PR libgomp/38270
[official-gcc.git] / gcc / varasm.c
blob7fed3009b84a748237df9c23c5e04cbad4ec521d
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
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 "c-pragma.h"
46 #include "ggc.h"
47 #include "langhooks.h"
48 #include "tm_p.h"
49 #include "debug.h"
50 #include "target.h"
51 #include "targhooks.h"
52 #include "tree-mudflap.h"
53 #include "cgraph.h"
54 #include "cfglayout.h"
55 #include "basic-block.h"
56 #include "tree-iterator.h"
58 #ifdef XCOFF_DEBUGGING_INFO
59 #include "xcoffout.h" /* Needed for external data
60 declarations for e.g. AIX 4.x. */
61 #endif
63 /* The (assembler) name of the first globally-visible object output. */
64 extern GTY(()) const char *first_global_object_name;
65 extern GTY(()) const char *weak_global_object_name;
67 const char *first_global_object_name;
68 const char *weak_global_object_name;
70 struct addr_const;
71 struct constant_descriptor_rtx;
72 struct rtx_constant_pool;
74 #define n_deferred_constants (crtl->varasm.deferred_constants)
76 /* Number for making the label on the next
77 constant that is stored in memory. */
79 static GTY(()) int const_labelno;
81 /* Carry information from ASM_DECLARE_OBJECT_NAME
82 to ASM_FINISH_DECLARE_OBJECT. */
84 int size_directive_output;
86 /* The last decl for which assemble_variable was called,
87 if it did ASM_DECLARE_OBJECT_NAME.
88 If the last call to assemble_variable didn't do that,
89 this holds 0. */
91 tree last_assemble_variable_decl;
93 /* The following global variable indicates if the first basic block
94 in a function belongs to the cold partition or not. */
96 bool first_function_block_is_cold;
98 /* We give all constants their own alias set. Perhaps redundant with
99 MEM_READONLY_P, but pre-dates it. */
101 static alias_set_type const_alias_set;
103 static const char *strip_reg_name (const char *);
104 static int contains_pointers_p (tree);
105 #ifdef ASM_OUTPUT_EXTERNAL
106 static bool incorporeal_function_p (tree);
107 #endif
108 static void decode_addr_const (tree, struct addr_const *);
109 static hashval_t const_desc_hash (const void *);
110 static int const_desc_eq (const void *, const void *);
111 static hashval_t const_hash_1 (const tree);
112 static int compare_constant (const tree, const tree);
113 static tree copy_constant (tree);
114 static void output_constant_def_contents (rtx);
115 static void output_addressed_constants (tree);
116 static unsigned HOST_WIDE_INT array_size_for_constructor (tree);
117 static unsigned min_align (unsigned, unsigned);
118 static void output_constructor (tree, unsigned HOST_WIDE_INT, unsigned int);
119 static void globalize_decl (tree);
120 #ifdef BSS_SECTION_ASM_OP
121 #ifdef ASM_OUTPUT_BSS
122 static void asm_output_bss (FILE *, tree, const char *,
123 unsigned HOST_WIDE_INT, unsigned HOST_WIDE_INT);
124 #endif
125 #ifdef ASM_OUTPUT_ALIGNED_BSS
126 static void asm_output_aligned_bss (FILE *, tree, const char *,
127 unsigned HOST_WIDE_INT, int)
128 ATTRIBUTE_UNUSED;
129 #endif
130 #endif /* BSS_SECTION_ASM_OP */
131 static void mark_weak (tree);
132 static void output_constant_pool (const char *, tree);
134 /* Well-known sections, each one associated with some sort of *_ASM_OP. */
135 section *text_section;
136 section *data_section;
137 section *readonly_data_section;
138 section *sdata_section;
139 section *ctors_section;
140 section *dtors_section;
141 section *bss_section;
142 section *sbss_section;
144 /* Various forms of common section. All are guaranteed to be nonnull. */
145 section *tls_comm_section;
146 section *comm_section;
147 section *lcomm_section;
149 /* A SECTION_NOSWITCH section used for declaring global BSS variables.
150 May be null. */
151 section *bss_noswitch_section;
153 /* The section that holds the main exception table, when known. The section
154 is set either by the target's init_sections hook or by the first call to
155 switch_to_exception_section. */
156 section *exception_section;
158 /* The section that holds the DWARF2 frame unwind information, when known.
159 The section is set either by the target's init_sections hook or by the
160 first call to switch_to_eh_frame_section. */
161 section *eh_frame_section;
163 /* asm_out_file's current section. This is NULL if no section has yet
164 been selected or if we lose track of what the current section is. */
165 section *in_section;
167 /* True if code for the current function is currently being directed
168 at the cold section. */
169 bool in_cold_section_p;
171 /* A linked list of all the unnamed sections. */
172 static GTY(()) section *unnamed_sections;
174 /* Return a nonzero value if DECL has a section attribute. */
175 #ifndef IN_NAMED_SECTION
176 #define IN_NAMED_SECTION(DECL) \
177 ((TREE_CODE (DECL) == FUNCTION_DECL || TREE_CODE (DECL) == VAR_DECL) \
178 && DECL_SECTION_NAME (DECL) != NULL_TREE)
179 #endif
181 /* Hash table of named sections. */
182 static GTY((param_is (section))) htab_t section_htab;
184 /* A table of object_blocks, indexed by section. */
185 static GTY((param_is (struct object_block))) htab_t object_block_htab;
187 /* The next number to use for internal anchor labels. */
188 static GTY(()) int anchor_labelno;
190 /* A pool of constants that can be shared between functions. */
191 static GTY(()) struct rtx_constant_pool *shared_constant_pool;
193 /* TLS emulation. */
195 static GTY ((if_marked ("tree_map_marked_p"), param_is (struct tree_map)))
196 htab_t emutls_htab;
197 static GTY (()) tree emutls_object_type;
198 /* Emulated TLS objects have the TLS model TLS_MODEL_EMULATED. This
199 macro can be used on them to distinguish the control variable from
200 the initialization template. */
201 #define DECL_EMUTLS_VAR_P(D) (TREE_TYPE (D) == emutls_object_type)
203 #if !defined (NO_DOT_IN_LABEL)
204 # define EMUTLS_SEPARATOR "."
205 #elif !defined (NO_DOLLAR_IN_LABEL)
206 # define EMUTLS_SEPARATOR "$"
207 #else
208 # define EMUTLS_SEPARATOR "_"
209 #endif
211 /* Create an IDENTIFIER_NODE by prefixing PREFIX to the
212 IDENTIFIER_NODE NAME's name. */
214 static tree
215 prefix_name (const char *prefix, tree name)
217 unsigned plen = strlen (prefix);
218 unsigned nlen = strlen (IDENTIFIER_POINTER (name));
219 char *toname = (char *) alloca (plen + nlen + 1);
221 memcpy (toname, prefix, plen);
222 memcpy (toname + plen, IDENTIFIER_POINTER (name), nlen + 1);
224 return get_identifier (toname);
227 /* Create an identifier for the struct __emutls_object, given an identifier
228 of the DECL_ASSEMBLY_NAME of the original object. */
230 static tree
231 get_emutls_object_name (tree name)
233 const char *prefix = (targetm.emutls.var_prefix
234 ? targetm.emutls.var_prefix
235 : "__emutls_v" EMUTLS_SEPARATOR);
236 return prefix_name (prefix, name);
239 tree
240 default_emutls_var_fields (tree type, tree *name ATTRIBUTE_UNUSED)
242 tree word_type_node, field, next_field;
244 field = build_decl (FIELD_DECL, get_identifier ("__templ"), ptr_type_node);
245 DECL_CONTEXT (field) = type;
246 next_field = field;
248 field = build_decl (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 (FIELD_DECL, get_identifier ("__align"),
256 word_type_node);
257 DECL_CONTEXT (field) = type;
258 TREE_CHAIN (field) = next_field;
259 next_field = field;
261 field = build_decl (FIELD_DECL, get_identifier ("__size"), word_type_node);
262 DECL_CONTEXT (field) = type;
263 TREE_CHAIN (field) = next_field;
265 return field;
268 /* Create the structure for struct __emutls_object. This should match the
269 structure at the top of emutls.c, modulo the union there. */
271 static tree
272 get_emutls_object_type (void)
274 tree type, type_name, field;
276 type = emutls_object_type;
277 if (type)
278 return type;
280 emutls_object_type = type = lang_hooks.types.make_type (RECORD_TYPE);
281 type_name = NULL;
282 field = targetm.emutls.var_fields (type, &type_name);
283 if (!type_name)
284 type_name = get_identifier ("__emutls_object");
285 type_name = build_decl (TYPE_DECL, type_name, type);
286 TYPE_NAME (type) = type_name;
287 TYPE_FIELDS (type) = field;
288 layout_type (type);
290 return type;
293 /* Create a read-only variable like DECL, with the same DECL_INITIAL.
294 This will be used for initializing the emulated tls data area. */
296 static tree
297 get_emutls_init_templ_addr (tree decl)
299 tree name, to;
301 if (targetm.emutls.register_common && !DECL_INITIAL (decl)
302 && !DECL_SECTION_NAME (decl))
303 return null_pointer_node;
305 name = DECL_ASSEMBLER_NAME (decl);
306 if (!targetm.emutls.tmpl_prefix || targetm.emutls.tmpl_prefix[0])
308 const char *prefix = (targetm.emutls.tmpl_prefix
309 ? targetm.emutls.tmpl_prefix
310 : "__emutls_t" EMUTLS_SEPARATOR);
311 name = prefix_name (prefix, name);
314 to = build_decl (VAR_DECL, name, TREE_TYPE (decl));
315 SET_DECL_ASSEMBLER_NAME (to, DECL_NAME (to));
316 DECL_TLS_MODEL (to) = TLS_MODEL_EMULATED;
317 DECL_ARTIFICIAL (to) = 1;
318 TREE_USED (to) = TREE_USED (decl);
319 TREE_READONLY (to) = 1;
320 DECL_IGNORED_P (to) = 1;
321 DECL_CONTEXT (to) = DECL_CONTEXT (decl);
322 DECL_SECTION_NAME (to) = DECL_SECTION_NAME (decl);
324 DECL_WEAK (to) = DECL_WEAK (decl);
325 if (DECL_ONE_ONLY (decl))
327 make_decl_one_only (to);
328 TREE_STATIC (to) = TREE_STATIC (decl);
329 TREE_PUBLIC (to) = TREE_PUBLIC (decl);
330 DECL_VISIBILITY (to) = DECL_VISIBILITY (decl);
332 else
333 TREE_STATIC (to) = 1;
335 DECL_INITIAL (to) = DECL_INITIAL (decl);
336 DECL_INITIAL (decl) = NULL;
338 varpool_finalize_decl (to);
339 return build_fold_addr_expr (to);
342 /* When emulating tls, we use a control structure for use by the runtime.
343 Create and return this structure. */
345 tree
346 emutls_decl (tree decl)
348 tree name, to;
349 struct tree_map *h, in;
350 void **loc;
352 if (targetm.have_tls || decl == NULL || decl == error_mark_node
353 || TREE_CODE (decl) != VAR_DECL || ! DECL_THREAD_LOCAL_P (decl))
354 return decl;
356 /* Look up the object in the hash; return the control structure if
357 it has already been created. */
358 if (! emutls_htab)
359 emutls_htab = htab_create_ggc (512, tree_map_hash, tree_map_eq, 0);
361 name = DECL_ASSEMBLER_NAME (decl);
363 /* Note that we use the hash of the decl's name, rather than a hash
364 of the decl's pointer. In emutls_finish we iterate through the
365 hash table, and we want this traversal to be predictable. */
366 in.hash = htab_hash_string (IDENTIFIER_POINTER (name));
367 in.base.from = decl;
368 loc = htab_find_slot_with_hash (emutls_htab, &in, in.hash, INSERT);
369 h = (struct tree_map *) *loc;
370 if (h != NULL)
371 to = h->to;
372 else
374 to = build_decl (VAR_DECL, get_emutls_object_name (name),
375 get_emutls_object_type ());
377 h = GGC_NEW (struct tree_map);
378 h->hash = in.hash;
379 h->base.from = decl;
380 h->to = to;
381 *(struct tree_map **) loc = h;
383 DECL_TLS_MODEL (to) = TLS_MODEL_EMULATED;
384 DECL_ARTIFICIAL (to) = 1;
385 DECL_IGNORED_P (to) = 1;
386 TREE_READONLY (to) = 0;
387 SET_DECL_ASSEMBLER_NAME (to, DECL_NAME (to));
388 if (DECL_ONE_ONLY (decl))
389 make_decl_one_only (to);
390 DECL_CONTEXT (to) = DECL_CONTEXT (decl);
391 if (targetm.emutls.var_align_fixed)
392 /* If we're not allowed to change the proxy object's
393 alignment, pretend it's been set by the user. */
394 DECL_USER_ALIGN (to) = 1;
397 /* Note that these fields may need to be updated from time to time from
398 the original decl. Consider:
399 extern __thread int i;
400 int foo() { return i; }
401 __thread int i = 1;
402 in which I goes from external to locally defined and initialized. */
404 TREE_STATIC (to) = TREE_STATIC (decl);
405 TREE_USED (to) = TREE_USED (decl);
406 TREE_PUBLIC (to) = TREE_PUBLIC (decl);
407 DECL_EXTERNAL (to) = DECL_EXTERNAL (decl);
408 DECL_COMMON (to) = DECL_COMMON (decl);
409 DECL_WEAK (to) = DECL_WEAK (decl);
410 DECL_VISIBILITY (to) = DECL_VISIBILITY (decl);
412 return to;
415 static int
416 emutls_common_1 (void **loc, void *xstmts)
418 struct tree_map *h = *(struct tree_map **) loc;
419 tree args, x, *pstmts = (tree *) xstmts;
420 tree word_type_node;
422 if (! DECL_COMMON (h->base.from)
423 || (DECL_INITIAL (h->base.from)
424 && DECL_INITIAL (h->base.from) != error_mark_node))
425 return 1;
427 word_type_node = lang_hooks.types.type_for_mode (word_mode, 1);
429 /* The idea was to call get_emutls_init_templ_addr here, but if we
430 do this and there is an initializer, -fanchor_section loses,
431 because it would be too late to ensure the template is
432 output. */
433 x = null_pointer_node;
434 args = tree_cons (NULL, x, NULL);
435 x = build_int_cst (word_type_node, DECL_ALIGN_UNIT (h->base.from));
436 args = tree_cons (NULL, x, args);
437 x = fold_convert (word_type_node, DECL_SIZE_UNIT (h->base.from));
438 args = tree_cons (NULL, x, args);
439 x = build_fold_addr_expr (h->to);
440 args = tree_cons (NULL, x, args);
442 x = built_in_decls[BUILT_IN_EMUTLS_REGISTER_COMMON];
443 x = build_function_call_expr (x, args);
445 append_to_statement_list (x, pstmts);
446 return 1;
449 void
450 emutls_finish (void)
452 if (targetm.emutls.register_common)
454 tree body = NULL_TREE;
456 if (emutls_htab == NULL)
457 return;
459 htab_traverse_noresize (emutls_htab, emutls_common_1, &body);
460 if (body == NULL_TREE)
461 return;
463 cgraph_build_static_cdtor ('I', body, DEFAULT_INIT_PRIORITY);
467 /* Helper routines for maintaining section_htab. */
469 static int
470 section_entry_eq (const void *p1, const void *p2)
472 const section *old = (const section *) p1;
473 const char *new_name = (const char *) p2;
475 return strcmp (old->named.name, new_name) == 0;
478 static hashval_t
479 section_entry_hash (const void *p)
481 const section *old = (const section *) p;
482 return htab_hash_string (old->named.name);
485 /* Return a hash value for section SECT. */
487 static hashval_t
488 hash_section (section *sect)
490 if (sect->common.flags & SECTION_NAMED)
491 return htab_hash_string (sect->named.name);
492 return sect->common.flags;
495 /* Helper routines for maintaining object_block_htab. */
497 static int
498 object_block_entry_eq (const void *p1, const void *p2)
500 const struct object_block *old = (const struct object_block *) p1;
501 const section *new_section = (const section *) p2;
503 return old->sect == new_section;
506 static hashval_t
507 object_block_entry_hash (const void *p)
509 const struct object_block *old = (const struct object_block *) p;
510 return hash_section (old->sect);
513 /* Return a new unnamed section with the given fields. */
515 section *
516 get_unnamed_section (unsigned int flags, void (*callback) (const void *),
517 const void *data)
519 section *sect;
521 sect = GGC_NEW (section);
522 sect->unnamed.common.flags = flags | SECTION_UNNAMED;
523 sect->unnamed.callback = callback;
524 sect->unnamed.data = data;
525 sect->unnamed.next = unnamed_sections;
527 unnamed_sections = sect;
528 return sect;
531 /* Return a SECTION_NOSWITCH section with the given fields. */
533 static section *
534 get_noswitch_section (unsigned int flags, noswitch_section_callback callback)
536 section *sect;
538 sect = GGC_NEW (section);
539 sect->noswitch.common.flags = flags | SECTION_NOSWITCH;
540 sect->noswitch.callback = callback;
542 return sect;
545 /* Return the named section structure associated with NAME. Create
546 a new section with the given fields if no such structure exists. */
548 section *
549 get_section (const char *name, unsigned int flags, tree decl)
551 section *sect, **slot;
553 slot = (section **)
554 htab_find_slot_with_hash (section_htab, name,
555 htab_hash_string (name), INSERT);
556 flags |= SECTION_NAMED;
557 if (*slot == NULL)
559 sect = GGC_NEW (section);
560 sect->named.common.flags = flags;
561 sect->named.name = ggc_strdup (name);
562 sect->named.decl = decl;
563 *slot = sect;
565 else
567 sect = *slot;
568 if ((sect->common.flags & ~SECTION_DECLARED) != flags
569 && ((sect->common.flags | flags) & SECTION_OVERRIDE) == 0)
571 /* Sanity check user variables for flag changes. */
572 if (decl == 0)
573 decl = sect->named.decl;
574 gcc_assert (decl);
575 error ("%+D causes a section type conflict", decl);
578 return sect;
581 /* Return true if the current compilation mode benefits from having
582 objects grouped into blocks. */
584 static bool
585 use_object_blocks_p (void)
587 return flag_section_anchors;
590 /* Return the object_block structure for section SECT. Create a new
591 structure if we haven't created one already. Return null if SECT
592 itself is null. */
594 static struct object_block *
595 get_block_for_section (section *sect)
597 struct object_block *block;
598 void **slot;
600 if (sect == NULL)
601 return NULL;
603 slot = htab_find_slot_with_hash (object_block_htab, sect,
604 hash_section (sect), INSERT);
605 block = (struct object_block *) *slot;
606 if (block == NULL)
608 block = (struct object_block *)
609 ggc_alloc_cleared (sizeof (struct object_block));
610 block->sect = sect;
611 *slot = block;
613 return block;
616 /* Create a symbol with label LABEL and place it at byte offset
617 OFFSET in BLOCK. OFFSET can be negative if the symbol's offset
618 is not yet known. LABEL must be a garbage-collected string. */
620 static rtx
621 create_block_symbol (const char *label, struct object_block *block,
622 HOST_WIDE_INT offset)
624 rtx symbol;
625 unsigned int size;
627 /* Create the extended SYMBOL_REF. */
628 size = RTX_HDR_SIZE + sizeof (struct block_symbol);
629 symbol = (rtx) ggc_alloc_zone (size, &rtl_zone);
631 /* Initialize the normal SYMBOL_REF fields. */
632 memset (symbol, 0, size);
633 PUT_CODE (symbol, SYMBOL_REF);
634 PUT_MODE (symbol, Pmode);
635 XSTR (symbol, 0) = label;
636 SYMBOL_REF_FLAGS (symbol) = SYMBOL_FLAG_HAS_BLOCK_INFO;
638 /* Initialize the block_symbol stuff. */
639 SYMBOL_REF_BLOCK (symbol) = block;
640 SYMBOL_REF_BLOCK_OFFSET (symbol) = offset;
642 return symbol;
645 static void
646 initialize_cold_section_name (void)
648 const char *stripped_name;
649 char *name, *buffer;
650 tree dsn;
652 gcc_assert (cfun && current_function_decl);
653 if (crtl->subsections.unlikely_text_section_name)
654 return;
656 dsn = DECL_SECTION_NAME (current_function_decl);
657 if (flag_function_sections && dsn)
659 name = (char *) alloca (TREE_STRING_LENGTH (dsn) + 1);
660 memcpy (name, TREE_STRING_POINTER (dsn), TREE_STRING_LENGTH (dsn) + 1);
662 stripped_name = targetm.strip_name_encoding (name);
664 buffer = ACONCAT ((stripped_name, "_unlikely", NULL));
665 crtl->subsections.unlikely_text_section_name = ggc_strdup (buffer);
667 else
668 crtl->subsections.unlikely_text_section_name = UNLIKELY_EXECUTED_TEXT_SECTION_NAME;
671 /* Tell assembler to switch to unlikely-to-be-executed text section. */
673 section *
674 unlikely_text_section (void)
676 if (cfun)
678 if (!crtl->subsections.unlikely_text_section_name)
679 initialize_cold_section_name ();
681 return get_named_section (NULL, crtl->subsections.unlikely_text_section_name, 0);
683 else
684 return get_named_section (NULL, UNLIKELY_EXECUTED_TEXT_SECTION_NAME, 0);
687 /* When called within a function context, return true if the function
688 has been assigned a cold text section and if SECT is that section.
689 When called outside a function context, return true if SECT is the
690 default cold section. */
692 bool
693 unlikely_text_section_p (section *sect)
695 const char *name;
697 if (cfun)
698 name = crtl->subsections.unlikely_text_section_name;
699 else
700 name = UNLIKELY_EXECUTED_TEXT_SECTION_NAME;
702 return (name
703 && sect
704 && SECTION_STYLE (sect) == SECTION_NAMED
705 && strcmp (name, sect->named.name) == 0);
708 /* Return a section with a particular name and with whatever SECTION_*
709 flags section_type_flags deems appropriate. The name of the section
710 is taken from NAME if nonnull, otherwise it is taken from DECL's
711 DECL_SECTION_NAME. DECL is the decl associated with the section
712 (see the section comment for details) and RELOC is as for
713 section_type_flags. */
715 section *
716 get_named_section (tree decl, const char *name, int reloc)
718 unsigned int flags;
720 gcc_assert (!decl || DECL_P (decl));
721 if (name == NULL)
722 name = TREE_STRING_POINTER (DECL_SECTION_NAME (decl));
724 flags = targetm.section_type_flags (decl, name, reloc);
726 return get_section (name, flags, decl);
729 /* If required, set DECL_SECTION_NAME to a unique name. */
731 void
732 resolve_unique_section (tree decl, int reloc ATTRIBUTE_UNUSED,
733 int flag_function_or_data_sections)
735 if (DECL_SECTION_NAME (decl) == NULL_TREE
736 && targetm.have_named_sections
737 && (flag_function_or_data_sections
738 || DECL_ONE_ONLY (decl)))
739 targetm.asm_out.unique_section (decl, reloc);
742 #ifdef BSS_SECTION_ASM_OP
744 #ifdef ASM_OUTPUT_BSS
746 /* Utility function for ASM_OUTPUT_BSS for targets to use if
747 they don't support alignments in .bss.
748 ??? It is believed that this function will work in most cases so such
749 support is localized here. */
751 static void
752 asm_output_bss (FILE *file, tree decl ATTRIBUTE_UNUSED,
753 const char *name,
754 unsigned HOST_WIDE_INT size ATTRIBUTE_UNUSED,
755 unsigned HOST_WIDE_INT rounded)
757 gcc_assert (strcmp (XSTR (XEXP (DECL_RTL (decl), 0), 0), name) == 0);
758 targetm.asm_out.globalize_decl_name (file, decl);
759 switch_to_section (bss_section);
760 #ifdef ASM_DECLARE_OBJECT_NAME
761 last_assemble_variable_decl = decl;
762 ASM_DECLARE_OBJECT_NAME (file, name, decl);
763 #else
764 /* Standard thing is just output label for the object. */
765 ASM_OUTPUT_LABEL (file, name);
766 #endif /* ASM_DECLARE_OBJECT_NAME */
767 ASM_OUTPUT_SKIP (file, rounded ? rounded : 1);
770 #endif
772 #ifdef ASM_OUTPUT_ALIGNED_BSS
774 /* Utility function for targets to use in implementing
775 ASM_OUTPUT_ALIGNED_BSS.
776 ??? It is believed that this function will work in most cases so such
777 support is localized here. */
779 static void
780 asm_output_aligned_bss (FILE *file, tree decl ATTRIBUTE_UNUSED,
781 const char *name, unsigned HOST_WIDE_INT size,
782 int align)
784 switch_to_section (bss_section);
785 ASM_OUTPUT_ALIGN (file, floor_log2 (align / BITS_PER_UNIT));
786 #ifdef ASM_DECLARE_OBJECT_NAME
787 last_assemble_variable_decl = decl;
788 ASM_DECLARE_OBJECT_NAME (file, name, decl);
789 #else
790 /* Standard thing is just output label for the object. */
791 ASM_OUTPUT_LABEL (file, name);
792 #endif /* ASM_DECLARE_OBJECT_NAME */
793 ASM_OUTPUT_SKIP (file, size ? size : 1);
796 #endif
798 #endif /* BSS_SECTION_ASM_OP */
800 #ifndef USE_SELECT_SECTION_FOR_FUNCTIONS
801 /* Return the hot section for function DECL. Return text_section for
802 null DECLs. */
804 static section *
805 hot_function_section (tree decl)
807 if (decl != NULL_TREE
808 && DECL_SECTION_NAME (decl) != NULL_TREE
809 && targetm.have_named_sections)
810 return get_named_section (decl, NULL, 0);
811 else
812 return text_section;
814 #endif
816 /* Return the section for function DECL.
818 If DECL is NULL_TREE, return the text section. We can be passed
819 NULL_TREE under some circumstances by dbxout.c at least. */
821 section *
822 function_section (tree decl)
824 int reloc = 0;
826 if (first_function_block_is_cold)
827 reloc = 1;
829 #ifdef USE_SELECT_SECTION_FOR_FUNCTIONS
830 if (decl != NULL_TREE
831 && DECL_SECTION_NAME (decl) != NULL_TREE)
832 return reloc ? unlikely_text_section ()
833 : get_named_section (decl, NULL, 0);
834 else
835 return targetm.asm_out.select_section (decl, reloc, DECL_ALIGN (decl));
836 #else
837 return reloc ? unlikely_text_section () : hot_function_section (decl);
838 #endif
841 section *
842 current_function_section (void)
844 #ifdef USE_SELECT_SECTION_FOR_FUNCTIONS
845 if (current_function_decl != NULL_TREE
846 && DECL_SECTION_NAME (current_function_decl) != NULL_TREE)
847 return in_cold_section_p ? unlikely_text_section ()
848 : get_named_section (current_function_decl,
849 NULL, 0);
850 else
851 return targetm.asm_out.select_section (current_function_decl,
852 in_cold_section_p,
853 DECL_ALIGN (current_function_decl));
854 #else
855 return (in_cold_section_p
856 ? unlikely_text_section ()
857 : hot_function_section (current_function_decl));
858 #endif
861 /* Return the read-only data section associated with function DECL. */
863 section *
864 default_function_rodata_section (tree decl)
866 if (decl != NULL_TREE && DECL_SECTION_NAME (decl))
868 const char *name = TREE_STRING_POINTER (DECL_SECTION_NAME (decl));
870 if (DECL_ONE_ONLY (decl) && HAVE_COMDAT_GROUP)
872 size_t len = strlen (name) + 3;
873 char* rname = (char *) alloca (len);
875 strcpy (rname, ".rodata");
876 strcat (rname, name + 5);
877 return get_section (rname, SECTION_LINKONCE, decl);
879 /* For .gnu.linkonce.t.foo we want to use .gnu.linkonce.r.foo. */
880 else if (DECL_ONE_ONLY (decl)
881 && strncmp (name, ".gnu.linkonce.t.", 16) == 0)
883 size_t len = strlen (name) + 1;
884 char *rname = (char *) alloca (len);
886 memcpy (rname, name, len);
887 rname[14] = 'r';
888 return get_section (rname, SECTION_LINKONCE, decl);
890 /* For .text.foo we want to use .rodata.foo. */
891 else if (flag_function_sections && flag_data_sections
892 && strncmp (name, ".text.", 6) == 0)
894 size_t len = strlen (name) + 1;
895 char *rname = (char *) alloca (len + 2);
897 memcpy (rname, ".rodata", 7);
898 memcpy (rname + 7, name + 5, len - 5);
899 return get_section (rname, 0, decl);
903 return readonly_data_section;
906 /* Return the read-only data section associated with function DECL
907 for targets where that section should be always the single
908 readonly data section. */
910 section *
911 default_no_function_rodata_section (tree decl ATTRIBUTE_UNUSED)
913 return readonly_data_section;
916 /* Return the section to use for string merging. */
918 static section *
919 mergeable_string_section (tree decl ATTRIBUTE_UNUSED,
920 unsigned HOST_WIDE_INT align ATTRIBUTE_UNUSED,
921 unsigned int flags ATTRIBUTE_UNUSED)
923 HOST_WIDE_INT len;
925 if (HAVE_GAS_SHF_MERGE && flag_merge_constants
926 && TREE_CODE (decl) == STRING_CST
927 && TREE_CODE (TREE_TYPE (decl)) == ARRAY_TYPE
928 && align <= 256
929 && (len = int_size_in_bytes (TREE_TYPE (decl))) > 0
930 && TREE_STRING_LENGTH (decl) >= len)
932 enum machine_mode mode;
933 unsigned int modesize;
934 const char *str;
935 HOST_WIDE_INT i;
936 int j, unit;
937 char name[30];
939 mode = TYPE_MODE (TREE_TYPE (TREE_TYPE (decl)));
940 modesize = GET_MODE_BITSIZE (mode);
941 if (modesize >= 8 && modesize <= 256
942 && (modesize & (modesize - 1)) == 0)
944 if (align < modesize)
945 align = modesize;
947 str = TREE_STRING_POINTER (decl);
948 unit = GET_MODE_SIZE (mode);
950 /* Check for embedded NUL characters. */
951 for (i = 0; i < len; i += unit)
953 for (j = 0; j < unit; j++)
954 if (str[i + j] != '\0')
955 break;
956 if (j == unit)
957 break;
959 if (i == len - unit)
961 sprintf (name, ".rodata.str%d.%d", modesize / 8,
962 (int) (align / 8));
963 flags |= (modesize / 8) | SECTION_MERGE | SECTION_STRINGS;
964 return get_section (name, flags, NULL);
969 return readonly_data_section;
972 /* Return the section to use for constant merging. */
974 section *
975 mergeable_constant_section (enum machine_mode mode ATTRIBUTE_UNUSED,
976 unsigned HOST_WIDE_INT align ATTRIBUTE_UNUSED,
977 unsigned int flags ATTRIBUTE_UNUSED)
979 unsigned int modesize = GET_MODE_BITSIZE (mode);
981 if (HAVE_GAS_SHF_MERGE && flag_merge_constants
982 && mode != VOIDmode
983 && mode != BLKmode
984 && modesize <= align
985 && align >= 8
986 && align <= 256
987 && (align & (align - 1)) == 0)
989 char name[24];
991 sprintf (name, ".rodata.cst%d", (int) (align / 8));
992 flags |= (align / 8) | SECTION_MERGE;
993 return get_section (name, flags, NULL);
995 return readonly_data_section;
998 /* Given NAME, a putative register name, discard any customary prefixes. */
1000 static const char *
1001 strip_reg_name (const char *name)
1003 #ifdef REGISTER_PREFIX
1004 if (!strncmp (name, REGISTER_PREFIX, strlen (REGISTER_PREFIX)))
1005 name += strlen (REGISTER_PREFIX);
1006 #endif
1007 if (name[0] == '%' || name[0] == '#')
1008 name++;
1009 return name;
1012 /* The user has asked for a DECL to have a particular name. Set (or
1013 change) it in such a way that we don't prefix an underscore to
1014 it. */
1015 void
1016 set_user_assembler_name (tree decl, const char *name)
1018 char *starred = (char *) alloca (strlen (name) + 2);
1019 starred[0] = '*';
1020 strcpy (starred + 1, name);
1021 change_decl_assembler_name (decl, get_identifier (starred));
1022 SET_DECL_RTL (decl, NULL_RTX);
1025 /* Decode an `asm' spec for a declaration as a register name.
1026 Return the register number, or -1 if nothing specified,
1027 or -2 if the ASMSPEC is not `cc' or `memory' and is not recognized,
1028 or -3 if ASMSPEC is `cc' and is not recognized,
1029 or -4 if ASMSPEC is `memory' and is not recognized.
1030 Accept an exact spelling or a decimal number.
1031 Prefixes such as % are optional. */
1034 decode_reg_name (const char *asmspec)
1036 if (asmspec != 0)
1038 int i;
1040 /* Get rid of confusing prefixes. */
1041 asmspec = strip_reg_name (asmspec);
1043 /* Allow a decimal number as a "register name". */
1044 for (i = strlen (asmspec) - 1; i >= 0; i--)
1045 if (! ISDIGIT (asmspec[i]))
1046 break;
1047 if (asmspec[0] != 0 && i < 0)
1049 i = atoi (asmspec);
1050 if (i < FIRST_PSEUDO_REGISTER && i >= 0)
1051 return i;
1052 else
1053 return -2;
1056 for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
1057 if (reg_names[i][0]
1058 && ! strcmp (asmspec, strip_reg_name (reg_names[i])))
1059 return i;
1061 #ifdef ADDITIONAL_REGISTER_NAMES
1063 static const struct { const char *const name; const int number; } table[]
1064 = ADDITIONAL_REGISTER_NAMES;
1066 for (i = 0; i < (int) ARRAY_SIZE (table); i++)
1067 if (table[i].name[0]
1068 && ! strcmp (asmspec, table[i].name))
1069 return table[i].number;
1071 #endif /* ADDITIONAL_REGISTER_NAMES */
1073 if (!strcmp (asmspec, "memory"))
1074 return -4;
1076 if (!strcmp (asmspec, "cc"))
1077 return -3;
1079 return -2;
1082 return -1;
1085 /* Return true if DECL's initializer is suitable for a BSS section. */
1087 static bool
1088 bss_initializer_p (const_tree decl)
1090 return (DECL_INITIAL (decl) == NULL
1091 || DECL_INITIAL (decl) == error_mark_node
1092 || (flag_zero_initialized_in_bss
1093 /* Leave constant zeroes in .rodata so they
1094 can be shared. */
1095 && !TREE_READONLY (decl)
1096 && initializer_zerop (DECL_INITIAL (decl))));
1099 /* Compute the alignment of variable specified by DECL.
1100 DONT_OUTPUT_DATA is from assemble_variable. */
1102 void
1103 align_variable (tree decl, bool dont_output_data)
1105 unsigned int align = DECL_ALIGN (decl);
1107 /* In the case for initialing an array whose length isn't specified,
1108 where we have not yet been able to do the layout,
1109 figure out the proper alignment now. */
1110 if (dont_output_data && DECL_SIZE (decl) == 0
1111 && TREE_CODE (TREE_TYPE (decl)) == ARRAY_TYPE)
1112 align = MAX (align, TYPE_ALIGN (TREE_TYPE (TREE_TYPE (decl))));
1114 /* Some object file formats have a maximum alignment which they support.
1115 In particular, a.out format supports a maximum alignment of 4. */
1116 if (align > MAX_OFILE_ALIGNMENT)
1118 warning (0, "alignment of %q+D is greater than maximum object "
1119 "file alignment. Using %d", decl,
1120 MAX_OFILE_ALIGNMENT/BITS_PER_UNIT);
1121 align = MAX_OFILE_ALIGNMENT;
1124 /* On some machines, it is good to increase alignment sometimes. */
1125 if (! DECL_USER_ALIGN (decl))
1127 #ifdef DATA_ALIGNMENT
1128 unsigned int data_align = DATA_ALIGNMENT (TREE_TYPE (decl), align);
1129 /* Don't increase alignment too much for TLS variables - TLS space
1130 is too precious. */
1131 if (! DECL_THREAD_LOCAL_P (decl) || data_align <= BITS_PER_WORD)
1132 align = data_align;
1133 #endif
1134 #ifdef CONSTANT_ALIGNMENT
1135 if (DECL_INITIAL (decl) != 0 && DECL_INITIAL (decl) != error_mark_node)
1137 unsigned int const_align = CONSTANT_ALIGNMENT (DECL_INITIAL (decl),
1138 align);
1139 /* Don't increase alignment too much for TLS variables - TLS space
1140 is too precious. */
1141 if (! DECL_THREAD_LOCAL_P (decl) || const_align <= BITS_PER_WORD)
1142 align = const_align;
1144 #endif
1147 /* Reset the alignment in case we have made it tighter, so we can benefit
1148 from it in get_pointer_alignment. */
1149 DECL_ALIGN (decl) = align;
1152 /* Return the section into which the given VAR_DECL or CONST_DECL
1153 should be placed. PREFER_NOSWITCH_P is true if a noswitch
1154 section should be used wherever possible. */
1156 static section *
1157 get_variable_section (tree decl, bool prefer_noswitch_p)
1159 int reloc;
1161 /* If the decl has been given an explicit section name, then it
1162 isn't common, and shouldn't be handled as such. */
1163 if (DECL_COMMON (decl) && DECL_SECTION_NAME (decl) == NULL)
1165 if (DECL_THREAD_LOCAL_P (decl))
1166 return tls_comm_section;
1167 /* This cannot be common bss for an emulated TLS object without
1168 a register_common hook. */
1169 else if (DECL_TLS_MODEL (decl) == TLS_MODEL_EMULATED
1170 && !targetm.emutls.register_common)
1172 else if (TREE_PUBLIC (decl) && bss_initializer_p (decl))
1173 return comm_section;
1176 if (DECL_INITIAL (decl) == error_mark_node)
1177 reloc = contains_pointers_p (TREE_TYPE (decl)) ? 3 : 0;
1178 else if (DECL_INITIAL (decl))
1179 reloc = compute_reloc_for_constant (DECL_INITIAL (decl));
1180 else
1181 reloc = 0;
1183 resolve_unique_section (decl, reloc, flag_data_sections);
1184 if (IN_NAMED_SECTION (decl))
1185 return get_named_section (decl, NULL, reloc);
1187 if (!DECL_THREAD_LOCAL_P (decl)
1188 && !(prefer_noswitch_p && targetm.have_switchable_bss_sections)
1189 && bss_initializer_p (decl))
1191 if (!TREE_PUBLIC (decl))
1192 return lcomm_section;
1193 if (bss_noswitch_section)
1194 return bss_noswitch_section;
1197 return targetm.asm_out.select_section (decl, reloc, DECL_ALIGN (decl));
1200 /* Return the block into which object_block DECL should be placed. */
1202 static struct object_block *
1203 get_block_for_decl (tree decl)
1205 section *sect;
1207 if (TREE_CODE (decl) == VAR_DECL)
1209 /* The object must be defined in this translation unit. */
1210 if (DECL_EXTERNAL (decl))
1211 return NULL;
1213 /* There's no point using object blocks for something that is
1214 isolated by definition. */
1215 if (DECL_ONE_ONLY (decl))
1216 return NULL;
1219 /* We can only calculate block offsets if the decl has a known
1220 constant size. */
1221 if (DECL_SIZE_UNIT (decl) == NULL)
1222 return NULL;
1223 if (!host_integerp (DECL_SIZE_UNIT (decl), 1))
1224 return NULL;
1226 /* Find out which section should contain DECL. We cannot put it into
1227 an object block if it requires a standalone definition. */
1228 if (TREE_CODE (decl) == VAR_DECL)
1229 align_variable (decl, 0);
1230 sect = get_variable_section (decl, true);
1231 if (SECTION_STYLE (sect) == SECTION_NOSWITCH)
1232 return NULL;
1234 return get_block_for_section (sect);
1237 /* Make sure block symbol SYMBOL is in block BLOCK. */
1239 static void
1240 change_symbol_block (rtx symbol, struct object_block *block)
1242 if (block != SYMBOL_REF_BLOCK (symbol))
1244 gcc_assert (SYMBOL_REF_BLOCK_OFFSET (symbol) < 0);
1245 SYMBOL_REF_BLOCK (symbol) = block;
1249 /* Return true if it is possible to put DECL in an object_block. */
1251 static bool
1252 use_blocks_for_decl_p (tree decl)
1254 /* Only data DECLs can be placed into object blocks. */
1255 if (TREE_CODE (decl) != VAR_DECL && TREE_CODE (decl) != CONST_DECL)
1256 return false;
1258 /* Detect decls created by dw2_force_const_mem. Such decls are
1259 special because DECL_INITIAL doesn't specify the decl's true value.
1260 dw2_output_indirect_constants will instead call assemble_variable
1261 with dont_output_data set to 1 and then print the contents itself. */
1262 if (DECL_INITIAL (decl) == decl)
1263 return false;
1265 /* If this decl is an alias, then we don't want to emit a definition. */
1266 if (lookup_attribute ("alias", DECL_ATTRIBUTES (decl)))
1267 return false;
1269 return true;
1272 /* Create the DECL_RTL for a VAR_DECL or FUNCTION_DECL. DECL should
1273 have static storage duration. In other words, it should not be an
1274 automatic variable, including PARM_DECLs.
1276 There is, however, one exception: this function handles variables
1277 explicitly placed in a particular register by the user.
1279 This is never called for PARM_DECL nodes. */
1281 void
1282 make_decl_rtl (tree decl)
1284 const char *name = 0;
1285 int reg_number;
1286 rtx x;
1288 /* Check that we are not being given an automatic variable. */
1289 gcc_assert (TREE_CODE (decl) != PARM_DECL
1290 && TREE_CODE (decl) != RESULT_DECL);
1292 /* A weak alias has TREE_PUBLIC set but not the other bits. */
1293 gcc_assert (TREE_CODE (decl) != VAR_DECL
1294 || TREE_STATIC (decl)
1295 || TREE_PUBLIC (decl)
1296 || DECL_EXTERNAL (decl)
1297 || DECL_REGISTER (decl));
1299 /* And that we were not given a type or a label. */
1300 gcc_assert (TREE_CODE (decl) != TYPE_DECL
1301 && TREE_CODE (decl) != LABEL_DECL);
1303 /* For a duplicate declaration, we can be called twice on the
1304 same DECL node. Don't discard the RTL already made. */
1305 if (DECL_RTL_SET_P (decl))
1307 /* If the old RTL had the wrong mode, fix the mode. */
1308 x = DECL_RTL (decl);
1309 if (GET_MODE (x) != DECL_MODE (decl))
1310 SET_DECL_RTL (decl, adjust_address_nv (x, DECL_MODE (decl), 0));
1312 if (TREE_CODE (decl) != FUNCTION_DECL && DECL_REGISTER (decl))
1313 return;
1315 /* ??? Another way to do this would be to maintain a hashed
1316 table of such critters. Instead of adding stuff to a DECL
1317 to give certain attributes to it, we could use an external
1318 hash map from DECL to set of attributes. */
1320 /* Let the target reassign the RTL if it wants.
1321 This is necessary, for example, when one machine specific
1322 decl attribute overrides another. */
1323 targetm.encode_section_info (decl, DECL_RTL (decl), false);
1325 /* If the symbol has a SYMBOL_REF_BLOCK field, update it based
1326 on the new decl information. */
1327 if (MEM_P (x)
1328 && GET_CODE (XEXP (x, 0)) == SYMBOL_REF
1329 && SYMBOL_REF_HAS_BLOCK_INFO_P (XEXP (x, 0)))
1330 change_symbol_block (XEXP (x, 0), get_block_for_decl (decl));
1332 /* Make this function static known to the mudflap runtime. */
1333 if (flag_mudflap && TREE_CODE (decl) == VAR_DECL)
1334 mudflap_enqueue_decl (decl);
1336 return;
1339 name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
1341 if (name[0] != '*' && TREE_CODE (decl) != FUNCTION_DECL
1342 && DECL_REGISTER (decl))
1344 error ("register name not specified for %q+D", decl);
1346 else if (TREE_CODE (decl) != FUNCTION_DECL && DECL_REGISTER (decl))
1348 const char *asmspec = name+1;
1349 reg_number = decode_reg_name (asmspec);
1350 /* First detect errors in declaring global registers. */
1351 if (reg_number == -1)
1352 error ("register name not specified for %q+D", decl);
1353 else if (reg_number < 0)
1354 error ("invalid register name for %q+D", decl);
1355 else if (TYPE_MODE (TREE_TYPE (decl)) == BLKmode)
1356 error ("data type of %q+D isn%'t suitable for a register",
1357 decl);
1358 else if (! HARD_REGNO_MODE_OK (reg_number, TYPE_MODE (TREE_TYPE (decl))))
1359 error ("register specified for %q+D isn%'t suitable for data type",
1360 decl);
1361 /* Now handle properly declared static register variables. */
1362 else
1364 int nregs;
1366 if (DECL_INITIAL (decl) != 0 && TREE_STATIC (decl))
1368 DECL_INITIAL (decl) = 0;
1369 error ("global register variable has initial value");
1371 if (TREE_THIS_VOLATILE (decl))
1372 warning (OPT_Wvolatile_register_var,
1373 "optimization may eliminate reads and/or "
1374 "writes to register variables");
1376 /* If the user specified one of the eliminables registers here,
1377 e.g., FRAME_POINTER_REGNUM, we don't want to get this variable
1378 confused with that register and be eliminated. This usage is
1379 somewhat suspect... */
1381 SET_DECL_RTL (decl, gen_rtx_raw_REG (DECL_MODE (decl), reg_number));
1382 ORIGINAL_REGNO (DECL_RTL (decl)) = reg_number;
1383 REG_USERVAR_P (DECL_RTL (decl)) = 1;
1385 if (TREE_STATIC (decl))
1387 /* Make this register global, so not usable for anything
1388 else. */
1389 #ifdef ASM_DECLARE_REGISTER_GLOBAL
1390 name = IDENTIFIER_POINTER (DECL_NAME (decl));
1391 ASM_DECLARE_REGISTER_GLOBAL (asm_out_file, decl, reg_number, name);
1392 #endif
1393 nregs = hard_regno_nregs[reg_number][DECL_MODE (decl)];
1394 while (nregs > 0)
1395 globalize_reg (reg_number + --nregs);
1398 /* As a register variable, it has no section. */
1399 return;
1402 /* Now handle ordinary static variables and functions (in memory).
1403 Also handle vars declared register invalidly. */
1404 else if (name[0] == '*')
1406 #ifdef REGISTER_PREFIX
1407 if (strlen (REGISTER_PREFIX) != 0)
1409 reg_number = decode_reg_name (name);
1410 if (reg_number >= 0 || reg_number == -3)
1411 error ("register name given for non-register variable %q+D", decl);
1413 #endif
1416 /* Specifying a section attribute on a variable forces it into a
1417 non-.bss section, and thus it cannot be common. */
1418 if (TREE_CODE (decl) == VAR_DECL
1419 && DECL_SECTION_NAME (decl) != NULL_TREE
1420 && DECL_INITIAL (decl) == NULL_TREE
1421 && DECL_COMMON (decl))
1422 DECL_COMMON (decl) = 0;
1424 /* Variables can't be both common and weak. */
1425 if (TREE_CODE (decl) == VAR_DECL && DECL_WEAK (decl))
1426 DECL_COMMON (decl) = 0;
1428 if (use_object_blocks_p () && use_blocks_for_decl_p (decl))
1429 x = create_block_symbol (name, get_block_for_decl (decl), -1);
1430 else
1431 x = gen_rtx_SYMBOL_REF (Pmode, name);
1432 SYMBOL_REF_WEAK (x) = DECL_WEAK (decl);
1433 SET_SYMBOL_REF_DECL (x, decl);
1435 x = gen_rtx_MEM (DECL_MODE (decl), x);
1436 if (TREE_CODE (decl) != FUNCTION_DECL)
1437 set_mem_attributes (x, decl, 1);
1438 SET_DECL_RTL (decl, x);
1440 /* Optionally set flags or add text to the name to record information
1441 such as that it is a function name.
1442 If the name is changed, the macro ASM_OUTPUT_LABELREF
1443 will have to know how to strip this information. */
1444 targetm.encode_section_info (decl, DECL_RTL (decl), true);
1446 /* Make this function static known to the mudflap runtime. */
1447 if (flag_mudflap && TREE_CODE (decl) == VAR_DECL)
1448 mudflap_enqueue_decl (decl);
1451 /* Output a string of literal assembler code
1452 for an `asm' keyword used between functions. */
1454 void
1455 assemble_asm (tree string)
1457 app_enable ();
1459 if (TREE_CODE (string) == ADDR_EXPR)
1460 string = TREE_OPERAND (string, 0);
1462 fprintf (asm_out_file, "\t%s\n", TREE_STRING_POINTER (string));
1465 /* Record an element in the table of global destructors. SYMBOL is
1466 a SYMBOL_REF of the function to be called; PRIORITY is a number
1467 between 0 and MAX_INIT_PRIORITY. */
1469 void
1470 default_stabs_asm_out_destructor (rtx symbol ATTRIBUTE_UNUSED,
1471 int priority ATTRIBUTE_UNUSED)
1473 #if defined DBX_DEBUGGING_INFO || defined XCOFF_DEBUGGING_INFO
1474 /* Tell GNU LD that this is part of the static destructor set.
1475 This will work for any system that uses stabs, most usefully
1476 aout systems. */
1477 dbxout_begin_simple_stabs ("___DTOR_LIST__", 22 /* N_SETT */);
1478 dbxout_stab_value_label (XSTR (symbol, 0));
1479 #else
1480 sorry ("global destructors not supported on this target");
1481 #endif
1484 /* Write the address of the entity given by SYMBOL to SEC. */
1485 void
1486 assemble_addr_to_section (rtx symbol, section *sec)
1488 switch_to_section (sec);
1489 assemble_align (POINTER_SIZE);
1490 assemble_integer (symbol, POINTER_SIZE / BITS_PER_UNIT, POINTER_SIZE, 1);
1493 /* Return the numbered .ctors.N (if CONSTRUCTOR_P) or .dtors.N (if
1494 not) section for PRIORITY. */
1495 section *
1496 get_cdtor_priority_section (int priority, bool constructor_p)
1498 char buf[16];
1500 /* ??? This only works reliably with the GNU linker. */
1501 sprintf (buf, "%s.%.5u",
1502 constructor_p ? ".ctors" : ".dtors",
1503 /* Invert the numbering so the linker puts us in the proper
1504 order; constructors are run from right to left, and the
1505 linker sorts in increasing order. */
1506 MAX_INIT_PRIORITY - priority);
1507 return get_section (buf, SECTION_WRITE, NULL);
1510 void
1511 default_named_section_asm_out_destructor (rtx symbol, int priority)
1513 section *sec;
1515 if (priority != DEFAULT_INIT_PRIORITY)
1516 sec = get_cdtor_priority_section (priority,
1517 /*constructor_p=*/false);
1518 else
1519 sec = get_section (".dtors", SECTION_WRITE, NULL);
1521 assemble_addr_to_section (symbol, sec);
1524 #ifdef DTORS_SECTION_ASM_OP
1525 void
1526 default_dtor_section_asm_out_destructor (rtx symbol,
1527 int priority ATTRIBUTE_UNUSED)
1529 assemble_addr_to_section (symbol, dtors_section);
1531 #endif
1533 /* Likewise for global constructors. */
1535 void
1536 default_stabs_asm_out_constructor (rtx symbol ATTRIBUTE_UNUSED,
1537 int priority ATTRIBUTE_UNUSED)
1539 #if defined DBX_DEBUGGING_INFO || defined XCOFF_DEBUGGING_INFO
1540 /* Tell GNU LD that this is part of the static destructor set.
1541 This will work for any system that uses stabs, most usefully
1542 aout systems. */
1543 dbxout_begin_simple_stabs ("___CTOR_LIST__", 22 /* N_SETT */);
1544 dbxout_stab_value_label (XSTR (symbol, 0));
1545 #else
1546 sorry ("global constructors not supported on this target");
1547 #endif
1550 void
1551 default_named_section_asm_out_constructor (rtx symbol, int priority)
1553 section *sec;
1555 if (priority != DEFAULT_INIT_PRIORITY)
1556 sec = get_cdtor_priority_section (priority,
1557 /*constructor_p=*/true);
1558 else
1559 sec = get_section (".ctors", SECTION_WRITE, NULL);
1561 assemble_addr_to_section (symbol, sec);
1564 #ifdef CTORS_SECTION_ASM_OP
1565 void
1566 default_ctor_section_asm_out_constructor (rtx symbol,
1567 int priority ATTRIBUTE_UNUSED)
1569 assemble_addr_to_section (symbol, ctors_section);
1571 #endif
1573 /* CONSTANT_POOL_BEFORE_FUNCTION may be defined as an expression with
1574 a nonzero value if the constant pool should be output before the
1575 start of the function, or a zero value if the pool should output
1576 after the end of the function. The default is to put it before the
1577 start. */
1579 #ifndef CONSTANT_POOL_BEFORE_FUNCTION
1580 #define CONSTANT_POOL_BEFORE_FUNCTION 1
1581 #endif
1583 /* DECL is an object (either VAR_DECL or FUNCTION_DECL) which is going
1584 to be output to assembler.
1585 Set first_global_object_name and weak_global_object_name as appropriate. */
1587 void
1588 notice_global_symbol (tree decl)
1590 const char **type = &first_global_object_name;
1592 if (first_global_object_name
1593 || !TREE_PUBLIC (decl)
1594 || DECL_EXTERNAL (decl)
1595 || !DECL_NAME (decl)
1596 || (TREE_CODE (decl) != FUNCTION_DECL
1597 && (TREE_CODE (decl) != VAR_DECL
1598 || (DECL_COMMON (decl)
1599 && (DECL_INITIAL (decl) == 0
1600 || DECL_INITIAL (decl) == error_mark_node))))
1601 || !MEM_P (DECL_RTL (decl)))
1602 return;
1604 /* We win when global object is found, but it is useful to know about weak
1605 symbol as well so we can produce nicer unique names. */
1606 if (DECL_WEAK (decl) || DECL_ONE_ONLY (decl) || flag_shlib)
1607 type = &weak_global_object_name;
1609 if (!*type)
1611 const char *p;
1612 const char *name;
1613 rtx decl_rtl = DECL_RTL (decl);
1615 p = targetm.strip_name_encoding (XSTR (XEXP (decl_rtl, 0), 0));
1616 name = ggc_strdup (p);
1618 *type = name;
1622 /* Output assembler code for the constant pool of a function and associated
1623 with defining the name of the function. DECL describes the function.
1624 NAME is the function's name. For the constant pool, we use the current
1625 constant pool data. */
1627 void
1628 assemble_start_function (tree decl, const char *fnname)
1630 int align;
1631 char tmp_label[100];
1632 bool hot_label_written = false;
1634 crtl->subsections.unlikely_text_section_name = NULL;
1636 first_function_block_is_cold = false;
1637 if (flag_reorder_blocks_and_partition)
1639 ASM_GENERATE_INTERNAL_LABEL (tmp_label, "LHOTB", const_labelno);
1640 crtl->subsections.hot_section_label = ggc_strdup (tmp_label);
1641 ASM_GENERATE_INTERNAL_LABEL (tmp_label, "LCOLDB", const_labelno);
1642 crtl->subsections.cold_section_label = ggc_strdup (tmp_label);
1643 ASM_GENERATE_INTERNAL_LABEL (tmp_label, "LHOTE", const_labelno);
1644 crtl->subsections.hot_section_end_label = ggc_strdup (tmp_label);
1645 ASM_GENERATE_INTERNAL_LABEL (tmp_label, "LCOLDE", const_labelno);
1646 crtl->subsections.cold_section_end_label = ggc_strdup (tmp_label);
1647 const_labelno++;
1649 else
1651 crtl->subsections.hot_section_label = NULL;
1652 crtl->subsections.cold_section_label = NULL;
1653 crtl->subsections.hot_section_end_label = NULL;
1654 crtl->subsections.cold_section_end_label = NULL;
1657 /* The following code does not need preprocessing in the assembler. */
1659 app_disable ();
1661 if (CONSTANT_POOL_BEFORE_FUNCTION)
1662 output_constant_pool (fnname, decl);
1664 resolve_unique_section (decl, 0, flag_function_sections);
1666 /* Make sure the not and cold text (code) sections are properly
1667 aligned. This is necessary here in the case where the function
1668 has both hot and cold sections, because we don't want to re-set
1669 the alignment when the section switch happens mid-function. */
1671 if (flag_reorder_blocks_and_partition)
1673 switch_to_section (unlikely_text_section ());
1674 assemble_align (DECL_ALIGN (decl));
1675 ASM_OUTPUT_LABEL (asm_out_file, crtl->subsections.cold_section_label);
1677 /* When the function starts with a cold section, we need to explicitly
1678 align the hot section and write out the hot section label.
1679 But if the current function is a thunk, we do not have a CFG. */
1680 if (!crtl->is_thunk
1681 && BB_PARTITION (ENTRY_BLOCK_PTR->next_bb) == BB_COLD_PARTITION)
1683 switch_to_section (text_section);
1684 assemble_align (DECL_ALIGN (decl));
1685 ASM_OUTPUT_LABEL (asm_out_file, crtl->subsections.hot_section_label);
1686 hot_label_written = true;
1687 first_function_block_is_cold = true;
1690 else if (DECL_SECTION_NAME (decl))
1692 /* Calls to function_section rely on first_function_block_is_cold
1693 being accurate. The first block may be cold even if we aren't
1694 doing partitioning, if the entire function was decided by
1695 choose_function_section (predict.c) to be cold. */
1697 initialize_cold_section_name ();
1699 if (crtl->subsections.unlikely_text_section_name
1700 && strcmp (TREE_STRING_POINTER (DECL_SECTION_NAME (decl)),
1701 crtl->subsections.unlikely_text_section_name) == 0)
1702 first_function_block_is_cold = true;
1705 in_cold_section_p = first_function_block_is_cold;
1707 /* Switch to the correct text section for the start of the function. */
1709 switch_to_section (function_section (decl));
1710 if (flag_reorder_blocks_and_partition
1711 && !hot_label_written)
1712 ASM_OUTPUT_LABEL (asm_out_file, crtl->subsections.hot_section_label);
1714 /* Tell assembler to move to target machine's alignment for functions. */
1715 align = floor_log2 (DECL_ALIGN (decl) / BITS_PER_UNIT);
1716 if (align > 0)
1718 ASM_OUTPUT_ALIGN (asm_out_file, align);
1721 /* Handle a user-specified function alignment.
1722 Note that we still need to align to DECL_ALIGN, as above,
1723 because ASM_OUTPUT_MAX_SKIP_ALIGN might not do any alignment at all. */
1724 if (! DECL_USER_ALIGN (decl)
1725 && align_functions_log > align
1726 && optimize_function_for_speed_p (cfun))
1728 #ifdef ASM_OUTPUT_MAX_SKIP_ALIGN
1729 ASM_OUTPUT_MAX_SKIP_ALIGN (asm_out_file,
1730 align_functions_log, align_functions - 1);
1731 #else
1732 ASM_OUTPUT_ALIGN (asm_out_file, align_functions_log);
1733 #endif
1736 #ifdef ASM_OUTPUT_FUNCTION_PREFIX
1737 ASM_OUTPUT_FUNCTION_PREFIX (asm_out_file, fnname);
1738 #endif
1740 (*debug_hooks->begin_function) (decl);
1742 /* Make function name accessible from other files, if appropriate. */
1744 if (TREE_PUBLIC (decl))
1746 notice_global_symbol (decl);
1748 globalize_decl (decl);
1750 maybe_assemble_visibility (decl);
1753 if (DECL_PRESERVE_P (decl))
1754 targetm.asm_out.mark_decl_preserved (fnname);
1756 /* Do any machine/system dependent processing of the function name. */
1757 #ifdef ASM_DECLARE_FUNCTION_NAME
1758 ASM_DECLARE_FUNCTION_NAME (asm_out_file, fnname, current_function_decl);
1759 #else
1760 /* Standard thing is just output label for the function. */
1761 ASM_OUTPUT_LABEL (asm_out_file, fnname);
1762 #endif /* ASM_DECLARE_FUNCTION_NAME */
1765 /* Output assembler code associated with defining the size of the
1766 function. DECL describes the function. NAME is the function's name. */
1768 void
1769 assemble_end_function (tree decl, const char *fnname ATTRIBUTE_UNUSED)
1771 #ifdef ASM_DECLARE_FUNCTION_SIZE
1772 /* We could have switched section in the middle of the function. */
1773 if (flag_reorder_blocks_and_partition)
1774 switch_to_section (function_section (decl));
1775 ASM_DECLARE_FUNCTION_SIZE (asm_out_file, fnname, decl);
1776 #endif
1777 if (! CONSTANT_POOL_BEFORE_FUNCTION)
1779 output_constant_pool (fnname, decl);
1780 switch_to_section (function_section (decl)); /* need to switch back */
1782 /* Output labels for end of hot/cold text sections (to be used by
1783 debug info.) */
1784 if (flag_reorder_blocks_and_partition)
1786 section *save_text_section;
1788 save_text_section = in_section;
1789 switch_to_section (unlikely_text_section ());
1790 ASM_OUTPUT_LABEL (asm_out_file, crtl->subsections.cold_section_end_label);
1791 if (first_function_block_is_cold)
1792 switch_to_section (text_section);
1793 else
1794 switch_to_section (function_section (decl));
1795 ASM_OUTPUT_LABEL (asm_out_file, crtl->subsections.hot_section_end_label);
1796 switch_to_section (save_text_section);
1800 /* Assemble code to leave SIZE bytes of zeros. */
1802 void
1803 assemble_zeros (unsigned HOST_WIDE_INT size)
1805 /* Do no output if -fsyntax-only. */
1806 if (flag_syntax_only)
1807 return;
1809 #ifdef ASM_NO_SKIP_IN_TEXT
1810 /* The `space' pseudo in the text section outputs nop insns rather than 0s,
1811 so we must output 0s explicitly in the text section. */
1812 if (ASM_NO_SKIP_IN_TEXT && (in_section->common.flags & SECTION_CODE) != 0)
1814 unsigned HOST_WIDE_INT i;
1815 for (i = 0; i < size; i++)
1816 assemble_integer (const0_rtx, 1, BITS_PER_UNIT, 1);
1818 else
1819 #endif
1820 if (size > 0)
1821 ASM_OUTPUT_SKIP (asm_out_file, size);
1824 /* Assemble an alignment pseudo op for an ALIGN-bit boundary. */
1826 void
1827 assemble_align (int align)
1829 if (align > BITS_PER_UNIT)
1831 ASM_OUTPUT_ALIGN (asm_out_file, floor_log2 (align / BITS_PER_UNIT));
1835 /* Assemble a string constant with the specified C string as contents. */
1837 void
1838 assemble_string (const char *p, int size)
1840 int pos = 0;
1841 int maximum = 2000;
1843 /* If the string is very long, split it up. */
1845 while (pos < size)
1847 int thissize = size - pos;
1848 if (thissize > maximum)
1849 thissize = maximum;
1851 ASM_OUTPUT_ASCII (asm_out_file, p, thissize);
1853 pos += thissize;
1854 p += thissize;
1859 /* A noswitch_section_callback for lcomm_section. */
1861 static bool
1862 emit_local (tree decl ATTRIBUTE_UNUSED,
1863 const char *name ATTRIBUTE_UNUSED,
1864 unsigned HOST_WIDE_INT size ATTRIBUTE_UNUSED,
1865 unsigned HOST_WIDE_INT rounded ATTRIBUTE_UNUSED)
1867 #if defined ASM_OUTPUT_ALIGNED_DECL_LOCAL
1868 ASM_OUTPUT_ALIGNED_DECL_LOCAL (asm_out_file, decl, name,
1869 size, DECL_ALIGN (decl));
1870 return true;
1871 #elif defined ASM_OUTPUT_ALIGNED_LOCAL
1872 ASM_OUTPUT_ALIGNED_LOCAL (asm_out_file, name, size, DECL_ALIGN (decl));
1873 return true;
1874 #else
1875 ASM_OUTPUT_LOCAL (asm_out_file, name, size, rounded);
1876 return false;
1877 #endif
1880 /* A noswitch_section_callback for bss_noswitch_section. */
1882 #if defined ASM_OUTPUT_ALIGNED_BSS || defined ASM_OUTPUT_BSS
1883 static bool
1884 emit_bss (tree decl ATTRIBUTE_UNUSED,
1885 const char *name ATTRIBUTE_UNUSED,
1886 unsigned HOST_WIDE_INT size ATTRIBUTE_UNUSED,
1887 unsigned HOST_WIDE_INT rounded ATTRIBUTE_UNUSED)
1889 #if defined ASM_OUTPUT_ALIGNED_BSS
1890 ASM_OUTPUT_ALIGNED_BSS (asm_out_file, decl, name, size, DECL_ALIGN (decl));
1891 return true;
1892 #else
1893 ASM_OUTPUT_BSS (asm_out_file, decl, name, size, rounded);
1894 return false;
1895 #endif
1897 #endif
1899 /* A noswitch_section_callback for comm_section. */
1901 static bool
1902 emit_common (tree decl ATTRIBUTE_UNUSED,
1903 const char *name ATTRIBUTE_UNUSED,
1904 unsigned HOST_WIDE_INT size ATTRIBUTE_UNUSED,
1905 unsigned HOST_WIDE_INT rounded ATTRIBUTE_UNUSED)
1907 #if defined ASM_OUTPUT_ALIGNED_DECL_COMMON
1908 ASM_OUTPUT_ALIGNED_DECL_COMMON (asm_out_file, decl, name,
1909 size, DECL_ALIGN (decl));
1910 return true;
1911 #elif defined ASM_OUTPUT_ALIGNED_COMMON
1912 ASM_OUTPUT_ALIGNED_COMMON (asm_out_file, name, size, DECL_ALIGN (decl));
1913 return true;
1914 #else
1915 ASM_OUTPUT_COMMON (asm_out_file, name, size, rounded);
1916 return false;
1917 #endif
1920 /* A noswitch_section_callback for tls_comm_section. */
1922 static bool
1923 emit_tls_common (tree decl ATTRIBUTE_UNUSED,
1924 const char *name ATTRIBUTE_UNUSED,
1925 unsigned HOST_WIDE_INT size ATTRIBUTE_UNUSED,
1926 unsigned HOST_WIDE_INT rounded ATTRIBUTE_UNUSED)
1928 #ifdef ASM_OUTPUT_TLS_COMMON
1929 ASM_OUTPUT_TLS_COMMON (asm_out_file, decl, name, size);
1930 return true;
1931 #else
1932 sorry ("thread-local COMMON data not implemented");
1933 return true;
1934 #endif
1937 /* Assemble DECL given that it belongs in SECTION_NOSWITCH section SECT.
1938 NAME is the name of DECL's SYMBOL_REF. */
1940 static void
1941 assemble_noswitch_variable (tree decl, const char *name, section *sect)
1943 unsigned HOST_WIDE_INT size, rounded;
1945 size = tree_low_cst (DECL_SIZE_UNIT (decl), 1);
1946 rounded = size;
1948 /* Don't allocate zero bytes of common,
1949 since that means "undefined external" in the linker. */
1950 if (size == 0)
1951 rounded = 1;
1953 /* Round size up to multiple of BIGGEST_ALIGNMENT bits
1954 so that each uninitialized object starts on such a boundary. */
1955 rounded += (BIGGEST_ALIGNMENT / BITS_PER_UNIT) - 1;
1956 rounded = (rounded / (BIGGEST_ALIGNMENT / BITS_PER_UNIT)
1957 * (BIGGEST_ALIGNMENT / BITS_PER_UNIT));
1959 if (!sect->noswitch.callback (decl, name, size, rounded)
1960 && (unsigned HOST_WIDE_INT) DECL_ALIGN_UNIT (decl) > rounded)
1961 warning (0, "requested alignment for %q+D is greater than "
1962 "implemented alignment of %wu", decl, rounded);
1965 /* A subroutine of assemble_variable. Output the label and contents of
1966 DECL, whose address is a SYMBOL_REF with name NAME. DONT_OUTPUT_DATA
1967 is as for assemble_variable. */
1969 static void
1970 assemble_variable_contents (tree decl, const char *name,
1971 bool dont_output_data)
1973 /* Do any machine/system dependent processing of the object. */
1974 #ifdef ASM_DECLARE_OBJECT_NAME
1975 last_assemble_variable_decl = decl;
1976 ASM_DECLARE_OBJECT_NAME (asm_out_file, name, decl);
1977 #else
1978 /* Standard thing is just output label for the object. */
1979 ASM_OUTPUT_LABEL (asm_out_file, name);
1980 #endif /* ASM_DECLARE_OBJECT_NAME */
1982 if (!dont_output_data)
1984 if (DECL_INITIAL (decl)
1985 && DECL_INITIAL (decl) != error_mark_node
1986 && !initializer_zerop (DECL_INITIAL (decl)))
1987 /* Output the actual data. */
1988 output_constant (DECL_INITIAL (decl),
1989 tree_low_cst (DECL_SIZE_UNIT (decl), 1),
1990 DECL_ALIGN (decl));
1991 else
1992 /* Leave space for it. */
1993 assemble_zeros (tree_low_cst (DECL_SIZE_UNIT (decl), 1));
1997 /* Initialize emulated tls object TO, which refers to TLS variable
1998 DECL and is initialized by PROXY. */
2000 tree
2001 default_emutls_var_init (tree to, tree decl, tree proxy)
2003 VEC(constructor_elt,gc) *v = VEC_alloc (constructor_elt, gc, 4);
2004 constructor_elt *elt;
2005 tree type = TREE_TYPE (to);
2006 tree field = TYPE_FIELDS (type);
2008 elt = VEC_quick_push (constructor_elt, v, NULL);
2009 elt->index = field;
2010 elt->value = fold_convert (TREE_TYPE (field), DECL_SIZE_UNIT (decl));
2012 elt = VEC_quick_push (constructor_elt, v, NULL);
2013 field = TREE_CHAIN (field);
2014 elt->index = field;
2015 elt->value = build_int_cst (TREE_TYPE (field),
2016 DECL_ALIGN_UNIT (decl));
2018 elt = VEC_quick_push (constructor_elt, v, NULL);
2019 field = TREE_CHAIN (field);
2020 elt->index = field;
2021 elt->value = null_pointer_node;
2023 elt = VEC_quick_push (constructor_elt, v, NULL);
2024 field = TREE_CHAIN (field);
2025 elt->index = field;
2026 elt->value = proxy;
2028 return build_constructor (type, v);
2031 /* Assemble everything that is needed for a variable or function declaration.
2032 Not used for automatic variables, and not used for function definitions.
2033 Should not be called for variables of incomplete structure type.
2035 TOP_LEVEL is nonzero if this variable has file scope.
2036 AT_END is nonzero if this is the special handling, at end of compilation,
2037 to define things that have had only tentative definitions.
2038 DONT_OUTPUT_DATA if nonzero means don't actually output the
2039 initial value (that will be done by the caller). */
2041 void
2042 assemble_variable (tree decl, int top_level ATTRIBUTE_UNUSED,
2043 int at_end ATTRIBUTE_UNUSED, int dont_output_data)
2045 const char *name;
2046 rtx decl_rtl, symbol;
2047 section *sect;
2049 if (! targetm.have_tls
2050 && TREE_CODE (decl) == VAR_DECL
2051 && DECL_THREAD_LOCAL_P (decl))
2053 tree to = emutls_decl (decl);
2055 /* If this variable is defined locally, then we need to initialize the
2056 control structure with size and alignment information. We do this
2057 at the last moment because tentative definitions can take a locally
2058 defined but uninitialized variable and initialize it later, which
2059 would result in incorrect contents. */
2060 if (! DECL_EXTERNAL (to)
2061 && (! DECL_COMMON (to)
2062 || (DECL_INITIAL (decl)
2063 && DECL_INITIAL (decl) != error_mark_node)))
2065 DECL_INITIAL (to) = targetm.emutls.var_init
2066 (to, decl, get_emutls_init_templ_addr (decl));
2068 /* Make sure the template is marked as needed early enough.
2069 Without this, if the variable is placed in a
2070 section-anchored block, the template will only be marked
2071 when it's too late. */
2072 record_references_in_initializer (to);
2075 decl = to;
2078 last_assemble_variable_decl = 0;
2080 /* Normally no need to say anything here for external references,
2081 since assemble_external is called by the language-specific code
2082 when a declaration is first seen. */
2084 if (DECL_EXTERNAL (decl))
2085 return;
2087 /* Output no assembler code for a function declaration.
2088 Only definitions of functions output anything. */
2090 if (TREE_CODE (decl) == FUNCTION_DECL)
2091 return;
2093 /* Do nothing for global register variables. */
2094 if (DECL_RTL_SET_P (decl) && REG_P (DECL_RTL (decl)))
2096 TREE_ASM_WRITTEN (decl) = 1;
2097 return;
2100 /* If type was incomplete when the variable was declared,
2101 see if it is complete now. */
2103 if (DECL_SIZE (decl) == 0)
2104 layout_decl (decl, 0);
2106 /* Still incomplete => don't allocate it; treat the tentative defn
2107 (which is what it must have been) as an `extern' reference. */
2109 if (!dont_output_data && DECL_SIZE (decl) == 0)
2111 error ("storage size of %q+D isn%'t known", decl);
2112 TREE_ASM_WRITTEN (decl) = 1;
2113 return;
2116 /* The first declaration of a variable that comes through this function
2117 decides whether it is global (in C, has external linkage)
2118 or local (in C, has internal linkage). So do nothing more
2119 if this function has already run. */
2121 if (TREE_ASM_WRITTEN (decl))
2122 return;
2124 /* Make sure targetm.encode_section_info is invoked before we set
2125 ASM_WRITTEN. */
2126 decl_rtl = DECL_RTL (decl);
2128 TREE_ASM_WRITTEN (decl) = 1;
2130 /* Do no output if -fsyntax-only. */
2131 if (flag_syntax_only)
2132 return;
2134 app_disable ();
2136 if (! dont_output_data
2137 && ! host_integerp (DECL_SIZE_UNIT (decl), 1))
2139 error ("size of variable %q+D is too large", decl);
2140 return;
2143 gcc_assert (MEM_P (decl_rtl));
2144 gcc_assert (GET_CODE (XEXP (decl_rtl, 0)) == SYMBOL_REF);
2145 symbol = XEXP (decl_rtl, 0);
2146 name = XSTR (symbol, 0);
2147 if (TREE_PUBLIC (decl) && DECL_NAME (decl))
2148 notice_global_symbol (decl);
2150 /* Compute the alignment of this data. */
2152 align_variable (decl, dont_output_data);
2153 set_mem_align (decl_rtl, DECL_ALIGN (decl));
2155 if (TREE_PUBLIC (decl))
2156 maybe_assemble_visibility (decl);
2158 if (DECL_PRESERVE_P (decl))
2159 targetm.asm_out.mark_decl_preserved (name);
2161 /* First make the assembler name(s) global if appropriate. */
2162 sect = get_variable_section (decl, false);
2163 if (TREE_PUBLIC (decl)
2164 && DECL_NAME (decl)
2165 && (sect->common.flags & SECTION_COMMON) == 0)
2166 globalize_decl (decl);
2168 /* Output any data that we will need to use the address of. */
2169 if (DECL_INITIAL (decl) && DECL_INITIAL (decl) != error_mark_node)
2170 output_addressed_constants (DECL_INITIAL (decl));
2172 /* dbxout.c needs to know this. */
2173 if (sect && (sect->common.flags & SECTION_CODE) != 0)
2174 DECL_IN_TEXT_SECTION (decl) = 1;
2176 /* If the decl is part of an object_block, make sure that the decl
2177 has been positioned within its block, but do not write out its
2178 definition yet. output_object_blocks will do that later. */
2179 if (SYMBOL_REF_HAS_BLOCK_INFO_P (symbol) && SYMBOL_REF_BLOCK (symbol))
2181 gcc_assert (!dont_output_data);
2182 place_block_symbol (symbol);
2184 else if (SECTION_STYLE (sect) == SECTION_NOSWITCH)
2185 assemble_noswitch_variable (decl, name, sect);
2186 else
2188 switch_to_section (sect);
2189 if (DECL_ALIGN (decl) > BITS_PER_UNIT)
2190 ASM_OUTPUT_ALIGN (asm_out_file, floor_log2 (DECL_ALIGN_UNIT (decl)));
2191 assemble_variable_contents (decl, name, dont_output_data);
2195 /* Return 1 if type TYPE contains any pointers. */
2197 static int
2198 contains_pointers_p (tree type)
2200 switch (TREE_CODE (type))
2202 case POINTER_TYPE:
2203 case REFERENCE_TYPE:
2204 /* I'm not sure whether OFFSET_TYPE needs this treatment,
2205 so I'll play safe and return 1. */
2206 case OFFSET_TYPE:
2207 return 1;
2209 case RECORD_TYPE:
2210 case UNION_TYPE:
2211 case QUAL_UNION_TYPE:
2213 tree fields;
2214 /* For a type that has fields, see if the fields have pointers. */
2215 for (fields = TYPE_FIELDS (type); fields; fields = TREE_CHAIN (fields))
2216 if (TREE_CODE (fields) == FIELD_DECL
2217 && contains_pointers_p (TREE_TYPE (fields)))
2218 return 1;
2219 return 0;
2222 case ARRAY_TYPE:
2223 /* An array type contains pointers if its element type does. */
2224 return contains_pointers_p (TREE_TYPE (type));
2226 default:
2227 return 0;
2231 /* We delay assemble_external processing until
2232 the compilation unit is finalized. This is the best we can do for
2233 right now (i.e. stage 3 of GCC 4.0) - the right thing is to delay
2234 it all the way to final. See PR 17982 for further discussion. */
2235 static GTY(()) tree pending_assemble_externals;
2237 #ifdef ASM_OUTPUT_EXTERNAL
2238 /* True if DECL is a function decl for which no out-of-line copy exists.
2239 It is assumed that DECL's assembler name has been set. */
2241 static bool
2242 incorporeal_function_p (tree decl)
2244 if (TREE_CODE (decl) == FUNCTION_DECL && DECL_BUILT_IN (decl))
2246 const char *name;
2248 if (DECL_BUILT_IN_CLASS (decl) == BUILT_IN_NORMAL
2249 && DECL_FUNCTION_CODE (decl) == BUILT_IN_ALLOCA)
2250 return true;
2252 name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
2253 if (strncmp (name, "__builtin_", strlen ("__builtin_")) == 0)
2254 return true;
2256 return false;
2259 /* Actually do the tests to determine if this is necessary, and invoke
2260 ASM_OUTPUT_EXTERNAL. */
2261 static void
2262 assemble_external_real (tree decl)
2264 rtx rtl = DECL_RTL (decl);
2266 if (MEM_P (rtl) && GET_CODE (XEXP (rtl, 0)) == SYMBOL_REF
2267 && !SYMBOL_REF_USED (XEXP (rtl, 0))
2268 && !incorporeal_function_p (decl))
2270 /* Some systems do require some output. */
2271 SYMBOL_REF_USED (XEXP (rtl, 0)) = 1;
2272 ASM_OUTPUT_EXTERNAL (asm_out_file, decl, XSTR (XEXP (rtl, 0), 0));
2275 #endif
2277 void
2278 process_pending_assemble_externals (void)
2280 #ifdef ASM_OUTPUT_EXTERNAL
2281 tree list;
2282 for (list = pending_assemble_externals; list; list = TREE_CHAIN (list))
2283 assemble_external_real (TREE_VALUE (list));
2285 pending_assemble_externals = 0;
2286 #endif
2289 /* This TREE_LIST contains any weak symbol declarations waiting
2290 to be emitted. */
2291 static GTY(()) tree weak_decls;
2293 /* Output something to declare an external symbol to the assembler,
2294 and qualifiers such as weakness. (Most assemblers don't need
2295 extern declaration, so we normally output nothing.) Do nothing if
2296 DECL is not external. */
2298 void
2299 assemble_external (tree decl ATTRIBUTE_UNUSED)
2301 /* Because most platforms do not define ASM_OUTPUT_EXTERNAL, the
2302 main body of this code is only rarely exercised. To provide some
2303 testing, on all platforms, we make sure that the ASM_OUT_FILE is
2304 open. If it's not, we should not be calling this function. */
2305 gcc_assert (asm_out_file);
2307 if (!DECL_P (decl) || !DECL_EXTERNAL (decl) || !TREE_PUBLIC (decl))
2308 return;
2310 /* We want to output annotation for weak and external symbols at
2311 very last to check if they are references or not. */
2313 if (SUPPORTS_WEAK && DECL_WEAK (decl)
2314 /* TREE_STATIC is a weird and abused creature which is not
2315 generally the right test for whether an entity has been
2316 locally emitted, inlined or otherwise not-really-extern, but
2317 for declarations that can be weak, it happens to be
2318 match. */
2319 && !TREE_STATIC (decl))
2320 weak_decls = tree_cons (NULL, decl, weak_decls);
2322 #ifdef ASM_OUTPUT_EXTERNAL
2323 pending_assemble_externals = tree_cons (0, decl,
2324 pending_assemble_externals);
2325 #endif
2328 /* Similar, for calling a library function FUN. */
2330 void
2331 assemble_external_libcall (rtx fun)
2333 /* Declare library function name external when first used, if nec. */
2334 if (! SYMBOL_REF_USED (fun))
2336 SYMBOL_REF_USED (fun) = 1;
2337 targetm.asm_out.external_libcall (fun);
2341 /* Assemble a label named NAME. */
2343 void
2344 assemble_label (const char *name)
2346 ASM_OUTPUT_LABEL (asm_out_file, name);
2349 /* Set the symbol_referenced flag for ID. */
2350 void
2351 mark_referenced (tree id)
2353 TREE_SYMBOL_REFERENCED (id) = 1;
2356 /* Set the symbol_referenced flag for DECL and notify callgraph. */
2357 void
2358 mark_decl_referenced (tree decl)
2360 if (TREE_CODE (decl) == FUNCTION_DECL)
2362 /* Extern inline functions don't become needed when referenced.
2363 If we know a method will be emitted in other TU and no new
2364 functions can be marked reachable, just use the external
2365 definition. */
2366 struct cgraph_node *node = cgraph_node (decl);
2367 if (!DECL_EXTERNAL (decl)
2368 && (!node->local.vtable_method || !cgraph_global_info_ready
2369 || !node->local.finalized))
2370 cgraph_mark_needed_node (node);
2372 else if (TREE_CODE (decl) == VAR_DECL)
2374 struct varpool_node *node = varpool_node (decl);
2375 varpool_mark_needed_node (node);
2376 /* C++ frontend use mark_decl_references to force COMDAT variables
2377 to be output that might appear dead otherwise. */
2378 node->force_output = true;
2380 /* else do nothing - we can get various sorts of CST nodes here,
2381 which do not need to be marked. */
2385 /* Follow the IDENTIFIER_TRANSPARENT_ALIAS chain starting at *ALIAS
2386 until we find an identifier that is not itself a transparent alias.
2387 Modify the alias passed to it by reference (and all aliases on the
2388 way to the ultimate target), such that they do not have to be
2389 followed again, and return the ultimate target of the alias
2390 chain. */
2392 static inline tree
2393 ultimate_transparent_alias_target (tree *alias)
2395 tree target = *alias;
2397 if (IDENTIFIER_TRANSPARENT_ALIAS (target))
2399 gcc_assert (TREE_CHAIN (target));
2400 target = ultimate_transparent_alias_target (&TREE_CHAIN (target));
2401 gcc_assert (! IDENTIFIER_TRANSPARENT_ALIAS (target)
2402 && ! TREE_CHAIN (target));
2403 *alias = target;
2406 return target;
2409 /* Output to FILE (an assembly file) a reference to NAME. If NAME
2410 starts with a *, the rest of NAME is output verbatim. Otherwise
2411 NAME is transformed in a target-specific way (usually by the
2412 addition of an underscore). */
2414 void
2415 assemble_name_raw (FILE *file, const char *name)
2417 if (name[0] == '*')
2418 fputs (&name[1], file);
2419 else
2420 ASM_OUTPUT_LABELREF (file, name);
2423 /* Like assemble_name_raw, but should be used when NAME might refer to
2424 an entity that is also represented as a tree (like a function or
2425 variable). If NAME does refer to such an entity, that entity will
2426 be marked as referenced. */
2428 void
2429 assemble_name (FILE *file, const char *name)
2431 const char *real_name;
2432 tree id;
2434 real_name = targetm.strip_name_encoding (name);
2436 id = maybe_get_identifier (real_name);
2437 if (id)
2439 tree id_orig = id;
2441 mark_referenced (id);
2442 ultimate_transparent_alias_target (&id);
2443 if (id != id_orig)
2444 name = IDENTIFIER_POINTER (id);
2445 gcc_assert (! TREE_CHAIN (id));
2448 assemble_name_raw (file, name);
2451 /* Allocate SIZE bytes writable static space with a gensym name
2452 and return an RTX to refer to its address. */
2455 assemble_static_space (unsigned HOST_WIDE_INT size)
2457 char name[12];
2458 const char *namestring;
2459 rtx x;
2461 ASM_GENERATE_INTERNAL_LABEL (name, "LF", const_labelno);
2462 ++const_labelno;
2463 namestring = ggc_strdup (name);
2465 x = gen_rtx_SYMBOL_REF (Pmode, namestring);
2466 SYMBOL_REF_FLAGS (x) = SYMBOL_FLAG_LOCAL;
2468 #ifdef ASM_OUTPUT_ALIGNED_DECL_LOCAL
2469 ASM_OUTPUT_ALIGNED_DECL_LOCAL (asm_out_file, NULL_TREE, name, size,
2470 BIGGEST_ALIGNMENT);
2471 #else
2472 #ifdef ASM_OUTPUT_ALIGNED_LOCAL
2473 ASM_OUTPUT_ALIGNED_LOCAL (asm_out_file, name, size, BIGGEST_ALIGNMENT);
2474 #else
2476 /* Round size up to multiple of BIGGEST_ALIGNMENT bits
2477 so that each uninitialized object starts on such a boundary. */
2478 /* Variable `rounded' might or might not be used in ASM_OUTPUT_LOCAL. */
2479 unsigned HOST_WIDE_INT rounded ATTRIBUTE_UNUSED
2480 = ((size + (BIGGEST_ALIGNMENT / BITS_PER_UNIT) - 1)
2481 / (BIGGEST_ALIGNMENT / BITS_PER_UNIT)
2482 * (BIGGEST_ALIGNMENT / BITS_PER_UNIT));
2483 ASM_OUTPUT_LOCAL (asm_out_file, name, size, rounded);
2485 #endif
2486 #endif
2487 return x;
2490 /* Assemble the static constant template for function entry trampolines.
2491 This is done at most once per compilation.
2492 Returns an RTX for the address of the template. */
2494 static GTY(()) rtx initial_trampoline;
2496 #ifdef TRAMPOLINE_TEMPLATE
2498 assemble_trampoline_template (void)
2500 char label[256];
2501 const char *name;
2502 int align;
2503 rtx symbol;
2505 if (initial_trampoline)
2506 return initial_trampoline;
2508 /* By default, put trampoline templates in read-only data section. */
2510 #ifdef TRAMPOLINE_SECTION
2511 switch_to_section (TRAMPOLINE_SECTION);
2512 #else
2513 switch_to_section (readonly_data_section);
2514 #endif
2516 /* Write the assembler code to define one. */
2517 align = floor_log2 (TRAMPOLINE_ALIGNMENT / BITS_PER_UNIT);
2518 if (align > 0)
2520 ASM_OUTPUT_ALIGN (asm_out_file, align);
2523 targetm.asm_out.internal_label (asm_out_file, "LTRAMP", 0);
2524 TRAMPOLINE_TEMPLATE (asm_out_file);
2526 /* Record the rtl to refer to it. */
2527 ASM_GENERATE_INTERNAL_LABEL (label, "LTRAMP", 0);
2528 name = ggc_strdup (label);
2529 symbol = gen_rtx_SYMBOL_REF (Pmode, name);
2530 SYMBOL_REF_FLAGS (symbol) = SYMBOL_FLAG_LOCAL;
2532 initial_trampoline = gen_rtx_MEM (BLKmode, symbol);
2533 set_mem_align (initial_trampoline, TRAMPOLINE_ALIGNMENT);
2535 return initial_trampoline;
2537 #endif
2539 /* A and B are either alignments or offsets. Return the minimum alignment
2540 that may be assumed after adding the two together. */
2542 static inline unsigned
2543 min_align (unsigned int a, unsigned int b)
2545 return (a | b) & -(a | b);
2548 /* Return the assembler directive for creating a given kind of integer
2549 object. SIZE is the number of bytes in the object and ALIGNED_P
2550 indicates whether it is known to be aligned. Return NULL if the
2551 assembly dialect has no such directive.
2553 The returned string should be printed at the start of a new line and
2554 be followed immediately by the object's initial value. */
2556 const char *
2557 integer_asm_op (int size, int aligned_p)
2559 struct asm_int_op *ops;
2561 if (aligned_p)
2562 ops = &targetm.asm_out.aligned_op;
2563 else
2564 ops = &targetm.asm_out.unaligned_op;
2566 switch (size)
2568 case 1:
2569 return targetm.asm_out.byte_op;
2570 case 2:
2571 return ops->hi;
2572 case 4:
2573 return ops->si;
2574 case 8:
2575 return ops->di;
2576 case 16:
2577 return ops->ti;
2578 default:
2579 return NULL;
2583 /* Use directive OP to assemble an integer object X. Print OP at the
2584 start of the line, followed immediately by the value of X. */
2586 void
2587 assemble_integer_with_op (const char *op, rtx x)
2589 fputs (op, asm_out_file);
2590 output_addr_const (asm_out_file, x);
2591 fputc ('\n', asm_out_file);
2594 /* The default implementation of the asm_out.integer target hook. */
2596 bool
2597 default_assemble_integer (rtx x ATTRIBUTE_UNUSED,
2598 unsigned int size ATTRIBUTE_UNUSED,
2599 int aligned_p ATTRIBUTE_UNUSED)
2601 const char *op = integer_asm_op (size, aligned_p);
2602 /* Avoid GAS bugs for large values. Specifically negative values whose
2603 absolute value fits in a bfd_vma, but not in a bfd_signed_vma. */
2604 if (size > UNITS_PER_WORD && size > POINTER_SIZE / BITS_PER_UNIT)
2605 return false;
2606 return op && (assemble_integer_with_op (op, x), true);
2609 /* Assemble the integer constant X into an object of SIZE bytes. ALIGN is
2610 the alignment of the integer in bits. Return 1 if we were able to output
2611 the constant, otherwise 0. We must be able to output the constant,
2612 if FORCE is nonzero. */
2614 bool
2615 assemble_integer (rtx x, unsigned int size, unsigned int align, int force)
2617 int aligned_p;
2619 aligned_p = (align >= MIN (size * BITS_PER_UNIT, BIGGEST_ALIGNMENT));
2621 /* See if the target hook can handle this kind of object. */
2622 if (targetm.asm_out.integer (x, size, aligned_p))
2623 return true;
2625 /* If the object is a multi-byte one, try splitting it up. Split
2626 it into words it if is multi-word, otherwise split it into bytes. */
2627 if (size > 1)
2629 enum machine_mode omode, imode;
2630 unsigned int subalign;
2631 unsigned int subsize, i;
2632 unsigned char mclass;
2634 subsize = size > UNITS_PER_WORD? UNITS_PER_WORD : 1;
2635 subalign = MIN (align, subsize * BITS_PER_UNIT);
2636 if (GET_CODE (x) == CONST_FIXED)
2637 mclass = GET_MODE_CLASS (GET_MODE (x));
2638 else
2639 mclass = MODE_INT;
2641 omode = mode_for_size (subsize * BITS_PER_UNIT, mclass, 0);
2642 imode = mode_for_size (size * BITS_PER_UNIT, mclass, 0);
2644 for (i = 0; i < size; i += subsize)
2646 rtx partial = simplify_subreg (omode, x, imode, i);
2647 if (!partial || !assemble_integer (partial, subsize, subalign, 0))
2648 break;
2650 if (i == size)
2651 return true;
2653 /* If we've printed some of it, but not all of it, there's no going
2654 back now. */
2655 gcc_assert (!i);
2658 gcc_assert (!force);
2660 return false;
2663 void
2664 assemble_real (REAL_VALUE_TYPE d, enum machine_mode mode, unsigned int align)
2666 long data[4] = {0, 0, 0, 0};
2667 int i;
2668 int bitsize, nelts, nunits, units_per;
2670 /* This is hairy. We have a quantity of known size. real_to_target
2671 will put it into an array of *host* longs, 32 bits per element
2672 (even if long is more than 32 bits). We need to determine the
2673 number of array elements that are occupied (nelts) and the number
2674 of *target* min-addressable units that will be occupied in the
2675 object file (nunits). We cannot assume that 32 divides the
2676 mode's bitsize (size * BITS_PER_UNIT) evenly.
2678 size * BITS_PER_UNIT is used here to make sure that padding bits
2679 (which might appear at either end of the value; real_to_target
2680 will include the padding bits in its output array) are included. */
2682 nunits = GET_MODE_SIZE (mode);
2683 bitsize = nunits * BITS_PER_UNIT;
2684 nelts = CEIL (bitsize, 32);
2685 units_per = 32 / BITS_PER_UNIT;
2687 real_to_target (data, &d, mode);
2689 /* Put out the first word with the specified alignment. */
2690 assemble_integer (GEN_INT (data[0]), MIN (nunits, units_per), align, 1);
2691 nunits -= units_per;
2693 /* Subsequent words need only 32-bit alignment. */
2694 align = min_align (align, 32);
2696 for (i = 1; i < nelts; i++)
2698 assemble_integer (GEN_INT (data[i]), MIN (nunits, units_per), align, 1);
2699 nunits -= units_per;
2703 /* Given an expression EXP with a constant value,
2704 reduce it to the sum of an assembler symbol and an integer.
2705 Store them both in the structure *VALUE.
2706 EXP must be reducible. */
2708 struct addr_const GTY(())
2710 rtx base;
2711 HOST_WIDE_INT offset;
2714 static void
2715 decode_addr_const (tree exp, struct addr_const *value)
2717 tree target = TREE_OPERAND (exp, 0);
2718 int offset = 0;
2719 rtx x;
2721 while (1)
2723 if (TREE_CODE (target) == COMPONENT_REF
2724 && host_integerp (byte_position (TREE_OPERAND (target, 1)), 0))
2727 offset += int_byte_position (TREE_OPERAND (target, 1));
2728 target = TREE_OPERAND (target, 0);
2730 else if (TREE_CODE (target) == ARRAY_REF
2731 || TREE_CODE (target) == ARRAY_RANGE_REF)
2733 offset += (tree_low_cst (TYPE_SIZE_UNIT (TREE_TYPE (target)), 1)
2734 * tree_low_cst (TREE_OPERAND (target, 1), 0));
2735 target = TREE_OPERAND (target, 0);
2737 else
2738 break;
2741 switch (TREE_CODE (target))
2743 case VAR_DECL:
2744 case FUNCTION_DECL:
2745 x = DECL_RTL (target);
2746 break;
2748 case LABEL_DECL:
2749 x = gen_rtx_MEM (FUNCTION_MODE,
2750 gen_rtx_LABEL_REF (Pmode, force_label_rtx (target)));
2751 break;
2753 case REAL_CST:
2754 case FIXED_CST:
2755 case STRING_CST:
2756 case COMPLEX_CST:
2757 case CONSTRUCTOR:
2758 case INTEGER_CST:
2759 x = output_constant_def (target, 1);
2760 break;
2762 default:
2763 gcc_unreachable ();
2766 gcc_assert (MEM_P (x));
2767 x = XEXP (x, 0);
2769 value->base = x;
2770 value->offset = offset;
2773 /* Uniquize all constants that appear in memory.
2774 Each constant in memory thus far output is recorded
2775 in `const_desc_table'. */
2777 struct constant_descriptor_tree GTY(())
2779 /* A MEM for the constant. */
2780 rtx rtl;
2782 /* The value of the constant. */
2783 tree value;
2785 /* Hash of value. Computing the hash from value each time
2786 hashfn is called can't work properly, as that means recursive
2787 use of the hash table during hash table expansion. */
2788 hashval_t hash;
2791 static GTY((param_is (struct constant_descriptor_tree)))
2792 htab_t const_desc_htab;
2794 static struct constant_descriptor_tree * build_constant_desc (tree);
2795 static void maybe_output_constant_def_contents (struct constant_descriptor_tree *, int);
2797 /* Compute a hash code for a constant expression. */
2799 static hashval_t
2800 const_desc_hash (const void *ptr)
2802 return ((const struct constant_descriptor_tree *)ptr)->hash;
2805 static hashval_t
2806 const_hash_1 (const tree exp)
2808 const char *p;
2809 hashval_t hi;
2810 int len, i;
2811 enum tree_code code = TREE_CODE (exp);
2813 /* Either set P and LEN to the address and len of something to hash and
2814 exit the switch or return a value. */
2816 switch (code)
2818 case INTEGER_CST:
2819 p = (char *) &TREE_INT_CST (exp);
2820 len = sizeof TREE_INT_CST (exp);
2821 break;
2823 case REAL_CST:
2824 return real_hash (TREE_REAL_CST_PTR (exp));
2826 case FIXED_CST:
2827 return fixed_hash (TREE_FIXED_CST_PTR (exp));
2829 case STRING_CST:
2830 p = TREE_STRING_POINTER (exp);
2831 len = TREE_STRING_LENGTH (exp);
2832 break;
2834 case COMPLEX_CST:
2835 return (const_hash_1 (TREE_REALPART (exp)) * 5
2836 + const_hash_1 (TREE_IMAGPART (exp)));
2838 case CONSTRUCTOR:
2840 unsigned HOST_WIDE_INT idx;
2841 tree value;
2843 hi = 5 + int_size_in_bytes (TREE_TYPE (exp));
2845 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (exp), idx, value)
2846 if (value)
2847 hi = hi * 603 + const_hash_1 (value);
2849 return hi;
2852 case ADDR_EXPR:
2853 case FDESC_EXPR:
2855 struct addr_const value;
2857 decode_addr_const (exp, &value);
2858 switch (GET_CODE (value.base))
2860 case SYMBOL_REF:
2861 /* Don't hash the address of the SYMBOL_REF;
2862 only use the offset and the symbol name. */
2863 hi = value.offset;
2864 p = XSTR (value.base, 0);
2865 for (i = 0; p[i] != 0; i++)
2866 hi = ((hi * 613) + (unsigned) (p[i]));
2867 break;
2869 case LABEL_REF:
2870 hi = value.offset + CODE_LABEL_NUMBER (XEXP (value.base, 0)) * 13;
2871 break;
2873 default:
2874 gcc_unreachable ();
2877 return hi;
2879 case PLUS_EXPR:
2880 case POINTER_PLUS_EXPR:
2881 case MINUS_EXPR:
2882 return (const_hash_1 (TREE_OPERAND (exp, 0)) * 9
2883 + const_hash_1 (TREE_OPERAND (exp, 1)));
2885 CASE_CONVERT:
2886 return const_hash_1 (TREE_OPERAND (exp, 0)) * 7 + 2;
2888 default:
2889 /* A language specific constant. Just hash the code. */
2890 return code;
2893 /* Compute hashing function. */
2894 hi = len;
2895 for (i = 0; i < len; i++)
2896 hi = ((hi * 613) + (unsigned) (p[i]));
2898 return hi;
2901 /* Wrapper of compare_constant, for the htab interface. */
2902 static int
2903 const_desc_eq (const void *p1, const void *p2)
2905 const struct constant_descriptor_tree *const c1
2906 = (const struct constant_descriptor_tree *) p1;
2907 const struct constant_descriptor_tree *const c2
2908 = (const struct constant_descriptor_tree *) p2;
2909 if (c1->hash != c2->hash)
2910 return 0;
2911 return compare_constant (c1->value, c2->value);
2914 /* Compare t1 and t2, and return 1 only if they are known to result in
2915 the same bit pattern on output. */
2917 static int
2918 compare_constant (const tree t1, const tree t2)
2920 enum tree_code typecode;
2922 if (t1 == NULL_TREE)
2923 return t2 == NULL_TREE;
2924 if (t2 == NULL_TREE)
2925 return 0;
2927 if (TREE_CODE (t1) != TREE_CODE (t2))
2928 return 0;
2930 switch (TREE_CODE (t1))
2932 case INTEGER_CST:
2933 /* Integer constants are the same only if the same width of type. */
2934 if (TYPE_PRECISION (TREE_TYPE (t1)) != TYPE_PRECISION (TREE_TYPE (t2)))
2935 return 0;
2936 if (TYPE_MODE (TREE_TYPE (t1)) != TYPE_MODE (TREE_TYPE (t2)))
2937 return 0;
2938 return tree_int_cst_equal (t1, t2);
2940 case REAL_CST:
2941 /* Real constants are the same only if the same width of type. */
2942 if (TYPE_PRECISION (TREE_TYPE (t1)) != TYPE_PRECISION (TREE_TYPE (t2)))
2943 return 0;
2945 return REAL_VALUES_IDENTICAL (TREE_REAL_CST (t1), TREE_REAL_CST (t2));
2947 case FIXED_CST:
2948 /* Fixed constants are the same only if the same width of type. */
2949 if (TYPE_PRECISION (TREE_TYPE (t1)) != TYPE_PRECISION (TREE_TYPE (t2)))
2950 return 0;
2952 return FIXED_VALUES_IDENTICAL (TREE_FIXED_CST (t1), TREE_FIXED_CST (t2));
2954 case STRING_CST:
2955 if (TYPE_MODE (TREE_TYPE (t1)) != TYPE_MODE (TREE_TYPE (t2)))
2956 return 0;
2958 return (TREE_STRING_LENGTH (t1) == TREE_STRING_LENGTH (t2)
2959 && ! memcmp (TREE_STRING_POINTER (t1), TREE_STRING_POINTER (t2),
2960 TREE_STRING_LENGTH (t1)));
2962 case COMPLEX_CST:
2963 return (compare_constant (TREE_REALPART (t1), TREE_REALPART (t2))
2964 && compare_constant (TREE_IMAGPART (t1), TREE_IMAGPART (t2)));
2966 case CONSTRUCTOR:
2968 VEC(constructor_elt, gc) *v1, *v2;
2969 unsigned HOST_WIDE_INT idx;
2971 typecode = TREE_CODE (TREE_TYPE (t1));
2972 if (typecode != TREE_CODE (TREE_TYPE (t2)))
2973 return 0;
2975 if (typecode == ARRAY_TYPE)
2977 HOST_WIDE_INT size_1 = int_size_in_bytes (TREE_TYPE (t1));
2978 /* For arrays, check that the sizes all match. */
2979 if (TYPE_MODE (TREE_TYPE (t1)) != TYPE_MODE (TREE_TYPE (t2))
2980 || size_1 == -1
2981 || size_1 != int_size_in_bytes (TREE_TYPE (t2)))
2982 return 0;
2984 else
2986 /* For record and union constructors, require exact type
2987 equality. */
2988 if (TREE_TYPE (t1) != TREE_TYPE (t2))
2989 return 0;
2992 v1 = CONSTRUCTOR_ELTS (t1);
2993 v2 = CONSTRUCTOR_ELTS (t2);
2994 if (VEC_length (constructor_elt, v1)
2995 != VEC_length (constructor_elt, v2))
2996 return 0;
2998 for (idx = 0; idx < VEC_length (constructor_elt, v1); ++idx)
3000 constructor_elt *c1 = VEC_index (constructor_elt, v1, idx);
3001 constructor_elt *c2 = VEC_index (constructor_elt, v2, idx);
3003 /* Check that each value is the same... */
3004 if (!compare_constant (c1->value, c2->value))
3005 return 0;
3006 /* ... and that they apply to the same fields! */
3007 if (typecode == ARRAY_TYPE)
3009 if (!compare_constant (c1->index, c2->index))
3010 return 0;
3012 else
3014 if (c1->index != c2->index)
3015 return 0;
3019 return 1;
3022 case ADDR_EXPR:
3023 case FDESC_EXPR:
3025 struct addr_const value1, value2;
3027 decode_addr_const (t1, &value1);
3028 decode_addr_const (t2, &value2);
3029 return (value1.offset == value2.offset
3030 && strcmp (XSTR (value1.base, 0), XSTR (value2.base, 0)) == 0);
3033 case PLUS_EXPR:
3034 case POINTER_PLUS_EXPR:
3035 case MINUS_EXPR:
3036 case RANGE_EXPR:
3037 return (compare_constant (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0))
3038 && compare_constant(TREE_OPERAND (t1, 1), TREE_OPERAND (t2, 1)));
3040 CASE_CONVERT:
3041 case VIEW_CONVERT_EXPR:
3042 return compare_constant (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
3044 default:
3045 return 0;
3048 gcc_unreachable ();
3051 /* Make a copy of the whole tree structure for a constant. This
3052 handles the same types of nodes that compare_constant handles. */
3054 static tree
3055 copy_constant (tree exp)
3057 switch (TREE_CODE (exp))
3059 case ADDR_EXPR:
3060 /* For ADDR_EXPR, we do not want to copy the decl whose address
3061 is requested. We do want to copy constants though. */
3062 if (CONSTANT_CLASS_P (TREE_OPERAND (exp, 0)))
3063 return build1 (TREE_CODE (exp), TREE_TYPE (exp),
3064 copy_constant (TREE_OPERAND (exp, 0)));
3065 else
3066 return copy_node (exp);
3068 case INTEGER_CST:
3069 case REAL_CST:
3070 case FIXED_CST:
3071 case STRING_CST:
3072 return copy_node (exp);
3074 case COMPLEX_CST:
3075 return build_complex (TREE_TYPE (exp),
3076 copy_constant (TREE_REALPART (exp)),
3077 copy_constant (TREE_IMAGPART (exp)));
3079 case PLUS_EXPR:
3080 case POINTER_PLUS_EXPR:
3081 case MINUS_EXPR:
3082 return build2 (TREE_CODE (exp), TREE_TYPE (exp),
3083 copy_constant (TREE_OPERAND (exp, 0)),
3084 copy_constant (TREE_OPERAND (exp, 1)));
3086 CASE_CONVERT:
3087 case VIEW_CONVERT_EXPR:
3088 return build1 (TREE_CODE (exp), TREE_TYPE (exp),
3089 copy_constant (TREE_OPERAND (exp, 0)));
3091 case CONSTRUCTOR:
3093 tree copy = copy_node (exp);
3094 VEC(constructor_elt, gc) *v;
3095 unsigned HOST_WIDE_INT idx;
3096 tree purpose, value;
3098 v = VEC_alloc(constructor_elt, gc, VEC_length(constructor_elt,
3099 CONSTRUCTOR_ELTS (exp)));
3100 FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (exp), idx, purpose, value)
3102 constructor_elt *ce = VEC_quick_push (constructor_elt, v, NULL);
3103 ce->index = purpose;
3104 ce->value = copy_constant (value);
3106 CONSTRUCTOR_ELTS (copy) = v;
3107 return copy;
3110 default:
3111 gcc_unreachable ();
3115 /* Return the alignment of constant EXP in bits. */
3117 static unsigned int
3118 get_constant_alignment (tree exp)
3120 unsigned int align;
3122 align = TYPE_ALIGN (TREE_TYPE (exp));
3123 #ifdef CONSTANT_ALIGNMENT
3124 align = CONSTANT_ALIGNMENT (exp, align);
3125 #endif
3126 return align;
3129 /* Return the section into which constant EXP should be placed. */
3131 static section *
3132 get_constant_section (tree exp)
3134 if (IN_NAMED_SECTION (exp))
3135 return get_named_section (exp, NULL, compute_reloc_for_constant (exp));
3136 else
3137 return targetm.asm_out.select_section (exp,
3138 compute_reloc_for_constant (exp),
3139 get_constant_alignment (exp));
3142 /* Return the size of constant EXP in bytes. */
3144 static HOST_WIDE_INT
3145 get_constant_size (tree exp)
3147 HOST_WIDE_INT size;
3149 size = int_size_in_bytes (TREE_TYPE (exp));
3150 if (TREE_CODE (exp) == STRING_CST)
3151 size = MAX (TREE_STRING_LENGTH (exp), size);
3152 return size;
3155 /* Subroutine of output_constant_def:
3156 No constant equal to EXP is known to have been output.
3157 Make a constant descriptor to enter EXP in the hash table.
3158 Assign the label number and construct RTL to refer to the
3159 constant's location in memory.
3160 Caller is responsible for updating the hash table. */
3162 static struct constant_descriptor_tree *
3163 build_constant_desc (tree exp)
3165 rtx symbol;
3166 rtx rtl;
3167 char label[256];
3168 int labelno;
3169 struct constant_descriptor_tree *desc;
3171 desc = GGC_NEW (struct constant_descriptor_tree);
3172 desc->value = copy_constant (exp);
3174 /* Propagate marked-ness to copied constant. */
3175 if (flag_mudflap && mf_marked_p (exp))
3176 mf_mark (desc->value);
3178 /* Create a string containing the label name, in LABEL. */
3179 labelno = const_labelno++;
3180 ASM_GENERATE_INTERNAL_LABEL (label, "LC", labelno);
3182 /* We have a symbol name; construct the SYMBOL_REF and the MEM. */
3183 if (use_object_blocks_p ())
3185 section *sect = get_constant_section (exp);
3186 symbol = create_block_symbol (ggc_strdup (label),
3187 get_block_for_section (sect), -1);
3189 else
3190 symbol = gen_rtx_SYMBOL_REF (Pmode, ggc_strdup (label));
3191 SYMBOL_REF_FLAGS (symbol) |= SYMBOL_FLAG_LOCAL;
3192 SET_SYMBOL_REF_DECL (symbol, desc->value);
3193 TREE_CONSTANT_POOL_ADDRESS_P (symbol) = 1;
3195 rtl = gen_rtx_MEM (TYPE_MODE (TREE_TYPE (exp)), symbol);
3196 set_mem_attributes (rtl, exp, 1);
3197 set_mem_alias_set (rtl, 0);
3198 set_mem_alias_set (rtl, const_alias_set);
3200 /* Set flags or add text to the name to record information, such as
3201 that it is a local symbol. If the name is changed, the macro
3202 ASM_OUTPUT_LABELREF will have to know how to strip this
3203 information. This call might invalidate our local variable
3204 SYMBOL; we can't use it afterward. */
3206 targetm.encode_section_info (exp, rtl, true);
3208 desc->rtl = rtl;
3210 return desc;
3213 /* Return an rtx representing a reference to constant data in memory
3214 for the constant expression EXP.
3216 If assembler code for such a constant has already been output,
3217 return an rtx to refer to it.
3218 Otherwise, output such a constant in memory
3219 and generate an rtx for it.
3221 If DEFER is nonzero, this constant can be deferred and output only
3222 if referenced in the function after all optimizations.
3224 `const_desc_table' records which constants already have label strings. */
3227 output_constant_def (tree exp, int defer)
3229 struct constant_descriptor_tree *desc;
3230 struct constant_descriptor_tree key;
3231 void **loc;
3233 /* Look up EXP in the table of constant descriptors. If we didn't find
3234 it, create a new one. */
3235 key.value = exp;
3236 key.hash = const_hash_1 (exp);
3237 loc = htab_find_slot_with_hash (const_desc_htab, &key, key.hash, INSERT);
3239 desc = (struct constant_descriptor_tree *) *loc;
3240 if (desc == 0)
3242 desc = build_constant_desc (exp);
3243 desc->hash = key.hash;
3244 *loc = desc;
3247 maybe_output_constant_def_contents (desc, defer);
3248 return desc->rtl;
3251 /* Subroutine of output_constant_def: Decide whether or not we need to
3252 output the constant DESC now, and if so, do it. */
3253 static void
3254 maybe_output_constant_def_contents (struct constant_descriptor_tree *desc,
3255 int defer)
3257 rtx symbol = XEXP (desc->rtl, 0);
3258 tree exp = desc->value;
3260 if (flag_syntax_only)
3261 return;
3263 if (TREE_ASM_WRITTEN (exp))
3264 /* Already output; don't do it again. */
3265 return;
3267 /* We can always defer constants as long as the context allows
3268 doing so. */
3269 if (defer)
3271 /* Increment n_deferred_constants if it exists. It needs to be at
3272 least as large as the number of constants actually referred to
3273 by the function. If it's too small we'll stop looking too early
3274 and fail to emit constants; if it's too large we'll only look
3275 through the entire function when we could have stopped earlier. */
3276 if (cfun)
3277 n_deferred_constants++;
3278 return;
3281 output_constant_def_contents (symbol);
3284 /* Subroutine of output_constant_def_contents. Output the definition
3285 of constant EXP, which is pointed to by label LABEL. ALIGN is the
3286 constant's alignment in bits. */
3288 static void
3289 assemble_constant_contents (tree exp, const char *label, unsigned int align)
3291 HOST_WIDE_INT size;
3293 size = get_constant_size (exp);
3295 /* Do any machine/system dependent processing of the constant. */
3296 #ifdef ASM_DECLARE_CONSTANT_NAME
3297 ASM_DECLARE_CONSTANT_NAME (asm_out_file, label, exp, size);
3298 #else
3299 /* Standard thing is just output label for the constant. */
3300 ASM_OUTPUT_LABEL (asm_out_file, label);
3301 #endif /* ASM_DECLARE_CONSTANT_NAME */
3303 /* Output the value of EXP. */
3304 output_constant (exp, size, align);
3307 /* We must output the constant data referred to by SYMBOL; do so. */
3309 static void
3310 output_constant_def_contents (rtx symbol)
3312 tree exp = SYMBOL_REF_DECL (symbol);
3313 unsigned int align;
3315 /* Make sure any other constants whose addresses appear in EXP
3316 are assigned label numbers. */
3317 output_addressed_constants (exp);
3319 /* We are no longer deferring this constant. */
3320 TREE_ASM_WRITTEN (exp) = 1;
3322 /* If the constant is part of an object block, make sure that the
3323 decl has been positioned within its block, but do not write out
3324 its definition yet. output_object_blocks will do that later. */
3325 if (SYMBOL_REF_HAS_BLOCK_INFO_P (symbol) && SYMBOL_REF_BLOCK (symbol))
3326 place_block_symbol (symbol);
3327 else
3329 switch_to_section (get_constant_section (exp));
3330 align = get_constant_alignment (exp);
3331 if (align > BITS_PER_UNIT)
3332 ASM_OUTPUT_ALIGN (asm_out_file, floor_log2 (align / BITS_PER_UNIT));
3333 assemble_constant_contents (exp, XSTR (symbol, 0), align);
3335 if (flag_mudflap)
3336 mudflap_enqueue_constant (exp);
3339 /* Look up EXP in the table of constant descriptors. Return the rtl
3340 if it has been emitted, else null. */
3343 lookup_constant_def (tree exp)
3345 struct constant_descriptor_tree *desc;
3346 struct constant_descriptor_tree key;
3348 key.value = exp;
3349 key.hash = const_hash_1 (exp);
3350 desc = (struct constant_descriptor_tree *)
3351 htab_find_with_hash (const_desc_htab, &key, key.hash);
3353 return (desc ? desc->rtl : NULL_RTX);
3356 /* Used in the hash tables to avoid outputting the same constant
3357 twice. Unlike 'struct constant_descriptor_tree', RTX constants
3358 are output once per function, not once per file. */
3359 /* ??? Only a few targets need per-function constant pools. Most
3360 can use one per-file pool. Should add a targetm bit to tell the
3361 difference. */
3363 struct rtx_constant_pool GTY(())
3365 /* Pointers to first and last constant in pool, as ordered by offset. */
3366 struct constant_descriptor_rtx *first;
3367 struct constant_descriptor_rtx *last;
3369 /* Hash facility for making memory-constants from constant rtl-expressions.
3370 It is used on RISC machines where immediate integer arguments and
3371 constant addresses are restricted so that such constants must be stored
3372 in memory. */
3373 htab_t GTY((param_is (struct constant_descriptor_rtx))) const_rtx_htab;
3375 /* Current offset in constant pool (does not include any
3376 machine-specific header). */
3377 HOST_WIDE_INT offset;
3380 struct constant_descriptor_rtx GTY((chain_next ("%h.next")))
3382 struct constant_descriptor_rtx *next;
3383 rtx mem;
3384 rtx sym;
3385 rtx constant;
3386 HOST_WIDE_INT offset;
3387 hashval_t hash;
3388 enum machine_mode mode;
3389 unsigned int align;
3390 int labelno;
3391 int mark;
3394 /* Hash and compare functions for const_rtx_htab. */
3396 static hashval_t
3397 const_desc_rtx_hash (const void *ptr)
3399 const struct constant_descriptor_rtx *const desc
3400 = (const struct constant_descriptor_rtx *) ptr;
3401 return desc->hash;
3404 static int
3405 const_desc_rtx_eq (const void *a, const void *b)
3407 const struct constant_descriptor_rtx *const x
3408 = (const struct constant_descriptor_rtx *) a;
3409 const struct constant_descriptor_rtx *const y
3410 = (const struct constant_descriptor_rtx *) b;
3412 if (x->mode != y->mode)
3413 return 0;
3414 return rtx_equal_p (x->constant, y->constant);
3417 /* This is the worker function for const_rtx_hash, called via for_each_rtx. */
3419 static int
3420 const_rtx_hash_1 (rtx *xp, void *data)
3422 unsigned HOST_WIDE_INT hwi;
3423 enum machine_mode mode;
3424 enum rtx_code code;
3425 hashval_t h, *hp;
3426 rtx x;
3428 x = *xp;
3429 code = GET_CODE (x);
3430 mode = GET_MODE (x);
3431 h = (hashval_t) code * 1048573 + mode;
3433 switch (code)
3435 case CONST_INT:
3436 hwi = INTVAL (x);
3437 fold_hwi:
3439 const int shift = sizeof (hashval_t) * CHAR_BIT;
3440 const int n = sizeof (HOST_WIDE_INT) / sizeof (hashval_t);
3441 int i;
3443 h ^= (hashval_t) hwi;
3444 for (i = 1; i < n; ++i)
3446 hwi >>= shift;
3447 h ^= (hashval_t) hwi;
3450 break;
3452 case CONST_DOUBLE:
3453 if (mode == VOIDmode)
3455 hwi = CONST_DOUBLE_LOW (x) ^ CONST_DOUBLE_HIGH (x);
3456 goto fold_hwi;
3458 else
3459 h ^= real_hash (CONST_DOUBLE_REAL_VALUE (x));
3460 break;
3462 case CONST_FIXED:
3463 h ^= fixed_hash (CONST_FIXED_VALUE (x));
3464 break;
3466 case CONST_VECTOR:
3468 int i;
3469 for (i = XVECLEN (x, 0); i-- > 0; )
3470 h = h * 251 + const_rtx_hash_1 (&XVECEXP (x, 0, i), data);
3472 break;
3474 case SYMBOL_REF:
3475 h ^= htab_hash_string (XSTR (x, 0));
3476 break;
3478 case LABEL_REF:
3479 h = h * 251 + CODE_LABEL_NUMBER (XEXP (x, 0));
3480 break;
3482 case UNSPEC:
3483 case UNSPEC_VOLATILE:
3484 h = h * 251 + XINT (x, 1);
3485 break;
3487 default:
3488 break;
3491 hp = (hashval_t *) data;
3492 *hp = *hp * 509 + h;
3493 return 0;
3496 /* Compute a hash value for X, which should be a constant. */
3498 static hashval_t
3499 const_rtx_hash (rtx x)
3501 hashval_t h = 0;
3502 for_each_rtx (&x, const_rtx_hash_1, &h);
3503 return h;
3507 /* Create and return a new rtx constant pool. */
3509 static struct rtx_constant_pool *
3510 create_constant_pool (void)
3512 struct rtx_constant_pool *pool;
3514 pool = GGC_NEW (struct rtx_constant_pool);
3515 pool->const_rtx_htab = htab_create_ggc (31, const_desc_rtx_hash,
3516 const_desc_rtx_eq, NULL);
3517 pool->first = NULL;
3518 pool->last = NULL;
3519 pool->offset = 0;
3520 return pool;
3523 /* Initialize constant pool hashing for a new function. */
3525 void
3526 init_varasm_status (void)
3528 crtl->varasm.pool = create_constant_pool ();
3529 crtl->varasm.deferred_constants = 0;
3532 /* Given a MINUS expression, simplify it if both sides
3533 include the same symbol. */
3536 simplify_subtraction (rtx x)
3538 rtx r = simplify_rtx (x);
3539 return r ? r : x;
3542 /* Given a constant rtx X, make (or find) a memory constant for its value
3543 and return a MEM rtx to refer to it in memory. */
3546 force_const_mem (enum machine_mode mode, rtx x)
3548 struct constant_descriptor_rtx *desc, tmp;
3549 struct rtx_constant_pool *pool;
3550 char label[256];
3551 rtx def, symbol;
3552 hashval_t hash;
3553 unsigned int align;
3554 void **slot;
3556 /* If we're not allowed to drop X into the constant pool, don't. */
3557 if (targetm.cannot_force_const_mem (x))
3558 return NULL_RTX;
3560 /* Record that this function has used a constant pool entry. */
3561 crtl->uses_const_pool = 1;
3563 /* Decide which pool to use. */
3564 pool = (targetm.use_blocks_for_constant_p (mode, x)
3565 ? shared_constant_pool
3566 : crtl->varasm.pool);
3568 /* Lookup the value in the hashtable. */
3569 tmp.constant = x;
3570 tmp.mode = mode;
3571 hash = const_rtx_hash (x);
3572 slot = htab_find_slot_with_hash (pool->const_rtx_htab, &tmp, hash, INSERT);
3573 desc = (struct constant_descriptor_rtx *) *slot;
3575 /* If the constant was already present, return its memory. */
3576 if (desc)
3577 return copy_rtx (desc->mem);
3579 /* Otherwise, create a new descriptor. */
3580 desc = GGC_NEW (struct constant_descriptor_rtx);
3581 *slot = desc;
3583 /* Align the location counter as required by EXP's data type. */
3584 align = GET_MODE_ALIGNMENT (mode == VOIDmode ? word_mode : mode);
3585 #ifdef CONSTANT_ALIGNMENT
3587 tree type = lang_hooks.types.type_for_mode (mode, 0);
3588 if (type != NULL_TREE)
3589 align = CONSTANT_ALIGNMENT (make_tree (type, x), align);
3591 #endif
3593 pool->offset += (align / BITS_PER_UNIT) - 1;
3594 pool->offset &= ~ ((align / BITS_PER_UNIT) - 1);
3596 desc->next = NULL;
3597 desc->constant = tmp.constant;
3598 desc->offset = pool->offset;
3599 desc->hash = hash;
3600 desc->mode = mode;
3601 desc->align = align;
3602 desc->labelno = const_labelno;
3603 desc->mark = 0;
3605 pool->offset += GET_MODE_SIZE (mode);
3606 if (pool->last)
3607 pool->last->next = desc;
3608 else
3609 pool->first = pool->last = desc;
3610 pool->last = desc;
3612 /* Create a string containing the label name, in LABEL. */
3613 ASM_GENERATE_INTERNAL_LABEL (label, "LC", const_labelno);
3614 ++const_labelno;
3616 /* Construct the SYMBOL_REF. Make sure to mark it as belonging to
3617 the constants pool. */
3618 if (use_object_blocks_p () && targetm.use_blocks_for_constant_p (mode, x))
3620 section *sect = targetm.asm_out.select_rtx_section (mode, x, align);
3621 symbol = create_block_symbol (ggc_strdup (label),
3622 get_block_for_section (sect), -1);
3624 else
3625 symbol = gen_rtx_SYMBOL_REF (Pmode, ggc_strdup (label));
3626 desc->sym = symbol;
3627 SYMBOL_REF_FLAGS (symbol) |= SYMBOL_FLAG_LOCAL;
3628 CONSTANT_POOL_ADDRESS_P (symbol) = 1;
3629 SET_SYMBOL_REF_CONSTANT (symbol, desc);
3631 /* Construct the MEM. */
3632 desc->mem = def = gen_const_mem (mode, symbol);
3633 set_mem_attributes (def, lang_hooks.types.type_for_mode (mode, 0), 1);
3634 set_mem_align (def, align);
3636 /* If we're dropping a label to the constant pool, make sure we
3637 don't delete it. */
3638 if (GET_CODE (x) == LABEL_REF)
3639 LABEL_PRESERVE_P (XEXP (x, 0)) = 1;
3641 return copy_rtx (def);
3644 /* Given a constant pool SYMBOL_REF, return the corresponding constant. */
3647 get_pool_constant (rtx addr)
3649 return SYMBOL_REF_CONSTANT (addr)->constant;
3652 /* Given a constant pool SYMBOL_REF, return the corresponding constant
3653 and whether it has been output or not. */
3656 get_pool_constant_mark (rtx addr, bool *pmarked)
3658 struct constant_descriptor_rtx *desc;
3660 desc = SYMBOL_REF_CONSTANT (addr);
3661 *pmarked = (desc->mark != 0);
3662 return desc->constant;
3665 /* Similar, return the mode. */
3667 enum machine_mode
3668 get_pool_mode (const_rtx addr)
3670 return SYMBOL_REF_CONSTANT (addr)->mode;
3673 /* Return the size of the constant pool. */
3676 get_pool_size (void)
3678 return crtl->varasm.pool->offset;
3681 /* Worker function for output_constant_pool_1. Emit assembly for X
3682 in MODE with known alignment ALIGN. */
3684 static void
3685 output_constant_pool_2 (enum machine_mode mode, rtx x, unsigned int align)
3687 switch (GET_MODE_CLASS (mode))
3689 case MODE_FLOAT:
3690 case MODE_DECIMAL_FLOAT:
3692 REAL_VALUE_TYPE r;
3694 gcc_assert (GET_CODE (x) == CONST_DOUBLE);
3695 REAL_VALUE_FROM_CONST_DOUBLE (r, x);
3696 assemble_real (r, mode, align);
3697 break;
3700 case MODE_INT:
3701 case MODE_PARTIAL_INT:
3702 case MODE_FRACT:
3703 case MODE_UFRACT:
3704 case MODE_ACCUM:
3705 case MODE_UACCUM:
3706 assemble_integer (x, GET_MODE_SIZE (mode), align, 1);
3707 break;
3709 case MODE_VECTOR_FLOAT:
3710 case MODE_VECTOR_INT:
3711 case MODE_VECTOR_FRACT:
3712 case MODE_VECTOR_UFRACT:
3713 case MODE_VECTOR_ACCUM:
3714 case MODE_VECTOR_UACCUM:
3716 int i, units;
3717 enum machine_mode submode = GET_MODE_INNER (mode);
3718 unsigned int subalign = MIN (align, GET_MODE_BITSIZE (submode));
3720 gcc_assert (GET_CODE (x) == CONST_VECTOR);
3721 units = CONST_VECTOR_NUNITS (x);
3723 for (i = 0; i < units; i++)
3725 rtx elt = CONST_VECTOR_ELT (x, i);
3726 output_constant_pool_2 (submode, elt, i ? subalign : align);
3729 break;
3731 default:
3732 gcc_unreachable ();
3736 /* Worker function for output_constant_pool. Emit constant DESC,
3737 giving it ALIGN bits of alignment. */
3739 static void
3740 output_constant_pool_1 (struct constant_descriptor_rtx *desc,
3741 unsigned int align)
3743 rtx x, tmp;
3745 x = desc->constant;
3747 /* See if X is a LABEL_REF (or a CONST referring to a LABEL_REF)
3748 whose CODE_LABEL has been deleted. This can occur if a jump table
3749 is eliminated by optimization. If so, write a constant of zero
3750 instead. Note that this can also happen by turning the
3751 CODE_LABEL into a NOTE. */
3752 /* ??? This seems completely and utterly wrong. Certainly it's
3753 not true for NOTE_INSN_DELETED_LABEL, but I disbelieve proper
3754 functioning even with INSN_DELETED_P and friends. */
3756 tmp = x;
3757 switch (GET_CODE (tmp))
3759 case CONST:
3760 if (GET_CODE (XEXP (tmp, 0)) != PLUS
3761 || GET_CODE (XEXP (XEXP (tmp, 0), 0)) != LABEL_REF)
3762 break;
3763 tmp = XEXP (XEXP (tmp, 0), 0);
3764 /* FALLTHRU */
3766 case LABEL_REF:
3767 tmp = XEXP (tmp, 0);
3768 gcc_assert (!INSN_DELETED_P (tmp));
3769 gcc_assert (!NOTE_P (tmp)
3770 || NOTE_KIND (tmp) != NOTE_INSN_DELETED);
3771 break;
3773 default:
3774 break;
3777 #ifdef ASM_OUTPUT_SPECIAL_POOL_ENTRY
3778 ASM_OUTPUT_SPECIAL_POOL_ENTRY (asm_out_file, x, desc->mode,
3779 align, desc->labelno, done);
3780 #endif
3782 assemble_align (align);
3784 /* Output the label. */
3785 targetm.asm_out.internal_label (asm_out_file, "LC", desc->labelno);
3787 /* Output the data. */
3788 output_constant_pool_2 (desc->mode, x, align);
3790 /* Make sure all constants in SECTION_MERGE and not SECTION_STRINGS
3791 sections have proper size. */
3792 if (align > GET_MODE_BITSIZE (desc->mode)
3793 && in_section
3794 && (in_section->common.flags & SECTION_MERGE))
3795 assemble_align (align);
3797 #ifdef ASM_OUTPUT_SPECIAL_POOL_ENTRY
3798 done:
3799 #endif
3800 return;
3803 /* Given a SYMBOL_REF CURRENT_RTX, mark it and all constants it refers
3804 to as used. Emit referenced deferred strings. This function can
3805 be used with for_each_rtx to mark all SYMBOL_REFs in an rtx. */
3807 static int
3808 mark_constant (rtx *current_rtx, void *data ATTRIBUTE_UNUSED)
3810 rtx x = *current_rtx;
3812 if (x == NULL_RTX || GET_CODE (x) != SYMBOL_REF)
3813 return 0;
3815 if (CONSTANT_POOL_ADDRESS_P (x))
3817 struct constant_descriptor_rtx *desc = SYMBOL_REF_CONSTANT (x);
3818 if (desc->mark == 0)
3820 desc->mark = 1;
3821 for_each_rtx (&desc->constant, mark_constant, NULL);
3824 else if (TREE_CONSTANT_POOL_ADDRESS_P (x))
3826 tree exp = SYMBOL_REF_DECL (x);
3827 if (!TREE_ASM_WRITTEN (exp))
3829 n_deferred_constants--;
3830 output_constant_def_contents (x);
3834 return -1;
3837 /* Look through appropriate parts of INSN, marking all entries in the
3838 constant pool which are actually being used. Entries that are only
3839 referenced by other constants are also marked as used. Emit
3840 deferred strings that are used. */
3842 static void
3843 mark_constants (rtx insn)
3845 if (!INSN_P (insn))
3846 return;
3848 /* Insns may appear inside a SEQUENCE. Only check the patterns of
3849 insns, not any notes that may be attached. We don't want to mark
3850 a constant just because it happens to appear in a REG_EQUIV note. */
3851 if (GET_CODE (PATTERN (insn)) == SEQUENCE)
3853 rtx seq = PATTERN (insn);
3854 int i, n = XVECLEN (seq, 0);
3855 for (i = 0; i < n; ++i)
3857 rtx subinsn = XVECEXP (seq, 0, i);
3858 if (INSN_P (subinsn))
3859 for_each_rtx (&PATTERN (subinsn), mark_constant, NULL);
3862 else
3863 for_each_rtx (&PATTERN (insn), mark_constant, NULL);
3866 /* Look through the instructions for this function, and mark all the
3867 entries in POOL which are actually being used. Emit deferred constants
3868 which have indeed been used. */
3870 static void
3871 mark_constant_pool (void)
3873 rtx insn, link;
3875 if (!crtl->uses_const_pool && n_deferred_constants == 0)
3876 return;
3878 for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
3879 mark_constants (insn);
3881 for (link = crtl->epilogue_delay_list;
3882 link;
3883 link = XEXP (link, 1))
3884 mark_constants (XEXP (link, 0));
3887 /* Write all the constants in POOL. */
3889 static void
3890 output_constant_pool_contents (struct rtx_constant_pool *pool)
3892 struct constant_descriptor_rtx *desc;
3894 for (desc = pool->first; desc ; desc = desc->next)
3895 if (desc->mark)
3897 /* If the constant is part of an object_block, make sure that
3898 the constant has been positioned within its block, but do not
3899 write out its definition yet. output_object_blocks will do
3900 that later. */
3901 if (SYMBOL_REF_HAS_BLOCK_INFO_P (desc->sym)
3902 && SYMBOL_REF_BLOCK (desc->sym))
3903 place_block_symbol (desc->sym);
3904 else
3906 switch_to_section (targetm.asm_out.select_rtx_section
3907 (desc->mode, desc->constant, desc->align));
3908 output_constant_pool_1 (desc, desc->align);
3913 /* Mark all constants that are used in the current function, then write
3914 out the function's private constant pool. */
3916 static void
3917 output_constant_pool (const char *fnname ATTRIBUTE_UNUSED,
3918 tree fndecl ATTRIBUTE_UNUSED)
3920 struct rtx_constant_pool *pool = crtl->varasm.pool;
3922 /* It is possible for gcc to call force_const_mem and then to later
3923 discard the instructions which refer to the constant. In such a
3924 case we do not need to output the constant. */
3925 mark_constant_pool ();
3927 #ifdef ASM_OUTPUT_POOL_PROLOGUE
3928 ASM_OUTPUT_POOL_PROLOGUE (asm_out_file, fnname, fndecl, pool->offset);
3929 #endif
3931 output_constant_pool_contents (pool);
3933 #ifdef ASM_OUTPUT_POOL_EPILOGUE
3934 ASM_OUTPUT_POOL_EPILOGUE (asm_out_file, fnname, fndecl, pool->offset);
3935 #endif
3938 /* Write the contents of the shared constant pool. */
3940 void
3941 output_shared_constant_pool (void)
3943 output_constant_pool_contents (shared_constant_pool);
3946 /* Determine what kind of relocations EXP may need. */
3949 compute_reloc_for_constant (tree exp)
3951 int reloc = 0, reloc2;
3952 tree tem;
3954 switch (TREE_CODE (exp))
3956 case ADDR_EXPR:
3957 case FDESC_EXPR:
3958 /* Go inside any operations that get_inner_reference can handle and see
3959 if what's inside is a constant: no need to do anything here for
3960 addresses of variables or functions. */
3961 for (tem = TREE_OPERAND (exp, 0); handled_component_p (tem);
3962 tem = TREE_OPERAND (tem, 0))
3965 if (TREE_PUBLIC (tem))
3966 reloc |= 2;
3967 else
3968 reloc |= 1;
3969 break;
3971 case PLUS_EXPR:
3972 case POINTER_PLUS_EXPR:
3973 reloc = compute_reloc_for_constant (TREE_OPERAND (exp, 0));
3974 reloc |= compute_reloc_for_constant (TREE_OPERAND (exp, 1));
3975 break;
3977 case MINUS_EXPR:
3978 reloc = compute_reloc_for_constant (TREE_OPERAND (exp, 0));
3979 reloc2 = compute_reloc_for_constant (TREE_OPERAND (exp, 1));
3980 /* The difference of two local labels is computable at link time. */
3981 if (reloc == 1 && reloc2 == 1)
3982 reloc = 0;
3983 else
3984 reloc |= reloc2;
3985 break;
3987 CASE_CONVERT:
3988 case VIEW_CONVERT_EXPR:
3989 reloc = compute_reloc_for_constant (TREE_OPERAND (exp, 0));
3990 break;
3992 case CONSTRUCTOR:
3994 unsigned HOST_WIDE_INT idx;
3995 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (exp), idx, tem)
3996 if (tem != 0)
3997 reloc |= compute_reloc_for_constant (tem);
3999 break;
4001 default:
4002 break;
4004 return reloc;
4007 /* Find all the constants whose addresses are referenced inside of EXP,
4008 and make sure assembler code with a label has been output for each one.
4009 Indicate whether an ADDR_EXPR has been encountered. */
4011 static void
4012 output_addressed_constants (tree exp)
4014 tree tem;
4016 switch (TREE_CODE (exp))
4018 case ADDR_EXPR:
4019 case FDESC_EXPR:
4020 /* Go inside any operations that get_inner_reference can handle and see
4021 if what's inside is a constant: no need to do anything here for
4022 addresses of variables or functions. */
4023 for (tem = TREE_OPERAND (exp, 0); handled_component_p (tem);
4024 tem = TREE_OPERAND (tem, 0))
4027 /* If we have an initialized CONST_DECL, retrieve the initializer. */
4028 if (TREE_CODE (tem) == CONST_DECL && DECL_INITIAL (tem))
4029 tem = DECL_INITIAL (tem);
4031 if (CONSTANT_CLASS_P (tem) || TREE_CODE (tem) == CONSTRUCTOR)
4032 output_constant_def (tem, 0);
4033 break;
4035 case PLUS_EXPR:
4036 case POINTER_PLUS_EXPR:
4037 case MINUS_EXPR:
4038 output_addressed_constants (TREE_OPERAND (exp, 1));
4039 /* Fall through. */
4041 CASE_CONVERT:
4042 case VIEW_CONVERT_EXPR:
4043 output_addressed_constants (TREE_OPERAND (exp, 0));
4044 break;
4046 case CONSTRUCTOR:
4048 unsigned HOST_WIDE_INT idx;
4049 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (exp), idx, tem)
4050 if (tem != 0)
4051 output_addressed_constants (tem);
4053 break;
4055 default:
4056 break;
4060 /* Whether a constructor CTOR is a valid static constant initializer if all
4061 its elements are. This used to be internal to initializer_constant_valid_p
4062 and has been exposed to let other functions like categorize_ctor_elements
4063 evaluate the property while walking a constructor for other purposes. */
4065 bool
4066 constructor_static_from_elts_p (const_tree ctor)
4068 return (TREE_CONSTANT (ctor)
4069 && (TREE_CODE (TREE_TYPE (ctor)) == UNION_TYPE
4070 || TREE_CODE (TREE_TYPE (ctor)) == RECORD_TYPE)
4071 && !VEC_empty (constructor_elt, CONSTRUCTOR_ELTS (ctor)));
4074 /* A subroutine of initializer_constant_valid_p. VALUE is either a
4075 MINUS_EXPR or a POINTER_PLUS_EXPR. This looks for cases of VALUE
4076 which are valid when ENDTYPE is an integer of any size; in
4077 particular, this does not accept a pointer minus a constant. This
4078 returns null_pointer_node if the VALUE is an absolute constant
4079 which can be used to initialize a static variable. Otherwise it
4080 returns NULL. */
4082 static tree
4083 narrowing_initializer_constant_valid_p (tree value, tree endtype)
4085 tree op0, op1;
4087 if (!INTEGRAL_TYPE_P (endtype))
4088 return NULL_TREE;
4090 op0 = TREE_OPERAND (value, 0);
4091 op1 = TREE_OPERAND (value, 1);
4093 /* Like STRIP_NOPS except allow the operand mode to widen. This
4094 works around a feature of fold that simplifies (int)(p1 - p2) to
4095 ((int)p1 - (int)p2) under the theory that the narrower operation
4096 is cheaper. */
4098 while (CONVERT_EXPR_P (op0)
4099 || TREE_CODE (op0) == NON_LVALUE_EXPR)
4101 tree inner = TREE_OPERAND (op0, 0);
4102 if (inner == error_mark_node
4103 || ! INTEGRAL_MODE_P (TYPE_MODE (TREE_TYPE (inner)))
4104 || (GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op0)))
4105 > GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (inner)))))
4106 break;
4107 op0 = inner;
4110 while (CONVERT_EXPR_P (op1)
4111 || TREE_CODE (op1) == NON_LVALUE_EXPR)
4113 tree inner = TREE_OPERAND (op1, 0);
4114 if (inner == error_mark_node
4115 || ! INTEGRAL_MODE_P (TYPE_MODE (TREE_TYPE (inner)))
4116 || (GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op1)))
4117 > GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (inner)))))
4118 break;
4119 op1 = inner;
4122 op0 = initializer_constant_valid_p (op0, endtype);
4123 op1 = initializer_constant_valid_p (op1, endtype);
4125 /* Both initializers must be known. */
4126 if (op0 && op1)
4128 if (op0 == op1)
4129 return null_pointer_node;
4131 /* Support differences between labels. */
4132 if (TREE_CODE (op0) == LABEL_DECL
4133 && TREE_CODE (op1) == LABEL_DECL)
4134 return null_pointer_node;
4136 if (TREE_CODE (op0) == STRING_CST
4137 && TREE_CODE (op1) == STRING_CST
4138 && operand_equal_p (op0, op1, 1))
4139 return null_pointer_node;
4142 return NULL_TREE;
4145 /* Return nonzero if VALUE is a valid constant-valued expression
4146 for use in initializing a static variable; one that can be an
4147 element of a "constant" initializer.
4149 Return null_pointer_node if the value is absolute;
4150 if it is relocatable, return the variable that determines the relocation.
4151 We assume that VALUE has been folded as much as possible;
4152 therefore, we do not need to check for such things as
4153 arithmetic-combinations of integers. */
4155 tree
4156 initializer_constant_valid_p (tree value, tree endtype)
4158 tree ret;
4160 switch (TREE_CODE (value))
4162 case CONSTRUCTOR:
4163 if (constructor_static_from_elts_p (value))
4165 unsigned HOST_WIDE_INT idx;
4166 tree elt;
4167 bool absolute = true;
4169 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (value), idx, elt)
4171 tree reloc;
4172 reloc = initializer_constant_valid_p (elt, TREE_TYPE (elt));
4173 if (!reloc)
4174 return NULL_TREE;
4175 if (reloc != null_pointer_node)
4176 absolute = false;
4178 /* For a non-absolute relocation, there is no single
4179 variable that can be "the variable that determines the
4180 relocation." */
4181 return absolute ? null_pointer_node : error_mark_node;
4184 return TREE_STATIC (value) ? null_pointer_node : NULL_TREE;
4186 case INTEGER_CST:
4187 case VECTOR_CST:
4188 case REAL_CST:
4189 case FIXED_CST:
4190 case STRING_CST:
4191 case COMPLEX_CST:
4192 return null_pointer_node;
4194 case ADDR_EXPR:
4195 case FDESC_EXPR:
4197 tree op0 = staticp (TREE_OPERAND (value, 0));
4198 if (op0)
4200 /* "&(*a).f" is like unto pointer arithmetic. If "a" turns out
4201 to be a constant, this is old-skool offsetof-like nonsense. */
4202 if (TREE_CODE (op0) == INDIRECT_REF
4203 && TREE_CONSTANT (TREE_OPERAND (op0, 0)))
4204 return null_pointer_node;
4205 /* Taking the address of a nested function involves a trampoline,
4206 unless we don't need or want one. */
4207 if (TREE_CODE (op0) == FUNCTION_DECL
4208 && decl_function_context (op0)
4209 && !DECL_NO_STATIC_CHAIN (op0)
4210 && !TREE_NO_TRAMPOLINE (value))
4211 return NULL_TREE;
4212 /* "&{...}" requires a temporary to hold the constructed
4213 object. */
4214 if (TREE_CODE (op0) == CONSTRUCTOR)
4215 return NULL_TREE;
4217 return op0;
4220 case NON_LVALUE_EXPR:
4221 return initializer_constant_valid_p (TREE_OPERAND (value, 0), endtype);
4223 case VIEW_CONVERT_EXPR:
4225 tree src = TREE_OPERAND (value, 0);
4226 tree src_type = TREE_TYPE (src);
4227 tree dest_type = TREE_TYPE (value);
4229 /* Allow view-conversions from aggregate to non-aggregate type only
4230 if the bit pattern is fully preserved afterwards; otherwise, the
4231 RTL expander won't be able to apply a subsequent transformation
4232 to the underlying constructor. */
4233 if (AGGREGATE_TYPE_P (src_type) && !AGGREGATE_TYPE_P (dest_type))
4235 if (TYPE_MODE (endtype) == TYPE_MODE (dest_type))
4236 return initializer_constant_valid_p (src, endtype);
4237 else
4238 return NULL_TREE;
4241 /* Allow all other kinds of view-conversion. */
4242 return initializer_constant_valid_p (src, endtype);
4245 CASE_CONVERT:
4247 tree src = TREE_OPERAND (value, 0);
4248 tree src_type = TREE_TYPE (src);
4249 tree dest_type = TREE_TYPE (value);
4251 /* Allow conversions between pointer types, floating-point
4252 types, and offset types. */
4253 if ((POINTER_TYPE_P (dest_type) && POINTER_TYPE_P (src_type))
4254 || (FLOAT_TYPE_P (dest_type) && FLOAT_TYPE_P (src_type))
4255 || (TREE_CODE (dest_type) == OFFSET_TYPE
4256 && TREE_CODE (src_type) == OFFSET_TYPE))
4257 return initializer_constant_valid_p (src, endtype);
4259 /* Allow length-preserving conversions between integer types. */
4260 if (INTEGRAL_TYPE_P (dest_type) && INTEGRAL_TYPE_P (src_type)
4261 && (TYPE_PRECISION (dest_type) == TYPE_PRECISION (src_type)))
4262 return initializer_constant_valid_p (src, endtype);
4264 /* Allow conversions between other integer types only if
4265 explicit value. */
4266 if (INTEGRAL_TYPE_P (dest_type) && INTEGRAL_TYPE_P (src_type))
4268 tree inner = initializer_constant_valid_p (src, endtype);
4269 if (inner == null_pointer_node)
4270 return null_pointer_node;
4271 break;
4274 /* Allow (int) &foo provided int is as wide as a pointer. */
4275 if (INTEGRAL_TYPE_P (dest_type) && POINTER_TYPE_P (src_type)
4276 && (TYPE_PRECISION (dest_type) >= TYPE_PRECISION (src_type)))
4277 return initializer_constant_valid_p (src, endtype);
4279 /* Likewise conversions from int to pointers, but also allow
4280 conversions from 0. */
4281 if ((POINTER_TYPE_P (dest_type)
4282 || TREE_CODE (dest_type) == OFFSET_TYPE)
4283 && INTEGRAL_TYPE_P (src_type))
4285 if (TREE_CODE (src) == INTEGER_CST
4286 && TYPE_PRECISION (dest_type) >= TYPE_PRECISION (src_type))
4287 return null_pointer_node;
4288 if (integer_zerop (src))
4289 return null_pointer_node;
4290 else if (TYPE_PRECISION (dest_type) <= TYPE_PRECISION (src_type))
4291 return initializer_constant_valid_p (src, endtype);
4294 /* Allow conversions to struct or union types if the value
4295 inside is okay. */
4296 if (TREE_CODE (dest_type) == RECORD_TYPE
4297 || TREE_CODE (dest_type) == UNION_TYPE)
4298 return initializer_constant_valid_p (src, endtype);
4300 break;
4302 case POINTER_PLUS_EXPR:
4303 case PLUS_EXPR:
4304 if (! INTEGRAL_TYPE_P (endtype)
4305 || TYPE_PRECISION (endtype) >= POINTER_SIZE)
4307 tree valid0 = initializer_constant_valid_p (TREE_OPERAND (value, 0),
4308 endtype);
4309 tree valid1 = initializer_constant_valid_p (TREE_OPERAND (value, 1),
4310 endtype);
4311 /* If either term is absolute, use the other term's relocation. */
4312 if (valid0 == null_pointer_node)
4313 return valid1;
4314 if (valid1 == null_pointer_node)
4315 return valid0;
4318 /* Support narrowing pointer differences. */
4319 if (TREE_CODE (value) == POINTER_PLUS_EXPR)
4321 ret = narrowing_initializer_constant_valid_p (value, endtype);
4322 if (ret != NULL_TREE)
4323 return ret;
4325 break;
4327 case MINUS_EXPR:
4328 if (! INTEGRAL_TYPE_P (endtype)
4329 || TYPE_PRECISION (endtype) >= POINTER_SIZE)
4331 tree valid0 = initializer_constant_valid_p (TREE_OPERAND (value, 0),
4332 endtype);
4333 tree valid1 = initializer_constant_valid_p (TREE_OPERAND (value, 1),
4334 endtype);
4335 /* Win if second argument is absolute. */
4336 if (valid1 == null_pointer_node)
4337 return valid0;
4338 /* Win if both arguments have the same relocation.
4339 Then the value is absolute. */
4340 if (valid0 == valid1 && valid0 != 0)
4341 return null_pointer_node;
4343 /* Since GCC guarantees that string constants are unique in the
4344 generated code, a subtraction between two copies of the same
4345 constant string is absolute. */
4346 if (valid0 && TREE_CODE (valid0) == STRING_CST
4347 && valid1 && TREE_CODE (valid1) == STRING_CST
4348 && operand_equal_p (valid0, valid1, 1))
4349 return null_pointer_node;
4352 /* Support narrowing differences. */
4353 ret = narrowing_initializer_constant_valid_p (value, endtype);
4354 if (ret != NULL_TREE)
4355 return ret;
4357 break;
4359 default:
4360 break;
4363 return 0;
4366 /* Output assembler code for constant EXP to FILE, with no label.
4367 This includes the pseudo-op such as ".int" or ".byte", and a newline.
4368 Assumes output_addressed_constants has been done on EXP already.
4370 Generate exactly SIZE bytes of assembler data, padding at the end
4371 with zeros if necessary. SIZE must always be specified.
4373 SIZE is important for structure constructors,
4374 since trailing members may have been omitted from the constructor.
4375 It is also important for initialization of arrays from string constants
4376 since the full length of the string constant might not be wanted.
4377 It is also needed for initialization of unions, where the initializer's
4378 type is just one member, and that may not be as long as the union.
4380 There a case in which we would fail to output exactly SIZE bytes:
4381 for a structure constructor that wants to produce more than SIZE bytes.
4382 But such constructors will never be generated for any possible input.
4384 ALIGN is the alignment of the data in bits. */
4386 void
4387 output_constant (tree exp, unsigned HOST_WIDE_INT size, unsigned int align)
4389 enum tree_code code;
4390 unsigned HOST_WIDE_INT thissize;
4392 if (size == 0 || flag_syntax_only)
4393 return;
4395 /* See if we're trying to initialize a pointer in a non-default mode
4396 to the address of some declaration somewhere. If the target says
4397 the mode is valid for pointers, assume the target has a way of
4398 resolving it. */
4399 if (TREE_CODE (exp) == NOP_EXPR
4400 && POINTER_TYPE_P (TREE_TYPE (exp))
4401 && targetm.valid_pointer_mode (TYPE_MODE (TREE_TYPE (exp))))
4403 tree saved_type = TREE_TYPE (exp);
4405 /* Peel off any intermediate conversions-to-pointer for valid
4406 pointer modes. */
4407 while (TREE_CODE (exp) == NOP_EXPR
4408 && POINTER_TYPE_P (TREE_TYPE (exp))
4409 && targetm.valid_pointer_mode (TYPE_MODE (TREE_TYPE (exp))))
4410 exp = TREE_OPERAND (exp, 0);
4412 /* If what we're left with is the address of something, we can
4413 convert the address to the final type and output it that
4414 way. */
4415 if (TREE_CODE (exp) == ADDR_EXPR)
4416 exp = build1 (ADDR_EXPR, saved_type, TREE_OPERAND (exp, 0));
4417 /* Likewise for constant ints. */
4418 else if (TREE_CODE (exp) == INTEGER_CST)
4419 exp = build_int_cst_wide (saved_type, TREE_INT_CST_LOW (exp),
4420 TREE_INT_CST_HIGH (exp));
4424 /* Eliminate any conversions since we'll be outputting the underlying
4425 constant. */
4426 while (CONVERT_EXPR_P (exp)
4427 || TREE_CODE (exp) == NON_LVALUE_EXPR
4428 || TREE_CODE (exp) == VIEW_CONVERT_EXPR)
4430 HOST_WIDE_INT type_size = int_size_in_bytes (TREE_TYPE (exp));
4431 HOST_WIDE_INT op_size = int_size_in_bytes (TREE_TYPE (TREE_OPERAND (exp, 0)));
4433 /* Make sure eliminating the conversion is really a no-op, except with
4434 VIEW_CONVERT_EXPRs to allow for wild Ada unchecked conversions and
4435 union types to allow for Ada unchecked unions. */
4436 if (type_size > op_size
4437 && TREE_CODE (exp) != VIEW_CONVERT_EXPR
4438 && TREE_CODE (TREE_TYPE (exp)) != UNION_TYPE)
4439 /* Keep the conversion. */
4440 break;
4441 else
4442 exp = TREE_OPERAND (exp, 0);
4445 code = TREE_CODE (TREE_TYPE (exp));
4446 thissize = int_size_in_bytes (TREE_TYPE (exp));
4448 /* Allow a constructor with no elements for any data type.
4449 This means to fill the space with zeros. */
4450 if (TREE_CODE (exp) == CONSTRUCTOR
4451 && VEC_empty (constructor_elt, CONSTRUCTOR_ELTS (exp)))
4453 assemble_zeros (size);
4454 return;
4457 if (TREE_CODE (exp) == FDESC_EXPR)
4459 #ifdef ASM_OUTPUT_FDESC
4460 HOST_WIDE_INT part = tree_low_cst (TREE_OPERAND (exp, 1), 0);
4461 tree decl = TREE_OPERAND (exp, 0);
4462 ASM_OUTPUT_FDESC (asm_out_file, decl, part);
4463 #else
4464 gcc_unreachable ();
4465 #endif
4466 return;
4469 /* Now output the underlying data. If we've handling the padding, return.
4470 Otherwise, break and ensure SIZE is the size written. */
4471 switch (code)
4473 case BOOLEAN_TYPE:
4474 case INTEGER_TYPE:
4475 case ENUMERAL_TYPE:
4476 case POINTER_TYPE:
4477 case REFERENCE_TYPE:
4478 case OFFSET_TYPE:
4479 case FIXED_POINT_TYPE:
4480 if (! assemble_integer (expand_expr (exp, NULL_RTX, VOIDmode,
4481 EXPAND_INITIALIZER),
4482 MIN (size, thissize), align, 0))
4483 error ("initializer for integer/fixed-point value is too complicated");
4484 break;
4486 case REAL_TYPE:
4487 if (TREE_CODE (exp) != REAL_CST)
4488 error ("initializer for floating value is not a floating constant");
4490 assemble_real (TREE_REAL_CST (exp), TYPE_MODE (TREE_TYPE (exp)), align);
4491 break;
4493 case COMPLEX_TYPE:
4494 output_constant (TREE_REALPART (exp), thissize / 2, align);
4495 output_constant (TREE_IMAGPART (exp), thissize / 2,
4496 min_align (align, BITS_PER_UNIT * (thissize / 2)));
4497 break;
4499 case ARRAY_TYPE:
4500 case VECTOR_TYPE:
4501 switch (TREE_CODE (exp))
4503 case CONSTRUCTOR:
4504 output_constructor (exp, size, align);
4505 return;
4506 case STRING_CST:
4507 thissize = MIN ((unsigned HOST_WIDE_INT)TREE_STRING_LENGTH (exp),
4508 size);
4509 assemble_string (TREE_STRING_POINTER (exp), thissize);
4510 break;
4512 case VECTOR_CST:
4514 int elt_size;
4515 tree link;
4516 unsigned int nalign;
4517 enum machine_mode inner;
4519 inner = TYPE_MODE (TREE_TYPE (TREE_TYPE (exp)));
4520 nalign = MIN (align, GET_MODE_ALIGNMENT (inner));
4522 elt_size = GET_MODE_SIZE (inner);
4524 link = TREE_VECTOR_CST_ELTS (exp);
4525 output_constant (TREE_VALUE (link), elt_size, align);
4526 thissize = elt_size;
4527 while ((link = TREE_CHAIN (link)) != NULL)
4529 output_constant (TREE_VALUE (link), elt_size, nalign);
4530 thissize += elt_size;
4532 break;
4534 default:
4535 gcc_unreachable ();
4537 break;
4539 case RECORD_TYPE:
4540 case UNION_TYPE:
4541 gcc_assert (TREE_CODE (exp) == CONSTRUCTOR);
4542 output_constructor (exp, size, align);
4543 return;
4545 case ERROR_MARK:
4546 return;
4548 default:
4549 gcc_unreachable ();
4552 if (size > thissize)
4553 assemble_zeros (size - thissize);
4557 /* Subroutine of output_constructor, used for computing the size of
4558 arrays of unspecified length. VAL must be a CONSTRUCTOR of an array
4559 type with an unspecified upper bound. */
4561 static unsigned HOST_WIDE_INT
4562 array_size_for_constructor (tree val)
4564 tree max_index, i;
4565 unsigned HOST_WIDE_INT cnt;
4566 tree index, value, tmp;
4568 /* This code used to attempt to handle string constants that are not
4569 arrays of single-bytes, but nothing else does, so there's no point in
4570 doing it here. */
4571 if (TREE_CODE (val) == STRING_CST)
4572 return TREE_STRING_LENGTH (val);
4574 max_index = NULL_TREE;
4575 FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (val), cnt, index, value)
4577 if (TREE_CODE (index) == RANGE_EXPR)
4578 index = TREE_OPERAND (index, 1);
4579 if (max_index == NULL_TREE || tree_int_cst_lt (max_index, index))
4580 max_index = index;
4583 if (max_index == NULL_TREE)
4584 return 0;
4586 /* Compute the total number of array elements. */
4587 tmp = TYPE_MIN_VALUE (TYPE_DOMAIN (TREE_TYPE (val)));
4588 i = size_binop (MINUS_EXPR, fold_convert (sizetype, max_index),
4589 fold_convert (sizetype, tmp));
4590 i = size_binop (PLUS_EXPR, i, build_int_cst (sizetype, 1));
4592 /* Multiply by the array element unit size to find number of bytes. */
4593 i = size_binop (MULT_EXPR, i, TYPE_SIZE_UNIT (TREE_TYPE (TREE_TYPE (val))));
4595 return tree_low_cst (i, 1);
4598 /* Subroutine of output_constant, used for CONSTRUCTORs (aggregate constants).
4599 Generate at least SIZE bytes, padding if necessary. */
4601 static void
4602 output_constructor (tree exp, unsigned HOST_WIDE_INT size,
4603 unsigned int align)
4605 tree type = TREE_TYPE (exp);
4606 tree field = 0;
4607 tree min_index = 0;
4608 /* Number of bytes output or skipped so far.
4609 In other words, current position within the constructor. */
4610 HOST_WIDE_INT total_bytes = 0;
4611 /* Nonzero means BYTE contains part of a byte, to be output. */
4612 int byte_buffer_in_use = 0;
4613 int byte = 0;
4614 unsigned HOST_WIDE_INT cnt;
4615 constructor_elt *ce;
4617 gcc_assert (HOST_BITS_PER_WIDE_INT >= BITS_PER_UNIT);
4619 if (TREE_CODE (type) == RECORD_TYPE)
4620 field = TYPE_FIELDS (type);
4622 if (TREE_CODE (type) == ARRAY_TYPE
4623 && TYPE_DOMAIN (type) != 0)
4624 min_index = TYPE_MIN_VALUE (TYPE_DOMAIN (type));
4626 /* As LINK goes through the elements of the constant,
4627 FIELD goes through the structure fields, if the constant is a structure.
4628 if the constant is a union, then we override this,
4629 by getting the field from the TREE_LIST element.
4630 But the constant could also be an array. Then FIELD is zero.
4632 There is always a maximum of one element in the chain LINK for unions
4633 (even if the initializer in a source program incorrectly contains
4634 more one). */
4635 for (cnt = 0;
4636 VEC_iterate (constructor_elt, CONSTRUCTOR_ELTS (exp), cnt, ce);
4637 cnt++, field = field ? TREE_CHAIN (field) : 0)
4639 tree val = ce->value;
4640 tree index = 0;
4642 /* The element in a union constructor specifies the proper field
4643 or index. */
4644 if ((TREE_CODE (type) == RECORD_TYPE || TREE_CODE (type) == UNION_TYPE
4645 || TREE_CODE (type) == QUAL_UNION_TYPE)
4646 && ce->index != 0)
4647 field = ce->index;
4649 else if (TREE_CODE (type) == ARRAY_TYPE)
4650 index = ce->index;
4652 #ifdef ASM_COMMENT_START
4653 if (field && flag_verbose_asm)
4654 fprintf (asm_out_file, "%s %s:\n",
4655 ASM_COMMENT_START,
4656 DECL_NAME (field)
4657 ? IDENTIFIER_POINTER (DECL_NAME (field))
4658 : "<anonymous>");
4659 #endif
4661 /* Eliminate the marker that makes a cast not be an lvalue. */
4662 if (val != 0)
4663 STRIP_NOPS (val);
4665 if (index && TREE_CODE (index) == RANGE_EXPR)
4667 unsigned HOST_WIDE_INT fieldsize
4668 = int_size_in_bytes (TREE_TYPE (type));
4669 HOST_WIDE_INT lo_index = tree_low_cst (TREE_OPERAND (index, 0), 0);
4670 HOST_WIDE_INT hi_index = tree_low_cst (TREE_OPERAND (index, 1), 0);
4671 HOST_WIDE_INT index;
4672 unsigned int align2 = min_align (align, fieldsize * BITS_PER_UNIT);
4674 for (index = lo_index; index <= hi_index; index++)
4676 /* Output the element's initial value. */
4677 if (val == 0)
4678 assemble_zeros (fieldsize);
4679 else
4680 output_constant (val, fieldsize, align2);
4682 /* Count its size. */
4683 total_bytes += fieldsize;
4686 else if (field == 0 || !DECL_BIT_FIELD (field))
4688 /* An element that is not a bit-field. */
4690 unsigned HOST_WIDE_INT fieldsize;
4691 /* Since this structure is static,
4692 we know the positions are constant. */
4693 HOST_WIDE_INT pos = field ? int_byte_position (field) : 0;
4694 unsigned int align2;
4696 if (index != 0)
4697 pos = (tree_low_cst (TYPE_SIZE_UNIT (TREE_TYPE (val)), 1)
4698 * (tree_low_cst (index, 0) - tree_low_cst (min_index, 0)));
4700 /* Output any buffered-up bit-fields preceding this element. */
4701 if (byte_buffer_in_use)
4703 assemble_integer (GEN_INT (byte), 1, BITS_PER_UNIT, 1);
4704 total_bytes++;
4705 byte_buffer_in_use = 0;
4708 /* Advance to offset of this element.
4709 Note no alignment needed in an array, since that is guaranteed
4710 if each element has the proper size. */
4711 if ((field != 0 || index != 0) && pos != total_bytes)
4713 gcc_assert (pos >= total_bytes);
4714 assemble_zeros (pos - total_bytes);
4715 total_bytes = pos;
4718 /* Find the alignment of this element. */
4719 align2 = min_align (align, BITS_PER_UNIT * pos);
4721 /* Determine size this element should occupy. */
4722 if (field)
4724 fieldsize = 0;
4726 /* If this is an array with an unspecified upper bound,
4727 the initializer determines the size. */
4728 /* ??? This ought to only checked if DECL_SIZE_UNIT is NULL,
4729 but we cannot do this until the deprecated support for
4730 initializing zero-length array members is removed. */
4731 if (TREE_CODE (TREE_TYPE (field)) == ARRAY_TYPE
4732 && TYPE_DOMAIN (TREE_TYPE (field))
4733 && ! TYPE_MAX_VALUE (TYPE_DOMAIN (TREE_TYPE (field))))
4735 fieldsize = array_size_for_constructor (val);
4736 /* Given a non-empty initialization, this field had
4737 better be last. */
4738 gcc_assert (!fieldsize || !TREE_CHAIN (field));
4740 else if (DECL_SIZE_UNIT (field))
4742 /* ??? This can't be right. If the decl size overflows
4743 a host integer we will silently emit no data. */
4744 if (host_integerp (DECL_SIZE_UNIT (field), 1))
4745 fieldsize = tree_low_cst (DECL_SIZE_UNIT (field), 1);
4748 else
4749 fieldsize = int_size_in_bytes (TREE_TYPE (type));
4751 /* Output the element's initial value. */
4752 if (val == 0)
4753 assemble_zeros (fieldsize);
4754 else
4755 output_constant (val, fieldsize, align2);
4757 /* Count its size. */
4758 total_bytes += fieldsize;
4760 else if (val != 0 && TREE_CODE (val) != INTEGER_CST)
4761 error ("invalid initial value for member %qs",
4762 IDENTIFIER_POINTER (DECL_NAME (field)));
4763 else
4765 /* Element that is a bit-field. */
4767 HOST_WIDE_INT next_offset = int_bit_position (field);
4768 HOST_WIDE_INT end_offset
4769 = (next_offset + tree_low_cst (DECL_SIZE (field), 1));
4771 if (val == 0)
4772 val = integer_zero_node;
4774 /* If this field does not start in this (or, next) byte,
4775 skip some bytes. */
4776 if (next_offset / BITS_PER_UNIT != total_bytes)
4778 /* Output remnant of any bit field in previous bytes. */
4779 if (byte_buffer_in_use)
4781 assemble_integer (GEN_INT (byte), 1, BITS_PER_UNIT, 1);
4782 total_bytes++;
4783 byte_buffer_in_use = 0;
4786 /* If still not at proper byte, advance to there. */
4787 if (next_offset / BITS_PER_UNIT != total_bytes)
4789 gcc_assert (next_offset / BITS_PER_UNIT >= total_bytes);
4790 assemble_zeros (next_offset / BITS_PER_UNIT - total_bytes);
4791 total_bytes = next_offset / BITS_PER_UNIT;
4795 if (! byte_buffer_in_use)
4796 byte = 0;
4798 /* We must split the element into pieces that fall within
4799 separate bytes, and combine each byte with previous or
4800 following bit-fields. */
4802 /* next_offset is the offset n fbits from the beginning of
4803 the structure to the next bit of this element to be processed.
4804 end_offset is the offset of the first bit past the end of
4805 this element. */
4806 while (next_offset < end_offset)
4808 int this_time;
4809 int shift;
4810 HOST_WIDE_INT value;
4811 HOST_WIDE_INT next_byte = next_offset / BITS_PER_UNIT;
4812 HOST_WIDE_INT next_bit = next_offset % BITS_PER_UNIT;
4814 /* Advance from byte to byte
4815 within this element when necessary. */
4816 while (next_byte != total_bytes)
4818 assemble_integer (GEN_INT (byte), 1, BITS_PER_UNIT, 1);
4819 total_bytes++;
4820 byte = 0;
4823 /* Number of bits we can process at once
4824 (all part of the same byte). */
4825 this_time = MIN (end_offset - next_offset,
4826 BITS_PER_UNIT - next_bit);
4827 if (BYTES_BIG_ENDIAN)
4829 /* On big-endian machine, take the most significant bits
4830 first (of the bits that are significant)
4831 and put them into bytes from the most significant end. */
4832 shift = end_offset - next_offset - this_time;
4834 /* Don't try to take a bunch of bits that cross
4835 the word boundary in the INTEGER_CST. We can
4836 only select bits from the LOW or HIGH part
4837 not from both. */
4838 if (shift < HOST_BITS_PER_WIDE_INT
4839 && shift + this_time > HOST_BITS_PER_WIDE_INT)
4841 this_time = shift + this_time - HOST_BITS_PER_WIDE_INT;
4842 shift = HOST_BITS_PER_WIDE_INT;
4845 /* Now get the bits from the appropriate constant word. */
4846 if (shift < HOST_BITS_PER_WIDE_INT)
4847 value = TREE_INT_CST_LOW (val);
4848 else
4850 gcc_assert (shift < 2 * HOST_BITS_PER_WIDE_INT);
4851 value = TREE_INT_CST_HIGH (val);
4852 shift -= HOST_BITS_PER_WIDE_INT;
4855 /* Get the result. This works only when:
4856 1 <= this_time <= HOST_BITS_PER_WIDE_INT. */
4857 byte |= (((value >> shift)
4858 & (((HOST_WIDE_INT) 2 << (this_time - 1)) - 1))
4859 << (BITS_PER_UNIT - this_time - next_bit));
4861 else
4863 /* On little-endian machines,
4864 take first the least significant bits of the value
4865 and pack them starting at the least significant
4866 bits of the bytes. */
4867 shift = next_offset - int_bit_position (field);
4869 /* Don't try to take a bunch of bits that cross
4870 the word boundary in the INTEGER_CST. We can
4871 only select bits from the LOW or HIGH part
4872 not from both. */
4873 if (shift < HOST_BITS_PER_WIDE_INT
4874 && shift + this_time > HOST_BITS_PER_WIDE_INT)
4875 this_time = (HOST_BITS_PER_WIDE_INT - shift);
4877 /* Now get the bits from the appropriate constant word. */
4878 if (shift < HOST_BITS_PER_WIDE_INT)
4879 value = TREE_INT_CST_LOW (val);
4880 else
4882 gcc_assert (shift < 2 * HOST_BITS_PER_WIDE_INT);
4883 value = TREE_INT_CST_HIGH (val);
4884 shift -= HOST_BITS_PER_WIDE_INT;
4887 /* Get the result. This works only when:
4888 1 <= this_time <= HOST_BITS_PER_WIDE_INT. */
4889 byte |= (((value >> shift)
4890 & (((HOST_WIDE_INT) 2 << (this_time - 1)) - 1))
4891 << next_bit);
4894 next_offset += this_time;
4895 byte_buffer_in_use = 1;
4900 if (byte_buffer_in_use)
4902 assemble_integer (GEN_INT (byte), 1, BITS_PER_UNIT, 1);
4903 total_bytes++;
4906 if ((unsigned HOST_WIDE_INT)total_bytes < size)
4907 assemble_zeros (size - total_bytes);
4910 /* Mark DECL as weak. */
4912 static void
4913 mark_weak (tree decl)
4915 DECL_WEAK (decl) = 1;
4917 if (DECL_RTL_SET_P (decl)
4918 && MEM_P (DECL_RTL (decl))
4919 && XEXP (DECL_RTL (decl), 0)
4920 && GET_CODE (XEXP (DECL_RTL (decl), 0)) == SYMBOL_REF)
4921 SYMBOL_REF_WEAK (XEXP (DECL_RTL (decl), 0)) = 1;
4924 /* Merge weak status between NEWDECL and OLDDECL. */
4926 void
4927 merge_weak (tree newdecl, tree olddecl)
4929 if (DECL_WEAK (newdecl) == DECL_WEAK (olddecl))
4931 if (DECL_WEAK (newdecl) && SUPPORTS_WEAK)
4933 tree *pwd;
4934 /* We put the NEWDECL on the weak_decls list at some point
4935 and OLDDECL as well. Keep just OLDDECL on the list. */
4936 for (pwd = &weak_decls; *pwd; pwd = &TREE_CHAIN (*pwd))
4937 if (TREE_VALUE (*pwd) == newdecl)
4939 *pwd = TREE_CHAIN (*pwd);
4940 break;
4943 return;
4946 if (DECL_WEAK (newdecl))
4948 tree wd;
4950 /* NEWDECL is weak, but OLDDECL is not. */
4952 /* If we already output the OLDDECL, we're in trouble; we can't
4953 go back and make it weak. This error cannot be caught in
4954 declare_weak because the NEWDECL and OLDDECL was not yet
4955 been merged; therefore, TREE_ASM_WRITTEN was not set. */
4956 if (TREE_ASM_WRITTEN (olddecl))
4957 error ("weak declaration of %q+D must precede definition",
4958 newdecl);
4960 /* If we've already generated rtl referencing OLDDECL, we may
4961 have done so in a way that will not function properly with
4962 a weak symbol. */
4963 else if (TREE_USED (olddecl)
4964 && TREE_SYMBOL_REFERENCED (DECL_ASSEMBLER_NAME (olddecl)))
4965 warning (0, "weak declaration of %q+D after first use results "
4966 "in unspecified behavior", newdecl);
4968 if (SUPPORTS_WEAK)
4970 /* We put the NEWDECL on the weak_decls list at some point.
4971 Replace it with the OLDDECL. */
4972 for (wd = weak_decls; wd; wd = TREE_CHAIN (wd))
4973 if (TREE_VALUE (wd) == newdecl)
4975 TREE_VALUE (wd) = olddecl;
4976 break;
4978 /* We may not find the entry on the list. If NEWDECL is a
4979 weak alias, then we will have already called
4980 globalize_decl to remove the entry; in that case, we do
4981 not need to do anything. */
4984 /* Make the OLDDECL weak; it's OLDDECL that we'll be keeping. */
4985 mark_weak (olddecl);
4987 else
4988 /* OLDDECL was weak, but NEWDECL was not explicitly marked as
4989 weak. Just update NEWDECL to indicate that it's weak too. */
4990 mark_weak (newdecl);
4993 /* Declare DECL to be a weak symbol. */
4995 void
4996 declare_weak (tree decl)
4998 if (! TREE_PUBLIC (decl))
4999 error ("weak declaration of %q+D must be public", decl);
5000 else if (TREE_CODE (decl) == FUNCTION_DECL && TREE_ASM_WRITTEN (decl))
5001 error ("weak declaration of %q+D must precede definition", decl);
5002 else if (!SUPPORTS_WEAK)
5003 warning (0, "weak declaration of %q+D not supported", decl);
5005 mark_weak (decl);
5008 static void
5009 weak_finish_1 (tree decl)
5011 #if defined (ASM_WEAKEN_DECL) || defined (ASM_WEAKEN_LABEL)
5012 const char *const name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
5013 #endif
5015 if (! TREE_USED (decl))
5016 return;
5018 #ifdef ASM_WEAKEN_DECL
5019 ASM_WEAKEN_DECL (asm_out_file, decl, name, NULL);
5020 #else
5021 #ifdef ASM_WEAKEN_LABEL
5022 ASM_WEAKEN_LABEL (asm_out_file, name);
5023 #else
5024 #ifdef ASM_OUTPUT_WEAK_ALIAS
5026 static bool warn_once = 0;
5027 if (! warn_once)
5029 warning (0, "only weak aliases are supported in this configuration");
5030 warn_once = 1;
5032 return;
5034 #endif
5035 #endif
5036 #endif
5039 /* This TREE_LIST contains weakref targets. */
5041 static GTY(()) tree weakref_targets;
5043 /* Forward declaration. */
5044 static tree find_decl_and_mark_needed (tree decl, tree target);
5046 /* Emit any pending weak declarations. */
5048 void
5049 weak_finish (void)
5051 tree t;
5053 for (t = weakref_targets; t; t = TREE_CHAIN (t))
5055 tree alias_decl = TREE_PURPOSE (t);
5056 tree target = ultimate_transparent_alias_target (&TREE_VALUE (t));
5058 if (! TREE_SYMBOL_REFERENCED (DECL_ASSEMBLER_NAME (alias_decl)))
5059 /* Remove alias_decl from the weak list, but leave entries for
5060 the target alone. */
5061 target = NULL_TREE;
5062 #ifndef ASM_OUTPUT_WEAKREF
5063 else if (! TREE_SYMBOL_REFERENCED (target))
5065 /* Use ASM_WEAKEN_LABEL only if ASM_WEAKEN_DECL is not
5066 defined, otherwise we and weak_finish_1 would use
5067 different macros. */
5068 # if defined ASM_WEAKEN_LABEL && ! defined ASM_WEAKEN_DECL
5069 ASM_WEAKEN_LABEL (asm_out_file, IDENTIFIER_POINTER (target));
5070 # else
5071 tree decl = find_decl_and_mark_needed (alias_decl, target);
5073 if (! decl)
5075 decl = build_decl (TREE_CODE (alias_decl), target,
5076 TREE_TYPE (alias_decl));
5078 DECL_EXTERNAL (decl) = 1;
5079 TREE_PUBLIC (decl) = 1;
5080 DECL_ARTIFICIAL (decl) = 1;
5081 TREE_NOTHROW (decl) = TREE_NOTHROW (alias_decl);
5082 TREE_USED (decl) = 1;
5085 weak_finish_1 (decl);
5086 # endif
5088 #endif
5091 tree *p;
5092 tree t2;
5094 /* Remove the alias and the target from the pending weak list
5095 so that we do not emit any .weak directives for the former,
5096 nor multiple .weak directives for the latter. */
5097 for (p = &weak_decls; (t2 = *p) ; )
5099 if (TREE_VALUE (t2) == alias_decl
5100 || target == DECL_ASSEMBLER_NAME (TREE_VALUE (t2)))
5101 *p = TREE_CHAIN (t2);
5102 else
5103 p = &TREE_CHAIN (t2);
5106 /* Remove other weakrefs to the same target, to speed things up. */
5107 for (p = &TREE_CHAIN (t); (t2 = *p) ; )
5109 if (target == ultimate_transparent_alias_target (&TREE_VALUE (t2)))
5110 *p = TREE_CHAIN (t2);
5111 else
5112 p = &TREE_CHAIN (t2);
5117 for (t = weak_decls; t; t = TREE_CHAIN (t))
5119 tree decl = TREE_VALUE (t);
5121 weak_finish_1 (decl);
5125 /* Emit the assembly bits to indicate that DECL is globally visible. */
5127 static void
5128 globalize_decl (tree decl)
5131 #if defined (ASM_WEAKEN_LABEL) || defined (ASM_WEAKEN_DECL)
5132 if (DECL_WEAK (decl))
5134 const char *name = XSTR (XEXP (DECL_RTL (decl), 0), 0);
5135 tree *p, t;
5137 #ifdef ASM_WEAKEN_DECL
5138 ASM_WEAKEN_DECL (asm_out_file, decl, name, 0);
5139 #else
5140 ASM_WEAKEN_LABEL (asm_out_file, name);
5141 #endif
5143 /* Remove this function from the pending weak list so that
5144 we do not emit multiple .weak directives for it. */
5145 for (p = &weak_decls; (t = *p) ; )
5147 if (DECL_ASSEMBLER_NAME (decl) == DECL_ASSEMBLER_NAME (TREE_VALUE (t)))
5148 *p = TREE_CHAIN (t);
5149 else
5150 p = &TREE_CHAIN (t);
5153 /* Remove weakrefs to the same target from the pending weakref
5154 list, for the same reason. */
5155 for (p = &weakref_targets; (t = *p) ; )
5157 if (DECL_ASSEMBLER_NAME (decl)
5158 == ultimate_transparent_alias_target (&TREE_VALUE (t)))
5159 *p = TREE_CHAIN (t);
5160 else
5161 p = &TREE_CHAIN (t);
5164 return;
5166 #endif
5168 targetm.asm_out.globalize_decl_name (asm_out_file, decl);
5171 /* We have to be able to tell cgraph about the needed-ness of the target
5172 of an alias. This requires that the decl have been defined. Aliases
5173 that precede their definition have to be queued for later processing. */
5175 typedef struct alias_pair GTY(())
5177 tree decl;
5178 tree target;
5179 } alias_pair;
5181 /* Define gc'd vector type. */
5182 DEF_VEC_O(alias_pair);
5183 DEF_VEC_ALLOC_O(alias_pair,gc);
5185 static GTY(()) VEC(alias_pair,gc) *alias_pairs;
5187 /* Given an assembly name, find the decl it is associated with. At the
5188 same time, mark it needed for cgraph. */
5190 static tree
5191 find_decl_and_mark_needed (tree decl, tree target)
5193 struct cgraph_node *fnode = NULL;
5194 struct varpool_node *vnode = NULL;
5196 if (TREE_CODE (decl) == FUNCTION_DECL)
5198 fnode = cgraph_node_for_asm (target);
5199 if (fnode == NULL)
5200 vnode = varpool_node_for_asm (target);
5202 else
5204 vnode = varpool_node_for_asm (target);
5205 if (vnode == NULL)
5206 fnode = cgraph_node_for_asm (target);
5209 if (fnode)
5211 /* We can't mark function nodes as used after cgraph global info
5212 is finished. This wouldn't generally be necessary, but C++
5213 virtual table thunks are introduced late in the game and
5214 might seem like they need marking, although in fact they
5215 don't. */
5216 if (! cgraph_global_info_ready)
5217 cgraph_mark_needed_node (fnode);
5218 return fnode->decl;
5220 else if (vnode)
5222 varpool_mark_needed_node (vnode);
5223 return vnode->decl;
5225 else
5226 return NULL_TREE;
5229 /* Output the assembler code for a define (equate) using ASM_OUTPUT_DEF
5230 or ASM_OUTPUT_DEF_FROM_DECLS. The function defines the symbol whose
5231 tree node is DECL to have the value of the tree node TARGET. */
5233 static void
5234 do_assemble_alias (tree decl, tree target)
5236 if (TREE_ASM_WRITTEN (decl))
5237 return;
5239 TREE_ASM_WRITTEN (decl) = 1;
5240 TREE_ASM_WRITTEN (DECL_ASSEMBLER_NAME (decl)) = 1;
5242 if (lookup_attribute ("weakref", DECL_ATTRIBUTES (decl)))
5244 ultimate_transparent_alias_target (&target);
5246 if (!targetm.have_tls
5247 && TREE_CODE (decl) == VAR_DECL
5248 && DECL_THREAD_LOCAL_P (decl))
5250 decl = emutls_decl (decl);
5251 target = get_emutls_object_name (target);
5254 if (!TREE_SYMBOL_REFERENCED (target))
5255 weakref_targets = tree_cons (decl, target, weakref_targets);
5257 #ifdef ASM_OUTPUT_WEAKREF
5258 ASM_OUTPUT_WEAKREF (asm_out_file, decl,
5259 IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl)),
5260 IDENTIFIER_POINTER (target));
5261 #else
5262 if (!SUPPORTS_WEAK)
5264 error ("%Jweakref is not supported in this configuration", decl);
5265 return;
5267 #endif
5268 return;
5271 if (!targetm.have_tls
5272 && TREE_CODE (decl) == VAR_DECL
5273 && DECL_THREAD_LOCAL_P (decl))
5275 decl = emutls_decl (decl);
5276 target = get_emutls_object_name (target);
5279 #ifdef ASM_OUTPUT_DEF
5280 /* Make name accessible from other files, if appropriate. */
5282 if (TREE_PUBLIC (decl))
5284 globalize_decl (decl);
5285 maybe_assemble_visibility (decl);
5288 # ifdef ASM_OUTPUT_DEF_FROM_DECLS
5289 ASM_OUTPUT_DEF_FROM_DECLS (asm_out_file, decl, target);
5290 # else
5291 ASM_OUTPUT_DEF (asm_out_file,
5292 IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl)),
5293 IDENTIFIER_POINTER (target));
5294 # endif
5295 #elif defined (ASM_OUTPUT_WEAK_ALIAS) || defined (ASM_WEAKEN_DECL)
5297 const char *name;
5298 tree *p, t;
5300 name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
5301 # ifdef ASM_WEAKEN_DECL
5302 ASM_WEAKEN_DECL (asm_out_file, decl, name, IDENTIFIER_POINTER (target));
5303 # else
5304 ASM_OUTPUT_WEAK_ALIAS (asm_out_file, name, IDENTIFIER_POINTER (target));
5305 # endif
5306 /* Remove this function from the pending weak list so that
5307 we do not emit multiple .weak directives for it. */
5308 for (p = &weak_decls; (t = *p) ; )
5309 if (DECL_ASSEMBLER_NAME (decl) == DECL_ASSEMBLER_NAME (TREE_VALUE (t)))
5310 *p = TREE_CHAIN (t);
5311 else
5312 p = &TREE_CHAIN (t);
5314 /* Remove weakrefs to the same target from the pending weakref
5315 list, for the same reason. */
5316 for (p = &weakref_targets; (t = *p) ; )
5318 if (DECL_ASSEMBLER_NAME (decl)
5319 == ultimate_transparent_alias_target (&TREE_VALUE (t)))
5320 *p = TREE_CHAIN (t);
5321 else
5322 p = &TREE_CHAIN (t);
5325 #endif
5328 /* First pass of completing pending aliases. Make sure that cgraph knows
5329 which symbols will be required. */
5331 void
5332 finish_aliases_1 (void)
5334 unsigned i;
5335 alias_pair *p;
5337 for (i = 0; VEC_iterate (alias_pair, alias_pairs, i, p); i++)
5339 tree target_decl;
5341 target_decl = find_decl_and_mark_needed (p->decl, p->target);
5342 if (target_decl == NULL)
5344 if (! lookup_attribute ("weakref", DECL_ATTRIBUTES (p->decl)))
5345 error ("%q+D aliased to undefined symbol %qs",
5346 p->decl, IDENTIFIER_POINTER (p->target));
5348 else if (DECL_EXTERNAL (target_decl)
5349 && ! lookup_attribute ("weakref", DECL_ATTRIBUTES (p->decl)))
5350 error ("%q+D aliased to external symbol %qs",
5351 p->decl, IDENTIFIER_POINTER (p->target));
5355 /* Second pass of completing pending aliases. Emit the actual assembly.
5356 This happens at the end of compilation and thus it is assured that the
5357 target symbol has been emitted. */
5359 void
5360 finish_aliases_2 (void)
5362 unsigned i;
5363 alias_pair *p;
5365 for (i = 0; VEC_iterate (alias_pair, alias_pairs, i, p); i++)
5366 do_assemble_alias (p->decl, p->target);
5368 VEC_truncate (alias_pair, alias_pairs, 0);
5371 /* Emit an assembler directive to make the symbol for DECL an alias to
5372 the symbol for TARGET. */
5374 void
5375 assemble_alias (tree decl, tree target)
5377 tree target_decl;
5378 bool is_weakref = false;
5380 if (lookup_attribute ("weakref", DECL_ATTRIBUTES (decl)))
5382 tree alias = DECL_ASSEMBLER_NAME (decl);
5384 is_weakref = true;
5386 ultimate_transparent_alias_target (&target);
5388 if (alias == target)
5389 error ("weakref %q+D ultimately targets itself", decl);
5390 else
5392 #ifndef ASM_OUTPUT_WEAKREF
5393 IDENTIFIER_TRANSPARENT_ALIAS (alias) = 1;
5394 TREE_CHAIN (alias) = target;
5395 #endif
5397 if (TREE_PUBLIC (decl))
5398 error ("weakref %q+D must have static linkage", decl);
5400 else
5402 #if !defined (ASM_OUTPUT_DEF)
5403 # if !defined(ASM_OUTPUT_WEAK_ALIAS) && !defined (ASM_WEAKEN_DECL)
5404 error ("%Jalias definitions not supported in this configuration", decl);
5405 return;
5406 # else
5407 if (!DECL_WEAK (decl))
5409 error ("%Jonly weak aliases are supported in this configuration", decl);
5410 return;
5412 # endif
5413 #endif
5416 /* We must force creation of DECL_RTL for debug info generation, even though
5417 we don't use it here. */
5418 make_decl_rtl (decl);
5419 TREE_USED (decl) = 1;
5421 /* A quirk of the initial implementation of aliases required that the user
5422 add "extern" to all of them. Which is silly, but now historical. Do
5423 note that the symbol is in fact locally defined. */
5424 if (! is_weakref)
5425 DECL_EXTERNAL (decl) = 0;
5427 /* Allow aliases to aliases. */
5428 if (TREE_CODE (decl) == FUNCTION_DECL)
5429 cgraph_node (decl)->alias = true;
5430 else
5431 varpool_node (decl)->alias = true;
5433 /* If the target has already been emitted, we don't have to queue the
5434 alias. This saves a tad of memory. */
5435 if (cgraph_global_info_ready)
5436 target_decl = find_decl_and_mark_needed (decl, target);
5437 else
5438 target_decl= NULL;
5439 if (target_decl && TREE_ASM_WRITTEN (target_decl))
5440 do_assemble_alias (decl, target);
5441 else
5443 alias_pair *p = VEC_safe_push (alias_pair, gc, alias_pairs, NULL);
5444 p->decl = decl;
5445 p->target = target;
5449 /* Emit an assembler directive to set symbol for DECL visibility to
5450 the visibility type VIS, which must not be VISIBILITY_DEFAULT. */
5452 void
5453 default_assemble_visibility (tree decl, int vis)
5455 static const char * const visibility_types[] = {
5456 NULL, "protected", "hidden", "internal"
5459 const char *name, *type;
5461 name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
5462 type = visibility_types[vis];
5464 #ifdef HAVE_GAS_HIDDEN
5465 fprintf (asm_out_file, "\t.%s\t", type);
5466 assemble_name (asm_out_file, name);
5467 fprintf (asm_out_file, "\n");
5468 #else
5469 warning (OPT_Wattributes, "visibility attribute not supported "
5470 "in this configuration; ignored");
5471 #endif
5474 /* A helper function to call assemble_visibility when needed for a decl. */
5477 maybe_assemble_visibility (tree decl)
5479 enum symbol_visibility vis = DECL_VISIBILITY (decl);
5481 if (vis != VISIBILITY_DEFAULT)
5483 targetm.asm_out.visibility (decl, vis);
5484 return 1;
5486 else
5487 return 0;
5490 /* Returns 1 if the target configuration supports defining public symbols
5491 so that one of them will be chosen at link time instead of generating a
5492 multiply-defined symbol error, whether through the use of weak symbols or
5493 a target-specific mechanism for having duplicates discarded. */
5496 supports_one_only (void)
5498 if (SUPPORTS_ONE_ONLY)
5499 return 1;
5500 return SUPPORTS_WEAK;
5503 /* Set up DECL as a public symbol that can be defined in multiple
5504 translation units without generating a linker error. */
5506 void
5507 make_decl_one_only (tree decl)
5509 gcc_assert (TREE_CODE (decl) == VAR_DECL
5510 || TREE_CODE (decl) == FUNCTION_DECL);
5512 TREE_PUBLIC (decl) = 1;
5514 if (SUPPORTS_ONE_ONLY)
5516 #ifdef MAKE_DECL_ONE_ONLY
5517 MAKE_DECL_ONE_ONLY (decl);
5518 #endif
5519 DECL_ONE_ONLY (decl) = 1;
5521 else if (TREE_CODE (decl) == VAR_DECL
5522 && (DECL_INITIAL (decl) == 0 || DECL_INITIAL (decl) == error_mark_node))
5523 DECL_COMMON (decl) = 1;
5524 else
5526 gcc_assert (SUPPORTS_WEAK);
5527 DECL_WEAK (decl) = 1;
5531 void
5532 init_varasm_once (void)
5534 section_htab = htab_create_ggc (31, section_entry_hash,
5535 section_entry_eq, NULL);
5536 object_block_htab = htab_create_ggc (31, object_block_entry_hash,
5537 object_block_entry_eq, NULL);
5538 const_desc_htab = htab_create_ggc (1009, const_desc_hash,
5539 const_desc_eq, NULL);
5541 const_alias_set = new_alias_set ();
5542 shared_constant_pool = create_constant_pool ();
5544 #ifdef TEXT_SECTION_ASM_OP
5545 text_section = get_unnamed_section (SECTION_CODE, output_section_asm_op,
5546 TEXT_SECTION_ASM_OP);
5547 #endif
5549 #ifdef DATA_SECTION_ASM_OP
5550 data_section = get_unnamed_section (SECTION_WRITE, output_section_asm_op,
5551 DATA_SECTION_ASM_OP);
5552 #endif
5554 #ifdef SDATA_SECTION_ASM_OP
5555 sdata_section = get_unnamed_section (SECTION_WRITE, output_section_asm_op,
5556 SDATA_SECTION_ASM_OP);
5557 #endif
5559 #ifdef READONLY_DATA_SECTION_ASM_OP
5560 readonly_data_section = get_unnamed_section (0, output_section_asm_op,
5561 READONLY_DATA_SECTION_ASM_OP);
5562 #endif
5564 #ifdef CTORS_SECTION_ASM_OP
5565 ctors_section = get_unnamed_section (0, output_section_asm_op,
5566 CTORS_SECTION_ASM_OP);
5567 #endif
5569 #ifdef DTORS_SECTION_ASM_OP
5570 dtors_section = get_unnamed_section (0, output_section_asm_op,
5571 DTORS_SECTION_ASM_OP);
5572 #endif
5574 #ifdef BSS_SECTION_ASM_OP
5575 bss_section = get_unnamed_section (SECTION_WRITE | SECTION_BSS,
5576 output_section_asm_op,
5577 BSS_SECTION_ASM_OP);
5578 #endif
5580 #ifdef SBSS_SECTION_ASM_OP
5581 sbss_section = get_unnamed_section (SECTION_WRITE | SECTION_BSS,
5582 output_section_asm_op,
5583 SBSS_SECTION_ASM_OP);
5584 #endif
5586 tls_comm_section = get_noswitch_section (SECTION_WRITE | SECTION_BSS
5587 | SECTION_COMMON, emit_tls_common);
5588 lcomm_section = get_noswitch_section (SECTION_WRITE | SECTION_BSS
5589 | SECTION_COMMON, emit_local);
5590 comm_section = get_noswitch_section (SECTION_WRITE | SECTION_BSS
5591 | SECTION_COMMON, emit_common);
5593 #if defined ASM_OUTPUT_ALIGNED_BSS || defined ASM_OUTPUT_BSS
5594 bss_noswitch_section = get_noswitch_section (SECTION_WRITE | SECTION_BSS,
5595 emit_bss);
5596 #endif
5598 targetm.asm_out.init_sections ();
5600 if (readonly_data_section == NULL)
5601 readonly_data_section = text_section;
5604 enum tls_model
5605 decl_default_tls_model (const_tree decl)
5607 enum tls_model kind;
5608 bool is_local;
5610 is_local = targetm.binds_local_p (decl);
5611 if (!flag_shlib)
5613 if (is_local)
5614 kind = TLS_MODEL_LOCAL_EXEC;
5615 else
5616 kind = TLS_MODEL_INITIAL_EXEC;
5619 /* Local dynamic is inefficient when we're not combining the
5620 parts of the address. */
5621 else if (optimize && is_local)
5622 kind = TLS_MODEL_LOCAL_DYNAMIC;
5623 else
5624 kind = TLS_MODEL_GLOBAL_DYNAMIC;
5625 if (kind < flag_tls_default)
5626 kind = flag_tls_default;
5628 return kind;
5631 /* Select a set of attributes for section NAME based on the properties
5632 of DECL and whether or not RELOC indicates that DECL's initializer
5633 might contain runtime relocations.
5635 We make the section read-only and executable for a function decl,
5636 read-only for a const data decl, and writable for a non-const data decl. */
5638 unsigned int
5639 default_section_type_flags (tree decl, const char *name, int reloc)
5641 unsigned int flags;
5643 if (decl && TREE_CODE (decl) == FUNCTION_DECL)
5644 flags = SECTION_CODE;
5645 else if (decl && decl_readonly_section (decl, reloc))
5646 flags = 0;
5647 else if (current_function_decl
5648 && cfun
5649 && crtl->subsections.unlikely_text_section_name
5650 && strcmp (name, crtl->subsections.unlikely_text_section_name) == 0)
5651 flags = SECTION_CODE;
5652 else if (!decl
5653 && (!current_function_decl || !cfun)
5654 && strcmp (name, UNLIKELY_EXECUTED_TEXT_SECTION_NAME) == 0)
5655 flags = SECTION_CODE;
5656 else
5657 flags = SECTION_WRITE;
5659 if (decl && DECL_ONE_ONLY (decl))
5660 flags |= SECTION_LINKONCE;
5662 if (decl && TREE_CODE (decl) == VAR_DECL && DECL_THREAD_LOCAL_P (decl))
5663 flags |= SECTION_TLS | SECTION_WRITE;
5665 if (strcmp (name, ".bss") == 0
5666 || strncmp (name, ".bss.", 5) == 0
5667 || strncmp (name, ".gnu.linkonce.b.", 16) == 0
5668 || strcmp (name, ".sbss") == 0
5669 || strncmp (name, ".sbss.", 6) == 0
5670 || strncmp (name, ".gnu.linkonce.sb.", 17) == 0)
5671 flags |= SECTION_BSS;
5673 if (strcmp (name, ".tdata") == 0
5674 || strncmp (name, ".tdata.", 7) == 0
5675 || strncmp (name, ".gnu.linkonce.td.", 17) == 0)
5676 flags |= SECTION_TLS;
5678 if (strcmp (name, ".tbss") == 0
5679 || strncmp (name, ".tbss.", 6) == 0
5680 || strncmp (name, ".gnu.linkonce.tb.", 17) == 0)
5681 flags |= SECTION_TLS | SECTION_BSS;
5683 /* These three sections have special ELF types. They are neither
5684 SHT_PROGBITS nor SHT_NOBITS, so when changing sections we don't
5685 want to print a section type (@progbits or @nobits). If someone
5686 is silly enough to emit code or TLS variables to one of these
5687 sections, then don't handle them specially. */
5688 if (!(flags & (SECTION_CODE | SECTION_BSS | SECTION_TLS))
5689 && (strcmp (name, ".init_array") == 0
5690 || strcmp (name, ".fini_array") == 0
5691 || strcmp (name, ".preinit_array") == 0))
5692 flags |= SECTION_NOTYPE;
5694 return flags;
5697 /* Return true if the target supports some form of global BSS,
5698 either through bss_noswitch_section, or by selecting a BSS
5699 section in TARGET_ASM_SELECT_SECTION. */
5701 bool
5702 have_global_bss_p (void)
5704 return bss_noswitch_section || targetm.have_switchable_bss_sections;
5707 /* Output assembly to switch to section NAME with attribute FLAGS.
5708 Four variants for common object file formats. */
5710 void
5711 default_no_named_section (const char *name ATTRIBUTE_UNUSED,
5712 unsigned int flags ATTRIBUTE_UNUSED,
5713 tree decl ATTRIBUTE_UNUSED)
5715 /* Some object formats don't support named sections at all. The
5716 front-end should already have flagged this as an error. */
5717 gcc_unreachable ();
5720 void
5721 default_elf_asm_named_section (const char *name, unsigned int flags,
5722 tree decl ATTRIBUTE_UNUSED)
5724 char flagchars[10], *f = flagchars;
5726 /* If we have already declared this section, we can use an
5727 abbreviated form to switch back to it -- unless this section is
5728 part of a COMDAT groups, in which case GAS requires the full
5729 declaration every time. */
5730 if (!(HAVE_COMDAT_GROUP && (flags & SECTION_LINKONCE))
5731 && (flags & SECTION_DECLARED))
5733 fprintf (asm_out_file, "\t.section\t%s\n", name);
5734 return;
5737 if (!(flags & SECTION_DEBUG))
5738 *f++ = 'a';
5739 if (flags & SECTION_WRITE)
5740 *f++ = 'w';
5741 if (flags & SECTION_CODE)
5742 *f++ = 'x';
5743 if (flags & SECTION_SMALL)
5744 *f++ = 's';
5745 if (flags & SECTION_MERGE)
5746 *f++ = 'M';
5747 if (flags & SECTION_STRINGS)
5748 *f++ = 'S';
5749 if (flags & SECTION_TLS)
5750 *f++ = 'T';
5751 if (HAVE_COMDAT_GROUP && (flags & SECTION_LINKONCE))
5752 *f++ = 'G';
5753 *f = '\0';
5755 fprintf (asm_out_file, "\t.section\t%s,\"%s\"", name, flagchars);
5757 if (!(flags & SECTION_NOTYPE))
5759 const char *type;
5760 const char *format;
5762 if (flags & SECTION_BSS)
5763 type = "nobits";
5764 else
5765 type = "progbits";
5767 format = ",@%s";
5768 #ifdef ASM_COMMENT_START
5769 /* On platforms that use "@" as the assembly comment character,
5770 use "%" instead. */
5771 if (strcmp (ASM_COMMENT_START, "@") == 0)
5772 format = ",%%%s";
5773 #endif
5774 fprintf (asm_out_file, format, type);
5776 if (flags & SECTION_ENTSIZE)
5777 fprintf (asm_out_file, ",%d", flags & SECTION_ENTSIZE);
5778 if (HAVE_COMDAT_GROUP && (flags & SECTION_LINKONCE))
5779 fprintf (asm_out_file, ",%s,comdat",
5780 lang_hooks.decls.comdat_group (decl));
5783 putc ('\n', asm_out_file);
5786 void
5787 default_coff_asm_named_section (const char *name, unsigned int flags,
5788 tree decl ATTRIBUTE_UNUSED)
5790 char flagchars[8], *f = flagchars;
5792 if (flags & SECTION_WRITE)
5793 *f++ = 'w';
5794 if (flags & SECTION_CODE)
5795 *f++ = 'x';
5796 *f = '\0';
5798 fprintf (asm_out_file, "\t.section\t%s,\"%s\"\n", name, flagchars);
5801 void
5802 default_pe_asm_named_section (const char *name, unsigned int flags,
5803 tree decl)
5805 default_coff_asm_named_section (name, flags, decl);
5807 if (flags & SECTION_LINKONCE)
5809 /* Functions may have been compiled at various levels of
5810 optimization so we can't use `same_size' here.
5811 Instead, have the linker pick one. */
5812 fprintf (asm_out_file, "\t.linkonce %s\n",
5813 (flags & SECTION_CODE ? "discard" : "same_size"));
5817 /* The lame default section selector. */
5819 section *
5820 default_select_section (tree decl, int reloc,
5821 unsigned HOST_WIDE_INT align ATTRIBUTE_UNUSED)
5823 if (DECL_P (decl))
5825 if (decl_readonly_section (decl, reloc))
5826 return readonly_data_section;
5828 else if (TREE_CODE (decl) == CONSTRUCTOR)
5830 if (! ((flag_pic && reloc)
5831 || !TREE_READONLY (decl)
5832 || TREE_SIDE_EFFECTS (decl)
5833 || !TREE_CONSTANT (decl)))
5834 return readonly_data_section;
5836 else if (TREE_CODE (decl) == STRING_CST)
5837 return readonly_data_section;
5838 else if (! (flag_pic && reloc))
5839 return readonly_data_section;
5841 return data_section;
5844 enum section_category
5845 categorize_decl_for_section (const_tree decl, int reloc)
5847 enum section_category ret;
5849 if (TREE_CODE (decl) == FUNCTION_DECL)
5850 return SECCAT_TEXT;
5851 else if (TREE_CODE (decl) == STRING_CST)
5853 if (flag_mudflap) /* or !flag_merge_constants */
5854 return SECCAT_RODATA;
5855 else
5856 return SECCAT_RODATA_MERGE_STR;
5858 else if (TREE_CODE (decl) == VAR_DECL)
5860 if (bss_initializer_p (decl))
5861 ret = SECCAT_BSS;
5862 else if (! TREE_READONLY (decl)
5863 || TREE_SIDE_EFFECTS (decl)
5864 || ! TREE_CONSTANT (DECL_INITIAL (decl)))
5866 /* Here the reloc_rw_mask is not testing whether the section should
5867 be read-only or not, but whether the dynamic link will have to
5868 do something. If so, we wish to segregate the data in order to
5869 minimize cache misses inside the dynamic linker. */
5870 if (reloc & targetm.asm_out.reloc_rw_mask ())
5871 ret = reloc == 1 ? SECCAT_DATA_REL_LOCAL : SECCAT_DATA_REL;
5872 else
5873 ret = SECCAT_DATA;
5875 else if (reloc & targetm.asm_out.reloc_rw_mask ())
5876 ret = reloc == 1 ? SECCAT_DATA_REL_RO_LOCAL : SECCAT_DATA_REL_RO;
5877 else if (reloc || flag_merge_constants < 2)
5878 /* C and C++ don't allow different variables to share the same
5879 location. -fmerge-all-constants allows even that (at the
5880 expense of not conforming). */
5881 ret = SECCAT_RODATA;
5882 else if (TREE_CODE (DECL_INITIAL (decl)) == STRING_CST)
5883 ret = SECCAT_RODATA_MERGE_STR_INIT;
5884 else
5885 ret = SECCAT_RODATA_MERGE_CONST;
5887 else if (TREE_CODE (decl) == CONSTRUCTOR)
5889 if ((reloc & targetm.asm_out.reloc_rw_mask ())
5890 || TREE_SIDE_EFFECTS (decl)
5891 || ! TREE_CONSTANT (decl))
5892 ret = SECCAT_DATA;
5893 else
5894 ret = SECCAT_RODATA;
5896 else
5897 ret = SECCAT_RODATA;
5899 /* There are no read-only thread-local sections. */
5900 if (TREE_CODE (decl) == VAR_DECL && DECL_TLS_MODEL (decl))
5902 if (DECL_TLS_MODEL (decl) == TLS_MODEL_EMULATED)
5904 if (DECL_EMUTLS_VAR_P (decl))
5906 if (targetm.emutls.var_section)
5907 ret = SECCAT_EMUTLS_VAR;
5909 else
5911 if (targetm.emutls.tmpl_prefix)
5912 ret = SECCAT_EMUTLS_TMPL;
5915 /* Note that this would be *just* SECCAT_BSS, except that there's
5916 no concept of a read-only thread-local-data section. */
5917 else if (ret == SECCAT_BSS
5918 || (flag_zero_initialized_in_bss
5919 && initializer_zerop (DECL_INITIAL (decl))))
5920 ret = SECCAT_TBSS;
5921 else
5922 ret = SECCAT_TDATA;
5925 /* If the target uses small data sections, select it. */
5926 else if (targetm.in_small_data_p (decl))
5928 if (ret == SECCAT_BSS)
5929 ret = SECCAT_SBSS;
5930 else if (targetm.have_srodata_section && ret == SECCAT_RODATA)
5931 ret = SECCAT_SRODATA;
5932 else
5933 ret = SECCAT_SDATA;
5936 return ret;
5939 bool
5940 decl_readonly_section (const_tree decl, int reloc)
5942 switch (categorize_decl_for_section (decl, reloc))
5944 case SECCAT_RODATA:
5945 case SECCAT_RODATA_MERGE_STR:
5946 case SECCAT_RODATA_MERGE_STR_INIT:
5947 case SECCAT_RODATA_MERGE_CONST:
5948 case SECCAT_SRODATA:
5949 return true;
5950 break;
5951 default:
5952 return false;
5953 break;
5957 /* Select a section based on the above categorization. */
5959 section *
5960 default_elf_select_section (tree decl, int reloc,
5961 unsigned HOST_WIDE_INT align)
5963 const char *sname;
5964 switch (categorize_decl_for_section (decl, reloc))
5966 case SECCAT_TEXT:
5967 /* We're not supposed to be called on FUNCTION_DECLs. */
5968 gcc_unreachable ();
5969 case SECCAT_RODATA:
5970 return readonly_data_section;
5971 case SECCAT_RODATA_MERGE_STR:
5972 return mergeable_string_section (decl, align, 0);
5973 case SECCAT_RODATA_MERGE_STR_INIT:
5974 return mergeable_string_section (DECL_INITIAL (decl), align, 0);
5975 case SECCAT_RODATA_MERGE_CONST:
5976 return mergeable_constant_section (DECL_MODE (decl), align, 0);
5977 case SECCAT_SRODATA:
5978 sname = ".sdata2";
5979 break;
5980 case SECCAT_DATA:
5981 return data_section;
5982 case SECCAT_DATA_REL:
5983 sname = ".data.rel";
5984 break;
5985 case SECCAT_DATA_REL_LOCAL:
5986 sname = ".data.rel.local";
5987 break;
5988 case SECCAT_DATA_REL_RO:
5989 sname = ".data.rel.ro";
5990 break;
5991 case SECCAT_DATA_REL_RO_LOCAL:
5992 sname = ".data.rel.ro.local";
5993 break;
5994 case SECCAT_SDATA:
5995 sname = ".sdata";
5996 break;
5997 case SECCAT_TDATA:
5998 sname = ".tdata";
5999 break;
6000 case SECCAT_BSS:
6001 if (bss_section)
6002 return bss_section;
6003 sname = ".bss";
6004 break;
6005 case SECCAT_SBSS:
6006 sname = ".sbss";
6007 break;
6008 case SECCAT_TBSS:
6009 sname = ".tbss";
6010 break;
6011 case SECCAT_EMUTLS_VAR:
6012 sname = targetm.emutls.var_section;
6013 break;
6014 case SECCAT_EMUTLS_TMPL:
6015 sname = targetm.emutls.tmpl_section;
6016 break;
6017 default:
6018 gcc_unreachable ();
6021 if (!DECL_P (decl))
6022 decl = NULL_TREE;
6023 return get_named_section (decl, sname, reloc);
6026 /* Construct a unique section name based on the decl name and the
6027 categorization performed above. */
6029 void
6030 default_unique_section (tree decl, int reloc)
6032 /* We only need to use .gnu.linkonce if we don't have COMDAT groups. */
6033 bool one_only = DECL_ONE_ONLY (decl) && !HAVE_COMDAT_GROUP;
6034 const char *prefix, *name, *linkonce;
6035 char *string;
6037 switch (categorize_decl_for_section (decl, reloc))
6039 case SECCAT_TEXT:
6040 prefix = one_only ? ".t" : ".text";
6041 break;
6042 case SECCAT_RODATA:
6043 case SECCAT_RODATA_MERGE_STR:
6044 case SECCAT_RODATA_MERGE_STR_INIT:
6045 case SECCAT_RODATA_MERGE_CONST:
6046 prefix = one_only ? ".r" : ".rodata";
6047 break;
6048 case SECCAT_SRODATA:
6049 prefix = one_only ? ".s2" : ".sdata2";
6050 break;
6051 case SECCAT_DATA:
6052 prefix = one_only ? ".d" : ".data";
6053 break;
6054 case SECCAT_DATA_REL:
6055 prefix = one_only ? ".d.rel" : ".data.rel";
6056 break;
6057 case SECCAT_DATA_REL_LOCAL:
6058 prefix = one_only ? ".d.rel.local" : ".data.rel.local";
6059 break;
6060 case SECCAT_DATA_REL_RO:
6061 prefix = one_only ? ".d.rel.ro" : ".data.rel.ro";
6062 break;
6063 case SECCAT_DATA_REL_RO_LOCAL:
6064 prefix = one_only ? ".d.rel.ro.local" : ".data.rel.ro.local";
6065 break;
6066 case SECCAT_SDATA:
6067 prefix = one_only ? ".s" : ".sdata";
6068 break;
6069 case SECCAT_BSS:
6070 prefix = one_only ? ".b" : ".bss";
6071 break;
6072 case SECCAT_SBSS:
6073 prefix = one_only ? ".sb" : ".sbss";
6074 break;
6075 case SECCAT_TDATA:
6076 prefix = one_only ? ".td" : ".tdata";
6077 break;
6078 case SECCAT_TBSS:
6079 prefix = one_only ? ".tb" : ".tbss";
6080 break;
6081 case SECCAT_EMUTLS_VAR:
6082 prefix = targetm.emutls.var_section;
6083 break;
6084 case SECCAT_EMUTLS_TMPL:
6085 prefix = targetm.emutls.tmpl_section;
6086 break;
6087 default:
6088 gcc_unreachable ();
6091 name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
6092 name = targetm.strip_name_encoding (name);
6094 /* If we're using one_only, then there needs to be a .gnu.linkonce
6095 prefix to the section name. */
6096 linkonce = one_only ? ".gnu.linkonce" : "";
6098 string = ACONCAT ((linkonce, prefix, ".", name, NULL));
6100 DECL_SECTION_NAME (decl) = build_string (strlen (string), string);
6103 /* Like compute_reloc_for_constant, except for an RTX. The return value
6104 is a mask for which bit 1 indicates a global relocation, and bit 0
6105 indicates a local relocation. */
6107 static int
6108 compute_reloc_for_rtx_1 (rtx *xp, void *data)
6110 int *preloc = (int *) data;
6111 rtx x = *xp;
6113 switch (GET_CODE (x))
6115 case SYMBOL_REF:
6116 *preloc |= SYMBOL_REF_LOCAL_P (x) ? 1 : 2;
6117 break;
6118 case LABEL_REF:
6119 *preloc |= 1;
6120 break;
6121 default:
6122 break;
6125 return 0;
6128 static int
6129 compute_reloc_for_rtx (rtx x)
6131 int reloc;
6133 switch (GET_CODE (x))
6135 case CONST:
6136 case SYMBOL_REF:
6137 case LABEL_REF:
6138 reloc = 0;
6139 for_each_rtx (&x, compute_reloc_for_rtx_1, &reloc);
6140 return reloc;
6142 default:
6143 return 0;
6147 section *
6148 default_select_rtx_section (enum machine_mode mode ATTRIBUTE_UNUSED,
6149 rtx x,
6150 unsigned HOST_WIDE_INT align ATTRIBUTE_UNUSED)
6152 if (compute_reloc_for_rtx (x) & targetm.asm_out.reloc_rw_mask ())
6153 return data_section;
6154 else
6155 return readonly_data_section;
6158 section *
6159 default_elf_select_rtx_section (enum machine_mode mode, rtx x,
6160 unsigned HOST_WIDE_INT align)
6162 int reloc = compute_reloc_for_rtx (x);
6164 /* ??? Handle small data here somehow. */
6166 if (reloc & targetm.asm_out.reloc_rw_mask ())
6168 if (reloc == 1)
6169 return get_named_section (NULL, ".data.rel.ro.local", 1);
6170 else
6171 return get_named_section (NULL, ".data.rel.ro", 3);
6174 return mergeable_constant_section (mode, align, 0);
6177 /* Set the generally applicable flags on the SYMBOL_REF for EXP. */
6179 void
6180 default_encode_section_info (tree decl, rtx rtl, int first ATTRIBUTE_UNUSED)
6182 rtx symbol;
6183 int flags;
6185 /* Careful not to prod global register variables. */
6186 if (!MEM_P (rtl))
6187 return;
6188 symbol = XEXP (rtl, 0);
6189 if (GET_CODE (symbol) != SYMBOL_REF)
6190 return;
6192 flags = SYMBOL_REF_FLAGS (symbol) & SYMBOL_FLAG_HAS_BLOCK_INFO;
6193 if (TREE_CODE (decl) == FUNCTION_DECL)
6194 flags |= SYMBOL_FLAG_FUNCTION;
6195 if (targetm.binds_local_p (decl))
6196 flags |= SYMBOL_FLAG_LOCAL;
6197 if (targetm.have_tls && TREE_CODE (decl) == VAR_DECL
6198 && DECL_THREAD_LOCAL_P (decl))
6199 flags |= DECL_TLS_MODEL (decl) << SYMBOL_FLAG_TLS_SHIFT;
6200 else if (targetm.in_small_data_p (decl))
6201 flags |= SYMBOL_FLAG_SMALL;
6202 /* ??? Why is DECL_EXTERNAL ever set for non-PUBLIC names? Without
6203 being PUBLIC, the thing *must* be defined in this translation unit.
6204 Prevent this buglet from being propagated into rtl code as well. */
6205 if (DECL_P (decl) && DECL_EXTERNAL (decl) && TREE_PUBLIC (decl))
6206 flags |= SYMBOL_FLAG_EXTERNAL;
6208 SYMBOL_REF_FLAGS (symbol) = flags;
6211 /* By default, we do nothing for encode_section_info, so we need not
6212 do anything but discard the '*' marker. */
6214 const char *
6215 default_strip_name_encoding (const char *str)
6217 return str + (*str == '*');
6220 #ifdef ASM_OUTPUT_DEF
6221 /* The default implementation of TARGET_ASM_OUTPUT_ANCHOR. Define the
6222 anchor relative to ".", the current section position. */
6224 void
6225 default_asm_output_anchor (rtx symbol)
6227 char buffer[100];
6229 sprintf (buffer, "*. + " HOST_WIDE_INT_PRINT_DEC,
6230 SYMBOL_REF_BLOCK_OFFSET (symbol));
6231 ASM_OUTPUT_DEF (asm_out_file, XSTR (symbol, 0), buffer);
6233 #endif
6235 /* The default implementation of TARGET_USE_ANCHORS_FOR_SYMBOL_P. */
6237 bool
6238 default_use_anchors_for_symbol_p (const_rtx symbol)
6240 section *sect;
6241 tree decl;
6243 /* Don't use anchors for mergeable sections. The linker might move
6244 the objects around. */
6245 sect = SYMBOL_REF_BLOCK (symbol)->sect;
6246 if (sect->common.flags & SECTION_MERGE)
6247 return false;
6249 /* Don't use anchors for small data sections. The small data register
6250 acts as an anchor for such sections. */
6251 if (sect->common.flags & SECTION_SMALL)
6252 return false;
6254 decl = SYMBOL_REF_DECL (symbol);
6255 if (decl && DECL_P (decl))
6257 /* Don't use section anchors for decls that might be defined by
6258 other modules. */
6259 if (!targetm.binds_local_p (decl))
6260 return false;
6262 /* Don't use section anchors for decls that will be placed in a
6263 small data section. */
6264 /* ??? Ideally, this check would be redundant with the SECTION_SMALL
6265 one above. The problem is that we only use SECTION_SMALL for
6266 sections that should be marked as small in the section directive. */
6267 if (targetm.in_small_data_p (decl))
6268 return false;
6270 return true;
6273 /* Assume ELF-ish defaults, since that's pretty much the most liberal
6274 wrt cross-module name binding. */
6276 bool
6277 default_binds_local_p (const_tree exp)
6279 return default_binds_local_p_1 (exp, flag_shlib);
6282 bool
6283 default_binds_local_p_1 (const_tree exp, int shlib)
6285 bool local_p;
6287 /* A non-decl is an entry in the constant pool. */
6288 if (!DECL_P (exp))
6289 local_p = true;
6290 /* Weakrefs may not bind locally, even though the weakref itself is
6291 always static and therefore local. */
6292 else if (lookup_attribute ("weakref", DECL_ATTRIBUTES (exp)))
6293 local_p = false;
6294 /* Static variables are always local. */
6295 else if (! TREE_PUBLIC (exp))
6296 local_p = true;
6297 /* A variable is local if the user has said explicitly that it will
6298 be. */
6299 else if (DECL_VISIBILITY_SPECIFIED (exp)
6300 && DECL_VISIBILITY (exp) != VISIBILITY_DEFAULT)
6301 local_p = true;
6302 /* Variables defined outside this object might not be local. */
6303 else if (DECL_EXTERNAL (exp))
6304 local_p = false;
6305 /* If defined in this object and visibility is not default, must be
6306 local. */
6307 else if (DECL_VISIBILITY (exp) != VISIBILITY_DEFAULT)
6308 local_p = true;
6309 /* Default visibility weak data can be overridden by a strong symbol
6310 in another module and so are not local. */
6311 else if (DECL_WEAK (exp))
6312 local_p = false;
6313 /* If PIC, then assume that any global name can be overridden by
6314 symbols resolved from other modules, unless we are compiling with
6315 -fwhole-program, which assumes that names are local. */
6316 else if (shlib)
6317 local_p = flag_whole_program;
6318 /* Uninitialized COMMON variable may be unified with symbols
6319 resolved from other modules. */
6320 else if (DECL_COMMON (exp)
6321 && (DECL_INITIAL (exp) == NULL
6322 || DECL_INITIAL (exp) == error_mark_node))
6323 local_p = false;
6324 /* Otherwise we're left with initialized (or non-common) global data
6325 which is of necessity defined locally. */
6326 else
6327 local_p = true;
6329 return local_p;
6332 /* Determine whether or not a pointer mode is valid. Assume defaults
6333 of ptr_mode or Pmode - can be overridden. */
6334 bool
6335 default_valid_pointer_mode (enum machine_mode mode)
6337 return (mode == ptr_mode || mode == Pmode);
6340 /* Default function to output code that will globalize a label. A
6341 target must define GLOBAL_ASM_OP or provide its own function to
6342 globalize a label. */
6343 #ifdef GLOBAL_ASM_OP
6344 void
6345 default_globalize_label (FILE * stream, const char *name)
6347 fputs (GLOBAL_ASM_OP, stream);
6348 assemble_name (stream, name);
6349 putc ('\n', stream);
6351 #endif /* GLOBAL_ASM_OP */
6353 /* Default function to output code that will globalize a declaration. */
6354 void
6355 default_globalize_decl_name (FILE * stream, tree decl)
6357 const char *name = XSTR (XEXP (DECL_RTL (decl), 0), 0);
6358 targetm.asm_out.globalize_label (stream, name);
6361 /* Default function to output a label for unwind information. The
6362 default is to do nothing. A target that needs nonlocal labels for
6363 unwind information must provide its own function to do this. */
6364 void
6365 default_emit_unwind_label (FILE * stream ATTRIBUTE_UNUSED,
6366 tree decl ATTRIBUTE_UNUSED,
6367 int for_eh ATTRIBUTE_UNUSED,
6368 int empty ATTRIBUTE_UNUSED)
6372 /* Default function to output a label to divide up the exception table.
6373 The default is to do nothing. A target that needs/wants to divide
6374 up the table must provide it's own function to do this. */
6375 void
6376 default_emit_except_table_label (FILE * stream ATTRIBUTE_UNUSED)
6380 /* This is how to output an internal numbered label where PREFIX is
6381 the class of label and LABELNO is the number within the class. */
6383 void
6384 default_internal_label (FILE *stream, const char *prefix,
6385 unsigned long labelno)
6387 char *const buf = (char *) alloca (40 + strlen (prefix));
6388 ASM_GENERATE_INTERNAL_LABEL (buf, prefix, labelno);
6389 ASM_OUTPUT_INTERNAL_LABEL (stream, buf);
6392 /* This is the default behavior at the beginning of a file. It's
6393 controlled by two other target-hook toggles. */
6394 void
6395 default_file_start (void)
6397 if (targetm.file_start_app_off
6398 && !(flag_verbose_asm || flag_debug_asm || flag_dump_rtl_in_asm))
6399 fputs (ASM_APP_OFF, asm_out_file);
6401 if (targetm.file_start_file_directive)
6402 output_file_directive (asm_out_file, main_input_filename);
6405 /* This is a generic routine suitable for use as TARGET_ASM_FILE_END
6406 which emits a special section directive used to indicate whether or
6407 not this object file needs an executable stack. This is primarily
6408 a GNU extension to ELF but could be used on other targets. */
6410 int trampolines_created;
6412 void
6413 file_end_indicate_exec_stack (void)
6415 unsigned int flags = SECTION_DEBUG;
6416 if (trampolines_created)
6417 flags |= SECTION_CODE;
6419 switch_to_section (get_section (".note.GNU-stack", flags, NULL));
6422 /* Output DIRECTIVE (a C string) followed by a newline. This is used as
6423 a get_unnamed_section callback. */
6425 void
6426 output_section_asm_op (const void *directive)
6428 fprintf (asm_out_file, "%s\n", (const char *) directive);
6431 /* Emit assembly code to switch to section NEW_SECTION. Do nothing if
6432 the current section is NEW_SECTION. */
6434 void
6435 switch_to_section (section *new_section)
6437 if (in_section == new_section)
6438 return;
6440 if (new_section->common.flags & SECTION_FORGET)
6441 in_section = NULL;
6442 else
6443 in_section = new_section;
6445 switch (SECTION_STYLE (new_section))
6447 case SECTION_NAMED:
6448 if (cfun
6449 && !crtl->subsections.unlikely_text_section_name
6450 && strcmp (new_section->named.name,
6451 UNLIKELY_EXECUTED_TEXT_SECTION_NAME) == 0)
6452 crtl->subsections.unlikely_text_section_name = UNLIKELY_EXECUTED_TEXT_SECTION_NAME;
6454 targetm.asm_out.named_section (new_section->named.name,
6455 new_section->named.common.flags,
6456 new_section->named.decl);
6457 break;
6459 case SECTION_UNNAMED:
6460 new_section->unnamed.callback (new_section->unnamed.data);
6461 break;
6463 case SECTION_NOSWITCH:
6464 gcc_unreachable ();
6465 break;
6468 new_section->common.flags |= SECTION_DECLARED;
6471 /* If block symbol SYMBOL has not yet been assigned an offset, place
6472 it at the end of its block. */
6474 void
6475 place_block_symbol (rtx symbol)
6477 unsigned HOST_WIDE_INT size, mask, offset;
6478 struct constant_descriptor_rtx *desc;
6479 unsigned int alignment;
6480 struct object_block *block;
6481 tree decl;
6483 gcc_assert (SYMBOL_REF_BLOCK (symbol));
6484 if (SYMBOL_REF_BLOCK_OFFSET (symbol) >= 0)
6485 return;
6487 /* Work out the symbol's size and alignment. */
6488 if (CONSTANT_POOL_ADDRESS_P (symbol))
6490 desc = SYMBOL_REF_CONSTANT (symbol);
6491 alignment = desc->align;
6492 size = GET_MODE_SIZE (desc->mode);
6494 else if (TREE_CONSTANT_POOL_ADDRESS_P (symbol))
6496 decl = SYMBOL_REF_DECL (symbol);
6497 alignment = get_constant_alignment (decl);
6498 size = get_constant_size (decl);
6500 else
6502 decl = SYMBOL_REF_DECL (symbol);
6503 alignment = DECL_ALIGN (decl);
6504 size = tree_low_cst (DECL_SIZE_UNIT (decl), 1);
6507 /* Calculate the object's offset from the start of the block. */
6508 block = SYMBOL_REF_BLOCK (symbol);
6509 mask = alignment / BITS_PER_UNIT - 1;
6510 offset = (block->size + mask) & ~mask;
6511 SYMBOL_REF_BLOCK_OFFSET (symbol) = offset;
6513 /* Record the block's new alignment and size. */
6514 block->alignment = MAX (block->alignment, alignment);
6515 block->size = offset + size;
6517 VEC_safe_push (rtx, gc, block->objects, symbol);
6520 /* Return the anchor that should be used to address byte offset OFFSET
6521 from the first object in BLOCK. MODEL is the TLS model used
6522 to access it. */
6525 get_section_anchor (struct object_block *block, HOST_WIDE_INT offset,
6526 enum tls_model model)
6528 char label[100];
6529 unsigned int begin, middle, end;
6530 unsigned HOST_WIDE_INT min_offset, max_offset, range, bias, delta;
6531 rtx anchor;
6533 /* Work out the anchor's offset. Use an offset of 0 for the first
6534 anchor so that we don't pessimize the case where we take the address
6535 of a variable at the beginning of the block. This is particularly
6536 useful when a block has only one variable assigned to it.
6538 We try to place anchors RANGE bytes apart, so there can then be
6539 anchors at +/-RANGE, +/-2 * RANGE, and so on, up to the limits of
6540 a ptr_mode offset. With some target settings, the lowest such
6541 anchor might be out of range for the lowest ptr_mode offset;
6542 likewise the highest anchor for the highest offset. Use anchors
6543 at the extreme ends of the ptr_mode range in such cases.
6545 All arithmetic uses unsigned integers in order to avoid
6546 signed overflow. */
6547 max_offset = (unsigned HOST_WIDE_INT) targetm.max_anchor_offset;
6548 min_offset = (unsigned HOST_WIDE_INT) targetm.min_anchor_offset;
6549 range = max_offset - min_offset + 1;
6550 if (range == 0)
6551 offset = 0;
6552 else
6554 bias = 1 << (GET_MODE_BITSIZE (ptr_mode) - 1);
6555 if (offset < 0)
6557 delta = -(unsigned HOST_WIDE_INT) offset + max_offset;
6558 delta -= delta % range;
6559 if (delta > bias)
6560 delta = bias;
6561 offset = (HOST_WIDE_INT) (-delta);
6563 else
6565 delta = (unsigned HOST_WIDE_INT) offset - min_offset;
6566 delta -= delta % range;
6567 if (delta > bias - 1)
6568 delta = bias - 1;
6569 offset = (HOST_WIDE_INT) delta;
6573 /* Do a binary search to see if there's already an anchor we can use.
6574 Set BEGIN to the new anchor's index if not. */
6575 begin = 0;
6576 end = VEC_length (rtx, block->anchors);
6577 while (begin != end)
6579 middle = (end + begin) / 2;
6580 anchor = VEC_index (rtx, block->anchors, middle);
6581 if (SYMBOL_REF_BLOCK_OFFSET (anchor) > offset)
6582 end = middle;
6583 else if (SYMBOL_REF_BLOCK_OFFSET (anchor) < offset)
6584 begin = middle + 1;
6585 else if (SYMBOL_REF_TLS_MODEL (anchor) > model)
6586 end = middle;
6587 else if (SYMBOL_REF_TLS_MODEL (anchor) < model)
6588 begin = middle + 1;
6589 else
6590 return anchor;
6593 /* Create a new anchor with a unique label. */
6594 ASM_GENERATE_INTERNAL_LABEL (label, "LANCHOR", anchor_labelno++);
6595 anchor = create_block_symbol (ggc_strdup (label), block, offset);
6596 SYMBOL_REF_FLAGS (anchor) |= SYMBOL_FLAG_LOCAL | SYMBOL_FLAG_ANCHOR;
6597 SYMBOL_REF_FLAGS (anchor) |= model << SYMBOL_FLAG_TLS_SHIFT;
6599 /* Insert it at index BEGIN. */
6600 VEC_safe_insert (rtx, gc, block->anchors, begin, anchor);
6601 return anchor;
6604 /* Output the objects in BLOCK. */
6606 static void
6607 output_object_block (struct object_block *block)
6609 struct constant_descriptor_rtx *desc;
6610 unsigned int i;
6611 HOST_WIDE_INT offset;
6612 tree decl;
6613 rtx symbol;
6615 if (block->objects == NULL)
6616 return;
6618 /* Switch to the section and make sure that the first byte is
6619 suitably aligned. */
6620 switch_to_section (block->sect);
6621 assemble_align (block->alignment);
6623 /* Define the values of all anchors relative to the current section
6624 position. */
6625 for (i = 0; VEC_iterate (rtx, block->anchors, i, symbol); i++)
6626 targetm.asm_out.output_anchor (symbol);
6628 /* Output the objects themselves. */
6629 offset = 0;
6630 for (i = 0; VEC_iterate (rtx, block->objects, i, symbol); i++)
6632 /* Move to the object's offset, padding with zeros if necessary. */
6633 assemble_zeros (SYMBOL_REF_BLOCK_OFFSET (symbol) - offset);
6634 offset = SYMBOL_REF_BLOCK_OFFSET (symbol);
6635 if (CONSTANT_POOL_ADDRESS_P (symbol))
6637 desc = SYMBOL_REF_CONSTANT (symbol);
6638 output_constant_pool_1 (desc, 1);
6639 offset += GET_MODE_SIZE (desc->mode);
6641 else if (TREE_CONSTANT_POOL_ADDRESS_P (symbol))
6643 decl = SYMBOL_REF_DECL (symbol);
6644 assemble_constant_contents (decl, XSTR (symbol, 0),
6645 get_constant_alignment (decl));
6646 offset += get_constant_size (decl);
6648 else
6650 decl = SYMBOL_REF_DECL (symbol);
6651 assemble_variable_contents (decl, XSTR (symbol, 0), false);
6652 offset += tree_low_cst (DECL_SIZE_UNIT (decl), 1);
6657 /* A htab_traverse callback used to call output_object_block for
6658 each member of object_block_htab. */
6660 static int
6661 output_object_block_htab (void **slot, void *data ATTRIBUTE_UNUSED)
6663 output_object_block ((struct object_block *) (*slot));
6664 return 1;
6667 /* Output the definitions of all object_blocks. */
6669 void
6670 output_object_blocks (void)
6672 htab_traverse (object_block_htab, output_object_block_htab, NULL);
6675 /* This function provides a possible implementation of the
6676 TARGET_ASM_RECORD_GCC_SWITCHES target hook for ELF targets. When triggered
6677 by -frecord-gcc-switches it creates a new mergeable, string section in the
6678 assembler output file called TARGET_ASM_RECORD_GCC_SWITCHES_SECTION which
6679 contains the switches in ASCII format.
6681 FIXME: This code does not correctly handle double quote characters
6682 that appear inside strings, (it strips them rather than preserving them).
6683 FIXME: ASM_OUTPUT_ASCII, as defined in config/elfos.h will not emit NUL
6684 characters - instead it treats them as sub-string separators. Since
6685 we want to emit NUL strings terminators into the object file we have to use
6686 ASM_OUTPUT_SKIP. */
6689 elf_record_gcc_switches (print_switch_type type, const char * name)
6691 static char buffer[1024];
6693 /* This variable is used as part of a simplistic heuristic to detect
6694 command line switches which take an argument:
6696 "If a command line option does not start with a dash then
6697 it is an argument for the previous command line option."
6699 This fails in the case of the command line option which is the name
6700 of the file to compile, but otherwise it is pretty reasonable. */
6701 static bool previous_name_held_back = FALSE;
6703 switch (type)
6705 case SWITCH_TYPE_PASSED:
6706 if (* name != '-')
6708 if (previous_name_held_back)
6710 unsigned int len = strlen (buffer);
6712 snprintf (buffer + len, sizeof buffer - len, " %s", name);
6713 ASM_OUTPUT_ASCII (asm_out_file, buffer, strlen (buffer));
6714 ASM_OUTPUT_SKIP (asm_out_file, (unsigned HOST_WIDE_INT) 1);
6715 previous_name_held_back = FALSE;
6717 else
6719 strncpy (buffer, name, sizeof buffer);
6720 ASM_OUTPUT_ASCII (asm_out_file, buffer, strlen (buffer));
6721 ASM_OUTPUT_SKIP (asm_out_file, (unsigned HOST_WIDE_INT) 1);
6724 else
6726 if (previous_name_held_back)
6728 ASM_OUTPUT_ASCII (asm_out_file, buffer, strlen (buffer));
6729 ASM_OUTPUT_SKIP (asm_out_file, (unsigned HOST_WIDE_INT) 1);
6732 strncpy (buffer, name, sizeof buffer);
6733 previous_name_held_back = TRUE;
6735 break;
6737 case SWITCH_TYPE_DESCRIPTIVE:
6738 if (name == NULL)
6740 /* Distinguish between invocations where name is NULL. */
6741 static bool started = false;
6743 if (started)
6745 if (previous_name_held_back)
6747 ASM_OUTPUT_ASCII (asm_out_file, buffer, strlen (buffer));
6748 ASM_OUTPUT_SKIP (asm_out_file, (unsigned HOST_WIDE_INT) 1);
6751 else
6753 section * sec;
6755 sec = get_section (targetm.asm_out.record_gcc_switches_section,
6756 SECTION_DEBUG
6757 | SECTION_MERGE
6758 | SECTION_STRINGS
6759 | (SECTION_ENTSIZE & 1),
6760 NULL);
6761 switch_to_section (sec);
6762 started = true;
6766 default:
6767 break;
6770 /* The return value is currently ignored by the caller, but must be 0.
6771 For -fverbose-asm the return value would be the number of characters
6772 emitted into the assembler file. */
6773 return 0;
6776 /* Emit text to declare externally defined symbols. It is needed to
6777 properly support non-default visibility. */
6778 void
6779 default_elf_asm_output_external (FILE *file ATTRIBUTE_UNUSED,
6780 tree decl,
6781 const char *name ATTRIBUTE_UNUSED)
6783 /* We output the name if and only if TREE_SYMBOL_REFERENCED is
6784 set in order to avoid putting out names that are never really
6785 used. */
6786 if (TREE_SYMBOL_REFERENCED (DECL_ASSEMBLER_NAME (decl))
6787 && targetm.binds_local_p (decl))
6788 maybe_assemble_visibility (decl);
6791 #include "gt-varasm.h"