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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 static 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 static 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 static char *unlikely_text_section_name = NULL;
120
121 /* We give all constants their own alias set. Perhaps redundant with
122 MEM_READONLY_P, but pre-dates it. */
123
124 static HOST_WIDE_INT const_alias_set;
125
126 static const char *strip_reg_name (const char *);
127 static int contains_pointers_p (tree);
128 #ifdef ASM_OUTPUT_EXTERNAL
129 static bool incorporeal_function_p (tree);
130 #endif
131 static void decode_addr_const (tree, struct addr_const *);
132 static hashval_t const_desc_hash (const void *);
133 static int const_desc_eq (const void *, const void *);
134 static hashval_t const_hash_1 (const tree);
135 static int compare_constant (const tree, const tree);
136 static tree copy_constant (tree);
137 static void output_constant_def_contents (rtx);
138 static void output_addressed_constants (tree);
139 static unsigned HOST_WIDE_INT array_size_for_constructor (tree);
140 static unsigned min_align (unsigned, unsigned);
141 static void output_constructor (tree, unsigned HOST_WIDE_INT, unsigned int);
142 static void globalize_decl (tree);
143 static void maybe_assemble_visibility (tree);
144 static int in_named_entry_eq (const void *, const void *);
145 static hashval_t in_named_entry_hash (const void *);
146 #ifdef BSS_SECTION_ASM_OP
147 #ifdef ASM_OUTPUT_BSS
148 static void asm_output_bss (FILE *, tree, const char *,
149 unsigned HOST_WIDE_INT, unsigned HOST_WIDE_INT);
150 #endif
151 #ifdef ASM_OUTPUT_ALIGNED_BSS
152 static void asm_output_aligned_bss (FILE *, tree, const char *,
153 unsigned HOST_WIDE_INT, int)
154 ATTRIBUTE_UNUSED;
155 #endif
156 #endif /* BSS_SECTION_ASM_OP */
157 static bool asm_emit_uninitialised (tree, const char*,
158 unsigned HOST_WIDE_INT,
159 unsigned HOST_WIDE_INT);
160 static void mark_weak (tree);
161 \f
162 enum in_section { no_section, in_text, in_unlikely_executed_text, in_data,
163 in_named
164 #ifdef BSS_SECTION_ASM_OP
165 , in_bss
166 #endif
167 #ifdef CTORS_SECTION_ASM_OP
168 , in_ctors
169 #endif
170 #ifdef DTORS_SECTION_ASM_OP
171 , in_dtors
172 #endif
173 #ifdef READONLY_DATA_SECTION_ASM_OP
174 , in_readonly_data
175 #endif
176 #ifdef EXTRA_SECTIONS
177 , EXTRA_SECTIONS
178 #endif
179 };
180 static GTY(()) enum in_section in_section = no_section;
181
182 /* Return a nonzero value if DECL has a section attribute. */
183 #ifndef IN_NAMED_SECTION
184 #define IN_NAMED_SECTION(DECL) \
185 ((TREE_CODE (DECL) == FUNCTION_DECL || TREE_CODE (DECL) == VAR_DECL) \
186 && DECL_SECTION_NAME (DECL) != NULL_TREE)
187 #endif
188
189 /* Text of section name when in_section == in_named. */
190 static GTY(()) const char *in_named_name;
191
192 /* Hash table of flags that have been used for a particular named section. */
193
194 struct in_named_entry GTY(())
195 {
196 const char *name;
197 unsigned int flags;
198 bool declared;
199 };
200
201 static GTY((param_is (struct in_named_entry))) htab_t in_named_htab;
202
203 /* Define functions like text_section for any extra sections. */
204 #ifdef EXTRA_SECTION_FUNCTIONS
205 EXTRA_SECTION_FUNCTIONS
206 #endif
207
208 /* Tell assembler to switch to text section. */
209
210 void
211 text_section (void)
212 {
213 if (in_section != in_text)
214 {
215 in_section = in_text;
216 fprintf (asm_out_file, "%s\n", TEXT_SECTION_ASM_OP);
217 }
218 }
219
220 /* Tell assembler to switch to unlikely-to-be-executed text section. */
221
222 void
223 unlikely_text_section (void)
224 {
225 const char *name;
226 int len;
227
228 if (! unlikely_text_section_name)
229 {
230 if (DECL_SECTION_NAME (current_function_decl)
231 && (strcmp (TREE_STRING_POINTER (DECL_SECTION_NAME
232 (current_function_decl)),
233 HOT_TEXT_SECTION_NAME) != 0)
234 && (strcmp (TREE_STRING_POINTER (DECL_SECTION_NAME
235 (current_function_decl)),
236 UNLIKELY_EXECUTED_TEXT_SECTION_NAME) != 0))
237 {
238 name = TREE_STRING_POINTER (DECL_SECTION_NAME
239 (current_function_decl));
240 len = strlen (name);
241 unlikely_text_section_name = xmalloc ((len + 10) * sizeof (char));
242 strcpy (unlikely_text_section_name, name);
243 strcat (unlikely_text_section_name, "_unlikely");
244 }
245 else
246 {
247 len = strlen (UNLIKELY_EXECUTED_TEXT_SECTION_NAME);
248 unlikely_text_section_name = xmalloc (len+1 * sizeof (char));
249 strcpy (unlikely_text_section_name,
250 UNLIKELY_EXECUTED_TEXT_SECTION_NAME);
251 }
252 }
253
254 if ((in_section != in_unlikely_executed_text)
255 && (in_section != in_named
256 || strcmp (in_named_name, unlikely_text_section_name) != 0))
257 {
258 named_section (NULL_TREE, unlikely_text_section_name, 0);
259 in_section = in_unlikely_executed_text;
260
261 if (!unlikely_section_label_printed)
262 {
263 ASM_OUTPUT_LABEL (asm_out_file, unlikely_section_label);
264 unlikely_section_label_printed = true;
265 }
266 }
267 }
268
269 /* Tell assembler to switch to data section. */
270
271 void
272 data_section (void)
273 {
274 if (in_section != in_data)
275 {
276 in_section = in_data;
277 fprintf (asm_out_file, "%s\n", DATA_SECTION_ASM_OP);
278 }
279 }
280
281 /* Tell assembler to switch to read-only data section. This is normally
282 the text section. */
283
284 void
285 readonly_data_section (void)
286 {
287 #ifdef READONLY_DATA_SECTION
288 READONLY_DATA_SECTION (); /* Note this can call data_section. */
289 #else
290 #ifdef READONLY_DATA_SECTION_ASM_OP
291 if (in_section != in_readonly_data)
292 {
293 in_section = in_readonly_data;
294 fputs (READONLY_DATA_SECTION_ASM_OP, asm_out_file);
295 fputc ('\n', asm_out_file);
296 }
297 #else
298 text_section ();
299 #endif
300 #endif
301 }
302
303 /* Determine if we're in the text section. */
304
305 int
306 in_text_section (void)
307 {
308 return in_section == in_text;
309 }
310
311 /* Determine if we're in the unlikely-to-be-executed text section. */
312
313 int
314 in_unlikely_text_section (void)
315 {
316 bool ret_val;
317
318 ret_val = ((in_section == in_unlikely_executed_text)
319 || (in_section == in_named
320 && unlikely_text_section_name
321 && strcmp (in_named_name, unlikely_text_section_name) == 0));
322
323 return ret_val;
324 }
325
326 /* Determine if we're in the data section. */
327
328 int
329 in_data_section (void)
330 {
331 return in_section == in_data;
332 }
333
334 /* Helper routines for maintaining in_named_htab. */
335
336 static int
337 in_named_entry_eq (const void *p1, const void *p2)
338 {
339 const struct in_named_entry *old = p1;
340 const char *new = p2;
341
342 return strcmp (old->name, new) == 0;
343 }
344
345 static hashval_t
346 in_named_entry_hash (const void *p)
347 {
348 const struct in_named_entry *old = p;
349 return htab_hash_string (old->name);
350 }
351
352 /* If SECTION has been seen before as a named section, return the flags
353 that were used. Otherwise, return 0. Note, that 0 is a perfectly valid
354 set of flags for a section to have, so 0 does not mean that the section
355 has not been seen. */
356
357 unsigned int
358 get_named_section_flags (const char *section)
359 {
360 struct in_named_entry **slot;
361
362 slot = (struct in_named_entry **)
363 htab_find_slot_with_hash (in_named_htab, section,
364 htab_hash_string (section), NO_INSERT);
365
366 return slot ? (*slot)->flags : 0;
367 }
368
369 /* Returns true if the section has been declared before. Sets internal
370 flag on this section in in_named_hash so subsequent calls on this
371 section will return false. */
372
373 bool
374 named_section_first_declaration (const char *name)
375 {
376 struct in_named_entry **slot;
377
378 slot = (struct in_named_entry **)
379 htab_find_slot_with_hash (in_named_htab, name,
380 htab_hash_string (name), NO_INSERT);
381 if (! (*slot)->declared)
382 {
383 (*slot)->declared = true;
384 return true;
385 }
386 else
387 {
388 return false;
389 }
390 }
391
392
393 /* Record FLAGS for SECTION. If SECTION was previously recorded with a
394 different set of flags, return false. */
395
396 bool
397 set_named_section_flags (const char *section, unsigned int flags)
398 {
399 struct in_named_entry **slot, *entry;
400
401 slot = (struct in_named_entry **)
402 htab_find_slot_with_hash (in_named_htab, section,
403 htab_hash_string (section), INSERT);
404 entry = *slot;
405
406 if (!entry)
407 {
408 entry = ggc_alloc (sizeof (*entry));
409 *slot = entry;
410 entry->name = ggc_strdup (section);
411 entry->flags = flags;
412 entry->declared = false;
413 }
414 else if (entry->flags != flags)
415 return false;
416
417 return true;
418 }
419
420 /* Tell assembler to change to section NAME with attributes FLAGS. If
421 DECL is non-NULL, it is the VAR_DECL or FUNCTION_DECL with which
422 this section is associated. */
423
424 void
425 named_section_real (const char *name, unsigned int flags, tree decl)
426 {
427 if (in_section != in_named || strcmp (name, in_named_name) != 0)
428 {
429 if (! set_named_section_flags (name, flags))
430 abort ();
431
432 targetm.asm_out.named_section (name, flags, decl);
433
434 if (flags & SECTION_FORGET)
435 in_section = no_section;
436 else
437 {
438 in_named_name = ggc_strdup (name);
439 in_section = in_named;
440 }
441 }
442 }
443
444 /* Tell assembler to change to section NAME for DECL.
445 If DECL is NULL, just switch to section NAME.
446 If NAME is NULL, get the name from DECL.
447 If RELOC is 1, the initializer for DECL contains relocs. */
448
449 void
450 named_section (tree decl, const char *name, int reloc)
451 {
452 unsigned int flags;
453
454 if (decl != NULL_TREE && !DECL_P (decl))
455 abort ();
456 if (name == NULL)
457 name = TREE_STRING_POINTER (DECL_SECTION_NAME (decl));
458
459 if (strcmp (name, UNLIKELY_EXECUTED_TEXT_SECTION_NAME) == 0
460 && !unlikely_text_section_name)
461 {
462 unlikely_text_section_name = xmalloc
463 (strlen (UNLIKELY_EXECUTED_TEXT_SECTION_NAME) + 1
464 * sizeof (char));
465 strcpy (unlikely_text_section_name,
466 UNLIKELY_EXECUTED_TEXT_SECTION_NAME);
467 }
468
469 flags = targetm.section_type_flags (decl, name, reloc);
470
471 /* Sanity check user variables for flag changes. Non-user
472 section flag changes will abort in named_section_flags.
473 However, don't complain if SECTION_OVERRIDE is set.
474 We trust that the setter knows that it is safe to ignore
475 the default flags for this decl. */
476 if (decl && ! set_named_section_flags (name, flags))
477 {
478 flags = get_named_section_flags (name);
479 if ((flags & SECTION_OVERRIDE) == 0)
480 error ("%J%D causes a section type conflict", decl, decl);
481 }
482
483 named_section_real (name, flags, decl);
484 }
485
486 /* If required, set DECL_SECTION_NAME to a unique name. */
487
488 void
489 resolve_unique_section (tree decl, int reloc ATTRIBUTE_UNUSED,
490 int flag_function_or_data_sections)
491 {
492 if (DECL_SECTION_NAME (decl) == NULL_TREE
493 && targetm.have_named_sections
494 && (flag_function_or_data_sections
495 || DECL_ONE_ONLY (decl)))
496 targetm.asm_out.unique_section (decl, reloc);
497 }
498
499 #ifdef BSS_SECTION_ASM_OP
500
501 /* Tell the assembler to switch to the bss section. */
502
503 void
504 bss_section (void)
505 {
506 if (in_section != in_bss)
507 {
508 fprintf (asm_out_file, "%s\n", BSS_SECTION_ASM_OP);
509 in_section = in_bss;
510 }
511 }
512
513 #ifdef ASM_OUTPUT_BSS
514
515 /* Utility function for ASM_OUTPUT_BSS for targets to use if
516 they don't support alignments in .bss.
517 ??? It is believed that this function will work in most cases so such
518 support is localized here. */
519
520 static void
521 asm_output_bss (FILE *file, tree decl ATTRIBUTE_UNUSED,
522 const char *name,
523 unsigned HOST_WIDE_INT size ATTRIBUTE_UNUSED,
524 unsigned HOST_WIDE_INT rounded)
525 {
526 targetm.asm_out.globalize_label (file, name);
527 bss_section ();
528 #ifdef ASM_DECLARE_OBJECT_NAME
529 last_assemble_variable_decl = decl;
530 ASM_DECLARE_OBJECT_NAME (file, name, decl);
531 #else
532 /* Standard thing is just output label for the object. */
533 ASM_OUTPUT_LABEL (file, name);
534 #endif /* ASM_DECLARE_OBJECT_NAME */
535 ASM_OUTPUT_SKIP (file, rounded ? rounded : 1);
536 }
537
538 #endif
539
540 #ifdef ASM_OUTPUT_ALIGNED_BSS
541
542 /* Utility function for targets to use in implementing
543 ASM_OUTPUT_ALIGNED_BSS.
544 ??? It is believed that this function will work in most cases so such
545 support is localized here. */
546
547 static void
548 asm_output_aligned_bss (FILE *file, tree decl ATTRIBUTE_UNUSED,
549 const char *name, unsigned HOST_WIDE_INT size,
550 int align)
551 {
552 bss_section ();
553 ASM_OUTPUT_ALIGN (file, floor_log2 (align / BITS_PER_UNIT));
554 #ifdef ASM_DECLARE_OBJECT_NAME
555 last_assemble_variable_decl = decl;
556 ASM_DECLARE_OBJECT_NAME (file, name, decl);
557 #else
558 /* Standard thing is just output label for the object. */
559 ASM_OUTPUT_LABEL (file, name);
560 #endif /* ASM_DECLARE_OBJECT_NAME */
561 ASM_OUTPUT_SKIP (file, size ? size : 1);
562 }
563
564 #endif
565
566 #endif /* BSS_SECTION_ASM_OP */
567
568 /* Switch to the section for function DECL.
569
570 If DECL is NULL_TREE, switch to the text section.
571 ??? It's not clear that we will ever be passed NULL_TREE, but it's
572 safer to handle it. */
573
574 void
575 function_section (tree decl)
576 {
577 if (scan_ahead_for_unlikely_executed_note (get_insns()))
578 unlikely_text_section ();
579 else if (decl != NULL_TREE
580 && DECL_SECTION_NAME (decl) != NULL_TREE)
581 named_section (decl, (char *) 0, 0);
582 else
583 text_section ();
584 }
585
586 /* Switch to read-only data section associated with function DECL. */
587
588 void
589 default_function_rodata_section (tree decl)
590 {
591 if (decl != NULL_TREE && DECL_SECTION_NAME (decl))
592 {
593 const char *name = TREE_STRING_POINTER (DECL_SECTION_NAME (decl));
594
595 /* For .gnu.linkonce.t.foo we want to use .gnu.linkonce.r.foo. */
596 if (DECL_ONE_ONLY (decl) && strncmp (name, ".gnu.linkonce.t.", 16) == 0)
597 {
598 size_t len = strlen (name) + 1;
599 char *rname = alloca (len);
600
601 memcpy (rname, name, len);
602 rname[14] = 'r';
603 named_section_flags (rname, SECTION_LINKONCE);
604 return;
605 }
606 /* For .text.foo we want to use .rodata.foo. */
607 else if (flag_function_sections && flag_data_sections
608 && strncmp (name, ".text.", 6) == 0)
609 {
610 size_t len = strlen (name) + 1;
611 char *rname = alloca (len + 2);
612
613 memcpy (rname, ".rodata", 7);
614 memcpy (rname + 7, name + 5, len - 5);
615 named_section_flags (rname, 0);
616 return;
617 }
618 }
619
620 readonly_data_section ();
621 }
622
623 /* Switch to read-only data section associated with function DECL
624 for targets where that section should be always the single
625 readonly data section. */
626
627 void
628 default_no_function_rodata_section (tree decl ATTRIBUTE_UNUSED)
629 {
630 readonly_data_section ();
631 }
632
633 /* Switch to section for variable DECL. RELOC is the same as the
634 argument to SELECT_SECTION. */
635
636 void
637 variable_section (tree decl, int reloc)
638 {
639 if (IN_NAMED_SECTION (decl))
640 named_section (decl, NULL, reloc);
641 else
642 targetm.asm_out.select_section (decl, reloc, DECL_ALIGN (decl));
643 }
644
645 /* Tell assembler to switch to the section for string merging. */
646
647 void
648 mergeable_string_section (tree decl ATTRIBUTE_UNUSED,
649 unsigned HOST_WIDE_INT align ATTRIBUTE_UNUSED,
650 unsigned int flags ATTRIBUTE_UNUSED)
651 {
652 if (HAVE_GAS_SHF_MERGE && flag_merge_constants
653 && TREE_CODE (decl) == STRING_CST
654 && TREE_CODE (TREE_TYPE (decl)) == ARRAY_TYPE
655 && align <= 256
656 && TREE_STRING_LENGTH (decl) >= int_size_in_bytes (TREE_TYPE (decl)))
657 {
658 enum machine_mode mode;
659 unsigned int modesize;
660 const char *str;
661 int i, j, len, unit;
662 char name[30];
663
664 mode = TYPE_MODE (TREE_TYPE (TREE_TYPE (decl)));
665 modesize = GET_MODE_BITSIZE (mode);
666 if (modesize >= 8 && modesize <= 256
667 && (modesize & (modesize - 1)) == 0)
668 {
669 if (align < modesize)
670 align = modesize;
671
672 str = TREE_STRING_POINTER (decl);
673 len = TREE_STRING_LENGTH (decl);
674 unit = GET_MODE_SIZE (mode);
675
676 /* Check for embedded NUL characters. */
677 for (i = 0; i < len; i += unit)
678 {
679 for (j = 0; j < unit; j++)
680 if (str[i + j] != '\0')
681 break;
682 if (j == unit)
683 break;
684 }
685 if (i == len - unit)
686 {
687 sprintf (name, ".rodata.str%d.%d", modesize / 8,
688 (int) (align / 8));
689 flags |= (modesize / 8) | SECTION_MERGE | SECTION_STRINGS;
690 if (!i && modesize < align)
691 {
692 /* A "" string with requested alignment greater than
693 character size might cause a problem:
694 if some other string required even bigger
695 alignment than "", then linker might think the
696 "" is just part of padding after some other string
697 and not put it into the hash table initially.
698 But this means "" could have smaller alignment
699 than requested. */
700 #ifdef ASM_OUTPUT_SECTION_START
701 named_section_flags (name, flags);
702 ASM_OUTPUT_SECTION_START (asm_out_file);
703 #else
704 readonly_data_section ();
705 #endif
706 return;
707 }
708
709 named_section_flags (name, flags);
710 return;
711 }
712 }
713 }
714
715 readonly_data_section ();
716 }
717
718 /* Tell assembler to switch to the section for constant merging. */
719
720 void
721 mergeable_constant_section (enum machine_mode mode ATTRIBUTE_UNUSED,
722 unsigned HOST_WIDE_INT align ATTRIBUTE_UNUSED,
723 unsigned int flags ATTRIBUTE_UNUSED)
724 {
725 unsigned int modesize = GET_MODE_BITSIZE (mode);
726
727 if (HAVE_GAS_SHF_MERGE && flag_merge_constants
728 && mode != VOIDmode
729 && mode != BLKmode
730 && modesize <= align
731 && align >= 8
732 && align <= 256
733 && (align & (align - 1)) == 0)
734 {
735 char name[24];
736
737 sprintf (name, ".rodata.cst%d", (int) (align / 8));
738 flags |= (align / 8) | SECTION_MERGE;
739 named_section_flags (name, flags);
740 return;
741 }
742
743 readonly_data_section ();
744 }
745 \f
746 /* Given NAME, a putative register name, discard any customary prefixes. */
747
748 static const char *
749 strip_reg_name (const char *name)
750 {
751 #ifdef REGISTER_PREFIX
752 if (!strncmp (name, REGISTER_PREFIX, strlen (REGISTER_PREFIX)))
753 name += strlen (REGISTER_PREFIX);
754 #endif
755 if (name[0] == '%' || name[0] == '#')
756 name++;
757 return name;
758 }
759 \f
760 /* The user has asked for a DECL to have a particular name. Set (or
761 change) it in such a way that we don't prefix an underscore to
762 it. */
763 void
764 set_user_assembler_name (tree decl, const char *name)
765 {
766 char *starred = alloca (strlen (name) + 2);
767 starred[0] = '*';
768 strcpy (starred + 1, name);
769 change_decl_assembler_name (decl, get_identifier (starred));
770 SET_DECL_RTL (decl, NULL_RTX);
771 }
772 \f
773 /* Decode an `asm' spec for a declaration as a register name.
774 Return the register number, or -1 if nothing specified,
775 or -2 if the ASMSPEC is not `cc' or `memory' and is not recognized,
776 or -3 if ASMSPEC is `cc' and is not recognized,
777 or -4 if ASMSPEC is `memory' and is not recognized.
778 Accept an exact spelling or a decimal number.
779 Prefixes such as % are optional. */
780
781 int
782 decode_reg_name (const char *asmspec)
783 {
784 if (asmspec != 0 && strlen (asmspec) != 0)
785 {
786 int i;
787
788 /* Get rid of confusing prefixes. */
789 asmspec = strip_reg_name (asmspec);
790
791 /* Allow a decimal number as a "register name". */
792 for (i = strlen (asmspec) - 1; i >= 0; i--)
793 if (! ISDIGIT (asmspec[i]))
794 break;
795 if (asmspec[0] != 0 && i < 0)
796 {
797 i = atoi (asmspec);
798 if (i < FIRST_PSEUDO_REGISTER && i >= 0)
799 return i;
800 else
801 return -2;
802 }
803
804 for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
805 if (reg_names[i][0]
806 && ! strcmp (asmspec, strip_reg_name (reg_names[i])))
807 return i;
808
809 #ifdef ADDITIONAL_REGISTER_NAMES
810 {
811 static const struct { const char *const name; const int number; } table[]
812 = ADDITIONAL_REGISTER_NAMES;
813
814 for (i = 0; i < (int) ARRAY_SIZE (table); i++)
815 if (! strcmp (asmspec, table[i].name))
816 return table[i].number;
817 }
818 #endif /* ADDITIONAL_REGISTER_NAMES */
819
820 if (!strcmp (asmspec, "memory"))
821 return -4;
822
823 if (!strcmp (asmspec, "cc"))
824 return -3;
825
826 return -2;
827 }
828
829 return -1;
830 }
831 \f
832 /* Create the DECL_RTL for a VAR_DECL or FUNCTION_DECL. DECL should
833 have static storage duration. In other words, it should not be an
834 automatic variable, including PARM_DECLs.
835
836 There is, however, one exception: this function handles variables
837 explicitly placed in a particular register by the user.
838
839 This is never called for PARM_DECL nodes. */
840
841 void
842 make_decl_rtl (tree decl)
843 {
844 const char *name = 0;
845 int reg_number;
846 rtx x;
847
848 /* Check that we are not being given an automatic variable. */
849 /* A weak alias has TREE_PUBLIC set but not the other bits. */
850 if (TREE_CODE (decl) == PARM_DECL
851 || TREE_CODE (decl) == RESULT_DECL
852 || (TREE_CODE (decl) == VAR_DECL
853 && !TREE_STATIC (decl)
854 && !TREE_PUBLIC (decl)
855 && !DECL_EXTERNAL (decl)
856 && !DECL_REGISTER (decl)))
857 abort ();
858 /* And that we were not given a type or a label. */
859 else if (TREE_CODE (decl) == TYPE_DECL
860 || TREE_CODE (decl) == LABEL_DECL)
861 abort ();
862
863 /* For a duplicate declaration, we can be called twice on the
864 same DECL node. Don't discard the RTL already made. */
865 if (DECL_RTL_SET_P (decl))
866 {
867 /* If the old RTL had the wrong mode, fix the mode. */
868 if (GET_MODE (DECL_RTL (decl)) != DECL_MODE (decl))
869 SET_DECL_RTL (decl, adjust_address_nv (DECL_RTL (decl),
870 DECL_MODE (decl), 0));
871
872 if (TREE_CODE (decl) != FUNCTION_DECL && DECL_REGISTER (decl))
873 return;
874
875 /* ??? Another way to do this would be to maintain a hashed
876 table of such critters. Instead of adding stuff to a DECL
877 to give certain attributes to it, we could use an external
878 hash map from DECL to set of attributes. */
879
880 /* Let the target reassign the RTL if it wants.
881 This is necessary, for example, when one machine specific
882 decl attribute overrides another. */
883 targetm.encode_section_info (decl, DECL_RTL (decl), false);
884
885 /* Make this function static known to the mudflap runtime. */
886 if (flag_mudflap && TREE_CODE (decl) == VAR_DECL)
887 mudflap_enqueue_decl (decl);
888
889 return;
890 }
891
892 name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
893
894 reg_number = decode_reg_name (name);
895
896 if (TREE_CODE (decl) != FUNCTION_DECL && DECL_REGISTER (decl))
897 {
898 /* First detect errors in declaring global registers. */
899 if (reg_number == -1)
900 error ("%Jregister name not specified for '%D'", decl, decl);
901 else if (reg_number < 0)
902 error ("%Jinvalid register name for '%D'", decl, decl);
903 else if (TYPE_MODE (TREE_TYPE (decl)) == BLKmode)
904 error ("%Jdata type of '%D' isn't suitable for a register",
905 decl, decl);
906 else if (! HARD_REGNO_MODE_OK (reg_number, TYPE_MODE (TREE_TYPE (decl))))
907 error ("%Jregister specified for '%D' isn't suitable for data type",
908 decl, decl);
909 /* Now handle properly declared static register variables. */
910 else
911 {
912 int nregs;
913
914 if (DECL_INITIAL (decl) != 0 && TREE_STATIC (decl))
915 {
916 DECL_INITIAL (decl) = 0;
917 error ("global register variable has initial value");
918 }
919 if (TREE_THIS_VOLATILE (decl))
920 warning ("volatile register variables don't work as you might wish");
921
922 /* If the user specified one of the eliminables registers here,
923 e.g., FRAME_POINTER_REGNUM, we don't want to get this variable
924 confused with that register and be eliminated. This usage is
925 somewhat suspect... */
926
927 SET_DECL_RTL (decl, gen_rtx_raw_REG (DECL_MODE (decl), reg_number));
928 ORIGINAL_REGNO (DECL_RTL (decl)) = reg_number;
929 REG_USERVAR_P (DECL_RTL (decl)) = 1;
930
931 if (TREE_STATIC (decl))
932 {
933 /* Make this register global, so not usable for anything
934 else. */
935 #ifdef ASM_DECLARE_REGISTER_GLOBAL
936 ASM_DECLARE_REGISTER_GLOBAL (asm_out_file, decl, reg_number, name);
937 #endif
938 nregs = hard_regno_nregs[reg_number][DECL_MODE (decl)];
939 while (nregs > 0)
940 globalize_reg (reg_number + --nregs);
941 }
942
943 /* As a register variable, it has no section. */
944 return;
945 }
946 }
947
948 /* Now handle ordinary static variables and functions (in memory).
949 Also handle vars declared register invalidly. */
950
951 if (name[0] == '*' && (reg_number >= 0 || reg_number == -3))
952 error ("%Jregister name given for non-register variable '%D'", decl, decl);
953
954 /* Specifying a section attribute on a variable forces it into a
955 non-.bss section, and thus it cannot be common. */
956 if (TREE_CODE (decl) == VAR_DECL
957 && DECL_SECTION_NAME (decl) != NULL_TREE
958 && DECL_INITIAL (decl) == NULL_TREE
959 && DECL_COMMON (decl))
960 DECL_COMMON (decl) = 0;
961
962 /* Variables can't be both common and weak. */
963 if (TREE_CODE (decl) == VAR_DECL && DECL_WEAK (decl))
964 DECL_COMMON (decl) = 0;
965
966 x = gen_rtx_SYMBOL_REF (Pmode, name);
967 SYMBOL_REF_WEAK (x) = DECL_WEAK (decl);
968 SYMBOL_REF_DECL (x) = decl;
969
970 x = gen_rtx_MEM (DECL_MODE (decl), x);
971 if (TREE_CODE (decl) != FUNCTION_DECL)
972 set_mem_attributes (x, decl, 1);
973 SET_DECL_RTL (decl, x);
974
975 /* Optionally set flags or add text to the name to record information
976 such as that it is a function name.
977 If the name is changed, the macro ASM_OUTPUT_LABELREF
978 will have to know how to strip this information. */
979 targetm.encode_section_info (decl, DECL_RTL (decl), true);
980
981 /* Make this function static known to the mudflap runtime. */
982 if (flag_mudflap && TREE_CODE (decl) == VAR_DECL)
983 mudflap_enqueue_decl (decl);
984 }
985
986 /* Make the rtl for variable VAR be volatile.
987 Use this only for static variables. */
988
989 void
990 make_var_volatile (tree var)
991 {
992 if (!MEM_P (DECL_RTL (var)))
993 abort ();
994
995 MEM_VOLATILE_P (DECL_RTL (var)) = 1;
996 }
997 \f
998 /* Output a string of literal assembler code
999 for an `asm' keyword used between functions. */
1000
1001 void
1002 assemble_asm (tree string)
1003 {
1004 app_enable ();
1005
1006 if (TREE_CODE (string) == ADDR_EXPR)
1007 string = TREE_OPERAND (string, 0);
1008
1009 fprintf (asm_out_file, "\t%s\n", TREE_STRING_POINTER (string));
1010 }
1011
1012 /* Record an element in the table of global destructors. SYMBOL is
1013 a SYMBOL_REF of the function to be called; PRIORITY is a number
1014 between 0 and MAX_INIT_PRIORITY. */
1015
1016 void
1017 default_stabs_asm_out_destructor (rtx symbol, int priority ATTRIBUTE_UNUSED)
1018 {
1019 /* Tell GNU LD that this is part of the static destructor set.
1020 This will work for any system that uses stabs, most usefully
1021 aout systems. */
1022 fprintf (asm_out_file, "%s\"___DTOR_LIST__\",22,0,0,", ASM_STABS_OP);
1023 assemble_name (asm_out_file, XSTR (symbol, 0));
1024 fputc ('\n', asm_out_file);
1025 }
1026
1027 void
1028 default_named_section_asm_out_destructor (rtx symbol, int priority)
1029 {
1030 const char *section = ".dtors";
1031 char buf[16];
1032
1033 /* ??? This only works reliably with the GNU linker. */
1034 if (priority != DEFAULT_INIT_PRIORITY)
1035 {
1036 sprintf (buf, ".dtors.%.5u",
1037 /* Invert the numbering so the linker puts us in the proper
1038 order; constructors are run from right to left, and the
1039 linker sorts in increasing order. */
1040 MAX_INIT_PRIORITY - priority);
1041 section = buf;
1042 }
1043
1044 named_section_flags (section, SECTION_WRITE);
1045 assemble_align (POINTER_SIZE);
1046 assemble_integer (symbol, POINTER_SIZE / BITS_PER_UNIT, POINTER_SIZE, 1);
1047 }
1048
1049 #ifdef DTORS_SECTION_ASM_OP
1050 void
1051 dtors_section (void)
1052 {
1053 if (in_section != in_dtors)
1054 {
1055 in_section = in_dtors;
1056 fputs (DTORS_SECTION_ASM_OP, asm_out_file);
1057 fputc ('\n', asm_out_file);
1058 }
1059 }
1060
1061 void
1062 default_dtor_section_asm_out_destructor (rtx symbol,
1063 int priority ATTRIBUTE_UNUSED)
1064 {
1065 dtors_section ();
1066 assemble_align (POINTER_SIZE);
1067 assemble_integer (symbol, POINTER_SIZE / BITS_PER_UNIT, POINTER_SIZE, 1);
1068 }
1069 #endif
1070
1071 /* Likewise for global constructors. */
1072
1073 void
1074 default_stabs_asm_out_constructor (rtx symbol, int priority ATTRIBUTE_UNUSED)
1075 {
1076 /* Tell GNU LD that this is part of the static destructor set.
1077 This will work for any system that uses stabs, most usefully
1078 aout systems. */
1079 fprintf (asm_out_file, "%s\"___CTOR_LIST__\",22,0,0,", ASM_STABS_OP);
1080 assemble_name (asm_out_file, XSTR (symbol, 0));
1081 fputc ('\n', asm_out_file);
1082 }
1083
1084 void
1085 default_named_section_asm_out_constructor (rtx symbol, int priority)
1086 {
1087 const char *section = ".ctors";
1088 char buf[16];
1089
1090 /* ??? This only works reliably with the GNU linker. */
1091 if (priority != DEFAULT_INIT_PRIORITY)
1092 {
1093 sprintf (buf, ".ctors.%.5u",
1094 /* Invert the numbering so the linker puts us in the proper
1095 order; constructors are run from right to left, and the
1096 linker sorts in increasing order. */
1097 MAX_INIT_PRIORITY - priority);
1098 section = buf;
1099 }
1100
1101 named_section_flags (section, SECTION_WRITE);
1102 assemble_align (POINTER_SIZE);
1103 assemble_integer (symbol, POINTER_SIZE / BITS_PER_UNIT, POINTER_SIZE, 1);
1104 }
1105
1106 #ifdef CTORS_SECTION_ASM_OP
1107 void
1108 ctors_section (void)
1109 {
1110 if (in_section != in_ctors)
1111 {
1112 in_section = in_ctors;
1113 fputs (CTORS_SECTION_ASM_OP, asm_out_file);
1114 fputc ('\n', asm_out_file);
1115 }
1116 }
1117
1118 void
1119 default_ctor_section_asm_out_constructor (rtx symbol,
1120 int priority ATTRIBUTE_UNUSED)
1121 {
1122 ctors_section ();
1123 assemble_align (POINTER_SIZE);
1124 assemble_integer (symbol, POINTER_SIZE / BITS_PER_UNIT, POINTER_SIZE, 1);
1125 }
1126 #endif
1127 \f
1128 /* CONSTANT_POOL_BEFORE_FUNCTION may be defined as an expression with
1129 a nonzero value if the constant pool should be output before the
1130 start of the function, or a zero value if the pool should output
1131 after the end of the function. The default is to put it before the
1132 start. */
1133
1134 #ifndef CONSTANT_POOL_BEFORE_FUNCTION
1135 #define CONSTANT_POOL_BEFORE_FUNCTION 1
1136 #endif
1137
1138 /* DECL is an object (either VAR_DECL or FUNCTION_DECL) which is going
1139 to be output to assembler.
1140 Set first_global_object_name and weak_global_object_name as appropriate. */
1141
1142 void
1143 notice_global_symbol (tree decl)
1144 {
1145 const char **type = &first_global_object_name;
1146
1147 if (first_global_object_name
1148 || !TREE_PUBLIC (decl) || DECL_EXTERNAL (decl)
1149 || !DECL_NAME (decl)
1150 || (TREE_CODE (decl) != FUNCTION_DECL
1151 && (TREE_CODE (decl) != VAR_DECL
1152 || (DECL_COMMON (decl)
1153 && (DECL_INITIAL (decl) == 0
1154 || DECL_INITIAL (decl) == error_mark_node))))
1155 || !MEM_P (DECL_RTL (decl)))
1156 return;
1157
1158 /* We win when global object is found, but it is useful to know about weak
1159 symbol as well so we can produce nicer unique names. */
1160 if (DECL_WEAK (decl) || DECL_ONE_ONLY (decl))
1161 type = &weak_global_object_name;
1162
1163 if (!*type)
1164 {
1165 const char *p;
1166 char *name;
1167 rtx decl_rtl = DECL_RTL (decl);
1168
1169 p = targetm.strip_name_encoding (XSTR (XEXP (decl_rtl, 0), 0));
1170 name = xstrdup (p);
1171
1172 *type = name;
1173 }
1174 }
1175
1176 /* Output assembler code for the constant pool of a function and associated
1177 with defining the name of the function. DECL describes the function.
1178 NAME is the function's name. For the constant pool, we use the current
1179 constant pool data. */
1180
1181 void
1182 assemble_start_function (tree decl, const char *fnname)
1183 {
1184 int align;
1185
1186 if (unlikely_text_section_name)
1187 free (unlikely_text_section_name);
1188
1189 unlikely_section_label_printed = false;
1190 unlikely_text_section_name = NULL;
1191
1192 unlikely_section_label = reconcat (unlikely_section_label,
1193 fnname, ".unlikely_section", NULL);
1194
1195 /* The following code does not need preprocessing in the assembler. */
1196
1197 app_disable ();
1198
1199 if (CONSTANT_POOL_BEFORE_FUNCTION)
1200 output_constant_pool (fnname, decl);
1201
1202 /* Make sure the cold text (code) section is properly aligned. This
1203 is necessary here in the case where the function has both hot and
1204 cold sections, because we don't want to re-set the alignment when the
1205 section switch happens mid-function. We don't need to set the hot
1206 section alignment here, because code further down in this function
1207 sets the alignment for whichever section comes first, and if there
1208 is a hot section it is guaranteed to be first. */
1209
1210 if (flag_reorder_blocks_and_partition)
1211 {
1212 unlikely_text_section ();
1213 assemble_align (FUNCTION_BOUNDARY);
1214 }
1215
1216 resolve_unique_section (decl, 0, flag_function_sections);
1217 function_section (decl);
1218
1219 /* Tell assembler to move to target machine's alignment for functions. */
1220 align = floor_log2 (FUNCTION_BOUNDARY / BITS_PER_UNIT);
1221 if (align < force_align_functions_log)
1222 align = force_align_functions_log;
1223 if (align > 0)
1224 {
1225 ASM_OUTPUT_ALIGN (asm_out_file, align);
1226 }
1227
1228 /* Handle a user-specified function alignment.
1229 Note that we still need to align to FUNCTION_BOUNDARY, as above,
1230 because ASM_OUTPUT_MAX_SKIP_ALIGN might not do any alignment at all. */
1231 if (align_functions_log > align
1232 && cfun->function_frequency != FUNCTION_FREQUENCY_UNLIKELY_EXECUTED)
1233 {
1234 #ifdef ASM_OUTPUT_MAX_SKIP_ALIGN
1235 ASM_OUTPUT_MAX_SKIP_ALIGN (asm_out_file,
1236 align_functions_log, align_functions - 1);
1237 #else
1238 ASM_OUTPUT_ALIGN (asm_out_file, align_functions_log);
1239 #endif
1240 }
1241
1242 #ifdef ASM_OUTPUT_FUNCTION_PREFIX
1243 ASM_OUTPUT_FUNCTION_PREFIX (asm_out_file, fnname);
1244 #endif
1245
1246 (*debug_hooks->begin_function) (decl);
1247
1248 /* Make function name accessible from other files, if appropriate. */
1249
1250 if (TREE_PUBLIC (decl))
1251 {
1252 notice_global_symbol (decl);
1253
1254 globalize_decl (decl);
1255
1256 maybe_assemble_visibility (decl);
1257 }
1258
1259 if (DECL_PRESERVE_P (decl))
1260 targetm.asm_out.mark_decl_preserved (fnname);
1261
1262 /* Do any machine/system dependent processing of the function name. */
1263 #ifdef ASM_DECLARE_FUNCTION_NAME
1264 ASM_DECLARE_FUNCTION_NAME (asm_out_file, fnname, current_function_decl);
1265 #else
1266 /* Standard thing is just output label for the function. */
1267 ASM_OUTPUT_LABEL (asm_out_file, fnname);
1268 #endif /* ASM_DECLARE_FUNCTION_NAME */
1269
1270 if (in_unlikely_text_section ()
1271 && !unlikely_section_label_printed)
1272 {
1273 ASM_OUTPUT_LABEL (asm_out_file, unlikely_section_label);
1274 unlikely_section_label_printed = true;
1275 }
1276 }
1277
1278 /* Output assembler code associated with defining the size of the
1279 function. DECL describes the function. NAME is the function's name. */
1280
1281 void
1282 assemble_end_function (tree decl, const char *fnname)
1283 {
1284 #ifdef ASM_DECLARE_FUNCTION_SIZE
1285 ASM_DECLARE_FUNCTION_SIZE (asm_out_file, fnname, decl);
1286 #endif
1287 if (! CONSTANT_POOL_BEFORE_FUNCTION)
1288 {
1289 output_constant_pool (fnname, decl);
1290 function_section (decl); /* need to switch back */
1291 }
1292 }
1293 \f
1294 /* Assemble code to leave SIZE bytes of zeros. */
1295
1296 void
1297 assemble_zeros (unsigned HOST_WIDE_INT size)
1298 {
1299 /* Do no output if -fsyntax-only. */
1300 if (flag_syntax_only)
1301 return;
1302
1303 #ifdef ASM_NO_SKIP_IN_TEXT
1304 /* The `space' pseudo in the text section outputs nop insns rather than 0s,
1305 so we must output 0s explicitly in the text section. */
1306 if ((ASM_NO_SKIP_IN_TEXT && in_text_section ())
1307 || (ASM_NO_SKIP_IN_TEXT && in_unlikely_text_section ()))
1308 {
1309 unsigned HOST_WIDE_INT i;
1310 for (i = 0; i < size; i++)
1311 assemble_integer (const0_rtx, 1, BITS_PER_UNIT, 1);
1312 }
1313 else
1314 #endif
1315 if (size > 0)
1316 ASM_OUTPUT_SKIP (asm_out_file, size);
1317 }
1318
1319 /* Assemble an alignment pseudo op for an ALIGN-bit boundary. */
1320
1321 void
1322 assemble_align (int align)
1323 {
1324 if (align > BITS_PER_UNIT)
1325 {
1326 ASM_OUTPUT_ALIGN (asm_out_file, floor_log2 (align / BITS_PER_UNIT));
1327 }
1328 }
1329
1330 /* Assemble a string constant with the specified C string as contents. */
1331
1332 void
1333 assemble_string (const char *p, int size)
1334 {
1335 int pos = 0;
1336 int maximum = 2000;
1337
1338 /* If the string is very long, split it up. */
1339
1340 while (pos < size)
1341 {
1342 int thissize = size - pos;
1343 if (thissize > maximum)
1344 thissize = maximum;
1345
1346 ASM_OUTPUT_ASCII (asm_out_file, p, thissize);
1347
1348 pos += thissize;
1349 p += thissize;
1350 }
1351 }
1352
1353 \f
1354 #if defined ASM_OUTPUT_ALIGNED_DECL_LOCAL
1355 #define ASM_EMIT_LOCAL(decl, name, size, rounded) \
1356 ASM_OUTPUT_ALIGNED_DECL_LOCAL (asm_out_file, decl, name, size, DECL_ALIGN (decl))
1357 #else
1358 #if defined ASM_OUTPUT_ALIGNED_LOCAL
1359 #define ASM_EMIT_LOCAL(decl, name, size, rounded) \
1360 ASM_OUTPUT_ALIGNED_LOCAL (asm_out_file, name, size, DECL_ALIGN (decl))
1361 #else
1362 #define ASM_EMIT_LOCAL(decl, name, size, rounded) \
1363 ASM_OUTPUT_LOCAL (asm_out_file, name, size, rounded)
1364 #endif
1365 #endif
1366
1367 #if defined ASM_OUTPUT_ALIGNED_BSS
1368 #define ASM_EMIT_BSS(decl, name, size, rounded) \
1369 ASM_OUTPUT_ALIGNED_BSS (asm_out_file, decl, name, size, DECL_ALIGN (decl))
1370 #else
1371 #if defined ASM_OUTPUT_BSS
1372 #define ASM_EMIT_BSS(decl, name, size, rounded) \
1373 ASM_OUTPUT_BSS (asm_out_file, decl, name, size, rounded)
1374 #else
1375 #undef ASM_EMIT_BSS
1376 #endif
1377 #endif
1378
1379 #if defined ASM_OUTPUT_ALIGNED_DECL_COMMON
1380 #define ASM_EMIT_COMMON(decl, name, size, rounded) \
1381 ASM_OUTPUT_ALIGNED_DECL_COMMON (asm_out_file, decl, name, size, DECL_ALIGN (decl))
1382 #else
1383 #if defined ASM_OUTPUT_ALIGNED_COMMON
1384 #define ASM_EMIT_COMMON(decl, name, size, rounded) \
1385 ASM_OUTPUT_ALIGNED_COMMON (asm_out_file, name, size, DECL_ALIGN (decl))
1386 #else
1387 #define ASM_EMIT_COMMON(decl, name, size, rounded) \
1388 ASM_OUTPUT_COMMON (asm_out_file, name, size, rounded)
1389 #endif
1390 #endif
1391
1392 static bool
1393 asm_emit_uninitialised (tree decl, const char *name,
1394 unsigned HOST_WIDE_INT size ATTRIBUTE_UNUSED,
1395 unsigned HOST_WIDE_INT rounded ATTRIBUTE_UNUSED)
1396 {
1397 enum
1398 {
1399 asm_dest_common,
1400 asm_dest_bss,
1401 asm_dest_local
1402 }
1403 destination = asm_dest_local;
1404
1405 /* ??? We should handle .bss via select_section mechanisms rather than
1406 via special target hooks. That would eliminate this special case. */
1407 if (TREE_PUBLIC (decl))
1408 {
1409 if (!DECL_COMMON (decl))
1410 #ifdef ASM_EMIT_BSS
1411 destination = asm_dest_bss;
1412 #else
1413 return false;
1414 #endif
1415 else
1416 destination = asm_dest_common;
1417 }
1418
1419 if (destination == asm_dest_bss)
1420 globalize_decl (decl);
1421 resolve_unique_section (decl, 0, flag_data_sections);
1422
1423 if (flag_shared_data)
1424 {
1425 switch (destination)
1426 {
1427 #ifdef ASM_OUTPUT_SHARED_BSS
1428 case asm_dest_bss:
1429 ASM_OUTPUT_SHARED_BSS (asm_out_file, decl, name, size, rounded);
1430 return;
1431 #endif
1432 #ifdef ASM_OUTPUT_SHARED_COMMON
1433 case asm_dest_common:
1434 ASM_OUTPUT_SHARED_COMMON (asm_out_file, name, size, rounded);
1435 return;
1436 #endif
1437 #ifdef ASM_OUTPUT_SHARED_LOCAL
1438 case asm_dest_local:
1439 ASM_OUTPUT_SHARED_LOCAL (asm_out_file, name, size, rounded);
1440 return;
1441 #endif
1442 default:
1443 break;
1444 }
1445 }
1446
1447 switch (destination)
1448 {
1449 #ifdef ASM_EMIT_BSS
1450 case asm_dest_bss:
1451 ASM_EMIT_BSS (decl, name, size, rounded);
1452 break;
1453 #endif
1454 case asm_dest_common:
1455 ASM_EMIT_COMMON (decl, name, size, rounded);
1456 break;
1457 case asm_dest_local:
1458 ASM_EMIT_LOCAL (decl, name, size, rounded);
1459 break;
1460 default:
1461 abort ();
1462 }
1463
1464 return true;
1465 }
1466
1467 /* Assemble everything that is needed for a variable or function declaration.
1468 Not used for automatic variables, and not used for function definitions.
1469 Should not be called for variables of incomplete structure type.
1470
1471 TOP_LEVEL is nonzero if this variable has file scope.
1472 AT_END is nonzero if this is the special handling, at end of compilation,
1473 to define things that have had only tentative definitions.
1474 DONT_OUTPUT_DATA if nonzero means don't actually output the
1475 initial value (that will be done by the caller). */
1476
1477 void
1478 assemble_variable (tree decl, int top_level ATTRIBUTE_UNUSED,
1479 int at_end ATTRIBUTE_UNUSED, int dont_output_data)
1480 {
1481 const char *name;
1482 unsigned int align;
1483 int reloc = 0;
1484 rtx decl_rtl;
1485
1486 if (lang_hooks.decls.prepare_assemble_variable)
1487 lang_hooks.decls.prepare_assemble_variable (decl);
1488
1489 last_assemble_variable_decl = 0;
1490
1491 /* Normally no need to say anything here for external references,
1492 since assemble_external is called by the language-specific code
1493 when a declaration is first seen. */
1494
1495 if (DECL_EXTERNAL (decl))
1496 return;
1497
1498 /* Output no assembler code for a function declaration.
1499 Only definitions of functions output anything. */
1500
1501 if (TREE_CODE (decl) == FUNCTION_DECL)
1502 return;
1503
1504 /* Do nothing for global register variables. */
1505 if (DECL_RTL_SET_P (decl) && REG_P (DECL_RTL (decl)))
1506 {
1507 TREE_ASM_WRITTEN (decl) = 1;
1508 return;
1509 }
1510
1511 /* If type was incomplete when the variable was declared,
1512 see if it is complete now. */
1513
1514 if (DECL_SIZE (decl) == 0)
1515 layout_decl (decl, 0);
1516
1517 /* Still incomplete => don't allocate it; treat the tentative defn
1518 (which is what it must have been) as an `extern' reference. */
1519
1520 if (!dont_output_data && DECL_SIZE (decl) == 0)
1521 {
1522 error ("%Jstorage size of `%D' isn't known", decl, decl);
1523 TREE_ASM_WRITTEN (decl) = 1;
1524 return;
1525 }
1526
1527 /* The first declaration of a variable that comes through this function
1528 decides whether it is global (in C, has external linkage)
1529 or local (in C, has internal linkage). So do nothing more
1530 if this function has already run. */
1531
1532 if (TREE_ASM_WRITTEN (decl))
1533 return;
1534
1535 /* Make sure targetm.encode_section_info is invoked before we set
1536 ASM_WRITTEN. */
1537 decl_rtl = DECL_RTL (decl);
1538
1539 TREE_ASM_WRITTEN (decl) = 1;
1540
1541 /* Do no output if -fsyntax-only. */
1542 if (flag_syntax_only)
1543 return;
1544
1545 app_disable ();
1546
1547 if (! dont_output_data
1548 && ! host_integerp (DECL_SIZE_UNIT (decl), 1))
1549 {
1550 error ("%Jsize of variable '%D' is too large", decl, decl);
1551 return;
1552 }
1553
1554 name = XSTR (XEXP (decl_rtl, 0), 0);
1555 if (TREE_PUBLIC (decl) && DECL_NAME (decl))
1556 notice_global_symbol (decl);
1557
1558 /* Compute the alignment of this data. */
1559
1560 align = DECL_ALIGN (decl);
1561
1562 /* In the case for initialing an array whose length isn't specified,
1563 where we have not yet been able to do the layout,
1564 figure out the proper alignment now. */
1565 if (dont_output_data && DECL_SIZE (decl) == 0
1566 && TREE_CODE (TREE_TYPE (decl)) == ARRAY_TYPE)
1567 align = MAX (align, TYPE_ALIGN (TREE_TYPE (TREE_TYPE (decl))));
1568
1569 /* Some object file formats have a maximum alignment which they support.
1570 In particular, a.out format supports a maximum alignment of 4. */
1571 if (align > MAX_OFILE_ALIGNMENT)
1572 {
1573 warning ("%Jalignment of '%D' is greater than maximum object "
1574 "file alignment. Using %d", decl, decl,
1575 MAX_OFILE_ALIGNMENT/BITS_PER_UNIT);
1576 align = MAX_OFILE_ALIGNMENT;
1577 }
1578
1579 /* On some machines, it is good to increase alignment sometimes. */
1580 if (! DECL_USER_ALIGN (decl))
1581 {
1582 #ifdef DATA_ALIGNMENT
1583 align = DATA_ALIGNMENT (TREE_TYPE (decl), align);
1584 #endif
1585 #ifdef CONSTANT_ALIGNMENT
1586 if (DECL_INITIAL (decl) != 0 && DECL_INITIAL (decl) != error_mark_node)
1587 align = CONSTANT_ALIGNMENT (DECL_INITIAL (decl), align);
1588 #endif
1589 }
1590
1591 /* Reset the alignment in case we have made it tighter, so we can benefit
1592 from it in get_pointer_alignment. */
1593 DECL_ALIGN (decl) = align;
1594 set_mem_align (decl_rtl, align);
1595
1596 if (TREE_PUBLIC (decl))
1597 maybe_assemble_visibility (decl);
1598
1599 if (DECL_PRESERVE_P (decl))
1600 targetm.asm_out.mark_decl_preserved (name);
1601
1602 /* Output any data that we will need to use the address of. */
1603 if (DECL_INITIAL (decl) == error_mark_node)
1604 reloc = contains_pointers_p (TREE_TYPE (decl)) ? 3 : 0;
1605 else if (DECL_INITIAL (decl))
1606 {
1607 reloc = compute_reloc_for_constant (DECL_INITIAL (decl));
1608 output_addressed_constants (DECL_INITIAL (decl));
1609 }
1610 resolve_unique_section (decl, reloc, flag_data_sections);
1611
1612 /* Handle uninitialized definitions. */
1613
1614 /* If the decl has been given an explicit section name, then it
1615 isn't common, and shouldn't be handled as such. */
1616 if (DECL_SECTION_NAME (decl) || dont_output_data)
1617 ;
1618 /* We don't implement common thread-local data at present. */
1619 else if (DECL_THREAD_LOCAL (decl))
1620 {
1621 if (DECL_COMMON (decl))
1622 sorry ("thread-local COMMON data not implemented");
1623 }
1624 else if (DECL_INITIAL (decl) == 0
1625 || DECL_INITIAL (decl) == error_mark_node
1626 || (flag_zero_initialized_in_bss
1627 /* Leave constant zeroes in .rodata so they can be shared. */
1628 && !TREE_READONLY (decl)
1629 && initializer_zerop (DECL_INITIAL (decl))))
1630 {
1631 unsigned HOST_WIDE_INT size = tree_low_cst (DECL_SIZE_UNIT (decl), 1);
1632 unsigned HOST_WIDE_INT rounded = size;
1633
1634 /* Don't allocate zero bytes of common,
1635 since that means "undefined external" in the linker. */
1636 if (size == 0)
1637 rounded = 1;
1638
1639 /* Round size up to multiple of BIGGEST_ALIGNMENT bits
1640 so that each uninitialized object starts on such a boundary. */
1641 rounded += (BIGGEST_ALIGNMENT / BITS_PER_UNIT) - 1;
1642 rounded = (rounded / (BIGGEST_ALIGNMENT / BITS_PER_UNIT)
1643 * (BIGGEST_ALIGNMENT / BITS_PER_UNIT));
1644
1645 #if !defined(ASM_OUTPUT_ALIGNED_COMMON) && !defined(ASM_OUTPUT_ALIGNED_DECL_COMMON) && !defined(ASM_OUTPUT_ALIGNED_BSS)
1646 if ((unsigned HOST_WIDE_INT) DECL_ALIGN_UNIT (decl) > rounded)
1647 warning ("%Jrequested alignment for '%D' is greater than "
1648 "implemented alignment of %d", decl, decl, rounded);
1649 #endif
1650
1651 /* If the target cannot output uninitialized but not common global data
1652 in .bss, then we have to use .data, so fall through. */
1653 if (asm_emit_uninitialised (decl, name, size, rounded))
1654 return;
1655 }
1656
1657 /* Handle initialized definitions.
1658 Also handle uninitialized global definitions if -fno-common and the
1659 target doesn't support ASM_OUTPUT_BSS. */
1660
1661 /* First make the assembler name(s) global if appropriate. */
1662 if (TREE_PUBLIC (decl) && DECL_NAME (decl))
1663 globalize_decl (decl);
1664
1665 /* Switch to the appropriate section. */
1666 variable_section (decl, reloc);
1667
1668 /* dbxout.c needs to know this. */
1669 if (in_text_section () || in_unlikely_text_section ())
1670 DECL_IN_TEXT_SECTION (decl) = 1;
1671
1672 /* Output the alignment of this data. */
1673 if (align > BITS_PER_UNIT)
1674 ASM_OUTPUT_ALIGN (asm_out_file, floor_log2 (DECL_ALIGN_UNIT (decl)));
1675
1676 /* Do any machine/system dependent processing of the object. */
1677 #ifdef ASM_DECLARE_OBJECT_NAME
1678 last_assemble_variable_decl = decl;
1679 ASM_DECLARE_OBJECT_NAME (asm_out_file, name, decl);
1680 #else
1681 /* Standard thing is just output label for the object. */
1682 ASM_OUTPUT_LABEL (asm_out_file, name);
1683 #endif /* ASM_DECLARE_OBJECT_NAME */
1684
1685 if (!dont_output_data)
1686 {
1687 if (DECL_INITIAL (decl)
1688 && DECL_INITIAL (decl) != error_mark_node
1689 && !initializer_zerop (DECL_INITIAL (decl)))
1690 /* Output the actual data. */
1691 output_constant (DECL_INITIAL (decl),
1692 tree_low_cst (DECL_SIZE_UNIT (decl), 1),
1693 align);
1694 else
1695 /* Leave space for it. */
1696 assemble_zeros (tree_low_cst (DECL_SIZE_UNIT (decl), 1));
1697 }
1698 }
1699
1700 /* Return 1 if type TYPE contains any pointers. */
1701
1702 static int
1703 contains_pointers_p (tree type)
1704 {
1705 switch (TREE_CODE (type))
1706 {
1707 case POINTER_TYPE:
1708 case REFERENCE_TYPE:
1709 /* I'm not sure whether OFFSET_TYPE needs this treatment,
1710 so I'll play safe and return 1. */
1711 case OFFSET_TYPE:
1712 return 1;
1713
1714 case RECORD_TYPE:
1715 case UNION_TYPE:
1716 case QUAL_UNION_TYPE:
1717 {
1718 tree fields;
1719 /* For a type that has fields, see if the fields have pointers. */
1720 for (fields = TYPE_FIELDS (type); fields; fields = TREE_CHAIN (fields))
1721 if (TREE_CODE (fields) == FIELD_DECL
1722 && contains_pointers_p (TREE_TYPE (fields)))
1723 return 1;
1724 return 0;
1725 }
1726
1727 case ARRAY_TYPE:
1728 /* An array type contains pointers if its element type does. */
1729 return contains_pointers_p (TREE_TYPE (type));
1730
1731 default:
1732 return 0;
1733 }
1734 }
1735
1736 #ifdef ASM_OUTPUT_EXTERNAL
1737 /* True if DECL is a function decl for which no out-of-line copy exists.
1738 It is assumed that DECL's assembler name has been set. */
1739
1740 static bool
1741 incorporeal_function_p (tree decl)
1742 {
1743 if (TREE_CODE (decl) == FUNCTION_DECL && DECL_BUILT_IN (decl))
1744 {
1745 const char *name;
1746
1747 if (DECL_BUILT_IN_CLASS (decl) == BUILT_IN_NORMAL
1748 && DECL_FUNCTION_CODE (decl) == BUILT_IN_ALLOCA)
1749 return true;
1750
1751 name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
1752 if (strncmp (name, "__builtin_", strlen ("__builtin_")) == 0)
1753 return true;
1754 }
1755 return false;
1756 }
1757 #endif
1758
1759 /* Output something to declare an external symbol to the assembler.
1760 (Most assemblers don't need this, so we normally output nothing.)
1761 Do nothing if DECL is not external. */
1762
1763 void
1764 assemble_external (tree decl ATTRIBUTE_UNUSED)
1765 {
1766 /* Because most platforms do not define ASM_OUTPUT_EXTERNAL, the
1767 main body of this code is only rarely exercised. To provide some
1768 testing, on all platforms, we make sure that the ASM_OUT_FILE is
1769 open. If it's not, we should not be calling this function. */
1770 if (!asm_out_file)
1771 abort ();
1772
1773 #ifdef ASM_OUTPUT_EXTERNAL
1774 if (DECL_P (decl) && DECL_EXTERNAL (decl) && TREE_PUBLIC (decl))
1775 {
1776 rtx rtl = DECL_RTL (decl);
1777
1778 if (MEM_P (rtl) && GET_CODE (XEXP (rtl, 0)) == SYMBOL_REF
1779 && !SYMBOL_REF_USED (XEXP (rtl, 0))
1780 && !incorporeal_function_p (decl))
1781 {
1782 /* Some systems do require some output. */
1783 SYMBOL_REF_USED (XEXP (rtl, 0)) = 1;
1784 ASM_OUTPUT_EXTERNAL (asm_out_file, decl, XSTR (XEXP (rtl, 0), 0));
1785 }
1786 }
1787 #endif
1788 }
1789
1790 /* Similar, for calling a library function FUN. */
1791
1792 void
1793 assemble_external_libcall (rtx fun)
1794 {
1795 /* Declare library function name external when first used, if nec. */
1796 if (! SYMBOL_REF_USED (fun))
1797 {
1798 SYMBOL_REF_USED (fun) = 1;
1799 targetm.asm_out.external_libcall (fun);
1800 }
1801 }
1802
1803 /* Assemble a label named NAME. */
1804
1805 void
1806 assemble_label (const char *name)
1807 {
1808 ASM_OUTPUT_LABEL (asm_out_file, name);
1809 }
1810
1811 /* Set the symbol_referenced flag for ID. */
1812 void
1813 mark_referenced (tree id)
1814 {
1815 TREE_SYMBOL_REFERENCED (id) = 1;
1816 }
1817
1818 /* Set the symbol_referenced flag for DECL and notify callgraph. */
1819 void
1820 mark_decl_referenced (tree decl)
1821 {
1822 if (TREE_CODE (decl) == FUNCTION_DECL)
1823 cgraph_mark_needed_node (cgraph_node (decl));
1824 else if (TREE_CODE (decl) == VAR_DECL)
1825 cgraph_varpool_mark_needed_node (cgraph_varpool_node (decl));
1826 /* else do nothing - we can get various sorts of CST nodes here,
1827 which do not need to be marked. */
1828 }
1829
1830 /* Output to FILE a reference to the assembler name of a C-level name NAME.
1831 If NAME starts with a *, the rest of NAME is output verbatim.
1832 Otherwise NAME is transformed in an implementation-defined way
1833 (usually by the addition of an underscore).
1834 Many macros in the tm file are defined to call this function. */
1835
1836 void
1837 assemble_name (FILE *file, const char *name)
1838 {
1839 const char *real_name;
1840 tree id;
1841
1842 real_name = targetm.strip_name_encoding (name);
1843
1844 id = maybe_get_identifier (real_name);
1845 if (id)
1846 mark_referenced (id);
1847
1848 if (name[0] == '*')
1849 fputs (&name[1], file);
1850 else
1851 ASM_OUTPUT_LABELREF (file, name);
1852 }
1853
1854 /* Allocate SIZE bytes writable static space with a gensym name
1855 and return an RTX to refer to its address. */
1856
1857 rtx
1858 assemble_static_space (unsigned HOST_WIDE_INT size)
1859 {
1860 char name[12];
1861 const char *namestring;
1862 rtx x;
1863
1864 #if 0
1865 if (flag_shared_data)
1866 data_section ();
1867 #endif
1868
1869 ASM_GENERATE_INTERNAL_LABEL (name, "LF", const_labelno);
1870 ++const_labelno;
1871 namestring = ggc_strdup (name);
1872
1873 x = gen_rtx_SYMBOL_REF (Pmode, namestring);
1874 SYMBOL_REF_FLAGS (x) = SYMBOL_FLAG_LOCAL;
1875
1876 #ifdef ASM_OUTPUT_ALIGNED_DECL_LOCAL
1877 ASM_OUTPUT_ALIGNED_DECL_LOCAL (asm_out_file, NULL_TREE, name, size,
1878 BIGGEST_ALIGNMENT);
1879 #else
1880 #ifdef ASM_OUTPUT_ALIGNED_LOCAL
1881 ASM_OUTPUT_ALIGNED_LOCAL (asm_out_file, name, size, BIGGEST_ALIGNMENT);
1882 #else
1883 {
1884 /* Round size up to multiple of BIGGEST_ALIGNMENT bits
1885 so that each uninitialized object starts on such a boundary. */
1886 /* Variable `rounded' might or might not be used in ASM_OUTPUT_LOCAL. */
1887 unsigned HOST_WIDE_INT rounded ATTRIBUTE_UNUSED
1888 = ((size + (BIGGEST_ALIGNMENT / BITS_PER_UNIT) - 1)
1889 / (BIGGEST_ALIGNMENT / BITS_PER_UNIT)
1890 * (BIGGEST_ALIGNMENT / BITS_PER_UNIT));
1891 ASM_OUTPUT_LOCAL (asm_out_file, name, size, rounded);
1892 }
1893 #endif
1894 #endif
1895 return x;
1896 }
1897
1898 /* Assemble the static constant template for function entry trampolines.
1899 This is done at most once per compilation.
1900 Returns an RTX for the address of the template. */
1901
1902 static GTY(()) rtx initial_trampoline;
1903
1904 #ifdef TRAMPOLINE_TEMPLATE
1905 rtx
1906 assemble_trampoline_template (void)
1907 {
1908 char label[256];
1909 const char *name;
1910 int align;
1911 rtx symbol;
1912
1913 if (initial_trampoline)
1914 return initial_trampoline;
1915
1916 /* By default, put trampoline templates in read-only data section. */
1917
1918 #ifdef TRAMPOLINE_SECTION
1919 TRAMPOLINE_SECTION ();
1920 #else
1921 readonly_data_section ();
1922 #endif
1923
1924 /* Write the assembler code to define one. */
1925 align = floor_log2 (TRAMPOLINE_ALIGNMENT / BITS_PER_UNIT);
1926 if (align > 0)
1927 {
1928 ASM_OUTPUT_ALIGN (asm_out_file, align);
1929 }
1930
1931 targetm.asm_out.internal_label (asm_out_file, "LTRAMP", 0);
1932 TRAMPOLINE_TEMPLATE (asm_out_file);
1933
1934 /* Record the rtl to refer to it. */
1935 ASM_GENERATE_INTERNAL_LABEL (label, "LTRAMP", 0);
1936 name = ggc_strdup (label);
1937 symbol = gen_rtx_SYMBOL_REF (Pmode, name);
1938 SYMBOL_REF_FLAGS (symbol) = SYMBOL_FLAG_LOCAL;
1939
1940 initial_trampoline = gen_rtx_MEM (BLKmode, symbol);
1941 set_mem_align (initial_trampoline, TRAMPOLINE_ALIGNMENT);
1942
1943 return initial_trampoline;
1944 }
1945 #endif
1946 \f
1947 /* A and B are either alignments or offsets. Return the minimum alignment
1948 that may be assumed after adding the two together. */
1949
1950 static inline unsigned
1951 min_align (unsigned int a, unsigned int b)
1952 {
1953 return (a | b) & -(a | b);
1954 }
1955
1956 /* Return the assembler directive for creating a given kind of integer
1957 object. SIZE is the number of bytes in the object and ALIGNED_P
1958 indicates whether it is known to be aligned. Return NULL if the
1959 assembly dialect has no such directive.
1960
1961 The returned string should be printed at the start of a new line and
1962 be followed immediately by the object's initial value. */
1963
1964 const char *
1965 integer_asm_op (int size, int aligned_p)
1966 {
1967 struct asm_int_op *ops;
1968
1969 if (aligned_p)
1970 ops = &targetm.asm_out.aligned_op;
1971 else
1972 ops = &targetm.asm_out.unaligned_op;
1973
1974 switch (size)
1975 {
1976 case 1:
1977 return targetm.asm_out.byte_op;
1978 case 2:
1979 return ops->hi;
1980 case 4:
1981 return ops->si;
1982 case 8:
1983 return ops->di;
1984 case 16:
1985 return ops->ti;
1986 default:
1987 return NULL;
1988 }
1989 }
1990
1991 /* Use directive OP to assemble an integer object X. Print OP at the
1992 start of the line, followed immediately by the value of X. */
1993
1994 void
1995 assemble_integer_with_op (const char *op, rtx x)
1996 {
1997 fputs (op, asm_out_file);
1998 output_addr_const (asm_out_file, x);
1999 fputc ('\n', asm_out_file);
2000 }
2001
2002 /* The default implementation of the asm_out.integer target hook. */
2003
2004 bool
2005 default_assemble_integer (rtx x ATTRIBUTE_UNUSED,
2006 unsigned int size ATTRIBUTE_UNUSED,
2007 int aligned_p ATTRIBUTE_UNUSED)
2008 {
2009 const char *op = integer_asm_op (size, aligned_p);
2010 return op && (assemble_integer_with_op (op, x), true);
2011 }
2012
2013 /* Assemble the integer constant X into an object of SIZE bytes. ALIGN is
2014 the alignment of the integer in bits. Return 1 if we were able to output
2015 the constant, otherwise 0. If FORCE is nonzero, abort if we can't output
2016 the constant. */
2017
2018 bool
2019 assemble_integer (rtx x, unsigned int size, unsigned int align, int force)
2020 {
2021 int aligned_p;
2022
2023 aligned_p = (align >= MIN (size * BITS_PER_UNIT, BIGGEST_ALIGNMENT));
2024
2025 /* See if the target hook can handle this kind of object. */
2026 if (targetm.asm_out.integer (x, size, aligned_p))
2027 return true;
2028
2029 /* If the object is a multi-byte one, try splitting it up. Split
2030 it into words it if is multi-word, otherwise split it into bytes. */
2031 if (size > 1)
2032 {
2033 enum machine_mode omode, imode;
2034 unsigned int subalign;
2035 unsigned int subsize, i;
2036
2037 subsize = size > UNITS_PER_WORD? UNITS_PER_WORD : 1;
2038 subalign = MIN (align, subsize * BITS_PER_UNIT);
2039 omode = mode_for_size (subsize * BITS_PER_UNIT, MODE_INT, 0);
2040 imode = mode_for_size (size * BITS_PER_UNIT, MODE_INT, 0);
2041
2042 for (i = 0; i < size; i += subsize)
2043 {
2044 rtx partial = simplify_subreg (omode, x, imode, i);
2045 if (!partial || !assemble_integer (partial, subsize, subalign, 0))
2046 break;
2047 }
2048 if (i == size)
2049 return true;
2050
2051 /* If we've printed some of it, but not all of it, there's no going
2052 back now. */
2053 if (i > 0)
2054 abort ();
2055 }
2056
2057 if (force)
2058 abort ();
2059
2060 return false;
2061 }
2062 \f
2063 void
2064 assemble_real (REAL_VALUE_TYPE d, enum machine_mode mode, unsigned int align)
2065 {
2066 long data[4];
2067 int i;
2068 int bitsize, nelts, nunits, units_per;
2069
2070 /* This is hairy. We have a quantity of known size. real_to_target
2071 will put it into an array of *host* longs, 32 bits per element
2072 (even if long is more than 32 bits). We need to determine the
2073 number of array elements that are occupied (nelts) and the number
2074 of *target* min-addressable units that will be occupied in the
2075 object file (nunits). We cannot assume that 32 divides the
2076 mode's bitsize (size * BITS_PER_UNIT) evenly.
2077
2078 size * BITS_PER_UNIT is used here to make sure that padding bits
2079 (which might appear at either end of the value; real_to_target
2080 will include the padding bits in its output array) are included. */
2081
2082 nunits = GET_MODE_SIZE (mode);
2083 bitsize = nunits * BITS_PER_UNIT;
2084 nelts = CEIL (bitsize, 32);
2085 units_per = 32 / BITS_PER_UNIT;
2086
2087 real_to_target (data, &d, mode);
2088
2089 /* Put out the first word with the specified alignment. */
2090 assemble_integer (GEN_INT (data[0]), MIN (nunits, units_per), align, 1);
2091 nunits -= units_per;
2092
2093 /* Subsequent words need only 32-bit alignment. */
2094 align = min_align (align, 32);
2095
2096 for (i = 1; i < nelts; i++)
2097 {
2098 assemble_integer (GEN_INT (data[i]), MIN (nunits, units_per), align, 1);
2099 nunits -= units_per;
2100 }
2101 }
2102 \f
2103 /* Given an expression EXP with a constant value,
2104 reduce it to the sum of an assembler symbol and an integer.
2105 Store them both in the structure *VALUE.
2106 Abort if EXP does not reduce. */
2107
2108 struct addr_const GTY(())
2109 {
2110 rtx base;
2111 HOST_WIDE_INT offset;
2112 };
2113
2114 static void
2115 decode_addr_const (tree exp, struct addr_const *value)
2116 {
2117 tree target = TREE_OPERAND (exp, 0);
2118 int offset = 0;
2119 rtx x;
2120
2121 while (1)
2122 {
2123 if (TREE_CODE (target) == COMPONENT_REF
2124 && host_integerp (byte_position (TREE_OPERAND (target, 1)), 0))
2125
2126 {
2127 offset += int_byte_position (TREE_OPERAND (target, 1));
2128 target = TREE_OPERAND (target, 0);
2129 }
2130 else if (TREE_CODE (target) == ARRAY_REF
2131 || TREE_CODE (target) == ARRAY_RANGE_REF)
2132 {
2133 offset += (tree_low_cst (TYPE_SIZE_UNIT (TREE_TYPE (target)), 1)
2134 * tree_low_cst (TREE_OPERAND (target, 1), 0));
2135 target = TREE_OPERAND (target, 0);
2136 }
2137 else
2138 break;
2139 }
2140
2141 switch (TREE_CODE (target))
2142 {
2143 case VAR_DECL:
2144 case FUNCTION_DECL:
2145 x = DECL_RTL (target);
2146 break;
2147
2148 case LABEL_DECL:
2149 x = gen_rtx_MEM (FUNCTION_MODE,
2150 gen_rtx_LABEL_REF (VOIDmode, force_label_rtx (target)));
2151 break;
2152
2153 case REAL_CST:
2154 case STRING_CST:
2155 case COMPLEX_CST:
2156 case CONSTRUCTOR:
2157 case INTEGER_CST:
2158 x = output_constant_def (target, 1);
2159 break;
2160
2161 default:
2162 abort ();
2163 }
2164
2165 if (!MEM_P (x))
2166 abort ();
2167 x = XEXP (x, 0);
2168
2169 value->base = x;
2170 value->offset = offset;
2171 }
2172 \f
2173 /* Uniquize all constants that appear in memory.
2174 Each constant in memory thus far output is recorded
2175 in `const_desc_table'. */
2176
2177 struct constant_descriptor_tree GTY(())
2178 {
2179 /* A MEM for the constant. */
2180 rtx rtl;
2181
2182 /* The value of the constant. */
2183 tree value;
2184 };
2185
2186 static GTY((param_is (struct constant_descriptor_tree)))
2187 htab_t const_desc_htab;
2188
2189 static struct constant_descriptor_tree * build_constant_desc (tree);
2190 static void maybe_output_constant_def_contents (struct constant_descriptor_tree *, int);
2191
2192 /* Compute a hash code for a constant expression. */
2193
2194 static hashval_t
2195 const_desc_hash (const void *ptr)
2196 {
2197 return const_hash_1 (((struct constant_descriptor_tree *)ptr)->value);
2198 }
2199
2200 static hashval_t
2201 const_hash_1 (const tree exp)
2202 {
2203 const char *p;
2204 hashval_t hi;
2205 int len, i;
2206 enum tree_code code = TREE_CODE (exp);
2207
2208 /* Either set P and LEN to the address and len of something to hash and
2209 exit the switch or return a value. */
2210
2211 switch (code)
2212 {
2213 case INTEGER_CST:
2214 p = (char *) &TREE_INT_CST (exp);
2215 len = sizeof TREE_INT_CST (exp);
2216 break;
2217
2218 case REAL_CST:
2219 return real_hash (TREE_REAL_CST_PTR (exp));
2220
2221 case STRING_CST:
2222 p = TREE_STRING_POINTER (exp);
2223 len = TREE_STRING_LENGTH (exp);
2224 break;
2225
2226 case COMPLEX_CST:
2227 return (const_hash_1 (TREE_REALPART (exp)) * 5
2228 + const_hash_1 (TREE_IMAGPART (exp)));
2229
2230 case CONSTRUCTOR:
2231 if (TREE_CODE (TREE_TYPE (exp)) == SET_TYPE)
2232 {
2233 char *tmp;
2234
2235 len = int_size_in_bytes (TREE_TYPE (exp));
2236 tmp = alloca (len);
2237 get_set_constructor_bytes (exp, (unsigned char *) tmp, len);
2238 p = tmp;
2239 break;
2240 }
2241 else
2242 {
2243 tree link;
2244
2245 hi = 5 + int_size_in_bytes (TREE_TYPE (exp));
2246
2247 for (link = CONSTRUCTOR_ELTS (exp); link; link = TREE_CHAIN (link))
2248 if (TREE_VALUE (link))
2249 hi = hi * 603 + const_hash_1 (TREE_VALUE (link));
2250
2251 return hi;
2252 }
2253
2254 case ADDR_EXPR:
2255 case FDESC_EXPR:
2256 {
2257 struct addr_const value;
2258
2259 decode_addr_const (exp, &value);
2260 if (GET_CODE (value.base) == SYMBOL_REF)
2261 {
2262 /* Don't hash the address of the SYMBOL_REF;
2263 only use the offset and the symbol name. */
2264 hi = value.offset;
2265 p = XSTR (value.base, 0);
2266 for (i = 0; p[i] != 0; i++)
2267 hi = ((hi * 613) + (unsigned) (p[i]));
2268 }
2269 else if (GET_CODE (value.base) == LABEL_REF)
2270 hi = value.offset + CODE_LABEL_NUMBER (XEXP (value.base, 0)) * 13;
2271 else
2272 abort ();
2273 }
2274 return hi;
2275
2276 case PLUS_EXPR:
2277 case MINUS_EXPR:
2278 return (const_hash_1 (TREE_OPERAND (exp, 0)) * 9
2279 + const_hash_1 (TREE_OPERAND (exp, 1)));
2280
2281 case NOP_EXPR:
2282 case CONVERT_EXPR:
2283 case NON_LVALUE_EXPR:
2284 return const_hash_1 (TREE_OPERAND (exp, 0)) * 7 + 2;
2285
2286 default:
2287 /* A language specific constant. Just hash the code. */
2288 return code;
2289 }
2290
2291 /* Compute hashing function. */
2292 hi = len;
2293 for (i = 0; i < len; i++)
2294 hi = ((hi * 613) + (unsigned) (p[i]));
2295
2296 return hi;
2297 }
2298
2299 /* Wrapper of compare_constant, for the htab interface. */
2300 static int
2301 const_desc_eq (const void *p1, const void *p2)
2302 {
2303 return compare_constant (((struct constant_descriptor_tree *)p1)->value,
2304 ((struct constant_descriptor_tree *)p2)->value);
2305 }
2306
2307 /* Compare t1 and t2, and return 1 only if they are known to result in
2308 the same bit pattern on output. */
2309
2310 static int
2311 compare_constant (const tree t1, const tree t2)
2312 {
2313 enum tree_code typecode;
2314
2315 if (t1 == NULL_TREE)
2316 return t2 == NULL_TREE;
2317 if (t2 == NULL_TREE)
2318 return 0;
2319
2320 if (TREE_CODE (t1) != TREE_CODE (t2))
2321 return 0;
2322
2323 switch (TREE_CODE (t1))
2324 {
2325 case INTEGER_CST:
2326 /* Integer constants are the same only if the same width of type. */
2327 if (TYPE_PRECISION (TREE_TYPE (t1)) != TYPE_PRECISION (TREE_TYPE (t2)))
2328 return 0;
2329 return tree_int_cst_equal (t1, t2);
2330
2331 case REAL_CST:
2332 /* Real constants are the same only if the same width of type. */
2333 if (TYPE_PRECISION (TREE_TYPE (t1)) != TYPE_PRECISION (TREE_TYPE (t2)))
2334 return 0;
2335
2336 return REAL_VALUES_IDENTICAL (TREE_REAL_CST (t1), TREE_REAL_CST (t2));
2337
2338 case STRING_CST:
2339 if (TYPE_MODE (TREE_TYPE (t1)) != TYPE_MODE (TREE_TYPE (t2)))
2340 return 0;
2341
2342 return (TREE_STRING_LENGTH (t1) == TREE_STRING_LENGTH (t2)
2343 && ! memcmp (TREE_STRING_POINTER (t1), TREE_STRING_POINTER (t2),
2344 TREE_STRING_LENGTH (t1)));
2345
2346 case COMPLEX_CST:
2347 return (compare_constant (TREE_REALPART (t1), TREE_REALPART (t2))
2348 && compare_constant (TREE_IMAGPART (t1), TREE_IMAGPART (t2)));
2349
2350 case CONSTRUCTOR:
2351 typecode = TREE_CODE (TREE_TYPE (t1));
2352 if (typecode != TREE_CODE (TREE_TYPE (t2)))
2353 return 0;
2354
2355 if (typecode == SET_TYPE)
2356 {
2357 int len = int_size_in_bytes (TREE_TYPE (t2));
2358 unsigned char *tmp1, *tmp2;
2359
2360 if (int_size_in_bytes (TREE_TYPE (t1)) != len)
2361 return 0;
2362
2363 tmp1 = alloca (len);
2364 tmp2 = alloca (len);
2365
2366 if (get_set_constructor_bytes (t1, tmp1, len) != NULL_TREE)
2367 return 0;
2368 if (get_set_constructor_bytes (t2, tmp2, len) != NULL_TREE)
2369 return 0;
2370
2371 return memcmp (tmp1, tmp2, len) == 0;
2372 }
2373 else
2374 {
2375 tree l1, l2;
2376
2377 if (typecode == ARRAY_TYPE)
2378 {
2379 HOST_WIDE_INT size_1 = int_size_in_bytes (TREE_TYPE (t1));
2380 /* For arrays, check that the sizes all match. */
2381 if (TYPE_MODE (TREE_TYPE (t1)) != TYPE_MODE (TREE_TYPE (t2))
2382 || size_1 == -1
2383 || size_1 != int_size_in_bytes (TREE_TYPE (t2)))
2384 return 0;
2385 }
2386 else
2387 {
2388 /* For record and union constructors, require exact type
2389 equality. */
2390 if (TREE_TYPE (t1) != TREE_TYPE (t2))
2391 return 0;
2392 }
2393
2394 for (l1 = CONSTRUCTOR_ELTS (t1), l2 = CONSTRUCTOR_ELTS (t2);
2395 l1 && l2;
2396 l1 = TREE_CHAIN (l1), l2 = TREE_CHAIN (l2))
2397 {
2398 /* Check that each value is the same... */
2399 if (! compare_constant (TREE_VALUE (l1), TREE_VALUE (l2)))
2400 return 0;
2401 /* ... and that they apply to the same fields! */
2402 if (typecode == ARRAY_TYPE)
2403 {
2404 if (! compare_constant (TREE_PURPOSE (l1),
2405 TREE_PURPOSE (l2)))
2406 return 0;
2407 }
2408 else
2409 {
2410 if (TREE_PURPOSE (l1) != TREE_PURPOSE (l2))
2411 return 0;
2412 }
2413 }
2414
2415 return l1 == NULL_TREE && l2 == NULL_TREE;
2416 }
2417
2418 case ADDR_EXPR:
2419 case FDESC_EXPR:
2420 {
2421 struct addr_const value1, value2;
2422
2423 decode_addr_const (t1, &value1);
2424 decode_addr_const (t2, &value2);
2425 return (value1.offset == value2.offset
2426 && strcmp (XSTR (value1.base, 0), XSTR (value2.base, 0)) == 0);
2427 }
2428
2429 case PLUS_EXPR:
2430 case MINUS_EXPR:
2431 case RANGE_EXPR:
2432 return (compare_constant (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0))
2433 && compare_constant(TREE_OPERAND (t1, 1), TREE_OPERAND (t2, 1)));
2434
2435 case NOP_EXPR:
2436 case CONVERT_EXPR:
2437 case NON_LVALUE_EXPR:
2438 case VIEW_CONVERT_EXPR:
2439 return compare_constant (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
2440
2441 default:
2442 {
2443 tree nt1, nt2;
2444 nt1 = lang_hooks.expand_constant (t1);
2445 nt2 = lang_hooks.expand_constant (t2);
2446 if (nt1 != t1 || nt2 != t2)
2447 return compare_constant (nt1, nt2);
2448 else
2449 return 0;
2450 }
2451 }
2452
2453 /* Should not get here. */
2454 abort ();
2455 }
2456 \f
2457 /* Make a copy of the whole tree structure for a constant. This
2458 handles the same types of nodes that compare_constant handles. */
2459
2460 static tree
2461 copy_constant (tree exp)
2462 {
2463 switch (TREE_CODE (exp))
2464 {
2465 case ADDR_EXPR:
2466 /* For ADDR_EXPR, we do not want to copy the decl whose address
2467 is requested. We do want to copy constants though. */
2468 if (TREE_CODE_CLASS (TREE_CODE (TREE_OPERAND (exp, 0))) == 'c')
2469 return build1 (TREE_CODE (exp), TREE_TYPE (exp),
2470 copy_constant (TREE_OPERAND (exp, 0)));
2471 else
2472 return copy_node (exp);
2473
2474 case INTEGER_CST:
2475 case REAL_CST:
2476 case STRING_CST:
2477 return copy_node (exp);
2478
2479 case COMPLEX_CST:
2480 return build_complex (TREE_TYPE (exp),
2481 copy_constant (TREE_REALPART (exp)),
2482 copy_constant (TREE_IMAGPART (exp)));
2483
2484 case PLUS_EXPR:
2485 case MINUS_EXPR:
2486 return build2 (TREE_CODE (exp), TREE_TYPE (exp),
2487 copy_constant (TREE_OPERAND (exp, 0)),
2488 copy_constant (TREE_OPERAND (exp, 1)));
2489
2490 case NOP_EXPR:
2491 case CONVERT_EXPR:
2492 case NON_LVALUE_EXPR:
2493 case VIEW_CONVERT_EXPR:
2494 return build1 (TREE_CODE (exp), TREE_TYPE (exp),
2495 copy_constant (TREE_OPERAND (exp, 0)));
2496
2497 case CONSTRUCTOR:
2498 {
2499 tree copy = copy_node (exp);
2500 tree list = copy_list (CONSTRUCTOR_ELTS (exp));
2501 tree tail;
2502
2503 CONSTRUCTOR_ELTS (copy) = list;
2504 for (tail = list; tail; tail = TREE_CHAIN (tail))
2505 TREE_VALUE (tail) = copy_constant (TREE_VALUE (tail));
2506 if (TREE_CODE (TREE_TYPE (exp)) == SET_TYPE)
2507 for (tail = list; tail; tail = TREE_CHAIN (tail))
2508 TREE_PURPOSE (tail) = copy_constant (TREE_PURPOSE (tail));
2509
2510 return copy;
2511 }
2512
2513 default:
2514 {
2515 tree t;
2516 t = lang_hooks.expand_constant (exp);
2517 if (t != exp)
2518 return copy_constant (t);
2519 else
2520 abort ();
2521 }
2522 }
2523 }
2524 \f
2525 /* Subroutine of output_constant_def:
2526 No constant equal to EXP is known to have been output.
2527 Make a constant descriptor to enter EXP in the hash table.
2528 Assign the label number and construct RTL to refer to the
2529 constant's location in memory.
2530 Caller is responsible for updating the hash table. */
2531
2532 static struct constant_descriptor_tree *
2533 build_constant_desc (tree exp)
2534 {
2535 rtx symbol;
2536 rtx rtl;
2537 char label[256];
2538 int labelno;
2539 struct constant_descriptor_tree *desc;
2540
2541 desc = ggc_alloc (sizeof (*desc));
2542 desc->value = copy_constant (exp);
2543
2544 /* Propagate marked-ness to copied constant. */
2545 if (flag_mudflap && mf_marked_p (exp))
2546 mf_mark (desc->value);
2547
2548 /* Create a string containing the label name, in LABEL. */
2549 labelno = const_labelno++;
2550 ASM_GENERATE_INTERNAL_LABEL (label, "LC", labelno);
2551
2552 /* We have a symbol name; construct the SYMBOL_REF and the MEM. */
2553 symbol = gen_rtx_SYMBOL_REF (Pmode, ggc_strdup (label));
2554 SYMBOL_REF_FLAGS (symbol) = SYMBOL_FLAG_LOCAL;
2555 SYMBOL_REF_DECL (symbol) = desc->value;
2556 TREE_CONSTANT_POOL_ADDRESS_P (symbol) = 1;
2557
2558 rtl = gen_rtx_MEM (TYPE_MODE (TREE_TYPE (exp)), symbol);
2559 set_mem_attributes (rtl, exp, 1);
2560 set_mem_alias_set (rtl, 0);
2561 set_mem_alias_set (rtl, const_alias_set);
2562
2563 /* Set flags or add text to the name to record information, such as
2564 that it is a local symbol. If the name is changed, the macro
2565 ASM_OUTPUT_LABELREF will have to know how to strip this
2566 information. This call might invalidate our local variable
2567 SYMBOL; we can't use it afterward. */
2568
2569 targetm.encode_section_info (exp, rtl, true);
2570
2571 desc->rtl = rtl;
2572
2573 return desc;
2574 }
2575
2576 /* Return an rtx representing a reference to constant data in memory
2577 for the constant expression EXP.
2578
2579 If assembler code for such a constant has already been output,
2580 return an rtx to refer to it.
2581 Otherwise, output such a constant in memory
2582 and generate an rtx for it.
2583
2584 If DEFER is nonzero, this constant can be deferred and output only
2585 if referenced in the function after all optimizations.
2586
2587 `const_desc_table' records which constants already have label strings. */
2588
2589 rtx
2590 output_constant_def (tree exp, int defer)
2591 {
2592 struct constant_descriptor_tree *desc;
2593 struct constant_descriptor_tree key;
2594 void **loc;
2595
2596 /* Look up EXP in the table of constant descriptors. If we didn't find
2597 it, create a new one. */
2598 key.value = exp;
2599 loc = htab_find_slot (const_desc_htab, &key, INSERT);
2600
2601 desc = *loc;
2602 if (desc == 0)
2603 {
2604 desc = build_constant_desc (exp);
2605 *loc = desc;
2606 }
2607
2608 maybe_output_constant_def_contents (desc, defer);
2609 return desc->rtl;
2610 }
2611
2612 /* Subroutine of output_constant_def: Decide whether or not we need to
2613 output the constant DESC now, and if so, do it. */
2614 static void
2615 maybe_output_constant_def_contents (struct constant_descriptor_tree *desc,
2616 int defer)
2617 {
2618 rtx symbol = XEXP (desc->rtl, 0);
2619 tree exp = desc->value;
2620
2621 if (flag_syntax_only)
2622 return;
2623
2624 if (TREE_ASM_WRITTEN (exp))
2625 /* Already output; don't do it again. */
2626 return;
2627
2628 /* We can always defer constants as long as the context allows
2629 doing so. */
2630 if (defer)
2631 {
2632 /* Increment n_deferred_constants if it exists. It needs to be at
2633 least as large as the number of constants actually referred to
2634 by the function. If it's too small we'll stop looking too early
2635 and fail to emit constants; if it's too large we'll only look
2636 through the entire function when we could have stopped earlier. */
2637 if (cfun)
2638 n_deferred_constants++;
2639 return;
2640 }
2641
2642 output_constant_def_contents (symbol);
2643 }
2644
2645 /* We must output the constant data referred to by SYMBOL; do so. */
2646
2647 static void
2648 output_constant_def_contents (rtx symbol)
2649 {
2650 tree exp = SYMBOL_REF_DECL (symbol);
2651 const char *label = XSTR (symbol, 0);
2652 HOST_WIDE_INT size;
2653
2654 /* Make sure any other constants whose addresses appear in EXP
2655 are assigned label numbers. */
2656 int reloc = compute_reloc_for_constant (exp);
2657
2658 /* Align the location counter as required by EXP's data type. */
2659 unsigned int align = TYPE_ALIGN (TREE_TYPE (exp));
2660 #ifdef CONSTANT_ALIGNMENT
2661 align = CONSTANT_ALIGNMENT (exp, align);
2662 #endif
2663
2664 output_addressed_constants (exp);
2665
2666 /* We are no longer deferring this constant. */
2667 TREE_ASM_WRITTEN (exp) = 1;
2668
2669 if (IN_NAMED_SECTION (exp))
2670 named_section (exp, NULL, reloc);
2671 else
2672 targetm.asm_out.select_section (exp, reloc, align);
2673
2674 if (align > BITS_PER_UNIT)
2675 {
2676 ASM_OUTPUT_ALIGN (asm_out_file, floor_log2 (align / BITS_PER_UNIT));
2677 }
2678
2679 size = int_size_in_bytes (TREE_TYPE (exp));
2680 if (TREE_CODE (exp) == STRING_CST)
2681 size = MAX (TREE_STRING_LENGTH (exp), size);
2682
2683 /* Do any machine/system dependent processing of the constant. */
2684 #ifdef ASM_DECLARE_CONSTANT_NAME
2685 ASM_DECLARE_CONSTANT_NAME (asm_out_file, label, exp, size);
2686 #else
2687 /* Standard thing is just output label for the constant. */
2688 ASM_OUTPUT_LABEL (asm_out_file, label);
2689 #endif /* ASM_DECLARE_CONSTANT_NAME */
2690
2691 /* Output the value of EXP. */
2692 output_constant (exp, size, align);
2693 if (flag_mudflap)
2694 mudflap_enqueue_constant (exp);
2695 }
2696
2697 /* Look up EXP in the table of constant descriptors. Return the rtl
2698 if it has been emitted, else null. */
2699
2700 rtx
2701 lookup_constant_def (tree exp)
2702 {
2703 struct constant_descriptor_tree *desc;
2704 struct constant_descriptor_tree key;
2705
2706 key.value = exp;
2707 desc = htab_find (const_desc_htab, &key);
2708
2709 return (desc ? desc->rtl : NULL_RTX);
2710 }
2711 \f
2712 /* Used in the hash tables to avoid outputting the same constant
2713 twice. Unlike 'struct constant_descriptor_tree', RTX constants
2714 are output once per function, not once per file. */
2715 /* ??? Only a few targets need per-function constant pools. Most
2716 can use one per-file pool. Should add a targetm bit to tell the
2717 difference. */
2718
2719 struct rtx_constant_pool GTY(())
2720 {
2721 /* Pointers to first and last constant in pool, as ordered by offset. */
2722 struct constant_descriptor_rtx *first;
2723 struct constant_descriptor_rtx *last;
2724
2725 /* Hash facility for making memory-constants from constant rtl-expressions.
2726 It is used on RISC machines where immediate integer arguments and
2727 constant addresses are restricted so that such constants must be stored
2728 in memory. */
2729 htab_t GTY((param_is (struct constant_descriptor_rtx))) const_rtx_htab;
2730 htab_t GTY((param_is (struct constant_descriptor_rtx))) const_rtx_sym_htab;
2731
2732 /* Current offset in constant pool (does not include any
2733 machine-specific header). */
2734 HOST_WIDE_INT offset;
2735 };
2736
2737 struct constant_descriptor_rtx GTY((chain_next ("%h.next")))
2738 {
2739 struct constant_descriptor_rtx *next;
2740 rtx mem;
2741 rtx sym;
2742 rtx constant;
2743 HOST_WIDE_INT offset;
2744 hashval_t hash;
2745 enum machine_mode mode;
2746 unsigned int align;
2747 int labelno;
2748 int mark;
2749 };
2750
2751 /* Hash and compare functions for const_rtx_htab. */
2752
2753 static hashval_t
2754 const_desc_rtx_hash (const void *ptr)
2755 {
2756 const struct constant_descriptor_rtx *desc = ptr;
2757 return desc->hash;
2758 }
2759
2760 static int
2761 const_desc_rtx_eq (const void *a, const void *b)
2762 {
2763 const struct constant_descriptor_rtx *x = a;
2764 const struct constant_descriptor_rtx *y = b;
2765
2766 if (x->mode != y->mode)
2767 return 0;
2768 return rtx_equal_p (x->constant, y->constant);
2769 }
2770
2771 /* Hash and compare functions for const_rtx_sym_htab. */
2772
2773 static hashval_t
2774 const_desc_rtx_sym_hash (const void *ptr)
2775 {
2776 const struct constant_descriptor_rtx *desc = ptr;
2777 return htab_hash_string (XSTR (desc->sym, 0));
2778 }
2779
2780 static int
2781 const_desc_rtx_sym_eq (const void *a, const void *b)
2782 {
2783 const struct constant_descriptor_rtx *x = a;
2784 const struct constant_descriptor_rtx *y = b;
2785 return XSTR (x->sym, 0) == XSTR (y->sym, 0);
2786 }
2787
2788 /* This is the worker function for const_rtx_hash, called via for_each_rtx. */
2789
2790 static int
2791 const_rtx_hash_1 (rtx *xp, void *data)
2792 {
2793 unsigned HOST_WIDE_INT hwi;
2794 enum machine_mode mode;
2795 enum rtx_code code;
2796 hashval_t h, *hp;
2797 rtx x;
2798
2799 x = *xp;
2800 code = GET_CODE (x);
2801 mode = GET_MODE (x);
2802 h = (hashval_t) code * 1048573 + mode;
2803
2804 switch (code)
2805 {
2806 case CONST_INT:
2807 hwi = INTVAL (x);
2808 fold_hwi:
2809 {
2810 const int shift = sizeof (hashval_t) * CHAR_BIT;
2811 const int n = sizeof (HOST_WIDE_INT) / sizeof (hashval_t);
2812 int i;
2813
2814 h ^= (hashval_t) hwi;
2815 for (i = 1; i < n; ++i)
2816 {
2817 hwi >>= shift;
2818 h ^= (hashval_t) hwi;
2819 }
2820 }
2821 break;
2822
2823 case CONST_DOUBLE:
2824 if (mode == VOIDmode)
2825 {
2826 hwi = CONST_DOUBLE_LOW (x) ^ CONST_DOUBLE_HIGH (x);
2827 goto fold_hwi;
2828 }
2829 else
2830 h ^= real_hash (CONST_DOUBLE_REAL_VALUE (x));
2831 break;
2832
2833 case SYMBOL_REF:
2834 h ^= htab_hash_string (XSTR (x, 0));
2835 break;
2836
2837 case LABEL_REF:
2838 h = h * 251 + CODE_LABEL_NUMBER (XEXP (x, 0));
2839 break;
2840
2841 case UNSPEC:
2842 case UNSPEC_VOLATILE:
2843 h = h * 251 + XINT (x, 1);
2844 break;
2845
2846 default:
2847 break;
2848 }
2849
2850 hp = data;
2851 *hp = *hp * 509 + h;
2852 return 0;
2853 }
2854
2855 /* Compute a hash value for X, which should be a constant. */
2856
2857 static hashval_t
2858 const_rtx_hash (rtx x)
2859 {
2860 hashval_t h = 0;
2861 for_each_rtx (&x, const_rtx_hash_1, &h);
2862 return h;
2863 }
2864
2865 \f
2866 /* Initialize constant pool hashing for a new function. */
2867
2868 void
2869 init_varasm_status (struct function *f)
2870 {
2871 struct varasm_status *p;
2872 struct rtx_constant_pool *pool;
2873
2874 p = ggc_alloc (sizeof (struct varasm_status));
2875 f->varasm = p;
2876
2877 pool = ggc_alloc (sizeof (struct rtx_constant_pool));
2878 p->pool = pool;
2879 p->deferred_constants = 0;
2880
2881 pool->const_rtx_htab = htab_create_ggc (31, const_desc_rtx_hash,
2882 const_desc_rtx_eq, NULL);
2883 pool->const_rtx_sym_htab = htab_create_ggc (31, const_desc_rtx_sym_hash,
2884 const_desc_rtx_sym_eq, NULL);
2885 pool->first = pool->last = NULL;
2886 pool->offset = 0;
2887 }
2888 \f
2889 /* Given a MINUS expression, simplify it if both sides
2890 include the same symbol. */
2891
2892 rtx
2893 simplify_subtraction (rtx x)
2894 {
2895 rtx r = simplify_rtx (x);
2896 return r ? r : x;
2897 }
2898 \f
2899 /* Given a constant rtx X, make (or find) a memory constant for its value
2900 and return a MEM rtx to refer to it in memory. */
2901
2902 rtx
2903 force_const_mem (enum machine_mode mode, rtx x)
2904 {
2905 struct constant_descriptor_rtx *desc, tmp;
2906 struct rtx_constant_pool *pool = cfun->varasm->pool;
2907 char label[256];
2908 rtx def, symbol;
2909 hashval_t hash;
2910 unsigned int align;
2911 void **slot;
2912
2913 /* If we're not allowed to drop X into the constant pool, don't. */
2914 if (targetm.cannot_force_const_mem (x))
2915 return NULL_RTX;
2916
2917 /* Lookup the value in the hashtable. */
2918 tmp.constant = x;
2919 tmp.mode = mode;
2920 hash = const_rtx_hash (x);
2921 slot = htab_find_slot_with_hash (pool->const_rtx_htab, &tmp, hash, INSERT);
2922 desc = *slot;
2923
2924 /* If the constant was already present, return its memory. */
2925 if (desc)
2926 return copy_rtx (desc->mem);
2927
2928 /* Otherwise, create a new descriptor. */
2929 desc = ggc_alloc (sizeof (*desc));
2930 *slot = desc;
2931
2932 /* Align the location counter as required by EXP's data type. */
2933 align = GET_MODE_ALIGNMENT (mode == VOIDmode ? word_mode : mode);
2934 #ifdef CONSTANT_ALIGNMENT
2935 {
2936 tree type = lang_hooks.types.type_for_mode (mode, 0);
2937 if (type != NULL_TREE)
2938 align = CONSTANT_ALIGNMENT (make_tree (type, x), align);
2939 }
2940 #endif
2941
2942 pool->offset += (align / BITS_PER_UNIT) - 1;
2943 pool->offset &= ~ ((align / BITS_PER_UNIT) - 1);
2944
2945 desc->next = NULL;
2946 desc->constant = tmp.constant;
2947 desc->offset = pool->offset;
2948 desc->hash = hash;
2949 desc->mode = mode;
2950 desc->align = align;
2951 desc->labelno = const_labelno;
2952 desc->mark = 0;
2953
2954 pool->offset += GET_MODE_SIZE (mode);
2955 if (pool->last)
2956 pool->last->next = desc;
2957 else
2958 pool->first = pool->last = desc;
2959 pool->last = desc;
2960
2961 /* Create a string containing the label name, in LABEL. */
2962 ASM_GENERATE_INTERNAL_LABEL (label, "LC", const_labelno);
2963 ++const_labelno;
2964
2965 /* Construct the SYMBOL_REF. Make sure to mark it as belonging to
2966 the constants pool. */
2967 desc->sym = symbol = gen_rtx_SYMBOL_REF (Pmode, ggc_strdup (label));
2968 SYMBOL_REF_FLAGS (symbol) = SYMBOL_FLAG_LOCAL;
2969 CONSTANT_POOL_ADDRESS_P (symbol) = 1;
2970 current_function_uses_const_pool = 1;
2971
2972 /* Insert the descriptor into the symbol cross-reference table too. */
2973 slot = htab_find_slot (pool->const_rtx_sym_htab, desc, INSERT);
2974 if (*slot)
2975 abort ();
2976 *slot = desc;
2977
2978 /* Construct the MEM. */
2979 desc->mem = def = gen_const_mem (mode, symbol);
2980 set_mem_attributes (def, lang_hooks.types.type_for_mode (mode, 0), 1);
2981
2982 /* If we're dropping a label to the constant pool, make sure we
2983 don't delete it. */
2984 if (GET_CODE (x) == LABEL_REF)
2985 LABEL_PRESERVE_P (XEXP (x, 0)) = 1;
2986
2987 return copy_rtx (def);
2988 }
2989 \f
2990 /* Given a SYMBOL_REF with CONSTANT_POOL_ADDRESS_P true, return a pointer to
2991 the corresponding constant_descriptor_rtx structure. */
2992
2993 static struct constant_descriptor_rtx *
2994 find_pool_constant (struct rtx_constant_pool *pool, rtx sym)
2995 {
2996 struct constant_descriptor_rtx tmp;
2997 tmp.sym = sym;
2998 return htab_find (pool->const_rtx_sym_htab, &tmp);
2999 }
3000
3001 /* Given a constant pool SYMBOL_REF, return the corresponding constant. */
3002
3003 rtx
3004 get_pool_constant (rtx addr)
3005 {
3006 return find_pool_constant (cfun->varasm->pool, addr)->constant;
3007 }
3008
3009 /* Given a constant pool SYMBOL_REF, return the corresponding constant
3010 and whether it has been output or not. */
3011
3012 rtx
3013 get_pool_constant_mark (rtx addr, bool *pmarked)
3014 {
3015 struct constant_descriptor_rtx *desc;
3016
3017 desc = find_pool_constant (cfun->varasm->pool, addr);
3018 *pmarked = (desc->mark != 0);
3019 return desc->constant;
3020 }
3021
3022 /* Likewise, but for the constant pool of a specific function. */
3023
3024 rtx
3025 get_pool_constant_for_function (struct function *f, rtx addr)
3026 {
3027 return find_pool_constant (f->varasm->pool, addr)->constant;
3028 }
3029
3030 /* Similar, return the mode. */
3031
3032 enum machine_mode
3033 get_pool_mode (rtx addr)
3034 {
3035 return find_pool_constant (cfun->varasm->pool, addr)->mode;
3036 }
3037
3038 enum machine_mode
3039 get_pool_mode_for_function (struct function *f, rtx addr)
3040 {
3041 return find_pool_constant (f->varasm->pool, addr)->mode;
3042 }
3043
3044 /* Similar, return the offset in the constant pool. */
3045
3046 int
3047 get_pool_offset (rtx addr)
3048 {
3049 return find_pool_constant (cfun->varasm->pool, addr)->offset;
3050 }
3051
3052 /* Return the size of the constant pool. */
3053
3054 int
3055 get_pool_size (void)
3056 {
3057 return cfun->varasm->pool->offset;
3058 }
3059 \f
3060 /* Worker function for output_constant_pool_1. Emit assembly for X
3061 in MODE with known alignment ALIGN. */
3062
3063 static void
3064 output_constant_pool_2 (enum machine_mode mode, rtx x, unsigned int align)
3065 {
3066 switch (GET_MODE_CLASS (mode))
3067 {
3068 case MODE_FLOAT:
3069 if (GET_CODE (x) != CONST_DOUBLE)
3070 abort ();
3071 else
3072 {
3073 REAL_VALUE_TYPE r;
3074 REAL_VALUE_FROM_CONST_DOUBLE (r, x);
3075 assemble_real (r, mode, align);
3076 }
3077 break;
3078
3079 case MODE_INT:
3080 case MODE_PARTIAL_INT:
3081 assemble_integer (x, GET_MODE_SIZE (mode), align, 1);
3082 break;
3083
3084 case MODE_VECTOR_FLOAT:
3085 case MODE_VECTOR_INT:
3086 {
3087 int i, units;
3088 enum machine_mode submode = GET_MODE_INNER (mode);
3089 unsigned int subalign = MIN (align, GET_MODE_BITSIZE (submode));
3090
3091 if (GET_CODE (x) != CONST_VECTOR)
3092 abort ();
3093 units = CONST_VECTOR_NUNITS (x);
3094
3095 for (i = 0; i < units; i++)
3096 {
3097 rtx elt = CONST_VECTOR_ELT (x, i);
3098 output_constant_pool_2 (submode, elt, i ? subalign : align);
3099 }
3100 }
3101 break;
3102
3103 default:
3104 abort ();
3105 }
3106 }
3107
3108 /* Worker function for output_constant_pool. Emit POOL. */
3109
3110 static void
3111 output_constant_pool_1 (struct constant_descriptor_rtx *desc)
3112 {
3113 rtx x, tmp;
3114
3115 if (!desc->mark)
3116 return;
3117 x = desc->constant;
3118
3119 /* See if X is a LABEL_REF (or a CONST referring to a LABEL_REF)
3120 whose CODE_LABEL has been deleted. This can occur if a jump table
3121 is eliminated by optimization. If so, write a constant of zero
3122 instead. Note that this can also happen by turning the
3123 CODE_LABEL into a NOTE. */
3124 /* ??? This seems completely and utterly wrong. Certainly it's
3125 not true for NOTE_INSN_DELETED_LABEL, but I disbelieve proper
3126 functioning even with INSN_DELETED_P and friends. */
3127
3128 tmp = x;
3129 switch (GET_CODE (x))
3130 {
3131 case CONST:
3132 if (GET_CODE (XEXP (x, 0)) != PLUS
3133 || GET_CODE (XEXP (XEXP (x, 0), 0)) != LABEL_REF)
3134 break;
3135 tmp = XEXP (XEXP (x, 0), 0);
3136 /* FALLTHRU */
3137
3138 case LABEL_REF:
3139 tmp = XEXP (x, 0);
3140 if (INSN_DELETED_P (tmp)
3141 || (NOTE_P (tmp)
3142 && NOTE_LINE_NUMBER (tmp) == NOTE_INSN_DELETED))
3143 {
3144 abort ();
3145 x = const0_rtx;
3146 }
3147 break;
3148
3149 default:
3150 break;
3151 }
3152
3153 /* First switch to correct section. */
3154 targetm.asm_out.select_rtx_section (desc->mode, x, desc->align);
3155
3156 #ifdef ASM_OUTPUT_SPECIAL_POOL_ENTRY
3157 ASM_OUTPUT_SPECIAL_POOL_ENTRY (asm_out_file, x, desc->mode,
3158 desc->align, desc->labelno, done);
3159 #endif
3160
3161 assemble_align (desc->align);
3162
3163 /* Output the label. */
3164 targetm.asm_out.internal_label (asm_out_file, "LC", desc->labelno);
3165
3166 /* Output the data. */
3167 output_constant_pool_2 (desc->mode, x, desc->align);
3168
3169 /* Make sure all constants in SECTION_MERGE and not SECTION_STRINGS
3170 sections have proper size. */
3171 if (desc->align > GET_MODE_BITSIZE (desc->mode)
3172 && in_section == in_named
3173 && get_named_section_flags (in_named_name) & SECTION_MERGE)
3174 assemble_align (desc->align);
3175
3176 #ifdef ASM_OUTPUT_SPECIAL_POOL_ENTRY
3177 done:
3178 #endif
3179 return;
3180 }
3181
3182 /* Given a SYMBOL_REF CURRENT_RTX, mark it and all constants it refers
3183 to as used. Emit referenced deferred strings. This function can
3184 be used with for_each_rtx to mark all SYMBOL_REFs in an rtx. */
3185
3186 static int
3187 mark_constant (rtx *current_rtx, void *data)
3188 {
3189 struct rtx_constant_pool *pool = data;
3190 rtx x = *current_rtx;
3191
3192 if (x == NULL_RTX || GET_CODE (x) != SYMBOL_REF)
3193 return 0;
3194
3195 if (CONSTANT_POOL_ADDRESS_P (x))
3196 {
3197 struct constant_descriptor_rtx *desc = find_pool_constant (pool, x);
3198 if (desc->mark == 0)
3199 {
3200 desc->mark = 1;
3201 for_each_rtx (&desc->constant, mark_constant, pool);
3202 }
3203 }
3204 else if (TREE_CONSTANT_POOL_ADDRESS_P (x))
3205 {
3206 tree exp = SYMBOL_REF_DECL (x);
3207 if (!TREE_ASM_WRITTEN (exp))
3208 {
3209 n_deferred_constants--;
3210 output_constant_def_contents (x);
3211 }
3212 }
3213
3214 return -1;
3215 }
3216
3217 /* Look through appropriate parts of INSN, marking all entries in the
3218 constant pool which are actually being used. Entries that are only
3219 referenced by other constants are also marked as used. Emit
3220 deferred strings that are used. */
3221
3222 static void
3223 mark_constants (struct rtx_constant_pool *pool, rtx insn)
3224 {
3225 if (!INSN_P (insn))
3226 return;
3227
3228 /* Insns may appear inside a SEQUENCE. Only check the patterns of
3229 insns, not any notes that may be attached. We don't want to mark
3230 a constant just because it happens to appear in a REG_EQUIV note. */
3231 if (GET_CODE (PATTERN (insn)) == SEQUENCE)
3232 {
3233 rtx seq = PATTERN (insn);
3234 int i, n = XVECLEN (seq, 0);
3235 for (i = 0; i < n; ++i)
3236 {
3237 rtx subinsn = XVECEXP (seq, 0, i);
3238 if (INSN_P (subinsn))
3239 for_each_rtx (&PATTERN (subinsn), mark_constant, pool);
3240 }
3241 }
3242 else
3243 for_each_rtx (&PATTERN (insn), mark_constant, pool);
3244 }
3245
3246 /* Look through the instructions for this function, and mark all the
3247 entries in POOL which are actually being used. Emit deferred constants
3248 which have indeed been used. */
3249
3250 static void
3251 mark_constant_pool (struct rtx_constant_pool *pool)
3252 {
3253 rtx insn, link;
3254
3255 if (pool->first == 0 && n_deferred_constants == 0)
3256 return;
3257
3258 for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
3259 mark_constants (pool, insn);
3260
3261 for (link = current_function_epilogue_delay_list;
3262 link;
3263 link = XEXP (link, 1))
3264 mark_constants (pool, XEXP (link, 0));
3265 }
3266
3267 /* Write all the constants in the constant pool. */
3268
3269 void
3270 output_constant_pool (const char *fnname ATTRIBUTE_UNUSED,
3271 tree fndecl ATTRIBUTE_UNUSED)
3272 {
3273 struct rtx_constant_pool *pool = cfun->varasm->pool;
3274 struct constant_descriptor_rtx *desc;
3275
3276 /* It is possible for gcc to call force_const_mem and then to later
3277 discard the instructions which refer to the constant. In such a
3278 case we do not need to output the constant. */
3279 mark_constant_pool (pool);
3280
3281 #ifdef ASM_OUTPUT_POOL_PROLOGUE
3282 ASM_OUTPUT_POOL_PROLOGUE (asm_out_file, fnname, fndecl, pool->offset);
3283 #endif
3284
3285 for (desc = pool->first; desc ; desc = desc->next)
3286 output_constant_pool_1 (desc);
3287
3288 #ifdef ASM_OUTPUT_POOL_EPILOGUE
3289 ASM_OUTPUT_POOL_EPILOGUE (asm_out_file, fnname, fndecl, pool->offset);
3290 #endif
3291 }
3292 \f
3293 /* Determine what kind of relocations EXP may need. */
3294
3295 int
3296 compute_reloc_for_constant (tree exp)
3297 {
3298 int reloc = 0, reloc2;
3299 tree tem;
3300
3301 /* Give the front-end a chance to convert VALUE to something that
3302 looks more like a constant to the back-end. */
3303 exp = lang_hooks.expand_constant (exp);
3304
3305 switch (TREE_CODE (exp))
3306 {
3307 case ADDR_EXPR:
3308 case FDESC_EXPR:
3309 /* Go inside any operations that get_inner_reference can handle and see
3310 if what's inside is a constant: no need to do anything here for
3311 addresses of variables or functions. */
3312 for (tem = TREE_OPERAND (exp, 0); handled_component_p (tem);
3313 tem = TREE_OPERAND (tem, 0))
3314 ;
3315
3316 if (TREE_PUBLIC (tem))
3317 reloc |= 2;
3318 else
3319 reloc |= 1;
3320 break;
3321
3322 case PLUS_EXPR:
3323 reloc = compute_reloc_for_constant (TREE_OPERAND (exp, 0));
3324 reloc |= compute_reloc_for_constant (TREE_OPERAND (exp, 1));
3325 break;
3326
3327 case MINUS_EXPR:
3328 reloc = compute_reloc_for_constant (TREE_OPERAND (exp, 0));
3329 reloc2 = compute_reloc_for_constant (TREE_OPERAND (exp, 1));
3330 /* The difference of two local labels is computable at link time. */
3331 if (reloc == 1 && reloc2 == 1)
3332 reloc = 0;
3333 else
3334 reloc |= reloc2;
3335 break;
3336
3337 case NOP_EXPR:
3338 case CONVERT_EXPR:
3339 case NON_LVALUE_EXPR:
3340 reloc = compute_reloc_for_constant (TREE_OPERAND (exp, 0));
3341 break;
3342
3343 case CONSTRUCTOR:
3344 for (tem = CONSTRUCTOR_ELTS (exp); tem; tem = TREE_CHAIN (tem))
3345 if (TREE_VALUE (tem) != 0)
3346 reloc |= compute_reloc_for_constant (TREE_VALUE (tem));
3347
3348 break;
3349
3350 default:
3351 break;
3352 }
3353 return reloc;
3354 }
3355
3356 /* Find all the constants whose addresses are referenced inside of EXP,
3357 and make sure assembler code with a label has been output for each one.
3358 Indicate whether an ADDR_EXPR has been encountered. */
3359
3360 static void
3361 output_addressed_constants (tree exp)
3362 {
3363 tree tem;
3364
3365 /* Give the front-end a chance to convert VALUE to something that
3366 looks more like a constant to the back-end. */
3367 exp = lang_hooks.expand_constant (exp);
3368
3369 switch (TREE_CODE (exp))
3370 {
3371 case ADDR_EXPR:
3372 case FDESC_EXPR:
3373 /* Go inside any operations that get_inner_reference can handle and see
3374 if what's inside is a constant: no need to do anything here for
3375 addresses of variables or functions. */
3376 for (tem = TREE_OPERAND (exp, 0); handled_component_p (tem);
3377 tem = TREE_OPERAND (tem, 0))
3378 ;
3379
3380 if (TREE_CODE_CLASS (TREE_CODE (tem)) == 'c'
3381 || TREE_CODE (tem) == CONSTRUCTOR)
3382 output_constant_def (tem, 0);
3383 break;
3384
3385 case PLUS_EXPR:
3386 case MINUS_EXPR:
3387 output_addressed_constants (TREE_OPERAND (exp, 1));
3388 /* Fall through. */
3389
3390 case NOP_EXPR:
3391 case CONVERT_EXPR:
3392 case NON_LVALUE_EXPR:
3393 output_addressed_constants (TREE_OPERAND (exp, 0));
3394 break;
3395
3396 case CONSTRUCTOR:
3397 for (tem = CONSTRUCTOR_ELTS (exp); tem; tem = TREE_CHAIN (tem))
3398 if (TREE_VALUE (tem) != 0)
3399 output_addressed_constants (TREE_VALUE (tem));
3400
3401 break;
3402
3403 default:
3404 break;
3405 }
3406 }
3407 \f
3408 /* Return nonzero if VALUE is a valid constant-valued expression
3409 for use in initializing a static variable; one that can be an
3410 element of a "constant" initializer.
3411
3412 Return null_pointer_node if the value is absolute;
3413 if it is relocatable, return the variable that determines the relocation.
3414 We assume that VALUE has been folded as much as possible;
3415 therefore, we do not need to check for such things as
3416 arithmetic-combinations of integers. */
3417
3418 tree
3419 initializer_constant_valid_p (tree value, tree endtype)
3420 {
3421 /* Give the front-end a chance to convert VALUE to something that
3422 looks more like a constant to the back-end. */
3423 value = lang_hooks.expand_constant (value);
3424
3425 switch (TREE_CODE (value))
3426 {
3427 case CONSTRUCTOR:
3428 if ((TREE_CODE (TREE_TYPE (value)) == UNION_TYPE
3429 || TREE_CODE (TREE_TYPE (value)) == RECORD_TYPE)
3430 && TREE_CONSTANT (value)
3431 && CONSTRUCTOR_ELTS (value))
3432 {
3433 tree elt;
3434 bool absolute = true;
3435
3436 for (elt = CONSTRUCTOR_ELTS (value); elt; elt = TREE_CHAIN (elt))
3437 {
3438 tree reloc;
3439 value = TREE_VALUE (elt);
3440 reloc = initializer_constant_valid_p (value, TREE_TYPE (value));
3441 if (!reloc)
3442 return NULL_TREE;
3443 if (reloc != null_pointer_node)
3444 absolute = false;
3445 }
3446 /* For a non-absolute relocation, there is no single
3447 variable that can be "the variable that determines the
3448 relocation." */
3449 return absolute ? null_pointer_node : error_mark_node;
3450 }
3451
3452 return TREE_STATIC (value) ? null_pointer_node : NULL_TREE;
3453
3454 case INTEGER_CST:
3455 case VECTOR_CST:
3456 case REAL_CST:
3457 case STRING_CST:
3458 case COMPLEX_CST:
3459 return null_pointer_node;
3460
3461 case ADDR_EXPR:
3462 case FDESC_EXPR:
3463 value = staticp (TREE_OPERAND (value, 0));
3464 /* "&(*a).f" is like unto pointer arithmetic. If "a" turns out to
3465 be a constant, this is old-skool offsetof-like nonsense. */
3466 if (value
3467 && TREE_CODE (value) == INDIRECT_REF
3468 && TREE_CONSTANT (TREE_OPERAND (value, 0)))
3469 return null_pointer_node;
3470 return value;
3471
3472 case VIEW_CONVERT_EXPR:
3473 case NON_LVALUE_EXPR:
3474 return initializer_constant_valid_p (TREE_OPERAND (value, 0), endtype);
3475
3476 case CONVERT_EXPR:
3477 case NOP_EXPR:
3478 /* Allow conversions between pointer types. */
3479 if (POINTER_TYPE_P (TREE_TYPE (value))
3480 && POINTER_TYPE_P (TREE_TYPE (TREE_OPERAND (value, 0))))
3481 return initializer_constant_valid_p (TREE_OPERAND (value, 0), endtype);
3482
3483 /* Allow conversions between real types. */
3484 if (FLOAT_TYPE_P (TREE_TYPE (value))
3485 && FLOAT_TYPE_P (TREE_TYPE (TREE_OPERAND (value, 0))))
3486 return initializer_constant_valid_p (TREE_OPERAND (value, 0), endtype);
3487
3488 /* Allow length-preserving conversions between integer types. */
3489 if (INTEGRAL_TYPE_P (TREE_TYPE (value))
3490 && INTEGRAL_TYPE_P (TREE_TYPE (TREE_OPERAND (value, 0)))
3491 && (TYPE_PRECISION (TREE_TYPE (value))
3492 == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (value, 0)))))
3493 return initializer_constant_valid_p (TREE_OPERAND (value, 0), endtype);
3494
3495 /* Allow conversions between other integer types only if
3496 explicit value. */
3497 if (INTEGRAL_TYPE_P (TREE_TYPE (value))
3498 && INTEGRAL_TYPE_P (TREE_TYPE (TREE_OPERAND (value, 0))))
3499 {
3500 tree inner = initializer_constant_valid_p (TREE_OPERAND (value, 0),
3501 endtype);
3502 if (inner == null_pointer_node)
3503 return null_pointer_node;
3504 break;
3505 }
3506
3507 /* Allow (int) &foo provided int is as wide as a pointer. */
3508 if (INTEGRAL_TYPE_P (TREE_TYPE (value))
3509 && POINTER_TYPE_P (TREE_TYPE (TREE_OPERAND (value, 0)))
3510 && (TYPE_PRECISION (TREE_TYPE (value))
3511 >= TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (value, 0)))))
3512 return initializer_constant_valid_p (TREE_OPERAND (value, 0),
3513 endtype);
3514
3515 /* Likewise conversions from int to pointers, but also allow
3516 conversions from 0. */
3517 if ((POINTER_TYPE_P (TREE_TYPE (value))
3518 || TREE_CODE (TREE_TYPE (value)) == OFFSET_TYPE)
3519 && INTEGRAL_TYPE_P (TREE_TYPE (TREE_OPERAND (value, 0))))
3520 {
3521 if (integer_zerop (TREE_OPERAND (value, 0)))
3522 return null_pointer_node;
3523 else if (TYPE_PRECISION (TREE_TYPE (value))
3524 <= TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (value, 0))))
3525 return initializer_constant_valid_p (TREE_OPERAND (value, 0),
3526 endtype);
3527 }
3528
3529 /* Allow conversions to struct or union types if the value
3530 inside is okay. */
3531 if (TREE_CODE (TREE_TYPE (value)) == RECORD_TYPE
3532 || TREE_CODE (TREE_TYPE (value)) == UNION_TYPE)
3533 return initializer_constant_valid_p (TREE_OPERAND (value, 0),
3534 endtype);
3535 break;
3536
3537 case PLUS_EXPR:
3538 if (! INTEGRAL_TYPE_P (endtype)
3539 || TYPE_PRECISION (endtype) >= POINTER_SIZE)
3540 {
3541 tree valid0 = initializer_constant_valid_p (TREE_OPERAND (value, 0),
3542 endtype);
3543 tree valid1 = initializer_constant_valid_p (TREE_OPERAND (value, 1),
3544 endtype);
3545 /* If either term is absolute, use the other terms relocation. */
3546 if (valid0 == null_pointer_node)
3547 return valid1;
3548 if (valid1 == null_pointer_node)
3549 return valid0;
3550 }
3551 break;
3552
3553 case MINUS_EXPR:
3554 if (! INTEGRAL_TYPE_P (endtype)
3555 || TYPE_PRECISION (endtype) >= POINTER_SIZE)
3556 {
3557 tree valid0 = initializer_constant_valid_p (TREE_OPERAND (value, 0),
3558 endtype);
3559 tree valid1 = initializer_constant_valid_p (TREE_OPERAND (value, 1),
3560 endtype);
3561 /* Win if second argument is absolute. */
3562 if (valid1 == null_pointer_node)
3563 return valid0;
3564 /* Win if both arguments have the same relocation.
3565 Then the value is absolute. */
3566 if (valid0 == valid1 && valid0 != 0)
3567 return null_pointer_node;
3568
3569 /* Since GCC guarantees that string constants are unique in the
3570 generated code, a subtraction between two copies of the same
3571 constant string is absolute. */
3572 if (valid0 && TREE_CODE (valid0) == STRING_CST
3573 && valid1 && TREE_CODE (valid1) == STRING_CST
3574 && operand_equal_p (valid0, valid1, 1))
3575 return null_pointer_node;
3576 }
3577
3578 /* Support narrowing differences. */
3579 if (INTEGRAL_TYPE_P (endtype))
3580 {
3581 tree op0, op1;
3582
3583 op0 = TREE_OPERAND (value, 0);
3584 op1 = TREE_OPERAND (value, 1);
3585
3586 /* Like STRIP_NOPS except allow the operand mode to widen.
3587 This works around a feature of fold that simplifies
3588 (int)(p1 - p2) to ((int)p1 - (int)p2) under the theory
3589 that the narrower operation is cheaper. */
3590
3591 while (TREE_CODE (op0) == NOP_EXPR
3592 || TREE_CODE (op0) == CONVERT_EXPR
3593 || TREE_CODE (op0) == NON_LVALUE_EXPR)
3594 {
3595 tree inner = TREE_OPERAND (op0, 0);
3596 if (inner == error_mark_node
3597 || ! INTEGRAL_MODE_P (TYPE_MODE (TREE_TYPE (inner)))
3598 || (GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op0)))
3599 > GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (inner)))))
3600 break;
3601 op0 = inner;
3602 }
3603
3604 while (TREE_CODE (op1) == NOP_EXPR
3605 || TREE_CODE (op1) == CONVERT_EXPR
3606 || TREE_CODE (op1) == NON_LVALUE_EXPR)
3607 {
3608 tree inner = TREE_OPERAND (op1, 0);
3609 if (inner == error_mark_node
3610 || ! INTEGRAL_MODE_P (TYPE_MODE (TREE_TYPE (inner)))
3611 || (GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op1)))
3612 > GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (inner)))))
3613 break;
3614 op1 = inner;
3615 }
3616
3617 op0 = initializer_constant_valid_p (op0, endtype);
3618 op1 = initializer_constant_valid_p (op1, endtype);
3619
3620 /* Both initializers must be known. */
3621 if (op0 && op1)
3622 {
3623 if (op0 == op1)
3624 return null_pointer_node;
3625
3626 /* Support differences between labels. */
3627 if (TREE_CODE (op0) == LABEL_DECL
3628 && TREE_CODE (op1) == LABEL_DECL)
3629 return null_pointer_node;
3630
3631 if (TREE_CODE (op0) == STRING_CST
3632 && TREE_CODE (op1) == STRING_CST
3633 && operand_equal_p (op0, op1, 1))
3634 return null_pointer_node;
3635 }
3636 }
3637 break;
3638
3639 default:
3640 break;
3641 }
3642
3643 return 0;
3644 }
3645 \f
3646 /* Output assembler code for constant EXP to FILE, with no label.
3647 This includes the pseudo-op such as ".int" or ".byte", and a newline.
3648 Assumes output_addressed_constants has been done on EXP already.
3649
3650 Generate exactly SIZE bytes of assembler data, padding at the end
3651 with zeros if necessary. SIZE must always be specified.
3652
3653 SIZE is important for structure constructors,
3654 since trailing members may have been omitted from the constructor.
3655 It is also important for initialization of arrays from string constants
3656 since the full length of the string constant might not be wanted.
3657 It is also needed for initialization of unions, where the initializer's
3658 type is just one member, and that may not be as long as the union.
3659
3660 There a case in which we would fail to output exactly SIZE bytes:
3661 for a structure constructor that wants to produce more than SIZE bytes.
3662 But such constructors will never be generated for any possible input.
3663
3664 ALIGN is the alignment of the data in bits. */
3665
3666 void
3667 output_constant (tree exp, unsigned HOST_WIDE_INT size, unsigned int align)
3668 {
3669 enum tree_code code;
3670 unsigned HOST_WIDE_INT thissize;
3671
3672 /* Some front-ends use constants other than the standard language-independent
3673 varieties, but which may still be output directly. Give the front-end a
3674 chance to convert EXP to a language-independent representation. */
3675 exp = lang_hooks.expand_constant (exp);
3676
3677 if (size == 0 || flag_syntax_only)
3678 return;
3679
3680 /* Eliminate any conversions since we'll be outputting the underlying
3681 constant. */
3682 while (TREE_CODE (exp) == NOP_EXPR || TREE_CODE (exp) == CONVERT_EXPR
3683 || TREE_CODE (exp) == NON_LVALUE_EXPR
3684 || TREE_CODE (exp) == VIEW_CONVERT_EXPR)
3685 exp = TREE_OPERAND (exp, 0);
3686
3687 code = TREE_CODE (TREE_TYPE (exp));
3688 thissize = int_size_in_bytes (TREE_TYPE (exp));
3689
3690 /* Allow a constructor with no elements for any data type.
3691 This means to fill the space with zeros. */
3692 if (TREE_CODE (exp) == CONSTRUCTOR && CONSTRUCTOR_ELTS (exp) == 0)
3693 {
3694 assemble_zeros (size);
3695 return;
3696 }
3697
3698 if (TREE_CODE (exp) == FDESC_EXPR)
3699 {
3700 #ifdef ASM_OUTPUT_FDESC
3701 HOST_WIDE_INT part = tree_low_cst (TREE_OPERAND (exp, 1), 0);
3702 tree decl = TREE_OPERAND (exp, 0);
3703 ASM_OUTPUT_FDESC (asm_out_file, decl, part);
3704 #else
3705 abort ();
3706 #endif
3707 return;
3708 }
3709
3710 /* Now output the underlying data. If we've handling the padding, return.
3711 Otherwise, break and ensure SIZE is the size written. */
3712 switch (code)
3713 {
3714 case CHAR_TYPE:
3715 case BOOLEAN_TYPE:
3716 case INTEGER_TYPE:
3717 case ENUMERAL_TYPE:
3718 case POINTER_TYPE:
3719 case REFERENCE_TYPE:
3720 case OFFSET_TYPE:
3721 if (! assemble_integer (expand_expr (exp, NULL_RTX, VOIDmode,
3722 EXPAND_INITIALIZER),
3723 MIN (size, thissize), align, 0))
3724 error ("initializer for integer value is too complicated");
3725 break;
3726
3727 case REAL_TYPE:
3728 if (TREE_CODE (exp) != REAL_CST)
3729 error ("initializer for floating value is not a floating constant");
3730
3731 assemble_real (TREE_REAL_CST (exp), TYPE_MODE (TREE_TYPE (exp)), align);
3732 break;
3733
3734 case COMPLEX_TYPE:
3735 output_constant (TREE_REALPART (exp), thissize / 2, align);
3736 output_constant (TREE_IMAGPART (exp), thissize / 2,
3737 min_align (align, BITS_PER_UNIT * (thissize / 2)));
3738 break;
3739
3740 case ARRAY_TYPE:
3741 case VECTOR_TYPE:
3742 if (TREE_CODE (exp) == CONSTRUCTOR)
3743 {
3744 output_constructor (exp, size, align);
3745 return;
3746 }
3747 else if (TREE_CODE (exp) == STRING_CST)
3748 {
3749 thissize = MIN ((unsigned HOST_WIDE_INT)TREE_STRING_LENGTH (exp),
3750 size);
3751 assemble_string (TREE_STRING_POINTER (exp), thissize);
3752 }
3753 else if (TREE_CODE (exp) == VECTOR_CST)
3754 {
3755 int elt_size;
3756 tree link;
3757 unsigned int nalign;
3758 enum machine_mode inner;
3759
3760 inner = TYPE_MODE (TREE_TYPE (TREE_TYPE (exp)));
3761 nalign = MIN (align, GET_MODE_ALIGNMENT (inner));
3762
3763 elt_size = GET_MODE_SIZE (inner);
3764
3765 link = TREE_VECTOR_CST_ELTS (exp);
3766 output_constant (TREE_VALUE (link), elt_size, align);
3767 while ((link = TREE_CHAIN (link)) != NULL)
3768 output_constant (TREE_VALUE (link), elt_size, nalign);
3769 }
3770 else
3771 abort ();
3772 break;
3773
3774 case RECORD_TYPE:
3775 case UNION_TYPE:
3776 if (TREE_CODE (exp) == CONSTRUCTOR)
3777 output_constructor (exp, size, align);
3778 else
3779 abort ();
3780 return;
3781
3782 case SET_TYPE:
3783 if (TREE_CODE (exp) == INTEGER_CST)
3784 assemble_integer (expand_expr (exp, NULL_RTX,
3785 VOIDmode, EXPAND_INITIALIZER),
3786 thissize, align, 1);
3787 else if (TREE_CODE (exp) == CONSTRUCTOR)
3788 {
3789 unsigned char *buffer = alloca (thissize);
3790 if (get_set_constructor_bytes (exp, buffer, thissize))
3791 abort ();
3792 assemble_string ((char *) buffer, thissize);
3793 }
3794 else
3795 error ("unknown set constructor type");
3796 return;
3797
3798 case ERROR_MARK:
3799 return;
3800
3801 default:
3802 abort ();
3803 }
3804
3805 if (size > thissize)
3806 assemble_zeros (size - thissize);
3807 }
3808
3809 \f
3810 /* Subroutine of output_constructor, used for computing the size of
3811 arrays of unspecified length. VAL must be a CONSTRUCTOR of an array
3812 type with an unspecified upper bound. */
3813
3814 static unsigned HOST_WIDE_INT
3815 array_size_for_constructor (tree val)
3816 {
3817 tree max_index, i;
3818
3819 /* This code used to attempt to handle string constants that are not
3820 arrays of single-bytes, but nothing else does, so there's no point in
3821 doing it here. */
3822 if (TREE_CODE (val) == STRING_CST)
3823 return TREE_STRING_LENGTH (val);
3824
3825 max_index = NULL_TREE;
3826 for (i = CONSTRUCTOR_ELTS (val); i; i = TREE_CHAIN (i))
3827 {
3828 tree index = TREE_PURPOSE (i);
3829
3830 if (TREE_CODE (index) == RANGE_EXPR)
3831 index = TREE_OPERAND (index, 1);
3832 if (max_index == NULL_TREE || tree_int_cst_lt (max_index, index))
3833 max_index = index;
3834 }
3835
3836 if (max_index == NULL_TREE)
3837 return 0;
3838
3839 /* Compute the total number of array elements. */
3840 i = size_binop (MINUS_EXPR, convert (sizetype, max_index),
3841 convert (sizetype,
3842 TYPE_MIN_VALUE (TYPE_DOMAIN (TREE_TYPE (val)))));
3843 i = size_binop (PLUS_EXPR, i, convert (sizetype, integer_one_node));
3844
3845 /* Multiply by the array element unit size to find number of bytes. */
3846 i = size_binop (MULT_EXPR, i, TYPE_SIZE_UNIT (TREE_TYPE (TREE_TYPE (val))));
3847
3848 return tree_low_cst (i, 1);
3849 }
3850
3851 /* Subroutine of output_constant, used for CONSTRUCTORs (aggregate constants).
3852 Generate at least SIZE bytes, padding if necessary. */
3853
3854 static void
3855 output_constructor (tree exp, unsigned HOST_WIDE_INT size,
3856 unsigned int align)
3857 {
3858 tree type = TREE_TYPE (exp);
3859 tree link, field = 0;
3860 tree min_index = 0;
3861 /* Number of bytes output or skipped so far.
3862 In other words, current position within the constructor. */
3863 HOST_WIDE_INT total_bytes = 0;
3864 /* Nonzero means BYTE contains part of a byte, to be output. */
3865 int byte_buffer_in_use = 0;
3866 int byte = 0;
3867
3868 if (HOST_BITS_PER_WIDE_INT < BITS_PER_UNIT)
3869 abort ();
3870
3871 if (TREE_CODE (type) == RECORD_TYPE)
3872 field = TYPE_FIELDS (type);
3873
3874 if (TREE_CODE (type) == ARRAY_TYPE
3875 && TYPE_DOMAIN (type) != 0)
3876 min_index = TYPE_MIN_VALUE (TYPE_DOMAIN (type));
3877
3878 /* As LINK goes through the elements of the constant,
3879 FIELD goes through the structure fields, if the constant is a structure.
3880 if the constant is a union, then we override this,
3881 by getting the field from the TREE_LIST element.
3882 But the constant could also be an array. Then FIELD is zero.
3883
3884 There is always a maximum of one element in the chain LINK for unions
3885 (even if the initializer in a source program incorrectly contains
3886 more one). */
3887 for (link = CONSTRUCTOR_ELTS (exp);
3888 link;
3889 link = TREE_CHAIN (link),
3890 field = field ? TREE_CHAIN (field) : 0)
3891 {
3892 tree val = TREE_VALUE (link);
3893 tree index = 0;
3894
3895 /* The element in a union constructor specifies the proper field
3896 or index. */
3897 if ((TREE_CODE (type) == RECORD_TYPE || TREE_CODE (type) == UNION_TYPE
3898 || TREE_CODE (type) == QUAL_UNION_TYPE)
3899 && TREE_PURPOSE (link) != 0)
3900 field = TREE_PURPOSE (link);
3901
3902 else if (TREE_CODE (type) == ARRAY_TYPE)
3903 index = TREE_PURPOSE (link);
3904
3905 #ifdef ASM_COMMENT_START
3906 if (field && flag_verbose_asm)
3907 fprintf (asm_out_file, "%s %s:\n",
3908 ASM_COMMENT_START,
3909 DECL_NAME (field)
3910 ? IDENTIFIER_POINTER (DECL_NAME (field))
3911 : "<anonymous>");
3912 #endif
3913
3914 /* Eliminate the marker that makes a cast not be an lvalue. */
3915 if (val != 0)
3916 STRIP_NOPS (val);
3917
3918 if (index && TREE_CODE (index) == RANGE_EXPR)
3919 {
3920 unsigned HOST_WIDE_INT fieldsize
3921 = int_size_in_bytes (TREE_TYPE (type));
3922 HOST_WIDE_INT lo_index = tree_low_cst (TREE_OPERAND (index, 0), 0);
3923 HOST_WIDE_INT hi_index = tree_low_cst (TREE_OPERAND (index, 1), 0);
3924 HOST_WIDE_INT index;
3925 unsigned int align2 = min_align (align, fieldsize * BITS_PER_UNIT);
3926
3927 for (index = lo_index; index <= hi_index; index++)
3928 {
3929 /* Output the element's initial value. */
3930 if (val == 0)
3931 assemble_zeros (fieldsize);
3932 else
3933 output_constant (val, fieldsize, align2);
3934
3935 /* Count its size. */
3936 total_bytes += fieldsize;
3937 }
3938 }
3939 else if (field == 0 || !DECL_BIT_FIELD (field))
3940 {
3941 /* An element that is not a bit-field. */
3942
3943 unsigned HOST_WIDE_INT fieldsize;
3944 /* Since this structure is static,
3945 we know the positions are constant. */
3946 HOST_WIDE_INT pos = field ? int_byte_position (field) : 0;
3947 unsigned int align2;
3948
3949 if (index != 0)
3950 pos = (tree_low_cst (TYPE_SIZE_UNIT (TREE_TYPE (val)), 1)
3951 * (tree_low_cst (index, 0) - tree_low_cst (min_index, 0)));
3952
3953 /* Output any buffered-up bit-fields preceding this element. */
3954 if (byte_buffer_in_use)
3955 {
3956 assemble_integer (GEN_INT (byte), 1, BITS_PER_UNIT, 1);
3957 total_bytes++;
3958 byte_buffer_in_use = 0;
3959 }
3960
3961 /* Advance to offset of this element.
3962 Note no alignment needed in an array, since that is guaranteed
3963 if each element has the proper size. */
3964 if ((field != 0 || index != 0) && pos != total_bytes)
3965 {
3966 assemble_zeros (pos - total_bytes);
3967 total_bytes = pos;
3968 }
3969
3970 /* Find the alignment of this element. */
3971 align2 = min_align (align, BITS_PER_UNIT * pos);
3972
3973 /* Determine size this element should occupy. */
3974 if (field)
3975 {
3976 fieldsize = 0;
3977
3978 /* If this is an array with an unspecified upper bound,
3979 the initializer determines the size. */
3980 /* ??? This ought to only checked if DECL_SIZE_UNIT is NULL,
3981 but we cannot do this until the deprecated support for
3982 initializing zero-length array members is removed. */
3983 if (TREE_CODE (TREE_TYPE (field)) == ARRAY_TYPE
3984 && TYPE_DOMAIN (TREE_TYPE (field))
3985 && ! TYPE_MAX_VALUE (TYPE_DOMAIN (TREE_TYPE (field))))
3986 {
3987 fieldsize = array_size_for_constructor (val);
3988 /* Given a non-empty initialization, this field had
3989 better be last. */
3990 if (fieldsize != 0 && TREE_CHAIN (field) != NULL_TREE)
3991 abort ();
3992 }
3993 else if (DECL_SIZE_UNIT (field))
3994 {
3995 /* ??? This can't be right. If the decl size overflows
3996 a host integer we will silently emit no data. */
3997 if (host_integerp (DECL_SIZE_UNIT (field), 1))
3998 fieldsize = tree_low_cst (DECL_SIZE_UNIT (field), 1);
3999 }
4000 }
4001 else
4002 fieldsize = int_size_in_bytes (TREE_TYPE (type));
4003
4004 /* Output the element's initial value. */
4005 if (val == 0)
4006 assemble_zeros (fieldsize);
4007 else
4008 output_constant (val, fieldsize, align2);
4009
4010 /* Count its size. */
4011 total_bytes += fieldsize;
4012 }
4013 else if (val != 0 && TREE_CODE (val) != INTEGER_CST)
4014 error ("invalid initial value for member `%s'",
4015 IDENTIFIER_POINTER (DECL_NAME (field)));
4016 else
4017 {
4018 /* Element that is a bit-field. */
4019
4020 HOST_WIDE_INT next_offset = int_bit_position (field);
4021 HOST_WIDE_INT end_offset
4022 = (next_offset + tree_low_cst (DECL_SIZE (field), 1));
4023
4024 if (val == 0)
4025 val = integer_zero_node;
4026
4027 /* If this field does not start in this (or, next) byte,
4028 skip some bytes. */
4029 if (next_offset / BITS_PER_UNIT != total_bytes)
4030 {
4031 /* Output remnant of any bit field in previous bytes. */
4032 if (byte_buffer_in_use)
4033 {
4034 assemble_integer (GEN_INT (byte), 1, BITS_PER_UNIT, 1);
4035 total_bytes++;
4036 byte_buffer_in_use = 0;
4037 }
4038
4039 /* If still not at proper byte, advance to there. */
4040 if (next_offset / BITS_PER_UNIT != total_bytes)
4041 {
4042 assemble_zeros (next_offset / BITS_PER_UNIT - total_bytes);
4043 total_bytes = next_offset / BITS_PER_UNIT;
4044 }
4045 }
4046
4047 if (! byte_buffer_in_use)
4048 byte = 0;
4049
4050 /* We must split the element into pieces that fall within
4051 separate bytes, and combine each byte with previous or
4052 following bit-fields. */
4053
4054 /* next_offset is the offset n fbits from the beginning of
4055 the structure to the next bit of this element to be processed.
4056 end_offset is the offset of the first bit past the end of
4057 this element. */
4058 while (next_offset < end_offset)
4059 {
4060 int this_time;
4061 int shift;
4062 HOST_WIDE_INT value;
4063 HOST_WIDE_INT next_byte = next_offset / BITS_PER_UNIT;
4064 HOST_WIDE_INT next_bit = next_offset % BITS_PER_UNIT;
4065
4066 /* Advance from byte to byte
4067 within this element when necessary. */
4068 while (next_byte != total_bytes)
4069 {
4070 assemble_integer (GEN_INT (byte), 1, BITS_PER_UNIT, 1);
4071 total_bytes++;
4072 byte = 0;
4073 }
4074
4075 /* Number of bits we can process at once
4076 (all part of the same byte). */
4077 this_time = MIN (end_offset - next_offset,
4078 BITS_PER_UNIT - next_bit);
4079 if (BYTES_BIG_ENDIAN)
4080 {
4081 /* On big-endian machine, take the most significant bits
4082 first (of the bits that are significant)
4083 and put them into bytes from the most significant end. */
4084 shift = end_offset - next_offset - this_time;
4085
4086 /* Don't try to take a bunch of bits that cross
4087 the word boundary in the INTEGER_CST. We can
4088 only select bits from the LOW or HIGH part
4089 not from both. */
4090 if (shift < HOST_BITS_PER_WIDE_INT
4091 && shift + this_time > HOST_BITS_PER_WIDE_INT)
4092 {
4093 this_time = shift + this_time - HOST_BITS_PER_WIDE_INT;
4094 shift = HOST_BITS_PER_WIDE_INT;
4095 }
4096
4097 /* Now get the bits from the appropriate constant word. */
4098 if (shift < HOST_BITS_PER_WIDE_INT)
4099 value = TREE_INT_CST_LOW (val);
4100 else if (shift < 2 * HOST_BITS_PER_WIDE_INT)
4101 {
4102 value = TREE_INT_CST_HIGH (val);
4103 shift -= HOST_BITS_PER_WIDE_INT;
4104 }
4105 else
4106 abort ();
4107
4108 /* Get the result. This works only when:
4109 1 <= this_time <= HOST_BITS_PER_WIDE_INT. */
4110 byte |= (((value >> shift)
4111 & (((HOST_WIDE_INT) 2 << (this_time - 1)) - 1))
4112 << (BITS_PER_UNIT - this_time - next_bit));
4113 }
4114 else
4115 {
4116 /* On little-endian machines,
4117 take first the least significant bits of the value
4118 and pack them starting at the least significant
4119 bits of the bytes. */
4120 shift = next_offset - int_bit_position (field);
4121
4122 /* Don't try to take a bunch of bits that cross
4123 the word boundary in the INTEGER_CST. We can
4124 only select bits from the LOW or HIGH part
4125 not from both. */
4126 if (shift < HOST_BITS_PER_WIDE_INT
4127 && shift + this_time > HOST_BITS_PER_WIDE_INT)
4128 this_time = (HOST_BITS_PER_WIDE_INT - shift);
4129
4130 /* Now get the bits from the appropriate constant word. */
4131 if (shift < HOST_BITS_PER_WIDE_INT)
4132 value = TREE_INT_CST_LOW (val);
4133 else if (shift < 2 * HOST_BITS_PER_WIDE_INT)
4134 {
4135 value = TREE_INT_CST_HIGH (val);
4136 shift -= HOST_BITS_PER_WIDE_INT;
4137 }
4138 else
4139 abort ();
4140
4141 /* Get the result. This works only when:
4142 1 <= this_time <= HOST_BITS_PER_WIDE_INT. */
4143 byte |= (((value >> shift)
4144 & (((HOST_WIDE_INT) 2 << (this_time - 1)) - 1))
4145 << next_bit);
4146 }
4147
4148 next_offset += this_time;
4149 byte_buffer_in_use = 1;
4150 }
4151 }
4152 }
4153
4154 if (byte_buffer_in_use)
4155 {
4156 assemble_integer (GEN_INT (byte), 1, BITS_PER_UNIT, 1);
4157 total_bytes++;
4158 }
4159
4160 if ((unsigned HOST_WIDE_INT)total_bytes < size)
4161 assemble_zeros (size - total_bytes);
4162 }
4163
4164 /* This TREE_LIST contains any weak symbol declarations waiting
4165 to be emitted. */
4166 static GTY(()) tree weak_decls;
4167
4168 /* Mark DECL as weak. */
4169
4170 static void
4171 mark_weak (tree decl)
4172 {
4173 DECL_WEAK (decl) = 1;
4174
4175 if (DECL_RTL_SET_P (decl)
4176 && MEM_P (DECL_RTL (decl))
4177 && XEXP (DECL_RTL (decl), 0)
4178 && GET_CODE (XEXP (DECL_RTL (decl), 0)) == SYMBOL_REF)
4179 SYMBOL_REF_WEAK (XEXP (DECL_RTL (decl), 0)) = 1;
4180 }
4181
4182 /* Merge weak status between NEWDECL and OLDDECL. */
4183
4184 void
4185 merge_weak (tree newdecl, tree olddecl)
4186 {
4187 if (DECL_WEAK (newdecl) == DECL_WEAK (olddecl))
4188 return;
4189
4190 if (DECL_WEAK (newdecl))
4191 {
4192 tree wd;
4193
4194 /* NEWDECL is weak, but OLDDECL is not. */
4195
4196 /* If we already output the OLDDECL, we're in trouble; we can't
4197 go back and make it weak. This error cannot caught in
4198 declare_weak because the NEWDECL and OLDDECL was not yet
4199 been merged; therefore, TREE_ASM_WRITTEN was not set. */
4200 if (TREE_ASM_WRITTEN (olddecl))
4201 error ("%Jweak declaration of '%D' must precede definition",
4202 newdecl, newdecl);
4203
4204 /* If we've already generated rtl referencing OLDDECL, we may
4205 have done so in a way that will not function properly with
4206 a weak symbol. */
4207 else if (TREE_USED (olddecl)
4208 && TREE_SYMBOL_REFERENCED (DECL_ASSEMBLER_NAME (olddecl)))
4209 warning ("%Jweak declaration of '%D' after first use results "
4210 "in unspecified behavior", newdecl, newdecl);
4211
4212 if (SUPPORTS_WEAK)
4213 {
4214 /* We put the NEWDECL on the weak_decls list at some point.
4215 Replace it with the OLDDECL. */
4216 for (wd = weak_decls; wd; wd = TREE_CHAIN (wd))
4217 if (TREE_VALUE (wd) == newdecl)
4218 {
4219 TREE_VALUE (wd) = olddecl;
4220 break;
4221 }
4222 /* We may not find the entry on the list. If NEWDECL is a
4223 weak alias, then we will have already called
4224 globalize_decl to remove the entry; in that case, we do
4225 not need to do anything. */
4226 }
4227
4228 /* Make the OLDDECL weak; it's OLDDECL that we'll be keeping. */
4229 mark_weak (olddecl);
4230 }
4231 else
4232 /* OLDDECL was weak, but NEWDECL was not explicitly marked as
4233 weak. Just update NEWDECL to indicate that it's weak too. */
4234 mark_weak (newdecl);
4235 }
4236
4237 /* Declare DECL to be a weak symbol. */
4238
4239 void
4240 declare_weak (tree decl)
4241 {
4242 if (! TREE_PUBLIC (decl))
4243 error ("%Jweak declaration of '%D' must be public", decl, decl);
4244 else if (TREE_CODE (decl) == FUNCTION_DECL && TREE_ASM_WRITTEN (decl))
4245 error ("%Jweak declaration of '%D' must precede definition", decl, decl);
4246 else if (SUPPORTS_WEAK)
4247 {
4248 if (! DECL_WEAK (decl))
4249 weak_decls = tree_cons (NULL, decl, weak_decls);
4250 }
4251 else
4252 warning ("%Jweak declaration of '%D' not supported", decl, decl);
4253
4254 mark_weak (decl);
4255 }
4256
4257 /* Emit any pending weak declarations. */
4258
4259 void
4260 weak_finish (void)
4261 {
4262 tree t;
4263
4264 for (t = weak_decls; t; t = TREE_CHAIN (t))
4265 {
4266 tree decl = TREE_VALUE (t);
4267 #if defined (ASM_WEAKEN_DECL) || defined (ASM_WEAKEN_LABEL)
4268 const char *const name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
4269 #endif
4270
4271 if (! TREE_USED (decl))
4272 continue;
4273
4274 #ifdef ASM_WEAKEN_DECL
4275 ASM_WEAKEN_DECL (asm_out_file, decl, name, NULL);
4276 #else
4277 #ifdef ASM_WEAKEN_LABEL
4278 ASM_WEAKEN_LABEL (asm_out_file, name);
4279 #else
4280 #ifdef ASM_OUTPUT_WEAK_ALIAS
4281 warning ("only weak aliases are supported in this configuration");
4282 return;
4283 #endif
4284 #endif
4285 #endif
4286 }
4287 }
4288
4289 /* Emit the assembly bits to indicate that DECL is globally visible. */
4290
4291 static void
4292 globalize_decl (tree decl)
4293 {
4294 const char *name = XSTR (XEXP (DECL_RTL (decl), 0), 0);
4295
4296 #if defined (ASM_WEAKEN_LABEL) || defined (ASM_WEAKEN_DECL)
4297 if (DECL_WEAK (decl))
4298 {
4299 tree *p, t;
4300
4301 #ifdef ASM_WEAKEN_DECL
4302 ASM_WEAKEN_DECL (asm_out_file, decl, name, 0);
4303 #else
4304 ASM_WEAKEN_LABEL (asm_out_file, name);
4305 #endif
4306
4307 /* Remove this function from the pending weak list so that
4308 we do not emit multiple .weak directives for it. */
4309 for (p = &weak_decls; (t = *p) ; )
4310 {
4311 if (DECL_ASSEMBLER_NAME (decl) == DECL_ASSEMBLER_NAME (TREE_VALUE (t)))
4312 *p = TREE_CHAIN (t);
4313 else
4314 p = &TREE_CHAIN (t);
4315 }
4316 return;
4317 }
4318 #elif defined(ASM_MAKE_LABEL_LINKONCE)
4319 if (DECL_ONE_ONLY (decl))
4320 ASM_MAKE_LABEL_LINKONCE (asm_out_file, name);
4321 #endif
4322
4323 targetm.asm_out.globalize_label (asm_out_file, name);
4324 }
4325
4326 /* Emit an assembler directive to make the symbol for DECL an alias to
4327 the symbol for TARGET. */
4328
4329 void
4330 assemble_alias (tree decl, tree target ATTRIBUTE_UNUSED)
4331 {
4332 const char *name;
4333
4334 /* We must force creation of DECL_RTL for debug info generation, even though
4335 we don't use it here. */
4336 make_decl_rtl (decl);
4337
4338 name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
4339
4340 #ifdef ASM_OUTPUT_DEF
4341 /* Make name accessible from other files, if appropriate. */
4342
4343 if (TREE_PUBLIC (decl))
4344 {
4345 globalize_decl (decl);
4346 maybe_assemble_visibility (decl);
4347 }
4348
4349 #ifdef ASM_OUTPUT_DEF_FROM_DECLS
4350 ASM_OUTPUT_DEF_FROM_DECLS (asm_out_file, decl, target);
4351 #else
4352 ASM_OUTPUT_DEF (asm_out_file, name, IDENTIFIER_POINTER (target));
4353 #endif
4354 #else /* !ASM_OUTPUT_DEF */
4355 #if defined (ASM_OUTPUT_WEAK_ALIAS) || defined (ASM_WEAKEN_DECL)
4356 if (DECL_WEAK (decl))
4357 {
4358 tree *p, t;
4359 #ifdef ASM_WEAKEN_DECL
4360 ASM_WEAKEN_DECL (asm_out_file, decl, name, IDENTIFIER_POINTER (target));
4361 #else
4362 ASM_OUTPUT_WEAK_ALIAS (asm_out_file, name, IDENTIFIER_POINTER (target));
4363 #endif
4364 /* Remove this function from the pending weak list so that
4365 we do not emit multiple .weak directives for it. */
4366 for (p = &weak_decls; (t = *p) ; )
4367 if (DECL_ASSEMBLER_NAME (decl)
4368 == DECL_ASSEMBLER_NAME (TREE_VALUE (t)))
4369 *p = TREE_CHAIN (t);
4370 else
4371 p = &TREE_CHAIN (t);
4372 }
4373 else
4374 warning ("only weak aliases are supported in this configuration");
4375
4376 #else
4377 warning ("alias definitions not supported in this configuration; ignored");
4378 #endif
4379 #endif
4380
4381 TREE_USED (decl) = 1;
4382 TREE_ASM_WRITTEN (decl) = 1;
4383 TREE_ASM_WRITTEN (DECL_ASSEMBLER_NAME (decl)) = 1;
4384 }
4385
4386 /* Emit an assembler directive to set symbol for DECL visibility to
4387 the visibility type VIS, which must not be VISIBILITY_DEFAULT. */
4388
4389 void
4390 default_assemble_visibility (tree decl, int vis)
4391 {
4392 static const char * const visibility_types[] = {
4393 NULL, "internal", "hidden", "protected"
4394 };
4395
4396 const char *name, *type;
4397
4398 name = (IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl)));
4399 type = visibility_types[vis];
4400
4401 #ifdef HAVE_GAS_HIDDEN
4402 fprintf (asm_out_file, "\t.%s\t", type);
4403 assemble_name (asm_out_file, name);
4404 fprintf (asm_out_file, "\n");
4405 #else
4406 warning ("visibility attribute not supported in this configuration; ignored");
4407 #endif
4408 }
4409
4410 /* A helper function to call assemble_visibility when needed for a decl. */
4411
4412 static void
4413 maybe_assemble_visibility (tree decl)
4414 {
4415 enum symbol_visibility vis = DECL_VISIBILITY (decl);
4416
4417 if (vis != VISIBILITY_DEFAULT)
4418 targetm.asm_out.visibility (decl, vis);
4419 }
4420
4421 /* Returns 1 if the target configuration supports defining public symbols
4422 so that one of them will be chosen at link time instead of generating a
4423 multiply-defined symbol error, whether through the use of weak symbols or
4424 a target-specific mechanism for having duplicates discarded. */
4425
4426 int
4427 supports_one_only (void)
4428 {
4429 if (SUPPORTS_ONE_ONLY)
4430 return 1;
4431 return SUPPORTS_WEAK;
4432 }
4433
4434 /* Set up DECL as a public symbol that can be defined in multiple
4435 translation units without generating a linker error. */
4436
4437 void
4438 make_decl_one_only (tree decl)
4439 {
4440 if (TREE_CODE (decl) != VAR_DECL && TREE_CODE (decl) != FUNCTION_DECL)
4441 abort ();
4442
4443 TREE_PUBLIC (decl) = 1;
4444
4445 if (SUPPORTS_ONE_ONLY)
4446 {
4447 #ifdef MAKE_DECL_ONE_ONLY
4448 MAKE_DECL_ONE_ONLY (decl);
4449 #endif
4450 DECL_ONE_ONLY (decl) = 1;
4451 }
4452 else if (TREE_CODE (decl) == VAR_DECL
4453 && (DECL_INITIAL (decl) == 0 || DECL_INITIAL (decl) == error_mark_node))
4454 DECL_COMMON (decl) = 1;
4455 else if (SUPPORTS_WEAK)
4456 DECL_WEAK (decl) = 1;
4457 else
4458 abort ();
4459 }
4460
4461 void
4462 init_varasm_once (void)
4463 {
4464 in_named_htab = htab_create_ggc (31, in_named_entry_hash,
4465 in_named_entry_eq, NULL);
4466 const_desc_htab = htab_create_ggc (1009, const_desc_hash,
4467 const_desc_eq, NULL);
4468
4469 const_alias_set = new_alias_set ();
4470 }
4471
4472 enum tls_model
4473 decl_tls_model (tree decl)
4474 {
4475 enum tls_model kind;
4476 tree attr = lookup_attribute ("tls_model", DECL_ATTRIBUTES (decl));
4477 bool is_local;
4478
4479 if (attr)
4480 {
4481 attr = TREE_VALUE (TREE_VALUE (attr));
4482 if (TREE_CODE (attr) != STRING_CST)
4483 abort ();
4484 if (!strcmp (TREE_STRING_POINTER (attr), "local-exec"))
4485 kind = TLS_MODEL_LOCAL_EXEC;
4486 else if (!strcmp (TREE_STRING_POINTER (attr), "initial-exec"))
4487 kind = TLS_MODEL_INITIAL_EXEC;
4488 else if (!strcmp (TREE_STRING_POINTER (attr), "local-dynamic"))
4489 kind = optimize ? TLS_MODEL_LOCAL_DYNAMIC : TLS_MODEL_GLOBAL_DYNAMIC;
4490 else if (!strcmp (TREE_STRING_POINTER (attr), "global-dynamic"))
4491 kind = TLS_MODEL_GLOBAL_DYNAMIC;
4492 else
4493 abort ();
4494 return kind;
4495 }
4496
4497 is_local = targetm.binds_local_p (decl);
4498 if (!flag_pic)
4499 {
4500 if (is_local)
4501 kind = TLS_MODEL_LOCAL_EXEC;
4502 else
4503 kind = TLS_MODEL_INITIAL_EXEC;
4504 }
4505 /* Local dynamic is inefficient when we're not combining the
4506 parts of the address. */
4507 else if (optimize && is_local)
4508 kind = TLS_MODEL_LOCAL_DYNAMIC;
4509 else
4510 kind = TLS_MODEL_GLOBAL_DYNAMIC;
4511 if (kind < flag_tls_default)
4512 kind = flag_tls_default;
4513
4514 return kind;
4515 }
4516
4517 /* Select a set of attributes for section NAME based on the properties
4518 of DECL and whether or not RELOC indicates that DECL's initializer
4519 might contain runtime relocations.
4520
4521 We make the section read-only and executable for a function decl,
4522 read-only for a const data decl, and writable for a non-const data decl. */
4523
4524 unsigned int
4525 default_section_type_flags (tree decl, const char *name, int reloc)
4526 {
4527 return default_section_type_flags_1 (decl, name, reloc, flag_pic);
4528 }
4529
4530 unsigned int
4531 default_section_type_flags_1 (tree decl, const char *name, int reloc,
4532 int shlib)
4533 {
4534 unsigned int flags;
4535
4536 if (decl && TREE_CODE (decl) == FUNCTION_DECL)
4537 flags = SECTION_CODE;
4538 else if (decl && decl_readonly_section_1 (decl, reloc, shlib))
4539 flags = 0;
4540 else if (unlikely_text_section_name
4541 && strcmp (name, unlikely_text_section_name) == 0)
4542 flags = SECTION_CODE;
4543 else
4544 flags = SECTION_WRITE;
4545
4546 if (decl && DECL_ONE_ONLY (decl))
4547 flags |= SECTION_LINKONCE;
4548
4549 if (decl && TREE_CODE (decl) == VAR_DECL && DECL_THREAD_LOCAL (decl))
4550 flags |= SECTION_TLS | SECTION_WRITE;
4551
4552 if (strcmp (name, ".bss") == 0
4553 || strncmp (name, ".bss.", 5) == 0
4554 || strncmp (name, ".gnu.linkonce.b.", 16) == 0
4555 || strcmp (name, ".sbss") == 0
4556 || strncmp (name, ".sbss.", 6) == 0
4557 || strncmp (name, ".gnu.linkonce.sb.", 17) == 0
4558 || strcmp (name, ".tbss") == 0
4559 || strncmp (name, ".gnu.linkonce.tb.", 17) == 0)
4560 flags |= SECTION_BSS;
4561
4562 if (strcmp (name, ".tdata") == 0
4563 || strcmp (name, ".tbss") == 0
4564 || strncmp (name, ".gnu.linkonce.td.", 17) == 0
4565 || strncmp (name, ".gnu.linkonce.tb.", 17) == 0)
4566 flags |= SECTION_TLS;
4567
4568 /* These three sections have special ELF types. They are neither
4569 SHT_PROGBITS nor SHT_NOBITS, so when changing sections we don't
4570 want to print a section type (@progbits or @nobits). If someone
4571 is silly enough to emit code or TLS variables to one of these
4572 sections, then don't handle them specially. */
4573 if (!(flags & (SECTION_CODE | SECTION_BSS | SECTION_TLS))
4574 && (strcmp (name, ".init_array") == 0
4575 || strcmp (name, ".fini_array") == 0
4576 || strcmp (name, ".preinit_array") == 0))
4577 flags |= SECTION_NOTYPE;
4578
4579 return flags;
4580 }
4581
4582 /* Output assembly to switch to section NAME with attribute FLAGS.
4583 Four variants for common object file formats. */
4584
4585 void
4586 default_no_named_section (const char *name ATTRIBUTE_UNUSED,
4587 unsigned int flags ATTRIBUTE_UNUSED,
4588 tree decl ATTRIBUTE_UNUSED)
4589 {
4590 /* Some object formats don't support named sections at all. The
4591 front-end should already have flagged this as an error. */
4592 abort ();
4593 }
4594
4595 void
4596 default_elf_asm_named_section (const char *name, unsigned int flags,
4597 tree decl ATTRIBUTE_UNUSED)
4598 {
4599 char flagchars[10], *f = flagchars;
4600
4601 /* If we have already declared this section, we can use an
4602 abbreviated form to switch back to it -- unless this section is
4603 part of a COMDAT groups, in which case GAS requires the full
4604 declaration every time. */
4605 if (!(HAVE_GAS_COMDAT_GROUP && (flags & SECTION_LINKONCE))
4606 && ! named_section_first_declaration (name))
4607 {
4608 fprintf (asm_out_file, "\t.section\t%s\n", name);
4609 return;
4610 }
4611
4612 if (!(flags & SECTION_DEBUG))
4613 *f++ = 'a';
4614 if (flags & SECTION_WRITE)
4615 *f++ = 'w';
4616 if (flags & SECTION_CODE)
4617 *f++ = 'x';
4618 if (flags & SECTION_SMALL)
4619 *f++ = 's';
4620 if (flags & SECTION_MERGE)
4621 *f++ = 'M';
4622 if (flags & SECTION_STRINGS)
4623 *f++ = 'S';
4624 if (flags & SECTION_TLS)
4625 *f++ = 'T';
4626 if (HAVE_GAS_COMDAT_GROUP && (flags & SECTION_LINKONCE))
4627 *f++ = 'G';
4628 *f = '\0';
4629
4630 fprintf (asm_out_file, "\t.section\t%s,\"%s\"", name, flagchars);
4631
4632 if (!(flags & SECTION_NOTYPE))
4633 {
4634 const char *type;
4635 const char *format;
4636
4637 if (flags & SECTION_BSS)
4638 type = "nobits";
4639 else
4640 type = "progbits";
4641
4642 format = ",@%s";
4643 #ifdef ASM_COMMENT_START
4644 /* On platforms that use "@" as the assembly comment character,
4645 use "%" instead. */
4646 if (strcmp (ASM_COMMENT_START, "@") == 0)
4647 format = ",%%%s";
4648 #endif
4649 fprintf (asm_out_file, format, type);
4650
4651 if (flags & SECTION_ENTSIZE)
4652 fprintf (asm_out_file, ",%d", flags & SECTION_ENTSIZE);
4653 if (HAVE_GAS_COMDAT_GROUP && (flags & SECTION_LINKONCE))
4654 fprintf (asm_out_file, ",%s,comdat",
4655 lang_hooks.decls.comdat_group (decl));
4656 }
4657
4658 putc ('\n', asm_out_file);
4659 }
4660
4661 void
4662 default_coff_asm_named_section (const char *name, unsigned int flags,
4663 tree decl ATTRIBUTE_UNUSED)
4664 {
4665 char flagchars[8], *f = flagchars;
4666
4667 if (flags & SECTION_WRITE)
4668 *f++ = 'w';
4669 if (flags & SECTION_CODE)
4670 *f++ = 'x';
4671 *f = '\0';
4672
4673 fprintf (asm_out_file, "\t.section\t%s,\"%s\"\n", name, flagchars);
4674 }
4675
4676 void
4677 default_pe_asm_named_section (const char *name, unsigned int flags,
4678 tree decl)
4679 {
4680 default_coff_asm_named_section (name, flags, decl);
4681
4682 if (flags & SECTION_LINKONCE)
4683 {
4684 /* Functions may have been compiled at various levels of
4685 optimization so we can't use `same_size' here.
4686 Instead, have the linker pick one. */
4687 fprintf (asm_out_file, "\t.linkonce %s\n",
4688 (flags & SECTION_CODE ? "discard" : "same_size"));
4689 }
4690 }
4691 \f
4692 /* The lame default section selector. */
4693
4694 void
4695 default_select_section (tree decl, int reloc,
4696 unsigned HOST_WIDE_INT align ATTRIBUTE_UNUSED)
4697 {
4698 bool readonly = false;
4699
4700 if (DECL_P (decl))
4701 {
4702 if (decl_readonly_section (decl, reloc))
4703 readonly = true;
4704 }
4705 else if (TREE_CODE (decl) == CONSTRUCTOR)
4706 {
4707 if (! ((flag_pic && reloc)
4708 || !TREE_READONLY (decl)
4709 || TREE_SIDE_EFFECTS (decl)
4710 || !TREE_CONSTANT (decl)))
4711 readonly = true;
4712 }
4713 else if (TREE_CODE (decl) == STRING_CST)
4714 readonly = true;
4715 else if (! (flag_pic && reloc))
4716 readonly = true;
4717
4718 if (readonly)
4719 readonly_data_section ();
4720 else
4721 data_section ();
4722 }
4723
4724 /* A helper function for default_elf_select_section and
4725 default_elf_unique_section. Categorizes the DECL. */
4726
4727 enum section_category
4728 {
4729 SECCAT_TEXT,
4730
4731 SECCAT_RODATA,
4732 SECCAT_RODATA_MERGE_STR,
4733 SECCAT_RODATA_MERGE_STR_INIT,
4734 SECCAT_RODATA_MERGE_CONST,
4735 SECCAT_SRODATA,
4736
4737 SECCAT_DATA,
4738
4739 /* To optimize loading of shared programs, define following subsections
4740 of data section:
4741 _REL Contains data that has relocations, so they get grouped
4742 together and dynamic linker will visit fewer pages in memory.
4743 _RO Contains data that is otherwise read-only. This is useful
4744 with prelinking as most relocations won't be dynamically
4745 linked and thus stay read only.
4746 _LOCAL Marks data containing relocations only to local objects.
4747 These relocations will get fully resolved by prelinking. */
4748 SECCAT_DATA_REL,
4749 SECCAT_DATA_REL_LOCAL,
4750 SECCAT_DATA_REL_RO,
4751 SECCAT_DATA_REL_RO_LOCAL,
4752
4753 SECCAT_SDATA,
4754 SECCAT_TDATA,
4755
4756 SECCAT_BSS,
4757 SECCAT_SBSS,
4758 SECCAT_TBSS
4759 };
4760
4761 static enum section_category
4762 categorize_decl_for_section (tree, int, int);
4763
4764 static enum section_category
4765 categorize_decl_for_section (tree decl, int reloc, int shlib)
4766 {
4767 enum section_category ret;
4768
4769 if (TREE_CODE (decl) == FUNCTION_DECL)
4770 return SECCAT_TEXT;
4771 else if (TREE_CODE (decl) == STRING_CST)
4772 {
4773 if (flag_mudflap) /* or !flag_merge_constants */
4774 return SECCAT_RODATA;
4775 else
4776 return SECCAT_RODATA_MERGE_STR;
4777 }
4778 else if (TREE_CODE (decl) == VAR_DECL)
4779 {
4780 if (DECL_INITIAL (decl) == NULL
4781 || DECL_INITIAL (decl) == error_mark_node
4782 || (flag_zero_initialized_in_bss
4783 /* Leave constant zeroes in .rodata so they can be shared. */
4784 && !TREE_READONLY (decl)
4785 && initializer_zerop (DECL_INITIAL (decl))))
4786 ret = SECCAT_BSS;
4787 else if (! TREE_READONLY (decl)
4788 || TREE_SIDE_EFFECTS (decl)
4789 || ! TREE_CONSTANT (DECL_INITIAL (decl)))
4790 {
4791 if (shlib && (reloc & 2))
4792 ret = SECCAT_DATA_REL;
4793 else if (shlib && reloc)
4794 ret = SECCAT_DATA_REL_LOCAL;
4795 else
4796 ret = SECCAT_DATA;
4797 }
4798 else if (shlib && (reloc & 2))
4799 ret = SECCAT_DATA_REL_RO;
4800 else if (shlib && reloc)
4801 ret = SECCAT_DATA_REL_RO_LOCAL;
4802 else if (reloc || flag_merge_constants < 2)
4803 /* C and C++ don't allow different variables to share the same
4804 location. -fmerge-all-constants allows even that (at the
4805 expense of not conforming). */
4806 ret = SECCAT_RODATA;
4807 else if (TREE_CODE (DECL_INITIAL (decl)) == STRING_CST)
4808 ret = SECCAT_RODATA_MERGE_STR_INIT;
4809 else
4810 ret = SECCAT_RODATA_MERGE_CONST;
4811 }
4812 else if (TREE_CODE (decl) == CONSTRUCTOR)
4813 {
4814 if ((shlib && reloc)
4815 || TREE_SIDE_EFFECTS (decl)
4816 || ! TREE_CONSTANT (decl))
4817 ret = SECCAT_DATA;
4818 else
4819 ret = SECCAT_RODATA;
4820 }
4821 else
4822 ret = SECCAT_RODATA;
4823
4824 /* There are no read-only thread-local sections. */
4825 if (TREE_CODE (decl) == VAR_DECL && DECL_THREAD_LOCAL (decl))
4826 {
4827 /* Note that this would be *just* SECCAT_BSS, except that there's
4828 no concept of a read-only thread-local-data section. */
4829 if (ret == SECCAT_BSS
4830 || (flag_zero_initialized_in_bss
4831 && initializer_zerop (DECL_INITIAL (decl))))
4832 ret = SECCAT_TBSS;
4833 else
4834 ret = SECCAT_TDATA;
4835 }
4836
4837 /* If the target uses small data sections, select it. */
4838 else if (targetm.in_small_data_p (decl))
4839 {
4840 if (ret == SECCAT_BSS)
4841 ret = SECCAT_SBSS;
4842 else if (targetm.have_srodata_section && ret == SECCAT_RODATA)
4843 ret = SECCAT_SRODATA;
4844 else
4845 ret = SECCAT_SDATA;
4846 }
4847
4848 return ret;
4849 }
4850
4851 bool
4852 decl_readonly_section (tree decl, int reloc)
4853 {
4854 return decl_readonly_section_1 (decl, reloc, flag_pic);
4855 }
4856
4857 bool
4858 decl_readonly_section_1 (tree decl, int reloc, int shlib)
4859 {
4860 switch (categorize_decl_for_section (decl, reloc, shlib))
4861 {
4862 case SECCAT_RODATA:
4863 case SECCAT_RODATA_MERGE_STR:
4864 case SECCAT_RODATA_MERGE_STR_INIT:
4865 case SECCAT_RODATA_MERGE_CONST:
4866 case SECCAT_SRODATA:
4867 return true;
4868 break;
4869 default:
4870 return false;
4871 break;
4872 }
4873 }
4874
4875 /* Select a section based on the above categorization. */
4876
4877 void
4878 default_elf_select_section (tree decl, int reloc,
4879 unsigned HOST_WIDE_INT align)
4880 {
4881 default_elf_select_section_1 (decl, reloc, align, flag_pic);
4882 }
4883
4884 void
4885 default_elf_select_section_1 (tree decl, int reloc,
4886 unsigned HOST_WIDE_INT align, int shlib)
4887 {
4888 switch (categorize_decl_for_section (decl, reloc, shlib))
4889 {
4890 case SECCAT_TEXT:
4891 /* We're not supposed to be called on FUNCTION_DECLs. */
4892 abort ();
4893 case SECCAT_RODATA:
4894 readonly_data_section ();
4895 break;
4896 case SECCAT_RODATA_MERGE_STR:
4897 mergeable_string_section (decl, align, 0);
4898 break;
4899 case SECCAT_RODATA_MERGE_STR_INIT:
4900 mergeable_string_section (DECL_INITIAL (decl), align, 0);
4901 break;
4902 case SECCAT_RODATA_MERGE_CONST:
4903 mergeable_constant_section (DECL_MODE (decl), align, 0);
4904 break;
4905 case SECCAT_SRODATA:
4906 named_section (NULL_TREE, ".sdata2", reloc);
4907 break;
4908 case SECCAT_DATA:
4909 data_section ();
4910 break;
4911 case SECCAT_DATA_REL:
4912 named_section (NULL_TREE, ".data.rel", reloc);
4913 break;
4914 case SECCAT_DATA_REL_LOCAL:
4915 named_section (NULL_TREE, ".data.rel.local", reloc);
4916 break;
4917 case SECCAT_DATA_REL_RO:
4918 named_section (NULL_TREE, ".data.rel.ro", reloc);
4919 break;
4920 case SECCAT_DATA_REL_RO_LOCAL:
4921 named_section (NULL_TREE, ".data.rel.ro.local", reloc);
4922 break;
4923 case SECCAT_SDATA:
4924 named_section (NULL_TREE, ".sdata", reloc);
4925 break;
4926 case SECCAT_TDATA:
4927 named_section (NULL_TREE, ".tdata", reloc);
4928 break;
4929 case SECCAT_BSS:
4930 #ifdef BSS_SECTION_ASM_OP
4931 bss_section ();
4932 #else
4933 named_section (NULL_TREE, ".bss", reloc);
4934 #endif
4935 break;
4936 case SECCAT_SBSS:
4937 named_section (NULL_TREE, ".sbss", reloc);
4938 break;
4939 case SECCAT_TBSS:
4940 named_section (NULL_TREE, ".tbss", reloc);
4941 break;
4942 default:
4943 abort ();
4944 }
4945 }
4946
4947 /* Construct a unique section name based on the decl name and the
4948 categorization performed above. */
4949
4950 void
4951 default_unique_section (tree decl, int reloc)
4952 {
4953 default_unique_section_1 (decl, reloc, flag_pic);
4954 }
4955
4956 void
4957 default_unique_section_1 (tree decl, int reloc, int shlib)
4958 {
4959 bool one_only = DECL_ONE_ONLY (decl);
4960 const char *prefix, *name;
4961 size_t nlen, plen;
4962 char *string;
4963
4964 switch (categorize_decl_for_section (decl, reloc, shlib))
4965 {
4966 case SECCAT_TEXT:
4967 prefix = one_only ? ".gnu.linkonce.t." : ".text.";
4968 break;
4969 case SECCAT_RODATA:
4970 case SECCAT_RODATA_MERGE_STR:
4971 case SECCAT_RODATA_MERGE_STR_INIT:
4972 case SECCAT_RODATA_MERGE_CONST:
4973 prefix = one_only ? ".gnu.linkonce.r." : ".rodata.";
4974 break;
4975 case SECCAT_SRODATA:
4976 prefix = one_only ? ".gnu.linkonce.s2." : ".sdata2.";
4977 break;
4978 case SECCAT_DATA:
4979 case SECCAT_DATA_REL:
4980 case SECCAT_DATA_REL_LOCAL:
4981 case SECCAT_DATA_REL_RO:
4982 case SECCAT_DATA_REL_RO_LOCAL:
4983 prefix = one_only ? ".gnu.linkonce.d." : ".data.";
4984 break;
4985 case SECCAT_SDATA:
4986 prefix = one_only ? ".gnu.linkonce.s." : ".sdata.";
4987 break;
4988 case SECCAT_BSS:
4989 prefix = one_only ? ".gnu.linkonce.b." : ".bss.";
4990 break;
4991 case SECCAT_SBSS:
4992 prefix = one_only ? ".gnu.linkonce.sb." : ".sbss.";
4993 break;
4994 case SECCAT_TDATA:
4995 prefix = one_only ? ".gnu.linkonce.td." : ".tdata.";
4996 break;
4997 case SECCAT_TBSS:
4998 prefix = one_only ? ".gnu.linkonce.tb." : ".tbss.";
4999 break;
5000 default:
5001 abort ();
5002 }
5003 plen = strlen (prefix);
5004
5005 name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
5006 name = targetm.strip_name_encoding (name);
5007 nlen = strlen (name);
5008
5009 string = alloca (nlen + plen + 1);
5010 memcpy (string, prefix, plen);
5011 memcpy (string + plen, name, nlen + 1);
5012
5013 DECL_SECTION_NAME (decl) = build_string (nlen + plen, string);
5014 }
5015
5016 void
5017 default_select_rtx_section (enum machine_mode mode ATTRIBUTE_UNUSED,
5018 rtx x,
5019 unsigned HOST_WIDE_INT align ATTRIBUTE_UNUSED)
5020 {
5021 if (flag_pic)
5022 switch (GET_CODE (x))
5023 {
5024 case CONST:
5025 case SYMBOL_REF:
5026 case LABEL_REF:
5027 data_section ();
5028 return;
5029
5030 default:
5031 break;
5032 }
5033
5034 readonly_data_section ();
5035 }
5036
5037 void
5038 default_elf_select_rtx_section (enum machine_mode mode, rtx x,
5039 unsigned HOST_WIDE_INT align)
5040 {
5041 /* ??? Handle small data here somehow. */
5042
5043 if (flag_pic)
5044 switch (GET_CODE (x))
5045 {
5046 case CONST:
5047 case SYMBOL_REF:
5048 named_section (NULL_TREE, ".data.rel.ro", 3);
5049 return;
5050
5051 case LABEL_REF:
5052 named_section (NULL_TREE, ".data.rel.ro.local", 1);
5053 return;
5054
5055 default:
5056 break;
5057 }
5058
5059 mergeable_constant_section (mode, align, 0);
5060 }
5061
5062 /* Set the generally applicable flags on the SYMBOL_REF for EXP. */
5063
5064 void
5065 default_encode_section_info (tree decl, rtx rtl, int first ATTRIBUTE_UNUSED)
5066 {
5067 rtx symbol;
5068 int flags;
5069
5070 /* Careful not to prod global register variables. */
5071 if (!MEM_P (rtl))
5072 return;
5073 symbol = XEXP (rtl, 0);
5074 if (GET_CODE (symbol) != SYMBOL_REF)
5075 return;
5076
5077 flags = 0;
5078 if (TREE_CODE (decl) == FUNCTION_DECL)
5079 flags |= SYMBOL_FLAG_FUNCTION;
5080 if (targetm.binds_local_p (decl))
5081 flags |= SYMBOL_FLAG_LOCAL;
5082 if (targetm.in_small_data_p (decl))
5083 flags |= SYMBOL_FLAG_SMALL;
5084 if (TREE_CODE (decl) == VAR_DECL && DECL_THREAD_LOCAL (decl))
5085 flags |= decl_tls_model (decl) << SYMBOL_FLAG_TLS_SHIFT;
5086 /* ??? Why is DECL_EXTERNAL ever set for non-PUBLIC names? Without
5087 being PUBLIC, the thing *must* be defined in this translation unit.
5088 Prevent this buglet from being propagated into rtl code as well. */
5089 if (DECL_P (decl) && DECL_EXTERNAL (decl) && TREE_PUBLIC (decl))
5090 flags |= SYMBOL_FLAG_EXTERNAL;
5091
5092 SYMBOL_REF_FLAGS (symbol) = flags;
5093 }
5094
5095 /* By default, we do nothing for encode_section_info, so we need not
5096 do anything but discard the '*' marker. */
5097
5098 const char *
5099 default_strip_name_encoding (const char *str)
5100 {
5101 return str + (*str == '*');
5102 }
5103
5104 /* Assume ELF-ish defaults, since that's pretty much the most liberal
5105 wrt cross-module name binding. */
5106
5107 bool
5108 default_binds_local_p (tree exp)
5109 {
5110 return default_binds_local_p_1 (exp, flag_shlib);
5111 }
5112
5113 bool
5114 default_binds_local_p_1 (tree exp, int shlib)
5115 {
5116 bool local_p;
5117
5118 /* A non-decl is an entry in the constant pool. */
5119 if (!DECL_P (exp))
5120 local_p = true;
5121 /* Static variables are always local. */
5122 else if (! TREE_PUBLIC (exp))
5123 local_p = true;
5124 /* A variable is local if the user explicitly tells us so. */
5125 else if (DECL_VISIBILITY_SPECIFIED (exp) && DECL_VISIBILITY (exp) != VISIBILITY_DEFAULT)
5126 local_p = true;
5127 /* Otherwise, variables defined outside this object may not be local. */
5128 else if (DECL_EXTERNAL (exp))
5129 local_p = false;
5130 /* Linkonce and weak data are never local. */
5131 else if (DECL_ONE_ONLY (exp) || DECL_WEAK (exp))
5132 local_p = false;
5133 /* If none of the above and visibility is not default, make local. */
5134 else if (DECL_VISIBILITY (exp) != VISIBILITY_DEFAULT)
5135 local_p = true;
5136 /* If PIC, then assume that any global name can be overridden by
5137 symbols resolved from other modules. */
5138 else if (shlib)
5139 local_p = false;
5140 /* Uninitialized COMMON variable may be unified with symbols
5141 resolved from other modules. */
5142 else if (DECL_COMMON (exp)
5143 && (DECL_INITIAL (exp) == NULL
5144 || DECL_INITIAL (exp) == error_mark_node))
5145 local_p = false;
5146 /* Otherwise we're left with initialized (or non-common) global data
5147 which is of necessity defined locally. */
5148 else
5149 local_p = true;
5150
5151 return local_p;
5152 }
5153
5154 /* Determine whether or not a pointer mode is valid. Assume defaults
5155 of ptr_mode or Pmode - can be overridden. */
5156 bool
5157 default_valid_pointer_mode (enum machine_mode mode)
5158 {
5159 return (mode == ptr_mode || mode == Pmode);
5160 }
5161
5162 /* Default function to output code that will globalize a label. A
5163 target must define GLOBAL_ASM_OP or provide it's own function to
5164 globalize a label. */
5165 #ifdef GLOBAL_ASM_OP
5166 void
5167 default_globalize_label (FILE * stream, const char *name)
5168 {
5169 fputs (GLOBAL_ASM_OP, stream);
5170 assemble_name (stream, name);
5171 putc ('\n', stream);
5172 }
5173 #endif /* GLOBAL_ASM_OP */
5174
5175 /* Default function to output a label for unwind information. The
5176 default is to do nothing. A target that needs nonlocal labels for
5177 unwind information must provide its own function to do this. */
5178 void
5179 default_emit_unwind_label (FILE * stream ATTRIBUTE_UNUSED,
5180 tree decl ATTRIBUTE_UNUSED,
5181 int for_eh ATTRIBUTE_UNUSED,
5182 int empty ATTRIBUTE_UNUSED)
5183 {
5184 }
5185
5186 /* This is how to output an internal numbered label where PREFIX is
5187 the class of label and LABELNO is the number within the class. */
5188
5189 void
5190 default_internal_label (FILE *stream, const char *prefix,
5191 unsigned long labelno)
5192 {
5193 char *const buf = alloca (40 + strlen (prefix));
5194 ASM_GENERATE_INTERNAL_LABEL (buf, prefix, labelno);
5195 ASM_OUTPUT_LABEL (stream, buf);
5196 }
5197
5198 /* This is the default behavior at the beginning of a file. It's
5199 controlled by two other target-hook toggles. */
5200 void
5201 default_file_start (void)
5202 {
5203 if (targetm.file_start_app_off && !flag_verbose_asm)
5204 fputs (ASM_APP_OFF, asm_out_file);
5205
5206 if (targetm.file_start_file_directive)
5207 output_file_directive (asm_out_file, main_input_filename);
5208 }
5209
5210 /* This is a generic routine suitable for use as TARGET_ASM_FILE_END
5211 which emits a special section directive used to indicate whether or
5212 not this object file needs an executable stack. This is primarily
5213 a GNU extension to ELF but could be used on other targets. */
5214
5215 int trampolines_created;
5216
5217 void
5218 file_end_indicate_exec_stack (void)
5219 {
5220 unsigned int flags = SECTION_DEBUG;
5221 if (trampolines_created)
5222 flags |= SECTION_CODE;
5223
5224 named_section_flags (".note.GNU-stack", flags);
5225 }
5226
5227 #include "gt-varasm.h"