets; i++) { size_t len; ltrans_partition part = VEC_index (ltrans_partition, ltrans_partitions, i); set = part->cgraph_set; vset = part->varpool_set; /* Write all the nodes in SET. */ sprintf (temp_filename + blen, "%u.o", i); file = lto_obj_file_open (temp_filename, true); if (!file) fatal_error ("lto_obj_file_open() failed"); if (!quiet_flag) fprintf (stderr, " %s (%s %i insns)", temp_filename, part->name, part->insns); if (cgraph_dump_file) { fprintf (cgraph_dump_file, "Writing partition %s to file %s, %i insns\n", part->name, temp_filename, part->insns); fprintf (cgraph_dump_file, "cgraph nodes:"); dump_cgraph_node_set (cgraph_dump_file, set); fprintf (cgraph_dump_file, "varpool nodes:"); dump_varpool_node_set (cgraph_dump_file, vset); } gcc_checking_assert (cgraph_node_set_nonempty_p (set) || varpool_node_set_nonempty_p (vset) || !i); lto_set_current_out_file (file); ipa_write_optimization_summaries (set, vset); lto_set_current_out_file (NULL); lto_obj_file_close (file); len = strlen (temp_filename); if (fwrite (temp_filename, 1, len, ltrans_output_list_stream) < len || fwrite ("\n", 1, 1, ltrans_output_list_stream) < 1) fatal_error ("writing to LTRANS output list %s: %m", ltrans_output_list); } lto_stats.num_output_files += n_sets; /* Close the LTRANS output list. */ if (fclose (ltrans_output_list_stream)) fatal_error ("closing LTRANS output list %s: %m", ltrans_output_list); free_ltrans_partitions(); timevar_pop (TV_WHOPR_WPA_IO); } /* 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)) \ tt = lto_symtab_prevailing_decl (tt); \ } while (0) /* Ensure that TT isn't a replacable var of function decl. */ #define LTO_NO_PREVAIL(tt) \ gcc_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); LTO_NO_PREVAIL (TREE_TYPE (t)); if (CODE_CONTAINS_STRUCT (code, TS_COMMON)) 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 (t->decl_with_vis.assembler_name); LTO_NO_PREVAIL (DECL_SECTION_NAME (t)); } if (CODE_CONTAINS_STRUCT (code, TS_DECL_NON_COMMON)) { LTO_NO_PREVAIL (DECL_ARGUMENT_FLD (t)); LTO_NO_PREVAIL (DECL_RESULT_FLD (t)); LTO_NO_PREVAIL (DECL_VINDEX (t)); } if (CODE_CONTAINS_STRUCT (code, TS_FUNCTION_DECL)) LTO_SET_PREVAIL (DECL_FUNCTION_PERSONALITY (t)); if (CODE_CONTAINS_STRUCT (code, TS_FIELD_DECL)) { LTO_NO_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_MINVAL (t)); LTO_SET_PREVAIL (TYPE_MAXVAL (t)); LTO_SET_PREVAIL (t->type_non_common.binfo); 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; LTO_NO_PREVAIL (t->exp.block); for (i = TREE_OPERAND_LENGTH (t) - 1; i >= 0; --i) LTO_SET_PREVAIL (TREE_OPERAND (t, i)); } else { switch (code) { case TREE_LIST: LTO_SET_PREVAIL (TREE_VALUE (t)); LTO_SET_PREVAIL (TREE_PURPOSE (t)); break; default: gcc_unreachable (); } } } #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; struct lto_tree_ref_table *table; /* 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++) { table = &state->streams[si]; for (i = 0; i < table->size; i++) { tree *tp = table->trees + i; if (VAR_OR_FUNCTION_DECL_P (*tp)) *tp = lto_symtab_prevailing_decl (*tp); } } } /* A callback of htab_traverse. Just extracts a state from SLOT and calls lto_fixup_state. */ static int lto_fixup_state_aux (void **slot, void *aux ATTRIBUTE_UNUSED) { struct lto_in_decl_state *state = (struct lto_in_decl_state *) *slot; lto_fixup_state (state); return 1; } /* 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; htab_iterator hi; tree t; FOR_EACH_HTAB_ELEMENT (tree_with_vars, t, tree, hi) 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); htab_traverse (file->function_decl_states, lto_fixup_state_aux, NULL); } } 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_alloc_cleared_vec_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. */ static void read_cgraph_and_symbols (unsigned nfiles, const char **fnames) { unsigned int i, last_file_ix; FILE *resolution; struct cgraph_node *node; int count = 0; struct lto_file_decl_data **decl_data; init_cgraph (); timevar_push (TV_IPA_LTO_DECL_IN); real_file_decl_data = decl_data = ggc_alloc_cleared_vec_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 ("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); } tree_with_vars = htab_create_ggc (101, htab_hash_pointer, htab_eq_pointer, NULL); 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); current_lto_file = NULL; break; } decl_data[last_file_ix++] = file_data; lto_obj_file_close (current_lto_file); current_lto_file = NULL; ggc_collect (); } lto_flatten_files (decl_data, count, last_file_ix); lto_stats.num_input_files = count; ggc_free(decl_data); real_file_decl_data = NULL; if (resolution_file_name) fclose (resolution); /* 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 callgraph\n"); timevar_push (TV_IPA_LTO_CGRAPH_IO); /* Read the callgraph. */ input_cgraph (); timevar_pop (TV_IPA_LTO_CGRAPH_IO); if (!quiet_flag) fprintf (stderr, "Merging declarations\n"); timevar_push (TV_IPA_LTO_DECL_MERGE); /* Merge global decls. */ 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 ("errors during merging of translation units"); /* Fixup all decls and types and free the type hash tables. */ lto_fixup_decls (all_file_decl_data); htab_delete (tree_with_vars); tree_with_vars = NULL; free_gimple_type_tables (); ggc_collect (); timevar_pop (TV_IPA_LTO_DECL_MERGE); /* Each pass will set the appropriate timer. */ if (!quiet_flag) fprintf (stderr, "Reading summaries\n"); /* Read the IPA summary data. */ if (flag_ltrans) ipa_read_optimization_summaries (); else ipa_read_summaries (); /* Finally merge the cgraph according to the decl merging decisions. */ timevar_push (TV_IPA_LTO_CGRAPH_MERGE); if (cgraph_dump_file) { fprintf (cgraph_dump_file, "Before merging:\n"); dump_cgraph (cgraph_dump_file); dump_varpool (cgraph_dump_file); } lto_symtab_merge_cgraph_nodes (); ggc_collect (); if (flag_ltrans) for (node = cgraph_nodes; node; node = node->next) { /* FIXME: ipa_transforms_to_apply holds list of passes that have optimization summaries computed and needs to apply changes. At the moment WHOPR only supports inlining, so we can push it here by hand. In future we need to stream this field into ltrans compilation. */ if (node->analyzed) VEC_safe_push (ipa_opt_pass, heap, node->ipa_transforms_to_apply, (ipa_opt_pass)&pass_ipa_inline); } lto_symtab_free (); timevar_pop (TV_IPA_LTO_CGRAPH_MERGE); timevar_push (TV_IPA_LTO_DECL_INIT_IO); /* FIXME lto. This loop needs to be changed to use the pass manager to call the ipa passes directly. */ if (!seen_error ()) for (i = 0; i < last_file_ix; i++) { struct lto_file_decl_data *file_data = all_file_decl_data [i]; lto_materialize_constructors_and_inits (file_data); } /* Indicate that the cgraph is built and ready. */ cgraph_function_flags_ready = true; timevar_pop (TV_IPA_LTO_DECL_INIT_IO); ggc_free (all_file_decl_data); all_file_decl_data = NULL; } /* Materialize all the bodies for all the nodes in the callgraph. */ static void materialize_cgraph (void) { tree decl; struct cgraph_node *node; unsigned i; timevar_id_t lto_timer; if (!quiet_flag) fprintf (stderr, flag_wpa ? "Materializing decls:" : "Reading function bodies:"); /* Now that we have input the cgraph, we need to clear all of the aux nodes and read the functions if we are not running in WPA mode. */ timevar_push (TV_IPA_LTO_GIMPLE_IN); for (node = cgraph_nodes; node; node = node->next) { if (node->local.lto_file_data) { lto_materialize_function (node); lto_stats.num_input_cgraph_nodes++; } } timevar_pop (TV_IPA_LTO_GIMPLE_IN); /* Start the appropriate timer depending on the mode that we are operating in. */ lto_timer = (flag_wpa) ? TV_WHOPR_WPA : (flag_ltrans) ? TV_WHOPR_LTRANS : TV_LTO; timevar_push (lto_timer); current_function_decl = NULL; set_cfun (NULL); /* Inform the middle end about the global variables we have seen. */ FOR_EACH_VEC_ELT (tree, lto_global_var_decls, i, decl) rest_of_decl_compilation (decl, 1, 0); if (!quiet_flag) fprintf (stderr, "\n"); timevar_pop (lto_timer); } /* Perform whole program analysis (WPA) on the callgraph and write out the optimization plan. */ static void do_whole_program_analysis (void) { /* Note that since we are in WPA mode, materialize_cgraph will not actually read in all the function bodies. It only materializes the decls and cgraph nodes so that analysis can be performed. */ materialize_cgraph (); /* Reading in the cgraph uses different timers, start timing WPA now. */ timevar_push (TV_WHOPR_WPA); if (pre_ipa_mem_report) { fprintf (stderr, "Memory consumption before IPA\n"); dump_memory_report (false); } cgraph_function_flags_ready = true; if (cgraph_dump_file) { dump_cgraph (cgraph_dump_file); dump_varpool (cgraph_dump_file); } bitmap_obstack_initialize (NULL); cgraph_state = CGRAPH_STATE_IPA_SSA; execute_ipa_pass_list (all_regular_ipa_passes); if (cgraph_dump_file) { fprintf (cgraph_dump_file, "Optimized "); dump_cgraph (cgraph_dump_file); dump_varpool (cgraph_dump_file); } verify_cgraph (); bitmap_obstack_release (NULL); /* We are about to launch the final LTRANS phase, stop the WPA timer. */ timevar_pop (TV_WHOPR_WPA); if (flag_lto_partition_1to1) lto_1_to_1_map (); else lto_balanced_map (); if (!quiet_flag) { fprintf (stderr, "\nStreaming out"); fflush (stderr); } lto_wpa_write_files (); ggc_collect (); if (!quiet_flag) fprintf (stderr, "\n"); if (post_ipa_mem_report) { fprintf (stderr, "Memory consumption after IPA\n"); dump_memory_report (false); } /* Show the LTO report before launching LTRANS. */ if (flag_lto_report) print_lto_report (); } static 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 ("lto1-lto"); if (flag_wpa) setproctitle ("lto1-wpa"); if (flag_ltrans) setproctitle ("lto1-ltrans"); } /* Initialize the LTO front end. */ static void lto_init (void) { lto_process_name (); lto_streamer_hooks_init (); lto_reader_init (); lto_set_in_hooks (NULL, get_section_data, free_section_data); memset (<o_stats, 0, sizeof (lto_stats)); bitmap_obstack_initialize (NULL); gimple_register_cfg_hooks (); } /* Main entry point for the GIMPLE front end. This front end has three main personalities: - LTO (-flto). All the object files on the command line are loaded in memory and processed as a single translation unit. This is the traditional link-time optimization behavior. - WPA (-fwpa). Only the callgraph and summary information for files in the command file are loaded. A single callgraph (without function bodies) is instantiated for the whole set of files. IPA passes are only allowed to analyze the call graph and make transformation decisions. The callgraph is partitioned, each partition is written to a new object file together with the transformation decisions. - LTRANS (-fltrans). Similar to -flto but it prevents the IPA summary files from running again. Since WPA computed summary information and decided what transformations to apply, LTRANS simply applies them. */ void lto_main (void) { /* Initialize the LTO front end. */ lto_init (); /* Read all the symbols and call graph from all the files in the command line. */ read_cgraph_and_symbols (num_in_fnames, in_fnames); if (!seen_error ()) { /* If WPA is enabled analyze the whole call graph and create an optimization plan. Otherwise, read in all the function bodies and continue with optimization. */ if (flag_wpa) do_whole_program_analysis (); else { materialize_cgraph (); /* Let the middle end know that we have read and merged all of the input files. */ cgraph_optimize (); /* FIXME lto, if the processes spawned by WPA fail, we miss the chance to print WPA's report, so WPA will call print_lto_report before launching LTRANS. If LTRANS was launched directly by the driver we would not need to do this. */ if (flag_lto_report) print_lto_report (); } } } #include "gt-lto-lto.h"