Fix problems with labels with hot/cold partitioning.
[official-gcc.git] / gcc / varasm.c
bloba1859836a0a065031bb4aea11da6a962343e7932
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, 59 Temple Place - Suite 330, Boston, MA
21 02111-1307, 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 const char *first_global_object_name;
64 const char *weak_global_object_name;
66 struct addr_const;
67 struct constant_descriptor_rtx;
68 struct rtx_constant_pool;
70 struct varasm_status GTY(())
72 /* If we're using a per-function constant pool, this is it. */
73 struct rtx_constant_pool *pool;
75 /* Number of tree-constants deferred during the expansion of this
76 function. */
77 unsigned int deferred_constants;
80 #define n_deferred_constants (cfun->varasm->deferred_constants)
82 /* Number for making the label on the next
83 constant that is stored in memory. */
85 static GTY(()) int const_labelno;
87 /* Carry information from ASM_DECLARE_OBJECT_NAME
88 to ASM_FINISH_DECLARE_OBJECT. */
90 int size_directive_output;
92 /* The last decl for which assemble_variable was called,
93 if it did ASM_DECLARE_OBJECT_NAME.
94 If the last call to assemble_variable didn't do that,
95 this holds 0. */
97 tree last_assemble_variable_decl;
99 /* The following global variable indicates if the first basic block
100 in a function belongs to the cold partition or not. */
102 bool first_function_block_is_cold;
104 /* We give all constants their own alias set. Perhaps redundant with
105 MEM_READONLY_P, but pre-dates it. */
107 static HOST_WIDE_INT const_alias_set;
109 static const char *strip_reg_name (const char *);
110 static int contains_pointers_p (tree);
111 #ifdef ASM_OUTPUT_EXTERNAL
112 static bool incorporeal_function_p (tree);
113 #endif
114 static void decode_addr_const (tree, struct addr_const *);
115 static hashval_t const_desc_hash (const void *);
116 static int const_desc_eq (const void *, const void *);
117 static hashval_t const_hash_1 (const tree);
118 static int compare_constant (const tree, const tree);
119 static tree copy_constant (tree);
120 static void output_constant_def_contents (rtx);
121 static void output_addressed_constants (tree);
122 static unsigned HOST_WIDE_INT array_size_for_constructor (tree);
123 static unsigned min_align (unsigned, unsigned);
124 static void output_constructor (tree, unsigned HOST_WIDE_INT, unsigned int);
125 static void globalize_decl (tree);
126 static void maybe_assemble_visibility (tree);
127 static int in_named_entry_eq (const void *, const void *);
128 static hashval_t in_named_entry_hash (const void *);
129 static void initialize_cold_section_name (void);
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 static GTY(()) enum in_section in_section = no_section;
147 enum in_section last_text_section;
149 /* Return a nonzero value if DECL has a section attribute. */
150 #ifndef IN_NAMED_SECTION
151 #define IN_NAMED_SECTION(DECL) \
152 ((TREE_CODE (DECL) == FUNCTION_DECL || TREE_CODE (DECL) == VAR_DECL) \
153 && DECL_SECTION_NAME (DECL) != NULL_TREE)
154 #endif
156 /* Text of section name when in_section == in_named. */
157 static GTY(()) const char *in_named_name;
158 const char *last_text_section_name;
160 /* Hash table of flags that have been used for a particular named section. */
162 struct in_named_entry GTY(())
164 const char *name;
165 unsigned int flags;
166 bool declared;
169 static GTY((param_is (struct in_named_entry))) htab_t in_named_htab;
171 /* Define functions like text_section for any extra sections. */
172 #ifdef EXTRA_SECTION_FUNCTIONS
173 EXTRA_SECTION_FUNCTIONS
174 #endif
176 static void
177 initialize_cold_section_name (void)
179 const char *name;
180 const char *stripped_name;
181 char *buffer;
182 int len;
183 struct function *cfun;
185 if (current_function_decl)
187 cfun = DECL_STRUCT_FUNCTION (current_function_decl);
188 if (!cfun->unlikely_text_section_name)
190 if (flag_function_sections
191 && DECL_SECTION_NAME (current_function_decl))
193 name = xstrdup (TREE_STRING_POINTER (DECL_SECTION_NAME
194 (current_function_decl)));
195 stripped_name = targetm.strip_name_encoding (name);
196 len = strlen (stripped_name);
197 buffer = (char *) xmalloc (len + 10);
198 sprintf (buffer, "%s%s", stripped_name, "_unlikely");
199 cfun->unlikely_text_section_name = ggc_strdup (buffer);
200 free (buffer);
201 free ((char *) name);
203 else
204 cfun->unlikely_text_section_name =
205 UNLIKELY_EXECUTED_TEXT_SECTION_NAME;
208 else
209 internal_error
210 ("initialize_cold_section_name called without valid current_function_decl.");
213 /* Tell assembler to switch to text section. */
215 void
216 text_section (void)
218 if (in_section != in_text)
220 in_section = in_text;
221 last_text_section = in_text;
222 fprintf (asm_out_file, "%s\n", TEXT_SECTION_ASM_OP);
226 /* Tell assembler to switch to unlikely-to-be-executed text section. */
228 void
229 unlikely_text_section (void)
231 if (current_function_decl)
233 struct function *cfun = DECL_STRUCT_FUNCTION (current_function_decl);
235 if (!cfun->unlikely_text_section_name)
236 initialize_cold_section_name ();
238 if ((in_section != in_unlikely_executed_text)
239 && (in_section != in_named
240 || strcmp (in_named_name, cfun->unlikely_text_section_name) != 0))
242 named_section (NULL_TREE, cfun->unlikely_text_section_name, 0);
243 in_section = in_unlikely_executed_text;
244 last_text_section = in_unlikely_executed_text;
247 else
249 named_section (NULL_TREE, UNLIKELY_EXECUTED_TEXT_SECTION_NAME, 0);
250 in_section = in_unlikely_executed_text;
251 last_text_section = in_unlikely_executed_text;
255 /* Tell assembler to switch to data section. */
257 void
258 data_section (void)
260 if (in_section != in_data)
262 in_section = in_data;
263 fprintf (asm_out_file, "%s\n", DATA_SECTION_ASM_OP);
267 /* Tell assembler to switch to read-only data section. This is normally
268 the text section. */
270 void
271 readonly_data_section (void)
273 #ifdef READONLY_DATA_SECTION
274 READONLY_DATA_SECTION (); /* Note this can call data_section. */
275 #else
276 #ifdef READONLY_DATA_SECTION_ASM_OP
277 if (in_section != in_readonly_data)
279 in_section = in_readonly_data;
280 fputs (READONLY_DATA_SECTION_ASM_OP, asm_out_file);
281 fputc ('\n', asm_out_file);
283 #else
284 text_section ();
285 #endif
286 #endif
289 /* Determine if we're in the text section. */
292 in_text_section (void)
294 return in_section == in_text;
297 /* Determine if we're in the unlikely-to-be-executed text section. */
300 in_unlikely_text_section (void)
302 bool ret_val;
303 struct function *cfun;
305 if (current_function_decl)
307 cfun = DECL_STRUCT_FUNCTION (current_function_decl);
309 ret_val = ((in_section == in_unlikely_executed_text)
310 || (in_section == in_named
311 && cfun->unlikely_text_section_name
312 && strcmp (in_named_name,
313 cfun->unlikely_text_section_name) == 0));
315 else
317 ret_val = ((in_section == in_unlikely_executed_text)
318 || (in_section == in_named
319 && strcmp (in_named_name,
320 UNLIKELY_EXECUTED_TEXT_SECTION_NAME) == 0));
323 return ret_val;
326 /* Determine if we're in the data section. */
329 in_data_section (void)
331 return in_section == in_data;
334 /* Helper routines for maintaining in_named_htab. */
336 static int
337 in_named_entry_eq (const void *p1, const void *p2)
339 const struct in_named_entry *old = p1;
340 const char *new = p2;
342 return strcmp (old->name, new) == 0;
345 static hashval_t
346 in_named_entry_hash (const void *p)
348 const struct in_named_entry *old = p;
349 return htab_hash_string (old->name);
352 /* If SECTION has been seen before as a named section, return the flags
353 that were used. Otherwise, return 0. Note, that 0 is a perfectly valid
354 set of flags for a section to have, so 0 does not mean that the section
355 has not been seen. */
357 static unsigned int
358 get_named_section_flags (const char *section)
360 struct in_named_entry **slot;
362 slot = (struct in_named_entry **)
363 htab_find_slot_with_hash (in_named_htab, section,
364 htab_hash_string (section), NO_INSERT);
366 return slot ? (*slot)->flags : 0;
369 /* Returns true if the section has been declared before. Sets internal
370 flag on this section in in_named_hash so subsequent calls on this
371 section will return false. */
373 bool
374 named_section_first_declaration (const char *name)
376 struct in_named_entry **slot;
378 slot = (struct in_named_entry **)
379 htab_find_slot_with_hash (in_named_htab, name,
380 htab_hash_string (name), NO_INSERT);
381 if (! (*slot)->declared)
383 (*slot)->declared = true;
384 return true;
386 else
388 return false;
393 /* Record FLAGS for SECTION. If SECTION was previously recorded with a
394 different set of flags, return false. */
396 bool
397 set_named_section_flags (const char *section, unsigned int flags)
399 struct in_named_entry **slot, *entry;
401 slot = (struct in_named_entry **)
402 htab_find_slot_with_hash (in_named_htab, section,
403 htab_hash_string (section), INSERT);
404 entry = *slot;
406 if (!entry)
408 entry = ggc_alloc (sizeof (*entry));
409 *slot = entry;
410 entry->name = ggc_strdup (section);
411 entry->flags = flags;
412 entry->declared = false;
414 else if (entry->flags != flags)
415 return false;
417 return true;
420 /* Tell assembler to change to section NAME with attributes FLAGS. If
421 DECL is non-NULL, it is the VAR_DECL or FUNCTION_DECL with which
422 this section is associated. */
424 void
425 named_section_real (const char *name, unsigned int flags, tree decl)
427 if (in_section != in_named || strcmp (name, in_named_name) != 0)
429 bool unchanged = set_named_section_flags (name, flags);
431 gcc_assert (unchanged);
433 targetm.asm_out.named_section (name, flags, decl);
435 if (flags & SECTION_FORGET)
436 in_section = no_section;
437 else
439 in_named_name = ggc_strdup (name);
440 in_section = in_named;
444 if (in_text_section () || in_unlikely_text_section ())
446 last_text_section = in_section;
447 last_text_section_name = name;
451 /* Tell assembler to change to section NAME for DECL.
452 If DECL is NULL, just switch to section NAME.
453 If NAME is NULL, get the name from DECL.
454 If RELOC is 1, the initializer for DECL contains relocs. */
456 void
457 named_section (tree decl, const char *name, int reloc)
459 unsigned int flags;
461 gcc_assert (!decl || DECL_P (decl));
462 if (name == NULL)
463 name = TREE_STRING_POINTER (DECL_SECTION_NAME (decl));
465 if (strcmp (name, UNLIKELY_EXECUTED_TEXT_SECTION_NAME) == 0
466 && current_function_decl
467 && !(DECL_STRUCT_FUNCTION (current_function_decl))->unlikely_text_section_name)
469 struct function *cfun = DECL_STRUCT_FUNCTION (current_function_decl);
470 cfun->unlikely_text_section_name = UNLIKELY_EXECUTED_TEXT_SECTION_NAME;
473 flags = targetm.section_type_flags (decl, name, reloc);
475 /* Sanity check user variables for flag changes. Non-user
476 section flag changes will abort in named_section_flags.
477 However, don't complain if SECTION_OVERRIDE is set.
478 We trust that the setter knows that it is safe to ignore
479 the default flags for this decl. */
480 if (decl && ! set_named_section_flags (name, flags))
482 flags = get_named_section_flags (name);
483 if ((flags & SECTION_OVERRIDE) == 0)
484 error ("%J%D causes a section type conflict", decl, decl);
487 named_section_real (name, flags, decl);
490 /* If required, set DECL_SECTION_NAME to a unique name. */
492 void
493 resolve_unique_section (tree decl, int reloc ATTRIBUTE_UNUSED,
494 int flag_function_or_data_sections)
496 if (DECL_SECTION_NAME (decl) == NULL_TREE
497 && targetm.have_named_sections
498 && (flag_function_or_data_sections
499 || DECL_ONE_ONLY (decl)))
500 targetm.asm_out.unique_section (decl, reloc);
503 #ifdef BSS_SECTION_ASM_OP
505 /* Tell the assembler to switch to the bss section. */
507 void
508 bss_section (void)
510 if (in_section != in_bss)
512 fprintf (asm_out_file, "%s\n", BSS_SECTION_ASM_OP);
513 in_section = in_bss;
517 #ifdef ASM_OUTPUT_BSS
519 /* Utility function for ASM_OUTPUT_BSS for targets to use if
520 they don't support alignments in .bss.
521 ??? It is believed that this function will work in most cases so such
522 support is localized here. */
524 static void
525 asm_output_bss (FILE *file, tree decl ATTRIBUTE_UNUSED,
526 const char *name,
527 unsigned HOST_WIDE_INT size ATTRIBUTE_UNUSED,
528 unsigned HOST_WIDE_INT rounded)
530 targetm.asm_out.globalize_label (file, name);
531 bss_section ();
532 #ifdef ASM_DECLARE_OBJECT_NAME
533 last_assemble_variable_decl = decl;
534 ASM_DECLARE_OBJECT_NAME (file, name, decl);
535 #else
536 /* Standard thing is just output label for the object. */
537 ASM_OUTPUT_LABEL (file, name);
538 #endif /* ASM_DECLARE_OBJECT_NAME */
539 ASM_OUTPUT_SKIP (file, rounded ? rounded : 1);
542 #endif
544 #ifdef ASM_OUTPUT_ALIGNED_BSS
546 /* Utility function for targets to use in implementing
547 ASM_OUTPUT_ALIGNED_BSS.
548 ??? It is believed that this function will work in most cases so such
549 support is localized here. */
551 static void
552 asm_output_aligned_bss (FILE *file, tree decl ATTRIBUTE_UNUSED,
553 const char *name, unsigned HOST_WIDE_INT size,
554 int align)
556 bss_section ();
557 ASM_OUTPUT_ALIGN (file, floor_log2 (align / BITS_PER_UNIT));
558 #ifdef ASM_DECLARE_OBJECT_NAME
559 last_assemble_variable_decl = decl;
560 ASM_DECLARE_OBJECT_NAME (file, name, decl);
561 #else
562 /* Standard thing is just output label for the object. */
563 ASM_OUTPUT_LABEL (file, name);
564 #endif /* ASM_DECLARE_OBJECT_NAME */
565 ASM_OUTPUT_SKIP (file, size ? size : 1);
568 #endif
570 #endif /* BSS_SECTION_ASM_OP */
572 /* Switch to the section for function DECL.
574 If DECL is NULL_TREE, switch to the text section. We can be passed
575 NULL_TREE under some circumstances by dbxout.c at least. */
577 void
578 function_section (tree decl)
580 int reloc = 0;
582 if (first_function_block_is_cold)
583 reloc = 1;
585 #ifdef USE_SELECT_SECTION_FOR_FUNCTIONS
586 targetm.asm_out.select_section (decl, reloc, DECL_ALIGN (decl));
587 #else
588 if (decl != NULL_TREE
589 && DECL_SECTION_NAME (decl) != NULL_TREE
590 && targetm.have_named_sections)
591 named_section (decl, (char *) 0, 0);
592 else
593 text_section ();
594 #endif
597 void
598 current_function_section (tree decl)
600 #ifdef USE_SELECT_SECTION_FOR_FUNCTIONS
601 int reloc = 0;
603 if (in_unlikely_text_section ()
604 || last_text_section == in_unlikely_executed_text)
605 reloc = 1;
607 targetm.asm_out.select_section (decl, reloc, DECL_ALIGN (decl));
608 #else
609 if (last_text_section == in_unlikely_executed_text)
610 unlikely_text_section ();
611 else if (last_text_section == in_text)
612 text_section ();
613 else if (last_text_section == in_named
614 && targetm.have_named_sections)
615 named_section (NULL_TREE, last_text_section_name, 0);
616 else
617 function_section (decl);
618 #endif
621 /* Switch to read-only data section associated with function DECL. */
623 void
624 default_function_rodata_section (tree decl)
626 if (decl != NULL_TREE && DECL_SECTION_NAME (decl))
628 const char *name = TREE_STRING_POINTER (DECL_SECTION_NAME (decl));
630 /* For .gnu.linkonce.t.foo we want to use .gnu.linkonce.r.foo. */
631 if (DECL_ONE_ONLY (decl) && strncmp (name, ".gnu.linkonce.t.", 16) == 0)
633 size_t len = strlen (name) + 1;
634 char *rname = alloca (len);
636 memcpy (rname, name, len);
637 rname[14] = 'r';
638 named_section_real (rname, SECTION_LINKONCE, decl);
639 return;
641 /* For .text.foo we want to use .rodata.foo. */
642 else if (flag_function_sections && flag_data_sections
643 && strncmp (name, ".text.", 6) == 0)
645 size_t len = strlen (name) + 1;
646 char *rname = alloca (len + 2);
648 memcpy (rname, ".rodata", 7);
649 memcpy (rname + 7, name + 5, len - 5);
650 named_section_flags (rname, 0);
651 return;
655 readonly_data_section ();
658 /* Switch to read-only data section associated with function DECL
659 for targets where that section should be always the single
660 readonly data section. */
662 void
663 default_no_function_rodata_section (tree decl ATTRIBUTE_UNUSED)
665 readonly_data_section ();
668 /* Switch to section for variable DECL. RELOC is the same as the
669 argument to SELECT_SECTION. */
671 void
672 variable_section (tree decl, int reloc)
674 if (IN_NAMED_SECTION (decl))
675 named_section (decl, NULL, reloc);
676 else
677 targetm.asm_out.select_section (decl, reloc, DECL_ALIGN (decl));
680 /* Tell assembler to switch to the section for string merging. */
682 void
683 mergeable_string_section (tree decl ATTRIBUTE_UNUSED,
684 unsigned HOST_WIDE_INT align ATTRIBUTE_UNUSED,
685 unsigned int flags ATTRIBUTE_UNUSED)
687 if (HAVE_GAS_SHF_MERGE && flag_merge_constants
688 && TREE_CODE (decl) == STRING_CST
689 && TREE_CODE (TREE_TYPE (decl)) == ARRAY_TYPE
690 && align <= 256
691 && TREE_STRING_LENGTH (decl) >= int_size_in_bytes (TREE_TYPE (decl)))
693 enum machine_mode mode;
694 unsigned int modesize;
695 const char *str;
696 int i, j, len, unit;
697 char name[30];
699 mode = TYPE_MODE (TREE_TYPE (TREE_TYPE (decl)));
700 modesize = GET_MODE_BITSIZE (mode);
701 if (modesize >= 8 && modesize <= 256
702 && (modesize & (modesize - 1)) == 0)
704 if (align < modesize)
705 align = modesize;
707 str = TREE_STRING_POINTER (decl);
708 len = TREE_STRING_LENGTH (decl);
709 unit = GET_MODE_SIZE (mode);
711 /* Check for embedded NUL characters. */
712 for (i = 0; i < len; i += unit)
714 for (j = 0; j < unit; j++)
715 if (str[i + j] != '\0')
716 break;
717 if (j == unit)
718 break;
720 if (i == len - unit)
722 sprintf (name, ".rodata.str%d.%d", modesize / 8,
723 (int) (align / 8));
724 flags |= (modesize / 8) | SECTION_MERGE | SECTION_STRINGS;
725 if (!i && modesize < align)
727 /* A "" string with requested alignment greater than
728 character size might cause a problem:
729 if some other string required even bigger
730 alignment than "", then linker might think the
731 "" is just part of padding after some other string
732 and not put it into the hash table initially.
733 But this means "" could have smaller alignment
734 than requested. */
735 #ifdef ASM_OUTPUT_SECTION_START
736 named_section_flags (name, flags);
737 ASM_OUTPUT_SECTION_START (asm_out_file);
738 #else
739 readonly_data_section ();
740 #endif
741 return;
744 named_section_flags (name, flags);
745 return;
750 readonly_data_section ();
753 /* Tell assembler to switch to the section for constant merging. */
755 void
756 mergeable_constant_section (enum machine_mode mode ATTRIBUTE_UNUSED,
757 unsigned HOST_WIDE_INT align ATTRIBUTE_UNUSED,
758 unsigned int flags ATTRIBUTE_UNUSED)
760 unsigned int modesize = GET_MODE_BITSIZE (mode);
762 if (HAVE_GAS_SHF_MERGE && flag_merge_constants
763 && mode != VOIDmode
764 && mode != BLKmode
765 && modesize <= align
766 && align >= 8
767 && align <= 256
768 && (align & (align - 1)) == 0)
770 char name[24];
772 sprintf (name, ".rodata.cst%d", (int) (align / 8));
773 flags |= (align / 8) | SECTION_MERGE;
774 named_section_flags (name, flags);
775 return;
778 readonly_data_section ();
781 /* Given NAME, a putative register name, discard any customary prefixes. */
783 static const char *
784 strip_reg_name (const char *name)
786 #ifdef REGISTER_PREFIX
787 if (!strncmp (name, REGISTER_PREFIX, strlen (REGISTER_PREFIX)))
788 name += strlen (REGISTER_PREFIX);
789 #endif
790 if (name[0] == '%' || name[0] == '#')
791 name++;
792 return name;
795 /* The user has asked for a DECL to have a particular name. Set (or
796 change) it in such a way that we don't prefix an underscore to
797 it. */
798 void
799 set_user_assembler_name (tree decl, const char *name)
801 char *starred = alloca (strlen (name) + 2);
802 starred[0] = '*';
803 strcpy (starred + 1, name);
804 change_decl_assembler_name (decl, get_identifier (starred));
805 SET_DECL_RTL (decl, NULL_RTX);
808 /* Decode an `asm' spec for a declaration as a register name.
809 Return the register number, or -1 if nothing specified,
810 or -2 if the ASMSPEC is not `cc' or `memory' and is not recognized,
811 or -3 if ASMSPEC is `cc' and is not recognized,
812 or -4 if ASMSPEC is `memory' and is not recognized.
813 Accept an exact spelling or a decimal number.
814 Prefixes such as % are optional. */
817 decode_reg_name (const char *asmspec)
819 if (asmspec != 0)
821 int i;
823 /* Get rid of confusing prefixes. */
824 asmspec = strip_reg_name (asmspec);
826 /* Allow a decimal number as a "register name". */
827 for (i = strlen (asmspec) - 1; i >= 0; i--)
828 if (! ISDIGIT (asmspec[i]))
829 break;
830 if (asmspec[0] != 0 && i < 0)
832 i = atoi (asmspec);
833 if (i < FIRST_PSEUDO_REGISTER && i >= 0)
834 return i;
835 else
836 return -2;
839 for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
840 if (reg_names[i][0]
841 && ! strcmp (asmspec, strip_reg_name (reg_names[i])))
842 return i;
844 #ifdef ADDITIONAL_REGISTER_NAMES
846 static const struct { const char *const name; const int number; } table[]
847 = ADDITIONAL_REGISTER_NAMES;
849 for (i = 0; i < (int) ARRAY_SIZE (table); i++)
850 if (! strcmp (asmspec, table[i].name))
851 return table[i].number;
853 #endif /* ADDITIONAL_REGISTER_NAMES */
855 if (!strcmp (asmspec, "memory"))
856 return -4;
858 if (!strcmp (asmspec, "cc"))
859 return -3;
861 return -2;
864 return -1;
867 /* Create the DECL_RTL for a VAR_DECL or FUNCTION_DECL. DECL should
868 have static storage duration. In other words, it should not be an
869 automatic variable, including PARM_DECLs.
871 There is, however, one exception: this function handles variables
872 explicitly placed in a particular register by the user.
874 This is never called for PARM_DECL nodes. */
876 void
877 make_decl_rtl (tree decl)
879 const char *name = 0;
880 int reg_number;
881 rtx x;
883 /* Check that we are not being given an automatic variable. */
884 gcc_assert (TREE_CODE (decl) != PARM_DECL
885 && TREE_CODE (decl) != RESULT_DECL);
887 /* A weak alias has TREE_PUBLIC set but not the other bits. */
888 gcc_assert (TREE_CODE (decl) != VAR_DECL
889 || TREE_STATIC (decl)
890 || TREE_PUBLIC (decl)
891 || DECL_EXTERNAL (decl)
892 || DECL_REGISTER (decl));
894 /* And that we were not given a type or a label. */
895 gcc_assert (TREE_CODE (decl) != TYPE_DECL
896 && TREE_CODE (decl) != LABEL_DECL);
898 /* For a duplicate declaration, we can be called twice on the
899 same DECL node. Don't discard the RTL already made. */
900 if (DECL_RTL_SET_P (decl))
902 /* If the old RTL had the wrong mode, fix the mode. */
903 if (GET_MODE (DECL_RTL (decl)) != DECL_MODE (decl))
904 SET_DECL_RTL (decl, adjust_address_nv (DECL_RTL (decl),
905 DECL_MODE (decl), 0));
907 if (TREE_CODE (decl) != FUNCTION_DECL && DECL_REGISTER (decl))
908 return;
910 /* ??? Another way to do this would be to maintain a hashed
911 table of such critters. Instead of adding stuff to a DECL
912 to give certain attributes to it, we could use an external
913 hash map from DECL to set of attributes. */
915 /* Let the target reassign the RTL if it wants.
916 This is necessary, for example, when one machine specific
917 decl attribute overrides another. */
918 targetm.encode_section_info (decl, DECL_RTL (decl), false);
920 /* Make this function static known to the mudflap runtime. */
921 if (flag_mudflap && TREE_CODE (decl) == VAR_DECL)
922 mudflap_enqueue_decl (decl);
924 return;
927 name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
929 if (TREE_CODE (decl) != FUNCTION_DECL && DECL_REGISTER (decl))
931 reg_number = decode_reg_name (name);
932 /* First detect errors in declaring global registers. */
933 if (reg_number == -1)
934 error ("%Jregister name not specified for %qD", decl, decl);
935 else if (reg_number < 0)
936 error ("%Jinvalid register name for %qD", decl, decl);
937 else if (TYPE_MODE (TREE_TYPE (decl)) == BLKmode)
938 error ("%Jdata type of %qD isn%'t suitable for a register",
939 decl, decl);
940 else if (! HARD_REGNO_MODE_OK (reg_number, TYPE_MODE (TREE_TYPE (decl))))
941 error ("%Jregister specified for %qD isn%'t suitable for data type",
942 decl, decl);
943 /* Now handle properly declared static register variables. */
944 else
946 int nregs;
948 if (DECL_INITIAL (decl) != 0 && TREE_STATIC (decl))
950 DECL_INITIAL (decl) = 0;
951 error ("global register variable has initial value");
953 if (TREE_THIS_VOLATILE (decl))
954 warning ("volatile register variables don%'t "
955 "work as you might wish");
957 /* If the user specified one of the eliminables registers here,
958 e.g., FRAME_POINTER_REGNUM, we don't want to get this variable
959 confused with that register and be eliminated. This usage is
960 somewhat suspect... */
962 SET_DECL_RTL (decl, gen_rtx_raw_REG (DECL_MODE (decl), reg_number));
963 ORIGINAL_REGNO (DECL_RTL (decl)) = reg_number;
964 REG_USERVAR_P (DECL_RTL (decl)) = 1;
966 if (TREE_STATIC (decl))
968 /* Make this register global, so not usable for anything
969 else. */
970 #ifdef ASM_DECLARE_REGISTER_GLOBAL
971 name = IDENTIFIER_POINTER (DECL_NAME (decl));
972 ASM_DECLARE_REGISTER_GLOBAL (asm_out_file, decl, reg_number, name);
973 #endif
974 nregs = hard_regno_nregs[reg_number][DECL_MODE (decl)];
975 while (nregs > 0)
976 globalize_reg (reg_number + --nregs);
979 /* As a register variable, it has no section. */
980 return;
983 /* Now handle ordinary static variables and functions (in memory).
984 Also handle vars declared register invalidly. */
985 else if (name[0] == '*')
987 #ifdef REGISTER_PREFIX
988 if (strlen (REGISTER_PREFIX) != 0)
990 reg_number = decode_reg_name (name);
991 if (reg_number >= 0 || reg_number == -3)
992 error ("%Jregister name given for non-register variable %qD", decl, decl);
994 #endif
997 /* Specifying a section attribute on a variable forces it into a
998 non-.bss section, and thus it cannot be common. */
999 if (TREE_CODE (decl) == VAR_DECL
1000 && DECL_SECTION_NAME (decl) != NULL_TREE
1001 && DECL_INITIAL (decl) == NULL_TREE
1002 && DECL_COMMON (decl))
1003 DECL_COMMON (decl) = 0;
1005 /* Variables can't be both common and weak. */
1006 if (TREE_CODE (decl) == VAR_DECL && DECL_WEAK (decl))
1007 DECL_COMMON (decl) = 0;
1009 x = gen_rtx_SYMBOL_REF (Pmode, name);
1010 SYMBOL_REF_WEAK (x) = DECL_WEAK (decl);
1011 SYMBOL_REF_DECL (x) = decl;
1013 x = gen_rtx_MEM (DECL_MODE (decl), x);
1014 if (TREE_CODE (decl) != FUNCTION_DECL)
1015 set_mem_attributes (x, decl, 1);
1016 SET_DECL_RTL (decl, x);
1018 /* Optionally set flags or add text to the name to record information
1019 such as that it is a function name.
1020 If the name is changed, the macro ASM_OUTPUT_LABELREF
1021 will have to know how to strip this information. */
1022 targetm.encode_section_info (decl, DECL_RTL (decl), true);
1024 /* Make this function static known to the mudflap runtime. */
1025 if (flag_mudflap && TREE_CODE (decl) == VAR_DECL)
1026 mudflap_enqueue_decl (decl);
1029 /* Make the rtl for variable VAR be volatile.
1030 Use this only for static variables. */
1032 void
1033 make_var_volatile (tree var)
1035 gcc_assert (MEM_P (DECL_RTL (var)));
1037 MEM_VOLATILE_P (DECL_RTL (var)) = 1;
1040 /* Output a string of literal assembler code
1041 for an `asm' keyword used between functions. */
1043 void
1044 assemble_asm (tree string)
1046 app_enable ();
1048 if (TREE_CODE (string) == ADDR_EXPR)
1049 string = TREE_OPERAND (string, 0);
1051 fprintf (asm_out_file, "\t%s\n", TREE_STRING_POINTER (string));
1054 /* Record an element in the table of global destructors. SYMBOL is
1055 a SYMBOL_REF of the function to be called; PRIORITY is a number
1056 between 0 and MAX_INIT_PRIORITY. */
1058 void
1059 default_stabs_asm_out_destructor (rtx symbol ATTRIBUTE_UNUSED,
1060 int priority ATTRIBUTE_UNUSED)
1062 #if defined DBX_DEBUGGING_INFO || defined XCOFF_DEBUGGING_INFO
1063 /* Tell GNU LD that this is part of the static destructor set.
1064 This will work for any system that uses stabs, most usefully
1065 aout systems. */
1066 dbxout_begin_simple_stabs ("___DTOR_LIST__", 22 /* N_SETT */);
1067 dbxout_stab_value_label (XSTR (symbol, 0));
1068 #else
1069 sorry ("global destructors not supported on this target");
1070 #endif
1073 void
1074 default_named_section_asm_out_destructor (rtx symbol, int priority)
1076 const char *section = ".dtors";
1077 char buf[16];
1079 /* ??? This only works reliably with the GNU linker. */
1080 if (priority != DEFAULT_INIT_PRIORITY)
1082 sprintf (buf, ".dtors.%.5u",
1083 /* Invert the numbering so the linker puts us in the proper
1084 order; constructors are run from right to left, and the
1085 linker sorts in increasing order. */
1086 MAX_INIT_PRIORITY - priority);
1087 section = buf;
1090 named_section_flags (section, SECTION_WRITE);
1091 assemble_align (POINTER_SIZE);
1092 assemble_integer (symbol, POINTER_SIZE / BITS_PER_UNIT, POINTER_SIZE, 1);
1095 #ifdef DTORS_SECTION_ASM_OP
1096 void
1097 dtors_section (void)
1099 if (in_section != in_dtors)
1101 in_section = in_dtors;
1102 fputs (DTORS_SECTION_ASM_OP, asm_out_file);
1103 fputc ('\n', asm_out_file);
1107 void
1108 default_dtor_section_asm_out_destructor (rtx symbol,
1109 int priority ATTRIBUTE_UNUSED)
1111 dtors_section ();
1112 assemble_align (POINTER_SIZE);
1113 assemble_integer (symbol, POINTER_SIZE / BITS_PER_UNIT, POINTER_SIZE, 1);
1115 #endif
1117 /* Likewise for global constructors. */
1119 void
1120 default_stabs_asm_out_constructor (rtx symbol ATTRIBUTE_UNUSED,
1121 int priority ATTRIBUTE_UNUSED)
1123 #if defined DBX_DEBUGGING_INFO || defined XCOFF_DEBUGGING_INFO
1124 /* Tell GNU LD that this is part of the static destructor set.
1125 This will work for any system that uses stabs, most usefully
1126 aout systems. */
1127 dbxout_begin_simple_stabs ("___CTOR_LIST__", 22 /* N_SETT */);
1128 dbxout_stab_value_label (XSTR (symbol, 0));
1129 #else
1130 sorry ("global constructors not supported on this target");
1131 #endif
1134 void
1135 default_named_section_asm_out_constructor (rtx symbol, int priority)
1137 const char *section = ".ctors";
1138 char buf[16];
1140 /* ??? This only works reliably with the GNU linker. */
1141 if (priority != DEFAULT_INIT_PRIORITY)
1143 sprintf (buf, ".ctors.%.5u",
1144 /* Invert the numbering so the linker puts us in the proper
1145 order; constructors are run from right to left, and the
1146 linker sorts in increasing order. */
1147 MAX_INIT_PRIORITY - priority);
1148 section = buf;
1151 named_section_flags (section, SECTION_WRITE);
1152 assemble_align (POINTER_SIZE);
1153 assemble_integer (symbol, POINTER_SIZE / BITS_PER_UNIT, POINTER_SIZE, 1);
1156 #ifdef CTORS_SECTION_ASM_OP
1157 void
1158 ctors_section (void)
1160 if (in_section != in_ctors)
1162 in_section = in_ctors;
1163 fputs (CTORS_SECTION_ASM_OP, asm_out_file);
1164 fputc ('\n', asm_out_file);
1168 void
1169 default_ctor_section_asm_out_constructor (rtx symbol,
1170 int priority ATTRIBUTE_UNUSED)
1172 ctors_section ();
1173 assemble_align (POINTER_SIZE);
1174 assemble_integer (symbol, POINTER_SIZE / BITS_PER_UNIT, POINTER_SIZE, 1);
1176 #endif
1178 /* CONSTANT_POOL_BEFORE_FUNCTION may be defined as an expression with
1179 a nonzero value if the constant pool should be output before the
1180 start of the function, or a zero value if the pool should output
1181 after the end of the function. The default is to put it before the
1182 start. */
1184 #ifndef CONSTANT_POOL_BEFORE_FUNCTION
1185 #define CONSTANT_POOL_BEFORE_FUNCTION 1
1186 #endif
1188 /* DECL is an object (either VAR_DECL or FUNCTION_DECL) which is going
1189 to be output to assembler.
1190 Set first_global_object_name and weak_global_object_name as appropriate. */
1192 void
1193 notice_global_symbol (tree decl)
1195 const char **type = &first_global_object_name;
1197 if (first_global_object_name
1198 || !TREE_PUBLIC (decl) || DECL_EXTERNAL (decl)
1199 || !DECL_NAME (decl)
1200 || (TREE_CODE (decl) != FUNCTION_DECL
1201 && (TREE_CODE (decl) != VAR_DECL
1202 || (DECL_COMMON (decl)
1203 && (DECL_INITIAL (decl) == 0
1204 || DECL_INITIAL (decl) == error_mark_node))))
1205 || !MEM_P (DECL_RTL (decl)))
1206 return;
1208 /* We win when global object is found, but it is useful to know about weak
1209 symbol as well so we can produce nicer unique names. */
1210 if (DECL_WEAK (decl) || DECL_ONE_ONLY (decl))
1211 type = &weak_global_object_name;
1213 if (!*type)
1215 const char *p;
1216 char *name;
1217 rtx decl_rtl = DECL_RTL (decl);
1219 p = targetm.strip_name_encoding (XSTR (XEXP (decl_rtl, 0), 0));
1220 name = xstrdup (p);
1222 *type = name;
1226 /* Output assembler code for the constant pool of a function and associated
1227 with defining the name of the function. DECL describes the function.
1228 NAME is the function's name. For the constant pool, we use the current
1229 constant pool data. */
1231 void
1232 assemble_start_function (tree decl, const char *fnname)
1234 int align;
1235 char tmp_label[100];
1236 bool hot_label_written = false;
1237 struct function *cfun = DECL_STRUCT_FUNCTION (decl);
1239 cfun->unlikely_text_section_name = NULL;
1241 first_function_block_is_cold = false;
1242 if (flag_reorder_blocks_and_partition)
1244 ASM_GENERATE_INTERNAL_LABEL (tmp_label, "HOTB", const_labelno);
1245 cfun->hot_section_label = ggc_strdup (tmp_label);
1246 ASM_GENERATE_INTERNAL_LABEL (tmp_label, "COLDB", const_labelno);
1247 cfun->cold_section_label = ggc_strdup (tmp_label);
1248 ASM_GENERATE_INTERNAL_LABEL (tmp_label, "HOTE", const_labelno);
1249 cfun->hot_section_end_label = ggc_strdup (tmp_label);
1250 ASM_GENERATE_INTERNAL_LABEL (tmp_label, "COLDE", const_labelno);
1251 cfun->cold_section_end_label = ggc_strdup (tmp_label);
1252 const_labelno++;
1254 else
1256 cfun->hot_section_label = NULL;
1257 cfun->cold_section_label = NULL;
1258 cfun->hot_section_end_label = NULL;
1259 cfun->cold_section_end_label = NULL;
1262 /* The following code does not need preprocessing in the assembler. */
1264 app_disable ();
1266 if (CONSTANT_POOL_BEFORE_FUNCTION)
1267 output_constant_pool (fnname, decl);
1269 /* Make sure the not and cold text (code) sections are properly
1270 aligned. This is necessary here in the case where the function
1271 has both hot and cold sections, because we don't want to re-set
1272 the alignment when the section switch happens mid-function. */
1274 if (flag_reorder_blocks_and_partition)
1276 unlikely_text_section ();
1277 assemble_align (FUNCTION_BOUNDARY);
1278 ASM_OUTPUT_LABEL (asm_out_file, cfun->cold_section_label);
1279 if (BB_PARTITION (ENTRY_BLOCK_PTR->next_bb) == BB_COLD_PARTITION)
1281 /* Since the function starts with a cold section, we need to
1282 explicitly align the hot section and write out the hot
1283 section label. */
1284 text_section ();
1285 assemble_align (FUNCTION_BOUNDARY);
1286 ASM_OUTPUT_LABEL (asm_out_file, cfun->hot_section_label);
1287 hot_label_written = true;
1288 first_function_block_is_cold = true;
1291 else if (DECL_SECTION_NAME (decl))
1293 /* Calls to function_section rely on first_function_block_is_cold
1294 being accurate. The first block may be cold even if we aren't
1295 doing partitioning, if the entire function was decided by
1296 choose_function_section (predict.c) to be cold. */
1298 int i;
1299 int len;
1300 char *s;
1302 initialize_cold_section_name ();
1304 /* The following is necessary, because 'strcmp
1305 (TREE_STRING_POINTER (DECL_SECTION_NAME (decl)), blah)' always
1306 fails, presumably because TREE_STRING_POINTER is declared to
1307 be an array of size 1 of char. */
1309 len = TREE_STRING_LENGTH (DECL_SECTION_NAME (decl));
1310 s = (char *) xmalloc (len + 1);
1312 for (i = 0; i < len; i ++)
1313 s[i] = (TREE_STRING_POINTER (DECL_SECTION_NAME (decl)))[i];
1314 s[len] = '\0';
1316 if (cfun->unlikely_text_section_name
1317 && (strcmp (s, cfun->unlikely_text_section_name) == 0))
1318 first_function_block_is_cold = true;
1321 last_text_section = no_section;
1322 in_section = no_section;
1323 resolve_unique_section (decl, 0, flag_function_sections);
1325 /* Switch to the correct text section for the start of the function. */
1327 function_section (decl);
1328 if (flag_reorder_blocks_and_partition && !hot_label_written)
1329 ASM_OUTPUT_LABEL (asm_out_file, cfun->hot_section_label);
1331 /* Tell assembler to move to target machine's alignment for functions. */
1332 align = floor_log2 (FUNCTION_BOUNDARY / BITS_PER_UNIT);
1333 if (align < force_align_functions_log)
1334 align = force_align_functions_log;
1335 if (align > 0)
1337 ASM_OUTPUT_ALIGN (asm_out_file, align);
1340 /* Handle a user-specified function alignment.
1341 Note that we still need to align to FUNCTION_BOUNDARY, as above,
1342 because ASM_OUTPUT_MAX_SKIP_ALIGN might not do any alignment at all. */
1343 if (align_functions_log > align
1344 && cfun->function_frequency != FUNCTION_FREQUENCY_UNLIKELY_EXECUTED)
1346 #ifdef ASM_OUTPUT_MAX_SKIP_ALIGN
1347 ASM_OUTPUT_MAX_SKIP_ALIGN (asm_out_file,
1348 align_functions_log, align_functions - 1);
1349 #else
1350 ASM_OUTPUT_ALIGN (asm_out_file, align_functions_log);
1351 #endif
1354 #ifdef ASM_OUTPUT_FUNCTION_PREFIX
1355 ASM_OUTPUT_FUNCTION_PREFIX (asm_out_file, fnname);
1356 #endif
1358 (*debug_hooks->begin_function) (decl);
1360 /* Make function name accessible from other files, if appropriate. */
1362 if (TREE_PUBLIC (decl))
1364 notice_global_symbol (decl);
1366 globalize_decl (decl);
1368 maybe_assemble_visibility (decl);
1371 if (DECL_PRESERVE_P (decl))
1372 targetm.asm_out.mark_decl_preserved (fnname);
1374 /* Do any machine/system dependent processing of the function name. */
1375 #ifdef ASM_DECLARE_FUNCTION_NAME
1376 ASM_DECLARE_FUNCTION_NAME (asm_out_file, fnname, current_function_decl);
1377 #else
1378 /* Standard thing is just output label for the function. */
1379 ASM_OUTPUT_LABEL (asm_out_file, fnname);
1380 #endif /* ASM_DECLARE_FUNCTION_NAME */
1382 insert_section_boundary_note ();
1385 /* Output assembler code associated with defining the size of the
1386 function. DECL describes the function. NAME is the function's name. */
1388 void
1389 assemble_end_function (tree decl, const char *fnname)
1391 #ifdef ASM_DECLARE_FUNCTION_SIZE
1392 ASM_DECLARE_FUNCTION_SIZE (asm_out_file, fnname, decl);
1393 #endif
1394 if (! CONSTANT_POOL_BEFORE_FUNCTION)
1396 output_constant_pool (fnname, decl);
1397 function_section (decl); /* need to switch back */
1399 /* Output labels for end of hot/cold text sections (to be used by
1400 debug info.) */
1401 if (flag_reorder_blocks_and_partition)
1403 enum in_section save_text_section;
1404 struct function *cfun = DECL_STRUCT_FUNCTION (decl);
1406 save_text_section = in_section;
1407 unlikely_text_section ();
1408 ASM_OUTPUT_LABEL (asm_out_file, cfun->cold_section_end_label);
1409 text_section ();
1410 ASM_OUTPUT_LABEL (asm_out_file, cfun->hot_section_end_label);
1411 if (save_text_section == in_unlikely_executed_text)
1412 unlikely_text_section ();
1416 /* Assemble code to leave SIZE bytes of zeros. */
1418 void
1419 assemble_zeros (unsigned HOST_WIDE_INT size)
1421 /* Do no output if -fsyntax-only. */
1422 if (flag_syntax_only)
1423 return;
1425 #ifdef ASM_NO_SKIP_IN_TEXT
1426 /* The `space' pseudo in the text section outputs nop insns rather than 0s,
1427 so we must output 0s explicitly in the text section. */
1428 if ((ASM_NO_SKIP_IN_TEXT && in_text_section ())
1429 || (ASM_NO_SKIP_IN_TEXT && in_unlikely_text_section ()))
1431 unsigned HOST_WIDE_INT i;
1432 for (i = 0; i < size; i++)
1433 assemble_integer (const0_rtx, 1, BITS_PER_UNIT, 1);
1435 else
1436 #endif
1437 if (size > 0)
1438 ASM_OUTPUT_SKIP (asm_out_file, size);
1441 /* Assemble an alignment pseudo op for an ALIGN-bit boundary. */
1443 void
1444 assemble_align (int align)
1446 if (align > BITS_PER_UNIT)
1448 ASM_OUTPUT_ALIGN (asm_out_file, floor_log2 (align / BITS_PER_UNIT));
1452 /* Assemble a string constant with the specified C string as contents. */
1454 void
1455 assemble_string (const char *p, int size)
1457 int pos = 0;
1458 int maximum = 2000;
1460 /* If the string is very long, split it up. */
1462 while (pos < size)
1464 int thissize = size - pos;
1465 if (thissize > maximum)
1466 thissize = maximum;
1468 ASM_OUTPUT_ASCII (asm_out_file, p, thissize);
1470 pos += thissize;
1471 p += thissize;
1476 #if defined ASM_OUTPUT_ALIGNED_DECL_LOCAL
1477 #define ASM_EMIT_LOCAL(decl, name, size, rounded) \
1478 ASM_OUTPUT_ALIGNED_DECL_LOCAL (asm_out_file, decl, name, size, DECL_ALIGN (decl))
1479 #else
1480 #if defined ASM_OUTPUT_ALIGNED_LOCAL
1481 #define ASM_EMIT_LOCAL(decl, name, size, rounded) \
1482 ASM_OUTPUT_ALIGNED_LOCAL (asm_out_file, name, size, DECL_ALIGN (decl))
1483 #else
1484 #define ASM_EMIT_LOCAL(decl, name, size, rounded) \
1485 ASM_OUTPUT_LOCAL (asm_out_file, name, size, rounded)
1486 #endif
1487 #endif
1489 #if defined ASM_OUTPUT_ALIGNED_BSS
1490 #define ASM_EMIT_BSS(decl, name, size, rounded) \
1491 ASM_OUTPUT_ALIGNED_BSS (asm_out_file, decl, name, size, DECL_ALIGN (decl))
1492 #else
1493 #if defined ASM_OUTPUT_BSS
1494 #define ASM_EMIT_BSS(decl, name, size, rounded) \
1495 ASM_OUTPUT_BSS (asm_out_file, decl, name, size, rounded)
1496 #else
1497 #undef ASM_EMIT_BSS
1498 #endif
1499 #endif
1501 #if defined ASM_OUTPUT_ALIGNED_DECL_COMMON
1502 #define ASM_EMIT_COMMON(decl, name, size, rounded) \
1503 ASM_OUTPUT_ALIGNED_DECL_COMMON (asm_out_file, decl, name, size, DECL_ALIGN (decl))
1504 #else
1505 #if defined ASM_OUTPUT_ALIGNED_COMMON
1506 #define ASM_EMIT_COMMON(decl, name, size, rounded) \
1507 ASM_OUTPUT_ALIGNED_COMMON (asm_out_file, name, size, DECL_ALIGN (decl))
1508 #else
1509 #define ASM_EMIT_COMMON(decl, name, size, rounded) \
1510 ASM_OUTPUT_COMMON (asm_out_file, name, size, rounded)
1511 #endif
1512 #endif
1514 static bool
1515 asm_emit_uninitialised (tree decl, const char *name,
1516 unsigned HOST_WIDE_INT size ATTRIBUTE_UNUSED,
1517 unsigned HOST_WIDE_INT rounded ATTRIBUTE_UNUSED)
1519 enum
1521 asm_dest_common,
1522 asm_dest_bss,
1523 asm_dest_local
1525 destination = asm_dest_local;
1527 /* ??? We should handle .bss via select_section mechanisms rather than
1528 via special target hooks. That would eliminate this special case. */
1529 if (TREE_PUBLIC (decl))
1531 if (!DECL_COMMON (decl))
1532 #ifdef ASM_EMIT_BSS
1533 destination = asm_dest_bss;
1534 #else
1535 return false;
1536 #endif
1537 else
1538 destination = asm_dest_common;
1541 if (destination != asm_dest_common)
1543 resolve_unique_section (decl, 0, flag_data_sections);
1544 /* Custom sections don't belong here. */
1545 if (DECL_SECTION_NAME (decl))
1546 return false;
1549 if (destination == asm_dest_bss)
1550 globalize_decl (decl);
1552 if (flag_shared_data)
1554 switch (destination)
1556 #ifdef ASM_OUTPUT_SHARED_BSS
1557 case asm_dest_bss:
1558 ASM_OUTPUT_SHARED_BSS (asm_out_file, decl, name, size, rounded);
1559 return;
1560 #endif
1561 #ifdef ASM_OUTPUT_SHARED_COMMON
1562 case asm_dest_common:
1563 ASM_OUTPUT_SHARED_COMMON (asm_out_file, name, size, rounded);
1564 return;
1565 #endif
1566 #ifdef ASM_OUTPUT_SHARED_LOCAL
1567 case asm_dest_local:
1568 ASM_OUTPUT_SHARED_LOCAL (asm_out_file, name, size, rounded);
1569 return;
1570 #endif
1571 default:
1572 break;
1576 switch (destination)
1578 #ifdef ASM_EMIT_BSS
1579 case asm_dest_bss:
1580 ASM_EMIT_BSS (decl, name, size, rounded);
1581 break;
1582 #endif
1583 case asm_dest_common:
1584 ASM_EMIT_COMMON (decl, name, size, rounded);
1585 break;
1586 case asm_dest_local:
1587 ASM_EMIT_LOCAL (decl, name, size, rounded);
1588 break;
1589 default:
1590 gcc_unreachable ();
1593 return true;
1596 /* Assemble everything that is needed for a variable or function declaration.
1597 Not used for automatic variables, and not used for function definitions.
1598 Should not be called for variables of incomplete structure type.
1600 TOP_LEVEL is nonzero if this variable has file scope.
1601 AT_END is nonzero if this is the special handling, at end of compilation,
1602 to define things that have had only tentative definitions.
1603 DONT_OUTPUT_DATA if nonzero means don't actually output the
1604 initial value (that will be done by the caller). */
1606 void
1607 assemble_variable (tree decl, int top_level ATTRIBUTE_UNUSED,
1608 int at_end ATTRIBUTE_UNUSED, int dont_output_data)
1610 const char *name;
1611 unsigned int align;
1612 int reloc = 0;
1613 rtx decl_rtl;
1615 if (lang_hooks.decls.prepare_assemble_variable)
1616 lang_hooks.decls.prepare_assemble_variable (decl);
1618 last_assemble_variable_decl = 0;
1620 /* Normally no need to say anything here for external references,
1621 since assemble_external is called by the language-specific code
1622 when a declaration is first seen. */
1624 if (DECL_EXTERNAL (decl))
1625 return;
1627 /* Output no assembler code for a function declaration.
1628 Only definitions of functions output anything. */
1630 if (TREE_CODE (decl) == FUNCTION_DECL)
1631 return;
1633 /* Do nothing for global register variables. */
1634 if (DECL_RTL_SET_P (decl) && REG_P (DECL_RTL (decl)))
1636 TREE_ASM_WRITTEN (decl) = 1;
1637 return;
1640 /* If type was incomplete when the variable was declared,
1641 see if it is complete now. */
1643 if (DECL_SIZE (decl) == 0)
1644 layout_decl (decl, 0);
1646 /* Still incomplete => don't allocate it; treat the tentative defn
1647 (which is what it must have been) as an `extern' reference. */
1649 if (!dont_output_data && DECL_SIZE (decl) == 0)
1651 error ("%Jstorage size of %qD isn%'t known", decl, decl);
1652 TREE_ASM_WRITTEN (decl) = 1;
1653 return;
1656 /* The first declaration of a variable that comes through this function
1657 decides whether it is global (in C, has external linkage)
1658 or local (in C, has internal linkage). So do nothing more
1659 if this function has already run. */
1661 if (TREE_ASM_WRITTEN (decl))
1662 return;
1664 /* Make sure targetm.encode_section_info is invoked before we set
1665 ASM_WRITTEN. */
1666 decl_rtl = DECL_RTL (decl);
1668 TREE_ASM_WRITTEN (decl) = 1;
1670 /* Do no output if -fsyntax-only. */
1671 if (flag_syntax_only)
1672 return;
1674 app_disable ();
1676 if (! dont_output_data
1677 && ! host_integerp (DECL_SIZE_UNIT (decl), 1))
1679 error ("%Jsize of variable %qD is too large", decl, decl);
1680 return;
1683 name = XSTR (XEXP (decl_rtl, 0), 0);
1684 if (TREE_PUBLIC (decl) && DECL_NAME (decl))
1685 notice_global_symbol (decl);
1687 /* Compute the alignment of this data. */
1689 align = DECL_ALIGN (decl);
1691 /* In the case for initialing an array whose length isn't specified,
1692 where we have not yet been able to do the layout,
1693 figure out the proper alignment now. */
1694 if (dont_output_data && DECL_SIZE (decl) == 0
1695 && TREE_CODE (TREE_TYPE (decl)) == ARRAY_TYPE)
1696 align = MAX (align, TYPE_ALIGN (TREE_TYPE (TREE_TYPE (decl))));
1698 /* Some object file formats have a maximum alignment which they support.
1699 In particular, a.out format supports a maximum alignment of 4. */
1700 if (align > MAX_OFILE_ALIGNMENT)
1702 warning ("%Jalignment of %qD is greater than maximum object "
1703 "file alignment. Using %d", decl, decl,
1704 MAX_OFILE_ALIGNMENT/BITS_PER_UNIT);
1705 align = MAX_OFILE_ALIGNMENT;
1708 /* On some machines, it is good to increase alignment sometimes. */
1709 if (! DECL_USER_ALIGN (decl))
1711 #ifdef DATA_ALIGNMENT
1712 align = DATA_ALIGNMENT (TREE_TYPE (decl), align);
1713 #endif
1714 #ifdef CONSTANT_ALIGNMENT
1715 if (DECL_INITIAL (decl) != 0 && DECL_INITIAL (decl) != error_mark_node)
1716 align = CONSTANT_ALIGNMENT (DECL_INITIAL (decl), align);
1717 #endif
1720 /* Reset the alignment in case we have made it tighter, so we can benefit
1721 from it in get_pointer_alignment. */
1722 DECL_ALIGN (decl) = align;
1723 set_mem_align (decl_rtl, align);
1725 if (TREE_PUBLIC (decl))
1726 maybe_assemble_visibility (decl);
1728 if (DECL_PRESERVE_P (decl))
1729 targetm.asm_out.mark_decl_preserved (name);
1731 /* Handle uninitialized definitions. */
1733 /* If the decl has been given an explicit section name, then it
1734 isn't common, and shouldn't be handled as such. */
1735 if (DECL_SECTION_NAME (decl) || dont_output_data)
1737 /* We don't implement common thread-local data at present. */
1738 else if (DECL_THREAD_LOCAL (decl))
1740 if (DECL_COMMON (decl))
1741 sorry ("thread-local COMMON data not implemented");
1743 else if (DECL_INITIAL (decl) == 0
1744 || DECL_INITIAL (decl) == error_mark_node
1745 || (flag_zero_initialized_in_bss
1746 /* Leave constant zeroes in .rodata so they can be shared. */
1747 && !TREE_READONLY (decl)
1748 && initializer_zerop (DECL_INITIAL (decl))))
1750 unsigned HOST_WIDE_INT size = tree_low_cst (DECL_SIZE_UNIT (decl), 1);
1751 unsigned HOST_WIDE_INT rounded = size;
1753 /* Don't allocate zero bytes of common,
1754 since that means "undefined external" in the linker. */
1755 if (size == 0)
1756 rounded = 1;
1758 /* Round size up to multiple of BIGGEST_ALIGNMENT bits
1759 so that each uninitialized object starts on such a boundary. */
1760 rounded += (BIGGEST_ALIGNMENT / BITS_PER_UNIT) - 1;
1761 rounded = (rounded / (BIGGEST_ALIGNMENT / BITS_PER_UNIT)
1762 * (BIGGEST_ALIGNMENT / BITS_PER_UNIT));
1764 #if !defined(ASM_OUTPUT_ALIGNED_COMMON) && !defined(ASM_OUTPUT_ALIGNED_DECL_COMMON) && !defined(ASM_OUTPUT_ALIGNED_BSS)
1765 if ((unsigned HOST_WIDE_INT) DECL_ALIGN_UNIT (decl) > rounded)
1766 warning ("%Jrequested alignment for %qD is greater than "
1767 "implemented alignment of %d", decl, decl, rounded);
1768 #endif
1770 /* If the target cannot output uninitialized but not common global data
1771 in .bss, then we have to use .data, so fall through. */
1772 if (asm_emit_uninitialised (decl, name, size, rounded))
1773 return;
1776 /* Handle initialized definitions.
1777 Also handle uninitialized global definitions if -fno-common and the
1778 target doesn't support ASM_OUTPUT_BSS. */
1780 /* First make the assembler name(s) global if appropriate. */
1781 if (TREE_PUBLIC (decl) && DECL_NAME (decl))
1782 globalize_decl (decl);
1784 /* Output any data that we will need to use the address of. */
1785 if (DECL_INITIAL (decl) == error_mark_node)
1786 reloc = contains_pointers_p (TREE_TYPE (decl)) ? 3 : 0;
1787 else if (DECL_INITIAL (decl))
1789 reloc = compute_reloc_for_constant (DECL_INITIAL (decl));
1790 output_addressed_constants (DECL_INITIAL (decl));
1793 /* Switch to the appropriate section. */
1794 resolve_unique_section (decl, reloc, flag_data_sections);
1795 variable_section (decl, reloc);
1797 /* dbxout.c needs to know this. */
1798 if (in_text_section () || in_unlikely_text_section ())
1799 DECL_IN_TEXT_SECTION (decl) = 1;
1801 /* Output the alignment of this data. */
1802 if (align > BITS_PER_UNIT)
1803 ASM_OUTPUT_ALIGN (asm_out_file, floor_log2 (DECL_ALIGN_UNIT (decl)));
1805 /* Do any machine/system dependent processing of the object. */
1806 #ifdef ASM_DECLARE_OBJECT_NAME
1807 last_assemble_variable_decl = decl;
1808 ASM_DECLARE_OBJECT_NAME (asm_out_file, name, decl);
1809 #else
1810 /* Standard thing is just output label for the object. */
1811 ASM_OUTPUT_LABEL (asm_out_file, name);
1812 #endif /* ASM_DECLARE_OBJECT_NAME */
1814 if (!dont_output_data)
1816 if (DECL_INITIAL (decl)
1817 && DECL_INITIAL (decl) != error_mark_node
1818 && !initializer_zerop (DECL_INITIAL (decl)))
1819 /* Output the actual data. */
1820 output_constant (DECL_INITIAL (decl),
1821 tree_low_cst (DECL_SIZE_UNIT (decl), 1),
1822 align);
1823 else
1824 /* Leave space for it. */
1825 assemble_zeros (tree_low_cst (DECL_SIZE_UNIT (decl), 1));
1829 /* Return 1 if type TYPE contains any pointers. */
1831 static int
1832 contains_pointers_p (tree type)
1834 switch (TREE_CODE (type))
1836 case POINTER_TYPE:
1837 case REFERENCE_TYPE:
1838 /* I'm not sure whether OFFSET_TYPE needs this treatment,
1839 so I'll play safe and return 1. */
1840 case OFFSET_TYPE:
1841 return 1;
1843 case RECORD_TYPE:
1844 case UNION_TYPE:
1845 case QUAL_UNION_TYPE:
1847 tree fields;
1848 /* For a type that has fields, see if the fields have pointers. */
1849 for (fields = TYPE_FIELDS (type); fields; fields = TREE_CHAIN (fields))
1850 if (TREE_CODE (fields) == FIELD_DECL
1851 && contains_pointers_p (TREE_TYPE (fields)))
1852 return 1;
1853 return 0;
1856 case ARRAY_TYPE:
1857 /* An array type contains pointers if its element type does. */
1858 return contains_pointers_p (TREE_TYPE (type));
1860 default:
1861 return 0;
1865 /* In unit-at-a-time mode, we delay assemble_external processing until
1866 the compilation unit is finalized. This is the best we can do for
1867 right now (i.e. stage 3 of GCC 4.0) - the right thing is to delay
1868 it all the way to final. See PR 17982 for further discussion. */
1869 static GTY(()) tree pending_assemble_externals;
1871 #ifdef ASM_OUTPUT_EXTERNAL
1872 /* True if DECL is a function decl for which no out-of-line copy exists.
1873 It is assumed that DECL's assembler name has been set. */
1875 static bool
1876 incorporeal_function_p (tree decl)
1878 if (TREE_CODE (decl) == FUNCTION_DECL && DECL_BUILT_IN (decl))
1880 const char *name;
1882 if (DECL_BUILT_IN_CLASS (decl) == BUILT_IN_NORMAL
1883 && DECL_FUNCTION_CODE (decl) == BUILT_IN_ALLOCA)
1884 return true;
1886 name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
1887 if (strncmp (name, "__builtin_", strlen ("__builtin_")) == 0)
1888 return true;
1890 return false;
1893 /* Actually do the tests to determine if this is necessary, and invoke
1894 ASM_OUTPUT_EXTERNAL. */
1895 static void
1896 assemble_external_real (tree decl)
1898 rtx rtl = DECL_RTL (decl);
1900 if (MEM_P (rtl) && GET_CODE (XEXP (rtl, 0)) == SYMBOL_REF
1901 && !SYMBOL_REF_USED (XEXP (rtl, 0))
1902 && !incorporeal_function_p (decl))
1904 /* Some systems do require some output. */
1905 SYMBOL_REF_USED (XEXP (rtl, 0)) = 1;
1906 ASM_OUTPUT_EXTERNAL (asm_out_file, decl, XSTR (XEXP (rtl, 0), 0));
1909 #endif
1911 void
1912 process_pending_assemble_externals (void)
1914 #ifdef ASM_OUTPUT_EXTERNAL
1915 tree list;
1916 for (list = pending_assemble_externals; list; list = TREE_CHAIN (list))
1917 assemble_external_real (TREE_VALUE (list));
1919 pending_assemble_externals = 0;
1920 #endif
1923 /* Output something to declare an external symbol to the assembler.
1924 (Most assemblers don't need this, so we normally output nothing.)
1925 Do nothing if DECL is not external. */
1927 void
1928 assemble_external (tree decl ATTRIBUTE_UNUSED)
1930 /* Because most platforms do not define ASM_OUTPUT_EXTERNAL, the
1931 main body of this code is only rarely exercised. To provide some
1932 testing, on all platforms, we make sure that the ASM_OUT_FILE is
1933 open. If it's not, we should not be calling this function. */
1934 gcc_assert (asm_out_file);
1936 #ifdef ASM_OUTPUT_EXTERNAL
1937 if (!DECL_P (decl) || !DECL_EXTERNAL (decl) || !TREE_PUBLIC (decl))
1938 return;
1940 if (flag_unit_at_a_time)
1941 pending_assemble_externals = tree_cons (0, decl,
1942 pending_assemble_externals);
1943 else
1944 assemble_external_real (decl);
1945 #endif
1948 /* Similar, for calling a library function FUN. */
1950 void
1951 assemble_external_libcall (rtx fun)
1953 /* Declare library function name external when first used, if nec. */
1954 if (! SYMBOL_REF_USED (fun))
1956 SYMBOL_REF_USED (fun) = 1;
1957 targetm.asm_out.external_libcall (fun);
1961 /* Assemble a label named NAME. */
1963 void
1964 assemble_label (const char *name)
1966 ASM_OUTPUT_LABEL (asm_out_file, name);
1969 /* Set the symbol_referenced flag for ID. */
1970 void
1971 mark_referenced (tree id)
1973 TREE_SYMBOL_REFERENCED (id) = 1;
1976 /* Set the symbol_referenced flag for DECL and notify callgraph. */
1977 void
1978 mark_decl_referenced (tree decl)
1980 if (TREE_CODE (decl) == FUNCTION_DECL)
1982 /* Extern inline functions don't become needed when referenced. */
1983 if (!DECL_EXTERNAL (decl))
1984 cgraph_mark_needed_node (cgraph_node (decl));
1986 else if (TREE_CODE (decl) == VAR_DECL)
1988 struct cgraph_varpool_node *node = cgraph_varpool_node (decl);
1989 cgraph_varpool_mark_needed_node (node);
1990 /* C++ frontend use mark_decl_references to force COMDAT variables
1991 to be output that might appear dead otherwise. */
1992 node->force_output = true;
1994 /* else do nothing - we can get various sorts of CST nodes here,
1995 which do not need to be marked. */
1998 /* Output to FILE (an assembly file) a reference to NAME. If NAME
1999 starts with a *, the rest of NAME is output verbatim. Otherwise
2000 NAME is transformed in a target-specific way (usually by the
2001 addition of an underscore). */
2003 void
2004 assemble_name_raw (FILE *file, const char *name)
2006 if (name[0] == '*')
2007 fputs (&name[1], file);
2008 else
2009 ASM_OUTPUT_LABELREF (file, name);
2012 /* Like assemble_name_raw, but should be used when NAME might refer to
2013 an entity that is also represented as a tree (like a function or
2014 variable). If NAME does refer to such an entity, that entity will
2015 be marked as referenced. */
2017 void
2018 assemble_name (FILE *file, const char *name)
2020 const char *real_name;
2021 tree id;
2023 real_name = targetm.strip_name_encoding (name);
2025 id = maybe_get_identifier (real_name);
2026 if (id)
2027 mark_referenced (id);
2029 assemble_name_raw (file, name);
2032 /* Allocate SIZE bytes writable static space with a gensym name
2033 and return an RTX to refer to its address. */
2036 assemble_static_space (unsigned HOST_WIDE_INT size)
2038 char name[12];
2039 const char *namestring;
2040 rtx x;
2042 #if 0
2043 if (flag_shared_data)
2044 data_section ();
2045 #endif
2047 ASM_GENERATE_INTERNAL_LABEL (name, "LF", const_labelno);
2048 ++const_labelno;
2049 namestring = ggc_strdup (name);
2051 x = gen_rtx_SYMBOL_REF (Pmode, namestring);
2052 SYMBOL_REF_FLAGS (x) = SYMBOL_FLAG_LOCAL;
2054 #ifdef ASM_OUTPUT_ALIGNED_DECL_LOCAL
2055 ASM_OUTPUT_ALIGNED_DECL_LOCAL (asm_out_file, NULL_TREE, name, size,
2056 BIGGEST_ALIGNMENT);
2057 #else
2058 #ifdef ASM_OUTPUT_ALIGNED_LOCAL
2059 ASM_OUTPUT_ALIGNED_LOCAL (asm_out_file, name, size, BIGGEST_ALIGNMENT);
2060 #else
2062 /* Round size up to multiple of BIGGEST_ALIGNMENT bits
2063 so that each uninitialized object starts on such a boundary. */
2064 /* Variable `rounded' might or might not be used in ASM_OUTPUT_LOCAL. */
2065 unsigned HOST_WIDE_INT rounded ATTRIBUTE_UNUSED
2066 = ((size + (BIGGEST_ALIGNMENT / BITS_PER_UNIT) - 1)
2067 / (BIGGEST_ALIGNMENT / BITS_PER_UNIT)
2068 * (BIGGEST_ALIGNMENT / BITS_PER_UNIT));
2069 ASM_OUTPUT_LOCAL (asm_out_file, name, size, rounded);
2071 #endif
2072 #endif
2073 return x;
2076 /* Assemble the static constant template for function entry trampolines.
2077 This is done at most once per compilation.
2078 Returns an RTX for the address of the template. */
2080 static GTY(()) rtx initial_trampoline;
2082 #ifdef TRAMPOLINE_TEMPLATE
2084 assemble_trampoline_template (void)
2086 char label[256];
2087 const char *name;
2088 int align;
2089 rtx symbol;
2091 if (initial_trampoline)
2092 return initial_trampoline;
2094 /* By default, put trampoline templates in read-only data section. */
2096 #ifdef TRAMPOLINE_SECTION
2097 TRAMPOLINE_SECTION ();
2098 #else
2099 readonly_data_section ();
2100 #endif
2102 /* Write the assembler code to define one. */
2103 align = floor_log2 (TRAMPOLINE_ALIGNMENT / BITS_PER_UNIT);
2104 if (align > 0)
2106 ASM_OUTPUT_ALIGN (asm_out_file, align);
2109 targetm.asm_out.internal_label (asm_out_file, "LTRAMP", 0);
2110 TRAMPOLINE_TEMPLATE (asm_out_file);
2112 /* Record the rtl to refer to it. */
2113 ASM_GENERATE_INTERNAL_LABEL (label, "LTRAMP", 0);
2114 name = ggc_strdup (label);
2115 symbol = gen_rtx_SYMBOL_REF (Pmode, name);
2116 SYMBOL_REF_FLAGS (symbol) = SYMBOL_FLAG_LOCAL;
2118 initial_trampoline = gen_rtx_MEM (BLKmode, symbol);
2119 set_mem_align (initial_trampoline, TRAMPOLINE_ALIGNMENT);
2121 return initial_trampoline;
2123 #endif
2125 /* A and B are either alignments or offsets. Return the minimum alignment
2126 that may be assumed after adding the two together. */
2128 static inline unsigned
2129 min_align (unsigned int a, unsigned int b)
2131 return (a | b) & -(a | b);
2134 /* Return the assembler directive for creating a given kind of integer
2135 object. SIZE is the number of bytes in the object and ALIGNED_P
2136 indicates whether it is known to be aligned. Return NULL if the
2137 assembly dialect has no such directive.
2139 The returned string should be printed at the start of a new line and
2140 be followed immediately by the object's initial value. */
2142 const char *
2143 integer_asm_op (int size, int aligned_p)
2145 struct asm_int_op *ops;
2147 if (aligned_p)
2148 ops = &targetm.asm_out.aligned_op;
2149 else
2150 ops = &targetm.asm_out.unaligned_op;
2152 switch (size)
2154 case 1:
2155 return targetm.asm_out.byte_op;
2156 case 2:
2157 return ops->hi;
2158 case 4:
2159 return ops->si;
2160 case 8:
2161 return ops->di;
2162 case 16:
2163 return ops->ti;
2164 default:
2165 return NULL;
2169 /* Use directive OP to assemble an integer object X. Print OP at the
2170 start of the line, followed immediately by the value of X. */
2172 void
2173 assemble_integer_with_op (const char *op, rtx x)
2175 fputs (op, asm_out_file);
2176 output_addr_const (asm_out_file, x);
2177 fputc ('\n', asm_out_file);
2180 /* The default implementation of the asm_out.integer target hook. */
2182 bool
2183 default_assemble_integer (rtx x ATTRIBUTE_UNUSED,
2184 unsigned int size ATTRIBUTE_UNUSED,
2185 int aligned_p ATTRIBUTE_UNUSED)
2187 const char *op = integer_asm_op (size, aligned_p);
2188 /* Avoid GAS bugs for large values. Specifically negative values whose
2189 absolute value fits in a bfd_vma, but not in a bfd_signed_vma. */
2190 if (size > UNITS_PER_WORD && size > POINTER_SIZE / BITS_PER_UNIT)
2191 return false;
2192 return op && (assemble_integer_with_op (op, x), true);
2195 /* Assemble the integer constant X into an object of SIZE bytes. ALIGN is
2196 the alignment of the integer in bits. Return 1 if we were able to output
2197 the constant, otherwise 0. If FORCE is nonzero, abort if we can't output
2198 the constant. */
2200 bool
2201 assemble_integer (rtx x, unsigned int size, unsigned int align, int force)
2203 int aligned_p;
2205 aligned_p = (align >= MIN (size * BITS_PER_UNIT, BIGGEST_ALIGNMENT));
2207 /* See if the target hook can handle this kind of object. */
2208 if (targetm.asm_out.integer (x, size, aligned_p))
2209 return true;
2211 /* If the object is a multi-byte one, try splitting it up. Split
2212 it into words it if is multi-word, otherwise split it into bytes. */
2213 if (size > 1)
2215 enum machine_mode omode, imode;
2216 unsigned int subalign;
2217 unsigned int subsize, i;
2219 subsize = size > UNITS_PER_WORD? UNITS_PER_WORD : 1;
2220 subalign = MIN (align, subsize * BITS_PER_UNIT);
2221 omode = mode_for_size (subsize * BITS_PER_UNIT, MODE_INT, 0);
2222 imode = mode_for_size (size * BITS_PER_UNIT, MODE_INT, 0);
2224 for (i = 0; i < size; i += subsize)
2226 rtx partial = simplify_subreg (omode, x, imode, i);
2227 if (!partial || !assemble_integer (partial, subsize, subalign, 0))
2228 break;
2230 if (i == size)
2231 return true;
2233 /* If we've printed some of it, but not all of it, there's no going
2234 back now. */
2235 gcc_assert (!i);
2238 gcc_assert (!force);
2240 return false;
2243 void
2244 assemble_real (REAL_VALUE_TYPE d, enum machine_mode mode, unsigned int align)
2246 long data[4];
2247 int i;
2248 int bitsize, nelts, nunits, units_per;
2250 /* This is hairy. We have a quantity of known size. real_to_target
2251 will put it into an array of *host* longs, 32 bits per element
2252 (even if long is more than 32 bits). We need to determine the
2253 number of array elements that are occupied (nelts) and the number
2254 of *target* min-addressable units that will be occupied in the
2255 object file (nunits). We cannot assume that 32 divides the
2256 mode's bitsize (size * BITS_PER_UNIT) evenly.
2258 size * BITS_PER_UNIT is used here to make sure that padding bits
2259 (which might appear at either end of the value; real_to_target
2260 will include the padding bits in its output array) are included. */
2262 nunits = GET_MODE_SIZE (mode);
2263 bitsize = nunits * BITS_PER_UNIT;
2264 nelts = CEIL (bitsize, 32);
2265 units_per = 32 / BITS_PER_UNIT;
2267 real_to_target (data, &d, mode);
2269 /* Put out the first word with the specified alignment. */
2270 assemble_integer (GEN_INT (data[0]), MIN (nunits, units_per), align, 1);
2271 nunits -= units_per;
2273 /* Subsequent words need only 32-bit alignment. */
2274 align = min_align (align, 32);
2276 for (i = 1; i < nelts; i++)
2278 assemble_integer (GEN_INT (data[i]), MIN (nunits, units_per), align, 1);
2279 nunits -= units_per;
2283 /* Given an expression EXP with a constant value,
2284 reduce it to the sum of an assembler symbol and an integer.
2285 Store them both in the structure *VALUE.
2286 Abort if EXP does not reduce. */
2288 struct addr_const GTY(())
2290 rtx base;
2291 HOST_WIDE_INT offset;
2294 static void
2295 decode_addr_const (tree exp, struct addr_const *value)
2297 tree target = TREE_OPERAND (exp, 0);
2298 int offset = 0;
2299 rtx x;
2301 while (1)
2303 if (TREE_CODE (target) == COMPONENT_REF
2304 && host_integerp (byte_position (TREE_OPERAND (target, 1)), 0))
2307 offset += int_byte_position (TREE_OPERAND (target, 1));
2308 target = TREE_OPERAND (target, 0);
2310 else if (TREE_CODE (target) == ARRAY_REF
2311 || TREE_CODE (target) == ARRAY_RANGE_REF)
2313 offset += (tree_low_cst (TYPE_SIZE_UNIT (TREE_TYPE (target)), 1)
2314 * tree_low_cst (TREE_OPERAND (target, 1), 0));
2315 target = TREE_OPERAND (target, 0);
2317 else
2318 break;
2321 switch (TREE_CODE (target))
2323 case VAR_DECL:
2324 case FUNCTION_DECL:
2325 x = DECL_RTL (target);
2326 break;
2328 case LABEL_DECL:
2329 x = gen_rtx_MEM (FUNCTION_MODE,
2330 gen_rtx_LABEL_REF (VOIDmode, force_label_rtx (target)));
2331 break;
2333 case REAL_CST:
2334 case STRING_CST:
2335 case COMPLEX_CST:
2336 case CONSTRUCTOR:
2337 case INTEGER_CST:
2338 x = output_constant_def (target, 1);
2339 break;
2341 default:
2342 gcc_unreachable ();
2345 gcc_assert (MEM_P (x));
2346 x = XEXP (x, 0);
2348 value->base = x;
2349 value->offset = offset;
2352 /* Uniquize all constants that appear in memory.
2353 Each constant in memory thus far output is recorded
2354 in `const_desc_table'. */
2356 struct constant_descriptor_tree GTY(())
2358 /* A MEM for the constant. */
2359 rtx rtl;
2361 /* The value of the constant. */
2362 tree value;
2365 static GTY((param_is (struct constant_descriptor_tree)))
2366 htab_t const_desc_htab;
2368 static struct constant_descriptor_tree * build_constant_desc (tree);
2369 static void maybe_output_constant_def_contents (struct constant_descriptor_tree *, int);
2371 /* Compute a hash code for a constant expression. */
2373 static hashval_t
2374 const_desc_hash (const void *ptr)
2376 return const_hash_1 (((struct constant_descriptor_tree *)ptr)->value);
2379 static hashval_t
2380 const_hash_1 (const tree exp)
2382 const char *p;
2383 hashval_t hi;
2384 int len, i;
2385 enum tree_code code = TREE_CODE (exp);
2387 /* Either set P and LEN to the address and len of something to hash and
2388 exit the switch or return a value. */
2390 switch (code)
2392 case INTEGER_CST:
2393 p = (char *) &TREE_INT_CST (exp);
2394 len = sizeof TREE_INT_CST (exp);
2395 break;
2397 case REAL_CST:
2398 return real_hash (TREE_REAL_CST_PTR (exp));
2400 case STRING_CST:
2401 p = TREE_STRING_POINTER (exp);
2402 len = TREE_STRING_LENGTH (exp);
2403 break;
2405 case COMPLEX_CST:
2406 return (const_hash_1 (TREE_REALPART (exp)) * 5
2407 + const_hash_1 (TREE_IMAGPART (exp)));
2409 case CONSTRUCTOR:
2411 tree link;
2413 hi = 5 + int_size_in_bytes (TREE_TYPE (exp));
2415 for (link = CONSTRUCTOR_ELTS (exp); link; link = TREE_CHAIN (link))
2416 if (TREE_VALUE (link))
2417 hi = hi * 603 + const_hash_1 (TREE_VALUE (link));
2419 return hi;
2422 case ADDR_EXPR:
2423 case FDESC_EXPR:
2425 struct addr_const value;
2427 decode_addr_const (exp, &value);
2428 switch (GET_CODE (value.base))
2430 case SYMBOL_REF:
2431 /* Don't hash the address of the SYMBOL_REF;
2432 only use the offset and the symbol name. */
2433 hi = value.offset;
2434 p = XSTR (value.base, 0);
2435 for (i = 0; p[i] != 0; i++)
2436 hi = ((hi * 613) + (unsigned) (p[i]));
2437 break;
2439 case LABEL_REF:
2440 hi = value.offset + CODE_LABEL_NUMBER (XEXP (value.base, 0)) * 13;
2441 break;
2443 default:
2444 gcc_unreachable ();
2447 return hi;
2449 case PLUS_EXPR:
2450 case MINUS_EXPR:
2451 return (const_hash_1 (TREE_OPERAND (exp, 0)) * 9
2452 + const_hash_1 (TREE_OPERAND (exp, 1)));
2454 case NOP_EXPR:
2455 case CONVERT_EXPR:
2456 case NON_LVALUE_EXPR:
2457 return const_hash_1 (TREE_OPERAND (exp, 0)) * 7 + 2;
2459 default:
2460 /* A language specific constant. Just hash the code. */
2461 return code;
2464 /* Compute hashing function. */
2465 hi = len;
2466 for (i = 0; i < len; i++)
2467 hi = ((hi * 613) + (unsigned) (p[i]));
2469 return hi;
2472 /* Wrapper of compare_constant, for the htab interface. */
2473 static int
2474 const_desc_eq (const void *p1, const void *p2)
2476 return compare_constant (((struct constant_descriptor_tree *)p1)->value,
2477 ((struct constant_descriptor_tree *)p2)->value);
2480 /* Compare t1 and t2, and return 1 only if they are known to result in
2481 the same bit pattern on output. */
2483 static int
2484 compare_constant (const tree t1, const tree t2)
2486 enum tree_code typecode;
2488 if (t1 == NULL_TREE)
2489 return t2 == NULL_TREE;
2490 if (t2 == NULL_TREE)
2491 return 0;
2493 if (TREE_CODE (t1) != TREE_CODE (t2))
2494 return 0;
2496 switch (TREE_CODE (t1))
2498 case INTEGER_CST:
2499 /* Integer constants are the same only if the same width of type. */
2500 if (TYPE_PRECISION (TREE_TYPE (t1)) != TYPE_PRECISION (TREE_TYPE (t2)))
2501 return 0;
2502 return tree_int_cst_equal (t1, t2);
2504 case REAL_CST:
2505 /* Real constants are the same only if the same width of type. */
2506 if (TYPE_PRECISION (TREE_TYPE (t1)) != TYPE_PRECISION (TREE_TYPE (t2)))
2507 return 0;
2509 return REAL_VALUES_IDENTICAL (TREE_REAL_CST (t1), TREE_REAL_CST (t2));
2511 case STRING_CST:
2512 if (TYPE_MODE (TREE_TYPE (t1)) != TYPE_MODE (TREE_TYPE (t2)))
2513 return 0;
2515 return (TREE_STRING_LENGTH (t1) == TREE_STRING_LENGTH (t2)
2516 && ! memcmp (TREE_STRING_POINTER (t1), TREE_STRING_POINTER (t2),
2517 TREE_STRING_LENGTH (t1)));
2519 case COMPLEX_CST:
2520 return (compare_constant (TREE_REALPART (t1), TREE_REALPART (t2))
2521 && compare_constant (TREE_IMAGPART (t1), TREE_IMAGPART (t2)));
2523 case CONSTRUCTOR:
2525 tree l1, l2;
2527 typecode = TREE_CODE (TREE_TYPE (t1));
2528 if (typecode != TREE_CODE (TREE_TYPE (t2)))
2529 return 0;
2531 if (typecode == ARRAY_TYPE)
2533 HOST_WIDE_INT size_1 = int_size_in_bytes (TREE_TYPE (t1));
2534 /* For arrays, check that the sizes all match. */
2535 if (TYPE_MODE (TREE_TYPE (t1)) != TYPE_MODE (TREE_TYPE (t2))
2536 || size_1 == -1
2537 || size_1 != int_size_in_bytes (TREE_TYPE (t2)))
2538 return 0;
2540 else
2542 /* For record and union constructors, require exact type
2543 equality. */
2544 if (TREE_TYPE (t1) != TREE_TYPE (t2))
2545 return 0;
2548 for (l1 = CONSTRUCTOR_ELTS (t1), l2 = CONSTRUCTOR_ELTS (t2);
2549 l1 && l2;
2550 l1 = TREE_CHAIN (l1), l2 = TREE_CHAIN (l2))
2552 /* Check that each value is the same... */
2553 if (! compare_constant (TREE_VALUE (l1), TREE_VALUE (l2)))
2554 return 0;
2555 /* ... and that they apply to the same fields! */
2556 if (typecode == ARRAY_TYPE)
2558 if (! compare_constant (TREE_PURPOSE (l1),
2559 TREE_PURPOSE (l2)))
2560 return 0;
2562 else
2564 if (TREE_PURPOSE (l1) != TREE_PURPOSE (l2))
2565 return 0;
2569 return l1 == NULL_TREE && l2 == NULL_TREE;
2572 case ADDR_EXPR:
2573 case FDESC_EXPR:
2575 struct addr_const value1, value2;
2577 decode_addr_const (t1, &value1);
2578 decode_addr_const (t2, &value2);
2579 return (value1.offset == value2.offset
2580 && strcmp (XSTR (value1.base, 0), XSTR (value2.base, 0)) == 0);
2583 case PLUS_EXPR:
2584 case MINUS_EXPR:
2585 case RANGE_EXPR:
2586 return (compare_constant (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0))
2587 && compare_constant(TREE_OPERAND (t1, 1), TREE_OPERAND (t2, 1)));
2589 case NOP_EXPR:
2590 case CONVERT_EXPR:
2591 case NON_LVALUE_EXPR:
2592 case VIEW_CONVERT_EXPR:
2593 return compare_constant (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
2595 default:
2597 tree nt1, nt2;
2598 nt1 = lang_hooks.expand_constant (t1);
2599 nt2 = lang_hooks.expand_constant (t2);
2600 if (nt1 != t1 || nt2 != t2)
2601 return compare_constant (nt1, nt2);
2602 else
2603 return 0;
2607 gcc_unreachable ();
2610 /* Make a copy of the whole tree structure for a constant. This
2611 handles the same types of nodes that compare_constant handles. */
2613 static tree
2614 copy_constant (tree exp)
2616 switch (TREE_CODE (exp))
2618 case ADDR_EXPR:
2619 /* For ADDR_EXPR, we do not want to copy the decl whose address
2620 is requested. We do want to copy constants though. */
2621 if (CONSTANT_CLASS_P (TREE_OPERAND (exp, 0)))
2622 return build1 (TREE_CODE (exp), TREE_TYPE (exp),
2623 copy_constant (TREE_OPERAND (exp, 0)));
2624 else
2625 return copy_node (exp);
2627 case INTEGER_CST:
2628 case REAL_CST:
2629 case STRING_CST:
2630 return copy_node (exp);
2632 case COMPLEX_CST:
2633 return build_complex (TREE_TYPE (exp),
2634 copy_constant (TREE_REALPART (exp)),
2635 copy_constant (TREE_IMAGPART (exp)));
2637 case PLUS_EXPR:
2638 case MINUS_EXPR:
2639 return build2 (TREE_CODE (exp), TREE_TYPE (exp),
2640 copy_constant (TREE_OPERAND (exp, 0)),
2641 copy_constant (TREE_OPERAND (exp, 1)));
2643 case NOP_EXPR:
2644 case CONVERT_EXPR:
2645 case NON_LVALUE_EXPR:
2646 case VIEW_CONVERT_EXPR:
2647 return build1 (TREE_CODE (exp), TREE_TYPE (exp),
2648 copy_constant (TREE_OPERAND (exp, 0)));
2650 case CONSTRUCTOR:
2652 tree copy = copy_node (exp);
2653 tree list = copy_list (CONSTRUCTOR_ELTS (exp));
2654 tree tail;
2656 CONSTRUCTOR_ELTS (copy) = list;
2657 for (tail = list; tail; tail = TREE_CHAIN (tail))
2658 TREE_VALUE (tail) = copy_constant (TREE_VALUE (tail));
2660 return copy;
2663 default:
2665 tree t = lang_hooks.expand_constant (exp);
2667 gcc_assert (t == exp);
2668 return copy_constant (t);
2673 /* Subroutine of output_constant_def:
2674 No constant equal to EXP is known to have been output.
2675 Make a constant descriptor to enter EXP in the hash table.
2676 Assign the label number and construct RTL to refer to the
2677 constant's location in memory.
2678 Caller is responsible for updating the hash table. */
2680 static struct constant_descriptor_tree *
2681 build_constant_desc (tree exp)
2683 rtx symbol;
2684 rtx rtl;
2685 char label[256];
2686 int labelno;
2687 struct constant_descriptor_tree *desc;
2689 desc = ggc_alloc (sizeof (*desc));
2690 desc->value = copy_constant (exp);
2692 /* Propagate marked-ness to copied constant. */
2693 if (flag_mudflap && mf_marked_p (exp))
2694 mf_mark (desc->value);
2696 /* Create a string containing the label name, in LABEL. */
2697 labelno = const_labelno++;
2698 ASM_GENERATE_INTERNAL_LABEL (label, "LC", labelno);
2700 /* We have a symbol name; construct the SYMBOL_REF and the MEM. */
2701 symbol = gen_rtx_SYMBOL_REF (Pmode, ggc_strdup (label));
2702 SYMBOL_REF_FLAGS (symbol) = SYMBOL_FLAG_LOCAL;
2703 SYMBOL_REF_DECL (symbol) = desc->value;
2704 TREE_CONSTANT_POOL_ADDRESS_P (symbol) = 1;
2706 rtl = gen_rtx_MEM (TYPE_MODE (TREE_TYPE (exp)), symbol);
2707 set_mem_attributes (rtl, exp, 1);
2708 set_mem_alias_set (rtl, 0);
2709 set_mem_alias_set (rtl, const_alias_set);
2711 /* Set flags or add text to the name to record information, such as
2712 that it is a local symbol. If the name is changed, the macro
2713 ASM_OUTPUT_LABELREF will have to know how to strip this
2714 information. This call might invalidate our local variable
2715 SYMBOL; we can't use it afterward. */
2717 targetm.encode_section_info (exp, rtl, true);
2719 desc->rtl = rtl;
2721 return desc;
2724 /* Return an rtx representing a reference to constant data in memory
2725 for the constant expression EXP.
2727 If assembler code for such a constant has already been output,
2728 return an rtx to refer to it.
2729 Otherwise, output such a constant in memory
2730 and generate an rtx for it.
2732 If DEFER is nonzero, this constant can be deferred and output only
2733 if referenced in the function after all optimizations.
2735 `const_desc_table' records which constants already have label strings. */
2738 output_constant_def (tree exp, int defer)
2740 struct constant_descriptor_tree *desc;
2741 struct constant_descriptor_tree key;
2742 void **loc;
2744 /* Look up EXP in the table of constant descriptors. If we didn't find
2745 it, create a new one. */
2746 key.value = exp;
2747 loc = htab_find_slot (const_desc_htab, &key, INSERT);
2749 desc = *loc;
2750 if (desc == 0)
2752 desc = build_constant_desc (exp);
2753 *loc = desc;
2756 maybe_output_constant_def_contents (desc, defer);
2757 return desc->rtl;
2760 /* Subroutine of output_constant_def: Decide whether or not we need to
2761 output the constant DESC now, and if so, do it. */
2762 static void
2763 maybe_output_constant_def_contents (struct constant_descriptor_tree *desc,
2764 int defer)
2766 rtx symbol = XEXP (desc->rtl, 0);
2767 tree exp = desc->value;
2769 if (flag_syntax_only)
2770 return;
2772 if (TREE_ASM_WRITTEN (exp))
2773 /* Already output; don't do it again. */
2774 return;
2776 /* We can always defer constants as long as the context allows
2777 doing so. */
2778 if (defer)
2780 /* Increment n_deferred_constants if it exists. It needs to be at
2781 least as large as the number of constants actually referred to
2782 by the function. If it's too small we'll stop looking too early
2783 and fail to emit constants; if it's too large we'll only look
2784 through the entire function when we could have stopped earlier. */
2785 if (cfun)
2786 n_deferred_constants++;
2787 return;
2790 output_constant_def_contents (symbol);
2793 /* We must output the constant data referred to by SYMBOL; do so. */
2795 static void
2796 output_constant_def_contents (rtx symbol)
2798 tree exp = SYMBOL_REF_DECL (symbol);
2799 const char *label = XSTR (symbol, 0);
2800 HOST_WIDE_INT size;
2802 /* Make sure any other constants whose addresses appear in EXP
2803 are assigned label numbers. */
2804 int reloc = compute_reloc_for_constant (exp);
2806 /* Align the location counter as required by EXP's data type. */
2807 unsigned int align = TYPE_ALIGN (TREE_TYPE (exp));
2808 #ifdef CONSTANT_ALIGNMENT
2809 align = CONSTANT_ALIGNMENT (exp, align);
2810 #endif
2812 output_addressed_constants (exp);
2814 /* We are no longer deferring this constant. */
2815 TREE_ASM_WRITTEN (exp) = 1;
2817 if (IN_NAMED_SECTION (exp))
2818 named_section (exp, NULL, reloc);
2819 else
2820 targetm.asm_out.select_section (exp, reloc, align);
2822 if (align > BITS_PER_UNIT)
2824 ASM_OUTPUT_ALIGN (asm_out_file, floor_log2 (align / BITS_PER_UNIT));
2827 size = int_size_in_bytes (TREE_TYPE (exp));
2828 if (TREE_CODE (exp) == STRING_CST)
2829 size = MAX (TREE_STRING_LENGTH (exp), size);
2831 /* Do any machine/system dependent processing of the constant. */
2832 #ifdef ASM_DECLARE_CONSTANT_NAME
2833 ASM_DECLARE_CONSTANT_NAME (asm_out_file, label, exp, size);
2834 #else
2835 /* Standard thing is just output label for the constant. */
2836 ASM_OUTPUT_LABEL (asm_out_file, label);
2837 #endif /* ASM_DECLARE_CONSTANT_NAME */
2839 /* Output the value of EXP. */
2840 output_constant (exp, size, align);
2841 if (flag_mudflap)
2842 mudflap_enqueue_constant (exp);
2845 /* Look up EXP in the table of constant descriptors. Return the rtl
2846 if it has been emitted, else null. */
2849 lookup_constant_def (tree exp)
2851 struct constant_descriptor_tree *desc;
2852 struct constant_descriptor_tree key;
2854 key.value = exp;
2855 desc = htab_find (const_desc_htab, &key);
2857 return (desc ? desc->rtl : NULL_RTX);
2860 /* Used in the hash tables to avoid outputting the same constant
2861 twice. Unlike 'struct constant_descriptor_tree', RTX constants
2862 are output once per function, not once per file. */
2863 /* ??? Only a few targets need per-function constant pools. Most
2864 can use one per-file pool. Should add a targetm bit to tell the
2865 difference. */
2867 struct rtx_constant_pool GTY(())
2869 /* Pointers to first and last constant in pool, as ordered by offset. */
2870 struct constant_descriptor_rtx *first;
2871 struct constant_descriptor_rtx *last;
2873 /* Hash facility for making memory-constants from constant rtl-expressions.
2874 It is used on RISC machines where immediate integer arguments and
2875 constant addresses are restricted so that such constants must be stored
2876 in memory. */
2877 htab_t GTY((param_is (struct constant_descriptor_rtx))) const_rtx_htab;
2878 htab_t GTY((param_is (struct constant_descriptor_rtx))) const_rtx_sym_htab;
2880 /* Current offset in constant pool (does not include any
2881 machine-specific header). */
2882 HOST_WIDE_INT offset;
2885 struct constant_descriptor_rtx GTY((chain_next ("%h.next")))
2887 struct constant_descriptor_rtx *next;
2888 rtx mem;
2889 rtx sym;
2890 rtx constant;
2891 HOST_WIDE_INT offset;
2892 hashval_t hash;
2893 enum machine_mode mode;
2894 unsigned int align;
2895 int labelno;
2896 int mark;
2899 /* Hash and compare functions for const_rtx_htab. */
2901 static hashval_t
2902 const_desc_rtx_hash (const void *ptr)
2904 const struct constant_descriptor_rtx *desc = ptr;
2905 return desc->hash;
2908 static int
2909 const_desc_rtx_eq (const void *a, const void *b)
2911 const struct constant_descriptor_rtx *x = a;
2912 const struct constant_descriptor_rtx *y = b;
2914 if (x->mode != y->mode)
2915 return 0;
2916 return rtx_equal_p (x->constant, y->constant);
2919 /* Hash and compare functions for const_rtx_sym_htab. */
2921 static hashval_t
2922 const_desc_rtx_sym_hash (const void *ptr)
2924 const struct constant_descriptor_rtx *desc = ptr;
2925 return htab_hash_string (XSTR (desc->sym, 0));
2928 static int
2929 const_desc_rtx_sym_eq (const void *a, const void *b)
2931 const struct constant_descriptor_rtx *x = a;
2932 const struct constant_descriptor_rtx *y = b;
2933 return XSTR (x->sym, 0) == XSTR (y->sym, 0);
2936 /* This is the worker function for const_rtx_hash, called via for_each_rtx. */
2938 static int
2939 const_rtx_hash_1 (rtx *xp, void *data)
2941 unsigned HOST_WIDE_INT hwi;
2942 enum machine_mode mode;
2943 enum rtx_code code;
2944 hashval_t h, *hp;
2945 rtx x;
2947 x = *xp;
2948 code = GET_CODE (x);
2949 mode = GET_MODE (x);
2950 h = (hashval_t) code * 1048573 + mode;
2952 switch (code)
2954 case CONST_INT:
2955 hwi = INTVAL (x);
2956 fold_hwi:
2958 const int shift = sizeof (hashval_t) * CHAR_BIT;
2959 const int n = sizeof (HOST_WIDE_INT) / sizeof (hashval_t);
2960 int i;
2962 h ^= (hashval_t) hwi;
2963 for (i = 1; i < n; ++i)
2965 hwi >>= shift;
2966 h ^= (hashval_t) hwi;
2969 break;
2971 case CONST_DOUBLE:
2972 if (mode == VOIDmode)
2974 hwi = CONST_DOUBLE_LOW (x) ^ CONST_DOUBLE_HIGH (x);
2975 goto fold_hwi;
2977 else
2978 h ^= real_hash (CONST_DOUBLE_REAL_VALUE (x));
2979 break;
2981 case CONST_VECTOR:
2983 int i;
2984 for (i = XVECLEN (x, 0); i-- > 0; )
2985 h = h * 251 + const_rtx_hash_1 (&XVECEXP (x, 0, i), data);
2987 break;
2989 case SYMBOL_REF:
2990 h ^= htab_hash_string (XSTR (x, 0));
2991 break;
2993 case LABEL_REF:
2994 h = h * 251 + CODE_LABEL_NUMBER (XEXP (x, 0));
2995 break;
2997 case UNSPEC:
2998 case UNSPEC_VOLATILE:
2999 h = h * 251 + XINT (x, 1);
3000 break;
3002 default:
3003 break;
3006 hp = data;
3007 *hp = *hp * 509 + h;
3008 return 0;
3011 /* Compute a hash value for X, which should be a constant. */
3013 static hashval_t
3014 const_rtx_hash (rtx x)
3016 hashval_t h = 0;
3017 for_each_rtx (&x, const_rtx_hash_1, &h);
3018 return h;
3022 /* Initialize constant pool hashing for a new function. */
3024 void
3025 init_varasm_status (struct function *f)
3027 struct varasm_status *p;
3028 struct rtx_constant_pool *pool;
3030 p = ggc_alloc (sizeof (struct varasm_status));
3031 f->varasm = p;
3033 pool = ggc_alloc (sizeof (struct rtx_constant_pool));
3034 p->pool = pool;
3035 p->deferred_constants = 0;
3037 pool->const_rtx_htab = htab_create_ggc (31, const_desc_rtx_hash,
3038 const_desc_rtx_eq, NULL);
3039 pool->const_rtx_sym_htab = htab_create_ggc (31, const_desc_rtx_sym_hash,
3040 const_desc_rtx_sym_eq, NULL);
3041 pool->first = pool->last = NULL;
3042 pool->offset = 0;
3045 /* Given a MINUS expression, simplify it if both sides
3046 include the same symbol. */
3049 simplify_subtraction (rtx x)
3051 rtx r = simplify_rtx (x);
3052 return r ? r : x;
3055 /* Given a constant rtx X, make (or find) a memory constant for its value
3056 and return a MEM rtx to refer to it in memory. */
3059 force_const_mem (enum machine_mode mode, rtx x)
3061 struct constant_descriptor_rtx *desc, tmp;
3062 struct rtx_constant_pool *pool = cfun->varasm->pool;
3063 char label[256];
3064 rtx def, symbol;
3065 hashval_t hash;
3066 unsigned int align;
3067 void **slot;
3069 /* If we're not allowed to drop X into the constant pool, don't. */
3070 if (targetm.cannot_force_const_mem (x))
3071 return NULL_RTX;
3073 /* Lookup the value in the hashtable. */
3074 tmp.constant = x;
3075 tmp.mode = mode;
3076 hash = const_rtx_hash (x);
3077 slot = htab_find_slot_with_hash (pool->const_rtx_htab, &tmp, hash, INSERT);
3078 desc = *slot;
3080 /* If the constant was already present, return its memory. */
3081 if (desc)
3082 return copy_rtx (desc->mem);
3084 /* Otherwise, create a new descriptor. */
3085 desc = ggc_alloc (sizeof (*desc));
3086 *slot = desc;
3088 /* Align the location counter as required by EXP's data type. */
3089 align = GET_MODE_ALIGNMENT (mode == VOIDmode ? word_mode : mode);
3090 #ifdef CONSTANT_ALIGNMENT
3092 tree type = lang_hooks.types.type_for_mode (mode, 0);
3093 if (type != NULL_TREE)
3094 align = CONSTANT_ALIGNMENT (make_tree (type, x), align);
3096 #endif
3098 pool->offset += (align / BITS_PER_UNIT) - 1;
3099 pool->offset &= ~ ((align / BITS_PER_UNIT) - 1);
3101 desc->next = NULL;
3102 desc->constant = tmp.constant;
3103 desc->offset = pool->offset;
3104 desc->hash = hash;
3105 desc->mode = mode;
3106 desc->align = align;
3107 desc->labelno = const_labelno;
3108 desc->mark = 0;
3110 pool->offset += GET_MODE_SIZE (mode);
3111 if (pool->last)
3112 pool->last->next = desc;
3113 else
3114 pool->first = pool->last = desc;
3115 pool->last = desc;
3117 /* Create a string containing the label name, in LABEL. */
3118 ASM_GENERATE_INTERNAL_LABEL (label, "LC", const_labelno);
3119 ++const_labelno;
3121 /* Construct the SYMBOL_REF. Make sure to mark it as belonging to
3122 the constants pool. */
3123 desc->sym = symbol = gen_rtx_SYMBOL_REF (Pmode, ggc_strdup (label));
3124 SYMBOL_REF_FLAGS (symbol) = SYMBOL_FLAG_LOCAL;
3125 CONSTANT_POOL_ADDRESS_P (symbol) = 1;
3126 current_function_uses_const_pool = 1;
3128 /* Insert the descriptor into the symbol cross-reference table too. */
3129 slot = htab_find_slot (pool->const_rtx_sym_htab, desc, INSERT);
3130 gcc_assert (!*slot);
3131 *slot = desc;
3133 /* Construct the MEM. */
3134 desc->mem = def = gen_const_mem (mode, symbol);
3135 set_mem_attributes (def, lang_hooks.types.type_for_mode (mode, 0), 1);
3136 set_mem_align (def, align);
3138 /* If we're dropping a label to the constant pool, make sure we
3139 don't delete it. */
3140 if (GET_CODE (x) == LABEL_REF)
3141 LABEL_PRESERVE_P (XEXP (x, 0)) = 1;
3143 return copy_rtx (def);
3146 /* Given a SYMBOL_REF with CONSTANT_POOL_ADDRESS_P true, return a pointer to
3147 the corresponding constant_descriptor_rtx structure. */
3149 static struct constant_descriptor_rtx *
3150 find_pool_constant (struct rtx_constant_pool *pool, rtx sym)
3152 struct constant_descriptor_rtx tmp;
3153 tmp.sym = sym;
3154 return htab_find (pool->const_rtx_sym_htab, &tmp);
3157 /* Given a constant pool SYMBOL_REF, return the corresponding constant. */
3160 get_pool_constant (rtx addr)
3162 return find_pool_constant (cfun->varasm->pool, addr)->constant;
3165 /* Given a constant pool SYMBOL_REF, return the corresponding constant
3166 and whether it has been output or not. */
3169 get_pool_constant_mark (rtx addr, bool *pmarked)
3171 struct constant_descriptor_rtx *desc;
3173 desc = find_pool_constant (cfun->varasm->pool, addr);
3174 *pmarked = (desc->mark != 0);
3175 return desc->constant;
3178 /* Likewise, but for the constant pool of a specific function. */
3181 get_pool_constant_for_function (struct function *f, rtx addr)
3183 return find_pool_constant (f->varasm->pool, addr)->constant;
3186 /* Similar, return the mode. */
3188 enum machine_mode
3189 get_pool_mode (rtx addr)
3191 return find_pool_constant (cfun->varasm->pool, addr)->mode;
3194 /* Return the size of the constant pool. */
3197 get_pool_size (void)
3199 return cfun->varasm->pool->offset;
3202 /* Worker function for output_constant_pool_1. Emit assembly for X
3203 in MODE with known alignment ALIGN. */
3205 static void
3206 output_constant_pool_2 (enum machine_mode mode, rtx x, unsigned int align)
3208 switch (GET_MODE_CLASS (mode))
3210 case MODE_FLOAT:
3212 REAL_VALUE_TYPE r;
3214 gcc_assert (GET_CODE (x) == CONST_DOUBLE);
3215 REAL_VALUE_FROM_CONST_DOUBLE (r, x);
3216 assemble_real (r, mode, align);
3217 break;
3220 case MODE_INT:
3221 case MODE_PARTIAL_INT:
3222 assemble_integer (x, GET_MODE_SIZE (mode), align, 1);
3223 break;
3225 case MODE_VECTOR_FLOAT:
3226 case MODE_VECTOR_INT:
3228 int i, units;
3229 enum machine_mode submode = GET_MODE_INNER (mode);
3230 unsigned int subalign = MIN (align, GET_MODE_BITSIZE (submode));
3232 gcc_assert (GET_CODE (x) == CONST_VECTOR);
3233 units = CONST_VECTOR_NUNITS (x);
3235 for (i = 0; i < units; i++)
3237 rtx elt = CONST_VECTOR_ELT (x, i);
3238 output_constant_pool_2 (submode, elt, i ? subalign : align);
3241 break;
3243 default:
3244 gcc_unreachable ();
3248 /* Worker function for output_constant_pool. Emit POOL. */
3250 static void
3251 output_constant_pool_1 (struct constant_descriptor_rtx *desc)
3253 rtx x, tmp;
3255 if (!desc->mark)
3256 return;
3257 x = desc->constant;
3259 /* See if X is a LABEL_REF (or a CONST referring to a LABEL_REF)
3260 whose CODE_LABEL has been deleted. This can occur if a jump table
3261 is eliminated by optimization. If so, write a constant of zero
3262 instead. Note that this can also happen by turning the
3263 CODE_LABEL into a NOTE. */
3264 /* ??? This seems completely and utterly wrong. Certainly it's
3265 not true for NOTE_INSN_DELETED_LABEL, but I disbelieve proper
3266 functioning even with INSN_DELETED_P and friends. */
3268 tmp = x;
3269 switch (GET_CODE (x))
3271 case CONST:
3272 if (GET_CODE (XEXP (x, 0)) != PLUS
3273 || GET_CODE (XEXP (XEXP (x, 0), 0)) != LABEL_REF)
3274 break;
3275 tmp = XEXP (XEXP (x, 0), 0);
3276 /* FALLTHRU */
3278 case LABEL_REF:
3279 tmp = XEXP (x, 0);
3280 gcc_assert (!INSN_DELETED_P (tmp));
3281 gcc_assert (!NOTE_P (tmp)
3282 || NOTE_LINE_NUMBER (tmp) != NOTE_INSN_DELETED);
3283 break;
3285 default:
3286 break;
3289 /* First switch to correct section. */
3290 targetm.asm_out.select_rtx_section (desc->mode, x, desc->align);
3292 #ifdef ASM_OUTPUT_SPECIAL_POOL_ENTRY
3293 ASM_OUTPUT_SPECIAL_POOL_ENTRY (asm_out_file, x, desc->mode,
3294 desc->align, desc->labelno, done);
3295 #endif
3297 assemble_align (desc->align);
3299 /* Output the label. */
3300 targetm.asm_out.internal_label (asm_out_file, "LC", desc->labelno);
3302 /* Output the data. */
3303 output_constant_pool_2 (desc->mode, x, desc->align);
3305 /* Make sure all constants in SECTION_MERGE and not SECTION_STRINGS
3306 sections have proper size. */
3307 if (desc->align > GET_MODE_BITSIZE (desc->mode)
3308 && in_section == in_named
3309 && get_named_section_flags (in_named_name) & SECTION_MERGE)
3310 assemble_align (desc->align);
3312 #ifdef ASM_OUTPUT_SPECIAL_POOL_ENTRY
3313 done:
3314 #endif
3315 return;
3318 /* Given a SYMBOL_REF CURRENT_RTX, mark it and all constants it refers
3319 to as used. Emit referenced deferred strings. This function can
3320 be used with for_each_rtx to mark all SYMBOL_REFs in an rtx. */
3322 static int
3323 mark_constant (rtx *current_rtx, void *data)
3325 struct rtx_constant_pool *pool = data;
3326 rtx x = *current_rtx;
3328 if (x == NULL_RTX || GET_CODE (x) != SYMBOL_REF)
3329 return 0;
3331 if (CONSTANT_POOL_ADDRESS_P (x))
3333 struct constant_descriptor_rtx *desc = find_pool_constant (pool, x);
3334 if (desc->mark == 0)
3336 desc->mark = 1;
3337 for_each_rtx (&desc->constant, mark_constant, pool);
3340 else if (TREE_CONSTANT_POOL_ADDRESS_P (x))
3342 tree exp = SYMBOL_REF_DECL (x);
3343 if (!TREE_ASM_WRITTEN (exp))
3345 n_deferred_constants--;
3346 output_constant_def_contents (x);
3350 return -1;
3353 /* Look through appropriate parts of INSN, marking all entries in the
3354 constant pool which are actually being used. Entries that are only
3355 referenced by other constants are also marked as used. Emit
3356 deferred strings that are used. */
3358 static void
3359 mark_constants (struct rtx_constant_pool *pool, rtx insn)
3361 if (!INSN_P (insn))
3362 return;
3364 /* Insns may appear inside a SEQUENCE. Only check the patterns of
3365 insns, not any notes that may be attached. We don't want to mark
3366 a constant just because it happens to appear in a REG_EQUIV note. */
3367 if (GET_CODE (PATTERN (insn)) == SEQUENCE)
3369 rtx seq = PATTERN (insn);
3370 int i, n = XVECLEN (seq, 0);
3371 for (i = 0; i < n; ++i)
3373 rtx subinsn = XVECEXP (seq, 0, i);
3374 if (INSN_P (subinsn))
3375 for_each_rtx (&PATTERN (subinsn), mark_constant, pool);
3378 else
3379 for_each_rtx (&PATTERN (insn), mark_constant, pool);
3382 /* Look through the instructions for this function, and mark all the
3383 entries in POOL which are actually being used. Emit deferred constants
3384 which have indeed been used. */
3386 static void
3387 mark_constant_pool (struct rtx_constant_pool *pool)
3389 rtx insn, link;
3391 if (pool->first == 0 && n_deferred_constants == 0)
3392 return;
3394 for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
3395 mark_constants (pool, insn);
3397 for (link = current_function_epilogue_delay_list;
3398 link;
3399 link = XEXP (link, 1))
3400 mark_constants (pool, XEXP (link, 0));
3403 /* Write all the constants in the constant pool. */
3405 void
3406 output_constant_pool (const char *fnname ATTRIBUTE_UNUSED,
3407 tree fndecl ATTRIBUTE_UNUSED)
3409 struct rtx_constant_pool *pool = cfun->varasm->pool;
3410 struct constant_descriptor_rtx *desc;
3412 /* It is possible for gcc to call force_const_mem and then to later
3413 discard the instructions which refer to the constant. In such a
3414 case we do not need to output the constant. */
3415 mark_constant_pool (pool);
3417 #ifdef ASM_OUTPUT_POOL_PROLOGUE
3418 ASM_OUTPUT_POOL_PROLOGUE (asm_out_file, fnname, fndecl, pool->offset);
3419 #endif
3421 for (desc = pool->first; desc ; desc = desc->next)
3422 output_constant_pool_1 (desc);
3424 #ifdef ASM_OUTPUT_POOL_EPILOGUE
3425 ASM_OUTPUT_POOL_EPILOGUE (asm_out_file, fnname, fndecl, pool->offset);
3426 #endif
3429 /* Determine what kind of relocations EXP may need. */
3432 compute_reloc_for_constant (tree exp)
3434 int reloc = 0, reloc2;
3435 tree tem;
3437 /* Give the front-end a chance to convert VALUE to something that
3438 looks more like a constant to the back-end. */
3439 exp = lang_hooks.expand_constant (exp);
3441 switch (TREE_CODE (exp))
3443 case ADDR_EXPR:
3444 case FDESC_EXPR:
3445 /* Go inside any operations that get_inner_reference can handle and see
3446 if what's inside is a constant: no need to do anything here for
3447 addresses of variables or functions. */
3448 for (tem = TREE_OPERAND (exp, 0); handled_component_p (tem);
3449 tem = TREE_OPERAND (tem, 0))
3452 if (TREE_PUBLIC (tem))
3453 reloc |= 2;
3454 else
3455 reloc |= 1;
3456 break;
3458 case PLUS_EXPR:
3459 reloc = compute_reloc_for_constant (TREE_OPERAND (exp, 0));
3460 reloc |= compute_reloc_for_constant (TREE_OPERAND (exp, 1));
3461 break;
3463 case MINUS_EXPR:
3464 reloc = compute_reloc_for_constant (TREE_OPERAND (exp, 0));
3465 reloc2 = compute_reloc_for_constant (TREE_OPERAND (exp, 1));
3466 /* The difference of two local labels is computable at link time. */
3467 if (reloc == 1 && reloc2 == 1)
3468 reloc = 0;
3469 else
3470 reloc |= reloc2;
3471 break;
3473 case NOP_EXPR:
3474 case CONVERT_EXPR:
3475 case NON_LVALUE_EXPR:
3476 reloc = compute_reloc_for_constant (TREE_OPERAND (exp, 0));
3477 break;
3479 case CONSTRUCTOR:
3480 for (tem = CONSTRUCTOR_ELTS (exp); tem; tem = TREE_CHAIN (tem))
3481 if (TREE_VALUE (tem) != 0)
3482 reloc |= compute_reloc_for_constant (TREE_VALUE (tem));
3484 break;
3486 default:
3487 break;
3489 return reloc;
3492 /* Find all the constants whose addresses are referenced inside of EXP,
3493 and make sure assembler code with a label has been output for each one.
3494 Indicate whether an ADDR_EXPR has been encountered. */
3496 static void
3497 output_addressed_constants (tree exp)
3499 tree tem;
3501 /* Give the front-end a chance to convert VALUE to something that
3502 looks more like a constant to the back-end. */
3503 exp = lang_hooks.expand_constant (exp);
3505 switch (TREE_CODE (exp))
3507 case ADDR_EXPR:
3508 case FDESC_EXPR:
3509 /* Go inside any operations that get_inner_reference can handle and see
3510 if what's inside is a constant: no need to do anything here for
3511 addresses of variables or functions. */
3512 for (tem = TREE_OPERAND (exp, 0); handled_component_p (tem);
3513 tem = TREE_OPERAND (tem, 0))
3516 /* If we have an initialized CONST_DECL, retrieve the initializer. */
3517 if (TREE_CODE (tem) == CONST_DECL && DECL_INITIAL (tem))
3518 tem = DECL_INITIAL (tem);
3520 if (CONSTANT_CLASS_P (tem) || TREE_CODE (tem) == CONSTRUCTOR)
3521 output_constant_def (tem, 0);
3522 break;
3524 case PLUS_EXPR:
3525 case MINUS_EXPR:
3526 output_addressed_constants (TREE_OPERAND (exp, 1));
3527 /* Fall through. */
3529 case NOP_EXPR:
3530 case CONVERT_EXPR:
3531 case NON_LVALUE_EXPR:
3532 output_addressed_constants (TREE_OPERAND (exp, 0));
3533 break;
3535 case CONSTRUCTOR:
3536 for (tem = CONSTRUCTOR_ELTS (exp); tem; tem = TREE_CHAIN (tem))
3537 if (TREE_VALUE (tem) != 0)
3538 output_addressed_constants (TREE_VALUE (tem));
3540 break;
3542 default:
3543 break;
3547 /* Return nonzero if VALUE is a valid constant-valued expression
3548 for use in initializing a static variable; one that can be an
3549 element of a "constant" initializer.
3551 Return null_pointer_node if the value is absolute;
3552 if it is relocatable, return the variable that determines the relocation.
3553 We assume that VALUE has been folded as much as possible;
3554 therefore, we do not need to check for such things as
3555 arithmetic-combinations of integers. */
3557 tree
3558 initializer_constant_valid_p (tree value, tree endtype)
3560 /* Give the front-end a chance to convert VALUE to something that
3561 looks more like a constant to the back-end. */
3562 value = lang_hooks.expand_constant (value);
3564 switch (TREE_CODE (value))
3566 case CONSTRUCTOR:
3567 if ((TREE_CODE (TREE_TYPE (value)) == UNION_TYPE
3568 || TREE_CODE (TREE_TYPE (value)) == RECORD_TYPE)
3569 && TREE_CONSTANT (value)
3570 && CONSTRUCTOR_ELTS (value))
3572 tree elt;
3573 bool absolute = true;
3575 for (elt = CONSTRUCTOR_ELTS (value); elt; elt = TREE_CHAIN (elt))
3577 tree reloc;
3578 value = TREE_VALUE (elt);
3579 reloc = initializer_constant_valid_p (value, TREE_TYPE (value));
3580 if (!reloc)
3581 return NULL_TREE;
3582 if (reloc != null_pointer_node)
3583 absolute = false;
3585 /* For a non-absolute relocation, there is no single
3586 variable that can be "the variable that determines the
3587 relocation." */
3588 return absolute ? null_pointer_node : error_mark_node;
3591 return TREE_STATIC (value) ? null_pointer_node : NULL_TREE;
3593 case INTEGER_CST:
3594 case VECTOR_CST:
3595 case REAL_CST:
3596 case STRING_CST:
3597 case COMPLEX_CST:
3598 return null_pointer_node;
3600 case ADDR_EXPR:
3601 case FDESC_EXPR:
3602 value = staticp (TREE_OPERAND (value, 0));
3603 /* "&(*a).f" is like unto pointer arithmetic. If "a" turns out to
3604 be a constant, this is old-skool offsetof-like nonsense. */
3605 if (value
3606 && TREE_CODE (value) == INDIRECT_REF
3607 && TREE_CONSTANT (TREE_OPERAND (value, 0)))
3608 return null_pointer_node;
3609 /* Taking the address of a nested function involves a trampoline. */
3610 if (value
3611 && TREE_CODE (value) == FUNCTION_DECL
3612 && ((decl_function_context (value) && !DECL_NO_STATIC_CHAIN (value))
3613 || DECL_NON_ADDR_CONST_P (value)))
3614 return NULL_TREE;
3615 return value;
3617 case VIEW_CONVERT_EXPR:
3618 case NON_LVALUE_EXPR:
3619 return initializer_constant_valid_p (TREE_OPERAND (value, 0), endtype);
3621 case CONVERT_EXPR:
3622 case NOP_EXPR:
3624 tree src;
3625 tree src_type;
3626 tree dest_type;
3628 src = TREE_OPERAND (value, 0);
3629 src_type = TREE_TYPE (src);
3630 dest_type = TREE_TYPE (value);
3632 /* Allow conversions between pointer types, floating-point
3633 types, and offset types. */
3634 if ((POINTER_TYPE_P (dest_type) && POINTER_TYPE_P (src_type))
3635 || (FLOAT_TYPE_P (dest_type) && FLOAT_TYPE_P (src_type))
3636 || (TREE_CODE (dest_type) == OFFSET_TYPE
3637 && TREE_CODE (src_type) == OFFSET_TYPE))
3638 return initializer_constant_valid_p (src, endtype);
3640 /* Allow length-preserving conversions between integer types. */
3641 if (INTEGRAL_TYPE_P (dest_type) && INTEGRAL_TYPE_P (src_type)
3642 && (TYPE_PRECISION (dest_type) == TYPE_PRECISION (src_type)))
3643 return initializer_constant_valid_p (src, endtype);
3645 /* Allow conversions between other integer types only if
3646 explicit value. */
3647 if (INTEGRAL_TYPE_P (dest_type) && INTEGRAL_TYPE_P (src_type))
3649 tree inner = initializer_constant_valid_p (src, endtype);
3650 if (inner == null_pointer_node)
3651 return null_pointer_node;
3652 break;
3655 /* Allow (int) &foo provided int is as wide as a pointer. */
3656 if (INTEGRAL_TYPE_P (dest_type) && POINTER_TYPE_P (src_type)
3657 && (TYPE_PRECISION (dest_type) >= TYPE_PRECISION (src_type)))
3658 return initializer_constant_valid_p (src, endtype);
3660 /* Likewise conversions from int to pointers, but also allow
3661 conversions from 0. */
3662 if ((POINTER_TYPE_P (dest_type)
3663 || TREE_CODE (dest_type) == OFFSET_TYPE)
3664 && INTEGRAL_TYPE_P (src_type))
3666 if (integer_zerop (src))
3667 return null_pointer_node;
3668 else if (TYPE_PRECISION (dest_type) <= TYPE_PRECISION (src_type))
3669 return initializer_constant_valid_p (src, endtype);
3672 /* Allow conversions to struct or union types if the value
3673 inside is okay. */
3674 if (TREE_CODE (dest_type) == RECORD_TYPE
3675 || TREE_CODE (dest_type) == UNION_TYPE)
3676 return initializer_constant_valid_p (src, endtype);
3678 break;
3680 case PLUS_EXPR:
3681 if (! INTEGRAL_TYPE_P (endtype)
3682 || TYPE_PRECISION (endtype) >= POINTER_SIZE)
3684 tree valid0 = initializer_constant_valid_p (TREE_OPERAND (value, 0),
3685 endtype);
3686 tree valid1 = initializer_constant_valid_p (TREE_OPERAND (value, 1),
3687 endtype);
3688 /* If either term is absolute, use the other terms relocation. */
3689 if (valid0 == null_pointer_node)
3690 return valid1;
3691 if (valid1 == null_pointer_node)
3692 return valid0;
3694 break;
3696 case MINUS_EXPR:
3697 if (! INTEGRAL_TYPE_P (endtype)
3698 || TYPE_PRECISION (endtype) >= POINTER_SIZE)
3700 tree valid0 = initializer_constant_valid_p (TREE_OPERAND (value, 0),
3701 endtype);
3702 tree valid1 = initializer_constant_valid_p (TREE_OPERAND (value, 1),
3703 endtype);
3704 /* Win if second argument is absolute. */
3705 if (valid1 == null_pointer_node)
3706 return valid0;
3707 /* Win if both arguments have the same relocation.
3708 Then the value is absolute. */
3709 if (valid0 == valid1 && valid0 != 0)
3710 return null_pointer_node;
3712 /* Since GCC guarantees that string constants are unique in the
3713 generated code, a subtraction between two copies of the same
3714 constant string is absolute. */
3715 if (valid0 && TREE_CODE (valid0) == STRING_CST
3716 && valid1 && TREE_CODE (valid1) == STRING_CST
3717 && operand_equal_p (valid0, valid1, 1))
3718 return null_pointer_node;
3721 /* Support narrowing differences. */
3722 if (INTEGRAL_TYPE_P (endtype))
3724 tree op0, op1;
3726 op0 = TREE_OPERAND (value, 0);
3727 op1 = TREE_OPERAND (value, 1);
3729 /* Like STRIP_NOPS except allow the operand mode to widen.
3730 This works around a feature of fold that simplifies
3731 (int)(p1 - p2) to ((int)p1 - (int)p2) under the theory
3732 that the narrower operation is cheaper. */
3734 while (TREE_CODE (op0) == NOP_EXPR
3735 || TREE_CODE (op0) == CONVERT_EXPR
3736 || TREE_CODE (op0) == NON_LVALUE_EXPR)
3738 tree inner = TREE_OPERAND (op0, 0);
3739 if (inner == error_mark_node
3740 || ! INTEGRAL_MODE_P (TYPE_MODE (TREE_TYPE (inner)))
3741 || (GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op0)))
3742 > GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (inner)))))
3743 break;
3744 op0 = inner;
3747 while (TREE_CODE (op1) == NOP_EXPR
3748 || TREE_CODE (op1) == CONVERT_EXPR
3749 || TREE_CODE (op1) == NON_LVALUE_EXPR)
3751 tree inner = TREE_OPERAND (op1, 0);
3752 if (inner == error_mark_node
3753 || ! INTEGRAL_MODE_P (TYPE_MODE (TREE_TYPE (inner)))
3754 || (GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op1)))
3755 > GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (inner)))))
3756 break;
3757 op1 = inner;
3760 op0 = initializer_constant_valid_p (op0, endtype);
3761 op1 = initializer_constant_valid_p (op1, endtype);
3763 /* Both initializers must be known. */
3764 if (op0 && op1)
3766 if (op0 == op1)
3767 return null_pointer_node;
3769 /* Support differences between labels. */
3770 if (TREE_CODE (op0) == LABEL_DECL
3771 && TREE_CODE (op1) == LABEL_DECL)
3772 return null_pointer_node;
3774 if (TREE_CODE (op0) == STRING_CST
3775 && TREE_CODE (op1) == STRING_CST
3776 && operand_equal_p (op0, op1, 1))
3777 return null_pointer_node;
3780 break;
3782 default:
3783 break;
3786 return 0;
3789 /* Output assembler code for constant EXP to FILE, with no label.
3790 This includes the pseudo-op such as ".int" or ".byte", and a newline.
3791 Assumes output_addressed_constants has been done on EXP already.
3793 Generate exactly SIZE bytes of assembler data, padding at the end
3794 with zeros if necessary. SIZE must always be specified.
3796 SIZE is important for structure constructors,
3797 since trailing members may have been omitted from the constructor.
3798 It is also important for initialization of arrays from string constants
3799 since the full length of the string constant might not be wanted.
3800 It is also needed for initialization of unions, where the initializer's
3801 type is just one member, and that may not be as long as the union.
3803 There a case in which we would fail to output exactly SIZE bytes:
3804 for a structure constructor that wants to produce more than SIZE bytes.
3805 But such constructors will never be generated for any possible input.
3807 ALIGN is the alignment of the data in bits. */
3809 void
3810 output_constant (tree exp, unsigned HOST_WIDE_INT size, unsigned int align)
3812 enum tree_code code;
3813 unsigned HOST_WIDE_INT thissize;
3815 /* Some front-ends use constants other than the standard language-independent
3816 varieties, but which may still be output directly. Give the front-end a
3817 chance to convert EXP to a language-independent representation. */
3818 exp = lang_hooks.expand_constant (exp);
3820 if (size == 0 || flag_syntax_only)
3821 return;
3823 /* Eliminate any conversions since we'll be outputting the underlying
3824 constant. */
3825 while (TREE_CODE (exp) == NOP_EXPR || TREE_CODE (exp) == CONVERT_EXPR
3826 || TREE_CODE (exp) == NON_LVALUE_EXPR
3827 || TREE_CODE (exp) == VIEW_CONVERT_EXPR)
3828 exp = TREE_OPERAND (exp, 0);
3830 code = TREE_CODE (TREE_TYPE (exp));
3831 thissize = int_size_in_bytes (TREE_TYPE (exp));
3833 /* Allow a constructor with no elements for any data type.
3834 This means to fill the space with zeros. */
3835 if (TREE_CODE (exp) == CONSTRUCTOR && CONSTRUCTOR_ELTS (exp) == 0)
3837 assemble_zeros (size);
3838 return;
3841 if (TREE_CODE (exp) == FDESC_EXPR)
3843 #ifdef ASM_OUTPUT_FDESC
3844 HOST_WIDE_INT part = tree_low_cst (TREE_OPERAND (exp, 1), 0);
3845 tree decl = TREE_OPERAND (exp, 0);
3846 ASM_OUTPUT_FDESC (asm_out_file, decl, part);
3847 #else
3848 gcc_unreachable ();
3849 #endif
3850 return;
3853 /* Now output the underlying data. If we've handling the padding, return.
3854 Otherwise, break and ensure SIZE is the size written. */
3855 switch (code)
3857 case CHAR_TYPE:
3858 case BOOLEAN_TYPE:
3859 case INTEGER_TYPE:
3860 case ENUMERAL_TYPE:
3861 case POINTER_TYPE:
3862 case REFERENCE_TYPE:
3863 case OFFSET_TYPE:
3864 if (! assemble_integer (expand_expr (exp, NULL_RTX, VOIDmode,
3865 EXPAND_INITIALIZER),
3866 MIN (size, thissize), align, 0))
3867 error ("initializer for integer value is too complicated");
3868 break;
3870 case REAL_TYPE:
3871 if (TREE_CODE (exp) != REAL_CST)
3872 error ("initializer for floating value is not a floating constant");
3874 assemble_real (TREE_REAL_CST (exp), TYPE_MODE (TREE_TYPE (exp)), align);
3875 break;
3877 case COMPLEX_TYPE:
3878 output_constant (TREE_REALPART (exp), thissize / 2, align);
3879 output_constant (TREE_IMAGPART (exp), thissize / 2,
3880 min_align (align, BITS_PER_UNIT * (thissize / 2)));
3881 break;
3883 case ARRAY_TYPE:
3884 case VECTOR_TYPE:
3885 switch (TREE_CODE (exp))
3887 case CONSTRUCTOR:
3888 output_constructor (exp, size, align);
3889 return;
3890 case STRING_CST:
3891 thissize = MIN ((unsigned HOST_WIDE_INT)TREE_STRING_LENGTH (exp),
3892 size);
3893 assemble_string (TREE_STRING_POINTER (exp), thissize);
3894 break;
3896 case VECTOR_CST:
3898 int elt_size;
3899 tree link;
3900 unsigned int nalign;
3901 enum machine_mode inner;
3903 inner = TYPE_MODE (TREE_TYPE (TREE_TYPE (exp)));
3904 nalign = MIN (align, GET_MODE_ALIGNMENT (inner));
3906 elt_size = GET_MODE_SIZE (inner);
3908 link = TREE_VECTOR_CST_ELTS (exp);
3909 output_constant (TREE_VALUE (link), elt_size, align);
3910 while ((link = TREE_CHAIN (link)) != NULL)
3911 output_constant (TREE_VALUE (link), elt_size, nalign);
3912 break;
3914 default:
3915 gcc_unreachable ();
3917 break;
3919 case RECORD_TYPE:
3920 case UNION_TYPE:
3921 gcc_assert (TREE_CODE (exp) == CONSTRUCTOR);
3922 output_constructor (exp, size, align);
3923 return;
3925 case ERROR_MARK:
3926 return;
3928 default:
3929 gcc_unreachable ();
3932 if (size > thissize)
3933 assemble_zeros (size - thissize);
3937 /* Subroutine of output_constructor, used for computing the size of
3938 arrays of unspecified length. VAL must be a CONSTRUCTOR of an array
3939 type with an unspecified upper bound. */
3941 static unsigned HOST_WIDE_INT
3942 array_size_for_constructor (tree val)
3944 tree max_index, i;
3946 /* This code used to attempt to handle string constants that are not
3947 arrays of single-bytes, but nothing else does, so there's no point in
3948 doing it here. */
3949 if (TREE_CODE (val) == STRING_CST)
3950 return TREE_STRING_LENGTH (val);
3952 max_index = NULL_TREE;
3953 for (i = CONSTRUCTOR_ELTS (val); i; i = TREE_CHAIN (i))
3955 tree index = TREE_PURPOSE (i);
3957 if (TREE_CODE (index) == RANGE_EXPR)
3958 index = TREE_OPERAND (index, 1);
3959 if (max_index == NULL_TREE || tree_int_cst_lt (max_index, index))
3960 max_index = index;
3963 if (max_index == NULL_TREE)
3964 return 0;
3966 /* Compute the total number of array elements. */
3967 i = size_binop (MINUS_EXPR, convert (sizetype, max_index),
3968 convert (sizetype,
3969 TYPE_MIN_VALUE (TYPE_DOMAIN (TREE_TYPE (val)))));
3970 i = size_binop (PLUS_EXPR, i, convert (sizetype, integer_one_node));
3972 /* Multiply by the array element unit size to find number of bytes. */
3973 i = size_binop (MULT_EXPR, i, TYPE_SIZE_UNIT (TREE_TYPE (TREE_TYPE (val))));
3975 return tree_low_cst (i, 1);
3978 /* Subroutine of output_constant, used for CONSTRUCTORs (aggregate constants).
3979 Generate at least SIZE bytes, padding if necessary. */
3981 static void
3982 output_constructor (tree exp, unsigned HOST_WIDE_INT size,
3983 unsigned int align)
3985 tree type = TREE_TYPE (exp);
3986 tree link, field = 0;
3987 tree min_index = 0;
3988 /* Number of bytes output or skipped so far.
3989 In other words, current position within the constructor. */
3990 HOST_WIDE_INT total_bytes = 0;
3991 /* Nonzero means BYTE contains part of a byte, to be output. */
3992 int byte_buffer_in_use = 0;
3993 int byte = 0;
3995 gcc_assert (HOST_BITS_PER_WIDE_INT >= BITS_PER_UNIT);
3997 if (TREE_CODE (type) == RECORD_TYPE)
3998 field = TYPE_FIELDS (type);
4000 if (TREE_CODE (type) == ARRAY_TYPE
4001 && TYPE_DOMAIN (type) != 0)
4002 min_index = TYPE_MIN_VALUE (TYPE_DOMAIN (type));
4004 /* As LINK goes through the elements of the constant,
4005 FIELD goes through the structure fields, if the constant is a structure.
4006 if the constant is a union, then we override this,
4007 by getting the field from the TREE_LIST element.
4008 But the constant could also be an array. Then FIELD is zero.
4010 There is always a maximum of one element in the chain LINK for unions
4011 (even if the initializer in a source program incorrectly contains
4012 more one). */
4013 for (link = CONSTRUCTOR_ELTS (exp);
4014 link;
4015 link = TREE_CHAIN (link),
4016 field = field ? TREE_CHAIN (field) : 0)
4018 tree val = TREE_VALUE (link);
4019 tree index = 0;
4021 /* The element in a union constructor specifies the proper field
4022 or index. */
4023 if ((TREE_CODE (type) == RECORD_TYPE || TREE_CODE (type) == UNION_TYPE
4024 || TREE_CODE (type) == QUAL_UNION_TYPE)
4025 && TREE_PURPOSE (link) != 0)
4026 field = TREE_PURPOSE (link);
4028 else if (TREE_CODE (type) == ARRAY_TYPE)
4029 index = TREE_PURPOSE (link);
4031 #ifdef ASM_COMMENT_START
4032 if (field && flag_verbose_asm)
4033 fprintf (asm_out_file, "%s %s:\n",
4034 ASM_COMMENT_START,
4035 DECL_NAME (field)
4036 ? IDENTIFIER_POINTER (DECL_NAME (field))
4037 : "<anonymous>");
4038 #endif
4040 /* Eliminate the marker that makes a cast not be an lvalue. */
4041 if (val != 0)
4042 STRIP_NOPS (val);
4044 if (index && TREE_CODE (index) == RANGE_EXPR)
4046 unsigned HOST_WIDE_INT fieldsize
4047 = int_size_in_bytes (TREE_TYPE (type));
4048 HOST_WIDE_INT lo_index = tree_low_cst (TREE_OPERAND (index, 0), 0);
4049 HOST_WIDE_INT hi_index = tree_low_cst (TREE_OPERAND (index, 1), 0);
4050 HOST_WIDE_INT index;
4051 unsigned int align2 = min_align (align, fieldsize * BITS_PER_UNIT);
4053 for (index = lo_index; index <= hi_index; index++)
4055 /* Output the element's initial value. */
4056 if (val == 0)
4057 assemble_zeros (fieldsize);
4058 else
4059 output_constant (val, fieldsize, align2);
4061 /* Count its size. */
4062 total_bytes += fieldsize;
4065 else if (field == 0 || !DECL_BIT_FIELD (field))
4067 /* An element that is not a bit-field. */
4069 unsigned HOST_WIDE_INT fieldsize;
4070 /* Since this structure is static,
4071 we know the positions are constant. */
4072 HOST_WIDE_INT pos = field ? int_byte_position (field) : 0;
4073 unsigned int align2;
4075 if (index != 0)
4076 pos = (tree_low_cst (TYPE_SIZE_UNIT (TREE_TYPE (val)), 1)
4077 * (tree_low_cst (index, 0) - tree_low_cst (min_index, 0)));
4079 /* Output any buffered-up bit-fields preceding this element. */
4080 if (byte_buffer_in_use)
4082 assemble_integer (GEN_INT (byte), 1, BITS_PER_UNIT, 1);
4083 total_bytes++;
4084 byte_buffer_in_use = 0;
4087 /* Advance to offset of this element.
4088 Note no alignment needed in an array, since that is guaranteed
4089 if each element has the proper size. */
4090 if ((field != 0 || index != 0) && pos != total_bytes)
4092 assemble_zeros (pos - total_bytes);
4093 total_bytes = pos;
4096 /* Find the alignment of this element. */
4097 align2 = min_align (align, BITS_PER_UNIT * pos);
4099 /* Determine size this element should occupy. */
4100 if (field)
4102 fieldsize = 0;
4104 /* If this is an array with an unspecified upper bound,
4105 the initializer determines the size. */
4106 /* ??? This ought to only checked if DECL_SIZE_UNIT is NULL,
4107 but we cannot do this until the deprecated support for
4108 initializing zero-length array members is removed. */
4109 if (TREE_CODE (TREE_TYPE (field)) == ARRAY_TYPE
4110 && TYPE_DOMAIN (TREE_TYPE (field))
4111 && ! TYPE_MAX_VALUE (TYPE_DOMAIN (TREE_TYPE (field))))
4113 fieldsize = array_size_for_constructor (val);
4114 /* Given a non-empty initialization, this field had
4115 better be last. */
4116 gcc_assert (!fieldsize || !TREE_CHAIN (field));
4118 else if (DECL_SIZE_UNIT (field))
4120 /* ??? This can't be right. If the decl size overflows
4121 a host integer we will silently emit no data. */
4122 if (host_integerp (DECL_SIZE_UNIT (field), 1))
4123 fieldsize = tree_low_cst (DECL_SIZE_UNIT (field), 1);
4126 else
4127 fieldsize = int_size_in_bytes (TREE_TYPE (type));
4129 /* Output the element's initial value. */
4130 if (val == 0)
4131 assemble_zeros (fieldsize);
4132 else
4133 output_constant (val, fieldsize, align2);
4135 /* Count its size. */
4136 total_bytes += fieldsize;
4138 else if (val != 0 && TREE_CODE (val) != INTEGER_CST)
4139 error ("invalid initial value for member %qs",
4140 IDENTIFIER_POINTER (DECL_NAME (field)));
4141 else
4143 /* Element that is a bit-field. */
4145 HOST_WIDE_INT next_offset = int_bit_position (field);
4146 HOST_WIDE_INT end_offset
4147 = (next_offset + tree_low_cst (DECL_SIZE (field), 1));
4149 if (val == 0)
4150 val = integer_zero_node;
4152 /* If this field does not start in this (or, next) byte,
4153 skip some bytes. */
4154 if (next_offset / BITS_PER_UNIT != total_bytes)
4156 /* Output remnant of any bit field in previous bytes. */
4157 if (byte_buffer_in_use)
4159 assemble_integer (GEN_INT (byte), 1, BITS_PER_UNIT, 1);
4160 total_bytes++;
4161 byte_buffer_in_use = 0;
4164 /* If still not at proper byte, advance to there. */
4165 if (next_offset / BITS_PER_UNIT != total_bytes)
4167 assemble_zeros (next_offset / BITS_PER_UNIT - total_bytes);
4168 total_bytes = next_offset / BITS_PER_UNIT;
4172 if (! byte_buffer_in_use)
4173 byte = 0;
4175 /* We must split the element into pieces that fall within
4176 separate bytes, and combine each byte with previous or
4177 following bit-fields. */
4179 /* next_offset is the offset n fbits from the beginning of
4180 the structure to the next bit of this element to be processed.
4181 end_offset is the offset of the first bit past the end of
4182 this element. */
4183 while (next_offset < end_offset)
4185 int this_time;
4186 int shift;
4187 HOST_WIDE_INT value;
4188 HOST_WIDE_INT next_byte = next_offset / BITS_PER_UNIT;
4189 HOST_WIDE_INT next_bit = next_offset % BITS_PER_UNIT;
4191 /* Advance from byte to byte
4192 within this element when necessary. */
4193 while (next_byte != total_bytes)
4195 assemble_integer (GEN_INT (byte), 1, BITS_PER_UNIT, 1);
4196 total_bytes++;
4197 byte = 0;
4200 /* Number of bits we can process at once
4201 (all part of the same byte). */
4202 this_time = MIN (end_offset - next_offset,
4203 BITS_PER_UNIT - next_bit);
4204 if (BYTES_BIG_ENDIAN)
4206 /* On big-endian machine, take the most significant bits
4207 first (of the bits that are significant)
4208 and put them into bytes from the most significant end. */
4209 shift = end_offset - next_offset - this_time;
4211 /* Don't try to take a bunch of bits that cross
4212 the word boundary in the INTEGER_CST. We can
4213 only select bits from the LOW or HIGH part
4214 not from both. */
4215 if (shift < HOST_BITS_PER_WIDE_INT
4216 && shift + this_time > HOST_BITS_PER_WIDE_INT)
4218 this_time = shift + this_time - HOST_BITS_PER_WIDE_INT;
4219 shift = HOST_BITS_PER_WIDE_INT;
4222 /* Now get the bits from the appropriate constant word. */
4223 if (shift < HOST_BITS_PER_WIDE_INT)
4224 value = TREE_INT_CST_LOW (val);
4225 else
4227 gcc_assert (shift < 2 * HOST_BITS_PER_WIDE_INT);
4228 value = TREE_INT_CST_HIGH (val);
4229 shift -= HOST_BITS_PER_WIDE_INT;
4232 /* Get the result. This works only when:
4233 1 <= this_time <= HOST_BITS_PER_WIDE_INT. */
4234 byte |= (((value >> shift)
4235 & (((HOST_WIDE_INT) 2 << (this_time - 1)) - 1))
4236 << (BITS_PER_UNIT - this_time - next_bit));
4238 else
4240 /* On little-endian machines,
4241 take first the least significant bits of the value
4242 and pack them starting at the least significant
4243 bits of the bytes. */
4244 shift = next_offset - int_bit_position (field);
4246 /* Don't try to take a bunch of bits that cross
4247 the word boundary in the INTEGER_CST. We can
4248 only select bits from the LOW or HIGH part
4249 not from both. */
4250 if (shift < HOST_BITS_PER_WIDE_INT
4251 && shift + this_time > HOST_BITS_PER_WIDE_INT)
4252 this_time = (HOST_BITS_PER_WIDE_INT - shift);
4254 /* Now get the bits from the appropriate constant word. */
4255 if (shift < HOST_BITS_PER_WIDE_INT)
4256 value = TREE_INT_CST_LOW (val);
4257 else
4259 gcc_assert (shift < 2 * HOST_BITS_PER_WIDE_INT);
4260 value = TREE_INT_CST_HIGH (val);
4261 shift -= HOST_BITS_PER_WIDE_INT;
4264 /* Get the result. This works only when:
4265 1 <= this_time <= HOST_BITS_PER_WIDE_INT. */
4266 byte |= (((value >> shift)
4267 & (((HOST_WIDE_INT) 2 << (this_time - 1)) - 1))
4268 << next_bit);
4271 next_offset += this_time;
4272 byte_buffer_in_use = 1;
4277 if (byte_buffer_in_use)
4279 assemble_integer (GEN_INT (byte), 1, BITS_PER_UNIT, 1);
4280 total_bytes++;
4283 if ((unsigned HOST_WIDE_INT)total_bytes < size)
4284 assemble_zeros (size - total_bytes);
4287 /* This TREE_LIST contains any weak symbol declarations waiting
4288 to be emitted. */
4289 static GTY(()) tree weak_decls;
4291 /* Mark DECL as weak. */
4293 static void
4294 mark_weak (tree decl)
4296 DECL_WEAK (decl) = 1;
4298 if (DECL_RTL_SET_P (decl)
4299 && MEM_P (DECL_RTL (decl))
4300 && XEXP (DECL_RTL (decl), 0)
4301 && GET_CODE (XEXP (DECL_RTL (decl), 0)) == SYMBOL_REF)
4302 SYMBOL_REF_WEAK (XEXP (DECL_RTL (decl), 0)) = 1;
4305 /* Merge weak status between NEWDECL and OLDDECL. */
4307 void
4308 merge_weak (tree newdecl, tree olddecl)
4310 if (DECL_WEAK (newdecl) == DECL_WEAK (olddecl))
4311 return;
4313 if (DECL_WEAK (newdecl))
4315 tree wd;
4317 /* NEWDECL is weak, but OLDDECL is not. */
4319 /* If we already output the OLDDECL, we're in trouble; we can't
4320 go back and make it weak. This error cannot caught in
4321 declare_weak because the NEWDECL and OLDDECL was not yet
4322 been merged; therefore, TREE_ASM_WRITTEN was not set. */
4323 if (TREE_ASM_WRITTEN (olddecl))
4324 error ("%Jweak declaration of %qD must precede definition",
4325 newdecl, newdecl);
4327 /* If we've already generated rtl referencing OLDDECL, we may
4328 have done so in a way that will not function properly with
4329 a weak symbol. */
4330 else if (TREE_USED (olddecl)
4331 && TREE_SYMBOL_REFERENCED (DECL_ASSEMBLER_NAME (olddecl)))
4332 warning ("%Jweak declaration of %qD after first use results "
4333 "in unspecified behavior", newdecl, newdecl);
4335 if (SUPPORTS_WEAK)
4337 /* We put the NEWDECL on the weak_decls list at some point.
4338 Replace it with the OLDDECL. */
4339 for (wd = weak_decls; wd; wd = TREE_CHAIN (wd))
4340 if (TREE_VALUE (wd) == newdecl)
4342 TREE_VALUE (wd) = olddecl;
4343 break;
4345 /* We may not find the entry on the list. If NEWDECL is a
4346 weak alias, then we will have already called
4347 globalize_decl to remove the entry; in that case, we do
4348 not need to do anything. */
4351 /* Make the OLDDECL weak; it's OLDDECL that we'll be keeping. */
4352 mark_weak (olddecl);
4354 else
4355 /* OLDDECL was weak, but NEWDECL was not explicitly marked as
4356 weak. Just update NEWDECL to indicate that it's weak too. */
4357 mark_weak (newdecl);
4360 /* Declare DECL to be a weak symbol. */
4362 void
4363 declare_weak (tree decl)
4365 if (! TREE_PUBLIC (decl))
4366 error ("%Jweak declaration of %qD must be public", decl, decl);
4367 else if (TREE_CODE (decl) == FUNCTION_DECL && TREE_ASM_WRITTEN (decl))
4368 error ("%Jweak declaration of %qD must precede definition", decl, decl);
4369 else if (SUPPORTS_WEAK)
4371 if (! DECL_WEAK (decl))
4372 weak_decls = tree_cons (NULL, decl, weak_decls);
4374 else
4375 warning ("%Jweak declaration of %qD not supported", decl, decl);
4377 mark_weak (decl);
4380 /* Emit any pending weak declarations. */
4382 void
4383 weak_finish (void)
4385 tree t;
4387 for (t = weak_decls; t; t = TREE_CHAIN (t))
4389 tree decl = TREE_VALUE (t);
4390 #if defined (ASM_WEAKEN_DECL) || defined (ASM_WEAKEN_LABEL)
4391 const char *const name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
4392 #endif
4394 if (! TREE_USED (decl))
4395 continue;
4397 #ifdef ASM_WEAKEN_DECL
4398 ASM_WEAKEN_DECL (asm_out_file, decl, name, NULL);
4399 #else
4400 #ifdef ASM_WEAKEN_LABEL
4401 ASM_WEAKEN_LABEL (asm_out_file, name);
4402 #else
4403 #ifdef ASM_OUTPUT_WEAK_ALIAS
4404 warning ("only weak aliases are supported in this configuration");
4405 return;
4406 #endif
4407 #endif
4408 #endif
4412 /* Emit the assembly bits to indicate that DECL is globally visible. */
4414 static void
4415 globalize_decl (tree decl)
4417 const char *name = XSTR (XEXP (DECL_RTL (decl), 0), 0);
4419 #if defined (ASM_WEAKEN_LABEL) || defined (ASM_WEAKEN_DECL)
4420 if (DECL_WEAK (decl))
4422 tree *p, t;
4424 #ifdef ASM_WEAKEN_DECL
4425 ASM_WEAKEN_DECL (asm_out_file, decl, name, 0);
4426 #else
4427 ASM_WEAKEN_LABEL (asm_out_file, name);
4428 #endif
4430 /* Remove this function from the pending weak list so that
4431 we do not emit multiple .weak directives for it. */
4432 for (p = &weak_decls; (t = *p) ; )
4434 if (DECL_ASSEMBLER_NAME (decl) == DECL_ASSEMBLER_NAME (TREE_VALUE (t)))
4435 *p = TREE_CHAIN (t);
4436 else
4437 p = &TREE_CHAIN (t);
4439 return;
4441 #elif defined(ASM_MAKE_LABEL_LINKONCE)
4442 if (DECL_ONE_ONLY (decl))
4443 ASM_MAKE_LABEL_LINKONCE (asm_out_file, name);
4444 #endif
4446 targetm.asm_out.globalize_label (asm_out_file, name);
4449 /* We have to be able to tell cgraph about the needed-ness of the target
4450 of an alias. This requires that the decl have been defined. Aliases
4451 that precede their definition have to be queued for later processing. */
4453 struct alias_pair GTY(())
4455 tree decl;
4456 tree target;
4458 typedef struct alias_pair *alias_pair;
4460 /* Define gc'd vector type. */
4461 DEF_VEC_GC_P(alias_pair);
4463 static GTY(()) VEC(alias_pair) *alias_pairs;
4465 /* Given an assembly name, find the decl it is associated with. At the
4466 same time, mark it needed for cgraph. */
4468 static tree
4469 find_decl_and_mark_needed (tree decl, tree target)
4471 struct cgraph_node *fnode = NULL;
4472 struct cgraph_varpool_node *vnode = NULL;
4474 /* C++ thunk emitting code produces aliases late in the game.
4475 Avoid confusing cgraph code in that case. */
4476 if (!cgraph_global_info_ready)
4478 if (TREE_CODE (decl) == FUNCTION_DECL)
4480 fnode = cgraph_node_for_asm (target);
4481 if (fnode == NULL)
4482 vnode = cgraph_varpool_node_for_asm (target);
4484 else
4486 vnode = cgraph_varpool_node_for_asm (target);
4487 if (vnode == NULL)
4488 fnode = cgraph_node_for_asm (target);
4492 if (fnode)
4494 cgraph_mark_needed_node (fnode);
4495 return fnode->decl;
4497 else if (vnode)
4499 cgraph_varpool_mark_needed_node (vnode);
4500 return vnode->decl;
4502 else
4503 return NULL_TREE;
4506 /* Output the assembler code for a define (equate) using ASM_OUTPUT_DEF
4507 or ASM_OUTPUT_DEF_FROM_DECLS. The function defines the symbol whose
4508 tree node is DECL to have the value of the tree node TARGET. */
4510 static void
4511 do_assemble_alias (tree decl, tree target ATTRIBUTE_UNUSED)
4513 TREE_ASM_WRITTEN (decl) = 1;
4514 TREE_ASM_WRITTEN (DECL_ASSEMBLER_NAME (decl)) = 1;
4516 #ifdef ASM_OUTPUT_DEF
4517 /* Make name accessible from other files, if appropriate. */
4519 if (TREE_PUBLIC (decl))
4521 globalize_decl (decl);
4522 maybe_assemble_visibility (decl);
4525 # ifdef ASM_OUTPUT_DEF_FROM_DECLS
4526 ASM_OUTPUT_DEF_FROM_DECLS (asm_out_file, decl, target);
4527 # else
4528 ASM_OUTPUT_DEF (asm_out_file,
4529 IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl)),
4530 IDENTIFIER_POINTER (target));
4531 # endif
4532 #elif defined (ASM_OUTPUT_WEAK_ALIAS) || defined (ASM_WEAKEN_DECL)
4534 const char *name;
4535 tree *p, t;
4537 name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
4538 # ifdef ASM_WEAKEN_DECL
4539 ASM_WEAKEN_DECL (asm_out_file, decl, name, IDENTIFIER_POINTER (target));
4540 # else
4541 ASM_OUTPUT_WEAK_ALIAS (asm_out_file, name, IDENTIFIER_POINTER (target));
4542 # endif
4543 /* Remove this function from the pending weak list so that
4544 we do not emit multiple .weak directives for it. */
4545 for (p = &weak_decls; (t = *p) ; )
4546 if (DECL_ASSEMBLER_NAME (decl) == DECL_ASSEMBLER_NAME (TREE_VALUE (t)))
4547 *p = TREE_CHAIN (t);
4548 else
4549 p = &TREE_CHAIN (t);
4551 #endif
4554 /* First pass of completing pending aliases. Make sure that cgraph knows
4555 which symbols will be required. */
4557 void
4558 finish_aliases_1 (void)
4560 unsigned i;
4561 alias_pair p;
4563 for (i = 0; VEC_iterate (alias_pair, alias_pairs, i, p); i++)
4565 tree target_decl;
4567 target_decl = find_decl_and_mark_needed (p->decl, p->target);
4568 if (target_decl == NULL)
4569 error ("%J%qD aliased to undefined symbol %qE",
4570 p->decl, p->decl, p->target);
4571 else if (DECL_EXTERNAL (target_decl))
4572 error ("%J%qD aliased to external symbol %qE",
4573 p->decl, p->decl, p->target);
4577 /* Second pass of completing pending aliases. Emit the actual assembly.
4578 This happens at the end of compilation and thus it is assured that the
4579 target symbol has been emitted. */
4581 void
4582 finish_aliases_2 (void)
4584 unsigned i;
4585 alias_pair p;
4587 for (i = 0; VEC_iterate (alias_pair, alias_pairs, i, p); i++)
4588 do_assemble_alias (p->decl, p->target);
4590 alias_pairs = NULL;
4593 /* Emit an assembler directive to make the symbol for DECL an alias to
4594 the symbol for TARGET. */
4596 void
4597 assemble_alias (tree decl, tree target)
4599 tree target_decl;
4601 #if !defined (ASM_OUTPUT_DEF)
4602 # if !defined(ASM_OUTPUT_WEAK_ALIAS) && !defined (ASM_WEAKEN_DECL)
4603 error ("%Jalias definitions not supported in this configuration", decl);
4604 return;
4605 # else
4606 if (!DECL_WEAK (decl))
4608 error ("%Jonly weak aliases are supported in this configuration", decl);
4609 return;
4611 # endif
4612 #endif
4614 /* We must force creation of DECL_RTL for debug info generation, even though
4615 we don't use it here. */
4616 make_decl_rtl (decl);
4617 TREE_USED (decl) = 1;
4619 /* A quirk of the initial implementation of aliases required that the user
4620 add "extern" to all of them. Which is silly, but now historical. Do
4621 note that the symbol is in fact locally defined. */
4622 DECL_EXTERNAL (decl) = 0;
4624 /* Allow aliases to aliases. */
4625 if (TREE_CODE (decl) == FUNCTION_DECL)
4626 cgraph_node (decl)->alias = true;
4627 else
4628 cgraph_varpool_node (decl)->alias = true;
4630 /* If the target has already been emitted, we don't have to queue the
4631 alias. This saves a tad o memory. */
4632 target_decl = find_decl_and_mark_needed (decl, target);
4633 if (target_decl && TREE_ASM_WRITTEN (target_decl))
4634 do_assemble_alias (decl, target);
4635 else
4637 alias_pair p;
4639 p = ggc_alloc (sizeof (struct alias_pair));
4640 p->decl = decl;
4641 p->target = target;
4642 VEC_safe_push (alias_pair, alias_pairs, p);
4646 /* Emit an assembler directive to set symbol for DECL visibility to
4647 the visibility type VIS, which must not be VISIBILITY_DEFAULT. */
4649 void
4650 default_assemble_visibility (tree decl, int vis)
4652 static const char * const visibility_types[] = {
4653 NULL, "internal", "hidden", "protected"
4656 const char *name, *type;
4658 name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
4659 type = visibility_types[vis];
4661 #ifdef HAVE_GAS_HIDDEN
4662 fprintf (asm_out_file, "\t.%s\t", type);
4663 assemble_name (asm_out_file, name);
4664 fprintf (asm_out_file, "\n");
4665 #else
4666 warning ("visibility attribute not supported in this configuration; ignored");
4667 #endif
4670 /* A helper function to call assemble_visibility when needed for a decl. */
4672 static void
4673 maybe_assemble_visibility (tree decl)
4675 enum symbol_visibility vis = DECL_VISIBILITY (decl);
4677 if (vis != VISIBILITY_DEFAULT)
4678 targetm.asm_out.visibility (decl, vis);
4681 /* Returns 1 if the target configuration supports defining public symbols
4682 so that one of them will be chosen at link time instead of generating a
4683 multiply-defined symbol error, whether through the use of weak symbols or
4684 a target-specific mechanism for having duplicates discarded. */
4687 supports_one_only (void)
4689 if (SUPPORTS_ONE_ONLY)
4690 return 1;
4691 return SUPPORTS_WEAK;
4694 /* Set up DECL as a public symbol that can be defined in multiple
4695 translation units without generating a linker error. */
4697 void
4698 make_decl_one_only (tree decl)
4700 gcc_assert (TREE_CODE (decl) == VAR_DECL
4701 || TREE_CODE (decl) == FUNCTION_DECL);
4703 TREE_PUBLIC (decl) = 1;
4705 if (SUPPORTS_ONE_ONLY)
4707 #ifdef MAKE_DECL_ONE_ONLY
4708 MAKE_DECL_ONE_ONLY (decl);
4709 #endif
4710 DECL_ONE_ONLY (decl) = 1;
4712 else if (TREE_CODE (decl) == VAR_DECL
4713 && (DECL_INITIAL (decl) == 0 || DECL_INITIAL (decl) == error_mark_node))
4714 DECL_COMMON (decl) = 1;
4715 else
4717 gcc_assert (SUPPORTS_WEAK);
4718 DECL_WEAK (decl) = 1;
4722 void
4723 init_varasm_once (void)
4725 in_named_htab = htab_create_ggc (31, in_named_entry_hash,
4726 in_named_entry_eq, NULL);
4727 const_desc_htab = htab_create_ggc (1009, const_desc_hash,
4728 const_desc_eq, NULL);
4730 const_alias_set = new_alias_set ();
4733 static enum tls_model
4734 decl_tls_model (tree decl)
4736 enum tls_model kind;
4737 tree attr = lookup_attribute ("tls_model", DECL_ATTRIBUTES (decl));
4738 bool is_local;
4740 if (attr)
4742 attr = TREE_VALUE (TREE_VALUE (attr));
4743 gcc_assert (TREE_CODE (attr) == STRING_CST);
4745 if (!strcmp (TREE_STRING_POINTER (attr), "local-exec"))
4746 kind = TLS_MODEL_LOCAL_EXEC;
4747 else if (!strcmp (TREE_STRING_POINTER (attr), "initial-exec"))
4748 kind = TLS_MODEL_INITIAL_EXEC;
4749 else if (!strcmp (TREE_STRING_POINTER (attr), "local-dynamic"))
4750 kind = optimize ? TLS_MODEL_LOCAL_DYNAMIC : TLS_MODEL_GLOBAL_DYNAMIC;
4751 else if (!strcmp (TREE_STRING_POINTER (attr), "global-dynamic"))
4752 kind = TLS_MODEL_GLOBAL_DYNAMIC;
4753 else
4754 gcc_unreachable ();
4755 return kind;
4758 is_local = targetm.binds_local_p (decl);
4759 if (!flag_shlib)
4761 if (is_local)
4762 kind = TLS_MODEL_LOCAL_EXEC;
4763 else
4764 kind = TLS_MODEL_INITIAL_EXEC;
4766 /* Local dynamic is inefficient when we're not combining the
4767 parts of the address. */
4768 else if (optimize && is_local)
4769 kind = TLS_MODEL_LOCAL_DYNAMIC;
4770 else
4771 kind = TLS_MODEL_GLOBAL_DYNAMIC;
4772 if (kind < flag_tls_default)
4773 kind = flag_tls_default;
4775 return kind;
4778 /* Select a set of attributes for section NAME based on the properties
4779 of DECL and whether or not RELOC indicates that DECL's initializer
4780 might contain runtime relocations.
4782 We make the section read-only and executable for a function decl,
4783 read-only for a const data decl, and writable for a non-const data decl. */
4785 unsigned int
4786 default_section_type_flags (tree decl, const char *name, int reloc)
4788 return default_section_type_flags_1 (decl, name, reloc, flag_pic);
4791 unsigned int
4792 default_section_type_flags_1 (tree decl, const char *name, int reloc,
4793 int shlib)
4795 unsigned int flags;
4796 struct function *cfun = NULL;
4798 if (current_function_decl)
4799 cfun = DECL_STRUCT_FUNCTION (current_function_decl);
4801 if (decl && TREE_CODE (decl) == FUNCTION_DECL)
4802 flags = SECTION_CODE;
4803 else if (decl && decl_readonly_section_1 (decl, reloc, shlib))
4804 flags = 0;
4805 else if (current_function_decl
4806 && cfun->unlikely_text_section_name
4807 && strcmp (name, cfun->unlikely_text_section_name) == 0)
4808 flags = SECTION_CODE;
4809 else if (!decl
4810 && !current_function_decl
4811 && strcmp (name, UNLIKELY_EXECUTED_TEXT_SECTION_NAME) == 0)
4812 flags = SECTION_CODE;
4813 else
4814 flags = SECTION_WRITE;
4816 if (decl && DECL_ONE_ONLY (decl))
4817 flags |= SECTION_LINKONCE;
4819 if (decl && TREE_CODE (decl) == VAR_DECL && DECL_THREAD_LOCAL (decl))
4820 flags |= SECTION_TLS | SECTION_WRITE;
4822 if (strcmp (name, ".bss") == 0
4823 || strncmp (name, ".bss.", 5) == 0
4824 || strncmp (name, ".gnu.linkonce.b.", 16) == 0
4825 || strcmp (name, ".sbss") == 0
4826 || strncmp (name, ".sbss.", 6) == 0
4827 || strncmp (name, ".gnu.linkonce.sb.", 17) == 0)
4828 flags |= SECTION_BSS;
4830 if (strcmp (name, ".tdata") == 0
4831 || strncmp (name, ".tdata.", 7) == 0
4832 || strncmp (name, ".gnu.linkonce.td.", 17) == 0)
4833 flags |= SECTION_TLS;
4835 if (strcmp (name, ".tbss") == 0
4836 || strncmp (name, ".tbss.", 6) == 0
4837 || strncmp (name, ".gnu.linkonce.tb.", 17) == 0)
4838 flags |= SECTION_TLS | SECTION_BSS;
4840 /* These three sections have special ELF types. They are neither
4841 SHT_PROGBITS nor SHT_NOBITS, so when changing sections we don't
4842 want to print a section type (@progbits or @nobits). If someone
4843 is silly enough to emit code or TLS variables to one of these
4844 sections, then don't handle them specially. */
4845 if (!(flags & (SECTION_CODE | SECTION_BSS | SECTION_TLS))
4846 && (strcmp (name, ".init_array") == 0
4847 || strcmp (name, ".fini_array") == 0
4848 || strcmp (name, ".preinit_array") == 0))
4849 flags |= SECTION_NOTYPE;
4851 return flags;
4854 /* Output assembly to switch to section NAME with attribute FLAGS.
4855 Four variants for common object file formats. */
4857 void
4858 default_no_named_section (const char *name ATTRIBUTE_UNUSED,
4859 unsigned int flags ATTRIBUTE_UNUSED,
4860 tree decl ATTRIBUTE_UNUSED)
4862 /* Some object formats don't support named sections at all. The
4863 front-end should already have flagged this as an error. */
4864 gcc_unreachable ();
4867 void
4868 default_elf_asm_named_section (const char *name, unsigned int flags,
4869 tree decl ATTRIBUTE_UNUSED)
4871 char flagchars[10], *f = flagchars;
4873 /* If we have already declared this section, we can use an
4874 abbreviated form to switch back to it -- unless this section is
4875 part of a COMDAT groups, in which case GAS requires the full
4876 declaration every time. */
4877 if (!(HAVE_GAS_COMDAT_GROUP && (flags & SECTION_LINKONCE))
4878 && ! named_section_first_declaration (name))
4880 fprintf (asm_out_file, "\t.section\t%s\n", name);
4881 return;
4884 if (!(flags & SECTION_DEBUG))
4885 *f++ = 'a';
4886 if (flags & SECTION_WRITE)
4887 *f++ = 'w';
4888 if (flags & SECTION_CODE)
4889 *f++ = 'x';
4890 if (flags & SECTION_SMALL)
4891 *f++ = 's';
4892 if (flags & SECTION_MERGE)
4893 *f++ = 'M';
4894 if (flags & SECTION_STRINGS)
4895 *f++ = 'S';
4896 if (flags & SECTION_TLS)
4897 *f++ = 'T';
4898 if (HAVE_GAS_COMDAT_GROUP && (flags & SECTION_LINKONCE))
4899 *f++ = 'G';
4900 *f = '\0';
4902 fprintf (asm_out_file, "\t.section\t%s,\"%s\"", name, flagchars);
4904 if (!(flags & SECTION_NOTYPE))
4906 const char *type;
4907 const char *format;
4909 if (flags & SECTION_BSS)
4910 type = "nobits";
4911 else
4912 type = "progbits";
4914 format = ",@%s";
4915 #ifdef ASM_COMMENT_START
4916 /* On platforms that use "@" as the assembly comment character,
4917 use "%" instead. */
4918 if (strcmp (ASM_COMMENT_START, "@") == 0)
4919 format = ",%%%s";
4920 #endif
4921 fprintf (asm_out_file, format, type);
4923 if (flags & SECTION_ENTSIZE)
4924 fprintf (asm_out_file, ",%d", flags & SECTION_ENTSIZE);
4925 if (HAVE_GAS_COMDAT_GROUP && (flags & SECTION_LINKONCE))
4926 fprintf (asm_out_file, ",%s,comdat",
4927 lang_hooks.decls.comdat_group (decl));
4930 putc ('\n', asm_out_file);
4933 void
4934 default_coff_asm_named_section (const char *name, unsigned int flags,
4935 tree decl ATTRIBUTE_UNUSED)
4937 char flagchars[8], *f = flagchars;
4939 if (flags & SECTION_WRITE)
4940 *f++ = 'w';
4941 if (flags & SECTION_CODE)
4942 *f++ = 'x';
4943 *f = '\0';
4945 fprintf (asm_out_file, "\t.section\t%s,\"%s\"\n", name, flagchars);
4948 void
4949 default_pe_asm_named_section (const char *name, unsigned int flags,
4950 tree decl)
4952 default_coff_asm_named_section (name, flags, decl);
4954 if (flags & SECTION_LINKONCE)
4956 /* Functions may have been compiled at various levels of
4957 optimization so we can't use `same_size' here.
4958 Instead, have the linker pick one. */
4959 fprintf (asm_out_file, "\t.linkonce %s\n",
4960 (flags & SECTION_CODE ? "discard" : "same_size"));
4964 /* The lame default section selector. */
4966 void
4967 default_select_section (tree decl, int reloc,
4968 unsigned HOST_WIDE_INT align ATTRIBUTE_UNUSED)
4970 bool readonly = false;
4972 if (DECL_P (decl))
4974 if (decl_readonly_section (decl, reloc))
4975 readonly = true;
4977 else if (TREE_CODE (decl) == CONSTRUCTOR)
4979 if (! ((flag_pic && reloc)
4980 || !TREE_READONLY (decl)
4981 || TREE_SIDE_EFFECTS (decl)
4982 || !TREE_CONSTANT (decl)))
4983 readonly = true;
4985 else if (TREE_CODE (decl) == STRING_CST)
4986 readonly = true;
4987 else if (! (flag_pic && reloc))
4988 readonly = true;
4990 if (readonly)
4991 readonly_data_section ();
4992 else
4993 data_section ();
4996 /* A helper function for default_elf_select_section and
4997 default_elf_unique_section. Categorizes the DECL. */
4999 enum section_category
5001 SECCAT_TEXT,
5003 SECCAT_RODATA,
5004 SECCAT_RODATA_MERGE_STR,
5005 SECCAT_RODATA_MERGE_STR_INIT,
5006 SECCAT_RODATA_MERGE_CONST,
5007 SECCAT_SRODATA,
5009 SECCAT_DATA,
5011 /* To optimize loading of shared programs, define following subsections
5012 of data section:
5013 _REL Contains data that has relocations, so they get grouped
5014 together and dynamic linker will visit fewer pages in memory.
5015 _RO Contains data that is otherwise read-only. This is useful
5016 with prelinking as most relocations won't be dynamically
5017 linked and thus stay read only.
5018 _LOCAL Marks data containing relocations only to local objects.
5019 These relocations will get fully resolved by prelinking. */
5020 SECCAT_DATA_REL,
5021 SECCAT_DATA_REL_LOCAL,
5022 SECCAT_DATA_REL_RO,
5023 SECCAT_DATA_REL_RO_LOCAL,
5025 SECCAT_SDATA,
5026 SECCAT_TDATA,
5028 SECCAT_BSS,
5029 SECCAT_SBSS,
5030 SECCAT_TBSS
5033 static enum section_category
5034 categorize_decl_for_section (tree, int, int);
5036 static enum section_category
5037 categorize_decl_for_section (tree decl, int reloc, int shlib)
5039 enum section_category ret;
5041 if (TREE_CODE (decl) == FUNCTION_DECL)
5042 return SECCAT_TEXT;
5043 else if (TREE_CODE (decl) == STRING_CST)
5045 if (flag_mudflap) /* or !flag_merge_constants */
5046 return SECCAT_RODATA;
5047 else
5048 return SECCAT_RODATA_MERGE_STR;
5050 else if (TREE_CODE (decl) == VAR_DECL)
5052 if (DECL_INITIAL (decl) == NULL
5053 || DECL_INITIAL (decl) == error_mark_node
5054 || (flag_zero_initialized_in_bss
5055 /* Leave constant zeroes in .rodata so they can be shared. */
5056 && !TREE_READONLY (decl)
5057 && initializer_zerop (DECL_INITIAL (decl))))
5058 ret = SECCAT_BSS;
5059 else if (! TREE_READONLY (decl)
5060 || TREE_SIDE_EFFECTS (decl)
5061 || ! TREE_CONSTANT (DECL_INITIAL (decl)))
5063 if (shlib && (reloc & 2))
5064 ret = SECCAT_DATA_REL;
5065 else if (shlib && reloc)
5066 ret = SECCAT_DATA_REL_LOCAL;
5067 else
5068 ret = SECCAT_DATA;
5070 else if (shlib && (reloc & 2))
5071 ret = SECCAT_DATA_REL_RO;
5072 else if (shlib && reloc)
5073 ret = SECCAT_DATA_REL_RO_LOCAL;
5074 else if (reloc || flag_merge_constants < 2)
5075 /* C and C++ don't allow different variables to share the same
5076 location. -fmerge-all-constants allows even that (at the
5077 expense of not conforming). */
5078 ret = SECCAT_RODATA;
5079 else if (TREE_CODE (DECL_INITIAL (decl)) == STRING_CST)
5080 ret = SECCAT_RODATA_MERGE_STR_INIT;
5081 else
5082 ret = SECCAT_RODATA_MERGE_CONST;
5084 else if (TREE_CODE (decl) == CONSTRUCTOR)
5086 if ((shlib && reloc)
5087 || TREE_SIDE_EFFECTS (decl)
5088 || ! TREE_CONSTANT (decl))
5089 ret = SECCAT_DATA;
5090 else
5091 ret = SECCAT_RODATA;
5093 else
5094 ret = SECCAT_RODATA;
5096 /* There are no read-only thread-local sections. */
5097 if (TREE_CODE (decl) == VAR_DECL && DECL_THREAD_LOCAL (decl))
5099 /* Note that this would be *just* SECCAT_BSS, except that there's
5100 no concept of a read-only thread-local-data section. */
5101 if (ret == SECCAT_BSS
5102 || (flag_zero_initialized_in_bss
5103 && initializer_zerop (DECL_INITIAL (decl))))
5104 ret = SECCAT_TBSS;
5105 else
5106 ret = SECCAT_TDATA;
5109 /* If the target uses small data sections, select it. */
5110 else if (targetm.in_small_data_p (decl))
5112 if (ret == SECCAT_BSS)
5113 ret = SECCAT_SBSS;
5114 else if (targetm.have_srodata_section && ret == SECCAT_RODATA)
5115 ret = SECCAT_SRODATA;
5116 else
5117 ret = SECCAT_SDATA;
5120 return ret;
5123 bool
5124 decl_readonly_section (tree decl, int reloc)
5126 return decl_readonly_section_1 (decl, reloc, flag_pic);
5129 bool
5130 decl_readonly_section_1 (tree decl, int reloc, int shlib)
5132 switch (categorize_decl_for_section (decl, reloc, shlib))
5134 case SECCAT_RODATA:
5135 case SECCAT_RODATA_MERGE_STR:
5136 case SECCAT_RODATA_MERGE_STR_INIT:
5137 case SECCAT_RODATA_MERGE_CONST:
5138 case SECCAT_SRODATA:
5139 return true;
5140 break;
5141 default:
5142 return false;
5143 break;
5147 /* Select a section based on the above categorization. */
5149 void
5150 default_elf_select_section (tree decl, int reloc,
5151 unsigned HOST_WIDE_INT align)
5153 default_elf_select_section_1 (decl, reloc, align, flag_pic);
5156 void
5157 default_elf_select_section_1 (tree decl, int reloc,
5158 unsigned HOST_WIDE_INT align, int shlib)
5160 const char *sname;
5161 switch (categorize_decl_for_section (decl, reloc, shlib))
5163 case SECCAT_TEXT:
5164 /* We're not supposed to be called on FUNCTION_DECLs. */
5165 gcc_unreachable ();
5166 case SECCAT_RODATA:
5167 readonly_data_section ();
5168 return;
5169 case SECCAT_RODATA_MERGE_STR:
5170 mergeable_string_section (decl, align, 0);
5171 return;
5172 case SECCAT_RODATA_MERGE_STR_INIT:
5173 mergeable_string_section (DECL_INITIAL (decl), align, 0);
5174 return;
5175 case SECCAT_RODATA_MERGE_CONST:
5176 mergeable_constant_section (DECL_MODE (decl), align, 0);
5177 return;
5178 case SECCAT_SRODATA:
5179 sname = ".sdata2";
5180 break;
5181 case SECCAT_DATA:
5182 data_section ();
5183 return;
5184 case SECCAT_DATA_REL:
5185 sname = ".data.rel";
5186 break;
5187 case SECCAT_DATA_REL_LOCAL:
5188 sname = ".data.rel.local";
5189 break;
5190 case SECCAT_DATA_REL_RO:
5191 sname = ".data.rel.ro";
5192 break;
5193 case SECCAT_DATA_REL_RO_LOCAL:
5194 sname = ".data.rel.ro.local";
5195 break;
5196 case SECCAT_SDATA:
5197 sname = ".sdata";
5198 break;
5199 case SECCAT_TDATA:
5200 sname = ".tdata";
5201 break;
5202 case SECCAT_BSS:
5203 #ifdef BSS_SECTION_ASM_OP
5204 bss_section ();
5205 return;
5206 #else
5207 sname = ".bss";
5208 break;
5209 #endif
5210 case SECCAT_SBSS:
5211 sname = ".sbss";
5212 break;
5213 case SECCAT_TBSS:
5214 sname = ".tbss";
5215 break;
5216 default:
5217 gcc_unreachable ();
5220 if (!DECL_P (decl))
5221 decl = NULL_TREE;
5222 named_section (decl, sname, reloc);
5225 /* Construct a unique section name based on the decl name and the
5226 categorization performed above. */
5228 void
5229 default_unique_section (tree decl, int reloc)
5231 default_unique_section_1 (decl, reloc, flag_pic);
5234 void
5235 default_unique_section_1 (tree decl, int reloc, int shlib)
5237 bool one_only = DECL_ONE_ONLY (decl);
5238 const char *prefix, *name;
5239 size_t nlen, plen;
5240 char *string;
5242 switch (categorize_decl_for_section (decl, reloc, shlib))
5244 case SECCAT_TEXT:
5245 prefix = one_only ? ".gnu.linkonce.t." : ".text.";
5246 break;
5247 case SECCAT_RODATA:
5248 case SECCAT_RODATA_MERGE_STR:
5249 case SECCAT_RODATA_MERGE_STR_INIT:
5250 case SECCAT_RODATA_MERGE_CONST:
5251 prefix = one_only ? ".gnu.linkonce.r." : ".rodata.";
5252 break;
5253 case SECCAT_SRODATA:
5254 prefix = one_only ? ".gnu.linkonce.s2." : ".sdata2.";
5255 break;
5256 case SECCAT_DATA:
5257 case SECCAT_DATA_REL:
5258 case SECCAT_DATA_REL_LOCAL:
5259 case SECCAT_DATA_REL_RO:
5260 case SECCAT_DATA_REL_RO_LOCAL:
5261 prefix = one_only ? ".gnu.linkonce.d." : ".data.";
5262 break;
5263 case SECCAT_SDATA:
5264 prefix = one_only ? ".gnu.linkonce.s." : ".sdata.";
5265 break;
5266 case SECCAT_BSS:
5267 prefix = one_only ? ".gnu.linkonce.b." : ".bss.";
5268 break;
5269 case SECCAT_SBSS:
5270 prefix = one_only ? ".gnu.linkonce.sb." : ".sbss.";
5271 break;
5272 case SECCAT_TDATA:
5273 prefix = one_only ? ".gnu.linkonce.td." : ".tdata.";
5274 break;
5275 case SECCAT_TBSS:
5276 prefix = one_only ? ".gnu.linkonce.tb." : ".tbss.";
5277 break;
5278 default:
5279 gcc_unreachable ();
5281 plen = strlen (prefix);
5283 name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
5284 name = targetm.strip_name_encoding (name);
5285 nlen = strlen (name);
5287 string = alloca (nlen + plen + 1);
5288 memcpy (string, prefix, plen);
5289 memcpy (string + plen, name, nlen + 1);
5291 DECL_SECTION_NAME (decl) = build_string (nlen + plen, string);
5294 void
5295 default_select_rtx_section (enum machine_mode mode ATTRIBUTE_UNUSED,
5296 rtx x,
5297 unsigned HOST_WIDE_INT align ATTRIBUTE_UNUSED)
5299 if (flag_pic)
5300 switch (GET_CODE (x))
5302 case CONST:
5303 case SYMBOL_REF:
5304 case LABEL_REF:
5305 data_section ();
5306 return;
5308 default:
5309 break;
5312 readonly_data_section ();
5315 void
5316 default_elf_select_rtx_section (enum machine_mode mode, rtx x,
5317 unsigned HOST_WIDE_INT align)
5319 /* ??? Handle small data here somehow. */
5321 if (flag_pic)
5322 switch (GET_CODE (x))
5324 case CONST:
5325 case SYMBOL_REF:
5326 named_section (NULL_TREE, ".data.rel.ro", 3);
5327 return;
5329 case LABEL_REF:
5330 named_section (NULL_TREE, ".data.rel.ro.local", 1);
5331 return;
5333 default:
5334 break;
5337 mergeable_constant_section (mode, align, 0);
5340 /* Set the generally applicable flags on the SYMBOL_REF for EXP. */
5342 void
5343 default_encode_section_info (tree decl, rtx rtl, int first ATTRIBUTE_UNUSED)
5345 rtx symbol;
5346 int flags;
5348 /* Careful not to prod global register variables. */
5349 if (!MEM_P (rtl))
5350 return;
5351 symbol = XEXP (rtl, 0);
5352 if (GET_CODE (symbol) != SYMBOL_REF)
5353 return;
5355 flags = 0;
5356 if (TREE_CODE (decl) == FUNCTION_DECL)
5357 flags |= SYMBOL_FLAG_FUNCTION;
5358 if (targetm.binds_local_p (decl))
5359 flags |= SYMBOL_FLAG_LOCAL;
5360 if (TREE_CODE (decl) == VAR_DECL && DECL_THREAD_LOCAL (decl))
5361 flags |= decl_tls_model (decl) << SYMBOL_FLAG_TLS_SHIFT;
5362 else if (targetm.in_small_data_p (decl))
5363 flags |= SYMBOL_FLAG_SMALL;
5364 /* ??? Why is DECL_EXTERNAL ever set for non-PUBLIC names? Without
5365 being PUBLIC, the thing *must* be defined in this translation unit.
5366 Prevent this buglet from being propagated into rtl code as well. */
5367 if (DECL_P (decl) && DECL_EXTERNAL (decl) && TREE_PUBLIC (decl))
5368 flags |= SYMBOL_FLAG_EXTERNAL;
5370 SYMBOL_REF_FLAGS (symbol) = flags;
5373 /* By default, we do nothing for encode_section_info, so we need not
5374 do anything but discard the '*' marker. */
5376 const char *
5377 default_strip_name_encoding (const char *str)
5379 return str + (*str == '*');
5382 /* Assume ELF-ish defaults, since that's pretty much the most liberal
5383 wrt cross-module name binding. */
5385 bool
5386 default_binds_local_p (tree exp)
5388 return default_binds_local_p_1 (exp, flag_shlib);
5391 bool
5392 default_binds_local_p_1 (tree exp, int shlib)
5394 bool local_p;
5396 /* A non-decl is an entry in the constant pool. */
5397 if (!DECL_P (exp))
5398 local_p = true;
5399 /* Static variables are always local. */
5400 else if (! TREE_PUBLIC (exp))
5401 local_p = true;
5402 /* A variable is local if the user explicitly tells us so. */
5403 else if (DECL_VISIBILITY_SPECIFIED (exp) && DECL_VISIBILITY (exp) != VISIBILITY_DEFAULT)
5404 local_p = true;
5405 /* Otherwise, variables defined outside this object may not be local. */
5406 else if (DECL_EXTERNAL (exp))
5407 local_p = false;
5408 /* Linkonce and weak data are never local. */
5409 else if (DECL_ONE_ONLY (exp) || DECL_WEAK (exp))
5410 local_p = false;
5411 /* If none of the above and visibility is not default, make local. */
5412 else if (DECL_VISIBILITY (exp) != VISIBILITY_DEFAULT)
5413 local_p = true;
5414 /* If PIC, then assume that any global name can be overridden by
5415 symbols resolved from other modules. */
5416 else if (shlib)
5417 local_p = false;
5418 /* Uninitialized COMMON variable may be unified with symbols
5419 resolved from other modules. */
5420 else if (DECL_COMMON (exp)
5421 && (DECL_INITIAL (exp) == NULL
5422 || DECL_INITIAL (exp) == error_mark_node))
5423 local_p = false;
5424 /* Otherwise we're left with initialized (or non-common) global data
5425 which is of necessity defined locally. */
5426 else
5427 local_p = true;
5429 return local_p;
5432 /* Determine whether or not a pointer mode is valid. Assume defaults
5433 of ptr_mode or Pmode - can be overridden. */
5434 bool
5435 default_valid_pointer_mode (enum machine_mode mode)
5437 return (mode == ptr_mode || mode == Pmode);
5440 /* Default function to output code that will globalize a label. A
5441 target must define GLOBAL_ASM_OP or provide its own function to
5442 globalize a label. */
5443 #ifdef GLOBAL_ASM_OP
5444 void
5445 default_globalize_label (FILE * stream, const char *name)
5447 fputs (GLOBAL_ASM_OP, stream);
5448 assemble_name (stream, name);
5449 putc ('\n', stream);
5451 #endif /* GLOBAL_ASM_OP */
5453 /* Default function to output a label for unwind information. The
5454 default is to do nothing. A target that needs nonlocal labels for
5455 unwind information must provide its own function to do this. */
5456 void
5457 default_emit_unwind_label (FILE * stream ATTRIBUTE_UNUSED,
5458 tree decl ATTRIBUTE_UNUSED,
5459 int for_eh ATTRIBUTE_UNUSED,
5460 int empty ATTRIBUTE_UNUSED)
5464 /* This is how to output an internal numbered label where PREFIX is
5465 the class of label and LABELNO is the number within the class. */
5467 void
5468 default_internal_label (FILE *stream, const char *prefix,
5469 unsigned long labelno)
5471 char *const buf = alloca (40 + strlen (prefix));
5472 ASM_GENERATE_INTERNAL_LABEL (buf, prefix, labelno);
5473 ASM_OUTPUT_INTERNAL_LABEL (stream, buf);
5476 /* This is the default behavior at the beginning of a file. It's
5477 controlled by two other target-hook toggles. */
5478 void
5479 default_file_start (void)
5481 if (targetm.file_start_app_off && !flag_verbose_asm)
5482 fputs (ASM_APP_OFF, asm_out_file);
5484 if (targetm.file_start_file_directive)
5485 output_file_directive (asm_out_file, main_input_filename);
5488 /* This is a generic routine suitable for use as TARGET_ASM_FILE_END
5489 which emits a special section directive used to indicate whether or
5490 not this object file needs an executable stack. This is primarily
5491 a GNU extension to ELF but could be used on other targets. */
5493 int trampolines_created;
5495 void
5496 file_end_indicate_exec_stack (void)
5498 unsigned int flags = SECTION_DEBUG;
5499 if (trampolines_created)
5500 flags |= SECTION_CODE;
5502 named_section_flags (".note.GNU-stack", flags);
5505 #include "gt-varasm.h"