varasm.c (MAX_OFILE_ALIGNMENT): Move ...
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1 /* Output variables, constants and external declarations, for GNU compiler.
2 Copyright (C) 1987, 1988, 1989, 1992, 1993, 1994, 1995, 1996, 1997,
3 1998, 1999, 2000, 2001, 2002, 2003, 2004 Free Software Foundation, Inc.
4
5 This file is part of GCC.
6
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.
11
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.
16
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. */
21
22
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.
26
27 We also output the assembler code for constants stored in memory
28 and are responsible for combining constants with the same value. */
29
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 "tree-mudflap.h"
52 #include "cgraph.h"
53 #include "cfglayout.h"
54
55 #ifdef XCOFF_DEBUGGING_INFO
56 #include "xcoffout.h" /* Needed for external data
57 declarations for e.g. AIX 4.x. */
58 #endif
59
60 #ifndef ASM_STABS_OP
61 #define ASM_STABS_OP "\t.stabs\t"
62 #endif
63
64 /* The (assembler) name of the first globally-visible object output. */
65 const char *first_global_object_name;
66 const char *weak_global_object_name;
67
68 struct addr_const;
69 struct constant_descriptor_rtx;
70 struct rtx_constant_pool;
71
72 struct varasm_status GTY(())
73 {
74 /* If we're using a per-function constant pool, this is it. */
75 struct rtx_constant_pool *pool;
76
77 /* Number of tree-constants deferred during the expansion of this
78 function. */
79 unsigned int deferred_constants;
80 };
81
82 #define n_deferred_constants (cfun->varasm->deferred_constants)
83
84 /* Number for making the label on the next
85 constant that is stored in memory. */
86
87 static GTY(()) int const_labelno;
88
89 /* Carry information from ASM_DECLARE_OBJECT_NAME
90 to ASM_FINISH_DECLARE_OBJECT. */
91
92 int size_directive_output;
93
94 /* The last decl for which assemble_variable was called,
95 if it did ASM_DECLARE_OBJECT_NAME.
96 If the last call to assemble_variable didn't do that,
97 this holds 0. */
98
99 tree last_assemble_variable_decl;
100
101 /* The following global variable indicates if the section label for the
102 "cold" section of code has been output yet to the assembler. The
103 label is useful when running gdb. This is part of the optimization that
104 partitions hot and cold basic blocks into separate sections of the .o
105 file. */
106
107 bool unlikely_section_label_printed = false;
108
109 /* The following global variable indicates the label name to be put at
110 the start of the first cold section within each function, when
111 partitioning basic blocks into hot and cold sections. */
112
113 char *unlikely_section_label = NULL;
114
115 /* The following global variable indicates the section name to be used
116 for the current cold section, when partitioning hot and cold basic
117 blocks into separate sections. */
118
119 char *unlikely_text_section_name = NULL;
120
121 /* RTX_UNCHANGING_P in a MEM can mean it is stored into, for initialization.
122 So giving constant the alias set for the type will allow such
123 initializations to appear to conflict with the load of the constant. We
124 avoid this by giving all constants an alias set for just constants.
125 Since there will be no stores to that alias set, nothing will ever
126 conflict with them. */
127
128 static HOST_WIDE_INT const_alias_set;
129
130 static const char *strip_reg_name (const char *);
131 static int contains_pointers_p (tree);
132 #ifdef ASM_OUTPUT_EXTERNAL
133 static bool incorporeal_function_p (tree);
134 #endif
135 static void decode_addr_const (tree, struct addr_const *);
136 static hashval_t const_desc_hash (const void *);
137 static int const_desc_eq (const void *, const void *);
138 static hashval_t const_hash_1 (const tree);
139 static int compare_constant (const tree, const tree);
140 static tree copy_constant (tree);
141 static void output_constant_def_contents (rtx);
142 static void output_addressed_constants (tree);
143 static unsigned HOST_WIDE_INT array_size_for_constructor (tree);
144 static unsigned min_align (unsigned, unsigned);
145 static void output_constructor (tree, unsigned HOST_WIDE_INT, unsigned int);
146 static void globalize_decl (tree);
147 static void maybe_assemble_visibility (tree);
148 static int in_named_entry_eq (const void *, const void *);
149 static hashval_t in_named_entry_hash (const void *);
150 #ifdef BSS_SECTION_ASM_OP
151 #ifdef ASM_OUTPUT_BSS
152 static void asm_output_bss (FILE *, tree, const char *,
153 unsigned HOST_WIDE_INT, unsigned HOST_WIDE_INT);
154 #endif
155 #ifdef ASM_OUTPUT_ALIGNED_BSS
156 static void asm_output_aligned_bss (FILE *, tree, const char *,
157 unsigned HOST_WIDE_INT, int)
158 ATTRIBUTE_UNUSED;
159 #endif
160 #endif /* BSS_SECTION_ASM_OP */
161 static bool asm_emit_uninitialised (tree, const char*,
162 unsigned HOST_WIDE_INT,
163 unsigned HOST_WIDE_INT);
164 static void mark_weak (tree);
165 \f
166 enum in_section { no_section, in_text, in_unlikely_executed_text, in_data,
167 in_named
168 #ifdef BSS_SECTION_ASM_OP
169 , in_bss
170 #endif
171 #ifdef CTORS_SECTION_ASM_OP
172 , in_ctors
173 #endif
174 #ifdef DTORS_SECTION_ASM_OP
175 , in_dtors
176 #endif
177 #ifdef READONLY_DATA_SECTION_ASM_OP
178 , in_readonly_data
179 #endif
180 #ifdef EXTRA_SECTIONS
181 , EXTRA_SECTIONS
182 #endif
183 };
184 static GTY(()) enum in_section in_section = no_section;
185
186 /* Return a nonzero value if DECL has a section attribute. */
187 #ifndef IN_NAMED_SECTION
188 #define IN_NAMED_SECTION(DECL) \
189 ((TREE_CODE (DECL) == FUNCTION_DECL || TREE_CODE (DECL) == VAR_DECL) \
190 && DECL_SECTION_NAME (DECL) != NULL_TREE)
191 #endif
192
193 /* Text of section name when in_section == in_named. */
194 static GTY(()) const char *in_named_name;
195
196 /* Hash table of flags that have been used for a particular named section. */
197
198 struct in_named_entry GTY(())
199 {
200 const char *name;
201 unsigned int flags;
202 bool declared;
203 };
204
205 static GTY((param_is (struct in_named_entry))) htab_t in_named_htab;
206
207 /* Define functions like text_section for any extra sections. */
208 #ifdef EXTRA_SECTION_FUNCTIONS
209 EXTRA_SECTION_FUNCTIONS
210 #endif
211
212 /* Tell assembler to switch to text section. */
213
214 void
215 text_section (void)
216 {
217 if (in_section != in_text)
218 {
219 in_section = in_text;
220 fprintf (asm_out_file, "%s\n", TEXT_SECTION_ASM_OP);
221 }
222 }
223
224 /* Tell assembler to switch to unlikely-to-be-executed text section. */
225
226 void
227 unlikely_text_section (void)
228 {
229 if ((in_section != in_unlikely_executed_text)
230 && (in_section != in_named
231 || strcmp (in_named_name, UNLIKELY_EXECUTED_TEXT_SECTION_NAME) != 0))
232 {
233 if (targetm.have_named_sections)
234 named_section (NULL_TREE, UNLIKELY_EXECUTED_TEXT_SECTION_NAME, 0);
235 else
236 {
237 in_section = in_unlikely_executed_text;
238 fprintf (asm_out_file, "%s\n", TEXT_SECTION_ASM_OP);
239 }
240
241 if (!unlikely_section_label_printed)
242 {
243 ASM_OUTPUT_LABEL (asm_out_file, unlikely_section_label);
244 unlikely_section_label_printed = true;
245 }
246 }
247 }
248
249 /* Tell assembler to switch to data section. */
250
251 void
252 data_section (void)
253 {
254 if (in_section != in_data)
255 {
256 in_section = in_data;
257 fprintf (asm_out_file, "%s\n", DATA_SECTION_ASM_OP);
258 }
259 }
260
261 /* Tell assembler to switch to read-only data section. This is normally
262 the text section. */
263
264 void
265 readonly_data_section (void)
266 {
267 #ifdef READONLY_DATA_SECTION
268 READONLY_DATA_SECTION (); /* Note this can call data_section. */
269 #else
270 #ifdef READONLY_DATA_SECTION_ASM_OP
271 if (in_section != in_readonly_data)
272 {
273 in_section = in_readonly_data;
274 fputs (READONLY_DATA_SECTION_ASM_OP, asm_out_file);
275 fputc ('\n', asm_out_file);
276 }
277 #else
278 text_section ();
279 #endif
280 #endif
281 }
282
283 /* Determine if we're in the text section. */
284
285 int
286 in_text_section (void)
287 {
288 return in_section == in_text;
289 }
290
291 /* Determine if we're in the unlikely-to-be-executed text section. */
292
293 int
294 in_unlikely_text_section (void)
295 {
296 return in_section == in_unlikely_executed_text;
297 }
298
299 /* Determine if we're in the data section. */
300
301 int
302 in_data_section (void)
303 {
304 return in_section == in_data;
305 }
306
307 /* Helper routines for maintaining in_named_htab. */
308
309 static int
310 in_named_entry_eq (const void *p1, const void *p2)
311 {
312 const struct in_named_entry *old = p1;
313 const char *new = p2;
314
315 return strcmp (old->name, new) == 0;
316 }
317
318 static hashval_t
319 in_named_entry_hash (const void *p)
320 {
321 const struct in_named_entry *old = p;
322 return htab_hash_string (old->name);
323 }
324
325 /* If SECTION has been seen before as a named section, return the flags
326 that were used. Otherwise, return 0. Note, that 0 is a perfectly valid
327 set of flags for a section to have, so 0 does not mean that the section
328 has not been seen. */
329
330 unsigned int
331 get_named_section_flags (const char *section)
332 {
333 struct in_named_entry **slot;
334
335 slot = (struct in_named_entry **)
336 htab_find_slot_with_hash (in_named_htab, section,
337 htab_hash_string (section), NO_INSERT);
338
339 return slot ? (*slot)->flags : 0;
340 }
341
342 /* Returns true if the section has been declared before. Sets internal
343 flag on this section in in_named_hash so subsequent calls on this
344 section will return false. */
345
346 bool
347 named_section_first_declaration (const char *name)
348 {
349 struct in_named_entry **slot;
350
351 slot = (struct in_named_entry **)
352 htab_find_slot_with_hash (in_named_htab, name,
353 htab_hash_string (name), NO_INSERT);
354 if (! (*slot)->declared)
355 {
356 (*slot)->declared = true;
357 return true;
358 }
359 else
360 {
361 return false;
362 }
363 }
364
365
366 /* Record FLAGS for SECTION. If SECTION was previously recorded with a
367 different set of flags, return false. */
368
369 bool
370 set_named_section_flags (const char *section, unsigned int flags)
371 {
372 struct in_named_entry **slot, *entry;
373
374 slot = (struct in_named_entry **)
375 htab_find_slot_with_hash (in_named_htab, section,
376 htab_hash_string (section), INSERT);
377 entry = *slot;
378
379 if (!entry)
380 {
381 entry = ggc_alloc (sizeof (*entry));
382 *slot = entry;
383 entry->name = ggc_strdup (section);
384 entry->flags = flags;
385 entry->declared = false;
386 }
387 else if (entry->flags != flags)
388 return false;
389
390 return true;
391 }
392
393 /* Tell assembler to change to section NAME with attributes FLAGS. */
394
395 void
396 named_section_flags (const char *name, unsigned int flags)
397 {
398 if (in_section != in_named || strcmp (name, in_named_name) != 0)
399 {
400 if (! set_named_section_flags (name, flags))
401 abort ();
402
403 targetm.asm_out.named_section (name, flags);
404
405 if (flags & SECTION_FORGET)
406 in_section = no_section;
407 else
408 {
409 in_named_name = ggc_strdup (name);
410 in_section = in_named;
411 }
412 }
413 }
414
415 /* Tell assembler to change to section NAME for DECL.
416 If DECL is NULL, just switch to section NAME.
417 If NAME is NULL, get the name from DECL.
418 If RELOC is 1, the initializer for DECL contains relocs. */
419
420 void
421 named_section (tree decl, const char *name, int reloc)
422 {
423 unsigned int flags;
424
425 if (decl != NULL_TREE && !DECL_P (decl))
426 abort ();
427 if (name == NULL)
428 name = TREE_STRING_POINTER (DECL_SECTION_NAME (decl));
429
430 flags = targetm.section_type_flags (decl, name, reloc);
431
432 /* Sanity check user variables for flag changes. Non-user
433 section flag changes will abort in named_section_flags.
434 However, don't complain if SECTION_OVERRIDE is set.
435 We trust that the setter knows that it is safe to ignore
436 the default flags for this decl. */
437 if (decl && ! set_named_section_flags (name, flags))
438 {
439 flags = get_named_section_flags (name);
440 if ((flags & SECTION_OVERRIDE) == 0)
441 error ("%J%D causes a section type conflict", decl, decl);
442 }
443
444 named_section_flags (name, flags);
445 }
446
447 /* If required, set DECL_SECTION_NAME to a unique name. */
448
449 void
450 resolve_unique_section (tree decl, int reloc ATTRIBUTE_UNUSED,
451 int flag_function_or_data_sections)
452 {
453 if (DECL_SECTION_NAME (decl) == NULL_TREE
454 && targetm.have_named_sections
455 && (flag_function_or_data_sections
456 || DECL_ONE_ONLY (decl)))
457 targetm.asm_out.unique_section (decl, reloc);
458 }
459
460 #ifdef BSS_SECTION_ASM_OP
461
462 /* Tell the assembler to switch to the bss section. */
463
464 void
465 bss_section (void)
466 {
467 if (in_section != in_bss)
468 {
469 fprintf (asm_out_file, "%s\n", BSS_SECTION_ASM_OP);
470 in_section = in_bss;
471 }
472 }
473
474 #ifdef ASM_OUTPUT_BSS
475
476 /* Utility function for ASM_OUTPUT_BSS for targets to use if
477 they don't support alignments in .bss.
478 ??? It is believed that this function will work in most cases so such
479 support is localized here. */
480
481 static void
482 asm_output_bss (FILE *file, tree decl ATTRIBUTE_UNUSED,
483 const char *name,
484 unsigned HOST_WIDE_INT size ATTRIBUTE_UNUSED,
485 unsigned HOST_WIDE_INT rounded)
486 {
487 targetm.asm_out.globalize_label (file, name);
488 bss_section ();
489 #ifdef ASM_DECLARE_OBJECT_NAME
490 last_assemble_variable_decl = decl;
491 ASM_DECLARE_OBJECT_NAME (file, name, decl);
492 #else
493 /* Standard thing is just output label for the object. */
494 ASM_OUTPUT_LABEL (file, name);
495 #endif /* ASM_DECLARE_OBJECT_NAME */
496 ASM_OUTPUT_SKIP (file, rounded ? rounded : 1);
497 }
498
499 #endif
500
501 #ifdef ASM_OUTPUT_ALIGNED_BSS
502
503 /* Utility function for targets to use in implementing
504 ASM_OUTPUT_ALIGNED_BSS.
505 ??? It is believed that this function will work in most cases so such
506 support is localized here. */
507
508 static void
509 asm_output_aligned_bss (FILE *file, tree decl ATTRIBUTE_UNUSED,
510 const char *name, unsigned HOST_WIDE_INT size,
511 int align)
512 {
513 bss_section ();
514 ASM_OUTPUT_ALIGN (file, floor_log2 (align / BITS_PER_UNIT));
515 #ifdef ASM_DECLARE_OBJECT_NAME
516 last_assemble_variable_decl = decl;
517 ASM_DECLARE_OBJECT_NAME (file, name, decl);
518 #else
519 /* Standard thing is just output label for the object. */
520 ASM_OUTPUT_LABEL (file, name);
521 #endif /* ASM_DECLARE_OBJECT_NAME */
522 ASM_OUTPUT_SKIP (file, size ? size : 1);
523 }
524
525 #endif
526
527 #endif /* BSS_SECTION_ASM_OP */
528
529 /* Switch to the section for function DECL.
530
531 If DECL is NULL_TREE, switch to the text section.
532 ??? It's not clear that we will ever be passed NULL_TREE, but it's
533 safer to handle it. */
534
535 void
536 function_section (tree decl)
537 {
538 if (scan_ahead_for_unlikely_executed_note (get_insns()))
539 unlikely_text_section ();
540 else
541 {
542 if (decl != NULL_TREE
543 && DECL_SECTION_NAME (decl) != NULL_TREE)
544 named_section (decl, (char *) 0, 0);
545 else
546 text_section ();
547 }
548 }
549
550 /* Switch to read-only data section associated with function DECL. */
551
552 void
553 default_function_rodata_section (tree decl)
554 {
555 if (decl != NULL_TREE && DECL_SECTION_NAME (decl))
556 {
557 const char *name = TREE_STRING_POINTER (DECL_SECTION_NAME (decl));
558
559 /* For .gnu.linkonce.t.foo we want to use .gnu.linkonce.r.foo. */
560 if (DECL_ONE_ONLY (decl) && strncmp (name, ".gnu.linkonce.t.", 16) == 0)
561 {
562 size_t len = strlen (name) + 1;
563 char *rname = alloca (len);
564
565 memcpy (rname, name, len);
566 rname[14] = 'r';
567 named_section_flags (rname, SECTION_LINKONCE);
568 return;
569 }
570 /* For .text.foo we want to use .rodata.foo. */
571 else if (flag_function_sections && flag_data_sections
572 && strncmp (name, ".text.", 6) == 0)
573 {
574 size_t len = strlen (name) + 1;
575 char *rname = alloca (len + 2);
576
577 memcpy (rname, ".rodata", 7);
578 memcpy (rname + 7, name + 5, len - 5);
579 named_section_flags (rname, 0);
580 return;
581 }
582 }
583
584 readonly_data_section ();
585 }
586
587 /* Switch to read-only data section associated with function DECL
588 for targets where that section should be always the single
589 readonly data section. */
590
591 void
592 default_no_function_rodata_section (tree decl ATTRIBUTE_UNUSED)
593 {
594 readonly_data_section ();
595 }
596
597 /* Switch to section for variable DECL. RELOC is the same as the
598 argument to SELECT_SECTION. */
599
600 void
601 variable_section (tree decl, int reloc)
602 {
603 if (IN_NAMED_SECTION (decl))
604 named_section (decl, NULL, reloc);
605 else
606 targetm.asm_out.select_section (decl, reloc, DECL_ALIGN (decl));
607 }
608
609 /* Tell assembler to switch to the section for string merging. */
610
611 void
612 mergeable_string_section (tree decl ATTRIBUTE_UNUSED,
613 unsigned HOST_WIDE_INT align ATTRIBUTE_UNUSED,
614 unsigned int flags ATTRIBUTE_UNUSED)
615 {
616 if (HAVE_GAS_SHF_MERGE && flag_merge_constants
617 && TREE_CODE (decl) == STRING_CST
618 && TREE_CODE (TREE_TYPE (decl)) == ARRAY_TYPE
619 && align <= 256
620 && TREE_STRING_LENGTH (decl) >= int_size_in_bytes (TREE_TYPE (decl)))
621 {
622 enum machine_mode mode;
623 unsigned int modesize;
624 const char *str;
625 int i, j, len, unit;
626 char name[30];
627
628 mode = TYPE_MODE (TREE_TYPE (TREE_TYPE (decl)));
629 modesize = GET_MODE_BITSIZE (mode);
630 if (modesize >= 8 && modesize <= 256
631 && (modesize & (modesize - 1)) == 0)
632 {
633 if (align < modesize)
634 align = modesize;
635
636 str = TREE_STRING_POINTER (decl);
637 len = TREE_STRING_LENGTH (decl);
638 unit = GET_MODE_SIZE (mode);
639
640 /* Check for embedded NUL characters. */
641 for (i = 0; i < len; i += unit)
642 {
643 for (j = 0; j < unit; j++)
644 if (str[i + j] != '\0')
645 break;
646 if (j == unit)
647 break;
648 }
649 if (i == len - unit)
650 {
651 sprintf (name, ".rodata.str%d.%d", modesize / 8,
652 (int) (align / 8));
653 flags |= (modesize / 8) | SECTION_MERGE | SECTION_STRINGS;
654 if (!i && modesize < align)
655 {
656 /* A "" string with requested alignment greater than
657 character size might cause a problem:
658 if some other string required even bigger
659 alignment than "", then linker might think the
660 "" is just part of padding after some other string
661 and not put it into the hash table initially.
662 But this means "" could have smaller alignment
663 than requested. */
664 #ifdef ASM_OUTPUT_SECTION_START
665 named_section_flags (name, flags);
666 ASM_OUTPUT_SECTION_START (asm_out_file);
667 #else
668 readonly_data_section ();
669 #endif
670 return;
671 }
672
673 named_section_flags (name, flags);
674 return;
675 }
676 }
677 }
678
679 readonly_data_section ();
680 }
681
682 /* Tell assembler to switch to the section for constant merging. */
683
684 void
685 mergeable_constant_section (enum machine_mode mode ATTRIBUTE_UNUSED,
686 unsigned HOST_WIDE_INT align ATTRIBUTE_UNUSED,
687 unsigned int flags ATTRIBUTE_UNUSED)
688 {
689 unsigned int modesize = GET_MODE_BITSIZE (mode);
690
691 if (HAVE_GAS_SHF_MERGE && flag_merge_constants
692 && mode != VOIDmode
693 && mode != BLKmode
694 && modesize <= align
695 && align >= 8
696 && align <= 256
697 && (align & (align - 1)) == 0)
698 {
699 char name[24];
700
701 sprintf (name, ".rodata.cst%d", (int) (align / 8));
702 flags |= (align / 8) | SECTION_MERGE;
703 named_section_flags (name, flags);
704 return;
705 }
706
707 readonly_data_section ();
708 }
709 \f
710 /* Given NAME, a putative register name, discard any customary prefixes. */
711
712 static const char *
713 strip_reg_name (const char *name)
714 {
715 #ifdef REGISTER_PREFIX
716 if (!strncmp (name, REGISTER_PREFIX, strlen (REGISTER_PREFIX)))
717 name += strlen (REGISTER_PREFIX);
718 #endif
719 if (name[0] == '%' || name[0] == '#')
720 name++;
721 return name;
722 }
723 \f
724 /* The user has asked for a DECL to have a particular name. Set (or
725 change) it in such a way that we don't prefix an underscore to
726 it. */
727 void
728 set_user_assembler_name (tree decl, const char *name)
729 {
730 char *starred = alloca (strlen (name) + 2);
731 starred[0] = '*';
732 strcpy (starred + 1, name);
733 change_decl_assembler_name (decl, get_identifier (starred));
734 SET_DECL_RTL (decl, NULL_RTX);
735 }
736 \f
737 /* Decode an `asm' spec for a declaration as a register name.
738 Return the register number, or -1 if nothing specified,
739 or -2 if the ASMSPEC is not `cc' or `memory' and is not recognized,
740 or -3 if ASMSPEC is `cc' and is not recognized,
741 or -4 if ASMSPEC is `memory' and is not recognized.
742 Accept an exact spelling or a decimal number.
743 Prefixes such as % are optional. */
744
745 int
746 decode_reg_name (const char *asmspec)
747 {
748 if (asmspec != 0)
749 {
750 int i;
751
752 /* Get rid of confusing prefixes. */
753 asmspec = strip_reg_name (asmspec);
754
755 /* Allow a decimal number as a "register name". */
756 for (i = strlen (asmspec) - 1; i >= 0; i--)
757 if (! ISDIGIT (asmspec[i]))
758 break;
759 if (asmspec[0] != 0 && i < 0)
760 {
761 i = atoi (asmspec);
762 if (i < FIRST_PSEUDO_REGISTER && i >= 0)
763 return i;
764 else
765 return -2;
766 }
767
768 for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
769 if (reg_names[i][0]
770 && ! strcmp (asmspec, strip_reg_name (reg_names[i])))
771 return i;
772
773 #ifdef ADDITIONAL_REGISTER_NAMES
774 {
775 static const struct { const char *const name; const int number; } table[]
776 = ADDITIONAL_REGISTER_NAMES;
777
778 for (i = 0; i < (int) ARRAY_SIZE (table); i++)
779 if (! strcmp (asmspec, table[i].name))
780 return table[i].number;
781 }
782 #endif /* ADDITIONAL_REGISTER_NAMES */
783
784 if (!strcmp (asmspec, "memory"))
785 return -4;
786
787 if (!strcmp (asmspec, "cc"))
788 return -3;
789
790 return -2;
791 }
792
793 return -1;
794 }
795 \f
796 /* Create the DECL_RTL for a VAR_DECL or FUNCTION_DECL. DECL should
797 have static storage duration. In other words, it should not be an
798 automatic variable, including PARM_DECLs.
799
800 There is, however, one exception: this function handles variables
801 explicitly placed in a particular register by the user.
802
803 This is never called for PARM_DECL nodes. */
804
805 void
806 make_decl_rtl (tree decl)
807 {
808 const char *name = 0;
809 int reg_number;
810 rtx x;
811
812 /* Check that we are not being given an automatic variable. */
813 /* A weak alias has TREE_PUBLIC set but not the other bits. */
814 if (TREE_CODE (decl) == PARM_DECL
815 || TREE_CODE (decl) == RESULT_DECL
816 || (TREE_CODE (decl) == VAR_DECL
817 && !TREE_STATIC (decl)
818 && !TREE_PUBLIC (decl)
819 && !DECL_EXTERNAL (decl)
820 && !DECL_REGISTER (decl)))
821 abort ();
822 /* And that we were not given a type or a label. */
823 else if (TREE_CODE (decl) == TYPE_DECL
824 || TREE_CODE (decl) == LABEL_DECL)
825 abort ();
826
827 /* For a duplicate declaration, we can be called twice on the
828 same DECL node. Don't discard the RTL already made. */
829 if (DECL_RTL_SET_P (decl))
830 {
831 /* If the old RTL had the wrong mode, fix the mode. */
832 if (GET_MODE (DECL_RTL (decl)) != DECL_MODE (decl))
833 SET_DECL_RTL (decl, adjust_address_nv (DECL_RTL (decl),
834 DECL_MODE (decl), 0));
835
836 if (TREE_CODE (decl) != FUNCTION_DECL && DECL_REGISTER (decl))
837 return;
838
839 /* ??? Another way to do this would be to maintain a hashed
840 table of such critters. Instead of adding stuff to a DECL
841 to give certain attributes to it, we could use an external
842 hash map from DECL to set of attributes. */
843
844 /* Let the target reassign the RTL if it wants.
845 This is necessary, for example, when one machine specific
846 decl attribute overrides another. */
847 targetm.encode_section_info (decl, DECL_RTL (decl), false);
848
849 /* Make this function static known to the mudflap runtime. */
850 if (flag_mudflap && TREE_CODE (decl) == VAR_DECL)
851 mudflap_enqueue_decl (decl);
852
853 return;
854 }
855
856 name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
857
858 reg_number = decode_reg_name (name);
859
860 if (TREE_CODE (decl) != FUNCTION_DECL && DECL_REGISTER (decl))
861 {
862 /* First detect errors in declaring global registers. */
863 if (reg_number == -1)
864 error ("%Jregister name not specified for '%D'", decl, decl);
865 else if (reg_number < 0)
866 error ("%Jinvalid register name for '%D'", decl, decl);
867 else if (TYPE_MODE (TREE_TYPE (decl)) == BLKmode)
868 error ("%Jdata type of '%D' isn't suitable for a register",
869 decl, decl);
870 else if (! HARD_REGNO_MODE_OK (reg_number, TYPE_MODE (TREE_TYPE (decl))))
871 error ("%Jregister specified for '%D' isn't suitable for data type",
872 decl, decl);
873 /* Now handle properly declared static register variables. */
874 else
875 {
876 int nregs;
877
878 if (DECL_INITIAL (decl) != 0 && TREE_STATIC (decl))
879 {
880 DECL_INITIAL (decl) = 0;
881 error ("global register variable has initial value");
882 }
883 if (TREE_THIS_VOLATILE (decl))
884 warning ("volatile register variables don't work as you might wish");
885
886 /* If the user specified one of the eliminables registers here,
887 e.g., FRAME_POINTER_REGNUM, we don't want to get this variable
888 confused with that register and be eliminated. This usage is
889 somewhat suspect... */
890
891 SET_DECL_RTL (decl, gen_rtx_raw_REG (DECL_MODE (decl), reg_number));
892 ORIGINAL_REGNO (DECL_RTL (decl)) = reg_number;
893 REG_USERVAR_P (DECL_RTL (decl)) = 1;
894
895 if (TREE_STATIC (decl))
896 {
897 /* Make this register global, so not usable for anything
898 else. */
899 #ifdef ASM_DECLARE_REGISTER_GLOBAL
900 ASM_DECLARE_REGISTER_GLOBAL (asm_out_file, decl, reg_number, name);
901 #endif
902 nregs = hard_regno_nregs[reg_number][DECL_MODE (decl)];
903 while (nregs > 0)
904 globalize_reg (reg_number + --nregs);
905 }
906
907 /* As a register variable, it has no section. */
908 return;
909 }
910 }
911
912 /* Now handle ordinary static variables and functions (in memory).
913 Also handle vars declared register invalidly. */
914
915 if (name[0] == '*' && (reg_number >= 0 || reg_number == -3))
916 error ("%Jregister name given for non-register variable '%D'", decl, decl);
917
918 /* Specifying a section attribute on a variable forces it into a
919 non-.bss section, and thus it cannot be common. */
920 if (TREE_CODE (decl) == VAR_DECL
921 && DECL_SECTION_NAME (decl) != NULL_TREE
922 && DECL_INITIAL (decl) == NULL_TREE
923 && DECL_COMMON (decl))
924 DECL_COMMON (decl) = 0;
925
926 /* Variables can't be both common and weak. */
927 if (TREE_CODE (decl) == VAR_DECL && DECL_WEAK (decl))
928 DECL_COMMON (decl) = 0;
929
930 x = gen_rtx_SYMBOL_REF (Pmode, name);
931 SYMBOL_REF_WEAK (x) = DECL_WEAK (decl);
932 SYMBOL_REF_DECL (x) = decl;
933
934 x = gen_rtx_MEM (DECL_MODE (decl), x);
935 if (TREE_CODE (decl) != FUNCTION_DECL)
936 set_mem_attributes (x, decl, 1);
937 SET_DECL_RTL (decl, x);
938
939 /* Optionally set flags or add text to the name to record information
940 such as that it is a function name.
941 If the name is changed, the macro ASM_OUTPUT_LABELREF
942 will have to know how to strip this information. */
943 targetm.encode_section_info (decl, DECL_RTL (decl), true);
944
945 /* Make this function static known to the mudflap runtime. */
946 if (flag_mudflap && TREE_CODE (decl) == VAR_DECL)
947 mudflap_enqueue_decl (decl);
948 }
949
950 /* Make the rtl for variable VAR be volatile.
951 Use this only for static variables. */
952
953 void
954 make_var_volatile (tree var)
955 {
956 if (!MEM_P (DECL_RTL (var)))
957 abort ();
958
959 MEM_VOLATILE_P (DECL_RTL (var)) = 1;
960 }
961 \f
962 /* Output a string of literal assembler code
963 for an `asm' keyword used between functions. */
964
965 void
966 assemble_asm (tree string)
967 {
968 app_enable ();
969
970 if (TREE_CODE (string) == ADDR_EXPR)
971 string = TREE_OPERAND (string, 0);
972
973 fprintf (asm_out_file, "\t%s\n", TREE_STRING_POINTER (string));
974 }
975
976 /* Record an element in the table of global destructors. SYMBOL is
977 a SYMBOL_REF of the function to be called; PRIORITY is a number
978 between 0 and MAX_INIT_PRIORITY. */
979
980 void
981 default_stabs_asm_out_destructor (rtx symbol, int priority ATTRIBUTE_UNUSED)
982 {
983 /* Tell GNU LD that this is part of the static destructor set.
984 This will work for any system that uses stabs, most usefully
985 aout systems. */
986 fprintf (asm_out_file, "%s\"___DTOR_LIST__\",22,0,0,", ASM_STABS_OP);
987 assemble_name (asm_out_file, XSTR (symbol, 0));
988 fputc ('\n', asm_out_file);
989 }
990
991 void
992 default_named_section_asm_out_destructor (rtx symbol, int priority)
993 {
994 const char *section = ".dtors";
995 char buf[16];
996
997 /* ??? This only works reliably with the GNU linker. */
998 if (priority != DEFAULT_INIT_PRIORITY)
999 {
1000 sprintf (buf, ".dtors.%.5u",
1001 /* Invert the numbering so the linker puts us in the proper
1002 order; constructors are run from right to left, and the
1003 linker sorts in increasing order. */
1004 MAX_INIT_PRIORITY - priority);
1005 section = buf;
1006 }
1007
1008 named_section_flags (section, SECTION_WRITE);
1009 assemble_align (POINTER_SIZE);
1010 assemble_integer (symbol, POINTER_SIZE / BITS_PER_UNIT, POINTER_SIZE, 1);
1011 }
1012
1013 #ifdef DTORS_SECTION_ASM_OP
1014 void
1015 dtors_section (void)
1016 {
1017 if (in_section != in_dtors)
1018 {
1019 in_section = in_dtors;
1020 fputs (DTORS_SECTION_ASM_OP, asm_out_file);
1021 fputc ('\n', asm_out_file);
1022 }
1023 }
1024
1025 void
1026 default_dtor_section_asm_out_destructor (rtx symbol,
1027 int priority ATTRIBUTE_UNUSED)
1028 {
1029 dtors_section ();
1030 assemble_align (POINTER_SIZE);
1031 assemble_integer (symbol, POINTER_SIZE / BITS_PER_UNIT, POINTER_SIZE, 1);
1032 }
1033 #endif
1034
1035 /* Likewise for global constructors. */
1036
1037 void
1038 default_stabs_asm_out_constructor (rtx symbol, int priority ATTRIBUTE_UNUSED)
1039 {
1040 /* Tell GNU LD that this is part of the static destructor set.
1041 This will work for any system that uses stabs, most usefully
1042 aout systems. */
1043 fprintf (asm_out_file, "%s\"___CTOR_LIST__\",22,0,0,", ASM_STABS_OP);
1044 assemble_name (asm_out_file, XSTR (symbol, 0));
1045 fputc ('\n', asm_out_file);
1046 }
1047
1048 void
1049 default_named_section_asm_out_constructor (rtx symbol, int priority)
1050 {
1051 const char *section = ".ctors";
1052 char buf[16];
1053
1054 /* ??? This only works reliably with the GNU linker. */
1055 if (priority != DEFAULT_INIT_PRIORITY)
1056 {
1057 sprintf (buf, ".ctors.%.5u",
1058 /* Invert the numbering so the linker puts us in the proper
1059 order; constructors are run from right to left, and the
1060 linker sorts in increasing order. */
1061 MAX_INIT_PRIORITY - priority);
1062 section = buf;
1063 }
1064
1065 named_section_flags (section, SECTION_WRITE);
1066 assemble_align (POINTER_SIZE);
1067 assemble_integer (symbol, POINTER_SIZE / BITS_PER_UNIT, POINTER_SIZE, 1);
1068 }
1069
1070 #ifdef CTORS_SECTION_ASM_OP
1071 void
1072 ctors_section (void)
1073 {
1074 if (in_section != in_ctors)
1075 {
1076 in_section = in_ctors;
1077 fputs (CTORS_SECTION_ASM_OP, asm_out_file);
1078 fputc ('\n', asm_out_file);
1079 }
1080 }
1081
1082 void
1083 default_ctor_section_asm_out_constructor (rtx symbol,
1084 int priority ATTRIBUTE_UNUSED)
1085 {
1086 ctors_section ();
1087 assemble_align (POINTER_SIZE);
1088 assemble_integer (symbol, POINTER_SIZE / BITS_PER_UNIT, POINTER_SIZE, 1);
1089 }
1090 #endif
1091 \f
1092 /* CONSTANT_POOL_BEFORE_FUNCTION may be defined as an expression with
1093 a nonzero value if the constant pool should be output before the
1094 start of the function, or a zero value if the pool should output
1095 after the end of the function. The default is to put it before the
1096 start. */
1097
1098 #ifndef CONSTANT_POOL_BEFORE_FUNCTION
1099 #define CONSTANT_POOL_BEFORE_FUNCTION 1
1100 #endif
1101
1102 /* DECL is an object (either VAR_DECL or FUNCTION_DECL) which is going
1103 to be output to assembler.
1104 Set first_global_object_name and weak_global_object_name as appropriate. */
1105
1106 void
1107 notice_global_symbol (tree decl)
1108 {
1109 const char **type = &first_global_object_name;
1110
1111 if (first_global_object_name
1112 || !TREE_PUBLIC (decl) || DECL_EXTERNAL (decl)
1113 || !DECL_NAME (decl)
1114 || (TREE_CODE (decl) != FUNCTION_DECL
1115 && (TREE_CODE (decl) != VAR_DECL
1116 || (DECL_COMMON (decl)
1117 && (DECL_INITIAL (decl) == 0
1118 || DECL_INITIAL (decl) == error_mark_node))))
1119 || !MEM_P (DECL_RTL (decl)))
1120 return;
1121
1122 /* We win when global object is found, but it is useful to know about weak
1123 symbol as well so we can produce nicer unique names. */
1124 if (DECL_WEAK (decl) || DECL_ONE_ONLY (decl))
1125 type = &weak_global_object_name;
1126
1127 if (!*type)
1128 {
1129 const char *p;
1130 char *name;
1131 rtx decl_rtl = DECL_RTL (decl);
1132
1133 p = targetm.strip_name_encoding (XSTR (XEXP (decl_rtl, 0), 0));
1134 name = xstrdup (p);
1135
1136 *type = name;
1137 }
1138 }
1139
1140 /* Output assembler code for the constant pool of a function and associated
1141 with defining the name of the function. DECL describes the function.
1142 NAME is the function's name. For the constant pool, we use the current
1143 constant pool data. */
1144
1145 void
1146 assemble_start_function (tree decl, const char *fnname)
1147 {
1148 int align;
1149
1150 if (unlikely_text_section_name)
1151 free (unlikely_text_section_name);
1152
1153 unlikely_section_label_printed = false;
1154 unlikely_text_section_name = NULL;
1155
1156 if (unlikely_section_label)
1157 free (unlikely_section_label);
1158 unlikely_section_label = xmalloc ((strlen (fnname) + 18) * sizeof (char));
1159 sprintf (unlikely_section_label, "%s_unlikely_section", fnname);
1160
1161 /* The following code does not need preprocessing in the assembler. */
1162
1163 app_disable ();
1164
1165 if (CONSTANT_POOL_BEFORE_FUNCTION)
1166 output_constant_pool (fnname, decl);
1167
1168 /* Make sure the cold text (code) section is properly aligned. This
1169 is necessary here in the case where the function has both hot and
1170 cold sections, because we don't want to re-set the alignment when the
1171 section switch happens mid-function. We don't need to set the hot
1172 section alignment here, because code further down in this function
1173 sets the alignment for whichever section comes first, and if there
1174 is a hot section it is guaranteed to be first. */
1175
1176 if (flag_reorder_blocks_and_partition)
1177 {
1178 unlikely_text_section ();
1179 assemble_align (FUNCTION_BOUNDARY);
1180 }
1181
1182 resolve_unique_section (decl, 0, flag_function_sections);
1183 function_section (decl);
1184
1185 /* Tell assembler to move to target machine's alignment for functions. */
1186 align = floor_log2 (FUNCTION_BOUNDARY / BITS_PER_UNIT);
1187 if (align < force_align_functions_log)
1188 align = force_align_functions_log;
1189 if (align > 0)
1190 {
1191 ASM_OUTPUT_ALIGN (asm_out_file, align);
1192 }
1193
1194 /* Handle a user-specified function alignment.
1195 Note that we still need to align to FUNCTION_BOUNDARY, as above,
1196 because ASM_OUTPUT_MAX_SKIP_ALIGN might not do any alignment at all. */
1197 if (align_functions_log > align
1198 && cfun->function_frequency != FUNCTION_FREQUENCY_UNLIKELY_EXECUTED)
1199 {
1200 #ifdef ASM_OUTPUT_MAX_SKIP_ALIGN
1201 ASM_OUTPUT_MAX_SKIP_ALIGN (asm_out_file,
1202 align_functions_log, align_functions - 1);
1203 #else
1204 ASM_OUTPUT_ALIGN (asm_out_file, align_functions_log);
1205 #endif
1206 }
1207
1208 #ifdef ASM_OUTPUT_FUNCTION_PREFIX
1209 ASM_OUTPUT_FUNCTION_PREFIX (asm_out_file, fnname);
1210 #endif
1211
1212 (*debug_hooks->begin_function) (decl);
1213
1214 /* Make function name accessible from other files, if appropriate. */
1215
1216 if (TREE_PUBLIC (decl))
1217 {
1218 notice_global_symbol (decl);
1219
1220 globalize_decl (decl);
1221
1222 maybe_assemble_visibility (decl);
1223 }
1224
1225 if (DECL_PRESERVE_P (decl))
1226 targetm.asm_out.mark_decl_preserved (fnname);
1227
1228 /* Do any machine/system dependent processing of the function name. */
1229 #ifdef ASM_DECLARE_FUNCTION_NAME
1230 ASM_DECLARE_FUNCTION_NAME (asm_out_file, fnname, current_function_decl);
1231 #else
1232 /* Standard thing is just output label for the function. */
1233 ASM_OUTPUT_LABEL (asm_out_file, fnname);
1234 #endif /* ASM_DECLARE_FUNCTION_NAME */
1235
1236 if (in_unlikely_text_section ()
1237 && !unlikely_section_label_printed)
1238 {
1239 ASM_OUTPUT_LABEL (asm_out_file, unlikely_section_label);
1240 unlikely_section_label_printed = true;
1241 }
1242 }
1243
1244 /* Output assembler code associated with defining the size of the
1245 function. DECL describes the function. NAME is the function's name. */
1246
1247 void
1248 assemble_end_function (tree decl, const char *fnname)
1249 {
1250 #ifdef ASM_DECLARE_FUNCTION_SIZE
1251 ASM_DECLARE_FUNCTION_SIZE (asm_out_file, fnname, decl);
1252 #endif
1253 if (! CONSTANT_POOL_BEFORE_FUNCTION)
1254 {
1255 output_constant_pool (fnname, decl);
1256 function_section (decl); /* need to switch back */
1257 }
1258 }
1259 \f
1260 /* Assemble code to leave SIZE bytes of zeros. */
1261
1262 void
1263 assemble_zeros (unsigned HOST_WIDE_INT size)
1264 {
1265 /* Do no output if -fsyntax-only. */
1266 if (flag_syntax_only)
1267 return;
1268
1269 #ifdef ASM_NO_SKIP_IN_TEXT
1270 /* The `space' pseudo in the text section outputs nop insns rather than 0s,
1271 so we must output 0s explicitly in the text section. */
1272 if ((ASM_NO_SKIP_IN_TEXT && in_text_section ())
1273 || (ASM_NO_SKIP_IN_TEXT && in_unlikely_text_section ()))
1274 {
1275 unsigned HOST_WIDE_INT i;
1276 for (i = 0; i < size; i++)
1277 assemble_integer (const0_rtx, 1, BITS_PER_UNIT, 1);
1278 }
1279 else
1280 #endif
1281 if (size > 0)
1282 ASM_OUTPUT_SKIP (asm_out_file, size);
1283 }
1284
1285 /* Assemble an alignment pseudo op for an ALIGN-bit boundary. */
1286
1287 void
1288 assemble_align (int align)
1289 {
1290 if (align > BITS_PER_UNIT)
1291 {
1292 ASM_OUTPUT_ALIGN (asm_out_file, floor_log2 (align / BITS_PER_UNIT));
1293 }
1294 }
1295
1296 /* Assemble a string constant with the specified C string as contents. */
1297
1298 void
1299 assemble_string (const char *p, int size)
1300 {
1301 int pos = 0;
1302 int maximum = 2000;
1303
1304 /* If the string is very long, split it up. */
1305
1306 while (pos < size)
1307 {
1308 int thissize = size - pos;
1309 if (thissize > maximum)
1310 thissize = maximum;
1311
1312 ASM_OUTPUT_ASCII (asm_out_file, p, thissize);
1313
1314 pos += thissize;
1315 p += thissize;
1316 }
1317 }
1318
1319 \f
1320 #if defined ASM_OUTPUT_ALIGNED_DECL_LOCAL
1321 #define ASM_EMIT_LOCAL(decl, name, size, rounded) \
1322 ASM_OUTPUT_ALIGNED_DECL_LOCAL (asm_out_file, decl, name, size, DECL_ALIGN (decl))
1323 #else
1324 #if defined ASM_OUTPUT_ALIGNED_LOCAL
1325 #define ASM_EMIT_LOCAL(decl, name, size, rounded) \
1326 ASM_OUTPUT_ALIGNED_LOCAL (asm_out_file, name, size, DECL_ALIGN (decl))
1327 #else
1328 #define ASM_EMIT_LOCAL(decl, name, size, rounded) \
1329 ASM_OUTPUT_LOCAL (asm_out_file, name, size, rounded)
1330 #endif
1331 #endif
1332
1333 #if defined ASM_OUTPUT_ALIGNED_BSS
1334 #define ASM_EMIT_BSS(decl, name, size, rounded) \
1335 ASM_OUTPUT_ALIGNED_BSS (asm_out_file, decl, name, size, DECL_ALIGN (decl))
1336 #else
1337 #if defined ASM_OUTPUT_BSS
1338 #define ASM_EMIT_BSS(decl, name, size, rounded) \
1339 ASM_OUTPUT_BSS (asm_out_file, decl, name, size, rounded)
1340 #else
1341 #undef ASM_EMIT_BSS
1342 #endif
1343 #endif
1344
1345 #if defined ASM_OUTPUT_ALIGNED_DECL_COMMON
1346 #define ASM_EMIT_COMMON(decl, name, size, rounded) \
1347 ASM_OUTPUT_ALIGNED_DECL_COMMON (asm_out_file, decl, name, size, DECL_ALIGN (decl))
1348 #else
1349 #if defined ASM_OUTPUT_ALIGNED_COMMON
1350 #define ASM_EMIT_COMMON(decl, name, size, rounded) \
1351 ASM_OUTPUT_ALIGNED_COMMON (asm_out_file, name, size, DECL_ALIGN (decl))
1352 #else
1353 #define ASM_EMIT_COMMON(decl, name, size, rounded) \
1354 ASM_OUTPUT_COMMON (asm_out_file, name, size, rounded)
1355 #endif
1356 #endif
1357
1358 static bool
1359 asm_emit_uninitialised (tree decl, const char *name,
1360 unsigned HOST_WIDE_INT size ATTRIBUTE_UNUSED,
1361 unsigned HOST_WIDE_INT rounded ATTRIBUTE_UNUSED)
1362 {
1363 enum
1364 {
1365 asm_dest_common,
1366 asm_dest_bss,
1367 asm_dest_local
1368 }
1369 destination = asm_dest_local;
1370
1371 /* ??? We should handle .bss via select_section mechanisms rather than
1372 via special target hooks. That would eliminate this special case. */
1373 if (TREE_PUBLIC (decl))
1374 {
1375 if (!DECL_COMMON (decl))
1376 #ifdef ASM_EMIT_BSS
1377 destination = asm_dest_bss;
1378 #else
1379 return false;
1380 #endif
1381 else
1382 destination = asm_dest_common;
1383 }
1384
1385 if (destination == asm_dest_bss)
1386 globalize_decl (decl);
1387 resolve_unique_section (decl, 0, flag_data_sections);
1388
1389 if (flag_shared_data)
1390 {
1391 switch (destination)
1392 {
1393 #ifdef ASM_OUTPUT_SHARED_BSS
1394 case asm_dest_bss:
1395 ASM_OUTPUT_SHARED_BSS (asm_out_file, decl, name, size, rounded);
1396 return;
1397 #endif
1398 #ifdef ASM_OUTPUT_SHARED_COMMON
1399 case asm_dest_common:
1400 ASM_OUTPUT_SHARED_COMMON (asm_out_file, name, size, rounded);
1401 return;
1402 #endif
1403 #ifdef ASM_OUTPUT_SHARED_LOCAL
1404 case asm_dest_local:
1405 ASM_OUTPUT_SHARED_LOCAL (asm_out_file, name, size, rounded);
1406 return;
1407 #endif
1408 default:
1409 break;
1410 }
1411 }
1412
1413 switch (destination)
1414 {
1415 #ifdef ASM_EMIT_BSS
1416 case asm_dest_bss:
1417 ASM_EMIT_BSS (decl, name, size, rounded);
1418 break;
1419 #endif
1420 case asm_dest_common:
1421 ASM_EMIT_COMMON (decl, name, size, rounded);
1422 break;
1423 case asm_dest_local:
1424 ASM_EMIT_LOCAL (decl, name, size, rounded);
1425 break;
1426 default:
1427 abort ();
1428 }
1429
1430 return true;
1431 }
1432
1433 /* Assemble everything that is needed for a variable or function declaration.
1434 Not used for automatic variables, and not used for function definitions.
1435 Should not be called for variables of incomplete structure type.
1436
1437 TOP_LEVEL is nonzero if this variable has file scope.
1438 AT_END is nonzero if this is the special handling, at end of compilation,
1439 to define things that have had only tentative definitions.
1440 DONT_OUTPUT_DATA if nonzero means don't actually output the
1441 initial value (that will be done by the caller). */
1442
1443 void
1444 assemble_variable (tree decl, int top_level ATTRIBUTE_UNUSED,
1445 int at_end ATTRIBUTE_UNUSED, int dont_output_data)
1446 {
1447 const char *name;
1448 unsigned int align;
1449 int reloc = 0;
1450 rtx decl_rtl;
1451
1452 if (lang_hooks.decls.prepare_assemble_variable)
1453 lang_hooks.decls.prepare_assemble_variable (decl);
1454
1455 last_assemble_variable_decl = 0;
1456
1457 /* Normally no need to say anything here for external references,
1458 since assemble_external is called by the language-specific code
1459 when a declaration is first seen. */
1460
1461 if (DECL_EXTERNAL (decl))
1462 return;
1463
1464 /* Output no assembler code for a function declaration.
1465 Only definitions of functions output anything. */
1466
1467 if (TREE_CODE (decl) == FUNCTION_DECL)
1468 return;
1469
1470 /* Do nothing for global register variables. */
1471 if (DECL_RTL_SET_P (decl) && REG_P (DECL_RTL (decl)))
1472 {
1473 TREE_ASM_WRITTEN (decl) = 1;
1474 return;
1475 }
1476
1477 /* If type was incomplete when the variable was declared,
1478 see if it is complete now. */
1479
1480 if (DECL_SIZE (decl) == 0)
1481 layout_decl (decl, 0);
1482
1483 /* Still incomplete => don't allocate it; treat the tentative defn
1484 (which is what it must have been) as an `extern' reference. */
1485
1486 if (!dont_output_data && DECL_SIZE (decl) == 0)
1487 {
1488 error ("%Jstorage size of `%D' isn't known", decl, decl);
1489 TREE_ASM_WRITTEN (decl) = 1;
1490 return;
1491 }
1492
1493 /* The first declaration of a variable that comes through this function
1494 decides whether it is global (in C, has external linkage)
1495 or local (in C, has internal linkage). So do nothing more
1496 if this function has already run. */
1497
1498 if (TREE_ASM_WRITTEN (decl))
1499 return;
1500
1501 /* Make sure targetm.encode_section_info is invoked before we set
1502 ASM_WRITTEN. */
1503 decl_rtl = DECL_RTL (decl);
1504
1505 TREE_ASM_WRITTEN (decl) = 1;
1506
1507 /* Do no output if -fsyntax-only. */
1508 if (flag_syntax_only)
1509 return;
1510
1511 app_disable ();
1512
1513 if (! dont_output_data
1514 && ! host_integerp (DECL_SIZE_UNIT (decl), 1))
1515 {
1516 error ("%Jsize of variable '%D' is too large", decl, decl);
1517 return;
1518 }
1519
1520 name = XSTR (XEXP (decl_rtl, 0), 0);
1521 if (TREE_PUBLIC (decl) && DECL_NAME (decl))
1522 notice_global_symbol (decl);
1523
1524 /* Compute the alignment of this data. */
1525
1526 align = DECL_ALIGN (decl);
1527
1528 /* In the case for initialing an array whose length isn't specified,
1529 where we have not yet been able to do the layout,
1530 figure out the proper alignment now. */
1531 if (dont_output_data && DECL_SIZE (decl) == 0
1532 && TREE_CODE (TREE_TYPE (decl)) == ARRAY_TYPE)
1533 align = MAX (align, TYPE_ALIGN (TREE_TYPE (TREE_TYPE (decl))));
1534
1535 /* Some object file formats have a maximum alignment which they support.
1536 In particular, a.out format supports a maximum alignment of 4. */
1537 if (align > MAX_OFILE_ALIGNMENT)
1538 {
1539 warning ("%Jalignment of '%D' is greater than maximum object "
1540 "file alignment. Using %d", decl, decl,
1541 MAX_OFILE_ALIGNMENT/BITS_PER_UNIT);
1542 align = MAX_OFILE_ALIGNMENT;
1543 }
1544
1545 /* On some machines, it is good to increase alignment sometimes. */
1546 if (! DECL_USER_ALIGN (decl))
1547 {
1548 #ifdef DATA_ALIGNMENT
1549 align = DATA_ALIGNMENT (TREE_TYPE (decl), align);
1550 #endif
1551 #ifdef CONSTANT_ALIGNMENT
1552 if (DECL_INITIAL (decl) != 0 && DECL_INITIAL (decl) != error_mark_node)
1553 align = CONSTANT_ALIGNMENT (DECL_INITIAL (decl), align);
1554 #endif
1555 }
1556
1557 /* Reset the alignment in case we have made it tighter, so we can benefit
1558 from it in get_pointer_alignment. */
1559 DECL_ALIGN (decl) = align;
1560 set_mem_align (decl_rtl, align);
1561
1562 if (TREE_PUBLIC (decl))
1563 maybe_assemble_visibility (decl);
1564
1565 if (DECL_PRESERVE_P (decl))
1566 targetm.asm_out.mark_decl_preserved (name);
1567
1568 /* Output any data that we will need to use the address of. */
1569 if (DECL_INITIAL (decl) == error_mark_node)
1570 reloc = contains_pointers_p (TREE_TYPE (decl)) ? 3 : 0;
1571 else if (DECL_INITIAL (decl))
1572 {
1573 reloc = compute_reloc_for_constant (DECL_INITIAL (decl));
1574 output_addressed_constants (DECL_INITIAL (decl));
1575 }
1576 resolve_unique_section (decl, reloc, flag_data_sections);
1577
1578 /* Handle uninitialized definitions. */
1579
1580 /* If the decl has been given an explicit section name, then it
1581 isn't common, and shouldn't be handled as such. */
1582 if (DECL_SECTION_NAME (decl) || dont_output_data)
1583 ;
1584 /* We don't implement common thread-local data at present. */
1585 else if (DECL_THREAD_LOCAL (decl))
1586 {
1587 if (DECL_COMMON (decl))
1588 sorry ("thread-local COMMON data not implemented");
1589 }
1590 else if (DECL_INITIAL (decl) == 0
1591 || DECL_INITIAL (decl) == error_mark_node
1592 || (flag_zero_initialized_in_bss
1593 /* Leave constant zeroes in .rodata so they can be shared. */
1594 && !TREE_READONLY (decl)
1595 && initializer_zerop (DECL_INITIAL (decl))))
1596 {
1597 unsigned HOST_WIDE_INT size = tree_low_cst (DECL_SIZE_UNIT (decl), 1);
1598 unsigned HOST_WIDE_INT rounded = size;
1599
1600 /* Don't allocate zero bytes of common,
1601 since that means "undefined external" in the linker. */
1602 if (size == 0)
1603 rounded = 1;
1604
1605 /* Round size up to multiple of BIGGEST_ALIGNMENT bits
1606 so that each uninitialized object starts on such a boundary. */
1607 rounded += (BIGGEST_ALIGNMENT / BITS_PER_UNIT) - 1;
1608 rounded = (rounded / (BIGGEST_ALIGNMENT / BITS_PER_UNIT)
1609 * (BIGGEST_ALIGNMENT / BITS_PER_UNIT));
1610
1611 #if !defined(ASM_OUTPUT_ALIGNED_COMMON) && !defined(ASM_OUTPUT_ALIGNED_DECL_COMMON) && !defined(ASM_OUTPUT_ALIGNED_BSS)
1612 if ((unsigned HOST_WIDE_INT) DECL_ALIGN (decl) / BITS_PER_UNIT > rounded)
1613 warning ("%Jrequested alignment for '%D' is greater than "
1614 "implemented alignment of %d", decl, decl, rounded);
1615 #endif
1616
1617 /* If the target cannot output uninitialized but not common global data
1618 in .bss, then we have to use .data, so fall through. */
1619 if (asm_emit_uninitialised (decl, name, size, rounded))
1620 return;
1621 }
1622
1623 /* Handle initialized definitions.
1624 Also handle uninitialized global definitions if -fno-common and the
1625 target doesn't support ASM_OUTPUT_BSS. */
1626
1627 /* First make the assembler name(s) global if appropriate. */
1628 if (TREE_PUBLIC (decl) && DECL_NAME (decl))
1629 globalize_decl (decl);
1630
1631 /* Switch to the appropriate section. */
1632 variable_section (decl, reloc);
1633
1634 /* dbxout.c needs to know this. */
1635 if (in_text_section () || in_unlikely_text_section ())
1636 DECL_IN_TEXT_SECTION (decl) = 1;
1637
1638 /* Output the alignment of this data. */
1639 if (align > BITS_PER_UNIT)
1640 {
1641 ASM_OUTPUT_ALIGN (asm_out_file,
1642 floor_log2 (DECL_ALIGN (decl) / BITS_PER_UNIT));
1643 }
1644
1645 /* Do any machine/system dependent processing of the object. */
1646 #ifdef ASM_DECLARE_OBJECT_NAME
1647 last_assemble_variable_decl = decl;
1648 ASM_DECLARE_OBJECT_NAME (asm_out_file, name, decl);
1649 #else
1650 /* Standard thing is just output label for the object. */
1651 ASM_OUTPUT_LABEL (asm_out_file, name);
1652 #endif /* ASM_DECLARE_OBJECT_NAME */
1653
1654 if (!dont_output_data)
1655 {
1656 if (DECL_INITIAL (decl)
1657 && DECL_INITIAL (decl) != error_mark_node
1658 && !initializer_zerop (DECL_INITIAL (decl)))
1659 /* Output the actual data. */
1660 output_constant (DECL_INITIAL (decl),
1661 tree_low_cst (DECL_SIZE_UNIT (decl), 1),
1662 align);
1663 else
1664 /* Leave space for it. */
1665 assemble_zeros (tree_low_cst (DECL_SIZE_UNIT (decl), 1));
1666 }
1667 }
1668
1669 /* Return 1 if type TYPE contains any pointers. */
1670
1671 static int
1672 contains_pointers_p (tree type)
1673 {
1674 switch (TREE_CODE (type))
1675 {
1676 case POINTER_TYPE:
1677 case REFERENCE_TYPE:
1678 /* I'm not sure whether OFFSET_TYPE needs this treatment,
1679 so I'll play safe and return 1. */
1680 case OFFSET_TYPE:
1681 return 1;
1682
1683 case RECORD_TYPE:
1684 case UNION_TYPE:
1685 case QUAL_UNION_TYPE:
1686 {
1687 tree fields;
1688 /* For a type that has fields, see if the fields have pointers. */
1689 for (fields = TYPE_FIELDS (type); fields; fields = TREE_CHAIN (fields))
1690 if (TREE_CODE (fields) == FIELD_DECL
1691 && contains_pointers_p (TREE_TYPE (fields)))
1692 return 1;
1693 return 0;
1694 }
1695
1696 case ARRAY_TYPE:
1697 /* An array type contains pointers if its element type does. */
1698 return contains_pointers_p (TREE_TYPE (type));
1699
1700 default:
1701 return 0;
1702 }
1703 }
1704
1705 #ifdef ASM_OUTPUT_EXTERNAL
1706 /* True if DECL is a function decl for which no out-of-line copy exists.
1707 It is assumed that DECL's assembler name has been set. */
1708
1709 static bool
1710 incorporeal_function_p (tree decl)
1711 {
1712 if (TREE_CODE (decl) == FUNCTION_DECL && DECL_BUILT_IN (decl))
1713 {
1714 const char *name;
1715
1716 if (DECL_BUILT_IN_CLASS (decl) == BUILT_IN_NORMAL
1717 && DECL_FUNCTION_CODE (decl) == BUILT_IN_ALLOCA)
1718 return true;
1719
1720 name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
1721 if (strncmp (name, "__builtin_", strlen ("__builtin_")) == 0)
1722 return true;
1723 }
1724 return false;
1725 }
1726 #endif
1727
1728 /* Output something to declare an external symbol to the assembler.
1729 (Most assemblers don't need this, so we normally output nothing.)
1730 Do nothing if DECL is not external. */
1731
1732 void
1733 assemble_external (tree decl ATTRIBUTE_UNUSED)
1734 {
1735 /* Because most platforms do not define ASM_OUTPUT_EXTERNAL, the
1736 main body of this code is only rarely exercised. To provide some
1737 testing, on all platforms, we make sure that the ASM_OUT_FILE is
1738 open. If it's not, we should not be calling this function. */
1739 if (!asm_out_file)
1740 abort ();
1741
1742 #ifdef ASM_OUTPUT_EXTERNAL
1743 if (DECL_P (decl) && DECL_EXTERNAL (decl) && TREE_PUBLIC (decl))
1744 {
1745 rtx rtl = DECL_RTL (decl);
1746
1747 if (MEM_P (rtl) && GET_CODE (XEXP (rtl, 0)) == SYMBOL_REF
1748 && !SYMBOL_REF_USED (XEXP (rtl, 0))
1749 && !incorporeal_function_p (decl))
1750 {
1751 /* Some systems do require some output. */
1752 SYMBOL_REF_USED (XEXP (rtl, 0)) = 1;
1753 ASM_OUTPUT_EXTERNAL (asm_out_file, decl, XSTR (XEXP (rtl, 0), 0));
1754 }
1755 }
1756 #endif
1757 }
1758
1759 /* Similar, for calling a library function FUN. */
1760
1761 void
1762 assemble_external_libcall (rtx fun)
1763 {
1764 /* Declare library function name external when first used, if nec. */
1765 if (! SYMBOL_REF_USED (fun))
1766 {
1767 SYMBOL_REF_USED (fun) = 1;
1768 targetm.asm_out.external_libcall (fun);
1769 }
1770 }
1771
1772 /* Assemble a label named NAME. */
1773
1774 void
1775 assemble_label (const char *name)
1776 {
1777 ASM_OUTPUT_LABEL (asm_out_file, name);
1778 }
1779
1780 /* Set the symbol_referenced flag for ID. */
1781 void
1782 mark_referenced (tree id)
1783 {
1784 TREE_SYMBOL_REFERENCED (id) = 1;
1785 }
1786
1787 /* Set the symbol_referenced flag for DECL and notify callgraph. */
1788 void
1789 mark_decl_referenced (tree decl)
1790 {
1791 if (TREE_CODE (decl) == FUNCTION_DECL)
1792 cgraph_mark_needed_node (cgraph_node (decl));
1793 else if (TREE_CODE (decl) == VAR_DECL)
1794 cgraph_varpool_mark_needed_node (cgraph_varpool_node (decl));
1795 /* else do nothing - we can get various sorts of CST nodes here,
1796 which do not need to be marked. */
1797 }
1798
1799 /* Output to FILE a reference to the assembler name of a C-level name NAME.
1800 If NAME starts with a *, the rest of NAME is output verbatim.
1801 Otherwise NAME is transformed in an implementation-defined way
1802 (usually by the addition of an underscore).
1803 Many macros in the tm file are defined to call this function. */
1804
1805 void
1806 assemble_name (FILE *file, const char *name)
1807 {
1808 const char *real_name;
1809 tree id;
1810
1811 real_name = targetm.strip_name_encoding (name);
1812
1813 id = maybe_get_identifier (real_name);
1814 if (id)
1815 mark_referenced (id);
1816
1817 if (name[0] == '*')
1818 fputs (&name[1], file);
1819 else
1820 ASM_OUTPUT_LABELREF (file, name);
1821 }
1822
1823 /* Allocate SIZE bytes writable static space with a gensym name
1824 and return an RTX to refer to its address. */
1825
1826 rtx
1827 assemble_static_space (unsigned HOST_WIDE_INT size)
1828 {
1829 char name[12];
1830 const char *namestring;
1831 rtx x;
1832
1833 #if 0
1834 if (flag_shared_data)
1835 data_section ();
1836 #endif
1837
1838 ASM_GENERATE_INTERNAL_LABEL (name, "LF", const_labelno);
1839 ++const_labelno;
1840 namestring = ggc_strdup (name);
1841
1842 x = gen_rtx_SYMBOL_REF (Pmode, namestring);
1843 SYMBOL_REF_FLAGS (x) = SYMBOL_FLAG_LOCAL;
1844
1845 #ifdef ASM_OUTPUT_ALIGNED_DECL_LOCAL
1846 ASM_OUTPUT_ALIGNED_DECL_LOCAL (asm_out_file, NULL_TREE, name, size,
1847 BIGGEST_ALIGNMENT);
1848 #else
1849 #ifdef ASM_OUTPUT_ALIGNED_LOCAL
1850 ASM_OUTPUT_ALIGNED_LOCAL (asm_out_file, name, size, BIGGEST_ALIGNMENT);
1851 #else
1852 {
1853 /* Round size up to multiple of BIGGEST_ALIGNMENT bits
1854 so that each uninitialized object starts on such a boundary. */
1855 /* Variable `rounded' might or might not be used in ASM_OUTPUT_LOCAL. */
1856 unsigned HOST_WIDE_INT rounded ATTRIBUTE_UNUSED
1857 = ((size + (BIGGEST_ALIGNMENT / BITS_PER_UNIT) - 1)
1858 / (BIGGEST_ALIGNMENT / BITS_PER_UNIT)
1859 * (BIGGEST_ALIGNMENT / BITS_PER_UNIT));
1860 ASM_OUTPUT_LOCAL (asm_out_file, name, size, rounded);
1861 }
1862 #endif
1863 #endif
1864 return x;
1865 }
1866
1867 /* Assemble the static constant template for function entry trampolines.
1868 This is done at most once per compilation.
1869 Returns an RTX for the address of the template. */
1870
1871 static GTY(()) rtx initial_trampoline;
1872
1873 #ifdef TRAMPOLINE_TEMPLATE
1874 rtx
1875 assemble_trampoline_template (void)
1876 {
1877 char label[256];
1878 const char *name;
1879 int align;
1880 rtx symbol;
1881
1882 if (initial_trampoline)
1883 return initial_trampoline;
1884
1885 /* By default, put trampoline templates in read-only data section. */
1886
1887 #ifdef TRAMPOLINE_SECTION
1888 TRAMPOLINE_SECTION ();
1889 #else
1890 readonly_data_section ();
1891 #endif
1892
1893 /* Write the assembler code to define one. */
1894 align = floor_log2 (TRAMPOLINE_ALIGNMENT / BITS_PER_UNIT);
1895 if (align > 0)
1896 {
1897 ASM_OUTPUT_ALIGN (asm_out_file, align);
1898 }
1899
1900 targetm.asm_out.internal_label (asm_out_file, "LTRAMP", 0);
1901 TRAMPOLINE_TEMPLATE (asm_out_file);
1902
1903 /* Record the rtl to refer to it. */
1904 ASM_GENERATE_INTERNAL_LABEL (label, "LTRAMP", 0);
1905 name = ggc_strdup (label);
1906 symbol = gen_rtx_SYMBOL_REF (Pmode, name);
1907 SYMBOL_REF_FLAGS (symbol) = SYMBOL_FLAG_LOCAL;
1908
1909 initial_trampoline = gen_rtx_MEM (BLKmode, symbol);
1910 set_mem_align (initial_trampoline, TRAMPOLINE_ALIGNMENT);
1911
1912 return initial_trampoline;
1913 }
1914 #endif
1915 \f
1916 /* A and B are either alignments or offsets. Return the minimum alignment
1917 that may be assumed after adding the two together. */
1918
1919 static inline unsigned
1920 min_align (unsigned int a, unsigned int b)
1921 {
1922 return (a | b) & -(a | b);
1923 }
1924
1925 /* Return the assembler directive for creating a given kind of integer
1926 object. SIZE is the number of bytes in the object and ALIGNED_P
1927 indicates whether it is known to be aligned. Return NULL if the
1928 assembly dialect has no such directive.
1929
1930 The returned string should be printed at the start of a new line and
1931 be followed immediately by the object's initial value. */
1932
1933 const char *
1934 integer_asm_op (int size, int aligned_p)
1935 {
1936 struct asm_int_op *ops;
1937
1938 if (aligned_p)
1939 ops = &targetm.asm_out.aligned_op;
1940 else
1941 ops = &targetm.asm_out.unaligned_op;
1942
1943 switch (size)
1944 {
1945 case 1:
1946 return targetm.asm_out.byte_op;
1947 case 2:
1948 return ops->hi;
1949 case 4:
1950 return ops->si;
1951 case 8:
1952 return ops->di;
1953 case 16:
1954 return ops->ti;
1955 default:
1956 return NULL;
1957 }
1958 }
1959
1960 /* Use directive OP to assemble an integer object X. Print OP at the
1961 start of the line, followed immediately by the value of X. */
1962
1963 void
1964 assemble_integer_with_op (const char *op, rtx x)
1965 {
1966 fputs (op, asm_out_file);
1967 output_addr_const (asm_out_file, x);
1968 fputc ('\n', asm_out_file);
1969 }
1970
1971 /* The default implementation of the asm_out.integer target hook. */
1972
1973 bool
1974 default_assemble_integer (rtx x ATTRIBUTE_UNUSED,
1975 unsigned int size ATTRIBUTE_UNUSED,
1976 int aligned_p ATTRIBUTE_UNUSED)
1977 {
1978 const char *op = integer_asm_op (size, aligned_p);
1979 return op && (assemble_integer_with_op (op, x), true);
1980 }
1981
1982 /* Assemble the integer constant X into an object of SIZE bytes. ALIGN is
1983 the alignment of the integer in bits. Return 1 if we were able to output
1984 the constant, otherwise 0. If FORCE is nonzero, abort if we can't output
1985 the constant. */
1986
1987 bool
1988 assemble_integer (rtx x, unsigned int size, unsigned int align, int force)
1989 {
1990 int aligned_p;
1991
1992 aligned_p = (align >= MIN (size * BITS_PER_UNIT, BIGGEST_ALIGNMENT));
1993
1994 /* See if the target hook can handle this kind of object. */
1995 if (targetm.asm_out.integer (x, size, aligned_p))
1996 return true;
1997
1998 /* If the object is a multi-byte one, try splitting it up. Split
1999 it into words it if is multi-word, otherwise split it into bytes. */
2000 if (size > 1)
2001 {
2002 enum machine_mode omode, imode;
2003 unsigned int subalign;
2004 unsigned int subsize, i;
2005
2006 subsize = size > UNITS_PER_WORD? UNITS_PER_WORD : 1;
2007 subalign = MIN (align, subsize * BITS_PER_UNIT);
2008 omode = mode_for_size (subsize * BITS_PER_UNIT, MODE_INT, 0);
2009 imode = mode_for_size (size * BITS_PER_UNIT, MODE_INT, 0);
2010
2011 for (i = 0; i < size; i += subsize)
2012 {
2013 rtx partial = simplify_subreg (omode, x, imode, i);
2014 if (!partial || !assemble_integer (partial, subsize, subalign, 0))
2015 break;
2016 }
2017 if (i == size)
2018 return true;
2019
2020 /* If we've printed some of it, but not all of it, there's no going
2021 back now. */
2022 if (i > 0)
2023 abort ();
2024 }
2025
2026 if (force)
2027 abort ();
2028
2029 return false;
2030 }
2031 \f
2032 void
2033 assemble_real (REAL_VALUE_TYPE d, enum machine_mode mode, unsigned int align)
2034 {
2035 long data[4];
2036 int i;
2037 int bitsize, nelts, nunits, units_per;
2038
2039 /* This is hairy. We have a quantity of known size. real_to_target
2040 will put it into an array of *host* longs, 32 bits per element
2041 (even if long is more than 32 bits). We need to determine the
2042 number of array elements that are occupied (nelts) and the number
2043 of *target* min-addressable units that will be occupied in the
2044 object file (nunits). We cannot assume that 32 divides the
2045 mode's bitsize (size * BITS_PER_UNIT) evenly.
2046
2047 size * BITS_PER_UNIT is used here to make sure that padding bits
2048 (which might appear at either end of the value; real_to_target
2049 will include the padding bits in its output array) are included. */
2050
2051 nunits = GET_MODE_SIZE (mode);
2052 bitsize = nunits * BITS_PER_UNIT;
2053 nelts = CEIL (bitsize, 32);
2054 units_per = 32 / BITS_PER_UNIT;
2055
2056 real_to_target (data, &d, mode);
2057
2058 /* Put out the first word with the specified alignment. */
2059 assemble_integer (GEN_INT (data[0]), MIN (nunits, units_per), align, 1);
2060 nunits -= units_per;
2061
2062 /* Subsequent words need only 32-bit alignment. */
2063 align = min_align (align, 32);
2064
2065 for (i = 1; i < nelts; i++)
2066 {
2067 assemble_integer (GEN_INT (data[i]), MIN (nunits, units_per), align, 1);
2068 nunits -= units_per;
2069 }
2070 }
2071 \f
2072 /* Given an expression EXP with a constant value,
2073 reduce it to the sum of an assembler symbol and an integer.
2074 Store them both in the structure *VALUE.
2075 Abort if EXP does not reduce. */
2076
2077 struct addr_const GTY(())
2078 {
2079 rtx base;
2080 HOST_WIDE_INT offset;
2081 };
2082
2083 static void
2084 decode_addr_const (tree exp, struct addr_const *value)
2085 {
2086 tree target = TREE_OPERAND (exp, 0);
2087 int offset = 0;
2088 rtx x;
2089
2090 while (1)
2091 {
2092 if (TREE_CODE (target) == COMPONENT_REF
2093 && host_integerp (byte_position (TREE_OPERAND (target, 1)), 0))
2094
2095 {
2096 offset += int_byte_position (TREE_OPERAND (target, 1));
2097 target = TREE_OPERAND (target, 0);
2098 }
2099 else if (TREE_CODE (target) == ARRAY_REF
2100 || TREE_CODE (target) == ARRAY_RANGE_REF)
2101 {
2102 offset += (tree_low_cst (TYPE_SIZE_UNIT (TREE_TYPE (target)), 1)
2103 * tree_low_cst (TREE_OPERAND (target, 1), 0));
2104 target = TREE_OPERAND (target, 0);
2105 }
2106 else
2107 break;
2108 }
2109
2110 switch (TREE_CODE (target))
2111 {
2112 case VAR_DECL:
2113 case FUNCTION_DECL:
2114 x = DECL_RTL (target);
2115 break;
2116
2117 case LABEL_DECL:
2118 x = gen_rtx_MEM (FUNCTION_MODE,
2119 gen_rtx_LABEL_REF (VOIDmode, force_label_rtx (target)));
2120 break;
2121
2122 case REAL_CST:
2123 case STRING_CST:
2124 case COMPLEX_CST:
2125 case CONSTRUCTOR:
2126 case INTEGER_CST:
2127 x = output_constant_def (target, 1);
2128 break;
2129
2130 default:
2131 abort ();
2132 }
2133
2134 if (!MEM_P (x))
2135 abort ();
2136 x = XEXP (x, 0);
2137
2138 value->base = x;
2139 value->offset = offset;
2140 }
2141 \f
2142 /* Uniquize all constants that appear in memory.
2143 Each constant in memory thus far output is recorded
2144 in `const_desc_table'. */
2145
2146 struct constant_descriptor_tree GTY(())
2147 {
2148 /* A MEM for the constant. */
2149 rtx rtl;
2150
2151 /* The value of the constant. */
2152 tree value;
2153 };
2154
2155 static GTY((param_is (struct constant_descriptor_tree)))
2156 htab_t const_desc_htab;
2157
2158 static struct constant_descriptor_tree * build_constant_desc (tree);
2159 static void maybe_output_constant_def_contents (struct constant_descriptor_tree *, int);
2160
2161 /* Compute a hash code for a constant expression. */
2162
2163 static hashval_t
2164 const_desc_hash (const void *ptr)
2165 {
2166 return const_hash_1 (((struct constant_descriptor_tree *)ptr)->value);
2167 }
2168
2169 static hashval_t
2170 const_hash_1 (const tree exp)
2171 {
2172 const char *p;
2173 hashval_t hi;
2174 int len, i;
2175 enum tree_code code = TREE_CODE (exp);
2176
2177 /* Either set P and LEN to the address and len of something to hash and
2178 exit the switch or return a value. */
2179
2180 switch (code)
2181 {
2182 case INTEGER_CST:
2183 p = (char *) &TREE_INT_CST (exp);
2184 len = sizeof TREE_INT_CST (exp);
2185 break;
2186
2187 case REAL_CST:
2188 return real_hash (TREE_REAL_CST_PTR (exp));
2189
2190 case STRING_CST:
2191 p = TREE_STRING_POINTER (exp);
2192 len = TREE_STRING_LENGTH (exp);
2193 break;
2194
2195 case COMPLEX_CST:
2196 return (const_hash_1 (TREE_REALPART (exp)) * 5
2197 + const_hash_1 (TREE_IMAGPART (exp)));
2198
2199 case CONSTRUCTOR:
2200 if (TREE_CODE (TREE_TYPE (exp)) == SET_TYPE)
2201 {
2202 char *tmp;
2203
2204 len = int_size_in_bytes (TREE_TYPE (exp));
2205 tmp = alloca (len);
2206 get_set_constructor_bytes (exp, (unsigned char *) tmp, len);
2207 p = tmp;
2208 break;
2209 }
2210 else
2211 {
2212 tree link;
2213
2214 hi = 5 + int_size_in_bytes (TREE_TYPE (exp));
2215
2216 for (link = CONSTRUCTOR_ELTS (exp); link; link = TREE_CHAIN (link))
2217 if (TREE_VALUE (link))
2218 hi = hi * 603 + const_hash_1 (TREE_VALUE (link));
2219
2220 return hi;
2221 }
2222
2223 case ADDR_EXPR:
2224 case FDESC_EXPR:
2225 {
2226 struct addr_const value;
2227
2228 decode_addr_const (exp, &value);
2229 if (GET_CODE (value.base) == SYMBOL_REF)
2230 {
2231 /* Don't hash the address of the SYMBOL_REF;
2232 only use the offset and the symbol name. */
2233 hi = value.offset;
2234 p = XSTR (value.base, 0);
2235 for (i = 0; p[i] != 0; i++)
2236 hi = ((hi * 613) + (unsigned) (p[i]));
2237 }
2238 else if (GET_CODE (value.base) == LABEL_REF)
2239 hi = value.offset + CODE_LABEL_NUMBER (XEXP (value.base, 0)) * 13;
2240 else
2241 abort ();
2242 }
2243 return hi;
2244
2245 case PLUS_EXPR:
2246 case MINUS_EXPR:
2247 return (const_hash_1 (TREE_OPERAND (exp, 0)) * 9
2248 + const_hash_1 (TREE_OPERAND (exp, 1)));
2249
2250 case NOP_EXPR:
2251 case CONVERT_EXPR:
2252 case NON_LVALUE_EXPR:
2253 return const_hash_1 (TREE_OPERAND (exp, 0)) * 7 + 2;
2254
2255 default:
2256 /* A language specific constant. Just hash the code. */
2257 return code;
2258 }
2259
2260 /* Compute hashing function. */
2261 hi = len;
2262 for (i = 0; i < len; i++)
2263 hi = ((hi * 613) + (unsigned) (p[i]));
2264
2265 return hi;
2266 }
2267
2268 /* Wrapper of compare_constant, for the htab interface. */
2269 static int
2270 const_desc_eq (const void *p1, const void *p2)
2271 {
2272 return compare_constant (((struct constant_descriptor_tree *)p1)->value,
2273 ((struct constant_descriptor_tree *)p2)->value);
2274 }
2275
2276 /* Compare t1 and t2, and return 1 only if they are known to result in
2277 the same bit pattern on output. */
2278
2279 static int
2280 compare_constant (const tree t1, const tree t2)
2281 {
2282 enum tree_code typecode;
2283
2284 if (t1 == NULL_TREE)
2285 return t2 == NULL_TREE;
2286 if (t2 == NULL_TREE)
2287 return 0;
2288
2289 if (TREE_CODE (t1) != TREE_CODE (t2))
2290 return 0;
2291
2292 switch (TREE_CODE (t1))
2293 {
2294 case INTEGER_CST:
2295 /* Integer constants are the same only if the same width of type. */
2296 if (TYPE_PRECISION (TREE_TYPE (t1)) != TYPE_PRECISION (TREE_TYPE (t2)))
2297 return 0;
2298 return tree_int_cst_equal (t1, t2);
2299
2300 case REAL_CST:
2301 /* Real constants are the same only if the same width of type. */
2302 if (TYPE_PRECISION (TREE_TYPE (t1)) != TYPE_PRECISION (TREE_TYPE (t2)))
2303 return 0;
2304
2305 return REAL_VALUES_IDENTICAL (TREE_REAL_CST (t1), TREE_REAL_CST (t2));
2306
2307 case STRING_CST:
2308 if (TYPE_MODE (TREE_TYPE (t1)) != TYPE_MODE (TREE_TYPE (t2)))
2309 return 0;
2310
2311 return (TREE_STRING_LENGTH (t1) == TREE_STRING_LENGTH (t2)
2312 && ! memcmp (TREE_STRING_POINTER (t1), TREE_STRING_POINTER (t2),
2313 TREE_STRING_LENGTH (t1)));
2314
2315 case COMPLEX_CST:
2316 return (compare_constant (TREE_REALPART (t1), TREE_REALPART (t2))
2317 && compare_constant (TREE_IMAGPART (t1), TREE_IMAGPART (t2)));
2318
2319 case CONSTRUCTOR:
2320 typecode = TREE_CODE (TREE_TYPE (t1));
2321 if (typecode != TREE_CODE (TREE_TYPE (t2)))
2322 return 0;
2323
2324 if (typecode == SET_TYPE)
2325 {
2326 int len = int_size_in_bytes (TREE_TYPE (t2));
2327 unsigned char *tmp1, *tmp2;
2328
2329 if (int_size_in_bytes (TREE_TYPE (t1)) != len)
2330 return 0;
2331
2332 tmp1 = alloca (len);
2333 tmp2 = alloca (len);
2334
2335 if (get_set_constructor_bytes (t1, tmp1, len) != NULL_TREE)
2336 return 0;
2337 if (get_set_constructor_bytes (t2, tmp2, len) != NULL_TREE)
2338 return 0;
2339
2340 return memcmp (tmp1, tmp2, len) == 0;
2341 }
2342 else
2343 {
2344 tree l1, l2;
2345
2346 if (typecode == ARRAY_TYPE)
2347 {
2348 HOST_WIDE_INT size_1 = int_size_in_bytes (TREE_TYPE (t1));
2349 /* For arrays, check that the sizes all match. */
2350 if (TYPE_MODE (TREE_TYPE (t1)) != TYPE_MODE (TREE_TYPE (t2))
2351 || size_1 == -1
2352 || size_1 != int_size_in_bytes (TREE_TYPE (t2)))
2353 return 0;
2354 }
2355 else
2356 {
2357 /* For record and union constructors, require exact type
2358 equality. */
2359 if (TREE_TYPE (t1) != TREE_TYPE (t2))
2360 return 0;
2361 }
2362
2363 for (l1 = CONSTRUCTOR_ELTS (t1), l2 = CONSTRUCTOR_ELTS (t2);
2364 l1 && l2;
2365 l1 = TREE_CHAIN (l1), l2 = TREE_CHAIN (l2))
2366 {
2367 /* Check that each value is the same... */
2368 if (! compare_constant (TREE_VALUE (l1), TREE_VALUE (l2)))
2369 return 0;
2370 /* ... and that they apply to the same fields! */
2371 if (typecode == ARRAY_TYPE)
2372 {
2373 if (! compare_constant (TREE_PURPOSE (l1),
2374 TREE_PURPOSE (l2)))
2375 return 0;
2376 }
2377 else
2378 {
2379 if (TREE_PURPOSE (l1) != TREE_PURPOSE (l2))
2380 return 0;
2381 }
2382 }
2383
2384 return l1 == NULL_TREE && l2 == NULL_TREE;
2385 }
2386
2387 case ADDR_EXPR:
2388 case FDESC_EXPR:
2389 {
2390 struct addr_const value1, value2;
2391
2392 decode_addr_const (t1, &value1);
2393 decode_addr_const (t2, &value2);
2394 return (value1.offset == value2.offset
2395 && strcmp (XSTR (value1.base, 0), XSTR (value2.base, 0)) == 0);
2396 }
2397
2398 case PLUS_EXPR:
2399 case MINUS_EXPR:
2400 case RANGE_EXPR:
2401 return (compare_constant (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0))
2402 && compare_constant(TREE_OPERAND (t1, 1), TREE_OPERAND (t2, 1)));
2403
2404 case NOP_EXPR:
2405 case CONVERT_EXPR:
2406 case NON_LVALUE_EXPR:
2407 case VIEW_CONVERT_EXPR:
2408 return compare_constant (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
2409
2410 default:
2411 {
2412 tree nt1, nt2;
2413 nt1 = lang_hooks.expand_constant (t1);
2414 nt2 = lang_hooks.expand_constant (t2);
2415 if (nt1 != t1 || nt2 != t2)
2416 return compare_constant (nt1, nt2);
2417 else
2418 return 0;
2419 }
2420 }
2421
2422 /* Should not get here. */
2423 abort ();
2424 }
2425 \f
2426 /* Make a copy of the whole tree structure for a constant. This
2427 handles the same types of nodes that compare_constant handles. */
2428
2429 static tree
2430 copy_constant (tree exp)
2431 {
2432 switch (TREE_CODE (exp))
2433 {
2434 case ADDR_EXPR:
2435 /* For ADDR_EXPR, we do not want to copy the decl whose address
2436 is requested. We do want to copy constants though. */
2437 if (TREE_CODE_CLASS (TREE_CODE (TREE_OPERAND (exp, 0))) == 'c')
2438 return build1 (TREE_CODE (exp), TREE_TYPE (exp),
2439 copy_constant (TREE_OPERAND (exp, 0)));
2440 else
2441 return copy_node (exp);
2442
2443 case INTEGER_CST:
2444 case REAL_CST:
2445 case STRING_CST:
2446 return copy_node (exp);
2447
2448 case COMPLEX_CST:
2449 return build_complex (TREE_TYPE (exp),
2450 copy_constant (TREE_REALPART (exp)),
2451 copy_constant (TREE_IMAGPART (exp)));
2452
2453 case PLUS_EXPR:
2454 case MINUS_EXPR:
2455 return build2 (TREE_CODE (exp), TREE_TYPE (exp),
2456 copy_constant (TREE_OPERAND (exp, 0)),
2457 copy_constant (TREE_OPERAND (exp, 1)));
2458
2459 case NOP_EXPR:
2460 case CONVERT_EXPR:
2461 case NON_LVALUE_EXPR:
2462 case VIEW_CONVERT_EXPR:
2463 return build1 (TREE_CODE (exp), TREE_TYPE (exp),
2464 copy_constant (TREE_OPERAND (exp, 0)));
2465
2466 case CONSTRUCTOR:
2467 {
2468 tree copy = copy_node (exp);
2469 tree list = copy_list (CONSTRUCTOR_ELTS (exp));
2470 tree tail;
2471
2472 CONSTRUCTOR_ELTS (copy) = list;
2473 for (tail = list; tail; tail = TREE_CHAIN (tail))
2474 TREE_VALUE (tail) = copy_constant (TREE_VALUE (tail));
2475 if (TREE_CODE (TREE_TYPE (exp)) == SET_TYPE)
2476 for (tail = list; tail; tail = TREE_CHAIN (tail))
2477 TREE_PURPOSE (tail) = copy_constant (TREE_PURPOSE (tail));
2478
2479 return copy;
2480 }
2481
2482 default:
2483 {
2484 tree t;
2485 t = lang_hooks.expand_constant (exp);
2486 if (t != exp)
2487 return copy_constant (t);
2488 else
2489 abort ();
2490 }
2491 }
2492 }
2493 \f
2494 /* Subroutine of output_constant_def:
2495 No constant equal to EXP is known to have been output.
2496 Make a constant descriptor to enter EXP in the hash table.
2497 Assign the label number and construct RTL to refer to the
2498 constant's location in memory.
2499 Caller is responsible for updating the hash table. */
2500
2501 static struct constant_descriptor_tree *
2502 build_constant_desc (tree exp)
2503 {
2504 rtx symbol;
2505 rtx rtl;
2506 char label[256];
2507 int labelno;
2508 struct constant_descriptor_tree *desc;
2509
2510 desc = ggc_alloc (sizeof (*desc));
2511 desc->value = copy_constant (exp);
2512
2513 /* Propagate marked-ness to copied constant. */
2514 if (flag_mudflap && mf_marked_p (exp))
2515 mf_mark (desc->value);
2516
2517 /* Create a string containing the label name, in LABEL. */
2518 labelno = const_labelno++;
2519 ASM_GENERATE_INTERNAL_LABEL (label, "LC", labelno);
2520
2521 /* We have a symbol name; construct the SYMBOL_REF and the MEM. */
2522 symbol = gen_rtx_SYMBOL_REF (Pmode, ggc_strdup (label));
2523 SYMBOL_REF_FLAGS (symbol) = SYMBOL_FLAG_LOCAL;
2524 SYMBOL_REF_DECL (symbol) = desc->value;
2525 TREE_CONSTANT_POOL_ADDRESS_P (symbol) = 1;
2526
2527 rtl = gen_rtx_MEM (TYPE_MODE (TREE_TYPE (exp)), symbol);
2528 set_mem_attributes (rtl, exp, 1);
2529 set_mem_alias_set (rtl, 0);
2530 set_mem_alias_set (rtl, const_alias_set);
2531
2532 /* Set flags or add text to the name to record information, such as
2533 that it is a local symbol. If the name is changed, the macro
2534 ASM_OUTPUT_LABELREF will have to know how to strip this
2535 information. This call might invalidate our local variable
2536 SYMBOL; we can't use it afterward. */
2537
2538 targetm.encode_section_info (exp, rtl, true);
2539
2540 desc->rtl = rtl;
2541
2542 return desc;
2543 }
2544
2545 /* Return an rtx representing a reference to constant data in memory
2546 for the constant expression EXP.
2547
2548 If assembler code for such a constant has already been output,
2549 return an rtx to refer to it.
2550 Otherwise, output such a constant in memory
2551 and generate an rtx for it.
2552
2553 If DEFER is nonzero, this constant can be deferred and output only
2554 if referenced in the function after all optimizations.
2555
2556 `const_desc_table' records which constants already have label strings. */
2557
2558 rtx
2559 output_constant_def (tree exp, int defer)
2560 {
2561 struct constant_descriptor_tree *desc;
2562 struct constant_descriptor_tree key;
2563 void **loc;
2564
2565 /* Look up EXP in the table of constant descriptors. If we didn't find
2566 it, create a new one. */
2567 key.value = exp;
2568 loc = htab_find_slot (const_desc_htab, &key, INSERT);
2569
2570 desc = *loc;
2571 if (desc == 0)
2572 {
2573 desc = build_constant_desc (exp);
2574 *loc = desc;
2575 }
2576
2577 maybe_output_constant_def_contents (desc, defer);
2578 return desc->rtl;
2579 }
2580
2581 /* Subroutine of output_constant_def: Decide whether or not we need to
2582 output the constant DESC now, and if so, do it. */
2583 static void
2584 maybe_output_constant_def_contents (struct constant_descriptor_tree *desc,
2585 int defer)
2586 {
2587 rtx symbol = XEXP (desc->rtl, 0);
2588 tree exp = desc->value;
2589
2590 if (flag_syntax_only)
2591 return;
2592
2593 if (TREE_ASM_WRITTEN (exp))
2594 /* Already output; don't do it again. */
2595 return;
2596
2597 /* We can always defer constants as long as the context allows
2598 doing so. */
2599 if (defer)
2600 {
2601 /* Increment n_deferred_constants if it exists. It needs to be at
2602 least as large as the number of constants actually referred to
2603 by the function. If it's too small we'll stop looking too early
2604 and fail to emit constants; if it's too large we'll only look
2605 through the entire function when we could have stopped earlier. */
2606 if (cfun)
2607 n_deferred_constants++;
2608 return;
2609 }
2610
2611 output_constant_def_contents (symbol);
2612 }
2613
2614 /* We must output the constant data referred to by SYMBOL; do so. */
2615
2616 static void
2617 output_constant_def_contents (rtx symbol)
2618 {
2619 tree exp = SYMBOL_REF_DECL (symbol);
2620 const char *label = XSTR (symbol, 0);
2621 HOST_WIDE_INT size;
2622
2623 /* Make sure any other constants whose addresses appear in EXP
2624 are assigned label numbers. */
2625 int reloc = compute_reloc_for_constant (exp);
2626
2627 /* Align the location counter as required by EXP's data type. */
2628 int align = TYPE_ALIGN (TREE_TYPE (exp));
2629 #ifdef CONSTANT_ALIGNMENT
2630 align = CONSTANT_ALIGNMENT (exp, align);
2631 #endif
2632
2633 output_addressed_constants (exp);
2634
2635 /* We are no longer deferring this constant. */
2636 TREE_ASM_WRITTEN (exp) = 1;
2637
2638 if (IN_NAMED_SECTION (exp))
2639 named_section (exp, NULL, reloc);
2640 else
2641 targetm.asm_out.select_section (exp, reloc, align);
2642
2643 if (align > BITS_PER_UNIT)
2644 {
2645 ASM_OUTPUT_ALIGN (asm_out_file, floor_log2 (align / BITS_PER_UNIT));
2646 }
2647
2648 size = int_size_in_bytes (TREE_TYPE (exp));
2649 if (TREE_CODE (exp) == STRING_CST)
2650 size = MAX (TREE_STRING_LENGTH (exp), size);
2651
2652 /* Do any machine/system dependent processing of the constant. */
2653 #ifdef ASM_DECLARE_CONSTANT_NAME
2654 ASM_DECLARE_CONSTANT_NAME (asm_out_file, label, exp, size);
2655 #else
2656 /* Standard thing is just output label for the constant. */
2657 ASM_OUTPUT_LABEL (asm_out_file, label);
2658 #endif /* ASM_DECLARE_CONSTANT_NAME */
2659
2660 /* Output the value of EXP. */
2661 output_constant (exp, size, align);
2662 if (flag_mudflap)
2663 mudflap_enqueue_constant (exp);
2664 }
2665
2666 /* Look up EXP in the table of constant descriptors. Return the rtl
2667 if it has been emitted, else null. */
2668
2669 rtx
2670 lookup_constant_def (tree exp)
2671 {
2672 struct constant_descriptor_tree *desc;
2673 struct constant_descriptor_tree key;
2674
2675 key.value = exp;
2676 desc = htab_find (const_desc_htab, &key);
2677
2678 return (desc ? desc->rtl : NULL_RTX);
2679 }
2680 \f
2681 /* Used in the hash tables to avoid outputting the same constant
2682 twice. Unlike 'struct constant_descriptor_tree', RTX constants
2683 are output once per function, not once per file. */
2684 /* ??? Only a few targets need per-function constant pools. Most
2685 can use one per-file pool. Should add a targetm bit to tell the
2686 difference. */
2687
2688 struct rtx_constant_pool GTY(())
2689 {
2690 /* Pointers to first and last constant in pool, as ordered by offset. */
2691 struct constant_descriptor_rtx *first;
2692 struct constant_descriptor_rtx *last;
2693
2694 /* Hash facility for making memory-constants from constant rtl-expressions.
2695 It is used on RISC machines where immediate integer arguments and
2696 constant addresses are restricted so that such constants must be stored
2697 in memory. */
2698 htab_t GTY((param_is (struct constant_descriptor_rtx))) const_rtx_htab;
2699 htab_t GTY((param_is (struct constant_descriptor_rtx))) const_rtx_sym_htab;
2700
2701 /* Current offset in constant pool (does not include any
2702 machine-specific header). */
2703 HOST_WIDE_INT offset;
2704 };
2705
2706 struct constant_descriptor_rtx GTY((chain_next ("%h.next")))
2707 {
2708 struct constant_descriptor_rtx *next;
2709 rtx mem;
2710 rtx sym;
2711 rtx constant;
2712 HOST_WIDE_INT offset;
2713 hashval_t hash;
2714 enum machine_mode mode;
2715 unsigned int align;
2716 int labelno;
2717 int mark;
2718 };
2719
2720 /* Hash and compare functions for const_rtx_htab. */
2721
2722 static hashval_t
2723 const_desc_rtx_hash (const void *ptr)
2724 {
2725 const struct constant_descriptor_rtx *desc = ptr;
2726 return desc->hash;
2727 }
2728
2729 static int
2730 const_desc_rtx_eq (const void *a, const void *b)
2731 {
2732 const struct constant_descriptor_rtx *x = a;
2733 const struct constant_descriptor_rtx *y = b;
2734
2735 if (x->mode != y->mode)
2736 return 0;
2737 return rtx_equal_p (x->constant, y->constant);
2738 }
2739
2740 /* Hash and compare functions for const_rtx_sym_htab. */
2741
2742 static hashval_t
2743 const_desc_rtx_sym_hash (const void *ptr)
2744 {
2745 const struct constant_descriptor_rtx *desc = ptr;
2746 return htab_hash_string (XSTR (desc->sym, 0));
2747 }
2748
2749 static int
2750 const_desc_rtx_sym_eq (const void *a, const void *b)
2751 {
2752 const struct constant_descriptor_rtx *x = a;
2753 const struct constant_descriptor_rtx *y = b;
2754 return XSTR (x->sym, 0) == XSTR (y->sym, 0);
2755 }
2756
2757 /* This is the worker function for const_rtx_hash, called via for_each_rtx. */
2758
2759 static int
2760 const_rtx_hash_1 (rtx *xp, void *data)
2761 {
2762 unsigned HOST_WIDE_INT hwi;
2763 enum machine_mode mode;
2764 enum rtx_code code;
2765 hashval_t h, *hp;
2766 rtx x;
2767
2768 x = *xp;
2769 code = GET_CODE (x);
2770 mode = GET_MODE (x);
2771 h = (hashval_t) code * 1048573 + mode;
2772
2773 switch (code)
2774 {
2775 case CONST_INT:
2776 hwi = INTVAL (x);
2777 fold_hwi:
2778 {
2779 const int shift = sizeof (hashval_t) * CHAR_BIT;
2780 const int n = sizeof (HOST_WIDE_INT) / sizeof (hashval_t);
2781 int i;
2782
2783 h ^= (hashval_t) hwi;
2784 for (i = 1; i < n; ++i)
2785 {
2786 hwi >>= shift;
2787 h ^= (hashval_t) hwi;
2788 }
2789 }
2790 break;
2791
2792 case CONST_DOUBLE:
2793 if (mode == VOIDmode)
2794 {
2795 hwi = CONST_DOUBLE_LOW (x) ^ CONST_DOUBLE_HIGH (x);
2796 goto fold_hwi;
2797 }
2798 else
2799 h ^= real_hash (CONST_DOUBLE_REAL_VALUE (x));
2800 break;
2801
2802 case SYMBOL_REF:
2803 h ^= htab_hash_string (XSTR (x, 0));
2804 break;
2805
2806 case LABEL_REF:
2807 h = h * 251 + CODE_LABEL_NUMBER (XEXP (x, 0));
2808 break;
2809
2810 case UNSPEC:
2811 case UNSPEC_VOLATILE:
2812 h = h * 251 + XINT (x, 1);
2813 break;
2814
2815 default:
2816 break;
2817 }
2818
2819 hp = data;
2820 *hp = *hp * 509 + h;
2821 return 0;
2822 }
2823
2824 /* Compute a hash value for X, which should be a constant. */
2825
2826 static hashval_t
2827 const_rtx_hash (rtx x)
2828 {
2829 hashval_t h = 0;
2830 for_each_rtx (&x, const_rtx_hash_1, &h);
2831 return h;
2832 }
2833
2834 \f
2835 /* Initialize constant pool hashing for a new function. */
2836
2837 void
2838 init_varasm_status (struct function *f)
2839 {
2840 struct varasm_status *p;
2841 struct rtx_constant_pool *pool;
2842
2843 p = ggc_alloc (sizeof (struct varasm_status));
2844 f->varasm = p;
2845
2846 pool = ggc_alloc (sizeof (struct rtx_constant_pool));
2847 p->pool = pool;
2848 p->deferred_constants = 0;
2849
2850 pool->const_rtx_htab = htab_create_ggc (31, const_desc_rtx_hash,
2851 const_desc_rtx_eq, NULL);
2852 pool->const_rtx_sym_htab = htab_create_ggc (31, const_desc_rtx_sym_hash,
2853 const_desc_rtx_sym_eq, NULL);
2854 pool->first = pool->last = NULL;
2855 pool->offset = 0;
2856 }
2857 \f
2858 /* Given a MINUS expression, simplify it if both sides
2859 include the same symbol. */
2860
2861 rtx
2862 simplify_subtraction (rtx x)
2863 {
2864 rtx r = simplify_rtx (x);
2865 return r ? r : x;
2866 }
2867 \f
2868 /* Given a constant rtx X, make (or find) a memory constant for its value
2869 and return a MEM rtx to refer to it in memory. */
2870
2871 rtx
2872 force_const_mem (enum machine_mode mode, rtx x)
2873 {
2874 struct constant_descriptor_rtx *desc, tmp;
2875 struct rtx_constant_pool *pool = cfun->varasm->pool;
2876 char label[256];
2877 rtx def, symbol;
2878 hashval_t hash;
2879 unsigned int align;
2880 void **slot;
2881
2882 /* If we're not allowed to drop X into the constant pool, don't. */
2883 if (targetm.cannot_force_const_mem (x))
2884 return NULL_RTX;
2885
2886 /* Lookup the value in the hashtable. */
2887 tmp.constant = x;
2888 tmp.mode = mode;
2889 hash = const_rtx_hash (x);
2890 slot = htab_find_slot_with_hash (pool->const_rtx_htab, &tmp, hash, INSERT);
2891 desc = *slot;
2892
2893 /* If the constant was already present, return its memory. */
2894 if (desc)
2895 return copy_rtx (desc->mem);
2896
2897 /* Otherwise, create a new descriptor. */
2898 desc = ggc_alloc (sizeof (*desc));
2899 *slot = desc;
2900
2901 /* Align the location counter as required by EXP's data type. */
2902 align = GET_MODE_ALIGNMENT (mode == VOIDmode ? word_mode : mode);
2903 #ifdef CONSTANT_ALIGNMENT
2904 {
2905 tree type = lang_hooks.types.type_for_mode (mode, 0);
2906 if (type != NULL_TREE)
2907 align = CONSTANT_ALIGNMENT (make_tree (type, x), align);
2908 }
2909 #endif
2910
2911 pool->offset += (align / BITS_PER_UNIT) - 1;
2912 pool->offset &= ~ ((align / BITS_PER_UNIT) - 1);
2913
2914 desc->next = NULL;
2915 desc->constant = tmp.constant;
2916 desc->offset = pool->offset;
2917 desc->hash = hash;
2918 desc->mode = mode;
2919 desc->align = align;
2920 desc->labelno = const_labelno;
2921 desc->mark = 0;
2922
2923 pool->offset += GET_MODE_SIZE (mode);
2924 if (pool->last)
2925 pool->last->next = desc;
2926 else
2927 pool->first = pool->last = desc;
2928 pool->last = desc;
2929
2930 /* Create a string containing the label name, in LABEL. */
2931 ASM_GENERATE_INTERNAL_LABEL (label, "LC", const_labelno);
2932 ++const_labelno;
2933
2934 /* Construct the SYMBOL_REF. Make sure to mark it as belonging to
2935 the constants pool. */
2936 desc->sym = symbol = gen_rtx_SYMBOL_REF (Pmode, ggc_strdup (label));
2937 SYMBOL_REF_FLAGS (symbol) = SYMBOL_FLAG_LOCAL;
2938 CONSTANT_POOL_ADDRESS_P (symbol) = 1;
2939 current_function_uses_const_pool = 1;
2940
2941 /* Insert the descriptor into the symbol cross-reference table too. */
2942 slot = htab_find_slot (pool->const_rtx_sym_htab, desc, INSERT);
2943 if (*slot)
2944 abort ();
2945 *slot = desc;
2946
2947 /* Construct the MEM. */
2948 desc->mem = def = gen_rtx_MEM (mode, symbol);
2949 set_mem_attributes (def, lang_hooks.types.type_for_mode (mode, 0), 1);
2950 RTX_UNCHANGING_P (def) = 1;
2951
2952 /* If we're dropping a label to the constant pool, make sure we
2953 don't delete it. */
2954 if (GET_CODE (x) == LABEL_REF)
2955 LABEL_PRESERVE_P (XEXP (x, 0)) = 1;
2956
2957 return copy_rtx (def);
2958 }
2959 \f
2960 /* Given a SYMBOL_REF with CONSTANT_POOL_ADDRESS_P true, return a pointer to
2961 the corresponding constant_descriptor_rtx structure. */
2962
2963 static struct constant_descriptor_rtx *
2964 find_pool_constant (struct rtx_constant_pool *pool, rtx sym)
2965 {
2966 struct constant_descriptor_rtx tmp;
2967 tmp.sym = sym;
2968 return htab_find (pool->const_rtx_sym_htab, &tmp);
2969 }
2970
2971 /* Given a constant pool SYMBOL_REF, return the corresponding constant. */
2972
2973 rtx
2974 get_pool_constant (rtx addr)
2975 {
2976 return find_pool_constant (cfun->varasm->pool, addr)->constant;
2977 }
2978
2979 /* Given a constant pool SYMBOL_REF, return the corresponding constant
2980 and whether it has been output or not. */
2981
2982 rtx
2983 get_pool_constant_mark (rtx addr, bool *pmarked)
2984 {
2985 struct constant_descriptor_rtx *desc;
2986
2987 desc = find_pool_constant (cfun->varasm->pool, addr);
2988 *pmarked = (desc->mark != 0);
2989 return desc->constant;
2990 }
2991
2992 /* Likewise, but for the constant pool of a specific function. */
2993
2994 rtx
2995 get_pool_constant_for_function (struct function *f, rtx addr)
2996 {
2997 return find_pool_constant (f->varasm->pool, addr)->constant;
2998 }
2999
3000 /* Similar, return the mode. */
3001
3002 enum machine_mode
3003 get_pool_mode (rtx addr)
3004 {
3005 return find_pool_constant (cfun->varasm->pool, addr)->mode;
3006 }
3007
3008 enum machine_mode
3009 get_pool_mode_for_function (struct function *f, rtx addr)
3010 {
3011 return find_pool_constant (f->varasm->pool, addr)->mode;
3012 }
3013
3014 /* Similar, return the offset in the constant pool. */
3015
3016 int
3017 get_pool_offset (rtx addr)
3018 {
3019 return find_pool_constant (cfun->varasm->pool, addr)->offset;
3020 }
3021
3022 /* Return the size of the constant pool. */
3023
3024 int
3025 get_pool_size (void)
3026 {
3027 return cfun->varasm->pool->offset;
3028 }
3029 \f
3030 /* Worker function for output_constant_pool_1. Emit assembly for X
3031 in MODE with known alignment ALIGN. */
3032
3033 static void
3034 output_constant_pool_2 (enum machine_mode mode, rtx x, unsigned int align)
3035 {
3036 switch (GET_MODE_CLASS (mode))
3037 {
3038 case MODE_FLOAT:
3039 if (GET_CODE (x) != CONST_DOUBLE)
3040 abort ();
3041 else
3042 {
3043 REAL_VALUE_TYPE r;
3044 REAL_VALUE_FROM_CONST_DOUBLE (r, x);
3045 assemble_real (r, mode, align);
3046 }
3047 break;
3048
3049 case MODE_INT:
3050 case MODE_PARTIAL_INT:
3051 assemble_integer (x, GET_MODE_SIZE (mode), align, 1);
3052 break;
3053
3054 case MODE_VECTOR_FLOAT:
3055 case MODE_VECTOR_INT:
3056 {
3057 int i, units;
3058 enum machine_mode submode = GET_MODE_INNER (mode);
3059 unsigned int subalign = MIN (align, GET_MODE_BITSIZE (submode));
3060
3061 if (GET_CODE (x) != CONST_VECTOR)
3062 abort ();
3063 units = CONST_VECTOR_NUNITS (x);
3064
3065 for (i = 0; i < units; i++)
3066 {
3067 rtx elt = CONST_VECTOR_ELT (x, i);
3068 output_constant_pool_2 (submode, elt, i ? subalign : align);
3069 }
3070 }
3071 break;
3072
3073 default:
3074 abort ();
3075 }
3076 }
3077
3078 /* Worker function for output_constant_pool. Emit POOL. */
3079
3080 static void
3081 output_constant_pool_1 (struct constant_descriptor_rtx *desc)
3082 {
3083 rtx x, tmp;
3084
3085 if (!desc->mark)
3086 return;
3087 x = desc->constant;
3088
3089 /* See if X is a LABEL_REF (or a CONST referring to a LABEL_REF)
3090 whose CODE_LABEL has been deleted. This can occur if a jump table
3091 is eliminated by optimization. If so, write a constant of zero
3092 instead. Note that this can also happen by turning the
3093 CODE_LABEL into a NOTE. */
3094 /* ??? This seems completely and utterly wrong. Certainly it's
3095 not true for NOTE_INSN_DELETED_LABEL, but I disbelieve proper
3096 functioning even with INSN_DELETED_P and friends. */
3097
3098 tmp = x;
3099 switch (GET_CODE (x))
3100 {
3101 case CONST:
3102 if (GET_CODE (XEXP (x, 0)) != PLUS
3103 || GET_CODE (XEXP (XEXP (x, 0), 0)) != LABEL_REF)
3104 break;
3105 tmp = XEXP (XEXP (x, 0), 0);
3106 /* FALLTHRU */
3107
3108 case LABEL_REF:
3109 tmp = XEXP (x, 0);
3110 if (INSN_DELETED_P (tmp)
3111 || (NOTE_P (tmp)
3112 && NOTE_LINE_NUMBER (tmp) == NOTE_INSN_DELETED))
3113 {
3114 abort ();
3115 x = const0_rtx;
3116 }
3117 break;
3118
3119 default:
3120 break;
3121 }
3122
3123 /* First switch to correct section. */
3124 targetm.asm_out.select_rtx_section (desc->mode, x, desc->align);
3125
3126 #ifdef ASM_OUTPUT_SPECIAL_POOL_ENTRY
3127 ASM_OUTPUT_SPECIAL_POOL_ENTRY (asm_out_file, x, desc->mode,
3128 desc->align, desc->labelno, done);
3129 #endif
3130
3131 assemble_align (desc->align);
3132
3133 /* Output the label. */
3134 targetm.asm_out.internal_label (asm_out_file, "LC", desc->labelno);
3135
3136 /* Output the data. */
3137 output_constant_pool_2 (desc->mode, x, desc->align);
3138
3139 /* Make sure all constants in SECTION_MERGE and not SECTION_STRINGS
3140 sections have proper size. */
3141 if (desc->align > GET_MODE_BITSIZE (desc->mode)
3142 && in_section == in_named
3143 && get_named_section_flags (in_named_name) & SECTION_MERGE)
3144 assemble_align (desc->align);
3145
3146 #ifdef ASM_OUTPUT_SPECIAL_POOL_ENTRY
3147 done:
3148 #endif
3149 return;
3150 }
3151
3152 /* Given a SYMBOL_REF CURRENT_RTX, mark it and all constants it refers
3153 to as used. Emit referenced deferred strings. This function can
3154 be used with for_each_rtx to mark all SYMBOL_REFs in an rtx. */
3155
3156 static int
3157 mark_constant (rtx *current_rtx, void *data)
3158 {
3159 struct rtx_constant_pool *pool = data;
3160 rtx x = *current_rtx;
3161
3162 if (x == NULL_RTX || GET_CODE (x) != SYMBOL_REF)
3163 return 0;
3164
3165 if (CONSTANT_POOL_ADDRESS_P (x))
3166 {
3167 struct constant_descriptor_rtx *desc = find_pool_constant (pool, x);
3168 if (desc->mark == 0)
3169 {
3170 desc->mark = 1;
3171 for_each_rtx (&desc->constant, mark_constant, pool);
3172 }
3173 }
3174 else if (TREE_CONSTANT_POOL_ADDRESS_P (x))
3175 {
3176 tree exp = SYMBOL_REF_DECL (x);
3177 if (!TREE_ASM_WRITTEN (exp))
3178 {
3179 n_deferred_constants--;
3180 output_constant_def_contents (x);
3181 }
3182 }
3183
3184 return -1;
3185 }
3186
3187 /* Look through appropriate parts of INSN, marking all entries in the
3188 constant pool which are actually being used. Entries that are only
3189 referenced by other constants are also marked as used. Emit
3190 deferred strings that are used. */
3191
3192 static void
3193 mark_constants (struct rtx_constant_pool *pool, rtx insn)
3194 {
3195 if (!INSN_P (insn))
3196 return;
3197
3198 /* Insns may appear inside a SEQUENCE. Only check the patterns of
3199 insns, not any notes that may be attached. We don't want to mark
3200 a constant just because it happens to appear in a REG_EQUIV note. */
3201 if (GET_CODE (PATTERN (insn)) == SEQUENCE)
3202 {
3203 rtx seq = PATTERN (insn);
3204 int i, n = XVECLEN (seq, 0);
3205 for (i = 0; i < n; ++i)
3206 {
3207 rtx subinsn = XVECEXP (seq, 0, i);
3208 if (INSN_P (subinsn))
3209 for_each_rtx (&PATTERN (subinsn), mark_constant, pool);
3210 }
3211 }
3212 else
3213 for_each_rtx (&PATTERN (insn), mark_constant, pool);
3214 }
3215
3216 /* Look through the instructions for this function, and mark all the
3217 entries in POOL which are actually being used. Emit deferred constants
3218 which have indeed been used. */
3219
3220 static void
3221 mark_constant_pool (struct rtx_constant_pool *pool)
3222 {
3223 rtx insn, link;
3224
3225 if (pool->first == 0 && n_deferred_constants == 0)
3226 return;
3227
3228 for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
3229 mark_constants (pool, insn);
3230
3231 for (link = current_function_epilogue_delay_list;
3232 link;
3233 link = XEXP (link, 1))
3234 mark_constants (pool, XEXP (link, 0));
3235 }
3236
3237 /* Write all the constants in the constant pool. */
3238
3239 void
3240 output_constant_pool (const char *fnname ATTRIBUTE_UNUSED,
3241 tree fndecl ATTRIBUTE_UNUSED)
3242 {
3243 struct rtx_constant_pool *pool = cfun->varasm->pool;
3244 struct constant_descriptor_rtx *desc;
3245
3246 /* It is possible for gcc to call force_const_mem and then to later
3247 discard the instructions which refer to the constant. In such a
3248 case we do not need to output the constant. */
3249 mark_constant_pool (pool);
3250
3251 #ifdef ASM_OUTPUT_POOL_PROLOGUE
3252 ASM_OUTPUT_POOL_PROLOGUE (asm_out_file, fnname, fndecl, pool->offset);
3253 #endif
3254
3255 for (desc = pool->first; desc ; desc = desc->next)
3256 output_constant_pool_1 (desc);
3257
3258 #ifdef ASM_OUTPUT_POOL_EPILOGUE
3259 ASM_OUTPUT_POOL_EPILOGUE (asm_out_file, fnname, fndecl, pool->offset);
3260 #endif
3261 }
3262 \f
3263 /* Determine what kind of relocations EXP may need. */
3264
3265 int
3266 compute_reloc_for_constant (tree exp)
3267 {
3268 int reloc = 0, reloc2;
3269 tree tem;
3270
3271 /* Give the front-end a chance to convert VALUE to something that
3272 looks more like a constant to the back-end. */
3273 exp = lang_hooks.expand_constant (exp);
3274
3275 switch (TREE_CODE (exp))
3276 {
3277 case ADDR_EXPR:
3278 case FDESC_EXPR:
3279 /* Go inside any operations that get_inner_reference can handle and see
3280 if what's inside is a constant: no need to do anything here for
3281 addresses of variables or functions. */
3282 for (tem = TREE_OPERAND (exp, 0); handled_component_p (tem);
3283 tem = TREE_OPERAND (tem, 0))
3284 ;
3285
3286 if (TREE_PUBLIC (tem))
3287 reloc |= 2;
3288 else
3289 reloc |= 1;
3290 break;
3291
3292 case PLUS_EXPR:
3293 reloc = compute_reloc_for_constant (TREE_OPERAND (exp, 0));
3294 reloc |= compute_reloc_for_constant (TREE_OPERAND (exp, 1));
3295 break;
3296
3297 case MINUS_EXPR:
3298 reloc = compute_reloc_for_constant (TREE_OPERAND (exp, 0));
3299 reloc2 = compute_reloc_for_constant (TREE_OPERAND (exp, 1));
3300 /* The difference of two local labels is computable at link time. */
3301 if (reloc == 1 && reloc2 == 1)
3302 reloc = 0;
3303 else
3304 reloc |= reloc2;
3305 break;
3306
3307 case NOP_EXPR:
3308 case CONVERT_EXPR:
3309 case NON_LVALUE_EXPR:
3310 reloc = compute_reloc_for_constant (TREE_OPERAND (exp, 0));
3311 break;
3312
3313 case CONSTRUCTOR:
3314 for (tem = CONSTRUCTOR_ELTS (exp); tem; tem = TREE_CHAIN (tem))
3315 if (TREE_VALUE (tem) != 0)
3316 reloc |= compute_reloc_for_constant (TREE_VALUE (tem));
3317
3318 break;
3319
3320 default:
3321 break;
3322 }
3323 return reloc;
3324 }
3325
3326 /* Find all the constants whose addresses are referenced inside of EXP,
3327 and make sure assembler code with a label has been output for each one.
3328 Indicate whether an ADDR_EXPR has been encountered. */
3329
3330 static void
3331 output_addressed_constants (tree exp)
3332 {
3333 tree tem;
3334
3335 /* Give the front-end a chance to convert VALUE to something that
3336 looks more like a constant to the back-end. */
3337 exp = lang_hooks.expand_constant (exp);
3338
3339 switch (TREE_CODE (exp))
3340 {
3341 case ADDR_EXPR:
3342 case FDESC_EXPR:
3343 /* Go inside any operations that get_inner_reference can handle and see
3344 if what's inside is a constant: no need to do anything here for
3345 addresses of variables or functions. */
3346 for (tem = TREE_OPERAND (exp, 0); handled_component_p (tem);
3347 tem = TREE_OPERAND (tem, 0))
3348 ;
3349
3350 if (TREE_CODE_CLASS (TREE_CODE (tem)) == 'c'
3351 || TREE_CODE (tem) == CONSTRUCTOR)
3352 output_constant_def (tem, 0);
3353 break;
3354
3355 case PLUS_EXPR:
3356 case MINUS_EXPR:
3357 output_addressed_constants (TREE_OPERAND (exp, 1));
3358 /* Fall through. */
3359
3360 case NOP_EXPR:
3361 case CONVERT_EXPR:
3362 case NON_LVALUE_EXPR:
3363 output_addressed_constants (TREE_OPERAND (exp, 0));
3364 break;
3365
3366 case CONSTRUCTOR:
3367 for (tem = CONSTRUCTOR_ELTS (exp); tem; tem = TREE_CHAIN (tem))
3368 if (TREE_VALUE (tem) != 0)
3369 output_addressed_constants (TREE_VALUE (tem));
3370
3371 break;
3372
3373 default:
3374 break;
3375 }
3376 }
3377 \f
3378 /* Return nonzero if VALUE is a valid constant-valued expression
3379 for use in initializing a static variable; one that can be an
3380 element of a "constant" initializer.
3381
3382 Return null_pointer_node if the value is absolute;
3383 if it is relocatable, return the variable that determines the relocation.
3384 We assume that VALUE has been folded as much as possible;
3385 therefore, we do not need to check for such things as
3386 arithmetic-combinations of integers. */
3387
3388 tree
3389 initializer_constant_valid_p (tree value, tree endtype)
3390 {
3391 /* Give the front-end a chance to convert VALUE to something that
3392 looks more like a constant to the back-end. */
3393 value = lang_hooks.expand_constant (value);
3394
3395 switch (TREE_CODE (value))
3396 {
3397 case CONSTRUCTOR:
3398 if ((TREE_CODE (TREE_TYPE (value)) == UNION_TYPE
3399 || TREE_CODE (TREE_TYPE (value)) == RECORD_TYPE)
3400 && TREE_CONSTANT (value)
3401 && CONSTRUCTOR_ELTS (value))
3402 {
3403 tree elt;
3404 bool absolute = true;
3405
3406 for (elt = CONSTRUCTOR_ELTS (value); elt; elt = TREE_CHAIN (elt))
3407 {
3408 tree reloc;
3409 value = TREE_VALUE (elt);
3410 reloc = initializer_constant_valid_p (value, TREE_TYPE (value));
3411 if (!reloc)
3412 return NULL_TREE;
3413 if (reloc != null_pointer_node)
3414 absolute = false;
3415 }
3416 /* For a non-absolute relocation, there is no single
3417 variable that can be "the variable that determines the
3418 relocation." */
3419 return absolute ? null_pointer_node : error_mark_node;
3420 }
3421
3422 return TREE_STATIC (value) ? null_pointer_node : NULL_TREE;
3423
3424 case INTEGER_CST:
3425 case VECTOR_CST:
3426 case REAL_CST:
3427 case STRING_CST:
3428 case COMPLEX_CST:
3429 return null_pointer_node;
3430
3431 case ADDR_EXPR:
3432 case FDESC_EXPR:
3433 return staticp (TREE_OPERAND (value, 0)) ? TREE_OPERAND (value, 0) : 0;
3434
3435 case VIEW_CONVERT_EXPR:
3436 case NON_LVALUE_EXPR:
3437 return initializer_constant_valid_p (TREE_OPERAND (value, 0), endtype);
3438
3439 case CONVERT_EXPR:
3440 case NOP_EXPR:
3441 /* Allow conversions between pointer types. */
3442 if (POINTER_TYPE_P (TREE_TYPE (value))
3443 && POINTER_TYPE_P (TREE_TYPE (TREE_OPERAND (value, 0))))
3444 return initializer_constant_valid_p (TREE_OPERAND (value, 0), endtype);
3445
3446 /* Allow conversions between real types. */
3447 if (FLOAT_TYPE_P (TREE_TYPE (value))
3448 && FLOAT_TYPE_P (TREE_TYPE (TREE_OPERAND (value, 0))))
3449 return initializer_constant_valid_p (TREE_OPERAND (value, 0), endtype);
3450
3451 /* Allow length-preserving conversions between integer types. */
3452 if (INTEGRAL_TYPE_P (TREE_TYPE (value))
3453 && INTEGRAL_TYPE_P (TREE_TYPE (TREE_OPERAND (value, 0)))
3454 && (TYPE_PRECISION (TREE_TYPE (value))
3455 == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (value, 0)))))
3456 return initializer_constant_valid_p (TREE_OPERAND (value, 0), endtype);
3457
3458 /* Allow conversions between other integer types only if
3459 explicit value. */
3460 if (INTEGRAL_TYPE_P (TREE_TYPE (value))
3461 && INTEGRAL_TYPE_P (TREE_TYPE (TREE_OPERAND (value, 0))))
3462 {
3463 tree inner = initializer_constant_valid_p (TREE_OPERAND (value, 0),
3464 endtype);
3465 if (inner == null_pointer_node)
3466 return null_pointer_node;
3467 break;
3468 }
3469
3470 /* Allow (int) &foo provided int is as wide as a pointer. */
3471 if (INTEGRAL_TYPE_P (TREE_TYPE (value))
3472 && POINTER_TYPE_P (TREE_TYPE (TREE_OPERAND (value, 0)))
3473 && (TYPE_PRECISION (TREE_TYPE (value))
3474 >= TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (value, 0)))))
3475 return initializer_constant_valid_p (TREE_OPERAND (value, 0),
3476 endtype);
3477
3478 /* Likewise conversions from int to pointers, but also allow
3479 conversions from 0. */
3480 if ((POINTER_TYPE_P (TREE_TYPE (value))
3481 || TREE_CODE (TREE_TYPE (value)) == OFFSET_TYPE)
3482 && INTEGRAL_TYPE_P (TREE_TYPE (TREE_OPERAND (value, 0))))
3483 {
3484 if (integer_zerop (TREE_OPERAND (value, 0)))
3485 return null_pointer_node;
3486 else if (TYPE_PRECISION (TREE_TYPE (value))
3487 <= TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (value, 0))))
3488 return initializer_constant_valid_p (TREE_OPERAND (value, 0),
3489 endtype);
3490 }
3491
3492 /* Allow conversions to struct or union types if the value
3493 inside is okay. */
3494 if (TREE_CODE (TREE_TYPE (value)) == RECORD_TYPE
3495 || TREE_CODE (TREE_TYPE (value)) == UNION_TYPE)
3496 return initializer_constant_valid_p (TREE_OPERAND (value, 0),
3497 endtype);
3498 break;
3499
3500 case PLUS_EXPR:
3501 if (! INTEGRAL_TYPE_P (endtype)
3502 || TYPE_PRECISION (endtype) >= POINTER_SIZE)
3503 {
3504 tree valid0 = initializer_constant_valid_p (TREE_OPERAND (value, 0),
3505 endtype);
3506 tree valid1 = initializer_constant_valid_p (TREE_OPERAND (value, 1),
3507 endtype);
3508 /* If either term is absolute, use the other terms relocation. */
3509 if (valid0 == null_pointer_node)
3510 return valid1;
3511 if (valid1 == null_pointer_node)
3512 return valid0;
3513 }
3514 break;
3515
3516 case MINUS_EXPR:
3517 if (! INTEGRAL_TYPE_P (endtype)
3518 || TYPE_PRECISION (endtype) >= POINTER_SIZE)
3519 {
3520 tree valid0 = initializer_constant_valid_p (TREE_OPERAND (value, 0),
3521 endtype);
3522 tree valid1 = initializer_constant_valid_p (TREE_OPERAND (value, 1),
3523 endtype);
3524 /* Win if second argument is absolute. */
3525 if (valid1 == null_pointer_node)
3526 return valid0;
3527 /* Win if both arguments have the same relocation.
3528 Then the value is absolute. */
3529 if (valid0 == valid1 && valid0 != 0)
3530 return null_pointer_node;
3531
3532 /* Since GCC guarantees that string constants are unique in the
3533 generated code, a subtraction between two copies of the same
3534 constant string is absolute. */
3535 if (valid0 && TREE_CODE (valid0) == STRING_CST &&
3536 valid1 && TREE_CODE (valid1) == STRING_CST &&
3537 TREE_STRING_POINTER (valid0) == TREE_STRING_POINTER (valid1))
3538 return null_pointer_node;
3539 }
3540
3541 /* Support differences between labels. */
3542 if (INTEGRAL_TYPE_P (endtype))
3543 {
3544 tree op0, op1;
3545 op0 = TREE_OPERAND (value, 0);
3546 op1 = TREE_OPERAND (value, 1);
3547
3548 /* Like STRIP_NOPS except allow the operand mode to widen.
3549 This works around a feature of fold that simplifies
3550 (int)(p1 - p2) to ((int)p1 - (int)p2) under the theory
3551 that the narrower operation is cheaper. */
3552
3553 while (TREE_CODE (op0) == NOP_EXPR
3554 || TREE_CODE (op0) == CONVERT_EXPR
3555 || TREE_CODE (op0) == NON_LVALUE_EXPR)
3556 {
3557 tree inner = TREE_OPERAND (op0, 0);
3558 if (inner == error_mark_node
3559 || ! INTEGRAL_MODE_P (TYPE_MODE (TREE_TYPE (inner)))
3560 || (GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op0)))
3561 > GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (inner)))))
3562 break;
3563 op0 = inner;
3564 }
3565
3566 while (TREE_CODE (op1) == NOP_EXPR
3567 || TREE_CODE (op1) == CONVERT_EXPR
3568 || TREE_CODE (op1) == NON_LVALUE_EXPR)
3569 {
3570 tree inner = TREE_OPERAND (op1, 0);
3571 if (inner == error_mark_node
3572 || ! INTEGRAL_MODE_P (TYPE_MODE (TREE_TYPE (inner)))
3573 || (GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op1)))
3574 > GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (inner)))))
3575 break;
3576 op1 = inner;
3577 }
3578
3579 if (TREE_CODE (op0) == ADDR_EXPR
3580 && TREE_CODE (TREE_OPERAND (op0, 0)) == LABEL_DECL
3581 && TREE_CODE (op1) == ADDR_EXPR
3582 && TREE_CODE (TREE_OPERAND (op1, 0)) == LABEL_DECL)
3583 return null_pointer_node;
3584 }
3585 break;
3586
3587 default:
3588 break;
3589 }
3590
3591 return 0;
3592 }
3593 \f
3594 /* Output assembler code for constant EXP to FILE, with no label.
3595 This includes the pseudo-op such as ".int" or ".byte", and a newline.
3596 Assumes output_addressed_constants has been done on EXP already.
3597
3598 Generate exactly SIZE bytes of assembler data, padding at the end
3599 with zeros if necessary. SIZE must always be specified.
3600
3601 SIZE is important for structure constructors,
3602 since trailing members may have been omitted from the constructor.
3603 It is also important for initialization of arrays from string constants
3604 since the full length of the string constant might not be wanted.
3605 It is also needed for initialization of unions, where the initializer's
3606 type is just one member, and that may not be as long as the union.
3607
3608 There a case in which we would fail to output exactly SIZE bytes:
3609 for a structure constructor that wants to produce more than SIZE bytes.
3610 But such constructors will never be generated for any possible input.
3611
3612 ALIGN is the alignment of the data in bits. */
3613
3614 void
3615 output_constant (tree exp, unsigned HOST_WIDE_INT size, unsigned int align)
3616 {
3617 enum tree_code code;
3618 unsigned HOST_WIDE_INT thissize;
3619
3620 /* Some front-ends use constants other than the standard language-independent
3621 varieties, but which may still be output directly. Give the front-end a
3622 chance to convert EXP to a language-independent representation. */
3623 exp = lang_hooks.expand_constant (exp);
3624
3625 if (size == 0 || flag_syntax_only)
3626 return;
3627
3628 /* Eliminate any conversions since we'll be outputting the underlying
3629 constant. */
3630 while (TREE_CODE (exp) == NOP_EXPR || TREE_CODE (exp) == CONVERT_EXPR
3631 || TREE_CODE (exp) == NON_LVALUE_EXPR
3632 || TREE_CODE (exp) == VIEW_CONVERT_EXPR)
3633 exp = TREE_OPERAND (exp, 0);
3634
3635 code = TREE_CODE (TREE_TYPE (exp));
3636 thissize = int_size_in_bytes (TREE_TYPE (exp));
3637
3638 /* Allow a constructor with no elements for any data type.
3639 This means to fill the space with zeros. */
3640 if (TREE_CODE (exp) == CONSTRUCTOR && CONSTRUCTOR_ELTS (exp) == 0)
3641 {
3642 assemble_zeros (size);
3643 return;
3644 }
3645
3646 if (TREE_CODE (exp) == FDESC_EXPR)
3647 {
3648 #ifdef ASM_OUTPUT_FDESC
3649 HOST_WIDE_INT part = tree_low_cst (TREE_OPERAND (exp, 1), 0);
3650 tree decl = TREE_OPERAND (exp, 0);
3651 ASM_OUTPUT_FDESC (asm_out_file, decl, part);
3652 #else
3653 abort ();
3654 #endif
3655 return;
3656 }
3657
3658 /* Now output the underlying data. If we've handling the padding, return.
3659 Otherwise, break and ensure SIZE is the size written. */
3660 switch (code)
3661 {
3662 case CHAR_TYPE:
3663 case BOOLEAN_TYPE:
3664 case INTEGER_TYPE:
3665 case ENUMERAL_TYPE:
3666 case POINTER_TYPE:
3667 case REFERENCE_TYPE:
3668 case OFFSET_TYPE:
3669 if (! assemble_integer (expand_expr (exp, NULL_RTX, VOIDmode,
3670 EXPAND_INITIALIZER),
3671 MIN (size, thissize), align, 0))
3672 error ("initializer for integer value is too complicated");
3673 break;
3674
3675 case REAL_TYPE:
3676 if (TREE_CODE (exp) != REAL_CST)
3677 error ("initializer for floating value is not a floating constant");
3678
3679 assemble_real (TREE_REAL_CST (exp), TYPE_MODE (TREE_TYPE (exp)), align);
3680 break;
3681
3682 case COMPLEX_TYPE:
3683 output_constant (TREE_REALPART (exp), thissize / 2, align);
3684 output_constant (TREE_IMAGPART (exp), thissize / 2,
3685 min_align (align, BITS_PER_UNIT * (thissize / 2)));
3686 break;
3687
3688 case ARRAY_TYPE:
3689 case VECTOR_TYPE:
3690 if (TREE_CODE (exp) == CONSTRUCTOR)
3691 {
3692 output_constructor (exp, size, align);
3693 return;
3694 }
3695 else if (TREE_CODE (exp) == STRING_CST)
3696 {
3697 thissize = MIN ((unsigned HOST_WIDE_INT)TREE_STRING_LENGTH (exp),
3698 size);
3699 assemble_string (TREE_STRING_POINTER (exp), thissize);
3700 }
3701 else if (TREE_CODE (exp) == VECTOR_CST)
3702 {
3703 int elt_size;
3704 tree link;
3705 unsigned int nalign;
3706 enum machine_mode inner;
3707
3708 inner = TYPE_MODE (TREE_TYPE (TREE_TYPE (exp)));
3709 nalign = MIN (align, GET_MODE_ALIGNMENT (inner));
3710
3711 elt_size = GET_MODE_SIZE (inner);
3712
3713 link = TREE_VECTOR_CST_ELTS (exp);
3714 output_constant (TREE_VALUE (link), elt_size, align);
3715 while ((link = TREE_CHAIN (link)) != NULL)
3716 output_constant (TREE_VALUE (link), elt_size, nalign);
3717 }
3718 else
3719 abort ();
3720 break;
3721
3722 case RECORD_TYPE:
3723 case UNION_TYPE:
3724 if (TREE_CODE (exp) == CONSTRUCTOR)
3725 output_constructor (exp, size, align);
3726 else
3727 abort ();
3728 return;
3729
3730 case SET_TYPE:
3731 if (TREE_CODE (exp) == INTEGER_CST)
3732 assemble_integer (expand_expr (exp, NULL_RTX,
3733 VOIDmode, EXPAND_INITIALIZER),
3734 thissize, align, 1);
3735 else if (TREE_CODE (exp) == CONSTRUCTOR)
3736 {
3737 unsigned char *buffer = alloca (thissize);
3738 if (get_set_constructor_bytes (exp, buffer, thissize))
3739 abort ();
3740 assemble_string ((char *) buffer, thissize);
3741 }
3742 else
3743 error ("unknown set constructor type");
3744 return;
3745
3746 case ERROR_MARK:
3747 return;
3748
3749 default:
3750 abort ();
3751 }
3752
3753 if (size > thissize)
3754 assemble_zeros (size - thissize);
3755 }
3756
3757 \f
3758 /* Subroutine of output_constructor, used for computing the size of
3759 arrays of unspecified length. VAL must be a CONSTRUCTOR of an array
3760 type with an unspecified upper bound. */
3761
3762 static unsigned HOST_WIDE_INT
3763 array_size_for_constructor (tree val)
3764 {
3765 tree max_index, i;
3766
3767 /* This code used to attempt to handle string constants that are not
3768 arrays of single-bytes, but nothing else does, so there's no point in
3769 doing it here. */
3770 if (TREE_CODE (val) == STRING_CST)
3771 return TREE_STRING_LENGTH (val);
3772
3773 max_index = NULL_TREE;
3774 for (i = CONSTRUCTOR_ELTS (val); i; i = TREE_CHAIN (i))
3775 {
3776 tree index = TREE_PURPOSE (i);
3777
3778 if (TREE_CODE (index) == RANGE_EXPR)
3779 index = TREE_OPERAND (index, 1);
3780 if (max_index == NULL_TREE || tree_int_cst_lt (max_index, index))
3781 max_index = index;
3782 }
3783
3784 if (max_index == NULL_TREE)
3785 return 0;
3786
3787 /* Compute the total number of array elements. */
3788 i = size_binop (MINUS_EXPR, convert (sizetype, max_index),
3789 convert (sizetype,
3790 TYPE_MIN_VALUE (TYPE_DOMAIN (TREE_TYPE (val)))));
3791 i = size_binop (PLUS_EXPR, i, convert (sizetype, integer_one_node));
3792
3793 /* Multiply by the array element unit size to find number of bytes. */
3794 i = size_binop (MULT_EXPR, i, TYPE_SIZE_UNIT (TREE_TYPE (TREE_TYPE (val))));
3795
3796 return tree_low_cst (i, 1);
3797 }
3798
3799 /* Subroutine of output_constant, used for CONSTRUCTORs (aggregate constants).
3800 Generate at least SIZE bytes, padding if necessary. */
3801
3802 static void
3803 output_constructor (tree exp, unsigned HOST_WIDE_INT size,
3804 unsigned int align)
3805 {
3806 tree type = TREE_TYPE (exp);
3807 tree link, field = 0;
3808 tree min_index = 0;
3809 /* Number of bytes output or skipped so far.
3810 In other words, current position within the constructor. */
3811 HOST_WIDE_INT total_bytes = 0;
3812 /* Nonzero means BYTE contains part of a byte, to be output. */
3813 int byte_buffer_in_use = 0;
3814 int byte = 0;
3815
3816 if (HOST_BITS_PER_WIDE_INT < BITS_PER_UNIT)
3817 abort ();
3818
3819 if (TREE_CODE (type) == RECORD_TYPE)
3820 field = TYPE_FIELDS (type);
3821
3822 if (TREE_CODE (type) == ARRAY_TYPE
3823 && TYPE_DOMAIN (type) != 0)
3824 min_index = TYPE_MIN_VALUE (TYPE_DOMAIN (type));
3825
3826 /* As LINK goes through the elements of the constant,
3827 FIELD goes through the structure fields, if the constant is a structure.
3828 if the constant is a union, then we override this,
3829 by getting the field from the TREE_LIST element.
3830 But the constant could also be an array. Then FIELD is zero.
3831
3832 There is always a maximum of one element in the chain LINK for unions
3833 (even if the initializer in a source program incorrectly contains
3834 more one). */
3835 for (link = CONSTRUCTOR_ELTS (exp);
3836 link;
3837 link = TREE_CHAIN (link),
3838 field = field ? TREE_CHAIN (field) : 0)
3839 {
3840 tree val = TREE_VALUE (link);
3841 tree index = 0;
3842
3843 /* The element in a union constructor specifies the proper field
3844 or index. */
3845 if ((TREE_CODE (type) == RECORD_TYPE || TREE_CODE (type) == UNION_TYPE
3846 || TREE_CODE (type) == QUAL_UNION_TYPE)
3847 && TREE_PURPOSE (link) != 0)
3848 field = TREE_PURPOSE (link);
3849
3850 else if (TREE_CODE (type) == ARRAY_TYPE)
3851 index = TREE_PURPOSE (link);
3852
3853 #ifdef ASM_COMMENT_START
3854 if (field && flag_verbose_asm)
3855 fprintf (asm_out_file, "%s %s:\n",
3856 ASM_COMMENT_START,
3857 DECL_NAME (field)
3858 ? IDENTIFIER_POINTER (DECL_NAME (field))
3859 : "<anonymous>");
3860 #endif
3861
3862 /* Eliminate the marker that makes a cast not be an lvalue. */
3863 if (val != 0)
3864 STRIP_NOPS (val);
3865
3866 if (index && TREE_CODE (index) == RANGE_EXPR)
3867 {
3868 unsigned HOST_WIDE_INT fieldsize
3869 = int_size_in_bytes (TREE_TYPE (type));
3870 HOST_WIDE_INT lo_index = tree_low_cst (TREE_OPERAND (index, 0), 0);
3871 HOST_WIDE_INT hi_index = tree_low_cst (TREE_OPERAND (index, 1), 0);
3872 HOST_WIDE_INT index;
3873 unsigned int align2 = min_align (align, fieldsize * BITS_PER_UNIT);
3874
3875 for (index = lo_index; index <= hi_index; index++)
3876 {
3877 /* Output the element's initial value. */
3878 if (val == 0)
3879 assemble_zeros (fieldsize);
3880 else
3881 output_constant (val, fieldsize, align2);
3882
3883 /* Count its size. */
3884 total_bytes += fieldsize;
3885 }
3886 }
3887 else if (field == 0 || !DECL_BIT_FIELD (field))
3888 {
3889 /* An element that is not a bit-field. */
3890
3891 unsigned HOST_WIDE_INT fieldsize;
3892 /* Since this structure is static,
3893 we know the positions are constant. */
3894 HOST_WIDE_INT pos = field ? int_byte_position (field) : 0;
3895 unsigned int align2;
3896
3897 if (index != 0)
3898 pos = (tree_low_cst (TYPE_SIZE_UNIT (TREE_TYPE (val)), 1)
3899 * (tree_low_cst (index, 0) - tree_low_cst (min_index, 0)));
3900
3901 /* Output any buffered-up bit-fields preceding this element. */
3902 if (byte_buffer_in_use)
3903 {
3904 assemble_integer (GEN_INT (byte), 1, BITS_PER_UNIT, 1);
3905 total_bytes++;
3906 byte_buffer_in_use = 0;
3907 }
3908
3909 /* Advance to offset of this element.
3910 Note no alignment needed in an array, since that is guaranteed
3911 if each element has the proper size. */
3912 if ((field != 0 || index != 0) && pos != total_bytes)
3913 {
3914 assemble_zeros (pos - total_bytes);
3915 total_bytes = pos;
3916 }
3917
3918 /* Find the alignment of this element. */
3919 align2 = min_align (align, BITS_PER_UNIT * pos);
3920
3921 /* Determine size this element should occupy. */
3922 if (field)
3923 {
3924 fieldsize = 0;
3925
3926 /* If this is an array with an unspecified upper bound,
3927 the initializer determines the size. */
3928 /* ??? This ought to only checked if DECL_SIZE_UNIT is NULL,
3929 but we cannot do this until the deprecated support for
3930 initializing zero-length array members is removed. */
3931 if (TREE_CODE (TREE_TYPE (field)) == ARRAY_TYPE
3932 && TYPE_DOMAIN (TREE_TYPE (field))
3933 && ! TYPE_MAX_VALUE (TYPE_DOMAIN (TREE_TYPE (field))))
3934 {
3935 fieldsize = array_size_for_constructor (val);
3936 /* Given a non-empty initialization, this field had
3937 better be last. */
3938 if (fieldsize != 0 && TREE_CHAIN (field) != NULL_TREE)
3939 abort ();
3940 }
3941 else if (DECL_SIZE_UNIT (field))
3942 {
3943 /* ??? This can't be right. If the decl size overflows
3944 a host integer we will silently emit no data. */
3945 if (host_integerp (DECL_SIZE_UNIT (field), 1))
3946 fieldsize = tree_low_cst (DECL_SIZE_UNIT (field), 1);
3947 }
3948 }
3949 else
3950 fieldsize = int_size_in_bytes (TREE_TYPE (type));
3951
3952 /* Output the element's initial value. */
3953 if (val == 0)
3954 assemble_zeros (fieldsize);
3955 else
3956 output_constant (val, fieldsize, align2);
3957
3958 /* Count its size. */
3959 total_bytes += fieldsize;
3960 }
3961 else if (val != 0 && TREE_CODE (val) != INTEGER_CST)
3962 error ("invalid initial value for member `%s'",
3963 IDENTIFIER_POINTER (DECL_NAME (field)));
3964 else
3965 {
3966 /* Element that is a bit-field. */
3967
3968 HOST_WIDE_INT next_offset = int_bit_position (field);
3969 HOST_WIDE_INT end_offset
3970 = (next_offset + tree_low_cst (DECL_SIZE (field), 1));
3971
3972 if (val == 0)
3973 val = integer_zero_node;
3974
3975 /* If this field does not start in this (or, next) byte,
3976 skip some bytes. */
3977 if (next_offset / BITS_PER_UNIT != total_bytes)
3978 {
3979 /* Output remnant of any bit field in previous bytes. */
3980 if (byte_buffer_in_use)
3981 {
3982 assemble_integer (GEN_INT (byte), 1, BITS_PER_UNIT, 1);
3983 total_bytes++;
3984 byte_buffer_in_use = 0;
3985 }
3986
3987 /* If still not at proper byte, advance to there. */
3988 if (next_offset / BITS_PER_UNIT != total_bytes)
3989 {
3990 assemble_zeros (next_offset / BITS_PER_UNIT - total_bytes);
3991 total_bytes = next_offset / BITS_PER_UNIT;
3992 }
3993 }
3994
3995 if (! byte_buffer_in_use)
3996 byte = 0;
3997
3998 /* We must split the element into pieces that fall within
3999 separate bytes, and combine each byte with previous or
4000 following bit-fields. */
4001
4002 /* next_offset is the offset n fbits from the beginning of
4003 the structure to the next bit of this element to be processed.
4004 end_offset is the offset of the first bit past the end of
4005 this element. */
4006 while (next_offset < end_offset)
4007 {
4008 int this_time;
4009 int shift;
4010 HOST_WIDE_INT value;
4011 HOST_WIDE_INT next_byte = next_offset / BITS_PER_UNIT;
4012 HOST_WIDE_INT next_bit = next_offset % BITS_PER_UNIT;
4013
4014 /* Advance from byte to byte
4015 within this element when necessary. */
4016 while (next_byte != total_bytes)
4017 {
4018 assemble_integer (GEN_INT (byte), 1, BITS_PER_UNIT, 1);
4019 total_bytes++;
4020 byte = 0;
4021 }
4022
4023 /* Number of bits we can process at once
4024 (all part of the same byte). */
4025 this_time = MIN (end_offset - next_offset,
4026 BITS_PER_UNIT - next_bit);
4027 if (BYTES_BIG_ENDIAN)
4028 {
4029 /* On big-endian machine, take the most significant bits
4030 first (of the bits that are significant)
4031 and put them into bytes from the most significant end. */
4032 shift = end_offset - next_offset - this_time;
4033
4034 /* Don't try to take a bunch of bits that cross
4035 the word boundary in the INTEGER_CST. We can
4036 only select bits from the LOW or HIGH part
4037 not from both. */
4038 if (shift < HOST_BITS_PER_WIDE_INT
4039 && shift + this_time > HOST_BITS_PER_WIDE_INT)
4040 {
4041 this_time = shift + this_time - HOST_BITS_PER_WIDE_INT;
4042 shift = HOST_BITS_PER_WIDE_INT;
4043 }
4044
4045 /* Now get the bits from the appropriate constant word. */
4046 if (shift < HOST_BITS_PER_WIDE_INT)
4047 value = TREE_INT_CST_LOW (val);
4048 else if (shift < 2 * HOST_BITS_PER_WIDE_INT)
4049 {
4050 value = TREE_INT_CST_HIGH (val);
4051 shift -= HOST_BITS_PER_WIDE_INT;
4052 }
4053 else
4054 abort ();
4055
4056 /* Get the result. This works only when:
4057 1 <= this_time <= HOST_BITS_PER_WIDE_INT. */
4058 byte |= (((value >> shift)
4059 & (((HOST_WIDE_INT) 2 << (this_time - 1)) - 1))
4060 << (BITS_PER_UNIT - this_time - next_bit));
4061 }
4062 else
4063 {
4064 /* On little-endian machines,
4065 take first the least significant bits of the value
4066 and pack them starting at the least significant
4067 bits of the bytes. */
4068 shift = next_offset - int_bit_position (field);
4069
4070 /* Don't try to take a bunch of bits that cross
4071 the word boundary in the INTEGER_CST. We can
4072 only select bits from the LOW or HIGH part
4073 not from both. */
4074 if (shift < HOST_BITS_PER_WIDE_INT
4075 && shift + this_time > HOST_BITS_PER_WIDE_INT)
4076 this_time = (HOST_BITS_PER_WIDE_INT - shift);
4077
4078 /* Now get the bits from the appropriate constant word. */
4079 if (shift < HOST_BITS_PER_WIDE_INT)
4080 value = TREE_INT_CST_LOW (val);
4081 else if (shift < 2 * HOST_BITS_PER_WIDE_INT)
4082 {
4083 value = TREE_INT_CST_HIGH (val);
4084 shift -= HOST_BITS_PER_WIDE_INT;
4085 }
4086 else
4087 abort ();
4088
4089 /* Get the result. This works only when:
4090 1 <= this_time <= HOST_BITS_PER_WIDE_INT. */
4091 byte |= (((value >> shift)
4092 & (((HOST_WIDE_INT) 2 << (this_time - 1)) - 1))
4093 << next_bit);
4094 }
4095
4096 next_offset += this_time;
4097 byte_buffer_in_use = 1;
4098 }
4099 }
4100 }
4101
4102 if (byte_buffer_in_use)
4103 {
4104 assemble_integer (GEN_INT (byte), 1, BITS_PER_UNIT, 1);
4105 total_bytes++;
4106 }
4107
4108 if ((unsigned HOST_WIDE_INT)total_bytes < size)
4109 assemble_zeros (size - total_bytes);
4110 }
4111
4112 /* This TREE_LIST contains any weak symbol declarations waiting
4113 to be emitted. */
4114 static GTY(()) tree weak_decls;
4115
4116 /* Mark DECL as weak. */
4117
4118 static void
4119 mark_weak (tree decl)
4120 {
4121 DECL_WEAK (decl) = 1;
4122
4123 if (DECL_RTL_SET_P (decl)
4124 && MEM_P (DECL_RTL (decl))
4125 && XEXP (DECL_RTL (decl), 0)
4126 && GET_CODE (XEXP (DECL_RTL (decl), 0)) == SYMBOL_REF)
4127 SYMBOL_REF_WEAK (XEXP (DECL_RTL (decl), 0)) = 1;
4128 }
4129
4130 /* Merge weak status between NEWDECL and OLDDECL. */
4131
4132 void
4133 merge_weak (tree newdecl, tree olddecl)
4134 {
4135 if (DECL_WEAK (newdecl) == DECL_WEAK (olddecl))
4136 return;
4137
4138 if (DECL_WEAK (newdecl))
4139 {
4140 tree wd;
4141
4142 /* NEWDECL is weak, but OLDDECL is not. */
4143
4144 /* If we already output the OLDDECL, we're in trouble; we can't
4145 go back and make it weak. This error cannot caught in
4146 declare_weak because the NEWDECL and OLDDECL was not yet
4147 been merged; therefore, TREE_ASM_WRITTEN was not set. */
4148 if (TREE_ASM_WRITTEN (olddecl))
4149 error ("%Jweak declaration of '%D' must precede definition",
4150 newdecl, newdecl);
4151
4152 /* If we've already generated rtl referencing OLDDECL, we may
4153 have done so in a way that will not function properly with
4154 a weak symbol. */
4155 else if (TREE_USED (olddecl)
4156 && TREE_SYMBOL_REFERENCED (DECL_ASSEMBLER_NAME (olddecl)))
4157 warning ("%Jweak declaration of '%D' after first use results "
4158 "in unspecified behavior", newdecl, newdecl);
4159
4160 if (SUPPORTS_WEAK)
4161 {
4162 /* We put the NEWDECL on the weak_decls list at some point.
4163 Replace it with the OLDDECL. */
4164 for (wd = weak_decls; wd; wd = TREE_CHAIN (wd))
4165 if (TREE_VALUE (wd) == newdecl)
4166 {
4167 TREE_VALUE (wd) = olddecl;
4168 break;
4169 }
4170 /* We may not find the entry on the list. If NEWDECL is a
4171 weak alias, then we will have already called
4172 globalize_decl to remove the entry; in that case, we do
4173 not need to do anything. */
4174 }
4175
4176 /* Make the OLDDECL weak; it's OLDDECL that we'll be keeping. */
4177 mark_weak (olddecl);
4178 }
4179 else
4180 /* OLDDECL was weak, but NEWDECL was not explicitly marked as
4181 weak. Just update NEWDECL to indicate that it's weak too. */
4182 mark_weak (newdecl);
4183 }
4184
4185 /* Declare DECL to be a weak symbol. */
4186
4187 void
4188 declare_weak (tree decl)
4189 {
4190 if (! TREE_PUBLIC (decl))
4191 error ("%Jweak declaration of '%D' must be public", decl, decl);
4192 else if (TREE_CODE (decl) == FUNCTION_DECL && TREE_ASM_WRITTEN (decl))
4193 error ("%Jweak declaration of '%D' must precede definition", decl, decl);
4194 else if (SUPPORTS_WEAK)
4195 {
4196 if (! DECL_WEAK (decl))
4197 weak_decls = tree_cons (NULL, decl, weak_decls);
4198 }
4199 else
4200 warning ("%Jweak declaration of '%D' not supported", decl, decl);
4201
4202 mark_weak (decl);
4203 }
4204
4205 /* Emit any pending weak declarations. */
4206
4207 void
4208 weak_finish (void)
4209 {
4210 tree t;
4211
4212 for (t = weak_decls; t; t = TREE_CHAIN (t))
4213 {
4214 tree decl = TREE_VALUE (t);
4215 #if defined (ASM_WEAKEN_DECL) || defined (ASM_WEAKEN_LABEL)
4216 const char *const name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
4217 #endif
4218
4219 if (! TREE_USED (decl))
4220 continue;
4221
4222 #ifdef ASM_WEAKEN_DECL
4223 ASM_WEAKEN_DECL (asm_out_file, decl, name, NULL);
4224 #else
4225 #ifdef ASM_WEAKEN_LABEL
4226 ASM_WEAKEN_LABEL (asm_out_file, name);
4227 #else
4228 #ifdef ASM_OUTPUT_WEAK_ALIAS
4229 warning ("only weak aliases are supported in this configuration");
4230 return;
4231 #endif
4232 #endif
4233 #endif
4234 }
4235 }
4236
4237 /* Emit the assembly bits to indicate that DECL is globally visible. */
4238
4239 static void
4240 globalize_decl (tree decl)
4241 {
4242 const char *name = XSTR (XEXP (DECL_RTL (decl), 0), 0);
4243
4244 #if defined (ASM_WEAKEN_LABEL) || defined (ASM_WEAKEN_DECL)
4245 if (DECL_WEAK (decl))
4246 {
4247 tree *p, t;
4248
4249 #ifdef ASM_WEAKEN_DECL
4250 ASM_WEAKEN_DECL (asm_out_file, decl, name, 0);
4251 #else
4252 ASM_WEAKEN_LABEL (asm_out_file, name);
4253 #endif
4254
4255 /* Remove this function from the pending weak list so that
4256 we do not emit multiple .weak directives for it. */
4257 for (p = &weak_decls; (t = *p) ; )
4258 {
4259 if (DECL_ASSEMBLER_NAME (decl) == DECL_ASSEMBLER_NAME (TREE_VALUE (t)))
4260 *p = TREE_CHAIN (t);
4261 else
4262 p = &TREE_CHAIN (t);
4263 }
4264 return;
4265 }
4266 #elif defined(ASM_MAKE_LABEL_LINKONCE)
4267 if (DECL_ONE_ONLY (decl))
4268 ASM_MAKE_LABEL_LINKONCE (asm_out_file, name);
4269 #endif
4270
4271 targetm.asm_out.globalize_label (asm_out_file, name);
4272 }
4273
4274 /* Emit an assembler directive to make the symbol for DECL an alias to
4275 the symbol for TARGET. */
4276
4277 void
4278 assemble_alias (tree decl, tree target ATTRIBUTE_UNUSED)
4279 {
4280 const char *name;
4281
4282 /* We must force creation of DECL_RTL for debug info generation, even though
4283 we don't use it here. */
4284 make_decl_rtl (decl);
4285
4286 name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
4287
4288 #ifdef ASM_OUTPUT_DEF
4289 /* Make name accessible from other files, if appropriate. */
4290
4291 if (TREE_PUBLIC (decl))
4292 {
4293 globalize_decl (decl);
4294 maybe_assemble_visibility (decl);
4295 }
4296
4297 #ifdef ASM_OUTPUT_DEF_FROM_DECLS
4298 ASM_OUTPUT_DEF_FROM_DECLS (asm_out_file, decl, target);
4299 #else
4300 ASM_OUTPUT_DEF (asm_out_file, name, IDENTIFIER_POINTER (target));
4301 #endif
4302 #else /* !ASM_OUTPUT_DEF */
4303 #if defined (ASM_OUTPUT_WEAK_ALIAS) || defined (ASM_WEAKEN_DECL)
4304 if (DECL_WEAK (decl))
4305 {
4306 tree *p, t;
4307 #ifdef ASM_WEAKEN_DECL
4308 ASM_WEAKEN_DECL (asm_out_file, decl, name, IDENTIFIER_POINTER (target));
4309 #else
4310 ASM_OUTPUT_WEAK_ALIAS (asm_out_file, name, IDENTIFIER_POINTER (target));
4311 #endif
4312 /* Remove this function from the pending weak list so that
4313 we do not emit multiple .weak directives for it. */
4314 for (p = &weak_decls; (t = *p) ; )
4315 if (DECL_ASSEMBLER_NAME (decl)
4316 == DECL_ASSEMBLER_NAME (TREE_VALUE (t)))
4317 *p = TREE_CHAIN (t);
4318 else
4319 p = &TREE_CHAIN (t);
4320 }
4321 else
4322 warning ("only weak aliases are supported in this configuration");
4323
4324 #else
4325 warning ("alias definitions not supported in this configuration; ignored");
4326 #endif
4327 #endif
4328
4329 TREE_USED (decl) = 1;
4330 TREE_ASM_WRITTEN (decl) = 1;
4331 TREE_ASM_WRITTEN (DECL_ASSEMBLER_NAME (decl)) = 1;
4332 }
4333
4334 /* Emit an assembler directive to set symbol for DECL visibility to
4335 the visibility type VIS, which must not be VISIBILITY_DEFAULT. */
4336
4337 void
4338 default_assemble_visibility (tree decl, int vis)
4339 {
4340 static const char * const visibility_types[] = {
4341 NULL, "internal", "hidden", "protected"
4342 };
4343
4344 const char *name, *type;
4345
4346 name = (IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl)));
4347 type = visibility_types[vis];
4348
4349 #ifdef HAVE_GAS_HIDDEN
4350 fprintf (asm_out_file, "\t.%s\t", type);
4351 assemble_name (asm_out_file, name);
4352 fprintf (asm_out_file, "\n");
4353 #else
4354 warning ("visibility attribute not supported in this configuration; ignored");
4355 #endif
4356 }
4357
4358 /* A helper function to call assemble_visibility when needed for a decl. */
4359
4360 static void
4361 maybe_assemble_visibility (tree decl)
4362 {
4363 enum symbol_visibility vis = DECL_VISIBILITY (decl);
4364
4365 if (vis != VISIBILITY_DEFAULT)
4366 targetm.asm_out.visibility (decl, vis);
4367 }
4368
4369 /* Returns 1 if the target configuration supports defining public symbols
4370 so that one of them will be chosen at link time instead of generating a
4371 multiply-defined symbol error, whether through the use of weak symbols or
4372 a target-specific mechanism for having duplicates discarded. */
4373
4374 int
4375 supports_one_only (void)
4376 {
4377 if (SUPPORTS_ONE_ONLY)
4378 return 1;
4379 return SUPPORTS_WEAK;
4380 }
4381
4382 /* Set up DECL as a public symbol that can be defined in multiple
4383 translation units without generating a linker error. */
4384
4385 void
4386 make_decl_one_only (tree decl)
4387 {
4388 if (TREE_CODE (decl) != VAR_DECL && TREE_CODE (decl) != FUNCTION_DECL)
4389 abort ();
4390
4391 TREE_PUBLIC (decl) = 1;
4392
4393 if (SUPPORTS_ONE_ONLY)
4394 {
4395 #ifdef MAKE_DECL_ONE_ONLY
4396 MAKE_DECL_ONE_ONLY (decl);
4397 #endif
4398 DECL_ONE_ONLY (decl) = 1;
4399 }
4400 else if (TREE_CODE (decl) == VAR_DECL
4401 && (DECL_INITIAL (decl) == 0 || DECL_INITIAL (decl) == error_mark_node))
4402 DECL_COMMON (decl) = 1;
4403 else if (SUPPORTS_WEAK)
4404 DECL_WEAK (decl) = 1;
4405 else
4406 abort ();
4407 }
4408
4409 void
4410 init_varasm_once (void)
4411 {
4412 in_named_htab = htab_create_ggc (31, in_named_entry_hash,
4413 in_named_entry_eq, NULL);
4414 const_desc_htab = htab_create_ggc (1009, const_desc_hash,
4415 const_desc_eq, NULL);
4416
4417 const_alias_set = new_alias_set ();
4418 }
4419
4420 enum tls_model
4421 decl_tls_model (tree decl)
4422 {
4423 enum tls_model kind;
4424 tree attr = lookup_attribute ("tls_model", DECL_ATTRIBUTES (decl));
4425 bool is_local;
4426
4427 if (attr)
4428 {
4429 attr = TREE_VALUE (TREE_VALUE (attr));
4430 if (TREE_CODE (attr) != STRING_CST)
4431 abort ();
4432 if (!strcmp (TREE_STRING_POINTER (attr), "local-exec"))
4433 kind = TLS_MODEL_LOCAL_EXEC;
4434 else if (!strcmp (TREE_STRING_POINTER (attr), "initial-exec"))
4435 kind = TLS_MODEL_INITIAL_EXEC;
4436 else if (!strcmp (TREE_STRING_POINTER (attr), "local-dynamic"))
4437 kind = optimize ? TLS_MODEL_LOCAL_DYNAMIC : TLS_MODEL_GLOBAL_DYNAMIC;
4438 else if (!strcmp (TREE_STRING_POINTER (attr), "global-dynamic"))
4439 kind = TLS_MODEL_GLOBAL_DYNAMIC;
4440 else
4441 abort ();
4442 return kind;
4443 }
4444
4445 is_local = targetm.binds_local_p (decl);
4446 if (!flag_pic)
4447 {
4448 if (is_local)
4449 kind = TLS_MODEL_LOCAL_EXEC;
4450 else
4451 kind = TLS_MODEL_INITIAL_EXEC;
4452 }
4453 /* Local dynamic is inefficient when we're not combining the
4454 parts of the address. */
4455 else if (optimize && is_local)
4456 kind = TLS_MODEL_LOCAL_DYNAMIC;
4457 else
4458 kind = TLS_MODEL_GLOBAL_DYNAMIC;
4459 if (kind < flag_tls_default)
4460 kind = flag_tls_default;
4461
4462 return kind;
4463 }
4464
4465 /* Select a set of attributes for section NAME based on the properties
4466 of DECL and whether or not RELOC indicates that DECL's initializer
4467 might contain runtime relocations.
4468
4469 We make the section read-only and executable for a function decl,
4470 read-only for a const data decl, and writable for a non-const data decl. */
4471
4472 unsigned int
4473 default_section_type_flags (tree decl, const char *name, int reloc)
4474 {
4475 return default_section_type_flags_1 (decl, name, reloc, flag_pic);
4476 }
4477
4478 unsigned int
4479 default_section_type_flags_1 (tree decl, const char *name, int reloc,
4480 int shlib)
4481 {
4482 unsigned int flags;
4483
4484 if (decl && TREE_CODE (decl) == FUNCTION_DECL)
4485 flags = SECTION_CODE;
4486 else if (decl && decl_readonly_section_1 (decl, reloc, shlib))
4487 flags = 0;
4488 else if (strcmp (name, UNLIKELY_EXECUTED_TEXT_SECTION_NAME) == 0)
4489 flags = SECTION_CODE;
4490 else
4491 flags = SECTION_WRITE;
4492
4493 if (decl && DECL_ONE_ONLY (decl))
4494 flags |= SECTION_LINKONCE;
4495
4496 if (decl && TREE_CODE (decl) == VAR_DECL && DECL_THREAD_LOCAL (decl))
4497 flags |= SECTION_TLS | SECTION_WRITE;
4498
4499 if (strcmp (name, ".bss") == 0
4500 || strncmp (name, ".bss.", 5) == 0
4501 || strncmp (name, ".gnu.linkonce.b.", 16) == 0
4502 || strcmp (name, ".sbss") == 0
4503 || strncmp (name, ".sbss.", 6) == 0
4504 || strncmp (name, ".gnu.linkonce.sb.", 17) == 0
4505 || strcmp (name, ".tbss") == 0
4506 || strncmp (name, ".gnu.linkonce.tb.", 17) == 0)
4507 flags |= SECTION_BSS;
4508
4509 if (strcmp (name, ".tdata") == 0
4510 || strcmp (name, ".tbss") == 0
4511 || strncmp (name, ".gnu.linkonce.td.", 17) == 0
4512 || strncmp (name, ".gnu.linkonce.tb.", 17) == 0)
4513 flags |= SECTION_TLS;
4514
4515 /* These three sections have special ELF types. They are neither
4516 SHT_PROGBITS nor SHT_NOBITS, so when changing sections we don't
4517 want to print a section type (@progbits or @nobits). If someone
4518 is silly enough to emit code or TLS variables to one of these
4519 sections, then don't handle them specially. */
4520 if (!(flags & (SECTION_CODE | SECTION_BSS | SECTION_TLS))
4521 && (strcmp (name, ".init_array") == 0
4522 || strcmp (name, ".fini_array") == 0
4523 || strcmp (name, ".preinit_array") == 0))
4524 flags |= SECTION_NOTYPE;
4525
4526 return flags;
4527 }
4528
4529 /* Output assembly to switch to section NAME with attribute FLAGS.
4530 Four variants for common object file formats. */
4531
4532 void
4533 default_no_named_section (const char *name ATTRIBUTE_UNUSED,
4534 unsigned int flags ATTRIBUTE_UNUSED)
4535 {
4536 /* Some object formats don't support named sections at all. The
4537 front-end should already have flagged this as an error. */
4538 abort ();
4539 }
4540
4541 void
4542 default_elf_asm_named_section (const char *name, unsigned int flags)
4543 {
4544 char flagchars[10], *f = flagchars;
4545
4546 if (! named_section_first_declaration (name))
4547 {
4548 fprintf (asm_out_file, "\t.section\t%s\n", name);
4549 return;
4550 }
4551
4552 if (!(flags & SECTION_DEBUG))
4553 *f++ = 'a';
4554 if (flags & SECTION_WRITE)
4555 *f++ = 'w';
4556 if (flags & SECTION_CODE)
4557 *f++ = 'x';
4558 if (flags & SECTION_SMALL)
4559 *f++ = 's';
4560 if (flags & SECTION_MERGE)
4561 *f++ = 'M';
4562 if (flags & SECTION_STRINGS)
4563 *f++ = 'S';
4564 if (flags & SECTION_TLS)
4565 *f++ = 'T';
4566 *f = '\0';
4567
4568 fprintf (asm_out_file, "\t.section\t%s,\"%s\"", name, flagchars);
4569
4570 if (!(flags & SECTION_NOTYPE))
4571 {
4572 const char *type;
4573
4574 if (flags & SECTION_BSS)
4575 type = "nobits";
4576 else
4577 type = "progbits";
4578
4579 fprintf (asm_out_file, ",@%s", type);
4580
4581 if (flags & SECTION_ENTSIZE)
4582 fprintf (asm_out_file, ",%d", flags & SECTION_ENTSIZE);
4583 }
4584
4585 putc ('\n', asm_out_file);
4586 }
4587
4588 void
4589 default_coff_asm_named_section (const char *name, unsigned int flags)
4590 {
4591 char flagchars[8], *f = flagchars;
4592
4593 if (flags & SECTION_WRITE)
4594 *f++ = 'w';
4595 if (flags & SECTION_CODE)
4596 *f++ = 'x';
4597 *f = '\0';
4598
4599 fprintf (asm_out_file, "\t.section\t%s,\"%s\"\n", name, flagchars);
4600 }
4601
4602 void
4603 default_pe_asm_named_section (const char *name, unsigned int flags)
4604 {
4605 default_coff_asm_named_section (name, flags);
4606
4607 if (flags & SECTION_LINKONCE)
4608 {
4609 /* Functions may have been compiled at various levels of
4610 optimization so we can't use `same_size' here.
4611 Instead, have the linker pick one. */
4612 fprintf (asm_out_file, "\t.linkonce %s\n",
4613 (flags & SECTION_CODE ? "discard" : "same_size"));
4614 }
4615 }
4616 \f
4617 /* The lame default section selector. */
4618
4619 void
4620 default_select_section (tree decl, int reloc,
4621 unsigned HOST_WIDE_INT align ATTRIBUTE_UNUSED)
4622 {
4623 bool readonly = false;
4624
4625 if (DECL_P (decl))
4626 {
4627 if (decl_readonly_section (decl, reloc))
4628 readonly = true;
4629 }
4630 else if (TREE_CODE (decl) == CONSTRUCTOR)
4631 {
4632 if (! ((flag_pic && reloc)
4633 || !TREE_READONLY (decl)
4634 || TREE_SIDE_EFFECTS (decl)
4635 || !TREE_CONSTANT (decl)))
4636 readonly = true;
4637 }
4638 else if (TREE_CODE (decl) == STRING_CST)
4639 readonly = true;
4640 else if (! (flag_pic && reloc))
4641 readonly = true;
4642
4643 if (readonly)
4644 readonly_data_section ();
4645 else
4646 data_section ();
4647 }
4648
4649 /* A helper function for default_elf_select_section and
4650 default_elf_unique_section. Categorizes the DECL. */
4651
4652 enum section_category
4653 {
4654 SECCAT_TEXT,
4655
4656 SECCAT_RODATA,
4657 SECCAT_RODATA_MERGE_STR,
4658 SECCAT_RODATA_MERGE_STR_INIT,
4659 SECCAT_RODATA_MERGE_CONST,
4660 SECCAT_SRODATA,
4661
4662 SECCAT_DATA,
4663
4664 /* To optimize loading of shared programs, define following subsections
4665 of data section:
4666 _REL Contains data that has relocations, so they get grouped
4667 together and dynamic linker will visit fewer pages in memory.
4668 _RO Contains data that is otherwise read-only. This is useful
4669 with prelinking as most relocations won't be dynamically
4670 linked and thus stay read only.
4671 _LOCAL Marks data containing relocations only to local objects.
4672 These relocations will get fully resolved by prelinking. */
4673 SECCAT_DATA_REL,
4674 SECCAT_DATA_REL_LOCAL,
4675 SECCAT_DATA_REL_RO,
4676 SECCAT_DATA_REL_RO_LOCAL,
4677
4678 SECCAT_SDATA,
4679 SECCAT_TDATA,
4680
4681 SECCAT_BSS,
4682 SECCAT_SBSS,
4683 SECCAT_TBSS
4684 };
4685
4686 static enum section_category
4687 categorize_decl_for_section (tree, int, int);
4688
4689 static enum section_category
4690 categorize_decl_for_section (tree decl, int reloc, int shlib)
4691 {
4692 enum section_category ret;
4693
4694 if (TREE_CODE (decl) == FUNCTION_DECL)
4695 return SECCAT_TEXT;
4696 else if (TREE_CODE (decl) == STRING_CST)
4697 {
4698 if (flag_mudflap) /* or !flag_merge_constants */
4699 return SECCAT_RODATA;
4700 else
4701 return SECCAT_RODATA_MERGE_STR;
4702 }
4703 else if (TREE_CODE (decl) == VAR_DECL)
4704 {
4705 if (DECL_INITIAL (decl) == NULL
4706 || DECL_INITIAL (decl) == error_mark_node
4707 || (flag_zero_initialized_in_bss
4708 /* Leave constant zeroes in .rodata so they can be shared. */
4709 && !TREE_READONLY (decl)
4710 && initializer_zerop (DECL_INITIAL (decl))))
4711 ret = SECCAT_BSS;
4712 else if (! TREE_READONLY (decl)
4713 || TREE_SIDE_EFFECTS (decl)
4714 || ! TREE_CONSTANT (DECL_INITIAL (decl)))
4715 {
4716 if (shlib && (reloc & 2))
4717 ret = SECCAT_DATA_REL;
4718 else if (shlib && reloc)
4719 ret = SECCAT_DATA_REL_LOCAL;
4720 else
4721 ret = SECCAT_DATA;
4722 }
4723 else if (shlib && (reloc & 2))
4724 ret = SECCAT_DATA_REL_RO;
4725 else if (shlib && reloc)
4726 ret = SECCAT_DATA_REL_RO_LOCAL;
4727 else if (reloc || flag_merge_constants < 2)
4728 /* C and C++ don't allow different variables to share the same
4729 location. -fmerge-all-constants allows even that (at the
4730 expense of not conforming). */
4731 ret = SECCAT_RODATA;
4732 else if (TREE_CODE (DECL_INITIAL (decl)) == STRING_CST)
4733 ret = SECCAT_RODATA_MERGE_STR_INIT;
4734 else
4735 ret = SECCAT_RODATA_MERGE_CONST;
4736 }
4737 else if (TREE_CODE (decl) == CONSTRUCTOR)
4738 {
4739 if ((shlib && reloc)
4740 || TREE_SIDE_EFFECTS (decl)
4741 || ! TREE_CONSTANT (decl))
4742 ret = SECCAT_DATA;
4743 else
4744 ret = SECCAT_RODATA;
4745 }
4746 else
4747 ret = SECCAT_RODATA;
4748
4749 /* There are no read-only thread-local sections. */
4750 if (TREE_CODE (decl) == VAR_DECL && DECL_THREAD_LOCAL (decl))
4751 {
4752 /* Note that this would be *just* SECCAT_BSS, except that there's
4753 no concept of a read-only thread-local-data section. */
4754 if (ret == SECCAT_BSS
4755 || (flag_zero_initialized_in_bss
4756 && initializer_zerop (DECL_INITIAL (decl))))
4757 ret = SECCAT_TBSS;
4758 else
4759 ret = SECCAT_TDATA;
4760 }
4761
4762 /* If the target uses small data sections, select it. */
4763 else if (targetm.in_small_data_p (decl))
4764 {
4765 if (ret == SECCAT_BSS)
4766 ret = SECCAT_SBSS;
4767 else if (targetm.have_srodata_section && ret == SECCAT_RODATA)
4768 ret = SECCAT_SRODATA;
4769 else
4770 ret = SECCAT_SDATA;
4771 }
4772
4773 return ret;
4774 }
4775
4776 bool
4777 decl_readonly_section (tree decl, int reloc)
4778 {
4779 return decl_readonly_section_1 (decl, reloc, flag_pic);
4780 }
4781
4782 bool
4783 decl_readonly_section_1 (tree decl, int reloc, int shlib)
4784 {
4785 switch (categorize_decl_for_section (decl, reloc, shlib))
4786 {
4787 case SECCAT_RODATA:
4788 case SECCAT_RODATA_MERGE_STR:
4789 case SECCAT_RODATA_MERGE_STR_INIT:
4790 case SECCAT_RODATA_MERGE_CONST:
4791 case SECCAT_SRODATA:
4792 return true;
4793 break;
4794 default:
4795 return false;
4796 break;
4797 }
4798 }
4799
4800 /* Select a section based on the above categorization. */
4801
4802 void
4803 default_elf_select_section (tree decl, int reloc,
4804 unsigned HOST_WIDE_INT align)
4805 {
4806 default_elf_select_section_1 (decl, reloc, align, flag_pic);
4807 }
4808
4809 void
4810 default_elf_select_section_1 (tree decl, int reloc,
4811 unsigned HOST_WIDE_INT align, int shlib)
4812 {
4813 switch (categorize_decl_for_section (decl, reloc, shlib))
4814 {
4815 case SECCAT_TEXT:
4816 /* We're not supposed to be called on FUNCTION_DECLs. */
4817 abort ();
4818 case SECCAT_RODATA:
4819 readonly_data_section ();
4820 break;
4821 case SECCAT_RODATA_MERGE_STR:
4822 mergeable_string_section (decl, align, 0);
4823 break;
4824 case SECCAT_RODATA_MERGE_STR_INIT:
4825 mergeable_string_section (DECL_INITIAL (decl), align, 0);
4826 break;
4827 case SECCAT_RODATA_MERGE_CONST:
4828 mergeable_constant_section (DECL_MODE (decl), align, 0);
4829 break;
4830 case SECCAT_SRODATA:
4831 named_section (NULL_TREE, ".sdata2", reloc);
4832 break;
4833 case SECCAT_DATA:
4834 data_section ();
4835 break;
4836 case SECCAT_DATA_REL:
4837 named_section (NULL_TREE, ".data.rel", reloc);
4838 break;
4839 case SECCAT_DATA_REL_LOCAL:
4840 named_section (NULL_TREE, ".data.rel.local", reloc);
4841 break;
4842 case SECCAT_DATA_REL_RO:
4843 named_section (NULL_TREE, ".data.rel.ro", reloc);
4844 break;
4845 case SECCAT_DATA_REL_RO_LOCAL:
4846 named_section (NULL_TREE, ".data.rel.ro.local", reloc);
4847 break;
4848 case SECCAT_SDATA:
4849 named_section (NULL_TREE, ".sdata", reloc);
4850 break;
4851 case SECCAT_TDATA:
4852 named_section (NULL_TREE, ".tdata", reloc);
4853 break;
4854 case SECCAT_BSS:
4855 #ifdef BSS_SECTION_ASM_OP
4856 bss_section ();
4857 #else
4858 named_section (NULL_TREE, ".bss", reloc);
4859 #endif
4860 break;
4861 case SECCAT_SBSS:
4862 named_section (NULL_TREE, ".sbss", reloc);
4863 break;
4864 case SECCAT_TBSS:
4865 named_section (NULL_TREE, ".tbss", reloc);
4866 break;
4867 default:
4868 abort ();
4869 }
4870 }
4871
4872 /* Construct a unique section name based on the decl name and the
4873 categorization performed above. */
4874
4875 void
4876 default_unique_section (tree decl, int reloc)
4877 {
4878 default_unique_section_1 (decl, reloc, flag_pic);
4879 }
4880
4881 void
4882 default_unique_section_1 (tree decl, int reloc, int shlib)
4883 {
4884 bool one_only = DECL_ONE_ONLY (decl);
4885 const char *prefix, *name;
4886 size_t nlen, plen;
4887 char *string;
4888
4889 switch (categorize_decl_for_section (decl, reloc, shlib))
4890 {
4891 case SECCAT_TEXT:
4892 prefix = one_only ? ".gnu.linkonce.t." : ".text.";
4893 break;
4894 case SECCAT_RODATA:
4895 case SECCAT_RODATA_MERGE_STR:
4896 case SECCAT_RODATA_MERGE_STR_INIT:
4897 case SECCAT_RODATA_MERGE_CONST:
4898 prefix = one_only ? ".gnu.linkonce.r." : ".rodata.";
4899 break;
4900 case SECCAT_SRODATA:
4901 prefix = one_only ? ".gnu.linkonce.s2." : ".sdata2.";
4902 break;
4903 case SECCAT_DATA:
4904 case SECCAT_DATA_REL:
4905 case SECCAT_DATA_REL_LOCAL:
4906 case SECCAT_DATA_REL_RO:
4907 case SECCAT_DATA_REL_RO_LOCAL:
4908 prefix = one_only ? ".gnu.linkonce.d." : ".data.";
4909 break;
4910 case SECCAT_SDATA:
4911 prefix = one_only ? ".gnu.linkonce.s." : ".sdata.";
4912 break;
4913 case SECCAT_BSS:
4914 prefix = one_only ? ".gnu.linkonce.b." : ".bss.";
4915 break;
4916 case SECCAT_SBSS:
4917 prefix = one_only ? ".gnu.linkonce.sb." : ".sbss.";
4918 break;
4919 case SECCAT_TDATA:
4920 prefix = one_only ? ".gnu.linkonce.td." : ".tdata.";
4921 break;
4922 case SECCAT_TBSS:
4923 prefix = one_only ? ".gnu.linkonce.tb." : ".tbss.";
4924 break;
4925 default:
4926 abort ();
4927 }
4928 plen = strlen (prefix);
4929
4930 name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
4931 name = targetm.strip_name_encoding (name);
4932 nlen = strlen (name);
4933
4934 string = alloca (nlen + plen + 1);
4935 memcpy (string, prefix, plen);
4936 memcpy (string + plen, name, nlen + 1);
4937
4938 DECL_SECTION_NAME (decl) = build_string (nlen + plen, string);
4939 }
4940
4941 void
4942 default_select_rtx_section (enum machine_mode mode ATTRIBUTE_UNUSED,
4943 rtx x,
4944 unsigned HOST_WIDE_INT align ATTRIBUTE_UNUSED)
4945 {
4946 if (flag_pic)
4947 switch (GET_CODE (x))
4948 {
4949 case CONST:
4950 case SYMBOL_REF:
4951 case LABEL_REF:
4952 data_section ();
4953 return;
4954
4955 default:
4956 break;
4957 }
4958
4959 readonly_data_section ();
4960 }
4961
4962 void
4963 default_elf_select_rtx_section (enum machine_mode mode, rtx x,
4964 unsigned HOST_WIDE_INT align)
4965 {
4966 /* ??? Handle small data here somehow. */
4967
4968 if (flag_pic)
4969 switch (GET_CODE (x))
4970 {
4971 case CONST:
4972 case SYMBOL_REF:
4973 named_section (NULL_TREE, ".data.rel.ro", 3);
4974 return;
4975
4976 case LABEL_REF:
4977 named_section (NULL_TREE, ".data.rel.ro.local", 1);
4978 return;
4979
4980 default:
4981 break;
4982 }
4983
4984 mergeable_constant_section (mode, align, 0);
4985 }
4986
4987 /* Set the generally applicable flags on the SYMBOL_REF for EXP. */
4988
4989 void
4990 default_encode_section_info (tree decl, rtx rtl, int first ATTRIBUTE_UNUSED)
4991 {
4992 rtx symbol;
4993 int flags;
4994
4995 /* Careful not to prod global register variables. */
4996 if (!MEM_P (rtl))
4997 return;
4998 symbol = XEXP (rtl, 0);
4999 if (GET_CODE (symbol) != SYMBOL_REF)
5000 return;
5001
5002 flags = 0;
5003 if (TREE_CODE (decl) == FUNCTION_DECL)
5004 flags |= SYMBOL_FLAG_FUNCTION;
5005 if (targetm.binds_local_p (decl))
5006 flags |= SYMBOL_FLAG_LOCAL;
5007 if (targetm.in_small_data_p (decl))
5008 flags |= SYMBOL_FLAG_SMALL;
5009 if (TREE_CODE (decl) == VAR_DECL && DECL_THREAD_LOCAL (decl))
5010 flags |= decl_tls_model (decl) << SYMBOL_FLAG_TLS_SHIFT;
5011 /* ??? Why is DECL_EXTERNAL ever set for non-PUBLIC names? Without
5012 being PUBLIC, the thing *must* be defined in this translation unit.
5013 Prevent this buglet from being propagated into rtl code as well. */
5014 if (DECL_P (decl) && DECL_EXTERNAL (decl) && TREE_PUBLIC (decl))
5015 flags |= SYMBOL_FLAG_EXTERNAL;
5016
5017 SYMBOL_REF_FLAGS (symbol) = flags;
5018 }
5019
5020 /* By default, we do nothing for encode_section_info, so we need not
5021 do anything but discard the '*' marker. */
5022
5023 const char *
5024 default_strip_name_encoding (const char *str)
5025 {
5026 return str + (*str == '*');
5027 }
5028
5029 /* Assume ELF-ish defaults, since that's pretty much the most liberal
5030 wrt cross-module name binding. */
5031
5032 bool
5033 default_binds_local_p (tree exp)
5034 {
5035 return default_binds_local_p_1 (exp, flag_shlib);
5036 }
5037
5038 bool
5039 default_binds_local_p_1 (tree exp, int shlib)
5040 {
5041 bool local_p;
5042
5043 /* A non-decl is an entry in the constant pool. */
5044 if (!DECL_P (exp))
5045 local_p = true;
5046 /* Static variables are always local. */
5047 else if (! TREE_PUBLIC (exp))
5048 local_p = true;
5049 /* A variable is local if the user explicitly tells us so. */
5050 else if (DECL_VISIBILITY_SPECIFIED (exp) && DECL_VISIBILITY (exp) != VISIBILITY_DEFAULT)
5051 local_p = true;
5052 /* Otherwise, variables defined outside this object may not be local. */
5053 else if (DECL_EXTERNAL (exp))
5054 local_p = false;
5055 /* Linkonce and weak data are never local. */
5056 else if (DECL_ONE_ONLY (exp) || DECL_WEAK (exp))
5057 local_p = false;
5058 /* If none of the above and visibility is not default, make local. */
5059 else if (DECL_VISIBILITY (exp) != VISIBILITY_DEFAULT)
5060 local_p = true;
5061 /* If PIC, then assume that any global name can be overridden by
5062 symbols resolved from other modules. */
5063 else if (shlib)
5064 local_p = false;
5065 /* Uninitialized COMMON variable may be unified with symbols
5066 resolved from other modules. */
5067 else if (DECL_COMMON (exp)
5068 && (DECL_INITIAL (exp) == NULL
5069 || DECL_INITIAL (exp) == error_mark_node))
5070 local_p = false;
5071 /* Otherwise we're left with initialized (or non-common) global data
5072 which is of necessity defined locally. */
5073 else
5074 local_p = true;
5075
5076 return local_p;
5077 }
5078
5079 /* Determine whether or not a pointer mode is valid. Assume defaults
5080 of ptr_mode or Pmode - can be overridden. */
5081 bool
5082 default_valid_pointer_mode (enum machine_mode mode)
5083 {
5084 return (mode == ptr_mode || mode == Pmode);
5085 }
5086
5087 /* Default function to output code that will globalize a label. A
5088 target must define GLOBAL_ASM_OP or provide it's own function to
5089 globalize a label. */
5090 #ifdef GLOBAL_ASM_OP
5091 void
5092 default_globalize_label (FILE * stream, const char *name)
5093 {
5094 fputs (GLOBAL_ASM_OP, stream);
5095 assemble_name (stream, name);
5096 putc ('\n', stream);
5097 }
5098 #endif /* GLOBAL_ASM_OP */
5099
5100 /* Default function to output a label for unwind information. The
5101 default is to do nothing. A target that needs nonlocal labels for
5102 unwind information must provide its own function to do this. */
5103 void
5104 default_emit_unwind_label (FILE * stream ATTRIBUTE_UNUSED,
5105 tree decl ATTRIBUTE_UNUSED,
5106 int for_eh ATTRIBUTE_UNUSED,
5107 int empty ATTRIBUTE_UNUSED)
5108 {
5109 }
5110
5111 /* This is how to output an internal numbered label where PREFIX is
5112 the class of label and LABELNO is the number within the class. */
5113
5114 void
5115 default_internal_label (FILE *stream, const char *prefix,
5116 unsigned long labelno)
5117 {
5118 char *const buf = alloca (40 + strlen (prefix));
5119 ASM_GENERATE_INTERNAL_LABEL (buf, prefix, labelno);
5120 ASM_OUTPUT_LABEL (stream, buf);
5121 }
5122
5123 /* This is the default behavior at the beginning of a file. It's
5124 controlled by two other target-hook toggles. */
5125 void
5126 default_file_start (void)
5127 {
5128 if (targetm.file_start_app_off && !flag_verbose_asm)
5129 fputs (ASM_APP_OFF, asm_out_file);
5130
5131 if (targetm.file_start_file_directive)
5132 output_file_directive (asm_out_file, main_input_filename);
5133 }
5134
5135 /* This is a generic routine suitable for use as TARGET_ASM_FILE_END
5136 which emits a special section directive used to indicate whether or
5137 not this object file needs an executable stack. This is primarily
5138 a GNU extension to ELF but could be used on other targets. */
5139
5140 int trampolines_created;
5141
5142 void
5143 file_end_indicate_exec_stack (void)
5144 {
5145 unsigned int flags = SECTION_DEBUG;
5146 if (trampolines_created)
5147 flags |= SECTION_CODE;
5148
5149 named_section_flags (".note.GNU-stack", flags);
5150 }
5151
5152 #include "gt-varasm.h"