PR rtl-optimization/33642
[official-gcc.git] / gcc / varasm.c
blobb3f99907990799c939e416b9ed37747435558af8
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 (Most assemblers don't need this, so we normally output nothing.)
2295 Do nothing if DECL is not external. */
2297 void
2298 assemble_external (tree decl ATTRIBUTE_UNUSED)
2300 /* Because most platforms do not define ASM_OUTPUT_EXTERNAL, the
2301 main body of this code is only rarely exercised. To provide some
2302 testing, on all platforms, we make sure that the ASM_OUT_FILE is
2303 open. If it's not, we should not be calling this function. */
2304 gcc_assert (asm_out_file);
2306 #ifdef ASM_OUTPUT_EXTERNAL
2307 if (!DECL_P (decl) || !DECL_EXTERNAL (decl) || !TREE_PUBLIC (decl))
2308 return;
2310 if (SUPPORTS_WEAK && DECL_WEAK (decl))
2311 weak_decls = tree_cons (NULL, decl, weak_decls);
2313 /* We want to output external symbols at very last to check if they
2314 are references or not. */
2315 pending_assemble_externals = tree_cons (0, decl,
2316 pending_assemble_externals);
2317 #endif
2320 /* Similar, for calling a library function FUN. */
2322 void
2323 assemble_external_libcall (rtx fun)
2325 /* Declare library function name external when first used, if nec. */
2326 if (! SYMBOL_REF_USED (fun))
2328 SYMBOL_REF_USED (fun) = 1;
2329 targetm.asm_out.external_libcall (fun);
2333 /* Assemble a label named NAME. */
2335 void
2336 assemble_label (const char *name)
2338 ASM_OUTPUT_LABEL (asm_out_file, name);
2341 /* Set the symbol_referenced flag for ID. */
2342 void
2343 mark_referenced (tree id)
2345 TREE_SYMBOL_REFERENCED (id) = 1;
2348 /* Set the symbol_referenced flag for DECL and notify callgraph. */
2349 void
2350 mark_decl_referenced (tree decl)
2352 if (TREE_CODE (decl) == FUNCTION_DECL)
2354 /* Extern inline functions don't become needed when referenced.
2355 If we know a method will be emitted in other TU and no new
2356 functions can be marked reachable, just use the external
2357 definition. */
2358 struct cgraph_node *node = cgraph_node (decl);
2359 if (!DECL_EXTERNAL (decl)
2360 && (!node->local.vtable_method || !cgraph_global_info_ready
2361 || !node->local.finalized))
2362 cgraph_mark_needed_node (node);
2364 else if (TREE_CODE (decl) == VAR_DECL)
2366 struct varpool_node *node = varpool_node (decl);
2367 varpool_mark_needed_node (node);
2368 /* C++ frontend use mark_decl_references to force COMDAT variables
2369 to be output that might appear dead otherwise. */
2370 node->force_output = true;
2372 /* else do nothing - we can get various sorts of CST nodes here,
2373 which do not need to be marked. */
2377 /* Follow the IDENTIFIER_TRANSPARENT_ALIAS chain starting at *ALIAS
2378 until we find an identifier that is not itself a transparent alias.
2379 Modify the alias passed to it by reference (and all aliases on the
2380 way to the ultimate target), such that they do not have to be
2381 followed again, and return the ultimate target of the alias
2382 chain. */
2384 static inline tree
2385 ultimate_transparent_alias_target (tree *alias)
2387 tree target = *alias;
2389 if (IDENTIFIER_TRANSPARENT_ALIAS (target))
2391 gcc_assert (TREE_CHAIN (target));
2392 target = ultimate_transparent_alias_target (&TREE_CHAIN (target));
2393 gcc_assert (! IDENTIFIER_TRANSPARENT_ALIAS (target)
2394 && ! TREE_CHAIN (target));
2395 *alias = target;
2398 return target;
2401 /* Output to FILE (an assembly file) a reference to NAME. If NAME
2402 starts with a *, the rest of NAME is output verbatim. Otherwise
2403 NAME is transformed in a target-specific way (usually by the
2404 addition of an underscore). */
2406 void
2407 assemble_name_raw (FILE *file, const char *name)
2409 if (name[0] == '*')
2410 fputs (&name[1], file);
2411 else
2412 ASM_OUTPUT_LABELREF (file, name);
2415 /* Like assemble_name_raw, but should be used when NAME might refer to
2416 an entity that is also represented as a tree (like a function or
2417 variable). If NAME does refer to such an entity, that entity will
2418 be marked as referenced. */
2420 void
2421 assemble_name (FILE *file, const char *name)
2423 const char *real_name;
2424 tree id;
2426 real_name = targetm.strip_name_encoding (name);
2428 id = maybe_get_identifier (real_name);
2429 if (id)
2431 tree id_orig = id;
2433 mark_referenced (id);
2434 ultimate_transparent_alias_target (&id);
2435 if (id != id_orig)
2436 name = IDENTIFIER_POINTER (id);
2437 gcc_assert (! TREE_CHAIN (id));
2440 assemble_name_raw (file, name);
2443 /* Allocate SIZE bytes writable static space with a gensym name
2444 and return an RTX to refer to its address. */
2447 assemble_static_space (unsigned HOST_WIDE_INT size)
2449 char name[12];
2450 const char *namestring;
2451 rtx x;
2453 ASM_GENERATE_INTERNAL_LABEL (name, "LF", const_labelno);
2454 ++const_labelno;
2455 namestring = ggc_strdup (name);
2457 x = gen_rtx_SYMBOL_REF (Pmode, namestring);
2458 SYMBOL_REF_FLAGS (x) = SYMBOL_FLAG_LOCAL;
2460 #ifdef ASM_OUTPUT_ALIGNED_DECL_LOCAL
2461 ASM_OUTPUT_ALIGNED_DECL_LOCAL (asm_out_file, NULL_TREE, name, size,
2462 BIGGEST_ALIGNMENT);
2463 #else
2464 #ifdef ASM_OUTPUT_ALIGNED_LOCAL
2465 ASM_OUTPUT_ALIGNED_LOCAL (asm_out_file, name, size, BIGGEST_ALIGNMENT);
2466 #else
2468 /* Round size up to multiple of BIGGEST_ALIGNMENT bits
2469 so that each uninitialized object starts on such a boundary. */
2470 /* Variable `rounded' might or might not be used in ASM_OUTPUT_LOCAL. */
2471 unsigned HOST_WIDE_INT rounded ATTRIBUTE_UNUSED
2472 = ((size + (BIGGEST_ALIGNMENT / BITS_PER_UNIT) - 1)
2473 / (BIGGEST_ALIGNMENT / BITS_PER_UNIT)
2474 * (BIGGEST_ALIGNMENT / BITS_PER_UNIT));
2475 ASM_OUTPUT_LOCAL (asm_out_file, name, size, rounded);
2477 #endif
2478 #endif
2479 return x;
2482 /* Assemble the static constant template for function entry trampolines.
2483 This is done at most once per compilation.
2484 Returns an RTX for the address of the template. */
2486 static GTY(()) rtx initial_trampoline;
2488 #ifdef TRAMPOLINE_TEMPLATE
2490 assemble_trampoline_template (void)
2492 char label[256];
2493 const char *name;
2494 int align;
2495 rtx symbol;
2497 if (initial_trampoline)
2498 return initial_trampoline;
2500 /* By default, put trampoline templates in read-only data section. */
2502 #ifdef TRAMPOLINE_SECTION
2503 switch_to_section (TRAMPOLINE_SECTION);
2504 #else
2505 switch_to_section (readonly_data_section);
2506 #endif
2508 /* Write the assembler code to define one. */
2509 align = floor_log2 (TRAMPOLINE_ALIGNMENT / BITS_PER_UNIT);
2510 if (align > 0)
2512 ASM_OUTPUT_ALIGN (asm_out_file, align);
2515 targetm.asm_out.internal_label (asm_out_file, "LTRAMP", 0);
2516 TRAMPOLINE_TEMPLATE (asm_out_file);
2518 /* Record the rtl to refer to it. */
2519 ASM_GENERATE_INTERNAL_LABEL (label, "LTRAMP", 0);
2520 name = ggc_strdup (label);
2521 symbol = gen_rtx_SYMBOL_REF (Pmode, name);
2522 SYMBOL_REF_FLAGS (symbol) = SYMBOL_FLAG_LOCAL;
2524 initial_trampoline = gen_rtx_MEM (BLKmode, symbol);
2525 set_mem_align (initial_trampoline, TRAMPOLINE_ALIGNMENT);
2527 return initial_trampoline;
2529 #endif
2531 /* A and B are either alignments or offsets. Return the minimum alignment
2532 that may be assumed after adding the two together. */
2534 static inline unsigned
2535 min_align (unsigned int a, unsigned int b)
2537 return (a | b) & -(a | b);
2540 /* Return the assembler directive for creating a given kind of integer
2541 object. SIZE is the number of bytes in the object and ALIGNED_P
2542 indicates whether it is known to be aligned. Return NULL if the
2543 assembly dialect has no such directive.
2545 The returned string should be printed at the start of a new line and
2546 be followed immediately by the object's initial value. */
2548 const char *
2549 integer_asm_op (int size, int aligned_p)
2551 struct asm_int_op *ops;
2553 if (aligned_p)
2554 ops = &targetm.asm_out.aligned_op;
2555 else
2556 ops = &targetm.asm_out.unaligned_op;
2558 switch (size)
2560 case 1:
2561 return targetm.asm_out.byte_op;
2562 case 2:
2563 return ops->hi;
2564 case 4:
2565 return ops->si;
2566 case 8:
2567 return ops->di;
2568 case 16:
2569 return ops->ti;
2570 default:
2571 return NULL;
2575 /* Use directive OP to assemble an integer object X. Print OP at the
2576 start of the line, followed immediately by the value of X. */
2578 void
2579 assemble_integer_with_op (const char *op, rtx x)
2581 fputs (op, asm_out_file);
2582 output_addr_const (asm_out_file, x);
2583 fputc ('\n', asm_out_file);
2586 /* The default implementation of the asm_out.integer target hook. */
2588 bool
2589 default_assemble_integer (rtx x ATTRIBUTE_UNUSED,
2590 unsigned int size ATTRIBUTE_UNUSED,
2591 int aligned_p ATTRIBUTE_UNUSED)
2593 const char *op = integer_asm_op (size, aligned_p);
2594 /* Avoid GAS bugs for large values. Specifically negative values whose
2595 absolute value fits in a bfd_vma, but not in a bfd_signed_vma. */
2596 if (size > UNITS_PER_WORD && size > POINTER_SIZE / BITS_PER_UNIT)
2597 return false;
2598 return op && (assemble_integer_with_op (op, x), true);
2601 /* Assemble the integer constant X into an object of SIZE bytes. ALIGN is
2602 the alignment of the integer in bits. Return 1 if we were able to output
2603 the constant, otherwise 0. We must be able to output the constant,
2604 if FORCE is nonzero. */
2606 bool
2607 assemble_integer (rtx x, unsigned int size, unsigned int align, int force)
2609 int aligned_p;
2611 aligned_p = (align >= MIN (size * BITS_PER_UNIT, BIGGEST_ALIGNMENT));
2613 /* See if the target hook can handle this kind of object. */
2614 if (targetm.asm_out.integer (x, size, aligned_p))
2615 return true;
2617 /* If the object is a multi-byte one, try splitting it up. Split
2618 it into words it if is multi-word, otherwise split it into bytes. */
2619 if (size > 1)
2621 enum machine_mode omode, imode;
2622 unsigned int subalign;
2623 unsigned int subsize, i;
2624 unsigned char mclass;
2626 subsize = size > UNITS_PER_WORD? UNITS_PER_WORD : 1;
2627 subalign = MIN (align, subsize * BITS_PER_UNIT);
2628 if (GET_CODE (x) == CONST_FIXED)
2629 mclass = GET_MODE_CLASS (GET_MODE (x));
2630 else
2631 mclass = MODE_INT;
2633 omode = mode_for_size (subsize * BITS_PER_UNIT, mclass, 0);
2634 imode = mode_for_size (size * BITS_PER_UNIT, mclass, 0);
2636 for (i = 0; i < size; i += subsize)
2638 rtx partial = simplify_subreg (omode, x, imode, i);
2639 if (!partial || !assemble_integer (partial, subsize, subalign, 0))
2640 break;
2642 if (i == size)
2643 return true;
2645 /* If we've printed some of it, but not all of it, there's no going
2646 back now. */
2647 gcc_assert (!i);
2650 gcc_assert (!force);
2652 return false;
2655 void
2656 assemble_real (REAL_VALUE_TYPE d, enum machine_mode mode, unsigned int align)
2658 long data[4] = {0, 0, 0, 0};
2659 int i;
2660 int bitsize, nelts, nunits, units_per;
2662 /* This is hairy. We have a quantity of known size. real_to_target
2663 will put it into an array of *host* longs, 32 bits per element
2664 (even if long is more than 32 bits). We need to determine the
2665 number of array elements that are occupied (nelts) and the number
2666 of *target* min-addressable units that will be occupied in the
2667 object file (nunits). We cannot assume that 32 divides the
2668 mode's bitsize (size * BITS_PER_UNIT) evenly.
2670 size * BITS_PER_UNIT is used here to make sure that padding bits
2671 (which might appear at either end of the value; real_to_target
2672 will include the padding bits in its output array) are included. */
2674 nunits = GET_MODE_SIZE (mode);
2675 bitsize = nunits * BITS_PER_UNIT;
2676 nelts = CEIL (bitsize, 32);
2677 units_per = 32 / BITS_PER_UNIT;
2679 real_to_target (data, &d, mode);
2681 /* Put out the first word with the specified alignment. */
2682 assemble_integer (GEN_INT (data[0]), MIN (nunits, units_per), align, 1);
2683 nunits -= units_per;
2685 /* Subsequent words need only 32-bit alignment. */
2686 align = min_align (align, 32);
2688 for (i = 1; i < nelts; i++)
2690 assemble_integer (GEN_INT (data[i]), MIN (nunits, units_per), align, 1);
2691 nunits -= units_per;
2695 /* Given an expression EXP with a constant value,
2696 reduce it to the sum of an assembler symbol and an integer.
2697 Store them both in the structure *VALUE.
2698 EXP must be reducible. */
2700 struct addr_const GTY(())
2702 rtx base;
2703 HOST_WIDE_INT offset;
2706 static void
2707 decode_addr_const (tree exp, struct addr_const *value)
2709 tree target = TREE_OPERAND (exp, 0);
2710 int offset = 0;
2711 rtx x;
2713 while (1)
2715 if (TREE_CODE (target) == COMPONENT_REF
2716 && host_integerp (byte_position (TREE_OPERAND (target, 1)), 0))
2719 offset += int_byte_position (TREE_OPERAND (target, 1));
2720 target = TREE_OPERAND (target, 0);
2722 else if (TREE_CODE (target) == ARRAY_REF
2723 || TREE_CODE (target) == ARRAY_RANGE_REF)
2725 offset += (tree_low_cst (TYPE_SIZE_UNIT (TREE_TYPE (target)), 1)
2726 * tree_low_cst (TREE_OPERAND (target, 1), 0));
2727 target = TREE_OPERAND (target, 0);
2729 else
2730 break;
2733 switch (TREE_CODE (target))
2735 case VAR_DECL:
2736 case FUNCTION_DECL:
2737 x = DECL_RTL (target);
2738 break;
2740 case LABEL_DECL:
2741 x = gen_rtx_MEM (FUNCTION_MODE,
2742 gen_rtx_LABEL_REF (Pmode, force_label_rtx (target)));
2743 break;
2745 case REAL_CST:
2746 case FIXED_CST:
2747 case STRING_CST:
2748 case COMPLEX_CST:
2749 case CONSTRUCTOR:
2750 case INTEGER_CST:
2751 x = output_constant_def (target, 1);
2752 break;
2754 default:
2755 gcc_unreachable ();
2758 gcc_assert (MEM_P (x));
2759 x = XEXP (x, 0);
2761 value->base = x;
2762 value->offset = offset;
2765 /* Uniquize all constants that appear in memory.
2766 Each constant in memory thus far output is recorded
2767 in `const_desc_table'. */
2769 struct constant_descriptor_tree GTY(())
2771 /* A MEM for the constant. */
2772 rtx rtl;
2774 /* The value of the constant. */
2775 tree value;
2777 /* Hash of value. Computing the hash from value each time
2778 hashfn is called can't work properly, as that means recursive
2779 use of the hash table during hash table expansion. */
2780 hashval_t hash;
2783 static GTY((param_is (struct constant_descriptor_tree)))
2784 htab_t const_desc_htab;
2786 static struct constant_descriptor_tree * build_constant_desc (tree);
2787 static void maybe_output_constant_def_contents (struct constant_descriptor_tree *, int);
2789 /* Compute a hash code for a constant expression. */
2791 static hashval_t
2792 const_desc_hash (const void *ptr)
2794 return ((const struct constant_descriptor_tree *)ptr)->hash;
2797 static hashval_t
2798 const_hash_1 (const tree exp)
2800 const char *p;
2801 hashval_t hi;
2802 int len, i;
2803 enum tree_code code = TREE_CODE (exp);
2805 /* Either set P and LEN to the address and len of something to hash and
2806 exit the switch or return a value. */
2808 switch (code)
2810 case INTEGER_CST:
2811 p = (char *) &TREE_INT_CST (exp);
2812 len = sizeof TREE_INT_CST (exp);
2813 break;
2815 case REAL_CST:
2816 return real_hash (TREE_REAL_CST_PTR (exp));
2818 case FIXED_CST:
2819 return fixed_hash (TREE_FIXED_CST_PTR (exp));
2821 case STRING_CST:
2822 p = TREE_STRING_POINTER (exp);
2823 len = TREE_STRING_LENGTH (exp);
2824 break;
2826 case COMPLEX_CST:
2827 return (const_hash_1 (TREE_REALPART (exp)) * 5
2828 + const_hash_1 (TREE_IMAGPART (exp)));
2830 case CONSTRUCTOR:
2832 unsigned HOST_WIDE_INT idx;
2833 tree value;
2835 hi = 5 + int_size_in_bytes (TREE_TYPE (exp));
2837 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (exp), idx, value)
2838 if (value)
2839 hi = hi * 603 + const_hash_1 (value);
2841 return hi;
2844 case ADDR_EXPR:
2845 case FDESC_EXPR:
2847 struct addr_const value;
2849 decode_addr_const (exp, &value);
2850 switch (GET_CODE (value.base))
2852 case SYMBOL_REF:
2853 /* Don't hash the address of the SYMBOL_REF;
2854 only use the offset and the symbol name. */
2855 hi = value.offset;
2856 p = XSTR (value.base, 0);
2857 for (i = 0; p[i] != 0; i++)
2858 hi = ((hi * 613) + (unsigned) (p[i]));
2859 break;
2861 case LABEL_REF:
2862 hi = value.offset + CODE_LABEL_NUMBER (XEXP (value.base, 0)) * 13;
2863 break;
2865 default:
2866 gcc_unreachable ();
2869 return hi;
2871 case PLUS_EXPR:
2872 case POINTER_PLUS_EXPR:
2873 case MINUS_EXPR:
2874 return (const_hash_1 (TREE_OPERAND (exp, 0)) * 9
2875 + const_hash_1 (TREE_OPERAND (exp, 1)));
2877 CASE_CONVERT:
2878 return const_hash_1 (TREE_OPERAND (exp, 0)) * 7 + 2;
2880 default:
2881 /* A language specific constant. Just hash the code. */
2882 return code;
2885 /* Compute hashing function. */
2886 hi = len;
2887 for (i = 0; i < len; i++)
2888 hi = ((hi * 613) + (unsigned) (p[i]));
2890 return hi;
2893 /* Wrapper of compare_constant, for the htab interface. */
2894 static int
2895 const_desc_eq (const void *p1, const void *p2)
2897 const struct constant_descriptor_tree *const c1
2898 = (const struct constant_descriptor_tree *) p1;
2899 const struct constant_descriptor_tree *const c2
2900 = (const struct constant_descriptor_tree *) p2;
2901 if (c1->hash != c2->hash)
2902 return 0;
2903 return compare_constant (c1->value, c2->value);
2906 /* Compare t1 and t2, and return 1 only if they are known to result in
2907 the same bit pattern on output. */
2909 static int
2910 compare_constant (const tree t1, const tree t2)
2912 enum tree_code typecode;
2914 if (t1 == NULL_TREE)
2915 return t2 == NULL_TREE;
2916 if (t2 == NULL_TREE)
2917 return 0;
2919 if (TREE_CODE (t1) != TREE_CODE (t2))
2920 return 0;
2922 switch (TREE_CODE (t1))
2924 case INTEGER_CST:
2925 /* Integer constants are the same only if the same width of type. */
2926 if (TYPE_PRECISION (TREE_TYPE (t1)) != TYPE_PRECISION (TREE_TYPE (t2)))
2927 return 0;
2928 if (TYPE_MODE (TREE_TYPE (t1)) != TYPE_MODE (TREE_TYPE (t2)))
2929 return 0;
2930 return tree_int_cst_equal (t1, t2);
2932 case REAL_CST:
2933 /* Real 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;
2937 return REAL_VALUES_IDENTICAL (TREE_REAL_CST (t1), TREE_REAL_CST (t2));
2939 case FIXED_CST:
2940 /* Fixed constants are the same only if the same width of type. */
2941 if (TYPE_PRECISION (TREE_TYPE (t1)) != TYPE_PRECISION (TREE_TYPE (t2)))
2942 return 0;
2944 return FIXED_VALUES_IDENTICAL (TREE_FIXED_CST (t1), TREE_FIXED_CST (t2));
2946 case STRING_CST:
2947 if (TYPE_MODE (TREE_TYPE (t1)) != TYPE_MODE (TREE_TYPE (t2)))
2948 return 0;
2950 return (TREE_STRING_LENGTH (t1) == TREE_STRING_LENGTH (t2)
2951 && ! memcmp (TREE_STRING_POINTER (t1), TREE_STRING_POINTER (t2),
2952 TREE_STRING_LENGTH (t1)));
2954 case COMPLEX_CST:
2955 return (compare_constant (TREE_REALPART (t1), TREE_REALPART (t2))
2956 && compare_constant (TREE_IMAGPART (t1), TREE_IMAGPART (t2)));
2958 case CONSTRUCTOR:
2960 VEC(constructor_elt, gc) *v1, *v2;
2961 unsigned HOST_WIDE_INT idx;
2963 typecode = TREE_CODE (TREE_TYPE (t1));
2964 if (typecode != TREE_CODE (TREE_TYPE (t2)))
2965 return 0;
2967 if (typecode == ARRAY_TYPE)
2969 HOST_WIDE_INT size_1 = int_size_in_bytes (TREE_TYPE (t1));
2970 /* For arrays, check that the sizes all match. */
2971 if (TYPE_MODE (TREE_TYPE (t1)) != TYPE_MODE (TREE_TYPE (t2))
2972 || size_1 == -1
2973 || size_1 != int_size_in_bytes (TREE_TYPE (t2)))
2974 return 0;
2976 else
2978 /* For record and union constructors, require exact type
2979 equality. */
2980 if (TREE_TYPE (t1) != TREE_TYPE (t2))
2981 return 0;
2984 v1 = CONSTRUCTOR_ELTS (t1);
2985 v2 = CONSTRUCTOR_ELTS (t2);
2986 if (VEC_length (constructor_elt, v1)
2987 != VEC_length (constructor_elt, v2))
2988 return 0;
2990 for (idx = 0; idx < VEC_length (constructor_elt, v1); ++idx)
2992 constructor_elt *c1 = VEC_index (constructor_elt, v1, idx);
2993 constructor_elt *c2 = VEC_index (constructor_elt, v2, idx);
2995 /* Check that each value is the same... */
2996 if (!compare_constant (c1->value, c2->value))
2997 return 0;
2998 /* ... and that they apply to the same fields! */
2999 if (typecode == ARRAY_TYPE)
3001 if (!compare_constant (c1->index, c2->index))
3002 return 0;
3004 else
3006 if (c1->index != c2->index)
3007 return 0;
3011 return 1;
3014 case ADDR_EXPR:
3015 case FDESC_EXPR:
3017 struct addr_const value1, value2;
3019 decode_addr_const (t1, &value1);
3020 decode_addr_const (t2, &value2);
3021 return (value1.offset == value2.offset
3022 && strcmp (XSTR (value1.base, 0), XSTR (value2.base, 0)) == 0);
3025 case PLUS_EXPR:
3026 case POINTER_PLUS_EXPR:
3027 case MINUS_EXPR:
3028 case RANGE_EXPR:
3029 return (compare_constant (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0))
3030 && compare_constant(TREE_OPERAND (t1, 1), TREE_OPERAND (t2, 1)));
3032 CASE_CONVERT:
3033 case VIEW_CONVERT_EXPR:
3034 return compare_constant (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
3036 default:
3037 return 0;
3040 gcc_unreachable ();
3043 /* Make a copy of the whole tree structure for a constant. This
3044 handles the same types of nodes that compare_constant handles. */
3046 static tree
3047 copy_constant (tree exp)
3049 switch (TREE_CODE (exp))
3051 case ADDR_EXPR:
3052 /* For ADDR_EXPR, we do not want to copy the decl whose address
3053 is requested. We do want to copy constants though. */
3054 if (CONSTANT_CLASS_P (TREE_OPERAND (exp, 0)))
3055 return build1 (TREE_CODE (exp), TREE_TYPE (exp),
3056 copy_constant (TREE_OPERAND (exp, 0)));
3057 else
3058 return copy_node (exp);
3060 case INTEGER_CST:
3061 case REAL_CST:
3062 case FIXED_CST:
3063 case STRING_CST:
3064 return copy_node (exp);
3066 case COMPLEX_CST:
3067 return build_complex (TREE_TYPE (exp),
3068 copy_constant (TREE_REALPART (exp)),
3069 copy_constant (TREE_IMAGPART (exp)));
3071 case PLUS_EXPR:
3072 case POINTER_PLUS_EXPR:
3073 case MINUS_EXPR:
3074 return build2 (TREE_CODE (exp), TREE_TYPE (exp),
3075 copy_constant (TREE_OPERAND (exp, 0)),
3076 copy_constant (TREE_OPERAND (exp, 1)));
3078 CASE_CONVERT:
3079 case VIEW_CONVERT_EXPR:
3080 return build1 (TREE_CODE (exp), TREE_TYPE (exp),
3081 copy_constant (TREE_OPERAND (exp, 0)));
3083 case CONSTRUCTOR:
3085 tree copy = copy_node (exp);
3086 VEC(constructor_elt, gc) *v;
3087 unsigned HOST_WIDE_INT idx;
3088 tree purpose, value;
3090 v = VEC_alloc(constructor_elt, gc, VEC_length(constructor_elt,
3091 CONSTRUCTOR_ELTS (exp)));
3092 FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (exp), idx, purpose, value)
3094 constructor_elt *ce = VEC_quick_push (constructor_elt, v, NULL);
3095 ce->index = purpose;
3096 ce->value = copy_constant (value);
3098 CONSTRUCTOR_ELTS (copy) = v;
3099 return copy;
3102 default:
3103 gcc_unreachable ();
3107 /* Return the alignment of constant EXP in bits. */
3109 static unsigned int
3110 get_constant_alignment (tree exp)
3112 unsigned int align;
3114 align = TYPE_ALIGN (TREE_TYPE (exp));
3115 #ifdef CONSTANT_ALIGNMENT
3116 align = CONSTANT_ALIGNMENT (exp, align);
3117 #endif
3118 return align;
3121 /* Return the section into which constant EXP should be placed. */
3123 static section *
3124 get_constant_section (tree exp)
3126 if (IN_NAMED_SECTION (exp))
3127 return get_named_section (exp, NULL, compute_reloc_for_constant (exp));
3128 else
3129 return targetm.asm_out.select_section (exp,
3130 compute_reloc_for_constant (exp),
3131 get_constant_alignment (exp));
3134 /* Return the size of constant EXP in bytes. */
3136 static HOST_WIDE_INT
3137 get_constant_size (tree exp)
3139 HOST_WIDE_INT size;
3141 size = int_size_in_bytes (TREE_TYPE (exp));
3142 if (TREE_CODE (exp) == STRING_CST)
3143 size = MAX (TREE_STRING_LENGTH (exp), size);
3144 return size;
3147 /* Subroutine of output_constant_def:
3148 No constant equal to EXP is known to have been output.
3149 Make a constant descriptor to enter EXP in the hash table.
3150 Assign the label number and construct RTL to refer to the
3151 constant's location in memory.
3152 Caller is responsible for updating the hash table. */
3154 static struct constant_descriptor_tree *
3155 build_constant_desc (tree exp)
3157 rtx symbol;
3158 rtx rtl;
3159 char label[256];
3160 int labelno;
3161 struct constant_descriptor_tree *desc;
3163 desc = GGC_NEW (struct constant_descriptor_tree);
3164 desc->value = copy_constant (exp);
3166 /* Propagate marked-ness to copied constant. */
3167 if (flag_mudflap && mf_marked_p (exp))
3168 mf_mark (desc->value);
3170 /* Create a string containing the label name, in LABEL. */
3171 labelno = const_labelno++;
3172 ASM_GENERATE_INTERNAL_LABEL (label, "LC", labelno);
3174 /* We have a symbol name; construct the SYMBOL_REF and the MEM. */
3175 if (use_object_blocks_p ())
3177 section *sect = get_constant_section (exp);
3178 symbol = create_block_symbol (ggc_strdup (label),
3179 get_block_for_section (sect), -1);
3181 else
3182 symbol = gen_rtx_SYMBOL_REF (Pmode, ggc_strdup (label));
3183 SYMBOL_REF_FLAGS (symbol) |= SYMBOL_FLAG_LOCAL;
3184 SET_SYMBOL_REF_DECL (symbol, desc->value);
3185 TREE_CONSTANT_POOL_ADDRESS_P (symbol) = 1;
3187 rtl = gen_rtx_MEM (TYPE_MODE (TREE_TYPE (exp)), symbol);
3188 set_mem_attributes (rtl, exp, 1);
3189 set_mem_alias_set (rtl, 0);
3190 set_mem_alias_set (rtl, const_alias_set);
3192 /* Set flags or add text to the name to record information, such as
3193 that it is a local symbol. If the name is changed, the macro
3194 ASM_OUTPUT_LABELREF will have to know how to strip this
3195 information. This call might invalidate our local variable
3196 SYMBOL; we can't use it afterward. */
3198 targetm.encode_section_info (exp, rtl, true);
3200 desc->rtl = rtl;
3202 return desc;
3205 /* Return an rtx representing a reference to constant data in memory
3206 for the constant expression EXP.
3208 If assembler code for such a constant has already been output,
3209 return an rtx to refer to it.
3210 Otherwise, output such a constant in memory
3211 and generate an rtx for it.
3213 If DEFER is nonzero, this constant can be deferred and output only
3214 if referenced in the function after all optimizations.
3216 `const_desc_table' records which constants already have label strings. */
3219 output_constant_def (tree exp, int defer)
3221 struct constant_descriptor_tree *desc;
3222 struct constant_descriptor_tree key;
3223 void **loc;
3225 /* Look up EXP in the table of constant descriptors. If we didn't find
3226 it, create a new one. */
3227 key.value = exp;
3228 key.hash = const_hash_1 (exp);
3229 loc = htab_find_slot_with_hash (const_desc_htab, &key, key.hash, INSERT);
3231 desc = (struct constant_descriptor_tree *) *loc;
3232 if (desc == 0)
3234 desc = build_constant_desc (exp);
3235 desc->hash = key.hash;
3236 *loc = desc;
3239 maybe_output_constant_def_contents (desc, defer);
3240 return desc->rtl;
3243 /* Subroutine of output_constant_def: Decide whether or not we need to
3244 output the constant DESC now, and if so, do it. */
3245 static void
3246 maybe_output_constant_def_contents (struct constant_descriptor_tree *desc,
3247 int defer)
3249 rtx symbol = XEXP (desc->rtl, 0);
3250 tree exp = desc->value;
3252 if (flag_syntax_only)
3253 return;
3255 if (TREE_ASM_WRITTEN (exp))
3256 /* Already output; don't do it again. */
3257 return;
3259 /* We can always defer constants as long as the context allows
3260 doing so. */
3261 if (defer)
3263 /* Increment n_deferred_constants if it exists. It needs to be at
3264 least as large as the number of constants actually referred to
3265 by the function. If it's too small we'll stop looking too early
3266 and fail to emit constants; if it's too large we'll only look
3267 through the entire function when we could have stopped earlier. */
3268 if (cfun)
3269 n_deferred_constants++;
3270 return;
3273 output_constant_def_contents (symbol);
3276 /* Subroutine of output_constant_def_contents. Output the definition
3277 of constant EXP, which is pointed to by label LABEL. ALIGN is the
3278 constant's alignment in bits. */
3280 static void
3281 assemble_constant_contents (tree exp, const char *label, unsigned int align)
3283 HOST_WIDE_INT size;
3285 size = get_constant_size (exp);
3287 /* Do any machine/system dependent processing of the constant. */
3288 #ifdef ASM_DECLARE_CONSTANT_NAME
3289 ASM_DECLARE_CONSTANT_NAME (asm_out_file, label, exp, size);
3290 #else
3291 /* Standard thing is just output label for the constant. */
3292 ASM_OUTPUT_LABEL (asm_out_file, label);
3293 #endif /* ASM_DECLARE_CONSTANT_NAME */
3295 /* Output the value of EXP. */
3296 output_constant (exp, size, align);
3299 /* We must output the constant data referred to by SYMBOL; do so. */
3301 static void
3302 output_constant_def_contents (rtx symbol)
3304 tree exp = SYMBOL_REF_DECL (symbol);
3305 unsigned int align;
3307 /* Make sure any other constants whose addresses appear in EXP
3308 are assigned label numbers. */
3309 output_addressed_constants (exp);
3311 /* We are no longer deferring this constant. */
3312 TREE_ASM_WRITTEN (exp) = 1;
3314 /* If the constant is part of an object block, make sure that the
3315 decl has been positioned within its block, but do not write out
3316 its definition yet. output_object_blocks will do that later. */
3317 if (SYMBOL_REF_HAS_BLOCK_INFO_P (symbol) && SYMBOL_REF_BLOCK (symbol))
3318 place_block_symbol (symbol);
3319 else
3321 switch_to_section (get_constant_section (exp));
3322 align = get_constant_alignment (exp);
3323 if (align > BITS_PER_UNIT)
3324 ASM_OUTPUT_ALIGN (asm_out_file, floor_log2 (align / BITS_PER_UNIT));
3325 assemble_constant_contents (exp, XSTR (symbol, 0), align);
3327 if (flag_mudflap)
3328 mudflap_enqueue_constant (exp);
3331 /* Look up EXP in the table of constant descriptors. Return the rtl
3332 if it has been emitted, else null. */
3335 lookup_constant_def (tree exp)
3337 struct constant_descriptor_tree *desc;
3338 struct constant_descriptor_tree key;
3340 key.value = exp;
3341 key.hash = const_hash_1 (exp);
3342 desc = (struct constant_descriptor_tree *)
3343 htab_find_with_hash (const_desc_htab, &key, key.hash);
3345 return (desc ? desc->rtl : NULL_RTX);
3348 /* Used in the hash tables to avoid outputting the same constant
3349 twice. Unlike 'struct constant_descriptor_tree', RTX constants
3350 are output once per function, not once per file. */
3351 /* ??? Only a few targets need per-function constant pools. Most
3352 can use one per-file pool. Should add a targetm bit to tell the
3353 difference. */
3355 struct rtx_constant_pool GTY(())
3357 /* Pointers to first and last constant in pool, as ordered by offset. */
3358 struct constant_descriptor_rtx *first;
3359 struct constant_descriptor_rtx *last;
3361 /* Hash facility for making memory-constants from constant rtl-expressions.
3362 It is used on RISC machines where immediate integer arguments and
3363 constant addresses are restricted so that such constants must be stored
3364 in memory. */
3365 htab_t GTY((param_is (struct constant_descriptor_rtx))) const_rtx_htab;
3367 /* Current offset in constant pool (does not include any
3368 machine-specific header). */
3369 HOST_WIDE_INT offset;
3372 struct constant_descriptor_rtx GTY((chain_next ("%h.next")))
3374 struct constant_descriptor_rtx *next;
3375 rtx mem;
3376 rtx sym;
3377 rtx constant;
3378 HOST_WIDE_INT offset;
3379 hashval_t hash;
3380 enum machine_mode mode;
3381 unsigned int align;
3382 int labelno;
3383 int mark;
3386 /* Hash and compare functions for const_rtx_htab. */
3388 static hashval_t
3389 const_desc_rtx_hash (const void *ptr)
3391 const struct constant_descriptor_rtx *const desc
3392 = (const struct constant_descriptor_rtx *) ptr;
3393 return desc->hash;
3396 static int
3397 const_desc_rtx_eq (const void *a, const void *b)
3399 const struct constant_descriptor_rtx *const x
3400 = (const struct constant_descriptor_rtx *) a;
3401 const struct constant_descriptor_rtx *const y
3402 = (const struct constant_descriptor_rtx *) b;
3404 if (x->mode != y->mode)
3405 return 0;
3406 return rtx_equal_p (x->constant, y->constant);
3409 /* This is the worker function for const_rtx_hash, called via for_each_rtx. */
3411 static int
3412 const_rtx_hash_1 (rtx *xp, void *data)
3414 unsigned HOST_WIDE_INT hwi;
3415 enum machine_mode mode;
3416 enum rtx_code code;
3417 hashval_t h, *hp;
3418 rtx x;
3420 x = *xp;
3421 code = GET_CODE (x);
3422 mode = GET_MODE (x);
3423 h = (hashval_t) code * 1048573 + mode;
3425 switch (code)
3427 case CONST_INT:
3428 hwi = INTVAL (x);
3429 fold_hwi:
3431 const int shift = sizeof (hashval_t) * CHAR_BIT;
3432 const int n = sizeof (HOST_WIDE_INT) / sizeof (hashval_t);
3433 int i;
3435 h ^= (hashval_t) hwi;
3436 for (i = 1; i < n; ++i)
3438 hwi >>= shift;
3439 h ^= (hashval_t) hwi;
3442 break;
3444 case CONST_DOUBLE:
3445 if (mode == VOIDmode)
3447 hwi = CONST_DOUBLE_LOW (x) ^ CONST_DOUBLE_HIGH (x);
3448 goto fold_hwi;
3450 else
3451 h ^= real_hash (CONST_DOUBLE_REAL_VALUE (x));
3452 break;
3454 case CONST_FIXED:
3455 h ^= fixed_hash (CONST_FIXED_VALUE (x));
3456 break;
3458 case CONST_VECTOR:
3460 int i;
3461 for (i = XVECLEN (x, 0); i-- > 0; )
3462 h = h * 251 + const_rtx_hash_1 (&XVECEXP (x, 0, i), data);
3464 break;
3466 case SYMBOL_REF:
3467 h ^= htab_hash_string (XSTR (x, 0));
3468 break;
3470 case LABEL_REF:
3471 h = h * 251 + CODE_LABEL_NUMBER (XEXP (x, 0));
3472 break;
3474 case UNSPEC:
3475 case UNSPEC_VOLATILE:
3476 h = h * 251 + XINT (x, 1);
3477 break;
3479 default:
3480 break;
3483 hp = (hashval_t *) data;
3484 *hp = *hp * 509 + h;
3485 return 0;
3488 /* Compute a hash value for X, which should be a constant. */
3490 static hashval_t
3491 const_rtx_hash (rtx x)
3493 hashval_t h = 0;
3494 for_each_rtx (&x, const_rtx_hash_1, &h);
3495 return h;
3499 /* Create and return a new rtx constant pool. */
3501 static struct rtx_constant_pool *
3502 create_constant_pool (void)
3504 struct rtx_constant_pool *pool;
3506 pool = GGC_NEW (struct rtx_constant_pool);
3507 pool->const_rtx_htab = htab_create_ggc (31, const_desc_rtx_hash,
3508 const_desc_rtx_eq, NULL);
3509 pool->first = NULL;
3510 pool->last = NULL;
3511 pool->offset = 0;
3512 return pool;
3515 /* Initialize constant pool hashing for a new function. */
3517 void
3518 init_varasm_status (void)
3520 crtl->varasm.pool = create_constant_pool ();
3521 crtl->varasm.deferred_constants = 0;
3524 /* Given a MINUS expression, simplify it if both sides
3525 include the same symbol. */
3528 simplify_subtraction (rtx x)
3530 rtx r = simplify_rtx (x);
3531 return r ? r : x;
3534 /* Given a constant rtx X, make (or find) a memory constant for its value
3535 and return a MEM rtx to refer to it in memory. */
3538 force_const_mem (enum machine_mode mode, rtx x)
3540 struct constant_descriptor_rtx *desc, tmp;
3541 struct rtx_constant_pool *pool;
3542 char label[256];
3543 rtx def, symbol;
3544 hashval_t hash;
3545 unsigned int align;
3546 void **slot;
3548 /* If we're not allowed to drop X into the constant pool, don't. */
3549 if (targetm.cannot_force_const_mem (x))
3550 return NULL_RTX;
3552 /* Record that this function has used a constant pool entry. */
3553 crtl->uses_const_pool = 1;
3555 /* Decide which pool to use. */
3556 pool = (targetm.use_blocks_for_constant_p (mode, x)
3557 ? shared_constant_pool
3558 : crtl->varasm.pool);
3560 /* Lookup the value in the hashtable. */
3561 tmp.constant = x;
3562 tmp.mode = mode;
3563 hash = const_rtx_hash (x);
3564 slot = htab_find_slot_with_hash (pool->const_rtx_htab, &tmp, hash, INSERT);
3565 desc = (struct constant_descriptor_rtx *) *slot;
3567 /* If the constant was already present, return its memory. */
3568 if (desc)
3569 return copy_rtx (desc->mem);
3571 /* Otherwise, create a new descriptor. */
3572 desc = GGC_NEW (struct constant_descriptor_rtx);
3573 *slot = desc;
3575 /* Align the location counter as required by EXP's data type. */
3576 align = GET_MODE_ALIGNMENT (mode == VOIDmode ? word_mode : mode);
3577 #ifdef CONSTANT_ALIGNMENT
3579 tree type = lang_hooks.types.type_for_mode (mode, 0);
3580 if (type != NULL_TREE)
3581 align = CONSTANT_ALIGNMENT (make_tree (type, x), align);
3583 #endif
3585 pool->offset += (align / BITS_PER_UNIT) - 1;
3586 pool->offset &= ~ ((align / BITS_PER_UNIT) - 1);
3588 desc->next = NULL;
3589 desc->constant = tmp.constant;
3590 desc->offset = pool->offset;
3591 desc->hash = hash;
3592 desc->mode = mode;
3593 desc->align = align;
3594 desc->labelno = const_labelno;
3595 desc->mark = 0;
3597 pool->offset += GET_MODE_SIZE (mode);
3598 if (pool->last)
3599 pool->last->next = desc;
3600 else
3601 pool->first = pool->last = desc;
3602 pool->last = desc;
3604 /* Create a string containing the label name, in LABEL. */
3605 ASM_GENERATE_INTERNAL_LABEL (label, "LC", const_labelno);
3606 ++const_labelno;
3608 /* Construct the SYMBOL_REF. Make sure to mark it as belonging to
3609 the constants pool. */
3610 if (use_object_blocks_p () && targetm.use_blocks_for_constant_p (mode, x))
3612 section *sect = targetm.asm_out.select_rtx_section (mode, x, align);
3613 symbol = create_block_symbol (ggc_strdup (label),
3614 get_block_for_section (sect), -1);
3616 else
3617 symbol = gen_rtx_SYMBOL_REF (Pmode, ggc_strdup (label));
3618 desc->sym = symbol;
3619 SYMBOL_REF_FLAGS (symbol) |= SYMBOL_FLAG_LOCAL;
3620 CONSTANT_POOL_ADDRESS_P (symbol) = 1;
3621 SET_SYMBOL_REF_CONSTANT (symbol, desc);
3623 /* Construct the MEM. */
3624 desc->mem = def = gen_const_mem (mode, symbol);
3625 set_mem_attributes (def, lang_hooks.types.type_for_mode (mode, 0), 1);
3626 set_mem_align (def, align);
3628 /* If we're dropping a label to the constant pool, make sure we
3629 don't delete it. */
3630 if (GET_CODE (x) == LABEL_REF)
3631 LABEL_PRESERVE_P (XEXP (x, 0)) = 1;
3633 return copy_rtx (def);
3636 /* Given a constant pool SYMBOL_REF, return the corresponding constant. */
3639 get_pool_constant (rtx addr)
3641 return SYMBOL_REF_CONSTANT (addr)->constant;
3644 /* Given a constant pool SYMBOL_REF, return the corresponding constant
3645 and whether it has been output or not. */
3648 get_pool_constant_mark (rtx addr, bool *pmarked)
3650 struct constant_descriptor_rtx *desc;
3652 desc = SYMBOL_REF_CONSTANT (addr);
3653 *pmarked = (desc->mark != 0);
3654 return desc->constant;
3657 /* Similar, return the mode. */
3659 enum machine_mode
3660 get_pool_mode (const_rtx addr)
3662 return SYMBOL_REF_CONSTANT (addr)->mode;
3665 /* Return the size of the constant pool. */
3668 get_pool_size (void)
3670 return crtl->varasm.pool->offset;
3673 /* Worker function for output_constant_pool_1. Emit assembly for X
3674 in MODE with known alignment ALIGN. */
3676 static void
3677 output_constant_pool_2 (enum machine_mode mode, rtx x, unsigned int align)
3679 switch (GET_MODE_CLASS (mode))
3681 case MODE_FLOAT:
3682 case MODE_DECIMAL_FLOAT:
3684 REAL_VALUE_TYPE r;
3686 gcc_assert (GET_CODE (x) == CONST_DOUBLE);
3687 REAL_VALUE_FROM_CONST_DOUBLE (r, x);
3688 assemble_real (r, mode, align);
3689 break;
3692 case MODE_INT:
3693 case MODE_PARTIAL_INT:
3694 case MODE_FRACT:
3695 case MODE_UFRACT:
3696 case MODE_ACCUM:
3697 case MODE_UACCUM:
3698 assemble_integer (x, GET_MODE_SIZE (mode), align, 1);
3699 break;
3701 case MODE_VECTOR_FLOAT:
3702 case MODE_VECTOR_INT:
3703 case MODE_VECTOR_FRACT:
3704 case MODE_VECTOR_UFRACT:
3705 case MODE_VECTOR_ACCUM:
3706 case MODE_VECTOR_UACCUM:
3708 int i, units;
3709 enum machine_mode submode = GET_MODE_INNER (mode);
3710 unsigned int subalign = MIN (align, GET_MODE_BITSIZE (submode));
3712 gcc_assert (GET_CODE (x) == CONST_VECTOR);
3713 units = CONST_VECTOR_NUNITS (x);
3715 for (i = 0; i < units; i++)
3717 rtx elt = CONST_VECTOR_ELT (x, i);
3718 output_constant_pool_2 (submode, elt, i ? subalign : align);
3721 break;
3723 default:
3724 gcc_unreachable ();
3728 /* Worker function for output_constant_pool. Emit constant DESC,
3729 giving it ALIGN bits of alignment. */
3731 static void
3732 output_constant_pool_1 (struct constant_descriptor_rtx *desc,
3733 unsigned int align)
3735 rtx x, tmp;
3737 x = desc->constant;
3739 /* See if X is a LABEL_REF (or a CONST referring to a LABEL_REF)
3740 whose CODE_LABEL has been deleted. This can occur if a jump table
3741 is eliminated by optimization. If so, write a constant of zero
3742 instead. Note that this can also happen by turning the
3743 CODE_LABEL into a NOTE. */
3744 /* ??? This seems completely and utterly wrong. Certainly it's
3745 not true for NOTE_INSN_DELETED_LABEL, but I disbelieve proper
3746 functioning even with INSN_DELETED_P and friends. */
3748 tmp = x;
3749 switch (GET_CODE (tmp))
3751 case CONST:
3752 if (GET_CODE (XEXP (tmp, 0)) != PLUS
3753 || GET_CODE (XEXP (XEXP (tmp, 0), 0)) != LABEL_REF)
3754 break;
3755 tmp = XEXP (XEXP (tmp, 0), 0);
3756 /* FALLTHRU */
3758 case LABEL_REF:
3759 tmp = XEXP (tmp, 0);
3760 gcc_assert (!INSN_DELETED_P (tmp));
3761 gcc_assert (!NOTE_P (tmp)
3762 || NOTE_KIND (tmp) != NOTE_INSN_DELETED);
3763 break;
3765 default:
3766 break;
3769 #ifdef ASM_OUTPUT_SPECIAL_POOL_ENTRY
3770 ASM_OUTPUT_SPECIAL_POOL_ENTRY (asm_out_file, x, desc->mode,
3771 align, desc->labelno, done);
3772 #endif
3774 assemble_align (align);
3776 /* Output the label. */
3777 targetm.asm_out.internal_label (asm_out_file, "LC", desc->labelno);
3779 /* Output the data. */
3780 output_constant_pool_2 (desc->mode, x, align);
3782 /* Make sure all constants in SECTION_MERGE and not SECTION_STRINGS
3783 sections have proper size. */
3784 if (align > GET_MODE_BITSIZE (desc->mode)
3785 && in_section
3786 && (in_section->common.flags & SECTION_MERGE))
3787 assemble_align (align);
3789 #ifdef ASM_OUTPUT_SPECIAL_POOL_ENTRY
3790 done:
3791 #endif
3792 return;
3795 /* Given a SYMBOL_REF CURRENT_RTX, mark it and all constants it refers
3796 to as used. Emit referenced deferred strings. This function can
3797 be used with for_each_rtx to mark all SYMBOL_REFs in an rtx. */
3799 static int
3800 mark_constant (rtx *current_rtx, void *data ATTRIBUTE_UNUSED)
3802 rtx x = *current_rtx;
3804 if (x == NULL_RTX || GET_CODE (x) != SYMBOL_REF)
3805 return 0;
3807 if (CONSTANT_POOL_ADDRESS_P (x))
3809 struct constant_descriptor_rtx *desc = SYMBOL_REF_CONSTANT (x);
3810 if (desc->mark == 0)
3812 desc->mark = 1;
3813 for_each_rtx (&desc->constant, mark_constant, NULL);
3816 else if (TREE_CONSTANT_POOL_ADDRESS_P (x))
3818 tree exp = SYMBOL_REF_DECL (x);
3819 if (!TREE_ASM_WRITTEN (exp))
3821 n_deferred_constants--;
3822 output_constant_def_contents (x);
3826 return -1;
3829 /* Look through appropriate parts of INSN, marking all entries in the
3830 constant pool which are actually being used. Entries that are only
3831 referenced by other constants are also marked as used. Emit
3832 deferred strings that are used. */
3834 static void
3835 mark_constants (rtx insn)
3837 if (!INSN_P (insn))
3838 return;
3840 /* Insns may appear inside a SEQUENCE. Only check the patterns of
3841 insns, not any notes that may be attached. We don't want to mark
3842 a constant just because it happens to appear in a REG_EQUIV note. */
3843 if (GET_CODE (PATTERN (insn)) == SEQUENCE)
3845 rtx seq = PATTERN (insn);
3846 int i, n = XVECLEN (seq, 0);
3847 for (i = 0; i < n; ++i)
3849 rtx subinsn = XVECEXP (seq, 0, i);
3850 if (INSN_P (subinsn))
3851 for_each_rtx (&PATTERN (subinsn), mark_constant, NULL);
3854 else
3855 for_each_rtx (&PATTERN (insn), mark_constant, NULL);
3858 /* Look through the instructions for this function, and mark all the
3859 entries in POOL which are actually being used. Emit deferred constants
3860 which have indeed been used. */
3862 static void
3863 mark_constant_pool (void)
3865 rtx insn, link;
3867 if (!crtl->uses_const_pool && n_deferred_constants == 0)
3868 return;
3870 for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
3871 mark_constants (insn);
3873 for (link = crtl->epilogue_delay_list;
3874 link;
3875 link = XEXP (link, 1))
3876 mark_constants (XEXP (link, 0));
3879 /* Write all the constants in POOL. */
3881 static void
3882 output_constant_pool_contents (struct rtx_constant_pool *pool)
3884 struct constant_descriptor_rtx *desc;
3886 for (desc = pool->first; desc ; desc = desc->next)
3887 if (desc->mark)
3889 /* If the constant is part of an object_block, make sure that
3890 the constant has been positioned within its block, but do not
3891 write out its definition yet. output_object_blocks will do
3892 that later. */
3893 if (SYMBOL_REF_HAS_BLOCK_INFO_P (desc->sym)
3894 && SYMBOL_REF_BLOCK (desc->sym))
3895 place_block_symbol (desc->sym);
3896 else
3898 switch_to_section (targetm.asm_out.select_rtx_section
3899 (desc->mode, desc->constant, desc->align));
3900 output_constant_pool_1 (desc, desc->align);
3905 /* Mark all constants that are used in the current function, then write
3906 out the function's private constant pool. */
3908 static void
3909 output_constant_pool (const char *fnname ATTRIBUTE_UNUSED,
3910 tree fndecl ATTRIBUTE_UNUSED)
3912 struct rtx_constant_pool *pool = crtl->varasm.pool;
3914 /* It is possible for gcc to call force_const_mem and then to later
3915 discard the instructions which refer to the constant. In such a
3916 case we do not need to output the constant. */
3917 mark_constant_pool ();
3919 #ifdef ASM_OUTPUT_POOL_PROLOGUE
3920 ASM_OUTPUT_POOL_PROLOGUE (asm_out_file, fnname, fndecl, pool->offset);
3921 #endif
3923 output_constant_pool_contents (pool);
3925 #ifdef ASM_OUTPUT_POOL_EPILOGUE
3926 ASM_OUTPUT_POOL_EPILOGUE (asm_out_file, fnname, fndecl, pool->offset);
3927 #endif
3930 /* Write the contents of the shared constant pool. */
3932 void
3933 output_shared_constant_pool (void)
3935 output_constant_pool_contents (shared_constant_pool);
3938 /* Determine what kind of relocations EXP may need. */
3941 compute_reloc_for_constant (tree exp)
3943 int reloc = 0, reloc2;
3944 tree tem;
3946 switch (TREE_CODE (exp))
3948 case ADDR_EXPR:
3949 case FDESC_EXPR:
3950 /* Go inside any operations that get_inner_reference can handle and see
3951 if what's inside is a constant: no need to do anything here for
3952 addresses of variables or functions. */
3953 for (tem = TREE_OPERAND (exp, 0); handled_component_p (tem);
3954 tem = TREE_OPERAND (tem, 0))
3957 if (TREE_PUBLIC (tem))
3958 reloc |= 2;
3959 else
3960 reloc |= 1;
3961 break;
3963 case PLUS_EXPR:
3964 case POINTER_PLUS_EXPR:
3965 reloc = compute_reloc_for_constant (TREE_OPERAND (exp, 0));
3966 reloc |= compute_reloc_for_constant (TREE_OPERAND (exp, 1));
3967 break;
3969 case MINUS_EXPR:
3970 reloc = compute_reloc_for_constant (TREE_OPERAND (exp, 0));
3971 reloc2 = compute_reloc_for_constant (TREE_OPERAND (exp, 1));
3972 /* The difference of two local labels is computable at link time. */
3973 if (reloc == 1 && reloc2 == 1)
3974 reloc = 0;
3975 else
3976 reloc |= reloc2;
3977 break;
3979 CASE_CONVERT:
3980 case VIEW_CONVERT_EXPR:
3981 reloc = compute_reloc_for_constant (TREE_OPERAND (exp, 0));
3982 break;
3984 case CONSTRUCTOR:
3986 unsigned HOST_WIDE_INT idx;
3987 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (exp), idx, tem)
3988 if (tem != 0)
3989 reloc |= compute_reloc_for_constant (tem);
3991 break;
3993 default:
3994 break;
3996 return reloc;
3999 /* Find all the constants whose addresses are referenced inside of EXP,
4000 and make sure assembler code with a label has been output for each one.
4001 Indicate whether an ADDR_EXPR has been encountered. */
4003 static void
4004 output_addressed_constants (tree exp)
4006 tree tem;
4008 switch (TREE_CODE (exp))
4010 case ADDR_EXPR:
4011 case FDESC_EXPR:
4012 /* Go inside any operations that get_inner_reference can handle and see
4013 if what's inside is a constant: no need to do anything here for
4014 addresses of variables or functions. */
4015 for (tem = TREE_OPERAND (exp, 0); handled_component_p (tem);
4016 tem = TREE_OPERAND (tem, 0))
4019 /* If we have an initialized CONST_DECL, retrieve the initializer. */
4020 if (TREE_CODE (tem) == CONST_DECL && DECL_INITIAL (tem))
4021 tem = DECL_INITIAL (tem);
4023 if (CONSTANT_CLASS_P (tem) || TREE_CODE (tem) == CONSTRUCTOR)
4024 output_constant_def (tem, 0);
4025 break;
4027 case PLUS_EXPR:
4028 case POINTER_PLUS_EXPR:
4029 case MINUS_EXPR:
4030 output_addressed_constants (TREE_OPERAND (exp, 1));
4031 /* Fall through. */
4033 CASE_CONVERT:
4034 case VIEW_CONVERT_EXPR:
4035 output_addressed_constants (TREE_OPERAND (exp, 0));
4036 break;
4038 case CONSTRUCTOR:
4040 unsigned HOST_WIDE_INT idx;
4041 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (exp), idx, tem)
4042 if (tem != 0)
4043 output_addressed_constants (tem);
4045 break;
4047 default:
4048 break;
4052 /* Whether a constructor CTOR is a valid static constant initializer if all
4053 its elements are. This used to be internal to initializer_constant_valid_p
4054 and has been exposed to let other functions like categorize_ctor_elements
4055 evaluate the property while walking a constructor for other purposes. */
4057 bool
4058 constructor_static_from_elts_p (const_tree ctor)
4060 return (TREE_CONSTANT (ctor)
4061 && (TREE_CODE (TREE_TYPE (ctor)) == UNION_TYPE
4062 || TREE_CODE (TREE_TYPE (ctor)) == RECORD_TYPE)
4063 && !VEC_empty (constructor_elt, CONSTRUCTOR_ELTS (ctor)));
4066 /* A subroutine of initializer_constant_valid_p. VALUE is either a
4067 MINUS_EXPR or a POINTER_PLUS_EXPR. This looks for cases of VALUE
4068 which are valid when ENDTYPE is an integer of any size; in
4069 particular, this does not accept a pointer minus a constant. This
4070 returns null_pointer_node if the VALUE is an absolute constant
4071 which can be used to initialize a static variable. Otherwise it
4072 returns NULL. */
4074 static tree
4075 narrowing_initializer_constant_valid_p (tree value, tree endtype)
4077 tree op0, op1;
4079 if (!INTEGRAL_TYPE_P (endtype))
4080 return NULL_TREE;
4082 op0 = TREE_OPERAND (value, 0);
4083 op1 = TREE_OPERAND (value, 1);
4085 /* Like STRIP_NOPS except allow the operand mode to widen. This
4086 works around a feature of fold that simplifies (int)(p1 - p2) to
4087 ((int)p1 - (int)p2) under the theory that the narrower operation
4088 is cheaper. */
4090 while (CONVERT_EXPR_P (op0)
4091 || TREE_CODE (op0) == NON_LVALUE_EXPR)
4093 tree inner = TREE_OPERAND (op0, 0);
4094 if (inner == error_mark_node
4095 || ! INTEGRAL_MODE_P (TYPE_MODE (TREE_TYPE (inner)))
4096 || (GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op0)))
4097 > GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (inner)))))
4098 break;
4099 op0 = inner;
4102 while (CONVERT_EXPR_P (op1)
4103 || TREE_CODE (op1) == NON_LVALUE_EXPR)
4105 tree inner = TREE_OPERAND (op1, 0);
4106 if (inner == error_mark_node
4107 || ! INTEGRAL_MODE_P (TYPE_MODE (TREE_TYPE (inner)))
4108 || (GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op1)))
4109 > GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (inner)))))
4110 break;
4111 op1 = inner;
4114 op0 = initializer_constant_valid_p (op0, endtype);
4115 op1 = initializer_constant_valid_p (op1, endtype);
4117 /* Both initializers must be known. */
4118 if (op0 && op1)
4120 if (op0 == op1)
4121 return null_pointer_node;
4123 /* Support differences between labels. */
4124 if (TREE_CODE (op0) == LABEL_DECL
4125 && TREE_CODE (op1) == LABEL_DECL)
4126 return null_pointer_node;
4128 if (TREE_CODE (op0) == STRING_CST
4129 && TREE_CODE (op1) == STRING_CST
4130 && operand_equal_p (op0, op1, 1))
4131 return null_pointer_node;
4134 return NULL_TREE;
4137 /* Return nonzero if VALUE is a valid constant-valued expression
4138 for use in initializing a static variable; one that can be an
4139 element of a "constant" initializer.
4141 Return null_pointer_node if the value is absolute;
4142 if it is relocatable, return the variable that determines the relocation.
4143 We assume that VALUE has been folded as much as possible;
4144 therefore, we do not need to check for such things as
4145 arithmetic-combinations of integers. */
4147 tree
4148 initializer_constant_valid_p (tree value, tree endtype)
4150 tree ret;
4152 switch (TREE_CODE (value))
4154 case CONSTRUCTOR:
4155 if (constructor_static_from_elts_p (value))
4157 unsigned HOST_WIDE_INT idx;
4158 tree elt;
4159 bool absolute = true;
4161 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (value), idx, elt)
4163 tree reloc;
4164 reloc = initializer_constant_valid_p (elt, TREE_TYPE (elt));
4165 if (!reloc)
4166 return NULL_TREE;
4167 if (reloc != null_pointer_node)
4168 absolute = false;
4170 /* For a non-absolute relocation, there is no single
4171 variable that can be "the variable that determines the
4172 relocation." */
4173 return absolute ? null_pointer_node : error_mark_node;
4176 return TREE_STATIC (value) ? null_pointer_node : NULL_TREE;
4178 case INTEGER_CST:
4179 case VECTOR_CST:
4180 case REAL_CST:
4181 case FIXED_CST:
4182 case STRING_CST:
4183 case COMPLEX_CST:
4184 return null_pointer_node;
4186 case ADDR_EXPR:
4187 case FDESC_EXPR:
4189 tree op0 = staticp (TREE_OPERAND (value, 0));
4190 if (op0)
4192 /* "&(*a).f" is like unto pointer arithmetic. If "a" turns out
4193 to be a constant, this is old-skool offsetof-like nonsense. */
4194 if (TREE_CODE (op0) == INDIRECT_REF
4195 && TREE_CONSTANT (TREE_OPERAND (op0, 0)))
4196 return null_pointer_node;
4197 /* Taking the address of a nested function involves a trampoline,
4198 unless we don't need or want one. */
4199 if (TREE_CODE (op0) == FUNCTION_DECL
4200 && decl_function_context (op0)
4201 && !DECL_NO_STATIC_CHAIN (op0)
4202 && !TREE_NO_TRAMPOLINE (value))
4203 return NULL_TREE;
4204 /* "&{...}" requires a temporary to hold the constructed
4205 object. */
4206 if (TREE_CODE (op0) == CONSTRUCTOR)
4207 return NULL_TREE;
4209 return op0;
4212 case NON_LVALUE_EXPR:
4213 return initializer_constant_valid_p (TREE_OPERAND (value, 0), endtype);
4215 case VIEW_CONVERT_EXPR:
4217 tree src = TREE_OPERAND (value, 0);
4218 tree src_type = TREE_TYPE (src);
4219 tree dest_type = TREE_TYPE (value);
4221 /* Allow view-conversions from aggregate to non-aggregate type only
4222 if the bit pattern is fully preserved afterwards; otherwise, the
4223 RTL expander won't be able to apply a subsequent transformation
4224 to the underlying constructor. */
4225 if (AGGREGATE_TYPE_P (src_type) && !AGGREGATE_TYPE_P (dest_type))
4227 if (TYPE_MODE (endtype) == TYPE_MODE (dest_type))
4228 return initializer_constant_valid_p (src, endtype);
4229 else
4230 return NULL_TREE;
4233 /* Allow all other kinds of view-conversion. */
4234 return initializer_constant_valid_p (src, endtype);
4237 CASE_CONVERT:
4239 tree src = TREE_OPERAND (value, 0);
4240 tree src_type = TREE_TYPE (src);
4241 tree dest_type = TREE_TYPE (value);
4243 /* Allow conversions between pointer types, floating-point
4244 types, and offset types. */
4245 if ((POINTER_TYPE_P (dest_type) && POINTER_TYPE_P (src_type))
4246 || (FLOAT_TYPE_P (dest_type) && FLOAT_TYPE_P (src_type))
4247 || (TREE_CODE (dest_type) == OFFSET_TYPE
4248 && TREE_CODE (src_type) == OFFSET_TYPE))
4249 return initializer_constant_valid_p (src, endtype);
4251 /* Allow length-preserving conversions between integer types. */
4252 if (INTEGRAL_TYPE_P (dest_type) && INTEGRAL_TYPE_P (src_type)
4253 && (TYPE_PRECISION (dest_type) == TYPE_PRECISION (src_type)))
4254 return initializer_constant_valid_p (src, endtype);
4256 /* Allow conversions between other integer types only if
4257 explicit value. */
4258 if (INTEGRAL_TYPE_P (dest_type) && INTEGRAL_TYPE_P (src_type))
4260 tree inner = initializer_constant_valid_p (src, endtype);
4261 if (inner == null_pointer_node)
4262 return null_pointer_node;
4263 break;
4266 /* Allow (int) &foo provided int is as wide as a pointer. */
4267 if (INTEGRAL_TYPE_P (dest_type) && POINTER_TYPE_P (src_type)
4268 && (TYPE_PRECISION (dest_type) >= TYPE_PRECISION (src_type)))
4269 return initializer_constant_valid_p (src, endtype);
4271 /* Likewise conversions from int to pointers, but also allow
4272 conversions from 0. */
4273 if ((POINTER_TYPE_P (dest_type)
4274 || TREE_CODE (dest_type) == OFFSET_TYPE)
4275 && INTEGRAL_TYPE_P (src_type))
4277 if (TREE_CODE (src) == INTEGER_CST
4278 && TYPE_PRECISION (dest_type) >= TYPE_PRECISION (src_type))
4279 return null_pointer_node;
4280 if (integer_zerop (src))
4281 return null_pointer_node;
4282 else if (TYPE_PRECISION (dest_type) <= TYPE_PRECISION (src_type))
4283 return initializer_constant_valid_p (src, endtype);
4286 /* Allow conversions to struct or union types if the value
4287 inside is okay. */
4288 if (TREE_CODE (dest_type) == RECORD_TYPE
4289 || TREE_CODE (dest_type) == UNION_TYPE)
4290 return initializer_constant_valid_p (src, endtype);
4292 break;
4294 case POINTER_PLUS_EXPR:
4295 case PLUS_EXPR:
4296 if (! INTEGRAL_TYPE_P (endtype)
4297 || TYPE_PRECISION (endtype) >= POINTER_SIZE)
4299 tree valid0 = initializer_constant_valid_p (TREE_OPERAND (value, 0),
4300 endtype);
4301 tree valid1 = initializer_constant_valid_p (TREE_OPERAND (value, 1),
4302 endtype);
4303 /* If either term is absolute, use the other term's relocation. */
4304 if (valid0 == null_pointer_node)
4305 return valid1;
4306 if (valid1 == null_pointer_node)
4307 return valid0;
4310 /* Support narrowing pointer differences. */
4311 if (TREE_CODE (value) == POINTER_PLUS_EXPR)
4313 ret = narrowing_initializer_constant_valid_p (value, endtype);
4314 if (ret != NULL_TREE)
4315 return ret;
4317 break;
4319 case MINUS_EXPR:
4320 if (! INTEGRAL_TYPE_P (endtype)
4321 || TYPE_PRECISION (endtype) >= POINTER_SIZE)
4323 tree valid0 = initializer_constant_valid_p (TREE_OPERAND (value, 0),
4324 endtype);
4325 tree valid1 = initializer_constant_valid_p (TREE_OPERAND (value, 1),
4326 endtype);
4327 /* Win if second argument is absolute. */
4328 if (valid1 == null_pointer_node)
4329 return valid0;
4330 /* Win if both arguments have the same relocation.
4331 Then the value is absolute. */
4332 if (valid0 == valid1 && valid0 != 0)
4333 return null_pointer_node;
4335 /* Since GCC guarantees that string constants are unique in the
4336 generated code, a subtraction between two copies of the same
4337 constant string is absolute. */
4338 if (valid0 && TREE_CODE (valid0) == STRING_CST
4339 && valid1 && TREE_CODE (valid1) == STRING_CST
4340 && operand_equal_p (valid0, valid1, 1))
4341 return null_pointer_node;
4344 /* Support narrowing differences. */
4345 ret = narrowing_initializer_constant_valid_p (value, endtype);
4346 if (ret != NULL_TREE)
4347 return ret;
4349 break;
4351 default:
4352 break;
4355 return 0;
4358 /* Output assembler code for constant EXP to FILE, with no label.
4359 This includes the pseudo-op such as ".int" or ".byte", and a newline.
4360 Assumes output_addressed_constants has been done on EXP already.
4362 Generate exactly SIZE bytes of assembler data, padding at the end
4363 with zeros if necessary. SIZE must always be specified.
4365 SIZE is important for structure constructors,
4366 since trailing members may have been omitted from the constructor.
4367 It is also important for initialization of arrays from string constants
4368 since the full length of the string constant might not be wanted.
4369 It is also needed for initialization of unions, where the initializer's
4370 type is just one member, and that may not be as long as the union.
4372 There a case in which we would fail to output exactly SIZE bytes:
4373 for a structure constructor that wants to produce more than SIZE bytes.
4374 But such constructors will never be generated for any possible input.
4376 ALIGN is the alignment of the data in bits. */
4378 void
4379 output_constant (tree exp, unsigned HOST_WIDE_INT size, unsigned int align)
4381 enum tree_code code;
4382 unsigned HOST_WIDE_INT thissize;
4384 if (size == 0 || flag_syntax_only)
4385 return;
4387 /* See if we're trying to initialize a pointer in a non-default mode
4388 to the address of some declaration somewhere. If the target says
4389 the mode is valid for pointers, assume the target has a way of
4390 resolving it. */
4391 if (TREE_CODE (exp) == NOP_EXPR
4392 && POINTER_TYPE_P (TREE_TYPE (exp))
4393 && targetm.valid_pointer_mode (TYPE_MODE (TREE_TYPE (exp))))
4395 tree saved_type = TREE_TYPE (exp);
4397 /* Peel off any intermediate conversions-to-pointer for valid
4398 pointer modes. */
4399 while (TREE_CODE (exp) == NOP_EXPR
4400 && POINTER_TYPE_P (TREE_TYPE (exp))
4401 && targetm.valid_pointer_mode (TYPE_MODE (TREE_TYPE (exp))))
4402 exp = TREE_OPERAND (exp, 0);
4404 /* If what we're left with is the address of something, we can
4405 convert the address to the final type and output it that
4406 way. */
4407 if (TREE_CODE (exp) == ADDR_EXPR)
4408 exp = build1 (ADDR_EXPR, saved_type, TREE_OPERAND (exp, 0));
4409 /* Likewise for constant ints. */
4410 else if (TREE_CODE (exp) == INTEGER_CST)
4411 exp = build_int_cst_wide (saved_type, TREE_INT_CST_LOW (exp),
4412 TREE_INT_CST_HIGH (exp));
4416 /* Eliminate any conversions since we'll be outputting the underlying
4417 constant. */
4418 while (CONVERT_EXPR_P (exp)
4419 || TREE_CODE (exp) == NON_LVALUE_EXPR
4420 || TREE_CODE (exp) == VIEW_CONVERT_EXPR)
4422 HOST_WIDE_INT type_size = int_size_in_bytes (TREE_TYPE (exp));
4423 HOST_WIDE_INT op_size = int_size_in_bytes (TREE_TYPE (TREE_OPERAND (exp, 0)));
4425 /* Make sure eliminating the conversion is really a no-op, except with
4426 VIEW_CONVERT_EXPRs to allow for wild Ada unchecked conversions and
4427 union types to allow for Ada unchecked unions. */
4428 if (type_size > op_size
4429 && TREE_CODE (exp) != VIEW_CONVERT_EXPR
4430 && TREE_CODE (TREE_TYPE (exp)) != UNION_TYPE)
4431 /* Keep the conversion. */
4432 break;
4433 else
4434 exp = TREE_OPERAND (exp, 0);
4437 code = TREE_CODE (TREE_TYPE (exp));
4438 thissize = int_size_in_bytes (TREE_TYPE (exp));
4440 /* Allow a constructor with no elements for any data type.
4441 This means to fill the space with zeros. */
4442 if (TREE_CODE (exp) == CONSTRUCTOR
4443 && VEC_empty (constructor_elt, CONSTRUCTOR_ELTS (exp)))
4445 assemble_zeros (size);
4446 return;
4449 if (TREE_CODE (exp) == FDESC_EXPR)
4451 #ifdef ASM_OUTPUT_FDESC
4452 HOST_WIDE_INT part = tree_low_cst (TREE_OPERAND (exp, 1), 0);
4453 tree decl = TREE_OPERAND (exp, 0);
4454 ASM_OUTPUT_FDESC (asm_out_file, decl, part);
4455 #else
4456 gcc_unreachable ();
4457 #endif
4458 return;
4461 /* Now output the underlying data. If we've handling the padding, return.
4462 Otherwise, break and ensure SIZE is the size written. */
4463 switch (code)
4465 case BOOLEAN_TYPE:
4466 case INTEGER_TYPE:
4467 case ENUMERAL_TYPE:
4468 case POINTER_TYPE:
4469 case REFERENCE_TYPE:
4470 case OFFSET_TYPE:
4471 case FIXED_POINT_TYPE:
4472 if (! assemble_integer (expand_expr (exp, NULL_RTX, VOIDmode,
4473 EXPAND_INITIALIZER),
4474 MIN (size, thissize), align, 0))
4475 error ("initializer for integer/fixed-point value is too complicated");
4476 break;
4478 case REAL_TYPE:
4479 if (TREE_CODE (exp) != REAL_CST)
4480 error ("initializer for floating value is not a floating constant");
4482 assemble_real (TREE_REAL_CST (exp), TYPE_MODE (TREE_TYPE (exp)), align);
4483 break;
4485 case COMPLEX_TYPE:
4486 output_constant (TREE_REALPART (exp), thissize / 2, align);
4487 output_constant (TREE_IMAGPART (exp), thissize / 2,
4488 min_align (align, BITS_PER_UNIT * (thissize / 2)));
4489 break;
4491 case ARRAY_TYPE:
4492 case VECTOR_TYPE:
4493 switch (TREE_CODE (exp))
4495 case CONSTRUCTOR:
4496 output_constructor (exp, size, align);
4497 return;
4498 case STRING_CST:
4499 thissize = MIN ((unsigned HOST_WIDE_INT)TREE_STRING_LENGTH (exp),
4500 size);
4501 assemble_string (TREE_STRING_POINTER (exp), thissize);
4502 break;
4504 case VECTOR_CST:
4506 int elt_size;
4507 tree link;
4508 unsigned int nalign;
4509 enum machine_mode inner;
4511 inner = TYPE_MODE (TREE_TYPE (TREE_TYPE (exp)));
4512 nalign = MIN (align, GET_MODE_ALIGNMENT (inner));
4514 elt_size = GET_MODE_SIZE (inner);
4516 link = TREE_VECTOR_CST_ELTS (exp);
4517 output_constant (TREE_VALUE (link), elt_size, align);
4518 thissize = elt_size;
4519 while ((link = TREE_CHAIN (link)) != NULL)
4521 output_constant (TREE_VALUE (link), elt_size, nalign);
4522 thissize += elt_size;
4524 break;
4526 default:
4527 gcc_unreachable ();
4529 break;
4531 case RECORD_TYPE:
4532 case UNION_TYPE:
4533 gcc_assert (TREE_CODE (exp) == CONSTRUCTOR);
4534 output_constructor (exp, size, align);
4535 return;
4537 case ERROR_MARK:
4538 return;
4540 default:
4541 gcc_unreachable ();
4544 if (size > thissize)
4545 assemble_zeros (size - thissize);
4549 /* Subroutine of output_constructor, used for computing the size of
4550 arrays of unspecified length. VAL must be a CONSTRUCTOR of an array
4551 type with an unspecified upper bound. */
4553 static unsigned HOST_WIDE_INT
4554 array_size_for_constructor (tree val)
4556 tree max_index, i;
4557 unsigned HOST_WIDE_INT cnt;
4558 tree index, value, tmp;
4560 /* This code used to attempt to handle string constants that are not
4561 arrays of single-bytes, but nothing else does, so there's no point in
4562 doing it here. */
4563 if (TREE_CODE (val) == STRING_CST)
4564 return TREE_STRING_LENGTH (val);
4566 max_index = NULL_TREE;
4567 FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (val), cnt, index, value)
4569 if (TREE_CODE (index) == RANGE_EXPR)
4570 index = TREE_OPERAND (index, 1);
4571 if (max_index == NULL_TREE || tree_int_cst_lt (max_index, index))
4572 max_index = index;
4575 if (max_index == NULL_TREE)
4576 return 0;
4578 /* Compute the total number of array elements. */
4579 tmp = TYPE_MIN_VALUE (TYPE_DOMAIN (TREE_TYPE (val)));
4580 i = size_binop (MINUS_EXPR, fold_convert (sizetype, max_index),
4581 fold_convert (sizetype, tmp));
4582 i = size_binop (PLUS_EXPR, i, build_int_cst (sizetype, 1));
4584 /* Multiply by the array element unit size to find number of bytes. */
4585 i = size_binop (MULT_EXPR, i, TYPE_SIZE_UNIT (TREE_TYPE (TREE_TYPE (val))));
4587 return tree_low_cst (i, 1);
4590 /* Subroutine of output_constant, used for CONSTRUCTORs (aggregate constants).
4591 Generate at least SIZE bytes, padding if necessary. */
4593 static void
4594 output_constructor (tree exp, unsigned HOST_WIDE_INT size,
4595 unsigned int align)
4597 tree type = TREE_TYPE (exp);
4598 tree field = 0;
4599 tree min_index = 0;
4600 /* Number of bytes output or skipped so far.
4601 In other words, current position within the constructor. */
4602 HOST_WIDE_INT total_bytes = 0;
4603 /* Nonzero means BYTE contains part of a byte, to be output. */
4604 int byte_buffer_in_use = 0;
4605 int byte = 0;
4606 unsigned HOST_WIDE_INT cnt;
4607 constructor_elt *ce;
4609 gcc_assert (HOST_BITS_PER_WIDE_INT >= BITS_PER_UNIT);
4611 if (TREE_CODE (type) == RECORD_TYPE)
4612 field = TYPE_FIELDS (type);
4614 if (TREE_CODE (type) == ARRAY_TYPE
4615 && TYPE_DOMAIN (type) != 0)
4616 min_index = TYPE_MIN_VALUE (TYPE_DOMAIN (type));
4618 /* As LINK goes through the elements of the constant,
4619 FIELD goes through the structure fields, if the constant is a structure.
4620 if the constant is a union, then we override this,
4621 by getting the field from the TREE_LIST element.
4622 But the constant could also be an array. Then FIELD is zero.
4624 There is always a maximum of one element in the chain LINK for unions
4625 (even if the initializer in a source program incorrectly contains
4626 more one). */
4627 for (cnt = 0;
4628 VEC_iterate (constructor_elt, CONSTRUCTOR_ELTS (exp), cnt, ce);
4629 cnt++, field = field ? TREE_CHAIN (field) : 0)
4631 tree val = ce->value;
4632 tree index = 0;
4634 /* The element in a union constructor specifies the proper field
4635 or index. */
4636 if ((TREE_CODE (type) == RECORD_TYPE || TREE_CODE (type) == UNION_TYPE
4637 || TREE_CODE (type) == QUAL_UNION_TYPE)
4638 && ce->index != 0)
4639 field = ce->index;
4641 else if (TREE_CODE (type) == ARRAY_TYPE)
4642 index = ce->index;
4644 #ifdef ASM_COMMENT_START
4645 if (field && flag_verbose_asm)
4646 fprintf (asm_out_file, "%s %s:\n",
4647 ASM_COMMENT_START,
4648 DECL_NAME (field)
4649 ? IDENTIFIER_POINTER (DECL_NAME (field))
4650 : "<anonymous>");
4651 #endif
4653 /* Eliminate the marker that makes a cast not be an lvalue. */
4654 if (val != 0)
4655 STRIP_NOPS (val);
4657 if (index && TREE_CODE (index) == RANGE_EXPR)
4659 unsigned HOST_WIDE_INT fieldsize
4660 = int_size_in_bytes (TREE_TYPE (type));
4661 HOST_WIDE_INT lo_index = tree_low_cst (TREE_OPERAND (index, 0), 0);
4662 HOST_WIDE_INT hi_index = tree_low_cst (TREE_OPERAND (index, 1), 0);
4663 HOST_WIDE_INT index;
4664 unsigned int align2 = min_align (align, fieldsize * BITS_PER_UNIT);
4666 for (index = lo_index; index <= hi_index; index++)
4668 /* Output the element's initial value. */
4669 if (val == 0)
4670 assemble_zeros (fieldsize);
4671 else
4672 output_constant (val, fieldsize, align2);
4674 /* Count its size. */
4675 total_bytes += fieldsize;
4678 else if (field == 0 || !DECL_BIT_FIELD (field))
4680 /* An element that is not a bit-field. */
4682 unsigned HOST_WIDE_INT fieldsize;
4683 /* Since this structure is static,
4684 we know the positions are constant. */
4685 HOST_WIDE_INT pos = field ? int_byte_position (field) : 0;
4686 unsigned int align2;
4688 if (index != 0)
4689 pos = (tree_low_cst (TYPE_SIZE_UNIT (TREE_TYPE (val)), 1)
4690 * (tree_low_cst (index, 0) - tree_low_cst (min_index, 0)));
4692 /* Output any buffered-up bit-fields preceding this element. */
4693 if (byte_buffer_in_use)
4695 assemble_integer (GEN_INT (byte), 1, BITS_PER_UNIT, 1);
4696 total_bytes++;
4697 byte_buffer_in_use = 0;
4700 /* Advance to offset of this element.
4701 Note no alignment needed in an array, since that is guaranteed
4702 if each element has the proper size. */
4703 if ((field != 0 || index != 0) && pos != total_bytes)
4705 gcc_assert (pos >= total_bytes);
4706 assemble_zeros (pos - total_bytes);
4707 total_bytes = pos;
4710 /* Find the alignment of this element. */
4711 align2 = min_align (align, BITS_PER_UNIT * pos);
4713 /* Determine size this element should occupy. */
4714 if (field)
4716 fieldsize = 0;
4718 /* If this is an array with an unspecified upper bound,
4719 the initializer determines the size. */
4720 /* ??? This ought to only checked if DECL_SIZE_UNIT is NULL,
4721 but we cannot do this until the deprecated support for
4722 initializing zero-length array members is removed. */
4723 if (TREE_CODE (TREE_TYPE (field)) == ARRAY_TYPE
4724 && TYPE_DOMAIN (TREE_TYPE (field))
4725 && ! TYPE_MAX_VALUE (TYPE_DOMAIN (TREE_TYPE (field))))
4727 fieldsize = array_size_for_constructor (val);
4728 /* Given a non-empty initialization, this field had
4729 better be last. */
4730 gcc_assert (!fieldsize || !TREE_CHAIN (field));
4732 else if (DECL_SIZE_UNIT (field))
4734 /* ??? This can't be right. If the decl size overflows
4735 a host integer we will silently emit no data. */
4736 if (host_integerp (DECL_SIZE_UNIT (field), 1))
4737 fieldsize = tree_low_cst (DECL_SIZE_UNIT (field), 1);
4740 else
4741 fieldsize = int_size_in_bytes (TREE_TYPE (type));
4743 /* Output the element's initial value. */
4744 if (val == 0)
4745 assemble_zeros (fieldsize);
4746 else
4747 output_constant (val, fieldsize, align2);
4749 /* Count its size. */
4750 total_bytes += fieldsize;
4752 else if (val != 0 && TREE_CODE (val) != INTEGER_CST)
4753 error ("invalid initial value for member %qs",
4754 IDENTIFIER_POINTER (DECL_NAME (field)));
4755 else
4757 /* Element that is a bit-field. */
4759 HOST_WIDE_INT next_offset = int_bit_position (field);
4760 HOST_WIDE_INT end_offset
4761 = (next_offset + tree_low_cst (DECL_SIZE (field), 1));
4763 if (val == 0)
4764 val = integer_zero_node;
4766 /* If this field does not start in this (or, next) byte,
4767 skip some bytes. */
4768 if (next_offset / BITS_PER_UNIT != total_bytes)
4770 /* Output remnant of any bit field in previous bytes. */
4771 if (byte_buffer_in_use)
4773 assemble_integer (GEN_INT (byte), 1, BITS_PER_UNIT, 1);
4774 total_bytes++;
4775 byte_buffer_in_use = 0;
4778 /* If still not at proper byte, advance to there. */
4779 if (next_offset / BITS_PER_UNIT != total_bytes)
4781 gcc_assert (next_offset / BITS_PER_UNIT >= total_bytes);
4782 assemble_zeros (next_offset / BITS_PER_UNIT - total_bytes);
4783 total_bytes = next_offset / BITS_PER_UNIT;
4787 if (! byte_buffer_in_use)
4788 byte = 0;
4790 /* We must split the element into pieces that fall within
4791 separate bytes, and combine each byte with previous or
4792 following bit-fields. */
4794 /* next_offset is the offset n fbits from the beginning of
4795 the structure to the next bit of this element to be processed.
4796 end_offset is the offset of the first bit past the end of
4797 this element. */
4798 while (next_offset < end_offset)
4800 int this_time;
4801 int shift;
4802 HOST_WIDE_INT value;
4803 HOST_WIDE_INT next_byte = next_offset / BITS_PER_UNIT;
4804 HOST_WIDE_INT next_bit = next_offset % BITS_PER_UNIT;
4806 /* Advance from byte to byte
4807 within this element when necessary. */
4808 while (next_byte != total_bytes)
4810 assemble_integer (GEN_INT (byte), 1, BITS_PER_UNIT, 1);
4811 total_bytes++;
4812 byte = 0;
4815 /* Number of bits we can process at once
4816 (all part of the same byte). */
4817 this_time = MIN (end_offset - next_offset,
4818 BITS_PER_UNIT - next_bit);
4819 if (BYTES_BIG_ENDIAN)
4821 /* On big-endian machine, take the most significant bits
4822 first (of the bits that are significant)
4823 and put them into bytes from the most significant end. */
4824 shift = end_offset - next_offset - this_time;
4826 /* Don't try to take a bunch of bits that cross
4827 the word boundary in the INTEGER_CST. We can
4828 only select bits from the LOW or HIGH part
4829 not from both. */
4830 if (shift < HOST_BITS_PER_WIDE_INT
4831 && shift + this_time > HOST_BITS_PER_WIDE_INT)
4833 this_time = shift + this_time - HOST_BITS_PER_WIDE_INT;
4834 shift = HOST_BITS_PER_WIDE_INT;
4837 /* Now get the bits from the appropriate constant word. */
4838 if (shift < HOST_BITS_PER_WIDE_INT)
4839 value = TREE_INT_CST_LOW (val);
4840 else
4842 gcc_assert (shift < 2 * HOST_BITS_PER_WIDE_INT);
4843 value = TREE_INT_CST_HIGH (val);
4844 shift -= HOST_BITS_PER_WIDE_INT;
4847 /* Get the result. This works only when:
4848 1 <= this_time <= HOST_BITS_PER_WIDE_INT. */
4849 byte |= (((value >> shift)
4850 & (((HOST_WIDE_INT) 2 << (this_time - 1)) - 1))
4851 << (BITS_PER_UNIT - this_time - next_bit));
4853 else
4855 /* On little-endian machines,
4856 take first the least significant bits of the value
4857 and pack them starting at the least significant
4858 bits of the bytes. */
4859 shift = next_offset - int_bit_position (field);
4861 /* Don't try to take a bunch of bits that cross
4862 the word boundary in the INTEGER_CST. We can
4863 only select bits from the LOW or HIGH part
4864 not from both. */
4865 if (shift < HOST_BITS_PER_WIDE_INT
4866 && shift + this_time > HOST_BITS_PER_WIDE_INT)
4867 this_time = (HOST_BITS_PER_WIDE_INT - shift);
4869 /* Now get the bits from the appropriate constant word. */
4870 if (shift < HOST_BITS_PER_WIDE_INT)
4871 value = TREE_INT_CST_LOW (val);
4872 else
4874 gcc_assert (shift < 2 * HOST_BITS_PER_WIDE_INT);
4875 value = TREE_INT_CST_HIGH (val);
4876 shift -= HOST_BITS_PER_WIDE_INT;
4879 /* Get the result. This works only when:
4880 1 <= this_time <= HOST_BITS_PER_WIDE_INT. */
4881 byte |= (((value >> shift)
4882 & (((HOST_WIDE_INT) 2 << (this_time - 1)) - 1))
4883 << next_bit);
4886 next_offset += this_time;
4887 byte_buffer_in_use = 1;
4892 if (byte_buffer_in_use)
4894 assemble_integer (GEN_INT (byte), 1, BITS_PER_UNIT, 1);
4895 total_bytes++;
4898 if ((unsigned HOST_WIDE_INT)total_bytes < size)
4899 assemble_zeros (size - total_bytes);
4902 /* Mark DECL as weak. */
4904 static void
4905 mark_weak (tree decl)
4907 DECL_WEAK (decl) = 1;
4909 if (DECL_RTL_SET_P (decl)
4910 && MEM_P (DECL_RTL (decl))
4911 && XEXP (DECL_RTL (decl), 0)
4912 && GET_CODE (XEXP (DECL_RTL (decl), 0)) == SYMBOL_REF)
4913 SYMBOL_REF_WEAK (XEXP (DECL_RTL (decl), 0)) = 1;
4916 /* Merge weak status between NEWDECL and OLDDECL. */
4918 void
4919 merge_weak (tree newdecl, tree olddecl)
4921 if (DECL_WEAK (newdecl) == DECL_WEAK (olddecl))
4923 if (DECL_WEAK (newdecl) && SUPPORTS_WEAK)
4925 tree *pwd;
4926 /* We put the NEWDECL on the weak_decls list at some point
4927 and OLDDECL as well. Keep just OLDDECL on the list. */
4928 for (pwd = &weak_decls; *pwd; pwd = &TREE_CHAIN (*pwd))
4929 if (TREE_VALUE (*pwd) == newdecl)
4931 *pwd = TREE_CHAIN (*pwd);
4932 break;
4935 return;
4938 if (DECL_WEAK (newdecl))
4940 tree wd;
4942 /* NEWDECL is weak, but OLDDECL is not. */
4944 /* If we already output the OLDDECL, we're in trouble; we can't
4945 go back and make it weak. This error cannot be caught in
4946 declare_weak because the NEWDECL and OLDDECL was not yet
4947 been merged; therefore, TREE_ASM_WRITTEN was not set. */
4948 if (TREE_ASM_WRITTEN (olddecl))
4949 error ("weak declaration of %q+D must precede definition",
4950 newdecl);
4952 /* If we've already generated rtl referencing OLDDECL, we may
4953 have done so in a way that will not function properly with
4954 a weak symbol. */
4955 else if (TREE_USED (olddecl)
4956 && TREE_SYMBOL_REFERENCED (DECL_ASSEMBLER_NAME (olddecl)))
4957 warning (0, "weak declaration of %q+D after first use results "
4958 "in unspecified behavior", newdecl);
4960 if (SUPPORTS_WEAK)
4962 /* We put the NEWDECL on the weak_decls list at some point.
4963 Replace it with the OLDDECL. */
4964 for (wd = weak_decls; wd; wd = TREE_CHAIN (wd))
4965 if (TREE_VALUE (wd) == newdecl)
4967 TREE_VALUE (wd) = olddecl;
4968 break;
4970 /* We may not find the entry on the list. If NEWDECL is a
4971 weak alias, then we will have already called
4972 globalize_decl to remove the entry; in that case, we do
4973 not need to do anything. */
4976 /* Make the OLDDECL weak; it's OLDDECL that we'll be keeping. */
4977 mark_weak (olddecl);
4979 else
4980 /* OLDDECL was weak, but NEWDECL was not explicitly marked as
4981 weak. Just update NEWDECL to indicate that it's weak too. */
4982 mark_weak (newdecl);
4985 /* Declare DECL to be a weak symbol. */
4987 void
4988 declare_weak (tree decl)
4990 if (! TREE_PUBLIC (decl))
4991 error ("weak declaration of %q+D must be public", decl);
4992 else if (TREE_CODE (decl) == FUNCTION_DECL && TREE_ASM_WRITTEN (decl))
4993 error ("weak declaration of %q+D must precede definition", decl);
4994 else if (!SUPPORTS_WEAK)
4995 warning (0, "weak declaration of %q+D not supported", decl);
4997 mark_weak (decl);
5000 static void
5001 weak_finish_1 (tree decl)
5003 #if defined (ASM_WEAKEN_DECL) || defined (ASM_WEAKEN_LABEL)
5004 const char *const name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
5005 #endif
5007 if (! TREE_USED (decl))
5008 return;
5010 #ifdef ASM_WEAKEN_DECL
5011 ASM_WEAKEN_DECL (asm_out_file, decl, name, NULL);
5012 #else
5013 #ifdef ASM_WEAKEN_LABEL
5014 ASM_WEAKEN_LABEL (asm_out_file, name);
5015 #else
5016 #ifdef ASM_OUTPUT_WEAK_ALIAS
5018 static bool warn_once = 0;
5019 if (! warn_once)
5021 warning (0, "only weak aliases are supported in this configuration");
5022 warn_once = 1;
5024 return;
5026 #endif
5027 #endif
5028 #endif
5031 /* This TREE_LIST contains weakref targets. */
5033 static GTY(()) tree weakref_targets;
5035 /* Forward declaration. */
5036 static tree find_decl_and_mark_needed (tree decl, tree target);
5038 /* Emit any pending weak declarations. */
5040 void
5041 weak_finish (void)
5043 tree t;
5045 for (t = weakref_targets; t; t = TREE_CHAIN (t))
5047 tree alias_decl = TREE_PURPOSE (t);
5048 tree target = ultimate_transparent_alias_target (&TREE_VALUE (t));
5050 if (! TREE_SYMBOL_REFERENCED (DECL_ASSEMBLER_NAME (alias_decl)))
5051 /* Remove alias_decl from the weak list, but leave entries for
5052 the target alone. */
5053 target = NULL_TREE;
5054 #ifndef ASM_OUTPUT_WEAKREF
5055 else if (! TREE_SYMBOL_REFERENCED (target))
5057 /* Use ASM_WEAKEN_LABEL only if ASM_WEAKEN_DECL is not
5058 defined, otherwise we and weak_finish_1 would use
5059 different macros. */
5060 # if defined ASM_WEAKEN_LABEL && ! defined ASM_WEAKEN_DECL
5061 ASM_WEAKEN_LABEL (asm_out_file, IDENTIFIER_POINTER (target));
5062 # else
5063 tree decl = find_decl_and_mark_needed (alias_decl, target);
5065 if (! decl)
5067 decl = build_decl (TREE_CODE (alias_decl), target,
5068 TREE_TYPE (alias_decl));
5070 DECL_EXTERNAL (decl) = 1;
5071 TREE_PUBLIC (decl) = 1;
5072 DECL_ARTIFICIAL (decl) = 1;
5073 TREE_NOTHROW (decl) = TREE_NOTHROW (alias_decl);
5074 TREE_USED (decl) = 1;
5077 weak_finish_1 (decl);
5078 # endif
5080 #endif
5083 tree *p;
5084 tree t2;
5086 /* Remove the alias and the target from the pending weak list
5087 so that we do not emit any .weak directives for the former,
5088 nor multiple .weak directives for the latter. */
5089 for (p = &weak_decls; (t2 = *p) ; )
5091 if (TREE_VALUE (t2) == alias_decl
5092 || target == DECL_ASSEMBLER_NAME (TREE_VALUE (t2)))
5093 *p = TREE_CHAIN (t2);
5094 else
5095 p = &TREE_CHAIN (t2);
5098 /* Remove other weakrefs to the same target, to speed things up. */
5099 for (p = &TREE_CHAIN (t); (t2 = *p) ; )
5101 if (target == ultimate_transparent_alias_target (&TREE_VALUE (t2)))
5102 *p = TREE_CHAIN (t2);
5103 else
5104 p = &TREE_CHAIN (t2);
5109 for (t = weak_decls; t; t = TREE_CHAIN (t))
5111 tree decl = TREE_VALUE (t);
5113 weak_finish_1 (decl);
5117 /* Emit the assembly bits to indicate that DECL is globally visible. */
5119 static void
5120 globalize_decl (tree decl)
5123 #if defined (ASM_WEAKEN_LABEL) || defined (ASM_WEAKEN_DECL)
5124 if (DECL_WEAK (decl))
5126 const char *name = XSTR (XEXP (DECL_RTL (decl), 0), 0);
5127 tree *p, t;
5129 #ifdef ASM_WEAKEN_DECL
5130 ASM_WEAKEN_DECL (asm_out_file, decl, name, 0);
5131 #else
5132 ASM_WEAKEN_LABEL (asm_out_file, name);
5133 #endif
5135 /* Remove this function from the pending weak list so that
5136 we do not emit multiple .weak directives for it. */
5137 for (p = &weak_decls; (t = *p) ; )
5139 if (DECL_ASSEMBLER_NAME (decl) == DECL_ASSEMBLER_NAME (TREE_VALUE (t)))
5140 *p = TREE_CHAIN (t);
5141 else
5142 p = &TREE_CHAIN (t);
5145 /* Remove weakrefs to the same target from the pending weakref
5146 list, for the same reason. */
5147 for (p = &weakref_targets; (t = *p) ; )
5149 if (DECL_ASSEMBLER_NAME (decl)
5150 == ultimate_transparent_alias_target (&TREE_VALUE (t)))
5151 *p = TREE_CHAIN (t);
5152 else
5153 p = &TREE_CHAIN (t);
5156 return;
5158 #endif
5160 targetm.asm_out.globalize_decl_name (asm_out_file, decl);
5163 /* We have to be able to tell cgraph about the needed-ness of the target
5164 of an alias. This requires that the decl have been defined. Aliases
5165 that precede their definition have to be queued for later processing. */
5167 typedef struct alias_pair GTY(())
5169 tree decl;
5170 tree target;
5171 } alias_pair;
5173 /* Define gc'd vector type. */
5174 DEF_VEC_O(alias_pair);
5175 DEF_VEC_ALLOC_O(alias_pair,gc);
5177 static GTY(()) VEC(alias_pair,gc) *alias_pairs;
5179 /* Given an assembly name, find the decl it is associated with. At the
5180 same time, mark it needed for cgraph. */
5182 static tree
5183 find_decl_and_mark_needed (tree decl, tree target)
5185 struct cgraph_node *fnode = NULL;
5186 struct varpool_node *vnode = NULL;
5188 if (TREE_CODE (decl) == FUNCTION_DECL)
5190 fnode = cgraph_node_for_asm (target);
5191 if (fnode == NULL)
5192 vnode = varpool_node_for_asm (target);
5194 else
5196 vnode = varpool_node_for_asm (target);
5197 if (vnode == NULL)
5198 fnode = cgraph_node_for_asm (target);
5201 if (fnode)
5203 /* We can't mark function nodes as used after cgraph global info
5204 is finished. This wouldn't generally be necessary, but C++
5205 virtual table thunks are introduced late in the game and
5206 might seem like they need marking, although in fact they
5207 don't. */
5208 if (! cgraph_global_info_ready)
5209 cgraph_mark_needed_node (fnode);
5210 return fnode->decl;
5212 else if (vnode)
5214 varpool_mark_needed_node (vnode);
5215 return vnode->decl;
5217 else
5218 return NULL_TREE;
5221 /* Output the assembler code for a define (equate) using ASM_OUTPUT_DEF
5222 or ASM_OUTPUT_DEF_FROM_DECLS. The function defines the symbol whose
5223 tree node is DECL to have the value of the tree node TARGET. */
5225 static void
5226 do_assemble_alias (tree decl, tree target)
5228 if (TREE_ASM_WRITTEN (decl))
5229 return;
5231 TREE_ASM_WRITTEN (decl) = 1;
5232 TREE_ASM_WRITTEN (DECL_ASSEMBLER_NAME (decl)) = 1;
5234 if (lookup_attribute ("weakref", DECL_ATTRIBUTES (decl)))
5236 ultimate_transparent_alias_target (&target);
5238 if (!targetm.have_tls
5239 && TREE_CODE (decl) == VAR_DECL
5240 && DECL_THREAD_LOCAL_P (decl))
5242 decl = emutls_decl (decl);
5243 target = get_emutls_object_name (target);
5246 if (!TREE_SYMBOL_REFERENCED (target))
5247 weakref_targets = tree_cons (decl, target, weakref_targets);
5249 #ifdef ASM_OUTPUT_WEAKREF
5250 ASM_OUTPUT_WEAKREF (asm_out_file, decl,
5251 IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl)),
5252 IDENTIFIER_POINTER (target));
5253 #else
5254 if (!SUPPORTS_WEAK)
5256 error ("%Jweakref is not supported in this configuration", decl);
5257 return;
5259 #endif
5260 return;
5263 if (!targetm.have_tls
5264 && TREE_CODE (decl) == VAR_DECL
5265 && DECL_THREAD_LOCAL_P (decl))
5267 decl = emutls_decl (decl);
5268 target = get_emutls_object_name (target);
5271 #ifdef ASM_OUTPUT_DEF
5272 /* Make name accessible from other files, if appropriate. */
5274 if (TREE_PUBLIC (decl))
5276 globalize_decl (decl);
5277 maybe_assemble_visibility (decl);
5280 # ifdef ASM_OUTPUT_DEF_FROM_DECLS
5281 ASM_OUTPUT_DEF_FROM_DECLS (asm_out_file, decl, target);
5282 # else
5283 ASM_OUTPUT_DEF (asm_out_file,
5284 IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl)),
5285 IDENTIFIER_POINTER (target));
5286 # endif
5287 #elif defined (ASM_OUTPUT_WEAK_ALIAS) || defined (ASM_WEAKEN_DECL)
5289 const char *name;
5290 tree *p, t;
5292 name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
5293 # ifdef ASM_WEAKEN_DECL
5294 ASM_WEAKEN_DECL (asm_out_file, decl, name, IDENTIFIER_POINTER (target));
5295 # else
5296 ASM_OUTPUT_WEAK_ALIAS (asm_out_file, name, IDENTIFIER_POINTER (target));
5297 # endif
5298 /* Remove this function from the pending weak list so that
5299 we do not emit multiple .weak directives for it. */
5300 for (p = &weak_decls; (t = *p) ; )
5301 if (DECL_ASSEMBLER_NAME (decl) == DECL_ASSEMBLER_NAME (TREE_VALUE (t)))
5302 *p = TREE_CHAIN (t);
5303 else
5304 p = &TREE_CHAIN (t);
5306 /* Remove weakrefs to the same target from the pending weakref
5307 list, for the same reason. */
5308 for (p = &weakref_targets; (t = *p) ; )
5310 if (DECL_ASSEMBLER_NAME (decl)
5311 == ultimate_transparent_alias_target (&TREE_VALUE (t)))
5312 *p = TREE_CHAIN (t);
5313 else
5314 p = &TREE_CHAIN (t);
5317 #endif
5320 /* First pass of completing pending aliases. Make sure that cgraph knows
5321 which symbols will be required. */
5323 void
5324 finish_aliases_1 (void)
5326 unsigned i;
5327 alias_pair *p;
5329 for (i = 0; VEC_iterate (alias_pair, alias_pairs, i, p); i++)
5331 tree target_decl;
5333 target_decl = find_decl_and_mark_needed (p->decl, p->target);
5334 if (target_decl == NULL)
5336 if (! lookup_attribute ("weakref", DECL_ATTRIBUTES (p->decl)))
5337 error ("%q+D aliased to undefined symbol %qs",
5338 p->decl, IDENTIFIER_POINTER (p->target));
5340 else if (DECL_EXTERNAL (target_decl)
5341 && ! lookup_attribute ("weakref", DECL_ATTRIBUTES (p->decl)))
5342 error ("%q+D aliased to external symbol %qs",
5343 p->decl, IDENTIFIER_POINTER (p->target));
5347 /* Second pass of completing pending aliases. Emit the actual assembly.
5348 This happens at the end of compilation and thus it is assured that the
5349 target symbol has been emitted. */
5351 void
5352 finish_aliases_2 (void)
5354 unsigned i;
5355 alias_pair *p;
5357 for (i = 0; VEC_iterate (alias_pair, alias_pairs, i, p); i++)
5358 do_assemble_alias (p->decl, p->target);
5360 VEC_truncate (alias_pair, alias_pairs, 0);
5363 /* Emit an assembler directive to make the symbol for DECL an alias to
5364 the symbol for TARGET. */
5366 void
5367 assemble_alias (tree decl, tree target)
5369 tree target_decl;
5370 bool is_weakref = false;
5372 if (lookup_attribute ("weakref", DECL_ATTRIBUTES (decl)))
5374 tree alias = DECL_ASSEMBLER_NAME (decl);
5376 is_weakref = true;
5378 ultimate_transparent_alias_target (&target);
5380 if (alias == target)
5381 error ("weakref %q+D ultimately targets itself", decl);
5382 else
5384 #ifndef ASM_OUTPUT_WEAKREF
5385 IDENTIFIER_TRANSPARENT_ALIAS (alias) = 1;
5386 TREE_CHAIN (alias) = target;
5387 #endif
5389 if (TREE_PUBLIC (decl))
5390 error ("weakref %q+D must have static linkage", decl);
5392 else
5394 #if !defined (ASM_OUTPUT_DEF)
5395 # if !defined(ASM_OUTPUT_WEAK_ALIAS) && !defined (ASM_WEAKEN_DECL)
5396 error ("%Jalias definitions not supported in this configuration", decl);
5397 return;
5398 # else
5399 if (!DECL_WEAK (decl))
5401 error ("%Jonly weak aliases are supported in this configuration", decl);
5402 return;
5404 # endif
5405 #endif
5408 /* We must force creation of DECL_RTL for debug info generation, even though
5409 we don't use it here. */
5410 make_decl_rtl (decl);
5411 TREE_USED (decl) = 1;
5413 /* A quirk of the initial implementation of aliases required that the user
5414 add "extern" to all of them. Which is silly, but now historical. Do
5415 note that the symbol is in fact locally defined. */
5416 if (! is_weakref)
5417 DECL_EXTERNAL (decl) = 0;
5419 /* Allow aliases to aliases. */
5420 if (TREE_CODE (decl) == FUNCTION_DECL)
5421 cgraph_node (decl)->alias = true;
5422 else
5423 varpool_node (decl)->alias = true;
5425 /* If the target has already been emitted, we don't have to queue the
5426 alias. This saves a tad of memory. */
5427 if (cgraph_global_info_ready)
5428 target_decl = find_decl_and_mark_needed (decl, target);
5429 else
5430 target_decl= NULL;
5431 if (target_decl && TREE_ASM_WRITTEN (target_decl))
5432 do_assemble_alias (decl, target);
5433 else
5435 alias_pair *p = VEC_safe_push (alias_pair, gc, alias_pairs, NULL);
5436 p->decl = decl;
5437 p->target = target;
5441 /* Emit an assembler directive to set symbol for DECL visibility to
5442 the visibility type VIS, which must not be VISIBILITY_DEFAULT. */
5444 void
5445 default_assemble_visibility (tree decl, int vis)
5447 static const char * const visibility_types[] = {
5448 NULL, "protected", "hidden", "internal"
5451 const char *name, *type;
5453 name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
5454 type = visibility_types[vis];
5456 #ifdef HAVE_GAS_HIDDEN
5457 fprintf (asm_out_file, "\t.%s\t", type);
5458 assemble_name (asm_out_file, name);
5459 fprintf (asm_out_file, "\n");
5460 #else
5461 warning (OPT_Wattributes, "visibility attribute not supported "
5462 "in this configuration; ignored");
5463 #endif
5466 /* A helper function to call assemble_visibility when needed for a decl. */
5469 maybe_assemble_visibility (tree decl)
5471 enum symbol_visibility vis = DECL_VISIBILITY (decl);
5473 if (vis != VISIBILITY_DEFAULT)
5475 targetm.asm_out.visibility (decl, vis);
5476 return 1;
5478 else
5479 return 0;
5482 /* Returns 1 if the target configuration supports defining public symbols
5483 so that one of them will be chosen at link time instead of generating a
5484 multiply-defined symbol error, whether through the use of weak symbols or
5485 a target-specific mechanism for having duplicates discarded. */
5488 supports_one_only (void)
5490 if (SUPPORTS_ONE_ONLY)
5491 return 1;
5492 return SUPPORTS_WEAK;
5495 /* Set up DECL as a public symbol that can be defined in multiple
5496 translation units without generating a linker error. */
5498 void
5499 make_decl_one_only (tree decl)
5501 gcc_assert (TREE_CODE (decl) == VAR_DECL
5502 || TREE_CODE (decl) == FUNCTION_DECL);
5504 TREE_PUBLIC (decl) = 1;
5506 if (SUPPORTS_ONE_ONLY)
5508 #ifdef MAKE_DECL_ONE_ONLY
5509 MAKE_DECL_ONE_ONLY (decl);
5510 #endif
5511 DECL_ONE_ONLY (decl) = 1;
5513 else if (TREE_CODE (decl) == VAR_DECL
5514 && (DECL_INITIAL (decl) == 0 || DECL_INITIAL (decl) == error_mark_node))
5515 DECL_COMMON (decl) = 1;
5516 else
5518 gcc_assert (SUPPORTS_WEAK);
5519 DECL_WEAK (decl) = 1;
5523 void
5524 init_varasm_once (void)
5526 section_htab = htab_create_ggc (31, section_entry_hash,
5527 section_entry_eq, NULL);
5528 object_block_htab = htab_create_ggc (31, object_block_entry_hash,
5529 object_block_entry_eq, NULL);
5530 const_desc_htab = htab_create_ggc (1009, const_desc_hash,
5531 const_desc_eq, NULL);
5533 const_alias_set = new_alias_set ();
5534 shared_constant_pool = create_constant_pool ();
5536 #ifdef TEXT_SECTION_ASM_OP
5537 text_section = get_unnamed_section (SECTION_CODE, output_section_asm_op,
5538 TEXT_SECTION_ASM_OP);
5539 #endif
5541 #ifdef DATA_SECTION_ASM_OP
5542 data_section = get_unnamed_section (SECTION_WRITE, output_section_asm_op,
5543 DATA_SECTION_ASM_OP);
5544 #endif
5546 #ifdef SDATA_SECTION_ASM_OP
5547 sdata_section = get_unnamed_section (SECTION_WRITE, output_section_asm_op,
5548 SDATA_SECTION_ASM_OP);
5549 #endif
5551 #ifdef READONLY_DATA_SECTION_ASM_OP
5552 readonly_data_section = get_unnamed_section (0, output_section_asm_op,
5553 READONLY_DATA_SECTION_ASM_OP);
5554 #endif
5556 #ifdef CTORS_SECTION_ASM_OP
5557 ctors_section = get_unnamed_section (0, output_section_asm_op,
5558 CTORS_SECTION_ASM_OP);
5559 #endif
5561 #ifdef DTORS_SECTION_ASM_OP
5562 dtors_section = get_unnamed_section (0, output_section_asm_op,
5563 DTORS_SECTION_ASM_OP);
5564 #endif
5566 #ifdef BSS_SECTION_ASM_OP
5567 bss_section = get_unnamed_section (SECTION_WRITE | SECTION_BSS,
5568 output_section_asm_op,
5569 BSS_SECTION_ASM_OP);
5570 #endif
5572 #ifdef SBSS_SECTION_ASM_OP
5573 sbss_section = get_unnamed_section (SECTION_WRITE | SECTION_BSS,
5574 output_section_asm_op,
5575 SBSS_SECTION_ASM_OP);
5576 #endif
5578 tls_comm_section = get_noswitch_section (SECTION_WRITE | SECTION_BSS
5579 | SECTION_COMMON, emit_tls_common);
5580 lcomm_section = get_noswitch_section (SECTION_WRITE | SECTION_BSS
5581 | SECTION_COMMON, emit_local);
5582 comm_section = get_noswitch_section (SECTION_WRITE | SECTION_BSS
5583 | SECTION_COMMON, emit_common);
5585 #if defined ASM_OUTPUT_ALIGNED_BSS || defined ASM_OUTPUT_BSS
5586 bss_noswitch_section = get_noswitch_section (SECTION_WRITE | SECTION_BSS,
5587 emit_bss);
5588 #endif
5590 targetm.asm_out.init_sections ();
5592 if (readonly_data_section == NULL)
5593 readonly_data_section = text_section;
5596 enum tls_model
5597 decl_default_tls_model (const_tree decl)
5599 enum tls_model kind;
5600 bool is_local;
5602 is_local = targetm.binds_local_p (decl);
5603 if (!flag_shlib)
5605 if (is_local)
5606 kind = TLS_MODEL_LOCAL_EXEC;
5607 else
5608 kind = TLS_MODEL_INITIAL_EXEC;
5611 /* Local dynamic is inefficient when we're not combining the
5612 parts of the address. */
5613 else if (optimize && is_local)
5614 kind = TLS_MODEL_LOCAL_DYNAMIC;
5615 else
5616 kind = TLS_MODEL_GLOBAL_DYNAMIC;
5617 if (kind < flag_tls_default)
5618 kind = flag_tls_default;
5620 return kind;
5623 /* Select a set of attributes for section NAME based on the properties
5624 of DECL and whether or not RELOC indicates that DECL's initializer
5625 might contain runtime relocations.
5627 We make the section read-only and executable for a function decl,
5628 read-only for a const data decl, and writable for a non-const data decl. */
5630 unsigned int
5631 default_section_type_flags (tree decl, const char *name, int reloc)
5633 unsigned int flags;
5635 if (decl && TREE_CODE (decl) == FUNCTION_DECL)
5636 flags = SECTION_CODE;
5637 else if (decl && decl_readonly_section (decl, reloc))
5638 flags = 0;
5639 else if (current_function_decl
5640 && cfun
5641 && crtl->subsections.unlikely_text_section_name
5642 && strcmp (name, crtl->subsections.unlikely_text_section_name) == 0)
5643 flags = SECTION_CODE;
5644 else if (!decl
5645 && (!current_function_decl || !cfun)
5646 && strcmp (name, UNLIKELY_EXECUTED_TEXT_SECTION_NAME) == 0)
5647 flags = SECTION_CODE;
5648 else
5649 flags = SECTION_WRITE;
5651 if (decl && DECL_ONE_ONLY (decl))
5652 flags |= SECTION_LINKONCE;
5654 if (decl && TREE_CODE (decl) == VAR_DECL && DECL_THREAD_LOCAL_P (decl))
5655 flags |= SECTION_TLS | SECTION_WRITE;
5657 if (strcmp (name, ".bss") == 0
5658 || strncmp (name, ".bss.", 5) == 0
5659 || strncmp (name, ".gnu.linkonce.b.", 16) == 0
5660 || strcmp (name, ".sbss") == 0
5661 || strncmp (name, ".sbss.", 6) == 0
5662 || strncmp (name, ".gnu.linkonce.sb.", 17) == 0)
5663 flags |= SECTION_BSS;
5665 if (strcmp (name, ".tdata") == 0
5666 || strncmp (name, ".tdata.", 7) == 0
5667 || strncmp (name, ".gnu.linkonce.td.", 17) == 0)
5668 flags |= SECTION_TLS;
5670 if (strcmp (name, ".tbss") == 0
5671 || strncmp (name, ".tbss.", 6) == 0
5672 || strncmp (name, ".gnu.linkonce.tb.", 17) == 0)
5673 flags |= SECTION_TLS | SECTION_BSS;
5675 /* These three sections have special ELF types. They are neither
5676 SHT_PROGBITS nor SHT_NOBITS, so when changing sections we don't
5677 want to print a section type (@progbits or @nobits). If someone
5678 is silly enough to emit code or TLS variables to one of these
5679 sections, then don't handle them specially. */
5680 if (!(flags & (SECTION_CODE | SECTION_BSS | SECTION_TLS))
5681 && (strcmp (name, ".init_array") == 0
5682 || strcmp (name, ".fini_array") == 0
5683 || strcmp (name, ".preinit_array") == 0))
5684 flags |= SECTION_NOTYPE;
5686 return flags;
5689 /* Return true if the target supports some form of global BSS,
5690 either through bss_noswitch_section, or by selecting a BSS
5691 section in TARGET_ASM_SELECT_SECTION. */
5693 bool
5694 have_global_bss_p (void)
5696 return bss_noswitch_section || targetm.have_switchable_bss_sections;
5699 /* Output assembly to switch to section NAME with attribute FLAGS.
5700 Four variants for common object file formats. */
5702 void
5703 default_no_named_section (const char *name ATTRIBUTE_UNUSED,
5704 unsigned int flags ATTRIBUTE_UNUSED,
5705 tree decl ATTRIBUTE_UNUSED)
5707 /* Some object formats don't support named sections at all. The
5708 front-end should already have flagged this as an error. */
5709 gcc_unreachable ();
5712 void
5713 default_elf_asm_named_section (const char *name, unsigned int flags,
5714 tree decl ATTRIBUTE_UNUSED)
5716 char flagchars[10], *f = flagchars;
5718 /* If we have already declared this section, we can use an
5719 abbreviated form to switch back to it -- unless this section is
5720 part of a COMDAT groups, in which case GAS requires the full
5721 declaration every time. */
5722 if (!(HAVE_COMDAT_GROUP && (flags & SECTION_LINKONCE))
5723 && (flags & SECTION_DECLARED))
5725 fprintf (asm_out_file, "\t.section\t%s\n", name);
5726 return;
5729 if (!(flags & SECTION_DEBUG))
5730 *f++ = 'a';
5731 if (flags & SECTION_WRITE)
5732 *f++ = 'w';
5733 if (flags & SECTION_CODE)
5734 *f++ = 'x';
5735 if (flags & SECTION_SMALL)
5736 *f++ = 's';
5737 if (flags & SECTION_MERGE)
5738 *f++ = 'M';
5739 if (flags & SECTION_STRINGS)
5740 *f++ = 'S';
5741 if (flags & SECTION_TLS)
5742 *f++ = 'T';
5743 if (HAVE_COMDAT_GROUP && (flags & SECTION_LINKONCE))
5744 *f++ = 'G';
5745 *f = '\0';
5747 fprintf (asm_out_file, "\t.section\t%s,\"%s\"", name, flagchars);
5749 if (!(flags & SECTION_NOTYPE))
5751 const char *type;
5752 const char *format;
5754 if (flags & SECTION_BSS)
5755 type = "nobits";
5756 else
5757 type = "progbits";
5759 format = ",@%s";
5760 #ifdef ASM_COMMENT_START
5761 /* On platforms that use "@" as the assembly comment character,
5762 use "%" instead. */
5763 if (strcmp (ASM_COMMENT_START, "@") == 0)
5764 format = ",%%%s";
5765 #endif
5766 fprintf (asm_out_file, format, type);
5768 if (flags & SECTION_ENTSIZE)
5769 fprintf (asm_out_file, ",%d", flags & SECTION_ENTSIZE);
5770 if (HAVE_COMDAT_GROUP && (flags & SECTION_LINKONCE))
5771 fprintf (asm_out_file, ",%s,comdat",
5772 lang_hooks.decls.comdat_group (decl));
5775 putc ('\n', asm_out_file);
5778 void
5779 default_coff_asm_named_section (const char *name, unsigned int flags,
5780 tree decl ATTRIBUTE_UNUSED)
5782 char flagchars[8], *f = flagchars;
5784 if (flags & SECTION_WRITE)
5785 *f++ = 'w';
5786 if (flags & SECTION_CODE)
5787 *f++ = 'x';
5788 *f = '\0';
5790 fprintf (asm_out_file, "\t.section\t%s,\"%s\"\n", name, flagchars);
5793 void
5794 default_pe_asm_named_section (const char *name, unsigned int flags,
5795 tree decl)
5797 default_coff_asm_named_section (name, flags, decl);
5799 if (flags & SECTION_LINKONCE)
5801 /* Functions may have been compiled at various levels of
5802 optimization so we can't use `same_size' here.
5803 Instead, have the linker pick one. */
5804 fprintf (asm_out_file, "\t.linkonce %s\n",
5805 (flags & SECTION_CODE ? "discard" : "same_size"));
5809 /* The lame default section selector. */
5811 section *
5812 default_select_section (tree decl, int reloc,
5813 unsigned HOST_WIDE_INT align ATTRIBUTE_UNUSED)
5815 if (DECL_P (decl))
5817 if (decl_readonly_section (decl, reloc))
5818 return readonly_data_section;
5820 else if (TREE_CODE (decl) == CONSTRUCTOR)
5822 if (! ((flag_pic && reloc)
5823 || !TREE_READONLY (decl)
5824 || TREE_SIDE_EFFECTS (decl)
5825 || !TREE_CONSTANT (decl)))
5826 return readonly_data_section;
5828 else if (TREE_CODE (decl) == STRING_CST)
5829 return readonly_data_section;
5830 else if (! (flag_pic && reloc))
5831 return readonly_data_section;
5833 return data_section;
5836 enum section_category
5837 categorize_decl_for_section (const_tree decl, int reloc)
5839 enum section_category ret;
5841 if (TREE_CODE (decl) == FUNCTION_DECL)
5842 return SECCAT_TEXT;
5843 else if (TREE_CODE (decl) == STRING_CST)
5845 if (flag_mudflap) /* or !flag_merge_constants */
5846 return SECCAT_RODATA;
5847 else
5848 return SECCAT_RODATA_MERGE_STR;
5850 else if (TREE_CODE (decl) == VAR_DECL)
5852 if (bss_initializer_p (decl))
5853 ret = SECCAT_BSS;
5854 else if (! TREE_READONLY (decl)
5855 || TREE_SIDE_EFFECTS (decl)
5856 || ! TREE_CONSTANT (DECL_INITIAL (decl)))
5858 /* Here the reloc_rw_mask is not testing whether the section should
5859 be read-only or not, but whether the dynamic link will have to
5860 do something. If so, we wish to segregate the data in order to
5861 minimize cache misses inside the dynamic linker. */
5862 if (reloc & targetm.asm_out.reloc_rw_mask ())
5863 ret = reloc == 1 ? SECCAT_DATA_REL_LOCAL : SECCAT_DATA_REL;
5864 else
5865 ret = SECCAT_DATA;
5867 else if (reloc & targetm.asm_out.reloc_rw_mask ())
5868 ret = reloc == 1 ? SECCAT_DATA_REL_RO_LOCAL : SECCAT_DATA_REL_RO;
5869 else if (reloc || flag_merge_constants < 2)
5870 /* C and C++ don't allow different variables to share the same
5871 location. -fmerge-all-constants allows even that (at the
5872 expense of not conforming). */
5873 ret = SECCAT_RODATA;
5874 else if (TREE_CODE (DECL_INITIAL (decl)) == STRING_CST)
5875 ret = SECCAT_RODATA_MERGE_STR_INIT;
5876 else
5877 ret = SECCAT_RODATA_MERGE_CONST;
5879 else if (TREE_CODE (decl) == CONSTRUCTOR)
5881 if ((reloc & targetm.asm_out.reloc_rw_mask ())
5882 || TREE_SIDE_EFFECTS (decl)
5883 || ! TREE_CONSTANT (decl))
5884 ret = SECCAT_DATA;
5885 else
5886 ret = SECCAT_RODATA;
5888 else
5889 ret = SECCAT_RODATA;
5891 /* There are no read-only thread-local sections. */
5892 if (TREE_CODE (decl) == VAR_DECL && DECL_TLS_MODEL (decl))
5894 if (DECL_TLS_MODEL (decl) == TLS_MODEL_EMULATED)
5896 if (DECL_EMUTLS_VAR_P (decl))
5898 if (targetm.emutls.var_section)
5899 ret = SECCAT_EMUTLS_VAR;
5901 else
5903 if (targetm.emutls.tmpl_prefix)
5904 ret = SECCAT_EMUTLS_TMPL;
5907 /* Note that this would be *just* SECCAT_BSS, except that there's
5908 no concept of a read-only thread-local-data section. */
5909 else if (ret == SECCAT_BSS
5910 || (flag_zero_initialized_in_bss
5911 && initializer_zerop (DECL_INITIAL (decl))))
5912 ret = SECCAT_TBSS;
5913 else
5914 ret = SECCAT_TDATA;
5917 /* If the target uses small data sections, select it. */
5918 else if (targetm.in_small_data_p (decl))
5920 if (ret == SECCAT_BSS)
5921 ret = SECCAT_SBSS;
5922 else if (targetm.have_srodata_section && ret == SECCAT_RODATA)
5923 ret = SECCAT_SRODATA;
5924 else
5925 ret = SECCAT_SDATA;
5928 return ret;
5931 bool
5932 decl_readonly_section (const_tree decl, int reloc)
5934 switch (categorize_decl_for_section (decl, reloc))
5936 case SECCAT_RODATA:
5937 case SECCAT_RODATA_MERGE_STR:
5938 case SECCAT_RODATA_MERGE_STR_INIT:
5939 case SECCAT_RODATA_MERGE_CONST:
5940 case SECCAT_SRODATA:
5941 return true;
5942 break;
5943 default:
5944 return false;
5945 break;
5949 /* Select a section based on the above categorization. */
5951 section *
5952 default_elf_select_section (tree decl, int reloc,
5953 unsigned HOST_WIDE_INT align)
5955 const char *sname;
5956 switch (categorize_decl_for_section (decl, reloc))
5958 case SECCAT_TEXT:
5959 /* We're not supposed to be called on FUNCTION_DECLs. */
5960 gcc_unreachable ();
5961 case SECCAT_RODATA:
5962 return readonly_data_section;
5963 case SECCAT_RODATA_MERGE_STR:
5964 return mergeable_string_section (decl, align, 0);
5965 case SECCAT_RODATA_MERGE_STR_INIT:
5966 return mergeable_string_section (DECL_INITIAL (decl), align, 0);
5967 case SECCAT_RODATA_MERGE_CONST:
5968 return mergeable_constant_section (DECL_MODE (decl), align, 0);
5969 case SECCAT_SRODATA:
5970 sname = ".sdata2";
5971 break;
5972 case SECCAT_DATA:
5973 return data_section;
5974 case SECCAT_DATA_REL:
5975 sname = ".data.rel";
5976 break;
5977 case SECCAT_DATA_REL_LOCAL:
5978 sname = ".data.rel.local";
5979 break;
5980 case SECCAT_DATA_REL_RO:
5981 sname = ".data.rel.ro";
5982 break;
5983 case SECCAT_DATA_REL_RO_LOCAL:
5984 sname = ".data.rel.ro.local";
5985 break;
5986 case SECCAT_SDATA:
5987 sname = ".sdata";
5988 break;
5989 case SECCAT_TDATA:
5990 sname = ".tdata";
5991 break;
5992 case SECCAT_BSS:
5993 if (bss_section)
5994 return bss_section;
5995 sname = ".bss";
5996 break;
5997 case SECCAT_SBSS:
5998 sname = ".sbss";
5999 break;
6000 case SECCAT_TBSS:
6001 sname = ".tbss";
6002 break;
6003 case SECCAT_EMUTLS_VAR:
6004 sname = targetm.emutls.var_section;
6005 break;
6006 case SECCAT_EMUTLS_TMPL:
6007 sname = targetm.emutls.tmpl_section;
6008 break;
6009 default:
6010 gcc_unreachable ();
6013 if (!DECL_P (decl))
6014 decl = NULL_TREE;
6015 return get_named_section (decl, sname, reloc);
6018 /* Construct a unique section name based on the decl name and the
6019 categorization performed above. */
6021 void
6022 default_unique_section (tree decl, int reloc)
6024 /* We only need to use .gnu.linkonce if we don't have COMDAT groups. */
6025 bool one_only = DECL_ONE_ONLY (decl) && !HAVE_COMDAT_GROUP;
6026 const char *prefix, *name, *linkonce;
6027 char *string;
6029 switch (categorize_decl_for_section (decl, reloc))
6031 case SECCAT_TEXT:
6032 prefix = one_only ? ".t" : ".text";
6033 break;
6034 case SECCAT_RODATA:
6035 case SECCAT_RODATA_MERGE_STR:
6036 case SECCAT_RODATA_MERGE_STR_INIT:
6037 case SECCAT_RODATA_MERGE_CONST:
6038 prefix = one_only ? ".r" : ".rodata";
6039 break;
6040 case SECCAT_SRODATA:
6041 prefix = one_only ? ".s2" : ".sdata2";
6042 break;
6043 case SECCAT_DATA:
6044 prefix = one_only ? ".d" : ".data";
6045 break;
6046 case SECCAT_DATA_REL:
6047 prefix = one_only ? ".d.rel" : ".data.rel";
6048 break;
6049 case SECCAT_DATA_REL_LOCAL:
6050 prefix = one_only ? ".d.rel.local" : ".data.rel.local";
6051 break;
6052 case SECCAT_DATA_REL_RO:
6053 prefix = one_only ? ".d.rel.ro" : ".data.rel.ro";
6054 break;
6055 case SECCAT_DATA_REL_RO_LOCAL:
6056 prefix = one_only ? ".d.rel.ro.local" : ".data.rel.ro.local";
6057 break;
6058 case SECCAT_SDATA:
6059 prefix = one_only ? ".s" : ".sdata";
6060 break;
6061 case SECCAT_BSS:
6062 prefix = one_only ? ".b" : ".bss";
6063 break;
6064 case SECCAT_SBSS:
6065 prefix = one_only ? ".sb" : ".sbss";
6066 break;
6067 case SECCAT_TDATA:
6068 prefix = one_only ? ".td" : ".tdata";
6069 break;
6070 case SECCAT_TBSS:
6071 prefix = one_only ? ".tb" : ".tbss";
6072 break;
6073 case SECCAT_EMUTLS_VAR:
6074 prefix = targetm.emutls.var_section;
6075 break;
6076 case SECCAT_EMUTLS_TMPL:
6077 prefix = targetm.emutls.tmpl_section;
6078 break;
6079 default:
6080 gcc_unreachable ();
6083 name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
6084 name = targetm.strip_name_encoding (name);
6086 /* If we're using one_only, then there needs to be a .gnu.linkonce
6087 prefix to the section name. */
6088 linkonce = one_only ? ".gnu.linkonce" : "";
6090 string = ACONCAT ((linkonce, prefix, ".", name, NULL));
6092 DECL_SECTION_NAME (decl) = build_string (strlen (string), string);
6095 /* Like compute_reloc_for_constant, except for an RTX. The return value
6096 is a mask for which bit 1 indicates a global relocation, and bit 0
6097 indicates a local relocation. */
6099 static int
6100 compute_reloc_for_rtx_1 (rtx *xp, void *data)
6102 int *preloc = (int *) data;
6103 rtx x = *xp;
6105 switch (GET_CODE (x))
6107 case SYMBOL_REF:
6108 *preloc |= SYMBOL_REF_LOCAL_P (x) ? 1 : 2;
6109 break;
6110 case LABEL_REF:
6111 *preloc |= 1;
6112 break;
6113 default:
6114 break;
6117 return 0;
6120 static int
6121 compute_reloc_for_rtx (rtx x)
6123 int reloc;
6125 switch (GET_CODE (x))
6127 case CONST:
6128 case SYMBOL_REF:
6129 case LABEL_REF:
6130 reloc = 0;
6131 for_each_rtx (&x, compute_reloc_for_rtx_1, &reloc);
6132 return reloc;
6134 default:
6135 return 0;
6139 section *
6140 default_select_rtx_section (enum machine_mode mode ATTRIBUTE_UNUSED,
6141 rtx x,
6142 unsigned HOST_WIDE_INT align ATTRIBUTE_UNUSED)
6144 if (compute_reloc_for_rtx (x) & targetm.asm_out.reloc_rw_mask ())
6145 return data_section;
6146 else
6147 return readonly_data_section;
6150 section *
6151 default_elf_select_rtx_section (enum machine_mode mode, rtx x,
6152 unsigned HOST_WIDE_INT align)
6154 int reloc = compute_reloc_for_rtx (x);
6156 /* ??? Handle small data here somehow. */
6158 if (reloc & targetm.asm_out.reloc_rw_mask ())
6160 if (reloc == 1)
6161 return get_named_section (NULL, ".data.rel.ro.local", 1);
6162 else
6163 return get_named_section (NULL, ".data.rel.ro", 3);
6166 return mergeable_constant_section (mode, align, 0);
6169 /* Set the generally applicable flags on the SYMBOL_REF for EXP. */
6171 void
6172 default_encode_section_info (tree decl, rtx rtl, int first ATTRIBUTE_UNUSED)
6174 rtx symbol;
6175 int flags;
6177 /* Careful not to prod global register variables. */
6178 if (!MEM_P (rtl))
6179 return;
6180 symbol = XEXP (rtl, 0);
6181 if (GET_CODE (symbol) != SYMBOL_REF)
6182 return;
6184 flags = SYMBOL_REF_FLAGS (symbol) & SYMBOL_FLAG_HAS_BLOCK_INFO;
6185 if (TREE_CODE (decl) == FUNCTION_DECL)
6186 flags |= SYMBOL_FLAG_FUNCTION;
6187 if (targetm.binds_local_p (decl))
6188 flags |= SYMBOL_FLAG_LOCAL;
6189 if (targetm.have_tls && TREE_CODE (decl) == VAR_DECL
6190 && DECL_THREAD_LOCAL_P (decl))
6191 flags |= DECL_TLS_MODEL (decl) << SYMBOL_FLAG_TLS_SHIFT;
6192 else if (targetm.in_small_data_p (decl))
6193 flags |= SYMBOL_FLAG_SMALL;
6194 /* ??? Why is DECL_EXTERNAL ever set for non-PUBLIC names? Without
6195 being PUBLIC, the thing *must* be defined in this translation unit.
6196 Prevent this buglet from being propagated into rtl code as well. */
6197 if (DECL_P (decl) && DECL_EXTERNAL (decl) && TREE_PUBLIC (decl))
6198 flags |= SYMBOL_FLAG_EXTERNAL;
6200 SYMBOL_REF_FLAGS (symbol) = flags;
6203 /* By default, we do nothing for encode_section_info, so we need not
6204 do anything but discard the '*' marker. */
6206 const char *
6207 default_strip_name_encoding (const char *str)
6209 return str + (*str == '*');
6212 #ifdef ASM_OUTPUT_DEF
6213 /* The default implementation of TARGET_ASM_OUTPUT_ANCHOR. Define the
6214 anchor relative to ".", the current section position. */
6216 void
6217 default_asm_output_anchor (rtx symbol)
6219 char buffer[100];
6221 sprintf (buffer, "*. + " HOST_WIDE_INT_PRINT_DEC,
6222 SYMBOL_REF_BLOCK_OFFSET (symbol));
6223 ASM_OUTPUT_DEF (asm_out_file, XSTR (symbol, 0), buffer);
6225 #endif
6227 /* The default implementation of TARGET_USE_ANCHORS_FOR_SYMBOL_P. */
6229 bool
6230 default_use_anchors_for_symbol_p (const_rtx symbol)
6232 section *sect;
6233 tree decl;
6235 /* Don't use anchors for mergeable sections. The linker might move
6236 the objects around. */
6237 sect = SYMBOL_REF_BLOCK (symbol)->sect;
6238 if (sect->common.flags & SECTION_MERGE)
6239 return false;
6241 /* Don't use anchors for small data sections. The small data register
6242 acts as an anchor for such sections. */
6243 if (sect->common.flags & SECTION_SMALL)
6244 return false;
6246 decl = SYMBOL_REF_DECL (symbol);
6247 if (decl && DECL_P (decl))
6249 /* Don't use section anchors for decls that might be defined by
6250 other modules. */
6251 if (!targetm.binds_local_p (decl))
6252 return false;
6254 /* Don't use section anchors for decls that will be placed in a
6255 small data section. */
6256 /* ??? Ideally, this check would be redundant with the SECTION_SMALL
6257 one above. The problem is that we only use SECTION_SMALL for
6258 sections that should be marked as small in the section directive. */
6259 if (targetm.in_small_data_p (decl))
6260 return false;
6262 return true;
6265 /* Assume ELF-ish defaults, since that's pretty much the most liberal
6266 wrt cross-module name binding. */
6268 bool
6269 default_binds_local_p (const_tree exp)
6271 return default_binds_local_p_1 (exp, flag_shlib);
6274 bool
6275 default_binds_local_p_1 (const_tree exp, int shlib)
6277 bool local_p;
6279 /* A non-decl is an entry in the constant pool. */
6280 if (!DECL_P (exp))
6281 local_p = true;
6282 /* Weakrefs may not bind locally, even though the weakref itself is
6283 always static and therefore local. */
6284 else if (lookup_attribute ("weakref", DECL_ATTRIBUTES (exp)))
6285 local_p = false;
6286 /* Static variables are always local. */
6287 else if (! TREE_PUBLIC (exp))
6288 local_p = true;
6289 /* A variable is local if the user has said explicitly that it will
6290 be. */
6291 else if (DECL_VISIBILITY_SPECIFIED (exp)
6292 && DECL_VISIBILITY (exp) != VISIBILITY_DEFAULT)
6293 local_p = true;
6294 /* Variables defined outside this object might not be local. */
6295 else if (DECL_EXTERNAL (exp))
6296 local_p = false;
6297 /* If defined in this object and visibility is not default, must be
6298 local. */
6299 else if (DECL_VISIBILITY (exp) != VISIBILITY_DEFAULT)
6300 local_p = true;
6301 /* Default visibility weak data can be overridden by a strong symbol
6302 in another module and so are not local. */
6303 else if (DECL_WEAK (exp))
6304 local_p = false;
6305 /* If PIC, then assume that any global name can be overridden by
6306 symbols resolved from other modules, unless we are compiling with
6307 -fwhole-program, which assumes that names are local. */
6308 else if (shlib)
6309 local_p = flag_whole_program;
6310 /* Uninitialized COMMON variable may be unified with symbols
6311 resolved from other modules. */
6312 else if (DECL_COMMON (exp)
6313 && (DECL_INITIAL (exp) == NULL
6314 || DECL_INITIAL (exp) == error_mark_node))
6315 local_p = false;
6316 /* Otherwise we're left with initialized (or non-common) global data
6317 which is of necessity defined locally. */
6318 else
6319 local_p = true;
6321 return local_p;
6324 /* Determine whether or not a pointer mode is valid. Assume defaults
6325 of ptr_mode or Pmode - can be overridden. */
6326 bool
6327 default_valid_pointer_mode (enum machine_mode mode)
6329 return (mode == ptr_mode || mode == Pmode);
6332 /* Default function to output code that will globalize a label. A
6333 target must define GLOBAL_ASM_OP or provide its own function to
6334 globalize a label. */
6335 #ifdef GLOBAL_ASM_OP
6336 void
6337 default_globalize_label (FILE * stream, const char *name)
6339 fputs (GLOBAL_ASM_OP, stream);
6340 assemble_name (stream, name);
6341 putc ('\n', stream);
6343 #endif /* GLOBAL_ASM_OP */
6345 /* Default function to output code that will globalize a declaration. */
6346 void
6347 default_globalize_decl_name (FILE * stream, tree decl)
6349 const char *name = XSTR (XEXP (DECL_RTL (decl), 0), 0);
6350 targetm.asm_out.globalize_label (stream, name);
6353 /* Default function to output a label for unwind information. The
6354 default is to do nothing. A target that needs nonlocal labels for
6355 unwind information must provide its own function to do this. */
6356 void
6357 default_emit_unwind_label (FILE * stream ATTRIBUTE_UNUSED,
6358 tree decl ATTRIBUTE_UNUSED,
6359 int for_eh ATTRIBUTE_UNUSED,
6360 int empty ATTRIBUTE_UNUSED)
6364 /* Default function to output a label to divide up the exception table.
6365 The default is to do nothing. A target that needs/wants to divide
6366 up the table must provide it's own function to do this. */
6367 void
6368 default_emit_except_table_label (FILE * stream ATTRIBUTE_UNUSED)
6372 /* This is how to output an internal numbered label where PREFIX is
6373 the class of label and LABELNO is the number within the class. */
6375 void
6376 default_internal_label (FILE *stream, const char *prefix,
6377 unsigned long labelno)
6379 char *const buf = (char *) alloca (40 + strlen (prefix));
6380 ASM_GENERATE_INTERNAL_LABEL (buf, prefix, labelno);
6381 ASM_OUTPUT_INTERNAL_LABEL (stream, buf);
6384 /* This is the default behavior at the beginning of a file. It's
6385 controlled by two other target-hook toggles. */
6386 void
6387 default_file_start (void)
6389 if (targetm.file_start_app_off && !flag_verbose_asm)
6390 fputs (ASM_APP_OFF, asm_out_file);
6392 if (targetm.file_start_file_directive)
6393 output_file_directive (asm_out_file, main_input_filename);
6396 /* This is a generic routine suitable for use as TARGET_ASM_FILE_END
6397 which emits a special section directive used to indicate whether or
6398 not this object file needs an executable stack. This is primarily
6399 a GNU extension to ELF but could be used on other targets. */
6401 int trampolines_created;
6403 void
6404 file_end_indicate_exec_stack (void)
6406 unsigned int flags = SECTION_DEBUG;
6407 if (trampolines_created)
6408 flags |= SECTION_CODE;
6410 switch_to_section (get_section (".note.GNU-stack", flags, NULL));
6413 /* Output DIRECTIVE (a C string) followed by a newline. This is used as
6414 a get_unnamed_section callback. */
6416 void
6417 output_section_asm_op (const void *directive)
6419 fprintf (asm_out_file, "%s\n", (const char *) directive);
6422 /* Emit assembly code to switch to section NEW_SECTION. Do nothing if
6423 the current section is NEW_SECTION. */
6425 void
6426 switch_to_section (section *new_section)
6428 if (in_section == new_section)
6429 return;
6431 if (new_section->common.flags & SECTION_FORGET)
6432 in_section = NULL;
6433 else
6434 in_section = new_section;
6436 switch (SECTION_STYLE (new_section))
6438 case SECTION_NAMED:
6439 if (cfun
6440 && !crtl->subsections.unlikely_text_section_name
6441 && strcmp (new_section->named.name,
6442 UNLIKELY_EXECUTED_TEXT_SECTION_NAME) == 0)
6443 crtl->subsections.unlikely_text_section_name = UNLIKELY_EXECUTED_TEXT_SECTION_NAME;
6445 targetm.asm_out.named_section (new_section->named.name,
6446 new_section->named.common.flags,
6447 new_section->named.decl);
6448 break;
6450 case SECTION_UNNAMED:
6451 new_section->unnamed.callback (new_section->unnamed.data);
6452 break;
6454 case SECTION_NOSWITCH:
6455 gcc_unreachable ();
6456 break;
6459 new_section->common.flags |= SECTION_DECLARED;
6462 /* If block symbol SYMBOL has not yet been assigned an offset, place
6463 it at the end of its block. */
6465 void
6466 place_block_symbol (rtx symbol)
6468 unsigned HOST_WIDE_INT size, mask, offset;
6469 struct constant_descriptor_rtx *desc;
6470 unsigned int alignment;
6471 struct object_block *block;
6472 tree decl;
6474 gcc_assert (SYMBOL_REF_BLOCK (symbol));
6475 if (SYMBOL_REF_BLOCK_OFFSET (symbol) >= 0)
6476 return;
6478 /* Work out the symbol's size and alignment. */
6479 if (CONSTANT_POOL_ADDRESS_P (symbol))
6481 desc = SYMBOL_REF_CONSTANT (symbol);
6482 alignment = desc->align;
6483 size = GET_MODE_SIZE (desc->mode);
6485 else if (TREE_CONSTANT_POOL_ADDRESS_P (symbol))
6487 decl = SYMBOL_REF_DECL (symbol);
6488 alignment = get_constant_alignment (decl);
6489 size = get_constant_size (decl);
6491 else
6493 decl = SYMBOL_REF_DECL (symbol);
6494 alignment = DECL_ALIGN (decl);
6495 size = tree_low_cst (DECL_SIZE_UNIT (decl), 1);
6498 /* Calculate the object's offset from the start of the block. */
6499 block = SYMBOL_REF_BLOCK (symbol);
6500 mask = alignment / BITS_PER_UNIT - 1;
6501 offset = (block->size + mask) & ~mask;
6502 SYMBOL_REF_BLOCK_OFFSET (symbol) = offset;
6504 /* Record the block's new alignment and size. */
6505 block->alignment = MAX (block->alignment, alignment);
6506 block->size = offset + size;
6508 VEC_safe_push (rtx, gc, block->objects, symbol);
6511 /* Return the anchor that should be used to address byte offset OFFSET
6512 from the first object in BLOCK. MODEL is the TLS model used
6513 to access it. */
6516 get_section_anchor (struct object_block *block, HOST_WIDE_INT offset,
6517 enum tls_model model)
6519 char label[100];
6520 unsigned int begin, middle, end;
6521 unsigned HOST_WIDE_INT min_offset, max_offset, range, bias, delta;
6522 rtx anchor;
6524 /* Work out the anchor's offset. Use an offset of 0 for the first
6525 anchor so that we don't pessimize the case where we take the address
6526 of a variable at the beginning of the block. This is particularly
6527 useful when a block has only one variable assigned to it.
6529 We try to place anchors RANGE bytes apart, so there can then be
6530 anchors at +/-RANGE, +/-2 * RANGE, and so on, up to the limits of
6531 a ptr_mode offset. With some target settings, the lowest such
6532 anchor might be out of range for the lowest ptr_mode offset;
6533 likewise the highest anchor for the highest offset. Use anchors
6534 at the extreme ends of the ptr_mode range in such cases.
6536 All arithmetic uses unsigned integers in order to avoid
6537 signed overflow. */
6538 max_offset = (unsigned HOST_WIDE_INT) targetm.max_anchor_offset;
6539 min_offset = (unsigned HOST_WIDE_INT) targetm.min_anchor_offset;
6540 range = max_offset - min_offset + 1;
6541 if (range == 0)
6542 offset = 0;
6543 else
6545 bias = 1 << (GET_MODE_BITSIZE (ptr_mode) - 1);
6546 if (offset < 0)
6548 delta = -(unsigned HOST_WIDE_INT) offset + max_offset;
6549 delta -= delta % range;
6550 if (delta > bias)
6551 delta = bias;
6552 offset = (HOST_WIDE_INT) (-delta);
6554 else
6556 delta = (unsigned HOST_WIDE_INT) offset - min_offset;
6557 delta -= delta % range;
6558 if (delta > bias - 1)
6559 delta = bias - 1;
6560 offset = (HOST_WIDE_INT) delta;
6564 /* Do a binary search to see if there's already an anchor we can use.
6565 Set BEGIN to the new anchor's index if not. */
6566 begin = 0;
6567 end = VEC_length (rtx, block->anchors);
6568 while (begin != end)
6570 middle = (end + begin) / 2;
6571 anchor = VEC_index (rtx, block->anchors, middle);
6572 if (SYMBOL_REF_BLOCK_OFFSET (anchor) > offset)
6573 end = middle;
6574 else if (SYMBOL_REF_BLOCK_OFFSET (anchor) < offset)
6575 begin = middle + 1;
6576 else if (SYMBOL_REF_TLS_MODEL (anchor) > model)
6577 end = middle;
6578 else if (SYMBOL_REF_TLS_MODEL (anchor) < model)
6579 begin = middle + 1;
6580 else
6581 return anchor;
6584 /* Create a new anchor with a unique label. */
6585 ASM_GENERATE_INTERNAL_LABEL (label, "LANCHOR", anchor_labelno++);
6586 anchor = create_block_symbol (ggc_strdup (label), block, offset);
6587 SYMBOL_REF_FLAGS (anchor) |= SYMBOL_FLAG_LOCAL | SYMBOL_FLAG_ANCHOR;
6588 SYMBOL_REF_FLAGS (anchor) |= model << SYMBOL_FLAG_TLS_SHIFT;
6590 /* Insert it at index BEGIN. */
6591 VEC_safe_insert (rtx, gc, block->anchors, begin, anchor);
6592 return anchor;
6595 /* Output the objects in BLOCK. */
6597 static void
6598 output_object_block (struct object_block *block)
6600 struct constant_descriptor_rtx *desc;
6601 unsigned int i;
6602 HOST_WIDE_INT offset;
6603 tree decl;
6604 rtx symbol;
6606 if (block->objects == NULL)
6607 return;
6609 /* Switch to the section and make sure that the first byte is
6610 suitably aligned. */
6611 switch_to_section (block->sect);
6612 assemble_align (block->alignment);
6614 /* Define the values of all anchors relative to the current section
6615 position. */
6616 for (i = 0; VEC_iterate (rtx, block->anchors, i, symbol); i++)
6617 targetm.asm_out.output_anchor (symbol);
6619 /* Output the objects themselves. */
6620 offset = 0;
6621 for (i = 0; VEC_iterate (rtx, block->objects, i, symbol); i++)
6623 /* Move to the object's offset, padding with zeros if necessary. */
6624 assemble_zeros (SYMBOL_REF_BLOCK_OFFSET (symbol) - offset);
6625 offset = SYMBOL_REF_BLOCK_OFFSET (symbol);
6626 if (CONSTANT_POOL_ADDRESS_P (symbol))
6628 desc = SYMBOL_REF_CONSTANT (symbol);
6629 output_constant_pool_1 (desc, 1);
6630 offset += GET_MODE_SIZE (desc->mode);
6632 else if (TREE_CONSTANT_POOL_ADDRESS_P (symbol))
6634 decl = SYMBOL_REF_DECL (symbol);
6635 assemble_constant_contents (decl, XSTR (symbol, 0),
6636 get_constant_alignment (decl));
6637 offset += get_constant_size (decl);
6639 else
6641 decl = SYMBOL_REF_DECL (symbol);
6642 assemble_variable_contents (decl, XSTR (symbol, 0), false);
6643 offset += tree_low_cst (DECL_SIZE_UNIT (decl), 1);
6648 /* A htab_traverse callback used to call output_object_block for
6649 each member of object_block_htab. */
6651 static int
6652 output_object_block_htab (void **slot, void *data ATTRIBUTE_UNUSED)
6654 output_object_block ((struct object_block *) (*slot));
6655 return 1;
6658 /* Output the definitions of all object_blocks. */
6660 void
6661 output_object_blocks (void)
6663 htab_traverse (object_block_htab, output_object_block_htab, NULL);
6666 /* This function provides a possible implementation of the
6667 TARGET_ASM_RECORD_GCC_SWITCHES target hook for ELF targets. When triggered
6668 by -frecord-gcc-switches it creates a new mergeable, string section in the
6669 assembler output file called TARGET_ASM_RECORD_GCC_SWITCHES_SECTION which
6670 contains the switches in ASCII format.
6672 FIXME: This code does not correctly handle double quote characters
6673 that appear inside strings, (it strips them rather than preserving them).
6674 FIXME: ASM_OUTPUT_ASCII, as defined in config/elfos.h will not emit NUL
6675 characters - instead it treats them as sub-string separators. Since
6676 we want to emit NUL strings terminators into the object file we have to use
6677 ASM_OUTPUT_SKIP. */
6680 elf_record_gcc_switches (print_switch_type type, const char * name)
6682 static char buffer[1024];
6684 /* This variable is used as part of a simplistic heuristic to detect
6685 command line switches which take an argument:
6687 "If a command line option does not start with a dash then
6688 it is an argument for the previous command line option."
6690 This fails in the case of the command line option which is the name
6691 of the file to compile, but otherwise it is pretty reasonable. */
6692 static bool previous_name_held_back = FALSE;
6694 switch (type)
6696 case SWITCH_TYPE_PASSED:
6697 if (* name != '-')
6699 if (previous_name_held_back)
6701 unsigned int len = strlen (buffer);
6703 snprintf (buffer + len, sizeof buffer - len, " %s", name);
6704 ASM_OUTPUT_ASCII (asm_out_file, buffer, strlen (buffer));
6705 ASM_OUTPUT_SKIP (asm_out_file, (unsigned HOST_WIDE_INT) 1);
6706 previous_name_held_back = FALSE;
6708 else
6710 strncpy (buffer, name, sizeof buffer);
6711 ASM_OUTPUT_ASCII (asm_out_file, buffer, strlen (buffer));
6712 ASM_OUTPUT_SKIP (asm_out_file, (unsigned HOST_WIDE_INT) 1);
6715 else
6717 if (previous_name_held_back)
6719 ASM_OUTPUT_ASCII (asm_out_file, buffer, strlen (buffer));
6720 ASM_OUTPUT_SKIP (asm_out_file, (unsigned HOST_WIDE_INT) 1);
6723 strncpy (buffer, name, sizeof buffer);
6724 previous_name_held_back = TRUE;
6726 break;
6728 case SWITCH_TYPE_DESCRIPTIVE:
6729 if (name == NULL)
6731 /* Distinguish between invocations where name is NULL. */
6732 static bool started = false;
6734 if (started)
6736 if (previous_name_held_back)
6738 ASM_OUTPUT_ASCII (asm_out_file, buffer, strlen (buffer));
6739 ASM_OUTPUT_SKIP (asm_out_file, (unsigned HOST_WIDE_INT) 1);
6742 else
6744 section * sec;
6746 sec = get_section (targetm.asm_out.record_gcc_switches_section,
6747 SECTION_DEBUG
6748 | SECTION_MERGE
6749 | SECTION_STRINGS
6750 | (SECTION_ENTSIZE & 1),
6751 NULL);
6752 switch_to_section (sec);
6753 started = true;
6757 default:
6758 break;
6761 /* The return value is currently ignored by the caller, but must be 0.
6762 For -fverbose-asm the return value would be the number of characters
6763 emitted into the assembler file. */
6764 return 0;
6767 /* Emit text to declare externally defined symbols. It is needed to
6768 properly support non-default visibility. */
6769 void
6770 default_elf_asm_output_external (FILE *file ATTRIBUTE_UNUSED,
6771 tree decl,
6772 const char *name ATTRIBUTE_UNUSED)
6774 /* We output the name if and only if TREE_SYMBOL_REFERENCED is
6775 set in order to avoid putting out names that are never really
6776 used. */
6777 if (TREE_SYMBOL_REFERENCED (DECL_ASSEMBLER_NAME (decl))
6778 && targetm.binds_local_p (decl))
6779 maybe_assemble_visibility (decl);
6782 #include "gt-varasm.h"