fold-const.c (force_fit_type): Handle OFFSET_TYPE.
[gcc.git] / gcc / varasm.c
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 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 "cgraph.h"
52
53 #ifdef XCOFF_DEBUGGING_INFO
54 #include "xcoffout.h" /* Needed for external data
55 declarations for e.g. AIX 4.x. */
56 #endif
57
58 #ifndef TRAMPOLINE_ALIGNMENT
59 #define TRAMPOLINE_ALIGNMENT FUNCTION_BOUNDARY
60 #endif
61
62 #ifndef ASM_STABS_OP
63 #define ASM_STABS_OP "\t.stabs\t"
64 #endif
65
66 /* The (assembler) name of the first globally-visible object output. */
67 const char *first_global_object_name;
68 const char *weak_global_object_name;
69
70 struct addr_const;
71 struct constant_descriptor_rtx;
72 struct rtx_const;
73 struct pool_constant;
74
75 #define MAX_RTX_HASH_TABLE 61
76
77 struct varasm_status GTY(())
78 {
79 /* Hash facility for making memory-constants
80 from constant rtl-expressions. It is used on RISC machines
81 where immediate integer arguments and constant addresses are restricted
82 so that such constants must be stored in memory.
83
84 This pool of constants is reinitialized for each function
85 so each function gets its own constants-pool that comes right before
86 it. */
87 struct constant_descriptor_rtx ** GTY ((length ("MAX_RTX_HASH_TABLE")))
88 x_const_rtx_hash_table;
89 struct pool_constant ** GTY ((length ("MAX_RTX_HASH_TABLE")))
90 x_const_rtx_sym_hash_table;
91
92 /* Pointers to first and last constant in pool. */
93 struct pool_constant *x_first_pool;
94 struct pool_constant *x_last_pool;
95
96 /* Current offset in constant pool (does not include any machine-specific
97 header). */
98 HOST_WIDE_INT x_pool_offset;
99
100 /* Number of tree-constants deferred during the expansion of this
101 function. */
102 unsigned int deferred_constants;
103 };
104
105 #define const_rtx_hash_table (cfun->varasm->x_const_rtx_hash_table)
106 #define const_rtx_sym_hash_table (cfun->varasm->x_const_rtx_sym_hash_table)
107 #define first_pool (cfun->varasm->x_first_pool)
108 #define last_pool (cfun->varasm->x_last_pool)
109 #define pool_offset (cfun->varasm->x_pool_offset)
110 #define n_deferred_constants (cfun->varasm->deferred_constants)
111
112 /* Number for making the label on the next
113 constant that is stored in memory. */
114
115 static GTY(()) int const_labelno;
116
117 /* Carry information from ASM_DECLARE_OBJECT_NAME
118 to ASM_FINISH_DECLARE_OBJECT. */
119
120 int size_directive_output;
121
122 /* The last decl for which assemble_variable was called,
123 if it did ASM_DECLARE_OBJECT_NAME.
124 If the last call to assemble_variable didn't do that,
125 this holds 0. */
126
127 tree last_assemble_variable_decl;
128
129 /* RTX_UNCHANGING_P in a MEM can mean it is stored into, for initialization.
130 So giving constant the alias set for the type will allow such
131 initializations to appear to conflict with the load of the constant. We
132 avoid this by giving all constants an alias set for just constants.
133 Since there will be no stores to that alias set, nothing will ever
134 conflict with them. */
135
136 static HOST_WIDE_INT const_alias_set;
137
138 static const char *strip_reg_name (const char *);
139 static int contains_pointers_p (tree);
140 static void decode_addr_const (tree, struct addr_const *);
141 static hashval_t const_desc_hash (const void *);
142 static int const_desc_eq (const void *, const void *);
143 static hashval_t const_hash_1 (const tree);
144 static int compare_constant (const tree, const tree);
145 static tree copy_constant (tree);
146 static void output_constant_def_contents (rtx);
147 static void decode_rtx_const (enum machine_mode, rtx, struct rtx_const *);
148 static unsigned int const_hash_rtx (enum machine_mode, rtx);
149 static int compare_constant_rtx (enum machine_mode, rtx,
150 struct constant_descriptor_rtx *);
151 static struct constant_descriptor_rtx * record_constant_rtx
152 (enum machine_mode, rtx);
153 static struct pool_constant *find_pool_constant (struct function *, rtx);
154 static void mark_constant_pool (void);
155 static void mark_constants (rtx);
156 static int mark_constant (rtx *current_rtx, void *data);
157 static int output_addressed_constants (tree);
158 static unsigned HOST_WIDE_INT array_size_for_constructor (tree);
159 static unsigned min_align (unsigned, unsigned);
160 static void output_constructor (tree, unsigned HOST_WIDE_INT, unsigned int);
161 static void globalize_decl (tree);
162 static void maybe_assemble_visibility (tree);
163 static int in_named_entry_eq (const void *, const void *);
164 static hashval_t in_named_entry_hash (const void *);
165 #ifdef ASM_OUTPUT_BSS
166 static void asm_output_bss (FILE *, tree, const char *,
167 unsigned HOST_WIDE_INT, unsigned HOST_WIDE_INT);
168 #endif
169 #ifdef BSS_SECTION_ASM_OP
170 #ifdef ASM_OUTPUT_ALIGNED_BSS
171 static void asm_output_aligned_bss (FILE *, tree, const char *,
172 unsigned HOST_WIDE_INT, int)
173 ATTRIBUTE_UNUSED;
174 #endif
175 #endif /* BSS_SECTION_ASM_OP */
176 static bool asm_emit_uninitialised (tree, const char*,
177 unsigned HOST_WIDE_INT,
178 unsigned HOST_WIDE_INT);
179 static void mark_weak (tree);
180 \f
181 enum in_section { no_section, in_text, in_data, in_named
182 #ifdef BSS_SECTION_ASM_OP
183 , in_bss
184 #endif
185 #ifdef CTORS_SECTION_ASM_OP
186 , in_ctors
187 #endif
188 #ifdef DTORS_SECTION_ASM_OP
189 , in_dtors
190 #endif
191 #ifdef READONLY_DATA_SECTION_ASM_OP
192 , in_readonly_data
193 #endif
194 #ifdef EXTRA_SECTIONS
195 , EXTRA_SECTIONS
196 #endif
197 };
198 static GTY(()) enum in_section in_section = no_section;
199
200 /* Return a nonzero value if DECL has a section attribute. */
201 #ifndef IN_NAMED_SECTION
202 #define IN_NAMED_SECTION(DECL) \
203 ((TREE_CODE (DECL) == FUNCTION_DECL || TREE_CODE (DECL) == VAR_DECL) \
204 && DECL_SECTION_NAME (DECL) != NULL_TREE)
205 #endif
206
207 /* Text of section name when in_section == in_named. */
208 static GTY(()) const char *in_named_name;
209
210 /* Hash table of flags that have been used for a particular named section. */
211
212 struct in_named_entry GTY(())
213 {
214 const char *name;
215 unsigned int flags;
216 bool declared;
217 };
218
219 static GTY((param_is (struct in_named_entry))) htab_t in_named_htab;
220
221 /* Define functions like text_section for any extra sections. */
222 #ifdef EXTRA_SECTION_FUNCTIONS
223 EXTRA_SECTION_FUNCTIONS
224 #endif
225
226 /* Tell assembler to switch to text section. */
227
228 void
229 text_section (void)
230 {
231 if (in_section != in_text)
232 {
233 in_section = in_text;
234 #ifdef TEXT_SECTION
235 TEXT_SECTION ();
236 #else
237 fprintf (asm_out_file, "%s\n", TEXT_SECTION_ASM_OP);
238 #endif
239 }
240 }
241
242 /* Tell assembler to switch to data section. */
243
244 void
245 data_section (void)
246 {
247 if (in_section != in_data)
248 {
249 in_section = in_data;
250 if (flag_shared_data)
251 {
252 #ifdef SHARED_SECTION_ASM_OP
253 fprintf (asm_out_file, "%s\n", SHARED_SECTION_ASM_OP);
254 #else
255 fprintf (asm_out_file, "%s\n", DATA_SECTION_ASM_OP);
256 #endif
257 }
258 else
259 fprintf (asm_out_file, "%s\n", DATA_SECTION_ASM_OP);
260 }
261 }
262
263 /* Tell assembler to switch to read-only data section. This is normally
264 the text section. */
265
266 void
267 readonly_data_section (void)
268 {
269 #ifdef READONLY_DATA_SECTION
270 READONLY_DATA_SECTION (); /* Note this can call data_section. */
271 #else
272 #ifdef READONLY_DATA_SECTION_ASM_OP
273 if (in_section != in_readonly_data)
274 {
275 in_section = in_readonly_data;
276 fputs (READONLY_DATA_SECTION_ASM_OP, asm_out_file);
277 fputc ('\n', asm_out_file);
278 }
279 #else
280 text_section ();
281 #endif
282 #endif
283 }
284
285 /* Determine if we're in the text section. */
286
287 int
288 in_text_section (void)
289 {
290 return in_section == in_text;
291 }
292
293 /* Determine if we're in the data section. */
294
295 int
296 in_data_section (void)
297 {
298 return in_section == in_data;
299 }
300
301 /* Helper routines for maintaining in_named_htab. */
302
303 static int
304 in_named_entry_eq (const void *p1, const void *p2)
305 {
306 const struct in_named_entry *old = p1;
307 const char *new = p2;
308
309 return strcmp (old->name, new) == 0;
310 }
311
312 static hashval_t
313 in_named_entry_hash (const void *p)
314 {
315 const struct in_named_entry *old = p;
316 return htab_hash_string (old->name);
317 }
318
319 /* If SECTION has been seen before as a named section, return the flags
320 that were used. Otherwise, return 0. Note, that 0 is a perfectly valid
321 set of flags for a section to have, so 0 does not mean that the section
322 has not been seen. */
323
324 unsigned int
325 get_named_section_flags (const char *section)
326 {
327 struct in_named_entry **slot;
328
329 slot = (struct in_named_entry **)
330 htab_find_slot_with_hash (in_named_htab, section,
331 htab_hash_string (section), NO_INSERT);
332
333 return slot ? (*slot)->flags : 0;
334 }
335
336 /* Returns true if the section has been declared before. Sets internal
337 flag on this section in in_named_hash so subsequent calls on this
338 section will return false. */
339
340 bool
341 named_section_first_declaration (const char *name)
342 {
343 struct in_named_entry **slot;
344
345 slot = (struct in_named_entry **)
346 htab_find_slot_with_hash (in_named_htab, name,
347 htab_hash_string (name), NO_INSERT);
348 if (! (*slot)->declared)
349 {
350 (*slot)->declared = true;
351 return true;
352 }
353 else
354 {
355 return false;
356 }
357 }
358
359
360 /* Record FLAGS for SECTION. If SECTION was previously recorded with a
361 different set of flags, return false. */
362
363 bool
364 set_named_section_flags (const char *section, unsigned int flags)
365 {
366 struct in_named_entry **slot, *entry;
367
368 slot = (struct in_named_entry **)
369 htab_find_slot_with_hash (in_named_htab, section,
370 htab_hash_string (section), INSERT);
371 entry = *slot;
372
373 if (!entry)
374 {
375 entry = ggc_alloc (sizeof (*entry));
376 *slot = entry;
377 entry->name = ggc_strdup (section);
378 entry->flags = flags;
379 entry->declared = false;
380 }
381 else if (entry->flags != flags)
382 return false;
383
384 return true;
385 }
386
387 /* Tell assembler to change to section NAME with attributes FLAGS. */
388
389 void
390 named_section_flags (const char *name, unsigned int flags)
391 {
392 if (in_section != in_named || strcmp (name, in_named_name) != 0)
393 {
394 if (! set_named_section_flags (name, flags))
395 abort ();
396
397 (*targetm.asm_out.named_section) (name, flags);
398
399 if (flags & SECTION_FORGET)
400 in_section = no_section;
401 else
402 {
403 in_named_name = ggc_strdup (name);
404 in_section = in_named;
405 }
406 }
407 }
408
409 /* Tell assembler to change to section NAME for DECL.
410 If DECL is NULL, just switch to section NAME.
411 If NAME is NULL, get the name from DECL.
412 If RELOC is 1, the initializer for DECL contains relocs. */
413
414 void
415 named_section (tree decl, const char *name, int reloc)
416 {
417 unsigned int flags;
418
419 if (decl != NULL_TREE && !DECL_P (decl))
420 abort ();
421 if (name == NULL)
422 name = TREE_STRING_POINTER (DECL_SECTION_NAME (decl));
423
424 flags = (* targetm.section_type_flags) (decl, name, reloc);
425
426 /* Sanity check user variables for flag changes. Non-user
427 section flag changes will abort in named_section_flags.
428 However, don't complain if SECTION_OVERRIDE is set.
429 We trust that the setter knows that it is safe to ignore
430 the default flags for this decl. */
431 if (decl && ! set_named_section_flags (name, flags))
432 {
433 flags = get_named_section_flags (name);
434 if ((flags & SECTION_OVERRIDE) == 0)
435 error_with_decl (decl, "%s causes a section type conflict");
436 }
437
438 named_section_flags (name, flags);
439 }
440
441 /* If required, set DECL_SECTION_NAME to a unique name. */
442
443 void
444 resolve_unique_section (tree decl, int reloc ATTRIBUTE_UNUSED,
445 int flag_function_or_data_sections)
446 {
447 if (DECL_SECTION_NAME (decl) == NULL_TREE
448 && targetm.have_named_sections
449 && (flag_function_or_data_sections
450 || DECL_ONE_ONLY (decl)))
451 (*targetm.asm_out.unique_section) (decl, reloc);
452 }
453
454 #ifdef BSS_SECTION_ASM_OP
455
456 /* Tell the assembler to switch to the bss section. */
457
458 void
459 bss_section (void)
460 {
461 if (in_section != in_bss)
462 {
463 #ifdef SHARED_BSS_SECTION_ASM_OP
464 if (flag_shared_data)
465 fprintf (asm_out_file, "%s\n", SHARED_BSS_SECTION_ASM_OP);
466 else
467 #endif
468 fprintf (asm_out_file, "%s\n", BSS_SECTION_ASM_OP);
469
470 in_section = in_bss;
471 }
472 }
473
474 #ifdef ASM_OUTPUT_BSS
475
476 /* Utility function for ASM_OUTPUT_BSS for targets to use if
477 they don't support alignments in .bss.
478 ??? It is believed that this function will work in most cases so such
479 support is localized here. */
480
481 static void
482 asm_output_bss (FILE *file, tree decl ATTRIBUTE_UNUSED,
483 const char *name,
484 unsigned HOST_WIDE_INT size ATTRIBUTE_UNUSED,
485 unsigned HOST_WIDE_INT rounded)
486 {
487 (*targetm.asm_out.globalize_label) (file, name);
488 bss_section ();
489 #ifdef ASM_DECLARE_OBJECT_NAME
490 last_assemble_variable_decl = decl;
491 ASM_DECLARE_OBJECT_NAME (file, name, decl);
492 #else
493 /* Standard thing is just output label for the object. */
494 ASM_OUTPUT_LABEL (file, name);
495 #endif /* ASM_DECLARE_OBJECT_NAME */
496 ASM_OUTPUT_SKIP (file, rounded ? rounded : 1);
497 }
498
499 #endif
500
501 #ifdef ASM_OUTPUT_ALIGNED_BSS
502
503 /* Utility function for targets to use in implementing
504 ASM_OUTPUT_ALIGNED_BSS.
505 ??? It is believed that this function will work in most cases so such
506 support is localized here. */
507
508 static void
509 asm_output_aligned_bss (FILE *file, tree decl ATTRIBUTE_UNUSED,
510 const char *name, unsigned HOST_WIDE_INT size,
511 int align)
512 {
513 bss_section ();
514 ASM_OUTPUT_ALIGN (file, floor_log2 (align / BITS_PER_UNIT));
515 #ifdef ASM_DECLARE_OBJECT_NAME
516 last_assemble_variable_decl = decl;
517 ASM_DECLARE_OBJECT_NAME (file, name, decl);
518 #else
519 /* Standard thing is just output label for the object. */
520 ASM_OUTPUT_LABEL (file, name);
521 #endif /* ASM_DECLARE_OBJECT_NAME */
522 ASM_OUTPUT_SKIP (file, size ? size : 1);
523 }
524
525 #endif
526
527 #endif /* BSS_SECTION_ASM_OP */
528
529 /* Switch to the section for function DECL.
530
531 If DECL is NULL_TREE, switch to the text section.
532 ??? It's not clear that we will ever be passed NULL_TREE, but it's
533 safer to handle it. */
534
535 void
536 function_section (tree decl)
537 {
538 if (decl != NULL_TREE
539 && DECL_SECTION_NAME (decl) != NULL_TREE)
540 named_section (decl, (char *) 0, 0);
541 else
542 text_section ();
543 }
544
545 /* Switch to section for variable DECL. RELOC is the same as the
546 argument to SELECT_SECTION. */
547
548 void
549 variable_section (tree decl, int reloc)
550 {
551 if (IN_NAMED_SECTION (decl))
552 named_section (decl, NULL, reloc);
553 else
554 (*targetm.asm_out.select_section) (decl, reloc, DECL_ALIGN (decl));
555 }
556
557 /* Tell assembler to switch to the section for string merging. */
558
559 void
560 mergeable_string_section (tree decl ATTRIBUTE_UNUSED,
561 unsigned HOST_WIDE_INT align ATTRIBUTE_UNUSED,
562 unsigned int flags ATTRIBUTE_UNUSED)
563 {
564 #ifdef HAVE_GAS_SHF_MERGE
565 if (flag_merge_constants
566 && TREE_CODE (decl) == STRING_CST
567 && TREE_CODE (TREE_TYPE (decl)) == ARRAY_TYPE
568 && align <= 256
569 && TREE_STRING_LENGTH (decl) >= int_size_in_bytes (TREE_TYPE (decl)))
570 {
571 enum machine_mode mode;
572 unsigned int modesize;
573 const char *str;
574 int i, j, len, unit;
575 char name[30];
576
577 mode = TYPE_MODE (TREE_TYPE (TREE_TYPE (decl)));
578 modesize = GET_MODE_BITSIZE (mode);
579 if (modesize >= 8 && modesize <= 256
580 && (modesize & (modesize - 1)) == 0)
581 {
582 if (align < modesize)
583 align = modesize;
584
585 str = TREE_STRING_POINTER (decl);
586 len = TREE_STRING_LENGTH (decl);
587 unit = GET_MODE_SIZE (mode);
588
589 /* Check for embedded NUL characters. */
590 for (i = 0; i < len; i += unit)
591 {
592 for (j = 0; j < unit; j++)
593 if (str[i + j] != '\0')
594 break;
595 if (j == unit)
596 break;
597 }
598 if (i == len - unit)
599 {
600 sprintf (name, ".rodata.str%d.%d", modesize / 8,
601 (int) (align / 8));
602 flags |= (modesize / 8) | SECTION_MERGE | SECTION_STRINGS;
603 if (!i && modesize < align)
604 {
605 /* A "" string with requested alignment greater than
606 character size might cause a problem:
607 if some other string required even bigger
608 alignment than "", then linker might think the
609 "" is just part of padding after some other string
610 and not put it into the hash table initially.
611 But this means "" could have smaller alignment
612 than requested. */
613 #ifdef ASM_OUTPUT_SECTION_START
614 named_section_flags (name, flags);
615 ASM_OUTPUT_SECTION_START (asm_out_file);
616 #else
617 readonly_data_section ();
618 #endif
619 return;
620 }
621
622 named_section_flags (name, flags);
623 return;
624 }
625 }
626 }
627 #endif
628 readonly_data_section ();
629 }
630
631 /* Tell assembler to switch to the section for constant merging. */
632
633 void
634 mergeable_constant_section (enum machine_mode mode ATTRIBUTE_UNUSED,
635 unsigned HOST_WIDE_INT align ATTRIBUTE_UNUSED,
636 unsigned int flags ATTRIBUTE_UNUSED)
637 {
638 #ifdef HAVE_GAS_SHF_MERGE
639 unsigned int modesize = GET_MODE_BITSIZE (mode);
640
641 if (flag_merge_constants
642 && mode != VOIDmode
643 && mode != BLKmode
644 && modesize <= align
645 && align >= 8
646 && align <= 256
647 && (align & (align - 1)) == 0)
648 {
649 char name[24];
650
651 sprintf (name, ".rodata.cst%d", (int) (align / 8));
652 flags |= (align / 8) | SECTION_MERGE;
653 named_section_flags (name, flags);
654 return;
655 }
656 #endif
657 readonly_data_section ();
658 }
659 \f
660 /* Given NAME, a putative register name, discard any customary prefixes. */
661
662 static const char *
663 strip_reg_name (const char *name)
664 {
665 #ifdef REGISTER_PREFIX
666 if (!strncmp (name, REGISTER_PREFIX, strlen (REGISTER_PREFIX)))
667 name += strlen (REGISTER_PREFIX);
668 #endif
669 if (name[0] == '%' || name[0] == '#')
670 name++;
671 return name;
672 }
673 \f
674 /* Decode an `asm' spec for a declaration as a register name.
675 Return the register number, or -1 if nothing specified,
676 or -2 if the ASMSPEC is not `cc' or `memory' and is not recognized,
677 or -3 if ASMSPEC is `cc' and is not recognized,
678 or -4 if ASMSPEC is `memory' and is not recognized.
679 Accept an exact spelling or a decimal number.
680 Prefixes such as % are optional. */
681
682 int
683 decode_reg_name (const char *asmspec)
684 {
685 if (asmspec != 0)
686 {
687 int i;
688
689 /* Get rid of confusing prefixes. */
690 asmspec = strip_reg_name (asmspec);
691
692 /* Allow a decimal number as a "register name". */
693 for (i = strlen (asmspec) - 1; i >= 0; i--)
694 if (! ISDIGIT (asmspec[i]))
695 break;
696 if (asmspec[0] != 0 && i < 0)
697 {
698 i = atoi (asmspec);
699 if (i < FIRST_PSEUDO_REGISTER && i >= 0)
700 return i;
701 else
702 return -2;
703 }
704
705 for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
706 if (reg_names[i][0]
707 && ! strcmp (asmspec, strip_reg_name (reg_names[i])))
708 return i;
709
710 #ifdef ADDITIONAL_REGISTER_NAMES
711 {
712 static const struct { const char *const name; const int number; } table[]
713 = ADDITIONAL_REGISTER_NAMES;
714
715 for (i = 0; i < (int) ARRAY_SIZE (table); i++)
716 if (! strcmp (asmspec, table[i].name))
717 return table[i].number;
718 }
719 #endif /* ADDITIONAL_REGISTER_NAMES */
720
721 if (!strcmp (asmspec, "memory"))
722 return -4;
723
724 if (!strcmp (asmspec, "cc"))
725 return -3;
726
727 return -2;
728 }
729
730 return -1;
731 }
732 \f
733 /* Create the DECL_RTL for a VAR_DECL or FUNCTION_DECL. DECL should
734 have static storage duration. In other words, it should not be an
735 automatic variable, including PARM_DECLs.
736
737 There is, however, one exception: this function handles variables
738 explicitly placed in a particular register by the user.
739
740 ASMSPEC, if not 0, is the string which the user specified as the
741 assembler symbol name.
742
743 This is never called for PARM_DECL nodes. */
744
745 void
746 make_decl_rtl (tree decl, const char *asmspec)
747 {
748 const char *name = 0;
749 int reg_number;
750 rtx x;
751
752 /* Check that we are not being given an automatic variable. */
753 /* A weak alias has TREE_PUBLIC set but not the other bits. */
754 if (TREE_CODE (decl) == PARM_DECL
755 || TREE_CODE (decl) == RESULT_DECL
756 || (TREE_CODE (decl) == VAR_DECL
757 && !TREE_STATIC (decl)
758 && !TREE_PUBLIC (decl)
759 && !DECL_EXTERNAL (decl)
760 && !DECL_REGISTER (decl)))
761 abort ();
762 /* And that we were not given a type or a label. */
763 else if (TREE_CODE (decl) == TYPE_DECL
764 || TREE_CODE (decl) == LABEL_DECL)
765 abort ();
766
767 /* For a duplicate declaration, we can be called twice on the
768 same DECL node. Don't discard the RTL already made. */
769 if (DECL_RTL_SET_P (decl))
770 {
771 /* If the old RTL had the wrong mode, fix the mode. */
772 if (GET_MODE (DECL_RTL (decl)) != DECL_MODE (decl))
773 SET_DECL_RTL (decl, adjust_address_nv (DECL_RTL (decl),
774 DECL_MODE (decl), 0));
775
776 /* ??? Another way to do this would be to maintain a hashed
777 table of such critters. Instead of adding stuff to a DECL
778 to give certain attributes to it, we could use an external
779 hash map from DECL to set of attributes. */
780
781 /* Let the target reassign the RTL if it wants.
782 This is necessary, for example, when one machine specific
783 decl attribute overrides another. */
784 (* targetm.encode_section_info) (decl, DECL_RTL (decl), false);
785 return;
786 }
787
788 reg_number = decode_reg_name (asmspec);
789 if (reg_number == -2)
790 {
791 /* ASMSPEC is given, and not the name of a register. Mark the
792 name with a star so assemble_name won't munge it. */
793 char *starred = alloca (strlen (asmspec) + 2);
794 starred[0] = '*';
795 strcpy (starred + 1, asmspec);
796 SET_DECL_ASSEMBLER_NAME (decl, get_identifier (starred));
797 }
798
799 name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
800
801 if (TREE_CODE (decl) != FUNCTION_DECL && DECL_REGISTER (decl))
802 {
803 /* First detect errors in declaring global registers. */
804 if (reg_number == -1)
805 error_with_decl (decl, "register name not specified for `%s'");
806 else if (reg_number < 0)
807 error_with_decl (decl, "invalid register name for `%s'");
808 else if (TYPE_MODE (TREE_TYPE (decl)) == BLKmode)
809 error_with_decl (decl,
810 "data type of `%s' isn't suitable for a register");
811 else if (! HARD_REGNO_MODE_OK (reg_number, TYPE_MODE (TREE_TYPE (decl))))
812 error_with_decl (decl,
813 "register specified for `%s' isn't suitable for data type");
814 /* Now handle properly declared static register variables. */
815 else
816 {
817 int nregs;
818
819 if (DECL_INITIAL (decl) != 0 && TREE_STATIC (decl))
820 {
821 DECL_INITIAL (decl) = 0;
822 error ("global register variable has initial value");
823 }
824 if (TREE_THIS_VOLATILE (decl))
825 warning ("volatile register variables don't work as you might wish");
826
827 /* If the user specified one of the eliminables registers here,
828 e.g., FRAME_POINTER_REGNUM, we don't want to get this variable
829 confused with that register and be eliminated. This usage is
830 somewhat suspect... */
831
832 SET_DECL_RTL (decl, gen_rtx_raw_REG (DECL_MODE (decl), reg_number));
833 ORIGINAL_REGNO (DECL_RTL (decl)) = reg_number;
834 REG_USERVAR_P (DECL_RTL (decl)) = 1;
835
836 if (TREE_STATIC (decl))
837 {
838 /* Make this register global, so not usable for anything
839 else. */
840 #ifdef ASM_DECLARE_REGISTER_GLOBAL
841 ASM_DECLARE_REGISTER_GLOBAL (asm_out_file, decl, reg_number, name);
842 #endif
843 nregs = HARD_REGNO_NREGS (reg_number, DECL_MODE (decl));
844 while (nregs > 0)
845 globalize_reg (reg_number + --nregs);
846 }
847
848 /* As a register variable, it has no section. */
849 return;
850 }
851 }
852
853 /* Now handle ordinary static variables and functions (in memory).
854 Also handle vars declared register invalidly. */
855
856 if (reg_number >= 0 || reg_number == -3)
857 error_with_decl (decl,
858 "register name given for non-register variable `%s'");
859
860 /* Specifying a section attribute on a variable forces it into a
861 non-.bss section, and thus it cannot be common. */
862 if (TREE_CODE (decl) == VAR_DECL
863 && DECL_SECTION_NAME (decl) != NULL_TREE
864 && DECL_INITIAL (decl) == NULL_TREE
865 && DECL_COMMON (decl))
866 DECL_COMMON (decl) = 0;
867
868 /* Variables can't be both common and weak. */
869 if (TREE_CODE (decl) == VAR_DECL && DECL_WEAK (decl))
870 DECL_COMMON (decl) = 0;
871
872 x = gen_rtx_SYMBOL_REF (Pmode, name);
873 SYMBOL_REF_WEAK (x) = DECL_WEAK (decl);
874 SYMBOL_REF_DECL (x) = decl;
875
876 x = gen_rtx_MEM (DECL_MODE (decl), x);
877 if (TREE_CODE (decl) != FUNCTION_DECL)
878 set_mem_attributes (x, decl, 1);
879 SET_DECL_RTL (decl, x);
880
881 /* Optionally set flags or add text to the name to record information
882 such as that it is a function name.
883 If the name is changed, the macro ASM_OUTPUT_LABELREF
884 will have to know how to strip this information. */
885 (* targetm.encode_section_info) (decl, DECL_RTL (decl), true);
886 }
887
888 /* Make the rtl for variable VAR be volatile.
889 Use this only for static variables. */
890
891 void
892 make_var_volatile (tree var)
893 {
894 if (GET_CODE (DECL_RTL (var)) != MEM)
895 abort ();
896
897 MEM_VOLATILE_P (DECL_RTL (var)) = 1;
898 }
899 \f
900 /* Output a string of literal assembler code
901 for an `asm' keyword used between functions. */
902
903 void
904 assemble_asm (tree string)
905 {
906 app_enable ();
907
908 if (TREE_CODE (string) == ADDR_EXPR)
909 string = TREE_OPERAND (string, 0);
910
911 fprintf (asm_out_file, "\t%s\n", TREE_STRING_POINTER (string));
912 }
913
914 /* Record an element in the table of global destructors. SYMBOL is
915 a SYMBOL_REF of the function to be called; PRIORITY is a number
916 between 0 and MAX_INIT_PRIORITY. */
917
918 void
919 default_stabs_asm_out_destructor (rtx symbol, int priority ATTRIBUTE_UNUSED)
920 {
921 /* Tell GNU LD that this is part of the static destructor set.
922 This will work for any system that uses stabs, most usefully
923 aout systems. */
924 fprintf (asm_out_file, "%s\"___DTOR_LIST__\",22,0,0,", ASM_STABS_OP);
925 assemble_name (asm_out_file, XSTR (symbol, 0));
926 fputc ('\n', asm_out_file);
927 }
928
929 void
930 default_named_section_asm_out_destructor (rtx symbol, int priority)
931 {
932 const char *section = ".dtors";
933 char buf[16];
934
935 /* ??? This only works reliably with the GNU linker. */
936 if (priority != DEFAULT_INIT_PRIORITY)
937 {
938 sprintf (buf, ".dtors.%.5u",
939 /* Invert the numbering so the linker puts us in the proper
940 order; constructors are run from right to left, and the
941 linker sorts in increasing order. */
942 MAX_INIT_PRIORITY - priority);
943 section = buf;
944 }
945
946 named_section_flags (section, SECTION_WRITE);
947 assemble_align (POINTER_SIZE);
948 assemble_integer (symbol, POINTER_SIZE / BITS_PER_UNIT, POINTER_SIZE, 1);
949 }
950
951 #ifdef DTORS_SECTION_ASM_OP
952 void
953 dtors_section (void)
954 {
955 if (in_section != in_dtors)
956 {
957 in_section = in_dtors;
958 fputs (DTORS_SECTION_ASM_OP, asm_out_file);
959 fputc ('\n', asm_out_file);
960 }
961 }
962
963 void
964 default_dtor_section_asm_out_destructor (rtx symbol,
965 int priority ATTRIBUTE_UNUSED)
966 {
967 dtors_section ();
968 assemble_align (POINTER_SIZE);
969 assemble_integer (symbol, POINTER_SIZE / BITS_PER_UNIT, POINTER_SIZE, 1);
970 }
971 #endif
972
973 /* Likewise for global constructors. */
974
975 void
976 default_stabs_asm_out_constructor (rtx symbol, int priority ATTRIBUTE_UNUSED)
977 {
978 /* Tell GNU LD that this is part of the static destructor set.
979 This will work for any system that uses stabs, most usefully
980 aout systems. */
981 fprintf (asm_out_file, "%s\"___CTOR_LIST__\",22,0,0,", ASM_STABS_OP);
982 assemble_name (asm_out_file, XSTR (symbol, 0));
983 fputc ('\n', asm_out_file);
984 }
985
986 void
987 default_named_section_asm_out_constructor (rtx symbol, int priority)
988 {
989 const char *section = ".ctors";
990 char buf[16];
991
992 /* ??? This only works reliably with the GNU linker. */
993 if (priority != DEFAULT_INIT_PRIORITY)
994 {
995 sprintf (buf, ".ctors.%.5u",
996 /* Invert the numbering so the linker puts us in the proper
997 order; constructors are run from right to left, and the
998 linker sorts in increasing order. */
999 MAX_INIT_PRIORITY - priority);
1000 section = buf;
1001 }
1002
1003 named_section_flags (section, SECTION_WRITE);
1004 assemble_align (POINTER_SIZE);
1005 assemble_integer (symbol, POINTER_SIZE / BITS_PER_UNIT, POINTER_SIZE, 1);
1006 }
1007
1008 #ifdef CTORS_SECTION_ASM_OP
1009 void
1010 ctors_section (void)
1011 {
1012 if (in_section != in_ctors)
1013 {
1014 in_section = in_ctors;
1015 fputs (CTORS_SECTION_ASM_OP, asm_out_file);
1016 fputc ('\n', asm_out_file);
1017 }
1018 }
1019
1020 void
1021 default_ctor_section_asm_out_constructor (rtx symbol,
1022 int priority ATTRIBUTE_UNUSED)
1023 {
1024 ctors_section ();
1025 assemble_align (POINTER_SIZE);
1026 assemble_integer (symbol, POINTER_SIZE / BITS_PER_UNIT, POINTER_SIZE, 1);
1027 }
1028 #endif
1029 \f
1030 /* CONSTANT_POOL_BEFORE_FUNCTION may be defined as an expression with
1031 a nonzero value if the constant pool should be output before the
1032 start of the function, or a zero value if the pool should output
1033 after the end of the function. The default is to put it before the
1034 start. */
1035
1036 #ifndef CONSTANT_POOL_BEFORE_FUNCTION
1037 #define CONSTANT_POOL_BEFORE_FUNCTION 1
1038 #endif
1039
1040 /* Output assembler code for the constant pool of a function and associated
1041 with defining the name of the function. DECL describes the function.
1042 NAME is the function's name. For the constant pool, we use the current
1043 constant pool data. */
1044
1045 void
1046 assemble_start_function (tree decl, const char *fnname)
1047 {
1048 int align;
1049
1050 /* The following code does not need preprocessing in the assembler. */
1051
1052 app_disable ();
1053
1054 if (CONSTANT_POOL_BEFORE_FUNCTION)
1055 output_constant_pool (fnname, decl);
1056
1057 resolve_unique_section (decl, 0, flag_function_sections);
1058 function_section (decl);
1059
1060 /* Tell assembler to move to target machine's alignment for functions. */
1061 align = floor_log2 (FUNCTION_BOUNDARY / BITS_PER_UNIT);
1062 if (align < force_align_functions_log)
1063 align = force_align_functions_log;
1064 if (align > 0)
1065 {
1066 ASM_OUTPUT_ALIGN (asm_out_file, align);
1067 }
1068
1069 /* Handle a user-specified function alignment.
1070 Note that we still need to align to FUNCTION_BOUNDARY, as above,
1071 because ASM_OUTPUT_MAX_SKIP_ALIGN might not do any alignment at all. */
1072 if (align_functions_log > align
1073 && cfun->function_frequency != FUNCTION_FREQUENCY_UNLIKELY_EXECUTED)
1074 {
1075 #ifdef ASM_OUTPUT_MAX_SKIP_ALIGN
1076 ASM_OUTPUT_MAX_SKIP_ALIGN (asm_out_file,
1077 align_functions_log, align_functions - 1);
1078 #else
1079 ASM_OUTPUT_ALIGN (asm_out_file, align_functions_log);
1080 #endif
1081 }
1082
1083 #ifdef ASM_OUTPUT_FUNCTION_PREFIX
1084 ASM_OUTPUT_FUNCTION_PREFIX (asm_out_file, fnname);
1085 #endif
1086
1087 (*debug_hooks->begin_function) (decl);
1088
1089 /* Make function name accessible from other files, if appropriate. */
1090
1091 if (TREE_PUBLIC (decl))
1092 {
1093 if (! first_global_object_name)
1094 {
1095 const char *p;
1096 char *name;
1097
1098 p = (* targetm.strip_name_encoding) (fnname);
1099 name = xstrdup (p);
1100
1101 if (! DECL_WEAK (decl) && ! DECL_ONE_ONLY (decl))
1102 first_global_object_name = name;
1103 else
1104 weak_global_object_name = name;
1105 }
1106
1107 globalize_decl (decl);
1108
1109 maybe_assemble_visibility (decl);
1110 }
1111
1112 /* Do any machine/system dependent processing of the function name */
1113 #ifdef ASM_DECLARE_FUNCTION_NAME
1114 ASM_DECLARE_FUNCTION_NAME (asm_out_file, fnname, current_function_decl);
1115 #else
1116 /* Standard thing is just output label for the function. */
1117 ASM_OUTPUT_LABEL (asm_out_file, fnname);
1118 #endif /* ASM_DECLARE_FUNCTION_NAME */
1119 }
1120
1121 /* Output assembler code associated with defining the size of the
1122 function. DECL describes the function. NAME is the function's name. */
1123
1124 void
1125 assemble_end_function (tree decl, const char *fnname)
1126 {
1127 #ifdef ASM_DECLARE_FUNCTION_SIZE
1128 ASM_DECLARE_FUNCTION_SIZE (asm_out_file, fnname, decl);
1129 #endif
1130 if (! CONSTANT_POOL_BEFORE_FUNCTION)
1131 {
1132 output_constant_pool (fnname, decl);
1133 function_section (decl); /* need to switch back */
1134 }
1135 }
1136 \f
1137 /* Assemble code to leave SIZE bytes of zeros. */
1138
1139 void
1140 assemble_zeros (unsigned HOST_WIDE_INT size)
1141 {
1142 /* Do no output if -fsyntax-only. */
1143 if (flag_syntax_only)
1144 return;
1145
1146 #ifdef ASM_NO_SKIP_IN_TEXT
1147 /* The `space' pseudo in the text section outputs nop insns rather than 0s,
1148 so we must output 0s explicitly in the text section. */
1149 if (ASM_NO_SKIP_IN_TEXT && in_text_section ())
1150 {
1151 unsigned HOST_WIDE_INT i;
1152 for (i = 0; i < size; i++)
1153 assemble_integer (const0_rtx, 1, BITS_PER_UNIT, 1);
1154 }
1155 else
1156 #endif
1157 if (size > 0)
1158 ASM_OUTPUT_SKIP (asm_out_file, size);
1159 }
1160
1161 /* Assemble an alignment pseudo op for an ALIGN-bit boundary. */
1162
1163 void
1164 assemble_align (int align)
1165 {
1166 if (align > BITS_PER_UNIT)
1167 {
1168 ASM_OUTPUT_ALIGN (asm_out_file, floor_log2 (align / BITS_PER_UNIT));
1169 }
1170 }
1171
1172 /* Assemble a string constant with the specified C string as contents. */
1173
1174 void
1175 assemble_string (const char *p, int size)
1176 {
1177 int pos = 0;
1178 int maximum = 2000;
1179
1180 /* If the string is very long, split it up. */
1181
1182 while (pos < size)
1183 {
1184 int thissize = size - pos;
1185 if (thissize > maximum)
1186 thissize = maximum;
1187
1188 ASM_OUTPUT_ASCII (asm_out_file, p, thissize);
1189
1190 pos += thissize;
1191 p += thissize;
1192 }
1193 }
1194
1195 \f
1196 #if defined ASM_OUTPUT_ALIGNED_DECL_LOCAL
1197 #define ASM_EMIT_LOCAL(decl, name, size, rounded) \
1198 ASM_OUTPUT_ALIGNED_DECL_LOCAL (asm_out_file, decl, name, size, DECL_ALIGN (decl))
1199 #else
1200 #if defined ASM_OUTPUT_ALIGNED_LOCAL
1201 #define ASM_EMIT_LOCAL(decl, name, size, rounded) \
1202 ASM_OUTPUT_ALIGNED_LOCAL (asm_out_file, name, size, DECL_ALIGN (decl))
1203 #else
1204 #define ASM_EMIT_LOCAL(decl, name, size, rounded) \
1205 ASM_OUTPUT_LOCAL (asm_out_file, name, size, rounded)
1206 #endif
1207 #endif
1208
1209 #if defined ASM_OUTPUT_ALIGNED_BSS
1210 #define ASM_EMIT_BSS(decl, name, size, rounded) \
1211 ASM_OUTPUT_ALIGNED_BSS (asm_out_file, decl, name, size, DECL_ALIGN (decl))
1212 #else
1213 #if defined ASM_OUTPUT_BSS
1214 #define ASM_EMIT_BSS(decl, name, size, rounded) \
1215 ASM_OUTPUT_BSS (asm_out_file, decl, name, size, rounded)
1216 #else
1217 #undef ASM_EMIT_BSS
1218 #endif
1219 #endif
1220
1221 #if defined ASM_OUTPUT_ALIGNED_DECL_COMMON
1222 #define ASM_EMIT_COMMON(decl, name, size, rounded) \
1223 ASM_OUTPUT_ALIGNED_DECL_COMMON (asm_out_file, decl, name, size, DECL_ALIGN (decl))
1224 #else
1225 #if defined ASM_OUTPUT_ALIGNED_COMMON
1226 #define ASM_EMIT_COMMON(decl, name, size, rounded) \
1227 ASM_OUTPUT_ALIGNED_COMMON (asm_out_file, name, size, DECL_ALIGN (decl))
1228 #else
1229 #define ASM_EMIT_COMMON(decl, name, size, rounded) \
1230 ASM_OUTPUT_COMMON (asm_out_file, name, size, rounded)
1231 #endif
1232 #endif
1233
1234 static bool
1235 asm_emit_uninitialised (tree decl, const char *name,
1236 unsigned HOST_WIDE_INT size ATTRIBUTE_UNUSED,
1237 unsigned HOST_WIDE_INT rounded ATTRIBUTE_UNUSED)
1238 {
1239 enum
1240 {
1241 asm_dest_common,
1242 asm_dest_bss,
1243 asm_dest_local
1244 }
1245 destination = asm_dest_local;
1246
1247 /* ??? We should handle .bss via select_section mechanisms rather than
1248 via special target hooks. That would eliminate this special case. */
1249 if (TREE_PUBLIC (decl))
1250 {
1251 if (!DECL_COMMON (decl))
1252 #ifdef ASM_EMIT_BSS
1253 destination = asm_dest_bss;
1254 #else
1255 return false;
1256 #endif
1257 else
1258 destination = asm_dest_common;
1259 }
1260
1261 if (destination == asm_dest_bss)
1262 globalize_decl (decl);
1263 resolve_unique_section (decl, 0, flag_data_sections);
1264
1265 if (flag_shared_data)
1266 {
1267 switch (destination)
1268 {
1269 #ifdef ASM_OUTPUT_SHARED_BSS
1270 case asm_dest_bss:
1271 ASM_OUTPUT_SHARED_BSS (asm_out_file, decl, name, size, rounded);
1272 return;
1273 #endif
1274 #ifdef ASM_OUTPUT_SHARED_COMMON
1275 case asm_dest_common:
1276 ASM_OUTPUT_SHARED_COMMON (asm_out_file, name, size, rounded);
1277 return;
1278 #endif
1279 #ifdef ASM_OUTPUT_SHARED_LOCAL
1280 case asm_dest_local:
1281 ASM_OUTPUT_SHARED_LOCAL (asm_out_file, name, size, rounded);
1282 return;
1283 #endif
1284 default:
1285 break;
1286 }
1287 }
1288
1289 switch (destination)
1290 {
1291 #ifdef ASM_EMIT_BSS
1292 case asm_dest_bss:
1293 ASM_EMIT_BSS (decl, name, size, rounded);
1294 break;
1295 #endif
1296 case asm_dest_common:
1297 ASM_EMIT_COMMON (decl, name, size, rounded);
1298 break;
1299 case asm_dest_local:
1300 ASM_EMIT_LOCAL (decl, name, size, rounded);
1301 break;
1302 default:
1303 abort ();
1304 }
1305
1306 return true;
1307 }
1308
1309 /* Assemble everything that is needed for a variable or function declaration.
1310 Not used for automatic variables, and not used for function definitions.
1311 Should not be called for variables of incomplete structure type.
1312
1313 TOP_LEVEL is nonzero if this variable has file scope.
1314 AT_END is nonzero if this is the special handling, at end of compilation,
1315 to define things that have had only tentative definitions.
1316 DONT_OUTPUT_DATA if nonzero means don't actually output the
1317 initial value (that will be done by the caller). */
1318
1319 void
1320 assemble_variable (tree decl, int top_level ATTRIBUTE_UNUSED,
1321 int at_end ATTRIBUTE_UNUSED, int dont_output_data)
1322 {
1323 const char *name;
1324 unsigned int align;
1325 int reloc = 0;
1326 rtx decl_rtl;
1327
1328 if (lang_hooks.decls.prepare_assemble_variable)
1329 (*lang_hooks.decls.prepare_assemble_variable) (decl);
1330
1331 last_assemble_variable_decl = 0;
1332
1333 /* Normally no need to say anything here for external references,
1334 since assemble_external is called by the language-specific code
1335 when a declaration is first seen. */
1336
1337 if (DECL_EXTERNAL (decl))
1338 return;
1339
1340 /* Output no assembler code for a function declaration.
1341 Only definitions of functions output anything. */
1342
1343 if (TREE_CODE (decl) == FUNCTION_DECL)
1344 return;
1345
1346 /* Do nothing for global register variables. */
1347 if (DECL_RTL_SET_P (decl) && GET_CODE (DECL_RTL (decl)) == REG)
1348 {
1349 TREE_ASM_WRITTEN (decl) = 1;
1350 return;
1351 }
1352
1353 /* If type was incomplete when the variable was declared,
1354 see if it is complete now. */
1355
1356 if (DECL_SIZE (decl) == 0)
1357 layout_decl (decl, 0);
1358
1359 /* Still incomplete => don't allocate it; treat the tentative defn
1360 (which is what it must have been) as an `extern' reference. */
1361
1362 if (!dont_output_data && DECL_SIZE (decl) == 0)
1363 {
1364 error ("%Hstorage size of `%s' isn't known",
1365 &DECL_SOURCE_LOCATION (decl),
1366 IDENTIFIER_POINTER (DECL_NAME (decl)));
1367 TREE_ASM_WRITTEN (decl) = 1;
1368 return;
1369 }
1370
1371 /* The first declaration of a variable that comes through this function
1372 decides whether it is global (in C, has external linkage)
1373 or local (in C, has internal linkage). So do nothing more
1374 if this function has already run. */
1375
1376 if (TREE_ASM_WRITTEN (decl))
1377 return;
1378
1379 /* Make sure targetm.encode_section_info is invoked before we set
1380 ASM_WRITTEN. */
1381 decl_rtl = DECL_RTL (decl);
1382
1383 TREE_ASM_WRITTEN (decl) = 1;
1384
1385 /* Do no output if -fsyntax-only. */
1386 if (flag_syntax_only)
1387 return;
1388
1389 app_disable ();
1390
1391 if (! dont_output_data
1392 && ! host_integerp (DECL_SIZE_UNIT (decl), 1))
1393 {
1394 error_with_decl (decl, "size of variable `%s' is too large");
1395 return;
1396 }
1397
1398 name = XSTR (XEXP (decl_rtl, 0), 0);
1399 if (TREE_PUBLIC (decl) && DECL_NAME (decl)
1400 && ! first_global_object_name
1401 && ! (DECL_COMMON (decl) && (DECL_INITIAL (decl) == 0
1402 || DECL_INITIAL (decl) == error_mark_node))
1403 && ! DECL_WEAK (decl)
1404 && ! DECL_ONE_ONLY (decl))
1405 {
1406 const char *p;
1407 char *xname;
1408
1409 p = (* targetm.strip_name_encoding) (name);
1410 xname = xstrdup (p);
1411 first_global_object_name = xname;
1412 }
1413
1414 /* Compute the alignment of this data. */
1415
1416 align = DECL_ALIGN (decl);
1417
1418 /* In the case for initialing an array whose length isn't specified,
1419 where we have not yet been able to do the layout,
1420 figure out the proper alignment now. */
1421 if (dont_output_data && DECL_SIZE (decl) == 0
1422 && TREE_CODE (TREE_TYPE (decl)) == ARRAY_TYPE)
1423 align = MAX (align, TYPE_ALIGN (TREE_TYPE (TREE_TYPE (decl))));
1424
1425 /* Some object file formats have a maximum alignment which they support.
1426 In particular, a.out format supports a maximum alignment of 4. */
1427 #ifndef MAX_OFILE_ALIGNMENT
1428 #define MAX_OFILE_ALIGNMENT BIGGEST_ALIGNMENT
1429 #endif
1430 if (align > MAX_OFILE_ALIGNMENT)
1431 {
1432 warning_with_decl (decl,
1433 "alignment of `%s' is greater than maximum object file alignment. Using %d",
1434 MAX_OFILE_ALIGNMENT/BITS_PER_UNIT);
1435 align = MAX_OFILE_ALIGNMENT;
1436 }
1437
1438 /* On some machines, it is good to increase alignment sometimes. */
1439 if (! DECL_USER_ALIGN (decl))
1440 {
1441 #ifdef DATA_ALIGNMENT
1442 align = DATA_ALIGNMENT (TREE_TYPE (decl), align);
1443 #endif
1444 #ifdef CONSTANT_ALIGNMENT
1445 if (DECL_INITIAL (decl) != 0 && DECL_INITIAL (decl) != error_mark_node)
1446 align = CONSTANT_ALIGNMENT (DECL_INITIAL (decl), align);
1447 #endif
1448 }
1449
1450 /* Reset the alignment in case we have made it tighter, so we can benefit
1451 from it in get_pointer_alignment. */
1452 DECL_ALIGN (decl) = align;
1453 set_mem_align (decl_rtl, align);
1454
1455 if (TREE_PUBLIC (decl))
1456 maybe_assemble_visibility (decl);
1457
1458 /* Output any data that we will need to use the address of. */
1459 if (DECL_INITIAL (decl) == error_mark_node)
1460 reloc = contains_pointers_p (TREE_TYPE (decl)) ? 3 : 0;
1461 else if (DECL_INITIAL (decl))
1462 reloc = output_addressed_constants (DECL_INITIAL (decl));
1463 resolve_unique_section (decl, reloc, flag_data_sections);
1464
1465 /* Handle uninitialized definitions. */
1466
1467 /* If the decl has been given an explicit section name, then it
1468 isn't common, and shouldn't be handled as such. */
1469 if (DECL_SECTION_NAME (decl) || dont_output_data)
1470 ;
1471 /* We don't implement common thread-local data at present. */
1472 else if (DECL_THREAD_LOCAL (decl))
1473 {
1474 if (DECL_COMMON (decl))
1475 sorry ("thread-local COMMON data not implemented");
1476 }
1477 else if (DECL_INITIAL (decl) == 0
1478 || DECL_INITIAL (decl) == error_mark_node
1479 || (flag_zero_initialized_in_bss
1480 /* Leave constant zeroes in .rodata so they can be shared. */
1481 && !TREE_READONLY (decl)
1482 && initializer_zerop (DECL_INITIAL (decl))))
1483 {
1484 unsigned HOST_WIDE_INT size = tree_low_cst (DECL_SIZE_UNIT (decl), 1);
1485 unsigned HOST_WIDE_INT rounded = size;
1486
1487 /* Don't allocate zero bytes of common,
1488 since that means "undefined external" in the linker. */
1489 if (size == 0)
1490 rounded = 1;
1491
1492 /* Round size up to multiple of BIGGEST_ALIGNMENT bits
1493 so that each uninitialized object starts on such a boundary. */
1494 rounded += (BIGGEST_ALIGNMENT / BITS_PER_UNIT) - 1;
1495 rounded = (rounded / (BIGGEST_ALIGNMENT / BITS_PER_UNIT)
1496 * (BIGGEST_ALIGNMENT / BITS_PER_UNIT));
1497
1498 #if !defined(ASM_OUTPUT_ALIGNED_COMMON) && !defined(ASM_OUTPUT_ALIGNED_DECL_COMMON) && !defined(ASM_OUTPUT_ALIGNED_BSS)
1499 if ((unsigned HOST_WIDE_INT) DECL_ALIGN (decl) / BITS_PER_UNIT > rounded)
1500 warning_with_decl
1501 (decl, "requested alignment for %s is greater than implemented alignment of %d",rounded);
1502 #endif
1503
1504 /* If the target cannot output uninitialized but not common global data
1505 in .bss, then we have to use .data, so fall through. */
1506 if (asm_emit_uninitialised (decl, name, size, rounded))
1507 return;
1508 }
1509
1510 /* Handle initialized definitions.
1511 Also handle uninitialized global definitions if -fno-common and the
1512 target doesn't support ASM_OUTPUT_BSS. */
1513
1514 /* First make the assembler name(s) global if appropriate. */
1515 if (TREE_PUBLIC (decl) && DECL_NAME (decl))
1516 globalize_decl (decl);
1517
1518 /* Switch to the appropriate section. */
1519 variable_section (decl, reloc);
1520
1521 /* dbxout.c needs to know this. */
1522 if (in_text_section ())
1523 DECL_IN_TEXT_SECTION (decl) = 1;
1524
1525 /* Output the alignment of this data. */
1526 if (align > BITS_PER_UNIT)
1527 {
1528 ASM_OUTPUT_ALIGN (asm_out_file,
1529 floor_log2 (DECL_ALIGN (decl) / BITS_PER_UNIT));
1530 }
1531
1532 /* Do any machine/system dependent processing of the object. */
1533 #ifdef ASM_DECLARE_OBJECT_NAME
1534 last_assemble_variable_decl = decl;
1535 ASM_DECLARE_OBJECT_NAME (asm_out_file, name, decl);
1536 #else
1537 /* Standard thing is just output label for the object. */
1538 ASM_OUTPUT_LABEL (asm_out_file, name);
1539 #endif /* ASM_DECLARE_OBJECT_NAME */
1540
1541 if (!dont_output_data)
1542 {
1543 if (DECL_INITIAL (decl) && DECL_INITIAL (decl) != error_mark_node)
1544 /* Output the actual data. */
1545 output_constant (DECL_INITIAL (decl),
1546 tree_low_cst (DECL_SIZE_UNIT (decl), 1),
1547 align);
1548 else
1549 /* Leave space for it. */
1550 assemble_zeros (tree_low_cst (DECL_SIZE_UNIT (decl), 1));
1551 }
1552 }
1553
1554 /* Return 1 if type TYPE contains any pointers. */
1555
1556 static int
1557 contains_pointers_p (tree type)
1558 {
1559 switch (TREE_CODE (type))
1560 {
1561 case POINTER_TYPE:
1562 case REFERENCE_TYPE:
1563 /* I'm not sure whether OFFSET_TYPE needs this treatment,
1564 so I'll play safe and return 1. */
1565 case OFFSET_TYPE:
1566 return 1;
1567
1568 case RECORD_TYPE:
1569 case UNION_TYPE:
1570 case QUAL_UNION_TYPE:
1571 {
1572 tree fields;
1573 /* For a type that has fields, see if the fields have pointers. */
1574 for (fields = TYPE_FIELDS (type); fields; fields = TREE_CHAIN (fields))
1575 if (TREE_CODE (fields) == FIELD_DECL
1576 && contains_pointers_p (TREE_TYPE (fields)))
1577 return 1;
1578 return 0;
1579 }
1580
1581 case ARRAY_TYPE:
1582 /* An array type contains pointers if its element type does. */
1583 return contains_pointers_p (TREE_TYPE (type));
1584
1585 default:
1586 return 0;
1587 }
1588 }
1589
1590 /* Output something to declare an external symbol to the assembler.
1591 (Most assemblers don't need this, so we normally output nothing.)
1592 Do nothing if DECL is not external. */
1593
1594 void
1595 assemble_external (tree decl ATTRIBUTE_UNUSED)
1596 {
1597 /* Because most platforms do not define ASM_OUTPUT_EXTERNAL, the
1598 main body of this code is only rarely exercised. To provide some
1599 testing, on all platforms, we make sure that the ASM_OUT_FILE is
1600 open. If it's not, we should not be calling this function. */
1601 if (!asm_out_file)
1602 abort ();
1603
1604 #ifdef ASM_OUTPUT_EXTERNAL
1605 if (DECL_P (decl) && DECL_EXTERNAL (decl) && TREE_PUBLIC (decl))
1606 {
1607 rtx rtl = DECL_RTL (decl);
1608
1609 if (GET_CODE (rtl) == MEM && GET_CODE (XEXP (rtl, 0)) == SYMBOL_REF
1610 && ! SYMBOL_REF_USED (XEXP (rtl, 0)))
1611 {
1612 /* Some systems do require some output. */
1613 SYMBOL_REF_USED (XEXP (rtl, 0)) = 1;
1614 ASM_OUTPUT_EXTERNAL (asm_out_file, decl, XSTR (XEXP (rtl, 0), 0));
1615 }
1616 }
1617 #endif
1618 }
1619
1620 /* Similar, for calling a library function FUN. */
1621
1622 void
1623 assemble_external_libcall (rtx fun ATTRIBUTE_UNUSED)
1624 {
1625 #ifdef ASM_OUTPUT_EXTERNAL_LIBCALL
1626 /* Declare library function name external when first used, if nec. */
1627 if (! SYMBOL_REF_USED (fun))
1628 {
1629 SYMBOL_REF_USED (fun) = 1;
1630 ASM_OUTPUT_EXTERNAL_LIBCALL (asm_out_file, fun);
1631 }
1632 #endif
1633 }
1634
1635 /* Assemble a label named NAME. */
1636
1637 void
1638 assemble_label (const char *name)
1639 {
1640 ASM_OUTPUT_LABEL (asm_out_file, name);
1641 }
1642
1643 /* Set the symbol_referenced flag for ID and notify callgraph code. */
1644 void
1645 mark_referenced (tree id)
1646 {
1647 if (!TREE_SYMBOL_REFERENCED (id))
1648 {
1649 struct cgraph_node *node;
1650 struct cgraph_varpool_node *vnode;
1651
1652 if (!cgraph_global_info_ready)
1653 {
1654 node = cgraph_node_for_identifier (id);
1655 if (node)
1656 cgraph_mark_needed_node (node, 1);
1657 }
1658
1659 vnode = cgraph_varpool_node_for_identifier (id);
1660 if (vnode)
1661 cgraph_varpool_mark_needed_node (vnode);
1662 }
1663 TREE_SYMBOL_REFERENCED (id) = 1;
1664 }
1665
1666 /* Output to FILE a reference to the assembler name of a C-level name NAME.
1667 If NAME starts with a *, the rest of NAME is output verbatim.
1668 Otherwise NAME is transformed in an implementation-defined way
1669 (usually by the addition of an underscore).
1670 Many macros in the tm file are defined to call this function. */
1671
1672 void
1673 assemble_name (FILE *file, const char *name)
1674 {
1675 const char *real_name;
1676 tree id;
1677
1678 real_name = (* targetm.strip_name_encoding) (name);
1679
1680 id = maybe_get_identifier (real_name);
1681 if (id)
1682 mark_referenced (id);
1683
1684 if (name[0] == '*')
1685 fputs (&name[1], file);
1686 else
1687 ASM_OUTPUT_LABELREF (file, name);
1688 }
1689
1690 /* Allocate SIZE bytes writable static space with a gensym name
1691 and return an RTX to refer to its address. */
1692
1693 rtx
1694 assemble_static_space (unsigned HOST_WIDE_INT size)
1695 {
1696 char name[12];
1697 const char *namestring;
1698 rtx x;
1699
1700 #if 0
1701 if (flag_shared_data)
1702 data_section ();
1703 #endif
1704
1705 ASM_GENERATE_INTERNAL_LABEL (name, "LF", const_labelno);
1706 ++const_labelno;
1707 namestring = ggc_strdup (name);
1708
1709 x = gen_rtx_SYMBOL_REF (Pmode, namestring);
1710 SYMBOL_REF_FLAGS (x) = SYMBOL_FLAG_LOCAL;
1711
1712 #ifdef ASM_OUTPUT_ALIGNED_DECL_LOCAL
1713 ASM_OUTPUT_ALIGNED_DECL_LOCAL (asm_out_file, NULL_TREE, name, size,
1714 BIGGEST_ALIGNMENT);
1715 #else
1716 #ifdef ASM_OUTPUT_ALIGNED_LOCAL
1717 ASM_OUTPUT_ALIGNED_LOCAL (asm_out_file, name, size, BIGGEST_ALIGNMENT);
1718 #else
1719 {
1720 /* Round size up to multiple of BIGGEST_ALIGNMENT bits
1721 so that each uninitialized object starts on such a boundary. */
1722 /* Variable `rounded' might or might not be used in ASM_OUTPUT_LOCAL. */
1723 unsigned HOST_WIDE_INT rounded ATTRIBUTE_UNUSED
1724 = ((size + (BIGGEST_ALIGNMENT / BITS_PER_UNIT) - 1)
1725 / (BIGGEST_ALIGNMENT / BITS_PER_UNIT)
1726 * (BIGGEST_ALIGNMENT / BITS_PER_UNIT));
1727 ASM_OUTPUT_LOCAL (asm_out_file, name, size, rounded);
1728 }
1729 #endif
1730 #endif
1731 return x;
1732 }
1733
1734 /* Assemble the static constant template for function entry trampolines.
1735 This is done at most once per compilation.
1736 Returns an RTX for the address of the template. */
1737
1738 #ifdef TRAMPOLINE_TEMPLATE
1739 rtx
1740 assemble_trampoline_template (void)
1741 {
1742 char label[256];
1743 const char *name;
1744 int align;
1745 rtx symbol;
1746
1747 /* By default, put trampoline templates in read-only data section. */
1748
1749 #ifdef TRAMPOLINE_SECTION
1750 TRAMPOLINE_SECTION ();
1751 #else
1752 readonly_data_section ();
1753 #endif
1754
1755 /* Write the assembler code to define one. */
1756 align = floor_log2 (TRAMPOLINE_ALIGNMENT / BITS_PER_UNIT);
1757 if (align > 0)
1758 {
1759 ASM_OUTPUT_ALIGN (asm_out_file, align);
1760 }
1761
1762 (*targetm.asm_out.internal_label) (asm_out_file, "LTRAMP", 0);
1763 TRAMPOLINE_TEMPLATE (asm_out_file);
1764
1765 /* Record the rtl to refer to it. */
1766 ASM_GENERATE_INTERNAL_LABEL (label, "LTRAMP", 0);
1767 name = ggc_strdup (label);
1768 symbol = gen_rtx_SYMBOL_REF (Pmode, name);
1769 SYMBOL_REF_FLAGS (symbol) = SYMBOL_FLAG_LOCAL;
1770
1771 return symbol;
1772 }
1773 #endif
1774 \f
1775 /* A and B are either alignments or offsets. Return the minimum alignment
1776 that may be assumed after adding the two together. */
1777
1778 static inline unsigned
1779 min_align (unsigned int a, unsigned int b)
1780 {
1781 return (a | b) & -(a | b);
1782 }
1783
1784 /* Return the assembler directive for creating a given kind of integer
1785 object. SIZE is the number of bytes in the object and ALIGNED_P
1786 indicates whether it is known to be aligned. Return NULL if the
1787 assembly dialect has no such directive.
1788
1789 The returned string should be printed at the start of a new line and
1790 be followed immediately by the object's initial value. */
1791
1792 const char *
1793 integer_asm_op (int size, int aligned_p)
1794 {
1795 struct asm_int_op *ops;
1796
1797 if (aligned_p)
1798 ops = &targetm.asm_out.aligned_op;
1799 else
1800 ops = &targetm.asm_out.unaligned_op;
1801
1802 switch (size)
1803 {
1804 case 1:
1805 return targetm.asm_out.byte_op;
1806 case 2:
1807 return ops->hi;
1808 case 4:
1809 return ops->si;
1810 case 8:
1811 return ops->di;
1812 case 16:
1813 return ops->ti;
1814 default:
1815 return NULL;
1816 }
1817 }
1818
1819 /* Use directive OP to assemble an integer object X. Print OP at the
1820 start of the line, followed immediately by the value of X. */
1821
1822 void
1823 assemble_integer_with_op (const char *op, rtx x)
1824 {
1825 fputs (op, asm_out_file);
1826 output_addr_const (asm_out_file, x);
1827 fputc ('\n', asm_out_file);
1828 }
1829
1830 /* The default implementation of the asm_out.integer target hook. */
1831
1832 bool
1833 default_assemble_integer (rtx x ATTRIBUTE_UNUSED,
1834 unsigned int size ATTRIBUTE_UNUSED,
1835 int aligned_p ATTRIBUTE_UNUSED)
1836 {
1837 const char *op = integer_asm_op (size, aligned_p);
1838 return op && (assemble_integer_with_op (op, x), true);
1839 }
1840
1841 /* Assemble the integer constant X into an object of SIZE bytes. ALIGN is
1842 the alignment of the integer in bits. Return 1 if we were able to output
1843 the constant, otherwise 0. If FORCE is nonzero, abort if we can't output
1844 the constant. */
1845
1846 bool
1847 assemble_integer (rtx x, unsigned int size, unsigned int align, int force)
1848 {
1849 int aligned_p;
1850
1851 aligned_p = (align >= MIN (size * BITS_PER_UNIT, BIGGEST_ALIGNMENT));
1852
1853 /* See if the target hook can handle this kind of object. */
1854 if ((*targetm.asm_out.integer) (x, size, aligned_p))
1855 return true;
1856
1857 /* If the object is a multi-byte one, try splitting it up. Split
1858 it into words it if is multi-word, otherwise split it into bytes. */
1859 if (size > 1)
1860 {
1861 enum machine_mode omode, imode;
1862 unsigned int subalign;
1863 unsigned int subsize, i;
1864
1865 subsize = size > UNITS_PER_WORD? UNITS_PER_WORD : 1;
1866 subalign = MIN (align, subsize * BITS_PER_UNIT);
1867 omode = mode_for_size (subsize * BITS_PER_UNIT, MODE_INT, 0);
1868 imode = mode_for_size (size * BITS_PER_UNIT, MODE_INT, 0);
1869
1870 for (i = 0; i < size; i += subsize)
1871 {
1872 rtx partial = simplify_subreg (omode, x, imode, i);
1873 if (!partial || !assemble_integer (partial, subsize, subalign, 0))
1874 break;
1875 }
1876 if (i == size)
1877 return true;
1878
1879 /* If we've printed some of it, but not all of it, there's no going
1880 back now. */
1881 if (i > 0)
1882 abort ();
1883 }
1884
1885 if (force)
1886 abort ();
1887
1888 return false;
1889 }
1890 \f
1891 void
1892 assemble_real (REAL_VALUE_TYPE d, enum machine_mode mode, unsigned int align)
1893 {
1894 long data[4];
1895 long l;
1896 unsigned int nalign = min_align (align, 32);
1897
1898 switch (BITS_PER_UNIT)
1899 {
1900 case 8:
1901 switch (mode)
1902 {
1903 case SFmode:
1904 REAL_VALUE_TO_TARGET_SINGLE (d, l);
1905 assemble_integer (GEN_INT (l), 4, align, 1);
1906 break;
1907 case DFmode:
1908 REAL_VALUE_TO_TARGET_DOUBLE (d, data);
1909 assemble_integer (GEN_INT (data[0]), 4, align, 1);
1910 assemble_integer (GEN_INT (data[1]), 4, nalign, 1);
1911 break;
1912 case XFmode:
1913 REAL_VALUE_TO_TARGET_LONG_DOUBLE (d, data);
1914 assemble_integer (GEN_INT (data[0]), 4, align, 1);
1915 assemble_integer (GEN_INT (data[1]), 4, nalign, 1);
1916 assemble_integer (GEN_INT (data[2]), 4, nalign, 1);
1917 break;
1918 case TFmode:
1919 REAL_VALUE_TO_TARGET_LONG_DOUBLE (d, data);
1920 assemble_integer (GEN_INT (data[0]), 4, align, 1);
1921 assemble_integer (GEN_INT (data[1]), 4, nalign, 1);
1922 assemble_integer (GEN_INT (data[2]), 4, nalign, 1);
1923 assemble_integer (GEN_INT (data[3]), 4, nalign, 1);
1924 break;
1925 default:
1926 abort ();
1927 }
1928 break;
1929
1930 case 16:
1931 switch (mode)
1932 {
1933 case HFmode:
1934 REAL_VALUE_TO_TARGET_SINGLE (d, l);
1935 assemble_integer (GEN_INT (l), 2, align, 1);
1936 break;
1937 case TQFmode:
1938 REAL_VALUE_TO_TARGET_DOUBLE (d, data);
1939 assemble_integer (GEN_INT (data[0]), 2, align, 1);
1940 assemble_integer (GEN_INT (data[1]), 1, nalign, 1);
1941 break;
1942 default:
1943 abort ();
1944 }
1945 break;
1946
1947 case 32:
1948 switch (mode)
1949 {
1950 case QFmode:
1951 REAL_VALUE_TO_TARGET_SINGLE (d, l);
1952 assemble_integer (GEN_INT (l), 1, align, 1);
1953 break;
1954 case HFmode:
1955 REAL_VALUE_TO_TARGET_DOUBLE (d, data);
1956 assemble_integer (GEN_INT (data[0]), 1, align, 1);
1957 assemble_integer (GEN_INT (data[1]), 1, nalign, 1);
1958 break;
1959 default:
1960 abort ();
1961 }
1962 break;
1963
1964 default:
1965 abort ();
1966 }
1967 }
1968 \f
1969 /* Given an expression EXP with a constant value,
1970 reduce it to the sum of an assembler symbol and an integer.
1971 Store them both in the structure *VALUE.
1972 Abort if EXP does not reduce. */
1973
1974 struct addr_const GTY(())
1975 {
1976 rtx base;
1977 HOST_WIDE_INT offset;
1978 };
1979
1980 static void
1981 decode_addr_const (tree exp, struct addr_const *value)
1982 {
1983 tree target = TREE_OPERAND (exp, 0);
1984 int offset = 0;
1985 rtx x;
1986
1987 while (1)
1988 {
1989 if (TREE_CODE (target) == COMPONENT_REF
1990 && host_integerp (byte_position (TREE_OPERAND (target, 1)), 0))
1991
1992 {
1993 offset += int_byte_position (TREE_OPERAND (target, 1));
1994 target = TREE_OPERAND (target, 0);
1995 }
1996 else if (TREE_CODE (target) == ARRAY_REF
1997 || TREE_CODE (target) == ARRAY_RANGE_REF)
1998 {
1999 offset += (tree_low_cst (TYPE_SIZE_UNIT (TREE_TYPE (target)), 1)
2000 * tree_low_cst (TREE_OPERAND (target, 1), 0));
2001 target = TREE_OPERAND (target, 0);
2002 }
2003 else
2004 break;
2005 }
2006
2007 switch (TREE_CODE (target))
2008 {
2009 case VAR_DECL:
2010 case FUNCTION_DECL:
2011 x = DECL_RTL (target);
2012 break;
2013
2014 case LABEL_DECL:
2015 x = gen_rtx_MEM (FUNCTION_MODE,
2016 gen_rtx_LABEL_REF (VOIDmode, force_label_rtx (target)));
2017 break;
2018
2019 case REAL_CST:
2020 case STRING_CST:
2021 case COMPLEX_CST:
2022 case CONSTRUCTOR:
2023 case INTEGER_CST:
2024 x = output_constant_def (target, 1);
2025 break;
2026
2027 default:
2028 abort ();
2029 }
2030
2031 if (GET_CODE (x) != MEM)
2032 abort ();
2033 x = XEXP (x, 0);
2034
2035 value->base = x;
2036 value->offset = offset;
2037 }
2038 \f
2039 /* We do RTX_UNSPEC + XINT (blah), so nothing can go after RTX_UNSPEC. */
2040 enum kind { RTX_UNKNOWN, RTX_DOUBLE, RTX_VECTOR, RTX_INT, RTX_UNSPEC };
2041 struct rtx_const GTY(())
2042 {
2043 ENUM_BITFIELD(kind) kind : 16;
2044 ENUM_BITFIELD(machine_mode) mode : 16;
2045 union rtx_const_un {
2046 REAL_VALUE_TYPE GTY ((tag ("4"))) du;
2047 struct rtx_const_u_addr {
2048 rtx base;
2049 const char *symbol;
2050 HOST_WIDE_INT offset;
2051 } GTY ((tag ("1"))) addr;
2052 struct rtx_const_u_di {
2053 HOST_WIDE_INT high;
2054 HOST_WIDE_INT low;
2055 } GTY ((tag ("0"))) di;
2056
2057 /* The max vector size we have is 16 wide; two variants for
2058 integral and floating point vectors. */
2059 struct rtx_const_int_vec {
2060 HOST_WIDE_INT high;
2061 HOST_WIDE_INT low;
2062 } GTY ((tag ("2"))) int_vec[16];
2063
2064 REAL_VALUE_TYPE GTY ((tag ("3"))) fp_vec[8];
2065
2066 } GTY ((desc ("%1.kind >= RTX_INT"), descbits ("1"))) un;
2067 };
2068
2069 /* Uniquize all constants that appear in memory.
2070 Each constant in memory thus far output is recorded
2071 in `const_hash_table'. */
2072
2073 struct constant_descriptor_tree GTY(())
2074 {
2075 /* A MEM for the constant. */
2076 rtx rtl;
2077
2078 /* The value of the constant. */
2079 tree value;
2080 };
2081
2082 static GTY((param_is (struct constant_descriptor_tree)))
2083 htab_t const_desc_htab;
2084
2085 static struct constant_descriptor_tree * build_constant_desc (tree);
2086 static void maybe_output_constant_def_contents (struct constant_descriptor_tree *, int);
2087
2088 /* Compute a hash code for a constant expression. */
2089
2090 static hashval_t
2091 const_desc_hash (const void *ptr)
2092 {
2093 return const_hash_1 (((struct constant_descriptor_tree *)ptr)->value);
2094 }
2095
2096 static hashval_t
2097 const_hash_1 (const tree exp)
2098 {
2099 const char *p;
2100 hashval_t hi;
2101 int len, i;
2102 enum tree_code code = TREE_CODE (exp);
2103
2104 /* Either set P and LEN to the address and len of something to hash and
2105 exit the switch or return a value. */
2106
2107 switch (code)
2108 {
2109 case INTEGER_CST:
2110 p = (char *) &TREE_INT_CST (exp);
2111 len = sizeof TREE_INT_CST (exp);
2112 break;
2113
2114 case REAL_CST:
2115 return real_hash (TREE_REAL_CST_PTR (exp));
2116
2117 case STRING_CST:
2118 p = TREE_STRING_POINTER (exp);
2119 len = TREE_STRING_LENGTH (exp);
2120 break;
2121 case COMPLEX_CST:
2122 return (const_hash_1 (TREE_REALPART (exp)) * 5
2123 + const_hash_1 (TREE_IMAGPART (exp)));
2124
2125 case CONSTRUCTOR:
2126 if (TREE_CODE (TREE_TYPE (exp)) == SET_TYPE)
2127 {
2128 char *tmp;
2129
2130 len = int_size_in_bytes (TREE_TYPE (exp));
2131 tmp = alloca (len);
2132 get_set_constructor_bytes (exp, (unsigned char *) tmp, len);
2133 p = tmp;
2134 break;
2135 }
2136 else
2137 {
2138 tree link;
2139
2140 hi = 5 + int_size_in_bytes (TREE_TYPE (exp));
2141
2142 for (link = CONSTRUCTOR_ELTS (exp); link; link = TREE_CHAIN (link))
2143 if (TREE_VALUE (link))
2144 hi = hi * 603 + const_hash_1 (TREE_VALUE (link));
2145
2146 return hi;
2147 }
2148
2149 case ADDR_EXPR:
2150 case FDESC_EXPR:
2151 {
2152 struct addr_const value;
2153
2154 decode_addr_const (exp, &value);
2155 if (GET_CODE (value.base) == SYMBOL_REF)
2156 {
2157 /* Don't hash the address of the SYMBOL_REF;
2158 only use the offset and the symbol name. */
2159 hi = value.offset;
2160 p = XSTR (value.base, 0);
2161 for (i = 0; p[i] != 0; i++)
2162 hi = ((hi * 613) + (unsigned) (p[i]));
2163 }
2164 else if (GET_CODE (value.base) == LABEL_REF)
2165 hi = value.offset + CODE_LABEL_NUMBER (XEXP (value.base, 0)) * 13;
2166 else
2167 abort ();
2168 }
2169 return hi;
2170
2171 case PLUS_EXPR:
2172 case MINUS_EXPR:
2173 return (const_hash_1 (TREE_OPERAND (exp, 0)) * 9
2174 + const_hash_1 (TREE_OPERAND (exp, 1)));
2175
2176 case NOP_EXPR:
2177 case CONVERT_EXPR:
2178 case NON_LVALUE_EXPR:
2179 return const_hash_1 (TREE_OPERAND (exp, 0)) * 7 + 2;
2180
2181 default:
2182 /* A language specific constant. Just hash the code. */
2183 return code;
2184 }
2185
2186 /* Compute hashing function. */
2187 hi = len;
2188 for (i = 0; i < len; i++)
2189 hi = ((hi * 613) + (unsigned) (p[i]));
2190
2191 return hi;
2192 }
2193
2194 /* Wrapper of compare_constant, for the htab interface. */
2195 static int
2196 const_desc_eq (const void *p1, const void *p2)
2197 {
2198 return compare_constant (((struct constant_descriptor_tree *)p1)->value,
2199 ((struct constant_descriptor_tree *)p2)->value);
2200 }
2201
2202 /* Compare t1 and t2, and return 1 only if they are known to result in
2203 the same bit pattern on output. */
2204
2205 static int
2206 compare_constant (const tree t1, const tree t2)
2207 {
2208 enum tree_code typecode;
2209
2210 if (t1 == NULL_TREE)
2211 return t2 == NULL_TREE;
2212 if (t2 == NULL_TREE)
2213 return 0;
2214
2215 if (TREE_CODE (t1) != TREE_CODE (t2))
2216 return 0;
2217
2218 switch (TREE_CODE (t1))
2219 {
2220 case INTEGER_CST:
2221 /* Integer constants are the same only if the same width of type. */
2222 if (TYPE_PRECISION (TREE_TYPE (t1)) != TYPE_PRECISION (TREE_TYPE (t2)))
2223 return 0;
2224 return tree_int_cst_equal (t1, t2);
2225
2226 case REAL_CST:
2227 /* Real constants are the same only if the same width of type. */
2228 if (TYPE_PRECISION (TREE_TYPE (t1)) != TYPE_PRECISION (TREE_TYPE (t2)))
2229 return 0;
2230
2231 return REAL_VALUES_IDENTICAL (TREE_REAL_CST (t1), TREE_REAL_CST (t2));
2232
2233 case STRING_CST:
2234 if (flag_writable_strings)
2235 return 0;
2236
2237 if (TYPE_MODE (TREE_TYPE (t1)) != TYPE_MODE (TREE_TYPE (t2)))
2238 return 0;
2239
2240 return (TREE_STRING_LENGTH (t1) == TREE_STRING_LENGTH (t2)
2241 && ! memcmp (TREE_STRING_POINTER (t1), TREE_STRING_POINTER (t2),
2242 TREE_STRING_LENGTH (t1)));
2243
2244 case COMPLEX_CST:
2245 return (compare_constant (TREE_REALPART (t1), TREE_REALPART (t2))
2246 && compare_constant (TREE_IMAGPART (t1), TREE_IMAGPART (t2)));
2247
2248 case CONSTRUCTOR:
2249 typecode = TREE_CODE (TREE_TYPE (t1));
2250 if (typecode != TREE_CODE (TREE_TYPE (t2)))
2251 return 0;
2252
2253 if (typecode == SET_TYPE)
2254 {
2255 int len = int_size_in_bytes (TREE_TYPE (t2));
2256 unsigned char *tmp1, *tmp2;
2257
2258 if (int_size_in_bytes (TREE_TYPE (t1)) != len)
2259 return 0;
2260
2261 tmp1 = alloca (len);
2262 tmp2 = alloca (len);
2263
2264 if (get_set_constructor_bytes (t1, tmp1, len) != NULL_TREE)
2265 return 0;
2266 if (get_set_constructor_bytes (t2, tmp2, len) != NULL_TREE)
2267 return 0;
2268
2269 return memcmp (tmp1, tmp2, len) != 0;
2270 }
2271 else
2272 {
2273 tree l1, l2;
2274
2275 if (typecode == ARRAY_TYPE)
2276 {
2277 HOST_WIDE_INT size_1 = int_size_in_bytes (TREE_TYPE (t1));
2278 /* For arrays, check that the sizes all match. */
2279 if (TYPE_MODE (TREE_TYPE (t1)) != TYPE_MODE (TREE_TYPE (t2))
2280 || size_1 == -1
2281 || size_1 != int_size_in_bytes (TREE_TYPE (t2)))
2282 return 0;
2283 }
2284 else
2285 {
2286 /* For record and union constructors, require exact type
2287 equality. */
2288 if (TREE_TYPE (t1) != TREE_TYPE (t2))
2289 return 0;
2290 }
2291
2292 for (l1 = CONSTRUCTOR_ELTS (t1), l2 = CONSTRUCTOR_ELTS (t2);
2293 l1 && l2;
2294 l1 = TREE_CHAIN (l1), l2 = TREE_CHAIN (l2))
2295 {
2296 /* Check that each value is the same... */
2297 if (! compare_constant (TREE_VALUE (l1), TREE_VALUE (l2)))
2298 return 0;
2299 /* ... and that they apply to the same fields! */
2300 if (typecode == ARRAY_TYPE)
2301 {
2302 if (! compare_constant (TREE_PURPOSE (l1),
2303 TREE_PURPOSE (l2)))
2304 return 0;
2305 }
2306 else
2307 {
2308 if (TREE_PURPOSE (l1) != TREE_PURPOSE (l2))
2309 return 0;
2310 }
2311 }
2312
2313 return l1 == NULL_TREE && l2 == NULL_TREE;
2314 }
2315
2316 case ADDR_EXPR:
2317 case FDESC_EXPR:
2318 {
2319 struct addr_const value1, value2;
2320
2321 decode_addr_const (t1, &value1);
2322 decode_addr_const (t2, &value2);
2323 return (value1.offset == value2.offset
2324 && strcmp (XSTR (value1.base, 0), XSTR (value2.base, 0)) == 0);
2325 }
2326
2327 case PLUS_EXPR:
2328 case MINUS_EXPR:
2329 case RANGE_EXPR:
2330 return (compare_constant (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0))
2331 && compare_constant(TREE_OPERAND (t1, 1), TREE_OPERAND (t2, 1)));
2332
2333 case NOP_EXPR:
2334 case CONVERT_EXPR:
2335 case NON_LVALUE_EXPR:
2336 return compare_constant (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
2337
2338 default:
2339 {
2340 tree nt1, nt2;
2341 nt1 = (*lang_hooks.expand_constant) (t1);
2342 nt2 = (*lang_hooks.expand_constant) (t2);
2343 if (nt1 != t1 || nt2 != t2)
2344 return compare_constant (nt1, nt2);
2345 else
2346 return 0;
2347 }
2348 }
2349
2350 /* Should not get here. */
2351 abort ();
2352 }
2353 \f
2354 /* Make a copy of the whole tree structure for a constant. This
2355 handles the same types of nodes that compare_constant handles. */
2356
2357 static tree
2358 copy_constant (tree exp)
2359 {
2360 switch (TREE_CODE (exp))
2361 {
2362 case ADDR_EXPR:
2363 /* For ADDR_EXPR, we do not want to copy the decl whose address
2364 is requested. We do want to copy constants though. */
2365 if (TREE_CODE_CLASS (TREE_CODE (TREE_OPERAND (exp, 0))) == 'c')
2366 return build1 (TREE_CODE (exp), TREE_TYPE (exp),
2367 copy_constant (TREE_OPERAND (exp, 0)));
2368 else
2369 return copy_node (exp);
2370
2371 case INTEGER_CST:
2372 case REAL_CST:
2373 case STRING_CST:
2374 return copy_node (exp);
2375
2376 case COMPLEX_CST:
2377 return build_complex (TREE_TYPE (exp),
2378 copy_constant (TREE_REALPART (exp)),
2379 copy_constant (TREE_IMAGPART (exp)));
2380
2381 case PLUS_EXPR:
2382 case MINUS_EXPR:
2383 return build (TREE_CODE (exp), TREE_TYPE (exp),
2384 copy_constant (TREE_OPERAND (exp, 0)),
2385 copy_constant (TREE_OPERAND (exp, 1)));
2386
2387 case NOP_EXPR:
2388 case CONVERT_EXPR:
2389 case NON_LVALUE_EXPR:
2390 case VIEW_CONVERT_EXPR:
2391 return build1 (TREE_CODE (exp), TREE_TYPE (exp),
2392 copy_constant (TREE_OPERAND (exp, 0)));
2393
2394 case CONSTRUCTOR:
2395 {
2396 tree copy = copy_node (exp);
2397 tree list = copy_list (CONSTRUCTOR_ELTS (exp));
2398 tree tail;
2399
2400 CONSTRUCTOR_ELTS (copy) = list;
2401 for (tail = list; tail; tail = TREE_CHAIN (tail))
2402 TREE_VALUE (tail) = copy_constant (TREE_VALUE (tail));
2403 if (TREE_CODE (TREE_TYPE (exp)) == SET_TYPE)
2404 for (tail = list; tail; tail = TREE_CHAIN (tail))
2405 TREE_PURPOSE (tail) = copy_constant (TREE_PURPOSE (tail));
2406
2407 return copy;
2408 }
2409
2410 default:
2411 {
2412 tree t;
2413 t = (*lang_hooks.expand_constant) (exp);
2414 if (t != exp)
2415 return copy_constant (t);
2416 else
2417 abort ();
2418 }
2419 }
2420 }
2421 \f
2422 /* Subroutine of output_constant_def:
2423 No constant equal to EXP is known to have been output.
2424 Make a constant descriptor to enter EXP in the hash table.
2425 Assign the label number and construct RTL to refer to the
2426 constant's location in memory.
2427 Caller is responsible for updating the hash table. */
2428
2429 static struct constant_descriptor_tree *
2430 build_constant_desc (tree exp)
2431 {
2432 rtx symbol;
2433 rtx rtl;
2434 char label[256];
2435 int labelno;
2436 struct constant_descriptor_tree *desc;
2437
2438 desc = ggc_alloc (sizeof (*desc));
2439 desc->value = copy_constant (exp);
2440
2441 /* Create a string containing the label name, in LABEL. */
2442 labelno = const_labelno++;
2443 ASM_GENERATE_INTERNAL_LABEL (label, "LC", labelno);
2444
2445 /* We have a symbol name; construct the SYMBOL_REF and the MEM. */
2446 symbol = gen_rtx_SYMBOL_REF (Pmode, ggc_strdup (label));
2447 SYMBOL_REF_FLAGS (symbol) = SYMBOL_FLAG_LOCAL;
2448 SYMBOL_REF_DECL (symbol) = desc->value;
2449 TREE_CONSTANT_POOL_ADDRESS_P (symbol) = 1;
2450
2451 rtl = gen_rtx_MEM (TYPE_MODE (TREE_TYPE (exp)), symbol);
2452 set_mem_attributes (rtl, exp, 1);
2453 set_mem_alias_set (rtl, 0);
2454 set_mem_alias_set (rtl, const_alias_set);
2455
2456 /* Set flags or add text to the name to record information, such as
2457 that it is a local symbol. If the name is changed, the macro
2458 ASM_OUTPUT_LABELREF will have to know how to strip this
2459 information. This call might invalidate our local variable
2460 SYMBOL; we can't use it afterward. */
2461
2462 (*targetm.encode_section_info) (exp, rtl, true);
2463
2464 desc->rtl = rtl;
2465
2466 return desc;
2467 }
2468
2469 /* Return an rtx representing a reference to constant data in memory
2470 for the constant expression EXP.
2471
2472 If assembler code for such a constant has already been output,
2473 return an rtx to refer to it.
2474 Otherwise, output such a constant in memory
2475 and generate an rtx for it.
2476
2477 If DEFER is nonzero, this constant can be deferred and output only
2478 if referenced in the function after all optimizations.
2479
2480 The const_hash_table records which constants already have label strings. */
2481
2482 rtx
2483 output_constant_def (tree exp, int defer)
2484 {
2485 struct constant_descriptor_tree *desc;
2486 struct constant_descriptor_tree key;
2487 void **loc;
2488
2489 /* Look up EXP in the table of constant descriptors. If we didn't find
2490 it, create a new one. */
2491 key.value = exp;
2492 loc = htab_find_slot (const_desc_htab, &key, INSERT);
2493
2494 desc = *loc;
2495 if (desc == 0)
2496 {
2497 desc = build_constant_desc (exp);
2498 *loc = desc;
2499 }
2500
2501 maybe_output_constant_def_contents (desc, defer);
2502 return desc->rtl;
2503 }
2504
2505 /* Subroutine of output_constant_def: Decide whether or not we need to
2506 output the constant DESC now, and if so, do it. */
2507 static void
2508 maybe_output_constant_def_contents (struct constant_descriptor_tree *desc,
2509 int defer)
2510 {
2511 rtx symbol = XEXP (desc->rtl, 0);
2512 tree exp = desc->value;
2513
2514 if (flag_syntax_only)
2515 return;
2516
2517 if (TREE_ASM_WRITTEN (exp))
2518 /* Already output; don't do it again. */
2519 return;
2520
2521 /* The only constants that cannot safely be deferred, assuming the
2522 context allows it, are strings under flag_writable_strings. */
2523 if (defer && (TREE_CODE (exp) != STRING_CST || !flag_writable_strings))
2524 {
2525 /* Increment n_deferred_constants if it exists. It needs to be at
2526 least as large as the number of constants actually referred to
2527 by the function. If it's too small we'll stop looking too early
2528 and fail to emit constants; if it's too large we'll only look
2529 through the entire function when we could have stopped earlier. */
2530 if (cfun)
2531 n_deferred_constants++;
2532 return;
2533 }
2534
2535 output_constant_def_contents (symbol);
2536 }
2537
2538 /* We must output the constant data referred to by SYMBOL; do so. */
2539
2540 static void
2541 output_constant_def_contents (rtx symbol)
2542 {
2543 tree exp = SYMBOL_REF_DECL (symbol);
2544 const char *label = XSTR (symbol, 0);
2545
2546 /* Make sure any other constants whose addresses appear in EXP
2547 are assigned label numbers. */
2548 int reloc = output_addressed_constants (exp);
2549
2550 /* Align the location counter as required by EXP's data type. */
2551 int align = TYPE_ALIGN (TREE_TYPE (exp));
2552 #ifdef CONSTANT_ALIGNMENT
2553 align = CONSTANT_ALIGNMENT (exp, align);
2554 #endif
2555
2556 /* We are no longer deferring this constant. */
2557 TREE_ASM_WRITTEN (exp) = 1;
2558
2559 if (IN_NAMED_SECTION (exp))
2560 named_section (exp, NULL, reloc);
2561 else
2562 (*targetm.asm_out.select_section) (exp, reloc, align);
2563
2564 if (align > BITS_PER_UNIT)
2565 {
2566 ASM_OUTPUT_ALIGN (asm_out_file, floor_log2 (align / BITS_PER_UNIT));
2567 }
2568
2569 /* Output the label itself. */
2570 ASM_OUTPUT_LABEL (asm_out_file, label);
2571
2572 /* Output the value of EXP. */
2573 output_constant (exp,
2574 (TREE_CODE (exp) == STRING_CST
2575 ? MAX (TREE_STRING_LENGTH (exp),
2576 int_size_in_bytes (TREE_TYPE (exp)))
2577 : int_size_in_bytes (TREE_TYPE (exp))),
2578 align);
2579
2580 }
2581
2582 /* A constant which was deferred in its original location has been
2583 inserted by the RTL inliner into a different function. The
2584 current function's deferred constant count must be incremented. */
2585 void
2586 notice_rtl_inlining_of_deferred_constant (void)
2587 {
2588 n_deferred_constants++;
2589 }
2590 \f
2591 /* Used in the hash tables to avoid outputting the same constant
2592 twice. Unlike 'struct constant_descriptor_tree', RTX constants
2593 are output once per function, not once per file; there seems
2594 to be no reason for the difference. */
2595
2596 struct constant_descriptor_rtx GTY(())
2597 {
2598 /* More constant_descriptors with the same hash code. */
2599 struct constant_descriptor_rtx *next;
2600
2601 /* A MEM for the constant. */
2602 rtx rtl;
2603
2604 /* The value of the constant. */
2605 struct rtx_const value;
2606 };
2607
2608 /* Structure to represent sufficient information about a constant so that
2609 it can be output when the constant pool is output, so that function
2610 integration can be done, and to simplify handling on machines that reference
2611 constant pool as base+displacement. */
2612
2613 struct pool_constant GTY(())
2614 {
2615 struct constant_descriptor_rtx *desc;
2616 struct pool_constant *next;
2617 struct pool_constant *next_sym;
2618 rtx constant;
2619 enum machine_mode mode;
2620 int labelno;
2621 unsigned int align;
2622 HOST_WIDE_INT offset;
2623 int mark;
2624 };
2625
2626 /* Hash code for a SYMBOL_REF with CONSTANT_POOL_ADDRESS_P true.
2627 The argument is XSTR (... , 0) */
2628
2629 #define SYMHASH(LABEL) (((unsigned long) (LABEL)) % MAX_RTX_HASH_TABLE)
2630 \f
2631 /* Initialize constant pool hashing for a new function. */
2632
2633 void
2634 init_varasm_status (struct function *f)
2635 {
2636 struct varasm_status *p;
2637 p = ggc_alloc (sizeof (struct varasm_status));
2638 f->varasm = p;
2639 p->x_const_rtx_hash_table
2640 = ggc_alloc_cleared (MAX_RTX_HASH_TABLE
2641 * sizeof (struct constant_descriptor_rtx *));
2642 p->x_const_rtx_sym_hash_table
2643 = ggc_alloc_cleared (MAX_RTX_HASH_TABLE
2644 * sizeof (struct pool_constant *));
2645
2646 p->x_first_pool = p->x_last_pool = 0;
2647 p->x_pool_offset = 0;
2648 p->deferred_constants = 0;
2649 }
2650 \f
2651
2652 /* Express an rtx for a constant integer (perhaps symbolic)
2653 as the sum of a symbol or label plus an explicit integer.
2654 They are stored into VALUE. */
2655
2656 static void
2657 decode_rtx_const (enum machine_mode mode, rtx x, struct rtx_const *value)
2658 {
2659 /* Clear the whole structure, including any gaps. */
2660 memset (value, 0, sizeof (struct rtx_const));
2661
2662 value->kind = RTX_INT; /* Most usual kind. */
2663 value->mode = mode;
2664
2665 switch (GET_CODE (x))
2666 {
2667 case CONST_DOUBLE:
2668 value->kind = RTX_DOUBLE;
2669 if (GET_MODE (x) != VOIDmode)
2670 {
2671 const REAL_VALUE_TYPE *r = CONST_DOUBLE_REAL_VALUE (x);
2672
2673 value->mode = GET_MODE (x);
2674
2675 /* Copy the REAL_VALUE_TYPE by members so that we don't
2676 copy garbage from the original structure into our
2677 carefully cleaned hashing structure. */
2678 value->un.du.class = r->class;
2679 value->un.du.sign = r->sign;
2680 switch (r->class)
2681 {
2682 case rvc_zero:
2683 case rvc_inf:
2684 break;
2685 case rvc_normal:
2686 value->un.du.exp = r->exp;
2687 /* FALLTHRU */
2688 case rvc_nan:
2689 memcpy (value->un.du.sig, r->sig, sizeof (r->sig));
2690 break;
2691 default:
2692 abort ();
2693 }
2694 }
2695 else
2696 {
2697 value->un.di.low = CONST_DOUBLE_LOW (x);
2698 value->un.di.high = CONST_DOUBLE_HIGH (x);
2699 }
2700 break;
2701
2702 case CONST_VECTOR:
2703 {
2704 int units, i;
2705
2706 units = CONST_VECTOR_NUNITS (x);
2707 value->kind = RTX_VECTOR;
2708 value->mode = mode;
2709
2710 if (GET_MODE_CLASS (mode) == MODE_VECTOR_INT)
2711 {
2712 for (i = 0; i < units; ++i)
2713 {
2714 rtx elt = CONST_VECTOR_ELT (x, i);
2715 if (GET_CODE (elt) == CONST_INT)
2716 {
2717 value->un.int_vec[i].low = INTVAL (elt);
2718 value->un.int_vec[i].high = 0;
2719 }
2720 else
2721 {
2722 value->un.int_vec[i].low = CONST_DOUBLE_LOW (elt);
2723 value->un.int_vec[i].high = CONST_DOUBLE_HIGH (elt);
2724 }
2725 }
2726 }
2727 else if (GET_MODE_CLASS (mode) == MODE_VECTOR_FLOAT)
2728 {
2729 for (i = 0; i < units; ++i)
2730 {
2731 const REAL_VALUE_TYPE *r
2732 = CONST_DOUBLE_REAL_VALUE (CONST_VECTOR_ELT (x, i));
2733 REAL_VALUE_TYPE *d = &value->un.fp_vec[i];
2734
2735 /* Copy the REAL_VALUE_TYPE by members so that we don't
2736 copy garbage from the original structure into our
2737 carefully cleaned hashing structure. */
2738 d->class = r->class;
2739 d->sign = r->sign;
2740 switch (r->class)
2741 {
2742 case rvc_zero:
2743 case rvc_inf:
2744 break;
2745 case rvc_normal:
2746 d->exp = r->exp;
2747 /* FALLTHRU */
2748 case rvc_nan:
2749 memcpy (d->sig, r->sig, sizeof (r->sig));
2750 break;
2751 default:
2752 abort ();
2753 }
2754 }
2755 }
2756 else
2757 abort ();
2758 }
2759 break;
2760
2761 case CONST_INT:
2762 value->un.addr.offset = INTVAL (x);
2763 break;
2764
2765 case SYMBOL_REF:
2766 case LABEL_REF:
2767 case PC:
2768 value->un.addr.base = x;
2769 break;
2770
2771 case CONST:
2772 x = XEXP (x, 0);
2773 if (GET_CODE (x) == PLUS && GET_CODE (XEXP (x, 1)) == CONST_INT)
2774 {
2775 value->un.addr.base = XEXP (x, 0);
2776 value->un.addr.offset = INTVAL (XEXP (x, 1));
2777 }
2778 else if (GET_CODE (x) == MINUS && GET_CODE (XEXP (x, 1)) == CONST_INT)
2779 {
2780 value->un.addr.base = XEXP (x, 0);
2781 value->un.addr.offset = - INTVAL (XEXP (x, 1));
2782 }
2783 else
2784 {
2785 value->un.addr.base = x;
2786 value->un.addr.offset = 0;
2787 }
2788 break;
2789
2790 default:
2791 value->kind = RTX_UNKNOWN;
2792 break;
2793 }
2794
2795 if (value->kind == RTX_INT && value->un.addr.base != 0
2796 && GET_CODE (value->un.addr.base) == UNSPEC)
2797 {
2798 /* For a simple UNSPEC, the base is set to the
2799 operand, the kind field is set to the index of
2800 the unspec expression.
2801 Together with the code below, in case that
2802 the operand is a SYMBOL_REF or LABEL_REF,
2803 the address of the string or the code_label
2804 is taken as base. */
2805 if (XVECLEN (value->un.addr.base, 0) == 1)
2806 {
2807 value->kind = RTX_UNSPEC + XINT (value->un.addr.base, 1);
2808 value->un.addr.base = XVECEXP (value->un.addr.base, 0, 0);
2809 }
2810 }
2811
2812 if (value->kind >= RTX_INT && value->un.addr.base != 0)
2813 switch (GET_CODE (value->un.addr.base))
2814 {
2815 case SYMBOL_REF:
2816 /* Use the string's address, not the SYMBOL_REF's address,
2817 for the sake of addresses of library routines. */
2818 value->un.addr.symbol = XSTR (value->un.addr.base, 0);
2819 value->un.addr.base = NULL_RTX;
2820 break;
2821
2822 case LABEL_REF:
2823 /* For a LABEL_REF, compare labels. */
2824 value->un.addr.base = XEXP (value->un.addr.base, 0);
2825
2826 default:
2827 break;
2828 }
2829 }
2830
2831 /* Given a MINUS expression, simplify it if both sides
2832 include the same symbol. */
2833
2834 rtx
2835 simplify_subtraction (rtx x)
2836 {
2837 struct rtx_const val0, val1;
2838
2839 decode_rtx_const (GET_MODE (x), XEXP (x, 0), &val0);
2840 decode_rtx_const (GET_MODE (x), XEXP (x, 1), &val1);
2841
2842 if (val0.kind >= RTX_INT
2843 && val0.kind == val1.kind
2844 && val0.un.addr.base == val1.un.addr.base
2845 && val0.un.addr.symbol == val1.un.addr.symbol)
2846 return GEN_INT (val0.un.addr.offset - val1.un.addr.offset);
2847
2848 return x;
2849 }
2850
2851 /* Compute a hash code for a constant RTL expression. */
2852
2853 static unsigned int
2854 const_hash_rtx (enum machine_mode mode, rtx x)
2855 {
2856 union {
2857 struct rtx_const value;
2858 unsigned int data[sizeof(struct rtx_const) / sizeof (unsigned int)];
2859 } u;
2860
2861 unsigned int hi;
2862 size_t i;
2863
2864 decode_rtx_const (mode, x, &u.value);
2865
2866 /* Compute hashing function. */
2867 hi = 0;
2868 for (i = 0; i < ARRAY_SIZE (u.data); i++)
2869 hi = hi * 613 + u.data[i];
2870
2871 return hi % MAX_RTX_HASH_TABLE;
2872 }
2873
2874 /* Compare a constant rtl object X with a constant-descriptor DESC.
2875 Return 1 if DESC describes a constant with the same value as X. */
2876
2877 static int
2878 compare_constant_rtx (enum machine_mode mode, rtx x,
2879 struct constant_descriptor_rtx *desc)
2880 {
2881 struct rtx_const value;
2882
2883 decode_rtx_const (mode, x, &value);
2884
2885 /* Compare constant contents. */
2886 return memcmp (&value, &desc->value, sizeof (struct rtx_const)) == 0;
2887 }
2888
2889 /* Construct a constant descriptor for the rtl-expression X.
2890 It is up to the caller to enter the descriptor in the hash table. */
2891
2892 static struct constant_descriptor_rtx *
2893 record_constant_rtx (enum machine_mode mode, rtx x)
2894 {
2895 struct constant_descriptor_rtx *ptr;
2896
2897 ptr = ggc_alloc (sizeof (*ptr));
2898 decode_rtx_const (mode, x, &ptr->value);
2899
2900 return ptr;
2901 }
2902 \f
2903 /* Given a constant rtx X, make (or find) a memory constant for its value
2904 and return a MEM rtx to refer to it in memory. */
2905
2906 rtx
2907 force_const_mem (enum machine_mode mode, rtx x)
2908 {
2909 int hash;
2910 struct constant_descriptor_rtx *desc;
2911 char label[256];
2912 rtx def, symbol;
2913 struct pool_constant *pool;
2914 unsigned int align;
2915
2916 /* If we're not allowed to drop X into the constant pool, don't. */
2917 if ((*targetm.cannot_force_const_mem) (x))
2918 return NULL_RTX;
2919
2920 /* Compute hash code of X. Search the descriptors for that hash code
2921 to see if any of them describes X. If yes, we have an rtx to use. */
2922 hash = const_hash_rtx (mode, x);
2923 for (desc = const_rtx_hash_table[hash]; desc; desc = desc->next)
2924 if (compare_constant_rtx (mode, x, desc))
2925 return desc->rtl;
2926
2927 /* No constant equal to X is known to have been output.
2928 Make a constant descriptor to enter X in the hash table
2929 and make a MEM for it. */
2930 desc = record_constant_rtx (mode, x);
2931 desc->next = const_rtx_hash_table[hash];
2932 const_rtx_hash_table[hash] = desc;
2933
2934 /* Align the location counter as required by EXP's data type. */
2935 align = GET_MODE_ALIGNMENT (mode == VOIDmode ? word_mode : mode);
2936 #ifdef CONSTANT_ALIGNMENT
2937 {
2938 tree type = (*lang_hooks.types.type_for_mode) (mode, 0);
2939 if (type != NULL_TREE)
2940 align = CONSTANT_ALIGNMENT (make_tree (type, x), align);
2941 }
2942 #endif
2943
2944 pool_offset += (align / BITS_PER_UNIT) - 1;
2945 pool_offset &= ~ ((align / BITS_PER_UNIT) - 1);
2946
2947 if (GET_CODE (x) == LABEL_REF)
2948 LABEL_PRESERVE_P (XEXP (x, 0)) = 1;
2949
2950 /* Allocate a pool constant descriptor, fill it in, and chain it in. */
2951 pool = ggc_alloc (sizeof (struct pool_constant));
2952 pool->desc = desc;
2953 pool->constant = x;
2954 pool->mode = mode;
2955 pool->labelno = const_labelno;
2956 pool->align = align;
2957 pool->offset = pool_offset;
2958 pool->mark = 1;
2959 pool->next = 0;
2960
2961 if (last_pool == 0)
2962 first_pool = pool;
2963 else
2964 last_pool->next = pool;
2965
2966 last_pool = pool;
2967 pool_offset += GET_MODE_SIZE (mode);
2968
2969 /* Create a string containing the label name, in LABEL. */
2970 ASM_GENERATE_INTERNAL_LABEL (label, "LC", const_labelno);
2971
2972 ++const_labelno;
2973
2974 /* Construct the SYMBOL_REF and the MEM. */
2975
2976 symbol = gen_rtx_SYMBOL_REF (Pmode, ggc_strdup (label));
2977 SYMBOL_REF_FLAGS (symbol) = SYMBOL_FLAG_LOCAL;
2978
2979 pool->desc->rtl = def = gen_rtx_MEM (mode, symbol);
2980 set_mem_attributes (def, (*lang_hooks.types.type_for_mode) (mode, 0), 1);
2981 RTX_UNCHANGING_P (def) = 1;
2982
2983 /* Add label to symbol hash table. */
2984 hash = SYMHASH (XSTR (symbol, 0));
2985 pool->next_sym = const_rtx_sym_hash_table[hash];
2986 const_rtx_sym_hash_table[hash] = pool;
2987
2988 /* Mark the symbol_ref as belonging to this constants pool. */
2989 CONSTANT_POOL_ADDRESS_P (symbol) = 1;
2990 SYMBOL_REF_FLAGS (symbol) = SYMBOL_FLAG_LOCAL;
2991 current_function_uses_const_pool = 1;
2992
2993 return def;
2994 }
2995 \f
2996 /* Given a SYMBOL_REF with CONSTANT_POOL_ADDRESS_P true, return a pointer to
2997 the corresponding pool_constant structure. */
2998
2999 static struct pool_constant *
3000 find_pool_constant (struct function *f, rtx addr)
3001 {
3002 struct pool_constant *pool;
3003 const char *label = XSTR (addr, 0);
3004
3005 for (pool = f->varasm->x_const_rtx_sym_hash_table[SYMHASH (label)]; pool;
3006 pool = pool->next_sym)
3007 if (XSTR (XEXP (pool->desc->rtl, 0), 0) == label)
3008 return pool;
3009
3010 abort ();
3011 }
3012
3013 /* Given a constant pool SYMBOL_REF, return the corresponding constant. */
3014
3015 rtx
3016 get_pool_constant (rtx addr)
3017 {
3018 return (find_pool_constant (cfun, addr))->constant;
3019 }
3020
3021 /* Given a constant pool SYMBOL_REF, return the corresponding constant
3022 and whether it has been output or not. */
3023
3024 rtx
3025 get_pool_constant_mark (rtx addr, bool *pmarked)
3026 {
3027 struct pool_constant *pool = find_pool_constant (cfun, addr);
3028 *pmarked = (pool->mark != 0);
3029 return pool->constant;
3030 }
3031
3032 /* Likewise, but for the constant pool of a specific function. */
3033
3034 rtx
3035 get_pool_constant_for_function (struct function *f, rtx addr)
3036 {
3037 return (find_pool_constant (f, addr))->constant;
3038 }
3039
3040 /* Similar, return the mode. */
3041
3042 enum machine_mode
3043 get_pool_mode (rtx addr)
3044 {
3045 return (find_pool_constant (cfun, addr))->mode;
3046 }
3047
3048 enum machine_mode
3049 get_pool_mode_for_function (struct function *f, rtx addr)
3050 {
3051 return (find_pool_constant (f, addr))->mode;
3052 }
3053
3054 /* Similar, return the offset in the constant pool. */
3055
3056 int
3057 get_pool_offset (rtx addr)
3058 {
3059 return (find_pool_constant (cfun, addr))->offset;
3060 }
3061
3062 /* Return the size of the constant pool. */
3063
3064 int
3065 get_pool_size (void)
3066 {
3067 return pool_offset;
3068 }
3069 \f
3070 /* Write all the constants in the constant pool. */
3071
3072 void
3073 output_constant_pool (const char *fnname ATTRIBUTE_UNUSED,
3074 tree fndecl ATTRIBUTE_UNUSED)
3075 {
3076 struct pool_constant *pool;
3077 rtx x;
3078 REAL_VALUE_TYPE r;
3079
3080 /* It is possible for gcc to call force_const_mem and then to later
3081 discard the instructions which refer to the constant. In such a
3082 case we do not need to output the constant. */
3083 mark_constant_pool ();
3084
3085 #ifdef ASM_OUTPUT_POOL_PROLOGUE
3086 ASM_OUTPUT_POOL_PROLOGUE (asm_out_file, fnname, fndecl, pool_offset);
3087 #endif
3088
3089 for (pool = first_pool; pool; pool = pool->next)
3090 {
3091 rtx tmp;
3092
3093 x = pool->constant;
3094
3095 if (! pool->mark)
3096 continue;
3097
3098 /* See if X is a LABEL_REF (or a CONST referring to a LABEL_REF)
3099 whose CODE_LABEL has been deleted. This can occur if a jump table
3100 is eliminated by optimization. If so, write a constant of zero
3101 instead. Note that this can also happen by turning the
3102 CODE_LABEL into a NOTE. */
3103 /* ??? This seems completely and utterly wrong. Certainly it's
3104 not true for NOTE_INSN_DELETED_LABEL, but I disbelieve proper
3105 functioning even with INSN_DELETED_P and friends. */
3106
3107 tmp = x;
3108 switch (GET_CODE (x))
3109 {
3110 case CONST:
3111 if (GET_CODE (XEXP (x, 0)) != PLUS
3112 || GET_CODE (XEXP (XEXP (x, 0), 0)) != LABEL_REF)
3113 break;
3114 tmp = XEXP (XEXP (x, 0), 0);
3115 /* FALLTHRU */
3116
3117 case LABEL_REF:
3118 tmp = XEXP (x, 0);
3119 if (INSN_DELETED_P (tmp)
3120 || (GET_CODE (tmp) == NOTE
3121 && NOTE_LINE_NUMBER (tmp) == NOTE_INSN_DELETED))
3122 {
3123 abort ();
3124 x = const0_rtx;
3125 }
3126 break;
3127
3128 default:
3129 break;
3130 }
3131
3132 /* First switch to correct section. */
3133 (*targetm.asm_out.select_rtx_section) (pool->mode, x, pool->align);
3134
3135 #ifdef ASM_OUTPUT_SPECIAL_POOL_ENTRY
3136 ASM_OUTPUT_SPECIAL_POOL_ENTRY (asm_out_file, x, pool->mode,
3137 pool->align, pool->labelno, done);
3138 #endif
3139
3140 assemble_align (pool->align);
3141
3142 /* Output the label. */
3143 (*targetm.asm_out.internal_label) (asm_out_file, "LC", pool->labelno);
3144
3145 /* Output the value of the constant itself. */
3146 switch (GET_MODE_CLASS (pool->mode))
3147 {
3148 case MODE_FLOAT:
3149 if (GET_CODE (x) != CONST_DOUBLE)
3150 abort ();
3151
3152 REAL_VALUE_FROM_CONST_DOUBLE (r, x);
3153 assemble_real (r, pool->mode, pool->align);
3154 break;
3155
3156 case MODE_INT:
3157 case MODE_PARTIAL_INT:
3158 assemble_integer (x, GET_MODE_SIZE (pool->mode), pool->align, 1);
3159 break;
3160
3161 case MODE_VECTOR_FLOAT:
3162 {
3163 int i, units;
3164 rtx elt;
3165
3166 if (GET_CODE (x) != CONST_VECTOR)
3167 abort ();
3168
3169 units = CONST_VECTOR_NUNITS (x);
3170
3171 for (i = 0; i < units; i++)
3172 {
3173 elt = CONST_VECTOR_ELT (x, i);
3174 REAL_VALUE_FROM_CONST_DOUBLE (r, elt);
3175 assemble_real (r, GET_MODE_INNER (pool->mode), pool->align);
3176 }
3177 }
3178 break;
3179
3180 case MODE_VECTOR_INT:
3181 {
3182 int i, units;
3183 rtx elt;
3184
3185 if (GET_CODE (x) != CONST_VECTOR)
3186 abort ();
3187
3188 units = CONST_VECTOR_NUNITS (x);
3189
3190 for (i = 0; i < units; i++)
3191 {
3192 elt = CONST_VECTOR_ELT (x, i);
3193 assemble_integer (elt, GET_MODE_UNIT_SIZE (pool->mode),
3194 pool->align, 1);
3195 }
3196 }
3197 break;
3198
3199 default:
3200 abort ();
3201 }
3202
3203 /* Make sure all constants in SECTION_MERGE and not SECTION_STRINGS
3204 sections have proper size. */
3205 if (pool->align > GET_MODE_BITSIZE (pool->mode)
3206 && in_section == in_named
3207 && get_named_section_flags (in_named_name) & SECTION_MERGE)
3208 assemble_align (pool->align);
3209
3210 #ifdef ASM_OUTPUT_SPECIAL_POOL_ENTRY
3211 done: ;
3212 #endif
3213 }
3214
3215 #ifdef ASM_OUTPUT_POOL_EPILOGUE
3216 ASM_OUTPUT_POOL_EPILOGUE (asm_out_file, fnname, fndecl, pool_offset);
3217 #endif
3218
3219 /* Done with this pool. */
3220 first_pool = last_pool = 0;
3221 }
3222
3223 /* Look through the instructions for this function, and mark all the
3224 entries in the constant pool which are actually being used. Emit
3225 deferred constants which have indeed been used. */
3226
3227 static void
3228 mark_constant_pool (void)
3229 {
3230 rtx insn;
3231 rtx link;
3232 struct pool_constant *pool;
3233
3234 if (first_pool == 0 && n_deferred_constants == 0)
3235 return;
3236
3237 for (pool = first_pool; pool; pool = pool->next)
3238 pool->mark = 0;
3239
3240 for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
3241 if (INSN_P (insn))
3242 mark_constants (PATTERN (insn));
3243
3244 for (link = current_function_epilogue_delay_list;
3245 link;
3246 link = XEXP (link, 1))
3247 {
3248 insn = XEXP (link, 0);
3249
3250 if (INSN_P (insn))
3251 mark_constants (PATTERN (insn));
3252 }
3253 }
3254
3255 /* Look through appropriate parts of X, marking all entries in the
3256 constant pool which are actually being used. Entries that are only
3257 referenced by other constants are also marked as used. Emit
3258 deferred strings that are used. */
3259
3260 static void
3261 mark_constants (rtx x)
3262 {
3263 int i;
3264 const char *format_ptr;
3265
3266 if (x == 0)
3267 return;
3268
3269 if (GET_CODE (x) == SYMBOL_REF)
3270 {
3271 mark_constant (&x, NULL);
3272 return;
3273 }
3274
3275 /* Insns may appear inside a SEQUENCE. Only check the patterns of
3276 insns, not any notes that may be attached. We don't want to mark
3277 a constant just because it happens to appear in a REG_EQUIV note. */
3278 if (INSN_P (x))
3279 {
3280 mark_constants (PATTERN (x));
3281 return;
3282 }
3283
3284 format_ptr = GET_RTX_FORMAT (GET_CODE (x));
3285
3286 for (i = 0; i < GET_RTX_LENGTH (GET_CODE (x)); i++)
3287 {
3288 switch (*format_ptr++)
3289 {
3290 case 'e':
3291 mark_constants (XEXP (x, i));
3292 break;
3293
3294 case 'E':
3295 if (XVEC (x, i) != 0)
3296 {
3297 int j;
3298
3299 for (j = 0; j < XVECLEN (x, i); j++)
3300 mark_constants (XVECEXP (x, i, j));
3301 }
3302 break;
3303
3304 case 'S':
3305 case 's':
3306 case '0':
3307 case 'i':
3308 case 'w':
3309 case 'n':
3310 case 'u':
3311 case 'B':
3312 break;
3313
3314 default:
3315 abort ();
3316 }
3317 }
3318 }
3319
3320 /* Given a SYMBOL_REF CURRENT_RTX, mark it and all constants it refers
3321 to as used. Emit referenced deferred strings. This function can
3322 be used with for_each_rtx to mark all SYMBOL_REFs in an rtx. */
3323
3324 static int
3325 mark_constant (rtx *current_rtx, void *data ATTRIBUTE_UNUSED)
3326 {
3327 rtx x = *current_rtx;
3328
3329 if (x == NULL_RTX)
3330 return 0;
3331
3332 else if (GET_CODE (x) == SYMBOL_REF)
3333 {
3334 if (CONSTANT_POOL_ADDRESS_P (x))
3335 {
3336 struct pool_constant *pool = find_pool_constant (cfun, x);
3337 if (pool->mark == 0)
3338 {
3339 pool->mark = 1;
3340 for_each_rtx (&(pool->constant), &mark_constant, NULL);
3341 }
3342 else
3343 return -1;
3344 }
3345 else if (TREE_CONSTANT_POOL_ADDRESS_P (x))
3346 {
3347 tree exp = SYMBOL_REF_DECL (x);
3348 if (!TREE_ASM_WRITTEN (exp))
3349 {
3350 n_deferred_constants--;
3351 output_constant_def_contents (x);
3352 }
3353 }
3354 }
3355 return 0;
3356 }
3357 \f
3358 /* Find all the constants whose addresses are referenced inside of EXP,
3359 and make sure assembler code with a label has been output for each one.
3360 Indicate whether an ADDR_EXPR has been encountered. */
3361
3362 static int
3363 output_addressed_constants (tree exp)
3364 {
3365 int reloc = 0, reloc2;
3366 tree tem;
3367
3368 /* Give the front-end a chance to convert VALUE to something that
3369 looks more like a constant to the back-end. */
3370 exp = (*lang_hooks.expand_constant) (exp);
3371
3372 switch (TREE_CODE (exp))
3373 {
3374 case ADDR_EXPR:
3375 case FDESC_EXPR:
3376 /* Go inside any operations that get_inner_reference can handle and see
3377 if what's inside is a constant: no need to do anything here for
3378 addresses of variables or functions. */
3379 for (tem = TREE_OPERAND (exp, 0); handled_component_p (tem);
3380 tem = TREE_OPERAND (tem, 0))
3381 ;
3382
3383 if (TREE_CODE_CLASS (TREE_CODE (tem)) == 'c'
3384 || TREE_CODE (tem) == CONSTRUCTOR)
3385 output_constant_def (tem, 0);
3386
3387 if (TREE_PUBLIC (tem))
3388 reloc |= 2;
3389 else
3390 reloc |= 1;
3391 break;
3392
3393 case PLUS_EXPR:
3394 reloc = output_addressed_constants (TREE_OPERAND (exp, 0));
3395 reloc |= output_addressed_constants (TREE_OPERAND (exp, 1));
3396 break;
3397
3398 case MINUS_EXPR:
3399 reloc = output_addressed_constants (TREE_OPERAND (exp, 0));
3400 reloc2 = output_addressed_constants (TREE_OPERAND (exp, 1));
3401 /* The difference of two local labels is computable at link time. */
3402 if (reloc == 1 && reloc2 == 1)
3403 reloc = 0;
3404 else
3405 reloc |= reloc2;
3406 break;
3407
3408 case NOP_EXPR:
3409 case CONVERT_EXPR:
3410 case NON_LVALUE_EXPR:
3411 reloc = output_addressed_constants (TREE_OPERAND (exp, 0));
3412 break;
3413
3414 case CONSTRUCTOR:
3415 for (tem = CONSTRUCTOR_ELTS (exp); tem; tem = TREE_CHAIN (tem))
3416 if (TREE_VALUE (tem) != 0)
3417 reloc |= output_addressed_constants (TREE_VALUE (tem));
3418
3419 break;
3420
3421 default:
3422 break;
3423 }
3424 return reloc;
3425 }
3426 \f
3427 /* Return nonzero if VALUE is a valid constant-valued expression
3428 for use in initializing a static variable; one that can be an
3429 element of a "constant" initializer.
3430
3431 Return null_pointer_node if the value is absolute;
3432 if it is relocatable, return the variable that determines the relocation.
3433 We assume that VALUE has been folded as much as possible;
3434 therefore, we do not need to check for such things as
3435 arithmetic-combinations of integers. */
3436
3437 tree
3438 initializer_constant_valid_p (tree value, tree endtype)
3439 {
3440 /* Give the front-end a chance to convert VALUE to something that
3441 looks more like a constant to the back-end. */
3442 value = (*lang_hooks.expand_constant) (value);
3443
3444 switch (TREE_CODE (value))
3445 {
3446 case CONSTRUCTOR:
3447 if ((TREE_CODE (TREE_TYPE (value)) == UNION_TYPE
3448 || TREE_CODE (TREE_TYPE (value)) == RECORD_TYPE)
3449 && TREE_CONSTANT (value)
3450 && CONSTRUCTOR_ELTS (value))
3451 return
3452 initializer_constant_valid_p (TREE_VALUE (CONSTRUCTOR_ELTS (value)),
3453 endtype);
3454
3455 return TREE_STATIC (value) ? null_pointer_node : 0;
3456
3457 case INTEGER_CST:
3458 case VECTOR_CST:
3459 case REAL_CST:
3460 case STRING_CST:
3461 case COMPLEX_CST:
3462 return null_pointer_node;
3463
3464 case ADDR_EXPR:
3465 case FDESC_EXPR:
3466 return staticp (TREE_OPERAND (value, 0)) ? TREE_OPERAND (value, 0) : 0;
3467
3468 case VIEW_CONVERT_EXPR:
3469 case NON_LVALUE_EXPR:
3470 return initializer_constant_valid_p (TREE_OPERAND (value, 0), endtype);
3471
3472 case CONVERT_EXPR:
3473 case NOP_EXPR:
3474 /* Allow conversions between pointer types. */
3475 if (POINTER_TYPE_P (TREE_TYPE (value))
3476 && POINTER_TYPE_P (TREE_TYPE (TREE_OPERAND (value, 0))))
3477 return initializer_constant_valid_p (TREE_OPERAND (value, 0), endtype);
3478
3479 /* Allow conversions between real types. */
3480 if (FLOAT_TYPE_P (TREE_TYPE (value))
3481 && FLOAT_TYPE_P (TREE_TYPE (TREE_OPERAND (value, 0))))
3482 return initializer_constant_valid_p (TREE_OPERAND (value, 0), endtype);
3483
3484 /* Allow length-preserving conversions between integer types. */
3485 if (INTEGRAL_TYPE_P (TREE_TYPE (value))
3486 && INTEGRAL_TYPE_P (TREE_TYPE (TREE_OPERAND (value, 0)))
3487 && (TYPE_PRECISION (TREE_TYPE (value))
3488 == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (value, 0)))))
3489 return initializer_constant_valid_p (TREE_OPERAND (value, 0), endtype);
3490
3491 /* Allow conversions between other integer types only if
3492 explicit value. */
3493 if (INTEGRAL_TYPE_P (TREE_TYPE (value))
3494 && INTEGRAL_TYPE_P (TREE_TYPE (TREE_OPERAND (value, 0))))
3495 {
3496 tree inner = initializer_constant_valid_p (TREE_OPERAND (value, 0),
3497 endtype);
3498 if (inner == null_pointer_node)
3499 return null_pointer_node;
3500 break;
3501 }
3502
3503 /* Allow (int) &foo provided int is as wide as a pointer. */
3504 if (INTEGRAL_TYPE_P (TREE_TYPE (value))
3505 && POINTER_TYPE_P (TREE_TYPE (TREE_OPERAND (value, 0)))
3506 && (TYPE_PRECISION (TREE_TYPE (value))
3507 >= TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (value, 0)))))
3508 return initializer_constant_valid_p (TREE_OPERAND (value, 0),
3509 endtype);
3510
3511 /* Likewise conversions from int to pointers, but also allow
3512 conversions from 0. */
3513 if (POINTER_TYPE_P (TREE_TYPE (value))
3514 && INTEGRAL_TYPE_P (TREE_TYPE (TREE_OPERAND (value, 0))))
3515 {
3516 if (integer_zerop (TREE_OPERAND (value, 0)))
3517 return null_pointer_node;
3518 else if (TYPE_PRECISION (TREE_TYPE (value))
3519 <= TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (value, 0))))
3520 return initializer_constant_valid_p (TREE_OPERAND (value, 0),
3521 endtype);
3522 }
3523
3524 /* Allow conversions to union types if the value inside is okay. */
3525 if (TREE_CODE (TREE_TYPE (value)) == UNION_TYPE)
3526 return initializer_constant_valid_p (TREE_OPERAND (value, 0),
3527 endtype);
3528 break;
3529
3530 case PLUS_EXPR:
3531 if (! INTEGRAL_TYPE_P (endtype)
3532 || TYPE_PRECISION (endtype) >= POINTER_SIZE)
3533 {
3534 tree valid0 = initializer_constant_valid_p (TREE_OPERAND (value, 0),
3535 endtype);
3536 tree valid1 = initializer_constant_valid_p (TREE_OPERAND (value, 1),
3537 endtype);
3538 /* If either term is absolute, use the other terms relocation. */
3539 if (valid0 == null_pointer_node)
3540 return valid1;
3541 if (valid1 == null_pointer_node)
3542 return valid0;
3543 }
3544 break;
3545
3546 case MINUS_EXPR:
3547 if (! INTEGRAL_TYPE_P (endtype)
3548 || TYPE_PRECISION (endtype) >= POINTER_SIZE)
3549 {
3550 tree valid0 = initializer_constant_valid_p (TREE_OPERAND (value, 0),
3551 endtype);
3552 tree valid1 = initializer_constant_valid_p (TREE_OPERAND (value, 1),
3553 endtype);
3554 /* Win if second argument is absolute. */
3555 if (valid1 == null_pointer_node)
3556 return valid0;
3557 /* Win if both arguments have the same relocation.
3558 Then the value is absolute. */
3559 if (valid0 == valid1 && valid0 != 0)
3560 return null_pointer_node;
3561
3562 /* Since GCC guarantees that string constants are unique in the
3563 generated code, a subtraction between two copies of the same
3564 constant string is absolute. */
3565 if (valid0 && TREE_CODE (valid0) == STRING_CST &&
3566 valid1 && TREE_CODE (valid1) == STRING_CST &&
3567 TREE_STRING_POINTER (valid0) == TREE_STRING_POINTER (valid1))
3568 return null_pointer_node;
3569 }
3570
3571 /* Support differences between labels. */
3572 if (INTEGRAL_TYPE_P (endtype))
3573 {
3574 tree op0, op1;
3575 op0 = TREE_OPERAND (value, 0);
3576 op1 = TREE_OPERAND (value, 1);
3577
3578 /* Like STRIP_NOPS except allow the operand mode to widen.
3579 This works around a feature of fold that simplifies
3580 (int)(p1 - p2) to ((int)p1 - (int)p2) under the theory
3581 that the narrower operation is cheaper. */
3582
3583 while (TREE_CODE (op0) == NOP_EXPR
3584 || TREE_CODE (op0) == CONVERT_EXPR
3585 || TREE_CODE (op0) == NON_LVALUE_EXPR)
3586 {
3587 tree inner = TREE_OPERAND (op0, 0);
3588 if (inner == error_mark_node
3589 || ! INTEGRAL_MODE_P (TYPE_MODE (TREE_TYPE (inner)))
3590 || (GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op0)))
3591 > GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (inner)))))
3592 break;
3593 op0 = inner;
3594 }
3595
3596 while (TREE_CODE (op1) == NOP_EXPR
3597 || TREE_CODE (op1) == CONVERT_EXPR
3598 || TREE_CODE (op1) == NON_LVALUE_EXPR)
3599 {
3600 tree inner = TREE_OPERAND (op1, 0);
3601 if (inner == error_mark_node
3602 || ! INTEGRAL_MODE_P (TYPE_MODE (TREE_TYPE (inner)))
3603 || (GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op1)))
3604 > GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (inner)))))
3605 break;
3606 op1 = inner;
3607 }
3608
3609 if (TREE_CODE (op0) == ADDR_EXPR
3610 && TREE_CODE (TREE_OPERAND (op0, 0)) == LABEL_DECL
3611 && TREE_CODE (op1) == ADDR_EXPR
3612 && TREE_CODE (TREE_OPERAND (op1, 0)) == LABEL_DECL)
3613 return null_pointer_node;
3614 }
3615 break;
3616
3617 default:
3618 break;
3619 }
3620
3621 return 0;
3622 }
3623 \f
3624 /* Output assembler code for constant EXP to FILE, with no label.
3625 This includes the pseudo-op such as ".int" or ".byte", and a newline.
3626 Assumes output_addressed_constants has been done on EXP already.
3627
3628 Generate exactly SIZE bytes of assembler data, padding at the end
3629 with zeros if necessary. SIZE must always be specified.
3630
3631 SIZE is important for structure constructors,
3632 since trailing members may have been omitted from the constructor.
3633 It is also important for initialization of arrays from string constants
3634 since the full length of the string constant might not be wanted.
3635 It is also needed for initialization of unions, where the initializer's
3636 type is just one member, and that may not be as long as the union.
3637
3638 There a case in which we would fail to output exactly SIZE bytes:
3639 for a structure constructor that wants to produce more than SIZE bytes.
3640 But such constructors will never be generated for any possible input.
3641
3642 ALIGN is the alignment of the data in bits. */
3643
3644 void
3645 output_constant (tree exp, unsigned HOST_WIDE_INT size, unsigned int align)
3646 {
3647 enum tree_code code;
3648 unsigned HOST_WIDE_INT thissize;
3649
3650 /* Some front-ends use constants other than the standard language-independent
3651 varieties, but which may still be output directly. Give the front-end a
3652 chance to convert EXP to a language-independent representation. */
3653 exp = (*lang_hooks.expand_constant) (exp);
3654
3655 if (size == 0 || flag_syntax_only)
3656 return;
3657
3658 /* Eliminate any conversions since we'll be outputting the underlying
3659 constant. */
3660 while (TREE_CODE (exp) == NOP_EXPR || TREE_CODE (exp) == CONVERT_EXPR
3661 || TREE_CODE (exp) == NON_LVALUE_EXPR
3662 || TREE_CODE (exp) == VIEW_CONVERT_EXPR)
3663 exp = TREE_OPERAND (exp, 0);
3664
3665 code = TREE_CODE (TREE_TYPE (exp));
3666 thissize = int_size_in_bytes (TREE_TYPE (exp));
3667
3668 /* Allow a constructor with no elements for any data type.
3669 This means to fill the space with zeros. */
3670 if (TREE_CODE (exp) == CONSTRUCTOR && CONSTRUCTOR_ELTS (exp) == 0)
3671 {
3672 assemble_zeros (size);
3673 return;
3674 }
3675
3676 if (TREE_CODE (exp) == FDESC_EXPR)
3677 {
3678 #ifdef ASM_OUTPUT_FDESC
3679 HOST_WIDE_INT part = tree_low_cst (TREE_OPERAND (exp, 1), 0);
3680 tree decl = TREE_OPERAND (exp, 0);
3681 ASM_OUTPUT_FDESC (asm_out_file, decl, part);
3682 #else
3683 abort ();
3684 #endif
3685 return;
3686 }
3687
3688 /* Now output the underlying data. If we've handling the padding, return.
3689 Otherwise, break and ensure THISSIZE is the size written. */
3690 switch (code)
3691 {
3692 case CHAR_TYPE:
3693 case BOOLEAN_TYPE:
3694 case INTEGER_TYPE:
3695 case ENUMERAL_TYPE:
3696 case POINTER_TYPE:
3697 case REFERENCE_TYPE:
3698 case OFFSET_TYPE:
3699 if (! assemble_integer (expand_expr (exp, NULL_RTX, VOIDmode,
3700 EXPAND_INITIALIZER),
3701 size, align, 0))
3702 error ("initializer for integer value is too complicated");
3703 break;
3704
3705 case REAL_TYPE:
3706 if (TREE_CODE (exp) != REAL_CST)
3707 error ("initializer for floating value is not a floating constant");
3708
3709 assemble_real (TREE_REAL_CST (exp),
3710 mode_for_size (size * BITS_PER_UNIT, MODE_FLOAT, 0),
3711 align);
3712 break;
3713
3714 case COMPLEX_TYPE:
3715 output_constant (TREE_REALPART (exp), thissize / 2, align);
3716 output_constant (TREE_IMAGPART (exp), thissize / 2,
3717 min_align (align, BITS_PER_UNIT * (thissize / 2)));
3718 break;
3719
3720 case ARRAY_TYPE:
3721 case VECTOR_TYPE:
3722 if (TREE_CODE (exp) == CONSTRUCTOR)
3723 {
3724 output_constructor (exp, size, align);
3725 return;
3726 }
3727 else if (TREE_CODE (exp) == STRING_CST)
3728 {
3729 thissize = MIN ((unsigned HOST_WIDE_INT)TREE_STRING_LENGTH (exp),
3730 size);
3731 assemble_string (TREE_STRING_POINTER (exp), thissize);
3732 }
3733 else if (TREE_CODE (exp) == VECTOR_CST)
3734 {
3735 int elt_size;
3736 tree link;
3737 unsigned int nalign;
3738 enum machine_mode inner;
3739
3740 inner = GET_MODE_INNER (TYPE_MODE (TREE_TYPE (exp)));
3741 nalign = MIN (align, GET_MODE_ALIGNMENT (inner));
3742
3743 elt_size = GET_MODE_UNIT_SIZE (TYPE_MODE (TREE_TYPE (exp)));
3744
3745 link = TREE_VECTOR_CST_ELTS (exp);
3746 output_constant (TREE_VALUE (link), elt_size, align);
3747 while ((link = TREE_CHAIN (link)) != NULL)
3748 output_constant (TREE_VALUE (link), elt_size, nalign);
3749 }
3750 else
3751 abort ();
3752 break;
3753
3754 case RECORD_TYPE:
3755 case UNION_TYPE:
3756 if (TREE_CODE (exp) == CONSTRUCTOR)
3757 output_constructor (exp, size, align);
3758 else
3759 abort ();
3760 return;
3761
3762 case SET_TYPE:
3763 if (TREE_CODE (exp) == INTEGER_CST)
3764 assemble_integer (expand_expr (exp, NULL_RTX,
3765 VOIDmode, EXPAND_INITIALIZER),
3766 thissize, align, 1);
3767 else if (TREE_CODE (exp) == CONSTRUCTOR)
3768 {
3769 unsigned char *buffer = alloca (thissize);
3770 if (get_set_constructor_bytes (exp, buffer, thissize))
3771 abort ();
3772 assemble_string ((char *) buffer, thissize);
3773 }
3774 else
3775 error ("unknown set constructor type");
3776 return;
3777
3778 case ERROR_MARK:
3779 return;
3780
3781 default:
3782 abort ();
3783 }
3784
3785 if (size > thissize)
3786 assemble_zeros (size - thissize);
3787 }
3788
3789 \f
3790 /* Subroutine of output_constructor, used for computing the size of
3791 arrays of unspecified length. VAL must be a CONSTRUCTOR of an array
3792 type with an unspecified upper bound. */
3793
3794 static unsigned HOST_WIDE_INT
3795 array_size_for_constructor (tree val)
3796 {
3797 tree max_index, i;
3798
3799 /* This code used to attempt to handle string constants that are not
3800 arrays of single-bytes, but nothing else does, so there's no point in
3801 doing it here. */
3802 if (TREE_CODE (val) == STRING_CST)
3803 return TREE_STRING_LENGTH (val);
3804
3805 max_index = NULL_TREE;
3806 for (i = CONSTRUCTOR_ELTS (val); i; i = TREE_CHAIN (i))
3807 {
3808 tree index = TREE_PURPOSE (i);
3809
3810 if (TREE_CODE (index) == RANGE_EXPR)
3811 index = TREE_OPERAND (index, 1);
3812 if (max_index == NULL_TREE || tree_int_cst_lt (max_index, index))
3813 max_index = index;
3814 }
3815
3816 if (max_index == NULL_TREE)
3817 return 0;
3818
3819 /* Compute the total number of array elements. */
3820 i = size_binop (MINUS_EXPR, convert (sizetype, max_index),
3821 convert (sizetype,
3822 TYPE_MIN_VALUE (TYPE_DOMAIN (TREE_TYPE (val)))));
3823 i = size_binop (PLUS_EXPR, i, convert (sizetype, integer_one_node));
3824
3825 /* Multiply by the array element unit size to find number of bytes. */
3826 i = size_binop (MULT_EXPR, i, TYPE_SIZE_UNIT (TREE_TYPE (TREE_TYPE (val))));
3827
3828 return tree_low_cst (i, 1);
3829 }
3830
3831 /* Subroutine of output_constant, used for CONSTRUCTORs (aggregate constants).
3832 Generate at least SIZE bytes, padding if necessary. */
3833
3834 static void
3835 output_constructor (tree exp, unsigned HOST_WIDE_INT size,
3836 unsigned int align)
3837 {
3838 tree type = TREE_TYPE (exp);
3839 tree link, field = 0;
3840 tree min_index = 0;
3841 /* Number of bytes output or skipped so far.
3842 In other words, current position within the constructor. */
3843 HOST_WIDE_INT total_bytes = 0;
3844 /* Nonzero means BYTE contains part of a byte, to be output. */
3845 int byte_buffer_in_use = 0;
3846 int byte = 0;
3847
3848 if (HOST_BITS_PER_WIDE_INT < BITS_PER_UNIT)
3849 abort ();
3850
3851 if (TREE_CODE (type) == RECORD_TYPE)
3852 field = TYPE_FIELDS (type);
3853
3854 if (TREE_CODE (type) == ARRAY_TYPE
3855 && TYPE_DOMAIN (type) != 0)
3856 min_index = TYPE_MIN_VALUE (TYPE_DOMAIN (type));
3857
3858 /* As LINK goes through the elements of the constant,
3859 FIELD goes through the structure fields, if the constant is a structure.
3860 if the constant is a union, then we override this,
3861 by getting the field from the TREE_LIST element.
3862 But the constant could also be an array. Then FIELD is zero.
3863
3864 There is always a maximum of one element in the chain LINK for unions
3865 (even if the initializer in a source program incorrectly contains
3866 more one). */
3867 for (link = CONSTRUCTOR_ELTS (exp);
3868 link;
3869 link = TREE_CHAIN (link),
3870 field = field ? TREE_CHAIN (field) : 0)
3871 {
3872 tree val = TREE_VALUE (link);
3873 tree index = 0;
3874
3875 /* The element in a union constructor specifies the proper field
3876 or index. */
3877 if ((TREE_CODE (type) == RECORD_TYPE || TREE_CODE (type) == UNION_TYPE
3878 || TREE_CODE (type) == QUAL_UNION_TYPE)
3879 && TREE_PURPOSE (link) != 0)
3880 field = TREE_PURPOSE (link);
3881
3882 else if (TREE_CODE (type) == ARRAY_TYPE)
3883 index = TREE_PURPOSE (link);
3884
3885 /* Eliminate the marker that makes a cast not be an lvalue. */
3886 if (val != 0)
3887 STRIP_NOPS (val);
3888
3889 if (index && TREE_CODE (index) == RANGE_EXPR)
3890 {
3891 unsigned HOST_WIDE_INT fieldsize
3892 = int_size_in_bytes (TREE_TYPE (type));
3893 HOST_WIDE_INT lo_index = tree_low_cst (TREE_OPERAND (index, 0), 0);
3894 HOST_WIDE_INT hi_index = tree_low_cst (TREE_OPERAND (index, 1), 0);
3895 HOST_WIDE_INT index;
3896 unsigned int align2 = min_align (align, fieldsize * BITS_PER_UNIT);
3897
3898 for (index = lo_index; index <= hi_index; index++)
3899 {
3900 /* Output the element's initial value. */
3901 if (val == 0)
3902 assemble_zeros (fieldsize);
3903 else
3904 output_constant (val, fieldsize, align2);
3905
3906 /* Count its size. */
3907 total_bytes += fieldsize;
3908 }
3909 }
3910 else if (field == 0 || !DECL_BIT_FIELD (field))
3911 {
3912 /* An element that is not a bit-field. */
3913
3914 unsigned HOST_WIDE_INT fieldsize;
3915 /* Since this structure is static,
3916 we know the positions are constant. */
3917 HOST_WIDE_INT pos = field ? int_byte_position (field) : 0;
3918 unsigned int align2;
3919
3920 if (index != 0)
3921 pos = (tree_low_cst (TYPE_SIZE_UNIT (TREE_TYPE (val)), 1)
3922 * (tree_low_cst (index, 0) - tree_low_cst (min_index, 0)));
3923
3924 /* Output any buffered-up bit-fields preceding this element. */
3925 if (byte_buffer_in_use)
3926 {
3927 assemble_integer (GEN_INT (byte), 1, BITS_PER_UNIT, 1);
3928 total_bytes++;
3929 byte_buffer_in_use = 0;
3930 }
3931
3932 /* Advance to offset of this element.
3933 Note no alignment needed in an array, since that is guaranteed
3934 if each element has the proper size. */
3935 if ((field != 0 || index != 0) && pos != total_bytes)
3936 {
3937 assemble_zeros (pos - total_bytes);
3938 total_bytes = pos;
3939 }
3940
3941 /* Find the alignment of this element. */
3942 align2 = min_align (align, BITS_PER_UNIT * pos);
3943
3944 /* Determine size this element should occupy. */
3945 if (field)
3946 {
3947 fieldsize = 0;
3948
3949 /* If this is an array with an unspecified upper bound,
3950 the initializer determines the size. */
3951 /* ??? This ought to only checked if DECL_SIZE_UNIT is NULL,
3952 but we cannot do this until the deprecated support for
3953 initializing zero-length array members is removed. */
3954 if (TREE_CODE (TREE_TYPE (field)) == ARRAY_TYPE
3955 && TYPE_DOMAIN (TREE_TYPE (field))
3956 && ! TYPE_MAX_VALUE (TYPE_DOMAIN (TREE_TYPE (field))))
3957 {
3958 fieldsize = array_size_for_constructor (val);
3959 /* Given a non-empty initialization, this field had
3960 better be last. */
3961 if (fieldsize != 0 && TREE_CHAIN (field) != NULL_TREE)
3962 abort ();
3963 }
3964 else if (DECL_SIZE_UNIT (field))
3965 {
3966 /* ??? This can't be right. If the decl size overflows
3967 a host integer we will silently emit no data. */
3968 if (host_integerp (DECL_SIZE_UNIT (field), 1))
3969 fieldsize = tree_low_cst (DECL_SIZE_UNIT (field), 1);
3970 }
3971 }
3972 else
3973 fieldsize = int_size_in_bytes (TREE_TYPE (type));
3974
3975 /* Output the element's initial value. */
3976 if (val == 0)
3977 assemble_zeros (fieldsize);
3978 else
3979 output_constant (val, fieldsize, align2);
3980
3981 /* Count its size. */
3982 total_bytes += fieldsize;
3983 }
3984 else if (val != 0 && TREE_CODE (val) != INTEGER_CST)
3985 error ("invalid initial value for member `%s'",
3986 IDENTIFIER_POINTER (DECL_NAME (field)));
3987 else
3988 {
3989 /* Element that is a bit-field. */
3990
3991 HOST_WIDE_INT next_offset = int_bit_position (field);
3992 HOST_WIDE_INT end_offset
3993 = (next_offset + tree_low_cst (DECL_SIZE (field), 1));
3994
3995 if (val == 0)
3996 val = integer_zero_node;
3997
3998 /* If this field does not start in this (or, next) byte,
3999 skip some bytes. */
4000 if (next_offset / BITS_PER_UNIT != total_bytes)
4001 {
4002 /* Output remnant of any bit field in previous bytes. */
4003 if (byte_buffer_in_use)
4004 {
4005 assemble_integer (GEN_INT (byte), 1, BITS_PER_UNIT, 1);
4006 total_bytes++;
4007 byte_buffer_in_use = 0;
4008 }
4009
4010 /* If still not at proper byte, advance to there. */
4011 if (next_offset / BITS_PER_UNIT != total_bytes)
4012 {
4013 assemble_zeros (next_offset / BITS_PER_UNIT - total_bytes);
4014 total_bytes = next_offset / BITS_PER_UNIT;
4015 }
4016 }
4017
4018 if (! byte_buffer_in_use)
4019 byte = 0;
4020
4021 /* We must split the element into pieces that fall within
4022 separate bytes, and combine each byte with previous or
4023 following bit-fields. */
4024
4025 /* next_offset is the offset n fbits from the beginning of
4026 the structure to the next bit of this element to be processed.
4027 end_offset is the offset of the first bit past the end of
4028 this element. */
4029 while (next_offset < end_offset)
4030 {
4031 int this_time;
4032 int shift;
4033 HOST_WIDE_INT value;
4034 HOST_WIDE_INT next_byte = next_offset / BITS_PER_UNIT;
4035 HOST_WIDE_INT next_bit = next_offset % BITS_PER_UNIT;
4036
4037 /* Advance from byte to byte
4038 within this element when necessary. */
4039 while (next_byte != total_bytes)
4040 {
4041 assemble_integer (GEN_INT (byte), 1, BITS_PER_UNIT, 1);
4042 total_bytes++;
4043 byte = 0;
4044 }
4045
4046 /* Number of bits we can process at once
4047 (all part of the same byte). */
4048 this_time = MIN (end_offset - next_offset,
4049 BITS_PER_UNIT - next_bit);
4050 if (BYTES_BIG_ENDIAN)
4051 {
4052 /* On big-endian machine, take the most significant bits
4053 first (of the bits that are significant)
4054 and put them into bytes from the most significant end. */
4055 shift = end_offset - next_offset - this_time;
4056
4057 /* Don't try to take a bunch of bits that cross
4058 the word boundary in the INTEGER_CST. We can
4059 only select bits from the LOW or HIGH part
4060 not from both. */
4061 if (shift < HOST_BITS_PER_WIDE_INT
4062 && shift + this_time > HOST_BITS_PER_WIDE_INT)
4063 {
4064 this_time = shift + this_time - HOST_BITS_PER_WIDE_INT;
4065 shift = HOST_BITS_PER_WIDE_INT;
4066 }
4067
4068 /* Now get the bits from the appropriate constant word. */
4069 if (shift < HOST_BITS_PER_WIDE_INT)
4070 value = TREE_INT_CST_LOW (val);
4071 else if (shift < 2 * HOST_BITS_PER_WIDE_INT)
4072 {
4073 value = TREE_INT_CST_HIGH (val);
4074 shift -= HOST_BITS_PER_WIDE_INT;
4075 }
4076 else
4077 abort ();
4078
4079 /* Get the result. This works only when:
4080 1 <= this_time <= HOST_BITS_PER_WIDE_INT. */
4081 byte |= (((value >> shift)
4082 & (((HOST_WIDE_INT) 2 << (this_time - 1)) - 1))
4083 << (BITS_PER_UNIT - this_time - next_bit));
4084 }
4085 else
4086 {
4087 /* On little-endian machines,
4088 take first the least significant bits of the value
4089 and pack them starting at the least significant
4090 bits of the bytes. */
4091 shift = next_offset - int_bit_position (field);
4092
4093 /* Don't try to take a bunch of bits that cross
4094 the word boundary in the INTEGER_CST. We can
4095 only select bits from the LOW or HIGH part
4096 not from both. */
4097 if (shift < HOST_BITS_PER_WIDE_INT
4098 && shift + this_time > HOST_BITS_PER_WIDE_INT)
4099 this_time = (HOST_BITS_PER_WIDE_INT - shift);
4100
4101 /* Now get the bits from the appropriate constant word. */
4102 if (shift < HOST_BITS_PER_WIDE_INT)
4103 value = TREE_INT_CST_LOW (val);
4104 else if (shift < 2 * HOST_BITS_PER_WIDE_INT)
4105 {
4106 value = TREE_INT_CST_HIGH (val);
4107 shift -= HOST_BITS_PER_WIDE_INT;
4108 }
4109 else
4110 abort ();
4111
4112 /* Get the result. This works only when:
4113 1 <= this_time <= HOST_BITS_PER_WIDE_INT. */
4114 byte |= (((value >> shift)
4115 & (((HOST_WIDE_INT) 2 << (this_time - 1)) - 1))
4116 << next_bit);
4117 }
4118
4119 next_offset += this_time;
4120 byte_buffer_in_use = 1;
4121 }
4122 }
4123 }
4124
4125 if (byte_buffer_in_use)
4126 {
4127 assemble_integer (GEN_INT (byte), 1, BITS_PER_UNIT, 1);
4128 total_bytes++;
4129 }
4130
4131 if ((unsigned HOST_WIDE_INT)total_bytes < size)
4132 assemble_zeros (size - total_bytes);
4133 }
4134
4135 /* This TREE_LIST contains any weak symbol declarations waiting
4136 to be emitted. */
4137 static GTY(()) tree weak_decls;
4138
4139 /* Mark DECL as weak. */
4140
4141 static void
4142 mark_weak (tree decl)
4143 {
4144 DECL_WEAK (decl) = 1;
4145
4146 if (DECL_RTL_SET_P (decl)
4147 && GET_CODE (DECL_RTL (decl)) == MEM
4148 && XEXP (DECL_RTL (decl), 0)
4149 && GET_CODE (XEXP (DECL_RTL (decl), 0)) == SYMBOL_REF)
4150 SYMBOL_REF_WEAK (XEXP (DECL_RTL (decl), 0)) = 1;
4151 }
4152
4153 /* Merge weak status between NEWDECL and OLDDECL. */
4154
4155 void
4156 merge_weak (tree newdecl, tree olddecl)
4157 {
4158 if (DECL_WEAK (newdecl) == DECL_WEAK (olddecl))
4159 return;
4160
4161 if (DECL_WEAK (newdecl))
4162 {
4163 tree wd;
4164
4165 /* NEWDECL is weak, but OLDDECL is not. */
4166
4167 /* If we already output the OLDDECL, we're in trouble; we can't
4168 go back and make it weak. This error cannot caught in
4169 declare_weak because the NEWDECL and OLDDECL was not yet
4170 been merged; therefore, TREE_ASM_WRITTEN was not set. */
4171 if (TREE_ASM_WRITTEN (olddecl))
4172 error_with_decl (newdecl,
4173 "weak declaration of `%s' must precede definition");
4174
4175 /* If we've already generated rtl referencing OLDDECL, we may
4176 have done so in a way that will not function properly with
4177 a weak symbol. */
4178 else if (TREE_USED (olddecl)
4179 && TREE_SYMBOL_REFERENCED (DECL_ASSEMBLER_NAME (olddecl)))
4180 warning_with_decl (newdecl, "weak declaration of `%s' after first use results in unspecified behavior");
4181
4182 if (SUPPORTS_WEAK)
4183 {
4184 /* We put the NEWDECL on the weak_decls list at some point.
4185 Replace it with the OLDDECL. */
4186 for (wd = weak_decls; wd; wd = TREE_CHAIN (wd))
4187 if (TREE_VALUE (wd) == newdecl)
4188 {
4189 TREE_VALUE (wd) = olddecl;
4190 break;
4191 }
4192 /* We may not find the entry on the list. If NEWDECL is a
4193 weak alias, then we will have already called
4194 globalize_decl to remove the entry; in that case, we do
4195 not need to do anything. */
4196 }
4197
4198 /* Make the OLDDECL weak; it's OLDDECL that we'll be keeping. */
4199 mark_weak (olddecl);
4200 }
4201 else
4202 /* OLDDECL was weak, but NEWDECL was not explicitly marked as
4203 weak. Just update NEWDECL to indicate that it's weak too. */
4204 mark_weak (newdecl);
4205 }
4206
4207 /* Declare DECL to be a weak symbol. */
4208
4209 void
4210 declare_weak (tree decl)
4211 {
4212 if (! TREE_PUBLIC (decl))
4213 error_with_decl (decl, "weak declaration of `%s' must be public");
4214 else if (TREE_CODE (decl) == FUNCTION_DECL && TREE_ASM_WRITTEN (decl))
4215 error_with_decl (decl, "weak declaration of `%s' must precede definition");
4216 else if (SUPPORTS_WEAK)
4217 {
4218 if (! DECL_WEAK (decl))
4219 weak_decls = tree_cons (NULL, decl, weak_decls);
4220 }
4221 else
4222 warning_with_decl (decl, "weak declaration of `%s' not supported");
4223
4224 mark_weak (decl);
4225 }
4226
4227 /* Emit any pending weak declarations. */
4228
4229 void
4230 weak_finish (void)
4231 {
4232 tree t;
4233
4234 for (t = weak_decls; t; t = TREE_CHAIN (t))
4235 {
4236 tree decl = TREE_VALUE (t);
4237 #if defined (ASM_WEAKEN_DECL) || defined (ASM_WEAKEN_LABEL)
4238 const char *const name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
4239 #endif
4240
4241 if (! TREE_USED (decl))
4242 continue;
4243
4244 #ifdef ASM_WEAKEN_DECL
4245 ASM_WEAKEN_DECL (asm_out_file, decl, name, NULL);
4246 #else
4247 #ifdef ASM_WEAKEN_LABEL
4248 ASM_WEAKEN_LABEL (asm_out_file, name);
4249 #else
4250 #ifdef ASM_OUTPUT_WEAK_ALIAS
4251 warning ("only weak aliases are supported in this configuration");
4252 return;
4253 #endif
4254 #endif
4255 #endif
4256 }
4257 }
4258
4259 /* Emit the assembly bits to indicate that DECL is globally visible. */
4260
4261 static void
4262 globalize_decl (tree decl)
4263 {
4264 const char *name = XSTR (XEXP (DECL_RTL (decl), 0), 0);
4265
4266 #if defined (ASM_WEAKEN_LABEL) || defined (ASM_WEAKEN_DECL)
4267 if (DECL_WEAK (decl))
4268 {
4269 tree *p, t;
4270
4271 #ifdef ASM_WEAKEN_DECL
4272 ASM_WEAKEN_DECL (asm_out_file, decl, name, 0);
4273 #else
4274 ASM_WEAKEN_LABEL (asm_out_file, name);
4275 #endif
4276
4277 /* Remove this function from the pending weak list so that
4278 we do not emit multiple .weak directives for it. */
4279 for (p = &weak_decls; (t = *p) ; )
4280 {
4281 if (DECL_ASSEMBLER_NAME (decl) == DECL_ASSEMBLER_NAME (TREE_VALUE (t)))
4282 *p = TREE_CHAIN (t);
4283 else
4284 p = &TREE_CHAIN (t);
4285 }
4286 return;
4287 }
4288 #endif
4289
4290 (*targetm.asm_out.globalize_label) (asm_out_file, name);
4291 }
4292
4293 /* Emit an assembler directive to make the symbol for DECL an alias to
4294 the symbol for TARGET. */
4295
4296 void
4297 assemble_alias (tree decl, tree target ATTRIBUTE_UNUSED)
4298 {
4299 const char *name;
4300
4301 /* We must force creation of DECL_RTL for debug info generation, even though
4302 we don't use it here. */
4303 make_decl_rtl (decl, NULL);
4304
4305 name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
4306
4307 #ifdef ASM_OUTPUT_DEF
4308 /* Make name accessible from other files, if appropriate. */
4309
4310 if (TREE_PUBLIC (decl))
4311 {
4312 globalize_decl (decl);
4313 maybe_assemble_visibility (decl);
4314 }
4315
4316 #ifdef ASM_OUTPUT_DEF_FROM_DECLS
4317 ASM_OUTPUT_DEF_FROM_DECLS (asm_out_file, decl, target);
4318 #else
4319 ASM_OUTPUT_DEF (asm_out_file, name, IDENTIFIER_POINTER (target));
4320 #endif
4321 #else /* !ASM_OUTPUT_DEF */
4322 #if defined (ASM_OUTPUT_WEAK_ALIAS) || defined (ASM_WEAKEN_DECL)
4323 if (! DECL_WEAK (decl))
4324 warning ("only weak aliases are supported in this configuration");
4325
4326 #ifdef ASM_WEAKEN_DECL
4327 ASM_WEAKEN_DECL (asm_out_file, decl, name, IDENTIFIER_POINTER (target));
4328 #else
4329 ASM_OUTPUT_WEAK_ALIAS (asm_out_file, name, IDENTIFIER_POINTER (target));
4330 #endif
4331 #else
4332 warning ("alias definitions not supported in this configuration; ignored");
4333 #endif
4334 #endif
4335
4336 TREE_USED (decl) = 1;
4337 TREE_ASM_WRITTEN (decl) = 1;
4338 TREE_ASM_WRITTEN (DECL_ASSEMBLER_NAME (decl)) = 1;
4339 }
4340
4341 /* Emit an assembler directive to set symbol for DECL visibility to
4342 the visibility type VIS, which must not be VISIBILITY_DEFAULT. */
4343
4344 void
4345 default_assemble_visibility (tree decl, int vis)
4346 {
4347 static const char * const visibility_types[] = {
4348 NULL, "internal", "hidden", "protected"
4349 };
4350
4351 const char *name, *type;
4352
4353 name = (IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl)));
4354 type = visibility_types[vis];
4355
4356 #ifdef HAVE_GAS_HIDDEN
4357 fprintf (asm_out_file, "\t.%s\t", type);
4358 assemble_name (asm_out_file, name);
4359 fprintf (asm_out_file, "\n");
4360 #else
4361 warning ("visibility attribute not supported in this configuration; ignored");
4362 #endif
4363 }
4364
4365 /* A helper function to call assemble_visibility when needed for a decl. */
4366
4367 static void
4368 maybe_assemble_visibility (tree decl)
4369 {
4370 enum symbol_visibility vis = decl_visibility (decl);
4371
4372 if (vis != VISIBILITY_DEFAULT)
4373 (* targetm.asm_out.visibility) (decl, vis);
4374 }
4375
4376 /* Returns 1 if the target configuration supports defining public symbols
4377 so that one of them will be chosen at link time instead of generating a
4378 multiply-defined symbol error, whether through the use of weak symbols or
4379 a target-specific mechanism for having duplicates discarded. */
4380
4381 int
4382 supports_one_only (void)
4383 {
4384 if (SUPPORTS_ONE_ONLY)
4385 return 1;
4386 return SUPPORTS_WEAK;
4387 }
4388
4389 /* Set up DECL as a public symbol that can be defined in multiple
4390 translation units without generating a linker error. */
4391
4392 void
4393 make_decl_one_only (tree decl)
4394 {
4395 if (TREE_CODE (decl) != VAR_DECL && TREE_CODE (decl) != FUNCTION_DECL)
4396 abort ();
4397
4398 TREE_PUBLIC (decl) = 1;
4399
4400 if (TREE_CODE (decl) == VAR_DECL
4401 && (DECL_INITIAL (decl) == 0 || DECL_INITIAL (decl) == error_mark_node))
4402 DECL_COMMON (decl) = 1;
4403 else if (SUPPORTS_ONE_ONLY)
4404 {
4405 #ifdef MAKE_DECL_ONE_ONLY
4406 MAKE_DECL_ONE_ONLY (decl);
4407 #endif
4408 DECL_ONE_ONLY (decl) = 1;
4409 }
4410 else if (SUPPORTS_WEAK)
4411 DECL_WEAK (decl) = 1;
4412 else
4413 abort ();
4414 }
4415
4416 void
4417 init_varasm_once (void)
4418 {
4419 in_named_htab = htab_create_ggc (31, in_named_entry_hash,
4420 in_named_entry_eq, NULL);
4421 const_desc_htab = htab_create_ggc (1009, const_desc_hash,
4422 const_desc_eq, NULL);
4423
4424 const_alias_set = new_alias_set ();
4425 }
4426
4427 enum tls_model
4428 decl_tls_model (tree decl)
4429 {
4430 enum tls_model kind;
4431 tree attr = lookup_attribute ("tls_model", DECL_ATTRIBUTES (decl));
4432 bool is_local;
4433
4434 if (attr)
4435 {
4436 attr = TREE_VALUE (TREE_VALUE (attr));
4437 if (TREE_CODE (attr) != STRING_CST)
4438 abort ();
4439 if (!strcmp (TREE_STRING_POINTER (attr), "local-exec"))
4440 kind = TLS_MODEL_LOCAL_EXEC;
4441 else if (!strcmp (TREE_STRING_POINTER (attr), "initial-exec"))
4442 kind = TLS_MODEL_INITIAL_EXEC;
4443 else if (!strcmp (TREE_STRING_POINTER (attr), "local-dynamic"))
4444 kind = optimize ? TLS_MODEL_LOCAL_DYNAMIC : TLS_MODEL_GLOBAL_DYNAMIC;
4445 else if (!strcmp (TREE_STRING_POINTER (attr), "global-dynamic"))
4446 kind = TLS_MODEL_GLOBAL_DYNAMIC;
4447 else
4448 abort ();
4449 return kind;
4450 }
4451
4452 is_local = (*targetm.binds_local_p) (decl);
4453 if (!flag_pic)
4454 {
4455 if (is_local)
4456 kind = TLS_MODEL_LOCAL_EXEC;
4457 else
4458 kind = TLS_MODEL_INITIAL_EXEC;
4459 }
4460 /* Local dynamic is inefficient when we're not combining the
4461 parts of the address. */
4462 else if (optimize && is_local)
4463 kind = TLS_MODEL_LOCAL_DYNAMIC;
4464 else
4465 kind = TLS_MODEL_GLOBAL_DYNAMIC;
4466 if (kind < flag_tls_default)
4467 kind = flag_tls_default;
4468
4469 return kind;
4470 }
4471
4472 enum symbol_visibility
4473 decl_visibility (tree decl)
4474 {
4475 tree attr = lookup_attribute ("visibility", DECL_ATTRIBUTES (decl));
4476
4477 if (attr)
4478 {
4479 const char *which = TREE_STRING_POINTER (TREE_VALUE (TREE_VALUE (attr)));
4480
4481 if (strcmp (which, "default") == 0)
4482 return VISIBILITY_DEFAULT;
4483 if (strcmp (which, "internal") == 0)
4484 return VISIBILITY_INTERNAL;
4485 if (strcmp (which, "hidden") == 0)
4486 return VISIBILITY_HIDDEN;
4487 if (strcmp (which, "protected") == 0)
4488 return VISIBILITY_PROTECTED;
4489
4490 abort ();
4491 }
4492
4493 return VISIBILITY_DEFAULT;
4494 }
4495
4496 /* Select a set of attributes for section NAME based on the properties
4497 of DECL and whether or not RELOC indicates that DECL's initializer
4498 might contain runtime relocations.
4499
4500 We make the section read-only and executable for a function decl,
4501 read-only for a const data decl, and writable for a non-const data decl. */
4502
4503 unsigned int
4504 default_section_type_flags (tree decl, const char *name, int reloc)
4505 {
4506 return default_section_type_flags_1 (decl, name, reloc, flag_pic);
4507 }
4508
4509 unsigned int
4510 default_section_type_flags_1 (tree decl, const char *name, int reloc,
4511 int shlib)
4512 {
4513 unsigned int flags;
4514
4515 if (decl && TREE_CODE (decl) == FUNCTION_DECL)
4516 flags = SECTION_CODE;
4517 else if (decl && decl_readonly_section_1 (decl, reloc, shlib))
4518 flags = 0;
4519 else
4520 flags = SECTION_WRITE;
4521
4522 if (decl && DECL_ONE_ONLY (decl))
4523 flags |= SECTION_LINKONCE;
4524
4525 if (decl && TREE_CODE (decl) == VAR_DECL && DECL_THREAD_LOCAL (decl))
4526 flags |= SECTION_TLS | SECTION_WRITE;
4527
4528 if (strcmp (name, ".bss") == 0
4529 || strncmp (name, ".bss.", 5) == 0
4530 || strncmp (name, ".gnu.linkonce.b.", 16) == 0
4531 || strcmp (name, ".sbss") == 0
4532 || strncmp (name, ".sbss.", 6) == 0
4533 || strncmp (name, ".gnu.linkonce.sb.", 17) == 0
4534 || strcmp (name, ".tbss") == 0
4535 || strncmp (name, ".gnu.linkonce.tb.", 17) == 0)
4536 flags |= SECTION_BSS;
4537
4538 if (strcmp (name, ".tdata") == 0
4539 || strcmp (name, ".tbss") == 0
4540 || strncmp (name, ".gnu.linkonce.td.", 17) == 0
4541 || strncmp (name, ".gnu.linkonce.tb.", 17) == 0)
4542 flags |= SECTION_TLS;
4543
4544 /* These three sections have special ELF types. They are neither
4545 SHT_PROGBITS nor SHT_NOBITS, so when changing sections we don't
4546 want to print a section type (@progbits or @nobits). If someone
4547 is silly enough to emit code or TLS variables to one of these
4548 sections, then don't handle them specially. */
4549 if (!(flags & (SECTION_CODE | SECTION_BSS | SECTION_TLS))
4550 && (strcmp (name, ".init_array") == 0
4551 || strcmp (name, ".fini_array") == 0
4552 || strcmp (name, ".preinit_array") == 0))
4553 flags |= SECTION_NOTYPE;
4554
4555 return flags;
4556 }
4557
4558 /* Output assembly to switch to section NAME with attribute FLAGS.
4559 Four variants for common object file formats. */
4560
4561 void
4562 default_no_named_section (const char *name ATTRIBUTE_UNUSED,
4563 unsigned int flags ATTRIBUTE_UNUSED)
4564 {
4565 /* Some object formats don't support named sections at all. The
4566 front-end should already have flagged this as an error. */
4567 abort ();
4568 }
4569
4570 void
4571 default_elf_asm_named_section (const char *name, unsigned int flags)
4572 {
4573 char flagchars[10], *f = flagchars;
4574
4575 if (! named_section_first_declaration (name))
4576 {
4577 fprintf (asm_out_file, "\t.section\t%s\n", name);
4578 return;
4579 }
4580
4581 if (!(flags & SECTION_DEBUG))
4582 *f++ = 'a';
4583 if (flags & SECTION_WRITE)
4584 *f++ = 'w';
4585 if (flags & SECTION_CODE)
4586 *f++ = 'x';
4587 if (flags & SECTION_SMALL)
4588 *f++ = 's';
4589 if (flags & SECTION_MERGE)
4590 *f++ = 'M';
4591 if (flags & SECTION_STRINGS)
4592 *f++ = 'S';
4593 if (flags & SECTION_TLS)
4594 *f++ = 'T';
4595 *f = '\0';
4596
4597 fprintf (asm_out_file, "\t.section\t%s,\"%s\"", name, flagchars);
4598
4599 if (!(flags & SECTION_NOTYPE))
4600 {
4601 const char *type;
4602
4603 if (flags & SECTION_BSS)
4604 type = "nobits";
4605 else
4606 type = "progbits";
4607
4608 fprintf (asm_out_file, ",@%s", type);
4609
4610 if (flags & SECTION_ENTSIZE)
4611 fprintf (asm_out_file, ",%d", flags & SECTION_ENTSIZE);
4612 }
4613
4614 putc ('\n', asm_out_file);
4615 }
4616
4617 void
4618 default_coff_asm_named_section (const char *name, unsigned int flags)
4619 {
4620 char flagchars[8], *f = flagchars;
4621
4622 if (flags & SECTION_WRITE)
4623 *f++ = 'w';
4624 if (flags & SECTION_CODE)
4625 *f++ = 'x';
4626 *f = '\0';
4627
4628 fprintf (asm_out_file, "\t.section\t%s,\"%s\"\n", name, flagchars);
4629 }
4630
4631 void
4632 default_pe_asm_named_section (const char *name, unsigned int flags)
4633 {
4634 default_coff_asm_named_section (name, flags);
4635
4636 if (flags & SECTION_LINKONCE)
4637 {
4638 /* Functions may have been compiled at various levels of
4639 optimization so we can't use `same_size' here.
4640 Instead, have the linker pick one. */
4641 fprintf (asm_out_file, "\t.linkonce %s\n",
4642 (flags & SECTION_CODE ? "discard" : "same_size"));
4643 }
4644 }
4645 \f
4646 /* Used for vtable gc in GNU binutils. Record that the pointer at OFFSET
4647 from SYMBOL is used in all classes derived from SYMBOL. */
4648
4649 void
4650 assemble_vtable_entry (rtx symbol, HOST_WIDE_INT offset)
4651 {
4652 fputs ("\t.vtable_entry ", asm_out_file);
4653 output_addr_const (asm_out_file, symbol);
4654 fprintf (asm_out_file, ", " HOST_WIDE_INT_PRINT_DEC "\n", offset);
4655 }
4656
4657 /* Used for vtable gc in GNU binutils. Record the class hierarchy by noting
4658 that the vtable symbol CHILD is derived from the vtable symbol PARENT. */
4659
4660 void
4661 assemble_vtable_inherit (rtx child, rtx parent)
4662 {
4663 fputs ("\t.vtable_inherit ", asm_out_file);
4664 output_addr_const (asm_out_file, child);
4665 fputs (", ", asm_out_file);
4666 output_addr_const (asm_out_file, parent);
4667 fputc ('\n', asm_out_file);
4668 }
4669 \f
4670 /* The lame default section selector. */
4671
4672 void
4673 default_select_section (tree decl, int reloc,
4674 unsigned HOST_WIDE_INT align ATTRIBUTE_UNUSED)
4675 {
4676 bool readonly = false;
4677
4678 if (DECL_P (decl))
4679 {
4680 if (decl_readonly_section (decl, reloc))
4681 readonly = true;
4682 }
4683 else if (TREE_CODE (decl) == CONSTRUCTOR)
4684 {
4685 if (! ((flag_pic && reloc)
4686 || !TREE_READONLY (decl)
4687 || TREE_SIDE_EFFECTS (decl)
4688 || !TREE_CONSTANT (decl)))
4689 readonly = true;
4690 }
4691 else if (TREE_CODE (decl) == STRING_CST)
4692 readonly = !flag_writable_strings;
4693 else if (! (flag_pic && reloc))
4694 readonly = true;
4695
4696 if (readonly)
4697 readonly_data_section ();
4698 else
4699 data_section ();
4700 }
4701
4702 /* A helper function for default_elf_select_section and
4703 default_elf_unique_section. Categorizes the DECL. */
4704
4705 enum section_category
4706 {
4707 SECCAT_TEXT,
4708
4709 SECCAT_RODATA,
4710 SECCAT_RODATA_MERGE_STR,
4711 SECCAT_RODATA_MERGE_STR_INIT,
4712 SECCAT_RODATA_MERGE_CONST,
4713 SECCAT_SRODATA,
4714
4715 SECCAT_DATA,
4716
4717 /* To optimize loading of shared programs, define following subsections
4718 of data section:
4719 _REL Contains data that has relocations, so they get grouped
4720 together and dynamic linker will visit fewer pages in memory.
4721 _RO Contains data that is otherwise read-only. This is useful
4722 with prelinking as most relocations won't be dynamically
4723 linked and thus stay read only.
4724 _LOCAL Marks data containing relocations only to local objects.
4725 These relocations will get fully resolved by prelinking. */
4726 SECCAT_DATA_REL,
4727 SECCAT_DATA_REL_LOCAL,
4728 SECCAT_DATA_REL_RO,
4729 SECCAT_DATA_REL_RO_LOCAL,
4730
4731 SECCAT_SDATA,
4732 SECCAT_TDATA,
4733
4734 SECCAT_BSS,
4735 SECCAT_SBSS,
4736 SECCAT_TBSS
4737 };
4738
4739 static enum section_category
4740 categorize_decl_for_section (tree, int, int);
4741
4742 static enum section_category
4743 categorize_decl_for_section (tree decl, int reloc, int shlib)
4744 {
4745 enum section_category ret;
4746
4747 if (TREE_CODE (decl) == FUNCTION_DECL)
4748 return SECCAT_TEXT;
4749 else if (TREE_CODE (decl) == STRING_CST)
4750 {
4751 if (flag_writable_strings)
4752 return SECCAT_DATA;
4753 else
4754 return SECCAT_RODATA_MERGE_STR;
4755 }
4756 else if (TREE_CODE (decl) == VAR_DECL)
4757 {
4758 if (DECL_INITIAL (decl) == NULL
4759 || DECL_INITIAL (decl) == error_mark_node)
4760 ret = SECCAT_BSS;
4761 else if (! TREE_READONLY (decl)
4762 || TREE_SIDE_EFFECTS (decl)
4763 || ! TREE_CONSTANT (DECL_INITIAL (decl)))
4764 {
4765 if (shlib && (reloc & 2))
4766 ret = SECCAT_DATA_REL;
4767 else if (shlib && reloc)
4768 ret = SECCAT_DATA_REL_LOCAL;
4769 else
4770 ret = SECCAT_DATA;
4771 }
4772 else if (shlib && (reloc & 2))
4773 ret = SECCAT_DATA_REL_RO;
4774 else if (shlib && reloc)
4775 ret = SECCAT_DATA_REL_RO_LOCAL;
4776 else if (reloc || flag_merge_constants < 2)
4777 /* C and C++ don't allow different variables to share the same
4778 location. -fmerge-all-constants allows even that (at the
4779 expense of not conforming). */
4780 ret = SECCAT_RODATA;
4781 else if (TREE_CODE (DECL_INITIAL (decl)) == STRING_CST)
4782 ret = SECCAT_RODATA_MERGE_STR_INIT;
4783 else
4784 ret = SECCAT_RODATA_MERGE_CONST;
4785 }
4786 else if (TREE_CODE (decl) == CONSTRUCTOR)
4787 {
4788 if ((shlib && reloc)
4789 || TREE_SIDE_EFFECTS (decl)
4790 || ! TREE_CONSTANT (decl))
4791 ret = SECCAT_DATA;
4792 else
4793 ret = SECCAT_RODATA;
4794 }
4795 else
4796 ret = SECCAT_RODATA;
4797
4798 /* There are no read-only thread-local sections. */
4799 if (TREE_CODE (decl) == VAR_DECL && DECL_THREAD_LOCAL (decl))
4800 {
4801 if (ret == SECCAT_BSS)
4802 ret = SECCAT_TBSS;
4803 else
4804 ret = SECCAT_TDATA;
4805 }
4806
4807 /* If the target uses small data sections, select it. */
4808 else if ((*targetm.in_small_data_p) (decl))
4809 {
4810 if (ret == SECCAT_BSS)
4811 ret = SECCAT_SBSS;
4812 else if (targetm.have_srodata_section && ret == SECCAT_RODATA)
4813 ret = SECCAT_SRODATA;
4814 else
4815 ret = SECCAT_SDATA;
4816 }
4817
4818 return ret;
4819 }
4820
4821 bool
4822 decl_readonly_section (tree decl, int reloc)
4823 {
4824 return decl_readonly_section_1 (decl, reloc, flag_pic);
4825 }
4826
4827 bool
4828 decl_readonly_section_1 (tree decl, int reloc, int shlib)
4829 {
4830 switch (categorize_decl_for_section (decl, reloc, shlib))
4831 {
4832 case SECCAT_RODATA:
4833 case SECCAT_RODATA_MERGE_STR:
4834 case SECCAT_RODATA_MERGE_STR_INIT:
4835 case SECCAT_RODATA_MERGE_CONST:
4836 case SECCAT_SRODATA:
4837 return true;
4838 break;
4839 default:
4840 return false;
4841 break;
4842 }
4843 }
4844
4845 /* Select a section based on the above categorization. */
4846
4847 void
4848 default_elf_select_section (tree decl, int reloc,
4849 unsigned HOST_WIDE_INT align)
4850 {
4851 default_elf_select_section_1 (decl, reloc, align, flag_pic);
4852 }
4853
4854 void
4855 default_elf_select_section_1 (tree decl, int reloc,
4856 unsigned HOST_WIDE_INT align, int shlib)
4857 {
4858 switch (categorize_decl_for_section (decl, reloc, shlib))
4859 {
4860 case SECCAT_TEXT:
4861 /* We're not supposed to be called on FUNCTION_DECLs. */
4862 abort ();
4863 case SECCAT_RODATA:
4864 readonly_data_section ();
4865 break;
4866 case SECCAT_RODATA_MERGE_STR:
4867 mergeable_string_section (decl, align, 0);
4868 break;
4869 case SECCAT_RODATA_MERGE_STR_INIT:
4870 mergeable_string_section (DECL_INITIAL (decl), align, 0);
4871 break;
4872 case SECCAT_RODATA_MERGE_CONST:
4873 mergeable_constant_section (DECL_MODE (decl), align, 0);
4874 break;
4875 case SECCAT_SRODATA:
4876 named_section (NULL_TREE, ".sdata2", reloc);
4877 break;
4878 case SECCAT_DATA:
4879 data_section ();
4880 break;
4881 case SECCAT_DATA_REL:
4882 named_section (NULL_TREE, ".data.rel", reloc);
4883 break;
4884 case SECCAT_DATA_REL_LOCAL:
4885 named_section (NULL_TREE, ".data.rel.local", reloc);
4886 break;
4887 case SECCAT_DATA_REL_RO:
4888 named_section (NULL_TREE, ".data.rel.ro", reloc);
4889 break;
4890 case SECCAT_DATA_REL_RO_LOCAL:
4891 named_section (NULL_TREE, ".data.rel.ro.local", reloc);
4892 break;
4893 case SECCAT_SDATA:
4894 named_section (NULL_TREE, ".sdata", reloc);
4895 break;
4896 case SECCAT_TDATA:
4897 named_section (NULL_TREE, ".tdata", reloc);
4898 break;
4899 case SECCAT_BSS:
4900 #ifdef BSS_SECTION_ASM_OP
4901 bss_section ();
4902 #else
4903 named_section (NULL_TREE, ".bss", reloc);
4904 #endif
4905 break;
4906 case SECCAT_SBSS:
4907 named_section (NULL_TREE, ".sbss", reloc);
4908 break;
4909 case SECCAT_TBSS:
4910 named_section (NULL_TREE, ".tbss", reloc);
4911 break;
4912 default:
4913 abort ();
4914 }
4915 }
4916
4917 /* Construct a unique section name based on the decl name and the
4918 categorization performed above. */
4919
4920 void
4921 default_unique_section (tree decl, int reloc)
4922 {
4923 default_unique_section_1 (decl, reloc, flag_pic);
4924 }
4925
4926 void
4927 default_unique_section_1 (tree decl, int reloc, int shlib)
4928 {
4929 bool one_only = DECL_ONE_ONLY (decl);
4930 const char *prefix, *name;
4931 size_t nlen, plen;
4932 char *string;
4933
4934 switch (categorize_decl_for_section (decl, reloc, shlib))
4935 {
4936 case SECCAT_TEXT:
4937 prefix = one_only ? ".gnu.linkonce.t." : ".text.";
4938 break;
4939 case SECCAT_RODATA:
4940 case SECCAT_RODATA_MERGE_STR:
4941 case SECCAT_RODATA_MERGE_STR_INIT:
4942 case SECCAT_RODATA_MERGE_CONST:
4943 prefix = one_only ? ".gnu.linkonce.r." : ".rodata.";
4944 break;
4945 case SECCAT_SRODATA:
4946 prefix = one_only ? ".gnu.linkonce.s2." : ".sdata2.";
4947 break;
4948 case SECCAT_DATA:
4949 case SECCAT_DATA_REL:
4950 case SECCAT_DATA_REL_LOCAL:
4951 case SECCAT_DATA_REL_RO:
4952 case SECCAT_DATA_REL_RO_LOCAL:
4953 prefix = one_only ? ".gnu.linkonce.d." : ".data.";
4954 break;
4955 case SECCAT_SDATA:
4956 prefix = one_only ? ".gnu.linkonce.s." : ".sdata.";
4957 break;
4958 case SECCAT_BSS:
4959 prefix = one_only ? ".gnu.linkonce.b." : ".bss.";
4960 break;
4961 case SECCAT_SBSS:
4962 prefix = one_only ? ".gnu.linkonce.sb." : ".sbss.";
4963 break;
4964 case SECCAT_TDATA:
4965 prefix = one_only ? ".gnu.linkonce.td." : ".tdata.";
4966 break;
4967 case SECCAT_TBSS:
4968 prefix = one_only ? ".gnu.linkonce.tb." : ".tbss.";
4969 break;
4970 default:
4971 abort ();
4972 }
4973 plen = strlen (prefix);
4974
4975 name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
4976 name = (* targetm.strip_name_encoding) (name);
4977 nlen = strlen (name);
4978
4979 string = alloca (nlen + plen + 1);
4980 memcpy (string, prefix, plen);
4981 memcpy (string + plen, name, nlen + 1);
4982
4983 DECL_SECTION_NAME (decl) = build_string (nlen + plen, string);
4984 }
4985
4986 void
4987 default_select_rtx_section (enum machine_mode mode ATTRIBUTE_UNUSED,
4988 rtx x,
4989 unsigned HOST_WIDE_INT align ATTRIBUTE_UNUSED)
4990 {
4991 if (flag_pic)
4992 switch (GET_CODE (x))
4993 {
4994 case CONST:
4995 case SYMBOL_REF:
4996 case LABEL_REF:
4997 data_section ();
4998 return;
4999
5000 default:
5001 break;
5002 }
5003
5004 readonly_data_section ();
5005 }
5006
5007 void
5008 default_elf_select_rtx_section (enum machine_mode mode, rtx x,
5009 unsigned HOST_WIDE_INT align)
5010 {
5011 /* ??? Handle small data here somehow. */
5012
5013 if (flag_pic)
5014 switch (GET_CODE (x))
5015 {
5016 case CONST:
5017 case SYMBOL_REF:
5018 named_section (NULL_TREE, ".data.rel.ro", 3);
5019 return;
5020
5021 case LABEL_REF:
5022 named_section (NULL_TREE, ".data.rel.ro.local", 1);
5023 return;
5024
5025 default:
5026 break;
5027 }
5028
5029 mergeable_constant_section (mode, align, 0);
5030 }
5031
5032 /* Set the generally applicable flags on the SYMBOL_REF for EXP. */
5033
5034 void
5035 default_encode_section_info (tree decl, rtx rtl, int first ATTRIBUTE_UNUSED)
5036 {
5037 rtx symbol;
5038 int flags;
5039
5040 /* Careful not to prod global register variables. */
5041 if (GET_CODE (rtl) != MEM)
5042 return;
5043 symbol = XEXP (rtl, 0);
5044 if (GET_CODE (symbol) != SYMBOL_REF)
5045 return;
5046
5047 flags = 0;
5048 if (TREE_CODE (decl) == FUNCTION_DECL)
5049 flags |= SYMBOL_FLAG_FUNCTION;
5050 if ((*targetm.binds_local_p) (decl))
5051 flags |= SYMBOL_FLAG_LOCAL;
5052 if ((*targetm.in_small_data_p) (decl))
5053 flags |= SYMBOL_FLAG_SMALL;
5054 if (TREE_CODE (decl) == VAR_DECL && DECL_THREAD_LOCAL (decl))
5055 flags |= decl_tls_model (decl) << SYMBOL_FLAG_TLS_SHIFT;
5056 /* ??? Why is DECL_EXTERNAL ever set for non-PUBLIC names? Without
5057 being PUBLIC, the thing *must* be defined in this translation unit.
5058 Prevent this buglet from being propagated into rtl code as well. */
5059 if (DECL_P (decl) && DECL_EXTERNAL (decl) && TREE_PUBLIC (decl))
5060 flags |= SYMBOL_FLAG_EXTERNAL;
5061
5062 SYMBOL_REF_FLAGS (symbol) = flags;
5063 }
5064
5065 /* By default, we do nothing for encode_section_info, so we need not
5066 do anything but discard the '*' marker. */
5067
5068 const char *
5069 default_strip_name_encoding (const char *str)
5070 {
5071 return str + (*str == '*');
5072 }
5073
5074 /* Assume ELF-ish defaults, since that's pretty much the most liberal
5075 wrt cross-module name binding. */
5076
5077 bool
5078 default_binds_local_p (tree exp)
5079 {
5080 return default_binds_local_p_1 (exp, flag_shlib);
5081 }
5082
5083 bool
5084 default_binds_local_p_1 (tree exp, int shlib)
5085 {
5086 bool local_p;
5087
5088 /* A non-decl is an entry in the constant pool. */
5089 if (!DECL_P (exp))
5090 local_p = true;
5091 /* Static variables are always local. */
5092 else if (! TREE_PUBLIC (exp))
5093 local_p = true;
5094 /* A variable is local if the user tells us so. */
5095 else if (decl_visibility (exp) != VISIBILITY_DEFAULT)
5096 local_p = true;
5097 /* Otherwise, variables defined outside this object may not be local. */
5098 else if (DECL_EXTERNAL (exp))
5099 local_p = false;
5100 /* Linkonce and weak data are never local. */
5101 else if (DECL_ONE_ONLY (exp) || DECL_WEAK (exp))
5102 local_p = false;
5103 /* If PIC, then assume that any global name can be overridden by
5104 symbols resolved from other modules. */
5105 else if (shlib)
5106 local_p = false;
5107 /* Uninitialized COMMON variable may be unified with symbols
5108 resolved from other modules. */
5109 else if (DECL_COMMON (exp)
5110 && (DECL_INITIAL (exp) == NULL
5111 || DECL_INITIAL (exp) == error_mark_node))
5112 local_p = false;
5113 /* Otherwise we're left with initialized (or non-common) global data
5114 which is of necessity defined locally. */
5115 else
5116 local_p = true;
5117
5118 return local_p;
5119 }
5120
5121 /* Determine whether or not a pointer mode is valid. Assume defaults
5122 of ptr_mode or Pmode - can be overridden. */
5123 bool
5124 default_valid_pointer_mode (enum machine_mode mode)
5125 {
5126 return (mode == ptr_mode || mode == Pmode);
5127 }
5128
5129 /* Default function to output code that will globalize a label. A
5130 target must define GLOBAL_ASM_OP or provide it's own function to
5131 globalize a label. */
5132 #ifdef GLOBAL_ASM_OP
5133 void
5134 default_globalize_label (FILE * stream, const char *name)
5135 {
5136 fputs (GLOBAL_ASM_OP, stream);
5137 assemble_name (stream, name);
5138 putc ('\n', stream);
5139 }
5140 #endif /* GLOBAL_ASM_OP */
5141
5142 /* This is how to output an internal numbered label where PREFIX is
5143 the class of label and LABELNO is the number within the class. */
5144
5145 void
5146 default_internal_label (FILE *stream, const char *prefix,
5147 unsigned long labelno)
5148 {
5149 char *const buf = alloca (40 + strlen (prefix));
5150 ASM_GENERATE_INTERNAL_LABEL (buf, prefix, labelno);
5151 ASM_OUTPUT_LABEL (stream, buf);
5152 }
5153
5154 /* This is the default behavior at the beginning of a file. It's
5155 controlled by two other target-hook toggles. */
5156 void
5157 default_file_start (void)
5158 {
5159 if (targetm.file_start_app_off && !flag_verbose_asm)
5160 fputs (ASM_APP_OFF, asm_out_file);
5161
5162 if (targetm.file_start_file_directive)
5163 output_file_directive (asm_out_file, main_input_filename);
5164 }
5165
5166 /* This is a generic routine suitable for use as TARGET_ASM_FILE_END
5167 which emits a special section directive used to indicate whether or
5168 not this object file needs an executable stack. This is primarily
5169 a GNU extension to ELF but could be used on other targets. */
5170 void
5171 file_end_indicate_exec_stack (void)
5172 {
5173 unsigned int flags = SECTION_DEBUG;
5174 if (trampolines_created)
5175 flags |= SECTION_CODE;
5176
5177 named_section_flags (".note.GNU-stack", flags);
5178 }
5179
5180 #include "gt-varasm.h"