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
53 /* obstack.[ch] explicitly declined to prototype this. */
54 extern int _obstack_allocated_p PROTO ((struct obstack *h, GENERIC_PTR obj));
56 /* Tree nodes of permanent duration are allocated in this obstack.
57 They are the identifier nodes, and everything outside of
58 the bodies and parameters of function definitions. */
60 struct obstack permanent_obstack;
62 /* The initial RTL, and all ..._TYPE nodes, in a function
63 are allocated in this obstack. Usually they are freed at the
64 end of the function, but if the function is inline they are saved.
65 For top-level functions, this is maybepermanent_obstack.
66 Separate obstacks are made for nested functions. */
68 struct obstack *function_maybepermanent_obstack;
70 /* This is the function_maybepermanent_obstack for top-level functions. */
72 struct obstack maybepermanent_obstack;
74 /* This is a list of function_maybepermanent_obstacks for top-level inline
75 functions that are compiled in the middle of compiling other functions. */
77 struct simple_obstack_stack *toplev_inline_obstacks;
79 /* Former elements of toplev_inline_obstacks that have been recycled. */
81 struct simple_obstack_stack *extra_inline_obstacks;
83 /* This is a list of function_maybepermanent_obstacks for inline functions
84 nested in the current function that were compiled in the middle of
85 compiling other functions. */
87 struct simple_obstack_stack *inline_obstacks;
89 /* The contents of the current function definition are allocated
90 in this obstack, and all are freed at the end of the function.
91 For top-level functions, this is temporary_obstack.
92 Separate obstacks are made for nested functions. */
94 struct obstack *function_obstack;
96 /* This is used for reading initializers of global variables. */
98 struct obstack temporary_obstack;
100 /* The tree nodes of an expression are allocated
101 in this obstack, and all are freed at the end of the expression. */
103 struct obstack momentary_obstack;
105 /* The tree nodes of a declarator are allocated
106 in this obstack, and all are freed when the declarator
109 static struct obstack temp_decl_obstack;
111 /* This points at either permanent_obstack
112 or the current function_maybepermanent_obstack. */
114 struct obstack *saveable_obstack;
116 /* This is same as saveable_obstack during parse and expansion phase;
117 it points to the current function's obstack during optimization.
118 This is the obstack to be used for creating rtl objects. */
120 struct obstack *rtl_obstack;
122 /* This points at either permanent_obstack or the current function_obstack. */
124 struct obstack *current_obstack;
126 /* This points at either permanent_obstack or the current function_obstack
127 or momentary_obstack. */
129 struct obstack *expression_obstack;
131 /* Stack of obstack selections for push_obstacks and pop_obstacks. */
135 struct obstack_stack *next;
136 struct obstack *current;
137 struct obstack *saveable;
138 struct obstack *expression;
142 struct obstack_stack *obstack_stack;
144 /* Obstack for allocating struct obstack_stack entries. */
146 static struct obstack obstack_stack_obstack;
148 /* Addresses of first objects in some obstacks.
149 This is for freeing their entire contents. */
150 char *maybepermanent_firstobj;
151 char *temporary_firstobj;
152 char *momentary_firstobj;
153 char *temp_decl_firstobj;
155 /* This is used to preserve objects (mainly array initializers) that need to
156 live until the end of the current function, but no further. */
157 char *momentary_function_firstobj;
159 /* Nonzero means all ..._TYPE nodes should be allocated permanently. */
161 int all_types_permanent;
163 /* Stack of places to restore the momentary obstack back to. */
165 struct momentary_level
167 /* Pointer back to previous such level. */
168 struct momentary_level *prev;
169 /* First object allocated within this level. */
171 /* Value of expression_obstack saved at entry to this level. */
172 struct obstack *obstack;
175 struct momentary_level *momentary_stack;
177 /* Table indexed by tree code giving a string containing a character
178 classifying the tree code. Possibilities are
179 t, d, s, c, r, <, 1, 2 and e. See tree.def for details. */
181 #define DEFTREECODE(SYM, NAME, TYPE, LENGTH) TYPE,
183 char tree_code_type[MAX_TREE_CODES] = {
188 /* Table indexed by tree code giving number of expression
189 operands beyond the fixed part of the node structure.
190 Not used for types or decls. */
192 #define DEFTREECODE(SYM, NAME, TYPE, LENGTH) LENGTH,
194 int tree_code_length[MAX_TREE_CODES] = {
199 /* Names of tree components.
200 Used for printing out the tree and error messages. */
201 #define DEFTREECODE(SYM, NAME, TYPE, LEN) NAME,
203 char *tree_code_name[MAX_TREE_CODES] = {
208 /* Statistics-gathering stuff. */
229 int tree_node_counts[(int)all_kinds];
230 int tree_node_sizes[(int)all_kinds];
231 int id_string_size = 0;
233 char *tree_node_kind_names[] = {
251 /* Hash table for uniquizing IDENTIFIER_NODEs by name. */
253 #define MAX_HASH_TABLE 1009
254 static tree hash_table[MAX_HASH_TABLE]; /* id hash buckets */
256 /* 0 while creating built-in identifiers. */
257 static int do_identifier_warnings;
259 /* Unique id for next decl created. */
260 static int next_decl_uid;
261 /* Unique id for next type created. */
262 static int next_type_uid = 1;
264 /* The language-specific function for alias analysis. If NULL, the
265 language does not do any special alias analysis. */
266 int (*lang_get_alias_set) PROTO((tree));
268 /* Here is how primitive or already-canonicalized types' hash
270 #define TYPE_HASH(TYPE) ((unsigned long) (TYPE) & 0777777)
272 extern char *mode_name[];
274 void gcc_obstack_init ();
276 /* Init the principal obstacks. */
281 gcc_obstack_init (&obstack_stack_obstack);
282 gcc_obstack_init (&permanent_obstack);
284 gcc_obstack_init (&temporary_obstack);
285 temporary_firstobj = (char *) obstack_alloc (&temporary_obstack, 0);
286 gcc_obstack_init (&momentary_obstack);
287 momentary_firstobj = (char *) obstack_alloc (&momentary_obstack, 0);
288 momentary_function_firstobj = momentary_firstobj;
289 gcc_obstack_init (&maybepermanent_obstack);
290 maybepermanent_firstobj
291 = (char *) obstack_alloc (&maybepermanent_obstack, 0);
292 gcc_obstack_init (&temp_decl_obstack);
293 temp_decl_firstobj = (char *) obstack_alloc (&temp_decl_obstack, 0);
295 function_obstack = &temporary_obstack;
296 function_maybepermanent_obstack = &maybepermanent_obstack;
297 current_obstack = &permanent_obstack;
298 expression_obstack = &permanent_obstack;
299 rtl_obstack = saveable_obstack = &permanent_obstack;
301 /* Init the hash table of identifiers. */
302 bzero ((char *) hash_table, sizeof hash_table);
306 gcc_obstack_init (obstack)
307 struct obstack *obstack;
309 /* Let particular systems override the size of a chunk. */
310 #ifndef OBSTACK_CHUNK_SIZE
311 #define OBSTACK_CHUNK_SIZE 0
313 /* Let them override the alloc and free routines too. */
314 #ifndef OBSTACK_CHUNK_ALLOC
315 #define OBSTACK_CHUNK_ALLOC xmalloc
317 #ifndef OBSTACK_CHUNK_FREE
318 #define OBSTACK_CHUNK_FREE free
320 _obstack_begin (obstack, OBSTACK_CHUNK_SIZE, 0,
321 (void *(*) ()) OBSTACK_CHUNK_ALLOC,
322 (void (*) ()) OBSTACK_CHUNK_FREE);
325 /* Save all variables describing the current status into the structure *P.
326 This is used before starting a nested function.
328 CONTEXT is the decl_function_context for the function we're about to
329 compile; if it isn't current_function_decl, we have to play some games. */
332 save_tree_status (p, context)
336 p->all_types_permanent = all_types_permanent;
337 p->momentary_stack = momentary_stack;
338 p->maybepermanent_firstobj = maybepermanent_firstobj;
339 p->temporary_firstobj = temporary_firstobj;
340 p->momentary_firstobj = momentary_firstobj;
341 p->momentary_function_firstobj = momentary_function_firstobj;
342 p->function_obstack = function_obstack;
343 p->function_maybepermanent_obstack = function_maybepermanent_obstack;
344 p->current_obstack = current_obstack;
345 p->expression_obstack = expression_obstack;
346 p->saveable_obstack = saveable_obstack;
347 p->rtl_obstack = rtl_obstack;
348 p->inline_obstacks = inline_obstacks;
350 if (context == current_function_decl)
351 /* Objects that need to be saved in this function can be in the nonsaved
352 obstack of the enclosing function since they can't possibly be needed
353 once it has returned. */
354 function_maybepermanent_obstack = function_obstack;
357 /* We're compiling a function which isn't nested in the current
358 function. We need to create a new maybepermanent_obstack for this
359 function, since it can't go onto any of the existing obstacks. */
360 struct simple_obstack_stack **head;
361 struct simple_obstack_stack *current;
363 if (context == NULL_TREE)
364 head = &toplev_inline_obstacks;
367 struct function *f = find_function_data (context);
368 head = &f->inline_obstacks;
371 if (context == NULL_TREE && extra_inline_obstacks)
373 current = extra_inline_obstacks;
374 extra_inline_obstacks = current->next;
378 current = ((struct simple_obstack_stack *)
379 xmalloc (sizeof (struct simple_obstack_stack)));
382 = (struct obstack *) xmalloc (sizeof (struct obstack));
383 gcc_obstack_init (current->obstack);
386 function_maybepermanent_obstack = current->obstack;
388 current->next = *head;
392 maybepermanent_firstobj
393 = (char *) obstack_finish (function_maybepermanent_obstack);
395 function_obstack = (struct obstack *) xmalloc (sizeof (struct obstack));
396 gcc_obstack_init (function_obstack);
398 current_obstack = &permanent_obstack;
399 expression_obstack = &permanent_obstack;
400 rtl_obstack = saveable_obstack = &permanent_obstack;
402 temporary_firstobj = (char *) obstack_alloc (&temporary_obstack, 0);
403 momentary_firstobj = (char *) obstack_finish (&momentary_obstack);
404 momentary_function_firstobj = momentary_firstobj;
407 /* Restore all variables describing the current status from the structure *P.
408 This is used after a nested function. */
411 restore_tree_status (p, context)
415 all_types_permanent = p->all_types_permanent;
416 momentary_stack = p->momentary_stack;
418 obstack_free (&momentary_obstack, momentary_function_firstobj);
420 /* Free saveable storage used by the function just compiled and not
423 CAUTION: This is in function_obstack of the containing function.
424 So we must be sure that we never allocate from that obstack during
425 the compilation of a nested function if we expect it to survive
426 past the nested function's end. */
427 obstack_free (function_maybepermanent_obstack, maybepermanent_firstobj);
429 /* If we were compiling a toplevel function, we can free this space now. */
430 if (context == NULL_TREE)
432 obstack_free (&temporary_obstack, temporary_firstobj);
433 obstack_free (&momentary_obstack, momentary_function_firstobj);
436 /* If we were compiling a toplevel function that we don't actually want
437 to save anything from, return the obstack to the pool. */
438 if (context == NULL_TREE
439 && obstack_empty_p (function_maybepermanent_obstack))
441 struct simple_obstack_stack *current, **p = &toplev_inline_obstacks;
445 while ((*p)->obstack != function_maybepermanent_obstack)
450 current->next = extra_inline_obstacks;
451 extra_inline_obstacks = current;
455 obstack_free (function_obstack, 0);
456 free (function_obstack);
458 temporary_firstobj = p->temporary_firstobj;
459 momentary_firstobj = p->momentary_firstobj;
460 momentary_function_firstobj = p->momentary_function_firstobj;
461 maybepermanent_firstobj = p->maybepermanent_firstobj;
462 function_obstack = p->function_obstack;
463 function_maybepermanent_obstack = p->function_maybepermanent_obstack;
464 current_obstack = p->current_obstack;
465 expression_obstack = p->expression_obstack;
466 saveable_obstack = p->saveable_obstack;
467 rtl_obstack = p->rtl_obstack;
468 inline_obstacks = p->inline_obstacks;
471 /* Start allocating on the temporary (per function) obstack.
472 This is done in start_function before parsing the function body,
473 and before each initialization at top level, and to go back
474 to temporary allocation after doing permanent_allocation. */
477 temporary_allocation ()
479 /* Note that function_obstack at top level points to temporary_obstack.
480 But within a nested function context, it is a separate obstack. */
481 current_obstack = function_obstack;
482 expression_obstack = function_obstack;
483 rtl_obstack = saveable_obstack = function_maybepermanent_obstack;
488 /* Start allocating on the permanent obstack but don't
489 free the temporary data. After calling this, call
490 `permanent_allocation' to fully resume permanent allocation status. */
493 end_temporary_allocation ()
495 current_obstack = &permanent_obstack;
496 expression_obstack = &permanent_obstack;
497 rtl_obstack = saveable_obstack = &permanent_obstack;
500 /* Resume allocating on the temporary obstack, undoing
501 effects of `end_temporary_allocation'. */
504 resume_temporary_allocation ()
506 current_obstack = function_obstack;
507 expression_obstack = function_obstack;
508 rtl_obstack = saveable_obstack = function_maybepermanent_obstack;
511 /* While doing temporary allocation, switch to allocating in such a
512 way as to save all nodes if the function is inlined. Call
513 resume_temporary_allocation to go back to ordinary temporary
517 saveable_allocation ()
519 /* Note that function_obstack at top level points to temporary_obstack.
520 But within a nested function context, it is a separate obstack. */
521 expression_obstack = current_obstack = saveable_obstack;
524 /* Switch to current obstack CURRENT and maybepermanent obstack SAVEABLE,
525 recording the previously current obstacks on a stack.
526 This does not free any storage in any obstack. */
529 push_obstacks (current, saveable)
530 struct obstack *current, *saveable;
532 struct obstack_stack *p
533 = (struct obstack_stack *) obstack_alloc (&obstack_stack_obstack,
534 (sizeof (struct obstack_stack)));
536 p->current = current_obstack;
537 p->saveable = saveable_obstack;
538 p->expression = expression_obstack;
539 p->rtl = rtl_obstack;
540 p->next = obstack_stack;
543 current_obstack = current;
544 expression_obstack = current;
545 rtl_obstack = saveable_obstack = saveable;
548 /* Save the current set of obstacks, but don't change them. */
551 push_obstacks_nochange ()
553 struct obstack_stack *p
554 = (struct obstack_stack *) obstack_alloc (&obstack_stack_obstack,
555 (sizeof (struct obstack_stack)));
557 p->current = current_obstack;
558 p->saveable = saveable_obstack;
559 p->expression = expression_obstack;
560 p->rtl = rtl_obstack;
561 p->next = obstack_stack;
565 /* Pop the obstack selection stack. */
570 struct obstack_stack *p = obstack_stack;
571 obstack_stack = p->next;
573 current_obstack = p->current;
574 saveable_obstack = p->saveable;
575 expression_obstack = p->expression;
576 rtl_obstack = p->rtl;
578 obstack_free (&obstack_stack_obstack, p);
581 /* Nonzero if temporary allocation is currently in effect.
582 Zero if currently doing permanent allocation. */
585 allocation_temporary_p ()
587 return current_obstack != &permanent_obstack;
590 /* Go back to allocating on the permanent obstack
591 and free everything in the temporary obstack.
593 FUNCTION_END is true only if we have just finished compiling a function.
594 In that case, we also free preserved initial values on the momentary
598 permanent_allocation (function_end)
601 /* Free up previous temporary obstack data */
602 obstack_free (&temporary_obstack, temporary_firstobj);
605 obstack_free (&momentary_obstack, momentary_function_firstobj);
606 momentary_firstobj = momentary_function_firstobj;
609 obstack_free (&momentary_obstack, momentary_firstobj);
610 obstack_free (function_maybepermanent_obstack, maybepermanent_firstobj);
611 obstack_free (&temp_decl_obstack, temp_decl_firstobj);
613 /* Free up the maybepermanent_obstacks for any of our nested functions
614 which were compiled at a lower level. */
615 while (inline_obstacks)
617 struct simple_obstack_stack *current = inline_obstacks;
618 inline_obstacks = current->next;
619 obstack_free (current->obstack, 0);
620 free (current->obstack);
624 current_obstack = &permanent_obstack;
625 expression_obstack = &permanent_obstack;
626 rtl_obstack = saveable_obstack = &permanent_obstack;
629 /* Save permanently everything on the maybepermanent_obstack. */
634 maybepermanent_firstobj
635 = (char *) obstack_alloc (function_maybepermanent_obstack, 0);
639 preserve_initializer ()
641 struct momentary_level *tem;
645 = (char *) obstack_alloc (&temporary_obstack, 0);
646 maybepermanent_firstobj
647 = (char *) obstack_alloc (function_maybepermanent_obstack, 0);
649 old_momentary = momentary_firstobj;
651 = (char *) obstack_alloc (&momentary_obstack, 0);
652 if (momentary_firstobj != old_momentary)
653 for (tem = momentary_stack; tem; tem = tem->prev)
654 tem->base = momentary_firstobj;
657 /* Start allocating new rtl in current_obstack.
658 Use resume_temporary_allocation
659 to go back to allocating rtl in saveable_obstack. */
662 rtl_in_current_obstack ()
664 rtl_obstack = current_obstack;
667 /* Start allocating rtl from saveable_obstack. Intended to be used after
668 a call to push_obstacks_nochange. */
671 rtl_in_saveable_obstack ()
673 rtl_obstack = saveable_obstack;
676 /* Allocate SIZE bytes in the current obstack
677 and return a pointer to them.
678 In practice the current obstack is always the temporary one. */
684 return (char *) obstack_alloc (current_obstack, size);
687 /* Free the object PTR in the current obstack
688 as well as everything allocated since PTR.
689 In practice the current obstack is always the temporary one. */
695 obstack_free (current_obstack, ptr);
698 /* Allocate SIZE bytes in the permanent obstack
699 and return a pointer to them. */
705 return (char *) obstack_alloc (&permanent_obstack, size);
708 /* Allocate NELEM items of SIZE bytes in the permanent obstack
709 and return a pointer to them. The storage is cleared before
710 returning the value. */
713 perm_calloc (nelem, size)
717 char *rval = (char *) obstack_alloc (&permanent_obstack, nelem * size);
718 bzero (rval, nelem * size);
722 /* Allocate SIZE bytes in the saveable obstack
723 and return a pointer to them. */
729 return (char *) obstack_alloc (saveable_obstack, size);
732 /* Allocate SIZE bytes in the expression obstack
733 and return a pointer to them. */
739 return (char *) obstack_alloc (expression_obstack, size);
742 /* Print out which obstack an object is in. */
745 print_obstack_name (object, file, prefix)
750 struct obstack *obstack = NULL;
751 char *obstack_name = NULL;
754 for (p = outer_function_chain; p; p = p->next)
756 if (_obstack_allocated_p (p->function_obstack, object))
758 obstack = p->function_obstack;
759 obstack_name = "containing function obstack";
761 if (_obstack_allocated_p (p->function_maybepermanent_obstack, object))
763 obstack = p->function_maybepermanent_obstack;
764 obstack_name = "containing function maybepermanent obstack";
768 if (_obstack_allocated_p (&obstack_stack_obstack, object))
770 obstack = &obstack_stack_obstack;
771 obstack_name = "obstack_stack_obstack";
773 else if (_obstack_allocated_p (function_obstack, object))
775 obstack = function_obstack;
776 obstack_name = "function obstack";
778 else if (_obstack_allocated_p (&permanent_obstack, object))
780 obstack = &permanent_obstack;
781 obstack_name = "permanent_obstack";
783 else if (_obstack_allocated_p (&momentary_obstack, object))
785 obstack = &momentary_obstack;
786 obstack_name = "momentary_obstack";
788 else if (_obstack_allocated_p (function_maybepermanent_obstack, object))
790 obstack = function_maybepermanent_obstack;
791 obstack_name = "function maybepermanent obstack";
793 else if (_obstack_allocated_p (&temp_decl_obstack, object))
795 obstack = &temp_decl_obstack;
796 obstack_name = "temp_decl_obstack";
799 /* Check to see if the object is in the free area of the obstack. */
802 if (object >= obstack->next_free
803 && object < obstack->chunk_limit)
804 fprintf (file, "%s in free portion of obstack %s",
805 prefix, obstack_name);
807 fprintf (file, "%s allocated from %s", prefix, obstack_name);
810 fprintf (file, "%s not allocated from any obstack", prefix);
814 debug_obstack (object)
817 print_obstack_name (object, stderr, "object");
818 fprintf (stderr, ".\n");
821 /* Return 1 if OBJ is in the permanent obstack.
822 This is slow, and should be used only for debugging.
823 Use TREE_PERMANENT for other purposes. */
826 object_permanent_p (obj)
829 return _obstack_allocated_p (&permanent_obstack, obj);
832 /* Start a level of momentary allocation.
833 In C, each compound statement has its own level
834 and that level is freed at the end of each statement.
835 All expression nodes are allocated in the momentary allocation level. */
840 struct momentary_level *tem
841 = (struct momentary_level *) obstack_alloc (&momentary_obstack,
842 sizeof (struct momentary_level));
843 tem->prev = momentary_stack;
844 tem->base = (char *) obstack_base (&momentary_obstack);
845 tem->obstack = expression_obstack;
846 momentary_stack = tem;
847 expression_obstack = &momentary_obstack;
850 /* Set things up so the next clear_momentary will only clear memory
851 past our present position in momentary_obstack. */
854 preserve_momentary ()
856 momentary_stack->base = (char *) obstack_base (&momentary_obstack);
859 /* Free all the storage in the current momentary-allocation level.
860 In C, this happens at the end of each statement. */
865 obstack_free (&momentary_obstack, momentary_stack->base);
868 /* Discard a level of momentary allocation.
869 In C, this happens at the end of each compound statement.
870 Restore the status of expression node allocation
871 that was in effect before this level was created. */
876 struct momentary_level *tem = momentary_stack;
877 momentary_stack = tem->prev;
878 expression_obstack = tem->obstack;
879 /* We can't free TEM from the momentary_obstack, because there might
880 be objects above it which have been saved. We can free back to the
881 stack of the level we are popping off though. */
882 obstack_free (&momentary_obstack, tem->base);
885 /* Pop back to the previous level of momentary allocation,
886 but don't free any momentary data just yet. */
889 pop_momentary_nofree ()
891 struct momentary_level *tem = momentary_stack;
892 momentary_stack = tem->prev;
893 expression_obstack = tem->obstack;
896 /* Call when starting to parse a declaration:
897 make expressions in the declaration last the length of the function.
898 Returns an argument that should be passed to resume_momentary later. */
903 register int tem = expression_obstack == &momentary_obstack;
904 expression_obstack = saveable_obstack;
908 /* Call when finished parsing a declaration:
909 restore the treatment of node-allocation that was
910 in effect before the suspension.
911 YES should be the value previously returned by suspend_momentary. */
914 resume_momentary (yes)
918 expression_obstack = &momentary_obstack;
921 /* Init the tables indexed by tree code.
922 Note that languages can add to these tables to define their own codes. */
930 /* Return a newly allocated node of code CODE.
931 Initialize the node's unique id and its TREE_PERMANENT flag.
932 For decl and type nodes, some other fields are initialized.
933 The rest of the node is initialized to zero.
935 Achoo! I got a code in the node. */
942 register int type = TREE_CODE_CLASS (code);
943 register int length = 0;
944 register struct obstack *obstack = current_obstack;
946 #ifdef GATHER_STATISTICS
947 register tree_node_kind kind;
952 case 'd': /* A decl node */
953 #ifdef GATHER_STATISTICS
956 length = sizeof (struct tree_decl);
957 /* All decls in an inline function need to be saved. */
958 if (obstack != &permanent_obstack)
959 obstack = saveable_obstack;
961 /* PARM_DECLs go on the context of the parent. If this is a nested
962 function, then we must allocate the PARM_DECL on the parent's
963 obstack, so that they will live to the end of the parent's
964 closing brace. This is necessary in case we try to inline the
965 function into its parent.
967 PARM_DECLs of top-level functions do not have this problem. However,
968 we allocate them where we put the FUNCTION_DECL for languages such as
969 Ada that need to consult some flags in the PARM_DECLs of the function
972 See comment in restore_tree_status for why we can't put this
973 in function_obstack. */
974 if (code == PARM_DECL && obstack != &permanent_obstack)
977 if (current_function_decl)
978 context = decl_function_context (current_function_decl);
982 = find_function_data (context)->function_maybepermanent_obstack;
986 case 't': /* a type node */
987 #ifdef GATHER_STATISTICS
990 length = sizeof (struct tree_type);
991 /* All data types are put where we can preserve them if nec. */
992 if (obstack != &permanent_obstack)
993 obstack = all_types_permanent ? &permanent_obstack : saveable_obstack;
996 case 'b': /* a lexical block */
997 #ifdef GATHER_STATISTICS
1000 length = sizeof (struct tree_block);
1001 /* All BLOCK nodes are put where we can preserve them if nec. */
1002 if (obstack != &permanent_obstack)
1003 obstack = saveable_obstack;
1006 case 's': /* an expression with side effects */
1007 #ifdef GATHER_STATISTICS
1011 case 'r': /* a reference */
1012 #ifdef GATHER_STATISTICS
1016 case 'e': /* an expression */
1017 case '<': /* a comparison expression */
1018 case '1': /* a unary arithmetic expression */
1019 case '2': /* a binary arithmetic expression */
1020 #ifdef GATHER_STATISTICS
1024 obstack = expression_obstack;
1025 /* All BIND_EXPR nodes are put where we can preserve them if nec. */
1026 if (code == BIND_EXPR && obstack != &permanent_obstack)
1027 obstack = saveable_obstack;
1028 length = sizeof (struct tree_exp)
1029 + (tree_code_length[(int) code] - 1) * sizeof (char *);
1032 case 'c': /* a constant */
1033 #ifdef GATHER_STATISTICS
1036 obstack = expression_obstack;
1038 /* We can't use tree_code_length for INTEGER_CST, since the number of
1039 words is machine-dependent due to varying length of HOST_WIDE_INT,
1040 which might be wider than a pointer (e.g., long long). Similarly
1041 for REAL_CST, since the number of words is machine-dependent due
1042 to varying size and alignment of `double'. */
1044 if (code == INTEGER_CST)
1045 length = sizeof (struct tree_int_cst);
1046 else if (code == REAL_CST)
1047 length = sizeof (struct tree_real_cst);
1049 length = sizeof (struct tree_common)
1050 + tree_code_length[(int) code] * sizeof (char *);
1053 case 'x': /* something random, like an identifier. */
1054 #ifdef GATHER_STATISTICS
1055 if (code == IDENTIFIER_NODE)
1057 else if (code == OP_IDENTIFIER)
1059 else if (code == TREE_VEC)
1064 length = sizeof (struct tree_common)
1065 + tree_code_length[(int) code] * sizeof (char *);
1066 /* Identifier nodes are always permanent since they are
1067 unique in a compiler run. */
1068 if (code == IDENTIFIER_NODE) obstack = &permanent_obstack;
1075 t = (tree) obstack_alloc (obstack, length);
1077 #ifdef GATHER_STATISTICS
1078 tree_node_counts[(int)kind]++;
1079 tree_node_sizes[(int)kind] += length;
1082 /* Clear a word at a time. */
1083 for (i = (length / sizeof (int)) - 1; i >= 0; i--)
1085 /* Clear any extra bytes. */
1086 for (i = length / sizeof (int) * sizeof (int); i < length; i++)
1087 ((char *) t)[i] = 0;
1089 TREE_SET_CODE (t, code);
1090 if (obstack == &permanent_obstack)
1091 TREE_PERMANENT (t) = 1;
1096 TREE_SIDE_EFFECTS (t) = 1;
1097 TREE_TYPE (t) = void_type_node;
1101 if (code != FUNCTION_DECL)
1103 DECL_IN_SYSTEM_HEADER (t)
1104 = in_system_header && (obstack == &permanent_obstack);
1105 DECL_SOURCE_LINE (t) = lineno;
1106 DECL_SOURCE_FILE (t) = (input_filename) ? input_filename : "<built-in>";
1107 DECL_UID (t) = next_decl_uid++;
1111 TYPE_UID (t) = next_type_uid++;
1113 TYPE_MAIN_VARIANT (t) = t;
1114 TYPE_OBSTACK (t) = obstack;
1115 TYPE_ATTRIBUTES (t) = NULL_TREE;
1116 #ifdef SET_DEFAULT_TYPE_ATTRIBUTES
1117 SET_DEFAULT_TYPE_ATTRIBUTES (t);
1119 /* Note that we have not yet computed the alias set for this
1121 TYPE_ALIAS_SET (t) = -1;
1125 TREE_CONSTANT (t) = 1;
1132 /* Return a new node with the same contents as NODE
1133 except that its TREE_CHAIN is zero and it has a fresh uid. */
1140 register enum tree_code code = TREE_CODE (node);
1141 register int length = 0;
1144 switch (TREE_CODE_CLASS (code))
1146 case 'd': /* A decl node */
1147 length = sizeof (struct tree_decl);
1150 case 't': /* a type node */
1151 length = sizeof (struct tree_type);
1154 case 'b': /* a lexical block node */
1155 length = sizeof (struct tree_block);
1158 case 'r': /* a reference */
1159 case 'e': /* an expression */
1160 case 's': /* an expression with side effects */
1161 case '<': /* a comparison expression */
1162 case '1': /* a unary arithmetic expression */
1163 case '2': /* a binary arithmetic expression */
1164 length = sizeof (struct tree_exp)
1165 + (tree_code_length[(int) code] - 1) * sizeof (char *);
1168 case 'c': /* a constant */
1169 /* We can't use tree_code_length for INTEGER_CST, since the number of
1170 words is machine-dependent due to varying length of HOST_WIDE_INT,
1171 which might be wider than a pointer (e.g., long long). Similarly
1172 for REAL_CST, since the number of words is machine-dependent due
1173 to varying size and alignment of `double'. */
1174 if (code == INTEGER_CST)
1175 length = sizeof (struct tree_int_cst);
1176 else if (code == REAL_CST)
1177 length = sizeof (struct tree_real_cst);
1179 length = (sizeof (struct tree_common)
1180 + tree_code_length[(int) code] * sizeof (char *));
1183 case 'x': /* something random, like an identifier. */
1184 length = sizeof (struct tree_common)
1185 + tree_code_length[(int) code] * sizeof (char *);
1186 if (code == TREE_VEC)
1187 length += (TREE_VEC_LENGTH (node) - 1) * sizeof (char *);
1190 t = (tree) obstack_alloc (current_obstack, length);
1192 for (i = (length / sizeof (int)) - 1; i >= 0; i--)
1193 ((int *) t)[i] = ((int *) node)[i];
1194 /* Clear any extra bytes. */
1195 for (i = length / sizeof (int) * sizeof (int); i < length; i++)
1196 ((char *) t)[i] = ((char *) node)[i];
1198 /* EXPR_WITH_FILE_LOCATION must keep filename info stored in TREE_CHAIN */
1199 if (TREE_CODE (node) != EXPR_WITH_FILE_LOCATION)
1201 TREE_ASM_WRITTEN (t) = 0;
1203 if (TREE_CODE_CLASS (code) == 'd')
1204 DECL_UID (t) = next_decl_uid++;
1205 else if (TREE_CODE_CLASS (code) == 't')
1207 TYPE_UID (t) = next_type_uid++;
1208 TYPE_OBSTACK (t) = current_obstack;
1210 /* The following is so that the debug code for
1211 the copy is different from the original type.
1212 The two statements usually duplicate each other
1213 (because they clear fields of the same union),
1214 but the optimizer should catch that. */
1215 TYPE_SYMTAB_POINTER (t) = 0;
1216 TYPE_SYMTAB_ADDRESS (t) = 0;
1219 TREE_PERMANENT (t) = (current_obstack == &permanent_obstack);
1224 /* Return a copy of a chain of nodes, chained through the TREE_CHAIN field.
1225 For example, this can copy a list made of TREE_LIST nodes. */
1232 register tree prev, next;
1237 head = prev = copy_node (list);
1238 next = TREE_CHAIN (list);
1241 TREE_CHAIN (prev) = copy_node (next);
1242 prev = TREE_CHAIN (prev);
1243 next = TREE_CHAIN (next);
1250 /* Return an IDENTIFIER_NODE whose name is TEXT (a null-terminated string).
1251 If an identifier with that name has previously been referred to,
1252 the same node is returned this time. */
1255 get_identifier (text)
1256 register char *text;
1261 register int len, hash_len;
1263 /* Compute length of text in len. */
1264 for (len = 0; text[len]; len++);
1266 /* Decide how much of that length to hash on */
1268 if (warn_id_clash && len > id_clash_len)
1269 hash_len = id_clash_len;
1271 /* Compute hash code */
1272 hi = hash_len * 613 + (unsigned) text[0];
1273 for (i = 1; i < hash_len; i += 2)
1274 hi = ((hi * 613) + (unsigned) (text[i]));
1276 hi &= (1 << HASHBITS) - 1;
1277 hi %= MAX_HASH_TABLE;
1279 /* Search table for identifier */
1280 for (idp = hash_table[hi]; idp; idp = TREE_CHAIN (idp))
1281 if (IDENTIFIER_LENGTH (idp) == len
1282 && IDENTIFIER_POINTER (idp)[0] == text[0]
1283 && !bcmp (IDENTIFIER_POINTER (idp), text, len))
1284 return idp; /* <-- return if found */
1286 /* Not found; optionally warn about a similar identifier */
1287 if (warn_id_clash && do_identifier_warnings && len >= id_clash_len)
1288 for (idp = hash_table[hi]; idp; idp = TREE_CHAIN (idp))
1289 if (!strncmp (IDENTIFIER_POINTER (idp), text, id_clash_len))
1291 warning ("`%s' and `%s' identical in first %d characters",
1292 IDENTIFIER_POINTER (idp), text, id_clash_len);
1296 if (tree_code_length[(int) IDENTIFIER_NODE] < 0)
1297 abort (); /* set_identifier_size hasn't been called. */
1299 /* Not found, create one, add to chain */
1300 idp = make_node (IDENTIFIER_NODE);
1301 IDENTIFIER_LENGTH (idp) = len;
1302 #ifdef GATHER_STATISTICS
1303 id_string_size += len;
1306 IDENTIFIER_POINTER (idp) = obstack_copy0 (&permanent_obstack, text, len);
1308 TREE_CHAIN (idp) = hash_table[hi];
1309 hash_table[hi] = idp;
1310 return idp; /* <-- return if created */
1313 /* If an identifier with the name TEXT (a null-terminated string) has
1314 previously been referred to, return that node; otherwise return
1318 maybe_get_identifier (text)
1319 register char *text;
1324 register int len, hash_len;
1326 /* Compute length of text in len. */
1327 for (len = 0; text[len]; len++);
1329 /* Decide how much of that length to hash on */
1331 if (warn_id_clash && len > id_clash_len)
1332 hash_len = id_clash_len;
1334 /* Compute hash code */
1335 hi = hash_len * 613 + (unsigned) text[0];
1336 for (i = 1; i < hash_len; i += 2)
1337 hi = ((hi * 613) + (unsigned) (text[i]));
1339 hi &= (1 << HASHBITS) - 1;
1340 hi %= MAX_HASH_TABLE;
1342 /* Search table for identifier */
1343 for (idp = hash_table[hi]; idp; idp = TREE_CHAIN (idp))
1344 if (IDENTIFIER_LENGTH (idp) == len
1345 && IDENTIFIER_POINTER (idp)[0] == text[0]
1346 && !bcmp (IDENTIFIER_POINTER (idp), text, len))
1347 return idp; /* <-- return if found */
1352 /* Enable warnings on similar identifiers (if requested).
1353 Done after the built-in identifiers are created. */
1356 start_identifier_warnings ()
1358 do_identifier_warnings = 1;
1361 /* Record the size of an identifier node for the language in use.
1362 SIZE is the total size in bytes.
1363 This is called by the language-specific files. This must be
1364 called before allocating any identifiers. */
1367 set_identifier_size (size)
1370 tree_code_length[(int) IDENTIFIER_NODE]
1371 = (size - sizeof (struct tree_common)) / sizeof (tree);
1374 /* Return a newly constructed INTEGER_CST node whose constant value
1375 is specified by the two ints LOW and HI.
1376 The TREE_TYPE is set to `int'.
1378 This function should be used via the `build_int_2' macro. */
1381 build_int_2_wide (low, hi)
1382 HOST_WIDE_INT low, hi;
1384 register tree t = make_node (INTEGER_CST);
1385 TREE_INT_CST_LOW (t) = low;
1386 TREE_INT_CST_HIGH (t) = hi;
1387 TREE_TYPE (t) = integer_type_node;
1391 /* Return a new REAL_CST node whose type is TYPE and value is D. */
1394 build_real (type, d)
1401 /* Check for valid float value for this type on this target machine;
1402 if not, can print error message and store a valid value in D. */
1403 #ifdef CHECK_FLOAT_VALUE
1404 CHECK_FLOAT_VALUE (TYPE_MODE (type), d, overflow);
1407 v = make_node (REAL_CST);
1408 TREE_TYPE (v) = type;
1409 TREE_REAL_CST (v) = d;
1410 TREE_OVERFLOW (v) = TREE_CONSTANT_OVERFLOW (v) = overflow;
1414 /* Return a new REAL_CST node whose type is TYPE
1415 and whose value is the integer value of the INTEGER_CST node I. */
1417 #if !defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
1420 real_value_from_int_cst (type, i)
1425 #ifdef REAL_ARITHMETIC
1426 if (! TREE_UNSIGNED (TREE_TYPE (i)))
1427 REAL_VALUE_FROM_INT (d, TREE_INT_CST_LOW (i), TREE_INT_CST_HIGH (i),
1430 REAL_VALUE_FROM_UNSIGNED_INT (d, TREE_INT_CST_LOW (i),
1431 TREE_INT_CST_HIGH (i), TYPE_MODE (type));
1432 #else /* not REAL_ARITHMETIC */
1433 /* Some 386 compilers mishandle unsigned int to float conversions,
1434 so introduce a temporary variable E to avoid those bugs. */
1435 if (TREE_INT_CST_HIGH (i) < 0 && ! TREE_UNSIGNED (TREE_TYPE (i)))
1439 d = (double) (~ TREE_INT_CST_HIGH (i));
1440 e = ((double) ((HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2))
1441 * (double) ((HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2)));
1443 e = (double) (unsigned HOST_WIDE_INT) (~ TREE_INT_CST_LOW (i));
1451 d = (double) (unsigned HOST_WIDE_INT) TREE_INT_CST_HIGH (i);
1452 e = ((double) ((HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2))
1453 * (double) ((HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2)));
1455 e = (double) (unsigned HOST_WIDE_INT) TREE_INT_CST_LOW (i);
1458 #endif /* not REAL_ARITHMETIC */
1462 /* This function can't be implemented if we can't do arithmetic
1463 on the float representation. */
1466 build_real_from_int_cst (type, i)
1471 int overflow = TREE_OVERFLOW (i);
1473 jmp_buf float_error;
1475 v = make_node (REAL_CST);
1476 TREE_TYPE (v) = type;
1478 if (setjmp (float_error))
1485 set_float_handler (float_error);
1487 #ifdef REAL_ARITHMETIC
1488 d = real_value_from_int_cst (type, i);
1490 d = REAL_VALUE_TRUNCATE (TYPE_MODE (type),
1491 real_value_from_int_cst (type, i));
1494 /* Check for valid float value for this type on this target machine. */
1497 set_float_handler (NULL_PTR);
1499 #ifdef CHECK_FLOAT_VALUE
1500 CHECK_FLOAT_VALUE (TYPE_MODE (type), d, overflow);
1503 TREE_REAL_CST (v) = d;
1504 TREE_OVERFLOW (v) = TREE_CONSTANT_OVERFLOW (v) = overflow;
1508 #endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */
1510 /* Return a newly constructed STRING_CST node whose value is
1511 the LEN characters at STR.
1512 The TREE_TYPE is not initialized. */
1515 build_string (len, str)
1519 /* Put the string in saveable_obstack since it will be placed in the RTL
1520 for an "asm" statement and will also be kept around a while if
1521 deferring constant output in varasm.c. */
1523 register tree s = make_node (STRING_CST);
1524 TREE_STRING_LENGTH (s) = len;
1525 TREE_STRING_POINTER (s) = obstack_copy0 (saveable_obstack, str, len);
1529 /* Return a newly constructed COMPLEX_CST node whose value is
1530 specified by the real and imaginary parts REAL and IMAG.
1531 Both REAL and IMAG should be constant nodes. TYPE, if specified,
1532 will be the type of the COMPLEX_CST; otherwise a new type will be made. */
1535 build_complex (type, real, imag)
1539 register tree t = make_node (COMPLEX_CST);
1541 TREE_REALPART (t) = real;
1542 TREE_IMAGPART (t) = imag;
1543 TREE_TYPE (t) = type ? type : build_complex_type (TREE_TYPE (real));
1544 TREE_OVERFLOW (t) = TREE_OVERFLOW (real) | TREE_OVERFLOW (imag);
1545 TREE_CONSTANT_OVERFLOW (t)
1546 = TREE_CONSTANT_OVERFLOW (real) | TREE_CONSTANT_OVERFLOW (imag);
1550 /* Build a newly constructed TREE_VEC node of length LEN. */
1557 register int length = (len-1) * sizeof (tree) + sizeof (struct tree_vec);
1558 register struct obstack *obstack = current_obstack;
1561 #ifdef GATHER_STATISTICS
1562 tree_node_counts[(int)vec_kind]++;
1563 tree_node_sizes[(int)vec_kind] += length;
1566 t = (tree) obstack_alloc (obstack, length);
1568 for (i = (length / sizeof (int)) - 1; i >= 0; i--)
1571 TREE_SET_CODE (t, TREE_VEC);
1572 TREE_VEC_LENGTH (t) = len;
1573 if (obstack == &permanent_obstack)
1574 TREE_PERMANENT (t) = 1;
1579 /* Return 1 if EXPR is the integer constant zero or a complex constant
1583 integer_zerop (expr)
1588 return ((TREE_CODE (expr) == INTEGER_CST
1589 && ! TREE_CONSTANT_OVERFLOW (expr)
1590 && TREE_INT_CST_LOW (expr) == 0
1591 && TREE_INT_CST_HIGH (expr) == 0)
1592 || (TREE_CODE (expr) == COMPLEX_CST
1593 && integer_zerop (TREE_REALPART (expr))
1594 && integer_zerop (TREE_IMAGPART (expr))));
1597 /* Return 1 if EXPR is the integer constant one or the corresponding
1598 complex constant. */
1606 return ((TREE_CODE (expr) == INTEGER_CST
1607 && ! TREE_CONSTANT_OVERFLOW (expr)
1608 && TREE_INT_CST_LOW (expr) == 1
1609 && TREE_INT_CST_HIGH (expr) == 0)
1610 || (TREE_CODE (expr) == COMPLEX_CST
1611 && integer_onep (TREE_REALPART (expr))
1612 && integer_zerop (TREE_IMAGPART (expr))));
1615 /* Return 1 if EXPR is an integer containing all 1's in as much precision as
1616 it contains. Likewise for the corresponding complex constant. */
1619 integer_all_onesp (expr)
1627 if (TREE_CODE (expr) == COMPLEX_CST
1628 && integer_all_onesp (TREE_REALPART (expr))
1629 && integer_zerop (TREE_IMAGPART (expr)))
1632 else if (TREE_CODE (expr) != INTEGER_CST
1633 || TREE_CONSTANT_OVERFLOW (expr))
1636 uns = TREE_UNSIGNED (TREE_TYPE (expr));
1638 return TREE_INT_CST_LOW (expr) == -1 && TREE_INT_CST_HIGH (expr) == -1;
1640 /* Note that using TYPE_PRECISION here is wrong. We care about the
1641 actual bits, not the (arbitrary) range of the type. */
1642 prec = GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (expr)));
1643 if (prec >= HOST_BITS_PER_WIDE_INT)
1645 int high_value, shift_amount;
1647 shift_amount = prec - HOST_BITS_PER_WIDE_INT;
1649 if (shift_amount > HOST_BITS_PER_WIDE_INT)
1650 /* Can not handle precisions greater than twice the host int size. */
1652 else if (shift_amount == HOST_BITS_PER_WIDE_INT)
1653 /* Shifting by the host word size is undefined according to the ANSI
1654 standard, so we must handle this as a special case. */
1657 high_value = ((HOST_WIDE_INT) 1 << shift_amount) - 1;
1659 return TREE_INT_CST_LOW (expr) == -1
1660 && TREE_INT_CST_HIGH (expr) == high_value;
1663 return TREE_INT_CST_LOW (expr) == ((HOST_WIDE_INT) 1 << prec) - 1;
1666 /* Return 1 if EXPR is an integer constant that is a power of 2 (i.e., has only
1670 integer_pow2p (expr)
1674 HOST_WIDE_INT high, low;
1678 if (TREE_CODE (expr) == COMPLEX_CST
1679 && integer_pow2p (TREE_REALPART (expr))
1680 && integer_zerop (TREE_IMAGPART (expr)))
1683 if (TREE_CODE (expr) != INTEGER_CST || TREE_CONSTANT_OVERFLOW (expr))
1686 prec = (POINTER_TYPE_P (TREE_TYPE (expr))
1687 ? POINTER_SIZE : TYPE_PRECISION (TREE_TYPE (expr)));
1688 high = TREE_INT_CST_HIGH (expr);
1689 low = TREE_INT_CST_LOW (expr);
1691 /* First clear all bits that are beyond the type's precision in case
1692 we've been sign extended. */
1694 if (prec == 2 * HOST_BITS_PER_WIDE_INT)
1696 else if (prec > HOST_BITS_PER_WIDE_INT)
1697 high &= ~((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
1701 if (prec < HOST_BITS_PER_WIDE_INT)
1702 low &= ~((HOST_WIDE_INT) (-1) << prec);
1705 if (high == 0 && low == 0)
1708 return ((high == 0 && (low & (low - 1)) == 0)
1709 || (low == 0 && (high & (high - 1)) == 0));
1712 /* Return the power of two represented by a tree node known to be a
1720 HOST_WIDE_INT high, low;
1724 if (TREE_CODE (expr) == COMPLEX_CST)
1725 return tree_log2 (TREE_REALPART (expr));
1727 prec = (POINTER_TYPE_P (TREE_TYPE (expr))
1728 ? POINTER_SIZE : TYPE_PRECISION (TREE_TYPE (expr)));
1730 high = TREE_INT_CST_HIGH (expr);
1731 low = TREE_INT_CST_LOW (expr);
1733 /* First clear all bits that are beyond the type's precision in case
1734 we've been sign extended. */
1736 if (prec == 2 * HOST_BITS_PER_WIDE_INT)
1738 else if (prec > HOST_BITS_PER_WIDE_INT)
1739 high &= ~((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
1743 if (prec < HOST_BITS_PER_WIDE_INT)
1744 low &= ~((HOST_WIDE_INT) (-1) << prec);
1747 return (high != 0 ? HOST_BITS_PER_WIDE_INT + exact_log2 (high)
1748 : exact_log2 (low));
1751 /* Return 1 if EXPR is the real constant zero. */
1759 return ((TREE_CODE (expr) == REAL_CST
1760 && ! TREE_CONSTANT_OVERFLOW (expr)
1761 && REAL_VALUES_EQUAL (TREE_REAL_CST (expr), dconst0))
1762 || (TREE_CODE (expr) == COMPLEX_CST
1763 && real_zerop (TREE_REALPART (expr))
1764 && real_zerop (TREE_IMAGPART (expr))));
1767 /* Return 1 if EXPR is the real constant one in real or complex form. */
1775 return ((TREE_CODE (expr) == REAL_CST
1776 && ! TREE_CONSTANT_OVERFLOW (expr)
1777 && REAL_VALUES_EQUAL (TREE_REAL_CST (expr), dconst1))
1778 || (TREE_CODE (expr) == COMPLEX_CST
1779 && real_onep (TREE_REALPART (expr))
1780 && real_zerop (TREE_IMAGPART (expr))));
1783 /* Return 1 if EXPR is the real constant two. */
1791 return ((TREE_CODE (expr) == REAL_CST
1792 && ! TREE_CONSTANT_OVERFLOW (expr)
1793 && REAL_VALUES_EQUAL (TREE_REAL_CST (expr), dconst2))
1794 || (TREE_CODE (expr) == COMPLEX_CST
1795 && real_twop (TREE_REALPART (expr))
1796 && real_zerop (TREE_IMAGPART (expr))));
1799 /* Nonzero if EXP is a constant or a cast of a constant. */
1802 really_constant_p (exp)
1805 /* This is not quite the same as STRIP_NOPS. It does more. */
1806 while (TREE_CODE (exp) == NOP_EXPR
1807 || TREE_CODE (exp) == CONVERT_EXPR
1808 || TREE_CODE (exp) == NON_LVALUE_EXPR)
1809 exp = TREE_OPERAND (exp, 0);
1810 return TREE_CONSTANT (exp);
1813 /* Return first list element whose TREE_VALUE is ELEM.
1814 Return 0 if ELEM is not in LIST. */
1817 value_member (elem, list)
1822 if (elem == TREE_VALUE (list))
1824 list = TREE_CHAIN (list);
1829 /* Return first list element whose TREE_PURPOSE is ELEM.
1830 Return 0 if ELEM is not in LIST. */
1833 purpose_member (elem, list)
1838 if (elem == TREE_PURPOSE (list))
1840 list = TREE_CHAIN (list);
1845 /* Return first list element whose BINFO_TYPE is ELEM.
1846 Return 0 if ELEM is not in LIST. */
1849 binfo_member (elem, list)
1854 if (elem == BINFO_TYPE (list))
1856 list = TREE_CHAIN (list);
1861 /* Return nonzero if ELEM is part of the chain CHAIN. */
1864 chain_member (elem, chain)
1871 chain = TREE_CHAIN (chain);
1877 /* Return nonzero if ELEM is equal to TREE_VALUE (CHAIN) for any piece of
1879 /* ??? This function was added for machine specific attributes but is no
1880 longer used. It could be deleted if we could confirm all front ends
1884 chain_member_value (elem, chain)
1889 if (elem == TREE_VALUE (chain))
1891 chain = TREE_CHAIN (chain);
1897 /* Return nonzero if ELEM is equal to TREE_PURPOSE (CHAIN)
1898 for any piece of chain CHAIN. */
1899 /* ??? This function was added for machine specific attributes but is no
1900 longer used. It could be deleted if we could confirm all front ends
1904 chain_member_purpose (elem, chain)
1909 if (elem == TREE_PURPOSE (chain))
1911 chain = TREE_CHAIN (chain);
1917 /* Return the length of a chain of nodes chained through TREE_CHAIN.
1918 We expect a null pointer to mark the end of the chain.
1919 This is the Lisp primitive `length'. */
1926 register int len = 0;
1928 for (tail = t; tail; tail = TREE_CHAIN (tail))
1934 /* Concatenate two chains of nodes (chained through TREE_CHAIN)
1935 by modifying the last node in chain 1 to point to chain 2.
1936 This is the Lisp primitive `nconc'. */
1948 for (t1 = op1; TREE_CHAIN (t1); t1 = TREE_CHAIN (t1))
1950 TREE_CHAIN (t1) = op2;
1951 for (t2 = op2; t2; t2 = TREE_CHAIN (t2))
1953 abort (); /* Circularity created. */
1959 /* Return the last node in a chain of nodes (chained through TREE_CHAIN). */
1963 register tree chain;
1967 while ((next = TREE_CHAIN (chain)))
1972 /* Reverse the order of elements in the chain T,
1973 and return the new head of the chain (old last element). */
1979 register tree prev = 0, decl, next;
1980 for (decl = t; decl; decl = next)
1982 next = TREE_CHAIN (decl);
1983 TREE_CHAIN (decl) = prev;
1989 /* Given a chain CHAIN of tree nodes,
1990 construct and return a list of those nodes. */
1996 tree result = NULL_TREE;
1997 tree in_tail = chain;
1998 tree out_tail = NULL_TREE;
2002 tree next = tree_cons (NULL_TREE, in_tail, NULL_TREE);
2004 TREE_CHAIN (out_tail) = next;
2008 in_tail = TREE_CHAIN (in_tail);
2014 /* Return a newly created TREE_LIST node whose
2015 purpose and value fields are PARM and VALUE. */
2018 build_tree_list (parm, value)
2021 register tree t = make_node (TREE_LIST);
2022 TREE_PURPOSE (t) = parm;
2023 TREE_VALUE (t) = value;
2027 /* Similar, but build on the temp_decl_obstack. */
2030 build_decl_list (parm, value)
2034 register struct obstack *ambient_obstack = current_obstack;
2035 current_obstack = &temp_decl_obstack;
2036 node = build_tree_list (parm, value);
2037 current_obstack = ambient_obstack;
2041 /* Similar, but build on the expression_obstack. */
2044 build_expr_list (parm, value)
2048 register struct obstack *ambient_obstack = current_obstack;
2049 current_obstack = expression_obstack;
2050 node = build_tree_list (parm, value);
2051 current_obstack = ambient_obstack;
2055 /* Return a newly created TREE_LIST node whose
2056 purpose and value fields are PARM and VALUE
2057 and whose TREE_CHAIN is CHAIN. */
2060 tree_cons (purpose, value, chain)
2061 tree purpose, value, chain;
2064 register tree node = make_node (TREE_LIST);
2067 register tree node = (tree) obstack_alloc (current_obstack, sizeof (struct tree_list));
2068 #ifdef GATHER_STATISTICS
2069 tree_node_counts[(int)x_kind]++;
2070 tree_node_sizes[(int)x_kind] += sizeof (struct tree_list);
2073 for (i = (sizeof (struct tree_common) / sizeof (int)) - 1; i >= 0; i--)
2074 ((int *) node)[i] = 0;
2076 TREE_SET_CODE (node, TREE_LIST);
2077 if (current_obstack == &permanent_obstack)
2078 TREE_PERMANENT (node) = 1;
2081 TREE_CHAIN (node) = chain;
2082 TREE_PURPOSE (node) = purpose;
2083 TREE_VALUE (node) = value;
2087 /* Similar, but build on the temp_decl_obstack. */
2090 decl_tree_cons (purpose, value, chain)
2091 tree purpose, value, chain;
2094 register struct obstack *ambient_obstack = current_obstack;
2095 current_obstack = &temp_decl_obstack;
2096 node = tree_cons (purpose, value, chain);
2097 current_obstack = ambient_obstack;
2101 /* Similar, but build on the expression_obstack. */
2104 expr_tree_cons (purpose, value, chain)
2105 tree purpose, value, chain;
2108 register struct obstack *ambient_obstack = current_obstack;
2109 current_obstack = expression_obstack;
2110 node = tree_cons (purpose, value, chain);
2111 current_obstack = ambient_obstack;
2115 /* Same as `tree_cons' but make a permanent object. */
2118 perm_tree_cons (purpose, value, chain)
2119 tree purpose, value, chain;
2122 register struct obstack *ambient_obstack = current_obstack;
2123 current_obstack = &permanent_obstack;
2125 node = tree_cons (purpose, value, chain);
2126 current_obstack = ambient_obstack;
2130 /* Same as `tree_cons', but make this node temporary, regardless. */
2133 temp_tree_cons (purpose, value, chain)
2134 tree purpose, value, chain;
2137 register struct obstack *ambient_obstack = current_obstack;
2138 current_obstack = &temporary_obstack;
2140 node = tree_cons (purpose, value, chain);
2141 current_obstack = ambient_obstack;
2145 /* Same as `tree_cons', but save this node if the function's RTL is saved. */
2148 saveable_tree_cons (purpose, value, chain)
2149 tree purpose, value, chain;
2152 register struct obstack *ambient_obstack = current_obstack;
2153 current_obstack = saveable_obstack;
2155 node = tree_cons (purpose, value, chain);
2156 current_obstack = ambient_obstack;
2160 /* Return the size nominally occupied by an object of type TYPE
2161 when it resides in memory. The value is measured in units of bytes,
2162 and its data type is that normally used for type sizes
2163 (which is the first type created by make_signed_type or
2164 make_unsigned_type). */
2167 size_in_bytes (type)
2172 if (type == error_mark_node)
2173 return integer_zero_node;
2175 type = TYPE_MAIN_VARIANT (type);
2176 t = TYPE_SIZE_UNIT (type);
2179 incomplete_type_error (NULL_TREE, type);
2180 return integer_zero_node;
2182 if (TREE_CODE (t) == INTEGER_CST)
2183 force_fit_type (t, 0);
2188 /* Return the size of TYPE (in bytes) as a wide integer
2189 or return -1 if the size can vary or is larger than an integer. */
2192 int_size_in_bytes (type)
2197 if (type == error_mark_node)
2200 type = TYPE_MAIN_VARIANT (type);
2201 t = TYPE_SIZE_UNIT (type);
2203 || TREE_CODE (t) != INTEGER_CST
2204 || TREE_INT_CST_HIGH (t) != 0)
2207 return TREE_INT_CST_LOW (t);
2210 /* Return, as a tree node, the number of elements for TYPE (which is an
2211 ARRAY_TYPE) minus one. This counts only elements of the top array.
2213 Don't let any SAVE_EXPRs escape; if we are called as part of a cleanup
2214 action, they would get unsaved. */
2217 array_type_nelts (type)
2220 tree index_type, min, max;
2222 /* If they did it with unspecified bounds, then we should have already
2223 given an error about it before we got here. */
2224 if (! TYPE_DOMAIN (type))
2225 return error_mark_node;
2227 index_type = TYPE_DOMAIN (type);
2228 min = TYPE_MIN_VALUE (index_type);
2229 max = TYPE_MAX_VALUE (index_type);
2231 if (! TREE_CONSTANT (min))
2234 if (TREE_CODE (min) == SAVE_EXPR)
2235 min = build (RTL_EXPR, TREE_TYPE (TYPE_MIN_VALUE (index_type)), 0,
2236 SAVE_EXPR_RTL (min));
2238 min = TYPE_MIN_VALUE (index_type);
2241 if (! TREE_CONSTANT (max))
2244 if (TREE_CODE (max) == SAVE_EXPR)
2245 max = build (RTL_EXPR, TREE_TYPE (TYPE_MAX_VALUE (index_type)), 0,
2246 SAVE_EXPR_RTL (max));
2248 max = TYPE_MAX_VALUE (index_type);
2251 return (integer_zerop (min)
2253 : fold (build (MINUS_EXPR, TREE_TYPE (max), max, min)));
2256 /* Return nonzero if arg is static -- a reference to an object in
2257 static storage. This is not the same as the C meaning of `static'. */
2263 switch (TREE_CODE (arg))
2266 /* Nested functions aren't static, since taking their address
2267 involves a trampoline. */
2268 return decl_function_context (arg) == 0 || DECL_NO_STATIC_CHAIN (arg);
2270 return TREE_STATIC (arg) || DECL_EXTERNAL (arg);
2273 return TREE_STATIC (arg);
2278 /* If we are referencing a bitfield, we can't evaluate an
2279 ADDR_EXPR at compile time and so it isn't a constant. */
2281 return (! DECL_BIT_FIELD (TREE_OPERAND (arg, 1))
2282 && staticp (TREE_OPERAND (arg, 0)));
2288 /* This case is technically correct, but results in setting
2289 TREE_CONSTANT on ADDR_EXPRs that cannot be evaluated at
2292 return TREE_CONSTANT (TREE_OPERAND (arg, 0));
2296 if (TREE_CODE (TYPE_SIZE (TREE_TYPE (arg))) == INTEGER_CST
2297 && TREE_CODE (TREE_OPERAND (arg, 1)) == INTEGER_CST)
2298 return staticp (TREE_OPERAND (arg, 0));
2305 /* Wrap a SAVE_EXPR around EXPR, if appropriate.
2306 Do this to any expression which may be used in more than one place,
2307 but must be evaluated only once.
2309 Normally, expand_expr would reevaluate the expression each time.
2310 Calling save_expr produces something that is evaluated and recorded
2311 the first time expand_expr is called on it. Subsequent calls to
2312 expand_expr just reuse the recorded value.
2314 The call to expand_expr that generates code that actually computes
2315 the value is the first call *at compile time*. Subsequent calls
2316 *at compile time* generate code to use the saved value.
2317 This produces correct result provided that *at run time* control
2318 always flows through the insns made by the first expand_expr
2319 before reaching the other places where the save_expr was evaluated.
2320 You, the caller of save_expr, must make sure this is so.
2322 Constants, and certain read-only nodes, are returned with no
2323 SAVE_EXPR because that is safe. Expressions containing placeholders
2324 are not touched; see tree.def for an explanation of what these
2331 register tree t = fold (expr);
2333 /* We don't care about whether this can be used as an lvalue in this
2335 while (TREE_CODE (t) == NON_LVALUE_EXPR)
2336 t = TREE_OPERAND (t, 0);
2338 /* If the tree evaluates to a constant, then we don't want to hide that
2339 fact (i.e. this allows further folding, and direct checks for constants).
2340 However, a read-only object that has side effects cannot be bypassed.
2341 Since it is no problem to reevaluate literals, we just return the
2344 if (TREE_CONSTANT (t) || (TREE_READONLY (t) && ! TREE_SIDE_EFFECTS (t))
2345 || TREE_CODE (t) == SAVE_EXPR || TREE_CODE (t) == ERROR_MARK)
2348 /* If T contains a PLACEHOLDER_EXPR, we must evaluate it each time, since
2349 it means that the size or offset of some field of an object depends on
2350 the value within another field.
2352 Note that it must not be the case that T contains both a PLACEHOLDER_EXPR
2353 and some variable since it would then need to be both evaluated once and
2354 evaluated more than once. Front-ends must assure this case cannot
2355 happen by surrounding any such subexpressions in their own SAVE_EXPR
2356 and forcing evaluation at the proper time. */
2357 if (contains_placeholder_p (t))
2360 t = build (SAVE_EXPR, TREE_TYPE (expr), t, current_function_decl, NULL_TREE);
2362 /* This expression might be placed ahead of a jump to ensure that the
2363 value was computed on both sides of the jump. So make sure it isn't
2364 eliminated as dead. */
2365 TREE_SIDE_EFFECTS (t) = 1;
2369 /* Arrange for an expression to be expanded multiple independent
2370 times. This is useful for cleanup actions, as the backend can
2371 expand them multiple times in different places. */
2379 /* If this is already protected, no sense in protecting it again. */
2380 if (TREE_CODE (expr) == UNSAVE_EXPR)
2383 t = build1 (UNSAVE_EXPR, TREE_TYPE (expr), expr);
2384 TREE_SIDE_EFFECTS (t) = TREE_SIDE_EFFECTS (expr);
2388 /* Returns the index of the first non-tree operand for CODE, or the number
2389 of operands if all are trees. */
2393 enum tree_code code;
2403 case WITH_CLEANUP_EXPR:
2404 /* Should be defined to be 2. */
2406 case METHOD_CALL_EXPR:
2409 return tree_code_length [(int) code];
2413 /* Modify a tree in place so that all the evaluate only once things
2414 are cleared out. Return the EXPR given. */
2417 unsave_expr_now (expr)
2420 enum tree_code code;
2424 if (expr == NULL_TREE)
2427 code = TREE_CODE (expr);
2428 first_rtl = first_rtl_op (code);
2432 SAVE_EXPR_RTL (expr) = 0;
2436 TREE_OPERAND (expr, 1) = TREE_OPERAND (expr, 3);
2437 TREE_OPERAND (expr, 3) = NULL_TREE;
2441 /* I don't yet know how to emit a sequence multiple times. */
2442 if (RTL_EXPR_SEQUENCE (expr) != 0)
2447 CALL_EXPR_RTL (expr) = 0;
2448 if (TREE_OPERAND (expr, 1)
2449 && TREE_CODE (TREE_OPERAND (expr, 1)) == TREE_LIST)
2451 tree exp = TREE_OPERAND (expr, 1);
2454 unsave_expr_now (TREE_VALUE (exp));
2455 exp = TREE_CHAIN (exp);
2464 switch (TREE_CODE_CLASS (code))
2466 case 'c': /* a constant */
2467 case 't': /* a type node */
2468 case 'x': /* something random, like an identifier or an ERROR_MARK. */
2469 case 'd': /* A decl node */
2470 case 'b': /* A block node */
2473 case 'e': /* an expression */
2474 case 'r': /* a reference */
2475 case 's': /* an expression with side effects */
2476 case '<': /* a comparison expression */
2477 case '2': /* a binary arithmetic expression */
2478 case '1': /* a unary arithmetic expression */
2479 for (i = first_rtl - 1; i >= 0; i--)
2480 unsave_expr_now (TREE_OPERAND (expr, i));
2488 /* Return 1 if EXP contains a PLACEHOLDER_EXPR; i.e., if it represents a size
2489 or offset that depends on a field within a record. */
2492 contains_placeholder_p (exp)
2495 register enum tree_code code = TREE_CODE (exp);
2498 /* If we have a WITH_RECORD_EXPR, it "cancels" any PLACEHOLDER_EXPR
2499 in it since it is supplying a value for it. */
2500 if (code == WITH_RECORD_EXPR)
2502 else if (code == PLACEHOLDER_EXPR)
2505 switch (TREE_CODE_CLASS (code))
2508 /* Don't look at any PLACEHOLDER_EXPRs that might be in index or bit
2509 position computations since they will be converted into a
2510 WITH_RECORD_EXPR involving the reference, which will assume
2511 here will be valid. */
2512 return contains_placeholder_p (TREE_OPERAND (exp, 0));
2515 if (code == TREE_LIST)
2516 return (contains_placeholder_p (TREE_VALUE (exp))
2517 || (TREE_CHAIN (exp) != 0
2518 && contains_placeholder_p (TREE_CHAIN (exp))));
2527 /* Ignoring the first operand isn't quite right, but works best. */
2528 return contains_placeholder_p (TREE_OPERAND (exp, 1));
2535 return (contains_placeholder_p (TREE_OPERAND (exp, 0))
2536 || contains_placeholder_p (TREE_OPERAND (exp, 1))
2537 || contains_placeholder_p (TREE_OPERAND (exp, 2)));
2540 /* If we already know this doesn't have a placeholder, don't
2542 if (SAVE_EXPR_NOPLACEHOLDER (exp) || SAVE_EXPR_RTL (exp) != 0)
2545 SAVE_EXPR_NOPLACEHOLDER (exp) = 1;
2546 result = contains_placeholder_p (TREE_OPERAND (exp, 0));
2548 SAVE_EXPR_NOPLACEHOLDER (exp) = 0;
2553 return (TREE_OPERAND (exp, 1) != 0
2554 && contains_placeholder_p (TREE_OPERAND (exp, 1)));
2560 switch (tree_code_length[(int) code])
2563 return contains_placeholder_p (TREE_OPERAND (exp, 0));
2565 return (contains_placeholder_p (TREE_OPERAND (exp, 0))
2566 || contains_placeholder_p (TREE_OPERAND (exp, 1)));
2577 /* Return 1 if EXP contains any expressions that produce cleanups for an
2578 outer scope to deal with. Used by fold. */
2586 if (! TREE_SIDE_EFFECTS (exp))
2589 switch (TREE_CODE (exp))
2592 case WITH_CLEANUP_EXPR:
2595 case CLEANUP_POINT_EXPR:
2599 for (exp = TREE_OPERAND (exp, 1); exp; exp = TREE_CHAIN (exp))
2601 cmp = has_cleanups (TREE_VALUE (exp));
2611 /* This general rule works for most tree codes. All exceptions should be
2612 handled above. If this is a language-specific tree code, we can't
2613 trust what might be in the operand, so say we don't know
2615 if ((int) TREE_CODE (exp) >= (int) LAST_AND_UNUSED_TREE_CODE)
2618 nops = first_rtl_op (TREE_CODE (exp));
2619 for (i = 0; i < nops; i++)
2620 if (TREE_OPERAND (exp, i) != 0)
2622 int type = TREE_CODE_CLASS (TREE_CODE (TREE_OPERAND (exp, i)));
2623 if (type == 'e' || type == '<' || type == '1' || type == '2'
2624 || type == 'r' || type == 's')
2626 cmp = has_cleanups (TREE_OPERAND (exp, i));
2635 /* Given a tree EXP, a FIELD_DECL F, and a replacement value R,
2636 return a tree with all occurrences of references to F in a
2637 PLACEHOLDER_EXPR replaced by R. Note that we assume here that EXP
2638 contains only arithmetic expressions or a CALL_EXPR with a
2639 PLACEHOLDER_EXPR occurring only in its arglist. */
2642 substitute_in_expr (exp, f, r)
2647 enum tree_code code = TREE_CODE (exp);
2652 switch (TREE_CODE_CLASS (code))
2659 if (code == PLACEHOLDER_EXPR)
2661 else if (code == TREE_LIST)
2663 op0 = (TREE_CHAIN (exp) == 0
2664 ? 0 : substitute_in_expr (TREE_CHAIN (exp), f, r));
2665 op1 = substitute_in_expr (TREE_VALUE (exp), f, r);
2666 if (op0 == TREE_CHAIN (exp) && op1 == TREE_VALUE (exp))
2669 return tree_cons (TREE_PURPOSE (exp), op1, op0);
2678 switch (tree_code_length[(int) code])
2681 op0 = substitute_in_expr (TREE_OPERAND (exp, 0), f, r);
2682 if (op0 == TREE_OPERAND (exp, 0))
2685 new = fold (build1 (code, TREE_TYPE (exp), op0));
2689 /* An RTL_EXPR cannot contain a PLACEHOLDER_EXPR; a CONSTRUCTOR
2690 could, but we don't support it. */
2691 if (code == RTL_EXPR)
2693 else if (code == CONSTRUCTOR)
2696 op0 = substitute_in_expr (TREE_OPERAND (exp, 0), f, r);
2697 op1 = substitute_in_expr (TREE_OPERAND (exp, 1), f, r);
2698 if (op0 == TREE_OPERAND (exp, 0) && op1 == TREE_OPERAND (exp, 1))
2701 new = fold (build (code, TREE_TYPE (exp), op0, op1));
2705 /* It cannot be that anything inside a SAVE_EXPR contains a
2706 PLACEHOLDER_EXPR. */
2707 if (code == SAVE_EXPR)
2710 else if (code == CALL_EXPR)
2712 op1 = substitute_in_expr (TREE_OPERAND (exp, 1), f, r);
2713 if (op1 == TREE_OPERAND (exp, 1))
2716 return build (code, TREE_TYPE (exp),
2717 TREE_OPERAND (exp, 0), op1, NULL_TREE);
2720 else if (code != COND_EXPR)
2723 op0 = substitute_in_expr (TREE_OPERAND (exp, 0), f, r);
2724 op1 = substitute_in_expr (TREE_OPERAND (exp, 1), f, r);
2725 op2 = substitute_in_expr (TREE_OPERAND (exp, 2), f, r);
2726 if (op0 == TREE_OPERAND (exp, 0) && op1 == TREE_OPERAND (exp, 1)
2727 && op2 == TREE_OPERAND (exp, 2))
2730 new = fold (build (code, TREE_TYPE (exp), op0, op1, op2));
2743 /* If this expression is getting a value from a PLACEHOLDER_EXPR
2744 and it is the right field, replace it with R. */
2745 for (inner = TREE_OPERAND (exp, 0);
2746 TREE_CODE_CLASS (TREE_CODE (inner)) == 'r';
2747 inner = TREE_OPERAND (inner, 0))
2749 if (TREE_CODE (inner) == PLACEHOLDER_EXPR
2750 && TREE_OPERAND (exp, 1) == f)
2753 /* If this expression hasn't been completed let, leave it
2755 if (TREE_CODE (inner) == PLACEHOLDER_EXPR
2756 && TREE_TYPE (inner) == 0)
2759 op0 = substitute_in_expr (TREE_OPERAND (exp, 0), f, r);
2760 if (op0 == TREE_OPERAND (exp, 0))
2763 new = fold (build (code, TREE_TYPE (exp), op0,
2764 TREE_OPERAND (exp, 1)));
2768 op0 = substitute_in_expr (TREE_OPERAND (exp, 0), f, r);
2769 op1 = substitute_in_expr (TREE_OPERAND (exp, 1), f, r);
2770 op2 = substitute_in_expr (TREE_OPERAND (exp, 2), f, r);
2771 if (op0 == TREE_OPERAND (exp, 0) && op1 == TREE_OPERAND (exp, 1)
2772 && op2 == TREE_OPERAND (exp, 2))
2775 new = fold (build (code, TREE_TYPE (exp), op0, op1, op2));
2780 op0 = substitute_in_expr (TREE_OPERAND (exp, 0), f, r);
2781 if (op0 == TREE_OPERAND (exp, 0))
2784 new = fold (build1 (code, TREE_TYPE (exp), op0));
2796 TREE_READONLY (new) = TREE_READONLY (exp);
2800 /* Stabilize a reference so that we can use it any number of times
2801 without causing its operands to be evaluated more than once.
2802 Returns the stabilized reference. This works by means of save_expr,
2803 so see the caveats in the comments about save_expr.
2805 Also allows conversion expressions whose operands are references.
2806 Any other kind of expression is returned unchanged. */
2809 stabilize_reference (ref)
2812 register tree result;
2813 register enum tree_code code = TREE_CODE (ref);
2820 /* No action is needed in this case. */
2826 case FIX_TRUNC_EXPR:
2827 case FIX_FLOOR_EXPR:
2828 case FIX_ROUND_EXPR:
2830 result = build_nt (code, stabilize_reference (TREE_OPERAND (ref, 0)));
2834 result = build_nt (INDIRECT_REF,
2835 stabilize_reference_1 (TREE_OPERAND (ref, 0)));
2839 result = build_nt (COMPONENT_REF,
2840 stabilize_reference (TREE_OPERAND (ref, 0)),
2841 TREE_OPERAND (ref, 1));
2845 result = build_nt (BIT_FIELD_REF,
2846 stabilize_reference (TREE_OPERAND (ref, 0)),
2847 stabilize_reference_1 (TREE_OPERAND (ref, 1)),
2848 stabilize_reference_1 (TREE_OPERAND (ref, 2)));
2852 result = build_nt (ARRAY_REF,
2853 stabilize_reference (TREE_OPERAND (ref, 0)),
2854 stabilize_reference_1 (TREE_OPERAND (ref, 1)));
2858 /* We cannot wrap the first expression in a SAVE_EXPR, as then
2859 it wouldn't be ignored. This matters when dealing with
2861 return stabilize_reference_1 (ref);
2864 result = build1 (INDIRECT_REF, TREE_TYPE (ref),
2865 save_expr (build1 (ADDR_EXPR,
2866 build_pointer_type (TREE_TYPE (ref)),
2871 /* If arg isn't a kind of lvalue we recognize, make no change.
2872 Caller should recognize the error for an invalid lvalue. */
2877 return error_mark_node;
2880 TREE_TYPE (result) = TREE_TYPE (ref);
2881 TREE_READONLY (result) = TREE_READONLY (ref);
2882 TREE_SIDE_EFFECTS (result) = TREE_SIDE_EFFECTS (ref);
2883 TREE_THIS_VOLATILE (result) = TREE_THIS_VOLATILE (ref);
2884 TREE_RAISES (result) = TREE_RAISES (ref);
2889 /* Subroutine of stabilize_reference; this is called for subtrees of
2890 references. Any expression with side-effects must be put in a SAVE_EXPR
2891 to ensure that it is only evaluated once.
2893 We don't put SAVE_EXPR nodes around everything, because assigning very
2894 simple expressions to temporaries causes us to miss good opportunities
2895 for optimizations. Among other things, the opportunity to fold in the
2896 addition of a constant into an addressing mode often gets lost, e.g.
2897 "y[i+1] += x;". In general, we take the approach that we should not make
2898 an assignment unless we are forced into it - i.e., that any non-side effect
2899 operator should be allowed, and that cse should take care of coalescing
2900 multiple utterances of the same expression should that prove fruitful. */
2903 stabilize_reference_1 (e)
2906 register tree result;
2907 register enum tree_code code = TREE_CODE (e);
2909 /* We cannot ignore const expressions because it might be a reference
2910 to a const array but whose index contains side-effects. But we can
2911 ignore things that are actual constant or that already have been
2912 handled by this function. */
2914 if (TREE_CONSTANT (e) || code == SAVE_EXPR)
2917 switch (TREE_CODE_CLASS (code))
2927 /* If the expression has side-effects, then encase it in a SAVE_EXPR
2928 so that it will only be evaluated once. */
2929 /* The reference (r) and comparison (<) classes could be handled as
2930 below, but it is generally faster to only evaluate them once. */
2931 if (TREE_SIDE_EFFECTS (e))
2932 return save_expr (e);
2936 /* Constants need no processing. In fact, we should never reach
2941 /* Division is slow and tends to be compiled with jumps,
2942 especially the division by powers of 2 that is often
2943 found inside of an array reference. So do it just once. */
2944 if (code == TRUNC_DIV_EXPR || code == TRUNC_MOD_EXPR
2945 || code == FLOOR_DIV_EXPR || code == FLOOR_MOD_EXPR
2946 || code == CEIL_DIV_EXPR || code == CEIL_MOD_EXPR
2947 || code == ROUND_DIV_EXPR || code == ROUND_MOD_EXPR)
2948 return save_expr (e);
2949 /* Recursively stabilize each operand. */
2950 result = build_nt (code, stabilize_reference_1 (TREE_OPERAND (e, 0)),
2951 stabilize_reference_1 (TREE_OPERAND (e, 1)));
2955 /* Recursively stabilize each operand. */
2956 result = build_nt (code, stabilize_reference_1 (TREE_OPERAND (e, 0)));
2963 TREE_TYPE (result) = TREE_TYPE (e);
2964 TREE_READONLY (result) = TREE_READONLY (e);
2965 TREE_SIDE_EFFECTS (result) = TREE_SIDE_EFFECTS (e);
2966 TREE_THIS_VOLATILE (result) = TREE_THIS_VOLATILE (e);
2967 TREE_RAISES (result) = TREE_RAISES (e);
2972 /* Low-level constructors for expressions. */
2974 /* Build an expression of code CODE, data type TYPE,
2975 and operands as specified by the arguments ARG1 and following arguments.
2976 Expressions and reference nodes can be created this way.
2977 Constants, decls, types and misc nodes cannot be. */
2980 build VPROTO((enum tree_code code, tree tt, ...))
2983 enum tree_code code;
2988 register int length;
2994 code = va_arg (p, enum tree_code);
2995 tt = va_arg (p, tree);
2998 t = make_node (code);
2999 length = tree_code_length[(int) code];
3004 /* This is equivalent to the loop below, but faster. */
3005 register tree arg0 = va_arg (p, tree);
3006 register tree arg1 = va_arg (p, tree);
3007 TREE_OPERAND (t, 0) = arg0;
3008 TREE_OPERAND (t, 1) = arg1;
3009 if ((arg0 && TREE_SIDE_EFFECTS (arg0))
3010 || (arg1 && TREE_SIDE_EFFECTS (arg1)))
3011 TREE_SIDE_EFFECTS (t) = 1;
3013 = (arg0 && TREE_RAISES (arg0)) || (arg1 && TREE_RAISES (arg1));
3015 else if (length == 1)
3017 register tree arg0 = va_arg (p, tree);
3019 /* Call build1 for this! */
3020 if (TREE_CODE_CLASS (code) != 's')
3022 TREE_OPERAND (t, 0) = arg0;
3023 if (arg0 && TREE_SIDE_EFFECTS (arg0))
3024 TREE_SIDE_EFFECTS (t) = 1;
3025 TREE_RAISES (t) = (arg0 && TREE_RAISES (arg0));
3029 for (i = 0; i < length; i++)
3031 register tree operand = va_arg (p, tree);
3032 TREE_OPERAND (t, i) = operand;
3035 if (TREE_SIDE_EFFECTS (operand))
3036 TREE_SIDE_EFFECTS (t) = 1;
3037 if (TREE_RAISES (operand))
3038 TREE_RAISES (t) = 1;
3046 /* Same as above, but only builds for unary operators.
3047 Saves lions share of calls to `build'; cuts down use
3048 of varargs, which is expensive for RISC machines. */
3051 build1 (code, type, node)
3052 enum tree_code code;
3056 register struct obstack *obstack = expression_obstack;
3057 register int i, length;
3058 #ifdef GATHER_STATISTICS
3059 register tree_node_kind kind;
3063 #ifdef GATHER_STATISTICS
3064 if (TREE_CODE_CLASS (code) == 'r')
3070 length = sizeof (struct tree_exp);
3072 t = (tree) obstack_alloc (obstack, length);
3074 #ifdef GATHER_STATISTICS
3075 tree_node_counts[(int)kind]++;
3076 tree_node_sizes[(int)kind] += length;
3079 for (i = (length / sizeof (int)) - 1; i >= 0; i--)
3082 TREE_TYPE (t) = type;
3083 TREE_SET_CODE (t, code);
3085 if (obstack == &permanent_obstack)
3086 TREE_PERMANENT (t) = 1;
3088 TREE_OPERAND (t, 0) = node;
3091 if (TREE_SIDE_EFFECTS (node))
3092 TREE_SIDE_EFFECTS (t) = 1;
3093 if (TREE_RAISES (node))
3094 TREE_RAISES (t) = 1;
3100 /* Similar except don't specify the TREE_TYPE
3101 and leave the TREE_SIDE_EFFECTS as 0.
3102 It is permissible for arguments to be null,
3103 or even garbage if their values do not matter. */
3106 build_nt VPROTO((enum tree_code code, ...))
3109 enum tree_code code;
3113 register int length;
3119 code = va_arg (p, enum tree_code);
3122 t = make_node (code);
3123 length = tree_code_length[(int) code];
3125 for (i = 0; i < length; i++)
3126 TREE_OPERAND (t, i) = va_arg (p, tree);
3132 /* Similar to `build_nt', except we build
3133 on the temp_decl_obstack, regardless. */
3136 build_parse_node VPROTO((enum tree_code code, ...))
3139 enum tree_code code;
3141 register struct obstack *ambient_obstack = expression_obstack;
3144 register int length;
3150 code = va_arg (p, enum tree_code);
3153 expression_obstack = &temp_decl_obstack;
3155 t = make_node (code);
3156 length = tree_code_length[(int) code];
3158 for (i = 0; i < length; i++)
3159 TREE_OPERAND (t, i) = va_arg (p, tree);
3162 expression_obstack = ambient_obstack;
3167 /* Commented out because this wants to be done very
3168 differently. See cp-lex.c. */
3170 build_op_identifier (op1, op2)
3173 register tree t = make_node (OP_IDENTIFIER);
3174 TREE_PURPOSE (t) = op1;
3175 TREE_VALUE (t) = op2;
3180 /* Create a DECL_... node of code CODE, name NAME and data type TYPE.
3181 We do NOT enter this node in any sort of symbol table.
3183 layout_decl is used to set up the decl's storage layout.
3184 Other slots are initialized to 0 or null pointers. */
3187 build_decl (code, name, type)
3188 enum tree_code code;
3193 t = make_node (code);
3195 /* if (type == error_mark_node)
3196 type = integer_type_node; */
3197 /* That is not done, deliberately, so that having error_mark_node
3198 as the type can suppress useless errors in the use of this variable. */
3200 DECL_NAME (t) = name;
3201 DECL_ASSEMBLER_NAME (t) = name;
3202 TREE_TYPE (t) = type;
3204 if (code == VAR_DECL || code == PARM_DECL || code == RESULT_DECL)
3206 else if (code == FUNCTION_DECL)
3207 DECL_MODE (t) = FUNCTION_MODE;
3212 /* BLOCK nodes are used to represent the structure of binding contours
3213 and declarations, once those contours have been exited and their contents
3214 compiled. This information is used for outputting debugging info. */
3217 build_block (vars, tags, subblocks, supercontext, chain)
3218 tree vars, tags, subblocks, supercontext, chain;
3220 register tree block = make_node (BLOCK);
3221 BLOCK_VARS (block) = vars;
3222 BLOCK_TYPE_TAGS (block) = tags;
3223 BLOCK_SUBBLOCKS (block) = subblocks;
3224 BLOCK_SUPERCONTEXT (block) = supercontext;
3225 BLOCK_CHAIN (block) = chain;
3229 /* EXPR_WITH_FILE_LOCATION are used to keep track of the exact
3230 location where an expression or an identifier were encountered. It
3231 is necessary for languages where the frontend parser will handle
3232 recursively more than one file (Java is one of them). */
3235 build_expr_wfl (node, file, line, col)
3240 static char *last_file = 0;
3241 static tree last_filenode = NULL_TREE;
3242 register tree wfl = make_node (EXPR_WITH_FILE_LOCATION);
3244 EXPR_WFL_NODE (wfl) = node;
3245 EXPR_WFL_SET_LINECOL (wfl, line, col);
3246 if (file != last_file)
3249 last_filenode = file ? get_identifier (file) : NULL_TREE;
3251 EXPR_WFL_FILENAME_NODE (wfl) = last_filenode;
3254 TREE_SIDE_EFFECTS (wfl) = TREE_SIDE_EFFECTS (node);
3255 TREE_TYPE (wfl) = TREE_TYPE (node);
3260 /* Return a declaration like DDECL except that its DECL_MACHINE_ATTRIBUTE
3264 build_decl_attribute_variant (ddecl, attribute)
3265 tree ddecl, attribute;
3267 DECL_MACHINE_ATTRIBUTES (ddecl) = attribute;
3271 /* Return a type like TTYPE except that its TYPE_ATTRIBUTE
3274 Record such modified types already made so we don't make duplicates. */
3277 build_type_attribute_variant (ttype, attribute)
3278 tree ttype, attribute;
3280 if ( ! attribute_list_equal (TYPE_ATTRIBUTES (ttype), attribute))
3282 register int hashcode;
3283 register struct obstack *ambient_obstack = current_obstack;
3286 if (ambient_obstack != &permanent_obstack)
3287 current_obstack = TYPE_OBSTACK (ttype);
3289 ntype = copy_node (ttype);
3290 current_obstack = ambient_obstack;
3292 TYPE_POINTER_TO (ntype) = 0;
3293 TYPE_REFERENCE_TO (ntype) = 0;
3294 TYPE_ATTRIBUTES (ntype) = attribute;
3296 /* Create a new main variant of TYPE. */
3297 TYPE_MAIN_VARIANT (ntype) = ntype;
3298 TYPE_NEXT_VARIANT (ntype) = 0;
3299 TYPE_READONLY (ntype) = TYPE_VOLATILE (ntype) = 0;
3301 hashcode = TYPE_HASH (TREE_CODE (ntype))
3302 + TYPE_HASH (TREE_TYPE (ntype))
3303 + attribute_hash_list (attribute);
3305 switch (TREE_CODE (ntype))
3308 hashcode += TYPE_HASH (TYPE_ARG_TYPES (ntype));
3311 hashcode += TYPE_HASH (TYPE_DOMAIN (ntype));
3314 hashcode += TYPE_HASH (TYPE_MAX_VALUE (ntype));
3317 hashcode += TYPE_HASH (TYPE_PRECISION (ntype));
3323 ntype = type_hash_canon (hashcode, ntype);
3324 ttype = build_type_variant (ntype, TYPE_READONLY (ttype),
3325 TYPE_VOLATILE (ttype));
3331 /* Return a 1 if ATTR_NAME and ATTR_ARGS is valid for either declaration DECL
3332 or type TYPE and 0 otherwise. Validity is determined the configuration
3333 macros VALID_MACHINE_DECL_ATTRIBUTE and VALID_MACHINE_TYPE_ATTRIBUTE. */
3336 valid_machine_attribute (attr_name, attr_args, decl, type)
3337 tree attr_name, attr_args;
3342 #ifdef VALID_MACHINE_DECL_ATTRIBUTE
3343 tree decl_attr_list = decl != 0 ? DECL_MACHINE_ATTRIBUTES (decl) : 0;
3345 #ifdef VALID_MACHINE_TYPE_ATTRIBUTE
3346 tree type_attr_list = TYPE_ATTRIBUTES (type);
3349 if (TREE_CODE (attr_name) != IDENTIFIER_NODE)
3352 #ifdef VALID_MACHINE_DECL_ATTRIBUTE
3354 && VALID_MACHINE_DECL_ATTRIBUTE (decl, decl_attr_list, attr_name, attr_args))
3356 tree attr = lookup_attribute (IDENTIFIER_POINTER (attr_name),
3359 if (attr != NULL_TREE)
3361 /* Override existing arguments. Declarations are unique so we can
3362 modify this in place. */
3363 TREE_VALUE (attr) = attr_args;
3367 decl_attr_list = tree_cons (attr_name, attr_args, decl_attr_list);
3368 decl = build_decl_attribute_variant (decl, decl_attr_list);
3375 #ifdef VALID_MACHINE_TYPE_ATTRIBUTE
3376 if (VALID_MACHINE_TYPE_ATTRIBUTE (type, type_attr_list, attr_name, attr_args))
3378 tree attr = lookup_attribute (IDENTIFIER_POINTER (attr_name),
3381 if (attr != NULL_TREE)
3383 /* Override existing arguments.
3384 ??? This currently works since attribute arguments are not
3385 included in `attribute_hash_list'. Something more complicated
3386 may be needed in the future. */
3387 TREE_VALUE (attr) = attr_args;
3391 type_attr_list = tree_cons (attr_name, attr_args, type_attr_list);
3392 type = build_type_attribute_variant (type, type_attr_list);
3395 TREE_TYPE (decl) = type;
3399 /* Handle putting a type attribute on pointer-to-function-type by putting
3400 the attribute on the function type. */
3401 else if (POINTER_TYPE_P (type)
3402 && TREE_CODE (TREE_TYPE (type)) == FUNCTION_TYPE
3403 && VALID_MACHINE_TYPE_ATTRIBUTE (TREE_TYPE (type), type_attr_list,
3404 attr_name, attr_args))
3406 tree inner_type = TREE_TYPE (type);
3407 tree inner_attr_list = TYPE_ATTRIBUTES (inner_type);
3408 tree attr = lookup_attribute (IDENTIFIER_POINTER (attr_name),
3411 if (attr != NULL_TREE)
3412 TREE_VALUE (attr) = attr_args;
3415 inner_attr_list = tree_cons (attr_name, attr_args, inner_attr_list);
3416 inner_type = build_type_attribute_variant (inner_type,
3421 TREE_TYPE (decl) = build_pointer_type (inner_type);
3430 /* Return non-zero if IDENT is a valid name for attribute ATTR,
3433 We try both `text' and `__text__', ATTR may be either one. */
3434 /* ??? It might be a reasonable simplification to require ATTR to be only
3435 `text'. One might then also require attribute lists to be stored in
3436 their canonicalized form. */
3439 is_attribute_p (attr, ident)
3443 int ident_len, attr_len;
3446 if (TREE_CODE (ident) != IDENTIFIER_NODE)
3449 if (strcmp (attr, IDENTIFIER_POINTER (ident)) == 0)
3452 p = IDENTIFIER_POINTER (ident);
3453 ident_len = strlen (p);
3454 attr_len = strlen (attr);
3456 /* If ATTR is `__text__', IDENT must be `text'; and vice versa. */
3460 || attr[attr_len - 2] != '_'
3461 || attr[attr_len - 1] != '_')
3463 if (ident_len == attr_len - 4
3464 && strncmp (attr + 2, p, attr_len - 4) == 0)
3469 if (ident_len == attr_len + 4
3470 && p[0] == '_' && p[1] == '_'
3471 && p[ident_len - 2] == '_' && p[ident_len - 1] == '_'
3472 && strncmp (attr, p + 2, attr_len) == 0)
3479 /* Given an attribute name and a list of attributes, return a pointer to the
3480 attribute's list element if the attribute is part of the list, or NULL_TREE
3484 lookup_attribute (attr_name, list)
3490 for (l = list; l; l = TREE_CHAIN (l))
3492 if (TREE_CODE (TREE_PURPOSE (l)) != IDENTIFIER_NODE)
3494 if (is_attribute_p (attr_name, TREE_PURPOSE (l)))
3501 /* Return an attribute list that is the union of a1 and a2. */
3504 merge_attributes (a1, a2)
3505 register tree a1, a2;
3509 /* Either one unset? Take the set one. */
3511 if (! (attributes = a1))
3514 /* One that completely contains the other? Take it. */
3516 else if (a2 && ! attribute_list_contained (a1, a2))
3518 if (attribute_list_contained (a2, a1))
3522 /* Pick the longest list, and hang on the other list. */
3523 /* ??? For the moment we punt on the issue of attrs with args. */
3525 if (list_length (a1) < list_length (a2))
3526 attributes = a2, a2 = a1;
3528 for (; a2; a2 = TREE_CHAIN (a2))
3529 if (lookup_attribute (IDENTIFIER_POINTER (TREE_PURPOSE (a2)),
3530 attributes) == NULL_TREE)
3532 a1 = copy_node (a2);
3533 TREE_CHAIN (a1) = attributes;
3541 /* Given types T1 and T2, merge their attributes and return
3545 merge_machine_type_attributes (t1, t2)
3548 #ifdef MERGE_MACHINE_TYPE_ATTRIBUTES
3549 return MERGE_MACHINE_TYPE_ATTRIBUTES (t1, t2);
3551 return merge_attributes (TYPE_ATTRIBUTES (t1),
3552 TYPE_ATTRIBUTES (t2));
3556 /* Given decls OLDDECL and NEWDECL, merge their attributes and return
3560 merge_machine_decl_attributes (olddecl, newdecl)
3561 tree olddecl, newdecl;
3563 #ifdef MERGE_MACHINE_DECL_ATTRIBUTES
3564 return MERGE_MACHINE_DECL_ATTRIBUTES (olddecl, newdecl);
3566 return merge_attributes (DECL_MACHINE_ATTRIBUTES (olddecl),
3567 DECL_MACHINE_ATTRIBUTES (newdecl));
3571 /* Return a type like TYPE except that its TYPE_READONLY is CONSTP
3572 and its TYPE_VOLATILE is VOLATILEP.
3574 Such variant types already made are recorded so that duplicates
3577 A variant types should never be used as the type of an expression.
3578 Always copy the variant information into the TREE_READONLY
3579 and TREE_THIS_VOLATILE of the expression, and then give the expression
3580 as its type the "main variant", the variant whose TYPE_READONLY
3581 and TYPE_VOLATILE are zero. Use TYPE_MAIN_VARIANT to find the
3585 build_type_variant (type, constp, volatilep)
3587 int constp, volatilep;
3591 /* Treat any nonzero argument as 1. */
3593 volatilep = !!volatilep;
3595 /* Search the chain of variants to see if there is already one there just
3596 like the one we need to have. If so, use that existing one. We must
3597 preserve the TYPE_NAME, since there is code that depends on this. */
3599 for (t = TYPE_MAIN_VARIANT (type); t; t = TYPE_NEXT_VARIANT (t))
3600 if (constp == TYPE_READONLY (t) && volatilep == TYPE_VOLATILE (t)
3601 && TYPE_NAME (t) == TYPE_NAME (type))
3604 /* We need a new one. */
3606 t = build_type_copy (type);
3607 TYPE_READONLY (t) = constp;
3608 TYPE_VOLATILE (t) = volatilep;
3613 /* Create a new variant of TYPE, equivalent but distinct.
3614 This is so the caller can modify it. */
3617 build_type_copy (type)
3620 register tree t, m = TYPE_MAIN_VARIANT (type);
3621 register struct obstack *ambient_obstack = current_obstack;
3623 current_obstack = TYPE_OBSTACK (type);
3624 t = copy_node (type);
3625 current_obstack = ambient_obstack;
3627 TYPE_POINTER_TO (t) = 0;
3628 TYPE_REFERENCE_TO (t) = 0;
3630 /* Add this type to the chain of variants of TYPE. */
3631 TYPE_NEXT_VARIANT (t) = TYPE_NEXT_VARIANT (m);
3632 TYPE_NEXT_VARIANT (m) = t;
3637 /* Hashing of types so that we don't make duplicates.
3638 The entry point is `type_hash_canon'. */
3640 /* Each hash table slot is a bucket containing a chain
3641 of these structures. */
3645 struct type_hash *next; /* Next structure in the bucket. */
3646 int hashcode; /* Hash code of this type. */
3647 tree type; /* The type recorded here. */
3650 /* Now here is the hash table. When recording a type, it is added
3651 to the slot whose index is the hash code mod the table size.
3652 Note that the hash table is used for several kinds of types
3653 (function types, array types and array index range types, for now).
3654 While all these live in the same table, they are completely independent,
3655 and the hash code is computed differently for each of these. */
3657 #define TYPE_HASH_SIZE 59
3658 struct type_hash *type_hash_table[TYPE_HASH_SIZE];
3660 /* Compute a hash code for a list of types (chain of TREE_LIST nodes
3661 with types in the TREE_VALUE slots), by adding the hash codes
3662 of the individual types. */
3665 type_hash_list (list)
3668 register int hashcode;
3670 for (hashcode = 0, tail = list; tail; tail = TREE_CHAIN (tail))
3671 hashcode += TYPE_HASH (TREE_VALUE (tail));
3675 /* Look in the type hash table for a type isomorphic to TYPE.
3676 If one is found, return it. Otherwise return 0. */
3679 type_hash_lookup (hashcode, type)
3683 register struct type_hash *h;
3684 for (h = type_hash_table[hashcode % TYPE_HASH_SIZE]; h; h = h->next)
3685 if (h->hashcode == hashcode
3686 && TREE_CODE (h->type) == TREE_CODE (type)
3687 && TREE_TYPE (h->type) == TREE_TYPE (type)
3688 && attribute_list_equal (TYPE_ATTRIBUTES (h->type),
3689 TYPE_ATTRIBUTES (type))
3690 && (TYPE_MAX_VALUE (h->type) == TYPE_MAX_VALUE (type)
3691 || tree_int_cst_equal (TYPE_MAX_VALUE (h->type),
3692 TYPE_MAX_VALUE (type)))
3693 && (TYPE_MIN_VALUE (h->type) == TYPE_MIN_VALUE (type)
3694 || tree_int_cst_equal (TYPE_MIN_VALUE (h->type),
3695 TYPE_MIN_VALUE (type)))
3696 /* Note that TYPE_DOMAIN is TYPE_ARG_TYPES for FUNCTION_TYPE. */
3697 && (TYPE_DOMAIN (h->type) == TYPE_DOMAIN (type)
3698 || (TYPE_DOMAIN (h->type)
3699 && TREE_CODE (TYPE_DOMAIN (h->type)) == TREE_LIST
3700 && TYPE_DOMAIN (type)
3701 && TREE_CODE (TYPE_DOMAIN (type)) == TREE_LIST
3702 && type_list_equal (TYPE_DOMAIN (h->type),
3703 TYPE_DOMAIN (type)))))
3708 /* Add an entry to the type-hash-table
3709 for a type TYPE whose hash code is HASHCODE. */
3712 type_hash_add (hashcode, type)
3716 register struct type_hash *h;
3718 h = (struct type_hash *) oballoc (sizeof (struct type_hash));
3719 h->hashcode = hashcode;
3721 h->next = type_hash_table[hashcode % TYPE_HASH_SIZE];
3722 type_hash_table[hashcode % TYPE_HASH_SIZE] = h;
3725 /* Given TYPE, and HASHCODE its hash code, return the canonical
3726 object for an identical type if one already exists.
3727 Otherwise, return TYPE, and record it as the canonical object
3728 if it is a permanent object.
3730 To use this function, first create a type of the sort you want.
3731 Then compute its hash code from the fields of the type that
3732 make it different from other similar types.
3733 Then call this function and use the value.
3734 This function frees the type you pass in if it is a duplicate. */
3736 /* Set to 1 to debug without canonicalization. Never set by program. */
3737 int debug_no_type_hash = 0;
3740 type_hash_canon (hashcode, type)
3746 if (debug_no_type_hash)
3749 t1 = type_hash_lookup (hashcode, type);
3752 obstack_free (TYPE_OBSTACK (type), type);
3753 #ifdef GATHER_STATISTICS
3754 tree_node_counts[(int)t_kind]--;
3755 tree_node_sizes[(int)t_kind] -= sizeof (struct tree_type);
3760 /* If this is a permanent type, record it for later reuse. */
3761 if (TREE_PERMANENT (type))
3762 type_hash_add (hashcode, type);
3767 /* Compute a hash code for a list of attributes (chain of TREE_LIST nodes
3768 with names in the TREE_PURPOSE slots and args in the TREE_VALUE slots),
3769 by adding the hash codes of the individual attributes. */
3772 attribute_hash_list (list)
3775 register int hashcode;
3777 for (hashcode = 0, tail = list; tail; tail = TREE_CHAIN (tail))
3778 /* ??? Do we want to add in TREE_VALUE too? */
3779 hashcode += TYPE_HASH (TREE_PURPOSE (tail));
3783 /* Given two lists of attributes, return true if list l2 is
3784 equivalent to l1. */
3787 attribute_list_equal (l1, l2)
3790 return attribute_list_contained (l1, l2)
3791 && attribute_list_contained (l2, l1);
3794 /* Given two lists of attributes, return true if list L2 is
3795 completely contained within L1. */
3796 /* ??? This would be faster if attribute names were stored in a canonicalized
3797 form. Otherwise, if L1 uses `foo' and L2 uses `__foo__', the long method
3798 must be used to show these elements are equivalent (which they are). */
3799 /* ??? It's not clear that attributes with arguments will always be handled
3803 attribute_list_contained (l1, l2)
3806 register tree t1, t2;
3808 /* First check the obvious, maybe the lists are identical. */
3812 /* Maybe the lists are similar. */
3813 for (t1 = l1, t2 = l2;
3815 && TREE_PURPOSE (t1) == TREE_PURPOSE (t2)
3816 && TREE_VALUE (t1) == TREE_VALUE (t2);
3817 t1 = TREE_CHAIN (t1), t2 = TREE_CHAIN (t2));
3819 /* Maybe the lists are equal. */
3820 if (t1 == 0 && t2 == 0)
3823 for (; t2; t2 = TREE_CHAIN (t2))
3826 = lookup_attribute (IDENTIFIER_POINTER (TREE_PURPOSE (t2)), l1);
3828 if (attr == NULL_TREE)
3830 if (simple_cst_equal (TREE_VALUE (t2), TREE_VALUE (attr)) != 1)
3837 /* Given two lists of types
3838 (chains of TREE_LIST nodes with types in the TREE_VALUE slots)
3839 return 1 if the lists contain the same types in the same order.
3840 Also, the TREE_PURPOSEs must match. */
3843 type_list_equal (l1, l2)
3846 register tree t1, t2;
3848 for (t1 = l1, t2 = l2; t1 && t2; t1 = TREE_CHAIN (t1), t2 = TREE_CHAIN (t2))
3849 if (TREE_VALUE (t1) != TREE_VALUE (t2)
3850 || (TREE_PURPOSE (t1) != TREE_PURPOSE (t2)
3851 && ! (1 == simple_cst_equal (TREE_PURPOSE (t1), TREE_PURPOSE (t2))
3852 && (TREE_TYPE (TREE_PURPOSE (t1))
3853 == TREE_TYPE (TREE_PURPOSE (t2))))))
3859 /* Nonzero if integer constants T1 and T2
3860 represent the same constant value. */
3863 tree_int_cst_equal (t1, t2)
3868 if (t1 == 0 || t2 == 0)
3870 if (TREE_CODE (t1) == INTEGER_CST
3871 && TREE_CODE (t2) == INTEGER_CST
3872 && TREE_INT_CST_LOW (t1) == TREE_INT_CST_LOW (t2)
3873 && TREE_INT_CST_HIGH (t1) == TREE_INT_CST_HIGH (t2))
3878 /* Nonzero if integer constants T1 and T2 represent values that satisfy <.
3879 The precise way of comparison depends on their data type. */
3882 tree_int_cst_lt (t1, t2)
3888 if (!TREE_UNSIGNED (TREE_TYPE (t1)))
3889 return INT_CST_LT (t1, t2);
3890 return INT_CST_LT_UNSIGNED (t1, t2);
3893 /* Return an indication of the sign of the integer constant T.
3894 The return value is -1 if T < 0, 0 if T == 0, and 1 if T > 0.
3895 Note that -1 will never be returned it T's type is unsigned. */
3898 tree_int_cst_sgn (t)
3901 if (TREE_INT_CST_LOW (t) == 0 && TREE_INT_CST_HIGH (t) == 0)
3903 else if (TREE_UNSIGNED (TREE_TYPE (t)))
3905 else if (TREE_INT_CST_HIGH (t) < 0)
3911 /* Compare two constructor-element-type constants. Return 1 if the lists
3912 are known to be equal; otherwise return 0. */
3915 simple_cst_list_equal (l1, l2)
3918 while (l1 != NULL_TREE && l2 != NULL_TREE)
3920 if (simple_cst_equal (TREE_VALUE (l1), TREE_VALUE (l2)) != 1)
3923 l1 = TREE_CHAIN (l1);
3924 l2 = TREE_CHAIN (l2);
3930 /* Return truthvalue of whether T1 is the same tree structure as T2.
3931 Return 1 if they are the same.
3932 Return 0 if they are understandably different.
3933 Return -1 if either contains tree structure not understood by
3937 simple_cst_equal (t1, t2)
3940 register enum tree_code code1, code2;
3945 if (t1 == 0 || t2 == 0)
3948 code1 = TREE_CODE (t1);
3949 code2 = TREE_CODE (t2);
3951 if (code1 == NOP_EXPR || code1 == CONVERT_EXPR || code1 == NON_LVALUE_EXPR)
3952 if (code2 == NOP_EXPR || code2 == CONVERT_EXPR || code2 == NON_LVALUE_EXPR)
3953 return simple_cst_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
3955 return simple_cst_equal (TREE_OPERAND (t1, 0), t2);
3956 else if (code2 == NOP_EXPR || code2 == CONVERT_EXPR
3957 || code2 == NON_LVALUE_EXPR)
3958 return simple_cst_equal (t1, TREE_OPERAND (t2, 0));
3966 return TREE_INT_CST_LOW (t1) == TREE_INT_CST_LOW (t2)
3967 && TREE_INT_CST_HIGH (t1) == TREE_INT_CST_HIGH (t2);
3970 return REAL_VALUES_IDENTICAL (TREE_REAL_CST (t1), TREE_REAL_CST (t2));
3973 return TREE_STRING_LENGTH (t1) == TREE_STRING_LENGTH (t2)
3974 && !bcmp (TREE_STRING_POINTER (t1), TREE_STRING_POINTER (t2),
3975 TREE_STRING_LENGTH (t1));
3981 return simple_cst_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
3984 cmp = simple_cst_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
3987 return simple_cst_list_equal (TREE_OPERAND (t1, 1), TREE_OPERAND (t2, 1));
3990 /* Special case: if either target is an unallocated VAR_DECL,
3991 it means that it's going to be unified with whatever the
3992 TARGET_EXPR is really supposed to initialize, so treat it
3993 as being equivalent to anything. */
3994 if ((TREE_CODE (TREE_OPERAND (t1, 0)) == VAR_DECL
3995 && DECL_NAME (TREE_OPERAND (t1, 0)) == NULL_TREE
3996 && DECL_RTL (TREE_OPERAND (t1, 0)) == 0)
3997 || (TREE_CODE (TREE_OPERAND (t2, 0)) == VAR_DECL
3998 && DECL_NAME (TREE_OPERAND (t2, 0)) == NULL_TREE
3999 && DECL_RTL (TREE_OPERAND (t2, 0)) == 0))
4002 cmp = simple_cst_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
4005 return simple_cst_equal (TREE_OPERAND (t1, 1), TREE_OPERAND (t2, 1));
4007 case WITH_CLEANUP_EXPR:
4008 cmp = simple_cst_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
4011 return simple_cst_equal (TREE_OPERAND (t1, 2), TREE_OPERAND (t1, 2));
4014 if (TREE_OPERAND (t1, 1) == TREE_OPERAND (t2, 1))
4015 return simple_cst_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
4028 /* This general rule works for most tree codes. All exceptions should be
4029 handled above. If this is a language-specific tree code, we can't
4030 trust what might be in the operand, so say we don't know
4032 if ((int) code1 >= (int) LAST_AND_UNUSED_TREE_CODE)
4035 switch (TREE_CODE_CLASS (code1))
4045 for (i=0; i<tree_code_length[(int) code1]; ++i)
4047 cmp = simple_cst_equal (TREE_OPERAND (t1, i), TREE_OPERAND (t2, i));
4058 /* Constructors for pointer, array and function types.
4059 (RECORD_TYPE, UNION_TYPE and ENUMERAL_TYPE nodes are
4060 constructed by language-dependent code, not here.) */
4062 /* Construct, lay out and return the type of pointers to TO_TYPE.
4063 If such a type has already been constructed, reuse it. */
4066 build_pointer_type (to_type)
4069 register tree t = TYPE_POINTER_TO (to_type);
4071 /* First, if we already have a type for pointers to TO_TYPE, use it. */
4076 /* We need a new one. Put this in the same obstack as TO_TYPE. */
4077 push_obstacks (TYPE_OBSTACK (to_type), TYPE_OBSTACK (to_type));
4078 t = make_node (POINTER_TYPE);
4081 TREE_TYPE (t) = to_type;
4083 /* Record this type as the pointer to TO_TYPE. */
4084 TYPE_POINTER_TO (to_type) = t;
4086 /* Lay out the type. This function has many callers that are concerned
4087 with expression-construction, and this simplifies them all.
4088 Also, it guarantees the TYPE_SIZE is in the same obstack as the type. */
4094 /* Create a type of integers to be the TYPE_DOMAIN of an ARRAY_TYPE.
4095 MAXVAL should be the maximum value in the domain
4096 (one less than the length of the array).
4098 The maximum value that MAXVAL can have is INT_MAX for a HOST_WIDE_INT.
4099 We don't enforce this limit, that is up to caller (e.g. language front end).
4100 The limit exists because the result is a signed type and we don't handle
4101 sizes that use more than one HOST_WIDE_INT. */
4104 build_index_type (maxval)
4107 register tree itype = make_node (INTEGER_TYPE);
4109 TYPE_PRECISION (itype) = TYPE_PRECISION (sizetype);
4110 TYPE_MIN_VALUE (itype) = size_zero_node;
4112 push_obstacks (TYPE_OBSTACK (itype), TYPE_OBSTACK (itype));
4113 TYPE_MAX_VALUE (itype) = convert (sizetype, maxval);
4116 TYPE_MODE (itype) = TYPE_MODE (sizetype);
4117 TYPE_SIZE (itype) = TYPE_SIZE (sizetype);
4118 TYPE_ALIGN (itype) = TYPE_ALIGN (sizetype);
4119 if (TREE_CODE (maxval) == INTEGER_CST)
4121 int maxint = (int) TREE_INT_CST_LOW (maxval);
4122 /* If the domain should be empty, make sure the maxval
4123 remains -1 and is not spoiled by truncation. */
4124 if (INT_CST_LT (maxval, integer_zero_node))
4126 TYPE_MAX_VALUE (itype) = build_int_2 (-1, -1);
4127 TREE_TYPE (TYPE_MAX_VALUE (itype)) = sizetype;
4129 return type_hash_canon (maxint < 0 ? ~maxint : maxint, itype);
4135 /* Create a range of some discrete type TYPE (an INTEGER_TYPE,
4136 ENUMERAL_TYPE, BOOLEAN_TYPE, or CHAR_TYPE), with
4137 low bound LOWVAL and high bound HIGHVAL.
4138 if TYPE==NULL_TREE, sizetype is used. */
4141 build_range_type (type, lowval, highval)
4142 tree type, lowval, highval;
4144 register tree itype = make_node (INTEGER_TYPE);
4146 TREE_TYPE (itype) = type;
4147 if (type == NULL_TREE)
4150 push_obstacks (TYPE_OBSTACK (itype), TYPE_OBSTACK (itype));
4151 TYPE_MIN_VALUE (itype) = convert (type, lowval);
4152 TYPE_MAX_VALUE (itype) = highval ? convert (type, highval) : NULL;
4155 TYPE_PRECISION (itype) = TYPE_PRECISION (type);
4156 TYPE_MODE (itype) = TYPE_MODE (type);
4157 TYPE_SIZE (itype) = TYPE_SIZE (type);
4158 TYPE_ALIGN (itype) = TYPE_ALIGN (type);
4159 if (TREE_CODE (lowval) == INTEGER_CST)
4161 HOST_WIDE_INT lowint, highint;
4164 lowint = TREE_INT_CST_LOW (lowval);
4165 if (highval && TREE_CODE (highval) == INTEGER_CST)
4166 highint = TREE_INT_CST_LOW (highval);
4168 highint = (~(unsigned HOST_WIDE_INT)0) >> 1;
4170 maxint = (int) (highint - lowint);
4171 return type_hash_canon (maxint < 0 ? ~maxint : maxint, itype);
4177 /* Just like build_index_type, but takes lowval and highval instead
4178 of just highval (maxval). */
4181 build_index_2_type (lowval,highval)
4182 tree lowval, highval;
4184 return build_range_type (NULL_TREE, lowval, highval);
4187 /* Return nonzero iff ITYPE1 and ITYPE2 are equal (in the LISP sense).
4188 Needed because when index types are not hashed, equal index types
4189 built at different times appear distinct, even though structurally,
4193 index_type_equal (itype1, itype2)
4194 tree itype1, itype2;
4196 if (TREE_CODE (itype1) != TREE_CODE (itype2))
4198 if (TREE_CODE (itype1) == INTEGER_TYPE)
4200 if (TYPE_PRECISION (itype1) != TYPE_PRECISION (itype2)
4201 || TYPE_MODE (itype1) != TYPE_MODE (itype2)
4202 || simple_cst_equal (TYPE_SIZE (itype1), TYPE_SIZE (itype2)) != 1
4203 || TYPE_ALIGN (itype1) != TYPE_ALIGN (itype2))
4205 if (1 == simple_cst_equal (TYPE_MIN_VALUE (itype1),
4206 TYPE_MIN_VALUE (itype2))
4207 && 1 == simple_cst_equal (TYPE_MAX_VALUE (itype1),
4208 TYPE_MAX_VALUE (itype2)))
4215 /* Construct, lay out and return the type of arrays of elements with ELT_TYPE
4216 and number of elements specified by the range of values of INDEX_TYPE.
4217 If such a type has already been constructed, reuse it. */
4220 build_array_type (elt_type, index_type)
4221 tree elt_type, index_type;
4226 if (TREE_CODE (elt_type) == FUNCTION_TYPE)
4228 error ("arrays of functions are not meaningful");
4229 elt_type = integer_type_node;
4232 /* Make sure TYPE_POINTER_TO (elt_type) is filled in. */
4233 build_pointer_type (elt_type);
4235 /* Allocate the array after the pointer type,
4236 in case we free it in type_hash_canon. */
4237 t = make_node (ARRAY_TYPE);
4238 TREE_TYPE (t) = elt_type;
4239 TYPE_DOMAIN (t) = index_type;
4241 if (index_type == 0)
4246 hashcode = TYPE_HASH (elt_type) + TYPE_HASH (index_type);
4247 t = type_hash_canon (hashcode, t);
4249 if (TYPE_SIZE (t) == 0)
4254 /* Return the TYPE of the elements comprising
4255 the innermost dimension of ARRAY. */
4258 get_inner_array_type (array)
4261 tree type = TREE_TYPE (array);
4263 while (TREE_CODE (type) == ARRAY_TYPE)
4264 type = TREE_TYPE (type);
4269 /* Construct, lay out and return
4270 the type of functions returning type VALUE_TYPE
4271 given arguments of types ARG_TYPES.
4272 ARG_TYPES is a chain of TREE_LIST nodes whose TREE_VALUEs
4273 are data type nodes for the arguments of the function.
4274 If such a type has already been constructed, reuse it. */
4277 build_function_type (value_type, arg_types)
4278 tree value_type, arg_types;
4283 if (TREE_CODE (value_type) == FUNCTION_TYPE)
4285 error ("function return type cannot be function");
4286 value_type = integer_type_node;
4289 /* Make a node of the sort we want. */
4290 t = make_node (FUNCTION_TYPE);
4291 TREE_TYPE (t) = value_type;
4292 TYPE_ARG_TYPES (t) = arg_types;
4294 /* If we already have such a type, use the old one and free this one. */
4295 hashcode = TYPE_HASH (value_type) + type_hash_list (arg_types);
4296 t = type_hash_canon (hashcode, t);
4298 if (TYPE_SIZE (t) == 0)
4303 /* Build the node for the type of references-to-TO_TYPE. */
4306 build_reference_type (to_type)
4309 register tree t = TYPE_REFERENCE_TO (to_type);
4311 /* First, if we already have a type for pointers to TO_TYPE, use it. */
4316 /* We need a new one. Put this in the same obstack as TO_TYPE. */
4317 push_obstacks (TYPE_OBSTACK (to_type), TYPE_OBSTACK (to_type));
4318 t = make_node (REFERENCE_TYPE);
4321 TREE_TYPE (t) = to_type;
4323 /* Record this type as the pointer to TO_TYPE. */
4324 TYPE_REFERENCE_TO (to_type) = t;
4331 /* Construct, lay out and return the type of methods belonging to class
4332 BASETYPE and whose arguments and values are described by TYPE.
4333 If that type exists already, reuse it.
4334 TYPE must be a FUNCTION_TYPE node. */
4337 build_method_type (basetype, type)
4338 tree basetype, type;
4343 /* Make a node of the sort we want. */
4344 t = make_node (METHOD_TYPE);
4346 if (TREE_CODE (type) != FUNCTION_TYPE)
4349 TYPE_METHOD_BASETYPE (t) = TYPE_MAIN_VARIANT (basetype);
4350 TREE_TYPE (t) = TREE_TYPE (type);
4352 /* The actual arglist for this function includes a "hidden" argument
4353 which is "this". Put it into the list of argument types. */
4356 = tree_cons (NULL_TREE,
4357 build_pointer_type (basetype), TYPE_ARG_TYPES (type));
4359 /* If we already have such a type, use the old one and free this one. */
4360 hashcode = TYPE_HASH (basetype) + TYPE_HASH (type);
4361 t = type_hash_canon (hashcode, t);
4363 if (TYPE_SIZE (t) == 0)
4369 /* Construct, lay out and return the type of offsets to a value
4370 of type TYPE, within an object of type BASETYPE.
4371 If a suitable offset type exists already, reuse it. */
4374 build_offset_type (basetype, type)
4375 tree basetype, type;
4380 /* Make a node of the sort we want. */
4381 t = make_node (OFFSET_TYPE);
4383 TYPE_OFFSET_BASETYPE (t) = TYPE_MAIN_VARIANT (basetype);
4384 TREE_TYPE (t) = type;
4386 /* If we already have such a type, use the old one and free this one. */
4387 hashcode = TYPE_HASH (basetype) + TYPE_HASH (type);
4388 t = type_hash_canon (hashcode, t);
4390 if (TYPE_SIZE (t) == 0)
4396 /* Create a complex type whose components are COMPONENT_TYPE. */
4399 build_complex_type (component_type)
4400 tree component_type;
4405 /* Make a node of the sort we want. */
4406 t = make_node (COMPLEX_TYPE);
4408 TREE_TYPE (t) = TYPE_MAIN_VARIANT (component_type);
4409 TYPE_VOLATILE (t) = TYPE_VOLATILE (component_type);
4410 TYPE_READONLY (t) = TYPE_READONLY (component_type);
4412 /* If we already have such a type, use the old one and free this one. */
4413 hashcode = TYPE_HASH (component_type);
4414 t = type_hash_canon (hashcode, t);
4416 if (TYPE_SIZE (t) == 0)
4422 /* Return OP, stripped of any conversions to wider types as much as is safe.
4423 Converting the value back to OP's type makes a value equivalent to OP.
4425 If FOR_TYPE is nonzero, we return a value which, if converted to
4426 type FOR_TYPE, would be equivalent to converting OP to type FOR_TYPE.
4428 If FOR_TYPE is nonzero, unaligned bit-field references may be changed to the
4429 narrowest type that can hold the value, even if they don't exactly fit.
4430 Otherwise, bit-field references are changed to a narrower type
4431 only if they can be fetched directly from memory in that type.
4433 OP must have integer, real or enumeral type. Pointers are not allowed!
4435 There are some cases where the obvious value we could return
4436 would regenerate to OP if converted to OP's type,
4437 but would not extend like OP to wider types.
4438 If FOR_TYPE indicates such extension is contemplated, we eschew such values.
4439 For example, if OP is (unsigned short)(signed char)-1,
4440 we avoid returning (signed char)-1 if FOR_TYPE is int,
4441 even though extending that to an unsigned short would regenerate OP,
4442 since the result of extending (signed char)-1 to (int)
4443 is different from (int) OP. */
4446 get_unwidened (op, for_type)
4450 /* Set UNS initially if converting OP to FOR_TYPE is a zero-extension. */
4451 register tree type = TREE_TYPE (op);
4452 register unsigned final_prec
4453 = TYPE_PRECISION (for_type != 0 ? for_type : type);
4455 = (for_type != 0 && for_type != type
4456 && final_prec > TYPE_PRECISION (type)
4457 && TREE_UNSIGNED (type));
4458 register tree win = op;
4460 while (TREE_CODE (op) == NOP_EXPR)
4462 register int bitschange
4463 = TYPE_PRECISION (TREE_TYPE (op))
4464 - TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (op, 0)));
4466 /* Truncations are many-one so cannot be removed.
4467 Unless we are later going to truncate down even farther. */
4469 && final_prec > TYPE_PRECISION (TREE_TYPE (op)))
4472 /* See what's inside this conversion. If we decide to strip it,
4474 op = TREE_OPERAND (op, 0);
4476 /* If we have not stripped any zero-extensions (uns is 0),
4477 we can strip any kind of extension.
4478 If we have previously stripped a zero-extension,
4479 only zero-extensions can safely be stripped.
4480 Any extension can be stripped if the bits it would produce
4481 are all going to be discarded later by truncating to FOR_TYPE. */
4485 if (! uns || final_prec <= TYPE_PRECISION (TREE_TYPE (op)))
4487 /* TREE_UNSIGNED says whether this is a zero-extension.
4488 Let's avoid computing it if it does not affect WIN
4489 and if UNS will not be needed again. */
4490 if ((uns || TREE_CODE (op) == NOP_EXPR)
4491 && TREE_UNSIGNED (TREE_TYPE (op)))
4499 if (TREE_CODE (op) == COMPONENT_REF
4500 /* Since type_for_size always gives an integer type. */
4501 && TREE_CODE (type) != REAL_TYPE
4502 /* Don't crash if field not laid out yet. */
4503 && DECL_SIZE (TREE_OPERAND (op, 1)) != 0)
4505 unsigned innerprec = TREE_INT_CST_LOW (DECL_SIZE (TREE_OPERAND (op, 1)));
4506 type = type_for_size (innerprec, TREE_UNSIGNED (TREE_OPERAND (op, 1)));
4508 /* We can get this structure field in the narrowest type it fits in.
4509 If FOR_TYPE is 0, do this only for a field that matches the
4510 narrower type exactly and is aligned for it
4511 The resulting extension to its nominal type (a fullword type)
4512 must fit the same conditions as for other extensions. */
4514 if (innerprec < TYPE_PRECISION (TREE_TYPE (op))
4515 && (for_type || ! DECL_BIT_FIELD (TREE_OPERAND (op, 1)))
4516 && (! uns || final_prec <= innerprec
4517 || TREE_UNSIGNED (TREE_OPERAND (op, 1)))
4520 win = build (COMPONENT_REF, type, TREE_OPERAND (op, 0),
4521 TREE_OPERAND (op, 1));
4522 TREE_SIDE_EFFECTS (win) = TREE_SIDE_EFFECTS (op);
4523 TREE_THIS_VOLATILE (win) = TREE_THIS_VOLATILE (op);
4524 TREE_RAISES (win) = TREE_RAISES (op);
4530 /* Return OP or a simpler expression for a narrower value
4531 which can be sign-extended or zero-extended to give back OP.
4532 Store in *UNSIGNEDP_PTR either 1 if the value should be zero-extended
4533 or 0 if the value should be sign-extended. */
4536 get_narrower (op, unsignedp_ptr)
4540 register int uns = 0;
4542 register tree win = op;
4544 while (TREE_CODE (op) == NOP_EXPR)
4546 register int bitschange
4547 = TYPE_PRECISION (TREE_TYPE (op))
4548 - TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (op, 0)));
4550 /* Truncations are many-one so cannot be removed. */
4554 /* See what's inside this conversion. If we decide to strip it,
4556 op = TREE_OPERAND (op, 0);
4560 /* An extension: the outermost one can be stripped,
4561 but remember whether it is zero or sign extension. */
4563 uns = TREE_UNSIGNED (TREE_TYPE (op));
4564 /* Otherwise, if a sign extension has been stripped,
4565 only sign extensions can now be stripped;
4566 if a zero extension has been stripped, only zero-extensions. */
4567 else if (uns != TREE_UNSIGNED (TREE_TYPE (op)))
4571 else /* bitschange == 0 */
4573 /* A change in nominal type can always be stripped, but we must
4574 preserve the unsignedness. */
4576 uns = TREE_UNSIGNED (TREE_TYPE (op));
4583 if (TREE_CODE (op) == COMPONENT_REF
4584 /* Since type_for_size always gives an integer type. */
4585 && TREE_CODE (TREE_TYPE (op)) != REAL_TYPE)
4587 unsigned innerprec = TREE_INT_CST_LOW (DECL_SIZE (TREE_OPERAND (op, 1)));
4588 tree type = type_for_size (innerprec, TREE_UNSIGNED (op));
4590 /* We can get this structure field in a narrower type that fits it,
4591 but the resulting extension to its nominal type (a fullword type)
4592 must satisfy the same conditions as for other extensions.
4594 Do this only for fields that are aligned (not bit-fields),
4595 because when bit-field insns will be used there is no
4596 advantage in doing this. */
4598 if (innerprec < TYPE_PRECISION (TREE_TYPE (op))
4599 && ! DECL_BIT_FIELD (TREE_OPERAND (op, 1))
4600 && (first || uns == TREE_UNSIGNED (TREE_OPERAND (op, 1)))
4604 uns = TREE_UNSIGNED (TREE_OPERAND (op, 1));
4605 win = build (COMPONENT_REF, type, TREE_OPERAND (op, 0),
4606 TREE_OPERAND (op, 1));
4607 TREE_SIDE_EFFECTS (win) = TREE_SIDE_EFFECTS (op);
4608 TREE_THIS_VOLATILE (win) = TREE_THIS_VOLATILE (op);
4609 TREE_RAISES (win) = TREE_RAISES (op);
4612 *unsignedp_ptr = uns;
4616 /* Nonzero if integer constant C has a value that is permissible
4617 for type TYPE (an INTEGER_TYPE). */
4620 int_fits_type_p (c, type)
4623 if (TREE_UNSIGNED (type))
4624 return (! (TREE_CODE (TYPE_MAX_VALUE (type)) == INTEGER_CST
4625 && INT_CST_LT_UNSIGNED (TYPE_MAX_VALUE (type), c))
4626 && ! (TREE_CODE (TYPE_MIN_VALUE (type)) == INTEGER_CST
4627 && INT_CST_LT_UNSIGNED (c, TYPE_MIN_VALUE (type)))
4628 /* Negative ints never fit unsigned types. */
4629 && ! (TREE_INT_CST_HIGH (c) < 0
4630 && ! TREE_UNSIGNED (TREE_TYPE (c))));
4632 return (! (TREE_CODE (TYPE_MAX_VALUE (type)) == INTEGER_CST
4633 && INT_CST_LT (TYPE_MAX_VALUE (type), c))
4634 && ! (TREE_CODE (TYPE_MIN_VALUE (type)) == INTEGER_CST
4635 && INT_CST_LT (c, TYPE_MIN_VALUE (type)))
4636 /* Unsigned ints with top bit set never fit signed types. */
4637 && ! (TREE_INT_CST_HIGH (c) < 0
4638 && TREE_UNSIGNED (TREE_TYPE (c))));
4641 /* Return the innermost context enclosing DECL that is
4642 a FUNCTION_DECL, or zero if none. */
4645 decl_function_context (decl)
4650 if (TREE_CODE (decl) == ERROR_MARK)
4653 if (TREE_CODE (decl) == SAVE_EXPR)
4654 context = SAVE_EXPR_CONTEXT (decl);
4656 context = DECL_CONTEXT (decl);
4658 while (context && TREE_CODE (context) != FUNCTION_DECL)
4660 if (TREE_CODE_CLASS (TREE_CODE (context)) == 't')
4661 context = TYPE_CONTEXT (context);
4662 else if (TREE_CODE_CLASS (TREE_CODE (context)) == 'd')
4663 context = DECL_CONTEXT (context);
4664 else if (TREE_CODE (context) == BLOCK)
4665 context = BLOCK_SUPERCONTEXT (context);
4667 /* Unhandled CONTEXT !? */
4674 /* Return the innermost context enclosing DECL that is
4675 a RECORD_TYPE, UNION_TYPE or QUAL_UNION_TYPE, or zero if none.
4676 TYPE_DECLs and FUNCTION_DECLs are transparent to this function. */
4679 decl_type_context (decl)
4682 tree context = DECL_CONTEXT (decl);
4686 if (TREE_CODE (context) == RECORD_TYPE
4687 || TREE_CODE (context) == UNION_TYPE
4688 || TREE_CODE (context) == QUAL_UNION_TYPE)
4690 if (TREE_CODE (context) == TYPE_DECL
4691 || TREE_CODE (context) == FUNCTION_DECL)
4692 context = DECL_CONTEXT (context);
4693 else if (TREE_CODE (context) == BLOCK)
4694 context = BLOCK_SUPERCONTEXT (context);
4696 /* Unhandled CONTEXT!? */
4702 /* Print debugging information about the size of the
4703 toplev_inline_obstacks. */
4706 print_inline_obstack_statistics ()
4708 struct simple_obstack_stack *current = toplev_inline_obstacks;
4713 for (; current; current = current->next, ++n_obstacks)
4715 struct obstack *o = current->obstack;
4716 struct _obstack_chunk *chunk = o->chunk;
4718 n_alloc += o->next_free - chunk->contents;
4719 chunk = chunk->prev;
4721 for (; chunk; chunk = chunk->prev, ++n_chunks)
4722 n_alloc += chunk->limit - &chunk->contents[0];
4724 fprintf (stderr, "inline obstacks: %d obstacks, %d bytes, %d chunks\n",
4725 n_obstacks, n_alloc, n_chunks);
4728 /* Print debugging information about the obstack O, named STR. */
4731 print_obstack_statistics (str, o)
4735 struct _obstack_chunk *chunk = o->chunk;
4739 n_alloc += o->next_free - chunk->contents;
4740 chunk = chunk->prev;
4744 n_alloc += chunk->limit - &chunk->contents[0];
4745 chunk = chunk->prev;
4747 fprintf (stderr, "obstack %s: %u bytes, %d chunks\n",
4748 str, n_alloc, n_chunks);
4751 /* Print debugging information about tree nodes generated during the compile,
4752 and any language-specific information. */
4755 dump_tree_statistics ()
4757 #ifdef GATHER_STATISTICS
4759 int total_nodes, total_bytes;
4762 fprintf (stderr, "\n??? tree nodes created\n\n");
4763 #ifdef GATHER_STATISTICS
4764 fprintf (stderr, "Kind Nodes Bytes\n");
4765 fprintf (stderr, "-------------------------------------\n");
4766 total_nodes = total_bytes = 0;
4767 for (i = 0; i < (int) all_kinds; i++)
4769 fprintf (stderr, "%-20s %6d %9d\n", tree_node_kind_names[i],
4770 tree_node_counts[i], tree_node_sizes[i]);
4771 total_nodes += tree_node_counts[i];
4772 total_bytes += tree_node_sizes[i];
4774 fprintf (stderr, "%-20s %9d\n", "identifier names", id_string_size);
4775 fprintf (stderr, "-------------------------------------\n");
4776 fprintf (stderr, "%-20s %6d %9d\n", "Total", total_nodes, total_bytes);
4777 fprintf (stderr, "-------------------------------------\n");
4779 fprintf (stderr, "(No per-node statistics)\n");
4781 print_obstack_statistics ("permanent_obstack", &permanent_obstack);
4782 print_obstack_statistics ("maybepermanent_obstack", &maybepermanent_obstack);
4783 print_obstack_statistics ("temporary_obstack", &temporary_obstack);
4784 print_obstack_statistics ("momentary_obstack", &momentary_obstack);
4785 print_obstack_statistics ("temp_decl_obstack", &temp_decl_obstack);
4786 print_inline_obstack_statistics ();
4787 print_lang_statistics ();
4790 #define FILE_FUNCTION_PREFIX_LEN 9
4792 #ifndef NO_DOLLAR_IN_LABEL
4793 #define FILE_FUNCTION_FORMAT "_GLOBAL_$D$%s"
4794 #else /* NO_DOLLAR_IN_LABEL */
4795 #ifndef NO_DOT_IN_LABEL
4796 #define FILE_FUNCTION_FORMAT "_GLOBAL_.D.%s"
4797 #else /* NO_DOT_IN_LABEL */
4798 #define FILE_FUNCTION_FORMAT "_GLOBAL__D_%s"
4799 #endif /* NO_DOT_IN_LABEL */
4800 #endif /* NO_DOLLAR_IN_LABEL */
4802 extern char * first_global_object_name;
4803 extern char * weak_global_object_name;
4805 /* If KIND=='I', return a suitable global initializer (constructor) name.
4806 If KIND=='D', return a suitable global clean-up (destructor) name. */
4809 get_file_function_name (kind)
4815 if (first_global_object_name)
4816 p = first_global_object_name;
4817 else if (weak_global_object_name)
4818 p = weak_global_object_name;
4819 else if (main_input_filename)
4820 p = main_input_filename;
4824 buf = (char *) alloca (sizeof (FILE_FUNCTION_FORMAT) + strlen (p));
4826 /* Set up the name of the file-level functions we may need. */
4827 /* Use a global object (which is already required to be unique over
4828 the program) rather than the file name (which imposes extra
4829 constraints). -- Raeburn@MIT.EDU, 10 Jan 1990. */
4830 sprintf (buf, FILE_FUNCTION_FORMAT, p);
4832 /* Don't need to pull weird characters out of global names. */
4833 if (p != first_global_object_name)
4835 for (p = buf+11; *p; p++)
4836 if (! ((*p >= '0' && *p <= '9')
4837 #if 0 /* we always want labels, which are valid C++ identifiers (+ `$') */
4838 #ifndef ASM_IDENTIFY_GCC /* this is required if `.' is invalid -- k. raeburn */
4842 #ifndef NO_DOLLAR_IN_LABEL /* this for `$'; unlikely, but... -- kr */
4845 #ifndef NO_DOT_IN_LABEL /* this for `.'; unlikely, but... */
4848 || (*p >= 'A' && *p <= 'Z')
4849 || (*p >= 'a' && *p <= 'z')))
4853 buf[FILE_FUNCTION_PREFIX_LEN] = kind;
4855 return get_identifier (buf);
4858 /* Expand (the constant part of) a SET_TYPE CONSTRUCTOR node.
4859 The result is placed in BUFFER (which has length BIT_SIZE),
4860 with one bit in each char ('\000' or '\001').
4862 If the constructor is constant, NULL_TREE is returned.
4863 Otherwise, a TREE_LIST of the non-constant elements is emitted. */
4866 get_set_constructor_bits (init, buffer, bit_size)
4873 HOST_WIDE_INT domain_min
4874 = TREE_INT_CST_LOW (TYPE_MIN_VALUE (TYPE_DOMAIN (TREE_TYPE (init))));
4875 tree non_const_bits = NULL_TREE;
4876 for (i = 0; i < bit_size; i++)
4879 for (vals = TREE_OPERAND (init, 1);
4880 vals != NULL_TREE; vals = TREE_CHAIN (vals))
4882 if (TREE_CODE (TREE_VALUE (vals)) != INTEGER_CST
4883 || (TREE_PURPOSE (vals) != NULL_TREE
4884 && TREE_CODE (TREE_PURPOSE (vals)) != INTEGER_CST))
4886 = tree_cons (TREE_PURPOSE (vals), TREE_VALUE (vals), non_const_bits);
4887 else if (TREE_PURPOSE (vals) != NULL_TREE)
4889 /* Set a range of bits to ones. */
4890 HOST_WIDE_INT lo_index
4891 = TREE_INT_CST_LOW (TREE_PURPOSE (vals)) - domain_min;
4892 HOST_WIDE_INT hi_index
4893 = TREE_INT_CST_LOW (TREE_VALUE (vals)) - domain_min;
4894 if (lo_index < 0 || lo_index >= bit_size
4895 || hi_index < 0 || hi_index >= bit_size)
4897 for ( ; lo_index <= hi_index; lo_index++)
4898 buffer[lo_index] = 1;
4902 /* Set a single bit to one. */
4904 = TREE_INT_CST_LOW (TREE_VALUE (vals)) - domain_min;
4905 if (index < 0 || index >= bit_size)
4907 error ("invalid initializer for bit string");
4913 return non_const_bits;
4916 /* Expand (the constant part of) a SET_TYPE CONSTRUCTOR node.
4917 The result is placed in BUFFER (which is an array of bytes).
4918 If the constructor is constant, NULL_TREE is returned.
4919 Otherwise, a TREE_LIST of the non-constant elements is emitted. */
4922 get_set_constructor_bytes (init, buffer, wd_size)
4924 unsigned char *buffer;
4928 int set_word_size = BITS_PER_UNIT;
4929 int bit_size = wd_size * set_word_size;
4931 unsigned char *bytep = buffer;
4932 char *bit_buffer = (char *) alloca(bit_size);
4933 tree non_const_bits = get_set_constructor_bits (init, bit_buffer, bit_size);
4935 for (i = 0; i < wd_size; i++)
4938 for (i = 0; i < bit_size; i++)
4942 if (BYTES_BIG_ENDIAN)
4943 *bytep |= (1 << (set_word_size - 1 - bit_pos));
4945 *bytep |= 1 << bit_pos;
4948 if (bit_pos >= set_word_size)
4949 bit_pos = 0, bytep++;
4951 return non_const_bits;
4954 #ifdef ENABLE_CHECKING
4956 /* Complain if the tree code does not match the expected one.
4957 NODE is the tree node in question, CODE is the expected tree code,
4958 and FILE and LINE are the filename and line number, respectively,
4959 of the line on which the check was done. If NONFATAL is nonzero,
4960 don't abort if the reference is invalid; instead, return 0.
4961 If the reference is valid, return NODE. */
4964 tree_check (node, code, file, line, nofatal)
4966 enum tree_code code;
4971 if (TREE_CODE (node) == code)
4976 fatal ("%s:%d: Expect %s, have %s\n", file, line,
4977 tree_code_name[code], tree_code_name[TREE_CODE (node)]);
4980 /* Similar to above, except that we check for a class of tree
4981 code, given in CL. */
4984 tree_class_check (node, cl, file, line, nofatal)
4991 if (TREE_CODE_CLASS (TREE_CODE (node)) == cl)
4996 fatal ("%s:%d: Expect '%c', have '%s'\n", file, line,
4997 cl, tree_code_name[TREE_CODE (node)]);
5000 /* Likewise, but complain if the tree node is not an expression. */
5003 expr_check (node, ignored, file, line, nofatal)
5010 switch (TREE_CODE_CLASS (TREE_CODE (node)))
5024 fatal ("%s:%d: Expect expression, have '%s'\n", file, line,
5025 tree_code_name[TREE_CODE (node)]);
5032 /* Return the alias set for T, which may be either a type or an
5035 int get_alias_set (t)
5038 if (!flag_strict_aliasing || !lang_get_alias_set)
5039 /* If we're not doing any lanaguage-specific alias analysis, just
5040 assume everything aliases everything else. */
5043 return (*lang_get_alias_set) (t);