1 /* Language-independent node constructors for parse phase of GNU compiler.
2 Copyright (C) 1987, 88, 92-98, 1999 Free Software Foundation, Inc.
4 This file is part of GNU CC.
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)
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.
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. */
22 /* This file contains the low level primitives for operating on tree nodes,
23 including allocation, list operations, interning of identifiers,
24 construction of data type nodes and statement nodes,
25 and construction of type conversion nodes. It also contains
26 tables index by tree code that describe how to take apart
29 It is intended to be language-independent, but occasionally
30 calls language-dependent routines defined (for C) in typecheck.c.
32 The low-level allocation routines oballoc and permalloc
33 are used also for allocating many other kinds of objects
34 by all passes of the compiler. */
45 #define obstack_chunk_alloc xmalloc
46 #define obstack_chunk_free free
47 /* obstack.[ch] explicitly declined to prototype this. */
48 extern int _obstack_allocated_p PROTO ((struct obstack *h, GENERIC_PTR obj));
50 /* Tree nodes of permanent duration are allocated in this obstack.
51 They are the identifier nodes, and everything outside of
52 the bodies and parameters of function definitions. */
54 struct obstack permanent_obstack;
56 /* The initial RTL, and all ..._TYPE nodes, in a function
57 are allocated in this obstack. Usually they are freed at the
58 end of the function, but if the function is inline they are saved.
59 For top-level functions, this is maybepermanent_obstack.
60 Separate obstacks are made for nested functions. */
62 struct obstack *function_maybepermanent_obstack;
64 /* This is the function_maybepermanent_obstack for top-level functions. */
66 struct obstack maybepermanent_obstack;
68 /* The contents of the current function definition are allocated
69 in this obstack, and all are freed at the end of the function.
70 For top-level functions, this is temporary_obstack.
71 Separate obstacks are made for nested functions. */
73 struct obstack *function_obstack;
75 /* This is used for reading initializers of global variables. */
77 struct obstack temporary_obstack;
79 /* The tree nodes of an expression are allocated
80 in this obstack, and all are freed at the end of the expression. */
82 struct obstack momentary_obstack;
84 /* The tree nodes of a declarator are allocated
85 in this obstack, and all are freed when the declarator
88 static struct obstack temp_decl_obstack;
90 /* This points at either permanent_obstack
91 or the current function_maybepermanent_obstack. */
93 struct obstack *saveable_obstack;
95 /* This is same as saveable_obstack during parse and expansion phase;
96 it points to the current function's obstack during optimization.
97 This is the obstack to be used for creating rtl objects. */
99 struct obstack *rtl_obstack;
101 /* This points at either permanent_obstack or the current function_obstack. */
103 struct obstack *current_obstack;
105 /* This points at either permanent_obstack or the current function_obstack
106 or momentary_obstack. */
108 struct obstack *expression_obstack;
110 /* Stack of obstack selections for push_obstacks and pop_obstacks. */
114 struct obstack_stack *next;
115 struct obstack *current;
116 struct obstack *saveable;
117 struct obstack *expression;
121 struct obstack_stack *obstack_stack;
123 /* Obstack for allocating struct obstack_stack entries. */
125 static struct obstack obstack_stack_obstack;
127 /* Addresses of first objects in some obstacks.
128 This is for freeing their entire contents. */
129 char *maybepermanent_firstobj;
130 char *temporary_firstobj;
131 char *momentary_firstobj;
132 char *temp_decl_firstobj;
134 /* This is used to preserve objects (mainly array initializers) that need to
135 live until the end of the current function, but no further. */
136 char *momentary_function_firstobj;
138 /* Nonzero means all ..._TYPE nodes should be allocated permanently. */
140 int all_types_permanent;
142 /* Stack of places to restore the momentary obstack back to. */
144 struct momentary_level
146 /* Pointer back to previous such level. */
147 struct momentary_level *prev;
148 /* First object allocated within this level. */
150 /* Value of expression_obstack saved at entry to this level. */
151 struct obstack *obstack;
154 struct momentary_level *momentary_stack;
156 /* Table indexed by tree code giving a string containing a character
157 classifying the tree code. Possibilities are
158 t, d, s, c, r, <, 1, 2 and e. See tree.def for details. */
160 #define DEFTREECODE(SYM, NAME, TYPE, LENGTH) TYPE,
162 char tree_code_type[MAX_TREE_CODES] = {
167 /* Table indexed by tree code giving number of expression
168 operands beyond the fixed part of the node structure.
169 Not used for types or decls. */
171 #define DEFTREECODE(SYM, NAME, TYPE, LENGTH) LENGTH,
173 int tree_code_length[MAX_TREE_CODES] = {
178 /* Names of tree components.
179 Used for printing out the tree and error messages. */
180 #define DEFTREECODE(SYM, NAME, TYPE, LEN) NAME,
182 const char *tree_code_name[MAX_TREE_CODES] = {
187 /* Statistics-gathering stuff. */
208 int tree_node_counts[(int)all_kinds];
209 int tree_node_sizes[(int)all_kinds];
210 int id_string_size = 0;
212 const char *tree_node_kind_names[] = {
230 /* Hash table for uniquizing IDENTIFIER_NODEs by name. */
232 #define MAX_HASH_TABLE 1009
233 static tree hash_table[MAX_HASH_TABLE]; /* id hash buckets */
235 /* 0 while creating built-in identifiers. */
236 static int do_identifier_warnings;
238 /* Unique id for next decl created. */
239 static int next_decl_uid;
240 /* Unique id for next type created. */
241 static int next_type_uid = 1;
243 /* The language-specific function for alias analysis. If NULL, the
244 language does not do any special alias analysis. */
245 int (*lang_get_alias_set) PROTO((tree));
247 /* Here is how primitive or already-canonicalized types' hash
249 #define TYPE_HASH(TYPE) ((unsigned long) (TYPE) & 0777777)
251 /* Each hash table slot is a bucket containing a chain
252 of these structures. */
256 struct type_hash *next; /* Next structure in the bucket. */
257 int hashcode; /* Hash code of this type. */
258 tree type; /* The type recorded here. */
261 /* Now here is the hash table. When recording a type, it is added
262 to the slot whose index is the hash code mod the table size.
263 Note that the hash table is used for several kinds of types
264 (function types, array types and array index range types, for now).
265 While all these live in the same table, they are completely independent,
266 and the hash code is computed differently for each of these. */
268 #define TYPE_HASH_SIZE 59
269 struct type_hash *type_hash_table[TYPE_HASH_SIZE];
271 static void set_type_quals PROTO((tree, int));
272 static void append_random_chars PROTO((char *));
273 static void build_real_from_int_cst_1 PROTO((PTR));
274 static void mark_type_hash PROTO ((void *));
276 void gcc_obstack_init ();
278 /* If non-null, a language specific helper for unsave_expr_now. */
280 void (*lang_unsave_expr_now) PROTO((tree));
282 /* Init the principal obstacks. */
287 gcc_obstack_init (&obstack_stack_obstack);
288 gcc_obstack_init (&permanent_obstack);
290 gcc_obstack_init (&temporary_obstack);
291 temporary_firstobj = (char *) obstack_alloc (&temporary_obstack, 0);
292 gcc_obstack_init (&momentary_obstack);
293 momentary_firstobj = (char *) obstack_alloc (&momentary_obstack, 0);
294 momentary_function_firstobj = momentary_firstobj;
295 gcc_obstack_init (&maybepermanent_obstack);
296 maybepermanent_firstobj
297 = (char *) obstack_alloc (&maybepermanent_obstack, 0);
298 gcc_obstack_init (&temp_decl_obstack);
299 temp_decl_firstobj = (char *) obstack_alloc (&temp_decl_obstack, 0);
301 function_obstack = &temporary_obstack;
302 function_maybepermanent_obstack = &maybepermanent_obstack;
303 current_obstack = &permanent_obstack;
304 expression_obstack = &permanent_obstack;
305 rtl_obstack = saveable_obstack = &permanent_obstack;
307 /* Init the hash table of identifiers. */
308 bzero ((char *) hash_table, sizeof hash_table);
310 ggc_add_tree_root (hash_table, MAX_HASH_TABLE);
311 ggc_add_root (type_hash_table, TYPE_HASH_SIZE,
312 sizeof(struct type_hash *),
317 gcc_obstack_init (obstack)
318 struct obstack *obstack;
320 /* Let particular systems override the size of a chunk. */
321 #ifndef OBSTACK_CHUNK_SIZE
322 #define OBSTACK_CHUNK_SIZE 0
324 /* Let them override the alloc and free routines too. */
325 #ifndef OBSTACK_CHUNK_ALLOC
326 #define OBSTACK_CHUNK_ALLOC xmalloc
328 #ifndef OBSTACK_CHUNK_FREE
329 #define OBSTACK_CHUNK_FREE free
331 _obstack_begin (obstack, OBSTACK_CHUNK_SIZE, 0,
332 (void *(*) ()) OBSTACK_CHUNK_ALLOC,
333 (void (*) ()) OBSTACK_CHUNK_FREE);
336 /* Save all variables describing the current status into the structure
337 *P. This function is called whenever we start compiling one
338 function in the midst of compiling another. For example, when
339 compiling a nested function, or, in C++, a template instantiation
340 that is required by the function we are currently compiling.
342 CONTEXT is the decl_function_context for the function we're about to
343 compile; if it isn't current_function_decl, we have to play some games. */
349 p->all_types_permanent = all_types_permanent;
350 p->momentary_stack = momentary_stack;
351 p->maybepermanent_firstobj = maybepermanent_firstobj;
352 p->temporary_firstobj = temporary_firstobj;
353 p->momentary_firstobj = momentary_firstobj;
354 p->momentary_function_firstobj = momentary_function_firstobj;
355 p->function_obstack = function_obstack;
356 p->function_maybepermanent_obstack = function_maybepermanent_obstack;
357 p->current_obstack = current_obstack;
358 p->expression_obstack = expression_obstack;
359 p->saveable_obstack = saveable_obstack;
360 p->rtl_obstack = rtl_obstack;
362 function_maybepermanent_obstack
363 = (struct obstack *) xmalloc (sizeof (struct obstack));
364 gcc_obstack_init (function_maybepermanent_obstack);
365 maybepermanent_firstobj
366 = (char *) obstack_finish (function_maybepermanent_obstack);
368 function_obstack = (struct obstack *) xmalloc (sizeof (struct obstack));
369 gcc_obstack_init (function_obstack);
371 current_obstack = &permanent_obstack;
372 expression_obstack = &permanent_obstack;
373 rtl_obstack = saveable_obstack = &permanent_obstack;
375 temporary_firstobj = (char *) obstack_alloc (&temporary_obstack, 0);
376 momentary_firstobj = (char *) obstack_finish (&momentary_obstack);
377 momentary_function_firstobj = momentary_firstobj;
380 /* Restore all variables describing the current status from the structure *P.
381 This is used after a nested function. */
384 restore_tree_status (p)
387 all_types_permanent = p->all_types_permanent;
388 momentary_stack = p->momentary_stack;
390 obstack_free (&momentary_obstack, momentary_function_firstobj);
392 /* Free saveable storage used by the function just compiled and not
394 obstack_free (function_maybepermanent_obstack, maybepermanent_firstobj);
396 obstack_free (&temporary_obstack, temporary_firstobj);
397 obstack_free (&momentary_obstack, momentary_function_firstobj);
399 obstack_free (function_obstack, 0);
401 if (obstack_empty_p (function_maybepermanent_obstack))
402 free (function_maybepermanent_obstack);
403 free (function_obstack);
405 temporary_firstobj = p->temporary_firstobj;
406 momentary_firstobj = p->momentary_firstobj;
407 momentary_function_firstobj = p->momentary_function_firstobj;
408 maybepermanent_firstobj = p->maybepermanent_firstobj;
409 function_obstack = p->function_obstack;
410 function_maybepermanent_obstack = p->function_maybepermanent_obstack;
411 current_obstack = p->current_obstack;
412 expression_obstack = p->expression_obstack;
413 saveable_obstack = p->saveable_obstack;
414 rtl_obstack = p->rtl_obstack;
417 /* Start allocating on the temporary (per function) obstack.
418 This is done in start_function before parsing the function body,
419 and before each initialization at top level, and to go back
420 to temporary allocation after doing permanent_allocation. */
423 temporary_allocation ()
425 /* Note that function_obstack at top level points to temporary_obstack.
426 But within a nested function context, it is a separate obstack. */
427 current_obstack = function_obstack;
428 expression_obstack = function_obstack;
429 rtl_obstack = saveable_obstack = function_maybepermanent_obstack;
433 /* Start allocating on the permanent obstack but don't
434 free the temporary data. After calling this, call
435 `permanent_allocation' to fully resume permanent allocation status. */
438 end_temporary_allocation ()
440 current_obstack = &permanent_obstack;
441 expression_obstack = &permanent_obstack;
442 rtl_obstack = saveable_obstack = &permanent_obstack;
445 /* Resume allocating on the temporary obstack, undoing
446 effects of `end_temporary_allocation'. */
449 resume_temporary_allocation ()
451 current_obstack = function_obstack;
452 expression_obstack = function_obstack;
453 rtl_obstack = saveable_obstack = function_maybepermanent_obstack;
456 /* While doing temporary allocation, switch to allocating in such a
457 way as to save all nodes if the function is inlined. Call
458 resume_temporary_allocation to go back to ordinary temporary
462 saveable_allocation ()
464 /* Note that function_obstack at top level points to temporary_obstack.
465 But within a nested function context, it is a separate obstack. */
466 expression_obstack = current_obstack = saveable_obstack;
469 /* Switch to current obstack CURRENT and maybepermanent obstack SAVEABLE,
470 recording the previously current obstacks on a stack.
471 This does not free any storage in any obstack. */
474 push_obstacks (current, saveable)
475 struct obstack *current, *saveable;
477 struct obstack_stack *p;
479 p = (struct obstack_stack *) obstack_alloc (&obstack_stack_obstack,
480 (sizeof (struct obstack_stack)));
482 p->current = current_obstack;
483 p->saveable = saveable_obstack;
484 p->expression = expression_obstack;
485 p->rtl = rtl_obstack;
486 p->next = obstack_stack;
489 current_obstack = current;
490 expression_obstack = current;
491 rtl_obstack = saveable_obstack = saveable;
494 /* Save the current set of obstacks, but don't change them. */
497 push_obstacks_nochange ()
499 struct obstack_stack *p;
501 p = (struct obstack_stack *) obstack_alloc (&obstack_stack_obstack,
502 (sizeof (struct obstack_stack)));
504 p->current = current_obstack;
505 p->saveable = saveable_obstack;
506 p->expression = expression_obstack;
507 p->rtl = rtl_obstack;
508 p->next = obstack_stack;
512 /* Pop the obstack selection stack. */
517 struct obstack_stack *p;
520 obstack_stack = p->next;
522 current_obstack = p->current;
523 saveable_obstack = p->saveable;
524 expression_obstack = p->expression;
525 rtl_obstack = p->rtl;
527 obstack_free (&obstack_stack_obstack, p);
530 /* Nonzero if temporary allocation is currently in effect.
531 Zero if currently doing permanent allocation. */
534 allocation_temporary_p ()
536 return current_obstack != &permanent_obstack;
539 /* Go back to allocating on the permanent obstack
540 and free everything in the temporary obstack.
542 FUNCTION_END is true only if we have just finished compiling a function.
543 In that case, we also free preserved initial values on the momentary
547 permanent_allocation (function_end)
550 /* Free up previous temporary obstack data */
551 obstack_free (&temporary_obstack, temporary_firstobj);
554 obstack_free (&momentary_obstack, momentary_function_firstobj);
555 momentary_firstobj = momentary_function_firstobj;
558 obstack_free (&momentary_obstack, momentary_firstobj);
559 obstack_free (function_maybepermanent_obstack, maybepermanent_firstobj);
560 obstack_free (&temp_decl_obstack, temp_decl_firstobj);
562 current_obstack = &permanent_obstack;
563 expression_obstack = &permanent_obstack;
564 rtl_obstack = saveable_obstack = &permanent_obstack;
567 /* Save permanently everything on the maybepermanent_obstack. */
572 maybepermanent_firstobj
573 = (char *) obstack_alloc (function_maybepermanent_obstack, 0);
577 preserve_initializer ()
579 struct momentary_level *tem;
583 = (char *) obstack_alloc (&temporary_obstack, 0);
584 maybepermanent_firstobj
585 = (char *) obstack_alloc (function_maybepermanent_obstack, 0);
587 old_momentary = momentary_firstobj;
589 = (char *) obstack_alloc (&momentary_obstack, 0);
590 if (momentary_firstobj != old_momentary)
591 for (tem = momentary_stack; tem; tem = tem->prev)
592 tem->base = momentary_firstobj;
595 /* Start allocating new rtl in current_obstack.
596 Use resume_temporary_allocation
597 to go back to allocating rtl in saveable_obstack. */
600 rtl_in_current_obstack ()
602 rtl_obstack = current_obstack;
605 /* Start allocating rtl from saveable_obstack. Intended to be used after
606 a call to push_obstacks_nochange. */
609 rtl_in_saveable_obstack ()
611 rtl_obstack = saveable_obstack;
614 /* Allocate SIZE bytes in the current obstack
615 and return a pointer to them.
616 In practice the current obstack is always the temporary one. */
622 return (char *) obstack_alloc (current_obstack, size);
625 /* Free the object PTR in the current obstack
626 as well as everything allocated since PTR.
627 In practice the current obstack is always the temporary one. */
633 obstack_free (current_obstack, ptr);
636 /* Allocate SIZE bytes in the permanent obstack
637 and return a pointer to them. */
643 return (char *) obstack_alloc (&permanent_obstack, size);
646 /* Allocate NELEM items of SIZE bytes in the permanent obstack
647 and return a pointer to them. The storage is cleared before
648 returning the value. */
651 perm_calloc (nelem, size)
655 char *rval = (char *) obstack_alloc (&permanent_obstack, nelem * size);
656 bzero (rval, nelem * size);
660 /* Allocate SIZE bytes in the saveable obstack
661 and return a pointer to them. */
667 return (char *) obstack_alloc (saveable_obstack, size);
670 /* Allocate SIZE bytes in the expression obstack
671 and return a pointer to them. */
677 return (char *) obstack_alloc (expression_obstack, size);
680 /* Print out which obstack an object is in. */
683 print_obstack_name (object, file, prefix)
688 struct obstack *obstack = NULL;
689 const char *obstack_name = NULL;
692 for (p = outer_function_chain; p; p = p->next)
694 if (_obstack_allocated_p (p->function_obstack, object))
696 obstack = p->function_obstack;
697 obstack_name = "containing function obstack";
699 if (_obstack_allocated_p (p->function_maybepermanent_obstack, object))
701 obstack = p->function_maybepermanent_obstack;
702 obstack_name = "containing function maybepermanent obstack";
706 if (_obstack_allocated_p (&obstack_stack_obstack, object))
708 obstack = &obstack_stack_obstack;
709 obstack_name = "obstack_stack_obstack";
711 else if (_obstack_allocated_p (function_obstack, object))
713 obstack = function_obstack;
714 obstack_name = "function obstack";
716 else if (_obstack_allocated_p (&permanent_obstack, object))
718 obstack = &permanent_obstack;
719 obstack_name = "permanent_obstack";
721 else if (_obstack_allocated_p (&momentary_obstack, object))
723 obstack = &momentary_obstack;
724 obstack_name = "momentary_obstack";
726 else if (_obstack_allocated_p (function_maybepermanent_obstack, object))
728 obstack = function_maybepermanent_obstack;
729 obstack_name = "function maybepermanent obstack";
731 else if (_obstack_allocated_p (&temp_decl_obstack, object))
733 obstack = &temp_decl_obstack;
734 obstack_name = "temp_decl_obstack";
737 /* Check to see if the object is in the free area of the obstack. */
740 if (object >= obstack->next_free
741 && object < obstack->chunk_limit)
742 fprintf (file, "%s in free portion of obstack %s",
743 prefix, obstack_name);
745 fprintf (file, "%s allocated from %s", prefix, obstack_name);
748 fprintf (file, "%s not allocated from any obstack", prefix);
752 debug_obstack (object)
755 print_obstack_name (object, stderr, "object");
756 fprintf (stderr, ".\n");
759 /* Return 1 if OBJ is in the permanent obstack.
760 This is slow, and should be used only for debugging.
761 Use TREE_PERMANENT for other purposes. */
764 object_permanent_p (obj)
767 return _obstack_allocated_p (&permanent_obstack, obj);
770 /* Start a level of momentary allocation.
771 In C, each compound statement has its own level
772 and that level is freed at the end of each statement.
773 All expression nodes are allocated in the momentary allocation level. */
778 struct momentary_level *tem
779 = (struct momentary_level *) obstack_alloc (&momentary_obstack,
780 sizeof (struct momentary_level));
781 tem->prev = momentary_stack;
782 tem->base = (char *) obstack_base (&momentary_obstack);
783 tem->obstack = expression_obstack;
784 momentary_stack = tem;
785 expression_obstack = &momentary_obstack;
788 /* Set things up so the next clear_momentary will only clear memory
789 past our present position in momentary_obstack. */
792 preserve_momentary ()
794 momentary_stack->base = (char *) obstack_base (&momentary_obstack);
797 /* Free all the storage in the current momentary-allocation level.
798 In C, this happens at the end of each statement. */
803 obstack_free (&momentary_obstack, momentary_stack->base);
806 /* Discard a level of momentary allocation.
807 In C, this happens at the end of each compound statement.
808 Restore the status of expression node allocation
809 that was in effect before this level was created. */
814 struct momentary_level *tem = momentary_stack;
815 momentary_stack = tem->prev;
816 expression_obstack = tem->obstack;
817 /* We can't free TEM from the momentary_obstack, because there might
818 be objects above it which have been saved. We can free back to the
819 stack of the level we are popping off though. */
820 obstack_free (&momentary_obstack, tem->base);
823 /* Pop back to the previous level of momentary allocation,
824 but don't free any momentary data just yet. */
827 pop_momentary_nofree ()
829 struct momentary_level *tem = momentary_stack;
830 momentary_stack = tem->prev;
831 expression_obstack = tem->obstack;
834 /* Call when starting to parse a declaration:
835 make expressions in the declaration last the length of the function.
836 Returns an argument that should be passed to resume_momentary later. */
841 register int tem = expression_obstack == &momentary_obstack;
842 expression_obstack = saveable_obstack;
846 /* Call when finished parsing a declaration:
847 restore the treatment of node-allocation that was
848 in effect before the suspension.
849 YES should be the value previously returned by suspend_momentary. */
852 resume_momentary (yes)
856 expression_obstack = &momentary_obstack;
859 /* Init the tables indexed by tree code.
860 Note that languages can add to these tables to define their own codes. */
868 /* Return a newly allocated node of code CODE.
869 Initialize the node's unique id and its TREE_PERMANENT flag.
870 For decl and type nodes, some other fields are initialized.
871 The rest of the node is initialized to zero.
873 Achoo! I got a code in the node. */
880 register int type = TREE_CODE_CLASS (code);
881 register int length = 0;
882 register struct obstack *obstack = current_obstack;
883 #ifdef GATHER_STATISTICS
884 register tree_node_kind kind;
889 case 'd': /* A decl node */
890 #ifdef GATHER_STATISTICS
893 length = sizeof (struct tree_decl);
894 /* All decls in an inline function need to be saved. */
895 if (obstack != &permanent_obstack)
896 obstack = saveable_obstack;
898 /* PARM_DECLs go on the context of the parent. If this is a nested
899 function, then we must allocate the PARM_DECL on the parent's
900 obstack, so that they will live to the end of the parent's
901 closing brace. This is necessary in case we try to inline the
902 function into its parent.
904 PARM_DECLs of top-level functions do not have this problem. However,
905 we allocate them where we put the FUNCTION_DECL for languages such as
906 Ada that need to consult some flags in the PARM_DECLs of the function
909 See comment in restore_tree_status for why we can't put this
910 in function_obstack. */
911 if (code == PARM_DECL && obstack != &permanent_obstack)
914 if (current_function_decl)
915 context = decl_function_context (current_function_decl);
919 = find_function_data (context)->function_maybepermanent_obstack;
923 case 't': /* a type node */
924 #ifdef GATHER_STATISTICS
927 length = sizeof (struct tree_type);
928 /* All data types are put where we can preserve them if nec. */
929 if (obstack != &permanent_obstack)
930 obstack = all_types_permanent ? &permanent_obstack : saveable_obstack;
933 case 'b': /* a lexical block */
934 #ifdef GATHER_STATISTICS
937 length = sizeof (struct tree_block);
938 /* All BLOCK nodes are put where we can preserve them if nec. */
939 if (obstack != &permanent_obstack)
940 obstack = saveable_obstack;
943 case 's': /* an expression with side effects */
944 #ifdef GATHER_STATISTICS
948 case 'r': /* a reference */
949 #ifdef GATHER_STATISTICS
953 case 'e': /* an expression */
954 case '<': /* a comparison expression */
955 case '1': /* a unary arithmetic expression */
956 case '2': /* a binary arithmetic expression */
957 #ifdef GATHER_STATISTICS
961 obstack = expression_obstack;
962 /* All BIND_EXPR nodes are put where we can preserve them if nec. */
963 if (code == BIND_EXPR && obstack != &permanent_obstack)
964 obstack = saveable_obstack;
965 length = sizeof (struct tree_exp)
966 + (tree_code_length[(int) code] - 1) * sizeof (char *);
969 case 'c': /* a constant */
970 #ifdef GATHER_STATISTICS
973 obstack = expression_obstack;
975 /* We can't use tree_code_length for INTEGER_CST, since the number of
976 words is machine-dependent due to varying length of HOST_WIDE_INT,
977 which might be wider than a pointer (e.g., long long). Similarly
978 for REAL_CST, since the number of words is machine-dependent due
979 to varying size and alignment of `double'. */
981 if (code == INTEGER_CST)
982 length = sizeof (struct tree_int_cst);
983 else if (code == REAL_CST)
984 length = sizeof (struct tree_real_cst);
986 length = sizeof (struct tree_common)
987 + tree_code_length[(int) code] * sizeof (char *);
990 case 'x': /* something random, like an identifier. */
991 #ifdef GATHER_STATISTICS
992 if (code == IDENTIFIER_NODE)
994 else if (code == OP_IDENTIFIER)
996 else if (code == TREE_VEC)
1001 length = sizeof (struct tree_common)
1002 + tree_code_length[(int) code] * sizeof (char *);
1003 /* Identifier nodes are always permanent since they are
1004 unique in a compiler run. */
1005 if (code == IDENTIFIER_NODE) obstack = &permanent_obstack;
1013 t = ggc_alloc_tree (length);
1016 t = (tree) obstack_alloc (obstack, length);
1017 bzero ((PTR) t, length);
1020 #ifdef GATHER_STATISTICS
1021 tree_node_counts[(int)kind]++;
1022 tree_node_sizes[(int)kind] += length;
1025 TREE_SET_CODE (t, code);
1026 if (obstack == &permanent_obstack)
1027 TREE_PERMANENT (t) = 1;
1032 TREE_SIDE_EFFECTS (t) = 1;
1033 TREE_TYPE (t) = void_type_node;
1037 if (code != FUNCTION_DECL)
1039 DECL_IN_SYSTEM_HEADER (t)
1040 = in_system_header && (obstack == &permanent_obstack);
1041 DECL_SOURCE_LINE (t) = lineno;
1042 DECL_SOURCE_FILE (t) = (input_filename) ? input_filename : "<built-in>";
1043 DECL_UID (t) = next_decl_uid++;
1044 /* Note that we have not yet computed the alias set for this
1046 DECL_POINTER_ALIAS_SET (t) = -1;
1050 TYPE_UID (t) = next_type_uid++;
1052 TYPE_MAIN_VARIANT (t) = t;
1053 TYPE_OBSTACK (t) = obstack;
1054 TYPE_ATTRIBUTES (t) = NULL_TREE;
1055 #ifdef SET_DEFAULT_TYPE_ATTRIBUTES
1056 SET_DEFAULT_TYPE_ATTRIBUTES (t);
1058 /* Note that we have not yet computed the alias set for this
1060 TYPE_ALIAS_SET (t) = -1;
1064 TREE_CONSTANT (t) = 1;
1071 /* Return a new node with the same contents as NODE except that its
1072 TREE_CHAIN is zero and it has a fresh uid. Unlike make_node, this
1073 function always performs the allocation on the CURRENT_OBSTACK;
1074 it's up to the caller to pick the right obstack before calling this
1082 register enum tree_code code = TREE_CODE (node);
1083 register int length = 0;
1085 switch (TREE_CODE_CLASS (code))
1087 case 'd': /* A decl node */
1088 length = sizeof (struct tree_decl);
1091 case 't': /* a type node */
1092 length = sizeof (struct tree_type);
1095 case 'b': /* a lexical block node */
1096 length = sizeof (struct tree_block);
1099 case 'r': /* a reference */
1100 case 'e': /* an expression */
1101 case 's': /* an expression with side effects */
1102 case '<': /* a comparison expression */
1103 case '1': /* a unary arithmetic expression */
1104 case '2': /* a binary arithmetic expression */
1105 length = sizeof (struct tree_exp)
1106 + (tree_code_length[(int) code] - 1) * sizeof (char *);
1109 case 'c': /* a constant */
1110 /* We can't use tree_code_length for INTEGER_CST, since the number of
1111 words is machine-dependent due to varying length of HOST_WIDE_INT,
1112 which might be wider than a pointer (e.g., long long). Similarly
1113 for REAL_CST, since the number of words is machine-dependent due
1114 to varying size and alignment of `double'. */
1115 if (code == INTEGER_CST)
1116 length = sizeof (struct tree_int_cst);
1117 else if (code == REAL_CST)
1118 length = sizeof (struct tree_real_cst);
1120 length = (sizeof (struct tree_common)
1121 + tree_code_length[(int) code] * sizeof (char *));
1124 case 'x': /* something random, like an identifier. */
1125 length = sizeof (struct tree_common)
1126 + tree_code_length[(int) code] * sizeof (char *);
1127 if (code == TREE_VEC)
1128 length += (TREE_VEC_LENGTH (node) - 1) * sizeof (char *);
1132 t = ggc_alloc_tree (length);
1134 t = (tree) obstack_alloc (current_obstack, length);
1135 memcpy (t, node, length);
1137 /* EXPR_WITH_FILE_LOCATION must keep filename info stored in TREE_CHAIN */
1138 if (TREE_CODE (node) != EXPR_WITH_FILE_LOCATION)
1140 TREE_ASM_WRITTEN (t) = 0;
1142 if (TREE_CODE_CLASS (code) == 'd')
1143 DECL_UID (t) = next_decl_uid++;
1144 else if (TREE_CODE_CLASS (code) == 't')
1146 TYPE_UID (t) = next_type_uid++;
1147 TYPE_OBSTACK (t) = current_obstack;
1149 /* The following is so that the debug code for
1150 the copy is different from the original type.
1151 The two statements usually duplicate each other
1152 (because they clear fields of the same union),
1153 but the optimizer should catch that. */
1154 TYPE_SYMTAB_POINTER (t) = 0;
1155 TYPE_SYMTAB_ADDRESS (t) = 0;
1158 TREE_PERMANENT (t) = (current_obstack == &permanent_obstack);
1163 /* Return a copy of a chain of nodes, chained through the TREE_CHAIN field.
1164 For example, this can copy a list made of TREE_LIST nodes. */
1171 register tree prev, next;
1176 head = prev = copy_node (list);
1177 next = TREE_CHAIN (list);
1180 TREE_CHAIN (prev) = copy_node (next);
1181 prev = TREE_CHAIN (prev);
1182 next = TREE_CHAIN (next);
1189 /* Return an IDENTIFIER_NODE whose name is TEXT (a null-terminated string).
1190 If an identifier with that name has previously been referred to,
1191 the same node is returned this time. */
1194 get_identifier (text)
1195 register const char *text;
1200 register int len, hash_len;
1202 /* Compute length of text in len. */
1203 len = strlen (text);
1205 /* Decide how much of that length to hash on */
1207 if (warn_id_clash && (unsigned)len > id_clash_len)
1208 hash_len = id_clash_len;
1210 /* Compute hash code */
1211 hi = hash_len * 613 + (unsigned) text[0];
1212 for (i = 1; i < hash_len; i += 2)
1213 hi = ((hi * 613) + (unsigned) (text[i]));
1215 hi &= (1 << HASHBITS) - 1;
1216 hi %= MAX_HASH_TABLE;
1218 /* Search table for identifier */
1219 for (idp = hash_table[hi]; idp; idp = TREE_CHAIN (idp))
1220 if (IDENTIFIER_LENGTH (idp) == len
1221 && IDENTIFIER_POINTER (idp)[0] == text[0]
1222 && !bcmp (IDENTIFIER_POINTER (idp), text, len))
1223 return idp; /* <-- return if found */
1225 /* Not found; optionally warn about a similar identifier */
1226 if (warn_id_clash && do_identifier_warnings && (unsigned)len >= id_clash_len)
1227 for (idp = hash_table[hi]; idp; idp = TREE_CHAIN (idp))
1228 if (!strncmp (IDENTIFIER_POINTER (idp), text, id_clash_len))
1230 warning ("`%s' and `%s' identical in first %d characters",
1231 IDENTIFIER_POINTER (idp), text, id_clash_len);
1235 if (tree_code_length[(int) IDENTIFIER_NODE] < 0)
1236 abort (); /* set_identifier_size hasn't been called. */
1238 /* Not found, create one, add to chain */
1239 idp = make_node (IDENTIFIER_NODE);
1240 IDENTIFIER_LENGTH (idp) = len;
1241 #ifdef GATHER_STATISTICS
1242 id_string_size += len;
1246 IDENTIFIER_POINTER (idp) = ggc_alloc_string (text, len);
1248 IDENTIFIER_POINTER (idp) = obstack_copy0 (&permanent_obstack, text, len);
1250 TREE_CHAIN (idp) = hash_table[hi];
1251 hash_table[hi] = idp;
1252 return idp; /* <-- return if created */
1255 /* If an identifier with the name TEXT (a null-terminated string) has
1256 previously been referred to, return that node; otherwise return
1260 maybe_get_identifier (text)
1261 register const char *text;
1266 register int len, hash_len;
1268 /* Compute length of text in len. */
1269 len = strlen (text);
1271 /* Decide how much of that length to hash on */
1273 if (warn_id_clash && (unsigned)len > id_clash_len)
1274 hash_len = id_clash_len;
1276 /* Compute hash code */
1277 hi = hash_len * 613 + (unsigned) text[0];
1278 for (i = 1; i < hash_len; i += 2)
1279 hi = ((hi * 613) + (unsigned) (text[i]));
1281 hi &= (1 << HASHBITS) - 1;
1282 hi %= MAX_HASH_TABLE;
1284 /* Search table for identifier */
1285 for (idp = hash_table[hi]; idp; idp = TREE_CHAIN (idp))
1286 if (IDENTIFIER_LENGTH (idp) == len
1287 && IDENTIFIER_POINTER (idp)[0] == text[0]
1288 && !bcmp (IDENTIFIER_POINTER (idp), text, len))
1289 return idp; /* <-- return if found */
1294 /* Enable warnings on similar identifiers (if requested).
1295 Done after the built-in identifiers are created. */
1298 start_identifier_warnings ()
1300 do_identifier_warnings = 1;
1303 /* Record the size of an identifier node for the language in use.
1304 SIZE is the total size in bytes.
1305 This is called by the language-specific files. This must be
1306 called before allocating any identifiers. */
1309 set_identifier_size (size)
1312 tree_code_length[(int) IDENTIFIER_NODE]
1313 = (size - sizeof (struct tree_common)) / sizeof (tree);
1316 /* Return a newly constructed INTEGER_CST node whose constant value
1317 is specified by the two ints LOW and HI.
1318 The TREE_TYPE is set to `int'.
1320 This function should be used via the `build_int_2' macro. */
1323 build_int_2_wide (low, hi)
1324 HOST_WIDE_INT low, hi;
1326 register tree t = make_node (INTEGER_CST);
1327 TREE_INT_CST_LOW (t) = low;
1328 TREE_INT_CST_HIGH (t) = hi;
1329 TREE_TYPE (t) = integer_type_node;
1333 /* Return a new REAL_CST node whose type is TYPE and value is D. */
1336 build_real (type, d)
1343 /* Check for valid float value for this type on this target machine;
1344 if not, can print error message and store a valid value in D. */
1345 #ifdef CHECK_FLOAT_VALUE
1346 CHECK_FLOAT_VALUE (TYPE_MODE (type), d, overflow);
1349 v = make_node (REAL_CST);
1350 TREE_TYPE (v) = type;
1351 TREE_REAL_CST (v) = d;
1352 TREE_OVERFLOW (v) = TREE_CONSTANT_OVERFLOW (v) = overflow;
1356 /* Return a new REAL_CST node whose type is TYPE
1357 and whose value is the integer value of the INTEGER_CST node I. */
1359 #if !defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
1362 real_value_from_int_cst (type, i)
1367 #ifdef REAL_ARITHMETIC
1368 if (! TREE_UNSIGNED (TREE_TYPE (i)))
1369 REAL_VALUE_FROM_INT (d, TREE_INT_CST_LOW (i), TREE_INT_CST_HIGH (i),
1372 REAL_VALUE_FROM_UNSIGNED_INT (d, TREE_INT_CST_LOW (i),
1373 TREE_INT_CST_HIGH (i), TYPE_MODE (type));
1374 #else /* not REAL_ARITHMETIC */
1375 /* Some 386 compilers mishandle unsigned int to float conversions,
1376 so introduce a temporary variable E to avoid those bugs. */
1377 if (TREE_INT_CST_HIGH (i) < 0 && ! TREE_UNSIGNED (TREE_TYPE (i)))
1381 d = (double) (~ TREE_INT_CST_HIGH (i));
1382 e = ((double) ((HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2))
1383 * (double) ((HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2)));
1385 e = (double) (unsigned HOST_WIDE_INT) (~ TREE_INT_CST_LOW (i));
1393 d = (double) (unsigned HOST_WIDE_INT) TREE_INT_CST_HIGH (i);
1394 e = ((double) ((HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2))
1395 * (double) ((HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2)));
1397 e = (double) (unsigned HOST_WIDE_INT) TREE_INT_CST_LOW (i);
1400 #endif /* not REAL_ARITHMETIC */
1413 build_real_from_int_cst_1 (data)
1416 struct brfic_args * args = (struct brfic_args *) data;
1418 #ifdef REAL_ARITHMETIC
1419 args->d = real_value_from_int_cst (args->type, args->i);
1422 REAL_VALUE_TRUNCATE (TYPE_MODE (args->type),
1423 real_value_from_int_cst (args->type, args->i));
1427 /* This function can't be implemented if we can't do arithmetic
1428 on the float representation. */
1431 build_real_from_int_cst (type, i)
1436 int overflow = TREE_OVERFLOW (i);
1438 struct brfic_args args;
1440 v = make_node (REAL_CST);
1441 TREE_TYPE (v) = type;
1443 /* Setup input for build_real_from_int_cst_1() */
1447 if (do_float_handler (build_real_from_int_cst_1, (PTR) &args))
1449 /* Receive output from build_real_from_int_cst_1() */
1454 /* We got an exception from build_real_from_int_cst_1() */
1459 /* Check for valid float value for this type on this target machine. */
1461 #ifdef CHECK_FLOAT_VALUE
1462 CHECK_FLOAT_VALUE (TYPE_MODE (type), d, overflow);
1465 TREE_REAL_CST (v) = d;
1466 TREE_OVERFLOW (v) = TREE_CONSTANT_OVERFLOW (v) = overflow;
1470 #endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */
1472 /* Return a newly constructed STRING_CST node whose value is
1473 the LEN characters at STR.
1474 The TREE_TYPE is not initialized. */
1477 build_string (len, str)
1481 /* Put the string in saveable_obstack since it will be placed in the RTL
1482 for an "asm" statement and will also be kept around a while if
1483 deferring constant output in varasm.c. */
1485 register tree s = make_node (STRING_CST);
1486 TREE_STRING_LENGTH (s) = len;
1488 TREE_STRING_POINTER (s) = ggc_alloc_string (str, len);
1490 TREE_STRING_POINTER (s) = obstack_copy0 (saveable_obstack, str, len);
1494 /* Return a newly constructed COMPLEX_CST node whose value is
1495 specified by the real and imaginary parts REAL and IMAG.
1496 Both REAL and IMAG should be constant nodes. TYPE, if specified,
1497 will be the type of the COMPLEX_CST; otherwise a new type will be made. */
1500 build_complex (type, real, imag)
1504 register tree t = make_node (COMPLEX_CST);
1506 TREE_REALPART (t) = real;
1507 TREE_IMAGPART (t) = imag;
1508 TREE_TYPE (t) = type ? type : build_complex_type (TREE_TYPE (real));
1509 TREE_OVERFLOW (t) = TREE_OVERFLOW (real) | TREE_OVERFLOW (imag);
1510 TREE_CONSTANT_OVERFLOW (t)
1511 = TREE_CONSTANT_OVERFLOW (real) | TREE_CONSTANT_OVERFLOW (imag);
1515 /* Build a newly constructed TREE_VEC node of length LEN. */
1522 register int length = (len-1) * sizeof (tree) + sizeof (struct tree_vec);
1523 register struct obstack *obstack = current_obstack;
1525 #ifdef GATHER_STATISTICS
1526 tree_node_counts[(int)vec_kind]++;
1527 tree_node_sizes[(int)vec_kind] += length;
1531 t = ggc_alloc_tree (length);
1534 t = (tree) obstack_alloc (obstack, length);
1535 bzero ((PTR) t, length);
1538 TREE_SET_CODE (t, TREE_VEC);
1539 TREE_VEC_LENGTH (t) = len;
1540 if (obstack == &permanent_obstack)
1541 TREE_PERMANENT (t) = 1;
1546 /* Return 1 if EXPR is the integer constant zero or a complex constant
1550 integer_zerop (expr)
1555 return ((TREE_CODE (expr) == INTEGER_CST
1556 && ! TREE_CONSTANT_OVERFLOW (expr)
1557 && TREE_INT_CST_LOW (expr) == 0
1558 && TREE_INT_CST_HIGH (expr) == 0)
1559 || (TREE_CODE (expr) == COMPLEX_CST
1560 && integer_zerop (TREE_REALPART (expr))
1561 && integer_zerop (TREE_IMAGPART (expr))));
1564 /* Return 1 if EXPR is the integer constant one or the corresponding
1565 complex constant. */
1573 return ((TREE_CODE (expr) == INTEGER_CST
1574 && ! TREE_CONSTANT_OVERFLOW (expr)
1575 && TREE_INT_CST_LOW (expr) == 1
1576 && TREE_INT_CST_HIGH (expr) == 0)
1577 || (TREE_CODE (expr) == COMPLEX_CST
1578 && integer_onep (TREE_REALPART (expr))
1579 && integer_zerop (TREE_IMAGPART (expr))));
1582 /* Return 1 if EXPR is an integer containing all 1's in as much precision as
1583 it contains. Likewise for the corresponding complex constant. */
1586 integer_all_onesp (expr)
1594 if (TREE_CODE (expr) == COMPLEX_CST
1595 && integer_all_onesp (TREE_REALPART (expr))
1596 && integer_zerop (TREE_IMAGPART (expr)))
1599 else if (TREE_CODE (expr) != INTEGER_CST
1600 || TREE_CONSTANT_OVERFLOW (expr))
1603 uns = TREE_UNSIGNED (TREE_TYPE (expr));
1605 return TREE_INT_CST_LOW (expr) == -1 && TREE_INT_CST_HIGH (expr) == -1;
1607 /* Note that using TYPE_PRECISION here is wrong. We care about the
1608 actual bits, not the (arbitrary) range of the type. */
1609 prec = GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (expr)));
1610 if (prec >= HOST_BITS_PER_WIDE_INT)
1612 int high_value, shift_amount;
1614 shift_amount = prec - HOST_BITS_PER_WIDE_INT;
1616 if (shift_amount > HOST_BITS_PER_WIDE_INT)
1617 /* Can not handle precisions greater than twice the host int size. */
1619 else if (shift_amount == HOST_BITS_PER_WIDE_INT)
1620 /* Shifting by the host word size is undefined according to the ANSI
1621 standard, so we must handle this as a special case. */
1624 high_value = ((HOST_WIDE_INT) 1 << shift_amount) - 1;
1626 return TREE_INT_CST_LOW (expr) == -1
1627 && TREE_INT_CST_HIGH (expr) == high_value;
1630 return TREE_INT_CST_LOW (expr) == ((HOST_WIDE_INT) 1 << prec) - 1;
1633 /* Return 1 if EXPR is an integer constant that is a power of 2 (i.e., has only
1637 integer_pow2p (expr)
1641 HOST_WIDE_INT high, low;
1645 if (TREE_CODE (expr) == COMPLEX_CST
1646 && integer_pow2p (TREE_REALPART (expr))
1647 && integer_zerop (TREE_IMAGPART (expr)))
1650 if (TREE_CODE (expr) != INTEGER_CST || TREE_CONSTANT_OVERFLOW (expr))
1653 prec = (POINTER_TYPE_P (TREE_TYPE (expr))
1654 ? POINTER_SIZE : TYPE_PRECISION (TREE_TYPE (expr)));
1655 high = TREE_INT_CST_HIGH (expr);
1656 low = TREE_INT_CST_LOW (expr);
1658 /* First clear all bits that are beyond the type's precision in case
1659 we've been sign extended. */
1661 if (prec == 2 * HOST_BITS_PER_WIDE_INT)
1663 else if (prec > HOST_BITS_PER_WIDE_INT)
1664 high &= ~((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
1668 if (prec < HOST_BITS_PER_WIDE_INT)
1669 low &= ~((HOST_WIDE_INT) (-1) << prec);
1672 if (high == 0 && low == 0)
1675 return ((high == 0 && (low & (low - 1)) == 0)
1676 || (low == 0 && (high & (high - 1)) == 0));
1679 /* Return the power of two represented by a tree node known to be a
1687 HOST_WIDE_INT high, low;
1691 if (TREE_CODE (expr) == COMPLEX_CST)
1692 return tree_log2 (TREE_REALPART (expr));
1694 prec = (POINTER_TYPE_P (TREE_TYPE (expr))
1695 ? POINTER_SIZE : TYPE_PRECISION (TREE_TYPE (expr)));
1697 high = TREE_INT_CST_HIGH (expr);
1698 low = TREE_INT_CST_LOW (expr);
1700 /* First clear all bits that are beyond the type's precision in case
1701 we've been sign extended. */
1703 if (prec == 2 * HOST_BITS_PER_WIDE_INT)
1705 else if (prec > HOST_BITS_PER_WIDE_INT)
1706 high &= ~((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
1710 if (prec < HOST_BITS_PER_WIDE_INT)
1711 low &= ~((HOST_WIDE_INT) (-1) << prec);
1714 return (high != 0 ? HOST_BITS_PER_WIDE_INT + exact_log2 (high)
1715 : exact_log2 (low));
1718 /* Return 1 if EXPR is the real constant zero. */
1726 return ((TREE_CODE (expr) == REAL_CST
1727 && ! TREE_CONSTANT_OVERFLOW (expr)
1728 && REAL_VALUES_EQUAL (TREE_REAL_CST (expr), dconst0))
1729 || (TREE_CODE (expr) == COMPLEX_CST
1730 && real_zerop (TREE_REALPART (expr))
1731 && real_zerop (TREE_IMAGPART (expr))));
1734 /* Return 1 if EXPR is the real constant one in real or complex form. */
1742 return ((TREE_CODE (expr) == REAL_CST
1743 && ! TREE_CONSTANT_OVERFLOW (expr)
1744 && REAL_VALUES_EQUAL (TREE_REAL_CST (expr), dconst1))
1745 || (TREE_CODE (expr) == COMPLEX_CST
1746 && real_onep (TREE_REALPART (expr))
1747 && real_zerop (TREE_IMAGPART (expr))));
1750 /* Return 1 if EXPR is the real constant two. */
1758 return ((TREE_CODE (expr) == REAL_CST
1759 && ! TREE_CONSTANT_OVERFLOW (expr)
1760 && REAL_VALUES_EQUAL (TREE_REAL_CST (expr), dconst2))
1761 || (TREE_CODE (expr) == COMPLEX_CST
1762 && real_twop (TREE_REALPART (expr))
1763 && real_zerop (TREE_IMAGPART (expr))));
1766 /* Nonzero if EXP is a constant or a cast of a constant. */
1769 really_constant_p (exp)
1772 /* This is not quite the same as STRIP_NOPS. It does more. */
1773 while (TREE_CODE (exp) == NOP_EXPR
1774 || TREE_CODE (exp) == CONVERT_EXPR
1775 || TREE_CODE (exp) == NON_LVALUE_EXPR)
1776 exp = TREE_OPERAND (exp, 0);
1777 return TREE_CONSTANT (exp);
1780 /* Return first list element whose TREE_VALUE is ELEM.
1781 Return 0 if ELEM is not in LIST. */
1784 value_member (elem, list)
1789 if (elem == TREE_VALUE (list))
1791 list = TREE_CHAIN (list);
1796 /* Return first list element whose TREE_PURPOSE is ELEM.
1797 Return 0 if ELEM is not in LIST. */
1800 purpose_member (elem, list)
1805 if (elem == TREE_PURPOSE (list))
1807 list = TREE_CHAIN (list);
1812 /* Return first list element whose BINFO_TYPE is ELEM.
1813 Return 0 if ELEM is not in LIST. */
1816 binfo_member (elem, list)
1821 if (elem == BINFO_TYPE (list))
1823 list = TREE_CHAIN (list);
1828 /* Return nonzero if ELEM is part of the chain CHAIN. */
1831 chain_member (elem, chain)
1838 chain = TREE_CHAIN (chain);
1844 /* Return nonzero if ELEM is equal to TREE_VALUE (CHAIN) for any piece of
1846 /* ??? This function was added for machine specific attributes but is no
1847 longer used. It could be deleted if we could confirm all front ends
1851 chain_member_value (elem, chain)
1856 if (elem == TREE_VALUE (chain))
1858 chain = TREE_CHAIN (chain);
1864 /* Return nonzero if ELEM is equal to TREE_PURPOSE (CHAIN)
1865 for any piece of chain CHAIN. */
1866 /* ??? This function was added for machine specific attributes but is no
1867 longer used. It could be deleted if we could confirm all front ends
1871 chain_member_purpose (elem, chain)
1876 if (elem == TREE_PURPOSE (chain))
1878 chain = TREE_CHAIN (chain);
1884 /* Return the length of a chain of nodes chained through TREE_CHAIN.
1885 We expect a null pointer to mark the end of the chain.
1886 This is the Lisp primitive `length'. */
1893 register int len = 0;
1895 for (tail = t; tail; tail = TREE_CHAIN (tail))
1901 /* Concatenate two chains of nodes (chained through TREE_CHAIN)
1902 by modifying the last node in chain 1 to point to chain 2.
1903 This is the Lisp primitive `nconc'. */
1913 #ifdef ENABLE_CHECKING
1917 for (t1 = op1; TREE_CHAIN (t1); t1 = TREE_CHAIN (t1))
1919 TREE_CHAIN (t1) = op2;
1920 #ifdef ENABLE_CHECKING
1921 for (t2 = op2; t2; t2 = TREE_CHAIN (t2))
1923 abort (); /* Circularity created. */
1930 /* Return the last node in a chain of nodes (chained through TREE_CHAIN). */
1934 register tree chain;
1938 while ((next = TREE_CHAIN (chain)))
1943 /* Reverse the order of elements in the chain T,
1944 and return the new head of the chain (old last element). */
1950 register tree prev = 0, decl, next;
1951 for (decl = t; decl; decl = next)
1953 next = TREE_CHAIN (decl);
1954 TREE_CHAIN (decl) = prev;
1960 /* Given a chain CHAIN of tree nodes,
1961 construct and return a list of those nodes. */
1967 tree result = NULL_TREE;
1968 tree in_tail = chain;
1969 tree out_tail = NULL_TREE;
1973 tree next = tree_cons (NULL_TREE, in_tail, NULL_TREE);
1975 TREE_CHAIN (out_tail) = next;
1979 in_tail = TREE_CHAIN (in_tail);
1985 /* Return a newly created TREE_LIST node whose
1986 purpose and value fields are PARM and VALUE. */
1989 build_tree_list (parm, value)
1992 register tree t = make_node (TREE_LIST);
1993 TREE_PURPOSE (t) = parm;
1994 TREE_VALUE (t) = value;
1998 /* Similar, but build on the temp_decl_obstack. */
2001 build_decl_list (parm, value)
2005 register struct obstack *ambient_obstack = current_obstack;
2006 current_obstack = &temp_decl_obstack;
2007 node = build_tree_list (parm, value);
2008 current_obstack = ambient_obstack;
2012 /* Similar, but build on the expression_obstack. */
2015 build_expr_list (parm, value)
2019 register struct obstack *ambient_obstack = current_obstack;
2020 current_obstack = expression_obstack;
2021 node = build_tree_list (parm, value);
2022 current_obstack = ambient_obstack;
2026 /* Return a newly created TREE_LIST node whose
2027 purpose and value fields are PARM and VALUE
2028 and whose TREE_CHAIN is CHAIN. */
2031 tree_cons (purpose, value, chain)
2032 tree purpose, value, chain;
2035 register tree node = make_node (TREE_LIST);
2040 node = ggc_alloc_tree (sizeof (struct tree_list));
2043 node = (tree) obstack_alloc (current_obstack, sizeof (struct tree_list));
2044 bzero (node, sizeof (struct tree_common));
2047 #ifdef GATHER_STATISTICS
2048 tree_node_counts[(int)x_kind]++;
2049 tree_node_sizes[(int)x_kind] += sizeof (struct tree_list);
2053 TREE_SET_CODE (node, TREE_LIST);
2054 if (current_obstack == &permanent_obstack)
2055 TREE_PERMANENT (node) = 1;
2058 TREE_CHAIN (node) = chain;
2059 TREE_PURPOSE (node) = purpose;
2060 TREE_VALUE (node) = value;
2064 /* Similar, but build on the temp_decl_obstack. */
2067 decl_tree_cons (purpose, value, chain)
2068 tree purpose, value, chain;
2071 register struct obstack *ambient_obstack = current_obstack;
2072 current_obstack = &temp_decl_obstack;
2073 node = tree_cons (purpose, value, chain);
2074 current_obstack = ambient_obstack;
2078 /* Similar, but build on the expression_obstack. */
2081 expr_tree_cons (purpose, value, chain)
2082 tree purpose, value, chain;
2085 register struct obstack *ambient_obstack = current_obstack;
2086 current_obstack = expression_obstack;
2087 node = tree_cons (purpose, value, chain);
2088 current_obstack = ambient_obstack;
2092 /* Same as `tree_cons' but make a permanent object. */
2095 perm_tree_cons (purpose, value, chain)
2096 tree purpose, value, chain;
2099 register struct obstack *ambient_obstack = current_obstack;
2100 current_obstack = &permanent_obstack;
2102 node = tree_cons (purpose, value, chain);
2103 current_obstack = ambient_obstack;
2107 /* Same as `tree_cons', but make this node temporary, regardless. */
2110 temp_tree_cons (purpose, value, chain)
2111 tree purpose, value, chain;
2114 register struct obstack *ambient_obstack = current_obstack;
2115 current_obstack = &temporary_obstack;
2117 node = tree_cons (purpose, value, chain);
2118 current_obstack = ambient_obstack;
2122 /* Same as `tree_cons', but save this node if the function's RTL is saved. */
2125 saveable_tree_cons (purpose, value, chain)
2126 tree purpose, value, chain;
2129 register struct obstack *ambient_obstack = current_obstack;
2130 current_obstack = saveable_obstack;
2132 node = tree_cons (purpose, value, chain);
2133 current_obstack = ambient_obstack;
2137 /* Return the size nominally occupied by an object of type TYPE
2138 when it resides in memory. The value is measured in units of bytes,
2139 and its data type is that normally used for type sizes
2140 (which is the first type created by make_signed_type or
2141 make_unsigned_type). */
2144 size_in_bytes (type)
2149 if (type == error_mark_node)
2150 return integer_zero_node;
2152 type = TYPE_MAIN_VARIANT (type);
2153 t = TYPE_SIZE_UNIT (type);
2156 incomplete_type_error (NULL_TREE, type);
2157 return integer_zero_node;
2159 if (TREE_CODE (t) == INTEGER_CST)
2160 force_fit_type (t, 0);
2165 /* Return the size of TYPE (in bytes) as a wide integer
2166 or return -1 if the size can vary or is larger than an integer. */
2169 int_size_in_bytes (type)
2174 if (type == error_mark_node)
2177 type = TYPE_MAIN_VARIANT (type);
2178 t = TYPE_SIZE_UNIT (type);
2180 || TREE_CODE (t) != INTEGER_CST
2181 || TREE_INT_CST_HIGH (t) != 0)
2184 return TREE_INT_CST_LOW (t);
2187 /* Return, as a tree node, the number of elements for TYPE (which is an
2188 ARRAY_TYPE) minus one. This counts only elements of the top array.
2190 Don't let any SAVE_EXPRs escape; if we are called as part of a cleanup
2191 action, they would get unsaved. */
2194 array_type_nelts (type)
2197 tree index_type, min, max;
2199 /* If they did it with unspecified bounds, then we should have already
2200 given an error about it before we got here. */
2201 if (! TYPE_DOMAIN (type))
2202 return error_mark_node;
2204 index_type = TYPE_DOMAIN (type);
2205 min = TYPE_MIN_VALUE (index_type);
2206 max = TYPE_MAX_VALUE (index_type);
2208 if (! TREE_CONSTANT (min))
2211 if (TREE_CODE (min) == SAVE_EXPR && SAVE_EXPR_RTL (min))
2212 min = build (RTL_EXPR, TREE_TYPE (TYPE_MIN_VALUE (index_type)), 0,
2213 SAVE_EXPR_RTL (min));
2215 min = TYPE_MIN_VALUE (index_type);
2218 if (! TREE_CONSTANT (max))
2221 if (TREE_CODE (max) == SAVE_EXPR && SAVE_EXPR_RTL (max))
2222 max = build (RTL_EXPR, TREE_TYPE (TYPE_MAX_VALUE (index_type)), 0,
2223 SAVE_EXPR_RTL (max));
2225 max = TYPE_MAX_VALUE (index_type);
2228 return (integer_zerop (min)
2230 : fold (build (MINUS_EXPR, TREE_TYPE (max), max, min)));
2233 /* Return nonzero if arg is static -- a reference to an object in
2234 static storage. This is not the same as the C meaning of `static'. */
2240 switch (TREE_CODE (arg))
2243 /* Nested functions aren't static, since taking their address
2244 involves a trampoline. */
2245 return (decl_function_context (arg) == 0 || DECL_NO_STATIC_CHAIN (arg))
2246 && ! DECL_NON_ADDR_CONST_P (arg);
2249 return (TREE_STATIC (arg) || DECL_EXTERNAL (arg))
2250 && ! DECL_NON_ADDR_CONST_P (arg);
2253 return TREE_STATIC (arg);
2258 /* If we are referencing a bitfield, we can't evaluate an
2259 ADDR_EXPR at compile time and so it isn't a constant. */
2261 return (! DECL_BIT_FIELD (TREE_OPERAND (arg, 1))
2262 && staticp (TREE_OPERAND (arg, 0)));
2268 /* This case is technically correct, but results in setting
2269 TREE_CONSTANT on ADDR_EXPRs that cannot be evaluated at
2272 return TREE_CONSTANT (TREE_OPERAND (arg, 0));
2276 if (TREE_CODE (TYPE_SIZE (TREE_TYPE (arg))) == INTEGER_CST
2277 && TREE_CODE (TREE_OPERAND (arg, 1)) == INTEGER_CST)
2278 return staticp (TREE_OPERAND (arg, 0));
2285 /* Wrap a SAVE_EXPR around EXPR, if appropriate.
2286 Do this to any expression which may be used in more than one place,
2287 but must be evaluated only once.
2289 Normally, expand_expr would reevaluate the expression each time.
2290 Calling save_expr produces something that is evaluated and recorded
2291 the first time expand_expr is called on it. Subsequent calls to
2292 expand_expr just reuse the recorded value.
2294 The call to expand_expr that generates code that actually computes
2295 the value is the first call *at compile time*. Subsequent calls
2296 *at compile time* generate code to use the saved value.
2297 This produces correct result provided that *at run time* control
2298 always flows through the insns made by the first expand_expr
2299 before reaching the other places where the save_expr was evaluated.
2300 You, the caller of save_expr, must make sure this is so.
2302 Constants, and certain read-only nodes, are returned with no
2303 SAVE_EXPR because that is safe. Expressions containing placeholders
2304 are not touched; see tree.def for an explanation of what these
2311 register tree t = fold (expr);
2313 /* We don't care about whether this can be used as an lvalue in this
2315 while (TREE_CODE (t) == NON_LVALUE_EXPR)
2316 t = TREE_OPERAND (t, 0);
2318 /* If the tree evaluates to a constant, then we don't want to hide that
2319 fact (i.e. this allows further folding, and direct checks for constants).
2320 However, a read-only object that has side effects cannot be bypassed.
2321 Since it is no problem to reevaluate literals, we just return the
2324 if (TREE_CONSTANT (t) || (TREE_READONLY (t) && ! TREE_SIDE_EFFECTS (t))
2325 || TREE_CODE (t) == SAVE_EXPR || TREE_CODE (t) == ERROR_MARK)
2328 /* If T contains a PLACEHOLDER_EXPR, we must evaluate it each time, since
2329 it means that the size or offset of some field of an object depends on
2330 the value within another field.
2332 Note that it must not be the case that T contains both a PLACEHOLDER_EXPR
2333 and some variable since it would then need to be both evaluated once and
2334 evaluated more than once. Front-ends must assure this case cannot
2335 happen by surrounding any such subexpressions in their own SAVE_EXPR
2336 and forcing evaluation at the proper time. */
2337 if (contains_placeholder_p (t))
2340 t = build (SAVE_EXPR, TREE_TYPE (expr), t, current_function_decl, NULL_TREE);
2342 /* This expression might be placed ahead of a jump to ensure that the
2343 value was computed on both sides of the jump. So make sure it isn't
2344 eliminated as dead. */
2345 TREE_SIDE_EFFECTS (t) = 1;
2349 /* Arrange for an expression to be expanded multiple independent
2350 times. This is useful for cleanup actions, as the backend can
2351 expand them multiple times in different places. */
2359 /* If this is already protected, no sense in protecting it again. */
2360 if (TREE_CODE (expr) == UNSAVE_EXPR)
2363 t = build1 (UNSAVE_EXPR, TREE_TYPE (expr), expr);
2364 TREE_SIDE_EFFECTS (t) = TREE_SIDE_EFFECTS (expr);
2368 /* Returns the index of the first non-tree operand for CODE, or the number
2369 of operands if all are trees. */
2373 enum tree_code code;
2379 case GOTO_SUBROUTINE_EXPR:
2384 case WITH_CLEANUP_EXPR:
2385 /* Should be defined to be 2. */
2387 case METHOD_CALL_EXPR:
2390 return tree_code_length [(int) code];
2394 /* Modify a tree in place so that all the evaluate only once things
2395 are cleared out. Return the EXPR given.
2397 LANG_UNSAVE_EXPR_NOW, if set, is a pointer to a function to handle
2398 language specific nodes.
2402 unsave_expr_now (expr)
2405 enum tree_code code;
2409 if (expr == NULL_TREE)
2412 code = TREE_CODE (expr);
2413 first_rtl = first_rtl_op (code);
2417 SAVE_EXPR_RTL (expr) = 0;
2421 TREE_OPERAND (expr, 1) = TREE_OPERAND (expr, 3);
2422 TREE_OPERAND (expr, 3) = NULL_TREE;
2426 /* I don't yet know how to emit a sequence multiple times. */
2427 if (RTL_EXPR_SEQUENCE (expr) != 0)
2432 CALL_EXPR_RTL (expr) = 0;
2433 if (TREE_OPERAND (expr, 1)
2434 && TREE_CODE (TREE_OPERAND (expr, 1)) == TREE_LIST)
2436 tree exp = TREE_OPERAND (expr, 1);
2439 unsave_expr_now (TREE_VALUE (exp));
2440 exp = TREE_CHAIN (exp);
2446 if (lang_unsave_expr_now)
2447 (*lang_unsave_expr_now) (expr);
2451 switch (TREE_CODE_CLASS (code))
2453 case 'c': /* a constant */
2454 case 't': /* a type node */
2455 case 'x': /* something random, like an identifier or an ERROR_MARK. */
2456 case 'd': /* A decl node */
2457 case 'b': /* A block node */
2460 case 'e': /* an expression */
2461 case 'r': /* a reference */
2462 case 's': /* an expression with side effects */
2463 case '<': /* a comparison expression */
2464 case '2': /* a binary arithmetic expression */
2465 case '1': /* a unary arithmetic expression */
2466 for (i = first_rtl - 1; i >= 0; i--)
2467 unsave_expr_now (TREE_OPERAND (expr, i));
2475 /* Return 1 if EXP contains a PLACEHOLDER_EXPR; i.e., if it represents a size
2476 or offset that depends on a field within a record. */
2479 contains_placeholder_p (exp)
2482 register enum tree_code code = TREE_CODE (exp);
2485 /* If we have a WITH_RECORD_EXPR, it "cancels" any PLACEHOLDER_EXPR
2486 in it since it is supplying a value for it. */
2487 if (code == WITH_RECORD_EXPR)
2489 else if (code == PLACEHOLDER_EXPR)
2492 switch (TREE_CODE_CLASS (code))
2495 /* Don't look at any PLACEHOLDER_EXPRs that might be in index or bit
2496 position computations since they will be converted into a
2497 WITH_RECORD_EXPR involving the reference, which will assume
2498 here will be valid. */
2499 return contains_placeholder_p (TREE_OPERAND (exp, 0));
2502 if (code == TREE_LIST)
2503 return (contains_placeholder_p (TREE_VALUE (exp))
2504 || (TREE_CHAIN (exp) != 0
2505 && contains_placeholder_p (TREE_CHAIN (exp))));
2514 /* Ignoring the first operand isn't quite right, but works best. */
2515 return contains_placeholder_p (TREE_OPERAND (exp, 1));
2522 return (contains_placeholder_p (TREE_OPERAND (exp, 0))
2523 || contains_placeholder_p (TREE_OPERAND (exp, 1))
2524 || contains_placeholder_p (TREE_OPERAND (exp, 2)));
2527 /* If we already know this doesn't have a placeholder, don't
2529 if (SAVE_EXPR_NOPLACEHOLDER (exp) || SAVE_EXPR_RTL (exp) != 0)
2532 SAVE_EXPR_NOPLACEHOLDER (exp) = 1;
2533 result = contains_placeholder_p (TREE_OPERAND (exp, 0));
2535 SAVE_EXPR_NOPLACEHOLDER (exp) = 0;
2540 return (TREE_OPERAND (exp, 1) != 0
2541 && contains_placeholder_p (TREE_OPERAND (exp, 1)));
2547 switch (tree_code_length[(int) code])
2550 return contains_placeholder_p (TREE_OPERAND (exp, 0));
2552 return (contains_placeholder_p (TREE_OPERAND (exp, 0))
2553 || contains_placeholder_p (TREE_OPERAND (exp, 1)));
2564 /* Return 1 if EXP contains any expressions that produce cleanups for an
2565 outer scope to deal with. Used by fold. */
2573 if (! TREE_SIDE_EFFECTS (exp))
2576 switch (TREE_CODE (exp))
2579 case GOTO_SUBROUTINE_EXPR:
2580 case WITH_CLEANUP_EXPR:
2583 case CLEANUP_POINT_EXPR:
2587 for (exp = TREE_OPERAND (exp, 1); exp; exp = TREE_CHAIN (exp))
2589 cmp = has_cleanups (TREE_VALUE (exp));
2599 /* This general rule works for most tree codes. All exceptions should be
2600 handled above. If this is a language-specific tree code, we can't
2601 trust what might be in the operand, so say we don't know
2603 if ((int) TREE_CODE (exp) >= (int) LAST_AND_UNUSED_TREE_CODE)
2606 nops = first_rtl_op (TREE_CODE (exp));
2607 for (i = 0; i < nops; i++)
2608 if (TREE_OPERAND (exp, i) != 0)
2610 int type = TREE_CODE_CLASS (TREE_CODE (TREE_OPERAND (exp, i)));
2611 if (type == 'e' || type == '<' || type == '1' || type == '2'
2612 || type == 'r' || type == 's')
2614 cmp = has_cleanups (TREE_OPERAND (exp, i));
2623 /* Given a tree EXP, a FIELD_DECL F, and a replacement value R,
2624 return a tree with all occurrences of references to F in a
2625 PLACEHOLDER_EXPR replaced by R. Note that we assume here that EXP
2626 contains only arithmetic expressions or a CALL_EXPR with a
2627 PLACEHOLDER_EXPR occurring only in its arglist. */
2630 substitute_in_expr (exp, f, r)
2635 enum tree_code code = TREE_CODE (exp);
2640 switch (TREE_CODE_CLASS (code))
2647 if (code == PLACEHOLDER_EXPR)
2649 else if (code == TREE_LIST)
2651 op0 = (TREE_CHAIN (exp) == 0
2652 ? 0 : substitute_in_expr (TREE_CHAIN (exp), f, r));
2653 op1 = substitute_in_expr (TREE_VALUE (exp), f, r);
2654 if (op0 == TREE_CHAIN (exp) && op1 == TREE_VALUE (exp))
2657 return tree_cons (TREE_PURPOSE (exp), op1, op0);
2666 switch (tree_code_length[(int) code])
2669 op0 = substitute_in_expr (TREE_OPERAND (exp, 0), f, r);
2670 if (op0 == TREE_OPERAND (exp, 0))
2673 new = fold (build1 (code, TREE_TYPE (exp), op0));
2677 /* An RTL_EXPR cannot contain a PLACEHOLDER_EXPR; a CONSTRUCTOR
2678 could, but we don't support it. */
2679 if (code == RTL_EXPR)
2681 else if (code == CONSTRUCTOR)
2684 op0 = substitute_in_expr (TREE_OPERAND (exp, 0), f, r);
2685 op1 = substitute_in_expr (TREE_OPERAND (exp, 1), f, r);
2686 if (op0 == TREE_OPERAND (exp, 0) && op1 == TREE_OPERAND (exp, 1))
2689 new = fold (build (code, TREE_TYPE (exp), op0, op1));
2693 /* It cannot be that anything inside a SAVE_EXPR contains a
2694 PLACEHOLDER_EXPR. */
2695 if (code == SAVE_EXPR)
2698 else if (code == CALL_EXPR)
2700 op1 = substitute_in_expr (TREE_OPERAND (exp, 1), f, r);
2701 if (op1 == TREE_OPERAND (exp, 1))
2704 return build (code, TREE_TYPE (exp),
2705 TREE_OPERAND (exp, 0), op1, NULL_TREE);
2708 else if (code != COND_EXPR)
2711 op0 = substitute_in_expr (TREE_OPERAND (exp, 0), f, r);
2712 op1 = substitute_in_expr (TREE_OPERAND (exp, 1), f, r);
2713 op2 = substitute_in_expr (TREE_OPERAND (exp, 2), f, r);
2714 if (op0 == TREE_OPERAND (exp, 0) && op1 == TREE_OPERAND (exp, 1)
2715 && op2 == TREE_OPERAND (exp, 2))
2718 new = fold (build (code, TREE_TYPE (exp), op0, op1, op2));
2731 /* If this expression is getting a value from a PLACEHOLDER_EXPR
2732 and it is the right field, replace it with R. */
2733 for (inner = TREE_OPERAND (exp, 0);
2734 TREE_CODE_CLASS (TREE_CODE (inner)) == 'r';
2735 inner = TREE_OPERAND (inner, 0))
2737 if (TREE_CODE (inner) == PLACEHOLDER_EXPR
2738 && TREE_OPERAND (exp, 1) == f)
2741 /* If this expression hasn't been completed let, leave it
2743 if (TREE_CODE (inner) == PLACEHOLDER_EXPR
2744 && TREE_TYPE (inner) == 0)
2747 op0 = substitute_in_expr (TREE_OPERAND (exp, 0), f, r);
2748 if (op0 == TREE_OPERAND (exp, 0))
2751 new = fold (build (code, TREE_TYPE (exp), op0,
2752 TREE_OPERAND (exp, 1)));
2756 op0 = substitute_in_expr (TREE_OPERAND (exp, 0), f, r);
2757 op1 = substitute_in_expr (TREE_OPERAND (exp, 1), f, r);
2758 op2 = substitute_in_expr (TREE_OPERAND (exp, 2), f, r);
2759 if (op0 == TREE_OPERAND (exp, 0) && op1 == TREE_OPERAND (exp, 1)
2760 && op2 == TREE_OPERAND (exp, 2))
2763 new = fold (build (code, TREE_TYPE (exp), op0, op1, op2));
2768 op0 = substitute_in_expr (TREE_OPERAND (exp, 0), f, r);
2769 if (op0 == TREE_OPERAND (exp, 0))
2772 new = fold (build1 (code, TREE_TYPE (exp), op0));
2784 TREE_READONLY (new) = TREE_READONLY (exp);
2788 /* Stabilize a reference so that we can use it any number of times
2789 without causing its operands to be evaluated more than once.
2790 Returns the stabilized reference. This works by means of save_expr,
2791 so see the caveats in the comments about save_expr.
2793 Also allows conversion expressions whose operands are references.
2794 Any other kind of expression is returned unchanged. */
2797 stabilize_reference (ref)
2800 register tree result;
2801 register enum tree_code code = TREE_CODE (ref);
2808 /* No action is needed in this case. */
2814 case FIX_TRUNC_EXPR:
2815 case FIX_FLOOR_EXPR:
2816 case FIX_ROUND_EXPR:
2818 result = build_nt (code, stabilize_reference (TREE_OPERAND (ref, 0)));
2822 result = build_nt (INDIRECT_REF,
2823 stabilize_reference_1 (TREE_OPERAND (ref, 0)));
2827 result = build_nt (COMPONENT_REF,
2828 stabilize_reference (TREE_OPERAND (ref, 0)),
2829 TREE_OPERAND (ref, 1));
2833 result = build_nt (BIT_FIELD_REF,
2834 stabilize_reference (TREE_OPERAND (ref, 0)),
2835 stabilize_reference_1 (TREE_OPERAND (ref, 1)),
2836 stabilize_reference_1 (TREE_OPERAND (ref, 2)));
2840 result = build_nt (ARRAY_REF,
2841 stabilize_reference (TREE_OPERAND (ref, 0)),
2842 stabilize_reference_1 (TREE_OPERAND (ref, 1)));
2846 /* We cannot wrap the first expression in a SAVE_EXPR, as then
2847 it wouldn't be ignored. This matters when dealing with
2849 return stabilize_reference_1 (ref);
2852 result = build1 (INDIRECT_REF, TREE_TYPE (ref),
2853 save_expr (build1 (ADDR_EXPR,
2854 build_pointer_type (TREE_TYPE (ref)),
2859 /* If arg isn't a kind of lvalue we recognize, make no change.
2860 Caller should recognize the error for an invalid lvalue. */
2865 return error_mark_node;
2868 TREE_TYPE (result) = TREE_TYPE (ref);
2869 TREE_READONLY (result) = TREE_READONLY (ref);
2870 TREE_SIDE_EFFECTS (result) = TREE_SIDE_EFFECTS (ref);
2871 TREE_THIS_VOLATILE (result) = TREE_THIS_VOLATILE (ref);
2872 TREE_RAISES (result) = TREE_RAISES (ref);
2877 /* Subroutine of stabilize_reference; this is called for subtrees of
2878 references. Any expression with side-effects must be put in a SAVE_EXPR
2879 to ensure that it is only evaluated once.
2881 We don't put SAVE_EXPR nodes around everything, because assigning very
2882 simple expressions to temporaries causes us to miss good opportunities
2883 for optimizations. Among other things, the opportunity to fold in the
2884 addition of a constant into an addressing mode often gets lost, e.g.
2885 "y[i+1] += x;". In general, we take the approach that we should not make
2886 an assignment unless we are forced into it - i.e., that any non-side effect
2887 operator should be allowed, and that cse should take care of coalescing
2888 multiple utterances of the same expression should that prove fruitful. */
2891 stabilize_reference_1 (e)
2894 register tree result;
2895 register enum tree_code code = TREE_CODE (e);
2897 /* We cannot ignore const expressions because it might be a reference
2898 to a const array but whose index contains side-effects. But we can
2899 ignore things that are actual constant or that already have been
2900 handled by this function. */
2902 if (TREE_CONSTANT (e) || code == SAVE_EXPR)
2905 switch (TREE_CODE_CLASS (code))
2915 /* If the expression has side-effects, then encase it in a SAVE_EXPR
2916 so that it will only be evaluated once. */
2917 /* The reference (r) and comparison (<) classes could be handled as
2918 below, but it is generally faster to only evaluate them once. */
2919 if (TREE_SIDE_EFFECTS (e))
2920 return save_expr (e);
2924 /* Constants need no processing. In fact, we should never reach
2929 /* Division is slow and tends to be compiled with jumps,
2930 especially the division by powers of 2 that is often
2931 found inside of an array reference. So do it just once. */
2932 if (code == TRUNC_DIV_EXPR || code == TRUNC_MOD_EXPR
2933 || code == FLOOR_DIV_EXPR || code == FLOOR_MOD_EXPR
2934 || code == CEIL_DIV_EXPR || code == CEIL_MOD_EXPR
2935 || code == ROUND_DIV_EXPR || code == ROUND_MOD_EXPR)
2936 return save_expr (e);
2937 /* Recursively stabilize each operand. */
2938 result = build_nt (code, stabilize_reference_1 (TREE_OPERAND (e, 0)),
2939 stabilize_reference_1 (TREE_OPERAND (e, 1)));
2943 /* Recursively stabilize each operand. */
2944 result = build_nt (code, stabilize_reference_1 (TREE_OPERAND (e, 0)));
2951 TREE_TYPE (result) = TREE_TYPE (e);
2952 TREE_READONLY (result) = TREE_READONLY (e);
2953 TREE_SIDE_EFFECTS (result) = TREE_SIDE_EFFECTS (e);
2954 TREE_THIS_VOLATILE (result) = TREE_THIS_VOLATILE (e);
2955 TREE_RAISES (result) = TREE_RAISES (e);
2960 /* Low-level constructors for expressions. */
2962 /* Build an expression of code CODE, data type TYPE,
2963 and operands as specified by the arguments ARG1 and following arguments.
2964 Expressions and reference nodes can be created this way.
2965 Constants, decls, types and misc nodes cannot be. */
2968 build VPROTO((enum tree_code code, tree tt, ...))
2970 #ifndef ANSI_PROTOTYPES
2971 enum tree_code code;
2976 register int length;
2981 #ifndef ANSI_PROTOTYPES
2982 code = va_arg (p, enum tree_code);
2983 tt = va_arg (p, tree);
2986 t = make_node (code);
2987 length = tree_code_length[(int) code];
2992 /* This is equivalent to the loop below, but faster. */
2993 register tree arg0 = va_arg (p, tree);
2994 register tree arg1 = va_arg (p, tree);
2995 TREE_OPERAND (t, 0) = arg0;
2996 TREE_OPERAND (t, 1) = arg1;
2997 if ((arg0 && TREE_SIDE_EFFECTS (arg0))
2998 || (arg1 && TREE_SIDE_EFFECTS (arg1)))
2999 TREE_SIDE_EFFECTS (t) = 1;
3001 = (arg0 && TREE_RAISES (arg0)) || (arg1 && TREE_RAISES (arg1));
3003 else if (length == 1)
3005 register tree arg0 = va_arg (p, tree);
3007 /* Call build1 for this! */
3008 if (TREE_CODE_CLASS (code) != 's')
3010 TREE_OPERAND (t, 0) = arg0;
3011 if (arg0 && TREE_SIDE_EFFECTS (arg0))
3012 TREE_SIDE_EFFECTS (t) = 1;
3013 TREE_RAISES (t) = (arg0 && TREE_RAISES (arg0));
3017 for (i = 0; i < length; i++)
3019 register tree operand = va_arg (p, tree);
3020 TREE_OPERAND (t, i) = operand;
3023 if (TREE_SIDE_EFFECTS (operand))
3024 TREE_SIDE_EFFECTS (t) = 1;
3025 if (TREE_RAISES (operand))
3026 TREE_RAISES (t) = 1;
3034 /* Same as above, but only builds for unary operators.
3035 Saves lions share of calls to `build'; cuts down use
3036 of varargs, which is expensive for RISC machines. */
3039 build1 (code, type, node)
3040 enum tree_code code;
3044 register struct obstack *obstack = expression_obstack;
3045 register int length;
3046 #ifdef GATHER_STATISTICS
3047 register tree_node_kind kind;
3051 #ifdef GATHER_STATISTICS
3052 if (TREE_CODE_CLASS (code) == 'r')
3058 length = sizeof (struct tree_exp);
3061 t = ggc_alloc_tree (length);
3063 t = (tree) obstack_alloc (obstack, length);
3064 bzero ((PTR) t, length);
3066 #ifdef GATHER_STATISTICS
3067 tree_node_counts[(int)kind]++;
3068 tree_node_sizes[(int)kind] += length;
3071 TREE_TYPE (t) = type;
3072 TREE_SET_CODE (t, code);
3074 if (obstack == &permanent_obstack)
3075 TREE_PERMANENT (t) = 1;
3077 TREE_OPERAND (t, 0) = node;
3080 if (TREE_SIDE_EFFECTS (node))
3081 TREE_SIDE_EFFECTS (t) = 1;
3082 if (TREE_RAISES (node))
3083 TREE_RAISES (t) = 1;
3089 /* Similar except don't specify the TREE_TYPE
3090 and leave the TREE_SIDE_EFFECTS as 0.
3091 It is permissible for arguments to be null,
3092 or even garbage if their values do not matter. */
3095 build_nt VPROTO((enum tree_code code, ...))
3097 #ifndef ANSI_PROTOTYPES
3098 enum tree_code code;
3102 register int length;
3107 #ifndef ANSI_PROTOTYPES
3108 code = va_arg (p, enum tree_code);
3111 t = make_node (code);
3112 length = tree_code_length[(int) code];
3114 for (i = 0; i < length; i++)
3115 TREE_OPERAND (t, i) = va_arg (p, tree);
3121 /* Similar to `build_nt', except we build
3122 on the temp_decl_obstack, regardless. */
3125 build_parse_node VPROTO((enum tree_code code, ...))
3127 #ifndef ANSI_PROTOTYPES
3128 enum tree_code code;
3130 register struct obstack *ambient_obstack = expression_obstack;
3133 register int length;
3138 #ifndef ANSI_PROTOTYPES
3139 code = va_arg (p, enum tree_code);
3142 expression_obstack = &temp_decl_obstack;
3144 t = make_node (code);
3145 length = tree_code_length[(int) code];
3147 for (i = 0; i < length; i++)
3148 TREE_OPERAND (t, i) = va_arg (p, tree);
3151 expression_obstack = ambient_obstack;
3156 /* Commented out because this wants to be done very
3157 differently. See cp-lex.c. */
3159 build_op_identifier (op1, op2)
3162 register tree t = make_node (OP_IDENTIFIER);
3163 TREE_PURPOSE (t) = op1;
3164 TREE_VALUE (t) = op2;
3169 /* Create a DECL_... node of code CODE, name NAME and data type TYPE.
3170 We do NOT enter this node in any sort of symbol table.
3172 layout_decl is used to set up the decl's storage layout.
3173 Other slots are initialized to 0 or null pointers. */
3176 build_decl (code, name, type)
3177 enum tree_code code;
3182 t = make_node (code);
3184 /* if (type == error_mark_node)
3185 type = integer_type_node; */
3186 /* That is not done, deliberately, so that having error_mark_node
3187 as the type can suppress useless errors in the use of this variable. */
3189 DECL_NAME (t) = name;
3190 DECL_ASSEMBLER_NAME (t) = name;
3191 TREE_TYPE (t) = type;
3193 if (code == VAR_DECL || code == PARM_DECL || code == RESULT_DECL)
3195 else if (code == FUNCTION_DECL)
3196 DECL_MODE (t) = FUNCTION_MODE;
3201 /* BLOCK nodes are used to represent the structure of binding contours
3202 and declarations, once those contours have been exited and their contents
3203 compiled. This information is used for outputting debugging info. */
3206 build_block (vars, tags, subblocks, supercontext, chain)
3207 tree vars, tags, subblocks, supercontext, chain;
3209 register tree block = make_node (BLOCK);
3210 BLOCK_VARS (block) = vars;
3211 BLOCK_TYPE_TAGS (block) = tags;
3212 BLOCK_SUBBLOCKS (block) = subblocks;
3213 BLOCK_SUPERCONTEXT (block) = supercontext;
3214 BLOCK_CHAIN (block) = chain;
3218 /* EXPR_WITH_FILE_LOCATION are used to keep track of the exact
3219 location where an expression or an identifier were encountered. It
3220 is necessary for languages where the frontend parser will handle
3221 recursively more than one file (Java is one of them). */
3224 build_expr_wfl (node, file, line, col)
3229 static const char *last_file = 0;
3230 static tree last_filenode = NULL_TREE;
3231 register tree wfl = make_node (EXPR_WITH_FILE_LOCATION);
3233 EXPR_WFL_NODE (wfl) = node;
3234 EXPR_WFL_SET_LINECOL (wfl, line, col);
3235 if (file != last_file)
3238 last_filenode = file ? get_identifier (file) : NULL_TREE;
3240 EXPR_WFL_FILENAME_NODE (wfl) = last_filenode;
3243 TREE_SIDE_EFFECTS (wfl) = TREE_SIDE_EFFECTS (node);
3244 TREE_TYPE (wfl) = TREE_TYPE (node);
3249 /* Return a declaration like DDECL except that its DECL_MACHINE_ATTRIBUTE
3253 build_decl_attribute_variant (ddecl, attribute)
3254 tree ddecl, attribute;
3256 DECL_MACHINE_ATTRIBUTES (ddecl) = attribute;
3260 /* Return a type like TTYPE except that its TYPE_ATTRIBUTE
3263 Record such modified types already made so we don't make duplicates. */
3266 build_type_attribute_variant (ttype, attribute)
3267 tree ttype, attribute;
3269 if ( ! attribute_list_equal (TYPE_ATTRIBUTES (ttype), attribute))
3271 register int hashcode;
3272 register struct obstack *ambient_obstack = current_obstack;
3275 if (ambient_obstack != &permanent_obstack)
3276 current_obstack = TYPE_OBSTACK (ttype);
3278 ntype = copy_node (ttype);
3280 TYPE_POINTER_TO (ntype) = 0;
3281 TYPE_REFERENCE_TO (ntype) = 0;
3282 TYPE_ATTRIBUTES (ntype) = attribute;
3284 /* Create a new main variant of TYPE. */
3285 TYPE_MAIN_VARIANT (ntype) = ntype;
3286 TYPE_NEXT_VARIANT (ntype) = 0;
3287 set_type_quals (ntype, TYPE_UNQUALIFIED);
3289 hashcode = TYPE_HASH (TREE_CODE (ntype))
3290 + TYPE_HASH (TREE_TYPE (ntype))
3291 + attribute_hash_list (attribute);
3293 switch (TREE_CODE (ntype))
3296 hashcode += TYPE_HASH (TYPE_ARG_TYPES (ntype));
3299 hashcode += TYPE_HASH (TYPE_DOMAIN (ntype));
3302 hashcode += TYPE_HASH (TYPE_MAX_VALUE (ntype));
3305 hashcode += TYPE_HASH (TYPE_PRECISION (ntype));
3311 ntype = type_hash_canon (hashcode, ntype);
3312 ttype = build_qualified_type (ntype, TYPE_QUALS (ttype));
3314 /* We must restore the current obstack after the type_hash_canon call,
3315 because type_hash_canon calls type_hash_add for permanent types, and
3316 then type_hash_add calls oballoc expecting to get something permanent
3318 current_obstack = ambient_obstack;
3324 /* Return a 1 if ATTR_NAME and ATTR_ARGS is valid for either declaration DECL
3325 or type TYPE and 0 otherwise. Validity is determined the configuration
3326 macros VALID_MACHINE_DECL_ATTRIBUTE and VALID_MACHINE_TYPE_ATTRIBUTE. */
3329 valid_machine_attribute (attr_name, attr_args, decl, type)
3331 tree attr_args ATTRIBUTE_UNUSED;
3332 tree decl ATTRIBUTE_UNUSED;
3333 tree type ATTRIBUTE_UNUSED;
3336 #ifdef VALID_MACHINE_DECL_ATTRIBUTE
3337 tree decl_attr_list = decl != 0 ? DECL_MACHINE_ATTRIBUTES (decl) : 0;
3339 #ifdef VALID_MACHINE_TYPE_ATTRIBUTE
3340 tree type_attr_list = TYPE_ATTRIBUTES (type);
3343 if (TREE_CODE (attr_name) != IDENTIFIER_NODE)
3346 #ifdef VALID_MACHINE_DECL_ATTRIBUTE
3348 && VALID_MACHINE_DECL_ATTRIBUTE (decl, decl_attr_list, attr_name, attr_args))
3350 tree attr = lookup_attribute (IDENTIFIER_POINTER (attr_name),
3353 if (attr != NULL_TREE)
3355 /* Override existing arguments. Declarations are unique so we can
3356 modify this in place. */
3357 TREE_VALUE (attr) = attr_args;
3361 decl_attr_list = tree_cons (attr_name, attr_args, decl_attr_list);
3362 decl = build_decl_attribute_variant (decl, decl_attr_list);
3369 #ifdef VALID_MACHINE_TYPE_ATTRIBUTE
3371 /* Don't apply the attribute to both the decl and the type. */;
3372 else if (VALID_MACHINE_TYPE_ATTRIBUTE (type, type_attr_list, attr_name,
3375 tree attr = lookup_attribute (IDENTIFIER_POINTER (attr_name),
3378 if (attr != NULL_TREE)
3380 /* Override existing arguments.
3381 ??? This currently works since attribute arguments are not
3382 included in `attribute_hash_list'. Something more complicated
3383 may be needed in the future. */
3384 TREE_VALUE (attr) = attr_args;
3388 /* If this is part of a declaration, create a type variant,
3389 otherwise, this is part of a type definition, so add it
3390 to the base type. */
3391 type_attr_list = tree_cons (attr_name, attr_args, type_attr_list);
3393 type = build_type_attribute_variant (type, type_attr_list);
3395 TYPE_ATTRIBUTES (type) = type_attr_list;
3398 TREE_TYPE (decl) = type;
3402 /* Handle putting a type attribute on pointer-to-function-type by putting
3403 the attribute on the function type. */
3404 else if (POINTER_TYPE_P (type)
3405 && TREE_CODE (TREE_TYPE (type)) == FUNCTION_TYPE
3406 && VALID_MACHINE_TYPE_ATTRIBUTE (TREE_TYPE (type), type_attr_list,
3407 attr_name, attr_args))
3409 tree inner_type = TREE_TYPE (type);
3410 tree inner_attr_list = TYPE_ATTRIBUTES (inner_type);
3411 tree attr = lookup_attribute (IDENTIFIER_POINTER (attr_name),
3414 if (attr != NULL_TREE)
3415 TREE_VALUE (attr) = attr_args;
3418 inner_attr_list = tree_cons (attr_name, attr_args, inner_attr_list);
3419 inner_type = build_type_attribute_variant (inner_type,
3424 TREE_TYPE (decl) = build_pointer_type (inner_type);
3427 /* Clear TYPE_POINTER_TO for the old inner type, since
3428 `type' won't be pointing to it anymore. */
3429 TYPE_POINTER_TO (TREE_TYPE (type)) = NULL_TREE;
3430 TREE_TYPE (type) = inner_type;
3440 /* Return non-zero if IDENT is a valid name for attribute ATTR,
3443 We try both `text' and `__text__', ATTR may be either one. */
3444 /* ??? It might be a reasonable simplification to require ATTR to be only
3445 `text'. One might then also require attribute lists to be stored in
3446 their canonicalized form. */
3449 is_attribute_p (attr, ident)
3453 int ident_len, attr_len;
3456 if (TREE_CODE (ident) != IDENTIFIER_NODE)
3459 if (strcmp (attr, IDENTIFIER_POINTER (ident)) == 0)
3462 p = IDENTIFIER_POINTER (ident);
3463 ident_len = strlen (p);
3464 attr_len = strlen (attr);
3466 /* If ATTR is `__text__', IDENT must be `text'; and vice versa. */
3470 || attr[attr_len - 2] != '_'
3471 || attr[attr_len - 1] != '_')
3473 if (ident_len == attr_len - 4
3474 && strncmp (attr + 2, p, attr_len - 4) == 0)
3479 if (ident_len == attr_len + 4
3480 && p[0] == '_' && p[1] == '_'
3481 && p[ident_len - 2] == '_' && p[ident_len - 1] == '_'
3482 && strncmp (attr, p + 2, attr_len) == 0)
3489 /* Given an attribute name and a list of attributes, return a pointer to the
3490 attribute's list element if the attribute is part of the list, or NULL_TREE
3494 lookup_attribute (attr_name, list)
3495 const char *attr_name;
3500 for (l = list; l; l = TREE_CHAIN (l))
3502 if (TREE_CODE (TREE_PURPOSE (l)) != IDENTIFIER_NODE)
3504 if (is_attribute_p (attr_name, TREE_PURPOSE (l)))
3511 /* Return an attribute list that is the union of a1 and a2. */
3514 merge_attributes (a1, a2)
3515 register tree a1, a2;
3519 /* Either one unset? Take the set one. */
3521 if (! (attributes = a1))
3524 /* One that completely contains the other? Take it. */
3526 else if (a2 && ! attribute_list_contained (a1, a2))
3528 if (attribute_list_contained (a2, a1))
3532 /* Pick the longest list, and hang on the other list. */
3533 /* ??? For the moment we punt on the issue of attrs with args. */
3535 if (list_length (a1) < list_length (a2))
3536 attributes = a2, a2 = a1;
3538 for (; a2; a2 = TREE_CHAIN (a2))
3539 if (lookup_attribute (IDENTIFIER_POINTER (TREE_PURPOSE (a2)),
3540 attributes) == NULL_TREE)
3542 a1 = copy_node (a2);
3543 TREE_CHAIN (a1) = attributes;
3551 /* Given types T1 and T2, merge their attributes and return
3555 merge_machine_type_attributes (t1, t2)
3558 #ifdef MERGE_MACHINE_TYPE_ATTRIBUTES
3559 return MERGE_MACHINE_TYPE_ATTRIBUTES (t1, t2);
3561 return merge_attributes (TYPE_ATTRIBUTES (t1),
3562 TYPE_ATTRIBUTES (t2));
3566 /* Given decls OLDDECL and NEWDECL, merge their attributes and return
3570 merge_machine_decl_attributes (olddecl, newdecl)
3571 tree olddecl, newdecl;
3573 #ifdef MERGE_MACHINE_DECL_ATTRIBUTES
3574 return MERGE_MACHINE_DECL_ATTRIBUTES (olddecl, newdecl);
3576 return merge_attributes (DECL_MACHINE_ATTRIBUTES (olddecl),
3577 DECL_MACHINE_ATTRIBUTES (newdecl));
3581 /* Set the type qualifiers for TYPE to TYPE_QUALS, which is a bitmask
3582 of the various TYPE_QUAL values. */
3585 set_type_quals (type, type_quals)
3589 TYPE_READONLY (type) = (type_quals & TYPE_QUAL_CONST) != 0;
3590 TYPE_VOLATILE (type) = (type_quals & TYPE_QUAL_VOLATILE) != 0;
3591 TYPE_RESTRICT (type) = (type_quals & TYPE_QUAL_RESTRICT) != 0;
3594 /* Given a type node TYPE and a TYPE_QUALIFIER_SET, return a type for
3595 the same kind of data as TYPE describes. Variants point to the
3596 "main variant" (which has no qualifiers set) via TYPE_MAIN_VARIANT,
3597 and it points to a chain of other variants so that duplicate
3598 variants are never made. Only main variants should ever appear as
3599 types of expressions. */
3602 build_qualified_type (type, type_quals)
3608 /* Search the chain of variants to see if there is already one there just
3609 like the one we need to have. If so, use that existing one. We must
3610 preserve the TYPE_NAME, since there is code that depends on this. */
3612 for (t = TYPE_MAIN_VARIANT (type); t; t = TYPE_NEXT_VARIANT (t))
3613 if (TYPE_QUALS (t) == type_quals && TYPE_NAME (t) == TYPE_NAME (type))
3616 /* We need a new one. */
3617 t = build_type_copy (type);
3618 set_type_quals (t, type_quals);
3622 /* Create a new variant of TYPE, equivalent but distinct.
3623 This is so the caller can modify it. */
3626 build_type_copy (type)
3629 register tree t, m = TYPE_MAIN_VARIANT (type);
3630 register struct obstack *ambient_obstack = current_obstack;
3632 current_obstack = TYPE_OBSTACK (type);
3633 t = copy_node (type);
3634 current_obstack = ambient_obstack;
3636 TYPE_POINTER_TO (t) = 0;
3637 TYPE_REFERENCE_TO (t) = 0;
3639 /* Add this type to the chain of variants of TYPE. */
3640 TYPE_NEXT_VARIANT (t) = TYPE_NEXT_VARIANT (m);
3641 TYPE_NEXT_VARIANT (m) = t;
3646 /* Hashing of types so that we don't make duplicates.
3647 The entry point is `type_hash_canon'. */
3649 /* Compute a hash code for a list of types (chain of TREE_LIST nodes
3650 with types in the TREE_VALUE slots), by adding the hash codes
3651 of the individual types. */
3654 type_hash_list (list)
3657 register int hashcode;
3659 for (hashcode = 0, tail = list; tail; tail = TREE_CHAIN (tail))
3660 hashcode += TYPE_HASH (TREE_VALUE (tail));
3664 /* Look in the type hash table for a type isomorphic to TYPE.
3665 If one is found, return it. Otherwise return 0. */
3668 type_hash_lookup (hashcode, type)
3672 register struct type_hash *h;
3673 for (h = type_hash_table[hashcode % TYPE_HASH_SIZE]; h; h = h->next)
3674 if (h->hashcode == hashcode
3675 && TREE_CODE (h->type) == TREE_CODE (type)
3676 && TREE_TYPE (h->type) == TREE_TYPE (type)
3677 && attribute_list_equal (TYPE_ATTRIBUTES (h->type),
3678 TYPE_ATTRIBUTES (type))
3679 && (TYPE_MAX_VALUE (h->type) == TYPE_MAX_VALUE (type)
3680 || tree_int_cst_equal (TYPE_MAX_VALUE (h->type),
3681 TYPE_MAX_VALUE (type)))
3682 && (TYPE_MIN_VALUE (h->type) == TYPE_MIN_VALUE (type)
3683 || tree_int_cst_equal (TYPE_MIN_VALUE (h->type),
3684 TYPE_MIN_VALUE (type)))
3685 /* Note that TYPE_DOMAIN is TYPE_ARG_TYPES for FUNCTION_TYPE. */
3686 && (TYPE_DOMAIN (h->type) == TYPE_DOMAIN (type)
3687 || (TYPE_DOMAIN (h->type)
3688 && TREE_CODE (TYPE_DOMAIN (h->type)) == TREE_LIST
3689 && TYPE_DOMAIN (type)
3690 && TREE_CODE (TYPE_DOMAIN (type)) == TREE_LIST
3691 && type_list_equal (TYPE_DOMAIN (h->type),
3692 TYPE_DOMAIN (type)))))
3697 /* Add an entry to the type-hash-table
3698 for a type TYPE whose hash code is HASHCODE. */
3701 type_hash_add (hashcode, type)
3705 register struct type_hash *h;
3707 h = (struct type_hash *) permalloc (sizeof (struct type_hash));
3708 h->hashcode = hashcode;
3710 h->next = type_hash_table[hashcode % TYPE_HASH_SIZE];
3711 type_hash_table[hashcode % TYPE_HASH_SIZE] = h;
3714 /* Given TYPE, and HASHCODE its hash code, return the canonical
3715 object for an identical type if one already exists.
3716 Otherwise, return TYPE, and record it as the canonical object
3717 if it is a permanent object.
3719 To use this function, first create a type of the sort you want.
3720 Then compute its hash code from the fields of the type that
3721 make it different from other similar types.
3722 Then call this function and use the value.
3723 This function frees the type you pass in if it is a duplicate. */
3725 /* Set to 1 to debug without canonicalization. Never set by program. */
3726 int debug_no_type_hash = 0;
3729 type_hash_canon (hashcode, type)
3735 if (debug_no_type_hash)
3738 t1 = type_hash_lookup (hashcode, type);
3742 obstack_free (TYPE_OBSTACK (type), type);
3743 #ifdef GATHER_STATISTICS
3744 tree_node_counts[(int)t_kind]--;
3745 tree_node_sizes[(int)t_kind] -= sizeof (struct tree_type);
3750 /* If this is a permanent type, record it for later reuse. */
3751 if (TREE_PERMANENT (type))
3752 type_hash_add (hashcode, type);
3757 /* Mark ARG (which is really a struct type_hash **) for GC. */
3760 mark_type_hash (arg)
3763 struct type_hash *t = *(struct type_hash **) arg;
3767 ggc_mark_tree (t->type);
3772 /* Compute a hash code for a list of attributes (chain of TREE_LIST nodes
3773 with names in the TREE_PURPOSE slots and args in the TREE_VALUE slots),
3774 by adding the hash codes of the individual attributes. */
3777 attribute_hash_list (list)
3780 register int hashcode;
3782 for (hashcode = 0, tail = list; tail; tail = TREE_CHAIN (tail))
3783 /* ??? Do we want to add in TREE_VALUE too? */
3784 hashcode += TYPE_HASH (TREE_PURPOSE (tail));
3788 /* Given two lists of attributes, return true if list l2 is
3789 equivalent to l1. */
3792 attribute_list_equal (l1, l2)
3795 return attribute_list_contained (l1, l2)
3796 && attribute_list_contained (l2, l1);
3799 /* Given two lists of attributes, return true if list L2 is
3800 completely contained within L1. */
3801 /* ??? This would be faster if attribute names were stored in a canonicalized
3802 form. Otherwise, if L1 uses `foo' and L2 uses `__foo__', the long method
3803 must be used to show these elements are equivalent (which they are). */
3804 /* ??? It's not clear that attributes with arguments will always be handled
3808 attribute_list_contained (l1, l2)
3811 register tree t1, t2;
3813 /* First check the obvious, maybe the lists are identical. */
3817 /* Maybe the lists are similar. */
3818 for (t1 = l1, t2 = l2;
3820 && TREE_PURPOSE (t1) == TREE_PURPOSE (t2)
3821 && TREE_VALUE (t1) == TREE_VALUE (t2);
3822 t1 = TREE_CHAIN (t1), t2 = TREE_CHAIN (t2));
3824 /* Maybe the lists are equal. */
3825 if (t1 == 0 && t2 == 0)
3828 for (; t2; t2 = TREE_CHAIN (t2))
3831 = lookup_attribute (IDENTIFIER_POINTER (TREE_PURPOSE (t2)), l1);
3833 if (attr == NULL_TREE)
3835 if (simple_cst_equal (TREE_VALUE (t2), TREE_VALUE (attr)) != 1)
3842 /* Given two lists of types
3843 (chains of TREE_LIST nodes with types in the TREE_VALUE slots)
3844 return 1 if the lists contain the same types in the same order.
3845 Also, the TREE_PURPOSEs must match. */
3848 type_list_equal (l1, l2)
3851 register tree t1, t2;
3853 for (t1 = l1, t2 = l2; t1 && t2; t1 = TREE_CHAIN (t1), t2 = TREE_CHAIN (t2))
3854 if (TREE_VALUE (t1) != TREE_VALUE (t2)
3855 || (TREE_PURPOSE (t1) != TREE_PURPOSE (t2)
3856 && ! (1 == simple_cst_equal (TREE_PURPOSE (t1), TREE_PURPOSE (t2))
3857 && (TREE_TYPE (TREE_PURPOSE (t1))
3858 == TREE_TYPE (TREE_PURPOSE (t2))))))
3864 /* Nonzero if integer constants T1 and T2
3865 represent the same constant value. */
3868 tree_int_cst_equal (t1, t2)
3873 if (t1 == 0 || t2 == 0)
3875 if (TREE_CODE (t1) == INTEGER_CST
3876 && TREE_CODE (t2) == INTEGER_CST
3877 && TREE_INT_CST_LOW (t1) == TREE_INT_CST_LOW (t2)
3878 && TREE_INT_CST_HIGH (t1) == TREE_INT_CST_HIGH (t2))
3883 /* Nonzero if integer constants T1 and T2 represent values that satisfy <.
3884 The precise way of comparison depends on their data type. */
3887 tree_int_cst_lt (t1, t2)
3893 if (!TREE_UNSIGNED (TREE_TYPE (t1)))
3894 return INT_CST_LT (t1, t2);
3895 return INT_CST_LT_UNSIGNED (t1, t2);
3898 /* Return an indication of the sign of the integer constant T.
3899 The return value is -1 if T < 0, 0 if T == 0, and 1 if T > 0.
3900 Note that -1 will never be returned it T's type is unsigned. */
3903 tree_int_cst_sgn (t)
3906 if (TREE_INT_CST_LOW (t) == 0 && TREE_INT_CST_HIGH (t) == 0)
3908 else if (TREE_UNSIGNED (TREE_TYPE (t)))
3910 else if (TREE_INT_CST_HIGH (t) < 0)
3916 /* Compare two constructor-element-type constants. Return 1 if the lists
3917 are known to be equal; otherwise return 0. */
3920 simple_cst_list_equal (l1, l2)
3923 while (l1 != NULL_TREE && l2 != NULL_TREE)
3925 if (simple_cst_equal (TREE_VALUE (l1), TREE_VALUE (l2)) != 1)
3928 l1 = TREE_CHAIN (l1);
3929 l2 = TREE_CHAIN (l2);
3935 /* Return truthvalue of whether T1 is the same tree structure as T2.
3936 Return 1 if they are the same.
3937 Return 0 if they are understandably different.
3938 Return -1 if either contains tree structure not understood by
3942 simple_cst_equal (t1, t2)
3945 register enum tree_code code1, code2;
3950 if (t1 == 0 || t2 == 0)
3953 code1 = TREE_CODE (t1);
3954 code2 = TREE_CODE (t2);
3956 if (code1 == NOP_EXPR || code1 == CONVERT_EXPR || code1 == NON_LVALUE_EXPR)
3958 if (code2 == NOP_EXPR || code2 == CONVERT_EXPR
3959 || code2 == NON_LVALUE_EXPR)
3960 return simple_cst_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
3962 return simple_cst_equal (TREE_OPERAND (t1, 0), t2);
3964 else if (code2 == NOP_EXPR || code2 == CONVERT_EXPR
3965 || code2 == NON_LVALUE_EXPR)
3966 return simple_cst_equal (t1, TREE_OPERAND (t2, 0));
3974 return TREE_INT_CST_LOW (t1) == TREE_INT_CST_LOW (t2)
3975 && TREE_INT_CST_HIGH (t1) == TREE_INT_CST_HIGH (t2);
3978 return REAL_VALUES_IDENTICAL (TREE_REAL_CST (t1), TREE_REAL_CST (t2));
3981 return TREE_STRING_LENGTH (t1) == TREE_STRING_LENGTH (t2)
3982 && !bcmp (TREE_STRING_POINTER (t1), TREE_STRING_POINTER (t2),
3983 TREE_STRING_LENGTH (t1));
3986 if (CONSTRUCTOR_ELTS (t1) == CONSTRUCTOR_ELTS (t2))
3992 return simple_cst_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
3995 cmp = simple_cst_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
3998 return simple_cst_list_equal (TREE_OPERAND (t1, 1), TREE_OPERAND (t2, 1));
4001 /* Special case: if either target is an unallocated VAR_DECL,
4002 it means that it's going to be unified with whatever the
4003 TARGET_EXPR is really supposed to initialize, so treat it
4004 as being equivalent to anything. */
4005 if ((TREE_CODE (TREE_OPERAND (t1, 0)) == VAR_DECL
4006 && DECL_NAME (TREE_OPERAND (t1, 0)) == NULL_TREE
4007 && DECL_RTL (TREE_OPERAND (t1, 0)) == 0)
4008 || (TREE_CODE (TREE_OPERAND (t2, 0)) == VAR_DECL
4009 && DECL_NAME (TREE_OPERAND (t2, 0)) == NULL_TREE
4010 && DECL_RTL (TREE_OPERAND (t2, 0)) == 0))
4013 cmp = simple_cst_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
4016 return simple_cst_equal (TREE_OPERAND (t1, 1), TREE_OPERAND (t2, 1));
4018 case WITH_CLEANUP_EXPR:
4019 cmp = simple_cst_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
4022 return simple_cst_equal (TREE_OPERAND (t1, 2), TREE_OPERAND (t1, 2));
4025 if (TREE_OPERAND (t1, 1) == TREE_OPERAND (t2, 1))
4026 return simple_cst_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
4039 /* This general rule works for most tree codes. All exceptions should be
4040 handled above. If this is a language-specific tree code, we can't
4041 trust what might be in the operand, so say we don't know
4043 if ((int) code1 >= (int) LAST_AND_UNUSED_TREE_CODE)
4046 switch (TREE_CODE_CLASS (code1))
4056 for (i=0; i<tree_code_length[(int) code1]; ++i)
4058 cmp = simple_cst_equal (TREE_OPERAND (t1, i), TREE_OPERAND (t2, i));
4069 /* Constructors for pointer, array and function types.
4070 (RECORD_TYPE, UNION_TYPE and ENUMERAL_TYPE nodes are
4071 constructed by language-dependent code, not here.) */
4073 /* Construct, lay out and return the type of pointers to TO_TYPE.
4074 If such a type has already been constructed, reuse it. */
4077 build_pointer_type (to_type)
4080 register tree t = TYPE_POINTER_TO (to_type);
4082 /* First, if we already have a type for pointers to TO_TYPE, use it. */
4087 /* We need a new one. Put this in the same obstack as TO_TYPE. */
4088 push_obstacks (TYPE_OBSTACK (to_type), TYPE_OBSTACK (to_type));
4089 t = make_node (POINTER_TYPE);
4092 TREE_TYPE (t) = to_type;
4094 /* Record this type as the pointer to TO_TYPE. */
4095 TYPE_POINTER_TO (to_type) = t;
4097 /* Lay out the type. This function has many callers that are concerned
4098 with expression-construction, and this simplifies them all.
4099 Also, it guarantees the TYPE_SIZE is in the same obstack as the type. */
4105 /* Create a type of integers to be the TYPE_DOMAIN of an ARRAY_TYPE.
4106 MAXVAL should be the maximum value in the domain
4107 (one less than the length of the array).
4109 The maximum value that MAXVAL can have is INT_MAX for a HOST_WIDE_INT.
4110 We don't enforce this limit, that is up to caller (e.g. language front end).
4111 The limit exists because the result is a signed type and we don't handle
4112 sizes that use more than one HOST_WIDE_INT. */
4115 build_index_type (maxval)
4118 register tree itype = make_node (INTEGER_TYPE);
4120 TYPE_PRECISION (itype) = TYPE_PRECISION (sizetype);
4121 TYPE_MIN_VALUE (itype) = size_zero_node;
4123 push_obstacks (TYPE_OBSTACK (itype), TYPE_OBSTACK (itype));
4124 TYPE_MAX_VALUE (itype) = convert (sizetype, maxval);
4127 TYPE_MODE (itype) = TYPE_MODE (sizetype);
4128 TYPE_SIZE (itype) = TYPE_SIZE (sizetype);
4129 TYPE_SIZE_UNIT (itype) = TYPE_SIZE_UNIT (sizetype);
4130 TYPE_ALIGN (itype) = TYPE_ALIGN (sizetype);
4131 if (TREE_CODE (maxval) == INTEGER_CST)
4133 int maxint = (int) TREE_INT_CST_LOW (maxval);
4134 /* If the domain should be empty, make sure the maxval
4135 remains -1 and is not spoiled by truncation. */
4136 if (INT_CST_LT (maxval, integer_zero_node))
4138 TYPE_MAX_VALUE (itype) = build_int_2 (-1, -1);
4139 TREE_TYPE (TYPE_MAX_VALUE (itype)) = sizetype;
4141 return type_hash_canon (maxint < 0 ? ~maxint : maxint, itype);
4147 /* Create a range of some discrete type TYPE (an INTEGER_TYPE,
4148 ENUMERAL_TYPE, BOOLEAN_TYPE, or CHAR_TYPE), with
4149 low bound LOWVAL and high bound HIGHVAL.
4150 if TYPE==NULL_TREE, sizetype is used. */
4153 build_range_type (type, lowval, highval)
4154 tree type, lowval, highval;
4156 register tree itype = make_node (INTEGER_TYPE);
4158 TREE_TYPE (itype) = type;
4159 if (type == NULL_TREE)
4162 push_obstacks (TYPE_OBSTACK (itype), TYPE_OBSTACK (itype));
4163 TYPE_MIN_VALUE (itype) = convert (type, lowval);
4164 TYPE_MAX_VALUE (itype) = highval ? convert (type, highval) : NULL;
4167 TYPE_PRECISION (itype) = TYPE_PRECISION (type);
4168 TYPE_MODE (itype) = TYPE_MODE (type);
4169 TYPE_SIZE (itype) = TYPE_SIZE (type);
4170 TYPE_SIZE_UNIT (itype) = TYPE_SIZE_UNIT (type);
4171 TYPE_ALIGN (itype) = TYPE_ALIGN (type);
4172 if (TREE_CODE (lowval) == INTEGER_CST)
4174 HOST_WIDE_INT lowint, highint;
4177 lowint = TREE_INT_CST_LOW (lowval);
4178 if (highval && TREE_CODE (highval) == INTEGER_CST)
4179 highint = TREE_INT_CST_LOW (highval);
4181 highint = (~(unsigned HOST_WIDE_INT)0) >> 1;
4183 maxint = (int) (highint - lowint);
4184 return type_hash_canon (maxint < 0 ? ~maxint : maxint, itype);
4190 /* Just like build_index_type, but takes lowval and highval instead
4191 of just highval (maxval). */
4194 build_index_2_type (lowval,highval)
4195 tree lowval, highval;
4197 return build_range_type (NULL_TREE, lowval, highval);
4200 /* Return nonzero iff ITYPE1 and ITYPE2 are equal (in the LISP sense).
4201 Needed because when index types are not hashed, equal index types
4202 built at different times appear distinct, even though structurally,
4206 index_type_equal (itype1, itype2)
4207 tree itype1, itype2;
4209 if (TREE_CODE (itype1) != TREE_CODE (itype2))
4211 if (TREE_CODE (itype1) == INTEGER_TYPE)
4213 if (TYPE_PRECISION (itype1) != TYPE_PRECISION (itype2)
4214 || TYPE_MODE (itype1) != TYPE_MODE (itype2)
4215 || simple_cst_equal (TYPE_SIZE (itype1), TYPE_SIZE (itype2)) != 1
4216 || TYPE_ALIGN (itype1) != TYPE_ALIGN (itype2))
4218 if (1 == simple_cst_equal (TYPE_MIN_VALUE (itype1),
4219 TYPE_MIN_VALUE (itype2))
4220 && 1 == simple_cst_equal (TYPE_MAX_VALUE (itype1),
4221 TYPE_MAX_VALUE (itype2)))
4228 /* Construct, lay out and return the type of arrays of elements with ELT_TYPE
4229 and number of elements specified by the range of values of INDEX_TYPE.
4230 If such a type has already been constructed, reuse it. */
4233 build_array_type (elt_type, index_type)
4234 tree elt_type, index_type;
4239 if (TREE_CODE (elt_type) == FUNCTION_TYPE)
4241 error ("arrays of functions are not meaningful");
4242 elt_type = integer_type_node;
4245 /* Make sure TYPE_POINTER_TO (elt_type) is filled in. */
4246 build_pointer_type (elt_type);
4248 /* Allocate the array after the pointer type,
4249 in case we free it in type_hash_canon. */
4250 t = make_node (ARRAY_TYPE);
4251 TREE_TYPE (t) = elt_type;
4252 TYPE_DOMAIN (t) = index_type;
4254 if (index_type == 0)
4259 hashcode = TYPE_HASH (elt_type) + TYPE_HASH (index_type);
4260 t = type_hash_canon (hashcode, t);
4262 if (TYPE_SIZE (t) == 0)
4267 /* Return the TYPE of the elements comprising
4268 the innermost dimension of ARRAY. */
4271 get_inner_array_type (array)
4274 tree type = TREE_TYPE (array);
4276 while (TREE_CODE (type) == ARRAY_TYPE)
4277 type = TREE_TYPE (type);
4282 /* Construct, lay out and return
4283 the type of functions returning type VALUE_TYPE
4284 given arguments of types ARG_TYPES.
4285 ARG_TYPES is a chain of TREE_LIST nodes whose TREE_VALUEs
4286 are data type nodes for the arguments of the function.
4287 If such a type has already been constructed, reuse it. */
4290 build_function_type (value_type, arg_types)
4291 tree value_type, arg_types;
4296 if (TREE_CODE (value_type) == FUNCTION_TYPE)
4298 error ("function return type cannot be function");
4299 value_type = integer_type_node;
4302 /* Make a node of the sort we want. */
4303 t = make_node (FUNCTION_TYPE);
4304 TREE_TYPE (t) = value_type;
4305 TYPE_ARG_TYPES (t) = arg_types;
4307 /* If we already have such a type, use the old one and free this one. */
4308 hashcode = TYPE_HASH (value_type) + type_hash_list (arg_types);
4309 t = type_hash_canon (hashcode, t);
4311 if (TYPE_SIZE (t) == 0)
4316 /* Build the node for the type of references-to-TO_TYPE. */
4319 build_reference_type (to_type)
4322 register tree t = TYPE_REFERENCE_TO (to_type);
4324 /* First, if we already have a type for pointers to TO_TYPE, use it. */
4329 /* We need a new one. Put this in the same obstack as TO_TYPE. */
4330 push_obstacks (TYPE_OBSTACK (to_type), TYPE_OBSTACK (to_type));
4331 t = make_node (REFERENCE_TYPE);
4334 TREE_TYPE (t) = to_type;
4336 /* Record this type as the pointer to TO_TYPE. */
4337 TYPE_REFERENCE_TO (to_type) = t;
4344 /* Construct, lay out and return the type of methods belonging to class
4345 BASETYPE and whose arguments and values are described by TYPE.
4346 If that type exists already, reuse it.
4347 TYPE must be a FUNCTION_TYPE node. */
4350 build_method_type (basetype, type)
4351 tree basetype, type;
4356 /* Make a node of the sort we want. */
4357 t = make_node (METHOD_TYPE);
4359 if (TREE_CODE (type) != FUNCTION_TYPE)
4362 TYPE_METHOD_BASETYPE (t) = TYPE_MAIN_VARIANT (basetype);
4363 TREE_TYPE (t) = TREE_TYPE (type);
4365 /* The actual arglist for this function includes a "hidden" argument
4366 which is "this". Put it into the list of argument types. */
4369 = tree_cons (NULL_TREE,
4370 build_pointer_type (basetype), TYPE_ARG_TYPES (type));
4372 /* If we already have such a type, use the old one and free this one. */
4373 hashcode = TYPE_HASH (basetype) + TYPE_HASH (type);
4374 t = type_hash_canon (hashcode, t);
4376 if (TYPE_SIZE (t) == 0)
4382 /* Construct, lay out and return the type of offsets to a value
4383 of type TYPE, within an object of type BASETYPE.
4384 If a suitable offset type exists already, reuse it. */
4387 build_offset_type (basetype, type)
4388 tree basetype, type;
4393 /* Make a node of the sort we want. */
4394 t = make_node (OFFSET_TYPE);
4396 TYPE_OFFSET_BASETYPE (t) = TYPE_MAIN_VARIANT (basetype);
4397 TREE_TYPE (t) = type;
4399 /* If we already have such a type, use the old one and free this one. */
4400 hashcode = TYPE_HASH (basetype) + TYPE_HASH (type);
4401 t = type_hash_canon (hashcode, t);
4403 if (TYPE_SIZE (t) == 0)
4409 /* Create a complex type whose components are COMPONENT_TYPE. */
4412 build_complex_type (component_type)
4413 tree component_type;
4418 /* Make a node of the sort we want. */
4419 t = make_node (COMPLEX_TYPE);
4421 TREE_TYPE (t) = TYPE_MAIN_VARIANT (component_type);
4422 set_type_quals (t, TYPE_QUALS (component_type));
4424 /* If we already have such a type, use the old one and free this one. */
4425 hashcode = TYPE_HASH (component_type);
4426 t = type_hash_canon (hashcode, t);
4428 if (TYPE_SIZE (t) == 0)
4434 /* Return OP, stripped of any conversions to wider types as much as is safe.
4435 Converting the value back to OP's type makes a value equivalent to OP.
4437 If FOR_TYPE is nonzero, we return a value which, if converted to
4438 type FOR_TYPE, would be equivalent to converting OP to type FOR_TYPE.
4440 If FOR_TYPE is nonzero, unaligned bit-field references may be changed to the
4441 narrowest type that can hold the value, even if they don't exactly fit.
4442 Otherwise, bit-field references are changed to a narrower type
4443 only if they can be fetched directly from memory in that type.
4445 OP must have integer, real or enumeral type. Pointers are not allowed!
4447 There are some cases where the obvious value we could return
4448 would regenerate to OP if converted to OP's type,
4449 but would not extend like OP to wider types.
4450 If FOR_TYPE indicates such extension is contemplated, we eschew such values.
4451 For example, if OP is (unsigned short)(signed char)-1,
4452 we avoid returning (signed char)-1 if FOR_TYPE is int,
4453 even though extending that to an unsigned short would regenerate OP,
4454 since the result of extending (signed char)-1 to (int)
4455 is different from (int) OP. */
4458 get_unwidened (op, for_type)
4462 /* Set UNS initially if converting OP to FOR_TYPE is a zero-extension. */
4463 register tree type = TREE_TYPE (op);
4464 register unsigned final_prec
4465 = TYPE_PRECISION (for_type != 0 ? for_type : type);
4467 = (for_type != 0 && for_type != type
4468 && final_prec > TYPE_PRECISION (type)
4469 && TREE_UNSIGNED (type));
4470 register tree win = op;
4472 while (TREE_CODE (op) == NOP_EXPR)
4474 register int bitschange
4475 = TYPE_PRECISION (TREE_TYPE (op))
4476 - TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (op, 0)));
4478 /* Truncations are many-one so cannot be removed.
4479 Unless we are later going to truncate down even farther. */
4481 && final_prec > TYPE_PRECISION (TREE_TYPE (op)))
4484 /* See what's inside this conversion. If we decide to strip it,
4486 op = TREE_OPERAND (op, 0);
4488 /* If we have not stripped any zero-extensions (uns is 0),
4489 we can strip any kind of extension.
4490 If we have previously stripped a zero-extension,
4491 only zero-extensions can safely be stripped.
4492 Any extension can be stripped if the bits it would produce
4493 are all going to be discarded later by truncating to FOR_TYPE. */
4497 if (! uns || final_prec <= TYPE_PRECISION (TREE_TYPE (op)))
4499 /* TREE_UNSIGNED says whether this is a zero-extension.
4500 Let's avoid computing it if it does not affect WIN
4501 and if UNS will not be needed again. */
4502 if ((uns || TREE_CODE (op) == NOP_EXPR)
4503 && TREE_UNSIGNED (TREE_TYPE (op)))
4511 if (TREE_CODE (op) == COMPONENT_REF
4512 /* Since type_for_size always gives an integer type. */
4513 && TREE_CODE (type) != REAL_TYPE
4514 /* Don't crash if field not laid out yet. */
4515 && DECL_SIZE (TREE_OPERAND (op, 1)) != 0)
4517 unsigned innerprec = TREE_INT_CST_LOW (DECL_SIZE (TREE_OPERAND (op, 1)));
4518 type = type_for_size (innerprec, TREE_UNSIGNED (TREE_OPERAND (op, 1)));
4520 /* We can get this structure field in the narrowest type it fits in.
4521 If FOR_TYPE is 0, do this only for a field that matches the
4522 narrower type exactly and is aligned for it
4523 The resulting extension to its nominal type (a fullword type)
4524 must fit the same conditions as for other extensions. */
4526 if (innerprec < TYPE_PRECISION (TREE_TYPE (op))
4527 && (for_type || ! DECL_BIT_FIELD (TREE_OPERAND (op, 1)))
4528 && (! uns || final_prec <= innerprec
4529 || TREE_UNSIGNED (TREE_OPERAND (op, 1)))
4532 win = build (COMPONENT_REF, type, TREE_OPERAND (op, 0),
4533 TREE_OPERAND (op, 1));
4534 TREE_SIDE_EFFECTS (win) = TREE_SIDE_EFFECTS (op);
4535 TREE_THIS_VOLATILE (win) = TREE_THIS_VOLATILE (op);
4536 TREE_RAISES (win) = TREE_RAISES (op);
4542 /* Return OP or a simpler expression for a narrower value
4543 which can be sign-extended or zero-extended to give back OP.
4544 Store in *UNSIGNEDP_PTR either 1 if the value should be zero-extended
4545 or 0 if the value should be sign-extended. */
4548 get_narrower (op, unsignedp_ptr)
4552 register int uns = 0;
4554 register tree win = op;
4556 while (TREE_CODE (op) == NOP_EXPR)
4558 register int bitschange
4559 = TYPE_PRECISION (TREE_TYPE (op))
4560 - TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (op, 0)));
4562 /* Truncations are many-one so cannot be removed. */
4566 /* See what's inside this conversion. If we decide to strip it,
4568 op = TREE_OPERAND (op, 0);
4572 /* An extension: the outermost one can be stripped,
4573 but remember whether it is zero or sign extension. */
4575 uns = TREE_UNSIGNED (TREE_TYPE (op));
4576 /* Otherwise, if a sign extension has been stripped,
4577 only sign extensions can now be stripped;
4578 if a zero extension has been stripped, only zero-extensions. */
4579 else if (uns != TREE_UNSIGNED (TREE_TYPE (op)))
4583 else /* bitschange == 0 */
4585 /* A change in nominal type can always be stripped, but we must
4586 preserve the unsignedness. */
4588 uns = TREE_UNSIGNED (TREE_TYPE (op));
4595 if (TREE_CODE (op) == COMPONENT_REF
4596 /* Since type_for_size always gives an integer type. */
4597 && TREE_CODE (TREE_TYPE (op)) != REAL_TYPE)
4599 unsigned innerprec = TREE_INT_CST_LOW (DECL_SIZE (TREE_OPERAND (op, 1)));
4600 tree type = type_for_size (innerprec, TREE_UNSIGNED (op));
4602 /* We can get this structure field in a narrower type that fits it,
4603 but the resulting extension to its nominal type (a fullword type)
4604 must satisfy the same conditions as for other extensions.
4606 Do this only for fields that are aligned (not bit-fields),
4607 because when bit-field insns will be used there is no
4608 advantage in doing this. */
4610 if (innerprec < TYPE_PRECISION (TREE_TYPE (op))
4611 && ! DECL_BIT_FIELD (TREE_OPERAND (op, 1))
4612 && (first || uns == TREE_UNSIGNED (TREE_OPERAND (op, 1)))
4616 uns = TREE_UNSIGNED (TREE_OPERAND (op, 1));
4617 win = build (COMPONENT_REF, type, TREE_OPERAND (op, 0),
4618 TREE_OPERAND (op, 1));
4619 TREE_SIDE_EFFECTS (win) = TREE_SIDE_EFFECTS (op);
4620 TREE_THIS_VOLATILE (win) = TREE_THIS_VOLATILE (op);
4621 TREE_RAISES (win) = TREE_RAISES (op);
4624 *unsignedp_ptr = uns;
4628 /* Nonzero if integer constant C has a value that is permissible
4629 for type TYPE (an INTEGER_TYPE). */
4632 int_fits_type_p (c, type)
4635 if (TREE_UNSIGNED (type))
4636 return (! (TREE_CODE (TYPE_MAX_VALUE (type)) == INTEGER_CST
4637 && INT_CST_LT_UNSIGNED (TYPE_MAX_VALUE (type), c))
4638 && ! (TREE_CODE (TYPE_MIN_VALUE (type)) == INTEGER_CST
4639 && INT_CST_LT_UNSIGNED (c, TYPE_MIN_VALUE (type)))
4640 /* Negative ints never fit unsigned types. */
4641 && ! (TREE_INT_CST_HIGH (c) < 0
4642 && ! TREE_UNSIGNED (TREE_TYPE (c))));
4644 return (! (TREE_CODE (TYPE_MAX_VALUE (type)) == INTEGER_CST
4645 && INT_CST_LT (TYPE_MAX_VALUE (type), c))
4646 && ! (TREE_CODE (TYPE_MIN_VALUE (type)) == INTEGER_CST
4647 && INT_CST_LT (c, TYPE_MIN_VALUE (type)))
4648 /* Unsigned ints with top bit set never fit signed types. */
4649 && ! (TREE_INT_CST_HIGH (c) < 0
4650 && TREE_UNSIGNED (TREE_TYPE (c))));
4653 /* Return the innermost context enclosing DECL that is
4654 a FUNCTION_DECL, or zero if none. */
4657 decl_function_context (decl)
4662 if (TREE_CODE (decl) == ERROR_MARK)
4665 if (TREE_CODE (decl) == SAVE_EXPR)
4666 context = SAVE_EXPR_CONTEXT (decl);
4668 context = DECL_CONTEXT (decl);
4670 while (context && TREE_CODE (context) != FUNCTION_DECL)
4672 if (TREE_CODE_CLASS (TREE_CODE (context)) == 't')
4673 context = TYPE_CONTEXT (context);
4674 else if (TREE_CODE_CLASS (TREE_CODE (context)) == 'd')
4675 context = DECL_CONTEXT (context);
4676 else if (TREE_CODE (context) == BLOCK)
4677 context = BLOCK_SUPERCONTEXT (context);
4679 /* Unhandled CONTEXT !? */
4686 /* Return the innermost context enclosing DECL that is
4687 a RECORD_TYPE, UNION_TYPE or QUAL_UNION_TYPE, or zero if none.
4688 TYPE_DECLs and FUNCTION_DECLs are transparent to this function. */
4691 decl_type_context (decl)
4694 tree context = DECL_CONTEXT (decl);
4698 if (TREE_CODE (context) == RECORD_TYPE
4699 || TREE_CODE (context) == UNION_TYPE
4700 || TREE_CODE (context) == QUAL_UNION_TYPE)
4702 if (TREE_CODE (context) == TYPE_DECL
4703 || TREE_CODE (context) == FUNCTION_DECL)
4704 context = DECL_CONTEXT (context);
4705 else if (TREE_CODE (context) == BLOCK)
4706 context = BLOCK_SUPERCONTEXT (context);
4708 /* Unhandled CONTEXT!? */
4714 /* Print debugging information about the obstack O, named STR. */
4717 print_obstack_statistics (str, o)
4721 struct _obstack_chunk *chunk = o->chunk;
4725 n_alloc += o->next_free - chunk->contents;
4726 chunk = chunk->prev;
4730 n_alloc += chunk->limit - &chunk->contents[0];
4731 chunk = chunk->prev;
4733 fprintf (stderr, "obstack %s: %u bytes, %d chunks\n",
4734 str, n_alloc, n_chunks);
4737 /* Print debugging information about tree nodes generated during the compile,
4738 and any language-specific information. */
4741 dump_tree_statistics ()
4743 #ifdef GATHER_STATISTICS
4745 int total_nodes, total_bytes;
4748 fprintf (stderr, "\n??? tree nodes created\n\n");
4749 #ifdef GATHER_STATISTICS
4750 fprintf (stderr, "Kind Nodes Bytes\n");
4751 fprintf (stderr, "-------------------------------------\n");
4752 total_nodes = total_bytes = 0;
4753 for (i = 0; i < (int) all_kinds; i++)
4755 fprintf (stderr, "%-20s %6d %9d\n", tree_node_kind_names[i],
4756 tree_node_counts[i], tree_node_sizes[i]);
4757 total_nodes += tree_node_counts[i];
4758 total_bytes += tree_node_sizes[i];
4760 fprintf (stderr, "%-20s %9d\n", "identifier names", id_string_size);
4761 fprintf (stderr, "-------------------------------------\n");
4762 fprintf (stderr, "%-20s %6d %9d\n", "Total", total_nodes, total_bytes);
4763 fprintf (stderr, "-------------------------------------\n");
4765 fprintf (stderr, "(No per-node statistics)\n");
4767 print_obstack_statistics ("permanent_obstack", &permanent_obstack);
4768 print_obstack_statistics ("maybepermanent_obstack", &maybepermanent_obstack);
4769 print_obstack_statistics ("temporary_obstack", &temporary_obstack);
4770 print_obstack_statistics ("momentary_obstack", &momentary_obstack);
4771 print_obstack_statistics ("temp_decl_obstack", &temp_decl_obstack);
4772 print_lang_statistics ();
4775 #define FILE_FUNCTION_PREFIX_LEN 9
4777 #ifndef NO_DOLLAR_IN_LABEL
4778 #define FILE_FUNCTION_FORMAT "_GLOBAL_$%s$%s"
4779 #else /* NO_DOLLAR_IN_LABEL */
4780 #ifndef NO_DOT_IN_LABEL
4781 #define FILE_FUNCTION_FORMAT "_GLOBAL_.%s.%s"
4782 #else /* NO_DOT_IN_LABEL */
4783 #define FILE_FUNCTION_FORMAT "_GLOBAL__%s_%s"
4784 #endif /* NO_DOT_IN_LABEL */
4785 #endif /* NO_DOLLAR_IN_LABEL */
4787 extern char * first_global_object_name;
4788 extern char * weak_global_object_name;
4790 /* Appends 6 random characters to TEMPLATE to (hopefully) avoid name
4791 clashes in cases where we can't reliably choose a unique name.
4793 Derived from mkstemp.c in libiberty. */
4796 append_random_chars (template)
4799 static const char letters[]
4800 = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
4801 static unsigned HOST_WIDE_INT value;
4802 unsigned HOST_WIDE_INT v;
4804 #ifdef HAVE_GETTIMEOFDAY
4808 template += strlen (template);
4810 #ifdef HAVE_GETTIMEOFDAY
4811 /* Get some more or less random data. */
4812 gettimeofday (&tv, NULL);
4813 value += ((unsigned HOST_WIDE_INT) tv.tv_usec << 16) ^ tv.tv_sec ^ getpid ();
4820 /* Fill in the random bits. */
4821 template[0] = letters[v % 62];
4823 template[1] = letters[v % 62];
4825 template[2] = letters[v % 62];
4827 template[3] = letters[v % 62];
4829 template[4] = letters[v % 62];
4831 template[5] = letters[v % 62];
4836 /* Generate a name for a function unique to this translation unit.
4837 TYPE is some string to identify the purpose of this function to the
4838 linker or collect2. */
4841 get_file_function_name_long (type)
4847 if (first_global_object_name)
4848 p = first_global_object_name;
4851 /* We don't have anything that we know to be unique to this translation
4852 unit, so use what we do have and throw in some randomness. */
4854 const char *name = weak_global_object_name;
4855 const char *file = main_input_filename;
4860 file = input_filename;
4862 p = (char *) alloca (7 + strlen (name) + strlen (file));
4864 sprintf (p, "%s%s", name, file);
4865 append_random_chars (p);
4868 buf = (char *) alloca (sizeof (FILE_FUNCTION_FORMAT) + strlen (p)
4871 /* Set up the name of the file-level functions we may need. */
4872 /* Use a global object (which is already required to be unique over
4873 the program) rather than the file name (which imposes extra
4874 constraints). -- Raeburn@MIT.EDU, 10 Jan 1990. */
4875 sprintf (buf, FILE_FUNCTION_FORMAT, type, p);
4877 /* Don't need to pull weird characters out of global names. */
4878 if (p != first_global_object_name)
4880 for (p = buf+11; *p; p++)
4881 if (! ((*p >= '0' && *p <= '9')
4882 #if 0 /* we always want labels, which are valid C++ identifiers (+ `$') */
4883 #ifndef ASM_IDENTIFY_GCC /* this is required if `.' is invalid -- k. raeburn */
4887 #ifndef NO_DOLLAR_IN_LABEL /* this for `$'; unlikely, but... -- kr */
4890 #ifndef NO_DOT_IN_LABEL /* this for `.'; unlikely, but... */
4893 || (*p >= 'A' && *p <= 'Z')
4894 || (*p >= 'a' && *p <= 'z')))
4898 return get_identifier (buf);
4901 /* If KIND=='I', return a suitable global initializer (constructor) name.
4902 If KIND=='D', return a suitable global clean-up (destructor) name. */
4905 get_file_function_name (kind)
4912 return get_file_function_name_long (p);
4916 /* Expand (the constant part of) a SET_TYPE CONSTRUCTOR node.
4917 The result is placed in BUFFER (which has length BIT_SIZE),
4918 with one bit in each char ('\000' or '\001').
4920 If the constructor is constant, NULL_TREE is returned.
4921 Otherwise, a TREE_LIST of the non-constant elements is emitted. */
4924 get_set_constructor_bits (init, buffer, bit_size)
4931 HOST_WIDE_INT domain_min
4932 = TREE_INT_CST_LOW (TYPE_MIN_VALUE (TYPE_DOMAIN (TREE_TYPE (init))));
4933 tree non_const_bits = NULL_TREE;
4934 for (i = 0; i < bit_size; i++)
4937 for (vals = TREE_OPERAND (init, 1);
4938 vals != NULL_TREE; vals = TREE_CHAIN (vals))
4940 if (TREE_CODE (TREE_VALUE (vals)) != INTEGER_CST
4941 || (TREE_PURPOSE (vals) != NULL_TREE
4942 && TREE_CODE (TREE_PURPOSE (vals)) != INTEGER_CST))
4944 = tree_cons (TREE_PURPOSE (vals), TREE_VALUE (vals), non_const_bits);
4945 else if (TREE_PURPOSE (vals) != NULL_TREE)
4947 /* Set a range of bits to ones. */
4948 HOST_WIDE_INT lo_index
4949 = TREE_INT_CST_LOW (TREE_PURPOSE (vals)) - domain_min;
4950 HOST_WIDE_INT hi_index
4951 = TREE_INT_CST_LOW (TREE_VALUE (vals)) - domain_min;
4952 if (lo_index < 0 || lo_index >= bit_size
4953 || hi_index < 0 || hi_index >= bit_size)
4955 for ( ; lo_index <= hi_index; lo_index++)
4956 buffer[lo_index] = 1;
4960 /* Set a single bit to one. */
4962 = TREE_INT_CST_LOW (TREE_VALUE (vals)) - domain_min;
4963 if (index < 0 || index >= bit_size)
4965 error ("invalid initializer for bit string");
4971 return non_const_bits;
4974 /* Expand (the constant part of) a SET_TYPE CONSTRUCTOR node.
4975 The result is placed in BUFFER (which is an array of bytes).
4976 If the constructor is constant, NULL_TREE is returned.
4977 Otherwise, a TREE_LIST of the non-constant elements is emitted. */
4980 get_set_constructor_bytes (init, buffer, wd_size)
4982 unsigned char *buffer;
4986 int set_word_size = BITS_PER_UNIT;
4987 int bit_size = wd_size * set_word_size;
4989 unsigned char *bytep = buffer;
4990 char *bit_buffer = (char *) alloca(bit_size);
4991 tree non_const_bits = get_set_constructor_bits (init, bit_buffer, bit_size);
4993 for (i = 0; i < wd_size; i++)
4996 for (i = 0; i < bit_size; i++)
5000 if (BYTES_BIG_ENDIAN)
5001 *bytep |= (1 << (set_word_size - 1 - bit_pos));
5003 *bytep |= 1 << bit_pos;
5006 if (bit_pos >= set_word_size)
5007 bit_pos = 0, bytep++;
5009 return non_const_bits;
5012 #if defined ENABLE_CHECKING && (__GNUC__ > 2 || __GNUC_MINOR__ > 6)
5013 /* Complain that the tree code of NODE does not match the expected CODE.
5014 FILE, LINE, and FUNCTION are of the caller. */
5016 tree_check_failed (node, code, file, line, function)
5018 enum tree_code code;
5021 const char *function;
5023 error ("Tree check: expected %s, have %s",
5024 tree_code_name[code], tree_code_name[TREE_CODE (node)]);
5025 fancy_abort (file, line, function);
5028 /* Similar to above, except that we check for a class of tree
5029 code, given in CL. */
5031 tree_class_check_failed (node, cl, file, line, function)
5036 const char *function;
5038 error ("Tree check: expected class '%c', have '%c' (%s)",
5039 cl, TREE_CODE_CLASS (TREE_CODE (node)),
5040 tree_code_name[TREE_CODE (node)]);
5041 fancy_abort (file, line, function);
5044 #endif /* ENABLE_CHECKING */
5046 /* Return the alias set for T, which may be either a type or an
5053 if (!flag_strict_aliasing || !lang_get_alias_set)
5054 /* If we're not doing any lanaguage-specific alias analysis, just
5055 assume everything aliases everything else. */
5058 return (*lang_get_alias_set) (t);
5061 /* Return a brand-new alias set. */
5066 static int last_alias_set;
5067 if (flag_strict_aliasing)
5068 return ++last_alias_set;