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[official-gcc.git] / gomp-20050608-branch / gcc / varasm.c
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1 /* Output variables, constants and external declarations, for GNU compiler.
2 Copyright (C) 1987, 1988, 1989, 1992, 1993, 1994, 1995, 1996, 1997,
3 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006
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 2, 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 COPYING. If not, write to the Free
20 Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA
21 02110-1301, USA. */
24 /* This file handles generation of all the assembler code
25 *except* the instructions of a function.
26 This includes declarations of variables and their initial values.
28 We also output the assembler code for constants stored in memory
29 and are responsible for combining constants with the same value. */
31 #include "config.h"
32 #include "system.h"
33 #include "coretypes.h"
34 #include "tm.h"
35 #include "rtl.h"
36 #include "tree.h"
37 #include "flags.h"
38 #include "function.h"
39 #include "expr.h"
40 #include "hard-reg-set.h"
41 #include "regs.h"
42 #include "real.h"
43 #include "output.h"
44 #include "toplev.h"
45 #include "hashtab.h"
46 #include "c-pragma.h"
47 #include "ggc.h"
48 #include "langhooks.h"
49 #include "tm_p.h"
50 #include "debug.h"
51 #include "target.h"
52 #include "tree-mudflap.h"
53 #include "cgraph.h"
54 #include "cfglayout.h"
55 #include "basic-block.h"
57 #ifdef XCOFF_DEBUGGING_INFO
58 #include "xcoffout.h" /* Needed for external data
59 declarations for e.g. AIX 4.x. */
60 #endif
62 /* The (assembler) name of the first globally-visible object output. */
63 extern GTY(()) const char *first_global_object_name;
64 extern GTY(()) const char *weak_global_object_name;
66 const char *first_global_object_name;
67 const char *weak_global_object_name;
69 struct addr_const;
70 struct constant_descriptor_rtx;
71 struct rtx_constant_pool;
73 struct varasm_status GTY(())
75 /* If we're using a per-function constant pool, this is it. */
76 struct rtx_constant_pool *pool;
78 /* Number of tree-constants deferred during the expansion of this
79 function. */
80 unsigned int deferred_constants;
83 #define n_deferred_constants (cfun->varasm->deferred_constants)
85 /* Number for making the label on the next
86 constant that is stored in memory. */
88 static GTY(()) int const_labelno;
90 /* Carry information from ASM_DECLARE_OBJECT_NAME
91 to ASM_FINISH_DECLARE_OBJECT. */
93 int size_directive_output;
95 /* The last decl for which assemble_variable was called,
96 if it did ASM_DECLARE_OBJECT_NAME.
97 If the last call to assemble_variable didn't do that,
98 this holds 0. */
100 tree last_assemble_variable_decl;
102 /* The following global variable indicates if the first basic block
103 in a function belongs to the cold partition or not. */
105 bool first_function_block_is_cold;
107 /* We give all constants their own alias set. Perhaps redundant with
108 MEM_READONLY_P, but pre-dates it. */
110 static HOST_WIDE_INT const_alias_set;
112 static const char *strip_reg_name (const char *);
113 static int contains_pointers_p (tree);
114 #ifdef ASM_OUTPUT_EXTERNAL
115 static bool incorporeal_function_p (tree);
116 #endif
117 static void decode_addr_const (tree, struct addr_const *);
118 static hashval_t const_desc_hash (const void *);
119 static int const_desc_eq (const void *, const void *);
120 static hashval_t const_hash_1 (const tree);
121 static int compare_constant (const tree, const tree);
122 static tree copy_constant (tree);
123 static void output_constant_def_contents (rtx);
124 static void output_addressed_constants (tree);
125 static unsigned HOST_WIDE_INT array_size_for_constructor (tree);
126 static unsigned min_align (unsigned, unsigned);
127 static void output_constructor (tree, unsigned HOST_WIDE_INT, unsigned int);
128 static void globalize_decl (tree);
129 static void maybe_assemble_visibility (tree);
130 #ifdef BSS_SECTION_ASM_OP
131 #ifdef ASM_OUTPUT_BSS
132 static void asm_output_bss (FILE *, tree, const char *,
133 unsigned HOST_WIDE_INT, unsigned HOST_WIDE_INT);
134 #endif
135 #ifdef ASM_OUTPUT_ALIGNED_BSS
136 static void asm_output_aligned_bss (FILE *, tree, const char *,
137 unsigned HOST_WIDE_INT, int)
138 ATTRIBUTE_UNUSED;
139 #endif
140 #endif /* BSS_SECTION_ASM_OP */
141 static bool asm_emit_uninitialised (tree, const char*,
142 unsigned HOST_WIDE_INT,
143 unsigned HOST_WIDE_INT);
144 static void mark_weak (tree);
146 /* Well-known sections, each one associated with some sort of *_ASM_OP. */
147 section *text_section;
148 section *data_section;
149 section *readonly_data_section;
150 section *sdata_section;
151 section *ctors_section;
152 section *dtors_section;
153 section *bss_section;
154 section *sbss_section;
156 /* The section that holds the main exception table, when known. The section
157 is set either by the target's init_sections hook or by the first call to
158 switch_to_exception_section. */
159 section *exception_section;
161 /* The section that holds the DWARF2 frame unwind information, when known.
162 The section is set either by the target's init_sections hook or by the
163 first call to switch_to_eh_frame_section. */
164 section *eh_frame_section;
166 /* asm_out_file's current section. This is NULL if no section has yet
167 been selected or if we lose track of what the current section is. */
168 section *in_section;
170 /* True if code for the current function is currently being directed
171 at the cold section. */
172 bool in_cold_section_p;
174 /* A linked list of all the unnamed sections. */
175 static GTY(()) section *unnamed_sections;
177 /* Return a nonzero value if DECL has a section attribute. */
178 #ifndef IN_NAMED_SECTION
179 #define IN_NAMED_SECTION(DECL) \
180 ((TREE_CODE (DECL) == FUNCTION_DECL || TREE_CODE (DECL) == VAR_DECL) \
181 && DECL_SECTION_NAME (DECL) != NULL_TREE)
182 #endif
184 /* Hash table of named sections. */
185 static GTY((param_is (section))) htab_t section_htab;
187 /* Helper routines for maintaining section_htab. */
189 static int
190 section_entry_eq (const void *p1, const void *p2)
192 const section *old = p1;
193 const char *new = p2;
195 return strcmp (old->named.name, new) == 0;
198 static hashval_t
199 section_entry_hash (const void *p)
201 const section *old = p;
202 return htab_hash_string (old->named.name);
205 /* Return a new unnamed section with the given fields. */
207 section *
208 get_unnamed_section (unsigned int flags, void (*callback) (const void *),
209 const void *data)
211 section *sect;
213 sect = ggc_alloc (sizeof (struct unnamed_section));
214 sect->unnamed.common.flags = flags;
215 sect->unnamed.callback = callback;
216 sect->unnamed.data = data;
217 sect->unnamed.next = unnamed_sections;
219 unnamed_sections = sect;
220 return sect;
223 /* Return the named section structure associated with NAME. Create
224 a new section with the given fields if no such structure exists. */
226 section *
227 get_section (const char *name, unsigned int flags, tree decl)
229 section *sect, **slot;
231 slot = (section **)
232 htab_find_slot_with_hash (section_htab, name,
233 htab_hash_string (name), INSERT);
234 flags |= SECTION_NAMED;
235 if (*slot == NULL)
237 sect = ggc_alloc (sizeof (struct named_section));
238 sect->named.common.flags = flags;
239 sect->named.name = ggc_strdup (name);
240 sect->named.decl = decl;
241 *slot = sect;
243 else
245 sect = *slot;
246 if ((sect->common.flags & ~SECTION_DECLARED) != flags
247 && ((sect->common.flags | flags) & SECTION_OVERRIDE) == 0)
249 /* Sanity check user variables for flag changes. */
250 if (decl == 0)
251 decl = sect->named.decl;
252 gcc_assert (decl);
253 error ("%+D causes a section type conflict", decl);
256 return sect;
259 static void
260 initialize_cold_section_name (void)
262 const char *stripped_name;
263 char *name, *buffer;
264 tree dsn;
266 gcc_assert (cfun && current_function_decl);
267 if (cfun->unlikely_text_section_name)
268 return;
270 dsn = DECL_SECTION_NAME (current_function_decl);
271 if (flag_function_sections && dsn)
273 name = alloca (TREE_STRING_LENGTH (dsn) + 1);
274 memcpy (name, TREE_STRING_POINTER (dsn), TREE_STRING_LENGTH (dsn) + 1);
276 stripped_name = targetm.strip_name_encoding (name);
278 buffer = ACONCAT ((stripped_name, "_unlikely", NULL));
279 cfun->unlikely_text_section_name = ggc_strdup (buffer);
281 else
282 cfun->unlikely_text_section_name = UNLIKELY_EXECUTED_TEXT_SECTION_NAME;
285 /* Tell assembler to switch to unlikely-to-be-executed text section. */
287 section *
288 unlikely_text_section (void)
290 if (cfun)
292 if (!cfun->unlikely_text_section_name)
293 initialize_cold_section_name ();
295 return get_named_section (NULL, cfun->unlikely_text_section_name, 0);
297 else
298 return get_named_section (NULL, UNLIKELY_EXECUTED_TEXT_SECTION_NAME, 0);
301 /* When called within a function context, return true if the function
302 has been assigned a cold text section and if SECT is that section.
303 When called outside a function context, return true if SECT is the
304 default cold section. */
306 bool
307 unlikely_text_section_p (section *sect)
309 const char *name;
311 if (cfun)
312 name = cfun->unlikely_text_section_name;
313 else
314 name = UNLIKELY_EXECUTED_TEXT_SECTION_NAME;
316 return (name
317 && sect
318 && (sect->common.flags & SECTION_NAMED) != 0
319 && strcmp (name, sect->named.name) == 0);
322 /* Return a section with a particular name and with whatever SECTION_*
323 flags section_type_flags deems appropriate. The name of the section
324 is taken from NAME if nonnull, otherwise it is taken from DECL's
325 DECL_SECTION_NAME. DECL is the decl associated with the section
326 (see the section comment for details) and RELOC is as for
327 section_type_flags. */
329 section *
330 get_named_section (tree decl, const char *name, int reloc)
332 unsigned int flags;
334 gcc_assert (!decl || DECL_P (decl));
335 if (name == NULL)
336 name = TREE_STRING_POINTER (DECL_SECTION_NAME (decl));
338 flags = targetm.section_type_flags (decl, name, reloc);
340 return get_section (name, flags, decl);
343 /* If required, set DECL_SECTION_NAME to a unique name. */
345 void
346 resolve_unique_section (tree decl, int reloc ATTRIBUTE_UNUSED,
347 int flag_function_or_data_sections)
349 if (DECL_SECTION_NAME (decl) == NULL_TREE
350 && targetm.have_named_sections
351 && (flag_function_or_data_sections
352 || DECL_ONE_ONLY (decl)))
353 targetm.asm_out.unique_section (decl, reloc);
356 #ifdef BSS_SECTION_ASM_OP
358 #ifdef ASM_OUTPUT_BSS
360 /* Utility function for ASM_OUTPUT_BSS for targets to use if
361 they don't support alignments in .bss.
362 ??? It is believed that this function will work in most cases so such
363 support is localized here. */
365 static void
366 asm_output_bss (FILE *file, tree decl ATTRIBUTE_UNUSED,
367 const char *name,
368 unsigned HOST_WIDE_INT size ATTRIBUTE_UNUSED,
369 unsigned HOST_WIDE_INT rounded)
371 targetm.asm_out.globalize_label (file, name);
372 switch_to_section (bss_section);
373 #ifdef ASM_DECLARE_OBJECT_NAME
374 last_assemble_variable_decl = decl;
375 ASM_DECLARE_OBJECT_NAME (file, name, decl);
376 #else
377 /* Standard thing is just output label for the object. */
378 ASM_OUTPUT_LABEL (file, name);
379 #endif /* ASM_DECLARE_OBJECT_NAME */
380 ASM_OUTPUT_SKIP (file, rounded ? rounded : 1);
383 #endif
385 #ifdef ASM_OUTPUT_ALIGNED_BSS
387 /* Utility function for targets to use in implementing
388 ASM_OUTPUT_ALIGNED_BSS.
389 ??? It is believed that this function will work in most cases so such
390 support is localized here. */
392 static void
393 asm_output_aligned_bss (FILE *file, tree decl ATTRIBUTE_UNUSED,
394 const char *name, unsigned HOST_WIDE_INT size,
395 int align)
397 switch_to_section (bss_section);
398 ASM_OUTPUT_ALIGN (file, floor_log2 (align / BITS_PER_UNIT));
399 #ifdef ASM_DECLARE_OBJECT_NAME
400 last_assemble_variable_decl = decl;
401 ASM_DECLARE_OBJECT_NAME (file, name, decl);
402 #else
403 /* Standard thing is just output label for the object. */
404 ASM_OUTPUT_LABEL (file, name);
405 #endif /* ASM_DECLARE_OBJECT_NAME */
406 ASM_OUTPUT_SKIP (file, size ? size : 1);
409 #endif
411 #endif /* BSS_SECTION_ASM_OP */
413 #ifndef USE_SELECT_SECTION_FOR_FUNCTIONS
414 /* Return the hot section for function DECL. Return text_section for
415 null DECLs. */
417 static section *
418 hot_function_section (tree decl)
420 if (decl != NULL_TREE
421 && DECL_SECTION_NAME (decl) != NULL_TREE
422 && targetm.have_named_sections)
423 return get_named_section (decl, NULL, 0);
424 else
425 return text_section;
427 #endif
429 /* Return the section for function DECL.
431 If DECL is NULL_TREE, return the text section. We can be passed
432 NULL_TREE under some circumstances by dbxout.c at least. */
434 section *
435 function_section (tree decl)
437 int reloc = 0;
439 if (first_function_block_is_cold)
440 reloc = 1;
442 #ifdef USE_SELECT_SECTION_FOR_FUNCTIONS
443 if (decl != NULL_TREE
444 && DECL_SECTION_NAME (decl) != NULL_TREE)
445 return reloc ? unlikely_text_section ()
446 : get_named_section (decl, NULL, 0);
447 else
448 return targetm.asm_out.select_section (decl, reloc, DECL_ALIGN (decl));
449 #else
450 return reloc ? unlikely_text_section () : hot_function_section (decl);
451 #endif
454 section *
455 current_function_section (void)
457 #ifdef USE_SELECT_SECTION_FOR_FUNCTIONS
458 if (current_function_decl != NULL_TREE
459 && DECL_SECTION_NAME (current_function_decl) != NULL_TREE)
460 return in_cold_section_p ? unlikely_text_section ()
461 : get_named_section (current_function_decl,
462 NULL, 0);
463 else
464 return targetm.asm_out.select_section (current_function_decl,
465 in_cold_section_p,
466 DECL_ALIGN (current_function_decl));
467 #else
468 return (in_cold_section_p
469 ? unlikely_text_section ()
470 : hot_function_section (current_function_decl));
471 #endif
474 /* Return the read-only data section associated with function DECL. */
476 section *
477 default_function_rodata_section (tree decl)
479 if (decl != NULL_TREE && DECL_SECTION_NAME (decl))
481 const char *name = TREE_STRING_POINTER (DECL_SECTION_NAME (decl));
483 if (DECL_ONE_ONLY (decl) && HAVE_COMDAT_GROUP)
485 size_t len = strlen (name) + 3;
486 char* rname = alloca (len);
488 strcpy (rname, ".rodata");
489 strcat (rname, name + 5);
490 return get_section (rname, SECTION_LINKONCE, decl);
492 /* For .gnu.linkonce.t.foo we want to use .gnu.linkonce.r.foo. */
493 else if (DECL_ONE_ONLY (decl)
494 && strncmp (name, ".gnu.linkonce.t.", 16) == 0)
496 size_t len = strlen (name) + 1;
497 char *rname = alloca (len);
499 memcpy (rname, name, len);
500 rname[14] = 'r';
501 return get_section (rname, SECTION_LINKONCE, decl);
503 /* For .text.foo we want to use .rodata.foo. */
504 else if (flag_function_sections && flag_data_sections
505 && strncmp (name, ".text.", 6) == 0)
507 size_t len = strlen (name) + 1;
508 char *rname = alloca (len + 2);
510 memcpy (rname, ".rodata", 7);
511 memcpy (rname + 7, name + 5, len - 5);
512 return get_section (rname, 0, decl);
516 return readonly_data_section;
519 /* Return the read-only data section associated with function DECL
520 for targets where that section should be always the single
521 readonly data section. */
523 section *
524 default_no_function_rodata_section (tree decl ATTRIBUTE_UNUSED)
526 return readonly_data_section;
529 /* Switch to section for variable DECL. RELOC is the same as the
530 argument to SELECT_SECTION. */
532 void
533 variable_section (tree decl, int reloc)
535 if (IN_NAMED_SECTION (decl))
536 switch_to_section (get_named_section (decl, NULL, reloc));
537 else
538 switch_to_section (targetm.asm_out.select_section (decl, reloc,
539 DECL_ALIGN (decl)));
542 /* Return the section to use for string merging. */
544 static section *
545 mergeable_string_section (tree decl ATTRIBUTE_UNUSED,
546 unsigned HOST_WIDE_INT align ATTRIBUTE_UNUSED,
547 unsigned int flags ATTRIBUTE_UNUSED)
549 if (HAVE_GAS_SHF_MERGE && flag_merge_constants
550 && TREE_CODE (decl) == STRING_CST
551 && TREE_CODE (TREE_TYPE (decl)) == ARRAY_TYPE
552 && align <= 256
553 && TREE_STRING_LENGTH (decl) >= int_size_in_bytes (TREE_TYPE (decl)))
555 enum machine_mode mode;
556 unsigned int modesize;
557 const char *str;
558 int i, j, len, unit;
559 char name[30];
561 mode = TYPE_MODE (TREE_TYPE (TREE_TYPE (decl)));
562 modesize = GET_MODE_BITSIZE (mode);
563 if (modesize >= 8 && modesize <= 256
564 && (modesize & (modesize - 1)) == 0)
566 if (align < modesize)
567 align = modesize;
569 str = TREE_STRING_POINTER (decl);
570 len = TREE_STRING_LENGTH (decl);
571 unit = GET_MODE_SIZE (mode);
573 /* Check for embedded NUL characters. */
574 for (i = 0; i < len; i += unit)
576 for (j = 0; j < unit; j++)
577 if (str[i + j] != '\0')
578 break;
579 if (j == unit)
580 break;
582 if (i == len - unit)
584 sprintf (name, ".rodata.str%d.%d", modesize / 8,
585 (int) (align / 8));
586 flags |= (modesize / 8) | SECTION_MERGE | SECTION_STRINGS;
587 return get_section (name, flags, NULL);
592 return readonly_data_section;
595 /* Return the section to use for constant merging. */
597 section *
598 mergeable_constant_section (enum machine_mode mode ATTRIBUTE_UNUSED,
599 unsigned HOST_WIDE_INT align ATTRIBUTE_UNUSED,
600 unsigned int flags ATTRIBUTE_UNUSED)
602 unsigned int modesize = GET_MODE_BITSIZE (mode);
604 if (HAVE_GAS_SHF_MERGE && flag_merge_constants
605 && mode != VOIDmode
606 && mode != BLKmode
607 && modesize <= align
608 && align >= 8
609 && align <= 256
610 && (align & (align - 1)) == 0)
612 char name[24];
614 sprintf (name, ".rodata.cst%d", (int) (align / 8));
615 flags |= (align / 8) | SECTION_MERGE;
616 return get_section (name, flags, NULL);
618 return readonly_data_section;
621 /* Given NAME, a putative register name, discard any customary prefixes. */
623 static const char *
624 strip_reg_name (const char *name)
626 #ifdef REGISTER_PREFIX
627 if (!strncmp (name, REGISTER_PREFIX, strlen (REGISTER_PREFIX)))
628 name += strlen (REGISTER_PREFIX);
629 #endif
630 if (name[0] == '%' || name[0] == '#')
631 name++;
632 return name;
635 /* The user has asked for a DECL to have a particular name. Set (or
636 change) it in such a way that we don't prefix an underscore to
637 it. */
638 void
639 set_user_assembler_name (tree decl, const char *name)
641 char *starred = alloca (strlen (name) + 2);
642 starred[0] = '*';
643 strcpy (starred + 1, name);
644 change_decl_assembler_name (decl, get_identifier (starred));
645 SET_DECL_RTL (decl, NULL_RTX);
648 /* Decode an `asm' spec for a declaration as a register name.
649 Return the register number, or -1 if nothing specified,
650 or -2 if the ASMSPEC is not `cc' or `memory' and is not recognized,
651 or -3 if ASMSPEC is `cc' and is not recognized,
652 or -4 if ASMSPEC is `memory' and is not recognized.
653 Accept an exact spelling or a decimal number.
654 Prefixes such as % are optional. */
657 decode_reg_name (const char *asmspec)
659 if (asmspec != 0)
661 int i;
663 /* Get rid of confusing prefixes. */
664 asmspec = strip_reg_name (asmspec);
666 /* Allow a decimal number as a "register name". */
667 for (i = strlen (asmspec) - 1; i >= 0; i--)
668 if (! ISDIGIT (asmspec[i]))
669 break;
670 if (asmspec[0] != 0 && i < 0)
672 i = atoi (asmspec);
673 if (i < FIRST_PSEUDO_REGISTER && i >= 0)
674 return i;
675 else
676 return -2;
679 for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
680 if (reg_names[i][0]
681 && ! strcmp (asmspec, strip_reg_name (reg_names[i])))
682 return i;
684 #ifdef ADDITIONAL_REGISTER_NAMES
686 static const struct { const char *const name; const int number; } table[]
687 = ADDITIONAL_REGISTER_NAMES;
689 for (i = 0; i < (int) ARRAY_SIZE (table); i++)
690 if (table[i].name[0]
691 && ! strcmp (asmspec, table[i].name))
692 return table[i].number;
694 #endif /* ADDITIONAL_REGISTER_NAMES */
696 if (!strcmp (asmspec, "memory"))
697 return -4;
699 if (!strcmp (asmspec, "cc"))
700 return -3;
702 return -2;
705 return -1;
708 /* Create the DECL_RTL for a VAR_DECL or FUNCTION_DECL. DECL should
709 have static storage duration. In other words, it should not be an
710 automatic variable, including PARM_DECLs.
712 There is, however, one exception: this function handles variables
713 explicitly placed in a particular register by the user.
715 This is never called for PARM_DECL nodes. */
717 void
718 make_decl_rtl (tree decl)
720 const char *name = 0;
721 int reg_number;
722 rtx x;
724 /* Check that we are not being given an automatic variable. */
725 gcc_assert (TREE_CODE (decl) != PARM_DECL
726 && TREE_CODE (decl) != RESULT_DECL);
728 /* A weak alias has TREE_PUBLIC set but not the other bits. */
729 gcc_assert (TREE_CODE (decl) != VAR_DECL
730 || TREE_STATIC (decl)
731 || TREE_PUBLIC (decl)
732 || DECL_EXTERNAL (decl)
733 || DECL_REGISTER (decl));
735 /* And that we were not given a type or a label. */
736 gcc_assert (TREE_CODE (decl) != TYPE_DECL
737 && TREE_CODE (decl) != LABEL_DECL);
739 /* For a duplicate declaration, we can be called twice on the
740 same DECL node. Don't discard the RTL already made. */
741 if (DECL_RTL_SET_P (decl))
743 /* If the old RTL had the wrong mode, fix the mode. */
744 if (GET_MODE (DECL_RTL (decl)) != DECL_MODE (decl))
745 SET_DECL_RTL (decl, adjust_address_nv (DECL_RTL (decl),
746 DECL_MODE (decl), 0));
748 if (TREE_CODE (decl) != FUNCTION_DECL && DECL_REGISTER (decl))
749 return;
751 /* ??? Another way to do this would be to maintain a hashed
752 table of such critters. Instead of adding stuff to a DECL
753 to give certain attributes to it, we could use an external
754 hash map from DECL to set of attributes. */
756 /* Let the target reassign the RTL if it wants.
757 This is necessary, for example, when one machine specific
758 decl attribute overrides another. */
759 targetm.encode_section_info (decl, DECL_RTL (decl), false);
761 /* Make this function static known to the mudflap runtime. */
762 if (flag_mudflap && TREE_CODE (decl) == VAR_DECL)
763 mudflap_enqueue_decl (decl);
765 return;
768 name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
770 if (name[0] != '*' && TREE_CODE (decl) != FUNCTION_DECL
771 && DECL_REGISTER (decl))
773 error ("register name not specified for %q+D", decl);
775 else if (TREE_CODE (decl) != FUNCTION_DECL && DECL_REGISTER (decl))
777 const char *asmspec = name+1;
778 reg_number = decode_reg_name (asmspec);
779 /* First detect errors in declaring global registers. */
780 if (reg_number == -1)
781 error ("register name not specified for %q+D", decl);
782 else if (reg_number < 0)
783 error ("invalid register name for %q+D", decl);
784 else if (TYPE_MODE (TREE_TYPE (decl)) == BLKmode)
785 error ("data type of %q+D isn%'t suitable for a register",
786 decl);
787 else if (! HARD_REGNO_MODE_OK (reg_number, TYPE_MODE (TREE_TYPE (decl))))
788 error ("register specified for %q+D isn%'t suitable for data type",
789 decl);
790 /* Now handle properly declared static register variables. */
791 else
793 int nregs;
795 if (DECL_INITIAL (decl) != 0 && TREE_STATIC (decl))
797 DECL_INITIAL (decl) = 0;
798 error ("global register variable has initial value");
800 if (TREE_THIS_VOLATILE (decl))
801 warning (OPT_Wvolatile_register_var,
802 "optimization may eliminate reads and/or "
803 "writes to register variables");
805 /* If the user specified one of the eliminables registers here,
806 e.g., FRAME_POINTER_REGNUM, we don't want to get this variable
807 confused with that register and be eliminated. This usage is
808 somewhat suspect... */
810 SET_DECL_RTL (decl, gen_rtx_raw_REG (DECL_MODE (decl), reg_number));
811 ORIGINAL_REGNO (DECL_RTL (decl)) = reg_number;
812 REG_USERVAR_P (DECL_RTL (decl)) = 1;
814 if (TREE_STATIC (decl))
816 /* Make this register global, so not usable for anything
817 else. */
818 #ifdef ASM_DECLARE_REGISTER_GLOBAL
819 name = IDENTIFIER_POINTER (DECL_NAME (decl));
820 ASM_DECLARE_REGISTER_GLOBAL (asm_out_file, decl, reg_number, name);
821 #endif
822 nregs = hard_regno_nregs[reg_number][DECL_MODE (decl)];
823 while (nregs > 0)
824 globalize_reg (reg_number + --nregs);
827 /* As a register variable, it has no section. */
828 return;
831 /* Now handle ordinary static variables and functions (in memory).
832 Also handle vars declared register invalidly. */
833 else if (name[0] == '*')
835 #ifdef REGISTER_PREFIX
836 if (strlen (REGISTER_PREFIX) != 0)
838 reg_number = decode_reg_name (name);
839 if (reg_number >= 0 || reg_number == -3)
840 error ("register name given for non-register variable %q+D", decl);
842 #endif
845 /* Specifying a section attribute on a variable forces it into a
846 non-.bss section, and thus it cannot be common. */
847 if (TREE_CODE (decl) == VAR_DECL
848 && DECL_SECTION_NAME (decl) != NULL_TREE
849 && DECL_INITIAL (decl) == NULL_TREE
850 && DECL_COMMON (decl))
851 DECL_COMMON (decl) = 0;
853 /* Variables can't be both common and weak. */
854 if (TREE_CODE (decl) == VAR_DECL && DECL_WEAK (decl))
855 DECL_COMMON (decl) = 0;
857 x = gen_rtx_SYMBOL_REF (Pmode, name);
858 SYMBOL_REF_WEAK (x) = DECL_WEAK (decl);
859 SET_SYMBOL_REF_DECL (x, decl);
861 x = gen_rtx_MEM (DECL_MODE (decl), x);
862 if (TREE_CODE (decl) != FUNCTION_DECL)
863 set_mem_attributes (x, decl, 1);
864 SET_DECL_RTL (decl, x);
866 /* Optionally set flags or add text to the name to record information
867 such as that it is a function name.
868 If the name is changed, the macro ASM_OUTPUT_LABELREF
869 will have to know how to strip this information. */
870 targetm.encode_section_info (decl, DECL_RTL (decl), true);
872 /* Make this function static known to the mudflap runtime. */
873 if (flag_mudflap && TREE_CODE (decl) == VAR_DECL)
874 mudflap_enqueue_decl (decl);
877 /* Make the rtl for variable VAR be volatile.
878 Use this only for static variables. */
880 void
881 make_var_volatile (tree var)
883 gcc_assert (MEM_P (DECL_RTL (var)));
885 MEM_VOLATILE_P (DECL_RTL (var)) = 1;
888 /* Output a string of literal assembler code
889 for an `asm' keyword used between functions. */
891 void
892 assemble_asm (tree string)
894 app_enable ();
896 if (TREE_CODE (string) == ADDR_EXPR)
897 string = TREE_OPERAND (string, 0);
899 fprintf (asm_out_file, "\t%s\n", TREE_STRING_POINTER (string));
902 /* Record an element in the table of global destructors. SYMBOL is
903 a SYMBOL_REF of the function to be called; PRIORITY is a number
904 between 0 and MAX_INIT_PRIORITY. */
906 void
907 default_stabs_asm_out_destructor (rtx symbol ATTRIBUTE_UNUSED,
908 int priority ATTRIBUTE_UNUSED)
910 #if defined DBX_DEBUGGING_INFO || defined XCOFF_DEBUGGING_INFO
911 /* Tell GNU LD that this is part of the static destructor set.
912 This will work for any system that uses stabs, most usefully
913 aout systems. */
914 dbxout_begin_simple_stabs ("___DTOR_LIST__", 22 /* N_SETT */);
915 dbxout_stab_value_label (XSTR (symbol, 0));
916 #else
917 sorry ("global destructors not supported on this target");
918 #endif
921 void
922 default_named_section_asm_out_destructor (rtx symbol, int priority)
924 const char *section = ".dtors";
925 char buf[16];
927 /* ??? This only works reliably with the GNU linker. */
928 if (priority != DEFAULT_INIT_PRIORITY)
930 sprintf (buf, ".dtors.%.5u",
931 /* Invert the numbering so the linker puts us in the proper
932 order; constructors are run from right to left, and the
933 linker sorts in increasing order. */
934 MAX_INIT_PRIORITY - priority);
935 section = buf;
938 switch_to_section (get_section (section, SECTION_WRITE, NULL));
939 assemble_align (POINTER_SIZE);
940 assemble_integer (symbol, POINTER_SIZE / BITS_PER_UNIT, POINTER_SIZE, 1);
943 #ifdef DTORS_SECTION_ASM_OP
944 void
945 default_dtor_section_asm_out_destructor (rtx symbol,
946 int priority ATTRIBUTE_UNUSED)
948 switch_to_section (dtors_section);
949 assemble_align (POINTER_SIZE);
950 assemble_integer (symbol, POINTER_SIZE / BITS_PER_UNIT, POINTER_SIZE, 1);
952 #endif
954 /* Likewise for global constructors. */
956 void
957 default_stabs_asm_out_constructor (rtx symbol ATTRIBUTE_UNUSED,
958 int priority ATTRIBUTE_UNUSED)
960 #if defined DBX_DEBUGGING_INFO || defined XCOFF_DEBUGGING_INFO
961 /* Tell GNU LD that this is part of the static destructor set.
962 This will work for any system that uses stabs, most usefully
963 aout systems. */
964 dbxout_begin_simple_stabs ("___CTOR_LIST__", 22 /* N_SETT */);
965 dbxout_stab_value_label (XSTR (symbol, 0));
966 #else
967 sorry ("global constructors not supported on this target");
968 #endif
971 void
972 default_named_section_asm_out_constructor (rtx symbol, int priority)
974 const char *section = ".ctors";
975 char buf[16];
977 /* ??? This only works reliably with the GNU linker. */
978 if (priority != DEFAULT_INIT_PRIORITY)
980 sprintf (buf, ".ctors.%.5u",
981 /* Invert the numbering so the linker puts us in the proper
982 order; constructors are run from right to left, and the
983 linker sorts in increasing order. */
984 MAX_INIT_PRIORITY - priority);
985 section = buf;
988 switch_to_section (get_section (section, SECTION_WRITE, NULL));
989 assemble_align (POINTER_SIZE);
990 assemble_integer (symbol, POINTER_SIZE / BITS_PER_UNIT, POINTER_SIZE, 1);
993 #ifdef CTORS_SECTION_ASM_OP
994 void
995 default_ctor_section_asm_out_constructor (rtx symbol,
996 int priority ATTRIBUTE_UNUSED)
998 switch_to_section (ctors_section);
999 assemble_align (POINTER_SIZE);
1000 assemble_integer (symbol, POINTER_SIZE / BITS_PER_UNIT, POINTER_SIZE, 1);
1002 #endif
1004 /* CONSTANT_POOL_BEFORE_FUNCTION may be defined as an expression with
1005 a nonzero value if the constant pool should be output before the
1006 start of the function, or a zero value if the pool should output
1007 after the end of the function. The default is to put it before the
1008 start. */
1010 #ifndef CONSTANT_POOL_BEFORE_FUNCTION
1011 #define CONSTANT_POOL_BEFORE_FUNCTION 1
1012 #endif
1014 /* DECL is an object (either VAR_DECL or FUNCTION_DECL) which is going
1015 to be output to assembler.
1016 Set first_global_object_name and weak_global_object_name as appropriate. */
1018 void
1019 notice_global_symbol (tree decl)
1021 const char **type = &first_global_object_name;
1023 if (first_global_object_name
1024 || !TREE_PUBLIC (decl) || DECL_EXTERNAL (decl)
1025 || !DECL_NAME (decl)
1026 || (TREE_CODE (decl) != FUNCTION_DECL
1027 && (TREE_CODE (decl) != VAR_DECL
1028 || (DECL_COMMON (decl)
1029 && (DECL_INITIAL (decl) == 0
1030 || DECL_INITIAL (decl) == error_mark_node))))
1031 || !MEM_P (DECL_RTL (decl)))
1032 return;
1034 /* We win when global object is found, but it is useful to know about weak
1035 symbol as well so we can produce nicer unique names. */
1036 if (DECL_WEAK (decl) || DECL_ONE_ONLY (decl))
1037 type = &weak_global_object_name;
1039 if (!*type)
1041 const char *p;
1042 const char *name;
1043 rtx decl_rtl = DECL_RTL (decl);
1045 p = targetm.strip_name_encoding (XSTR (XEXP (decl_rtl, 0), 0));
1046 name = ggc_strdup (p);
1048 *type = name;
1052 /* Output assembler code for the constant pool of a function and associated
1053 with defining the name of the function. DECL describes the function.
1054 NAME is the function's name. For the constant pool, we use the current
1055 constant pool data. */
1057 void
1058 assemble_start_function (tree decl, const char *fnname)
1060 int align;
1061 char tmp_label[100];
1062 bool hot_label_written = false;
1064 cfun->unlikely_text_section_name = NULL;
1066 first_function_block_is_cold = false;
1067 if (flag_reorder_blocks_and_partition)
1069 ASM_GENERATE_INTERNAL_LABEL (tmp_label, "LHOTB", const_labelno);
1070 cfun->hot_section_label = ggc_strdup (tmp_label);
1071 ASM_GENERATE_INTERNAL_LABEL (tmp_label, "LCOLDB", const_labelno);
1072 cfun->cold_section_label = ggc_strdup (tmp_label);
1073 ASM_GENERATE_INTERNAL_LABEL (tmp_label, "LHOTE", const_labelno);
1074 cfun->hot_section_end_label = ggc_strdup (tmp_label);
1075 ASM_GENERATE_INTERNAL_LABEL (tmp_label, "LCOLDE", const_labelno);
1076 cfun->cold_section_end_label = ggc_strdup (tmp_label);
1077 const_labelno++;
1079 else
1081 cfun->hot_section_label = NULL;
1082 cfun->cold_section_label = NULL;
1083 cfun->hot_section_end_label = NULL;
1084 cfun->cold_section_end_label = NULL;
1087 /* The following code does not need preprocessing in the assembler. */
1089 app_disable ();
1091 if (CONSTANT_POOL_BEFORE_FUNCTION)
1092 output_constant_pool (fnname, decl);
1094 resolve_unique_section (decl, 0, flag_function_sections);
1096 /* Make sure the not and cold text (code) sections are properly
1097 aligned. This is necessary here in the case where the function
1098 has both hot and cold sections, because we don't want to re-set
1099 the alignment when the section switch happens mid-function. */
1101 if (flag_reorder_blocks_and_partition)
1103 switch_to_section (unlikely_text_section ());
1104 assemble_align (FUNCTION_BOUNDARY);
1105 ASM_OUTPUT_LABEL (asm_out_file, cfun->cold_section_label);
1107 /* When the function starts with a cold section, we need to explicitly
1108 align the hot section and write out the hot section label.
1109 But if the current function is a thunk, we do not have a CFG. */
1110 if (!current_function_is_thunk
1111 && BB_PARTITION (ENTRY_BLOCK_PTR->next_bb) == BB_COLD_PARTITION)
1113 switch_to_section (text_section);
1114 assemble_align (FUNCTION_BOUNDARY);
1115 ASM_OUTPUT_LABEL (asm_out_file, cfun->hot_section_label);
1116 hot_label_written = true;
1117 first_function_block_is_cold = true;
1120 else if (DECL_SECTION_NAME (decl))
1122 /* Calls to function_section rely on first_function_block_is_cold
1123 being accurate. The first block may be cold even if we aren't
1124 doing partitioning, if the entire function was decided by
1125 choose_function_section (predict.c) to be cold. */
1127 initialize_cold_section_name ();
1129 if (cfun->unlikely_text_section_name
1130 && strcmp (TREE_STRING_POINTER (DECL_SECTION_NAME (decl)),
1131 cfun->unlikely_text_section_name) == 0)
1132 first_function_block_is_cold = true;
1135 in_cold_section_p = first_function_block_is_cold;
1137 /* Switch to the correct text section for the start of the function. */
1139 switch_to_section (function_section (decl));
1140 if (flag_reorder_blocks_and_partition
1141 && !hot_label_written)
1142 ASM_OUTPUT_LABEL (asm_out_file, cfun->hot_section_label);
1144 /* Tell assembler to move to target machine's alignment for functions. */
1145 align = floor_log2 (FUNCTION_BOUNDARY / BITS_PER_UNIT);
1146 if (align < force_align_functions_log)
1147 align = force_align_functions_log;
1148 if (align > 0)
1150 ASM_OUTPUT_ALIGN (asm_out_file, align);
1153 /* Handle a user-specified function alignment.
1154 Note that we still need to align to FUNCTION_BOUNDARY, as above,
1155 because ASM_OUTPUT_MAX_SKIP_ALIGN might not do any alignment at all. */
1156 if (align_functions_log > align
1157 && cfun->function_frequency != FUNCTION_FREQUENCY_UNLIKELY_EXECUTED)
1159 #ifdef ASM_OUTPUT_MAX_SKIP_ALIGN
1160 ASM_OUTPUT_MAX_SKIP_ALIGN (asm_out_file,
1161 align_functions_log, align_functions - 1);
1162 #else
1163 ASM_OUTPUT_ALIGN (asm_out_file, align_functions_log);
1164 #endif
1167 #ifdef ASM_OUTPUT_FUNCTION_PREFIX
1168 ASM_OUTPUT_FUNCTION_PREFIX (asm_out_file, fnname);
1169 #endif
1171 (*debug_hooks->begin_function) (decl);
1173 /* Make function name accessible from other files, if appropriate. */
1175 if (TREE_PUBLIC (decl))
1177 notice_global_symbol (decl);
1179 globalize_decl (decl);
1181 maybe_assemble_visibility (decl);
1184 if (DECL_PRESERVE_P (decl))
1185 targetm.asm_out.mark_decl_preserved (fnname);
1187 /* Do any machine/system dependent processing of the function name. */
1188 #ifdef ASM_DECLARE_FUNCTION_NAME
1189 ASM_DECLARE_FUNCTION_NAME (asm_out_file, fnname, current_function_decl);
1190 #else
1191 /* Standard thing is just output label for the function. */
1192 ASM_OUTPUT_LABEL (asm_out_file, fnname);
1193 #endif /* ASM_DECLARE_FUNCTION_NAME */
1196 /* Output assembler code associated with defining the size of the
1197 function. DECL describes the function. NAME is the function's name. */
1199 void
1200 assemble_end_function (tree decl, const char *fnname)
1202 #ifdef ASM_DECLARE_FUNCTION_SIZE
1203 /* We could have switched section in the middle of the function. */
1204 if (flag_reorder_blocks_and_partition)
1205 switch_to_section (function_section (decl));
1206 ASM_DECLARE_FUNCTION_SIZE (asm_out_file, fnname, decl);
1207 #endif
1208 if (! CONSTANT_POOL_BEFORE_FUNCTION)
1210 output_constant_pool (fnname, decl);
1211 switch_to_section (function_section (decl)); /* need to switch back */
1213 /* Output labels for end of hot/cold text sections (to be used by
1214 debug info.) */
1215 if (flag_reorder_blocks_and_partition)
1217 section *save_text_section;
1219 save_text_section = in_section;
1220 switch_to_section (unlikely_text_section ());
1221 ASM_OUTPUT_LABEL (asm_out_file, cfun->cold_section_end_label);
1222 if (first_function_block_is_cold)
1223 switch_to_section (text_section);
1224 else
1225 switch_to_section (function_section (decl));
1226 ASM_OUTPUT_LABEL (asm_out_file, cfun->hot_section_end_label);
1227 switch_to_section (save_text_section);
1231 /* Assemble code to leave SIZE bytes of zeros. */
1233 void
1234 assemble_zeros (unsigned HOST_WIDE_INT size)
1236 /* Do no output if -fsyntax-only. */
1237 if (flag_syntax_only)
1238 return;
1240 #ifdef ASM_NO_SKIP_IN_TEXT
1241 /* The `space' pseudo in the text section outputs nop insns rather than 0s,
1242 so we must output 0s explicitly in the text section. */
1243 if (ASM_NO_SKIP_IN_TEXT && (in_section->common.flags & SECTION_CODE) != 0)
1245 unsigned HOST_WIDE_INT i;
1246 for (i = 0; i < size; i++)
1247 assemble_integer (const0_rtx, 1, BITS_PER_UNIT, 1);
1249 else
1250 #endif
1251 if (size > 0)
1252 ASM_OUTPUT_SKIP (asm_out_file, size);
1255 /* Assemble an alignment pseudo op for an ALIGN-bit boundary. */
1257 void
1258 assemble_align (int align)
1260 if (align > BITS_PER_UNIT)
1262 ASM_OUTPUT_ALIGN (asm_out_file, floor_log2 (align / BITS_PER_UNIT));
1266 /* Assemble a string constant with the specified C string as contents. */
1268 void
1269 assemble_string (const char *p, int size)
1271 int pos = 0;
1272 int maximum = 2000;
1274 /* If the string is very long, split it up. */
1276 while (pos < size)
1278 int thissize = size - pos;
1279 if (thissize > maximum)
1280 thissize = maximum;
1282 ASM_OUTPUT_ASCII (asm_out_file, p, thissize);
1284 pos += thissize;
1285 p += thissize;
1290 #if defined ASM_OUTPUT_ALIGNED_DECL_LOCAL
1291 #define ASM_EMIT_LOCAL(decl, name, size, rounded) \
1292 ASM_OUTPUT_ALIGNED_DECL_LOCAL (asm_out_file, decl, name, size, DECL_ALIGN (decl))
1293 #else
1294 #if defined ASM_OUTPUT_ALIGNED_LOCAL
1295 #define ASM_EMIT_LOCAL(decl, name, size, rounded) \
1296 ASM_OUTPUT_ALIGNED_LOCAL (asm_out_file, name, size, DECL_ALIGN (decl))
1297 #else
1298 #define ASM_EMIT_LOCAL(decl, name, size, rounded) \
1299 ASM_OUTPUT_LOCAL (asm_out_file, name, size, rounded)
1300 #endif
1301 #endif
1303 #if defined ASM_OUTPUT_ALIGNED_BSS
1304 #define ASM_EMIT_BSS(decl, name, size, rounded) \
1305 ASM_OUTPUT_ALIGNED_BSS (asm_out_file, decl, name, size, DECL_ALIGN (decl))
1306 #else
1307 #if defined ASM_OUTPUT_BSS
1308 #define ASM_EMIT_BSS(decl, name, size, rounded) \
1309 ASM_OUTPUT_BSS (asm_out_file, decl, name, size, rounded)
1310 #else
1311 #undef ASM_EMIT_BSS
1312 #endif
1313 #endif
1315 #if defined ASM_OUTPUT_ALIGNED_DECL_COMMON
1316 #define ASM_EMIT_COMMON(decl, name, size, rounded) \
1317 ASM_OUTPUT_ALIGNED_DECL_COMMON (asm_out_file, decl, name, size, DECL_ALIGN (decl))
1318 #else
1319 #if defined ASM_OUTPUT_ALIGNED_COMMON
1320 #define ASM_EMIT_COMMON(decl, name, size, rounded) \
1321 ASM_OUTPUT_ALIGNED_COMMON (asm_out_file, name, size, DECL_ALIGN (decl))
1322 #else
1323 #define ASM_EMIT_COMMON(decl, name, size, rounded) \
1324 ASM_OUTPUT_COMMON (asm_out_file, name, size, rounded)
1325 #endif
1326 #endif
1328 static bool
1329 asm_emit_uninitialised (tree decl, const char *name,
1330 unsigned HOST_WIDE_INT size ATTRIBUTE_UNUSED,
1331 unsigned HOST_WIDE_INT rounded ATTRIBUTE_UNUSED)
1333 enum
1335 asm_dest_common,
1336 asm_dest_bss,
1337 asm_dest_local
1339 destination = asm_dest_local;
1341 /* ??? We should handle .bss via select_section mechanisms rather than
1342 via special target hooks. That would eliminate this special case. */
1343 if (TREE_PUBLIC (decl))
1345 if (!DECL_COMMON (decl))
1346 #ifdef ASM_EMIT_BSS
1347 destination = asm_dest_bss;
1348 #else
1349 return false;
1350 #endif
1351 else
1352 destination = asm_dest_common;
1355 if (destination != asm_dest_common)
1357 resolve_unique_section (decl, 0, flag_data_sections);
1358 /* Custom sections don't belong here. */
1359 if (DECL_SECTION_NAME (decl))
1360 return false;
1363 if (destination == asm_dest_bss)
1364 globalize_decl (decl);
1366 if (flag_shared_data)
1368 switch (destination)
1370 #ifdef ASM_OUTPUT_SHARED_BSS
1371 case asm_dest_bss:
1372 ASM_OUTPUT_SHARED_BSS (asm_out_file, decl, name, size, rounded);
1373 return;
1374 #endif
1375 #ifdef ASM_OUTPUT_SHARED_COMMON
1376 case asm_dest_common:
1377 ASM_OUTPUT_SHARED_COMMON (asm_out_file, name, size, rounded);
1378 return;
1379 #endif
1380 #ifdef ASM_OUTPUT_SHARED_LOCAL
1381 case asm_dest_local:
1382 ASM_OUTPUT_SHARED_LOCAL (asm_out_file, name, size, rounded);
1383 return;
1384 #endif
1385 default:
1386 break;
1390 switch (destination)
1392 #ifdef ASM_EMIT_BSS
1393 case asm_dest_bss:
1394 ASM_EMIT_BSS (decl, name, size, rounded);
1395 break;
1396 #endif
1397 case asm_dest_common:
1398 ASM_EMIT_COMMON (decl, name, size, rounded);
1399 break;
1400 case asm_dest_local:
1401 ASM_EMIT_LOCAL (decl, name, size, rounded);
1402 break;
1403 default:
1404 gcc_unreachable ();
1407 return true;
1410 /* Assemble everything that is needed for a variable or function declaration.
1411 Not used for automatic variables, and not used for function definitions.
1412 Should not be called for variables of incomplete structure type.
1414 TOP_LEVEL is nonzero if this variable has file scope.
1415 AT_END is nonzero if this is the special handling, at end of compilation,
1416 to define things that have had only tentative definitions.
1417 DONT_OUTPUT_DATA if nonzero means don't actually output the
1418 initial value (that will be done by the caller). */
1420 void
1421 assemble_variable (tree decl, int top_level ATTRIBUTE_UNUSED,
1422 int at_end ATTRIBUTE_UNUSED, int dont_output_data)
1424 const char *name;
1425 unsigned int align;
1426 int reloc = 0;
1427 rtx decl_rtl;
1429 if (lang_hooks.decls.prepare_assemble_variable)
1430 lang_hooks.decls.prepare_assemble_variable (decl);
1432 last_assemble_variable_decl = 0;
1434 /* Normally no need to say anything here for external references,
1435 since assemble_external is called by the language-specific code
1436 when a declaration is first seen. */
1438 if (DECL_EXTERNAL (decl))
1439 return;
1441 /* Output no assembler code for a function declaration.
1442 Only definitions of functions output anything. */
1444 if (TREE_CODE (decl) == FUNCTION_DECL)
1445 return;
1447 /* Do nothing for global register variables. */
1448 if (DECL_RTL_SET_P (decl) && REG_P (DECL_RTL (decl)))
1450 TREE_ASM_WRITTEN (decl) = 1;
1451 return;
1454 /* If type was incomplete when the variable was declared,
1455 see if it is complete now. */
1457 if (DECL_SIZE (decl) == 0)
1458 layout_decl (decl, 0);
1460 /* Still incomplete => don't allocate it; treat the tentative defn
1461 (which is what it must have been) as an `extern' reference. */
1463 if (!dont_output_data && DECL_SIZE (decl) == 0)
1465 error ("storage size of %q+D isn%'t known", decl);
1466 TREE_ASM_WRITTEN (decl) = 1;
1467 return;
1470 /* The first declaration of a variable that comes through this function
1471 decides whether it is global (in C, has external linkage)
1472 or local (in C, has internal linkage). So do nothing more
1473 if this function has already run. */
1475 if (TREE_ASM_WRITTEN (decl))
1476 return;
1478 /* Make sure targetm.encode_section_info is invoked before we set
1479 ASM_WRITTEN. */
1480 decl_rtl = DECL_RTL (decl);
1482 TREE_ASM_WRITTEN (decl) = 1;
1484 /* Do no output if -fsyntax-only. */
1485 if (flag_syntax_only)
1486 return;
1488 app_disable ();
1490 if (! dont_output_data
1491 && ! host_integerp (DECL_SIZE_UNIT (decl), 1))
1493 error ("size of variable %q+D is too large", decl);
1494 return;
1497 name = XSTR (XEXP (decl_rtl, 0), 0);
1498 if (TREE_PUBLIC (decl) && DECL_NAME (decl))
1499 notice_global_symbol (decl);
1501 /* Compute the alignment of this data. */
1503 align = DECL_ALIGN (decl);
1505 /* In the case for initialing an array whose length isn't specified,
1506 where we have not yet been able to do the layout,
1507 figure out the proper alignment now. */
1508 if (dont_output_data && DECL_SIZE (decl) == 0
1509 && TREE_CODE (TREE_TYPE (decl)) == ARRAY_TYPE)
1510 align = MAX (align, TYPE_ALIGN (TREE_TYPE (TREE_TYPE (decl))));
1512 /* Some object file formats have a maximum alignment which they support.
1513 In particular, a.out format supports a maximum alignment of 4. */
1514 if (align > MAX_OFILE_ALIGNMENT)
1516 warning (0, "alignment of %q+D is greater than maximum object "
1517 "file alignment. Using %d", decl,
1518 MAX_OFILE_ALIGNMENT/BITS_PER_UNIT);
1519 align = MAX_OFILE_ALIGNMENT;
1522 /* On some machines, it is good to increase alignment sometimes. */
1523 if (! DECL_USER_ALIGN (decl))
1525 #ifdef DATA_ALIGNMENT
1526 align = DATA_ALIGNMENT (TREE_TYPE (decl), align);
1527 #endif
1528 #ifdef CONSTANT_ALIGNMENT
1529 if (DECL_INITIAL (decl) != 0 && DECL_INITIAL (decl) != error_mark_node)
1530 align = CONSTANT_ALIGNMENT (DECL_INITIAL (decl), align);
1531 #endif
1534 /* Reset the alignment in case we have made it tighter, so we can benefit
1535 from it in get_pointer_alignment. */
1536 DECL_ALIGN (decl) = align;
1537 set_mem_align (decl_rtl, align);
1539 if (TREE_PUBLIC (decl))
1540 maybe_assemble_visibility (decl);
1542 if (DECL_PRESERVE_P (decl))
1543 targetm.asm_out.mark_decl_preserved (name);
1545 /* Handle uninitialized definitions. */
1547 /* If the decl has been given an explicit section name, then it
1548 isn't common, and shouldn't be handled as such. */
1549 if (DECL_SECTION_NAME (decl) || dont_output_data)
1551 else if (DECL_THREAD_LOCAL_P (decl))
1553 if (DECL_COMMON (decl))
1555 #ifdef ASM_OUTPUT_TLS_COMMON
1556 unsigned HOST_WIDE_INT size;
1558 size = tree_low_cst (DECL_SIZE_UNIT (decl), 1);
1559 ASM_OUTPUT_TLS_COMMON (asm_out_file, decl, name, size);
1560 return;
1561 #else
1562 sorry ("thread-local COMMON data not implemented");
1563 #endif
1566 else if (DECL_INITIAL (decl) == 0
1567 || DECL_INITIAL (decl) == error_mark_node
1568 || (flag_zero_initialized_in_bss
1569 /* Leave constant zeroes in .rodata so they can be shared. */
1570 && !TREE_READONLY (decl)
1571 && initializer_zerop (DECL_INITIAL (decl))))
1573 unsigned HOST_WIDE_INT size = tree_low_cst (DECL_SIZE_UNIT (decl), 1);
1574 unsigned HOST_WIDE_INT rounded = size;
1576 /* Don't allocate zero bytes of common,
1577 since that means "undefined external" in the linker. */
1578 if (size == 0)
1579 rounded = 1;
1581 /* Round size up to multiple of BIGGEST_ALIGNMENT bits
1582 so that each uninitialized object starts on such a boundary. */
1583 rounded += (BIGGEST_ALIGNMENT / BITS_PER_UNIT) - 1;
1584 rounded = (rounded / (BIGGEST_ALIGNMENT / BITS_PER_UNIT)
1585 * (BIGGEST_ALIGNMENT / BITS_PER_UNIT));
1587 #if !defined(ASM_OUTPUT_ALIGNED_COMMON) && !defined(ASM_OUTPUT_ALIGNED_DECL_COMMON) && !defined(ASM_OUTPUT_ALIGNED_BSS)
1588 if ((unsigned HOST_WIDE_INT) DECL_ALIGN_UNIT (decl) > rounded)
1589 warning (0, "requested alignment for %q+D is greater than "
1590 "implemented alignment of %wu", decl, rounded);
1591 #endif
1593 /* If the target cannot output uninitialized but not common global data
1594 in .bss, then we have to use .data, so fall through. */
1595 if (asm_emit_uninitialised (decl, name, size, rounded))
1596 return;
1599 /* Handle initialized definitions.
1600 Also handle uninitialized global definitions if -fno-common and the
1601 target doesn't support ASM_OUTPUT_BSS. */
1603 /* First make the assembler name(s) global if appropriate. */
1604 if (TREE_PUBLIC (decl) && DECL_NAME (decl))
1605 globalize_decl (decl);
1607 /* Output any data that we will need to use the address of. */
1608 if (DECL_INITIAL (decl) == error_mark_node)
1609 reloc = contains_pointers_p (TREE_TYPE (decl)) ? 3 : 0;
1610 else if (DECL_INITIAL (decl))
1612 reloc = compute_reloc_for_constant (DECL_INITIAL (decl));
1613 output_addressed_constants (DECL_INITIAL (decl));
1616 /* Switch to the appropriate section. */
1617 resolve_unique_section (decl, reloc, flag_data_sections);
1618 variable_section (decl, reloc);
1620 /* dbxout.c needs to know this. */
1621 if (in_section && (in_section->common.flags & SECTION_CODE) != 0)
1622 DECL_IN_TEXT_SECTION (decl) = 1;
1624 /* Output the alignment of this data. */
1625 if (align > BITS_PER_UNIT)
1626 ASM_OUTPUT_ALIGN (asm_out_file, floor_log2 (DECL_ALIGN_UNIT (decl)));
1628 /* Do any machine/system dependent processing of the object. */
1629 #ifdef ASM_DECLARE_OBJECT_NAME
1630 last_assemble_variable_decl = decl;
1631 ASM_DECLARE_OBJECT_NAME (asm_out_file, name, decl);
1632 #else
1633 /* Standard thing is just output label for the object. */
1634 ASM_OUTPUT_LABEL (asm_out_file, name);
1635 #endif /* ASM_DECLARE_OBJECT_NAME */
1637 if (!dont_output_data)
1639 if (DECL_INITIAL (decl)
1640 && DECL_INITIAL (decl) != error_mark_node
1641 && !initializer_zerop (DECL_INITIAL (decl)))
1642 /* Output the actual data. */
1643 output_constant (DECL_INITIAL (decl),
1644 tree_low_cst (DECL_SIZE_UNIT (decl), 1),
1645 align);
1646 else
1647 /* Leave space for it. */
1648 assemble_zeros (tree_low_cst (DECL_SIZE_UNIT (decl), 1));
1652 /* Return 1 if type TYPE contains any pointers. */
1654 static int
1655 contains_pointers_p (tree type)
1657 switch (TREE_CODE (type))
1659 case POINTER_TYPE:
1660 case REFERENCE_TYPE:
1661 /* I'm not sure whether OFFSET_TYPE needs this treatment,
1662 so I'll play safe and return 1. */
1663 case OFFSET_TYPE:
1664 return 1;
1666 case RECORD_TYPE:
1667 case UNION_TYPE:
1668 case QUAL_UNION_TYPE:
1670 tree fields;
1671 /* For a type that has fields, see if the fields have pointers. */
1672 for (fields = TYPE_FIELDS (type); fields; fields = TREE_CHAIN (fields))
1673 if (TREE_CODE (fields) == FIELD_DECL
1674 && contains_pointers_p (TREE_TYPE (fields)))
1675 return 1;
1676 return 0;
1679 case ARRAY_TYPE:
1680 /* An array type contains pointers if its element type does. */
1681 return contains_pointers_p (TREE_TYPE (type));
1683 default:
1684 return 0;
1688 /* In unit-at-a-time mode, we delay assemble_external processing until
1689 the compilation unit is finalized. This is the best we can do for
1690 right now (i.e. stage 3 of GCC 4.0) - the right thing is to delay
1691 it all the way to final. See PR 17982 for further discussion. */
1692 static GTY(()) tree pending_assemble_externals;
1694 #ifdef ASM_OUTPUT_EXTERNAL
1695 /* True if DECL is a function decl for which no out-of-line copy exists.
1696 It is assumed that DECL's assembler name has been set. */
1698 static bool
1699 incorporeal_function_p (tree decl)
1701 if (TREE_CODE (decl) == FUNCTION_DECL && DECL_BUILT_IN (decl))
1703 const char *name;
1705 if (DECL_BUILT_IN_CLASS (decl) == BUILT_IN_NORMAL
1706 && DECL_FUNCTION_CODE (decl) == BUILT_IN_ALLOCA)
1707 return true;
1709 name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
1710 if (strncmp (name, "__builtin_", strlen ("__builtin_")) == 0)
1711 return true;
1713 return false;
1716 /* Actually do the tests to determine if this is necessary, and invoke
1717 ASM_OUTPUT_EXTERNAL. */
1718 static void
1719 assemble_external_real (tree decl)
1721 rtx rtl = DECL_RTL (decl);
1723 if (MEM_P (rtl) && GET_CODE (XEXP (rtl, 0)) == SYMBOL_REF
1724 && !SYMBOL_REF_USED (XEXP (rtl, 0))
1725 && !incorporeal_function_p (decl))
1727 /* Some systems do require some output. */
1728 SYMBOL_REF_USED (XEXP (rtl, 0)) = 1;
1729 ASM_OUTPUT_EXTERNAL (asm_out_file, decl, XSTR (XEXP (rtl, 0), 0));
1732 #endif
1734 void
1735 process_pending_assemble_externals (void)
1737 #ifdef ASM_OUTPUT_EXTERNAL
1738 tree list;
1739 for (list = pending_assemble_externals; list; list = TREE_CHAIN (list))
1740 assemble_external_real (TREE_VALUE (list));
1742 pending_assemble_externals = 0;
1743 #endif
1746 /* Output something to declare an external symbol to the assembler.
1747 (Most assemblers don't need this, so we normally output nothing.)
1748 Do nothing if DECL is not external. */
1750 void
1751 assemble_external (tree decl ATTRIBUTE_UNUSED)
1753 /* Because most platforms do not define ASM_OUTPUT_EXTERNAL, the
1754 main body of this code is only rarely exercised. To provide some
1755 testing, on all platforms, we make sure that the ASM_OUT_FILE is
1756 open. If it's not, we should not be calling this function. */
1757 gcc_assert (asm_out_file);
1759 #ifdef ASM_OUTPUT_EXTERNAL
1760 if (!DECL_P (decl) || !DECL_EXTERNAL (decl) || !TREE_PUBLIC (decl))
1761 return;
1763 if (flag_unit_at_a_time)
1764 pending_assemble_externals = tree_cons (0, decl,
1765 pending_assemble_externals);
1766 else
1767 assemble_external_real (decl);
1768 #endif
1771 /* Similar, for calling a library function FUN. */
1773 void
1774 assemble_external_libcall (rtx fun)
1776 /* Declare library function name external when first used, if nec. */
1777 if (! SYMBOL_REF_USED (fun))
1779 SYMBOL_REF_USED (fun) = 1;
1780 targetm.asm_out.external_libcall (fun);
1784 /* Assemble a label named NAME. */
1786 void
1787 assemble_label (const char *name)
1789 ASM_OUTPUT_LABEL (asm_out_file, name);
1792 /* Set the symbol_referenced flag for ID. */
1793 void
1794 mark_referenced (tree id)
1796 TREE_SYMBOL_REFERENCED (id) = 1;
1799 /* Set the symbol_referenced flag for DECL and notify callgraph. */
1800 void
1801 mark_decl_referenced (tree decl)
1803 if (TREE_CODE (decl) == FUNCTION_DECL)
1805 /* Extern inline functions don't become needed when referenced.
1806 If we know a method will be emitted in other TU and no new
1807 functions can be marked reachable, just use the external
1808 definition. */
1809 struct cgraph_node *node = cgraph_node (decl);
1810 if (!DECL_EXTERNAL (decl)
1811 && (!node->local.vtable_method || !cgraph_global_info_ready
1812 || !node->local.finalized))
1813 cgraph_mark_needed_node (node);
1815 else if (TREE_CODE (decl) == VAR_DECL)
1817 struct cgraph_varpool_node *node = cgraph_varpool_node (decl);
1818 cgraph_varpool_mark_needed_node (node);
1819 /* C++ frontend use mark_decl_references to force COMDAT variables
1820 to be output that might appear dead otherwise. */
1821 node->force_output = true;
1823 /* else do nothing - we can get various sorts of CST nodes here,
1824 which do not need to be marked. */
1828 /* Follow the IDENTIFIER_TRANSPARENT_ALIAS chain starting at *ALIAS
1829 until we find an identifier that is not itself a transparent alias.
1830 Modify the alias passed to it by reference (and all aliases on the
1831 way to the ultimate target), such that they do not have to be
1832 followed again, and return the ultimate target of the alias
1833 chain. */
1835 static inline tree
1836 ultimate_transparent_alias_target (tree *alias)
1838 tree target = *alias;
1840 if (IDENTIFIER_TRANSPARENT_ALIAS (target))
1842 gcc_assert (TREE_CHAIN (target));
1843 target = ultimate_transparent_alias_target (&TREE_CHAIN (target));
1844 gcc_assert (! IDENTIFIER_TRANSPARENT_ALIAS (target)
1845 && ! TREE_CHAIN (target));
1846 *alias = target;
1849 return target;
1852 /* Output to FILE (an assembly file) a reference to NAME. If NAME
1853 starts with a *, the rest of NAME is output verbatim. Otherwise
1854 NAME is transformed in a target-specific way (usually by the
1855 addition of an underscore). */
1857 void
1858 assemble_name_raw (FILE *file, const char *name)
1860 if (name[0] == '*')
1861 fputs (&name[1], file);
1862 else
1863 ASM_OUTPUT_LABELREF (file, name);
1866 /* Like assemble_name_raw, but should be used when NAME might refer to
1867 an entity that is also represented as a tree (like a function or
1868 variable). If NAME does refer to such an entity, that entity will
1869 be marked as referenced. */
1871 void
1872 assemble_name (FILE *file, const char *name)
1874 const char *real_name;
1875 tree id;
1877 real_name = targetm.strip_name_encoding (name);
1879 id = maybe_get_identifier (real_name);
1880 if (id)
1882 tree id_orig = id;
1884 mark_referenced (id);
1885 ultimate_transparent_alias_target (&id);
1886 if (id != id_orig)
1887 name = IDENTIFIER_POINTER (id);
1888 gcc_assert (! TREE_CHAIN (id));
1891 assemble_name_raw (file, name);
1894 /* Allocate SIZE bytes writable static space with a gensym name
1895 and return an RTX to refer to its address. */
1898 assemble_static_space (unsigned HOST_WIDE_INT size)
1900 char name[12];
1901 const char *namestring;
1902 rtx x;
1904 #if 0
1905 if (flag_shared_data)
1906 switch_to_section (data_section);
1907 #endif
1909 ASM_GENERATE_INTERNAL_LABEL (name, "LF", const_labelno);
1910 ++const_labelno;
1911 namestring = ggc_strdup (name);
1913 x = gen_rtx_SYMBOL_REF (Pmode, namestring);
1914 SYMBOL_REF_FLAGS (x) = SYMBOL_FLAG_LOCAL;
1916 #ifdef ASM_OUTPUT_ALIGNED_DECL_LOCAL
1917 ASM_OUTPUT_ALIGNED_DECL_LOCAL (asm_out_file, NULL_TREE, name, size,
1918 BIGGEST_ALIGNMENT);
1919 #else
1920 #ifdef ASM_OUTPUT_ALIGNED_LOCAL
1921 ASM_OUTPUT_ALIGNED_LOCAL (asm_out_file, name, size, BIGGEST_ALIGNMENT);
1922 #else
1924 /* Round size up to multiple of BIGGEST_ALIGNMENT bits
1925 so that each uninitialized object starts on such a boundary. */
1926 /* Variable `rounded' might or might not be used in ASM_OUTPUT_LOCAL. */
1927 unsigned HOST_WIDE_INT rounded ATTRIBUTE_UNUSED
1928 = ((size + (BIGGEST_ALIGNMENT / BITS_PER_UNIT) - 1)
1929 / (BIGGEST_ALIGNMENT / BITS_PER_UNIT)
1930 * (BIGGEST_ALIGNMENT / BITS_PER_UNIT));
1931 ASM_OUTPUT_LOCAL (asm_out_file, name, size, rounded);
1933 #endif
1934 #endif
1935 return x;
1938 /* Assemble the static constant template for function entry trampolines.
1939 This is done at most once per compilation.
1940 Returns an RTX for the address of the template. */
1942 static GTY(()) rtx initial_trampoline;
1944 #ifdef TRAMPOLINE_TEMPLATE
1946 assemble_trampoline_template (void)
1948 char label[256];
1949 const char *name;
1950 int align;
1951 rtx symbol;
1953 if (initial_trampoline)
1954 return initial_trampoline;
1956 /* By default, put trampoline templates in read-only data section. */
1958 #ifdef TRAMPOLINE_SECTION
1959 switch_to_section (TRAMPOLINE_SECTION);
1960 #else
1961 switch_to_section (readonly_data_section);
1962 #endif
1964 /* Write the assembler code to define one. */
1965 align = floor_log2 (TRAMPOLINE_ALIGNMENT / BITS_PER_UNIT);
1966 if (align > 0)
1968 ASM_OUTPUT_ALIGN (asm_out_file, align);
1971 targetm.asm_out.internal_label (asm_out_file, "LTRAMP", 0);
1972 TRAMPOLINE_TEMPLATE (asm_out_file);
1974 /* Record the rtl to refer to it. */
1975 ASM_GENERATE_INTERNAL_LABEL (label, "LTRAMP", 0);
1976 name = ggc_strdup (label);
1977 symbol = gen_rtx_SYMBOL_REF (Pmode, name);
1978 SYMBOL_REF_FLAGS (symbol) = SYMBOL_FLAG_LOCAL;
1980 initial_trampoline = gen_rtx_MEM (BLKmode, symbol);
1981 set_mem_align (initial_trampoline, TRAMPOLINE_ALIGNMENT);
1983 return initial_trampoline;
1985 #endif
1987 /* A and B are either alignments or offsets. Return the minimum alignment
1988 that may be assumed after adding the two together. */
1990 static inline unsigned
1991 min_align (unsigned int a, unsigned int b)
1993 return (a | b) & -(a | b);
1996 /* Return the assembler directive for creating a given kind of integer
1997 object. SIZE is the number of bytes in the object and ALIGNED_P
1998 indicates whether it is known to be aligned. Return NULL if the
1999 assembly dialect has no such directive.
2001 The returned string should be printed at the start of a new line and
2002 be followed immediately by the object's initial value. */
2004 const char *
2005 integer_asm_op (int size, int aligned_p)
2007 struct asm_int_op *ops;
2009 if (aligned_p)
2010 ops = &targetm.asm_out.aligned_op;
2011 else
2012 ops = &targetm.asm_out.unaligned_op;
2014 switch (size)
2016 case 1:
2017 return targetm.asm_out.byte_op;
2018 case 2:
2019 return ops->hi;
2020 case 4:
2021 return ops->si;
2022 case 8:
2023 return ops->di;
2024 case 16:
2025 return ops->ti;
2026 default:
2027 return NULL;
2031 /* Use directive OP to assemble an integer object X. Print OP at the
2032 start of the line, followed immediately by the value of X. */
2034 void
2035 assemble_integer_with_op (const char *op, rtx x)
2037 fputs (op, asm_out_file);
2038 output_addr_const (asm_out_file, x);
2039 fputc ('\n', asm_out_file);
2042 /* The default implementation of the asm_out.integer target hook. */
2044 bool
2045 default_assemble_integer (rtx x ATTRIBUTE_UNUSED,
2046 unsigned int size ATTRIBUTE_UNUSED,
2047 int aligned_p ATTRIBUTE_UNUSED)
2049 const char *op = integer_asm_op (size, aligned_p);
2050 /* Avoid GAS bugs for large values. Specifically negative values whose
2051 absolute value fits in a bfd_vma, but not in a bfd_signed_vma. */
2052 if (size > UNITS_PER_WORD && size > POINTER_SIZE / BITS_PER_UNIT)
2053 return false;
2054 return op && (assemble_integer_with_op (op, x), true);
2057 /* Assemble the integer constant X into an object of SIZE bytes. ALIGN is
2058 the alignment of the integer in bits. Return 1 if we were able to output
2059 the constant, otherwise 0. We must be able to output the constant,
2060 if FORCE is nonzero. */
2062 bool
2063 assemble_integer (rtx x, unsigned int size, unsigned int align, int force)
2065 int aligned_p;
2067 aligned_p = (align >= MIN (size * BITS_PER_UNIT, BIGGEST_ALIGNMENT));
2069 /* See if the target hook can handle this kind of object. */
2070 if (targetm.asm_out.integer (x, size, aligned_p))
2071 return true;
2073 /* If the object is a multi-byte one, try splitting it up. Split
2074 it into words it if is multi-word, otherwise split it into bytes. */
2075 if (size > 1)
2077 enum machine_mode omode, imode;
2078 unsigned int subalign;
2079 unsigned int subsize, i;
2081 subsize = size > UNITS_PER_WORD? UNITS_PER_WORD : 1;
2082 subalign = MIN (align, subsize * BITS_PER_UNIT);
2083 omode = mode_for_size (subsize * BITS_PER_UNIT, MODE_INT, 0);
2084 imode = mode_for_size (size * BITS_PER_UNIT, MODE_INT, 0);
2086 for (i = 0; i < size; i += subsize)
2088 rtx partial = simplify_subreg (omode, x, imode, i);
2089 if (!partial || !assemble_integer (partial, subsize, subalign, 0))
2090 break;
2092 if (i == size)
2093 return true;
2095 /* If we've printed some of it, but not all of it, there's no going
2096 back now. */
2097 gcc_assert (!i);
2100 gcc_assert (!force);
2102 return false;
2105 void
2106 assemble_real (REAL_VALUE_TYPE d, enum machine_mode mode, unsigned int align)
2108 long data[4] = {0, 0, 0, 0};
2109 int i;
2110 int bitsize, nelts, nunits, units_per;
2112 /* This is hairy. We have a quantity of known size. real_to_target
2113 will put it into an array of *host* longs, 32 bits per element
2114 (even if long is more than 32 bits). We need to determine the
2115 number of array elements that are occupied (nelts) and the number
2116 of *target* min-addressable units that will be occupied in the
2117 object file (nunits). We cannot assume that 32 divides the
2118 mode's bitsize (size * BITS_PER_UNIT) evenly.
2120 size * BITS_PER_UNIT is used here to make sure that padding bits
2121 (which might appear at either end of the value; real_to_target
2122 will include the padding bits in its output array) are included. */
2124 nunits = GET_MODE_SIZE (mode);
2125 bitsize = nunits * BITS_PER_UNIT;
2126 nelts = CEIL (bitsize, 32);
2127 units_per = 32 / BITS_PER_UNIT;
2129 real_to_target (data, &d, mode);
2131 /* Put out the first word with the specified alignment. */
2132 assemble_integer (GEN_INT (data[0]), MIN (nunits, units_per), align, 1);
2133 nunits -= units_per;
2135 /* Subsequent words need only 32-bit alignment. */
2136 align = min_align (align, 32);
2138 for (i = 1; i < nelts; i++)
2140 assemble_integer (GEN_INT (data[i]), MIN (nunits, units_per), align, 1);
2141 nunits -= units_per;
2145 /* Given an expression EXP with a constant value,
2146 reduce it to the sum of an assembler symbol and an integer.
2147 Store them both in the structure *VALUE.
2148 EXP must be reducible. */
2150 struct addr_const GTY(())
2152 rtx base;
2153 HOST_WIDE_INT offset;
2156 static void
2157 decode_addr_const (tree exp, struct addr_const *value)
2159 tree target = TREE_OPERAND (exp, 0);
2160 int offset = 0;
2161 rtx x;
2163 while (1)
2165 if (TREE_CODE (target) == COMPONENT_REF
2166 && host_integerp (byte_position (TREE_OPERAND (target, 1)), 0))
2169 offset += int_byte_position (TREE_OPERAND (target, 1));
2170 target = TREE_OPERAND (target, 0);
2172 else if (TREE_CODE (target) == ARRAY_REF
2173 || TREE_CODE (target) == ARRAY_RANGE_REF)
2175 offset += (tree_low_cst (TYPE_SIZE_UNIT (TREE_TYPE (target)), 1)
2176 * tree_low_cst (TREE_OPERAND (target, 1), 0));
2177 target = TREE_OPERAND (target, 0);
2179 else
2180 break;
2183 switch (TREE_CODE (target))
2185 case VAR_DECL:
2186 case FUNCTION_DECL:
2187 x = DECL_RTL (target);
2188 break;
2190 case LABEL_DECL:
2191 x = gen_rtx_MEM (FUNCTION_MODE,
2192 gen_rtx_LABEL_REF (Pmode, force_label_rtx (target)));
2193 break;
2195 case REAL_CST:
2196 case STRING_CST:
2197 case COMPLEX_CST:
2198 case CONSTRUCTOR:
2199 case INTEGER_CST:
2200 x = output_constant_def (target, 1);
2201 break;
2203 default:
2204 gcc_unreachable ();
2207 gcc_assert (MEM_P (x));
2208 x = XEXP (x, 0);
2210 value->base = x;
2211 value->offset = offset;
2214 /* Uniquize all constants that appear in memory.
2215 Each constant in memory thus far output is recorded
2216 in `const_desc_table'. */
2218 struct constant_descriptor_tree GTY(())
2220 /* A MEM for the constant. */
2221 rtx rtl;
2223 /* The value of the constant. */
2224 tree value;
2226 /* Hash of value. Computing the hash from value each time
2227 hashfn is called can't work properly, as that means recursive
2228 use of the hash table during hash table expansion. */
2229 hashval_t hash;
2232 static GTY((param_is (struct constant_descriptor_tree)))
2233 htab_t const_desc_htab;
2235 static struct constant_descriptor_tree * build_constant_desc (tree);
2236 static void maybe_output_constant_def_contents (struct constant_descriptor_tree *, int);
2238 /* Compute a hash code for a constant expression. */
2240 static hashval_t
2241 const_desc_hash (const void *ptr)
2243 return ((struct constant_descriptor_tree *)ptr)->hash;
2246 static hashval_t
2247 const_hash_1 (const tree exp)
2249 const char *p;
2250 hashval_t hi;
2251 int len, i;
2252 enum tree_code code = TREE_CODE (exp);
2254 /* Either set P and LEN to the address and len of something to hash and
2255 exit the switch or return a value. */
2257 switch (code)
2259 case INTEGER_CST:
2260 p = (char *) &TREE_INT_CST (exp);
2261 len = sizeof TREE_INT_CST (exp);
2262 break;
2264 case REAL_CST:
2265 return real_hash (TREE_REAL_CST_PTR (exp));
2267 case STRING_CST:
2268 p = TREE_STRING_POINTER (exp);
2269 len = TREE_STRING_LENGTH (exp);
2270 break;
2272 case COMPLEX_CST:
2273 return (const_hash_1 (TREE_REALPART (exp)) * 5
2274 + const_hash_1 (TREE_IMAGPART (exp)));
2276 case CONSTRUCTOR:
2278 unsigned HOST_WIDE_INT idx;
2279 tree value;
2281 hi = 5 + int_size_in_bytes (TREE_TYPE (exp));
2283 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (exp), idx, value)
2284 if (value)
2285 hi = hi * 603 + const_hash_1 (value);
2287 return hi;
2290 case ADDR_EXPR:
2291 case FDESC_EXPR:
2293 struct addr_const value;
2295 decode_addr_const (exp, &value);
2296 switch (GET_CODE (value.base))
2298 case SYMBOL_REF:
2299 /* Don't hash the address of the SYMBOL_REF;
2300 only use the offset and the symbol name. */
2301 hi = value.offset;
2302 p = XSTR (value.base, 0);
2303 for (i = 0; p[i] != 0; i++)
2304 hi = ((hi * 613) + (unsigned) (p[i]));
2305 break;
2307 case LABEL_REF:
2308 hi = value.offset + CODE_LABEL_NUMBER (XEXP (value.base, 0)) * 13;
2309 break;
2311 default:
2312 gcc_unreachable ();
2315 return hi;
2317 case PLUS_EXPR:
2318 case MINUS_EXPR:
2319 return (const_hash_1 (TREE_OPERAND (exp, 0)) * 9
2320 + const_hash_1 (TREE_OPERAND (exp, 1)));
2322 case NOP_EXPR:
2323 case CONVERT_EXPR:
2324 case NON_LVALUE_EXPR:
2325 return const_hash_1 (TREE_OPERAND (exp, 0)) * 7 + 2;
2327 default:
2328 /* A language specific constant. Just hash the code. */
2329 return code;
2332 /* Compute hashing function. */
2333 hi = len;
2334 for (i = 0; i < len; i++)
2335 hi = ((hi * 613) + (unsigned) (p[i]));
2337 return hi;
2340 /* Wrapper of compare_constant, for the htab interface. */
2341 static int
2342 const_desc_eq (const void *p1, const void *p2)
2344 const struct constant_descriptor_tree *c1 = p1;
2345 const struct constant_descriptor_tree *c2 = p2;
2346 if (c1->hash != c2->hash)
2347 return 0;
2348 return compare_constant (c1->value, c2->value);
2351 /* Compare t1 and t2, and return 1 only if they are known to result in
2352 the same bit pattern on output. */
2354 static int
2355 compare_constant (const tree t1, const tree t2)
2357 enum tree_code typecode;
2359 if (t1 == NULL_TREE)
2360 return t2 == NULL_TREE;
2361 if (t2 == NULL_TREE)
2362 return 0;
2364 if (TREE_CODE (t1) != TREE_CODE (t2))
2365 return 0;
2367 switch (TREE_CODE (t1))
2369 case INTEGER_CST:
2370 /* Integer constants are the same only if the same width of type. */
2371 if (TYPE_PRECISION (TREE_TYPE (t1)) != TYPE_PRECISION (TREE_TYPE (t2)))
2372 return 0;
2373 return tree_int_cst_equal (t1, t2);
2375 case REAL_CST:
2376 /* Real constants are the same only if the same width of type. */
2377 if (TYPE_PRECISION (TREE_TYPE (t1)) != TYPE_PRECISION (TREE_TYPE (t2)))
2378 return 0;
2380 return REAL_VALUES_IDENTICAL (TREE_REAL_CST (t1), TREE_REAL_CST (t2));
2382 case STRING_CST:
2383 if (TYPE_MODE (TREE_TYPE (t1)) != TYPE_MODE (TREE_TYPE (t2)))
2384 return 0;
2386 return (TREE_STRING_LENGTH (t1) == TREE_STRING_LENGTH (t2)
2387 && ! memcmp (TREE_STRING_POINTER (t1), TREE_STRING_POINTER (t2),
2388 TREE_STRING_LENGTH (t1)));
2390 case COMPLEX_CST:
2391 return (compare_constant (TREE_REALPART (t1), TREE_REALPART (t2))
2392 && compare_constant (TREE_IMAGPART (t1), TREE_IMAGPART (t2)));
2394 case CONSTRUCTOR:
2396 VEC(constructor_elt, gc) *v1, *v2;
2397 unsigned HOST_WIDE_INT idx;
2399 typecode = TREE_CODE (TREE_TYPE (t1));
2400 if (typecode != TREE_CODE (TREE_TYPE (t2)))
2401 return 0;
2403 if (typecode == ARRAY_TYPE)
2405 HOST_WIDE_INT size_1 = int_size_in_bytes (TREE_TYPE (t1));
2406 /* For arrays, check that the sizes all match. */
2407 if (TYPE_MODE (TREE_TYPE (t1)) != TYPE_MODE (TREE_TYPE (t2))
2408 || size_1 == -1
2409 || size_1 != int_size_in_bytes (TREE_TYPE (t2)))
2410 return 0;
2412 else
2414 /* For record and union constructors, require exact type
2415 equality. */
2416 if (TREE_TYPE (t1) != TREE_TYPE (t2))
2417 return 0;
2420 v1 = CONSTRUCTOR_ELTS (t1);
2421 v2 = CONSTRUCTOR_ELTS (t2);
2422 if (VEC_length (constructor_elt, v1)
2423 != VEC_length (constructor_elt, v2))
2424 return 0;
2426 for (idx = 0; idx < VEC_length (constructor_elt, v1); ++idx)
2428 constructor_elt *c1 = VEC_index (constructor_elt, v1, idx);
2429 constructor_elt *c2 = VEC_index (constructor_elt, v2, idx);
2431 /* Check that each value is the same... */
2432 if (!compare_constant (c1->value, c2->value))
2433 return 0;
2434 /* ... and that they apply to the same fields! */
2435 if (typecode == ARRAY_TYPE)
2437 if (!compare_constant (c1->index, c2->index))
2438 return 0;
2440 else
2442 if (c1->index != c2->index)
2443 return 0;
2447 return 1;
2450 case ADDR_EXPR:
2451 case FDESC_EXPR:
2453 struct addr_const value1, value2;
2455 decode_addr_const (t1, &value1);
2456 decode_addr_const (t2, &value2);
2457 return (value1.offset == value2.offset
2458 && strcmp (XSTR (value1.base, 0), XSTR (value2.base, 0)) == 0);
2461 case PLUS_EXPR:
2462 case MINUS_EXPR:
2463 case RANGE_EXPR:
2464 return (compare_constant (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0))
2465 && compare_constant(TREE_OPERAND (t1, 1), TREE_OPERAND (t2, 1)));
2467 case NOP_EXPR:
2468 case CONVERT_EXPR:
2469 case NON_LVALUE_EXPR:
2470 case VIEW_CONVERT_EXPR:
2471 return compare_constant (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
2473 default:
2475 tree nt1, nt2;
2476 nt1 = lang_hooks.expand_constant (t1);
2477 nt2 = lang_hooks.expand_constant (t2);
2478 if (nt1 != t1 || nt2 != t2)
2479 return compare_constant (nt1, nt2);
2480 else
2481 return 0;
2485 gcc_unreachable ();
2488 /* Make a copy of the whole tree structure for a constant. This
2489 handles the same types of nodes that compare_constant handles. */
2491 static tree
2492 copy_constant (tree exp)
2494 switch (TREE_CODE (exp))
2496 case ADDR_EXPR:
2497 /* For ADDR_EXPR, we do not want to copy the decl whose address
2498 is requested. We do want to copy constants though. */
2499 if (CONSTANT_CLASS_P (TREE_OPERAND (exp, 0)))
2500 return build1 (TREE_CODE (exp), TREE_TYPE (exp),
2501 copy_constant (TREE_OPERAND (exp, 0)));
2502 else
2503 return copy_node (exp);
2505 case INTEGER_CST:
2506 case REAL_CST:
2507 case STRING_CST:
2508 return copy_node (exp);
2510 case COMPLEX_CST:
2511 return build_complex (TREE_TYPE (exp),
2512 copy_constant (TREE_REALPART (exp)),
2513 copy_constant (TREE_IMAGPART (exp)));
2515 case PLUS_EXPR:
2516 case MINUS_EXPR:
2517 return build2 (TREE_CODE (exp), TREE_TYPE (exp),
2518 copy_constant (TREE_OPERAND (exp, 0)),
2519 copy_constant (TREE_OPERAND (exp, 1)));
2521 case NOP_EXPR:
2522 case CONVERT_EXPR:
2523 case NON_LVALUE_EXPR:
2524 case VIEW_CONVERT_EXPR:
2525 return build1 (TREE_CODE (exp), TREE_TYPE (exp),
2526 copy_constant (TREE_OPERAND (exp, 0)));
2528 case CONSTRUCTOR:
2530 tree copy = copy_node (exp);
2531 VEC(constructor_elt, gc) *v;
2532 unsigned HOST_WIDE_INT idx;
2533 tree purpose, value;
2535 v = VEC_alloc(constructor_elt, gc, VEC_length(constructor_elt,
2536 CONSTRUCTOR_ELTS (exp)));
2537 FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (exp), idx, purpose, value)
2539 constructor_elt *ce = VEC_quick_push (constructor_elt, v, NULL);
2540 ce->index = purpose;
2541 ce->value = copy_constant (value);
2543 CONSTRUCTOR_ELTS (copy) = v;
2544 return copy;
2547 default:
2549 tree t = lang_hooks.expand_constant (exp);
2551 gcc_assert (t == exp);
2552 return copy_constant (t);
2557 /* Subroutine of output_constant_def:
2558 No constant equal to EXP is known to have been output.
2559 Make a constant descriptor to enter EXP in the hash table.
2560 Assign the label number and construct RTL to refer to the
2561 constant's location in memory.
2562 Caller is responsible for updating the hash table. */
2564 static struct constant_descriptor_tree *
2565 build_constant_desc (tree exp)
2567 rtx symbol;
2568 rtx rtl;
2569 char label[256];
2570 int labelno;
2571 struct constant_descriptor_tree *desc;
2573 desc = ggc_alloc (sizeof (*desc));
2574 desc->value = copy_constant (exp);
2576 /* Propagate marked-ness to copied constant. */
2577 if (flag_mudflap && mf_marked_p (exp))
2578 mf_mark (desc->value);
2580 /* Create a string containing the label name, in LABEL. */
2581 labelno = const_labelno++;
2582 ASM_GENERATE_INTERNAL_LABEL (label, "LC", labelno);
2584 /* We have a symbol name; construct the SYMBOL_REF and the MEM. */
2585 symbol = gen_rtx_SYMBOL_REF (Pmode, ggc_strdup (label));
2586 SYMBOL_REF_FLAGS (symbol) = SYMBOL_FLAG_LOCAL;
2587 SET_SYMBOL_REF_DECL (symbol, desc->value);
2588 TREE_CONSTANT_POOL_ADDRESS_P (symbol) = 1;
2590 rtl = gen_rtx_MEM (TYPE_MODE (TREE_TYPE (exp)), symbol);
2591 set_mem_attributes (rtl, exp, 1);
2592 set_mem_alias_set (rtl, 0);
2593 set_mem_alias_set (rtl, const_alias_set);
2595 /* Set flags or add text to the name to record information, such as
2596 that it is a local symbol. If the name is changed, the macro
2597 ASM_OUTPUT_LABELREF will have to know how to strip this
2598 information. This call might invalidate our local variable
2599 SYMBOL; we can't use it afterward. */
2601 targetm.encode_section_info (exp, rtl, true);
2603 desc->rtl = rtl;
2605 return desc;
2608 /* Return an rtx representing a reference to constant data in memory
2609 for the constant expression EXP.
2611 If assembler code for such a constant has already been output,
2612 return an rtx to refer to it.
2613 Otherwise, output such a constant in memory
2614 and generate an rtx for it.
2616 If DEFER is nonzero, this constant can be deferred and output only
2617 if referenced in the function after all optimizations.
2619 `const_desc_table' records which constants already have label strings. */
2622 output_constant_def (tree exp, int defer)
2624 struct constant_descriptor_tree *desc;
2625 struct constant_descriptor_tree key;
2626 void **loc;
2628 /* Look up EXP in the table of constant descriptors. If we didn't find
2629 it, create a new one. */
2630 key.value = exp;
2631 key.hash = const_hash_1 (exp);
2632 loc = htab_find_slot_with_hash (const_desc_htab, &key, key.hash, INSERT);
2634 desc = *loc;
2635 if (desc == 0)
2637 desc = build_constant_desc (exp);
2638 desc->hash = key.hash;
2639 *loc = desc;
2642 maybe_output_constant_def_contents (desc, defer);
2643 return desc->rtl;
2646 /* Subroutine of output_constant_def: Decide whether or not we need to
2647 output the constant DESC now, and if so, do it. */
2648 static void
2649 maybe_output_constant_def_contents (struct constant_descriptor_tree *desc,
2650 int defer)
2652 rtx symbol = XEXP (desc->rtl, 0);
2653 tree exp = desc->value;
2655 if (flag_syntax_only)
2656 return;
2658 if (TREE_ASM_WRITTEN (exp))
2659 /* Already output; don't do it again. */
2660 return;
2662 /* We can always defer constants as long as the context allows
2663 doing so. */
2664 if (defer)
2666 /* Increment n_deferred_constants if it exists. It needs to be at
2667 least as large as the number of constants actually referred to
2668 by the function. If it's too small we'll stop looking too early
2669 and fail to emit constants; if it's too large we'll only look
2670 through the entire function when we could have stopped earlier. */
2671 if (cfun)
2672 n_deferred_constants++;
2673 return;
2676 output_constant_def_contents (symbol);
2679 /* We must output the constant data referred to by SYMBOL; do so. */
2681 static void
2682 output_constant_def_contents (rtx symbol)
2684 tree exp = SYMBOL_REF_DECL (symbol);
2685 const char *label = XSTR (symbol, 0);
2686 HOST_WIDE_INT size;
2688 /* Make sure any other constants whose addresses appear in EXP
2689 are assigned label numbers. */
2690 int reloc = compute_reloc_for_constant (exp);
2692 /* Align the location counter as required by EXP's data type. */
2693 unsigned int align = TYPE_ALIGN (TREE_TYPE (exp));
2694 #ifdef CONSTANT_ALIGNMENT
2695 align = CONSTANT_ALIGNMENT (exp, align);
2696 #endif
2698 output_addressed_constants (exp);
2700 /* We are no longer deferring this constant. */
2701 TREE_ASM_WRITTEN (exp) = 1;
2703 if (IN_NAMED_SECTION (exp))
2704 switch_to_section (get_named_section (exp, NULL, reloc));
2705 else
2706 switch_to_section (targetm.asm_out.select_section (exp, reloc, align));
2708 if (align > BITS_PER_UNIT)
2710 ASM_OUTPUT_ALIGN (asm_out_file, floor_log2 (align / BITS_PER_UNIT));
2713 size = int_size_in_bytes (TREE_TYPE (exp));
2714 if (TREE_CODE (exp) == STRING_CST)
2715 size = MAX (TREE_STRING_LENGTH (exp), size);
2717 /* Do any machine/system dependent processing of the constant. */
2718 #ifdef ASM_DECLARE_CONSTANT_NAME
2719 ASM_DECLARE_CONSTANT_NAME (asm_out_file, label, exp, size);
2720 #else
2721 /* Standard thing is just output label for the constant. */
2722 ASM_OUTPUT_LABEL (asm_out_file, label);
2723 #endif /* ASM_DECLARE_CONSTANT_NAME */
2725 /* Output the value of EXP. */
2726 output_constant (exp, size, align);
2727 if (flag_mudflap)
2728 mudflap_enqueue_constant (exp);
2731 /* Look up EXP in the table of constant descriptors. Return the rtl
2732 if it has been emitted, else null. */
2735 lookup_constant_def (tree exp)
2737 struct constant_descriptor_tree *desc;
2738 struct constant_descriptor_tree key;
2740 key.value = exp;
2741 key.hash = const_hash_1 (exp);
2742 desc = htab_find_with_hash (const_desc_htab, &key, key.hash);
2744 return (desc ? desc->rtl : NULL_RTX);
2747 /* Used in the hash tables to avoid outputting the same constant
2748 twice. Unlike 'struct constant_descriptor_tree', RTX constants
2749 are output once per function, not once per file. */
2750 /* ??? Only a few targets need per-function constant pools. Most
2751 can use one per-file pool. Should add a targetm bit to tell the
2752 difference. */
2754 struct rtx_constant_pool GTY(())
2756 /* Pointers to first and last constant in pool, as ordered by offset. */
2757 struct constant_descriptor_rtx *first;
2758 struct constant_descriptor_rtx *last;
2760 /* Hash facility for making memory-constants from constant rtl-expressions.
2761 It is used on RISC machines where immediate integer arguments and
2762 constant addresses are restricted so that such constants must be stored
2763 in memory. */
2764 htab_t GTY((param_is (struct constant_descriptor_rtx))) const_rtx_htab;
2766 /* Current offset in constant pool (does not include any
2767 machine-specific header). */
2768 HOST_WIDE_INT offset;
2771 struct constant_descriptor_rtx GTY((chain_next ("%h.next")))
2773 struct constant_descriptor_rtx *next;
2774 rtx mem;
2775 rtx sym;
2776 rtx constant;
2777 HOST_WIDE_INT offset;
2778 hashval_t hash;
2779 enum machine_mode mode;
2780 unsigned int align;
2781 int labelno;
2782 int mark;
2785 /* Hash and compare functions for const_rtx_htab. */
2787 static hashval_t
2788 const_desc_rtx_hash (const void *ptr)
2790 const struct constant_descriptor_rtx *desc = ptr;
2791 return desc->hash;
2794 static int
2795 const_desc_rtx_eq (const void *a, const void *b)
2797 const struct constant_descriptor_rtx *x = a;
2798 const struct constant_descriptor_rtx *y = b;
2800 if (x->mode != y->mode)
2801 return 0;
2802 return rtx_equal_p (x->constant, y->constant);
2805 /* This is the worker function for const_rtx_hash, called via for_each_rtx. */
2807 static int
2808 const_rtx_hash_1 (rtx *xp, void *data)
2810 unsigned HOST_WIDE_INT hwi;
2811 enum machine_mode mode;
2812 enum rtx_code code;
2813 hashval_t h, *hp;
2814 rtx x;
2816 x = *xp;
2817 code = GET_CODE (x);
2818 mode = GET_MODE (x);
2819 h = (hashval_t) code * 1048573 + mode;
2821 switch (code)
2823 case CONST_INT:
2824 hwi = INTVAL (x);
2825 fold_hwi:
2827 const int shift = sizeof (hashval_t) * CHAR_BIT;
2828 const int n = sizeof (HOST_WIDE_INT) / sizeof (hashval_t);
2829 int i;
2831 h ^= (hashval_t) hwi;
2832 for (i = 1; i < n; ++i)
2834 hwi >>= shift;
2835 h ^= (hashval_t) hwi;
2838 break;
2840 case CONST_DOUBLE:
2841 if (mode == VOIDmode)
2843 hwi = CONST_DOUBLE_LOW (x) ^ CONST_DOUBLE_HIGH (x);
2844 goto fold_hwi;
2846 else
2847 h ^= real_hash (CONST_DOUBLE_REAL_VALUE (x));
2848 break;
2850 case CONST_VECTOR:
2852 int i;
2853 for (i = XVECLEN (x, 0); i-- > 0; )
2854 h = h * 251 + const_rtx_hash_1 (&XVECEXP (x, 0, i), data);
2856 break;
2858 case SYMBOL_REF:
2859 h ^= htab_hash_string (XSTR (x, 0));
2860 break;
2862 case LABEL_REF:
2863 h = h * 251 + CODE_LABEL_NUMBER (XEXP (x, 0));
2864 break;
2866 case UNSPEC:
2867 case UNSPEC_VOLATILE:
2868 h = h * 251 + XINT (x, 1);
2869 break;
2871 default:
2872 break;
2875 hp = data;
2876 *hp = *hp * 509 + h;
2877 return 0;
2880 /* Compute a hash value for X, which should be a constant. */
2882 static hashval_t
2883 const_rtx_hash (rtx x)
2885 hashval_t h = 0;
2886 for_each_rtx (&x, const_rtx_hash_1, &h);
2887 return h;
2891 /* Initialize constant pool hashing for a new function. */
2893 void
2894 init_varasm_status (struct function *f)
2896 struct varasm_status *p;
2897 struct rtx_constant_pool *pool;
2899 p = ggc_alloc (sizeof (struct varasm_status));
2900 f->varasm = p;
2902 pool = ggc_alloc (sizeof (struct rtx_constant_pool));
2903 p->pool = pool;
2904 p->deferred_constants = 0;
2906 pool->const_rtx_htab = htab_create_ggc (31, const_desc_rtx_hash,
2907 const_desc_rtx_eq, NULL);
2908 pool->first = pool->last = NULL;
2909 pool->offset = 0;
2912 /* Given a MINUS expression, simplify it if both sides
2913 include the same symbol. */
2916 simplify_subtraction (rtx x)
2918 rtx r = simplify_rtx (x);
2919 return r ? r : x;
2922 /* Given a constant rtx X, make (or find) a memory constant for its value
2923 and return a MEM rtx to refer to it in memory. */
2926 force_const_mem (enum machine_mode mode, rtx x)
2928 struct constant_descriptor_rtx *desc, tmp;
2929 struct rtx_constant_pool *pool = cfun->varasm->pool;
2930 char label[256];
2931 rtx def, symbol;
2932 hashval_t hash;
2933 unsigned int align;
2934 void **slot;
2936 /* If we're not allowed to drop X into the constant pool, don't. */
2937 if (targetm.cannot_force_const_mem (x))
2938 return NULL_RTX;
2940 /* Lookup the value in the hashtable. */
2941 tmp.constant = x;
2942 tmp.mode = mode;
2943 hash = const_rtx_hash (x);
2944 slot = htab_find_slot_with_hash (pool->const_rtx_htab, &tmp, hash, INSERT);
2945 desc = *slot;
2947 /* If the constant was already present, return its memory. */
2948 if (desc)
2949 return copy_rtx (desc->mem);
2951 /* Otherwise, create a new descriptor. */
2952 desc = ggc_alloc (sizeof (*desc));
2953 *slot = desc;
2955 /* Align the location counter as required by EXP's data type. */
2956 align = GET_MODE_ALIGNMENT (mode == VOIDmode ? word_mode : mode);
2957 #ifdef CONSTANT_ALIGNMENT
2959 tree type = lang_hooks.types.type_for_mode (mode, 0);
2960 if (type != NULL_TREE)
2961 align = CONSTANT_ALIGNMENT (make_tree (type, x), align);
2963 #endif
2965 pool->offset += (align / BITS_PER_UNIT) - 1;
2966 pool->offset &= ~ ((align / BITS_PER_UNIT) - 1);
2968 desc->next = NULL;
2969 desc->constant = tmp.constant;
2970 desc->offset = pool->offset;
2971 desc->hash = hash;
2972 desc->mode = mode;
2973 desc->align = align;
2974 desc->labelno = const_labelno;
2975 desc->mark = 0;
2977 pool->offset += GET_MODE_SIZE (mode);
2978 if (pool->last)
2979 pool->last->next = desc;
2980 else
2981 pool->first = pool->last = desc;
2982 pool->last = desc;
2984 /* Create a string containing the label name, in LABEL. */
2985 ASM_GENERATE_INTERNAL_LABEL (label, "LC", const_labelno);
2986 ++const_labelno;
2988 /* Construct the SYMBOL_REF. Make sure to mark it as belonging to
2989 the constants pool. */
2990 desc->sym = symbol = gen_rtx_SYMBOL_REF (Pmode, ggc_strdup (label));
2991 SYMBOL_REF_FLAGS (symbol) = SYMBOL_FLAG_LOCAL;
2992 CONSTANT_POOL_ADDRESS_P (symbol) = 1;
2993 SET_SYMBOL_REF_CONSTANT (symbol, desc);
2994 current_function_uses_const_pool = 1;
2996 /* Construct the MEM. */
2997 desc->mem = def = gen_const_mem (mode, symbol);
2998 set_mem_attributes (def, lang_hooks.types.type_for_mode (mode, 0), 1);
2999 set_mem_align (def, align);
3001 /* If we're dropping a label to the constant pool, make sure we
3002 don't delete it. */
3003 if (GET_CODE (x) == LABEL_REF)
3004 LABEL_PRESERVE_P (XEXP (x, 0)) = 1;
3006 return copy_rtx (def);
3009 /* Given a constant pool SYMBOL_REF, return the corresponding constant. */
3012 get_pool_constant (rtx addr)
3014 return SYMBOL_REF_CONSTANT (addr)->constant;
3017 /* Given a constant pool SYMBOL_REF, return the corresponding constant
3018 and whether it has been output or not. */
3021 get_pool_constant_mark (rtx addr, bool *pmarked)
3023 struct constant_descriptor_rtx *desc;
3025 desc = SYMBOL_REF_CONSTANT (addr);
3026 *pmarked = (desc->mark != 0);
3027 return desc->constant;
3030 /* Similar, return the mode. */
3032 enum machine_mode
3033 get_pool_mode (rtx addr)
3035 return SYMBOL_REF_CONSTANT (addr)->mode;
3038 /* Return the size of the constant pool. */
3041 get_pool_size (void)
3043 return cfun->varasm->pool->offset;
3046 /* Worker function for output_constant_pool_1. Emit assembly for X
3047 in MODE with known alignment ALIGN. */
3049 static void
3050 output_constant_pool_2 (enum machine_mode mode, rtx x, unsigned int align)
3052 switch (GET_MODE_CLASS (mode))
3054 case MODE_FLOAT:
3055 case MODE_DECIMAL_FLOAT:
3057 REAL_VALUE_TYPE r;
3059 gcc_assert (GET_CODE (x) == CONST_DOUBLE);
3060 REAL_VALUE_FROM_CONST_DOUBLE (r, x);
3061 assemble_real (r, mode, align);
3062 break;
3065 case MODE_INT:
3066 case MODE_PARTIAL_INT:
3067 assemble_integer (x, GET_MODE_SIZE (mode), align, 1);
3068 break;
3070 case MODE_VECTOR_FLOAT:
3071 case MODE_VECTOR_INT:
3073 int i, units;
3074 enum machine_mode submode = GET_MODE_INNER (mode);
3075 unsigned int subalign = MIN (align, GET_MODE_BITSIZE (submode));
3077 gcc_assert (GET_CODE (x) == CONST_VECTOR);
3078 units = CONST_VECTOR_NUNITS (x);
3080 for (i = 0; i < units; i++)
3082 rtx elt = CONST_VECTOR_ELT (x, i);
3083 output_constant_pool_2 (submode, elt, i ? subalign : align);
3086 break;
3088 default:
3089 gcc_unreachable ();
3093 /* Worker function for output_constant_pool. Emit POOL. */
3095 static void
3096 output_constant_pool_1 (struct constant_descriptor_rtx *desc)
3098 rtx x, tmp;
3100 if (!desc->mark)
3101 return;
3102 x = desc->constant;
3104 /* See if X is a LABEL_REF (or a CONST referring to a LABEL_REF)
3105 whose CODE_LABEL has been deleted. This can occur if a jump table
3106 is eliminated by optimization. If so, write a constant of zero
3107 instead. Note that this can also happen by turning the
3108 CODE_LABEL into a NOTE. */
3109 /* ??? This seems completely and utterly wrong. Certainly it's
3110 not true for NOTE_INSN_DELETED_LABEL, but I disbelieve proper
3111 functioning even with INSN_DELETED_P and friends. */
3113 tmp = x;
3114 switch (GET_CODE (x))
3116 case CONST:
3117 if (GET_CODE (XEXP (x, 0)) != PLUS
3118 || GET_CODE (XEXP (XEXP (x, 0), 0)) != LABEL_REF)
3119 break;
3120 tmp = XEXP (XEXP (x, 0), 0);
3121 /* FALLTHRU */
3123 case LABEL_REF:
3124 tmp = XEXP (x, 0);
3125 gcc_assert (!INSN_DELETED_P (tmp));
3126 gcc_assert (!NOTE_P (tmp)
3127 || NOTE_LINE_NUMBER (tmp) != NOTE_INSN_DELETED);
3128 break;
3130 default:
3131 break;
3134 /* First switch to correct section. */
3135 switch_to_section (targetm.asm_out.select_rtx_section (desc->mode, x,
3136 desc->align));
3138 #ifdef ASM_OUTPUT_SPECIAL_POOL_ENTRY
3139 ASM_OUTPUT_SPECIAL_POOL_ENTRY (asm_out_file, x, desc->mode,
3140 desc->align, desc->labelno, done);
3141 #endif
3143 assemble_align (desc->align);
3145 /* Output the label. */
3146 targetm.asm_out.internal_label (asm_out_file, "LC", desc->labelno);
3148 /* Output the data. */
3149 output_constant_pool_2 (desc->mode, x, desc->align);
3151 /* Make sure all constants in SECTION_MERGE and not SECTION_STRINGS
3152 sections have proper size. */
3153 if (desc->align > GET_MODE_BITSIZE (desc->mode)
3154 && in_section
3155 && (in_section->common.flags & SECTION_MERGE))
3156 assemble_align (desc->align);
3158 #ifdef ASM_OUTPUT_SPECIAL_POOL_ENTRY
3159 done:
3160 #endif
3161 return;
3164 /* Given a SYMBOL_REF CURRENT_RTX, mark it and all constants it refers
3165 to as used. Emit referenced deferred strings. This function can
3166 be used with for_each_rtx to mark all SYMBOL_REFs in an rtx. */
3168 static int
3169 mark_constant (rtx *current_rtx, void *data)
3171 struct rtx_constant_pool *pool = data;
3172 rtx x = *current_rtx;
3174 if (x == NULL_RTX || GET_CODE (x) != SYMBOL_REF)
3175 return 0;
3177 if (CONSTANT_POOL_ADDRESS_P (x))
3179 struct constant_descriptor_rtx *desc = SYMBOL_REF_CONSTANT (x);
3180 if (desc->mark == 0)
3182 desc->mark = 1;
3183 for_each_rtx (&desc->constant, mark_constant, pool);
3186 else if (TREE_CONSTANT_POOL_ADDRESS_P (x))
3188 tree exp = SYMBOL_REF_DECL (x);
3189 if (!TREE_ASM_WRITTEN (exp))
3191 n_deferred_constants--;
3192 output_constant_def_contents (x);
3196 return -1;
3199 /* Look through appropriate parts of INSN, marking all entries in the
3200 constant pool which are actually being used. Entries that are only
3201 referenced by other constants are also marked as used. Emit
3202 deferred strings that are used. */
3204 static void
3205 mark_constants (struct rtx_constant_pool *pool, rtx insn)
3207 if (!INSN_P (insn))
3208 return;
3210 /* Insns may appear inside a SEQUENCE. Only check the patterns of
3211 insns, not any notes that may be attached. We don't want to mark
3212 a constant just because it happens to appear in a REG_EQUIV note. */
3213 if (GET_CODE (PATTERN (insn)) == SEQUENCE)
3215 rtx seq = PATTERN (insn);
3216 int i, n = XVECLEN (seq, 0);
3217 for (i = 0; i < n; ++i)
3219 rtx subinsn = XVECEXP (seq, 0, i);
3220 if (INSN_P (subinsn))
3221 for_each_rtx (&PATTERN (subinsn), mark_constant, pool);
3224 else
3225 for_each_rtx (&PATTERN (insn), mark_constant, pool);
3228 /* Look through the instructions for this function, and mark all the
3229 entries in POOL which are actually being used. Emit deferred constants
3230 which have indeed been used. */
3232 static void
3233 mark_constant_pool (struct rtx_constant_pool *pool)
3235 rtx insn, link;
3237 if (pool->first == 0 && n_deferred_constants == 0)
3238 return;
3240 for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
3241 mark_constants (pool, insn);
3243 for (link = current_function_epilogue_delay_list;
3244 link;
3245 link = XEXP (link, 1))
3246 mark_constants (pool, XEXP (link, 0));
3249 /* Write all the constants in the constant pool. */
3251 void
3252 output_constant_pool (const char *fnname ATTRIBUTE_UNUSED,
3253 tree fndecl ATTRIBUTE_UNUSED)
3255 struct rtx_constant_pool *pool = cfun->varasm->pool;
3256 struct constant_descriptor_rtx *desc;
3258 /* It is possible for gcc to call force_const_mem and then to later
3259 discard the instructions which refer to the constant. In such a
3260 case we do not need to output the constant. */
3261 mark_constant_pool (pool);
3263 #ifdef ASM_OUTPUT_POOL_PROLOGUE
3264 ASM_OUTPUT_POOL_PROLOGUE (asm_out_file, fnname, fndecl, pool->offset);
3265 #endif
3267 for (desc = pool->first; desc ; desc = desc->next)
3268 output_constant_pool_1 (desc);
3270 #ifdef ASM_OUTPUT_POOL_EPILOGUE
3271 ASM_OUTPUT_POOL_EPILOGUE (asm_out_file, fnname, fndecl, pool->offset);
3272 #endif
3275 /* Determine what kind of relocations EXP may need. */
3278 compute_reloc_for_constant (tree exp)
3280 int reloc = 0, reloc2;
3281 tree tem;
3283 /* Give the front-end a chance to convert VALUE to something that
3284 looks more like a constant to the back-end. */
3285 exp = lang_hooks.expand_constant (exp);
3287 switch (TREE_CODE (exp))
3289 case ADDR_EXPR:
3290 case FDESC_EXPR:
3291 /* Go inside any operations that get_inner_reference can handle and see
3292 if what's inside is a constant: no need to do anything here for
3293 addresses of variables or functions. */
3294 for (tem = TREE_OPERAND (exp, 0); handled_component_p (tem);
3295 tem = TREE_OPERAND (tem, 0))
3298 if (TREE_PUBLIC (tem))
3299 reloc |= 2;
3300 else
3301 reloc |= 1;
3302 break;
3304 case PLUS_EXPR:
3305 reloc = compute_reloc_for_constant (TREE_OPERAND (exp, 0));
3306 reloc |= compute_reloc_for_constant (TREE_OPERAND (exp, 1));
3307 break;
3309 case MINUS_EXPR:
3310 reloc = compute_reloc_for_constant (TREE_OPERAND (exp, 0));
3311 reloc2 = compute_reloc_for_constant (TREE_OPERAND (exp, 1));
3312 /* The difference of two local labels is computable at link time. */
3313 if (reloc == 1 && reloc2 == 1)
3314 reloc = 0;
3315 else
3316 reloc |= reloc2;
3317 break;
3319 case NOP_EXPR:
3320 case CONVERT_EXPR:
3321 case NON_LVALUE_EXPR:
3322 case VIEW_CONVERT_EXPR:
3323 reloc = compute_reloc_for_constant (TREE_OPERAND (exp, 0));
3324 break;
3326 case CONSTRUCTOR:
3328 unsigned HOST_WIDE_INT idx;
3329 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (exp), idx, tem)
3330 if (tem != 0)
3331 reloc |= compute_reloc_for_constant (tem);
3333 break;
3335 default:
3336 break;
3338 return reloc;
3341 /* Find all the constants whose addresses are referenced inside of EXP,
3342 and make sure assembler code with a label has been output for each one.
3343 Indicate whether an ADDR_EXPR has been encountered. */
3345 static void
3346 output_addressed_constants (tree exp)
3348 tree tem;
3350 /* Give the front-end a chance to convert VALUE to something that
3351 looks more like a constant to the back-end. */
3352 exp = lang_hooks.expand_constant (exp);
3354 switch (TREE_CODE (exp))
3356 case ADDR_EXPR:
3357 case FDESC_EXPR:
3358 /* Go inside any operations that get_inner_reference can handle and see
3359 if what's inside is a constant: no need to do anything here for
3360 addresses of variables or functions. */
3361 for (tem = TREE_OPERAND (exp, 0); handled_component_p (tem);
3362 tem = TREE_OPERAND (tem, 0))
3365 /* If we have an initialized CONST_DECL, retrieve the initializer. */
3366 if (TREE_CODE (tem) == CONST_DECL && DECL_INITIAL (tem))
3367 tem = DECL_INITIAL (tem);
3369 if (CONSTANT_CLASS_P (tem) || TREE_CODE (tem) == CONSTRUCTOR)
3370 output_constant_def (tem, 0);
3371 break;
3373 case PLUS_EXPR:
3374 case MINUS_EXPR:
3375 output_addressed_constants (TREE_OPERAND (exp, 1));
3376 /* Fall through. */
3378 case NOP_EXPR:
3379 case CONVERT_EXPR:
3380 case NON_LVALUE_EXPR:
3381 case VIEW_CONVERT_EXPR:
3382 output_addressed_constants (TREE_OPERAND (exp, 0));
3383 break;
3385 case CONSTRUCTOR:
3387 unsigned HOST_WIDE_INT idx;
3388 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (exp), idx, tem)
3389 if (tem != 0)
3390 output_addressed_constants (tem);
3392 break;
3394 default:
3395 break;
3399 /* Return nonzero if VALUE is a valid constant-valued expression
3400 for use in initializing a static variable; one that can be an
3401 element of a "constant" initializer.
3403 Return null_pointer_node if the value is absolute;
3404 if it is relocatable, return the variable that determines the relocation.
3405 We assume that VALUE has been folded as much as possible;
3406 therefore, we do not need to check for such things as
3407 arithmetic-combinations of integers. */
3409 tree
3410 initializer_constant_valid_p (tree value, tree endtype)
3412 /* Give the front-end a chance to convert VALUE to something that
3413 looks more like a constant to the back-end. */
3414 value = lang_hooks.expand_constant (value);
3416 switch (TREE_CODE (value))
3418 case CONSTRUCTOR:
3419 if ((TREE_CODE (TREE_TYPE (value)) == UNION_TYPE
3420 || TREE_CODE (TREE_TYPE (value)) == RECORD_TYPE)
3421 && TREE_CONSTANT (value)
3422 && !VEC_empty (constructor_elt, CONSTRUCTOR_ELTS (value)))
3424 unsigned HOST_WIDE_INT idx;
3425 tree elt;
3426 bool absolute = true;
3428 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (value), idx, elt)
3430 tree reloc;
3431 reloc = initializer_constant_valid_p (elt, TREE_TYPE (elt));
3432 if (!reloc)
3433 return NULL_TREE;
3434 if (reloc != null_pointer_node)
3435 absolute = false;
3437 /* For a non-absolute relocation, there is no single
3438 variable that can be "the variable that determines the
3439 relocation." */
3440 return absolute ? null_pointer_node : error_mark_node;
3443 return TREE_STATIC (value) ? null_pointer_node : NULL_TREE;
3445 case INTEGER_CST:
3446 case VECTOR_CST:
3447 case REAL_CST:
3448 case STRING_CST:
3449 case COMPLEX_CST:
3450 return null_pointer_node;
3452 case ADDR_EXPR:
3453 case FDESC_EXPR:
3454 value = staticp (TREE_OPERAND (value, 0));
3455 if (value)
3457 /* "&(*a).f" is like unto pointer arithmetic. If "a" turns out to
3458 be a constant, this is old-skool offsetof-like nonsense. */
3459 if (TREE_CODE (value) == INDIRECT_REF
3460 && TREE_CONSTANT (TREE_OPERAND (value, 0)))
3461 return null_pointer_node;
3462 /* Taking the address of a nested function involves a trampoline. */
3463 if (TREE_CODE (value) == FUNCTION_DECL
3464 && ((decl_function_context (value)
3465 && !DECL_NO_STATIC_CHAIN (value))
3466 || DECL_DLLIMPORT_P (value)))
3467 return NULL_TREE;
3468 /* "&{...}" requires a temporary to hold the constructed
3469 object. */
3470 if (TREE_CODE (value) == CONSTRUCTOR)
3471 return NULL_TREE;
3473 return value;
3475 case VIEW_CONVERT_EXPR:
3476 case NON_LVALUE_EXPR:
3477 return initializer_constant_valid_p (TREE_OPERAND (value, 0), endtype);
3479 case CONVERT_EXPR:
3480 case NOP_EXPR:
3482 tree src;
3483 tree src_type;
3484 tree dest_type;
3486 src = TREE_OPERAND (value, 0);
3487 src_type = TREE_TYPE (src);
3488 dest_type = TREE_TYPE (value);
3490 /* Allow conversions between pointer types, floating-point
3491 types, and offset types. */
3492 if ((POINTER_TYPE_P (dest_type) && POINTER_TYPE_P (src_type))
3493 || (FLOAT_TYPE_P (dest_type) && FLOAT_TYPE_P (src_type))
3494 || (TREE_CODE (dest_type) == OFFSET_TYPE
3495 && TREE_CODE (src_type) == OFFSET_TYPE))
3496 return initializer_constant_valid_p (src, endtype);
3498 /* Allow length-preserving conversions between integer types. */
3499 if (INTEGRAL_TYPE_P (dest_type) && INTEGRAL_TYPE_P (src_type)
3500 && (TYPE_PRECISION (dest_type) == TYPE_PRECISION (src_type)))
3501 return initializer_constant_valid_p (src, endtype);
3503 /* Allow conversions between other integer types only if
3504 explicit value. */
3505 if (INTEGRAL_TYPE_P (dest_type) && INTEGRAL_TYPE_P (src_type))
3507 tree inner = initializer_constant_valid_p (src, endtype);
3508 if (inner == null_pointer_node)
3509 return null_pointer_node;
3510 break;
3513 /* Allow (int) &foo provided int is as wide as a pointer. */
3514 if (INTEGRAL_TYPE_P (dest_type) && POINTER_TYPE_P (src_type)
3515 && (TYPE_PRECISION (dest_type) >= TYPE_PRECISION (src_type)))
3516 return initializer_constant_valid_p (src, endtype);
3518 /* Likewise conversions from int to pointers, but also allow
3519 conversions from 0. */
3520 if ((POINTER_TYPE_P (dest_type)
3521 || TREE_CODE (dest_type) == OFFSET_TYPE)
3522 && INTEGRAL_TYPE_P (src_type))
3524 if (TREE_CODE (src) == INTEGER_CST
3525 && TYPE_PRECISION (dest_type) >= TYPE_PRECISION (src_type))
3526 return null_pointer_node;
3527 if (integer_zerop (src))
3528 return null_pointer_node;
3529 else if (TYPE_PRECISION (dest_type) <= TYPE_PRECISION (src_type))
3530 return initializer_constant_valid_p (src, endtype);
3533 /* Allow conversions to struct or union types if the value
3534 inside is okay. */
3535 if (TREE_CODE (dest_type) == RECORD_TYPE
3536 || TREE_CODE (dest_type) == UNION_TYPE)
3537 return initializer_constant_valid_p (src, endtype);
3539 break;
3541 case PLUS_EXPR:
3542 if (! INTEGRAL_TYPE_P (endtype)
3543 || TYPE_PRECISION (endtype) >= POINTER_SIZE)
3545 tree valid0 = initializer_constant_valid_p (TREE_OPERAND (value, 0),
3546 endtype);
3547 tree valid1 = initializer_constant_valid_p (TREE_OPERAND (value, 1),
3548 endtype);
3549 /* If either term is absolute, use the other terms relocation. */
3550 if (valid0 == null_pointer_node)
3551 return valid1;
3552 if (valid1 == null_pointer_node)
3553 return valid0;
3555 break;
3557 case MINUS_EXPR:
3558 if (! INTEGRAL_TYPE_P (endtype)
3559 || TYPE_PRECISION (endtype) >= POINTER_SIZE)
3561 tree valid0 = initializer_constant_valid_p (TREE_OPERAND (value, 0),
3562 endtype);
3563 tree valid1 = initializer_constant_valid_p (TREE_OPERAND (value, 1),
3564 endtype);
3565 /* Win if second argument is absolute. */
3566 if (valid1 == null_pointer_node)
3567 return valid0;
3568 /* Win if both arguments have the same relocation.
3569 Then the value is absolute. */
3570 if (valid0 == valid1 && valid0 != 0)
3571 return null_pointer_node;
3573 /* Since GCC guarantees that string constants are unique in the
3574 generated code, a subtraction between two copies of the same
3575 constant string is absolute. */
3576 if (valid0 && TREE_CODE (valid0) == STRING_CST
3577 && valid1 && TREE_CODE (valid1) == STRING_CST
3578 && operand_equal_p (valid0, valid1, 1))
3579 return null_pointer_node;
3582 /* Support narrowing differences. */
3583 if (INTEGRAL_TYPE_P (endtype))
3585 tree op0, op1;
3587 op0 = TREE_OPERAND (value, 0);
3588 op1 = TREE_OPERAND (value, 1);
3590 /* Like STRIP_NOPS except allow the operand mode to widen.
3591 This works around a feature of fold that simplifies
3592 (int)(p1 - p2) to ((int)p1 - (int)p2) under the theory
3593 that the narrower operation is cheaper. */
3595 while (TREE_CODE (op0) == NOP_EXPR
3596 || TREE_CODE (op0) == CONVERT_EXPR
3597 || TREE_CODE (op0) == NON_LVALUE_EXPR)
3599 tree inner = TREE_OPERAND (op0, 0);
3600 if (inner == error_mark_node
3601 || ! INTEGRAL_MODE_P (TYPE_MODE (TREE_TYPE (inner)))
3602 || (GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op0)))
3603 > GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (inner)))))
3604 break;
3605 op0 = inner;
3608 while (TREE_CODE (op1) == NOP_EXPR
3609 || TREE_CODE (op1) == CONVERT_EXPR
3610 || TREE_CODE (op1) == NON_LVALUE_EXPR)
3612 tree inner = TREE_OPERAND (op1, 0);
3613 if (inner == error_mark_node
3614 || ! INTEGRAL_MODE_P (TYPE_MODE (TREE_TYPE (inner)))
3615 || (GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op1)))
3616 > GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (inner)))))
3617 break;
3618 op1 = inner;
3621 op0 = initializer_constant_valid_p (op0, endtype);
3622 op1 = initializer_constant_valid_p (op1, endtype);
3624 /* Both initializers must be known. */
3625 if (op0 && op1)
3627 if (op0 == op1)
3628 return null_pointer_node;
3630 /* Support differences between labels. */
3631 if (TREE_CODE (op0) == LABEL_DECL
3632 && TREE_CODE (op1) == LABEL_DECL)
3633 return null_pointer_node;
3635 if (TREE_CODE (op0) == STRING_CST
3636 && TREE_CODE (op1) == STRING_CST
3637 && operand_equal_p (op0, op1, 1))
3638 return null_pointer_node;
3641 break;
3643 default:
3644 break;
3647 return 0;
3650 /* Output assembler code for constant EXP to FILE, with no label.
3651 This includes the pseudo-op such as ".int" or ".byte", and a newline.
3652 Assumes output_addressed_constants has been done on EXP already.
3654 Generate exactly SIZE bytes of assembler data, padding at the end
3655 with zeros if necessary. SIZE must always be specified.
3657 SIZE is important for structure constructors,
3658 since trailing members may have been omitted from the constructor.
3659 It is also important for initialization of arrays from string constants
3660 since the full length of the string constant might not be wanted.
3661 It is also needed for initialization of unions, where the initializer's
3662 type is just one member, and that may not be as long as the union.
3664 There a case in which we would fail to output exactly SIZE bytes:
3665 for a structure constructor that wants to produce more than SIZE bytes.
3666 But such constructors will never be generated for any possible input.
3668 ALIGN is the alignment of the data in bits. */
3670 void
3671 output_constant (tree exp, unsigned HOST_WIDE_INT size, unsigned int align)
3673 enum tree_code code;
3674 unsigned HOST_WIDE_INT thissize;
3676 /* Some front-ends use constants other than the standard language-independent
3677 varieties, but which may still be output directly. Give the front-end a
3678 chance to convert EXP to a language-independent representation. */
3679 exp = lang_hooks.expand_constant (exp);
3681 if (size == 0 || flag_syntax_only)
3682 return;
3684 /* See if we're trying to initialize a pointer in a non-default mode
3685 to the address of some declaration somewhere. If the target says
3686 the mode is valid for pointers, assume the target has a way of
3687 resolving it. */
3688 if (TREE_CODE (exp) == NOP_EXPR
3689 && POINTER_TYPE_P (TREE_TYPE (exp))
3690 && targetm.valid_pointer_mode (TYPE_MODE (TREE_TYPE (exp))))
3692 tree saved_type = TREE_TYPE (exp);
3694 /* Peel off any intermediate conversions-to-pointer for valid
3695 pointer modes. */
3696 while (TREE_CODE (exp) == NOP_EXPR
3697 && POINTER_TYPE_P (TREE_TYPE (exp))
3698 && targetm.valid_pointer_mode (TYPE_MODE (TREE_TYPE (exp))))
3699 exp = TREE_OPERAND (exp, 0);
3701 /* If what we're left with is the address of something, we can
3702 convert the address to the final type and output it that
3703 way. */
3704 if (TREE_CODE (exp) == ADDR_EXPR)
3705 exp = build1 (ADDR_EXPR, saved_type, TREE_OPERAND (exp, 0));
3706 /* Likewise for constant ints. */
3707 else if (TREE_CODE (exp) == INTEGER_CST)
3708 exp = build_int_cst_wide (saved_type, TREE_INT_CST_LOW (exp),
3709 TREE_INT_CST_HIGH (exp));
3713 /* Eliminate any conversions since we'll be outputting the underlying
3714 constant. */
3715 while (TREE_CODE (exp) == NOP_EXPR || TREE_CODE (exp) == CONVERT_EXPR
3716 || TREE_CODE (exp) == NON_LVALUE_EXPR
3717 || TREE_CODE (exp) == VIEW_CONVERT_EXPR)
3719 HOST_WIDE_INT type_size = int_size_in_bytes (TREE_TYPE (exp));
3720 HOST_WIDE_INT op_size = int_size_in_bytes (TREE_TYPE (TREE_OPERAND (exp, 0)));
3722 /* Make sure eliminating the conversion is really a no-op, except with
3723 VIEW_CONVERT_EXPRs to allow for wild Ada unchecked conversions and
3724 union types to allow for Ada unchecked unions. */
3725 if (type_size > op_size
3726 && TREE_CODE (exp) != VIEW_CONVERT_EXPR
3727 && TREE_CODE (TREE_TYPE (exp)) != UNION_TYPE)
3728 internal_error ("no-op convert from %wd to %wd bytes in initializer",
3729 op_size, type_size);
3731 exp = TREE_OPERAND (exp, 0);
3734 code = TREE_CODE (TREE_TYPE (exp));
3735 thissize = int_size_in_bytes (TREE_TYPE (exp));
3737 /* Allow a constructor with no elements for any data type.
3738 This means to fill the space with zeros. */
3739 if (TREE_CODE (exp) == CONSTRUCTOR
3740 && VEC_empty (constructor_elt, CONSTRUCTOR_ELTS (exp)))
3742 assemble_zeros (size);
3743 return;
3746 if (TREE_CODE (exp) == FDESC_EXPR)
3748 #ifdef ASM_OUTPUT_FDESC
3749 HOST_WIDE_INT part = tree_low_cst (TREE_OPERAND (exp, 1), 0);
3750 tree decl = TREE_OPERAND (exp, 0);
3751 ASM_OUTPUT_FDESC (asm_out_file, decl, part);
3752 #else
3753 gcc_unreachable ();
3754 #endif
3755 return;
3758 /* Now output the underlying data. If we've handling the padding, return.
3759 Otherwise, break and ensure SIZE is the size written. */
3760 switch (code)
3762 case BOOLEAN_TYPE:
3763 case INTEGER_TYPE:
3764 case ENUMERAL_TYPE:
3765 case POINTER_TYPE:
3766 case REFERENCE_TYPE:
3767 case OFFSET_TYPE:
3768 if (! assemble_integer (expand_expr (exp, NULL_RTX, VOIDmode,
3769 EXPAND_INITIALIZER),
3770 MIN (size, thissize), align, 0))
3771 error ("initializer for integer value is too complicated");
3772 break;
3774 case REAL_TYPE:
3775 if (TREE_CODE (exp) != REAL_CST)
3776 error ("initializer for floating value is not a floating constant");
3778 assemble_real (TREE_REAL_CST (exp), TYPE_MODE (TREE_TYPE (exp)), align);
3779 break;
3781 case COMPLEX_TYPE:
3782 output_constant (TREE_REALPART (exp), thissize / 2, align);
3783 output_constant (TREE_IMAGPART (exp), thissize / 2,
3784 min_align (align, BITS_PER_UNIT * (thissize / 2)));
3785 break;
3787 case ARRAY_TYPE:
3788 case VECTOR_TYPE:
3789 switch (TREE_CODE (exp))
3791 case CONSTRUCTOR:
3792 output_constructor (exp, size, align);
3793 return;
3794 case STRING_CST:
3795 thissize = MIN ((unsigned HOST_WIDE_INT)TREE_STRING_LENGTH (exp),
3796 size);
3797 assemble_string (TREE_STRING_POINTER (exp), thissize);
3798 break;
3800 case VECTOR_CST:
3802 int elt_size;
3803 tree link;
3804 unsigned int nalign;
3805 enum machine_mode inner;
3807 inner = TYPE_MODE (TREE_TYPE (TREE_TYPE (exp)));
3808 nalign = MIN (align, GET_MODE_ALIGNMENT (inner));
3810 elt_size = GET_MODE_SIZE (inner);
3812 link = TREE_VECTOR_CST_ELTS (exp);
3813 output_constant (TREE_VALUE (link), elt_size, align);
3814 while ((link = TREE_CHAIN (link)) != NULL)
3815 output_constant (TREE_VALUE (link), elt_size, nalign);
3816 break;
3818 default:
3819 gcc_unreachable ();
3821 break;
3823 case RECORD_TYPE:
3824 case UNION_TYPE:
3825 gcc_assert (TREE_CODE (exp) == CONSTRUCTOR);
3826 output_constructor (exp, size, align);
3827 return;
3829 case ERROR_MARK:
3830 return;
3832 default:
3833 gcc_unreachable ();
3836 if (size > thissize)
3837 assemble_zeros (size - thissize);
3841 /* Subroutine of output_constructor, used for computing the size of
3842 arrays of unspecified length. VAL must be a CONSTRUCTOR of an array
3843 type with an unspecified upper bound. */
3845 static unsigned HOST_WIDE_INT
3846 array_size_for_constructor (tree val)
3848 tree max_index, i;
3849 unsigned HOST_WIDE_INT cnt;
3850 tree index, value;
3852 /* This code used to attempt to handle string constants that are not
3853 arrays of single-bytes, but nothing else does, so there's no point in
3854 doing it here. */
3855 if (TREE_CODE (val) == STRING_CST)
3856 return TREE_STRING_LENGTH (val);
3858 max_index = NULL_TREE;
3859 FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (val), cnt, index, value)
3861 if (TREE_CODE (index) == RANGE_EXPR)
3862 index = TREE_OPERAND (index, 1);
3863 if (max_index == NULL_TREE || tree_int_cst_lt (max_index, index))
3864 max_index = index;
3867 if (max_index == NULL_TREE)
3868 return 0;
3870 /* Compute the total number of array elements. */
3871 i = size_binop (MINUS_EXPR, convert (sizetype, max_index),
3872 convert (sizetype,
3873 TYPE_MIN_VALUE (TYPE_DOMAIN (TREE_TYPE (val)))));
3874 i = size_binop (PLUS_EXPR, i, build_int_cst (sizetype, 1));
3876 /* Multiply by the array element unit size to find number of bytes. */
3877 i = size_binop (MULT_EXPR, i, TYPE_SIZE_UNIT (TREE_TYPE (TREE_TYPE (val))));
3879 return tree_low_cst (i, 1);
3882 /* Subroutine of output_constant, used for CONSTRUCTORs (aggregate constants).
3883 Generate at least SIZE bytes, padding if necessary. */
3885 static void
3886 output_constructor (tree exp, unsigned HOST_WIDE_INT size,
3887 unsigned int align)
3889 tree type = TREE_TYPE (exp);
3890 tree field = 0;
3891 tree min_index = 0;
3892 /* Number of bytes output or skipped so far.
3893 In other words, current position within the constructor. */
3894 HOST_WIDE_INT total_bytes = 0;
3895 /* Nonzero means BYTE contains part of a byte, to be output. */
3896 int byte_buffer_in_use = 0;
3897 int byte = 0;
3898 unsigned HOST_WIDE_INT cnt;
3899 constructor_elt *ce;
3901 gcc_assert (HOST_BITS_PER_WIDE_INT >= BITS_PER_UNIT);
3903 if (TREE_CODE (type) == RECORD_TYPE)
3904 field = TYPE_FIELDS (type);
3906 if (TREE_CODE (type) == ARRAY_TYPE
3907 && TYPE_DOMAIN (type) != 0)
3908 min_index = TYPE_MIN_VALUE (TYPE_DOMAIN (type));
3910 /* As LINK goes through the elements of the constant,
3911 FIELD goes through the structure fields, if the constant is a structure.
3912 if the constant is a union, then we override this,
3913 by getting the field from the TREE_LIST element.
3914 But the constant could also be an array. Then FIELD is zero.
3916 There is always a maximum of one element in the chain LINK for unions
3917 (even if the initializer in a source program incorrectly contains
3918 more one). */
3919 for (cnt = 0;
3920 VEC_iterate (constructor_elt, CONSTRUCTOR_ELTS (exp), cnt, ce);
3921 cnt++, field = field ? TREE_CHAIN (field) : 0)
3923 tree val = ce->value;
3924 tree index = 0;
3926 /* The element in a union constructor specifies the proper field
3927 or index. */
3928 if ((TREE_CODE (type) == RECORD_TYPE || TREE_CODE (type) == UNION_TYPE
3929 || TREE_CODE (type) == QUAL_UNION_TYPE)
3930 && ce->index != 0)
3931 field = ce->index;
3933 else if (TREE_CODE (type) == ARRAY_TYPE)
3934 index = ce->index;
3936 #ifdef ASM_COMMENT_START
3937 if (field && flag_verbose_asm)
3938 fprintf (asm_out_file, "%s %s:\n",
3939 ASM_COMMENT_START,
3940 DECL_NAME (field)
3941 ? IDENTIFIER_POINTER (DECL_NAME (field))
3942 : "<anonymous>");
3943 #endif
3945 /* Eliminate the marker that makes a cast not be an lvalue. */
3946 if (val != 0)
3947 STRIP_NOPS (val);
3949 if (index && TREE_CODE (index) == RANGE_EXPR)
3951 unsigned HOST_WIDE_INT fieldsize
3952 = int_size_in_bytes (TREE_TYPE (type));
3953 HOST_WIDE_INT lo_index = tree_low_cst (TREE_OPERAND (index, 0), 0);
3954 HOST_WIDE_INT hi_index = tree_low_cst (TREE_OPERAND (index, 1), 0);
3955 HOST_WIDE_INT index;
3956 unsigned int align2 = min_align (align, fieldsize * BITS_PER_UNIT);
3958 for (index = lo_index; index <= hi_index; index++)
3960 /* Output the element's initial value. */
3961 if (val == 0)
3962 assemble_zeros (fieldsize);
3963 else
3964 output_constant (val, fieldsize, align2);
3966 /* Count its size. */
3967 total_bytes += fieldsize;
3970 else if (field == 0 || !DECL_BIT_FIELD (field))
3972 /* An element that is not a bit-field. */
3974 unsigned HOST_WIDE_INT fieldsize;
3975 /* Since this structure is static,
3976 we know the positions are constant. */
3977 HOST_WIDE_INT pos = field ? int_byte_position (field) : 0;
3978 unsigned int align2;
3980 if (index != 0)
3981 pos = (tree_low_cst (TYPE_SIZE_UNIT (TREE_TYPE (val)), 1)
3982 * (tree_low_cst (index, 0) - tree_low_cst (min_index, 0)));
3984 /* Output any buffered-up bit-fields preceding this element. */
3985 if (byte_buffer_in_use)
3987 assemble_integer (GEN_INT (byte), 1, BITS_PER_UNIT, 1);
3988 total_bytes++;
3989 byte_buffer_in_use = 0;
3992 /* Advance to offset of this element.
3993 Note no alignment needed in an array, since that is guaranteed
3994 if each element has the proper size. */
3995 if ((field != 0 || index != 0) && pos != total_bytes)
3997 gcc_assert (pos >= total_bytes);
3998 assemble_zeros (pos - total_bytes);
3999 total_bytes = pos;
4002 /* Find the alignment of this element. */
4003 align2 = min_align (align, BITS_PER_UNIT * pos);
4005 /* Determine size this element should occupy. */
4006 if (field)
4008 fieldsize = 0;
4010 /* If this is an array with an unspecified upper bound,
4011 the initializer determines the size. */
4012 /* ??? This ought to only checked if DECL_SIZE_UNIT is NULL,
4013 but we cannot do this until the deprecated support for
4014 initializing zero-length array members is removed. */
4015 if (TREE_CODE (TREE_TYPE (field)) == ARRAY_TYPE
4016 && TYPE_DOMAIN (TREE_TYPE (field))
4017 && ! TYPE_MAX_VALUE (TYPE_DOMAIN (TREE_TYPE (field))))
4019 fieldsize = array_size_for_constructor (val);
4020 /* Given a non-empty initialization, this field had
4021 better be last. */
4022 gcc_assert (!fieldsize || !TREE_CHAIN (field));
4024 else if (DECL_SIZE_UNIT (field))
4026 /* ??? This can't be right. If the decl size overflows
4027 a host integer we will silently emit no data. */
4028 if (host_integerp (DECL_SIZE_UNIT (field), 1))
4029 fieldsize = tree_low_cst (DECL_SIZE_UNIT (field), 1);
4032 else
4033 fieldsize = int_size_in_bytes (TREE_TYPE (type));
4035 /* Output the element's initial value. */
4036 if (val == 0)
4037 assemble_zeros (fieldsize);
4038 else
4039 output_constant (val, fieldsize, align2);
4041 /* Count its size. */
4042 total_bytes += fieldsize;
4044 else if (val != 0 && TREE_CODE (val) != INTEGER_CST)
4045 error ("invalid initial value for member %qs",
4046 IDENTIFIER_POINTER (DECL_NAME (field)));
4047 else
4049 /* Element that is a bit-field. */
4051 HOST_WIDE_INT next_offset = int_bit_position (field);
4052 HOST_WIDE_INT end_offset
4053 = (next_offset + tree_low_cst (DECL_SIZE (field), 1));
4055 if (val == 0)
4056 val = integer_zero_node;
4058 /* If this field does not start in this (or, next) byte,
4059 skip some bytes. */
4060 if (next_offset / BITS_PER_UNIT != total_bytes)
4062 /* Output remnant of any bit field in previous bytes. */
4063 if (byte_buffer_in_use)
4065 assemble_integer (GEN_INT (byte), 1, BITS_PER_UNIT, 1);
4066 total_bytes++;
4067 byte_buffer_in_use = 0;
4070 /* If still not at proper byte, advance to there. */
4071 if (next_offset / BITS_PER_UNIT != total_bytes)
4073 gcc_assert (next_offset / BITS_PER_UNIT >= total_bytes);
4074 assemble_zeros (next_offset / BITS_PER_UNIT - total_bytes);
4075 total_bytes = next_offset / BITS_PER_UNIT;
4079 if (! byte_buffer_in_use)
4080 byte = 0;
4082 /* We must split the element into pieces that fall within
4083 separate bytes, and combine each byte with previous or
4084 following bit-fields. */
4086 /* next_offset is the offset n fbits from the beginning of
4087 the structure to the next bit of this element to be processed.
4088 end_offset is the offset of the first bit past the end of
4089 this element. */
4090 while (next_offset < end_offset)
4092 int this_time;
4093 int shift;
4094 HOST_WIDE_INT value;
4095 HOST_WIDE_INT next_byte = next_offset / BITS_PER_UNIT;
4096 HOST_WIDE_INT next_bit = next_offset % BITS_PER_UNIT;
4098 /* Advance from byte to byte
4099 within this element when necessary. */
4100 while (next_byte != total_bytes)
4102 assemble_integer (GEN_INT (byte), 1, BITS_PER_UNIT, 1);
4103 total_bytes++;
4104 byte = 0;
4107 /* Number of bits we can process at once
4108 (all part of the same byte). */
4109 this_time = MIN (end_offset - next_offset,
4110 BITS_PER_UNIT - next_bit);
4111 if (BYTES_BIG_ENDIAN)
4113 /* On big-endian machine, take the most significant bits
4114 first (of the bits that are significant)
4115 and put them into bytes from the most significant end. */
4116 shift = end_offset - next_offset - this_time;
4118 /* Don't try to take a bunch of bits that cross
4119 the word boundary in the INTEGER_CST. We can
4120 only select bits from the LOW or HIGH part
4121 not from both. */
4122 if (shift < HOST_BITS_PER_WIDE_INT
4123 && shift + this_time > HOST_BITS_PER_WIDE_INT)
4125 this_time = shift + this_time - HOST_BITS_PER_WIDE_INT;
4126 shift = HOST_BITS_PER_WIDE_INT;
4129 /* Now get the bits from the appropriate constant word. */
4130 if (shift < HOST_BITS_PER_WIDE_INT)
4131 value = TREE_INT_CST_LOW (val);
4132 else
4134 gcc_assert (shift < 2 * HOST_BITS_PER_WIDE_INT);
4135 value = TREE_INT_CST_HIGH (val);
4136 shift -= HOST_BITS_PER_WIDE_INT;
4139 /* Get the result. This works only when:
4140 1 <= this_time <= HOST_BITS_PER_WIDE_INT. */
4141 byte |= (((value >> shift)
4142 & (((HOST_WIDE_INT) 2 << (this_time - 1)) - 1))
4143 << (BITS_PER_UNIT - this_time - next_bit));
4145 else
4147 /* On little-endian machines,
4148 take first the least significant bits of the value
4149 and pack them starting at the least significant
4150 bits of the bytes. */
4151 shift = next_offset - int_bit_position (field);
4153 /* Don't try to take a bunch of bits that cross
4154 the word boundary in the INTEGER_CST. We can
4155 only select bits from the LOW or HIGH part
4156 not from both. */
4157 if (shift < HOST_BITS_PER_WIDE_INT
4158 && shift + this_time > HOST_BITS_PER_WIDE_INT)
4159 this_time = (HOST_BITS_PER_WIDE_INT - shift);
4161 /* Now get the bits from the appropriate constant word. */
4162 if (shift < HOST_BITS_PER_WIDE_INT)
4163 value = TREE_INT_CST_LOW (val);
4164 else
4166 gcc_assert (shift < 2 * HOST_BITS_PER_WIDE_INT);
4167 value = TREE_INT_CST_HIGH (val);
4168 shift -= HOST_BITS_PER_WIDE_INT;
4171 /* Get the result. This works only when:
4172 1 <= this_time <= HOST_BITS_PER_WIDE_INT. */
4173 byte |= (((value >> shift)
4174 & (((HOST_WIDE_INT) 2 << (this_time - 1)) - 1))
4175 << next_bit);
4178 next_offset += this_time;
4179 byte_buffer_in_use = 1;
4184 if (byte_buffer_in_use)
4186 assemble_integer (GEN_INT (byte), 1, BITS_PER_UNIT, 1);
4187 total_bytes++;
4190 if ((unsigned HOST_WIDE_INT)total_bytes < size)
4191 assemble_zeros (size - total_bytes);
4194 /* This TREE_LIST contains any weak symbol declarations waiting
4195 to be emitted. */
4196 static GTY(()) tree weak_decls;
4198 /* Mark DECL as weak. */
4200 static void
4201 mark_weak (tree decl)
4203 DECL_WEAK (decl) = 1;
4205 if (DECL_RTL_SET_P (decl)
4206 && MEM_P (DECL_RTL (decl))
4207 && XEXP (DECL_RTL (decl), 0)
4208 && GET_CODE (XEXP (DECL_RTL (decl), 0)) == SYMBOL_REF)
4209 SYMBOL_REF_WEAK (XEXP (DECL_RTL (decl), 0)) = 1;
4212 /* Merge weak status between NEWDECL and OLDDECL. */
4214 void
4215 merge_weak (tree newdecl, tree olddecl)
4217 if (DECL_WEAK (newdecl) == DECL_WEAK (olddecl))
4219 if (DECL_WEAK (newdecl) && SUPPORTS_WEAK)
4221 tree *pwd;
4222 /* We put the NEWDECL on the weak_decls list at some point
4223 and OLDDECL as well. Keep just OLDDECL on the list. */
4224 for (pwd = &weak_decls; *pwd; pwd = &TREE_CHAIN (*pwd))
4225 if (TREE_VALUE (*pwd) == newdecl)
4227 *pwd = TREE_CHAIN (*pwd);
4228 break;
4231 return;
4234 if (DECL_WEAK (newdecl))
4236 tree wd;
4238 /* NEWDECL is weak, but OLDDECL is not. */
4240 /* If we already output the OLDDECL, we're in trouble; we can't
4241 go back and make it weak. This error cannot caught in
4242 declare_weak because the NEWDECL and OLDDECL was not yet
4243 been merged; therefore, TREE_ASM_WRITTEN was not set. */
4244 if (TREE_ASM_WRITTEN (olddecl))
4245 error ("weak declaration of %q+D must precede definition",
4246 newdecl);
4248 /* If we've already generated rtl referencing OLDDECL, we may
4249 have done so in a way that will not function properly with
4250 a weak symbol. */
4251 else if (TREE_USED (olddecl)
4252 && TREE_SYMBOL_REFERENCED (DECL_ASSEMBLER_NAME (olddecl)))
4253 warning (0, "weak declaration of %q+D after first use results "
4254 "in unspecified behavior", newdecl);
4256 if (SUPPORTS_WEAK)
4258 /* We put the NEWDECL on the weak_decls list at some point.
4259 Replace it with the OLDDECL. */
4260 for (wd = weak_decls; wd; wd = TREE_CHAIN (wd))
4261 if (TREE_VALUE (wd) == newdecl)
4263 TREE_VALUE (wd) = olddecl;
4264 break;
4266 /* We may not find the entry on the list. If NEWDECL is a
4267 weak alias, then we will have already called
4268 globalize_decl to remove the entry; in that case, we do
4269 not need to do anything. */
4272 /* Make the OLDDECL weak; it's OLDDECL that we'll be keeping. */
4273 mark_weak (olddecl);
4275 else
4276 /* OLDDECL was weak, but NEWDECL was not explicitly marked as
4277 weak. Just update NEWDECL to indicate that it's weak too. */
4278 mark_weak (newdecl);
4281 /* Declare DECL to be a weak symbol. */
4283 void
4284 declare_weak (tree decl)
4286 if (! TREE_PUBLIC (decl))
4287 error ("weak declaration of %q+D must be public", decl);
4288 else if (TREE_CODE (decl) == FUNCTION_DECL && TREE_ASM_WRITTEN (decl))
4289 error ("weak declaration of %q+D must precede definition", decl);
4290 else if (SUPPORTS_WEAK)
4292 if (! DECL_WEAK (decl))
4293 weak_decls = tree_cons (NULL, decl, weak_decls);
4295 else
4296 warning (0, "weak declaration of %q+D not supported", decl);
4298 mark_weak (decl);
4301 static void
4302 weak_finish_1 (tree decl)
4304 #if defined (ASM_WEAKEN_DECL) || defined (ASM_WEAKEN_LABEL)
4305 const char *const name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
4306 #endif
4308 if (! TREE_USED (decl))
4309 return;
4311 #ifdef ASM_WEAKEN_DECL
4312 ASM_WEAKEN_DECL (asm_out_file, decl, name, NULL);
4313 #else
4314 #ifdef ASM_WEAKEN_LABEL
4315 ASM_WEAKEN_LABEL (asm_out_file, name);
4316 #else
4317 #ifdef ASM_OUTPUT_WEAK_ALIAS
4319 static bool warn_once = 0;
4320 if (! warn_once)
4322 warning (0, "only weak aliases are supported in this configuration");
4323 warn_once = 1;
4325 return;
4327 #endif
4328 #endif
4329 #endif
4332 /* This TREE_LIST contains weakref targets. */
4334 static GTY(()) tree weakref_targets;
4336 /* Forward declaration. */
4337 static tree find_decl_and_mark_needed (tree decl, tree target);
4339 /* Emit any pending weak declarations. */
4341 void
4342 weak_finish (void)
4344 tree t;
4346 for (t = weakref_targets; t; t = TREE_CHAIN (t))
4348 tree alias_decl = TREE_PURPOSE (t);
4349 tree target = ultimate_transparent_alias_target (&TREE_VALUE (t));
4351 if (! TREE_SYMBOL_REFERENCED (DECL_ASSEMBLER_NAME (alias_decl)))
4352 /* Remove alias_decl from the weak list, but leave entries for
4353 the target alone. */
4354 target = NULL_TREE;
4355 #ifndef ASM_OUTPUT_WEAKREF
4356 else if (! TREE_SYMBOL_REFERENCED (target))
4358 /* Use ASM_WEAKEN_LABEL only if ASM_WEAKEN_DECL is not
4359 defined, otherwise we and weak_finish_1 would use a
4360 different macros. */
4361 # if defined ASM_WEAKEN_LABEL && ! defined ASM_WEAKEN_DECL
4362 ASM_WEAKEN_LABEL (asm_out_file, IDENTIFIER_POINTER (target));
4363 # else
4364 tree decl = find_decl_and_mark_needed (alias_decl, target);
4366 if (! decl)
4368 decl = build_decl (TREE_CODE (alias_decl), target,
4369 TREE_TYPE (alias_decl));
4371 DECL_EXTERNAL (decl) = 1;
4372 TREE_PUBLIC (decl) = 1;
4373 DECL_ARTIFICIAL (decl) = 1;
4374 TREE_NOTHROW (decl) = TREE_NOTHROW (alias_decl);
4375 TREE_USED (decl) = 1;
4378 weak_finish_1 (decl);
4379 # endif
4381 #endif
4384 tree *p;
4385 tree t2;
4387 /* Remove the alias and the target from the pending weak list
4388 so that we do not emit any .weak directives for the former,
4389 nor multiple .weak directives for the latter. */
4390 for (p = &weak_decls; (t2 = *p) ; )
4392 if (TREE_VALUE (t2) == alias_decl
4393 || target == DECL_ASSEMBLER_NAME (TREE_VALUE (t2)))
4394 *p = TREE_CHAIN (t2);
4395 else
4396 p = &TREE_CHAIN (t2);
4399 /* Remove other weakrefs to the same target, to speed things up. */
4400 for (p = &TREE_CHAIN (t); (t2 = *p) ; )
4402 if (target == ultimate_transparent_alias_target (&TREE_VALUE (t2)))
4403 *p = TREE_CHAIN (t2);
4404 else
4405 p = &TREE_CHAIN (t2);
4410 for (t = weak_decls; t; t = TREE_CHAIN (t))
4412 tree decl = TREE_VALUE (t);
4414 weak_finish_1 (decl);
4418 /* Emit the assembly bits to indicate that DECL is globally visible. */
4420 static void
4421 globalize_decl (tree decl)
4423 const char *name = XSTR (XEXP (DECL_RTL (decl), 0), 0);
4425 #if defined (ASM_WEAKEN_LABEL) || defined (ASM_WEAKEN_DECL)
4426 if (DECL_WEAK (decl))
4428 tree *p, t;
4430 #ifdef ASM_WEAKEN_DECL
4431 ASM_WEAKEN_DECL (asm_out_file, decl, name, 0);
4432 #else
4433 ASM_WEAKEN_LABEL (asm_out_file, name);
4434 #endif
4436 /* Remove this function from the pending weak list so that
4437 we do not emit multiple .weak directives for it. */
4438 for (p = &weak_decls; (t = *p) ; )
4440 if (DECL_ASSEMBLER_NAME (decl) == DECL_ASSEMBLER_NAME (TREE_VALUE (t)))
4441 *p = TREE_CHAIN (t);
4442 else
4443 p = &TREE_CHAIN (t);
4446 /* Remove weakrefs to the same target from the pending weakref
4447 list, for the same reason. */
4448 for (p = &weakref_targets; (t = *p) ; )
4450 if (DECL_ASSEMBLER_NAME (decl)
4451 == ultimate_transparent_alias_target (&TREE_VALUE (t)))
4452 *p = TREE_CHAIN (t);
4453 else
4454 p = &TREE_CHAIN (t);
4457 return;
4459 #elif defined(ASM_MAKE_LABEL_LINKONCE)
4460 if (DECL_ONE_ONLY (decl))
4461 ASM_MAKE_LABEL_LINKONCE (asm_out_file, name);
4462 #endif
4464 targetm.asm_out.globalize_label (asm_out_file, name);
4467 /* We have to be able to tell cgraph about the needed-ness of the target
4468 of an alias. This requires that the decl have been defined. Aliases
4469 that precede their definition have to be queued for later processing. */
4471 typedef struct alias_pair GTY(())
4473 tree decl;
4474 tree target;
4475 } alias_pair;
4477 /* Define gc'd vector type. */
4478 DEF_VEC_O(alias_pair);
4479 DEF_VEC_ALLOC_O(alias_pair,gc);
4481 static GTY(()) VEC(alias_pair,gc) *alias_pairs;
4483 /* Given an assembly name, find the decl it is associated with. At the
4484 same time, mark it needed for cgraph. */
4486 static tree
4487 find_decl_and_mark_needed (tree decl, tree target)
4489 struct cgraph_node *fnode = NULL;
4490 struct cgraph_varpool_node *vnode = NULL;
4492 if (TREE_CODE (decl) == FUNCTION_DECL)
4494 fnode = cgraph_node_for_asm (target);
4495 if (fnode == NULL)
4496 vnode = cgraph_varpool_node_for_asm (target);
4498 else
4500 vnode = cgraph_varpool_node_for_asm (target);
4501 if (vnode == NULL)
4502 fnode = cgraph_node_for_asm (target);
4505 if (fnode)
4507 /* We can't mark function nodes as used after cgraph global info
4508 is finished. This wouldn't generally be necessary, but C++
4509 virtual table thunks are introduced late in the game and
4510 might seem like they need marking, although in fact they
4511 don't. */
4512 if (! cgraph_global_info_ready)
4513 cgraph_mark_needed_node (fnode);
4514 return fnode->decl;
4516 else if (vnode)
4518 cgraph_varpool_mark_needed_node (vnode);
4519 return vnode->decl;
4521 else
4522 return NULL_TREE;
4525 /* Output the assembler code for a define (equate) using ASM_OUTPUT_DEF
4526 or ASM_OUTPUT_DEF_FROM_DECLS. The function defines the symbol whose
4527 tree node is DECL to have the value of the tree node TARGET. */
4529 static void
4530 do_assemble_alias (tree decl, tree target)
4532 if (TREE_ASM_WRITTEN (decl))
4533 return;
4535 TREE_ASM_WRITTEN (decl) = 1;
4536 TREE_ASM_WRITTEN (DECL_ASSEMBLER_NAME (decl)) = 1;
4538 if (lookup_attribute ("weakref", DECL_ATTRIBUTES (decl)))
4540 ultimate_transparent_alias_target (&target);
4542 if (!TREE_SYMBOL_REFERENCED (target))
4543 weakref_targets = tree_cons (decl, target, weakref_targets);
4545 #ifdef ASM_OUTPUT_WEAKREF
4546 ASM_OUTPUT_WEAKREF (asm_out_file, decl,
4547 IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl)),
4548 IDENTIFIER_POINTER (target));
4549 #else
4550 if (!SUPPORTS_WEAK)
4552 error ("%Jweakref is not supported in this configuration", decl);
4553 return;
4555 #endif
4556 return;
4559 #ifdef ASM_OUTPUT_DEF
4560 /* Make name accessible from other files, if appropriate. */
4562 if (TREE_PUBLIC (decl))
4564 globalize_decl (decl);
4565 maybe_assemble_visibility (decl);
4568 # ifdef ASM_OUTPUT_DEF_FROM_DECLS
4569 ASM_OUTPUT_DEF_FROM_DECLS (asm_out_file, decl, target);
4570 # else
4571 ASM_OUTPUT_DEF (asm_out_file,
4572 IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl)),
4573 IDENTIFIER_POINTER (target));
4574 # endif
4575 #elif defined (ASM_OUTPUT_WEAK_ALIAS) || defined (ASM_WEAKEN_DECL)
4577 const char *name;
4578 tree *p, t;
4580 name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
4581 # ifdef ASM_WEAKEN_DECL
4582 ASM_WEAKEN_DECL (asm_out_file, decl, name, IDENTIFIER_POINTER (target));
4583 # else
4584 ASM_OUTPUT_WEAK_ALIAS (asm_out_file, name, IDENTIFIER_POINTER (target));
4585 # endif
4586 /* Remove this function from the pending weak list so that
4587 we do not emit multiple .weak directives for it. */
4588 for (p = &weak_decls; (t = *p) ; )
4589 if (DECL_ASSEMBLER_NAME (decl) == DECL_ASSEMBLER_NAME (TREE_VALUE (t)))
4590 *p = TREE_CHAIN (t);
4591 else
4592 p = &TREE_CHAIN (t);
4594 /* Remove weakrefs to the same target from the pending weakref
4595 list, for the same reason. */
4596 for (p = &weakref_targets; (t = *p) ; )
4598 if (DECL_ASSEMBLER_NAME (decl)
4599 == ultimate_transparent_alias_target (&TREE_VALUE (t)))
4600 *p = TREE_CHAIN (t);
4601 else
4602 p = &TREE_CHAIN (t);
4605 #endif
4608 /* First pass of completing pending aliases. Make sure that cgraph knows
4609 which symbols will be required. */
4611 void
4612 finish_aliases_1 (void)
4614 unsigned i;
4615 alias_pair *p;
4617 for (i = 0; VEC_iterate (alias_pair, alias_pairs, i, p); i++)
4619 tree target_decl;
4621 target_decl = find_decl_and_mark_needed (p->decl, p->target);
4622 if (target_decl == NULL)
4624 if (! lookup_attribute ("weakref", DECL_ATTRIBUTES (p->decl)))
4625 error ("%q+D aliased to undefined symbol %qs",
4626 p->decl, IDENTIFIER_POINTER (p->target));
4628 else if (DECL_EXTERNAL (target_decl)
4629 && ! lookup_attribute ("weakref", DECL_ATTRIBUTES (p->decl)))
4630 error ("%q+D aliased to external symbol %qs",
4631 p->decl, IDENTIFIER_POINTER (p->target));
4635 /* Second pass of completing pending aliases. Emit the actual assembly.
4636 This happens at the end of compilation and thus it is assured that the
4637 target symbol has been emitted. */
4639 void
4640 finish_aliases_2 (void)
4642 unsigned i;
4643 alias_pair *p;
4645 for (i = 0; VEC_iterate (alias_pair, alias_pairs, i, p); i++)
4646 do_assemble_alias (p->decl, p->target);
4648 VEC_truncate (alias_pair, alias_pairs, 0);
4651 /* Emit an assembler directive to make the symbol for DECL an alias to
4652 the symbol for TARGET. */
4654 void
4655 assemble_alias (tree decl, tree target)
4657 tree target_decl;
4658 bool is_weakref = false;
4660 if (lookup_attribute ("weakref", DECL_ATTRIBUTES (decl)))
4662 tree alias = DECL_ASSEMBLER_NAME (decl);
4664 is_weakref = true;
4666 ultimate_transparent_alias_target (&target);
4668 if (alias == target)
4669 error ("weakref %q+D ultimately targets itself", decl);
4670 else
4672 #ifndef ASM_OUTPUT_WEAKREF
4673 IDENTIFIER_TRANSPARENT_ALIAS (alias) = 1;
4674 TREE_CHAIN (alias) = target;
4675 #endif
4677 if (TREE_PUBLIC (decl))
4678 error ("weakref %q+D must have static linkage", decl);
4680 else
4682 #if !defined (ASM_OUTPUT_DEF)
4683 # if !defined(ASM_OUTPUT_WEAK_ALIAS) && !defined (ASM_WEAKEN_DECL)
4684 error ("%Jalias definitions not supported in this configuration", decl);
4685 return;
4686 # else
4687 if (!DECL_WEAK (decl))
4689 error ("%Jonly weak aliases are supported in this configuration", decl);
4690 return;
4692 # endif
4693 #endif
4696 /* We must force creation of DECL_RTL for debug info generation, even though
4697 we don't use it here. */
4698 make_decl_rtl (decl);
4699 TREE_USED (decl) = 1;
4701 /* A quirk of the initial implementation of aliases required that the user
4702 add "extern" to all of them. Which is silly, but now historical. Do
4703 note that the symbol is in fact locally defined. */
4704 if (! is_weakref)
4705 DECL_EXTERNAL (decl) = 0;
4707 /* Allow aliases to aliases. */
4708 if (TREE_CODE (decl) == FUNCTION_DECL)
4709 cgraph_node (decl)->alias = true;
4710 else
4711 cgraph_varpool_node (decl)->alias = true;
4713 /* If the target has already been emitted, we don't have to queue the
4714 alias. This saves a tad o memory. */
4715 target_decl = find_decl_and_mark_needed (decl, target);
4716 if (target_decl && TREE_ASM_WRITTEN (target_decl))
4717 do_assemble_alias (decl, target);
4718 else
4720 alias_pair *p = VEC_safe_push (alias_pair, gc, alias_pairs, NULL);
4721 p->decl = decl;
4722 p->target = target;
4726 /* Emit an assembler directive to set symbol for DECL visibility to
4727 the visibility type VIS, which must not be VISIBILITY_DEFAULT. */
4729 void
4730 default_assemble_visibility (tree decl, int vis)
4732 static const char * const visibility_types[] = {
4733 NULL, "internal", "hidden", "protected"
4736 const char *name, *type;
4738 name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
4739 type = visibility_types[vis];
4741 #ifdef HAVE_GAS_HIDDEN
4742 fprintf (asm_out_file, "\t.%s\t", type);
4743 assemble_name (asm_out_file, name);
4744 fprintf (asm_out_file, "\n");
4745 #else
4746 warning (OPT_Wattributes, "visibility attribute not supported "
4747 "in this configuration; ignored");
4748 #endif
4751 /* A helper function to call assemble_visibility when needed for a decl. */
4753 static void
4754 maybe_assemble_visibility (tree decl)
4756 enum symbol_visibility vis = DECL_VISIBILITY (decl);
4758 if (vis != VISIBILITY_DEFAULT)
4759 targetm.asm_out.visibility (decl, vis);
4762 /* Returns 1 if the target configuration supports defining public symbols
4763 so that one of them will be chosen at link time instead of generating a
4764 multiply-defined symbol error, whether through the use of weak symbols or
4765 a target-specific mechanism for having duplicates discarded. */
4768 supports_one_only (void)
4770 if (SUPPORTS_ONE_ONLY)
4771 return 1;
4772 return SUPPORTS_WEAK;
4775 /* Set up DECL as a public symbol that can be defined in multiple
4776 translation units without generating a linker error. */
4778 void
4779 make_decl_one_only (tree decl)
4781 gcc_assert (TREE_CODE (decl) == VAR_DECL
4782 || TREE_CODE (decl) == FUNCTION_DECL);
4784 TREE_PUBLIC (decl) = 1;
4786 if (SUPPORTS_ONE_ONLY)
4788 #ifdef MAKE_DECL_ONE_ONLY
4789 MAKE_DECL_ONE_ONLY (decl);
4790 #endif
4791 DECL_ONE_ONLY (decl) = 1;
4793 else if (TREE_CODE (decl) == VAR_DECL
4794 && (DECL_INITIAL (decl) == 0 || DECL_INITIAL (decl) == error_mark_node))
4795 DECL_COMMON (decl) = 1;
4796 else
4798 gcc_assert (SUPPORTS_WEAK);
4799 DECL_WEAK (decl) = 1;
4803 void
4804 init_varasm_once (void)
4806 section_htab = htab_create_ggc (31, section_entry_hash,
4807 section_entry_eq, NULL);
4808 const_desc_htab = htab_create_ggc (1009, const_desc_hash,
4809 const_desc_eq, NULL);
4811 const_alias_set = new_alias_set ();
4813 #ifdef TEXT_SECTION_ASM_OP
4814 text_section = get_unnamed_section (SECTION_CODE, output_section_asm_op,
4815 TEXT_SECTION_ASM_OP);
4816 #endif
4818 #ifdef DATA_SECTION_ASM_OP
4819 data_section = get_unnamed_section (SECTION_WRITE, output_section_asm_op,
4820 DATA_SECTION_ASM_OP);
4821 #endif
4823 #ifdef SDATA_SECTION_ASM_OP
4824 sdata_section = get_unnamed_section (SECTION_WRITE, output_section_asm_op,
4825 SDATA_SECTION_ASM_OP);
4826 #endif
4828 #ifdef READONLY_DATA_SECTION_ASM_OP
4829 readonly_data_section = get_unnamed_section (0, output_section_asm_op,
4830 READONLY_DATA_SECTION_ASM_OP);
4831 #endif
4833 #ifdef CTORS_SECTION_ASM_OP
4834 ctors_section = get_unnamed_section (0, output_section_asm_op,
4835 CTORS_SECTION_ASM_OP);
4836 #endif
4838 #ifdef DTORS_SECTION_ASM_OP
4839 dtors_section = get_unnamed_section (0, output_section_asm_op,
4840 DTORS_SECTION_ASM_OP);
4841 #endif
4843 #ifdef BSS_SECTION_ASM_OP
4844 bss_section = get_unnamed_section (SECTION_WRITE | SECTION_BSS,
4845 output_section_asm_op,
4846 BSS_SECTION_ASM_OP);
4847 #endif
4849 #ifdef SBSS_SECTION_ASM_OP
4850 sbss_section = get_unnamed_section (SECTION_WRITE | SECTION_BSS,
4851 output_section_asm_op,
4852 SBSS_SECTION_ASM_OP);
4853 #endif
4855 targetm.asm_out.init_sections ();
4857 if (readonly_data_section == NULL)
4858 readonly_data_section = text_section;
4861 enum tls_model
4862 decl_default_tls_model (tree decl)
4864 enum tls_model kind;
4865 bool is_local;
4867 is_local = targetm.binds_local_p (decl);
4868 if (!flag_shlib)
4870 if (is_local)
4871 kind = TLS_MODEL_LOCAL_EXEC;
4872 else
4873 kind = TLS_MODEL_INITIAL_EXEC;
4876 /* Local dynamic is inefficient when we're not combining the
4877 parts of the address. */
4878 else if (optimize && is_local)
4879 kind = TLS_MODEL_LOCAL_DYNAMIC;
4880 else
4881 kind = TLS_MODEL_GLOBAL_DYNAMIC;
4882 if (kind < flag_tls_default)
4883 kind = flag_tls_default;
4885 return kind;
4888 /* Select a set of attributes for section NAME based on the properties
4889 of DECL and whether or not RELOC indicates that DECL's initializer
4890 might contain runtime relocations.
4892 We make the section read-only and executable for a function decl,
4893 read-only for a const data decl, and writable for a non-const data decl. */
4895 unsigned int
4896 default_section_type_flags (tree decl, const char *name, int reloc)
4898 return default_section_type_flags_1 (decl, name, reloc, flag_pic);
4901 unsigned int
4902 default_section_type_flags_1 (tree decl, const char *name, int reloc,
4903 int shlib)
4905 unsigned int flags;
4907 if (decl && TREE_CODE (decl) == FUNCTION_DECL)
4908 flags = SECTION_CODE;
4909 else if (decl && decl_readonly_section_1 (decl, reloc, shlib))
4910 flags = 0;
4911 else if (current_function_decl
4912 && cfun
4913 && cfun->unlikely_text_section_name
4914 && strcmp (name, cfun->unlikely_text_section_name) == 0)
4915 flags = SECTION_CODE;
4916 else if (!decl
4917 && (!current_function_decl || !cfun)
4918 && strcmp (name, UNLIKELY_EXECUTED_TEXT_SECTION_NAME) == 0)
4919 flags = SECTION_CODE;
4920 else
4921 flags = SECTION_WRITE;
4923 if (decl && DECL_ONE_ONLY (decl))
4924 flags |= SECTION_LINKONCE;
4926 if (decl && TREE_CODE (decl) == VAR_DECL && DECL_THREAD_LOCAL_P (decl))
4927 flags |= SECTION_TLS | SECTION_WRITE;
4929 if (strcmp (name, ".bss") == 0
4930 || strncmp (name, ".bss.", 5) == 0
4931 || strncmp (name, ".gnu.linkonce.b.", 16) == 0
4932 || strcmp (name, ".sbss") == 0
4933 || strncmp (name, ".sbss.", 6) == 0
4934 || strncmp (name, ".gnu.linkonce.sb.", 17) == 0)
4935 flags |= SECTION_BSS;
4937 if (strcmp (name, ".tdata") == 0
4938 || strncmp (name, ".tdata.", 7) == 0
4939 || strncmp (name, ".gnu.linkonce.td.", 17) == 0)
4940 flags |= SECTION_TLS;
4942 if (strcmp (name, ".tbss") == 0
4943 || strncmp (name, ".tbss.", 6) == 0
4944 || strncmp (name, ".gnu.linkonce.tb.", 17) == 0)
4945 flags |= SECTION_TLS | SECTION_BSS;
4947 /* These three sections have special ELF types. They are neither
4948 SHT_PROGBITS nor SHT_NOBITS, so when changing sections we don't
4949 want to print a section type (@progbits or @nobits). If someone
4950 is silly enough to emit code or TLS variables to one of these
4951 sections, then don't handle them specially. */
4952 if (!(flags & (SECTION_CODE | SECTION_BSS | SECTION_TLS))
4953 && (strcmp (name, ".init_array") == 0
4954 || strcmp (name, ".fini_array") == 0
4955 || strcmp (name, ".preinit_array") == 0))
4956 flags |= SECTION_NOTYPE;
4958 return flags;
4961 /* Output assembly to switch to section NAME with attribute FLAGS.
4962 Four variants for common object file formats. */
4964 void
4965 default_no_named_section (const char *name ATTRIBUTE_UNUSED,
4966 unsigned int flags ATTRIBUTE_UNUSED,
4967 tree decl ATTRIBUTE_UNUSED)
4969 /* Some object formats don't support named sections at all. The
4970 front-end should already have flagged this as an error. */
4971 gcc_unreachable ();
4974 void
4975 default_elf_asm_named_section (const char *name, unsigned int flags,
4976 tree decl ATTRIBUTE_UNUSED)
4978 char flagchars[10], *f = flagchars;
4980 /* If we have already declared this section, we can use an
4981 abbreviated form to switch back to it -- unless this section is
4982 part of a COMDAT groups, in which case GAS requires the full
4983 declaration every time. */
4984 if (!(HAVE_COMDAT_GROUP && (flags & SECTION_LINKONCE))
4985 && (flags & SECTION_DECLARED))
4987 fprintf (asm_out_file, "\t.section\t%s\n", name);
4988 return;
4991 if (!(flags & SECTION_DEBUG))
4992 *f++ = 'a';
4993 if (flags & SECTION_WRITE)
4994 *f++ = 'w';
4995 if (flags & SECTION_CODE)
4996 *f++ = 'x';
4997 if (flags & SECTION_SMALL)
4998 *f++ = 's';
4999 if (flags & SECTION_MERGE)
5000 *f++ = 'M';
5001 if (flags & SECTION_STRINGS)
5002 *f++ = 'S';
5003 if (flags & SECTION_TLS)
5004 *f++ = 'T';
5005 if (HAVE_COMDAT_GROUP && (flags & SECTION_LINKONCE))
5006 *f++ = 'G';
5007 *f = '\0';
5009 fprintf (asm_out_file, "\t.section\t%s,\"%s\"", name, flagchars);
5011 if (!(flags & SECTION_NOTYPE))
5013 const char *type;
5014 const char *format;
5016 if (flags & SECTION_BSS)
5017 type = "nobits";
5018 else
5019 type = "progbits";
5021 format = ",@%s";
5022 #ifdef ASM_COMMENT_START
5023 /* On platforms that use "@" as the assembly comment character,
5024 use "%" instead. */
5025 if (strcmp (ASM_COMMENT_START, "@") == 0)
5026 format = ",%%%s";
5027 #endif
5028 fprintf (asm_out_file, format, type);
5030 if (flags & SECTION_ENTSIZE)
5031 fprintf (asm_out_file, ",%d", flags & SECTION_ENTSIZE);
5032 if (HAVE_COMDAT_GROUP && (flags & SECTION_LINKONCE))
5033 fprintf (asm_out_file, ",%s,comdat",
5034 lang_hooks.decls.comdat_group (decl));
5037 putc ('\n', asm_out_file);
5040 void
5041 default_coff_asm_named_section (const char *name, unsigned int flags,
5042 tree decl ATTRIBUTE_UNUSED)
5044 char flagchars[8], *f = flagchars;
5046 if (flags & SECTION_WRITE)
5047 *f++ = 'w';
5048 if (flags & SECTION_CODE)
5049 *f++ = 'x';
5050 *f = '\0';
5052 fprintf (asm_out_file, "\t.section\t%s,\"%s\"\n", name, flagchars);
5055 void
5056 default_pe_asm_named_section (const char *name, unsigned int flags,
5057 tree decl)
5059 default_coff_asm_named_section (name, flags, decl);
5061 if (flags & SECTION_LINKONCE)
5063 /* Functions may have been compiled at various levels of
5064 optimization so we can't use `same_size' here.
5065 Instead, have the linker pick one. */
5066 fprintf (asm_out_file, "\t.linkonce %s\n",
5067 (flags & SECTION_CODE ? "discard" : "same_size"));
5071 /* The lame default section selector. */
5073 section *
5074 default_select_section (tree decl, int reloc,
5075 unsigned HOST_WIDE_INT align ATTRIBUTE_UNUSED)
5077 if (DECL_P (decl))
5079 if (decl_readonly_section (decl, reloc))
5080 return readonly_data_section;
5082 else if (TREE_CODE (decl) == CONSTRUCTOR)
5084 if (! ((flag_pic && reloc)
5085 || !TREE_READONLY (decl)
5086 || TREE_SIDE_EFFECTS (decl)
5087 || !TREE_CONSTANT (decl)))
5088 return readonly_data_section;
5090 else if (TREE_CODE (decl) == STRING_CST)
5091 return readonly_data_section;
5092 else if (! (flag_pic && reloc))
5093 return readonly_data_section;
5095 return data_section;
5098 enum section_category
5099 categorize_decl_for_section (tree decl, int reloc, int shlib)
5101 enum section_category ret;
5103 if (TREE_CODE (decl) == FUNCTION_DECL)
5104 return SECCAT_TEXT;
5105 else if (TREE_CODE (decl) == STRING_CST)
5107 if (flag_mudflap) /* or !flag_merge_constants */
5108 return SECCAT_RODATA;
5109 else
5110 return SECCAT_RODATA_MERGE_STR;
5112 else if (TREE_CODE (decl) == VAR_DECL)
5114 if (DECL_INITIAL (decl) == NULL
5115 || DECL_INITIAL (decl) == error_mark_node
5116 || (flag_zero_initialized_in_bss
5117 /* Leave constant zeroes in .rodata so they can be shared. */
5118 && !TREE_READONLY (decl)
5119 && initializer_zerop (DECL_INITIAL (decl))))
5120 ret = SECCAT_BSS;
5121 else if (! TREE_READONLY (decl)
5122 || TREE_SIDE_EFFECTS (decl)
5123 || ! TREE_CONSTANT (DECL_INITIAL (decl)))
5125 if (shlib && (reloc & 2))
5126 ret = SECCAT_DATA_REL;
5127 else if (shlib && reloc)
5128 ret = SECCAT_DATA_REL_LOCAL;
5129 else
5130 ret = SECCAT_DATA;
5132 else if (shlib && (reloc & 2))
5133 ret = SECCAT_DATA_REL_RO;
5134 else if (shlib && reloc)
5135 ret = SECCAT_DATA_REL_RO_LOCAL;
5136 else if (reloc || flag_merge_constants < 2)
5137 /* C and C++ don't allow different variables to share the same
5138 location. -fmerge-all-constants allows even that (at the
5139 expense of not conforming). */
5140 ret = SECCAT_RODATA;
5141 else if (TREE_CODE (DECL_INITIAL (decl)) == STRING_CST)
5142 ret = SECCAT_RODATA_MERGE_STR_INIT;
5143 else
5144 ret = SECCAT_RODATA_MERGE_CONST;
5146 else if (TREE_CODE (decl) == CONSTRUCTOR)
5148 if ((shlib && reloc)
5149 || TREE_SIDE_EFFECTS (decl)
5150 || ! TREE_CONSTANT (decl))
5151 ret = SECCAT_DATA;
5152 else
5153 ret = SECCAT_RODATA;
5155 else
5156 ret = SECCAT_RODATA;
5158 /* There are no read-only thread-local sections. */
5159 if (TREE_CODE (decl) == VAR_DECL && DECL_THREAD_LOCAL_P (decl))
5161 /* Note that this would be *just* SECCAT_BSS, except that there's
5162 no concept of a read-only thread-local-data section. */
5163 if (ret == SECCAT_BSS
5164 || (flag_zero_initialized_in_bss
5165 && initializer_zerop (DECL_INITIAL (decl))))
5166 ret = SECCAT_TBSS;
5167 else
5168 ret = SECCAT_TDATA;
5171 /* If the target uses small data sections, select it. */
5172 else if (targetm.in_small_data_p (decl))
5174 if (ret == SECCAT_BSS)
5175 ret = SECCAT_SBSS;
5176 else if (targetm.have_srodata_section && ret == SECCAT_RODATA)
5177 ret = SECCAT_SRODATA;
5178 else
5179 ret = SECCAT_SDATA;
5182 return ret;
5185 bool
5186 decl_readonly_section (tree decl, int reloc)
5188 return decl_readonly_section_1 (decl, reloc, flag_pic);
5191 bool
5192 decl_readonly_section_1 (tree decl, int reloc, int shlib)
5194 switch (categorize_decl_for_section (decl, reloc, shlib))
5196 case SECCAT_RODATA:
5197 case SECCAT_RODATA_MERGE_STR:
5198 case SECCAT_RODATA_MERGE_STR_INIT:
5199 case SECCAT_RODATA_MERGE_CONST:
5200 case SECCAT_SRODATA:
5201 return true;
5202 break;
5203 default:
5204 return false;
5205 break;
5209 /* Select a section based on the above categorization. */
5211 section *
5212 default_elf_select_section (tree decl, int reloc,
5213 unsigned HOST_WIDE_INT align)
5215 return default_elf_select_section_1 (decl, reloc, align, flag_pic);
5218 section *
5219 default_elf_select_section_1 (tree decl, int reloc,
5220 unsigned HOST_WIDE_INT align, int shlib)
5222 const char *sname;
5223 switch (categorize_decl_for_section (decl, reloc, shlib))
5225 case SECCAT_TEXT:
5226 /* We're not supposed to be called on FUNCTION_DECLs. */
5227 gcc_unreachable ();
5228 case SECCAT_RODATA:
5229 return readonly_data_section;
5230 case SECCAT_RODATA_MERGE_STR:
5231 return mergeable_string_section (decl, align, 0);
5232 case SECCAT_RODATA_MERGE_STR_INIT:
5233 return mergeable_string_section (DECL_INITIAL (decl), align, 0);
5234 case SECCAT_RODATA_MERGE_CONST:
5235 return mergeable_constant_section (DECL_MODE (decl), align, 0);
5236 case SECCAT_SRODATA:
5237 sname = ".sdata2";
5238 break;
5239 case SECCAT_DATA:
5240 return data_section;
5241 case SECCAT_DATA_REL:
5242 sname = ".data.rel";
5243 break;
5244 case SECCAT_DATA_REL_LOCAL:
5245 sname = ".data.rel.local";
5246 break;
5247 case SECCAT_DATA_REL_RO:
5248 sname = ".data.rel.ro";
5249 break;
5250 case SECCAT_DATA_REL_RO_LOCAL:
5251 sname = ".data.rel.ro.local";
5252 break;
5253 case SECCAT_SDATA:
5254 sname = ".sdata";
5255 break;
5256 case SECCAT_TDATA:
5257 sname = ".tdata";
5258 break;
5259 case SECCAT_BSS:
5260 if (bss_section)
5261 return bss_section;
5262 sname = ".bss";
5263 break;
5264 case SECCAT_SBSS:
5265 sname = ".sbss";
5266 break;
5267 case SECCAT_TBSS:
5268 sname = ".tbss";
5269 break;
5270 default:
5271 gcc_unreachable ();
5274 if (!DECL_P (decl))
5275 decl = NULL_TREE;
5276 return get_named_section (decl, sname, reloc);
5279 /* Construct a unique section name based on the decl name and the
5280 categorization performed above. */
5282 void
5283 default_unique_section (tree decl, int reloc)
5285 default_unique_section_1 (decl, reloc, flag_pic);
5288 void
5289 default_unique_section_1 (tree decl, int reloc, int shlib)
5291 /* We only need to use .gnu.linkonce if we don't have COMDAT groups. */
5292 bool one_only = DECL_ONE_ONLY (decl) && !HAVE_COMDAT_GROUP;
5293 const char *prefix, *name;
5294 size_t nlen, plen;
5295 char *string;
5297 switch (categorize_decl_for_section (decl, reloc, shlib))
5299 case SECCAT_TEXT:
5300 prefix = one_only ? ".gnu.linkonce.t." : ".text.";
5301 break;
5302 case SECCAT_RODATA:
5303 case SECCAT_RODATA_MERGE_STR:
5304 case SECCAT_RODATA_MERGE_STR_INIT:
5305 case SECCAT_RODATA_MERGE_CONST:
5306 prefix = one_only ? ".gnu.linkonce.r." : ".rodata.";
5307 break;
5308 case SECCAT_SRODATA:
5309 prefix = one_only ? ".gnu.linkonce.s2." : ".sdata2.";
5310 break;
5311 case SECCAT_DATA:
5312 prefix = one_only ? ".gnu.linkonce.d." : ".data.";
5313 break;
5314 case SECCAT_DATA_REL:
5315 prefix = one_only ? ".gnu.linkonce.d.rel." : ".data.rel.";
5316 break;
5317 case SECCAT_DATA_REL_LOCAL:
5318 prefix = one_only ? ".gnu.linkonce.d.rel.local." : ".data.rel.local.";
5319 break;
5320 case SECCAT_DATA_REL_RO:
5321 prefix = one_only ? ".gnu.linkonce.d.rel.ro." : ".data.rel.ro.";
5322 break;
5323 case SECCAT_DATA_REL_RO_LOCAL:
5324 prefix = one_only ? ".gnu.linkonce.d.rel.ro.local."
5325 : ".data.rel.ro.local.";
5326 break;
5327 case SECCAT_SDATA:
5328 prefix = one_only ? ".gnu.linkonce.s." : ".sdata.";
5329 break;
5330 case SECCAT_BSS:
5331 prefix = one_only ? ".gnu.linkonce.b." : ".bss.";
5332 break;
5333 case SECCAT_SBSS:
5334 prefix = one_only ? ".gnu.linkonce.sb." : ".sbss.";
5335 break;
5336 case SECCAT_TDATA:
5337 prefix = one_only ? ".gnu.linkonce.td." : ".tdata.";
5338 break;
5339 case SECCAT_TBSS:
5340 prefix = one_only ? ".gnu.linkonce.tb." : ".tbss.";
5341 break;
5342 default:
5343 gcc_unreachable ();
5345 plen = strlen (prefix);
5347 name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
5348 name = targetm.strip_name_encoding (name);
5349 nlen = strlen (name);
5351 string = alloca (nlen + plen + 1);
5352 memcpy (string, prefix, plen);
5353 memcpy (string + plen, name, nlen + 1);
5355 DECL_SECTION_NAME (decl) = build_string (nlen + plen, string);
5358 section *
5359 default_select_rtx_section (enum machine_mode mode ATTRIBUTE_UNUSED,
5360 rtx x,
5361 unsigned HOST_WIDE_INT align ATTRIBUTE_UNUSED)
5363 if (flag_pic)
5364 switch (GET_CODE (x))
5366 case CONST:
5367 case SYMBOL_REF:
5368 case LABEL_REF:
5369 return data_section;
5371 default:
5372 break;
5375 return readonly_data_section;
5378 section *
5379 default_elf_select_rtx_section (enum machine_mode mode, rtx x,
5380 unsigned HOST_WIDE_INT align)
5382 /* ??? Handle small data here somehow. */
5384 if (flag_pic)
5385 switch (GET_CODE (x))
5387 case CONST:
5388 case SYMBOL_REF:
5389 return get_named_section (NULL, ".data.rel.ro", 3);
5391 case LABEL_REF:
5392 return get_named_section (NULL, ".data.rel.ro.local", 1);
5394 default:
5395 break;
5398 return mergeable_constant_section (mode, align, 0);
5401 /* Set the generally applicable flags on the SYMBOL_REF for EXP. */
5403 void
5404 default_encode_section_info (tree decl, rtx rtl, int first ATTRIBUTE_UNUSED)
5406 rtx symbol;
5407 int flags;
5409 /* Careful not to prod global register variables. */
5410 if (!MEM_P (rtl))
5411 return;
5412 symbol = XEXP (rtl, 0);
5413 if (GET_CODE (symbol) != SYMBOL_REF)
5414 return;
5416 flags = 0;
5417 if (TREE_CODE (decl) == FUNCTION_DECL)
5418 flags |= SYMBOL_FLAG_FUNCTION;
5419 if (targetm.binds_local_p (decl))
5420 flags |= SYMBOL_FLAG_LOCAL;
5421 if (TREE_CODE (decl) == VAR_DECL && DECL_THREAD_LOCAL_P (decl))
5422 flags |= DECL_TLS_MODEL (decl) << SYMBOL_FLAG_TLS_SHIFT;
5423 else if (targetm.in_small_data_p (decl))
5424 flags |= SYMBOL_FLAG_SMALL;
5425 /* ??? Why is DECL_EXTERNAL ever set for non-PUBLIC names? Without
5426 being PUBLIC, the thing *must* be defined in this translation unit.
5427 Prevent this buglet from being propagated into rtl code as well. */
5428 if (DECL_P (decl) && DECL_EXTERNAL (decl) && TREE_PUBLIC (decl))
5429 flags |= SYMBOL_FLAG_EXTERNAL;
5431 SYMBOL_REF_FLAGS (symbol) = flags;
5434 /* By default, we do nothing for encode_section_info, so we need not
5435 do anything but discard the '*' marker. */
5437 const char *
5438 default_strip_name_encoding (const char *str)
5440 return str + (*str == '*');
5443 /* Assume ELF-ish defaults, since that's pretty much the most liberal
5444 wrt cross-module name binding. */
5446 bool
5447 default_binds_local_p (tree exp)
5449 return default_binds_local_p_1 (exp, flag_shlib);
5452 bool
5453 default_binds_local_p_1 (tree exp, int shlib)
5455 bool local_p;
5457 /* A non-decl is an entry in the constant pool. */
5458 if (!DECL_P (exp))
5459 local_p = true;
5460 /* Weakrefs may not bind locally, even though the weakref itself is
5461 always static and therefore local. */
5462 else if (lookup_attribute ("weakref", DECL_ATTRIBUTES (exp)))
5463 local_p = false;
5464 /* Static variables are always local. */
5465 else if (! TREE_PUBLIC (exp))
5466 local_p = true;
5467 /* A variable is local if the user has said explicitly that it will
5468 be. */
5469 else if (DECL_VISIBILITY_SPECIFIED (exp)
5470 && DECL_VISIBILITY (exp) != VISIBILITY_DEFAULT)
5471 local_p = true;
5472 /* Variables defined outside this object might not be local. */
5473 else if (DECL_EXTERNAL (exp))
5474 local_p = false;
5475 /* If defined in this object and visibility is not default, must be
5476 local. */
5477 else if (DECL_VISIBILITY (exp) != VISIBILITY_DEFAULT)
5478 local_p = true;
5479 /* Default visibility weak data can be overridden by a strong symbol
5480 in another module and so are not local. */
5481 else if (DECL_WEAK (exp))
5482 local_p = false;
5483 /* If PIC, then assume that any global name can be overridden by
5484 symbols resolved from other modules. */
5485 else if (shlib)
5486 local_p = false;
5487 /* Uninitialized COMMON variable may be unified with symbols
5488 resolved from other modules. */
5489 else if (DECL_COMMON (exp)
5490 && (DECL_INITIAL (exp) == NULL
5491 || DECL_INITIAL (exp) == error_mark_node))
5492 local_p = false;
5493 /* Otherwise we're left with initialized (or non-common) global data
5494 which is of necessity defined locally. */
5495 else
5496 local_p = true;
5498 return local_p;
5501 /* Determine whether or not a pointer mode is valid. Assume defaults
5502 of ptr_mode or Pmode - can be overridden. */
5503 bool
5504 default_valid_pointer_mode (enum machine_mode mode)
5506 return (mode == ptr_mode || mode == Pmode);
5509 /* Default function to output code that will globalize a label. A
5510 target must define GLOBAL_ASM_OP or provide its own function to
5511 globalize a label. */
5512 #ifdef GLOBAL_ASM_OP
5513 void
5514 default_globalize_label (FILE * stream, const char *name)
5516 fputs (GLOBAL_ASM_OP, stream);
5517 assemble_name (stream, name);
5518 putc ('\n', stream);
5520 #endif /* GLOBAL_ASM_OP */
5522 /* Default function to output a label for unwind information. The
5523 default is to do nothing. A target that needs nonlocal labels for
5524 unwind information must provide its own function to do this. */
5525 void
5526 default_emit_unwind_label (FILE * stream ATTRIBUTE_UNUSED,
5527 tree decl ATTRIBUTE_UNUSED,
5528 int for_eh ATTRIBUTE_UNUSED,
5529 int empty ATTRIBUTE_UNUSED)
5533 /* Default function to output a label to divide up the exception table.
5534 The default is to do nothing. A target that needs/wants to divide
5535 up the table must provide it's own function to do this. */
5536 void
5537 default_emit_except_table_label (FILE * stream ATTRIBUTE_UNUSED)
5541 /* This is how to output an internal numbered label where PREFIX is
5542 the class of label and LABELNO is the number within the class. */
5544 void
5545 default_internal_label (FILE *stream, const char *prefix,
5546 unsigned long labelno)
5548 char *const buf = alloca (40 + strlen (prefix));
5549 ASM_GENERATE_INTERNAL_LABEL (buf, prefix, labelno);
5550 ASM_OUTPUT_INTERNAL_LABEL (stream, buf);
5553 /* This is the default behavior at the beginning of a file. It's
5554 controlled by two other target-hook toggles. */
5555 void
5556 default_file_start (void)
5558 if (targetm.file_start_app_off && !flag_verbose_asm)
5559 fputs (ASM_APP_OFF, asm_out_file);
5561 if (targetm.file_start_file_directive)
5562 output_file_directive (asm_out_file, main_input_filename);
5565 /* This is a generic routine suitable for use as TARGET_ASM_FILE_END
5566 which emits a special section directive used to indicate whether or
5567 not this object file needs an executable stack. This is primarily
5568 a GNU extension to ELF but could be used on other targets. */
5570 int trampolines_created;
5572 void
5573 file_end_indicate_exec_stack (void)
5575 unsigned int flags = SECTION_DEBUG;
5576 if (trampolines_created)
5577 flags |= SECTION_CODE;
5579 switch_to_section (get_section (".note.GNU-stack", flags, NULL));
5582 /* Output DIRECTIVE (a C string) followed by a newline. This is used as
5583 a get_unnamed_section callback. */
5585 void
5586 output_section_asm_op (const void *directive)
5588 fprintf (asm_out_file, "%s\n", (const char *) directive);
5591 /* Emit assembly code to switch to section NEW_SECTION. Do nothing if
5592 the current section is NEW_SECTION. */
5594 void
5595 switch_to_section (section *new_section)
5597 if (in_section == new_section)
5598 return;
5600 if (new_section->common.flags & SECTION_FORGET)
5601 in_section = NULL;
5602 else
5603 in_section = new_section;
5605 if (new_section->common.flags & SECTION_NAMED)
5607 if (cfun
5608 && !cfun->unlikely_text_section_name
5609 && strcmp (new_section->named.name,
5610 UNLIKELY_EXECUTED_TEXT_SECTION_NAME) == 0)
5611 cfun->unlikely_text_section_name = UNLIKELY_EXECUTED_TEXT_SECTION_NAME;
5613 targetm.asm_out.named_section (new_section->named.name,
5614 new_section->named.common.flags,
5615 new_section->named.decl);
5617 else
5618 new_section->unnamed.callback (new_section->unnamed.data);
5620 new_section->common.flags |= SECTION_DECLARED;
5623 #include "gt-varasm.h"