svn merge -r102224:107263 svn+ssh://gcc.gnu.org/svn/gcc/branches/gcc-3_4-branch
[official-gcc.git] / gcc / varasm.c
blob8e83d543191e3d899389bf4d8fa3cab5792041ec
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 Free Software Foundation, Inc.
5 This file is part of GCC.
7 GCC is free software; you can redistribute it and/or modify it under
8 the terms of the GNU General Public License as published by the Free
9 Software Foundation; either version 2, or (at your option) any later
10 version.
12 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
13 WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
15 for more details.
17 You should have received a copy of the GNU General Public License
18 along with GCC; see the file COPYING. If not, write to the Free
19 Software Foundation, 59 Temple Place - Suite 330, Boston, MA
20 02111-1307, USA. */
23 /* This file handles generation of all the assembler code
24 *except* the instructions of a function.
25 This includes declarations of variables and their initial values.
27 We also output the assembler code for constants stored in memory
28 and are responsible for combining constants with the same value. */
30 #include "config.h"
31 #include "system.h"
32 #include "coretypes.h"
33 #include "tm.h"
34 #include "rtl.h"
35 #include "tree.h"
36 #include "flags.h"
37 #include "function.h"
38 #include "expr.h"
39 #include "hard-reg-set.h"
40 #include "regs.h"
41 #include "real.h"
42 #include "output.h"
43 #include "toplev.h"
44 #include "hashtab.h"
45 #include "c-pragma.h"
46 #include "ggc.h"
47 #include "langhooks.h"
48 #include "tm_p.h"
49 #include "debug.h"
50 #include "target.h"
51 #include "cgraph.h"
53 #ifdef XCOFF_DEBUGGING_INFO
54 #include "xcoffout.h" /* Needed for external data
55 declarations for e.g. AIX 4.x. */
56 #endif
58 #ifndef TRAMPOLINE_ALIGNMENT
59 #define TRAMPOLINE_ALIGNMENT FUNCTION_BOUNDARY
60 #endif
62 #ifndef ASM_STABS_OP
63 #define ASM_STABS_OP "\t.stabs\t"
64 #endif
66 /* The (assembler) name of the first globally-visible object output. */
67 const char *first_global_object_name;
68 const char *weak_global_object_name;
70 struct addr_const;
71 struct constant_descriptor_rtx;
72 struct rtx_const;
73 struct pool_constant;
75 #define MAX_RTX_HASH_TABLE 61
77 struct varasm_status GTY(())
79 /* Hash facility for making memory-constants
80 from constant rtl-expressions. It is used on RISC machines
81 where immediate integer arguments and constant addresses are restricted
82 so that such constants must be stored in memory.
84 This pool of constants is reinitialized for each function
85 so each function gets its own constants-pool that comes right before
86 it. */
87 struct constant_descriptor_rtx ** GTY ((length ("MAX_RTX_HASH_TABLE")))
88 x_const_rtx_hash_table;
89 struct pool_constant ** GTY ((length ("MAX_RTX_HASH_TABLE")))
90 x_const_rtx_sym_hash_table;
92 /* Pointers to first and last constant in pool. */
93 struct pool_constant *x_first_pool;
94 struct pool_constant *x_last_pool;
96 /* Current offset in constant pool (does not include any machine-specific
97 header). */
98 HOST_WIDE_INT x_pool_offset;
100 /* Number of tree-constants deferred during the expansion of this
101 function. */
102 unsigned int deferred_constants;
105 #define const_rtx_hash_table (cfun->varasm->x_const_rtx_hash_table)
106 #define const_rtx_sym_hash_table (cfun->varasm->x_const_rtx_sym_hash_table)
107 #define first_pool (cfun->varasm->x_first_pool)
108 #define last_pool (cfun->varasm->x_last_pool)
109 #define pool_offset (cfun->varasm->x_pool_offset)
110 #define n_deferred_constants (cfun->varasm->deferred_constants)
112 /* Number for making the label on the next
113 constant that is stored in memory. */
115 static GTY(()) int const_labelno;
117 /* Carry information from ASM_DECLARE_OBJECT_NAME
118 to ASM_FINISH_DECLARE_OBJECT. */
120 int size_directive_output;
122 /* The last decl for which assemble_variable was called,
123 if it did ASM_DECLARE_OBJECT_NAME.
124 If the last call to assemble_variable didn't do that,
125 this holds 0. */
127 tree last_assemble_variable_decl;
129 /* RTX_UNCHANGING_P in a MEM can mean it is stored into, for initialization.
130 So giving constant the alias set for the type will allow such
131 initializations to appear to conflict with the load of the constant. We
132 avoid this by giving all constants an alias set for just constants.
133 Since there will be no stores to that alias set, nothing will ever
134 conflict with them. */
136 static HOST_WIDE_INT const_alias_set;
138 static const char *strip_reg_name (const char *);
139 static int contains_pointers_p (tree);
140 #ifdef ASM_OUTPUT_EXTERNAL
141 static bool incorporeal_function_p (tree);
142 #endif
143 static void decode_addr_const (tree, struct addr_const *);
144 static hashval_t const_desc_hash (const void *);
145 static int const_desc_eq (const void *, const void *);
146 static hashval_t const_hash_1 (const tree);
147 static int compare_constant (const tree, const tree);
148 static tree copy_constant (tree);
149 static void output_constant_def_contents (rtx);
150 static void decode_rtx_const (enum machine_mode, rtx, struct rtx_const *);
151 static unsigned int const_hash_rtx (enum machine_mode, rtx);
152 static int compare_constant_rtx (enum machine_mode, rtx,
153 struct constant_descriptor_rtx *);
154 static struct constant_descriptor_rtx * record_constant_rtx
155 (enum machine_mode, rtx);
156 static struct pool_constant *find_pool_constant (struct function *, rtx);
157 static void mark_constant_pool (void);
158 static void mark_constants (rtx);
159 static int mark_constant (rtx *current_rtx, void *data);
160 static void output_addressed_constants (tree);
161 static unsigned HOST_WIDE_INT array_size_for_constructor (tree);
162 static unsigned min_align (unsigned, unsigned);
163 static void output_constructor (tree, unsigned HOST_WIDE_INT, unsigned int);
164 static void globalize_decl (tree);
165 static void maybe_assemble_visibility (tree);
166 static int in_named_entry_eq (const void *, const void *);
167 static hashval_t in_named_entry_hash (const void *);
168 #ifdef ASM_OUTPUT_BSS
169 static void asm_output_bss (FILE *, tree, const char *,
170 unsigned HOST_WIDE_INT, unsigned HOST_WIDE_INT);
171 #endif
172 #ifdef BSS_SECTION_ASM_OP
173 #ifdef ASM_OUTPUT_ALIGNED_BSS
174 static void asm_output_aligned_bss (FILE *, tree, const char *,
175 unsigned HOST_WIDE_INT, int)
176 ATTRIBUTE_UNUSED;
177 #endif
178 #endif /* BSS_SECTION_ASM_OP */
179 static bool asm_emit_uninitialised (tree, const char*,
180 unsigned HOST_WIDE_INT,
181 unsigned HOST_WIDE_INT);
182 static void mark_weak (tree);
184 enum in_section { no_section, in_text, in_data, in_named
185 #ifdef BSS_SECTION_ASM_OP
186 , in_bss
187 #endif
188 #ifdef CTORS_SECTION_ASM_OP
189 , in_ctors
190 #endif
191 #ifdef DTORS_SECTION_ASM_OP
192 , in_dtors
193 #endif
194 #ifdef READONLY_DATA_SECTION_ASM_OP
195 , in_readonly_data
196 #endif
197 #ifdef EXTRA_SECTIONS
198 , EXTRA_SECTIONS
199 #endif
201 static GTY(()) enum in_section in_section = no_section;
203 /* Return a nonzero value if DECL has a section attribute. */
204 #ifndef IN_NAMED_SECTION
205 #define IN_NAMED_SECTION(DECL) \
206 ((TREE_CODE (DECL) == FUNCTION_DECL || TREE_CODE (DECL) == VAR_DECL) \
207 && DECL_SECTION_NAME (DECL) != NULL_TREE)
208 #endif
210 /* Text of section name when in_section == in_named. */
211 static GTY(()) const char *in_named_name;
213 /* Hash table of flags that have been used for a particular named section. */
215 struct in_named_entry GTY(())
217 const char *name;
218 unsigned int flags;
219 bool declared;
222 static GTY((param_is (struct in_named_entry))) htab_t in_named_htab;
224 /* Define functions like text_section for any extra sections. */
225 #ifdef EXTRA_SECTION_FUNCTIONS
226 EXTRA_SECTION_FUNCTIONS
227 #endif
229 /* Tell assembler to switch to text section. */
231 void
232 text_section (void)
234 if (in_section != in_text)
236 in_section = in_text;
237 fprintf (asm_out_file, "%s\n", TEXT_SECTION_ASM_OP);
241 /* Tell assembler to switch to data section. */
243 void
244 data_section (void)
246 if (in_section != in_data)
248 in_section = in_data;
249 if (flag_shared_data)
251 #ifdef SHARED_SECTION_ASM_OP
252 fprintf (asm_out_file, "%s\n", SHARED_SECTION_ASM_OP);
253 #else
254 fprintf (asm_out_file, "%s\n", DATA_SECTION_ASM_OP);
255 #endif
257 else
258 fprintf (asm_out_file, "%s\n", DATA_SECTION_ASM_OP);
262 /* Tell assembler to switch to read-only data section. This is normally
263 the text section. */
265 void
266 readonly_data_section (void)
268 #ifdef READONLY_DATA_SECTION
269 READONLY_DATA_SECTION (); /* Note this can call data_section. */
270 #else
271 #ifdef READONLY_DATA_SECTION_ASM_OP
272 if (in_section != in_readonly_data)
274 in_section = in_readonly_data;
275 fputs (READONLY_DATA_SECTION_ASM_OP, asm_out_file);
276 fputc ('\n', asm_out_file);
278 #else
279 text_section ();
280 #endif
281 #endif
284 /* Determine if we're in the text section. */
287 in_text_section (void)
289 return in_section == in_text;
292 /* Determine if we're in the data section. */
295 in_data_section (void)
297 return in_section == in_data;
300 /* Helper routines for maintaining in_named_htab. */
302 static int
303 in_named_entry_eq (const void *p1, const void *p2)
305 const struct in_named_entry *old = p1;
306 const char *new = p2;
308 return strcmp (old->name, new) == 0;
311 static hashval_t
312 in_named_entry_hash (const void *p)
314 const struct in_named_entry *old = p;
315 return htab_hash_string (old->name);
318 /* If SECTION has been seen before as a named section, return the flags
319 that were used. Otherwise, return 0. Note, that 0 is a perfectly valid
320 set of flags for a section to have, so 0 does not mean that the section
321 has not been seen. */
323 unsigned int
324 get_named_section_flags (const char *section)
326 struct in_named_entry **slot;
328 slot = (struct in_named_entry **)
329 htab_find_slot_with_hash (in_named_htab, section,
330 htab_hash_string (section), NO_INSERT);
332 return slot ? (*slot)->flags : 0;
335 /* Returns true if the section has been declared before. Sets internal
336 flag on this section in in_named_hash so subsequent calls on this
337 section will return false. */
339 bool
340 named_section_first_declaration (const char *name)
342 struct in_named_entry **slot;
344 slot = (struct in_named_entry **)
345 htab_find_slot_with_hash (in_named_htab, name,
346 htab_hash_string (name), NO_INSERT);
347 if (! (*slot)->declared)
349 (*slot)->declared = true;
350 return true;
352 else
354 return false;
359 /* Record FLAGS for SECTION. If SECTION was previously recorded with a
360 different set of flags, return false. */
362 bool
363 set_named_section_flags (const char *section, unsigned int flags)
365 struct in_named_entry **slot, *entry;
367 slot = (struct in_named_entry **)
368 htab_find_slot_with_hash (in_named_htab, section,
369 htab_hash_string (section), INSERT);
370 entry = *slot;
372 if (!entry)
374 entry = ggc_alloc (sizeof (*entry));
375 *slot = entry;
376 entry->name = ggc_strdup (section);
377 entry->flags = flags;
378 entry->declared = false;
380 else if (entry->flags != flags)
381 return false;
383 return true;
386 /* Tell assembler to change to section NAME with attributes FLAGS. */
388 void
389 named_section_flags (const char *name, unsigned int flags)
391 if (in_section != in_named || strcmp (name, in_named_name) != 0)
393 if (! set_named_section_flags (name, flags))
394 abort ();
396 (*targetm.asm_out.named_section) (name, flags);
398 if (flags & SECTION_FORGET)
399 in_section = no_section;
400 else
402 in_named_name = ggc_strdup (name);
403 in_section = in_named;
408 /* Tell assembler to change to section NAME for DECL.
409 If DECL is NULL, just switch to section NAME.
410 If NAME is NULL, get the name from DECL.
411 If RELOC is 1, the initializer for DECL contains relocs. */
413 void
414 named_section (tree decl, const char *name, int reloc)
416 unsigned int flags;
418 if (decl != NULL_TREE && !DECL_P (decl))
419 abort ();
420 if (name == NULL)
421 name = TREE_STRING_POINTER (DECL_SECTION_NAME (decl));
423 flags = (* targetm.section_type_flags) (decl, name, reloc);
425 /* Sanity check user variables for flag changes. Non-user
426 section flag changes will abort in named_section_flags.
427 However, don't complain if SECTION_OVERRIDE is set.
428 We trust that the setter knows that it is safe to ignore
429 the default flags for this decl. */
430 if (decl && ! set_named_section_flags (name, flags))
432 flags = get_named_section_flags (name);
433 if ((flags & SECTION_OVERRIDE) == 0)
434 error ("%J%D causes a section type conflict", decl, decl);
437 named_section_flags (name, flags);
440 /* If required, set DECL_SECTION_NAME to a unique name. */
442 void
443 resolve_unique_section (tree decl, int reloc ATTRIBUTE_UNUSED,
444 int flag_function_or_data_sections)
446 if (DECL_SECTION_NAME (decl) == NULL_TREE
447 && targetm.have_named_sections
448 && (flag_function_or_data_sections
449 || DECL_ONE_ONLY (decl)))
450 (*targetm.asm_out.unique_section) (decl, reloc);
453 #ifdef BSS_SECTION_ASM_OP
455 /* Tell the assembler to switch to the bss section. */
457 void
458 bss_section (void)
460 if (in_section != in_bss)
462 fprintf (asm_out_file, "%s\n", BSS_SECTION_ASM_OP);
463 in_section = in_bss;
467 #ifdef ASM_OUTPUT_BSS
469 /* Utility function for ASM_OUTPUT_BSS for targets to use if
470 they don't support alignments in .bss.
471 ??? It is believed that this function will work in most cases so such
472 support is localized here. */
474 static void
475 asm_output_bss (FILE *file, tree decl ATTRIBUTE_UNUSED,
476 const char *name,
477 unsigned HOST_WIDE_INT size ATTRIBUTE_UNUSED,
478 unsigned HOST_WIDE_INT rounded)
480 (*targetm.asm_out.globalize_label) (file, name);
481 bss_section ();
482 #ifdef ASM_DECLARE_OBJECT_NAME
483 last_assemble_variable_decl = decl;
484 ASM_DECLARE_OBJECT_NAME (file, name, decl);
485 #else
486 /* Standard thing is just output label for the object. */
487 ASM_OUTPUT_LABEL (file, name);
488 #endif /* ASM_DECLARE_OBJECT_NAME */
489 ASM_OUTPUT_SKIP (file, rounded ? rounded : 1);
492 #endif
494 #ifdef ASM_OUTPUT_ALIGNED_BSS
496 /* Utility function for targets to use in implementing
497 ASM_OUTPUT_ALIGNED_BSS.
498 ??? It is believed that this function will work in most cases so such
499 support is localized here. */
501 static void
502 asm_output_aligned_bss (FILE *file, tree decl ATTRIBUTE_UNUSED,
503 const char *name, unsigned HOST_WIDE_INT size,
504 int align)
506 bss_section ();
507 ASM_OUTPUT_ALIGN (file, floor_log2 (align / BITS_PER_UNIT));
508 #ifdef ASM_DECLARE_OBJECT_NAME
509 last_assemble_variable_decl = decl;
510 ASM_DECLARE_OBJECT_NAME (file, name, decl);
511 #else
512 /* Standard thing is just output label for the object. */
513 ASM_OUTPUT_LABEL (file, name);
514 #endif /* ASM_DECLARE_OBJECT_NAME */
515 ASM_OUTPUT_SKIP (file, size ? size : 1);
518 #endif
520 #endif /* BSS_SECTION_ASM_OP */
522 /* Switch to the section for function DECL.
524 If DECL is NULL_TREE, switch to the text section.
525 ??? It's not clear that we will ever be passed NULL_TREE, but it's
526 safer to handle it. */
528 void
529 function_section (tree decl)
531 if (decl != NULL_TREE
532 && DECL_SECTION_NAME (decl) != NULL_TREE)
533 named_section (decl, (char *) 0, 0);
534 else
535 text_section ();
538 /* Switch to read-only data section associated with function DECL. */
540 void
541 default_function_rodata_section (tree decl)
543 if (decl != NULL_TREE && DECL_SECTION_NAME (decl))
545 const char *name = TREE_STRING_POINTER (DECL_SECTION_NAME (decl));
547 /* For .gnu.linkonce.t.foo we want to use .gnu.linkonce.r.foo. */
548 if (DECL_ONE_ONLY (decl) && strncmp (name, ".gnu.linkonce.t.", 16) == 0)
550 size_t len = strlen (name) + 1;
551 char *rname = alloca (len);
553 memcpy (rname, name, len);
554 rname[14] = 'r';
555 named_section_flags (rname, SECTION_LINKONCE);
556 return;
558 /* For .text.foo we want to use .rodata.foo. */
559 else if (flag_function_sections && flag_data_sections
560 && strncmp (name, ".text.", 6) == 0)
562 size_t len = strlen (name) + 1;
563 char *rname = alloca (len + 2);
565 memcpy (rname, ".rodata", 7);
566 memcpy (rname + 7, name + 5, len - 5);
567 named_section_flags (rname, 0);
568 return;
572 readonly_data_section ();
575 /* Switch to read-only data section associated with function DECL
576 for targets where that section should be always the single
577 readonly data section. */
579 void
580 default_no_function_rodata_section (tree decl ATTRIBUTE_UNUSED)
582 readonly_data_section ();
585 /* Switch to section for variable DECL. RELOC is the same as the
586 argument to SELECT_SECTION. */
588 void
589 variable_section (tree decl, int reloc)
591 if (IN_NAMED_SECTION (decl))
592 named_section (decl, NULL, reloc);
593 else
594 (*targetm.asm_out.select_section) (decl, reloc, DECL_ALIGN (decl));
597 /* Tell assembler to switch to the section for string merging. */
599 void
600 mergeable_string_section (tree decl ATTRIBUTE_UNUSED,
601 unsigned HOST_WIDE_INT align ATTRIBUTE_UNUSED,
602 unsigned int flags ATTRIBUTE_UNUSED)
604 if (HAVE_GAS_SHF_MERGE && flag_merge_constants
605 && TREE_CODE (decl) == STRING_CST
606 && TREE_CODE (TREE_TYPE (decl)) == ARRAY_TYPE
607 && align <= 256
608 && TREE_STRING_LENGTH (decl) >= int_size_in_bytes (TREE_TYPE (decl)))
610 enum machine_mode mode;
611 unsigned int modesize;
612 const char *str;
613 int i, j, len, unit;
614 char name[30];
616 mode = TYPE_MODE (TREE_TYPE (TREE_TYPE (decl)));
617 modesize = GET_MODE_BITSIZE (mode);
618 if (modesize >= 8 && modesize <= 256
619 && (modesize & (modesize - 1)) == 0)
621 if (align < modesize)
622 align = modesize;
624 str = TREE_STRING_POINTER (decl);
625 len = TREE_STRING_LENGTH (decl);
626 unit = GET_MODE_SIZE (mode);
628 /* Check for embedded NUL characters. */
629 for (i = 0; i < len; i += unit)
631 for (j = 0; j < unit; j++)
632 if (str[i + j] != '\0')
633 break;
634 if (j == unit)
635 break;
637 if (i == len - unit)
639 sprintf (name, ".rodata.str%d.%d", modesize / 8,
640 (int) (align / 8));
641 flags |= (modesize / 8) | SECTION_MERGE | SECTION_STRINGS;
642 if (!i && modesize < align)
644 /* A "" string with requested alignment greater than
645 character size might cause a problem:
646 if some other string required even bigger
647 alignment than "", then linker might think the
648 "" is just part of padding after some other string
649 and not put it into the hash table initially.
650 But this means "" could have smaller alignment
651 than requested. */
652 #ifdef ASM_OUTPUT_SECTION_START
653 named_section_flags (name, flags);
654 ASM_OUTPUT_SECTION_START (asm_out_file);
655 #else
656 readonly_data_section ();
657 #endif
658 return;
661 named_section_flags (name, flags);
662 return;
667 readonly_data_section ();
670 /* Tell assembler to switch to the section for constant merging. */
672 void
673 mergeable_constant_section (enum machine_mode mode ATTRIBUTE_UNUSED,
674 unsigned HOST_WIDE_INT align ATTRIBUTE_UNUSED,
675 unsigned int flags ATTRIBUTE_UNUSED)
677 unsigned int modesize = GET_MODE_BITSIZE (mode);
679 if (HAVE_GAS_SHF_MERGE && flag_merge_constants
680 && mode != VOIDmode
681 && mode != BLKmode
682 && modesize <= align
683 && align >= 8
684 && align <= 256
685 && (align & (align - 1)) == 0)
687 char name[24];
689 sprintf (name, ".rodata.cst%d", (int) (align / 8));
690 flags |= (align / 8) | SECTION_MERGE;
691 named_section_flags (name, flags);
692 return;
695 readonly_data_section ();
698 /* Given NAME, a putative register name, discard any customary prefixes. */
700 static const char *
701 strip_reg_name (const char *name)
703 #ifdef REGISTER_PREFIX
704 if (!strncmp (name, REGISTER_PREFIX, strlen (REGISTER_PREFIX)))
705 name += strlen (REGISTER_PREFIX);
706 #endif
707 if (name[0] == '%' || name[0] == '#')
708 name++;
709 return name;
712 /* Decode an `asm' spec for a declaration as a register name.
713 Return the register number, or -1 if nothing specified,
714 or -2 if the ASMSPEC is not `cc' or `memory' and is not recognized,
715 or -3 if ASMSPEC is `cc' and is not recognized,
716 or -4 if ASMSPEC is `memory' and is not recognized.
717 Accept an exact spelling or a decimal number.
718 Prefixes such as % are optional. */
721 decode_reg_name (const char *asmspec)
723 if (asmspec != 0)
725 int i;
727 /* Get rid of confusing prefixes. */
728 asmspec = strip_reg_name (asmspec);
730 /* Allow a decimal number as a "register name". */
731 for (i = strlen (asmspec) - 1; i >= 0; i--)
732 if (! ISDIGIT (asmspec[i]))
733 break;
734 if (asmspec[0] != 0 && i < 0)
736 i = atoi (asmspec);
737 if (i < FIRST_PSEUDO_REGISTER && i >= 0)
738 return i;
739 else
740 return -2;
743 for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
744 if (reg_names[i][0]
745 && ! strcmp (asmspec, strip_reg_name (reg_names[i])))
746 return i;
748 #ifdef ADDITIONAL_REGISTER_NAMES
750 static const struct { const char *const name; const int number; } table[]
751 = ADDITIONAL_REGISTER_NAMES;
753 for (i = 0; i < (int) ARRAY_SIZE (table); i++)
754 if (! strcmp (asmspec, table[i].name))
755 return table[i].number;
757 #endif /* ADDITIONAL_REGISTER_NAMES */
759 if (!strcmp (asmspec, "memory"))
760 return -4;
762 if (!strcmp (asmspec, "cc"))
763 return -3;
765 return -2;
768 return -1;
771 /* Create the DECL_RTL for a VAR_DECL or FUNCTION_DECL. DECL should
772 have static storage duration. In other words, it should not be an
773 automatic variable, including PARM_DECLs.
775 There is, however, one exception: this function handles variables
776 explicitly placed in a particular register by the user.
778 ASMSPEC, if not 0, is the string which the user specified as the
779 assembler symbol name.
781 This is never called for PARM_DECL nodes. */
783 void
784 make_decl_rtl (tree decl, const char *asmspec)
786 const char *name = 0;
787 int reg_number;
788 rtx x;
790 /* Check that we are not being given an automatic variable. */
791 /* A weak alias has TREE_PUBLIC set but not the other bits. */
792 if (TREE_CODE (decl) == PARM_DECL
793 || TREE_CODE (decl) == RESULT_DECL
794 || (TREE_CODE (decl) == VAR_DECL
795 && !TREE_STATIC (decl)
796 && !TREE_PUBLIC (decl)
797 && !DECL_EXTERNAL (decl)
798 && !DECL_REGISTER (decl)))
799 abort ();
800 /* And that we were not given a type or a label. */
801 else if (TREE_CODE (decl) == TYPE_DECL
802 || TREE_CODE (decl) == LABEL_DECL)
803 abort ();
805 /* For a duplicate declaration, we can be called twice on the
806 same DECL node. Don't discard the RTL already made. */
807 if (DECL_RTL_SET_P (decl))
809 /* If the old RTL had the wrong mode, fix the mode. */
810 if (GET_MODE (DECL_RTL (decl)) != DECL_MODE (decl))
811 SET_DECL_RTL (decl, adjust_address_nv (DECL_RTL (decl),
812 DECL_MODE (decl), 0));
814 /* ??? Another way to do this would be to maintain a hashed
815 table of such critters. Instead of adding stuff to a DECL
816 to give certain attributes to it, we could use an external
817 hash map from DECL to set of attributes. */
819 /* Let the target reassign the RTL if it wants.
820 This is necessary, for example, when one machine specific
821 decl attribute overrides another. */
822 (* targetm.encode_section_info) (decl, DECL_RTL (decl), false);
823 return;
826 reg_number = decode_reg_name (asmspec);
827 if (reg_number == -2)
829 /* ASMSPEC is given, and not the name of a register. Mark the
830 name with a star so assemble_name won't munge it. */
831 char *starred = alloca (strlen (asmspec) + 2);
832 starred[0] = '*';
833 strcpy (starred + 1, asmspec);
834 change_decl_assembler_name (decl, get_identifier (starred));
837 name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
839 if (TREE_CODE (decl) != FUNCTION_DECL && DECL_REGISTER (decl))
841 /* First detect errors in declaring global registers. */
842 if (reg_number == -1)
843 error ("%Jregister name not specified for '%D'", decl, decl);
844 else if (reg_number < 0)
845 error ("%Jinvalid register name for '%D'", decl, decl);
846 else if (TYPE_MODE (TREE_TYPE (decl)) == BLKmode)
847 error ("%Jdata type of '%D' isn't suitable for a register",
848 decl, decl);
849 else if (! HARD_REGNO_MODE_OK (reg_number, TYPE_MODE (TREE_TYPE (decl))))
850 error ("%Jregister specified for '%D' isn't suitable for data type",
851 decl, decl);
852 /* Now handle properly declared static register variables. */
853 else
855 int nregs;
857 if (DECL_INITIAL (decl) != 0 && TREE_STATIC (decl))
859 DECL_INITIAL (decl) = 0;
860 error ("global register variable has initial value");
862 if (TREE_THIS_VOLATILE (decl))
863 warning ("volatile register variables don't work as you might wish");
865 /* If the user specified one of the eliminables registers here,
866 e.g., FRAME_POINTER_REGNUM, we don't want to get this variable
867 confused with that register and be eliminated. This usage is
868 somewhat suspect... */
870 SET_DECL_RTL (decl, gen_rtx_raw_REG (DECL_MODE (decl), reg_number));
871 ORIGINAL_REGNO (DECL_RTL (decl)) = reg_number;
872 REG_USERVAR_P (DECL_RTL (decl)) = 1;
874 if (TREE_STATIC (decl))
876 /* Make this register global, so not usable for anything
877 else. */
878 #ifdef ASM_DECLARE_REGISTER_GLOBAL
879 ASM_DECLARE_REGISTER_GLOBAL (asm_out_file, decl, reg_number, name);
880 #endif
881 nregs = HARD_REGNO_NREGS (reg_number, DECL_MODE (decl));
882 while (nregs > 0)
883 globalize_reg (reg_number + --nregs);
886 /* As a register variable, it has no section. */
887 return;
891 /* Now handle ordinary static variables and functions (in memory).
892 Also handle vars declared register invalidly. */
894 if (reg_number >= 0 || reg_number == -3)
895 error ("%Jregister name given for non-register variable '%D'", decl, decl);
897 /* Specifying a section attribute on a variable forces it into a
898 non-.bss section, and thus it cannot be common. */
899 if (TREE_CODE (decl) == VAR_DECL
900 && DECL_SECTION_NAME (decl) != NULL_TREE
901 && DECL_INITIAL (decl) == NULL_TREE
902 && DECL_COMMON (decl))
903 DECL_COMMON (decl) = 0;
905 /* Variables can't be both common and weak. */
906 if (TREE_CODE (decl) == VAR_DECL && DECL_WEAK (decl))
907 DECL_COMMON (decl) = 0;
909 x = gen_rtx_SYMBOL_REF (Pmode, name);
910 SYMBOL_REF_WEAK (x) = DECL_WEAK (decl);
911 SYMBOL_REF_DECL (x) = decl;
913 x = gen_rtx_MEM (DECL_MODE (decl), x);
914 if (TREE_CODE (decl) != FUNCTION_DECL)
915 set_mem_attributes (x, decl, 1);
916 SET_DECL_RTL (decl, x);
918 /* Optionally set flags or add text to the name to record information
919 such as that it is a function name.
920 If the name is changed, the macro ASM_OUTPUT_LABELREF
921 will have to know how to strip this information. */
922 (* targetm.encode_section_info) (decl, DECL_RTL (decl), true);
925 /* Make the rtl for variable VAR be volatile.
926 Use this only for static variables. */
928 void
929 make_var_volatile (tree var)
931 if (GET_CODE (DECL_RTL (var)) != MEM)
932 abort ();
934 MEM_VOLATILE_P (DECL_RTL (var)) = 1;
937 /* Output a string of literal assembler code
938 for an `asm' keyword used between functions. */
940 void
941 assemble_asm (tree string)
943 app_enable ();
945 if (TREE_CODE (string) == ADDR_EXPR)
946 string = TREE_OPERAND (string, 0);
948 fprintf (asm_out_file, "\t%s\n", TREE_STRING_POINTER (string));
951 /* Record an element in the table of global destructors. SYMBOL is
952 a SYMBOL_REF of the function to be called; PRIORITY is a number
953 between 0 and MAX_INIT_PRIORITY. */
955 void
956 default_stabs_asm_out_destructor (rtx symbol, int priority ATTRIBUTE_UNUSED)
958 /* Tell GNU LD that this is part of the static destructor set.
959 This will work for any system that uses stabs, most usefully
960 aout systems. */
961 fprintf (asm_out_file, "%s\"___DTOR_LIST__\",22,0,0,", ASM_STABS_OP);
962 assemble_name (asm_out_file, XSTR (symbol, 0));
963 fputc ('\n', asm_out_file);
966 void
967 default_named_section_asm_out_destructor (rtx symbol, int priority)
969 const char *section = ".dtors";
970 char buf[16];
972 /* ??? This only works reliably with the GNU linker. */
973 if (priority != DEFAULT_INIT_PRIORITY)
975 sprintf (buf, ".dtors.%.5u",
976 /* Invert the numbering so the linker puts us in the proper
977 order; constructors are run from right to left, and the
978 linker sorts in increasing order. */
979 MAX_INIT_PRIORITY - priority);
980 section = buf;
983 named_section_flags (section, SECTION_WRITE);
984 assemble_align (POINTER_SIZE);
985 assemble_integer (symbol, POINTER_SIZE / BITS_PER_UNIT, POINTER_SIZE, 1);
988 #ifdef DTORS_SECTION_ASM_OP
989 void
990 dtors_section (void)
992 if (in_section != in_dtors)
994 in_section = in_dtors;
995 fputs (DTORS_SECTION_ASM_OP, asm_out_file);
996 fputc ('\n', asm_out_file);
1000 void
1001 default_dtor_section_asm_out_destructor (rtx symbol,
1002 int priority ATTRIBUTE_UNUSED)
1004 dtors_section ();
1005 assemble_align (POINTER_SIZE);
1006 assemble_integer (symbol, POINTER_SIZE / BITS_PER_UNIT, POINTER_SIZE, 1);
1008 #endif
1010 /* Likewise for global constructors. */
1012 void
1013 default_stabs_asm_out_constructor (rtx symbol, int priority ATTRIBUTE_UNUSED)
1015 /* Tell GNU LD that this is part of the static destructor set.
1016 This will work for any system that uses stabs, most usefully
1017 aout systems. */
1018 fprintf (asm_out_file, "%s\"___CTOR_LIST__\",22,0,0,", ASM_STABS_OP);
1019 assemble_name (asm_out_file, XSTR (symbol, 0));
1020 fputc ('\n', asm_out_file);
1023 void
1024 default_named_section_asm_out_constructor (rtx symbol, int priority)
1026 const char *section = ".ctors";
1027 char buf[16];
1029 /* ??? This only works reliably with the GNU linker. */
1030 if (priority != DEFAULT_INIT_PRIORITY)
1032 sprintf (buf, ".ctors.%.5u",
1033 /* Invert the numbering so the linker puts us in the proper
1034 order; constructors are run from right to left, and the
1035 linker sorts in increasing order. */
1036 MAX_INIT_PRIORITY - priority);
1037 section = buf;
1040 named_section_flags (section, SECTION_WRITE);
1041 assemble_align (POINTER_SIZE);
1042 assemble_integer (symbol, POINTER_SIZE / BITS_PER_UNIT, POINTER_SIZE, 1);
1045 #ifdef CTORS_SECTION_ASM_OP
1046 void
1047 ctors_section (void)
1049 if (in_section != in_ctors)
1051 in_section = in_ctors;
1052 fputs (CTORS_SECTION_ASM_OP, asm_out_file);
1053 fputc ('\n', asm_out_file);
1057 void
1058 default_ctor_section_asm_out_constructor (rtx symbol,
1059 int priority ATTRIBUTE_UNUSED)
1061 ctors_section ();
1062 assemble_align (POINTER_SIZE);
1063 assemble_integer (symbol, POINTER_SIZE / BITS_PER_UNIT, POINTER_SIZE, 1);
1065 #endif
1067 /* CONSTANT_POOL_BEFORE_FUNCTION may be defined as an expression with
1068 a nonzero value if the constant pool should be output before the
1069 start of the function, or a zero value if the pool should output
1070 after the end of the function. The default is to put it before the
1071 start. */
1073 #ifndef CONSTANT_POOL_BEFORE_FUNCTION
1074 #define CONSTANT_POOL_BEFORE_FUNCTION 1
1075 #endif
1077 /* DECL is an object (either VAR_DECL or FUNCTION_DECL) which is going
1078 to be output to assembler.
1079 Set first_global_object_name and weak_global_object_name as appropriate. */
1081 void
1082 notice_global_symbol (tree decl)
1084 const char **type = &first_global_object_name;
1086 if (first_global_object_name
1087 || !TREE_PUBLIC (decl) || DECL_EXTERNAL (decl)
1088 || !DECL_NAME (decl)
1089 || (TREE_CODE (decl) != FUNCTION_DECL
1090 && (TREE_CODE (decl) != VAR_DECL
1091 || (DECL_COMMON (decl)
1092 && (DECL_INITIAL (decl) == 0
1093 || DECL_INITIAL (decl) == error_mark_node))))
1094 || GET_CODE (DECL_RTL (decl)) != MEM)
1095 return;
1097 /* We win when global object is found, but it is usefull to know about weak
1098 symbol as well so we can produce nicer unique names. */
1099 if (DECL_WEAK (decl) || DECL_ONE_ONLY (decl))
1100 type = &weak_global_object_name;
1102 if (!*type)
1104 const char *p;
1105 char *name;
1106 rtx decl_rtl = DECL_RTL (decl);
1108 p = (* targetm.strip_name_encoding) (XSTR (XEXP (decl_rtl, 0), 0));
1109 name = xstrdup (p);
1111 *type = name;
1115 /* Output assembler code for the constant pool of a function and associated
1116 with defining the name of the function. DECL describes the function.
1117 NAME is the function's name. For the constant pool, we use the current
1118 constant pool data. */
1120 void
1121 assemble_start_function (tree decl, const char *fnname)
1123 int align;
1125 /* The following code does not need preprocessing in the assembler. */
1127 app_disable ();
1129 if (CONSTANT_POOL_BEFORE_FUNCTION)
1130 output_constant_pool (fnname, decl);
1132 resolve_unique_section (decl, 0, flag_function_sections);
1133 function_section (decl);
1135 /* Tell assembler to move to target machine's alignment for functions. */
1136 align = floor_log2 (FUNCTION_BOUNDARY / BITS_PER_UNIT);
1137 if (align < force_align_functions_log)
1138 align = force_align_functions_log;
1139 if (align > 0)
1141 ASM_OUTPUT_ALIGN (asm_out_file, align);
1144 /* Handle a user-specified function alignment.
1145 Note that we still need to align to FUNCTION_BOUNDARY, as above,
1146 because ASM_OUTPUT_MAX_SKIP_ALIGN might not do any alignment at all. */
1147 if (align_functions_log > align
1148 && cfun->function_frequency != FUNCTION_FREQUENCY_UNLIKELY_EXECUTED)
1150 #ifdef ASM_OUTPUT_MAX_SKIP_ALIGN
1151 ASM_OUTPUT_MAX_SKIP_ALIGN (asm_out_file,
1152 align_functions_log, align_functions - 1);
1153 #else
1154 ASM_OUTPUT_ALIGN (asm_out_file, align_functions_log);
1155 #endif
1158 #ifdef ASM_OUTPUT_FUNCTION_PREFIX
1159 ASM_OUTPUT_FUNCTION_PREFIX (asm_out_file, fnname);
1160 #endif
1162 (*debug_hooks->begin_function) (decl);
1164 /* Make function name accessible from other files, if appropriate. */
1166 if (TREE_PUBLIC (decl))
1168 notice_global_symbol (decl);
1170 globalize_decl (decl);
1172 maybe_assemble_visibility (decl);
1175 /* Do any machine/system dependent processing of the function name. */
1176 #ifdef ASM_DECLARE_FUNCTION_NAME
1177 ASM_DECLARE_FUNCTION_NAME (asm_out_file, fnname, current_function_decl);
1178 #else
1179 /* Standard thing is just output label for the function. */
1180 ASM_OUTPUT_LABEL (asm_out_file, fnname);
1181 #endif /* ASM_DECLARE_FUNCTION_NAME */
1184 /* Output assembler code associated with defining the size of the
1185 function. DECL describes the function. NAME is the function's name. */
1187 void
1188 assemble_end_function (tree decl, const char *fnname)
1190 #ifdef ASM_DECLARE_FUNCTION_SIZE
1191 ASM_DECLARE_FUNCTION_SIZE (asm_out_file, fnname, decl);
1192 #endif
1193 if (! CONSTANT_POOL_BEFORE_FUNCTION)
1195 output_constant_pool (fnname, decl);
1196 function_section (decl); /* need to switch back */
1200 /* Assemble code to leave SIZE bytes of zeros. */
1202 void
1203 assemble_zeros (unsigned HOST_WIDE_INT size)
1205 /* Do no output if -fsyntax-only. */
1206 if (flag_syntax_only)
1207 return;
1209 #ifdef ASM_NO_SKIP_IN_TEXT
1210 /* The `space' pseudo in the text section outputs nop insns rather than 0s,
1211 so we must output 0s explicitly in the text section. */
1212 if (ASM_NO_SKIP_IN_TEXT && in_text_section ())
1214 unsigned HOST_WIDE_INT i;
1215 for (i = 0; i < size; i++)
1216 assemble_integer (const0_rtx, 1, BITS_PER_UNIT, 1);
1218 else
1219 #endif
1220 if (size > 0)
1221 ASM_OUTPUT_SKIP (asm_out_file, size);
1224 /* Assemble an alignment pseudo op for an ALIGN-bit boundary. */
1226 void
1227 assemble_align (int align)
1229 if (align > BITS_PER_UNIT)
1231 ASM_OUTPUT_ALIGN (asm_out_file, floor_log2 (align / BITS_PER_UNIT));
1235 /* Assemble a string constant with the specified C string as contents. */
1237 void
1238 assemble_string (const char *p, int size)
1240 int pos = 0;
1241 int maximum = 2000;
1243 /* If the string is very long, split it up. */
1245 while (pos < size)
1247 int thissize = size - pos;
1248 if (thissize > maximum)
1249 thissize = maximum;
1251 ASM_OUTPUT_ASCII (asm_out_file, p, thissize);
1253 pos += thissize;
1254 p += thissize;
1259 #if defined ASM_OUTPUT_ALIGNED_DECL_LOCAL
1260 #define ASM_EMIT_LOCAL(decl, name, size, rounded) \
1261 ASM_OUTPUT_ALIGNED_DECL_LOCAL (asm_out_file, decl, name, size, DECL_ALIGN (decl))
1262 #else
1263 #if defined ASM_OUTPUT_ALIGNED_LOCAL
1264 #define ASM_EMIT_LOCAL(decl, name, size, rounded) \
1265 ASM_OUTPUT_ALIGNED_LOCAL (asm_out_file, name, size, DECL_ALIGN (decl))
1266 #else
1267 #define ASM_EMIT_LOCAL(decl, name, size, rounded) \
1268 ASM_OUTPUT_LOCAL (asm_out_file, name, size, rounded)
1269 #endif
1270 #endif
1272 #if defined ASM_OUTPUT_ALIGNED_BSS
1273 #define ASM_EMIT_BSS(decl, name, size, rounded) \
1274 ASM_OUTPUT_ALIGNED_BSS (asm_out_file, decl, name, size, DECL_ALIGN (decl))
1275 #else
1276 #if defined ASM_OUTPUT_BSS
1277 #define ASM_EMIT_BSS(decl, name, size, rounded) \
1278 ASM_OUTPUT_BSS (asm_out_file, decl, name, size, rounded)
1279 #else
1280 #undef ASM_EMIT_BSS
1281 #endif
1282 #endif
1284 #if defined ASM_OUTPUT_ALIGNED_DECL_COMMON
1285 #define ASM_EMIT_COMMON(decl, name, size, rounded) \
1286 ASM_OUTPUT_ALIGNED_DECL_COMMON (asm_out_file, decl, name, size, DECL_ALIGN (decl))
1287 #else
1288 #if defined ASM_OUTPUT_ALIGNED_COMMON
1289 #define ASM_EMIT_COMMON(decl, name, size, rounded) \
1290 ASM_OUTPUT_ALIGNED_COMMON (asm_out_file, name, size, DECL_ALIGN (decl))
1291 #else
1292 #define ASM_EMIT_COMMON(decl, name, size, rounded) \
1293 ASM_OUTPUT_COMMON (asm_out_file, name, size, rounded)
1294 #endif
1295 #endif
1297 static bool
1298 asm_emit_uninitialised (tree decl, const char *name,
1299 unsigned HOST_WIDE_INT size ATTRIBUTE_UNUSED,
1300 unsigned HOST_WIDE_INT rounded ATTRIBUTE_UNUSED)
1302 enum
1304 asm_dest_common,
1305 asm_dest_bss,
1306 asm_dest_local
1308 destination = asm_dest_local;
1310 /* ??? We should handle .bss via select_section mechanisms rather than
1311 via special target hooks. That would eliminate this special case. */
1312 if (TREE_PUBLIC (decl))
1314 if (!DECL_COMMON (decl))
1315 #ifdef ASM_EMIT_BSS
1316 destination = asm_dest_bss;
1317 #else
1318 return false;
1319 #endif
1320 else
1321 destination = asm_dest_common;
1324 if (destination == asm_dest_bss)
1325 globalize_decl (decl);
1326 resolve_unique_section (decl, 0, flag_data_sections);
1328 if (flag_shared_data)
1330 switch (destination)
1332 #ifdef ASM_OUTPUT_SHARED_BSS
1333 case asm_dest_bss:
1334 ASM_OUTPUT_SHARED_BSS (asm_out_file, decl, name, size, rounded);
1335 return;
1336 #endif
1337 #ifdef ASM_OUTPUT_SHARED_COMMON
1338 case asm_dest_common:
1339 ASM_OUTPUT_SHARED_COMMON (asm_out_file, name, size, rounded);
1340 return;
1341 #endif
1342 #ifdef ASM_OUTPUT_SHARED_LOCAL
1343 case asm_dest_local:
1344 ASM_OUTPUT_SHARED_LOCAL (asm_out_file, name, size, rounded);
1345 return;
1346 #endif
1347 default:
1348 break;
1352 switch (destination)
1354 #ifdef ASM_EMIT_BSS
1355 case asm_dest_bss:
1356 ASM_EMIT_BSS (decl, name, size, rounded);
1357 break;
1358 #endif
1359 case asm_dest_common:
1360 ASM_EMIT_COMMON (decl, name, size, rounded);
1361 break;
1362 case asm_dest_local:
1363 ASM_EMIT_LOCAL (decl, name, size, rounded);
1364 break;
1365 default:
1366 abort ();
1369 return true;
1372 /* Assemble everything that is needed for a variable or function declaration.
1373 Not used for automatic variables, and not used for function definitions.
1374 Should not be called for variables of incomplete structure type.
1376 TOP_LEVEL is nonzero if this variable has file scope.
1377 AT_END is nonzero if this is the special handling, at end of compilation,
1378 to define things that have had only tentative definitions.
1379 DONT_OUTPUT_DATA if nonzero means don't actually output the
1380 initial value (that will be done by the caller). */
1382 void
1383 assemble_variable (tree decl, int top_level ATTRIBUTE_UNUSED,
1384 int at_end ATTRIBUTE_UNUSED, int dont_output_data)
1386 const char *name;
1387 unsigned int align;
1388 int reloc = 0;
1389 rtx decl_rtl;
1391 if (lang_hooks.decls.prepare_assemble_variable)
1392 (*lang_hooks.decls.prepare_assemble_variable) (decl);
1394 last_assemble_variable_decl = 0;
1396 /* Normally no need to say anything here for external references,
1397 since assemble_external is called by the language-specific code
1398 when a declaration is first seen. */
1400 if (DECL_EXTERNAL (decl))
1401 return;
1403 /* Output no assembler code for a function declaration.
1404 Only definitions of functions output anything. */
1406 if (TREE_CODE (decl) == FUNCTION_DECL)
1407 return;
1409 /* Do nothing for global register variables. */
1410 if (DECL_RTL_SET_P (decl) && GET_CODE (DECL_RTL (decl)) == REG)
1412 TREE_ASM_WRITTEN (decl) = 1;
1413 return;
1416 /* If type was incomplete when the variable was declared,
1417 see if it is complete now. */
1419 if (DECL_SIZE (decl) == 0)
1420 layout_decl (decl, 0);
1422 /* Still incomplete => don't allocate it; treat the tentative defn
1423 (which is what it must have been) as an `extern' reference. */
1425 if (!dont_output_data && DECL_SIZE (decl) == 0)
1427 error ("%Jstorage size of `%D' isn't known", decl, decl);
1428 TREE_ASM_WRITTEN (decl) = 1;
1429 return;
1432 /* The first declaration of a variable that comes through this function
1433 decides whether it is global (in C, has external linkage)
1434 or local (in C, has internal linkage). So do nothing more
1435 if this function has already run. */
1437 if (TREE_ASM_WRITTEN (decl))
1438 return;
1440 /* Make sure targetm.encode_section_info is invoked before we set
1441 ASM_WRITTEN. */
1442 decl_rtl = DECL_RTL (decl);
1444 TREE_ASM_WRITTEN (decl) = 1;
1446 /* Do no output if -fsyntax-only. */
1447 if (flag_syntax_only)
1448 return;
1450 app_disable ();
1452 if (! dont_output_data
1453 && ! host_integerp (DECL_SIZE_UNIT (decl), 1))
1455 error ("%Jsize of variable '%D' is too large", decl, decl);
1456 return;
1459 name = XSTR (XEXP (decl_rtl, 0), 0);
1460 if (TREE_PUBLIC (decl) && DECL_NAME (decl))
1461 notice_global_symbol (decl);
1463 /* Compute the alignment of this data. */
1465 align = DECL_ALIGN (decl);
1467 /* In the case for initialing an array whose length isn't specified,
1468 where we have not yet been able to do the layout,
1469 figure out the proper alignment now. */
1470 if (dont_output_data && DECL_SIZE (decl) == 0
1471 && TREE_CODE (TREE_TYPE (decl)) == ARRAY_TYPE)
1472 align = MAX (align, TYPE_ALIGN (TREE_TYPE (TREE_TYPE (decl))));
1474 /* Some object file formats have a maximum alignment which they support.
1475 In particular, a.out format supports a maximum alignment of 4. */
1476 #ifndef MAX_OFILE_ALIGNMENT
1477 #define MAX_OFILE_ALIGNMENT BIGGEST_ALIGNMENT
1478 #endif
1479 if (align > MAX_OFILE_ALIGNMENT)
1481 warning ("%Jalignment of '%D' is greater than maximum object "
1482 "file alignment. Using %d", decl, decl,
1483 MAX_OFILE_ALIGNMENT/BITS_PER_UNIT);
1484 align = MAX_OFILE_ALIGNMENT;
1487 /* On some machines, it is good to increase alignment sometimes. */
1488 if (! DECL_USER_ALIGN (decl))
1490 #ifdef DATA_ALIGNMENT
1491 align = DATA_ALIGNMENT (TREE_TYPE (decl), align);
1492 #endif
1493 #ifdef CONSTANT_ALIGNMENT
1494 if (DECL_INITIAL (decl) != 0 && DECL_INITIAL (decl) != error_mark_node)
1495 align = CONSTANT_ALIGNMENT (DECL_INITIAL (decl), align);
1496 #endif
1499 /* Reset the alignment in case we have made it tighter, so we can benefit
1500 from it in get_pointer_alignment. */
1501 DECL_ALIGN (decl) = align;
1502 set_mem_align (decl_rtl, align);
1504 if (TREE_PUBLIC (decl))
1505 maybe_assemble_visibility (decl);
1507 /* Output any data that we will need to use the address of. */
1508 if (DECL_INITIAL (decl) == error_mark_node)
1509 reloc = contains_pointers_p (TREE_TYPE (decl)) ? 3 : 0;
1510 else if (DECL_INITIAL (decl))
1512 reloc = compute_reloc_for_constant (DECL_INITIAL (decl));
1513 output_addressed_constants (DECL_INITIAL (decl));
1515 resolve_unique_section (decl, reloc, flag_data_sections);
1517 /* Handle uninitialized definitions. */
1519 /* If the decl has been given an explicit section name, then it
1520 isn't common, and shouldn't be handled as such. */
1521 if (DECL_SECTION_NAME (decl) || dont_output_data)
1523 /* We don't implement common thread-local data at present. */
1524 else if (DECL_THREAD_LOCAL (decl))
1526 if (DECL_COMMON (decl))
1527 sorry ("thread-local COMMON data not implemented");
1529 else if (DECL_INITIAL (decl) == 0
1530 || DECL_INITIAL (decl) == error_mark_node
1531 || (flag_zero_initialized_in_bss
1532 /* Leave constant zeroes in .rodata so they can be shared. */
1533 && !TREE_READONLY (decl)
1534 && initializer_zerop (DECL_INITIAL (decl))))
1536 unsigned HOST_WIDE_INT size = tree_low_cst (DECL_SIZE_UNIT (decl), 1);
1537 unsigned HOST_WIDE_INT rounded = size;
1539 /* Don't allocate zero bytes of common,
1540 since that means "undefined external" in the linker. */
1541 if (size == 0)
1542 rounded = 1;
1544 /* Round size up to multiple of BIGGEST_ALIGNMENT bits
1545 so that each uninitialized object starts on such a boundary. */
1546 rounded += (BIGGEST_ALIGNMENT / BITS_PER_UNIT) - 1;
1547 rounded = (rounded / (BIGGEST_ALIGNMENT / BITS_PER_UNIT)
1548 * (BIGGEST_ALIGNMENT / BITS_PER_UNIT));
1550 #if !defined(ASM_OUTPUT_ALIGNED_COMMON) && !defined(ASM_OUTPUT_ALIGNED_DECL_COMMON) && !defined(ASM_OUTPUT_ALIGNED_BSS)
1551 if ((unsigned HOST_WIDE_INT) DECL_ALIGN (decl) / BITS_PER_UNIT > rounded)
1552 warning ("%Jrequested alignment for '%D' is greater than "
1553 "implemented alignment of %d", decl, decl, rounded);
1554 #endif
1556 /* If the target cannot output uninitialized but not common global data
1557 in .bss, then we have to use .data, so fall through. */
1558 if (asm_emit_uninitialised (decl, name, size, rounded))
1559 return;
1562 /* Handle initialized definitions.
1563 Also handle uninitialized global definitions if -fno-common and the
1564 target doesn't support ASM_OUTPUT_BSS. */
1566 /* First make the assembler name(s) global if appropriate. */
1567 if (TREE_PUBLIC (decl) && DECL_NAME (decl))
1568 globalize_decl (decl);
1570 /* Switch to the appropriate section. */
1571 variable_section (decl, reloc);
1573 /* dbxout.c needs to know this. */
1574 if (in_text_section ())
1575 DECL_IN_TEXT_SECTION (decl) = 1;
1577 /* Output the alignment of this data. */
1578 if (align > BITS_PER_UNIT)
1580 ASM_OUTPUT_ALIGN (asm_out_file,
1581 floor_log2 (DECL_ALIGN (decl) / BITS_PER_UNIT));
1584 /* Do any machine/system dependent processing of the object. */
1585 #ifdef ASM_DECLARE_OBJECT_NAME
1586 last_assemble_variable_decl = decl;
1587 ASM_DECLARE_OBJECT_NAME (asm_out_file, name, decl);
1588 #else
1589 /* Standard thing is just output label for the object. */
1590 ASM_OUTPUT_LABEL (asm_out_file, name);
1591 #endif /* ASM_DECLARE_OBJECT_NAME */
1593 if (!dont_output_data)
1595 if (DECL_INITIAL (decl) && DECL_INITIAL (decl) != error_mark_node)
1596 /* Output the actual data. */
1597 output_constant (DECL_INITIAL (decl),
1598 tree_low_cst (DECL_SIZE_UNIT (decl), 1),
1599 align);
1600 else
1601 /* Leave space for it. */
1602 assemble_zeros (tree_low_cst (DECL_SIZE_UNIT (decl), 1));
1606 /* Return 1 if type TYPE contains any pointers. */
1608 static int
1609 contains_pointers_p (tree type)
1611 switch (TREE_CODE (type))
1613 case POINTER_TYPE:
1614 case REFERENCE_TYPE:
1615 /* I'm not sure whether OFFSET_TYPE needs this treatment,
1616 so I'll play safe and return 1. */
1617 case OFFSET_TYPE:
1618 return 1;
1620 case RECORD_TYPE:
1621 case UNION_TYPE:
1622 case QUAL_UNION_TYPE:
1624 tree fields;
1625 /* For a type that has fields, see if the fields have pointers. */
1626 for (fields = TYPE_FIELDS (type); fields; fields = TREE_CHAIN (fields))
1627 if (TREE_CODE (fields) == FIELD_DECL
1628 && contains_pointers_p (TREE_TYPE (fields)))
1629 return 1;
1630 return 0;
1633 case ARRAY_TYPE:
1634 /* An array type contains pointers if its element type does. */
1635 return contains_pointers_p (TREE_TYPE (type));
1637 default:
1638 return 0;
1642 #ifdef ASM_OUTPUT_EXTERNAL
1643 /* True if DECL is a function decl for which no out-of-line copy exists.
1644 It is assumed that DECL's assembler name has been set. */
1646 static bool
1647 incorporeal_function_p (tree decl)
1649 if (TREE_CODE (decl) == FUNCTION_DECL && DECL_BUILT_IN (decl))
1651 const char *name;
1653 if (DECL_BUILT_IN_CLASS (decl) == BUILT_IN_NORMAL
1654 && DECL_FUNCTION_CODE (decl) == BUILT_IN_ALLOCA)
1655 return true;
1657 name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
1658 if (strncmp (name, "__builtin_", strlen ("__builtin_")) == 0)
1659 return true;
1661 return false;
1663 #endif
1665 /* Output something to declare an external symbol to the assembler.
1666 (Most assemblers don't need this, so we normally output nothing.)
1667 Do nothing if DECL is not external. */
1669 void
1670 assemble_external (tree decl ATTRIBUTE_UNUSED)
1672 /* Because most platforms do not define ASM_OUTPUT_EXTERNAL, the
1673 main body of this code is only rarely exercised. To provide some
1674 testing, on all platforms, we make sure that the ASM_OUT_FILE is
1675 open. If it's not, we should not be calling this function. */
1676 if (!asm_out_file)
1677 abort ();
1679 #ifdef ASM_OUTPUT_EXTERNAL
1680 if (DECL_P (decl) && DECL_EXTERNAL (decl) && TREE_PUBLIC (decl))
1682 rtx rtl = DECL_RTL (decl);
1684 if (GET_CODE (rtl) == MEM && GET_CODE (XEXP (rtl, 0)) == SYMBOL_REF
1685 && !SYMBOL_REF_USED (XEXP (rtl, 0))
1686 && !incorporeal_function_p (decl))
1688 /* Some systems do require some output. */
1689 SYMBOL_REF_USED (XEXP (rtl, 0)) = 1;
1690 ASM_OUTPUT_EXTERNAL (asm_out_file, decl, XSTR (XEXP (rtl, 0), 0));
1693 #endif
1696 /* Similar, for calling a library function FUN. */
1698 void
1699 assemble_external_libcall (rtx fun)
1701 /* Declare library function name external when first used, if nec. */
1702 if (! SYMBOL_REF_USED (fun))
1704 SYMBOL_REF_USED (fun) = 1;
1705 (*targetm.asm_out.external_libcall) (fun);
1709 /* Assemble a label named NAME. */
1711 void
1712 assemble_label (const char *name)
1714 ASM_OUTPUT_LABEL (asm_out_file, name);
1717 /* Set the symbol_referenced flag for ID and notify callgraph code. */
1718 void
1719 mark_referenced (tree id)
1721 if (!TREE_SYMBOL_REFERENCED (id))
1723 struct cgraph_node *node;
1724 struct cgraph_varpool_node *vnode;
1726 if (!cgraph_global_info_ready)
1728 node = cgraph_node_for_identifier (id);
1729 if (node)
1730 cgraph_mark_needed_node (node);
1733 vnode = cgraph_varpool_node_for_identifier (id);
1734 if (vnode)
1735 cgraph_varpool_mark_needed_node (vnode);
1737 TREE_SYMBOL_REFERENCED (id) = 1;
1740 /* Output to FILE a reference to the assembler name of a C-level name NAME.
1741 If NAME starts with a *, the rest of NAME is output verbatim.
1742 Otherwise NAME is transformed in an implementation-defined way
1743 (usually by the addition of an underscore).
1744 Many macros in the tm file are defined to call this function. */
1746 void
1747 assemble_name (FILE *file, const char *name)
1749 const char *real_name;
1750 tree id;
1752 real_name = (* targetm.strip_name_encoding) (name);
1754 id = maybe_get_identifier (real_name);
1755 if (id)
1756 mark_referenced (id);
1758 if (name[0] == '*')
1759 fputs (&name[1], file);
1760 else
1761 ASM_OUTPUT_LABELREF (file, name);
1764 /* Allocate SIZE bytes writable static space with a gensym name
1765 and return an RTX to refer to its address. */
1768 assemble_static_space (unsigned HOST_WIDE_INT size)
1770 char name[12];
1771 const char *namestring;
1772 rtx x;
1774 #if 0
1775 if (flag_shared_data)
1776 data_section ();
1777 #endif
1779 ASM_GENERATE_INTERNAL_LABEL (name, "LF", const_labelno);
1780 ++const_labelno;
1781 namestring = ggc_strdup (name);
1783 x = gen_rtx_SYMBOL_REF (Pmode, namestring);
1784 SYMBOL_REF_FLAGS (x) = SYMBOL_FLAG_LOCAL;
1786 #ifdef ASM_OUTPUT_ALIGNED_DECL_LOCAL
1787 ASM_OUTPUT_ALIGNED_DECL_LOCAL (asm_out_file, NULL_TREE, name, size,
1788 BIGGEST_ALIGNMENT);
1789 #else
1790 #ifdef ASM_OUTPUT_ALIGNED_LOCAL
1791 ASM_OUTPUT_ALIGNED_LOCAL (asm_out_file, name, size, BIGGEST_ALIGNMENT);
1792 #else
1794 /* Round size up to multiple of BIGGEST_ALIGNMENT bits
1795 so that each uninitialized object starts on such a boundary. */
1796 /* Variable `rounded' might or might not be used in ASM_OUTPUT_LOCAL. */
1797 unsigned HOST_WIDE_INT rounded ATTRIBUTE_UNUSED
1798 = ((size + (BIGGEST_ALIGNMENT / BITS_PER_UNIT) - 1)
1799 / (BIGGEST_ALIGNMENT / BITS_PER_UNIT)
1800 * (BIGGEST_ALIGNMENT / BITS_PER_UNIT));
1801 ASM_OUTPUT_LOCAL (asm_out_file, name, size, rounded);
1803 #endif
1804 #endif
1805 return x;
1808 /* Assemble the static constant template for function entry trampolines.
1809 This is done at most once per compilation.
1810 Returns an RTX for the address of the template. */
1812 #ifdef TRAMPOLINE_TEMPLATE
1814 assemble_trampoline_template (void)
1816 char label[256];
1817 const char *name;
1818 int align;
1819 rtx symbol;
1821 /* By default, put trampoline templates in read-only data section. */
1823 #ifdef TRAMPOLINE_SECTION
1824 TRAMPOLINE_SECTION ();
1825 #else
1826 readonly_data_section ();
1827 #endif
1829 /* Write the assembler code to define one. */
1830 align = floor_log2 (TRAMPOLINE_ALIGNMENT / BITS_PER_UNIT);
1831 if (align > 0)
1833 ASM_OUTPUT_ALIGN (asm_out_file, align);
1836 (*targetm.asm_out.internal_label) (asm_out_file, "LTRAMP", 0);
1837 TRAMPOLINE_TEMPLATE (asm_out_file);
1839 /* Record the rtl to refer to it. */
1840 ASM_GENERATE_INTERNAL_LABEL (label, "LTRAMP", 0);
1841 name = ggc_strdup (label);
1842 symbol = gen_rtx_SYMBOL_REF (Pmode, name);
1843 SYMBOL_REF_FLAGS (symbol) = SYMBOL_FLAG_LOCAL;
1845 return symbol;
1847 #endif
1849 /* A and B are either alignments or offsets. Return the minimum alignment
1850 that may be assumed after adding the two together. */
1852 static inline unsigned
1853 min_align (unsigned int a, unsigned int b)
1855 return (a | b) & -(a | b);
1858 /* Return the assembler directive for creating a given kind of integer
1859 object. SIZE is the number of bytes in the object and ALIGNED_P
1860 indicates whether it is known to be aligned. Return NULL if the
1861 assembly dialect has no such directive.
1863 The returned string should be printed at the start of a new line and
1864 be followed immediately by the object's initial value. */
1866 const char *
1867 integer_asm_op (int size, int aligned_p)
1869 struct asm_int_op *ops;
1871 if (aligned_p)
1872 ops = &targetm.asm_out.aligned_op;
1873 else
1874 ops = &targetm.asm_out.unaligned_op;
1876 switch (size)
1878 case 1:
1879 return targetm.asm_out.byte_op;
1880 case 2:
1881 return ops->hi;
1882 case 4:
1883 return ops->si;
1884 case 8:
1885 return ops->di;
1886 case 16:
1887 return ops->ti;
1888 default:
1889 return NULL;
1893 /* Use directive OP to assemble an integer object X. Print OP at the
1894 start of the line, followed immediately by the value of X. */
1896 void
1897 assemble_integer_with_op (const char *op, rtx x)
1899 fputs (op, asm_out_file);
1900 output_addr_const (asm_out_file, x);
1901 fputc ('\n', asm_out_file);
1904 /* The default implementation of the asm_out.integer target hook. */
1906 bool
1907 default_assemble_integer (rtx x ATTRIBUTE_UNUSED,
1908 unsigned int size ATTRIBUTE_UNUSED,
1909 int aligned_p ATTRIBUTE_UNUSED)
1911 const char *op = integer_asm_op (size, aligned_p);
1912 return op && (assemble_integer_with_op (op, x), true);
1915 /* Assemble the integer constant X into an object of SIZE bytes. ALIGN is
1916 the alignment of the integer in bits. Return 1 if we were able to output
1917 the constant, otherwise 0. If FORCE is nonzero, abort if we can't output
1918 the constant. */
1920 bool
1921 assemble_integer (rtx x, unsigned int size, unsigned int align, int force)
1923 int aligned_p;
1925 aligned_p = (align >= MIN (size * BITS_PER_UNIT, BIGGEST_ALIGNMENT));
1927 /* See if the target hook can handle this kind of object. */
1928 if ((*targetm.asm_out.integer) (x, size, aligned_p))
1929 return true;
1931 /* If the object is a multi-byte one, try splitting it up. Split
1932 it into words it if is multi-word, otherwise split it into bytes. */
1933 if (size > 1)
1935 enum machine_mode omode, imode;
1936 unsigned int subalign;
1937 unsigned int subsize, i;
1939 subsize = size > UNITS_PER_WORD? UNITS_PER_WORD : 1;
1940 subalign = MIN (align, subsize * BITS_PER_UNIT);
1941 omode = mode_for_size (subsize * BITS_PER_UNIT, MODE_INT, 0);
1942 imode = mode_for_size (size * BITS_PER_UNIT, MODE_INT, 0);
1944 for (i = 0; i < size; i += subsize)
1946 rtx partial = simplify_subreg (omode, x, imode, i);
1947 if (!partial || !assemble_integer (partial, subsize, subalign, 0))
1948 break;
1950 if (i == size)
1951 return true;
1953 /* If we've printed some of it, but not all of it, there's no going
1954 back now. */
1955 if (i > 0)
1956 abort ();
1959 if (force)
1960 abort ();
1962 return false;
1965 void
1966 assemble_real (REAL_VALUE_TYPE d, enum machine_mode mode, unsigned int align)
1968 long data[4];
1969 int i;
1970 int bitsize, nelts, nunits, units_per;
1972 /* This is hairy. We have a quantity of known size. real_to_target
1973 will put it into an array of *host* longs, 32 bits per element
1974 (even if long is more than 32 bits). We need to determine the
1975 number of array elements that are occupied (nelts) and the number
1976 of *target* min-addressable units that will be occupied in the
1977 object file (nunits). We cannot assume that 32 divides the
1978 mode's bitsize (size * BITS_PER_UNIT) evenly.
1980 size * BITS_PER_UNIT is used here to make sure that padding bits
1981 (which might appear at either end of the value; real_to_target
1982 will include the padding bits in its output array) are included. */
1984 nunits = GET_MODE_SIZE (mode);
1985 bitsize = nunits * BITS_PER_UNIT;
1986 nelts = CEIL (bitsize, 32);
1987 units_per = 32 / BITS_PER_UNIT;
1989 real_to_target (data, &d, mode);
1991 /* Put out the first word with the specified alignment. */
1992 assemble_integer (GEN_INT (data[0]), MIN (nunits, units_per), align, 1);
1993 nunits -= units_per;
1995 /* Subsequent words need only 32-bit alignment. */
1996 align = min_align (align, 32);
1998 for (i = 1; i < nelts; i++)
2000 assemble_integer (GEN_INT (data[i]), MIN (nunits, units_per), align, 1);
2001 nunits -= units_per;
2005 /* Given an expression EXP with a constant value,
2006 reduce it to the sum of an assembler symbol and an integer.
2007 Store them both in the structure *VALUE.
2008 Abort if EXP does not reduce. */
2010 struct addr_const GTY(())
2012 rtx base;
2013 HOST_WIDE_INT offset;
2016 static void
2017 decode_addr_const (tree exp, struct addr_const *value)
2019 tree target = TREE_OPERAND (exp, 0);
2020 int offset = 0;
2021 rtx x;
2023 while (1)
2025 if (TREE_CODE (target) == COMPONENT_REF
2026 && host_integerp (byte_position (TREE_OPERAND (target, 1)), 0))
2029 offset += int_byte_position (TREE_OPERAND (target, 1));
2030 target = TREE_OPERAND (target, 0);
2032 else if (TREE_CODE (target) == ARRAY_REF
2033 || TREE_CODE (target) == ARRAY_RANGE_REF)
2035 offset += (tree_low_cst (TYPE_SIZE_UNIT (TREE_TYPE (target)), 1)
2036 * tree_low_cst (TREE_OPERAND (target, 1), 0));
2037 target = TREE_OPERAND (target, 0);
2039 else
2040 break;
2043 switch (TREE_CODE (target))
2045 case VAR_DECL:
2046 case FUNCTION_DECL:
2047 x = DECL_RTL (target);
2048 break;
2050 case LABEL_DECL:
2051 x = gen_rtx_MEM (FUNCTION_MODE,
2052 gen_rtx_LABEL_REF (VOIDmode, force_label_rtx (target)));
2053 break;
2055 case REAL_CST:
2056 case STRING_CST:
2057 case COMPLEX_CST:
2058 case CONSTRUCTOR:
2059 case INTEGER_CST:
2060 x = output_constant_def (target, 1);
2061 break;
2063 default:
2064 abort ();
2067 if (GET_CODE (x) != MEM)
2068 abort ();
2069 x = XEXP (x, 0);
2071 value->base = x;
2072 value->offset = offset;
2075 /* We do RTX_UNSPEC + XINT (blah), so nothing can go after RTX_UNSPEC. */
2076 enum kind { RTX_UNKNOWN, RTX_DOUBLE, RTX_VECTOR, RTX_INT, RTX_UNSPEC };
2077 struct rtx_const GTY(())
2079 ENUM_BITFIELD(kind) kind : 16;
2080 ENUM_BITFIELD(machine_mode) mode : 16;
2081 union rtx_const_un {
2082 REAL_VALUE_TYPE GTY ((tag ("4"))) du;
2083 struct rtx_const_u_addr {
2084 rtx base;
2085 const char *symbol;
2086 HOST_WIDE_INT offset;
2087 } GTY ((tag ("1"))) addr;
2088 struct rtx_const_u_di {
2089 HOST_WIDE_INT high;
2090 HOST_WIDE_INT low;
2091 } GTY ((tag ("0"))) di;
2093 /* The max vector size we have is 16 wide; two variants for
2094 integral and floating point vectors. */
2095 struct rtx_const_int_vec {
2096 HOST_WIDE_INT high;
2097 HOST_WIDE_INT low;
2098 } GTY ((tag ("2"))) int_vec[16];
2100 REAL_VALUE_TYPE GTY ((tag ("3"))) fp_vec[8];
2102 } GTY ((desc ("%1.kind >= RTX_INT"), descbits ("1"))) un;
2105 /* Uniquize all constants that appear in memory.
2106 Each constant in memory thus far output is recorded
2107 in `const_desc_table'. */
2109 struct constant_descriptor_tree GTY(())
2111 /* A MEM for the constant. */
2112 rtx rtl;
2114 /* The value of the constant. */
2115 tree value;
2118 static GTY((param_is (struct constant_descriptor_tree)))
2119 htab_t const_desc_htab;
2121 static struct constant_descriptor_tree * build_constant_desc (tree);
2122 static void maybe_output_constant_def_contents (struct constant_descriptor_tree *, int);
2124 /* Compute a hash code for a constant expression. */
2126 static hashval_t
2127 const_desc_hash (const void *ptr)
2129 return const_hash_1 (((struct constant_descriptor_tree *)ptr)->value);
2132 static hashval_t
2133 const_hash_1 (const tree exp)
2135 const char *p;
2136 hashval_t hi;
2137 int len, i;
2138 enum tree_code code = TREE_CODE (exp);
2140 /* Either set P and LEN to the address and len of something to hash and
2141 exit the switch or return a value. */
2143 switch (code)
2145 case INTEGER_CST:
2146 p = (char *) &TREE_INT_CST (exp);
2147 len = sizeof TREE_INT_CST (exp);
2148 break;
2150 case REAL_CST:
2151 return real_hash (TREE_REAL_CST_PTR (exp));
2153 case STRING_CST:
2154 if (flag_writable_strings)
2156 p = (char *) &exp;
2157 len = sizeof exp;
2159 else
2161 p = TREE_STRING_POINTER (exp);
2162 len = TREE_STRING_LENGTH (exp);
2164 break;
2166 case COMPLEX_CST:
2167 return (const_hash_1 (TREE_REALPART (exp)) * 5
2168 + const_hash_1 (TREE_IMAGPART (exp)));
2170 case CONSTRUCTOR:
2171 if (TREE_CODE (TREE_TYPE (exp)) == SET_TYPE)
2173 char *tmp;
2175 len = int_size_in_bytes (TREE_TYPE (exp));
2176 tmp = alloca (len);
2177 get_set_constructor_bytes (exp, (unsigned char *) tmp, len);
2178 p = tmp;
2179 break;
2181 else
2183 tree link;
2185 hi = 5 + int_size_in_bytes (TREE_TYPE (exp));
2187 for (link = CONSTRUCTOR_ELTS (exp); link; link = TREE_CHAIN (link))
2188 if (TREE_VALUE (link))
2189 hi = hi * 603 + const_hash_1 (TREE_VALUE (link));
2191 return hi;
2194 case ADDR_EXPR:
2195 case FDESC_EXPR:
2197 struct addr_const value;
2199 decode_addr_const (exp, &value);
2200 if (GET_CODE (value.base) == SYMBOL_REF)
2202 /* Don't hash the address of the SYMBOL_REF;
2203 only use the offset and the symbol name. */
2204 hi = value.offset;
2205 p = XSTR (value.base, 0);
2206 for (i = 0; p[i] != 0; i++)
2207 hi = ((hi * 613) + (unsigned) (p[i]));
2209 else if (GET_CODE (value.base) == LABEL_REF)
2210 hi = value.offset + CODE_LABEL_NUMBER (XEXP (value.base, 0)) * 13;
2211 else
2212 abort ();
2214 return hi;
2216 case PLUS_EXPR:
2217 case MINUS_EXPR:
2218 return (const_hash_1 (TREE_OPERAND (exp, 0)) * 9
2219 + const_hash_1 (TREE_OPERAND (exp, 1)));
2221 case NOP_EXPR:
2222 case CONVERT_EXPR:
2223 case NON_LVALUE_EXPR:
2224 return const_hash_1 (TREE_OPERAND (exp, 0)) * 7 + 2;
2226 default:
2227 /* A language specific constant. Just hash the code. */
2228 return code;
2231 /* Compute hashing function. */
2232 hi = len;
2233 for (i = 0; i < len; i++)
2234 hi = ((hi * 613) + (unsigned) (p[i]));
2236 return hi;
2239 /* Wrapper of compare_constant, for the htab interface. */
2240 static int
2241 const_desc_eq (const void *p1, const void *p2)
2243 return compare_constant (((struct constant_descriptor_tree *)p1)->value,
2244 ((struct constant_descriptor_tree *)p2)->value);
2247 /* Compare t1 and t2, and return 1 only if they are known to result in
2248 the same bit pattern on output. */
2250 static int
2251 compare_constant (const tree t1, const tree t2)
2253 enum tree_code typecode;
2255 if (t1 == NULL_TREE)
2256 return t2 == NULL_TREE;
2257 if (t2 == NULL_TREE)
2258 return 0;
2260 if (TREE_CODE (t1) != TREE_CODE (t2))
2261 return 0;
2263 switch (TREE_CODE (t1))
2265 case INTEGER_CST:
2266 /* Integer constants are the same only if the same width of type. */
2267 if (TYPE_PRECISION (TREE_TYPE (t1)) != TYPE_PRECISION (TREE_TYPE (t2)))
2268 return 0;
2269 return tree_int_cst_equal (t1, t2);
2271 case REAL_CST:
2272 /* Real constants are the same only if the same width of type. */
2273 if (TYPE_PRECISION (TREE_TYPE (t1)) != TYPE_PRECISION (TREE_TYPE (t2)))
2274 return 0;
2276 return REAL_VALUES_IDENTICAL (TREE_REAL_CST (t1), TREE_REAL_CST (t2));
2278 case STRING_CST:
2279 if (flag_writable_strings)
2280 return t1 == t2;
2282 if (TYPE_MODE (TREE_TYPE (t1)) != TYPE_MODE (TREE_TYPE (t2)))
2283 return 0;
2285 return (TREE_STRING_LENGTH (t1) == TREE_STRING_LENGTH (t2)
2286 && ! memcmp (TREE_STRING_POINTER (t1), TREE_STRING_POINTER (t2),
2287 TREE_STRING_LENGTH (t1)));
2289 case COMPLEX_CST:
2290 return (compare_constant (TREE_REALPART (t1), TREE_REALPART (t2))
2291 && compare_constant (TREE_IMAGPART (t1), TREE_IMAGPART (t2)));
2293 case CONSTRUCTOR:
2294 typecode = TREE_CODE (TREE_TYPE (t1));
2295 if (typecode != TREE_CODE (TREE_TYPE (t2)))
2296 return 0;
2298 if (typecode == SET_TYPE)
2300 int len = int_size_in_bytes (TREE_TYPE (t2));
2301 unsigned char *tmp1, *tmp2;
2303 if (int_size_in_bytes (TREE_TYPE (t1)) != len)
2304 return 0;
2306 tmp1 = alloca (len);
2307 tmp2 = alloca (len);
2309 if (get_set_constructor_bytes (t1, tmp1, len) != NULL_TREE)
2310 return 0;
2311 if (get_set_constructor_bytes (t2, tmp2, len) != NULL_TREE)
2312 return 0;
2314 return memcmp (tmp1, tmp2, len) == 0;
2316 else
2318 tree l1, l2;
2320 if (typecode == ARRAY_TYPE)
2322 HOST_WIDE_INT size_1 = int_size_in_bytes (TREE_TYPE (t1));
2323 /* For arrays, check that the sizes all match. */
2324 if (TYPE_MODE (TREE_TYPE (t1)) != TYPE_MODE (TREE_TYPE (t2))
2325 || size_1 == -1
2326 || size_1 != int_size_in_bytes (TREE_TYPE (t2)))
2327 return 0;
2329 else
2331 /* For record and union constructors, require exact type
2332 equality. */
2333 if (TREE_TYPE (t1) != TREE_TYPE (t2))
2334 return 0;
2337 for (l1 = CONSTRUCTOR_ELTS (t1), l2 = CONSTRUCTOR_ELTS (t2);
2338 l1 && l2;
2339 l1 = TREE_CHAIN (l1), l2 = TREE_CHAIN (l2))
2341 /* Check that each value is the same... */
2342 if (! compare_constant (TREE_VALUE (l1), TREE_VALUE (l2)))
2343 return 0;
2344 /* ... and that they apply to the same fields! */
2345 if (typecode == ARRAY_TYPE)
2347 if (! compare_constant (TREE_PURPOSE (l1),
2348 TREE_PURPOSE (l2)))
2349 return 0;
2351 else
2353 if (TREE_PURPOSE (l1) != TREE_PURPOSE (l2))
2354 return 0;
2358 return l1 == NULL_TREE && l2 == NULL_TREE;
2361 case ADDR_EXPR:
2362 case FDESC_EXPR:
2364 struct addr_const value1, value2;
2366 decode_addr_const (t1, &value1);
2367 decode_addr_const (t2, &value2);
2368 return (value1.offset == value2.offset
2369 && strcmp (XSTR (value1.base, 0), XSTR (value2.base, 0)) == 0);
2372 case PLUS_EXPR:
2373 case MINUS_EXPR:
2374 case RANGE_EXPR:
2375 return (compare_constant (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0))
2376 && compare_constant(TREE_OPERAND (t1, 1), TREE_OPERAND (t2, 1)));
2378 case NOP_EXPR:
2379 case CONVERT_EXPR:
2380 case NON_LVALUE_EXPR:
2381 return compare_constant (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
2383 default:
2385 tree nt1, nt2;
2386 nt1 = (*lang_hooks.expand_constant) (t1);
2387 nt2 = (*lang_hooks.expand_constant) (t2);
2388 if (nt1 != t1 || nt2 != t2)
2389 return compare_constant (nt1, nt2);
2390 else
2391 return 0;
2395 /* Should not get here. */
2396 abort ();
2399 /* Make a copy of the whole tree structure for a constant. This
2400 handles the same types of nodes that compare_constant handles.
2401 Writable string constants are never copied. */
2403 static tree
2404 copy_constant (tree exp)
2406 switch (TREE_CODE (exp))
2408 case ADDR_EXPR:
2409 /* For ADDR_EXPR, we do not want to copy the decl whose address
2410 is requested. We do want to copy constants though. */
2411 if (TREE_CODE_CLASS (TREE_CODE (TREE_OPERAND (exp, 0))) == 'c')
2412 return build1 (TREE_CODE (exp), TREE_TYPE (exp),
2413 copy_constant (TREE_OPERAND (exp, 0)));
2414 else
2415 return copy_node (exp);
2417 case STRING_CST:
2418 if (flag_writable_strings)
2419 return exp;
2420 /* FALLTHROUGH */
2421 case INTEGER_CST:
2422 case REAL_CST:
2423 return copy_node (exp);
2425 case COMPLEX_CST:
2426 return build_complex (TREE_TYPE (exp),
2427 copy_constant (TREE_REALPART (exp)),
2428 copy_constant (TREE_IMAGPART (exp)));
2430 case PLUS_EXPR:
2431 case MINUS_EXPR:
2432 return build (TREE_CODE (exp), TREE_TYPE (exp),
2433 copy_constant (TREE_OPERAND (exp, 0)),
2434 copy_constant (TREE_OPERAND (exp, 1)));
2436 case NOP_EXPR:
2437 case CONVERT_EXPR:
2438 case NON_LVALUE_EXPR:
2439 case VIEW_CONVERT_EXPR:
2440 return build1 (TREE_CODE (exp), TREE_TYPE (exp),
2441 copy_constant (TREE_OPERAND (exp, 0)));
2443 case CONSTRUCTOR:
2445 tree copy = copy_node (exp);
2446 tree list = copy_list (CONSTRUCTOR_ELTS (exp));
2447 tree tail;
2449 CONSTRUCTOR_ELTS (copy) = list;
2450 for (tail = list; tail; tail = TREE_CHAIN (tail))
2451 TREE_VALUE (tail) = copy_constant (TREE_VALUE (tail));
2452 if (TREE_CODE (TREE_TYPE (exp)) == SET_TYPE)
2453 for (tail = list; tail; tail = TREE_CHAIN (tail))
2454 TREE_PURPOSE (tail) = copy_constant (TREE_PURPOSE (tail));
2456 return copy;
2459 default:
2461 tree t;
2462 t = (*lang_hooks.expand_constant) (exp);
2463 if (t != exp)
2464 return copy_constant (t);
2465 else
2466 abort ();
2471 /* Subroutine of output_constant_def:
2472 No constant equal to EXP is known to have been output.
2473 Make a constant descriptor to enter EXP in the hash table.
2474 Assign the label number and construct RTL to refer to the
2475 constant's location in memory.
2476 Caller is responsible for updating the hash table. */
2478 static struct constant_descriptor_tree *
2479 build_constant_desc (tree exp)
2481 rtx symbol;
2482 rtx rtl;
2483 char label[256];
2484 int labelno;
2485 struct constant_descriptor_tree *desc;
2487 desc = ggc_alloc (sizeof (*desc));
2488 desc->value = copy_constant (exp);
2490 /* Create a string containing the label name, in LABEL. */
2491 labelno = const_labelno++;
2492 ASM_GENERATE_INTERNAL_LABEL (label, "LC", labelno);
2494 /* We have a symbol name; construct the SYMBOL_REF and the MEM. */
2495 symbol = gen_rtx_SYMBOL_REF (Pmode, ggc_strdup (label));
2496 SYMBOL_REF_FLAGS (symbol) = SYMBOL_FLAG_LOCAL;
2497 SYMBOL_REF_DECL (symbol) = desc->value;
2498 TREE_CONSTANT_POOL_ADDRESS_P (symbol) = 1;
2500 rtl = gen_rtx_MEM (TYPE_MODE (TREE_TYPE (exp)), symbol);
2501 set_mem_attributes (rtl, exp, 1);
2502 set_mem_alias_set (rtl, 0);
2503 set_mem_alias_set (rtl, const_alias_set);
2505 /* Set flags or add text to the name to record information, such as
2506 that it is a local symbol. If the name is changed, the macro
2507 ASM_OUTPUT_LABELREF will have to know how to strip this
2508 information. This call might invalidate our local variable
2509 SYMBOL; we can't use it afterward. */
2511 (*targetm.encode_section_info) (exp, rtl, true);
2513 desc->rtl = rtl;
2515 return desc;
2518 /* Return an rtx representing a reference to constant data in memory
2519 for the constant expression EXP.
2521 If assembler code for such a constant has already been output,
2522 return an rtx to refer to it.
2523 Otherwise, output such a constant in memory
2524 and generate an rtx for it.
2526 If DEFER is nonzero, this constant can be deferred and output only
2527 if referenced in the function after all optimizations.
2529 `const_desc_table' records which constants already have label strings. */
2532 output_constant_def (tree exp, int defer)
2534 struct constant_descriptor_tree *desc;
2535 struct constant_descriptor_tree key;
2536 void **loc;
2538 /* Look up EXP in the table of constant descriptors. If we didn't find
2539 it, create a new one. */
2540 key.value = exp;
2541 loc = htab_find_slot (const_desc_htab, &key, INSERT);
2543 desc = *loc;
2544 if (desc == 0)
2546 desc = build_constant_desc (exp);
2547 *loc = desc;
2550 maybe_output_constant_def_contents (desc, defer);
2551 return desc->rtl;
2554 /* Subroutine of output_constant_def: Decide whether or not we need to
2555 output the constant DESC now, and if so, do it. */
2556 static void
2557 maybe_output_constant_def_contents (struct constant_descriptor_tree *desc,
2558 int defer)
2560 rtx symbol = XEXP (desc->rtl, 0);
2561 tree exp = desc->value;
2563 if (flag_syntax_only)
2564 return;
2566 if (TREE_ASM_WRITTEN (exp))
2567 /* Already output; don't do it again. */
2568 return;
2570 /* The only constants that cannot safely be deferred, assuming the
2571 context allows it, are strings under flag_writable_strings. */
2572 if (defer && (TREE_CODE (exp) != STRING_CST || !flag_writable_strings))
2574 /* Increment n_deferred_constants if it exists. It needs to be at
2575 least as large as the number of constants actually referred to
2576 by the function. If it's too small we'll stop looking too early
2577 and fail to emit constants; if it's too large we'll only look
2578 through the entire function when we could have stopped earlier. */
2579 if (cfun)
2580 n_deferred_constants++;
2581 return;
2584 output_constant_def_contents (symbol);
2587 /* We must output the constant data referred to by SYMBOL; do so. */
2589 static void
2590 output_constant_def_contents (rtx symbol)
2592 tree exp = SYMBOL_REF_DECL (symbol);
2593 const char *label = XSTR (symbol, 0);
2594 HOST_WIDE_INT size;
2596 /* Make sure any other constants whose addresses appear in EXP
2597 are assigned label numbers. */
2598 int reloc = compute_reloc_for_constant (exp);
2600 /* Align the location counter as required by EXP's data type. */
2601 int align = TYPE_ALIGN (TREE_TYPE (exp));
2602 #ifdef CONSTANT_ALIGNMENT
2603 align = CONSTANT_ALIGNMENT (exp, align);
2604 #endif
2606 output_addressed_constants (exp);
2608 /* We are no longer deferring this constant. */
2609 TREE_ASM_WRITTEN (exp) = 1;
2611 if (IN_NAMED_SECTION (exp))
2612 named_section (exp, NULL, reloc);
2613 else
2614 (*targetm.asm_out.select_section) (exp, reloc, align);
2616 if (align > BITS_PER_UNIT)
2618 ASM_OUTPUT_ALIGN (asm_out_file, floor_log2 (align / BITS_PER_UNIT));
2621 size = int_size_in_bytes (TREE_TYPE (exp));
2622 if (TREE_CODE (exp) == STRING_CST)
2623 size = MAX (TREE_STRING_LENGTH (exp), size);
2625 /* Do any machine/system dependent processing of the constant. */
2626 #ifdef ASM_DECLARE_CONSTANT_NAME
2627 ASM_DECLARE_CONSTANT_NAME (asm_out_file, label, exp, size);
2628 #else
2629 /* Standard thing is just output label for the constant. */
2630 ASM_OUTPUT_LABEL (asm_out_file, label);
2631 #endif /* ASM_DECLARE_CONSTANT_NAME */
2633 /* Output the value of EXP. */
2634 output_constant (exp, size, align);
2637 /* A constant which was deferred in its original location has been
2638 inserted by the RTL inliner into a different function. The
2639 current function's deferred constant count must be incremented. */
2640 void
2641 notice_rtl_inlining_of_deferred_constant (void)
2643 n_deferred_constants++;
2646 /* Look up EXP in the table of constant descriptors. Return the rtl
2647 if it has been emitted, else null. */
2650 lookup_constant_def (tree exp)
2652 struct constant_descriptor_tree *desc;
2653 struct constant_descriptor_tree key;
2655 key.value = exp;
2656 desc = htab_find (const_desc_htab, &key);
2658 return (desc ? desc->rtl : NULL_RTX);
2661 /* Used in the hash tables to avoid outputting the same constant
2662 twice. Unlike 'struct constant_descriptor_tree', RTX constants
2663 are output once per function, not once per file; there seems
2664 to be no reason for the difference. */
2666 struct constant_descriptor_rtx GTY(())
2668 /* More constant_descriptors with the same hash code. */
2669 struct constant_descriptor_rtx *next;
2671 /* A MEM for the constant. */
2672 rtx rtl;
2674 /* The value of the constant. */
2675 struct rtx_const value;
2678 /* Structure to represent sufficient information about a constant so that
2679 it can be output when the constant pool is output, so that function
2680 integration can be done, and to simplify handling on machines that reference
2681 constant pool as base+displacement. */
2683 struct pool_constant GTY(())
2685 struct constant_descriptor_rtx *desc;
2686 struct pool_constant *next;
2687 struct pool_constant *next_sym;
2688 rtx constant;
2689 enum machine_mode mode;
2690 int labelno;
2691 unsigned int align;
2692 HOST_WIDE_INT offset;
2693 int mark;
2696 /* Hash code for a SYMBOL_REF with CONSTANT_POOL_ADDRESS_P true.
2697 The argument is XSTR (... , 0) */
2699 #define SYMHASH(LABEL) (((unsigned long) (LABEL)) % MAX_RTX_HASH_TABLE)
2701 /* Initialize constant pool hashing for a new function. */
2703 void
2704 init_varasm_status (struct function *f)
2706 struct varasm_status *p;
2707 p = ggc_alloc (sizeof (struct varasm_status));
2708 f->varasm = p;
2709 p->x_const_rtx_hash_table
2710 = ggc_alloc_cleared (MAX_RTX_HASH_TABLE
2711 * sizeof (struct constant_descriptor_rtx *));
2712 p->x_const_rtx_sym_hash_table
2713 = ggc_alloc_cleared (MAX_RTX_HASH_TABLE
2714 * sizeof (struct pool_constant *));
2716 p->x_first_pool = p->x_last_pool = 0;
2717 p->x_pool_offset = 0;
2718 p->deferred_constants = 0;
2722 /* Express an rtx for a constant integer (perhaps symbolic)
2723 as the sum of a symbol or label plus an explicit integer.
2724 They are stored into VALUE. */
2726 static void
2727 decode_rtx_const (enum machine_mode mode, rtx x, struct rtx_const *value)
2729 /* Clear the whole structure, including any gaps. */
2730 memset (value, 0, sizeof (struct rtx_const));
2732 value->kind = RTX_INT; /* Most usual kind. */
2733 value->mode = mode;
2735 switch (GET_CODE (x))
2737 case CONST_DOUBLE:
2738 value->kind = RTX_DOUBLE;
2739 if (GET_MODE (x) != VOIDmode)
2741 const REAL_VALUE_TYPE *r = CONST_DOUBLE_REAL_VALUE (x);
2743 value->mode = GET_MODE (x);
2745 /* Copy the REAL_VALUE_TYPE by members so that we don't
2746 copy garbage from the original structure into our
2747 carefully cleaned hashing structure. */
2748 value->un.du.class = r->class;
2749 value->un.du.sign = r->sign;
2750 switch (r->class)
2752 case rvc_zero:
2753 case rvc_inf:
2754 break;
2755 case rvc_normal:
2756 value->un.du.exp = r->exp;
2757 /* Fall through. */
2758 case rvc_nan:
2759 memcpy (value->un.du.sig, r->sig, sizeof (r->sig));
2760 break;
2761 default:
2762 abort ();
2765 else
2767 value->un.di.low = CONST_DOUBLE_LOW (x);
2768 value->un.di.high = CONST_DOUBLE_HIGH (x);
2770 break;
2772 case CONST_VECTOR:
2774 int units, i;
2776 units = CONST_VECTOR_NUNITS (x);
2777 value->kind = RTX_VECTOR;
2778 value->mode = mode;
2780 if (GET_MODE_CLASS (mode) == MODE_VECTOR_INT)
2782 for (i = 0; i < units; ++i)
2784 rtx elt = CONST_VECTOR_ELT (x, i);
2785 if (GET_CODE (elt) == CONST_INT)
2787 value->un.int_vec[i].low = INTVAL (elt);
2788 value->un.int_vec[i].high = 0;
2790 else
2792 value->un.int_vec[i].low = CONST_DOUBLE_LOW (elt);
2793 value->un.int_vec[i].high = CONST_DOUBLE_HIGH (elt);
2797 else if (GET_MODE_CLASS (mode) == MODE_VECTOR_FLOAT)
2799 for (i = 0; i < units; ++i)
2801 const REAL_VALUE_TYPE *r
2802 = CONST_DOUBLE_REAL_VALUE (CONST_VECTOR_ELT (x, i));
2803 REAL_VALUE_TYPE *d = &value->un.fp_vec[i];
2805 /* Copy the REAL_VALUE_TYPE by members so that we don't
2806 copy garbage from the original structure into our
2807 carefully cleaned hashing structure. */
2808 d->class = r->class;
2809 d->sign = r->sign;
2810 switch (r->class)
2812 case rvc_zero:
2813 case rvc_inf:
2814 break;
2815 case rvc_normal:
2816 d->exp = r->exp;
2817 /* Fall through. */
2818 case rvc_nan:
2819 memcpy (d->sig, r->sig, sizeof (r->sig));
2820 break;
2821 default:
2822 abort ();
2826 else
2827 abort ();
2829 break;
2831 case CONST_INT:
2832 value->un.addr.offset = INTVAL (x);
2833 break;
2835 case SYMBOL_REF:
2836 case LABEL_REF:
2837 case PC:
2838 value->un.addr.base = x;
2839 break;
2841 case CONST:
2842 x = XEXP (x, 0);
2843 if (GET_CODE (x) == PLUS && GET_CODE (XEXP (x, 1)) == CONST_INT)
2845 value->un.addr.base = XEXP (x, 0);
2846 value->un.addr.offset = INTVAL (XEXP (x, 1));
2848 else if (GET_CODE (x) == MINUS && GET_CODE (XEXP (x, 1)) == CONST_INT)
2850 value->un.addr.base = XEXP (x, 0);
2851 value->un.addr.offset = - INTVAL (XEXP (x, 1));
2853 else
2855 value->un.addr.base = x;
2856 value->un.addr.offset = 0;
2858 break;
2860 default:
2861 value->kind = RTX_UNKNOWN;
2862 break;
2865 if (value->kind == RTX_INT && value->un.addr.base != 0
2866 && GET_CODE (value->un.addr.base) == UNSPEC)
2868 /* For a simple UNSPEC, the base is set to the
2869 operand, the kind field is set to the index of
2870 the unspec expression.
2871 Together with the code below, in case that
2872 the operand is a SYMBOL_REF or LABEL_REF,
2873 the address of the string or the code_label
2874 is taken as base. */
2875 if (XVECLEN (value->un.addr.base, 0) == 1)
2877 value->kind = RTX_UNSPEC + XINT (value->un.addr.base, 1);
2878 value->un.addr.base = XVECEXP (value->un.addr.base, 0, 0);
2882 if (value->kind >= RTX_INT && value->un.addr.base != 0)
2883 switch (GET_CODE (value->un.addr.base))
2885 case SYMBOL_REF:
2886 /* Use the string's address, not the SYMBOL_REF's address,
2887 for the sake of addresses of library routines. */
2888 value->un.addr.symbol = XSTR (value->un.addr.base, 0);
2889 value->un.addr.base = NULL_RTX;
2890 break;
2892 case LABEL_REF:
2893 /* For a LABEL_REF, compare labels. */
2894 value->un.addr.base = XEXP (value->un.addr.base, 0);
2896 default:
2897 break;
2901 /* Given a MINUS expression, simplify it if both sides
2902 include the same symbol. */
2905 simplify_subtraction (rtx x)
2907 struct rtx_const val0, val1;
2909 decode_rtx_const (GET_MODE (x), XEXP (x, 0), &val0);
2910 decode_rtx_const (GET_MODE (x), XEXP (x, 1), &val1);
2912 if (val0.kind >= RTX_INT
2913 && val0.kind == val1.kind
2914 && val0.un.addr.base == val1.un.addr.base
2915 && val0.un.addr.symbol == val1.un.addr.symbol)
2916 return GEN_INT (val0.un.addr.offset - val1.un.addr.offset);
2918 return x;
2921 /* Compute a hash code for a constant RTL expression. */
2923 static unsigned int
2924 const_hash_rtx (enum machine_mode mode, rtx x)
2926 union {
2927 struct rtx_const value;
2928 unsigned int data[sizeof(struct rtx_const) / sizeof (unsigned int)];
2929 } u;
2931 unsigned int hi;
2932 size_t i;
2934 decode_rtx_const (mode, x, &u.value);
2936 /* Compute hashing function. */
2937 hi = 0;
2938 for (i = 0; i < ARRAY_SIZE (u.data); i++)
2939 hi = hi * 613 + u.data[i];
2941 return hi % MAX_RTX_HASH_TABLE;
2944 /* Compare a constant rtl object X with a constant-descriptor DESC.
2945 Return 1 if DESC describes a constant with the same value as X. */
2947 static int
2948 compare_constant_rtx (enum machine_mode mode, rtx x,
2949 struct constant_descriptor_rtx *desc)
2951 struct rtx_const value;
2953 decode_rtx_const (mode, x, &value);
2955 /* Compare constant contents. */
2956 return memcmp (&value, &desc->value, sizeof (struct rtx_const)) == 0;
2959 /* Construct a constant descriptor for the rtl-expression X.
2960 It is up to the caller to enter the descriptor in the hash table. */
2962 static struct constant_descriptor_rtx *
2963 record_constant_rtx (enum machine_mode mode, rtx x)
2965 struct constant_descriptor_rtx *ptr;
2967 ptr = ggc_alloc (sizeof (*ptr));
2968 decode_rtx_const (mode, x, &ptr->value);
2970 return ptr;
2973 /* Given a constant rtx X, make (or find) a memory constant for its value
2974 and return a MEM rtx to refer to it in memory. */
2977 force_const_mem (enum machine_mode mode, rtx x)
2979 int hash;
2980 struct constant_descriptor_rtx *desc;
2981 char label[256];
2982 rtx def, symbol;
2983 struct pool_constant *pool;
2984 unsigned int align;
2986 /* If we're not allowed to drop X into the constant pool, don't. */
2987 if ((*targetm.cannot_force_const_mem) (x))
2988 return NULL_RTX;
2990 /* Compute hash code of X. Search the descriptors for that hash code
2991 to see if any of them describes X. If yes, we have an rtx to use. */
2992 hash = const_hash_rtx (mode, x);
2993 for (desc = const_rtx_hash_table[hash]; desc; desc = desc->next)
2994 if (compare_constant_rtx (mode, x, desc))
2995 return copy_rtx (desc->rtl);
2997 /* No constant equal to X is known to have been output.
2998 Make a constant descriptor to enter X in the hash table
2999 and make a MEM for it. */
3000 desc = record_constant_rtx (mode, x);
3001 desc->next = const_rtx_hash_table[hash];
3002 const_rtx_hash_table[hash] = desc;
3004 /* Align the location counter as required by EXP's data type. */
3005 align = GET_MODE_ALIGNMENT (mode == VOIDmode ? word_mode : mode);
3006 #ifdef CONSTANT_ALIGNMENT
3008 tree type = (*lang_hooks.types.type_for_mode) (mode, 0);
3009 if (type != NULL_TREE)
3010 align = CONSTANT_ALIGNMENT (make_tree (type, x), align);
3012 #endif
3014 pool_offset += (align / BITS_PER_UNIT) - 1;
3015 pool_offset &= ~ ((align / BITS_PER_UNIT) - 1);
3017 if (GET_CODE (x) == LABEL_REF)
3018 LABEL_PRESERVE_P (XEXP (x, 0)) = 1;
3020 /* Allocate a pool constant descriptor, fill it in, and chain it in. */
3021 pool = ggc_alloc (sizeof (struct pool_constant));
3022 pool->desc = desc;
3023 pool->constant = x;
3024 pool->mode = mode;
3025 pool->labelno = const_labelno;
3026 pool->align = align;
3027 pool->offset = pool_offset;
3028 pool->mark = 1;
3029 pool->next = 0;
3031 if (last_pool == 0)
3032 first_pool = pool;
3033 else
3034 last_pool->next = pool;
3036 last_pool = pool;
3037 pool_offset += GET_MODE_SIZE (mode);
3039 /* Create a string containing the label name, in LABEL. */
3040 ASM_GENERATE_INTERNAL_LABEL (label, "LC", const_labelno);
3042 ++const_labelno;
3044 /* Construct the SYMBOL_REF and the MEM. */
3046 symbol = gen_rtx_SYMBOL_REF (Pmode, ggc_strdup (label));
3047 SYMBOL_REF_FLAGS (symbol) = SYMBOL_FLAG_LOCAL;
3049 pool->desc->rtl = def = gen_rtx_MEM (mode, symbol);
3050 set_mem_attributes (def, (*lang_hooks.types.type_for_mode) (mode, 0), 1);
3051 RTX_UNCHANGING_P (def) = 1;
3053 /* Add label to symbol hash table. */
3054 hash = SYMHASH (XSTR (symbol, 0));
3055 pool->next_sym = const_rtx_sym_hash_table[hash];
3056 const_rtx_sym_hash_table[hash] = pool;
3058 /* Mark the symbol_ref as belonging to this constants pool. */
3059 CONSTANT_POOL_ADDRESS_P (symbol) = 1;
3060 SYMBOL_REF_FLAGS (symbol) = SYMBOL_FLAG_LOCAL;
3061 current_function_uses_const_pool = 1;
3063 return copy_rtx (def);
3066 /* Given a SYMBOL_REF with CONSTANT_POOL_ADDRESS_P true, return a pointer to
3067 the corresponding pool_constant structure. */
3069 static struct pool_constant *
3070 find_pool_constant (struct function *f, rtx addr)
3072 struct pool_constant *pool;
3073 const char *label = XSTR (addr, 0);
3075 for (pool = f->varasm->x_const_rtx_sym_hash_table[SYMHASH (label)]; pool;
3076 pool = pool->next_sym)
3077 if (XSTR (XEXP (pool->desc->rtl, 0), 0) == label)
3078 return pool;
3080 abort ();
3083 /* Given a constant pool SYMBOL_REF, return the corresponding constant. */
3086 get_pool_constant (rtx addr)
3088 return (find_pool_constant (cfun, addr))->constant;
3091 /* Given a constant pool SYMBOL_REF, return the corresponding constant
3092 and whether it has been output or not. */
3095 get_pool_constant_mark (rtx addr, bool *pmarked)
3097 struct pool_constant *pool = find_pool_constant (cfun, addr);
3098 *pmarked = (pool->mark != 0);
3099 return pool->constant;
3102 /* Likewise, but for the constant pool of a specific function. */
3105 get_pool_constant_for_function (struct function *f, rtx addr)
3107 return (find_pool_constant (f, addr))->constant;
3110 /* Similar, return the mode. */
3112 enum machine_mode
3113 get_pool_mode (rtx addr)
3115 return (find_pool_constant (cfun, addr))->mode;
3118 enum machine_mode
3119 get_pool_mode_for_function (struct function *f, rtx addr)
3121 return (find_pool_constant (f, addr))->mode;
3124 /* Similar, return the offset in the constant pool. */
3127 get_pool_offset (rtx addr)
3129 return (find_pool_constant (cfun, addr))->offset;
3132 /* Return the size of the constant pool. */
3135 get_pool_size (void)
3137 return pool_offset;
3140 /* Write all the constants in the constant pool. */
3142 void
3143 output_constant_pool (const char *fnname ATTRIBUTE_UNUSED,
3144 tree fndecl ATTRIBUTE_UNUSED)
3146 struct pool_constant *pool;
3147 rtx x;
3148 REAL_VALUE_TYPE r;
3150 /* It is possible for gcc to call force_const_mem and then to later
3151 discard the instructions which refer to the constant. In such a
3152 case we do not need to output the constant. */
3153 mark_constant_pool ();
3155 #ifdef ASM_OUTPUT_POOL_PROLOGUE
3156 ASM_OUTPUT_POOL_PROLOGUE (asm_out_file, fnname, fndecl, pool_offset);
3157 #endif
3159 for (pool = first_pool; pool; pool = pool->next)
3161 rtx tmp;
3163 x = pool->constant;
3165 if (! pool->mark)
3166 continue;
3168 /* See if X is a LABEL_REF (or a CONST referring to a LABEL_REF)
3169 whose CODE_LABEL has been deleted. This can occur if a jump table
3170 is eliminated by optimization. If so, write a constant of zero
3171 instead. Note that this can also happen by turning the
3172 CODE_LABEL into a NOTE. */
3173 /* ??? This seems completely and utterly wrong. Certainly it's
3174 not true for NOTE_INSN_DELETED_LABEL, but I disbelieve proper
3175 functioning even with INSN_DELETED_P and friends. */
3177 tmp = x;
3178 switch (GET_CODE (x))
3180 case CONST:
3181 if (GET_CODE (XEXP (x, 0)) != PLUS
3182 || GET_CODE (XEXP (XEXP (x, 0), 0)) != LABEL_REF)
3183 break;
3184 tmp = XEXP (XEXP (x, 0), 0);
3185 /* Fall through. */
3187 case LABEL_REF:
3188 tmp = XEXP (x, 0);
3189 if (INSN_DELETED_P (tmp)
3190 || (GET_CODE (tmp) == NOTE
3191 && NOTE_LINE_NUMBER (tmp) == NOTE_INSN_DELETED))
3193 abort ();
3194 x = const0_rtx;
3196 break;
3198 default:
3199 break;
3202 /* First switch to correct section. */
3203 (*targetm.asm_out.select_rtx_section) (pool->mode, x, pool->align);
3205 #ifdef ASM_OUTPUT_SPECIAL_POOL_ENTRY
3206 ASM_OUTPUT_SPECIAL_POOL_ENTRY (asm_out_file, x, pool->mode,
3207 pool->align, pool->labelno, done);
3208 #endif
3210 assemble_align (pool->align);
3212 /* Output the label. */
3213 (*targetm.asm_out.internal_label) (asm_out_file, "LC", pool->labelno);
3215 /* Output the value of the constant itself. */
3216 switch (GET_MODE_CLASS (pool->mode))
3218 case MODE_FLOAT:
3219 if (GET_CODE (x) != CONST_DOUBLE)
3220 abort ();
3222 REAL_VALUE_FROM_CONST_DOUBLE (r, x);
3223 assemble_real (r, pool->mode, pool->align);
3224 break;
3226 case MODE_INT:
3227 case MODE_PARTIAL_INT:
3228 assemble_integer (x, GET_MODE_SIZE (pool->mode), pool->align, 1);
3229 break;
3231 case MODE_VECTOR_FLOAT:
3233 int i, units;
3234 rtx elt;
3236 if (GET_CODE (x) != CONST_VECTOR)
3237 abort ();
3239 units = CONST_VECTOR_NUNITS (x);
3241 for (i = 0; i < units; i++)
3243 elt = CONST_VECTOR_ELT (x, i);
3244 REAL_VALUE_FROM_CONST_DOUBLE (r, elt);
3245 assemble_real (r, GET_MODE_INNER (pool->mode), pool->align);
3248 break;
3250 case MODE_VECTOR_INT:
3252 int i, units;
3253 rtx elt;
3255 if (GET_CODE (x) != CONST_VECTOR)
3256 abort ();
3258 units = CONST_VECTOR_NUNITS (x);
3260 for (i = 0; i < units; i++)
3262 elt = CONST_VECTOR_ELT (x, i);
3263 assemble_integer (elt, GET_MODE_UNIT_SIZE (pool->mode),
3264 pool->align, 1);
3267 break;
3269 default:
3270 abort ();
3273 /* Make sure all constants in SECTION_MERGE and not SECTION_STRINGS
3274 sections have proper size. */
3275 if (pool->align > GET_MODE_BITSIZE (pool->mode)
3276 && in_section == in_named
3277 && get_named_section_flags (in_named_name) & SECTION_MERGE)
3278 assemble_align (pool->align);
3280 #ifdef ASM_OUTPUT_SPECIAL_POOL_ENTRY
3281 done: ;
3282 #endif
3285 #ifdef ASM_OUTPUT_POOL_EPILOGUE
3286 ASM_OUTPUT_POOL_EPILOGUE (asm_out_file, fnname, fndecl, pool_offset);
3287 #endif
3289 /* Done with this pool. */
3290 first_pool = last_pool = 0;
3293 /* Look through the instructions for this function, and mark all the
3294 entries in the constant pool which are actually being used. Emit
3295 deferred constants which have indeed been used. */
3297 static void
3298 mark_constant_pool (void)
3300 rtx insn;
3301 rtx link;
3302 struct pool_constant *pool;
3304 if (first_pool == 0 && n_deferred_constants == 0)
3305 return;
3307 for (pool = first_pool; pool; pool = pool->next)
3308 pool->mark = 0;
3310 for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
3311 if (INSN_P (insn))
3312 mark_constants (PATTERN (insn));
3314 for (link = current_function_epilogue_delay_list;
3315 link;
3316 link = XEXP (link, 1))
3318 insn = XEXP (link, 0);
3320 if (INSN_P (insn))
3321 mark_constants (PATTERN (insn));
3325 /* Look through appropriate parts of X, marking all entries in the
3326 constant pool which are actually being used. Entries that are only
3327 referenced by other constants are also marked as used. Emit
3328 deferred strings that are used. */
3330 static void
3331 mark_constants (rtx x)
3333 int i;
3334 const char *format_ptr;
3336 if (x == 0)
3337 return;
3339 if (GET_CODE (x) == SYMBOL_REF)
3341 mark_constant (&x, NULL);
3342 return;
3345 /* Insns may appear inside a SEQUENCE. Only check the patterns of
3346 insns, not any notes that may be attached. We don't want to mark
3347 a constant just because it happens to appear in a REG_EQUIV note. */
3348 if (INSN_P (x))
3350 mark_constants (PATTERN (x));
3351 return;
3354 format_ptr = GET_RTX_FORMAT (GET_CODE (x));
3356 for (i = 0; i < GET_RTX_LENGTH (GET_CODE (x)); i++)
3358 switch (*format_ptr++)
3360 case 'e':
3361 mark_constants (XEXP (x, i));
3362 break;
3364 case 'E':
3365 if (XVEC (x, i) != 0)
3367 int j;
3369 for (j = 0; j < XVECLEN (x, i); j++)
3370 mark_constants (XVECEXP (x, i, j));
3372 break;
3374 case 'S':
3375 case 's':
3376 case '0':
3377 case 'i':
3378 case 'w':
3379 case 'n':
3380 case 'u':
3381 case 'B':
3382 break;
3384 default:
3385 abort ();
3390 /* Given a SYMBOL_REF CURRENT_RTX, mark it and all constants it refers
3391 to as used. Emit referenced deferred strings. This function can
3392 be used with for_each_rtx to mark all SYMBOL_REFs in an rtx. */
3394 static int
3395 mark_constant (rtx *current_rtx, void *data ATTRIBUTE_UNUSED)
3397 rtx x = *current_rtx;
3399 if (x == NULL_RTX)
3400 return 0;
3402 else if (GET_CODE (x) == SYMBOL_REF)
3404 if (CONSTANT_POOL_ADDRESS_P (x))
3406 struct pool_constant *pool = find_pool_constant (cfun, x);
3407 if (pool->mark == 0)
3409 pool->mark = 1;
3410 for_each_rtx (&(pool->constant), &mark_constant, NULL);
3412 else
3413 return -1;
3415 else if (TREE_CONSTANT_POOL_ADDRESS_P (x))
3417 tree exp = SYMBOL_REF_DECL (x);
3418 if (!TREE_ASM_WRITTEN (exp))
3420 n_deferred_constants--;
3421 output_constant_def_contents (x);
3425 return 0;
3428 /* Determine what kind of relocations EXP may need. */
3431 compute_reloc_for_constant (tree exp)
3433 int reloc = 0, reloc2;
3434 tree tem;
3436 /* Give the front-end a chance to convert VALUE to something that
3437 looks more like a constant to the back-end. */
3438 exp = (*lang_hooks.expand_constant) (exp);
3440 switch (TREE_CODE (exp))
3442 case ADDR_EXPR:
3443 case FDESC_EXPR:
3444 /* Go inside any operations that get_inner_reference can handle and see
3445 if what's inside is a constant: no need to do anything here for
3446 addresses of variables or functions. */
3447 for (tem = TREE_OPERAND (exp, 0); handled_component_p (tem);
3448 tem = TREE_OPERAND (tem, 0))
3451 if (TREE_PUBLIC (tem))
3452 reloc |= 2;
3453 else
3454 reloc |= 1;
3455 break;
3457 case PLUS_EXPR:
3458 reloc = compute_reloc_for_constant (TREE_OPERAND (exp, 0));
3459 reloc |= compute_reloc_for_constant (TREE_OPERAND (exp, 1));
3460 break;
3462 case MINUS_EXPR:
3463 reloc = compute_reloc_for_constant (TREE_OPERAND (exp, 0));
3464 reloc2 = compute_reloc_for_constant (TREE_OPERAND (exp, 1));
3465 /* The difference of two local labels is computable at link time. */
3466 if (reloc == 1 && reloc2 == 1)
3467 reloc = 0;
3468 else
3469 reloc |= reloc2;
3470 break;
3472 case NOP_EXPR:
3473 case CONVERT_EXPR:
3474 case NON_LVALUE_EXPR:
3475 reloc = compute_reloc_for_constant (TREE_OPERAND (exp, 0));
3476 break;
3478 case CONSTRUCTOR:
3479 for (tem = CONSTRUCTOR_ELTS (exp); tem; tem = TREE_CHAIN (tem))
3480 if (TREE_VALUE (tem) != 0)
3481 reloc |= compute_reloc_for_constant (TREE_VALUE (tem));
3483 break;
3485 default:
3486 break;
3488 return reloc;
3491 /* Find all the constants whose addresses are referenced inside of EXP,
3492 and make sure assembler code with a label has been output for each one.
3493 Indicate whether an ADDR_EXPR has been encountered. */
3495 static void
3496 output_addressed_constants (tree exp)
3498 tree tem;
3500 /* Give the front-end a chance to convert VALUE to something that
3501 looks more like a constant to the back-end. */
3502 exp = (*lang_hooks.expand_constant) (exp);
3504 switch (TREE_CODE (exp))
3506 case ADDR_EXPR:
3507 case FDESC_EXPR:
3508 /* Go inside any operations that get_inner_reference can handle and see
3509 if what's inside is a constant: no need to do anything here for
3510 addresses of variables or functions. */
3511 for (tem = TREE_OPERAND (exp, 0); handled_component_p (tem);
3512 tem = TREE_OPERAND (tem, 0))
3515 if (TREE_CODE_CLASS (TREE_CODE (tem)) == 'c'
3516 || TREE_CODE (tem) == CONSTRUCTOR)
3517 output_constant_def (tem, 0);
3518 break;
3520 case PLUS_EXPR:
3521 case MINUS_EXPR:
3522 output_addressed_constants (TREE_OPERAND (exp, 1));
3523 /* Fall through. */
3525 case NOP_EXPR:
3526 case CONVERT_EXPR:
3527 case NON_LVALUE_EXPR:
3528 output_addressed_constants (TREE_OPERAND (exp, 0));
3529 break;
3531 case CONSTRUCTOR:
3532 for (tem = CONSTRUCTOR_ELTS (exp); tem; tem = TREE_CHAIN (tem))
3533 if (TREE_VALUE (tem) != 0)
3534 output_addressed_constants (TREE_VALUE (tem));
3536 break;
3538 default:
3539 break;
3543 /* Return nonzero if VALUE is a valid constant-valued expression
3544 for use in initializing a static variable; one that can be an
3545 element of a "constant" initializer.
3547 Return null_pointer_node if the value is absolute;
3548 if it is relocatable, return the variable that determines the relocation.
3549 We assume that VALUE has been folded as much as possible;
3550 therefore, we do not need to check for such things as
3551 arithmetic-combinations of integers. */
3553 tree
3554 initializer_constant_valid_p (tree value, tree endtype)
3556 /* Give the front-end a chance to convert VALUE to something that
3557 looks more like a constant to the back-end. */
3558 value = (*lang_hooks.expand_constant) (value);
3560 switch (TREE_CODE (value))
3562 case CONSTRUCTOR:
3563 if ((TREE_CODE (TREE_TYPE (value)) == UNION_TYPE
3564 || TREE_CODE (TREE_TYPE (value)) == RECORD_TYPE)
3565 && TREE_CONSTANT (value)
3566 && CONSTRUCTOR_ELTS (value))
3568 tree elt;
3569 bool absolute = true;
3571 for (elt = CONSTRUCTOR_ELTS (value); elt; elt = TREE_CHAIN (elt))
3573 tree reloc;
3574 value = TREE_VALUE (elt);
3575 reloc = initializer_constant_valid_p (value, TREE_TYPE (value));
3576 if (!reloc)
3577 return NULL_TREE;
3578 if (reloc != null_pointer_node)
3579 absolute = false;
3581 /* For a non-absolute relocation, there is no single
3582 variable that can be "the variable that determines the
3583 relocation." */
3584 return absolute ? null_pointer_node : error_mark_node;
3587 return TREE_STATIC (value) ? null_pointer_node : NULL_TREE;
3589 case INTEGER_CST:
3590 case VECTOR_CST:
3591 case REAL_CST:
3592 case STRING_CST:
3593 case COMPLEX_CST:
3594 return null_pointer_node;
3596 case ADDR_EXPR:
3597 case FDESC_EXPR:
3598 return staticp (TREE_OPERAND (value, 0)) ? TREE_OPERAND (value, 0) : 0;
3600 case VIEW_CONVERT_EXPR:
3601 case NON_LVALUE_EXPR:
3602 return initializer_constant_valid_p (TREE_OPERAND (value, 0), endtype);
3604 case CONVERT_EXPR:
3605 case NOP_EXPR:
3607 tree src;
3608 tree src_type;
3609 tree dest_type;
3611 src = TREE_OPERAND (value, 0);
3612 src_type = TREE_TYPE (src);
3613 dest_type = TREE_TYPE (value);
3615 /* Allow conversions between pointer types, floating-point
3616 types, and offset types. */
3617 if ((POINTER_TYPE_P (dest_type) && POINTER_TYPE_P (src_type))
3618 || (FLOAT_TYPE_P (dest_type) && FLOAT_TYPE_P (src_type))
3619 || (TREE_CODE (dest_type) == OFFSET_TYPE
3620 && TREE_CODE (src_type) == OFFSET_TYPE))
3621 return initializer_constant_valid_p (src, endtype);
3623 /* Allow length-preserving conversions between integer types. */
3624 if (INTEGRAL_TYPE_P (dest_type) && INTEGRAL_TYPE_P (src_type)
3625 && (TYPE_PRECISION (dest_type) == TYPE_PRECISION (src_type)))
3626 return initializer_constant_valid_p (src, endtype);
3628 /* Allow conversions between other integer types only if
3629 explicit value. */
3630 if (INTEGRAL_TYPE_P (dest_type) && INTEGRAL_TYPE_P (src_type))
3632 tree inner = initializer_constant_valid_p (src, endtype);
3633 if (inner == null_pointer_node)
3634 return null_pointer_node;
3635 break;
3638 /* Allow (int) &foo provided int is as wide as a pointer. */
3639 if (INTEGRAL_TYPE_P (dest_type) && POINTER_TYPE_P (src_type)
3640 && (TYPE_PRECISION (dest_type) >= TYPE_PRECISION (src_type)))
3641 return initializer_constant_valid_p (src, endtype);
3643 /* Likewise conversions from int to pointers, but also allow
3644 conversions from 0. */
3645 if ((POINTER_TYPE_P (dest_type)
3646 || TREE_CODE (dest_type) == OFFSET_TYPE)
3647 && INTEGRAL_TYPE_P (src_type))
3649 if (integer_zerop (src))
3650 return null_pointer_node;
3651 else if (TYPE_PRECISION (dest_type) <= TYPE_PRECISION (src_type))
3652 return initializer_constant_valid_p (src, endtype);
3655 /* Allow conversions to struct or union types if the value
3656 inside is okay. */
3657 if (TREE_CODE (dest_type) == RECORD_TYPE
3658 || TREE_CODE (dest_type) == UNION_TYPE)
3659 return initializer_constant_valid_p (src, endtype);
3661 break;
3663 case PLUS_EXPR:
3664 if (! INTEGRAL_TYPE_P (endtype)
3665 || TYPE_PRECISION (endtype) >= POINTER_SIZE)
3667 tree valid0 = initializer_constant_valid_p (TREE_OPERAND (value, 0),
3668 endtype);
3669 tree valid1 = initializer_constant_valid_p (TREE_OPERAND (value, 1),
3670 endtype);
3671 /* If either term is absolute, use the other terms relocation. */
3672 if (valid0 == null_pointer_node)
3673 return valid1;
3674 if (valid1 == null_pointer_node)
3675 return valid0;
3677 break;
3679 case MINUS_EXPR:
3680 if (! INTEGRAL_TYPE_P (endtype)
3681 || TYPE_PRECISION (endtype) >= POINTER_SIZE)
3683 tree valid0 = initializer_constant_valid_p (TREE_OPERAND (value, 0),
3684 endtype);
3685 tree valid1 = initializer_constant_valid_p (TREE_OPERAND (value, 1),
3686 endtype);
3687 /* Win if second argument is absolute. */
3688 if (valid1 == null_pointer_node)
3689 return valid0;
3690 /* Win if both arguments have the same relocation.
3691 Then the value is absolute. */
3692 if (valid0 == valid1 && valid0 != 0)
3693 return null_pointer_node;
3695 /* Since GCC guarantees that string constants are unique in the
3696 generated code, a subtraction between two copies of the same
3697 constant string is absolute. */
3698 if (valid0 && TREE_CODE (valid0) == STRING_CST &&
3699 valid1 && TREE_CODE (valid1) == STRING_CST &&
3700 TREE_STRING_POINTER (valid0) == TREE_STRING_POINTER (valid1))
3701 return null_pointer_node;
3704 /* Support differences between labels. */
3705 if (INTEGRAL_TYPE_P (endtype))
3707 tree op0, op1;
3708 op0 = TREE_OPERAND (value, 0);
3709 op1 = TREE_OPERAND (value, 1);
3711 /* Like STRIP_NOPS except allow the operand mode to widen.
3712 This works around a feature of fold that simplifies
3713 (int)(p1 - p2) to ((int)p1 - (int)p2) under the theory
3714 that the narrower operation is cheaper. */
3716 while (TREE_CODE (op0) == NOP_EXPR
3717 || TREE_CODE (op0) == CONVERT_EXPR
3718 || TREE_CODE (op0) == NON_LVALUE_EXPR)
3720 tree inner = TREE_OPERAND (op0, 0);
3721 if (inner == error_mark_node
3722 || ! INTEGRAL_MODE_P (TYPE_MODE (TREE_TYPE (inner)))
3723 || (GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op0)))
3724 > GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (inner)))))
3725 break;
3726 op0 = inner;
3729 while (TREE_CODE (op1) == NOP_EXPR
3730 || TREE_CODE (op1) == CONVERT_EXPR
3731 || TREE_CODE (op1) == NON_LVALUE_EXPR)
3733 tree inner = TREE_OPERAND (op1, 0);
3734 if (inner == error_mark_node
3735 || ! INTEGRAL_MODE_P (TYPE_MODE (TREE_TYPE (inner)))
3736 || (GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op1)))
3737 > GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (inner)))))
3738 break;
3739 op1 = inner;
3742 if (TREE_CODE (op0) == ADDR_EXPR
3743 && TREE_CODE (TREE_OPERAND (op0, 0)) == LABEL_DECL
3744 && TREE_CODE (op1) == ADDR_EXPR
3745 && TREE_CODE (TREE_OPERAND (op1, 0)) == LABEL_DECL)
3746 return null_pointer_node;
3748 break;
3750 default:
3751 break;
3754 return 0;
3757 /* Output assembler code for constant EXP to FILE, with no label.
3758 This includes the pseudo-op such as ".int" or ".byte", and a newline.
3759 Assumes output_addressed_constants has been done on EXP already.
3761 Generate exactly SIZE bytes of assembler data, padding at the end
3762 with zeros if necessary. SIZE must always be specified.
3764 SIZE is important for structure constructors,
3765 since trailing members may have been omitted from the constructor.
3766 It is also important for initialization of arrays from string constants
3767 since the full length of the string constant might not be wanted.
3768 It is also needed for initialization of unions, where the initializer's
3769 type is just one member, and that may not be as long as the union.
3771 There a case in which we would fail to output exactly SIZE bytes:
3772 for a structure constructor that wants to produce more than SIZE bytes.
3773 But such constructors will never be generated for any possible input.
3775 ALIGN is the alignment of the data in bits. */
3777 void
3778 output_constant (tree exp, unsigned HOST_WIDE_INT size, unsigned int align)
3780 enum tree_code code;
3781 unsigned HOST_WIDE_INT thissize;
3783 /* Some front-ends use constants other than the standard language-independent
3784 varieties, but which may still be output directly. Give the front-end a
3785 chance to convert EXP to a language-independent representation. */
3786 exp = (*lang_hooks.expand_constant) (exp);
3788 if (size == 0 || flag_syntax_only)
3789 return;
3791 /* Eliminate any conversions since we'll be outputting the underlying
3792 constant. */
3793 while (TREE_CODE (exp) == NOP_EXPR || TREE_CODE (exp) == CONVERT_EXPR
3794 || TREE_CODE (exp) == NON_LVALUE_EXPR
3795 || TREE_CODE (exp) == VIEW_CONVERT_EXPR)
3796 exp = TREE_OPERAND (exp, 0);
3798 code = TREE_CODE (TREE_TYPE (exp));
3799 thissize = int_size_in_bytes (TREE_TYPE (exp));
3801 /* Allow a constructor with no elements for any data type.
3802 This means to fill the space with zeros. */
3803 if (TREE_CODE (exp) == CONSTRUCTOR && CONSTRUCTOR_ELTS (exp) == 0)
3805 assemble_zeros (size);
3806 return;
3809 if (TREE_CODE (exp) == FDESC_EXPR)
3811 #ifdef ASM_OUTPUT_FDESC
3812 HOST_WIDE_INT part = tree_low_cst (TREE_OPERAND (exp, 1), 0);
3813 tree decl = TREE_OPERAND (exp, 0);
3814 ASM_OUTPUT_FDESC (asm_out_file, decl, part);
3815 #else
3816 abort ();
3817 #endif
3818 return;
3821 /* Now output the underlying data. If we've handling the padding, return.
3822 Otherwise, break and ensure THISSIZE is the size written. */
3823 switch (code)
3825 case CHAR_TYPE:
3826 case BOOLEAN_TYPE:
3827 case INTEGER_TYPE:
3828 case ENUMERAL_TYPE:
3829 case POINTER_TYPE:
3830 case REFERENCE_TYPE:
3831 case OFFSET_TYPE:
3832 if (! assemble_integer (expand_expr (exp, NULL_RTX, VOIDmode,
3833 EXPAND_INITIALIZER),
3834 size, align, 0))
3835 error ("initializer for integer value is too complicated");
3836 break;
3838 case REAL_TYPE:
3839 if (TREE_CODE (exp) != REAL_CST)
3840 error ("initializer for floating value is not a floating constant");
3842 assemble_real (TREE_REAL_CST (exp), TYPE_MODE (TREE_TYPE (exp)), align);
3843 break;
3845 case COMPLEX_TYPE:
3846 output_constant (TREE_REALPART (exp), thissize / 2, align);
3847 output_constant (TREE_IMAGPART (exp), thissize / 2,
3848 min_align (align, BITS_PER_UNIT * (thissize / 2)));
3849 break;
3851 case ARRAY_TYPE:
3852 case VECTOR_TYPE:
3853 if (TREE_CODE (exp) == CONSTRUCTOR)
3855 output_constructor (exp, size, align);
3856 return;
3858 else if (TREE_CODE (exp) == STRING_CST)
3860 thissize = MIN ((unsigned HOST_WIDE_INT)TREE_STRING_LENGTH (exp),
3861 size);
3862 assemble_string (TREE_STRING_POINTER (exp), thissize);
3864 else if (TREE_CODE (exp) == VECTOR_CST)
3866 int elt_size;
3867 tree link;
3868 unsigned int nalign;
3869 enum machine_mode inner;
3871 inner = GET_MODE_INNER (TYPE_MODE (TREE_TYPE (exp)));
3872 nalign = MIN (align, GET_MODE_ALIGNMENT (inner));
3874 elt_size = GET_MODE_UNIT_SIZE (TYPE_MODE (TREE_TYPE (exp)));
3876 link = TREE_VECTOR_CST_ELTS (exp);
3877 output_constant (TREE_VALUE (link), elt_size, align);
3878 while ((link = TREE_CHAIN (link)) != NULL)
3879 output_constant (TREE_VALUE (link), elt_size, nalign);
3881 else
3882 abort ();
3883 break;
3885 case RECORD_TYPE:
3886 case UNION_TYPE:
3887 if (TREE_CODE (exp) == CONSTRUCTOR)
3888 output_constructor (exp, size, align);
3889 else
3890 abort ();
3891 return;
3893 case SET_TYPE:
3894 if (TREE_CODE (exp) == INTEGER_CST)
3895 assemble_integer (expand_expr (exp, NULL_RTX,
3896 VOIDmode, EXPAND_INITIALIZER),
3897 thissize, align, 1);
3898 else if (TREE_CODE (exp) == CONSTRUCTOR)
3900 unsigned char *buffer = alloca (thissize);
3901 if (get_set_constructor_bytes (exp, buffer, thissize))
3902 abort ();
3903 assemble_string ((char *) buffer, thissize);
3905 else
3906 error ("unknown set constructor type");
3907 return;
3909 case ERROR_MARK:
3910 return;
3912 default:
3913 abort ();
3916 if (size > thissize)
3917 assemble_zeros (size - thissize);
3921 /* Subroutine of output_constructor, used for computing the size of
3922 arrays of unspecified length. VAL must be a CONSTRUCTOR of an array
3923 type with an unspecified upper bound. */
3925 static unsigned HOST_WIDE_INT
3926 array_size_for_constructor (tree val)
3928 tree max_index, i;
3930 /* This code used to attempt to handle string constants that are not
3931 arrays of single-bytes, but nothing else does, so there's no point in
3932 doing it here. */
3933 if (TREE_CODE (val) == STRING_CST)
3934 return TREE_STRING_LENGTH (val);
3936 max_index = NULL_TREE;
3937 for (i = CONSTRUCTOR_ELTS (val); i; i = TREE_CHAIN (i))
3939 tree index = TREE_PURPOSE (i);
3941 if (TREE_CODE (index) == RANGE_EXPR)
3942 index = TREE_OPERAND (index, 1);
3943 if (max_index == NULL_TREE || tree_int_cst_lt (max_index, index))
3944 max_index = index;
3947 if (max_index == NULL_TREE)
3948 return 0;
3950 /* Compute the total number of array elements. */
3951 i = size_binop (MINUS_EXPR, convert (sizetype, max_index),
3952 convert (sizetype,
3953 TYPE_MIN_VALUE (TYPE_DOMAIN (TREE_TYPE (val)))));
3954 i = size_binop (PLUS_EXPR, i, convert (sizetype, integer_one_node));
3956 /* Multiply by the array element unit size to find number of bytes. */
3957 i = size_binop (MULT_EXPR, i, TYPE_SIZE_UNIT (TREE_TYPE (TREE_TYPE (val))));
3959 return tree_low_cst (i, 1);
3962 /* Subroutine of output_constant, used for CONSTRUCTORs (aggregate constants).
3963 Generate at least SIZE bytes, padding if necessary. */
3965 static void
3966 output_constructor (tree exp, unsigned HOST_WIDE_INT size,
3967 unsigned int align)
3969 tree type = TREE_TYPE (exp);
3970 tree link, field = 0;
3971 tree min_index = 0;
3972 /* Number of bytes output or skipped so far.
3973 In other words, current position within the constructor. */
3974 HOST_WIDE_INT total_bytes = 0;
3975 /* Nonzero means BYTE contains part of a byte, to be output. */
3976 int byte_buffer_in_use = 0;
3977 int byte = 0;
3979 if (HOST_BITS_PER_WIDE_INT < BITS_PER_UNIT)
3980 abort ();
3982 if (TREE_CODE (type) == RECORD_TYPE)
3983 field = TYPE_FIELDS (type);
3985 if (TREE_CODE (type) == ARRAY_TYPE
3986 && TYPE_DOMAIN (type) != 0)
3987 min_index = TYPE_MIN_VALUE (TYPE_DOMAIN (type));
3989 /* As LINK goes through the elements of the constant,
3990 FIELD goes through the structure fields, if the constant is a structure.
3991 if the constant is a union, then we override this,
3992 by getting the field from the TREE_LIST element.
3993 But the constant could also be an array. Then FIELD is zero.
3995 There is always a maximum of one element in the chain LINK for unions
3996 (even if the initializer in a source program incorrectly contains
3997 more one). */
3998 for (link = CONSTRUCTOR_ELTS (exp);
3999 link;
4000 link = TREE_CHAIN (link),
4001 field = field ? TREE_CHAIN (field) : 0)
4003 tree val = TREE_VALUE (link);
4004 tree index = 0;
4006 /* The element in a union constructor specifies the proper field
4007 or index. */
4008 if ((TREE_CODE (type) == RECORD_TYPE || TREE_CODE (type) == UNION_TYPE
4009 || TREE_CODE (type) == QUAL_UNION_TYPE)
4010 && TREE_PURPOSE (link) != 0)
4011 field = TREE_PURPOSE (link);
4013 else if (TREE_CODE (type) == ARRAY_TYPE)
4014 index = TREE_PURPOSE (link);
4016 #ifdef ASM_COMMENT_START
4017 if (field && flag_verbose_asm)
4018 fprintf (asm_out_file, "%s %s:\n",
4019 ASM_COMMENT_START,
4020 DECL_NAME (field)
4021 ? IDENTIFIER_POINTER (DECL_NAME (field))
4022 : "<anonymous>");
4023 #endif
4025 /* Eliminate the marker that makes a cast not be an lvalue. */
4026 if (val != 0)
4027 STRIP_NOPS (val);
4029 if (index && TREE_CODE (index) == RANGE_EXPR)
4031 unsigned HOST_WIDE_INT fieldsize
4032 = int_size_in_bytes (TREE_TYPE (type));
4033 HOST_WIDE_INT lo_index = tree_low_cst (TREE_OPERAND (index, 0), 0);
4034 HOST_WIDE_INT hi_index = tree_low_cst (TREE_OPERAND (index, 1), 0);
4035 HOST_WIDE_INT index;
4036 unsigned int align2 = min_align (align, fieldsize * BITS_PER_UNIT);
4038 for (index = lo_index; index <= hi_index; index++)
4040 /* Output the element's initial value. */
4041 if (val == 0)
4042 assemble_zeros (fieldsize);
4043 else
4044 output_constant (val, fieldsize, align2);
4046 /* Count its size. */
4047 total_bytes += fieldsize;
4050 else if (field == 0 || !DECL_BIT_FIELD (field))
4052 /* An element that is not a bit-field. */
4054 unsigned HOST_WIDE_INT fieldsize;
4055 /* Since this structure is static,
4056 we know the positions are constant. */
4057 HOST_WIDE_INT pos = field ? int_byte_position (field) : 0;
4058 unsigned int align2;
4060 if (index != 0)
4061 pos = (tree_low_cst (TYPE_SIZE_UNIT (TREE_TYPE (val)), 1)
4062 * (tree_low_cst (index, 0) - tree_low_cst (min_index, 0)));
4064 /* Output any buffered-up bit-fields preceding this element. */
4065 if (byte_buffer_in_use)
4067 assemble_integer (GEN_INT (byte), 1, BITS_PER_UNIT, 1);
4068 total_bytes++;
4069 byte_buffer_in_use = 0;
4072 /* Advance to offset of this element.
4073 Note no alignment needed in an array, since that is guaranteed
4074 if each element has the proper size. */
4075 if ((field != 0 || index != 0) && pos != total_bytes)
4077 assemble_zeros (pos - total_bytes);
4078 total_bytes = pos;
4081 /* Find the alignment of this element. */
4082 align2 = min_align (align, BITS_PER_UNIT * pos);
4084 /* Determine size this element should occupy. */
4085 if (field)
4087 fieldsize = 0;
4089 /* If this is an array with an unspecified upper bound,
4090 the initializer determines the size. */
4091 /* ??? This ought to only checked if DECL_SIZE_UNIT is NULL,
4092 but we cannot do this until the deprecated support for
4093 initializing zero-length array members is removed. */
4094 if (TREE_CODE (TREE_TYPE (field)) == ARRAY_TYPE
4095 && TYPE_DOMAIN (TREE_TYPE (field))
4096 && ! TYPE_MAX_VALUE (TYPE_DOMAIN (TREE_TYPE (field))))
4098 fieldsize = array_size_for_constructor (val);
4099 /* Given a non-empty initialization, this field had
4100 better be last. */
4101 if (fieldsize != 0 && TREE_CHAIN (field) != NULL_TREE)
4102 abort ();
4104 else if (DECL_SIZE_UNIT (field))
4106 /* ??? This can't be right. If the decl size overflows
4107 a host integer we will silently emit no data. */
4108 if (host_integerp (DECL_SIZE_UNIT (field), 1))
4109 fieldsize = tree_low_cst (DECL_SIZE_UNIT (field), 1);
4112 else
4113 fieldsize = int_size_in_bytes (TREE_TYPE (type));
4115 /* Output the element's initial value. */
4116 if (val == 0)
4117 assemble_zeros (fieldsize);
4118 else
4119 output_constant (val, fieldsize, align2);
4121 /* Count its size. */
4122 total_bytes += fieldsize;
4124 else if (val != 0 && TREE_CODE (val) != INTEGER_CST)
4125 error ("invalid initial value for member `%s'",
4126 IDENTIFIER_POINTER (DECL_NAME (field)));
4127 else
4129 /* Element that is a bit-field. */
4131 HOST_WIDE_INT next_offset = int_bit_position (field);
4132 HOST_WIDE_INT end_offset
4133 = (next_offset + tree_low_cst (DECL_SIZE (field), 1));
4135 if (val == 0)
4136 val = integer_zero_node;
4138 /* If this field does not start in this (or, next) byte,
4139 skip some bytes. */
4140 if (next_offset / BITS_PER_UNIT != total_bytes)
4142 /* Output remnant of any bit field in previous bytes. */
4143 if (byte_buffer_in_use)
4145 assemble_integer (GEN_INT (byte), 1, BITS_PER_UNIT, 1);
4146 total_bytes++;
4147 byte_buffer_in_use = 0;
4150 /* If still not at proper byte, advance to there. */
4151 if (next_offset / BITS_PER_UNIT != total_bytes)
4153 assemble_zeros (next_offset / BITS_PER_UNIT - total_bytes);
4154 total_bytes = next_offset / BITS_PER_UNIT;
4158 if (! byte_buffer_in_use)
4159 byte = 0;
4161 /* We must split the element into pieces that fall within
4162 separate bytes, and combine each byte with previous or
4163 following bit-fields. */
4165 /* next_offset is the offset n fbits from the beginning of
4166 the structure to the next bit of this element to be processed.
4167 end_offset is the offset of the first bit past the end of
4168 this element. */
4169 while (next_offset < end_offset)
4171 int this_time;
4172 int shift;
4173 HOST_WIDE_INT value;
4174 HOST_WIDE_INT next_byte = next_offset / BITS_PER_UNIT;
4175 HOST_WIDE_INT next_bit = next_offset % BITS_PER_UNIT;
4177 /* Advance from byte to byte
4178 within this element when necessary. */
4179 while (next_byte != total_bytes)
4181 assemble_integer (GEN_INT (byte), 1, BITS_PER_UNIT, 1);
4182 total_bytes++;
4183 byte = 0;
4186 /* Number of bits we can process at once
4187 (all part of the same byte). */
4188 this_time = MIN (end_offset - next_offset,
4189 BITS_PER_UNIT - next_bit);
4190 if (BYTES_BIG_ENDIAN)
4192 /* On big-endian machine, take the most significant bits
4193 first (of the bits that are significant)
4194 and put them into bytes from the most significant end. */
4195 shift = end_offset - next_offset - this_time;
4197 /* Don't try to take a bunch of bits that cross
4198 the word boundary in the INTEGER_CST. We can
4199 only select bits from the LOW or HIGH part
4200 not from both. */
4201 if (shift < HOST_BITS_PER_WIDE_INT
4202 && shift + this_time > HOST_BITS_PER_WIDE_INT)
4204 this_time = shift + this_time - HOST_BITS_PER_WIDE_INT;
4205 shift = HOST_BITS_PER_WIDE_INT;
4208 /* Now get the bits from the appropriate constant word. */
4209 if (shift < HOST_BITS_PER_WIDE_INT)
4210 value = TREE_INT_CST_LOW (val);
4211 else if (shift < 2 * HOST_BITS_PER_WIDE_INT)
4213 value = TREE_INT_CST_HIGH (val);
4214 shift -= HOST_BITS_PER_WIDE_INT;
4216 else
4217 abort ();
4219 /* Get the result. This works only when:
4220 1 <= this_time <= HOST_BITS_PER_WIDE_INT. */
4221 byte |= (((value >> shift)
4222 & (((HOST_WIDE_INT) 2 << (this_time - 1)) - 1))
4223 << (BITS_PER_UNIT - this_time - next_bit));
4225 else
4227 /* On little-endian machines,
4228 take first the least significant bits of the value
4229 and pack them starting at the least significant
4230 bits of the bytes. */
4231 shift = next_offset - int_bit_position (field);
4233 /* Don't try to take a bunch of bits that cross
4234 the word boundary in the INTEGER_CST. We can
4235 only select bits from the LOW or HIGH part
4236 not from both. */
4237 if (shift < HOST_BITS_PER_WIDE_INT
4238 && shift + this_time > HOST_BITS_PER_WIDE_INT)
4239 this_time = (HOST_BITS_PER_WIDE_INT - shift);
4241 /* Now get the bits from the appropriate constant word. */
4242 if (shift < HOST_BITS_PER_WIDE_INT)
4243 value = TREE_INT_CST_LOW (val);
4244 else if (shift < 2 * HOST_BITS_PER_WIDE_INT)
4246 value = TREE_INT_CST_HIGH (val);
4247 shift -= HOST_BITS_PER_WIDE_INT;
4249 else
4250 abort ();
4252 /* Get the result. This works only when:
4253 1 <= this_time <= HOST_BITS_PER_WIDE_INT. */
4254 byte |= (((value >> shift)
4255 & (((HOST_WIDE_INT) 2 << (this_time - 1)) - 1))
4256 << next_bit);
4259 next_offset += this_time;
4260 byte_buffer_in_use = 1;
4265 if (byte_buffer_in_use)
4267 assemble_integer (GEN_INT (byte), 1, BITS_PER_UNIT, 1);
4268 total_bytes++;
4271 if ((unsigned HOST_WIDE_INT)total_bytes < size)
4272 assemble_zeros (size - total_bytes);
4275 /* This TREE_LIST contains any weak symbol declarations waiting
4276 to be emitted. */
4277 static GTY(()) tree weak_decls;
4279 /* Mark DECL as weak. */
4281 static void
4282 mark_weak (tree decl)
4284 DECL_WEAK (decl) = 1;
4286 if (DECL_RTL_SET_P (decl)
4287 && GET_CODE (DECL_RTL (decl)) == MEM
4288 && XEXP (DECL_RTL (decl), 0)
4289 && GET_CODE (XEXP (DECL_RTL (decl), 0)) == SYMBOL_REF)
4290 SYMBOL_REF_WEAK (XEXP (DECL_RTL (decl), 0)) = 1;
4293 /* Merge weak status between NEWDECL and OLDDECL. */
4295 void
4296 merge_weak (tree newdecl, tree olddecl)
4298 if (DECL_WEAK (newdecl) == DECL_WEAK (olddecl))
4299 return;
4301 if (DECL_WEAK (newdecl))
4303 tree wd;
4305 /* NEWDECL is weak, but OLDDECL is not. */
4307 /* If we already output the OLDDECL, we're in trouble; we can't
4308 go back and make it weak. This error cannot caught in
4309 declare_weak because the NEWDECL and OLDDECL was not yet
4310 been merged; therefore, TREE_ASM_WRITTEN was not set. */
4311 if (TREE_ASM_WRITTEN (olddecl))
4312 error ("%Jweak declaration of '%D' must precede definition",
4313 newdecl, newdecl);
4315 /* If we've already generated rtl referencing OLDDECL, we may
4316 have done so in a way that will not function properly with
4317 a weak symbol. */
4318 else if (TREE_USED (olddecl)
4319 && TREE_SYMBOL_REFERENCED (DECL_ASSEMBLER_NAME (olddecl)))
4320 warning ("%Jweak declaration of '%D' after first use results "
4321 "in unspecified behavior", newdecl, newdecl);
4323 if (SUPPORTS_WEAK)
4325 /* We put the NEWDECL on the weak_decls list at some point.
4326 Replace it with the OLDDECL. */
4327 for (wd = weak_decls; wd; wd = TREE_CHAIN (wd))
4328 if (TREE_VALUE (wd) == newdecl)
4330 TREE_VALUE (wd) = olddecl;
4331 break;
4333 /* We may not find the entry on the list. If NEWDECL is a
4334 weak alias, then we will have already called
4335 globalize_decl to remove the entry; in that case, we do
4336 not need to do anything. */
4339 /* Make the OLDDECL weak; it's OLDDECL that we'll be keeping. */
4340 mark_weak (olddecl);
4342 else
4343 /* OLDDECL was weak, but NEWDECL was not explicitly marked as
4344 weak. Just update NEWDECL to indicate that it's weak too. */
4345 mark_weak (newdecl);
4348 /* Declare DECL to be a weak symbol. */
4350 void
4351 declare_weak (tree decl)
4353 if (! TREE_PUBLIC (decl))
4354 error ("%Jweak declaration of '%D' must be public", decl, decl);
4355 else if (TREE_CODE (decl) == FUNCTION_DECL && TREE_ASM_WRITTEN (decl))
4356 error ("%Jweak declaration of '%D' must precede definition", decl, decl);
4357 else if (SUPPORTS_WEAK)
4359 if (! DECL_WEAK (decl))
4360 weak_decls = tree_cons (NULL, decl, weak_decls);
4362 else
4363 warning ("%Jweak declaration of '%D' not supported", decl, decl);
4365 mark_weak (decl);
4368 /* Emit any pending weak declarations. */
4370 void
4371 weak_finish (void)
4373 tree t;
4375 for (t = weak_decls; t; t = TREE_CHAIN (t))
4377 tree decl = TREE_VALUE (t);
4378 #if defined (ASM_WEAKEN_DECL) || defined (ASM_WEAKEN_LABEL)
4379 const char *const name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
4380 #endif
4382 if (! TREE_USED (decl))
4383 continue;
4385 #ifdef ASM_WEAKEN_DECL
4386 ASM_WEAKEN_DECL (asm_out_file, decl, name, NULL);
4387 #else
4388 #ifdef ASM_WEAKEN_LABEL
4389 ASM_WEAKEN_LABEL (asm_out_file, name);
4390 #else
4391 #ifdef ASM_OUTPUT_WEAK_ALIAS
4392 warning ("only weak aliases are supported in this configuration");
4393 return;
4394 #endif
4395 #endif
4396 #endif
4400 /* Emit the assembly bits to indicate that DECL is globally visible. */
4402 static void
4403 globalize_decl (tree decl)
4405 const char *name = XSTR (XEXP (DECL_RTL (decl), 0), 0);
4407 #if defined (ASM_WEAKEN_LABEL) || defined (ASM_WEAKEN_DECL)
4408 if (DECL_WEAK (decl))
4410 tree *p, t;
4412 #ifdef ASM_WEAKEN_DECL
4413 ASM_WEAKEN_DECL (asm_out_file, decl, name, 0);
4414 #else
4415 ASM_WEAKEN_LABEL (asm_out_file, name);
4416 #endif
4418 /* Remove this function from the pending weak list so that
4419 we do not emit multiple .weak directives for it. */
4420 for (p = &weak_decls; (t = *p) ; )
4422 if (DECL_ASSEMBLER_NAME (decl) == DECL_ASSEMBLER_NAME (TREE_VALUE (t)))
4423 *p = TREE_CHAIN (t);
4424 else
4425 p = &TREE_CHAIN (t);
4427 return;
4429 #endif
4431 (*targetm.asm_out.globalize_label) (asm_out_file, name);
4434 /* Some targets do not allow a forward or undefined reference in a
4435 ASM_OUTPUT_DEF. Thus, a mechanism is needed to defer the output
4436 of this assembler code. The output_def_pair struct holds the
4437 declaration and target for a deferred output define. */
4438 struct output_def_pair GTY(())
4440 tree decl;
4441 tree target;
4443 typedef struct output_def_pair *output_def_pair;
4445 /* Variable array of deferred output defines. */
4446 static GTY ((param_is (struct output_def_pair))) varray_type output_defs;
4448 #ifdef ASM_OUTPUT_DEF
4449 /* Output the assembler code for a define (equate) using ASM_OUTPUT_DEF
4450 or ASM_OUTPUT_DEF_FROM_DECLS. The function defines the symbol whose
4451 tree node is DECL to have the value of the tree node TARGET. */
4453 static void
4454 assemble_output_def (tree decl ATTRIBUTE_UNUSED, tree target ATTRIBUTE_UNUSED)
4456 #ifdef ASM_OUTPUT_DEF_FROM_DECLS
4457 ASM_OUTPUT_DEF_FROM_DECLS (asm_out_file, decl, target);
4458 #else
4459 ASM_OUTPUT_DEF (asm_out_file,
4460 IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl)),
4461 IDENTIFIER_POINTER (target));
4462 #endif
4464 #endif
4466 /* Process the varray of pending assembler defines. */
4468 void
4469 process_pending_assemble_output_defs (void)
4471 #ifdef ASM_OUTPUT_DEF
4472 size_t i;
4473 output_def_pair p;
4475 if (!output_defs)
4476 return;
4478 for (i = 0; i < VARRAY_ACTIVE_SIZE (output_defs); i++)
4480 p = VARRAY_GENERIC_PTR (output_defs, i);
4481 assemble_output_def (p->decl, p->target);
4484 output_defs = NULL;
4485 #endif
4488 /* Emit an assembler directive to make the symbol for DECL an alias to
4489 the symbol for TARGET. */
4491 void
4492 assemble_alias (tree decl, tree target ATTRIBUTE_UNUSED)
4494 /* We must force creation of DECL_RTL for debug info generation, even though
4495 we don't use it here. */
4496 make_decl_rtl (decl, NULL);
4498 #ifdef ASM_OUTPUT_DEF
4499 /* Make name accessible from other files, if appropriate. */
4501 if (TREE_PUBLIC (decl))
4503 globalize_decl (decl);
4504 maybe_assemble_visibility (decl);
4507 if (TARGET_DEFERRED_OUTPUT_DEFS (decl, target))
4509 output_def_pair p;
4511 if (!output_defs)
4512 VARRAY_GENERIC_PTR_INIT (output_defs, 10, "output defs");
4514 p = ggc_alloc (sizeof (struct output_def_pair));
4515 p->decl = decl;
4516 p->target = target;
4517 VARRAY_PUSH_GENERIC_PTR (output_defs, p);
4519 else
4520 assemble_output_def (decl, target);
4521 #else /* !ASM_OUTPUT_DEF */
4522 #if defined (ASM_OUTPUT_WEAK_ALIAS) || defined (ASM_WEAKEN_DECL)
4523 if (DECL_WEAK (decl))
4525 const char *name;
4526 tree *p, t;
4528 name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
4529 #ifdef ASM_WEAKEN_DECL
4530 ASM_WEAKEN_DECL (asm_out_file, decl, name, IDENTIFIER_POINTER (target));
4531 #else
4532 ASM_OUTPUT_WEAK_ALIAS (asm_out_file, name, IDENTIFIER_POINTER (target));
4533 #endif
4534 /* Remove this function from the pending weak list so that
4535 we do not emit multiple .weak directives for it. */
4536 for (p = &weak_decls; (t = *p) ; )
4537 if (DECL_ASSEMBLER_NAME (decl)
4538 == DECL_ASSEMBLER_NAME (TREE_VALUE (t)))
4539 *p = TREE_CHAIN (t);
4540 else
4541 p = &TREE_CHAIN (t);
4543 else
4544 warning ("only weak aliases are supported in this configuration");
4546 #else
4547 warning ("alias definitions not supported in this configuration; ignored");
4548 #endif
4549 #endif
4551 TREE_USED (decl) = 1;
4552 TREE_ASM_WRITTEN (decl) = 1;
4553 TREE_ASM_WRITTEN (DECL_ASSEMBLER_NAME (decl)) = 1;
4556 /* Emit an assembler directive to set symbol for DECL visibility to
4557 the visibility type VIS, which must not be VISIBILITY_DEFAULT. */
4559 void
4560 default_assemble_visibility (tree decl, int vis)
4562 static const char * const visibility_types[] = {
4563 NULL, "internal", "hidden", "protected"
4566 const char *name, *type;
4568 name = (IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl)));
4569 type = visibility_types[vis];
4571 #ifdef HAVE_GAS_HIDDEN
4572 fprintf (asm_out_file, "\t.%s\t", type);
4573 assemble_name (asm_out_file, name);
4574 fprintf (asm_out_file, "\n");
4575 #else
4576 warning ("visibility attribute not supported in this configuration; ignored");
4577 #endif
4580 /* A helper function to call assemble_visibility when needed for a decl. */
4582 static void
4583 maybe_assemble_visibility (tree decl)
4585 enum symbol_visibility vis = DECL_VISIBILITY (decl);
4587 if (vis != VISIBILITY_DEFAULT)
4588 (* targetm.asm_out.visibility) (decl, vis);
4591 /* Returns 1 if the target configuration supports defining public symbols
4592 so that one of them will be chosen at link time instead of generating a
4593 multiply-defined symbol error, whether through the use of weak symbols or
4594 a target-specific mechanism for having duplicates discarded. */
4597 supports_one_only (void)
4599 if (SUPPORTS_ONE_ONLY)
4600 return 1;
4601 return SUPPORTS_WEAK;
4604 /* Set up DECL as a public symbol that can be defined in multiple
4605 translation units without generating a linker error. */
4607 void
4608 make_decl_one_only (tree decl)
4610 if (TREE_CODE (decl) != VAR_DECL && TREE_CODE (decl) != FUNCTION_DECL)
4611 abort ();
4613 TREE_PUBLIC (decl) = 1;
4615 if (SUPPORTS_ONE_ONLY)
4617 #ifdef MAKE_DECL_ONE_ONLY
4618 MAKE_DECL_ONE_ONLY (decl);
4619 #endif
4620 DECL_ONE_ONLY (decl) = 1;
4622 else if (TREE_CODE (decl) == VAR_DECL
4623 && (DECL_INITIAL (decl) == 0 || DECL_INITIAL (decl) == error_mark_node))
4624 DECL_COMMON (decl) = 1;
4625 else if (SUPPORTS_WEAK)
4626 DECL_WEAK (decl) = 1;
4627 else
4628 abort ();
4631 void
4632 init_varasm_once (void)
4634 in_named_htab = htab_create_ggc (31, in_named_entry_hash,
4635 in_named_entry_eq, NULL);
4636 const_desc_htab = htab_create_ggc (1009, const_desc_hash,
4637 const_desc_eq, NULL);
4639 const_alias_set = new_alias_set ();
4642 enum tls_model
4643 decl_tls_model (tree decl)
4645 enum tls_model kind;
4646 tree attr = lookup_attribute ("tls_model", DECL_ATTRIBUTES (decl));
4647 bool is_local;
4649 if (attr)
4651 attr = TREE_VALUE (TREE_VALUE (attr));
4652 if (TREE_CODE (attr) != STRING_CST)
4653 abort ();
4654 if (!strcmp (TREE_STRING_POINTER (attr), "local-exec"))
4655 kind = TLS_MODEL_LOCAL_EXEC;
4656 else if (!strcmp (TREE_STRING_POINTER (attr), "initial-exec"))
4657 kind = TLS_MODEL_INITIAL_EXEC;
4658 else if (!strcmp (TREE_STRING_POINTER (attr), "local-dynamic"))
4659 kind = optimize ? TLS_MODEL_LOCAL_DYNAMIC : TLS_MODEL_GLOBAL_DYNAMIC;
4660 else if (!strcmp (TREE_STRING_POINTER (attr), "global-dynamic"))
4661 kind = TLS_MODEL_GLOBAL_DYNAMIC;
4662 else
4663 abort ();
4664 return kind;
4667 is_local = (*targetm.binds_local_p) (decl);
4668 if (!flag_pic)
4670 if (is_local)
4671 kind = TLS_MODEL_LOCAL_EXEC;
4672 else
4673 kind = TLS_MODEL_INITIAL_EXEC;
4675 /* Local dynamic is inefficient when we're not combining the
4676 parts of the address. */
4677 else if (optimize && is_local)
4678 kind = TLS_MODEL_LOCAL_DYNAMIC;
4679 else
4680 kind = TLS_MODEL_GLOBAL_DYNAMIC;
4681 if (kind < flag_tls_default)
4682 kind = flag_tls_default;
4684 return kind;
4687 /* Select a set of attributes for section NAME based on the properties
4688 of DECL and whether or not RELOC indicates that DECL's initializer
4689 might contain runtime relocations.
4691 We make the section read-only and executable for a function decl,
4692 read-only for a const data decl, and writable for a non-const data decl. */
4694 unsigned int
4695 default_section_type_flags (tree decl, const char *name, int reloc)
4697 return default_section_type_flags_1 (decl, name, reloc, flag_pic);
4700 unsigned int
4701 default_section_type_flags_1 (tree decl, const char *name, int reloc,
4702 int shlib)
4704 unsigned int flags;
4706 if (decl && TREE_CODE (decl) == FUNCTION_DECL)
4707 flags = SECTION_CODE;
4708 else if (decl && decl_readonly_section_1 (decl, reloc, shlib))
4709 flags = 0;
4710 else
4711 flags = SECTION_WRITE;
4713 if (decl && DECL_ONE_ONLY (decl))
4714 flags |= SECTION_LINKONCE;
4716 if (decl && TREE_CODE (decl) == VAR_DECL && DECL_THREAD_LOCAL (decl))
4717 flags |= SECTION_TLS | SECTION_WRITE;
4719 if (strcmp (name, ".bss") == 0
4720 || strncmp (name, ".bss.", 5) == 0
4721 || strncmp (name, ".gnu.linkonce.b.", 16) == 0
4722 || strcmp (name, ".sbss") == 0
4723 || strncmp (name, ".sbss.", 6) == 0
4724 || strncmp (name, ".gnu.linkonce.sb.", 17) == 0
4725 || strcmp (name, ".tbss") == 0
4726 || strncmp (name, ".gnu.linkonce.tb.", 17) == 0)
4727 flags |= SECTION_BSS;
4729 if (strcmp (name, ".tdata") == 0
4730 || strcmp (name, ".tbss") == 0
4731 || strncmp (name, ".gnu.linkonce.td.", 17) == 0
4732 || strncmp (name, ".gnu.linkonce.tb.", 17) == 0)
4733 flags |= SECTION_TLS;
4735 /* These three sections have special ELF types. They are neither
4736 SHT_PROGBITS nor SHT_NOBITS, so when changing sections we don't
4737 want to print a section type (@progbits or @nobits). If someone
4738 is silly enough to emit code or TLS variables to one of these
4739 sections, then don't handle them specially. */
4740 if (!(flags & (SECTION_CODE | SECTION_BSS | SECTION_TLS))
4741 && (strcmp (name, ".init_array") == 0
4742 || strcmp (name, ".fini_array") == 0
4743 || strcmp (name, ".preinit_array") == 0))
4744 flags |= SECTION_NOTYPE;
4746 return flags;
4749 /* Output assembly to switch to section NAME with attribute FLAGS.
4750 Four variants for common object file formats. */
4752 void
4753 default_no_named_section (const char *name ATTRIBUTE_UNUSED,
4754 unsigned int flags ATTRIBUTE_UNUSED)
4756 /* Some object formats don't support named sections at all. The
4757 front-end should already have flagged this as an error. */
4758 abort ();
4761 void
4762 default_elf_asm_named_section (const char *name, unsigned int flags)
4764 char flagchars[10], *f = flagchars;
4766 if (! named_section_first_declaration (name))
4768 fprintf (asm_out_file, "\t.section\t%s\n", name);
4769 return;
4772 if (!(flags & SECTION_DEBUG))
4773 *f++ = 'a';
4774 if (flags & SECTION_WRITE)
4775 *f++ = 'w';
4776 if (flags & SECTION_CODE)
4777 *f++ = 'x';
4778 if (flags & SECTION_SMALL)
4779 *f++ = 's';
4780 if (flags & SECTION_MERGE)
4781 *f++ = 'M';
4782 if (flags & SECTION_STRINGS)
4783 *f++ = 'S';
4784 if (flags & SECTION_TLS)
4785 *f++ = 'T';
4786 *f = '\0';
4788 fprintf (asm_out_file, "\t.section\t%s,\"%s\"", name, flagchars);
4790 if (!(flags & SECTION_NOTYPE))
4792 const char *type;
4794 if (flags & SECTION_BSS)
4795 type = "nobits";
4796 else
4797 type = "progbits";
4799 fprintf (asm_out_file, ",@%s", type);
4801 if (flags & SECTION_ENTSIZE)
4802 fprintf (asm_out_file, ",%d", flags & SECTION_ENTSIZE);
4805 putc ('\n', asm_out_file);
4808 void
4809 default_coff_asm_named_section (const char *name, unsigned int flags)
4811 char flagchars[8], *f = flagchars;
4813 if (flags & SECTION_WRITE)
4814 *f++ = 'w';
4815 if (flags & SECTION_CODE)
4816 *f++ = 'x';
4817 *f = '\0';
4819 fprintf (asm_out_file, "\t.section\t%s,\"%s\"\n", name, flagchars);
4822 void
4823 default_pe_asm_named_section (const char *name, unsigned int flags)
4825 default_coff_asm_named_section (name, flags);
4827 if (flags & SECTION_LINKONCE)
4829 /* Functions may have been compiled at various levels of
4830 optimization so we can't use `same_size' here.
4831 Instead, have the linker pick one. */
4832 fprintf (asm_out_file, "\t.linkonce %s\n",
4833 (flags & SECTION_CODE ? "discard" : "same_size"));
4837 /* The lame default section selector. */
4839 void
4840 default_select_section (tree decl, int reloc,
4841 unsigned HOST_WIDE_INT align ATTRIBUTE_UNUSED)
4843 bool readonly = false;
4845 if (DECL_P (decl))
4847 if (decl_readonly_section (decl, reloc))
4848 readonly = true;
4850 else if (TREE_CODE (decl) == CONSTRUCTOR)
4852 if (! ((flag_pic && reloc)
4853 || !TREE_READONLY (decl)
4854 || TREE_SIDE_EFFECTS (decl)
4855 || !TREE_CONSTANT (decl)))
4856 readonly = true;
4858 else if (TREE_CODE (decl) == STRING_CST)
4859 readonly = !flag_writable_strings;
4860 else if (! (flag_pic && reloc))
4861 readonly = true;
4863 if (readonly)
4864 readonly_data_section ();
4865 else
4866 data_section ();
4869 /* A helper function for default_elf_select_section and
4870 default_elf_unique_section. Categorizes the DECL. */
4872 enum section_category
4874 SECCAT_TEXT,
4876 SECCAT_RODATA,
4877 SECCAT_RODATA_MERGE_STR,
4878 SECCAT_RODATA_MERGE_STR_INIT,
4879 SECCAT_RODATA_MERGE_CONST,
4880 SECCAT_SRODATA,
4882 SECCAT_DATA,
4884 /* To optimize loading of shared programs, define following subsections
4885 of data section:
4886 _REL Contains data that has relocations, so they get grouped
4887 together and dynamic linker will visit fewer pages in memory.
4888 _RO Contains data that is otherwise read-only. This is useful
4889 with prelinking as most relocations won't be dynamically
4890 linked and thus stay read only.
4891 _LOCAL Marks data containing relocations only to local objects.
4892 These relocations will get fully resolved by prelinking. */
4893 SECCAT_DATA_REL,
4894 SECCAT_DATA_REL_LOCAL,
4895 SECCAT_DATA_REL_RO,
4896 SECCAT_DATA_REL_RO_LOCAL,
4898 SECCAT_SDATA,
4899 SECCAT_TDATA,
4901 SECCAT_BSS,
4902 SECCAT_SBSS,
4903 SECCAT_TBSS
4906 static enum section_category
4907 categorize_decl_for_section (tree, int, int);
4909 static enum section_category
4910 categorize_decl_for_section (tree decl, int reloc, int shlib)
4912 enum section_category ret;
4914 if (TREE_CODE (decl) == FUNCTION_DECL)
4915 return SECCAT_TEXT;
4916 else if (TREE_CODE (decl) == STRING_CST)
4918 if (flag_writable_strings)
4919 return SECCAT_DATA;
4920 else
4921 return SECCAT_RODATA_MERGE_STR;
4923 else if (TREE_CODE (decl) == VAR_DECL)
4925 if (DECL_INITIAL (decl) == NULL
4926 || DECL_INITIAL (decl) == error_mark_node)
4927 ret = SECCAT_BSS;
4928 else if (! TREE_READONLY (decl)
4929 || TREE_SIDE_EFFECTS (decl)
4930 || ! TREE_CONSTANT (DECL_INITIAL (decl)))
4932 if (shlib && (reloc & 2))
4933 ret = SECCAT_DATA_REL;
4934 else if (shlib && reloc)
4935 ret = SECCAT_DATA_REL_LOCAL;
4936 else
4937 ret = SECCAT_DATA;
4939 else if (shlib && (reloc & 2))
4940 ret = SECCAT_DATA_REL_RO;
4941 else if (shlib && reloc)
4942 ret = SECCAT_DATA_REL_RO_LOCAL;
4943 else if (reloc || flag_merge_constants < 2)
4944 /* C and C++ don't allow different variables to share the same
4945 location. -fmerge-all-constants allows even that (at the
4946 expense of not conforming). */
4947 ret = SECCAT_RODATA;
4948 else if (TREE_CODE (DECL_INITIAL (decl)) == STRING_CST)
4949 ret = SECCAT_RODATA_MERGE_STR_INIT;
4950 else
4951 ret = SECCAT_RODATA_MERGE_CONST;
4953 else if (TREE_CODE (decl) == CONSTRUCTOR)
4955 if ((shlib && reloc)
4956 || TREE_SIDE_EFFECTS (decl)
4957 || ! TREE_CONSTANT (decl))
4958 ret = SECCAT_DATA;
4959 else
4960 ret = SECCAT_RODATA;
4962 else
4963 ret = SECCAT_RODATA;
4965 /* There are no read-only thread-local sections. */
4966 if (TREE_CODE (decl) == VAR_DECL && DECL_THREAD_LOCAL (decl))
4968 if (ret == SECCAT_BSS)
4969 ret = SECCAT_TBSS;
4970 else
4971 ret = SECCAT_TDATA;
4974 /* If the target uses small data sections, select it. */
4975 else if ((*targetm.in_small_data_p) (decl))
4977 if (ret == SECCAT_BSS)
4978 ret = SECCAT_SBSS;
4979 else if (targetm.have_srodata_section && ret == SECCAT_RODATA)
4980 ret = SECCAT_SRODATA;
4981 else
4982 ret = SECCAT_SDATA;
4985 return ret;
4988 bool
4989 decl_readonly_section (tree decl, int reloc)
4991 return decl_readonly_section_1 (decl, reloc, flag_pic);
4994 bool
4995 decl_readonly_section_1 (tree decl, int reloc, int shlib)
4997 switch (categorize_decl_for_section (decl, reloc, shlib))
4999 case SECCAT_RODATA:
5000 case SECCAT_RODATA_MERGE_STR:
5001 case SECCAT_RODATA_MERGE_STR_INIT:
5002 case SECCAT_RODATA_MERGE_CONST:
5003 case SECCAT_SRODATA:
5004 return true;
5005 break;
5006 default:
5007 return false;
5008 break;
5012 /* Select a section based on the above categorization. */
5014 void
5015 default_elf_select_section (tree decl, int reloc,
5016 unsigned HOST_WIDE_INT align)
5018 default_elf_select_section_1 (decl, reloc, align, flag_pic);
5021 void
5022 default_elf_select_section_1 (tree decl, int reloc,
5023 unsigned HOST_WIDE_INT align, int shlib)
5025 switch (categorize_decl_for_section (decl, reloc, shlib))
5027 case SECCAT_TEXT:
5028 /* We're not supposed to be called on FUNCTION_DECLs. */
5029 abort ();
5030 case SECCAT_RODATA:
5031 readonly_data_section ();
5032 break;
5033 case SECCAT_RODATA_MERGE_STR:
5034 mergeable_string_section (decl, align, 0);
5035 break;
5036 case SECCAT_RODATA_MERGE_STR_INIT:
5037 mergeable_string_section (DECL_INITIAL (decl), align, 0);
5038 break;
5039 case SECCAT_RODATA_MERGE_CONST:
5040 mergeable_constant_section (DECL_MODE (decl), align, 0);
5041 break;
5042 case SECCAT_SRODATA:
5043 named_section (NULL_TREE, ".sdata2", reloc);
5044 break;
5045 case SECCAT_DATA:
5046 data_section ();
5047 break;
5048 case SECCAT_DATA_REL:
5049 named_section (NULL_TREE, ".data.rel", reloc);
5050 break;
5051 case SECCAT_DATA_REL_LOCAL:
5052 named_section (NULL_TREE, ".data.rel.local", reloc);
5053 break;
5054 case SECCAT_DATA_REL_RO:
5055 named_section (NULL_TREE, ".data.rel.ro", reloc);
5056 break;
5057 case SECCAT_DATA_REL_RO_LOCAL:
5058 named_section (NULL_TREE, ".data.rel.ro.local", reloc);
5059 break;
5060 case SECCAT_SDATA:
5061 named_section (NULL_TREE, ".sdata", reloc);
5062 break;
5063 case SECCAT_TDATA:
5064 named_section (NULL_TREE, ".tdata", reloc);
5065 break;
5066 case SECCAT_BSS:
5067 #ifdef BSS_SECTION_ASM_OP
5068 bss_section ();
5069 #else
5070 named_section (NULL_TREE, ".bss", reloc);
5071 #endif
5072 break;
5073 case SECCAT_SBSS:
5074 named_section (NULL_TREE, ".sbss", reloc);
5075 break;
5076 case SECCAT_TBSS:
5077 named_section (NULL_TREE, ".tbss", reloc);
5078 break;
5079 default:
5080 abort ();
5084 /* Construct a unique section name based on the decl name and the
5085 categorization performed above. */
5087 void
5088 default_unique_section (tree decl, int reloc)
5090 default_unique_section_1 (decl, reloc, flag_pic);
5093 void
5094 default_unique_section_1 (tree decl, int reloc, int shlib)
5096 bool one_only = DECL_ONE_ONLY (decl);
5097 const char *prefix, *name;
5098 size_t nlen, plen;
5099 char *string;
5101 switch (categorize_decl_for_section (decl, reloc, shlib))
5103 case SECCAT_TEXT:
5104 prefix = one_only ? ".gnu.linkonce.t." : ".text.";
5105 break;
5106 case SECCAT_RODATA:
5107 case SECCAT_RODATA_MERGE_STR:
5108 case SECCAT_RODATA_MERGE_STR_INIT:
5109 case SECCAT_RODATA_MERGE_CONST:
5110 prefix = one_only ? ".gnu.linkonce.r." : ".rodata.";
5111 break;
5112 case SECCAT_SRODATA:
5113 prefix = one_only ? ".gnu.linkonce.s2." : ".sdata2.";
5114 break;
5115 case SECCAT_DATA:
5116 case SECCAT_DATA_REL:
5117 case SECCAT_DATA_REL_LOCAL:
5118 case SECCAT_DATA_REL_RO:
5119 case SECCAT_DATA_REL_RO_LOCAL:
5120 prefix = one_only ? ".gnu.linkonce.d." : ".data.";
5121 break;
5122 case SECCAT_SDATA:
5123 prefix = one_only ? ".gnu.linkonce.s." : ".sdata.";
5124 break;
5125 case SECCAT_BSS:
5126 prefix = one_only ? ".gnu.linkonce.b." : ".bss.";
5127 break;
5128 case SECCAT_SBSS:
5129 prefix = one_only ? ".gnu.linkonce.sb." : ".sbss.";
5130 break;
5131 case SECCAT_TDATA:
5132 prefix = one_only ? ".gnu.linkonce.td." : ".tdata.";
5133 break;
5134 case SECCAT_TBSS:
5135 prefix = one_only ? ".gnu.linkonce.tb." : ".tbss.";
5136 break;
5137 default:
5138 abort ();
5140 plen = strlen (prefix);
5142 name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
5143 name = (* targetm.strip_name_encoding) (name);
5144 nlen = strlen (name);
5146 string = alloca (nlen + plen + 1);
5147 memcpy (string, prefix, plen);
5148 memcpy (string + plen, name, nlen + 1);
5150 DECL_SECTION_NAME (decl) = build_string (nlen + plen, string);
5153 void
5154 default_select_rtx_section (enum machine_mode mode ATTRIBUTE_UNUSED,
5155 rtx x,
5156 unsigned HOST_WIDE_INT align ATTRIBUTE_UNUSED)
5158 if (flag_pic)
5159 switch (GET_CODE (x))
5161 case CONST:
5162 case SYMBOL_REF:
5163 case LABEL_REF:
5164 data_section ();
5165 return;
5167 default:
5168 break;
5171 readonly_data_section ();
5174 void
5175 default_elf_select_rtx_section (enum machine_mode mode, rtx x,
5176 unsigned HOST_WIDE_INT align)
5178 /* ??? Handle small data here somehow. */
5180 if (flag_pic)
5181 switch (GET_CODE (x))
5183 case CONST:
5184 case SYMBOL_REF:
5185 named_section (NULL_TREE, ".data.rel.ro", 3);
5186 return;
5188 case LABEL_REF:
5189 named_section (NULL_TREE, ".data.rel.ro.local", 1);
5190 return;
5192 default:
5193 break;
5196 mergeable_constant_section (mode, align, 0);
5199 /* Set the generally applicable flags on the SYMBOL_REF for EXP. */
5201 void
5202 default_encode_section_info (tree decl, rtx rtl, int first ATTRIBUTE_UNUSED)
5204 rtx symbol;
5205 int flags;
5207 /* Careful not to prod global register variables. */
5208 if (GET_CODE (rtl) != MEM)
5209 return;
5210 symbol = XEXP (rtl, 0);
5211 if (GET_CODE (symbol) != SYMBOL_REF)
5212 return;
5214 flags = 0;
5215 if (TREE_CODE (decl) == FUNCTION_DECL)
5216 flags |= SYMBOL_FLAG_FUNCTION;
5217 if ((*targetm.binds_local_p) (decl))
5218 flags |= SYMBOL_FLAG_LOCAL;
5219 if ((*targetm.in_small_data_p) (decl))
5220 flags |= SYMBOL_FLAG_SMALL;
5221 if (TREE_CODE (decl) == VAR_DECL && DECL_THREAD_LOCAL (decl))
5222 flags |= decl_tls_model (decl) << SYMBOL_FLAG_TLS_SHIFT;
5223 /* ??? Why is DECL_EXTERNAL ever set for non-PUBLIC names? Without
5224 being PUBLIC, the thing *must* be defined in this translation unit.
5225 Prevent this buglet from being propagated into rtl code as well. */
5226 if (DECL_P (decl) && DECL_EXTERNAL (decl) && TREE_PUBLIC (decl))
5227 flags |= SYMBOL_FLAG_EXTERNAL;
5229 SYMBOL_REF_FLAGS (symbol) = flags;
5232 /* By default, we do nothing for encode_section_info, so we need not
5233 do anything but discard the '*' marker. */
5235 const char *
5236 default_strip_name_encoding (const char *str)
5238 return str + (*str == '*');
5241 /* Assume ELF-ish defaults, since that's pretty much the most liberal
5242 wrt cross-module name binding. */
5244 bool
5245 default_binds_local_p (tree exp)
5247 return default_binds_local_p_1 (exp, flag_shlib);
5250 bool
5251 default_binds_local_p_1 (tree exp, int shlib)
5253 bool local_p;
5255 /* A non-decl is an entry in the constant pool. */
5256 if (!DECL_P (exp))
5257 local_p = true;
5258 /* Static variables are always local. */
5259 else if (! TREE_PUBLIC (exp))
5260 local_p = true;
5261 /* A variable is local if the user explicitly tells us so. */
5262 else if (DECL_VISIBILITY_SPECIFIED (exp) && DECL_VISIBILITY (exp) != VISIBILITY_DEFAULT)
5263 local_p = true;
5264 /* Otherwise, variables defined outside this object may not be local. */
5265 else if (DECL_EXTERNAL (exp))
5266 local_p = false;
5267 /* Linkonce and weak data are never local. */
5268 else if (DECL_ONE_ONLY (exp) || DECL_WEAK (exp))
5269 local_p = false;
5270 /* If none of the above and visibility is not default, make local. */
5271 else if (DECL_VISIBILITY (exp) != VISIBILITY_DEFAULT)
5272 local_p = true;
5273 /* If PIC, then assume that any global name can be overridden by
5274 symbols resolved from other modules. */
5275 else if (shlib)
5276 local_p = false;
5277 /* Uninitialized COMMON variable may be unified with symbols
5278 resolved from other modules. */
5279 else if (DECL_COMMON (exp)
5280 && (DECL_INITIAL (exp) == NULL
5281 || DECL_INITIAL (exp) == error_mark_node))
5282 local_p = false;
5283 /* Otherwise we're left with initialized (or non-common) global data
5284 which is of necessity defined locally. */
5285 else
5286 local_p = true;
5288 return local_p;
5291 /* Determine whether or not a pointer mode is valid. Assume defaults
5292 of ptr_mode or Pmode - can be overridden. */
5293 bool
5294 default_valid_pointer_mode (enum machine_mode mode)
5296 return (mode == ptr_mode || mode == Pmode);
5299 /* Default function to output code that will globalize a label. A
5300 target must define GLOBAL_ASM_OP or provide it's own function to
5301 globalize a label. */
5302 #ifdef GLOBAL_ASM_OP
5303 void
5304 default_globalize_label (FILE * stream, const char *name)
5306 fputs (GLOBAL_ASM_OP, stream);
5307 assemble_name (stream, name);
5308 putc ('\n', stream);
5310 #endif /* GLOBAL_ASM_OP */
5312 /* This is how to output an internal numbered label where PREFIX is
5313 the class of label and LABELNO is the number within the class. */
5315 void
5316 default_internal_label (FILE *stream, const char *prefix,
5317 unsigned long labelno)
5319 char *const buf = alloca (40 + strlen (prefix));
5320 ASM_GENERATE_INTERNAL_LABEL (buf, prefix, labelno);
5321 ASM_OUTPUT_LABEL (stream, buf);
5324 /* This is the default behavior at the beginning of a file. It's
5325 controlled by two other target-hook toggles. */
5326 void
5327 default_file_start (void)
5329 if (targetm.file_start_app_off && !flag_verbose_asm)
5330 fputs (ASM_APP_OFF, asm_out_file);
5332 if (targetm.file_start_file_directive)
5333 output_file_directive (asm_out_file, main_input_filename);
5336 /* This is a generic routine suitable for use as TARGET_ASM_FILE_END
5337 which emits a special section directive used to indicate whether or
5338 not this object file needs an executable stack. This is primarily
5339 a GNU extension to ELF but could be used on other targets. */
5340 void
5341 file_end_indicate_exec_stack (void)
5343 unsigned int flags = SECTION_DEBUG;
5344 if (trampolines_created)
5345 flags |= SECTION_CODE;
5347 named_section_flags (".note.GNU-stack", flags);
5350 #include "gt-varasm.h"