1 /* Language-independent node constructors for parse phase of GNU compiler.
2 Copyright (C) 1987, 88, 92-98, 1999 Free Software Foundation, Inc.
4 This file is part of GNU CC.
6 GNU CC is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 2, or (at your option)
11 GNU CC is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with GNU CC; see the file COPYING. If not, write to
18 the Free Software Foundation, 59 Temple Place - Suite 330,
19 Boston, MA 02111-1307, USA. */
22 /* This file contains the low level primitives for operating on tree nodes,
23 including allocation, list operations, interning of identifiers,
24 construction of data type nodes and statement nodes,
25 and construction of type conversion nodes. It also contains
26 tables index by tree code that describe how to take apart
29 It is intended to be language-independent, but occasionally
30 calls language-dependent routines defined (for C) in typecheck.c.
32 The low-level allocation routines oballoc and permalloc
33 are used also for allocating many other kinds of objects
34 by all passes of the compiler. */
45 #define obstack_chunk_alloc xmalloc
46 #define obstack_chunk_free free
47 /* obstack.[ch] explicitly declined to prototype this. */
48 extern int _obstack_allocated_p PROTO ((struct obstack *h, GENERIC_PTR obj));
50 /* Tree nodes of permanent duration are allocated in this obstack.
51 They are the identifier nodes, and everything outside of
52 the bodies and parameters of function definitions. */
54 struct obstack permanent_obstack;
56 /* The initial RTL, and all ..._TYPE nodes, in a function
57 are allocated in this obstack. Usually they are freed at the
58 end of the function, but if the function is inline they are saved.
59 For top-level functions, this is maybepermanent_obstack.
60 Separate obstacks are made for nested functions. */
62 struct obstack *function_maybepermanent_obstack;
64 /* This is the function_maybepermanent_obstack for top-level functions. */
66 struct obstack maybepermanent_obstack;
68 /* The contents of the current function definition are allocated
69 in this obstack, and all are freed at the end of the function.
70 For top-level functions, this is temporary_obstack.
71 Separate obstacks are made for nested functions. */
73 struct obstack *function_obstack;
75 /* This is used for reading initializers of global variables. */
77 struct obstack temporary_obstack;
79 /* The tree nodes of an expression are allocated
80 in this obstack, and all are freed at the end of the expression. */
82 struct obstack momentary_obstack;
84 /* The tree nodes of a declarator are allocated
85 in this obstack, and all are freed when the declarator
88 static struct obstack temp_decl_obstack;
90 /* This points at either permanent_obstack
91 or the current function_maybepermanent_obstack. */
93 struct obstack *saveable_obstack;
95 /* This is same as saveable_obstack during parse and expansion phase;
96 it points to the current function's obstack during optimization.
97 This is the obstack to be used for creating rtl objects. */
99 struct obstack *rtl_obstack;
101 /* This points at either permanent_obstack or the current function_obstack. */
103 struct obstack *current_obstack;
105 /* This points at either permanent_obstack or the current function_obstack
106 or momentary_obstack. */
108 struct obstack *expression_obstack;
110 /* Stack of obstack selections for push_obstacks and pop_obstacks. */
114 struct obstack_stack *next;
115 struct obstack *current;
116 struct obstack *saveable;
117 struct obstack *expression;
121 struct obstack_stack *obstack_stack;
123 /* Obstack for allocating struct obstack_stack entries. */
125 static struct obstack obstack_stack_obstack;
127 /* Addresses of first objects in some obstacks.
128 This is for freeing their entire contents. */
129 char *maybepermanent_firstobj;
130 char *temporary_firstobj;
131 char *momentary_firstobj;
132 char *temp_decl_firstobj;
134 /* This is used to preserve objects (mainly array initializers) that need to
135 live until the end of the current function, but no further. */
136 char *momentary_function_firstobj;
138 /* Nonzero means all ..._TYPE nodes should be allocated permanently. */
140 int all_types_permanent;
142 /* Stack of places to restore the momentary obstack back to. */
144 struct momentary_level
146 /* Pointer back to previous such level. */
147 struct momentary_level *prev;
148 /* First object allocated within this level. */
150 /* Value of expression_obstack saved at entry to this level. */
151 struct obstack *obstack;
154 struct momentary_level *momentary_stack;
156 /* Table indexed by tree code giving a string containing a character
157 classifying the tree code. Possibilities are
158 t, d, s, c, r, <, 1, 2 and e. See tree.def for details. */
160 #define DEFTREECODE(SYM, NAME, TYPE, LENGTH) TYPE,
162 char tree_code_type[MAX_TREE_CODES] = {
167 /* Table indexed by tree code giving number of expression
168 operands beyond the fixed part of the node structure.
169 Not used for types or decls. */
171 #define DEFTREECODE(SYM, NAME, TYPE, LENGTH) LENGTH,
173 int tree_code_length[MAX_TREE_CODES] = {
178 /* Names of tree components.
179 Used for printing out the tree and error messages. */
180 #define DEFTREECODE(SYM, NAME, TYPE, LEN) NAME,
182 const char *tree_code_name[MAX_TREE_CODES] = {
187 /* Statistics-gathering stuff. */
208 int tree_node_counts[(int)all_kinds];
209 int tree_node_sizes[(int)all_kinds];
210 int id_string_size = 0;
212 const char *tree_node_kind_names[] = {
230 /* Hash table for uniquizing IDENTIFIER_NODEs by name. */
232 #define MAX_HASH_TABLE 1009
233 static tree hash_table[MAX_HASH_TABLE]; /* id hash buckets */
235 /* 0 while creating built-in identifiers. */
236 static int do_identifier_warnings;
238 /* Unique id for next decl created. */
239 static int next_decl_uid;
240 /* Unique id for next type created. */
241 static int next_type_uid = 1;
243 /* The language-specific function for alias analysis. If NULL, the
244 language does not do any special alias analysis. */
245 int (*lang_get_alias_set) PROTO((tree));
247 /* Here is how primitive or already-canonicalized types' hash
249 #define TYPE_HASH(TYPE) ((unsigned long) (TYPE) & 0777777)
251 /* Each hash table slot is a bucket containing a chain
252 of these structures. */
256 struct type_hash *next; /* Next structure in the bucket. */
257 int hashcode; /* Hash code of this type. */
258 tree type; /* The type recorded here. */
261 /* Now here is the hash table. When recording a type, it is added
262 to the slot whose index is the hash code mod the table size.
263 Note that the hash table is used for several kinds of types
264 (function types, array types and array index range types, for now).
265 While all these live in the same table, they are completely independent,
266 and the hash code is computed differently for each of these. */
268 #define TYPE_HASH_SIZE 59
269 struct type_hash *type_hash_table[TYPE_HASH_SIZE];
271 static void set_type_quals PROTO((tree, int));
272 static void append_random_chars PROTO((char *));
273 static void build_real_from_int_cst_1 PROTO((PTR));
274 static void mark_type_hash PROTO ((void *));
276 void gcc_obstack_init ();
278 /* If non-null, a language specific helper for unsave_expr_now. */
280 void (*lang_unsave_expr_now) PROTO((tree));
282 /* Init the principal obstacks. */
287 gcc_obstack_init (&obstack_stack_obstack);
288 gcc_obstack_init (&permanent_obstack);
290 gcc_obstack_init (&temporary_obstack);
291 temporary_firstobj = (char *) obstack_alloc (&temporary_obstack, 0);
292 gcc_obstack_init (&momentary_obstack);
293 momentary_firstobj = (char *) obstack_alloc (&momentary_obstack, 0);
294 momentary_function_firstobj = momentary_firstobj;
295 gcc_obstack_init (&maybepermanent_obstack);
296 maybepermanent_firstobj
297 = (char *) obstack_alloc (&maybepermanent_obstack, 0);
298 gcc_obstack_init (&temp_decl_obstack);
299 temp_decl_firstobj = (char *) obstack_alloc (&temp_decl_obstack, 0);
301 function_obstack = &temporary_obstack;
302 function_maybepermanent_obstack = &maybepermanent_obstack;
303 current_obstack = &permanent_obstack;
304 expression_obstack = &permanent_obstack;
305 rtl_obstack = saveable_obstack = &permanent_obstack;
307 /* Init the hash table of identifiers. */
308 bzero ((char *) hash_table, sizeof hash_table);
310 ggc_add_tree_root (hash_table, MAX_HASH_TABLE);
311 ggc_add_root (type_hash_table, TYPE_HASH_SIZE,
312 sizeof(struct type_hash *),
317 gcc_obstack_init (obstack)
318 struct obstack *obstack;
320 /* Let particular systems override the size of a chunk. */
321 #ifndef OBSTACK_CHUNK_SIZE
322 #define OBSTACK_CHUNK_SIZE 0
324 /* Let them override the alloc and free routines too. */
325 #ifndef OBSTACK_CHUNK_ALLOC
326 #define OBSTACK_CHUNK_ALLOC xmalloc
328 #ifndef OBSTACK_CHUNK_FREE
329 #define OBSTACK_CHUNK_FREE free
331 _obstack_begin (obstack, OBSTACK_CHUNK_SIZE, 0,
332 (void *(*) ()) OBSTACK_CHUNK_ALLOC,
333 (void (*) ()) OBSTACK_CHUNK_FREE);
336 /* Save all variables describing the current status into the structure
337 *P. This function is called whenever we start compiling one
338 function in the midst of compiling another. For example, when
339 compiling a nested function, or, in C++, a template instantiation
340 that is required by the function we are currently compiling.
342 CONTEXT is the decl_function_context for the function we're about to
343 compile; if it isn't current_function_decl, we have to play some games. */
349 p->all_types_permanent = all_types_permanent;
350 p->momentary_stack = momentary_stack;
351 p->maybepermanent_firstobj = maybepermanent_firstobj;
352 p->temporary_firstobj = temporary_firstobj;
353 p->momentary_firstobj = momentary_firstobj;
354 p->momentary_function_firstobj = momentary_function_firstobj;
355 p->function_obstack = function_obstack;
356 p->function_maybepermanent_obstack = function_maybepermanent_obstack;
357 p->current_obstack = current_obstack;
358 p->expression_obstack = expression_obstack;
359 p->saveable_obstack = saveable_obstack;
360 p->rtl_obstack = rtl_obstack;
362 function_maybepermanent_obstack
363 = (struct obstack *) xmalloc (sizeof (struct obstack));
364 gcc_obstack_init (function_maybepermanent_obstack);
365 maybepermanent_firstobj
366 = (char *) obstack_finish (function_maybepermanent_obstack);
368 function_obstack = (struct obstack *) xmalloc (sizeof (struct obstack));
369 gcc_obstack_init (function_obstack);
371 current_obstack = &permanent_obstack;
372 expression_obstack = &permanent_obstack;
373 rtl_obstack = saveable_obstack = &permanent_obstack;
375 temporary_firstobj = (char *) obstack_alloc (&temporary_obstack, 0);
376 momentary_firstobj = (char *) obstack_finish (&momentary_obstack);
377 momentary_function_firstobj = momentary_firstobj;
380 /* Restore all variables describing the current status from the structure *P.
381 This is used after a nested function. */
384 restore_tree_status (p)
387 all_types_permanent = p->all_types_permanent;
388 momentary_stack = p->momentary_stack;
390 obstack_free (&momentary_obstack, momentary_function_firstobj);
392 /* Free saveable storage used by the function just compiled and not
394 obstack_free (function_maybepermanent_obstack, maybepermanent_firstobj);
396 obstack_free (&temporary_obstack, temporary_firstobj);
397 obstack_free (&momentary_obstack, momentary_function_firstobj);
399 obstack_free (function_obstack, 0);
401 if (obstack_empty_p (function_maybepermanent_obstack))
402 free (function_maybepermanent_obstack);
403 free (function_obstack);
405 temporary_firstobj = p->temporary_firstobj;
406 momentary_firstobj = p->momentary_firstobj;
407 momentary_function_firstobj = p->momentary_function_firstobj;
408 maybepermanent_firstobj = p->maybepermanent_firstobj;
409 function_obstack = p->function_obstack;
410 function_maybepermanent_obstack = p->function_maybepermanent_obstack;
411 current_obstack = p->current_obstack;
412 expression_obstack = p->expression_obstack;
413 saveable_obstack = p->saveable_obstack;
414 rtl_obstack = p->rtl_obstack;
417 /* Start allocating on the temporary (per function) obstack.
418 This is done in start_function before parsing the function body,
419 and before each initialization at top level, and to go back
420 to temporary allocation after doing permanent_allocation. */
423 temporary_allocation ()
425 /* Note that function_obstack at top level points to temporary_obstack.
426 But within a nested function context, it is a separate obstack. */
427 current_obstack = function_obstack;
428 expression_obstack = function_obstack;
429 rtl_obstack = saveable_obstack = function_maybepermanent_obstack;
433 /* Start allocating on the permanent obstack but don't
434 free the temporary data. After calling this, call
435 `permanent_allocation' to fully resume permanent allocation status. */
438 end_temporary_allocation ()
440 current_obstack = &permanent_obstack;
441 expression_obstack = &permanent_obstack;
442 rtl_obstack = saveable_obstack = &permanent_obstack;
445 /* Resume allocating on the temporary obstack, undoing
446 effects of `end_temporary_allocation'. */
449 resume_temporary_allocation ()
451 current_obstack = function_obstack;
452 expression_obstack = function_obstack;
453 rtl_obstack = saveable_obstack = function_maybepermanent_obstack;
456 /* While doing temporary allocation, switch to allocating in such a
457 way as to save all nodes if the function is inlined. Call
458 resume_temporary_allocation to go back to ordinary temporary
462 saveable_allocation ()
464 /* Note that function_obstack at top level points to temporary_obstack.
465 But within a nested function context, it is a separate obstack. */
466 expression_obstack = current_obstack = saveable_obstack;
469 /* Switch to current obstack CURRENT and maybepermanent obstack SAVEABLE,
470 recording the previously current obstacks on a stack.
471 This does not free any storage in any obstack. */
474 push_obstacks (current, saveable)
475 struct obstack *current, *saveable;
477 struct obstack_stack *p
478 = (struct obstack_stack *) obstack_alloc (&obstack_stack_obstack,
479 (sizeof (struct obstack_stack)));
481 p->current = current_obstack;
482 p->saveable = saveable_obstack;
483 p->expression = expression_obstack;
484 p->rtl = rtl_obstack;
485 p->next = obstack_stack;
488 current_obstack = current;
489 expression_obstack = current;
490 rtl_obstack = saveable_obstack = saveable;
493 /* Save the current set of obstacks, but don't change them. */
496 push_obstacks_nochange ()
498 struct obstack_stack *p
499 = (struct obstack_stack *) obstack_alloc (&obstack_stack_obstack,
500 (sizeof (struct obstack_stack)));
502 p->current = current_obstack;
503 p->saveable = saveable_obstack;
504 p->expression = expression_obstack;
505 p->rtl = rtl_obstack;
506 p->next = obstack_stack;
510 /* Pop the obstack selection stack. */
515 struct obstack_stack *p = obstack_stack;
516 obstack_stack = p->next;
518 current_obstack = p->current;
519 saveable_obstack = p->saveable;
520 expression_obstack = p->expression;
521 rtl_obstack = p->rtl;
523 obstack_free (&obstack_stack_obstack, p);
526 /* Nonzero if temporary allocation is currently in effect.
527 Zero if currently doing permanent allocation. */
530 allocation_temporary_p ()
532 return current_obstack != &permanent_obstack;
535 /* Go back to allocating on the permanent obstack
536 and free everything in the temporary obstack.
538 FUNCTION_END is true only if we have just finished compiling a function.
539 In that case, we also free preserved initial values on the momentary
543 permanent_allocation (function_end)
546 /* Free up previous temporary obstack data */
547 obstack_free (&temporary_obstack, temporary_firstobj);
550 obstack_free (&momentary_obstack, momentary_function_firstobj);
551 momentary_firstobj = momentary_function_firstobj;
554 obstack_free (&momentary_obstack, momentary_firstobj);
555 obstack_free (function_maybepermanent_obstack, maybepermanent_firstobj);
556 obstack_free (&temp_decl_obstack, temp_decl_firstobj);
558 current_obstack = &permanent_obstack;
559 expression_obstack = &permanent_obstack;
560 rtl_obstack = saveable_obstack = &permanent_obstack;
563 /* Save permanently everything on the maybepermanent_obstack. */
568 maybepermanent_firstobj
569 = (char *) obstack_alloc (function_maybepermanent_obstack, 0);
573 preserve_initializer ()
575 struct momentary_level *tem;
579 = (char *) obstack_alloc (&temporary_obstack, 0);
580 maybepermanent_firstobj
581 = (char *) obstack_alloc (function_maybepermanent_obstack, 0);
583 old_momentary = momentary_firstobj;
585 = (char *) obstack_alloc (&momentary_obstack, 0);
586 if (momentary_firstobj != old_momentary)
587 for (tem = momentary_stack; tem; tem = tem->prev)
588 tem->base = momentary_firstobj;
591 /* Start allocating new rtl in current_obstack.
592 Use resume_temporary_allocation
593 to go back to allocating rtl in saveable_obstack. */
596 rtl_in_current_obstack ()
598 rtl_obstack = current_obstack;
601 /* Start allocating rtl from saveable_obstack. Intended to be used after
602 a call to push_obstacks_nochange. */
605 rtl_in_saveable_obstack ()
607 rtl_obstack = saveable_obstack;
610 /* Allocate SIZE bytes in the current obstack
611 and return a pointer to them.
612 In practice the current obstack is always the temporary one. */
618 return (char *) obstack_alloc (current_obstack, size);
621 /* Free the object PTR in the current obstack
622 as well as everything allocated since PTR.
623 In practice the current obstack is always the temporary one. */
629 obstack_free (current_obstack, ptr);
632 /* Allocate SIZE bytes in the permanent obstack
633 and return a pointer to them. */
639 return (char *) obstack_alloc (&permanent_obstack, size);
642 /* Allocate NELEM items of SIZE bytes in the permanent obstack
643 and return a pointer to them. The storage is cleared before
644 returning the value. */
647 perm_calloc (nelem, size)
651 char *rval = (char *) obstack_alloc (&permanent_obstack, nelem * size);
652 bzero (rval, nelem * size);
656 /* Allocate SIZE bytes in the saveable obstack
657 and return a pointer to them. */
663 return (char *) obstack_alloc (saveable_obstack, size);
666 /* Allocate SIZE bytes in the expression obstack
667 and return a pointer to them. */
673 return (char *) obstack_alloc (expression_obstack, size);
676 /* Print out which obstack an object is in. */
679 print_obstack_name (object, file, prefix)
684 struct obstack *obstack = NULL;
685 const char *obstack_name = NULL;
688 for (p = outer_function_chain; p; p = p->next)
690 if (_obstack_allocated_p (p->function_obstack, object))
692 obstack = p->function_obstack;
693 obstack_name = "containing function obstack";
695 if (_obstack_allocated_p (p->function_maybepermanent_obstack, object))
697 obstack = p->function_maybepermanent_obstack;
698 obstack_name = "containing function maybepermanent obstack";
702 if (_obstack_allocated_p (&obstack_stack_obstack, object))
704 obstack = &obstack_stack_obstack;
705 obstack_name = "obstack_stack_obstack";
707 else if (_obstack_allocated_p (function_obstack, object))
709 obstack = function_obstack;
710 obstack_name = "function obstack";
712 else if (_obstack_allocated_p (&permanent_obstack, object))
714 obstack = &permanent_obstack;
715 obstack_name = "permanent_obstack";
717 else if (_obstack_allocated_p (&momentary_obstack, object))
719 obstack = &momentary_obstack;
720 obstack_name = "momentary_obstack";
722 else if (_obstack_allocated_p (function_maybepermanent_obstack, object))
724 obstack = function_maybepermanent_obstack;
725 obstack_name = "function maybepermanent obstack";
727 else if (_obstack_allocated_p (&temp_decl_obstack, object))
729 obstack = &temp_decl_obstack;
730 obstack_name = "temp_decl_obstack";
733 /* Check to see if the object is in the free area of the obstack. */
736 if (object >= obstack->next_free
737 && object < obstack->chunk_limit)
738 fprintf (file, "%s in free portion of obstack %s",
739 prefix, obstack_name);
741 fprintf (file, "%s allocated from %s", prefix, obstack_name);
744 fprintf (file, "%s not allocated from any obstack", prefix);
748 debug_obstack (object)
751 print_obstack_name (object, stderr, "object");
752 fprintf (stderr, ".\n");
755 /* Return 1 if OBJ is in the permanent obstack.
756 This is slow, and should be used only for debugging.
757 Use TREE_PERMANENT for other purposes. */
760 object_permanent_p (obj)
763 return _obstack_allocated_p (&permanent_obstack, obj);
766 /* Start a level of momentary allocation.
767 In C, each compound statement has its own level
768 and that level is freed at the end of each statement.
769 All expression nodes are allocated in the momentary allocation level. */
774 struct momentary_level *tem
775 = (struct momentary_level *) obstack_alloc (&momentary_obstack,
776 sizeof (struct momentary_level));
777 tem->prev = momentary_stack;
778 tem->base = (char *) obstack_base (&momentary_obstack);
779 tem->obstack = expression_obstack;
780 momentary_stack = tem;
781 expression_obstack = &momentary_obstack;
784 /* Set things up so the next clear_momentary will only clear memory
785 past our present position in momentary_obstack. */
788 preserve_momentary ()
790 momentary_stack->base = (char *) obstack_base (&momentary_obstack);
793 /* Free all the storage in the current momentary-allocation level.
794 In C, this happens at the end of each statement. */
799 obstack_free (&momentary_obstack, momentary_stack->base);
802 /* Discard a level of momentary allocation.
803 In C, this happens at the end of each compound statement.
804 Restore the status of expression node allocation
805 that was in effect before this level was created. */
810 struct momentary_level *tem = momentary_stack;
811 momentary_stack = tem->prev;
812 expression_obstack = tem->obstack;
813 /* We can't free TEM from the momentary_obstack, because there might
814 be objects above it which have been saved. We can free back to the
815 stack of the level we are popping off though. */
816 obstack_free (&momentary_obstack, tem->base);
819 /* Pop back to the previous level of momentary allocation,
820 but don't free any momentary data just yet. */
823 pop_momentary_nofree ()
825 struct momentary_level *tem = momentary_stack;
826 momentary_stack = tem->prev;
827 expression_obstack = tem->obstack;
830 /* Call when starting to parse a declaration:
831 make expressions in the declaration last the length of the function.
832 Returns an argument that should be passed to resume_momentary later. */
837 register int tem = expression_obstack == &momentary_obstack;
838 expression_obstack = saveable_obstack;
842 /* Call when finished parsing a declaration:
843 restore the treatment of node-allocation that was
844 in effect before the suspension.
845 YES should be the value previously returned by suspend_momentary. */
848 resume_momentary (yes)
852 expression_obstack = &momentary_obstack;
855 /* Init the tables indexed by tree code.
856 Note that languages can add to these tables to define their own codes. */
864 /* Return a newly allocated node of code CODE.
865 Initialize the node's unique id and its TREE_PERMANENT flag.
866 For decl and type nodes, some other fields are initialized.
867 The rest of the node is initialized to zero.
869 Achoo! I got a code in the node. */
876 register int type = TREE_CODE_CLASS (code);
877 register int length = 0;
878 register struct obstack *obstack = current_obstack;
879 #ifdef GATHER_STATISTICS
880 register tree_node_kind kind;
885 case 'd': /* A decl node */
886 #ifdef GATHER_STATISTICS
889 length = sizeof (struct tree_decl);
890 /* All decls in an inline function need to be saved. */
891 if (obstack != &permanent_obstack)
892 obstack = saveable_obstack;
894 /* PARM_DECLs go on the context of the parent. If this is a nested
895 function, then we must allocate the PARM_DECL on the parent's
896 obstack, so that they will live to the end of the parent's
897 closing brace. This is necessary in case we try to inline the
898 function into its parent.
900 PARM_DECLs of top-level functions do not have this problem. However,
901 we allocate them where we put the FUNCTION_DECL for languages such as
902 Ada that need to consult some flags in the PARM_DECLs of the function
905 See comment in restore_tree_status for why we can't put this
906 in function_obstack. */
907 if (code == PARM_DECL && obstack != &permanent_obstack)
910 if (current_function_decl)
911 context = decl_function_context (current_function_decl);
915 = find_function_data (context)->function_maybepermanent_obstack;
919 case 't': /* a type node */
920 #ifdef GATHER_STATISTICS
923 length = sizeof (struct tree_type);
924 /* All data types are put where we can preserve them if nec. */
925 if (obstack != &permanent_obstack)
926 obstack = all_types_permanent ? &permanent_obstack : saveable_obstack;
929 case 'b': /* a lexical block */
930 #ifdef GATHER_STATISTICS
933 length = sizeof (struct tree_block);
934 /* All BLOCK nodes are put where we can preserve them if nec. */
935 if (obstack != &permanent_obstack)
936 obstack = saveable_obstack;
939 case 's': /* an expression with side effects */
940 #ifdef GATHER_STATISTICS
944 case 'r': /* a reference */
945 #ifdef GATHER_STATISTICS
949 case 'e': /* an expression */
950 case '<': /* a comparison expression */
951 case '1': /* a unary arithmetic expression */
952 case '2': /* a binary arithmetic expression */
953 #ifdef GATHER_STATISTICS
957 obstack = expression_obstack;
958 /* All BIND_EXPR nodes are put where we can preserve them if nec. */
959 if (code == BIND_EXPR && obstack != &permanent_obstack)
960 obstack = saveable_obstack;
961 length = sizeof (struct tree_exp)
962 + (tree_code_length[(int) code] - 1) * sizeof (char *);
965 case 'c': /* a constant */
966 #ifdef GATHER_STATISTICS
969 obstack = expression_obstack;
971 /* We can't use tree_code_length for INTEGER_CST, since the number of
972 words is machine-dependent due to varying length of HOST_WIDE_INT,
973 which might be wider than a pointer (e.g., long long). Similarly
974 for REAL_CST, since the number of words is machine-dependent due
975 to varying size and alignment of `double'. */
977 if (code == INTEGER_CST)
978 length = sizeof (struct tree_int_cst);
979 else if (code == REAL_CST)
980 length = sizeof (struct tree_real_cst);
982 length = sizeof (struct tree_common)
983 + tree_code_length[(int) code] * sizeof (char *);
986 case 'x': /* something random, like an identifier. */
987 #ifdef GATHER_STATISTICS
988 if (code == IDENTIFIER_NODE)
990 else if (code == OP_IDENTIFIER)
992 else if (code == TREE_VEC)
997 length = sizeof (struct tree_common)
998 + tree_code_length[(int) code] * sizeof (char *);
999 /* Identifier nodes are always permanent since they are
1000 unique in a compiler run. */
1001 if (code == IDENTIFIER_NODE) obstack = &permanent_obstack;
1008 t = (tree) obstack_alloc (obstack, length);
1009 bzero ((PTR) t, length);
1011 #ifdef GATHER_STATISTICS
1012 tree_node_counts[(int)kind]++;
1013 tree_node_sizes[(int)kind] += length;
1016 TREE_SET_CODE (t, code);
1017 if (obstack == &permanent_obstack)
1018 TREE_PERMANENT (t) = 1;
1023 TREE_SIDE_EFFECTS (t) = 1;
1024 TREE_TYPE (t) = void_type_node;
1028 if (code != FUNCTION_DECL)
1030 DECL_IN_SYSTEM_HEADER (t)
1031 = in_system_header && (obstack == &permanent_obstack);
1032 DECL_SOURCE_LINE (t) = lineno;
1033 DECL_SOURCE_FILE (t) = (input_filename) ? input_filename : "<built-in>";
1034 DECL_UID (t) = next_decl_uid++;
1035 /* Note that we have not yet computed the alias set for this
1037 DECL_POINTER_ALIAS_SET (t) = -1;
1041 TYPE_UID (t) = next_type_uid++;
1043 TYPE_MAIN_VARIANT (t) = t;
1044 TYPE_OBSTACK (t) = obstack;
1045 TYPE_ATTRIBUTES (t) = NULL_TREE;
1046 #ifdef SET_DEFAULT_TYPE_ATTRIBUTES
1047 SET_DEFAULT_TYPE_ATTRIBUTES (t);
1049 /* Note that we have not yet computed the alias set for this
1051 TYPE_ALIAS_SET (t) = -1;
1055 TREE_CONSTANT (t) = 1;
1062 /* Return a new node with the same contents as NODE except that its
1063 TREE_CHAIN is zero and it has a fresh uid. Unlike make_node, this
1064 function always performs the allocation on the CURRENT_OBSTACK;
1065 it's up to the caller to pick the right obstack before calling this
1073 register enum tree_code code = TREE_CODE (node);
1074 register int length = 0;
1076 switch (TREE_CODE_CLASS (code))
1078 case 'd': /* A decl node */
1079 length = sizeof (struct tree_decl);
1082 case 't': /* a type node */
1083 length = sizeof (struct tree_type);
1086 case 'b': /* a lexical block node */
1087 length = sizeof (struct tree_block);
1090 case 'r': /* a reference */
1091 case 'e': /* an expression */
1092 case 's': /* an expression with side effects */
1093 case '<': /* a comparison expression */
1094 case '1': /* a unary arithmetic expression */
1095 case '2': /* a binary arithmetic expression */
1096 length = sizeof (struct tree_exp)
1097 + (tree_code_length[(int) code] - 1) * sizeof (char *);
1100 case 'c': /* a constant */
1101 /* We can't use tree_code_length for INTEGER_CST, since the number of
1102 words is machine-dependent due to varying length of HOST_WIDE_INT,
1103 which might be wider than a pointer (e.g., long long). Similarly
1104 for REAL_CST, since the number of words is machine-dependent due
1105 to varying size and alignment of `double'. */
1106 if (code == INTEGER_CST)
1107 length = sizeof (struct tree_int_cst);
1108 else if (code == REAL_CST)
1109 length = sizeof (struct tree_real_cst);
1111 length = (sizeof (struct tree_common)
1112 + tree_code_length[(int) code] * sizeof (char *));
1115 case 'x': /* something random, like an identifier. */
1116 length = sizeof (struct tree_common)
1117 + tree_code_length[(int) code] * sizeof (char *);
1118 if (code == TREE_VEC)
1119 length += (TREE_VEC_LENGTH (node) - 1) * sizeof (char *);
1122 t = (tree) obstack_alloc (current_obstack, length);
1123 memcpy (t, node, length);
1125 /* EXPR_WITH_FILE_LOCATION must keep filename info stored in TREE_CHAIN */
1126 if (TREE_CODE (node) != EXPR_WITH_FILE_LOCATION)
1128 TREE_ASM_WRITTEN (t) = 0;
1130 if (TREE_CODE_CLASS (code) == 'd')
1131 DECL_UID (t) = next_decl_uid++;
1132 else if (TREE_CODE_CLASS (code) == 't')
1134 TYPE_UID (t) = next_type_uid++;
1135 TYPE_OBSTACK (t) = current_obstack;
1137 /* The following is so that the debug code for
1138 the copy is different from the original type.
1139 The two statements usually duplicate each other
1140 (because they clear fields of the same union),
1141 but the optimizer should catch that. */
1142 TYPE_SYMTAB_POINTER (t) = 0;
1143 TYPE_SYMTAB_ADDRESS (t) = 0;
1146 TREE_PERMANENT (t) = (current_obstack == &permanent_obstack);
1151 /* Return a copy of a chain of nodes, chained through the TREE_CHAIN field.
1152 For example, this can copy a list made of TREE_LIST nodes. */
1159 register tree prev, next;
1164 head = prev = copy_node (list);
1165 next = TREE_CHAIN (list);
1168 TREE_CHAIN (prev) = copy_node (next);
1169 prev = TREE_CHAIN (prev);
1170 next = TREE_CHAIN (next);
1177 /* Return an IDENTIFIER_NODE whose name is TEXT (a null-terminated string).
1178 If an identifier with that name has previously been referred to,
1179 the same node is returned this time. */
1182 get_identifier (text)
1183 register const char *text;
1188 register int len, hash_len;
1190 /* Compute length of text in len. */
1191 len = strlen (text);
1193 /* Decide how much of that length to hash on */
1195 if (warn_id_clash && (unsigned)len > id_clash_len)
1196 hash_len = id_clash_len;
1198 /* Compute hash code */
1199 hi = hash_len * 613 + (unsigned) text[0];
1200 for (i = 1; i < hash_len; i += 2)
1201 hi = ((hi * 613) + (unsigned) (text[i]));
1203 hi &= (1 << HASHBITS) - 1;
1204 hi %= MAX_HASH_TABLE;
1206 /* Search table for identifier */
1207 for (idp = hash_table[hi]; idp; idp = TREE_CHAIN (idp))
1208 if (IDENTIFIER_LENGTH (idp) == len
1209 && IDENTIFIER_POINTER (idp)[0] == text[0]
1210 && !bcmp (IDENTIFIER_POINTER (idp), text, len))
1211 return idp; /* <-- return if found */
1213 /* Not found; optionally warn about a similar identifier */
1214 if (warn_id_clash && do_identifier_warnings && (unsigned)len >= id_clash_len)
1215 for (idp = hash_table[hi]; idp; idp = TREE_CHAIN (idp))
1216 if (!strncmp (IDENTIFIER_POINTER (idp), text, id_clash_len))
1218 warning ("`%s' and `%s' identical in first %d characters",
1219 IDENTIFIER_POINTER (idp), text, id_clash_len);
1223 if (tree_code_length[(int) IDENTIFIER_NODE] < 0)
1224 abort (); /* set_identifier_size hasn't been called. */
1226 /* Not found, create one, add to chain */
1227 idp = make_node (IDENTIFIER_NODE);
1228 IDENTIFIER_LENGTH (idp) = len;
1229 #ifdef GATHER_STATISTICS
1230 id_string_size += len;
1233 IDENTIFIER_POINTER (idp) = obstack_copy0 (&permanent_obstack, text, len);
1235 TREE_CHAIN (idp) = hash_table[hi];
1236 hash_table[hi] = idp;
1237 return idp; /* <-- return if created */
1240 /* If an identifier with the name TEXT (a null-terminated string) has
1241 previously been referred to, return that node; otherwise return
1245 maybe_get_identifier (text)
1246 register const char *text;
1251 register int len, hash_len;
1253 /* Compute length of text in len. */
1254 len = strlen (text);
1256 /* Decide how much of that length to hash on */
1258 if (warn_id_clash && (unsigned)len > id_clash_len)
1259 hash_len = id_clash_len;
1261 /* Compute hash code */
1262 hi = hash_len * 613 + (unsigned) text[0];
1263 for (i = 1; i < hash_len; i += 2)
1264 hi = ((hi * 613) + (unsigned) (text[i]));
1266 hi &= (1 << HASHBITS) - 1;
1267 hi %= MAX_HASH_TABLE;
1269 /* Search table for identifier */
1270 for (idp = hash_table[hi]; idp; idp = TREE_CHAIN (idp))
1271 if (IDENTIFIER_LENGTH (idp) == len
1272 && IDENTIFIER_POINTER (idp)[0] == text[0]
1273 && !bcmp (IDENTIFIER_POINTER (idp), text, len))
1274 return idp; /* <-- return if found */
1279 /* Enable warnings on similar identifiers (if requested).
1280 Done after the built-in identifiers are created. */
1283 start_identifier_warnings ()
1285 do_identifier_warnings = 1;
1288 /* Record the size of an identifier node for the language in use.
1289 SIZE is the total size in bytes.
1290 This is called by the language-specific files. This must be
1291 called before allocating any identifiers. */
1294 set_identifier_size (size)
1297 tree_code_length[(int) IDENTIFIER_NODE]
1298 = (size - sizeof (struct tree_common)) / sizeof (tree);
1301 /* Return a newly constructed INTEGER_CST node whose constant value
1302 is specified by the two ints LOW and HI.
1303 The TREE_TYPE is set to `int'.
1305 This function should be used via the `build_int_2' macro. */
1308 build_int_2_wide (low, hi)
1309 HOST_WIDE_INT low, hi;
1311 register tree t = make_node (INTEGER_CST);
1312 TREE_INT_CST_LOW (t) = low;
1313 TREE_INT_CST_HIGH (t) = hi;
1314 TREE_TYPE (t) = integer_type_node;
1318 /* Return a new REAL_CST node whose type is TYPE and value is D. */
1321 build_real (type, d)
1328 /* Check for valid float value for this type on this target machine;
1329 if not, can print error message and store a valid value in D. */
1330 #ifdef CHECK_FLOAT_VALUE
1331 CHECK_FLOAT_VALUE (TYPE_MODE (type), d, overflow);
1334 v = make_node (REAL_CST);
1335 TREE_TYPE (v) = type;
1336 TREE_REAL_CST (v) = d;
1337 TREE_OVERFLOW (v) = TREE_CONSTANT_OVERFLOW (v) = overflow;
1341 /* Return a new REAL_CST node whose type is TYPE
1342 and whose value is the integer value of the INTEGER_CST node I. */
1344 #if !defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
1347 real_value_from_int_cst (type, i)
1352 #ifdef REAL_ARITHMETIC
1353 if (! TREE_UNSIGNED (TREE_TYPE (i)))
1354 REAL_VALUE_FROM_INT (d, TREE_INT_CST_LOW (i), TREE_INT_CST_HIGH (i),
1357 REAL_VALUE_FROM_UNSIGNED_INT (d, TREE_INT_CST_LOW (i),
1358 TREE_INT_CST_HIGH (i), TYPE_MODE (type));
1359 #else /* not REAL_ARITHMETIC */
1360 /* Some 386 compilers mishandle unsigned int to float conversions,
1361 so introduce a temporary variable E to avoid those bugs. */
1362 if (TREE_INT_CST_HIGH (i) < 0 && ! TREE_UNSIGNED (TREE_TYPE (i)))
1366 d = (double) (~ TREE_INT_CST_HIGH (i));
1367 e = ((double) ((HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2))
1368 * (double) ((HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2)));
1370 e = (double) (unsigned HOST_WIDE_INT) (~ TREE_INT_CST_LOW (i));
1378 d = (double) (unsigned HOST_WIDE_INT) TREE_INT_CST_HIGH (i);
1379 e = ((double) ((HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2))
1380 * (double) ((HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2)));
1382 e = (double) (unsigned HOST_WIDE_INT) TREE_INT_CST_LOW (i);
1385 #endif /* not REAL_ARITHMETIC */
1398 build_real_from_int_cst_1 (data)
1401 struct brfic_args * args = (struct brfic_args *) data;
1403 #ifdef REAL_ARITHMETIC
1404 args->d = real_value_from_int_cst (args->type, args->i);
1407 REAL_VALUE_TRUNCATE (TYPE_MODE (args->type),
1408 real_value_from_int_cst (args->type, args->i));
1412 /* This function can't be implemented if we can't do arithmetic
1413 on the float representation. */
1416 build_real_from_int_cst (type, i)
1421 int overflow = TREE_OVERFLOW (i);
1423 struct brfic_args args;
1425 v = make_node (REAL_CST);
1426 TREE_TYPE (v) = type;
1428 /* Setup input for build_real_from_int_cst_1() */
1432 if (do_float_handler (build_real_from_int_cst_1, (PTR) &args))
1434 /* Receive output from build_real_from_int_cst_1() */
1439 /* We got an exception from build_real_from_int_cst_1() */
1444 /* Check for valid float value for this type on this target machine. */
1446 #ifdef CHECK_FLOAT_VALUE
1447 CHECK_FLOAT_VALUE (TYPE_MODE (type), d, overflow);
1450 TREE_REAL_CST (v) = d;
1451 TREE_OVERFLOW (v) = TREE_CONSTANT_OVERFLOW (v) = overflow;
1455 #endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */
1457 /* Return a newly constructed STRING_CST node whose value is
1458 the LEN characters at STR.
1459 The TREE_TYPE is not initialized. */
1462 build_string (len, str)
1466 /* Put the string in saveable_obstack since it will be placed in the RTL
1467 for an "asm" statement and will also be kept around a while if
1468 deferring constant output in varasm.c. */
1470 register tree s = make_node (STRING_CST);
1471 TREE_STRING_LENGTH (s) = len;
1472 TREE_STRING_POINTER (s) = obstack_copy0 (saveable_obstack, str, len);
1476 /* Return a newly constructed COMPLEX_CST node whose value is
1477 specified by the real and imaginary parts REAL and IMAG.
1478 Both REAL and IMAG should be constant nodes. TYPE, if specified,
1479 will be the type of the COMPLEX_CST; otherwise a new type will be made. */
1482 build_complex (type, real, imag)
1486 register tree t = make_node (COMPLEX_CST);
1488 TREE_REALPART (t) = real;
1489 TREE_IMAGPART (t) = imag;
1490 TREE_TYPE (t) = type ? type : build_complex_type (TREE_TYPE (real));
1491 TREE_OVERFLOW (t) = TREE_OVERFLOW (real) | TREE_OVERFLOW (imag);
1492 TREE_CONSTANT_OVERFLOW (t)
1493 = TREE_CONSTANT_OVERFLOW (real) | TREE_CONSTANT_OVERFLOW (imag);
1497 /* Build a newly constructed TREE_VEC node of length LEN. */
1504 register int length = (len-1) * sizeof (tree) + sizeof (struct tree_vec);
1505 register struct obstack *obstack = current_obstack;
1507 #ifdef GATHER_STATISTICS
1508 tree_node_counts[(int)vec_kind]++;
1509 tree_node_sizes[(int)vec_kind] += length;
1512 t = (tree) obstack_alloc (obstack, length);
1513 bzero ((PTR) t, length);
1515 TREE_SET_CODE (t, TREE_VEC);
1516 TREE_VEC_LENGTH (t) = len;
1517 if (obstack == &permanent_obstack)
1518 TREE_PERMANENT (t) = 1;
1523 /* Return 1 if EXPR is the integer constant zero or a complex constant
1527 integer_zerop (expr)
1532 return ((TREE_CODE (expr) == INTEGER_CST
1533 && ! TREE_CONSTANT_OVERFLOW (expr)
1534 && TREE_INT_CST_LOW (expr) == 0
1535 && TREE_INT_CST_HIGH (expr) == 0)
1536 || (TREE_CODE (expr) == COMPLEX_CST
1537 && integer_zerop (TREE_REALPART (expr))
1538 && integer_zerop (TREE_IMAGPART (expr))));
1541 /* Return 1 if EXPR is the integer constant one or the corresponding
1542 complex constant. */
1550 return ((TREE_CODE (expr) == INTEGER_CST
1551 && ! TREE_CONSTANT_OVERFLOW (expr)
1552 && TREE_INT_CST_LOW (expr) == 1
1553 && TREE_INT_CST_HIGH (expr) == 0)
1554 || (TREE_CODE (expr) == COMPLEX_CST
1555 && integer_onep (TREE_REALPART (expr))
1556 && integer_zerop (TREE_IMAGPART (expr))));
1559 /* Return 1 if EXPR is an integer containing all 1's in as much precision as
1560 it contains. Likewise for the corresponding complex constant. */
1563 integer_all_onesp (expr)
1571 if (TREE_CODE (expr) == COMPLEX_CST
1572 && integer_all_onesp (TREE_REALPART (expr))
1573 && integer_zerop (TREE_IMAGPART (expr)))
1576 else if (TREE_CODE (expr) != INTEGER_CST
1577 || TREE_CONSTANT_OVERFLOW (expr))
1580 uns = TREE_UNSIGNED (TREE_TYPE (expr));
1582 return TREE_INT_CST_LOW (expr) == -1 && TREE_INT_CST_HIGH (expr) == -1;
1584 /* Note that using TYPE_PRECISION here is wrong. We care about the
1585 actual bits, not the (arbitrary) range of the type. */
1586 prec = GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (expr)));
1587 if (prec >= HOST_BITS_PER_WIDE_INT)
1589 int high_value, shift_amount;
1591 shift_amount = prec - HOST_BITS_PER_WIDE_INT;
1593 if (shift_amount > HOST_BITS_PER_WIDE_INT)
1594 /* Can not handle precisions greater than twice the host int size. */
1596 else if (shift_amount == HOST_BITS_PER_WIDE_INT)
1597 /* Shifting by the host word size is undefined according to the ANSI
1598 standard, so we must handle this as a special case. */
1601 high_value = ((HOST_WIDE_INT) 1 << shift_amount) - 1;
1603 return TREE_INT_CST_LOW (expr) == -1
1604 && TREE_INT_CST_HIGH (expr) == high_value;
1607 return TREE_INT_CST_LOW (expr) == ((HOST_WIDE_INT) 1 << prec) - 1;
1610 /* Return 1 if EXPR is an integer constant that is a power of 2 (i.e., has only
1614 integer_pow2p (expr)
1618 HOST_WIDE_INT high, low;
1622 if (TREE_CODE (expr) == COMPLEX_CST
1623 && integer_pow2p (TREE_REALPART (expr))
1624 && integer_zerop (TREE_IMAGPART (expr)))
1627 if (TREE_CODE (expr) != INTEGER_CST || TREE_CONSTANT_OVERFLOW (expr))
1630 prec = (POINTER_TYPE_P (TREE_TYPE (expr))
1631 ? POINTER_SIZE : TYPE_PRECISION (TREE_TYPE (expr)));
1632 high = TREE_INT_CST_HIGH (expr);
1633 low = TREE_INT_CST_LOW (expr);
1635 /* First clear all bits that are beyond the type's precision in case
1636 we've been sign extended. */
1638 if (prec == 2 * HOST_BITS_PER_WIDE_INT)
1640 else if (prec > HOST_BITS_PER_WIDE_INT)
1641 high &= ~((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
1645 if (prec < HOST_BITS_PER_WIDE_INT)
1646 low &= ~((HOST_WIDE_INT) (-1) << prec);
1649 if (high == 0 && low == 0)
1652 return ((high == 0 && (low & (low - 1)) == 0)
1653 || (low == 0 && (high & (high - 1)) == 0));
1656 /* Return the power of two represented by a tree node known to be a
1664 HOST_WIDE_INT high, low;
1668 if (TREE_CODE (expr) == COMPLEX_CST)
1669 return tree_log2 (TREE_REALPART (expr));
1671 prec = (POINTER_TYPE_P (TREE_TYPE (expr))
1672 ? POINTER_SIZE : TYPE_PRECISION (TREE_TYPE (expr)));
1674 high = TREE_INT_CST_HIGH (expr);
1675 low = TREE_INT_CST_LOW (expr);
1677 /* First clear all bits that are beyond the type's precision in case
1678 we've been sign extended. */
1680 if (prec == 2 * HOST_BITS_PER_WIDE_INT)
1682 else if (prec > HOST_BITS_PER_WIDE_INT)
1683 high &= ~((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
1687 if (prec < HOST_BITS_PER_WIDE_INT)
1688 low &= ~((HOST_WIDE_INT) (-1) << prec);
1691 return (high != 0 ? HOST_BITS_PER_WIDE_INT + exact_log2 (high)
1692 : exact_log2 (low));
1695 /* Return 1 if EXPR is the real constant zero. */
1703 return ((TREE_CODE (expr) == REAL_CST
1704 && ! TREE_CONSTANT_OVERFLOW (expr)
1705 && REAL_VALUES_EQUAL (TREE_REAL_CST (expr), dconst0))
1706 || (TREE_CODE (expr) == COMPLEX_CST
1707 && real_zerop (TREE_REALPART (expr))
1708 && real_zerop (TREE_IMAGPART (expr))));
1711 /* Return 1 if EXPR is the real constant one in real or complex form. */
1719 return ((TREE_CODE (expr) == REAL_CST
1720 && ! TREE_CONSTANT_OVERFLOW (expr)
1721 && REAL_VALUES_EQUAL (TREE_REAL_CST (expr), dconst1))
1722 || (TREE_CODE (expr) == COMPLEX_CST
1723 && real_onep (TREE_REALPART (expr))
1724 && real_zerop (TREE_IMAGPART (expr))));
1727 /* Return 1 if EXPR is the real constant two. */
1735 return ((TREE_CODE (expr) == REAL_CST
1736 && ! TREE_CONSTANT_OVERFLOW (expr)
1737 && REAL_VALUES_EQUAL (TREE_REAL_CST (expr), dconst2))
1738 || (TREE_CODE (expr) == COMPLEX_CST
1739 && real_twop (TREE_REALPART (expr))
1740 && real_zerop (TREE_IMAGPART (expr))));
1743 /* Nonzero if EXP is a constant or a cast of a constant. */
1746 really_constant_p (exp)
1749 /* This is not quite the same as STRIP_NOPS. It does more. */
1750 while (TREE_CODE (exp) == NOP_EXPR
1751 || TREE_CODE (exp) == CONVERT_EXPR
1752 || TREE_CODE (exp) == NON_LVALUE_EXPR)
1753 exp = TREE_OPERAND (exp, 0);
1754 return TREE_CONSTANT (exp);
1757 /* Return first list element whose TREE_VALUE is ELEM.
1758 Return 0 if ELEM is not in LIST. */
1761 value_member (elem, list)
1766 if (elem == TREE_VALUE (list))
1768 list = TREE_CHAIN (list);
1773 /* Return first list element whose TREE_PURPOSE is ELEM.
1774 Return 0 if ELEM is not in LIST. */
1777 purpose_member (elem, list)
1782 if (elem == TREE_PURPOSE (list))
1784 list = TREE_CHAIN (list);
1789 /* Return first list element whose BINFO_TYPE is ELEM.
1790 Return 0 if ELEM is not in LIST. */
1793 binfo_member (elem, list)
1798 if (elem == BINFO_TYPE (list))
1800 list = TREE_CHAIN (list);
1805 /* Return nonzero if ELEM is part of the chain CHAIN. */
1808 chain_member (elem, chain)
1815 chain = TREE_CHAIN (chain);
1821 /* Return nonzero if ELEM is equal to TREE_VALUE (CHAIN) for any piece of
1823 /* ??? This function was added for machine specific attributes but is no
1824 longer used. It could be deleted if we could confirm all front ends
1828 chain_member_value (elem, chain)
1833 if (elem == TREE_VALUE (chain))
1835 chain = TREE_CHAIN (chain);
1841 /* Return nonzero if ELEM is equal to TREE_PURPOSE (CHAIN)
1842 for any piece of chain CHAIN. */
1843 /* ??? This function was added for machine specific attributes but is no
1844 longer used. It could be deleted if we could confirm all front ends
1848 chain_member_purpose (elem, chain)
1853 if (elem == TREE_PURPOSE (chain))
1855 chain = TREE_CHAIN (chain);
1861 /* Return the length of a chain of nodes chained through TREE_CHAIN.
1862 We expect a null pointer to mark the end of the chain.
1863 This is the Lisp primitive `length'. */
1870 register int len = 0;
1872 for (tail = t; tail; tail = TREE_CHAIN (tail))
1878 /* Concatenate two chains of nodes (chained through TREE_CHAIN)
1879 by modifying the last node in chain 1 to point to chain 2.
1880 This is the Lisp primitive `nconc'. */
1890 #ifdef ENABLE_CHECKING
1894 for (t1 = op1; TREE_CHAIN (t1); t1 = TREE_CHAIN (t1))
1896 TREE_CHAIN (t1) = op2;
1897 #ifdef ENABLE_CHECKING
1898 for (t2 = op2; t2; t2 = TREE_CHAIN (t2))
1900 abort (); /* Circularity created. */
1907 /* Return the last node in a chain of nodes (chained through TREE_CHAIN). */
1911 register tree chain;
1915 while ((next = TREE_CHAIN (chain)))
1920 /* Reverse the order of elements in the chain T,
1921 and return the new head of the chain (old last element). */
1927 register tree prev = 0, decl, next;
1928 for (decl = t; decl; decl = next)
1930 next = TREE_CHAIN (decl);
1931 TREE_CHAIN (decl) = prev;
1937 /* Given a chain CHAIN of tree nodes,
1938 construct and return a list of those nodes. */
1944 tree result = NULL_TREE;
1945 tree in_tail = chain;
1946 tree out_tail = NULL_TREE;
1950 tree next = tree_cons (NULL_TREE, in_tail, NULL_TREE);
1952 TREE_CHAIN (out_tail) = next;
1956 in_tail = TREE_CHAIN (in_tail);
1962 /* Return a newly created TREE_LIST node whose
1963 purpose and value fields are PARM and VALUE. */
1966 build_tree_list (parm, value)
1969 register tree t = make_node (TREE_LIST);
1970 TREE_PURPOSE (t) = parm;
1971 TREE_VALUE (t) = value;
1975 /* Similar, but build on the temp_decl_obstack. */
1978 build_decl_list (parm, value)
1982 register struct obstack *ambient_obstack = current_obstack;
1983 current_obstack = &temp_decl_obstack;
1984 node = build_tree_list (parm, value);
1985 current_obstack = ambient_obstack;
1989 /* Similar, but build on the expression_obstack. */
1992 build_expr_list (parm, value)
1996 register struct obstack *ambient_obstack = current_obstack;
1997 current_obstack = expression_obstack;
1998 node = build_tree_list (parm, value);
1999 current_obstack = ambient_obstack;
2003 /* Return a newly created TREE_LIST node whose
2004 purpose and value fields are PARM and VALUE
2005 and whose TREE_CHAIN is CHAIN. */
2008 tree_cons (purpose, value, chain)
2009 tree purpose, value, chain;
2012 register tree node = make_node (TREE_LIST);
2015 register tree node = (tree) obstack_alloc (current_obstack, sizeof (struct tree_list));
2016 #ifdef GATHER_STATISTICS
2017 tree_node_counts[(int)x_kind]++;
2018 tree_node_sizes[(int)x_kind] += sizeof (struct tree_list);
2021 for (i = (sizeof (struct tree_common) / sizeof (int)) - 1; i >= 0; i--)
2022 ((int *) node)[i] = 0;
2024 TREE_SET_CODE (node, TREE_LIST);
2025 if (current_obstack == &permanent_obstack)
2026 TREE_PERMANENT (node) = 1;
2029 TREE_CHAIN (node) = chain;
2030 TREE_PURPOSE (node) = purpose;
2031 TREE_VALUE (node) = value;
2035 /* Similar, but build on the temp_decl_obstack. */
2038 decl_tree_cons (purpose, value, chain)
2039 tree purpose, value, chain;
2042 register struct obstack *ambient_obstack = current_obstack;
2043 current_obstack = &temp_decl_obstack;
2044 node = tree_cons (purpose, value, chain);
2045 current_obstack = ambient_obstack;
2049 /* Similar, but build on the expression_obstack. */
2052 expr_tree_cons (purpose, value, chain)
2053 tree purpose, value, chain;
2056 register struct obstack *ambient_obstack = current_obstack;
2057 current_obstack = expression_obstack;
2058 node = tree_cons (purpose, value, chain);
2059 current_obstack = ambient_obstack;
2063 /* Same as `tree_cons' but make a permanent object. */
2066 perm_tree_cons (purpose, value, chain)
2067 tree purpose, value, chain;
2070 register struct obstack *ambient_obstack = current_obstack;
2071 current_obstack = &permanent_obstack;
2073 node = tree_cons (purpose, value, chain);
2074 current_obstack = ambient_obstack;
2078 /* Same as `tree_cons', but make this node temporary, regardless. */
2081 temp_tree_cons (purpose, value, chain)
2082 tree purpose, value, chain;
2085 register struct obstack *ambient_obstack = current_obstack;
2086 current_obstack = &temporary_obstack;
2088 node = tree_cons (purpose, value, chain);
2089 current_obstack = ambient_obstack;
2093 /* Same as `tree_cons', but save this node if the function's RTL is saved. */
2096 saveable_tree_cons (purpose, value, chain)
2097 tree purpose, value, chain;
2100 register struct obstack *ambient_obstack = current_obstack;
2101 current_obstack = saveable_obstack;
2103 node = tree_cons (purpose, value, chain);
2104 current_obstack = ambient_obstack;
2108 /* Return the size nominally occupied by an object of type TYPE
2109 when it resides in memory. The value is measured in units of bytes,
2110 and its data type is that normally used for type sizes
2111 (which is the first type created by make_signed_type or
2112 make_unsigned_type). */
2115 size_in_bytes (type)
2120 if (type == error_mark_node)
2121 return integer_zero_node;
2123 type = TYPE_MAIN_VARIANT (type);
2124 t = TYPE_SIZE_UNIT (type);
2127 incomplete_type_error (NULL_TREE, type);
2128 return integer_zero_node;
2130 if (TREE_CODE (t) == INTEGER_CST)
2131 force_fit_type (t, 0);
2136 /* Return the size of TYPE (in bytes) as a wide integer
2137 or return -1 if the size can vary or is larger than an integer. */
2140 int_size_in_bytes (type)
2145 if (type == error_mark_node)
2148 type = TYPE_MAIN_VARIANT (type);
2149 t = TYPE_SIZE_UNIT (type);
2151 || TREE_CODE (t) != INTEGER_CST
2152 || TREE_INT_CST_HIGH (t) != 0)
2155 return TREE_INT_CST_LOW (t);
2158 /* Return, as a tree node, the number of elements for TYPE (which is an
2159 ARRAY_TYPE) minus one. This counts only elements of the top array.
2161 Don't let any SAVE_EXPRs escape; if we are called as part of a cleanup
2162 action, they would get unsaved. */
2165 array_type_nelts (type)
2168 tree index_type, min, max;
2170 /* If they did it with unspecified bounds, then we should have already
2171 given an error about it before we got here. */
2172 if (! TYPE_DOMAIN (type))
2173 return error_mark_node;
2175 index_type = TYPE_DOMAIN (type);
2176 min = TYPE_MIN_VALUE (index_type);
2177 max = TYPE_MAX_VALUE (index_type);
2179 if (! TREE_CONSTANT (min))
2182 if (TREE_CODE (min) == SAVE_EXPR && SAVE_EXPR_RTL (min))
2183 min = build (RTL_EXPR, TREE_TYPE (TYPE_MIN_VALUE (index_type)), 0,
2184 SAVE_EXPR_RTL (min));
2186 min = TYPE_MIN_VALUE (index_type);
2189 if (! TREE_CONSTANT (max))
2192 if (TREE_CODE (max) == SAVE_EXPR && SAVE_EXPR_RTL (max))
2193 max = build (RTL_EXPR, TREE_TYPE (TYPE_MAX_VALUE (index_type)), 0,
2194 SAVE_EXPR_RTL (max));
2196 max = TYPE_MAX_VALUE (index_type);
2199 return (integer_zerop (min)
2201 : fold (build (MINUS_EXPR, TREE_TYPE (max), max, min)));
2204 /* Return nonzero if arg is static -- a reference to an object in
2205 static storage. This is not the same as the C meaning of `static'. */
2211 switch (TREE_CODE (arg))
2214 /* Nested functions aren't static, since taking their address
2215 involves a trampoline. */
2216 return (decl_function_context (arg) == 0 || DECL_NO_STATIC_CHAIN (arg))
2217 && ! DECL_NON_ADDR_CONST_P (arg);
2220 return (TREE_STATIC (arg) || DECL_EXTERNAL (arg))
2221 && ! DECL_NON_ADDR_CONST_P (arg);
2224 return TREE_STATIC (arg);
2229 /* If we are referencing a bitfield, we can't evaluate an
2230 ADDR_EXPR at compile time and so it isn't a constant. */
2232 return (! DECL_BIT_FIELD (TREE_OPERAND (arg, 1))
2233 && staticp (TREE_OPERAND (arg, 0)));
2239 /* This case is technically correct, but results in setting
2240 TREE_CONSTANT on ADDR_EXPRs that cannot be evaluated at
2243 return TREE_CONSTANT (TREE_OPERAND (arg, 0));
2247 if (TREE_CODE (TYPE_SIZE (TREE_TYPE (arg))) == INTEGER_CST
2248 && TREE_CODE (TREE_OPERAND (arg, 1)) == INTEGER_CST)
2249 return staticp (TREE_OPERAND (arg, 0));
2256 /* Wrap a SAVE_EXPR around EXPR, if appropriate.
2257 Do this to any expression which may be used in more than one place,
2258 but must be evaluated only once.
2260 Normally, expand_expr would reevaluate the expression each time.
2261 Calling save_expr produces something that is evaluated and recorded
2262 the first time expand_expr is called on it. Subsequent calls to
2263 expand_expr just reuse the recorded value.
2265 The call to expand_expr that generates code that actually computes
2266 the value is the first call *at compile time*. Subsequent calls
2267 *at compile time* generate code to use the saved value.
2268 This produces correct result provided that *at run time* control
2269 always flows through the insns made by the first expand_expr
2270 before reaching the other places where the save_expr was evaluated.
2271 You, the caller of save_expr, must make sure this is so.
2273 Constants, and certain read-only nodes, are returned with no
2274 SAVE_EXPR because that is safe. Expressions containing placeholders
2275 are not touched; see tree.def for an explanation of what these
2282 register tree t = fold (expr);
2284 /* We don't care about whether this can be used as an lvalue in this
2286 while (TREE_CODE (t) == NON_LVALUE_EXPR)
2287 t = TREE_OPERAND (t, 0);
2289 /* If the tree evaluates to a constant, then we don't want to hide that
2290 fact (i.e. this allows further folding, and direct checks for constants).
2291 However, a read-only object that has side effects cannot be bypassed.
2292 Since it is no problem to reevaluate literals, we just return the
2295 if (TREE_CONSTANT (t) || (TREE_READONLY (t) && ! TREE_SIDE_EFFECTS (t))
2296 || TREE_CODE (t) == SAVE_EXPR || TREE_CODE (t) == ERROR_MARK)
2299 /* If T contains a PLACEHOLDER_EXPR, we must evaluate it each time, since
2300 it means that the size or offset of some field of an object depends on
2301 the value within another field.
2303 Note that it must not be the case that T contains both a PLACEHOLDER_EXPR
2304 and some variable since it would then need to be both evaluated once and
2305 evaluated more than once. Front-ends must assure this case cannot
2306 happen by surrounding any such subexpressions in their own SAVE_EXPR
2307 and forcing evaluation at the proper time. */
2308 if (contains_placeholder_p (t))
2311 t = build (SAVE_EXPR, TREE_TYPE (expr), t, current_function_decl, NULL_TREE);
2313 /* This expression might be placed ahead of a jump to ensure that the
2314 value was computed on both sides of the jump. So make sure it isn't
2315 eliminated as dead. */
2316 TREE_SIDE_EFFECTS (t) = 1;
2320 /* Arrange for an expression to be expanded multiple independent
2321 times. This is useful for cleanup actions, as the backend can
2322 expand them multiple times in different places. */
2330 /* If this is already protected, no sense in protecting it again. */
2331 if (TREE_CODE (expr) == UNSAVE_EXPR)
2334 t = build1 (UNSAVE_EXPR, TREE_TYPE (expr), expr);
2335 TREE_SIDE_EFFECTS (t) = TREE_SIDE_EFFECTS (expr);
2339 /* Returns the index of the first non-tree operand for CODE, or the number
2340 of operands if all are trees. */
2344 enum tree_code code;
2350 case GOTO_SUBROUTINE_EXPR:
2355 case WITH_CLEANUP_EXPR:
2356 /* Should be defined to be 2. */
2358 case METHOD_CALL_EXPR:
2361 return tree_code_length [(int) code];
2365 /* Modify a tree in place so that all the evaluate only once things
2366 are cleared out. Return the EXPR given.
2368 LANG_UNSAVE_EXPR_NOW, if set, is a pointer to a function to handle
2369 language specific nodes.
2373 unsave_expr_now (expr)
2376 enum tree_code code;
2380 if (expr == NULL_TREE)
2383 code = TREE_CODE (expr);
2384 first_rtl = first_rtl_op (code);
2388 SAVE_EXPR_RTL (expr) = 0;
2392 TREE_OPERAND (expr, 1) = TREE_OPERAND (expr, 3);
2393 TREE_OPERAND (expr, 3) = NULL_TREE;
2397 /* I don't yet know how to emit a sequence multiple times. */
2398 if (RTL_EXPR_SEQUENCE (expr) != 0)
2403 CALL_EXPR_RTL (expr) = 0;
2404 if (TREE_OPERAND (expr, 1)
2405 && TREE_CODE (TREE_OPERAND (expr, 1)) == TREE_LIST)
2407 tree exp = TREE_OPERAND (expr, 1);
2410 unsave_expr_now (TREE_VALUE (exp));
2411 exp = TREE_CHAIN (exp);
2417 if (lang_unsave_expr_now)
2418 (*lang_unsave_expr_now) (expr);
2422 switch (TREE_CODE_CLASS (code))
2424 case 'c': /* a constant */
2425 case 't': /* a type node */
2426 case 'x': /* something random, like an identifier or an ERROR_MARK. */
2427 case 'd': /* A decl node */
2428 case 'b': /* A block node */
2431 case 'e': /* an expression */
2432 case 'r': /* a reference */
2433 case 's': /* an expression with side effects */
2434 case '<': /* a comparison expression */
2435 case '2': /* a binary arithmetic expression */
2436 case '1': /* a unary arithmetic expression */
2437 for (i = first_rtl - 1; i >= 0; i--)
2438 unsave_expr_now (TREE_OPERAND (expr, i));
2446 /* Return 1 if EXP contains a PLACEHOLDER_EXPR; i.e., if it represents a size
2447 or offset that depends on a field within a record. */
2450 contains_placeholder_p (exp)
2453 register enum tree_code code = TREE_CODE (exp);
2456 /* If we have a WITH_RECORD_EXPR, it "cancels" any PLACEHOLDER_EXPR
2457 in it since it is supplying a value for it. */
2458 if (code == WITH_RECORD_EXPR)
2460 else if (code == PLACEHOLDER_EXPR)
2463 switch (TREE_CODE_CLASS (code))
2466 /* Don't look at any PLACEHOLDER_EXPRs that might be in index or bit
2467 position computations since they will be converted into a
2468 WITH_RECORD_EXPR involving the reference, which will assume
2469 here will be valid. */
2470 return contains_placeholder_p (TREE_OPERAND (exp, 0));
2473 if (code == TREE_LIST)
2474 return (contains_placeholder_p (TREE_VALUE (exp))
2475 || (TREE_CHAIN (exp) != 0
2476 && contains_placeholder_p (TREE_CHAIN (exp))));
2485 /* Ignoring the first operand isn't quite right, but works best. */
2486 return contains_placeholder_p (TREE_OPERAND (exp, 1));
2493 return (contains_placeholder_p (TREE_OPERAND (exp, 0))
2494 || contains_placeholder_p (TREE_OPERAND (exp, 1))
2495 || contains_placeholder_p (TREE_OPERAND (exp, 2)));
2498 /* If we already know this doesn't have a placeholder, don't
2500 if (SAVE_EXPR_NOPLACEHOLDER (exp) || SAVE_EXPR_RTL (exp) != 0)
2503 SAVE_EXPR_NOPLACEHOLDER (exp) = 1;
2504 result = contains_placeholder_p (TREE_OPERAND (exp, 0));
2506 SAVE_EXPR_NOPLACEHOLDER (exp) = 0;
2511 return (TREE_OPERAND (exp, 1) != 0
2512 && contains_placeholder_p (TREE_OPERAND (exp, 1)));
2518 switch (tree_code_length[(int) code])
2521 return contains_placeholder_p (TREE_OPERAND (exp, 0));
2523 return (contains_placeholder_p (TREE_OPERAND (exp, 0))
2524 || contains_placeholder_p (TREE_OPERAND (exp, 1)));
2535 /* Return 1 if EXP contains any expressions that produce cleanups for an
2536 outer scope to deal with. Used by fold. */
2544 if (! TREE_SIDE_EFFECTS (exp))
2547 switch (TREE_CODE (exp))
2550 case GOTO_SUBROUTINE_EXPR:
2551 case WITH_CLEANUP_EXPR:
2554 case CLEANUP_POINT_EXPR:
2558 for (exp = TREE_OPERAND (exp, 1); exp; exp = TREE_CHAIN (exp))
2560 cmp = has_cleanups (TREE_VALUE (exp));
2570 /* This general rule works for most tree codes. All exceptions should be
2571 handled above. If this is a language-specific tree code, we can't
2572 trust what might be in the operand, so say we don't know
2574 if ((int) TREE_CODE (exp) >= (int) LAST_AND_UNUSED_TREE_CODE)
2577 nops = first_rtl_op (TREE_CODE (exp));
2578 for (i = 0; i < nops; i++)
2579 if (TREE_OPERAND (exp, i) != 0)
2581 int type = TREE_CODE_CLASS (TREE_CODE (TREE_OPERAND (exp, i)));
2582 if (type == 'e' || type == '<' || type == '1' || type == '2'
2583 || type == 'r' || type == 's')
2585 cmp = has_cleanups (TREE_OPERAND (exp, i));
2594 /* Given a tree EXP, a FIELD_DECL F, and a replacement value R,
2595 return a tree with all occurrences of references to F in a
2596 PLACEHOLDER_EXPR replaced by R. Note that we assume here that EXP
2597 contains only arithmetic expressions or a CALL_EXPR with a
2598 PLACEHOLDER_EXPR occurring only in its arglist. */
2601 substitute_in_expr (exp, f, r)
2606 enum tree_code code = TREE_CODE (exp);
2611 switch (TREE_CODE_CLASS (code))
2618 if (code == PLACEHOLDER_EXPR)
2620 else if (code == TREE_LIST)
2622 op0 = (TREE_CHAIN (exp) == 0
2623 ? 0 : substitute_in_expr (TREE_CHAIN (exp), f, r));
2624 op1 = substitute_in_expr (TREE_VALUE (exp), f, r);
2625 if (op0 == TREE_CHAIN (exp) && op1 == TREE_VALUE (exp))
2628 return tree_cons (TREE_PURPOSE (exp), op1, op0);
2637 switch (tree_code_length[(int) code])
2640 op0 = substitute_in_expr (TREE_OPERAND (exp, 0), f, r);
2641 if (op0 == TREE_OPERAND (exp, 0))
2644 new = fold (build1 (code, TREE_TYPE (exp), op0));
2648 /* An RTL_EXPR cannot contain a PLACEHOLDER_EXPR; a CONSTRUCTOR
2649 could, but we don't support it. */
2650 if (code == RTL_EXPR)
2652 else if (code == CONSTRUCTOR)
2655 op0 = substitute_in_expr (TREE_OPERAND (exp, 0), f, r);
2656 op1 = substitute_in_expr (TREE_OPERAND (exp, 1), f, r);
2657 if (op0 == TREE_OPERAND (exp, 0) && op1 == TREE_OPERAND (exp, 1))
2660 new = fold (build (code, TREE_TYPE (exp), op0, op1));
2664 /* It cannot be that anything inside a SAVE_EXPR contains a
2665 PLACEHOLDER_EXPR. */
2666 if (code == SAVE_EXPR)
2669 else if (code == CALL_EXPR)
2671 op1 = substitute_in_expr (TREE_OPERAND (exp, 1), f, r);
2672 if (op1 == TREE_OPERAND (exp, 1))
2675 return build (code, TREE_TYPE (exp),
2676 TREE_OPERAND (exp, 0), op1, NULL_TREE);
2679 else if (code != COND_EXPR)
2682 op0 = substitute_in_expr (TREE_OPERAND (exp, 0), f, r);
2683 op1 = substitute_in_expr (TREE_OPERAND (exp, 1), f, r);
2684 op2 = substitute_in_expr (TREE_OPERAND (exp, 2), f, r);
2685 if (op0 == TREE_OPERAND (exp, 0) && op1 == TREE_OPERAND (exp, 1)
2686 && op2 == TREE_OPERAND (exp, 2))
2689 new = fold (build (code, TREE_TYPE (exp), op0, op1, op2));
2702 /* If this expression is getting a value from a PLACEHOLDER_EXPR
2703 and it is the right field, replace it with R. */
2704 for (inner = TREE_OPERAND (exp, 0);
2705 TREE_CODE_CLASS (TREE_CODE (inner)) == 'r';
2706 inner = TREE_OPERAND (inner, 0))
2708 if (TREE_CODE (inner) == PLACEHOLDER_EXPR
2709 && TREE_OPERAND (exp, 1) == f)
2712 /* If this expression hasn't been completed let, leave it
2714 if (TREE_CODE (inner) == PLACEHOLDER_EXPR
2715 && TREE_TYPE (inner) == 0)
2718 op0 = substitute_in_expr (TREE_OPERAND (exp, 0), f, r);
2719 if (op0 == TREE_OPERAND (exp, 0))
2722 new = fold (build (code, TREE_TYPE (exp), op0,
2723 TREE_OPERAND (exp, 1)));
2727 op0 = substitute_in_expr (TREE_OPERAND (exp, 0), f, r);
2728 op1 = substitute_in_expr (TREE_OPERAND (exp, 1), f, r);
2729 op2 = substitute_in_expr (TREE_OPERAND (exp, 2), f, r);
2730 if (op0 == TREE_OPERAND (exp, 0) && op1 == TREE_OPERAND (exp, 1)
2731 && op2 == TREE_OPERAND (exp, 2))
2734 new = fold (build (code, TREE_TYPE (exp), op0, op1, op2));
2739 op0 = substitute_in_expr (TREE_OPERAND (exp, 0), f, r);
2740 if (op0 == TREE_OPERAND (exp, 0))
2743 new = fold (build1 (code, TREE_TYPE (exp), op0));
2755 TREE_READONLY (new) = TREE_READONLY (exp);
2759 /* Stabilize a reference so that we can use it any number of times
2760 without causing its operands to be evaluated more than once.
2761 Returns the stabilized reference. This works by means of save_expr,
2762 so see the caveats in the comments about save_expr.
2764 Also allows conversion expressions whose operands are references.
2765 Any other kind of expression is returned unchanged. */
2768 stabilize_reference (ref)
2771 register tree result;
2772 register enum tree_code code = TREE_CODE (ref);
2779 /* No action is needed in this case. */
2785 case FIX_TRUNC_EXPR:
2786 case FIX_FLOOR_EXPR:
2787 case FIX_ROUND_EXPR:
2789 result = build_nt (code, stabilize_reference (TREE_OPERAND (ref, 0)));
2793 result = build_nt (INDIRECT_REF,
2794 stabilize_reference_1 (TREE_OPERAND (ref, 0)));
2798 result = build_nt (COMPONENT_REF,
2799 stabilize_reference (TREE_OPERAND (ref, 0)),
2800 TREE_OPERAND (ref, 1));
2804 result = build_nt (BIT_FIELD_REF,
2805 stabilize_reference (TREE_OPERAND (ref, 0)),
2806 stabilize_reference_1 (TREE_OPERAND (ref, 1)),
2807 stabilize_reference_1 (TREE_OPERAND (ref, 2)));
2811 result = build_nt (ARRAY_REF,
2812 stabilize_reference (TREE_OPERAND (ref, 0)),
2813 stabilize_reference_1 (TREE_OPERAND (ref, 1)));
2817 /* We cannot wrap the first expression in a SAVE_EXPR, as then
2818 it wouldn't be ignored. This matters when dealing with
2820 return stabilize_reference_1 (ref);
2823 result = build1 (INDIRECT_REF, TREE_TYPE (ref),
2824 save_expr (build1 (ADDR_EXPR,
2825 build_pointer_type (TREE_TYPE (ref)),
2830 /* If arg isn't a kind of lvalue we recognize, make no change.
2831 Caller should recognize the error for an invalid lvalue. */
2836 return error_mark_node;
2839 TREE_TYPE (result) = TREE_TYPE (ref);
2840 TREE_READONLY (result) = TREE_READONLY (ref);
2841 TREE_SIDE_EFFECTS (result) = TREE_SIDE_EFFECTS (ref);
2842 TREE_THIS_VOLATILE (result) = TREE_THIS_VOLATILE (ref);
2843 TREE_RAISES (result) = TREE_RAISES (ref);
2848 /* Subroutine of stabilize_reference; this is called for subtrees of
2849 references. Any expression with side-effects must be put in a SAVE_EXPR
2850 to ensure that it is only evaluated once.
2852 We don't put SAVE_EXPR nodes around everything, because assigning very
2853 simple expressions to temporaries causes us to miss good opportunities
2854 for optimizations. Among other things, the opportunity to fold in the
2855 addition of a constant into an addressing mode often gets lost, e.g.
2856 "y[i+1] += x;". In general, we take the approach that we should not make
2857 an assignment unless we are forced into it - i.e., that any non-side effect
2858 operator should be allowed, and that cse should take care of coalescing
2859 multiple utterances of the same expression should that prove fruitful. */
2862 stabilize_reference_1 (e)
2865 register tree result;
2866 register enum tree_code code = TREE_CODE (e);
2868 /* We cannot ignore const expressions because it might be a reference
2869 to a const array but whose index contains side-effects. But we can
2870 ignore things that are actual constant or that already have been
2871 handled by this function. */
2873 if (TREE_CONSTANT (e) || code == SAVE_EXPR)
2876 switch (TREE_CODE_CLASS (code))
2886 /* If the expression has side-effects, then encase it in a SAVE_EXPR
2887 so that it will only be evaluated once. */
2888 /* The reference (r) and comparison (<) classes could be handled as
2889 below, but it is generally faster to only evaluate them once. */
2890 if (TREE_SIDE_EFFECTS (e))
2891 return save_expr (e);
2895 /* Constants need no processing. In fact, we should never reach
2900 /* Division is slow and tends to be compiled with jumps,
2901 especially the division by powers of 2 that is often
2902 found inside of an array reference. So do it just once. */
2903 if (code == TRUNC_DIV_EXPR || code == TRUNC_MOD_EXPR
2904 || code == FLOOR_DIV_EXPR || code == FLOOR_MOD_EXPR
2905 || code == CEIL_DIV_EXPR || code == CEIL_MOD_EXPR
2906 || code == ROUND_DIV_EXPR || code == ROUND_MOD_EXPR)
2907 return save_expr (e);
2908 /* Recursively stabilize each operand. */
2909 result = build_nt (code, stabilize_reference_1 (TREE_OPERAND (e, 0)),
2910 stabilize_reference_1 (TREE_OPERAND (e, 1)));
2914 /* Recursively stabilize each operand. */
2915 result = build_nt (code, stabilize_reference_1 (TREE_OPERAND (e, 0)));
2922 TREE_TYPE (result) = TREE_TYPE (e);
2923 TREE_READONLY (result) = TREE_READONLY (e);
2924 TREE_SIDE_EFFECTS (result) = TREE_SIDE_EFFECTS (e);
2925 TREE_THIS_VOLATILE (result) = TREE_THIS_VOLATILE (e);
2926 TREE_RAISES (result) = TREE_RAISES (e);
2931 /* Low-level constructors for expressions. */
2933 /* Build an expression of code CODE, data type TYPE,
2934 and operands as specified by the arguments ARG1 and following arguments.
2935 Expressions and reference nodes can be created this way.
2936 Constants, decls, types and misc nodes cannot be. */
2939 build VPROTO((enum tree_code code, tree tt, ...))
2941 #ifndef ANSI_PROTOTYPES
2942 enum tree_code code;
2947 register int length;
2952 #ifndef ANSI_PROTOTYPES
2953 code = va_arg (p, enum tree_code);
2954 tt = va_arg (p, tree);
2957 t = make_node (code);
2958 length = tree_code_length[(int) code];
2963 /* This is equivalent to the loop below, but faster. */
2964 register tree arg0 = va_arg (p, tree);
2965 register tree arg1 = va_arg (p, tree);
2966 TREE_OPERAND (t, 0) = arg0;
2967 TREE_OPERAND (t, 1) = arg1;
2968 if ((arg0 && TREE_SIDE_EFFECTS (arg0))
2969 || (arg1 && TREE_SIDE_EFFECTS (arg1)))
2970 TREE_SIDE_EFFECTS (t) = 1;
2972 = (arg0 && TREE_RAISES (arg0)) || (arg1 && TREE_RAISES (arg1));
2974 else if (length == 1)
2976 register tree arg0 = va_arg (p, tree);
2978 /* Call build1 for this! */
2979 if (TREE_CODE_CLASS (code) != 's')
2981 TREE_OPERAND (t, 0) = arg0;
2982 if (arg0 && TREE_SIDE_EFFECTS (arg0))
2983 TREE_SIDE_EFFECTS (t) = 1;
2984 TREE_RAISES (t) = (arg0 && TREE_RAISES (arg0));
2988 for (i = 0; i < length; i++)
2990 register tree operand = va_arg (p, tree);
2991 TREE_OPERAND (t, i) = operand;
2994 if (TREE_SIDE_EFFECTS (operand))
2995 TREE_SIDE_EFFECTS (t) = 1;
2996 if (TREE_RAISES (operand))
2997 TREE_RAISES (t) = 1;
3005 /* Same as above, but only builds for unary operators.
3006 Saves lions share of calls to `build'; cuts down use
3007 of varargs, which is expensive for RISC machines. */
3010 build1 (code, type, node)
3011 enum tree_code code;
3015 register struct obstack *obstack = expression_obstack;
3016 register int length;
3017 #ifdef GATHER_STATISTICS
3018 register tree_node_kind kind;
3022 #ifdef GATHER_STATISTICS
3023 if (TREE_CODE_CLASS (code) == 'r')
3029 length = sizeof (struct tree_exp);
3031 t = (tree) obstack_alloc (obstack, length);
3032 bzero ((PTR) t, length);
3034 #ifdef GATHER_STATISTICS
3035 tree_node_counts[(int)kind]++;
3036 tree_node_sizes[(int)kind] += length;
3039 TREE_TYPE (t) = type;
3040 TREE_SET_CODE (t, code);
3042 if (obstack == &permanent_obstack)
3043 TREE_PERMANENT (t) = 1;
3045 TREE_OPERAND (t, 0) = node;
3048 if (TREE_SIDE_EFFECTS (node))
3049 TREE_SIDE_EFFECTS (t) = 1;
3050 if (TREE_RAISES (node))
3051 TREE_RAISES (t) = 1;
3057 /* Similar except don't specify the TREE_TYPE
3058 and leave the TREE_SIDE_EFFECTS as 0.
3059 It is permissible for arguments to be null,
3060 or even garbage if their values do not matter. */
3063 build_nt VPROTO((enum tree_code code, ...))
3065 #ifndef ANSI_PROTOTYPES
3066 enum tree_code code;
3070 register int length;
3075 #ifndef ANSI_PROTOTYPES
3076 code = va_arg (p, enum tree_code);
3079 t = make_node (code);
3080 length = tree_code_length[(int) code];
3082 for (i = 0; i < length; i++)
3083 TREE_OPERAND (t, i) = va_arg (p, tree);
3089 /* Similar to `build_nt', except we build
3090 on the temp_decl_obstack, regardless. */
3093 build_parse_node VPROTO((enum tree_code code, ...))
3095 #ifndef ANSI_PROTOTYPES
3096 enum tree_code code;
3098 register struct obstack *ambient_obstack = expression_obstack;
3101 register int length;
3106 #ifndef ANSI_PROTOTYPES
3107 code = va_arg (p, enum tree_code);
3110 expression_obstack = &temp_decl_obstack;
3112 t = make_node (code);
3113 length = tree_code_length[(int) code];
3115 for (i = 0; i < length; i++)
3116 TREE_OPERAND (t, i) = va_arg (p, tree);
3119 expression_obstack = ambient_obstack;
3124 /* Commented out because this wants to be done very
3125 differently. See cp-lex.c. */
3127 build_op_identifier (op1, op2)
3130 register tree t = make_node (OP_IDENTIFIER);
3131 TREE_PURPOSE (t) = op1;
3132 TREE_VALUE (t) = op2;
3137 /* Create a DECL_... node of code CODE, name NAME and data type TYPE.
3138 We do NOT enter this node in any sort of symbol table.
3140 layout_decl is used to set up the decl's storage layout.
3141 Other slots are initialized to 0 or null pointers. */
3144 build_decl (code, name, type)
3145 enum tree_code code;
3150 t = make_node (code);
3152 /* if (type == error_mark_node)
3153 type = integer_type_node; */
3154 /* That is not done, deliberately, so that having error_mark_node
3155 as the type can suppress useless errors in the use of this variable. */
3157 DECL_NAME (t) = name;
3158 DECL_ASSEMBLER_NAME (t) = name;
3159 TREE_TYPE (t) = type;
3161 if (code == VAR_DECL || code == PARM_DECL || code == RESULT_DECL)
3163 else if (code == FUNCTION_DECL)
3164 DECL_MODE (t) = FUNCTION_MODE;
3169 /* BLOCK nodes are used to represent the structure of binding contours
3170 and declarations, once those contours have been exited and their contents
3171 compiled. This information is used for outputting debugging info. */
3174 build_block (vars, tags, subblocks, supercontext, chain)
3175 tree vars, tags, subblocks, supercontext, chain;
3177 register tree block = make_node (BLOCK);
3178 BLOCK_VARS (block) = vars;
3179 BLOCK_TYPE_TAGS (block) = tags;
3180 BLOCK_SUBBLOCKS (block) = subblocks;
3181 BLOCK_SUPERCONTEXT (block) = supercontext;
3182 BLOCK_CHAIN (block) = chain;
3186 /* EXPR_WITH_FILE_LOCATION are used to keep track of the exact
3187 location where an expression or an identifier were encountered. It
3188 is necessary for languages where the frontend parser will handle
3189 recursively more than one file (Java is one of them). */
3192 build_expr_wfl (node, file, line, col)
3197 static const char *last_file = 0;
3198 static tree last_filenode = NULL_TREE;
3199 register tree wfl = make_node (EXPR_WITH_FILE_LOCATION);
3201 EXPR_WFL_NODE (wfl) = node;
3202 EXPR_WFL_SET_LINECOL (wfl, line, col);
3203 if (file != last_file)
3206 last_filenode = file ? get_identifier (file) : NULL_TREE;
3208 EXPR_WFL_FILENAME_NODE (wfl) = last_filenode;
3211 TREE_SIDE_EFFECTS (wfl) = TREE_SIDE_EFFECTS (node);
3212 TREE_TYPE (wfl) = TREE_TYPE (node);
3217 /* Return a declaration like DDECL except that its DECL_MACHINE_ATTRIBUTE
3221 build_decl_attribute_variant (ddecl, attribute)
3222 tree ddecl, attribute;
3224 DECL_MACHINE_ATTRIBUTES (ddecl) = attribute;
3228 /* Return a type like TTYPE except that its TYPE_ATTRIBUTE
3231 Record such modified types already made so we don't make duplicates. */
3234 build_type_attribute_variant (ttype, attribute)
3235 tree ttype, attribute;
3237 if ( ! attribute_list_equal (TYPE_ATTRIBUTES (ttype), attribute))
3239 register int hashcode;
3240 register struct obstack *ambient_obstack = current_obstack;
3243 if (ambient_obstack != &permanent_obstack)
3244 current_obstack = TYPE_OBSTACK (ttype);
3246 ntype = copy_node (ttype);
3248 TYPE_POINTER_TO (ntype) = 0;
3249 TYPE_REFERENCE_TO (ntype) = 0;
3250 TYPE_ATTRIBUTES (ntype) = attribute;
3252 /* Create a new main variant of TYPE. */
3253 TYPE_MAIN_VARIANT (ntype) = ntype;
3254 TYPE_NEXT_VARIANT (ntype) = 0;
3255 set_type_quals (ntype, TYPE_UNQUALIFIED);
3257 hashcode = TYPE_HASH (TREE_CODE (ntype))
3258 + TYPE_HASH (TREE_TYPE (ntype))
3259 + attribute_hash_list (attribute);
3261 switch (TREE_CODE (ntype))
3264 hashcode += TYPE_HASH (TYPE_ARG_TYPES (ntype));
3267 hashcode += TYPE_HASH (TYPE_DOMAIN (ntype));
3270 hashcode += TYPE_HASH (TYPE_MAX_VALUE (ntype));
3273 hashcode += TYPE_HASH (TYPE_PRECISION (ntype));
3279 ntype = type_hash_canon (hashcode, ntype);
3280 ttype = build_qualified_type (ntype, TYPE_QUALS (ttype));
3282 /* We must restore the current obstack after the type_hash_canon call,
3283 because type_hash_canon calls type_hash_add for permanent types, and
3284 then type_hash_add calls oballoc expecting to get something permanent
3286 current_obstack = ambient_obstack;
3292 /* Return a 1 if ATTR_NAME and ATTR_ARGS is valid for either declaration DECL
3293 or type TYPE and 0 otherwise. Validity is determined the configuration
3294 macros VALID_MACHINE_DECL_ATTRIBUTE and VALID_MACHINE_TYPE_ATTRIBUTE. */
3297 valid_machine_attribute (attr_name, attr_args, decl, type)
3299 tree attr_args ATTRIBUTE_UNUSED;
3300 tree decl ATTRIBUTE_UNUSED;
3301 tree type ATTRIBUTE_UNUSED;
3304 #ifdef VALID_MACHINE_DECL_ATTRIBUTE
3305 tree decl_attr_list = decl != 0 ? DECL_MACHINE_ATTRIBUTES (decl) : 0;
3307 #ifdef VALID_MACHINE_TYPE_ATTRIBUTE
3308 tree type_attr_list = TYPE_ATTRIBUTES (type);
3311 if (TREE_CODE (attr_name) != IDENTIFIER_NODE)
3314 #ifdef VALID_MACHINE_DECL_ATTRIBUTE
3316 && VALID_MACHINE_DECL_ATTRIBUTE (decl, decl_attr_list, attr_name, attr_args))
3318 tree attr = lookup_attribute (IDENTIFIER_POINTER (attr_name),
3321 if (attr != NULL_TREE)
3323 /* Override existing arguments. Declarations are unique so we can
3324 modify this in place. */
3325 TREE_VALUE (attr) = attr_args;
3329 decl_attr_list = tree_cons (attr_name, attr_args, decl_attr_list);
3330 decl = build_decl_attribute_variant (decl, decl_attr_list);
3337 #ifdef VALID_MACHINE_TYPE_ATTRIBUTE
3339 /* Don't apply the attribute to both the decl and the type. */;
3340 else if (VALID_MACHINE_TYPE_ATTRIBUTE (type, type_attr_list, attr_name,
3343 tree attr = lookup_attribute (IDENTIFIER_POINTER (attr_name),
3346 if (attr != NULL_TREE)
3348 /* Override existing arguments.
3349 ??? This currently works since attribute arguments are not
3350 included in `attribute_hash_list'. Something more complicated
3351 may be needed in the future. */
3352 TREE_VALUE (attr) = attr_args;
3356 /* If this is part of a declaration, create a type variant,
3357 otherwise, this is part of a type definition, so add it
3358 to the base type. */
3359 type_attr_list = tree_cons (attr_name, attr_args, type_attr_list);
3361 type = build_type_attribute_variant (type, type_attr_list);
3363 TYPE_ATTRIBUTES (type) = type_attr_list;
3366 TREE_TYPE (decl) = type;
3370 /* Handle putting a type attribute on pointer-to-function-type by putting
3371 the attribute on the function type. */
3372 else if (POINTER_TYPE_P (type)
3373 && TREE_CODE (TREE_TYPE (type)) == FUNCTION_TYPE
3374 && VALID_MACHINE_TYPE_ATTRIBUTE (TREE_TYPE (type), type_attr_list,
3375 attr_name, attr_args))
3377 tree inner_type = TREE_TYPE (type);
3378 tree inner_attr_list = TYPE_ATTRIBUTES (inner_type);
3379 tree attr = lookup_attribute (IDENTIFIER_POINTER (attr_name),
3382 if (attr != NULL_TREE)
3383 TREE_VALUE (attr) = attr_args;
3386 inner_attr_list = tree_cons (attr_name, attr_args, inner_attr_list);
3387 inner_type = build_type_attribute_variant (inner_type,
3392 TREE_TYPE (decl) = build_pointer_type (inner_type);
3395 /* Clear TYPE_POINTER_TO for the old inner type, since
3396 `type' won't be pointing to it anymore. */
3397 TYPE_POINTER_TO (TREE_TYPE (type)) = NULL_TREE;
3398 TREE_TYPE (type) = inner_type;
3408 /* Return non-zero if IDENT is a valid name for attribute ATTR,
3411 We try both `text' and `__text__', ATTR may be either one. */
3412 /* ??? It might be a reasonable simplification to require ATTR to be only
3413 `text'. One might then also require attribute lists to be stored in
3414 their canonicalized form. */
3417 is_attribute_p (attr, ident)
3421 int ident_len, attr_len;
3424 if (TREE_CODE (ident) != IDENTIFIER_NODE)
3427 if (strcmp (attr, IDENTIFIER_POINTER (ident)) == 0)
3430 p = IDENTIFIER_POINTER (ident);
3431 ident_len = strlen (p);
3432 attr_len = strlen (attr);
3434 /* If ATTR is `__text__', IDENT must be `text'; and vice versa. */
3438 || attr[attr_len - 2] != '_'
3439 || attr[attr_len - 1] != '_')
3441 if (ident_len == attr_len - 4
3442 && strncmp (attr + 2, p, attr_len - 4) == 0)
3447 if (ident_len == attr_len + 4
3448 && p[0] == '_' && p[1] == '_'
3449 && p[ident_len - 2] == '_' && p[ident_len - 1] == '_'
3450 && strncmp (attr, p + 2, attr_len) == 0)
3457 /* Given an attribute name and a list of attributes, return a pointer to the
3458 attribute's list element if the attribute is part of the list, or NULL_TREE
3462 lookup_attribute (attr_name, list)
3463 const char *attr_name;
3468 for (l = list; l; l = TREE_CHAIN (l))
3470 if (TREE_CODE (TREE_PURPOSE (l)) != IDENTIFIER_NODE)
3472 if (is_attribute_p (attr_name, TREE_PURPOSE (l)))
3479 /* Return an attribute list that is the union of a1 and a2. */
3482 merge_attributes (a1, a2)
3483 register tree a1, a2;
3487 /* Either one unset? Take the set one. */
3489 if (! (attributes = a1))
3492 /* One that completely contains the other? Take it. */
3494 else if (a2 && ! attribute_list_contained (a1, a2))
3496 if (attribute_list_contained (a2, a1))
3500 /* Pick the longest list, and hang on the other list. */
3501 /* ??? For the moment we punt on the issue of attrs with args. */
3503 if (list_length (a1) < list_length (a2))
3504 attributes = a2, a2 = a1;
3506 for (; a2; a2 = TREE_CHAIN (a2))
3507 if (lookup_attribute (IDENTIFIER_POINTER (TREE_PURPOSE (a2)),
3508 attributes) == NULL_TREE)
3510 a1 = copy_node (a2);
3511 TREE_CHAIN (a1) = attributes;
3519 /* Given types T1 and T2, merge their attributes and return
3523 merge_machine_type_attributes (t1, t2)
3526 #ifdef MERGE_MACHINE_TYPE_ATTRIBUTES
3527 return MERGE_MACHINE_TYPE_ATTRIBUTES (t1, t2);
3529 return merge_attributes (TYPE_ATTRIBUTES (t1),
3530 TYPE_ATTRIBUTES (t2));
3534 /* Given decls OLDDECL and NEWDECL, merge their attributes and return
3538 merge_machine_decl_attributes (olddecl, newdecl)
3539 tree olddecl, newdecl;
3541 #ifdef MERGE_MACHINE_DECL_ATTRIBUTES
3542 return MERGE_MACHINE_DECL_ATTRIBUTES (olddecl, newdecl);
3544 return merge_attributes (DECL_MACHINE_ATTRIBUTES (olddecl),
3545 DECL_MACHINE_ATTRIBUTES (newdecl));
3549 /* Set the type qualifiers for TYPE to TYPE_QUALS, which is a bitmask
3550 of the various TYPE_QUAL values. */
3553 set_type_quals (type, type_quals)
3557 TYPE_READONLY (type) = (type_quals & TYPE_QUAL_CONST) != 0;
3558 TYPE_VOLATILE (type) = (type_quals & TYPE_QUAL_VOLATILE) != 0;
3559 TYPE_RESTRICT (type) = (type_quals & TYPE_QUAL_RESTRICT) != 0;
3562 /* Given a type node TYPE and a TYPE_QUALIFIER_SET, return a type for
3563 the same kind of data as TYPE describes. Variants point to the
3564 "main variant" (which has no qualifiers set) via TYPE_MAIN_VARIANT,
3565 and it points to a chain of other variants so that duplicate
3566 variants are never made. Only main variants should ever appear as
3567 types of expressions. */
3570 build_qualified_type (type, type_quals)
3576 /* Search the chain of variants to see if there is already one there just
3577 like the one we need to have. If so, use that existing one. We must
3578 preserve the TYPE_NAME, since there is code that depends on this. */
3580 for (t = TYPE_MAIN_VARIANT (type); t; t = TYPE_NEXT_VARIANT (t))
3581 if (TYPE_QUALS (t) == type_quals && TYPE_NAME (t) == TYPE_NAME (type))
3584 /* We need a new one. */
3585 t = build_type_copy (type);
3586 set_type_quals (t, type_quals);
3590 /* Create a new variant of TYPE, equivalent but distinct.
3591 This is so the caller can modify it. */
3594 build_type_copy (type)
3597 register tree t, m = TYPE_MAIN_VARIANT (type);
3598 register struct obstack *ambient_obstack = current_obstack;
3600 current_obstack = TYPE_OBSTACK (type);
3601 t = copy_node (type);
3602 current_obstack = ambient_obstack;
3604 TYPE_POINTER_TO (t) = 0;
3605 TYPE_REFERENCE_TO (t) = 0;
3607 /* Add this type to the chain of variants of TYPE. */
3608 TYPE_NEXT_VARIANT (t) = TYPE_NEXT_VARIANT (m);
3609 TYPE_NEXT_VARIANT (m) = t;
3614 /* Hashing of types so that we don't make duplicates.
3615 The entry point is `type_hash_canon'. */
3617 /* Compute a hash code for a list of types (chain of TREE_LIST nodes
3618 with types in the TREE_VALUE slots), by adding the hash codes
3619 of the individual types. */
3622 type_hash_list (list)
3625 register int hashcode;
3627 for (hashcode = 0, tail = list; tail; tail = TREE_CHAIN (tail))
3628 hashcode += TYPE_HASH (TREE_VALUE (tail));
3632 /* Look in the type hash table for a type isomorphic to TYPE.
3633 If one is found, return it. Otherwise return 0. */
3636 type_hash_lookup (hashcode, type)
3640 register struct type_hash *h;
3641 for (h = type_hash_table[hashcode % TYPE_HASH_SIZE]; h; h = h->next)
3642 if (h->hashcode == hashcode
3643 && TREE_CODE (h->type) == TREE_CODE (type)
3644 && TREE_TYPE (h->type) == TREE_TYPE (type)
3645 && attribute_list_equal (TYPE_ATTRIBUTES (h->type),
3646 TYPE_ATTRIBUTES (type))
3647 && (TYPE_MAX_VALUE (h->type) == TYPE_MAX_VALUE (type)
3648 || tree_int_cst_equal (TYPE_MAX_VALUE (h->type),
3649 TYPE_MAX_VALUE (type)))
3650 && (TYPE_MIN_VALUE (h->type) == TYPE_MIN_VALUE (type)
3651 || tree_int_cst_equal (TYPE_MIN_VALUE (h->type),
3652 TYPE_MIN_VALUE (type)))
3653 /* Note that TYPE_DOMAIN is TYPE_ARG_TYPES for FUNCTION_TYPE. */
3654 && (TYPE_DOMAIN (h->type) == TYPE_DOMAIN (type)
3655 || (TYPE_DOMAIN (h->type)
3656 && TREE_CODE (TYPE_DOMAIN (h->type)) == TREE_LIST
3657 && TYPE_DOMAIN (type)
3658 && TREE_CODE (TYPE_DOMAIN (type)) == TREE_LIST
3659 && type_list_equal (TYPE_DOMAIN (h->type),
3660 TYPE_DOMAIN (type)))))
3665 /* Add an entry to the type-hash-table
3666 for a type TYPE whose hash code is HASHCODE. */
3669 type_hash_add (hashcode, type)
3673 register struct type_hash *h;
3675 h = (struct type_hash *) permalloc (sizeof (struct type_hash));
3676 h->hashcode = hashcode;
3678 h->next = type_hash_table[hashcode % TYPE_HASH_SIZE];
3679 type_hash_table[hashcode % TYPE_HASH_SIZE] = h;
3682 /* Given TYPE, and HASHCODE its hash code, return the canonical
3683 object for an identical type if one already exists.
3684 Otherwise, return TYPE, and record it as the canonical object
3685 if it is a permanent object.
3687 To use this function, first create a type of the sort you want.
3688 Then compute its hash code from the fields of the type that
3689 make it different from other similar types.
3690 Then call this function and use the value.
3691 This function frees the type you pass in if it is a duplicate. */
3693 /* Set to 1 to debug without canonicalization. Never set by program. */
3694 int debug_no_type_hash = 0;
3697 type_hash_canon (hashcode, type)
3703 if (debug_no_type_hash)
3706 t1 = type_hash_lookup (hashcode, type);
3709 obstack_free (TYPE_OBSTACK (type), type);
3710 #ifdef GATHER_STATISTICS
3711 tree_node_counts[(int)t_kind]--;
3712 tree_node_sizes[(int)t_kind] -= sizeof (struct tree_type);
3717 /* If this is a permanent type, record it for later reuse. */
3718 if (TREE_PERMANENT (type))
3719 type_hash_add (hashcode, type);
3724 /* Mark ARG (which is really a struct type_hash **) for GC. */
3727 mark_type_hash (arg)
3730 struct type_hash *t = *(struct type_hash **) arg;
3734 ggc_mark_tree (t->type);
3739 /* Compute a hash code for a list of attributes (chain of TREE_LIST nodes
3740 with names in the TREE_PURPOSE slots and args in the TREE_VALUE slots),
3741 by adding the hash codes of the individual attributes. */
3744 attribute_hash_list (list)
3747 register int hashcode;
3749 for (hashcode = 0, tail = list; tail; tail = TREE_CHAIN (tail))
3750 /* ??? Do we want to add in TREE_VALUE too? */
3751 hashcode += TYPE_HASH (TREE_PURPOSE (tail));
3755 /* Given two lists of attributes, return true if list l2 is
3756 equivalent to l1. */
3759 attribute_list_equal (l1, l2)
3762 return attribute_list_contained (l1, l2)
3763 && attribute_list_contained (l2, l1);
3766 /* Given two lists of attributes, return true if list L2 is
3767 completely contained within L1. */
3768 /* ??? This would be faster if attribute names were stored in a canonicalized
3769 form. Otherwise, if L1 uses `foo' and L2 uses `__foo__', the long method
3770 must be used to show these elements are equivalent (which they are). */
3771 /* ??? It's not clear that attributes with arguments will always be handled
3775 attribute_list_contained (l1, l2)
3778 register tree t1, t2;
3780 /* First check the obvious, maybe the lists are identical. */
3784 /* Maybe the lists are similar. */
3785 for (t1 = l1, t2 = l2;
3787 && TREE_PURPOSE (t1) == TREE_PURPOSE (t2)
3788 && TREE_VALUE (t1) == TREE_VALUE (t2);
3789 t1 = TREE_CHAIN (t1), t2 = TREE_CHAIN (t2));
3791 /* Maybe the lists are equal. */
3792 if (t1 == 0 && t2 == 0)
3795 for (; t2; t2 = TREE_CHAIN (t2))
3798 = lookup_attribute (IDENTIFIER_POINTER (TREE_PURPOSE (t2)), l1);
3800 if (attr == NULL_TREE)
3802 if (simple_cst_equal (TREE_VALUE (t2), TREE_VALUE (attr)) != 1)
3809 /* Given two lists of types
3810 (chains of TREE_LIST nodes with types in the TREE_VALUE slots)
3811 return 1 if the lists contain the same types in the same order.
3812 Also, the TREE_PURPOSEs must match. */
3815 type_list_equal (l1, l2)
3818 register tree t1, t2;
3820 for (t1 = l1, t2 = l2; t1 && t2; t1 = TREE_CHAIN (t1), t2 = TREE_CHAIN (t2))
3821 if (TREE_VALUE (t1) != TREE_VALUE (t2)
3822 || (TREE_PURPOSE (t1) != TREE_PURPOSE (t2)
3823 && ! (1 == simple_cst_equal (TREE_PURPOSE (t1), TREE_PURPOSE (t2))
3824 && (TREE_TYPE (TREE_PURPOSE (t1))
3825 == TREE_TYPE (TREE_PURPOSE (t2))))))
3831 /* Nonzero if integer constants T1 and T2
3832 represent the same constant value. */
3835 tree_int_cst_equal (t1, t2)
3840 if (t1 == 0 || t2 == 0)
3842 if (TREE_CODE (t1) == INTEGER_CST
3843 && TREE_CODE (t2) == INTEGER_CST
3844 && TREE_INT_CST_LOW (t1) == TREE_INT_CST_LOW (t2)
3845 && TREE_INT_CST_HIGH (t1) == TREE_INT_CST_HIGH (t2))
3850 /* Nonzero if integer constants T1 and T2 represent values that satisfy <.
3851 The precise way of comparison depends on their data type. */
3854 tree_int_cst_lt (t1, t2)
3860 if (!TREE_UNSIGNED (TREE_TYPE (t1)))
3861 return INT_CST_LT (t1, t2);
3862 return INT_CST_LT_UNSIGNED (t1, t2);
3865 /* Return an indication of the sign of the integer constant T.
3866 The return value is -1 if T < 0, 0 if T == 0, and 1 if T > 0.
3867 Note that -1 will never be returned it T's type is unsigned. */
3870 tree_int_cst_sgn (t)
3873 if (TREE_INT_CST_LOW (t) == 0 && TREE_INT_CST_HIGH (t) == 0)
3875 else if (TREE_UNSIGNED (TREE_TYPE (t)))
3877 else if (TREE_INT_CST_HIGH (t) < 0)
3883 /* Compare two constructor-element-type constants. Return 1 if the lists
3884 are known to be equal; otherwise return 0. */
3887 simple_cst_list_equal (l1, l2)
3890 while (l1 != NULL_TREE && l2 != NULL_TREE)
3892 if (simple_cst_equal (TREE_VALUE (l1), TREE_VALUE (l2)) != 1)
3895 l1 = TREE_CHAIN (l1);
3896 l2 = TREE_CHAIN (l2);
3902 /* Return truthvalue of whether T1 is the same tree structure as T2.
3903 Return 1 if they are the same.
3904 Return 0 if they are understandably different.
3905 Return -1 if either contains tree structure not understood by
3909 simple_cst_equal (t1, t2)
3912 register enum tree_code code1, code2;
3917 if (t1 == 0 || t2 == 0)
3920 code1 = TREE_CODE (t1);
3921 code2 = TREE_CODE (t2);
3923 if (code1 == NOP_EXPR || code1 == CONVERT_EXPR || code1 == NON_LVALUE_EXPR)
3925 if (code2 == NOP_EXPR || code2 == CONVERT_EXPR
3926 || code2 == NON_LVALUE_EXPR)
3927 return simple_cst_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
3929 return simple_cst_equal (TREE_OPERAND (t1, 0), t2);
3931 else if (code2 == NOP_EXPR || code2 == CONVERT_EXPR
3932 || code2 == NON_LVALUE_EXPR)
3933 return simple_cst_equal (t1, TREE_OPERAND (t2, 0));
3941 return TREE_INT_CST_LOW (t1) == TREE_INT_CST_LOW (t2)
3942 && TREE_INT_CST_HIGH (t1) == TREE_INT_CST_HIGH (t2);
3945 return REAL_VALUES_IDENTICAL (TREE_REAL_CST (t1), TREE_REAL_CST (t2));
3948 return TREE_STRING_LENGTH (t1) == TREE_STRING_LENGTH (t2)
3949 && !bcmp (TREE_STRING_POINTER (t1), TREE_STRING_POINTER (t2),
3950 TREE_STRING_LENGTH (t1));
3953 if (CONSTRUCTOR_ELTS (t1) == CONSTRUCTOR_ELTS (t2))
3959 return simple_cst_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
3962 cmp = simple_cst_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
3965 return simple_cst_list_equal (TREE_OPERAND (t1, 1), TREE_OPERAND (t2, 1));
3968 /* Special case: if either target is an unallocated VAR_DECL,
3969 it means that it's going to be unified with whatever the
3970 TARGET_EXPR is really supposed to initialize, so treat it
3971 as being equivalent to anything. */
3972 if ((TREE_CODE (TREE_OPERAND (t1, 0)) == VAR_DECL
3973 && DECL_NAME (TREE_OPERAND (t1, 0)) == NULL_TREE
3974 && DECL_RTL (TREE_OPERAND (t1, 0)) == 0)
3975 || (TREE_CODE (TREE_OPERAND (t2, 0)) == VAR_DECL
3976 && DECL_NAME (TREE_OPERAND (t2, 0)) == NULL_TREE
3977 && DECL_RTL (TREE_OPERAND (t2, 0)) == 0))
3980 cmp = simple_cst_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
3983 return simple_cst_equal (TREE_OPERAND (t1, 1), TREE_OPERAND (t2, 1));
3985 case WITH_CLEANUP_EXPR:
3986 cmp = simple_cst_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
3989 return simple_cst_equal (TREE_OPERAND (t1, 2), TREE_OPERAND (t1, 2));
3992 if (TREE_OPERAND (t1, 1) == TREE_OPERAND (t2, 1))
3993 return simple_cst_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
4006 /* This general rule works for most tree codes. All exceptions should be
4007 handled above. If this is a language-specific tree code, we can't
4008 trust what might be in the operand, so say we don't know
4010 if ((int) code1 >= (int) LAST_AND_UNUSED_TREE_CODE)
4013 switch (TREE_CODE_CLASS (code1))
4023 for (i=0; i<tree_code_length[(int) code1]; ++i)
4025 cmp = simple_cst_equal (TREE_OPERAND (t1, i), TREE_OPERAND (t2, i));
4036 /* Constructors for pointer, array and function types.
4037 (RECORD_TYPE, UNION_TYPE and ENUMERAL_TYPE nodes are
4038 constructed by language-dependent code, not here.) */
4040 /* Construct, lay out and return the type of pointers to TO_TYPE.
4041 If such a type has already been constructed, reuse it. */
4044 build_pointer_type (to_type)
4047 register tree t = TYPE_POINTER_TO (to_type);
4049 /* First, if we already have a type for pointers to TO_TYPE, use it. */
4054 /* We need a new one. Put this in the same obstack as TO_TYPE. */
4055 push_obstacks (TYPE_OBSTACK (to_type), TYPE_OBSTACK (to_type));
4056 t = make_node (POINTER_TYPE);
4059 TREE_TYPE (t) = to_type;
4061 /* Record this type as the pointer to TO_TYPE. */
4062 TYPE_POINTER_TO (to_type) = t;
4064 /* Lay out the type. This function has many callers that are concerned
4065 with expression-construction, and this simplifies them all.
4066 Also, it guarantees the TYPE_SIZE is in the same obstack as the type. */
4072 /* Create a type of integers to be the TYPE_DOMAIN of an ARRAY_TYPE.
4073 MAXVAL should be the maximum value in the domain
4074 (one less than the length of the array).
4076 The maximum value that MAXVAL can have is INT_MAX for a HOST_WIDE_INT.
4077 We don't enforce this limit, that is up to caller (e.g. language front end).
4078 The limit exists because the result is a signed type and we don't handle
4079 sizes that use more than one HOST_WIDE_INT. */
4082 build_index_type (maxval)
4085 register tree itype = make_node (INTEGER_TYPE);
4087 TYPE_PRECISION (itype) = TYPE_PRECISION (sizetype);
4088 TYPE_MIN_VALUE (itype) = size_zero_node;
4090 push_obstacks (TYPE_OBSTACK (itype), TYPE_OBSTACK (itype));
4091 TYPE_MAX_VALUE (itype) = convert (sizetype, maxval);
4094 TYPE_MODE (itype) = TYPE_MODE (sizetype);
4095 TYPE_SIZE (itype) = TYPE_SIZE (sizetype);
4096 TYPE_SIZE_UNIT (itype) = TYPE_SIZE_UNIT (sizetype);
4097 TYPE_ALIGN (itype) = TYPE_ALIGN (sizetype);
4098 if (TREE_CODE (maxval) == INTEGER_CST)
4100 int maxint = (int) TREE_INT_CST_LOW (maxval);
4101 /* If the domain should be empty, make sure the maxval
4102 remains -1 and is not spoiled by truncation. */
4103 if (INT_CST_LT (maxval, integer_zero_node))
4105 TYPE_MAX_VALUE (itype) = build_int_2 (-1, -1);
4106 TREE_TYPE (TYPE_MAX_VALUE (itype)) = sizetype;
4108 return type_hash_canon (maxint < 0 ? ~maxint : maxint, itype);
4114 /* Create a range of some discrete type TYPE (an INTEGER_TYPE,
4115 ENUMERAL_TYPE, BOOLEAN_TYPE, or CHAR_TYPE), with
4116 low bound LOWVAL and high bound HIGHVAL.
4117 if TYPE==NULL_TREE, sizetype is used. */
4120 build_range_type (type, lowval, highval)
4121 tree type, lowval, highval;
4123 register tree itype = make_node (INTEGER_TYPE);
4125 TREE_TYPE (itype) = type;
4126 if (type == NULL_TREE)
4129 push_obstacks (TYPE_OBSTACK (itype), TYPE_OBSTACK (itype));
4130 TYPE_MIN_VALUE (itype) = convert (type, lowval);
4131 TYPE_MAX_VALUE (itype) = highval ? convert (type, highval) : NULL;
4134 TYPE_PRECISION (itype) = TYPE_PRECISION (type);
4135 TYPE_MODE (itype) = TYPE_MODE (type);
4136 TYPE_SIZE (itype) = TYPE_SIZE (type);
4137 TYPE_SIZE_UNIT (itype) = TYPE_SIZE_UNIT (type);
4138 TYPE_ALIGN (itype) = TYPE_ALIGN (type);
4139 if (TREE_CODE (lowval) == INTEGER_CST)
4141 HOST_WIDE_INT lowint, highint;
4144 lowint = TREE_INT_CST_LOW (lowval);
4145 if (highval && TREE_CODE (highval) == INTEGER_CST)
4146 highint = TREE_INT_CST_LOW (highval);
4148 highint = (~(unsigned HOST_WIDE_INT)0) >> 1;
4150 maxint = (int) (highint - lowint);
4151 return type_hash_canon (maxint < 0 ? ~maxint : maxint, itype);
4157 /* Just like build_index_type, but takes lowval and highval instead
4158 of just highval (maxval). */
4161 build_index_2_type (lowval,highval)
4162 tree lowval, highval;
4164 return build_range_type (NULL_TREE, lowval, highval);
4167 /* Return nonzero iff ITYPE1 and ITYPE2 are equal (in the LISP sense).
4168 Needed because when index types are not hashed, equal index types
4169 built at different times appear distinct, even though structurally,
4173 index_type_equal (itype1, itype2)
4174 tree itype1, itype2;
4176 if (TREE_CODE (itype1) != TREE_CODE (itype2))
4178 if (TREE_CODE (itype1) == INTEGER_TYPE)
4180 if (TYPE_PRECISION (itype1) != TYPE_PRECISION (itype2)
4181 || TYPE_MODE (itype1) != TYPE_MODE (itype2)
4182 || simple_cst_equal (TYPE_SIZE (itype1), TYPE_SIZE (itype2)) != 1
4183 || TYPE_ALIGN (itype1) != TYPE_ALIGN (itype2))
4185 if (1 == simple_cst_equal (TYPE_MIN_VALUE (itype1),
4186 TYPE_MIN_VALUE (itype2))
4187 && 1 == simple_cst_equal (TYPE_MAX_VALUE (itype1),
4188 TYPE_MAX_VALUE (itype2)))
4195 /* Construct, lay out and return the type of arrays of elements with ELT_TYPE
4196 and number of elements specified by the range of values of INDEX_TYPE.
4197 If such a type has already been constructed, reuse it. */
4200 build_array_type (elt_type, index_type)
4201 tree elt_type, index_type;
4206 if (TREE_CODE (elt_type) == FUNCTION_TYPE)
4208 error ("arrays of functions are not meaningful");
4209 elt_type = integer_type_node;
4212 /* Make sure TYPE_POINTER_TO (elt_type) is filled in. */
4213 build_pointer_type (elt_type);
4215 /* Allocate the array after the pointer type,
4216 in case we free it in type_hash_canon. */
4217 t = make_node (ARRAY_TYPE);
4218 TREE_TYPE (t) = elt_type;
4219 TYPE_DOMAIN (t) = index_type;
4221 if (index_type == 0)
4226 hashcode = TYPE_HASH (elt_type) + TYPE_HASH (index_type);
4227 t = type_hash_canon (hashcode, t);
4229 if (TYPE_SIZE (t) == 0)
4234 /* Return the TYPE of the elements comprising
4235 the innermost dimension of ARRAY. */
4238 get_inner_array_type (array)
4241 tree type = TREE_TYPE (array);
4243 while (TREE_CODE (type) == ARRAY_TYPE)
4244 type = TREE_TYPE (type);
4249 /* Construct, lay out and return
4250 the type of functions returning type VALUE_TYPE
4251 given arguments of types ARG_TYPES.
4252 ARG_TYPES is a chain of TREE_LIST nodes whose TREE_VALUEs
4253 are data type nodes for the arguments of the function.
4254 If such a type has already been constructed, reuse it. */
4257 build_function_type (value_type, arg_types)
4258 tree value_type, arg_types;
4263 if (TREE_CODE (value_type) == FUNCTION_TYPE)
4265 error ("function return type cannot be function");
4266 value_type = integer_type_node;
4269 /* Make a node of the sort we want. */
4270 t = make_node (FUNCTION_TYPE);
4271 TREE_TYPE (t) = value_type;
4272 TYPE_ARG_TYPES (t) = arg_types;
4274 /* If we already have such a type, use the old one and free this one. */
4275 hashcode = TYPE_HASH (value_type) + type_hash_list (arg_types);
4276 t = type_hash_canon (hashcode, t);
4278 if (TYPE_SIZE (t) == 0)
4283 /* Build the node for the type of references-to-TO_TYPE. */
4286 build_reference_type (to_type)
4289 register tree t = TYPE_REFERENCE_TO (to_type);
4291 /* First, if we already have a type for pointers to TO_TYPE, use it. */
4296 /* We need a new one. Put this in the same obstack as TO_TYPE. */
4297 push_obstacks (TYPE_OBSTACK (to_type), TYPE_OBSTACK (to_type));
4298 t = make_node (REFERENCE_TYPE);
4301 TREE_TYPE (t) = to_type;
4303 /* Record this type as the pointer to TO_TYPE. */
4304 TYPE_REFERENCE_TO (to_type) = t;
4311 /* Construct, lay out and return the type of methods belonging to class
4312 BASETYPE and whose arguments and values are described by TYPE.
4313 If that type exists already, reuse it.
4314 TYPE must be a FUNCTION_TYPE node. */
4317 build_method_type (basetype, type)
4318 tree basetype, type;
4323 /* Make a node of the sort we want. */
4324 t = make_node (METHOD_TYPE);
4326 if (TREE_CODE (type) != FUNCTION_TYPE)
4329 TYPE_METHOD_BASETYPE (t) = TYPE_MAIN_VARIANT (basetype);
4330 TREE_TYPE (t) = TREE_TYPE (type);
4332 /* The actual arglist for this function includes a "hidden" argument
4333 which is "this". Put it into the list of argument types. */
4336 = tree_cons (NULL_TREE,
4337 build_pointer_type (basetype), TYPE_ARG_TYPES (type));
4339 /* If we already have such a type, use the old one and free this one. */
4340 hashcode = TYPE_HASH (basetype) + TYPE_HASH (type);
4341 t = type_hash_canon (hashcode, t);
4343 if (TYPE_SIZE (t) == 0)
4349 /* Construct, lay out and return the type of offsets to a value
4350 of type TYPE, within an object of type BASETYPE.
4351 If a suitable offset type exists already, reuse it. */
4354 build_offset_type (basetype, type)
4355 tree basetype, type;
4360 /* Make a node of the sort we want. */
4361 t = make_node (OFFSET_TYPE);
4363 TYPE_OFFSET_BASETYPE (t) = TYPE_MAIN_VARIANT (basetype);
4364 TREE_TYPE (t) = type;
4366 /* If we already have such a type, use the old one and free this one. */
4367 hashcode = TYPE_HASH (basetype) + TYPE_HASH (type);
4368 t = type_hash_canon (hashcode, t);
4370 if (TYPE_SIZE (t) == 0)
4376 /* Create a complex type whose components are COMPONENT_TYPE. */
4379 build_complex_type (component_type)
4380 tree component_type;
4385 /* Make a node of the sort we want. */
4386 t = make_node (COMPLEX_TYPE);
4388 TREE_TYPE (t) = TYPE_MAIN_VARIANT (component_type);
4389 set_type_quals (t, TYPE_QUALS (component_type));
4391 /* If we already have such a type, use the old one and free this one. */
4392 hashcode = TYPE_HASH (component_type);
4393 t = type_hash_canon (hashcode, t);
4395 if (TYPE_SIZE (t) == 0)
4401 /* Return OP, stripped of any conversions to wider types as much as is safe.
4402 Converting the value back to OP's type makes a value equivalent to OP.
4404 If FOR_TYPE is nonzero, we return a value which, if converted to
4405 type FOR_TYPE, would be equivalent to converting OP to type FOR_TYPE.
4407 If FOR_TYPE is nonzero, unaligned bit-field references may be changed to the
4408 narrowest type that can hold the value, even if they don't exactly fit.
4409 Otherwise, bit-field references are changed to a narrower type
4410 only if they can be fetched directly from memory in that type.
4412 OP must have integer, real or enumeral type. Pointers are not allowed!
4414 There are some cases where the obvious value we could return
4415 would regenerate to OP if converted to OP's type,
4416 but would not extend like OP to wider types.
4417 If FOR_TYPE indicates such extension is contemplated, we eschew such values.
4418 For example, if OP is (unsigned short)(signed char)-1,
4419 we avoid returning (signed char)-1 if FOR_TYPE is int,
4420 even though extending that to an unsigned short would regenerate OP,
4421 since the result of extending (signed char)-1 to (int)
4422 is different from (int) OP. */
4425 get_unwidened (op, for_type)
4429 /* Set UNS initially if converting OP to FOR_TYPE is a zero-extension. */
4430 register tree type = TREE_TYPE (op);
4431 register unsigned final_prec
4432 = TYPE_PRECISION (for_type != 0 ? for_type : type);
4434 = (for_type != 0 && for_type != type
4435 && final_prec > TYPE_PRECISION (type)
4436 && TREE_UNSIGNED (type));
4437 register tree win = op;
4439 while (TREE_CODE (op) == NOP_EXPR)
4441 register int bitschange
4442 = TYPE_PRECISION (TREE_TYPE (op))
4443 - TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (op, 0)));
4445 /* Truncations are many-one so cannot be removed.
4446 Unless we are later going to truncate down even farther. */
4448 && final_prec > TYPE_PRECISION (TREE_TYPE (op)))
4451 /* See what's inside this conversion. If we decide to strip it,
4453 op = TREE_OPERAND (op, 0);
4455 /* If we have not stripped any zero-extensions (uns is 0),
4456 we can strip any kind of extension.
4457 If we have previously stripped a zero-extension,
4458 only zero-extensions can safely be stripped.
4459 Any extension can be stripped if the bits it would produce
4460 are all going to be discarded later by truncating to FOR_TYPE. */
4464 if (! uns || final_prec <= TYPE_PRECISION (TREE_TYPE (op)))
4466 /* TREE_UNSIGNED says whether this is a zero-extension.
4467 Let's avoid computing it if it does not affect WIN
4468 and if UNS will not be needed again. */
4469 if ((uns || TREE_CODE (op) == NOP_EXPR)
4470 && TREE_UNSIGNED (TREE_TYPE (op)))
4478 if (TREE_CODE (op) == COMPONENT_REF
4479 /* Since type_for_size always gives an integer type. */
4480 && TREE_CODE (type) != REAL_TYPE
4481 /* Don't crash if field not laid out yet. */
4482 && DECL_SIZE (TREE_OPERAND (op, 1)) != 0)
4484 unsigned innerprec = TREE_INT_CST_LOW (DECL_SIZE (TREE_OPERAND (op, 1)));
4485 type = type_for_size (innerprec, TREE_UNSIGNED (TREE_OPERAND (op, 1)));
4487 /* We can get this structure field in the narrowest type it fits in.
4488 If FOR_TYPE is 0, do this only for a field that matches the
4489 narrower type exactly and is aligned for it
4490 The resulting extension to its nominal type (a fullword type)
4491 must fit the same conditions as for other extensions. */
4493 if (innerprec < TYPE_PRECISION (TREE_TYPE (op))
4494 && (for_type || ! DECL_BIT_FIELD (TREE_OPERAND (op, 1)))
4495 && (! uns || final_prec <= innerprec
4496 || TREE_UNSIGNED (TREE_OPERAND (op, 1)))
4499 win = build (COMPONENT_REF, type, TREE_OPERAND (op, 0),
4500 TREE_OPERAND (op, 1));
4501 TREE_SIDE_EFFECTS (win) = TREE_SIDE_EFFECTS (op);
4502 TREE_THIS_VOLATILE (win) = TREE_THIS_VOLATILE (op);
4503 TREE_RAISES (win) = TREE_RAISES (op);
4509 /* Return OP or a simpler expression for a narrower value
4510 which can be sign-extended or zero-extended to give back OP.
4511 Store in *UNSIGNEDP_PTR either 1 if the value should be zero-extended
4512 or 0 if the value should be sign-extended. */
4515 get_narrower (op, unsignedp_ptr)
4519 register int uns = 0;
4521 register tree win = op;
4523 while (TREE_CODE (op) == NOP_EXPR)
4525 register int bitschange
4526 = TYPE_PRECISION (TREE_TYPE (op))
4527 - TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (op, 0)));
4529 /* Truncations are many-one so cannot be removed. */
4533 /* See what's inside this conversion. If we decide to strip it,
4535 op = TREE_OPERAND (op, 0);
4539 /* An extension: the outermost one can be stripped,
4540 but remember whether it is zero or sign extension. */
4542 uns = TREE_UNSIGNED (TREE_TYPE (op));
4543 /* Otherwise, if a sign extension has been stripped,
4544 only sign extensions can now be stripped;
4545 if a zero extension has been stripped, only zero-extensions. */
4546 else if (uns != TREE_UNSIGNED (TREE_TYPE (op)))
4550 else /* bitschange == 0 */
4552 /* A change in nominal type can always be stripped, but we must
4553 preserve the unsignedness. */
4555 uns = TREE_UNSIGNED (TREE_TYPE (op));
4562 if (TREE_CODE (op) == COMPONENT_REF
4563 /* Since type_for_size always gives an integer type. */
4564 && TREE_CODE (TREE_TYPE (op)) != REAL_TYPE)
4566 unsigned innerprec = TREE_INT_CST_LOW (DECL_SIZE (TREE_OPERAND (op, 1)));
4567 tree type = type_for_size (innerprec, TREE_UNSIGNED (op));
4569 /* We can get this structure field in a narrower type that fits it,
4570 but the resulting extension to its nominal type (a fullword type)
4571 must satisfy the same conditions as for other extensions.
4573 Do this only for fields that are aligned (not bit-fields),
4574 because when bit-field insns will be used there is no
4575 advantage in doing this. */
4577 if (innerprec < TYPE_PRECISION (TREE_TYPE (op))
4578 && ! DECL_BIT_FIELD (TREE_OPERAND (op, 1))
4579 && (first || uns == TREE_UNSIGNED (TREE_OPERAND (op, 1)))
4583 uns = TREE_UNSIGNED (TREE_OPERAND (op, 1));
4584 win = build (COMPONENT_REF, type, TREE_OPERAND (op, 0),
4585 TREE_OPERAND (op, 1));
4586 TREE_SIDE_EFFECTS (win) = TREE_SIDE_EFFECTS (op);
4587 TREE_THIS_VOLATILE (win) = TREE_THIS_VOLATILE (op);
4588 TREE_RAISES (win) = TREE_RAISES (op);
4591 *unsignedp_ptr = uns;
4595 /* Nonzero if integer constant C has a value that is permissible
4596 for type TYPE (an INTEGER_TYPE). */
4599 int_fits_type_p (c, type)
4602 if (TREE_UNSIGNED (type))
4603 return (! (TREE_CODE (TYPE_MAX_VALUE (type)) == INTEGER_CST
4604 && INT_CST_LT_UNSIGNED (TYPE_MAX_VALUE (type), c))
4605 && ! (TREE_CODE (TYPE_MIN_VALUE (type)) == INTEGER_CST
4606 && INT_CST_LT_UNSIGNED (c, TYPE_MIN_VALUE (type)))
4607 /* Negative ints never fit unsigned types. */
4608 && ! (TREE_INT_CST_HIGH (c) < 0
4609 && ! TREE_UNSIGNED (TREE_TYPE (c))));
4611 return (! (TREE_CODE (TYPE_MAX_VALUE (type)) == INTEGER_CST
4612 && INT_CST_LT (TYPE_MAX_VALUE (type), c))
4613 && ! (TREE_CODE (TYPE_MIN_VALUE (type)) == INTEGER_CST
4614 && INT_CST_LT (c, TYPE_MIN_VALUE (type)))
4615 /* Unsigned ints with top bit set never fit signed types. */
4616 && ! (TREE_INT_CST_HIGH (c) < 0
4617 && TREE_UNSIGNED (TREE_TYPE (c))));
4620 /* Return the innermost context enclosing DECL that is
4621 a FUNCTION_DECL, or zero if none. */
4624 decl_function_context (decl)
4629 if (TREE_CODE (decl) == ERROR_MARK)
4632 if (TREE_CODE (decl) == SAVE_EXPR)
4633 context = SAVE_EXPR_CONTEXT (decl);
4635 context = DECL_CONTEXT (decl);
4637 while (context && TREE_CODE (context) != FUNCTION_DECL)
4639 if (TREE_CODE_CLASS (TREE_CODE (context)) == 't')
4640 context = TYPE_CONTEXT (context);
4641 else if (TREE_CODE_CLASS (TREE_CODE (context)) == 'd')
4642 context = DECL_CONTEXT (context);
4643 else if (TREE_CODE (context) == BLOCK)
4644 context = BLOCK_SUPERCONTEXT (context);
4646 /* Unhandled CONTEXT !? */
4653 /* Return the innermost context enclosing DECL that is
4654 a RECORD_TYPE, UNION_TYPE or QUAL_UNION_TYPE, or zero if none.
4655 TYPE_DECLs and FUNCTION_DECLs are transparent to this function. */
4658 decl_type_context (decl)
4661 tree context = DECL_CONTEXT (decl);
4665 if (TREE_CODE (context) == RECORD_TYPE
4666 || TREE_CODE (context) == UNION_TYPE
4667 || TREE_CODE (context) == QUAL_UNION_TYPE)
4669 if (TREE_CODE (context) == TYPE_DECL
4670 || TREE_CODE (context) == FUNCTION_DECL)
4671 context = DECL_CONTEXT (context);
4672 else if (TREE_CODE (context) == BLOCK)
4673 context = BLOCK_SUPERCONTEXT (context);
4675 /* Unhandled CONTEXT!? */
4681 /* Print debugging information about the obstack O, named STR. */
4684 print_obstack_statistics (str, o)
4688 struct _obstack_chunk *chunk = o->chunk;
4692 n_alloc += o->next_free - chunk->contents;
4693 chunk = chunk->prev;
4697 n_alloc += chunk->limit - &chunk->contents[0];
4698 chunk = chunk->prev;
4700 fprintf (stderr, "obstack %s: %u bytes, %d chunks\n",
4701 str, n_alloc, n_chunks);
4704 /* Print debugging information about tree nodes generated during the compile,
4705 and any language-specific information. */
4708 dump_tree_statistics ()
4710 #ifdef GATHER_STATISTICS
4712 int total_nodes, total_bytes;
4715 fprintf (stderr, "\n??? tree nodes created\n\n");
4716 #ifdef GATHER_STATISTICS
4717 fprintf (stderr, "Kind Nodes Bytes\n");
4718 fprintf (stderr, "-------------------------------------\n");
4719 total_nodes = total_bytes = 0;
4720 for (i = 0; i < (int) all_kinds; i++)
4722 fprintf (stderr, "%-20s %6d %9d\n", tree_node_kind_names[i],
4723 tree_node_counts[i], tree_node_sizes[i]);
4724 total_nodes += tree_node_counts[i];
4725 total_bytes += tree_node_sizes[i];
4727 fprintf (stderr, "%-20s %9d\n", "identifier names", id_string_size);
4728 fprintf (stderr, "-------------------------------------\n");
4729 fprintf (stderr, "%-20s %6d %9d\n", "Total", total_nodes, total_bytes);
4730 fprintf (stderr, "-------------------------------------\n");
4732 fprintf (stderr, "(No per-node statistics)\n");
4734 print_obstack_statistics ("permanent_obstack", &permanent_obstack);
4735 print_obstack_statistics ("maybepermanent_obstack", &maybepermanent_obstack);
4736 print_obstack_statistics ("temporary_obstack", &temporary_obstack);
4737 print_obstack_statistics ("momentary_obstack", &momentary_obstack);
4738 print_obstack_statistics ("temp_decl_obstack", &temp_decl_obstack);
4739 print_lang_statistics ();
4742 #define FILE_FUNCTION_PREFIX_LEN 9
4744 #ifndef NO_DOLLAR_IN_LABEL
4745 #define FILE_FUNCTION_FORMAT "_GLOBAL_$%s$%s"
4746 #else /* NO_DOLLAR_IN_LABEL */
4747 #ifndef NO_DOT_IN_LABEL
4748 #define FILE_FUNCTION_FORMAT "_GLOBAL_.%s.%s"
4749 #else /* NO_DOT_IN_LABEL */
4750 #define FILE_FUNCTION_FORMAT "_GLOBAL__%s_%s"
4751 #endif /* NO_DOT_IN_LABEL */
4752 #endif /* NO_DOLLAR_IN_LABEL */
4754 extern char * first_global_object_name;
4755 extern char * weak_global_object_name;
4757 /* Appends 6 random characters to TEMPLATE to (hopefully) avoid name
4758 clashes in cases where we can't reliably choose a unique name.
4760 Derived from mkstemp.c in libiberty. */
4763 append_random_chars (template)
4766 static const char letters[]
4767 = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
4768 static unsigned HOST_WIDE_INT value;
4769 unsigned HOST_WIDE_INT v;
4771 #ifdef HAVE_GETTIMEOFDAY
4775 template += strlen (template);
4777 #ifdef HAVE_GETTIMEOFDAY
4778 /* Get some more or less random data. */
4779 gettimeofday (&tv, NULL);
4780 value += ((unsigned HOST_WIDE_INT) tv.tv_usec << 16) ^ tv.tv_sec ^ getpid ();
4787 /* Fill in the random bits. */
4788 template[0] = letters[v % 62];
4790 template[1] = letters[v % 62];
4792 template[2] = letters[v % 62];
4794 template[3] = letters[v % 62];
4796 template[4] = letters[v % 62];
4798 template[5] = letters[v % 62];
4803 /* Generate a name for a function unique to this translation unit.
4804 TYPE is some string to identify the purpose of this function to the
4805 linker or collect2. */
4808 get_file_function_name_long (type)
4814 if (first_global_object_name)
4815 p = first_global_object_name;
4818 /* We don't have anything that we know to be unique to this translation
4819 unit, so use what we do have and throw in some randomness. */
4821 const char *name = weak_global_object_name;
4822 const char *file = main_input_filename;
4827 file = input_filename;
4829 p = (char *) alloca (7 + strlen (name) + strlen (file));
4831 sprintf (p, "%s%s", name, file);
4832 append_random_chars (p);
4835 buf = (char *) alloca (sizeof (FILE_FUNCTION_FORMAT) + strlen (p)
4838 /* Set up the name of the file-level functions we may need. */
4839 /* Use a global object (which is already required to be unique over
4840 the program) rather than the file name (which imposes extra
4841 constraints). -- Raeburn@MIT.EDU, 10 Jan 1990. */
4842 sprintf (buf, FILE_FUNCTION_FORMAT, type, p);
4844 /* Don't need to pull weird characters out of global names. */
4845 if (p != first_global_object_name)
4847 for (p = buf+11; *p; p++)
4848 if (! ((*p >= '0' && *p <= '9')
4849 #if 0 /* we always want labels, which are valid C++ identifiers (+ `$') */
4850 #ifndef ASM_IDENTIFY_GCC /* this is required if `.' is invalid -- k. raeburn */
4854 #ifndef NO_DOLLAR_IN_LABEL /* this for `$'; unlikely, but... -- kr */
4857 #ifndef NO_DOT_IN_LABEL /* this for `.'; unlikely, but... */
4860 || (*p >= 'A' && *p <= 'Z')
4861 || (*p >= 'a' && *p <= 'z')))
4865 return get_identifier (buf);
4868 /* If KIND=='I', return a suitable global initializer (constructor) name.
4869 If KIND=='D', return a suitable global clean-up (destructor) name. */
4872 get_file_function_name (kind)
4879 return get_file_function_name_long (p);
4883 /* Expand (the constant part of) a SET_TYPE CONSTRUCTOR node.
4884 The result is placed in BUFFER (which has length BIT_SIZE),
4885 with one bit in each char ('\000' or '\001').
4887 If the constructor is constant, NULL_TREE is returned.
4888 Otherwise, a TREE_LIST of the non-constant elements is emitted. */
4891 get_set_constructor_bits (init, buffer, bit_size)
4898 HOST_WIDE_INT domain_min
4899 = TREE_INT_CST_LOW (TYPE_MIN_VALUE (TYPE_DOMAIN (TREE_TYPE (init))));
4900 tree non_const_bits = NULL_TREE;
4901 for (i = 0; i < bit_size; i++)
4904 for (vals = TREE_OPERAND (init, 1);
4905 vals != NULL_TREE; vals = TREE_CHAIN (vals))
4907 if (TREE_CODE (TREE_VALUE (vals)) != INTEGER_CST
4908 || (TREE_PURPOSE (vals) != NULL_TREE
4909 && TREE_CODE (TREE_PURPOSE (vals)) != INTEGER_CST))
4911 = tree_cons (TREE_PURPOSE (vals), TREE_VALUE (vals), non_const_bits);
4912 else if (TREE_PURPOSE (vals) != NULL_TREE)
4914 /* Set a range of bits to ones. */
4915 HOST_WIDE_INT lo_index
4916 = TREE_INT_CST_LOW (TREE_PURPOSE (vals)) - domain_min;
4917 HOST_WIDE_INT hi_index
4918 = TREE_INT_CST_LOW (TREE_VALUE (vals)) - domain_min;
4919 if (lo_index < 0 || lo_index >= bit_size
4920 || hi_index < 0 || hi_index >= bit_size)
4922 for ( ; lo_index <= hi_index; lo_index++)
4923 buffer[lo_index] = 1;
4927 /* Set a single bit to one. */
4929 = TREE_INT_CST_LOW (TREE_VALUE (vals)) - domain_min;
4930 if (index < 0 || index >= bit_size)
4932 error ("invalid initializer for bit string");
4938 return non_const_bits;
4941 /* Expand (the constant part of) a SET_TYPE CONSTRUCTOR node.
4942 The result is placed in BUFFER (which is an array of bytes).
4943 If the constructor is constant, NULL_TREE is returned.
4944 Otherwise, a TREE_LIST of the non-constant elements is emitted. */
4947 get_set_constructor_bytes (init, buffer, wd_size)
4949 unsigned char *buffer;
4953 int set_word_size = BITS_PER_UNIT;
4954 int bit_size = wd_size * set_word_size;
4956 unsigned char *bytep = buffer;
4957 char *bit_buffer = (char *) alloca(bit_size);
4958 tree non_const_bits = get_set_constructor_bits (init, bit_buffer, bit_size);
4960 for (i = 0; i < wd_size; i++)
4963 for (i = 0; i < bit_size; i++)
4967 if (BYTES_BIG_ENDIAN)
4968 *bytep |= (1 << (set_word_size - 1 - bit_pos));
4970 *bytep |= 1 << bit_pos;
4973 if (bit_pos >= set_word_size)
4974 bit_pos = 0, bytep++;
4976 return non_const_bits;
4979 #if defined ENABLE_CHECKING && (__GNUC__ > 2 || __GNUC_MINOR__ > 6)
4980 /* Complain that the tree code of NODE does not match the expected CODE.
4981 FILE, LINE, and FUNCTION are of the caller. */
4983 tree_check_failed (node, code, file, line, function)
4985 enum tree_code code;
4988 const char *function;
4990 error ("Tree check: expected %s, have %s",
4991 tree_code_name[code], tree_code_name[TREE_CODE (node)]);
4992 fancy_abort (file, line, function);
4995 /* Similar to above, except that we check for a class of tree
4996 code, given in CL. */
4998 tree_class_check_failed (node, cl, file, line, function)
5003 const char *function;
5005 error ("Tree check: expected class '%c', have '%c' (%s)",
5006 cl, TREE_CODE_CLASS (TREE_CODE (node)),
5007 tree_code_name[TREE_CODE (node)]);
5008 fancy_abort (file, line, function);
5011 #endif /* ENABLE_CHECKING */
5013 /* Return the alias set for T, which may be either a type or an
5020 if (!flag_strict_aliasing || !lang_get_alias_set)
5021 /* If we're not doing any lanaguage-specific alias analysis, just
5022 assume everything aliases everything else. */
5025 return (*lang_get_alias_set) (t);
5028 /* Return a brand-new alias set. */
5033 static int last_alias_set;
5034 if (flag_strict_aliasing)
5035 return ++last_alias_set;