1 /* Language-independent node constructors for parse phase of GNU compiler.
2 Copyright (C) 1987, 88, 92-97, 1998 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. */
51 #define obstack_chunk_alloc xmalloc
52 #define obstack_chunk_free free
54 /* Tree nodes of permanent duration are allocated in this obstack.
55 They are the identifier nodes, and everything outside of
56 the bodies and parameters of function definitions. */
58 struct obstack permanent_obstack;
60 /* The initial RTL, and all ..._TYPE nodes, in a function
61 are allocated in this obstack. Usually they are freed at the
62 end of the function, but if the function is inline they are saved.
63 For top-level functions, this is maybepermanent_obstack.
64 Separate obstacks are made for nested functions. */
66 struct obstack *function_maybepermanent_obstack;
68 /* This is the function_maybepermanent_obstack for top-level functions. */
70 struct obstack maybepermanent_obstack;
72 /* This is a list of function_maybepermanent_obstacks for top-level inline
73 functions that are compiled in the middle of compiling other functions. */
75 struct simple_obstack_stack *toplev_inline_obstacks;
77 /* Former elements of toplev_inline_obstacks that have been recycled. */
79 struct simple_obstack_stack *extra_inline_obstacks;
81 /* This is a list of function_maybepermanent_obstacks for inline functions
82 nested in the current function that were compiled in the middle of
83 compiling other functions. */
85 struct simple_obstack_stack *inline_obstacks;
87 /* The contents of the current function definition are allocated
88 in this obstack, and all are freed at the end of the function.
89 For top-level functions, this is temporary_obstack.
90 Separate obstacks are made for nested functions. */
92 struct obstack *function_obstack;
94 /* This is used for reading initializers of global variables. */
96 struct obstack temporary_obstack;
98 /* The tree nodes of an expression are allocated
99 in this obstack, and all are freed at the end of the expression. */
101 struct obstack momentary_obstack;
103 /* The tree nodes of a declarator are allocated
104 in this obstack, and all are freed when the declarator
107 static struct obstack temp_decl_obstack;
109 /* This points at either permanent_obstack
110 or the current function_maybepermanent_obstack. */
112 struct obstack *saveable_obstack;
114 /* This is same as saveable_obstack during parse and expansion phase;
115 it points to the current function's obstack during optimization.
116 This is the obstack to be used for creating rtl objects. */
118 struct obstack *rtl_obstack;
120 /* This points at either permanent_obstack or the current function_obstack. */
122 struct obstack *current_obstack;
124 /* This points at either permanent_obstack or the current function_obstack
125 or momentary_obstack. */
127 struct obstack *expression_obstack;
129 /* Stack of obstack selections for push_obstacks and pop_obstacks. */
133 struct obstack_stack *next;
134 struct obstack *current;
135 struct obstack *saveable;
136 struct obstack *expression;
140 struct obstack_stack *obstack_stack;
142 /* Obstack for allocating struct obstack_stack entries. */
144 static struct obstack obstack_stack_obstack;
146 /* Addresses of first objects in some obstacks.
147 This is for freeing their entire contents. */
148 char *maybepermanent_firstobj;
149 char *temporary_firstobj;
150 char *momentary_firstobj;
151 char *temp_decl_firstobj;
153 /* This is used to preserve objects (mainly array initializers) that need to
154 live until the end of the current function, but no further. */
155 char *momentary_function_firstobj;
157 /* Nonzero means all ..._TYPE nodes should be allocated permanently. */
159 int all_types_permanent;
161 /* Stack of places to restore the momentary obstack back to. */
163 struct momentary_level
165 /* Pointer back to previous such level. */
166 struct momentary_level *prev;
167 /* First object allocated within this level. */
169 /* Value of expression_obstack saved at entry to this level. */
170 struct obstack *obstack;
173 struct momentary_level *momentary_stack;
175 /* Table indexed by tree code giving a string containing a character
176 classifying the tree code. Possibilities are
177 t, d, s, c, r, <, 1, 2 and e. See tree.def for details. */
179 #define DEFTREECODE(SYM, NAME, TYPE, LENGTH) TYPE,
181 char tree_code_type[MAX_TREE_CODES] = {
186 /* Table indexed by tree code giving number of expression
187 operands beyond the fixed part of the node structure.
188 Not used for types or decls. */
190 #define DEFTREECODE(SYM, NAME, TYPE, LENGTH) LENGTH,
192 int tree_code_length[MAX_TREE_CODES] = {
197 /* Names of tree components.
198 Used for printing out the tree and error messages. */
199 #define DEFTREECODE(SYM, NAME, TYPE, LEN) NAME,
201 char *tree_code_name[MAX_TREE_CODES] = {
206 /* Statistics-gathering stuff. */
227 int tree_node_counts[(int)all_kinds];
228 int tree_node_sizes[(int)all_kinds];
229 int id_string_size = 0;
231 char *tree_node_kind_names[] = {
249 /* Hash table for uniquizing IDENTIFIER_NODEs by name. */
251 #define MAX_HASH_TABLE 1009
252 static tree hash_table[MAX_HASH_TABLE]; /* id hash buckets */
254 /* 0 while creating built-in identifiers. */
255 static int do_identifier_warnings;
257 /* Unique id for next decl created. */
258 static int next_decl_uid;
259 /* Unique id for next type created. */
260 static int next_type_uid = 1;
262 /* Here is how primitive or already-canonicalized types' hash
264 #define TYPE_HASH(TYPE) ((unsigned long) (TYPE) & 0777777)
266 extern char *mode_name[];
268 void gcc_obstack_init ();
270 /* Init the principal obstacks. */
275 gcc_obstack_init (&obstack_stack_obstack);
276 gcc_obstack_init (&permanent_obstack);
278 gcc_obstack_init (&temporary_obstack);
279 temporary_firstobj = (char *) obstack_alloc (&temporary_obstack, 0);
280 gcc_obstack_init (&momentary_obstack);
281 momentary_firstobj = (char *) obstack_alloc (&momentary_obstack, 0);
282 momentary_function_firstobj = momentary_firstobj;
283 gcc_obstack_init (&maybepermanent_obstack);
284 maybepermanent_firstobj
285 = (char *) obstack_alloc (&maybepermanent_obstack, 0);
286 gcc_obstack_init (&temp_decl_obstack);
287 temp_decl_firstobj = (char *) obstack_alloc (&temp_decl_obstack, 0);
289 function_obstack = &temporary_obstack;
290 function_maybepermanent_obstack = &maybepermanent_obstack;
291 current_obstack = &permanent_obstack;
292 expression_obstack = &permanent_obstack;
293 rtl_obstack = saveable_obstack = &permanent_obstack;
295 /* Init the hash table of identifiers. */
296 bzero ((char *) hash_table, sizeof hash_table);
300 gcc_obstack_init (obstack)
301 struct obstack *obstack;
303 /* Let particular systems override the size of a chunk. */
304 #ifndef OBSTACK_CHUNK_SIZE
305 #define OBSTACK_CHUNK_SIZE 0
307 /* Let them override the alloc and free routines too. */
308 #ifndef OBSTACK_CHUNK_ALLOC
309 #define OBSTACK_CHUNK_ALLOC xmalloc
311 #ifndef OBSTACK_CHUNK_FREE
312 #define OBSTACK_CHUNK_FREE free
314 _obstack_begin (obstack, OBSTACK_CHUNK_SIZE, 0,
315 (void *(*) ()) OBSTACK_CHUNK_ALLOC,
316 (void (*) ()) OBSTACK_CHUNK_FREE);
319 /* Save all variables describing the current status into the structure *P.
320 This is used before starting a nested function.
322 CONTEXT is the decl_function_context for the function we're about to
323 compile; if it isn't current_function_decl, we have to play some games. */
326 save_tree_status (p, context)
330 p->all_types_permanent = all_types_permanent;
331 p->momentary_stack = momentary_stack;
332 p->maybepermanent_firstobj = maybepermanent_firstobj;
333 p->temporary_firstobj = temporary_firstobj;
334 p->momentary_firstobj = momentary_firstobj;
335 p->momentary_function_firstobj = momentary_function_firstobj;
336 p->function_obstack = function_obstack;
337 p->function_maybepermanent_obstack = function_maybepermanent_obstack;
338 p->current_obstack = current_obstack;
339 p->expression_obstack = expression_obstack;
340 p->saveable_obstack = saveable_obstack;
341 p->rtl_obstack = rtl_obstack;
342 p->inline_obstacks = inline_obstacks;
344 if (context == current_function_decl)
345 /* Objects that need to be saved in this function can be in the nonsaved
346 obstack of the enclosing function since they can't possibly be needed
347 once it has returned. */
348 function_maybepermanent_obstack = function_obstack;
351 /* We're compiling a function which isn't nested in the current
352 function. We need to create a new maybepermanent_obstack for this
353 function, since it can't go onto any of the existing obstacks. */
354 struct simple_obstack_stack **head;
355 struct simple_obstack_stack *current;
357 if (context == NULL_TREE)
358 head = &toplev_inline_obstacks;
361 struct function *f = find_function_data (context);
362 head = &f->inline_obstacks;
365 if (context == NULL_TREE && extra_inline_obstacks)
367 current = extra_inline_obstacks;
368 extra_inline_obstacks = current->next;
372 current = ((struct simple_obstack_stack *)
373 xmalloc (sizeof (struct simple_obstack_stack)));
376 = (struct obstack *) xmalloc (sizeof (struct obstack));
377 gcc_obstack_init (current->obstack);
380 function_maybepermanent_obstack = current->obstack;
382 current->next = *head;
386 maybepermanent_firstobj
387 = (char *) obstack_finish (function_maybepermanent_obstack);
389 function_obstack = (struct obstack *) xmalloc (sizeof (struct obstack));
390 gcc_obstack_init (function_obstack);
392 current_obstack = &permanent_obstack;
393 expression_obstack = &permanent_obstack;
394 rtl_obstack = saveable_obstack = &permanent_obstack;
396 temporary_firstobj = (char *) obstack_alloc (&temporary_obstack, 0);
397 momentary_firstobj = (char *) obstack_finish (&momentary_obstack);
398 momentary_function_firstobj = momentary_firstobj;
401 /* Restore all variables describing the current status from the structure *P.
402 This is used after a nested function. */
405 restore_tree_status (p, context)
409 all_types_permanent = p->all_types_permanent;
410 momentary_stack = p->momentary_stack;
412 obstack_free (&momentary_obstack, momentary_function_firstobj);
414 /* Free saveable storage used by the function just compiled and not
417 CAUTION: This is in function_obstack of the containing function.
418 So we must be sure that we never allocate from that obstack during
419 the compilation of a nested function if we expect it to survive
420 past the nested function's end. */
421 obstack_free (function_maybepermanent_obstack, maybepermanent_firstobj);
423 /* If we were compiling a toplevel function, we can free this space now. */
424 if (context == NULL_TREE)
426 obstack_free (&temporary_obstack, temporary_firstobj);
427 obstack_free (&momentary_obstack, momentary_function_firstobj);
430 /* If we were compiling a toplevel function that we don't actually want
431 to save anything from, return the obstack to the pool. */
432 if (context == NULL_TREE
433 && obstack_empty_p (function_maybepermanent_obstack))
435 struct simple_obstack_stack *current, **p = &toplev_inline_obstacks;
439 while ((*p)->obstack != function_maybepermanent_obstack)
444 current->next = extra_inline_obstacks;
445 extra_inline_obstacks = current;
449 obstack_free (function_obstack, 0);
450 free (function_obstack);
452 temporary_firstobj = p->temporary_firstobj;
453 momentary_firstobj = p->momentary_firstobj;
454 momentary_function_firstobj = p->momentary_function_firstobj;
455 maybepermanent_firstobj = p->maybepermanent_firstobj;
456 function_obstack = p->function_obstack;
457 function_maybepermanent_obstack = p->function_maybepermanent_obstack;
458 current_obstack = p->current_obstack;
459 expression_obstack = p->expression_obstack;
460 saveable_obstack = p->saveable_obstack;
461 rtl_obstack = p->rtl_obstack;
462 inline_obstacks = p->inline_obstacks;
465 /* Start allocating on the temporary (per function) obstack.
466 This is done in start_function before parsing the function body,
467 and before each initialization at top level, and to go back
468 to temporary allocation after doing permanent_allocation. */
471 temporary_allocation ()
473 /* Note that function_obstack at top level points to temporary_obstack.
474 But within a nested function context, it is a separate obstack. */
475 current_obstack = function_obstack;
476 expression_obstack = function_obstack;
477 rtl_obstack = saveable_obstack = function_maybepermanent_obstack;
482 /* Start allocating on the permanent obstack but don't
483 free the temporary data. After calling this, call
484 `permanent_allocation' to fully resume permanent allocation status. */
487 end_temporary_allocation ()
489 current_obstack = &permanent_obstack;
490 expression_obstack = &permanent_obstack;
491 rtl_obstack = saveable_obstack = &permanent_obstack;
494 /* Resume allocating on the temporary obstack, undoing
495 effects of `end_temporary_allocation'. */
498 resume_temporary_allocation ()
500 current_obstack = function_obstack;
501 expression_obstack = function_obstack;
502 rtl_obstack = saveable_obstack = function_maybepermanent_obstack;
505 /* While doing temporary allocation, switch to allocating in such a
506 way as to save all nodes if the function is inlined. Call
507 resume_temporary_allocation to go back to ordinary temporary
511 saveable_allocation ()
513 /* Note that function_obstack at top level points to temporary_obstack.
514 But within a nested function context, it is a separate obstack. */
515 expression_obstack = current_obstack = saveable_obstack;
518 /* Switch to current obstack CURRENT and maybepermanent obstack SAVEABLE,
519 recording the previously current obstacks on a stack.
520 This does not free any storage in any obstack. */
523 push_obstacks (current, saveable)
524 struct obstack *current, *saveable;
526 struct obstack_stack *p
527 = (struct obstack_stack *) obstack_alloc (&obstack_stack_obstack,
528 (sizeof (struct obstack_stack)));
530 p->current = current_obstack;
531 p->saveable = saveable_obstack;
532 p->expression = expression_obstack;
533 p->rtl = rtl_obstack;
534 p->next = obstack_stack;
537 current_obstack = current;
538 expression_obstack = current;
539 rtl_obstack = saveable_obstack = saveable;
542 /* Save the current set of obstacks, but don't change them. */
545 push_obstacks_nochange ()
547 struct obstack_stack *p
548 = (struct obstack_stack *) obstack_alloc (&obstack_stack_obstack,
549 (sizeof (struct obstack_stack)));
551 p->current = current_obstack;
552 p->saveable = saveable_obstack;
553 p->expression = expression_obstack;
554 p->rtl = rtl_obstack;
555 p->next = obstack_stack;
559 /* Pop the obstack selection stack. */
564 struct obstack_stack *p = obstack_stack;
565 obstack_stack = p->next;
567 current_obstack = p->current;
568 saveable_obstack = p->saveable;
569 expression_obstack = p->expression;
570 rtl_obstack = p->rtl;
572 obstack_free (&obstack_stack_obstack, p);
575 /* Nonzero if temporary allocation is currently in effect.
576 Zero if currently doing permanent allocation. */
579 allocation_temporary_p ()
581 return current_obstack != &permanent_obstack;
584 /* Go back to allocating on the permanent obstack
585 and free everything in the temporary obstack.
587 FUNCTION_END is true only if we have just finished compiling a function.
588 In that case, we also free preserved initial values on the momentary
592 permanent_allocation (function_end)
595 /* Free up previous temporary obstack data */
596 obstack_free (&temporary_obstack, temporary_firstobj);
599 obstack_free (&momentary_obstack, momentary_function_firstobj);
600 momentary_firstobj = momentary_function_firstobj;
603 obstack_free (&momentary_obstack, momentary_firstobj);
604 obstack_free (function_maybepermanent_obstack, maybepermanent_firstobj);
605 obstack_free (&temp_decl_obstack, temp_decl_firstobj);
607 /* Free up the maybepermanent_obstacks for any of our nested functions
608 which were compiled at a lower level. */
609 while (inline_obstacks)
611 struct simple_obstack_stack *current = inline_obstacks;
612 inline_obstacks = current->next;
613 obstack_free (current->obstack, 0);
614 free (current->obstack);
618 current_obstack = &permanent_obstack;
619 expression_obstack = &permanent_obstack;
620 rtl_obstack = saveable_obstack = &permanent_obstack;
623 /* Save permanently everything on the maybepermanent_obstack. */
628 maybepermanent_firstobj
629 = (char *) obstack_alloc (function_maybepermanent_obstack, 0);
633 preserve_initializer ()
635 struct momentary_level *tem;
639 = (char *) obstack_alloc (&temporary_obstack, 0);
640 maybepermanent_firstobj
641 = (char *) obstack_alloc (function_maybepermanent_obstack, 0);
643 old_momentary = momentary_firstobj;
645 = (char *) obstack_alloc (&momentary_obstack, 0);
646 if (momentary_firstobj != old_momentary)
647 for (tem = momentary_stack; tem; tem = tem->prev)
648 tem->base = momentary_firstobj;
651 /* Start allocating new rtl in current_obstack.
652 Use resume_temporary_allocation
653 to go back to allocating rtl in saveable_obstack. */
656 rtl_in_current_obstack ()
658 rtl_obstack = current_obstack;
661 /* Start allocating rtl from saveable_obstack. Intended to be used after
662 a call to push_obstacks_nochange. */
665 rtl_in_saveable_obstack ()
667 rtl_obstack = saveable_obstack;
670 /* Allocate SIZE bytes in the current obstack
671 and return a pointer to them.
672 In practice the current obstack is always the temporary one. */
678 return (char *) obstack_alloc (current_obstack, size);
681 /* Free the object PTR in the current obstack
682 as well as everything allocated since PTR.
683 In practice the current obstack is always the temporary one. */
689 obstack_free (current_obstack, ptr);
692 /* Allocate SIZE bytes in the permanent obstack
693 and return a pointer to them. */
699 return (char *) obstack_alloc (&permanent_obstack, size);
702 /* Allocate NELEM items of SIZE bytes in the permanent obstack
703 and return a pointer to them. The storage is cleared before
704 returning the value. */
707 perm_calloc (nelem, size)
711 char *rval = (char *) obstack_alloc (&permanent_obstack, nelem * size);
712 bzero (rval, nelem * size);
716 /* Allocate SIZE bytes in the saveable obstack
717 and return a pointer to them. */
723 return (char *) obstack_alloc (saveable_obstack, size);
726 /* Allocate SIZE bytes in the expression obstack
727 and return a pointer to them. */
733 return (char *) obstack_alloc (expression_obstack, size);
736 /* Print out which obstack an object is in. */
739 print_obstack_name (object, file, prefix)
744 struct obstack *obstack = NULL;
745 char *obstack_name = NULL;
748 for (p = outer_function_chain; p; p = p->next)
750 if (_obstack_allocated_p (p->function_obstack, object))
752 obstack = p->function_obstack;
753 obstack_name = "containing function obstack";
755 if (_obstack_allocated_p (p->function_maybepermanent_obstack, object))
757 obstack = p->function_maybepermanent_obstack;
758 obstack_name = "containing function maybepermanent obstack";
762 if (_obstack_allocated_p (&obstack_stack_obstack, object))
764 obstack = &obstack_stack_obstack;
765 obstack_name = "obstack_stack_obstack";
767 else if (_obstack_allocated_p (function_obstack, object))
769 obstack = function_obstack;
770 obstack_name = "function obstack";
772 else if (_obstack_allocated_p (&permanent_obstack, object))
774 obstack = &permanent_obstack;
775 obstack_name = "permanent_obstack";
777 else if (_obstack_allocated_p (&momentary_obstack, object))
779 obstack = &momentary_obstack;
780 obstack_name = "momentary_obstack";
782 else if (_obstack_allocated_p (function_maybepermanent_obstack, object))
784 obstack = function_maybepermanent_obstack;
785 obstack_name = "function maybepermanent obstack";
787 else if (_obstack_allocated_p (&temp_decl_obstack, object))
789 obstack = &temp_decl_obstack;
790 obstack_name = "temp_decl_obstack";
793 /* Check to see if the object is in the free area of the obstack. */
796 if (object >= obstack->next_free
797 && object < obstack->chunk_limit)
798 fprintf (file, "%s in free portion of obstack %s",
799 prefix, obstack_name);
801 fprintf (file, "%s allocated from %s", prefix, obstack_name);
804 fprintf (file, "%s not allocated from any obstack", prefix);
808 debug_obstack (object)
811 print_obstack_name (object, stderr, "object");
812 fprintf (stderr, ".\n");
815 /* Return 1 if OBJ is in the permanent obstack.
816 This is slow, and should be used only for debugging.
817 Use TREE_PERMANENT for other purposes. */
820 object_permanent_p (obj)
823 return _obstack_allocated_p (&permanent_obstack, obj);
826 /* Start a level of momentary allocation.
827 In C, each compound statement has its own level
828 and that level is freed at the end of each statement.
829 All expression nodes are allocated in the momentary allocation level. */
834 struct momentary_level *tem
835 = (struct momentary_level *) obstack_alloc (&momentary_obstack,
836 sizeof (struct momentary_level));
837 tem->prev = momentary_stack;
838 tem->base = (char *) obstack_base (&momentary_obstack);
839 tem->obstack = expression_obstack;
840 momentary_stack = tem;
841 expression_obstack = &momentary_obstack;
844 /* Set things up so the next clear_momentary will only clear memory
845 past our present position in momentary_obstack. */
848 preserve_momentary ()
850 momentary_stack->base = (char *) obstack_base (&momentary_obstack);
853 /* Free all the storage in the current momentary-allocation level.
854 In C, this happens at the end of each statement. */
859 obstack_free (&momentary_obstack, momentary_stack->base);
862 /* Discard a level of momentary allocation.
863 In C, this happens at the end of each compound statement.
864 Restore the status of expression node allocation
865 that was in effect before this level was created. */
870 struct momentary_level *tem = momentary_stack;
871 momentary_stack = tem->prev;
872 expression_obstack = tem->obstack;
873 /* We can't free TEM from the momentary_obstack, because there might
874 be objects above it which have been saved. We can free back to the
875 stack of the level we are popping off though. */
876 obstack_free (&momentary_obstack, tem->base);
879 /* Pop back to the previous level of momentary allocation,
880 but don't free any momentary data just yet. */
883 pop_momentary_nofree ()
885 struct momentary_level *tem = momentary_stack;
886 momentary_stack = tem->prev;
887 expression_obstack = tem->obstack;
890 /* Call when starting to parse a declaration:
891 make expressions in the declaration last the length of the function.
892 Returns an argument that should be passed to resume_momentary later. */
897 register int tem = expression_obstack == &momentary_obstack;
898 expression_obstack = saveable_obstack;
902 /* Call when finished parsing a declaration:
903 restore the treatment of node-allocation that was
904 in effect before the suspension.
905 YES should be the value previously returned by suspend_momentary. */
908 resume_momentary (yes)
912 expression_obstack = &momentary_obstack;
915 /* Init the tables indexed by tree code.
916 Note that languages can add to these tables to define their own codes. */
924 /* Return a newly allocated node of code CODE.
925 Initialize the node's unique id and its TREE_PERMANENT flag.
926 For decl and type nodes, some other fields are initialized.
927 The rest of the node is initialized to zero.
929 Achoo! I got a code in the node. */
936 register int type = TREE_CODE_CLASS (code);
938 register struct obstack *obstack = current_obstack;
940 #ifdef GATHER_STATISTICS
941 register tree_node_kind kind;
946 case 'd': /* A decl node */
947 #ifdef GATHER_STATISTICS
950 length = sizeof (struct tree_decl);
951 /* All decls in an inline function need to be saved. */
952 if (obstack != &permanent_obstack)
953 obstack = saveable_obstack;
955 /* PARM_DECLs go on the context of the parent. If this is a nested
956 function, then we must allocate the PARM_DECL on the parent's
957 obstack, so that they will live to the end of the parent's
958 closing brace. This is necessary in case we try to inline the
959 function into its parent.
961 PARM_DECLs of top-level functions do not have this problem. However,
962 we allocate them where we put the FUNCTION_DECL for languages such as
963 Ada that need to consult some flags in the PARM_DECLs of the function
966 See comment in restore_tree_status for why we can't put this
967 in function_obstack. */
968 if (code == PARM_DECL && obstack != &permanent_obstack)
971 if (current_function_decl)
972 context = decl_function_context (current_function_decl);
976 = find_function_data (context)->function_maybepermanent_obstack;
980 case 't': /* a type node */
981 #ifdef GATHER_STATISTICS
984 length = sizeof (struct tree_type);
985 /* All data types are put where we can preserve them if nec. */
986 if (obstack != &permanent_obstack)
987 obstack = all_types_permanent ? &permanent_obstack : saveable_obstack;
990 case 'b': /* a lexical block */
991 #ifdef GATHER_STATISTICS
994 length = sizeof (struct tree_block);
995 /* All BLOCK nodes are put where we can preserve them if nec. */
996 if (obstack != &permanent_obstack)
997 obstack = saveable_obstack;
1000 case 's': /* an expression with side effects */
1001 #ifdef GATHER_STATISTICS
1005 case 'r': /* a reference */
1006 #ifdef GATHER_STATISTICS
1010 case 'e': /* an expression */
1011 case '<': /* a comparison expression */
1012 case '1': /* a unary arithmetic expression */
1013 case '2': /* a binary arithmetic expression */
1014 #ifdef GATHER_STATISTICS
1018 obstack = expression_obstack;
1019 /* All BIND_EXPR nodes are put where we can preserve them if nec. */
1020 if (code == BIND_EXPR && obstack != &permanent_obstack)
1021 obstack = saveable_obstack;
1022 length = sizeof (struct tree_exp)
1023 + (tree_code_length[(int) code] - 1) * sizeof (char *);
1026 case 'c': /* a constant */
1027 #ifdef GATHER_STATISTICS
1030 obstack = expression_obstack;
1032 /* We can't use tree_code_length for INTEGER_CST, since the number of
1033 words is machine-dependent due to varying length of HOST_WIDE_INT,
1034 which might be wider than a pointer (e.g., long long). Similarly
1035 for REAL_CST, since the number of words is machine-dependent due
1036 to varying size and alignment of `double'. */
1038 if (code == INTEGER_CST)
1039 length = sizeof (struct tree_int_cst);
1040 else if (code == REAL_CST)
1041 length = sizeof (struct tree_real_cst);
1043 length = sizeof (struct tree_common)
1044 + tree_code_length[(int) code] * sizeof (char *);
1047 case 'x': /* something random, like an identifier. */
1048 #ifdef GATHER_STATISTICS
1049 if (code == IDENTIFIER_NODE)
1051 else if (code == OP_IDENTIFIER)
1053 else if (code == TREE_VEC)
1058 length = sizeof (struct tree_common)
1059 + tree_code_length[(int) code] * sizeof (char *);
1060 /* Identifier nodes are always permanent since they are
1061 unique in a compiler run. */
1062 if (code == IDENTIFIER_NODE) obstack = &permanent_obstack;
1069 t = (tree) obstack_alloc (obstack, length);
1071 #ifdef GATHER_STATISTICS
1072 tree_node_counts[(int)kind]++;
1073 tree_node_sizes[(int)kind] += length;
1076 /* Clear a word at a time. */
1077 for (i = (length / sizeof (int)) - 1; i >= 0; i--)
1079 /* Clear any extra bytes. */
1080 for (i = length / sizeof (int) * sizeof (int); i < length; i++)
1081 ((char *) t)[i] = 0;
1083 TREE_SET_CODE (t, code);
1084 if (obstack == &permanent_obstack)
1085 TREE_PERMANENT (t) = 1;
1090 TREE_SIDE_EFFECTS (t) = 1;
1091 TREE_TYPE (t) = void_type_node;
1095 if (code != FUNCTION_DECL)
1097 DECL_IN_SYSTEM_HEADER (t)
1098 = in_system_header && (obstack == &permanent_obstack);
1099 DECL_SOURCE_LINE (t) = lineno;
1100 DECL_SOURCE_FILE (t) = (input_filename) ? input_filename : "<built-in>";
1101 DECL_UID (t) = next_decl_uid++;
1105 TYPE_UID (t) = next_type_uid++;
1107 TYPE_MAIN_VARIANT (t) = t;
1108 TYPE_OBSTACK (t) = obstack;
1109 TYPE_ATTRIBUTES (t) = NULL_TREE;
1110 #ifdef SET_DEFAULT_TYPE_ATTRIBUTES
1111 SET_DEFAULT_TYPE_ATTRIBUTES (t);
1116 TREE_CONSTANT (t) = 1;
1123 /* Return a new node with the same contents as NODE
1124 except that its TREE_CHAIN is zero and it has a fresh uid. */
1131 register enum tree_code code = TREE_CODE (node);
1132 register int length = 0;
1135 switch (TREE_CODE_CLASS (code))
1137 case 'd': /* A decl node */
1138 length = sizeof (struct tree_decl);
1141 case 't': /* a type node */
1142 length = sizeof (struct tree_type);
1145 case 'b': /* a lexical block node */
1146 length = sizeof (struct tree_block);
1149 case 'r': /* a reference */
1150 case 'e': /* an expression */
1151 case 's': /* an expression with side effects */
1152 case '<': /* a comparison expression */
1153 case '1': /* a unary arithmetic expression */
1154 case '2': /* a binary arithmetic expression */
1155 length = sizeof (struct tree_exp)
1156 + (tree_code_length[(int) code] - 1) * sizeof (char *);
1159 case 'c': /* a constant */
1160 /* We can't use tree_code_length for INTEGER_CST, since the number of
1161 words is machine-dependent due to varying length of HOST_WIDE_INT,
1162 which might be wider than a pointer (e.g., long long). Similarly
1163 for REAL_CST, since the number of words is machine-dependent due
1164 to varying size and alignment of `double'. */
1165 if (code == INTEGER_CST)
1166 length = sizeof (struct tree_int_cst);
1167 else if (code == REAL_CST)
1168 length = sizeof (struct tree_real_cst);
1170 length = (sizeof (struct tree_common)
1171 + tree_code_length[(int) code] * sizeof (char *));
1174 case 'x': /* something random, like an identifier. */
1175 length = sizeof (struct tree_common)
1176 + tree_code_length[(int) code] * sizeof (char *);
1177 if (code == TREE_VEC)
1178 length += (TREE_VEC_LENGTH (node) - 1) * sizeof (char *);
1181 t = (tree) obstack_alloc (current_obstack, length);
1183 for (i = (length / sizeof (int)) - 1; i >= 0; i--)
1184 ((int *) t)[i] = ((int *) node)[i];
1185 /* Clear any extra bytes. */
1186 for (i = length / sizeof (int) * sizeof (int); i < length; i++)
1187 ((char *) t)[i] = ((char *) node)[i];
1189 /* EXPR_WITH_FILE_LOCATION must keep filename info stored in TREE_CHAIN */
1190 if (TREE_CODE (node) != EXPR_WITH_FILE_LOCATION)
1192 TREE_ASM_WRITTEN (t) = 0;
1194 if (TREE_CODE_CLASS (code) == 'd')
1195 DECL_UID (t) = next_decl_uid++;
1196 else if (TREE_CODE_CLASS (code) == 't')
1198 TYPE_UID (t) = next_type_uid++;
1199 TYPE_OBSTACK (t) = current_obstack;
1201 /* The following is so that the debug code for
1202 the copy is different from the original type.
1203 The two statements usually duplicate each other
1204 (because they clear fields of the same union),
1205 but the optimizer should catch that. */
1206 TYPE_SYMTAB_POINTER (t) = 0;
1207 TYPE_SYMTAB_ADDRESS (t) = 0;
1210 TREE_PERMANENT (t) = (current_obstack == &permanent_obstack);
1215 /* Return a copy of a chain of nodes, chained through the TREE_CHAIN field.
1216 For example, this can copy a list made of TREE_LIST nodes. */
1223 register tree prev, next;
1228 head = prev = copy_node (list);
1229 next = TREE_CHAIN (list);
1232 TREE_CHAIN (prev) = copy_node (next);
1233 prev = TREE_CHAIN (prev);
1234 next = TREE_CHAIN (next);
1241 /* Return an IDENTIFIER_NODE whose name is TEXT (a null-terminated string).
1242 If an identifier with that name has previously been referred to,
1243 the same node is returned this time. */
1246 get_identifier (text)
1247 register char *text;
1252 register int len, hash_len;
1254 /* Compute length of text in len. */
1255 for (len = 0; text[len]; len++);
1257 /* Decide how much of that length to hash on */
1259 if (warn_id_clash && len > id_clash_len)
1260 hash_len = id_clash_len;
1262 /* Compute hash code */
1263 hi = hash_len * 613 + (unsigned) text[0];
1264 for (i = 1; i < hash_len; i += 2)
1265 hi = ((hi * 613) + (unsigned) (text[i]));
1267 hi &= (1 << HASHBITS) - 1;
1268 hi %= MAX_HASH_TABLE;
1270 /* Search table for identifier */
1271 for (idp = hash_table[hi]; idp; idp = TREE_CHAIN (idp))
1272 if (IDENTIFIER_LENGTH (idp) == len
1273 && IDENTIFIER_POINTER (idp)[0] == text[0]
1274 && !bcmp (IDENTIFIER_POINTER (idp), text, len))
1275 return idp; /* <-- return if found */
1277 /* Not found; optionally warn about a similar identifier */
1278 if (warn_id_clash && do_identifier_warnings && len >= id_clash_len)
1279 for (idp = hash_table[hi]; idp; idp = TREE_CHAIN (idp))
1280 if (!strncmp (IDENTIFIER_POINTER (idp), text, id_clash_len))
1282 warning ("`%s' and `%s' identical in first %d characters",
1283 IDENTIFIER_POINTER (idp), text, id_clash_len);
1287 if (tree_code_length[(int) IDENTIFIER_NODE] < 0)
1288 abort (); /* set_identifier_size hasn't been called. */
1290 /* Not found, create one, add to chain */
1291 idp = make_node (IDENTIFIER_NODE);
1292 IDENTIFIER_LENGTH (idp) = len;
1293 #ifdef GATHER_STATISTICS
1294 id_string_size += len;
1297 IDENTIFIER_POINTER (idp) = obstack_copy0 (&permanent_obstack, text, len);
1299 TREE_CHAIN (idp) = hash_table[hi];
1300 hash_table[hi] = idp;
1301 return idp; /* <-- return if created */
1304 /* If an identifier with the name TEXT (a null-terminated string) has
1305 previously been referred to, return that node; otherwise return
1309 maybe_get_identifier (text)
1310 register char *text;
1315 register int len, hash_len;
1317 /* Compute length of text in len. */
1318 for (len = 0; text[len]; len++);
1320 /* Decide how much of that length to hash on */
1322 if (warn_id_clash && len > id_clash_len)
1323 hash_len = id_clash_len;
1325 /* Compute hash code */
1326 hi = hash_len * 613 + (unsigned) text[0];
1327 for (i = 1; i < hash_len; i += 2)
1328 hi = ((hi * 613) + (unsigned) (text[i]));
1330 hi &= (1 << HASHBITS) - 1;
1331 hi %= MAX_HASH_TABLE;
1333 /* Search table for identifier */
1334 for (idp = hash_table[hi]; idp; idp = TREE_CHAIN (idp))
1335 if (IDENTIFIER_LENGTH (idp) == len
1336 && IDENTIFIER_POINTER (idp)[0] == text[0]
1337 && !bcmp (IDENTIFIER_POINTER (idp), text, len))
1338 return idp; /* <-- return if found */
1343 /* Enable warnings on similar identifiers (if requested).
1344 Done after the built-in identifiers are created. */
1347 start_identifier_warnings ()
1349 do_identifier_warnings = 1;
1352 /* Record the size of an identifier node for the language in use.
1353 SIZE is the total size in bytes.
1354 This is called by the language-specific files. This must be
1355 called before allocating any identifiers. */
1358 set_identifier_size (size)
1361 tree_code_length[(int) IDENTIFIER_NODE]
1362 = (size - sizeof (struct tree_common)) / sizeof (tree);
1365 /* Return a newly constructed INTEGER_CST node whose constant value
1366 is specified by the two ints LOW and HI.
1367 The TREE_TYPE is set to `int'.
1369 This function should be used via the `build_int_2' macro. */
1372 build_int_2_wide (low, hi)
1373 HOST_WIDE_INT low, hi;
1375 register tree t = make_node (INTEGER_CST);
1376 TREE_INT_CST_LOW (t) = low;
1377 TREE_INT_CST_HIGH (t) = hi;
1378 TREE_TYPE (t) = integer_type_node;
1382 /* Return a new REAL_CST node whose type is TYPE and value is D. */
1385 build_real (type, d)
1392 /* Check for valid float value for this type on this target machine;
1393 if not, can print error message and store a valid value in D. */
1394 #ifdef CHECK_FLOAT_VALUE
1395 CHECK_FLOAT_VALUE (TYPE_MODE (type), d, overflow);
1398 v = make_node (REAL_CST);
1399 TREE_TYPE (v) = type;
1400 TREE_REAL_CST (v) = d;
1401 TREE_OVERFLOW (v) = TREE_CONSTANT_OVERFLOW (v) = overflow;
1405 /* Return a new REAL_CST node whose type is TYPE
1406 and whose value is the integer value of the INTEGER_CST node I. */
1408 #if !defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
1411 real_value_from_int_cst (type, i)
1416 #ifdef REAL_ARITHMETIC
1417 if (! TREE_UNSIGNED (TREE_TYPE (i)))
1418 REAL_VALUE_FROM_INT (d, TREE_INT_CST_LOW (i), TREE_INT_CST_HIGH (i),
1421 REAL_VALUE_FROM_UNSIGNED_INT (d, TREE_INT_CST_LOW (i),
1422 TREE_INT_CST_HIGH (i), TYPE_MODE (type));
1423 #else /* not REAL_ARITHMETIC */
1424 /* Some 386 compilers mishandle unsigned int to float conversions,
1425 so introduce a temporary variable E to avoid those bugs. */
1426 if (TREE_INT_CST_HIGH (i) < 0 && ! TREE_UNSIGNED (TREE_TYPE (i)))
1430 d = (double) (~ TREE_INT_CST_HIGH (i));
1431 e = ((double) ((HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2))
1432 * (double) ((HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2)));
1434 e = (double) (unsigned HOST_WIDE_INT) (~ TREE_INT_CST_LOW (i));
1442 d = (double) (unsigned HOST_WIDE_INT) TREE_INT_CST_HIGH (i);
1443 e = ((double) ((HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2))
1444 * (double) ((HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2)));
1446 e = (double) (unsigned HOST_WIDE_INT) TREE_INT_CST_LOW (i);
1449 #endif /* not REAL_ARITHMETIC */
1453 /* This function can't be implemented if we can't do arithmetic
1454 on the float representation. */
1457 build_real_from_int_cst (type, i)
1462 int overflow = TREE_OVERFLOW (i);
1464 jmp_buf float_error;
1466 v = make_node (REAL_CST);
1467 TREE_TYPE (v) = type;
1469 if (setjmp (float_error))
1476 set_float_handler (float_error);
1478 #ifdef REAL_ARITHMETIC
1479 d = real_value_from_int_cst (type, i);
1481 d = REAL_VALUE_TRUNCATE (TYPE_MODE (type),
1482 real_value_from_int_cst (type, i));
1485 /* Check for valid float value for this type on this target machine. */
1488 set_float_handler (NULL_PTR);
1490 #ifdef CHECK_FLOAT_VALUE
1491 CHECK_FLOAT_VALUE (TYPE_MODE (type), d, overflow);
1494 TREE_REAL_CST (v) = d;
1495 TREE_OVERFLOW (v) = TREE_CONSTANT_OVERFLOW (v) = overflow;
1499 #endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */
1501 /* Return a newly constructed STRING_CST node whose value is
1502 the LEN characters at STR.
1503 The TREE_TYPE is not initialized. */
1506 build_string (len, str)
1510 /* Put the string in saveable_obstack since it will be placed in the RTL
1511 for an "asm" statement and will also be kept around a while if
1512 deferring constant output in varasm.c. */
1514 register tree s = make_node (STRING_CST);
1515 TREE_STRING_LENGTH (s) = len;
1516 TREE_STRING_POINTER (s) = obstack_copy0 (saveable_obstack, str, len);
1520 /* Return a newly constructed COMPLEX_CST node whose value is
1521 specified by the real and imaginary parts REAL and IMAG.
1522 Both REAL and IMAG should be constant nodes. TYPE, if specified,
1523 will be the type of the COMPLEX_CST; otherwise a new type will be made. */
1526 build_complex (type, real, imag)
1530 register tree t = make_node (COMPLEX_CST);
1532 TREE_REALPART (t) = real;
1533 TREE_IMAGPART (t) = imag;
1534 TREE_TYPE (t) = type ? type : build_complex_type (TREE_TYPE (real));
1535 TREE_OVERFLOW (t) = TREE_OVERFLOW (real) | TREE_OVERFLOW (imag);
1536 TREE_CONSTANT_OVERFLOW (t)
1537 = TREE_CONSTANT_OVERFLOW (real) | TREE_CONSTANT_OVERFLOW (imag);
1541 /* Build a newly constructed TREE_VEC node of length LEN. */
1548 register int length = (len-1) * sizeof (tree) + sizeof (struct tree_vec);
1549 register struct obstack *obstack = current_obstack;
1552 #ifdef GATHER_STATISTICS
1553 tree_node_counts[(int)vec_kind]++;
1554 tree_node_sizes[(int)vec_kind] += length;
1557 t = (tree) obstack_alloc (obstack, length);
1559 for (i = (length / sizeof (int)) - 1; i >= 0; i--)
1562 TREE_SET_CODE (t, TREE_VEC);
1563 TREE_VEC_LENGTH (t) = len;
1564 if (obstack == &permanent_obstack)
1565 TREE_PERMANENT (t) = 1;
1570 /* Return 1 if EXPR is the integer constant zero or a complex constant
1574 integer_zerop (expr)
1579 return ((TREE_CODE (expr) == INTEGER_CST
1580 && ! TREE_CONSTANT_OVERFLOW (expr)
1581 && TREE_INT_CST_LOW (expr) == 0
1582 && TREE_INT_CST_HIGH (expr) == 0)
1583 || (TREE_CODE (expr) == COMPLEX_CST
1584 && integer_zerop (TREE_REALPART (expr))
1585 && integer_zerop (TREE_IMAGPART (expr))));
1588 /* Return 1 if EXPR is the integer constant one or the corresponding
1589 complex constant. */
1597 return ((TREE_CODE (expr) == INTEGER_CST
1598 && ! TREE_CONSTANT_OVERFLOW (expr)
1599 && TREE_INT_CST_LOW (expr) == 1
1600 && TREE_INT_CST_HIGH (expr) == 0)
1601 || (TREE_CODE (expr) == COMPLEX_CST
1602 && integer_onep (TREE_REALPART (expr))
1603 && integer_zerop (TREE_IMAGPART (expr))));
1606 /* Return 1 if EXPR is an integer containing all 1's in as much precision as
1607 it contains. Likewise for the corresponding complex constant. */
1610 integer_all_onesp (expr)
1618 if (TREE_CODE (expr) == COMPLEX_CST
1619 && integer_all_onesp (TREE_REALPART (expr))
1620 && integer_zerop (TREE_IMAGPART (expr)))
1623 else if (TREE_CODE (expr) != INTEGER_CST
1624 || TREE_CONSTANT_OVERFLOW (expr))
1627 uns = TREE_UNSIGNED (TREE_TYPE (expr));
1629 return TREE_INT_CST_LOW (expr) == -1 && TREE_INT_CST_HIGH (expr) == -1;
1631 /* Note that using TYPE_PRECISION here is wrong. We care about the
1632 actual bits, not the (arbitrary) range of the type. */
1633 prec = GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (expr)));
1634 if (prec >= HOST_BITS_PER_WIDE_INT)
1636 int high_value, shift_amount;
1638 shift_amount = prec - HOST_BITS_PER_WIDE_INT;
1640 if (shift_amount > HOST_BITS_PER_WIDE_INT)
1641 /* Can not handle precisions greater than twice the host int size. */
1643 else if (shift_amount == HOST_BITS_PER_WIDE_INT)
1644 /* Shifting by the host word size is undefined according to the ANSI
1645 standard, so we must handle this as a special case. */
1648 high_value = ((HOST_WIDE_INT) 1 << shift_amount) - 1;
1650 return TREE_INT_CST_LOW (expr) == -1
1651 && TREE_INT_CST_HIGH (expr) == high_value;
1654 return TREE_INT_CST_LOW (expr) == ((HOST_WIDE_INT) 1 << prec) - 1;
1657 /* Return 1 if EXPR is an integer constant that is a power of 2 (i.e., has only
1661 integer_pow2p (expr)
1665 HOST_WIDE_INT high, low;
1669 if (TREE_CODE (expr) == COMPLEX_CST
1670 && integer_pow2p (TREE_REALPART (expr))
1671 && integer_zerop (TREE_IMAGPART (expr)))
1674 if (TREE_CODE (expr) != INTEGER_CST || TREE_CONSTANT_OVERFLOW (expr))
1677 prec = (POINTER_TYPE_P (TREE_TYPE (expr))
1678 ? POINTER_SIZE : TYPE_PRECISION (TREE_TYPE (expr)));
1679 high = TREE_INT_CST_HIGH (expr);
1680 low = TREE_INT_CST_LOW (expr);
1682 /* First clear all bits that are beyond the type's precision in case
1683 we've been sign extended. */
1685 if (prec == 2 * HOST_BITS_PER_WIDE_INT)
1687 else if (prec > HOST_BITS_PER_WIDE_INT)
1688 high &= ~((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
1692 if (prec < HOST_BITS_PER_WIDE_INT)
1693 low &= ~((HOST_WIDE_INT) (-1) << prec);
1696 if (high == 0 && low == 0)
1699 return ((high == 0 && (low & (low - 1)) == 0)
1700 || (low == 0 && (high & (high - 1)) == 0));
1703 /* Return the power of two represented by a tree node known to be a
1711 HOST_WIDE_INT high, low;
1715 if (TREE_CODE (expr) == COMPLEX_CST)
1716 return tree_log2 (TREE_REALPART (expr));
1718 prec = (POINTER_TYPE_P (TREE_TYPE (expr))
1719 ? POINTER_SIZE : TYPE_PRECISION (TREE_TYPE (expr)));
1721 high = TREE_INT_CST_HIGH (expr);
1722 low = TREE_INT_CST_LOW (expr);
1724 /* First clear all bits that are beyond the type's precision in case
1725 we've been sign extended. */
1727 if (prec == 2 * HOST_BITS_PER_WIDE_INT)
1729 else if (prec > HOST_BITS_PER_WIDE_INT)
1730 high &= ~((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
1734 if (prec < HOST_BITS_PER_WIDE_INT)
1735 low &= ~((HOST_WIDE_INT) (-1) << prec);
1738 return (high != 0 ? HOST_BITS_PER_WIDE_INT + exact_log2 (high)
1739 : exact_log2 (low));
1742 /* Return 1 if EXPR is the real constant zero. */
1750 return ((TREE_CODE (expr) == REAL_CST
1751 && ! TREE_CONSTANT_OVERFLOW (expr)
1752 && REAL_VALUES_EQUAL (TREE_REAL_CST (expr), dconst0))
1753 || (TREE_CODE (expr) == COMPLEX_CST
1754 && real_zerop (TREE_REALPART (expr))
1755 && real_zerop (TREE_IMAGPART (expr))));
1758 /* Return 1 if EXPR is the real constant one in real or complex form. */
1766 return ((TREE_CODE (expr) == REAL_CST
1767 && ! TREE_CONSTANT_OVERFLOW (expr)
1768 && REAL_VALUES_EQUAL (TREE_REAL_CST (expr), dconst1))
1769 || (TREE_CODE (expr) == COMPLEX_CST
1770 && real_onep (TREE_REALPART (expr))
1771 && real_zerop (TREE_IMAGPART (expr))));
1774 /* Return 1 if EXPR is the real constant two. */
1782 return ((TREE_CODE (expr) == REAL_CST
1783 && ! TREE_CONSTANT_OVERFLOW (expr)
1784 && REAL_VALUES_EQUAL (TREE_REAL_CST (expr), dconst2))
1785 || (TREE_CODE (expr) == COMPLEX_CST
1786 && real_twop (TREE_REALPART (expr))
1787 && real_zerop (TREE_IMAGPART (expr))));
1790 /* Nonzero if EXP is a constant or a cast of a constant. */
1793 really_constant_p (exp)
1796 /* This is not quite the same as STRIP_NOPS. It does more. */
1797 while (TREE_CODE (exp) == NOP_EXPR
1798 || TREE_CODE (exp) == CONVERT_EXPR
1799 || TREE_CODE (exp) == NON_LVALUE_EXPR)
1800 exp = TREE_OPERAND (exp, 0);
1801 return TREE_CONSTANT (exp);
1804 /* Return first list element whose TREE_VALUE is ELEM.
1805 Return 0 if ELEM is not in LIST. */
1808 value_member (elem, list)
1813 if (elem == TREE_VALUE (list))
1815 list = TREE_CHAIN (list);
1820 /* Return first list element whose TREE_PURPOSE is ELEM.
1821 Return 0 if ELEM is not in LIST. */
1824 purpose_member (elem, list)
1829 if (elem == TREE_PURPOSE (list))
1831 list = TREE_CHAIN (list);
1836 /* Return first list element whose BINFO_TYPE is ELEM.
1837 Return 0 if ELEM is not in LIST. */
1840 binfo_member (elem, list)
1845 if (elem == BINFO_TYPE (list))
1847 list = TREE_CHAIN (list);
1852 /* Return nonzero if ELEM is part of the chain CHAIN. */
1855 chain_member (elem, chain)
1862 chain = TREE_CHAIN (chain);
1868 /* Return nonzero if ELEM is equal to TREE_VALUE (CHAIN) for any piece of
1870 /* ??? This function was added for machine specific attributes but is no
1871 longer used. It could be deleted if we could confirm all front ends
1875 chain_member_value (elem, chain)
1880 if (elem == TREE_VALUE (chain))
1882 chain = TREE_CHAIN (chain);
1888 /* Return nonzero if ELEM is equal to TREE_PURPOSE (CHAIN)
1889 for any piece of chain CHAIN. */
1890 /* ??? This function was added for machine specific attributes but is no
1891 longer used. It could be deleted if we could confirm all front ends
1895 chain_member_purpose (elem, chain)
1900 if (elem == TREE_PURPOSE (chain))
1902 chain = TREE_CHAIN (chain);
1908 /* Return the length of a chain of nodes chained through TREE_CHAIN.
1909 We expect a null pointer to mark the end of the chain.
1910 This is the Lisp primitive `length'. */
1917 register int len = 0;
1919 for (tail = t; tail; tail = TREE_CHAIN (tail))
1925 /* Concatenate two chains of nodes (chained through TREE_CHAIN)
1926 by modifying the last node in chain 1 to point to chain 2.
1927 This is the Lisp primitive `nconc'. */
1939 for (t1 = op1; TREE_CHAIN (t1); t1 = TREE_CHAIN (t1))
1941 TREE_CHAIN (t1) = op2;
1942 for (t2 = op2; t2; t2 = TREE_CHAIN (t2))
1944 abort (); /* Circularity created. */
1950 /* Return the last node in a chain of nodes (chained through TREE_CHAIN). */
1954 register tree chain;
1958 while ((next = TREE_CHAIN (chain)))
1963 /* Reverse the order of elements in the chain T,
1964 and return the new head of the chain (old last element). */
1970 register tree prev = 0, decl, next;
1971 for (decl = t; decl; decl = next)
1973 next = TREE_CHAIN (decl);
1974 TREE_CHAIN (decl) = prev;
1980 /* Given a chain CHAIN of tree nodes,
1981 construct and return a list of those nodes. */
1987 tree result = NULL_TREE;
1988 tree in_tail = chain;
1989 tree out_tail = NULL_TREE;
1993 tree next = tree_cons (NULL_TREE, in_tail, NULL_TREE);
1995 TREE_CHAIN (out_tail) = next;
1999 in_tail = TREE_CHAIN (in_tail);
2005 /* Return a newly created TREE_LIST node whose
2006 purpose and value fields are PARM and VALUE. */
2009 build_tree_list (parm, value)
2012 register tree t = make_node (TREE_LIST);
2013 TREE_PURPOSE (t) = parm;
2014 TREE_VALUE (t) = value;
2018 /* Similar, but build on the temp_decl_obstack. */
2021 build_decl_list (parm, value)
2025 register struct obstack *ambient_obstack = current_obstack;
2026 current_obstack = &temp_decl_obstack;
2027 node = build_tree_list (parm, value);
2028 current_obstack = ambient_obstack;
2032 /* Similar, but build on the expression_obstack. */
2035 build_expr_list (parm, value)
2039 register struct obstack *ambient_obstack = current_obstack;
2040 current_obstack = expression_obstack;
2041 node = build_tree_list (parm, value);
2042 current_obstack = ambient_obstack;
2046 /* Return a newly created TREE_LIST node whose
2047 purpose and value fields are PARM and VALUE
2048 and whose TREE_CHAIN is CHAIN. */
2051 tree_cons (purpose, value, chain)
2052 tree purpose, value, chain;
2055 register tree node = make_node (TREE_LIST);
2058 register tree node = (tree) obstack_alloc (current_obstack, sizeof (struct tree_list));
2059 #ifdef GATHER_STATISTICS
2060 tree_node_counts[(int)x_kind]++;
2061 tree_node_sizes[(int)x_kind] += sizeof (struct tree_list);
2064 for (i = (sizeof (struct tree_common) / sizeof (int)) - 1; i >= 0; i--)
2065 ((int *) node)[i] = 0;
2067 TREE_SET_CODE (node, TREE_LIST);
2068 if (current_obstack == &permanent_obstack)
2069 TREE_PERMANENT (node) = 1;
2072 TREE_CHAIN (node) = chain;
2073 TREE_PURPOSE (node) = purpose;
2074 TREE_VALUE (node) = value;
2078 /* Similar, but build on the temp_decl_obstack. */
2081 decl_tree_cons (purpose, value, chain)
2082 tree purpose, value, chain;
2085 register struct obstack *ambient_obstack = current_obstack;
2086 current_obstack = &temp_decl_obstack;
2087 node = tree_cons (purpose, value, chain);
2088 current_obstack = ambient_obstack;
2092 /* Similar, but build on the expression_obstack. */
2095 expr_tree_cons (purpose, value, chain)
2096 tree purpose, value, chain;
2099 register struct obstack *ambient_obstack = current_obstack;
2100 current_obstack = expression_obstack;
2101 node = tree_cons (purpose, value, chain);
2102 current_obstack = ambient_obstack;
2106 /* Same as `tree_cons' but make a permanent object. */
2109 perm_tree_cons (purpose, value, chain)
2110 tree purpose, value, chain;
2113 register struct obstack *ambient_obstack = current_obstack;
2114 current_obstack = &permanent_obstack;
2116 node = tree_cons (purpose, value, chain);
2117 current_obstack = ambient_obstack;
2121 /* Same as `tree_cons', but make this node temporary, regardless. */
2124 temp_tree_cons (purpose, value, chain)
2125 tree purpose, value, chain;
2128 register struct obstack *ambient_obstack = current_obstack;
2129 current_obstack = &temporary_obstack;
2131 node = tree_cons (purpose, value, chain);
2132 current_obstack = ambient_obstack;
2136 /* Same as `tree_cons', but save this node if the function's RTL is saved. */
2139 saveable_tree_cons (purpose, value, chain)
2140 tree purpose, value, chain;
2143 register struct obstack *ambient_obstack = current_obstack;
2144 current_obstack = saveable_obstack;
2146 node = tree_cons (purpose, value, chain);
2147 current_obstack = ambient_obstack;
2151 /* Return the size nominally occupied by an object of type TYPE
2152 when it resides in memory. The value is measured in units of bytes,
2153 and its data type is that normally used for type sizes
2154 (which is the first type created by make_signed_type or
2155 make_unsigned_type). */
2158 size_in_bytes (type)
2163 if (type == error_mark_node)
2164 return integer_zero_node;
2166 type = TYPE_MAIN_VARIANT (type);
2167 t = TYPE_SIZE_UNIT (type);
2170 incomplete_type_error (NULL_TREE, type);
2171 return integer_zero_node;
2173 if (TREE_CODE (t) == INTEGER_CST)
2174 force_fit_type (t, 0);
2179 /* Return the size of TYPE (in bytes) as a wide integer
2180 or return -1 if the size can vary or is larger than an integer. */
2183 int_size_in_bytes (type)
2188 if (type == error_mark_node)
2191 type = TYPE_MAIN_VARIANT (type);
2192 t = TYPE_SIZE_UNIT (type);
2194 || TREE_CODE (t) != INTEGER_CST
2195 || TREE_INT_CST_HIGH (t) != 0)
2198 return TREE_INT_CST_LOW (t);
2201 /* Return, as a tree node, the number of elements for TYPE (which is an
2202 ARRAY_TYPE) minus one. This counts only elements of the top array.
2204 Don't let any SAVE_EXPRs escape; if we are called as part of a cleanup
2205 action, they would get unsaved. */
2208 array_type_nelts (type)
2211 tree index_type, min, max;
2213 /* If they did it with unspecified bounds, then we should have already
2214 given an error about it before we got here. */
2215 if (! TYPE_DOMAIN (type))
2216 return error_mark_node;
2218 index_type = TYPE_DOMAIN (type);
2219 min = TYPE_MIN_VALUE (index_type);
2220 max = TYPE_MAX_VALUE (index_type);
2222 if (! TREE_CONSTANT (min))
2225 if (TREE_CODE (min) == SAVE_EXPR)
2226 min = build (RTL_EXPR, TREE_TYPE (TYPE_MIN_VALUE (index_type)), 0,
2227 SAVE_EXPR_RTL (min));
2229 min = TYPE_MIN_VALUE (index_type);
2232 if (! TREE_CONSTANT (max))
2235 if (TREE_CODE (max) == SAVE_EXPR)
2236 max = build (RTL_EXPR, TREE_TYPE (TYPE_MAX_VALUE (index_type)), 0,
2237 SAVE_EXPR_RTL (max));
2239 max = TYPE_MAX_VALUE (index_type);
2242 return (integer_zerop (min)
2244 : fold (build (MINUS_EXPR, TREE_TYPE (max), max, min)));
2247 /* Return nonzero if arg is static -- a reference to an object in
2248 static storage. This is not the same as the C meaning of `static'. */
2254 switch (TREE_CODE (arg))
2257 /* Nested functions aren't static, since taking their address
2258 involves a trampoline. */
2259 return decl_function_context (arg) == 0 || DECL_NO_STATIC_CHAIN (arg);
2261 return TREE_STATIC (arg) || DECL_EXTERNAL (arg);
2264 return TREE_STATIC (arg);
2269 /* If we are referencing a bitfield, we can't evaluate an
2270 ADDR_EXPR at compile time and so it isn't a constant. */
2272 return (! DECL_BIT_FIELD (TREE_OPERAND (arg, 1))
2273 && staticp (TREE_OPERAND (arg, 0)));
2279 /* This case is technically correct, but results in setting
2280 TREE_CONSTANT on ADDR_EXPRs that cannot be evaluated at
2283 return TREE_CONSTANT (TREE_OPERAND (arg, 0));
2287 if (TREE_CODE (TYPE_SIZE (TREE_TYPE (arg))) == INTEGER_CST
2288 && TREE_CODE (TREE_OPERAND (arg, 1)) == INTEGER_CST)
2289 return staticp (TREE_OPERAND (arg, 0));
2296 /* Wrap a SAVE_EXPR around EXPR, if appropriate.
2297 Do this to any expression which may be used in more than one place,
2298 but must be evaluated only once.
2300 Normally, expand_expr would reevaluate the expression each time.
2301 Calling save_expr produces something that is evaluated and recorded
2302 the first time expand_expr is called on it. Subsequent calls to
2303 expand_expr just reuse the recorded value.
2305 The call to expand_expr that generates code that actually computes
2306 the value is the first call *at compile time*. Subsequent calls
2307 *at compile time* generate code to use the saved value.
2308 This produces correct result provided that *at run time* control
2309 always flows through the insns made by the first expand_expr
2310 before reaching the other places where the save_expr was evaluated.
2311 You, the caller of save_expr, must make sure this is so.
2313 Constants, and certain read-only nodes, are returned with no
2314 SAVE_EXPR because that is safe. Expressions containing placeholders
2315 are not touched; see tree.def for an explanation of what these
2322 register tree t = fold (expr);
2324 /* We don't care about whether this can be used as an lvalue in this
2326 while (TREE_CODE (t) == NON_LVALUE_EXPR)
2327 t = TREE_OPERAND (t, 0);
2329 /* If the tree evaluates to a constant, then we don't want to hide that
2330 fact (i.e. this allows further folding, and direct checks for constants).
2331 However, a read-only object that has side effects cannot be bypassed.
2332 Since it is no problem to reevaluate literals, we just return the
2335 if (TREE_CONSTANT (t) || (TREE_READONLY (t) && ! TREE_SIDE_EFFECTS (t))
2336 || TREE_CODE (t) == SAVE_EXPR || TREE_CODE (t) == ERROR_MARK)
2339 /* If T contains a PLACEHOLDER_EXPR, we must evaluate it each time, since
2340 it means that the size or offset of some field of an object depends on
2341 the value within another field.
2343 Note that it must not be the case that T contains both a PLACEHOLDER_EXPR
2344 and some variable since it would then need to be both evaluated once and
2345 evaluated more than once. Front-ends must assure this case cannot
2346 happen by surrounding any such subexpressions in their own SAVE_EXPR
2347 and forcing evaluation at the proper time. */
2348 if (contains_placeholder_p (t))
2351 t = build (SAVE_EXPR, TREE_TYPE (expr), t, current_function_decl, NULL_TREE);
2353 /* This expression might be placed ahead of a jump to ensure that the
2354 value was computed on both sides of the jump. So make sure it isn't
2355 eliminated as dead. */
2356 TREE_SIDE_EFFECTS (t) = 1;
2360 /* Arrange for an expression to be expanded multiple independent
2361 times. This is useful for cleanup actions, as the backend can
2362 expand them multiple times in different places. */
2370 /* If this is already protected, no sense in protecting it again. */
2371 if (TREE_CODE (expr) == UNSAVE_EXPR)
2374 t = build1 (UNSAVE_EXPR, TREE_TYPE (expr), expr);
2375 TREE_SIDE_EFFECTS (t) = TREE_SIDE_EFFECTS (expr);
2379 /* Returns the index of the first non-tree operand for CODE, or the number
2380 of operands if all are trees. */
2384 enum tree_code code;
2394 case WITH_CLEANUP_EXPR:
2395 /* Should be defined to be 2. */
2397 case METHOD_CALL_EXPR:
2400 return tree_code_length [(int) code];
2404 /* Modify a tree in place so that all the evaluate only once things
2405 are cleared out. Return the EXPR given. */
2408 unsave_expr_now (expr)
2411 enum tree_code code;
2415 if (expr == NULL_TREE)
2418 code = TREE_CODE (expr);
2419 first_rtl = first_rtl_op (code);
2423 SAVE_EXPR_RTL (expr) = 0;
2427 TREE_OPERAND (expr, 1) = TREE_OPERAND (expr, 3);
2428 TREE_OPERAND (expr, 3) = NULL_TREE;
2432 /* I don't yet know how to emit a sequence multiple times. */
2433 if (RTL_EXPR_SEQUENCE (expr) != 0)
2438 CALL_EXPR_RTL (expr) = 0;
2439 if (TREE_OPERAND (expr, 1)
2440 && TREE_CODE (TREE_OPERAND (expr, 1)) == TREE_LIST)
2442 tree exp = TREE_OPERAND (expr, 1);
2445 unsave_expr_now (TREE_VALUE (exp));
2446 exp = TREE_CHAIN (exp);
2455 switch (TREE_CODE_CLASS (code))
2457 case 'c': /* a constant */
2458 case 't': /* a type node */
2459 case 'x': /* something random, like an identifier or an ERROR_MARK. */
2460 case 'd': /* A decl node */
2461 case 'b': /* A block node */
2464 case 'e': /* an expression */
2465 case 'r': /* a reference */
2466 case 's': /* an expression with side effects */
2467 case '<': /* a comparison expression */
2468 case '2': /* a binary arithmetic expression */
2469 case '1': /* a unary arithmetic expression */
2470 for (i = first_rtl - 1; i >= 0; i--)
2471 unsave_expr_now (TREE_OPERAND (expr, i));
2479 /* Return 1 if EXP contains a PLACEHOLDER_EXPR; i.e., if it represents a size
2480 or offset that depends on a field within a record. */
2483 contains_placeholder_p (exp)
2486 register enum tree_code code = TREE_CODE (exp);
2489 /* If we have a WITH_RECORD_EXPR, it "cancels" any PLACEHOLDER_EXPR
2490 in it since it is supplying a value for it. */
2491 if (code == WITH_RECORD_EXPR)
2493 else if (code == PLACEHOLDER_EXPR)
2496 switch (TREE_CODE_CLASS (code))
2499 /* Don't look at any PLACEHOLDER_EXPRs that might be in index or bit
2500 position computations since they will be converted into a
2501 WITH_RECORD_EXPR involving the reference, which will assume
2502 here will be valid. */
2503 return contains_placeholder_p (TREE_OPERAND (exp, 0));
2506 if (code == TREE_LIST)
2507 return (contains_placeholder_p (TREE_VALUE (exp))
2508 || (TREE_CHAIN (exp) != 0
2509 && contains_placeholder_p (TREE_CHAIN (exp))));
2518 /* Ignoring the first operand isn't quite right, but works best. */
2519 return contains_placeholder_p (TREE_OPERAND (exp, 1));
2526 return (contains_placeholder_p (TREE_OPERAND (exp, 0))
2527 || contains_placeholder_p (TREE_OPERAND (exp, 1))
2528 || contains_placeholder_p (TREE_OPERAND (exp, 2)));
2531 /* If we already know this doesn't have a placeholder, don't
2533 if (SAVE_EXPR_NOPLACEHOLDER (exp) || SAVE_EXPR_RTL (exp) != 0)
2536 SAVE_EXPR_NOPLACEHOLDER (exp) = 1;
2537 result = contains_placeholder_p (TREE_OPERAND (exp, 0));
2539 SAVE_EXPR_NOPLACEHOLDER (exp) = 0;
2544 return (TREE_OPERAND (exp, 1) != 0
2545 && contains_placeholder_p (TREE_OPERAND (exp, 1)));
2551 switch (tree_code_length[(int) code])
2554 return contains_placeholder_p (TREE_OPERAND (exp, 0));
2556 return (contains_placeholder_p (TREE_OPERAND (exp, 0))
2557 || contains_placeholder_p (TREE_OPERAND (exp, 1)));
2568 /* Return 1 if EXP contains any expressions that produce cleanups for an
2569 outer scope to deal with. Used by fold. */
2577 if (! TREE_SIDE_EFFECTS (exp))
2580 switch (TREE_CODE (exp))
2583 case WITH_CLEANUP_EXPR:
2586 case CLEANUP_POINT_EXPR:
2590 for (exp = TREE_OPERAND (exp, 1); exp; exp = TREE_CHAIN (exp))
2592 cmp = has_cleanups (TREE_VALUE (exp));
2602 /* This general rule works for most tree codes. All exceptions should be
2603 handled above. If this is a language-specific tree code, we can't
2604 trust what might be in the operand, so say we don't know
2606 if ((int) TREE_CODE (exp) >= (int) LAST_AND_UNUSED_TREE_CODE)
2609 nops = first_rtl_op (TREE_CODE (exp));
2610 for (i = 0; i < nops; i++)
2611 if (TREE_OPERAND (exp, i) != 0)
2613 int type = TREE_CODE_CLASS (TREE_CODE (TREE_OPERAND (exp, i)));
2614 if (type == 'e' || type == '<' || type == '1' || type == '2'
2615 || type == 'r' || type == 's')
2617 cmp = has_cleanups (TREE_OPERAND (exp, i));
2626 /* Given a tree EXP, a FIELD_DECL F, and a replacement value R,
2627 return a tree with all occurrences of references to F in a
2628 PLACEHOLDER_EXPR replaced by R. Note that we assume here that EXP
2629 contains only arithmetic expressions or a CALL_EXPR with a
2630 PLACEHOLDER_EXPR occurring only in its arglist. */
2633 substitute_in_expr (exp, f, r)
2638 enum tree_code code = TREE_CODE (exp);
2643 switch (TREE_CODE_CLASS (code))
2650 if (code == PLACEHOLDER_EXPR)
2652 else if (code == TREE_LIST)
2654 op0 = (TREE_CHAIN (exp) == 0
2655 ? 0 : substitute_in_expr (TREE_CHAIN (exp), f, r));
2656 op1 = substitute_in_expr (TREE_VALUE (exp), f, r);
2657 if (op0 == TREE_CHAIN (exp) && op1 == TREE_VALUE (exp))
2660 return tree_cons (TREE_PURPOSE (exp), op1, op0);
2669 switch (tree_code_length[(int) code])
2672 op0 = substitute_in_expr (TREE_OPERAND (exp, 0), f, r);
2673 if (op0 == TREE_OPERAND (exp, 0))
2676 new = fold (build1 (code, TREE_TYPE (exp), op0));
2680 /* An RTL_EXPR cannot contain a PLACEHOLDER_EXPR; a CONSTRUCTOR
2681 could, but we don't support it. */
2682 if (code == RTL_EXPR)
2684 else if (code == CONSTRUCTOR)
2687 op0 = substitute_in_expr (TREE_OPERAND (exp, 0), f, r);
2688 op1 = substitute_in_expr (TREE_OPERAND (exp, 1), f, r);
2689 if (op0 == TREE_OPERAND (exp, 0) && op1 == TREE_OPERAND (exp, 1))
2692 new = fold (build (code, TREE_TYPE (exp), op0, op1));
2696 /* It cannot be that anything inside a SAVE_EXPR contains a
2697 PLACEHOLDER_EXPR. */
2698 if (code == SAVE_EXPR)
2701 else if (code == CALL_EXPR)
2703 op1 = substitute_in_expr (TREE_OPERAND (exp, 1), f, r);
2704 if (op1 == TREE_OPERAND (exp, 1))
2707 return build (code, TREE_TYPE (exp),
2708 TREE_OPERAND (exp, 0), op1, NULL_TREE);
2711 else if (code != COND_EXPR)
2714 op0 = substitute_in_expr (TREE_OPERAND (exp, 0), f, r);
2715 op1 = substitute_in_expr (TREE_OPERAND (exp, 1), f, r);
2716 op2 = substitute_in_expr (TREE_OPERAND (exp, 2), f, r);
2717 if (op0 == TREE_OPERAND (exp, 0) && op1 == TREE_OPERAND (exp, 1)
2718 && op2 == TREE_OPERAND (exp, 2))
2721 new = fold (build (code, TREE_TYPE (exp), op0, op1, op2));
2734 /* If this expression is getting a value from a PLACEHOLDER_EXPR
2735 and it is the right field, replace it with R. */
2736 for (inner = TREE_OPERAND (exp, 0);
2737 TREE_CODE_CLASS (TREE_CODE (inner)) == 'r';
2738 inner = TREE_OPERAND (inner, 0))
2740 if (TREE_CODE (inner) == PLACEHOLDER_EXPR
2741 && TREE_OPERAND (exp, 1) == f)
2744 /* If this expression hasn't been completed let, leave it
2746 if (TREE_CODE (inner) == PLACEHOLDER_EXPR
2747 && TREE_TYPE (inner) == 0)
2750 op0 = substitute_in_expr (TREE_OPERAND (exp, 0), f, r);
2751 if (op0 == TREE_OPERAND (exp, 0))
2754 new = fold (build (code, TREE_TYPE (exp), op0,
2755 TREE_OPERAND (exp, 1)));
2759 op0 = substitute_in_expr (TREE_OPERAND (exp, 0), f, r);
2760 op1 = substitute_in_expr (TREE_OPERAND (exp, 1), f, r);
2761 op2 = substitute_in_expr (TREE_OPERAND (exp, 2), f, r);
2762 if (op0 == TREE_OPERAND (exp, 0) && op1 == TREE_OPERAND (exp, 1)
2763 && op2 == TREE_OPERAND (exp, 2))
2766 new = fold (build (code, TREE_TYPE (exp), op0, op1, op2));
2771 op0 = substitute_in_expr (TREE_OPERAND (exp, 0), f, r);
2772 if (op0 == TREE_OPERAND (exp, 0))
2775 new = fold (build1 (code, TREE_TYPE (exp), op0));
2787 TREE_READONLY (new) = TREE_READONLY (exp);
2791 /* Stabilize a reference so that we can use it any number of times
2792 without causing its operands to be evaluated more than once.
2793 Returns the stabilized reference. This works by means of save_expr,
2794 so see the caveats in the comments about save_expr.
2796 Also allows conversion expressions whose operands are references.
2797 Any other kind of expression is returned unchanged. */
2800 stabilize_reference (ref)
2803 register tree result;
2804 register enum tree_code code = TREE_CODE (ref);
2811 /* No action is needed in this case. */
2817 case FIX_TRUNC_EXPR:
2818 case FIX_FLOOR_EXPR:
2819 case FIX_ROUND_EXPR:
2821 result = build_nt (code, stabilize_reference (TREE_OPERAND (ref, 0)));
2825 result = build_nt (INDIRECT_REF,
2826 stabilize_reference_1 (TREE_OPERAND (ref, 0)));
2830 result = build_nt (COMPONENT_REF,
2831 stabilize_reference (TREE_OPERAND (ref, 0)),
2832 TREE_OPERAND (ref, 1));
2836 result = build_nt (BIT_FIELD_REF,
2837 stabilize_reference (TREE_OPERAND (ref, 0)),
2838 stabilize_reference_1 (TREE_OPERAND (ref, 1)),
2839 stabilize_reference_1 (TREE_OPERAND (ref, 2)));
2843 result = build_nt (ARRAY_REF,
2844 stabilize_reference (TREE_OPERAND (ref, 0)),
2845 stabilize_reference_1 (TREE_OPERAND (ref, 1)));
2849 /* We cannot wrap the first expression in a SAVE_EXPR, as then
2850 it wouldn't be ignored. This matters when dealing with
2852 return stabilize_reference_1 (ref);
2855 result = build1 (INDIRECT_REF, TREE_TYPE (ref),
2856 save_expr (build1 (ADDR_EXPR,
2857 build_pointer_type (TREE_TYPE (ref)),
2862 /* If arg isn't a kind of lvalue we recognize, make no change.
2863 Caller should recognize the error for an invalid lvalue. */
2868 return error_mark_node;
2871 TREE_TYPE (result) = TREE_TYPE (ref);
2872 TREE_READONLY (result) = TREE_READONLY (ref);
2873 TREE_SIDE_EFFECTS (result) = TREE_SIDE_EFFECTS (ref);
2874 TREE_THIS_VOLATILE (result) = TREE_THIS_VOLATILE (ref);
2875 TREE_RAISES (result) = TREE_RAISES (ref);
2880 /* Subroutine of stabilize_reference; this is called for subtrees of
2881 references. Any expression with side-effects must be put in a SAVE_EXPR
2882 to ensure that it is only evaluated once.
2884 We don't put SAVE_EXPR nodes around everything, because assigning very
2885 simple expressions to temporaries causes us to miss good opportunities
2886 for optimizations. Among other things, the opportunity to fold in the
2887 addition of a constant into an addressing mode often gets lost, e.g.
2888 "y[i+1] += x;". In general, we take the approach that we should not make
2889 an assignment unless we are forced into it - i.e., that any non-side effect
2890 operator should be allowed, and that cse should take care of coalescing
2891 multiple utterances of the same expression should that prove fruitful. */
2894 stabilize_reference_1 (e)
2897 register tree result;
2898 register enum tree_code code = TREE_CODE (e);
2900 /* We cannot ignore const expressions because it might be a reference
2901 to a const array but whose index contains side-effects. But we can
2902 ignore things that are actual constant or that already have been
2903 handled by this function. */
2905 if (TREE_CONSTANT (e) || code == SAVE_EXPR)
2908 switch (TREE_CODE_CLASS (code))
2918 /* If the expression has side-effects, then encase it in a SAVE_EXPR
2919 so that it will only be evaluated once. */
2920 /* The reference (r) and comparison (<) classes could be handled as
2921 below, but it is generally faster to only evaluate them once. */
2922 if (TREE_SIDE_EFFECTS (e))
2923 return save_expr (e);
2927 /* Constants need no processing. In fact, we should never reach
2932 /* Division is slow and tends to be compiled with jumps,
2933 especially the division by powers of 2 that is often
2934 found inside of an array reference. So do it just once. */
2935 if (code == TRUNC_DIV_EXPR || code == TRUNC_MOD_EXPR
2936 || code == FLOOR_DIV_EXPR || code == FLOOR_MOD_EXPR
2937 || code == CEIL_DIV_EXPR || code == CEIL_MOD_EXPR
2938 || code == ROUND_DIV_EXPR || code == ROUND_MOD_EXPR)
2939 return save_expr (e);
2940 /* Recursively stabilize each operand. */
2941 result = build_nt (code, stabilize_reference_1 (TREE_OPERAND (e, 0)),
2942 stabilize_reference_1 (TREE_OPERAND (e, 1)));
2946 /* Recursively stabilize each operand. */
2947 result = build_nt (code, stabilize_reference_1 (TREE_OPERAND (e, 0)));
2954 TREE_TYPE (result) = TREE_TYPE (e);
2955 TREE_READONLY (result) = TREE_READONLY (e);
2956 TREE_SIDE_EFFECTS (result) = TREE_SIDE_EFFECTS (e);
2957 TREE_THIS_VOLATILE (result) = TREE_THIS_VOLATILE (e);
2958 TREE_RAISES (result) = TREE_RAISES (e);
2963 /* Low-level constructors for expressions. */
2965 /* Build an expression of code CODE, data type TYPE,
2966 and operands as specified by the arguments ARG1 and following arguments.
2967 Expressions and reference nodes can be created this way.
2968 Constants, decls, types and misc nodes cannot be. */
2971 build VPROTO((enum tree_code code, tree tt, ...))
2974 enum tree_code code;
2979 register int length;
2985 code = va_arg (p, enum tree_code);
2986 tt = va_arg (p, tree);
2989 t = make_node (code);
2990 length = tree_code_length[(int) code];
2995 /* This is equivalent to the loop below, but faster. */
2996 register tree arg0 = va_arg (p, tree);
2997 register tree arg1 = va_arg (p, tree);
2998 TREE_OPERAND (t, 0) = arg0;
2999 TREE_OPERAND (t, 1) = arg1;
3000 if ((arg0 && TREE_SIDE_EFFECTS (arg0))
3001 || (arg1 && TREE_SIDE_EFFECTS (arg1)))
3002 TREE_SIDE_EFFECTS (t) = 1;
3004 = (arg0 && TREE_RAISES (arg0)) || (arg1 && TREE_RAISES (arg1));
3006 else if (length == 1)
3008 register tree arg0 = va_arg (p, tree);
3010 /* Call build1 for this! */
3011 if (TREE_CODE_CLASS (code) != 's')
3013 TREE_OPERAND (t, 0) = arg0;
3014 if (arg0 && TREE_SIDE_EFFECTS (arg0))
3015 TREE_SIDE_EFFECTS (t) = 1;
3016 TREE_RAISES (t) = (arg0 && TREE_RAISES (arg0));
3020 for (i = 0; i < length; i++)
3022 register tree operand = va_arg (p, tree);
3023 TREE_OPERAND (t, i) = operand;
3026 if (TREE_SIDE_EFFECTS (operand))
3027 TREE_SIDE_EFFECTS (t) = 1;
3028 if (TREE_RAISES (operand))
3029 TREE_RAISES (t) = 1;
3037 /* Same as above, but only builds for unary operators.
3038 Saves lions share of calls to `build'; cuts down use
3039 of varargs, which is expensive for RISC machines. */
3042 build1 (code, type, node)
3043 enum tree_code code;
3047 register struct obstack *obstack = expression_obstack;
3048 register int i, length;
3049 #ifdef GATHER_STATISTICS
3050 register tree_node_kind kind;
3054 #ifdef GATHER_STATISTICS
3055 if (TREE_CODE_CLASS (code) == 'r')
3061 length = sizeof (struct tree_exp);
3063 t = (tree) obstack_alloc (obstack, length);
3065 #ifdef GATHER_STATISTICS
3066 tree_node_counts[(int)kind]++;
3067 tree_node_sizes[(int)kind] += length;
3070 for (i = (length / sizeof (int)) - 1; i >= 0; i--)
3073 TREE_TYPE (t) = type;
3074 TREE_SET_CODE (t, code);
3076 if (obstack == &permanent_obstack)
3077 TREE_PERMANENT (t) = 1;
3079 TREE_OPERAND (t, 0) = node;
3082 if (TREE_SIDE_EFFECTS (node))
3083 TREE_SIDE_EFFECTS (t) = 1;
3084 if (TREE_RAISES (node))
3085 TREE_RAISES (t) = 1;
3091 /* Similar except don't specify the TREE_TYPE
3092 and leave the TREE_SIDE_EFFECTS as 0.
3093 It is permissible for arguments to be null,
3094 or even garbage if their values do not matter. */
3097 build_nt VPROTO((enum tree_code code, ...))
3100 enum tree_code code;
3104 register int length;
3110 code = va_arg (p, enum tree_code);
3113 t = make_node (code);
3114 length = tree_code_length[(int) code];
3116 for (i = 0; i < length; i++)
3117 TREE_OPERAND (t, i) = va_arg (p, tree);
3123 /* Similar to `build_nt', except we build
3124 on the temp_decl_obstack, regardless. */
3127 build_parse_node VPROTO((enum tree_code code, ...))
3130 enum tree_code code;
3132 register struct obstack *ambient_obstack = expression_obstack;
3135 register int length;
3141 code = va_arg (p, enum tree_code);
3144 expression_obstack = &temp_decl_obstack;
3146 t = make_node (code);
3147 length = tree_code_length[(int) code];
3149 for (i = 0; i < length; i++)
3150 TREE_OPERAND (t, i) = va_arg (p, tree);
3153 expression_obstack = ambient_obstack;
3158 /* Commented out because this wants to be done very
3159 differently. See cp-lex.c. */
3161 build_op_identifier (op1, op2)
3164 register tree t = make_node (OP_IDENTIFIER);
3165 TREE_PURPOSE (t) = op1;
3166 TREE_VALUE (t) = op2;
3171 /* Create a DECL_... node of code CODE, name NAME and data type TYPE.
3172 We do NOT enter this node in any sort of symbol table.
3174 layout_decl is used to set up the decl's storage layout.
3175 Other slots are initialized to 0 or null pointers. */
3178 build_decl (code, name, type)
3179 enum tree_code code;
3184 t = make_node (code);
3186 /* if (type == error_mark_node)
3187 type = integer_type_node; */
3188 /* That is not done, deliberately, so that having error_mark_node
3189 as the type can suppress useless errors in the use of this variable. */
3191 DECL_NAME (t) = name;
3192 DECL_ASSEMBLER_NAME (t) = name;
3193 TREE_TYPE (t) = type;
3195 if (code == VAR_DECL || code == PARM_DECL || code == RESULT_DECL)
3197 else if (code == FUNCTION_DECL)
3198 DECL_MODE (t) = FUNCTION_MODE;
3203 /* BLOCK nodes are used to represent the structure of binding contours
3204 and declarations, once those contours have been exited and their contents
3205 compiled. This information is used for outputting debugging info. */
3208 build_block (vars, tags, subblocks, supercontext, chain)
3209 tree vars, tags, subblocks, supercontext, chain;
3211 register tree block = make_node (BLOCK);
3212 BLOCK_VARS (block) = vars;
3213 BLOCK_TYPE_TAGS (block) = tags;
3214 BLOCK_SUBBLOCKS (block) = subblocks;
3215 BLOCK_SUPERCONTEXT (block) = supercontext;
3216 BLOCK_CHAIN (block) = chain;
3220 /* EXPR_WITH_FILE_LOCATION are used to keep track of the exact
3221 location where an expression or an identifier were encountered. It
3222 is necessary for languages where the frontend parser will handle
3223 recursively more than one file (Java is one of them). */
3226 build_expr_wfl (node, file, line, col)
3231 static char *last_file = 0;
3232 static tree last_filenode = NULL_TREE;
3233 register tree wfl = make_node (EXPR_WITH_FILE_LOCATION);
3235 EXPR_WFL_NODE (wfl) = node;
3236 EXPR_WFL_SET_LINECOL (wfl, line, col);
3237 if (file != last_file)
3240 last_filenode = file ? get_identifier (file) : NULL_TREE;
3242 EXPR_WFL_FILENAME_NODE (wfl) = last_filenode;
3245 TREE_SIDE_EFFECTS (wfl) = TREE_SIDE_EFFECTS (node);
3246 TREE_TYPE (wfl) = TREE_TYPE (node);
3251 /* Return a declaration like DDECL except that its DECL_MACHINE_ATTRIBUTE
3255 build_decl_attribute_variant (ddecl, attribute)
3256 tree ddecl, attribute;
3258 DECL_MACHINE_ATTRIBUTES (ddecl) = attribute;
3262 /* Return a type like TTYPE except that its TYPE_ATTRIBUTE
3265 Record such modified types already made so we don't make duplicates. */
3268 build_type_attribute_variant (ttype, attribute)
3269 tree ttype, attribute;
3271 if ( ! attribute_list_equal (TYPE_ATTRIBUTES (ttype), attribute))
3273 register int hashcode;
3274 register struct obstack *ambient_obstack = current_obstack;
3277 if (ambient_obstack != &permanent_obstack)
3278 current_obstack = TYPE_OBSTACK (ttype);
3280 ntype = copy_node (ttype);
3281 current_obstack = ambient_obstack;
3283 TYPE_POINTER_TO (ntype) = 0;
3284 TYPE_REFERENCE_TO (ntype) = 0;
3285 TYPE_ATTRIBUTES (ntype) = attribute;
3287 /* Create a new main variant of TYPE. */
3288 TYPE_MAIN_VARIANT (ntype) = ntype;
3289 TYPE_NEXT_VARIANT (ntype) = 0;
3290 TYPE_READONLY (ntype) = TYPE_VOLATILE (ntype) = 0;
3292 hashcode = TYPE_HASH (TREE_CODE (ntype))
3293 + TYPE_HASH (TREE_TYPE (ntype))
3294 + attribute_hash_list (attribute);
3296 switch (TREE_CODE (ntype))
3299 hashcode += TYPE_HASH (TYPE_ARG_TYPES (ntype));
3302 hashcode += TYPE_HASH (TYPE_DOMAIN (ntype));
3305 hashcode += TYPE_HASH (TYPE_MAX_VALUE (ntype));
3308 hashcode += TYPE_HASH (TYPE_PRECISION (ntype));
3314 ntype = type_hash_canon (hashcode, ntype);
3315 ttype = build_type_variant (ntype, TYPE_READONLY (ttype),
3316 TYPE_VOLATILE (ttype));
3322 /* Return a 1 if ATTR_NAME and ATTR_ARGS is valid for either declaration DECL
3323 or type TYPE and 0 otherwise. Validity is determined the configuration
3324 macros VALID_MACHINE_DECL_ATTRIBUTE and VALID_MACHINE_TYPE_ATTRIBUTE. */
3327 valid_machine_attribute (attr_name, attr_args, decl, type)
3328 tree attr_name, attr_args;
3333 #ifdef VALID_MACHINE_DECL_ATTRIBUTE
3334 tree decl_attr_list = decl != 0 ? DECL_MACHINE_ATTRIBUTES (decl) : 0;
3336 #ifdef VALID_MACHINE_TYPE_ATTRIBUTE
3337 tree type_attr_list = TYPE_ATTRIBUTES (type);
3340 if (TREE_CODE (attr_name) != IDENTIFIER_NODE)
3343 #ifdef VALID_MACHINE_DECL_ATTRIBUTE
3345 && VALID_MACHINE_DECL_ATTRIBUTE (decl, decl_attr_list, attr_name, attr_args))
3347 tree attr = lookup_attribute (IDENTIFIER_POINTER (attr_name),
3350 if (attr != NULL_TREE)
3352 /* Override existing arguments. Declarations are unique so we can
3353 modify this in place. */
3354 TREE_VALUE (attr) = attr_args;
3358 decl_attr_list = tree_cons (attr_name, attr_args, decl_attr_list);
3359 decl = build_decl_attribute_variant (decl, decl_attr_list);
3366 #ifdef VALID_MACHINE_TYPE_ATTRIBUTE
3367 if (VALID_MACHINE_TYPE_ATTRIBUTE (type, type_attr_list, attr_name, attr_args))
3369 tree attr = lookup_attribute (IDENTIFIER_POINTER (attr_name),
3372 if (attr != NULL_TREE)
3374 /* Override existing arguments.
3375 ??? This currently works since attribute arguments are not
3376 included in `attribute_hash_list'. Something more complicated
3377 may be needed in the future. */
3378 TREE_VALUE (attr) = attr_args;
3382 type_attr_list = tree_cons (attr_name, attr_args, type_attr_list);
3383 type = build_type_attribute_variant (type, type_attr_list);
3386 TREE_TYPE (decl) = type;
3390 /* Handle putting a type attribute on pointer-to-function-type by putting
3391 the attribute on the function type. */
3392 else if (POINTER_TYPE_P (type)
3393 && TREE_CODE (TREE_TYPE (type)) == FUNCTION_TYPE
3394 && VALID_MACHINE_TYPE_ATTRIBUTE (TREE_TYPE (type), type_attr_list,
3395 attr_name, attr_args))
3397 tree inner_type = TREE_TYPE (type);
3398 tree inner_attr_list = TYPE_ATTRIBUTES (inner_type);
3399 tree attr = lookup_attribute (IDENTIFIER_POINTER (attr_name),
3402 if (attr != NULL_TREE)
3403 TREE_VALUE (attr) = attr_args;
3406 inner_attr_list = tree_cons (attr_name, attr_args, inner_attr_list);
3407 inner_type = build_type_attribute_variant (inner_type,
3412 TREE_TYPE (decl) = build_pointer_type (inner_type);
3421 /* Return non-zero if IDENT is a valid name for attribute ATTR,
3424 We try both `text' and `__text__', ATTR may be either one. */
3425 /* ??? It might be a reasonable simplification to require ATTR to be only
3426 `text'. One might then also require attribute lists to be stored in
3427 their canonicalized form. */
3430 is_attribute_p (attr, ident)
3434 int ident_len, attr_len;
3437 if (TREE_CODE (ident) != IDENTIFIER_NODE)
3440 if (strcmp (attr, IDENTIFIER_POINTER (ident)) == 0)
3443 p = IDENTIFIER_POINTER (ident);
3444 ident_len = strlen (p);
3445 attr_len = strlen (attr);
3447 /* If ATTR is `__text__', IDENT must be `text'; and vice versa. */
3451 || attr[attr_len - 2] != '_'
3452 || attr[attr_len - 1] != '_')
3454 if (ident_len == attr_len - 4
3455 && strncmp (attr + 2, p, attr_len - 4) == 0)
3460 if (ident_len == attr_len + 4
3461 && p[0] == '_' && p[1] == '_'
3462 && p[ident_len - 2] == '_' && p[ident_len - 1] == '_'
3463 && strncmp (attr, p + 2, attr_len) == 0)
3470 /* Given an attribute name and a list of attributes, return a pointer to the
3471 attribute's list element if the attribute is part of the list, or NULL_TREE
3475 lookup_attribute (attr_name, list)
3481 for (l = list; l; l = TREE_CHAIN (l))
3483 if (TREE_CODE (TREE_PURPOSE (l)) != IDENTIFIER_NODE)
3485 if (is_attribute_p (attr_name, TREE_PURPOSE (l)))
3492 /* Return an attribute list that is the union of a1 and a2. */
3495 merge_attributes (a1, a2)
3496 register tree a1, a2;
3500 /* Either one unset? Take the set one. */
3502 if (! (attributes = a1))
3505 /* One that completely contains the other? Take it. */
3507 else if (a2 && ! attribute_list_contained (a1, a2))
3509 if (attribute_list_contained (a2, a1))
3513 /* Pick the longest list, and hang on the other list. */
3514 /* ??? For the moment we punt on the issue of attrs with args. */
3516 if (list_length (a1) < list_length (a2))
3517 attributes = a2, a2 = a1;
3519 for (; a2; a2 = TREE_CHAIN (a2))
3520 if (lookup_attribute (IDENTIFIER_POINTER (TREE_PURPOSE (a2)),
3521 attributes) == NULL_TREE)
3523 a1 = copy_node (a2);
3524 TREE_CHAIN (a1) = attributes;
3532 /* Given types T1 and T2, merge their attributes and return
3536 merge_machine_type_attributes (t1, t2)
3539 #ifdef MERGE_MACHINE_TYPE_ATTRIBUTES
3540 return MERGE_MACHINE_TYPE_ATTRIBUTES (t1, t2);
3542 return merge_attributes (TYPE_ATTRIBUTES (t1),
3543 TYPE_ATTRIBUTES (t2));
3547 /* Given decls OLDDECL and NEWDECL, merge their attributes and return
3551 merge_machine_decl_attributes (olddecl, newdecl)
3552 tree olddecl, newdecl;
3554 #ifdef MERGE_MACHINE_DECL_ATTRIBUTES
3555 return MERGE_MACHINE_DECL_ATTRIBUTES (olddecl, newdecl);
3557 return merge_attributes (DECL_MACHINE_ATTRIBUTES (olddecl),
3558 DECL_MACHINE_ATTRIBUTES (newdecl));
3562 /* Return a type like TYPE except that its TYPE_READONLY is CONSTP
3563 and its TYPE_VOLATILE is VOLATILEP.
3565 Such variant types already made are recorded so that duplicates
3568 A variant types should never be used as the type of an expression.
3569 Always copy the variant information into the TREE_READONLY
3570 and TREE_THIS_VOLATILE of the expression, and then give the expression
3571 as its type the "main variant", the variant whose TYPE_READONLY
3572 and TYPE_VOLATILE are zero. Use TYPE_MAIN_VARIANT to find the
3576 build_type_variant (type, constp, volatilep)
3578 int constp, volatilep;
3582 /* Treat any nonzero argument as 1. */
3584 volatilep = !!volatilep;
3586 /* Search the chain of variants to see if there is already one there just
3587 like the one we need to have. If so, use that existing one. We must
3588 preserve the TYPE_NAME, since there is code that depends on this. */
3590 for (t = TYPE_MAIN_VARIANT (type); t; t = TYPE_NEXT_VARIANT (t))
3591 if (constp == TYPE_READONLY (t) && volatilep == TYPE_VOLATILE (t)
3592 && TYPE_NAME (t) == TYPE_NAME (type))
3595 /* We need a new one. */
3597 t = build_type_copy (type);
3598 TYPE_READONLY (t) = constp;
3599 TYPE_VOLATILE (t) = volatilep;
3604 /* Create a new variant of TYPE, equivalent but distinct.
3605 This is so the caller can modify it. */
3608 build_type_copy (type)
3611 register tree t, m = TYPE_MAIN_VARIANT (type);
3612 register struct obstack *ambient_obstack = current_obstack;
3614 current_obstack = TYPE_OBSTACK (type);
3615 t = copy_node (type);
3616 current_obstack = ambient_obstack;
3618 TYPE_POINTER_TO (t) = 0;
3619 TYPE_REFERENCE_TO (t) = 0;
3621 /* Add this type to the chain of variants of TYPE. */
3622 TYPE_NEXT_VARIANT (t) = TYPE_NEXT_VARIANT (m);
3623 TYPE_NEXT_VARIANT (m) = t;
3628 /* Hashing of types so that we don't make duplicates.
3629 The entry point is `type_hash_canon'. */
3631 /* Each hash table slot is a bucket containing a chain
3632 of these structures. */
3636 struct type_hash *next; /* Next structure in the bucket. */
3637 int hashcode; /* Hash code of this type. */
3638 tree type; /* The type recorded here. */
3641 /* Now here is the hash table. When recording a type, it is added
3642 to the slot whose index is the hash code mod the table size.
3643 Note that the hash table is used for several kinds of types
3644 (function types, array types and array index range types, for now).
3645 While all these live in the same table, they are completely independent,
3646 and the hash code is computed differently for each of these. */
3648 #define TYPE_HASH_SIZE 59
3649 struct type_hash *type_hash_table[TYPE_HASH_SIZE];
3651 /* Compute a hash code for a list of types (chain of TREE_LIST nodes
3652 with types in the TREE_VALUE slots), by adding the hash codes
3653 of the individual types. */
3656 type_hash_list (list)
3659 register int hashcode;
3661 for (hashcode = 0, tail = list; tail; tail = TREE_CHAIN (tail))
3662 hashcode += TYPE_HASH (TREE_VALUE (tail));
3666 /* Look in the type hash table for a type isomorphic to TYPE.
3667 If one is found, return it. Otherwise return 0. */
3670 type_hash_lookup (hashcode, type)
3674 register struct type_hash *h;
3675 for (h = type_hash_table[hashcode % TYPE_HASH_SIZE]; h; h = h->next)
3676 if (h->hashcode == hashcode
3677 && TREE_CODE (h->type) == TREE_CODE (type)
3678 && TREE_TYPE (h->type) == TREE_TYPE (type)
3679 && attribute_list_equal (TYPE_ATTRIBUTES (h->type),
3680 TYPE_ATTRIBUTES (type))
3681 && (TYPE_MAX_VALUE (h->type) == TYPE_MAX_VALUE (type)
3682 || tree_int_cst_equal (TYPE_MAX_VALUE (h->type),
3683 TYPE_MAX_VALUE (type)))
3684 && (TYPE_MIN_VALUE (h->type) == TYPE_MIN_VALUE (type)
3685 || tree_int_cst_equal (TYPE_MIN_VALUE (h->type),
3686 TYPE_MIN_VALUE (type)))
3687 /* Note that TYPE_DOMAIN is TYPE_ARG_TYPES for FUNCTION_TYPE. */
3688 && (TYPE_DOMAIN (h->type) == TYPE_DOMAIN (type)
3689 || (TYPE_DOMAIN (h->type)
3690 && TREE_CODE (TYPE_DOMAIN (h->type)) == TREE_LIST
3691 && TYPE_DOMAIN (type)
3692 && TREE_CODE (TYPE_DOMAIN (type)) == TREE_LIST
3693 && type_list_equal (TYPE_DOMAIN (h->type),
3694 TYPE_DOMAIN (type)))))
3699 /* Add an entry to the type-hash-table
3700 for a type TYPE whose hash code is HASHCODE. */
3703 type_hash_add (hashcode, type)
3707 register struct type_hash *h;
3709 h = (struct type_hash *) oballoc (sizeof (struct type_hash));
3710 h->hashcode = hashcode;
3712 h->next = type_hash_table[hashcode % TYPE_HASH_SIZE];
3713 type_hash_table[hashcode % TYPE_HASH_SIZE] = h;
3716 /* Given TYPE, and HASHCODE its hash code, return the canonical
3717 object for an identical type if one already exists.
3718 Otherwise, return TYPE, and record it as the canonical object
3719 if it is a permanent object.
3721 To use this function, first create a type of the sort you want.
3722 Then compute its hash code from the fields of the type that
3723 make it different from other similar types.
3724 Then call this function and use the value.
3725 This function frees the type you pass in if it is a duplicate. */
3727 /* Set to 1 to debug without canonicalization. Never set by program. */
3728 int debug_no_type_hash = 0;
3731 type_hash_canon (hashcode, type)
3737 if (debug_no_type_hash)
3740 t1 = type_hash_lookup (hashcode, type);
3743 obstack_free (TYPE_OBSTACK (type), type);
3744 #ifdef GATHER_STATISTICS
3745 tree_node_counts[(int)t_kind]--;
3746 tree_node_sizes[(int)t_kind] -= sizeof (struct tree_type);
3751 /* If this is a permanent type, record it for later reuse. */
3752 if (TREE_PERMANENT (type))
3753 type_hash_add (hashcode, type);
3758 /* Compute a hash code for a list of attributes (chain of TREE_LIST nodes
3759 with names in the TREE_PURPOSE slots and args in the TREE_VALUE slots),
3760 by adding the hash codes of the individual attributes. */
3763 attribute_hash_list (list)
3766 register int hashcode;
3768 for (hashcode = 0, tail = list; tail; tail = TREE_CHAIN (tail))
3769 /* ??? Do we want to add in TREE_VALUE too? */
3770 hashcode += TYPE_HASH (TREE_PURPOSE (tail));
3774 /* Given two lists of attributes, return true if list l2 is
3775 equivalent to l1. */
3778 attribute_list_equal (l1, l2)
3781 return attribute_list_contained (l1, l2)
3782 && attribute_list_contained (l2, l1);
3785 /* Given two lists of attributes, return true if list L2 is
3786 completely contained within L1. */
3787 /* ??? This would be faster if attribute names were stored in a canonicalized
3788 form. Otherwise, if L1 uses `foo' and L2 uses `__foo__', the long method
3789 must be used to show these elements are equivalent (which they are). */
3790 /* ??? It's not clear that attributes with arguments will always be handled
3794 attribute_list_contained (l1, l2)
3797 register tree t1, t2;
3799 /* First check the obvious, maybe the lists are identical. */
3803 /* Maybe the lists are similar. */
3804 for (t1 = l1, t2 = l2;
3806 && TREE_PURPOSE (t1) == TREE_PURPOSE (t2)
3807 && TREE_VALUE (t1) == TREE_VALUE (t2);
3808 t1 = TREE_CHAIN (t1), t2 = TREE_CHAIN (t2));
3810 /* Maybe the lists are equal. */
3811 if (t1 == 0 && t2 == 0)
3814 for (; t2; t2 = TREE_CHAIN (t2))
3817 = lookup_attribute (IDENTIFIER_POINTER (TREE_PURPOSE (t2)), l1);
3819 if (attr == NULL_TREE)
3821 if (simple_cst_equal (TREE_VALUE (t2), TREE_VALUE (attr)) != 1)
3828 /* Given two lists of types
3829 (chains of TREE_LIST nodes with types in the TREE_VALUE slots)
3830 return 1 if the lists contain the same types in the same order.
3831 Also, the TREE_PURPOSEs must match. */
3834 type_list_equal (l1, l2)
3837 register tree t1, t2;
3839 for (t1 = l1, t2 = l2; t1 && t2; t1 = TREE_CHAIN (t1), t2 = TREE_CHAIN (t2))
3840 if (TREE_VALUE (t1) != TREE_VALUE (t2)
3841 || (TREE_PURPOSE (t1) != TREE_PURPOSE (t2)
3842 && ! (1 == simple_cst_equal (TREE_PURPOSE (t1), TREE_PURPOSE (t2))
3843 && (TREE_TYPE (TREE_PURPOSE (t1))
3844 == TREE_TYPE (TREE_PURPOSE (t2))))))
3850 /* Nonzero if integer constants T1 and T2
3851 represent the same constant value. */
3854 tree_int_cst_equal (t1, t2)
3859 if (t1 == 0 || t2 == 0)
3861 if (TREE_CODE (t1) == INTEGER_CST
3862 && TREE_CODE (t2) == INTEGER_CST
3863 && TREE_INT_CST_LOW (t1) == TREE_INT_CST_LOW (t2)
3864 && TREE_INT_CST_HIGH (t1) == TREE_INT_CST_HIGH (t2))
3869 /* Nonzero if integer constants T1 and T2 represent values that satisfy <.
3870 The precise way of comparison depends on their data type. */
3873 tree_int_cst_lt (t1, t2)
3879 if (!TREE_UNSIGNED (TREE_TYPE (t1)))
3880 return INT_CST_LT (t1, t2);
3881 return INT_CST_LT_UNSIGNED (t1, t2);
3884 /* Return an indication of the sign of the integer constant T.
3885 The return value is -1 if T < 0, 0 if T == 0, and 1 if T > 0.
3886 Note that -1 will never be returned it T's type is unsigned. */
3889 tree_int_cst_sgn (t)
3892 if (TREE_INT_CST_LOW (t) == 0 && TREE_INT_CST_HIGH (t) == 0)
3894 else if (TREE_UNSIGNED (TREE_TYPE (t)))
3896 else if (TREE_INT_CST_HIGH (t) < 0)
3902 /* Compare two constructor-element-type constants. Return 1 if the lists
3903 are known to be equal; otherwise return 0. */
3906 simple_cst_list_equal (l1, l2)
3909 while (l1 != NULL_TREE && l2 != NULL_TREE)
3911 if (simple_cst_equal (TREE_VALUE (l1), TREE_VALUE (l2)) != 1)
3914 l1 = TREE_CHAIN (l1);
3915 l2 = TREE_CHAIN (l2);
3921 /* Return truthvalue of whether T1 is the same tree structure as T2.
3922 Return 1 if they are the same.
3923 Return 0 if they are understandably different.
3924 Return -1 if either contains tree structure not understood by
3928 simple_cst_equal (t1, t2)
3931 register enum tree_code code1, code2;
3936 if (t1 == 0 || t2 == 0)
3939 code1 = TREE_CODE (t1);
3940 code2 = TREE_CODE (t2);
3942 if (code1 == NOP_EXPR || code1 == CONVERT_EXPR || code1 == NON_LVALUE_EXPR)
3943 if (code2 == NOP_EXPR || code2 == CONVERT_EXPR || code2 == NON_LVALUE_EXPR)
3944 return simple_cst_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
3946 return simple_cst_equal (TREE_OPERAND (t1, 0), t2);
3947 else if (code2 == NOP_EXPR || code2 == CONVERT_EXPR
3948 || code2 == NON_LVALUE_EXPR)
3949 return simple_cst_equal (t1, TREE_OPERAND (t2, 0));
3957 return TREE_INT_CST_LOW (t1) == TREE_INT_CST_LOW (t2)
3958 && TREE_INT_CST_HIGH (t1) == TREE_INT_CST_HIGH (t2);
3961 return REAL_VALUES_IDENTICAL (TREE_REAL_CST (t1), TREE_REAL_CST (t2));
3964 return TREE_STRING_LENGTH (t1) == TREE_STRING_LENGTH (t2)
3965 && !bcmp (TREE_STRING_POINTER (t1), TREE_STRING_POINTER (t2),
3966 TREE_STRING_LENGTH (t1));
3972 return simple_cst_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
3975 cmp = simple_cst_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
3978 return simple_cst_list_equal (TREE_OPERAND (t1, 1), TREE_OPERAND (t2, 1));
3981 /* Special case: if either target is an unallocated VAR_DECL,
3982 it means that it's going to be unified with whatever the
3983 TARGET_EXPR is really supposed to initialize, so treat it
3984 as being equivalent to anything. */
3985 if ((TREE_CODE (TREE_OPERAND (t1, 0)) == VAR_DECL
3986 && DECL_NAME (TREE_OPERAND (t1, 0)) == NULL_TREE
3987 && DECL_RTL (TREE_OPERAND (t1, 0)) == 0)
3988 || (TREE_CODE (TREE_OPERAND (t2, 0)) == VAR_DECL
3989 && DECL_NAME (TREE_OPERAND (t2, 0)) == NULL_TREE
3990 && DECL_RTL (TREE_OPERAND (t2, 0)) == 0))
3993 cmp = simple_cst_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
3996 return simple_cst_equal (TREE_OPERAND (t1, 1), TREE_OPERAND (t2, 1));
3998 case WITH_CLEANUP_EXPR:
3999 cmp = simple_cst_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
4002 return simple_cst_equal (TREE_OPERAND (t1, 2), TREE_OPERAND (t1, 2));
4005 if (TREE_OPERAND (t1, 1) == TREE_OPERAND (t2, 1))
4006 return simple_cst_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
4019 /* This general rule works for most tree codes. All exceptions should be
4020 handled above. If this is a language-specific tree code, we can't
4021 trust what might be in the operand, so say we don't know
4023 if ((int) code1 >= (int) LAST_AND_UNUSED_TREE_CODE)
4026 switch (TREE_CODE_CLASS (code1))
4036 for (i=0; i<tree_code_length[(int) code1]; ++i)
4038 cmp = simple_cst_equal (TREE_OPERAND (t1, i), TREE_OPERAND (t2, i));
4049 /* Constructors for pointer, array and function types.
4050 (RECORD_TYPE, UNION_TYPE and ENUMERAL_TYPE nodes are
4051 constructed by language-dependent code, not here.) */
4053 /* Construct, lay out and return the type of pointers to TO_TYPE.
4054 If such a type has already been constructed, reuse it. */
4057 build_pointer_type (to_type)
4060 register tree t = TYPE_POINTER_TO (to_type);
4062 /* First, if we already have a type for pointers to TO_TYPE, use it. */
4067 /* We need a new one. Put this in the same obstack as TO_TYPE. */
4068 push_obstacks (TYPE_OBSTACK (to_type), TYPE_OBSTACK (to_type));
4069 t = make_node (POINTER_TYPE);
4072 TREE_TYPE (t) = to_type;
4074 /* Record this type as the pointer to TO_TYPE. */
4075 TYPE_POINTER_TO (to_type) = t;
4077 /* Lay out the type. This function has many callers that are concerned
4078 with expression-construction, and this simplifies them all.
4079 Also, it guarantees the TYPE_SIZE is in the same obstack as the type. */
4085 /* Create a type of integers to be the TYPE_DOMAIN of an ARRAY_TYPE.
4086 MAXVAL should be the maximum value in the domain
4087 (one less than the length of the array).
4089 The maximum value that MAXVAL can have is INT_MAX for a HOST_WIDE_INT.
4090 We don't enforce this limit, that is up to caller (e.g. language front end).
4091 The limit exists because the result is a signed type and we don't handle
4092 sizes that use more than one HOST_WIDE_INT. */
4095 build_index_type (maxval)
4098 register tree itype = make_node (INTEGER_TYPE);
4100 TYPE_PRECISION (itype) = TYPE_PRECISION (sizetype);
4101 TYPE_MIN_VALUE (itype) = size_zero_node;
4103 push_obstacks (TYPE_OBSTACK (itype), TYPE_OBSTACK (itype));
4104 TYPE_MAX_VALUE (itype) = convert (sizetype, maxval);
4107 TYPE_MODE (itype) = TYPE_MODE (sizetype);
4108 TYPE_SIZE (itype) = TYPE_SIZE (sizetype);
4109 TYPE_ALIGN (itype) = TYPE_ALIGN (sizetype);
4110 if (TREE_CODE (maxval) == INTEGER_CST)
4112 int maxint = (int) TREE_INT_CST_LOW (maxval);
4113 /* If the domain should be empty, make sure the maxval
4114 remains -1 and is not spoiled by truncation. */
4115 if (INT_CST_LT (maxval, integer_zero_node))
4117 TYPE_MAX_VALUE (itype) = build_int_2 (-1, -1);
4118 TREE_TYPE (TYPE_MAX_VALUE (itype)) = sizetype;
4120 return type_hash_canon (maxint < 0 ? ~maxint : maxint, itype);
4126 /* Create a range of some discrete type TYPE (an INTEGER_TYPE,
4127 ENUMERAL_TYPE, BOOLEAN_TYPE, or CHAR_TYPE), with
4128 low bound LOWVAL and high bound HIGHVAL.
4129 if TYPE==NULL_TREE, sizetype is used. */
4132 build_range_type (type, lowval, highval)
4133 tree type, lowval, highval;
4135 register tree itype = make_node (INTEGER_TYPE);
4137 TREE_TYPE (itype) = type;
4138 if (type == NULL_TREE)
4141 push_obstacks (TYPE_OBSTACK (itype), TYPE_OBSTACK (itype));
4142 TYPE_MIN_VALUE (itype) = convert (type, lowval);
4143 TYPE_MAX_VALUE (itype) = highval ? convert (type, highval) : NULL;
4146 TYPE_PRECISION (itype) = TYPE_PRECISION (type);
4147 TYPE_MODE (itype) = TYPE_MODE (type);
4148 TYPE_SIZE (itype) = TYPE_SIZE (type);
4149 TYPE_ALIGN (itype) = TYPE_ALIGN (type);
4150 if (TREE_CODE (lowval) == INTEGER_CST)
4152 HOST_WIDE_INT lowint, highint;
4155 lowint = TREE_INT_CST_LOW (lowval);
4156 if (highval && TREE_CODE (highval) == INTEGER_CST)
4157 highint = TREE_INT_CST_LOW (highval);
4159 highint = (~(unsigned HOST_WIDE_INT)0) >> 1;
4161 maxint = (int) (highint - lowint);
4162 return type_hash_canon (maxint < 0 ? ~maxint : maxint, itype);
4168 /* Just like build_index_type, but takes lowval and highval instead
4169 of just highval (maxval). */
4172 build_index_2_type (lowval,highval)
4173 tree lowval, highval;
4175 return build_range_type (NULL_TREE, lowval, highval);
4178 /* Return nonzero iff ITYPE1 and ITYPE2 are equal (in the LISP sense).
4179 Needed because when index types are not hashed, equal index types
4180 built at different times appear distinct, even though structurally,
4184 index_type_equal (itype1, itype2)
4185 tree itype1, itype2;
4187 if (TREE_CODE (itype1) != TREE_CODE (itype2))
4189 if (TREE_CODE (itype1) == INTEGER_TYPE)
4191 if (TYPE_PRECISION (itype1) != TYPE_PRECISION (itype2)
4192 || TYPE_MODE (itype1) != TYPE_MODE (itype2)
4193 || simple_cst_equal (TYPE_SIZE (itype1), TYPE_SIZE (itype2)) != 1
4194 || TYPE_ALIGN (itype1) != TYPE_ALIGN (itype2))
4196 if (1 == simple_cst_equal (TYPE_MIN_VALUE (itype1),
4197 TYPE_MIN_VALUE (itype2))
4198 && 1 == simple_cst_equal (TYPE_MAX_VALUE (itype1),
4199 TYPE_MAX_VALUE (itype2)))
4206 /* Construct, lay out and return the type of arrays of elements with ELT_TYPE
4207 and number of elements specified by the range of values of INDEX_TYPE.
4208 If such a type has already been constructed, reuse it. */
4211 build_array_type (elt_type, index_type)
4212 tree elt_type, index_type;
4217 if (TREE_CODE (elt_type) == FUNCTION_TYPE)
4219 error ("arrays of functions are not meaningful");
4220 elt_type = integer_type_node;
4223 /* Make sure TYPE_POINTER_TO (elt_type) is filled in. */
4224 build_pointer_type (elt_type);
4226 /* Allocate the array after the pointer type,
4227 in case we free it in type_hash_canon. */
4228 t = make_node (ARRAY_TYPE);
4229 TREE_TYPE (t) = elt_type;
4230 TYPE_DOMAIN (t) = index_type;
4232 if (index_type == 0)
4237 hashcode = TYPE_HASH (elt_type) + TYPE_HASH (index_type);
4238 t = type_hash_canon (hashcode, t);
4240 if (TYPE_SIZE (t) == 0)
4245 /* Return the TYPE of the elements comprising
4246 the innermost dimension of ARRAY. */
4249 get_inner_array_type (array)
4252 tree type = TREE_TYPE (array);
4254 while (TREE_CODE (type) == ARRAY_TYPE)
4255 type = TREE_TYPE (type);
4260 /* Construct, lay out and return
4261 the type of functions returning type VALUE_TYPE
4262 given arguments of types ARG_TYPES.
4263 ARG_TYPES is a chain of TREE_LIST nodes whose TREE_VALUEs
4264 are data type nodes for the arguments of the function.
4265 If such a type has already been constructed, reuse it. */
4268 build_function_type (value_type, arg_types)
4269 tree value_type, arg_types;
4274 if (TREE_CODE (value_type) == FUNCTION_TYPE)
4276 error ("function return type cannot be function");
4277 value_type = integer_type_node;
4280 /* Make a node of the sort we want. */
4281 t = make_node (FUNCTION_TYPE);
4282 TREE_TYPE (t) = value_type;
4283 TYPE_ARG_TYPES (t) = arg_types;
4285 /* If we already have such a type, use the old one and free this one. */
4286 hashcode = TYPE_HASH (value_type) + type_hash_list (arg_types);
4287 t = type_hash_canon (hashcode, t);
4289 if (TYPE_SIZE (t) == 0)
4294 /* Build the node for the type of references-to-TO_TYPE. */
4297 build_reference_type (to_type)
4300 register tree t = TYPE_REFERENCE_TO (to_type);
4302 /* First, if we already have a type for pointers to TO_TYPE, use it. */
4307 /* We need a new one. Put this in the same obstack as TO_TYPE. */
4308 push_obstacks (TYPE_OBSTACK (to_type), TYPE_OBSTACK (to_type));
4309 t = make_node (REFERENCE_TYPE);
4312 TREE_TYPE (t) = to_type;
4314 /* Record this type as the pointer to TO_TYPE. */
4315 TYPE_REFERENCE_TO (to_type) = t;
4322 /* Construct, lay out and return the type of methods belonging to class
4323 BASETYPE and whose arguments and values are described by TYPE.
4324 If that type exists already, reuse it.
4325 TYPE must be a FUNCTION_TYPE node. */
4328 build_method_type (basetype, type)
4329 tree basetype, type;
4334 /* Make a node of the sort we want. */
4335 t = make_node (METHOD_TYPE);
4337 if (TREE_CODE (type) != FUNCTION_TYPE)
4340 TYPE_METHOD_BASETYPE (t) = TYPE_MAIN_VARIANT (basetype);
4341 TREE_TYPE (t) = TREE_TYPE (type);
4343 /* The actual arglist for this function includes a "hidden" argument
4344 which is "this". Put it into the list of argument types. */
4347 = tree_cons (NULL_TREE,
4348 build_pointer_type (basetype), TYPE_ARG_TYPES (type));
4350 /* If we already have such a type, use the old one and free this one. */
4351 hashcode = TYPE_HASH (basetype) + TYPE_HASH (type);
4352 t = type_hash_canon (hashcode, t);
4354 if (TYPE_SIZE (t) == 0)
4360 /* Construct, lay out and return the type of offsets to a value
4361 of type TYPE, within an object of type BASETYPE.
4362 If a suitable offset type exists already, reuse it. */
4365 build_offset_type (basetype, type)
4366 tree basetype, type;
4371 /* Make a node of the sort we want. */
4372 t = make_node (OFFSET_TYPE);
4374 TYPE_OFFSET_BASETYPE (t) = TYPE_MAIN_VARIANT (basetype);
4375 TREE_TYPE (t) = type;
4377 /* If we already have such a type, use the old one and free this one. */
4378 hashcode = TYPE_HASH (basetype) + TYPE_HASH (type);
4379 t = type_hash_canon (hashcode, t);
4381 if (TYPE_SIZE (t) == 0)
4387 /* Create a complex type whose components are COMPONENT_TYPE. */
4390 build_complex_type (component_type)
4391 tree component_type;
4396 /* Make a node of the sort we want. */
4397 t = make_node (COMPLEX_TYPE);
4399 TREE_TYPE (t) = TYPE_MAIN_VARIANT (component_type);
4400 TYPE_VOLATILE (t) = TYPE_VOLATILE (component_type);
4401 TYPE_READONLY (t) = TYPE_READONLY (component_type);
4403 /* If we already have such a type, use the old one and free this one. */
4404 hashcode = TYPE_HASH (component_type);
4405 t = type_hash_canon (hashcode, t);
4407 if (TYPE_SIZE (t) == 0)
4413 /* Return OP, stripped of any conversions to wider types as much as is safe.
4414 Converting the value back to OP's type makes a value equivalent to OP.
4416 If FOR_TYPE is nonzero, we return a value which, if converted to
4417 type FOR_TYPE, would be equivalent to converting OP to type FOR_TYPE.
4419 If FOR_TYPE is nonzero, unaligned bit-field references may be changed to the
4420 narrowest type that can hold the value, even if they don't exactly fit.
4421 Otherwise, bit-field references are changed to a narrower type
4422 only if they can be fetched directly from memory in that type.
4424 OP must have integer, real or enumeral type. Pointers are not allowed!
4426 There are some cases where the obvious value we could return
4427 would regenerate to OP if converted to OP's type,
4428 but would not extend like OP to wider types.
4429 If FOR_TYPE indicates such extension is contemplated, we eschew such values.
4430 For example, if OP is (unsigned short)(signed char)-1,
4431 we avoid returning (signed char)-1 if FOR_TYPE is int,
4432 even though extending that to an unsigned short would regenerate OP,
4433 since the result of extending (signed char)-1 to (int)
4434 is different from (int) OP. */
4437 get_unwidened (op, for_type)
4441 /* Set UNS initially if converting OP to FOR_TYPE is a zero-extension. */
4442 register tree type = TREE_TYPE (op);
4443 register unsigned final_prec
4444 = TYPE_PRECISION (for_type != 0 ? for_type : type);
4446 = (for_type != 0 && for_type != type
4447 && final_prec > TYPE_PRECISION (type)
4448 && TREE_UNSIGNED (type));
4449 register tree win = op;
4451 while (TREE_CODE (op) == NOP_EXPR)
4453 register int bitschange
4454 = TYPE_PRECISION (TREE_TYPE (op))
4455 - TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (op, 0)));
4457 /* Truncations are many-one so cannot be removed.
4458 Unless we are later going to truncate down even farther. */
4460 && final_prec > TYPE_PRECISION (TREE_TYPE (op)))
4463 /* See what's inside this conversion. If we decide to strip it,
4465 op = TREE_OPERAND (op, 0);
4467 /* If we have not stripped any zero-extensions (uns is 0),
4468 we can strip any kind of extension.
4469 If we have previously stripped a zero-extension,
4470 only zero-extensions can safely be stripped.
4471 Any extension can be stripped if the bits it would produce
4472 are all going to be discarded later by truncating to FOR_TYPE. */
4476 if (! uns || final_prec <= TYPE_PRECISION (TREE_TYPE (op)))
4478 /* TREE_UNSIGNED says whether this is a zero-extension.
4479 Let's avoid computing it if it does not affect WIN
4480 and if UNS will not be needed again. */
4481 if ((uns || TREE_CODE (op) == NOP_EXPR)
4482 && TREE_UNSIGNED (TREE_TYPE (op)))
4490 if (TREE_CODE (op) == COMPONENT_REF
4491 /* Since type_for_size always gives an integer type. */
4492 && TREE_CODE (type) != REAL_TYPE
4493 /* Don't crash if field not laid out yet. */
4494 && DECL_SIZE (TREE_OPERAND (op, 1)) != 0)
4496 unsigned innerprec = TREE_INT_CST_LOW (DECL_SIZE (TREE_OPERAND (op, 1)));
4497 type = type_for_size (innerprec, TREE_UNSIGNED (TREE_OPERAND (op, 1)));
4499 /* We can get this structure field in the narrowest type it fits in.
4500 If FOR_TYPE is 0, do this only for a field that matches the
4501 narrower type exactly and is aligned for it
4502 The resulting extension to its nominal type (a fullword type)
4503 must fit the same conditions as for other extensions. */
4505 if (innerprec < TYPE_PRECISION (TREE_TYPE (op))
4506 && (for_type || ! DECL_BIT_FIELD (TREE_OPERAND (op, 1)))
4507 && (! uns || final_prec <= innerprec
4508 || TREE_UNSIGNED (TREE_OPERAND (op, 1)))
4511 win = build (COMPONENT_REF, type, TREE_OPERAND (op, 0),
4512 TREE_OPERAND (op, 1));
4513 TREE_SIDE_EFFECTS (win) = TREE_SIDE_EFFECTS (op);
4514 TREE_THIS_VOLATILE (win) = TREE_THIS_VOLATILE (op);
4515 TREE_RAISES (win) = TREE_RAISES (op);
4521 /* Return OP or a simpler expression for a narrower value
4522 which can be sign-extended or zero-extended to give back OP.
4523 Store in *UNSIGNEDP_PTR either 1 if the value should be zero-extended
4524 or 0 if the value should be sign-extended. */
4527 get_narrower (op, unsignedp_ptr)
4531 register int uns = 0;
4533 register tree win = op;
4535 while (TREE_CODE (op) == NOP_EXPR)
4537 register int bitschange
4538 = TYPE_PRECISION (TREE_TYPE (op))
4539 - TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (op, 0)));
4541 /* Truncations are many-one so cannot be removed. */
4545 /* See what's inside this conversion. If we decide to strip it,
4547 op = TREE_OPERAND (op, 0);
4551 /* An extension: the outermost one can be stripped,
4552 but remember whether it is zero or sign extension. */
4554 uns = TREE_UNSIGNED (TREE_TYPE (op));
4555 /* Otherwise, if a sign extension has been stripped,
4556 only sign extensions can now be stripped;
4557 if a zero extension has been stripped, only zero-extensions. */
4558 else if (uns != TREE_UNSIGNED (TREE_TYPE (op)))
4562 else /* bitschange == 0 */
4564 /* A change in nominal type can always be stripped, but we must
4565 preserve the unsignedness. */
4567 uns = TREE_UNSIGNED (TREE_TYPE (op));
4574 if (TREE_CODE (op) == COMPONENT_REF
4575 /* Since type_for_size always gives an integer type. */
4576 && TREE_CODE (TREE_TYPE (op)) != REAL_TYPE)
4578 unsigned innerprec = TREE_INT_CST_LOW (DECL_SIZE (TREE_OPERAND (op, 1)));
4579 tree type = type_for_size (innerprec, TREE_UNSIGNED (op));
4581 /* We can get this structure field in a narrower type that fits it,
4582 but the resulting extension to its nominal type (a fullword type)
4583 must satisfy the same conditions as for other extensions.
4585 Do this only for fields that are aligned (not bit-fields),
4586 because when bit-field insns will be used there is no
4587 advantage in doing this. */
4589 if (innerprec < TYPE_PRECISION (TREE_TYPE (op))
4590 && ! DECL_BIT_FIELD (TREE_OPERAND (op, 1))
4591 && (first || uns == TREE_UNSIGNED (TREE_OPERAND (op, 1)))
4595 uns = TREE_UNSIGNED (TREE_OPERAND (op, 1));
4596 win = build (COMPONENT_REF, type, TREE_OPERAND (op, 0),
4597 TREE_OPERAND (op, 1));
4598 TREE_SIDE_EFFECTS (win) = TREE_SIDE_EFFECTS (op);
4599 TREE_THIS_VOLATILE (win) = TREE_THIS_VOLATILE (op);
4600 TREE_RAISES (win) = TREE_RAISES (op);
4603 *unsignedp_ptr = uns;
4607 /* Nonzero if integer constant C has a value that is permissible
4608 for type TYPE (an INTEGER_TYPE). */
4611 int_fits_type_p (c, type)
4614 if (TREE_UNSIGNED (type))
4615 return (! (TREE_CODE (TYPE_MAX_VALUE (type)) == INTEGER_CST
4616 && INT_CST_LT_UNSIGNED (TYPE_MAX_VALUE (type), c))
4617 && ! (TREE_CODE (TYPE_MIN_VALUE (type)) == INTEGER_CST
4618 && INT_CST_LT_UNSIGNED (c, TYPE_MIN_VALUE (type)))
4619 /* Negative ints never fit unsigned types. */
4620 && ! (TREE_INT_CST_HIGH (c) < 0
4621 && ! TREE_UNSIGNED (TREE_TYPE (c))));
4623 return (! (TREE_CODE (TYPE_MAX_VALUE (type)) == INTEGER_CST
4624 && INT_CST_LT (TYPE_MAX_VALUE (type), c))
4625 && ! (TREE_CODE (TYPE_MIN_VALUE (type)) == INTEGER_CST
4626 && INT_CST_LT (c, TYPE_MIN_VALUE (type)))
4627 /* Unsigned ints with top bit set never fit signed types. */
4628 && ! (TREE_INT_CST_HIGH (c) < 0
4629 && TREE_UNSIGNED (TREE_TYPE (c))));
4632 /* Return the innermost context enclosing DECL that is
4633 a FUNCTION_DECL, or zero if none. */
4636 decl_function_context (decl)
4641 if (TREE_CODE (decl) == ERROR_MARK)
4644 if (TREE_CODE (decl) == SAVE_EXPR)
4645 context = SAVE_EXPR_CONTEXT (decl);
4647 context = DECL_CONTEXT (decl);
4649 while (context && TREE_CODE (context) != FUNCTION_DECL)
4651 if (TREE_CODE_CLASS (TREE_CODE (context)) == 't')
4652 context = TYPE_CONTEXT (context);
4653 else if (TREE_CODE_CLASS (TREE_CODE (context)) == 'd')
4654 context = DECL_CONTEXT (context);
4655 else if (TREE_CODE (context) == BLOCK)
4656 context = BLOCK_SUPERCONTEXT (context);
4658 /* Unhandled CONTEXT !? */
4665 /* Return the innermost context enclosing DECL that is
4666 a RECORD_TYPE, UNION_TYPE or QUAL_UNION_TYPE, or zero if none.
4667 TYPE_DECLs and FUNCTION_DECLs are transparent to this function. */
4670 decl_type_context (decl)
4673 tree context = DECL_CONTEXT (decl);
4677 if (TREE_CODE (context) == RECORD_TYPE
4678 || TREE_CODE (context) == UNION_TYPE
4679 || TREE_CODE (context) == QUAL_UNION_TYPE)
4681 if (TREE_CODE (context) == TYPE_DECL
4682 || TREE_CODE (context) == FUNCTION_DECL)
4683 context = DECL_CONTEXT (context);
4684 else if (TREE_CODE (context) == BLOCK)
4685 context = BLOCK_SUPERCONTEXT (context);
4687 /* Unhandled CONTEXT!? */
4693 /* Print debugging information about the size of the
4694 toplev_inline_obstacks. */
4697 print_inline_obstack_statistics ()
4699 struct simple_obstack_stack *current = toplev_inline_obstacks;
4704 for (; current; current = current->next, ++n_obstacks)
4706 struct obstack *o = current->obstack;
4707 struct _obstack_chunk *chunk = o->chunk;
4709 n_alloc += o->next_free - chunk->contents;
4710 chunk = chunk->prev;
4712 for (; chunk; chunk = chunk->prev, ++n_chunks)
4713 n_alloc += chunk->limit - &chunk->contents[0];
4715 fprintf (stderr, "inline obstacks: %d obstacks, %d bytes, %d chunks\n",
4716 n_obstacks, n_alloc, n_chunks);
4719 /* Print debugging information about the obstack O, named STR. */
4722 print_obstack_statistics (str, o)
4726 struct _obstack_chunk *chunk = o->chunk;
4730 n_alloc += o->next_free - chunk->contents;
4731 chunk = chunk->prev;
4735 n_alloc += chunk->limit - &chunk->contents[0];
4736 chunk = chunk->prev;
4738 fprintf (stderr, "obstack %s: %u bytes, %d chunks\n",
4739 str, n_alloc, n_chunks);
4742 /* Print debugging information about tree nodes generated during the compile,
4743 and any language-specific information. */
4746 dump_tree_statistics ()
4748 #ifdef GATHER_STATISTICS
4750 int total_nodes, total_bytes;
4753 fprintf (stderr, "\n??? tree nodes created\n\n");
4754 #ifdef GATHER_STATISTICS
4755 fprintf (stderr, "Kind Nodes Bytes\n");
4756 fprintf (stderr, "-------------------------------------\n");
4757 total_nodes = total_bytes = 0;
4758 for (i = 0; i < (int) all_kinds; i++)
4760 fprintf (stderr, "%-20s %6d %9d\n", tree_node_kind_names[i],
4761 tree_node_counts[i], tree_node_sizes[i]);
4762 total_nodes += tree_node_counts[i];
4763 total_bytes += tree_node_sizes[i];
4765 fprintf (stderr, "%-20s %9d\n", "identifier names", id_string_size);
4766 fprintf (stderr, "-------------------------------------\n");
4767 fprintf (stderr, "%-20s %6d %9d\n", "Total", total_nodes, total_bytes);
4768 fprintf (stderr, "-------------------------------------\n");
4770 fprintf (stderr, "(No per-node statistics)\n");
4772 print_obstack_statistics ("permanent_obstack", &permanent_obstack);
4773 print_obstack_statistics ("maybepermanent_obstack", &maybepermanent_obstack);
4774 print_obstack_statistics ("temporary_obstack", &temporary_obstack);
4775 print_obstack_statistics ("momentary_obstack", &momentary_obstack);
4776 print_obstack_statistics ("temp_decl_obstack", &temp_decl_obstack);
4777 print_inline_obstack_statistics ();
4778 print_lang_statistics ();
4781 #define FILE_FUNCTION_PREFIX_LEN 9
4783 #ifndef NO_DOLLAR_IN_LABEL
4784 #define FILE_FUNCTION_FORMAT "_GLOBAL_$D$%s"
4785 #else /* NO_DOLLAR_IN_LABEL */
4786 #ifndef NO_DOT_IN_LABEL
4787 #define FILE_FUNCTION_FORMAT "_GLOBAL_.D.%s"
4788 #else /* NO_DOT_IN_LABEL */
4789 #define FILE_FUNCTION_FORMAT "_GLOBAL__D_%s"
4790 #endif /* NO_DOT_IN_LABEL */
4791 #endif /* NO_DOLLAR_IN_LABEL */
4793 extern char * first_global_object_name;
4795 /* If KIND=='I', return a suitable global initializer (constructor) name.
4796 If KIND=='D', return a suitable global clean-up (destructor) name. */
4799 get_file_function_name (kind)
4805 if (first_global_object_name)
4806 p = first_global_object_name;
4807 else if (main_input_filename)
4808 p = main_input_filename;
4812 buf = (char *) alloca (sizeof (FILE_FUNCTION_FORMAT) + strlen (p));
4814 /* Set up the name of the file-level functions we may need. */
4815 /* Use a global object (which is already required to be unique over
4816 the program) rather than the file name (which imposes extra
4817 constraints). -- Raeburn@MIT.EDU, 10 Jan 1990. */
4818 sprintf (buf, FILE_FUNCTION_FORMAT, p);
4820 /* Don't need to pull weird characters out of global names. */
4821 if (p != first_global_object_name)
4823 for (p = buf+11; *p; p++)
4824 if (! ((*p >= '0' && *p <= '9')
4825 #if 0 /* we always want labels, which are valid C++ identifiers (+ `$') */
4826 #ifndef ASM_IDENTIFY_GCC /* this is required if `.' is invalid -- k. raeburn */
4830 #ifndef NO_DOLLAR_IN_LABEL /* this for `$'; unlikely, but... -- kr */
4833 #ifndef NO_DOT_IN_LABEL /* this for `.'; unlikely, but... */
4836 || (*p >= 'A' && *p <= 'Z')
4837 || (*p >= 'a' && *p <= 'z')))
4841 buf[FILE_FUNCTION_PREFIX_LEN] = kind;
4843 return get_identifier (buf);
4846 /* Expand (the constant part of) a SET_TYPE CONSTRUCTOR node.
4847 The result is placed in BUFFER (which has length BIT_SIZE),
4848 with one bit in each char ('\000' or '\001').
4850 If the constructor is constant, NULL_TREE is returned.
4851 Otherwise, a TREE_LIST of the non-constant elements is emitted. */
4854 get_set_constructor_bits (init, buffer, bit_size)
4861 HOST_WIDE_INT domain_min
4862 = TREE_INT_CST_LOW (TYPE_MIN_VALUE (TYPE_DOMAIN (TREE_TYPE (init))));
4863 tree non_const_bits = NULL_TREE;
4864 for (i = 0; i < bit_size; i++)
4867 for (vals = TREE_OPERAND (init, 1);
4868 vals != NULL_TREE; vals = TREE_CHAIN (vals))
4870 if (TREE_CODE (TREE_VALUE (vals)) != INTEGER_CST
4871 || (TREE_PURPOSE (vals) != NULL_TREE
4872 && TREE_CODE (TREE_PURPOSE (vals)) != INTEGER_CST))
4874 = tree_cons (TREE_PURPOSE (vals), TREE_VALUE (vals), non_const_bits);
4875 else if (TREE_PURPOSE (vals) != NULL_TREE)
4877 /* Set a range of bits to ones. */
4878 HOST_WIDE_INT lo_index
4879 = TREE_INT_CST_LOW (TREE_PURPOSE (vals)) - domain_min;
4880 HOST_WIDE_INT hi_index
4881 = TREE_INT_CST_LOW (TREE_VALUE (vals)) - domain_min;
4882 if (lo_index < 0 || lo_index >= bit_size
4883 || hi_index < 0 || hi_index >= bit_size)
4885 for ( ; lo_index <= hi_index; lo_index++)
4886 buffer[lo_index] = 1;
4890 /* Set a single bit to one. */
4892 = TREE_INT_CST_LOW (TREE_VALUE (vals)) - domain_min;
4893 if (index < 0 || index >= bit_size)
4895 error ("invalid initializer for bit string");
4901 return non_const_bits;
4904 /* Expand (the constant part of) a SET_TYPE CONSTRUCTOR node.
4905 The result is placed in BUFFER (which is an array of bytes).
4906 If the constructor is constant, NULL_TREE is returned.
4907 Otherwise, a TREE_LIST of the non-constant elements is emitted. */
4910 get_set_constructor_bytes (init, buffer, wd_size)
4912 unsigned char *buffer;
4916 int set_word_size = BITS_PER_UNIT;
4917 int bit_size = wd_size * set_word_size;
4919 unsigned char *bytep = buffer;
4920 char *bit_buffer = (char *) alloca(bit_size);
4921 tree non_const_bits = get_set_constructor_bits (init, bit_buffer, bit_size);
4923 for (i = 0; i < wd_size; i++)
4926 for (i = 0; i < bit_size; i++)
4930 if (BYTES_BIG_ENDIAN)
4931 *bytep |= (1 << (set_word_size - 1 - bit_pos));
4933 *bytep |= 1 << bit_pos;
4936 if (bit_pos >= set_word_size)
4937 bit_pos = 0, bytep++;
4939 return non_const_bits;
4942 #ifdef ENABLE_CHECKING
4943 /* Complain if the tree code does not match the expected one. */
4946 tree_check (node, code, file, line, nofatal)
4948 enum tree_code code;
4953 if (TREE_CODE (node) != code)
4958 fatal ("%s:%d: Expect %s, have %s\n", file, line,
4959 tree_code_name[code], tree_code_name[TREE_CODE (node)]);
4965 /* Complain if the class of the tree node does not match. */
4968 tree_class_check (node, cl, file, line, nofatal)
4975 if (TREE_CODE_CLASS (TREE_CODE (node)) != cl)
4980 fatal ("%s:%d: Expect '%c', have '%s'\n", file, line,
4981 cl, tree_code_name[TREE_CODE (node)]);
4986 /* Complain if the node is not an expression. */
4989 expr_check (node, ignored, file, line, nofatal)
4996 switch (TREE_CODE_CLASS (TREE_CODE (node)))
5010 fatal ("%s:%d: Expect expression, have '%s'\n", file, line,
5011 tree_code_name[TREE_CODE (node)]);