Enable dumping of alias graphs.
[official-gcc/Ramakrishna.git] / gcc / varasm.c
blobd7f861195ff1c3807a7d90cb1a9a569e67e500c7
1 /* Output variables, constants and external declarations, for GNU compiler.
2 Copyright (C) 1987, 1988, 1989, 1992, 1993, 1994, 1995, 1996, 1997,
3 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009
4 Free Software Foundation, Inc.
6 This file is part of GCC.
8 GCC is free software; you can redistribute it and/or modify it under
9 the terms of the GNU General Public License as published by the Free
10 Software Foundation; either version 3, or (at your option) any later
11 version.
13 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
14 WARRANTY; without even the implied warranty of MERCHANTABILITY or
15 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
16 for more details.
18 You should have received a copy of the GNU General Public License
19 along with GCC; see the file COPYING3. If not see
20 <http://www.gnu.org/licenses/>. */
23 /* This file handles generation of all the assembler code
24 *except* the instructions of a function.
25 This includes declarations of variables and their initial values.
27 We also output the assembler code for constants stored in memory
28 and are responsible for combining constants with the same value. */
30 #include "config.h"
31 #include "system.h"
32 #include "coretypes.h"
33 #include "tm.h"
34 #include "rtl.h"
35 #include "tree.h"
36 #include "flags.h"
37 #include "function.h"
38 #include "expr.h"
39 #include "hard-reg-set.h"
40 #include "regs.h"
41 #include "real.h"
42 #include "output.h"
43 #include "toplev.h"
44 #include "hashtab.h"
45 #include "ggc.h"
46 #include "langhooks.h"
47 #include "tm_p.h"
48 #include "debug.h"
49 #include "target.h"
50 #include "targhooks.h"
51 #include "tree-mudflap.h"
52 #include "cgraph.h"
53 #include "cfglayout.h"
54 #include "basic-block.h"
55 #include "tree-iterator.h"
57 #ifdef XCOFF_DEBUGGING_INFO
58 #include "xcoffout.h" /* Needed for external data
59 declarations for e.g. AIX 4.x. */
60 #endif
62 /* The (assembler) name of the first globally-visible object output. */
63 extern GTY(()) const char *first_global_object_name;
64 extern GTY(()) const char *weak_global_object_name;
66 const char *first_global_object_name;
67 const char *weak_global_object_name;
69 struct addr_const;
70 struct constant_descriptor_rtx;
71 struct rtx_constant_pool;
73 #define n_deferred_constants (crtl->varasm.deferred_constants)
75 /* Number for making the label on the next
76 constant that is stored in memory. */
78 static GTY(()) int const_labelno;
80 /* Carry information from ASM_DECLARE_OBJECT_NAME
81 to ASM_FINISH_DECLARE_OBJECT. */
83 int size_directive_output;
85 /* The last decl for which assemble_variable was called,
86 if it did ASM_DECLARE_OBJECT_NAME.
87 If the last call to assemble_variable didn't do that,
88 this holds 0. */
90 tree last_assemble_variable_decl;
92 /* The following global variable indicates if the first basic block
93 in a function belongs to the cold partition or not. */
95 bool first_function_block_is_cold;
97 /* We give all constants their own alias set. Perhaps redundant with
98 MEM_READONLY_P, but pre-dates it. */
100 static alias_set_type const_alias_set;
102 static const char *strip_reg_name (const char *);
103 static int contains_pointers_p (tree);
104 #ifdef ASM_OUTPUT_EXTERNAL
105 static bool incorporeal_function_p (tree);
106 #endif
107 static void decode_addr_const (tree, struct addr_const *);
108 static hashval_t const_desc_hash (const void *);
109 static int const_desc_eq (const void *, const void *);
110 static hashval_t const_hash_1 (const tree);
111 static int compare_constant (const tree, const tree);
112 static tree copy_constant (tree);
113 static void output_constant_def_contents (rtx);
114 static void output_addressed_constants (tree);
115 static unsigned HOST_WIDE_INT array_size_for_constructor (tree);
116 static unsigned min_align (unsigned, unsigned);
117 static void globalize_decl (tree);
118 #ifdef BSS_SECTION_ASM_OP
119 #ifdef ASM_OUTPUT_BSS
120 static void asm_output_bss (FILE *, tree, const char *,
121 unsigned HOST_WIDE_INT, unsigned HOST_WIDE_INT);
122 #endif
123 #ifdef ASM_OUTPUT_ALIGNED_BSS
124 static void asm_output_aligned_bss (FILE *, tree, const char *,
125 unsigned HOST_WIDE_INT, int)
126 ATTRIBUTE_UNUSED;
127 #endif
128 #endif /* BSS_SECTION_ASM_OP */
129 static void mark_weak (tree);
130 static void output_constant_pool (const char *, tree);
132 /* Well-known sections, each one associated with some sort of *_ASM_OP. */
133 section *text_section;
134 section *data_section;
135 section *readonly_data_section;
136 section *sdata_section;
137 section *ctors_section;
138 section *dtors_section;
139 section *bss_section;
140 section *sbss_section;
142 /* Various forms of common section. All are guaranteed to be nonnull. */
143 section *tls_comm_section;
144 section *comm_section;
145 section *lcomm_section;
147 /* A SECTION_NOSWITCH section used for declaring global BSS variables.
148 May be null. */
149 section *bss_noswitch_section;
151 /* The section that holds the main exception table, when known. The section
152 is set either by the target's init_sections hook or by the first call to
153 switch_to_exception_section. */
154 section *exception_section;
156 /* The section that holds the DWARF2 frame unwind information, when known.
157 The section is set either by the target's init_sections hook or by the
158 first call to switch_to_eh_frame_section. */
159 section *eh_frame_section;
161 /* asm_out_file's current section. This is NULL if no section has yet
162 been selected or if we lose track of what the current section is. */
163 section *in_section;
165 /* True if code for the current function is currently being directed
166 at the cold section. */
167 bool in_cold_section_p;
169 /* A linked list of all the unnamed sections. */
170 static GTY(()) section *unnamed_sections;
172 /* Return a nonzero value if DECL has a section attribute. */
173 #ifndef IN_NAMED_SECTION
174 #define IN_NAMED_SECTION(DECL) \
175 ((TREE_CODE (DECL) == FUNCTION_DECL || TREE_CODE (DECL) == VAR_DECL) \
176 && DECL_SECTION_NAME (DECL) != NULL_TREE)
177 #endif
179 /* Hash table of named sections. */
180 static GTY((param_is (section))) htab_t section_htab;
182 /* A table of object_blocks, indexed by section. */
183 static GTY((param_is (struct object_block))) htab_t object_block_htab;
185 /* The next number to use for internal anchor labels. */
186 static GTY(()) int anchor_labelno;
188 /* A pool of constants that can be shared between functions. */
189 static GTY(()) struct rtx_constant_pool *shared_constant_pool;
191 /* TLS emulation. */
193 static GTY ((if_marked ("tree_map_marked_p"), param_is (struct tree_map)))
194 htab_t emutls_htab;
195 static GTY (()) tree emutls_object_type;
196 /* Emulated TLS objects have the TLS model TLS_MODEL_EMULATED. This
197 macro can be used on them to distinguish the control variable from
198 the initialization template. */
199 #define DECL_EMUTLS_VAR_P(D) (TREE_TYPE (D) == emutls_object_type)
201 #if !defined (NO_DOT_IN_LABEL)
202 # define EMUTLS_SEPARATOR "."
203 #elif !defined (NO_DOLLAR_IN_LABEL)
204 # define EMUTLS_SEPARATOR "$"
205 #else
206 # define EMUTLS_SEPARATOR "_"
207 #endif
209 /* Create an IDENTIFIER_NODE by prefixing PREFIX to the
210 IDENTIFIER_NODE NAME's name. */
212 static tree
213 prefix_name (const char *prefix, tree name)
215 unsigned plen = strlen (prefix);
216 unsigned nlen = strlen (IDENTIFIER_POINTER (name));
217 char *toname = (char *) alloca (plen + nlen + 1);
219 memcpy (toname, prefix, plen);
220 memcpy (toname + plen, IDENTIFIER_POINTER (name), nlen + 1);
222 return get_identifier (toname);
225 /* Create an identifier for the struct __emutls_object, given an identifier
226 of the DECL_ASSEMBLY_NAME of the original object. */
228 static tree
229 get_emutls_object_name (tree name)
231 const char *prefix = (targetm.emutls.var_prefix
232 ? targetm.emutls.var_prefix
233 : "__emutls_v" EMUTLS_SEPARATOR);
234 return prefix_name (prefix, name);
237 tree
238 default_emutls_var_fields (tree type, tree *name ATTRIBUTE_UNUSED)
240 tree word_type_node, field, next_field;
242 field = build_decl (UNKNOWN_LOCATION,
243 FIELD_DECL, get_identifier ("__templ"), ptr_type_node);
244 DECL_CONTEXT (field) = type;
245 next_field = field;
247 field = build_decl (UNKNOWN_LOCATION,
248 FIELD_DECL, get_identifier ("__offset"),
249 ptr_type_node);
250 DECL_CONTEXT (field) = type;
251 TREE_CHAIN (field) = next_field;
252 next_field = field;
254 word_type_node = lang_hooks.types.type_for_mode (word_mode, 1);
255 field = build_decl (UNKNOWN_LOCATION,
256 FIELD_DECL, get_identifier ("__align"),
257 word_type_node);
258 DECL_CONTEXT (field) = type;
259 TREE_CHAIN (field) = next_field;
260 next_field = field;
262 field = build_decl (UNKNOWN_LOCATION,
263 FIELD_DECL, get_identifier ("__size"), word_type_node);
264 DECL_CONTEXT (field) = type;
265 TREE_CHAIN (field) = next_field;
267 return field;
270 /* Create the structure for struct __emutls_object. This should match the
271 structure at the top of emutls.c, modulo the union there. */
273 static tree
274 get_emutls_object_type (void)
276 tree type, type_name, field;
278 type = emutls_object_type;
279 if (type)
280 return type;
282 emutls_object_type = type = lang_hooks.types.make_type (RECORD_TYPE);
283 type_name = NULL;
284 field = targetm.emutls.var_fields (type, &type_name);
285 if (!type_name)
286 type_name = get_identifier ("__emutls_object");
287 type_name = build_decl (UNKNOWN_LOCATION,
288 TYPE_DECL, type_name, type);
289 TYPE_NAME (type) = type_name;
290 TYPE_FIELDS (type) = field;
291 layout_type (type);
293 return type;
296 /* Create a read-only variable like DECL, with the same DECL_INITIAL.
297 This will be used for initializing the emulated tls data area. */
299 static tree
300 get_emutls_init_templ_addr (tree decl)
302 tree name, to;
304 if (targetm.emutls.register_common && !DECL_INITIAL (decl)
305 && !DECL_SECTION_NAME (decl))
306 return null_pointer_node;
308 name = DECL_ASSEMBLER_NAME (decl);
309 if (!targetm.emutls.tmpl_prefix || targetm.emutls.tmpl_prefix[0])
311 const char *prefix = (targetm.emutls.tmpl_prefix
312 ? targetm.emutls.tmpl_prefix
313 : "__emutls_t" EMUTLS_SEPARATOR);
314 name = prefix_name (prefix, name);
317 to = build_decl (DECL_SOURCE_LOCATION (decl),
318 VAR_DECL, name, TREE_TYPE (decl));
319 SET_DECL_ASSEMBLER_NAME (to, DECL_NAME (to));
320 DECL_TLS_MODEL (to) = TLS_MODEL_EMULATED;
321 DECL_ARTIFICIAL (to) = 1;
322 TREE_USED (to) = TREE_USED (decl);
323 TREE_READONLY (to) = 1;
324 DECL_IGNORED_P (to) = 1;
325 DECL_CONTEXT (to) = DECL_CONTEXT (decl);
326 DECL_SECTION_NAME (to) = DECL_SECTION_NAME (decl);
328 DECL_WEAK (to) = DECL_WEAK (decl);
329 if (DECL_ONE_ONLY (decl))
331 make_decl_one_only (to, DECL_ASSEMBLER_NAME (to));
332 TREE_STATIC (to) = TREE_STATIC (decl);
333 TREE_PUBLIC (to) = TREE_PUBLIC (decl);
334 DECL_VISIBILITY (to) = DECL_VISIBILITY (decl);
336 else
337 TREE_STATIC (to) = 1;
339 DECL_INITIAL (to) = DECL_INITIAL (decl);
340 DECL_INITIAL (decl) = NULL;
342 varpool_finalize_decl (to);
343 return build_fold_addr_expr (to);
346 /* When emulating tls, we use a control structure for use by the runtime.
347 Create and return this structure. */
349 tree
350 emutls_decl (tree decl)
352 tree name, to;
353 struct tree_map *h, in;
354 void **loc;
356 if (targetm.have_tls || decl == NULL || decl == error_mark_node
357 || TREE_CODE (decl) != VAR_DECL || ! DECL_THREAD_LOCAL_P (decl))
358 return decl;
360 /* Look up the object in the hash; return the control structure if
361 it has already been created. */
362 if (! emutls_htab)
363 emutls_htab = htab_create_ggc (512, tree_map_hash, tree_map_eq, 0);
365 name = DECL_ASSEMBLER_NAME (decl);
367 /* Note that we use the hash of the decl's name, rather than a hash
368 of the decl's pointer. In emutls_finish we iterate through the
369 hash table, and we want this traversal to be predictable. */
370 in.hash = htab_hash_string (IDENTIFIER_POINTER (name));
371 in.base.from = decl;
372 loc = htab_find_slot_with_hash (emutls_htab, &in, in.hash, INSERT);
373 h = (struct tree_map *) *loc;
374 if (h != NULL)
375 to = h->to;
376 else
378 to = build_decl (DECL_SOURCE_LOCATION (decl),
379 VAR_DECL, get_emutls_object_name (name),
380 get_emutls_object_type ());
382 h = GGC_NEW (struct tree_map);
383 h->hash = in.hash;
384 h->base.from = decl;
385 h->to = to;
386 *(struct tree_map **) loc = h;
388 DECL_TLS_MODEL (to) = TLS_MODEL_EMULATED;
389 DECL_ARTIFICIAL (to) = 1;
390 DECL_IGNORED_P (to) = 1;
391 TREE_READONLY (to) = 0;
392 SET_DECL_ASSEMBLER_NAME (to, DECL_NAME (to));
393 if (DECL_ONE_ONLY (decl))
394 make_decl_one_only (to, DECL_ASSEMBLER_NAME (to));
395 DECL_CONTEXT (to) = DECL_CONTEXT (decl);
396 if (targetm.emutls.var_align_fixed)
397 /* If we're not allowed to change the proxy object's
398 alignment, pretend it's been set by the user. */
399 DECL_USER_ALIGN (to) = 1;
402 /* Note that these fields may need to be updated from time to time from
403 the original decl. Consider:
404 extern __thread int i;
405 int foo() { return i; }
406 __thread int i = 1;
407 in which I goes from external to locally defined and initialized. */
409 TREE_STATIC (to) = TREE_STATIC (decl);
410 TREE_USED (to) = TREE_USED (decl);
411 TREE_PUBLIC (to) = TREE_PUBLIC (decl);
412 DECL_EXTERNAL (to) = DECL_EXTERNAL (decl);
413 DECL_COMMON (to) = DECL_COMMON (decl);
414 DECL_WEAK (to) = DECL_WEAK (decl);
415 DECL_VISIBILITY (to) = DECL_VISIBILITY (decl);
417 return to;
420 static int
421 emutls_common_1 (void **loc, void *xstmts)
423 struct tree_map *h = *(struct tree_map **) loc;
424 tree args, x, *pstmts = (tree *) xstmts;
425 tree word_type_node;
427 if (! DECL_COMMON (h->base.from)
428 || (DECL_INITIAL (h->base.from)
429 && DECL_INITIAL (h->base.from) != error_mark_node))
430 return 1;
432 word_type_node = lang_hooks.types.type_for_mode (word_mode, 1);
434 /* The idea was to call get_emutls_init_templ_addr here, but if we
435 do this and there is an initializer, -fanchor_section loses,
436 because it would be too late to ensure the template is
437 output. */
438 x = null_pointer_node;
439 args = tree_cons (NULL, x, NULL);
440 x = build_int_cst (word_type_node, DECL_ALIGN_UNIT (h->base.from));
441 args = tree_cons (NULL, x, args);
442 x = fold_convert (word_type_node, DECL_SIZE_UNIT (h->base.from));
443 args = tree_cons (NULL, x, args);
444 x = build_fold_addr_expr (h->to);
445 args = tree_cons (NULL, x, args);
447 x = built_in_decls[BUILT_IN_EMUTLS_REGISTER_COMMON];
448 x = build_function_call_expr (UNKNOWN_LOCATION, x, args);
450 append_to_statement_list (x, pstmts);
451 return 1;
454 void
455 emutls_finish (void)
457 if (targetm.emutls.register_common)
459 tree body = NULL_TREE;
461 if (emutls_htab == NULL)
462 return;
464 htab_traverse_noresize (emutls_htab, emutls_common_1, &body);
465 if (body == NULL_TREE)
466 return;
468 cgraph_build_static_cdtor ('I', body, DEFAULT_INIT_PRIORITY);
472 /* Helper routines for maintaining section_htab. */
474 static int
475 section_entry_eq (const void *p1, const void *p2)
477 const section *old = (const section *) p1;
478 const char *new_name = (const char *) p2;
480 return strcmp (old->named.name, new_name) == 0;
483 static hashval_t
484 section_entry_hash (const void *p)
486 const section *old = (const section *) p;
487 return htab_hash_string (old->named.name);
490 /* Return a hash value for section SECT. */
492 static hashval_t
493 hash_section (section *sect)
495 if (sect->common.flags & SECTION_NAMED)
496 return htab_hash_string (sect->named.name);
497 return sect->common.flags;
500 /* Helper routines for maintaining object_block_htab. */
502 static int
503 object_block_entry_eq (const void *p1, const void *p2)
505 const struct object_block *old = (const struct object_block *) p1;
506 const section *new_section = (const section *) p2;
508 return old->sect == new_section;
511 static hashval_t
512 object_block_entry_hash (const void *p)
514 const struct object_block *old = (const struct object_block *) p;
515 return hash_section (old->sect);
518 /* Return a new unnamed section with the given fields. */
520 section *
521 get_unnamed_section (unsigned int flags, void (*callback) (const void *),
522 const void *data)
524 section *sect;
526 sect = GGC_NEW (section);
527 sect->unnamed.common.flags = flags | SECTION_UNNAMED;
528 sect->unnamed.callback = callback;
529 sect->unnamed.data = data;
530 sect->unnamed.next = unnamed_sections;
532 unnamed_sections = sect;
533 return sect;
536 /* Return a SECTION_NOSWITCH section with the given fields. */
538 static section *
539 get_noswitch_section (unsigned int flags, noswitch_section_callback callback)
541 section *sect;
543 sect = GGC_NEW (section);
544 sect->noswitch.common.flags = flags | SECTION_NOSWITCH;
545 sect->noswitch.callback = callback;
547 return sect;
550 /* Return the named section structure associated with NAME. Create
551 a new section with the given fields if no such structure exists. */
553 section *
554 get_section (const char *name, unsigned int flags, tree decl)
556 section *sect, **slot;
558 slot = (section **)
559 htab_find_slot_with_hash (section_htab, name,
560 htab_hash_string (name), INSERT);
561 flags |= SECTION_NAMED;
562 if (*slot == NULL)
564 sect = GGC_NEW (section);
565 sect->named.common.flags = flags;
566 sect->named.name = ggc_strdup (name);
567 sect->named.decl = decl;
568 *slot = sect;
570 else
572 sect = *slot;
573 if ((sect->common.flags & ~SECTION_DECLARED) != flags
574 && ((sect->common.flags | flags) & SECTION_OVERRIDE) == 0)
576 /* Sanity check user variables for flag changes. */
577 if (decl == 0)
578 decl = sect->named.decl;
579 gcc_assert (decl);
580 error ("%+D causes a section type conflict", decl);
583 return sect;
586 /* Return true if the current compilation mode benefits from having
587 objects grouped into blocks. */
589 static bool
590 use_object_blocks_p (void)
592 return flag_section_anchors;
595 /* Return the object_block structure for section SECT. Create a new
596 structure if we haven't created one already. Return null if SECT
597 itself is null. */
599 static struct object_block *
600 get_block_for_section (section *sect)
602 struct object_block *block;
603 void **slot;
605 if (sect == NULL)
606 return NULL;
608 slot = htab_find_slot_with_hash (object_block_htab, sect,
609 hash_section (sect), INSERT);
610 block = (struct object_block *) *slot;
611 if (block == NULL)
613 block = (struct object_block *)
614 ggc_alloc_cleared (sizeof (struct object_block));
615 block->sect = sect;
616 *slot = block;
618 return block;
621 /* Create a symbol with label LABEL and place it at byte offset
622 OFFSET in BLOCK. OFFSET can be negative if the symbol's offset
623 is not yet known. LABEL must be a garbage-collected string. */
625 static rtx
626 create_block_symbol (const char *label, struct object_block *block,
627 HOST_WIDE_INT offset)
629 rtx symbol;
630 unsigned int size;
632 /* Create the extended SYMBOL_REF. */
633 size = RTX_HDR_SIZE + sizeof (struct block_symbol);
634 symbol = (rtx) ggc_alloc_zone (size, &rtl_zone);
636 /* Initialize the normal SYMBOL_REF fields. */
637 memset (symbol, 0, size);
638 PUT_CODE (symbol, SYMBOL_REF);
639 PUT_MODE (symbol, Pmode);
640 XSTR (symbol, 0) = label;
641 SYMBOL_REF_FLAGS (symbol) = SYMBOL_FLAG_HAS_BLOCK_INFO;
643 /* Initialize the block_symbol stuff. */
644 SYMBOL_REF_BLOCK (symbol) = block;
645 SYMBOL_REF_BLOCK_OFFSET (symbol) = offset;
647 return symbol;
650 static void
651 initialize_cold_section_name (void)
653 const char *stripped_name;
654 char *name, *buffer;
655 tree dsn;
657 gcc_assert (cfun && current_function_decl);
658 if (crtl->subsections.unlikely_text_section_name)
659 return;
661 dsn = DECL_SECTION_NAME (current_function_decl);
662 if (flag_function_sections && dsn)
664 name = (char *) alloca (TREE_STRING_LENGTH (dsn) + 1);
665 memcpy (name, TREE_STRING_POINTER (dsn), TREE_STRING_LENGTH (dsn) + 1);
667 stripped_name = targetm.strip_name_encoding (name);
669 buffer = ACONCAT ((stripped_name, "_unlikely", NULL));
670 crtl->subsections.unlikely_text_section_name = ggc_strdup (buffer);
672 else
673 crtl->subsections.unlikely_text_section_name = UNLIKELY_EXECUTED_TEXT_SECTION_NAME;
676 /* Tell assembler to switch to unlikely-to-be-executed text section. */
678 section *
679 unlikely_text_section (void)
681 if (cfun)
683 if (!crtl->subsections.unlikely_text_section_name)
684 initialize_cold_section_name ();
686 return get_named_section (NULL, crtl->subsections.unlikely_text_section_name, 0);
688 else
689 return get_named_section (NULL, UNLIKELY_EXECUTED_TEXT_SECTION_NAME, 0);
692 /* When called within a function context, return true if the function
693 has been assigned a cold text section and if SECT is that section.
694 When called outside a function context, return true if SECT is the
695 default cold section. */
697 bool
698 unlikely_text_section_p (section *sect)
700 const char *name;
702 if (cfun)
703 name = crtl->subsections.unlikely_text_section_name;
704 else
705 name = UNLIKELY_EXECUTED_TEXT_SECTION_NAME;
707 return (name
708 && sect
709 && SECTION_STYLE (sect) == SECTION_NAMED
710 && strcmp (name, sect->named.name) == 0);
713 /* Return a section with a particular name and with whatever SECTION_*
714 flags section_type_flags deems appropriate. The name of the section
715 is taken from NAME if nonnull, otherwise it is taken from DECL's
716 DECL_SECTION_NAME. DECL is the decl associated with the section
717 (see the section comment for details) and RELOC is as for
718 section_type_flags. */
720 section *
721 get_named_section (tree decl, const char *name, int reloc)
723 unsigned int flags;
725 gcc_assert (!decl || DECL_P (decl));
726 if (name == NULL)
727 name = TREE_STRING_POINTER (DECL_SECTION_NAME (decl));
729 flags = targetm.section_type_flags (decl, name, reloc);
731 return get_section (name, flags, decl);
734 /* If required, set DECL_SECTION_NAME to a unique name. */
736 void
737 resolve_unique_section (tree decl, int reloc ATTRIBUTE_UNUSED,
738 int flag_function_or_data_sections)
740 if (DECL_SECTION_NAME (decl) == NULL_TREE
741 && targetm.have_named_sections
742 && (flag_function_or_data_sections
743 || DECL_ONE_ONLY (decl)))
744 targetm.asm_out.unique_section (decl, reloc);
747 #ifdef BSS_SECTION_ASM_OP
749 #ifdef ASM_OUTPUT_BSS
751 /* Utility function for ASM_OUTPUT_BSS for targets to use if
752 they don't support alignments in .bss.
753 ??? It is believed that this function will work in most cases so such
754 support is localized here. */
756 static void
757 asm_output_bss (FILE *file, tree decl ATTRIBUTE_UNUSED,
758 const char *name,
759 unsigned HOST_WIDE_INT size ATTRIBUTE_UNUSED,
760 unsigned HOST_WIDE_INT rounded)
762 gcc_assert (strcmp (XSTR (XEXP (DECL_RTL (decl), 0), 0), name) == 0);
763 targetm.asm_out.globalize_decl_name (file, decl);
764 switch_to_section (bss_section);
765 #ifdef ASM_DECLARE_OBJECT_NAME
766 last_assemble_variable_decl = decl;
767 ASM_DECLARE_OBJECT_NAME (file, name, decl);
768 #else
769 /* Standard thing is just output label for the object. */
770 ASM_OUTPUT_LABEL (file, name);
771 #endif /* ASM_DECLARE_OBJECT_NAME */
772 ASM_OUTPUT_SKIP (file, rounded ? rounded : 1);
775 #endif
777 #ifdef ASM_OUTPUT_ALIGNED_BSS
779 /* Utility function for targets to use in implementing
780 ASM_OUTPUT_ALIGNED_BSS.
781 ??? It is believed that this function will work in most cases so such
782 support is localized here. */
784 static void
785 asm_output_aligned_bss (FILE *file, tree decl ATTRIBUTE_UNUSED,
786 const char *name, unsigned HOST_WIDE_INT size,
787 int align)
789 switch_to_section (bss_section);
790 ASM_OUTPUT_ALIGN (file, floor_log2 (align / BITS_PER_UNIT));
791 #ifdef ASM_DECLARE_OBJECT_NAME
792 last_assemble_variable_decl = decl;
793 ASM_DECLARE_OBJECT_NAME (file, name, decl);
794 #else
795 /* Standard thing is just output label for the object. */
796 ASM_OUTPUT_LABEL (file, name);
797 #endif /* ASM_DECLARE_OBJECT_NAME */
798 ASM_OUTPUT_SKIP (file, size ? size : 1);
801 #endif
803 #endif /* BSS_SECTION_ASM_OP */
805 #ifndef USE_SELECT_SECTION_FOR_FUNCTIONS
806 /* Return the hot section for function DECL. Return text_section for
807 null DECLs. */
809 static section *
810 hot_function_section (tree decl)
812 if (decl != NULL_TREE
813 && DECL_SECTION_NAME (decl) != NULL_TREE
814 && targetm.have_named_sections)
815 return get_named_section (decl, NULL, 0);
816 else
817 return text_section;
819 #endif
821 /* Return the section for function DECL.
823 If DECL is NULL_TREE, return the text section. We can be passed
824 NULL_TREE under some circumstances by dbxout.c at least. */
826 section *
827 function_section (tree decl)
829 int reloc = 0;
831 if (first_function_block_is_cold)
832 reloc = 1;
834 #ifdef USE_SELECT_SECTION_FOR_FUNCTIONS
835 if (decl != NULL_TREE
836 && DECL_SECTION_NAME (decl) != NULL_TREE)
837 return reloc ? unlikely_text_section ()
838 : get_named_section (decl, NULL, 0);
839 else
840 return targetm.asm_out.select_section (decl, reloc, DECL_ALIGN (decl));
841 #else
842 return reloc ? unlikely_text_section () : hot_function_section (decl);
843 #endif
846 section *
847 current_function_section (void)
849 #ifdef USE_SELECT_SECTION_FOR_FUNCTIONS
850 if (current_function_decl != NULL_TREE
851 && DECL_SECTION_NAME (current_function_decl) != NULL_TREE)
852 return in_cold_section_p ? unlikely_text_section ()
853 : get_named_section (current_function_decl,
854 NULL, 0);
855 else
856 return targetm.asm_out.select_section (current_function_decl,
857 in_cold_section_p,
858 DECL_ALIGN (current_function_decl));
859 #else
860 return (in_cold_section_p
861 ? unlikely_text_section ()
862 : hot_function_section (current_function_decl));
863 #endif
866 /* Return the read-only data section associated with function DECL. */
868 section *
869 default_function_rodata_section (tree decl)
871 if (decl != NULL_TREE && DECL_SECTION_NAME (decl))
873 const char *name = TREE_STRING_POINTER (DECL_SECTION_NAME (decl));
875 if (DECL_ONE_ONLY (decl) && HAVE_COMDAT_GROUP)
877 const char *dot;
878 size_t len;
879 char* rname;
881 dot = strchr (name + 1, '.');
882 if (!dot)
883 dot = name;
884 len = strlen (dot) + 8;
885 rname = (char *) alloca (len);
887 strcpy (rname, ".rodata");
888 strcat (rname, dot);
889 return get_section (rname, SECTION_LINKONCE, decl);
891 /* For .gnu.linkonce.t.foo we want to use .gnu.linkonce.r.foo. */
892 else if (DECL_ONE_ONLY (decl)
893 && strncmp (name, ".gnu.linkonce.t.", 16) == 0)
895 size_t len = strlen (name) + 1;
896 char *rname = (char *) alloca (len);
898 memcpy (rname, name, len);
899 rname[14] = 'r';
900 return get_section (rname, SECTION_LINKONCE, decl);
902 /* For .text.foo we want to use .rodata.foo. */
903 else if (flag_function_sections && flag_data_sections
904 && strncmp (name, ".text.", 6) == 0)
906 size_t len = strlen (name) + 1;
907 char *rname = (char *) alloca (len + 2);
909 memcpy (rname, ".rodata", 7);
910 memcpy (rname + 7, name + 5, len - 5);
911 return get_section (rname, 0, decl);
915 return readonly_data_section;
918 /* Return the read-only data section associated with function DECL
919 for targets where that section should be always the single
920 readonly data section. */
922 section *
923 default_no_function_rodata_section (tree decl ATTRIBUTE_UNUSED)
925 return readonly_data_section;
928 /* Return the section to use for string merging. */
930 static section *
931 mergeable_string_section (tree decl ATTRIBUTE_UNUSED,
932 unsigned HOST_WIDE_INT align ATTRIBUTE_UNUSED,
933 unsigned int flags ATTRIBUTE_UNUSED)
935 HOST_WIDE_INT len;
937 if (HAVE_GAS_SHF_MERGE && flag_merge_constants
938 && TREE_CODE (decl) == STRING_CST
939 && TREE_CODE (TREE_TYPE (decl)) == ARRAY_TYPE
940 && align <= 256
941 && (len = int_size_in_bytes (TREE_TYPE (decl))) > 0
942 && TREE_STRING_LENGTH (decl) >= len)
944 enum machine_mode mode;
945 unsigned int modesize;
946 const char *str;
947 HOST_WIDE_INT i;
948 int j, unit;
949 char name[30];
951 mode = TYPE_MODE (TREE_TYPE (TREE_TYPE (decl)));
952 modesize = GET_MODE_BITSIZE (mode);
953 if (modesize >= 8 && modesize <= 256
954 && (modesize & (modesize - 1)) == 0)
956 if (align < modesize)
957 align = modesize;
959 str = TREE_STRING_POINTER (decl);
960 unit = GET_MODE_SIZE (mode);
962 /* Check for embedded NUL characters. */
963 for (i = 0; i < len; i += unit)
965 for (j = 0; j < unit; j++)
966 if (str[i + j] != '\0')
967 break;
968 if (j == unit)
969 break;
971 if (i == len - unit)
973 sprintf (name, ".rodata.str%d.%d", modesize / 8,
974 (int) (align / 8));
975 flags |= (modesize / 8) | SECTION_MERGE | SECTION_STRINGS;
976 return get_section (name, flags, NULL);
981 return readonly_data_section;
984 /* Return the section to use for constant merging. */
986 section *
987 mergeable_constant_section (enum machine_mode mode ATTRIBUTE_UNUSED,
988 unsigned HOST_WIDE_INT align ATTRIBUTE_UNUSED,
989 unsigned int flags ATTRIBUTE_UNUSED)
991 unsigned int modesize = GET_MODE_BITSIZE (mode);
993 if (HAVE_GAS_SHF_MERGE && flag_merge_constants
994 && mode != VOIDmode
995 && mode != BLKmode
996 && modesize <= align
997 && align >= 8
998 && align <= 256
999 && (align & (align - 1)) == 0)
1001 char name[24];
1003 sprintf (name, ".rodata.cst%d", (int) (align / 8));
1004 flags |= (align / 8) | SECTION_MERGE;
1005 return get_section (name, flags, NULL);
1007 return readonly_data_section;
1010 /* Given NAME, a putative register name, discard any customary prefixes. */
1012 static const char *
1013 strip_reg_name (const char *name)
1015 #ifdef REGISTER_PREFIX
1016 if (!strncmp (name, REGISTER_PREFIX, strlen (REGISTER_PREFIX)))
1017 name += strlen (REGISTER_PREFIX);
1018 #endif
1019 if (name[0] == '%' || name[0] == '#')
1020 name++;
1021 return name;
1024 /* The user has asked for a DECL to have a particular name. Set (or
1025 change) it in such a way that we don't prefix an underscore to
1026 it. */
1027 void
1028 set_user_assembler_name (tree decl, const char *name)
1030 char *starred = (char *) alloca (strlen (name) + 2);
1031 starred[0] = '*';
1032 strcpy (starred + 1, name);
1033 change_decl_assembler_name (decl, get_identifier (starred));
1034 SET_DECL_RTL (decl, NULL_RTX);
1037 /* Decode an `asm' spec for a declaration as a register name.
1038 Return the register number, or -1 if nothing specified,
1039 or -2 if the ASMSPEC is not `cc' or `memory' and is not recognized,
1040 or -3 if ASMSPEC is `cc' and is not recognized,
1041 or -4 if ASMSPEC is `memory' and is not recognized.
1042 Accept an exact spelling or a decimal number.
1043 Prefixes such as % are optional. */
1046 decode_reg_name (const char *asmspec)
1048 if (asmspec != 0)
1050 int i;
1052 /* Get rid of confusing prefixes. */
1053 asmspec = strip_reg_name (asmspec);
1055 /* Allow a decimal number as a "register name". */
1056 for (i = strlen (asmspec) - 1; i >= 0; i--)
1057 if (! ISDIGIT (asmspec[i]))
1058 break;
1059 if (asmspec[0] != 0 && i < 0)
1061 i = atoi (asmspec);
1062 if (i < FIRST_PSEUDO_REGISTER && i >= 0)
1063 return i;
1064 else
1065 return -2;
1068 for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
1069 if (reg_names[i][0]
1070 && ! strcmp (asmspec, strip_reg_name (reg_names[i])))
1071 return i;
1073 #ifdef ADDITIONAL_REGISTER_NAMES
1075 static const struct { const char *const name; const int number; } table[]
1076 = ADDITIONAL_REGISTER_NAMES;
1078 for (i = 0; i < (int) ARRAY_SIZE (table); i++)
1079 if (table[i].name[0]
1080 && ! strcmp (asmspec, table[i].name))
1081 return table[i].number;
1083 #endif /* ADDITIONAL_REGISTER_NAMES */
1085 if (!strcmp (asmspec, "memory"))
1086 return -4;
1088 if (!strcmp (asmspec, "cc"))
1089 return -3;
1091 return -2;
1094 return -1;
1097 /* Return true if DECL's initializer is suitable for a BSS section. */
1099 static bool
1100 bss_initializer_p (const_tree decl)
1102 return (DECL_INITIAL (decl) == NULL
1103 || DECL_INITIAL (decl) == error_mark_node
1104 || (flag_zero_initialized_in_bss
1105 /* Leave constant zeroes in .rodata so they
1106 can be shared. */
1107 && !TREE_READONLY (decl)
1108 && initializer_zerop (DECL_INITIAL (decl))));
1111 /* Compute the alignment of variable specified by DECL.
1112 DONT_OUTPUT_DATA is from assemble_variable. */
1114 void
1115 align_variable (tree decl, bool dont_output_data)
1117 unsigned int align = DECL_ALIGN (decl);
1119 /* In the case for initialing an array whose length isn't specified,
1120 where we have not yet been able to do the layout,
1121 figure out the proper alignment now. */
1122 if (dont_output_data && DECL_SIZE (decl) == 0
1123 && TREE_CODE (TREE_TYPE (decl)) == ARRAY_TYPE)
1124 align = MAX (align, TYPE_ALIGN (TREE_TYPE (TREE_TYPE (decl))));
1126 /* Some object file formats have a maximum alignment which they support.
1127 In particular, a.out format supports a maximum alignment of 4. */
1128 if (align > MAX_OFILE_ALIGNMENT)
1130 warning (0, "alignment of %q+D is greater than maximum object "
1131 "file alignment. Using %d", decl,
1132 MAX_OFILE_ALIGNMENT/BITS_PER_UNIT);
1133 align = MAX_OFILE_ALIGNMENT;
1136 /* On some machines, it is good to increase alignment sometimes. */
1137 if (! DECL_USER_ALIGN (decl))
1139 #ifdef DATA_ALIGNMENT
1140 unsigned int data_align = DATA_ALIGNMENT (TREE_TYPE (decl), align);
1141 /* Don't increase alignment too much for TLS variables - TLS space
1142 is too precious. */
1143 if (! DECL_THREAD_LOCAL_P (decl) || data_align <= BITS_PER_WORD)
1144 align = data_align;
1145 #endif
1146 #ifdef CONSTANT_ALIGNMENT
1147 if (DECL_INITIAL (decl) != 0 && DECL_INITIAL (decl) != error_mark_node)
1149 unsigned int const_align = CONSTANT_ALIGNMENT (DECL_INITIAL (decl),
1150 align);
1151 /* Don't increase alignment too much for TLS variables - TLS space
1152 is too precious. */
1153 if (! DECL_THREAD_LOCAL_P (decl) || const_align <= BITS_PER_WORD)
1154 align = const_align;
1156 #endif
1159 /* Reset the alignment in case we have made it tighter, so we can benefit
1160 from it in get_pointer_alignment. */
1161 DECL_ALIGN (decl) = align;
1164 /* Return the section into which the given VAR_DECL or CONST_DECL
1165 should be placed. PREFER_NOSWITCH_P is true if a noswitch
1166 section should be used wherever possible. */
1168 static section *
1169 get_variable_section (tree decl, bool prefer_noswitch_p)
1171 int reloc;
1173 /* If the decl has been given an explicit section name, then it
1174 isn't common, and shouldn't be handled as such. */
1175 if (DECL_COMMON (decl) && DECL_SECTION_NAME (decl) == NULL)
1177 if (DECL_THREAD_LOCAL_P (decl))
1178 return tls_comm_section;
1179 /* This cannot be common bss for an emulated TLS object without
1180 a register_common hook. */
1181 else if (DECL_TLS_MODEL (decl) == TLS_MODEL_EMULATED
1182 && !targetm.emutls.register_common)
1184 else if (TREE_PUBLIC (decl) && bss_initializer_p (decl))
1185 return comm_section;
1188 if (DECL_INITIAL (decl) == error_mark_node)
1189 reloc = contains_pointers_p (TREE_TYPE (decl)) ? 3 : 0;
1190 else if (DECL_INITIAL (decl))
1191 reloc = compute_reloc_for_constant (DECL_INITIAL (decl));
1192 else
1193 reloc = 0;
1195 resolve_unique_section (decl, reloc, flag_data_sections);
1196 if (IN_NAMED_SECTION (decl))
1197 return get_named_section (decl, NULL, reloc);
1199 if (!DECL_THREAD_LOCAL_P (decl)
1200 && !(prefer_noswitch_p && targetm.have_switchable_bss_sections)
1201 && bss_initializer_p (decl))
1203 if (!TREE_PUBLIC (decl))
1204 return lcomm_section;
1205 if (bss_noswitch_section)
1206 return bss_noswitch_section;
1209 return targetm.asm_out.select_section (decl, reloc, DECL_ALIGN (decl));
1212 /* Return the block into which object_block DECL should be placed. */
1214 static struct object_block *
1215 get_block_for_decl (tree decl)
1217 section *sect;
1219 if (TREE_CODE (decl) == VAR_DECL)
1221 /* The object must be defined in this translation unit. */
1222 if (DECL_EXTERNAL (decl))
1223 return NULL;
1225 /* There's no point using object blocks for something that is
1226 isolated by definition. */
1227 if (DECL_ONE_ONLY (decl))
1228 return NULL;
1231 /* We can only calculate block offsets if the decl has a known
1232 constant size. */
1233 if (DECL_SIZE_UNIT (decl) == NULL)
1234 return NULL;
1235 if (!host_integerp (DECL_SIZE_UNIT (decl), 1))
1236 return NULL;
1238 /* Find out which section should contain DECL. We cannot put it into
1239 an object block if it requires a standalone definition. */
1240 if (TREE_CODE (decl) == VAR_DECL)
1241 align_variable (decl, 0);
1242 sect = get_variable_section (decl, true);
1243 if (SECTION_STYLE (sect) == SECTION_NOSWITCH)
1244 return NULL;
1246 return get_block_for_section (sect);
1249 /* Make sure block symbol SYMBOL is in block BLOCK. */
1251 static void
1252 change_symbol_block (rtx symbol, struct object_block *block)
1254 if (block != SYMBOL_REF_BLOCK (symbol))
1256 gcc_assert (SYMBOL_REF_BLOCK_OFFSET (symbol) < 0);
1257 SYMBOL_REF_BLOCK (symbol) = block;
1261 /* Return true if it is possible to put DECL in an object_block. */
1263 static bool
1264 use_blocks_for_decl_p (tree decl)
1266 /* Only data DECLs can be placed into object blocks. */
1267 if (TREE_CODE (decl) != VAR_DECL && TREE_CODE (decl) != CONST_DECL)
1268 return false;
1270 /* Detect decls created by dw2_force_const_mem. Such decls are
1271 special because DECL_INITIAL doesn't specify the decl's true value.
1272 dw2_output_indirect_constants will instead call assemble_variable
1273 with dont_output_data set to 1 and then print the contents itself. */
1274 if (DECL_INITIAL (decl) == decl)
1275 return false;
1277 /* If this decl is an alias, then we don't want to emit a definition. */
1278 if (lookup_attribute ("alias", DECL_ATTRIBUTES (decl)))
1279 return false;
1281 return true;
1284 /* Create the DECL_RTL for a VAR_DECL or FUNCTION_DECL. DECL should
1285 have static storage duration. In other words, it should not be an
1286 automatic variable, including PARM_DECLs.
1288 There is, however, one exception: this function handles variables
1289 explicitly placed in a particular register by the user.
1291 This is never called for PARM_DECL nodes. */
1293 void
1294 make_decl_rtl (tree decl)
1296 const char *name = 0;
1297 int reg_number;
1298 rtx x;
1300 /* Check that we are not being given an automatic variable. */
1301 gcc_assert (TREE_CODE (decl) != PARM_DECL
1302 && TREE_CODE (decl) != RESULT_DECL);
1304 /* A weak alias has TREE_PUBLIC set but not the other bits. */
1305 gcc_assert (TREE_CODE (decl) != VAR_DECL
1306 || TREE_STATIC (decl)
1307 || TREE_PUBLIC (decl)
1308 || DECL_EXTERNAL (decl)
1309 || DECL_REGISTER (decl));
1311 /* And that we were not given a type or a label. */
1312 gcc_assert (TREE_CODE (decl) != TYPE_DECL
1313 && TREE_CODE (decl) != LABEL_DECL);
1315 /* For a duplicate declaration, we can be called twice on the
1316 same DECL node. Don't discard the RTL already made. */
1317 if (DECL_RTL_SET_P (decl))
1319 /* If the old RTL had the wrong mode, fix the mode. */
1320 x = DECL_RTL (decl);
1321 if (GET_MODE (x) != DECL_MODE (decl))
1322 SET_DECL_RTL (decl, adjust_address_nv (x, DECL_MODE (decl), 0));
1324 if (TREE_CODE (decl) != FUNCTION_DECL && DECL_REGISTER (decl))
1325 return;
1327 /* ??? Another way to do this would be to maintain a hashed
1328 table of such critters. Instead of adding stuff to a DECL
1329 to give certain attributes to it, we could use an external
1330 hash map from DECL to set of attributes. */
1332 /* Let the target reassign the RTL if it wants.
1333 This is necessary, for example, when one machine specific
1334 decl attribute overrides another. */
1335 targetm.encode_section_info (decl, DECL_RTL (decl), false);
1337 /* If the symbol has a SYMBOL_REF_BLOCK field, update it based
1338 on the new decl information. */
1339 if (MEM_P (x)
1340 && GET_CODE (XEXP (x, 0)) == SYMBOL_REF
1341 && SYMBOL_REF_HAS_BLOCK_INFO_P (XEXP (x, 0)))
1342 change_symbol_block (XEXP (x, 0), get_block_for_decl (decl));
1344 /* Make this function static known to the mudflap runtime. */
1345 if (flag_mudflap && TREE_CODE (decl) == VAR_DECL)
1346 mudflap_enqueue_decl (decl);
1348 return;
1351 name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
1353 if (name[0] != '*' && TREE_CODE (decl) != FUNCTION_DECL
1354 && DECL_REGISTER (decl))
1356 error ("register name not specified for %q+D", decl);
1358 else if (TREE_CODE (decl) != FUNCTION_DECL && DECL_REGISTER (decl))
1360 const char *asmspec = name+1;
1361 reg_number = decode_reg_name (asmspec);
1362 /* First detect errors in declaring global registers. */
1363 if (reg_number == -1)
1364 error ("register name not specified for %q+D", decl);
1365 else if (reg_number < 0)
1366 error ("invalid register name for %q+D", decl);
1367 else if (TYPE_MODE (TREE_TYPE (decl)) == BLKmode)
1368 error ("data type of %q+D isn%'t suitable for a register",
1369 decl);
1370 else if (! HARD_REGNO_MODE_OK (reg_number, TYPE_MODE (TREE_TYPE (decl))))
1371 error ("register specified for %q+D isn%'t suitable for data type",
1372 decl);
1373 /* Now handle properly declared static register variables. */
1374 else
1376 int nregs;
1378 if (DECL_INITIAL (decl) != 0 && TREE_STATIC (decl))
1380 DECL_INITIAL (decl) = 0;
1381 error ("global register variable has initial value");
1383 if (TREE_THIS_VOLATILE (decl))
1384 warning (OPT_Wvolatile_register_var,
1385 "optimization may eliminate reads and/or "
1386 "writes to register variables");
1388 /* If the user specified one of the eliminables registers here,
1389 e.g., FRAME_POINTER_REGNUM, we don't want to get this variable
1390 confused with that register and be eliminated. This usage is
1391 somewhat suspect... */
1393 SET_DECL_RTL (decl, gen_rtx_raw_REG (DECL_MODE (decl), reg_number));
1394 ORIGINAL_REGNO (DECL_RTL (decl)) = reg_number;
1395 REG_USERVAR_P (DECL_RTL (decl)) = 1;
1397 if (TREE_STATIC (decl))
1399 /* Make this register global, so not usable for anything
1400 else. */
1401 #ifdef ASM_DECLARE_REGISTER_GLOBAL
1402 name = IDENTIFIER_POINTER (DECL_NAME (decl));
1403 ASM_DECLARE_REGISTER_GLOBAL (asm_out_file, decl, reg_number, name);
1404 #endif
1405 nregs = hard_regno_nregs[reg_number][DECL_MODE (decl)];
1406 while (nregs > 0)
1407 globalize_reg (reg_number + --nregs);
1410 /* As a register variable, it has no section. */
1411 return;
1414 /* Now handle ordinary static variables and functions (in memory).
1415 Also handle vars declared register invalidly. */
1416 else if (name[0] == '*')
1418 #ifdef REGISTER_PREFIX
1419 if (strlen (REGISTER_PREFIX) != 0)
1421 reg_number = decode_reg_name (name);
1422 if (reg_number >= 0 || reg_number == -3)
1423 error ("register name given for non-register variable %q+D", decl);
1425 #endif
1428 /* Specifying a section attribute on a variable forces it into a
1429 non-.bss section, and thus it cannot be common. */
1430 if (TREE_CODE (decl) == VAR_DECL
1431 && DECL_SECTION_NAME (decl) != NULL_TREE
1432 && DECL_INITIAL (decl) == NULL_TREE
1433 && DECL_COMMON (decl))
1434 DECL_COMMON (decl) = 0;
1436 /* Variables can't be both common and weak. */
1437 if (TREE_CODE (decl) == VAR_DECL && DECL_WEAK (decl))
1438 DECL_COMMON (decl) = 0;
1440 if (use_object_blocks_p () && use_blocks_for_decl_p (decl))
1441 x = create_block_symbol (name, get_block_for_decl (decl), -1);
1442 else
1443 x = gen_rtx_SYMBOL_REF (Pmode, name);
1444 SYMBOL_REF_WEAK (x) = DECL_WEAK (decl);
1445 SET_SYMBOL_REF_DECL (x, decl);
1447 x = gen_rtx_MEM (DECL_MODE (decl), x);
1448 if (TREE_CODE (decl) != FUNCTION_DECL)
1449 set_mem_attributes (x, decl, 1);
1450 SET_DECL_RTL (decl, x);
1452 /* Optionally set flags or add text to the name to record information
1453 such as that it is a function name.
1454 If the name is changed, the macro ASM_OUTPUT_LABELREF
1455 will have to know how to strip this information. */
1456 targetm.encode_section_info (decl, DECL_RTL (decl), true);
1458 /* Make this function static known to the mudflap runtime. */
1459 if (flag_mudflap && TREE_CODE (decl) == VAR_DECL)
1460 mudflap_enqueue_decl (decl);
1463 /* Output a string of literal assembler code
1464 for an `asm' keyword used between functions. */
1466 void
1467 assemble_asm (tree string)
1469 app_enable ();
1471 if (TREE_CODE (string) == ADDR_EXPR)
1472 string = TREE_OPERAND (string, 0);
1474 fprintf (asm_out_file, "\t%s\n", TREE_STRING_POINTER (string));
1477 /* Record an element in the table of global destructors. SYMBOL is
1478 a SYMBOL_REF of the function to be called; PRIORITY is a number
1479 between 0 and MAX_INIT_PRIORITY. */
1481 void
1482 default_stabs_asm_out_destructor (rtx symbol ATTRIBUTE_UNUSED,
1483 int priority ATTRIBUTE_UNUSED)
1485 #if defined DBX_DEBUGGING_INFO || defined XCOFF_DEBUGGING_INFO
1486 /* Tell GNU LD that this is part of the static destructor set.
1487 This will work for any system that uses stabs, most usefully
1488 aout systems. */
1489 dbxout_begin_simple_stabs ("___DTOR_LIST__", 22 /* N_SETT */);
1490 dbxout_stab_value_label (XSTR (symbol, 0));
1491 #else
1492 sorry ("global destructors not supported on this target");
1493 #endif
1496 /* Write the address of the entity given by SYMBOL to SEC. */
1497 void
1498 assemble_addr_to_section (rtx symbol, section *sec)
1500 switch_to_section (sec);
1501 assemble_align (POINTER_SIZE);
1502 assemble_integer (symbol, POINTER_SIZE / BITS_PER_UNIT, POINTER_SIZE, 1);
1505 /* Return the numbered .ctors.N (if CONSTRUCTOR_P) or .dtors.N (if
1506 not) section for PRIORITY. */
1507 section *
1508 get_cdtor_priority_section (int priority, bool constructor_p)
1510 char buf[16];
1512 /* ??? This only works reliably with the GNU linker. */
1513 sprintf (buf, "%s.%.5u",
1514 constructor_p ? ".ctors" : ".dtors",
1515 /* Invert the numbering so the linker puts us in the proper
1516 order; constructors are run from right to left, and the
1517 linker sorts in increasing order. */
1518 MAX_INIT_PRIORITY - priority);
1519 return get_section (buf, SECTION_WRITE, NULL);
1522 void
1523 default_named_section_asm_out_destructor (rtx symbol, int priority)
1525 section *sec;
1527 if (priority != DEFAULT_INIT_PRIORITY)
1528 sec = get_cdtor_priority_section (priority,
1529 /*constructor_p=*/false);
1530 else
1531 sec = get_section (".dtors", SECTION_WRITE, NULL);
1533 assemble_addr_to_section (symbol, sec);
1536 #ifdef DTORS_SECTION_ASM_OP
1537 void
1538 default_dtor_section_asm_out_destructor (rtx symbol,
1539 int priority ATTRIBUTE_UNUSED)
1541 assemble_addr_to_section (symbol, dtors_section);
1543 #endif
1545 /* Likewise for global constructors. */
1547 void
1548 default_stabs_asm_out_constructor (rtx symbol ATTRIBUTE_UNUSED,
1549 int priority ATTRIBUTE_UNUSED)
1551 #if defined DBX_DEBUGGING_INFO || defined XCOFF_DEBUGGING_INFO
1552 /* Tell GNU LD that this is part of the static destructor set.
1553 This will work for any system that uses stabs, most usefully
1554 aout systems. */
1555 dbxout_begin_simple_stabs ("___CTOR_LIST__", 22 /* N_SETT */);
1556 dbxout_stab_value_label (XSTR (symbol, 0));
1557 #else
1558 sorry ("global constructors not supported on this target");
1559 #endif
1562 void
1563 default_named_section_asm_out_constructor (rtx symbol, int priority)
1565 section *sec;
1567 if (priority != DEFAULT_INIT_PRIORITY)
1568 sec = get_cdtor_priority_section (priority,
1569 /*constructor_p=*/true);
1570 else
1571 sec = get_section (".ctors", SECTION_WRITE, NULL);
1573 assemble_addr_to_section (symbol, sec);
1576 #ifdef CTORS_SECTION_ASM_OP
1577 void
1578 default_ctor_section_asm_out_constructor (rtx symbol,
1579 int priority ATTRIBUTE_UNUSED)
1581 assemble_addr_to_section (symbol, ctors_section);
1583 #endif
1585 /* CONSTANT_POOL_BEFORE_FUNCTION may be defined as an expression with
1586 a nonzero value if the constant pool should be output before the
1587 start of the function, or a zero value if the pool should output
1588 after the end of the function. The default is to put it before the
1589 start. */
1591 #ifndef CONSTANT_POOL_BEFORE_FUNCTION
1592 #define CONSTANT_POOL_BEFORE_FUNCTION 1
1593 #endif
1595 /* DECL is an object (either VAR_DECL or FUNCTION_DECL) which is going
1596 to be output to assembler.
1597 Set first_global_object_name and weak_global_object_name as appropriate. */
1599 void
1600 notice_global_symbol (tree decl)
1602 const char **type = &first_global_object_name;
1604 if (first_global_object_name
1605 || !TREE_PUBLIC (decl)
1606 || DECL_EXTERNAL (decl)
1607 || !DECL_NAME (decl)
1608 || (TREE_CODE (decl) != FUNCTION_DECL
1609 && (TREE_CODE (decl) != VAR_DECL
1610 || (DECL_COMMON (decl)
1611 && (DECL_INITIAL (decl) == 0
1612 || DECL_INITIAL (decl) == error_mark_node))))
1613 || !MEM_P (DECL_RTL (decl)))
1614 return;
1616 /* We win when global object is found, but it is useful to know about weak
1617 symbol as well so we can produce nicer unique names. */
1618 if (DECL_WEAK (decl) || DECL_ONE_ONLY (decl) || flag_shlib)
1619 type = &weak_global_object_name;
1621 if (!*type)
1623 const char *p;
1624 const char *name;
1625 rtx decl_rtl = DECL_RTL (decl);
1627 p = targetm.strip_name_encoding (XSTR (XEXP (decl_rtl, 0), 0));
1628 name = ggc_strdup (p);
1630 *type = name;
1634 /* Output assembler code for the constant pool of a function and associated
1635 with defining the name of the function. DECL describes the function.
1636 NAME is the function's name. For the constant pool, we use the current
1637 constant pool data. */
1639 void
1640 assemble_start_function (tree decl, const char *fnname)
1642 int align;
1643 char tmp_label[100];
1644 bool hot_label_written = false;
1646 crtl->subsections.unlikely_text_section_name = NULL;
1648 first_function_block_is_cold = false;
1649 if (flag_reorder_blocks_and_partition)
1651 ASM_GENERATE_INTERNAL_LABEL (tmp_label, "LHOTB", const_labelno);
1652 crtl->subsections.hot_section_label = ggc_strdup (tmp_label);
1653 ASM_GENERATE_INTERNAL_LABEL (tmp_label, "LCOLDB", const_labelno);
1654 crtl->subsections.cold_section_label = ggc_strdup (tmp_label);
1655 ASM_GENERATE_INTERNAL_LABEL (tmp_label, "LHOTE", const_labelno);
1656 crtl->subsections.hot_section_end_label = ggc_strdup (tmp_label);
1657 ASM_GENERATE_INTERNAL_LABEL (tmp_label, "LCOLDE", const_labelno);
1658 crtl->subsections.cold_section_end_label = ggc_strdup (tmp_label);
1659 const_labelno++;
1661 else
1663 crtl->subsections.hot_section_label = NULL;
1664 crtl->subsections.cold_section_label = NULL;
1665 crtl->subsections.hot_section_end_label = NULL;
1666 crtl->subsections.cold_section_end_label = NULL;
1669 /* The following code does not need preprocessing in the assembler. */
1671 app_disable ();
1673 if (CONSTANT_POOL_BEFORE_FUNCTION)
1674 output_constant_pool (fnname, decl);
1676 resolve_unique_section (decl, 0, flag_function_sections);
1678 /* Make sure the not and cold text (code) sections are properly
1679 aligned. This is necessary here in the case where the function
1680 has both hot and cold sections, because we don't want to re-set
1681 the alignment when the section switch happens mid-function. */
1683 if (flag_reorder_blocks_and_partition)
1685 switch_to_section (unlikely_text_section ());
1686 assemble_align (DECL_ALIGN (decl));
1687 ASM_OUTPUT_LABEL (asm_out_file, crtl->subsections.cold_section_label);
1689 /* When the function starts with a cold section, we need to explicitly
1690 align the hot section and write out the hot section label.
1691 But if the current function is a thunk, we do not have a CFG. */
1692 if (!cfun->is_thunk
1693 && BB_PARTITION (ENTRY_BLOCK_PTR->next_bb) == BB_COLD_PARTITION)
1695 switch_to_section (text_section);
1696 assemble_align (DECL_ALIGN (decl));
1697 ASM_OUTPUT_LABEL (asm_out_file, crtl->subsections.hot_section_label);
1698 hot_label_written = true;
1699 first_function_block_is_cold = true;
1702 else if (DECL_SECTION_NAME (decl))
1704 /* Calls to function_section rely on first_function_block_is_cold
1705 being accurate. The first block may be cold even if we aren't
1706 doing partitioning, if the entire function was decided by
1707 choose_function_section (predict.c) to be cold. */
1709 initialize_cold_section_name ();
1711 if (crtl->subsections.unlikely_text_section_name
1712 && strcmp (TREE_STRING_POINTER (DECL_SECTION_NAME (decl)),
1713 crtl->subsections.unlikely_text_section_name) == 0)
1714 first_function_block_is_cold = true;
1717 in_cold_section_p = first_function_block_is_cold;
1719 /* Switch to the correct text section for the start of the function. */
1721 switch_to_section (function_section (decl));
1722 if (flag_reorder_blocks_and_partition
1723 && !hot_label_written)
1724 ASM_OUTPUT_LABEL (asm_out_file, crtl->subsections.hot_section_label);
1726 /* Tell assembler to move to target machine's alignment for functions. */
1727 align = floor_log2 (DECL_ALIGN (decl) / BITS_PER_UNIT);
1728 if (align > 0)
1730 ASM_OUTPUT_ALIGN (asm_out_file, align);
1733 /* Handle a user-specified function alignment.
1734 Note that we still need to align to DECL_ALIGN, as above,
1735 because ASM_OUTPUT_MAX_SKIP_ALIGN might not do any alignment at all. */
1736 if (! DECL_USER_ALIGN (decl)
1737 && align_functions_log > align
1738 && optimize_function_for_speed_p (cfun))
1740 #ifdef ASM_OUTPUT_MAX_SKIP_ALIGN
1741 ASM_OUTPUT_MAX_SKIP_ALIGN (asm_out_file,
1742 align_functions_log, align_functions - 1);
1743 #else
1744 ASM_OUTPUT_ALIGN (asm_out_file, align_functions_log);
1745 #endif
1748 #ifdef ASM_OUTPUT_FUNCTION_PREFIX
1749 ASM_OUTPUT_FUNCTION_PREFIX (asm_out_file, fnname);
1750 #endif
1752 (*debug_hooks->begin_function) (decl);
1754 /* Make function name accessible from other files, if appropriate. */
1756 if (TREE_PUBLIC (decl))
1758 notice_global_symbol (decl);
1760 globalize_decl (decl);
1762 maybe_assemble_visibility (decl);
1765 if (DECL_PRESERVE_P (decl))
1766 targetm.asm_out.mark_decl_preserved (fnname);
1768 /* Do any machine/system dependent processing of the function name. */
1769 #ifdef ASM_DECLARE_FUNCTION_NAME
1770 ASM_DECLARE_FUNCTION_NAME (asm_out_file, fnname, current_function_decl);
1771 #else
1772 /* Standard thing is just output label for the function. */
1773 ASM_OUTPUT_LABEL (asm_out_file, fnname);
1774 #endif /* ASM_DECLARE_FUNCTION_NAME */
1777 /* Output assembler code associated with defining the size of the
1778 function. DECL describes the function. NAME is the function's name. */
1780 void
1781 assemble_end_function (tree decl, const char *fnname ATTRIBUTE_UNUSED)
1783 #ifdef ASM_DECLARE_FUNCTION_SIZE
1784 /* We could have switched section in the middle of the function. */
1785 if (flag_reorder_blocks_and_partition)
1786 switch_to_section (function_section (decl));
1787 ASM_DECLARE_FUNCTION_SIZE (asm_out_file, fnname, decl);
1788 #endif
1789 if (! CONSTANT_POOL_BEFORE_FUNCTION)
1791 output_constant_pool (fnname, decl);
1792 switch_to_section (function_section (decl)); /* need to switch back */
1794 /* Output labels for end of hot/cold text sections (to be used by
1795 debug info.) */
1796 if (flag_reorder_blocks_and_partition)
1798 section *save_text_section;
1800 save_text_section = in_section;
1801 switch_to_section (unlikely_text_section ());
1802 ASM_OUTPUT_LABEL (asm_out_file, crtl->subsections.cold_section_end_label);
1803 if (first_function_block_is_cold)
1804 switch_to_section (text_section);
1805 else
1806 switch_to_section (function_section (decl));
1807 ASM_OUTPUT_LABEL (asm_out_file, crtl->subsections.hot_section_end_label);
1808 switch_to_section (save_text_section);
1812 /* Assemble code to leave SIZE bytes of zeros. */
1814 void
1815 assemble_zeros (unsigned HOST_WIDE_INT size)
1817 /* Do no output if -fsyntax-only. */
1818 if (flag_syntax_only)
1819 return;
1821 #ifdef ASM_NO_SKIP_IN_TEXT
1822 /* The `space' pseudo in the text section outputs nop insns rather than 0s,
1823 so we must output 0s explicitly in the text section. */
1824 if (ASM_NO_SKIP_IN_TEXT && (in_section->common.flags & SECTION_CODE) != 0)
1826 unsigned HOST_WIDE_INT i;
1827 for (i = 0; i < size; i++)
1828 assemble_integer (const0_rtx, 1, BITS_PER_UNIT, 1);
1830 else
1831 #endif
1832 if (size > 0)
1833 ASM_OUTPUT_SKIP (asm_out_file, size);
1836 /* Assemble an alignment pseudo op for an ALIGN-bit boundary. */
1838 void
1839 assemble_align (int align)
1841 if (align > BITS_PER_UNIT)
1843 ASM_OUTPUT_ALIGN (asm_out_file, floor_log2 (align / BITS_PER_UNIT));
1847 /* Assemble a string constant with the specified C string as contents. */
1849 void
1850 assemble_string (const char *p, int size)
1852 int pos = 0;
1853 int maximum = 2000;
1855 /* If the string is very long, split it up. */
1857 while (pos < size)
1859 int thissize = size - pos;
1860 if (thissize > maximum)
1861 thissize = maximum;
1863 ASM_OUTPUT_ASCII (asm_out_file, p, thissize);
1865 pos += thissize;
1866 p += thissize;
1871 /* A noswitch_section_callback for lcomm_section. */
1873 static bool
1874 emit_local (tree decl ATTRIBUTE_UNUSED,
1875 const char *name ATTRIBUTE_UNUSED,
1876 unsigned HOST_WIDE_INT size ATTRIBUTE_UNUSED,
1877 unsigned HOST_WIDE_INT rounded ATTRIBUTE_UNUSED)
1879 #if defined ASM_OUTPUT_ALIGNED_DECL_LOCAL
1880 ASM_OUTPUT_ALIGNED_DECL_LOCAL (asm_out_file, decl, name,
1881 size, DECL_ALIGN (decl));
1882 return true;
1883 #elif defined ASM_OUTPUT_ALIGNED_LOCAL
1884 ASM_OUTPUT_ALIGNED_LOCAL (asm_out_file, name, size, DECL_ALIGN (decl));
1885 return true;
1886 #else
1887 ASM_OUTPUT_LOCAL (asm_out_file, name, size, rounded);
1888 return false;
1889 #endif
1892 /* A noswitch_section_callback for bss_noswitch_section. */
1894 #if defined ASM_OUTPUT_ALIGNED_BSS || defined ASM_OUTPUT_BSS
1895 static bool
1896 emit_bss (tree decl ATTRIBUTE_UNUSED,
1897 const char *name ATTRIBUTE_UNUSED,
1898 unsigned HOST_WIDE_INT size ATTRIBUTE_UNUSED,
1899 unsigned HOST_WIDE_INT rounded ATTRIBUTE_UNUSED)
1901 #if defined ASM_OUTPUT_ALIGNED_BSS
1902 ASM_OUTPUT_ALIGNED_BSS (asm_out_file, decl, name, size, DECL_ALIGN (decl));
1903 return true;
1904 #else
1905 ASM_OUTPUT_BSS (asm_out_file, decl, name, size, rounded);
1906 return false;
1907 #endif
1909 #endif
1911 /* A noswitch_section_callback for comm_section. */
1913 static bool
1914 emit_common (tree decl ATTRIBUTE_UNUSED,
1915 const char *name ATTRIBUTE_UNUSED,
1916 unsigned HOST_WIDE_INT size ATTRIBUTE_UNUSED,
1917 unsigned HOST_WIDE_INT rounded ATTRIBUTE_UNUSED)
1919 #if defined ASM_OUTPUT_ALIGNED_DECL_COMMON
1920 ASM_OUTPUT_ALIGNED_DECL_COMMON (asm_out_file, decl, name,
1921 size, DECL_ALIGN (decl));
1922 return true;
1923 #elif defined ASM_OUTPUT_ALIGNED_COMMON
1924 ASM_OUTPUT_ALIGNED_COMMON (asm_out_file, name, size, DECL_ALIGN (decl));
1925 return true;
1926 #else
1927 ASM_OUTPUT_COMMON (asm_out_file, name, size, rounded);
1928 return false;
1929 #endif
1932 /* A noswitch_section_callback for tls_comm_section. */
1934 static bool
1935 emit_tls_common (tree decl ATTRIBUTE_UNUSED,
1936 const char *name ATTRIBUTE_UNUSED,
1937 unsigned HOST_WIDE_INT size ATTRIBUTE_UNUSED,
1938 unsigned HOST_WIDE_INT rounded ATTRIBUTE_UNUSED)
1940 #ifdef ASM_OUTPUT_TLS_COMMON
1941 ASM_OUTPUT_TLS_COMMON (asm_out_file, decl, name, size);
1942 return true;
1943 #else
1944 sorry ("thread-local COMMON data not implemented");
1945 return true;
1946 #endif
1949 /* Assemble DECL given that it belongs in SECTION_NOSWITCH section SECT.
1950 NAME is the name of DECL's SYMBOL_REF. */
1952 static void
1953 assemble_noswitch_variable (tree decl, const char *name, section *sect)
1955 unsigned HOST_WIDE_INT size, rounded;
1957 size = tree_low_cst (DECL_SIZE_UNIT (decl), 1);
1958 rounded = size;
1960 /* Don't allocate zero bytes of common,
1961 since that means "undefined external" in the linker. */
1962 if (size == 0)
1963 rounded = 1;
1965 /* Round size up to multiple of BIGGEST_ALIGNMENT bits
1966 so that each uninitialized object starts on such a boundary. */
1967 rounded += (BIGGEST_ALIGNMENT / BITS_PER_UNIT) - 1;
1968 rounded = (rounded / (BIGGEST_ALIGNMENT / BITS_PER_UNIT)
1969 * (BIGGEST_ALIGNMENT / BITS_PER_UNIT));
1971 if (!sect->noswitch.callback (decl, name, size, rounded)
1972 && (unsigned HOST_WIDE_INT) DECL_ALIGN_UNIT (decl) > rounded)
1973 warning (0, "requested alignment for %q+D is greater than "
1974 "implemented alignment of %wu", decl, rounded);
1977 /* A subroutine of assemble_variable. Output the label and contents of
1978 DECL, whose address is a SYMBOL_REF with name NAME. DONT_OUTPUT_DATA
1979 is as for assemble_variable. */
1981 static void
1982 assemble_variable_contents (tree decl, const char *name,
1983 bool dont_output_data)
1985 /* Do any machine/system dependent processing of the object. */
1986 #ifdef ASM_DECLARE_OBJECT_NAME
1987 last_assemble_variable_decl = decl;
1988 ASM_DECLARE_OBJECT_NAME (asm_out_file, name, decl);
1989 #else
1990 /* Standard thing is just output label for the object. */
1991 ASM_OUTPUT_LABEL (asm_out_file, name);
1992 #endif /* ASM_DECLARE_OBJECT_NAME */
1994 if (!dont_output_data)
1996 if (DECL_INITIAL (decl)
1997 && DECL_INITIAL (decl) != error_mark_node
1998 && !initializer_zerop (DECL_INITIAL (decl)))
1999 /* Output the actual data. */
2000 output_constant (DECL_INITIAL (decl),
2001 tree_low_cst (DECL_SIZE_UNIT (decl), 1),
2002 DECL_ALIGN (decl));
2003 else
2004 /* Leave space for it. */
2005 assemble_zeros (tree_low_cst (DECL_SIZE_UNIT (decl), 1));
2009 /* Initialize emulated tls object TO, which refers to TLS variable
2010 DECL and is initialized by PROXY. */
2012 tree
2013 default_emutls_var_init (tree to, tree decl, tree proxy)
2015 VEC(constructor_elt,gc) *v = VEC_alloc (constructor_elt, gc, 4);
2016 constructor_elt *elt;
2017 tree type = TREE_TYPE (to);
2018 tree field = TYPE_FIELDS (type);
2020 elt = VEC_quick_push (constructor_elt, v, NULL);
2021 elt->index = field;
2022 elt->value = fold_convert (TREE_TYPE (field), DECL_SIZE_UNIT (decl));
2024 elt = VEC_quick_push (constructor_elt, v, NULL);
2025 field = TREE_CHAIN (field);
2026 elt->index = field;
2027 elt->value = build_int_cst (TREE_TYPE (field),
2028 DECL_ALIGN_UNIT (decl));
2030 elt = VEC_quick_push (constructor_elt, v, NULL);
2031 field = TREE_CHAIN (field);
2032 elt->index = field;
2033 elt->value = null_pointer_node;
2035 elt = VEC_quick_push (constructor_elt, v, NULL);
2036 field = TREE_CHAIN (field);
2037 elt->index = field;
2038 elt->value = proxy;
2040 return build_constructor (type, v);
2043 /* Assemble everything that is needed for a variable or function declaration.
2044 Not used for automatic variables, and not used for function definitions.
2045 Should not be called for variables of incomplete structure type.
2047 TOP_LEVEL is nonzero if this variable has file scope.
2048 AT_END is nonzero if this is the special handling, at end of compilation,
2049 to define things that have had only tentative definitions.
2050 DONT_OUTPUT_DATA if nonzero means don't actually output the
2051 initial value (that will be done by the caller). */
2053 void
2054 assemble_variable (tree decl, int top_level ATTRIBUTE_UNUSED,
2055 int at_end ATTRIBUTE_UNUSED, int dont_output_data)
2057 const char *name;
2058 rtx decl_rtl, symbol;
2059 section *sect;
2061 if (! targetm.have_tls
2062 && TREE_CODE (decl) == VAR_DECL
2063 && DECL_THREAD_LOCAL_P (decl))
2065 tree to = emutls_decl (decl);
2067 /* If this variable is defined locally, then we need to initialize the
2068 control structure with size and alignment information. We do this
2069 at the last moment because tentative definitions can take a locally
2070 defined but uninitialized variable and initialize it later, which
2071 would result in incorrect contents. */
2072 if (! DECL_EXTERNAL (to)
2073 && (! DECL_COMMON (to)
2074 || (DECL_INITIAL (decl)
2075 && DECL_INITIAL (decl) != error_mark_node)))
2077 DECL_INITIAL (to) = targetm.emutls.var_init
2078 (to, decl, get_emutls_init_templ_addr (decl));
2080 /* Make sure the template is marked as needed early enough.
2081 Without this, if the variable is placed in a
2082 section-anchored block, the template will only be marked
2083 when it's too late. */
2084 record_references_in_initializer (to);
2087 decl = to;
2090 last_assemble_variable_decl = 0;
2092 /* Normally no need to say anything here for external references,
2093 since assemble_external is called by the language-specific code
2094 when a declaration is first seen. */
2096 if (DECL_EXTERNAL (decl))
2097 return;
2099 /* Output no assembler code for a function declaration.
2100 Only definitions of functions output anything. */
2102 if (TREE_CODE (decl) == FUNCTION_DECL)
2103 return;
2105 /* Do nothing for global register variables. */
2106 if (DECL_RTL_SET_P (decl) && REG_P (DECL_RTL (decl)))
2108 TREE_ASM_WRITTEN (decl) = 1;
2109 return;
2112 /* If type was incomplete when the variable was declared,
2113 see if it is complete now. */
2115 if (DECL_SIZE (decl) == 0)
2116 layout_decl (decl, 0);
2118 /* Still incomplete => don't allocate it; treat the tentative defn
2119 (which is what it must have been) as an `extern' reference. */
2121 if (!dont_output_data && DECL_SIZE (decl) == 0)
2123 error ("storage size of %q+D isn%'t known", decl);
2124 TREE_ASM_WRITTEN (decl) = 1;
2125 return;
2128 /* The first declaration of a variable that comes through this function
2129 decides whether it is global (in C, has external linkage)
2130 or local (in C, has internal linkage). So do nothing more
2131 if this function has already run. */
2133 if (TREE_ASM_WRITTEN (decl))
2134 return;
2136 /* Make sure targetm.encode_section_info is invoked before we set
2137 ASM_WRITTEN. */
2138 decl_rtl = DECL_RTL (decl);
2140 TREE_ASM_WRITTEN (decl) = 1;
2142 /* Do no output if -fsyntax-only. */
2143 if (flag_syntax_only)
2144 return;
2146 app_disable ();
2148 if (! dont_output_data
2149 && ! host_integerp (DECL_SIZE_UNIT (decl), 1))
2151 error ("size of variable %q+D is too large", decl);
2152 return;
2155 gcc_assert (MEM_P (decl_rtl));
2156 gcc_assert (GET_CODE (XEXP (decl_rtl, 0)) == SYMBOL_REF);
2157 symbol = XEXP (decl_rtl, 0);
2158 name = XSTR (symbol, 0);
2159 if (TREE_PUBLIC (decl) && DECL_NAME (decl))
2160 notice_global_symbol (decl);
2162 /* Compute the alignment of this data. */
2164 align_variable (decl, dont_output_data);
2165 set_mem_align (decl_rtl, DECL_ALIGN (decl));
2167 if (TREE_PUBLIC (decl))
2168 maybe_assemble_visibility (decl);
2170 if (DECL_PRESERVE_P (decl))
2171 targetm.asm_out.mark_decl_preserved (name);
2173 /* First make the assembler name(s) global if appropriate. */
2174 sect = get_variable_section (decl, false);
2175 if (TREE_PUBLIC (decl)
2176 && (sect->common.flags & SECTION_COMMON) == 0)
2177 globalize_decl (decl);
2179 /* Output any data that we will need to use the address of. */
2180 if (DECL_INITIAL (decl) && DECL_INITIAL (decl) != error_mark_node)
2181 output_addressed_constants (DECL_INITIAL (decl));
2183 /* dbxout.c needs to know this. */
2184 if (sect && (sect->common.flags & SECTION_CODE) != 0)
2185 DECL_IN_TEXT_SECTION (decl) = 1;
2187 /* If the decl is part of an object_block, make sure that the decl
2188 has been positioned within its block, but do not write out its
2189 definition yet. output_object_blocks will do that later. */
2190 if (SYMBOL_REF_HAS_BLOCK_INFO_P (symbol) && SYMBOL_REF_BLOCK (symbol))
2192 gcc_assert (!dont_output_data);
2193 place_block_symbol (symbol);
2195 else if (SECTION_STYLE (sect) == SECTION_NOSWITCH)
2196 assemble_noswitch_variable (decl, name, sect);
2197 else
2199 switch_to_section (sect);
2200 if (DECL_ALIGN (decl) > BITS_PER_UNIT)
2201 ASM_OUTPUT_ALIGN (asm_out_file, floor_log2 (DECL_ALIGN_UNIT (decl)));
2202 assemble_variable_contents (decl, name, dont_output_data);
2206 /* Return 1 if type TYPE contains any pointers. */
2208 static int
2209 contains_pointers_p (tree type)
2211 switch (TREE_CODE (type))
2213 case POINTER_TYPE:
2214 case REFERENCE_TYPE:
2215 /* I'm not sure whether OFFSET_TYPE needs this treatment,
2216 so I'll play safe and return 1. */
2217 case OFFSET_TYPE:
2218 return 1;
2220 case RECORD_TYPE:
2221 case UNION_TYPE:
2222 case QUAL_UNION_TYPE:
2224 tree fields;
2225 /* For a type that has fields, see if the fields have pointers. */
2226 for (fields = TYPE_FIELDS (type); fields; fields = TREE_CHAIN (fields))
2227 if (TREE_CODE (fields) == FIELD_DECL
2228 && contains_pointers_p (TREE_TYPE (fields)))
2229 return 1;
2230 return 0;
2233 case ARRAY_TYPE:
2234 /* An array type contains pointers if its element type does. */
2235 return contains_pointers_p (TREE_TYPE (type));
2237 default:
2238 return 0;
2242 /* We delay assemble_external processing until
2243 the compilation unit is finalized. This is the best we can do for
2244 right now (i.e. stage 3 of GCC 4.0) - the right thing is to delay
2245 it all the way to final. See PR 17982 for further discussion. */
2246 static GTY(()) tree pending_assemble_externals;
2248 #ifdef ASM_OUTPUT_EXTERNAL
2249 /* True if DECL is a function decl for which no out-of-line copy exists.
2250 It is assumed that DECL's assembler name has been set. */
2252 static bool
2253 incorporeal_function_p (tree decl)
2255 if (TREE_CODE (decl) == FUNCTION_DECL && DECL_BUILT_IN (decl))
2257 const char *name;
2259 if (DECL_BUILT_IN_CLASS (decl) == BUILT_IN_NORMAL
2260 && DECL_FUNCTION_CODE (decl) == BUILT_IN_ALLOCA)
2261 return true;
2263 name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
2264 if (is_builtin_name (name))
2265 return true;
2267 return false;
2270 /* Actually do the tests to determine if this is necessary, and invoke
2271 ASM_OUTPUT_EXTERNAL. */
2272 static void
2273 assemble_external_real (tree decl)
2275 rtx rtl = DECL_RTL (decl);
2277 if (MEM_P (rtl) && GET_CODE (XEXP (rtl, 0)) == SYMBOL_REF
2278 && !SYMBOL_REF_USED (XEXP (rtl, 0))
2279 && !incorporeal_function_p (decl))
2281 /* Some systems do require some output. */
2282 SYMBOL_REF_USED (XEXP (rtl, 0)) = 1;
2283 ASM_OUTPUT_EXTERNAL (asm_out_file, decl, XSTR (XEXP (rtl, 0), 0));
2286 #endif
2288 void
2289 process_pending_assemble_externals (void)
2291 #ifdef ASM_OUTPUT_EXTERNAL
2292 tree list;
2293 for (list = pending_assemble_externals; list; list = TREE_CHAIN (list))
2294 assemble_external_real (TREE_VALUE (list));
2296 pending_assemble_externals = 0;
2297 #endif
2300 /* This TREE_LIST contains any weak symbol declarations waiting
2301 to be emitted. */
2302 static GTY(()) tree weak_decls;
2304 /* Output something to declare an external symbol to the assembler,
2305 and qualifiers such as weakness. (Most assemblers don't need
2306 extern declaration, so we normally output nothing.) Do nothing if
2307 DECL is not external. */
2309 void
2310 assemble_external (tree decl ATTRIBUTE_UNUSED)
2312 /* Because most platforms do not define ASM_OUTPUT_EXTERNAL, the
2313 main body of this code is only rarely exercised. To provide some
2314 testing, on all platforms, we make sure that the ASM_OUT_FILE is
2315 open. If it's not, we should not be calling this function. */
2316 gcc_assert (asm_out_file);
2318 if (!DECL_P (decl) || !DECL_EXTERNAL (decl) || !TREE_PUBLIC (decl))
2319 return;
2321 /* We want to output annotation for weak and external symbols at
2322 very last to check if they are references or not. */
2324 if (SUPPORTS_WEAK && DECL_WEAK (decl)
2325 /* TREE_STATIC is a weird and abused creature which is not
2326 generally the right test for whether an entity has been
2327 locally emitted, inlined or otherwise not-really-extern, but
2328 for declarations that can be weak, it happens to be
2329 match. */
2330 && !TREE_STATIC (decl)
2331 && tree_find_value (weak_decls, decl) == NULL_TREE)
2332 weak_decls = tree_cons (NULL, decl, weak_decls);
2334 #ifdef ASM_OUTPUT_EXTERNAL
2335 if (tree_find_value (pending_assemble_externals, decl) == NULL_TREE)
2336 pending_assemble_externals = tree_cons (NULL, decl,
2337 pending_assemble_externals);
2338 #endif
2341 /* Similar, for calling a library function FUN. */
2343 void
2344 assemble_external_libcall (rtx fun)
2346 /* Declare library function name external when first used, if nec. */
2347 if (! SYMBOL_REF_USED (fun))
2349 SYMBOL_REF_USED (fun) = 1;
2350 targetm.asm_out.external_libcall (fun);
2354 /* Assemble a label named NAME. */
2356 void
2357 assemble_label (const char *name)
2359 ASM_OUTPUT_LABEL (asm_out_file, name);
2362 /* Set the symbol_referenced flag for ID. */
2363 void
2364 mark_referenced (tree id)
2366 TREE_SYMBOL_REFERENCED (id) = 1;
2369 /* Set the symbol_referenced flag for DECL and notify callgraph. */
2370 void
2371 mark_decl_referenced (tree decl)
2373 if (TREE_CODE (decl) == FUNCTION_DECL)
2375 /* Extern inline functions don't become needed when referenced.
2376 If we know a method will be emitted in other TU and no new
2377 functions can be marked reachable, just use the external
2378 definition. */
2379 struct cgraph_node *node = cgraph_node (decl);
2380 if (!DECL_EXTERNAL (decl)
2381 && (!node->local.vtable_method || !cgraph_global_info_ready
2382 || !node->local.finalized))
2383 cgraph_mark_needed_node (node);
2385 else if (TREE_CODE (decl) == VAR_DECL)
2387 struct varpool_node *node = varpool_node (decl);
2388 varpool_mark_needed_node (node);
2389 /* C++ frontend use mark_decl_references to force COMDAT variables
2390 to be output that might appear dead otherwise. */
2391 node->force_output = true;
2393 /* else do nothing - we can get various sorts of CST nodes here,
2394 which do not need to be marked. */
2398 /* Follow the IDENTIFIER_TRANSPARENT_ALIAS chain starting at *ALIAS
2399 until we find an identifier that is not itself a transparent alias.
2400 Modify the alias passed to it by reference (and all aliases on the
2401 way to the ultimate target), such that they do not have to be
2402 followed again, and return the ultimate target of the alias
2403 chain. */
2405 static inline tree
2406 ultimate_transparent_alias_target (tree *alias)
2408 tree target = *alias;
2410 if (IDENTIFIER_TRANSPARENT_ALIAS (target))
2412 gcc_assert (TREE_CHAIN (target));
2413 target = ultimate_transparent_alias_target (&TREE_CHAIN (target));
2414 gcc_assert (! IDENTIFIER_TRANSPARENT_ALIAS (target)
2415 && ! TREE_CHAIN (target));
2416 *alias = target;
2419 return target;
2422 /* Output to FILE (an assembly file) a reference to NAME. If NAME
2423 starts with a *, the rest of NAME is output verbatim. Otherwise
2424 NAME is transformed in a target-specific way (usually by the
2425 addition of an underscore). */
2427 void
2428 assemble_name_raw (FILE *file, const char *name)
2430 if (name[0] == '*')
2431 fputs (&name[1], file);
2432 else
2433 ASM_OUTPUT_LABELREF (file, name);
2436 /* Like assemble_name_raw, but should be used when NAME might refer to
2437 an entity that is also represented as a tree (like a function or
2438 variable). If NAME does refer to such an entity, that entity will
2439 be marked as referenced. */
2441 void
2442 assemble_name (FILE *file, const char *name)
2444 const char *real_name;
2445 tree id;
2447 real_name = targetm.strip_name_encoding (name);
2449 id = maybe_get_identifier (real_name);
2450 if (id)
2452 tree id_orig = id;
2454 mark_referenced (id);
2455 ultimate_transparent_alias_target (&id);
2456 if (id != id_orig)
2457 name = IDENTIFIER_POINTER (id);
2458 gcc_assert (! TREE_CHAIN (id));
2461 assemble_name_raw (file, name);
2464 /* Allocate SIZE bytes writable static space with a gensym name
2465 and return an RTX to refer to its address. */
2468 assemble_static_space (unsigned HOST_WIDE_INT size)
2470 char name[12];
2471 const char *namestring;
2472 rtx x;
2474 ASM_GENERATE_INTERNAL_LABEL (name, "LF", const_labelno);
2475 ++const_labelno;
2476 namestring = ggc_strdup (name);
2478 x = gen_rtx_SYMBOL_REF (Pmode, namestring);
2479 SYMBOL_REF_FLAGS (x) = SYMBOL_FLAG_LOCAL;
2481 #ifdef ASM_OUTPUT_ALIGNED_DECL_LOCAL
2482 ASM_OUTPUT_ALIGNED_DECL_LOCAL (asm_out_file, NULL_TREE, name, size,
2483 BIGGEST_ALIGNMENT);
2484 #else
2485 #ifdef ASM_OUTPUT_ALIGNED_LOCAL
2486 ASM_OUTPUT_ALIGNED_LOCAL (asm_out_file, name, size, BIGGEST_ALIGNMENT);
2487 #else
2489 /* Round size up to multiple of BIGGEST_ALIGNMENT bits
2490 so that each uninitialized object starts on such a boundary. */
2491 /* Variable `rounded' might or might not be used in ASM_OUTPUT_LOCAL. */
2492 unsigned HOST_WIDE_INT rounded ATTRIBUTE_UNUSED
2493 = ((size + (BIGGEST_ALIGNMENT / BITS_PER_UNIT) - 1)
2494 / (BIGGEST_ALIGNMENT / BITS_PER_UNIT)
2495 * (BIGGEST_ALIGNMENT / BITS_PER_UNIT));
2496 ASM_OUTPUT_LOCAL (asm_out_file, name, size, rounded);
2498 #endif
2499 #endif
2500 return x;
2503 /* Assemble the static constant template for function entry trampolines.
2504 This is done at most once per compilation.
2505 Returns an RTX for the address of the template. */
2507 static GTY(()) rtx initial_trampoline;
2509 #ifdef TRAMPOLINE_TEMPLATE
2511 assemble_trampoline_template (void)
2513 char label[256];
2514 const char *name;
2515 int align;
2516 rtx symbol;
2518 if (initial_trampoline)
2519 return initial_trampoline;
2521 /* By default, put trampoline templates in read-only data section. */
2523 #ifdef TRAMPOLINE_SECTION
2524 switch_to_section (TRAMPOLINE_SECTION);
2525 #else
2526 switch_to_section (readonly_data_section);
2527 #endif
2529 /* Write the assembler code to define one. */
2530 align = floor_log2 (TRAMPOLINE_ALIGNMENT / BITS_PER_UNIT);
2531 if (align > 0)
2533 ASM_OUTPUT_ALIGN (asm_out_file, align);
2536 targetm.asm_out.internal_label (asm_out_file, "LTRAMP", 0);
2537 TRAMPOLINE_TEMPLATE (asm_out_file);
2539 /* Record the rtl to refer to it. */
2540 ASM_GENERATE_INTERNAL_LABEL (label, "LTRAMP", 0);
2541 name = ggc_strdup (label);
2542 symbol = gen_rtx_SYMBOL_REF (Pmode, name);
2543 SYMBOL_REF_FLAGS (symbol) = SYMBOL_FLAG_LOCAL;
2545 initial_trampoline = gen_rtx_MEM (BLKmode, symbol);
2546 set_mem_align (initial_trampoline, TRAMPOLINE_ALIGNMENT);
2548 return initial_trampoline;
2550 #endif
2552 /* A and B are either alignments or offsets. Return the minimum alignment
2553 that may be assumed after adding the two together. */
2555 static inline unsigned
2556 min_align (unsigned int a, unsigned int b)
2558 return (a | b) & -(a | b);
2561 /* Return the assembler directive for creating a given kind of integer
2562 object. SIZE is the number of bytes in the object and ALIGNED_P
2563 indicates whether it is known to be aligned. Return NULL if the
2564 assembly dialect has no such directive.
2566 The returned string should be printed at the start of a new line and
2567 be followed immediately by the object's initial value. */
2569 const char *
2570 integer_asm_op (int size, int aligned_p)
2572 struct asm_int_op *ops;
2574 if (aligned_p)
2575 ops = &targetm.asm_out.aligned_op;
2576 else
2577 ops = &targetm.asm_out.unaligned_op;
2579 switch (size)
2581 case 1:
2582 return targetm.asm_out.byte_op;
2583 case 2:
2584 return ops->hi;
2585 case 4:
2586 return ops->si;
2587 case 8:
2588 return ops->di;
2589 case 16:
2590 return ops->ti;
2591 default:
2592 return NULL;
2596 /* Use directive OP to assemble an integer object X. Print OP at the
2597 start of the line, followed immediately by the value of X. */
2599 void
2600 assemble_integer_with_op (const char *op, rtx x)
2602 fputs (op, asm_out_file);
2603 output_addr_const (asm_out_file, x);
2604 fputc ('\n', asm_out_file);
2607 /* The default implementation of the asm_out.integer target hook. */
2609 bool
2610 default_assemble_integer (rtx x ATTRIBUTE_UNUSED,
2611 unsigned int size ATTRIBUTE_UNUSED,
2612 int aligned_p ATTRIBUTE_UNUSED)
2614 const char *op = integer_asm_op (size, aligned_p);
2615 /* Avoid GAS bugs for large values. Specifically negative values whose
2616 absolute value fits in a bfd_vma, but not in a bfd_signed_vma. */
2617 if (size > UNITS_PER_WORD && size > POINTER_SIZE / BITS_PER_UNIT)
2618 return false;
2619 return op && (assemble_integer_with_op (op, x), true);
2622 /* Assemble the integer constant X into an object of SIZE bytes. ALIGN is
2623 the alignment of the integer in bits. Return 1 if we were able to output
2624 the constant, otherwise 0. We must be able to output the constant,
2625 if FORCE is nonzero. */
2627 bool
2628 assemble_integer (rtx x, unsigned int size, unsigned int align, int force)
2630 int aligned_p;
2632 aligned_p = (align >= MIN (size * BITS_PER_UNIT, BIGGEST_ALIGNMENT));
2634 /* See if the target hook can handle this kind of object. */
2635 if (targetm.asm_out.integer (x, size, aligned_p))
2636 return true;
2638 /* If the object is a multi-byte one, try splitting it up. Split
2639 it into words it if is multi-word, otherwise split it into bytes. */
2640 if (size > 1)
2642 enum machine_mode omode, imode;
2643 unsigned int subalign;
2644 unsigned int subsize, i;
2645 enum mode_class mclass;
2647 subsize = size > UNITS_PER_WORD? UNITS_PER_WORD : 1;
2648 subalign = MIN (align, subsize * BITS_PER_UNIT);
2649 if (GET_CODE (x) == CONST_FIXED)
2650 mclass = GET_MODE_CLASS (GET_MODE (x));
2651 else
2652 mclass = MODE_INT;
2654 omode = mode_for_size (subsize * BITS_PER_UNIT, mclass, 0);
2655 imode = mode_for_size (size * BITS_PER_UNIT, mclass, 0);
2657 for (i = 0; i < size; i += subsize)
2659 rtx partial = simplify_subreg (omode, x, imode, i);
2660 if (!partial || !assemble_integer (partial, subsize, subalign, 0))
2661 break;
2663 if (i == size)
2664 return true;
2666 /* If we've printed some of it, but not all of it, there's no going
2667 back now. */
2668 gcc_assert (!i);
2671 gcc_assert (!force);
2673 return false;
2676 void
2677 assemble_real (REAL_VALUE_TYPE d, enum machine_mode mode, unsigned int align)
2679 long data[4] = {0, 0, 0, 0};
2680 int i;
2681 int bitsize, nelts, nunits, units_per;
2683 /* This is hairy. We have a quantity of known size. real_to_target
2684 will put it into an array of *host* longs, 32 bits per element
2685 (even if long is more than 32 bits). We need to determine the
2686 number of array elements that are occupied (nelts) and the number
2687 of *target* min-addressable units that will be occupied in the
2688 object file (nunits). We cannot assume that 32 divides the
2689 mode's bitsize (size * BITS_PER_UNIT) evenly.
2691 size * BITS_PER_UNIT is used here to make sure that padding bits
2692 (which might appear at either end of the value; real_to_target
2693 will include the padding bits in its output array) are included. */
2695 nunits = GET_MODE_SIZE (mode);
2696 bitsize = nunits * BITS_PER_UNIT;
2697 nelts = CEIL (bitsize, 32);
2698 units_per = 32 / BITS_PER_UNIT;
2700 real_to_target (data, &d, mode);
2702 /* Put out the first word with the specified alignment. */
2703 assemble_integer (GEN_INT (data[0]), MIN (nunits, units_per), align, 1);
2704 nunits -= units_per;
2706 /* Subsequent words need only 32-bit alignment. */
2707 align = min_align (align, 32);
2709 for (i = 1; i < nelts; i++)
2711 assemble_integer (GEN_INT (data[i]), MIN (nunits, units_per), align, 1);
2712 nunits -= units_per;
2716 /* Given an expression EXP with a constant value,
2717 reduce it to the sum of an assembler symbol and an integer.
2718 Store them both in the structure *VALUE.
2719 EXP must be reducible. */
2721 struct GTY(()) addr_const {
2722 rtx base;
2723 HOST_WIDE_INT offset;
2726 static void
2727 decode_addr_const (tree exp, struct addr_const *value)
2729 tree target = TREE_OPERAND (exp, 0);
2730 int offset = 0;
2731 rtx x;
2733 while (1)
2735 if (TREE_CODE (target) == COMPONENT_REF
2736 && host_integerp (byte_position (TREE_OPERAND (target, 1)), 0))
2739 offset += int_byte_position (TREE_OPERAND (target, 1));
2740 target = TREE_OPERAND (target, 0);
2742 else if (TREE_CODE (target) == ARRAY_REF
2743 || TREE_CODE (target) == ARRAY_RANGE_REF)
2745 offset += (tree_low_cst (TYPE_SIZE_UNIT (TREE_TYPE (target)), 1)
2746 * tree_low_cst (TREE_OPERAND (target, 1), 0));
2747 target = TREE_OPERAND (target, 0);
2749 else
2750 break;
2753 switch (TREE_CODE (target))
2755 case VAR_DECL:
2756 case FUNCTION_DECL:
2757 x = DECL_RTL (target);
2758 break;
2760 case LABEL_DECL:
2761 x = gen_rtx_MEM (FUNCTION_MODE,
2762 gen_rtx_LABEL_REF (Pmode, force_label_rtx (target)));
2763 break;
2765 case REAL_CST:
2766 case FIXED_CST:
2767 case STRING_CST:
2768 case COMPLEX_CST:
2769 case CONSTRUCTOR:
2770 case INTEGER_CST:
2771 x = output_constant_def (target, 1);
2772 break;
2774 default:
2775 gcc_unreachable ();
2778 gcc_assert (MEM_P (x));
2779 x = XEXP (x, 0);
2781 value->base = x;
2782 value->offset = offset;
2786 static GTY((param_is (struct constant_descriptor_tree)))
2787 htab_t const_desc_htab;
2789 static struct constant_descriptor_tree * build_constant_desc (tree);
2790 static void maybe_output_constant_def_contents (struct constant_descriptor_tree *, int);
2792 /* Constant pool accessor function. */
2794 htab_t
2795 constant_pool_htab (void)
2797 return const_desc_htab;
2800 /* Compute a hash code for a constant expression. */
2802 static hashval_t
2803 const_desc_hash (const void *ptr)
2805 return ((const struct constant_descriptor_tree *)ptr)->hash;
2808 static hashval_t
2809 const_hash_1 (const tree exp)
2811 const char *p;
2812 hashval_t hi;
2813 int len, i;
2814 enum tree_code code = TREE_CODE (exp);
2816 /* Either set P and LEN to the address and len of something to hash and
2817 exit the switch or return a value. */
2819 switch (code)
2821 case INTEGER_CST:
2822 p = (char *) &TREE_INT_CST (exp);
2823 len = sizeof TREE_INT_CST (exp);
2824 break;
2826 case REAL_CST:
2827 return real_hash (TREE_REAL_CST_PTR (exp));
2829 case FIXED_CST:
2830 return fixed_hash (TREE_FIXED_CST_PTR (exp));
2832 case STRING_CST:
2833 p = TREE_STRING_POINTER (exp);
2834 len = TREE_STRING_LENGTH (exp);
2835 break;
2837 case COMPLEX_CST:
2838 return (const_hash_1 (TREE_REALPART (exp)) * 5
2839 + const_hash_1 (TREE_IMAGPART (exp)));
2841 case CONSTRUCTOR:
2843 unsigned HOST_WIDE_INT idx;
2844 tree value;
2846 hi = 5 + int_size_in_bytes (TREE_TYPE (exp));
2848 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (exp), idx, value)
2849 if (value)
2850 hi = hi * 603 + const_hash_1 (value);
2852 return hi;
2855 case ADDR_EXPR:
2856 case FDESC_EXPR:
2858 struct addr_const value;
2860 decode_addr_const (exp, &value);
2861 switch (GET_CODE (value.base))
2863 case SYMBOL_REF:
2864 /* Don't hash the address of the SYMBOL_REF;
2865 only use the offset and the symbol name. */
2866 hi = value.offset;
2867 p = XSTR (value.base, 0);
2868 for (i = 0; p[i] != 0; i++)
2869 hi = ((hi * 613) + (unsigned) (p[i]));
2870 break;
2872 case LABEL_REF:
2873 hi = value.offset + CODE_LABEL_NUMBER (XEXP (value.base, 0)) * 13;
2874 break;
2876 default:
2877 gcc_unreachable ();
2880 return hi;
2882 case PLUS_EXPR:
2883 case POINTER_PLUS_EXPR:
2884 case MINUS_EXPR:
2885 return (const_hash_1 (TREE_OPERAND (exp, 0)) * 9
2886 + const_hash_1 (TREE_OPERAND (exp, 1)));
2888 CASE_CONVERT:
2889 return const_hash_1 (TREE_OPERAND (exp, 0)) * 7 + 2;
2891 default:
2892 /* A language specific constant. Just hash the code. */
2893 return code;
2896 /* Compute hashing function. */
2897 hi = len;
2898 for (i = 0; i < len; i++)
2899 hi = ((hi * 613) + (unsigned) (p[i]));
2901 return hi;
2904 /* Wrapper of compare_constant, for the htab interface. */
2905 static int
2906 const_desc_eq (const void *p1, const void *p2)
2908 const struct constant_descriptor_tree *const c1
2909 = (const struct constant_descriptor_tree *) p1;
2910 const struct constant_descriptor_tree *const c2
2911 = (const struct constant_descriptor_tree *) p2;
2912 if (c1->hash != c2->hash)
2913 return 0;
2914 return compare_constant (c1->value, c2->value);
2917 /* Compare t1 and t2, and return 1 only if they are known to result in
2918 the same bit pattern on output. */
2920 static int
2921 compare_constant (const tree t1, const tree t2)
2923 enum tree_code typecode;
2925 if (t1 == NULL_TREE)
2926 return t2 == NULL_TREE;
2927 if (t2 == NULL_TREE)
2928 return 0;
2930 if (TREE_CODE (t1) != TREE_CODE (t2))
2931 return 0;
2933 switch (TREE_CODE (t1))
2935 case INTEGER_CST:
2936 /* Integer constants are the same only if the same width of type. */
2937 if (TYPE_PRECISION (TREE_TYPE (t1)) != TYPE_PRECISION (TREE_TYPE (t2)))
2938 return 0;
2939 if (TYPE_MODE (TREE_TYPE (t1)) != TYPE_MODE (TREE_TYPE (t2)))
2940 return 0;
2941 return tree_int_cst_equal (t1, t2);
2943 case REAL_CST:
2944 /* Real constants are the same only if the same width of type. */
2945 if (TYPE_PRECISION (TREE_TYPE (t1)) != TYPE_PRECISION (TREE_TYPE (t2)))
2946 return 0;
2948 return REAL_VALUES_IDENTICAL (TREE_REAL_CST (t1), TREE_REAL_CST (t2));
2950 case FIXED_CST:
2951 /* Fixed constants are the same only if the same width of type. */
2952 if (TYPE_PRECISION (TREE_TYPE (t1)) != TYPE_PRECISION (TREE_TYPE (t2)))
2953 return 0;
2955 return FIXED_VALUES_IDENTICAL (TREE_FIXED_CST (t1), TREE_FIXED_CST (t2));
2957 case STRING_CST:
2958 if (TYPE_MODE (TREE_TYPE (t1)) != TYPE_MODE (TREE_TYPE (t2)))
2959 return 0;
2961 return (TREE_STRING_LENGTH (t1) == TREE_STRING_LENGTH (t2)
2962 && ! memcmp (TREE_STRING_POINTER (t1), TREE_STRING_POINTER (t2),
2963 TREE_STRING_LENGTH (t1)));
2965 case COMPLEX_CST:
2966 return (compare_constant (TREE_REALPART (t1), TREE_REALPART (t2))
2967 && compare_constant (TREE_IMAGPART (t1), TREE_IMAGPART (t2)));
2969 case CONSTRUCTOR:
2971 VEC(constructor_elt, gc) *v1, *v2;
2972 unsigned HOST_WIDE_INT idx;
2974 typecode = TREE_CODE (TREE_TYPE (t1));
2975 if (typecode != TREE_CODE (TREE_TYPE (t2)))
2976 return 0;
2978 if (typecode == ARRAY_TYPE)
2980 HOST_WIDE_INT size_1 = int_size_in_bytes (TREE_TYPE (t1));
2981 /* For arrays, check that the sizes all match. */
2982 if (TYPE_MODE (TREE_TYPE (t1)) != TYPE_MODE (TREE_TYPE (t2))
2983 || size_1 == -1
2984 || size_1 != int_size_in_bytes (TREE_TYPE (t2)))
2985 return 0;
2987 else
2989 /* For record and union constructors, require exact type
2990 equality. */
2991 if (TREE_TYPE (t1) != TREE_TYPE (t2))
2992 return 0;
2995 v1 = CONSTRUCTOR_ELTS (t1);
2996 v2 = CONSTRUCTOR_ELTS (t2);
2997 if (VEC_length (constructor_elt, v1)
2998 != VEC_length (constructor_elt, v2))
2999 return 0;
3001 for (idx = 0; idx < VEC_length (constructor_elt, v1); ++idx)
3003 constructor_elt *c1 = VEC_index (constructor_elt, v1, idx);
3004 constructor_elt *c2 = VEC_index (constructor_elt, v2, idx);
3006 /* Check that each value is the same... */
3007 if (!compare_constant (c1->value, c2->value))
3008 return 0;
3009 /* ... and that they apply to the same fields! */
3010 if (typecode == ARRAY_TYPE)
3012 if (!compare_constant (c1->index, c2->index))
3013 return 0;
3015 else
3017 if (c1->index != c2->index)
3018 return 0;
3022 return 1;
3025 case ADDR_EXPR:
3026 case FDESC_EXPR:
3028 struct addr_const value1, value2;
3030 decode_addr_const (t1, &value1);
3031 decode_addr_const (t2, &value2);
3032 return (value1.offset == value2.offset
3033 && strcmp (XSTR (value1.base, 0), XSTR (value2.base, 0)) == 0);
3036 case PLUS_EXPR:
3037 case POINTER_PLUS_EXPR:
3038 case MINUS_EXPR:
3039 case RANGE_EXPR:
3040 return (compare_constant (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0))
3041 && compare_constant(TREE_OPERAND (t1, 1), TREE_OPERAND (t2, 1)));
3043 CASE_CONVERT:
3044 case VIEW_CONVERT_EXPR:
3045 return compare_constant (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
3047 default:
3048 return 0;
3051 gcc_unreachable ();
3054 /* Make a copy of the whole tree structure for a constant. This
3055 handles the same types of nodes that compare_constant handles. */
3057 static tree
3058 copy_constant (tree exp)
3060 switch (TREE_CODE (exp))
3062 case ADDR_EXPR:
3063 /* For ADDR_EXPR, we do not want to copy the decl whose address
3064 is requested. We do want to copy constants though. */
3065 if (CONSTANT_CLASS_P (TREE_OPERAND (exp, 0)))
3066 return build1 (TREE_CODE (exp), TREE_TYPE (exp),
3067 copy_constant (TREE_OPERAND (exp, 0)));
3068 else
3069 return copy_node (exp);
3071 case INTEGER_CST:
3072 case REAL_CST:
3073 case FIXED_CST:
3074 case STRING_CST:
3075 return copy_node (exp);
3077 case COMPLEX_CST:
3078 return build_complex (TREE_TYPE (exp),
3079 copy_constant (TREE_REALPART (exp)),
3080 copy_constant (TREE_IMAGPART (exp)));
3082 case PLUS_EXPR:
3083 case POINTER_PLUS_EXPR:
3084 case MINUS_EXPR:
3085 return build2 (TREE_CODE (exp), TREE_TYPE (exp),
3086 copy_constant (TREE_OPERAND (exp, 0)),
3087 copy_constant (TREE_OPERAND (exp, 1)));
3089 CASE_CONVERT:
3090 case VIEW_CONVERT_EXPR:
3091 return build1 (TREE_CODE (exp), TREE_TYPE (exp),
3092 copy_constant (TREE_OPERAND (exp, 0)));
3094 case CONSTRUCTOR:
3096 tree copy = copy_node (exp);
3097 VEC(constructor_elt, gc) *v;
3098 unsigned HOST_WIDE_INT idx;
3099 tree purpose, value;
3101 v = VEC_alloc(constructor_elt, gc, VEC_length(constructor_elt,
3102 CONSTRUCTOR_ELTS (exp)));
3103 FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (exp), idx, purpose, value)
3105 constructor_elt *ce = VEC_quick_push (constructor_elt, v, NULL);
3106 ce->index = purpose;
3107 ce->value = copy_constant (value);
3109 CONSTRUCTOR_ELTS (copy) = v;
3110 return copy;
3113 default:
3114 gcc_unreachable ();
3118 /* Return the alignment of constant EXP in bits. */
3120 static unsigned int
3121 get_constant_alignment (tree exp)
3123 unsigned int align;
3125 align = TYPE_ALIGN (TREE_TYPE (exp));
3126 #ifdef CONSTANT_ALIGNMENT
3127 align = CONSTANT_ALIGNMENT (exp, align);
3128 #endif
3129 return align;
3132 /* Return the section into which constant EXP should be placed. */
3134 static section *
3135 get_constant_section (tree exp)
3137 if (IN_NAMED_SECTION (exp))
3138 return get_named_section (exp, NULL, compute_reloc_for_constant (exp));
3139 else
3140 return targetm.asm_out.select_section (exp,
3141 compute_reloc_for_constant (exp),
3142 get_constant_alignment (exp));
3145 /* Return the size of constant EXP in bytes. */
3147 static HOST_WIDE_INT
3148 get_constant_size (tree exp)
3150 HOST_WIDE_INT size;
3152 size = int_size_in_bytes (TREE_TYPE (exp));
3153 if (TREE_CODE (exp) == STRING_CST)
3154 size = MAX (TREE_STRING_LENGTH (exp), size);
3155 return size;
3158 /* Subroutine of output_constant_def:
3159 No constant equal to EXP is known to have been output.
3160 Make a constant descriptor to enter EXP in the hash table.
3161 Assign the label number and construct RTL to refer to the
3162 constant's location in memory.
3163 Caller is responsible for updating the hash table. */
3165 static struct constant_descriptor_tree *
3166 build_constant_desc (tree exp)
3168 rtx symbol;
3169 rtx rtl;
3170 char label[256];
3171 int labelno;
3172 struct constant_descriptor_tree *desc;
3174 desc = GGC_NEW (struct constant_descriptor_tree);
3175 desc->value = copy_constant (exp);
3177 /* Propagate marked-ness to copied constant. */
3178 if (flag_mudflap && mf_marked_p (exp))
3179 mf_mark (desc->value);
3181 /* Create a string containing the label name, in LABEL. */
3182 labelno = const_labelno++;
3183 ASM_GENERATE_INTERNAL_LABEL (label, "LC", labelno);
3185 /* We have a symbol name; construct the SYMBOL_REF and the MEM. */
3186 if (use_object_blocks_p ())
3188 section *sect = get_constant_section (exp);
3189 symbol = create_block_symbol (ggc_strdup (label),
3190 get_block_for_section (sect), -1);
3192 else
3193 symbol = gen_rtx_SYMBOL_REF (Pmode, ggc_strdup (label));
3194 SYMBOL_REF_FLAGS (symbol) |= SYMBOL_FLAG_LOCAL;
3195 SET_SYMBOL_REF_DECL (symbol, desc->value);
3196 TREE_CONSTANT_POOL_ADDRESS_P (symbol) = 1;
3198 rtl = gen_rtx_MEM (TYPE_MODE (TREE_TYPE (exp)), symbol);
3199 set_mem_attributes (rtl, exp, 1);
3200 set_mem_alias_set (rtl, 0);
3201 set_mem_alias_set (rtl, const_alias_set);
3203 /* We cannot share RTX'es in pool entries.
3204 Mark this piece of RTL as required for unsharing. */
3205 RTX_FLAG (rtl, used) = 1;
3207 /* Set flags or add text to the name to record information, such as
3208 that it is a local symbol. If the name is changed, the macro
3209 ASM_OUTPUT_LABELREF will have to know how to strip this
3210 information. This call might invalidate our local variable
3211 SYMBOL; we can't use it afterward. */
3213 targetm.encode_section_info (exp, rtl, true);
3215 desc->rtl = rtl;
3217 return desc;
3220 /* Return an rtx representing a reference to constant data in memory
3221 for the constant expression EXP.
3223 If assembler code for such a constant has already been output,
3224 return an rtx to refer to it.
3225 Otherwise, output such a constant in memory
3226 and generate an rtx for it.
3228 If DEFER is nonzero, this constant can be deferred and output only
3229 if referenced in the function after all optimizations.
3231 `const_desc_table' records which constants already have label strings. */
3234 output_constant_def (tree exp, int defer)
3236 struct constant_descriptor_tree *desc;
3237 struct constant_descriptor_tree key;
3238 void **loc;
3240 /* Look up EXP in the table of constant descriptors. If we didn't find
3241 it, create a new one. */
3242 key.value = exp;
3243 key.hash = const_hash_1 (exp);
3244 loc = htab_find_slot_with_hash (const_desc_htab, &key, key.hash, INSERT);
3246 desc = (struct constant_descriptor_tree *) *loc;
3247 if (desc == 0)
3249 desc = build_constant_desc (exp);
3250 desc->hash = key.hash;
3251 *loc = desc;
3254 maybe_output_constant_def_contents (desc, defer);
3255 return desc->rtl;
3258 /* Subroutine of output_constant_def: Decide whether or not we need to
3259 output the constant DESC now, and if so, do it. */
3260 static void
3261 maybe_output_constant_def_contents (struct constant_descriptor_tree *desc,
3262 int defer)
3264 rtx symbol = XEXP (desc->rtl, 0);
3265 tree exp = desc->value;
3267 if (flag_syntax_only)
3268 return;
3270 if (TREE_ASM_WRITTEN (exp))
3271 /* Already output; don't do it again. */
3272 return;
3274 /* We can always defer constants as long as the context allows
3275 doing so. */
3276 if (defer)
3278 /* Increment n_deferred_constants if it exists. It needs to be at
3279 least as large as the number of constants actually referred to
3280 by the function. If it's too small we'll stop looking too early
3281 and fail to emit constants; if it's too large we'll only look
3282 through the entire function when we could have stopped earlier. */
3283 if (cfun)
3284 n_deferred_constants++;
3285 return;
3288 output_constant_def_contents (symbol);
3291 /* Subroutine of output_constant_def_contents. Output the definition
3292 of constant EXP, which is pointed to by label LABEL. ALIGN is the
3293 constant's alignment in bits. */
3295 static void
3296 assemble_constant_contents (tree exp, const char *label, unsigned int align)
3298 HOST_WIDE_INT size;
3300 size = get_constant_size (exp);
3302 /* Do any machine/system dependent processing of the constant. */
3303 #ifdef ASM_DECLARE_CONSTANT_NAME
3304 ASM_DECLARE_CONSTANT_NAME (asm_out_file, label, exp, size);
3305 #else
3306 /* Standard thing is just output label for the constant. */
3307 ASM_OUTPUT_LABEL (asm_out_file, label);
3308 #endif /* ASM_DECLARE_CONSTANT_NAME */
3310 /* Output the value of EXP. */
3311 output_constant (exp, size, align);
3314 /* We must output the constant data referred to by SYMBOL; do so. */
3316 static void
3317 output_constant_def_contents (rtx symbol)
3319 tree exp = SYMBOL_REF_DECL (symbol);
3320 unsigned int align;
3322 /* Make sure any other constants whose addresses appear in EXP
3323 are assigned label numbers. */
3324 output_addressed_constants (exp);
3326 /* We are no longer deferring this constant. */
3327 TREE_ASM_WRITTEN (exp) = 1;
3329 /* If the constant is part of an object block, make sure that the
3330 decl has been positioned within its block, but do not write out
3331 its definition yet. output_object_blocks will do that later. */
3332 if (SYMBOL_REF_HAS_BLOCK_INFO_P (symbol) && SYMBOL_REF_BLOCK (symbol))
3333 place_block_symbol (symbol);
3334 else
3336 switch_to_section (get_constant_section (exp));
3337 align = get_constant_alignment (exp);
3338 if (align > BITS_PER_UNIT)
3339 ASM_OUTPUT_ALIGN (asm_out_file, floor_log2 (align / BITS_PER_UNIT));
3340 assemble_constant_contents (exp, XSTR (symbol, 0), align);
3342 if (flag_mudflap)
3343 mudflap_enqueue_constant (exp);
3346 /* Look up EXP in the table of constant descriptors. Return the rtl
3347 if it has been emitted, else null. */
3350 lookup_constant_def (tree exp)
3352 struct constant_descriptor_tree *desc;
3353 struct constant_descriptor_tree key;
3355 key.value = exp;
3356 key.hash = const_hash_1 (exp);
3357 desc = (struct constant_descriptor_tree *)
3358 htab_find_with_hash (const_desc_htab, &key, key.hash);
3360 return (desc ? desc->rtl : NULL_RTX);
3363 /* Used in the hash tables to avoid outputting the same constant
3364 twice. Unlike 'struct constant_descriptor_tree', RTX constants
3365 are output once per function, not once per file. */
3366 /* ??? Only a few targets need per-function constant pools. Most
3367 can use one per-file pool. Should add a targetm bit to tell the
3368 difference. */
3370 struct GTY(()) rtx_constant_pool {
3371 /* Pointers to first and last constant in pool, as ordered by offset. */
3372 struct constant_descriptor_rtx *first;
3373 struct constant_descriptor_rtx *last;
3375 /* Hash facility for making memory-constants from constant rtl-expressions.
3376 It is used on RISC machines where immediate integer arguments and
3377 constant addresses are restricted so that such constants must be stored
3378 in memory. */
3379 htab_t GTY((param_is (struct constant_descriptor_rtx))) const_rtx_htab;
3381 /* Current offset in constant pool (does not include any
3382 machine-specific header). */
3383 HOST_WIDE_INT offset;
3386 struct GTY((chain_next ("%h.next"))) constant_descriptor_rtx {
3387 struct constant_descriptor_rtx *next;
3388 rtx mem;
3389 rtx sym;
3390 rtx constant;
3391 HOST_WIDE_INT offset;
3392 hashval_t hash;
3393 enum machine_mode mode;
3394 unsigned int align;
3395 int labelno;
3396 int mark;
3399 /* Hash and compare functions for const_rtx_htab. */
3401 static hashval_t
3402 const_desc_rtx_hash (const void *ptr)
3404 const struct constant_descriptor_rtx *const desc
3405 = (const struct constant_descriptor_rtx *) ptr;
3406 return desc->hash;
3409 static int
3410 const_desc_rtx_eq (const void *a, const void *b)
3412 const struct constant_descriptor_rtx *const x
3413 = (const struct constant_descriptor_rtx *) a;
3414 const struct constant_descriptor_rtx *const y
3415 = (const struct constant_descriptor_rtx *) b;
3417 if (x->mode != y->mode)
3418 return 0;
3419 return rtx_equal_p (x->constant, y->constant);
3422 /* This is the worker function for const_rtx_hash, called via for_each_rtx. */
3424 static int
3425 const_rtx_hash_1 (rtx *xp, void *data)
3427 unsigned HOST_WIDE_INT hwi;
3428 enum machine_mode mode;
3429 enum rtx_code code;
3430 hashval_t h, *hp;
3431 rtx x;
3433 x = *xp;
3434 code = GET_CODE (x);
3435 mode = GET_MODE (x);
3436 h = (hashval_t) code * 1048573 + mode;
3438 switch (code)
3440 case CONST_INT:
3441 hwi = INTVAL (x);
3442 fold_hwi:
3444 int shift = sizeof (hashval_t) * CHAR_BIT;
3445 const int n = sizeof (HOST_WIDE_INT) / sizeof (hashval_t);
3446 int i;
3448 h ^= (hashval_t) hwi;
3449 for (i = 1; i < n; ++i)
3451 hwi >>= shift;
3452 h ^= (hashval_t) hwi;
3455 break;
3457 case CONST_DOUBLE:
3458 if (mode == VOIDmode)
3460 hwi = CONST_DOUBLE_LOW (x) ^ CONST_DOUBLE_HIGH (x);
3461 goto fold_hwi;
3463 else
3464 h ^= real_hash (CONST_DOUBLE_REAL_VALUE (x));
3465 break;
3467 case CONST_FIXED:
3468 h ^= fixed_hash (CONST_FIXED_VALUE (x));
3469 break;
3471 case CONST_VECTOR:
3473 int i;
3474 for (i = XVECLEN (x, 0); i-- > 0; )
3475 h = h * 251 + const_rtx_hash_1 (&XVECEXP (x, 0, i), data);
3477 break;
3479 case SYMBOL_REF:
3480 h ^= htab_hash_string (XSTR (x, 0));
3481 break;
3483 case LABEL_REF:
3484 h = h * 251 + CODE_LABEL_NUMBER (XEXP (x, 0));
3485 break;
3487 case UNSPEC:
3488 case UNSPEC_VOLATILE:
3489 h = h * 251 + XINT (x, 1);
3490 break;
3492 default:
3493 break;
3496 hp = (hashval_t *) data;
3497 *hp = *hp * 509 + h;
3498 return 0;
3501 /* Compute a hash value for X, which should be a constant. */
3503 static hashval_t
3504 const_rtx_hash (rtx x)
3506 hashval_t h = 0;
3507 for_each_rtx (&x, const_rtx_hash_1, &h);
3508 return h;
3512 /* Create and return a new rtx constant pool. */
3514 static struct rtx_constant_pool *
3515 create_constant_pool (void)
3517 struct rtx_constant_pool *pool;
3519 pool = GGC_NEW (struct rtx_constant_pool);
3520 pool->const_rtx_htab = htab_create_ggc (31, const_desc_rtx_hash,
3521 const_desc_rtx_eq, NULL);
3522 pool->first = NULL;
3523 pool->last = NULL;
3524 pool->offset = 0;
3525 return pool;
3528 /* Initialize constant pool hashing for a new function. */
3530 void
3531 init_varasm_status (void)
3533 crtl->varasm.pool = create_constant_pool ();
3534 crtl->varasm.deferred_constants = 0;
3537 /* Given a MINUS expression, simplify it if both sides
3538 include the same symbol. */
3541 simplify_subtraction (rtx x)
3543 rtx r = simplify_rtx (x);
3544 return r ? r : x;
3547 /* Given a constant rtx X, make (or find) a memory constant for its value
3548 and return a MEM rtx to refer to it in memory. */
3551 force_const_mem (enum machine_mode mode, rtx x)
3553 struct constant_descriptor_rtx *desc, tmp;
3554 struct rtx_constant_pool *pool;
3555 char label[256];
3556 rtx def, symbol;
3557 hashval_t hash;
3558 unsigned int align;
3559 void **slot;
3561 /* If we're not allowed to drop X into the constant pool, don't. */
3562 if (targetm.cannot_force_const_mem (x))
3563 return NULL_RTX;
3565 /* Record that this function has used a constant pool entry. */
3566 crtl->uses_const_pool = 1;
3568 /* Decide which pool to use. */
3569 pool = (targetm.use_blocks_for_constant_p (mode, x)
3570 ? shared_constant_pool
3571 : crtl->varasm.pool);
3573 /* Lookup the value in the hashtable. */
3574 tmp.constant = x;
3575 tmp.mode = mode;
3576 hash = const_rtx_hash (x);
3577 slot = htab_find_slot_with_hash (pool->const_rtx_htab, &tmp, hash, INSERT);
3578 desc = (struct constant_descriptor_rtx *) *slot;
3580 /* If the constant was already present, return its memory. */
3581 if (desc)
3582 return copy_rtx (desc->mem);
3584 /* Otherwise, create a new descriptor. */
3585 desc = GGC_NEW (struct constant_descriptor_rtx);
3586 *slot = desc;
3588 /* Align the location counter as required by EXP's data type. */
3589 align = GET_MODE_ALIGNMENT (mode == VOIDmode ? word_mode : mode);
3590 #ifdef CONSTANT_ALIGNMENT
3592 tree type = lang_hooks.types.type_for_mode (mode, 0);
3593 if (type != NULL_TREE)
3594 align = CONSTANT_ALIGNMENT (make_tree (type, x), align);
3596 #endif
3598 pool->offset += (align / BITS_PER_UNIT) - 1;
3599 pool->offset &= ~ ((align / BITS_PER_UNIT) - 1);
3601 desc->next = NULL;
3602 desc->constant = tmp.constant;
3603 desc->offset = pool->offset;
3604 desc->hash = hash;
3605 desc->mode = mode;
3606 desc->align = align;
3607 desc->labelno = const_labelno;
3608 desc->mark = 0;
3610 pool->offset += GET_MODE_SIZE (mode);
3611 if (pool->last)
3612 pool->last->next = desc;
3613 else
3614 pool->first = pool->last = desc;
3615 pool->last = desc;
3617 /* Create a string containing the label name, in LABEL. */
3618 ASM_GENERATE_INTERNAL_LABEL (label, "LC", const_labelno);
3619 ++const_labelno;
3621 /* Construct the SYMBOL_REF. Make sure to mark it as belonging to
3622 the constants pool. */
3623 if (use_object_blocks_p () && targetm.use_blocks_for_constant_p (mode, x))
3625 section *sect = targetm.asm_out.select_rtx_section (mode, x, align);
3626 symbol = create_block_symbol (ggc_strdup (label),
3627 get_block_for_section (sect), -1);
3629 else
3630 symbol = gen_rtx_SYMBOL_REF (Pmode, ggc_strdup (label));
3631 desc->sym = symbol;
3632 SYMBOL_REF_FLAGS (symbol) |= SYMBOL_FLAG_LOCAL;
3633 CONSTANT_POOL_ADDRESS_P (symbol) = 1;
3634 SET_SYMBOL_REF_CONSTANT (symbol, desc);
3636 /* Construct the MEM. */
3637 desc->mem = def = gen_const_mem (mode, symbol);
3638 set_mem_attributes (def, lang_hooks.types.type_for_mode (mode, 0), 1);
3639 set_mem_align (def, align);
3641 /* If we're dropping a label to the constant pool, make sure we
3642 don't delete it. */
3643 if (GET_CODE (x) == LABEL_REF)
3644 LABEL_PRESERVE_P (XEXP (x, 0)) = 1;
3646 return copy_rtx (def);
3649 /* Given a constant pool SYMBOL_REF, return the corresponding constant. */
3652 get_pool_constant (rtx addr)
3654 return SYMBOL_REF_CONSTANT (addr)->constant;
3657 /* Given a constant pool SYMBOL_REF, return the corresponding constant
3658 and whether it has been output or not. */
3661 get_pool_constant_mark (rtx addr, bool *pmarked)
3663 struct constant_descriptor_rtx *desc;
3665 desc = SYMBOL_REF_CONSTANT (addr);
3666 *pmarked = (desc->mark != 0);
3667 return desc->constant;
3670 /* Similar, return the mode. */
3672 enum machine_mode
3673 get_pool_mode (const_rtx addr)
3675 return SYMBOL_REF_CONSTANT (addr)->mode;
3678 /* Return the size of the constant pool. */
3681 get_pool_size (void)
3683 return crtl->varasm.pool->offset;
3686 /* Worker function for output_constant_pool_1. Emit assembly for X
3687 in MODE with known alignment ALIGN. */
3689 static void
3690 output_constant_pool_2 (enum machine_mode mode, rtx x, unsigned int align)
3692 switch (GET_MODE_CLASS (mode))
3694 case MODE_FLOAT:
3695 case MODE_DECIMAL_FLOAT:
3697 REAL_VALUE_TYPE r;
3699 gcc_assert (GET_CODE (x) == CONST_DOUBLE);
3700 REAL_VALUE_FROM_CONST_DOUBLE (r, x);
3701 assemble_real (r, mode, align);
3702 break;
3705 case MODE_INT:
3706 case MODE_PARTIAL_INT:
3707 case MODE_FRACT:
3708 case MODE_UFRACT:
3709 case MODE_ACCUM:
3710 case MODE_UACCUM:
3711 assemble_integer (x, GET_MODE_SIZE (mode), align, 1);
3712 break;
3714 case MODE_VECTOR_FLOAT:
3715 case MODE_VECTOR_INT:
3716 case MODE_VECTOR_FRACT:
3717 case MODE_VECTOR_UFRACT:
3718 case MODE_VECTOR_ACCUM:
3719 case MODE_VECTOR_UACCUM:
3721 int i, units;
3722 enum machine_mode submode = GET_MODE_INNER (mode);
3723 unsigned int subalign = MIN (align, GET_MODE_BITSIZE (submode));
3725 gcc_assert (GET_CODE (x) == CONST_VECTOR);
3726 units = CONST_VECTOR_NUNITS (x);
3728 for (i = 0; i < units; i++)
3730 rtx elt = CONST_VECTOR_ELT (x, i);
3731 output_constant_pool_2 (submode, elt, i ? subalign : align);
3734 break;
3736 default:
3737 gcc_unreachable ();
3741 /* Worker function for output_constant_pool. Emit constant DESC,
3742 giving it ALIGN bits of alignment. */
3744 static void
3745 output_constant_pool_1 (struct constant_descriptor_rtx *desc,
3746 unsigned int align)
3748 rtx x, tmp;
3750 x = desc->constant;
3752 /* See if X is a LABEL_REF (or a CONST referring to a LABEL_REF)
3753 whose CODE_LABEL has been deleted. This can occur if a jump table
3754 is eliminated by optimization. If so, write a constant of zero
3755 instead. Note that this can also happen by turning the
3756 CODE_LABEL into a NOTE. */
3757 /* ??? This seems completely and utterly wrong. Certainly it's
3758 not true for NOTE_INSN_DELETED_LABEL, but I disbelieve proper
3759 functioning even with INSN_DELETED_P and friends. */
3761 tmp = x;
3762 switch (GET_CODE (tmp))
3764 case CONST:
3765 if (GET_CODE (XEXP (tmp, 0)) != PLUS
3766 || GET_CODE (XEXP (XEXP (tmp, 0), 0)) != LABEL_REF)
3767 break;
3768 tmp = XEXP (XEXP (tmp, 0), 0);
3769 /* FALLTHRU */
3771 case LABEL_REF:
3772 tmp = XEXP (tmp, 0);
3773 gcc_assert (!INSN_DELETED_P (tmp));
3774 gcc_assert (!NOTE_P (tmp)
3775 || NOTE_KIND (tmp) != NOTE_INSN_DELETED);
3776 break;
3778 default:
3779 break;
3782 #ifdef ASM_OUTPUT_SPECIAL_POOL_ENTRY
3783 ASM_OUTPUT_SPECIAL_POOL_ENTRY (asm_out_file, x, desc->mode,
3784 align, desc->labelno, done);
3785 #endif
3787 assemble_align (align);
3789 /* Output the label. */
3790 targetm.asm_out.internal_label (asm_out_file, "LC", desc->labelno);
3792 /* Output the data. */
3793 output_constant_pool_2 (desc->mode, x, align);
3795 /* Make sure all constants in SECTION_MERGE and not SECTION_STRINGS
3796 sections have proper size. */
3797 if (align > GET_MODE_BITSIZE (desc->mode)
3798 && in_section
3799 && (in_section->common.flags & SECTION_MERGE))
3800 assemble_align (align);
3802 #ifdef ASM_OUTPUT_SPECIAL_POOL_ENTRY
3803 done:
3804 #endif
3805 return;
3808 /* Given a SYMBOL_REF CURRENT_RTX, mark it and all constants it refers
3809 to as used. Emit referenced deferred strings. This function can
3810 be used with for_each_rtx to mark all SYMBOL_REFs in an rtx. */
3812 static int
3813 mark_constant (rtx *current_rtx, void *data ATTRIBUTE_UNUSED)
3815 rtx x = *current_rtx;
3817 if (x == NULL_RTX || GET_CODE (x) != SYMBOL_REF)
3818 return 0;
3820 if (CONSTANT_POOL_ADDRESS_P (x))
3822 struct constant_descriptor_rtx *desc = SYMBOL_REF_CONSTANT (x);
3823 if (desc->mark == 0)
3825 desc->mark = 1;
3826 for_each_rtx (&desc->constant, mark_constant, NULL);
3829 else if (TREE_CONSTANT_POOL_ADDRESS_P (x))
3831 tree exp = SYMBOL_REF_DECL (x);
3832 if (!TREE_ASM_WRITTEN (exp))
3834 n_deferred_constants--;
3835 output_constant_def_contents (x);
3839 return -1;
3842 /* Look through appropriate parts of INSN, marking all entries in the
3843 constant pool which are actually being used. Entries that are only
3844 referenced by other constants are also marked as used. Emit
3845 deferred strings that are used. */
3847 static void
3848 mark_constants (rtx insn)
3850 if (!INSN_P (insn))
3851 return;
3853 /* Insns may appear inside a SEQUENCE. Only check the patterns of
3854 insns, not any notes that may be attached. We don't want to mark
3855 a constant just because it happens to appear in a REG_EQUIV note. */
3856 if (GET_CODE (PATTERN (insn)) == SEQUENCE)
3858 rtx seq = PATTERN (insn);
3859 int i, n = XVECLEN (seq, 0);
3860 for (i = 0; i < n; ++i)
3862 rtx subinsn = XVECEXP (seq, 0, i);
3863 if (INSN_P (subinsn))
3864 for_each_rtx (&PATTERN (subinsn), mark_constant, NULL);
3867 else
3868 for_each_rtx (&PATTERN (insn), mark_constant, NULL);
3871 /* Look through the instructions for this function, and mark all the
3872 entries in POOL which are actually being used. Emit deferred constants
3873 which have indeed been used. */
3875 static void
3876 mark_constant_pool (void)
3878 rtx insn, link;
3880 if (!crtl->uses_const_pool && n_deferred_constants == 0)
3881 return;
3883 for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
3884 mark_constants (insn);
3886 for (link = crtl->epilogue_delay_list;
3887 link;
3888 link = XEXP (link, 1))
3889 mark_constants (XEXP (link, 0));
3892 /* Write all the constants in POOL. */
3894 static void
3895 output_constant_pool_contents (struct rtx_constant_pool *pool)
3897 struct constant_descriptor_rtx *desc;
3899 for (desc = pool->first; desc ; desc = desc->next)
3900 if (desc->mark)
3902 /* If the constant is part of an object_block, make sure that
3903 the constant has been positioned within its block, but do not
3904 write out its definition yet. output_object_blocks will do
3905 that later. */
3906 if (SYMBOL_REF_HAS_BLOCK_INFO_P (desc->sym)
3907 && SYMBOL_REF_BLOCK (desc->sym))
3908 place_block_symbol (desc->sym);
3909 else
3911 switch_to_section (targetm.asm_out.select_rtx_section
3912 (desc->mode, desc->constant, desc->align));
3913 output_constant_pool_1 (desc, desc->align);
3918 /* Mark all constants that are used in the current function, then write
3919 out the function's private constant pool. */
3921 static void
3922 output_constant_pool (const char *fnname ATTRIBUTE_UNUSED,
3923 tree fndecl ATTRIBUTE_UNUSED)
3925 struct rtx_constant_pool *pool = crtl->varasm.pool;
3927 /* It is possible for gcc to call force_const_mem and then to later
3928 discard the instructions which refer to the constant. In such a
3929 case we do not need to output the constant. */
3930 mark_constant_pool ();
3932 #ifdef ASM_OUTPUT_POOL_PROLOGUE
3933 ASM_OUTPUT_POOL_PROLOGUE (asm_out_file, fnname, fndecl, pool->offset);
3934 #endif
3936 output_constant_pool_contents (pool);
3938 #ifdef ASM_OUTPUT_POOL_EPILOGUE
3939 ASM_OUTPUT_POOL_EPILOGUE (asm_out_file, fnname, fndecl, pool->offset);
3940 #endif
3943 /* Write the contents of the shared constant pool. */
3945 void
3946 output_shared_constant_pool (void)
3948 output_constant_pool_contents (shared_constant_pool);
3951 /* Determine what kind of relocations EXP may need. */
3954 compute_reloc_for_constant (tree exp)
3956 int reloc = 0, reloc2;
3957 tree tem;
3959 switch (TREE_CODE (exp))
3961 case ADDR_EXPR:
3962 case FDESC_EXPR:
3963 /* Go inside any operations that get_inner_reference can handle and see
3964 if what's inside is a constant: no need to do anything here for
3965 addresses of variables or functions. */
3966 for (tem = TREE_OPERAND (exp, 0); handled_component_p (tem);
3967 tem = TREE_OPERAND (tem, 0))
3970 if (TREE_PUBLIC (tem))
3971 reloc |= 2;
3972 else
3973 reloc |= 1;
3974 break;
3976 case PLUS_EXPR:
3977 case POINTER_PLUS_EXPR:
3978 reloc = compute_reloc_for_constant (TREE_OPERAND (exp, 0));
3979 reloc |= compute_reloc_for_constant (TREE_OPERAND (exp, 1));
3980 break;
3982 case MINUS_EXPR:
3983 reloc = compute_reloc_for_constant (TREE_OPERAND (exp, 0));
3984 reloc2 = compute_reloc_for_constant (TREE_OPERAND (exp, 1));
3985 /* The difference of two local labels is computable at link time. */
3986 if (reloc == 1 && reloc2 == 1)
3987 reloc = 0;
3988 else
3989 reloc |= reloc2;
3990 break;
3992 CASE_CONVERT:
3993 case VIEW_CONVERT_EXPR:
3994 reloc = compute_reloc_for_constant (TREE_OPERAND (exp, 0));
3995 break;
3997 case CONSTRUCTOR:
3999 unsigned HOST_WIDE_INT idx;
4000 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (exp), idx, tem)
4001 if (tem != 0)
4002 reloc |= compute_reloc_for_constant (tem);
4004 break;
4006 default:
4007 break;
4009 return reloc;
4012 /* Find all the constants whose addresses are referenced inside of EXP,
4013 and make sure assembler code with a label has been output for each one.
4014 Indicate whether an ADDR_EXPR has been encountered. */
4016 static void
4017 output_addressed_constants (tree exp)
4019 tree tem;
4021 switch (TREE_CODE (exp))
4023 case ADDR_EXPR:
4024 case FDESC_EXPR:
4025 /* Go inside any operations that get_inner_reference can handle and see
4026 if what's inside is a constant: no need to do anything here for
4027 addresses of variables or functions. */
4028 for (tem = TREE_OPERAND (exp, 0); handled_component_p (tem);
4029 tem = TREE_OPERAND (tem, 0))
4032 /* If we have an initialized CONST_DECL, retrieve the initializer. */
4033 if (TREE_CODE (tem) == CONST_DECL && DECL_INITIAL (tem))
4034 tem = DECL_INITIAL (tem);
4036 if (CONSTANT_CLASS_P (tem) || TREE_CODE (tem) == CONSTRUCTOR)
4037 output_constant_def (tem, 0);
4038 break;
4040 case PLUS_EXPR:
4041 case POINTER_PLUS_EXPR:
4042 case MINUS_EXPR:
4043 output_addressed_constants (TREE_OPERAND (exp, 1));
4044 /* Fall through. */
4046 CASE_CONVERT:
4047 case VIEW_CONVERT_EXPR:
4048 output_addressed_constants (TREE_OPERAND (exp, 0));
4049 break;
4051 case CONSTRUCTOR:
4053 unsigned HOST_WIDE_INT idx;
4054 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (exp), idx, tem)
4055 if (tem != 0)
4056 output_addressed_constants (tem);
4058 break;
4060 default:
4061 break;
4065 /* Whether a constructor CTOR is a valid static constant initializer if all
4066 its elements are. This used to be internal to initializer_constant_valid_p
4067 and has been exposed to let other functions like categorize_ctor_elements
4068 evaluate the property while walking a constructor for other purposes. */
4070 bool
4071 constructor_static_from_elts_p (const_tree ctor)
4073 return (TREE_CONSTANT (ctor)
4074 && (TREE_CODE (TREE_TYPE (ctor)) == UNION_TYPE
4075 || TREE_CODE (TREE_TYPE (ctor)) == RECORD_TYPE)
4076 && !VEC_empty (constructor_elt, CONSTRUCTOR_ELTS (ctor)));
4079 /* A subroutine of initializer_constant_valid_p. VALUE is a MINUS_EXPR,
4080 PLUS_EXPR or POINTER_PLUS_EXPR. This looks for cases of VALUE
4081 which are valid when ENDTYPE is an integer of any size; in
4082 particular, this does not accept a pointer minus a constant. This
4083 returns null_pointer_node if the VALUE is an absolute constant
4084 which can be used to initialize a static variable. Otherwise it
4085 returns NULL. */
4087 static tree
4088 narrowing_initializer_constant_valid_p (tree value, tree endtype)
4090 tree op0, op1;
4092 if (!INTEGRAL_TYPE_P (endtype))
4093 return NULL_TREE;
4095 op0 = TREE_OPERAND (value, 0);
4096 op1 = TREE_OPERAND (value, 1);
4098 /* Like STRIP_NOPS except allow the operand mode to widen. This
4099 works around a feature of fold that simplifies (int)(p1 - p2) to
4100 ((int)p1 - (int)p2) under the theory that the narrower operation
4101 is cheaper. */
4103 while (CONVERT_EXPR_P (op0)
4104 || TREE_CODE (op0) == NON_LVALUE_EXPR)
4106 tree inner = TREE_OPERAND (op0, 0);
4107 if (inner == error_mark_node
4108 || ! INTEGRAL_MODE_P (TYPE_MODE (TREE_TYPE (inner)))
4109 || (GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op0)))
4110 > GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (inner)))))
4111 break;
4112 op0 = inner;
4115 while (CONVERT_EXPR_P (op1)
4116 || TREE_CODE (op1) == NON_LVALUE_EXPR)
4118 tree inner = TREE_OPERAND (op1, 0);
4119 if (inner == error_mark_node
4120 || ! INTEGRAL_MODE_P (TYPE_MODE (TREE_TYPE (inner)))
4121 || (GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op1)))
4122 > GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (inner)))))
4123 break;
4124 op1 = inner;
4127 op0 = initializer_constant_valid_p (op0, endtype);
4128 op1 = initializer_constant_valid_p (op1, endtype);
4130 /* Both initializers must be known. */
4131 if (op0 && op1)
4133 if (op0 == op1
4134 && (op0 == null_pointer_node
4135 || TREE_CODE (value) == MINUS_EXPR))
4136 return null_pointer_node;
4138 /* Support differences between labels. */
4139 if (TREE_CODE (op0) == LABEL_DECL
4140 && TREE_CODE (op1) == LABEL_DECL)
4141 return null_pointer_node;
4143 if (TREE_CODE (op0) == STRING_CST
4144 && TREE_CODE (op1) == STRING_CST
4145 && operand_equal_p (op0, op1, 1))
4146 return null_pointer_node;
4149 return NULL_TREE;
4152 /* Return nonzero if VALUE is a valid constant-valued expression
4153 for use in initializing a static variable; one that can be an
4154 element of a "constant" initializer.
4156 Return null_pointer_node if the value is absolute;
4157 if it is relocatable, return the variable that determines the relocation.
4158 We assume that VALUE has been folded as much as possible;
4159 therefore, we do not need to check for such things as
4160 arithmetic-combinations of integers. */
4162 tree
4163 initializer_constant_valid_p (tree value, tree endtype)
4165 tree ret;
4167 switch (TREE_CODE (value))
4169 case CONSTRUCTOR:
4170 if (constructor_static_from_elts_p (value))
4172 unsigned HOST_WIDE_INT idx;
4173 tree elt;
4174 bool absolute = true;
4176 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (value), idx, elt)
4178 tree reloc;
4179 reloc = initializer_constant_valid_p (elt, TREE_TYPE (elt));
4180 if (!reloc)
4181 return NULL_TREE;
4182 if (reloc != null_pointer_node)
4183 absolute = false;
4185 /* For a non-absolute relocation, there is no single
4186 variable that can be "the variable that determines the
4187 relocation." */
4188 return absolute ? null_pointer_node : error_mark_node;
4191 return TREE_STATIC (value) ? null_pointer_node : NULL_TREE;
4193 case INTEGER_CST:
4194 case VECTOR_CST:
4195 case REAL_CST:
4196 case FIXED_CST:
4197 case STRING_CST:
4198 case COMPLEX_CST:
4199 return null_pointer_node;
4201 case ADDR_EXPR:
4202 case FDESC_EXPR:
4204 tree op0 = staticp (TREE_OPERAND (value, 0));
4205 if (op0)
4207 /* "&(*a).f" is like unto pointer arithmetic. If "a" turns out
4208 to be a constant, this is old-skool offsetof-like nonsense. */
4209 if (TREE_CODE (op0) == INDIRECT_REF
4210 && TREE_CONSTANT (TREE_OPERAND (op0, 0)))
4211 return null_pointer_node;
4212 /* Taking the address of a nested function involves a trampoline,
4213 unless we don't need or want one. */
4214 if (TREE_CODE (op0) == FUNCTION_DECL
4215 && decl_function_context (op0)
4216 && !DECL_NO_STATIC_CHAIN (op0)
4217 && !TREE_NO_TRAMPOLINE (value))
4218 return NULL_TREE;
4219 /* "&{...}" requires a temporary to hold the constructed
4220 object. */
4221 if (TREE_CODE (op0) == CONSTRUCTOR)
4222 return NULL_TREE;
4224 return op0;
4227 case NON_LVALUE_EXPR:
4228 return initializer_constant_valid_p (TREE_OPERAND (value, 0), endtype);
4230 case VIEW_CONVERT_EXPR:
4232 tree src = TREE_OPERAND (value, 0);
4233 tree src_type = TREE_TYPE (src);
4234 tree dest_type = TREE_TYPE (value);
4236 /* Allow view-conversions from aggregate to non-aggregate type only
4237 if the bit pattern is fully preserved afterwards; otherwise, the
4238 RTL expander won't be able to apply a subsequent transformation
4239 to the underlying constructor. */
4240 if (AGGREGATE_TYPE_P (src_type) && !AGGREGATE_TYPE_P (dest_type))
4242 if (TYPE_MODE (endtype) == TYPE_MODE (dest_type))
4243 return initializer_constant_valid_p (src, endtype);
4244 else
4245 return NULL_TREE;
4248 /* Allow all other kinds of view-conversion. */
4249 return initializer_constant_valid_p (src, endtype);
4252 CASE_CONVERT:
4254 tree src = TREE_OPERAND (value, 0);
4255 tree src_type = TREE_TYPE (src);
4256 tree dest_type = TREE_TYPE (value);
4258 /* Allow conversions between pointer types, floating-point
4259 types, and offset types. */
4260 if ((POINTER_TYPE_P (dest_type) && POINTER_TYPE_P (src_type))
4261 || (FLOAT_TYPE_P (dest_type) && FLOAT_TYPE_P (src_type))
4262 || (TREE_CODE (dest_type) == OFFSET_TYPE
4263 && TREE_CODE (src_type) == OFFSET_TYPE))
4264 return initializer_constant_valid_p (src, endtype);
4266 /* Allow length-preserving conversions between integer types. */
4267 if (INTEGRAL_TYPE_P (dest_type) && INTEGRAL_TYPE_P (src_type)
4268 && (TYPE_PRECISION (dest_type) == TYPE_PRECISION (src_type)))
4269 return initializer_constant_valid_p (src, endtype);
4271 /* Allow conversions between other integer types only if
4272 explicit value. */
4273 if (INTEGRAL_TYPE_P (dest_type) && INTEGRAL_TYPE_P (src_type))
4275 tree inner = initializer_constant_valid_p (src, endtype);
4276 if (inner == null_pointer_node)
4277 return null_pointer_node;
4278 break;
4281 /* Allow (int) &foo provided int is as wide as a pointer. */
4282 if (INTEGRAL_TYPE_P (dest_type) && POINTER_TYPE_P (src_type)
4283 && (TYPE_PRECISION (dest_type) >= TYPE_PRECISION (src_type)))
4284 return initializer_constant_valid_p (src, endtype);
4286 /* Likewise conversions from int to pointers, but also allow
4287 conversions from 0. */
4288 if ((POINTER_TYPE_P (dest_type)
4289 || TREE_CODE (dest_type) == OFFSET_TYPE)
4290 && INTEGRAL_TYPE_P (src_type))
4292 if (TREE_CODE (src) == INTEGER_CST
4293 && TYPE_PRECISION (dest_type) >= TYPE_PRECISION (src_type))
4294 return null_pointer_node;
4295 if (integer_zerop (src))
4296 return null_pointer_node;
4297 else if (TYPE_PRECISION (dest_type) <= TYPE_PRECISION (src_type))
4298 return initializer_constant_valid_p (src, endtype);
4301 /* Allow conversions to struct or union types if the value
4302 inside is okay. */
4303 if (TREE_CODE (dest_type) == RECORD_TYPE
4304 || TREE_CODE (dest_type) == UNION_TYPE)
4305 return initializer_constant_valid_p (src, endtype);
4307 break;
4309 case POINTER_PLUS_EXPR:
4310 case PLUS_EXPR:
4311 if (! INTEGRAL_TYPE_P (endtype)
4312 || TYPE_PRECISION (endtype) >= POINTER_SIZE)
4314 tree valid0 = initializer_constant_valid_p (TREE_OPERAND (value, 0),
4315 endtype);
4316 tree valid1 = initializer_constant_valid_p (TREE_OPERAND (value, 1),
4317 endtype);
4318 /* If either term is absolute, use the other term's relocation. */
4319 if (valid0 == null_pointer_node)
4320 return valid1;
4321 if (valid1 == null_pointer_node)
4322 return valid0;
4325 /* Support narrowing pointer differences. */
4326 ret = narrowing_initializer_constant_valid_p (value, endtype);
4327 if (ret != NULL_TREE)
4328 return ret;
4330 break;
4332 case MINUS_EXPR:
4333 if (! INTEGRAL_TYPE_P (endtype)
4334 || TYPE_PRECISION (endtype) >= POINTER_SIZE)
4336 tree valid0 = initializer_constant_valid_p (TREE_OPERAND (value, 0),
4337 endtype);
4338 tree valid1 = initializer_constant_valid_p (TREE_OPERAND (value, 1),
4339 endtype);
4340 /* Win if second argument is absolute. */
4341 if (valid1 == null_pointer_node)
4342 return valid0;
4343 /* Win if both arguments have the same relocation.
4344 Then the value is absolute. */
4345 if (valid0 == valid1 && valid0 != 0)
4346 return null_pointer_node;
4348 /* Since GCC guarantees that string constants are unique in the
4349 generated code, a subtraction between two copies of the same
4350 constant string is absolute. */
4351 if (valid0 && TREE_CODE (valid0) == STRING_CST
4352 && valid1 && TREE_CODE (valid1) == STRING_CST
4353 && operand_equal_p (valid0, valid1, 1))
4354 return null_pointer_node;
4357 /* Support narrowing differences. */
4358 ret = narrowing_initializer_constant_valid_p (value, endtype);
4359 if (ret != NULL_TREE)
4360 return ret;
4362 break;
4364 default:
4365 break;
4368 return 0;
4371 /* Return true if VALUE is a valid constant-valued expression
4372 for use in initializing a static bit-field; one that can be
4373 an element of a "constant" initializer. */
4375 bool
4376 initializer_constant_valid_for_bitfield_p (tree value)
4378 /* For bitfields we support integer constants or possibly nested aggregates
4379 of such. */
4380 switch (TREE_CODE (value))
4382 case CONSTRUCTOR:
4384 unsigned HOST_WIDE_INT idx;
4385 tree elt;
4387 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (value), idx, elt)
4388 if (!initializer_constant_valid_for_bitfield_p (elt))
4389 return false;
4390 return true;
4393 case INTEGER_CST:
4394 return true;
4396 case VIEW_CONVERT_EXPR:
4397 case NON_LVALUE_EXPR:
4398 return
4399 initializer_constant_valid_for_bitfield_p (TREE_OPERAND (value, 0));
4401 default:
4402 break;
4405 return false;
4408 /* output_constructor outer state of relevance in recursive calls, typically
4409 for nested aggregate bitfields. */
4411 typedef struct {
4412 unsigned int bit_offset; /* current position in ... */
4413 int byte; /* ... the outer byte buffer. */
4414 } oc_outer_state;
4416 static unsigned HOST_WIDE_INT
4417 output_constructor (tree, unsigned HOST_WIDE_INT, unsigned int,
4418 oc_outer_state *);
4420 /* Output assembler code for constant EXP to FILE, with no label.
4421 This includes the pseudo-op such as ".int" or ".byte", and a newline.
4422 Assumes output_addressed_constants has been done on EXP already.
4424 Generate exactly SIZE bytes of assembler data, padding at the end
4425 with zeros if necessary. SIZE must always be specified.
4427 SIZE is important for structure constructors,
4428 since trailing members may have been omitted from the constructor.
4429 It is also important for initialization of arrays from string constants
4430 since the full length of the string constant might not be wanted.
4431 It is also needed for initialization of unions, where the initializer's
4432 type is just one member, and that may not be as long as the union.
4434 There a case in which we would fail to output exactly SIZE bytes:
4435 for a structure constructor that wants to produce more than SIZE bytes.
4436 But such constructors will never be generated for any possible input.
4438 ALIGN is the alignment of the data in bits. */
4440 void
4441 output_constant (tree exp, unsigned HOST_WIDE_INT size, unsigned int align)
4443 enum tree_code code;
4444 unsigned HOST_WIDE_INT thissize;
4446 if (size == 0 || flag_syntax_only)
4447 return;
4449 /* See if we're trying to initialize a pointer in a non-default mode
4450 to the address of some declaration somewhere. If the target says
4451 the mode is valid for pointers, assume the target has a way of
4452 resolving it. */
4453 if (TREE_CODE (exp) == NOP_EXPR
4454 && POINTER_TYPE_P (TREE_TYPE (exp))
4455 && targetm.valid_pointer_mode (TYPE_MODE (TREE_TYPE (exp))))
4457 tree saved_type = TREE_TYPE (exp);
4459 /* Peel off any intermediate conversions-to-pointer for valid
4460 pointer modes. */
4461 while (TREE_CODE (exp) == NOP_EXPR
4462 && POINTER_TYPE_P (TREE_TYPE (exp))
4463 && targetm.valid_pointer_mode (TYPE_MODE (TREE_TYPE (exp))))
4464 exp = TREE_OPERAND (exp, 0);
4466 /* If what we're left with is the address of something, we can
4467 convert the address to the final type and output it that
4468 way. */
4469 if (TREE_CODE (exp) == ADDR_EXPR)
4470 exp = build1 (ADDR_EXPR, saved_type, TREE_OPERAND (exp, 0));
4471 /* Likewise for constant ints. */
4472 else if (TREE_CODE (exp) == INTEGER_CST)
4473 exp = build_int_cst_wide (saved_type, TREE_INT_CST_LOW (exp),
4474 TREE_INT_CST_HIGH (exp));
4478 /* Eliminate any conversions since we'll be outputting the underlying
4479 constant. */
4480 while (CONVERT_EXPR_P (exp)
4481 || TREE_CODE (exp) == NON_LVALUE_EXPR
4482 || TREE_CODE (exp) == VIEW_CONVERT_EXPR)
4484 HOST_WIDE_INT type_size = int_size_in_bytes (TREE_TYPE (exp));
4485 HOST_WIDE_INT op_size = int_size_in_bytes (TREE_TYPE (TREE_OPERAND (exp, 0)));
4487 /* Make sure eliminating the conversion is really a no-op, except with
4488 VIEW_CONVERT_EXPRs to allow for wild Ada unchecked conversions and
4489 union types to allow for Ada unchecked unions. */
4490 if (type_size > op_size
4491 && TREE_CODE (exp) != VIEW_CONVERT_EXPR
4492 && TREE_CODE (TREE_TYPE (exp)) != UNION_TYPE)
4493 /* Keep the conversion. */
4494 break;
4495 else
4496 exp = TREE_OPERAND (exp, 0);
4499 code = TREE_CODE (TREE_TYPE (exp));
4500 thissize = int_size_in_bytes (TREE_TYPE (exp));
4502 /* Allow a constructor with no elements for any data type.
4503 This means to fill the space with zeros. */
4504 if (TREE_CODE (exp) == CONSTRUCTOR
4505 && VEC_empty (constructor_elt, CONSTRUCTOR_ELTS (exp)))
4507 assemble_zeros (size);
4508 return;
4511 if (TREE_CODE (exp) == FDESC_EXPR)
4513 #ifdef ASM_OUTPUT_FDESC
4514 HOST_WIDE_INT part = tree_low_cst (TREE_OPERAND (exp, 1), 0);
4515 tree decl = TREE_OPERAND (exp, 0);
4516 ASM_OUTPUT_FDESC (asm_out_file, decl, part);
4517 #else
4518 gcc_unreachable ();
4519 #endif
4520 return;
4523 /* Now output the underlying data. If we've handling the padding, return.
4524 Otherwise, break and ensure SIZE is the size written. */
4525 switch (code)
4527 case BOOLEAN_TYPE:
4528 case INTEGER_TYPE:
4529 case ENUMERAL_TYPE:
4530 case POINTER_TYPE:
4531 case REFERENCE_TYPE:
4532 case OFFSET_TYPE:
4533 case FIXED_POINT_TYPE:
4534 if (! assemble_integer (expand_expr (exp, NULL_RTX, VOIDmode,
4535 EXPAND_INITIALIZER),
4536 MIN (size, thissize), align, 0))
4537 error ("initializer for integer/fixed-point value is too complicated");
4538 break;
4540 case REAL_TYPE:
4541 if (TREE_CODE (exp) != REAL_CST)
4542 error ("initializer for floating value is not a floating constant");
4544 assemble_real (TREE_REAL_CST (exp), TYPE_MODE (TREE_TYPE (exp)), align);
4545 break;
4547 case COMPLEX_TYPE:
4548 output_constant (TREE_REALPART (exp), thissize / 2, align);
4549 output_constant (TREE_IMAGPART (exp), thissize / 2,
4550 min_align (align, BITS_PER_UNIT * (thissize / 2)));
4551 break;
4553 case ARRAY_TYPE:
4554 case VECTOR_TYPE:
4555 switch (TREE_CODE (exp))
4557 case CONSTRUCTOR:
4558 output_constructor (exp, size, align, NULL);
4559 return;
4560 case STRING_CST:
4561 thissize = MIN ((unsigned HOST_WIDE_INT)TREE_STRING_LENGTH (exp),
4562 size);
4563 assemble_string (TREE_STRING_POINTER (exp), thissize);
4564 break;
4566 case VECTOR_CST:
4568 int elt_size;
4569 tree link;
4570 unsigned int nalign;
4571 enum machine_mode inner;
4573 inner = TYPE_MODE (TREE_TYPE (TREE_TYPE (exp)));
4574 nalign = MIN (align, GET_MODE_ALIGNMENT (inner));
4576 elt_size = GET_MODE_SIZE (inner);
4578 link = TREE_VECTOR_CST_ELTS (exp);
4579 output_constant (TREE_VALUE (link), elt_size, align);
4580 thissize = elt_size;
4581 while ((link = TREE_CHAIN (link)) != NULL)
4583 output_constant (TREE_VALUE (link), elt_size, nalign);
4584 thissize += elt_size;
4586 break;
4588 default:
4589 gcc_unreachable ();
4591 break;
4593 case RECORD_TYPE:
4594 case UNION_TYPE:
4595 gcc_assert (TREE_CODE (exp) == CONSTRUCTOR);
4596 output_constructor (exp, size, align, NULL);
4597 return;
4599 case ERROR_MARK:
4600 return;
4602 default:
4603 gcc_unreachable ();
4606 if (size > thissize)
4607 assemble_zeros (size - thissize);
4611 /* Subroutine of output_constructor, used for computing the size of
4612 arrays of unspecified length. VAL must be a CONSTRUCTOR of an array
4613 type with an unspecified upper bound. */
4615 static unsigned HOST_WIDE_INT
4616 array_size_for_constructor (tree val)
4618 tree max_index, i;
4619 unsigned HOST_WIDE_INT cnt;
4620 tree index, value, tmp;
4622 /* This code used to attempt to handle string constants that are not
4623 arrays of single-bytes, but nothing else does, so there's no point in
4624 doing it here. */
4625 if (TREE_CODE (val) == STRING_CST)
4626 return TREE_STRING_LENGTH (val);
4628 max_index = NULL_TREE;
4629 FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (val), cnt, index, value)
4631 if (TREE_CODE (index) == RANGE_EXPR)
4632 index = TREE_OPERAND (index, 1);
4633 if (max_index == NULL_TREE || tree_int_cst_lt (max_index, index))
4634 max_index = index;
4637 if (max_index == NULL_TREE)
4638 return 0;
4640 /* Compute the total number of array elements. */
4641 tmp = TYPE_MIN_VALUE (TYPE_DOMAIN (TREE_TYPE (val)));
4642 i = size_binop (MINUS_EXPR, fold_convert (sizetype, max_index),
4643 fold_convert (sizetype, tmp));
4644 i = size_binop (PLUS_EXPR, i, build_int_cst (sizetype, 1));
4646 /* Multiply by the array element unit size to find number of bytes. */
4647 i = size_binop (MULT_EXPR, i, TYPE_SIZE_UNIT (TREE_TYPE (TREE_TYPE (val))));
4649 return tree_low_cst (i, 1);
4652 /* Other datastructures + helpers for output_constructor. */
4654 /* output_constructor local state to support interaction with helpers. */
4656 typedef struct {
4658 /* Received arguments. */
4659 tree exp; /* Constructor expression. */
4660 unsigned HOST_WIDE_INT size; /* # bytes to output - pad if necessary. */
4661 unsigned int align; /* Known initial alignment. */
4663 /* Constructor expression data. */
4664 tree type; /* Expression type. */
4665 tree field; /* Current field decl in a record. */
4666 tree min_index; /* Lower bound if specified for an array. */
4668 /* Output processing state. */
4669 HOST_WIDE_INT total_bytes; /* # bytes output so far / current position. */
4670 bool byte_buffer_in_use; /* Whether byte ... */
4671 int byte; /* ... contains part of a bitfield byte yet to
4672 be output. */
4674 int last_relative_index; /* Implicit or explicit index of the last
4675 array element output within a bitfield. */
4676 /* Current element. */
4677 tree val; /* Current element value. */
4678 tree index; /* Current element index. */
4680 } oc_local_state;
4682 /* Helper for output_constructor. From the current LOCAL state, output a
4683 RANGE_EXPR element. */
4685 static void
4686 output_constructor_array_range (oc_local_state *local)
4688 unsigned HOST_WIDE_INT fieldsize
4689 = int_size_in_bytes (TREE_TYPE (local->type));
4691 HOST_WIDE_INT lo_index
4692 = tree_low_cst (TREE_OPERAND (local->index, 0), 0);
4693 HOST_WIDE_INT hi_index
4694 = tree_low_cst (TREE_OPERAND (local->index, 1), 0);
4695 HOST_WIDE_INT index;
4697 unsigned int align2
4698 = min_align (local->align, fieldsize * BITS_PER_UNIT);
4700 for (index = lo_index; index <= hi_index; index++)
4702 /* Output the element's initial value. */
4703 if (local->val == NULL_TREE)
4704 assemble_zeros (fieldsize);
4705 else
4706 output_constant (local->val, fieldsize, align2);
4708 /* Count its size. */
4709 local->total_bytes += fieldsize;
4713 /* Helper for output_constructor. From the current LOCAL state, output a
4714 field element that is not true bitfield or part of an outer one. */
4716 static void
4717 output_constructor_regular_field (oc_local_state *local)
4719 /* Field size and position. Since this structure is static, we know the
4720 positions are constant. */
4721 unsigned HOST_WIDE_INT fieldsize;
4722 HOST_WIDE_INT fieldpos;
4724 unsigned int align2;
4726 if (local->index != NULL_TREE)
4727 fieldpos = (tree_low_cst (TYPE_SIZE_UNIT (TREE_TYPE (local->val)), 1)
4728 * ((tree_low_cst (local->index, 0)
4729 - tree_low_cst (local->min_index, 0))));
4730 else if (local->field != NULL_TREE)
4731 fieldpos = int_byte_position (local->field);
4732 else
4733 fieldpos = 0;
4735 /* Output any buffered-up bit-fields preceding this element. */
4736 if (local->byte_buffer_in_use)
4738 assemble_integer (GEN_INT (local->byte), 1, BITS_PER_UNIT, 1);
4739 local->total_bytes++;
4740 local->byte_buffer_in_use = false;
4743 /* Advance to offset of this element.
4744 Note no alignment needed in an array, since that is guaranteed
4745 if each element has the proper size. */
4746 if ((local->field != NULL_TREE || local->index != NULL_TREE)
4747 && fieldpos != local->total_bytes)
4749 gcc_assert (fieldpos >= local->total_bytes);
4750 assemble_zeros (fieldpos - local->total_bytes);
4751 local->total_bytes = fieldpos;
4754 /* Find the alignment of this element. */
4755 align2 = min_align (local->align, BITS_PER_UNIT * fieldpos);
4757 /* Determine size this element should occupy. */
4758 if (local->field)
4760 fieldsize = 0;
4762 /* If this is an array with an unspecified upper bound,
4763 the initializer determines the size. */
4764 /* ??? This ought to only checked if DECL_SIZE_UNIT is NULL,
4765 but we cannot do this until the deprecated support for
4766 initializing zero-length array members is removed. */
4767 if (TREE_CODE (TREE_TYPE (local->field)) == ARRAY_TYPE
4768 && TYPE_DOMAIN (TREE_TYPE (local->field))
4769 && ! TYPE_MAX_VALUE (TYPE_DOMAIN (TREE_TYPE (local->field))))
4771 fieldsize = array_size_for_constructor (local->val);
4772 /* Given a non-empty initialization, this field had
4773 better be last. */
4774 gcc_assert (!fieldsize || !TREE_CHAIN (local->field));
4776 else if (DECL_SIZE_UNIT (local->field))
4778 /* ??? This can't be right. If the decl size overflows
4779 a host integer we will silently emit no data. */
4780 if (host_integerp (DECL_SIZE_UNIT (local->field), 1))
4781 fieldsize = tree_low_cst (DECL_SIZE_UNIT (local->field), 1);
4784 else
4785 fieldsize = int_size_in_bytes (TREE_TYPE (local->type));
4787 /* Output the element's initial value. */
4788 if (local->val == NULL_TREE)
4789 assemble_zeros (fieldsize);
4790 else
4791 output_constant (local->val, fieldsize, align2);
4793 /* Count its size. */
4794 local->total_bytes += fieldsize;
4797 /* Helper for output_constructor. From the current LOCAL and OUTER states,
4798 output an element that is a true bitfield or part of an outer one. */
4800 static void
4801 output_constructor_bitfield (oc_local_state *local, oc_outer_state *outer)
4803 /* Bit size of this element. */
4804 HOST_WIDE_INT ebitsize
4805 = (local->field
4806 ? tree_low_cst (DECL_SIZE (local->field), 1)
4807 : tree_low_cst (TYPE_SIZE (TREE_TYPE (local->type)), 1));
4809 /* Relative index of this element if this is an array component. */
4810 HOST_WIDE_INT relative_index
4811 = (!local->field
4812 ? (local->index
4813 ? (tree_low_cst (local->index, 0)
4814 - tree_low_cst (local->min_index, 0))
4815 : local->last_relative_index + 1)
4816 : 0);
4818 /* Bit position of this element from the start of the containing
4819 constructor. */
4820 HOST_WIDE_INT constructor_relative_ebitpos
4821 = (local->field
4822 ? int_bit_position (local->field)
4823 : ebitsize * relative_index);
4825 /* Bit position of this element from the start of a possibly ongoing
4826 outer byte buffer. */
4827 HOST_WIDE_INT byte_relative_ebitpos
4828 = ((outer ? outer->bit_offset : 0) + constructor_relative_ebitpos);
4830 /* From the start of a possibly ongoing outer byte buffer, offsets to
4831 the first bit of this element and to the first bit past the end of
4832 this element. */
4833 HOST_WIDE_INT next_offset = byte_relative_ebitpos;
4834 HOST_WIDE_INT end_offset = byte_relative_ebitpos + ebitsize;
4836 local->last_relative_index = relative_index;
4838 if (local->val == NULL_TREE)
4839 local->val = integer_zero_node;
4841 while (TREE_CODE (local->val) == VIEW_CONVERT_EXPR
4842 || TREE_CODE (local->val) == NON_LVALUE_EXPR)
4843 local->val = TREE_OPERAND (local->val, 0);
4845 if (TREE_CODE (local->val) != INTEGER_CST
4846 && TREE_CODE (local->val) != CONSTRUCTOR)
4848 error ("invalid initial value for member %qE", DECL_NAME (local->field));
4849 return;
4852 /* If this field does not start in this (or, next) byte,
4853 skip some bytes. */
4854 if (next_offset / BITS_PER_UNIT != local->total_bytes)
4856 /* Output remnant of any bit field in previous bytes. */
4857 if (local->byte_buffer_in_use)
4859 assemble_integer (GEN_INT (local->byte), 1, BITS_PER_UNIT, 1);
4860 local->total_bytes++;
4861 local->byte_buffer_in_use = false;
4864 /* If still not at proper byte, advance to there. */
4865 if (next_offset / BITS_PER_UNIT != local->total_bytes)
4867 gcc_assert (next_offset / BITS_PER_UNIT >= local->total_bytes);
4868 assemble_zeros (next_offset / BITS_PER_UNIT - local->total_bytes);
4869 local->total_bytes = next_offset / BITS_PER_UNIT;
4873 /* Set up the buffer if necessary. */
4874 if (!local->byte_buffer_in_use)
4876 local->byte = 0;
4877 if (ebitsize > 0)
4878 local->byte_buffer_in_use = true;
4881 /* If this is nested constructor, recurse passing the bit offset and the
4882 pending data, then retrieve the new pending data afterwards. */
4883 if (TREE_CODE (local->val) == CONSTRUCTOR)
4885 oc_outer_state output_state;
4887 output_state.bit_offset = next_offset % BITS_PER_UNIT;
4888 output_state.byte = local->byte;
4889 local->total_bytes
4890 += output_constructor (local->val, 0, 0, &output_state);
4891 local->byte = output_state.byte;
4892 return;
4895 /* Otherwise, we must split the element into pieces that fall within
4896 separate bytes, and combine each byte with previous or following
4897 bit-fields. */
4898 while (next_offset < end_offset)
4900 int this_time;
4901 int shift;
4902 HOST_WIDE_INT value;
4903 HOST_WIDE_INT next_byte = next_offset / BITS_PER_UNIT;
4904 HOST_WIDE_INT next_bit = next_offset % BITS_PER_UNIT;
4906 /* Advance from byte to byte
4907 within this element when necessary. */
4908 while (next_byte != local->total_bytes)
4910 assemble_integer (GEN_INT (local->byte), 1, BITS_PER_UNIT, 1);
4911 local->total_bytes++;
4912 local->byte = 0;
4915 /* Number of bits we can process at once
4916 (all part of the same byte). */
4917 this_time = MIN (end_offset - next_offset,
4918 BITS_PER_UNIT - next_bit);
4919 if (BYTES_BIG_ENDIAN)
4921 /* On big-endian machine, take the most significant bits
4922 first (of the bits that are significant)
4923 and put them into bytes from the most significant end. */
4924 shift = end_offset - next_offset - this_time;
4926 /* Don't try to take a bunch of bits that cross
4927 the word boundary in the INTEGER_CST. We can
4928 only select bits from the LOW or HIGH part
4929 not from both. */
4930 if (shift < HOST_BITS_PER_WIDE_INT
4931 && shift + this_time > HOST_BITS_PER_WIDE_INT)
4933 this_time = shift + this_time - HOST_BITS_PER_WIDE_INT;
4934 shift = HOST_BITS_PER_WIDE_INT;
4937 /* Now get the bits from the appropriate constant word. */
4938 if (shift < HOST_BITS_PER_WIDE_INT)
4939 value = TREE_INT_CST_LOW (local->val);
4940 else
4942 gcc_assert (shift < 2 * HOST_BITS_PER_WIDE_INT);
4943 value = TREE_INT_CST_HIGH (local->val);
4944 shift -= HOST_BITS_PER_WIDE_INT;
4947 /* Get the result. This works only when:
4948 1 <= this_time <= HOST_BITS_PER_WIDE_INT. */
4949 local->byte |= (((value >> shift)
4950 & (((HOST_WIDE_INT) 2 << (this_time - 1)) - 1))
4951 << (BITS_PER_UNIT - this_time - next_bit));
4953 else
4955 /* On little-endian machines,
4956 take first the least significant bits of the value
4957 and pack them starting at the least significant
4958 bits of the bytes. */
4959 shift = next_offset - byte_relative_ebitpos;
4961 /* Don't try to take a bunch of bits that cross
4962 the word boundary in the INTEGER_CST. We can
4963 only select bits from the LOW or HIGH part
4964 not from both. */
4965 if (shift < HOST_BITS_PER_WIDE_INT
4966 && shift + this_time > HOST_BITS_PER_WIDE_INT)
4967 this_time = (HOST_BITS_PER_WIDE_INT - shift);
4969 /* Now get the bits from the appropriate constant word. */
4970 if (shift < HOST_BITS_PER_WIDE_INT)
4971 value = TREE_INT_CST_LOW (local->val);
4972 else
4974 gcc_assert (shift < 2 * HOST_BITS_PER_WIDE_INT);
4975 value = TREE_INT_CST_HIGH (local->val);
4976 shift -= HOST_BITS_PER_WIDE_INT;
4979 /* Get the result. This works only when:
4980 1 <= this_time <= HOST_BITS_PER_WIDE_INT. */
4981 local->byte |= (((value >> shift)
4982 & (((HOST_WIDE_INT) 2 << (this_time - 1)) - 1))
4983 << next_bit);
4986 next_offset += this_time;
4987 local->byte_buffer_in_use = true;
4991 /* Subroutine of output_constant, used for CONSTRUCTORs (aggregate constants).
4992 Generate at least SIZE bytes, padding if necessary. OUTER designates the
4993 caller output state of relevance in recursive invocations. */
4995 static unsigned HOST_WIDE_INT
4996 output_constructor (tree exp, unsigned HOST_WIDE_INT size,
4997 unsigned int align, oc_outer_state * outer)
4999 unsigned HOST_WIDE_INT cnt;
5000 constructor_elt *ce;
5002 oc_local_state local;
5004 /* Setup our local state to communicate with helpers. */
5005 local.exp = exp;
5006 local.size = size;
5007 local.align = align;
5009 local.total_bytes = 0;
5010 local.byte_buffer_in_use = outer != NULL;
5011 local.byte = outer ? outer->byte : 0;
5013 local.type = TREE_TYPE (exp);
5015 local.last_relative_index = -1;
5017 local.min_index = NULL_TREE;
5018 if (TREE_CODE (local.type) == ARRAY_TYPE
5019 && TYPE_DOMAIN (local.type) != NULL_TREE)
5020 local.min_index = TYPE_MIN_VALUE (TYPE_DOMAIN (local.type));
5022 gcc_assert (HOST_BITS_PER_WIDE_INT >= BITS_PER_UNIT);
5024 /* As CE goes through the elements of the constant, FIELD goes through the
5025 structure fields if the constant is a structure. If the constant is a
5026 union, we override this by getting the field from the TREE_LIST element.
5027 But the constant could also be an array. Then FIELD is zero.
5029 There is always a maximum of one element in the chain LINK for unions
5030 (even if the initializer in a source program incorrectly contains
5031 more one). */
5033 local.field = NULL_TREE;
5034 if (TREE_CODE (local.type) == RECORD_TYPE)
5035 local.field = TYPE_FIELDS (local.type);
5037 for (cnt = 0;
5038 VEC_iterate (constructor_elt, CONSTRUCTOR_ELTS (exp), cnt, ce);
5039 cnt++, local.field = local.field ? TREE_CHAIN (local.field) : 0)
5041 local.val = ce->value;
5042 local.index = NULL_TREE;
5044 /* The element in a union constructor specifies the proper field
5045 or index. */
5046 if ((TREE_CODE (local.type) == RECORD_TYPE
5047 || TREE_CODE (local.type) == UNION_TYPE
5048 || TREE_CODE (local.type) == QUAL_UNION_TYPE)
5049 && ce->index != NULL_TREE)
5050 local.field = ce->index;
5052 else if (TREE_CODE (local.type) == ARRAY_TYPE)
5053 local.index = ce->index;
5055 #ifdef ASM_COMMENT_START
5056 if (local.field && flag_verbose_asm)
5057 fprintf (asm_out_file, "%s %s:\n",
5058 ASM_COMMENT_START,
5059 DECL_NAME (local.field)
5060 ? IDENTIFIER_POINTER (DECL_NAME (local.field))
5061 : "<anonymous>");
5062 #endif
5064 /* Eliminate the marker that makes a cast not be an lvalue. */
5065 if (local.val != NULL_TREE)
5066 STRIP_NOPS (local.val);
5068 /* Output the current element, using the appropriate helper ... */
5070 /* For an array slice not part of an outer bitfield. */
5071 if (!outer
5072 && local.index != NULL_TREE
5073 && TREE_CODE (local.index) == RANGE_EXPR)
5074 output_constructor_array_range (&local);
5076 /* For a field that is neither a true bitfield nor part of an outer one,
5077 known to be at least byte aligned and multiple-of-bytes long. */
5078 else if (!outer
5079 && (local.field == NULL_TREE
5080 || !CONSTRUCTOR_BITFIELD_P (local.field)))
5081 output_constructor_regular_field (&local);
5083 /* For a true bitfield or part of an outer one. */
5084 else
5085 output_constructor_bitfield (&local, outer);
5088 /* If we are not at toplevel, save the pending data for our caller.
5089 Otherwise output the pending data and padding zeros as needed. */
5090 if (outer)
5091 outer->byte = local.byte;
5092 else
5094 if (local.byte_buffer_in_use)
5096 assemble_integer (GEN_INT (local.byte), 1, BITS_PER_UNIT, 1);
5097 local.total_bytes++;
5100 if ((unsigned HOST_WIDE_INT)local.total_bytes < local.size)
5102 assemble_zeros (local.size - local.total_bytes);
5103 local.total_bytes = local.size;
5107 return local.total_bytes;
5110 /* Mark DECL as weak. */
5112 static void
5113 mark_weak (tree decl)
5115 DECL_WEAK (decl) = 1;
5117 if (DECL_RTL_SET_P (decl)
5118 && MEM_P (DECL_RTL (decl))
5119 && XEXP (DECL_RTL (decl), 0)
5120 && GET_CODE (XEXP (DECL_RTL (decl), 0)) == SYMBOL_REF)
5121 SYMBOL_REF_WEAK (XEXP (DECL_RTL (decl), 0)) = 1;
5124 /* Merge weak status between NEWDECL and OLDDECL. */
5126 void
5127 merge_weak (tree newdecl, tree olddecl)
5129 if (DECL_WEAK (newdecl) == DECL_WEAK (olddecl))
5131 if (DECL_WEAK (newdecl) && SUPPORTS_WEAK)
5133 tree *pwd;
5134 /* We put the NEWDECL on the weak_decls list at some point
5135 and OLDDECL as well. Keep just OLDDECL on the list. */
5136 for (pwd = &weak_decls; *pwd; pwd = &TREE_CHAIN (*pwd))
5137 if (TREE_VALUE (*pwd) == newdecl)
5139 *pwd = TREE_CHAIN (*pwd);
5140 break;
5143 return;
5146 if (DECL_WEAK (newdecl))
5148 tree wd;
5150 /* NEWDECL is weak, but OLDDECL is not. */
5152 /* If we already output the OLDDECL, we're in trouble; we can't
5153 go back and make it weak. This error cannot be caught in
5154 declare_weak because the NEWDECL and OLDDECL was not yet
5155 been merged; therefore, TREE_ASM_WRITTEN was not set. */
5156 if (TREE_ASM_WRITTEN (olddecl))
5157 error ("weak declaration of %q+D must precede definition",
5158 newdecl);
5160 /* If we've already generated rtl referencing OLDDECL, we may
5161 have done so in a way that will not function properly with
5162 a weak symbol. */
5163 else if (TREE_USED (olddecl)
5164 && TREE_SYMBOL_REFERENCED (DECL_ASSEMBLER_NAME (olddecl)))
5165 warning (0, "weak declaration of %q+D after first use results "
5166 "in unspecified behavior", newdecl);
5168 if (SUPPORTS_WEAK)
5170 /* We put the NEWDECL on the weak_decls list at some point.
5171 Replace it with the OLDDECL. */
5172 for (wd = weak_decls; wd; wd = TREE_CHAIN (wd))
5173 if (TREE_VALUE (wd) == newdecl)
5175 TREE_VALUE (wd) = olddecl;
5176 break;
5178 /* We may not find the entry on the list. If NEWDECL is a
5179 weak alias, then we will have already called
5180 globalize_decl to remove the entry; in that case, we do
5181 not need to do anything. */
5184 /* Make the OLDDECL weak; it's OLDDECL that we'll be keeping. */
5185 mark_weak (olddecl);
5187 else
5188 /* OLDDECL was weak, but NEWDECL was not explicitly marked as
5189 weak. Just update NEWDECL to indicate that it's weak too. */
5190 mark_weak (newdecl);
5193 /* Declare DECL to be a weak symbol. */
5195 void
5196 declare_weak (tree decl)
5198 if (! TREE_PUBLIC (decl))
5199 error ("weak declaration of %q+D must be public", decl);
5200 else if (TREE_CODE (decl) == FUNCTION_DECL && TREE_ASM_WRITTEN (decl))
5201 error ("weak declaration of %q+D must precede definition", decl);
5202 else if (!SUPPORTS_WEAK)
5203 warning (0, "weak declaration of %q+D not supported", decl);
5205 mark_weak (decl);
5208 static void
5209 weak_finish_1 (tree decl)
5211 #if defined (ASM_WEAKEN_DECL) || defined (ASM_WEAKEN_LABEL)
5212 const char *const name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
5213 #endif
5215 if (! TREE_USED (decl))
5216 return;
5218 #ifdef ASM_WEAKEN_DECL
5219 ASM_WEAKEN_DECL (asm_out_file, decl, name, NULL);
5220 #else
5221 #ifdef ASM_WEAKEN_LABEL
5222 ASM_WEAKEN_LABEL (asm_out_file, name);
5223 #else
5224 #ifdef ASM_OUTPUT_WEAK_ALIAS
5226 static bool warn_once = 0;
5227 if (! warn_once)
5229 warning (0, "only weak aliases are supported in this configuration");
5230 warn_once = 1;
5232 return;
5234 #endif
5235 #endif
5236 #endif
5239 /* This TREE_LIST contains weakref targets. */
5241 static GTY(()) tree weakref_targets;
5243 /* Forward declaration. */
5244 static tree find_decl_and_mark_needed (tree decl, tree target);
5246 /* Emit any pending weak declarations. */
5248 void
5249 weak_finish (void)
5251 tree t;
5253 for (t = weakref_targets; t; t = TREE_CHAIN (t))
5255 tree alias_decl = TREE_PURPOSE (t);
5256 tree target = ultimate_transparent_alias_target (&TREE_VALUE (t));
5258 if (! TREE_SYMBOL_REFERENCED (DECL_ASSEMBLER_NAME (alias_decl)))
5259 /* Remove alias_decl from the weak list, but leave entries for
5260 the target alone. */
5261 target = NULL_TREE;
5262 #ifndef ASM_OUTPUT_WEAKREF
5263 else if (! TREE_SYMBOL_REFERENCED (target))
5265 /* Use ASM_WEAKEN_LABEL only if ASM_WEAKEN_DECL is not
5266 defined, otherwise we and weak_finish_1 would use
5267 different macros. */
5268 # if defined ASM_WEAKEN_LABEL && ! defined ASM_WEAKEN_DECL
5269 ASM_WEAKEN_LABEL (asm_out_file, IDENTIFIER_POINTER (target));
5270 # else
5271 tree decl = find_decl_and_mark_needed (alias_decl, target);
5273 if (! decl)
5275 decl = build_decl (DECL_SOURCE_LOCATION (alias_decl),
5276 TREE_CODE (alias_decl), target,
5277 TREE_TYPE (alias_decl));
5279 DECL_EXTERNAL (decl) = 1;
5280 TREE_PUBLIC (decl) = 1;
5281 DECL_ARTIFICIAL (decl) = 1;
5282 TREE_NOTHROW (decl) = TREE_NOTHROW (alias_decl);
5283 TREE_USED (decl) = 1;
5286 weak_finish_1 (decl);
5287 # endif
5289 #endif
5292 tree *p;
5293 tree t2;
5295 /* Remove the alias and the target from the pending weak list
5296 so that we do not emit any .weak directives for the former,
5297 nor multiple .weak directives for the latter. */
5298 for (p = &weak_decls; (t2 = *p) ; )
5300 if (TREE_VALUE (t2) == alias_decl
5301 || target == DECL_ASSEMBLER_NAME (TREE_VALUE (t2)))
5302 *p = TREE_CHAIN (t2);
5303 else
5304 p = &TREE_CHAIN (t2);
5307 /* Remove other weakrefs to the same target, to speed things up. */
5308 for (p = &TREE_CHAIN (t); (t2 = *p) ; )
5310 if (target == ultimate_transparent_alias_target (&TREE_VALUE (t2)))
5311 *p = TREE_CHAIN (t2);
5312 else
5313 p = &TREE_CHAIN (t2);
5318 for (t = weak_decls; t; t = TREE_CHAIN (t))
5320 tree decl = TREE_VALUE (t);
5322 weak_finish_1 (decl);
5326 /* Emit the assembly bits to indicate that DECL is globally visible. */
5328 static void
5329 globalize_decl (tree decl)
5332 #if defined (ASM_WEAKEN_LABEL) || defined (ASM_WEAKEN_DECL)
5333 if (DECL_WEAK (decl))
5335 const char *name = XSTR (XEXP (DECL_RTL (decl), 0), 0);
5336 tree *p, t;
5338 #ifdef ASM_WEAKEN_DECL
5339 ASM_WEAKEN_DECL (asm_out_file, decl, name, 0);
5340 #else
5341 ASM_WEAKEN_LABEL (asm_out_file, name);
5342 #endif
5344 /* Remove this function from the pending weak list so that
5345 we do not emit multiple .weak directives for it. */
5346 for (p = &weak_decls; (t = *p) ; )
5348 if (DECL_ASSEMBLER_NAME (decl) == DECL_ASSEMBLER_NAME (TREE_VALUE (t)))
5349 *p = TREE_CHAIN (t);
5350 else
5351 p = &TREE_CHAIN (t);
5354 /* Remove weakrefs to the same target from the pending weakref
5355 list, for the same reason. */
5356 for (p = &weakref_targets; (t = *p) ; )
5358 if (DECL_ASSEMBLER_NAME (decl)
5359 == ultimate_transparent_alias_target (&TREE_VALUE (t)))
5360 *p = TREE_CHAIN (t);
5361 else
5362 p = &TREE_CHAIN (t);
5365 return;
5367 #endif
5369 targetm.asm_out.globalize_decl_name (asm_out_file, decl);
5372 VEC(alias_pair,gc) *alias_pairs;
5374 /* Given an assembly name, find the decl it is associated with. At the
5375 same time, mark it needed for cgraph. */
5377 static tree
5378 find_decl_and_mark_needed (tree decl, tree target)
5380 struct cgraph_node *fnode = NULL;
5381 struct varpool_node *vnode = NULL;
5383 if (TREE_CODE (decl) == FUNCTION_DECL)
5385 fnode = cgraph_node_for_asm (target);
5386 if (fnode == NULL)
5387 vnode = varpool_node_for_asm (target);
5389 else
5391 vnode = varpool_node_for_asm (target);
5392 if (vnode == NULL)
5393 fnode = cgraph_node_for_asm (target);
5396 if (fnode)
5398 /* We can't mark function nodes as used after cgraph global info
5399 is finished. This wouldn't generally be necessary, but C++
5400 virtual table thunks are introduced late in the game and
5401 might seem like they need marking, although in fact they
5402 don't. */
5403 if (! cgraph_global_info_ready)
5404 cgraph_mark_needed_node (fnode);
5405 return fnode->decl;
5407 else if (vnode)
5409 varpool_mark_needed_node (vnode);
5410 return vnode->decl;
5412 else
5413 return NULL_TREE;
5416 /* Output the assembler code for a define (equate) using ASM_OUTPUT_DEF
5417 or ASM_OUTPUT_DEF_FROM_DECLS. The function defines the symbol whose
5418 tree node is DECL to have the value of the tree node TARGET. */
5420 static void
5421 do_assemble_alias (tree decl, tree target)
5423 if (TREE_ASM_WRITTEN (decl))
5424 return;
5426 TREE_ASM_WRITTEN (decl) = 1;
5427 TREE_ASM_WRITTEN (DECL_ASSEMBLER_NAME (decl)) = 1;
5429 if (lookup_attribute ("weakref", DECL_ATTRIBUTES (decl)))
5431 ultimate_transparent_alias_target (&target);
5433 if (!targetm.have_tls
5434 && TREE_CODE (decl) == VAR_DECL
5435 && DECL_THREAD_LOCAL_P (decl))
5437 decl = emutls_decl (decl);
5438 target = get_emutls_object_name (target);
5441 if (!TREE_SYMBOL_REFERENCED (target))
5442 weakref_targets = tree_cons (decl, target, weakref_targets);
5444 #ifdef ASM_OUTPUT_WEAKREF
5445 ASM_OUTPUT_WEAKREF (asm_out_file, decl,
5446 IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl)),
5447 IDENTIFIER_POINTER (target));
5448 #else
5449 if (!SUPPORTS_WEAK)
5451 error_at (DECL_SOURCE_LOCATION (decl),
5452 "weakref is not supported in this configuration");
5453 return;
5455 #endif
5456 return;
5459 if (!targetm.have_tls
5460 && TREE_CODE (decl) == VAR_DECL
5461 && DECL_THREAD_LOCAL_P (decl))
5463 decl = emutls_decl (decl);
5464 target = get_emutls_object_name (target);
5467 #ifdef ASM_OUTPUT_DEF
5468 /* Make name accessible from other files, if appropriate. */
5470 if (TREE_PUBLIC (decl))
5472 globalize_decl (decl);
5473 maybe_assemble_visibility (decl);
5476 # ifdef ASM_OUTPUT_DEF_FROM_DECLS
5477 ASM_OUTPUT_DEF_FROM_DECLS (asm_out_file, decl, target);
5478 # else
5479 ASM_OUTPUT_DEF (asm_out_file,
5480 IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl)),
5481 IDENTIFIER_POINTER (target));
5482 # endif
5483 #elif defined (ASM_OUTPUT_WEAK_ALIAS) || defined (ASM_WEAKEN_DECL)
5485 const char *name;
5486 tree *p, t;
5488 name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
5489 # ifdef ASM_WEAKEN_DECL
5490 ASM_WEAKEN_DECL (asm_out_file, decl, name, IDENTIFIER_POINTER (target));
5491 # else
5492 ASM_OUTPUT_WEAK_ALIAS (asm_out_file, name, IDENTIFIER_POINTER (target));
5493 # endif
5494 /* Remove this function from the pending weak list so that
5495 we do not emit multiple .weak directives for it. */
5496 for (p = &weak_decls; (t = *p) ; )
5497 if (DECL_ASSEMBLER_NAME (decl) == DECL_ASSEMBLER_NAME (TREE_VALUE (t)))
5498 *p = TREE_CHAIN (t);
5499 else
5500 p = &TREE_CHAIN (t);
5502 /* Remove weakrefs to the same target from the pending weakref
5503 list, for the same reason. */
5504 for (p = &weakref_targets; (t = *p) ; )
5506 if (DECL_ASSEMBLER_NAME (decl)
5507 == ultimate_transparent_alias_target (&TREE_VALUE (t)))
5508 *p = TREE_CHAIN (t);
5509 else
5510 p = &TREE_CHAIN (t);
5513 #endif
5517 /* Remove the alias pairing for functions that are no longer in the call
5518 graph. */
5520 void
5521 remove_unreachable_alias_pairs (void)
5523 unsigned i;
5524 alias_pair *p;
5526 if (alias_pairs == NULL)
5527 return;
5529 for (i = 0; VEC_iterate (alias_pair, alias_pairs, i, p); )
5531 if (!DECL_EXTERNAL (p->decl))
5533 struct cgraph_node *fnode = NULL;
5534 struct varpool_node *vnode = NULL;
5535 fnode = cgraph_node_for_asm (p->target);
5536 vnode = (fnode == NULL) ? varpool_node_for_asm (p->target) : NULL;
5537 if (fnode == NULL && vnode == NULL)
5539 VEC_unordered_remove (alias_pair, alias_pairs, i);
5540 continue;
5544 i++;
5549 /* First pass of completing pending aliases. Make sure that cgraph knows
5550 which symbols will be required. */
5552 void
5553 finish_aliases_1 (void)
5555 unsigned i;
5556 alias_pair *p;
5558 for (i = 0; VEC_iterate (alias_pair, alias_pairs, i, p); i++)
5560 tree target_decl;
5562 target_decl = find_decl_and_mark_needed (p->decl, p->target);
5563 if (target_decl == NULL)
5565 if (! lookup_attribute ("weakref", DECL_ATTRIBUTES (p->decl)))
5566 error ("%q+D aliased to undefined symbol %qE",
5567 p->decl, p->target);
5569 else if (DECL_EXTERNAL (target_decl)
5570 /* We use local aliases for C++ thunks to force the tailcall
5571 to bind locally. Of course this is a hack - to keep it
5572 working do the following (which is not strictly correct). */
5573 && (! TREE_CODE (target_decl) == FUNCTION_DECL
5574 || ! TREE_STATIC (target_decl))
5575 && ! lookup_attribute ("weakref", DECL_ATTRIBUTES (p->decl)))
5576 error ("%q+D aliased to external symbol %qE",
5577 p->decl, p->target);
5581 /* Second pass of completing pending aliases. Emit the actual assembly.
5582 This happens at the end of compilation and thus it is assured that the
5583 target symbol has been emitted. */
5585 void
5586 finish_aliases_2 (void)
5588 unsigned i;
5589 alias_pair *p;
5591 for (i = 0; VEC_iterate (alias_pair, alias_pairs, i, p); i++)
5592 do_assemble_alias (p->decl, p->target);
5594 VEC_truncate (alias_pair, alias_pairs, 0);
5597 /* Emit an assembler directive to make the symbol for DECL an alias to
5598 the symbol for TARGET. */
5600 void
5601 assemble_alias (tree decl, tree target)
5603 tree target_decl;
5604 bool is_weakref = false;
5606 if (lookup_attribute ("weakref", DECL_ATTRIBUTES (decl)))
5608 tree alias = DECL_ASSEMBLER_NAME (decl);
5610 is_weakref = true;
5612 ultimate_transparent_alias_target (&target);
5614 if (alias == target)
5615 error ("weakref %q+D ultimately targets itself", decl);
5616 else
5618 #ifndef ASM_OUTPUT_WEAKREF
5619 IDENTIFIER_TRANSPARENT_ALIAS (alias) = 1;
5620 TREE_CHAIN (alias) = target;
5621 #endif
5623 if (TREE_PUBLIC (decl))
5624 error ("weakref %q+D must have static linkage", decl);
5626 else
5628 #if !defined (ASM_OUTPUT_DEF)
5629 # if !defined(ASM_OUTPUT_WEAK_ALIAS) && !defined (ASM_WEAKEN_DECL)
5630 error_at (DECL_SOURCE_LOCATION (decl),
5631 "alias definitions not supported in this configuration");
5632 return;
5633 # else
5634 if (!DECL_WEAK (decl))
5636 error_at (DECL_SOURCE_LOCATION (decl),
5637 "only weak aliases are supported in this configuration");
5638 return;
5640 # endif
5641 #endif
5644 /* We must force creation of DECL_RTL for debug info generation, even though
5645 we don't use it here. */
5646 make_decl_rtl (decl);
5647 TREE_USED (decl) = 1;
5649 /* A quirk of the initial implementation of aliases required that the user
5650 add "extern" to all of them. Which is silly, but now historical. Do
5651 note that the symbol is in fact locally defined. */
5652 if (! is_weakref)
5653 DECL_EXTERNAL (decl) = 0;
5655 /* Allow aliases to aliases. */
5656 if (TREE_CODE (decl) == FUNCTION_DECL)
5657 cgraph_node (decl)->alias = true;
5658 else
5659 varpool_node (decl)->alias = true;
5661 /* If the target has already been emitted, we don't have to queue the
5662 alias. This saves a tad of memory. */
5663 if (cgraph_global_info_ready)
5664 target_decl = find_decl_and_mark_needed (decl, target);
5665 else
5666 target_decl= NULL;
5667 if (target_decl && TREE_ASM_WRITTEN (target_decl))
5668 do_assemble_alias (decl, target);
5669 else
5671 alias_pair *p = VEC_safe_push (alias_pair, gc, alias_pairs, NULL);
5672 p->decl = decl;
5673 p->target = target;
5677 /* Emit an assembler directive to set symbol for DECL visibility to
5678 the visibility type VIS, which must not be VISIBILITY_DEFAULT. */
5680 void
5681 default_assemble_visibility (tree decl, int vis)
5683 static const char * const visibility_types[] = {
5684 NULL, "protected", "hidden", "internal"
5687 const char *name, *type;
5689 name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
5690 type = visibility_types[vis];
5692 #ifdef HAVE_GAS_HIDDEN
5693 fprintf (asm_out_file, "\t.%s\t", type);
5694 assemble_name (asm_out_file, name);
5695 fprintf (asm_out_file, "\n");
5696 #else
5697 warning (OPT_Wattributes, "visibility attribute not supported "
5698 "in this configuration; ignored");
5699 #endif
5702 /* A helper function to call assemble_visibility when needed for a decl. */
5705 maybe_assemble_visibility (tree decl)
5707 enum symbol_visibility vis = DECL_VISIBILITY (decl);
5709 if (vis != VISIBILITY_DEFAULT)
5711 targetm.asm_out.visibility (decl, vis);
5712 return 1;
5714 else
5715 return 0;
5718 /* Returns 1 if the target configuration supports defining public symbols
5719 so that one of them will be chosen at link time instead of generating a
5720 multiply-defined symbol error, whether through the use of weak symbols or
5721 a target-specific mechanism for having duplicates discarded. */
5724 supports_one_only (void)
5726 if (SUPPORTS_ONE_ONLY)
5727 return 1;
5728 return SUPPORTS_WEAK;
5731 /* Set up DECL as a public symbol that can be defined in multiple
5732 translation units without generating a linker error. */
5734 void
5735 make_decl_one_only (tree decl, tree comdat_group)
5737 gcc_assert (TREE_CODE (decl) == VAR_DECL
5738 || TREE_CODE (decl) == FUNCTION_DECL);
5740 TREE_PUBLIC (decl) = 1;
5742 if (SUPPORTS_ONE_ONLY)
5744 #ifdef MAKE_DECL_ONE_ONLY
5745 MAKE_DECL_ONE_ONLY (decl);
5746 #endif
5747 DECL_COMDAT_GROUP (decl) = comdat_group;
5749 else if (TREE_CODE (decl) == VAR_DECL
5750 && (DECL_INITIAL (decl) == 0 || DECL_INITIAL (decl) == error_mark_node))
5751 DECL_COMMON (decl) = 1;
5752 else
5754 gcc_assert (SUPPORTS_WEAK);
5755 DECL_WEAK (decl) = 1;
5759 void
5760 init_varasm_once (void)
5762 section_htab = htab_create_ggc (31, section_entry_hash,
5763 section_entry_eq, NULL);
5764 object_block_htab = htab_create_ggc (31, object_block_entry_hash,
5765 object_block_entry_eq, NULL);
5766 const_desc_htab = htab_create_ggc (1009, const_desc_hash,
5767 const_desc_eq, NULL);
5769 const_alias_set = new_alias_set ();
5770 shared_constant_pool = create_constant_pool ();
5772 #ifdef TEXT_SECTION_ASM_OP
5773 text_section = get_unnamed_section (SECTION_CODE, output_section_asm_op,
5774 TEXT_SECTION_ASM_OP);
5775 #endif
5777 #ifdef DATA_SECTION_ASM_OP
5778 data_section = get_unnamed_section (SECTION_WRITE, output_section_asm_op,
5779 DATA_SECTION_ASM_OP);
5780 #endif
5782 #ifdef SDATA_SECTION_ASM_OP
5783 sdata_section = get_unnamed_section (SECTION_WRITE, output_section_asm_op,
5784 SDATA_SECTION_ASM_OP);
5785 #endif
5787 #ifdef READONLY_DATA_SECTION_ASM_OP
5788 readonly_data_section = get_unnamed_section (0, output_section_asm_op,
5789 READONLY_DATA_SECTION_ASM_OP);
5790 #endif
5792 #ifdef CTORS_SECTION_ASM_OP
5793 ctors_section = get_unnamed_section (0, output_section_asm_op,
5794 CTORS_SECTION_ASM_OP);
5795 #endif
5797 #ifdef DTORS_SECTION_ASM_OP
5798 dtors_section = get_unnamed_section (0, output_section_asm_op,
5799 DTORS_SECTION_ASM_OP);
5800 #endif
5802 #ifdef BSS_SECTION_ASM_OP
5803 bss_section = get_unnamed_section (SECTION_WRITE | SECTION_BSS,
5804 output_section_asm_op,
5805 BSS_SECTION_ASM_OP);
5806 #endif
5808 #ifdef SBSS_SECTION_ASM_OP
5809 sbss_section = get_unnamed_section (SECTION_WRITE | SECTION_BSS,
5810 output_section_asm_op,
5811 SBSS_SECTION_ASM_OP);
5812 #endif
5814 tls_comm_section = get_noswitch_section (SECTION_WRITE | SECTION_BSS
5815 | SECTION_COMMON, emit_tls_common);
5816 lcomm_section = get_noswitch_section (SECTION_WRITE | SECTION_BSS
5817 | SECTION_COMMON, emit_local);
5818 comm_section = get_noswitch_section (SECTION_WRITE | SECTION_BSS
5819 | SECTION_COMMON, emit_common);
5821 #if defined ASM_OUTPUT_ALIGNED_BSS || defined ASM_OUTPUT_BSS
5822 bss_noswitch_section = get_noswitch_section (SECTION_WRITE | SECTION_BSS,
5823 emit_bss);
5824 #endif
5826 targetm.asm_out.init_sections ();
5828 if (readonly_data_section == NULL)
5829 readonly_data_section = text_section;
5832 enum tls_model
5833 decl_default_tls_model (const_tree decl)
5835 enum tls_model kind;
5836 bool is_local;
5838 is_local = targetm.binds_local_p (decl);
5839 if (!flag_shlib)
5841 if (is_local)
5842 kind = TLS_MODEL_LOCAL_EXEC;
5843 else
5844 kind = TLS_MODEL_INITIAL_EXEC;
5847 /* Local dynamic is inefficient when we're not combining the
5848 parts of the address. */
5849 else if (optimize && is_local)
5850 kind = TLS_MODEL_LOCAL_DYNAMIC;
5851 else
5852 kind = TLS_MODEL_GLOBAL_DYNAMIC;
5853 if (kind < flag_tls_default)
5854 kind = flag_tls_default;
5856 return kind;
5859 /* Select a set of attributes for section NAME based on the properties
5860 of DECL and whether or not RELOC indicates that DECL's initializer
5861 might contain runtime relocations.
5863 We make the section read-only and executable for a function decl,
5864 read-only for a const data decl, and writable for a non-const data decl. */
5866 unsigned int
5867 default_section_type_flags (tree decl, const char *name, int reloc)
5869 unsigned int flags;
5871 if (decl && TREE_CODE (decl) == FUNCTION_DECL)
5872 flags = SECTION_CODE;
5873 else if (decl && decl_readonly_section (decl, reloc))
5874 flags = 0;
5875 else if (current_function_decl
5876 && cfun
5877 && crtl->subsections.unlikely_text_section_name
5878 && strcmp (name, crtl->subsections.unlikely_text_section_name) == 0)
5879 flags = SECTION_CODE;
5880 else if (!decl
5881 && (!current_function_decl || !cfun)
5882 && strcmp (name, UNLIKELY_EXECUTED_TEXT_SECTION_NAME) == 0)
5883 flags = SECTION_CODE;
5884 else
5885 flags = SECTION_WRITE;
5887 if (decl && DECL_ONE_ONLY (decl))
5888 flags |= SECTION_LINKONCE;
5890 if (decl && TREE_CODE (decl) == VAR_DECL && DECL_THREAD_LOCAL_P (decl))
5891 flags |= SECTION_TLS | SECTION_WRITE;
5893 if (strcmp (name, ".bss") == 0
5894 || strncmp (name, ".bss.", 5) == 0
5895 || strncmp (name, ".gnu.linkonce.b.", 16) == 0
5896 || strcmp (name, ".sbss") == 0
5897 || strncmp (name, ".sbss.", 6) == 0
5898 || strncmp (name, ".gnu.linkonce.sb.", 17) == 0)
5899 flags |= SECTION_BSS;
5901 if (strcmp (name, ".tdata") == 0
5902 || strncmp (name, ".tdata.", 7) == 0
5903 || strncmp (name, ".gnu.linkonce.td.", 17) == 0)
5904 flags |= SECTION_TLS;
5906 if (strcmp (name, ".tbss") == 0
5907 || strncmp (name, ".tbss.", 6) == 0
5908 || strncmp (name, ".gnu.linkonce.tb.", 17) == 0)
5909 flags |= SECTION_TLS | SECTION_BSS;
5911 /* These three sections have special ELF types. They are neither
5912 SHT_PROGBITS nor SHT_NOBITS, so when changing sections we don't
5913 want to print a section type (@progbits or @nobits). If someone
5914 is silly enough to emit code or TLS variables to one of these
5915 sections, then don't handle them specially. */
5916 if (!(flags & (SECTION_CODE | SECTION_BSS | SECTION_TLS))
5917 && (strcmp (name, ".init_array") == 0
5918 || strcmp (name, ".fini_array") == 0
5919 || strcmp (name, ".preinit_array") == 0))
5920 flags |= SECTION_NOTYPE;
5922 return flags;
5925 /* Return true if the target supports some form of global BSS,
5926 either through bss_noswitch_section, or by selecting a BSS
5927 section in TARGET_ASM_SELECT_SECTION. */
5929 bool
5930 have_global_bss_p (void)
5932 return bss_noswitch_section || targetm.have_switchable_bss_sections;
5935 /* Output assembly to switch to section NAME with attribute FLAGS.
5936 Four variants for common object file formats. */
5938 void
5939 default_no_named_section (const char *name ATTRIBUTE_UNUSED,
5940 unsigned int flags ATTRIBUTE_UNUSED,
5941 tree decl ATTRIBUTE_UNUSED)
5943 /* Some object formats don't support named sections at all. The
5944 front-end should already have flagged this as an error. */
5945 gcc_unreachable ();
5948 void
5949 default_elf_asm_named_section (const char *name, unsigned int flags,
5950 tree decl ATTRIBUTE_UNUSED)
5952 char flagchars[10], *f = flagchars;
5954 /* If we have already declared this section, we can use an
5955 abbreviated form to switch back to it -- unless this section is
5956 part of a COMDAT groups, in which case GAS requires the full
5957 declaration every time. */
5958 if (!(HAVE_COMDAT_GROUP && (flags & SECTION_LINKONCE))
5959 && (flags & SECTION_DECLARED))
5961 fprintf (asm_out_file, "\t.section\t%s\n", name);
5962 return;
5965 if (!(flags & SECTION_DEBUG))
5966 *f++ = 'a';
5967 if (flags & SECTION_WRITE)
5968 *f++ = 'w';
5969 if (flags & SECTION_CODE)
5970 *f++ = 'x';
5971 if (flags & SECTION_SMALL)
5972 *f++ = 's';
5973 if (flags & SECTION_MERGE)
5974 *f++ = 'M';
5975 if (flags & SECTION_STRINGS)
5976 *f++ = 'S';
5977 if (flags & SECTION_TLS)
5978 *f++ = 'T';
5979 if (HAVE_COMDAT_GROUP && (flags & SECTION_LINKONCE))
5980 *f++ = 'G';
5981 *f = '\0';
5983 fprintf (asm_out_file, "\t.section\t%s,\"%s\"", name, flagchars);
5985 if (!(flags & SECTION_NOTYPE))
5987 const char *type;
5988 const char *format;
5990 if (flags & SECTION_BSS)
5991 type = "nobits";
5992 else
5993 type = "progbits";
5995 format = ",@%s";
5996 #ifdef ASM_COMMENT_START
5997 /* On platforms that use "@" as the assembly comment character,
5998 use "%" instead. */
5999 if (strcmp (ASM_COMMENT_START, "@") == 0)
6000 format = ",%%%s";
6001 #endif
6002 fprintf (asm_out_file, format, type);
6004 if (flags & SECTION_ENTSIZE)
6005 fprintf (asm_out_file, ",%d", flags & SECTION_ENTSIZE);
6006 if (HAVE_COMDAT_GROUP && (flags & SECTION_LINKONCE))
6007 fprintf (asm_out_file, ",%s,comdat",
6008 IDENTIFIER_POINTER (DECL_COMDAT_GROUP (decl)));
6011 putc ('\n', asm_out_file);
6014 void
6015 default_coff_asm_named_section (const char *name, unsigned int flags,
6016 tree decl ATTRIBUTE_UNUSED)
6018 char flagchars[8], *f = flagchars;
6020 if (flags & SECTION_WRITE)
6021 *f++ = 'w';
6022 if (flags & SECTION_CODE)
6023 *f++ = 'x';
6024 *f = '\0';
6026 fprintf (asm_out_file, "\t.section\t%s,\"%s\"\n", name, flagchars);
6029 void
6030 default_pe_asm_named_section (const char *name, unsigned int flags,
6031 tree decl)
6033 default_coff_asm_named_section (name, flags, decl);
6035 if (flags & SECTION_LINKONCE)
6037 /* Functions may have been compiled at various levels of
6038 optimization so we can't use `same_size' here.
6039 Instead, have the linker pick one. */
6040 fprintf (asm_out_file, "\t.linkonce %s\n",
6041 (flags & SECTION_CODE ? "discard" : "same_size"));
6045 /* The lame default section selector. */
6047 section *
6048 default_select_section (tree decl, int reloc,
6049 unsigned HOST_WIDE_INT align ATTRIBUTE_UNUSED)
6051 if (DECL_P (decl))
6053 if (decl_readonly_section (decl, reloc))
6054 return readonly_data_section;
6056 else if (TREE_CODE (decl) == CONSTRUCTOR)
6058 if (! ((flag_pic && reloc)
6059 || !TREE_READONLY (decl)
6060 || TREE_SIDE_EFFECTS (decl)
6061 || !TREE_CONSTANT (decl)))
6062 return readonly_data_section;
6064 else if (TREE_CODE (decl) == STRING_CST)
6065 return readonly_data_section;
6066 else if (! (flag_pic && reloc))
6067 return readonly_data_section;
6069 return data_section;
6072 enum section_category
6073 categorize_decl_for_section (const_tree decl, int reloc)
6075 enum section_category ret;
6077 if (TREE_CODE (decl) == FUNCTION_DECL)
6078 return SECCAT_TEXT;
6079 else if (TREE_CODE (decl) == STRING_CST)
6081 if (flag_mudflap) /* or !flag_merge_constants */
6082 return SECCAT_RODATA;
6083 else
6084 return SECCAT_RODATA_MERGE_STR;
6086 else if (TREE_CODE (decl) == VAR_DECL)
6088 if (bss_initializer_p (decl))
6089 ret = SECCAT_BSS;
6090 else if (! TREE_READONLY (decl)
6091 || TREE_SIDE_EFFECTS (decl)
6092 || ! TREE_CONSTANT (DECL_INITIAL (decl)))
6094 /* Here the reloc_rw_mask is not testing whether the section should
6095 be read-only or not, but whether the dynamic link will have to
6096 do something. If so, we wish to segregate the data in order to
6097 minimize cache misses inside the dynamic linker. */
6098 if (reloc & targetm.asm_out.reloc_rw_mask ())
6099 ret = reloc == 1 ? SECCAT_DATA_REL_LOCAL : SECCAT_DATA_REL;
6100 else
6101 ret = SECCAT_DATA;
6103 else if (reloc & targetm.asm_out.reloc_rw_mask ())
6104 ret = reloc == 1 ? SECCAT_DATA_REL_RO_LOCAL : SECCAT_DATA_REL_RO;
6105 else if (reloc || flag_merge_constants < 2)
6106 /* C and C++ don't allow different variables to share the same
6107 location. -fmerge-all-constants allows even that (at the
6108 expense of not conforming). */
6109 ret = SECCAT_RODATA;
6110 else if (TREE_CODE (DECL_INITIAL (decl)) == STRING_CST)
6111 ret = SECCAT_RODATA_MERGE_STR_INIT;
6112 else
6113 ret = SECCAT_RODATA_MERGE_CONST;
6115 else if (TREE_CODE (decl) == CONSTRUCTOR)
6117 if ((reloc & targetm.asm_out.reloc_rw_mask ())
6118 || TREE_SIDE_EFFECTS (decl)
6119 || ! TREE_CONSTANT (decl))
6120 ret = SECCAT_DATA;
6121 else
6122 ret = SECCAT_RODATA;
6124 else
6125 ret = SECCAT_RODATA;
6127 /* There are no read-only thread-local sections. */
6128 if (TREE_CODE (decl) == VAR_DECL && DECL_TLS_MODEL (decl))
6130 if (DECL_TLS_MODEL (decl) == TLS_MODEL_EMULATED)
6132 if (DECL_EMUTLS_VAR_P (decl))
6134 if (targetm.emutls.var_section)
6135 ret = SECCAT_EMUTLS_VAR;
6137 else
6139 if (targetm.emutls.tmpl_prefix)
6140 ret = SECCAT_EMUTLS_TMPL;
6143 /* Note that this would be *just* SECCAT_BSS, except that there's
6144 no concept of a read-only thread-local-data section. */
6145 else if (ret == SECCAT_BSS
6146 || (flag_zero_initialized_in_bss
6147 && initializer_zerop (DECL_INITIAL (decl))))
6148 ret = SECCAT_TBSS;
6149 else
6150 ret = SECCAT_TDATA;
6153 /* If the target uses small data sections, select it. */
6154 else if (targetm.in_small_data_p (decl))
6156 if (ret == SECCAT_BSS)
6157 ret = SECCAT_SBSS;
6158 else if (targetm.have_srodata_section && ret == SECCAT_RODATA)
6159 ret = SECCAT_SRODATA;
6160 else
6161 ret = SECCAT_SDATA;
6164 return ret;
6167 bool
6168 decl_readonly_section (const_tree decl, int reloc)
6170 switch (categorize_decl_for_section (decl, reloc))
6172 case SECCAT_RODATA:
6173 case SECCAT_RODATA_MERGE_STR:
6174 case SECCAT_RODATA_MERGE_STR_INIT:
6175 case SECCAT_RODATA_MERGE_CONST:
6176 case SECCAT_SRODATA:
6177 return true;
6178 break;
6179 default:
6180 return false;
6181 break;
6185 /* Select a section based on the above categorization. */
6187 section *
6188 default_elf_select_section (tree decl, int reloc,
6189 unsigned HOST_WIDE_INT align)
6191 const char *sname;
6192 switch (categorize_decl_for_section (decl, reloc))
6194 case SECCAT_TEXT:
6195 /* We're not supposed to be called on FUNCTION_DECLs. */
6196 gcc_unreachable ();
6197 case SECCAT_RODATA:
6198 return readonly_data_section;
6199 case SECCAT_RODATA_MERGE_STR:
6200 return mergeable_string_section (decl, align, 0);
6201 case SECCAT_RODATA_MERGE_STR_INIT:
6202 return mergeable_string_section (DECL_INITIAL (decl), align, 0);
6203 case SECCAT_RODATA_MERGE_CONST:
6204 return mergeable_constant_section (DECL_MODE (decl), align, 0);
6205 case SECCAT_SRODATA:
6206 sname = ".sdata2";
6207 break;
6208 case SECCAT_DATA:
6209 return data_section;
6210 case SECCAT_DATA_REL:
6211 sname = ".data.rel";
6212 break;
6213 case SECCAT_DATA_REL_LOCAL:
6214 sname = ".data.rel.local";
6215 break;
6216 case SECCAT_DATA_REL_RO:
6217 sname = ".data.rel.ro";
6218 break;
6219 case SECCAT_DATA_REL_RO_LOCAL:
6220 sname = ".data.rel.ro.local";
6221 break;
6222 case SECCAT_SDATA:
6223 sname = ".sdata";
6224 break;
6225 case SECCAT_TDATA:
6226 sname = ".tdata";
6227 break;
6228 case SECCAT_BSS:
6229 if (bss_section)
6230 return bss_section;
6231 sname = ".bss";
6232 break;
6233 case SECCAT_SBSS:
6234 sname = ".sbss";
6235 break;
6236 case SECCAT_TBSS:
6237 sname = ".tbss";
6238 break;
6239 case SECCAT_EMUTLS_VAR:
6240 sname = targetm.emutls.var_section;
6241 break;
6242 case SECCAT_EMUTLS_TMPL:
6243 sname = targetm.emutls.tmpl_section;
6244 break;
6245 default:
6246 gcc_unreachable ();
6249 if (!DECL_P (decl))
6250 decl = NULL_TREE;
6251 return get_named_section (decl, sname, reloc);
6254 /* Construct a unique section name based on the decl name and the
6255 categorization performed above. */
6257 void
6258 default_unique_section (tree decl, int reloc)
6260 /* We only need to use .gnu.linkonce if we don't have COMDAT groups. */
6261 bool one_only = DECL_ONE_ONLY (decl) && !HAVE_COMDAT_GROUP;
6262 const char *prefix, *name, *linkonce;
6263 char *string;
6265 switch (categorize_decl_for_section (decl, reloc))
6267 case SECCAT_TEXT:
6268 prefix = one_only ? ".t" : ".text";
6269 break;
6270 case SECCAT_RODATA:
6271 case SECCAT_RODATA_MERGE_STR:
6272 case SECCAT_RODATA_MERGE_STR_INIT:
6273 case SECCAT_RODATA_MERGE_CONST:
6274 prefix = one_only ? ".r" : ".rodata";
6275 break;
6276 case SECCAT_SRODATA:
6277 prefix = one_only ? ".s2" : ".sdata2";
6278 break;
6279 case SECCAT_DATA:
6280 prefix = one_only ? ".d" : ".data";
6281 break;
6282 case SECCAT_DATA_REL:
6283 prefix = one_only ? ".d.rel" : ".data.rel";
6284 break;
6285 case SECCAT_DATA_REL_LOCAL:
6286 prefix = one_only ? ".d.rel.local" : ".data.rel.local";
6287 break;
6288 case SECCAT_DATA_REL_RO:
6289 prefix = one_only ? ".d.rel.ro" : ".data.rel.ro";
6290 break;
6291 case SECCAT_DATA_REL_RO_LOCAL:
6292 prefix = one_only ? ".d.rel.ro.local" : ".data.rel.ro.local";
6293 break;
6294 case SECCAT_SDATA:
6295 prefix = one_only ? ".s" : ".sdata";
6296 break;
6297 case SECCAT_BSS:
6298 prefix = one_only ? ".b" : ".bss";
6299 break;
6300 case SECCAT_SBSS:
6301 prefix = one_only ? ".sb" : ".sbss";
6302 break;
6303 case SECCAT_TDATA:
6304 prefix = one_only ? ".td" : ".tdata";
6305 break;
6306 case SECCAT_TBSS:
6307 prefix = one_only ? ".tb" : ".tbss";
6308 break;
6309 case SECCAT_EMUTLS_VAR:
6310 prefix = targetm.emutls.var_section;
6311 break;
6312 case SECCAT_EMUTLS_TMPL:
6313 prefix = targetm.emutls.tmpl_section;
6314 break;
6315 default:
6316 gcc_unreachable ();
6319 name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
6320 name = targetm.strip_name_encoding (name);
6322 /* If we're using one_only, then there needs to be a .gnu.linkonce
6323 prefix to the section name. */
6324 linkonce = one_only ? ".gnu.linkonce" : "";
6326 string = ACONCAT ((linkonce, prefix, ".", name, NULL));
6328 DECL_SECTION_NAME (decl) = build_string (strlen (string), string);
6331 /* Like compute_reloc_for_constant, except for an RTX. The return value
6332 is a mask for which bit 1 indicates a global relocation, and bit 0
6333 indicates a local relocation. */
6335 static int
6336 compute_reloc_for_rtx_1 (rtx *xp, void *data)
6338 int *preloc = (int *) data;
6339 rtx x = *xp;
6341 switch (GET_CODE (x))
6343 case SYMBOL_REF:
6344 *preloc |= SYMBOL_REF_LOCAL_P (x) ? 1 : 2;
6345 break;
6346 case LABEL_REF:
6347 *preloc |= 1;
6348 break;
6349 default:
6350 break;
6353 return 0;
6356 static int
6357 compute_reloc_for_rtx (rtx x)
6359 int reloc;
6361 switch (GET_CODE (x))
6363 case CONST:
6364 case SYMBOL_REF:
6365 case LABEL_REF:
6366 reloc = 0;
6367 for_each_rtx (&x, compute_reloc_for_rtx_1, &reloc);
6368 return reloc;
6370 default:
6371 return 0;
6375 section *
6376 default_select_rtx_section (enum machine_mode mode ATTRIBUTE_UNUSED,
6377 rtx x,
6378 unsigned HOST_WIDE_INT align ATTRIBUTE_UNUSED)
6380 if (compute_reloc_for_rtx (x) & targetm.asm_out.reloc_rw_mask ())
6381 return data_section;
6382 else
6383 return readonly_data_section;
6386 section *
6387 default_elf_select_rtx_section (enum machine_mode mode, rtx x,
6388 unsigned HOST_WIDE_INT align)
6390 int reloc = compute_reloc_for_rtx (x);
6392 /* ??? Handle small data here somehow. */
6394 if (reloc & targetm.asm_out.reloc_rw_mask ())
6396 if (reloc == 1)
6397 return get_named_section (NULL, ".data.rel.ro.local", 1);
6398 else
6399 return get_named_section (NULL, ".data.rel.ro", 3);
6402 return mergeable_constant_section (mode, align, 0);
6405 /* Set the generally applicable flags on the SYMBOL_REF for EXP. */
6407 void
6408 default_encode_section_info (tree decl, rtx rtl, int first ATTRIBUTE_UNUSED)
6410 rtx symbol;
6411 int flags;
6413 /* Careful not to prod global register variables. */
6414 if (!MEM_P (rtl))
6415 return;
6416 symbol = XEXP (rtl, 0);
6417 if (GET_CODE (symbol) != SYMBOL_REF)
6418 return;
6420 flags = SYMBOL_REF_FLAGS (symbol) & SYMBOL_FLAG_HAS_BLOCK_INFO;
6421 if (TREE_CODE (decl) == FUNCTION_DECL)
6422 flags |= SYMBOL_FLAG_FUNCTION;
6423 if (targetm.binds_local_p (decl))
6424 flags |= SYMBOL_FLAG_LOCAL;
6425 if (targetm.have_tls && TREE_CODE (decl) == VAR_DECL
6426 && DECL_THREAD_LOCAL_P (decl))
6427 flags |= DECL_TLS_MODEL (decl) << SYMBOL_FLAG_TLS_SHIFT;
6428 else if (targetm.in_small_data_p (decl))
6429 flags |= SYMBOL_FLAG_SMALL;
6430 /* ??? Why is DECL_EXTERNAL ever set for non-PUBLIC names? Without
6431 being PUBLIC, the thing *must* be defined in this translation unit.
6432 Prevent this buglet from being propagated into rtl code as well. */
6433 if (DECL_P (decl) && DECL_EXTERNAL (decl) && TREE_PUBLIC (decl))
6434 flags |= SYMBOL_FLAG_EXTERNAL;
6436 SYMBOL_REF_FLAGS (symbol) = flags;
6439 /* By default, we do nothing for encode_section_info, so we need not
6440 do anything but discard the '*' marker. */
6442 const char *
6443 default_strip_name_encoding (const char *str)
6445 return str + (*str == '*');
6448 #ifdef ASM_OUTPUT_DEF
6449 /* The default implementation of TARGET_ASM_OUTPUT_ANCHOR. Define the
6450 anchor relative to ".", the current section position. */
6452 void
6453 default_asm_output_anchor (rtx symbol)
6455 char buffer[100];
6457 sprintf (buffer, "*. + " HOST_WIDE_INT_PRINT_DEC,
6458 SYMBOL_REF_BLOCK_OFFSET (symbol));
6459 ASM_OUTPUT_DEF (asm_out_file, XSTR (symbol, 0), buffer);
6461 #endif
6463 /* The default implementation of TARGET_USE_ANCHORS_FOR_SYMBOL_P. */
6465 bool
6466 default_use_anchors_for_symbol_p (const_rtx symbol)
6468 section *sect;
6469 tree decl;
6471 /* Don't use anchors for mergeable sections. The linker might move
6472 the objects around. */
6473 sect = SYMBOL_REF_BLOCK (symbol)->sect;
6474 if (sect->common.flags & SECTION_MERGE)
6475 return false;
6477 /* Don't use anchors for small data sections. The small data register
6478 acts as an anchor for such sections. */
6479 if (sect->common.flags & SECTION_SMALL)
6480 return false;
6482 decl = SYMBOL_REF_DECL (symbol);
6483 if (decl && DECL_P (decl))
6485 /* Don't use section anchors for decls that might be defined by
6486 other modules. */
6487 if (!targetm.binds_local_p (decl))
6488 return false;
6490 /* Don't use section anchors for decls that will be placed in a
6491 small data section. */
6492 /* ??? Ideally, this check would be redundant with the SECTION_SMALL
6493 one above. The problem is that we only use SECTION_SMALL for
6494 sections that should be marked as small in the section directive. */
6495 if (targetm.in_small_data_p (decl))
6496 return false;
6498 return true;
6501 /* Assume ELF-ish defaults, since that's pretty much the most liberal
6502 wrt cross-module name binding. */
6504 bool
6505 default_binds_local_p (const_tree exp)
6507 return default_binds_local_p_1 (exp, flag_shlib);
6510 bool
6511 default_binds_local_p_1 (const_tree exp, int shlib)
6513 bool local_p;
6515 /* A non-decl is an entry in the constant pool. */
6516 if (!DECL_P (exp))
6517 local_p = true;
6518 /* Weakrefs may not bind locally, even though the weakref itself is
6519 always static and therefore local. */
6520 else if (lookup_attribute ("weakref", DECL_ATTRIBUTES (exp)))
6521 local_p = false;
6522 /* Static variables are always local. */
6523 else if (! TREE_PUBLIC (exp))
6524 local_p = true;
6525 /* A variable is local if the user has said explicitly that it will
6526 be. */
6527 else if (DECL_VISIBILITY_SPECIFIED (exp)
6528 && DECL_VISIBILITY (exp) != VISIBILITY_DEFAULT)
6529 local_p = true;
6530 /* Variables defined outside this object might not be local. */
6531 else if (DECL_EXTERNAL (exp))
6532 local_p = false;
6533 /* If defined in this object and visibility is not default, must be
6534 local. */
6535 else if (DECL_VISIBILITY (exp) != VISIBILITY_DEFAULT)
6536 local_p = true;
6537 /* Default visibility weak data can be overridden by a strong symbol
6538 in another module and so are not local. */
6539 else if (DECL_WEAK (exp))
6540 local_p = false;
6541 /* If PIC, then assume that any global name can be overridden by
6542 symbols resolved from other modules, unless we are compiling with
6543 -fwhole-program, which assumes that names are local. */
6544 else if (shlib)
6545 local_p = flag_whole_program;
6546 /* Uninitialized COMMON variable may be unified with symbols
6547 resolved from other modules. */
6548 else if (DECL_COMMON (exp)
6549 && (DECL_INITIAL (exp) == NULL
6550 || DECL_INITIAL (exp) == error_mark_node))
6551 local_p = false;
6552 /* Otherwise we're left with initialized (or non-common) global data
6553 which is of necessity defined locally. */
6554 else
6555 local_p = true;
6557 return local_p;
6560 /* Determine whether or not a pointer mode is valid. Assume defaults
6561 of ptr_mode or Pmode - can be overridden. */
6562 bool
6563 default_valid_pointer_mode (enum machine_mode mode)
6565 return (mode == ptr_mode || mode == Pmode);
6568 /* Default function to output code that will globalize a label. A
6569 target must define GLOBAL_ASM_OP or provide its own function to
6570 globalize a label. */
6571 #ifdef GLOBAL_ASM_OP
6572 void
6573 default_globalize_label (FILE * stream, const char *name)
6575 fputs (GLOBAL_ASM_OP, stream);
6576 assemble_name (stream, name);
6577 putc ('\n', stream);
6579 #endif /* GLOBAL_ASM_OP */
6581 /* Default function to output code that will globalize a declaration. */
6582 void
6583 default_globalize_decl_name (FILE * stream, tree decl)
6585 const char *name = XSTR (XEXP (DECL_RTL (decl), 0), 0);
6586 targetm.asm_out.globalize_label (stream, name);
6589 /* Default function to output a label for unwind information. The
6590 default is to do nothing. A target that needs nonlocal labels for
6591 unwind information must provide its own function to do this. */
6592 void
6593 default_emit_unwind_label (FILE * stream ATTRIBUTE_UNUSED,
6594 tree decl ATTRIBUTE_UNUSED,
6595 int for_eh ATTRIBUTE_UNUSED,
6596 int empty ATTRIBUTE_UNUSED)
6600 /* Default function to output a label to divide up the exception table.
6601 The default is to do nothing. A target that needs/wants to divide
6602 up the table must provide it's own function to do this. */
6603 void
6604 default_emit_except_table_label (FILE * stream ATTRIBUTE_UNUSED)
6608 /* This is how to output an internal numbered label where PREFIX is
6609 the class of label and LABELNO is the number within the class. */
6611 void
6612 default_internal_label (FILE *stream, const char *prefix,
6613 unsigned long labelno)
6615 char *const buf = (char *) alloca (40 + strlen (prefix));
6616 ASM_GENERATE_INTERNAL_LABEL (buf, prefix, labelno);
6617 ASM_OUTPUT_INTERNAL_LABEL (stream, buf);
6620 /* This is the default behavior at the beginning of a file. It's
6621 controlled by two other target-hook toggles. */
6622 void
6623 default_file_start (void)
6625 if (targetm.file_start_app_off
6626 && !(flag_verbose_asm || flag_debug_asm || flag_dump_rtl_in_asm))
6627 fputs (ASM_APP_OFF, asm_out_file);
6629 if (targetm.file_start_file_directive)
6630 output_file_directive (asm_out_file, main_input_filename);
6633 /* This is a generic routine suitable for use as TARGET_ASM_FILE_END
6634 which emits a special section directive used to indicate whether or
6635 not this object file needs an executable stack. This is primarily
6636 a GNU extension to ELF but could be used on other targets. */
6638 int trampolines_created;
6640 void
6641 file_end_indicate_exec_stack (void)
6643 unsigned int flags = SECTION_DEBUG;
6644 if (trampolines_created)
6645 flags |= SECTION_CODE;
6647 switch_to_section (get_section (".note.GNU-stack", flags, NULL));
6650 /* Output DIRECTIVE (a C string) followed by a newline. This is used as
6651 a get_unnamed_section callback. */
6653 void
6654 output_section_asm_op (const void *directive)
6656 fprintf (asm_out_file, "%s\n", (const char *) directive);
6659 /* Emit assembly code to switch to section NEW_SECTION. Do nothing if
6660 the current section is NEW_SECTION. */
6662 void
6663 switch_to_section (section *new_section)
6665 if (in_section == new_section)
6666 return;
6668 if (new_section->common.flags & SECTION_FORGET)
6669 in_section = NULL;
6670 else
6671 in_section = new_section;
6673 switch (SECTION_STYLE (new_section))
6675 case SECTION_NAMED:
6676 if (cfun
6677 && !crtl->subsections.unlikely_text_section_name
6678 && strcmp (new_section->named.name,
6679 UNLIKELY_EXECUTED_TEXT_SECTION_NAME) == 0)
6680 crtl->subsections.unlikely_text_section_name = UNLIKELY_EXECUTED_TEXT_SECTION_NAME;
6682 targetm.asm_out.named_section (new_section->named.name,
6683 new_section->named.common.flags,
6684 new_section->named.decl);
6685 break;
6687 case SECTION_UNNAMED:
6688 new_section->unnamed.callback (new_section->unnamed.data);
6689 break;
6691 case SECTION_NOSWITCH:
6692 gcc_unreachable ();
6693 break;
6696 new_section->common.flags |= SECTION_DECLARED;
6699 /* If block symbol SYMBOL has not yet been assigned an offset, place
6700 it at the end of its block. */
6702 void
6703 place_block_symbol (rtx symbol)
6705 unsigned HOST_WIDE_INT size, mask, offset;
6706 struct constant_descriptor_rtx *desc;
6707 unsigned int alignment;
6708 struct object_block *block;
6709 tree decl;
6711 gcc_assert (SYMBOL_REF_BLOCK (symbol));
6712 if (SYMBOL_REF_BLOCK_OFFSET (symbol) >= 0)
6713 return;
6715 /* Work out the symbol's size and alignment. */
6716 if (CONSTANT_POOL_ADDRESS_P (symbol))
6718 desc = SYMBOL_REF_CONSTANT (symbol);
6719 alignment = desc->align;
6720 size = GET_MODE_SIZE (desc->mode);
6722 else if (TREE_CONSTANT_POOL_ADDRESS_P (symbol))
6724 decl = SYMBOL_REF_DECL (symbol);
6725 alignment = get_constant_alignment (decl);
6726 size = get_constant_size (decl);
6728 else
6730 decl = SYMBOL_REF_DECL (symbol);
6731 alignment = DECL_ALIGN (decl);
6732 size = tree_low_cst (DECL_SIZE_UNIT (decl), 1);
6735 /* Calculate the object's offset from the start of the block. */
6736 block = SYMBOL_REF_BLOCK (symbol);
6737 mask = alignment / BITS_PER_UNIT - 1;
6738 offset = (block->size + mask) & ~mask;
6739 SYMBOL_REF_BLOCK_OFFSET (symbol) = offset;
6741 /* Record the block's new alignment and size. */
6742 block->alignment = MAX (block->alignment, alignment);
6743 block->size = offset + size;
6745 VEC_safe_push (rtx, gc, block->objects, symbol);
6748 /* Return the anchor that should be used to address byte offset OFFSET
6749 from the first object in BLOCK. MODEL is the TLS model used
6750 to access it. */
6753 get_section_anchor (struct object_block *block, HOST_WIDE_INT offset,
6754 enum tls_model model)
6756 char label[100];
6757 unsigned int begin, middle, end;
6758 unsigned HOST_WIDE_INT min_offset, max_offset, range, bias, delta;
6759 rtx anchor;
6761 /* Work out the anchor's offset. Use an offset of 0 for the first
6762 anchor so that we don't pessimize the case where we take the address
6763 of a variable at the beginning of the block. This is particularly
6764 useful when a block has only one variable assigned to it.
6766 We try to place anchors RANGE bytes apart, so there can then be
6767 anchors at +/-RANGE, +/-2 * RANGE, and so on, up to the limits of
6768 a ptr_mode offset. With some target settings, the lowest such
6769 anchor might be out of range for the lowest ptr_mode offset;
6770 likewise the highest anchor for the highest offset. Use anchors
6771 at the extreme ends of the ptr_mode range in such cases.
6773 All arithmetic uses unsigned integers in order to avoid
6774 signed overflow. */
6775 max_offset = (unsigned HOST_WIDE_INT) targetm.max_anchor_offset;
6776 min_offset = (unsigned HOST_WIDE_INT) targetm.min_anchor_offset;
6777 range = max_offset - min_offset + 1;
6778 if (range == 0)
6779 offset = 0;
6780 else
6782 bias = 1 << (GET_MODE_BITSIZE (ptr_mode) - 1);
6783 if (offset < 0)
6785 delta = -(unsigned HOST_WIDE_INT) offset + max_offset;
6786 delta -= delta % range;
6787 if (delta > bias)
6788 delta = bias;
6789 offset = (HOST_WIDE_INT) (-delta);
6791 else
6793 delta = (unsigned HOST_WIDE_INT) offset - min_offset;
6794 delta -= delta % range;
6795 if (delta > bias - 1)
6796 delta = bias - 1;
6797 offset = (HOST_WIDE_INT) delta;
6801 /* Do a binary search to see if there's already an anchor we can use.
6802 Set BEGIN to the new anchor's index if not. */
6803 begin = 0;
6804 end = VEC_length (rtx, block->anchors);
6805 while (begin != end)
6807 middle = (end + begin) / 2;
6808 anchor = VEC_index (rtx, block->anchors, middle);
6809 if (SYMBOL_REF_BLOCK_OFFSET (anchor) > offset)
6810 end = middle;
6811 else if (SYMBOL_REF_BLOCK_OFFSET (anchor) < offset)
6812 begin = middle + 1;
6813 else if (SYMBOL_REF_TLS_MODEL (anchor) > model)
6814 end = middle;
6815 else if (SYMBOL_REF_TLS_MODEL (anchor) < model)
6816 begin = middle + 1;
6817 else
6818 return anchor;
6821 /* Create a new anchor with a unique label. */
6822 ASM_GENERATE_INTERNAL_LABEL (label, "LANCHOR", anchor_labelno++);
6823 anchor = create_block_symbol (ggc_strdup (label), block, offset);
6824 SYMBOL_REF_FLAGS (anchor) |= SYMBOL_FLAG_LOCAL | SYMBOL_FLAG_ANCHOR;
6825 SYMBOL_REF_FLAGS (anchor) |= model << SYMBOL_FLAG_TLS_SHIFT;
6827 /* Insert it at index BEGIN. */
6828 VEC_safe_insert (rtx, gc, block->anchors, begin, anchor);
6829 return anchor;
6832 /* Output the objects in BLOCK. */
6834 static void
6835 output_object_block (struct object_block *block)
6837 struct constant_descriptor_rtx *desc;
6838 unsigned int i;
6839 HOST_WIDE_INT offset;
6840 tree decl;
6841 rtx symbol;
6843 if (block->objects == NULL)
6844 return;
6846 /* Switch to the section and make sure that the first byte is
6847 suitably aligned. */
6848 switch_to_section (block->sect);
6849 assemble_align (block->alignment);
6851 /* Define the values of all anchors relative to the current section
6852 position. */
6853 for (i = 0; VEC_iterate (rtx, block->anchors, i, symbol); i++)
6854 targetm.asm_out.output_anchor (symbol);
6856 /* Output the objects themselves. */
6857 offset = 0;
6858 for (i = 0; VEC_iterate (rtx, block->objects, i, symbol); i++)
6860 /* Move to the object's offset, padding with zeros if necessary. */
6861 assemble_zeros (SYMBOL_REF_BLOCK_OFFSET (symbol) - offset);
6862 offset = SYMBOL_REF_BLOCK_OFFSET (symbol);
6863 if (CONSTANT_POOL_ADDRESS_P (symbol))
6865 desc = SYMBOL_REF_CONSTANT (symbol);
6866 output_constant_pool_1 (desc, 1);
6867 offset += GET_MODE_SIZE (desc->mode);
6869 else if (TREE_CONSTANT_POOL_ADDRESS_P (symbol))
6871 decl = SYMBOL_REF_DECL (symbol);
6872 assemble_constant_contents (decl, XSTR (symbol, 0),
6873 get_constant_alignment (decl));
6874 offset += get_constant_size (decl);
6876 else
6878 decl = SYMBOL_REF_DECL (symbol);
6879 assemble_variable_contents (decl, XSTR (symbol, 0), false);
6880 offset += tree_low_cst (DECL_SIZE_UNIT (decl), 1);
6885 /* A htab_traverse callback used to call output_object_block for
6886 each member of object_block_htab. */
6888 static int
6889 output_object_block_htab (void **slot, void *data ATTRIBUTE_UNUSED)
6891 output_object_block ((struct object_block *) (*slot));
6892 return 1;
6895 /* Output the definitions of all object_blocks. */
6897 void
6898 output_object_blocks (void)
6900 htab_traverse (object_block_htab, output_object_block_htab, NULL);
6903 /* This function provides a possible implementation of the
6904 TARGET_ASM_RECORD_GCC_SWITCHES target hook for ELF targets. When triggered
6905 by -frecord-gcc-switches it creates a new mergeable, string section in the
6906 assembler output file called TARGET_ASM_RECORD_GCC_SWITCHES_SECTION which
6907 contains the switches in ASCII format.
6909 FIXME: This code does not correctly handle double quote characters
6910 that appear inside strings, (it strips them rather than preserving them).
6911 FIXME: ASM_OUTPUT_ASCII, as defined in config/elfos.h will not emit NUL
6912 characters - instead it treats them as sub-string separators. Since
6913 we want to emit NUL strings terminators into the object file we have to use
6914 ASM_OUTPUT_SKIP. */
6917 elf_record_gcc_switches (print_switch_type type, const char * name)
6919 static char buffer[1024];
6921 /* This variable is used as part of a simplistic heuristic to detect
6922 command line switches which take an argument:
6924 "If a command line option does not start with a dash then
6925 it is an argument for the previous command line option."
6927 This fails in the case of the command line option which is the name
6928 of the file to compile, but otherwise it is pretty reasonable. */
6929 static bool previous_name_held_back = FALSE;
6931 switch (type)
6933 case SWITCH_TYPE_PASSED:
6934 if (* name != '-')
6936 if (previous_name_held_back)
6938 unsigned int len = strlen (buffer);
6940 snprintf (buffer + len, sizeof buffer - len, " %s", name);
6941 ASM_OUTPUT_ASCII (asm_out_file, buffer, strlen (buffer));
6942 ASM_OUTPUT_SKIP (asm_out_file, (unsigned HOST_WIDE_INT) 1);
6943 previous_name_held_back = FALSE;
6945 else
6947 strncpy (buffer, name, sizeof buffer);
6948 ASM_OUTPUT_ASCII (asm_out_file, buffer, strlen (buffer));
6949 ASM_OUTPUT_SKIP (asm_out_file, (unsigned HOST_WIDE_INT) 1);
6952 else
6954 if (previous_name_held_back)
6956 ASM_OUTPUT_ASCII (asm_out_file, buffer, strlen (buffer));
6957 ASM_OUTPUT_SKIP (asm_out_file, (unsigned HOST_WIDE_INT) 1);
6960 strncpy (buffer, name, sizeof buffer);
6961 previous_name_held_back = TRUE;
6963 break;
6965 case SWITCH_TYPE_DESCRIPTIVE:
6966 if (name == NULL)
6968 /* Distinguish between invocations where name is NULL. */
6969 static bool started = false;
6971 if (started)
6973 if (previous_name_held_back)
6975 ASM_OUTPUT_ASCII (asm_out_file, buffer, strlen (buffer));
6976 ASM_OUTPUT_SKIP (asm_out_file, (unsigned HOST_WIDE_INT) 1);
6979 else
6981 section * sec;
6983 sec = get_section (targetm.asm_out.record_gcc_switches_section,
6984 SECTION_DEBUG
6985 | SECTION_MERGE
6986 | SECTION_STRINGS
6987 | (SECTION_ENTSIZE & 1),
6988 NULL);
6989 switch_to_section (sec);
6990 started = true;
6994 default:
6995 break;
6998 /* The return value is currently ignored by the caller, but must be 0.
6999 For -fverbose-asm the return value would be the number of characters
7000 emitted into the assembler file. */
7001 return 0;
7004 /* Emit text to declare externally defined symbols. It is needed to
7005 properly support non-default visibility. */
7006 void
7007 default_elf_asm_output_external (FILE *file ATTRIBUTE_UNUSED,
7008 tree decl,
7009 const char *name ATTRIBUTE_UNUSED)
7011 /* We output the name if and only if TREE_SYMBOL_REFERENCED is
7012 set in order to avoid putting out names that are never really
7013 used. */
7014 if (TREE_SYMBOL_REFERENCED (DECL_ASSEMBLER_NAME (decl))
7015 && targetm.binds_local_p (decl))
7016 maybe_assemble_visibility (decl);
7019 #include "gt-varasm.h"