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[official-gcc.git] / gcc / varasm.c
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1 /* Output variables, constants and external declarations, for GNU compiler.
2 Copyright (C) 1987, 1988, 1989, 1992, 1993, 1994, 1995, 1996, 1997,
3 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005
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 if (decl)
253 error ("%+D causes a section type conflict", decl);
254 else
255 gcc_unreachable ();
258 return sect;
261 static void
262 initialize_cold_section_name (void)
264 const char *stripped_name;
265 char *name, *buffer;
266 tree dsn;
268 gcc_assert (cfun && current_function_decl);
269 if (cfun->unlikely_text_section_name)
270 return;
272 dsn = DECL_SECTION_NAME (current_function_decl);
273 if (flag_function_sections && dsn)
275 name = alloca (TREE_STRING_LENGTH (dsn) + 1);
276 memcpy (name, TREE_STRING_POINTER (dsn), TREE_STRING_LENGTH (dsn) + 1);
278 stripped_name = targetm.strip_name_encoding (name);
280 buffer = ACONCAT ((stripped_name, "_unlikely", NULL));
281 cfun->unlikely_text_section_name = ggc_strdup (buffer);
283 else
284 cfun->unlikely_text_section_name = UNLIKELY_EXECUTED_TEXT_SECTION_NAME;
287 /* Tell assembler to switch to unlikely-to-be-executed text section. */
289 section *
290 unlikely_text_section (void)
292 if (cfun)
294 if (!cfun->unlikely_text_section_name)
295 initialize_cold_section_name ();
297 return get_named_section (NULL, cfun->unlikely_text_section_name, 0);
299 else
300 return get_named_section (NULL, UNLIKELY_EXECUTED_TEXT_SECTION_NAME, 0);
303 /* When called within a function context, return true if the function
304 has been assigned a cold text section and if SECT is that section.
305 When called outside a function context, return true if SECT is the
306 default cold section. */
308 bool
309 unlikely_text_section_p (section *sect)
311 const char *name;
313 if (cfun)
314 name = cfun->unlikely_text_section_name;
315 else
316 name = UNLIKELY_EXECUTED_TEXT_SECTION_NAME;
318 return (name
319 && sect
320 && (sect->common.flags & SECTION_NAMED) != 0
321 && strcmp (name, sect->named.name) == 0);
324 /* Return a section with a particular name and with whatever SECTION_*
325 flags section_type_flags deems appropriate. The name of the section
326 is taken from NAME if nonnull, otherwise it is taken from DECL's
327 DECL_SECTION_NAME. DECL is the decl associated with the section
328 (see the section comment for details) and RELOC is as for
329 section_type_flags. */
331 section *
332 get_named_section (tree decl, const char *name, int reloc)
334 unsigned int flags;
336 gcc_assert (!decl || DECL_P (decl));
337 if (name == NULL)
338 name = TREE_STRING_POINTER (DECL_SECTION_NAME (decl));
340 flags = targetm.section_type_flags (decl, name, reloc);
342 return get_section (name, flags, decl);
345 /* If required, set DECL_SECTION_NAME to a unique name. */
347 void
348 resolve_unique_section (tree decl, int reloc ATTRIBUTE_UNUSED,
349 int flag_function_or_data_sections)
351 if (DECL_SECTION_NAME (decl) == NULL_TREE
352 && targetm.have_named_sections
353 && (flag_function_or_data_sections
354 || DECL_ONE_ONLY (decl)))
355 targetm.asm_out.unique_section (decl, reloc);
358 #ifdef BSS_SECTION_ASM_OP
360 #ifdef ASM_OUTPUT_BSS
362 /* Utility function for ASM_OUTPUT_BSS for targets to use if
363 they don't support alignments in .bss.
364 ??? It is believed that this function will work in most cases so such
365 support is localized here. */
367 static void
368 asm_output_bss (FILE *file, tree decl ATTRIBUTE_UNUSED,
369 const char *name,
370 unsigned HOST_WIDE_INT size ATTRIBUTE_UNUSED,
371 unsigned HOST_WIDE_INT rounded)
373 targetm.asm_out.globalize_label (file, name);
374 switch_to_section (bss_section);
375 #ifdef ASM_DECLARE_OBJECT_NAME
376 last_assemble_variable_decl = decl;
377 ASM_DECLARE_OBJECT_NAME (file, name, decl);
378 #else
379 /* Standard thing is just output label for the object. */
380 ASM_OUTPUT_LABEL (file, name);
381 #endif /* ASM_DECLARE_OBJECT_NAME */
382 ASM_OUTPUT_SKIP (file, rounded ? rounded : 1);
385 #endif
387 #ifdef ASM_OUTPUT_ALIGNED_BSS
389 /* Utility function for targets to use in implementing
390 ASM_OUTPUT_ALIGNED_BSS.
391 ??? It is believed that this function will work in most cases so such
392 support is localized here. */
394 static void
395 asm_output_aligned_bss (FILE *file, tree decl ATTRIBUTE_UNUSED,
396 const char *name, unsigned HOST_WIDE_INT size,
397 int align)
399 switch_to_section (bss_section);
400 ASM_OUTPUT_ALIGN (file, floor_log2 (align / BITS_PER_UNIT));
401 #ifdef ASM_DECLARE_OBJECT_NAME
402 last_assemble_variable_decl = decl;
403 ASM_DECLARE_OBJECT_NAME (file, name, decl);
404 #else
405 /* Standard thing is just output label for the object. */
406 ASM_OUTPUT_LABEL (file, name);
407 #endif /* ASM_DECLARE_OBJECT_NAME */
408 ASM_OUTPUT_SKIP (file, size ? size : 1);
411 #endif
413 #endif /* BSS_SECTION_ASM_OP */
415 #ifndef USE_SELECT_SECTION_FOR_FUNCTIONS
416 /* Return the hot section for function DECL. Return text_section for
417 null DECLs. */
419 static section *
420 hot_function_section (tree decl)
422 if (decl != NULL_TREE
423 && DECL_SECTION_NAME (decl) != NULL_TREE
424 && targetm.have_named_sections)
425 return get_named_section (decl, NULL, 0);
426 else
427 return text_section;
429 #endif
431 /* Return the section for function DECL.
433 If DECL is NULL_TREE, return the text section. We can be passed
434 NULL_TREE under some circumstances by dbxout.c at least. */
436 section *
437 function_section (tree decl)
439 int reloc = 0;
441 if (first_function_block_is_cold)
442 reloc = 1;
444 #ifdef USE_SELECT_SECTION_FOR_FUNCTIONS
445 return targetm.asm_out.select_section (decl, reloc, DECL_ALIGN (decl));
446 #else
447 return hot_function_section (decl);
448 #endif
451 section *
452 current_function_section (void)
454 #ifdef USE_SELECT_SECTION_FOR_FUNCTIONS
455 return targetm.asm_out.select_section (current_function_decl,
456 in_cold_section_p,
457 DECL_ALIGN (current_function_decl));
458 #else
459 return (in_cold_section_p
460 ? unlikely_text_section ()
461 : hot_function_section (current_function_decl));
462 #endif
465 /* Return the read-only data section associated with function DECL. */
467 section *
468 default_function_rodata_section (tree decl)
470 if (decl != NULL_TREE && DECL_SECTION_NAME (decl))
472 const char *name = TREE_STRING_POINTER (DECL_SECTION_NAME (decl));
474 if (DECL_ONE_ONLY (decl) && HAVE_COMDAT_GROUP)
476 size_t len = strlen (name) + 3;
477 char* rname = alloca (len);
479 strcpy (rname, ".rodata");
480 strcat (rname, name + 5);
481 return get_section (rname, SECTION_LINKONCE, decl);
483 /* For .gnu.linkonce.t.foo we want to use .gnu.linkonce.r.foo. */
484 else if (DECL_ONE_ONLY (decl)
485 && strncmp (name, ".gnu.linkonce.t.", 16) == 0)
487 size_t len = strlen (name) + 1;
488 char *rname = alloca (len);
490 memcpy (rname, name, len);
491 rname[14] = 'r';
492 return get_section (rname, SECTION_LINKONCE, decl);
494 /* For .text.foo we want to use .rodata.foo. */
495 else if (flag_function_sections && flag_data_sections
496 && strncmp (name, ".text.", 6) == 0)
498 size_t len = strlen (name) + 1;
499 char *rname = alloca (len + 2);
501 memcpy (rname, ".rodata", 7);
502 memcpy (rname + 7, name + 5, len - 5);
503 return get_section (rname, 0, decl);
507 return readonly_data_section;
510 /* Return the read-only data section associated with function DECL
511 for targets where that section should be always the single
512 readonly data section. */
514 section *
515 default_no_function_rodata_section (tree decl ATTRIBUTE_UNUSED)
517 return readonly_data_section;
520 /* Switch to section for variable DECL. RELOC is the same as the
521 argument to SELECT_SECTION. */
523 void
524 variable_section (tree decl, int reloc)
526 if (IN_NAMED_SECTION (decl))
527 switch_to_section (get_named_section (decl, NULL, reloc));
528 else
529 switch_to_section (targetm.asm_out.select_section (decl, reloc,
530 DECL_ALIGN (decl)));
533 /* Return the section to use for string merging. */
535 static section *
536 mergeable_string_section (tree decl ATTRIBUTE_UNUSED,
537 unsigned HOST_WIDE_INT align ATTRIBUTE_UNUSED,
538 unsigned int flags ATTRIBUTE_UNUSED)
540 if (HAVE_GAS_SHF_MERGE && flag_merge_constants
541 && TREE_CODE (decl) == STRING_CST
542 && TREE_CODE (TREE_TYPE (decl)) == ARRAY_TYPE
543 && align <= 256
544 && TREE_STRING_LENGTH (decl) >= int_size_in_bytes (TREE_TYPE (decl)))
546 enum machine_mode mode;
547 unsigned int modesize;
548 const char *str;
549 int i, j, len, unit;
550 char name[30];
552 mode = TYPE_MODE (TREE_TYPE (TREE_TYPE (decl)));
553 modesize = GET_MODE_BITSIZE (mode);
554 if (modesize >= 8 && modesize <= 256
555 && (modesize & (modesize - 1)) == 0)
557 if (align < modesize)
558 align = modesize;
560 str = TREE_STRING_POINTER (decl);
561 len = TREE_STRING_LENGTH (decl);
562 unit = GET_MODE_SIZE (mode);
564 /* Check for embedded NUL characters. */
565 for (i = 0; i < len; i += unit)
567 for (j = 0; j < unit; j++)
568 if (str[i + j] != '\0')
569 break;
570 if (j == unit)
571 break;
573 if (i == len - unit)
575 sprintf (name, ".rodata.str%d.%d", modesize / 8,
576 (int) (align / 8));
577 flags |= (modesize / 8) | SECTION_MERGE | SECTION_STRINGS;
578 return get_section (name, flags, NULL);
583 return readonly_data_section;
586 /* Return the section to use for constant merging. */
588 section *
589 mergeable_constant_section (enum machine_mode mode ATTRIBUTE_UNUSED,
590 unsigned HOST_WIDE_INT align ATTRIBUTE_UNUSED,
591 unsigned int flags ATTRIBUTE_UNUSED)
593 unsigned int modesize = GET_MODE_BITSIZE (mode);
595 if (HAVE_GAS_SHF_MERGE && flag_merge_constants
596 && mode != VOIDmode
597 && mode != BLKmode
598 && modesize <= align
599 && align >= 8
600 && align <= 256
601 && (align & (align - 1)) == 0)
603 char name[24];
605 sprintf (name, ".rodata.cst%d", (int) (align / 8));
606 flags |= (align / 8) | SECTION_MERGE;
607 return get_section (name, flags, NULL);
609 return readonly_data_section;
612 /* Given NAME, a putative register name, discard any customary prefixes. */
614 static const char *
615 strip_reg_name (const char *name)
617 #ifdef REGISTER_PREFIX
618 if (!strncmp (name, REGISTER_PREFIX, strlen (REGISTER_PREFIX)))
619 name += strlen (REGISTER_PREFIX);
620 #endif
621 if (name[0] == '%' || name[0] == '#')
622 name++;
623 return name;
626 /* The user has asked for a DECL to have a particular name. Set (or
627 change) it in such a way that we don't prefix an underscore to
628 it. */
629 void
630 set_user_assembler_name (tree decl, const char *name)
632 char *starred = alloca (strlen (name) + 2);
633 starred[0] = '*';
634 strcpy (starred + 1, name);
635 change_decl_assembler_name (decl, get_identifier (starred));
636 SET_DECL_RTL (decl, NULL_RTX);
639 /* Decode an `asm' spec for a declaration as a register name.
640 Return the register number, or -1 if nothing specified,
641 or -2 if the ASMSPEC is not `cc' or `memory' and is not recognized,
642 or -3 if ASMSPEC is `cc' and is not recognized,
643 or -4 if ASMSPEC is `memory' and is not recognized.
644 Accept an exact spelling or a decimal number.
645 Prefixes such as % are optional. */
648 decode_reg_name (const char *asmspec)
650 if (asmspec != 0)
652 int i;
654 /* Get rid of confusing prefixes. */
655 asmspec = strip_reg_name (asmspec);
657 /* Allow a decimal number as a "register name". */
658 for (i = strlen (asmspec) - 1; i >= 0; i--)
659 if (! ISDIGIT (asmspec[i]))
660 break;
661 if (asmspec[0] != 0 && i < 0)
663 i = atoi (asmspec);
664 if (i < FIRST_PSEUDO_REGISTER && i >= 0)
665 return i;
666 else
667 return -2;
670 for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
671 if (reg_names[i][0]
672 && ! strcmp (asmspec, strip_reg_name (reg_names[i])))
673 return i;
675 #ifdef ADDITIONAL_REGISTER_NAMES
677 static const struct { const char *const name; const int number; } table[]
678 = ADDITIONAL_REGISTER_NAMES;
680 for (i = 0; i < (int) ARRAY_SIZE (table); i++)
681 if (table[i].name[0]
682 && ! strcmp (asmspec, table[i].name))
683 return table[i].number;
685 #endif /* ADDITIONAL_REGISTER_NAMES */
687 if (!strcmp (asmspec, "memory"))
688 return -4;
690 if (!strcmp (asmspec, "cc"))
691 return -3;
693 return -2;
696 return -1;
699 /* Create the DECL_RTL for a VAR_DECL or FUNCTION_DECL. DECL should
700 have static storage duration. In other words, it should not be an
701 automatic variable, including PARM_DECLs.
703 There is, however, one exception: this function handles variables
704 explicitly placed in a particular register by the user.
706 This is never called for PARM_DECL nodes. */
708 void
709 make_decl_rtl (tree decl)
711 const char *name = 0;
712 int reg_number;
713 rtx x;
715 /* Check that we are not being given an automatic variable. */
716 gcc_assert (TREE_CODE (decl) != PARM_DECL
717 && TREE_CODE (decl) != RESULT_DECL);
719 /* A weak alias has TREE_PUBLIC set but not the other bits. */
720 gcc_assert (TREE_CODE (decl) != VAR_DECL
721 || TREE_STATIC (decl)
722 || TREE_PUBLIC (decl)
723 || DECL_EXTERNAL (decl)
724 || DECL_REGISTER (decl));
726 /* And that we were not given a type or a label. */
727 gcc_assert (TREE_CODE (decl) != TYPE_DECL
728 && TREE_CODE (decl) != LABEL_DECL);
730 /* For a duplicate declaration, we can be called twice on the
731 same DECL node. Don't discard the RTL already made. */
732 if (DECL_RTL_SET_P (decl))
734 /* If the old RTL had the wrong mode, fix the mode. */
735 if (GET_MODE (DECL_RTL (decl)) != DECL_MODE (decl))
736 SET_DECL_RTL (decl, adjust_address_nv (DECL_RTL (decl),
737 DECL_MODE (decl), 0));
739 if (TREE_CODE (decl) != FUNCTION_DECL && DECL_REGISTER (decl))
740 return;
742 /* ??? Another way to do this would be to maintain a hashed
743 table of such critters. Instead of adding stuff to a DECL
744 to give certain attributes to it, we could use an external
745 hash map from DECL to set of attributes. */
747 /* Let the target reassign the RTL if it wants.
748 This is necessary, for example, when one machine specific
749 decl attribute overrides another. */
750 targetm.encode_section_info (decl, DECL_RTL (decl), false);
752 /* Make this function static known to the mudflap runtime. */
753 if (flag_mudflap && TREE_CODE (decl) == VAR_DECL)
754 mudflap_enqueue_decl (decl);
756 return;
759 name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
761 if (name[0] != '*' && TREE_CODE (decl) != FUNCTION_DECL
762 && DECL_REGISTER (decl))
764 error ("register name not specified for %q+D", decl);
766 else if (TREE_CODE (decl) != FUNCTION_DECL && DECL_REGISTER (decl))
768 const char *asmspec = name+1;
769 reg_number = decode_reg_name (asmspec);
770 /* First detect errors in declaring global registers. */
771 if (reg_number == -1)
772 error ("register name not specified for %q+D", decl);
773 else if (reg_number < 0)
774 error ("invalid register name for %q+D", decl);
775 else if (TYPE_MODE (TREE_TYPE (decl)) == BLKmode)
776 error ("data type of %q+D isn%'t suitable for a register",
777 decl);
778 else if (! HARD_REGNO_MODE_OK (reg_number, TYPE_MODE (TREE_TYPE (decl))))
779 error ("register specified for %q+D isn%'t suitable for data type",
780 decl);
781 /* Now handle properly declared static register variables. */
782 else
784 int nregs;
786 if (DECL_INITIAL (decl) != 0 && TREE_STATIC (decl))
788 DECL_INITIAL (decl) = 0;
789 error ("global register variable has initial value");
791 if (TREE_THIS_VOLATILE (decl))
792 warning (OPT_Wvolatile_register_var,
793 "optimization may eliminate reads and/or "
794 "writes to register variables");
796 /* If the user specified one of the eliminables registers here,
797 e.g., FRAME_POINTER_REGNUM, we don't want to get this variable
798 confused with that register and be eliminated. This usage is
799 somewhat suspect... */
801 SET_DECL_RTL (decl, gen_rtx_raw_REG (DECL_MODE (decl), reg_number));
802 ORIGINAL_REGNO (DECL_RTL (decl)) = reg_number;
803 REG_USERVAR_P (DECL_RTL (decl)) = 1;
805 if (TREE_STATIC (decl))
807 /* Make this register global, so not usable for anything
808 else. */
809 #ifdef ASM_DECLARE_REGISTER_GLOBAL
810 name = IDENTIFIER_POINTER (DECL_NAME (decl));
811 ASM_DECLARE_REGISTER_GLOBAL (asm_out_file, decl, reg_number, name);
812 #endif
813 nregs = hard_regno_nregs[reg_number][DECL_MODE (decl)];
814 while (nregs > 0)
815 globalize_reg (reg_number + --nregs);
818 /* As a register variable, it has no section. */
819 return;
822 /* Now handle ordinary static variables and functions (in memory).
823 Also handle vars declared register invalidly. */
824 else if (name[0] == '*')
826 #ifdef REGISTER_PREFIX
827 if (strlen (REGISTER_PREFIX) != 0)
829 reg_number = decode_reg_name (name);
830 if (reg_number >= 0 || reg_number == -3)
831 error ("register name given for non-register variable %q+D", decl);
833 #endif
836 /* Specifying a section attribute on a variable forces it into a
837 non-.bss section, and thus it cannot be common. */
838 if (TREE_CODE (decl) == VAR_DECL
839 && DECL_SECTION_NAME (decl) != NULL_TREE
840 && DECL_INITIAL (decl) == NULL_TREE
841 && DECL_COMMON (decl))
842 DECL_COMMON (decl) = 0;
844 /* Variables can't be both common and weak. */
845 if (TREE_CODE (decl) == VAR_DECL && DECL_WEAK (decl))
846 DECL_COMMON (decl) = 0;
848 x = gen_rtx_SYMBOL_REF (Pmode, name);
849 SYMBOL_REF_WEAK (x) = DECL_WEAK (decl);
850 SYMBOL_REF_DECL (x) = decl;
852 x = gen_rtx_MEM (DECL_MODE (decl), x);
853 if (TREE_CODE (decl) != FUNCTION_DECL)
854 set_mem_attributes (x, decl, 1);
855 SET_DECL_RTL (decl, x);
857 /* Optionally set flags or add text to the name to record information
858 such as that it is a function name.
859 If the name is changed, the macro ASM_OUTPUT_LABELREF
860 will have to know how to strip this information. */
861 targetm.encode_section_info (decl, DECL_RTL (decl), true);
863 /* Make this function static known to the mudflap runtime. */
864 if (flag_mudflap && TREE_CODE (decl) == VAR_DECL)
865 mudflap_enqueue_decl (decl);
868 /* Make the rtl for variable VAR be volatile.
869 Use this only for static variables. */
871 void
872 make_var_volatile (tree var)
874 gcc_assert (MEM_P (DECL_RTL (var)));
876 MEM_VOLATILE_P (DECL_RTL (var)) = 1;
879 /* Output a string of literal assembler code
880 for an `asm' keyword used between functions. */
882 void
883 assemble_asm (tree string)
885 app_enable ();
887 if (TREE_CODE (string) == ADDR_EXPR)
888 string = TREE_OPERAND (string, 0);
890 fprintf (asm_out_file, "\t%s\n", TREE_STRING_POINTER (string));
893 /* Record an element in the table of global destructors. SYMBOL is
894 a SYMBOL_REF of the function to be called; PRIORITY is a number
895 between 0 and MAX_INIT_PRIORITY. */
897 void
898 default_stabs_asm_out_destructor (rtx symbol ATTRIBUTE_UNUSED,
899 int priority ATTRIBUTE_UNUSED)
901 #if defined DBX_DEBUGGING_INFO || defined XCOFF_DEBUGGING_INFO
902 /* Tell GNU LD that this is part of the static destructor set.
903 This will work for any system that uses stabs, most usefully
904 aout systems. */
905 dbxout_begin_simple_stabs ("___DTOR_LIST__", 22 /* N_SETT */);
906 dbxout_stab_value_label (XSTR (symbol, 0));
907 #else
908 sorry ("global destructors not supported on this target");
909 #endif
912 void
913 default_named_section_asm_out_destructor (rtx symbol, int priority)
915 const char *section = ".dtors";
916 char buf[16];
918 /* ??? This only works reliably with the GNU linker. */
919 if (priority != DEFAULT_INIT_PRIORITY)
921 sprintf (buf, ".dtors.%.5u",
922 /* Invert the numbering so the linker puts us in the proper
923 order; constructors are run from right to left, and the
924 linker sorts in increasing order. */
925 MAX_INIT_PRIORITY - priority);
926 section = buf;
929 switch_to_section (get_section (section, SECTION_WRITE, NULL));
930 assemble_align (POINTER_SIZE);
931 assemble_integer (symbol, POINTER_SIZE / BITS_PER_UNIT, POINTER_SIZE, 1);
934 #ifdef DTORS_SECTION_ASM_OP
935 void
936 default_dtor_section_asm_out_destructor (rtx symbol,
937 int priority ATTRIBUTE_UNUSED)
939 switch_to_section (dtors_section);
940 assemble_align (POINTER_SIZE);
941 assemble_integer (symbol, POINTER_SIZE / BITS_PER_UNIT, POINTER_SIZE, 1);
943 #endif
945 /* Likewise for global constructors. */
947 void
948 default_stabs_asm_out_constructor (rtx symbol ATTRIBUTE_UNUSED,
949 int priority ATTRIBUTE_UNUSED)
951 #if defined DBX_DEBUGGING_INFO || defined XCOFF_DEBUGGING_INFO
952 /* Tell GNU LD that this is part of the static destructor set.
953 This will work for any system that uses stabs, most usefully
954 aout systems. */
955 dbxout_begin_simple_stabs ("___CTOR_LIST__", 22 /* N_SETT */);
956 dbxout_stab_value_label (XSTR (symbol, 0));
957 #else
958 sorry ("global constructors not supported on this target");
959 #endif
962 void
963 default_named_section_asm_out_constructor (rtx symbol, int priority)
965 const char *section = ".ctors";
966 char buf[16];
968 /* ??? This only works reliably with the GNU linker. */
969 if (priority != DEFAULT_INIT_PRIORITY)
971 sprintf (buf, ".ctors.%.5u",
972 /* Invert the numbering so the linker puts us in the proper
973 order; constructors are run from right to left, and the
974 linker sorts in increasing order. */
975 MAX_INIT_PRIORITY - priority);
976 section = buf;
979 switch_to_section (get_section (section, SECTION_WRITE, NULL));
980 assemble_align (POINTER_SIZE);
981 assemble_integer (symbol, POINTER_SIZE / BITS_PER_UNIT, POINTER_SIZE, 1);
984 #ifdef CTORS_SECTION_ASM_OP
985 void
986 default_ctor_section_asm_out_constructor (rtx symbol,
987 int priority ATTRIBUTE_UNUSED)
989 switch_to_section (ctors_section);
990 assemble_align (POINTER_SIZE);
991 assemble_integer (symbol, POINTER_SIZE / BITS_PER_UNIT, POINTER_SIZE, 1);
993 #endif
995 /* CONSTANT_POOL_BEFORE_FUNCTION may be defined as an expression with
996 a nonzero value if the constant pool should be output before the
997 start of the function, or a zero value if the pool should output
998 after the end of the function. The default is to put it before the
999 start. */
1001 #ifndef CONSTANT_POOL_BEFORE_FUNCTION
1002 #define CONSTANT_POOL_BEFORE_FUNCTION 1
1003 #endif
1005 /* DECL is an object (either VAR_DECL or FUNCTION_DECL) which is going
1006 to be output to assembler.
1007 Set first_global_object_name and weak_global_object_name as appropriate. */
1009 void
1010 notice_global_symbol (tree decl)
1012 const char **type = &first_global_object_name;
1014 if (first_global_object_name
1015 || !TREE_PUBLIC (decl) || DECL_EXTERNAL (decl)
1016 || !DECL_NAME (decl)
1017 || (TREE_CODE (decl) != FUNCTION_DECL
1018 && (TREE_CODE (decl) != VAR_DECL
1019 || (DECL_COMMON (decl)
1020 && (DECL_INITIAL (decl) == 0
1021 || DECL_INITIAL (decl) == error_mark_node))))
1022 || !MEM_P (DECL_RTL (decl)))
1023 return;
1025 /* We win when global object is found, but it is useful to know about weak
1026 symbol as well so we can produce nicer unique names. */
1027 if (DECL_WEAK (decl) || DECL_ONE_ONLY (decl))
1028 type = &weak_global_object_name;
1030 if (!*type)
1032 const char *p;
1033 const char *name;
1034 rtx decl_rtl = DECL_RTL (decl);
1036 p = targetm.strip_name_encoding (XSTR (XEXP (decl_rtl, 0), 0));
1037 name = ggc_strdup (p);
1039 *type = name;
1043 /* Output assembler code for the constant pool of a function and associated
1044 with defining the name of the function. DECL describes the function.
1045 NAME is the function's name. For the constant pool, we use the current
1046 constant pool data. */
1048 void
1049 assemble_start_function (tree decl, const char *fnname)
1051 int align;
1052 char tmp_label[100];
1053 bool hot_label_written = false;
1055 cfun->unlikely_text_section_name = NULL;
1057 first_function_block_is_cold = false;
1058 if (flag_reorder_blocks_and_partition)
1060 ASM_GENERATE_INTERNAL_LABEL (tmp_label, "LHOTB", const_labelno);
1061 cfun->hot_section_label = ggc_strdup (tmp_label);
1062 ASM_GENERATE_INTERNAL_LABEL (tmp_label, "LCOLDB", const_labelno);
1063 cfun->cold_section_label = ggc_strdup (tmp_label);
1064 ASM_GENERATE_INTERNAL_LABEL (tmp_label, "LHOTE", const_labelno);
1065 cfun->hot_section_end_label = ggc_strdup (tmp_label);
1066 ASM_GENERATE_INTERNAL_LABEL (tmp_label, "LCOLDE", const_labelno);
1067 cfun->cold_section_end_label = ggc_strdup (tmp_label);
1068 const_labelno++;
1070 else
1072 cfun->hot_section_label = NULL;
1073 cfun->cold_section_label = NULL;
1074 cfun->hot_section_end_label = NULL;
1075 cfun->cold_section_end_label = NULL;
1078 /* The following code does not need preprocessing in the assembler. */
1080 app_disable ();
1082 if (CONSTANT_POOL_BEFORE_FUNCTION)
1083 output_constant_pool (fnname, decl);
1085 resolve_unique_section (decl, 0, flag_function_sections);
1087 /* Make sure the not and cold text (code) sections are properly
1088 aligned. This is necessary here in the case where the function
1089 has both hot and cold sections, because we don't want to re-set
1090 the alignment when the section switch happens mid-function. */
1092 if (flag_reorder_blocks_and_partition)
1094 switch_to_section (unlikely_text_section ());
1095 assemble_align (FUNCTION_BOUNDARY);
1096 ASM_OUTPUT_LABEL (asm_out_file, cfun->cold_section_label);
1098 /* When the function starts with a cold section, we need to explicitly
1099 align the hot section and write out the hot section label.
1100 But if the current function is a thunk, we do not have a CFG. */
1101 if (!current_function_is_thunk
1102 && BB_PARTITION (ENTRY_BLOCK_PTR->next_bb) == BB_COLD_PARTITION)
1104 switch_to_section (text_section);
1105 assemble_align (FUNCTION_BOUNDARY);
1106 ASM_OUTPUT_LABEL (asm_out_file, cfun->hot_section_label);
1107 hot_label_written = true;
1108 first_function_block_is_cold = true;
1111 else if (DECL_SECTION_NAME (decl))
1113 /* Calls to function_section rely on first_function_block_is_cold
1114 being accurate. The first block may be cold even if we aren't
1115 doing partitioning, if the entire function was decided by
1116 choose_function_section (predict.c) to be cold. */
1118 initialize_cold_section_name ();
1120 if (cfun->unlikely_text_section_name
1121 && strcmp (TREE_STRING_POINTER (DECL_SECTION_NAME (decl)),
1122 cfun->unlikely_text_section_name) == 0)
1123 first_function_block_is_cold = true;
1126 in_cold_section_p = first_function_block_is_cold;
1128 /* Switch to the correct text section for the start of the function. */
1130 switch_to_section (function_section (decl));
1131 if (flag_reorder_blocks_and_partition
1132 && !hot_label_written)
1133 ASM_OUTPUT_LABEL (asm_out_file, cfun->hot_section_label);
1135 /* Tell assembler to move to target machine's alignment for functions. */
1136 align = floor_log2 (FUNCTION_BOUNDARY / BITS_PER_UNIT);
1137 if (align < force_align_functions_log)
1138 align = force_align_functions_log;
1139 if (align > 0)
1141 ASM_OUTPUT_ALIGN (asm_out_file, align);
1144 /* Handle a user-specified function alignment.
1145 Note that we still need to align to FUNCTION_BOUNDARY, as above,
1146 because ASM_OUTPUT_MAX_SKIP_ALIGN might not do any alignment at all. */
1147 if (align_functions_log > align
1148 && cfun->function_frequency != FUNCTION_FREQUENCY_UNLIKELY_EXECUTED)
1150 #ifdef ASM_OUTPUT_MAX_SKIP_ALIGN
1151 ASM_OUTPUT_MAX_SKIP_ALIGN (asm_out_file,
1152 align_functions_log, align_functions - 1);
1153 #else
1154 ASM_OUTPUT_ALIGN (asm_out_file, align_functions_log);
1155 #endif
1158 #ifdef ASM_OUTPUT_FUNCTION_PREFIX
1159 ASM_OUTPUT_FUNCTION_PREFIX (asm_out_file, fnname);
1160 #endif
1162 (*debug_hooks->begin_function) (decl);
1164 /* Make function name accessible from other files, if appropriate. */
1166 if (TREE_PUBLIC (decl))
1168 notice_global_symbol (decl);
1170 globalize_decl (decl);
1172 maybe_assemble_visibility (decl);
1175 if (DECL_PRESERVE_P (decl))
1176 targetm.asm_out.mark_decl_preserved (fnname);
1178 /* Do any machine/system dependent processing of the function name. */
1179 #ifdef ASM_DECLARE_FUNCTION_NAME
1180 ASM_DECLARE_FUNCTION_NAME (asm_out_file, fnname, current_function_decl);
1181 #else
1182 /* Standard thing is just output label for the function. */
1183 ASM_OUTPUT_LABEL (asm_out_file, fnname);
1184 #endif /* ASM_DECLARE_FUNCTION_NAME */
1187 /* Output assembler code associated with defining the size of the
1188 function. DECL describes the function. NAME is the function's name. */
1190 void
1191 assemble_end_function (tree decl, const char *fnname)
1193 #ifdef ASM_DECLARE_FUNCTION_SIZE
1194 /* We could have switched section in the middle of the function. */
1195 if (flag_reorder_blocks_and_partition)
1196 switch_to_section (function_section (decl));
1197 ASM_DECLARE_FUNCTION_SIZE (asm_out_file, fnname, decl);
1198 #endif
1199 if (! CONSTANT_POOL_BEFORE_FUNCTION)
1201 output_constant_pool (fnname, decl);
1202 switch_to_section (function_section (decl)); /* need to switch back */
1204 /* Output labels for end of hot/cold text sections (to be used by
1205 debug info.) */
1206 if (flag_reorder_blocks_and_partition)
1208 section *save_text_section;
1210 save_text_section = in_section;
1211 switch_to_section (unlikely_text_section ());
1212 ASM_OUTPUT_LABEL (asm_out_file, cfun->cold_section_end_label);
1213 if (first_function_block_is_cold)
1214 switch_to_section (text_section);
1215 else
1216 switch_to_section (function_section (decl));
1217 ASM_OUTPUT_LABEL (asm_out_file, cfun->hot_section_end_label);
1218 switch_to_section (save_text_section);
1222 /* Assemble code to leave SIZE bytes of zeros. */
1224 void
1225 assemble_zeros (unsigned HOST_WIDE_INT size)
1227 /* Do no output if -fsyntax-only. */
1228 if (flag_syntax_only)
1229 return;
1231 #ifdef ASM_NO_SKIP_IN_TEXT
1232 /* The `space' pseudo in the text section outputs nop insns rather than 0s,
1233 so we must output 0s explicitly in the text section. */
1234 if (ASM_NO_SKIP_IN_TEXT && (in_section->common.flags & SECTION_CODE) != 0)
1236 unsigned HOST_WIDE_INT i;
1237 for (i = 0; i < size; i++)
1238 assemble_integer (const0_rtx, 1, BITS_PER_UNIT, 1);
1240 else
1241 #endif
1242 if (size > 0)
1243 ASM_OUTPUT_SKIP (asm_out_file, size);
1246 /* Assemble an alignment pseudo op for an ALIGN-bit boundary. */
1248 void
1249 assemble_align (int align)
1251 if (align > BITS_PER_UNIT)
1253 ASM_OUTPUT_ALIGN (asm_out_file, floor_log2 (align / BITS_PER_UNIT));
1257 /* Assemble a string constant with the specified C string as contents. */
1259 void
1260 assemble_string (const char *p, int size)
1262 int pos = 0;
1263 int maximum = 2000;
1265 /* If the string is very long, split it up. */
1267 while (pos < size)
1269 int thissize = size - pos;
1270 if (thissize > maximum)
1271 thissize = maximum;
1273 ASM_OUTPUT_ASCII (asm_out_file, p, thissize);
1275 pos += thissize;
1276 p += thissize;
1281 #if defined ASM_OUTPUT_ALIGNED_DECL_LOCAL
1282 #define ASM_EMIT_LOCAL(decl, name, size, rounded) \
1283 ASM_OUTPUT_ALIGNED_DECL_LOCAL (asm_out_file, decl, name, size, DECL_ALIGN (decl))
1284 #else
1285 #if defined ASM_OUTPUT_ALIGNED_LOCAL
1286 #define ASM_EMIT_LOCAL(decl, name, size, rounded) \
1287 ASM_OUTPUT_ALIGNED_LOCAL (asm_out_file, name, size, DECL_ALIGN (decl))
1288 #else
1289 #define ASM_EMIT_LOCAL(decl, name, size, rounded) \
1290 ASM_OUTPUT_LOCAL (asm_out_file, name, size, rounded)
1291 #endif
1292 #endif
1294 #if defined ASM_OUTPUT_ALIGNED_BSS
1295 #define ASM_EMIT_BSS(decl, name, size, rounded) \
1296 ASM_OUTPUT_ALIGNED_BSS (asm_out_file, decl, name, size, DECL_ALIGN (decl))
1297 #else
1298 #if defined ASM_OUTPUT_BSS
1299 #define ASM_EMIT_BSS(decl, name, size, rounded) \
1300 ASM_OUTPUT_BSS (asm_out_file, decl, name, size, rounded)
1301 #else
1302 #undef ASM_EMIT_BSS
1303 #endif
1304 #endif
1306 #if defined ASM_OUTPUT_ALIGNED_DECL_COMMON
1307 #define ASM_EMIT_COMMON(decl, name, size, rounded) \
1308 ASM_OUTPUT_ALIGNED_DECL_COMMON (asm_out_file, decl, name, size, DECL_ALIGN (decl))
1309 #else
1310 #if defined ASM_OUTPUT_ALIGNED_COMMON
1311 #define ASM_EMIT_COMMON(decl, name, size, rounded) \
1312 ASM_OUTPUT_ALIGNED_COMMON (asm_out_file, name, size, DECL_ALIGN (decl))
1313 #else
1314 #define ASM_EMIT_COMMON(decl, name, size, rounded) \
1315 ASM_OUTPUT_COMMON (asm_out_file, name, size, rounded)
1316 #endif
1317 #endif
1319 static bool
1320 asm_emit_uninitialised (tree decl, const char *name,
1321 unsigned HOST_WIDE_INT size ATTRIBUTE_UNUSED,
1322 unsigned HOST_WIDE_INT rounded ATTRIBUTE_UNUSED)
1324 enum
1326 asm_dest_common,
1327 asm_dest_bss,
1328 asm_dest_local
1330 destination = asm_dest_local;
1332 /* ??? We should handle .bss via select_section mechanisms rather than
1333 via special target hooks. That would eliminate this special case. */
1334 if (TREE_PUBLIC (decl))
1336 if (!DECL_COMMON (decl))
1337 #ifdef ASM_EMIT_BSS
1338 destination = asm_dest_bss;
1339 #else
1340 return false;
1341 #endif
1342 else
1343 destination = asm_dest_common;
1346 if (destination != asm_dest_common)
1348 resolve_unique_section (decl, 0, flag_data_sections);
1349 /* Custom sections don't belong here. */
1350 if (DECL_SECTION_NAME (decl))
1351 return false;
1354 if (destination == asm_dest_bss)
1355 globalize_decl (decl);
1357 if (flag_shared_data)
1359 switch (destination)
1361 #ifdef ASM_OUTPUT_SHARED_BSS
1362 case asm_dest_bss:
1363 ASM_OUTPUT_SHARED_BSS (asm_out_file, decl, name, size, rounded);
1364 return;
1365 #endif
1366 #ifdef ASM_OUTPUT_SHARED_COMMON
1367 case asm_dest_common:
1368 ASM_OUTPUT_SHARED_COMMON (asm_out_file, name, size, rounded);
1369 return;
1370 #endif
1371 #ifdef ASM_OUTPUT_SHARED_LOCAL
1372 case asm_dest_local:
1373 ASM_OUTPUT_SHARED_LOCAL (asm_out_file, name, size, rounded);
1374 return;
1375 #endif
1376 default:
1377 break;
1381 switch (destination)
1383 #ifdef ASM_EMIT_BSS
1384 case asm_dest_bss:
1385 ASM_EMIT_BSS (decl, name, size, rounded);
1386 break;
1387 #endif
1388 case asm_dest_common:
1389 ASM_EMIT_COMMON (decl, name, size, rounded);
1390 break;
1391 case asm_dest_local:
1392 ASM_EMIT_LOCAL (decl, name, size, rounded);
1393 break;
1394 default:
1395 gcc_unreachable ();
1398 return true;
1401 /* Assemble everything that is needed for a variable or function declaration.
1402 Not used for automatic variables, and not used for function definitions.
1403 Should not be called for variables of incomplete structure type.
1405 TOP_LEVEL is nonzero if this variable has file scope.
1406 AT_END is nonzero if this is the special handling, at end of compilation,
1407 to define things that have had only tentative definitions.
1408 DONT_OUTPUT_DATA if nonzero means don't actually output the
1409 initial value (that will be done by the caller). */
1411 void
1412 assemble_variable (tree decl, int top_level ATTRIBUTE_UNUSED,
1413 int at_end ATTRIBUTE_UNUSED, int dont_output_data)
1415 const char *name;
1416 unsigned int align;
1417 int reloc = 0;
1418 rtx decl_rtl;
1420 if (lang_hooks.decls.prepare_assemble_variable)
1421 lang_hooks.decls.prepare_assemble_variable (decl);
1423 last_assemble_variable_decl = 0;
1425 /* Normally no need to say anything here for external references,
1426 since assemble_external is called by the language-specific code
1427 when a declaration is first seen. */
1429 if (DECL_EXTERNAL (decl))
1430 return;
1432 /* Output no assembler code for a function declaration.
1433 Only definitions of functions output anything. */
1435 if (TREE_CODE (decl) == FUNCTION_DECL)
1436 return;
1438 /* Do nothing for global register variables. */
1439 if (DECL_RTL_SET_P (decl) && REG_P (DECL_RTL (decl)))
1441 TREE_ASM_WRITTEN (decl) = 1;
1442 return;
1445 /* If type was incomplete when the variable was declared,
1446 see if it is complete now. */
1448 if (DECL_SIZE (decl) == 0)
1449 layout_decl (decl, 0);
1451 /* Still incomplete => don't allocate it; treat the tentative defn
1452 (which is what it must have been) as an `extern' reference. */
1454 if (!dont_output_data && DECL_SIZE (decl) == 0)
1456 error ("storage size of %q+D isn%'t known", decl);
1457 TREE_ASM_WRITTEN (decl) = 1;
1458 return;
1461 /* The first declaration of a variable that comes through this function
1462 decides whether it is global (in C, has external linkage)
1463 or local (in C, has internal linkage). So do nothing more
1464 if this function has already run. */
1466 if (TREE_ASM_WRITTEN (decl))
1467 return;
1469 /* Make sure targetm.encode_section_info is invoked before we set
1470 ASM_WRITTEN. */
1471 decl_rtl = DECL_RTL (decl);
1473 TREE_ASM_WRITTEN (decl) = 1;
1475 /* Do no output if -fsyntax-only. */
1476 if (flag_syntax_only)
1477 return;
1479 app_disable ();
1481 if (! dont_output_data
1482 && ! host_integerp (DECL_SIZE_UNIT (decl), 1))
1484 error ("size of variable %q+D is too large", decl);
1485 return;
1488 name = XSTR (XEXP (decl_rtl, 0), 0);
1489 if (TREE_PUBLIC (decl) && DECL_NAME (decl))
1490 notice_global_symbol (decl);
1492 /* Compute the alignment of this data. */
1494 align = DECL_ALIGN (decl);
1496 /* In the case for initialing an array whose length isn't specified,
1497 where we have not yet been able to do the layout,
1498 figure out the proper alignment now. */
1499 if (dont_output_data && DECL_SIZE (decl) == 0
1500 && TREE_CODE (TREE_TYPE (decl)) == ARRAY_TYPE)
1501 align = MAX (align, TYPE_ALIGN (TREE_TYPE (TREE_TYPE (decl))));
1503 /* Some object file formats have a maximum alignment which they support.
1504 In particular, a.out format supports a maximum alignment of 4. */
1505 if (align > MAX_OFILE_ALIGNMENT)
1507 warning (0, "alignment of %q+D is greater than maximum object "
1508 "file alignment. Using %d", decl,
1509 MAX_OFILE_ALIGNMENT/BITS_PER_UNIT);
1510 align = MAX_OFILE_ALIGNMENT;
1513 /* On some machines, it is good to increase alignment sometimes. */
1514 if (! DECL_USER_ALIGN (decl))
1516 #ifdef DATA_ALIGNMENT
1517 align = DATA_ALIGNMENT (TREE_TYPE (decl), align);
1518 #endif
1519 #ifdef CONSTANT_ALIGNMENT
1520 if (DECL_INITIAL (decl) != 0 && DECL_INITIAL (decl) != error_mark_node)
1521 align = CONSTANT_ALIGNMENT (DECL_INITIAL (decl), align);
1522 #endif
1525 /* Reset the alignment in case we have made it tighter, so we can benefit
1526 from it in get_pointer_alignment. */
1527 DECL_ALIGN (decl) = align;
1528 set_mem_align (decl_rtl, align);
1530 if (TREE_PUBLIC (decl))
1531 maybe_assemble_visibility (decl);
1533 if (DECL_PRESERVE_P (decl))
1534 targetm.asm_out.mark_decl_preserved (name);
1536 /* Handle uninitialized definitions. */
1538 /* If the decl has been given an explicit section name, then it
1539 isn't common, and shouldn't be handled as such. */
1540 if (DECL_SECTION_NAME (decl) || dont_output_data)
1542 /* We don't implement common thread-local data at present. */
1543 else if (DECL_THREAD_LOCAL_P (decl))
1545 if (DECL_COMMON (decl))
1546 sorry ("thread-local COMMON data not implemented");
1548 else if (DECL_INITIAL (decl) == 0
1549 || DECL_INITIAL (decl) == error_mark_node
1550 || (flag_zero_initialized_in_bss
1551 /* Leave constant zeroes in .rodata so they can be shared. */
1552 && !TREE_READONLY (decl)
1553 && initializer_zerop (DECL_INITIAL (decl))))
1555 unsigned HOST_WIDE_INT size = tree_low_cst (DECL_SIZE_UNIT (decl), 1);
1556 unsigned HOST_WIDE_INT rounded = size;
1558 /* Don't allocate zero bytes of common,
1559 since that means "undefined external" in the linker. */
1560 if (size == 0)
1561 rounded = 1;
1563 /* Round size up to multiple of BIGGEST_ALIGNMENT bits
1564 so that each uninitialized object starts on such a boundary. */
1565 rounded += (BIGGEST_ALIGNMENT / BITS_PER_UNIT) - 1;
1566 rounded = (rounded / (BIGGEST_ALIGNMENT / BITS_PER_UNIT)
1567 * (BIGGEST_ALIGNMENT / BITS_PER_UNIT));
1569 #if !defined(ASM_OUTPUT_ALIGNED_COMMON) && !defined(ASM_OUTPUT_ALIGNED_DECL_COMMON) && !defined(ASM_OUTPUT_ALIGNED_BSS)
1570 if ((unsigned HOST_WIDE_INT) DECL_ALIGN_UNIT (decl) > rounded)
1571 warning (0, "requested alignment for %q+D is greater than "
1572 "implemented alignment of %wu", decl, rounded);
1573 #endif
1575 /* If the target cannot output uninitialized but not common global data
1576 in .bss, then we have to use .data, so fall through. */
1577 if (asm_emit_uninitialised (decl, name, size, rounded))
1578 return;
1581 /* Handle initialized definitions.
1582 Also handle uninitialized global definitions if -fno-common and the
1583 target doesn't support ASM_OUTPUT_BSS. */
1585 /* First make the assembler name(s) global if appropriate. */
1586 if (TREE_PUBLIC (decl) && DECL_NAME (decl))
1587 globalize_decl (decl);
1589 /* Output any data that we will need to use the address of. */
1590 if (DECL_INITIAL (decl) == error_mark_node)
1591 reloc = contains_pointers_p (TREE_TYPE (decl)) ? 3 : 0;
1592 else if (DECL_INITIAL (decl))
1594 reloc = compute_reloc_for_constant (DECL_INITIAL (decl));
1595 output_addressed_constants (DECL_INITIAL (decl));
1598 /* Switch to the appropriate section. */
1599 resolve_unique_section (decl, reloc, flag_data_sections);
1600 variable_section (decl, reloc);
1602 /* dbxout.c needs to know this. */
1603 if (in_section && (in_section->common.flags & SECTION_CODE) != 0)
1604 DECL_IN_TEXT_SECTION (decl) = 1;
1606 /* Output the alignment of this data. */
1607 if (align > BITS_PER_UNIT)
1608 ASM_OUTPUT_ALIGN (asm_out_file, floor_log2 (DECL_ALIGN_UNIT (decl)));
1610 /* Do any machine/system dependent processing of the object. */
1611 #ifdef ASM_DECLARE_OBJECT_NAME
1612 last_assemble_variable_decl = decl;
1613 ASM_DECLARE_OBJECT_NAME (asm_out_file, name, decl);
1614 #else
1615 /* Standard thing is just output label for the object. */
1616 ASM_OUTPUT_LABEL (asm_out_file, name);
1617 #endif /* ASM_DECLARE_OBJECT_NAME */
1619 if (!dont_output_data)
1621 if (DECL_INITIAL (decl)
1622 && DECL_INITIAL (decl) != error_mark_node
1623 && !initializer_zerop (DECL_INITIAL (decl)))
1624 /* Output the actual data. */
1625 output_constant (DECL_INITIAL (decl),
1626 tree_low_cst (DECL_SIZE_UNIT (decl), 1),
1627 align);
1628 else
1629 /* Leave space for it. */
1630 assemble_zeros (tree_low_cst (DECL_SIZE_UNIT (decl), 1));
1634 /* Return 1 if type TYPE contains any pointers. */
1636 static int
1637 contains_pointers_p (tree type)
1639 switch (TREE_CODE (type))
1641 case POINTER_TYPE:
1642 case REFERENCE_TYPE:
1643 /* I'm not sure whether OFFSET_TYPE needs this treatment,
1644 so I'll play safe and return 1. */
1645 case OFFSET_TYPE:
1646 return 1;
1648 case RECORD_TYPE:
1649 case UNION_TYPE:
1650 case QUAL_UNION_TYPE:
1652 tree fields;
1653 /* For a type that has fields, see if the fields have pointers. */
1654 for (fields = TYPE_FIELDS (type); fields; fields = TREE_CHAIN (fields))
1655 if (TREE_CODE (fields) == FIELD_DECL
1656 && contains_pointers_p (TREE_TYPE (fields)))
1657 return 1;
1658 return 0;
1661 case ARRAY_TYPE:
1662 /* An array type contains pointers if its element type does. */
1663 return contains_pointers_p (TREE_TYPE (type));
1665 default:
1666 return 0;
1670 /* In unit-at-a-time mode, we delay assemble_external processing until
1671 the compilation unit is finalized. This is the best we can do for
1672 right now (i.e. stage 3 of GCC 4.0) - the right thing is to delay
1673 it all the way to final. See PR 17982 for further discussion. */
1674 static GTY(()) tree pending_assemble_externals;
1676 #ifdef ASM_OUTPUT_EXTERNAL
1677 /* True if DECL is a function decl for which no out-of-line copy exists.
1678 It is assumed that DECL's assembler name has been set. */
1680 static bool
1681 incorporeal_function_p (tree decl)
1683 if (TREE_CODE (decl) == FUNCTION_DECL && DECL_BUILT_IN (decl))
1685 const char *name;
1687 if (DECL_BUILT_IN_CLASS (decl) == BUILT_IN_NORMAL
1688 && DECL_FUNCTION_CODE (decl) == BUILT_IN_ALLOCA)
1689 return true;
1691 name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
1692 if (strncmp (name, "__builtin_", strlen ("__builtin_")) == 0)
1693 return true;
1695 return false;
1698 /* Actually do the tests to determine if this is necessary, and invoke
1699 ASM_OUTPUT_EXTERNAL. */
1700 static void
1701 assemble_external_real (tree decl)
1703 rtx rtl = DECL_RTL (decl);
1705 if (MEM_P (rtl) && GET_CODE (XEXP (rtl, 0)) == SYMBOL_REF
1706 && !SYMBOL_REF_USED (XEXP (rtl, 0))
1707 && !incorporeal_function_p (decl))
1709 /* Some systems do require some output. */
1710 SYMBOL_REF_USED (XEXP (rtl, 0)) = 1;
1711 ASM_OUTPUT_EXTERNAL (asm_out_file, decl, XSTR (XEXP (rtl, 0), 0));
1714 #endif
1716 void
1717 process_pending_assemble_externals (void)
1719 #ifdef ASM_OUTPUT_EXTERNAL
1720 tree list;
1721 for (list = pending_assemble_externals; list; list = TREE_CHAIN (list))
1722 assemble_external_real (TREE_VALUE (list));
1724 pending_assemble_externals = 0;
1725 #endif
1728 /* Output something to declare an external symbol to the assembler.
1729 (Most assemblers don't need this, so we normally output nothing.)
1730 Do nothing if DECL is not external. */
1732 void
1733 assemble_external (tree decl ATTRIBUTE_UNUSED)
1735 /* Because most platforms do not define ASM_OUTPUT_EXTERNAL, the
1736 main body of this code is only rarely exercised. To provide some
1737 testing, on all platforms, we make sure that the ASM_OUT_FILE is
1738 open. If it's not, we should not be calling this function. */
1739 gcc_assert (asm_out_file);
1741 #ifdef ASM_OUTPUT_EXTERNAL
1742 if (!DECL_P (decl) || !DECL_EXTERNAL (decl) || !TREE_PUBLIC (decl))
1743 return;
1745 if (flag_unit_at_a_time)
1746 pending_assemble_externals = tree_cons (0, decl,
1747 pending_assemble_externals);
1748 else
1749 assemble_external_real (decl);
1750 #endif
1753 /* Similar, for calling a library function FUN. */
1755 void
1756 assemble_external_libcall (rtx fun)
1758 /* Declare library function name external when first used, if nec. */
1759 if (! SYMBOL_REF_USED (fun))
1761 SYMBOL_REF_USED (fun) = 1;
1762 targetm.asm_out.external_libcall (fun);
1766 /* Assemble a label named NAME. */
1768 void
1769 assemble_label (const char *name)
1771 ASM_OUTPUT_LABEL (asm_out_file, name);
1774 /* Set the symbol_referenced flag for ID. */
1775 void
1776 mark_referenced (tree id)
1778 TREE_SYMBOL_REFERENCED (id) = 1;
1781 /* Set the symbol_referenced flag for DECL and notify callgraph. */
1782 void
1783 mark_decl_referenced (tree decl)
1785 if (TREE_CODE (decl) == FUNCTION_DECL)
1787 /* Extern inline functions don't become needed when referenced.
1788 If we know a method will be emitted in other TU and no new
1789 functions can be marked reachable, just use the external
1790 definition. */
1791 struct cgraph_node *node = cgraph_node (decl);
1792 if (!DECL_EXTERNAL (decl)
1793 && (!node->local.vtable_method || !cgraph_global_info_ready
1794 || !node->local.finalized))
1795 cgraph_mark_needed_node (node);
1797 else if (TREE_CODE (decl) == VAR_DECL)
1799 struct cgraph_varpool_node *node = cgraph_varpool_node (decl);
1800 cgraph_varpool_mark_needed_node (node);
1801 /* C++ frontend use mark_decl_references to force COMDAT variables
1802 to be output that might appear dead otherwise. */
1803 node->force_output = true;
1805 /* else do nothing - we can get various sorts of CST nodes here,
1806 which do not need to be marked. */
1810 /* Follow the IDENTIFIER_TRANSPARENT_ALIAS chain starting at *ALIAS
1811 until we find an identifier that is not itself a transparent alias.
1812 Modify the alias passed to it by reference (and all aliases on the
1813 way to the ultimate target), such that they do not have to be
1814 followed again, and return the ultimate target of the alias
1815 chain. */
1817 static inline tree
1818 ultimate_transparent_alias_target (tree *alias)
1820 tree target = *alias;
1822 if (IDENTIFIER_TRANSPARENT_ALIAS (target))
1824 gcc_assert (TREE_CHAIN (target));
1825 target = ultimate_transparent_alias_target (&TREE_CHAIN (target));
1826 gcc_assert (! IDENTIFIER_TRANSPARENT_ALIAS (target)
1827 && ! TREE_CHAIN (target));
1828 *alias = target;
1831 return target;
1834 /* Output to FILE (an assembly file) a reference to NAME. If NAME
1835 starts with a *, the rest of NAME is output verbatim. Otherwise
1836 NAME is transformed in a target-specific way (usually by the
1837 addition of an underscore). */
1839 void
1840 assemble_name_raw (FILE *file, const char *name)
1842 if (name[0] == '*')
1843 fputs (&name[1], file);
1844 else
1845 ASM_OUTPUT_LABELREF (file, name);
1848 /* Like assemble_name_raw, but should be used when NAME might refer to
1849 an entity that is also represented as a tree (like a function or
1850 variable). If NAME does refer to such an entity, that entity will
1851 be marked as referenced. */
1853 void
1854 assemble_name (FILE *file, const char *name)
1856 const char *real_name;
1857 tree id;
1859 real_name = targetm.strip_name_encoding (name);
1861 id = maybe_get_identifier (real_name);
1862 if (id)
1864 tree id_orig = id;
1866 mark_referenced (id);
1867 ultimate_transparent_alias_target (&id);
1868 if (id != id_orig)
1869 name = IDENTIFIER_POINTER (id);
1870 gcc_assert (! TREE_CHAIN (id));
1873 assemble_name_raw (file, name);
1876 /* Allocate SIZE bytes writable static space with a gensym name
1877 and return an RTX to refer to its address. */
1880 assemble_static_space (unsigned HOST_WIDE_INT size)
1882 char name[12];
1883 const char *namestring;
1884 rtx x;
1886 #if 0
1887 if (flag_shared_data)
1888 switch_to_section (data_section);
1889 #endif
1891 ASM_GENERATE_INTERNAL_LABEL (name, "LF", const_labelno);
1892 ++const_labelno;
1893 namestring = ggc_strdup (name);
1895 x = gen_rtx_SYMBOL_REF (Pmode, namestring);
1896 SYMBOL_REF_FLAGS (x) = SYMBOL_FLAG_LOCAL;
1898 #ifdef ASM_OUTPUT_ALIGNED_DECL_LOCAL
1899 ASM_OUTPUT_ALIGNED_DECL_LOCAL (asm_out_file, NULL_TREE, name, size,
1900 BIGGEST_ALIGNMENT);
1901 #else
1902 #ifdef ASM_OUTPUT_ALIGNED_LOCAL
1903 ASM_OUTPUT_ALIGNED_LOCAL (asm_out_file, name, size, BIGGEST_ALIGNMENT);
1904 #else
1906 /* Round size up to multiple of BIGGEST_ALIGNMENT bits
1907 so that each uninitialized object starts on such a boundary. */
1908 /* Variable `rounded' might or might not be used in ASM_OUTPUT_LOCAL. */
1909 unsigned HOST_WIDE_INT rounded ATTRIBUTE_UNUSED
1910 = ((size + (BIGGEST_ALIGNMENT / BITS_PER_UNIT) - 1)
1911 / (BIGGEST_ALIGNMENT / BITS_PER_UNIT)
1912 * (BIGGEST_ALIGNMENT / BITS_PER_UNIT));
1913 ASM_OUTPUT_LOCAL (asm_out_file, name, size, rounded);
1915 #endif
1916 #endif
1917 return x;
1920 /* Assemble the static constant template for function entry trampolines.
1921 This is done at most once per compilation.
1922 Returns an RTX for the address of the template. */
1924 static GTY(()) rtx initial_trampoline;
1926 #ifdef TRAMPOLINE_TEMPLATE
1928 assemble_trampoline_template (void)
1930 char label[256];
1931 const char *name;
1932 int align;
1933 rtx symbol;
1935 if (initial_trampoline)
1936 return initial_trampoline;
1938 /* By default, put trampoline templates in read-only data section. */
1940 #ifdef TRAMPOLINE_SECTION
1941 switch_to_section (TRAMPOLINE_SECTION);
1942 #else
1943 switch_to_section (readonly_data_section);
1944 #endif
1946 /* Write the assembler code to define one. */
1947 align = floor_log2 (TRAMPOLINE_ALIGNMENT / BITS_PER_UNIT);
1948 if (align > 0)
1950 ASM_OUTPUT_ALIGN (asm_out_file, align);
1953 targetm.asm_out.internal_label (asm_out_file, "LTRAMP", 0);
1954 TRAMPOLINE_TEMPLATE (asm_out_file);
1956 /* Record the rtl to refer to it. */
1957 ASM_GENERATE_INTERNAL_LABEL (label, "LTRAMP", 0);
1958 name = ggc_strdup (label);
1959 symbol = gen_rtx_SYMBOL_REF (Pmode, name);
1960 SYMBOL_REF_FLAGS (symbol) = SYMBOL_FLAG_LOCAL;
1962 initial_trampoline = gen_rtx_MEM (BLKmode, symbol);
1963 set_mem_align (initial_trampoline, TRAMPOLINE_ALIGNMENT);
1965 return initial_trampoline;
1967 #endif
1969 /* A and B are either alignments or offsets. Return the minimum alignment
1970 that may be assumed after adding the two together. */
1972 static inline unsigned
1973 min_align (unsigned int a, unsigned int b)
1975 return (a | b) & -(a | b);
1978 /* Return the assembler directive for creating a given kind of integer
1979 object. SIZE is the number of bytes in the object and ALIGNED_P
1980 indicates whether it is known to be aligned. Return NULL if the
1981 assembly dialect has no such directive.
1983 The returned string should be printed at the start of a new line and
1984 be followed immediately by the object's initial value. */
1986 const char *
1987 integer_asm_op (int size, int aligned_p)
1989 struct asm_int_op *ops;
1991 if (aligned_p)
1992 ops = &targetm.asm_out.aligned_op;
1993 else
1994 ops = &targetm.asm_out.unaligned_op;
1996 switch (size)
1998 case 1:
1999 return targetm.asm_out.byte_op;
2000 case 2:
2001 return ops->hi;
2002 case 4:
2003 return ops->si;
2004 case 8:
2005 return ops->di;
2006 case 16:
2007 return ops->ti;
2008 default:
2009 return NULL;
2013 /* Use directive OP to assemble an integer object X. Print OP at the
2014 start of the line, followed immediately by the value of X. */
2016 void
2017 assemble_integer_with_op (const char *op, rtx x)
2019 fputs (op, asm_out_file);
2020 output_addr_const (asm_out_file, x);
2021 fputc ('\n', asm_out_file);
2024 /* The default implementation of the asm_out.integer target hook. */
2026 bool
2027 default_assemble_integer (rtx x ATTRIBUTE_UNUSED,
2028 unsigned int size ATTRIBUTE_UNUSED,
2029 int aligned_p ATTRIBUTE_UNUSED)
2031 const char *op = integer_asm_op (size, aligned_p);
2032 /* Avoid GAS bugs for large values. Specifically negative values whose
2033 absolute value fits in a bfd_vma, but not in a bfd_signed_vma. */
2034 if (size > UNITS_PER_WORD && size > POINTER_SIZE / BITS_PER_UNIT)
2035 return false;
2036 return op && (assemble_integer_with_op (op, x), true);
2039 /* Assemble the integer constant X into an object of SIZE bytes. ALIGN is
2040 the alignment of the integer in bits. Return 1 if we were able to output
2041 the constant, otherwise 0. We must be able to output the constant,
2042 if FORCE is nonzero. */
2044 bool
2045 assemble_integer (rtx x, unsigned int size, unsigned int align, int force)
2047 int aligned_p;
2049 aligned_p = (align >= MIN (size * BITS_PER_UNIT, BIGGEST_ALIGNMENT));
2051 /* See if the target hook can handle this kind of object. */
2052 if (targetm.asm_out.integer (x, size, aligned_p))
2053 return true;
2055 /* If the object is a multi-byte one, try splitting it up. Split
2056 it into words it if is multi-word, otherwise split it into bytes. */
2057 if (size > 1)
2059 enum machine_mode omode, imode;
2060 unsigned int subalign;
2061 unsigned int subsize, i;
2063 subsize = size > UNITS_PER_WORD? UNITS_PER_WORD : 1;
2064 subalign = MIN (align, subsize * BITS_PER_UNIT);
2065 omode = mode_for_size (subsize * BITS_PER_UNIT, MODE_INT, 0);
2066 imode = mode_for_size (size * BITS_PER_UNIT, MODE_INT, 0);
2068 for (i = 0; i < size; i += subsize)
2070 rtx partial = simplify_subreg (omode, x, imode, i);
2071 if (!partial || !assemble_integer (partial, subsize, subalign, 0))
2072 break;
2074 if (i == size)
2075 return true;
2077 /* If we've printed some of it, but not all of it, there's no going
2078 back now. */
2079 gcc_assert (!i);
2082 gcc_assert (!force);
2084 return false;
2087 void
2088 assemble_real (REAL_VALUE_TYPE d, enum machine_mode mode, unsigned int align)
2090 long data[4];
2091 int i;
2092 int bitsize, nelts, nunits, units_per;
2094 /* This is hairy. We have a quantity of known size. real_to_target
2095 will put it into an array of *host* longs, 32 bits per element
2096 (even if long is more than 32 bits). We need to determine the
2097 number of array elements that are occupied (nelts) and the number
2098 of *target* min-addressable units that will be occupied in the
2099 object file (nunits). We cannot assume that 32 divides the
2100 mode's bitsize (size * BITS_PER_UNIT) evenly.
2102 size * BITS_PER_UNIT is used here to make sure that padding bits
2103 (which might appear at either end of the value; real_to_target
2104 will include the padding bits in its output array) are included. */
2106 nunits = GET_MODE_SIZE (mode);
2107 bitsize = nunits * BITS_PER_UNIT;
2108 nelts = CEIL (bitsize, 32);
2109 units_per = 32 / BITS_PER_UNIT;
2111 real_to_target (data, &d, mode);
2113 /* Put out the first word with the specified alignment. */
2114 assemble_integer (GEN_INT (data[0]), MIN (nunits, units_per), align, 1);
2115 nunits -= units_per;
2117 /* Subsequent words need only 32-bit alignment. */
2118 align = min_align (align, 32);
2120 for (i = 1; i < nelts; i++)
2122 assemble_integer (GEN_INT (data[i]), MIN (nunits, units_per), align, 1);
2123 nunits -= units_per;
2127 /* Given an expression EXP with a constant value,
2128 reduce it to the sum of an assembler symbol and an integer.
2129 Store them both in the structure *VALUE.
2130 EXP must be reducible. */
2132 struct addr_const GTY(())
2134 rtx base;
2135 HOST_WIDE_INT offset;
2138 static void
2139 decode_addr_const (tree exp, struct addr_const *value)
2141 tree target = TREE_OPERAND (exp, 0);
2142 int offset = 0;
2143 rtx x;
2145 while (1)
2147 if (TREE_CODE (target) == COMPONENT_REF
2148 && host_integerp (byte_position (TREE_OPERAND (target, 1)), 0))
2151 offset += int_byte_position (TREE_OPERAND (target, 1));
2152 target = TREE_OPERAND (target, 0);
2154 else if (TREE_CODE (target) == ARRAY_REF
2155 || TREE_CODE (target) == ARRAY_RANGE_REF)
2157 offset += (tree_low_cst (TYPE_SIZE_UNIT (TREE_TYPE (target)), 1)
2158 * tree_low_cst (TREE_OPERAND (target, 1), 0));
2159 target = TREE_OPERAND (target, 0);
2161 else
2162 break;
2165 switch (TREE_CODE (target))
2167 case VAR_DECL:
2168 case FUNCTION_DECL:
2169 x = DECL_RTL (target);
2170 break;
2172 case LABEL_DECL:
2173 x = gen_rtx_MEM (FUNCTION_MODE,
2174 gen_rtx_LABEL_REF (Pmode, force_label_rtx (target)));
2175 break;
2177 case REAL_CST:
2178 case STRING_CST:
2179 case COMPLEX_CST:
2180 case CONSTRUCTOR:
2181 case INTEGER_CST:
2182 x = output_constant_def (target, 1);
2183 break;
2185 default:
2186 gcc_unreachable ();
2189 gcc_assert (MEM_P (x));
2190 x = XEXP (x, 0);
2192 value->base = x;
2193 value->offset = offset;
2196 /* Uniquize all constants that appear in memory.
2197 Each constant in memory thus far output is recorded
2198 in `const_desc_table'. */
2200 struct constant_descriptor_tree GTY(())
2202 /* A MEM for the constant. */
2203 rtx rtl;
2205 /* The value of the constant. */
2206 tree value;
2208 /* Hash of value. Computing the hash from value each time
2209 hashfn is called can't work properly, as that means recursive
2210 use of the hash table during hash table expansion. */
2211 hashval_t hash;
2214 static GTY((param_is (struct constant_descriptor_tree)))
2215 htab_t const_desc_htab;
2217 static struct constant_descriptor_tree * build_constant_desc (tree);
2218 static void maybe_output_constant_def_contents (struct constant_descriptor_tree *, int);
2220 /* Compute a hash code for a constant expression. */
2222 static hashval_t
2223 const_desc_hash (const void *ptr)
2225 return ((struct constant_descriptor_tree *)ptr)->hash;
2228 static hashval_t
2229 const_hash_1 (const tree exp)
2231 const char *p;
2232 hashval_t hi;
2233 int len, i;
2234 enum tree_code code = TREE_CODE (exp);
2236 /* Either set P and LEN to the address and len of something to hash and
2237 exit the switch or return a value. */
2239 switch (code)
2241 case INTEGER_CST:
2242 p = (char *) &TREE_INT_CST (exp);
2243 len = sizeof TREE_INT_CST (exp);
2244 break;
2246 case REAL_CST:
2247 return real_hash (TREE_REAL_CST_PTR (exp));
2249 case STRING_CST:
2250 p = TREE_STRING_POINTER (exp);
2251 len = TREE_STRING_LENGTH (exp);
2252 break;
2254 case COMPLEX_CST:
2255 return (const_hash_1 (TREE_REALPART (exp)) * 5
2256 + const_hash_1 (TREE_IMAGPART (exp)));
2258 case CONSTRUCTOR:
2260 unsigned HOST_WIDE_INT idx;
2261 tree value;
2263 hi = 5 + int_size_in_bytes (TREE_TYPE (exp));
2265 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (exp), idx, value)
2266 if (value)
2267 hi = hi * 603 + const_hash_1 (value);
2269 return hi;
2272 case ADDR_EXPR:
2273 case FDESC_EXPR:
2275 struct addr_const value;
2277 decode_addr_const (exp, &value);
2278 switch (GET_CODE (value.base))
2280 case SYMBOL_REF:
2281 /* Don't hash the address of the SYMBOL_REF;
2282 only use the offset and the symbol name. */
2283 hi = value.offset;
2284 p = XSTR (value.base, 0);
2285 for (i = 0; p[i] != 0; i++)
2286 hi = ((hi * 613) + (unsigned) (p[i]));
2287 break;
2289 case LABEL_REF:
2290 hi = value.offset + CODE_LABEL_NUMBER (XEXP (value.base, 0)) * 13;
2291 break;
2293 default:
2294 gcc_unreachable ();
2297 return hi;
2299 case PLUS_EXPR:
2300 case MINUS_EXPR:
2301 return (const_hash_1 (TREE_OPERAND (exp, 0)) * 9
2302 + const_hash_1 (TREE_OPERAND (exp, 1)));
2304 case NOP_EXPR:
2305 case CONVERT_EXPR:
2306 case NON_LVALUE_EXPR:
2307 return const_hash_1 (TREE_OPERAND (exp, 0)) * 7 + 2;
2309 default:
2310 /* A language specific constant. Just hash the code. */
2311 return code;
2314 /* Compute hashing function. */
2315 hi = len;
2316 for (i = 0; i < len; i++)
2317 hi = ((hi * 613) + (unsigned) (p[i]));
2319 return hi;
2322 /* Wrapper of compare_constant, for the htab interface. */
2323 static int
2324 const_desc_eq (const void *p1, const void *p2)
2326 const struct constant_descriptor_tree *c1 = p1;
2327 const struct constant_descriptor_tree *c2 = p2;
2328 if (c1->hash != c2->hash)
2329 return 0;
2330 return compare_constant (c1->value, c2->value);
2333 /* Compare t1 and t2, and return 1 only if they are known to result in
2334 the same bit pattern on output. */
2336 static int
2337 compare_constant (const tree t1, const tree t2)
2339 enum tree_code typecode;
2341 if (t1 == NULL_TREE)
2342 return t2 == NULL_TREE;
2343 if (t2 == NULL_TREE)
2344 return 0;
2346 if (TREE_CODE (t1) != TREE_CODE (t2))
2347 return 0;
2349 switch (TREE_CODE (t1))
2351 case INTEGER_CST:
2352 /* Integer constants are the same only if the same width of type. */
2353 if (TYPE_PRECISION (TREE_TYPE (t1)) != TYPE_PRECISION (TREE_TYPE (t2)))
2354 return 0;
2355 return tree_int_cst_equal (t1, t2);
2357 case REAL_CST:
2358 /* Real constants are the same only if the same width of type. */
2359 if (TYPE_PRECISION (TREE_TYPE (t1)) != TYPE_PRECISION (TREE_TYPE (t2)))
2360 return 0;
2362 return REAL_VALUES_IDENTICAL (TREE_REAL_CST (t1), TREE_REAL_CST (t2));
2364 case STRING_CST:
2365 if (TYPE_MODE (TREE_TYPE (t1)) != TYPE_MODE (TREE_TYPE (t2)))
2366 return 0;
2368 return (TREE_STRING_LENGTH (t1) == TREE_STRING_LENGTH (t2)
2369 && ! memcmp (TREE_STRING_POINTER (t1), TREE_STRING_POINTER (t2),
2370 TREE_STRING_LENGTH (t1)));
2372 case COMPLEX_CST:
2373 return (compare_constant (TREE_REALPART (t1), TREE_REALPART (t2))
2374 && compare_constant (TREE_IMAGPART (t1), TREE_IMAGPART (t2)));
2376 case CONSTRUCTOR:
2378 VEC(constructor_elt, gc) *v1, *v2;
2379 unsigned HOST_WIDE_INT idx;
2381 typecode = TREE_CODE (TREE_TYPE (t1));
2382 if (typecode != TREE_CODE (TREE_TYPE (t2)))
2383 return 0;
2385 if (typecode == ARRAY_TYPE)
2387 HOST_WIDE_INT size_1 = int_size_in_bytes (TREE_TYPE (t1));
2388 /* For arrays, check that the sizes all match. */
2389 if (TYPE_MODE (TREE_TYPE (t1)) != TYPE_MODE (TREE_TYPE (t2))
2390 || size_1 == -1
2391 || size_1 != int_size_in_bytes (TREE_TYPE (t2)))
2392 return 0;
2394 else
2396 /* For record and union constructors, require exact type
2397 equality. */
2398 if (TREE_TYPE (t1) != TREE_TYPE (t2))
2399 return 0;
2402 v1 = CONSTRUCTOR_ELTS (t1);
2403 v2 = CONSTRUCTOR_ELTS (t2);
2404 if (VEC_length (constructor_elt, v1)
2405 != VEC_length (constructor_elt, v2))
2406 return 0;
2408 for (idx = 0; idx < VEC_length (constructor_elt, v1); ++idx)
2410 constructor_elt *c1 = VEC_index (constructor_elt, v1, idx);
2411 constructor_elt *c2 = VEC_index (constructor_elt, v2, idx);
2413 /* Check that each value is the same... */
2414 if (!compare_constant (c1->value, c2->value))
2415 return 0;
2416 /* ... and that they apply to the same fields! */
2417 if (typecode == ARRAY_TYPE)
2419 if (!compare_constant (c1->index, c2->index))
2420 return 0;
2422 else
2424 if (c1->index != c2->index)
2425 return 0;
2429 return 1;
2432 case ADDR_EXPR:
2433 case FDESC_EXPR:
2435 struct addr_const value1, value2;
2437 decode_addr_const (t1, &value1);
2438 decode_addr_const (t2, &value2);
2439 return (value1.offset == value2.offset
2440 && strcmp (XSTR (value1.base, 0), XSTR (value2.base, 0)) == 0);
2443 case PLUS_EXPR:
2444 case MINUS_EXPR:
2445 case RANGE_EXPR:
2446 return (compare_constant (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0))
2447 && compare_constant(TREE_OPERAND (t1, 1), TREE_OPERAND (t2, 1)));
2449 case NOP_EXPR:
2450 case CONVERT_EXPR:
2451 case NON_LVALUE_EXPR:
2452 case VIEW_CONVERT_EXPR:
2453 return compare_constant (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
2455 default:
2457 tree nt1, nt2;
2458 nt1 = lang_hooks.expand_constant (t1);
2459 nt2 = lang_hooks.expand_constant (t2);
2460 if (nt1 != t1 || nt2 != t2)
2461 return compare_constant (nt1, nt2);
2462 else
2463 return 0;
2467 gcc_unreachable ();
2470 /* Make a copy of the whole tree structure for a constant. This
2471 handles the same types of nodes that compare_constant handles. */
2473 static tree
2474 copy_constant (tree exp)
2476 switch (TREE_CODE (exp))
2478 case ADDR_EXPR:
2479 /* For ADDR_EXPR, we do not want to copy the decl whose address
2480 is requested. We do want to copy constants though. */
2481 if (CONSTANT_CLASS_P (TREE_OPERAND (exp, 0)))
2482 return build1 (TREE_CODE (exp), TREE_TYPE (exp),
2483 copy_constant (TREE_OPERAND (exp, 0)));
2484 else
2485 return copy_node (exp);
2487 case INTEGER_CST:
2488 case REAL_CST:
2489 case STRING_CST:
2490 return copy_node (exp);
2492 case COMPLEX_CST:
2493 return build_complex (TREE_TYPE (exp),
2494 copy_constant (TREE_REALPART (exp)),
2495 copy_constant (TREE_IMAGPART (exp)));
2497 case PLUS_EXPR:
2498 case MINUS_EXPR:
2499 return build2 (TREE_CODE (exp), TREE_TYPE (exp),
2500 copy_constant (TREE_OPERAND (exp, 0)),
2501 copy_constant (TREE_OPERAND (exp, 1)));
2503 case NOP_EXPR:
2504 case CONVERT_EXPR:
2505 case NON_LVALUE_EXPR:
2506 case VIEW_CONVERT_EXPR:
2507 return build1 (TREE_CODE (exp), TREE_TYPE (exp),
2508 copy_constant (TREE_OPERAND (exp, 0)));
2510 case CONSTRUCTOR:
2512 tree copy = copy_node (exp);
2513 VEC(constructor_elt, gc) *v;
2514 unsigned HOST_WIDE_INT idx;
2515 tree purpose, value;
2517 v = VEC_alloc(constructor_elt, gc, VEC_length(constructor_elt,
2518 CONSTRUCTOR_ELTS (exp)));
2519 FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (exp), idx, purpose, value)
2521 constructor_elt *ce = VEC_quick_push (constructor_elt, v, NULL);
2522 ce->index = purpose;
2523 ce->value = copy_constant (value);
2525 CONSTRUCTOR_ELTS (copy) = v;
2526 return copy;
2529 default:
2531 tree t = lang_hooks.expand_constant (exp);
2533 gcc_assert (t == exp);
2534 return copy_constant (t);
2539 /* Subroutine of output_constant_def:
2540 No constant equal to EXP is known to have been output.
2541 Make a constant descriptor to enter EXP in the hash table.
2542 Assign the label number and construct RTL to refer to the
2543 constant's location in memory.
2544 Caller is responsible for updating the hash table. */
2546 static struct constant_descriptor_tree *
2547 build_constant_desc (tree exp)
2549 rtx symbol;
2550 rtx rtl;
2551 char label[256];
2552 int labelno;
2553 struct constant_descriptor_tree *desc;
2555 desc = ggc_alloc (sizeof (*desc));
2556 desc->value = copy_constant (exp);
2558 /* Propagate marked-ness to copied constant. */
2559 if (flag_mudflap && mf_marked_p (exp))
2560 mf_mark (desc->value);
2562 /* Create a string containing the label name, in LABEL. */
2563 labelno = const_labelno++;
2564 ASM_GENERATE_INTERNAL_LABEL (label, "LC", labelno);
2566 /* We have a symbol name; construct the SYMBOL_REF and the MEM. */
2567 symbol = gen_rtx_SYMBOL_REF (Pmode, ggc_strdup (label));
2568 SYMBOL_REF_FLAGS (symbol) = SYMBOL_FLAG_LOCAL;
2569 SYMBOL_REF_DECL (symbol) = desc->value;
2570 TREE_CONSTANT_POOL_ADDRESS_P (symbol) = 1;
2572 rtl = gen_rtx_MEM (TYPE_MODE (TREE_TYPE (exp)), symbol);
2573 set_mem_attributes (rtl, exp, 1);
2574 set_mem_alias_set (rtl, 0);
2575 set_mem_alias_set (rtl, const_alias_set);
2577 /* Set flags or add text to the name to record information, such as
2578 that it is a local symbol. If the name is changed, the macro
2579 ASM_OUTPUT_LABELREF will have to know how to strip this
2580 information. This call might invalidate our local variable
2581 SYMBOL; we can't use it afterward. */
2583 targetm.encode_section_info (exp, rtl, true);
2585 desc->rtl = rtl;
2587 return desc;
2590 /* Return an rtx representing a reference to constant data in memory
2591 for the constant expression EXP.
2593 If assembler code for such a constant has already been output,
2594 return an rtx to refer to it.
2595 Otherwise, output such a constant in memory
2596 and generate an rtx for it.
2598 If DEFER is nonzero, this constant can be deferred and output only
2599 if referenced in the function after all optimizations.
2601 `const_desc_table' records which constants already have label strings. */
2604 output_constant_def (tree exp, int defer)
2606 struct constant_descriptor_tree *desc;
2607 struct constant_descriptor_tree key;
2608 void **loc;
2610 /* Look up EXP in the table of constant descriptors. If we didn't find
2611 it, create a new one. */
2612 key.value = exp;
2613 key.hash = const_hash_1 (exp);
2614 loc = htab_find_slot_with_hash (const_desc_htab, &key, key.hash, INSERT);
2616 desc = *loc;
2617 if (desc == 0)
2619 desc = build_constant_desc (exp);
2620 desc->hash = key.hash;
2621 *loc = desc;
2624 maybe_output_constant_def_contents (desc, defer);
2625 return desc->rtl;
2628 /* Subroutine of output_constant_def: Decide whether or not we need to
2629 output the constant DESC now, and if so, do it. */
2630 static void
2631 maybe_output_constant_def_contents (struct constant_descriptor_tree *desc,
2632 int defer)
2634 rtx symbol = XEXP (desc->rtl, 0);
2635 tree exp = desc->value;
2637 if (flag_syntax_only)
2638 return;
2640 if (TREE_ASM_WRITTEN (exp))
2641 /* Already output; don't do it again. */
2642 return;
2644 /* We can always defer constants as long as the context allows
2645 doing so. */
2646 if (defer)
2648 /* Increment n_deferred_constants if it exists. It needs to be at
2649 least as large as the number of constants actually referred to
2650 by the function. If it's too small we'll stop looking too early
2651 and fail to emit constants; if it's too large we'll only look
2652 through the entire function when we could have stopped earlier. */
2653 if (cfun)
2654 n_deferred_constants++;
2655 return;
2658 output_constant_def_contents (symbol);
2661 /* We must output the constant data referred to by SYMBOL; do so. */
2663 static void
2664 output_constant_def_contents (rtx symbol)
2666 tree exp = SYMBOL_REF_DECL (symbol);
2667 const char *label = XSTR (symbol, 0);
2668 HOST_WIDE_INT size;
2670 /* Make sure any other constants whose addresses appear in EXP
2671 are assigned label numbers. */
2672 int reloc = compute_reloc_for_constant (exp);
2674 /* Align the location counter as required by EXP's data type. */
2675 unsigned int align = TYPE_ALIGN (TREE_TYPE (exp));
2676 #ifdef CONSTANT_ALIGNMENT
2677 align = CONSTANT_ALIGNMENT (exp, align);
2678 #endif
2680 output_addressed_constants (exp);
2682 /* We are no longer deferring this constant. */
2683 TREE_ASM_WRITTEN (exp) = 1;
2685 if (IN_NAMED_SECTION (exp))
2686 switch_to_section (get_named_section (exp, NULL, reloc));
2687 else
2688 switch_to_section (targetm.asm_out.select_section (exp, reloc, align));
2690 if (align > BITS_PER_UNIT)
2692 ASM_OUTPUT_ALIGN (asm_out_file, floor_log2 (align / BITS_PER_UNIT));
2695 size = int_size_in_bytes (TREE_TYPE (exp));
2696 if (TREE_CODE (exp) == STRING_CST)
2697 size = MAX (TREE_STRING_LENGTH (exp), size);
2699 /* Do any machine/system dependent processing of the constant. */
2700 #ifdef ASM_DECLARE_CONSTANT_NAME
2701 ASM_DECLARE_CONSTANT_NAME (asm_out_file, label, exp, size);
2702 #else
2703 /* Standard thing is just output label for the constant. */
2704 ASM_OUTPUT_LABEL (asm_out_file, label);
2705 #endif /* ASM_DECLARE_CONSTANT_NAME */
2707 /* Output the value of EXP. */
2708 output_constant (exp, size, align);
2709 if (flag_mudflap)
2710 mudflap_enqueue_constant (exp);
2713 /* Look up EXP in the table of constant descriptors. Return the rtl
2714 if it has been emitted, else null. */
2717 lookup_constant_def (tree exp)
2719 struct constant_descriptor_tree *desc;
2720 struct constant_descriptor_tree key;
2722 key.value = exp;
2723 key.hash = const_hash_1 (exp);
2724 desc = htab_find_with_hash (const_desc_htab, &key, key.hash);
2726 return (desc ? desc->rtl : NULL_RTX);
2729 /* Used in the hash tables to avoid outputting the same constant
2730 twice. Unlike 'struct constant_descriptor_tree', RTX constants
2731 are output once per function, not once per file. */
2732 /* ??? Only a few targets need per-function constant pools. Most
2733 can use one per-file pool. Should add a targetm bit to tell the
2734 difference. */
2736 struct rtx_constant_pool GTY(())
2738 /* Pointers to first and last constant in pool, as ordered by offset. */
2739 struct constant_descriptor_rtx *first;
2740 struct constant_descriptor_rtx *last;
2742 /* Hash facility for making memory-constants from constant rtl-expressions.
2743 It is used on RISC machines where immediate integer arguments and
2744 constant addresses are restricted so that such constants must be stored
2745 in memory. */
2746 htab_t GTY((param_is (struct constant_descriptor_rtx))) const_rtx_htab;
2747 htab_t GTY((param_is (struct constant_descriptor_rtx))) const_rtx_sym_htab;
2749 /* Current offset in constant pool (does not include any
2750 machine-specific header). */
2751 HOST_WIDE_INT offset;
2754 struct constant_descriptor_rtx GTY((chain_next ("%h.next")))
2756 struct constant_descriptor_rtx *next;
2757 rtx mem;
2758 rtx sym;
2759 rtx constant;
2760 HOST_WIDE_INT offset;
2761 hashval_t hash;
2762 enum machine_mode mode;
2763 unsigned int align;
2764 int labelno;
2765 int mark;
2768 /* Hash and compare functions for const_rtx_htab. */
2770 static hashval_t
2771 const_desc_rtx_hash (const void *ptr)
2773 const struct constant_descriptor_rtx *desc = ptr;
2774 return desc->hash;
2777 static int
2778 const_desc_rtx_eq (const void *a, const void *b)
2780 const struct constant_descriptor_rtx *x = a;
2781 const struct constant_descriptor_rtx *y = b;
2783 if (x->mode != y->mode)
2784 return 0;
2785 return rtx_equal_p (x->constant, y->constant);
2788 /* Hash and compare functions for const_rtx_sym_htab. */
2790 static hashval_t
2791 const_desc_rtx_sym_hash (const void *ptr)
2793 const struct constant_descriptor_rtx *desc = ptr;
2794 return htab_hash_string (XSTR (desc->sym, 0));
2797 static int
2798 const_desc_rtx_sym_eq (const void *a, const void *b)
2800 const struct constant_descriptor_rtx *x = a;
2801 const struct constant_descriptor_rtx *y = b;
2802 return XSTR (x->sym, 0) == XSTR (y->sym, 0);
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->const_rtx_sym_htab = htab_create_ggc (31, const_desc_rtx_sym_hash,
2909 const_desc_rtx_sym_eq, NULL);
2910 pool->first = pool->last = NULL;
2911 pool->offset = 0;
2914 /* Given a MINUS expression, simplify it if both sides
2915 include the same symbol. */
2918 simplify_subtraction (rtx x)
2920 rtx r = simplify_rtx (x);
2921 return r ? r : x;
2924 /* Given a constant rtx X, make (or find) a memory constant for its value
2925 and return a MEM rtx to refer to it in memory. */
2928 force_const_mem (enum machine_mode mode, rtx x)
2930 struct constant_descriptor_rtx *desc, tmp;
2931 struct rtx_constant_pool *pool = cfun->varasm->pool;
2932 char label[256];
2933 rtx def, symbol;
2934 hashval_t hash;
2935 unsigned int align;
2936 void **slot;
2938 /* If we're not allowed to drop X into the constant pool, don't. */
2939 if (targetm.cannot_force_const_mem (x))
2940 return NULL_RTX;
2942 /* Lookup the value in the hashtable. */
2943 tmp.constant = x;
2944 tmp.mode = mode;
2945 hash = const_rtx_hash (x);
2946 slot = htab_find_slot_with_hash (pool->const_rtx_htab, &tmp, hash, INSERT);
2947 desc = *slot;
2949 /* If the constant was already present, return its memory. */
2950 if (desc)
2951 return copy_rtx (desc->mem);
2953 /* Otherwise, create a new descriptor. */
2954 desc = ggc_alloc (sizeof (*desc));
2955 *slot = desc;
2957 /* Align the location counter as required by EXP's data type. */
2958 align = GET_MODE_ALIGNMENT (mode == VOIDmode ? word_mode : mode);
2959 #ifdef CONSTANT_ALIGNMENT
2961 tree type = lang_hooks.types.type_for_mode (mode, 0);
2962 if (type != NULL_TREE)
2963 align = CONSTANT_ALIGNMENT (make_tree (type, x), align);
2965 #endif
2967 pool->offset += (align / BITS_PER_UNIT) - 1;
2968 pool->offset &= ~ ((align / BITS_PER_UNIT) - 1);
2970 desc->next = NULL;
2971 desc->constant = tmp.constant;
2972 desc->offset = pool->offset;
2973 desc->hash = hash;
2974 desc->mode = mode;
2975 desc->align = align;
2976 desc->labelno = const_labelno;
2977 desc->mark = 0;
2979 pool->offset += GET_MODE_SIZE (mode);
2980 if (pool->last)
2981 pool->last->next = desc;
2982 else
2983 pool->first = pool->last = desc;
2984 pool->last = desc;
2986 /* Create a string containing the label name, in LABEL. */
2987 ASM_GENERATE_INTERNAL_LABEL (label, "LC", const_labelno);
2988 ++const_labelno;
2990 /* Construct the SYMBOL_REF. Make sure to mark it as belonging to
2991 the constants pool. */
2992 desc->sym = symbol = gen_rtx_SYMBOL_REF (Pmode, ggc_strdup (label));
2993 SYMBOL_REF_FLAGS (symbol) = SYMBOL_FLAG_LOCAL;
2994 CONSTANT_POOL_ADDRESS_P (symbol) = 1;
2995 current_function_uses_const_pool = 1;
2997 /* Insert the descriptor into the symbol cross-reference table too. */
2998 slot = htab_find_slot (pool->const_rtx_sym_htab, desc, INSERT);
2999 gcc_assert (!*slot);
3000 *slot = desc;
3002 /* Construct the MEM. */
3003 desc->mem = def = gen_const_mem (mode, symbol);
3004 set_mem_attributes (def, lang_hooks.types.type_for_mode (mode, 0), 1);
3005 set_mem_align (def, align);
3007 /* If we're dropping a label to the constant pool, make sure we
3008 don't delete it. */
3009 if (GET_CODE (x) == LABEL_REF)
3010 LABEL_PRESERVE_P (XEXP (x, 0)) = 1;
3012 return copy_rtx (def);
3015 /* Given a SYMBOL_REF with CONSTANT_POOL_ADDRESS_P true, return a pointer to
3016 the corresponding constant_descriptor_rtx structure. */
3018 static struct constant_descriptor_rtx *
3019 find_pool_constant (struct rtx_constant_pool *pool, rtx sym)
3021 struct constant_descriptor_rtx tmp;
3022 tmp.sym = sym;
3023 return htab_find (pool->const_rtx_sym_htab, &tmp);
3026 /* Given a constant pool SYMBOL_REF, return the corresponding constant. */
3029 get_pool_constant (rtx addr)
3031 return find_pool_constant (cfun->varasm->pool, addr)->constant;
3034 /* Given a constant pool SYMBOL_REF, return the corresponding constant
3035 and whether it has been output or not. */
3038 get_pool_constant_mark (rtx addr, bool *pmarked)
3040 struct constant_descriptor_rtx *desc;
3042 desc = find_pool_constant (cfun->varasm->pool, addr);
3043 *pmarked = (desc->mark != 0);
3044 return desc->constant;
3047 /* Likewise, but for the constant pool of a specific function. */
3050 get_pool_constant_for_function (struct function *f, rtx addr)
3052 return find_pool_constant (f->varasm->pool, addr)->constant;
3055 /* Similar, return the mode. */
3057 enum machine_mode
3058 get_pool_mode (rtx addr)
3060 return find_pool_constant (cfun->varasm->pool, addr)->mode;
3063 /* Return the size of the constant pool. */
3066 get_pool_size (void)
3068 return cfun->varasm->pool->offset;
3071 /* Worker function for output_constant_pool_1. Emit assembly for X
3072 in MODE with known alignment ALIGN. */
3074 static void
3075 output_constant_pool_2 (enum machine_mode mode, rtx x, unsigned int align)
3077 switch (GET_MODE_CLASS (mode))
3079 case MODE_FLOAT:
3080 case MODE_DECIMAL_FLOAT:
3082 REAL_VALUE_TYPE r;
3084 gcc_assert (GET_CODE (x) == CONST_DOUBLE);
3085 REAL_VALUE_FROM_CONST_DOUBLE (r, x);
3086 assemble_real (r, mode, align);
3087 break;
3090 case MODE_INT:
3091 case MODE_PARTIAL_INT:
3092 assemble_integer (x, GET_MODE_SIZE (mode), align, 1);
3093 break;
3095 case MODE_VECTOR_FLOAT:
3096 case MODE_VECTOR_INT:
3098 int i, units;
3099 enum machine_mode submode = GET_MODE_INNER (mode);
3100 unsigned int subalign = MIN (align, GET_MODE_BITSIZE (submode));
3102 gcc_assert (GET_CODE (x) == CONST_VECTOR);
3103 units = CONST_VECTOR_NUNITS (x);
3105 for (i = 0; i < units; i++)
3107 rtx elt = CONST_VECTOR_ELT (x, i);
3108 output_constant_pool_2 (submode, elt, i ? subalign : align);
3111 break;
3113 default:
3114 gcc_unreachable ();
3118 /* Worker function for output_constant_pool. Emit POOL. */
3120 static void
3121 output_constant_pool_1 (struct constant_descriptor_rtx *desc)
3123 rtx x, tmp;
3125 if (!desc->mark)
3126 return;
3127 x = desc->constant;
3129 /* See if X is a LABEL_REF (or a CONST referring to a LABEL_REF)
3130 whose CODE_LABEL has been deleted. This can occur if a jump table
3131 is eliminated by optimization. If so, write a constant of zero
3132 instead. Note that this can also happen by turning the
3133 CODE_LABEL into a NOTE. */
3134 /* ??? This seems completely and utterly wrong. Certainly it's
3135 not true for NOTE_INSN_DELETED_LABEL, but I disbelieve proper
3136 functioning even with INSN_DELETED_P and friends. */
3138 tmp = x;
3139 switch (GET_CODE (x))
3141 case CONST:
3142 if (GET_CODE (XEXP (x, 0)) != PLUS
3143 || GET_CODE (XEXP (XEXP (x, 0), 0)) != LABEL_REF)
3144 break;
3145 tmp = XEXP (XEXP (x, 0), 0);
3146 /* FALLTHRU */
3148 case LABEL_REF:
3149 tmp = XEXP (x, 0);
3150 gcc_assert (!INSN_DELETED_P (tmp));
3151 gcc_assert (!NOTE_P (tmp)
3152 || NOTE_LINE_NUMBER (tmp) != NOTE_INSN_DELETED);
3153 break;
3155 default:
3156 break;
3159 /* First switch to correct section. */
3160 switch_to_section (targetm.asm_out.select_rtx_section (desc->mode, x,
3161 desc->align));
3163 #ifdef ASM_OUTPUT_SPECIAL_POOL_ENTRY
3164 ASM_OUTPUT_SPECIAL_POOL_ENTRY (asm_out_file, x, desc->mode,
3165 desc->align, desc->labelno, done);
3166 #endif
3168 assemble_align (desc->align);
3170 /* Output the label. */
3171 targetm.asm_out.internal_label (asm_out_file, "LC", desc->labelno);
3173 /* Output the data. */
3174 output_constant_pool_2 (desc->mode, x, desc->align);
3176 /* Make sure all constants in SECTION_MERGE and not SECTION_STRINGS
3177 sections have proper size. */
3178 if (desc->align > GET_MODE_BITSIZE (desc->mode)
3179 && in_section
3180 && (in_section->common.flags & SECTION_MERGE))
3181 assemble_align (desc->align);
3183 #ifdef ASM_OUTPUT_SPECIAL_POOL_ENTRY
3184 done:
3185 #endif
3186 return;
3189 /* Given a SYMBOL_REF CURRENT_RTX, mark it and all constants it refers
3190 to as used. Emit referenced deferred strings. This function can
3191 be used with for_each_rtx to mark all SYMBOL_REFs in an rtx. */
3193 static int
3194 mark_constant (rtx *current_rtx, void *data)
3196 struct rtx_constant_pool *pool = data;
3197 rtx x = *current_rtx;
3199 if (x == NULL_RTX || GET_CODE (x) != SYMBOL_REF)
3200 return 0;
3202 if (CONSTANT_POOL_ADDRESS_P (x))
3204 struct constant_descriptor_rtx *desc = find_pool_constant (pool, x);
3205 if (desc->mark == 0)
3207 desc->mark = 1;
3208 for_each_rtx (&desc->constant, mark_constant, pool);
3211 else if (TREE_CONSTANT_POOL_ADDRESS_P (x))
3213 tree exp = SYMBOL_REF_DECL (x);
3214 if (!TREE_ASM_WRITTEN (exp))
3216 n_deferred_constants--;
3217 output_constant_def_contents (x);
3221 return -1;
3224 /* Look through appropriate parts of INSN, marking all entries in the
3225 constant pool which are actually being used. Entries that are only
3226 referenced by other constants are also marked as used. Emit
3227 deferred strings that are used. */
3229 static void
3230 mark_constants (struct rtx_constant_pool *pool, rtx insn)
3232 if (!INSN_P (insn))
3233 return;
3235 /* Insns may appear inside a SEQUENCE. Only check the patterns of
3236 insns, not any notes that may be attached. We don't want to mark
3237 a constant just because it happens to appear in a REG_EQUIV note. */
3238 if (GET_CODE (PATTERN (insn)) == SEQUENCE)
3240 rtx seq = PATTERN (insn);
3241 int i, n = XVECLEN (seq, 0);
3242 for (i = 0; i < n; ++i)
3244 rtx subinsn = XVECEXP (seq, 0, i);
3245 if (INSN_P (subinsn))
3246 for_each_rtx (&PATTERN (subinsn), mark_constant, pool);
3249 else
3250 for_each_rtx (&PATTERN (insn), mark_constant, pool);
3253 /* Look through the instructions for this function, and mark all the
3254 entries in POOL which are actually being used. Emit deferred constants
3255 which have indeed been used. */
3257 static void
3258 mark_constant_pool (struct rtx_constant_pool *pool)
3260 rtx insn, link;
3262 if (pool->first == 0 && n_deferred_constants == 0)
3263 return;
3265 for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
3266 mark_constants (pool, insn);
3268 for (link = current_function_epilogue_delay_list;
3269 link;
3270 link = XEXP (link, 1))
3271 mark_constants (pool, XEXP (link, 0));
3274 /* Write all the constants in the constant pool. */
3276 void
3277 output_constant_pool (const char *fnname ATTRIBUTE_UNUSED,
3278 tree fndecl ATTRIBUTE_UNUSED)
3280 struct rtx_constant_pool *pool = cfun->varasm->pool;
3281 struct constant_descriptor_rtx *desc;
3283 /* It is possible for gcc to call force_const_mem and then to later
3284 discard the instructions which refer to the constant. In such a
3285 case we do not need to output the constant. */
3286 mark_constant_pool (pool);
3288 #ifdef ASM_OUTPUT_POOL_PROLOGUE
3289 ASM_OUTPUT_POOL_PROLOGUE (asm_out_file, fnname, fndecl, pool->offset);
3290 #endif
3292 for (desc = pool->first; desc ; desc = desc->next)
3293 output_constant_pool_1 (desc);
3295 #ifdef ASM_OUTPUT_POOL_EPILOGUE
3296 ASM_OUTPUT_POOL_EPILOGUE (asm_out_file, fnname, fndecl, pool->offset);
3297 #endif
3300 /* Determine what kind of relocations EXP may need. */
3303 compute_reloc_for_constant (tree exp)
3305 int reloc = 0, reloc2;
3306 tree tem;
3308 /* Give the front-end a chance to convert VALUE to something that
3309 looks more like a constant to the back-end. */
3310 exp = lang_hooks.expand_constant (exp);
3312 switch (TREE_CODE (exp))
3314 case ADDR_EXPR:
3315 case FDESC_EXPR:
3316 /* Go inside any operations that get_inner_reference can handle and see
3317 if what's inside is a constant: no need to do anything here for
3318 addresses of variables or functions. */
3319 for (tem = TREE_OPERAND (exp, 0); handled_component_p (tem);
3320 tem = TREE_OPERAND (tem, 0))
3323 if (TREE_PUBLIC (tem))
3324 reloc |= 2;
3325 else
3326 reloc |= 1;
3327 break;
3329 case PLUS_EXPR:
3330 reloc = compute_reloc_for_constant (TREE_OPERAND (exp, 0));
3331 reloc |= compute_reloc_for_constant (TREE_OPERAND (exp, 1));
3332 break;
3334 case MINUS_EXPR:
3335 reloc = compute_reloc_for_constant (TREE_OPERAND (exp, 0));
3336 reloc2 = compute_reloc_for_constant (TREE_OPERAND (exp, 1));
3337 /* The difference of two local labels is computable at link time. */
3338 if (reloc == 1 && reloc2 == 1)
3339 reloc = 0;
3340 else
3341 reloc |= reloc2;
3342 break;
3344 case NOP_EXPR:
3345 case CONVERT_EXPR:
3346 case NON_LVALUE_EXPR:
3347 case VIEW_CONVERT_EXPR:
3348 reloc = compute_reloc_for_constant (TREE_OPERAND (exp, 0));
3349 break;
3351 case CONSTRUCTOR:
3353 unsigned HOST_WIDE_INT idx;
3354 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (exp), idx, tem)
3355 if (tem != 0)
3356 reloc |= compute_reloc_for_constant (tem);
3358 break;
3360 default:
3361 break;
3363 return reloc;
3366 /* Find all the constants whose addresses are referenced inside of EXP,
3367 and make sure assembler code with a label has been output for each one.
3368 Indicate whether an ADDR_EXPR has been encountered. */
3370 static void
3371 output_addressed_constants (tree exp)
3373 tree tem;
3375 /* Give the front-end a chance to convert VALUE to something that
3376 looks more like a constant to the back-end. */
3377 exp = lang_hooks.expand_constant (exp);
3379 switch (TREE_CODE (exp))
3381 case ADDR_EXPR:
3382 case FDESC_EXPR:
3383 /* Go inside any operations that get_inner_reference can handle and see
3384 if what's inside is a constant: no need to do anything here for
3385 addresses of variables or functions. */
3386 for (tem = TREE_OPERAND (exp, 0); handled_component_p (tem);
3387 tem = TREE_OPERAND (tem, 0))
3390 /* If we have an initialized CONST_DECL, retrieve the initializer. */
3391 if (TREE_CODE (tem) == CONST_DECL && DECL_INITIAL (tem))
3392 tem = DECL_INITIAL (tem);
3394 if (CONSTANT_CLASS_P (tem) || TREE_CODE (tem) == CONSTRUCTOR)
3395 output_constant_def (tem, 0);
3396 break;
3398 case PLUS_EXPR:
3399 case MINUS_EXPR:
3400 output_addressed_constants (TREE_OPERAND (exp, 1));
3401 /* Fall through. */
3403 case NOP_EXPR:
3404 case CONVERT_EXPR:
3405 case NON_LVALUE_EXPR:
3406 case VIEW_CONVERT_EXPR:
3407 output_addressed_constants (TREE_OPERAND (exp, 0));
3408 break;
3410 case CONSTRUCTOR:
3412 unsigned HOST_WIDE_INT idx;
3413 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (exp), idx, tem)
3414 if (tem != 0)
3415 output_addressed_constants (tem);
3417 break;
3419 default:
3420 break;
3424 /* Return nonzero if VALUE is a valid constant-valued expression
3425 for use in initializing a static variable; one that can be an
3426 element of a "constant" initializer.
3428 Return null_pointer_node if the value is absolute;
3429 if it is relocatable, return the variable that determines the relocation.
3430 We assume that VALUE has been folded as much as possible;
3431 therefore, we do not need to check for such things as
3432 arithmetic-combinations of integers. */
3434 tree
3435 initializer_constant_valid_p (tree value, tree endtype)
3437 /* Give the front-end a chance to convert VALUE to something that
3438 looks more like a constant to the back-end. */
3439 value = lang_hooks.expand_constant (value);
3441 switch (TREE_CODE (value))
3443 case CONSTRUCTOR:
3444 if ((TREE_CODE (TREE_TYPE (value)) == UNION_TYPE
3445 || TREE_CODE (TREE_TYPE (value)) == RECORD_TYPE)
3446 && TREE_CONSTANT (value)
3447 && !VEC_empty (constructor_elt, CONSTRUCTOR_ELTS (value)))
3449 unsigned HOST_WIDE_INT idx;
3450 tree elt;
3451 bool absolute = true;
3453 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (value), idx, elt)
3455 tree reloc;
3456 reloc = initializer_constant_valid_p (elt, TREE_TYPE (elt));
3457 if (!reloc)
3458 return NULL_TREE;
3459 if (reloc != null_pointer_node)
3460 absolute = false;
3462 /* For a non-absolute relocation, there is no single
3463 variable that can be "the variable that determines the
3464 relocation." */
3465 return absolute ? null_pointer_node : error_mark_node;
3468 return TREE_STATIC (value) ? null_pointer_node : NULL_TREE;
3470 case INTEGER_CST:
3471 case VECTOR_CST:
3472 case REAL_CST:
3473 case STRING_CST:
3474 case COMPLEX_CST:
3475 return null_pointer_node;
3477 case ADDR_EXPR:
3478 case FDESC_EXPR:
3479 value = staticp (TREE_OPERAND (value, 0));
3480 /* "&(*a).f" is like unto pointer arithmetic. If "a" turns out to
3481 be a constant, this is old-skool offsetof-like nonsense. */
3482 if (value
3483 && TREE_CODE (value) == INDIRECT_REF
3484 && TREE_CONSTANT (TREE_OPERAND (value, 0)))
3485 return null_pointer_node;
3486 /* Taking the address of a nested function involves a trampoline. */
3487 if (value
3488 && TREE_CODE (value) == FUNCTION_DECL
3489 && ((decl_function_context (value) && !DECL_NO_STATIC_CHAIN (value))
3490 || DECL_DLLIMPORT_P (value)))
3491 return NULL_TREE;
3492 return value;
3494 case VIEW_CONVERT_EXPR:
3495 case NON_LVALUE_EXPR:
3496 return initializer_constant_valid_p (TREE_OPERAND (value, 0), endtype);
3498 case CONVERT_EXPR:
3499 case NOP_EXPR:
3501 tree src;
3502 tree src_type;
3503 tree dest_type;
3505 src = TREE_OPERAND (value, 0);
3506 src_type = TREE_TYPE (src);
3507 dest_type = TREE_TYPE (value);
3509 /* Allow conversions between pointer types, floating-point
3510 types, and offset types. */
3511 if ((POINTER_TYPE_P (dest_type) && POINTER_TYPE_P (src_type))
3512 || (FLOAT_TYPE_P (dest_type) && FLOAT_TYPE_P (src_type))
3513 || (TREE_CODE (dest_type) == OFFSET_TYPE
3514 && TREE_CODE (src_type) == OFFSET_TYPE))
3515 return initializer_constant_valid_p (src, endtype);
3517 /* Allow length-preserving conversions between integer types. */
3518 if (INTEGRAL_TYPE_P (dest_type) && INTEGRAL_TYPE_P (src_type)
3519 && (TYPE_PRECISION (dest_type) == TYPE_PRECISION (src_type)))
3520 return initializer_constant_valid_p (src, endtype);
3522 /* Allow conversions between other integer types only if
3523 explicit value. */
3524 if (INTEGRAL_TYPE_P (dest_type) && INTEGRAL_TYPE_P (src_type))
3526 tree inner = initializer_constant_valid_p (src, endtype);
3527 if (inner == null_pointer_node)
3528 return null_pointer_node;
3529 break;
3532 /* Allow (int) &foo provided int is as wide as a pointer. */
3533 if (INTEGRAL_TYPE_P (dest_type) && POINTER_TYPE_P (src_type)
3534 && (TYPE_PRECISION (dest_type) >= TYPE_PRECISION (src_type)))
3535 return initializer_constant_valid_p (src, endtype);
3537 /* Likewise conversions from int to pointers, but also allow
3538 conversions from 0. */
3539 if ((POINTER_TYPE_P (dest_type)
3540 || TREE_CODE (dest_type) == OFFSET_TYPE)
3541 && INTEGRAL_TYPE_P (src_type))
3543 if (integer_zerop (src))
3544 return null_pointer_node;
3545 else if (TYPE_PRECISION (dest_type) <= TYPE_PRECISION (src_type))
3546 return initializer_constant_valid_p (src, endtype);
3549 /* Allow conversions to struct or union types if the value
3550 inside is okay. */
3551 if (TREE_CODE (dest_type) == RECORD_TYPE
3552 || TREE_CODE (dest_type) == UNION_TYPE)
3553 return initializer_constant_valid_p (src, endtype);
3555 break;
3557 case PLUS_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 /* If either term is absolute, use the other terms relocation. */
3566 if (valid0 == null_pointer_node)
3567 return valid1;
3568 if (valid1 == null_pointer_node)
3569 return valid0;
3571 break;
3573 case MINUS_EXPR:
3574 if (! INTEGRAL_TYPE_P (endtype)
3575 || TYPE_PRECISION (endtype) >= POINTER_SIZE)
3577 tree valid0 = initializer_constant_valid_p (TREE_OPERAND (value, 0),
3578 endtype);
3579 tree valid1 = initializer_constant_valid_p (TREE_OPERAND (value, 1),
3580 endtype);
3581 /* Win if second argument is absolute. */
3582 if (valid1 == null_pointer_node)
3583 return valid0;
3584 /* Win if both arguments have the same relocation.
3585 Then the value is absolute. */
3586 if (valid0 == valid1 && valid0 != 0)
3587 return null_pointer_node;
3589 /* Since GCC guarantees that string constants are unique in the
3590 generated code, a subtraction between two copies of the same
3591 constant string is absolute. */
3592 if (valid0 && TREE_CODE (valid0) == STRING_CST
3593 && valid1 && TREE_CODE (valid1) == STRING_CST
3594 && operand_equal_p (valid0, valid1, 1))
3595 return null_pointer_node;
3598 /* Support narrowing differences. */
3599 if (INTEGRAL_TYPE_P (endtype))
3601 tree op0, op1;
3603 op0 = TREE_OPERAND (value, 0);
3604 op1 = TREE_OPERAND (value, 1);
3606 /* Like STRIP_NOPS except allow the operand mode to widen.
3607 This works around a feature of fold that simplifies
3608 (int)(p1 - p2) to ((int)p1 - (int)p2) under the theory
3609 that the narrower operation is cheaper. */
3611 while (TREE_CODE (op0) == NOP_EXPR
3612 || TREE_CODE (op0) == CONVERT_EXPR
3613 || TREE_CODE (op0) == NON_LVALUE_EXPR)
3615 tree inner = TREE_OPERAND (op0, 0);
3616 if (inner == error_mark_node
3617 || ! INTEGRAL_MODE_P (TYPE_MODE (TREE_TYPE (inner)))
3618 || (GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op0)))
3619 > GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (inner)))))
3620 break;
3621 op0 = inner;
3624 while (TREE_CODE (op1) == NOP_EXPR
3625 || TREE_CODE (op1) == CONVERT_EXPR
3626 || TREE_CODE (op1) == NON_LVALUE_EXPR)
3628 tree inner = TREE_OPERAND (op1, 0);
3629 if (inner == error_mark_node
3630 || ! INTEGRAL_MODE_P (TYPE_MODE (TREE_TYPE (inner)))
3631 || (GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op1)))
3632 > GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (inner)))))
3633 break;
3634 op1 = inner;
3637 op0 = initializer_constant_valid_p (op0, endtype);
3638 op1 = initializer_constant_valid_p (op1, endtype);
3640 /* Both initializers must be known. */
3641 if (op0 && op1)
3643 if (op0 == op1)
3644 return null_pointer_node;
3646 /* Support differences between labels. */
3647 if (TREE_CODE (op0) == LABEL_DECL
3648 && TREE_CODE (op1) == LABEL_DECL)
3649 return null_pointer_node;
3651 if (TREE_CODE (op0) == STRING_CST
3652 && TREE_CODE (op1) == STRING_CST
3653 && operand_equal_p (op0, op1, 1))
3654 return null_pointer_node;
3657 break;
3659 default:
3660 break;
3663 return 0;
3666 /* Output assembler code for constant EXP to FILE, with no label.
3667 This includes the pseudo-op such as ".int" or ".byte", and a newline.
3668 Assumes output_addressed_constants has been done on EXP already.
3670 Generate exactly SIZE bytes of assembler data, padding at the end
3671 with zeros if necessary. SIZE must always be specified.
3673 SIZE is important for structure constructors,
3674 since trailing members may have been omitted from the constructor.
3675 It is also important for initialization of arrays from string constants
3676 since the full length of the string constant might not be wanted.
3677 It is also needed for initialization of unions, where the initializer's
3678 type is just one member, and that may not be as long as the union.
3680 There a case in which we would fail to output exactly SIZE bytes:
3681 for a structure constructor that wants to produce more than SIZE bytes.
3682 But such constructors will never be generated for any possible input.
3684 ALIGN is the alignment of the data in bits. */
3686 void
3687 output_constant (tree exp, unsigned HOST_WIDE_INT size, unsigned int align)
3689 enum tree_code code;
3690 unsigned HOST_WIDE_INT thissize;
3692 /* Some front-ends use constants other than the standard language-independent
3693 varieties, but which may still be output directly. Give the front-end a
3694 chance to convert EXP to a language-independent representation. */
3695 exp = lang_hooks.expand_constant (exp);
3697 if (size == 0 || flag_syntax_only)
3698 return;
3700 /* See if we're trying to initialize a pointer in a non-default mode
3701 to the address of some declaration somewhere. If the target says
3702 the mode is valid for pointers, assume the target has a way of
3703 resolving it. */
3704 if (TREE_CODE (exp) == NOP_EXPR
3705 && POINTER_TYPE_P (TREE_TYPE (exp))
3706 && targetm.valid_pointer_mode (TYPE_MODE (TREE_TYPE (exp))))
3708 tree saved_type = TREE_TYPE (exp);
3710 /* Peel off any intermediate conversions-to-pointer for valid
3711 pointer modes. */
3712 while (TREE_CODE (exp) == NOP_EXPR
3713 && POINTER_TYPE_P (TREE_TYPE (exp))
3714 && targetm.valid_pointer_mode (TYPE_MODE (TREE_TYPE (exp))))
3715 exp = TREE_OPERAND (exp, 0);
3717 /* If what we're left with is the address of something, we can
3718 convert the address to the final type and output it that
3719 way. */
3720 if (TREE_CODE (exp) == ADDR_EXPR)
3721 exp = build1 (ADDR_EXPR, saved_type, TREE_OPERAND (exp, 0));
3724 /* Eliminate any conversions since we'll be outputting the underlying
3725 constant. */
3726 while (TREE_CODE (exp) == NOP_EXPR || TREE_CODE (exp) == CONVERT_EXPR
3727 || TREE_CODE (exp) == NON_LVALUE_EXPR
3728 || TREE_CODE (exp) == VIEW_CONVERT_EXPR)
3730 HOST_WIDE_INT type_size = int_size_in_bytes (TREE_TYPE (exp));
3731 HOST_WIDE_INT op_size = int_size_in_bytes (TREE_TYPE (TREE_OPERAND (exp, 0)));
3733 /* Make sure eliminating the conversion is really a no-op, except with
3734 VIEW_CONVERT_EXPRs to allow for wild Ada unchecked conversions and
3735 union types to allow for Ada unchecked unions. */
3736 if (type_size > op_size
3737 && TREE_CODE (exp) != VIEW_CONVERT_EXPR
3738 && TREE_CODE (TREE_TYPE (exp)) != UNION_TYPE)
3739 internal_error ("no-op convert from %wd to %wd bytes in initializer",
3740 op_size, type_size);
3742 exp = TREE_OPERAND (exp, 0);
3745 code = TREE_CODE (TREE_TYPE (exp));
3746 thissize = int_size_in_bytes (TREE_TYPE (exp));
3748 /* Allow a constructor with no elements for any data type.
3749 This means to fill the space with zeros. */
3750 if (TREE_CODE (exp) == CONSTRUCTOR
3751 && VEC_empty (constructor_elt, CONSTRUCTOR_ELTS (exp)))
3753 assemble_zeros (size);
3754 return;
3757 if (TREE_CODE (exp) == FDESC_EXPR)
3759 #ifdef ASM_OUTPUT_FDESC
3760 HOST_WIDE_INT part = tree_low_cst (TREE_OPERAND (exp, 1), 0);
3761 tree decl = TREE_OPERAND (exp, 0);
3762 ASM_OUTPUT_FDESC (asm_out_file, decl, part);
3763 #else
3764 gcc_unreachable ();
3765 #endif
3766 return;
3769 /* Now output the underlying data. If we've handling the padding, return.
3770 Otherwise, break and ensure SIZE is the size written. */
3771 switch (code)
3773 case CHAR_TYPE:
3774 case BOOLEAN_TYPE:
3775 case INTEGER_TYPE:
3776 case ENUMERAL_TYPE:
3777 case POINTER_TYPE:
3778 case REFERENCE_TYPE:
3779 case OFFSET_TYPE:
3780 if (! assemble_integer (expand_expr (exp, NULL_RTX, VOIDmode,
3781 EXPAND_INITIALIZER),
3782 MIN (size, thissize), align, 0))
3783 error ("initializer for integer value is too complicated");
3784 break;
3786 case REAL_TYPE:
3787 if (TREE_CODE (exp) != REAL_CST)
3788 error ("initializer for floating value is not a floating constant");
3790 assemble_real (TREE_REAL_CST (exp), TYPE_MODE (TREE_TYPE (exp)), align);
3791 break;
3793 case COMPLEX_TYPE:
3794 output_constant (TREE_REALPART (exp), thissize / 2, align);
3795 output_constant (TREE_IMAGPART (exp), thissize / 2,
3796 min_align (align, BITS_PER_UNIT * (thissize / 2)));
3797 break;
3799 case ARRAY_TYPE:
3800 case VECTOR_TYPE:
3801 switch (TREE_CODE (exp))
3803 case CONSTRUCTOR:
3804 output_constructor (exp, size, align);
3805 return;
3806 case STRING_CST:
3807 thissize = MIN ((unsigned HOST_WIDE_INT)TREE_STRING_LENGTH (exp),
3808 size);
3809 assemble_string (TREE_STRING_POINTER (exp), thissize);
3810 break;
3812 case VECTOR_CST:
3814 int elt_size;
3815 tree link;
3816 unsigned int nalign;
3817 enum machine_mode inner;
3819 inner = TYPE_MODE (TREE_TYPE (TREE_TYPE (exp)));
3820 nalign = MIN (align, GET_MODE_ALIGNMENT (inner));
3822 elt_size = GET_MODE_SIZE (inner);
3824 link = TREE_VECTOR_CST_ELTS (exp);
3825 output_constant (TREE_VALUE (link), elt_size, align);
3826 while ((link = TREE_CHAIN (link)) != NULL)
3827 output_constant (TREE_VALUE (link), elt_size, nalign);
3828 break;
3830 default:
3831 gcc_unreachable ();
3833 break;
3835 case RECORD_TYPE:
3836 case UNION_TYPE:
3837 gcc_assert (TREE_CODE (exp) == CONSTRUCTOR);
3838 output_constructor (exp, size, align);
3839 return;
3841 case ERROR_MARK:
3842 return;
3844 default:
3845 gcc_unreachable ();
3848 if (size > thissize)
3849 assemble_zeros (size - thissize);
3853 /* Subroutine of output_constructor, used for computing the size of
3854 arrays of unspecified length. VAL must be a CONSTRUCTOR of an array
3855 type with an unspecified upper bound. */
3857 static unsigned HOST_WIDE_INT
3858 array_size_for_constructor (tree val)
3860 tree max_index, i;
3861 unsigned HOST_WIDE_INT cnt;
3862 tree index, value;
3864 /* This code used to attempt to handle string constants that are not
3865 arrays of single-bytes, but nothing else does, so there's no point in
3866 doing it here. */
3867 if (TREE_CODE (val) == STRING_CST)
3868 return TREE_STRING_LENGTH (val);
3870 max_index = NULL_TREE;
3871 FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (val), cnt, index, value)
3873 if (TREE_CODE (index) == RANGE_EXPR)
3874 index = TREE_OPERAND (index, 1);
3875 if (max_index == NULL_TREE || tree_int_cst_lt (max_index, index))
3876 max_index = index;
3879 if (max_index == NULL_TREE)
3880 return 0;
3882 /* Compute the total number of array elements. */
3883 i = size_binop (MINUS_EXPR, convert (sizetype, max_index),
3884 convert (sizetype,
3885 TYPE_MIN_VALUE (TYPE_DOMAIN (TREE_TYPE (val)))));
3886 i = size_binop (PLUS_EXPR, i, convert (sizetype, integer_one_node));
3888 /* Multiply by the array element unit size to find number of bytes. */
3889 i = size_binop (MULT_EXPR, i, TYPE_SIZE_UNIT (TREE_TYPE (TREE_TYPE (val))));
3891 return tree_low_cst (i, 1);
3894 /* Subroutine of output_constant, used for CONSTRUCTORs (aggregate constants).
3895 Generate at least SIZE bytes, padding if necessary. */
3897 static void
3898 output_constructor (tree exp, unsigned HOST_WIDE_INT size,
3899 unsigned int align)
3901 tree type = TREE_TYPE (exp);
3902 tree field = 0;
3903 tree min_index = 0;
3904 /* Number of bytes output or skipped so far.
3905 In other words, current position within the constructor. */
3906 HOST_WIDE_INT total_bytes = 0;
3907 /* Nonzero means BYTE contains part of a byte, to be output. */
3908 int byte_buffer_in_use = 0;
3909 int byte = 0;
3910 unsigned HOST_WIDE_INT cnt;
3911 constructor_elt *ce;
3913 gcc_assert (HOST_BITS_PER_WIDE_INT >= BITS_PER_UNIT);
3915 if (TREE_CODE (type) == RECORD_TYPE)
3916 field = TYPE_FIELDS (type);
3918 if (TREE_CODE (type) == ARRAY_TYPE
3919 && TYPE_DOMAIN (type) != 0)
3920 min_index = TYPE_MIN_VALUE (TYPE_DOMAIN (type));
3922 /* As LINK goes through the elements of the constant,
3923 FIELD goes through the structure fields, if the constant is a structure.
3924 if the constant is a union, then we override this,
3925 by getting the field from the TREE_LIST element.
3926 But the constant could also be an array. Then FIELD is zero.
3928 There is always a maximum of one element in the chain LINK for unions
3929 (even if the initializer in a source program incorrectly contains
3930 more one). */
3931 for (cnt = 0;
3932 VEC_iterate (constructor_elt, CONSTRUCTOR_ELTS (exp), cnt, ce);
3933 cnt++, field = field ? TREE_CHAIN (field) : 0)
3935 tree val = ce->value;
3936 tree index = 0;
3938 /* The element in a union constructor specifies the proper field
3939 or index. */
3940 if ((TREE_CODE (type) == RECORD_TYPE || TREE_CODE (type) == UNION_TYPE
3941 || TREE_CODE (type) == QUAL_UNION_TYPE)
3942 && ce->index != 0)
3943 field = ce->index;
3945 else if (TREE_CODE (type) == ARRAY_TYPE)
3946 index = ce->index;
3948 #ifdef ASM_COMMENT_START
3949 if (field && flag_verbose_asm)
3950 fprintf (asm_out_file, "%s %s:\n",
3951 ASM_COMMENT_START,
3952 DECL_NAME (field)
3953 ? IDENTIFIER_POINTER (DECL_NAME (field))
3954 : "<anonymous>");
3955 #endif
3957 /* Eliminate the marker that makes a cast not be an lvalue. */
3958 if (val != 0)
3959 STRIP_NOPS (val);
3961 if (index && TREE_CODE (index) == RANGE_EXPR)
3963 unsigned HOST_WIDE_INT fieldsize
3964 = int_size_in_bytes (TREE_TYPE (type));
3965 HOST_WIDE_INT lo_index = tree_low_cst (TREE_OPERAND (index, 0), 0);
3966 HOST_WIDE_INT hi_index = tree_low_cst (TREE_OPERAND (index, 1), 0);
3967 HOST_WIDE_INT index;
3968 unsigned int align2 = min_align (align, fieldsize * BITS_PER_UNIT);
3970 for (index = lo_index; index <= hi_index; index++)
3972 /* Output the element's initial value. */
3973 if (val == 0)
3974 assemble_zeros (fieldsize);
3975 else
3976 output_constant (val, fieldsize, align2);
3978 /* Count its size. */
3979 total_bytes += fieldsize;
3982 else if (field == 0 || !DECL_BIT_FIELD (field))
3984 /* An element that is not a bit-field. */
3986 unsigned HOST_WIDE_INT fieldsize;
3987 /* Since this structure is static,
3988 we know the positions are constant. */
3989 HOST_WIDE_INT pos = field ? int_byte_position (field) : 0;
3990 unsigned int align2;
3992 if (index != 0)
3993 pos = (tree_low_cst (TYPE_SIZE_UNIT (TREE_TYPE (val)), 1)
3994 * (tree_low_cst (index, 0) - tree_low_cst (min_index, 0)));
3996 /* Output any buffered-up bit-fields preceding this element. */
3997 if (byte_buffer_in_use)
3999 assemble_integer (GEN_INT (byte), 1, BITS_PER_UNIT, 1);
4000 total_bytes++;
4001 byte_buffer_in_use = 0;
4004 /* Advance to offset of this element.
4005 Note no alignment needed in an array, since that is guaranteed
4006 if each element has the proper size. */
4007 if ((field != 0 || index != 0) && pos != total_bytes)
4009 gcc_assert (pos >= total_bytes);
4010 assemble_zeros (pos - total_bytes);
4011 total_bytes = pos;
4014 /* Find the alignment of this element. */
4015 align2 = min_align (align, BITS_PER_UNIT * pos);
4017 /* Determine size this element should occupy. */
4018 if (field)
4020 fieldsize = 0;
4022 /* If this is an array with an unspecified upper bound,
4023 the initializer determines the size. */
4024 /* ??? This ought to only checked if DECL_SIZE_UNIT is NULL,
4025 but we cannot do this until the deprecated support for
4026 initializing zero-length array members is removed. */
4027 if (TREE_CODE (TREE_TYPE (field)) == ARRAY_TYPE
4028 && TYPE_DOMAIN (TREE_TYPE (field))
4029 && ! TYPE_MAX_VALUE (TYPE_DOMAIN (TREE_TYPE (field))))
4031 fieldsize = array_size_for_constructor (val);
4032 /* Given a non-empty initialization, this field had
4033 better be last. */
4034 gcc_assert (!fieldsize || !TREE_CHAIN (field));
4036 else if (DECL_SIZE_UNIT (field))
4038 /* ??? This can't be right. If the decl size overflows
4039 a host integer we will silently emit no data. */
4040 if (host_integerp (DECL_SIZE_UNIT (field), 1))
4041 fieldsize = tree_low_cst (DECL_SIZE_UNIT (field), 1);
4044 else
4045 fieldsize = int_size_in_bytes (TREE_TYPE (type));
4047 /* Output the element's initial value. */
4048 if (val == 0)
4049 assemble_zeros (fieldsize);
4050 else
4051 output_constant (val, fieldsize, align2);
4053 /* Count its size. */
4054 total_bytes += fieldsize;
4056 else if (val != 0 && TREE_CODE (val) != INTEGER_CST)
4057 error ("invalid initial value for member %qs",
4058 IDENTIFIER_POINTER (DECL_NAME (field)));
4059 else
4061 /* Element that is a bit-field. */
4063 HOST_WIDE_INT next_offset = int_bit_position (field);
4064 HOST_WIDE_INT end_offset
4065 = (next_offset + tree_low_cst (DECL_SIZE (field), 1));
4067 if (val == 0)
4068 val = integer_zero_node;
4070 /* If this field does not start in this (or, next) byte,
4071 skip some bytes. */
4072 if (next_offset / BITS_PER_UNIT != total_bytes)
4074 /* Output remnant of any bit field in previous bytes. */
4075 if (byte_buffer_in_use)
4077 assemble_integer (GEN_INT (byte), 1, BITS_PER_UNIT, 1);
4078 total_bytes++;
4079 byte_buffer_in_use = 0;
4082 /* If still not at proper byte, advance to there. */
4083 if (next_offset / BITS_PER_UNIT != total_bytes)
4085 gcc_assert (next_offset / BITS_PER_UNIT >= total_bytes);
4086 assemble_zeros (next_offset / BITS_PER_UNIT - total_bytes);
4087 total_bytes = next_offset / BITS_PER_UNIT;
4091 if (! byte_buffer_in_use)
4092 byte = 0;
4094 /* We must split the element into pieces that fall within
4095 separate bytes, and combine each byte with previous or
4096 following bit-fields. */
4098 /* next_offset is the offset n fbits from the beginning of
4099 the structure to the next bit of this element to be processed.
4100 end_offset is the offset of the first bit past the end of
4101 this element. */
4102 while (next_offset < end_offset)
4104 int this_time;
4105 int shift;
4106 HOST_WIDE_INT value;
4107 HOST_WIDE_INT next_byte = next_offset / BITS_PER_UNIT;
4108 HOST_WIDE_INT next_bit = next_offset % BITS_PER_UNIT;
4110 /* Advance from byte to byte
4111 within this element when necessary. */
4112 while (next_byte != total_bytes)
4114 assemble_integer (GEN_INT (byte), 1, BITS_PER_UNIT, 1);
4115 total_bytes++;
4116 byte = 0;
4119 /* Number of bits we can process at once
4120 (all part of the same byte). */
4121 this_time = MIN (end_offset - next_offset,
4122 BITS_PER_UNIT - next_bit);
4123 if (BYTES_BIG_ENDIAN)
4125 /* On big-endian machine, take the most significant bits
4126 first (of the bits that are significant)
4127 and put them into bytes from the most significant end. */
4128 shift = end_offset - next_offset - this_time;
4130 /* Don't try to take a bunch of bits that cross
4131 the word boundary in the INTEGER_CST. We can
4132 only select bits from the LOW or HIGH part
4133 not from both. */
4134 if (shift < HOST_BITS_PER_WIDE_INT
4135 && shift + this_time > HOST_BITS_PER_WIDE_INT)
4137 this_time = shift + this_time - HOST_BITS_PER_WIDE_INT;
4138 shift = HOST_BITS_PER_WIDE_INT;
4141 /* Now get the bits from the appropriate constant word. */
4142 if (shift < HOST_BITS_PER_WIDE_INT)
4143 value = TREE_INT_CST_LOW (val);
4144 else
4146 gcc_assert (shift < 2 * HOST_BITS_PER_WIDE_INT);
4147 value = TREE_INT_CST_HIGH (val);
4148 shift -= HOST_BITS_PER_WIDE_INT;
4151 /* Get the result. This works only when:
4152 1 <= this_time <= HOST_BITS_PER_WIDE_INT. */
4153 byte |= (((value >> shift)
4154 & (((HOST_WIDE_INT) 2 << (this_time - 1)) - 1))
4155 << (BITS_PER_UNIT - this_time - next_bit));
4157 else
4159 /* On little-endian machines,
4160 take first the least significant bits of the value
4161 and pack them starting at the least significant
4162 bits of the bytes. */
4163 shift = next_offset - int_bit_position (field);
4165 /* Don't try to take a bunch of bits that cross
4166 the word boundary in the INTEGER_CST. We can
4167 only select bits from the LOW or HIGH part
4168 not from both. */
4169 if (shift < HOST_BITS_PER_WIDE_INT
4170 && shift + this_time > HOST_BITS_PER_WIDE_INT)
4171 this_time = (HOST_BITS_PER_WIDE_INT - shift);
4173 /* Now get the bits from the appropriate constant word. */
4174 if (shift < HOST_BITS_PER_WIDE_INT)
4175 value = TREE_INT_CST_LOW (val);
4176 else
4178 gcc_assert (shift < 2 * HOST_BITS_PER_WIDE_INT);
4179 value = TREE_INT_CST_HIGH (val);
4180 shift -= HOST_BITS_PER_WIDE_INT;
4183 /* Get the result. This works only when:
4184 1 <= this_time <= HOST_BITS_PER_WIDE_INT. */
4185 byte |= (((value >> shift)
4186 & (((HOST_WIDE_INT) 2 << (this_time - 1)) - 1))
4187 << next_bit);
4190 next_offset += this_time;
4191 byte_buffer_in_use = 1;
4196 if (byte_buffer_in_use)
4198 assemble_integer (GEN_INT (byte), 1, BITS_PER_UNIT, 1);
4199 total_bytes++;
4202 if ((unsigned HOST_WIDE_INT)total_bytes < size)
4203 assemble_zeros (size - total_bytes);
4206 /* This TREE_LIST contains any weak symbol declarations waiting
4207 to be emitted. */
4208 static GTY(()) tree weak_decls;
4210 /* Mark DECL as weak. */
4212 static void
4213 mark_weak (tree decl)
4215 DECL_WEAK (decl) = 1;
4217 if (DECL_RTL_SET_P (decl)
4218 && MEM_P (DECL_RTL (decl))
4219 && XEXP (DECL_RTL (decl), 0)
4220 && GET_CODE (XEXP (DECL_RTL (decl), 0)) == SYMBOL_REF)
4221 SYMBOL_REF_WEAK (XEXP (DECL_RTL (decl), 0)) = 1;
4224 /* Merge weak status between NEWDECL and OLDDECL. */
4226 void
4227 merge_weak (tree newdecl, tree olddecl)
4229 if (DECL_WEAK (newdecl) == DECL_WEAK (olddecl))
4231 if (DECL_WEAK (newdecl) && SUPPORTS_WEAK)
4233 tree *pwd;
4234 /* We put the NEWDECL on the weak_decls list at some point
4235 and OLDDECL as well. Keep just OLDDECL on the list. */
4236 for (pwd = &weak_decls; *pwd; pwd = &TREE_CHAIN (*pwd))
4237 if (TREE_VALUE (*pwd) == newdecl)
4239 *pwd = TREE_CHAIN (*pwd);
4240 break;
4243 return;
4246 if (DECL_WEAK (newdecl))
4248 tree wd;
4250 /* NEWDECL is weak, but OLDDECL is not. */
4252 /* If we already output the OLDDECL, we're in trouble; we can't
4253 go back and make it weak. This error cannot caught in
4254 declare_weak because the NEWDECL and OLDDECL was not yet
4255 been merged; therefore, TREE_ASM_WRITTEN was not set. */
4256 if (TREE_ASM_WRITTEN (olddecl))
4257 error ("weak declaration of %q+D must precede definition",
4258 newdecl);
4260 /* If we've already generated rtl referencing OLDDECL, we may
4261 have done so in a way that will not function properly with
4262 a weak symbol. */
4263 else if (TREE_USED (olddecl)
4264 && TREE_SYMBOL_REFERENCED (DECL_ASSEMBLER_NAME (olddecl)))
4265 warning (0, "weak declaration of %q+D after first use results "
4266 "in unspecified behavior", newdecl);
4268 if (SUPPORTS_WEAK)
4270 /* We put the NEWDECL on the weak_decls list at some point.
4271 Replace it with the OLDDECL. */
4272 for (wd = weak_decls; wd; wd = TREE_CHAIN (wd))
4273 if (TREE_VALUE (wd) == newdecl)
4275 TREE_VALUE (wd) = olddecl;
4276 break;
4278 /* We may not find the entry on the list. If NEWDECL is a
4279 weak alias, then we will have already called
4280 globalize_decl to remove the entry; in that case, we do
4281 not need to do anything. */
4284 /* Make the OLDDECL weak; it's OLDDECL that we'll be keeping. */
4285 mark_weak (olddecl);
4287 else
4288 /* OLDDECL was weak, but NEWDECL was not explicitly marked as
4289 weak. Just update NEWDECL to indicate that it's weak too. */
4290 mark_weak (newdecl);
4293 /* Declare DECL to be a weak symbol. */
4295 void
4296 declare_weak (tree decl)
4298 if (! TREE_PUBLIC (decl))
4299 error ("weak declaration of %q+D must be public", decl);
4300 else if (TREE_CODE (decl) == FUNCTION_DECL && TREE_ASM_WRITTEN (decl))
4301 error ("weak declaration of %q+D must precede definition", decl);
4302 else if (SUPPORTS_WEAK)
4304 if (! DECL_WEAK (decl))
4305 weak_decls = tree_cons (NULL, decl, weak_decls);
4307 else
4308 warning (0, "weak declaration of %q+D not supported", decl);
4310 mark_weak (decl);
4313 static void
4314 weak_finish_1 (tree decl)
4316 #if defined (ASM_WEAKEN_DECL) || defined (ASM_WEAKEN_LABEL)
4317 const char *const name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
4318 #endif
4320 if (! TREE_USED (decl))
4321 return;
4323 #ifdef ASM_WEAKEN_DECL
4324 ASM_WEAKEN_DECL (asm_out_file, decl, name, NULL);
4325 #else
4326 #ifdef ASM_WEAKEN_LABEL
4327 ASM_WEAKEN_LABEL (asm_out_file, name);
4328 #else
4329 #ifdef ASM_OUTPUT_WEAK_ALIAS
4331 static bool warn_once = 0;
4332 if (! warn_once)
4334 warning (0, "only weak aliases are supported in this configuration");
4335 warn_once = 1;
4337 return;
4339 #endif
4340 #endif
4341 #endif
4344 /* This TREE_LIST contains weakref targets. */
4346 static GTY(()) tree weakref_targets;
4348 /* Forward declaration. */
4349 static tree find_decl_and_mark_needed (tree decl, tree target);
4351 /* Emit any pending weak declarations. */
4353 void
4354 weak_finish (void)
4356 tree t;
4358 for (t = weakref_targets; t; t = TREE_CHAIN (t))
4360 tree alias_decl = TREE_PURPOSE (t);
4361 tree target = ultimate_transparent_alias_target (&TREE_VALUE (t));
4363 if (! TREE_SYMBOL_REFERENCED (DECL_ASSEMBLER_NAME (alias_decl)))
4364 /* Remove alias_decl from the weak list, but leave entries for
4365 the target alone. */
4366 target = NULL_TREE;
4367 #ifndef ASM_OUTPUT_WEAKREF
4368 else if (! TREE_SYMBOL_REFERENCED (target))
4370 /* Use ASM_WEAKEN_LABEL only if ASM_WEAKEN_DECL is not
4371 defined, otherwise we and weak_finish_1 would use a
4372 different macros. */
4373 # if defined ASM_WEAKEN_LABEL && ! defined ASM_WEAKEN_DECL
4374 ASM_WEAKEN_LABEL (asm_out_file, IDENTIFIER_POINTER (target));
4375 # else
4376 tree decl = find_decl_and_mark_needed (alias_decl, target);
4378 if (! decl)
4380 decl = build_decl (TREE_CODE (alias_decl), target,
4381 TREE_TYPE (alias_decl));
4383 DECL_EXTERNAL (decl) = 1;
4384 TREE_PUBLIC (decl) = 1;
4385 DECL_ARTIFICIAL (decl) = 1;
4386 TREE_NOTHROW (decl) = TREE_NOTHROW (alias_decl);
4387 TREE_USED (decl) = 1;
4390 weak_finish_1 (decl);
4391 # endif
4393 #endif
4396 tree *p;
4397 tree t2;
4399 /* Remove the alias and the target from the pending weak list
4400 so that we do not emit any .weak directives for the former,
4401 nor multiple .weak directives for the latter. */
4402 for (p = &weak_decls; (t2 = *p) ; )
4404 if (TREE_VALUE (t2) == alias_decl
4405 || target == DECL_ASSEMBLER_NAME (TREE_VALUE (t2)))
4406 *p = TREE_CHAIN (t2);
4407 else
4408 p = &TREE_CHAIN (t2);
4411 /* Remove other weakrefs to the same target, to speed things up. */
4412 for (p = &TREE_CHAIN (t); (t2 = *p) ; )
4414 if (target == ultimate_transparent_alias_target (&TREE_VALUE (t2)))
4415 *p = TREE_CHAIN (t2);
4416 else
4417 p = &TREE_CHAIN (t2);
4422 for (t = weak_decls; t; t = TREE_CHAIN (t))
4424 tree decl = TREE_VALUE (t);
4426 weak_finish_1 (decl);
4430 /* Emit the assembly bits to indicate that DECL is globally visible. */
4432 static void
4433 globalize_decl (tree decl)
4435 const char *name = XSTR (XEXP (DECL_RTL (decl), 0), 0);
4437 #if defined (ASM_WEAKEN_LABEL) || defined (ASM_WEAKEN_DECL)
4438 if (DECL_WEAK (decl))
4440 tree *p, t;
4442 #ifdef ASM_WEAKEN_DECL
4443 ASM_WEAKEN_DECL (asm_out_file, decl, name, 0);
4444 #else
4445 ASM_WEAKEN_LABEL (asm_out_file, name);
4446 #endif
4448 /* Remove this function from the pending weak list so that
4449 we do not emit multiple .weak directives for it. */
4450 for (p = &weak_decls; (t = *p) ; )
4452 if (DECL_ASSEMBLER_NAME (decl) == DECL_ASSEMBLER_NAME (TREE_VALUE (t)))
4453 *p = TREE_CHAIN (t);
4454 else
4455 p = &TREE_CHAIN (t);
4458 /* Remove weakrefs to the same target from the pending weakref
4459 list, for the same reason. */
4460 for (p = &weakref_targets; (t = *p) ; )
4462 if (DECL_ASSEMBLER_NAME (decl)
4463 == ultimate_transparent_alias_target (&TREE_VALUE (t)))
4464 *p = TREE_CHAIN (t);
4465 else
4466 p = &TREE_CHAIN (t);
4469 return;
4471 #elif defined(ASM_MAKE_LABEL_LINKONCE)
4472 if (DECL_ONE_ONLY (decl))
4473 ASM_MAKE_LABEL_LINKONCE (asm_out_file, name);
4474 #endif
4476 targetm.asm_out.globalize_label (asm_out_file, name);
4479 /* We have to be able to tell cgraph about the needed-ness of the target
4480 of an alias. This requires that the decl have been defined. Aliases
4481 that precede their definition have to be queued for later processing. */
4483 typedef struct alias_pair GTY(())
4485 tree decl;
4486 tree target;
4487 } alias_pair;
4489 /* Define gc'd vector type. */
4490 DEF_VEC_O(alias_pair);
4491 DEF_VEC_ALLOC_O(alias_pair,gc);
4493 static GTY(()) VEC(alias_pair,gc) *alias_pairs;
4495 /* Given an assembly name, find the decl it is associated with. At the
4496 same time, mark it needed for cgraph. */
4498 static tree
4499 find_decl_and_mark_needed (tree decl, tree target)
4501 struct cgraph_node *fnode = NULL;
4502 struct cgraph_varpool_node *vnode = NULL;
4504 if (TREE_CODE (decl) == FUNCTION_DECL)
4506 fnode = cgraph_node_for_asm (target);
4507 if (fnode == NULL)
4508 vnode = cgraph_varpool_node_for_asm (target);
4510 else
4512 vnode = cgraph_varpool_node_for_asm (target);
4513 if (vnode == NULL)
4514 fnode = cgraph_node_for_asm (target);
4517 if (fnode)
4519 /* We can't mark function nodes as used after cgraph global info
4520 is finished. This wouldn't generally be necessary, but C++
4521 virtual table thunks are introduced late in the game and
4522 might seem like they need marking, although in fact they
4523 don't. */
4524 if (! cgraph_global_info_ready)
4525 cgraph_mark_needed_node (fnode);
4526 return fnode->decl;
4528 else if (vnode)
4530 cgraph_varpool_mark_needed_node (vnode);
4531 return vnode->decl;
4533 else
4534 return NULL_TREE;
4537 /* Output the assembler code for a define (equate) using ASM_OUTPUT_DEF
4538 or ASM_OUTPUT_DEF_FROM_DECLS. The function defines the symbol whose
4539 tree node is DECL to have the value of the tree node TARGET. */
4541 static void
4542 do_assemble_alias (tree decl, tree target)
4544 if (TREE_ASM_WRITTEN (decl))
4545 return;
4547 TREE_ASM_WRITTEN (decl) = 1;
4548 TREE_ASM_WRITTEN (DECL_ASSEMBLER_NAME (decl)) = 1;
4550 if (lookup_attribute ("weakref", DECL_ATTRIBUTES (decl)))
4552 ultimate_transparent_alias_target (&target);
4554 if (!TREE_SYMBOL_REFERENCED (target))
4555 weakref_targets = tree_cons (decl, target, weakref_targets);
4557 #ifdef ASM_OUTPUT_WEAKREF
4558 ASM_OUTPUT_WEAKREF (asm_out_file, decl,
4559 IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl)),
4560 IDENTIFIER_POINTER (target));
4561 #else
4562 if (!SUPPORTS_WEAK)
4564 error ("%Jweakref is not supported in this configuration", decl);
4565 return;
4567 #endif
4568 return;
4571 #ifdef ASM_OUTPUT_DEF
4572 /* Make name accessible from other files, if appropriate. */
4574 if (TREE_PUBLIC (decl))
4576 globalize_decl (decl);
4577 maybe_assemble_visibility (decl);
4580 # ifdef ASM_OUTPUT_DEF_FROM_DECLS
4581 ASM_OUTPUT_DEF_FROM_DECLS (asm_out_file, decl, target);
4582 # else
4583 ASM_OUTPUT_DEF (asm_out_file,
4584 IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl)),
4585 IDENTIFIER_POINTER (target));
4586 # endif
4587 #elif defined (ASM_OUTPUT_WEAK_ALIAS) || defined (ASM_WEAKEN_DECL)
4589 const char *name;
4590 tree *p, t;
4592 name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
4593 # ifdef ASM_WEAKEN_DECL
4594 ASM_WEAKEN_DECL (asm_out_file, decl, name, IDENTIFIER_POINTER (target));
4595 # else
4596 ASM_OUTPUT_WEAK_ALIAS (asm_out_file, name, IDENTIFIER_POINTER (target));
4597 # endif
4598 /* Remove this function from the pending weak list so that
4599 we do not emit multiple .weak directives for it. */
4600 for (p = &weak_decls; (t = *p) ; )
4601 if (DECL_ASSEMBLER_NAME (decl) == DECL_ASSEMBLER_NAME (TREE_VALUE (t)))
4602 *p = TREE_CHAIN (t);
4603 else
4604 p = &TREE_CHAIN (t);
4606 /* Remove weakrefs to the same target from the pending weakref
4607 list, for the same reason. */
4608 for (p = &weakref_targets; (t = *p) ; )
4610 if (DECL_ASSEMBLER_NAME (decl)
4611 == ultimate_transparent_alias_target (&TREE_VALUE (t)))
4612 *p = TREE_CHAIN (t);
4613 else
4614 p = &TREE_CHAIN (t);
4617 #endif
4620 /* First pass of completing pending aliases. Make sure that cgraph knows
4621 which symbols will be required. */
4623 void
4624 finish_aliases_1 (void)
4626 unsigned i;
4627 alias_pair *p;
4629 for (i = 0; VEC_iterate (alias_pair, alias_pairs, i, p); i++)
4631 tree target_decl;
4633 target_decl = find_decl_and_mark_needed (p->decl, p->target);
4634 if (target_decl == NULL)
4636 if (! lookup_attribute ("weakref", DECL_ATTRIBUTES (p->decl)))
4637 error ("%q+D aliased to undefined symbol %qs",
4638 p->decl, IDENTIFIER_POINTER (p->target));
4640 else if (DECL_EXTERNAL (target_decl)
4641 && ! lookup_attribute ("weakref", DECL_ATTRIBUTES (p->decl)))
4642 error ("%q+D aliased to external symbol %qs",
4643 p->decl, IDENTIFIER_POINTER (p->target));
4647 /* Second pass of completing pending aliases. Emit the actual assembly.
4648 This happens at the end of compilation and thus it is assured that the
4649 target symbol has been emitted. */
4651 void
4652 finish_aliases_2 (void)
4654 unsigned i;
4655 alias_pair *p;
4657 for (i = 0; VEC_iterate (alias_pair, alias_pairs, i, p); i++)
4658 do_assemble_alias (p->decl, p->target);
4660 VEC_truncate (alias_pair, alias_pairs, 0);
4663 /* Emit an assembler directive to make the symbol for DECL an alias to
4664 the symbol for TARGET. */
4666 void
4667 assemble_alias (tree decl, tree target)
4669 tree target_decl;
4670 bool is_weakref = false;
4672 if (lookup_attribute ("weakref", DECL_ATTRIBUTES (decl)))
4674 tree alias = DECL_ASSEMBLER_NAME (decl);
4676 is_weakref = true;
4678 ultimate_transparent_alias_target (&target);
4680 if (alias == target)
4681 error ("weakref %q+D ultimately targets itself", decl);
4682 else
4684 #ifndef ASM_OUTPUT_WEAKREF
4685 IDENTIFIER_TRANSPARENT_ALIAS (alias) = 1;
4686 TREE_CHAIN (alias) = target;
4687 #endif
4689 if (TREE_PUBLIC (decl))
4690 error ("weakref %q+D must have static linkage", decl);
4692 else
4694 #if !defined (ASM_OUTPUT_DEF)
4695 # if !defined(ASM_OUTPUT_WEAK_ALIAS) && !defined (ASM_WEAKEN_DECL)
4696 error ("%Jalias definitions not supported in this configuration", decl);
4697 return;
4698 # else
4699 if (!DECL_WEAK (decl))
4701 error ("%Jonly weak aliases are supported in this configuration", decl);
4702 return;
4704 # endif
4705 #endif
4708 /* We must force creation of DECL_RTL for debug info generation, even though
4709 we don't use it here. */
4710 make_decl_rtl (decl);
4711 TREE_USED (decl) = 1;
4713 /* A quirk of the initial implementation of aliases required that the user
4714 add "extern" to all of them. Which is silly, but now historical. Do
4715 note that the symbol is in fact locally defined. */
4716 if (! is_weakref)
4717 DECL_EXTERNAL (decl) = 0;
4719 /* Allow aliases to aliases. */
4720 if (TREE_CODE (decl) == FUNCTION_DECL)
4721 cgraph_node (decl)->alias = true;
4722 else
4723 cgraph_varpool_node (decl)->alias = true;
4725 /* If the target has already been emitted, we don't have to queue the
4726 alias. This saves a tad o memory. */
4727 target_decl = find_decl_and_mark_needed (decl, target);
4728 if (target_decl && TREE_ASM_WRITTEN (target_decl))
4729 do_assemble_alias (decl, target);
4730 else
4732 alias_pair *p = VEC_safe_push (alias_pair, gc, alias_pairs, NULL);
4733 p->decl = decl;
4734 p->target = target;
4738 /* Emit an assembler directive to set symbol for DECL visibility to
4739 the visibility type VIS, which must not be VISIBILITY_DEFAULT. */
4741 void
4742 default_assemble_visibility (tree decl, int vis)
4744 static const char * const visibility_types[] = {
4745 NULL, "internal", "hidden", "protected"
4748 const char *name, *type;
4750 name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
4751 type = visibility_types[vis];
4753 #ifdef HAVE_GAS_HIDDEN
4754 fprintf (asm_out_file, "\t.%s\t", type);
4755 assemble_name (asm_out_file, name);
4756 fprintf (asm_out_file, "\n");
4757 #else
4758 warning (OPT_Wattributes, "visibility attribute not supported "
4759 "in this configuration; ignored");
4760 #endif
4763 /* A helper function to call assemble_visibility when needed for a decl. */
4765 static void
4766 maybe_assemble_visibility (tree decl)
4768 enum symbol_visibility vis = DECL_VISIBILITY (decl);
4770 if (vis != VISIBILITY_DEFAULT)
4771 targetm.asm_out.visibility (decl, vis);
4774 /* Returns 1 if the target configuration supports defining public symbols
4775 so that one of them will be chosen at link time instead of generating a
4776 multiply-defined symbol error, whether through the use of weak symbols or
4777 a target-specific mechanism for having duplicates discarded. */
4780 supports_one_only (void)
4782 if (SUPPORTS_ONE_ONLY)
4783 return 1;
4784 return SUPPORTS_WEAK;
4787 /* Set up DECL as a public symbol that can be defined in multiple
4788 translation units without generating a linker error. */
4790 void
4791 make_decl_one_only (tree decl)
4793 gcc_assert (TREE_CODE (decl) == VAR_DECL
4794 || TREE_CODE (decl) == FUNCTION_DECL);
4796 TREE_PUBLIC (decl) = 1;
4798 if (SUPPORTS_ONE_ONLY)
4800 #ifdef MAKE_DECL_ONE_ONLY
4801 MAKE_DECL_ONE_ONLY (decl);
4802 #endif
4803 DECL_ONE_ONLY (decl) = 1;
4805 else if (TREE_CODE (decl) == VAR_DECL
4806 && (DECL_INITIAL (decl) == 0 || DECL_INITIAL (decl) == error_mark_node))
4807 DECL_COMMON (decl) = 1;
4808 else
4810 gcc_assert (SUPPORTS_WEAK);
4811 DECL_WEAK (decl) = 1;
4815 void
4816 init_varasm_once (void)
4818 section_htab = htab_create_ggc (31, section_entry_hash,
4819 section_entry_eq, NULL);
4820 const_desc_htab = htab_create_ggc (1009, const_desc_hash,
4821 const_desc_eq, NULL);
4823 const_alias_set = new_alias_set ();
4825 #ifdef TEXT_SECTION_ASM_OP
4826 text_section = get_unnamed_section (SECTION_CODE, output_section_asm_op,
4827 TEXT_SECTION_ASM_OP);
4828 #endif
4830 #ifdef DATA_SECTION_ASM_OP
4831 data_section = get_unnamed_section (SECTION_WRITE, output_section_asm_op,
4832 DATA_SECTION_ASM_OP);
4833 #endif
4835 #ifdef SDATA_SECTION_ASM_OP
4836 sdata_section = get_unnamed_section (SECTION_WRITE, output_section_asm_op,
4837 SDATA_SECTION_ASM_OP);
4838 #endif
4840 #ifdef READONLY_DATA_SECTION_ASM_OP
4841 readonly_data_section = get_unnamed_section (0, output_section_asm_op,
4842 READONLY_DATA_SECTION_ASM_OP);
4843 #endif
4845 #ifdef CTORS_SECTION_ASM_OP
4846 ctors_section = get_unnamed_section (0, output_section_asm_op,
4847 CTORS_SECTION_ASM_OP);
4848 #endif
4850 #ifdef DTORS_SECTION_ASM_OP
4851 dtors_section = get_unnamed_section (0, output_section_asm_op,
4852 DTORS_SECTION_ASM_OP);
4853 #endif
4855 #ifdef BSS_SECTION_ASM_OP
4856 bss_section = get_unnamed_section (SECTION_WRITE | SECTION_BSS,
4857 output_section_asm_op,
4858 BSS_SECTION_ASM_OP);
4859 #endif
4861 #ifdef SBSS_SECTION_ASM_OP
4862 sbss_section = get_unnamed_section (SECTION_WRITE | SECTION_BSS,
4863 output_section_asm_op,
4864 SBSS_SECTION_ASM_OP);
4865 #endif
4867 targetm.asm_out.init_sections ();
4869 if (readonly_data_section == NULL)
4870 readonly_data_section = text_section;
4873 enum tls_model
4874 decl_default_tls_model (tree decl)
4876 enum tls_model kind;
4877 bool is_local;
4879 is_local = targetm.binds_local_p (decl);
4880 if (!flag_shlib)
4882 if (is_local)
4883 kind = TLS_MODEL_LOCAL_EXEC;
4884 else
4885 kind = TLS_MODEL_INITIAL_EXEC;
4888 /* Local dynamic is inefficient when we're not combining the
4889 parts of the address. */
4890 else if (optimize && is_local)
4891 kind = TLS_MODEL_LOCAL_DYNAMIC;
4892 else
4893 kind = TLS_MODEL_GLOBAL_DYNAMIC;
4894 if (kind < flag_tls_default)
4895 kind = flag_tls_default;
4897 return kind;
4900 /* Select a set of attributes for section NAME based on the properties
4901 of DECL and whether or not RELOC indicates that DECL's initializer
4902 might contain runtime relocations.
4904 We make the section read-only and executable for a function decl,
4905 read-only for a const data decl, and writable for a non-const data decl. */
4907 unsigned int
4908 default_section_type_flags (tree decl, const char *name, int reloc)
4910 return default_section_type_flags_1 (decl, name, reloc, flag_pic);
4913 unsigned int
4914 default_section_type_flags_1 (tree decl, const char *name, int reloc,
4915 int shlib)
4917 unsigned int flags;
4919 if (decl && TREE_CODE (decl) == FUNCTION_DECL)
4920 flags = SECTION_CODE;
4921 else if (decl && decl_readonly_section_1 (decl, reloc, shlib))
4922 flags = 0;
4923 else if (current_function_decl
4924 && cfun
4925 && cfun->unlikely_text_section_name
4926 && strcmp (name, cfun->unlikely_text_section_name) == 0)
4927 flags = SECTION_CODE;
4928 else if (!decl
4929 && (!current_function_decl || !cfun)
4930 && strcmp (name, UNLIKELY_EXECUTED_TEXT_SECTION_NAME) == 0)
4931 flags = SECTION_CODE;
4932 else
4933 flags = SECTION_WRITE;
4935 if (decl && DECL_ONE_ONLY (decl))
4936 flags |= SECTION_LINKONCE;
4938 if (decl && TREE_CODE (decl) == VAR_DECL && DECL_THREAD_LOCAL_P (decl))
4939 flags |= SECTION_TLS | SECTION_WRITE;
4941 if (strcmp (name, ".bss") == 0
4942 || strncmp (name, ".bss.", 5) == 0
4943 || strncmp (name, ".gnu.linkonce.b.", 16) == 0
4944 || strcmp (name, ".sbss") == 0
4945 || strncmp (name, ".sbss.", 6) == 0
4946 || strncmp (name, ".gnu.linkonce.sb.", 17) == 0)
4947 flags |= SECTION_BSS;
4949 if (strcmp (name, ".tdata") == 0
4950 || strncmp (name, ".tdata.", 7) == 0
4951 || strncmp (name, ".gnu.linkonce.td.", 17) == 0)
4952 flags |= SECTION_TLS;
4954 if (strcmp (name, ".tbss") == 0
4955 || strncmp (name, ".tbss.", 6) == 0
4956 || strncmp (name, ".gnu.linkonce.tb.", 17) == 0)
4957 flags |= SECTION_TLS | SECTION_BSS;
4959 /* These three sections have special ELF types. They are neither
4960 SHT_PROGBITS nor SHT_NOBITS, so when changing sections we don't
4961 want to print a section type (@progbits or @nobits). If someone
4962 is silly enough to emit code or TLS variables to one of these
4963 sections, then don't handle them specially. */
4964 if (!(flags & (SECTION_CODE | SECTION_BSS | SECTION_TLS))
4965 && (strcmp (name, ".init_array") == 0
4966 || strcmp (name, ".fini_array") == 0
4967 || strcmp (name, ".preinit_array") == 0))
4968 flags |= SECTION_NOTYPE;
4970 return flags;
4973 /* Output assembly to switch to section NAME with attribute FLAGS.
4974 Four variants for common object file formats. */
4976 void
4977 default_no_named_section (const char *name ATTRIBUTE_UNUSED,
4978 unsigned int flags ATTRIBUTE_UNUSED,
4979 tree decl ATTRIBUTE_UNUSED)
4981 /* Some object formats don't support named sections at all. The
4982 front-end should already have flagged this as an error. */
4983 gcc_unreachable ();
4986 void
4987 default_elf_asm_named_section (const char *name, unsigned int flags,
4988 tree decl ATTRIBUTE_UNUSED)
4990 char flagchars[10], *f = flagchars;
4992 /* If we have already declared this section, we can use an
4993 abbreviated form to switch back to it -- unless this section is
4994 part of a COMDAT groups, in which case GAS requires the full
4995 declaration every time. */
4996 if (!(HAVE_COMDAT_GROUP && (flags & SECTION_LINKONCE))
4997 && (flags & SECTION_DECLARED))
4999 fprintf (asm_out_file, "\t.section\t%s\n", name);
5000 return;
5003 if (!(flags & SECTION_DEBUG))
5004 *f++ = 'a';
5005 if (flags & SECTION_WRITE)
5006 *f++ = 'w';
5007 if (flags & SECTION_CODE)
5008 *f++ = 'x';
5009 if (flags & SECTION_SMALL)
5010 *f++ = 's';
5011 if (flags & SECTION_MERGE)
5012 *f++ = 'M';
5013 if (flags & SECTION_STRINGS)
5014 *f++ = 'S';
5015 if (flags & SECTION_TLS)
5016 *f++ = 'T';
5017 if (HAVE_COMDAT_GROUP && (flags & SECTION_LINKONCE))
5018 *f++ = 'G';
5019 *f = '\0';
5021 fprintf (asm_out_file, "\t.section\t%s,\"%s\"", name, flagchars);
5023 if (!(flags & SECTION_NOTYPE))
5025 const char *type;
5026 const char *format;
5028 if (flags & SECTION_BSS)
5029 type = "nobits";
5030 else
5031 type = "progbits";
5033 format = ",@%s";
5034 #ifdef ASM_COMMENT_START
5035 /* On platforms that use "@" as the assembly comment character,
5036 use "%" instead. */
5037 if (strcmp (ASM_COMMENT_START, "@") == 0)
5038 format = ",%%%s";
5039 #endif
5040 fprintf (asm_out_file, format, type);
5042 if (flags & SECTION_ENTSIZE)
5043 fprintf (asm_out_file, ",%d", flags & SECTION_ENTSIZE);
5044 if (HAVE_COMDAT_GROUP && (flags & SECTION_LINKONCE))
5045 fprintf (asm_out_file, ",%s,comdat",
5046 lang_hooks.decls.comdat_group (decl));
5049 putc ('\n', asm_out_file);
5052 void
5053 default_coff_asm_named_section (const char *name, unsigned int flags,
5054 tree decl ATTRIBUTE_UNUSED)
5056 char flagchars[8], *f = flagchars;
5058 if (flags & SECTION_WRITE)
5059 *f++ = 'w';
5060 if (flags & SECTION_CODE)
5061 *f++ = 'x';
5062 *f = '\0';
5064 fprintf (asm_out_file, "\t.section\t%s,\"%s\"\n", name, flagchars);
5067 void
5068 default_pe_asm_named_section (const char *name, unsigned int flags,
5069 tree decl)
5071 default_coff_asm_named_section (name, flags, decl);
5073 if (flags & SECTION_LINKONCE)
5075 /* Functions may have been compiled at various levels of
5076 optimization so we can't use `same_size' here.
5077 Instead, have the linker pick one. */
5078 fprintf (asm_out_file, "\t.linkonce %s\n",
5079 (flags & SECTION_CODE ? "discard" : "same_size"));
5083 /* The lame default section selector. */
5085 section *
5086 default_select_section (tree decl, int reloc,
5087 unsigned HOST_WIDE_INT align ATTRIBUTE_UNUSED)
5089 if (DECL_P (decl))
5091 if (decl_readonly_section (decl, reloc))
5092 return readonly_data_section;
5094 else if (TREE_CODE (decl) == CONSTRUCTOR)
5096 if (! ((flag_pic && reloc)
5097 || !TREE_READONLY (decl)
5098 || TREE_SIDE_EFFECTS (decl)
5099 || !TREE_CONSTANT (decl)))
5100 return readonly_data_section;
5102 else if (TREE_CODE (decl) == STRING_CST)
5103 return readonly_data_section;
5104 else if (! (flag_pic && reloc))
5105 return readonly_data_section;
5107 return data_section;
5110 enum section_category
5111 categorize_decl_for_section (tree decl, int reloc, int shlib)
5113 enum section_category ret;
5115 if (TREE_CODE (decl) == FUNCTION_DECL)
5116 return SECCAT_TEXT;
5117 else if (TREE_CODE (decl) == STRING_CST)
5119 if (flag_mudflap) /* or !flag_merge_constants */
5120 return SECCAT_RODATA;
5121 else
5122 return SECCAT_RODATA_MERGE_STR;
5124 else if (TREE_CODE (decl) == VAR_DECL)
5126 if (DECL_INITIAL (decl) == NULL
5127 || DECL_INITIAL (decl) == error_mark_node
5128 || (flag_zero_initialized_in_bss
5129 /* Leave constant zeroes in .rodata so they can be shared. */
5130 && !TREE_READONLY (decl)
5131 && initializer_zerop (DECL_INITIAL (decl))))
5132 ret = SECCAT_BSS;
5133 else if (! TREE_READONLY (decl)
5134 || TREE_SIDE_EFFECTS (decl)
5135 || ! TREE_CONSTANT (DECL_INITIAL (decl)))
5137 if (shlib && (reloc & 2))
5138 ret = SECCAT_DATA_REL;
5139 else if (shlib && reloc)
5140 ret = SECCAT_DATA_REL_LOCAL;
5141 else
5142 ret = SECCAT_DATA;
5144 else if (shlib && (reloc & 2))
5145 ret = SECCAT_DATA_REL_RO;
5146 else if (shlib && reloc)
5147 ret = SECCAT_DATA_REL_RO_LOCAL;
5148 else if (reloc || flag_merge_constants < 2)
5149 /* C and C++ don't allow different variables to share the same
5150 location. -fmerge-all-constants allows even that (at the
5151 expense of not conforming). */
5152 ret = SECCAT_RODATA;
5153 else if (TREE_CODE (DECL_INITIAL (decl)) == STRING_CST)
5154 ret = SECCAT_RODATA_MERGE_STR_INIT;
5155 else
5156 ret = SECCAT_RODATA_MERGE_CONST;
5158 else if (TREE_CODE (decl) == CONSTRUCTOR)
5160 if ((shlib && reloc)
5161 || TREE_SIDE_EFFECTS (decl)
5162 || ! TREE_CONSTANT (decl))
5163 ret = SECCAT_DATA;
5164 else
5165 ret = SECCAT_RODATA;
5167 else
5168 ret = SECCAT_RODATA;
5170 /* There are no read-only thread-local sections. */
5171 if (TREE_CODE (decl) == VAR_DECL && DECL_THREAD_LOCAL_P (decl))
5173 /* Note that this would be *just* SECCAT_BSS, except that there's
5174 no concept of a read-only thread-local-data section. */
5175 if (ret == SECCAT_BSS
5176 || (flag_zero_initialized_in_bss
5177 && initializer_zerop (DECL_INITIAL (decl))))
5178 ret = SECCAT_TBSS;
5179 else
5180 ret = SECCAT_TDATA;
5183 /* If the target uses small data sections, select it. */
5184 else if (targetm.in_small_data_p (decl))
5186 if (ret == SECCAT_BSS)
5187 ret = SECCAT_SBSS;
5188 else if (targetm.have_srodata_section && ret == SECCAT_RODATA)
5189 ret = SECCAT_SRODATA;
5190 else
5191 ret = SECCAT_SDATA;
5194 return ret;
5197 bool
5198 decl_readonly_section (tree decl, int reloc)
5200 return decl_readonly_section_1 (decl, reloc, flag_pic);
5203 bool
5204 decl_readonly_section_1 (tree decl, int reloc, int shlib)
5206 switch (categorize_decl_for_section (decl, reloc, shlib))
5208 case SECCAT_RODATA:
5209 case SECCAT_RODATA_MERGE_STR:
5210 case SECCAT_RODATA_MERGE_STR_INIT:
5211 case SECCAT_RODATA_MERGE_CONST:
5212 case SECCAT_SRODATA:
5213 return true;
5214 break;
5215 default:
5216 return false;
5217 break;
5221 /* Select a section based on the above categorization. */
5223 section *
5224 default_elf_select_section (tree decl, int reloc,
5225 unsigned HOST_WIDE_INT align)
5227 return default_elf_select_section_1 (decl, reloc, align, flag_pic);
5230 section *
5231 default_elf_select_section_1 (tree decl, int reloc,
5232 unsigned HOST_WIDE_INT align, int shlib)
5234 const char *sname;
5235 switch (categorize_decl_for_section (decl, reloc, shlib))
5237 case SECCAT_TEXT:
5238 /* We're not supposed to be called on FUNCTION_DECLs. */
5239 gcc_unreachable ();
5240 case SECCAT_RODATA:
5241 return readonly_data_section;
5242 case SECCAT_RODATA_MERGE_STR:
5243 return mergeable_string_section (decl, align, 0);
5244 case SECCAT_RODATA_MERGE_STR_INIT:
5245 return mergeable_string_section (DECL_INITIAL (decl), align, 0);
5246 case SECCAT_RODATA_MERGE_CONST:
5247 return mergeable_constant_section (DECL_MODE (decl), align, 0);
5248 case SECCAT_SRODATA:
5249 sname = ".sdata2";
5250 break;
5251 case SECCAT_DATA:
5252 return data_section;
5253 case SECCAT_DATA_REL:
5254 sname = ".data.rel";
5255 break;
5256 case SECCAT_DATA_REL_LOCAL:
5257 sname = ".data.rel.local";
5258 break;
5259 case SECCAT_DATA_REL_RO:
5260 sname = ".data.rel.ro";
5261 break;
5262 case SECCAT_DATA_REL_RO_LOCAL:
5263 sname = ".data.rel.ro.local";
5264 break;
5265 case SECCAT_SDATA:
5266 sname = ".sdata";
5267 break;
5268 case SECCAT_TDATA:
5269 sname = ".tdata";
5270 break;
5271 case SECCAT_BSS:
5272 if (bss_section)
5273 return bss_section;
5274 sname = ".bss";
5275 break;
5276 case SECCAT_SBSS:
5277 sname = ".sbss";
5278 break;
5279 case SECCAT_TBSS:
5280 sname = ".tbss";
5281 break;
5282 default:
5283 gcc_unreachable ();
5286 if (!DECL_P (decl))
5287 decl = NULL_TREE;
5288 return get_named_section (decl, sname, reloc);
5291 /* Construct a unique section name based on the decl name and the
5292 categorization performed above. */
5294 void
5295 default_unique_section (tree decl, int reloc)
5297 default_unique_section_1 (decl, reloc, flag_pic);
5300 void
5301 default_unique_section_1 (tree decl, int reloc, int shlib)
5303 /* We only need to use .gnu.linkonce if we don't have COMDAT groups. */
5304 bool one_only = DECL_ONE_ONLY (decl) && !HAVE_COMDAT_GROUP;
5305 const char *prefix, *name;
5306 size_t nlen, plen;
5307 char *string;
5309 switch (categorize_decl_for_section (decl, reloc, shlib))
5311 case SECCAT_TEXT:
5312 prefix = one_only ? ".gnu.linkonce.t." : ".text.";
5313 break;
5314 case SECCAT_RODATA:
5315 case SECCAT_RODATA_MERGE_STR:
5316 case SECCAT_RODATA_MERGE_STR_INIT:
5317 case SECCAT_RODATA_MERGE_CONST:
5318 prefix = one_only ? ".gnu.linkonce.r." : ".rodata.";
5319 break;
5320 case SECCAT_SRODATA:
5321 prefix = one_only ? ".gnu.linkonce.s2." : ".sdata2.";
5322 break;
5323 case SECCAT_DATA:
5324 prefix = one_only ? ".gnu.linkonce.d." : ".data.";
5325 break;
5326 case SECCAT_DATA_REL:
5327 prefix = one_only ? ".gnu.linkonce.d.rel." : ".data.rel.";
5328 break;
5329 case SECCAT_DATA_REL_LOCAL:
5330 prefix = one_only ? ".gnu.linkonce.d.rel.local." : ".data.rel.local.";
5331 break;
5332 case SECCAT_DATA_REL_RO:
5333 prefix = one_only ? ".gnu.linkonce.d.rel.ro." : ".data.rel.ro.";
5334 break;
5335 case SECCAT_DATA_REL_RO_LOCAL:
5336 prefix = one_only ? ".gnu.linkonce.d.rel.ro.local."
5337 : ".data.rel.ro.local.";
5338 break;
5339 case SECCAT_SDATA:
5340 prefix = one_only ? ".gnu.linkonce.s." : ".sdata.";
5341 break;
5342 case SECCAT_BSS:
5343 prefix = one_only ? ".gnu.linkonce.b." : ".bss.";
5344 break;
5345 case SECCAT_SBSS:
5346 prefix = one_only ? ".gnu.linkonce.sb." : ".sbss.";
5347 break;
5348 case SECCAT_TDATA:
5349 prefix = one_only ? ".gnu.linkonce.td." : ".tdata.";
5350 break;
5351 case SECCAT_TBSS:
5352 prefix = one_only ? ".gnu.linkonce.tb." : ".tbss.";
5353 break;
5354 default:
5355 gcc_unreachable ();
5357 plen = strlen (prefix);
5359 name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
5360 name = targetm.strip_name_encoding (name);
5361 nlen = strlen (name);
5363 string = alloca (nlen + plen + 1);
5364 memcpy (string, prefix, plen);
5365 memcpy (string + plen, name, nlen + 1);
5367 DECL_SECTION_NAME (decl) = build_string (nlen + plen, string);
5370 section *
5371 default_select_rtx_section (enum machine_mode mode ATTRIBUTE_UNUSED,
5372 rtx x,
5373 unsigned HOST_WIDE_INT align ATTRIBUTE_UNUSED)
5375 if (flag_pic)
5376 switch (GET_CODE (x))
5378 case CONST:
5379 case SYMBOL_REF:
5380 case LABEL_REF:
5381 return data_section;
5383 default:
5384 break;
5387 return readonly_data_section;
5390 section *
5391 default_elf_select_rtx_section (enum machine_mode mode, rtx x,
5392 unsigned HOST_WIDE_INT align)
5394 /* ??? Handle small data here somehow. */
5396 if (flag_pic)
5397 switch (GET_CODE (x))
5399 case CONST:
5400 case SYMBOL_REF:
5401 return get_named_section (NULL, ".data.rel.ro", 3);
5403 case LABEL_REF:
5404 return get_named_section (NULL, ".data.rel.ro.local", 1);
5406 default:
5407 break;
5410 return mergeable_constant_section (mode, align, 0);
5413 /* Set the generally applicable flags on the SYMBOL_REF for EXP. */
5415 void
5416 default_encode_section_info (tree decl, rtx rtl, int first ATTRIBUTE_UNUSED)
5418 rtx symbol;
5419 int flags;
5421 /* Careful not to prod global register variables. */
5422 if (!MEM_P (rtl))
5423 return;
5424 symbol = XEXP (rtl, 0);
5425 if (GET_CODE (symbol) != SYMBOL_REF)
5426 return;
5428 flags = 0;
5429 if (TREE_CODE (decl) == FUNCTION_DECL)
5430 flags |= SYMBOL_FLAG_FUNCTION;
5431 if (targetm.binds_local_p (decl))
5432 flags |= SYMBOL_FLAG_LOCAL;
5433 if (TREE_CODE (decl) == VAR_DECL && DECL_THREAD_LOCAL_P (decl))
5434 flags |= DECL_TLS_MODEL (decl) << SYMBOL_FLAG_TLS_SHIFT;
5435 else if (targetm.in_small_data_p (decl))
5436 flags |= SYMBOL_FLAG_SMALL;
5437 /* ??? Why is DECL_EXTERNAL ever set for non-PUBLIC names? Without
5438 being PUBLIC, the thing *must* be defined in this translation unit.
5439 Prevent this buglet from being propagated into rtl code as well. */
5440 if (DECL_P (decl) && DECL_EXTERNAL (decl) && TREE_PUBLIC (decl))
5441 flags |= SYMBOL_FLAG_EXTERNAL;
5443 SYMBOL_REF_FLAGS (symbol) = flags;
5446 /* By default, we do nothing for encode_section_info, so we need not
5447 do anything but discard the '*' marker. */
5449 const char *
5450 default_strip_name_encoding (const char *str)
5452 return str + (*str == '*');
5455 /* Assume ELF-ish defaults, since that's pretty much the most liberal
5456 wrt cross-module name binding. */
5458 bool
5459 default_binds_local_p (tree exp)
5461 return default_binds_local_p_1 (exp, flag_shlib);
5464 bool
5465 default_binds_local_p_1 (tree exp, int shlib)
5467 bool local_p;
5469 /* A non-decl is an entry in the constant pool. */
5470 if (!DECL_P (exp))
5471 local_p = true;
5472 /* Weakrefs may not bind locally, even though the weakref itself is
5473 always static and therefore local. */
5474 else if (lookup_attribute ("weakref", DECL_ATTRIBUTES (exp)))
5475 local_p = false;
5476 /* Static variables are always local. */
5477 else if (! TREE_PUBLIC (exp))
5478 local_p = true;
5479 /* A variable is local if the user has said explicitly that it will
5480 be. */
5481 else if (DECL_VISIBILITY_SPECIFIED (exp)
5482 && DECL_VISIBILITY (exp) != VISIBILITY_DEFAULT)
5483 local_p = true;
5484 /* Variables defined outside this object might not be local. */
5485 else if (DECL_EXTERNAL (exp))
5486 local_p = false;
5487 /* If defined in this object and visibility is not default, must be
5488 local. */
5489 else if (DECL_VISIBILITY (exp) != VISIBILITY_DEFAULT)
5490 local_p = true;
5491 /* Default visibility weak data can be overridden by a strong symbol
5492 in another module and so are not local. */
5493 else if (DECL_WEAK (exp))
5494 local_p = false;
5495 /* If PIC, then assume that any global name can be overridden by
5496 symbols resolved from other modules. */
5497 else if (shlib)
5498 local_p = false;
5499 /* Uninitialized COMMON variable may be unified with symbols
5500 resolved from other modules. */
5501 else if (DECL_COMMON (exp)
5502 && (DECL_INITIAL (exp) == NULL
5503 || DECL_INITIAL (exp) == error_mark_node))
5504 local_p = false;
5505 /* Otherwise we're left with initialized (or non-common) global data
5506 which is of necessity defined locally. */
5507 else
5508 local_p = true;
5510 return local_p;
5513 /* Determine whether or not a pointer mode is valid. Assume defaults
5514 of ptr_mode or Pmode - can be overridden. */
5515 bool
5516 default_valid_pointer_mode (enum machine_mode mode)
5518 return (mode == ptr_mode || mode == Pmode);
5521 /* Default function to output code that will globalize a label. A
5522 target must define GLOBAL_ASM_OP or provide its own function to
5523 globalize a label. */
5524 #ifdef GLOBAL_ASM_OP
5525 void
5526 default_globalize_label (FILE * stream, const char *name)
5528 fputs (GLOBAL_ASM_OP, stream);
5529 assemble_name (stream, name);
5530 putc ('\n', stream);
5532 #endif /* GLOBAL_ASM_OP */
5534 /* Default function to output a label for unwind information. The
5535 default is to do nothing. A target that needs nonlocal labels for
5536 unwind information must provide its own function to do this. */
5537 void
5538 default_emit_unwind_label (FILE * stream ATTRIBUTE_UNUSED,
5539 tree decl ATTRIBUTE_UNUSED,
5540 int for_eh ATTRIBUTE_UNUSED,
5541 int empty ATTRIBUTE_UNUSED)
5545 /* This is how to output an internal numbered label where PREFIX is
5546 the class of label and LABELNO is the number within the class. */
5548 void
5549 default_internal_label (FILE *stream, const char *prefix,
5550 unsigned long labelno)
5552 char *const buf = alloca (40 + strlen (prefix));
5553 ASM_GENERATE_INTERNAL_LABEL (buf, prefix, labelno);
5554 ASM_OUTPUT_INTERNAL_LABEL (stream, buf);
5557 /* This is the default behavior at the beginning of a file. It's
5558 controlled by two other target-hook toggles. */
5559 void
5560 default_file_start (void)
5562 if (targetm.file_start_app_off && !flag_verbose_asm)
5563 fputs (ASM_APP_OFF, asm_out_file);
5565 if (targetm.file_start_file_directive)
5566 output_file_directive (asm_out_file, main_input_filename);
5569 /* This is a generic routine suitable for use as TARGET_ASM_FILE_END
5570 which emits a special section directive used to indicate whether or
5571 not this object file needs an executable stack. This is primarily
5572 a GNU extension to ELF but could be used on other targets. */
5574 int trampolines_created;
5576 void
5577 file_end_indicate_exec_stack (void)
5579 unsigned int flags = SECTION_DEBUG;
5580 if (trampolines_created)
5581 flags |= SECTION_CODE;
5583 switch_to_section (get_section (".note.GNU-stack", flags, NULL));
5586 /* Output DIRECTIVE (a C string) followed by a newline. This is used as
5587 a get_unnamed_section callback. */
5589 void
5590 output_section_asm_op (const void *directive)
5592 fprintf (asm_out_file, "%s\n", (const char *) directive);
5595 /* Emit assembly code to switch to section NEW_SECTION. Do nothing if
5596 the current section is NEW_SECTION. */
5598 void
5599 switch_to_section (section *new_section)
5601 if (in_section == new_section)
5602 return;
5604 if (new_section->common.flags & SECTION_FORGET)
5605 in_section = NULL;
5606 else
5607 in_section = new_section;
5609 if (new_section->common.flags & SECTION_NAMED)
5611 if (cfun
5612 && !cfun->unlikely_text_section_name
5613 && strcmp (new_section->named.name,
5614 UNLIKELY_EXECUTED_TEXT_SECTION_NAME) == 0)
5615 cfun->unlikely_text_section_name = UNLIKELY_EXECUTED_TEXT_SECTION_NAME;
5617 targetm.asm_out.named_section (new_section->named.name,
5618 new_section->named.common.flags,
5619 new_section->named.decl);
5621 else
5622 new_section->unnamed.callback (new_section->unnamed.data);
5624 new_section->common.flags |= SECTION_DECLARED;
5627 #include "gt-varasm.h"