Warning fixes:
[gcc.git] / gcc / varasm.c
1 /* Output variables, constants and external declarations, for GNU compiler.
2 Copyright (C) 1987, 88, 89, 92-97, 1998 Free Software Foundation, Inc.
3
4 This file is part of GNU CC.
5
6 GNU CC is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 2, or (at your option)
9 any later version.
10
11 GNU CC is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
15
16 You should have received a copy of the GNU General Public License
17 along with GNU CC; see the file COPYING. If not, write to
18 the Free Software Foundation, 59 Temple Place - Suite 330,
19 Boston, MA 02111-1307, USA. */
20
21
22 /* This file handles generation of all the assembler code
23 *except* the instructions of a function.
24 This includes declarations of variables and their initial values.
25
26 We also output the assembler code for constants stored in memory
27 and are responsible for combining constants with the same value. */
28
29 #include "config.h"
30 #include "system.h"
31 #include <setjmp.h>
32 /* #include <stab.h> */
33 #include "rtl.h"
34 #include "tree.h"
35 #include "flags.h"
36 #include "except.h"
37 #include "function.h"
38 #include "expr.h"
39 #include "output.h"
40 #include "hard-reg-set.h"
41 #include "regs.h"
42 #include "defaults.h"
43 #include "real.h"
44 #include "toplev.h"
45 #include "dbxout.h"
46
47 #include "obstack.h"
48 #include "c-pragma.h"
49
50 #ifdef XCOFF_DEBUGGING_INFO
51 #include "xcoffout.h"
52 #endif
53
54 #ifndef TRAMPOLINE_ALIGNMENT
55 #define TRAMPOLINE_ALIGNMENT FUNCTION_BOUNDARY
56 #endif
57
58 #ifndef ASM_STABS_OP
59 #define ASM_STABS_OP ".stabs"
60 #endif
61
62 /* Define the prefix to use when check_memory_usage_flag is enable. */
63 #ifdef NO_DOLLAR_IN_LABEL
64 #ifdef NO_DOT_IN_LABEL
65 #define CHKR_PREFIX "chkr_prefix_"
66 #else /* !NO_DOT_IN_LABEL */
67 #define CHKR_PREFIX "chkr."
68 #endif
69 #else /* !NO_DOLLAR_IN_LABEL */
70 #define CHKR_PREFIX "chkr$"
71 #endif
72 #define CHKR_PREFIX_SIZE (sizeof (CHKR_PREFIX) - 1)
73
74 /* This macro gets just the user-specified name
75 out of the string in a SYMBOL_REF. On most machines,
76 we discard the * if any and that's all. */
77 #ifndef STRIP_NAME_ENCODING
78 #define STRIP_NAME_ENCODING(VAR,SYMBOL_NAME) \
79 (VAR) = ((SYMBOL_NAME) + ((SYMBOL_NAME)[0] == '*'))
80 #endif
81
82 /* File in which assembler code is being written. */
83
84 extern FILE *asm_out_file;
85
86 /* The (assembler) name of the first globally-visible object output. */
87 char *first_global_object_name;
88
89 extern struct obstack *current_obstack;
90 extern struct obstack *saveable_obstack;
91 extern struct obstack *rtl_obstack;
92 extern struct obstack permanent_obstack;
93 #define obstack_chunk_alloc xmalloc
94
95 /* Number for making the label on the next
96 constant that is stored in memory. */
97
98 int const_labelno;
99
100 /* Number for making the label on the next
101 static variable internal to a function. */
102
103 int var_labelno;
104
105 /* Carry information from ASM_DECLARE_OBJECT_NAME
106 to ASM_FINISH_DECLARE_OBJECT. */
107
108 int size_directive_output;
109
110 /* The last decl for which assemble_variable was called,
111 if it did ASM_DECLARE_OBJECT_NAME.
112 If the last call to assemble_variable didn't do that,
113 this holds 0. */
114
115 tree last_assemble_variable_decl;
116
117
118 #ifdef HANDLE_PRAGMA_WEAK
119 /* Any weak symbol declarations waiting to be emitted. */
120
121 struct weak_syms
122 {
123 struct weak_syms *next;
124 char *name;
125 char *value;
126 };
127
128 static struct weak_syms *weak_decls;
129 #endif
130
131 /* Nonzero if at least one function definition has been seen. */
132
133 static int function_defined;
134
135 struct addr_const;
136 struct constant_descriptor;
137 struct rtx_const;
138 struct pool_constant;
139
140 static char *strip_reg_name PROTO((char *));
141 static int contains_pointers_p PROTO((tree));
142 static void decode_addr_const PROTO((tree, struct addr_const *));
143 static int const_hash PROTO((tree));
144 static int compare_constant PROTO((tree,
145 struct constant_descriptor *));
146 static char *compare_constant_1 PROTO((tree, char *));
147 static struct constant_descriptor *record_constant PROTO((tree));
148 static void record_constant_1 PROTO((tree));
149 static tree copy_constant PROTO((tree));
150 static void output_constant_def_contents PROTO((tree, int, int));
151 static void decode_rtx_const PROTO((enum machine_mode, rtx,
152 struct rtx_const *));
153 static int const_hash_rtx PROTO((enum machine_mode, rtx));
154 static int compare_constant_rtx PROTO((enum machine_mode, rtx,
155 struct constant_descriptor *));
156 static struct constant_descriptor *record_constant_rtx PROTO((enum machine_mode,
157 rtx));
158 static struct pool_constant *find_pool_constant PROTO((rtx));
159 static void mark_constant_pool PROTO((void));
160 static void mark_constants PROTO((rtx));
161 static int output_addressed_constants PROTO((tree));
162 static void output_after_function_constants PROTO((void));
163 static void output_constructor PROTO((tree, int));
164 #ifdef ASM_OUTPUT_BSS
165 static void asm_output_bss PROTO((FILE *, tree, char *, int, int));
166 #endif
167 #ifdef BSS_SECTION_ASM_OP
168 #ifdef ASM_OUTPUT_ALIGNED_BSS
169 static void asm_output_aligned_bss PROTO((FILE *, tree, char *, int, int));
170 #endif
171 #endif /* BSS_SECTION_ASM_OP */
172 \f
173 static enum in_section { no_section, in_text, in_data, in_named
174 #ifdef BSS_SECTION_ASM_OP
175 , in_bss
176 #endif
177 #ifdef EH_FRAME_SECTION_ASM_OP
178 , in_eh_frame
179 #endif
180 #ifdef EXTRA_SECTIONS
181 , EXTRA_SECTIONS
182 #endif
183 } in_section = no_section;
184
185 /* Return a non-zero value if DECL has a section attribute. */
186 #define IN_NAMED_SECTION(DECL) \
187 ((TREE_CODE (DECL) == FUNCTION_DECL || TREE_CODE (DECL) == VAR_DECL) \
188 && DECL_SECTION_NAME (DECL) != NULL_TREE)
189
190 /* Text of section name when in_section == in_named. */
191 static char *in_named_name;
192
193 /* Define functions like text_section for any extra sections. */
194 #ifdef EXTRA_SECTION_FUNCTIONS
195 EXTRA_SECTION_FUNCTIONS
196 #endif
197
198 /* Tell assembler to switch to text section. */
199
200 void
201 text_section ()
202 {
203 if (in_section != in_text)
204 {
205 fprintf (asm_out_file, "%s\n", TEXT_SECTION_ASM_OP);
206 in_section = in_text;
207 }
208 }
209
210 /* Tell assembler to switch to data section. */
211
212 void
213 data_section ()
214 {
215 if (in_section != in_data)
216 {
217 if (flag_shared_data)
218 {
219 #ifdef SHARED_SECTION_ASM_OP
220 fprintf (asm_out_file, "%s\n", SHARED_SECTION_ASM_OP);
221 #else
222 fprintf (asm_out_file, "%s\n", DATA_SECTION_ASM_OP);
223 #endif
224 }
225 else
226 fprintf (asm_out_file, "%s\n", DATA_SECTION_ASM_OP);
227
228 in_section = in_data;
229 }
230 }
231
232 /* Tell assembler to switch to read-only data section. This is normally
233 the text section. */
234
235 void
236 readonly_data_section ()
237 {
238 #ifdef READONLY_DATA_SECTION
239 READONLY_DATA_SECTION (); /* Note this can call data_section. */
240 #else
241 text_section ();
242 #endif
243 }
244
245 /* Determine if we're in the text section. */
246
247 int
248 in_text_section ()
249 {
250 return in_section == in_text;
251 }
252
253 /* Determine if we're in the data section. */
254
255 int
256 in_data_section ()
257 {
258 return in_section == in_data;
259 }
260
261 /* Tell assembler to change to section NAME for DECL.
262 If DECL is NULL, just switch to section NAME.
263 If NAME is NULL, get the name from DECL.
264 If RELOC is 1, the initializer for DECL contains relocs. */
265
266 void
267 named_section (decl, name, reloc)
268 tree decl;
269 char *name;
270 int reloc;
271 {
272 if (decl != NULL_TREE
273 && TREE_CODE_CLASS (TREE_CODE (decl)) != 'd')
274 abort ();
275 if (name == NULL)
276 name = TREE_STRING_POINTER (DECL_SECTION_NAME (decl));
277
278 if (in_section != in_named || strcmp (name, in_named_name))
279 {
280 #ifdef ASM_OUTPUT_SECTION_NAME
281 ASM_OUTPUT_SECTION_NAME (asm_out_file, decl, name, reloc);
282 #else
283 /* Section attributes are not supported if this macro isn't provided -
284 some host formats don't support them at all. The front-end should
285 already have flagged this as an error. */
286 abort ();
287 #endif
288
289 in_named_name = obstack_alloc (&permanent_obstack, strlen (name) + 1);
290 strcpy (in_named_name, name);
291 in_section = in_named;
292 }
293 }
294
295 #ifdef ASM_OUTPUT_SECTION_NAME
296 #ifndef UNIQUE_SECTION
297 #define UNIQUE_SECTION(DECL,RELOC) \
298 do { \
299 int len; \
300 char *name, *string; \
301 \
302 name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (DECL)); \
303 /* Strip off any encoding in name. */ \
304 STRIP_NAME_ENCODING (name, name); \
305 \
306 len = strlen (name) + 1; \
307 string = alloca (len + 1); \
308 sprintf (string, ".%s", name); \
309 \
310 DECL_SECTION_NAME (DECL) = build_string (len, string); \
311 } while (0)
312 #endif
313 #ifndef UNIQUE_SECTION_P
314 #define UNIQUE_SECTION_P(DECL) 0
315 #endif
316 #endif
317
318 #ifdef BSS_SECTION_ASM_OP
319
320 /* Tell the assembler to switch to the bss section. */
321
322 void
323 bss_section ()
324 {
325 if (in_section != in_bss)
326 {
327 #ifdef SHARED_BSS_SECTION_ASM_OP
328 if (flag_shared_data)
329 fprintf (asm_out_file, "%s\n", SHARED_BSS_SECTION_ASM_OP);
330 else
331 #endif
332 fprintf (asm_out_file, "%s\n", BSS_SECTION_ASM_OP);
333
334 in_section = in_bss;
335 }
336 }
337
338 #ifdef ASM_OUTPUT_BSS
339
340 /* Utility function for ASM_OUTPUT_BSS for targets to use if
341 they don't support alignments in .bss.
342 ??? It is believed that this function will work in most cases so such
343 support is localized here. */
344
345 static void
346 asm_output_bss (file, decl, name, size, rounded)
347 FILE *file;
348 tree decl;
349 char *name;
350 int size, rounded;
351 {
352 ASM_GLOBALIZE_LABEL (file, name);
353 bss_section ();
354 #ifdef ASM_DECLARE_OBJECT_NAME
355 last_assemble_variable_decl = decl;
356 ASM_DECLARE_OBJECT_NAME (file, name, decl);
357 #else
358 /* Standard thing is just output label for the object. */
359 ASM_OUTPUT_LABEL (file, name);
360 #endif /* ASM_DECLARE_OBJECT_NAME */
361 ASM_OUTPUT_SKIP (file, rounded);
362 }
363
364 #endif
365
366 #ifdef ASM_OUTPUT_ALIGNED_BSS
367
368 /* Utility function for targets to use in implementing
369 ASM_OUTPUT_ALIGNED_BSS.
370 ??? It is believed that this function will work in most cases so such
371 support is localized here. */
372
373 static void
374 asm_output_aligned_bss (file, decl, name, size, align)
375 FILE *file;
376 tree decl;
377 char *name;
378 int size, align;
379 {
380 ASM_GLOBALIZE_LABEL (file, name);
381 bss_section ();
382 ASM_OUTPUT_ALIGN (file, floor_log2 (align / BITS_PER_UNIT));
383 #ifdef ASM_DECLARE_OBJECT_NAME
384 last_assemble_variable_decl = decl;
385 ASM_DECLARE_OBJECT_NAME (file, name, decl);
386 #else
387 /* Standard thing is just output label for the object. */
388 ASM_OUTPUT_LABEL (file, name);
389 #endif /* ASM_DECLARE_OBJECT_NAME */
390 ASM_OUTPUT_SKIP (file, size ? size : 1);
391 }
392
393 #endif
394
395 #endif /* BSS_SECTION_ASM_OP */
396
397 #ifdef EH_FRAME_SECTION_ASM_OP
398 void
399 eh_frame_section ()
400 {
401 if (in_section != in_eh_frame)
402 {
403 fprintf (asm_out_file, "%s\n", EH_FRAME_SECTION_ASM_OP);
404 in_section = in_eh_frame;
405 }
406 }
407 #endif
408
409 /* Switch to the section for function DECL.
410
411 If DECL is NULL_TREE, switch to the text section.
412 ??? It's not clear that we will ever be passed NULL_TREE, but it's
413 safer to handle it. */
414
415 void
416 function_section (decl)
417 tree decl;
418 {
419 if (decl != NULL_TREE
420 && DECL_SECTION_NAME (decl) != NULL_TREE)
421 named_section (decl, (char *) 0, 0);
422 else
423 text_section ();
424 }
425
426 /* Switch to section for variable DECL.
427
428 RELOC is the `reloc' argument to SELECT_SECTION. */
429
430 void
431 variable_section (decl, reloc)
432 tree decl;
433 int reloc;
434 {
435 if (IN_NAMED_SECTION (decl))
436 named_section (decl, NULL, reloc);
437 else
438 {
439 /* C++ can have const variables that get initialized from constructors,
440 and thus can not be in a readonly section. We prevent this by
441 verifying that the initial value is constant for objects put in a
442 readonly section.
443
444 error_mark_node is used by the C front end to indicate that the
445 initializer has not been seen yet. In this case, we assume that
446 the initializer must be constant.
447
448 C++ uses error_mark_node for variables that have complicated
449 initializers, but these variables go in BSS so we won't be called
450 for them. */
451
452 #ifdef SELECT_SECTION
453 SELECT_SECTION (decl, reloc);
454 #else
455 if (DECL_READONLY_SECTION (decl, reloc))
456 readonly_data_section ();
457 else
458 data_section ();
459 #endif
460 }
461 }
462
463 /* Tell assembler to switch to the section for the exception handling
464 table. */
465
466 void
467 exception_section ()
468 {
469 #if defined (EXCEPTION_SECTION)
470 EXCEPTION_SECTION ();
471 #else
472 #ifdef ASM_OUTPUT_SECTION_NAME
473 named_section (NULL_TREE, ".gcc_except_table", 0);
474 #else
475 if (flag_pic)
476 data_section ();
477 else
478 readonly_data_section ();
479 #endif
480 #endif
481 }
482 \f
483 /* Create the rtl to represent a function, for a function definition.
484 DECL is a FUNCTION_DECL node which describes which function.
485 The rtl is stored into DECL. */
486
487 void
488 make_function_rtl (decl)
489 tree decl;
490 {
491 char *name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
492 char *new_name = name;
493
494 /* Rename a nested function to avoid conflicts. */
495 if (decl_function_context (decl) != 0
496 && DECL_INITIAL (decl) != 0
497 && DECL_RTL (decl) == 0)
498 {
499 char *label;
500
501 name = IDENTIFIER_POINTER (DECL_NAME (decl));
502 ASM_FORMAT_PRIVATE_NAME (label, name, var_labelno);
503 name = obstack_copy0 (saveable_obstack, label, strlen (label));
504 var_labelno++;
505 }
506 else
507 {
508 /* When -fprefix-function-name is used, every function name is
509 prefixed. Even static functions are prefixed because they
510 could be declared latter. Note that a nested function name
511 is not prefixed. */
512 if (flag_prefix_function_name)
513 {
514 new_name = (char *) alloca (strlen (name) + CHKR_PREFIX_SIZE + 1);
515 strcpy (new_name, CHKR_PREFIX);
516 strcpy (new_name + CHKR_PREFIX_SIZE, name);
517 name = obstack_copy0 (saveable_obstack, new_name, strlen (new_name));
518 }
519 }
520
521 if (DECL_RTL (decl) == 0)
522 {
523 DECL_RTL (decl)
524 = gen_rtx_MEM (DECL_MODE (decl),
525 gen_rtx_SYMBOL_REF (Pmode, name));
526
527 /* Optionally set flags or add text to the name to record information
528 such as that it is a function name. If the name is changed, the macro
529 ASM_OUTPUT_LABELREF will have to know how to strip this information. */
530 #ifdef ENCODE_SECTION_INFO
531 ENCODE_SECTION_INFO (decl);
532 #endif
533 }
534 else
535 {
536 /* ??? Another way to do this would be to do what halfpic.c does
537 and maintain a hashed table of such critters. */
538 /* ??? Another way to do this would be to pass a flag bit to
539 ENCODE_SECTION_INFO saying whether this is a new decl or not. */
540 /* Let the target reassign the RTL if it wants.
541 This is necessary, for example, when one machine specific
542 decl attribute overrides another. */
543 #ifdef REDO_SECTION_INFO_P
544 if (REDO_SECTION_INFO_P (decl))
545 ENCODE_SECTION_INFO (decl);
546 #endif
547 }
548
549 /* Record at least one function has been defined. */
550 function_defined = 1;
551 }
552
553 /* Given NAME, a putative register name, discard any customary prefixes. */
554
555 static char *
556 strip_reg_name (name)
557 char *name;
558 {
559 #ifdef REGISTER_PREFIX
560 if (!strncmp (name, REGISTER_PREFIX, strlen (REGISTER_PREFIX)))
561 name += strlen (REGISTER_PREFIX);
562 #endif
563 if (name[0] == '%' || name[0] == '#')
564 name++;
565 return name;
566 }
567 \f
568 /* Decode an `asm' spec for a declaration as a register name.
569 Return the register number, or -1 if nothing specified,
570 or -2 if the ASMSPEC is not `cc' or `memory' and is not recognized,
571 or -3 if ASMSPEC is `cc' and is not recognized,
572 or -4 if ASMSPEC is `memory' and is not recognized.
573 Accept an exact spelling or a decimal number.
574 Prefixes such as % are optional. */
575
576 int
577 decode_reg_name (asmspec)
578 char *asmspec;
579 {
580 if (asmspec != 0)
581 {
582 int i;
583
584 /* Get rid of confusing prefixes. */
585 asmspec = strip_reg_name (asmspec);
586
587 /* Allow a decimal number as a "register name". */
588 for (i = strlen (asmspec) - 1; i >= 0; i--)
589 if (! (asmspec[i] >= '0' && asmspec[i] <= '9'))
590 break;
591 if (asmspec[0] != 0 && i < 0)
592 {
593 i = atoi (asmspec);
594 if (i < FIRST_PSEUDO_REGISTER && i >= 0)
595 return i;
596 else
597 return -2;
598 }
599
600 for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
601 if (reg_names[i][0]
602 && ! strcmp (asmspec, strip_reg_name (reg_names[i])))
603 return i;
604
605 #ifdef ADDITIONAL_REGISTER_NAMES
606 {
607 static struct { char *name; int number; } table[]
608 = ADDITIONAL_REGISTER_NAMES;
609
610 for (i = 0; i < sizeof (table) / sizeof (table[0]); i++)
611 if (! strcmp (asmspec, table[i].name))
612 return table[i].number;
613 }
614 #endif /* ADDITIONAL_REGISTER_NAMES */
615
616 if (!strcmp (asmspec, "memory"))
617 return -4;
618
619 if (!strcmp (asmspec, "cc"))
620 return -3;
621
622 return -2;
623 }
624
625 return -1;
626 }
627 \f
628 /* Create the DECL_RTL for a declaration for a static or external variable
629 or static or external function.
630 ASMSPEC, if not 0, is the string which the user specified
631 as the assembler symbol name.
632 TOP_LEVEL is nonzero if this is a file-scope variable.
633
634 This is never called for PARM_DECL nodes. */
635
636 void
637 make_decl_rtl (decl, asmspec, top_level)
638 tree decl;
639 char *asmspec;
640 int top_level;
641 {
642 register char *name = 0;
643 int reg_number;
644
645 reg_number = decode_reg_name (asmspec);
646
647 if (DECL_ASSEMBLER_NAME (decl) != NULL_TREE)
648 name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
649
650 if (reg_number == -2)
651 {
652 /* ASMSPEC is given, and not the name of a register. */
653 name = (char *) obstack_alloc (saveable_obstack,
654 strlen (asmspec) + 2);
655 name[0] = '*';
656 strcpy (&name[1], asmspec);
657 }
658
659 /* For a duplicate declaration, we can be called twice on the
660 same DECL node. Don't discard the RTL already made. */
661 if (DECL_RTL (decl) == 0)
662 {
663 DECL_RTL (decl) = 0;
664
665 /* First detect errors in declaring global registers. */
666 if (TREE_CODE (decl) != FUNCTION_DECL
667 && DECL_REGISTER (decl) && reg_number == -1)
668 error_with_decl (decl,
669 "register name not specified for `%s'");
670 else if (TREE_CODE (decl) != FUNCTION_DECL
671 && DECL_REGISTER (decl) && reg_number < 0)
672 error_with_decl (decl,
673 "invalid register name for `%s'");
674 else if ((reg_number >= 0 || reg_number == -3)
675 && (TREE_CODE (decl) == FUNCTION_DECL
676 && ! DECL_REGISTER (decl)))
677 error_with_decl (decl,
678 "register name given for non-register variable `%s'");
679 else if (TREE_CODE (decl) != FUNCTION_DECL
680 && DECL_REGISTER (decl)
681 && TYPE_MODE (TREE_TYPE (decl)) == BLKmode)
682 error_with_decl (decl,
683 "data type of `%s' isn't suitable for a register");
684 else if (TREE_CODE (decl) != FUNCTION_DECL && DECL_REGISTER (decl)
685 && ! HARD_REGNO_MODE_OK (reg_number,
686 TYPE_MODE (TREE_TYPE (decl))))
687 error_with_decl (decl,
688 "register number for `%s' isn't suitable for data type");
689 /* Now handle properly declared static register variables. */
690 else if (TREE_CODE (decl) != FUNCTION_DECL && DECL_REGISTER (decl))
691 {
692 int nregs;
693
694 if (DECL_INITIAL (decl) != 0 && top_level)
695 {
696 DECL_INITIAL (decl) = 0;
697 error ("global register variable has initial value");
698 }
699 if (fixed_regs[reg_number] == 0
700 && function_defined && top_level)
701 error ("global register variable follows a function definition");
702 if (TREE_THIS_VOLATILE (decl))
703 warning ("volatile register variables don't work as you might wish");
704
705 /* If the user specified one of the eliminables registers here,
706 e.g., FRAME_POINTER_REGNUM, we don't want to get this variable
707 confused with that register and be eliminated. Although this
708 usage is somewhat suspect, we nevertheless use the following
709 kludge to avoid setting DECL_RTL to frame_pointer_rtx. */
710
711 DECL_RTL (decl)
712 = gen_rtx_REG (DECL_MODE (decl), FIRST_PSEUDO_REGISTER);
713 REGNO (DECL_RTL (decl)) = reg_number;
714 REG_USERVAR_P (DECL_RTL (decl)) = 1;
715
716 if (top_level)
717 {
718 /* Make this register global, so not usable for anything
719 else. */
720 nregs = HARD_REGNO_NREGS (reg_number, DECL_MODE (decl));
721 while (nregs > 0)
722 globalize_reg (reg_number + --nregs);
723 }
724 }
725 /* Specifying a section attribute on a variable forces it into a
726 non-.bss section, and thus it cannot be common. */
727 else if (TREE_CODE (decl) == VAR_DECL
728 && DECL_SECTION_NAME (decl) != NULL_TREE
729 && DECL_INITIAL (decl) == NULL_TREE
730 && DECL_COMMON (decl))
731 DECL_COMMON (decl) = 0;
732
733 /* Now handle ordinary static variables and functions (in memory).
734 Also handle vars declared register invalidly. */
735 if (DECL_RTL (decl) == 0)
736 {
737 /* Can't use just the variable's own name for a variable
738 whose scope is less than the whole file.
739 Concatenate a distinguishing number. */
740 if (!top_level && !TREE_PUBLIC (decl) && asmspec == 0)
741 {
742 char *label;
743
744 ASM_FORMAT_PRIVATE_NAME (label, name, var_labelno);
745 name = obstack_copy0 (saveable_obstack, label, strlen (label));
746 var_labelno++;
747 }
748
749 if (name == 0)
750 abort ();
751
752 /* When -fprefix-function-name is used, the functions
753 names are prefixed. Only nested function names are not
754 prefixed. */
755 if (flag_prefix_function_name && TREE_CODE (decl) == FUNCTION_DECL)
756 {
757 char *new_name;
758 new_name = (char *) alloca (strlen (name) + CHKR_PREFIX_SIZE
759 + 1);
760 strcpy (new_name, CHKR_PREFIX);
761 strcpy (new_name + CHKR_PREFIX_SIZE, name);
762 name = obstack_copy0 (saveable_obstack,
763 new_name, strlen (new_name));
764 }
765
766 DECL_RTL (decl) = gen_rtx_MEM (DECL_MODE (decl),
767 gen_rtx_SYMBOL_REF (Pmode, name));
768
769 /* If this variable is to be treated as volatile, show its
770 tree node has side effects. If it has side effects, either
771 because of this test or from TREE_THIS_VOLATILE also
772 being set, show the MEM is volatile. */
773 if (flag_volatile_global && TREE_CODE (decl) == VAR_DECL
774 && TREE_PUBLIC (decl))
775 TREE_SIDE_EFFECTS (decl) = 1;
776 if (TREE_SIDE_EFFECTS (decl))
777 MEM_VOLATILE_P (DECL_RTL (decl)) = 1;
778
779 if (TREE_READONLY (decl))
780 RTX_UNCHANGING_P (DECL_RTL (decl)) = 1;
781 MEM_IN_STRUCT_P (DECL_RTL (decl))
782 = AGGREGATE_TYPE_P (TREE_TYPE (decl));
783
784 /* Optionally set flags or add text to the name to record information
785 such as that it is a function name.
786 If the name is changed, the macro ASM_OUTPUT_LABELREF
787 will have to know how to strip this information. */
788 #ifdef ENCODE_SECTION_INFO
789 ENCODE_SECTION_INFO (decl);
790 #endif
791 }
792 }
793 else
794 {
795 /* If the old RTL had the wrong mode, fix the mode. */
796 if (GET_MODE (DECL_RTL (decl)) != DECL_MODE (decl))
797 {
798 rtx rtl = DECL_RTL (decl);
799 PUT_MODE (rtl, DECL_MODE (decl));
800 }
801
802 /* ??? Another way to do this would be to do what halfpic.c does
803 and maintain a hashed table of such critters. */
804 /* ??? Another way to do this would be to pass a flag bit to
805 ENCODE_SECTION_INFO saying whether this is a new decl or not. */
806 /* Let the target reassign the RTL if it wants.
807 This is necessary, for example, when one machine specific
808 decl attribute overrides another. */
809 #ifdef REDO_SECTION_INFO_P
810 if (REDO_SECTION_INFO_P (decl))
811 ENCODE_SECTION_INFO (decl);
812 #endif
813 }
814 }
815
816 /* Make the rtl for variable VAR be volatile.
817 Use this only for static variables. */
818
819 void
820 make_var_volatile (var)
821 tree var;
822 {
823 if (GET_CODE (DECL_RTL (var)) != MEM)
824 abort ();
825
826 MEM_VOLATILE_P (DECL_RTL (var)) = 1;
827 }
828 \f
829 /* Output alignment directive to align for constant expression EXP. */
830
831 void
832 assemble_constant_align (exp)
833 tree exp;
834 {
835 int align;
836
837 /* Align the location counter as required by EXP's data type. */
838 align = TYPE_ALIGN (TREE_TYPE (exp));
839 #ifdef CONSTANT_ALIGNMENT
840 align = CONSTANT_ALIGNMENT (exp, align);
841 #endif
842
843 if (align > BITS_PER_UNIT)
844 ASM_OUTPUT_ALIGN (asm_out_file, floor_log2 (align / BITS_PER_UNIT));
845 }
846
847 /* Output a string of literal assembler code
848 for an `asm' keyword used between functions. */
849
850 void
851 assemble_asm (string)
852 tree string;
853 {
854 app_enable ();
855
856 if (TREE_CODE (string) == ADDR_EXPR)
857 string = TREE_OPERAND (string, 0);
858
859 fprintf (asm_out_file, "\t%s\n", TREE_STRING_POINTER (string));
860 }
861
862 #if 0 /* This should no longer be needed, because
863 flag_gnu_linker should be 0 on these systems,
864 which should prevent any output
865 if ASM_OUTPUT_CONSTRUCTOR and ASM_OUTPUT_DESTRUCTOR are absent. */
866 #if !(defined(DBX_DEBUGGING_INFO) && !defined(FASCIST_ASSEMBLER))
867 #ifndef ASM_OUTPUT_CONSTRUCTOR
868 #define ASM_OUTPUT_CONSTRUCTOR(file, name)
869 #endif
870 #ifndef ASM_OUTPUT_DESTRUCTOR
871 #define ASM_OUTPUT_DESTRUCTOR(file, name)
872 #endif
873 #endif
874 #endif /* 0 */
875
876 /* Record an element in the table of global destructors.
877 How this is done depends on what sort of assembler and linker
878 are in use.
879
880 NAME should be the name of a global function to be called
881 at exit time. This name is output using assemble_name. */
882
883 void
884 assemble_destructor (name)
885 char *name;
886 {
887 #ifdef ASM_OUTPUT_DESTRUCTOR
888 ASM_OUTPUT_DESTRUCTOR (asm_out_file, name);
889 #else
890 if (flag_gnu_linker)
891 {
892 /* Now tell GNU LD that this is part of the static destructor set. */
893 /* This code works for any machine provided you use GNU as/ld. */
894 fprintf (asm_out_file, "%s \"___DTOR_LIST__\",22,0,0,", ASM_STABS_OP);
895 assemble_name (asm_out_file, name);
896 fputc ('\n', asm_out_file);
897 }
898 #endif
899 }
900
901 /* Likewise for global constructors. */
902
903 void
904 assemble_constructor (name)
905 char *name;
906 {
907 #ifdef ASM_OUTPUT_CONSTRUCTOR
908 ASM_OUTPUT_CONSTRUCTOR (asm_out_file, name);
909 #else
910 if (flag_gnu_linker)
911 {
912 /* Now tell GNU LD that this is part of the static constructor set. */
913 /* This code works for any machine provided you use GNU as/ld. */
914 fprintf (asm_out_file, "%s \"___CTOR_LIST__\",22,0,0,", ASM_STABS_OP);
915 assemble_name (asm_out_file, name);
916 fputc ('\n', asm_out_file);
917 }
918 #endif
919 }
920
921 /* Likewise for entries we want to record for garbage collection.
922 Garbage collection is still under development. */
923
924 void
925 assemble_gc_entry (name)
926 char *name;
927 {
928 #ifdef ASM_OUTPUT_GC_ENTRY
929 ASM_OUTPUT_GC_ENTRY (asm_out_file, name);
930 #else
931 if (flag_gnu_linker)
932 {
933 /* Now tell GNU LD that this is part of the static constructor set. */
934 fprintf (asm_out_file, "%s \"___PTR_LIST__\",22,0,0,", ASM_STABS_OP);
935 assemble_name (asm_out_file, name);
936 fputc ('\n', asm_out_file);
937 }
938 #endif
939 }
940 \f
941 /* CONSTANT_POOL_BEFORE_FUNCTION may be defined as an expression with
942 a non-zero value if the constant pool should be output before the
943 start of the function, or a zero value if the pool should output
944 after the end of the function. The default is to put it before the
945 start. */
946
947 #ifndef CONSTANT_POOL_BEFORE_FUNCTION
948 #define CONSTANT_POOL_BEFORE_FUNCTION 1
949 #endif
950
951 /* Output assembler code for the constant pool of a function and associated
952 with defining the name of the function. DECL describes the function.
953 NAME is the function's name. For the constant pool, we use the current
954 constant pool data. */
955
956 void
957 assemble_start_function (decl, fnname)
958 tree decl;
959 char *fnname;
960 {
961 int align;
962
963 /* The following code does not need preprocessing in the assembler. */
964
965 app_disable ();
966
967 if (CONSTANT_POOL_BEFORE_FUNCTION)
968 output_constant_pool (fnname, decl);
969
970 #ifdef ASM_OUTPUT_SECTION_NAME
971 /* If the function is to be put in its own section and it's not in a section
972 already, indicate so. */
973 if ((flag_function_sections
974 && DECL_SECTION_NAME (decl) == NULL_TREE)
975 || UNIQUE_SECTION_P (decl))
976 UNIQUE_SECTION (decl, 0);
977 #endif
978
979 function_section (decl);
980
981 /* Tell assembler to move to target machine's alignment for functions. */
982 align = floor_log2 (FUNCTION_BOUNDARY / BITS_PER_UNIT);
983 if (align > 0)
984 ASM_OUTPUT_ALIGN (asm_out_file, align);
985
986 #ifdef ASM_OUTPUT_FUNCTION_PREFIX
987 ASM_OUTPUT_FUNCTION_PREFIX (asm_out_file, fnname);
988 #endif
989
990 #ifdef SDB_DEBUGGING_INFO
991 /* Output SDB definition of the function. */
992 if (write_symbols == SDB_DEBUG)
993 sdbout_mark_begin_function ();
994 #endif
995
996 #ifdef DBX_DEBUGGING_INFO
997 /* Output DBX definition of the function. */
998 if (write_symbols == DBX_DEBUG)
999 dbxout_begin_function (decl);
1000 #endif
1001
1002 /* Make function name accessible from other files, if appropriate. */
1003
1004 if (TREE_PUBLIC (decl))
1005 {
1006 if (!first_global_object_name && ! DECL_WEAK (decl)
1007 && ! DECL_ONE_ONLY (decl))
1008 {
1009 char *p;
1010
1011 STRIP_NAME_ENCODING (p, fnname);
1012 first_global_object_name = permalloc (strlen (p) + 1);
1013 strcpy (first_global_object_name, p);
1014 }
1015
1016 #ifdef ASM_WEAKEN_LABEL
1017 if (DECL_WEAK (decl))
1018 ASM_WEAKEN_LABEL (asm_out_file, fnname);
1019 else
1020 #endif
1021 ASM_GLOBALIZE_LABEL (asm_out_file, fnname);
1022 }
1023
1024 /* Do any machine/system dependent processing of the function name */
1025 #ifdef ASM_DECLARE_FUNCTION_NAME
1026 ASM_DECLARE_FUNCTION_NAME (asm_out_file, fnname, current_function_decl);
1027 #else
1028 /* Standard thing is just output label for the function. */
1029 ASM_OUTPUT_LABEL (asm_out_file, fnname);
1030 #endif /* ASM_DECLARE_FUNCTION_NAME */
1031 }
1032
1033 /* Output assembler code associated with defining the size of the
1034 function. DECL describes the function. NAME is the function's name. */
1035
1036 void
1037 assemble_end_function (decl, fnname)
1038 tree decl;
1039 char *fnname;
1040 {
1041 #ifdef ASM_DECLARE_FUNCTION_SIZE
1042 ASM_DECLARE_FUNCTION_SIZE (asm_out_file, fnname, decl);
1043 #endif
1044 if (! CONSTANT_POOL_BEFORE_FUNCTION)
1045 {
1046 output_constant_pool (fnname, decl);
1047 function_section (decl); /* need to switch back */
1048 }
1049
1050 /* Output any constants which should appear after the function. */
1051 output_after_function_constants ();
1052 }
1053 \f
1054 /* Assemble code to leave SIZE bytes of zeros. */
1055
1056 void
1057 assemble_zeros (size)
1058 int size;
1059 {
1060 #ifdef ASM_NO_SKIP_IN_TEXT
1061 /* The `space' pseudo in the text section outputs nop insns rather than 0s,
1062 so we must output 0s explicitly in the text section. */
1063 if (ASM_NO_SKIP_IN_TEXT && in_text_section ())
1064 {
1065 int i;
1066
1067 for (i = 0; i < size - 20; i += 20)
1068 {
1069 #ifdef ASM_BYTE_OP
1070 fprintf (asm_out_file,
1071 "%s 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0\n", ASM_BYTE_OP);
1072 #else
1073 fprintf (asm_out_file,
1074 "\tbyte 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0\n");
1075 #endif
1076 }
1077 if (i < size)
1078 {
1079 #ifdef ASM_BYTE_OP
1080 fprintf (asm_out_file, "%s 0", ASM_BYTE_OP);
1081 #else
1082 fprintf (asm_out_file, "\tbyte 0");
1083 #endif
1084 i++;
1085 for (; i < size; i++)
1086 fprintf (asm_out_file, ",0");
1087 fprintf (asm_out_file, "\n");
1088 }
1089 }
1090 else
1091 #endif
1092 if (size > 0)
1093 ASM_OUTPUT_SKIP (asm_out_file, size);
1094 }
1095
1096 /* Assemble an alignment pseudo op for an ALIGN-bit boundary. */
1097
1098 void
1099 assemble_align (align)
1100 int align;
1101 {
1102 if (align > BITS_PER_UNIT)
1103 ASM_OUTPUT_ALIGN (asm_out_file, floor_log2 (align / BITS_PER_UNIT));
1104 }
1105
1106 /* Assemble a string constant with the specified C string as contents. */
1107
1108 void
1109 assemble_string (p, size)
1110 char *p;
1111 int size;
1112 {
1113 int pos = 0;
1114 int maximum = 2000;
1115
1116 /* If the string is very long, split it up. */
1117
1118 while (pos < size)
1119 {
1120 int thissize = size - pos;
1121 if (thissize > maximum)
1122 thissize = maximum;
1123
1124 ASM_OUTPUT_ASCII (asm_out_file, p, thissize);
1125
1126 pos += thissize;
1127 p += thissize;
1128 }
1129 }
1130
1131 \f
1132 /* Assemble everything that is needed for a variable or function declaration.
1133 Not used for automatic variables, and not used for function definitions.
1134 Should not be called for variables of incomplete structure type.
1135
1136 TOP_LEVEL is nonzero if this variable has file scope.
1137 AT_END is nonzero if this is the special handling, at end of compilation,
1138 to define things that have had only tentative definitions.
1139 DONT_OUTPUT_DATA if nonzero means don't actually output the
1140 initial value (that will be done by the caller). */
1141
1142 void
1143 assemble_variable (decl, top_level, at_end, dont_output_data)
1144 tree decl;
1145 int top_level;
1146 int at_end;
1147 int dont_output_data;
1148 {
1149 register char *name;
1150 unsigned int align;
1151 tree size_tree;
1152 int reloc = 0;
1153 enum in_section saved_in_section;
1154
1155 last_assemble_variable_decl = 0;
1156
1157 if (GET_CODE (DECL_RTL (decl)) == REG)
1158 {
1159 /* Do output symbol info for global register variables, but do nothing
1160 else for them. */
1161
1162 if (TREE_ASM_WRITTEN (decl))
1163 return;
1164 TREE_ASM_WRITTEN (decl) = 1;
1165
1166 #if defined (DBX_DEBUGGING_INFO) || defined (XCOFF_DEBUGGING_INFO)
1167 /* File-scope global variables are output here. */
1168 if ((write_symbols == DBX_DEBUG || write_symbols == XCOFF_DEBUG)
1169 && top_level)
1170 dbxout_symbol (decl, 0);
1171 #endif
1172 #ifdef SDB_DEBUGGING_INFO
1173 if (write_symbols == SDB_DEBUG && top_level
1174 /* Leave initialized global vars for end of compilation;
1175 see comment in compile_file. */
1176 && (TREE_PUBLIC (decl) == 0 || DECL_INITIAL (decl) == 0))
1177 sdbout_symbol (decl, 0);
1178 #endif
1179
1180 /* Don't output any DWARF debugging information for variables here.
1181 In the case of local variables, the information for them is output
1182 when we do our recursive traversal of the tree representation for
1183 the entire containing function. In the case of file-scope variables,
1184 we output information for all of them at the very end of compilation
1185 while we are doing our final traversal of the chain of file-scope
1186 declarations. */
1187
1188 return;
1189 }
1190
1191 /* Normally no need to say anything here for external references,
1192 since assemble_external is called by the language-specific code
1193 when a declaration is first seen. */
1194
1195 if (DECL_EXTERNAL (decl))
1196 return;
1197
1198 /* Output no assembler code for a function declaration.
1199 Only definitions of functions output anything. */
1200
1201 if (TREE_CODE (decl) == FUNCTION_DECL)
1202 return;
1203
1204 /* If type was incomplete when the variable was declared,
1205 see if it is complete now. */
1206
1207 if (DECL_SIZE (decl) == 0)
1208 layout_decl (decl, 0);
1209
1210 /* Still incomplete => don't allocate it; treat the tentative defn
1211 (which is what it must have been) as an `extern' reference. */
1212
1213 if (!dont_output_data && DECL_SIZE (decl) == 0)
1214 {
1215 error_with_file_and_line (DECL_SOURCE_FILE (decl),
1216 DECL_SOURCE_LINE (decl),
1217 "storage size of `%s' isn't known",
1218 IDENTIFIER_POINTER (DECL_NAME (decl)));
1219 TREE_ASM_WRITTEN (decl) = 1;
1220 return;
1221 }
1222
1223 /* The first declaration of a variable that comes through this function
1224 decides whether it is global (in C, has external linkage)
1225 or local (in C, has internal linkage). So do nothing more
1226 if this function has already run. */
1227
1228 if (TREE_ASM_WRITTEN (decl))
1229 return;
1230
1231 TREE_ASM_WRITTEN (decl) = 1;
1232
1233 app_disable ();
1234
1235 if (! dont_output_data)
1236 {
1237 int size;
1238
1239 if (TREE_CODE (DECL_SIZE (decl)) != INTEGER_CST)
1240 goto finish;
1241
1242 /* This is better than explicit arithmetic, since it avoids overflow. */
1243 size_tree = size_binop (CEIL_DIV_EXPR,
1244 DECL_SIZE (decl), size_int (BITS_PER_UNIT));
1245
1246 size = TREE_INT_CST_LOW (size_tree);
1247 if (TREE_INT_CST_HIGH (size_tree) != 0
1248 || size != TREE_INT_CST_LOW (size_tree))
1249 {
1250 error_with_decl (decl, "size of variable `%s' is too large");
1251 goto finish;
1252 }
1253 }
1254
1255 name = XSTR (XEXP (DECL_RTL (decl), 0), 0);
1256
1257 if (TREE_PUBLIC (decl) && DECL_NAME (decl)
1258 && ! first_global_object_name
1259 && ! (DECL_COMMON (decl) && (DECL_INITIAL (decl) == 0
1260 || DECL_INITIAL (decl) == error_mark_node))
1261 && ! DECL_WEAK (decl)
1262 && ! DECL_ONE_ONLY (decl))
1263 {
1264 char *p;
1265
1266 STRIP_NAME_ENCODING (p, name);
1267 first_global_object_name = permalloc (strlen (p) + 1);
1268 strcpy (first_global_object_name, p);
1269 }
1270
1271 /* Compute the alignment of this data. */
1272
1273 align = DECL_ALIGN (decl);
1274
1275 /* In the case for initialing an array whose length isn't specified,
1276 where we have not yet been able to do the layout,
1277 figure out the proper alignment now. */
1278 if (dont_output_data && DECL_SIZE (decl) == 0
1279 && TREE_CODE (TREE_TYPE (decl)) == ARRAY_TYPE)
1280 align = MAX (align, TYPE_ALIGN (TREE_TYPE (TREE_TYPE (decl))));
1281
1282 /* Some object file formats have a maximum alignment which they support.
1283 In particular, a.out format supports a maximum alignment of 4. */
1284 #ifndef MAX_OFILE_ALIGNMENT
1285 #define MAX_OFILE_ALIGNMENT BIGGEST_ALIGNMENT
1286 #endif
1287 if (align > MAX_OFILE_ALIGNMENT)
1288 {
1289 warning_with_decl (decl,
1290 "alignment of `%s' is greater than maximum object file alignment. Using %d.",
1291 MAX_OFILE_ALIGNMENT/BITS_PER_UNIT);
1292 align = MAX_OFILE_ALIGNMENT;
1293 }
1294
1295 /* On some machines, it is good to increase alignment sometimes. */
1296 #ifdef DATA_ALIGNMENT
1297 align = DATA_ALIGNMENT (TREE_TYPE (decl), align);
1298 #endif
1299 #ifdef CONSTANT_ALIGNMENT
1300 if (DECL_INITIAL (decl) != 0 && DECL_INITIAL (decl) != error_mark_node)
1301 align = CONSTANT_ALIGNMENT (DECL_INITIAL (decl), align);
1302 #endif
1303
1304 /* Reset the alignment in case we have made it tighter, so we can benefit
1305 from it in get_pointer_alignment. */
1306 DECL_ALIGN (decl) = align;
1307
1308 /* Handle uninitialized definitions. */
1309
1310 if ((DECL_INITIAL (decl) == 0 || DECL_INITIAL (decl) == error_mark_node)
1311 /* If the target can't output uninitialized but not common global data
1312 in .bss, then we have to use .data. */
1313 #if ! defined (ASM_OUTPUT_BSS) && ! defined (ASM_OUTPUT_ALIGNED_BSS)
1314 && DECL_COMMON (decl)
1315 #endif
1316 && ! dont_output_data)
1317 {
1318 int size = TREE_INT_CST_LOW (size_tree);
1319 int rounded = size;
1320
1321 /* Don't allocate zero bytes of common,
1322 since that means "undefined external" in the linker. */
1323 if (size == 0) rounded = 1;
1324 /* Round size up to multiple of BIGGEST_ALIGNMENT bits
1325 so that each uninitialized object starts on such a boundary. */
1326 rounded += (BIGGEST_ALIGNMENT / BITS_PER_UNIT) - 1;
1327 rounded = (rounded / (BIGGEST_ALIGNMENT / BITS_PER_UNIT)
1328 * (BIGGEST_ALIGNMENT / BITS_PER_UNIT));
1329
1330 #ifdef DBX_DEBUGGING_INFO
1331 /* File-scope global variables are output here. */
1332 if (write_symbols == DBX_DEBUG && top_level)
1333 dbxout_symbol (decl, 0);
1334 #endif
1335 #ifdef SDB_DEBUGGING_INFO
1336 if (write_symbols == SDB_DEBUG && top_level
1337 /* Leave initialized global vars for end of compilation;
1338 see comment in compile_file. */
1339 && (TREE_PUBLIC (decl) == 0 || DECL_INITIAL (decl) == 0))
1340 sdbout_symbol (decl, 0);
1341 #endif
1342
1343 /* Don't output any DWARF debugging information for variables here.
1344 In the case of local variables, the information for them is output
1345 when we do our recursive traversal of the tree representation for
1346 the entire containing function. In the case of file-scope variables,
1347 we output information for all of them at the very end of compilation
1348 while we are doing our final traversal of the chain of file-scope
1349 declarations. */
1350
1351 #if 0 /* ??? We should either delete this or add a comment describing what
1352 it was intended to do and why we shouldn't delete it. */
1353 if (flag_shared_data)
1354 data_section ();
1355 #endif
1356
1357 if (TREE_PUBLIC (decl)
1358 #if defined (ASM_OUTPUT_BSS) || defined (ASM_OUTPUT_ALIGNED_BSS)
1359 && DECL_COMMON (decl)
1360 #endif
1361 )
1362 {
1363 #ifdef ASM_OUTPUT_SHARED_COMMON
1364 if (flag_shared_data)
1365 ASM_OUTPUT_SHARED_COMMON (asm_out_file, name, size, rounded);
1366 else
1367 #endif
1368 {
1369 #ifdef ASM_OUTPUT_ALIGNED_DECL_COMMON
1370 ASM_OUTPUT_ALIGNED_DECL_COMMON (asm_out_file, decl, name, size,
1371 DECL_ALIGN (decl));
1372 #else
1373 #ifdef ASM_OUTPUT_ALIGNED_COMMON
1374 ASM_OUTPUT_ALIGNED_COMMON (asm_out_file, name, size,
1375 DECL_ALIGN (decl));
1376 #else
1377 ASM_OUTPUT_COMMON (asm_out_file, name, size, rounded);
1378 #endif
1379 #endif
1380 }
1381 }
1382 #if defined (ASM_OUTPUT_BSS) || defined (ASM_OUTPUT_ALIGNED_BSS)
1383 else if (TREE_PUBLIC (decl))
1384 {
1385 #ifdef ASM_OUTPUT_SHARED_BSS
1386 if (flag_shared_data)
1387 ASM_OUTPUT_SHARED_BSS (asm_out_file, decl, name, size, rounded);
1388 else
1389 #endif
1390 {
1391 #ifdef ASM_OUTPUT_ALIGNED_BSS
1392 ASM_OUTPUT_ALIGNED_BSS (asm_out_file, decl, name, size,
1393 DECL_ALIGN (decl));
1394 #else
1395 ASM_OUTPUT_BSS (asm_out_file, decl, name, size, rounded);
1396 #endif
1397 }
1398 }
1399 #endif /* ASM_OUTPUT_BSS || ASM_OUTPUT_ALIGNED_BSS */
1400 else
1401 {
1402 #ifdef ASM_OUTPUT_SHARED_LOCAL
1403 if (flag_shared_data)
1404 ASM_OUTPUT_SHARED_LOCAL (asm_out_file, name, size, rounded);
1405 else
1406 #endif
1407 {
1408 #ifdef ASM_OUTPUT_ALIGNED_DECL_LOCAL
1409 ASM_OUTPUT_ALIGNED_DECL_LOCAL (asm_out_file, decl, name, size,
1410 DECL_ALIGN (decl));
1411 #else
1412 #ifdef ASM_OUTPUT_ALIGNED_LOCAL
1413 ASM_OUTPUT_ALIGNED_LOCAL (asm_out_file, name, size,
1414 DECL_ALIGN (decl));
1415 #else
1416 ASM_OUTPUT_LOCAL (asm_out_file, name, size, rounded);
1417 #endif
1418 #endif
1419 }
1420 }
1421 goto finish;
1422 }
1423
1424 /* Handle initialized definitions.
1425 Also handle uninitialized global definitions if -fno-common and the
1426 target doesn't support ASM_OUTPUT_BSS. */
1427
1428 /* First make the assembler name(s) global if appropriate. */
1429 if (TREE_PUBLIC (decl) && DECL_NAME (decl))
1430 {
1431 #ifdef ASM_WEAKEN_LABEL
1432 if (DECL_WEAK (decl))
1433 ASM_WEAKEN_LABEL (asm_out_file, name);
1434 else
1435 #endif
1436 ASM_GLOBALIZE_LABEL (asm_out_file, name);
1437 }
1438 #if 0
1439 for (d = equivalents; d; d = TREE_CHAIN (d))
1440 {
1441 tree e = TREE_VALUE (d);
1442 if (TREE_PUBLIC (e) && DECL_NAME (e))
1443 ASM_GLOBALIZE_LABEL (asm_out_file,
1444 XSTR (XEXP (DECL_RTL (e), 0), 0));
1445 }
1446 #endif
1447
1448 /* Output any data that we will need to use the address of. */
1449 if (DECL_INITIAL (decl) == error_mark_node)
1450 reloc = contains_pointers_p (TREE_TYPE (decl));
1451 else if (DECL_INITIAL (decl))
1452 reloc = output_addressed_constants (DECL_INITIAL (decl));
1453
1454 #ifdef ASM_OUTPUT_SECTION_NAME
1455 if (UNIQUE_SECTION_P (decl))
1456 UNIQUE_SECTION (decl, reloc);
1457 #endif
1458
1459 /* Switch to the appropriate section. */
1460 variable_section (decl, reloc);
1461
1462 /* dbxout.c needs to know this. */
1463 if (in_text_section ())
1464 DECL_IN_TEXT_SECTION (decl) = 1;
1465
1466 /* Record current section so we can restore it if dbxout.c clobbers it. */
1467 saved_in_section = in_section;
1468
1469 /* Output the dbx info now that we have chosen the section. */
1470
1471 #ifdef DBX_DEBUGGING_INFO
1472 /* File-scope global variables are output here. */
1473 if (write_symbols == DBX_DEBUG && top_level)
1474 dbxout_symbol (decl, 0);
1475 #endif
1476 #ifdef SDB_DEBUGGING_INFO
1477 if (write_symbols == SDB_DEBUG && top_level
1478 /* Leave initialized global vars for end of compilation;
1479 see comment in compile_file. */
1480 && (TREE_PUBLIC (decl) == 0 || DECL_INITIAL (decl) == 0))
1481 sdbout_symbol (decl, 0);
1482 #endif
1483
1484 /* Don't output any DWARF debugging information for variables here.
1485 In the case of local variables, the information for them is output
1486 when we do our recursive traversal of the tree representation for
1487 the entire containing function. In the case of file-scope variables,
1488 we output information for all of them at the very end of compilation
1489 while we are doing our final traversal of the chain of file-scope
1490 declarations. */
1491
1492 /* If the debugging output changed sections, reselect the section
1493 that's supposed to be selected. */
1494 if (in_section != saved_in_section)
1495 variable_section (decl, reloc);
1496
1497 /* Output the alignment of this data. */
1498 if (align > BITS_PER_UNIT)
1499 ASM_OUTPUT_ALIGN (asm_out_file,
1500 floor_log2 (DECL_ALIGN (decl) / BITS_PER_UNIT));
1501
1502 /* Do any machine/system dependent processing of the object. */
1503 #ifdef ASM_DECLARE_OBJECT_NAME
1504 last_assemble_variable_decl = decl;
1505 ASM_DECLARE_OBJECT_NAME (asm_out_file, name, decl);
1506 #else
1507 /* Standard thing is just output label for the object. */
1508 ASM_OUTPUT_LABEL (asm_out_file, name);
1509 #endif /* ASM_DECLARE_OBJECT_NAME */
1510
1511 if (!dont_output_data)
1512 {
1513 if (DECL_INITIAL (decl))
1514 /* Output the actual data. */
1515 output_constant (DECL_INITIAL (decl), TREE_INT_CST_LOW (size_tree));
1516 else
1517 /* Leave space for it. */
1518 assemble_zeros (TREE_INT_CST_LOW (size_tree));
1519 }
1520
1521 finish:
1522 #ifdef XCOFF_DEBUGGING_INFO
1523 /* Unfortunately, the IBM assembler cannot handle stabx before the actual
1524 declaration. When something like ".stabx "aa:S-2",aa,133,0" is emitted
1525 and `aa' hasn't been output yet, the assembler generates a stab entry with
1526 a value of zero, in addition to creating an unnecessary external entry
1527 for `aa'. Hence, we must postpone dbxout_symbol to here at the end. */
1528
1529 /* File-scope global variables are output here. */
1530 if (write_symbols == XCOFF_DEBUG && top_level)
1531 {
1532 saved_in_section = in_section;
1533
1534 dbxout_symbol (decl, 0);
1535
1536 if (in_section != saved_in_section)
1537 variable_section (decl, reloc);
1538 }
1539 #else
1540 /* There must be a statement after a label. */
1541 ;
1542 #endif
1543 }
1544
1545 /* Return 1 if type TYPE contains any pointers. */
1546
1547 static int
1548 contains_pointers_p (type)
1549 tree type;
1550 {
1551 switch (TREE_CODE (type))
1552 {
1553 case POINTER_TYPE:
1554 case REFERENCE_TYPE:
1555 /* I'm not sure whether OFFSET_TYPE needs this treatment,
1556 so I'll play safe and return 1. */
1557 case OFFSET_TYPE:
1558 return 1;
1559
1560 case RECORD_TYPE:
1561 case UNION_TYPE:
1562 case QUAL_UNION_TYPE:
1563 {
1564 tree fields;
1565 /* For a type that has fields, see if the fields have pointers. */
1566 for (fields = TYPE_FIELDS (type); fields; fields = TREE_CHAIN (fields))
1567 if (TREE_CODE (fields) == FIELD_DECL
1568 && contains_pointers_p (TREE_TYPE (fields)))
1569 return 1;
1570 return 0;
1571 }
1572
1573 case ARRAY_TYPE:
1574 /* An array type contains pointers if its element type does. */
1575 return contains_pointers_p (TREE_TYPE (type));
1576
1577 default:
1578 return 0;
1579 }
1580 }
1581
1582 /* Output something to declare an external symbol to the assembler.
1583 (Most assemblers don't need this, so we normally output nothing.)
1584 Do nothing if DECL is not external. */
1585
1586 void
1587 assemble_external (decl)
1588 tree decl;
1589 {
1590 #ifdef ASM_OUTPUT_EXTERNAL
1591 if (TREE_CODE_CLASS (TREE_CODE (decl)) == 'd'
1592 && DECL_EXTERNAL (decl) && TREE_PUBLIC (decl))
1593 {
1594 rtx rtl = DECL_RTL (decl);
1595
1596 if (GET_CODE (rtl) == MEM && GET_CODE (XEXP (rtl, 0)) == SYMBOL_REF
1597 && ! SYMBOL_REF_USED (XEXP (rtl, 0)))
1598 {
1599 /* Some systems do require some output. */
1600 SYMBOL_REF_USED (XEXP (rtl, 0)) = 1;
1601 ASM_OUTPUT_EXTERNAL (asm_out_file, decl, XSTR (XEXP (rtl, 0), 0));
1602 }
1603 }
1604 #endif
1605 }
1606
1607 /* Similar, for calling a library function FUN. */
1608
1609 void
1610 assemble_external_libcall (fun)
1611 rtx fun;
1612 {
1613 #ifdef ASM_OUTPUT_EXTERNAL_LIBCALL
1614 /* Declare library function name external when first used, if nec. */
1615 if (! SYMBOL_REF_USED (fun))
1616 {
1617 SYMBOL_REF_USED (fun) = 1;
1618 ASM_OUTPUT_EXTERNAL_LIBCALL (asm_out_file, fun);
1619 }
1620 #endif
1621 }
1622
1623 /* Declare the label NAME global. */
1624
1625 void
1626 assemble_global (name)
1627 char *name;
1628 {
1629 ASM_GLOBALIZE_LABEL (asm_out_file, name);
1630 }
1631
1632 /* Assemble a label named NAME. */
1633
1634 void
1635 assemble_label (name)
1636 char *name;
1637 {
1638 ASM_OUTPUT_LABEL (asm_out_file, name);
1639 }
1640
1641 /* Output to FILE a reference to the assembler name of a C-level name NAME.
1642 If NAME starts with a *, the rest of NAME is output verbatim.
1643 Otherwise NAME is transformed in an implementation-defined way
1644 (usually by the addition of an underscore).
1645 Many macros in the tm file are defined to call this function. */
1646
1647 void
1648 assemble_name (file, name)
1649 FILE *file;
1650 char *name;
1651 {
1652 char *real_name;
1653 tree id;
1654
1655 STRIP_NAME_ENCODING (real_name, name);
1656 if (flag_prefix_function_name
1657 && ! bcmp (real_name, CHKR_PREFIX, CHKR_PREFIX_SIZE))
1658 real_name = real_name + CHKR_PREFIX_SIZE;
1659
1660 id = maybe_get_identifier (real_name);
1661 if (id)
1662 TREE_SYMBOL_REFERENCED (id) = 1;
1663
1664 if (name[0] == '*')
1665 fputs (&name[1], file);
1666 else
1667 ASM_OUTPUT_LABELREF (file, name);
1668 }
1669
1670 /* Allocate SIZE bytes writable static space with a gensym name
1671 and return an RTX to refer to its address. */
1672
1673 rtx
1674 assemble_static_space (size)
1675 int size;
1676 {
1677 char name[12];
1678 char *namestring;
1679 rtx x;
1680 #ifndef ASM_OUTPUT_ALIGNED_LOCAL
1681 /* Round size up to multiple of BIGGEST_ALIGNMENT bits
1682 so that each uninitialized object starts on such a boundary. */
1683 int rounded = ((size + (BIGGEST_ALIGNMENT / BITS_PER_UNIT) - 1)
1684 / (BIGGEST_ALIGNMENT / BITS_PER_UNIT)
1685 * (BIGGEST_ALIGNMENT / BITS_PER_UNIT));
1686 #endif
1687
1688 #if 0
1689 if (flag_shared_data)
1690 data_section ();
1691 #endif
1692
1693 ASM_GENERATE_INTERNAL_LABEL (name, "LF", const_labelno);
1694 ++const_labelno;
1695
1696 namestring = (char *) obstack_alloc (saveable_obstack,
1697 strlen (name) + 2);
1698 strcpy (namestring, name);
1699
1700 x = gen_rtx_SYMBOL_REF (Pmode, namestring);
1701
1702 #ifdef ASM_OUTPUT_ALIGNED_DECL_LOCAL
1703 ASM_OUTPUT_ALIGNED_DECL_LOCAL (asm_out_file, NULL_TREE, name, size,
1704 BIGGEST_ALIGNMENT);
1705 #else
1706 #ifdef ASM_OUTPUT_ALIGNED_LOCAL
1707 ASM_OUTPUT_ALIGNED_LOCAL (asm_out_file, name, size, BIGGEST_ALIGNMENT);
1708 #else
1709 ASM_OUTPUT_LOCAL (asm_out_file, name, size, rounded);
1710 #endif
1711 #endif
1712 return x;
1713 }
1714
1715 /* Assemble the static constant template for function entry trampolines.
1716 This is done at most once per compilation.
1717 Returns an RTX for the address of the template. */
1718
1719 #ifdef TRAMPOLINE_TEMPLATE
1720 rtx
1721 assemble_trampoline_template ()
1722 {
1723 char label[256];
1724 char *name;
1725 int align;
1726
1727 /* By default, put trampoline templates in read-only data section. */
1728
1729 #ifdef TRAMPOLINE_SECTION
1730 TRAMPOLINE_SECTION ();
1731 #else
1732 readonly_data_section ();
1733 #endif
1734
1735 /* Write the assembler code to define one. */
1736 align = floor_log2 (TRAMPOLINE_ALIGNMENT / BITS_PER_UNIT);
1737 if (align > 0)
1738 ASM_OUTPUT_ALIGN (asm_out_file, align);
1739
1740 ASM_OUTPUT_INTERNAL_LABEL (asm_out_file, "LTRAMP", 0);
1741 TRAMPOLINE_TEMPLATE (asm_out_file);
1742
1743 /* Record the rtl to refer to it. */
1744 ASM_GENERATE_INTERNAL_LABEL (label, "LTRAMP", 0);
1745 name
1746 = (char *) obstack_copy0 (&permanent_obstack, label, strlen (label));
1747 return gen_rtx_SYMBOL_REF (Pmode, name);
1748 }
1749 #endif
1750 \f
1751 /* Assemble the integer constant X into an object of SIZE bytes.
1752 X must be either a CONST_INT or CONST_DOUBLE.
1753
1754 Return 1 if we were able to output the constant, otherwise 0. If FORCE is
1755 non-zero, abort if we can't output the constant. */
1756
1757 int
1758 assemble_integer (x, size, force)
1759 rtx x;
1760 int size;
1761 int force;
1762 {
1763 /* First try to use the standard 1, 2, 4, 8, and 16 byte
1764 ASM_OUTPUT... macros. */
1765
1766 switch (size)
1767 {
1768 #ifdef ASM_OUTPUT_CHAR
1769 case 1:
1770 ASM_OUTPUT_CHAR (asm_out_file, x);
1771 return 1;
1772 #endif
1773
1774 #ifdef ASM_OUTPUT_SHORT
1775 case 2:
1776 ASM_OUTPUT_SHORT (asm_out_file, x);
1777 return 1;
1778 #endif
1779
1780 #ifdef ASM_OUTPUT_INT
1781 case 4:
1782 ASM_OUTPUT_INT (asm_out_file, x);
1783 return 1;
1784 #endif
1785
1786 #ifdef ASM_OUTPUT_DOUBLE_INT
1787 case 8:
1788 ASM_OUTPUT_DOUBLE_INT (asm_out_file, x);
1789 return 1;
1790 #endif
1791
1792 #ifdef ASM_OUTPUT_QUADRUPLE_INT
1793 case 16:
1794 ASM_OUTPUT_QUADRUPLE_INT (asm_out_file, x);
1795 return 1;
1796 #endif
1797 }
1798
1799 /* If we couldn't do it that way, there are two other possibilities: First,
1800 if the machine can output an explicit byte and this is a 1 byte constant,
1801 we can use ASM_OUTPUT_BYTE. */
1802
1803 #ifdef ASM_OUTPUT_BYTE
1804 if (size == 1 && GET_CODE (x) == CONST_INT)
1805 {
1806 ASM_OUTPUT_BYTE (asm_out_file, INTVAL (x));
1807 return 1;
1808 }
1809 #endif
1810
1811 /* Finally, if SIZE is larger than a single word, try to output the constant
1812 one word at a time. */
1813
1814 if (size > UNITS_PER_WORD)
1815 {
1816 int i;
1817 enum machine_mode mode
1818 = mode_for_size (size * BITS_PER_UNIT, MODE_INT, 0);
1819 rtx word;
1820
1821 for (i = 0; i < size / UNITS_PER_WORD; i++)
1822 {
1823 word = operand_subword (x, i, 0, mode);
1824
1825 if (word == 0)
1826 break;
1827
1828 if (! assemble_integer (word, UNITS_PER_WORD, 0))
1829 break;
1830 }
1831
1832 if (i == size / UNITS_PER_WORD)
1833 return 1;
1834 /* If we output at least one word and then could not finish,
1835 there is no valid way to continue. */
1836 if (i > 0)
1837 abort ();
1838 }
1839
1840 if (force)
1841 abort ();
1842
1843 return 0;
1844 }
1845 \f
1846 /* Assemble the floating-point constant D into an object of size MODE. */
1847
1848 void
1849 assemble_real (d, mode)
1850 REAL_VALUE_TYPE d;
1851 enum machine_mode mode;
1852 {
1853 jmp_buf output_constant_handler;
1854
1855 if (setjmp (output_constant_handler))
1856 {
1857 error ("floating point trap outputting a constant");
1858 #ifdef REAL_IS_NOT_DOUBLE
1859 bzero ((char *) &d, sizeof d);
1860 d = dconst0;
1861 #else
1862 d = 0;
1863 #endif
1864 }
1865
1866 set_float_handler (output_constant_handler);
1867
1868 switch (mode)
1869 {
1870 #ifdef ASM_OUTPUT_BYTE_FLOAT
1871 case QFmode:
1872 ASM_OUTPUT_BYTE_FLOAT (asm_out_file, d);
1873 break;
1874 #endif
1875 #ifdef ASM_OUTPUT_SHORT_FLOAT
1876 case HFmode:
1877 ASM_OUTPUT_SHORT_FLOAT (asm_out_file, d);
1878 break;
1879 #endif
1880 #ifdef ASM_OUTPUT_THREE_QUARTER_FLOAT
1881 case TQFmode:
1882 ASM_OUTPUT_THREE_QUARTER_FLOAT (asm_out_file, d);
1883 break;
1884 #endif
1885 #ifdef ASM_OUTPUT_FLOAT
1886 case SFmode:
1887 ASM_OUTPUT_FLOAT (asm_out_file, d);
1888 break;
1889 #endif
1890
1891 #ifdef ASM_OUTPUT_DOUBLE
1892 case DFmode:
1893 ASM_OUTPUT_DOUBLE (asm_out_file, d);
1894 break;
1895 #endif
1896
1897 #ifdef ASM_OUTPUT_LONG_DOUBLE
1898 case XFmode:
1899 case TFmode:
1900 ASM_OUTPUT_LONG_DOUBLE (asm_out_file, d);
1901 break;
1902 #endif
1903
1904 default:
1905 abort ();
1906 }
1907
1908 set_float_handler (NULL_PTR);
1909 }
1910 \f
1911 /* Here we combine duplicate floating constants to make
1912 CONST_DOUBLE rtx's, and force those out to memory when necessary. */
1913
1914 /* Chain of all CONST_DOUBLE rtx's constructed for the current function.
1915 They are chained through the CONST_DOUBLE_CHAIN.
1916 A CONST_DOUBLE rtx has CONST_DOUBLE_MEM != cc0_rtx iff it is on this chain.
1917 In that case, CONST_DOUBLE_MEM is either a MEM,
1918 or const0_rtx if no MEM has been made for this CONST_DOUBLE yet.
1919
1920 (CONST_DOUBLE_MEM is used only for top-level functions.
1921 See force_const_mem for explanation.) */
1922
1923 static rtx const_double_chain;
1924
1925 /* Return a CONST_DOUBLE or CONST_INT for a value specified as a pair of ints.
1926 For an integer, I0 is the low-order word and I1 is the high-order word.
1927 For a real number, I0 is the word with the low address
1928 and I1 is the word with the high address. */
1929
1930 rtx
1931 immed_double_const (i0, i1, mode)
1932 HOST_WIDE_INT i0, i1;
1933 enum machine_mode mode;
1934 {
1935 register rtx r;
1936
1937 if (GET_MODE_CLASS (mode) == MODE_INT
1938 || GET_MODE_CLASS (mode) == MODE_PARTIAL_INT)
1939 {
1940 /* We clear out all bits that don't belong in MODE, unless they and our
1941 sign bit are all one. So we get either a reasonable negative value
1942 or a reasonable unsigned value for this mode. */
1943 int width = GET_MODE_BITSIZE (mode);
1944 if (width < HOST_BITS_PER_WIDE_INT
1945 && ((i0 & ((HOST_WIDE_INT) (-1) << (width - 1)))
1946 != ((HOST_WIDE_INT) (-1) << (width - 1))))
1947 i0 &= ((HOST_WIDE_INT) 1 << width) - 1, i1 = 0;
1948 else if (width == HOST_BITS_PER_WIDE_INT
1949 && ! (i1 == ~0 && i0 < 0))
1950 i1 = 0;
1951 else if (width > 2 * HOST_BITS_PER_WIDE_INT)
1952 /* We cannot represent this value as a constant. */
1953 abort ();
1954
1955 /* If this would be an entire word for the target, but is not for
1956 the host, then sign-extend on the host so that the number will look
1957 the same way on the host that it would on the target.
1958
1959 For example, when building a 64 bit alpha hosted 32 bit sparc
1960 targeted compiler, then we want the 32 bit unsigned value -1 to be
1961 represented as a 64 bit value -1, and not as 0x00000000ffffffff.
1962 The later confuses the sparc backend. */
1963
1964 if (BITS_PER_WORD < HOST_BITS_PER_WIDE_INT && BITS_PER_WORD == width
1965 && (i0 & ((HOST_WIDE_INT) 1 << (width - 1))))
1966 i0 |= ((HOST_WIDE_INT) (-1) << width);
1967
1968 /* If MODE fits within HOST_BITS_PER_WIDE_INT, always use a CONST_INT.
1969
1970 ??? Strictly speaking, this is wrong if we create a CONST_INT
1971 for a large unsigned constant with the size of MODE being
1972 HOST_BITS_PER_WIDE_INT and later try to interpret that constant in a
1973 wider mode. In that case we will mis-interpret it as a negative
1974 number.
1975
1976 Unfortunately, the only alternative is to make a CONST_DOUBLE
1977 for any constant in any mode if it is an unsigned constant larger
1978 than the maximum signed integer in an int on the host. However,
1979 doing this will break everyone that always expects to see a CONST_INT
1980 for SImode and smaller.
1981
1982 We have always been making CONST_INTs in this case, so nothing new
1983 is being broken. */
1984
1985 if (width <= HOST_BITS_PER_WIDE_INT)
1986 i1 = (i0 < 0) ? ~(HOST_WIDE_INT) 0 : 0;
1987
1988 /* If this integer fits in one word, return a CONST_INT. */
1989 if ((i1 == 0 && i0 >= 0)
1990 || (i1 == ~0 && i0 < 0))
1991 return GEN_INT (i0);
1992
1993 /* We use VOIDmode for integers. */
1994 mode = VOIDmode;
1995 }
1996
1997 /* Search the chain for an existing CONST_DOUBLE with the right value.
1998 If one is found, return it. */
1999
2000 for (r = const_double_chain; r; r = CONST_DOUBLE_CHAIN (r))
2001 if (CONST_DOUBLE_LOW (r) == i0 && CONST_DOUBLE_HIGH (r) == i1
2002 && GET_MODE (r) == mode)
2003 return r;
2004
2005 /* No; make a new one and add it to the chain.
2006
2007 We may be called by an optimizer which may be discarding any memory
2008 allocated during its processing (such as combine and loop). However,
2009 we will be leaving this constant on the chain, so we cannot tolerate
2010 freed memory. So switch to saveable_obstack for this allocation
2011 and then switch back if we were in current_obstack. */
2012
2013 push_obstacks_nochange ();
2014 rtl_in_saveable_obstack ();
2015 r = gen_rtx_CONST_DOUBLE (mode, NULL_RTX, i0, i1);
2016 pop_obstacks ();
2017
2018 /* Don't touch const_double_chain in nested function; see force_const_mem.
2019 Also, don't touch it if not inside any function. */
2020 if (outer_function_chain == 0 && current_function_decl != 0)
2021 {
2022 CONST_DOUBLE_CHAIN (r) = const_double_chain;
2023 const_double_chain = r;
2024 }
2025
2026 /* Store const0_rtx in mem-slot since this CONST_DOUBLE is on the chain.
2027 Actual use of mem-slot is only through force_const_mem. */
2028
2029 CONST_DOUBLE_MEM (r) = const0_rtx;
2030
2031 return r;
2032 }
2033
2034 /* Return a CONST_DOUBLE for a specified `double' value
2035 and machine mode. */
2036
2037 rtx
2038 immed_real_const_1 (d, mode)
2039 REAL_VALUE_TYPE d;
2040 enum machine_mode mode;
2041 {
2042 union real_extract u;
2043 register rtx r;
2044
2045 /* Get the desired `double' value as a sequence of ints
2046 since that is how they are stored in a CONST_DOUBLE. */
2047
2048 u.d = d;
2049
2050 /* Detect special cases. */
2051
2052 if (REAL_VALUES_IDENTICAL (dconst0, d))
2053 return CONST0_RTX (mode);
2054 /* Check for NaN first, because some ports (specifically the i386) do not
2055 emit correct ieee-fp code by default, and thus will generate a core
2056 dump here if we pass a NaN to REAL_VALUES_EQUAL and if REAL_VALUES_EQUAL
2057 does a floating point comparison. */
2058 else if (! REAL_VALUE_ISNAN (d) && REAL_VALUES_EQUAL (dconst1, d))
2059 return CONST1_RTX (mode);
2060
2061 if (sizeof u == 2 * sizeof (HOST_WIDE_INT))
2062 return immed_double_const (u.i[0], u.i[1], mode);
2063
2064 /* The rest of this function handles the case where
2065 a float value requires more than 2 ints of space.
2066 It will be deleted as dead code on machines that don't need it. */
2067
2068 /* Search the chain for an existing CONST_DOUBLE with the right value.
2069 If one is found, return it. */
2070
2071 for (r = const_double_chain; r; r = CONST_DOUBLE_CHAIN (r))
2072 if (! bcmp ((char *) &CONST_DOUBLE_LOW (r), (char *) &u, sizeof u)
2073 && GET_MODE (r) == mode)
2074 return r;
2075
2076 /* No; make a new one and add it to the chain.
2077
2078 We may be called by an optimizer which may be discarding any memory
2079 allocated during its processing (such as combine and loop). However,
2080 we will be leaving this constant on the chain, so we cannot tolerate
2081 freed memory. So switch to saveable_obstack for this allocation
2082 and then switch back if we were in current_obstack. */
2083
2084 push_obstacks_nochange ();
2085 rtl_in_saveable_obstack ();
2086 r = rtx_alloc (CONST_DOUBLE);
2087 PUT_MODE (r, mode);
2088 bcopy ((char *) &u, (char *) &CONST_DOUBLE_LOW (r), sizeof u);
2089 pop_obstacks ();
2090
2091 /* Don't touch const_double_chain in nested function; see force_const_mem.
2092 Also, don't touch it if not inside any function. */
2093 if (outer_function_chain == 0 && current_function_decl != 0)
2094 {
2095 CONST_DOUBLE_CHAIN (r) = const_double_chain;
2096 const_double_chain = r;
2097 }
2098
2099 /* Store const0_rtx in CONST_DOUBLE_MEM since this CONST_DOUBLE is on the
2100 chain, but has not been allocated memory. Actual use of CONST_DOUBLE_MEM
2101 is only through force_const_mem. */
2102
2103 CONST_DOUBLE_MEM (r) = const0_rtx;
2104
2105 return r;
2106 }
2107
2108 /* Return a CONST_DOUBLE rtx for a value specified by EXP,
2109 which must be a REAL_CST tree node. */
2110
2111 rtx
2112 immed_real_const (exp)
2113 tree exp;
2114 {
2115 return immed_real_const_1 (TREE_REAL_CST (exp), TYPE_MODE (TREE_TYPE (exp)));
2116 }
2117
2118 /* At the end of a function, forget the memory-constants
2119 previously made for CONST_DOUBLEs. Mark them as not on real_constant_chain.
2120 Also clear out real_constant_chain and clear out all the chain-pointers. */
2121
2122 void
2123 clear_const_double_mem ()
2124 {
2125 register rtx r, next;
2126
2127 /* Don't touch CONST_DOUBLE_MEM for nested functions.
2128 See force_const_mem for explanation. */
2129 if (outer_function_chain != 0)
2130 return;
2131
2132 for (r = const_double_chain; r; r = next)
2133 {
2134 next = CONST_DOUBLE_CHAIN (r);
2135 CONST_DOUBLE_CHAIN (r) = 0;
2136 CONST_DOUBLE_MEM (r) = cc0_rtx;
2137 }
2138 const_double_chain = 0;
2139 }
2140 \f
2141 /* Given an expression EXP with a constant value,
2142 reduce it to the sum of an assembler symbol and an integer.
2143 Store them both in the structure *VALUE.
2144 Abort if EXP does not reduce. */
2145
2146 struct addr_const
2147 {
2148 rtx base;
2149 HOST_WIDE_INT offset;
2150 };
2151
2152 static void
2153 decode_addr_const (exp, value)
2154 tree exp;
2155 struct addr_const *value;
2156 {
2157 register tree target = TREE_OPERAND (exp, 0);
2158 register int offset = 0;
2159 register rtx x;
2160
2161 while (1)
2162 {
2163 if (TREE_CODE (target) == COMPONENT_REF
2164 && (TREE_CODE (DECL_FIELD_BITPOS (TREE_OPERAND (target, 1)))
2165 == INTEGER_CST))
2166 {
2167 offset += TREE_INT_CST_LOW (DECL_FIELD_BITPOS (TREE_OPERAND (target, 1))) / BITS_PER_UNIT;
2168 target = TREE_OPERAND (target, 0);
2169 }
2170 else if (TREE_CODE (target) == ARRAY_REF)
2171 {
2172 if (TREE_CODE (TREE_OPERAND (target, 1)) != INTEGER_CST
2173 || TREE_CODE (TYPE_SIZE (TREE_TYPE (target))) != INTEGER_CST)
2174 abort ();
2175 offset += ((TREE_INT_CST_LOW (TYPE_SIZE (TREE_TYPE (target)))
2176 * TREE_INT_CST_LOW (TREE_OPERAND (target, 1)))
2177 / BITS_PER_UNIT);
2178 target = TREE_OPERAND (target, 0);
2179 }
2180 else
2181 break;
2182 }
2183
2184 switch (TREE_CODE (target))
2185 {
2186 case VAR_DECL:
2187 case FUNCTION_DECL:
2188 x = DECL_RTL (target);
2189 break;
2190
2191 case LABEL_DECL:
2192 x = gen_rtx_MEM (FUNCTION_MODE,
2193 gen_rtx_LABEL_REF (VOIDmode,
2194 label_rtx (TREE_OPERAND (exp, 0))));
2195 break;
2196
2197 case REAL_CST:
2198 case STRING_CST:
2199 case COMPLEX_CST:
2200 case CONSTRUCTOR:
2201 case INTEGER_CST:
2202 x = TREE_CST_RTL (target);
2203 break;
2204
2205 default:
2206 abort ();
2207 }
2208
2209 if (GET_CODE (x) != MEM)
2210 abort ();
2211 x = XEXP (x, 0);
2212
2213 value->base = x;
2214 value->offset = offset;
2215 }
2216 \f
2217 /* Uniquize all constants that appear in memory.
2218 Each constant in memory thus far output is recorded
2219 in `const_hash_table' with a `struct constant_descriptor'
2220 that contains a polish representation of the value of
2221 the constant.
2222
2223 We cannot store the trees in the hash table
2224 because the trees may be temporary. */
2225
2226 struct constant_descriptor
2227 {
2228 struct constant_descriptor *next;
2229 char *label;
2230 char contents[1];
2231 };
2232
2233 #define HASHBITS 30
2234 #define MAX_HASH_TABLE 1009
2235 static struct constant_descriptor *const_hash_table[MAX_HASH_TABLE];
2236
2237 /* Compute a hash code for a constant expression. */
2238
2239 static int
2240 const_hash (exp)
2241 tree exp;
2242 {
2243 register char *p;
2244 register int len, hi, i;
2245 register enum tree_code code = TREE_CODE (exp);
2246
2247 /* Either set P and LEN to the address and len of something to hash and
2248 exit the switch or return a value. */
2249
2250 switch (code)
2251 {
2252 case INTEGER_CST:
2253 p = (char *) &TREE_INT_CST_LOW (exp);
2254 len = 2 * sizeof TREE_INT_CST_LOW (exp);
2255 break;
2256
2257 case REAL_CST:
2258 p = (char *) &TREE_REAL_CST (exp);
2259 len = sizeof TREE_REAL_CST (exp);
2260 break;
2261
2262 case STRING_CST:
2263 p = TREE_STRING_POINTER (exp);
2264 len = TREE_STRING_LENGTH (exp);
2265 break;
2266
2267 case COMPLEX_CST:
2268 return (const_hash (TREE_REALPART (exp)) * 5
2269 + const_hash (TREE_IMAGPART (exp)));
2270
2271 case CONSTRUCTOR:
2272 if (TREE_CODE (TREE_TYPE (exp)) == SET_TYPE)
2273 {
2274 len = int_size_in_bytes (TREE_TYPE (exp));
2275 p = (char *) alloca (len);
2276 get_set_constructor_bytes (exp, (unsigned char *) p, len);
2277 break;
2278 }
2279 else
2280 {
2281 register tree link;
2282
2283 /* For record type, include the type in the hashing.
2284 We do not do so for array types
2285 because (1) the sizes of the elements are sufficient
2286 and (2) distinct array types can have the same constructor.
2287 Instead, we include the array size because the constructor could
2288 be shorter. */
2289 if (TREE_CODE (TREE_TYPE (exp)) == RECORD_TYPE)
2290 hi = ((unsigned long) TREE_TYPE (exp) & ((1 << HASHBITS) - 1))
2291 % MAX_HASH_TABLE;
2292 else
2293 hi = ((5 + int_size_in_bytes (TREE_TYPE (exp)))
2294 & ((1 << HASHBITS) - 1)) % MAX_HASH_TABLE;
2295
2296 for (link = CONSTRUCTOR_ELTS (exp); link; link = TREE_CHAIN (link))
2297 if (TREE_VALUE (link))
2298 hi
2299 = (hi * 603 + const_hash (TREE_VALUE (link))) % MAX_HASH_TABLE;
2300
2301 return hi;
2302 }
2303
2304 case ADDR_EXPR:
2305 {
2306 struct addr_const value;
2307
2308 decode_addr_const (exp, &value);
2309 if (GET_CODE (value.base) == SYMBOL_REF)
2310 {
2311 /* Don't hash the address of the SYMBOL_REF;
2312 only use the offset and the symbol name. */
2313 hi = value.offset;
2314 p = XSTR (value.base, 0);
2315 for (i = 0; p[i] != 0; i++)
2316 hi = ((hi * 613) + (unsigned) (p[i]));
2317 }
2318 else if (GET_CODE (value.base) == LABEL_REF)
2319 hi = value.offset + CODE_LABEL_NUMBER (XEXP (value.base, 0)) * 13;
2320
2321 hi &= (1 << HASHBITS) - 1;
2322 hi %= MAX_HASH_TABLE;
2323 }
2324 return hi;
2325
2326 case PLUS_EXPR:
2327 case MINUS_EXPR:
2328 return (const_hash (TREE_OPERAND (exp, 0)) * 9
2329 + const_hash (TREE_OPERAND (exp, 1)));
2330
2331 case NOP_EXPR:
2332 case CONVERT_EXPR:
2333 case NON_LVALUE_EXPR:
2334 return const_hash (TREE_OPERAND (exp, 0)) * 7 + 2;
2335
2336 default:
2337 abort ();
2338 }
2339
2340 /* Compute hashing function */
2341 hi = len;
2342 for (i = 0; i < len; i++)
2343 hi = ((hi * 613) + (unsigned) (p[i]));
2344
2345 hi &= (1 << HASHBITS) - 1;
2346 hi %= MAX_HASH_TABLE;
2347 return hi;
2348 }
2349 \f
2350 /* Compare a constant expression EXP with a constant-descriptor DESC.
2351 Return 1 if DESC describes a constant with the same value as EXP. */
2352
2353 static int
2354 compare_constant (exp, desc)
2355 tree exp;
2356 struct constant_descriptor *desc;
2357 {
2358 return 0 != compare_constant_1 (exp, desc->contents);
2359 }
2360
2361 /* Compare constant expression EXP with a substring P of a constant descriptor.
2362 If they match, return a pointer to the end of the substring matched.
2363 If they do not match, return 0.
2364
2365 Since descriptors are written in polish prefix notation,
2366 this function can be used recursively to test one operand of EXP
2367 against a subdescriptor, and if it succeeds it returns the
2368 address of the subdescriptor for the next operand. */
2369
2370 static char *
2371 compare_constant_1 (exp, p)
2372 tree exp;
2373 char *p;
2374 {
2375 register char *strp;
2376 register int len;
2377 register enum tree_code code = TREE_CODE (exp);
2378
2379 if (code != (enum tree_code) *p++)
2380 return 0;
2381
2382 /* Either set STRP, P and LEN to pointers and length to compare and exit the
2383 switch, or return the result of the comparison. */
2384
2385 switch (code)
2386 {
2387 case INTEGER_CST:
2388 /* Integer constants are the same only if the same width of type. */
2389 if (*p++ != TYPE_PRECISION (TREE_TYPE (exp)))
2390 return 0;
2391
2392 strp = (char *) &TREE_INT_CST_LOW (exp);
2393 len = 2 * sizeof TREE_INT_CST_LOW (exp);
2394 break;
2395
2396 case REAL_CST:
2397 /* Real constants are the same only if the same width of type. */
2398 if (*p++ != TYPE_PRECISION (TREE_TYPE (exp)))
2399 return 0;
2400
2401 strp = (char *) &TREE_REAL_CST (exp);
2402 len = sizeof TREE_REAL_CST (exp);
2403 break;
2404
2405 case STRING_CST:
2406 if (flag_writable_strings)
2407 return 0;
2408
2409 if (*p++ != TYPE_MODE (TREE_TYPE (exp)))
2410 return 0;
2411
2412 strp = TREE_STRING_POINTER (exp);
2413 len = TREE_STRING_LENGTH (exp);
2414 if (bcmp ((char *) &TREE_STRING_LENGTH (exp), p,
2415 sizeof TREE_STRING_LENGTH (exp)))
2416 return 0;
2417
2418 p += sizeof TREE_STRING_LENGTH (exp);
2419 break;
2420
2421 case COMPLEX_CST:
2422 p = compare_constant_1 (TREE_REALPART (exp), p);
2423 if (p == 0)
2424 return 0;
2425
2426 return compare_constant_1 (TREE_IMAGPART (exp), p);
2427
2428 case CONSTRUCTOR:
2429 if (TREE_CODE (TREE_TYPE (exp)) == SET_TYPE)
2430 {
2431 int xlen = len = int_size_in_bytes (TREE_TYPE (exp));
2432
2433 strp = (char *) alloca (len);
2434 get_set_constructor_bytes (exp, (unsigned char *) strp, len);
2435 if (bcmp ((char *) &xlen, p, sizeof xlen))
2436 return 0;
2437
2438 p += sizeof xlen;
2439 break;
2440 }
2441 else
2442 {
2443 register tree link;
2444 int length = list_length (CONSTRUCTOR_ELTS (exp));
2445 tree type;
2446 int have_purpose = 0;
2447
2448 for (link = CONSTRUCTOR_ELTS (exp); link; link = TREE_CHAIN (link))
2449 if (TREE_PURPOSE (link))
2450 have_purpose = 1;
2451
2452 if (bcmp ((char *) &length, p, sizeof length))
2453 return 0;
2454
2455 p += sizeof length;
2456
2457 /* For record constructors, insist that the types match.
2458 For arrays, just verify both constructors are for arrays.
2459 Then insist that either both or none have any TREE_PURPOSE
2460 values. */
2461 if (TREE_CODE (TREE_TYPE (exp)) == RECORD_TYPE)
2462 type = TREE_TYPE (exp);
2463 else
2464 type = 0;
2465
2466 if (bcmp ((char *) &type, p, sizeof type))
2467 return 0;
2468
2469 p += sizeof type;
2470
2471 if (bcmp ((char *) &have_purpose, p, sizeof have_purpose))
2472 return 0;
2473
2474 p += sizeof have_purpose;
2475
2476 /* For arrays, insist that the size in bytes match. */
2477 if (TREE_CODE (TREE_TYPE (exp)) == ARRAY_TYPE)
2478 {
2479 HOST_WIDE_INT size = int_size_in_bytes (TREE_TYPE (exp));
2480
2481 if (bcmp ((char *) &size, p, sizeof size))
2482 return 0;
2483
2484 p += sizeof size;
2485 }
2486
2487 for (link = CONSTRUCTOR_ELTS (exp); link; link = TREE_CHAIN (link))
2488 {
2489 if (TREE_VALUE (link))
2490 {
2491 if ((p = compare_constant_1 (TREE_VALUE (link), p)) == 0)
2492 return 0;
2493 }
2494 else
2495 {
2496 tree zero = 0;
2497
2498 if (bcmp ((char *) &zero, p, sizeof zero))
2499 return 0;
2500
2501 p += sizeof zero;
2502 }
2503
2504 if (TREE_PURPOSE (link)
2505 && TREE_CODE (TREE_PURPOSE (link)) == FIELD_DECL)
2506 {
2507 if (bcmp ((char *) &TREE_PURPOSE (link), p,
2508 sizeof TREE_PURPOSE (link)))
2509 return 0;
2510
2511 p += sizeof TREE_PURPOSE (link);
2512 }
2513 else if (TREE_PURPOSE (link))
2514 {
2515 if ((p = compare_constant_1 (TREE_PURPOSE (link), p)) == 0)
2516 return 0;
2517 }
2518 else if (have_purpose)
2519 {
2520 int zero = 0;
2521
2522 if (bcmp ((char *) &zero, p, sizeof zero))
2523 return 0;
2524
2525 p += sizeof zero;
2526 }
2527 }
2528
2529 return p;
2530 }
2531
2532 case ADDR_EXPR:
2533 {
2534 struct addr_const value;
2535
2536 decode_addr_const (exp, &value);
2537 strp = (char *) &value.offset;
2538 len = sizeof value.offset;
2539 /* Compare the offset. */
2540 while (--len >= 0)
2541 if (*p++ != *strp++)
2542 return 0;
2543
2544 /* Compare symbol name. */
2545 strp = XSTR (value.base, 0);
2546 len = strlen (strp) + 1;
2547 }
2548 break;
2549
2550 case PLUS_EXPR:
2551 case MINUS_EXPR:
2552 p = compare_constant_1 (TREE_OPERAND (exp, 0), p);
2553 if (p == 0)
2554 return 0;
2555
2556 return compare_constant_1 (TREE_OPERAND (exp, 1), p);
2557
2558 case NOP_EXPR:
2559 case CONVERT_EXPR:
2560 case NON_LVALUE_EXPR:
2561 return compare_constant_1 (TREE_OPERAND (exp, 0), p);
2562
2563 default:
2564 abort ();
2565 }
2566
2567 /* Compare constant contents. */
2568 while (--len >= 0)
2569 if (*p++ != *strp++)
2570 return 0;
2571
2572 return p;
2573 }
2574 \f
2575 /* Construct a constant descriptor for the expression EXP.
2576 It is up to the caller to enter the descriptor in the hash table. */
2577
2578 static struct constant_descriptor *
2579 record_constant (exp)
2580 tree exp;
2581 {
2582 struct constant_descriptor *next = 0;
2583 char *label = 0;
2584
2585 /* Make a struct constant_descriptor. The first two pointers will
2586 be filled in later. Here we just leave space for them. */
2587
2588 obstack_grow (&permanent_obstack, (char *) &next, sizeof next);
2589 obstack_grow (&permanent_obstack, (char *) &label, sizeof label);
2590 record_constant_1 (exp);
2591 return (struct constant_descriptor *) obstack_finish (&permanent_obstack);
2592 }
2593
2594 /* Add a description of constant expression EXP
2595 to the object growing in `permanent_obstack'.
2596 No need to return its address; the caller will get that
2597 from the obstack when the object is complete. */
2598
2599 static void
2600 record_constant_1 (exp)
2601 tree exp;
2602 {
2603 register char *strp;
2604 register int len;
2605 register enum tree_code code = TREE_CODE (exp);
2606
2607 obstack_1grow (&permanent_obstack, (unsigned int) code);
2608
2609 switch (code)
2610 {
2611 case INTEGER_CST:
2612 obstack_1grow (&permanent_obstack, TYPE_PRECISION (TREE_TYPE (exp)));
2613 strp = (char *) &TREE_INT_CST_LOW (exp);
2614 len = 2 * sizeof TREE_INT_CST_LOW (exp);
2615 break;
2616
2617 case REAL_CST:
2618 obstack_1grow (&permanent_obstack, TYPE_PRECISION (TREE_TYPE (exp)));
2619 strp = (char *) &TREE_REAL_CST (exp);
2620 len = sizeof TREE_REAL_CST (exp);
2621 break;
2622
2623 case STRING_CST:
2624 if (flag_writable_strings)
2625 return;
2626
2627 obstack_1grow (&permanent_obstack, TYPE_MODE (TREE_TYPE (exp)));
2628 strp = TREE_STRING_POINTER (exp);
2629 len = TREE_STRING_LENGTH (exp);
2630 obstack_grow (&permanent_obstack, (char *) &TREE_STRING_LENGTH (exp),
2631 sizeof TREE_STRING_LENGTH (exp));
2632 break;
2633
2634 case COMPLEX_CST:
2635 record_constant_1 (TREE_REALPART (exp));
2636 record_constant_1 (TREE_IMAGPART (exp));
2637 return;
2638
2639 case CONSTRUCTOR:
2640 if (TREE_CODE (TREE_TYPE (exp)) == SET_TYPE)
2641 {
2642 int nbytes = int_size_in_bytes (TREE_TYPE (exp));
2643 obstack_grow (&permanent_obstack, &nbytes, sizeof (nbytes));
2644 obstack_blank (&permanent_obstack, nbytes);
2645 get_set_constructor_bytes
2646 (exp, (unsigned char *) permanent_obstack.next_free-nbytes,
2647 nbytes);
2648 return;
2649 }
2650 else
2651 {
2652 register tree link;
2653 int length = list_length (CONSTRUCTOR_ELTS (exp));
2654 tree type;
2655 int have_purpose = 0;
2656
2657 for (link = CONSTRUCTOR_ELTS (exp); link; link = TREE_CHAIN (link))
2658 if (TREE_PURPOSE (link))
2659 have_purpose = 1;
2660
2661 obstack_grow (&permanent_obstack, (char *) &length, sizeof length);
2662
2663 /* For record constructors, insist that the types match.
2664 For arrays, just verify both constructors are for arrays.
2665 Then insist that either both or none have any TREE_PURPOSE
2666 values. */
2667 if (TREE_CODE (TREE_TYPE (exp)) == RECORD_TYPE)
2668 type = TREE_TYPE (exp);
2669 else
2670 type = 0;
2671 obstack_grow (&permanent_obstack, (char *) &type, sizeof type);
2672 obstack_grow (&permanent_obstack, (char *) &have_purpose,
2673 sizeof have_purpose);
2674
2675 /* For arrays, insist that the size in bytes match. */
2676 if (TREE_CODE (TREE_TYPE (exp)) == ARRAY_TYPE)
2677 {
2678 HOST_WIDE_INT size = int_size_in_bytes (TREE_TYPE (exp));
2679 obstack_grow (&permanent_obstack, (char *) &size, sizeof size);
2680 }
2681
2682 for (link = CONSTRUCTOR_ELTS (exp); link; link = TREE_CHAIN (link))
2683 {
2684 if (TREE_VALUE (link))
2685 record_constant_1 (TREE_VALUE (link));
2686 else
2687 {
2688 tree zero = 0;
2689
2690 obstack_grow (&permanent_obstack,
2691 (char *) &zero, sizeof zero);
2692 }
2693
2694 if (TREE_PURPOSE (link)
2695 && TREE_CODE (TREE_PURPOSE (link)) == FIELD_DECL)
2696 obstack_grow (&permanent_obstack,
2697 (char *) &TREE_PURPOSE (link),
2698 sizeof TREE_PURPOSE (link));
2699 else if (TREE_PURPOSE (link))
2700 record_constant_1 (TREE_PURPOSE (link));
2701 else if (have_purpose)
2702 {
2703 int zero = 0;
2704
2705 obstack_grow (&permanent_obstack,
2706 (char *) &zero, sizeof zero);
2707 }
2708 }
2709 }
2710 return;
2711
2712 case ADDR_EXPR:
2713 {
2714 struct addr_const value;
2715
2716 decode_addr_const (exp, &value);
2717 /* Record the offset. */
2718 obstack_grow (&permanent_obstack,
2719 (char *) &value.offset, sizeof value.offset);
2720 /* Record the symbol name. */
2721 obstack_grow (&permanent_obstack, XSTR (value.base, 0),
2722 strlen (XSTR (value.base, 0)) + 1);
2723 }
2724 return;
2725
2726 case PLUS_EXPR:
2727 case MINUS_EXPR:
2728 record_constant_1 (TREE_OPERAND (exp, 0));
2729 record_constant_1 (TREE_OPERAND (exp, 1));
2730 return;
2731
2732 case NOP_EXPR:
2733 case CONVERT_EXPR:
2734 case NON_LVALUE_EXPR:
2735 record_constant_1 (TREE_OPERAND (exp, 0));
2736 return;
2737
2738 default:
2739 abort ();
2740 }
2741
2742 /* Record constant contents. */
2743 obstack_grow (&permanent_obstack, strp, len);
2744 }
2745 \f
2746 /* Record a list of constant expressions that were passed to
2747 output_constant_def but that could not be output right away. */
2748
2749 struct deferred_constant
2750 {
2751 struct deferred_constant *next;
2752 tree exp;
2753 int reloc;
2754 int labelno;
2755 };
2756
2757 static struct deferred_constant *deferred_constants;
2758
2759 /* Another list of constants which should be output after the
2760 function. */
2761 static struct deferred_constant *after_function_constants;
2762
2763 /* Nonzero means defer output of addressed subconstants
2764 (i.e., those for which output_constant_def is called.) */
2765 static int defer_addressed_constants_flag;
2766
2767 /* Start deferring output of subconstants. */
2768
2769 void
2770 defer_addressed_constants ()
2771 {
2772 defer_addressed_constants_flag++;
2773 }
2774
2775 /* Stop deferring output of subconstants,
2776 and output now all those that have been deferred. */
2777
2778 void
2779 output_deferred_addressed_constants ()
2780 {
2781 struct deferred_constant *p, *next;
2782
2783 defer_addressed_constants_flag--;
2784
2785 if (defer_addressed_constants_flag > 0)
2786 return;
2787
2788 for (p = deferred_constants; p; p = next)
2789 {
2790 output_constant_def_contents (p->exp, p->reloc, p->labelno);
2791 next = p->next;
2792 free (p);
2793 }
2794
2795 deferred_constants = 0;
2796 }
2797
2798 /* Output any constants which should appear after a function. */
2799
2800 static void
2801 output_after_function_constants ()
2802 {
2803 struct deferred_constant *p, *next;
2804
2805 for (p = after_function_constants; p; p = next)
2806 {
2807 output_constant_def_contents (p->exp, p->reloc, p->labelno);
2808 next = p->next;
2809 free (p);
2810 }
2811
2812 after_function_constants = 0;
2813 }
2814
2815 /* Make a copy of the whole tree structure for a constant.
2816 This handles the same types of nodes that compare_constant
2817 and record_constant handle. */
2818
2819 static tree
2820 copy_constant (exp)
2821 tree exp;
2822 {
2823 switch (TREE_CODE (exp))
2824 {
2825 case ADDR_EXPR:
2826 /* For ADDR_EXPR, we do not want to copy the decl whose address
2827 is requested. We do want to copy constants though. */
2828 if (TREE_CODE_CLASS (TREE_CODE (TREE_OPERAND (exp, 0))) == 'c')
2829 return build1 (TREE_CODE (exp), TREE_TYPE (exp),
2830 copy_constant (TREE_OPERAND (exp, 0)));
2831 else
2832 return copy_node (exp);
2833
2834 case INTEGER_CST:
2835 case REAL_CST:
2836 case STRING_CST:
2837 return copy_node (exp);
2838
2839 case COMPLEX_CST:
2840 return build_complex (TREE_TYPE (exp),
2841 copy_constant (TREE_REALPART (exp)),
2842 copy_constant (TREE_IMAGPART (exp)));
2843
2844 case PLUS_EXPR:
2845 case MINUS_EXPR:
2846 return build (TREE_CODE (exp), TREE_TYPE (exp),
2847 copy_constant (TREE_OPERAND (exp, 0)),
2848 copy_constant (TREE_OPERAND (exp, 1)));
2849
2850 case NOP_EXPR:
2851 case CONVERT_EXPR:
2852 case NON_LVALUE_EXPR:
2853 return build1 (TREE_CODE (exp), TREE_TYPE (exp),
2854 copy_constant (TREE_OPERAND (exp, 0)));
2855
2856 case CONSTRUCTOR:
2857 {
2858 tree copy = copy_node (exp);
2859 tree list = copy_list (CONSTRUCTOR_ELTS (exp));
2860 tree tail;
2861
2862 CONSTRUCTOR_ELTS (copy) = list;
2863 for (tail = list; tail; tail = TREE_CHAIN (tail))
2864 TREE_VALUE (tail) = copy_constant (TREE_VALUE (tail));
2865 if (TREE_CODE (TREE_TYPE (exp)) == SET_TYPE)
2866 for (tail = list; tail; tail = TREE_CHAIN (tail))
2867 TREE_PURPOSE (tail) = copy_constant (TREE_PURPOSE (tail));
2868
2869 return copy;
2870 }
2871
2872 default:
2873 abort ();
2874 }
2875 }
2876 \f
2877 /* Return an rtx representing a reference to constant data in memory
2878 for the constant expression EXP.
2879
2880 If assembler code for such a constant has already been output,
2881 return an rtx to refer to it.
2882 Otherwise, output such a constant in memory (or defer it for later)
2883 and generate an rtx for it.
2884
2885 The TREE_CST_RTL of EXP is set up to point to that rtx.
2886 The const_hash_table records which constants already have label strings. */
2887
2888 rtx
2889 output_constant_def (exp)
2890 tree exp;
2891 {
2892 register int hash;
2893 register struct constant_descriptor *desc;
2894 char label[256];
2895 char *found = 0;
2896 int reloc;
2897 register rtx def;
2898
2899 if (TREE_CST_RTL (exp))
2900 return TREE_CST_RTL (exp);
2901
2902 /* Make sure any other constants whose addresses appear in EXP
2903 are assigned label numbers. */
2904
2905 reloc = output_addressed_constants (exp);
2906
2907 /* Compute hash code of EXP. Search the descriptors for that hash code
2908 to see if any of them describes EXP. If yes, the descriptor records
2909 the label number already assigned. */
2910
2911 hash = const_hash (exp) % MAX_HASH_TABLE;
2912
2913 for (desc = const_hash_table[hash]; desc; desc = desc->next)
2914 if (compare_constant (exp, desc))
2915 {
2916 found = desc->label;
2917 break;
2918 }
2919
2920 if (found == 0)
2921 {
2922 /* No constant equal to EXP is known to have been output.
2923 Make a constant descriptor to enter EXP in the hash table.
2924 Assign the label number and record it in the descriptor for
2925 future calls to this function to find. */
2926
2927 /* Create a string containing the label name, in LABEL. */
2928 ASM_GENERATE_INTERNAL_LABEL (label, "LC", const_labelno);
2929
2930 desc = record_constant (exp);
2931 desc->next = const_hash_table[hash];
2932 desc->label
2933 = (char *) obstack_copy0 (&permanent_obstack, label, strlen (label));
2934 const_hash_table[hash] = desc;
2935 }
2936 else
2937 {
2938 /* Create a string containing the label name, in LABEL. */
2939 ASM_GENERATE_INTERNAL_LABEL (label, "LC", const_labelno);
2940 }
2941
2942 /* We have a symbol name; construct the SYMBOL_REF and the MEM. */
2943
2944 push_obstacks_nochange ();
2945 if (TREE_PERMANENT (exp))
2946 end_temporary_allocation ();
2947
2948 def = gen_rtx_SYMBOL_REF (Pmode, desc->label);
2949
2950 TREE_CST_RTL (exp)
2951 = gen_rtx_MEM (TYPE_MODE (TREE_TYPE (exp)), def);
2952 RTX_UNCHANGING_P (TREE_CST_RTL (exp)) = 1;
2953 if (AGGREGATE_TYPE_P (TREE_TYPE (exp)))
2954 MEM_IN_STRUCT_P (TREE_CST_RTL (exp)) = 1;
2955
2956 pop_obstacks ();
2957
2958 /* Optionally set flags or add text to the name to record information
2959 such as that it is a function name. If the name is changed, the macro
2960 ASM_OUTPUT_LABELREF will have to know how to strip this information. */
2961 #ifdef ENCODE_SECTION_INFO
2962 ENCODE_SECTION_INFO (exp);
2963 #endif
2964
2965 /* If this is the first time we've seen this particular constant,
2966 output it (or defer its output for later). */
2967 if (found == 0)
2968 {
2969 int after_function = 0;
2970
2971 #ifdef CONSTANT_AFTER_FUNCTION_P
2972 if (current_function_decl != 0
2973 && CONSTANT_AFTER_FUNCTION_P (exp))
2974 after_function = 1;
2975 #endif
2976
2977 if (defer_addressed_constants_flag || after_function)
2978 {
2979 struct deferred_constant *p;
2980 p = (struct deferred_constant *) xmalloc (sizeof (struct deferred_constant));
2981
2982 push_obstacks_nochange ();
2983 suspend_momentary ();
2984 p->exp = copy_constant (exp);
2985 pop_obstacks ();
2986 p->reloc = reloc;
2987 p->labelno = const_labelno++;
2988 if (after_function)
2989 {
2990 p->next = after_function_constants;
2991 after_function_constants = p;
2992 }
2993 else
2994 {
2995 p->next = deferred_constants;
2996 deferred_constants = p;
2997 }
2998 }
2999 else
3000 output_constant_def_contents (exp, reloc, const_labelno++);
3001 }
3002
3003 return TREE_CST_RTL (exp);
3004 }
3005
3006 /* Now output assembler code to define the label for EXP,
3007 and follow it with the data of EXP. */
3008
3009 static void
3010 output_constant_def_contents (exp, reloc, labelno)
3011 tree exp;
3012 int reloc;
3013 int labelno;
3014 {
3015 int align;
3016
3017 if (IN_NAMED_SECTION (exp))
3018 named_section (exp, NULL, reloc);
3019 else
3020 {
3021 /* First switch to text section, except for writable strings. */
3022 #ifdef SELECT_SECTION
3023 SELECT_SECTION (exp, reloc);
3024 #else
3025 if (((TREE_CODE (exp) == STRING_CST) && flag_writable_strings)
3026 || (flag_pic && reloc))
3027 data_section ();
3028 else
3029 readonly_data_section ();
3030 #endif
3031 }
3032
3033 /* Align the location counter as required by EXP's data type. */
3034 align = TYPE_ALIGN (TREE_TYPE (exp));
3035 #ifdef CONSTANT_ALIGNMENT
3036 align = CONSTANT_ALIGNMENT (exp, align);
3037 #endif
3038
3039 if (align > BITS_PER_UNIT)
3040 ASM_OUTPUT_ALIGN (asm_out_file, floor_log2 (align / BITS_PER_UNIT));
3041
3042 /* Output the label itself. */
3043 ASM_OUTPUT_INTERNAL_LABEL (asm_out_file, "LC", labelno);
3044
3045 /* Output the value of EXP. */
3046 output_constant (exp,
3047 (TREE_CODE (exp) == STRING_CST
3048 ? TREE_STRING_LENGTH (exp)
3049 : int_size_in_bytes (TREE_TYPE (exp))));
3050
3051 }
3052 \f
3053 /* Similar hash facility for making memory-constants
3054 from constant rtl-expressions. It is used on RISC machines
3055 where immediate integer arguments and constant addresses are restricted
3056 so that such constants must be stored in memory.
3057
3058 This pool of constants is reinitialized for each function
3059 so each function gets its own constants-pool that comes right before it.
3060
3061 All structures allocated here are discarded when functions are saved for
3062 inlining, so they do not need to be allocated permanently. */
3063
3064 #define MAX_RTX_HASH_TABLE 61
3065 static struct constant_descriptor **const_rtx_hash_table;
3066
3067 /* Structure to represent sufficient information about a constant so that
3068 it can be output when the constant pool is output, so that function
3069 integration can be done, and to simplify handling on machines that reference
3070 constant pool as base+displacement. */
3071
3072 struct pool_constant
3073 {
3074 struct constant_descriptor *desc;
3075 struct pool_constant *next;
3076 enum machine_mode mode;
3077 rtx constant;
3078 int labelno;
3079 int align;
3080 int offset;
3081 int mark;
3082 };
3083
3084 /* Pointers to first and last constant in pool. */
3085
3086 static struct pool_constant *first_pool, *last_pool;
3087
3088 /* Current offset in constant pool (does not include any machine-specific
3089 header. */
3090
3091 static int pool_offset;
3092
3093 /* Structure used to maintain hash table mapping symbols used to their
3094 corresponding constants. */
3095
3096 struct pool_sym
3097 {
3098 char *label;
3099 struct pool_constant *pool;
3100 struct pool_sym *next;
3101 };
3102
3103 static struct pool_sym **const_rtx_sym_hash_table;
3104
3105 /* Hash code for a SYMBOL_REF with CONSTANT_POOL_ADDRESS_P true.
3106 The argument is XSTR (... , 0) */
3107
3108 #define SYMHASH(LABEL) \
3109 ((((unsigned long) (LABEL)) & ((1 << HASHBITS) - 1)) % MAX_RTX_HASH_TABLE)
3110 \f
3111 /* Initialize constant pool hashing for next function. */
3112
3113 void
3114 init_const_rtx_hash_table ()
3115 {
3116 const_rtx_hash_table
3117 = ((struct constant_descriptor **)
3118 oballoc (MAX_RTX_HASH_TABLE * sizeof (struct constant_descriptor *)));
3119 const_rtx_sym_hash_table
3120 = ((struct pool_sym **)
3121 oballoc (MAX_RTX_HASH_TABLE * sizeof (struct pool_sym *)));
3122 bzero ((char *) const_rtx_hash_table,
3123 MAX_RTX_HASH_TABLE * sizeof (struct constant_descriptor *));
3124 bzero ((char *) const_rtx_sym_hash_table,
3125 MAX_RTX_HASH_TABLE * sizeof (struct pool_sym *));
3126
3127 first_pool = last_pool = 0;
3128 pool_offset = 0;
3129 }
3130
3131 /* Save and restore status for a nested function. */
3132
3133 void
3134 save_varasm_status (p, context)
3135 struct function *p;
3136 tree context;
3137 {
3138 p->const_rtx_hash_table = const_rtx_hash_table;
3139 p->const_rtx_sym_hash_table = const_rtx_sym_hash_table;
3140 p->first_pool = first_pool;
3141 p->last_pool = last_pool;
3142 p->pool_offset = pool_offset;
3143 p->const_double_chain = const_double_chain;
3144
3145 /* If we are pushing to toplevel, we can't reuse const_double_chain. */
3146 if (context == NULL_TREE)
3147 const_double_chain = 0;
3148 }
3149
3150 void
3151 restore_varasm_status (p)
3152 struct function *p;
3153 {
3154 const_rtx_hash_table = p->const_rtx_hash_table;
3155 const_rtx_sym_hash_table = p->const_rtx_sym_hash_table;
3156 first_pool = p->first_pool;
3157 last_pool = p->last_pool;
3158 pool_offset = p->pool_offset;
3159 const_double_chain = p->const_double_chain;
3160 }
3161 \f
3162 enum kind { RTX_DOUBLE, RTX_INT };
3163
3164 struct rtx_const
3165 {
3166 #ifdef ONLY_INT_FIELDS
3167 unsigned int kind : 16;
3168 unsigned int mode : 16;
3169 #else
3170 enum kind kind : 16;
3171 enum machine_mode mode : 16;
3172 #endif
3173 union {
3174 union real_extract du;
3175 struct addr_const addr;
3176 struct {HOST_WIDE_INT high, low;} di;
3177 } un;
3178 };
3179
3180 /* Express an rtx for a constant integer (perhaps symbolic)
3181 as the sum of a symbol or label plus an explicit integer.
3182 They are stored into VALUE. */
3183
3184 static void
3185 decode_rtx_const (mode, x, value)
3186 enum machine_mode mode;
3187 rtx x;
3188 struct rtx_const *value;
3189 {
3190 /* Clear the whole structure, including any gaps. */
3191
3192 {
3193 int *p = (int *) value;
3194 int *end = (int *) (value + 1);
3195 while (p < end)
3196 *p++ = 0;
3197 }
3198
3199 value->kind = RTX_INT; /* Most usual kind. */
3200 value->mode = mode;
3201
3202 switch (GET_CODE (x))
3203 {
3204 case CONST_DOUBLE:
3205 value->kind = RTX_DOUBLE;
3206 if (GET_MODE (x) != VOIDmode)
3207 {
3208 value->mode = GET_MODE (x);
3209 bcopy ((char *) &CONST_DOUBLE_LOW (x),
3210 (char *) &value->un.du, sizeof value->un.du);
3211 }
3212 else
3213 {
3214 value->un.di.low = CONST_DOUBLE_LOW (x);
3215 value->un.di.high = CONST_DOUBLE_HIGH (x);
3216 }
3217 break;
3218
3219 case CONST_INT:
3220 value->un.addr.offset = INTVAL (x);
3221 break;
3222
3223 case SYMBOL_REF:
3224 case LABEL_REF:
3225 case PC:
3226 value->un.addr.base = x;
3227 break;
3228
3229 case CONST:
3230 x = XEXP (x, 0);
3231 if (GET_CODE (x) == PLUS)
3232 {
3233 value->un.addr.base = XEXP (x, 0);
3234 if (GET_CODE (XEXP (x, 1)) != CONST_INT)
3235 abort ();
3236 value->un.addr.offset = INTVAL (XEXP (x, 1));
3237 }
3238 else if (GET_CODE (x) == MINUS)
3239 {
3240 value->un.addr.base = XEXP (x, 0);
3241 if (GET_CODE (XEXP (x, 1)) != CONST_INT)
3242 abort ();
3243 value->un.addr.offset = - INTVAL (XEXP (x, 1));
3244 }
3245 else
3246 abort ();
3247 break;
3248
3249 default:
3250 abort ();
3251 }
3252
3253 if (value->kind == RTX_INT && value->un.addr.base != 0)
3254 switch (GET_CODE (value->un.addr.base))
3255 {
3256 case SYMBOL_REF:
3257 case LABEL_REF:
3258 /* Use the string's address, not the SYMBOL_REF's address,
3259 for the sake of addresses of library routines.
3260 For a LABEL_REF, compare labels. */
3261 value->un.addr.base = XEXP (value->un.addr.base, 0);
3262
3263 default:
3264 break;
3265 }
3266 }
3267
3268 /* Given a MINUS expression, simplify it if both sides
3269 include the same symbol. */
3270
3271 rtx
3272 simplify_subtraction (x)
3273 rtx x;
3274 {
3275 struct rtx_const val0, val1;
3276
3277 decode_rtx_const (GET_MODE (x), XEXP (x, 0), &val0);
3278 decode_rtx_const (GET_MODE (x), XEXP (x, 1), &val1);
3279
3280 if (val0.un.addr.base == val1.un.addr.base)
3281 return GEN_INT (val0.un.addr.offset - val1.un.addr.offset);
3282 return x;
3283 }
3284
3285 /* Compute a hash code for a constant RTL expression. */
3286
3287 static int
3288 const_hash_rtx (mode, x)
3289 enum machine_mode mode;
3290 rtx x;
3291 {
3292 register int hi;
3293 register size_t i;
3294
3295 struct rtx_const value;
3296 decode_rtx_const (mode, x, &value);
3297
3298 /* Compute hashing function */
3299 hi = 0;
3300 for (i = 0; i < sizeof value / sizeof (int); i++)
3301 hi += ((int *) &value)[i];
3302
3303 hi &= (1 << HASHBITS) - 1;
3304 hi %= MAX_RTX_HASH_TABLE;
3305 return hi;
3306 }
3307
3308 /* Compare a constant rtl object X with a constant-descriptor DESC.
3309 Return 1 if DESC describes a constant with the same value as X. */
3310
3311 static int
3312 compare_constant_rtx (mode, x, desc)
3313 enum machine_mode mode;
3314 rtx x;
3315 struct constant_descriptor *desc;
3316 {
3317 register int *p = (int *) desc->contents;
3318 register int *strp;
3319 register int len;
3320 struct rtx_const value;
3321
3322 decode_rtx_const (mode, x, &value);
3323 strp = (int *) &value;
3324 len = sizeof value / sizeof (int);
3325
3326 /* Compare constant contents. */
3327 while (--len >= 0)
3328 if (*p++ != *strp++)
3329 return 0;
3330
3331 return 1;
3332 }
3333
3334 /* Construct a constant descriptor for the rtl-expression X.
3335 It is up to the caller to enter the descriptor in the hash table. */
3336
3337 static struct constant_descriptor *
3338 record_constant_rtx (mode, x)
3339 enum machine_mode mode;
3340 rtx x;
3341 {
3342 struct constant_descriptor *ptr;
3343 char *label;
3344 struct rtx_const value;
3345
3346 decode_rtx_const (mode, x, &value);
3347
3348 /* Put these things in the saveable obstack so we can ensure it won't
3349 be freed if we are called from combine or some other phase that discards
3350 memory allocated from function_obstack (current_obstack). */
3351 obstack_grow (saveable_obstack, &ptr, sizeof ptr);
3352 obstack_grow (saveable_obstack, &label, sizeof label);
3353
3354 /* Record constant contents. */
3355 obstack_grow (saveable_obstack, &value, sizeof value);
3356
3357 return (struct constant_descriptor *) obstack_finish (saveable_obstack);
3358 }
3359 \f
3360 /* Given a constant rtx X, make (or find) a memory constant for its value
3361 and return a MEM rtx to refer to it in memory. */
3362
3363 rtx
3364 force_const_mem (mode, x)
3365 enum machine_mode mode;
3366 rtx x;
3367 {
3368 register int hash;
3369 register struct constant_descriptor *desc;
3370 char label[256];
3371 char *found = 0;
3372 rtx def;
3373
3374 /* If we want this CONST_DOUBLE in the same mode as it is in memory
3375 (this will always be true for floating CONST_DOUBLEs that have been
3376 placed in memory, but not for VOIDmode (integer) CONST_DOUBLEs),
3377 use the previous copy. Otherwise, make a new one. Note that in
3378 the unlikely event that this same CONST_DOUBLE is used in two different
3379 modes in an alternating fashion, we will allocate a lot of different
3380 memory locations, but this should be extremely rare. */
3381
3382 /* Don't use CONST_DOUBLE_MEM in a nested function.
3383 Nested functions have their own constant pools,
3384 so they can't share the same values in CONST_DOUBLE_MEM
3385 with the containing function. */
3386 if (outer_function_chain == 0)
3387 if (GET_CODE (x) == CONST_DOUBLE
3388 && GET_CODE (CONST_DOUBLE_MEM (x)) == MEM
3389 && GET_MODE (CONST_DOUBLE_MEM (x)) == mode)
3390 return CONST_DOUBLE_MEM (x);
3391
3392 /* Compute hash code of X. Search the descriptors for that hash code
3393 to see if any of them describes X. If yes, the descriptor records
3394 the label number already assigned. */
3395
3396 hash = const_hash_rtx (mode, x);
3397
3398 for (desc = const_rtx_hash_table[hash]; desc; desc = desc->next)
3399 if (compare_constant_rtx (mode, x, desc))
3400 {
3401 found = desc->label;
3402 break;
3403 }
3404
3405 if (found == 0)
3406 {
3407 register struct pool_constant *pool;
3408 register struct pool_sym *sym;
3409 int align;
3410
3411 /* No constant equal to X is known to have been output.
3412 Make a constant descriptor to enter X in the hash table.
3413 Assign the label number and record it in the descriptor for
3414 future calls to this function to find. */
3415
3416 desc = record_constant_rtx (mode, x);
3417 desc->next = const_rtx_hash_table[hash];
3418 const_rtx_hash_table[hash] = desc;
3419
3420 /* Align the location counter as required by EXP's data type. */
3421 align = (mode == VOIDmode) ? UNITS_PER_WORD : GET_MODE_SIZE (mode);
3422 if (align > BIGGEST_ALIGNMENT / BITS_PER_UNIT)
3423 align = BIGGEST_ALIGNMENT / BITS_PER_UNIT;
3424 #ifdef CONSTANT_ALIGNMENT
3425 align = CONSTANT_ALIGNMENT (make_tree (type_for_mode (mode, 0), x),
3426 align * BITS_PER_UNIT) / BITS_PER_UNIT;
3427 #endif
3428
3429 pool_offset += align - 1;
3430 pool_offset &= ~ (align - 1);
3431
3432 /* If RTL is not being placed into the saveable obstack, make a
3433 copy of X that is in the saveable obstack in case we are
3434 being called from combine or some other phase that discards
3435 memory it allocates. We used to only do this if it is a
3436 CONST; however, reload can allocate a CONST_INT when
3437 eliminating registers. */
3438 if (rtl_obstack != saveable_obstack
3439 && (GET_CODE (x) == CONST || GET_CODE (x) == CONST_INT))
3440 {
3441 push_obstacks_nochange ();
3442 rtl_in_saveable_obstack ();
3443
3444 if (GET_CODE (x) == CONST)
3445 x = gen_rtx_CONST (GET_MODE (x),
3446 gen_rtx_PLUS (GET_MODE (x),
3447 XEXP (XEXP (x, 0), 0),
3448 XEXP (XEXP (x, 0), 1)));
3449 else
3450 x = GEN_INT (INTVAL (x));
3451
3452 pop_obstacks ();
3453 }
3454
3455 /* Allocate a pool constant descriptor, fill it in, and chain it in. */
3456
3457 pool = (struct pool_constant *) savealloc (sizeof (struct pool_constant));
3458 pool->desc = desc;
3459 pool->constant = x;
3460 pool->mode = mode;
3461 pool->labelno = const_labelno;
3462 pool->align = align;
3463 pool->offset = pool_offset;
3464 pool->mark = 1;
3465 pool->next = 0;
3466
3467 if (last_pool == 0)
3468 first_pool = pool;
3469 else
3470 last_pool->next = pool;
3471
3472 last_pool = pool;
3473 pool_offset += GET_MODE_SIZE (mode);
3474
3475 /* Create a string containing the label name, in LABEL. */
3476 ASM_GENERATE_INTERNAL_LABEL (label, "LC", const_labelno);
3477
3478 ++const_labelno;
3479
3480 desc->label = found
3481 = (char *) obstack_copy0 (saveable_obstack, label, strlen (label));
3482
3483 /* Add label to symbol hash table. */
3484 hash = SYMHASH (found);
3485 sym = (struct pool_sym *) savealloc (sizeof (struct pool_sym));
3486 sym->label = found;
3487 sym->pool = pool;
3488 sym->next = const_rtx_sym_hash_table[hash];
3489 const_rtx_sym_hash_table[hash] = sym;
3490 }
3491
3492 /* We have a symbol name; construct the SYMBOL_REF and the MEM. */
3493
3494 def = gen_rtx_MEM (mode, gen_rtx_SYMBOL_REF (Pmode, found));
3495
3496 RTX_UNCHANGING_P (def) = 1;
3497 /* Mark the symbol_ref as belonging to this constants pool. */
3498 CONSTANT_POOL_ADDRESS_P (XEXP (def, 0)) = 1;
3499 current_function_uses_const_pool = 1;
3500
3501 if (outer_function_chain == 0)
3502 if (GET_CODE (x) == CONST_DOUBLE)
3503 {
3504 if (CONST_DOUBLE_MEM (x) == cc0_rtx)
3505 {
3506 CONST_DOUBLE_CHAIN (x) = const_double_chain;
3507 const_double_chain = x;
3508 }
3509 CONST_DOUBLE_MEM (x) = def;
3510 }
3511
3512 return def;
3513 }
3514 \f
3515 /* Given a SYMBOL_REF with CONSTANT_POOL_ADDRESS_P true, return a pointer to
3516 the corresponding pool_constant structure. */
3517
3518 static struct pool_constant *
3519 find_pool_constant (addr)
3520 rtx addr;
3521 {
3522 struct pool_sym *sym;
3523 char *label = XSTR (addr, 0);
3524
3525 for (sym = const_rtx_sym_hash_table[SYMHASH (label)]; sym; sym = sym->next)
3526 if (sym->label == label)
3527 return sym->pool;
3528
3529 abort ();
3530 }
3531
3532 /* Given a constant pool SYMBOL_REF, return the corresponding constant. */
3533
3534 rtx
3535 get_pool_constant (addr)
3536 rtx addr;
3537 {
3538 return (find_pool_constant (addr))->constant;
3539 }
3540
3541 /* Similar, return the mode. */
3542
3543 enum machine_mode
3544 get_pool_mode (addr)
3545 rtx addr;
3546 {
3547 return (find_pool_constant (addr))->mode;
3548 }
3549
3550 /* Similar, return the offset in the constant pool. */
3551
3552 int
3553 get_pool_offset (addr)
3554 rtx addr;
3555 {
3556 return (find_pool_constant (addr))->offset;
3557 }
3558
3559 /* Return the size of the constant pool. */
3560
3561 int
3562 get_pool_size ()
3563 {
3564 return pool_offset;
3565 }
3566 \f
3567 /* Write all the constants in the constant pool. */
3568
3569 void
3570 output_constant_pool (fnname, fndecl)
3571 char *fnname;
3572 tree fndecl;
3573 {
3574 struct pool_constant *pool;
3575 rtx x;
3576 union real_extract u;
3577
3578 /* It is possible for gcc to call force_const_mem and then to later
3579 discard the instructions which refer to the constant. In such a
3580 case we do not need to output the constant. */
3581 if (optimize >= 0 && flag_expensive_optimizations)
3582 mark_constant_pool ();
3583
3584 #ifdef ASM_OUTPUT_POOL_PROLOGUE
3585 ASM_OUTPUT_POOL_PROLOGUE (asm_out_file, fnname, fndecl, pool_offset);
3586 #endif
3587
3588 for (pool = first_pool; pool; pool = pool->next)
3589 {
3590 x = pool->constant;
3591
3592 if (! pool->mark)
3593 continue;
3594
3595 /* See if X is a LABEL_REF (or a CONST referring to a LABEL_REF)
3596 whose CODE_LABEL has been deleted. This can occur if a jump table
3597 is eliminated by optimization. If so, write a constant of zero
3598 instead. Note that this can also happen by turning the
3599 CODE_LABEL into a NOTE. */
3600 if (((GET_CODE (x) == LABEL_REF
3601 && (INSN_DELETED_P (XEXP (x, 0))
3602 || GET_CODE (XEXP (x, 0)) == NOTE)))
3603 || (GET_CODE (x) == CONST && GET_CODE (XEXP (x, 0)) == PLUS
3604 && GET_CODE (XEXP (XEXP (x, 0), 0)) == LABEL_REF
3605 && (INSN_DELETED_P (XEXP (XEXP (XEXP (x, 0), 0), 0))
3606 || GET_CODE (XEXP (XEXP (XEXP (x, 0), 0), 0)) == NOTE)))
3607 x = const0_rtx;
3608
3609 /* First switch to correct section. */
3610 #ifdef SELECT_RTX_SECTION
3611 SELECT_RTX_SECTION (pool->mode, x);
3612 #else
3613 readonly_data_section ();
3614 #endif
3615
3616 #ifdef ASM_OUTPUT_SPECIAL_POOL_ENTRY
3617 ASM_OUTPUT_SPECIAL_POOL_ENTRY (asm_out_file, x, pool->mode,
3618 pool->align, pool->labelno, done);
3619 #endif
3620
3621 if (pool->align > 1)
3622 ASM_OUTPUT_ALIGN (asm_out_file, exact_log2 (pool->align));
3623
3624 /* Output the label. */
3625 ASM_OUTPUT_INTERNAL_LABEL (asm_out_file, "LC", pool->labelno);
3626
3627 /* Output the value of the constant itself. */
3628 switch (GET_MODE_CLASS (pool->mode))
3629 {
3630 case MODE_FLOAT:
3631 if (GET_CODE (x) != CONST_DOUBLE)
3632 abort ();
3633
3634 bcopy ((char *) &CONST_DOUBLE_LOW (x), (char *) &u, sizeof u);
3635 assemble_real (u.d, pool->mode);
3636 break;
3637
3638 case MODE_INT:
3639 case MODE_PARTIAL_INT:
3640 assemble_integer (x, GET_MODE_SIZE (pool->mode), 1);
3641 break;
3642
3643 default:
3644 abort ();
3645 }
3646
3647 #ifdef ASM_OUTPUT_SPECIAL_POOL_ENTRY
3648 done: ;
3649 #endif
3650
3651 }
3652
3653 #ifdef ASM_OUTPUT_POOL_EPILOGUE
3654 ASM_OUTPUT_POOL_EPILOGUE (asm_out_file, fnname, fndecl, pool_offset);
3655 #endif
3656
3657 /* Done with this pool. */
3658 first_pool = last_pool = 0;
3659 }
3660
3661 /* Look through the instructions for this function, and mark all the
3662 entries in the constant pool which are actually being used. */
3663
3664 static void
3665 mark_constant_pool ()
3666 {
3667 register rtx insn;
3668 struct pool_constant *pool;
3669
3670 if (first_pool == 0)
3671 return;
3672
3673 for (pool = first_pool; pool; pool = pool->next)
3674 pool->mark = 0;
3675
3676 for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
3677 if (GET_RTX_CLASS (GET_CODE (insn)) == 'i')
3678 mark_constants (PATTERN (insn));
3679
3680 for (insn = current_function_epilogue_delay_list;
3681 insn;
3682 insn = XEXP (insn, 1))
3683 if (GET_RTX_CLASS (GET_CODE (insn)) == 'i')
3684 mark_constants (PATTERN (insn));
3685 }
3686
3687 static void
3688 mark_constants (x)
3689 register rtx x;
3690 {
3691 register int i;
3692 register char *format_ptr;
3693
3694 if (x == 0)
3695 return;
3696
3697 if (GET_CODE (x) == SYMBOL_REF)
3698 {
3699 if (CONSTANT_POOL_ADDRESS_P (x))
3700 find_pool_constant (x)->mark = 1;
3701 return;
3702 }
3703 /* Never search inside a CONST_DOUBLE, because CONST_DOUBLE_MEM may be
3704 a MEM, but does not constitute a use of that MEM. This is particularly
3705 important inside a nested function, because CONST_DOUBLE_MEM may be
3706 a reference to a MEM in the parent's constant pool. See the comment
3707 in force_const_mem. */
3708 else if (GET_CODE (x) == CONST_DOUBLE)
3709 return;
3710
3711 /* Insns may appear inside a SEQUENCE. Only check the patterns of
3712 insns, not any notes that may be attached. We don't want to mark
3713 a constant just because it happens to appear in a REG_EQUIV note. */
3714 if (GET_RTX_CLASS (GET_CODE (x)) == 'i')
3715 {
3716 mark_constants (PATTERN (x));
3717 return;
3718 }
3719
3720 format_ptr = GET_RTX_FORMAT (GET_CODE (x));
3721
3722 for (i = 0; i < GET_RTX_LENGTH (GET_CODE (x)); i++)
3723 {
3724 switch (*format_ptr++)
3725 {
3726 case 'e':
3727 mark_constants (XEXP (x, i));
3728 break;
3729
3730 case 'E':
3731 if (XVEC (x, i) != 0)
3732 {
3733 register int j;
3734
3735 for (j = 0; j < XVECLEN (x, i); j++)
3736 mark_constants (XVECEXP (x, i, j));
3737 }
3738 break;
3739
3740 case 'S':
3741 case 's':
3742 case '0':
3743 case 'i':
3744 case 'w':
3745 case 'n':
3746 case 'u':
3747 break;
3748
3749 default:
3750 abort ();
3751 }
3752 }
3753 }
3754 \f
3755 /* Find all the constants whose addresses are referenced inside of EXP,
3756 and make sure assembler code with a label has been output for each one.
3757 Indicate whether an ADDR_EXPR has been encountered. */
3758
3759 static int
3760 output_addressed_constants (exp)
3761 tree exp;
3762 {
3763 int reloc = 0;
3764
3765 switch (TREE_CODE (exp))
3766 {
3767 case ADDR_EXPR:
3768 {
3769 register tree constant = TREE_OPERAND (exp, 0);
3770
3771 while (TREE_CODE (constant) == COMPONENT_REF)
3772 {
3773 constant = TREE_OPERAND (constant, 0);
3774 }
3775
3776 if (TREE_CODE_CLASS (TREE_CODE (constant)) == 'c'
3777 || TREE_CODE (constant) == CONSTRUCTOR)
3778 /* No need to do anything here
3779 for addresses of variables or functions. */
3780 output_constant_def (constant);
3781 }
3782 reloc = 1;
3783 break;
3784
3785 case PLUS_EXPR:
3786 case MINUS_EXPR:
3787 reloc = output_addressed_constants (TREE_OPERAND (exp, 0));
3788 reloc |= output_addressed_constants (TREE_OPERAND (exp, 1));
3789 break;
3790
3791 case NOP_EXPR:
3792 case CONVERT_EXPR:
3793 case NON_LVALUE_EXPR:
3794 reloc = output_addressed_constants (TREE_OPERAND (exp, 0));
3795 break;
3796
3797 case CONSTRUCTOR:
3798 {
3799 register tree link;
3800 for (link = CONSTRUCTOR_ELTS (exp); link; link = TREE_CHAIN (link))
3801 if (TREE_VALUE (link) != 0)
3802 reloc |= output_addressed_constants (TREE_VALUE (link));
3803 }
3804 break;
3805
3806 default:
3807 break;
3808 }
3809 return reloc;
3810 }
3811 \f
3812 /* Output assembler code for constant EXP to FILE, with no label.
3813 This includes the pseudo-op such as ".int" or ".byte", and a newline.
3814 Assumes output_addressed_constants has been done on EXP already.
3815
3816 Generate exactly SIZE bytes of assembler data, padding at the end
3817 with zeros if necessary. SIZE must always be specified.
3818
3819 SIZE is important for structure constructors,
3820 since trailing members may have been omitted from the constructor.
3821 It is also important for initialization of arrays from string constants
3822 since the full length of the string constant might not be wanted.
3823 It is also needed for initialization of unions, where the initializer's
3824 type is just one member, and that may not be as long as the union.
3825
3826 There a case in which we would fail to output exactly SIZE bytes:
3827 for a structure constructor that wants to produce more than SIZE bytes.
3828 But such constructors will never be generated for any possible input. */
3829
3830 void
3831 output_constant (exp, size)
3832 register tree exp;
3833 register int size;
3834 {
3835 register enum tree_code code = TREE_CODE (TREE_TYPE (exp));
3836
3837 if (size == 0)
3838 return;
3839
3840 /* Eliminate the NON_LVALUE_EXPR_EXPR that makes a cast not be an lvalue.
3841 That way we get the constant (we hope) inside it. Also, strip off any
3842 NOP_EXPR that converts between two record, union, array, or set types. */
3843 while ((TREE_CODE (exp) == NOP_EXPR
3844 && (TREE_TYPE (exp) == TREE_TYPE (TREE_OPERAND (exp, 0))
3845 || AGGREGATE_TYPE_P (TREE_TYPE (exp))))
3846 || TREE_CODE (exp) == NON_LVALUE_EXPR)
3847 exp = TREE_OPERAND (exp, 0);
3848
3849 /* Allow a constructor with no elements for any data type.
3850 This means to fill the space with zeros. */
3851 if (TREE_CODE (exp) == CONSTRUCTOR && CONSTRUCTOR_ELTS (exp) == 0)
3852 {
3853 assemble_zeros (size);
3854 return;
3855 }
3856
3857 switch (code)
3858 {
3859 case CHAR_TYPE:
3860 case BOOLEAN_TYPE:
3861 case INTEGER_TYPE:
3862 case ENUMERAL_TYPE:
3863 case POINTER_TYPE:
3864 case REFERENCE_TYPE:
3865 /* ??? What about (int)((float)(int)&foo + 4) */
3866 while (TREE_CODE (exp) == NOP_EXPR || TREE_CODE (exp) == CONVERT_EXPR
3867 || TREE_CODE (exp) == NON_LVALUE_EXPR)
3868 exp = TREE_OPERAND (exp, 0);
3869
3870 if (! assemble_integer (expand_expr (exp, NULL_RTX, VOIDmode,
3871 EXPAND_INITIALIZER),
3872 size, 0))
3873 error ("initializer for integer value is too complicated");
3874 size = 0;
3875 break;
3876
3877 case REAL_TYPE:
3878 if (TREE_CODE (exp) != REAL_CST)
3879 error ("initializer for floating value is not a floating constant");
3880
3881 assemble_real (TREE_REAL_CST (exp),
3882 mode_for_size (size * BITS_PER_UNIT, MODE_FLOAT, 0));
3883 size = 0;
3884 break;
3885
3886 case COMPLEX_TYPE:
3887 output_constant (TREE_REALPART (exp), size / 2);
3888 output_constant (TREE_IMAGPART (exp), size / 2);
3889 size -= (size / 2) * 2;
3890 break;
3891
3892 case ARRAY_TYPE:
3893 if (TREE_CODE (exp) == CONSTRUCTOR)
3894 {
3895 output_constructor (exp, size);
3896 return;
3897 }
3898 else if (TREE_CODE (exp) == STRING_CST)
3899 {
3900 int excess = 0;
3901
3902 if (size > TREE_STRING_LENGTH (exp))
3903 {
3904 excess = size - TREE_STRING_LENGTH (exp);
3905 size = TREE_STRING_LENGTH (exp);
3906 }
3907
3908 assemble_string (TREE_STRING_POINTER (exp), size);
3909 size = excess;
3910 }
3911 else
3912 abort ();
3913 break;
3914
3915 case RECORD_TYPE:
3916 case UNION_TYPE:
3917 if (TREE_CODE (exp) == CONSTRUCTOR)
3918 output_constructor (exp, size);
3919 else
3920 abort ();
3921 return;
3922
3923 case SET_TYPE:
3924 if (TREE_CODE (exp) == INTEGER_CST)
3925 assemble_integer (expand_expr (exp, NULL_RTX,
3926 VOIDmode, EXPAND_INITIALIZER),
3927 size, 1);
3928 else if (TREE_CODE (exp) == CONSTRUCTOR)
3929 {
3930 unsigned char *buffer = (unsigned char *) alloca (size);
3931 if (get_set_constructor_bytes (exp, buffer, size))
3932 abort ();
3933 assemble_string ((char *) buffer, size);
3934 }
3935 else
3936 error ("unknown set constructor type");
3937 return;
3938
3939 default:
3940 break; /* ??? */
3941 }
3942
3943 if (size > 0)
3944 assemble_zeros (size);
3945 }
3946
3947 \f
3948 /* Subroutine of output_constant, used for CONSTRUCTORs
3949 (aggregate constants).
3950 Generate at least SIZE bytes, padding if necessary. */
3951
3952 static void
3953 output_constructor (exp, size)
3954 tree exp;
3955 int size;
3956 {
3957 register tree link, field = 0;
3958 HOST_WIDE_INT min_index = 0;
3959 /* Number of bytes output or skipped so far.
3960 In other words, current position within the constructor. */
3961 int total_bytes = 0;
3962 /* Non-zero means BYTE contains part of a byte, to be output. */
3963 int byte_buffer_in_use = 0;
3964 register int byte;
3965
3966 if (HOST_BITS_PER_WIDE_INT < BITS_PER_UNIT)
3967 abort ();
3968
3969 if (TREE_CODE (TREE_TYPE (exp)) == RECORD_TYPE)
3970 field = TYPE_FIELDS (TREE_TYPE (exp));
3971
3972 if (TREE_CODE (TREE_TYPE (exp)) == ARRAY_TYPE
3973 && TYPE_DOMAIN (TREE_TYPE (exp)) != 0)
3974 min_index
3975 = TREE_INT_CST_LOW (TYPE_MIN_VALUE (TYPE_DOMAIN (TREE_TYPE (exp))));
3976
3977 /* As LINK goes through the elements of the constant,
3978 FIELD goes through the structure fields, if the constant is a structure.
3979 if the constant is a union, then we override this,
3980 by getting the field from the TREE_LIST element.
3981 But the constant could also be an array. Then FIELD is zero. */
3982 for (link = CONSTRUCTOR_ELTS (exp);
3983 link;
3984 link = TREE_CHAIN (link),
3985 field = field ? TREE_CHAIN (field) : 0)
3986 {
3987 tree val = TREE_VALUE (link);
3988 tree index = 0;
3989
3990 /* the element in a union constructor specifies the proper field. */
3991
3992 if (TREE_CODE (TREE_TYPE (exp)) == RECORD_TYPE
3993 || TREE_CODE (TREE_TYPE (exp)) == UNION_TYPE)
3994 {
3995 /* if available, use the type given by link */
3996 if (TREE_PURPOSE (link) != 0)
3997 field = TREE_PURPOSE (link);
3998 }
3999
4000 if (TREE_CODE (TREE_TYPE (exp)) == ARRAY_TYPE)
4001 index = TREE_PURPOSE (link);
4002
4003 /* Eliminate the marker that makes a cast not be an lvalue. */
4004 if (val != 0)
4005 STRIP_NOPS (val);
4006
4007 if (index && TREE_CODE (index) == RANGE_EXPR)
4008 {
4009 register int fieldsize
4010 = int_size_in_bytes (TREE_TYPE (TREE_TYPE (exp)));
4011 HOST_WIDE_INT lo_index = TREE_INT_CST_LOW (TREE_OPERAND (index, 0));
4012 HOST_WIDE_INT hi_index = TREE_INT_CST_LOW (TREE_OPERAND (index, 1));
4013 HOST_WIDE_INT index;
4014 for (index = lo_index; index <= hi_index; index++)
4015 {
4016 /* Output the element's initial value. */
4017 if (val == 0)
4018 assemble_zeros (fieldsize);
4019 else
4020 output_constant (val, fieldsize);
4021
4022 /* Count its size. */
4023 total_bytes += fieldsize;
4024 }
4025 }
4026 else if (field == 0 || !DECL_BIT_FIELD (field))
4027 {
4028 /* An element that is not a bit-field. */
4029
4030 register int fieldsize;
4031 /* Since this structure is static,
4032 we know the positions are constant. */
4033 int bitpos = (field ? (TREE_INT_CST_LOW (DECL_FIELD_BITPOS (field))
4034 / BITS_PER_UNIT)
4035 : 0);
4036 if (index != 0)
4037 bitpos = (TREE_INT_CST_LOW (TYPE_SIZE (TREE_TYPE (val)))
4038 / BITS_PER_UNIT
4039 * (TREE_INT_CST_LOW (index) - min_index));
4040
4041 /* Output any buffered-up bit-fields preceding this element. */
4042 if (byte_buffer_in_use)
4043 {
4044 ASM_OUTPUT_BYTE (asm_out_file, byte);
4045 total_bytes++;
4046 byte_buffer_in_use = 0;
4047 }
4048
4049 /* Advance to offset of this element.
4050 Note no alignment needed in an array, since that is guaranteed
4051 if each element has the proper size. */
4052 if ((field != 0 || index != 0) && bitpos != total_bytes)
4053 {
4054 assemble_zeros (bitpos - total_bytes);
4055 total_bytes = bitpos;
4056 }
4057
4058 /* Determine size this element should occupy. */
4059 if (field)
4060 {
4061 if (TREE_CODE (DECL_SIZE (field)) != INTEGER_CST)
4062 abort ();
4063 if (TREE_INT_CST_LOW (DECL_SIZE (field)) > 100000)
4064 {
4065 /* This avoids overflow trouble. */
4066 tree size_tree = size_binop (CEIL_DIV_EXPR,
4067 DECL_SIZE (field),
4068 size_int (BITS_PER_UNIT));
4069 fieldsize = TREE_INT_CST_LOW (size_tree);
4070 }
4071 else
4072 {
4073 fieldsize = TREE_INT_CST_LOW (DECL_SIZE (field));
4074 fieldsize = (fieldsize + BITS_PER_UNIT - 1) / BITS_PER_UNIT;
4075 }
4076 }
4077 else
4078 fieldsize = int_size_in_bytes (TREE_TYPE (TREE_TYPE (exp)));
4079
4080 /* Output the element's initial value. */
4081 if (val == 0)
4082 assemble_zeros (fieldsize);
4083 else
4084 output_constant (val, fieldsize);
4085
4086 /* Count its size. */
4087 total_bytes += fieldsize;
4088 }
4089 else if (val != 0 && TREE_CODE (val) != INTEGER_CST)
4090 error ("invalid initial value for member `%s'",
4091 IDENTIFIER_POINTER (DECL_NAME (field)));
4092 else
4093 {
4094 /* Element that is a bit-field. */
4095
4096 int next_offset = TREE_INT_CST_LOW (DECL_FIELD_BITPOS (field));
4097 int end_offset
4098 = (next_offset + TREE_INT_CST_LOW (DECL_SIZE (field)));
4099
4100 if (val == 0)
4101 val = integer_zero_node;
4102
4103 /* If this field does not start in this (or, next) byte,
4104 skip some bytes. */
4105 if (next_offset / BITS_PER_UNIT != total_bytes)
4106 {
4107 /* Output remnant of any bit field in previous bytes. */
4108 if (byte_buffer_in_use)
4109 {
4110 ASM_OUTPUT_BYTE (asm_out_file, byte);
4111 total_bytes++;
4112 byte_buffer_in_use = 0;
4113 }
4114
4115 /* If still not at proper byte, advance to there. */
4116 if (next_offset / BITS_PER_UNIT != total_bytes)
4117 {
4118 assemble_zeros (next_offset / BITS_PER_UNIT - total_bytes);
4119 total_bytes = next_offset / BITS_PER_UNIT;
4120 }
4121 }
4122
4123 if (! byte_buffer_in_use)
4124 byte = 0;
4125
4126 /* We must split the element into pieces that fall within
4127 separate bytes, and combine each byte with previous or
4128 following bit-fields. */
4129
4130 /* next_offset is the offset n fbits from the beginning of
4131 the structure to the next bit of this element to be processed.
4132 end_offset is the offset of the first bit past the end of
4133 this element. */
4134 while (next_offset < end_offset)
4135 {
4136 int this_time;
4137 int shift;
4138 HOST_WIDE_INT value;
4139 int next_byte = next_offset / BITS_PER_UNIT;
4140 int next_bit = next_offset % BITS_PER_UNIT;
4141
4142 /* Advance from byte to byte
4143 within this element when necessary. */
4144 while (next_byte != total_bytes)
4145 {
4146 ASM_OUTPUT_BYTE (asm_out_file, byte);
4147 total_bytes++;
4148 byte = 0;
4149 }
4150
4151 /* Number of bits we can process at once
4152 (all part of the same byte). */
4153 this_time = MIN (end_offset - next_offset,
4154 BITS_PER_UNIT - next_bit);
4155 if (BYTES_BIG_ENDIAN)
4156 {
4157 /* On big-endian machine, take the most significant bits
4158 first (of the bits that are significant)
4159 and put them into bytes from the most significant end. */
4160 shift = end_offset - next_offset - this_time;
4161 /* Don't try to take a bunch of bits that cross
4162 the word boundary in the INTEGER_CST. */
4163 if (shift < HOST_BITS_PER_WIDE_INT
4164 && shift + this_time > HOST_BITS_PER_WIDE_INT)
4165 {
4166 this_time -= (HOST_BITS_PER_WIDE_INT - shift);
4167 shift = HOST_BITS_PER_WIDE_INT;
4168 }
4169
4170 /* Now get the bits from the appropriate constant word. */
4171 if (shift < HOST_BITS_PER_WIDE_INT)
4172 {
4173 value = TREE_INT_CST_LOW (val);
4174 }
4175 else if (shift < 2 * HOST_BITS_PER_WIDE_INT)
4176 {
4177 value = TREE_INT_CST_HIGH (val);
4178 shift -= HOST_BITS_PER_WIDE_INT;
4179 }
4180 else
4181 abort ();
4182 byte |= (((value >> shift)
4183 & (((HOST_WIDE_INT) 1 << this_time) - 1))
4184 << (BITS_PER_UNIT - this_time - next_bit));
4185 }
4186 else
4187 {
4188 /* On little-endian machines,
4189 take first the least significant bits of the value
4190 and pack them starting at the least significant
4191 bits of the bytes. */
4192 shift = (next_offset
4193 - TREE_INT_CST_LOW (DECL_FIELD_BITPOS (field)));
4194 /* Don't try to take a bunch of bits that cross
4195 the word boundary in the INTEGER_CST. */
4196 if (shift < HOST_BITS_PER_WIDE_INT
4197 && shift + this_time > HOST_BITS_PER_WIDE_INT)
4198 {
4199 this_time -= (HOST_BITS_PER_WIDE_INT - shift);
4200 shift = HOST_BITS_PER_WIDE_INT;
4201 }
4202
4203 /* Now get the bits from the appropriate constant word. */
4204 if (shift < HOST_BITS_PER_WIDE_INT)
4205 value = TREE_INT_CST_LOW (val);
4206 else if (shift < 2 * HOST_BITS_PER_WIDE_INT)
4207 {
4208 value = TREE_INT_CST_HIGH (val);
4209 shift -= HOST_BITS_PER_WIDE_INT;
4210 }
4211 else
4212 abort ();
4213 byte |= (((value >> shift)
4214 & (((HOST_WIDE_INT) 1 << this_time) - 1))
4215 << next_bit);
4216 }
4217 next_offset += this_time;
4218 byte_buffer_in_use = 1;
4219 }
4220 }
4221 }
4222 if (byte_buffer_in_use)
4223 {
4224 ASM_OUTPUT_BYTE (asm_out_file, byte);
4225 total_bytes++;
4226 }
4227 if (total_bytes < size)
4228 assemble_zeros (size - total_bytes);
4229 }
4230
4231 /* Output asm to handle ``#pragma weak'' */
4232
4233 void
4234 handle_pragma_weak (what, name, value)
4235 enum pragma_state what;
4236 char *name, *value;
4237 {
4238 #ifdef HANDLE_PRAGMA_WEAK
4239 if (what == ps_name || what == ps_value)
4240 {
4241 struct weak_syms *weak =
4242 (struct weak_syms *)permalloc (sizeof (struct weak_syms));
4243 weak->next = weak_decls;
4244 weak->name = permalloc (strlen (name) + 1);
4245 strcpy (weak->name, name);
4246
4247 if (what != ps_value)
4248 weak->value = NULL_PTR;
4249
4250 else
4251 {
4252 weak->value = permalloc (strlen (value) + 1);
4253 strcpy (weak->value, value);
4254 }
4255
4256 weak_decls = weak;
4257 }
4258 else if (! (what == ps_done || what == ps_start))
4259 warning ("malformed `#pragma weak'");
4260 #endif /* HANDLE_PRAGMA_WEAK */
4261 }
4262
4263 /* Declare DECL to be a weak symbol. */
4264
4265 void
4266 declare_weak (decl)
4267 tree decl;
4268 {
4269 if (! TREE_PUBLIC (decl))
4270 error_with_decl (decl, "weak declaration of `%s' must be public");
4271 else if (TREE_ASM_WRITTEN (decl))
4272 error_with_decl (decl, "weak declaration of `%s' must precede definition");
4273 else if (SUPPORTS_WEAK)
4274 DECL_WEAK (decl) = 1;
4275 }
4276
4277 /* Emit any pending weak declarations. */
4278
4279 void
4280 weak_finish ()
4281 {
4282 #ifdef HANDLE_PRAGMA_WEAK
4283 if (HANDLE_PRAGMA_WEAK)
4284 {
4285 struct weak_syms *t;
4286 for (t = weak_decls; t; t = t->next)
4287 {
4288 ASM_WEAKEN_LABEL (asm_out_file, t->name);
4289 if (t->value)
4290 ASM_OUTPUT_DEF (asm_out_file, t->name, t->value);
4291 }
4292 }
4293 #endif
4294 }
4295
4296 void
4297 assemble_alias (decl, target)
4298 tree decl, target;
4299 {
4300 char *name;
4301
4302 make_decl_rtl (decl, (char *) 0, 1);
4303 name = XSTR (XEXP (DECL_RTL (decl), 0), 0);
4304
4305 #ifdef ASM_OUTPUT_DEF
4306 /* Make name accessible from other files, if appropriate. */
4307
4308 if (TREE_PUBLIC (decl))
4309 {
4310 #ifdef ASM_WEAKEN_LABEL
4311 if (DECL_WEAK (decl))
4312 ASM_WEAKEN_LABEL (asm_out_file, name);
4313 else
4314 #endif
4315 ASM_GLOBALIZE_LABEL (asm_out_file, name);
4316 }
4317
4318 ASM_OUTPUT_DEF (asm_out_file, name, IDENTIFIER_POINTER (target));
4319 TREE_ASM_WRITTEN (decl) = 1;
4320 #else
4321 #ifdef ASM_OUTPUT_WEAK_ALIAS
4322 if (! DECL_WEAK (decl))
4323 warning ("only weak aliases are supported in this configuration");
4324
4325 ASM_OUTPUT_WEAK_ALIAS (asm_out_file, name, IDENTIFIER_POINTER (target));
4326 TREE_ASM_WRITTEN (decl) = 1;
4327 #else
4328 warning ("alias definitions not supported in this configuration; ignored");
4329 #endif
4330 #endif
4331 }
4332
4333 /* This determines whether or not we support link-once semantics. */
4334 #ifndef SUPPORTS_ONE_ONLY
4335 #ifdef MAKE_DECL_ONE_ONLY
4336 #define SUPPORTS_ONE_ONLY 1
4337 #else
4338 #define SUPPORTS_ONE_ONLY 0
4339 #endif
4340 #endif
4341
4342 /* Returns 1 if the target configuration supports defining public symbols
4343 so that one of them will be chosen at link time instead of generating a
4344 multiply-defined symbol error, whether through the use of weak symbols or
4345 a target-specific mechanism for having duplicates discarded. */
4346
4347 int
4348 supports_one_only ()
4349 {
4350 if (SUPPORTS_ONE_ONLY)
4351 return 1;
4352 return SUPPORTS_WEAK;
4353 }
4354
4355 /* Set up DECL as a public symbol that can be defined in multiple
4356 translation units without generating a linker error. */
4357
4358 void
4359 make_decl_one_only (decl)
4360 tree decl;
4361 {
4362 if (TREE_CODE (decl) != VAR_DECL && TREE_CODE (decl) != FUNCTION_DECL)
4363 abort ();
4364
4365 TREE_PUBLIC (decl) = 1;
4366
4367 if (TREE_CODE (decl) == VAR_DECL
4368 && (DECL_INITIAL (decl) == 0 || DECL_INITIAL (decl) == error_mark_node))
4369 DECL_COMMON (decl) = 1;
4370 else if (SUPPORTS_ONE_ONLY)
4371 {
4372 #ifdef MAKE_DECL_ONE_ONLY
4373 MAKE_DECL_ONE_ONLY (decl);
4374 #endif
4375 DECL_ONE_ONLY (decl) = 1;
4376 }
4377 else if (SUPPORTS_WEAK)
4378 DECL_WEAK (decl) = 1;
4379 else
4380 abort ();
4381 }