* varasm.c (const_rtx_hash_1): Remove const qualifier from shift.
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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 (x, args);
450 append_to_statement_list (x, pstmts);
451 return 1;
454 void
455 emutls_finish (void)
457 if (targetm.emutls.register_common)
459 tree body = NULL_TREE;
461 if (emutls_htab == NULL)
462 return;
464 htab_traverse_noresize (emutls_htab, emutls_common_1, &body);
465 if (body == NULL_TREE)
466 return;
468 cgraph_build_static_cdtor ('I', body, DEFAULT_INIT_PRIORITY);
472 /* Helper routines for maintaining section_htab. */
474 static int
475 section_entry_eq (const void *p1, const void *p2)
477 const section *old = (const section *) p1;
478 const char *new_name = (const char *) p2;
480 return strcmp (old->named.name, new_name) == 0;
483 static hashval_t
484 section_entry_hash (const void *p)
486 const section *old = (const section *) p;
487 return htab_hash_string (old->named.name);
490 /* Return a hash value for section SECT. */
492 static hashval_t
493 hash_section (section *sect)
495 if (sect->common.flags & SECTION_NAMED)
496 return htab_hash_string (sect->named.name);
497 return sect->common.flags;
500 /* Helper routines for maintaining object_block_htab. */
502 static int
503 object_block_entry_eq (const void *p1, const void *p2)
505 const struct object_block *old = (const struct object_block *) p1;
506 const section *new_section = (const section *) p2;
508 return old->sect == new_section;
511 static hashval_t
512 object_block_entry_hash (const void *p)
514 const struct object_block *old = (const struct object_block *) p;
515 return hash_section (old->sect);
518 /* Return a new unnamed section with the given fields. */
520 section *
521 get_unnamed_section (unsigned int flags, void (*callback) (const void *),
522 const void *data)
524 section *sect;
526 sect = GGC_NEW (section);
527 sect->unnamed.common.flags = flags | SECTION_UNNAMED;
528 sect->unnamed.callback = callback;
529 sect->unnamed.data = data;
530 sect->unnamed.next = unnamed_sections;
532 unnamed_sections = sect;
533 return sect;
536 /* Return a SECTION_NOSWITCH section with the given fields. */
538 static section *
539 get_noswitch_section (unsigned int flags, noswitch_section_callback callback)
541 section *sect;
543 sect = GGC_NEW (section);
544 sect->noswitch.common.flags = flags | SECTION_NOSWITCH;
545 sect->noswitch.callback = callback;
547 return sect;
550 /* Return the named section structure associated with NAME. Create
551 a new section with the given fields if no such structure exists. */
553 section *
554 get_section (const char *name, unsigned int flags, tree decl)
556 section *sect, **slot;
558 slot = (section **)
559 htab_find_slot_with_hash (section_htab, name,
560 htab_hash_string (name), INSERT);
561 flags |= SECTION_NAMED;
562 if (*slot == NULL)
564 sect = GGC_NEW (section);
565 sect->named.common.flags = flags;
566 sect->named.name = ggc_strdup (name);
567 sect->named.decl = decl;
568 *slot = sect;
570 else
572 sect = *slot;
573 if ((sect->common.flags & ~SECTION_DECLARED) != flags
574 && ((sect->common.flags | flags) & SECTION_OVERRIDE) == 0)
576 /* Sanity check user variables for flag changes. */
577 if (decl == 0)
578 decl = sect->named.decl;
579 gcc_assert (decl);
580 error ("%+D causes a section type conflict", decl);
583 return sect;
586 /* Return true if the current compilation mode benefits from having
587 objects grouped into blocks. */
589 static bool
590 use_object_blocks_p (void)
592 return flag_section_anchors;
595 /* Return the object_block structure for section SECT. Create a new
596 structure if we haven't created one already. Return null if SECT
597 itself is null. */
599 static struct object_block *
600 get_block_for_section (section *sect)
602 struct object_block *block;
603 void **slot;
605 if (sect == NULL)
606 return NULL;
608 slot = htab_find_slot_with_hash (object_block_htab, sect,
609 hash_section (sect), INSERT);
610 block = (struct object_block *) *slot;
611 if (block == NULL)
613 block = (struct object_block *)
614 ggc_alloc_cleared (sizeof (struct object_block));
615 block->sect = sect;
616 *slot = block;
618 return block;
621 /* Create a symbol with label LABEL and place it at byte offset
622 OFFSET in BLOCK. OFFSET can be negative if the symbol's offset
623 is not yet known. LABEL must be a garbage-collected string. */
625 static rtx
626 create_block_symbol (const char *label, struct object_block *block,
627 HOST_WIDE_INT offset)
629 rtx symbol;
630 unsigned int size;
632 /* Create the extended SYMBOL_REF. */
633 size = RTX_HDR_SIZE + sizeof (struct block_symbol);
634 symbol = (rtx) ggc_alloc_zone (size, &rtl_zone);
636 /* Initialize the normal SYMBOL_REF fields. */
637 memset (symbol, 0, size);
638 PUT_CODE (symbol, SYMBOL_REF);
639 PUT_MODE (symbol, Pmode);
640 XSTR (symbol, 0) = label;
641 SYMBOL_REF_FLAGS (symbol) = SYMBOL_FLAG_HAS_BLOCK_INFO;
643 /* Initialize the block_symbol stuff. */
644 SYMBOL_REF_BLOCK (symbol) = block;
645 SYMBOL_REF_BLOCK_OFFSET (symbol) = offset;
647 return symbol;
650 static void
651 initialize_cold_section_name (void)
653 const char *stripped_name;
654 char *name, *buffer;
655 tree dsn;
657 gcc_assert (cfun && current_function_decl);
658 if (crtl->subsections.unlikely_text_section_name)
659 return;
661 dsn = DECL_SECTION_NAME (current_function_decl);
662 if (flag_function_sections && dsn)
664 name = (char *) alloca (TREE_STRING_LENGTH (dsn) + 1);
665 memcpy (name, TREE_STRING_POINTER (dsn), TREE_STRING_LENGTH (dsn) + 1);
667 stripped_name = targetm.strip_name_encoding (name);
669 buffer = ACONCAT ((stripped_name, "_unlikely", NULL));
670 crtl->subsections.unlikely_text_section_name = ggc_strdup (buffer);
672 else
673 crtl->subsections.unlikely_text_section_name = UNLIKELY_EXECUTED_TEXT_SECTION_NAME;
676 /* Tell assembler to switch to unlikely-to-be-executed text section. */
678 section *
679 unlikely_text_section (void)
681 if (cfun)
683 if (!crtl->subsections.unlikely_text_section_name)
684 initialize_cold_section_name ();
686 return get_named_section (NULL, crtl->subsections.unlikely_text_section_name, 0);
688 else
689 return get_named_section (NULL, UNLIKELY_EXECUTED_TEXT_SECTION_NAME, 0);
692 /* When called within a function context, return true if the function
693 has been assigned a cold text section and if SECT is that section.
694 When called outside a function context, return true if SECT is the
695 default cold section. */
697 bool
698 unlikely_text_section_p (section *sect)
700 const char *name;
702 if (cfun)
703 name = crtl->subsections.unlikely_text_section_name;
704 else
705 name = UNLIKELY_EXECUTED_TEXT_SECTION_NAME;
707 return (name
708 && sect
709 && SECTION_STYLE (sect) == SECTION_NAMED
710 && strcmp (name, sect->named.name) == 0);
713 /* Return a section with a particular name and with whatever SECTION_*
714 flags section_type_flags deems appropriate. The name of the section
715 is taken from NAME if nonnull, otherwise it is taken from DECL's
716 DECL_SECTION_NAME. DECL is the decl associated with the section
717 (see the section comment for details) and RELOC is as for
718 section_type_flags. */
720 section *
721 get_named_section (tree decl, const char *name, int reloc)
723 unsigned int flags;
725 gcc_assert (!decl || DECL_P (decl));
726 if (name == NULL)
727 name = TREE_STRING_POINTER (DECL_SECTION_NAME (decl));
729 flags = targetm.section_type_flags (decl, name, reloc);
731 return get_section (name, flags, decl);
734 /* If required, set DECL_SECTION_NAME to a unique name. */
736 void
737 resolve_unique_section (tree decl, int reloc ATTRIBUTE_UNUSED,
738 int flag_function_or_data_sections)
740 if (DECL_SECTION_NAME (decl) == NULL_TREE
741 && targetm.have_named_sections
742 && (flag_function_or_data_sections
743 || DECL_ONE_ONLY (decl)))
744 targetm.asm_out.unique_section (decl, reloc);
747 #ifdef BSS_SECTION_ASM_OP
749 #ifdef ASM_OUTPUT_BSS
751 /* Utility function for ASM_OUTPUT_BSS for targets to use if
752 they don't support alignments in .bss.
753 ??? It is believed that this function will work in most cases so such
754 support is localized here. */
756 static void
757 asm_output_bss (FILE *file, tree decl ATTRIBUTE_UNUSED,
758 const char *name,
759 unsigned HOST_WIDE_INT size ATTRIBUTE_UNUSED,
760 unsigned HOST_WIDE_INT rounded)
762 gcc_assert (strcmp (XSTR (XEXP (DECL_RTL (decl), 0), 0), name) == 0);
763 targetm.asm_out.globalize_decl_name (file, decl);
764 switch_to_section (bss_section);
765 #ifdef ASM_DECLARE_OBJECT_NAME
766 last_assemble_variable_decl = decl;
767 ASM_DECLARE_OBJECT_NAME (file, name, decl);
768 #else
769 /* Standard thing is just output label for the object. */
770 ASM_OUTPUT_LABEL (file, name);
771 #endif /* ASM_DECLARE_OBJECT_NAME */
772 ASM_OUTPUT_SKIP (file, rounded ? rounded : 1);
775 #endif
777 #ifdef ASM_OUTPUT_ALIGNED_BSS
779 /* Utility function for targets to use in implementing
780 ASM_OUTPUT_ALIGNED_BSS.
781 ??? It is believed that this function will work in most cases so such
782 support is localized here. */
784 static void
785 asm_output_aligned_bss (FILE *file, tree decl ATTRIBUTE_UNUSED,
786 const char *name, unsigned HOST_WIDE_INT size,
787 int align)
789 switch_to_section (bss_section);
790 ASM_OUTPUT_ALIGN (file, floor_log2 (align / BITS_PER_UNIT));
791 #ifdef ASM_DECLARE_OBJECT_NAME
792 last_assemble_variable_decl = decl;
793 ASM_DECLARE_OBJECT_NAME (file, name, decl);
794 #else
795 /* Standard thing is just output label for the object. */
796 ASM_OUTPUT_LABEL (file, name);
797 #endif /* ASM_DECLARE_OBJECT_NAME */
798 ASM_OUTPUT_SKIP (file, size ? size : 1);
801 #endif
803 #endif /* BSS_SECTION_ASM_OP */
805 #ifndef USE_SELECT_SECTION_FOR_FUNCTIONS
806 /* Return the hot section for function DECL. Return text_section for
807 null DECLs. */
809 static section *
810 hot_function_section (tree decl)
812 if (decl != NULL_TREE
813 && DECL_SECTION_NAME (decl) != NULL_TREE
814 && targetm.have_named_sections)
815 return get_named_section (decl, NULL, 0);
816 else
817 return text_section;
819 #endif
821 /* Return the section for function DECL.
823 If DECL is NULL_TREE, return the text section. We can be passed
824 NULL_TREE under some circumstances by dbxout.c at least. */
826 section *
827 function_section (tree decl)
829 int reloc = 0;
831 if (first_function_block_is_cold)
832 reloc = 1;
834 #ifdef USE_SELECT_SECTION_FOR_FUNCTIONS
835 if (decl != NULL_TREE
836 && DECL_SECTION_NAME (decl) != NULL_TREE)
837 return reloc ? unlikely_text_section ()
838 : get_named_section (decl, NULL, 0);
839 else
840 return targetm.asm_out.select_section (decl, reloc, DECL_ALIGN (decl));
841 #else
842 return reloc ? unlikely_text_section () : hot_function_section (decl);
843 #endif
846 section *
847 current_function_section (void)
849 #ifdef USE_SELECT_SECTION_FOR_FUNCTIONS
850 if (current_function_decl != NULL_TREE
851 && DECL_SECTION_NAME (current_function_decl) != NULL_TREE)
852 return in_cold_section_p ? unlikely_text_section ()
853 : get_named_section (current_function_decl,
854 NULL, 0);
855 else
856 return targetm.asm_out.select_section (current_function_decl,
857 in_cold_section_p,
858 DECL_ALIGN (current_function_decl));
859 #else
860 return (in_cold_section_p
861 ? unlikely_text_section ()
862 : hot_function_section (current_function_decl));
863 #endif
866 /* Return the read-only data section associated with function DECL. */
868 section *
869 default_function_rodata_section (tree decl)
871 if (decl != NULL_TREE && DECL_SECTION_NAME (decl))
873 const char *name = TREE_STRING_POINTER (DECL_SECTION_NAME (decl));
875 if (DECL_ONE_ONLY (decl) && HAVE_COMDAT_GROUP)
877 const char *dot;
878 size_t len;
879 char* rname;
881 dot = strchr (name + 1, '.');
882 if (!dot)
883 dot = name;
884 len = strlen (dot) + 8;
885 rname = (char *) alloca (len);
887 strcpy (rname, ".rodata");
888 strcat (rname, dot);
889 return get_section (rname, SECTION_LINKONCE, decl);
891 /* For .gnu.linkonce.t.foo we want to use .gnu.linkonce.r.foo. */
892 else if (DECL_ONE_ONLY (decl)
893 && strncmp (name, ".gnu.linkonce.t.", 16) == 0)
895 size_t len = strlen (name) + 1;
896 char *rname = (char *) alloca (len);
898 memcpy (rname, name, len);
899 rname[14] = 'r';
900 return get_section (rname, SECTION_LINKONCE, decl);
902 /* For .text.foo we want to use .rodata.foo. */
903 else if (flag_function_sections && flag_data_sections
904 && strncmp (name, ".text.", 6) == 0)
906 size_t len = strlen (name) + 1;
907 char *rname = (char *) alloca (len + 2);
909 memcpy (rname, ".rodata", 7);
910 memcpy (rname + 7, name + 5, len - 5);
911 return get_section (rname, 0, decl);
915 return readonly_data_section;
918 /* Return the read-only data section associated with function DECL
919 for targets where that section should be always the single
920 readonly data section. */
922 section *
923 default_no_function_rodata_section (tree decl ATTRIBUTE_UNUSED)
925 return readonly_data_section;
928 /* Return the section to use for string merging. */
930 static section *
931 mergeable_string_section (tree decl ATTRIBUTE_UNUSED,
932 unsigned HOST_WIDE_INT align ATTRIBUTE_UNUSED,
933 unsigned int flags ATTRIBUTE_UNUSED)
935 HOST_WIDE_INT len;
937 if (HAVE_GAS_SHF_MERGE && flag_merge_constants
938 && TREE_CODE (decl) == STRING_CST
939 && TREE_CODE (TREE_TYPE (decl)) == ARRAY_TYPE
940 && align <= 256
941 && (len = int_size_in_bytes (TREE_TYPE (decl))) > 0
942 && TREE_STRING_LENGTH (decl) >= len)
944 enum machine_mode mode;
945 unsigned int modesize;
946 const char *str;
947 HOST_WIDE_INT i;
948 int j, unit;
949 char name[30];
951 mode = TYPE_MODE (TREE_TYPE (TREE_TYPE (decl)));
952 modesize = GET_MODE_BITSIZE (mode);
953 if (modesize >= 8 && modesize <= 256
954 && (modesize & (modesize - 1)) == 0)
956 if (align < modesize)
957 align = modesize;
959 str = TREE_STRING_POINTER (decl);
960 unit = GET_MODE_SIZE (mode);
962 /* Check for embedded NUL characters. */
963 for (i = 0; i < len; i += unit)
965 for (j = 0; j < unit; j++)
966 if (str[i + j] != '\0')
967 break;
968 if (j == unit)
969 break;
971 if (i == len - unit)
973 sprintf (name, ".rodata.str%d.%d", modesize / 8,
974 (int) (align / 8));
975 flags |= (modesize / 8) | SECTION_MERGE | SECTION_STRINGS;
976 return get_section (name, flags, NULL);
981 return readonly_data_section;
984 /* Return the section to use for constant merging. */
986 section *
987 mergeable_constant_section (enum machine_mode mode ATTRIBUTE_UNUSED,
988 unsigned HOST_WIDE_INT align ATTRIBUTE_UNUSED,
989 unsigned int flags ATTRIBUTE_UNUSED)
991 unsigned int modesize = GET_MODE_BITSIZE (mode);
993 if (HAVE_GAS_SHF_MERGE && flag_merge_constants
994 && mode != VOIDmode
995 && mode != BLKmode
996 && modesize <= align
997 && align >= 8
998 && align <= 256
999 && (align & (align - 1)) == 0)
1001 char name[24];
1003 sprintf (name, ".rodata.cst%d", (int) (align / 8));
1004 flags |= (align / 8) | SECTION_MERGE;
1005 return get_section (name, flags, NULL);
1007 return readonly_data_section;
1010 /* Given NAME, a putative register name, discard any customary prefixes. */
1012 static const char *
1013 strip_reg_name (const char *name)
1015 #ifdef REGISTER_PREFIX
1016 if (!strncmp (name, REGISTER_PREFIX, strlen (REGISTER_PREFIX)))
1017 name += strlen (REGISTER_PREFIX);
1018 #endif
1019 if (name[0] == '%' || name[0] == '#')
1020 name++;
1021 return name;
1024 /* The user has asked for a DECL to have a particular name. Set (or
1025 change) it in such a way that we don't prefix an underscore to
1026 it. */
1027 void
1028 set_user_assembler_name (tree decl, const char *name)
1030 char *starred = (char *) alloca (strlen (name) + 2);
1031 starred[0] = '*';
1032 strcpy (starred + 1, name);
1033 change_decl_assembler_name (decl, get_identifier (starred));
1034 SET_DECL_RTL (decl, NULL_RTX);
1037 /* Decode an `asm' spec for a declaration as a register name.
1038 Return the register number, or -1 if nothing specified,
1039 or -2 if the ASMSPEC is not `cc' or `memory' and is not recognized,
1040 or -3 if ASMSPEC is `cc' and is not recognized,
1041 or -4 if ASMSPEC is `memory' and is not recognized.
1042 Accept an exact spelling or a decimal number.
1043 Prefixes such as % are optional. */
1046 decode_reg_name (const char *asmspec)
1048 if (asmspec != 0)
1050 int i;
1052 /* Get rid of confusing prefixes. */
1053 asmspec = strip_reg_name (asmspec);
1055 /* Allow a decimal number as a "register name". */
1056 for (i = strlen (asmspec) - 1; i >= 0; i--)
1057 if (! ISDIGIT (asmspec[i]))
1058 break;
1059 if (asmspec[0] != 0 && i < 0)
1061 i = atoi (asmspec);
1062 if (i < FIRST_PSEUDO_REGISTER && i >= 0)
1063 return i;
1064 else
1065 return -2;
1068 for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
1069 if (reg_names[i][0]
1070 && ! strcmp (asmspec, strip_reg_name (reg_names[i])))
1071 return i;
1073 #ifdef ADDITIONAL_REGISTER_NAMES
1075 static const struct { const char *const name; const int number; } table[]
1076 = ADDITIONAL_REGISTER_NAMES;
1078 for (i = 0; i < (int) ARRAY_SIZE (table); i++)
1079 if (table[i].name[0]
1080 && ! strcmp (asmspec, table[i].name))
1081 return table[i].number;
1083 #endif /* ADDITIONAL_REGISTER_NAMES */
1085 if (!strcmp (asmspec, "memory"))
1086 return -4;
1088 if (!strcmp (asmspec, "cc"))
1089 return -3;
1091 return -2;
1094 return -1;
1097 /* Return true if DECL's initializer is suitable for a BSS section. */
1099 static bool
1100 bss_initializer_p (const_tree decl)
1102 return (DECL_INITIAL (decl) == NULL
1103 || DECL_INITIAL (decl) == error_mark_node
1104 || (flag_zero_initialized_in_bss
1105 /* Leave constant zeroes in .rodata so they
1106 can be shared. */
1107 && !TREE_READONLY (decl)
1108 && initializer_zerop (DECL_INITIAL (decl))));
1111 /* Compute the alignment of variable specified by DECL.
1112 DONT_OUTPUT_DATA is from assemble_variable. */
1114 void
1115 align_variable (tree decl, bool dont_output_data)
1117 unsigned int align = DECL_ALIGN (decl);
1119 /* In the case for initialing an array whose length isn't specified,
1120 where we have not yet been able to do the layout,
1121 figure out the proper alignment now. */
1122 if (dont_output_data && DECL_SIZE (decl) == 0
1123 && TREE_CODE (TREE_TYPE (decl)) == ARRAY_TYPE)
1124 align = MAX (align, TYPE_ALIGN (TREE_TYPE (TREE_TYPE (decl))));
1126 /* Some object file formats have a maximum alignment which they support.
1127 In particular, a.out format supports a maximum alignment of 4. */
1128 if (align > MAX_OFILE_ALIGNMENT)
1130 warning (0, "alignment of %q+D is greater than maximum object "
1131 "file alignment. Using %d", decl,
1132 MAX_OFILE_ALIGNMENT/BITS_PER_UNIT);
1133 align = MAX_OFILE_ALIGNMENT;
1136 /* On some machines, it is good to increase alignment sometimes. */
1137 if (! DECL_USER_ALIGN (decl))
1139 #ifdef DATA_ALIGNMENT
1140 unsigned int data_align = DATA_ALIGNMENT (TREE_TYPE (decl), align);
1141 /* Don't increase alignment too much for TLS variables - TLS space
1142 is too precious. */
1143 if (! DECL_THREAD_LOCAL_P (decl) || data_align <= BITS_PER_WORD)
1144 align = data_align;
1145 #endif
1146 #ifdef CONSTANT_ALIGNMENT
1147 if (DECL_INITIAL (decl) != 0 && DECL_INITIAL (decl) != error_mark_node)
1149 unsigned int const_align = CONSTANT_ALIGNMENT (DECL_INITIAL (decl),
1150 align);
1151 /* Don't increase alignment too much for TLS variables - TLS space
1152 is too precious. */
1153 if (! DECL_THREAD_LOCAL_P (decl) || const_align <= BITS_PER_WORD)
1154 align = const_align;
1156 #endif
1159 /* Reset the alignment in case we have made it tighter, so we can benefit
1160 from it in get_pointer_alignment. */
1161 DECL_ALIGN (decl) = align;
1164 /* Return the section into which the given VAR_DECL or CONST_DECL
1165 should be placed. PREFER_NOSWITCH_P is true if a noswitch
1166 section should be used wherever possible. */
1168 static section *
1169 get_variable_section (tree decl, bool prefer_noswitch_p)
1171 int reloc;
1173 /* If the decl has been given an explicit section name, then it
1174 isn't common, and shouldn't be handled as such. */
1175 if (DECL_COMMON (decl) && DECL_SECTION_NAME (decl) == NULL)
1177 if (DECL_THREAD_LOCAL_P (decl))
1178 return tls_comm_section;
1179 /* This cannot be common bss for an emulated TLS object without
1180 a register_common hook. */
1181 else if (DECL_TLS_MODEL (decl) == TLS_MODEL_EMULATED
1182 && !targetm.emutls.register_common)
1184 else if (TREE_PUBLIC (decl) && bss_initializer_p (decl))
1185 return comm_section;
1188 if (DECL_INITIAL (decl) == error_mark_node)
1189 reloc = contains_pointers_p (TREE_TYPE (decl)) ? 3 : 0;
1190 else if (DECL_INITIAL (decl))
1191 reloc = compute_reloc_for_constant (DECL_INITIAL (decl));
1192 else
1193 reloc = 0;
1195 resolve_unique_section (decl, reloc, flag_data_sections);
1196 if (IN_NAMED_SECTION (decl))
1197 return get_named_section (decl, NULL, reloc);
1199 if (!DECL_THREAD_LOCAL_P (decl)
1200 && !(prefer_noswitch_p && targetm.have_switchable_bss_sections)
1201 && bss_initializer_p (decl))
1203 if (!TREE_PUBLIC (decl))
1204 return lcomm_section;
1205 if (bss_noswitch_section)
1206 return bss_noswitch_section;
1209 return targetm.asm_out.select_section (decl, reloc, DECL_ALIGN (decl));
1212 /* Return the block into which object_block DECL should be placed. */
1214 static struct object_block *
1215 get_block_for_decl (tree decl)
1217 section *sect;
1219 if (TREE_CODE (decl) == VAR_DECL)
1221 /* The object must be defined in this translation unit. */
1222 if (DECL_EXTERNAL (decl))
1223 return NULL;
1225 /* There's no point using object blocks for something that is
1226 isolated by definition. */
1227 if (DECL_ONE_ONLY (decl))
1228 return NULL;
1231 /* We can only calculate block offsets if the decl has a known
1232 constant size. */
1233 if (DECL_SIZE_UNIT (decl) == NULL)
1234 return NULL;
1235 if (!host_integerp (DECL_SIZE_UNIT (decl), 1))
1236 return NULL;
1238 /* Find out which section should contain DECL. We cannot put it into
1239 an object block if it requires a standalone definition. */
1240 if (TREE_CODE (decl) == VAR_DECL)
1241 align_variable (decl, 0);
1242 sect = get_variable_section (decl, true);
1243 if (SECTION_STYLE (sect) == SECTION_NOSWITCH)
1244 return NULL;
1246 return get_block_for_section (sect);
1249 /* Make sure block symbol SYMBOL is in block BLOCK. */
1251 static void
1252 change_symbol_block (rtx symbol, struct object_block *block)
1254 if (block != SYMBOL_REF_BLOCK (symbol))
1256 gcc_assert (SYMBOL_REF_BLOCK_OFFSET (symbol) < 0);
1257 SYMBOL_REF_BLOCK (symbol) = block;
1261 /* Return true if it is possible to put DECL in an object_block. */
1263 static bool
1264 use_blocks_for_decl_p (tree decl)
1266 /* Only data DECLs can be placed into object blocks. */
1267 if (TREE_CODE (decl) != VAR_DECL && TREE_CODE (decl) != CONST_DECL)
1268 return false;
1270 /* Detect decls created by dw2_force_const_mem. Such decls are
1271 special because DECL_INITIAL doesn't specify the decl's true value.
1272 dw2_output_indirect_constants will instead call assemble_variable
1273 with dont_output_data set to 1 and then print the contents itself. */
1274 if (DECL_INITIAL (decl) == decl)
1275 return false;
1277 /* If this decl is an alias, then we don't want to emit a definition. */
1278 if (lookup_attribute ("alias", DECL_ATTRIBUTES (decl)))
1279 return false;
1281 return true;
1284 /* Create the DECL_RTL for a VAR_DECL or FUNCTION_DECL. DECL should
1285 have static storage duration. In other words, it should not be an
1286 automatic variable, including PARM_DECLs.
1288 There is, however, one exception: this function handles variables
1289 explicitly placed in a particular register by the user.
1291 This is never called for PARM_DECL nodes. */
1293 void
1294 make_decl_rtl (tree decl)
1296 const char *name = 0;
1297 int reg_number;
1298 rtx x;
1300 /* Check that we are not being given an automatic variable. */
1301 gcc_assert (TREE_CODE (decl) != PARM_DECL
1302 && TREE_CODE (decl) != RESULT_DECL);
1304 /* A weak alias has TREE_PUBLIC set but not the other bits. */
1305 gcc_assert (TREE_CODE (decl) != VAR_DECL
1306 || TREE_STATIC (decl)
1307 || TREE_PUBLIC (decl)
1308 || DECL_EXTERNAL (decl)
1309 || DECL_REGISTER (decl));
1311 /* And that we were not given a type or a label. */
1312 gcc_assert (TREE_CODE (decl) != TYPE_DECL
1313 && TREE_CODE (decl) != LABEL_DECL);
1315 /* For a duplicate declaration, we can be called twice on the
1316 same DECL node. Don't discard the RTL already made. */
1317 if (DECL_RTL_SET_P (decl))
1319 /* If the old RTL had the wrong mode, fix the mode. */
1320 x = DECL_RTL (decl);
1321 if (GET_MODE (x) != DECL_MODE (decl))
1322 SET_DECL_RTL (decl, adjust_address_nv (x, DECL_MODE (decl), 0));
1324 if (TREE_CODE (decl) != FUNCTION_DECL && DECL_REGISTER (decl))
1325 return;
1327 /* ??? Another way to do this would be to maintain a hashed
1328 table of such critters. Instead of adding stuff to a DECL
1329 to give certain attributes to it, we could use an external
1330 hash map from DECL to set of attributes. */
1332 /* Let the target reassign the RTL if it wants.
1333 This is necessary, for example, when one machine specific
1334 decl attribute overrides another. */
1335 targetm.encode_section_info (decl, DECL_RTL (decl), false);
1337 /* If the symbol has a SYMBOL_REF_BLOCK field, update it based
1338 on the new decl information. */
1339 if (MEM_P (x)
1340 && GET_CODE (XEXP (x, 0)) == SYMBOL_REF
1341 && SYMBOL_REF_HAS_BLOCK_INFO_P (XEXP (x, 0)))
1342 change_symbol_block (XEXP (x, 0), get_block_for_decl (decl));
1344 /* Make this function static known to the mudflap runtime. */
1345 if (flag_mudflap && TREE_CODE (decl) == VAR_DECL)
1346 mudflap_enqueue_decl (decl);
1348 return;
1351 name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
1353 if (name[0] != '*' && TREE_CODE (decl) != FUNCTION_DECL
1354 && DECL_REGISTER (decl))
1356 error ("register name not specified for %q+D", decl);
1358 else if (TREE_CODE (decl) != FUNCTION_DECL && DECL_REGISTER (decl))
1360 const char *asmspec = name+1;
1361 reg_number = decode_reg_name (asmspec);
1362 /* First detect errors in declaring global registers. */
1363 if (reg_number == -1)
1364 error ("register name not specified for %q+D", decl);
1365 else if (reg_number < 0)
1366 error ("invalid register name for %q+D", decl);
1367 else if (TYPE_MODE (TREE_TYPE (decl)) == BLKmode)
1368 error ("data type of %q+D isn%'t suitable for a register",
1369 decl);
1370 else if (! HARD_REGNO_MODE_OK (reg_number, TYPE_MODE (TREE_TYPE (decl))))
1371 error ("register specified for %q+D isn%'t suitable for data type",
1372 decl);
1373 /* Now handle properly declared static register variables. */
1374 else
1376 int nregs;
1378 if (DECL_INITIAL (decl) != 0 && TREE_STATIC (decl))
1380 DECL_INITIAL (decl) = 0;
1381 error ("global register variable has initial value");
1383 if (TREE_THIS_VOLATILE (decl))
1384 warning (OPT_Wvolatile_register_var,
1385 "optimization may eliminate reads and/or "
1386 "writes to register variables");
1388 /* If the user specified one of the eliminables registers here,
1389 e.g., FRAME_POINTER_REGNUM, we don't want to get this variable
1390 confused with that register and be eliminated. This usage is
1391 somewhat suspect... */
1393 SET_DECL_RTL (decl, gen_rtx_raw_REG (DECL_MODE (decl), reg_number));
1394 ORIGINAL_REGNO (DECL_RTL (decl)) = reg_number;
1395 REG_USERVAR_P (DECL_RTL (decl)) = 1;
1397 if (TREE_STATIC (decl))
1399 /* Make this register global, so not usable for anything
1400 else. */
1401 #ifdef ASM_DECLARE_REGISTER_GLOBAL
1402 name = IDENTIFIER_POINTER (DECL_NAME (decl));
1403 ASM_DECLARE_REGISTER_GLOBAL (asm_out_file, decl, reg_number, name);
1404 #endif
1405 nregs = hard_regno_nregs[reg_number][DECL_MODE (decl)];
1406 while (nregs > 0)
1407 globalize_reg (reg_number + --nregs);
1410 /* As a register variable, it has no section. */
1411 return;
1414 /* Now handle ordinary static variables and functions (in memory).
1415 Also handle vars declared register invalidly. */
1416 else if (name[0] == '*')
1418 #ifdef REGISTER_PREFIX
1419 if (strlen (REGISTER_PREFIX) != 0)
1421 reg_number = decode_reg_name (name);
1422 if (reg_number >= 0 || reg_number == -3)
1423 error ("register name given for non-register variable %q+D", decl);
1425 #endif
1428 /* Specifying a section attribute on a variable forces it into a
1429 non-.bss section, and thus it cannot be common. */
1430 if (TREE_CODE (decl) == VAR_DECL
1431 && DECL_SECTION_NAME (decl) != NULL_TREE
1432 && DECL_INITIAL (decl) == NULL_TREE
1433 && DECL_COMMON (decl))
1434 DECL_COMMON (decl) = 0;
1436 /* Variables can't be both common and weak. */
1437 if (TREE_CODE (decl) == VAR_DECL && DECL_WEAK (decl))
1438 DECL_COMMON (decl) = 0;
1440 if (use_object_blocks_p () && use_blocks_for_decl_p (decl))
1441 x = create_block_symbol (name, get_block_for_decl (decl), -1);
1442 else
1443 x = gen_rtx_SYMBOL_REF (Pmode, name);
1444 SYMBOL_REF_WEAK (x) = DECL_WEAK (decl);
1445 SET_SYMBOL_REF_DECL (x, decl);
1447 x = gen_rtx_MEM (DECL_MODE (decl), x);
1448 if (TREE_CODE (decl) != FUNCTION_DECL)
1449 set_mem_attributes (x, decl, 1);
1450 SET_DECL_RTL (decl, x);
1452 /* Optionally set flags or add text to the name to record information
1453 such as that it is a function name.
1454 If the name is changed, the macro ASM_OUTPUT_LABELREF
1455 will have to know how to strip this information. */
1456 targetm.encode_section_info (decl, DECL_RTL (decl), true);
1458 /* Make this function static known to the mudflap runtime. */
1459 if (flag_mudflap && TREE_CODE (decl) == VAR_DECL)
1460 mudflap_enqueue_decl (decl);
1463 /* Output a string of literal assembler code
1464 for an `asm' keyword used between functions. */
1466 void
1467 assemble_asm (tree string)
1469 app_enable ();
1471 if (TREE_CODE (string) == ADDR_EXPR)
1472 string = TREE_OPERAND (string, 0);
1474 fprintf (asm_out_file, "\t%s\n", TREE_STRING_POINTER (string));
1477 /* Record an element in the table of global destructors. SYMBOL is
1478 a SYMBOL_REF of the function to be called; PRIORITY is a number
1479 between 0 and MAX_INIT_PRIORITY. */
1481 void
1482 default_stabs_asm_out_destructor (rtx symbol ATTRIBUTE_UNUSED,
1483 int priority ATTRIBUTE_UNUSED)
1485 #if defined DBX_DEBUGGING_INFO || defined XCOFF_DEBUGGING_INFO
1486 /* Tell GNU LD that this is part of the static destructor set.
1487 This will work for any system that uses stabs, most usefully
1488 aout systems. */
1489 dbxout_begin_simple_stabs ("___DTOR_LIST__", 22 /* N_SETT */);
1490 dbxout_stab_value_label (XSTR (symbol, 0));
1491 #else
1492 sorry ("global destructors not supported on this target");
1493 #endif
1496 /* Write the address of the entity given by SYMBOL to SEC. */
1497 void
1498 assemble_addr_to_section (rtx symbol, section *sec)
1500 switch_to_section (sec);
1501 assemble_align (POINTER_SIZE);
1502 assemble_integer (symbol, POINTER_SIZE / BITS_PER_UNIT, POINTER_SIZE, 1);
1505 /* Return the numbered .ctors.N (if CONSTRUCTOR_P) or .dtors.N (if
1506 not) section for PRIORITY. */
1507 section *
1508 get_cdtor_priority_section (int priority, bool constructor_p)
1510 char buf[16];
1512 /* ??? This only works reliably with the GNU linker. */
1513 sprintf (buf, "%s.%.5u",
1514 constructor_p ? ".ctors" : ".dtors",
1515 /* Invert the numbering so the linker puts us in the proper
1516 order; constructors are run from right to left, and the
1517 linker sorts in increasing order. */
1518 MAX_INIT_PRIORITY - priority);
1519 return get_section (buf, SECTION_WRITE, NULL);
1522 void
1523 default_named_section_asm_out_destructor (rtx symbol, int priority)
1525 section *sec;
1527 if (priority != DEFAULT_INIT_PRIORITY)
1528 sec = get_cdtor_priority_section (priority,
1529 /*constructor_p=*/false);
1530 else
1531 sec = get_section (".dtors", SECTION_WRITE, NULL);
1533 assemble_addr_to_section (symbol, sec);
1536 #ifdef DTORS_SECTION_ASM_OP
1537 void
1538 default_dtor_section_asm_out_destructor (rtx symbol,
1539 int priority ATTRIBUTE_UNUSED)
1541 assemble_addr_to_section (symbol, dtors_section);
1543 #endif
1545 /* Likewise for global constructors. */
1547 void
1548 default_stabs_asm_out_constructor (rtx symbol ATTRIBUTE_UNUSED,
1549 int priority ATTRIBUTE_UNUSED)
1551 #if defined DBX_DEBUGGING_INFO || defined XCOFF_DEBUGGING_INFO
1552 /* Tell GNU LD that this is part of the static destructor set.
1553 This will work for any system that uses stabs, most usefully
1554 aout systems. */
1555 dbxout_begin_simple_stabs ("___CTOR_LIST__", 22 /* N_SETT */);
1556 dbxout_stab_value_label (XSTR (symbol, 0));
1557 #else
1558 sorry ("global constructors not supported on this target");
1559 #endif
1562 void
1563 default_named_section_asm_out_constructor (rtx symbol, int priority)
1565 section *sec;
1567 if (priority != DEFAULT_INIT_PRIORITY)
1568 sec = get_cdtor_priority_section (priority,
1569 /*constructor_p=*/true);
1570 else
1571 sec = get_section (".ctors", SECTION_WRITE, NULL);
1573 assemble_addr_to_section (symbol, sec);
1576 #ifdef CTORS_SECTION_ASM_OP
1577 void
1578 default_ctor_section_asm_out_constructor (rtx symbol,
1579 int priority ATTRIBUTE_UNUSED)
1581 assemble_addr_to_section (symbol, ctors_section);
1583 #endif
1585 /* CONSTANT_POOL_BEFORE_FUNCTION may be defined as an expression with
1586 a nonzero value if the constant pool should be output before the
1587 start of the function, or a zero value if the pool should output
1588 after the end of the function. The default is to put it before the
1589 start. */
1591 #ifndef CONSTANT_POOL_BEFORE_FUNCTION
1592 #define CONSTANT_POOL_BEFORE_FUNCTION 1
1593 #endif
1595 /* DECL is an object (either VAR_DECL or FUNCTION_DECL) which is going
1596 to be output to assembler.
1597 Set first_global_object_name and weak_global_object_name as appropriate. */
1599 void
1600 notice_global_symbol (tree decl)
1602 const char **type = &first_global_object_name;
1604 if (first_global_object_name
1605 || !TREE_PUBLIC (decl)
1606 || DECL_EXTERNAL (decl)
1607 || !DECL_NAME (decl)
1608 || (TREE_CODE (decl) != FUNCTION_DECL
1609 && (TREE_CODE (decl) != VAR_DECL
1610 || (DECL_COMMON (decl)
1611 && (DECL_INITIAL (decl) == 0
1612 || DECL_INITIAL (decl) == error_mark_node))))
1613 || !MEM_P (DECL_RTL (decl)))
1614 return;
1616 /* We win when global object is found, but it is useful to know about weak
1617 symbol as well so we can produce nicer unique names. */
1618 if (DECL_WEAK (decl) || DECL_ONE_ONLY (decl) || flag_shlib)
1619 type = &weak_global_object_name;
1621 if (!*type)
1623 const char *p;
1624 const char *name;
1625 rtx decl_rtl = DECL_RTL (decl);
1627 p = targetm.strip_name_encoding (XSTR (XEXP (decl_rtl, 0), 0));
1628 name = ggc_strdup (p);
1630 *type = name;
1634 /* Output assembler code for the constant pool of a function and associated
1635 with defining the name of the function. DECL describes the function.
1636 NAME is the function's name. For the constant pool, we use the current
1637 constant pool data. */
1639 void
1640 assemble_start_function (tree decl, const char *fnname)
1642 int align;
1643 char tmp_label[100];
1644 bool hot_label_written = false;
1646 crtl->subsections.unlikely_text_section_name = NULL;
1648 first_function_block_is_cold = false;
1649 if (flag_reorder_blocks_and_partition)
1651 ASM_GENERATE_INTERNAL_LABEL (tmp_label, "LHOTB", const_labelno);
1652 crtl->subsections.hot_section_label = ggc_strdup (tmp_label);
1653 ASM_GENERATE_INTERNAL_LABEL (tmp_label, "LCOLDB", const_labelno);
1654 crtl->subsections.cold_section_label = ggc_strdup (tmp_label);
1655 ASM_GENERATE_INTERNAL_LABEL (tmp_label, "LHOTE", const_labelno);
1656 crtl->subsections.hot_section_end_label = ggc_strdup (tmp_label);
1657 ASM_GENERATE_INTERNAL_LABEL (tmp_label, "LCOLDE", const_labelno);
1658 crtl->subsections.cold_section_end_label = ggc_strdup (tmp_label);
1659 const_labelno++;
1661 else
1663 crtl->subsections.hot_section_label = NULL;
1664 crtl->subsections.cold_section_label = NULL;
1665 crtl->subsections.hot_section_end_label = NULL;
1666 crtl->subsections.cold_section_end_label = NULL;
1669 /* The following code does not need preprocessing in the assembler. */
1671 app_disable ();
1673 if (CONSTANT_POOL_BEFORE_FUNCTION)
1674 output_constant_pool (fnname, decl);
1676 resolve_unique_section (decl, 0, flag_function_sections);
1678 /* Make sure the not and cold text (code) sections are properly
1679 aligned. This is necessary here in the case where the function
1680 has both hot and cold sections, because we don't want to re-set
1681 the alignment when the section switch happens mid-function. */
1683 if (flag_reorder_blocks_and_partition)
1685 switch_to_section (unlikely_text_section ());
1686 assemble_align (DECL_ALIGN (decl));
1687 ASM_OUTPUT_LABEL (asm_out_file, crtl->subsections.cold_section_label);
1689 /* When the function starts with a cold section, we need to explicitly
1690 align the hot section and write out the hot section label.
1691 But if the current function is a thunk, we do not have a CFG. */
1692 if (!cfun->is_thunk
1693 && BB_PARTITION (ENTRY_BLOCK_PTR->next_bb) == BB_COLD_PARTITION)
1695 switch_to_section (text_section);
1696 assemble_align (DECL_ALIGN (decl));
1697 ASM_OUTPUT_LABEL (asm_out_file, crtl->subsections.hot_section_label);
1698 hot_label_written = true;
1699 first_function_block_is_cold = true;
1702 else if (DECL_SECTION_NAME (decl))
1704 /* Calls to function_section rely on first_function_block_is_cold
1705 being accurate. The first block may be cold even if we aren't
1706 doing partitioning, if the entire function was decided by
1707 choose_function_section (predict.c) to be cold. */
1709 initialize_cold_section_name ();
1711 if (crtl->subsections.unlikely_text_section_name
1712 && strcmp (TREE_STRING_POINTER (DECL_SECTION_NAME (decl)),
1713 crtl->subsections.unlikely_text_section_name) == 0)
1714 first_function_block_is_cold = true;
1717 in_cold_section_p = first_function_block_is_cold;
1719 /* Switch to the correct text section for the start of the function. */
1721 switch_to_section (function_section (decl));
1722 if (flag_reorder_blocks_and_partition
1723 && !hot_label_written)
1724 ASM_OUTPUT_LABEL (asm_out_file, crtl->subsections.hot_section_label);
1726 /* Tell assembler to move to target machine's alignment for functions. */
1727 align = floor_log2 (DECL_ALIGN (decl) / BITS_PER_UNIT);
1728 if (align > 0)
1730 ASM_OUTPUT_ALIGN (asm_out_file, align);
1733 /* Handle a user-specified function alignment.
1734 Note that we still need to align to DECL_ALIGN, as above,
1735 because ASM_OUTPUT_MAX_SKIP_ALIGN might not do any alignment at all. */
1736 if (! DECL_USER_ALIGN (decl)
1737 && align_functions_log > align
1738 && optimize_function_for_speed_p (cfun))
1740 #ifdef ASM_OUTPUT_MAX_SKIP_ALIGN
1741 ASM_OUTPUT_MAX_SKIP_ALIGN (asm_out_file,
1742 align_functions_log, align_functions - 1);
1743 #else
1744 ASM_OUTPUT_ALIGN (asm_out_file, align_functions_log);
1745 #endif
1748 #ifdef ASM_OUTPUT_FUNCTION_PREFIX
1749 ASM_OUTPUT_FUNCTION_PREFIX (asm_out_file, fnname);
1750 #endif
1752 (*debug_hooks->begin_function) (decl);
1754 /* Make function name accessible from other files, if appropriate. */
1756 if (TREE_PUBLIC (decl))
1758 notice_global_symbol (decl);
1760 globalize_decl (decl);
1762 maybe_assemble_visibility (decl);
1765 if (DECL_PRESERVE_P (decl))
1766 targetm.asm_out.mark_decl_preserved (fnname);
1768 /* Do any machine/system dependent processing of the function name. */
1769 #ifdef ASM_DECLARE_FUNCTION_NAME
1770 ASM_DECLARE_FUNCTION_NAME (asm_out_file, fnname, current_function_decl);
1771 #else
1772 /* Standard thing is just output label for the function. */
1773 ASM_OUTPUT_LABEL (asm_out_file, fnname);
1774 #endif /* ASM_DECLARE_FUNCTION_NAME */
1777 /* Output assembler code associated with defining the size of the
1778 function. DECL describes the function. NAME is the function's name. */
1780 void
1781 assemble_end_function (tree decl, const char *fnname ATTRIBUTE_UNUSED)
1783 #ifdef ASM_DECLARE_FUNCTION_SIZE
1784 /* We could have switched section in the middle of the function. */
1785 if (flag_reorder_blocks_and_partition)
1786 switch_to_section (function_section (decl));
1787 ASM_DECLARE_FUNCTION_SIZE (asm_out_file, fnname, decl);
1788 #endif
1789 if (! CONSTANT_POOL_BEFORE_FUNCTION)
1791 output_constant_pool (fnname, decl);
1792 switch_to_section (function_section (decl)); /* need to switch back */
1794 /* Output labels for end of hot/cold text sections (to be used by
1795 debug info.) */
1796 if (flag_reorder_blocks_and_partition)
1798 section *save_text_section;
1800 save_text_section = in_section;
1801 switch_to_section (unlikely_text_section ());
1802 ASM_OUTPUT_LABEL (asm_out_file, crtl->subsections.cold_section_end_label);
1803 if (first_function_block_is_cold)
1804 switch_to_section (text_section);
1805 else
1806 switch_to_section (function_section (decl));
1807 ASM_OUTPUT_LABEL (asm_out_file, crtl->subsections.hot_section_end_label);
1808 switch_to_section (save_text_section);
1812 /* Assemble code to leave SIZE bytes of zeros. */
1814 void
1815 assemble_zeros (unsigned HOST_WIDE_INT size)
1817 /* Do no output if -fsyntax-only. */
1818 if (flag_syntax_only)
1819 return;
1821 #ifdef ASM_NO_SKIP_IN_TEXT
1822 /* The `space' pseudo in the text section outputs nop insns rather than 0s,
1823 so we must output 0s explicitly in the text section. */
1824 if (ASM_NO_SKIP_IN_TEXT && (in_section->common.flags & SECTION_CODE) != 0)
1826 unsigned HOST_WIDE_INT i;
1827 for (i = 0; i < size; i++)
1828 assemble_integer (const0_rtx, 1, BITS_PER_UNIT, 1);
1830 else
1831 #endif
1832 if (size > 0)
1833 ASM_OUTPUT_SKIP (asm_out_file, size);
1836 /* Assemble an alignment pseudo op for an ALIGN-bit boundary. */
1838 void
1839 assemble_align (int align)
1841 if (align > BITS_PER_UNIT)
1843 ASM_OUTPUT_ALIGN (asm_out_file, floor_log2 (align / BITS_PER_UNIT));
1847 /* Assemble a string constant with the specified C string as contents. */
1849 void
1850 assemble_string (const char *p, int size)
1852 int pos = 0;
1853 int maximum = 2000;
1855 /* If the string is very long, split it up. */
1857 while (pos < size)
1859 int thissize = size - pos;
1860 if (thissize > maximum)
1861 thissize = maximum;
1863 ASM_OUTPUT_ASCII (asm_out_file, p, thissize);
1865 pos += thissize;
1866 p += thissize;
1871 /* A noswitch_section_callback for lcomm_section. */
1873 static bool
1874 emit_local (tree decl ATTRIBUTE_UNUSED,
1875 const char *name ATTRIBUTE_UNUSED,
1876 unsigned HOST_WIDE_INT size ATTRIBUTE_UNUSED,
1877 unsigned HOST_WIDE_INT rounded ATTRIBUTE_UNUSED)
1879 #if defined ASM_OUTPUT_ALIGNED_DECL_LOCAL
1880 ASM_OUTPUT_ALIGNED_DECL_LOCAL (asm_out_file, decl, name,
1881 size, DECL_ALIGN (decl));
1882 return true;
1883 #elif defined ASM_OUTPUT_ALIGNED_LOCAL
1884 ASM_OUTPUT_ALIGNED_LOCAL (asm_out_file, name, size, DECL_ALIGN (decl));
1885 return true;
1886 #else
1887 ASM_OUTPUT_LOCAL (asm_out_file, name, size, rounded);
1888 return false;
1889 #endif
1892 /* A noswitch_section_callback for bss_noswitch_section. */
1894 #if defined ASM_OUTPUT_ALIGNED_BSS || defined ASM_OUTPUT_BSS
1895 static bool
1896 emit_bss (tree decl ATTRIBUTE_UNUSED,
1897 const char *name ATTRIBUTE_UNUSED,
1898 unsigned HOST_WIDE_INT size ATTRIBUTE_UNUSED,
1899 unsigned HOST_WIDE_INT rounded ATTRIBUTE_UNUSED)
1901 #if defined ASM_OUTPUT_ALIGNED_BSS
1902 ASM_OUTPUT_ALIGNED_BSS (asm_out_file, decl, name, size, DECL_ALIGN (decl));
1903 return true;
1904 #else
1905 ASM_OUTPUT_BSS (asm_out_file, decl, name, size, rounded);
1906 return false;
1907 #endif
1909 #endif
1911 /* A noswitch_section_callback for comm_section. */
1913 static bool
1914 emit_common (tree decl ATTRIBUTE_UNUSED,
1915 const char *name ATTRIBUTE_UNUSED,
1916 unsigned HOST_WIDE_INT size ATTRIBUTE_UNUSED,
1917 unsigned HOST_WIDE_INT rounded ATTRIBUTE_UNUSED)
1919 #if defined ASM_OUTPUT_ALIGNED_DECL_COMMON
1920 ASM_OUTPUT_ALIGNED_DECL_COMMON (asm_out_file, decl, name,
1921 size, DECL_ALIGN (decl));
1922 return true;
1923 #elif defined ASM_OUTPUT_ALIGNED_COMMON
1924 ASM_OUTPUT_ALIGNED_COMMON (asm_out_file, name, size, DECL_ALIGN (decl));
1925 return true;
1926 #else
1927 ASM_OUTPUT_COMMON (asm_out_file, name, size, rounded);
1928 return false;
1929 #endif
1932 /* A noswitch_section_callback for tls_comm_section. */
1934 static bool
1935 emit_tls_common (tree decl ATTRIBUTE_UNUSED,
1936 const char *name ATTRIBUTE_UNUSED,
1937 unsigned HOST_WIDE_INT size ATTRIBUTE_UNUSED,
1938 unsigned HOST_WIDE_INT rounded ATTRIBUTE_UNUSED)
1940 #ifdef ASM_OUTPUT_TLS_COMMON
1941 ASM_OUTPUT_TLS_COMMON (asm_out_file, decl, name, size);
1942 return true;
1943 #else
1944 sorry ("thread-local COMMON data not implemented");
1945 return true;
1946 #endif
1949 /* Assemble DECL given that it belongs in SECTION_NOSWITCH section SECT.
1950 NAME is the name of DECL's SYMBOL_REF. */
1952 static void
1953 assemble_noswitch_variable (tree decl, const char *name, section *sect)
1955 unsigned HOST_WIDE_INT size, rounded;
1957 size = tree_low_cst (DECL_SIZE_UNIT (decl), 1);
1958 rounded = size;
1960 /* Don't allocate zero bytes of common,
1961 since that means "undefined external" in the linker. */
1962 if (size == 0)
1963 rounded = 1;
1965 /* Round size up to multiple of BIGGEST_ALIGNMENT bits
1966 so that each uninitialized object starts on such a boundary. */
1967 rounded += (BIGGEST_ALIGNMENT / BITS_PER_UNIT) - 1;
1968 rounded = (rounded / (BIGGEST_ALIGNMENT / BITS_PER_UNIT)
1969 * (BIGGEST_ALIGNMENT / BITS_PER_UNIT));
1971 if (!sect->noswitch.callback (decl, name, size, rounded)
1972 && (unsigned HOST_WIDE_INT) DECL_ALIGN_UNIT (decl) > rounded)
1973 warning (0, "requested alignment for %q+D is greater than "
1974 "implemented alignment of %wu", decl, rounded);
1977 /* A subroutine of assemble_variable. Output the label and contents of
1978 DECL, whose address is a SYMBOL_REF with name NAME. DONT_OUTPUT_DATA
1979 is as for assemble_variable. */
1981 static void
1982 assemble_variable_contents (tree decl, const char *name,
1983 bool dont_output_data)
1985 /* Do any machine/system dependent processing of the object. */
1986 #ifdef ASM_DECLARE_OBJECT_NAME
1987 last_assemble_variable_decl = decl;
1988 ASM_DECLARE_OBJECT_NAME (asm_out_file, name, decl);
1989 #else
1990 /* Standard thing is just output label for the object. */
1991 ASM_OUTPUT_LABEL (asm_out_file, name);
1992 #endif /* ASM_DECLARE_OBJECT_NAME */
1994 if (!dont_output_data)
1996 if (DECL_INITIAL (decl)
1997 && DECL_INITIAL (decl) != error_mark_node
1998 && !initializer_zerop (DECL_INITIAL (decl)))
1999 /* Output the actual data. */
2000 output_constant (DECL_INITIAL (decl),
2001 tree_low_cst (DECL_SIZE_UNIT (decl), 1),
2002 DECL_ALIGN (decl));
2003 else
2004 /* Leave space for it. */
2005 assemble_zeros (tree_low_cst (DECL_SIZE_UNIT (decl), 1));
2009 /* Initialize emulated tls object TO, which refers to TLS variable
2010 DECL and is initialized by PROXY. */
2012 tree
2013 default_emutls_var_init (tree to, tree decl, tree proxy)
2015 VEC(constructor_elt,gc) *v = VEC_alloc (constructor_elt, gc, 4);
2016 constructor_elt *elt;
2017 tree type = TREE_TYPE (to);
2018 tree field = TYPE_FIELDS (type);
2020 elt = VEC_quick_push (constructor_elt, v, NULL);
2021 elt->index = field;
2022 elt->value = fold_convert (TREE_TYPE (field), DECL_SIZE_UNIT (decl));
2024 elt = VEC_quick_push (constructor_elt, v, NULL);
2025 field = TREE_CHAIN (field);
2026 elt->index = field;
2027 elt->value = build_int_cst (TREE_TYPE (field),
2028 DECL_ALIGN_UNIT (decl));
2030 elt = VEC_quick_push (constructor_elt, v, NULL);
2031 field = TREE_CHAIN (field);
2032 elt->index = field;
2033 elt->value = null_pointer_node;
2035 elt = VEC_quick_push (constructor_elt, v, NULL);
2036 field = TREE_CHAIN (field);
2037 elt->index = field;
2038 elt->value = proxy;
2040 return build_constructor (type, v);
2043 /* Assemble everything that is needed for a variable or function declaration.
2044 Not used for automatic variables, and not used for function definitions.
2045 Should not be called for variables of incomplete structure type.
2047 TOP_LEVEL is nonzero if this variable has file scope.
2048 AT_END is nonzero if this is the special handling, at end of compilation,
2049 to define things that have had only tentative definitions.
2050 DONT_OUTPUT_DATA if nonzero means don't actually output the
2051 initial value (that will be done by the caller). */
2053 void
2054 assemble_variable (tree decl, int top_level ATTRIBUTE_UNUSED,
2055 int at_end ATTRIBUTE_UNUSED, int dont_output_data)
2057 const char *name;
2058 rtx decl_rtl, symbol;
2059 section *sect;
2061 if (! targetm.have_tls
2062 && TREE_CODE (decl) == VAR_DECL
2063 && DECL_THREAD_LOCAL_P (decl))
2065 tree to = emutls_decl (decl);
2067 /* If this variable is defined locally, then we need to initialize the
2068 control structure with size and alignment information. We do this
2069 at the last moment because tentative definitions can take a locally
2070 defined but uninitialized variable and initialize it later, which
2071 would result in incorrect contents. */
2072 if (! DECL_EXTERNAL (to)
2073 && (! DECL_COMMON (to)
2074 || (DECL_INITIAL (decl)
2075 && DECL_INITIAL (decl) != error_mark_node)))
2077 DECL_INITIAL (to) = targetm.emutls.var_init
2078 (to, decl, get_emutls_init_templ_addr (decl));
2080 /* Make sure the template is marked as needed early enough.
2081 Without this, if the variable is placed in a
2082 section-anchored block, the template will only be marked
2083 when it's too late. */
2084 record_references_in_initializer (to);
2087 decl = to;
2090 last_assemble_variable_decl = 0;
2092 /* Normally no need to say anything here for external references,
2093 since assemble_external is called by the language-specific code
2094 when a declaration is first seen. */
2096 if (DECL_EXTERNAL (decl))
2097 return;
2099 /* Output no assembler code for a function declaration.
2100 Only definitions of functions output anything. */
2102 if (TREE_CODE (decl) == FUNCTION_DECL)
2103 return;
2105 /* Do nothing for global register variables. */
2106 if (DECL_RTL_SET_P (decl) && REG_P (DECL_RTL (decl)))
2108 TREE_ASM_WRITTEN (decl) = 1;
2109 return;
2112 /* If type was incomplete when the variable was declared,
2113 see if it is complete now. */
2115 if (DECL_SIZE (decl) == 0)
2116 layout_decl (decl, 0);
2118 /* Still incomplete => don't allocate it; treat the tentative defn
2119 (which is what it must have been) as an `extern' reference. */
2121 if (!dont_output_data && DECL_SIZE (decl) == 0)
2123 error ("storage size of %q+D isn%'t known", decl);
2124 TREE_ASM_WRITTEN (decl) = 1;
2125 return;
2128 /* The first declaration of a variable that comes through this function
2129 decides whether it is global (in C, has external linkage)
2130 or local (in C, has internal linkage). So do nothing more
2131 if this function has already run. */
2133 if (TREE_ASM_WRITTEN (decl))
2134 return;
2136 /* Make sure targetm.encode_section_info is invoked before we set
2137 ASM_WRITTEN. */
2138 decl_rtl = DECL_RTL (decl);
2140 TREE_ASM_WRITTEN (decl) = 1;
2142 /* Do no output if -fsyntax-only. */
2143 if (flag_syntax_only)
2144 return;
2146 app_disable ();
2148 if (! dont_output_data
2149 && ! host_integerp (DECL_SIZE_UNIT (decl), 1))
2151 error ("size of variable %q+D is too large", decl);
2152 return;
2155 gcc_assert (MEM_P (decl_rtl));
2156 gcc_assert (GET_CODE (XEXP (decl_rtl, 0)) == SYMBOL_REF);
2157 symbol = XEXP (decl_rtl, 0);
2158 name = XSTR (symbol, 0);
2159 if (TREE_PUBLIC (decl) && DECL_NAME (decl))
2160 notice_global_symbol (decl);
2162 /* Compute the alignment of this data. */
2164 align_variable (decl, dont_output_data);
2165 set_mem_align (decl_rtl, DECL_ALIGN (decl));
2167 if (TREE_PUBLIC (decl))
2168 maybe_assemble_visibility (decl);
2170 if (DECL_PRESERVE_P (decl))
2171 targetm.asm_out.mark_decl_preserved (name);
2173 /* First make the assembler name(s) global if appropriate. */
2174 sect = get_variable_section (decl, false);
2175 if (TREE_PUBLIC (decl)
2176 && (sect->common.flags & SECTION_COMMON) == 0)
2177 globalize_decl (decl);
2179 /* Output any data that we will need to use the address of. */
2180 if (DECL_INITIAL (decl) && DECL_INITIAL (decl) != error_mark_node)
2181 output_addressed_constants (DECL_INITIAL (decl));
2183 /* dbxout.c needs to know this. */
2184 if (sect && (sect->common.flags & SECTION_CODE) != 0)
2185 DECL_IN_TEXT_SECTION (decl) = 1;
2187 /* If the decl is part of an object_block, make sure that the decl
2188 has been positioned within its block, but do not write out its
2189 definition yet. output_object_blocks will do that later. */
2190 if (SYMBOL_REF_HAS_BLOCK_INFO_P (symbol) && SYMBOL_REF_BLOCK (symbol))
2192 gcc_assert (!dont_output_data);
2193 place_block_symbol (symbol);
2195 else if (SECTION_STYLE (sect) == SECTION_NOSWITCH)
2196 assemble_noswitch_variable (decl, name, sect);
2197 else
2199 switch_to_section (sect);
2200 if (DECL_ALIGN (decl) > BITS_PER_UNIT)
2201 ASM_OUTPUT_ALIGN (asm_out_file, floor_log2 (DECL_ALIGN_UNIT (decl)));
2202 assemble_variable_contents (decl, name, dont_output_data);
2206 /* Return 1 if type TYPE contains any pointers. */
2208 static int
2209 contains_pointers_p (tree type)
2211 switch (TREE_CODE (type))
2213 case POINTER_TYPE:
2214 case REFERENCE_TYPE:
2215 /* I'm not sure whether OFFSET_TYPE needs this treatment,
2216 so I'll play safe and return 1. */
2217 case OFFSET_TYPE:
2218 return 1;
2220 case RECORD_TYPE:
2221 case UNION_TYPE:
2222 case QUAL_UNION_TYPE:
2224 tree fields;
2225 /* For a type that has fields, see if the fields have pointers. */
2226 for (fields = TYPE_FIELDS (type); fields; fields = TREE_CHAIN (fields))
2227 if (TREE_CODE (fields) == FIELD_DECL
2228 && contains_pointers_p (TREE_TYPE (fields)))
2229 return 1;
2230 return 0;
2233 case ARRAY_TYPE:
2234 /* An array type contains pointers if its element type does. */
2235 return contains_pointers_p (TREE_TYPE (type));
2237 default:
2238 return 0;
2242 /* We delay assemble_external processing until
2243 the compilation unit is finalized. This is the best we can do for
2244 right now (i.e. stage 3 of GCC 4.0) - the right thing is to delay
2245 it all the way to final. See PR 17982 for further discussion. */
2246 static GTY(()) tree pending_assemble_externals;
2248 #ifdef ASM_OUTPUT_EXTERNAL
2249 /* True if DECL is a function decl for which no out-of-line copy exists.
2250 It is assumed that DECL's assembler name has been set. */
2252 static bool
2253 incorporeal_function_p (tree decl)
2255 if (TREE_CODE (decl) == FUNCTION_DECL && DECL_BUILT_IN (decl))
2257 const char *name;
2259 if (DECL_BUILT_IN_CLASS (decl) == BUILT_IN_NORMAL
2260 && DECL_FUNCTION_CODE (decl) == BUILT_IN_ALLOCA)
2261 return true;
2263 name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
2264 if (is_builtin_name (name))
2265 return true;
2267 return false;
2270 /* Actually do the tests to determine if this is necessary, and invoke
2271 ASM_OUTPUT_EXTERNAL. */
2272 static void
2273 assemble_external_real (tree decl)
2275 rtx rtl = DECL_RTL (decl);
2277 if (MEM_P (rtl) && GET_CODE (XEXP (rtl, 0)) == SYMBOL_REF
2278 && !SYMBOL_REF_USED (XEXP (rtl, 0))
2279 && !incorporeal_function_p (decl))
2281 /* Some systems do require some output. */
2282 SYMBOL_REF_USED (XEXP (rtl, 0)) = 1;
2283 ASM_OUTPUT_EXTERNAL (asm_out_file, decl, XSTR (XEXP (rtl, 0), 0));
2286 #endif
2288 void
2289 process_pending_assemble_externals (void)
2291 #ifdef ASM_OUTPUT_EXTERNAL
2292 tree list;
2293 for (list = pending_assemble_externals; list; list = TREE_CHAIN (list))
2294 assemble_external_real (TREE_VALUE (list));
2296 pending_assemble_externals = 0;
2297 #endif
2300 /* This TREE_LIST contains any weak symbol declarations waiting
2301 to be emitted. */
2302 static GTY(()) tree weak_decls;
2304 /* Output something to declare an external symbol to the assembler,
2305 and qualifiers such as weakness. (Most assemblers don't need
2306 extern declaration, so we normally output nothing.) Do nothing if
2307 DECL is not external. */
2309 void
2310 assemble_external (tree decl ATTRIBUTE_UNUSED)
2312 /* Because most platforms do not define ASM_OUTPUT_EXTERNAL, the
2313 main body of this code is only rarely exercised. To provide some
2314 testing, on all platforms, we make sure that the ASM_OUT_FILE is
2315 open. If it's not, we should not be calling this function. */
2316 gcc_assert (asm_out_file);
2318 if (!DECL_P (decl) || !DECL_EXTERNAL (decl) || !TREE_PUBLIC (decl))
2319 return;
2321 /* We want to output annotation for weak and external symbols at
2322 very last to check if they are references or not. */
2324 if (SUPPORTS_WEAK && DECL_WEAK (decl)
2325 /* TREE_STATIC is a weird and abused creature which is not
2326 generally the right test for whether an entity has been
2327 locally emitted, inlined or otherwise not-really-extern, but
2328 for declarations that can be weak, it happens to be
2329 match. */
2330 && !TREE_STATIC (decl)
2331 && tree_find_value (weak_decls, decl) == NULL_TREE)
2332 weak_decls = tree_cons (NULL, decl, weak_decls);
2334 #ifdef ASM_OUTPUT_EXTERNAL
2335 if (tree_find_value (pending_assemble_externals, decl) == NULL_TREE)
2336 pending_assemble_externals = tree_cons (NULL, decl,
2337 pending_assemble_externals);
2338 #endif
2341 /* Similar, for calling a library function FUN. */
2343 void
2344 assemble_external_libcall (rtx fun)
2346 /* Declare library function name external when first used, if nec. */
2347 if (! SYMBOL_REF_USED (fun))
2349 SYMBOL_REF_USED (fun) = 1;
2350 targetm.asm_out.external_libcall (fun);
2354 /* Assemble a label named NAME. */
2356 void
2357 assemble_label (const char *name)
2359 ASM_OUTPUT_LABEL (asm_out_file, name);
2362 /* Set the symbol_referenced flag for ID. */
2363 void
2364 mark_referenced (tree id)
2366 TREE_SYMBOL_REFERENCED (id) = 1;
2369 /* Set the symbol_referenced flag for DECL and notify callgraph. */
2370 void
2371 mark_decl_referenced (tree decl)
2373 if (TREE_CODE (decl) == FUNCTION_DECL)
2375 /* Extern inline functions don't become needed when referenced.
2376 If we know a method will be emitted in other TU and no new
2377 functions can be marked reachable, just use the external
2378 definition. */
2379 struct cgraph_node *node = cgraph_node (decl);
2380 if (!DECL_EXTERNAL (decl)
2381 && (!node->local.vtable_method || !cgraph_global_info_ready
2382 || !node->local.finalized))
2383 cgraph_mark_needed_node (node);
2385 else if (TREE_CODE (decl) == VAR_DECL)
2387 struct varpool_node *node = varpool_node (decl);
2388 varpool_mark_needed_node (node);
2389 /* C++ frontend use mark_decl_references to force COMDAT variables
2390 to be output that might appear dead otherwise. */
2391 node->force_output = true;
2393 /* else do nothing - we can get various sorts of CST nodes here,
2394 which do not need to be marked. */
2398 /* Follow the IDENTIFIER_TRANSPARENT_ALIAS chain starting at *ALIAS
2399 until we find an identifier that is not itself a transparent alias.
2400 Modify the alias passed to it by reference (and all aliases on the
2401 way to the ultimate target), such that they do not have to be
2402 followed again, and return the ultimate target of the alias
2403 chain. */
2405 static inline tree
2406 ultimate_transparent_alias_target (tree *alias)
2408 tree target = *alias;
2410 if (IDENTIFIER_TRANSPARENT_ALIAS (target))
2412 gcc_assert (TREE_CHAIN (target));
2413 target = ultimate_transparent_alias_target (&TREE_CHAIN (target));
2414 gcc_assert (! IDENTIFIER_TRANSPARENT_ALIAS (target)
2415 && ! TREE_CHAIN (target));
2416 *alias = target;
2419 return target;
2422 /* Output to FILE (an assembly file) a reference to NAME. If NAME
2423 starts with a *, the rest of NAME is output verbatim. Otherwise
2424 NAME is transformed in a target-specific way (usually by the
2425 addition of an underscore). */
2427 void
2428 assemble_name_raw (FILE *file, const char *name)
2430 if (name[0] == '*')
2431 fputs (&name[1], file);
2432 else
2433 ASM_OUTPUT_LABELREF (file, name);
2436 /* Like assemble_name_raw, but should be used when NAME might refer to
2437 an entity that is also represented as a tree (like a function or
2438 variable). If NAME does refer to such an entity, that entity will
2439 be marked as referenced. */
2441 void
2442 assemble_name (FILE *file, const char *name)
2444 const char *real_name;
2445 tree id;
2447 real_name = targetm.strip_name_encoding (name);
2449 id = maybe_get_identifier (real_name);
2450 if (id)
2452 tree id_orig = id;
2454 mark_referenced (id);
2455 ultimate_transparent_alias_target (&id);
2456 if (id != id_orig)
2457 name = IDENTIFIER_POINTER (id);
2458 gcc_assert (! TREE_CHAIN (id));
2461 assemble_name_raw (file, name);
2464 /* Allocate SIZE bytes writable static space with a gensym name
2465 and return an RTX to refer to its address. */
2468 assemble_static_space (unsigned HOST_WIDE_INT size)
2470 char name[12];
2471 const char *namestring;
2472 rtx x;
2474 ASM_GENERATE_INTERNAL_LABEL (name, "LF", const_labelno);
2475 ++const_labelno;
2476 namestring = ggc_strdup (name);
2478 x = gen_rtx_SYMBOL_REF (Pmode, namestring);
2479 SYMBOL_REF_FLAGS (x) = SYMBOL_FLAG_LOCAL;
2481 #ifdef ASM_OUTPUT_ALIGNED_DECL_LOCAL
2482 ASM_OUTPUT_ALIGNED_DECL_LOCAL (asm_out_file, NULL_TREE, name, size,
2483 BIGGEST_ALIGNMENT);
2484 #else
2485 #ifdef ASM_OUTPUT_ALIGNED_LOCAL
2486 ASM_OUTPUT_ALIGNED_LOCAL (asm_out_file, name, size, BIGGEST_ALIGNMENT);
2487 #else
2489 /* Round size up to multiple of BIGGEST_ALIGNMENT bits
2490 so that each uninitialized object starts on such a boundary. */
2491 /* Variable `rounded' might or might not be used in ASM_OUTPUT_LOCAL. */
2492 unsigned HOST_WIDE_INT rounded ATTRIBUTE_UNUSED
2493 = ((size + (BIGGEST_ALIGNMENT / BITS_PER_UNIT) - 1)
2494 / (BIGGEST_ALIGNMENT / BITS_PER_UNIT)
2495 * (BIGGEST_ALIGNMENT / BITS_PER_UNIT));
2496 ASM_OUTPUT_LOCAL (asm_out_file, name, size, rounded);
2498 #endif
2499 #endif
2500 return x;
2503 /* Assemble the static constant template for function entry trampolines.
2504 This is done at most once per compilation.
2505 Returns an RTX for the address of the template. */
2507 static GTY(()) rtx initial_trampoline;
2509 #ifdef TRAMPOLINE_TEMPLATE
2511 assemble_trampoline_template (void)
2513 char label[256];
2514 const char *name;
2515 int align;
2516 rtx symbol;
2518 if (initial_trampoline)
2519 return initial_trampoline;
2521 /* By default, put trampoline templates in read-only data section. */
2523 #ifdef TRAMPOLINE_SECTION
2524 switch_to_section (TRAMPOLINE_SECTION);
2525 #else
2526 switch_to_section (readonly_data_section);
2527 #endif
2529 /* Write the assembler code to define one. */
2530 align = floor_log2 (TRAMPOLINE_ALIGNMENT / BITS_PER_UNIT);
2531 if (align > 0)
2533 ASM_OUTPUT_ALIGN (asm_out_file, align);
2536 targetm.asm_out.internal_label (asm_out_file, "LTRAMP", 0);
2537 TRAMPOLINE_TEMPLATE (asm_out_file);
2539 /* Record the rtl to refer to it. */
2540 ASM_GENERATE_INTERNAL_LABEL (label, "LTRAMP", 0);
2541 name = ggc_strdup (label);
2542 symbol = gen_rtx_SYMBOL_REF (Pmode, name);
2543 SYMBOL_REF_FLAGS (symbol) = SYMBOL_FLAG_LOCAL;
2545 initial_trampoline = gen_rtx_MEM (BLKmode, symbol);
2546 set_mem_align (initial_trampoline, TRAMPOLINE_ALIGNMENT);
2548 return initial_trampoline;
2550 #endif
2552 /* A and B are either alignments or offsets. Return the minimum alignment
2553 that may be assumed after adding the two together. */
2555 static inline unsigned
2556 min_align (unsigned int a, unsigned int b)
2558 return (a | b) & -(a | b);
2561 /* Return the assembler directive for creating a given kind of integer
2562 object. SIZE is the number of bytes in the object and ALIGNED_P
2563 indicates whether it is known to be aligned. Return NULL if the
2564 assembly dialect has no such directive.
2566 The returned string should be printed at the start of a new line and
2567 be followed immediately by the object's initial value. */
2569 const char *
2570 integer_asm_op (int size, int aligned_p)
2572 struct asm_int_op *ops;
2574 if (aligned_p)
2575 ops = &targetm.asm_out.aligned_op;
2576 else
2577 ops = &targetm.asm_out.unaligned_op;
2579 switch (size)
2581 case 1:
2582 return targetm.asm_out.byte_op;
2583 case 2:
2584 return ops->hi;
2585 case 4:
2586 return ops->si;
2587 case 8:
2588 return ops->di;
2589 case 16:
2590 return ops->ti;
2591 default:
2592 return NULL;
2596 /* Use directive OP to assemble an integer object X. Print OP at the
2597 start of the line, followed immediately by the value of X. */
2599 void
2600 assemble_integer_with_op (const char *op, rtx x)
2602 fputs (op, asm_out_file);
2603 output_addr_const (asm_out_file, x);
2604 fputc ('\n', asm_out_file);
2607 /* The default implementation of the asm_out.integer target hook. */
2609 bool
2610 default_assemble_integer (rtx x ATTRIBUTE_UNUSED,
2611 unsigned int size ATTRIBUTE_UNUSED,
2612 int aligned_p ATTRIBUTE_UNUSED)
2614 const char *op = integer_asm_op (size, aligned_p);
2615 /* Avoid GAS bugs for large values. Specifically negative values whose
2616 absolute value fits in a bfd_vma, but not in a bfd_signed_vma. */
2617 if (size > UNITS_PER_WORD && size > POINTER_SIZE / BITS_PER_UNIT)
2618 return false;
2619 return op && (assemble_integer_with_op (op, x), true);
2622 /* Assemble the integer constant X into an object of SIZE bytes. ALIGN is
2623 the alignment of the integer in bits. Return 1 if we were able to output
2624 the constant, otherwise 0. We must be able to output the constant,
2625 if FORCE is nonzero. */
2627 bool
2628 assemble_integer (rtx x, unsigned int size, unsigned int align, int force)
2630 int aligned_p;
2632 aligned_p = (align >= MIN (size * BITS_PER_UNIT, BIGGEST_ALIGNMENT));
2634 /* See if the target hook can handle this kind of object. */
2635 if (targetm.asm_out.integer (x, size, aligned_p))
2636 return true;
2638 /* If the object is a multi-byte one, try splitting it up. Split
2639 it into words it if is multi-word, otherwise split it into bytes. */
2640 if (size > 1)
2642 enum machine_mode omode, imode;
2643 unsigned int subalign;
2644 unsigned int subsize, i;
2645 enum mode_class mclass;
2647 subsize = size > UNITS_PER_WORD? UNITS_PER_WORD : 1;
2648 subalign = MIN (align, subsize * BITS_PER_UNIT);
2649 if (GET_CODE (x) == CONST_FIXED)
2650 mclass = GET_MODE_CLASS (GET_MODE (x));
2651 else
2652 mclass = MODE_INT;
2654 omode = mode_for_size (subsize * BITS_PER_UNIT, mclass, 0);
2655 imode = mode_for_size (size * BITS_PER_UNIT, mclass, 0);
2657 for (i = 0; i < size; i += subsize)
2659 rtx partial = simplify_subreg (omode, x, imode, i);
2660 if (!partial || !assemble_integer (partial, subsize, subalign, 0))
2661 break;
2663 if (i == size)
2664 return true;
2666 /* If we've printed some of it, but not all of it, there's no going
2667 back now. */
2668 gcc_assert (!i);
2671 gcc_assert (!force);
2673 return false;
2676 void
2677 assemble_real (REAL_VALUE_TYPE d, enum machine_mode mode, unsigned int align)
2679 long data[4] = {0, 0, 0, 0};
2680 int i;
2681 int bitsize, nelts, nunits, units_per;
2683 /* This is hairy. We have a quantity of known size. real_to_target
2684 will put it into an array of *host* longs, 32 bits per element
2685 (even if long is more than 32 bits). We need to determine the
2686 number of array elements that are occupied (nelts) and the number
2687 of *target* min-addressable units that will be occupied in the
2688 object file (nunits). We cannot assume that 32 divides the
2689 mode's bitsize (size * BITS_PER_UNIT) evenly.
2691 size * BITS_PER_UNIT is used here to make sure that padding bits
2692 (which might appear at either end of the value; real_to_target
2693 will include the padding bits in its output array) are included. */
2695 nunits = GET_MODE_SIZE (mode);
2696 bitsize = nunits * BITS_PER_UNIT;
2697 nelts = CEIL (bitsize, 32);
2698 units_per = 32 / BITS_PER_UNIT;
2700 real_to_target (data, &d, mode);
2702 /* Put out the first word with the specified alignment. */
2703 assemble_integer (GEN_INT (data[0]), MIN (nunits, units_per), align, 1);
2704 nunits -= units_per;
2706 /* Subsequent words need only 32-bit alignment. */
2707 align = min_align (align, 32);
2709 for (i = 1; i < nelts; i++)
2711 assemble_integer (GEN_INT (data[i]), MIN (nunits, units_per), align, 1);
2712 nunits -= units_per;
2716 /* Given an expression EXP with a constant value,
2717 reduce it to the sum of an assembler symbol and an integer.
2718 Store them both in the structure *VALUE.
2719 EXP must be reducible. */
2721 struct GTY(()) addr_const {
2722 rtx base;
2723 HOST_WIDE_INT offset;
2726 static void
2727 decode_addr_const (tree exp, struct addr_const *value)
2729 tree target = TREE_OPERAND (exp, 0);
2730 int offset = 0;
2731 rtx x;
2733 while (1)
2735 if (TREE_CODE (target) == COMPONENT_REF
2736 && host_integerp (byte_position (TREE_OPERAND (target, 1)), 0))
2739 offset += int_byte_position (TREE_OPERAND (target, 1));
2740 target = TREE_OPERAND (target, 0);
2742 else if (TREE_CODE (target) == ARRAY_REF
2743 || TREE_CODE (target) == ARRAY_RANGE_REF)
2745 offset += (tree_low_cst (TYPE_SIZE_UNIT (TREE_TYPE (target)), 1)
2746 * tree_low_cst (TREE_OPERAND (target, 1), 0));
2747 target = TREE_OPERAND (target, 0);
2749 else
2750 break;
2753 switch (TREE_CODE (target))
2755 case VAR_DECL:
2756 case FUNCTION_DECL:
2757 x = DECL_RTL (target);
2758 break;
2760 case LABEL_DECL:
2761 x = gen_rtx_MEM (FUNCTION_MODE,
2762 gen_rtx_LABEL_REF (Pmode, force_label_rtx (target)));
2763 break;
2765 case REAL_CST:
2766 case FIXED_CST:
2767 case STRING_CST:
2768 case COMPLEX_CST:
2769 case CONSTRUCTOR:
2770 case INTEGER_CST:
2771 x = output_constant_def (target, 1);
2772 break;
2774 default:
2775 gcc_unreachable ();
2778 gcc_assert (MEM_P (x));
2779 x = XEXP (x, 0);
2781 value->base = x;
2782 value->offset = offset;
2785 /* Uniquize all constants that appear in memory.
2786 Each constant in memory thus far output is recorded
2787 in `const_desc_table'. */
2789 struct GTY(()) constant_descriptor_tree {
2790 /* A MEM for the constant. */
2791 rtx rtl;
2793 /* The value of the constant. */
2794 tree value;
2796 /* Hash of value. Computing the hash from value each time
2797 hashfn is called can't work properly, as that means recursive
2798 use of the hash table during hash table expansion. */
2799 hashval_t hash;
2802 static GTY((param_is (struct constant_descriptor_tree)))
2803 htab_t const_desc_htab;
2805 static struct constant_descriptor_tree * build_constant_desc (tree);
2806 static void maybe_output_constant_def_contents (struct constant_descriptor_tree *, int);
2808 /* Compute a hash code for a constant expression. */
2810 static hashval_t
2811 const_desc_hash (const void *ptr)
2813 return ((const struct constant_descriptor_tree *)ptr)->hash;
2816 static hashval_t
2817 const_hash_1 (const tree exp)
2819 const char *p;
2820 hashval_t hi;
2821 int len, i;
2822 enum tree_code code = TREE_CODE (exp);
2824 /* Either set P and LEN to the address and len of something to hash and
2825 exit the switch or return a value. */
2827 switch (code)
2829 case INTEGER_CST:
2830 p = (char *) &TREE_INT_CST (exp);
2831 len = sizeof TREE_INT_CST (exp);
2832 break;
2834 case REAL_CST:
2835 return real_hash (TREE_REAL_CST_PTR (exp));
2837 case FIXED_CST:
2838 return fixed_hash (TREE_FIXED_CST_PTR (exp));
2840 case STRING_CST:
2841 p = TREE_STRING_POINTER (exp);
2842 len = TREE_STRING_LENGTH (exp);
2843 break;
2845 case COMPLEX_CST:
2846 return (const_hash_1 (TREE_REALPART (exp)) * 5
2847 + const_hash_1 (TREE_IMAGPART (exp)));
2849 case CONSTRUCTOR:
2851 unsigned HOST_WIDE_INT idx;
2852 tree value;
2854 hi = 5 + int_size_in_bytes (TREE_TYPE (exp));
2856 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (exp), idx, value)
2857 if (value)
2858 hi = hi * 603 + const_hash_1 (value);
2860 return hi;
2863 case ADDR_EXPR:
2864 case FDESC_EXPR:
2866 struct addr_const value;
2868 decode_addr_const (exp, &value);
2869 switch (GET_CODE (value.base))
2871 case SYMBOL_REF:
2872 /* Don't hash the address of the SYMBOL_REF;
2873 only use the offset and the symbol name. */
2874 hi = value.offset;
2875 p = XSTR (value.base, 0);
2876 for (i = 0; p[i] != 0; i++)
2877 hi = ((hi * 613) + (unsigned) (p[i]));
2878 break;
2880 case LABEL_REF:
2881 hi = value.offset + CODE_LABEL_NUMBER (XEXP (value.base, 0)) * 13;
2882 break;
2884 default:
2885 gcc_unreachable ();
2888 return hi;
2890 case PLUS_EXPR:
2891 case POINTER_PLUS_EXPR:
2892 case MINUS_EXPR:
2893 return (const_hash_1 (TREE_OPERAND (exp, 0)) * 9
2894 + const_hash_1 (TREE_OPERAND (exp, 1)));
2896 CASE_CONVERT:
2897 return const_hash_1 (TREE_OPERAND (exp, 0)) * 7 + 2;
2899 default:
2900 /* A language specific constant. Just hash the code. */
2901 return code;
2904 /* Compute hashing function. */
2905 hi = len;
2906 for (i = 0; i < len; i++)
2907 hi = ((hi * 613) + (unsigned) (p[i]));
2909 return hi;
2912 /* Wrapper of compare_constant, for the htab interface. */
2913 static int
2914 const_desc_eq (const void *p1, const void *p2)
2916 const struct constant_descriptor_tree *const c1
2917 = (const struct constant_descriptor_tree *) p1;
2918 const struct constant_descriptor_tree *const c2
2919 = (const struct constant_descriptor_tree *) p2;
2920 if (c1->hash != c2->hash)
2921 return 0;
2922 return compare_constant (c1->value, c2->value);
2925 /* Compare t1 and t2, and return 1 only if they are known to result in
2926 the same bit pattern on output. */
2928 static int
2929 compare_constant (const tree t1, const tree t2)
2931 enum tree_code typecode;
2933 if (t1 == NULL_TREE)
2934 return t2 == NULL_TREE;
2935 if (t2 == NULL_TREE)
2936 return 0;
2938 if (TREE_CODE (t1) != TREE_CODE (t2))
2939 return 0;
2941 switch (TREE_CODE (t1))
2943 case INTEGER_CST:
2944 /* Integer constants are the same only if the same width of type. */
2945 if (TYPE_PRECISION (TREE_TYPE (t1)) != TYPE_PRECISION (TREE_TYPE (t2)))
2946 return 0;
2947 if (TYPE_MODE (TREE_TYPE (t1)) != TYPE_MODE (TREE_TYPE (t2)))
2948 return 0;
2949 return tree_int_cst_equal (t1, t2);
2951 case REAL_CST:
2952 /* Real 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 REAL_VALUES_IDENTICAL (TREE_REAL_CST (t1), TREE_REAL_CST (t2));
2958 case FIXED_CST:
2959 /* Fixed constants are the same only if the same width of type. */
2960 if (TYPE_PRECISION (TREE_TYPE (t1)) != TYPE_PRECISION (TREE_TYPE (t2)))
2961 return 0;
2963 return FIXED_VALUES_IDENTICAL (TREE_FIXED_CST (t1), TREE_FIXED_CST (t2));
2965 case STRING_CST:
2966 if (TYPE_MODE (TREE_TYPE (t1)) != TYPE_MODE (TREE_TYPE (t2)))
2967 return 0;
2969 return (TREE_STRING_LENGTH (t1) == TREE_STRING_LENGTH (t2)
2970 && ! memcmp (TREE_STRING_POINTER (t1), TREE_STRING_POINTER (t2),
2971 TREE_STRING_LENGTH (t1)));
2973 case COMPLEX_CST:
2974 return (compare_constant (TREE_REALPART (t1), TREE_REALPART (t2))
2975 && compare_constant (TREE_IMAGPART (t1), TREE_IMAGPART (t2)));
2977 case CONSTRUCTOR:
2979 VEC(constructor_elt, gc) *v1, *v2;
2980 unsigned HOST_WIDE_INT idx;
2982 typecode = TREE_CODE (TREE_TYPE (t1));
2983 if (typecode != TREE_CODE (TREE_TYPE (t2)))
2984 return 0;
2986 if (typecode == ARRAY_TYPE)
2988 HOST_WIDE_INT size_1 = int_size_in_bytes (TREE_TYPE (t1));
2989 /* For arrays, check that the sizes all match. */
2990 if (TYPE_MODE (TREE_TYPE (t1)) != TYPE_MODE (TREE_TYPE (t2))
2991 || size_1 == -1
2992 || size_1 != int_size_in_bytes (TREE_TYPE (t2)))
2993 return 0;
2995 else
2997 /* For record and union constructors, require exact type
2998 equality. */
2999 if (TREE_TYPE (t1) != TREE_TYPE (t2))
3000 return 0;
3003 v1 = CONSTRUCTOR_ELTS (t1);
3004 v2 = CONSTRUCTOR_ELTS (t2);
3005 if (VEC_length (constructor_elt, v1)
3006 != VEC_length (constructor_elt, v2))
3007 return 0;
3009 for (idx = 0; idx < VEC_length (constructor_elt, v1); ++idx)
3011 constructor_elt *c1 = VEC_index (constructor_elt, v1, idx);
3012 constructor_elt *c2 = VEC_index (constructor_elt, v2, idx);
3014 /* Check that each value is the same... */
3015 if (!compare_constant (c1->value, c2->value))
3016 return 0;
3017 /* ... and that they apply to the same fields! */
3018 if (typecode == ARRAY_TYPE)
3020 if (!compare_constant (c1->index, c2->index))
3021 return 0;
3023 else
3025 if (c1->index != c2->index)
3026 return 0;
3030 return 1;
3033 case ADDR_EXPR:
3034 case FDESC_EXPR:
3036 struct addr_const value1, value2;
3038 decode_addr_const (t1, &value1);
3039 decode_addr_const (t2, &value2);
3040 return (value1.offset == value2.offset
3041 && strcmp (XSTR (value1.base, 0), XSTR (value2.base, 0)) == 0);
3044 case PLUS_EXPR:
3045 case POINTER_PLUS_EXPR:
3046 case MINUS_EXPR:
3047 case RANGE_EXPR:
3048 return (compare_constant (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0))
3049 && compare_constant(TREE_OPERAND (t1, 1), TREE_OPERAND (t2, 1)));
3051 CASE_CONVERT:
3052 case VIEW_CONVERT_EXPR:
3053 return compare_constant (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
3055 default:
3056 return 0;
3059 gcc_unreachable ();
3062 /* Make a copy of the whole tree structure for a constant. This
3063 handles the same types of nodes that compare_constant handles. */
3065 static tree
3066 copy_constant (tree exp)
3068 switch (TREE_CODE (exp))
3070 case ADDR_EXPR:
3071 /* For ADDR_EXPR, we do not want to copy the decl whose address
3072 is requested. We do want to copy constants though. */
3073 if (CONSTANT_CLASS_P (TREE_OPERAND (exp, 0)))
3074 return build1 (TREE_CODE (exp), TREE_TYPE (exp),
3075 copy_constant (TREE_OPERAND (exp, 0)));
3076 else
3077 return copy_node (exp);
3079 case INTEGER_CST:
3080 case REAL_CST:
3081 case FIXED_CST:
3082 case STRING_CST:
3083 return copy_node (exp);
3085 case COMPLEX_CST:
3086 return build_complex (TREE_TYPE (exp),
3087 copy_constant (TREE_REALPART (exp)),
3088 copy_constant (TREE_IMAGPART (exp)));
3090 case PLUS_EXPR:
3091 case POINTER_PLUS_EXPR:
3092 case MINUS_EXPR:
3093 return build2 (TREE_CODE (exp), TREE_TYPE (exp),
3094 copy_constant (TREE_OPERAND (exp, 0)),
3095 copy_constant (TREE_OPERAND (exp, 1)));
3097 CASE_CONVERT:
3098 case VIEW_CONVERT_EXPR:
3099 return build1 (TREE_CODE (exp), TREE_TYPE (exp),
3100 copy_constant (TREE_OPERAND (exp, 0)));
3102 case CONSTRUCTOR:
3104 tree copy = copy_node (exp);
3105 VEC(constructor_elt, gc) *v;
3106 unsigned HOST_WIDE_INT idx;
3107 tree purpose, value;
3109 v = VEC_alloc(constructor_elt, gc, VEC_length(constructor_elt,
3110 CONSTRUCTOR_ELTS (exp)));
3111 FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (exp), idx, purpose, value)
3113 constructor_elt *ce = VEC_quick_push (constructor_elt, v, NULL);
3114 ce->index = purpose;
3115 ce->value = copy_constant (value);
3117 CONSTRUCTOR_ELTS (copy) = v;
3118 return copy;
3121 default:
3122 gcc_unreachable ();
3126 /* Return the alignment of constant EXP in bits. */
3128 static unsigned int
3129 get_constant_alignment (tree exp)
3131 unsigned int align;
3133 align = TYPE_ALIGN (TREE_TYPE (exp));
3134 #ifdef CONSTANT_ALIGNMENT
3135 align = CONSTANT_ALIGNMENT (exp, align);
3136 #endif
3137 return align;
3140 /* Return the section into which constant EXP should be placed. */
3142 static section *
3143 get_constant_section (tree exp)
3145 if (IN_NAMED_SECTION (exp))
3146 return get_named_section (exp, NULL, compute_reloc_for_constant (exp));
3147 else
3148 return targetm.asm_out.select_section (exp,
3149 compute_reloc_for_constant (exp),
3150 get_constant_alignment (exp));
3153 /* Return the size of constant EXP in bytes. */
3155 static HOST_WIDE_INT
3156 get_constant_size (tree exp)
3158 HOST_WIDE_INT size;
3160 size = int_size_in_bytes (TREE_TYPE (exp));
3161 if (TREE_CODE (exp) == STRING_CST)
3162 size = MAX (TREE_STRING_LENGTH (exp), size);
3163 return size;
3166 /* Subroutine of output_constant_def:
3167 No constant equal to EXP is known to have been output.
3168 Make a constant descriptor to enter EXP in the hash table.
3169 Assign the label number and construct RTL to refer to the
3170 constant's location in memory.
3171 Caller is responsible for updating the hash table. */
3173 static struct constant_descriptor_tree *
3174 build_constant_desc (tree exp)
3176 rtx symbol;
3177 rtx rtl;
3178 char label[256];
3179 int labelno;
3180 struct constant_descriptor_tree *desc;
3182 desc = GGC_NEW (struct constant_descriptor_tree);
3183 desc->value = copy_constant (exp);
3185 /* Propagate marked-ness to copied constant. */
3186 if (flag_mudflap && mf_marked_p (exp))
3187 mf_mark (desc->value);
3189 /* Create a string containing the label name, in LABEL. */
3190 labelno = const_labelno++;
3191 ASM_GENERATE_INTERNAL_LABEL (label, "LC", labelno);
3193 /* We have a symbol name; construct the SYMBOL_REF and the MEM. */
3194 if (use_object_blocks_p ())
3196 section *sect = get_constant_section (exp);
3197 symbol = create_block_symbol (ggc_strdup (label),
3198 get_block_for_section (sect), -1);
3200 else
3201 symbol = gen_rtx_SYMBOL_REF (Pmode, ggc_strdup (label));
3202 SYMBOL_REF_FLAGS (symbol) |= SYMBOL_FLAG_LOCAL;
3203 SET_SYMBOL_REF_DECL (symbol, desc->value);
3204 TREE_CONSTANT_POOL_ADDRESS_P (symbol) = 1;
3206 rtl = gen_rtx_MEM (TYPE_MODE (TREE_TYPE (exp)), symbol);
3207 set_mem_attributes (rtl, exp, 1);
3208 set_mem_alias_set (rtl, 0);
3209 set_mem_alias_set (rtl, const_alias_set);
3211 /* Set flags or add text to the name to record information, such as
3212 that it is a local symbol. If the name is changed, the macro
3213 ASM_OUTPUT_LABELREF will have to know how to strip this
3214 information. This call might invalidate our local variable
3215 SYMBOL; we can't use it afterward. */
3217 targetm.encode_section_info (exp, rtl, true);
3219 desc->rtl = rtl;
3221 return desc;
3224 /* Return an rtx representing a reference to constant data in memory
3225 for the constant expression EXP.
3227 If assembler code for such a constant has already been output,
3228 return an rtx to refer to it.
3229 Otherwise, output such a constant in memory
3230 and generate an rtx for it.
3232 If DEFER is nonzero, this constant can be deferred and output only
3233 if referenced in the function after all optimizations.
3235 `const_desc_table' records which constants already have label strings. */
3238 output_constant_def (tree exp, int defer)
3240 struct constant_descriptor_tree *desc;
3241 struct constant_descriptor_tree key;
3242 void **loc;
3244 /* Look up EXP in the table of constant descriptors. If we didn't find
3245 it, create a new one. */
3246 key.value = exp;
3247 key.hash = const_hash_1 (exp);
3248 loc = htab_find_slot_with_hash (const_desc_htab, &key, key.hash, INSERT);
3250 desc = (struct constant_descriptor_tree *) *loc;
3251 if (desc == 0)
3253 desc = build_constant_desc (exp);
3254 desc->hash = key.hash;
3255 *loc = desc;
3258 maybe_output_constant_def_contents (desc, defer);
3259 return desc->rtl;
3262 /* Subroutine of output_constant_def: Decide whether or not we need to
3263 output the constant DESC now, and if so, do it. */
3264 static void
3265 maybe_output_constant_def_contents (struct constant_descriptor_tree *desc,
3266 int defer)
3268 rtx symbol = XEXP (desc->rtl, 0);
3269 tree exp = desc->value;
3271 if (flag_syntax_only)
3272 return;
3274 if (TREE_ASM_WRITTEN (exp))
3275 /* Already output; don't do it again. */
3276 return;
3278 /* We can always defer constants as long as the context allows
3279 doing so. */
3280 if (defer)
3282 /* Increment n_deferred_constants if it exists. It needs to be at
3283 least as large as the number of constants actually referred to
3284 by the function. If it's too small we'll stop looking too early
3285 and fail to emit constants; if it's too large we'll only look
3286 through the entire function when we could have stopped earlier. */
3287 if (cfun)
3288 n_deferred_constants++;
3289 return;
3292 output_constant_def_contents (symbol);
3295 /* Subroutine of output_constant_def_contents. Output the definition
3296 of constant EXP, which is pointed to by label LABEL. ALIGN is the
3297 constant's alignment in bits. */
3299 static void
3300 assemble_constant_contents (tree exp, const char *label, unsigned int align)
3302 HOST_WIDE_INT size;
3304 size = get_constant_size (exp);
3306 /* Do any machine/system dependent processing of the constant. */
3307 #ifdef ASM_DECLARE_CONSTANT_NAME
3308 ASM_DECLARE_CONSTANT_NAME (asm_out_file, label, exp, size);
3309 #else
3310 /* Standard thing is just output label for the constant. */
3311 ASM_OUTPUT_LABEL (asm_out_file, label);
3312 #endif /* ASM_DECLARE_CONSTANT_NAME */
3314 /* Output the value of EXP. */
3315 output_constant (exp, size, align);
3318 /* We must output the constant data referred to by SYMBOL; do so. */
3320 static void
3321 output_constant_def_contents (rtx symbol)
3323 tree exp = SYMBOL_REF_DECL (symbol);
3324 unsigned int align;
3326 /* Make sure any other constants whose addresses appear in EXP
3327 are assigned label numbers. */
3328 output_addressed_constants (exp);
3330 /* We are no longer deferring this constant. */
3331 TREE_ASM_WRITTEN (exp) = 1;
3333 /* If the constant is part of an object block, make sure that the
3334 decl has been positioned within its block, but do not write out
3335 its definition yet. output_object_blocks will do that later. */
3336 if (SYMBOL_REF_HAS_BLOCK_INFO_P (symbol) && SYMBOL_REF_BLOCK (symbol))
3337 place_block_symbol (symbol);
3338 else
3340 switch_to_section (get_constant_section (exp));
3341 align = get_constant_alignment (exp);
3342 if (align > BITS_PER_UNIT)
3343 ASM_OUTPUT_ALIGN (asm_out_file, floor_log2 (align / BITS_PER_UNIT));
3344 assemble_constant_contents (exp, XSTR (symbol, 0), align);
3346 if (flag_mudflap)
3347 mudflap_enqueue_constant (exp);
3350 /* Look up EXP in the table of constant descriptors. Return the rtl
3351 if it has been emitted, else null. */
3354 lookup_constant_def (tree exp)
3356 struct constant_descriptor_tree *desc;
3357 struct constant_descriptor_tree key;
3359 key.value = exp;
3360 key.hash = const_hash_1 (exp);
3361 desc = (struct constant_descriptor_tree *)
3362 htab_find_with_hash (const_desc_htab, &key, key.hash);
3364 return (desc ? desc->rtl : NULL_RTX);
3367 /* Used in the hash tables to avoid outputting the same constant
3368 twice. Unlike 'struct constant_descriptor_tree', RTX constants
3369 are output once per function, not once per file. */
3370 /* ??? Only a few targets need per-function constant pools. Most
3371 can use one per-file pool. Should add a targetm bit to tell the
3372 difference. */
3374 struct GTY(()) rtx_constant_pool {
3375 /* Pointers to first and last constant in pool, as ordered by offset. */
3376 struct constant_descriptor_rtx *first;
3377 struct constant_descriptor_rtx *last;
3379 /* Hash facility for making memory-constants from constant rtl-expressions.
3380 It is used on RISC machines where immediate integer arguments and
3381 constant addresses are restricted so that such constants must be stored
3382 in memory. */
3383 htab_t GTY((param_is (struct constant_descriptor_rtx))) const_rtx_htab;
3385 /* Current offset in constant pool (does not include any
3386 machine-specific header). */
3387 HOST_WIDE_INT offset;
3390 struct GTY((chain_next ("%h.next"))) constant_descriptor_rtx {
3391 struct constant_descriptor_rtx *next;
3392 rtx mem;
3393 rtx sym;
3394 rtx constant;
3395 HOST_WIDE_INT offset;
3396 hashval_t hash;
3397 enum machine_mode mode;
3398 unsigned int align;
3399 int labelno;
3400 int mark;
3403 /* Hash and compare functions for const_rtx_htab. */
3405 static hashval_t
3406 const_desc_rtx_hash (const void *ptr)
3408 const struct constant_descriptor_rtx *const desc
3409 = (const struct constant_descriptor_rtx *) ptr;
3410 return desc->hash;
3413 static int
3414 const_desc_rtx_eq (const void *a, const void *b)
3416 const struct constant_descriptor_rtx *const x
3417 = (const struct constant_descriptor_rtx *) a;
3418 const struct constant_descriptor_rtx *const y
3419 = (const struct constant_descriptor_rtx *) b;
3421 if (x->mode != y->mode)
3422 return 0;
3423 return rtx_equal_p (x->constant, y->constant);
3426 /* This is the worker function for const_rtx_hash, called via for_each_rtx. */
3428 static int
3429 const_rtx_hash_1 (rtx *xp, void *data)
3431 unsigned HOST_WIDE_INT hwi;
3432 enum machine_mode mode;
3433 enum rtx_code code;
3434 hashval_t h, *hp;
3435 rtx x;
3437 x = *xp;
3438 code = GET_CODE (x);
3439 mode = GET_MODE (x);
3440 h = (hashval_t) code * 1048573 + mode;
3442 switch (code)
3444 case CONST_INT:
3445 hwi = INTVAL (x);
3446 fold_hwi:
3448 int shift = sizeof (hashval_t) * CHAR_BIT;
3449 const int n = sizeof (HOST_WIDE_INT) / sizeof (hashval_t);
3450 int i;
3452 h ^= (hashval_t) hwi;
3453 for (i = 1; i < n; ++i)
3455 hwi >>= shift;
3456 h ^= (hashval_t) hwi;
3459 break;
3461 case CONST_DOUBLE:
3462 if (mode == VOIDmode)
3464 hwi = CONST_DOUBLE_LOW (x) ^ CONST_DOUBLE_HIGH (x);
3465 goto fold_hwi;
3467 else
3468 h ^= real_hash (CONST_DOUBLE_REAL_VALUE (x));
3469 break;
3471 case CONST_FIXED:
3472 h ^= fixed_hash (CONST_FIXED_VALUE (x));
3473 break;
3475 case CONST_VECTOR:
3477 int i;
3478 for (i = XVECLEN (x, 0); i-- > 0; )
3479 h = h * 251 + const_rtx_hash_1 (&XVECEXP (x, 0, i), data);
3481 break;
3483 case SYMBOL_REF:
3484 h ^= htab_hash_string (XSTR (x, 0));
3485 break;
3487 case LABEL_REF:
3488 h = h * 251 + CODE_LABEL_NUMBER (XEXP (x, 0));
3489 break;
3491 case UNSPEC:
3492 case UNSPEC_VOLATILE:
3493 h = h * 251 + XINT (x, 1);
3494 break;
3496 default:
3497 break;
3500 hp = (hashval_t *) data;
3501 *hp = *hp * 509 + h;
3502 return 0;
3505 /* Compute a hash value for X, which should be a constant. */
3507 static hashval_t
3508 const_rtx_hash (rtx x)
3510 hashval_t h = 0;
3511 for_each_rtx (&x, const_rtx_hash_1, &h);
3512 return h;
3516 /* Create and return a new rtx constant pool. */
3518 static struct rtx_constant_pool *
3519 create_constant_pool (void)
3521 struct rtx_constant_pool *pool;
3523 pool = GGC_NEW (struct rtx_constant_pool);
3524 pool->const_rtx_htab = htab_create_ggc (31, const_desc_rtx_hash,
3525 const_desc_rtx_eq, NULL);
3526 pool->first = NULL;
3527 pool->last = NULL;
3528 pool->offset = 0;
3529 return pool;
3532 /* Initialize constant pool hashing for a new function. */
3534 void
3535 init_varasm_status (void)
3537 crtl->varasm.pool = create_constant_pool ();
3538 crtl->varasm.deferred_constants = 0;
3541 /* Given a MINUS expression, simplify it if both sides
3542 include the same symbol. */
3545 simplify_subtraction (rtx x)
3547 rtx r = simplify_rtx (x);
3548 return r ? r : x;
3551 /* Given a constant rtx X, make (or find) a memory constant for its value
3552 and return a MEM rtx to refer to it in memory. */
3555 force_const_mem (enum machine_mode mode, rtx x)
3557 struct constant_descriptor_rtx *desc, tmp;
3558 struct rtx_constant_pool *pool;
3559 char label[256];
3560 rtx def, symbol;
3561 hashval_t hash;
3562 unsigned int align;
3563 void **slot;
3565 /* If we're not allowed to drop X into the constant pool, don't. */
3566 if (targetm.cannot_force_const_mem (x))
3567 return NULL_RTX;
3569 /* Record that this function has used a constant pool entry. */
3570 crtl->uses_const_pool = 1;
3572 /* Decide which pool to use. */
3573 pool = (targetm.use_blocks_for_constant_p (mode, x)
3574 ? shared_constant_pool
3575 : crtl->varasm.pool);
3577 /* Lookup the value in the hashtable. */
3578 tmp.constant = x;
3579 tmp.mode = mode;
3580 hash = const_rtx_hash (x);
3581 slot = htab_find_slot_with_hash (pool->const_rtx_htab, &tmp, hash, INSERT);
3582 desc = (struct constant_descriptor_rtx *) *slot;
3584 /* If the constant was already present, return its memory. */
3585 if (desc)
3586 return copy_rtx (desc->mem);
3588 /* Otherwise, create a new descriptor. */
3589 desc = GGC_NEW (struct constant_descriptor_rtx);
3590 *slot = desc;
3592 /* Align the location counter as required by EXP's data type. */
3593 align = GET_MODE_ALIGNMENT (mode == VOIDmode ? word_mode : mode);
3594 #ifdef CONSTANT_ALIGNMENT
3596 tree type = lang_hooks.types.type_for_mode (mode, 0);
3597 if (type != NULL_TREE)
3598 align = CONSTANT_ALIGNMENT (make_tree (type, x), align);
3600 #endif
3602 pool->offset += (align / BITS_PER_UNIT) - 1;
3603 pool->offset &= ~ ((align / BITS_PER_UNIT) - 1);
3605 desc->next = NULL;
3606 desc->constant = tmp.constant;
3607 desc->offset = pool->offset;
3608 desc->hash = hash;
3609 desc->mode = mode;
3610 desc->align = align;
3611 desc->labelno = const_labelno;
3612 desc->mark = 0;
3614 pool->offset += GET_MODE_SIZE (mode);
3615 if (pool->last)
3616 pool->last->next = desc;
3617 else
3618 pool->first = pool->last = desc;
3619 pool->last = desc;
3621 /* Create a string containing the label name, in LABEL. */
3622 ASM_GENERATE_INTERNAL_LABEL (label, "LC", const_labelno);
3623 ++const_labelno;
3625 /* Construct the SYMBOL_REF. Make sure to mark it as belonging to
3626 the constants pool. */
3627 if (use_object_blocks_p () && targetm.use_blocks_for_constant_p (mode, x))
3629 section *sect = targetm.asm_out.select_rtx_section (mode, x, align);
3630 symbol = create_block_symbol (ggc_strdup (label),
3631 get_block_for_section (sect), -1);
3633 else
3634 symbol = gen_rtx_SYMBOL_REF (Pmode, ggc_strdup (label));
3635 desc->sym = symbol;
3636 SYMBOL_REF_FLAGS (symbol) |= SYMBOL_FLAG_LOCAL;
3637 CONSTANT_POOL_ADDRESS_P (symbol) = 1;
3638 SET_SYMBOL_REF_CONSTANT (symbol, desc);
3640 /* Construct the MEM. */
3641 desc->mem = def = gen_const_mem (mode, symbol);
3642 set_mem_attributes (def, lang_hooks.types.type_for_mode (mode, 0), 1);
3643 set_mem_align (def, align);
3645 /* If we're dropping a label to the constant pool, make sure we
3646 don't delete it. */
3647 if (GET_CODE (x) == LABEL_REF)
3648 LABEL_PRESERVE_P (XEXP (x, 0)) = 1;
3650 return copy_rtx (def);
3653 /* Given a constant pool SYMBOL_REF, return the corresponding constant. */
3656 get_pool_constant (rtx addr)
3658 return SYMBOL_REF_CONSTANT (addr)->constant;
3661 /* Given a constant pool SYMBOL_REF, return the corresponding constant
3662 and whether it has been output or not. */
3665 get_pool_constant_mark (rtx addr, bool *pmarked)
3667 struct constant_descriptor_rtx *desc;
3669 desc = SYMBOL_REF_CONSTANT (addr);
3670 *pmarked = (desc->mark != 0);
3671 return desc->constant;
3674 /* Similar, return the mode. */
3676 enum machine_mode
3677 get_pool_mode (const_rtx addr)
3679 return SYMBOL_REF_CONSTANT (addr)->mode;
3682 /* Return the size of the constant pool. */
3685 get_pool_size (void)
3687 return crtl->varasm.pool->offset;
3690 /* Worker function for output_constant_pool_1. Emit assembly for X
3691 in MODE with known alignment ALIGN. */
3693 static void
3694 output_constant_pool_2 (enum machine_mode mode, rtx x, unsigned int align)
3696 switch (GET_MODE_CLASS (mode))
3698 case MODE_FLOAT:
3699 case MODE_DECIMAL_FLOAT:
3701 REAL_VALUE_TYPE r;
3703 gcc_assert (GET_CODE (x) == CONST_DOUBLE);
3704 REAL_VALUE_FROM_CONST_DOUBLE (r, x);
3705 assemble_real (r, mode, align);
3706 break;
3709 case MODE_INT:
3710 case MODE_PARTIAL_INT:
3711 case MODE_FRACT:
3712 case MODE_UFRACT:
3713 case MODE_ACCUM:
3714 case MODE_UACCUM:
3715 assemble_integer (x, GET_MODE_SIZE (mode), align, 1);
3716 break;
3718 case MODE_VECTOR_FLOAT:
3719 case MODE_VECTOR_INT:
3720 case MODE_VECTOR_FRACT:
3721 case MODE_VECTOR_UFRACT:
3722 case MODE_VECTOR_ACCUM:
3723 case MODE_VECTOR_UACCUM:
3725 int i, units;
3726 enum machine_mode submode = GET_MODE_INNER (mode);
3727 unsigned int subalign = MIN (align, GET_MODE_BITSIZE (submode));
3729 gcc_assert (GET_CODE (x) == CONST_VECTOR);
3730 units = CONST_VECTOR_NUNITS (x);
3732 for (i = 0; i < units; i++)
3734 rtx elt = CONST_VECTOR_ELT (x, i);
3735 output_constant_pool_2 (submode, elt, i ? subalign : align);
3738 break;
3740 default:
3741 gcc_unreachable ();
3745 /* Worker function for output_constant_pool. Emit constant DESC,
3746 giving it ALIGN bits of alignment. */
3748 static void
3749 output_constant_pool_1 (struct constant_descriptor_rtx *desc,
3750 unsigned int align)
3752 rtx x, tmp;
3754 x = desc->constant;
3756 /* See if X is a LABEL_REF (or a CONST referring to a LABEL_REF)
3757 whose CODE_LABEL has been deleted. This can occur if a jump table
3758 is eliminated by optimization. If so, write a constant of zero
3759 instead. Note that this can also happen by turning the
3760 CODE_LABEL into a NOTE. */
3761 /* ??? This seems completely and utterly wrong. Certainly it's
3762 not true for NOTE_INSN_DELETED_LABEL, but I disbelieve proper
3763 functioning even with INSN_DELETED_P and friends. */
3765 tmp = x;
3766 switch (GET_CODE (tmp))
3768 case CONST:
3769 if (GET_CODE (XEXP (tmp, 0)) != PLUS
3770 || GET_CODE (XEXP (XEXP (tmp, 0), 0)) != LABEL_REF)
3771 break;
3772 tmp = XEXP (XEXP (tmp, 0), 0);
3773 /* FALLTHRU */
3775 case LABEL_REF:
3776 tmp = XEXP (tmp, 0);
3777 gcc_assert (!INSN_DELETED_P (tmp));
3778 gcc_assert (!NOTE_P (tmp)
3779 || NOTE_KIND (tmp) != NOTE_INSN_DELETED);
3780 break;
3782 default:
3783 break;
3786 #ifdef ASM_OUTPUT_SPECIAL_POOL_ENTRY
3787 ASM_OUTPUT_SPECIAL_POOL_ENTRY (asm_out_file, x, desc->mode,
3788 align, desc->labelno, done);
3789 #endif
3791 assemble_align (align);
3793 /* Output the label. */
3794 targetm.asm_out.internal_label (asm_out_file, "LC", desc->labelno);
3796 /* Output the data. */
3797 output_constant_pool_2 (desc->mode, x, align);
3799 /* Make sure all constants in SECTION_MERGE and not SECTION_STRINGS
3800 sections have proper size. */
3801 if (align > GET_MODE_BITSIZE (desc->mode)
3802 && in_section
3803 && (in_section->common.flags & SECTION_MERGE))
3804 assemble_align (align);
3806 #ifdef ASM_OUTPUT_SPECIAL_POOL_ENTRY
3807 done:
3808 #endif
3809 return;
3812 /* Given a SYMBOL_REF CURRENT_RTX, mark it and all constants it refers
3813 to as used. Emit referenced deferred strings. This function can
3814 be used with for_each_rtx to mark all SYMBOL_REFs in an rtx. */
3816 static int
3817 mark_constant (rtx *current_rtx, void *data ATTRIBUTE_UNUSED)
3819 rtx x = *current_rtx;
3821 if (x == NULL_RTX || GET_CODE (x) != SYMBOL_REF)
3822 return 0;
3824 if (CONSTANT_POOL_ADDRESS_P (x))
3826 struct constant_descriptor_rtx *desc = SYMBOL_REF_CONSTANT (x);
3827 if (desc->mark == 0)
3829 desc->mark = 1;
3830 for_each_rtx (&desc->constant, mark_constant, NULL);
3833 else if (TREE_CONSTANT_POOL_ADDRESS_P (x))
3835 tree exp = SYMBOL_REF_DECL (x);
3836 if (!TREE_ASM_WRITTEN (exp))
3838 n_deferred_constants--;
3839 output_constant_def_contents (x);
3843 return -1;
3846 /* Look through appropriate parts of INSN, marking all entries in the
3847 constant pool which are actually being used. Entries that are only
3848 referenced by other constants are also marked as used. Emit
3849 deferred strings that are used. */
3851 static void
3852 mark_constants (rtx insn)
3854 if (!INSN_P (insn))
3855 return;
3857 /* Insns may appear inside a SEQUENCE. Only check the patterns of
3858 insns, not any notes that may be attached. We don't want to mark
3859 a constant just because it happens to appear in a REG_EQUIV note. */
3860 if (GET_CODE (PATTERN (insn)) == SEQUENCE)
3862 rtx seq = PATTERN (insn);
3863 int i, n = XVECLEN (seq, 0);
3864 for (i = 0; i < n; ++i)
3866 rtx subinsn = XVECEXP (seq, 0, i);
3867 if (INSN_P (subinsn))
3868 for_each_rtx (&PATTERN (subinsn), mark_constant, NULL);
3871 else
3872 for_each_rtx (&PATTERN (insn), mark_constant, NULL);
3875 /* Look through the instructions for this function, and mark all the
3876 entries in POOL which are actually being used. Emit deferred constants
3877 which have indeed been used. */
3879 static void
3880 mark_constant_pool (void)
3882 rtx insn, link;
3884 if (!crtl->uses_const_pool && n_deferred_constants == 0)
3885 return;
3887 for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
3888 mark_constants (insn);
3890 for (link = crtl->epilogue_delay_list;
3891 link;
3892 link = XEXP (link, 1))
3893 mark_constants (XEXP (link, 0));
3896 /* Write all the constants in POOL. */
3898 static void
3899 output_constant_pool_contents (struct rtx_constant_pool *pool)
3901 struct constant_descriptor_rtx *desc;
3903 for (desc = pool->first; desc ; desc = desc->next)
3904 if (desc->mark)
3906 /* If the constant is part of an object_block, make sure that
3907 the constant has been positioned within its block, but do not
3908 write out its definition yet. output_object_blocks will do
3909 that later. */
3910 if (SYMBOL_REF_HAS_BLOCK_INFO_P (desc->sym)
3911 && SYMBOL_REF_BLOCK (desc->sym))
3912 place_block_symbol (desc->sym);
3913 else
3915 switch_to_section (targetm.asm_out.select_rtx_section
3916 (desc->mode, desc->constant, desc->align));
3917 output_constant_pool_1 (desc, desc->align);
3922 /* Mark all constants that are used in the current function, then write
3923 out the function's private constant pool. */
3925 static void
3926 output_constant_pool (const char *fnname ATTRIBUTE_UNUSED,
3927 tree fndecl ATTRIBUTE_UNUSED)
3929 struct rtx_constant_pool *pool = crtl->varasm.pool;
3931 /* It is possible for gcc to call force_const_mem and then to later
3932 discard the instructions which refer to the constant. In such a
3933 case we do not need to output the constant. */
3934 mark_constant_pool ();
3936 #ifdef ASM_OUTPUT_POOL_PROLOGUE
3937 ASM_OUTPUT_POOL_PROLOGUE (asm_out_file, fnname, fndecl, pool->offset);
3938 #endif
3940 output_constant_pool_contents (pool);
3942 #ifdef ASM_OUTPUT_POOL_EPILOGUE
3943 ASM_OUTPUT_POOL_EPILOGUE (asm_out_file, fnname, fndecl, pool->offset);
3944 #endif
3947 /* Write the contents of the shared constant pool. */
3949 void
3950 output_shared_constant_pool (void)
3952 output_constant_pool_contents (shared_constant_pool);
3955 /* Determine what kind of relocations EXP may need. */
3958 compute_reloc_for_constant (tree exp)
3960 int reloc = 0, reloc2;
3961 tree tem;
3963 switch (TREE_CODE (exp))
3965 case ADDR_EXPR:
3966 case FDESC_EXPR:
3967 /* Go inside any operations that get_inner_reference can handle and see
3968 if what's inside is a constant: no need to do anything here for
3969 addresses of variables or functions. */
3970 for (tem = TREE_OPERAND (exp, 0); handled_component_p (tem);
3971 tem = TREE_OPERAND (tem, 0))
3974 if (TREE_PUBLIC (tem))
3975 reloc |= 2;
3976 else
3977 reloc |= 1;
3978 break;
3980 case PLUS_EXPR:
3981 case POINTER_PLUS_EXPR:
3982 reloc = compute_reloc_for_constant (TREE_OPERAND (exp, 0));
3983 reloc |= compute_reloc_for_constant (TREE_OPERAND (exp, 1));
3984 break;
3986 case MINUS_EXPR:
3987 reloc = compute_reloc_for_constant (TREE_OPERAND (exp, 0));
3988 reloc2 = compute_reloc_for_constant (TREE_OPERAND (exp, 1));
3989 /* The difference of two local labels is computable at link time. */
3990 if (reloc == 1 && reloc2 == 1)
3991 reloc = 0;
3992 else
3993 reloc |= reloc2;
3994 break;
3996 CASE_CONVERT:
3997 case VIEW_CONVERT_EXPR:
3998 reloc = compute_reloc_for_constant (TREE_OPERAND (exp, 0));
3999 break;
4001 case CONSTRUCTOR:
4003 unsigned HOST_WIDE_INT idx;
4004 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (exp), idx, tem)
4005 if (tem != 0)
4006 reloc |= compute_reloc_for_constant (tem);
4008 break;
4010 default:
4011 break;
4013 return reloc;
4016 /* Find all the constants whose addresses are referenced inside of EXP,
4017 and make sure assembler code with a label has been output for each one.
4018 Indicate whether an ADDR_EXPR has been encountered. */
4020 static void
4021 output_addressed_constants (tree exp)
4023 tree tem;
4025 switch (TREE_CODE (exp))
4027 case ADDR_EXPR:
4028 case FDESC_EXPR:
4029 /* Go inside any operations that get_inner_reference can handle and see
4030 if what's inside is a constant: no need to do anything here for
4031 addresses of variables or functions. */
4032 for (tem = TREE_OPERAND (exp, 0); handled_component_p (tem);
4033 tem = TREE_OPERAND (tem, 0))
4036 /* If we have an initialized CONST_DECL, retrieve the initializer. */
4037 if (TREE_CODE (tem) == CONST_DECL && DECL_INITIAL (tem))
4038 tem = DECL_INITIAL (tem);
4040 if (CONSTANT_CLASS_P (tem) || TREE_CODE (tem) == CONSTRUCTOR)
4041 output_constant_def (tem, 0);
4042 break;
4044 case PLUS_EXPR:
4045 case POINTER_PLUS_EXPR:
4046 case MINUS_EXPR:
4047 output_addressed_constants (TREE_OPERAND (exp, 1));
4048 /* Fall through. */
4050 CASE_CONVERT:
4051 case VIEW_CONVERT_EXPR:
4052 output_addressed_constants (TREE_OPERAND (exp, 0));
4053 break;
4055 case CONSTRUCTOR:
4057 unsigned HOST_WIDE_INT idx;
4058 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (exp), idx, tem)
4059 if (tem != 0)
4060 output_addressed_constants (tem);
4062 break;
4064 default:
4065 break;
4069 /* Whether a constructor CTOR is a valid static constant initializer if all
4070 its elements are. This used to be internal to initializer_constant_valid_p
4071 and has been exposed to let other functions like categorize_ctor_elements
4072 evaluate the property while walking a constructor for other purposes. */
4074 bool
4075 constructor_static_from_elts_p (const_tree ctor)
4077 return (TREE_CONSTANT (ctor)
4078 && (TREE_CODE (TREE_TYPE (ctor)) == UNION_TYPE
4079 || TREE_CODE (TREE_TYPE (ctor)) == RECORD_TYPE)
4080 && !VEC_empty (constructor_elt, CONSTRUCTOR_ELTS (ctor)));
4083 /* A subroutine of initializer_constant_valid_p. VALUE is a MINUS_EXPR,
4084 PLUS_EXPR or POINTER_PLUS_EXPR. This looks for cases of VALUE
4085 which are valid when ENDTYPE is an integer of any size; in
4086 particular, this does not accept a pointer minus a constant. This
4087 returns null_pointer_node if the VALUE is an absolute constant
4088 which can be used to initialize a static variable. Otherwise it
4089 returns NULL. */
4091 static tree
4092 narrowing_initializer_constant_valid_p (tree value, tree endtype)
4094 tree op0, op1;
4096 if (!INTEGRAL_TYPE_P (endtype))
4097 return NULL_TREE;
4099 op0 = TREE_OPERAND (value, 0);
4100 op1 = TREE_OPERAND (value, 1);
4102 /* Like STRIP_NOPS except allow the operand mode to widen. This
4103 works around a feature of fold that simplifies (int)(p1 - p2) to
4104 ((int)p1 - (int)p2) under the theory that the narrower operation
4105 is cheaper. */
4107 while (CONVERT_EXPR_P (op0)
4108 || TREE_CODE (op0) == NON_LVALUE_EXPR)
4110 tree inner = TREE_OPERAND (op0, 0);
4111 if (inner == error_mark_node
4112 || ! INTEGRAL_MODE_P (TYPE_MODE (TREE_TYPE (inner)))
4113 || (GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op0)))
4114 > GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (inner)))))
4115 break;
4116 op0 = inner;
4119 while (CONVERT_EXPR_P (op1)
4120 || TREE_CODE (op1) == NON_LVALUE_EXPR)
4122 tree inner = TREE_OPERAND (op1, 0);
4123 if (inner == error_mark_node
4124 || ! INTEGRAL_MODE_P (TYPE_MODE (TREE_TYPE (inner)))
4125 || (GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op1)))
4126 > GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (inner)))))
4127 break;
4128 op1 = inner;
4131 op0 = initializer_constant_valid_p (op0, endtype);
4132 op1 = initializer_constant_valid_p (op1, endtype);
4134 /* Both initializers must be known. */
4135 if (op0 && op1)
4137 if (op0 == op1
4138 && (op0 == null_pointer_node
4139 || TREE_CODE (value) == MINUS_EXPR))
4140 return null_pointer_node;
4142 /* Support differences between labels. */
4143 if (TREE_CODE (op0) == LABEL_DECL
4144 && TREE_CODE (op1) == LABEL_DECL)
4145 return null_pointer_node;
4147 if (TREE_CODE (op0) == STRING_CST
4148 && TREE_CODE (op1) == STRING_CST
4149 && operand_equal_p (op0, op1, 1))
4150 return null_pointer_node;
4153 return NULL_TREE;
4156 /* Return nonzero if VALUE is a valid constant-valued expression
4157 for use in initializing a static variable; one that can be an
4158 element of a "constant" initializer.
4160 Return null_pointer_node if the value is absolute;
4161 if it is relocatable, return the variable that determines the relocation.
4162 We assume that VALUE has been folded as much as possible;
4163 therefore, we do not need to check for such things as
4164 arithmetic-combinations of integers. */
4166 tree
4167 initializer_constant_valid_p (tree value, tree endtype)
4169 tree ret;
4171 switch (TREE_CODE (value))
4173 case CONSTRUCTOR:
4174 if (constructor_static_from_elts_p (value))
4176 unsigned HOST_WIDE_INT idx;
4177 tree elt;
4178 bool absolute = true;
4180 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (value), idx, elt)
4182 tree reloc;
4183 reloc = initializer_constant_valid_p (elt, TREE_TYPE (elt));
4184 if (!reloc)
4185 return NULL_TREE;
4186 if (reloc != null_pointer_node)
4187 absolute = false;
4189 /* For a non-absolute relocation, there is no single
4190 variable that can be "the variable that determines the
4191 relocation." */
4192 return absolute ? null_pointer_node : error_mark_node;
4195 return TREE_STATIC (value) ? null_pointer_node : NULL_TREE;
4197 case INTEGER_CST:
4198 case VECTOR_CST:
4199 case REAL_CST:
4200 case FIXED_CST:
4201 case STRING_CST:
4202 case COMPLEX_CST:
4203 return null_pointer_node;
4205 case ADDR_EXPR:
4206 case FDESC_EXPR:
4208 tree op0 = staticp (TREE_OPERAND (value, 0));
4209 if (op0)
4211 /* "&(*a).f" is like unto pointer arithmetic. If "a" turns out
4212 to be a constant, this is old-skool offsetof-like nonsense. */
4213 if (TREE_CODE (op0) == INDIRECT_REF
4214 && TREE_CONSTANT (TREE_OPERAND (op0, 0)))
4215 return null_pointer_node;
4216 /* Taking the address of a nested function involves a trampoline,
4217 unless we don't need or want one. */
4218 if (TREE_CODE (op0) == FUNCTION_DECL
4219 && decl_function_context (op0)
4220 && !DECL_NO_STATIC_CHAIN (op0)
4221 && !TREE_NO_TRAMPOLINE (value))
4222 return NULL_TREE;
4223 /* "&{...}" requires a temporary to hold the constructed
4224 object. */
4225 if (TREE_CODE (op0) == CONSTRUCTOR)
4226 return NULL_TREE;
4228 return op0;
4231 case NON_LVALUE_EXPR:
4232 return initializer_constant_valid_p (TREE_OPERAND (value, 0), endtype);
4234 case VIEW_CONVERT_EXPR:
4236 tree src = TREE_OPERAND (value, 0);
4237 tree src_type = TREE_TYPE (src);
4238 tree dest_type = TREE_TYPE (value);
4240 /* Allow view-conversions from aggregate to non-aggregate type only
4241 if the bit pattern is fully preserved afterwards; otherwise, the
4242 RTL expander won't be able to apply a subsequent transformation
4243 to the underlying constructor. */
4244 if (AGGREGATE_TYPE_P (src_type) && !AGGREGATE_TYPE_P (dest_type))
4246 if (TYPE_MODE (endtype) == TYPE_MODE (dest_type))
4247 return initializer_constant_valid_p (src, endtype);
4248 else
4249 return NULL_TREE;
4252 /* Allow all other kinds of view-conversion. */
4253 return initializer_constant_valid_p (src, endtype);
4256 CASE_CONVERT:
4258 tree src = TREE_OPERAND (value, 0);
4259 tree src_type = TREE_TYPE (src);
4260 tree dest_type = TREE_TYPE (value);
4262 /* Allow conversions between pointer types, floating-point
4263 types, and offset types. */
4264 if ((POINTER_TYPE_P (dest_type) && POINTER_TYPE_P (src_type))
4265 || (FLOAT_TYPE_P (dest_type) && FLOAT_TYPE_P (src_type))
4266 || (TREE_CODE (dest_type) == OFFSET_TYPE
4267 && TREE_CODE (src_type) == OFFSET_TYPE))
4268 return initializer_constant_valid_p (src, endtype);
4270 /* Allow length-preserving conversions between integer types. */
4271 if (INTEGRAL_TYPE_P (dest_type) && INTEGRAL_TYPE_P (src_type)
4272 && (TYPE_PRECISION (dest_type) == TYPE_PRECISION (src_type)))
4273 return initializer_constant_valid_p (src, endtype);
4275 /* Allow conversions between other integer types only if
4276 explicit value. */
4277 if (INTEGRAL_TYPE_P (dest_type) && INTEGRAL_TYPE_P (src_type))
4279 tree inner = initializer_constant_valid_p (src, endtype);
4280 if (inner == null_pointer_node)
4281 return null_pointer_node;
4282 break;
4285 /* Allow (int) &foo provided int is as wide as a pointer. */
4286 if (INTEGRAL_TYPE_P (dest_type) && POINTER_TYPE_P (src_type)
4287 && (TYPE_PRECISION (dest_type) >= TYPE_PRECISION (src_type)))
4288 return initializer_constant_valid_p (src, endtype);
4290 /* Likewise conversions from int to pointers, but also allow
4291 conversions from 0. */
4292 if ((POINTER_TYPE_P (dest_type)
4293 || TREE_CODE (dest_type) == OFFSET_TYPE)
4294 && INTEGRAL_TYPE_P (src_type))
4296 if (TREE_CODE (src) == INTEGER_CST
4297 && TYPE_PRECISION (dest_type) >= TYPE_PRECISION (src_type))
4298 return null_pointer_node;
4299 if (integer_zerop (src))
4300 return null_pointer_node;
4301 else if (TYPE_PRECISION (dest_type) <= TYPE_PRECISION (src_type))
4302 return initializer_constant_valid_p (src, endtype);
4305 /* Allow conversions to struct or union types if the value
4306 inside is okay. */
4307 if (TREE_CODE (dest_type) == RECORD_TYPE
4308 || TREE_CODE (dest_type) == UNION_TYPE)
4309 return initializer_constant_valid_p (src, endtype);
4311 break;
4313 case POINTER_PLUS_EXPR:
4314 case PLUS_EXPR:
4315 if (! INTEGRAL_TYPE_P (endtype)
4316 || TYPE_PRECISION (endtype) >= POINTER_SIZE)
4318 tree valid0 = initializer_constant_valid_p (TREE_OPERAND (value, 0),
4319 endtype);
4320 tree valid1 = initializer_constant_valid_p (TREE_OPERAND (value, 1),
4321 endtype);
4322 /* If either term is absolute, use the other term's relocation. */
4323 if (valid0 == null_pointer_node)
4324 return valid1;
4325 if (valid1 == null_pointer_node)
4326 return valid0;
4329 /* Support narrowing pointer differences. */
4330 ret = narrowing_initializer_constant_valid_p (value, endtype);
4331 if (ret != NULL_TREE)
4332 return ret;
4334 break;
4336 case MINUS_EXPR:
4337 if (! INTEGRAL_TYPE_P (endtype)
4338 || TYPE_PRECISION (endtype) >= POINTER_SIZE)
4340 tree valid0 = initializer_constant_valid_p (TREE_OPERAND (value, 0),
4341 endtype);
4342 tree valid1 = initializer_constant_valid_p (TREE_OPERAND (value, 1),
4343 endtype);
4344 /* Win if second argument is absolute. */
4345 if (valid1 == null_pointer_node)
4346 return valid0;
4347 /* Win if both arguments have the same relocation.
4348 Then the value is absolute. */
4349 if (valid0 == valid1 && valid0 != 0)
4350 return null_pointer_node;
4352 /* Since GCC guarantees that string constants are unique in the
4353 generated code, a subtraction between two copies of the same
4354 constant string is absolute. */
4355 if (valid0 && TREE_CODE (valid0) == STRING_CST
4356 && valid1 && TREE_CODE (valid1) == STRING_CST
4357 && operand_equal_p (valid0, valid1, 1))
4358 return null_pointer_node;
4361 /* Support narrowing differences. */
4362 ret = narrowing_initializer_constant_valid_p (value, endtype);
4363 if (ret != NULL_TREE)
4364 return ret;
4366 break;
4368 default:
4369 break;
4372 return 0;
4375 /* Return true if VALUE is a valid constant-valued expression
4376 for use in initializing a static bit-field; one that can be
4377 an element of a "constant" initializer. */
4379 bool
4380 initializer_constant_valid_for_bitfield_p (tree value)
4382 /* For bitfields we support integer constants or possibly nested aggregates
4383 of such. */
4384 switch (TREE_CODE (value))
4386 case CONSTRUCTOR:
4388 unsigned HOST_WIDE_INT idx;
4389 tree elt;
4391 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (value), idx, elt)
4392 if (!initializer_constant_valid_for_bitfield_p (elt))
4393 return false;
4394 return true;
4397 case INTEGER_CST:
4398 return true;
4400 case VIEW_CONVERT_EXPR:
4401 case NON_LVALUE_EXPR:
4402 return
4403 initializer_constant_valid_for_bitfield_p (TREE_OPERAND (value, 0));
4405 default:
4406 break;
4409 return false;
4412 /* output_constructor outer state of relevance in recursive calls, typically
4413 for nested aggregate bitfields. */
4415 typedef struct {
4416 unsigned int bit_offset; /* current position in ... */
4417 int byte; /* ... the outer byte buffer. */
4418 } oc_outer_state;
4420 static unsigned HOST_WIDE_INT
4421 output_constructor (tree, unsigned HOST_WIDE_INT, unsigned int,
4422 oc_outer_state *);
4424 /* Output assembler code for constant EXP to FILE, with no label.
4425 This includes the pseudo-op such as ".int" or ".byte", and a newline.
4426 Assumes output_addressed_constants has been done on EXP already.
4428 Generate exactly SIZE bytes of assembler data, padding at the end
4429 with zeros if necessary. SIZE must always be specified.
4431 SIZE is important for structure constructors,
4432 since trailing members may have been omitted from the constructor.
4433 It is also important for initialization of arrays from string constants
4434 since the full length of the string constant might not be wanted.
4435 It is also needed for initialization of unions, where the initializer's
4436 type is just one member, and that may not be as long as the union.
4438 There a case in which we would fail to output exactly SIZE bytes:
4439 for a structure constructor that wants to produce more than SIZE bytes.
4440 But such constructors will never be generated for any possible input.
4442 ALIGN is the alignment of the data in bits. */
4444 void
4445 output_constant (tree exp, unsigned HOST_WIDE_INT size, unsigned int align)
4447 enum tree_code code;
4448 unsigned HOST_WIDE_INT thissize;
4450 if (size == 0 || flag_syntax_only)
4451 return;
4453 /* See if we're trying to initialize a pointer in a non-default mode
4454 to the address of some declaration somewhere. If the target says
4455 the mode is valid for pointers, assume the target has a way of
4456 resolving it. */
4457 if (TREE_CODE (exp) == NOP_EXPR
4458 && POINTER_TYPE_P (TREE_TYPE (exp))
4459 && targetm.valid_pointer_mode (TYPE_MODE (TREE_TYPE (exp))))
4461 tree saved_type = TREE_TYPE (exp);
4463 /* Peel off any intermediate conversions-to-pointer for valid
4464 pointer modes. */
4465 while (TREE_CODE (exp) == NOP_EXPR
4466 && POINTER_TYPE_P (TREE_TYPE (exp))
4467 && targetm.valid_pointer_mode (TYPE_MODE (TREE_TYPE (exp))))
4468 exp = TREE_OPERAND (exp, 0);
4470 /* If what we're left with is the address of something, we can
4471 convert the address to the final type and output it that
4472 way. */
4473 if (TREE_CODE (exp) == ADDR_EXPR)
4474 exp = build1 (ADDR_EXPR, saved_type, TREE_OPERAND (exp, 0));
4475 /* Likewise for constant ints. */
4476 else if (TREE_CODE (exp) == INTEGER_CST)
4477 exp = build_int_cst_wide (saved_type, TREE_INT_CST_LOW (exp),
4478 TREE_INT_CST_HIGH (exp));
4482 /* Eliminate any conversions since we'll be outputting the underlying
4483 constant. */
4484 while (CONVERT_EXPR_P (exp)
4485 || TREE_CODE (exp) == NON_LVALUE_EXPR
4486 || TREE_CODE (exp) == VIEW_CONVERT_EXPR)
4488 HOST_WIDE_INT type_size = int_size_in_bytes (TREE_TYPE (exp));
4489 HOST_WIDE_INT op_size = int_size_in_bytes (TREE_TYPE (TREE_OPERAND (exp, 0)));
4491 /* Make sure eliminating the conversion is really a no-op, except with
4492 VIEW_CONVERT_EXPRs to allow for wild Ada unchecked conversions and
4493 union types to allow for Ada unchecked unions. */
4494 if (type_size > op_size
4495 && TREE_CODE (exp) != VIEW_CONVERT_EXPR
4496 && TREE_CODE (TREE_TYPE (exp)) != UNION_TYPE)
4497 /* Keep the conversion. */
4498 break;
4499 else
4500 exp = TREE_OPERAND (exp, 0);
4503 code = TREE_CODE (TREE_TYPE (exp));
4504 thissize = int_size_in_bytes (TREE_TYPE (exp));
4506 /* Allow a constructor with no elements for any data type.
4507 This means to fill the space with zeros. */
4508 if (TREE_CODE (exp) == CONSTRUCTOR
4509 && VEC_empty (constructor_elt, CONSTRUCTOR_ELTS (exp)))
4511 assemble_zeros (size);
4512 return;
4515 if (TREE_CODE (exp) == FDESC_EXPR)
4517 #ifdef ASM_OUTPUT_FDESC
4518 HOST_WIDE_INT part = tree_low_cst (TREE_OPERAND (exp, 1), 0);
4519 tree decl = TREE_OPERAND (exp, 0);
4520 ASM_OUTPUT_FDESC (asm_out_file, decl, part);
4521 #else
4522 gcc_unreachable ();
4523 #endif
4524 return;
4527 /* Now output the underlying data. If we've handling the padding, return.
4528 Otherwise, break and ensure SIZE is the size written. */
4529 switch (code)
4531 case BOOLEAN_TYPE:
4532 case INTEGER_TYPE:
4533 case ENUMERAL_TYPE:
4534 case POINTER_TYPE:
4535 case REFERENCE_TYPE:
4536 case OFFSET_TYPE:
4537 case FIXED_POINT_TYPE:
4538 if (! assemble_integer (expand_expr (exp, NULL_RTX, VOIDmode,
4539 EXPAND_INITIALIZER),
4540 MIN (size, thissize), align, 0))
4541 error ("initializer for integer/fixed-point value is too complicated");
4542 break;
4544 case REAL_TYPE:
4545 if (TREE_CODE (exp) != REAL_CST)
4546 error ("initializer for floating value is not a floating constant");
4548 assemble_real (TREE_REAL_CST (exp), TYPE_MODE (TREE_TYPE (exp)), align);
4549 break;
4551 case COMPLEX_TYPE:
4552 output_constant (TREE_REALPART (exp), thissize / 2, align);
4553 output_constant (TREE_IMAGPART (exp), thissize / 2,
4554 min_align (align, BITS_PER_UNIT * (thissize / 2)));
4555 break;
4557 case ARRAY_TYPE:
4558 case VECTOR_TYPE:
4559 switch (TREE_CODE (exp))
4561 case CONSTRUCTOR:
4562 output_constructor (exp, size, align, NULL);
4563 return;
4564 case STRING_CST:
4565 thissize = MIN ((unsigned HOST_WIDE_INT)TREE_STRING_LENGTH (exp),
4566 size);
4567 assemble_string (TREE_STRING_POINTER (exp), thissize);
4568 break;
4570 case VECTOR_CST:
4572 int elt_size;
4573 tree link;
4574 unsigned int nalign;
4575 enum machine_mode inner;
4577 inner = TYPE_MODE (TREE_TYPE (TREE_TYPE (exp)));
4578 nalign = MIN (align, GET_MODE_ALIGNMENT (inner));
4580 elt_size = GET_MODE_SIZE (inner);
4582 link = TREE_VECTOR_CST_ELTS (exp);
4583 output_constant (TREE_VALUE (link), elt_size, align);
4584 thissize = elt_size;
4585 while ((link = TREE_CHAIN (link)) != NULL)
4587 output_constant (TREE_VALUE (link), elt_size, nalign);
4588 thissize += elt_size;
4590 break;
4592 default:
4593 gcc_unreachable ();
4595 break;
4597 case RECORD_TYPE:
4598 case UNION_TYPE:
4599 gcc_assert (TREE_CODE (exp) == CONSTRUCTOR);
4600 output_constructor (exp, size, align, NULL);
4601 return;
4603 case ERROR_MARK:
4604 return;
4606 default:
4607 gcc_unreachable ();
4610 if (size > thissize)
4611 assemble_zeros (size - thissize);
4615 /* Subroutine of output_constructor, used for computing the size of
4616 arrays of unspecified length. VAL must be a CONSTRUCTOR of an array
4617 type with an unspecified upper bound. */
4619 static unsigned HOST_WIDE_INT
4620 array_size_for_constructor (tree val)
4622 tree max_index, i;
4623 unsigned HOST_WIDE_INT cnt;
4624 tree index, value, tmp;
4626 /* This code used to attempt to handle string constants that are not
4627 arrays of single-bytes, but nothing else does, so there's no point in
4628 doing it here. */
4629 if (TREE_CODE (val) == STRING_CST)
4630 return TREE_STRING_LENGTH (val);
4632 max_index = NULL_TREE;
4633 FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (val), cnt, index, value)
4635 if (TREE_CODE (index) == RANGE_EXPR)
4636 index = TREE_OPERAND (index, 1);
4637 if (max_index == NULL_TREE || tree_int_cst_lt (max_index, index))
4638 max_index = index;
4641 if (max_index == NULL_TREE)
4642 return 0;
4644 /* Compute the total number of array elements. */
4645 tmp = TYPE_MIN_VALUE (TYPE_DOMAIN (TREE_TYPE (val)));
4646 i = size_binop (MINUS_EXPR, fold_convert (sizetype, max_index),
4647 fold_convert (sizetype, tmp));
4648 i = size_binop (PLUS_EXPR, i, build_int_cst (sizetype, 1));
4650 /* Multiply by the array element unit size to find number of bytes. */
4651 i = size_binop (MULT_EXPR, i, TYPE_SIZE_UNIT (TREE_TYPE (TREE_TYPE (val))));
4653 return tree_low_cst (i, 1);
4656 /* Other datastructures + helpers for output_constructor. */
4658 /* output_constructor local state to support interaction with helpers. */
4660 typedef struct {
4662 /* Received arguments. */
4663 tree exp; /* Constructor expression. */
4664 unsigned HOST_WIDE_INT size; /* # bytes to output - pad if necessary. */
4665 unsigned int align; /* Known initial alignment. */
4667 /* Constructor expression data. */
4668 tree type; /* Expression type. */
4669 tree field; /* Current field decl in a record. */
4670 tree min_index; /* Lower bound if specified for an array. */
4672 /* Output processing state. */
4673 HOST_WIDE_INT total_bytes; /* # bytes output so far / current position. */
4674 bool byte_buffer_in_use; /* Whether byte ... */
4675 int byte; /* ... contains part of a bitfield byte yet to
4676 be output. */
4678 int last_relative_index; /* Implicit or explicit index of the last
4679 array element output within a bitfield. */
4680 /* Current element. */
4681 tree val; /* Current element value. */
4682 tree index; /* Current element index. */
4684 } oc_local_state;
4686 /* Helper for output_constructor. From the current LOCAL state, output a
4687 RANGE_EXPR element. */
4689 static void
4690 output_constructor_array_range (oc_local_state *local)
4692 unsigned HOST_WIDE_INT fieldsize
4693 = int_size_in_bytes (TREE_TYPE (local->type));
4695 HOST_WIDE_INT lo_index
4696 = tree_low_cst (TREE_OPERAND (local->index, 0), 0);
4697 HOST_WIDE_INT hi_index
4698 = tree_low_cst (TREE_OPERAND (local->index, 1), 0);
4699 HOST_WIDE_INT index;
4701 unsigned int align2
4702 = min_align (local->align, fieldsize * BITS_PER_UNIT);
4704 for (index = lo_index; index <= hi_index; index++)
4706 /* Output the element's initial value. */
4707 if (local->val == NULL_TREE)
4708 assemble_zeros (fieldsize);
4709 else
4710 output_constant (local->val, fieldsize, align2);
4712 /* Count its size. */
4713 local->total_bytes += fieldsize;
4717 /* Helper for output_constructor. From the current LOCAL state, output a
4718 field element that is not true bitfield or part of an outer one. */
4720 static void
4721 output_constructor_regular_field (oc_local_state *local)
4723 /* Field size and position. Since this structure is static, we know the
4724 positions are constant. */
4725 unsigned HOST_WIDE_INT fieldsize;
4726 HOST_WIDE_INT fieldpos;
4728 unsigned int align2;
4730 if (local->index != NULL_TREE)
4731 fieldpos = (tree_low_cst (TYPE_SIZE_UNIT (TREE_TYPE (local->val)), 1)
4732 * ((tree_low_cst (local->index, 0)
4733 - tree_low_cst (local->min_index, 0))));
4734 else if (local->field != NULL_TREE)
4735 fieldpos = int_byte_position (local->field);
4736 else
4737 fieldpos = 0;
4739 /* Output any buffered-up bit-fields preceding this element. */
4740 if (local->byte_buffer_in_use)
4742 assemble_integer (GEN_INT (local->byte), 1, BITS_PER_UNIT, 1);
4743 local->total_bytes++;
4744 local->byte_buffer_in_use = false;
4747 /* Advance to offset of this element.
4748 Note no alignment needed in an array, since that is guaranteed
4749 if each element has the proper size. */
4750 if ((local->field != NULL_TREE || local->index != NULL_TREE)
4751 && fieldpos != local->total_bytes)
4753 gcc_assert (fieldpos >= local->total_bytes);
4754 assemble_zeros (fieldpos - local->total_bytes);
4755 local->total_bytes = fieldpos;
4758 /* Find the alignment of this element. */
4759 align2 = min_align (local->align, BITS_PER_UNIT * fieldpos);
4761 /* Determine size this element should occupy. */
4762 if (local->field)
4764 fieldsize = 0;
4766 /* If this is an array with an unspecified upper bound,
4767 the initializer determines the size. */
4768 /* ??? This ought to only checked if DECL_SIZE_UNIT is NULL,
4769 but we cannot do this until the deprecated support for
4770 initializing zero-length array members is removed. */
4771 if (TREE_CODE (TREE_TYPE (local->field)) == ARRAY_TYPE
4772 && TYPE_DOMAIN (TREE_TYPE (local->field))
4773 && ! TYPE_MAX_VALUE (TYPE_DOMAIN (TREE_TYPE (local->field))))
4775 fieldsize = array_size_for_constructor (local->val);
4776 /* Given a non-empty initialization, this field had
4777 better be last. */
4778 gcc_assert (!fieldsize || !TREE_CHAIN (local->field));
4780 else if (DECL_SIZE_UNIT (local->field))
4782 /* ??? This can't be right. If the decl size overflows
4783 a host integer we will silently emit no data. */
4784 if (host_integerp (DECL_SIZE_UNIT (local->field), 1))
4785 fieldsize = tree_low_cst (DECL_SIZE_UNIT (local->field), 1);
4788 else
4789 fieldsize = int_size_in_bytes (TREE_TYPE (local->type));
4791 /* Output the element's initial value. */
4792 if (local->val == NULL_TREE)
4793 assemble_zeros (fieldsize);
4794 else
4795 output_constant (local->val, fieldsize, align2);
4797 /* Count its size. */
4798 local->total_bytes += fieldsize;
4801 /* Helper for output_constructor. From the current LOCAL and OUTER states,
4802 output an element that is a true bitfield or part of an outer one. */
4804 static void
4805 output_constructor_bitfield (oc_local_state *local, oc_outer_state *outer)
4807 /* Bit size of this element. */
4808 HOST_WIDE_INT ebitsize
4809 = (local->field
4810 ? tree_low_cst (DECL_SIZE (local->field), 1)
4811 : tree_low_cst (TYPE_SIZE (TREE_TYPE (local->type)), 1));
4813 /* Relative index of this element if this is an array component. */
4814 HOST_WIDE_INT relative_index
4815 = (!local->field
4816 ? (local->index
4817 ? (tree_low_cst (local->index, 0)
4818 - tree_low_cst (local->min_index, 0))
4819 : local->last_relative_index + 1)
4820 : 0);
4822 /* Bit position of this element from the start of the containing
4823 constructor. */
4824 HOST_WIDE_INT constructor_relative_ebitpos
4825 = (local->field
4826 ? int_bit_position (local->field)
4827 : ebitsize * relative_index);
4829 /* Bit position of this element from the start of a possibly ongoing
4830 outer byte buffer. */
4831 HOST_WIDE_INT byte_relative_ebitpos
4832 = ((outer ? outer->bit_offset : 0) + constructor_relative_ebitpos);
4834 /* From the start of a possibly ongoing outer byte buffer, offsets to
4835 the first bit of this element and to the first bit past the end of
4836 this element. */
4837 HOST_WIDE_INT next_offset = byte_relative_ebitpos;
4838 HOST_WIDE_INT end_offset = byte_relative_ebitpos + ebitsize;
4840 local->last_relative_index = relative_index;
4842 if (local->val == NULL_TREE)
4843 local->val = integer_zero_node;
4845 while (TREE_CODE (local->val) == VIEW_CONVERT_EXPR
4846 || TREE_CODE (local->val) == NON_LVALUE_EXPR)
4847 local->val = TREE_OPERAND (local->val, 0);
4849 if (TREE_CODE (local->val) != INTEGER_CST
4850 && TREE_CODE (local->val) != CONSTRUCTOR)
4852 error ("invalid initial value for member %qE", DECL_NAME (local->field));
4853 return;
4856 /* If this field does not start in this (or, next) byte,
4857 skip some bytes. */
4858 if (next_offset / BITS_PER_UNIT != local->total_bytes)
4860 /* Output remnant of any bit field in previous bytes. */
4861 if (local->byte_buffer_in_use)
4863 assemble_integer (GEN_INT (local->byte), 1, BITS_PER_UNIT, 1);
4864 local->total_bytes++;
4865 local->byte_buffer_in_use = false;
4868 /* If still not at proper byte, advance to there. */
4869 if (next_offset / BITS_PER_UNIT != local->total_bytes)
4871 gcc_assert (next_offset / BITS_PER_UNIT >= local->total_bytes);
4872 assemble_zeros (next_offset / BITS_PER_UNIT - local->total_bytes);
4873 local->total_bytes = next_offset / BITS_PER_UNIT;
4877 /* Set up the buffer if necessary. */
4878 if (!local->byte_buffer_in_use)
4880 local->byte = 0;
4881 if (ebitsize > 0)
4882 local->byte_buffer_in_use = true;
4885 /* If this is nested constructor, recurse passing the bit offset and the
4886 pending data, then retrieve the new pending data afterwards. */
4887 if (TREE_CODE (local->val) == CONSTRUCTOR)
4889 oc_outer_state output_state;
4891 output_state.bit_offset = next_offset % BITS_PER_UNIT;
4892 output_state.byte = local->byte;
4893 local->total_bytes
4894 += output_constructor (local->val, 0, 0, &output_state);
4895 local->byte = output_state.byte;
4896 return;
4899 /* Otherwise, we must split the element into pieces that fall within
4900 separate bytes, and combine each byte with previous or following
4901 bit-fields. */
4902 while (next_offset < end_offset)
4904 int this_time;
4905 int shift;
4906 HOST_WIDE_INT value;
4907 HOST_WIDE_INT next_byte = next_offset / BITS_PER_UNIT;
4908 HOST_WIDE_INT next_bit = next_offset % BITS_PER_UNIT;
4910 /* Advance from byte to byte
4911 within this element when necessary. */
4912 while (next_byte != local->total_bytes)
4914 assemble_integer (GEN_INT (local->byte), 1, BITS_PER_UNIT, 1);
4915 local->total_bytes++;
4916 local->byte = 0;
4919 /* Number of bits we can process at once
4920 (all part of the same byte). */
4921 this_time = MIN (end_offset - next_offset,
4922 BITS_PER_UNIT - next_bit);
4923 if (BYTES_BIG_ENDIAN)
4925 /* On big-endian machine, take the most significant bits
4926 first (of the bits that are significant)
4927 and put them into bytes from the most significant end. */
4928 shift = end_offset - next_offset - this_time;
4930 /* Don't try to take a bunch of bits that cross
4931 the word boundary in the INTEGER_CST. We can
4932 only select bits from the LOW or HIGH part
4933 not from both. */
4934 if (shift < HOST_BITS_PER_WIDE_INT
4935 && shift + this_time > HOST_BITS_PER_WIDE_INT)
4937 this_time = shift + this_time - HOST_BITS_PER_WIDE_INT;
4938 shift = HOST_BITS_PER_WIDE_INT;
4941 /* Now get the bits from the appropriate constant word. */
4942 if (shift < HOST_BITS_PER_WIDE_INT)
4943 value = TREE_INT_CST_LOW (local->val);
4944 else
4946 gcc_assert (shift < 2 * HOST_BITS_PER_WIDE_INT);
4947 value = TREE_INT_CST_HIGH (local->val);
4948 shift -= HOST_BITS_PER_WIDE_INT;
4951 /* Get the result. This works only when:
4952 1 <= this_time <= HOST_BITS_PER_WIDE_INT. */
4953 local->byte |= (((value >> shift)
4954 & (((HOST_WIDE_INT) 2 << (this_time - 1)) - 1))
4955 << (BITS_PER_UNIT - this_time - next_bit));
4957 else
4959 /* On little-endian machines,
4960 take first the least significant bits of the value
4961 and pack them starting at the least significant
4962 bits of the bytes. */
4963 shift = next_offset - byte_relative_ebitpos;
4965 /* Don't try to take a bunch of bits that cross
4966 the word boundary in the INTEGER_CST. We can
4967 only select bits from the LOW or HIGH part
4968 not from both. */
4969 if (shift < HOST_BITS_PER_WIDE_INT
4970 && shift + this_time > HOST_BITS_PER_WIDE_INT)
4971 this_time = (HOST_BITS_PER_WIDE_INT - shift);
4973 /* Now get the bits from the appropriate constant word. */
4974 if (shift < HOST_BITS_PER_WIDE_INT)
4975 value = TREE_INT_CST_LOW (local->val);
4976 else
4978 gcc_assert (shift < 2 * HOST_BITS_PER_WIDE_INT);
4979 value = TREE_INT_CST_HIGH (local->val);
4980 shift -= HOST_BITS_PER_WIDE_INT;
4983 /* Get the result. This works only when:
4984 1 <= this_time <= HOST_BITS_PER_WIDE_INT. */
4985 local->byte |= (((value >> shift)
4986 & (((HOST_WIDE_INT) 2 << (this_time - 1)) - 1))
4987 << next_bit);
4990 next_offset += this_time;
4991 local->byte_buffer_in_use = true;
4995 /* Subroutine of output_constant, used for CONSTRUCTORs (aggregate constants).
4996 Generate at least SIZE bytes, padding if necessary. OUTER designates the
4997 caller output state of relevance in recursive invocations. */
4999 static unsigned HOST_WIDE_INT
5000 output_constructor (tree exp, unsigned HOST_WIDE_INT size,
5001 unsigned int align, oc_outer_state * outer)
5003 unsigned HOST_WIDE_INT cnt;
5004 constructor_elt *ce;
5006 oc_local_state local;
5008 /* Setup our local state to communicate with helpers. */
5009 local.exp = exp;
5010 local.size = size;
5011 local.align = align;
5013 local.total_bytes = 0;
5014 local.byte_buffer_in_use = outer != NULL;
5015 local.byte = outer ? outer->byte : 0;
5017 local.type = TREE_TYPE (exp);
5019 local.last_relative_index = -1;
5021 local.min_index = NULL_TREE;
5022 if (TREE_CODE (local.type) == ARRAY_TYPE
5023 && TYPE_DOMAIN (local.type) != NULL_TREE)
5024 local.min_index = TYPE_MIN_VALUE (TYPE_DOMAIN (local.type));
5026 gcc_assert (HOST_BITS_PER_WIDE_INT >= BITS_PER_UNIT);
5028 /* As CE goes through the elements of the constant, FIELD goes through the
5029 structure fields if the constant is a structure. If the constant is a
5030 union, we override this by getting the field from the TREE_LIST element.
5031 But the constant could also be an array. Then FIELD is zero.
5033 There is always a maximum of one element in the chain LINK for unions
5034 (even if the initializer in a source program incorrectly contains
5035 more one). */
5037 local.field = NULL_TREE;
5038 if (TREE_CODE (local.type) == RECORD_TYPE)
5039 local.field = TYPE_FIELDS (local.type);
5041 for (cnt = 0;
5042 VEC_iterate (constructor_elt, CONSTRUCTOR_ELTS (exp), cnt, ce);
5043 cnt++, local.field = local.field ? TREE_CHAIN (local.field) : 0)
5045 local.val = ce->value;
5046 local.index = NULL_TREE;
5048 /* The element in a union constructor specifies the proper field
5049 or index. */
5050 if ((TREE_CODE (local.type) == RECORD_TYPE
5051 || TREE_CODE (local.type) == UNION_TYPE
5052 || TREE_CODE (local.type) == QUAL_UNION_TYPE)
5053 && ce->index != NULL_TREE)
5054 local.field = ce->index;
5056 else if (TREE_CODE (local.type) == ARRAY_TYPE)
5057 local.index = ce->index;
5059 #ifdef ASM_COMMENT_START
5060 if (local.field && flag_verbose_asm)
5061 fprintf (asm_out_file, "%s %s:\n",
5062 ASM_COMMENT_START,
5063 DECL_NAME (local.field)
5064 ? IDENTIFIER_POINTER (DECL_NAME (local.field))
5065 : "<anonymous>");
5066 #endif
5068 /* Eliminate the marker that makes a cast not be an lvalue. */
5069 if (local.val != NULL_TREE)
5070 STRIP_NOPS (local.val);
5072 /* Output the current element, using the appropriate helper ... */
5074 /* For an array slice not part of an outer bitfield. */
5075 if (!outer
5076 && local.index != NULL_TREE
5077 && TREE_CODE (local.index) == RANGE_EXPR)
5078 output_constructor_array_range (&local);
5080 /* For a field that is neither a true bitfield nor part of an outer one,
5081 known to be at least byte aligned and multiple-of-bytes long. */
5082 else if (!outer
5083 && (local.field == NULL_TREE
5084 || !CONSTRUCTOR_BITFIELD_P (local.field)))
5085 output_constructor_regular_field (&local);
5087 /* For a true bitfield or part of an outer one. */
5088 else
5089 output_constructor_bitfield (&local, outer);
5092 /* If we are not at toplevel, save the pending data for our caller.
5093 Otherwise output the pending data and padding zeros as needed. */
5094 if (outer)
5095 outer->byte = local.byte;
5096 else
5098 if (local.byte_buffer_in_use)
5100 assemble_integer (GEN_INT (local.byte), 1, BITS_PER_UNIT, 1);
5101 local.total_bytes++;
5104 if ((unsigned HOST_WIDE_INT)local.total_bytes < local.size)
5106 assemble_zeros (local.size - local.total_bytes);
5107 local.total_bytes = local.size;
5111 return local.total_bytes;
5114 /* Mark DECL as weak. */
5116 static void
5117 mark_weak (tree decl)
5119 DECL_WEAK (decl) = 1;
5121 if (DECL_RTL_SET_P (decl)
5122 && MEM_P (DECL_RTL (decl))
5123 && XEXP (DECL_RTL (decl), 0)
5124 && GET_CODE (XEXP (DECL_RTL (decl), 0)) == SYMBOL_REF)
5125 SYMBOL_REF_WEAK (XEXP (DECL_RTL (decl), 0)) = 1;
5128 /* Merge weak status between NEWDECL and OLDDECL. */
5130 void
5131 merge_weak (tree newdecl, tree olddecl)
5133 if (DECL_WEAK (newdecl) == DECL_WEAK (olddecl))
5135 if (DECL_WEAK (newdecl) && SUPPORTS_WEAK)
5137 tree *pwd;
5138 /* We put the NEWDECL on the weak_decls list at some point
5139 and OLDDECL as well. Keep just OLDDECL on the list. */
5140 for (pwd = &weak_decls; *pwd; pwd = &TREE_CHAIN (*pwd))
5141 if (TREE_VALUE (*pwd) == newdecl)
5143 *pwd = TREE_CHAIN (*pwd);
5144 break;
5147 return;
5150 if (DECL_WEAK (newdecl))
5152 tree wd;
5154 /* NEWDECL is weak, but OLDDECL is not. */
5156 /* If we already output the OLDDECL, we're in trouble; we can't
5157 go back and make it weak. This error cannot be caught in
5158 declare_weak because the NEWDECL and OLDDECL was not yet
5159 been merged; therefore, TREE_ASM_WRITTEN was not set. */
5160 if (TREE_ASM_WRITTEN (olddecl))
5161 error ("weak declaration of %q+D must precede definition",
5162 newdecl);
5164 /* If we've already generated rtl referencing OLDDECL, we may
5165 have done so in a way that will not function properly with
5166 a weak symbol. */
5167 else if (TREE_USED (olddecl)
5168 && TREE_SYMBOL_REFERENCED (DECL_ASSEMBLER_NAME (olddecl)))
5169 warning (0, "weak declaration of %q+D after first use results "
5170 "in unspecified behavior", newdecl);
5172 if (SUPPORTS_WEAK)
5174 /* We put the NEWDECL on the weak_decls list at some point.
5175 Replace it with the OLDDECL. */
5176 for (wd = weak_decls; wd; wd = TREE_CHAIN (wd))
5177 if (TREE_VALUE (wd) == newdecl)
5179 TREE_VALUE (wd) = olddecl;
5180 break;
5182 /* We may not find the entry on the list. If NEWDECL is a
5183 weak alias, then we will have already called
5184 globalize_decl to remove the entry; in that case, we do
5185 not need to do anything. */
5188 /* Make the OLDDECL weak; it's OLDDECL that we'll be keeping. */
5189 mark_weak (olddecl);
5191 else
5192 /* OLDDECL was weak, but NEWDECL was not explicitly marked as
5193 weak. Just update NEWDECL to indicate that it's weak too. */
5194 mark_weak (newdecl);
5197 /* Declare DECL to be a weak symbol. */
5199 void
5200 declare_weak (tree decl)
5202 if (! TREE_PUBLIC (decl))
5203 error ("weak declaration of %q+D must be public", decl);
5204 else if (TREE_CODE (decl) == FUNCTION_DECL && TREE_ASM_WRITTEN (decl))
5205 error ("weak declaration of %q+D must precede definition", decl);
5206 else if (!SUPPORTS_WEAK)
5207 warning (0, "weak declaration of %q+D not supported", decl);
5209 mark_weak (decl);
5212 static void
5213 weak_finish_1 (tree decl)
5215 #if defined (ASM_WEAKEN_DECL) || defined (ASM_WEAKEN_LABEL)
5216 const char *const name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
5217 #endif
5219 if (! TREE_USED (decl))
5220 return;
5222 #ifdef ASM_WEAKEN_DECL
5223 ASM_WEAKEN_DECL (asm_out_file, decl, name, NULL);
5224 #else
5225 #ifdef ASM_WEAKEN_LABEL
5226 ASM_WEAKEN_LABEL (asm_out_file, name);
5227 #else
5228 #ifdef ASM_OUTPUT_WEAK_ALIAS
5230 static bool warn_once = 0;
5231 if (! warn_once)
5233 warning (0, "only weak aliases are supported in this configuration");
5234 warn_once = 1;
5236 return;
5238 #endif
5239 #endif
5240 #endif
5243 /* This TREE_LIST contains weakref targets. */
5245 static GTY(()) tree weakref_targets;
5247 /* Forward declaration. */
5248 static tree find_decl_and_mark_needed (tree decl, tree target);
5250 /* Emit any pending weak declarations. */
5252 void
5253 weak_finish (void)
5255 tree t;
5257 for (t = weakref_targets; t; t = TREE_CHAIN (t))
5259 tree alias_decl = TREE_PURPOSE (t);
5260 tree target = ultimate_transparent_alias_target (&TREE_VALUE (t));
5262 if (! TREE_SYMBOL_REFERENCED (DECL_ASSEMBLER_NAME (alias_decl)))
5263 /* Remove alias_decl from the weak list, but leave entries for
5264 the target alone. */
5265 target = NULL_TREE;
5266 #ifndef ASM_OUTPUT_WEAKREF
5267 else if (! TREE_SYMBOL_REFERENCED (target))
5269 /* Use ASM_WEAKEN_LABEL only if ASM_WEAKEN_DECL is not
5270 defined, otherwise we and weak_finish_1 would use
5271 different macros. */
5272 # if defined ASM_WEAKEN_LABEL && ! defined ASM_WEAKEN_DECL
5273 ASM_WEAKEN_LABEL (asm_out_file, IDENTIFIER_POINTER (target));
5274 # else
5275 tree decl = find_decl_and_mark_needed (alias_decl, target);
5277 if (! decl)
5279 decl = build_decl (DECL_SOURCE_LOCATION (alias_decl),
5280 TREE_CODE (alias_decl), target,
5281 TREE_TYPE (alias_decl));
5283 DECL_EXTERNAL (decl) = 1;
5284 TREE_PUBLIC (decl) = 1;
5285 DECL_ARTIFICIAL (decl) = 1;
5286 TREE_NOTHROW (decl) = TREE_NOTHROW (alias_decl);
5287 TREE_USED (decl) = 1;
5290 weak_finish_1 (decl);
5291 # endif
5293 #endif
5296 tree *p;
5297 tree t2;
5299 /* Remove the alias and the target from the pending weak list
5300 so that we do not emit any .weak directives for the former,
5301 nor multiple .weak directives for the latter. */
5302 for (p = &weak_decls; (t2 = *p) ; )
5304 if (TREE_VALUE (t2) == alias_decl
5305 || target == DECL_ASSEMBLER_NAME (TREE_VALUE (t2)))
5306 *p = TREE_CHAIN (t2);
5307 else
5308 p = &TREE_CHAIN (t2);
5311 /* Remove other weakrefs to the same target, to speed things up. */
5312 for (p = &TREE_CHAIN (t); (t2 = *p) ; )
5314 if (target == ultimate_transparent_alias_target (&TREE_VALUE (t2)))
5315 *p = TREE_CHAIN (t2);
5316 else
5317 p = &TREE_CHAIN (t2);
5322 for (t = weak_decls; t; t = TREE_CHAIN (t))
5324 tree decl = TREE_VALUE (t);
5326 weak_finish_1 (decl);
5330 /* Emit the assembly bits to indicate that DECL is globally visible. */
5332 static void
5333 globalize_decl (tree decl)
5336 #if defined (ASM_WEAKEN_LABEL) || defined (ASM_WEAKEN_DECL)
5337 if (DECL_WEAK (decl))
5339 const char *name = XSTR (XEXP (DECL_RTL (decl), 0), 0);
5340 tree *p, t;
5342 #ifdef ASM_WEAKEN_DECL
5343 ASM_WEAKEN_DECL (asm_out_file, decl, name, 0);
5344 #else
5345 ASM_WEAKEN_LABEL (asm_out_file, name);
5346 #endif
5348 /* Remove this function from the pending weak list so that
5349 we do not emit multiple .weak directives for it. */
5350 for (p = &weak_decls; (t = *p) ; )
5352 if (DECL_ASSEMBLER_NAME (decl) == DECL_ASSEMBLER_NAME (TREE_VALUE (t)))
5353 *p = TREE_CHAIN (t);
5354 else
5355 p = &TREE_CHAIN (t);
5358 /* Remove weakrefs to the same target from the pending weakref
5359 list, for the same reason. */
5360 for (p = &weakref_targets; (t = *p) ; )
5362 if (DECL_ASSEMBLER_NAME (decl)
5363 == ultimate_transparent_alias_target (&TREE_VALUE (t)))
5364 *p = TREE_CHAIN (t);
5365 else
5366 p = &TREE_CHAIN (t);
5369 return;
5371 #endif
5373 targetm.asm_out.globalize_decl_name (asm_out_file, decl);
5376 /* We have to be able to tell cgraph about the needed-ness of the target
5377 of an alias. This requires that the decl have been defined. Aliases
5378 that precede their definition have to be queued for later processing. */
5380 typedef struct GTY(()) alias_pair {
5381 tree decl;
5382 tree target;
5383 } alias_pair;
5385 /* Define gc'd vector type. */
5386 DEF_VEC_O(alias_pair);
5387 DEF_VEC_ALLOC_O(alias_pair,gc);
5389 static GTY(()) VEC(alias_pair,gc) *alias_pairs;
5391 /* Given an assembly name, find the decl it is associated with. At the
5392 same time, mark it needed for cgraph. */
5394 static tree
5395 find_decl_and_mark_needed (tree decl, tree target)
5397 struct cgraph_node *fnode = NULL;
5398 struct varpool_node *vnode = NULL;
5400 if (TREE_CODE (decl) == FUNCTION_DECL)
5402 fnode = cgraph_node_for_asm (target);
5403 if (fnode == NULL)
5404 vnode = varpool_node_for_asm (target);
5406 else
5408 vnode = varpool_node_for_asm (target);
5409 if (vnode == NULL)
5410 fnode = cgraph_node_for_asm (target);
5413 if (fnode)
5415 /* We can't mark function nodes as used after cgraph global info
5416 is finished. This wouldn't generally be necessary, but C++
5417 virtual table thunks are introduced late in the game and
5418 might seem like they need marking, although in fact they
5419 don't. */
5420 if (! cgraph_global_info_ready)
5421 cgraph_mark_needed_node (fnode);
5422 return fnode->decl;
5424 else if (vnode)
5426 varpool_mark_needed_node (vnode);
5427 return vnode->decl;
5429 else
5430 return NULL_TREE;
5433 /* Output the assembler code for a define (equate) using ASM_OUTPUT_DEF
5434 or ASM_OUTPUT_DEF_FROM_DECLS. The function defines the symbol whose
5435 tree node is DECL to have the value of the tree node TARGET. */
5437 static void
5438 do_assemble_alias (tree decl, tree target)
5440 if (TREE_ASM_WRITTEN (decl))
5441 return;
5443 TREE_ASM_WRITTEN (decl) = 1;
5444 TREE_ASM_WRITTEN (DECL_ASSEMBLER_NAME (decl)) = 1;
5446 if (lookup_attribute ("weakref", DECL_ATTRIBUTES (decl)))
5448 ultimate_transparent_alias_target (&target);
5450 if (!targetm.have_tls
5451 && TREE_CODE (decl) == VAR_DECL
5452 && DECL_THREAD_LOCAL_P (decl))
5454 decl = emutls_decl (decl);
5455 target = get_emutls_object_name (target);
5458 if (!TREE_SYMBOL_REFERENCED (target))
5459 weakref_targets = tree_cons (decl, target, weakref_targets);
5461 #ifdef ASM_OUTPUT_WEAKREF
5462 ASM_OUTPUT_WEAKREF (asm_out_file, decl,
5463 IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl)),
5464 IDENTIFIER_POINTER (target));
5465 #else
5466 if (!SUPPORTS_WEAK)
5468 error ("%Jweakref is not supported in this configuration", decl);
5469 return;
5471 #endif
5472 return;
5475 if (!targetm.have_tls
5476 && TREE_CODE (decl) == VAR_DECL
5477 && DECL_THREAD_LOCAL_P (decl))
5479 decl = emutls_decl (decl);
5480 target = get_emutls_object_name (target);
5483 #ifdef ASM_OUTPUT_DEF
5484 /* Make name accessible from other files, if appropriate. */
5486 if (TREE_PUBLIC (decl))
5488 globalize_decl (decl);
5489 maybe_assemble_visibility (decl);
5492 # ifdef ASM_OUTPUT_DEF_FROM_DECLS
5493 ASM_OUTPUT_DEF_FROM_DECLS (asm_out_file, decl, target);
5494 # else
5495 ASM_OUTPUT_DEF (asm_out_file,
5496 IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl)),
5497 IDENTIFIER_POINTER (target));
5498 # endif
5499 #elif defined (ASM_OUTPUT_WEAK_ALIAS) || defined (ASM_WEAKEN_DECL)
5501 const char *name;
5502 tree *p, t;
5504 name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
5505 # ifdef ASM_WEAKEN_DECL
5506 ASM_WEAKEN_DECL (asm_out_file, decl, name, IDENTIFIER_POINTER (target));
5507 # else
5508 ASM_OUTPUT_WEAK_ALIAS (asm_out_file, name, IDENTIFIER_POINTER (target));
5509 # endif
5510 /* Remove this function from the pending weak list so that
5511 we do not emit multiple .weak directives for it. */
5512 for (p = &weak_decls; (t = *p) ; )
5513 if (DECL_ASSEMBLER_NAME (decl) == DECL_ASSEMBLER_NAME (TREE_VALUE (t)))
5514 *p = TREE_CHAIN (t);
5515 else
5516 p = &TREE_CHAIN (t);
5518 /* Remove weakrefs to the same target from the pending weakref
5519 list, for the same reason. */
5520 for (p = &weakref_targets; (t = *p) ; )
5522 if (DECL_ASSEMBLER_NAME (decl)
5523 == ultimate_transparent_alias_target (&TREE_VALUE (t)))
5524 *p = TREE_CHAIN (t);
5525 else
5526 p = &TREE_CHAIN (t);
5529 #endif
5532 /* First pass of completing pending aliases. Make sure that cgraph knows
5533 which symbols will be required. */
5535 void
5536 finish_aliases_1 (void)
5538 unsigned i;
5539 alias_pair *p;
5541 for (i = 0; VEC_iterate (alias_pair, alias_pairs, i, p); i++)
5543 tree target_decl;
5545 target_decl = find_decl_and_mark_needed (p->decl, p->target);
5546 if (target_decl == NULL)
5548 if (! lookup_attribute ("weakref", DECL_ATTRIBUTES (p->decl)))
5549 error ("%q+D aliased to undefined symbol %qE",
5550 p->decl, p->target);
5552 else if (DECL_EXTERNAL (target_decl)
5553 && ! lookup_attribute ("weakref", DECL_ATTRIBUTES (p->decl)))
5554 error ("%q+D aliased to external symbol %qE",
5555 p->decl, p->target);
5559 /* Second pass of completing pending aliases. Emit the actual assembly.
5560 This happens at the end of compilation and thus it is assured that the
5561 target symbol has been emitted. */
5563 void
5564 finish_aliases_2 (void)
5566 unsigned i;
5567 alias_pair *p;
5569 for (i = 0; VEC_iterate (alias_pair, alias_pairs, i, p); i++)
5570 do_assemble_alias (p->decl, p->target);
5572 VEC_truncate (alias_pair, alias_pairs, 0);
5575 /* Emit an assembler directive to make the symbol for DECL an alias to
5576 the symbol for TARGET. */
5578 void
5579 assemble_alias (tree decl, tree target)
5581 tree target_decl;
5582 bool is_weakref = false;
5584 if (lookup_attribute ("weakref", DECL_ATTRIBUTES (decl)))
5586 tree alias = DECL_ASSEMBLER_NAME (decl);
5588 is_weakref = true;
5590 ultimate_transparent_alias_target (&target);
5592 if (alias == target)
5593 error ("weakref %q+D ultimately targets itself", decl);
5594 else
5596 #ifndef ASM_OUTPUT_WEAKREF
5597 IDENTIFIER_TRANSPARENT_ALIAS (alias) = 1;
5598 TREE_CHAIN (alias) = target;
5599 #endif
5601 if (TREE_PUBLIC (decl))
5602 error ("weakref %q+D must have static linkage", decl);
5604 else
5606 #if !defined (ASM_OUTPUT_DEF)
5607 # if !defined(ASM_OUTPUT_WEAK_ALIAS) && !defined (ASM_WEAKEN_DECL)
5608 error ("%Jalias definitions not supported in this configuration", decl);
5609 return;
5610 # else
5611 if (!DECL_WEAK (decl))
5613 error ("%Jonly weak aliases are supported in this configuration", decl);
5614 return;
5616 # endif
5617 #endif
5620 /* We must force creation of DECL_RTL for debug info generation, even though
5621 we don't use it here. */
5622 make_decl_rtl (decl);
5623 TREE_USED (decl) = 1;
5625 /* A quirk of the initial implementation of aliases required that the user
5626 add "extern" to all of them. Which is silly, but now historical. Do
5627 note that the symbol is in fact locally defined. */
5628 if (! is_weakref)
5629 DECL_EXTERNAL (decl) = 0;
5631 /* Allow aliases to aliases. */
5632 if (TREE_CODE (decl) == FUNCTION_DECL)
5633 cgraph_node (decl)->alias = true;
5634 else
5635 varpool_node (decl)->alias = true;
5637 /* If the target has already been emitted, we don't have to queue the
5638 alias. This saves a tad of memory. */
5639 if (cgraph_global_info_ready)
5640 target_decl = find_decl_and_mark_needed (decl, target);
5641 else
5642 target_decl= NULL;
5643 if (target_decl && TREE_ASM_WRITTEN (target_decl))
5644 do_assemble_alias (decl, target);
5645 else
5647 alias_pair *p = VEC_safe_push (alias_pair, gc, alias_pairs, NULL);
5648 p->decl = decl;
5649 p->target = target;
5653 /* Emit an assembler directive to set symbol for DECL visibility to
5654 the visibility type VIS, which must not be VISIBILITY_DEFAULT. */
5656 void
5657 default_assemble_visibility (tree decl, int vis)
5659 static const char * const visibility_types[] = {
5660 NULL, "protected", "hidden", "internal"
5663 const char *name, *type;
5665 name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
5666 type = visibility_types[vis];
5668 #ifdef HAVE_GAS_HIDDEN
5669 fprintf (asm_out_file, "\t.%s\t", type);
5670 assemble_name (asm_out_file, name);
5671 fprintf (asm_out_file, "\n");
5672 #else
5673 warning (OPT_Wattributes, "visibility attribute not supported "
5674 "in this configuration; ignored");
5675 #endif
5678 /* A helper function to call assemble_visibility when needed for a decl. */
5681 maybe_assemble_visibility (tree decl)
5683 enum symbol_visibility vis = DECL_VISIBILITY (decl);
5685 if (vis != VISIBILITY_DEFAULT)
5687 targetm.asm_out.visibility (decl, vis);
5688 return 1;
5690 else
5691 return 0;
5694 /* Returns 1 if the target configuration supports defining public symbols
5695 so that one of them will be chosen at link time instead of generating a
5696 multiply-defined symbol error, whether through the use of weak symbols or
5697 a target-specific mechanism for having duplicates discarded. */
5700 supports_one_only (void)
5702 if (SUPPORTS_ONE_ONLY)
5703 return 1;
5704 return SUPPORTS_WEAK;
5707 /* Set up DECL as a public symbol that can be defined in multiple
5708 translation units without generating a linker error. */
5710 void
5711 make_decl_one_only (tree decl, tree comdat_group)
5713 gcc_assert (TREE_CODE (decl) == VAR_DECL
5714 || TREE_CODE (decl) == FUNCTION_DECL);
5716 TREE_PUBLIC (decl) = 1;
5718 if (SUPPORTS_ONE_ONLY)
5720 #ifdef MAKE_DECL_ONE_ONLY
5721 MAKE_DECL_ONE_ONLY (decl);
5722 #endif
5723 DECL_COMDAT_GROUP (decl) = comdat_group;
5725 else if (TREE_CODE (decl) == VAR_DECL
5726 && (DECL_INITIAL (decl) == 0 || DECL_INITIAL (decl) == error_mark_node))
5727 DECL_COMMON (decl) = 1;
5728 else
5730 gcc_assert (SUPPORTS_WEAK);
5731 DECL_WEAK (decl) = 1;
5735 void
5736 init_varasm_once (void)
5738 section_htab = htab_create_ggc (31, section_entry_hash,
5739 section_entry_eq, NULL);
5740 object_block_htab = htab_create_ggc (31, object_block_entry_hash,
5741 object_block_entry_eq, NULL);
5742 const_desc_htab = htab_create_ggc (1009, const_desc_hash,
5743 const_desc_eq, NULL);
5745 const_alias_set = new_alias_set ();
5746 shared_constant_pool = create_constant_pool ();
5748 #ifdef TEXT_SECTION_ASM_OP
5749 text_section = get_unnamed_section (SECTION_CODE, output_section_asm_op,
5750 TEXT_SECTION_ASM_OP);
5751 #endif
5753 #ifdef DATA_SECTION_ASM_OP
5754 data_section = get_unnamed_section (SECTION_WRITE, output_section_asm_op,
5755 DATA_SECTION_ASM_OP);
5756 #endif
5758 #ifdef SDATA_SECTION_ASM_OP
5759 sdata_section = get_unnamed_section (SECTION_WRITE, output_section_asm_op,
5760 SDATA_SECTION_ASM_OP);
5761 #endif
5763 #ifdef READONLY_DATA_SECTION_ASM_OP
5764 readonly_data_section = get_unnamed_section (0, output_section_asm_op,
5765 READONLY_DATA_SECTION_ASM_OP);
5766 #endif
5768 #ifdef CTORS_SECTION_ASM_OP
5769 ctors_section = get_unnamed_section (0, output_section_asm_op,
5770 CTORS_SECTION_ASM_OP);
5771 #endif
5773 #ifdef DTORS_SECTION_ASM_OP
5774 dtors_section = get_unnamed_section (0, output_section_asm_op,
5775 DTORS_SECTION_ASM_OP);
5776 #endif
5778 #ifdef BSS_SECTION_ASM_OP
5779 bss_section = get_unnamed_section (SECTION_WRITE | SECTION_BSS,
5780 output_section_asm_op,
5781 BSS_SECTION_ASM_OP);
5782 #endif
5784 #ifdef SBSS_SECTION_ASM_OP
5785 sbss_section = get_unnamed_section (SECTION_WRITE | SECTION_BSS,
5786 output_section_asm_op,
5787 SBSS_SECTION_ASM_OP);
5788 #endif
5790 tls_comm_section = get_noswitch_section (SECTION_WRITE | SECTION_BSS
5791 | SECTION_COMMON, emit_tls_common);
5792 lcomm_section = get_noswitch_section (SECTION_WRITE | SECTION_BSS
5793 | SECTION_COMMON, emit_local);
5794 comm_section = get_noswitch_section (SECTION_WRITE | SECTION_BSS
5795 | SECTION_COMMON, emit_common);
5797 #if defined ASM_OUTPUT_ALIGNED_BSS || defined ASM_OUTPUT_BSS
5798 bss_noswitch_section = get_noswitch_section (SECTION_WRITE | SECTION_BSS,
5799 emit_bss);
5800 #endif
5802 targetm.asm_out.init_sections ();
5804 if (readonly_data_section == NULL)
5805 readonly_data_section = text_section;
5808 enum tls_model
5809 decl_default_tls_model (const_tree decl)
5811 enum tls_model kind;
5812 bool is_local;
5814 is_local = targetm.binds_local_p (decl);
5815 if (!flag_shlib)
5817 if (is_local)
5818 kind = TLS_MODEL_LOCAL_EXEC;
5819 else
5820 kind = TLS_MODEL_INITIAL_EXEC;
5823 /* Local dynamic is inefficient when we're not combining the
5824 parts of the address. */
5825 else if (optimize && is_local)
5826 kind = TLS_MODEL_LOCAL_DYNAMIC;
5827 else
5828 kind = TLS_MODEL_GLOBAL_DYNAMIC;
5829 if (kind < flag_tls_default)
5830 kind = flag_tls_default;
5832 return kind;
5835 /* Select a set of attributes for section NAME based on the properties
5836 of DECL and whether or not RELOC indicates that DECL's initializer
5837 might contain runtime relocations.
5839 We make the section read-only and executable for a function decl,
5840 read-only for a const data decl, and writable for a non-const data decl. */
5842 unsigned int
5843 default_section_type_flags (tree decl, const char *name, int reloc)
5845 unsigned int flags;
5847 if (decl && TREE_CODE (decl) == FUNCTION_DECL)
5848 flags = SECTION_CODE;
5849 else if (decl && decl_readonly_section (decl, reloc))
5850 flags = 0;
5851 else if (current_function_decl
5852 && cfun
5853 && crtl->subsections.unlikely_text_section_name
5854 && strcmp (name, crtl->subsections.unlikely_text_section_name) == 0)
5855 flags = SECTION_CODE;
5856 else if (!decl
5857 && (!current_function_decl || !cfun)
5858 && strcmp (name, UNLIKELY_EXECUTED_TEXT_SECTION_NAME) == 0)
5859 flags = SECTION_CODE;
5860 else
5861 flags = SECTION_WRITE;
5863 if (decl && DECL_ONE_ONLY (decl))
5864 flags |= SECTION_LINKONCE;
5866 if (decl && TREE_CODE (decl) == VAR_DECL && DECL_THREAD_LOCAL_P (decl))
5867 flags |= SECTION_TLS | SECTION_WRITE;
5869 if (strcmp (name, ".bss") == 0
5870 || strncmp (name, ".bss.", 5) == 0
5871 || strncmp (name, ".gnu.linkonce.b.", 16) == 0
5872 || strcmp (name, ".sbss") == 0
5873 || strncmp (name, ".sbss.", 6) == 0
5874 || strncmp (name, ".gnu.linkonce.sb.", 17) == 0)
5875 flags |= SECTION_BSS;
5877 if (strcmp (name, ".tdata") == 0
5878 || strncmp (name, ".tdata.", 7) == 0
5879 || strncmp (name, ".gnu.linkonce.td.", 17) == 0)
5880 flags |= SECTION_TLS;
5882 if (strcmp (name, ".tbss") == 0
5883 || strncmp (name, ".tbss.", 6) == 0
5884 || strncmp (name, ".gnu.linkonce.tb.", 17) == 0)
5885 flags |= SECTION_TLS | SECTION_BSS;
5887 /* These three sections have special ELF types. They are neither
5888 SHT_PROGBITS nor SHT_NOBITS, so when changing sections we don't
5889 want to print a section type (@progbits or @nobits). If someone
5890 is silly enough to emit code or TLS variables to one of these
5891 sections, then don't handle them specially. */
5892 if (!(flags & (SECTION_CODE | SECTION_BSS | SECTION_TLS))
5893 && (strcmp (name, ".init_array") == 0
5894 || strcmp (name, ".fini_array") == 0
5895 || strcmp (name, ".preinit_array") == 0))
5896 flags |= SECTION_NOTYPE;
5898 return flags;
5901 /* Return true if the target supports some form of global BSS,
5902 either through bss_noswitch_section, or by selecting a BSS
5903 section in TARGET_ASM_SELECT_SECTION. */
5905 bool
5906 have_global_bss_p (void)
5908 return bss_noswitch_section || targetm.have_switchable_bss_sections;
5911 /* Output assembly to switch to section NAME with attribute FLAGS.
5912 Four variants for common object file formats. */
5914 void
5915 default_no_named_section (const char *name ATTRIBUTE_UNUSED,
5916 unsigned int flags ATTRIBUTE_UNUSED,
5917 tree decl ATTRIBUTE_UNUSED)
5919 /* Some object formats don't support named sections at all. The
5920 front-end should already have flagged this as an error. */
5921 gcc_unreachable ();
5924 void
5925 default_elf_asm_named_section (const char *name, unsigned int flags,
5926 tree decl ATTRIBUTE_UNUSED)
5928 char flagchars[10], *f = flagchars;
5930 /* If we have already declared this section, we can use an
5931 abbreviated form to switch back to it -- unless this section is
5932 part of a COMDAT groups, in which case GAS requires the full
5933 declaration every time. */
5934 if (!(HAVE_COMDAT_GROUP && (flags & SECTION_LINKONCE))
5935 && (flags & SECTION_DECLARED))
5937 fprintf (asm_out_file, "\t.section\t%s\n", name);
5938 return;
5941 if (!(flags & SECTION_DEBUG))
5942 *f++ = 'a';
5943 if (flags & SECTION_WRITE)
5944 *f++ = 'w';
5945 if (flags & SECTION_CODE)
5946 *f++ = 'x';
5947 if (flags & SECTION_SMALL)
5948 *f++ = 's';
5949 if (flags & SECTION_MERGE)
5950 *f++ = 'M';
5951 if (flags & SECTION_STRINGS)
5952 *f++ = 'S';
5953 if (flags & SECTION_TLS)
5954 *f++ = 'T';
5955 if (HAVE_COMDAT_GROUP && (flags & SECTION_LINKONCE))
5956 *f++ = 'G';
5957 *f = '\0';
5959 fprintf (asm_out_file, "\t.section\t%s,\"%s\"", name, flagchars);
5961 if (!(flags & SECTION_NOTYPE))
5963 const char *type;
5964 const char *format;
5966 if (flags & SECTION_BSS)
5967 type = "nobits";
5968 else
5969 type = "progbits";
5971 format = ",@%s";
5972 #ifdef ASM_COMMENT_START
5973 /* On platforms that use "@" as the assembly comment character,
5974 use "%" instead. */
5975 if (strcmp (ASM_COMMENT_START, "@") == 0)
5976 format = ",%%%s";
5977 #endif
5978 fprintf (asm_out_file, format, type);
5980 if (flags & SECTION_ENTSIZE)
5981 fprintf (asm_out_file, ",%d", flags & SECTION_ENTSIZE);
5982 if (HAVE_COMDAT_GROUP && (flags & SECTION_LINKONCE))
5983 fprintf (asm_out_file, ",%s,comdat",
5984 IDENTIFIER_POINTER (DECL_COMDAT_GROUP (decl)));
5987 putc ('\n', asm_out_file);
5990 void
5991 default_coff_asm_named_section (const char *name, unsigned int flags,
5992 tree decl ATTRIBUTE_UNUSED)
5994 char flagchars[8], *f = flagchars;
5996 if (flags & SECTION_WRITE)
5997 *f++ = 'w';
5998 if (flags & SECTION_CODE)
5999 *f++ = 'x';
6000 *f = '\0';
6002 fprintf (asm_out_file, "\t.section\t%s,\"%s\"\n", name, flagchars);
6005 void
6006 default_pe_asm_named_section (const char *name, unsigned int flags,
6007 tree decl)
6009 default_coff_asm_named_section (name, flags, decl);
6011 if (flags & SECTION_LINKONCE)
6013 /* Functions may have been compiled at various levels of
6014 optimization so we can't use `same_size' here.
6015 Instead, have the linker pick one. */
6016 fprintf (asm_out_file, "\t.linkonce %s\n",
6017 (flags & SECTION_CODE ? "discard" : "same_size"));
6021 /* The lame default section selector. */
6023 section *
6024 default_select_section (tree decl, int reloc,
6025 unsigned HOST_WIDE_INT align ATTRIBUTE_UNUSED)
6027 if (DECL_P (decl))
6029 if (decl_readonly_section (decl, reloc))
6030 return readonly_data_section;
6032 else if (TREE_CODE (decl) == CONSTRUCTOR)
6034 if (! ((flag_pic && reloc)
6035 || !TREE_READONLY (decl)
6036 || TREE_SIDE_EFFECTS (decl)
6037 || !TREE_CONSTANT (decl)))
6038 return readonly_data_section;
6040 else if (TREE_CODE (decl) == STRING_CST)
6041 return readonly_data_section;
6042 else if (! (flag_pic && reloc))
6043 return readonly_data_section;
6045 return data_section;
6048 enum section_category
6049 categorize_decl_for_section (const_tree decl, int reloc)
6051 enum section_category ret;
6053 if (TREE_CODE (decl) == FUNCTION_DECL)
6054 return SECCAT_TEXT;
6055 else if (TREE_CODE (decl) == STRING_CST)
6057 if (flag_mudflap) /* or !flag_merge_constants */
6058 return SECCAT_RODATA;
6059 else
6060 return SECCAT_RODATA_MERGE_STR;
6062 else if (TREE_CODE (decl) == VAR_DECL)
6064 if (bss_initializer_p (decl))
6065 ret = SECCAT_BSS;
6066 else if (! TREE_READONLY (decl)
6067 || TREE_SIDE_EFFECTS (decl)
6068 || ! TREE_CONSTANT (DECL_INITIAL (decl)))
6070 /* Here the reloc_rw_mask is not testing whether the section should
6071 be read-only or not, but whether the dynamic link will have to
6072 do something. If so, we wish to segregate the data in order to
6073 minimize cache misses inside the dynamic linker. */
6074 if (reloc & targetm.asm_out.reloc_rw_mask ())
6075 ret = reloc == 1 ? SECCAT_DATA_REL_LOCAL : SECCAT_DATA_REL;
6076 else
6077 ret = SECCAT_DATA;
6079 else if (reloc & targetm.asm_out.reloc_rw_mask ())
6080 ret = reloc == 1 ? SECCAT_DATA_REL_RO_LOCAL : SECCAT_DATA_REL_RO;
6081 else if (reloc || flag_merge_constants < 2)
6082 /* C and C++ don't allow different variables to share the same
6083 location. -fmerge-all-constants allows even that (at the
6084 expense of not conforming). */
6085 ret = SECCAT_RODATA;
6086 else if (TREE_CODE (DECL_INITIAL (decl)) == STRING_CST)
6087 ret = SECCAT_RODATA_MERGE_STR_INIT;
6088 else
6089 ret = SECCAT_RODATA_MERGE_CONST;
6091 else if (TREE_CODE (decl) == CONSTRUCTOR)
6093 if ((reloc & targetm.asm_out.reloc_rw_mask ())
6094 || TREE_SIDE_EFFECTS (decl)
6095 || ! TREE_CONSTANT (decl))
6096 ret = SECCAT_DATA;
6097 else
6098 ret = SECCAT_RODATA;
6100 else
6101 ret = SECCAT_RODATA;
6103 /* There are no read-only thread-local sections. */
6104 if (TREE_CODE (decl) == VAR_DECL && DECL_TLS_MODEL (decl))
6106 if (DECL_TLS_MODEL (decl) == TLS_MODEL_EMULATED)
6108 if (DECL_EMUTLS_VAR_P (decl))
6110 if (targetm.emutls.var_section)
6111 ret = SECCAT_EMUTLS_VAR;
6113 else
6115 if (targetm.emutls.tmpl_prefix)
6116 ret = SECCAT_EMUTLS_TMPL;
6119 /* Note that this would be *just* SECCAT_BSS, except that there's
6120 no concept of a read-only thread-local-data section. */
6121 else if (ret == SECCAT_BSS
6122 || (flag_zero_initialized_in_bss
6123 && initializer_zerop (DECL_INITIAL (decl))))
6124 ret = SECCAT_TBSS;
6125 else
6126 ret = SECCAT_TDATA;
6129 /* If the target uses small data sections, select it. */
6130 else if (targetm.in_small_data_p (decl))
6132 if (ret == SECCAT_BSS)
6133 ret = SECCAT_SBSS;
6134 else if (targetm.have_srodata_section && ret == SECCAT_RODATA)
6135 ret = SECCAT_SRODATA;
6136 else
6137 ret = SECCAT_SDATA;
6140 return ret;
6143 bool
6144 decl_readonly_section (const_tree decl, int reloc)
6146 switch (categorize_decl_for_section (decl, reloc))
6148 case SECCAT_RODATA:
6149 case SECCAT_RODATA_MERGE_STR:
6150 case SECCAT_RODATA_MERGE_STR_INIT:
6151 case SECCAT_RODATA_MERGE_CONST:
6152 case SECCAT_SRODATA:
6153 return true;
6154 break;
6155 default:
6156 return false;
6157 break;
6161 /* Select a section based on the above categorization. */
6163 section *
6164 default_elf_select_section (tree decl, int reloc,
6165 unsigned HOST_WIDE_INT align)
6167 const char *sname;
6168 switch (categorize_decl_for_section (decl, reloc))
6170 case SECCAT_TEXT:
6171 /* We're not supposed to be called on FUNCTION_DECLs. */
6172 gcc_unreachable ();
6173 case SECCAT_RODATA:
6174 return readonly_data_section;
6175 case SECCAT_RODATA_MERGE_STR:
6176 return mergeable_string_section (decl, align, 0);
6177 case SECCAT_RODATA_MERGE_STR_INIT:
6178 return mergeable_string_section (DECL_INITIAL (decl), align, 0);
6179 case SECCAT_RODATA_MERGE_CONST:
6180 return mergeable_constant_section (DECL_MODE (decl), align, 0);
6181 case SECCAT_SRODATA:
6182 sname = ".sdata2";
6183 break;
6184 case SECCAT_DATA:
6185 return data_section;
6186 case SECCAT_DATA_REL:
6187 sname = ".data.rel";
6188 break;
6189 case SECCAT_DATA_REL_LOCAL:
6190 sname = ".data.rel.local";
6191 break;
6192 case SECCAT_DATA_REL_RO:
6193 sname = ".data.rel.ro";
6194 break;
6195 case SECCAT_DATA_REL_RO_LOCAL:
6196 sname = ".data.rel.ro.local";
6197 break;
6198 case SECCAT_SDATA:
6199 sname = ".sdata";
6200 break;
6201 case SECCAT_TDATA:
6202 sname = ".tdata";
6203 break;
6204 case SECCAT_BSS:
6205 if (bss_section)
6206 return bss_section;
6207 sname = ".bss";
6208 break;
6209 case SECCAT_SBSS:
6210 sname = ".sbss";
6211 break;
6212 case SECCAT_TBSS:
6213 sname = ".tbss";
6214 break;
6215 case SECCAT_EMUTLS_VAR:
6216 sname = targetm.emutls.var_section;
6217 break;
6218 case SECCAT_EMUTLS_TMPL:
6219 sname = targetm.emutls.tmpl_section;
6220 break;
6221 default:
6222 gcc_unreachable ();
6225 if (!DECL_P (decl))
6226 decl = NULL_TREE;
6227 return get_named_section (decl, sname, reloc);
6230 /* Construct a unique section name based on the decl name and the
6231 categorization performed above. */
6233 void
6234 default_unique_section (tree decl, int reloc)
6236 /* We only need to use .gnu.linkonce if we don't have COMDAT groups. */
6237 bool one_only = DECL_ONE_ONLY (decl) && !HAVE_COMDAT_GROUP;
6238 const char *prefix, *name, *linkonce;
6239 char *string;
6241 switch (categorize_decl_for_section (decl, reloc))
6243 case SECCAT_TEXT:
6244 prefix = one_only ? ".t" : ".text";
6245 break;
6246 case SECCAT_RODATA:
6247 case SECCAT_RODATA_MERGE_STR:
6248 case SECCAT_RODATA_MERGE_STR_INIT:
6249 case SECCAT_RODATA_MERGE_CONST:
6250 prefix = one_only ? ".r" : ".rodata";
6251 break;
6252 case SECCAT_SRODATA:
6253 prefix = one_only ? ".s2" : ".sdata2";
6254 break;
6255 case SECCAT_DATA:
6256 prefix = one_only ? ".d" : ".data";
6257 break;
6258 case SECCAT_DATA_REL:
6259 prefix = one_only ? ".d.rel" : ".data.rel";
6260 break;
6261 case SECCAT_DATA_REL_LOCAL:
6262 prefix = one_only ? ".d.rel.local" : ".data.rel.local";
6263 break;
6264 case SECCAT_DATA_REL_RO:
6265 prefix = one_only ? ".d.rel.ro" : ".data.rel.ro";
6266 break;
6267 case SECCAT_DATA_REL_RO_LOCAL:
6268 prefix = one_only ? ".d.rel.ro.local" : ".data.rel.ro.local";
6269 break;
6270 case SECCAT_SDATA:
6271 prefix = one_only ? ".s" : ".sdata";
6272 break;
6273 case SECCAT_BSS:
6274 prefix = one_only ? ".b" : ".bss";
6275 break;
6276 case SECCAT_SBSS:
6277 prefix = one_only ? ".sb" : ".sbss";
6278 break;
6279 case SECCAT_TDATA:
6280 prefix = one_only ? ".td" : ".tdata";
6281 break;
6282 case SECCAT_TBSS:
6283 prefix = one_only ? ".tb" : ".tbss";
6284 break;
6285 case SECCAT_EMUTLS_VAR:
6286 prefix = targetm.emutls.var_section;
6287 break;
6288 case SECCAT_EMUTLS_TMPL:
6289 prefix = targetm.emutls.tmpl_section;
6290 break;
6291 default:
6292 gcc_unreachable ();
6295 name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
6296 name = targetm.strip_name_encoding (name);
6298 /* If we're using one_only, then there needs to be a .gnu.linkonce
6299 prefix to the section name. */
6300 linkonce = one_only ? ".gnu.linkonce" : "";
6302 string = ACONCAT ((linkonce, prefix, ".", name, NULL));
6304 DECL_SECTION_NAME (decl) = build_string (strlen (string), string);
6307 /* Like compute_reloc_for_constant, except for an RTX. The return value
6308 is a mask for which bit 1 indicates a global relocation, and bit 0
6309 indicates a local relocation. */
6311 static int
6312 compute_reloc_for_rtx_1 (rtx *xp, void *data)
6314 int *preloc = (int *) data;
6315 rtx x = *xp;
6317 switch (GET_CODE (x))
6319 case SYMBOL_REF:
6320 *preloc |= SYMBOL_REF_LOCAL_P (x) ? 1 : 2;
6321 break;
6322 case LABEL_REF:
6323 *preloc |= 1;
6324 break;
6325 default:
6326 break;
6329 return 0;
6332 static int
6333 compute_reloc_for_rtx (rtx x)
6335 int reloc;
6337 switch (GET_CODE (x))
6339 case CONST:
6340 case SYMBOL_REF:
6341 case LABEL_REF:
6342 reloc = 0;
6343 for_each_rtx (&x, compute_reloc_for_rtx_1, &reloc);
6344 return reloc;
6346 default:
6347 return 0;
6351 section *
6352 default_select_rtx_section (enum machine_mode mode ATTRIBUTE_UNUSED,
6353 rtx x,
6354 unsigned HOST_WIDE_INT align ATTRIBUTE_UNUSED)
6356 if (compute_reloc_for_rtx (x) & targetm.asm_out.reloc_rw_mask ())
6357 return data_section;
6358 else
6359 return readonly_data_section;
6362 section *
6363 default_elf_select_rtx_section (enum machine_mode mode, rtx x,
6364 unsigned HOST_WIDE_INT align)
6366 int reloc = compute_reloc_for_rtx (x);
6368 /* ??? Handle small data here somehow. */
6370 if (reloc & targetm.asm_out.reloc_rw_mask ())
6372 if (reloc == 1)
6373 return get_named_section (NULL, ".data.rel.ro.local", 1);
6374 else
6375 return get_named_section (NULL, ".data.rel.ro", 3);
6378 return mergeable_constant_section (mode, align, 0);
6381 /* Set the generally applicable flags on the SYMBOL_REF for EXP. */
6383 void
6384 default_encode_section_info (tree decl, rtx rtl, int first ATTRIBUTE_UNUSED)
6386 rtx symbol;
6387 int flags;
6389 /* Careful not to prod global register variables. */
6390 if (!MEM_P (rtl))
6391 return;
6392 symbol = XEXP (rtl, 0);
6393 if (GET_CODE (symbol) != SYMBOL_REF)
6394 return;
6396 flags = SYMBOL_REF_FLAGS (symbol) & SYMBOL_FLAG_HAS_BLOCK_INFO;
6397 if (TREE_CODE (decl) == FUNCTION_DECL)
6398 flags |= SYMBOL_FLAG_FUNCTION;
6399 if (targetm.binds_local_p (decl))
6400 flags |= SYMBOL_FLAG_LOCAL;
6401 if (targetm.have_tls && TREE_CODE (decl) == VAR_DECL
6402 && DECL_THREAD_LOCAL_P (decl))
6403 flags |= DECL_TLS_MODEL (decl) << SYMBOL_FLAG_TLS_SHIFT;
6404 else if (targetm.in_small_data_p (decl))
6405 flags |= SYMBOL_FLAG_SMALL;
6406 /* ??? Why is DECL_EXTERNAL ever set for non-PUBLIC names? Without
6407 being PUBLIC, the thing *must* be defined in this translation unit.
6408 Prevent this buglet from being propagated into rtl code as well. */
6409 if (DECL_P (decl) && DECL_EXTERNAL (decl) && TREE_PUBLIC (decl))
6410 flags |= SYMBOL_FLAG_EXTERNAL;
6412 SYMBOL_REF_FLAGS (symbol) = flags;
6415 /* By default, we do nothing for encode_section_info, so we need not
6416 do anything but discard the '*' marker. */
6418 const char *
6419 default_strip_name_encoding (const char *str)
6421 return str + (*str == '*');
6424 #ifdef ASM_OUTPUT_DEF
6425 /* The default implementation of TARGET_ASM_OUTPUT_ANCHOR. Define the
6426 anchor relative to ".", the current section position. */
6428 void
6429 default_asm_output_anchor (rtx symbol)
6431 char buffer[100];
6433 sprintf (buffer, "*. + " HOST_WIDE_INT_PRINT_DEC,
6434 SYMBOL_REF_BLOCK_OFFSET (symbol));
6435 ASM_OUTPUT_DEF (asm_out_file, XSTR (symbol, 0), buffer);
6437 #endif
6439 /* The default implementation of TARGET_USE_ANCHORS_FOR_SYMBOL_P. */
6441 bool
6442 default_use_anchors_for_symbol_p (const_rtx symbol)
6444 section *sect;
6445 tree decl;
6447 /* Don't use anchors for mergeable sections. The linker might move
6448 the objects around. */
6449 sect = SYMBOL_REF_BLOCK (symbol)->sect;
6450 if (sect->common.flags & SECTION_MERGE)
6451 return false;
6453 /* Don't use anchors for small data sections. The small data register
6454 acts as an anchor for such sections. */
6455 if (sect->common.flags & SECTION_SMALL)
6456 return false;
6458 decl = SYMBOL_REF_DECL (symbol);
6459 if (decl && DECL_P (decl))
6461 /* Don't use section anchors for decls that might be defined by
6462 other modules. */
6463 if (!targetm.binds_local_p (decl))
6464 return false;
6466 /* Don't use section anchors for decls that will be placed in a
6467 small data section. */
6468 /* ??? Ideally, this check would be redundant with the SECTION_SMALL
6469 one above. The problem is that we only use SECTION_SMALL for
6470 sections that should be marked as small in the section directive. */
6471 if (targetm.in_small_data_p (decl))
6472 return false;
6474 return true;
6477 /* Assume ELF-ish defaults, since that's pretty much the most liberal
6478 wrt cross-module name binding. */
6480 bool
6481 default_binds_local_p (const_tree exp)
6483 return default_binds_local_p_1 (exp, flag_shlib);
6486 bool
6487 default_binds_local_p_1 (const_tree exp, int shlib)
6489 bool local_p;
6491 /* A non-decl is an entry in the constant pool. */
6492 if (!DECL_P (exp))
6493 local_p = true;
6494 /* Weakrefs may not bind locally, even though the weakref itself is
6495 always static and therefore local. */
6496 else if (lookup_attribute ("weakref", DECL_ATTRIBUTES (exp)))
6497 local_p = false;
6498 /* Static variables are always local. */
6499 else if (! TREE_PUBLIC (exp))
6500 local_p = true;
6501 /* A variable is local if the user has said explicitly that it will
6502 be. */
6503 else if (DECL_VISIBILITY_SPECIFIED (exp)
6504 && DECL_VISIBILITY (exp) != VISIBILITY_DEFAULT)
6505 local_p = true;
6506 /* Variables defined outside this object might not be local. */
6507 else if (DECL_EXTERNAL (exp))
6508 local_p = false;
6509 /* If defined in this object and visibility is not default, must be
6510 local. */
6511 else if (DECL_VISIBILITY (exp) != VISIBILITY_DEFAULT)
6512 local_p = true;
6513 /* Default visibility weak data can be overridden by a strong symbol
6514 in another module and so are not local. */
6515 else if (DECL_WEAK (exp))
6516 local_p = false;
6517 /* If PIC, then assume that any global name can be overridden by
6518 symbols resolved from other modules, unless we are compiling with
6519 -fwhole-program, which assumes that names are local. */
6520 else if (shlib)
6521 local_p = flag_whole_program;
6522 /* Uninitialized COMMON variable may be unified with symbols
6523 resolved from other modules. */
6524 else if (DECL_COMMON (exp)
6525 && (DECL_INITIAL (exp) == NULL
6526 || DECL_INITIAL (exp) == error_mark_node))
6527 local_p = false;
6528 /* Otherwise we're left with initialized (or non-common) global data
6529 which is of necessity defined locally. */
6530 else
6531 local_p = true;
6533 return local_p;
6536 /* Determine whether or not a pointer mode is valid. Assume defaults
6537 of ptr_mode or Pmode - can be overridden. */
6538 bool
6539 default_valid_pointer_mode (enum machine_mode mode)
6541 return (mode == ptr_mode || mode == Pmode);
6544 /* Default function to output code that will globalize a label. A
6545 target must define GLOBAL_ASM_OP or provide its own function to
6546 globalize a label. */
6547 #ifdef GLOBAL_ASM_OP
6548 void
6549 default_globalize_label (FILE * stream, const char *name)
6551 fputs (GLOBAL_ASM_OP, stream);
6552 assemble_name (stream, name);
6553 putc ('\n', stream);
6555 #endif /* GLOBAL_ASM_OP */
6557 /* Default function to output code that will globalize a declaration. */
6558 void
6559 default_globalize_decl_name (FILE * stream, tree decl)
6561 const char *name = XSTR (XEXP (DECL_RTL (decl), 0), 0);
6562 targetm.asm_out.globalize_label (stream, name);
6565 /* Default function to output a label for unwind information. The
6566 default is to do nothing. A target that needs nonlocal labels for
6567 unwind information must provide its own function to do this. */
6568 void
6569 default_emit_unwind_label (FILE * stream ATTRIBUTE_UNUSED,
6570 tree decl ATTRIBUTE_UNUSED,
6571 int for_eh ATTRIBUTE_UNUSED,
6572 int empty ATTRIBUTE_UNUSED)
6576 /* Default function to output a label to divide up the exception table.
6577 The default is to do nothing. A target that needs/wants to divide
6578 up the table must provide it's own function to do this. */
6579 void
6580 default_emit_except_table_label (FILE * stream ATTRIBUTE_UNUSED)
6584 /* This is how to output an internal numbered label where PREFIX is
6585 the class of label and LABELNO is the number within the class. */
6587 void
6588 default_internal_label (FILE *stream, const char *prefix,
6589 unsigned long labelno)
6591 char *const buf = (char *) alloca (40 + strlen (prefix));
6592 ASM_GENERATE_INTERNAL_LABEL (buf, prefix, labelno);
6593 ASM_OUTPUT_INTERNAL_LABEL (stream, buf);
6596 /* This is the default behavior at the beginning of a file. It's
6597 controlled by two other target-hook toggles. */
6598 void
6599 default_file_start (void)
6601 if (targetm.file_start_app_off
6602 && !(flag_verbose_asm || flag_debug_asm || flag_dump_rtl_in_asm))
6603 fputs (ASM_APP_OFF, asm_out_file);
6605 if (targetm.file_start_file_directive)
6606 output_file_directive (asm_out_file, main_input_filename);
6609 /* This is a generic routine suitable for use as TARGET_ASM_FILE_END
6610 which emits a special section directive used to indicate whether or
6611 not this object file needs an executable stack. This is primarily
6612 a GNU extension to ELF but could be used on other targets. */
6614 int trampolines_created;
6616 void
6617 file_end_indicate_exec_stack (void)
6619 unsigned int flags = SECTION_DEBUG;
6620 if (trampolines_created)
6621 flags |= SECTION_CODE;
6623 switch_to_section (get_section (".note.GNU-stack", flags, NULL));
6626 /* Output DIRECTIVE (a C string) followed by a newline. This is used as
6627 a get_unnamed_section callback. */
6629 void
6630 output_section_asm_op (const void *directive)
6632 fprintf (asm_out_file, "%s\n", (const char *) directive);
6635 /* Emit assembly code to switch to section NEW_SECTION. Do nothing if
6636 the current section is NEW_SECTION. */
6638 void
6639 switch_to_section (section *new_section)
6641 if (in_section == new_section)
6642 return;
6644 if (new_section->common.flags & SECTION_FORGET)
6645 in_section = NULL;
6646 else
6647 in_section = new_section;
6649 switch (SECTION_STYLE (new_section))
6651 case SECTION_NAMED:
6652 if (cfun
6653 && !crtl->subsections.unlikely_text_section_name
6654 && strcmp (new_section->named.name,
6655 UNLIKELY_EXECUTED_TEXT_SECTION_NAME) == 0)
6656 crtl->subsections.unlikely_text_section_name = UNLIKELY_EXECUTED_TEXT_SECTION_NAME;
6658 targetm.asm_out.named_section (new_section->named.name,
6659 new_section->named.common.flags,
6660 new_section->named.decl);
6661 break;
6663 case SECTION_UNNAMED:
6664 new_section->unnamed.callback (new_section->unnamed.data);
6665 break;
6667 case SECTION_NOSWITCH:
6668 gcc_unreachable ();
6669 break;
6672 new_section->common.flags |= SECTION_DECLARED;
6675 /* If block symbol SYMBOL has not yet been assigned an offset, place
6676 it at the end of its block. */
6678 void
6679 place_block_symbol (rtx symbol)
6681 unsigned HOST_WIDE_INT size, mask, offset;
6682 struct constant_descriptor_rtx *desc;
6683 unsigned int alignment;
6684 struct object_block *block;
6685 tree decl;
6687 gcc_assert (SYMBOL_REF_BLOCK (symbol));
6688 if (SYMBOL_REF_BLOCK_OFFSET (symbol) >= 0)
6689 return;
6691 /* Work out the symbol's size and alignment. */
6692 if (CONSTANT_POOL_ADDRESS_P (symbol))
6694 desc = SYMBOL_REF_CONSTANT (symbol);
6695 alignment = desc->align;
6696 size = GET_MODE_SIZE (desc->mode);
6698 else if (TREE_CONSTANT_POOL_ADDRESS_P (symbol))
6700 decl = SYMBOL_REF_DECL (symbol);
6701 alignment = get_constant_alignment (decl);
6702 size = get_constant_size (decl);
6704 else
6706 decl = SYMBOL_REF_DECL (symbol);
6707 alignment = DECL_ALIGN (decl);
6708 size = tree_low_cst (DECL_SIZE_UNIT (decl), 1);
6711 /* Calculate the object's offset from the start of the block. */
6712 block = SYMBOL_REF_BLOCK (symbol);
6713 mask = alignment / BITS_PER_UNIT - 1;
6714 offset = (block->size + mask) & ~mask;
6715 SYMBOL_REF_BLOCK_OFFSET (symbol) = offset;
6717 /* Record the block's new alignment and size. */
6718 block->alignment = MAX (block->alignment, alignment);
6719 block->size = offset + size;
6721 VEC_safe_push (rtx, gc, block->objects, symbol);
6724 /* Return the anchor that should be used to address byte offset OFFSET
6725 from the first object in BLOCK. MODEL is the TLS model used
6726 to access it. */
6729 get_section_anchor (struct object_block *block, HOST_WIDE_INT offset,
6730 enum tls_model model)
6732 char label[100];
6733 unsigned int begin, middle, end;
6734 unsigned HOST_WIDE_INT min_offset, max_offset, range, bias, delta;
6735 rtx anchor;
6737 /* Work out the anchor's offset. Use an offset of 0 for the first
6738 anchor so that we don't pessimize the case where we take the address
6739 of a variable at the beginning of the block. This is particularly
6740 useful when a block has only one variable assigned to it.
6742 We try to place anchors RANGE bytes apart, so there can then be
6743 anchors at +/-RANGE, +/-2 * RANGE, and so on, up to the limits of
6744 a ptr_mode offset. With some target settings, the lowest such
6745 anchor might be out of range for the lowest ptr_mode offset;
6746 likewise the highest anchor for the highest offset. Use anchors
6747 at the extreme ends of the ptr_mode range in such cases.
6749 All arithmetic uses unsigned integers in order to avoid
6750 signed overflow. */
6751 max_offset = (unsigned HOST_WIDE_INT) targetm.max_anchor_offset;
6752 min_offset = (unsigned HOST_WIDE_INT) targetm.min_anchor_offset;
6753 range = max_offset - min_offset + 1;
6754 if (range == 0)
6755 offset = 0;
6756 else
6758 bias = 1 << (GET_MODE_BITSIZE (ptr_mode) - 1);
6759 if (offset < 0)
6761 delta = -(unsigned HOST_WIDE_INT) offset + max_offset;
6762 delta -= delta % range;
6763 if (delta > bias)
6764 delta = bias;
6765 offset = (HOST_WIDE_INT) (-delta);
6767 else
6769 delta = (unsigned HOST_WIDE_INT) offset - min_offset;
6770 delta -= delta % range;
6771 if (delta > bias - 1)
6772 delta = bias - 1;
6773 offset = (HOST_WIDE_INT) delta;
6777 /* Do a binary search to see if there's already an anchor we can use.
6778 Set BEGIN to the new anchor's index if not. */
6779 begin = 0;
6780 end = VEC_length (rtx, block->anchors);
6781 while (begin != end)
6783 middle = (end + begin) / 2;
6784 anchor = VEC_index (rtx, block->anchors, middle);
6785 if (SYMBOL_REF_BLOCK_OFFSET (anchor) > offset)
6786 end = middle;
6787 else if (SYMBOL_REF_BLOCK_OFFSET (anchor) < offset)
6788 begin = middle + 1;
6789 else if (SYMBOL_REF_TLS_MODEL (anchor) > model)
6790 end = middle;
6791 else if (SYMBOL_REF_TLS_MODEL (anchor) < model)
6792 begin = middle + 1;
6793 else
6794 return anchor;
6797 /* Create a new anchor with a unique label. */
6798 ASM_GENERATE_INTERNAL_LABEL (label, "LANCHOR", anchor_labelno++);
6799 anchor = create_block_symbol (ggc_strdup (label), block, offset);
6800 SYMBOL_REF_FLAGS (anchor) |= SYMBOL_FLAG_LOCAL | SYMBOL_FLAG_ANCHOR;
6801 SYMBOL_REF_FLAGS (anchor) |= model << SYMBOL_FLAG_TLS_SHIFT;
6803 /* Insert it at index BEGIN. */
6804 VEC_safe_insert (rtx, gc, block->anchors, begin, anchor);
6805 return anchor;
6808 /* Output the objects in BLOCK. */
6810 static void
6811 output_object_block (struct object_block *block)
6813 struct constant_descriptor_rtx *desc;
6814 unsigned int i;
6815 HOST_WIDE_INT offset;
6816 tree decl;
6817 rtx symbol;
6819 if (block->objects == NULL)
6820 return;
6822 /* Switch to the section and make sure that the first byte is
6823 suitably aligned. */
6824 switch_to_section (block->sect);
6825 assemble_align (block->alignment);
6827 /* Define the values of all anchors relative to the current section
6828 position. */
6829 for (i = 0; VEC_iterate (rtx, block->anchors, i, symbol); i++)
6830 targetm.asm_out.output_anchor (symbol);
6832 /* Output the objects themselves. */
6833 offset = 0;
6834 for (i = 0; VEC_iterate (rtx, block->objects, i, symbol); i++)
6836 /* Move to the object's offset, padding with zeros if necessary. */
6837 assemble_zeros (SYMBOL_REF_BLOCK_OFFSET (symbol) - offset);
6838 offset = SYMBOL_REF_BLOCK_OFFSET (symbol);
6839 if (CONSTANT_POOL_ADDRESS_P (symbol))
6841 desc = SYMBOL_REF_CONSTANT (symbol);
6842 output_constant_pool_1 (desc, 1);
6843 offset += GET_MODE_SIZE (desc->mode);
6845 else if (TREE_CONSTANT_POOL_ADDRESS_P (symbol))
6847 decl = SYMBOL_REF_DECL (symbol);
6848 assemble_constant_contents (decl, XSTR (symbol, 0),
6849 get_constant_alignment (decl));
6850 offset += get_constant_size (decl);
6852 else
6854 decl = SYMBOL_REF_DECL (symbol);
6855 assemble_variable_contents (decl, XSTR (symbol, 0), false);
6856 offset += tree_low_cst (DECL_SIZE_UNIT (decl), 1);
6861 /* A htab_traverse callback used to call output_object_block for
6862 each member of object_block_htab. */
6864 static int
6865 output_object_block_htab (void **slot, void *data ATTRIBUTE_UNUSED)
6867 output_object_block ((struct object_block *) (*slot));
6868 return 1;
6871 /* Output the definitions of all object_blocks. */
6873 void
6874 output_object_blocks (void)
6876 htab_traverse (object_block_htab, output_object_block_htab, NULL);
6879 /* This function provides a possible implementation of the
6880 TARGET_ASM_RECORD_GCC_SWITCHES target hook for ELF targets. When triggered
6881 by -frecord-gcc-switches it creates a new mergeable, string section in the
6882 assembler output file called TARGET_ASM_RECORD_GCC_SWITCHES_SECTION which
6883 contains the switches in ASCII format.
6885 FIXME: This code does not correctly handle double quote characters
6886 that appear inside strings, (it strips them rather than preserving them).
6887 FIXME: ASM_OUTPUT_ASCII, as defined in config/elfos.h will not emit NUL
6888 characters - instead it treats them as sub-string separators. Since
6889 we want to emit NUL strings terminators into the object file we have to use
6890 ASM_OUTPUT_SKIP. */
6893 elf_record_gcc_switches (print_switch_type type, const char * name)
6895 static char buffer[1024];
6897 /* This variable is used as part of a simplistic heuristic to detect
6898 command line switches which take an argument:
6900 "If a command line option does not start with a dash then
6901 it is an argument for the previous command line option."
6903 This fails in the case of the command line option which is the name
6904 of the file to compile, but otherwise it is pretty reasonable. */
6905 static bool previous_name_held_back = FALSE;
6907 switch (type)
6909 case SWITCH_TYPE_PASSED:
6910 if (* name != '-')
6912 if (previous_name_held_back)
6914 unsigned int len = strlen (buffer);
6916 snprintf (buffer + len, sizeof buffer - len, " %s", name);
6917 ASM_OUTPUT_ASCII (asm_out_file, buffer, strlen (buffer));
6918 ASM_OUTPUT_SKIP (asm_out_file, (unsigned HOST_WIDE_INT) 1);
6919 previous_name_held_back = FALSE;
6921 else
6923 strncpy (buffer, name, sizeof buffer);
6924 ASM_OUTPUT_ASCII (asm_out_file, buffer, strlen (buffer));
6925 ASM_OUTPUT_SKIP (asm_out_file, (unsigned HOST_WIDE_INT) 1);
6928 else
6930 if (previous_name_held_back)
6932 ASM_OUTPUT_ASCII (asm_out_file, buffer, strlen (buffer));
6933 ASM_OUTPUT_SKIP (asm_out_file, (unsigned HOST_WIDE_INT) 1);
6936 strncpy (buffer, name, sizeof buffer);
6937 previous_name_held_back = TRUE;
6939 break;
6941 case SWITCH_TYPE_DESCRIPTIVE:
6942 if (name == NULL)
6944 /* Distinguish between invocations where name is NULL. */
6945 static bool started = false;
6947 if (started)
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 else
6957 section * sec;
6959 sec = get_section (targetm.asm_out.record_gcc_switches_section,
6960 SECTION_DEBUG
6961 | SECTION_MERGE
6962 | SECTION_STRINGS
6963 | (SECTION_ENTSIZE & 1),
6964 NULL);
6965 switch_to_section (sec);
6966 started = true;
6970 default:
6971 break;
6974 /* The return value is currently ignored by the caller, but must be 0.
6975 For -fverbose-asm the return value would be the number of characters
6976 emitted into the assembler file. */
6977 return 0;
6980 /* Emit text to declare externally defined symbols. It is needed to
6981 properly support non-default visibility. */
6982 void
6983 default_elf_asm_output_external (FILE *file ATTRIBUTE_UNUSED,
6984 tree decl,
6985 const char *name ATTRIBUTE_UNUSED)
6987 /* We output the name if and only if TREE_SYMBOL_REFERENCED is
6988 set in order to avoid putting out names that are never really
6989 used. */
6990 if (TREE_SYMBOL_REFERENCED (DECL_ASSEMBLER_NAME (decl))
6991 && targetm.binds_local_p (decl))
6992 maybe_assemble_visibility (decl);
6995 #include "gt-varasm.h"