1 /* Top-level LTO routines.
2 Copyright 2009, 2010, 2011 Free Software Foundation, Inc.
3 Contributed by CodeSourcery, Inc.
4
5 This file is part of GCC.
6
7 GCC is free software; you can redistribute it and/or modify it under
8 the terms of the GNU General Public License as published by the Free
9 Software Foundation; either version 3, or (at your option) any later
10 version.
11
12 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
13 WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
15 for more details.
16
17 You should have received a copy of the GNU General Public License
18 along with GCC; see the file COPYING3. If not see
19 <http://www.gnu.org/licenses/>. */
20
21 #include "config.h"
22 #include "system.h"
23 #include "coretypes.h"
24 #include "opts.h"
25 #include "toplev.h"
26 #include "tree.h"
27 #include "tree-flow.h"
28 #include "output.h"
29 #include "diagnostic-core.h"
30 #include "tm.h"
31 #include "cgraph.h"
32 #include "ggc.h"
33 #include "tree-ssa-operands.h"
34 #include "tree-pass.h"
35 #include "langhooks.h"
36 #include "vec.h"
37 #include "bitmap.h"
38 #include "pointer-set.h"
39 #include "ipa-prop.h"
40 #include "common.h"
41 #include "debug.h"
42 #include "timevar.h"
43 #include "gimple.h"
44 #include "lto.h"
45 #include "lto-tree.h"
46 #include "lto-streamer.h"
47 #include "tree-streamer.h"
48 #include "splay-tree.h"
49 #include "params.h"
50 #include "ipa-inline.h"
51 #include "ipa-utils.h"
52
53 static GTY(()) tree first_personality_decl;
54
55 /* Returns a hash code for P. */
56
57 static hashval_t
hash_name(const void * p)58 hash_name (const void *p)
59 {
60 const struct lto_section_slot *ds = (const struct lto_section_slot *) p;
61 return (hashval_t) htab_hash_string (ds->name);
62 }
63
64
65 /* Returns nonzero if P1 and P2 are equal. */
66
67 static int
eq_name(const void * p1,const void * p2)68 eq_name (const void *p1, const void *p2)
69 {
70 const struct lto_section_slot *s1 =
71 (const struct lto_section_slot *) p1;
72 const struct lto_section_slot *s2 =
73 (const struct lto_section_slot *) p2;
74
75 return strcmp (s1->name, s2->name) == 0;
76 }
77
78 /* Free lto_section_slot */
79
80 static void
free_with_string(void * arg)81 free_with_string (void *arg)
82 {
83 struct lto_section_slot *s = (struct lto_section_slot *)arg;
84
85 free (CONST_CAST (char *, s->name));
86 free (arg);
87 }
88
89 /* Create section hash table */
90
91 htab_t
lto_obj_create_section_hash_table(void)92 lto_obj_create_section_hash_table (void)
93 {
94 return htab_create (37, hash_name, eq_name, free_with_string);
95 }
96
97 /* Delete an allocated integer KEY in the splay tree. */
98
99 static void
lto_splay_tree_delete_id(splay_tree_key key)100 lto_splay_tree_delete_id (splay_tree_key key)
101 {
102 free ((void *) key);
103 }
104
105 /* Compare splay tree node ids A and B. */
106
107 static int
lto_splay_tree_compare_ids(splay_tree_key a,splay_tree_key b)108 lto_splay_tree_compare_ids (splay_tree_key a, splay_tree_key b)
109 {
110 unsigned HOST_WIDE_INT ai;
111 unsigned HOST_WIDE_INT bi;
112
113 ai = *(unsigned HOST_WIDE_INT *) a;
114 bi = *(unsigned HOST_WIDE_INT *) b;
115
116 if (ai < bi)
117 return -1;
118 else if (ai > bi)
119 return 1;
120 return 0;
121 }
122
123 /* Look up splay tree node by ID in splay tree T. */
124
125 static splay_tree_node
lto_splay_tree_lookup(splay_tree t,unsigned HOST_WIDE_INT id)126 lto_splay_tree_lookup (splay_tree t, unsigned HOST_WIDE_INT id)
127 {
128 return splay_tree_lookup (t, (splay_tree_key) &id);
129 }
130
131 /* Check if KEY has ID. */
132
133 static bool
lto_splay_tree_id_equal_p(splay_tree_key key,unsigned HOST_WIDE_INT id)134 lto_splay_tree_id_equal_p (splay_tree_key key, unsigned HOST_WIDE_INT id)
135 {
136 return *(unsigned HOST_WIDE_INT *) key == id;
137 }
138
139 /* Insert a splay tree node into tree T with ID as key and FILE_DATA as value.
140 The ID is allocated separately because we need HOST_WIDE_INTs which may
141 be wider than a splay_tree_key. */
142
143 static void
lto_splay_tree_insert(splay_tree t,unsigned HOST_WIDE_INT id,struct lto_file_decl_data * file_data)144 lto_splay_tree_insert (splay_tree t, unsigned HOST_WIDE_INT id,
145 struct lto_file_decl_data *file_data)
146 {
147 unsigned HOST_WIDE_INT *idp = XCNEW (unsigned HOST_WIDE_INT);
148 *idp = id;
149 splay_tree_insert (t, (splay_tree_key) idp, (splay_tree_value) file_data);
150 }
151
152 /* Create a splay tree. */
153
154 static splay_tree
lto_splay_tree_new(void)155 lto_splay_tree_new (void)
156 {
157 return splay_tree_new (lto_splay_tree_compare_ids,
158 lto_splay_tree_delete_id,
159 NULL);
160 }
161
162 /* Read the constructors and inits. */
163
164 static void
lto_materialize_constructors_and_inits(struct lto_file_decl_data * file_data)165 lto_materialize_constructors_and_inits (struct lto_file_decl_data * file_data)
166 {
167 size_t len;
168 const char *data = lto_get_section_data (file_data,
169 LTO_section_static_initializer,
170 NULL, &len);
171 lto_input_constructors_and_inits (file_data, data);
172 lto_free_section_data (file_data, LTO_section_static_initializer, NULL,
173 data, len);
174 }
175
176 /* Return true when NODE has a clone that is analyzed (i.e. we need
177 to load its body even if the node itself is not needed). */
178
179 static bool
has_analyzed_clone_p(struct cgraph_node * node)180 has_analyzed_clone_p (struct cgraph_node *node)
181 {
182 struct cgraph_node *orig = node;
183 node = node->clones;
184 if (node)
185 while (node != orig)
186 {
187 if (node->analyzed)
188 return true;
189 if (node->clones)
190 node = node->clones;
191 else if (node->next_sibling_clone)
192 node = node->next_sibling_clone;
193 else
194 {
195 while (node != orig && !node->next_sibling_clone)
196 node = node->clone_of;
197 if (node != orig)
198 node = node->next_sibling_clone;
199 }
200 }
201 return false;
202 }
203
204 /* Read the function body for the function associated with NODE. */
205
206 static void
lto_materialize_function(struct cgraph_node * node)207 lto_materialize_function (struct cgraph_node *node)
208 {
209 tree decl;
210 struct lto_file_decl_data *file_data;
211 const char *data, *name;
212 size_t len;
213
214 decl = node->decl;
215 /* Read in functions with body (analyzed nodes)
216 and also functions that are needed to produce virtual clones. */
217 if (cgraph_function_with_gimple_body_p (node) || has_analyzed_clone_p (node))
218 {
219 /* Clones and thunks don't need to be read. */
220 if (node->clone_of)
221 return;
222
223 /* Load the function body only if not operating in WPA mode. In
224 WPA mode, the body of the function is not needed. */
225 if (!flag_wpa)
226 {
227 file_data = node->local.lto_file_data;
228 name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
229
230 /* We may have renamed the declaration, e.g., a static function. */
231 name = lto_get_decl_name_mapping (file_data, name);
232
233 data = lto_get_section_data (file_data, LTO_section_function_body,
234 name, &len);
235 if (!data)
236 fatal_error ("%s: section %s is missing",
237 file_data->file_name,
238 name);
239
240 gcc_assert (DECL_STRUCT_FUNCTION (decl) == NULL);
241
242 allocate_struct_function (decl, false);
243 announce_function (decl);
244 lto_input_function_body (file_data, decl, data);
245 if (DECL_FUNCTION_PERSONALITY (decl) && !first_personality_decl)
246 first_personality_decl = DECL_FUNCTION_PERSONALITY (decl);
247 lto_stats.num_function_bodies++;
248 lto_free_section_data (file_data, LTO_section_function_body, name,
249 data, len);
250 ggc_collect ();
251 }
252 }
253
254 /* Let the middle end know about the function. */
255 rest_of_decl_compilation (decl, 1, 0);
256 }
257
258
259 /* Decode the content of memory pointed to by DATA in the in decl
260 state object STATE. DATA_IN points to a data_in structure for
261 decoding. Return the address after the decoded object in the
262 input. */
263
264 static const uint32_t *
lto_read_in_decl_state(struct data_in * data_in,const uint32_t * data,struct lto_in_decl_state * state)265 lto_read_in_decl_state (struct data_in *data_in, const uint32_t *data,
266 struct lto_in_decl_state *state)
267 {
268 uint32_t ix;
269 tree decl;
270 uint32_t i, j;
271
272 ix = *data++;
273 decl = streamer_tree_cache_get (data_in->reader_cache, ix);
274 if (TREE_CODE (decl) != FUNCTION_DECL)
275 {
276 gcc_assert (decl == void_type_node);
277 decl = NULL_TREE;
278 }
279 state->fn_decl = decl;
280
281 for (i = 0; i < LTO_N_DECL_STREAMS; i++)
282 {
283 uint32_t size = *data++;
284 tree *decls = ggc_alloc_vec_tree (size);
285
286 for (j = 0; j < size; j++)
287 decls[j] = streamer_tree_cache_get (data_in->reader_cache, data[j]);
288
289 state->streams[i].size = size;
290 state->streams[i].trees = decls;
291 data += size;
292 }
293
294 return data;
295 }
296
297 /* A hashtable of trees that potentially refer to variables or functions
298 that must be replaced with their prevailing variant. */
299 static GTY((if_marked ("ggc_marked_p"), param_is (union tree_node))) htab_t
300 tree_with_vars;
301
302 /* Remember that T is a tree that (potentially) refers to a variable
303 or function decl that may be replaced with its prevailing variant. */
304 static void
remember_with_vars(tree t)305 remember_with_vars (tree t)
306 {
307 *(tree *) htab_find_slot (tree_with_vars, t, INSERT) = t;
308 }
309
310 #define GIMPLE_REGISTER_TYPE(tt) \
311 (TREE_VISITED (tt) ? gimple_register_type (tt) : tt)
312
313 #define LTO_FIXUP_TREE(tt) \
314 do \
315 { \
316 if (tt) \
317 { \
318 if (TYPE_P (tt)) \
319 (tt) = GIMPLE_REGISTER_TYPE (tt); \
320 if (VAR_OR_FUNCTION_DECL_P (tt) && TREE_PUBLIC (tt)) \
321 remember_with_vars (t); \
322 } \
323 } while (0)
324
325 static void lto_fixup_types (tree);
326
327 /* Fix up fields of a tree_typed T. */
328
329 static void
lto_ft_typed(tree t)330 lto_ft_typed (tree t)
331 {
332 LTO_FIXUP_TREE (TREE_TYPE (t));
333 }
334
335 /* Fix up fields of a tree_common T. */
336
337 static void
lto_ft_common(tree t)338 lto_ft_common (tree t)
339 {
340 lto_ft_typed (t);
341 LTO_FIXUP_TREE (TREE_CHAIN (t));
342 }
343
344 /* Fix up fields of a decl_minimal T. */
345
346 static void
lto_ft_decl_minimal(tree t)347 lto_ft_decl_minimal (tree t)
348 {
349 lto_ft_common (t);
350 LTO_FIXUP_TREE (DECL_NAME (t));
351 LTO_FIXUP_TREE (DECL_CONTEXT (t));
352 }
353
354 /* Fix up fields of a decl_common T. */
355
356 static void
lto_ft_decl_common(tree t)357 lto_ft_decl_common (tree t)
358 {
359 lto_ft_decl_minimal (t);
360 LTO_FIXUP_TREE (DECL_SIZE (t));
361 LTO_FIXUP_TREE (DECL_SIZE_UNIT (t));
362 LTO_FIXUP_TREE (DECL_INITIAL (t));
363 LTO_FIXUP_TREE (DECL_ATTRIBUTES (t));
364 LTO_FIXUP_TREE (DECL_ABSTRACT_ORIGIN (t));
365 }
366
367 /* Fix up fields of a decl_with_vis T. */
368
369 static void
lto_ft_decl_with_vis(tree t)370 lto_ft_decl_with_vis (tree t)
371 {
372 lto_ft_decl_common (t);
373
374 /* Accessor macro has side-effects, use field-name here. */
375 LTO_FIXUP_TREE (t->decl_with_vis.assembler_name);
376 LTO_FIXUP_TREE (DECL_SECTION_NAME (t));
377 }
378
379 /* Fix up fields of a decl_non_common T. */
380
381 static void
lto_ft_decl_non_common(tree t)382 lto_ft_decl_non_common (tree t)
383 {
384 lto_ft_decl_with_vis (t);
385 LTO_FIXUP_TREE (DECL_ARGUMENT_FLD (t));
386 LTO_FIXUP_TREE (DECL_RESULT_FLD (t));
387 LTO_FIXUP_TREE (DECL_VINDEX (t));
388 /* The C frontends may create exact duplicates for DECL_ORIGINAL_TYPE
389 like for 'typedef enum foo foo'. We have no way of avoiding to
390 merge them and dwarf2out.c cannot deal with this,
391 so fix this up by clearing DECL_ORIGINAL_TYPE in this case. */
392 if (TREE_CODE (t) == TYPE_DECL
393 && DECL_ORIGINAL_TYPE (t) == TREE_TYPE (t))
394 DECL_ORIGINAL_TYPE (t) = NULL_TREE;
395 }
396
397 /* Fix up fields of a decl_non_common T. */
398
399 static void
lto_ft_function(tree t)400 lto_ft_function (tree t)
401 {
402 lto_ft_decl_non_common (t);
403 LTO_FIXUP_TREE (DECL_FUNCTION_PERSONALITY (t));
404 }
405
406 /* Fix up fields of a field_decl T. */
407
408 static void
lto_ft_field_decl(tree t)409 lto_ft_field_decl (tree t)
410 {
411 lto_ft_decl_common (t);
412 LTO_FIXUP_TREE (DECL_FIELD_OFFSET (t));
413 LTO_FIXUP_TREE (DECL_BIT_FIELD_TYPE (t));
414 LTO_FIXUP_TREE (DECL_QUALIFIER (t));
415 LTO_FIXUP_TREE (DECL_FIELD_BIT_OFFSET (t));
416 LTO_FIXUP_TREE (DECL_FCONTEXT (t));
417 }
418
419 /* Fix up fields of a type T. */
420
421 static void
lto_ft_type(tree t)422 lto_ft_type (tree t)
423 {
424 lto_ft_common (t);
425 LTO_FIXUP_TREE (TYPE_CACHED_VALUES (t));
426 LTO_FIXUP_TREE (TYPE_SIZE (t));
427 LTO_FIXUP_TREE (TYPE_SIZE_UNIT (t));
428 LTO_FIXUP_TREE (TYPE_ATTRIBUTES (t));
429 LTO_FIXUP_TREE (TYPE_NAME (t));
430
431 /* Accessors are for derived node types only. */
432 if (!POINTER_TYPE_P (t))
433 LTO_FIXUP_TREE (TYPE_MINVAL (t));
434 LTO_FIXUP_TREE (TYPE_MAXVAL (t));
435
436 /* Accessor is for derived node types only. */
437 LTO_FIXUP_TREE (t->type_non_common.binfo);
438
439 LTO_FIXUP_TREE (TYPE_CONTEXT (t));
440 }
441
442 /* Fix up fields of a BINFO T. */
443
444 static void
lto_ft_binfo(tree t)445 lto_ft_binfo (tree t)
446 {
447 unsigned HOST_WIDE_INT i, n;
448 tree base, saved_base;
449
450 lto_ft_common (t);
451 LTO_FIXUP_TREE (BINFO_VTABLE (t));
452 LTO_FIXUP_TREE (BINFO_OFFSET (t));
453 LTO_FIXUP_TREE (BINFO_VIRTUALS (t));
454 LTO_FIXUP_TREE (BINFO_VPTR_FIELD (t));
455 n = VEC_length (tree, BINFO_BASE_ACCESSES (t));
456 for (i = 0; i < n; i++)
457 {
458 saved_base = base = BINFO_BASE_ACCESS (t, i);
459 LTO_FIXUP_TREE (base);
460 if (base != saved_base)
461 VEC_replace (tree, BINFO_BASE_ACCESSES (t), i, base);
462 }
463 LTO_FIXUP_TREE (BINFO_INHERITANCE_CHAIN (t));
464 LTO_FIXUP_TREE (BINFO_SUBVTT_INDEX (t));
465 LTO_FIXUP_TREE (BINFO_VPTR_INDEX (t));
466 n = BINFO_N_BASE_BINFOS (t);
467 for (i = 0; i < n; i++)
468 {
469 saved_base = base = BINFO_BASE_BINFO (t, i);
470 LTO_FIXUP_TREE (base);
471 if (base != saved_base)
472 VEC_replace (tree, BINFO_BASE_BINFOS (t), i, base);
473 }
474 }
475
476 /* Fix up fields of a CONSTRUCTOR T. */
477
478 static void
lto_ft_constructor(tree t)479 lto_ft_constructor (tree t)
480 {
481 unsigned HOST_WIDE_INT idx;
482 constructor_elt *ce;
483
484 lto_ft_typed (t);
485
486 for (idx = 0;
487 VEC_iterate(constructor_elt, CONSTRUCTOR_ELTS (t), idx, ce);
488 idx++)
489 {
490 LTO_FIXUP_TREE (ce->index);
491 LTO_FIXUP_TREE (ce->value);
492 }
493 }
494
495 /* Fix up fields of an expression tree T. */
496
497 static void
lto_ft_expr(tree t)498 lto_ft_expr (tree t)
499 {
500 int i;
501 lto_ft_typed (t);
502 for (i = TREE_OPERAND_LENGTH (t) - 1; i >= 0; --i)
503 LTO_FIXUP_TREE (TREE_OPERAND (t, i));
504 }
505
506 /* Given a tree T fixup fields of T by replacing types with their merged
507 variant and other entities by an equal entity from an earlier compilation
508 unit, or an entity being canonical in a different way. This includes
509 for instance integer or string constants. */
510
511 static void
lto_fixup_types(tree t)512 lto_fixup_types (tree t)
513 {
514 switch (TREE_CODE (t))
515 {
516 case IDENTIFIER_NODE:
517 break;
518
519 case TREE_LIST:
520 LTO_FIXUP_TREE (TREE_VALUE (t));
521 LTO_FIXUP_TREE (TREE_PURPOSE (t));
522 LTO_FIXUP_TREE (TREE_CHAIN (t));
523 break;
524
525 case FIELD_DECL:
526 lto_ft_field_decl (t);
527 break;
528
529 case LABEL_DECL:
530 case CONST_DECL:
531 case PARM_DECL:
532 case RESULT_DECL:
533 case IMPORTED_DECL:
534 lto_ft_decl_common (t);
535 break;
536
537 case VAR_DECL:
538 lto_ft_decl_with_vis (t);
539 break;
540
541 case TYPE_DECL:
542 lto_ft_decl_non_common (t);
543 break;
544
545 case FUNCTION_DECL:
546 lto_ft_function (t);
547 break;
548
549 case TREE_BINFO:
550 lto_ft_binfo (t);
551 break;
552
553 case PLACEHOLDER_EXPR:
554 lto_ft_common (t);
555 break;
556
557 case BLOCK:
558 case TRANSLATION_UNIT_DECL:
559 case OPTIMIZATION_NODE:
560 case TARGET_OPTION_NODE:
561 break;
562
563 default:
564 if (TYPE_P (t))
565 lto_ft_type (t);
566 else if (TREE_CODE (t) == CONSTRUCTOR)
567 lto_ft_constructor (t);
568 else if (CONSTANT_CLASS_P (t))
569 LTO_FIXUP_TREE (TREE_TYPE (t));
570 else if (EXPR_P (t))
571 {
572 lto_ft_expr (t);
573 }
574 else
575 {
576 remember_with_vars (t);
577 }
578 }
579 }
580
581
582 /* Return the resolution for the decl with index INDEX from DATA_IN. */
583
584 static enum ld_plugin_symbol_resolution
get_resolution(struct data_in * data_in,unsigned index)585 get_resolution (struct data_in *data_in, unsigned index)
586 {
587 if (data_in->globals_resolution)
588 {
589 ld_plugin_symbol_resolution_t ret;
590 /* We can have references to not emitted functions in
591 DECL_FUNCTION_PERSONALITY at least. So we can and have
592 to indeed return LDPR_UNKNOWN in some cases. */
593 if (VEC_length (ld_plugin_symbol_resolution_t,
594 data_in->globals_resolution) <= index)
595 return LDPR_UNKNOWN;
596 ret = VEC_index (ld_plugin_symbol_resolution_t,
597 data_in->globals_resolution,
598 index);
599 return ret;
600 }
601 else
602 /* Delay resolution finding until decl merging. */
603 return LDPR_UNKNOWN;
604 }
605
606
607 /* Register DECL with the global symbol table and change its
608 name if necessary to avoid name clashes for static globals across
609 different files. */
610
611 static void
lto_register_var_decl_in_symtab(struct data_in * data_in,tree decl)612 lto_register_var_decl_in_symtab (struct data_in *data_in, tree decl)
613 {
614 tree context;
615
616 /* Variable has file scope, not local. Need to ensure static variables
617 between different files don't clash unexpectedly. */
618 if (!TREE_PUBLIC (decl)
619 && !((context = decl_function_context (decl))
620 && auto_var_in_fn_p (decl, context)))
621 {
622 /* ??? We normally pre-mangle names before we serialize them
623 out. Here, in lto1, we do not know the language, and
624 thus cannot do the mangling again. Instead, we just
625 append a suffix to the mangled name. The resulting name,
626 however, is not a properly-formed mangled name, and will
627 confuse any attempt to unmangle it. */
628 const char *name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
629 char *label;
630
631 ASM_FORMAT_PRIVATE_NAME (label, name, DECL_UID (decl));
632 SET_DECL_ASSEMBLER_NAME (decl, get_identifier (label));
633 rest_of_decl_compilation (decl, 1, 0);
634 VEC_safe_push (tree, gc, lto_global_var_decls, decl);
635 }
636
637 /* If this variable has already been declared, queue the
638 declaration for merging. */
639 if (TREE_PUBLIC (decl))
640 {
641 unsigned ix;
642 if (!streamer_tree_cache_lookup (data_in->reader_cache, decl, &ix))
643 gcc_unreachable ();
644 lto_symtab_register_decl (decl, get_resolution (data_in, ix),
645 data_in->file_data);
646 }
647 }
648
649
650 /* Register DECL with the global symbol table and change its
651 name if necessary to avoid name clashes for static globals across
652 different files. DATA_IN contains descriptors and tables for the
653 file being read. */
654
655 static void
lto_register_function_decl_in_symtab(struct data_in * data_in,tree decl)656 lto_register_function_decl_in_symtab (struct data_in *data_in, tree decl)
657 {
658 /* Need to ensure static entities between different files
659 don't clash unexpectedly. */
660 if (!TREE_PUBLIC (decl))
661 {
662 /* We must not use the DECL_ASSEMBLER_NAME macro here, as it
663 may set the assembler name where it was previously empty. */
664 tree old_assembler_name = decl->decl_with_vis.assembler_name;
665
666 /* FIXME lto: We normally pre-mangle names before we serialize
667 them out. Here, in lto1, we do not know the language, and
668 thus cannot do the mangling again. Instead, we just append a
669 suffix to the mangled name. The resulting name, however, is
670 not a properly-formed mangled name, and will confuse any
671 attempt to unmangle it. */
672 const char *name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
673 char *label;
674
675 ASM_FORMAT_PRIVATE_NAME (label, name, DECL_UID (decl));
676 SET_DECL_ASSEMBLER_NAME (decl, get_identifier (label));
677
678 /* We may arrive here with the old assembler name not set
679 if the function body is not needed, e.g., it has been
680 inlined away and does not appear in the cgraph. */
681 if (old_assembler_name)
682 {
683 tree new_assembler_name = DECL_ASSEMBLER_NAME (decl);
684
685 /* Make the original assembler name available for later use.
686 We may have used it to indicate the section within its
687 object file where the function body may be found.
688 FIXME lto: Find a better way to maintain the function decl
689 to body section mapping so we don't need this hack. */
690 lto_record_renamed_decl (data_in->file_data,
691 IDENTIFIER_POINTER (old_assembler_name),
692 IDENTIFIER_POINTER (new_assembler_name));
693 }
694 }
695
696 /* If this variable has already been declared, queue the
697 declaration for merging. */
698 if (TREE_PUBLIC (decl) && !DECL_ABSTRACT (decl))
699 {
700 unsigned ix;
701 if (!streamer_tree_cache_lookup (data_in->reader_cache, decl, &ix))
702 gcc_unreachable ();
703 lto_symtab_register_decl (decl, get_resolution (data_in, ix),
704 data_in->file_data);
705 }
706 }
707
708
709 /* Given a streamer cache structure DATA_IN (holding a sequence of trees
710 for one compilation unit) go over all trees starting at index FROM until the
711 end of the sequence and replace fields of those trees, and the trees
712 themself with their canonical variants as per gimple_register_type. */
713
714 static void
uniquify_nodes(struct data_in * data_in,unsigned from)715 uniquify_nodes (struct data_in *data_in, unsigned from)
716 {
717 struct streamer_tree_cache_d *cache = data_in->reader_cache;
718 unsigned len = VEC_length (tree, cache->nodes);
719 unsigned i;
720
721 /* Go backwards because children streamed for the first time come
722 as part of their parents, and hence are created after them. */
723
724 /* First register all the types in the cache. This makes sure to
725 have the original structure in the type cycles when registering
726 them and computing hashes. */
727 for (i = len; i-- > from;)
728 {
729 tree t = VEC_index (tree, cache->nodes, i);
730 if (t && TYPE_P (t))
731 {
732 tree newt = gimple_register_type (t);
733 /* Mark non-prevailing types so we fix them up. No need
734 to reset that flag afterwards - nothing that refers
735 to those types is left and they are collected. */
736 if (newt != t)
737 TREE_VISITED (t) = 1;
738 }
739 }
740
741 /* Second fixup all trees in the new cache entries. */
742 for (i = len; i-- > from;)
743 {
744 tree t = VEC_index (tree, cache->nodes, i);
745 tree oldt = t;
746 if (!t)
747 continue;
748
749 /* First fixup the fields of T. */
750 lto_fixup_types (t);
751
752 if (!TYPE_P (t))
753 continue;
754
755 /* Now try to find a canonical variant of T itself. */
756 t = GIMPLE_REGISTER_TYPE (t);
757
758 if (t == oldt)
759 {
760 /* The following re-creates proper variant lists while fixing up
761 the variant leaders. We do not stream TYPE_NEXT_VARIANT so the
762 variant list state before fixup is broken. */
763 tree tem, mv;
764
765 #ifdef ENABLE_CHECKING
766 /* Remove us from our main variant list if we are not the
767 variant leader. */
768 if (TYPE_MAIN_VARIANT (t) != t)
769 {
770 tem = TYPE_MAIN_VARIANT (t);
771 while (tem && TYPE_NEXT_VARIANT (tem) != t)
772 tem = TYPE_NEXT_VARIANT (tem);
773 gcc_assert (!tem && !TYPE_NEXT_VARIANT (t));
774 }
775 #endif
776
777 /* Query our new main variant. */
778 mv = GIMPLE_REGISTER_TYPE (TYPE_MAIN_VARIANT (t));
779
780 /* If we were the variant leader and we get replaced ourselves drop
781 all variants from our list. */
782 if (TYPE_MAIN_VARIANT (t) == t
783 && mv != t)
784 {
785 tem = t;
786 while (tem)
787 {
788 tree tem2 = TYPE_NEXT_VARIANT (tem);
789 TYPE_NEXT_VARIANT (tem) = NULL_TREE;
790 tem = tem2;
791 }
792 }
793
794 /* If we are not our own variant leader link us into our new leaders
795 variant list. */
796 if (mv != t)
797 {
798 TYPE_NEXT_VARIANT (t) = TYPE_NEXT_VARIANT (mv);
799 TYPE_NEXT_VARIANT (mv) = t;
800 if (RECORD_OR_UNION_TYPE_P (t))
801 TYPE_BINFO (t) = TYPE_BINFO (mv);
802 }
803
804 /* Finally adjust our main variant and fix it up. */
805 TYPE_MAIN_VARIANT (t) = mv;
806
807 /* The following reconstructs the pointer chains
808 of the new pointed-to type if we are a main variant. We do
809 not stream those so they are broken before fixup. */
810 if (TREE_CODE (t) == POINTER_TYPE
811 && TYPE_MAIN_VARIANT (t) == t)
812 {
813 TYPE_NEXT_PTR_TO (t) = TYPE_POINTER_TO (TREE_TYPE (t));
814 TYPE_POINTER_TO (TREE_TYPE (t)) = t;
815 }
816 else if (TREE_CODE (t) == REFERENCE_TYPE
817 && TYPE_MAIN_VARIANT (t) == t)
818 {
819 TYPE_NEXT_REF_TO (t) = TYPE_REFERENCE_TO (TREE_TYPE (t));
820 TYPE_REFERENCE_TO (TREE_TYPE (t)) = t;
821 }
822 }
823
824 else
825 {
826 if (RECORD_OR_UNION_TYPE_P (t))
827 {
828 tree f1, f2;
829 if (TYPE_FIELDS (t) != TYPE_FIELDS (oldt))
830 for (f1 = TYPE_FIELDS (t), f2 = TYPE_FIELDS (oldt);
831 f1 && f2; f1 = TREE_CHAIN (f1), f2 = TREE_CHAIN (f2))
832 {
833 unsigned ix;
834 gcc_assert (f1 != f2 && DECL_NAME (f1) == DECL_NAME (f2));
835 if (!streamer_tree_cache_lookup (cache, f2, &ix))
836 gcc_unreachable ();
837 /* If we're going to replace an element which we'd
838 still visit in the next iterations, we wouldn't
839 handle it, so do it here. We do have to handle it
840 even though the field_decl itself will be removed,
841 as it could refer to e.g. integer_cst which we
842 wouldn't reach via any other way, hence they
843 (and their type) would stay uncollected. */
844 /* ??? We should rather make sure to replace all
845 references to f2 with f1. That means handling
846 COMPONENT_REFs and CONSTRUCTOR elements in
847 lto_fixup_types and special-case the field-decl
848 operand handling. */
849 if (ix < i)
850 lto_fixup_types (f2);
851 streamer_tree_cache_insert_at (cache, f1, ix);
852 }
853 }
854
855 /* If we found a tree that is equal to oldt replace it in the
856 cache, so that further users (in the various LTO sections)
857 make use of it. */
858 streamer_tree_cache_insert_at (cache, t, i);
859 }
860 }
861
862 /* Finally compute the canonical type of all TREE_TYPEs and register
863 VAR_DECL and FUNCTION_DECL nodes in the symbol table.
864 From this point there are no longer any types with
865 TYPE_STRUCTURAL_EQUALITY_P and its type-based alias problems.
866 This step requires the TYPE_POINTER_TO lists being present, so
867 make sure it is done last. */
868 for (i = len; i-- > from;)
869 {
870 tree t = VEC_index (tree, cache->nodes, i);
871 if (t == NULL_TREE)
872 continue;
873
874 if (TREE_CODE (t) == VAR_DECL)
875 lto_register_var_decl_in_symtab (data_in, t);
876 else if (TREE_CODE (t) == FUNCTION_DECL && !DECL_BUILT_IN (t))
877 lto_register_function_decl_in_symtab (data_in, t);
878 else if (!flag_wpa
879 && TREE_CODE (t) == TYPE_DECL)
880 debug_hooks->type_decl (t, !DECL_FILE_SCOPE_P (t));
881 else if (TYPE_P (t) && !TYPE_CANONICAL (t))
882 TYPE_CANONICAL (t) = gimple_register_canonical_type (t);
883 }
884 }
885
886
887 /* Read all the symbols from buffer DATA, using descriptors in DECL_DATA.
888 RESOLUTIONS is the set of symbols picked by the linker (read from the
889 resolution file when the linker plugin is being used). */
890
891 static void
lto_read_decls(struct lto_file_decl_data * decl_data,const void * data,VEC (ld_plugin_symbol_resolution_t,heap)* resolutions)892 lto_read_decls (struct lto_file_decl_data *decl_data, const void *data,
893 VEC(ld_plugin_symbol_resolution_t,heap) *resolutions)
894 {
895 const struct lto_decl_header *header = (const struct lto_decl_header *) data;
896 const int decl_offset = sizeof (struct lto_decl_header);
897 const int main_offset = decl_offset + header->decl_state_size;
898 const int string_offset = main_offset + header->main_size;
899 struct lto_input_block ib_main;
900 struct data_in *data_in;
901 unsigned int i;
902 const uint32_t *data_ptr, *data_end;
903 uint32_t num_decl_states;
904
905 LTO_INIT_INPUT_BLOCK (ib_main, (const char *) data + main_offset, 0,
906 header->main_size);
907
908 data_in = lto_data_in_create (decl_data, (const char *) data + string_offset,
909 header->string_size, resolutions);
910
911 /* We do not uniquify the pre-loaded cache entries, those are middle-end
912 internal types that should not be merged. */
913
914 /* Read the global declarations and types. */
915 while (ib_main.p < ib_main.len)
916 {
917 tree t;
918 unsigned from = VEC_length (tree, data_in->reader_cache->nodes);
919 t = stream_read_tree (&ib_main, data_in);
920 gcc_assert (t && ib_main.p <= ib_main.len);
921 uniquify_nodes (data_in, from);
922 }
923
924 /* Read in lto_in_decl_state objects. */
925 data_ptr = (const uint32_t *) ((const char*) data + decl_offset);
926 data_end =
927 (const uint32_t *) ((const char*) data_ptr + header->decl_state_size);
928 num_decl_states = *data_ptr++;
929
930 gcc_assert (num_decl_states > 0);
931 decl_data->global_decl_state = lto_new_in_decl_state ();
932 data_ptr = lto_read_in_decl_state (data_in, data_ptr,
933 decl_data->global_decl_state);
934
935 /* Read in per-function decl states and enter them in hash table. */
936 decl_data->function_decl_states =
937 htab_create_ggc (37, lto_hash_in_decl_state, lto_eq_in_decl_state, NULL);
938
939 for (i = 1; i < num_decl_states; i++)
940 {
941 struct lto_in_decl_state *state = lto_new_in_decl_state ();
942 void **slot;
943
944 data_ptr = lto_read_in_decl_state (data_in, data_ptr, state);
945 slot = htab_find_slot (decl_data->function_decl_states, state, INSERT);
946 gcc_assert (*slot == NULL);
947 *slot = state;
948 }
949
950 if (data_ptr != data_end)
951 internal_error ("bytecode stream: garbage at the end of symbols section");
952
953 /* Set the current decl state to be the global state. */
954 decl_data->current_decl_state = decl_data->global_decl_state;
955
956 lto_data_in_delete (data_in);
957 }
958
959 /* Custom version of strtoll, which is not portable. */
960
961 static HOST_WIDEST_INT
lto_parse_hex(const char * p)962 lto_parse_hex (const char *p)
963 {
964 HOST_WIDEST_INT ret = 0;
965
966 for (; *p != '\0'; ++p)
967 {
968 char c = *p;
969 unsigned char part;
970 ret <<= 4;
971 if (c >= '0' && c <= '9')
972 part = c - '0';
973 else if (c >= 'a' && c <= 'f')
974 part = c - 'a' + 10;
975 else if (c >= 'A' && c <= 'F')
976 part = c - 'A' + 10;
977 else
978 internal_error ("could not parse hex number");
979 ret |= part;
980 }
981
982 return ret;
983 }
984
985 /* Read resolution for file named FILE_NAME. The resolution is read from
986 RESOLUTION. */
987
988 static void
lto_resolution_read(splay_tree file_ids,FILE * resolution,lto_file * file)989 lto_resolution_read (splay_tree file_ids, FILE *resolution, lto_file *file)
990 {
991 /* We require that objects in the resolution file are in the same
992 order as the lto1 command line. */
993 unsigned int name_len;
994 char *obj_name;
995 unsigned int num_symbols;
996 unsigned int i;
997 struct lto_file_decl_data *file_data;
998 splay_tree_node nd = NULL;
999
1000 if (!resolution)
1001 return;
1002
1003 name_len = strlen (file->filename);
1004 obj_name = XNEWVEC (char, name_len + 1);
1005 fscanf (resolution, " "); /* Read white space. */
1006
1007 fread (obj_name, sizeof (char), name_len, resolution);
1008 obj_name[name_len] = '\0';
1009 if (filename_cmp (obj_name, file->filename) != 0)
1010 internal_error ("unexpected file name %s in linker resolution file. "
1011 "Expected %s", obj_name, file->filename);
1012 if (file->offset != 0)
1013 {
1014 int t;
1015 char offset_p[17];
1016 HOST_WIDEST_INT offset;
1017 t = fscanf (resolution, "@0x%16s", offset_p);
1018 if (t != 1)
1019 internal_error ("could not parse file offset");
1020 offset = lto_parse_hex (offset_p);
1021 if (offset != file->offset)
1022 internal_error ("unexpected offset");
1023 }
1024
1025 free (obj_name);
1026
1027 fscanf (resolution, "%u", &num_symbols);
1028
1029 for (i = 0; i < num_symbols; i++)
1030 {
1031 int t;
1032 unsigned index;
1033 unsigned HOST_WIDE_INT id;
1034 char r_str[27];
1035 enum ld_plugin_symbol_resolution r = (enum ld_plugin_symbol_resolution) 0;
1036 unsigned int j;
1037 unsigned int lto_resolution_str_len =
1038 sizeof (lto_resolution_str) / sizeof (char *);
1039 res_pair rp;
1040
1041 t = fscanf (resolution, "%u " HOST_WIDE_INT_PRINT_HEX_PURE " %26s %*[^\n]\n",
1042 &index, &id, r_str);
1043 if (t != 3)
1044 internal_error ("invalid line in the resolution file");
1045
1046 for (j = 0; j < lto_resolution_str_len; j++)
1047 {
1048 if (strcmp (lto_resolution_str[j], r_str) == 0)
1049 {
1050 r = (enum ld_plugin_symbol_resolution) j;
1051 break;
1052 }
1053 }
1054 if (j == lto_resolution_str_len)
1055 internal_error ("invalid resolution in the resolution file");
1056
1057 if (!(nd && lto_splay_tree_id_equal_p (nd->key, id)))
1058 {
1059 nd = lto_splay_tree_lookup (file_ids, id);
1060 if (nd == NULL)
1061 internal_error ("resolution sub id %wx not in object file", id);
1062 }
1063
1064 file_data = (struct lto_file_decl_data *)nd->value;
1065 /* The indexes are very sparse. To save memory save them in a compact
1066 format that is only unpacked later when the subfile is processed. */
1067 rp.res = r;
1068 rp.index = index;
1069 VEC_safe_push (res_pair, heap, file_data->respairs, &rp);
1070 if (file_data->max_index < index)
1071 file_data->max_index = index;
1072 }
1073 }
1074
1075 /* List of file_decl_datas */
1076 struct file_data_list
1077 {
1078 struct lto_file_decl_data *first, *last;
1079 };
1080
1081 /* Is the name for a id'ed LTO section? */
1082
1083 static int
lto_section_with_id(const char * name,unsigned HOST_WIDE_INT * id)1084 lto_section_with_id (const char *name, unsigned HOST_WIDE_INT *id)
1085 {
1086 const char *s;
1087
1088 if (strncmp (name, LTO_SECTION_NAME_PREFIX, strlen (LTO_SECTION_NAME_PREFIX)))
1089 return 0;
1090 s = strrchr (name, '.');
1091 return s && sscanf (s, "." HOST_WIDE_INT_PRINT_HEX_PURE, id) == 1;
1092 }
1093
1094 /* Create file_data of each sub file id */
1095
1096 static int
create_subid_section_table(struct lto_section_slot * ls,splay_tree file_ids,struct file_data_list * list)1097 create_subid_section_table (struct lto_section_slot *ls, splay_tree file_ids,
1098 struct file_data_list *list)
1099 {
1100 struct lto_section_slot s_slot, *new_slot;
1101 unsigned HOST_WIDE_INT id;
1102 splay_tree_node nd;
1103 void **hash_slot;
1104 char *new_name;
1105 struct lto_file_decl_data *file_data;
1106
1107 if (!lto_section_with_id (ls->name, &id))
1108 return 1;
1109
1110 /* Find hash table of sub module id */
1111 nd = lto_splay_tree_lookup (file_ids, id);
1112 if (nd != NULL)
1113 {
1114 file_data = (struct lto_file_decl_data *)nd->value;
1115 }
1116 else
1117 {
1118 file_data = ggc_alloc_lto_file_decl_data ();
1119 memset(file_data, 0, sizeof (struct lto_file_decl_data));
1120 file_data->id = id;
1121 file_data->section_hash_table = lto_obj_create_section_hash_table ();;
1122 lto_splay_tree_insert (file_ids, id, file_data);
1123
1124 /* Maintain list in linker order */
1125 if (!list->first)
1126 list->first = file_data;
1127 if (list->last)
1128 list->last->next = file_data;
1129 list->last = file_data;
1130 }
1131
1132 /* Copy section into sub module hash table */
1133 new_name = XDUPVEC (char, ls->name, strlen (ls->name) + 1);
1134 s_slot.name = new_name;
1135 hash_slot = htab_find_slot (file_data->section_hash_table, &s_slot, INSERT);
1136 gcc_assert (*hash_slot == NULL);
1137
1138 new_slot = XDUP (struct lto_section_slot, ls);
1139 new_slot->name = new_name;
1140 *hash_slot = new_slot;
1141 return 1;
1142 }
1143
1144 /* Read declarations and other initializations for a FILE_DATA. */
1145
1146 static void
lto_file_finalize(struct lto_file_decl_data * file_data,lto_file * file)1147 lto_file_finalize (struct lto_file_decl_data *file_data, lto_file *file)
1148 {
1149 const char *data;
1150 size_t len;
1151 VEC(ld_plugin_symbol_resolution_t,heap) *resolutions = NULL;
1152 int i;
1153 res_pair *rp;
1154
1155 /* Create vector for fast access of resolution. We do this lazily
1156 to save memory. */
1157 VEC_safe_grow_cleared (ld_plugin_symbol_resolution_t, heap,
1158 resolutions,
1159 file_data->max_index + 1);
1160 for (i = 0; VEC_iterate (res_pair, file_data->respairs, i, rp); i++)
1161 VEC_replace (ld_plugin_symbol_resolution_t, resolutions, rp->index, rp->res);
1162 VEC_free (res_pair, heap, file_data->respairs);
1163
1164 file_data->renaming_hash_table = lto_create_renaming_table ();
1165 file_data->file_name = file->filename;
1166 data = lto_get_section_data (file_data, LTO_section_decls, NULL, &len);
1167 if (data == NULL)
1168 {
1169 internal_error ("cannot read LTO decls from %s", file_data->file_name);
1170 return;
1171 }
1172 /* Frees resolutions */
1173 lto_read_decls (file_data, data, resolutions);
1174 lto_free_section_data (file_data, LTO_section_decls, NULL, data, len);
1175 }
1176
1177 /* Finalize FILE_DATA in FILE and increase COUNT. */
1178
1179 static int
lto_create_files_from_ids(lto_file * file,struct lto_file_decl_data * file_data,int * count)1180 lto_create_files_from_ids (lto_file *file, struct lto_file_decl_data *file_data,
1181 int *count)
1182 {
1183 lto_file_finalize (file_data, file);
1184 if (cgraph_dump_file)
1185 fprintf (cgraph_dump_file, "Creating file %s with sub id " HOST_WIDE_INT_PRINT_HEX "\n",
1186 file_data->file_name, file_data->id);
1187 (*count)++;
1188 return 0;
1189 }
1190
1191 /* Generate a TREE representation for all types and external decls
1192 entities in FILE.
1193
1194 Read all of the globals out of the file. Then read the cgraph
1195 and process the .o index into the cgraph nodes so that it can open
1196 the .o file to load the functions and ipa information. */
1197
1198 static struct lto_file_decl_data *
lto_file_read(lto_file * file,FILE * resolution_file,int * count)1199 lto_file_read (lto_file *file, FILE *resolution_file, int *count)
1200 {
1201 struct lto_file_decl_data *file_data = NULL;
1202 splay_tree file_ids;
1203 htab_t section_hash_table;
1204 struct lto_section_slot *section;
1205 struct file_data_list file_list;
1206 struct lto_section_list section_list;
1207
1208 memset (§ion_list, 0, sizeof (struct lto_section_list));
1209 section_hash_table = lto_obj_build_section_table (file, §ion_list);
1210
1211 /* Find all sub modules in the object and put their sections into new hash
1212 tables in a splay tree. */
1213 file_ids = lto_splay_tree_new ();
1214 memset (&file_list, 0, sizeof (struct file_data_list));
1215 for (section = section_list.first; section != NULL; section = section->next)
1216 create_subid_section_table (section, file_ids, &file_list);
1217
1218 /* Add resolutions to file ids */
1219 lto_resolution_read (file_ids, resolution_file, file);
1220
1221 /* Finalize each lto file for each submodule in the merged object */
1222 for (file_data = file_list.first; file_data != NULL; file_data = file_data->next)
1223 lto_create_files_from_ids (file, file_data, count);
1224
1225 splay_tree_delete (file_ids);
1226 htab_delete (section_hash_table);
1227
1228 return file_list.first;
1229 }
1230
1231 #if HAVE_MMAP_FILE && HAVE_SYSCONF && defined _SC_PAGE_SIZE
1232 #define LTO_MMAP_IO 1
1233 #endif
1234
1235 #if LTO_MMAP_IO
1236 /* Page size of machine is used for mmap and munmap calls. */
1237 static size_t page_mask;
1238 #endif
1239
1240 /* Get the section data of length LEN from FILENAME starting at
1241 OFFSET. The data segment must be freed by the caller when the
1242 caller is finished. Returns NULL if all was not well. */
1243
1244 static char *
lto_read_section_data(struct lto_file_decl_data * file_data,intptr_t offset,size_t len)1245 lto_read_section_data (struct lto_file_decl_data *file_data,
1246 intptr_t offset, size_t len)
1247 {
1248 char *result;
1249 static int fd = -1;
1250 static char *fd_name;
1251 #if LTO_MMAP_IO
1252 intptr_t computed_len;
1253 intptr_t computed_offset;
1254 intptr_t diff;
1255 #endif
1256
1257 /* Keep a single-entry file-descriptor cache. The last file we
1258 touched will get closed at exit.
1259 ??? Eventually we want to add a more sophisticated larger cache
1260 or rather fix function body streaming to not stream them in
1261 practically random order. */
1262 if (fd != -1
1263 && filename_cmp (fd_name, file_data->file_name) != 0)
1264 {
1265 free (fd_name);
1266 close (fd);
1267 fd = -1;
1268 }
1269 if (fd == -1)
1270 {
1271 fd = open (file_data->file_name, O_RDONLY|O_BINARY);
1272 if (fd == -1)
1273 {
1274 fatal_error ("Cannot open %s", file_data->file_name);
1275 return NULL;
1276 }
1277 fd_name = xstrdup (file_data->file_name);
1278 }
1279
1280 #if LTO_MMAP_IO
1281 if (!page_mask)
1282 {
1283 size_t page_size = sysconf (_SC_PAGE_SIZE);
1284 page_mask = ~(page_size - 1);
1285 }
1286
1287 computed_offset = offset & page_mask;
1288 diff = offset - computed_offset;
1289 computed_len = len + diff;
1290
1291 result = (char *) mmap (NULL, computed_len, PROT_READ, MAP_PRIVATE,
1292 fd, computed_offset);
1293 if (result == MAP_FAILED)
1294 {
1295 fatal_error ("Cannot map %s", file_data->file_name);
1296 return NULL;
1297 }
1298
1299 return result + diff;
1300 #else
1301 result = (char *) xmalloc (len);
1302 if (lseek (fd, offset, SEEK_SET) != offset
1303 || read (fd, result, len) != (ssize_t) len)
1304 {
1305 free (result);
1306 fatal_error ("Cannot read %s", file_data->file_name);
1307 result = NULL;
1308 }
1309 #ifdef __MINGW32__
1310 /* Native windows doesn't supports delayed unlink on opened file. So
1311 we close file here again. This produces higher I/O load, but at least
1312 it prevents to have dangling file handles preventing unlink. */
1313 free (fd_name);
1314 fd_name = NULL;
1315 close (fd);
1316 fd = -1;
1317 #endif
1318 return result;
1319 #endif
1320 }
1321
1322
1323 /* Get the section data from FILE_DATA of SECTION_TYPE with NAME.
1324 NAME will be NULL unless the section type is for a function
1325 body. */
1326
1327 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)1328 get_section_data (struct lto_file_decl_data *file_data,
1329 enum lto_section_type section_type,
1330 const char *name,
1331 size_t *len)
1332 {
1333 htab_t section_hash_table = file_data->section_hash_table;
1334 struct lto_section_slot *f_slot;
1335 struct lto_section_slot s_slot;
1336 const char *section_name = lto_get_section_name (section_type, name, file_data);
1337 char *data = NULL;
1338
1339 *len = 0;
1340 s_slot.name = section_name;
1341 f_slot = (struct lto_section_slot *) htab_find (section_hash_table, &s_slot);
1342 if (f_slot)
1343 {
1344 data = lto_read_section_data (file_data, f_slot->start, f_slot->len);
1345 *len = f_slot->len;
1346 }
1347
1348 free (CONST_CAST (char *, section_name));
1349 return data;
1350 }
1351
1352
1353 /* Free the section data from FILE_DATA of SECTION_TYPE with NAME that
1354 starts at OFFSET and has LEN bytes. */
1355
1356 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)1357 free_section_data (struct lto_file_decl_data *file_data ATTRIBUTE_UNUSED,
1358 enum lto_section_type section_type ATTRIBUTE_UNUSED,
1359 const char *name ATTRIBUTE_UNUSED,
1360 const char *offset, size_t len ATTRIBUTE_UNUSED)
1361 {
1362 #if LTO_MMAP_IO
1363 intptr_t computed_len;
1364 intptr_t computed_offset;
1365 intptr_t diff;
1366 #endif
1367
1368 #if LTO_MMAP_IO
1369 computed_offset = ((intptr_t) offset) & page_mask;
1370 diff = (intptr_t) offset - computed_offset;
1371 computed_len = len + diff;
1372
1373 munmap ((caddr_t) computed_offset, computed_len);
1374 #else
1375 free (CONST_CAST(char *, offset));
1376 #endif
1377 }
1378
1379 /* Structure describing ltrans partitions. */
1380
1381 struct ltrans_partition_def
1382 {
1383 cgraph_node_set cgraph_set;
1384 varpool_node_set varpool_set;
1385 const char * name;
1386 int insns;
1387 };
1388
1389 typedef struct ltrans_partition_def *ltrans_partition;
1390 DEF_VEC_P(ltrans_partition);
1391 DEF_VEC_ALLOC_P(ltrans_partition,heap);
1392
1393 static VEC(ltrans_partition, heap) *ltrans_partitions;
1394
1395 static void add_cgraph_node_to_partition (ltrans_partition part, struct cgraph_node *node);
1396 static void add_varpool_node_to_partition (ltrans_partition part, struct varpool_node *vnode);
1397
1398 /* Create new partition with name NAME. */
1399 static ltrans_partition
new_partition(const char * name)1400 new_partition (const char *name)
1401 {
1402 ltrans_partition part = XCNEW (struct ltrans_partition_def);
1403 part->cgraph_set = cgraph_node_set_new ();
1404 part->varpool_set = varpool_node_set_new ();
1405 part->name = name;
1406 part->insns = 0;
1407 VEC_safe_push (ltrans_partition, heap, ltrans_partitions, part);
1408 return part;
1409 }
1410
1411 /* Free memory used by ltrans datastructures. */
1412 static void
free_ltrans_partitions(void)1413 free_ltrans_partitions (void)
1414 {
1415 unsigned int idx;
1416 ltrans_partition part;
1417 for (idx = 0; VEC_iterate (ltrans_partition, ltrans_partitions, idx, part); idx++)
1418 {
1419 free_cgraph_node_set (part->cgraph_set);
1420 free (part);
1421 }
1422 VEC_free (ltrans_partition, heap, ltrans_partitions);
1423 }
1424
1425 /* See all references that go to comdat objects and bring them into partition too. */
1426 static void
add_references_to_partition(ltrans_partition part,struct ipa_ref_list * refs)1427 add_references_to_partition (ltrans_partition part, struct ipa_ref_list *refs)
1428 {
1429 int i;
1430 struct ipa_ref *ref;
1431 for (i = 0; ipa_ref_list_reference_iterate (refs, i, ref); i++)
1432 {
1433 if (ref->refered_type == IPA_REF_CGRAPH
1434 && DECL_COMDAT (cgraph_function_node (ipa_ref_node (ref), NULL)->decl)
1435 && !cgraph_node_in_set_p (ipa_ref_node (ref), part->cgraph_set))
1436 add_cgraph_node_to_partition (part, ipa_ref_node (ref));
1437 else
1438 if (ref->refered_type == IPA_REF_VARPOOL
1439 && DECL_COMDAT (ipa_ref_varpool_node (ref)->decl)
1440 && !varpool_node_in_set_p (ipa_ref_varpool_node (ref), part->varpool_set))
1441 add_varpool_node_to_partition (part, ipa_ref_varpool_node (ref));
1442 }
1443 }
1444
1445 /* Worker for add_cgraph_node_to_partition. */
1446
1447 static bool
add_cgraph_node_to_partition_1(struct cgraph_node * node,void * data)1448 add_cgraph_node_to_partition_1 (struct cgraph_node *node, void *data)
1449 {
1450 ltrans_partition part = (ltrans_partition) data;
1451
1452 /* non-COMDAT aliases of COMDAT functions needs to be output just once. */
1453 if (!DECL_COMDAT (node->decl)
1454 && !node->global.inlined_to
1455 && node->aux)
1456 {
1457 gcc_assert (node->thunk.thunk_p || node->alias);
1458 return false;
1459 }
1460
1461 if (node->aux)
1462 {
1463 node->in_other_partition = 1;
1464 if (cgraph_dump_file)
1465 fprintf (cgraph_dump_file, "Node %s/%i now used in multiple partitions\n",
1466 cgraph_node_name (node), node->uid);
1467 }
1468 node->aux = (void *)((size_t)node->aux + 1);
1469 cgraph_node_set_add (part->cgraph_set, node);
1470 return false;
1471 }
1472
1473 /* Add NODE to partition as well as the inline callees and referred comdats into partition PART. */
1474
1475 static void
add_cgraph_node_to_partition(ltrans_partition part,struct cgraph_node * node)1476 add_cgraph_node_to_partition (ltrans_partition part, struct cgraph_node *node)
1477 {
1478 struct cgraph_edge *e;
1479 cgraph_node_set_iterator csi;
1480 struct cgraph_node *n;
1481
1482 /* We always decide on functions, not associated thunks and aliases. */
1483 node = cgraph_function_node (node, NULL);
1484
1485 /* If NODE is already there, we have nothing to do. */
1486 csi = cgraph_node_set_find (part->cgraph_set, node);
1487 if (!csi_end_p (csi))
1488 return;
1489
1490 cgraph_for_node_thunks_and_aliases (node, add_cgraph_node_to_partition_1, part, true);
1491
1492 part->insns += inline_summary (node)->self_size;
1493
1494
1495 cgraph_node_set_add (part->cgraph_set, node);
1496
1497 for (e = node->callees; e; e = e->next_callee)
1498 if ((!e->inline_failed
1499 || DECL_COMDAT (cgraph_function_node (e->callee, NULL)->decl))
1500 && !cgraph_node_in_set_p (e->callee, part->cgraph_set))
1501 add_cgraph_node_to_partition (part, e->callee);
1502
1503 add_references_to_partition (part, &node->ref_list);
1504
1505 if (node->same_comdat_group)
1506 for (n = node->same_comdat_group; n != node; n = n->same_comdat_group)
1507 add_cgraph_node_to_partition (part, n);
1508 }
1509
1510 /* Add VNODE to partition as well as comdat references partition PART. */
1511
1512 static void
add_varpool_node_to_partition(ltrans_partition part,struct varpool_node * vnode)1513 add_varpool_node_to_partition (ltrans_partition part, struct varpool_node *vnode)
1514 {
1515 varpool_node_set_iterator vsi;
1516
1517 vnode = varpool_variable_node (vnode, NULL);
1518
1519 /* If NODE is already there, we have nothing to do. */
1520 vsi = varpool_node_set_find (part->varpool_set, vnode);
1521 if (!vsi_end_p (vsi))
1522 return;
1523
1524 varpool_node_set_add (part->varpool_set, vnode);
1525
1526 if (vnode->aux)
1527 {
1528 vnode->in_other_partition = 1;
1529 if (cgraph_dump_file)
1530 fprintf (cgraph_dump_file, "Varpool node %s now used in multiple partitions\n",
1531 varpool_node_name (vnode));
1532 }
1533 vnode->aux = (void *)((size_t)vnode->aux + 1);
1534
1535 add_references_to_partition (part, &vnode->ref_list);
1536
1537 if (vnode->same_comdat_group
1538 && !varpool_node_in_set_p (vnode->same_comdat_group, part->varpool_set))
1539 add_varpool_node_to_partition (part, vnode->same_comdat_group);
1540 }
1541
1542 /* Undo all additions until number of cgraph nodes in PARITION is N_CGRAPH_NODES
1543 and number of varpool nodes is N_VARPOOL_NODES. */
1544
1545 static void
undo_partition(ltrans_partition partition,unsigned int n_cgraph_nodes,unsigned int n_varpool_nodes)1546 undo_partition (ltrans_partition partition, unsigned int n_cgraph_nodes,
1547 unsigned int n_varpool_nodes)
1548 {
1549 while (VEC_length (cgraph_node_ptr, partition->cgraph_set->nodes) >
1550 n_cgraph_nodes)
1551 {
1552 struct cgraph_node *node = VEC_index (cgraph_node_ptr,
1553 partition->cgraph_set->nodes,
1554 n_cgraph_nodes);
1555 partition->insns -= inline_summary (node)->self_size;
1556 cgraph_node_set_remove (partition->cgraph_set, node);
1557 node->aux = (void *)((size_t)node->aux - 1);
1558 }
1559 while (VEC_length (varpool_node_ptr, partition->varpool_set->nodes) >
1560 n_varpool_nodes)
1561 {
1562 struct varpool_node *node = VEC_index (varpool_node_ptr,
1563 partition->varpool_set->nodes,
1564 n_varpool_nodes);
1565 varpool_node_set_remove (partition->varpool_set, node);
1566 node->aux = (void *)((size_t)node->aux - 1);
1567 }
1568 }
1569
1570 /* Return true if NODE should be partitioned.
1571 This means that partitioning algorithm should put NODE into one of partitions.
1572 This apply to most functions with bodies. Functions that are not partitions
1573 are put into every unit needing them. This is the case of i.e. COMDATs. */
1574
1575 static bool
partition_cgraph_node_p(struct cgraph_node * node)1576 partition_cgraph_node_p (struct cgraph_node *node)
1577 {
1578 /* We will get proper partition based on function they are inlined to. */
1579 if (node->global.inlined_to)
1580 return false;
1581 /* Nodes without a body do not need partitioning. */
1582 if (!node->analyzed)
1583 return false;
1584 /* Extern inlines and comdat are always only in partitions they are needed. */
1585 if (DECL_EXTERNAL (node->decl)
1586 || (DECL_COMDAT (node->decl)
1587 && !cgraph_used_from_object_file_p (node)))
1588 return false;
1589 if (lookup_attribute ("weakref", DECL_ATTRIBUTES (node->decl)))
1590 return false;
1591 return true;
1592 }
1593
1594 /* Return true if VNODE should be partitioned.
1595 This means that partitioning algorithm should put VNODE into one of partitions. */
1596
1597 static bool
partition_varpool_node_p(struct varpool_node * vnode)1598 partition_varpool_node_p (struct varpool_node *vnode)
1599 {
1600 if (vnode->alias || !vnode->needed)
1601 return false;
1602 /* Constant pool and comdat are always only in partitions they are needed. */
1603 if (DECL_IN_CONSTANT_POOL (vnode->decl)
1604 || (DECL_COMDAT (vnode->decl)
1605 && !vnode->force_output
1606 && !varpool_used_from_object_file_p (vnode)))
1607 return false;
1608 if (lookup_attribute ("weakref", DECL_ATTRIBUTES (vnode->decl)))
1609 return false;
1610 return true;
1611 }
1612
1613 /* Group cgrah nodes by input files. This is used mainly for testing
1614 right now. */
1615
1616 static void
lto_1_to_1_map(void)1617 lto_1_to_1_map (void)
1618 {
1619 struct cgraph_node *node;
1620 struct varpool_node *vnode;
1621 struct lto_file_decl_data *file_data;
1622 struct pointer_map_t *pmap;
1623 ltrans_partition partition;
1624 void **slot;
1625 int npartitions = 0;
1626
1627 timevar_push (TV_WHOPR_WPA);
1628
1629 pmap = pointer_map_create ();
1630
1631 for (node = cgraph_nodes; node; node = node->next)
1632 {
1633 if (!partition_cgraph_node_p (node)
1634 || node->aux)
1635 continue;
1636
1637 file_data = node->local.lto_file_data;
1638
1639 if (file_data)
1640 {
1641 slot = pointer_map_contains (pmap, file_data);
1642 if (slot)
1643 partition = (ltrans_partition) *slot;
1644 else
1645 {
1646 partition = new_partition (file_data->file_name);
1647 slot = pointer_map_insert (pmap, file_data);
1648 *slot = partition;
1649 npartitions++;
1650 }
1651 }
1652 else if (!file_data
1653 && VEC_length (ltrans_partition, ltrans_partitions))
1654 partition = VEC_index (ltrans_partition, ltrans_partitions, 0);
1655 else
1656 {
1657 partition = new_partition ("");
1658 slot = pointer_map_insert (pmap, NULL);
1659 *slot = partition;
1660 npartitions++;
1661 }
1662
1663 add_cgraph_node_to_partition (partition, node);
1664 }
1665
1666 for (vnode = varpool_nodes; vnode; vnode = vnode->next)
1667 {
1668 if (!partition_varpool_node_p (vnode)
1669 || vnode->aux)
1670 continue;
1671 file_data = vnode->lto_file_data;
1672 slot = pointer_map_contains (pmap, file_data);
1673 if (slot)
1674 partition = (ltrans_partition) *slot;
1675 else
1676 {
1677 partition = new_partition (file_data->file_name);
1678 slot = pointer_map_insert (pmap, file_data);
1679 *slot = partition;
1680 npartitions++;
1681 }
1682
1683 add_varpool_node_to_partition (partition, vnode);
1684 }
1685 for (node = cgraph_nodes; node; node = node->next)
1686 node->aux = NULL;
1687 for (vnode = varpool_nodes; vnode; vnode = vnode->next)
1688 vnode->aux = NULL;
1689
1690 /* If the cgraph is empty, create one cgraph node set so that there is still
1691 an output file for any variables that need to be exported in a DSO. */
1692 if (!npartitions)
1693 new_partition ("empty");
1694
1695 pointer_map_destroy (pmap);
1696
1697 timevar_pop (TV_WHOPR_WPA);
1698
1699 lto_stats.num_cgraph_partitions += VEC_length (ltrans_partition,
1700 ltrans_partitions);
1701 }
1702
1703 /* Helper function for qsort; sort nodes by order. */
1704 static int
node_cmp(const void * pa,const void * pb)1705 node_cmp (const void *pa, const void *pb)
1706 {
1707 const struct cgraph_node *a = *(const struct cgraph_node * const *) pa;
1708 const struct cgraph_node *b = *(const struct cgraph_node * const *) pb;
1709 return b->order - a->order;
1710 }
1711
1712 /* Helper function for qsort; sort nodes by order. */
1713 static int
varpool_node_cmp(const void * pa,const void * pb)1714 varpool_node_cmp (const void *pa, const void *pb)
1715 {
1716 const struct varpool_node *a = *(const struct varpool_node * const *) pa;
1717 const struct varpool_node *b = *(const struct varpool_node * const *) pb;
1718 return b->order - a->order;
1719 }
1720
1721 /* Group cgraph nodes into equally-sized partitions.
1722
1723 The partitioning algorithm is simple: nodes are taken in predefined order.
1724 The order corresponds to the order we want functions to have in the final
1725 output. In the future this will be given by function reordering pass, but
1726 at the moment we use the topological order, which is a good approximation.
1727
1728 The goal is to partition this linear order into intervals (partitions) so
1729 that all the partitions have approximately the same size and the number of
1730 callgraph or IPA reference edges crossing boundaries is minimal.
1731
1732 This is a lot faster (O(n) in size of callgraph) than algorithms doing
1733 priority-based graph clustering that are generally O(n^2) and, since
1734 WHOPR is designed to make things go well across partitions, it leads
1735 to good results.
1736
1737 We compute the expected size of a partition as:
1738
1739 max (total_size / lto_partitions, min_partition_size)
1740
1741 We use dynamic expected size of partition so small programs are partitioned
1742 into enough partitions to allow use of multiple CPUs, while large programs
1743 are not partitioned too much. Creating too many partitions significantly
1744 increases the streaming overhead.
1745
1746 In the future, we would like to bound the maximal size of partitions so as
1747 to prevent the LTRANS stage from consuming too much memory. At the moment,
1748 however, the WPA stage is the most memory intensive for large benchmarks,
1749 since too many types and declarations are read into memory.
1750
1751 The function implements a simple greedy algorithm. Nodes are being added
1752 to the current partition until after 3/4 of the expected partition size is
1753 reached. Past this threshold, we keep track of boundary size (number of
1754 edges going to other partitions) and continue adding functions until after
1755 the current partition has grown to twice the expected partition size. Then
1756 the process is undone to the point where the minimal ratio of boundary size
1757 and in-partition calls was reached. */
1758
1759 static void
lto_balanced_map(void)1760 lto_balanced_map (void)
1761 {
1762 int n_nodes = 0;
1763 int n_varpool_nodes = 0, varpool_pos = 0;
1764 struct cgraph_node **postorder =
1765 XCNEWVEC (struct cgraph_node *, cgraph_n_nodes);
1766 struct cgraph_node **order = XNEWVEC (struct cgraph_node *, cgraph_max_uid);
1767 struct varpool_node **varpool_order = NULL;
1768 int i, postorder_len;
1769 struct cgraph_node *node;
1770 int total_size = 0, best_total_size = 0;
1771 int partition_size;
1772 ltrans_partition partition;
1773 unsigned int last_visited_cgraph_node = 0, last_visited_varpool_node = 0;
1774 struct varpool_node *vnode;
1775 int cost = 0, internal = 0;
1776 int best_n_nodes = 0, best_n_varpool_nodes = 0, best_i = 0, best_cost =
1777 INT_MAX, best_internal = 0;
1778 int npartitions;
1779 int current_order = -1;
1780
1781 for (vnode = varpool_nodes; vnode; vnode = vnode->next)
1782 gcc_assert (!vnode->aux);
1783 /* Until we have better ordering facility, use toplogical order.
1784 Include only nodes we will partition and compute estimate of program
1785 size. Note that since nodes that are not partitioned might be put into
1786 multiple partitions, this is just an estimate of real size. This is why
1787 we keep partition_size updated after every partition is finalized. */
1788 postorder_len = ipa_reverse_postorder (postorder);
1789
1790 for (i = 0; i < postorder_len; i++)
1791 {
1792 node = postorder[i];
1793 if (partition_cgraph_node_p (node))
1794 {
1795 order[n_nodes++] = node;
1796 total_size += inline_summary (node)->size;
1797 }
1798 }
1799 free (postorder);
1800
1801 if (!flag_toplevel_reorder)
1802 {
1803 qsort (order, n_nodes, sizeof (struct cgraph_node *), node_cmp);
1804
1805 for (vnode = varpool_nodes; vnode; vnode = vnode->next)
1806 if (partition_varpool_node_p (vnode))
1807 n_varpool_nodes++;
1808 varpool_order = XNEWVEC (struct varpool_node *, n_varpool_nodes);
1809
1810 n_varpool_nodes = 0;
1811 for (vnode = varpool_nodes; vnode; vnode = vnode->next)
1812 if (partition_varpool_node_p (vnode))
1813 varpool_order[n_varpool_nodes++] = vnode;
1814 qsort (varpool_order, n_varpool_nodes, sizeof (struct varpool_node *),
1815 varpool_node_cmp);
1816 }
1817
1818 /* Compute partition size and create the first partition. */
1819 partition_size = total_size / PARAM_VALUE (PARAM_LTO_PARTITIONS);
1820 if (partition_size < PARAM_VALUE (MIN_PARTITION_SIZE))
1821 partition_size = PARAM_VALUE (MIN_PARTITION_SIZE);
1822 npartitions = 1;
1823 partition = new_partition ("");
1824 if (cgraph_dump_file)
1825 fprintf (cgraph_dump_file, "Total unit size: %i, partition size: %i\n",
1826 total_size, partition_size);
1827
1828 for (i = 0; i < n_nodes; i++)
1829 {
1830 if (order[i]->aux)
1831 continue;
1832
1833 current_order = order[i]->order;
1834
1835 if (!flag_toplevel_reorder)
1836 while (varpool_pos < n_varpool_nodes && varpool_order[varpool_pos]->order < current_order)
1837 {
1838 if (!varpool_order[varpool_pos]->aux)
1839 add_varpool_node_to_partition (partition, varpool_order[varpool_pos]);
1840 varpool_pos++;
1841 }
1842
1843 add_cgraph_node_to_partition (partition, order[i]);
1844 total_size -= inline_summary (order[i])->size;
1845
1846
1847 /* Once we added a new node to the partition, we also want to add
1848 all referenced variables unless they was already added into some
1849 earlier partition.
1850 add_cgraph_node_to_partition adds possibly multiple nodes and
1851 variables that are needed to satisfy needs of ORDER[i].
1852 We remember last visited cgraph and varpool node from last iteration
1853 of outer loop that allows us to process every new addition.
1854
1855 At the same time we compute size of the boundary into COST. Every
1856 callgraph or IPA reference edge leaving the partition contributes into
1857 COST. Every edge inside partition was earlier computed as one leaving
1858 it and thus we need to subtract it from COST. */
1859 while (last_visited_cgraph_node <
1860 VEC_length (cgraph_node_ptr, partition->cgraph_set->nodes)
1861 || last_visited_varpool_node < VEC_length (varpool_node_ptr,
1862 partition->varpool_set->
1863 nodes))
1864 {
1865 struct ipa_ref_list *refs;
1866 int j;
1867 struct ipa_ref *ref;
1868 bool cgraph_p = false;
1869
1870 if (last_visited_cgraph_node <
1871 VEC_length (cgraph_node_ptr, partition->cgraph_set->nodes))
1872 {
1873 struct cgraph_edge *edge;
1874
1875 cgraph_p = true;
1876 node = VEC_index (cgraph_node_ptr, partition->cgraph_set->nodes,
1877 last_visited_cgraph_node);
1878 refs = &node->ref_list;
1879
1880 last_visited_cgraph_node++;
1881
1882 gcc_assert (node->analyzed);
1883
1884 /* Compute boundary cost of callgraph edges. */
1885 for (edge = node->callees; edge; edge = edge->next_callee)
1886 if (edge->callee->analyzed)
1887 {
1888 int edge_cost = edge->frequency;
1889 cgraph_node_set_iterator csi;
1890
1891 if (!edge_cost)
1892 edge_cost = 1;
1893 gcc_assert (edge_cost > 0);
1894 csi = cgraph_node_set_find (partition->cgraph_set, edge->callee);
1895 if (!csi_end_p (csi)
1896 && csi.index < last_visited_cgraph_node - 1)
1897 cost -= edge_cost, internal+= edge_cost;
1898 else
1899 cost += edge_cost;
1900 }
1901 for (edge = node->callers; edge; edge = edge->next_caller)
1902 {
1903 int edge_cost = edge->frequency;
1904 cgraph_node_set_iterator csi;
1905
1906 gcc_assert (edge->caller->analyzed);
1907 if (!edge_cost)
1908 edge_cost = 1;
1909 gcc_assert (edge_cost > 0);
1910 csi = cgraph_node_set_find (partition->cgraph_set, edge->caller);
1911 if (!csi_end_p (csi)
1912 && csi.index < last_visited_cgraph_node)
1913 cost -= edge_cost;
1914 else
1915 cost += edge_cost;
1916 }
1917 }
1918 else
1919 {
1920 refs =
1921 &VEC_index (varpool_node_ptr, partition->varpool_set->nodes,
1922 last_visited_varpool_node)->ref_list;
1923 last_visited_varpool_node++;
1924 }
1925
1926 /* Compute boundary cost of IPA REF edges and at the same time look into
1927 variables referenced from current partition and try to add them. */
1928 for (j = 0; ipa_ref_list_reference_iterate (refs, j, ref); j++)
1929 if (ref->refered_type == IPA_REF_VARPOOL)
1930 {
1931 varpool_node_set_iterator vsi;
1932
1933 vnode = ipa_ref_varpool_node (ref);
1934 if (!vnode->finalized)
1935 continue;
1936 if (!vnode->aux && flag_toplevel_reorder
1937 && partition_varpool_node_p (vnode))
1938 add_varpool_node_to_partition (partition, vnode);
1939 vsi = varpool_node_set_find (partition->varpool_set, vnode);
1940 if (!vsi_end_p (vsi)
1941 && vsi.index < last_visited_varpool_node - !cgraph_p)
1942 cost--, internal++;
1943 else
1944 cost++;
1945 }
1946 else
1947 {
1948 cgraph_node_set_iterator csi;
1949
1950 node = ipa_ref_node (ref);
1951 if (!node->analyzed)
1952 continue;
1953 csi = cgraph_node_set_find (partition->cgraph_set, node);
1954 if (!csi_end_p (csi)
1955 && csi.index < last_visited_cgraph_node - cgraph_p)
1956 cost--, internal++;
1957 else
1958 cost++;
1959 }
1960 for (j = 0; ipa_ref_list_refering_iterate (refs, j, ref); j++)
1961 if (ref->refering_type == IPA_REF_VARPOOL)
1962 {
1963 varpool_node_set_iterator vsi;
1964
1965 vnode = ipa_ref_refering_varpool_node (ref);
1966 gcc_assert (vnode->finalized);
1967 if (!vnode->aux && flag_toplevel_reorder
1968 && partition_varpool_node_p (vnode))
1969 add_varpool_node_to_partition (partition, vnode);
1970 vsi = varpool_node_set_find (partition->varpool_set, vnode);
1971 if (!vsi_end_p (vsi)
1972 && vsi.index < last_visited_varpool_node)
1973 cost--;
1974 else
1975 cost++;
1976 }
1977 else
1978 {
1979 cgraph_node_set_iterator csi;
1980
1981 node = ipa_ref_refering_node (ref);
1982 gcc_assert (node->analyzed);
1983 csi = cgraph_node_set_find (partition->cgraph_set, node);
1984 if (!csi_end_p (csi)
1985 && csi.index < last_visited_cgraph_node)
1986 cost--;
1987 else
1988 cost++;
1989 }
1990 }
1991
1992 /* If the partition is large enough, start looking for smallest boundary cost. */
1993 if (partition->insns < partition_size * 3 / 4
1994 || best_cost == INT_MAX
1995 || ((!cost
1996 || (best_internal * (HOST_WIDE_INT) cost
1997 > (internal * (HOST_WIDE_INT)best_cost)))
1998 && partition->insns < partition_size * 5 / 4))
1999 {
2000 best_cost = cost;
2001 best_internal = internal;
2002 best_i = i;
2003 best_n_nodes = VEC_length (cgraph_node_ptr,
2004 partition->cgraph_set->nodes);
2005 best_n_varpool_nodes = VEC_length (varpool_node_ptr,
2006 partition->varpool_set->nodes);
2007 best_total_size = total_size;
2008 }
2009 if (cgraph_dump_file)
2010 fprintf (cgraph_dump_file, "Step %i: added %s/%i, size %i, cost %i/%i best %i/%i, step %i\n", i,
2011 cgraph_node_name (order[i]), order[i]->uid, partition->insns, cost, internal,
2012 best_cost, best_internal, best_i);
2013 /* Partition is too large, unwind into step when best cost was reached and
2014 start new partition. */
2015 if (partition->insns > 2 * partition_size)
2016 {
2017 if (best_i != i)
2018 {
2019 if (cgraph_dump_file)
2020 fprintf (cgraph_dump_file, "Unwinding %i insertions to step %i\n",
2021 i - best_i, best_i);
2022 undo_partition (partition, best_n_nodes, best_n_varpool_nodes);
2023 }
2024 i = best_i;
2025 /* When we are finished, avoid creating empty partition. */
2026 while (i < n_nodes - 1 && order[i + 1]->aux)
2027 i++;
2028 if (i == n_nodes - 1)
2029 break;
2030 partition = new_partition ("");
2031 last_visited_cgraph_node = 0;
2032 last_visited_varpool_node = 0;
2033 total_size = best_total_size;
2034 cost = 0;
2035
2036 if (cgraph_dump_file)
2037 fprintf (cgraph_dump_file, "New partition\n");
2038 best_n_nodes = 0;
2039 best_n_varpool_nodes = 0;
2040 best_cost = INT_MAX;
2041
2042 /* Since the size of partitions is just approximate, update the size after
2043 we finished current one. */
2044 if (npartitions < PARAM_VALUE (PARAM_LTO_PARTITIONS))
2045 partition_size = total_size
2046 / (PARAM_VALUE (PARAM_LTO_PARTITIONS) - npartitions);
2047 else
2048 partition_size = INT_MAX;
2049
2050 if (partition_size < PARAM_VALUE (MIN_PARTITION_SIZE))
2051 partition_size = PARAM_VALUE (MIN_PARTITION_SIZE);
2052 npartitions ++;
2053 }
2054 }
2055
2056 /* Varables that are not reachable from the code go into last partition. */
2057 if (flag_toplevel_reorder)
2058 {
2059 for (vnode = varpool_nodes; vnode; vnode = vnode->next)
2060 if (partition_varpool_node_p (vnode) && !vnode->aux)
2061 add_varpool_node_to_partition (partition, vnode);
2062 }
2063 else
2064 {
2065 while (varpool_pos < n_varpool_nodes)
2066 {
2067 if (!varpool_order[varpool_pos]->aux)
2068 add_varpool_node_to_partition (partition, varpool_order[varpool_pos]);
2069 varpool_pos++;
2070 }
2071 free (varpool_order);
2072 }
2073 free (order);
2074 }
2075
2076 /* Promote variable VNODE to be static. */
2077
2078 static bool
promote_var(struct varpool_node * vnode)2079 promote_var (struct varpool_node *vnode)
2080 {
2081 if (TREE_PUBLIC (vnode->decl) || DECL_EXTERNAL (vnode->decl))
2082 return false;
2083 gcc_assert (flag_wpa);
2084 TREE_PUBLIC (vnode->decl) = 1;
2085 DECL_VISIBILITY (vnode->decl) = VISIBILITY_HIDDEN;
2086 DECL_VISIBILITY_SPECIFIED (vnode->decl) = true;
2087 if (cgraph_dump_file)
2088 fprintf (cgraph_dump_file,
2089 "Promoting var as hidden: %s\n", varpool_node_name (vnode));
2090 return true;
2091 }
2092
2093 /* Promote function NODE to be static. */
2094
2095 static bool
promote_fn(struct cgraph_node * node)2096 promote_fn (struct cgraph_node *node)
2097 {
2098 gcc_assert (flag_wpa);
2099 if (TREE_PUBLIC (node->decl) || DECL_EXTERNAL (node->decl))
2100 return false;
2101 TREE_PUBLIC (node->decl) = 1;
2102 DECL_VISIBILITY (node->decl) = VISIBILITY_HIDDEN;
2103 DECL_VISIBILITY_SPECIFIED (node->decl) = true;
2104 if (cgraph_dump_file)
2105 fprintf (cgraph_dump_file,
2106 "Promoting function as hidden: %s/%i\n",
2107 cgraph_node_name (node), node->uid);
2108 return true;
2109 }
2110
2111 /* Find out all static decls that need to be promoted to global because
2112 of cross file sharing. This function must be run in the WPA mode after
2113 all inlinees are added. */
2114
2115 static void
lto_promote_cross_file_statics(void)2116 lto_promote_cross_file_statics (void)
2117 {
2118 struct varpool_node *vnode;
2119 unsigned i, n_sets;
2120 cgraph_node_set set;
2121 varpool_node_set vset;
2122 cgraph_node_set_iterator csi;
2123 varpool_node_set_iterator vsi;
2124 VEC(varpool_node_ptr, heap) *promoted_initializers = NULL;
2125 struct pointer_set_t *inserted = pointer_set_create ();
2126
2127 gcc_assert (flag_wpa);
2128
2129 n_sets = VEC_length (ltrans_partition, ltrans_partitions);
2130 for (i = 0; i < n_sets; i++)
2131 {
2132 ltrans_partition part
2133 = VEC_index (ltrans_partition, ltrans_partitions, i);
2134 set = part->cgraph_set;
2135 vset = part->varpool_set;
2136
2137 /* If node called or referred to from other partition, it needs to be
2138 globalized. */
2139 for (csi = csi_start (set); !csi_end_p (csi); csi_next (&csi))
2140 {
2141 struct cgraph_node *node = csi_node (csi);
2142 if (node->local.externally_visible)
2143 continue;
2144 if (node->global.inlined_to)
2145 continue;
2146 if ((!DECL_EXTERNAL (node->decl) && !DECL_COMDAT (node->decl))
2147 && (referenced_from_other_partition_p (&node->ref_list, set, vset)
2148 || reachable_from_other_partition_p (node, set)))
2149 promote_fn (node);
2150 }
2151 for (vsi = vsi_start (vset); !vsi_end_p (vsi); vsi_next (&vsi))
2152 {
2153 vnode = vsi_node (vsi);
2154 /* Constant pool references use internal labels and thus can not
2155 be made global. It is sensible to keep those ltrans local to
2156 allow better optimization. */
2157 if (!DECL_IN_CONSTANT_POOL (vnode->decl) && !DECL_COMDAT (vnode->decl)
2158 && !vnode->externally_visible && vnode->analyzed
2159 && referenced_from_other_partition_p (&vnode->ref_list,
2160 set, vset))
2161 promote_var (vnode);
2162 }
2163
2164 /* We export the initializer of a read-only var into each partition
2165 referencing the var. Folding might take declarations from the
2166 initializer and use them, so everything referenced from the
2167 initializer can be accessed from this partition after folding.
2168
2169 This means that we need to promote all variables and functions
2170 referenced from all initializers of read-only vars referenced
2171 from this partition that are not in this partition. This needs
2172 to be done recursively. */
2173 for (vnode = varpool_nodes; vnode; vnode = vnode->next)
2174 if (const_value_known_p (vnode->decl)
2175 && DECL_INITIAL (vnode->decl)
2176 && !varpool_node_in_set_p (vnode, vset)
2177 && referenced_from_this_partition_p (&vnode->ref_list, set, vset)
2178 && !pointer_set_insert (inserted, vnode))
2179 VEC_safe_push (varpool_node_ptr, heap, promoted_initializers, vnode);
2180
2181 while (!VEC_empty (varpool_node_ptr, promoted_initializers))
2182 {
2183 int i;
2184 struct ipa_ref *ref;
2185
2186 vnode = VEC_pop (varpool_node_ptr, promoted_initializers);
2187 for (i = 0;
2188 ipa_ref_list_reference_iterate (&vnode->ref_list, i, ref);
2189 i++)
2190 {
2191 if (ref->refered_type == IPA_REF_CGRAPH)
2192 {
2193 struct cgraph_node *n = ipa_ref_node (ref);
2194 gcc_assert (!n->global.inlined_to);
2195 if (!n->local.externally_visible
2196 && !cgraph_node_in_set_p (n, set))
2197 promote_fn (n);
2198 }
2199 else
2200 {
2201 struct varpool_node *v = ipa_ref_varpool_node (ref);
2202 if (varpool_node_in_set_p (v, vset))
2203 continue;
2204
2205 /* Constant pool references use internal labels and thus
2206 cannot be made global. It is sensible to keep those
2207 ltrans local to allow better optimization. */
2208 if (DECL_IN_CONSTANT_POOL (v->decl))
2209 {
2210 if (!pointer_set_insert (inserted, vnode))
2211 VEC_safe_push (varpool_node_ptr, heap,
2212 promoted_initializers, v);
2213 }
2214 else if (!v->externally_visible && v->analyzed)
2215 {
2216 if (promote_var (v)
2217 && DECL_INITIAL (v->decl)
2218 && const_value_known_p (v->decl)
2219 && !pointer_set_insert (inserted, vnode))
2220 VEC_safe_push (varpool_node_ptr, heap,
2221 promoted_initializers, v);
2222 }
2223 }
2224 }
2225 }
2226 }
2227 pointer_set_destroy (inserted);
2228 }
2229
2230 static lto_file *current_lto_file;
2231
2232 /* Helper for qsort; compare partitions and return one with smaller size.
2233 We sort from greatest to smallest so parallel build doesn't stale on the
2234 longest compilation being executed too late. */
2235
2236 static int
cmp_partitions_size(const void * a,const void * b)2237 cmp_partitions_size (const void *a, const void *b)
2238 {
2239 const struct ltrans_partition_def *pa
2240 = *(struct ltrans_partition_def *const *)a;
2241 const struct ltrans_partition_def *pb
2242 = *(struct ltrans_partition_def *const *)b;
2243 return pb->insns - pa->insns;
2244 }
2245
2246 /* Helper for qsort; compare partitions and return one with smaller order. */
2247
2248 static int
cmp_partitions_order(const void * a,const void * b)2249 cmp_partitions_order (const void *a, const void *b)
2250 {
2251 const struct ltrans_partition_def *pa
2252 = *(struct ltrans_partition_def *const *)a;
2253 const struct ltrans_partition_def *pb
2254 = *(struct ltrans_partition_def *const *)b;
2255 int ordera = -1, orderb = -1;
2256
2257 if (VEC_length (cgraph_node_ptr, pa->cgraph_set->nodes))
2258 ordera = VEC_index (cgraph_node_ptr, pa->cgraph_set->nodes, 0)->order;
2259 else if (VEC_length (varpool_node_ptr, pa->varpool_set->nodes))
2260 ordera = VEC_index (varpool_node_ptr, pa->varpool_set->nodes, 0)->order;
2261 if (VEC_length (cgraph_node_ptr, pb->cgraph_set->nodes))
2262 orderb = VEC_index (cgraph_node_ptr, pb->cgraph_set->nodes, 0)->order;
2263 else if (VEC_length (varpool_node_ptr, pb->varpool_set->nodes))
2264 orderb = VEC_index (varpool_node_ptr, pb->varpool_set->nodes, 0)->order;
2265 return orderb - ordera;
2266 }
2267
2268 /* Write all output files in WPA mode and the file with the list of
2269 LTRANS units. */
2270
2271 static void
lto_wpa_write_files(void)2272 lto_wpa_write_files (void)
2273 {
2274 unsigned i, n_sets;
2275 lto_file *file;
2276 cgraph_node_set set;
2277 varpool_node_set vset;
2278 ltrans_partition part;
2279 FILE *ltrans_output_list_stream;
2280 char *temp_filename;
2281 size_t blen;
2282
2283 /* Open the LTRANS output list. */
2284 if (!ltrans_output_list)
2285 fatal_error ("no LTRANS output list filename provided");
2286 ltrans_output_list_stream = fopen (ltrans_output_list, "w");
2287 if (ltrans_output_list_stream == NULL)
2288 fatal_error ("opening LTRANS output list %s: %m", ltrans_output_list);
2289
2290 timevar_push (TV_WHOPR_WPA);
2291
2292 FOR_EACH_VEC_ELT (ltrans_partition, ltrans_partitions, i, part)
2293 lto_stats.num_output_cgraph_nodes += VEC_length (cgraph_node_ptr,
2294 part->cgraph_set->nodes);
2295
2296 /* Find out statics that need to be promoted
2297 to globals with hidden visibility because they are accessed from multiple
2298 partitions. */
2299 lto_promote_cross_file_statics ();
2300
2301 timevar_pop (TV_WHOPR_WPA);
2302
2303 timevar_push (TV_WHOPR_WPA_IO);
2304
2305 /* Generate a prefix for the LTRANS unit files. */
2306 blen = strlen (ltrans_output_list);
2307 temp_filename = (char *) xmalloc (blen + sizeof ("2147483648.o"));
2308 strcpy (temp_filename, ltrans_output_list);
2309 if (blen > sizeof (".out")
2310 && strcmp (temp_filename + blen - sizeof (".out") + 1,
2311 ".out") == 0)
2312 temp_filename[blen - sizeof (".out") + 1] = '\0';
2313 blen = strlen (temp_filename);
2314
2315 n_sets = VEC_length (ltrans_partition, ltrans_partitions);
2316
2317 /* Sort partitions by size so small ones are compiled last.
2318 FIXME: Even when not reordering we may want to output one list for parallel make
2319 and other for final link command. */
2320 VEC_qsort (ltrans_partition, ltrans_partitions,
2321 flag_toplevel_reorder ? cmp_partitions_size : cmp_partitions_order);
2322 for (i = 0; i < n_sets; i++)
2323 {
2324 size_t len;
2325 ltrans_partition part = VEC_index (ltrans_partition, ltrans_partitions, i);
2326
2327 set = part->cgraph_set;
2328 vset = part->varpool_set;
2329
2330 /* Write all the nodes in SET. */
2331 sprintf (temp_filename + blen, "%u.o", i);
2332 file = lto_obj_file_open (temp_filename, true);
2333 if (!file)
2334 fatal_error ("lto_obj_file_open() failed");
2335
2336 if (!quiet_flag)
2337 fprintf (stderr, " %s (%s %i insns)", temp_filename, part->name, part->insns);
2338 if (cgraph_dump_file)
2339 {
2340 fprintf (cgraph_dump_file, "Writing partition %s to file %s, %i insns\n",
2341 part->name, temp_filename, part->insns);
2342 fprintf (cgraph_dump_file, "cgraph nodes:");
2343 dump_cgraph_node_set (cgraph_dump_file, set);
2344 fprintf (cgraph_dump_file, "varpool nodes:");
2345 dump_varpool_node_set (cgraph_dump_file, vset);
2346 }
2347 gcc_checking_assert (cgraph_node_set_nonempty_p (set)
2348 || varpool_node_set_nonempty_p (vset) || !i);
2349
2350 lto_set_current_out_file (file);
2351
2352 ipa_write_optimization_summaries (set, vset);
2353
2354 lto_set_current_out_file (NULL);
2355 lto_obj_file_close (file);
2356
2357 len = strlen (temp_filename);
2358 if (fwrite (temp_filename, 1, len, ltrans_output_list_stream) < len
2359 || fwrite ("\n", 1, 1, ltrans_output_list_stream) < 1)
2360 fatal_error ("writing to LTRANS output list %s: %m",
2361 ltrans_output_list);
2362 }
2363
2364 lto_stats.num_output_files += n_sets;
2365
2366 /* Close the LTRANS output list. */
2367 if (fclose (ltrans_output_list_stream))
2368 fatal_error ("closing LTRANS output list %s: %m", ltrans_output_list);
2369
2370 free_ltrans_partitions();
2371
2372 timevar_pop (TV_WHOPR_WPA_IO);
2373 }
2374
2375
2376 /* If TT is a variable or function decl replace it with its
2377 prevailing variant. */
2378 #define LTO_SET_PREVAIL(tt) \
2379 do {\
2380 if ((tt) && VAR_OR_FUNCTION_DECL_P (tt)) \
2381 tt = lto_symtab_prevailing_decl (tt); \
2382 } while (0)
2383
2384 /* Ensure that TT isn't a replacable var of function decl. */
2385 #define LTO_NO_PREVAIL(tt) \
2386 gcc_assert (!(tt) || !VAR_OR_FUNCTION_DECL_P (tt))
2387
2388 /* Given a tree T replace all fields referring to variables or functions
2389 with their prevailing variant. */
2390 static void
lto_fixup_prevailing_decls(tree t)2391 lto_fixup_prevailing_decls (tree t)
2392 {
2393 enum tree_code code = TREE_CODE (t);
2394 LTO_NO_PREVAIL (TREE_TYPE (t));
2395 if (CODE_CONTAINS_STRUCT (code, TS_COMMON))
2396 LTO_NO_PREVAIL (TREE_CHAIN (t));
2397 if (DECL_P (t))
2398 {
2399 LTO_NO_PREVAIL (DECL_NAME (t));
2400 LTO_SET_PREVAIL (DECL_CONTEXT (t));
2401 if (CODE_CONTAINS_STRUCT (code, TS_DECL_COMMON))
2402 {
2403 LTO_SET_PREVAIL (DECL_SIZE (t));
2404 LTO_SET_PREVAIL (DECL_SIZE_UNIT (t));
2405 LTO_SET_PREVAIL (DECL_INITIAL (t));
2406 LTO_NO_PREVAIL (DECL_ATTRIBUTES (t));
2407 LTO_SET_PREVAIL (DECL_ABSTRACT_ORIGIN (t));
2408 }
2409 if (CODE_CONTAINS_STRUCT (code, TS_DECL_WITH_VIS))
2410 {
2411 LTO_NO_PREVAIL (t->decl_with_vis.assembler_name);
2412 LTO_NO_PREVAIL (DECL_SECTION_NAME (t));
2413 }
2414 if (CODE_CONTAINS_STRUCT (code, TS_DECL_NON_COMMON))
2415 {
2416 LTO_NO_PREVAIL (DECL_ARGUMENT_FLD (t));
2417 LTO_NO_PREVAIL (DECL_RESULT_FLD (t));
2418 LTO_NO_PREVAIL (DECL_VINDEX (t));
2419 }
2420 if (CODE_CONTAINS_STRUCT (code, TS_FUNCTION_DECL))
2421 LTO_SET_PREVAIL (DECL_FUNCTION_PERSONALITY (t));
2422 if (CODE_CONTAINS_STRUCT (code, TS_FIELD_DECL))
2423 {
2424 LTO_NO_PREVAIL (DECL_FIELD_OFFSET (t));
2425 LTO_NO_PREVAIL (DECL_BIT_FIELD_TYPE (t));
2426 LTO_NO_PREVAIL (DECL_QUALIFIER (t));
2427 LTO_NO_PREVAIL (DECL_FIELD_BIT_OFFSET (t));
2428 LTO_NO_PREVAIL (DECL_FCONTEXT (t));
2429 }
2430 }
2431 else if (TYPE_P (t))
2432 {
2433 LTO_NO_PREVAIL (TYPE_CACHED_VALUES (t));
2434 LTO_SET_PREVAIL (TYPE_SIZE (t));
2435 LTO_SET_PREVAIL (TYPE_SIZE_UNIT (t));
2436 LTO_NO_PREVAIL (TYPE_ATTRIBUTES (t));
2437 LTO_NO_PREVAIL (TYPE_NAME (t));
2438
2439 LTO_SET_PREVAIL (TYPE_MINVAL (t));
2440 LTO_SET_PREVAIL (TYPE_MAXVAL (t));
2441 LTO_SET_PREVAIL (t->type_non_common.binfo);
2442
2443 LTO_SET_PREVAIL (TYPE_CONTEXT (t));
2444
2445 LTO_NO_PREVAIL (TYPE_CANONICAL (t));
2446 LTO_NO_PREVAIL (TYPE_MAIN_VARIANT (t));
2447 LTO_NO_PREVAIL (TYPE_NEXT_VARIANT (t));
2448 }
2449 else if (EXPR_P (t))
2450 {
2451 int i;
2452 LTO_NO_PREVAIL (t->exp.block);
2453 for (i = TREE_OPERAND_LENGTH (t) - 1; i >= 0; --i)
2454 LTO_SET_PREVAIL (TREE_OPERAND (t, i));
2455 }
2456 else
2457 {
2458 switch (code)
2459 {
2460 case TREE_LIST:
2461 LTO_SET_PREVAIL (TREE_VALUE (t));
2462 LTO_SET_PREVAIL (TREE_PURPOSE (t));
2463 break;
2464 default:
2465 gcc_unreachable ();
2466 }
2467 }
2468 }
2469 #undef LTO_SET_PREVAIL
2470 #undef LTO_NO_PREVAIL
2471
2472 /* Helper function of lto_fixup_decls. Walks the var and fn streams in STATE,
2473 replaces var and function decls with the corresponding prevailing def. */
2474
2475 static void
lto_fixup_state(struct lto_in_decl_state * state)2476 lto_fixup_state (struct lto_in_decl_state *state)
2477 {
2478 unsigned i, si;
2479 struct lto_tree_ref_table *table;
2480
2481 /* Although we only want to replace FUNCTION_DECLs and VAR_DECLs,
2482 we still need to walk from all DECLs to find the reachable
2483 FUNCTION_DECLs and VAR_DECLs. */
2484 for (si = 0; si < LTO_N_DECL_STREAMS; si++)
2485 {
2486 table = &state->streams[si];
2487 for (i = 0; i < table->size; i++)
2488 {
2489 tree *tp = table->trees + i;
2490 if (VAR_OR_FUNCTION_DECL_P (*tp))
2491 *tp = lto_symtab_prevailing_decl (*tp);
2492 }
2493 }
2494 }
2495
2496 /* A callback of htab_traverse. Just extracts a state from SLOT
2497 and calls lto_fixup_state. */
2498
2499 static int
lto_fixup_state_aux(void ** slot,void * aux ATTRIBUTE_UNUSED)2500 lto_fixup_state_aux (void **slot, void *aux ATTRIBUTE_UNUSED)
2501 {
2502 struct lto_in_decl_state *state = (struct lto_in_decl_state *) *slot;
2503 lto_fixup_state (state);
2504 return 1;
2505 }
2506
2507 /* Fix the decls from all FILES. Replaces each decl with the corresponding
2508 prevailing one. */
2509
2510 static void
lto_fixup_decls(struct lto_file_decl_data ** files)2511 lto_fixup_decls (struct lto_file_decl_data **files)
2512 {
2513 unsigned int i;
2514 htab_iterator hi;
2515 tree t;
2516
2517 FOR_EACH_HTAB_ELEMENT (tree_with_vars, t, tree, hi)
2518 lto_fixup_prevailing_decls (t);
2519
2520 for (i = 0; files[i]; i++)
2521 {
2522 struct lto_file_decl_data *file = files[i];
2523 struct lto_in_decl_state *state = file->global_decl_state;
2524 lto_fixup_state (state);
2525
2526 htab_traverse (file->function_decl_states, lto_fixup_state_aux, NULL);
2527 }
2528 }
2529
2530 static GTY((length ("lto_stats.num_input_files + 1"))) struct lto_file_decl_data **all_file_decl_data;
2531
2532 /* Turn file datas for sub files into a single array, so that they look
2533 like separate files for further passes. */
2534
2535 static void
lto_flatten_files(struct lto_file_decl_data ** orig,int count,int last_file_ix)2536 lto_flatten_files (struct lto_file_decl_data **orig, int count, int last_file_ix)
2537 {
2538 struct lto_file_decl_data *n, *next;
2539 int i, k;
2540
2541 lto_stats.num_input_files = count;
2542 all_file_decl_data
2543 = ggc_alloc_cleared_vec_lto_file_decl_data_ptr (count + 1);
2544 /* Set the hooks so that all of the ipa passes can read in their data. */
2545 lto_set_in_hooks (all_file_decl_data, get_section_data, free_section_data);
2546 for (i = 0, k = 0; i < last_file_ix; i++)
2547 {
2548 for (n = orig[i]; n != NULL; n = next)
2549 {
2550 all_file_decl_data[k++] = n;
2551 next = n->next;
2552 n->next = NULL;
2553 }
2554 }
2555 all_file_decl_data[k] = NULL;
2556 gcc_assert (k == count);
2557 }
2558
2559 /* Input file data before flattening (i.e. splitting them to subfiles to support
2560 incremental linking. */
2561 static int real_file_count;
2562 static GTY((length ("real_file_count + 1"))) struct lto_file_decl_data **real_file_decl_data;
2563
2564 /* Read all the symbols from the input files FNAMES. NFILES is the
2565 number of files requested in the command line. Instantiate a
2566 global call graph by aggregating all the sub-graphs found in each
2567 file. */
2568
2569 static void
read_cgraph_and_symbols(unsigned nfiles,const char ** fnames)2570 read_cgraph_and_symbols (unsigned nfiles, const char **fnames)
2571 {
2572 unsigned int i, last_file_ix;
2573 FILE *resolution;
2574 struct cgraph_node *node;
2575 int count = 0;
2576 struct lto_file_decl_data **decl_data;
2577
2578 init_cgraph ();
2579
2580 timevar_push (TV_IPA_LTO_DECL_IN);
2581
2582 real_file_decl_data
2583 = decl_data = ggc_alloc_cleared_vec_lto_file_decl_data_ptr (nfiles + 1);
2584 real_file_count = nfiles;
2585
2586 /* Read the resolution file. */
2587 resolution = NULL;
2588 if (resolution_file_name)
2589 {
2590 int t;
2591 unsigned num_objects;
2592
2593 resolution = fopen (resolution_file_name, "r");
2594 if (resolution == NULL)
2595 fatal_error ("could not open symbol resolution file: %m");
2596
2597 t = fscanf (resolution, "%u", &num_objects);
2598 gcc_assert (t == 1);
2599
2600 /* True, since the plugin splits the archives. */
2601 gcc_assert (num_objects == nfiles);
2602 }
2603
2604 tree_with_vars = htab_create_ggc (101, htab_hash_pointer, htab_eq_pointer,
2605 NULL);
2606
2607 if (!quiet_flag)
2608 fprintf (stderr, "Reading object files:");
2609
2610 /* Read all of the object files specified on the command line. */
2611 for (i = 0, last_file_ix = 0; i < nfiles; ++i)
2612 {
2613 struct lto_file_decl_data *file_data = NULL;
2614 if (!quiet_flag)
2615 {
2616 fprintf (stderr, " %s", fnames[i]);
2617 fflush (stderr);
2618 }
2619
2620 current_lto_file = lto_obj_file_open (fnames[i], false);
2621 if (!current_lto_file)
2622 break;
2623
2624 file_data = lto_file_read (current_lto_file, resolution, &count);
2625 if (!file_data)
2626 {
2627 lto_obj_file_close (current_lto_file);
2628 current_lto_file = NULL;
2629 break;
2630 }
2631
2632 decl_data[last_file_ix++] = file_data;
2633
2634 lto_obj_file_close (current_lto_file);
2635 current_lto_file = NULL;
2636 ggc_collect ();
2637 }
2638
2639 lto_flatten_files (decl_data, count, last_file_ix);
2640 lto_stats.num_input_files = count;
2641 ggc_free(decl_data);
2642 real_file_decl_data = NULL;
2643
2644 if (resolution_file_name)
2645 fclose (resolution);
2646
2647 /* Set the hooks so that all of the ipa passes can read in their data. */
2648 lto_set_in_hooks (all_file_decl_data, get_section_data, free_section_data);
2649
2650 timevar_pop (TV_IPA_LTO_DECL_IN);
2651
2652 if (!quiet_flag)
2653 fprintf (stderr, "\nReading the callgraph\n");
2654
2655 timevar_push (TV_IPA_LTO_CGRAPH_IO);
2656 /* Read the callgraph. */
2657 input_cgraph ();
2658 timevar_pop (TV_IPA_LTO_CGRAPH_IO);
2659
2660 if (!quiet_flag)
2661 fprintf (stderr, "Merging declarations\n");
2662
2663 timevar_push (TV_IPA_LTO_DECL_MERGE);
2664 /* Merge global decls. */
2665 lto_symtab_merge_decls ();
2666
2667 /* If there were errors during symbol merging bail out, we have no
2668 good way to recover here. */
2669 if (seen_error ())
2670 fatal_error ("errors during merging of translation units");
2671
2672 /* Fixup all decls and types and free the type hash tables. */
2673 lto_fixup_decls (all_file_decl_data);
2674 htab_delete (tree_with_vars);
2675 tree_with_vars = NULL;
2676 free_gimple_type_tables ();
2677 ggc_collect ();
2678
2679 timevar_pop (TV_IPA_LTO_DECL_MERGE);
2680 /* Each pass will set the appropriate timer. */
2681
2682 if (!quiet_flag)
2683 fprintf (stderr, "Reading summaries\n");
2684
2685 /* Read the IPA summary data. */
2686 if (flag_ltrans)
2687 ipa_read_optimization_summaries ();
2688 else
2689 ipa_read_summaries ();
2690
2691 /* Finally merge the cgraph according to the decl merging decisions. */
2692 timevar_push (TV_IPA_LTO_CGRAPH_MERGE);
2693 if (cgraph_dump_file)
2694 {
2695 fprintf (cgraph_dump_file, "Before merging:\n");
2696 dump_cgraph (cgraph_dump_file);
2697 dump_varpool (cgraph_dump_file);
2698 }
2699 lto_symtab_merge_cgraph_nodes ();
2700 ggc_collect ();
2701
2702 if (flag_ltrans)
2703 for (node = cgraph_nodes; node; node = node->next)
2704 {
2705 /* FIXME: ipa_transforms_to_apply holds list of passes that have optimization
2706 summaries computed and needs to apply changes. At the moment WHOPR only
2707 supports inlining, so we can push it here by hand. In future we need to stream
2708 this field into ltrans compilation. */
2709 if (node->analyzed)
2710 VEC_safe_push (ipa_opt_pass, heap,
2711 node->ipa_transforms_to_apply,
2712 (ipa_opt_pass)&pass_ipa_inline);
2713 }
2714 lto_symtab_free ();
2715
2716 timevar_pop (TV_IPA_LTO_CGRAPH_MERGE);
2717
2718 timevar_push (TV_IPA_LTO_DECL_INIT_IO);
2719
2720 /* FIXME lto. This loop needs to be changed to use the pass manager to
2721 call the ipa passes directly. */
2722 if (!seen_error ())
2723 for (i = 0; i < last_file_ix; i++)
2724 {
2725 struct lto_file_decl_data *file_data = all_file_decl_data [i];
2726 lto_materialize_constructors_and_inits (file_data);
2727 }
2728
2729 /* Indicate that the cgraph is built and ready. */
2730 cgraph_function_flags_ready = true;
2731
2732 timevar_pop (TV_IPA_LTO_DECL_INIT_IO);
2733 ggc_free (all_file_decl_data);
2734 all_file_decl_data = NULL;
2735 }
2736
2737
2738 /* Materialize all the bodies for all the nodes in the callgraph. */
2739
2740 static void
materialize_cgraph(void)2741 materialize_cgraph (void)
2742 {
2743 tree decl;
2744 struct cgraph_node *node;
2745 unsigned i;
2746 timevar_id_t lto_timer;
2747
2748 if (!quiet_flag)
2749 fprintf (stderr,
2750 flag_wpa ? "Materializing decls:" : "Reading function bodies:");
2751
2752
2753 /* Now that we have input the cgraph, we need to clear all of the aux
2754 nodes and read the functions if we are not running in WPA mode. */
2755 timevar_push (TV_IPA_LTO_GIMPLE_IN);
2756
2757 for (node = cgraph_nodes; node; node = node->next)
2758 {
2759 if (node->local.lto_file_data)
2760 {
2761 lto_materialize_function (node);
2762 lto_stats.num_input_cgraph_nodes++;
2763 }
2764 }
2765
2766 timevar_pop (TV_IPA_LTO_GIMPLE_IN);
2767
2768 /* Start the appropriate timer depending on the mode that we are
2769 operating in. */
2770 lto_timer = (flag_wpa) ? TV_WHOPR_WPA
2771 : (flag_ltrans) ? TV_WHOPR_LTRANS
2772 : TV_LTO;
2773 timevar_push (lto_timer);
2774
2775 current_function_decl = NULL;
2776 set_cfun (NULL);
2777
2778 /* Inform the middle end about the global variables we have seen. */
2779 FOR_EACH_VEC_ELT (tree, lto_global_var_decls, i, decl)
2780 rest_of_decl_compilation (decl, 1, 0);
2781
2782 if (!quiet_flag)
2783 fprintf (stderr, "\n");
2784
2785 timevar_pop (lto_timer);
2786 }
2787
2788
2789 /* Perform whole program analysis (WPA) on the callgraph and write out the
2790 optimization plan. */
2791
2792 static void
do_whole_program_analysis(void)2793 do_whole_program_analysis (void)
2794 {
2795 /* Note that since we are in WPA mode, materialize_cgraph will not
2796 actually read in all the function bodies. It only materializes
2797 the decls and cgraph nodes so that analysis can be performed. */
2798 materialize_cgraph ();
2799
2800 /* Reading in the cgraph uses different timers, start timing WPA now. */
2801 timevar_push (TV_WHOPR_WPA);
2802
2803 if (pre_ipa_mem_report)
2804 {
2805 fprintf (stderr, "Memory consumption before IPA\n");
2806 dump_memory_report (false);
2807 }
2808
2809 cgraph_function_flags_ready = true;
2810
2811 if (cgraph_dump_file)
2812 {
2813 dump_cgraph (cgraph_dump_file);
2814 dump_varpool (cgraph_dump_file);
2815 }
2816 bitmap_obstack_initialize (NULL);
2817 cgraph_state = CGRAPH_STATE_IPA_SSA;
2818
2819 execute_ipa_pass_list (all_regular_ipa_passes);
2820
2821 if (cgraph_dump_file)
2822 {
2823 fprintf (cgraph_dump_file, "Optimized ");
2824 dump_cgraph (cgraph_dump_file);
2825 dump_varpool (cgraph_dump_file);
2826 }
2827 verify_cgraph ();
2828 bitmap_obstack_release (NULL);
2829
2830 /* We are about to launch the final LTRANS phase, stop the WPA timer. */
2831 timevar_pop (TV_WHOPR_WPA);
2832
2833 if (flag_lto_partition_1to1)
2834 lto_1_to_1_map ();
2835 else
2836 lto_balanced_map ();
2837
2838 if (!quiet_flag)
2839 {
2840 fprintf (stderr, "\nStreaming out");
2841 fflush (stderr);
2842 }
2843 lto_wpa_write_files ();
2844 ggc_collect ();
2845 if (!quiet_flag)
2846 fprintf (stderr, "\n");
2847
2848 if (post_ipa_mem_report)
2849 {
2850 fprintf (stderr, "Memory consumption after IPA\n");
2851 dump_memory_report (false);
2852 }
2853
2854 /* Show the LTO report before launching LTRANS. */
2855 if (flag_lto_report)
2856 print_lto_report ();
2857 }
2858
2859
2860 static GTY(()) tree lto_eh_personality_decl;
2861
2862 /* Return the LTO personality function decl. */
2863
2864 tree
lto_eh_personality(void)2865 lto_eh_personality (void)
2866 {
2867 if (!lto_eh_personality_decl)
2868 {
2869 /* Use the first personality DECL for our personality if we don't
2870 support multiple ones. This ensures that we don't artificially
2871 create the need for them in a single-language program. */
2872 if (first_personality_decl && !dwarf2out_do_cfi_asm ())
2873 lto_eh_personality_decl = first_personality_decl;
2874 else
2875 lto_eh_personality_decl = lhd_gcc_personality ();
2876 }
2877
2878 return lto_eh_personality_decl;
2879 }
2880
2881 /* Set the process name based on the LTO mode. */
2882
2883 static void
lto_process_name(void)2884 lto_process_name (void)
2885 {
2886 if (flag_lto)
2887 setproctitle ("lto1-lto");
2888 if (flag_wpa)
2889 setproctitle ("lto1-wpa");
2890 if (flag_ltrans)
2891 setproctitle ("lto1-ltrans");
2892 }
2893
2894
2895 /* Initialize the LTO front end. */
2896
2897 static void
lto_init(void)2898 lto_init (void)
2899 {
2900 lto_process_name ();
2901 lto_streamer_hooks_init ();
2902 lto_reader_init ();
2903 lto_set_in_hooks (NULL, get_section_data, free_section_data);
2904 memset (<o_stats, 0, sizeof (lto_stats));
2905 bitmap_obstack_initialize (NULL);
2906 gimple_register_cfg_hooks ();
2907 }
2908
2909
2910 /* Main entry point for the GIMPLE front end. This front end has
2911 three main personalities:
2912
2913 - LTO (-flto). All the object files on the command line are
2914 loaded in memory and processed as a single translation unit.
2915 This is the traditional link-time optimization behavior.
2916
2917 - WPA (-fwpa). Only the callgraph and summary information for
2918 files in the command file are loaded. A single callgraph
2919 (without function bodies) is instantiated for the whole set of
2920 files. IPA passes are only allowed to analyze the call graph
2921 and make transformation decisions. The callgraph is
2922 partitioned, each partition is written to a new object file
2923 together with the transformation decisions.
2924
2925 - LTRANS (-fltrans). Similar to -flto but it prevents the IPA
2926 summary files from running again. Since WPA computed summary
2927 information and decided what transformations to apply, LTRANS
2928 simply applies them. */
2929
2930 void
lto_main(void)2931 lto_main (void)
2932 {
2933 /* Initialize the LTO front end. */
2934 lto_init ();
2935
2936 /* Read all the symbols and call graph from all the files in the
2937 command line. */
2938 read_cgraph_and_symbols (num_in_fnames, in_fnames);
2939
2940 if (!seen_error ())
2941 {
2942 /* If WPA is enabled analyze the whole call graph and create an
2943 optimization plan. Otherwise, read in all the function
2944 bodies and continue with optimization. */
2945 if (flag_wpa)
2946 do_whole_program_analysis ();
2947 else
2948 {
2949 materialize_cgraph ();
2950
2951 /* Let the middle end know that we have read and merged all of
2952 the input files. */
2953 cgraph_optimize ();
2954
2955 /* FIXME lto, if the processes spawned by WPA fail, we miss
2956 the chance to print WPA's report, so WPA will call
2957 print_lto_report before launching LTRANS. If LTRANS was
2958 launched directly by the driver we would not need to do
2959 this. */
2960 if (flag_lto_report)
2961 print_lto_report ();
2962 }
2963 }
2964 }
2965
2966 #include "gt-lto-lto.h"
2967