PR middle-end/41357
[official-gcc.git] / gcc / varasm.c
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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 if (!DECL_IGNORED_P (decl))
1753 (*debug_hooks->begin_function) (decl);
1755 /* Make function name accessible from other files, if appropriate. */
1757 if (TREE_PUBLIC (decl))
1759 notice_global_symbol (decl);
1761 globalize_decl (decl);
1763 maybe_assemble_visibility (decl);
1766 if (DECL_PRESERVE_P (decl))
1767 targetm.asm_out.mark_decl_preserved (fnname);
1769 /* Do any machine/system dependent processing of the function name. */
1770 #ifdef ASM_DECLARE_FUNCTION_NAME
1771 ASM_DECLARE_FUNCTION_NAME (asm_out_file, fnname, current_function_decl);
1772 #else
1773 /* Standard thing is just output label for the function. */
1774 ASM_OUTPUT_LABEL (asm_out_file, fnname);
1775 #endif /* ASM_DECLARE_FUNCTION_NAME */
1778 /* Output assembler code associated with defining the size of the
1779 function. DECL describes the function. NAME is the function's name. */
1781 void
1782 assemble_end_function (tree decl, const char *fnname ATTRIBUTE_UNUSED)
1784 #ifdef ASM_DECLARE_FUNCTION_SIZE
1785 /* We could have switched section in the middle of the function. */
1786 if (flag_reorder_blocks_and_partition)
1787 switch_to_section (function_section (decl));
1788 ASM_DECLARE_FUNCTION_SIZE (asm_out_file, fnname, decl);
1789 #endif
1790 if (! CONSTANT_POOL_BEFORE_FUNCTION)
1792 output_constant_pool (fnname, decl);
1793 switch_to_section (function_section (decl)); /* need to switch back */
1795 /* Output labels for end of hot/cold text sections (to be used by
1796 debug info.) */
1797 if (flag_reorder_blocks_and_partition)
1799 section *save_text_section;
1801 save_text_section = in_section;
1802 switch_to_section (unlikely_text_section ());
1803 ASM_OUTPUT_LABEL (asm_out_file, crtl->subsections.cold_section_end_label);
1804 if (first_function_block_is_cold)
1805 switch_to_section (text_section);
1806 else
1807 switch_to_section (function_section (decl));
1808 ASM_OUTPUT_LABEL (asm_out_file, crtl->subsections.hot_section_end_label);
1809 switch_to_section (save_text_section);
1813 /* Assemble code to leave SIZE bytes of zeros. */
1815 void
1816 assemble_zeros (unsigned HOST_WIDE_INT size)
1818 /* Do no output if -fsyntax-only. */
1819 if (flag_syntax_only)
1820 return;
1822 #ifdef ASM_NO_SKIP_IN_TEXT
1823 /* The `space' pseudo in the text section outputs nop insns rather than 0s,
1824 so we must output 0s explicitly in the text section. */
1825 if (ASM_NO_SKIP_IN_TEXT && (in_section->common.flags & SECTION_CODE) != 0)
1827 unsigned HOST_WIDE_INT i;
1828 for (i = 0; i < size; i++)
1829 assemble_integer (const0_rtx, 1, BITS_PER_UNIT, 1);
1831 else
1832 #endif
1833 if (size > 0)
1834 ASM_OUTPUT_SKIP (asm_out_file, size);
1837 /* Assemble an alignment pseudo op for an ALIGN-bit boundary. */
1839 void
1840 assemble_align (int align)
1842 if (align > BITS_PER_UNIT)
1844 ASM_OUTPUT_ALIGN (asm_out_file, floor_log2 (align / BITS_PER_UNIT));
1848 /* Assemble a string constant with the specified C string as contents. */
1850 void
1851 assemble_string (const char *p, int size)
1853 int pos = 0;
1854 int maximum = 2000;
1856 /* If the string is very long, split it up. */
1858 while (pos < size)
1860 int thissize = size - pos;
1861 if (thissize > maximum)
1862 thissize = maximum;
1864 ASM_OUTPUT_ASCII (asm_out_file, p, thissize);
1866 pos += thissize;
1867 p += thissize;
1872 /* A noswitch_section_callback for lcomm_section. */
1874 static bool
1875 emit_local (tree decl ATTRIBUTE_UNUSED,
1876 const char *name ATTRIBUTE_UNUSED,
1877 unsigned HOST_WIDE_INT size ATTRIBUTE_UNUSED,
1878 unsigned HOST_WIDE_INT rounded ATTRIBUTE_UNUSED)
1880 #if defined ASM_OUTPUT_ALIGNED_DECL_LOCAL
1881 ASM_OUTPUT_ALIGNED_DECL_LOCAL (asm_out_file, decl, name,
1882 size, DECL_ALIGN (decl));
1883 return true;
1884 #elif defined ASM_OUTPUT_ALIGNED_LOCAL
1885 ASM_OUTPUT_ALIGNED_LOCAL (asm_out_file, name, size, DECL_ALIGN (decl));
1886 return true;
1887 #else
1888 ASM_OUTPUT_LOCAL (asm_out_file, name, size, rounded);
1889 return false;
1890 #endif
1893 /* A noswitch_section_callback for bss_noswitch_section. */
1895 #if defined ASM_OUTPUT_ALIGNED_BSS || defined ASM_OUTPUT_BSS
1896 static bool
1897 emit_bss (tree decl ATTRIBUTE_UNUSED,
1898 const char *name ATTRIBUTE_UNUSED,
1899 unsigned HOST_WIDE_INT size ATTRIBUTE_UNUSED,
1900 unsigned HOST_WIDE_INT rounded ATTRIBUTE_UNUSED)
1902 #if defined ASM_OUTPUT_ALIGNED_BSS
1903 ASM_OUTPUT_ALIGNED_BSS (asm_out_file, decl, name, size, DECL_ALIGN (decl));
1904 return true;
1905 #else
1906 ASM_OUTPUT_BSS (asm_out_file, decl, name, size, rounded);
1907 return false;
1908 #endif
1910 #endif
1912 /* A noswitch_section_callback for comm_section. */
1914 static bool
1915 emit_common (tree decl ATTRIBUTE_UNUSED,
1916 const char *name ATTRIBUTE_UNUSED,
1917 unsigned HOST_WIDE_INT size ATTRIBUTE_UNUSED,
1918 unsigned HOST_WIDE_INT rounded ATTRIBUTE_UNUSED)
1920 #if defined ASM_OUTPUT_ALIGNED_DECL_COMMON
1921 ASM_OUTPUT_ALIGNED_DECL_COMMON (asm_out_file, decl, name,
1922 size, DECL_ALIGN (decl));
1923 return true;
1924 #elif defined ASM_OUTPUT_ALIGNED_COMMON
1925 ASM_OUTPUT_ALIGNED_COMMON (asm_out_file, name, size, DECL_ALIGN (decl));
1926 return true;
1927 #else
1928 ASM_OUTPUT_COMMON (asm_out_file, name, size, rounded);
1929 return false;
1930 #endif
1933 /* A noswitch_section_callback for tls_comm_section. */
1935 static bool
1936 emit_tls_common (tree decl ATTRIBUTE_UNUSED,
1937 const char *name ATTRIBUTE_UNUSED,
1938 unsigned HOST_WIDE_INT size ATTRIBUTE_UNUSED,
1939 unsigned HOST_WIDE_INT rounded ATTRIBUTE_UNUSED)
1941 #ifdef ASM_OUTPUT_TLS_COMMON
1942 ASM_OUTPUT_TLS_COMMON (asm_out_file, decl, name, size);
1943 return true;
1944 #else
1945 sorry ("thread-local COMMON data not implemented");
1946 return true;
1947 #endif
1950 /* Assemble DECL given that it belongs in SECTION_NOSWITCH section SECT.
1951 NAME is the name of DECL's SYMBOL_REF. */
1953 static void
1954 assemble_noswitch_variable (tree decl, const char *name, section *sect)
1956 unsigned HOST_WIDE_INT size, rounded;
1958 size = tree_low_cst (DECL_SIZE_UNIT (decl), 1);
1959 rounded = size;
1961 /* Don't allocate zero bytes of common,
1962 since that means "undefined external" in the linker. */
1963 if (size == 0)
1964 rounded = 1;
1966 /* Round size up to multiple of BIGGEST_ALIGNMENT bits
1967 so that each uninitialized object starts on such a boundary. */
1968 rounded += (BIGGEST_ALIGNMENT / BITS_PER_UNIT) - 1;
1969 rounded = (rounded / (BIGGEST_ALIGNMENT / BITS_PER_UNIT)
1970 * (BIGGEST_ALIGNMENT / BITS_PER_UNIT));
1972 if (!sect->noswitch.callback (decl, name, size, rounded)
1973 && (unsigned HOST_WIDE_INT) DECL_ALIGN_UNIT (decl) > rounded)
1974 warning (0, "requested alignment for %q+D is greater than "
1975 "implemented alignment of %wu", decl, rounded);
1978 /* A subroutine of assemble_variable. Output the label and contents of
1979 DECL, whose address is a SYMBOL_REF with name NAME. DONT_OUTPUT_DATA
1980 is as for assemble_variable. */
1982 static void
1983 assemble_variable_contents (tree decl, const char *name,
1984 bool dont_output_data)
1986 /* Do any machine/system dependent processing of the object. */
1987 #ifdef ASM_DECLARE_OBJECT_NAME
1988 last_assemble_variable_decl = decl;
1989 ASM_DECLARE_OBJECT_NAME (asm_out_file, name, decl);
1990 #else
1991 /* Standard thing is just output label for the object. */
1992 ASM_OUTPUT_LABEL (asm_out_file, name);
1993 #endif /* ASM_DECLARE_OBJECT_NAME */
1995 if (!dont_output_data)
1997 if (DECL_INITIAL (decl)
1998 && DECL_INITIAL (decl) != error_mark_node
1999 && !initializer_zerop (DECL_INITIAL (decl)))
2000 /* Output the actual data. */
2001 output_constant (DECL_INITIAL (decl),
2002 tree_low_cst (DECL_SIZE_UNIT (decl), 1),
2003 DECL_ALIGN (decl));
2004 else
2005 /* Leave space for it. */
2006 assemble_zeros (tree_low_cst (DECL_SIZE_UNIT (decl), 1));
2010 /* Initialize emulated tls object TO, which refers to TLS variable
2011 DECL and is initialized by PROXY. */
2013 tree
2014 default_emutls_var_init (tree to, tree decl, tree proxy)
2016 VEC(constructor_elt,gc) *v = VEC_alloc (constructor_elt, gc, 4);
2017 constructor_elt *elt;
2018 tree type = TREE_TYPE (to);
2019 tree field = TYPE_FIELDS (type);
2021 elt = VEC_quick_push (constructor_elt, v, NULL);
2022 elt->index = field;
2023 elt->value = fold_convert (TREE_TYPE (field), DECL_SIZE_UNIT (decl));
2025 elt = VEC_quick_push (constructor_elt, v, NULL);
2026 field = TREE_CHAIN (field);
2027 elt->index = field;
2028 elt->value = build_int_cst (TREE_TYPE (field),
2029 DECL_ALIGN_UNIT (decl));
2031 elt = VEC_quick_push (constructor_elt, v, NULL);
2032 field = TREE_CHAIN (field);
2033 elt->index = field;
2034 elt->value = null_pointer_node;
2036 elt = VEC_quick_push (constructor_elt, v, NULL);
2037 field = TREE_CHAIN (field);
2038 elt->index = field;
2039 elt->value = proxy;
2041 return build_constructor (type, v);
2044 /* Assemble everything that is needed for a variable or function declaration.
2045 Not used for automatic variables, and not used for function definitions.
2046 Should not be called for variables of incomplete structure type.
2048 TOP_LEVEL is nonzero if this variable has file scope.
2049 AT_END is nonzero if this is the special handling, at end of compilation,
2050 to define things that have had only tentative definitions.
2051 DONT_OUTPUT_DATA if nonzero means don't actually output the
2052 initial value (that will be done by the caller). */
2054 void
2055 assemble_variable (tree decl, int top_level ATTRIBUTE_UNUSED,
2056 int at_end ATTRIBUTE_UNUSED, int dont_output_data)
2058 const char *name;
2059 rtx decl_rtl, symbol;
2060 section *sect;
2062 if (! targetm.have_tls
2063 && TREE_CODE (decl) == VAR_DECL
2064 && DECL_THREAD_LOCAL_P (decl))
2066 tree to = emutls_decl (decl);
2068 /* If this variable is defined locally, then we need to initialize the
2069 control structure with size and alignment information. We do this
2070 at the last moment because tentative definitions can take a locally
2071 defined but uninitialized variable and initialize it later, which
2072 would result in incorrect contents. */
2073 if (! DECL_EXTERNAL (to)
2074 && (! DECL_COMMON (to)
2075 || (DECL_INITIAL (decl)
2076 && DECL_INITIAL (decl) != error_mark_node)))
2078 DECL_INITIAL (to) = targetm.emutls.var_init
2079 (to, decl, get_emutls_init_templ_addr (decl));
2081 /* Make sure the template is marked as needed early enough.
2082 Without this, if the variable is placed in a
2083 section-anchored block, the template will only be marked
2084 when it's too late. */
2085 record_references_in_initializer (to);
2088 decl = to;
2091 last_assemble_variable_decl = 0;
2093 /* Normally no need to say anything here for external references,
2094 since assemble_external is called by the language-specific code
2095 when a declaration is first seen. */
2097 if (DECL_EXTERNAL (decl))
2098 return;
2100 /* Output no assembler code for a function declaration.
2101 Only definitions of functions output anything. */
2103 if (TREE_CODE (decl) == FUNCTION_DECL)
2104 return;
2106 /* Do nothing for global register variables. */
2107 if (DECL_RTL_SET_P (decl) && REG_P (DECL_RTL (decl)))
2109 TREE_ASM_WRITTEN (decl) = 1;
2110 return;
2113 /* If type was incomplete when the variable was declared,
2114 see if it is complete now. */
2116 if (DECL_SIZE (decl) == 0)
2117 layout_decl (decl, 0);
2119 /* Still incomplete => don't allocate it; treat the tentative defn
2120 (which is what it must have been) as an `extern' reference. */
2122 if (!dont_output_data && DECL_SIZE (decl) == 0)
2124 error ("storage size of %q+D isn%'t known", decl);
2125 TREE_ASM_WRITTEN (decl) = 1;
2126 return;
2129 /* The first declaration of a variable that comes through this function
2130 decides whether it is global (in C, has external linkage)
2131 or local (in C, has internal linkage). So do nothing more
2132 if this function has already run. */
2134 if (TREE_ASM_WRITTEN (decl))
2135 return;
2137 /* Make sure targetm.encode_section_info is invoked before we set
2138 ASM_WRITTEN. */
2139 decl_rtl = DECL_RTL (decl);
2141 TREE_ASM_WRITTEN (decl) = 1;
2143 /* Do no output if -fsyntax-only. */
2144 if (flag_syntax_only)
2145 return;
2147 app_disable ();
2149 if (! dont_output_data
2150 && ! host_integerp (DECL_SIZE_UNIT (decl), 1))
2152 error ("size of variable %q+D is too large", decl);
2153 return;
2156 gcc_assert (MEM_P (decl_rtl));
2157 gcc_assert (GET_CODE (XEXP (decl_rtl, 0)) == SYMBOL_REF);
2158 symbol = XEXP (decl_rtl, 0);
2159 name = XSTR (symbol, 0);
2160 if (TREE_PUBLIC (decl) && DECL_NAME (decl))
2161 notice_global_symbol (decl);
2163 /* Compute the alignment of this data. */
2165 align_variable (decl, dont_output_data);
2166 set_mem_align (decl_rtl, DECL_ALIGN (decl));
2168 if (TREE_PUBLIC (decl))
2169 maybe_assemble_visibility (decl);
2171 if (DECL_PRESERVE_P (decl))
2172 targetm.asm_out.mark_decl_preserved (name);
2174 /* First make the assembler name(s) global if appropriate. */
2175 sect = get_variable_section (decl, false);
2176 if (TREE_PUBLIC (decl)
2177 && (sect->common.flags & SECTION_COMMON) == 0)
2178 globalize_decl (decl);
2180 /* Output any data that we will need to use the address of. */
2181 if (DECL_INITIAL (decl) && DECL_INITIAL (decl) != error_mark_node)
2182 output_addressed_constants (DECL_INITIAL (decl));
2184 /* dbxout.c needs to know this. */
2185 if (sect && (sect->common.flags & SECTION_CODE) != 0)
2186 DECL_IN_TEXT_SECTION (decl) = 1;
2188 /* If the decl is part of an object_block, make sure that the decl
2189 has been positioned within its block, but do not write out its
2190 definition yet. output_object_blocks will do that later. */
2191 if (SYMBOL_REF_HAS_BLOCK_INFO_P (symbol) && SYMBOL_REF_BLOCK (symbol))
2193 gcc_assert (!dont_output_data);
2194 place_block_symbol (symbol);
2196 else if (SECTION_STYLE (sect) == SECTION_NOSWITCH)
2197 assemble_noswitch_variable (decl, name, sect);
2198 else
2200 switch_to_section (sect);
2201 if (DECL_ALIGN (decl) > BITS_PER_UNIT)
2202 ASM_OUTPUT_ALIGN (asm_out_file, floor_log2 (DECL_ALIGN_UNIT (decl)));
2203 assemble_variable_contents (decl, name, dont_output_data);
2207 /* Return 1 if type TYPE contains any pointers. */
2209 static int
2210 contains_pointers_p (tree type)
2212 switch (TREE_CODE (type))
2214 case POINTER_TYPE:
2215 case REFERENCE_TYPE:
2216 /* I'm not sure whether OFFSET_TYPE needs this treatment,
2217 so I'll play safe and return 1. */
2218 case OFFSET_TYPE:
2219 return 1;
2221 case RECORD_TYPE:
2222 case UNION_TYPE:
2223 case QUAL_UNION_TYPE:
2225 tree fields;
2226 /* For a type that has fields, see if the fields have pointers. */
2227 for (fields = TYPE_FIELDS (type); fields; fields = TREE_CHAIN (fields))
2228 if (TREE_CODE (fields) == FIELD_DECL
2229 && contains_pointers_p (TREE_TYPE (fields)))
2230 return 1;
2231 return 0;
2234 case ARRAY_TYPE:
2235 /* An array type contains pointers if its element type does. */
2236 return contains_pointers_p (TREE_TYPE (type));
2238 default:
2239 return 0;
2243 /* We delay assemble_external processing until
2244 the compilation unit is finalized. This is the best we can do for
2245 right now (i.e. stage 3 of GCC 4.0) - the right thing is to delay
2246 it all the way to final. See PR 17982 for further discussion. */
2247 static GTY(()) tree pending_assemble_externals;
2249 #ifdef ASM_OUTPUT_EXTERNAL
2250 /* True if DECL is a function decl for which no out-of-line copy exists.
2251 It is assumed that DECL's assembler name has been set. */
2253 static bool
2254 incorporeal_function_p (tree decl)
2256 if (TREE_CODE (decl) == FUNCTION_DECL && DECL_BUILT_IN (decl))
2258 const char *name;
2260 if (DECL_BUILT_IN_CLASS (decl) == BUILT_IN_NORMAL
2261 && DECL_FUNCTION_CODE (decl) == BUILT_IN_ALLOCA)
2262 return true;
2264 name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
2265 if (is_builtin_name (name))
2266 return true;
2268 return false;
2271 /* Actually do the tests to determine if this is necessary, and invoke
2272 ASM_OUTPUT_EXTERNAL. */
2273 static void
2274 assemble_external_real (tree decl)
2276 rtx rtl = DECL_RTL (decl);
2278 if (MEM_P (rtl) && GET_CODE (XEXP (rtl, 0)) == SYMBOL_REF
2279 && !SYMBOL_REF_USED (XEXP (rtl, 0))
2280 && !incorporeal_function_p (decl))
2282 /* Some systems do require some output. */
2283 SYMBOL_REF_USED (XEXP (rtl, 0)) = 1;
2284 ASM_OUTPUT_EXTERNAL (asm_out_file, decl, XSTR (XEXP (rtl, 0), 0));
2287 #endif
2289 void
2290 process_pending_assemble_externals (void)
2292 #ifdef ASM_OUTPUT_EXTERNAL
2293 tree list;
2294 for (list = pending_assemble_externals; list; list = TREE_CHAIN (list))
2295 assemble_external_real (TREE_VALUE (list));
2297 pending_assemble_externals = 0;
2298 #endif
2301 /* This TREE_LIST contains any weak symbol declarations waiting
2302 to be emitted. */
2303 static GTY(()) tree weak_decls;
2305 /* Output something to declare an external symbol to the assembler,
2306 and qualifiers such as weakness. (Most assemblers don't need
2307 extern declaration, so we normally output nothing.) Do nothing if
2308 DECL is not external. */
2310 void
2311 assemble_external (tree decl ATTRIBUTE_UNUSED)
2313 /* Because most platforms do not define ASM_OUTPUT_EXTERNAL, the
2314 main body of this code is only rarely exercised. To provide some
2315 testing, on all platforms, we make sure that the ASM_OUT_FILE is
2316 open. If it's not, we should not be calling this function. */
2317 gcc_assert (asm_out_file);
2319 if (!DECL_P (decl) || !DECL_EXTERNAL (decl) || !TREE_PUBLIC (decl))
2320 return;
2322 /* We want to output annotation for weak and external symbols at
2323 very last to check if they are references or not. */
2325 if (SUPPORTS_WEAK && DECL_WEAK (decl)
2326 /* TREE_STATIC is a weird and abused creature which is not
2327 generally the right test for whether an entity has been
2328 locally emitted, inlined or otherwise not-really-extern, but
2329 for declarations that can be weak, it happens to be
2330 match. */
2331 && !TREE_STATIC (decl)
2332 && value_member (decl, weak_decls) == NULL_TREE)
2333 weak_decls = tree_cons (NULL, decl, weak_decls);
2335 #ifdef ASM_OUTPUT_EXTERNAL
2336 if (value_member (decl, pending_assemble_externals) == NULL_TREE)
2337 pending_assemble_externals = tree_cons (NULL, decl,
2338 pending_assemble_externals);
2339 #endif
2342 /* Similar, for calling a library function FUN. */
2344 void
2345 assemble_external_libcall (rtx fun)
2347 /* Declare library function name external when first used, if nec. */
2348 if (! SYMBOL_REF_USED (fun))
2350 SYMBOL_REF_USED (fun) = 1;
2351 targetm.asm_out.external_libcall (fun);
2355 /* Assemble a label named NAME. */
2357 void
2358 assemble_label (const char *name)
2360 ASM_OUTPUT_LABEL (asm_out_file, name);
2363 /* Set the symbol_referenced flag for ID. */
2364 void
2365 mark_referenced (tree id)
2367 TREE_SYMBOL_REFERENCED (id) = 1;
2370 /* Set the symbol_referenced flag for DECL and notify callgraph. */
2371 void
2372 mark_decl_referenced (tree decl)
2374 if (TREE_CODE (decl) == FUNCTION_DECL)
2376 /* Extern inline functions don't become needed when referenced.
2377 If we know a method will be emitted in other TU and no new
2378 functions can be marked reachable, just use the external
2379 definition. */
2380 struct cgraph_node *node = cgraph_node (decl);
2381 if (!DECL_EXTERNAL (decl)
2382 && (!node->local.vtable_method || !cgraph_global_info_ready
2383 || !node->local.finalized))
2384 cgraph_mark_needed_node (node);
2386 else if (TREE_CODE (decl) == VAR_DECL)
2388 struct varpool_node *node = varpool_node (decl);
2389 varpool_mark_needed_node (node);
2390 /* C++ frontend use mark_decl_references to force COMDAT variables
2391 to be output that might appear dead otherwise. */
2392 node->force_output = true;
2394 /* else do nothing - we can get various sorts of CST nodes here,
2395 which do not need to be marked. */
2399 /* Follow the IDENTIFIER_TRANSPARENT_ALIAS chain starting at *ALIAS
2400 until we find an identifier that is not itself a transparent alias.
2401 Modify the alias passed to it by reference (and all aliases on the
2402 way to the ultimate target), such that they do not have to be
2403 followed again, and return the ultimate target of the alias
2404 chain. */
2406 static inline tree
2407 ultimate_transparent_alias_target (tree *alias)
2409 tree target = *alias;
2411 if (IDENTIFIER_TRANSPARENT_ALIAS (target))
2413 gcc_assert (TREE_CHAIN (target));
2414 target = ultimate_transparent_alias_target (&TREE_CHAIN (target));
2415 gcc_assert (! IDENTIFIER_TRANSPARENT_ALIAS (target)
2416 && ! TREE_CHAIN (target));
2417 *alias = target;
2420 return target;
2423 /* Output to FILE (an assembly file) a reference to NAME. If NAME
2424 starts with a *, the rest of NAME is output verbatim. Otherwise
2425 NAME is transformed in a target-specific way (usually by the
2426 addition of an underscore). */
2428 void
2429 assemble_name_raw (FILE *file, const char *name)
2431 if (name[0] == '*')
2432 fputs (&name[1], file);
2433 else
2434 ASM_OUTPUT_LABELREF (file, name);
2437 /* Like assemble_name_raw, but should be used when NAME might refer to
2438 an entity that is also represented as a tree (like a function or
2439 variable). If NAME does refer to such an entity, that entity will
2440 be marked as referenced. */
2442 void
2443 assemble_name (FILE *file, const char *name)
2445 const char *real_name;
2446 tree id;
2448 real_name = targetm.strip_name_encoding (name);
2450 id = maybe_get_identifier (real_name);
2451 if (id)
2453 tree id_orig = id;
2455 mark_referenced (id);
2456 ultimate_transparent_alias_target (&id);
2457 if (id != id_orig)
2458 name = IDENTIFIER_POINTER (id);
2459 gcc_assert (! TREE_CHAIN (id));
2462 assemble_name_raw (file, name);
2465 /* Allocate SIZE bytes writable static space with a gensym name
2466 and return an RTX to refer to its address. */
2469 assemble_static_space (unsigned HOST_WIDE_INT size)
2471 char name[12];
2472 const char *namestring;
2473 rtx x;
2475 ASM_GENERATE_INTERNAL_LABEL (name, "LF", const_labelno);
2476 ++const_labelno;
2477 namestring = ggc_strdup (name);
2479 x = gen_rtx_SYMBOL_REF (Pmode, namestring);
2480 SYMBOL_REF_FLAGS (x) = SYMBOL_FLAG_LOCAL;
2482 #ifdef ASM_OUTPUT_ALIGNED_DECL_LOCAL
2483 ASM_OUTPUT_ALIGNED_DECL_LOCAL (asm_out_file, NULL_TREE, name, size,
2484 BIGGEST_ALIGNMENT);
2485 #else
2486 #ifdef ASM_OUTPUT_ALIGNED_LOCAL
2487 ASM_OUTPUT_ALIGNED_LOCAL (asm_out_file, name, size, BIGGEST_ALIGNMENT);
2488 #else
2490 /* Round size up to multiple of BIGGEST_ALIGNMENT bits
2491 so that each uninitialized object starts on such a boundary. */
2492 /* Variable `rounded' might or might not be used in ASM_OUTPUT_LOCAL. */
2493 unsigned HOST_WIDE_INT rounded ATTRIBUTE_UNUSED
2494 = ((size + (BIGGEST_ALIGNMENT / BITS_PER_UNIT) - 1)
2495 / (BIGGEST_ALIGNMENT / BITS_PER_UNIT)
2496 * (BIGGEST_ALIGNMENT / BITS_PER_UNIT));
2497 ASM_OUTPUT_LOCAL (asm_out_file, name, size, rounded);
2499 #endif
2500 #endif
2501 return x;
2504 /* Assemble the static constant template for function entry trampolines.
2505 This is done at most once per compilation.
2506 Returns an RTX for the address of the template. */
2508 static GTY(()) rtx initial_trampoline;
2510 #ifdef TRAMPOLINE_TEMPLATE
2512 assemble_trampoline_template (void)
2514 char label[256];
2515 const char *name;
2516 int align;
2517 rtx symbol;
2519 if (initial_trampoline)
2520 return initial_trampoline;
2522 /* By default, put trampoline templates in read-only data section. */
2524 #ifdef TRAMPOLINE_SECTION
2525 switch_to_section (TRAMPOLINE_SECTION);
2526 #else
2527 switch_to_section (readonly_data_section);
2528 #endif
2530 /* Write the assembler code to define one. */
2531 align = floor_log2 (TRAMPOLINE_ALIGNMENT / BITS_PER_UNIT);
2532 if (align > 0)
2534 ASM_OUTPUT_ALIGN (asm_out_file, align);
2537 targetm.asm_out.internal_label (asm_out_file, "LTRAMP", 0);
2538 TRAMPOLINE_TEMPLATE (asm_out_file);
2540 /* Record the rtl to refer to it. */
2541 ASM_GENERATE_INTERNAL_LABEL (label, "LTRAMP", 0);
2542 name = ggc_strdup (label);
2543 symbol = gen_rtx_SYMBOL_REF (Pmode, name);
2544 SYMBOL_REF_FLAGS (symbol) = SYMBOL_FLAG_LOCAL;
2546 initial_trampoline = gen_rtx_MEM (BLKmode, symbol);
2547 set_mem_align (initial_trampoline, TRAMPOLINE_ALIGNMENT);
2549 return initial_trampoline;
2551 #endif
2553 /* A and B are either alignments or offsets. Return the minimum alignment
2554 that may be assumed after adding the two together. */
2556 static inline unsigned
2557 min_align (unsigned int a, unsigned int b)
2559 return (a | b) & -(a | b);
2562 /* Return the assembler directive for creating a given kind of integer
2563 object. SIZE is the number of bytes in the object and ALIGNED_P
2564 indicates whether it is known to be aligned. Return NULL if the
2565 assembly dialect has no such directive.
2567 The returned string should be printed at the start of a new line and
2568 be followed immediately by the object's initial value. */
2570 const char *
2571 integer_asm_op (int size, int aligned_p)
2573 struct asm_int_op *ops;
2575 if (aligned_p)
2576 ops = &targetm.asm_out.aligned_op;
2577 else
2578 ops = &targetm.asm_out.unaligned_op;
2580 switch (size)
2582 case 1:
2583 return targetm.asm_out.byte_op;
2584 case 2:
2585 return ops->hi;
2586 case 4:
2587 return ops->si;
2588 case 8:
2589 return ops->di;
2590 case 16:
2591 return ops->ti;
2592 default:
2593 return NULL;
2597 /* Use directive OP to assemble an integer object X. Print OP at the
2598 start of the line, followed immediately by the value of X. */
2600 void
2601 assemble_integer_with_op (const char *op, rtx x)
2603 fputs (op, asm_out_file);
2604 output_addr_const (asm_out_file, x);
2605 fputc ('\n', asm_out_file);
2608 /* The default implementation of the asm_out.integer target hook. */
2610 bool
2611 default_assemble_integer (rtx x ATTRIBUTE_UNUSED,
2612 unsigned int size ATTRIBUTE_UNUSED,
2613 int aligned_p ATTRIBUTE_UNUSED)
2615 const char *op = integer_asm_op (size, aligned_p);
2616 /* Avoid GAS bugs for large values. Specifically negative values whose
2617 absolute value fits in a bfd_vma, but not in a bfd_signed_vma. */
2618 if (size > UNITS_PER_WORD && size > POINTER_SIZE / BITS_PER_UNIT)
2619 return false;
2620 return op && (assemble_integer_with_op (op, x), true);
2623 /* Assemble the integer constant X into an object of SIZE bytes. ALIGN is
2624 the alignment of the integer in bits. Return 1 if we were able to output
2625 the constant, otherwise 0. We must be able to output the constant,
2626 if FORCE is nonzero. */
2628 bool
2629 assemble_integer (rtx x, unsigned int size, unsigned int align, int force)
2631 int aligned_p;
2633 aligned_p = (align >= MIN (size * BITS_PER_UNIT, BIGGEST_ALIGNMENT));
2635 /* See if the target hook can handle this kind of object. */
2636 if (targetm.asm_out.integer (x, size, aligned_p))
2637 return true;
2639 /* If the object is a multi-byte one, try splitting it up. Split
2640 it into words it if is multi-word, otherwise split it into bytes. */
2641 if (size > 1)
2643 enum machine_mode omode, imode;
2644 unsigned int subalign;
2645 unsigned int subsize, i;
2646 enum mode_class mclass;
2648 subsize = size > UNITS_PER_WORD? UNITS_PER_WORD : 1;
2649 subalign = MIN (align, subsize * BITS_PER_UNIT);
2650 if (GET_CODE (x) == CONST_FIXED)
2651 mclass = GET_MODE_CLASS (GET_MODE (x));
2652 else
2653 mclass = MODE_INT;
2655 omode = mode_for_size (subsize * BITS_PER_UNIT, mclass, 0);
2656 imode = mode_for_size (size * BITS_PER_UNIT, mclass, 0);
2658 for (i = 0; i < size; i += subsize)
2660 rtx partial = simplify_subreg (omode, x, imode, i);
2661 if (!partial || !assemble_integer (partial, subsize, subalign, 0))
2662 break;
2664 if (i == size)
2665 return true;
2667 /* If we've printed some of it, but not all of it, there's no going
2668 back now. */
2669 gcc_assert (!i);
2672 gcc_assert (!force);
2674 return false;
2677 void
2678 assemble_real (REAL_VALUE_TYPE d, enum machine_mode mode, unsigned int align)
2680 long data[4] = {0, 0, 0, 0};
2681 int i;
2682 int bitsize, nelts, nunits, units_per;
2684 /* This is hairy. We have a quantity of known size. real_to_target
2685 will put it into an array of *host* longs, 32 bits per element
2686 (even if long is more than 32 bits). We need to determine the
2687 number of array elements that are occupied (nelts) and the number
2688 of *target* min-addressable units that will be occupied in the
2689 object file (nunits). We cannot assume that 32 divides the
2690 mode's bitsize (size * BITS_PER_UNIT) evenly.
2692 size * BITS_PER_UNIT is used here to make sure that padding bits
2693 (which might appear at either end of the value; real_to_target
2694 will include the padding bits in its output array) are included. */
2696 nunits = GET_MODE_SIZE (mode);
2697 bitsize = nunits * BITS_PER_UNIT;
2698 nelts = CEIL (bitsize, 32);
2699 units_per = 32 / BITS_PER_UNIT;
2701 real_to_target (data, &d, mode);
2703 /* Put out the first word with the specified alignment. */
2704 assemble_integer (GEN_INT (data[0]), MIN (nunits, units_per), align, 1);
2705 nunits -= units_per;
2707 /* Subsequent words need only 32-bit alignment. */
2708 align = min_align (align, 32);
2710 for (i = 1; i < nelts; i++)
2712 assemble_integer (GEN_INT (data[i]), MIN (nunits, units_per), align, 1);
2713 nunits -= units_per;
2717 /* Given an expression EXP with a constant value,
2718 reduce it to the sum of an assembler symbol and an integer.
2719 Store them both in the structure *VALUE.
2720 EXP must be reducible. */
2722 struct GTY(()) addr_const {
2723 rtx base;
2724 HOST_WIDE_INT offset;
2727 static void
2728 decode_addr_const (tree exp, struct addr_const *value)
2730 tree target = TREE_OPERAND (exp, 0);
2731 int offset = 0;
2732 rtx x;
2734 while (1)
2736 if (TREE_CODE (target) == COMPONENT_REF
2737 && host_integerp (byte_position (TREE_OPERAND (target, 1)), 0))
2740 offset += int_byte_position (TREE_OPERAND (target, 1));
2741 target = TREE_OPERAND (target, 0);
2743 else if (TREE_CODE (target) == ARRAY_REF
2744 || TREE_CODE (target) == ARRAY_RANGE_REF)
2746 offset += (tree_low_cst (TYPE_SIZE_UNIT (TREE_TYPE (target)), 1)
2747 * tree_low_cst (TREE_OPERAND (target, 1), 0));
2748 target = TREE_OPERAND (target, 0);
2750 else
2751 break;
2754 switch (TREE_CODE (target))
2756 case VAR_DECL:
2757 case FUNCTION_DECL:
2758 x = DECL_RTL (target);
2759 break;
2761 case LABEL_DECL:
2762 x = gen_rtx_MEM (FUNCTION_MODE,
2763 gen_rtx_LABEL_REF (Pmode, force_label_rtx (target)));
2764 break;
2766 case REAL_CST:
2767 case FIXED_CST:
2768 case STRING_CST:
2769 case COMPLEX_CST:
2770 case CONSTRUCTOR:
2771 case INTEGER_CST:
2772 x = output_constant_def (target, 1);
2773 break;
2775 default:
2776 gcc_unreachable ();
2779 gcc_assert (MEM_P (x));
2780 x = XEXP (x, 0);
2782 value->base = x;
2783 value->offset = offset;
2787 static GTY((param_is (struct constant_descriptor_tree)))
2788 htab_t const_desc_htab;
2790 static struct constant_descriptor_tree * build_constant_desc (tree);
2791 static void maybe_output_constant_def_contents (struct constant_descriptor_tree *, int);
2793 /* Constant pool accessor function. */
2795 htab_t
2796 constant_pool_htab (void)
2798 return const_desc_htab;
2801 /* Compute a hash code for a constant expression. */
2803 static hashval_t
2804 const_desc_hash (const void *ptr)
2806 return ((const struct constant_descriptor_tree *)ptr)->hash;
2809 static hashval_t
2810 const_hash_1 (const tree exp)
2812 const char *p;
2813 hashval_t hi;
2814 int len, i;
2815 enum tree_code code = TREE_CODE (exp);
2817 /* Either set P and LEN to the address and len of something to hash and
2818 exit the switch or return a value. */
2820 switch (code)
2822 case INTEGER_CST:
2823 p = (char *) &TREE_INT_CST (exp);
2824 len = sizeof TREE_INT_CST (exp);
2825 break;
2827 case REAL_CST:
2828 return real_hash (TREE_REAL_CST_PTR (exp));
2830 case FIXED_CST:
2831 return fixed_hash (TREE_FIXED_CST_PTR (exp));
2833 case STRING_CST:
2834 p = TREE_STRING_POINTER (exp);
2835 len = TREE_STRING_LENGTH (exp);
2836 break;
2838 case COMPLEX_CST:
2839 return (const_hash_1 (TREE_REALPART (exp)) * 5
2840 + const_hash_1 (TREE_IMAGPART (exp)));
2842 case CONSTRUCTOR:
2844 unsigned HOST_WIDE_INT idx;
2845 tree value;
2847 hi = 5 + int_size_in_bytes (TREE_TYPE (exp));
2849 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (exp), idx, value)
2850 if (value)
2851 hi = hi * 603 + const_hash_1 (value);
2853 return hi;
2856 case ADDR_EXPR:
2857 case FDESC_EXPR:
2859 struct addr_const value;
2861 decode_addr_const (exp, &value);
2862 switch (GET_CODE (value.base))
2864 case SYMBOL_REF:
2865 /* Don't hash the address of the SYMBOL_REF;
2866 only use the offset and the symbol name. */
2867 hi = value.offset;
2868 p = XSTR (value.base, 0);
2869 for (i = 0; p[i] != 0; i++)
2870 hi = ((hi * 613) + (unsigned) (p[i]));
2871 break;
2873 case LABEL_REF:
2874 hi = value.offset + CODE_LABEL_NUMBER (XEXP (value.base, 0)) * 13;
2875 break;
2877 default:
2878 gcc_unreachable ();
2881 return hi;
2883 case PLUS_EXPR:
2884 case POINTER_PLUS_EXPR:
2885 case MINUS_EXPR:
2886 return (const_hash_1 (TREE_OPERAND (exp, 0)) * 9
2887 + const_hash_1 (TREE_OPERAND (exp, 1)));
2889 CASE_CONVERT:
2890 return const_hash_1 (TREE_OPERAND (exp, 0)) * 7 + 2;
2892 default:
2893 /* A language specific constant. Just hash the code. */
2894 return code;
2897 /* Compute hashing function. */
2898 hi = len;
2899 for (i = 0; i < len; i++)
2900 hi = ((hi * 613) + (unsigned) (p[i]));
2902 return hi;
2905 /* Wrapper of compare_constant, for the htab interface. */
2906 static int
2907 const_desc_eq (const void *p1, const void *p2)
2909 const struct constant_descriptor_tree *const c1
2910 = (const struct constant_descriptor_tree *) p1;
2911 const struct constant_descriptor_tree *const c2
2912 = (const struct constant_descriptor_tree *) p2;
2913 if (c1->hash != c2->hash)
2914 return 0;
2915 return compare_constant (c1->value, c2->value);
2918 /* Compare t1 and t2, and return 1 only if they are known to result in
2919 the same bit pattern on output. */
2921 static int
2922 compare_constant (const tree t1, const tree t2)
2924 enum tree_code typecode;
2926 if (t1 == NULL_TREE)
2927 return t2 == NULL_TREE;
2928 if (t2 == NULL_TREE)
2929 return 0;
2931 if (TREE_CODE (t1) != TREE_CODE (t2))
2932 return 0;
2934 switch (TREE_CODE (t1))
2936 case INTEGER_CST:
2937 /* Integer constants are the same only if the same width of type. */
2938 if (TYPE_PRECISION (TREE_TYPE (t1)) != TYPE_PRECISION (TREE_TYPE (t2)))
2939 return 0;
2940 if (TYPE_MODE (TREE_TYPE (t1)) != TYPE_MODE (TREE_TYPE (t2)))
2941 return 0;
2942 return tree_int_cst_equal (t1, t2);
2944 case REAL_CST:
2945 /* Real constants are the same only if the same width of type. */
2946 if (TYPE_PRECISION (TREE_TYPE (t1)) != TYPE_PRECISION (TREE_TYPE (t2)))
2947 return 0;
2949 return REAL_VALUES_IDENTICAL (TREE_REAL_CST (t1), TREE_REAL_CST (t2));
2951 case FIXED_CST:
2952 /* Fixed constants are the same only if the same width of type. */
2953 if (TYPE_PRECISION (TREE_TYPE (t1)) != TYPE_PRECISION (TREE_TYPE (t2)))
2954 return 0;
2956 return FIXED_VALUES_IDENTICAL (TREE_FIXED_CST (t1), TREE_FIXED_CST (t2));
2958 case STRING_CST:
2959 if (TYPE_MODE (TREE_TYPE (t1)) != TYPE_MODE (TREE_TYPE (t2)))
2960 return 0;
2962 return (TREE_STRING_LENGTH (t1) == TREE_STRING_LENGTH (t2)
2963 && ! memcmp (TREE_STRING_POINTER (t1), TREE_STRING_POINTER (t2),
2964 TREE_STRING_LENGTH (t1)));
2966 case COMPLEX_CST:
2967 return (compare_constant (TREE_REALPART (t1), TREE_REALPART (t2))
2968 && compare_constant (TREE_IMAGPART (t1), TREE_IMAGPART (t2)));
2970 case CONSTRUCTOR:
2972 VEC(constructor_elt, gc) *v1, *v2;
2973 unsigned HOST_WIDE_INT idx;
2975 typecode = TREE_CODE (TREE_TYPE (t1));
2976 if (typecode != TREE_CODE (TREE_TYPE (t2)))
2977 return 0;
2979 if (typecode == ARRAY_TYPE)
2981 HOST_WIDE_INT size_1 = int_size_in_bytes (TREE_TYPE (t1));
2982 /* For arrays, check that the sizes all match. */
2983 if (TYPE_MODE (TREE_TYPE (t1)) != TYPE_MODE (TREE_TYPE (t2))
2984 || size_1 == -1
2985 || size_1 != int_size_in_bytes (TREE_TYPE (t2)))
2986 return 0;
2988 else
2990 /* For record and union constructors, require exact type
2991 equality. */
2992 if (TREE_TYPE (t1) != TREE_TYPE (t2))
2993 return 0;
2996 v1 = CONSTRUCTOR_ELTS (t1);
2997 v2 = CONSTRUCTOR_ELTS (t2);
2998 if (VEC_length (constructor_elt, v1)
2999 != VEC_length (constructor_elt, v2))
3000 return 0;
3002 for (idx = 0; idx < VEC_length (constructor_elt, v1); ++idx)
3004 constructor_elt *c1 = VEC_index (constructor_elt, v1, idx);
3005 constructor_elt *c2 = VEC_index (constructor_elt, v2, idx);
3007 /* Check that each value is the same... */
3008 if (!compare_constant (c1->value, c2->value))
3009 return 0;
3010 /* ... and that they apply to the same fields! */
3011 if (typecode == ARRAY_TYPE)
3013 if (!compare_constant (c1->index, c2->index))
3014 return 0;
3016 else
3018 if (c1->index != c2->index)
3019 return 0;
3023 return 1;
3026 case ADDR_EXPR:
3027 case FDESC_EXPR:
3029 struct addr_const value1, value2;
3031 decode_addr_const (t1, &value1);
3032 decode_addr_const (t2, &value2);
3033 return (value1.offset == value2.offset
3034 && strcmp (XSTR (value1.base, 0), XSTR (value2.base, 0)) == 0);
3037 case PLUS_EXPR:
3038 case POINTER_PLUS_EXPR:
3039 case MINUS_EXPR:
3040 case RANGE_EXPR:
3041 return (compare_constant (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0))
3042 && compare_constant(TREE_OPERAND (t1, 1), TREE_OPERAND (t2, 1)));
3044 CASE_CONVERT:
3045 case VIEW_CONVERT_EXPR:
3046 return compare_constant (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
3048 default:
3049 return 0;
3052 gcc_unreachable ();
3055 /* Make a copy of the whole tree structure for a constant. This
3056 handles the same types of nodes that compare_constant handles. */
3058 static tree
3059 copy_constant (tree exp)
3061 switch (TREE_CODE (exp))
3063 case ADDR_EXPR:
3064 /* For ADDR_EXPR, we do not want to copy the decl whose address
3065 is requested. We do want to copy constants though. */
3066 if (CONSTANT_CLASS_P (TREE_OPERAND (exp, 0)))
3067 return build1 (TREE_CODE (exp), TREE_TYPE (exp),
3068 copy_constant (TREE_OPERAND (exp, 0)));
3069 else
3070 return copy_node (exp);
3072 case INTEGER_CST:
3073 case REAL_CST:
3074 case FIXED_CST:
3075 case STRING_CST:
3076 return copy_node (exp);
3078 case COMPLEX_CST:
3079 return build_complex (TREE_TYPE (exp),
3080 copy_constant (TREE_REALPART (exp)),
3081 copy_constant (TREE_IMAGPART (exp)));
3083 case PLUS_EXPR:
3084 case POINTER_PLUS_EXPR:
3085 case MINUS_EXPR:
3086 return build2 (TREE_CODE (exp), TREE_TYPE (exp),
3087 copy_constant (TREE_OPERAND (exp, 0)),
3088 copy_constant (TREE_OPERAND (exp, 1)));
3090 CASE_CONVERT:
3091 case VIEW_CONVERT_EXPR:
3092 return build1 (TREE_CODE (exp), TREE_TYPE (exp),
3093 copy_constant (TREE_OPERAND (exp, 0)));
3095 case CONSTRUCTOR:
3097 tree copy = copy_node (exp);
3098 VEC(constructor_elt, gc) *v;
3099 unsigned HOST_WIDE_INT idx;
3100 tree purpose, value;
3102 v = VEC_alloc(constructor_elt, gc, VEC_length(constructor_elt,
3103 CONSTRUCTOR_ELTS (exp)));
3104 FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (exp), idx, purpose, value)
3106 constructor_elt *ce = VEC_quick_push (constructor_elt, v, NULL);
3107 ce->index = purpose;
3108 ce->value = copy_constant (value);
3110 CONSTRUCTOR_ELTS (copy) = v;
3111 return copy;
3114 default:
3115 gcc_unreachable ();
3119 /* Return the alignment of constant EXP in bits. */
3121 static unsigned int
3122 get_constant_alignment (tree exp)
3124 unsigned int align;
3126 align = TYPE_ALIGN (TREE_TYPE (exp));
3127 #ifdef CONSTANT_ALIGNMENT
3128 align = CONSTANT_ALIGNMENT (exp, align);
3129 #endif
3130 return align;
3133 /* Return the section into which constant EXP should be placed. */
3135 static section *
3136 get_constant_section (tree exp)
3138 if (IN_NAMED_SECTION (exp))
3139 return get_named_section (exp, NULL, compute_reloc_for_constant (exp));
3140 else
3141 return targetm.asm_out.select_section (exp,
3142 compute_reloc_for_constant (exp),
3143 get_constant_alignment (exp));
3146 /* Return the size of constant EXP in bytes. */
3148 static HOST_WIDE_INT
3149 get_constant_size (tree exp)
3151 HOST_WIDE_INT size;
3153 size = int_size_in_bytes (TREE_TYPE (exp));
3154 if (TREE_CODE (exp) == STRING_CST)
3155 size = MAX (TREE_STRING_LENGTH (exp), size);
3156 return size;
3159 /* Subroutine of output_constant_def:
3160 No constant equal to EXP is known to have been output.
3161 Make a constant descriptor to enter EXP in the hash table.
3162 Assign the label number and construct RTL to refer to the
3163 constant's location in memory.
3164 Caller is responsible for updating the hash table. */
3166 static struct constant_descriptor_tree *
3167 build_constant_desc (tree exp)
3169 rtx symbol;
3170 rtx rtl;
3171 char label[256];
3172 int labelno;
3173 struct constant_descriptor_tree *desc;
3175 desc = GGC_NEW (struct constant_descriptor_tree);
3176 desc->value = copy_constant (exp);
3178 /* Propagate marked-ness to copied constant. */
3179 if (flag_mudflap && mf_marked_p (exp))
3180 mf_mark (desc->value);
3182 /* Create a string containing the label name, in LABEL. */
3183 labelno = const_labelno++;
3184 ASM_GENERATE_INTERNAL_LABEL (label, "LC", labelno);
3186 /* We have a symbol name; construct the SYMBOL_REF and the MEM. */
3187 if (use_object_blocks_p ())
3189 section *sect = get_constant_section (exp);
3190 symbol = create_block_symbol (ggc_strdup (label),
3191 get_block_for_section (sect), -1);
3193 else
3194 symbol = gen_rtx_SYMBOL_REF (Pmode, ggc_strdup (label));
3195 SYMBOL_REF_FLAGS (symbol) |= SYMBOL_FLAG_LOCAL;
3196 SET_SYMBOL_REF_DECL (symbol, desc->value);
3197 TREE_CONSTANT_POOL_ADDRESS_P (symbol) = 1;
3199 rtl = gen_rtx_MEM (TYPE_MODE (TREE_TYPE (exp)), symbol);
3200 set_mem_attributes (rtl, exp, 1);
3201 set_mem_alias_set (rtl, 0);
3202 set_mem_alias_set (rtl, const_alias_set);
3204 /* We cannot share RTX'es in pool entries.
3205 Mark this piece of RTL as required for unsharing. */
3206 RTX_FLAG (rtl, used) = 1;
3208 /* Set flags or add text to the name to record information, such as
3209 that it is a local symbol. If the name is changed, the macro
3210 ASM_OUTPUT_LABELREF will have to know how to strip this
3211 information. This call might invalidate our local variable
3212 SYMBOL; we can't use it afterward. */
3214 targetm.encode_section_info (exp, rtl, true);
3216 desc->rtl = rtl;
3218 return desc;
3221 /* Return an rtx representing a reference to constant data in memory
3222 for the constant expression EXP.
3224 If assembler code for such a constant has already been output,
3225 return an rtx to refer to it.
3226 Otherwise, output such a constant in memory
3227 and generate an rtx for it.
3229 If DEFER is nonzero, this constant can be deferred and output only
3230 if referenced in the function after all optimizations.
3232 `const_desc_table' records which constants already have label strings. */
3235 output_constant_def (tree exp, int defer)
3237 struct constant_descriptor_tree *desc;
3238 struct constant_descriptor_tree key;
3239 void **loc;
3241 /* Look up EXP in the table of constant descriptors. If we didn't find
3242 it, create a new one. */
3243 key.value = exp;
3244 key.hash = const_hash_1 (exp);
3245 loc = htab_find_slot_with_hash (const_desc_htab, &key, key.hash, INSERT);
3247 desc = (struct constant_descriptor_tree *) *loc;
3248 if (desc == 0)
3250 desc = build_constant_desc (exp);
3251 desc->hash = key.hash;
3252 *loc = desc;
3255 maybe_output_constant_def_contents (desc, defer);
3256 return desc->rtl;
3259 /* Subroutine of output_constant_def: Decide whether or not we need to
3260 output the constant DESC now, and if so, do it. */
3261 static void
3262 maybe_output_constant_def_contents (struct constant_descriptor_tree *desc,
3263 int defer)
3265 rtx symbol = XEXP (desc->rtl, 0);
3266 tree exp = desc->value;
3268 if (flag_syntax_only)
3269 return;
3271 if (TREE_ASM_WRITTEN (exp))
3272 /* Already output; don't do it again. */
3273 return;
3275 /* We can always defer constants as long as the context allows
3276 doing so. */
3277 if (defer)
3279 /* Increment n_deferred_constants if it exists. It needs to be at
3280 least as large as the number of constants actually referred to
3281 by the function. If it's too small we'll stop looking too early
3282 and fail to emit constants; if it's too large we'll only look
3283 through the entire function when we could have stopped earlier. */
3284 if (cfun)
3285 n_deferred_constants++;
3286 return;
3289 output_constant_def_contents (symbol);
3292 /* Subroutine of output_constant_def_contents. Output the definition
3293 of constant EXP, which is pointed to by label LABEL. ALIGN is the
3294 constant's alignment in bits. */
3296 static void
3297 assemble_constant_contents (tree exp, const char *label, unsigned int align)
3299 HOST_WIDE_INT size;
3301 size = get_constant_size (exp);
3303 /* Do any machine/system dependent processing of the constant. */
3304 #ifdef ASM_DECLARE_CONSTANT_NAME
3305 ASM_DECLARE_CONSTANT_NAME (asm_out_file, label, exp, size);
3306 #else
3307 /* Standard thing is just output label for the constant. */
3308 ASM_OUTPUT_LABEL (asm_out_file, label);
3309 #endif /* ASM_DECLARE_CONSTANT_NAME */
3311 /* Output the value of EXP. */
3312 output_constant (exp, size, align);
3315 /* We must output the constant data referred to by SYMBOL; do so. */
3317 static void
3318 output_constant_def_contents (rtx symbol)
3320 tree exp = SYMBOL_REF_DECL (symbol);
3321 unsigned int align;
3323 /* Make sure any other constants whose addresses appear in EXP
3324 are assigned label numbers. */
3325 output_addressed_constants (exp);
3327 /* We are no longer deferring this constant. */
3328 TREE_ASM_WRITTEN (exp) = 1;
3330 /* If the constant is part of an object block, make sure that the
3331 decl has been positioned within its block, but do not write out
3332 its definition yet. output_object_blocks will do that later. */
3333 if (SYMBOL_REF_HAS_BLOCK_INFO_P (symbol) && SYMBOL_REF_BLOCK (symbol))
3334 place_block_symbol (symbol);
3335 else
3337 switch_to_section (get_constant_section (exp));
3338 align = get_constant_alignment (exp);
3339 if (align > BITS_PER_UNIT)
3340 ASM_OUTPUT_ALIGN (asm_out_file, floor_log2 (align / BITS_PER_UNIT));
3341 assemble_constant_contents (exp, XSTR (symbol, 0), align);
3343 if (flag_mudflap)
3344 mudflap_enqueue_constant (exp);
3347 /* Look up EXP in the table of constant descriptors. Return the rtl
3348 if it has been emitted, else null. */
3351 lookup_constant_def (tree exp)
3353 struct constant_descriptor_tree *desc;
3354 struct constant_descriptor_tree key;
3356 key.value = exp;
3357 key.hash = const_hash_1 (exp);
3358 desc = (struct constant_descriptor_tree *)
3359 htab_find_with_hash (const_desc_htab, &key, key.hash);
3361 return (desc ? desc->rtl : NULL_RTX);
3364 /* Used in the hash tables to avoid outputting the same constant
3365 twice. Unlike 'struct constant_descriptor_tree', RTX constants
3366 are output once per function, not once per file. */
3367 /* ??? Only a few targets need per-function constant pools. Most
3368 can use one per-file pool. Should add a targetm bit to tell the
3369 difference. */
3371 struct GTY(()) rtx_constant_pool {
3372 /* Pointers to first and last constant in pool, as ordered by offset. */
3373 struct constant_descriptor_rtx *first;
3374 struct constant_descriptor_rtx *last;
3376 /* Hash facility for making memory-constants from constant rtl-expressions.
3377 It is used on RISC machines where immediate integer arguments and
3378 constant addresses are restricted so that such constants must be stored
3379 in memory. */
3380 htab_t GTY((param_is (struct constant_descriptor_rtx))) const_rtx_htab;
3382 /* Current offset in constant pool (does not include any
3383 machine-specific header). */
3384 HOST_WIDE_INT offset;
3387 struct GTY((chain_next ("%h.next"))) constant_descriptor_rtx {
3388 struct constant_descriptor_rtx *next;
3389 rtx mem;
3390 rtx sym;
3391 rtx constant;
3392 HOST_WIDE_INT offset;
3393 hashval_t hash;
3394 enum machine_mode mode;
3395 unsigned int align;
3396 int labelno;
3397 int mark;
3400 /* Hash and compare functions for const_rtx_htab. */
3402 static hashval_t
3403 const_desc_rtx_hash (const void *ptr)
3405 const struct constant_descriptor_rtx *const desc
3406 = (const struct constant_descriptor_rtx *) ptr;
3407 return desc->hash;
3410 static int
3411 const_desc_rtx_eq (const void *a, const void *b)
3413 const struct constant_descriptor_rtx *const x
3414 = (const struct constant_descriptor_rtx *) a;
3415 const struct constant_descriptor_rtx *const y
3416 = (const struct constant_descriptor_rtx *) b;
3418 if (x->mode != y->mode)
3419 return 0;
3420 return rtx_equal_p (x->constant, y->constant);
3423 /* This is the worker function for const_rtx_hash, called via for_each_rtx. */
3425 static int
3426 const_rtx_hash_1 (rtx *xp, void *data)
3428 unsigned HOST_WIDE_INT hwi;
3429 enum machine_mode mode;
3430 enum rtx_code code;
3431 hashval_t h, *hp;
3432 rtx x;
3434 x = *xp;
3435 code = GET_CODE (x);
3436 mode = GET_MODE (x);
3437 h = (hashval_t) code * 1048573 + mode;
3439 switch (code)
3441 case CONST_INT:
3442 hwi = INTVAL (x);
3443 fold_hwi:
3445 int shift = sizeof (hashval_t) * CHAR_BIT;
3446 const int n = sizeof (HOST_WIDE_INT) / sizeof (hashval_t);
3447 int i;
3449 h ^= (hashval_t) hwi;
3450 for (i = 1; i < n; ++i)
3452 hwi >>= shift;
3453 h ^= (hashval_t) hwi;
3456 break;
3458 case CONST_DOUBLE:
3459 if (mode == VOIDmode)
3461 hwi = CONST_DOUBLE_LOW (x) ^ CONST_DOUBLE_HIGH (x);
3462 goto fold_hwi;
3464 else
3465 h ^= real_hash (CONST_DOUBLE_REAL_VALUE (x));
3466 break;
3468 case CONST_FIXED:
3469 h ^= fixed_hash (CONST_FIXED_VALUE (x));
3470 break;
3472 case CONST_VECTOR:
3474 int i;
3475 for (i = XVECLEN (x, 0); i-- > 0; )
3476 h = h * 251 + const_rtx_hash_1 (&XVECEXP (x, 0, i), data);
3478 break;
3480 case SYMBOL_REF:
3481 h ^= htab_hash_string (XSTR (x, 0));
3482 break;
3484 case LABEL_REF:
3485 h = h * 251 + CODE_LABEL_NUMBER (XEXP (x, 0));
3486 break;
3488 case UNSPEC:
3489 case UNSPEC_VOLATILE:
3490 h = h * 251 + XINT (x, 1);
3491 break;
3493 default:
3494 break;
3497 hp = (hashval_t *) data;
3498 *hp = *hp * 509 + h;
3499 return 0;
3502 /* Compute a hash value for X, which should be a constant. */
3504 static hashval_t
3505 const_rtx_hash (rtx x)
3507 hashval_t h = 0;
3508 for_each_rtx (&x, const_rtx_hash_1, &h);
3509 return h;
3513 /* Create and return a new rtx constant pool. */
3515 static struct rtx_constant_pool *
3516 create_constant_pool (void)
3518 struct rtx_constant_pool *pool;
3520 pool = GGC_NEW (struct rtx_constant_pool);
3521 pool->const_rtx_htab = htab_create_ggc (31, const_desc_rtx_hash,
3522 const_desc_rtx_eq, NULL);
3523 pool->first = NULL;
3524 pool->last = NULL;
3525 pool->offset = 0;
3526 return pool;
3529 /* Initialize constant pool hashing for a new function. */
3531 void
3532 init_varasm_status (void)
3534 crtl->varasm.pool = create_constant_pool ();
3535 crtl->varasm.deferred_constants = 0;
3538 /* Given a MINUS expression, simplify it if both sides
3539 include the same symbol. */
3542 simplify_subtraction (rtx x)
3544 rtx r = simplify_rtx (x);
3545 return r ? r : x;
3548 /* Given a constant rtx X, make (or find) a memory constant for its value
3549 and return a MEM rtx to refer to it in memory. */
3552 force_const_mem (enum machine_mode mode, rtx x)
3554 struct constant_descriptor_rtx *desc, tmp;
3555 struct rtx_constant_pool *pool;
3556 char label[256];
3557 rtx def, symbol;
3558 hashval_t hash;
3559 unsigned int align;
3560 void **slot;
3562 /* If we're not allowed to drop X into the constant pool, don't. */
3563 if (targetm.cannot_force_const_mem (x))
3564 return NULL_RTX;
3566 /* Record that this function has used a constant pool entry. */
3567 crtl->uses_const_pool = 1;
3569 /* Decide which pool to use. */
3570 pool = (targetm.use_blocks_for_constant_p (mode, x)
3571 ? shared_constant_pool
3572 : crtl->varasm.pool);
3574 /* Lookup the value in the hashtable. */
3575 tmp.constant = x;
3576 tmp.mode = mode;
3577 hash = const_rtx_hash (x);
3578 slot = htab_find_slot_with_hash (pool->const_rtx_htab, &tmp, hash, INSERT);
3579 desc = (struct constant_descriptor_rtx *) *slot;
3581 /* If the constant was already present, return its memory. */
3582 if (desc)
3583 return copy_rtx (desc->mem);
3585 /* Otherwise, create a new descriptor. */
3586 desc = GGC_NEW (struct constant_descriptor_rtx);
3587 *slot = desc;
3589 /* Align the location counter as required by EXP's data type. */
3590 align = GET_MODE_ALIGNMENT (mode == VOIDmode ? word_mode : mode);
3591 #ifdef CONSTANT_ALIGNMENT
3593 tree type = lang_hooks.types.type_for_mode (mode, 0);
3594 if (type != NULL_TREE)
3595 align = CONSTANT_ALIGNMENT (make_tree (type, x), align);
3597 #endif
3599 pool->offset += (align / BITS_PER_UNIT) - 1;
3600 pool->offset &= ~ ((align / BITS_PER_UNIT) - 1);
3602 desc->next = NULL;
3603 desc->constant = tmp.constant;
3604 desc->offset = pool->offset;
3605 desc->hash = hash;
3606 desc->mode = mode;
3607 desc->align = align;
3608 desc->labelno = const_labelno;
3609 desc->mark = 0;
3611 pool->offset += GET_MODE_SIZE (mode);
3612 if (pool->last)
3613 pool->last->next = desc;
3614 else
3615 pool->first = pool->last = desc;
3616 pool->last = desc;
3618 /* Create a string containing the label name, in LABEL. */
3619 ASM_GENERATE_INTERNAL_LABEL (label, "LC", const_labelno);
3620 ++const_labelno;
3622 /* Construct the SYMBOL_REF. Make sure to mark it as belonging to
3623 the constants pool. */
3624 if (use_object_blocks_p () && targetm.use_blocks_for_constant_p (mode, x))
3626 section *sect = targetm.asm_out.select_rtx_section (mode, x, align);
3627 symbol = create_block_symbol (ggc_strdup (label),
3628 get_block_for_section (sect), -1);
3630 else
3631 symbol = gen_rtx_SYMBOL_REF (Pmode, ggc_strdup (label));
3632 desc->sym = symbol;
3633 SYMBOL_REF_FLAGS (symbol) |= SYMBOL_FLAG_LOCAL;
3634 CONSTANT_POOL_ADDRESS_P (symbol) = 1;
3635 SET_SYMBOL_REF_CONSTANT (symbol, desc);
3637 /* Construct the MEM. */
3638 desc->mem = def = gen_const_mem (mode, symbol);
3639 set_mem_attributes (def, lang_hooks.types.type_for_mode (mode, 0), 1);
3640 set_mem_align (def, align);
3642 /* If we're dropping a label to the constant pool, make sure we
3643 don't delete it. */
3644 if (GET_CODE (x) == LABEL_REF)
3645 LABEL_PRESERVE_P (XEXP (x, 0)) = 1;
3647 return copy_rtx (def);
3650 /* Given a constant pool SYMBOL_REF, return the corresponding constant. */
3653 get_pool_constant (rtx addr)
3655 return SYMBOL_REF_CONSTANT (addr)->constant;
3658 /* Given a constant pool SYMBOL_REF, return the corresponding constant
3659 and whether it has been output or not. */
3662 get_pool_constant_mark (rtx addr, bool *pmarked)
3664 struct constant_descriptor_rtx *desc;
3666 desc = SYMBOL_REF_CONSTANT (addr);
3667 *pmarked = (desc->mark != 0);
3668 return desc->constant;
3671 /* Similar, return the mode. */
3673 enum machine_mode
3674 get_pool_mode (const_rtx addr)
3676 return SYMBOL_REF_CONSTANT (addr)->mode;
3679 /* Return the size of the constant pool. */
3682 get_pool_size (void)
3684 return crtl->varasm.pool->offset;
3687 /* Worker function for output_constant_pool_1. Emit assembly for X
3688 in MODE with known alignment ALIGN. */
3690 static void
3691 output_constant_pool_2 (enum machine_mode mode, rtx x, unsigned int align)
3693 switch (GET_MODE_CLASS (mode))
3695 case MODE_FLOAT:
3696 case MODE_DECIMAL_FLOAT:
3698 REAL_VALUE_TYPE r;
3700 gcc_assert (GET_CODE (x) == CONST_DOUBLE);
3701 REAL_VALUE_FROM_CONST_DOUBLE (r, x);
3702 assemble_real (r, mode, align);
3703 break;
3706 case MODE_INT:
3707 case MODE_PARTIAL_INT:
3708 case MODE_FRACT:
3709 case MODE_UFRACT:
3710 case MODE_ACCUM:
3711 case MODE_UACCUM:
3712 assemble_integer (x, GET_MODE_SIZE (mode), align, 1);
3713 break;
3715 case MODE_VECTOR_FLOAT:
3716 case MODE_VECTOR_INT:
3717 case MODE_VECTOR_FRACT:
3718 case MODE_VECTOR_UFRACT:
3719 case MODE_VECTOR_ACCUM:
3720 case MODE_VECTOR_UACCUM:
3722 int i, units;
3723 enum machine_mode submode = GET_MODE_INNER (mode);
3724 unsigned int subalign = MIN (align, GET_MODE_BITSIZE (submode));
3726 gcc_assert (GET_CODE (x) == CONST_VECTOR);
3727 units = CONST_VECTOR_NUNITS (x);
3729 for (i = 0; i < units; i++)
3731 rtx elt = CONST_VECTOR_ELT (x, i);
3732 output_constant_pool_2 (submode, elt, i ? subalign : align);
3735 break;
3737 default:
3738 gcc_unreachable ();
3742 /* Worker function for output_constant_pool. Emit constant DESC,
3743 giving it ALIGN bits of alignment. */
3745 static void
3746 output_constant_pool_1 (struct constant_descriptor_rtx *desc,
3747 unsigned int align)
3749 rtx x, tmp;
3751 x = desc->constant;
3753 /* See if X is a LABEL_REF (or a CONST referring to a LABEL_REF)
3754 whose CODE_LABEL has been deleted. This can occur if a jump table
3755 is eliminated by optimization. If so, write a constant of zero
3756 instead. Note that this can also happen by turning the
3757 CODE_LABEL into a NOTE. */
3758 /* ??? This seems completely and utterly wrong. Certainly it's
3759 not true for NOTE_INSN_DELETED_LABEL, but I disbelieve proper
3760 functioning even with INSN_DELETED_P and friends. */
3762 tmp = x;
3763 switch (GET_CODE (tmp))
3765 case CONST:
3766 if (GET_CODE (XEXP (tmp, 0)) != PLUS
3767 || GET_CODE (XEXP (XEXP (tmp, 0), 0)) != LABEL_REF)
3768 break;
3769 tmp = XEXP (XEXP (tmp, 0), 0);
3770 /* FALLTHRU */
3772 case LABEL_REF:
3773 tmp = XEXP (tmp, 0);
3774 gcc_assert (!INSN_DELETED_P (tmp));
3775 gcc_assert (!NOTE_P (tmp)
3776 || NOTE_KIND (tmp) != NOTE_INSN_DELETED);
3777 break;
3779 default:
3780 break;
3783 #ifdef ASM_OUTPUT_SPECIAL_POOL_ENTRY
3784 ASM_OUTPUT_SPECIAL_POOL_ENTRY (asm_out_file, x, desc->mode,
3785 align, desc->labelno, done);
3786 #endif
3788 assemble_align (align);
3790 /* Output the label. */
3791 targetm.asm_out.internal_label (asm_out_file, "LC", desc->labelno);
3793 /* Output the data. */
3794 output_constant_pool_2 (desc->mode, x, align);
3796 /* Make sure all constants in SECTION_MERGE and not SECTION_STRINGS
3797 sections have proper size. */
3798 if (align > GET_MODE_BITSIZE (desc->mode)
3799 && in_section
3800 && (in_section->common.flags & SECTION_MERGE))
3801 assemble_align (align);
3803 #ifdef ASM_OUTPUT_SPECIAL_POOL_ENTRY
3804 done:
3805 #endif
3806 return;
3809 /* Given a SYMBOL_REF CURRENT_RTX, mark it and all constants it refers
3810 to as used. Emit referenced deferred strings. This function can
3811 be used with for_each_rtx to mark all SYMBOL_REFs in an rtx. */
3813 static int
3814 mark_constant (rtx *current_rtx, void *data ATTRIBUTE_UNUSED)
3816 rtx x = *current_rtx;
3818 if (x == NULL_RTX || GET_CODE (x) != SYMBOL_REF)
3819 return 0;
3821 if (CONSTANT_POOL_ADDRESS_P (x))
3823 struct constant_descriptor_rtx *desc = SYMBOL_REF_CONSTANT (x);
3824 if (desc->mark == 0)
3826 desc->mark = 1;
3827 for_each_rtx (&desc->constant, mark_constant, NULL);
3830 else if (TREE_CONSTANT_POOL_ADDRESS_P (x))
3832 tree exp = SYMBOL_REF_DECL (x);
3833 if (!TREE_ASM_WRITTEN (exp))
3835 n_deferred_constants--;
3836 output_constant_def_contents (x);
3840 return -1;
3843 /* Look through appropriate parts of INSN, marking all entries in the
3844 constant pool which are actually being used. Entries that are only
3845 referenced by other constants are also marked as used. Emit
3846 deferred strings that are used. */
3848 static void
3849 mark_constants (rtx insn)
3851 if (!INSN_P (insn))
3852 return;
3854 /* Insns may appear inside a SEQUENCE. Only check the patterns of
3855 insns, not any notes that may be attached. We don't want to mark
3856 a constant just because it happens to appear in a REG_EQUIV note. */
3857 if (GET_CODE (PATTERN (insn)) == SEQUENCE)
3859 rtx seq = PATTERN (insn);
3860 int i, n = XVECLEN (seq, 0);
3861 for (i = 0; i < n; ++i)
3863 rtx subinsn = XVECEXP (seq, 0, i);
3864 if (INSN_P (subinsn))
3865 for_each_rtx (&PATTERN (subinsn), mark_constant, NULL);
3868 else
3869 for_each_rtx (&PATTERN (insn), mark_constant, NULL);
3872 /* Look through the instructions for this function, and mark all the
3873 entries in POOL which are actually being used. Emit deferred constants
3874 which have indeed been used. */
3876 static void
3877 mark_constant_pool (void)
3879 rtx insn, link;
3881 if (!crtl->uses_const_pool && n_deferred_constants == 0)
3882 return;
3884 for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
3885 mark_constants (insn);
3887 for (link = crtl->epilogue_delay_list;
3888 link;
3889 link = XEXP (link, 1))
3890 mark_constants (XEXP (link, 0));
3893 /* Write all the constants in POOL. */
3895 static void
3896 output_constant_pool_contents (struct rtx_constant_pool *pool)
3898 struct constant_descriptor_rtx *desc;
3900 for (desc = pool->first; desc ; desc = desc->next)
3901 if (desc->mark)
3903 /* If the constant is part of an object_block, make sure that
3904 the constant has been positioned within its block, but do not
3905 write out its definition yet. output_object_blocks will do
3906 that later. */
3907 if (SYMBOL_REF_HAS_BLOCK_INFO_P (desc->sym)
3908 && SYMBOL_REF_BLOCK (desc->sym))
3909 place_block_symbol (desc->sym);
3910 else
3912 switch_to_section (targetm.asm_out.select_rtx_section
3913 (desc->mode, desc->constant, desc->align));
3914 output_constant_pool_1 (desc, desc->align);
3919 /* Mark all constants that are used in the current function, then write
3920 out the function's private constant pool. */
3922 static void
3923 output_constant_pool (const char *fnname ATTRIBUTE_UNUSED,
3924 tree fndecl ATTRIBUTE_UNUSED)
3926 struct rtx_constant_pool *pool = crtl->varasm.pool;
3928 /* It is possible for gcc to call force_const_mem and then to later
3929 discard the instructions which refer to the constant. In such a
3930 case we do not need to output the constant. */
3931 mark_constant_pool ();
3933 #ifdef ASM_OUTPUT_POOL_PROLOGUE
3934 ASM_OUTPUT_POOL_PROLOGUE (asm_out_file, fnname, fndecl, pool->offset);
3935 #endif
3937 output_constant_pool_contents (pool);
3939 #ifdef ASM_OUTPUT_POOL_EPILOGUE
3940 ASM_OUTPUT_POOL_EPILOGUE (asm_out_file, fnname, fndecl, pool->offset);
3941 #endif
3944 /* Write the contents of the shared constant pool. */
3946 void
3947 output_shared_constant_pool (void)
3949 output_constant_pool_contents (shared_constant_pool);
3952 /* Determine what kind of relocations EXP may need. */
3955 compute_reloc_for_constant (tree exp)
3957 int reloc = 0, reloc2;
3958 tree tem;
3960 switch (TREE_CODE (exp))
3962 case ADDR_EXPR:
3963 case FDESC_EXPR:
3964 /* Go inside any operations that get_inner_reference can handle and see
3965 if what's inside is a constant: no need to do anything here for
3966 addresses of variables or functions. */
3967 for (tem = TREE_OPERAND (exp, 0); handled_component_p (tem);
3968 tem = TREE_OPERAND (tem, 0))
3971 if (TREE_PUBLIC (tem))
3972 reloc |= 2;
3973 else
3974 reloc |= 1;
3975 break;
3977 case PLUS_EXPR:
3978 case POINTER_PLUS_EXPR:
3979 reloc = compute_reloc_for_constant (TREE_OPERAND (exp, 0));
3980 reloc |= compute_reloc_for_constant (TREE_OPERAND (exp, 1));
3981 break;
3983 case MINUS_EXPR:
3984 reloc = compute_reloc_for_constant (TREE_OPERAND (exp, 0));
3985 reloc2 = compute_reloc_for_constant (TREE_OPERAND (exp, 1));
3986 /* The difference of two local labels is computable at link time. */
3987 if (reloc == 1 && reloc2 == 1)
3988 reloc = 0;
3989 else
3990 reloc |= reloc2;
3991 break;
3993 CASE_CONVERT:
3994 case VIEW_CONVERT_EXPR:
3995 reloc = compute_reloc_for_constant (TREE_OPERAND (exp, 0));
3996 break;
3998 case CONSTRUCTOR:
4000 unsigned HOST_WIDE_INT idx;
4001 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (exp), idx, tem)
4002 if (tem != 0)
4003 reloc |= compute_reloc_for_constant (tem);
4005 break;
4007 default:
4008 break;
4010 return reloc;
4013 /* Find all the constants whose addresses are referenced inside of EXP,
4014 and make sure assembler code with a label has been output for each one.
4015 Indicate whether an ADDR_EXPR has been encountered. */
4017 static void
4018 output_addressed_constants (tree exp)
4020 tree tem;
4022 switch (TREE_CODE (exp))
4024 case ADDR_EXPR:
4025 case FDESC_EXPR:
4026 /* Go inside any operations that get_inner_reference can handle and see
4027 if what's inside is a constant: no need to do anything here for
4028 addresses of variables or functions. */
4029 for (tem = TREE_OPERAND (exp, 0); handled_component_p (tem);
4030 tem = TREE_OPERAND (tem, 0))
4033 /* If we have an initialized CONST_DECL, retrieve the initializer. */
4034 if (TREE_CODE (tem) == CONST_DECL && DECL_INITIAL (tem))
4035 tem = DECL_INITIAL (tem);
4037 if (CONSTANT_CLASS_P (tem) || TREE_CODE (tem) == CONSTRUCTOR)
4038 output_constant_def (tem, 0);
4039 break;
4041 case PLUS_EXPR:
4042 case POINTER_PLUS_EXPR:
4043 case MINUS_EXPR:
4044 output_addressed_constants (TREE_OPERAND (exp, 1));
4045 /* Fall through. */
4047 CASE_CONVERT:
4048 case VIEW_CONVERT_EXPR:
4049 output_addressed_constants (TREE_OPERAND (exp, 0));
4050 break;
4052 case CONSTRUCTOR:
4054 unsigned HOST_WIDE_INT idx;
4055 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (exp), idx, tem)
4056 if (tem != 0)
4057 output_addressed_constants (tem);
4059 break;
4061 default:
4062 break;
4066 /* Whether a constructor CTOR is a valid static constant initializer if all
4067 its elements are. This used to be internal to initializer_constant_valid_p
4068 and has been exposed to let other functions like categorize_ctor_elements
4069 evaluate the property while walking a constructor for other purposes. */
4071 bool
4072 constructor_static_from_elts_p (const_tree ctor)
4074 return (TREE_CONSTANT (ctor)
4075 && (TREE_CODE (TREE_TYPE (ctor)) == UNION_TYPE
4076 || TREE_CODE (TREE_TYPE (ctor)) == RECORD_TYPE)
4077 && !VEC_empty (constructor_elt, CONSTRUCTOR_ELTS (ctor)));
4080 /* A subroutine of initializer_constant_valid_p. VALUE is a MINUS_EXPR,
4081 PLUS_EXPR or POINTER_PLUS_EXPR. This looks for cases of VALUE
4082 which are valid when ENDTYPE is an integer of any size; in
4083 particular, this does not accept a pointer minus a constant. This
4084 returns null_pointer_node if the VALUE is an absolute constant
4085 which can be used to initialize a static variable. Otherwise it
4086 returns NULL. */
4088 static tree
4089 narrowing_initializer_constant_valid_p (tree value, tree endtype)
4091 tree op0, op1;
4093 if (!INTEGRAL_TYPE_P (endtype))
4094 return NULL_TREE;
4096 op0 = TREE_OPERAND (value, 0);
4097 op1 = TREE_OPERAND (value, 1);
4099 /* Like STRIP_NOPS except allow the operand mode to widen. This
4100 works around a feature of fold that simplifies (int)(p1 - p2) to
4101 ((int)p1 - (int)p2) under the theory that the narrower operation
4102 is cheaper. */
4104 while (CONVERT_EXPR_P (op0)
4105 || TREE_CODE (op0) == NON_LVALUE_EXPR)
4107 tree inner = TREE_OPERAND (op0, 0);
4108 if (inner == error_mark_node
4109 || ! INTEGRAL_MODE_P (TYPE_MODE (TREE_TYPE (inner)))
4110 || (GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op0)))
4111 > GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (inner)))))
4112 break;
4113 op0 = inner;
4116 while (CONVERT_EXPR_P (op1)
4117 || TREE_CODE (op1) == NON_LVALUE_EXPR)
4119 tree inner = TREE_OPERAND (op1, 0);
4120 if (inner == error_mark_node
4121 || ! INTEGRAL_MODE_P (TYPE_MODE (TREE_TYPE (inner)))
4122 || (GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op1)))
4123 > GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (inner)))))
4124 break;
4125 op1 = inner;
4128 op0 = initializer_constant_valid_p (op0, endtype);
4129 op1 = initializer_constant_valid_p (op1, endtype);
4131 /* Both initializers must be known. */
4132 if (op0 && op1)
4134 if (op0 == op1
4135 && (op0 == null_pointer_node
4136 || TREE_CODE (value) == MINUS_EXPR))
4137 return null_pointer_node;
4139 /* Support differences between labels. */
4140 if (TREE_CODE (op0) == LABEL_DECL
4141 && TREE_CODE (op1) == LABEL_DECL)
4142 return null_pointer_node;
4144 if (TREE_CODE (op0) == STRING_CST
4145 && TREE_CODE (op1) == STRING_CST
4146 && operand_equal_p (op0, op1, 1))
4147 return null_pointer_node;
4150 return NULL_TREE;
4153 /* Return nonzero if VALUE is a valid constant-valued expression
4154 for use in initializing a static variable; one that can be an
4155 element of a "constant" initializer.
4157 Return null_pointer_node if the value is absolute;
4158 if it is relocatable, return the variable that determines the relocation.
4159 We assume that VALUE has been folded as much as possible;
4160 therefore, we do not need to check for such things as
4161 arithmetic-combinations of integers. */
4163 tree
4164 initializer_constant_valid_p (tree value, tree endtype)
4166 tree ret;
4168 switch (TREE_CODE (value))
4170 case CONSTRUCTOR:
4171 if (constructor_static_from_elts_p (value))
4173 unsigned HOST_WIDE_INT idx;
4174 tree elt;
4175 bool absolute = true;
4177 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (value), idx, elt)
4179 tree reloc;
4180 reloc = initializer_constant_valid_p (elt, TREE_TYPE (elt));
4181 if (!reloc)
4182 return NULL_TREE;
4183 if (reloc != null_pointer_node)
4184 absolute = false;
4186 /* For a non-absolute relocation, there is no single
4187 variable that can be "the variable that determines the
4188 relocation." */
4189 return absolute ? null_pointer_node : error_mark_node;
4192 return TREE_STATIC (value) ? null_pointer_node : NULL_TREE;
4194 case INTEGER_CST:
4195 case VECTOR_CST:
4196 case REAL_CST:
4197 case FIXED_CST:
4198 case STRING_CST:
4199 case COMPLEX_CST:
4200 return null_pointer_node;
4202 case ADDR_EXPR:
4203 case FDESC_EXPR:
4205 tree op0 = staticp (TREE_OPERAND (value, 0));
4206 if (op0)
4208 /* "&(*a).f" is like unto pointer arithmetic. If "a" turns out
4209 to be a constant, this is old-skool offsetof-like nonsense. */
4210 if (TREE_CODE (op0) == INDIRECT_REF
4211 && TREE_CONSTANT (TREE_OPERAND (op0, 0)))
4212 return null_pointer_node;
4213 /* Taking the address of a nested function involves a trampoline,
4214 unless we don't need or want one. */
4215 if (TREE_CODE (op0) == FUNCTION_DECL
4216 && decl_function_context (op0)
4217 && !DECL_NO_STATIC_CHAIN (op0)
4218 && !TREE_NO_TRAMPOLINE (value))
4219 return NULL_TREE;
4220 /* "&{...}" requires a temporary to hold the constructed
4221 object. */
4222 if (TREE_CODE (op0) == CONSTRUCTOR)
4223 return NULL_TREE;
4225 return op0;
4228 case NON_LVALUE_EXPR:
4229 return initializer_constant_valid_p (TREE_OPERAND (value, 0), endtype);
4231 case VIEW_CONVERT_EXPR:
4233 tree src = TREE_OPERAND (value, 0);
4234 tree src_type = TREE_TYPE (src);
4235 tree dest_type = TREE_TYPE (value);
4237 /* Allow view-conversions from aggregate to non-aggregate type only
4238 if the bit pattern is fully preserved afterwards; otherwise, the
4239 RTL expander won't be able to apply a subsequent transformation
4240 to the underlying constructor. */
4241 if (AGGREGATE_TYPE_P (src_type) && !AGGREGATE_TYPE_P (dest_type))
4243 if (TYPE_MODE (endtype) == TYPE_MODE (dest_type))
4244 return initializer_constant_valid_p (src, endtype);
4245 else
4246 return NULL_TREE;
4249 /* Allow all other kinds of view-conversion. */
4250 return initializer_constant_valid_p (src, endtype);
4253 CASE_CONVERT:
4255 tree src = TREE_OPERAND (value, 0);
4256 tree src_type = TREE_TYPE (src);
4257 tree dest_type = TREE_TYPE (value);
4259 /* Allow conversions between pointer types, floating-point
4260 types, and offset types. */
4261 if ((POINTER_TYPE_P (dest_type) && POINTER_TYPE_P (src_type))
4262 || (FLOAT_TYPE_P (dest_type) && FLOAT_TYPE_P (src_type))
4263 || (TREE_CODE (dest_type) == OFFSET_TYPE
4264 && TREE_CODE (src_type) == OFFSET_TYPE))
4265 return initializer_constant_valid_p (src, endtype);
4267 /* Allow length-preserving conversions between integer types. */
4268 if (INTEGRAL_TYPE_P (dest_type) && INTEGRAL_TYPE_P (src_type)
4269 && (TYPE_PRECISION (dest_type) == TYPE_PRECISION (src_type)))
4270 return initializer_constant_valid_p (src, endtype);
4272 /* Allow conversions between other integer types only if
4273 explicit value. */
4274 if (INTEGRAL_TYPE_P (dest_type) && INTEGRAL_TYPE_P (src_type))
4276 tree inner = initializer_constant_valid_p (src, endtype);
4277 if (inner == null_pointer_node)
4278 return null_pointer_node;
4279 break;
4282 /* Allow (int) &foo provided int is as wide as a pointer. */
4283 if (INTEGRAL_TYPE_P (dest_type) && POINTER_TYPE_P (src_type)
4284 && (TYPE_PRECISION (dest_type) >= TYPE_PRECISION (src_type)))
4285 return initializer_constant_valid_p (src, endtype);
4287 /* Likewise conversions from int to pointers, but also allow
4288 conversions from 0. */
4289 if ((POINTER_TYPE_P (dest_type)
4290 || TREE_CODE (dest_type) == OFFSET_TYPE)
4291 && INTEGRAL_TYPE_P (src_type))
4293 if (TREE_CODE (src) == INTEGER_CST
4294 && TYPE_PRECISION (dest_type) >= TYPE_PRECISION (src_type))
4295 return null_pointer_node;
4296 if (integer_zerop (src))
4297 return null_pointer_node;
4298 else if (TYPE_PRECISION (dest_type) <= TYPE_PRECISION (src_type))
4299 return initializer_constant_valid_p (src, endtype);
4302 /* Allow conversions to struct or union types if the value
4303 inside is okay. */
4304 if (TREE_CODE (dest_type) == RECORD_TYPE
4305 || TREE_CODE (dest_type) == UNION_TYPE)
4306 return initializer_constant_valid_p (src, endtype);
4308 break;
4310 case POINTER_PLUS_EXPR:
4311 case PLUS_EXPR:
4312 if (! INTEGRAL_TYPE_P (endtype)
4313 || TYPE_PRECISION (endtype) >= POINTER_SIZE)
4315 tree valid0 = initializer_constant_valid_p (TREE_OPERAND (value, 0),
4316 endtype);
4317 tree valid1 = initializer_constant_valid_p (TREE_OPERAND (value, 1),
4318 endtype);
4319 /* If either term is absolute, use the other term's relocation. */
4320 if (valid0 == null_pointer_node)
4321 return valid1;
4322 if (valid1 == null_pointer_node)
4323 return valid0;
4326 /* Support narrowing pointer differences. */
4327 ret = narrowing_initializer_constant_valid_p (value, endtype);
4328 if (ret != NULL_TREE)
4329 return ret;
4331 break;
4333 case MINUS_EXPR:
4334 if (! INTEGRAL_TYPE_P (endtype)
4335 || TYPE_PRECISION (endtype) >= POINTER_SIZE)
4337 tree valid0 = initializer_constant_valid_p (TREE_OPERAND (value, 0),
4338 endtype);
4339 tree valid1 = initializer_constant_valid_p (TREE_OPERAND (value, 1),
4340 endtype);
4341 /* Win if second argument is absolute. */
4342 if (valid1 == null_pointer_node)
4343 return valid0;
4344 /* Win if both arguments have the same relocation.
4345 Then the value is absolute. */
4346 if (valid0 == valid1 && valid0 != 0)
4347 return null_pointer_node;
4349 /* Since GCC guarantees that string constants are unique in the
4350 generated code, a subtraction between two copies of the same
4351 constant string is absolute. */
4352 if (valid0 && TREE_CODE (valid0) == STRING_CST
4353 && valid1 && TREE_CODE (valid1) == STRING_CST
4354 && operand_equal_p (valid0, valid1, 1))
4355 return null_pointer_node;
4358 /* Support narrowing differences. */
4359 ret = narrowing_initializer_constant_valid_p (value, endtype);
4360 if (ret != NULL_TREE)
4361 return ret;
4363 break;
4365 default:
4366 break;
4369 return 0;
4372 /* Return true if VALUE is a valid constant-valued expression
4373 for use in initializing a static bit-field; one that can be
4374 an element of a "constant" initializer. */
4376 bool
4377 initializer_constant_valid_for_bitfield_p (tree value)
4379 /* For bitfields we support integer constants or possibly nested aggregates
4380 of such. */
4381 switch (TREE_CODE (value))
4383 case CONSTRUCTOR:
4385 unsigned HOST_WIDE_INT idx;
4386 tree elt;
4388 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (value), idx, elt)
4389 if (!initializer_constant_valid_for_bitfield_p (elt))
4390 return false;
4391 return true;
4394 case INTEGER_CST:
4395 return true;
4397 case VIEW_CONVERT_EXPR:
4398 case NON_LVALUE_EXPR:
4399 return
4400 initializer_constant_valid_for_bitfield_p (TREE_OPERAND (value, 0));
4402 default:
4403 break;
4406 return false;
4409 /* output_constructor outer state of relevance in recursive calls, typically
4410 for nested aggregate bitfields. */
4412 typedef struct {
4413 unsigned int bit_offset; /* current position in ... */
4414 int byte; /* ... the outer byte buffer. */
4415 } oc_outer_state;
4417 static unsigned HOST_WIDE_INT
4418 output_constructor (tree, unsigned HOST_WIDE_INT, unsigned int,
4419 oc_outer_state *);
4421 /* Output assembler code for constant EXP to FILE, with no label.
4422 This includes the pseudo-op such as ".int" or ".byte", and a newline.
4423 Assumes output_addressed_constants has been done on EXP already.
4425 Generate exactly SIZE bytes of assembler data, padding at the end
4426 with zeros if necessary. SIZE must always be specified.
4428 SIZE is important for structure constructors,
4429 since trailing members may have been omitted from the constructor.
4430 It is also important for initialization of arrays from string constants
4431 since the full length of the string constant might not be wanted.
4432 It is also needed for initialization of unions, where the initializer's
4433 type is just one member, and that may not be as long as the union.
4435 There a case in which we would fail to output exactly SIZE bytes:
4436 for a structure constructor that wants to produce more than SIZE bytes.
4437 But such constructors will never be generated for any possible input.
4439 ALIGN is the alignment of the data in bits. */
4441 void
4442 output_constant (tree exp, unsigned HOST_WIDE_INT size, unsigned int align)
4444 enum tree_code code;
4445 unsigned HOST_WIDE_INT thissize;
4447 if (size == 0 || flag_syntax_only)
4448 return;
4450 /* See if we're trying to initialize a pointer in a non-default mode
4451 to the address of some declaration somewhere. If the target says
4452 the mode is valid for pointers, assume the target has a way of
4453 resolving it. */
4454 if (TREE_CODE (exp) == NOP_EXPR
4455 && POINTER_TYPE_P (TREE_TYPE (exp))
4456 && targetm.valid_pointer_mode (TYPE_MODE (TREE_TYPE (exp))))
4458 tree saved_type = TREE_TYPE (exp);
4460 /* Peel off any intermediate conversions-to-pointer for valid
4461 pointer modes. */
4462 while (TREE_CODE (exp) == NOP_EXPR
4463 && POINTER_TYPE_P (TREE_TYPE (exp))
4464 && targetm.valid_pointer_mode (TYPE_MODE (TREE_TYPE (exp))))
4465 exp = TREE_OPERAND (exp, 0);
4467 /* If what we're left with is the address of something, we can
4468 convert the address to the final type and output it that
4469 way. */
4470 if (TREE_CODE (exp) == ADDR_EXPR)
4471 exp = build1 (ADDR_EXPR, saved_type, TREE_OPERAND (exp, 0));
4472 /* Likewise for constant ints. */
4473 else if (TREE_CODE (exp) == INTEGER_CST)
4474 exp = build_int_cst_wide (saved_type, TREE_INT_CST_LOW (exp),
4475 TREE_INT_CST_HIGH (exp));
4479 /* Eliminate any conversions since we'll be outputting the underlying
4480 constant. */
4481 while (CONVERT_EXPR_P (exp)
4482 || TREE_CODE (exp) == NON_LVALUE_EXPR
4483 || TREE_CODE (exp) == VIEW_CONVERT_EXPR)
4485 HOST_WIDE_INT type_size = int_size_in_bytes (TREE_TYPE (exp));
4486 HOST_WIDE_INT op_size = int_size_in_bytes (TREE_TYPE (TREE_OPERAND (exp, 0)));
4488 /* Make sure eliminating the conversion is really a no-op, except with
4489 VIEW_CONVERT_EXPRs to allow for wild Ada unchecked conversions and
4490 union types to allow for Ada unchecked unions. */
4491 if (type_size > op_size
4492 && TREE_CODE (exp) != VIEW_CONVERT_EXPR
4493 && TREE_CODE (TREE_TYPE (exp)) != UNION_TYPE)
4494 /* Keep the conversion. */
4495 break;
4496 else
4497 exp = TREE_OPERAND (exp, 0);
4500 code = TREE_CODE (TREE_TYPE (exp));
4501 thissize = int_size_in_bytes (TREE_TYPE (exp));
4503 /* Allow a constructor with no elements for any data type.
4504 This means to fill the space with zeros. */
4505 if (TREE_CODE (exp) == CONSTRUCTOR
4506 && VEC_empty (constructor_elt, CONSTRUCTOR_ELTS (exp)))
4508 assemble_zeros (size);
4509 return;
4512 if (TREE_CODE (exp) == FDESC_EXPR)
4514 #ifdef ASM_OUTPUT_FDESC
4515 HOST_WIDE_INT part = tree_low_cst (TREE_OPERAND (exp, 1), 0);
4516 tree decl = TREE_OPERAND (exp, 0);
4517 ASM_OUTPUT_FDESC (asm_out_file, decl, part);
4518 #else
4519 gcc_unreachable ();
4520 #endif
4521 return;
4524 /* Now output the underlying data. If we've handling the padding, return.
4525 Otherwise, break and ensure SIZE is the size written. */
4526 switch (code)
4528 case BOOLEAN_TYPE:
4529 case INTEGER_TYPE:
4530 case ENUMERAL_TYPE:
4531 case POINTER_TYPE:
4532 case REFERENCE_TYPE:
4533 case OFFSET_TYPE:
4534 case FIXED_POINT_TYPE:
4535 if (! assemble_integer (expand_expr (exp, NULL_RTX, VOIDmode,
4536 EXPAND_INITIALIZER),
4537 MIN (size, thissize), align, 0))
4538 error ("initializer for integer/fixed-point value is too complicated");
4539 break;
4541 case REAL_TYPE:
4542 if (TREE_CODE (exp) != REAL_CST)
4543 error ("initializer for floating value is not a floating constant");
4545 assemble_real (TREE_REAL_CST (exp), TYPE_MODE (TREE_TYPE (exp)), align);
4546 break;
4548 case COMPLEX_TYPE:
4549 output_constant (TREE_REALPART (exp), thissize / 2, align);
4550 output_constant (TREE_IMAGPART (exp), thissize / 2,
4551 min_align (align, BITS_PER_UNIT * (thissize / 2)));
4552 break;
4554 case ARRAY_TYPE:
4555 case VECTOR_TYPE:
4556 switch (TREE_CODE (exp))
4558 case CONSTRUCTOR:
4559 output_constructor (exp, size, align, NULL);
4560 return;
4561 case STRING_CST:
4562 thissize = MIN ((unsigned HOST_WIDE_INT)TREE_STRING_LENGTH (exp),
4563 size);
4564 assemble_string (TREE_STRING_POINTER (exp), thissize);
4565 break;
4567 case VECTOR_CST:
4569 int elt_size;
4570 tree link;
4571 unsigned int nalign;
4572 enum machine_mode inner;
4574 inner = TYPE_MODE (TREE_TYPE (TREE_TYPE (exp)));
4575 nalign = MIN (align, GET_MODE_ALIGNMENT (inner));
4577 elt_size = GET_MODE_SIZE (inner);
4579 link = TREE_VECTOR_CST_ELTS (exp);
4580 output_constant (TREE_VALUE (link), elt_size, align);
4581 thissize = elt_size;
4582 while ((link = TREE_CHAIN (link)) != NULL)
4584 output_constant (TREE_VALUE (link), elt_size, nalign);
4585 thissize += elt_size;
4587 break;
4589 default:
4590 gcc_unreachable ();
4592 break;
4594 case RECORD_TYPE:
4595 case UNION_TYPE:
4596 gcc_assert (TREE_CODE (exp) == CONSTRUCTOR);
4597 output_constructor (exp, size, align, NULL);
4598 return;
4600 case ERROR_MARK:
4601 return;
4603 default:
4604 gcc_unreachable ();
4607 if (size > thissize)
4608 assemble_zeros (size - thissize);
4612 /* Subroutine of output_constructor, used for computing the size of
4613 arrays of unspecified length. VAL must be a CONSTRUCTOR of an array
4614 type with an unspecified upper bound. */
4616 static unsigned HOST_WIDE_INT
4617 array_size_for_constructor (tree val)
4619 tree max_index, i;
4620 unsigned HOST_WIDE_INT cnt;
4621 tree index, value, tmp;
4623 /* This code used to attempt to handle string constants that are not
4624 arrays of single-bytes, but nothing else does, so there's no point in
4625 doing it here. */
4626 if (TREE_CODE (val) == STRING_CST)
4627 return TREE_STRING_LENGTH (val);
4629 max_index = NULL_TREE;
4630 FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (val), cnt, index, value)
4632 if (TREE_CODE (index) == RANGE_EXPR)
4633 index = TREE_OPERAND (index, 1);
4634 if (max_index == NULL_TREE || tree_int_cst_lt (max_index, index))
4635 max_index = index;
4638 if (max_index == NULL_TREE)
4639 return 0;
4641 /* Compute the total number of array elements. */
4642 tmp = TYPE_MIN_VALUE (TYPE_DOMAIN (TREE_TYPE (val)));
4643 i = size_binop (MINUS_EXPR, fold_convert (sizetype, max_index),
4644 fold_convert (sizetype, tmp));
4645 i = size_binop (PLUS_EXPR, i, build_int_cst (sizetype, 1));
4647 /* Multiply by the array element unit size to find number of bytes. */
4648 i = size_binop (MULT_EXPR, i, TYPE_SIZE_UNIT (TREE_TYPE (TREE_TYPE (val))));
4650 return tree_low_cst (i, 1);
4653 /* Other datastructures + helpers for output_constructor. */
4655 /* output_constructor local state to support interaction with helpers. */
4657 typedef struct {
4659 /* Received arguments. */
4660 tree exp; /* Constructor expression. */
4661 unsigned HOST_WIDE_INT size; /* # bytes to output - pad if necessary. */
4662 unsigned int align; /* Known initial alignment. */
4664 /* Constructor expression data. */
4665 tree type; /* Expression type. */
4666 tree field; /* Current field decl in a record. */
4667 tree min_index; /* Lower bound if specified for an array. */
4669 /* Output processing state. */
4670 HOST_WIDE_INT total_bytes; /* # bytes output so far / current position. */
4671 bool byte_buffer_in_use; /* Whether byte ... */
4672 int byte; /* ... contains part of a bitfield byte yet to
4673 be output. */
4675 int last_relative_index; /* Implicit or explicit index of the last
4676 array element output within a bitfield. */
4677 /* Current element. */
4678 tree val; /* Current element value. */
4679 tree index; /* Current element index. */
4681 } oc_local_state;
4683 /* Helper for output_constructor. From the current LOCAL state, output a
4684 RANGE_EXPR element. */
4686 static void
4687 output_constructor_array_range (oc_local_state *local)
4689 unsigned HOST_WIDE_INT fieldsize
4690 = int_size_in_bytes (TREE_TYPE (local->type));
4692 HOST_WIDE_INT lo_index
4693 = tree_low_cst (TREE_OPERAND (local->index, 0), 0);
4694 HOST_WIDE_INT hi_index
4695 = tree_low_cst (TREE_OPERAND (local->index, 1), 0);
4696 HOST_WIDE_INT index;
4698 unsigned int align2
4699 = min_align (local->align, fieldsize * BITS_PER_UNIT);
4701 for (index = lo_index; index <= hi_index; index++)
4703 /* Output the element's initial value. */
4704 if (local->val == NULL_TREE)
4705 assemble_zeros (fieldsize);
4706 else
4707 output_constant (local->val, fieldsize, align2);
4709 /* Count its size. */
4710 local->total_bytes += fieldsize;
4714 /* Helper for output_constructor. From the current LOCAL state, output a
4715 field element that is not true bitfield or part of an outer one. */
4717 static void
4718 output_constructor_regular_field (oc_local_state *local)
4720 /* Field size and position. Since this structure is static, we know the
4721 positions are constant. */
4722 unsigned HOST_WIDE_INT fieldsize;
4723 HOST_WIDE_INT fieldpos;
4725 unsigned int align2;
4727 if (local->index != NULL_TREE)
4728 fieldpos = (tree_low_cst (TYPE_SIZE_UNIT (TREE_TYPE (local->val)), 1)
4729 * ((tree_low_cst (local->index, 0)
4730 - tree_low_cst (local->min_index, 0))));
4731 else if (local->field != NULL_TREE)
4732 fieldpos = int_byte_position (local->field);
4733 else
4734 fieldpos = 0;
4736 /* Output any buffered-up bit-fields preceding this element. */
4737 if (local->byte_buffer_in_use)
4739 assemble_integer (GEN_INT (local->byte), 1, BITS_PER_UNIT, 1);
4740 local->total_bytes++;
4741 local->byte_buffer_in_use = false;
4744 /* Advance to offset of this element.
4745 Note no alignment needed in an array, since that is guaranteed
4746 if each element has the proper size. */
4747 if ((local->field != NULL_TREE || local->index != NULL_TREE)
4748 && fieldpos != local->total_bytes)
4750 gcc_assert (fieldpos >= local->total_bytes);
4751 assemble_zeros (fieldpos - local->total_bytes);
4752 local->total_bytes = fieldpos;
4755 /* Find the alignment of this element. */
4756 align2 = min_align (local->align, BITS_PER_UNIT * fieldpos);
4758 /* Determine size this element should occupy. */
4759 if (local->field)
4761 fieldsize = 0;
4763 /* If this is an array with an unspecified upper bound,
4764 the initializer determines the size. */
4765 /* ??? This ought to only checked if DECL_SIZE_UNIT is NULL,
4766 but we cannot do this until the deprecated support for
4767 initializing zero-length array members is removed. */
4768 if (TREE_CODE (TREE_TYPE (local->field)) == ARRAY_TYPE
4769 && TYPE_DOMAIN (TREE_TYPE (local->field))
4770 && ! TYPE_MAX_VALUE (TYPE_DOMAIN (TREE_TYPE (local->field))))
4772 fieldsize = array_size_for_constructor (local->val);
4773 /* Given a non-empty initialization, this field had
4774 better be last. */
4775 gcc_assert (!fieldsize || !TREE_CHAIN (local->field));
4777 else if (DECL_SIZE_UNIT (local->field))
4779 /* ??? This can't be right. If the decl size overflows
4780 a host integer we will silently emit no data. */
4781 if (host_integerp (DECL_SIZE_UNIT (local->field), 1))
4782 fieldsize = tree_low_cst (DECL_SIZE_UNIT (local->field), 1);
4785 else
4786 fieldsize = int_size_in_bytes (TREE_TYPE (local->type));
4788 /* Output the element's initial value. */
4789 if (local->val == NULL_TREE)
4790 assemble_zeros (fieldsize);
4791 else
4792 output_constant (local->val, fieldsize, align2);
4794 /* Count its size. */
4795 local->total_bytes += fieldsize;
4798 /* Helper for output_constructor. From the current LOCAL and OUTER states,
4799 output an element that is a true bitfield or part of an outer one. */
4801 static void
4802 output_constructor_bitfield (oc_local_state *local, oc_outer_state *outer)
4804 /* Bit size of this element. */
4805 HOST_WIDE_INT ebitsize
4806 = (local->field
4807 ? tree_low_cst (DECL_SIZE (local->field), 1)
4808 : tree_low_cst (TYPE_SIZE (TREE_TYPE (local->type)), 1));
4810 /* Relative index of this element if this is an array component. */
4811 HOST_WIDE_INT relative_index
4812 = (!local->field
4813 ? (local->index
4814 ? (tree_low_cst (local->index, 0)
4815 - tree_low_cst (local->min_index, 0))
4816 : local->last_relative_index + 1)
4817 : 0);
4819 /* Bit position of this element from the start of the containing
4820 constructor. */
4821 HOST_WIDE_INT constructor_relative_ebitpos
4822 = (local->field
4823 ? int_bit_position (local->field)
4824 : ebitsize * relative_index);
4826 /* Bit position of this element from the start of a possibly ongoing
4827 outer byte buffer. */
4828 HOST_WIDE_INT byte_relative_ebitpos
4829 = ((outer ? outer->bit_offset : 0) + constructor_relative_ebitpos);
4831 /* From the start of a possibly ongoing outer byte buffer, offsets to
4832 the first bit of this element and to the first bit past the end of
4833 this element. */
4834 HOST_WIDE_INT next_offset = byte_relative_ebitpos;
4835 HOST_WIDE_INT end_offset = byte_relative_ebitpos + ebitsize;
4837 local->last_relative_index = relative_index;
4839 if (local->val == NULL_TREE)
4840 local->val = integer_zero_node;
4842 while (TREE_CODE (local->val) == VIEW_CONVERT_EXPR
4843 || TREE_CODE (local->val) == NON_LVALUE_EXPR)
4844 local->val = TREE_OPERAND (local->val, 0);
4846 if (TREE_CODE (local->val) != INTEGER_CST
4847 && TREE_CODE (local->val) != CONSTRUCTOR)
4849 error ("invalid initial value for member %qE", DECL_NAME (local->field));
4850 return;
4853 /* If this field does not start in this (or, next) byte,
4854 skip some bytes. */
4855 if (next_offset / BITS_PER_UNIT != local->total_bytes)
4857 /* Output remnant of any bit field in previous bytes. */
4858 if (local->byte_buffer_in_use)
4860 assemble_integer (GEN_INT (local->byte), 1, BITS_PER_UNIT, 1);
4861 local->total_bytes++;
4862 local->byte_buffer_in_use = false;
4865 /* If still not at proper byte, advance to there. */
4866 if (next_offset / BITS_PER_UNIT != local->total_bytes)
4868 gcc_assert (next_offset / BITS_PER_UNIT >= local->total_bytes);
4869 assemble_zeros (next_offset / BITS_PER_UNIT - local->total_bytes);
4870 local->total_bytes = next_offset / BITS_PER_UNIT;
4874 /* Set up the buffer if necessary. */
4875 if (!local->byte_buffer_in_use)
4877 local->byte = 0;
4878 if (ebitsize > 0)
4879 local->byte_buffer_in_use = true;
4882 /* If this is nested constructor, recurse passing the bit offset and the
4883 pending data, then retrieve the new pending data afterwards. */
4884 if (TREE_CODE (local->val) == CONSTRUCTOR)
4886 oc_outer_state output_state;
4888 output_state.bit_offset = next_offset % BITS_PER_UNIT;
4889 output_state.byte = local->byte;
4890 local->total_bytes
4891 += output_constructor (local->val, 0, 0, &output_state);
4892 local->byte = output_state.byte;
4893 return;
4896 /* Otherwise, we must split the element into pieces that fall within
4897 separate bytes, and combine each byte with previous or following
4898 bit-fields. */
4899 while (next_offset < end_offset)
4901 int this_time;
4902 int shift;
4903 HOST_WIDE_INT value;
4904 HOST_WIDE_INT next_byte = next_offset / BITS_PER_UNIT;
4905 HOST_WIDE_INT next_bit = next_offset % BITS_PER_UNIT;
4907 /* Advance from byte to byte
4908 within this element when necessary. */
4909 while (next_byte != local->total_bytes)
4911 assemble_integer (GEN_INT (local->byte), 1, BITS_PER_UNIT, 1);
4912 local->total_bytes++;
4913 local->byte = 0;
4916 /* Number of bits we can process at once
4917 (all part of the same byte). */
4918 this_time = MIN (end_offset - next_offset,
4919 BITS_PER_UNIT - next_bit);
4920 if (BYTES_BIG_ENDIAN)
4922 /* On big-endian machine, take the most significant bits
4923 first (of the bits that are significant)
4924 and put them into bytes from the most significant end. */
4925 shift = end_offset - next_offset - this_time;
4927 /* Don't try to take a bunch of bits that cross
4928 the word boundary in the INTEGER_CST. We can
4929 only select bits from the LOW or HIGH part
4930 not from both. */
4931 if (shift < HOST_BITS_PER_WIDE_INT
4932 && shift + this_time > HOST_BITS_PER_WIDE_INT)
4934 this_time = shift + this_time - HOST_BITS_PER_WIDE_INT;
4935 shift = HOST_BITS_PER_WIDE_INT;
4938 /* Now get the bits from the appropriate constant word. */
4939 if (shift < HOST_BITS_PER_WIDE_INT)
4940 value = TREE_INT_CST_LOW (local->val);
4941 else
4943 gcc_assert (shift < 2 * HOST_BITS_PER_WIDE_INT);
4944 value = TREE_INT_CST_HIGH (local->val);
4945 shift -= HOST_BITS_PER_WIDE_INT;
4948 /* Get the result. This works only when:
4949 1 <= this_time <= HOST_BITS_PER_WIDE_INT. */
4950 local->byte |= (((value >> shift)
4951 & (((HOST_WIDE_INT) 2 << (this_time - 1)) - 1))
4952 << (BITS_PER_UNIT - this_time - next_bit));
4954 else
4956 /* On little-endian machines,
4957 take first the least significant bits of the value
4958 and pack them starting at the least significant
4959 bits of the bytes. */
4960 shift = next_offset - byte_relative_ebitpos;
4962 /* Don't try to take a bunch of bits that cross
4963 the word boundary in the INTEGER_CST. We can
4964 only select bits from the LOW or HIGH part
4965 not from both. */
4966 if (shift < HOST_BITS_PER_WIDE_INT
4967 && shift + this_time > HOST_BITS_PER_WIDE_INT)
4968 this_time = (HOST_BITS_PER_WIDE_INT - shift);
4970 /* Now get the bits from the appropriate constant word. */
4971 if (shift < HOST_BITS_PER_WIDE_INT)
4972 value = TREE_INT_CST_LOW (local->val);
4973 else
4975 gcc_assert (shift < 2 * HOST_BITS_PER_WIDE_INT);
4976 value = TREE_INT_CST_HIGH (local->val);
4977 shift -= HOST_BITS_PER_WIDE_INT;
4980 /* Get the result. This works only when:
4981 1 <= this_time <= HOST_BITS_PER_WIDE_INT. */
4982 local->byte |= (((value >> shift)
4983 & (((HOST_WIDE_INT) 2 << (this_time - 1)) - 1))
4984 << next_bit);
4987 next_offset += this_time;
4988 local->byte_buffer_in_use = true;
4992 /* Subroutine of output_constant, used for CONSTRUCTORs (aggregate constants).
4993 Generate at least SIZE bytes, padding if necessary. OUTER designates the
4994 caller output state of relevance in recursive invocations. */
4996 static unsigned HOST_WIDE_INT
4997 output_constructor (tree exp, unsigned HOST_WIDE_INT size,
4998 unsigned int align, oc_outer_state * outer)
5000 unsigned HOST_WIDE_INT cnt;
5001 constructor_elt *ce;
5003 oc_local_state local;
5005 /* Setup our local state to communicate with helpers. */
5006 local.exp = exp;
5007 local.size = size;
5008 local.align = align;
5010 local.total_bytes = 0;
5011 local.byte_buffer_in_use = outer != NULL;
5012 local.byte = outer ? outer->byte : 0;
5014 local.type = TREE_TYPE (exp);
5016 local.last_relative_index = -1;
5018 local.min_index = NULL_TREE;
5019 if (TREE_CODE (local.type) == ARRAY_TYPE
5020 && TYPE_DOMAIN (local.type) != NULL_TREE)
5021 local.min_index = TYPE_MIN_VALUE (TYPE_DOMAIN (local.type));
5023 gcc_assert (HOST_BITS_PER_WIDE_INT >= BITS_PER_UNIT);
5025 /* As CE goes through the elements of the constant, FIELD goes through the
5026 structure fields if the constant is a structure. If the constant is a
5027 union, we override this by getting the field from the TREE_LIST element.
5028 But the constant could also be an array. Then FIELD is zero.
5030 There is always a maximum of one element in the chain LINK for unions
5031 (even if the initializer in a source program incorrectly contains
5032 more one). */
5034 local.field = NULL_TREE;
5035 if (TREE_CODE (local.type) == RECORD_TYPE)
5036 local.field = TYPE_FIELDS (local.type);
5038 for (cnt = 0;
5039 VEC_iterate (constructor_elt, CONSTRUCTOR_ELTS (exp), cnt, ce);
5040 cnt++, local.field = local.field ? TREE_CHAIN (local.field) : 0)
5042 local.val = ce->value;
5043 local.index = NULL_TREE;
5045 /* The element in a union constructor specifies the proper field
5046 or index. */
5047 if ((TREE_CODE (local.type) == RECORD_TYPE
5048 || TREE_CODE (local.type) == UNION_TYPE
5049 || TREE_CODE (local.type) == QUAL_UNION_TYPE)
5050 && ce->index != NULL_TREE)
5051 local.field = ce->index;
5053 else if (TREE_CODE (local.type) == ARRAY_TYPE)
5054 local.index = ce->index;
5056 #ifdef ASM_COMMENT_START
5057 if (local.field && flag_verbose_asm)
5058 fprintf (asm_out_file, "%s %s:\n",
5059 ASM_COMMENT_START,
5060 DECL_NAME (local.field)
5061 ? IDENTIFIER_POINTER (DECL_NAME (local.field))
5062 : "<anonymous>");
5063 #endif
5065 /* Eliminate the marker that makes a cast not be an lvalue. */
5066 if (local.val != NULL_TREE)
5067 STRIP_NOPS (local.val);
5069 /* Output the current element, using the appropriate helper ... */
5071 /* For an array slice not part of an outer bitfield. */
5072 if (!outer
5073 && local.index != NULL_TREE
5074 && TREE_CODE (local.index) == RANGE_EXPR)
5075 output_constructor_array_range (&local);
5077 /* For a field that is neither a true bitfield nor part of an outer one,
5078 known to be at least byte aligned and multiple-of-bytes long. */
5079 else if (!outer
5080 && (local.field == NULL_TREE
5081 || !CONSTRUCTOR_BITFIELD_P (local.field)))
5082 output_constructor_regular_field (&local);
5084 /* For a true bitfield or part of an outer one. */
5085 else
5086 output_constructor_bitfield (&local, outer);
5089 /* If we are not at toplevel, save the pending data for our caller.
5090 Otherwise output the pending data and padding zeros as needed. */
5091 if (outer)
5092 outer->byte = local.byte;
5093 else
5095 if (local.byte_buffer_in_use)
5097 assemble_integer (GEN_INT (local.byte), 1, BITS_PER_UNIT, 1);
5098 local.total_bytes++;
5101 if ((unsigned HOST_WIDE_INT)local.total_bytes < local.size)
5103 assemble_zeros (local.size - local.total_bytes);
5104 local.total_bytes = local.size;
5108 return local.total_bytes;
5111 /* Mark DECL as weak. */
5113 static void
5114 mark_weak (tree decl)
5116 DECL_WEAK (decl) = 1;
5118 if (DECL_RTL_SET_P (decl)
5119 && MEM_P (DECL_RTL (decl))
5120 && XEXP (DECL_RTL (decl), 0)
5121 && GET_CODE (XEXP (DECL_RTL (decl), 0)) == SYMBOL_REF)
5122 SYMBOL_REF_WEAK (XEXP (DECL_RTL (decl), 0)) = 1;
5125 /* Merge weak status between NEWDECL and OLDDECL. */
5127 void
5128 merge_weak (tree newdecl, tree olddecl)
5130 if (DECL_WEAK (newdecl) == DECL_WEAK (olddecl))
5132 if (DECL_WEAK (newdecl) && SUPPORTS_WEAK)
5134 tree *pwd;
5135 /* We put the NEWDECL on the weak_decls list at some point
5136 and OLDDECL as well. Keep just OLDDECL on the list. */
5137 for (pwd = &weak_decls; *pwd; pwd = &TREE_CHAIN (*pwd))
5138 if (TREE_VALUE (*pwd) == newdecl)
5140 *pwd = TREE_CHAIN (*pwd);
5141 break;
5144 return;
5147 if (DECL_WEAK (newdecl))
5149 tree wd;
5151 /* NEWDECL is weak, but OLDDECL is not. */
5153 /* If we already output the OLDDECL, we're in trouble; we can't
5154 go back and make it weak. This error cannot be caught in
5155 declare_weak because the NEWDECL and OLDDECL was not yet
5156 been merged; therefore, TREE_ASM_WRITTEN was not set. */
5157 if (TREE_ASM_WRITTEN (olddecl))
5158 error ("weak declaration of %q+D must precede definition",
5159 newdecl);
5161 /* If we've already generated rtl referencing OLDDECL, we may
5162 have done so in a way that will not function properly with
5163 a weak symbol. */
5164 else if (TREE_USED (olddecl)
5165 && TREE_SYMBOL_REFERENCED (DECL_ASSEMBLER_NAME (olddecl)))
5166 warning (0, "weak declaration of %q+D after first use results "
5167 "in unspecified behavior", newdecl);
5169 if (SUPPORTS_WEAK)
5171 /* We put the NEWDECL on the weak_decls list at some point.
5172 Replace it with the OLDDECL. */
5173 for (wd = weak_decls; wd; wd = TREE_CHAIN (wd))
5174 if (TREE_VALUE (wd) == newdecl)
5176 TREE_VALUE (wd) = olddecl;
5177 break;
5179 /* We may not find the entry on the list. If NEWDECL is a
5180 weak alias, then we will have already called
5181 globalize_decl to remove the entry; in that case, we do
5182 not need to do anything. */
5185 /* Make the OLDDECL weak; it's OLDDECL that we'll be keeping. */
5186 mark_weak (olddecl);
5188 else
5189 /* OLDDECL was weak, but NEWDECL was not explicitly marked as
5190 weak. Just update NEWDECL to indicate that it's weak too. */
5191 mark_weak (newdecl);
5194 /* Declare DECL to be a weak symbol. */
5196 void
5197 declare_weak (tree decl)
5199 if (! TREE_PUBLIC (decl))
5200 error ("weak declaration of %q+D must be public", decl);
5201 else if (TREE_CODE (decl) == FUNCTION_DECL && TREE_ASM_WRITTEN (decl))
5202 error ("weak declaration of %q+D must precede definition", decl);
5203 else if (!SUPPORTS_WEAK)
5204 warning (0, "weak declaration of %q+D not supported", decl);
5206 mark_weak (decl);
5209 static void
5210 weak_finish_1 (tree decl)
5212 #if defined (ASM_WEAKEN_DECL) || defined (ASM_WEAKEN_LABEL)
5213 const char *const name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
5214 #endif
5216 if (! TREE_USED (decl))
5217 return;
5219 #ifdef ASM_WEAKEN_DECL
5220 ASM_WEAKEN_DECL (asm_out_file, decl, name, NULL);
5221 #else
5222 #ifdef ASM_WEAKEN_LABEL
5223 ASM_WEAKEN_LABEL (asm_out_file, name);
5224 #else
5225 #ifdef ASM_OUTPUT_WEAK_ALIAS
5227 static bool warn_once = 0;
5228 if (! warn_once)
5230 warning (0, "only weak aliases are supported in this configuration");
5231 warn_once = 1;
5233 return;
5235 #endif
5236 #endif
5237 #endif
5240 /* This TREE_LIST contains weakref targets. */
5242 static GTY(()) tree weakref_targets;
5244 /* Forward declaration. */
5245 static tree find_decl_and_mark_needed (tree decl, tree target);
5247 /* Emit any pending weak declarations. */
5249 void
5250 weak_finish (void)
5252 tree t;
5254 for (t = weakref_targets; t; t = TREE_CHAIN (t))
5256 tree alias_decl = TREE_PURPOSE (t);
5257 tree target = ultimate_transparent_alias_target (&TREE_VALUE (t));
5259 if (! TREE_SYMBOL_REFERENCED (DECL_ASSEMBLER_NAME (alias_decl)))
5260 /* Remove alias_decl from the weak list, but leave entries for
5261 the target alone. */
5262 target = NULL_TREE;
5263 #ifndef ASM_OUTPUT_WEAKREF
5264 else if (! TREE_SYMBOL_REFERENCED (target))
5266 /* Use ASM_WEAKEN_LABEL only if ASM_WEAKEN_DECL is not
5267 defined, otherwise we and weak_finish_1 would use
5268 different macros. */
5269 # if defined ASM_WEAKEN_LABEL && ! defined ASM_WEAKEN_DECL
5270 ASM_WEAKEN_LABEL (asm_out_file, IDENTIFIER_POINTER (target));
5271 # else
5272 tree decl = find_decl_and_mark_needed (alias_decl, target);
5274 if (! decl)
5276 decl = build_decl (DECL_SOURCE_LOCATION (alias_decl),
5277 TREE_CODE (alias_decl), target,
5278 TREE_TYPE (alias_decl));
5280 DECL_EXTERNAL (decl) = 1;
5281 TREE_PUBLIC (decl) = 1;
5282 DECL_ARTIFICIAL (decl) = 1;
5283 TREE_NOTHROW (decl) = TREE_NOTHROW (alias_decl);
5284 TREE_USED (decl) = 1;
5287 weak_finish_1 (decl);
5288 # endif
5290 #endif
5293 tree *p;
5294 tree t2;
5296 /* Remove the alias and the target from the pending weak list
5297 so that we do not emit any .weak directives for the former,
5298 nor multiple .weak directives for the latter. */
5299 for (p = &weak_decls; (t2 = *p) ; )
5301 if (TREE_VALUE (t2) == alias_decl
5302 || target == DECL_ASSEMBLER_NAME (TREE_VALUE (t2)))
5303 *p = TREE_CHAIN (t2);
5304 else
5305 p = &TREE_CHAIN (t2);
5308 /* Remove other weakrefs to the same target, to speed things up. */
5309 for (p = &TREE_CHAIN (t); (t2 = *p) ; )
5311 if (target == ultimate_transparent_alias_target (&TREE_VALUE (t2)))
5312 *p = TREE_CHAIN (t2);
5313 else
5314 p = &TREE_CHAIN (t2);
5319 for (t = weak_decls; t; t = TREE_CHAIN (t))
5321 tree decl = TREE_VALUE (t);
5323 weak_finish_1 (decl);
5327 /* Emit the assembly bits to indicate that DECL is globally visible. */
5329 static void
5330 globalize_decl (tree decl)
5333 #if defined (ASM_WEAKEN_LABEL) || defined (ASM_WEAKEN_DECL)
5334 if (DECL_WEAK (decl))
5336 const char *name = XSTR (XEXP (DECL_RTL (decl), 0), 0);
5337 tree *p, t;
5339 #ifdef ASM_WEAKEN_DECL
5340 ASM_WEAKEN_DECL (asm_out_file, decl, name, 0);
5341 #else
5342 ASM_WEAKEN_LABEL (asm_out_file, name);
5343 #endif
5345 /* Remove this function from the pending weak list so that
5346 we do not emit multiple .weak directives for it. */
5347 for (p = &weak_decls; (t = *p) ; )
5349 if (DECL_ASSEMBLER_NAME (decl) == DECL_ASSEMBLER_NAME (TREE_VALUE (t)))
5350 *p = TREE_CHAIN (t);
5351 else
5352 p = &TREE_CHAIN (t);
5355 /* Remove weakrefs to the same target from the pending weakref
5356 list, for the same reason. */
5357 for (p = &weakref_targets; (t = *p) ; )
5359 if (DECL_ASSEMBLER_NAME (decl)
5360 == ultimate_transparent_alias_target (&TREE_VALUE (t)))
5361 *p = TREE_CHAIN (t);
5362 else
5363 p = &TREE_CHAIN (t);
5366 return;
5368 #endif
5370 targetm.asm_out.globalize_decl_name (asm_out_file, decl);
5373 VEC(alias_pair,gc) *alias_pairs;
5375 /* Given an assembly name, find the decl it is associated with. At the
5376 same time, mark it needed for cgraph. */
5378 static tree
5379 find_decl_and_mark_needed (tree decl, tree target)
5381 struct cgraph_node *fnode = NULL;
5382 struct varpool_node *vnode = NULL;
5384 if (TREE_CODE (decl) == FUNCTION_DECL)
5386 fnode = cgraph_node_for_asm (target);
5387 if (fnode == NULL)
5388 vnode = varpool_node_for_asm (target);
5390 else
5392 vnode = varpool_node_for_asm (target);
5393 if (vnode == NULL)
5394 fnode = cgraph_node_for_asm (target);
5397 if (fnode)
5399 cgraph_mark_needed_node (fnode);
5400 return fnode->decl;
5402 else if (vnode)
5404 varpool_mark_needed_node (vnode);
5405 return vnode->decl;
5407 else
5408 return NULL_TREE;
5411 /* Output the assembler code for a define (equate) using ASM_OUTPUT_DEF
5412 or ASM_OUTPUT_DEF_FROM_DECLS. The function defines the symbol whose
5413 tree node is DECL to have the value of the tree node TARGET. */
5415 static void
5416 do_assemble_alias (tree decl, tree target)
5418 if (TREE_ASM_WRITTEN (decl))
5419 return;
5421 TREE_ASM_WRITTEN (decl) = 1;
5422 TREE_ASM_WRITTEN (DECL_ASSEMBLER_NAME (decl)) = 1;
5424 if (lookup_attribute ("weakref", DECL_ATTRIBUTES (decl)))
5426 ultimate_transparent_alias_target (&target);
5428 if (!targetm.have_tls
5429 && TREE_CODE (decl) == VAR_DECL
5430 && DECL_THREAD_LOCAL_P (decl))
5432 decl = emutls_decl (decl);
5433 target = get_emutls_object_name (target);
5436 if (!TREE_SYMBOL_REFERENCED (target))
5437 weakref_targets = tree_cons (decl, target, weakref_targets);
5439 #ifdef ASM_OUTPUT_WEAKREF
5440 ASM_OUTPUT_WEAKREF (asm_out_file, decl,
5441 IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl)),
5442 IDENTIFIER_POINTER (target));
5443 #else
5444 if (!SUPPORTS_WEAK)
5446 error_at (DECL_SOURCE_LOCATION (decl),
5447 "weakref is not supported in this configuration");
5448 return;
5450 #endif
5451 return;
5454 if (!targetm.have_tls
5455 && TREE_CODE (decl) == VAR_DECL
5456 && DECL_THREAD_LOCAL_P (decl))
5458 decl = emutls_decl (decl);
5459 target = get_emutls_object_name (target);
5462 #ifdef ASM_OUTPUT_DEF
5463 /* Make name accessible from other files, if appropriate. */
5465 if (TREE_PUBLIC (decl))
5467 globalize_decl (decl);
5468 maybe_assemble_visibility (decl);
5471 # ifdef ASM_OUTPUT_DEF_FROM_DECLS
5472 ASM_OUTPUT_DEF_FROM_DECLS (asm_out_file, decl, target);
5473 # else
5474 ASM_OUTPUT_DEF (asm_out_file,
5475 IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl)),
5476 IDENTIFIER_POINTER (target));
5477 # endif
5478 #elif defined (ASM_OUTPUT_WEAK_ALIAS) || defined (ASM_WEAKEN_DECL)
5480 const char *name;
5481 tree *p, t;
5483 name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
5484 # ifdef ASM_WEAKEN_DECL
5485 ASM_WEAKEN_DECL (asm_out_file, decl, name, IDENTIFIER_POINTER (target));
5486 # else
5487 ASM_OUTPUT_WEAK_ALIAS (asm_out_file, name, IDENTIFIER_POINTER (target));
5488 # endif
5489 /* Remove this function from the pending weak list so that
5490 we do not emit multiple .weak directives for it. */
5491 for (p = &weak_decls; (t = *p) ; )
5492 if (DECL_ASSEMBLER_NAME (decl) == DECL_ASSEMBLER_NAME (TREE_VALUE (t)))
5493 *p = TREE_CHAIN (t);
5494 else
5495 p = &TREE_CHAIN (t);
5497 /* Remove weakrefs to the same target from the pending weakref
5498 list, for the same reason. */
5499 for (p = &weakref_targets; (t = *p) ; )
5501 if (DECL_ASSEMBLER_NAME (decl)
5502 == ultimate_transparent_alias_target (&TREE_VALUE (t)))
5503 *p = TREE_CHAIN (t);
5504 else
5505 p = &TREE_CHAIN (t);
5508 #endif
5512 /* Remove the alias pairing for functions that are no longer in the call
5513 graph. */
5515 void
5516 remove_unreachable_alias_pairs (void)
5518 unsigned i;
5519 alias_pair *p;
5521 if (alias_pairs == NULL)
5522 return;
5524 for (i = 0; VEC_iterate (alias_pair, alias_pairs, i, p); )
5526 if (!DECL_EXTERNAL (p->decl))
5528 struct cgraph_node *fnode = NULL;
5529 struct varpool_node *vnode = NULL;
5530 fnode = cgraph_node_for_asm (p->target);
5531 vnode = (fnode == NULL) ? varpool_node_for_asm (p->target) : NULL;
5532 if (fnode == NULL && vnode == NULL)
5534 VEC_unordered_remove (alias_pair, alias_pairs, i);
5535 continue;
5539 i++;
5544 /* First pass of completing pending aliases. Make sure that cgraph knows
5545 which symbols will be required. */
5547 void
5548 finish_aliases_1 (void)
5550 unsigned i;
5551 alias_pair *p;
5553 for (i = 0; VEC_iterate (alias_pair, alias_pairs, i, p); i++)
5555 tree target_decl;
5557 target_decl = find_decl_and_mark_needed (p->decl, p->target);
5558 if (target_decl == NULL)
5560 if (! lookup_attribute ("weakref", DECL_ATTRIBUTES (p->decl)))
5561 error ("%q+D aliased to undefined symbol %qE",
5562 p->decl, p->target);
5564 else if (DECL_EXTERNAL (target_decl)
5565 /* We use local aliases for C++ thunks to force the tailcall
5566 to bind locally. Of course this is a hack - to keep it
5567 working do the following (which is not strictly correct). */
5568 && (! TREE_CODE (target_decl) == FUNCTION_DECL
5569 || ! DECL_VIRTUAL_P (target_decl))
5570 && ! lookup_attribute ("weakref", DECL_ATTRIBUTES (p->decl)))
5571 error ("%q+D aliased to external symbol %qE",
5572 p->decl, p->target);
5576 /* Second pass of completing pending aliases. Emit the actual assembly.
5577 This happens at the end of compilation and thus it is assured that the
5578 target symbol has been emitted. */
5580 void
5581 finish_aliases_2 (void)
5583 unsigned i;
5584 alias_pair *p;
5586 for (i = 0; VEC_iterate (alias_pair, alias_pairs, i, p); i++)
5587 do_assemble_alias (p->decl, p->target);
5589 VEC_truncate (alias_pair, alias_pairs, 0);
5592 /* Emit an assembler directive to make the symbol for DECL an alias to
5593 the symbol for TARGET. */
5595 void
5596 assemble_alias (tree decl, tree target)
5598 tree target_decl;
5599 bool is_weakref = false;
5601 if (lookup_attribute ("weakref", DECL_ATTRIBUTES (decl)))
5603 tree alias = DECL_ASSEMBLER_NAME (decl);
5605 is_weakref = true;
5607 ultimate_transparent_alias_target (&target);
5609 if (alias == target)
5610 error ("weakref %q+D ultimately targets itself", decl);
5611 else
5613 #ifndef ASM_OUTPUT_WEAKREF
5614 IDENTIFIER_TRANSPARENT_ALIAS (alias) = 1;
5615 TREE_CHAIN (alias) = target;
5616 #endif
5618 if (TREE_PUBLIC (decl))
5619 error ("weakref %q+D must have static linkage", decl);
5621 else
5623 #if !defined (ASM_OUTPUT_DEF)
5624 # if !defined(ASM_OUTPUT_WEAK_ALIAS) && !defined (ASM_WEAKEN_DECL)
5625 error_at (DECL_SOURCE_LOCATION (decl),
5626 "alias definitions not supported in this configuration");
5627 return;
5628 # else
5629 if (!DECL_WEAK (decl))
5631 error_at (DECL_SOURCE_LOCATION (decl),
5632 "only weak aliases are supported in this configuration");
5633 return;
5635 # endif
5636 #endif
5639 /* We must force creation of DECL_RTL for debug info generation, even though
5640 we don't use it here. */
5641 make_decl_rtl (decl);
5642 TREE_USED (decl) = 1;
5644 /* A quirk of the initial implementation of aliases required that the user
5645 add "extern" to all of them. Which is silly, but now historical. Do
5646 note that the symbol is in fact locally defined. */
5647 if (! is_weakref)
5648 DECL_EXTERNAL (decl) = 0;
5650 /* Allow aliases to aliases. */
5651 if (TREE_CODE (decl) == FUNCTION_DECL)
5652 cgraph_node (decl)->alias = true;
5653 else
5654 varpool_node (decl)->alias = true;
5656 /* If the target has already been emitted, we don't have to queue the
5657 alias. This saves a tad of memory. */
5658 if (cgraph_global_info_ready)
5659 target_decl = find_decl_and_mark_needed (decl, target);
5660 else
5661 target_decl= NULL;
5662 if (target_decl && TREE_ASM_WRITTEN (target_decl))
5663 do_assemble_alias (decl, target);
5664 else
5666 alias_pair *p = VEC_safe_push (alias_pair, gc, alias_pairs, NULL);
5667 p->decl = decl;
5668 p->target = target;
5672 /* Emit an assembler directive to set symbol for DECL visibility to
5673 the visibility type VIS, which must not be VISIBILITY_DEFAULT. */
5675 void
5676 default_assemble_visibility (tree decl, int vis)
5678 static const char * const visibility_types[] = {
5679 NULL, "protected", "hidden", "internal"
5682 const char *name, *type;
5684 name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
5685 type = visibility_types[vis];
5687 #ifdef HAVE_GAS_HIDDEN
5688 fprintf (asm_out_file, "\t.%s\t", type);
5689 assemble_name (asm_out_file, name);
5690 fprintf (asm_out_file, "\n");
5691 #else
5692 warning (OPT_Wattributes, "visibility attribute not supported "
5693 "in this configuration; ignored");
5694 #endif
5697 /* A helper function to call assemble_visibility when needed for a decl. */
5700 maybe_assemble_visibility (tree decl)
5702 enum symbol_visibility vis = DECL_VISIBILITY (decl);
5704 if (vis != VISIBILITY_DEFAULT)
5706 targetm.asm_out.visibility (decl, vis);
5707 return 1;
5709 else
5710 return 0;
5713 /* Returns 1 if the target configuration supports defining public symbols
5714 so that one of them will be chosen at link time instead of generating a
5715 multiply-defined symbol error, whether through the use of weak symbols or
5716 a target-specific mechanism for having duplicates discarded. */
5719 supports_one_only (void)
5721 if (SUPPORTS_ONE_ONLY)
5722 return 1;
5723 return SUPPORTS_WEAK;
5726 /* Set up DECL as a public symbol that can be defined in multiple
5727 translation units without generating a linker error. */
5729 void
5730 make_decl_one_only (tree decl, tree comdat_group)
5732 gcc_assert (TREE_CODE (decl) == VAR_DECL
5733 || TREE_CODE (decl) == FUNCTION_DECL);
5735 TREE_PUBLIC (decl) = 1;
5737 if (SUPPORTS_ONE_ONLY)
5739 #ifdef MAKE_DECL_ONE_ONLY
5740 MAKE_DECL_ONE_ONLY (decl);
5741 #endif
5742 DECL_COMDAT_GROUP (decl) = comdat_group;
5744 else if (TREE_CODE (decl) == VAR_DECL
5745 && (DECL_INITIAL (decl) == 0 || DECL_INITIAL (decl) == error_mark_node))
5746 DECL_COMMON (decl) = 1;
5747 else
5749 gcc_assert (SUPPORTS_WEAK);
5750 DECL_WEAK (decl) = 1;
5754 void
5755 init_varasm_once (void)
5757 section_htab = htab_create_ggc (31, section_entry_hash,
5758 section_entry_eq, NULL);
5759 object_block_htab = htab_create_ggc (31, object_block_entry_hash,
5760 object_block_entry_eq, NULL);
5761 const_desc_htab = htab_create_ggc (1009, const_desc_hash,
5762 const_desc_eq, NULL);
5764 const_alias_set = new_alias_set ();
5765 shared_constant_pool = create_constant_pool ();
5767 #ifdef TEXT_SECTION_ASM_OP
5768 text_section = get_unnamed_section (SECTION_CODE, output_section_asm_op,
5769 TEXT_SECTION_ASM_OP);
5770 #endif
5772 #ifdef DATA_SECTION_ASM_OP
5773 data_section = get_unnamed_section (SECTION_WRITE, output_section_asm_op,
5774 DATA_SECTION_ASM_OP);
5775 #endif
5777 #ifdef SDATA_SECTION_ASM_OP
5778 sdata_section = get_unnamed_section (SECTION_WRITE, output_section_asm_op,
5779 SDATA_SECTION_ASM_OP);
5780 #endif
5782 #ifdef READONLY_DATA_SECTION_ASM_OP
5783 readonly_data_section = get_unnamed_section (0, output_section_asm_op,
5784 READONLY_DATA_SECTION_ASM_OP);
5785 #endif
5787 #ifdef CTORS_SECTION_ASM_OP
5788 ctors_section = get_unnamed_section (0, output_section_asm_op,
5789 CTORS_SECTION_ASM_OP);
5790 #endif
5792 #ifdef DTORS_SECTION_ASM_OP
5793 dtors_section = get_unnamed_section (0, output_section_asm_op,
5794 DTORS_SECTION_ASM_OP);
5795 #endif
5797 #ifdef BSS_SECTION_ASM_OP
5798 bss_section = get_unnamed_section (SECTION_WRITE | SECTION_BSS,
5799 output_section_asm_op,
5800 BSS_SECTION_ASM_OP);
5801 #endif
5803 #ifdef SBSS_SECTION_ASM_OP
5804 sbss_section = get_unnamed_section (SECTION_WRITE | SECTION_BSS,
5805 output_section_asm_op,
5806 SBSS_SECTION_ASM_OP);
5807 #endif
5809 tls_comm_section = get_noswitch_section (SECTION_WRITE | SECTION_BSS
5810 | SECTION_COMMON, emit_tls_common);
5811 lcomm_section = get_noswitch_section (SECTION_WRITE | SECTION_BSS
5812 | SECTION_COMMON, emit_local);
5813 comm_section = get_noswitch_section (SECTION_WRITE | SECTION_BSS
5814 | SECTION_COMMON, emit_common);
5816 #if defined ASM_OUTPUT_ALIGNED_BSS || defined ASM_OUTPUT_BSS
5817 bss_noswitch_section = get_noswitch_section (SECTION_WRITE | SECTION_BSS,
5818 emit_bss);
5819 #endif
5821 targetm.asm_out.init_sections ();
5823 if (readonly_data_section == NULL)
5824 readonly_data_section = text_section;
5827 enum tls_model
5828 decl_default_tls_model (const_tree decl)
5830 enum tls_model kind;
5831 bool is_local;
5833 is_local = targetm.binds_local_p (decl);
5834 if (!flag_shlib)
5836 if (is_local)
5837 kind = TLS_MODEL_LOCAL_EXEC;
5838 else
5839 kind = TLS_MODEL_INITIAL_EXEC;
5842 /* Local dynamic is inefficient when we're not combining the
5843 parts of the address. */
5844 else if (optimize && is_local)
5845 kind = TLS_MODEL_LOCAL_DYNAMIC;
5846 else
5847 kind = TLS_MODEL_GLOBAL_DYNAMIC;
5848 if (kind < flag_tls_default)
5849 kind = flag_tls_default;
5851 return kind;
5854 /* Select a set of attributes for section NAME based on the properties
5855 of DECL and whether or not RELOC indicates that DECL's initializer
5856 might contain runtime relocations.
5858 We make the section read-only and executable for a function decl,
5859 read-only for a const data decl, and writable for a non-const data decl. */
5861 unsigned int
5862 default_section_type_flags (tree decl, const char *name, int reloc)
5864 unsigned int flags;
5866 if (decl && TREE_CODE (decl) == FUNCTION_DECL)
5867 flags = SECTION_CODE;
5868 else if (decl && decl_readonly_section (decl, reloc))
5869 flags = 0;
5870 else if (current_function_decl
5871 && cfun
5872 && crtl->subsections.unlikely_text_section_name
5873 && strcmp (name, crtl->subsections.unlikely_text_section_name) == 0)
5874 flags = SECTION_CODE;
5875 else if (!decl
5876 && (!current_function_decl || !cfun)
5877 && strcmp (name, UNLIKELY_EXECUTED_TEXT_SECTION_NAME) == 0)
5878 flags = SECTION_CODE;
5879 else
5880 flags = SECTION_WRITE;
5882 if (decl && DECL_ONE_ONLY (decl))
5883 flags |= SECTION_LINKONCE;
5885 if (decl && TREE_CODE (decl) == VAR_DECL && DECL_THREAD_LOCAL_P (decl))
5886 flags |= SECTION_TLS | SECTION_WRITE;
5888 if (strcmp (name, ".bss") == 0
5889 || strncmp (name, ".bss.", 5) == 0
5890 || strncmp (name, ".gnu.linkonce.b.", 16) == 0
5891 || strcmp (name, ".sbss") == 0
5892 || strncmp (name, ".sbss.", 6) == 0
5893 || strncmp (name, ".gnu.linkonce.sb.", 17) == 0)
5894 flags |= SECTION_BSS;
5896 if (strcmp (name, ".tdata") == 0
5897 || strncmp (name, ".tdata.", 7) == 0
5898 || strncmp (name, ".gnu.linkonce.td.", 17) == 0)
5899 flags |= SECTION_TLS;
5901 if (strcmp (name, ".tbss") == 0
5902 || strncmp (name, ".tbss.", 6) == 0
5903 || strncmp (name, ".gnu.linkonce.tb.", 17) == 0)
5904 flags |= SECTION_TLS | SECTION_BSS;
5906 /* These three sections have special ELF types. They are neither
5907 SHT_PROGBITS nor SHT_NOBITS, so when changing sections we don't
5908 want to print a section type (@progbits or @nobits). If someone
5909 is silly enough to emit code or TLS variables to one of these
5910 sections, then don't handle them specially. */
5911 if (!(flags & (SECTION_CODE | SECTION_BSS | SECTION_TLS))
5912 && (strcmp (name, ".init_array") == 0
5913 || strcmp (name, ".fini_array") == 0
5914 || strcmp (name, ".preinit_array") == 0))
5915 flags |= SECTION_NOTYPE;
5917 return flags;
5920 /* Return true if the target supports some form of global BSS,
5921 either through bss_noswitch_section, or by selecting a BSS
5922 section in TARGET_ASM_SELECT_SECTION. */
5924 bool
5925 have_global_bss_p (void)
5927 return bss_noswitch_section || targetm.have_switchable_bss_sections;
5930 /* Output assembly to switch to section NAME with attribute FLAGS.
5931 Four variants for common object file formats. */
5933 void
5934 default_no_named_section (const char *name ATTRIBUTE_UNUSED,
5935 unsigned int flags ATTRIBUTE_UNUSED,
5936 tree decl ATTRIBUTE_UNUSED)
5938 /* Some object formats don't support named sections at all. The
5939 front-end should already have flagged this as an error. */
5940 gcc_unreachable ();
5943 void
5944 default_elf_asm_named_section (const char *name, unsigned int flags,
5945 tree decl ATTRIBUTE_UNUSED)
5947 char flagchars[10], *f = flagchars;
5949 /* If we have already declared this section, we can use an
5950 abbreviated form to switch back to it -- unless this section is
5951 part of a COMDAT groups, in which case GAS requires the full
5952 declaration every time. */
5953 if (!(HAVE_COMDAT_GROUP && (flags & SECTION_LINKONCE))
5954 && (flags & SECTION_DECLARED))
5956 fprintf (asm_out_file, "\t.section\t%s\n", name);
5957 return;
5960 if (!(flags & SECTION_DEBUG))
5961 *f++ = 'a';
5962 if (flags & SECTION_WRITE)
5963 *f++ = 'w';
5964 if (flags & SECTION_CODE)
5965 *f++ = 'x';
5966 if (flags & SECTION_SMALL)
5967 *f++ = 's';
5968 if (flags & SECTION_MERGE)
5969 *f++ = 'M';
5970 if (flags & SECTION_STRINGS)
5971 *f++ = 'S';
5972 if (flags & SECTION_TLS)
5973 *f++ = 'T';
5974 if (HAVE_COMDAT_GROUP && (flags & SECTION_LINKONCE))
5975 *f++ = 'G';
5976 *f = '\0';
5978 fprintf (asm_out_file, "\t.section\t%s,\"%s\"", name, flagchars);
5980 if (!(flags & SECTION_NOTYPE))
5982 const char *type;
5983 const char *format;
5985 if (flags & SECTION_BSS)
5986 type = "nobits";
5987 else
5988 type = "progbits";
5990 format = ",@%s";
5991 #ifdef ASM_COMMENT_START
5992 /* On platforms that use "@" as the assembly comment character,
5993 use "%" instead. */
5994 if (strcmp (ASM_COMMENT_START, "@") == 0)
5995 format = ",%%%s";
5996 #endif
5997 fprintf (asm_out_file, format, type);
5999 if (flags & SECTION_ENTSIZE)
6000 fprintf (asm_out_file, ",%d", flags & SECTION_ENTSIZE);
6001 if (HAVE_COMDAT_GROUP && (flags & SECTION_LINKONCE))
6002 fprintf (asm_out_file, ",%s,comdat",
6003 IDENTIFIER_POINTER (DECL_COMDAT_GROUP (decl)));
6006 putc ('\n', asm_out_file);
6009 void
6010 default_coff_asm_named_section (const char *name, unsigned int flags,
6011 tree decl ATTRIBUTE_UNUSED)
6013 char flagchars[8], *f = flagchars;
6015 if (flags & SECTION_WRITE)
6016 *f++ = 'w';
6017 if (flags & SECTION_CODE)
6018 *f++ = 'x';
6019 *f = '\0';
6021 fprintf (asm_out_file, "\t.section\t%s,\"%s\"\n", name, flagchars);
6024 void
6025 default_pe_asm_named_section (const char *name, unsigned int flags,
6026 tree decl)
6028 default_coff_asm_named_section (name, flags, decl);
6030 if (flags & SECTION_LINKONCE)
6032 /* Functions may have been compiled at various levels of
6033 optimization so we can't use `same_size' here.
6034 Instead, have the linker pick one. */
6035 fprintf (asm_out_file, "\t.linkonce %s\n",
6036 (flags & SECTION_CODE ? "discard" : "same_size"));
6040 /* The lame default section selector. */
6042 section *
6043 default_select_section (tree decl, int reloc,
6044 unsigned HOST_WIDE_INT align ATTRIBUTE_UNUSED)
6046 if (DECL_P (decl))
6048 if (decl_readonly_section (decl, reloc))
6049 return readonly_data_section;
6051 else if (TREE_CODE (decl) == CONSTRUCTOR)
6053 if (! ((flag_pic && reloc)
6054 || !TREE_READONLY (decl)
6055 || TREE_SIDE_EFFECTS (decl)
6056 || !TREE_CONSTANT (decl)))
6057 return readonly_data_section;
6059 else if (TREE_CODE (decl) == STRING_CST)
6060 return readonly_data_section;
6061 else if (! (flag_pic && reloc))
6062 return readonly_data_section;
6064 return data_section;
6067 enum section_category
6068 categorize_decl_for_section (const_tree decl, int reloc)
6070 enum section_category ret;
6072 if (TREE_CODE (decl) == FUNCTION_DECL)
6073 return SECCAT_TEXT;
6074 else if (TREE_CODE (decl) == STRING_CST)
6076 if (flag_mudflap) /* or !flag_merge_constants */
6077 return SECCAT_RODATA;
6078 else
6079 return SECCAT_RODATA_MERGE_STR;
6081 else if (TREE_CODE (decl) == VAR_DECL)
6083 if (bss_initializer_p (decl))
6084 ret = SECCAT_BSS;
6085 else if (! TREE_READONLY (decl)
6086 || TREE_SIDE_EFFECTS (decl)
6087 || ! TREE_CONSTANT (DECL_INITIAL (decl)))
6089 /* Here the reloc_rw_mask is not testing whether the section should
6090 be read-only or not, but whether the dynamic link will have to
6091 do something. If so, we wish to segregate the data in order to
6092 minimize cache misses inside the dynamic linker. */
6093 if (reloc & targetm.asm_out.reloc_rw_mask ())
6094 ret = reloc == 1 ? SECCAT_DATA_REL_LOCAL : SECCAT_DATA_REL;
6095 else
6096 ret = SECCAT_DATA;
6098 else if (reloc & targetm.asm_out.reloc_rw_mask ())
6099 ret = reloc == 1 ? SECCAT_DATA_REL_RO_LOCAL : SECCAT_DATA_REL_RO;
6100 else if (reloc || flag_merge_constants < 2)
6101 /* C and C++ don't allow different variables to share the same
6102 location. -fmerge-all-constants allows even that (at the
6103 expense of not conforming). */
6104 ret = SECCAT_RODATA;
6105 else if (TREE_CODE (DECL_INITIAL (decl)) == STRING_CST)
6106 ret = SECCAT_RODATA_MERGE_STR_INIT;
6107 else
6108 ret = SECCAT_RODATA_MERGE_CONST;
6110 else if (TREE_CODE (decl) == CONSTRUCTOR)
6112 if ((reloc & targetm.asm_out.reloc_rw_mask ())
6113 || TREE_SIDE_EFFECTS (decl)
6114 || ! TREE_CONSTANT (decl))
6115 ret = SECCAT_DATA;
6116 else
6117 ret = SECCAT_RODATA;
6119 else
6120 ret = SECCAT_RODATA;
6122 /* There are no read-only thread-local sections. */
6123 if (TREE_CODE (decl) == VAR_DECL && DECL_TLS_MODEL (decl))
6125 if (DECL_TLS_MODEL (decl) == TLS_MODEL_EMULATED)
6127 if (DECL_EMUTLS_VAR_P (decl))
6129 if (targetm.emutls.var_section)
6130 ret = SECCAT_EMUTLS_VAR;
6132 else
6134 if (targetm.emutls.tmpl_prefix)
6135 ret = SECCAT_EMUTLS_TMPL;
6138 /* Note that this would be *just* SECCAT_BSS, except that there's
6139 no concept of a read-only thread-local-data section. */
6140 else if (ret == SECCAT_BSS
6141 || (flag_zero_initialized_in_bss
6142 && initializer_zerop (DECL_INITIAL (decl))))
6143 ret = SECCAT_TBSS;
6144 else
6145 ret = SECCAT_TDATA;
6148 /* If the target uses small data sections, select it. */
6149 else if (targetm.in_small_data_p (decl))
6151 if (ret == SECCAT_BSS)
6152 ret = SECCAT_SBSS;
6153 else if (targetm.have_srodata_section && ret == SECCAT_RODATA)
6154 ret = SECCAT_SRODATA;
6155 else
6156 ret = SECCAT_SDATA;
6159 return ret;
6162 bool
6163 decl_readonly_section (const_tree decl, int reloc)
6165 switch (categorize_decl_for_section (decl, reloc))
6167 case SECCAT_RODATA:
6168 case SECCAT_RODATA_MERGE_STR:
6169 case SECCAT_RODATA_MERGE_STR_INIT:
6170 case SECCAT_RODATA_MERGE_CONST:
6171 case SECCAT_SRODATA:
6172 return true;
6173 break;
6174 default:
6175 return false;
6176 break;
6180 /* Select a section based on the above categorization. */
6182 section *
6183 default_elf_select_section (tree decl, int reloc,
6184 unsigned HOST_WIDE_INT align)
6186 const char *sname;
6187 switch (categorize_decl_for_section (decl, reloc))
6189 case SECCAT_TEXT:
6190 /* We're not supposed to be called on FUNCTION_DECLs. */
6191 gcc_unreachable ();
6192 case SECCAT_RODATA:
6193 return readonly_data_section;
6194 case SECCAT_RODATA_MERGE_STR:
6195 return mergeable_string_section (decl, align, 0);
6196 case SECCAT_RODATA_MERGE_STR_INIT:
6197 return mergeable_string_section (DECL_INITIAL (decl), align, 0);
6198 case SECCAT_RODATA_MERGE_CONST:
6199 return mergeable_constant_section (DECL_MODE (decl), align, 0);
6200 case SECCAT_SRODATA:
6201 sname = ".sdata2";
6202 break;
6203 case SECCAT_DATA:
6204 return data_section;
6205 case SECCAT_DATA_REL:
6206 sname = ".data.rel";
6207 break;
6208 case SECCAT_DATA_REL_LOCAL:
6209 sname = ".data.rel.local";
6210 break;
6211 case SECCAT_DATA_REL_RO:
6212 sname = ".data.rel.ro";
6213 break;
6214 case SECCAT_DATA_REL_RO_LOCAL:
6215 sname = ".data.rel.ro.local";
6216 break;
6217 case SECCAT_SDATA:
6218 sname = ".sdata";
6219 break;
6220 case SECCAT_TDATA:
6221 sname = ".tdata";
6222 break;
6223 case SECCAT_BSS:
6224 if (bss_section)
6225 return bss_section;
6226 sname = ".bss";
6227 break;
6228 case SECCAT_SBSS:
6229 sname = ".sbss";
6230 break;
6231 case SECCAT_TBSS:
6232 sname = ".tbss";
6233 break;
6234 case SECCAT_EMUTLS_VAR:
6235 sname = targetm.emutls.var_section;
6236 break;
6237 case SECCAT_EMUTLS_TMPL:
6238 sname = targetm.emutls.tmpl_section;
6239 break;
6240 default:
6241 gcc_unreachable ();
6244 if (!DECL_P (decl))
6245 decl = NULL_TREE;
6246 return get_named_section (decl, sname, reloc);
6249 /* Construct a unique section name based on the decl name and the
6250 categorization performed above. */
6252 void
6253 default_unique_section (tree decl, int reloc)
6255 /* We only need to use .gnu.linkonce if we don't have COMDAT groups. */
6256 bool one_only = DECL_ONE_ONLY (decl) && !HAVE_COMDAT_GROUP;
6257 const char *prefix, *name, *linkonce;
6258 char *string;
6260 switch (categorize_decl_for_section (decl, reloc))
6262 case SECCAT_TEXT:
6263 prefix = one_only ? ".t" : ".text";
6264 break;
6265 case SECCAT_RODATA:
6266 case SECCAT_RODATA_MERGE_STR:
6267 case SECCAT_RODATA_MERGE_STR_INIT:
6268 case SECCAT_RODATA_MERGE_CONST:
6269 prefix = one_only ? ".r" : ".rodata";
6270 break;
6271 case SECCAT_SRODATA:
6272 prefix = one_only ? ".s2" : ".sdata2";
6273 break;
6274 case SECCAT_DATA:
6275 prefix = one_only ? ".d" : ".data";
6276 break;
6277 case SECCAT_DATA_REL:
6278 prefix = one_only ? ".d.rel" : ".data.rel";
6279 break;
6280 case SECCAT_DATA_REL_LOCAL:
6281 prefix = one_only ? ".d.rel.local" : ".data.rel.local";
6282 break;
6283 case SECCAT_DATA_REL_RO:
6284 prefix = one_only ? ".d.rel.ro" : ".data.rel.ro";
6285 break;
6286 case SECCAT_DATA_REL_RO_LOCAL:
6287 prefix = one_only ? ".d.rel.ro.local" : ".data.rel.ro.local";
6288 break;
6289 case SECCAT_SDATA:
6290 prefix = one_only ? ".s" : ".sdata";
6291 break;
6292 case SECCAT_BSS:
6293 prefix = one_only ? ".b" : ".bss";
6294 break;
6295 case SECCAT_SBSS:
6296 prefix = one_only ? ".sb" : ".sbss";
6297 break;
6298 case SECCAT_TDATA:
6299 prefix = one_only ? ".td" : ".tdata";
6300 break;
6301 case SECCAT_TBSS:
6302 prefix = one_only ? ".tb" : ".tbss";
6303 break;
6304 case SECCAT_EMUTLS_VAR:
6305 prefix = targetm.emutls.var_section;
6306 break;
6307 case SECCAT_EMUTLS_TMPL:
6308 prefix = targetm.emutls.tmpl_section;
6309 break;
6310 default:
6311 gcc_unreachable ();
6314 name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
6315 name = targetm.strip_name_encoding (name);
6317 /* If we're using one_only, then there needs to be a .gnu.linkonce
6318 prefix to the section name. */
6319 linkonce = one_only ? ".gnu.linkonce" : "";
6321 string = ACONCAT ((linkonce, prefix, ".", name, NULL));
6323 DECL_SECTION_NAME (decl) = build_string (strlen (string), string);
6326 /* Like compute_reloc_for_constant, except for an RTX. The return value
6327 is a mask for which bit 1 indicates a global relocation, and bit 0
6328 indicates a local relocation. */
6330 static int
6331 compute_reloc_for_rtx_1 (rtx *xp, void *data)
6333 int *preloc = (int *) data;
6334 rtx x = *xp;
6336 switch (GET_CODE (x))
6338 case SYMBOL_REF:
6339 *preloc |= SYMBOL_REF_LOCAL_P (x) ? 1 : 2;
6340 break;
6341 case LABEL_REF:
6342 *preloc |= 1;
6343 break;
6344 default:
6345 break;
6348 return 0;
6351 static int
6352 compute_reloc_for_rtx (rtx x)
6354 int reloc;
6356 switch (GET_CODE (x))
6358 case CONST:
6359 case SYMBOL_REF:
6360 case LABEL_REF:
6361 reloc = 0;
6362 for_each_rtx (&x, compute_reloc_for_rtx_1, &reloc);
6363 return reloc;
6365 default:
6366 return 0;
6370 section *
6371 default_select_rtx_section (enum machine_mode mode ATTRIBUTE_UNUSED,
6372 rtx x,
6373 unsigned HOST_WIDE_INT align ATTRIBUTE_UNUSED)
6375 if (compute_reloc_for_rtx (x) & targetm.asm_out.reloc_rw_mask ())
6376 return data_section;
6377 else
6378 return readonly_data_section;
6381 section *
6382 default_elf_select_rtx_section (enum machine_mode mode, rtx x,
6383 unsigned HOST_WIDE_INT align)
6385 int reloc = compute_reloc_for_rtx (x);
6387 /* ??? Handle small data here somehow. */
6389 if (reloc & targetm.asm_out.reloc_rw_mask ())
6391 if (reloc == 1)
6392 return get_named_section (NULL, ".data.rel.ro.local", 1);
6393 else
6394 return get_named_section (NULL, ".data.rel.ro", 3);
6397 return mergeable_constant_section (mode, align, 0);
6400 /* Set the generally applicable flags on the SYMBOL_REF for EXP. */
6402 void
6403 default_encode_section_info (tree decl, rtx rtl, int first ATTRIBUTE_UNUSED)
6405 rtx symbol;
6406 int flags;
6408 /* Careful not to prod global register variables. */
6409 if (!MEM_P (rtl))
6410 return;
6411 symbol = XEXP (rtl, 0);
6412 if (GET_CODE (symbol) != SYMBOL_REF)
6413 return;
6415 flags = SYMBOL_REF_FLAGS (symbol) & SYMBOL_FLAG_HAS_BLOCK_INFO;
6416 if (TREE_CODE (decl) == FUNCTION_DECL)
6417 flags |= SYMBOL_FLAG_FUNCTION;
6418 if (targetm.binds_local_p (decl))
6419 flags |= SYMBOL_FLAG_LOCAL;
6420 if (TREE_CODE (decl) == VAR_DECL && DECL_THREAD_LOCAL_P (decl)
6421 && DECL_TLS_MODEL (decl) != TLS_MODEL_EMULATED)
6422 flags |= DECL_TLS_MODEL (decl) << SYMBOL_FLAG_TLS_SHIFT;
6423 else if (targetm.in_small_data_p (decl))
6424 flags |= SYMBOL_FLAG_SMALL;
6425 /* ??? Why is DECL_EXTERNAL ever set for non-PUBLIC names? Without
6426 being PUBLIC, the thing *must* be defined in this translation unit.
6427 Prevent this buglet from being propagated into rtl code as well. */
6428 if (DECL_P (decl) && DECL_EXTERNAL (decl) && TREE_PUBLIC (decl))
6429 flags |= SYMBOL_FLAG_EXTERNAL;
6431 SYMBOL_REF_FLAGS (symbol) = flags;
6434 /* By default, we do nothing for encode_section_info, so we need not
6435 do anything but discard the '*' marker. */
6437 const char *
6438 default_strip_name_encoding (const char *str)
6440 return str + (*str == '*');
6443 #ifdef ASM_OUTPUT_DEF
6444 /* The default implementation of TARGET_ASM_OUTPUT_ANCHOR. Define the
6445 anchor relative to ".", the current section position. */
6447 void
6448 default_asm_output_anchor (rtx symbol)
6450 char buffer[100];
6452 sprintf (buffer, "*. + " HOST_WIDE_INT_PRINT_DEC,
6453 SYMBOL_REF_BLOCK_OFFSET (symbol));
6454 ASM_OUTPUT_DEF (asm_out_file, XSTR (symbol, 0), buffer);
6456 #endif
6458 /* The default implementation of TARGET_USE_ANCHORS_FOR_SYMBOL_P. */
6460 bool
6461 default_use_anchors_for_symbol_p (const_rtx symbol)
6463 section *sect;
6464 tree decl;
6466 /* Don't use anchors for mergeable sections. The linker might move
6467 the objects around. */
6468 sect = SYMBOL_REF_BLOCK (symbol)->sect;
6469 if (sect->common.flags & SECTION_MERGE)
6470 return false;
6472 /* Don't use anchors for small data sections. The small data register
6473 acts as an anchor for such sections. */
6474 if (sect->common.flags & SECTION_SMALL)
6475 return false;
6477 decl = SYMBOL_REF_DECL (symbol);
6478 if (decl && DECL_P (decl))
6480 /* Don't use section anchors for decls that might be defined by
6481 other modules. */
6482 if (!targetm.binds_local_p (decl))
6483 return false;
6485 /* Don't use section anchors for decls that will be placed in a
6486 small data section. */
6487 /* ??? Ideally, this check would be redundant with the SECTION_SMALL
6488 one above. The problem is that we only use SECTION_SMALL for
6489 sections that should be marked as small in the section directive. */
6490 if (targetm.in_small_data_p (decl))
6491 return false;
6493 return true;
6496 /* Assume ELF-ish defaults, since that's pretty much the most liberal
6497 wrt cross-module name binding. */
6499 bool
6500 default_binds_local_p (const_tree exp)
6502 return default_binds_local_p_1 (exp, flag_shlib);
6505 bool
6506 default_binds_local_p_1 (const_tree exp, int shlib)
6508 bool local_p;
6510 /* A non-decl is an entry in the constant pool. */
6511 if (!DECL_P (exp))
6512 local_p = true;
6513 /* Weakrefs may not bind locally, even though the weakref itself is
6514 always static and therefore local. */
6515 else if (lookup_attribute ("weakref", DECL_ATTRIBUTES (exp)))
6516 local_p = false;
6517 /* Static variables are always local. */
6518 else if (! TREE_PUBLIC (exp))
6519 local_p = true;
6520 /* A variable is local if the user has said explicitly that it will
6521 be. */
6522 else if (DECL_VISIBILITY_SPECIFIED (exp)
6523 && DECL_VISIBILITY (exp) != VISIBILITY_DEFAULT)
6524 local_p = true;
6525 /* Variables defined outside this object might not be local. */
6526 else if (DECL_EXTERNAL (exp))
6527 local_p = false;
6528 /* If defined in this object and visibility is not default, must be
6529 local. */
6530 else if (DECL_VISIBILITY (exp) != VISIBILITY_DEFAULT)
6531 local_p = true;
6532 /* Default visibility weak data can be overridden by a strong symbol
6533 in another module and so are not local. */
6534 else if (DECL_WEAK (exp))
6535 local_p = false;
6536 /* If PIC, then assume that any global name can be overridden by
6537 symbols resolved from other modules, unless we are compiling with
6538 -fwhole-program, which assumes that names are local. */
6539 else if (shlib)
6540 local_p = flag_whole_program;
6541 /* Uninitialized COMMON variable may be unified with symbols
6542 resolved from other modules. */
6543 else if (DECL_COMMON (exp)
6544 && (DECL_INITIAL (exp) == NULL
6545 || DECL_INITIAL (exp) == error_mark_node))
6546 local_p = false;
6547 /* Otherwise we're left with initialized (or non-common) global data
6548 which is of necessity defined locally. */
6549 else
6550 local_p = true;
6552 return local_p;
6555 /* Determine whether or not a pointer mode is valid. Assume defaults
6556 of ptr_mode or Pmode - can be overridden. */
6557 bool
6558 default_valid_pointer_mode (enum machine_mode mode)
6560 return (mode == ptr_mode || mode == Pmode);
6563 /* Default function to output code that will globalize a label. A
6564 target must define GLOBAL_ASM_OP or provide its own function to
6565 globalize a label. */
6566 #ifdef GLOBAL_ASM_OP
6567 void
6568 default_globalize_label (FILE * stream, const char *name)
6570 fputs (GLOBAL_ASM_OP, stream);
6571 assemble_name (stream, name);
6572 putc ('\n', stream);
6574 #endif /* GLOBAL_ASM_OP */
6576 /* Default function to output code that will globalize a declaration. */
6577 void
6578 default_globalize_decl_name (FILE * stream, tree decl)
6580 const char *name = XSTR (XEXP (DECL_RTL (decl), 0), 0);
6581 targetm.asm_out.globalize_label (stream, name);
6584 /* Default function to output a label for unwind information. The
6585 default is to do nothing. A target that needs nonlocal labels for
6586 unwind information must provide its own function to do this. */
6587 void
6588 default_emit_unwind_label (FILE * stream ATTRIBUTE_UNUSED,
6589 tree decl ATTRIBUTE_UNUSED,
6590 int for_eh ATTRIBUTE_UNUSED,
6591 int empty ATTRIBUTE_UNUSED)
6595 /* Default function to output a label to divide up the exception table.
6596 The default is to do nothing. A target that needs/wants to divide
6597 up the table must provide it's own function to do this. */
6598 void
6599 default_emit_except_table_label (FILE * stream ATTRIBUTE_UNUSED)
6603 /* This is how to output an internal numbered label where PREFIX is
6604 the class of label and LABELNO is the number within the class. */
6606 void
6607 default_internal_label (FILE *stream, const char *prefix,
6608 unsigned long labelno)
6610 char *const buf = (char *) alloca (40 + strlen (prefix));
6611 ASM_GENERATE_INTERNAL_LABEL (buf, prefix, labelno);
6612 ASM_OUTPUT_INTERNAL_LABEL (stream, buf);
6615 /* This is the default behavior at the beginning of a file. It's
6616 controlled by two other target-hook toggles. */
6617 void
6618 default_file_start (void)
6620 if (targetm.file_start_app_off
6621 && !(flag_verbose_asm || flag_debug_asm || flag_dump_rtl_in_asm))
6622 fputs (ASM_APP_OFF, asm_out_file);
6624 if (targetm.file_start_file_directive)
6625 output_file_directive (asm_out_file, main_input_filename);
6628 /* This is a generic routine suitable for use as TARGET_ASM_FILE_END
6629 which emits a special section directive used to indicate whether or
6630 not this object file needs an executable stack. This is primarily
6631 a GNU extension to ELF but could be used on other targets. */
6633 int trampolines_created;
6635 void
6636 file_end_indicate_exec_stack (void)
6638 unsigned int flags = SECTION_DEBUG;
6639 if (trampolines_created)
6640 flags |= SECTION_CODE;
6642 switch_to_section (get_section (".note.GNU-stack", flags, NULL));
6645 /* Output DIRECTIVE (a C string) followed by a newline. This is used as
6646 a get_unnamed_section callback. */
6648 void
6649 output_section_asm_op (const void *directive)
6651 fprintf (asm_out_file, "%s\n", (const char *) directive);
6654 /* Emit assembly code to switch to section NEW_SECTION. Do nothing if
6655 the current section is NEW_SECTION. */
6657 void
6658 switch_to_section (section *new_section)
6660 if (in_section == new_section)
6661 return;
6663 if (new_section->common.flags & SECTION_FORGET)
6664 in_section = NULL;
6665 else
6666 in_section = new_section;
6668 switch (SECTION_STYLE (new_section))
6670 case SECTION_NAMED:
6671 if (cfun
6672 && !crtl->subsections.unlikely_text_section_name
6673 && strcmp (new_section->named.name,
6674 UNLIKELY_EXECUTED_TEXT_SECTION_NAME) == 0)
6675 crtl->subsections.unlikely_text_section_name = UNLIKELY_EXECUTED_TEXT_SECTION_NAME;
6677 targetm.asm_out.named_section (new_section->named.name,
6678 new_section->named.common.flags,
6679 new_section->named.decl);
6680 break;
6682 case SECTION_UNNAMED:
6683 new_section->unnamed.callback (new_section->unnamed.data);
6684 break;
6686 case SECTION_NOSWITCH:
6687 gcc_unreachable ();
6688 break;
6691 new_section->common.flags |= SECTION_DECLARED;
6694 /* If block symbol SYMBOL has not yet been assigned an offset, place
6695 it at the end of its block. */
6697 void
6698 place_block_symbol (rtx symbol)
6700 unsigned HOST_WIDE_INT size, mask, offset;
6701 struct constant_descriptor_rtx *desc;
6702 unsigned int alignment;
6703 struct object_block *block;
6704 tree decl;
6706 gcc_assert (SYMBOL_REF_BLOCK (symbol));
6707 if (SYMBOL_REF_BLOCK_OFFSET (symbol) >= 0)
6708 return;
6710 /* Work out the symbol's size and alignment. */
6711 if (CONSTANT_POOL_ADDRESS_P (symbol))
6713 desc = SYMBOL_REF_CONSTANT (symbol);
6714 alignment = desc->align;
6715 size = GET_MODE_SIZE (desc->mode);
6717 else if (TREE_CONSTANT_POOL_ADDRESS_P (symbol))
6719 decl = SYMBOL_REF_DECL (symbol);
6720 alignment = get_constant_alignment (decl);
6721 size = get_constant_size (decl);
6723 else
6725 decl = SYMBOL_REF_DECL (symbol);
6726 alignment = DECL_ALIGN (decl);
6727 size = tree_low_cst (DECL_SIZE_UNIT (decl), 1);
6730 /* Calculate the object's offset from the start of the block. */
6731 block = SYMBOL_REF_BLOCK (symbol);
6732 mask = alignment / BITS_PER_UNIT - 1;
6733 offset = (block->size + mask) & ~mask;
6734 SYMBOL_REF_BLOCK_OFFSET (symbol) = offset;
6736 /* Record the block's new alignment and size. */
6737 block->alignment = MAX (block->alignment, alignment);
6738 block->size = offset + size;
6740 VEC_safe_push (rtx, gc, block->objects, symbol);
6743 /* Return the anchor that should be used to address byte offset OFFSET
6744 from the first object in BLOCK. MODEL is the TLS model used
6745 to access it. */
6748 get_section_anchor (struct object_block *block, HOST_WIDE_INT offset,
6749 enum tls_model model)
6751 char label[100];
6752 unsigned int begin, middle, end;
6753 unsigned HOST_WIDE_INT min_offset, max_offset, range, bias, delta;
6754 rtx anchor;
6756 /* Work out the anchor's offset. Use an offset of 0 for the first
6757 anchor so that we don't pessimize the case where we take the address
6758 of a variable at the beginning of the block. This is particularly
6759 useful when a block has only one variable assigned to it.
6761 We try to place anchors RANGE bytes apart, so there can then be
6762 anchors at +/-RANGE, +/-2 * RANGE, and so on, up to the limits of
6763 a ptr_mode offset. With some target settings, the lowest such
6764 anchor might be out of range for the lowest ptr_mode offset;
6765 likewise the highest anchor for the highest offset. Use anchors
6766 at the extreme ends of the ptr_mode range in such cases.
6768 All arithmetic uses unsigned integers in order to avoid
6769 signed overflow. */
6770 max_offset = (unsigned HOST_WIDE_INT) targetm.max_anchor_offset;
6771 min_offset = (unsigned HOST_WIDE_INT) targetm.min_anchor_offset;
6772 range = max_offset - min_offset + 1;
6773 if (range == 0)
6774 offset = 0;
6775 else
6777 bias = 1 << (GET_MODE_BITSIZE (ptr_mode) - 1);
6778 if (offset < 0)
6780 delta = -(unsigned HOST_WIDE_INT) offset + max_offset;
6781 delta -= delta % range;
6782 if (delta > bias)
6783 delta = bias;
6784 offset = (HOST_WIDE_INT) (-delta);
6786 else
6788 delta = (unsigned HOST_WIDE_INT) offset - min_offset;
6789 delta -= delta % range;
6790 if (delta > bias - 1)
6791 delta = bias - 1;
6792 offset = (HOST_WIDE_INT) delta;
6796 /* Do a binary search to see if there's already an anchor we can use.
6797 Set BEGIN to the new anchor's index if not. */
6798 begin = 0;
6799 end = VEC_length (rtx, block->anchors);
6800 while (begin != end)
6802 middle = (end + begin) / 2;
6803 anchor = VEC_index (rtx, block->anchors, middle);
6804 if (SYMBOL_REF_BLOCK_OFFSET (anchor) > offset)
6805 end = middle;
6806 else if (SYMBOL_REF_BLOCK_OFFSET (anchor) < offset)
6807 begin = middle + 1;
6808 else if (SYMBOL_REF_TLS_MODEL (anchor) > model)
6809 end = middle;
6810 else if (SYMBOL_REF_TLS_MODEL (anchor) < model)
6811 begin = middle + 1;
6812 else
6813 return anchor;
6816 /* Create a new anchor with a unique label. */
6817 ASM_GENERATE_INTERNAL_LABEL (label, "LANCHOR", anchor_labelno++);
6818 anchor = create_block_symbol (ggc_strdup (label), block, offset);
6819 SYMBOL_REF_FLAGS (anchor) |= SYMBOL_FLAG_LOCAL | SYMBOL_FLAG_ANCHOR;
6820 SYMBOL_REF_FLAGS (anchor) |= model << SYMBOL_FLAG_TLS_SHIFT;
6822 /* Insert it at index BEGIN. */
6823 VEC_safe_insert (rtx, gc, block->anchors, begin, anchor);
6824 return anchor;
6827 /* Output the objects in BLOCK. */
6829 static void
6830 output_object_block (struct object_block *block)
6832 struct constant_descriptor_rtx *desc;
6833 unsigned int i;
6834 HOST_WIDE_INT offset;
6835 tree decl;
6836 rtx symbol;
6838 if (block->objects == NULL)
6839 return;
6841 /* Switch to the section and make sure that the first byte is
6842 suitably aligned. */
6843 switch_to_section (block->sect);
6844 assemble_align (block->alignment);
6846 /* Define the values of all anchors relative to the current section
6847 position. */
6848 for (i = 0; VEC_iterate (rtx, block->anchors, i, symbol); i++)
6849 targetm.asm_out.output_anchor (symbol);
6851 /* Output the objects themselves. */
6852 offset = 0;
6853 for (i = 0; VEC_iterate (rtx, block->objects, i, symbol); i++)
6855 /* Move to the object's offset, padding with zeros if necessary. */
6856 assemble_zeros (SYMBOL_REF_BLOCK_OFFSET (symbol) - offset);
6857 offset = SYMBOL_REF_BLOCK_OFFSET (symbol);
6858 if (CONSTANT_POOL_ADDRESS_P (symbol))
6860 desc = SYMBOL_REF_CONSTANT (symbol);
6861 output_constant_pool_1 (desc, 1);
6862 offset += GET_MODE_SIZE (desc->mode);
6864 else if (TREE_CONSTANT_POOL_ADDRESS_P (symbol))
6866 decl = SYMBOL_REF_DECL (symbol);
6867 assemble_constant_contents (decl, XSTR (symbol, 0),
6868 get_constant_alignment (decl));
6869 offset += get_constant_size (decl);
6871 else
6873 decl = SYMBOL_REF_DECL (symbol);
6874 assemble_variable_contents (decl, XSTR (symbol, 0), false);
6875 offset += tree_low_cst (DECL_SIZE_UNIT (decl), 1);
6880 /* A htab_traverse callback used to call output_object_block for
6881 each member of object_block_htab. */
6883 static int
6884 output_object_block_htab (void **slot, void *data ATTRIBUTE_UNUSED)
6886 output_object_block ((struct object_block *) (*slot));
6887 return 1;
6890 /* Output the definitions of all object_blocks. */
6892 void
6893 output_object_blocks (void)
6895 htab_traverse (object_block_htab, output_object_block_htab, NULL);
6898 /* This function provides a possible implementation of the
6899 TARGET_ASM_RECORD_GCC_SWITCHES target hook for ELF targets. When triggered
6900 by -frecord-gcc-switches it creates a new mergeable, string section in the
6901 assembler output file called TARGET_ASM_RECORD_GCC_SWITCHES_SECTION which
6902 contains the switches in ASCII format.
6904 FIXME: This code does not correctly handle double quote characters
6905 that appear inside strings, (it strips them rather than preserving them).
6906 FIXME: ASM_OUTPUT_ASCII, as defined in config/elfos.h will not emit NUL
6907 characters - instead it treats them as sub-string separators. Since
6908 we want to emit NUL strings terminators into the object file we have to use
6909 ASM_OUTPUT_SKIP. */
6912 elf_record_gcc_switches (print_switch_type type, const char * name)
6914 static char buffer[1024];
6916 /* This variable is used as part of a simplistic heuristic to detect
6917 command line switches which take an argument:
6919 "If a command line option does not start with a dash then
6920 it is an argument for the previous command line option."
6922 This fails in the case of the command line option which is the name
6923 of the file to compile, but otherwise it is pretty reasonable. */
6924 static bool previous_name_held_back = FALSE;
6926 switch (type)
6928 case SWITCH_TYPE_PASSED:
6929 if (* name != '-')
6931 if (previous_name_held_back)
6933 unsigned int len = strlen (buffer);
6935 snprintf (buffer + len, sizeof buffer - len, " %s", name);
6936 ASM_OUTPUT_ASCII (asm_out_file, buffer, strlen (buffer));
6937 ASM_OUTPUT_SKIP (asm_out_file, (unsigned HOST_WIDE_INT) 1);
6938 previous_name_held_back = FALSE;
6940 else
6942 strncpy (buffer, name, sizeof buffer);
6943 ASM_OUTPUT_ASCII (asm_out_file, buffer, strlen (buffer));
6944 ASM_OUTPUT_SKIP (asm_out_file, (unsigned HOST_WIDE_INT) 1);
6947 else
6949 if (previous_name_held_back)
6951 ASM_OUTPUT_ASCII (asm_out_file, buffer, strlen (buffer));
6952 ASM_OUTPUT_SKIP (asm_out_file, (unsigned HOST_WIDE_INT) 1);
6955 strncpy (buffer, name, sizeof buffer);
6956 previous_name_held_back = TRUE;
6958 break;
6960 case SWITCH_TYPE_DESCRIPTIVE:
6961 if (name == NULL)
6963 /* Distinguish between invocations where name is NULL. */
6964 static bool started = false;
6966 if (started)
6968 if (previous_name_held_back)
6970 ASM_OUTPUT_ASCII (asm_out_file, buffer, strlen (buffer));
6971 ASM_OUTPUT_SKIP (asm_out_file, (unsigned HOST_WIDE_INT) 1);
6974 else
6976 section * sec;
6978 sec = get_section (targetm.asm_out.record_gcc_switches_section,
6979 SECTION_DEBUG
6980 | SECTION_MERGE
6981 | SECTION_STRINGS
6982 | (SECTION_ENTSIZE & 1),
6983 NULL);
6984 switch_to_section (sec);
6985 started = true;
6989 default:
6990 break;
6993 /* The return value is currently ignored by the caller, but must be 0.
6994 For -fverbose-asm the return value would be the number of characters
6995 emitted into the assembler file. */
6996 return 0;
6999 /* Emit text to declare externally defined symbols. It is needed to
7000 properly support non-default visibility. */
7001 void
7002 default_elf_asm_output_external (FILE *file ATTRIBUTE_UNUSED,
7003 tree decl,
7004 const char *name ATTRIBUTE_UNUSED)
7006 /* We output the name if and only if TREE_SYMBOL_REFERENCED is
7007 set in order to avoid putting out names that are never really
7008 used. */
7009 if (TREE_SYMBOL_REFERENCED (DECL_ASSEMBLER_NAME (decl))
7010 && targetm.binds_local_p (decl))
7011 maybe_assemble_visibility (decl);
7014 #include "gt-varasm.h"