1 /* Language-independent node constructors for parse phase of GNU compiler.
2 Copyright (C) 1987, 1988, 1992 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, 675 Mass Ave, Cambridge, MA 02139, USA. */
21 /* This file contains the low level primitives for operating on tree nodes,
22 including allocation, list operations, interning of identifiers,
23 construction of data type nodes and statement nodes,
24 and construction of type conversion nodes. It also contains
25 tables index by tree code that describe how to take apart
28 It is intended to be language-independent, but occasionally
29 calls language-dependent routines defined (for C) in typecheck.c.
31 The low-level allocation routines oballoc and permalloc
32 are used also for allocating many other kinds of objects
33 by all passes of the compiler. */
43 #define obstack_chunk_alloc xmalloc
44 #define obstack_chunk_free free
46 /* Tree nodes of permanent duration are allocated in this obstack.
47 They are the identifier nodes, and everything outside of
48 the bodies and parameters of function definitions. */
50 struct obstack permanent_obstack;
52 /* The initial RTL, and all ..._TYPE nodes, in a function
53 are allocated in this obstack. Usually they are freed at the
54 end of the function, but if the function is inline they are saved.
55 For top-level functions, this is maybepermanent_obstack.
56 Separate obstacks are made for nested functions. */
58 struct obstack *function_maybepermanent_obstack;
60 /* This is the function_maybepermanent_obstack for top-level functions. */
62 struct obstack maybepermanent_obstack;
64 /* The contents of the current function definition are allocated
65 in this obstack, and all are freed at the end of the function.
66 For top-level functions, this is temporary_obstack.
67 Separate obstacks are made for nested functions. */
69 struct obstack *function_obstack;
71 /* This is used for reading initializers of global variables. */
73 struct obstack temporary_obstack;
75 /* The tree nodes of an expression are allocated
76 in this obstack, and all are freed at the end of the expression. */
78 struct obstack momentary_obstack;
80 /* The tree nodes of a declarator are allocated
81 in this obstack, and all are freed when the declarator
84 static struct obstack temp_decl_obstack;
86 /* This points at either permanent_obstack
87 or the current function_maybepermanent_obstack. */
89 struct obstack *saveable_obstack;
91 /* This is same as saveable_obstack during parse and expansion phase;
92 it points to the current function's obstack during optimization.
93 This is the obstack to be used for creating rtl objects. */
95 struct obstack *rtl_obstack;
97 /* This points at either permanent_obstack or the current function_obstack. */
99 struct obstack *current_obstack;
101 /* This points at either permanent_obstack or the current function_obstack
102 or momentary_obstack. */
104 struct obstack *expression_obstack;
106 /* Stack of obstack selections for push_obstacks and pop_obstacks. */
110 struct obstack_stack *next;
111 struct obstack *current;
112 struct obstack *saveable;
113 struct obstack *expression;
117 struct obstack_stack *obstack_stack;
119 /* Obstack for allocating struct obstack_stack entries. */
121 static struct obstack obstack_stack_obstack;
123 /* Addresses of first objects in some obstacks.
124 This is for freeing their entire contents. */
125 char *maybepermanent_firstobj;
126 char *temporary_firstobj;
127 char *momentary_firstobj;
128 char *temp_decl_firstobj;
130 /* Nonzero means all ..._TYPE nodes should be allocated permanently. */
132 int all_types_permanent;
134 /* Stack of places to restore the momentary obstack back to. */
136 struct momentary_level
138 /* Pointer back to previous such level. */
139 struct momentary_level *prev;
140 /* First object allocated within this level. */
142 /* Value of expression_obstack saved at entry to this level. */
143 struct obstack *obstack;
146 struct momentary_level *momentary_stack;
148 /* Table indexed by tree code giving a string containing a character
149 classifying the tree code. Possibilities are
150 t, d, s, c, r, <, 1, 2 and e. See tree.def for details. */
152 #define DEFTREECODE(SYM, NAME, TYPE, LENGTH) TYPE,
154 char *standard_tree_code_type[] = {
159 /* Table indexed by tree code giving number of expression
160 operands beyond the fixed part of the node structure.
161 Not used for types or decls. */
163 #define DEFTREECODE(SYM, NAME, TYPE, LENGTH) LENGTH,
165 int standard_tree_code_length[] = {
170 /* Names of tree components.
171 Used for printing out the tree and error messages. */
172 #define DEFTREECODE(SYM, NAME, TYPE, LEN) NAME,
174 char *standard_tree_code_name[] = {
179 /* Table indexed by tree code giving a string containing a character
180 classifying the tree code. Possibilities are
181 t, d, s, c, r, e, <, 1 and 2. See tree.def for details. */
183 char **tree_code_type;
185 /* Table indexed by tree code giving number of expression
186 operands beyond the fixed part of the node structure.
187 Not used for types or decls. */
189 int *tree_code_length;
191 /* Table indexed by tree code giving name of tree code, as a string. */
193 char **tree_code_name;
195 /* Statistics-gathering stuff. */
216 int tree_node_counts[(int)all_kinds];
217 int tree_node_sizes[(int)all_kinds];
218 int id_string_size = 0;
220 char *tree_node_kind_names[] = {
238 /* Hash table for uniquizing IDENTIFIER_NODEs by name. */
240 #define MAX_HASH_TABLE 1009
241 static tree hash_table[MAX_HASH_TABLE]; /* id hash buckets */
243 /* 0 while creating built-in identifiers. */
244 static int do_identifier_warnings;
246 /* Unique id for next decl created. */
247 static int next_decl_uid;
249 extern char *mode_name[];
251 void gcc_obstack_init ();
252 static tree stabilize_reference_1 ();
254 /* Init the principal obstacks. */
259 gcc_obstack_init (&obstack_stack_obstack);
260 gcc_obstack_init (&permanent_obstack);
262 gcc_obstack_init (&temporary_obstack);
263 temporary_firstobj = (char *) obstack_alloc (&temporary_obstack, 0);
264 gcc_obstack_init (&momentary_obstack);
265 momentary_firstobj = (char *) obstack_alloc (&momentary_obstack, 0);
266 gcc_obstack_init (&maybepermanent_obstack);
267 maybepermanent_firstobj
268 = (char *) obstack_alloc (&maybepermanent_obstack, 0);
269 gcc_obstack_init (&temp_decl_obstack);
270 temp_decl_firstobj = (char *) obstack_alloc (&temp_decl_obstack, 0);
272 function_obstack = &temporary_obstack;
273 function_maybepermanent_obstack = &maybepermanent_obstack;
274 current_obstack = &permanent_obstack;
275 expression_obstack = &permanent_obstack;
276 rtl_obstack = saveable_obstack = &permanent_obstack;
278 /* Init the hash table of identifiers. */
279 bzero (hash_table, sizeof hash_table);
283 gcc_obstack_init (obstack)
284 struct obstack *obstack;
286 /* Let particular systems override the size of a chunk. */
287 #ifndef OBSTACK_CHUNK_SIZE
288 #define OBSTACK_CHUNK_SIZE 0
290 /* Let them override the alloc and free routines too. */
291 #ifndef OBSTACK_CHUNK_ALLOC
292 #define OBSTACK_CHUNK_ALLOC xmalloc
294 #ifndef OBSTACK_CHUNK_FREE
295 #define OBSTACK_CHUNK_FREE free
297 _obstack_begin (obstack, OBSTACK_CHUNK_SIZE, 0,
298 (void *(*) ()) OBSTACK_CHUNK_ALLOC,
299 (void (*) ()) OBSTACK_CHUNK_FREE);
302 /* Save all variables describing the current status into the structure *P.
303 This is used before starting a nested function. */
309 p->all_types_permanent = all_types_permanent;
310 p->momentary_stack = momentary_stack;
311 p->maybepermanent_firstobj = maybepermanent_firstobj;
312 p->momentary_firstobj = momentary_firstobj;
313 p->function_obstack = function_obstack;
314 p->function_maybepermanent_obstack = function_maybepermanent_obstack;
315 p->current_obstack = current_obstack;
316 p->expression_obstack = expression_obstack;
317 p->saveable_obstack = saveable_obstack;
318 p->rtl_obstack = rtl_obstack;
320 function_obstack = (struct obstack *) xmalloc (sizeof (struct obstack));
321 gcc_obstack_init (function_obstack);
323 function_maybepermanent_obstack
324 = (struct obstack *) xmalloc (sizeof (struct obstack));
325 gcc_obstack_init (function_maybepermanent_obstack);
327 current_obstack = &permanent_obstack;
328 expression_obstack = &permanent_obstack;
329 rtl_obstack = saveable_obstack = &permanent_obstack;
331 momentary_firstobj = (char *) obstack_finish (&momentary_obstack);
332 maybepermanent_firstobj
333 = (char *) obstack_finish (function_maybepermanent_obstack);
336 /* Restore all variables describing the current status from the structure *P.
337 This is used after a nested function. */
340 restore_tree_status (p)
343 all_types_permanent = p->all_types_permanent;
344 momentary_stack = p->momentary_stack;
346 obstack_free (&momentary_obstack, momentary_firstobj);
347 obstack_free (function_obstack, 0);
348 obstack_free (function_maybepermanent_obstack, 0);
349 free (function_obstack);
351 momentary_firstobj = p->momentary_firstobj;
352 maybepermanent_firstobj = p->maybepermanent_firstobj;
353 function_obstack = p->function_obstack;
354 function_maybepermanent_obstack = p->function_maybepermanent_obstack;
355 current_obstack = p->current_obstack;
356 expression_obstack = p->expression_obstack;
357 saveable_obstack = p->saveable_obstack;
358 rtl_obstack = p->rtl_obstack;
361 /* Start allocating on the temporary (per function) obstack.
362 This is done in start_function before parsing the function body,
363 and before each initialization at top level, and to go back
364 to temporary allocation after doing end_temporary_allocation. */
367 temporary_allocation ()
369 /* Note that function_obstack at top level points to temporary_obstack.
370 But within a nested function context, it is a separate obstack. */
371 current_obstack = function_obstack;
372 expression_obstack = function_obstack;
373 rtl_obstack = saveable_obstack = function_maybepermanent_obstack;
377 /* Start allocating on the permanent obstack but don't
378 free the temporary data. After calling this, call
379 `permanent_allocation' to fully resume permanent allocation status. */
382 end_temporary_allocation ()
384 current_obstack = &permanent_obstack;
385 expression_obstack = &permanent_obstack;
386 rtl_obstack = saveable_obstack = &permanent_obstack;
389 /* Resume allocating on the temporary obstack, undoing
390 effects of `end_temporary_allocation'. */
393 resume_temporary_allocation ()
395 current_obstack = function_obstack;
396 expression_obstack = function_obstack;
397 rtl_obstack = saveable_obstack = function_maybepermanent_obstack;
400 /* While doing temporary allocation, switch to allocating in such a
401 way as to save all nodes if the function is inlined. Call
402 resume_temporary_allocation to go back to ordinary temporary
406 saveable_allocation ()
408 /* Note that function_obstack at top level points to temporary_obstack.
409 But within a nested function context, it is a separate obstack. */
410 expression_obstack = current_obstack = saveable_obstack;
413 /* Switch to current obstack CURRENT and maybepermanent obstack SAVEABLE,
414 recording the previously current obstacks on a stack.
415 This does not free any storage in any obstack. */
418 push_obstacks (current, saveable)
419 struct obstack *current, *saveable;
421 struct obstack_stack *p
422 = (struct obstack_stack *) obstack_alloc (&obstack_stack_obstack,
423 (sizeof (struct obstack_stack)));
425 p->current = current_obstack;
426 p->saveable = saveable_obstack;
427 p->expression = expression_obstack;
428 p->rtl = rtl_obstack;
429 p->next = obstack_stack;
432 current_obstack = current;
433 expression_obstack = current;
434 rtl_obstack = saveable_obstack = saveable;
437 /* Save the current set of obstacks, but don't change them. */
440 push_obstacks_nochange ()
442 struct obstack_stack *p
443 = (struct obstack_stack *) obstack_alloc (&obstack_stack_obstack,
444 (sizeof (struct obstack_stack)));
446 p->current = current_obstack;
447 p->saveable = saveable_obstack;
448 p->expression = expression_obstack;
449 p->rtl = rtl_obstack;
450 p->next = obstack_stack;
454 /* Pop the obstack selection stack. */
459 struct obstack_stack *p = obstack_stack;
460 obstack_stack = p->next;
462 current_obstack = p->current;
463 saveable_obstack = p->saveable;
464 expression_obstack = p->expression;
465 rtl_obstack = p->rtl;
467 obstack_free (&obstack_stack_obstack, p);
470 /* Nonzero if temporary allocation is currently in effect.
471 Zero if currently doing permanent allocation. */
474 allocation_temporary_p ()
476 return current_obstack != &permanent_obstack;
479 /* Go back to allocating on the permanent obstack
480 and free everything in the temporary obstack.
481 This is done in finish_function after fully compiling a function. */
484 permanent_allocation ()
486 /* Free up previous temporary obstack data */
487 obstack_free (&temporary_obstack, temporary_firstobj);
488 obstack_free (&momentary_obstack, momentary_firstobj);
489 obstack_free (&maybepermanent_obstack, maybepermanent_firstobj);
490 obstack_free (&temp_decl_obstack, temp_decl_firstobj);
492 current_obstack = &permanent_obstack;
493 expression_obstack = &permanent_obstack;
494 rtl_obstack = saveable_obstack = &permanent_obstack;
497 /* Save permanently everything on the maybepermanent_obstack. */
502 maybepermanent_firstobj
503 = (char *) obstack_alloc (function_maybepermanent_obstack, 0);
507 preserve_initializer ()
510 = (char *) obstack_alloc (&temporary_obstack, 0);
512 = (char *) obstack_alloc (&momentary_obstack, 0);
513 maybepermanent_firstobj
514 = (char *) obstack_alloc (function_maybepermanent_obstack, 0);
517 /* Start allocating new rtl in current_obstack.
518 Use resume_temporary_allocation
519 to go back to allocating rtl in saveable_obstack. */
522 rtl_in_current_obstack ()
524 rtl_obstack = current_obstack;
527 /* Temporarily allocate rtl from saveable_obstack. Return 1 if we were
528 previously allocating it from current_obstack. */
531 rtl_in_saveable_obstack ()
533 if (rtl_obstack == current_obstack)
535 rtl_obstack = saveable_obstack;
542 /* Allocate SIZE bytes in the current obstack
543 and return a pointer to them.
544 In practice the current obstack is always the temporary one. */
550 return (char *) obstack_alloc (current_obstack, size);
553 /* Free the object PTR in the current obstack
554 as well as everything allocated since PTR.
555 In practice the current obstack is always the temporary one. */
561 obstack_free (current_obstack, ptr);
564 /* Allocate SIZE bytes in the permanent obstack
565 and return a pointer to them. */
571 return (char *) obstack_alloc (&permanent_obstack, size);
574 /* Allocate NELEM items of SIZE bytes in the permanent obstack
575 and return a pointer to them. The storage is cleared before
576 returning the value. */
579 perm_calloc (nelem, size)
583 char *rval = (char *) obstack_alloc (&permanent_obstack, nelem * size);
584 bzero (rval, nelem * size);
588 /* Allocate SIZE bytes in the saveable obstack
589 and return a pointer to them. */
595 return (char *) obstack_alloc (saveable_obstack, size);
598 /* Print out which obstack an object is in. */
601 debug_obstack (object)
604 struct obstack *obstack = NULL;
605 char *obstack_name = NULL;
608 for (p = outer_function_chain; p; p = p->next)
610 if (_obstack_allocated_p (p->function_obstack, object))
612 obstack = p->function_obstack;
613 obstack_name = "containing function obstack";
615 if (_obstack_allocated_p (p->function_maybepermanent_obstack, object))
617 obstack = p->function_maybepermanent_obstack;
618 obstack_name = "containing function maybepermanent obstack";
622 if (_obstack_allocated_p (&obstack_stack_obstack, object))
624 obstack = &obstack_stack_obstack;
625 obstack_name = "obstack_stack_obstack";
627 else if (_obstack_allocated_p (function_obstack, object))
629 obstack = function_obstack;
630 obstack_name = "function obstack";
632 else if (_obstack_allocated_p (&permanent_obstack, object))
634 obstack = &permanent_obstack;
635 obstack_name = "permanent_obstack";
637 else if (_obstack_allocated_p (&momentary_obstack, object))
639 obstack = &momentary_obstack;
640 obstack_name = "momentary_obstack";
642 else if (_obstack_allocated_p (function_maybepermanent_obstack, object))
644 obstack = function_maybepermanent_obstack;
645 obstack_name = "function maybepermanent obstack";
647 else if (_obstack_allocated_p (&temp_decl_obstack, object))
649 obstack = &temp_decl_obstack;
650 obstack_name = "temp_decl_obstack";
653 /* Check to see if the object is in the free area of the obstack. */
656 if (object >= obstack->next_free
657 && object < obstack->chunk_limit)
658 fprintf (stderr, "object in free portion of obstack %s.\n",
661 fprintf (stderr, "object allocated from %s.\n", obstack_name);
664 fprintf (stderr, "object not allocated from any obstack.\n");
667 /* Return 1 if OBJ is in the permanent obstack.
668 This is slow, and should be used only for debugging.
669 Use TREE_PERMANENT for other purposes. */
672 object_permanent_p (obj)
675 return _obstack_allocated_p (&permanent_obstack, obj);
678 /* Start a level of momentary allocation.
679 In C, each compound statement has its own level
680 and that level is freed at the end of each statement.
681 All expression nodes are allocated in the momentary allocation level. */
686 struct momentary_level *tem
687 = (struct momentary_level *) obstack_alloc (&momentary_obstack,
688 sizeof (struct momentary_level));
689 tem->prev = momentary_stack;
690 tem->base = (char *) obstack_base (&momentary_obstack);
691 tem->obstack = expression_obstack;
692 momentary_stack = tem;
693 expression_obstack = &momentary_obstack;
696 /* Free all the storage in the current momentary-allocation level.
697 In C, this happens at the end of each statement. */
702 obstack_free (&momentary_obstack, momentary_stack->base);
705 /* Discard a level of momentary allocation.
706 In C, this happens at the end of each compound statement.
707 Restore the status of expression node allocation
708 that was in effect before this level was created. */
713 struct momentary_level *tem = momentary_stack;
714 momentary_stack = tem->prev;
715 expression_obstack = tem->obstack;
716 obstack_free (&momentary_obstack, tem);
719 /* Call when starting to parse a declaration:
720 make expressions in the declaration last the length of the function.
721 Returns an argument that should be passed to resume_momentary later. */
726 register int tem = expression_obstack == &momentary_obstack;
727 expression_obstack = saveable_obstack;
731 /* Call when finished parsing a declaration:
732 restore the treatment of node-allocation that was
733 in effect before the suspension.
734 YES should be the value previously returned by suspend_momentary. */
737 resume_momentary (yes)
741 expression_obstack = &momentary_obstack;
744 /* Init the tables indexed by tree code.
745 Note that languages can add to these tables to define their own codes. */
750 tree_code_type = (char **) xmalloc (sizeof (standard_tree_code_type));
751 tree_code_length = (int *) xmalloc (sizeof (standard_tree_code_length));
752 tree_code_name = (char **) xmalloc (sizeof (standard_tree_code_name));
753 bcopy (standard_tree_code_type, tree_code_type,
754 sizeof (standard_tree_code_type));
755 bcopy (standard_tree_code_length, tree_code_length,
756 sizeof (standard_tree_code_length));
757 bcopy (standard_tree_code_name, tree_code_name,
758 sizeof (standard_tree_code_name));
761 /* Return a newly allocated node of code CODE.
762 Initialize the node's unique id and its TREE_PERMANENT flag.
763 For decl and type nodes, some other fields are initialized.
764 The rest of the node is initialized to zero.
766 Achoo! I got a code in the node. */
773 register int type = TREE_CODE_CLASS (code);
775 register struct obstack *obstack = current_obstack;
777 register tree_node_kind kind;
781 case 'd': /* A decl node */
782 #ifdef GATHER_STATISTICS
785 length = sizeof (struct tree_decl);
786 /* All decls in an inline function need to be saved. */
787 if (obstack != &permanent_obstack)
788 obstack = saveable_obstack;
789 /* PARM_DECLs always go on saveable_obstack, not permanent,
790 even though we may make them before the function turns
791 on temporary allocation. */
792 else if (code == PARM_DECL)
793 obstack = function_maybepermanent_obstack;
796 case 't': /* a type node */
797 #ifdef GATHER_STATISTICS
800 length = sizeof (struct tree_type);
801 /* All data types are put where we can preserve them if nec. */
802 if (obstack != &permanent_obstack)
803 obstack = all_types_permanent ? &permanent_obstack : saveable_obstack;
806 case 'b': /* a lexical block */
807 #ifdef GATHER_STATISTICS
810 length = sizeof (struct tree_block);
811 /* All BLOCK nodes are put where we can preserve them if nec. */
812 if (obstack != &permanent_obstack)
813 obstack = saveable_obstack;
816 case 's': /* an expression with side effects */
817 #ifdef GATHER_STATISTICS
821 case 'r': /* a reference */
822 #ifdef GATHER_STATISTICS
826 case 'e': /* an expression */
827 case '<': /* a comparison expression */
828 case '1': /* a unary arithmetic expression */
829 case '2': /* a binary arithmetic expression */
830 #ifdef GATHER_STATISTICS
834 obstack = expression_obstack;
835 /* All BIND_EXPR nodes are put where we can preserve them if nec. */
836 if (code == BIND_EXPR && obstack != &permanent_obstack)
837 obstack = saveable_obstack;
838 length = sizeof (struct tree_exp)
839 + (tree_code_length[(int) code] - 1) * sizeof (char *);
842 case 'c': /* a constant */
843 #ifdef GATHER_STATISTICS
846 obstack = expression_obstack;
847 /* We can't use tree_code_length for this, since the number of words
848 is machine-dependent due to varying alignment of `double'. */
849 if (code == REAL_CST)
851 length = sizeof (struct tree_real_cst);
855 case 'x': /* something random, like an identifier. */
856 #ifdef GATHER_STATISTICS
857 if (code == IDENTIFIER_NODE)
859 else if (code == OP_IDENTIFIER)
861 else if (code == TREE_VEC)
866 length = sizeof (struct tree_common)
867 + tree_code_length[(int) code] * sizeof (char *);
868 /* Identifier nodes are always permanent since they are
869 unique in a compiler run. */
870 if (code == IDENTIFIER_NODE) obstack = &permanent_obstack;
873 t = (tree) obstack_alloc (obstack, length);
875 #ifdef GATHER_STATISTICS
876 tree_node_counts[(int)kind]++;
877 tree_node_sizes[(int)kind] += length;
880 /* We assume here that the length of a tree node is a multiple of the
881 size of an int. Rounding up won't work because it would clobber
883 for (i = (length / sizeof (int)) - 1; i >= 0; i--)
886 TREE_SET_CODE (t, code);
887 if (obstack == &permanent_obstack)
888 TREE_PERMANENT (t) = 1;
893 TREE_SIDE_EFFECTS (t) = 1;
894 TREE_TYPE (t) = void_type_node;
898 if (code != FUNCTION_DECL)
899 DECL_IN_SYSTEM_HEADER (t)
900 = in_system_header && (obstack == &permanent_obstack);
902 DECL_SOURCE_LINE (t) = lineno;
903 DECL_SOURCE_FILE (t) = (input_filename) ? input_filename : "<built-in>";
904 DECL_UID (t) = next_decl_uid++;
909 static unsigned next_type_uid = 1;
911 TYPE_UID (t) = next_type_uid++;
914 TYPE_MAIN_VARIANT (t) = t;
918 TREE_CONSTANT (t) = 1;
925 /* Return a new node with the same contents as NODE
926 except that its TREE_CHAIN is zero and it has a fresh uid. */
933 register enum tree_code code = TREE_CODE (node);
937 switch (TREE_CODE_CLASS (code))
939 case 'd': /* A decl node */
940 length = sizeof (struct tree_decl);
943 case 't': /* a type node */
944 length = sizeof (struct tree_type);
947 case 'b': /* a lexical block node */
948 length = sizeof (struct tree_block);
951 case 'r': /* a reference */
952 case 'e': /* an expression */
953 case 's': /* an expression with side effects */
954 case '<': /* a comparison expression */
955 case '1': /* a unary arithmetic expression */
956 case '2': /* a binary arithmetic expression */
957 length = sizeof (struct tree_exp)
958 + (tree_code_length[(int) code] - 1) * sizeof (char *);
961 case 'c': /* a constant */
962 /* We can't use tree_code_length for this, since the number of words
963 is machine-dependent due to varying alignment of `double'. */
964 if (code == REAL_CST)
966 length = sizeof (struct tree_real_cst);
970 case 'x': /* something random, like an identifier. */
971 length = sizeof (struct tree_common)
972 + tree_code_length[(int) code] * sizeof (char *);
973 if (code == TREE_VEC)
974 length += (TREE_VEC_LENGTH (node) - 1) * sizeof (char *);
977 t = (tree) obstack_alloc (current_obstack, length);
979 for (i = (length / sizeof (int)) - 1; i >= 0; i--)
980 ((int *) t)[i] = ((int *) node)[i];
984 TREE_PERMANENT (t) = (current_obstack == &permanent_obstack);
989 /* Return a copy of a chain of nodes, chained through the TREE_CHAIN field.
990 For example, this can copy a list made of TREE_LIST nodes. */
997 register tree prev, next;
1002 head = prev = copy_node (list);
1003 next = TREE_CHAIN (list);
1006 TREE_CHAIN (prev) = copy_node (next);
1007 prev = TREE_CHAIN (prev);
1008 next = TREE_CHAIN (next);
1015 /* Return an IDENTIFIER_NODE whose name is TEXT (a null-terminated string).
1016 If an identifier with that name has previously been referred to,
1017 the same node is returned this time. */
1020 get_identifier (text)
1021 register char *text;
1026 register int len, hash_len;
1028 /* Compute length of text in len. */
1029 for (len = 0; text[len]; len++);
1031 /* Decide how much of that length to hash on */
1033 if (warn_id_clash && len > id_clash_len)
1034 hash_len = id_clash_len;
1036 /* Compute hash code */
1037 hi = hash_len * 613 + (unsigned)text[0];
1038 for (i = 1; i < hash_len; i += 2)
1039 hi = ((hi * 613) + (unsigned)(text[i]));
1041 hi &= (1 << HASHBITS) - 1;
1042 hi %= MAX_HASH_TABLE;
1044 /* Search table for identifier */
1045 for (idp = hash_table[hi]; idp; idp = TREE_CHAIN (idp))
1046 if (IDENTIFIER_LENGTH (idp) == len
1047 && IDENTIFIER_POINTER (idp)[0] == text[0]
1048 && !bcmp (IDENTIFIER_POINTER (idp), text, len))
1049 return idp; /* <-- return if found */
1051 /* Not found; optionally warn about a similar identifier */
1052 if (warn_id_clash && do_identifier_warnings && len >= id_clash_len)
1053 for (idp = hash_table[hi]; idp; idp = TREE_CHAIN (idp))
1054 if (!strncmp (IDENTIFIER_POINTER (idp), text, id_clash_len))
1056 warning ("`%s' and `%s' identical in first %d characters",
1057 IDENTIFIER_POINTER (idp), text, id_clash_len);
1061 if (tree_code_length[(int) IDENTIFIER_NODE] < 0)
1062 abort (); /* set_identifier_size hasn't been called. */
1064 /* Not found, create one, add to chain */
1065 idp = make_node (IDENTIFIER_NODE);
1066 IDENTIFIER_LENGTH (idp) = len;
1067 #ifdef GATHER_STATISTICS
1068 id_string_size += len;
1071 IDENTIFIER_POINTER (idp) = obstack_copy0 (&permanent_obstack, text, len);
1073 TREE_CHAIN (idp) = hash_table[hi];
1074 hash_table[hi] = idp;
1075 return idp; /* <-- return if created */
1078 /* Enable warnings on similar identifiers (if requested).
1079 Done after the built-in identifiers are created. */
1082 start_identifier_warnings ()
1084 do_identifier_warnings = 1;
1087 /* Record the size of an identifier node for the language in use.
1088 SIZE is the total size in bytes.
1089 This is called by the language-specific files. This must be
1090 called before allocating any identifiers. */
1093 set_identifier_size (size)
1096 tree_code_length[(int) IDENTIFIER_NODE]
1097 = (size - sizeof (struct tree_common)) / sizeof (tree);
1100 /* Return a newly constructed INTEGER_CST node whose constant value
1101 is specified by the two ints LOW and HI.
1102 The TREE_TYPE is set to `int'.
1104 This function should be used via the `build_int_2' macro. */
1107 build_int_2_wide (low, hi)
1108 HOST_WIDE_INT low, hi;
1110 register tree t = make_node (INTEGER_CST);
1111 TREE_INT_CST_LOW (t) = low;
1112 TREE_INT_CST_HIGH (t) = hi;
1113 TREE_TYPE (t) = integer_type_node;
1117 /* Return a new REAL_CST node whose type is TYPE and value is D. */
1120 build_real (type, d)
1126 /* Check for valid float value for this type on this target machine;
1127 if not, can print error message and store a valid value in D. */
1128 #ifdef CHECK_FLOAT_VALUE
1129 CHECK_FLOAT_VALUE (TYPE_MODE (type), d);
1132 v = make_node (REAL_CST);
1133 TREE_TYPE (v) = type;
1134 TREE_REAL_CST (v) = d;
1138 /* Return a new REAL_CST node whose type is TYPE
1139 and whose value is the integer value of the INTEGER_CST node I. */
1141 #if !defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
1144 real_value_from_int_cst (i)
1148 #ifdef REAL_ARITHMETIC
1149 REAL_VALUE_FROM_INT (d, TREE_INT_CST_LOW (i), TREE_INT_CST_HIGH (i));
1150 #else /* not REAL_ARITHMETIC */
1151 if (TREE_INT_CST_HIGH (i) < 0 && ! TREE_UNSIGNED (TREE_TYPE (i)))
1153 d = (double) (~ TREE_INT_CST_HIGH (i));
1154 d *= ((double) ((HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2))
1155 * (double) ((HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2)));
1156 d += (double) (unsigned HOST_WIDE_INT) (~ TREE_INT_CST_LOW (i));
1161 d = (double) (unsigned HOST_WIDE_INT) TREE_INT_CST_HIGH (i);
1162 d *= ((double) ((HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2))
1163 * (double) ((HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2)));
1164 d += (double) (unsigned HOST_WIDE_INT) TREE_INT_CST_LOW (i);
1166 #endif /* not REAL_ARITHMETIC */
1170 /* This function can't be implemented if we can't do arithmetic
1171 on the float representation. */
1174 build_real_from_int_cst (type, i)
1181 v = make_node (REAL_CST);
1182 TREE_TYPE (v) = type;
1184 d = REAL_VALUE_TRUNCATE (TYPE_MODE (type), real_value_from_int_cst (i));
1185 /* Check for valid float value for this type on this target machine;
1186 if not, can print error message and store a valid value in D. */
1187 #ifdef CHECK_FLOAT_VALUE
1188 CHECK_FLOAT_VALUE (TYPE_MODE (type), d);
1191 TREE_REAL_CST (v) = d;
1195 #endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */
1197 /* Return a newly constructed STRING_CST node whose value is
1198 the LEN characters at STR.
1199 The TREE_TYPE is not initialized. */
1202 build_string (len, str)
1206 register tree s = make_node (STRING_CST);
1207 TREE_STRING_LENGTH (s) = len;
1208 TREE_STRING_POINTER (s) = obstack_copy0 (saveable_obstack, str, len);
1212 /* Return a newly constructed COMPLEX_CST node whose value is
1213 specified by the real and imaginary parts REAL and IMAG.
1214 Both REAL and IMAG should be constant nodes.
1215 The TREE_TYPE is not initialized. */
1218 build_complex (real, imag)
1221 register tree t = make_node (COMPLEX_CST);
1222 TREE_REALPART (t) = real;
1223 TREE_IMAGPART (t) = imag;
1227 /* Build a newly constructed TREE_VEC node of length LEN. */
1233 register int length = (len-1) * sizeof (tree) + sizeof (struct tree_vec);
1234 register struct obstack *obstack = current_obstack;
1237 #ifdef GATHER_STATISTICS
1238 tree_node_counts[(int)vec_kind]++;
1239 tree_node_sizes[(int)vec_kind] += length;
1242 t = (tree) obstack_alloc (obstack, length);
1244 for (i = (length / sizeof (int)) - 1; i >= 0; i--)
1247 TREE_SET_CODE (t, TREE_VEC);
1248 TREE_VEC_LENGTH (t) = len;
1249 if (obstack == &permanent_obstack)
1250 TREE_PERMANENT (t) = 1;
1255 /* Return 1 if EXPR is the integer constant zero. */
1258 integer_zerop (expr)
1263 return (TREE_CODE (expr) == INTEGER_CST
1264 && TREE_INT_CST_LOW (expr) == 0
1265 && TREE_INT_CST_HIGH (expr) == 0);
1268 /* Return 1 if EXPR is the integer constant one. */
1276 return (TREE_CODE (expr) == INTEGER_CST
1277 && TREE_INT_CST_LOW (expr) == 1
1278 && TREE_INT_CST_HIGH (expr) == 0);
1281 /* Return 1 if EXPR is an integer containing all 1's
1282 in as much precision as it contains. */
1285 integer_all_onesp (expr)
1293 if (TREE_CODE (expr) != INTEGER_CST)
1296 uns = TREE_UNSIGNED (TREE_TYPE (expr));
1298 return TREE_INT_CST_LOW (expr) == -1 && TREE_INT_CST_HIGH (expr) == -1;
1300 prec = TYPE_PRECISION (TREE_TYPE (expr));
1301 if (prec >= HOST_BITS_PER_WIDE_INT)
1303 int high_value, shift_amount;
1305 shift_amount = prec - HOST_BITS_PER_WIDE_INT;
1307 if (shift_amount > HOST_BITS_PER_WIDE_INT)
1308 /* Can not handle precisions greater than twice the host int size. */
1310 else if (shift_amount == HOST_BITS_PER_WIDE_INT)
1311 /* Shifting by the host word size is undefined according to the ANSI
1312 standard, so we must handle this as a special case. */
1315 high_value = ((HOST_WIDE_INT) 1 << shift_amount) - 1;
1317 return TREE_INT_CST_LOW (expr) == -1
1318 && TREE_INT_CST_HIGH (expr) == high_value;
1321 return TREE_INT_CST_LOW (expr) == ((HOST_WIDE_INT) 1 << prec) - 1;
1324 /* Return 1 if EXPR is an integer constant that is a power of 2 (i.e., has only
1328 integer_pow2p (expr)
1331 HOST_WIDE_INT high, low;
1335 if (TREE_CODE (expr) != INTEGER_CST)
1338 high = TREE_INT_CST_HIGH (expr);
1339 low = TREE_INT_CST_LOW (expr);
1341 if (high == 0 && low == 0)
1344 return ((high == 0 && (low & (low - 1)) == 0)
1345 || (low == 0 && (high & (high - 1)) == 0));
1348 /* Return 1 if EXPR is the real constant zero. */
1356 return (TREE_CODE (expr) == REAL_CST
1357 && REAL_VALUES_EQUAL (TREE_REAL_CST (expr), dconst0));
1360 /* Return 1 if EXPR is the real constant one. */
1368 return (TREE_CODE (expr) == REAL_CST
1369 && REAL_VALUES_EQUAL (TREE_REAL_CST (expr), dconst1));
1372 /* Return 1 if EXPR is the real constant two. */
1380 return (TREE_CODE (expr) == REAL_CST
1381 && REAL_VALUES_EQUAL (TREE_REAL_CST (expr), dconst2));
1384 /* Nonzero if EXP is a constant or a cast of a constant. */
1387 really_constant_p (exp)
1390 /* This is not quite the same as STRIP_NOPS. It does more. */
1391 while (TREE_CODE (exp) == NOP_EXPR
1392 || TREE_CODE (exp) == CONVERT_EXPR
1393 || TREE_CODE (exp) == NON_LVALUE_EXPR)
1394 exp = TREE_OPERAND (exp, 0);
1395 return TREE_CONSTANT (exp);
1398 /* Return first list element whose TREE_VALUE is ELEM.
1399 Return 0 if ELEM is not it LIST. */
1402 value_member (elem, list)
1407 if (elem == TREE_VALUE (list))
1409 list = TREE_CHAIN (list);
1414 /* Return first list element whose TREE_PURPOSE is ELEM.
1415 Return 0 if ELEM is not it LIST. */
1418 purpose_member (elem, list)
1423 if (elem == TREE_PURPOSE (list))
1425 list = TREE_CHAIN (list);
1430 /* Return first list element whose BINFO_TYPE is ELEM.
1431 Return 0 if ELEM is not it LIST. */
1434 binfo_member (elem, list)
1439 if (elem == BINFO_TYPE (list))
1441 list = TREE_CHAIN (list);
1446 /* Return nonzero if ELEM is part of the chain CHAIN. */
1449 chain_member (elem, chain)
1456 chain = TREE_CHAIN (chain);
1462 /* Return the length of a chain of nodes chained through TREE_CHAIN.
1463 We expect a null pointer to mark the end of the chain.
1464 This is the Lisp primitive `length'. */
1471 register int len = 0;
1473 for (tail = t; tail; tail = TREE_CHAIN (tail))
1479 /* Concatenate two chains of nodes (chained through TREE_CHAIN)
1480 by modifying the last node in chain 1 to point to chain 2.
1481 This is the Lisp primitive `nconc'. */
1491 for (t = op1; TREE_CHAIN (t); t = TREE_CHAIN (t))
1492 if (t == op2) abort (); /* Circularity being created */
1493 if (t == op2) abort (); /* Circularity being created */
1494 TREE_CHAIN (t) = op2;
1500 /* Return the last node in a chain of nodes (chained through TREE_CHAIN). */
1504 register tree chain;
1508 while (next = TREE_CHAIN (chain))
1513 /* Reverse the order of elements in the chain T,
1514 and return the new head of the chain (old last element). */
1520 register tree prev = 0, decl, next;
1521 for (decl = t; decl; decl = next)
1523 next = TREE_CHAIN (decl);
1524 TREE_CHAIN (decl) = prev;
1530 /* Given a chain CHAIN of tree nodes,
1531 construct and return a list of those nodes. */
1537 tree result = NULL_TREE;
1538 tree in_tail = chain;
1539 tree out_tail = NULL_TREE;
1543 tree next = tree_cons (NULL_TREE, in_tail, NULL_TREE);
1545 TREE_CHAIN (out_tail) = next;
1549 in_tail = TREE_CHAIN (in_tail);
1555 /* Return a newly created TREE_LIST node whose
1556 purpose and value fields are PARM and VALUE. */
1559 build_tree_list (parm, value)
1562 register tree t = make_node (TREE_LIST);
1563 TREE_PURPOSE (t) = parm;
1564 TREE_VALUE (t) = value;
1568 /* Similar, but build on the temp_decl_obstack. */
1571 build_decl_list (parm, value)
1575 register struct obstack *ambient_obstack = current_obstack;
1576 current_obstack = &temp_decl_obstack;
1577 node = build_tree_list (parm, value);
1578 current_obstack = ambient_obstack;
1582 /* Return a newly created TREE_LIST node whose
1583 purpose and value fields are PARM and VALUE
1584 and whose TREE_CHAIN is CHAIN. */
1587 tree_cons (purpose, value, chain)
1588 tree purpose, value, chain;
1591 register tree node = make_node (TREE_LIST);
1594 register tree node = (tree) obstack_alloc (current_obstack, sizeof (struct tree_list));
1595 #ifdef GATHER_STATISTICS
1596 tree_node_counts[(int)x_kind]++;
1597 tree_node_sizes[(int)x_kind] += sizeof (struct tree_list);
1600 for (i = (sizeof (struct tree_common) / sizeof (int)) - 1; i >= 0; i--)
1601 ((int *) node)[i] = 0;
1603 TREE_SET_CODE (node, TREE_LIST);
1604 if (current_obstack == &permanent_obstack)
1605 TREE_PERMANENT (node) = 1;
1608 TREE_CHAIN (node) = chain;
1609 TREE_PURPOSE (node) = purpose;
1610 TREE_VALUE (node) = value;
1614 /* Similar, but build on the temp_decl_obstack. */
1617 decl_tree_cons (purpose, value, chain)
1618 tree purpose, value, chain;
1621 register struct obstack *ambient_obstack = current_obstack;
1622 current_obstack = &temp_decl_obstack;
1623 node = tree_cons (purpose, value, chain);
1624 current_obstack = ambient_obstack;
1628 /* Same as `tree_cons' but make a permanent object. */
1631 perm_tree_cons (purpose, value, chain)
1632 tree purpose, value, chain;
1635 register struct obstack *ambient_obstack = current_obstack;
1636 current_obstack = &permanent_obstack;
1638 node = tree_cons (purpose, value, chain);
1639 current_obstack = ambient_obstack;
1643 /* Same as `tree_cons', but make this node temporary, regardless. */
1646 temp_tree_cons (purpose, value, chain)
1647 tree purpose, value, chain;
1650 register struct obstack *ambient_obstack = current_obstack;
1651 current_obstack = &temporary_obstack;
1653 node = tree_cons (purpose, value, chain);
1654 current_obstack = ambient_obstack;
1658 /* Same as `tree_cons', but save this node if the function's RTL is saved. */
1661 saveable_tree_cons (purpose, value, chain)
1662 tree purpose, value, chain;
1665 register struct obstack *ambient_obstack = current_obstack;
1666 current_obstack = saveable_obstack;
1668 node = tree_cons (purpose, value, chain);
1669 current_obstack = ambient_obstack;
1673 /* Return the size nominally occupied by an object of type TYPE
1674 when it resides in memory. The value is measured in units of bytes,
1675 and its data type is that normally used for type sizes
1676 (which is the first type created by make_signed_type or
1677 make_unsigned_type). */
1680 size_in_bytes (type)
1683 if (type == error_mark_node)
1684 return integer_zero_node;
1685 type = TYPE_MAIN_VARIANT (type);
1686 if (TYPE_SIZE (type) == 0)
1688 incomplete_type_error (NULL_TREE, type);
1689 return integer_zero_node;
1691 return size_binop (CEIL_DIV_EXPR, TYPE_SIZE (type),
1692 size_int (BITS_PER_UNIT));
1695 /* Return the size of TYPE (in bytes) as an integer,
1696 or return -1 if the size can vary. */
1699 int_size_in_bytes (type)
1703 if (type == error_mark_node)
1705 type = TYPE_MAIN_VARIANT (type);
1706 if (TYPE_SIZE (type) == 0)
1708 if (TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST)
1710 size = TREE_INT_CST_LOW (TYPE_SIZE (type));
1711 return (size + BITS_PER_UNIT - 1) / BITS_PER_UNIT;
1714 /* Return, as an INTEGER_CST node, the number of elements for
1715 TYPE (which is an ARRAY_TYPE) minus one.
1716 This counts only elements of the top array. */
1719 array_type_nelts (type)
1722 tree index_type = TYPE_DOMAIN (type);
1723 return (tree_int_cst_equal (TYPE_MIN_VALUE (index_type), integer_zero_node)
1724 ? TYPE_MAX_VALUE (index_type)
1725 : fold (build (MINUS_EXPR, integer_type_node,
1726 TYPE_MAX_VALUE (index_type),
1727 TYPE_MIN_VALUE (index_type))));
1730 /* Return nonzero if arg is static -- a reference to an object in
1731 static storage. This is not the same as the C meaning of `static'. */
1737 switch (TREE_CODE (arg))
1742 return TREE_STATIC (arg) || DECL_EXTERNAL (arg);
1749 return staticp (TREE_OPERAND (arg, 0));
1752 return TREE_CONSTANT (TREE_OPERAND (arg, 0));
1755 if (TREE_CODE (TYPE_SIZE (TREE_TYPE (arg))) == INTEGER_CST
1756 && TREE_CODE (TREE_OPERAND (arg, 1)) == INTEGER_CST)
1757 return staticp (TREE_OPERAND (arg, 0));
1763 /* This should be applied to any node which may be used in more than one place,
1764 but must be evaluated only once. Normally, the code generator would
1765 reevaluate the node each time; this forces it to compute it once and save
1766 the result. This is done by encapsulating the node in a SAVE_EXPR. */
1772 register tree t = fold (expr);
1774 /* We don't care about whether this can be used as an lvalue in this
1776 while (TREE_CODE (t) == NON_LVALUE_EXPR)
1777 t = TREE_OPERAND (t, 0);
1779 /* If the tree evaluates to a constant, then we don't want to hide that
1780 fact (i.e. this allows further folding, and direct checks for constants).
1781 However, a read-only object that has side effects cannot be bypassed.
1782 Since it is no problem to reevaluate literals, we just return the
1785 if (TREE_CONSTANT (t) || (TREE_READONLY (t) && ! TREE_SIDE_EFFECTS (t))
1786 || TREE_CODE (t) == SAVE_EXPR)
1789 t = build (SAVE_EXPR, TREE_TYPE (expr), t, current_function_decl, NULL_TREE);
1791 /* This expression might be placed ahead of a jump to ensure that the
1792 value was computed on both sides of the jump. So make sure it isn't
1793 eliminated as dead. */
1794 TREE_SIDE_EFFECTS (t) = 1;
1798 /* Stabilize a reference so that we can use it any number of times
1799 without causing its operands to be evaluated more than once.
1800 Returns the stabilized reference.
1802 Also allows conversion expressions whose operands are references.
1803 Any other kind of expression is returned unchanged. */
1806 stabilize_reference (ref)
1809 register tree result;
1810 register enum tree_code code = TREE_CODE (ref);
1817 /* No action is needed in this case. */
1823 case FIX_TRUNC_EXPR:
1824 case FIX_FLOOR_EXPR:
1825 case FIX_ROUND_EXPR:
1827 result = build_nt (code, stabilize_reference (TREE_OPERAND (ref, 0)));
1831 result = build_nt (INDIRECT_REF,
1832 stabilize_reference_1 (TREE_OPERAND (ref, 0)));
1836 result = build_nt (COMPONENT_REF,
1837 stabilize_reference (TREE_OPERAND (ref, 0)),
1838 TREE_OPERAND (ref, 1));
1842 result = build_nt (BIT_FIELD_REF,
1843 stabilize_reference (TREE_OPERAND (ref, 0)),
1844 stabilize_reference_1 (TREE_OPERAND (ref, 1)),
1845 stabilize_reference_1 (TREE_OPERAND (ref, 2)));
1849 result = build_nt (ARRAY_REF,
1850 stabilize_reference (TREE_OPERAND (ref, 0)),
1851 stabilize_reference_1 (TREE_OPERAND (ref, 1)));
1854 /* If arg isn't a kind of lvalue we recognize, make no change.
1855 Caller should recognize the error for an invalid lvalue. */
1860 return error_mark_node;
1863 TREE_TYPE (result) = TREE_TYPE (ref);
1864 TREE_READONLY (result) = TREE_READONLY (ref);
1865 TREE_SIDE_EFFECTS (result) = TREE_SIDE_EFFECTS (ref);
1866 TREE_THIS_VOLATILE (result) = TREE_THIS_VOLATILE (ref);
1867 TREE_RAISES (result) = TREE_RAISES (ref);
1872 /* Subroutine of stabilize_reference; this is called for subtrees of
1873 references. Any expression with side-effects must be put in a SAVE_EXPR
1874 to ensure that it is only evaluated once.
1876 We don't put SAVE_EXPR nodes around everything, because assigning very
1877 simple expressions to temporaries causes us to miss good opportunities
1878 for optimizations. Among other things, the opportunity to fold in the
1879 addition of a constant into an addressing mode often gets lost, e.g.
1880 "y[i+1] += x;". In general, we take the approach that we should not make
1881 an assignment unless we are forced into it - i.e., that any non-side effect
1882 operator should be allowed, and that cse should take care of coalescing
1883 multiple utterances of the same expression should that prove fruitful. */
1886 stabilize_reference_1 (e)
1889 register tree result;
1890 register int length;
1891 register enum tree_code code = TREE_CODE (e);
1893 /* We cannot ignore const expressions because it might be a reference
1894 to a const array but whose index contains side-effects. But we can
1895 ignore things that are actual constant or that already have been
1896 handled by this function. */
1898 if (TREE_CONSTANT (e) || code == SAVE_EXPR)
1901 switch (TREE_CODE_CLASS (code))
1911 /* If the expression has side-effects, then encase it in a SAVE_EXPR
1912 so that it will only be evaluated once. */
1913 /* The reference (r) and comparison (<) classes could be handled as
1914 below, but it is generally faster to only evaluate them once. */
1915 if (TREE_SIDE_EFFECTS (e))
1916 return save_expr (e);
1920 /* Constants need no processing. In fact, we should never reach
1925 /* Recursively stabilize each operand. */
1926 result = build_nt (code, stabilize_reference_1 (TREE_OPERAND (e, 0)),
1927 stabilize_reference_1 (TREE_OPERAND (e, 1)));
1931 /* Recursively stabilize each operand. */
1932 result = build_nt (code, stabilize_reference_1 (TREE_OPERAND (e, 0)));
1936 TREE_TYPE (result) = TREE_TYPE (e);
1937 TREE_READONLY (result) = TREE_READONLY (e);
1938 TREE_SIDE_EFFECTS (result) = TREE_SIDE_EFFECTS (e);
1939 TREE_THIS_VOLATILE (result) = TREE_THIS_VOLATILE (e);
1940 TREE_RAISES (result) = TREE_RAISES (e);
1945 /* Low-level constructors for expressions. */
1947 /* Build an expression of code CODE, data type TYPE,
1948 and operands as specified by the arguments ARG1 and following arguments.
1949 Expressions and reference nodes can be created this way.
1950 Constants, decls, types and misc nodes cannot be. */
1957 enum tree_code code;
1959 register int length;
1964 code = va_arg (p, enum tree_code);
1965 t = make_node (code);
1966 length = tree_code_length[(int) code];
1967 TREE_TYPE (t) = va_arg (p, tree);
1971 /* This is equivalent to the loop below, but faster. */
1972 register tree arg0 = va_arg (p, tree);
1973 register tree arg1 = va_arg (p, tree);
1974 TREE_OPERAND (t, 0) = arg0;
1975 TREE_OPERAND (t, 1) = arg1;
1976 if ((arg0 && TREE_SIDE_EFFECTS (arg0))
1977 || (arg1 && TREE_SIDE_EFFECTS (arg1)))
1978 TREE_SIDE_EFFECTS (t) = 1;
1980 = (arg0 && TREE_RAISES (arg0)) || (arg1 && TREE_RAISES (arg1));
1982 else if (length == 1)
1984 register tree arg0 = va_arg (p, tree);
1986 /* Call build1 for this! */
1987 if (TREE_CODE_CLASS (code) != 's')
1989 TREE_OPERAND (t, 0) = arg0;
1990 if (arg0 && TREE_SIDE_EFFECTS (arg0))
1991 TREE_SIDE_EFFECTS (t) = 1;
1992 TREE_RAISES (t) = (arg0 && TREE_RAISES (arg0));
1996 for (i = 0; i < length; i++)
1998 register tree operand = va_arg (p, tree);
1999 TREE_OPERAND (t, i) = operand;
2002 if (TREE_SIDE_EFFECTS (operand))
2003 TREE_SIDE_EFFECTS (t) = 1;
2004 if (TREE_RAISES (operand))
2005 TREE_RAISES (t) = 1;
2013 /* Same as above, but only builds for unary operators.
2014 Saves lions share of calls to `build'; cuts down use
2015 of varargs, which is expensive for RISC machines. */
2017 build1 (code, type, node)
2018 enum tree_code code;
2022 register struct obstack *obstack = current_obstack;
2023 register int i, length;
2024 register tree_node_kind kind;
2027 #ifdef GATHER_STATISTICS
2028 if (TREE_CODE_CLASS (code) == 'r')
2034 obstack = expression_obstack;
2035 length = sizeof (struct tree_exp);
2037 t = (tree) obstack_alloc (obstack, length);
2039 #ifdef GATHER_STATISTICS
2040 tree_node_counts[(int)kind]++;
2041 tree_node_sizes[(int)kind] += length;
2044 for (i = (length / sizeof (int)) - 1; i >= 0; i--)
2047 TREE_TYPE (t) = type;
2048 TREE_SET_CODE (t, code);
2050 if (obstack == &permanent_obstack)
2051 TREE_PERMANENT (t) = 1;
2053 TREE_OPERAND (t, 0) = node;
2056 if (TREE_SIDE_EFFECTS (node))
2057 TREE_SIDE_EFFECTS (t) = 1;
2058 if (TREE_RAISES (node))
2059 TREE_RAISES (t) = 1;
2065 /* Similar except don't specify the TREE_TYPE
2066 and leave the TREE_SIDE_EFFECTS as 0.
2067 It is permissible for arguments to be null,
2068 or even garbage if their values do not matter. */
2075 register enum tree_code code;
2077 register int length;
2082 code = va_arg (p, enum tree_code);
2083 t = make_node (code);
2084 length = tree_code_length[(int) code];
2086 for (i = 0; i < length; i++)
2087 TREE_OPERAND (t, i) = va_arg (p, tree);
2093 /* Similar to `build_nt', except we build
2094 on the temp_decl_obstack, regardless. */
2097 build_parse_node (va_alist)
2100 register struct obstack *ambient_obstack = expression_obstack;
2102 register enum tree_code code;
2104 register int length;
2107 expression_obstack = &temp_decl_obstack;
2111 code = va_arg (p, enum tree_code);
2112 t = make_node (code);
2113 length = tree_code_length[(int) code];
2115 for (i = 0; i < length; i++)
2116 TREE_OPERAND (t, i) = va_arg (p, tree);
2119 expression_obstack = ambient_obstack;
2124 /* Commented out because this wants to be done very
2125 differently. See cp-lex.c. */
2127 build_op_identifier (op1, op2)
2130 register tree t = make_node (OP_IDENTIFIER);
2131 TREE_PURPOSE (t) = op1;
2132 TREE_VALUE (t) = op2;
2137 /* Create a DECL_... node of code CODE, name NAME and data type TYPE.
2138 We do NOT enter this node in any sort of symbol table.
2140 layout_decl is used to set up the decl's storage layout.
2141 Other slots are initialized to 0 or null pointers. */
2144 build_decl (code, name, type)
2145 enum tree_code code;
2150 t = make_node (code);
2152 /* if (type == error_mark_node)
2153 type = integer_type_node; */
2154 /* That is not done, deliberately, so that having error_mark_node
2155 as the type can suppress useless errors in the use of this variable. */
2157 DECL_NAME (t) = name;
2158 DECL_ASSEMBLER_NAME (t) = name;
2159 TREE_TYPE (t) = type;
2161 if (code == VAR_DECL || code == PARM_DECL || code == RESULT_DECL)
2163 else if (code == FUNCTION_DECL)
2164 DECL_MODE (t) = FUNCTION_MODE;
2169 /* BLOCK nodes are used to represent the structure of binding contours
2170 and declarations, once those contours have been exited and their contents
2171 compiled. This information is used for outputting debugging info. */
2174 build_block (vars, tags, subblocks, supercontext, chain)
2175 tree vars, tags, subblocks, supercontext, chain;
2177 register tree block = make_node (BLOCK);
2178 BLOCK_VARS (block) = vars;
2179 BLOCK_TYPE_TAGS (block) = tags;
2180 BLOCK_SUBBLOCKS (block) = subblocks;
2181 BLOCK_SUPERCONTEXT (block) = supercontext;
2182 BLOCK_CHAIN (block) = chain;
2186 /* Return a type like TYPE except that its TYPE_READONLY is CONSTP
2187 and its TYPE_VOLATILE is VOLATILEP.
2189 Such variant types already made are recorded so that duplicates
2192 A variant types should never be used as the type of an expression.
2193 Always copy the variant information into the TREE_READONLY
2194 and TREE_THIS_VOLATILE of the expression, and then give the expression
2195 as its type the "main variant", the variant whose TYPE_READONLY
2196 and TYPE_VOLATILE are zero. Use TYPE_MAIN_VARIANT to find the
2200 build_type_variant (type, constp, volatilep)
2202 int constp, volatilep;
2204 register tree t, m = TYPE_MAIN_VARIANT (type);
2205 register struct obstack *ambient_obstack = current_obstack;
2207 /* Treat any nonzero argument as 1. */
2209 volatilep = !!volatilep;
2211 /* If not generating auxiliary info, search the chain of variants to see
2212 if there is already one there just like the one we need to have. If so,
2213 use that existing one.
2215 We don't do this in the case where we are generating aux info because
2216 in that case we want each typedef names to get it's own distinct type
2217 node, even if the type of this new typedef is the same as some other
2220 if (!flag_gen_aux_info)
2221 for (t = m; t; t = TYPE_NEXT_VARIANT (t))
2222 if (constp == TYPE_READONLY (t) && volatilep == TYPE_VOLATILE (t))
2225 /* We need a new one. */
2227 = TREE_PERMANENT (type) ? &permanent_obstack : saveable_obstack;
2229 t = copy_node (type);
2230 TYPE_READONLY (t) = constp;
2231 TYPE_VOLATILE (t) = volatilep;
2232 TYPE_POINTER_TO (t) = 0;
2233 TYPE_REFERENCE_TO (t) = 0;
2235 /* Add this type to the chain of variants of TYPE. */
2236 TYPE_NEXT_VARIANT (t) = TYPE_NEXT_VARIANT (m);
2237 TYPE_NEXT_VARIANT (m) = t;
2239 current_obstack = ambient_obstack;
2243 /* Create a new variant of TYPE, equivalent but distinct.
2244 This is so the caller can modify it. */
2247 build_type_copy (type)
2250 register tree t, m = TYPE_MAIN_VARIANT (type);
2251 register struct obstack *ambient_obstack = current_obstack;
2254 = TREE_PERMANENT (type) ? &permanent_obstack : saveable_obstack;
2256 t = copy_node (type);
2257 TYPE_POINTER_TO (t) = 0;
2258 TYPE_REFERENCE_TO (t) = 0;
2260 /* Add this type to the chain of variants of TYPE. */
2261 TYPE_NEXT_VARIANT (t) = TYPE_NEXT_VARIANT (m);
2262 TYPE_NEXT_VARIANT (m) = t;
2264 current_obstack = ambient_obstack;
2268 /* Hashing of types so that we don't make duplicates.
2269 The entry point is `type_hash_canon'. */
2271 /* Each hash table slot is a bucket containing a chain
2272 of these structures. */
2276 struct type_hash *next; /* Next structure in the bucket. */
2277 int hashcode; /* Hash code of this type. */
2278 tree type; /* The type recorded here. */
2281 /* Now here is the hash table. When recording a type, it is added
2282 to the slot whose index is the hash code mod the table size.
2283 Note that the hash table is used for several kinds of types
2284 (function types, array types and array index range types, for now).
2285 While all these live in the same table, they are completely independent,
2286 and the hash code is computed differently for each of these. */
2288 #define TYPE_HASH_SIZE 59
2289 struct type_hash *type_hash_table[TYPE_HASH_SIZE];
2291 /* Here is how primitive or already-canonicalized types' hash
2293 #define TYPE_HASH(TYPE) ((HOST_WIDE_INT) (TYPE) & 0777777)
2295 /* Compute a hash code for a list of types (chain of TREE_LIST nodes
2296 with types in the TREE_VALUE slots), by adding the hash codes
2297 of the individual types. */
2300 type_hash_list (list)
2303 register int hashcode;
2305 for (hashcode = 0, tail = list; tail; tail = TREE_CHAIN (tail))
2306 hashcode += TYPE_HASH (TREE_VALUE (tail));
2310 /* Look in the type hash table for a type isomorphic to TYPE.
2311 If one is found, return it. Otherwise return 0. */
2314 type_hash_lookup (hashcode, type)
2318 register struct type_hash *h;
2319 for (h = type_hash_table[hashcode % TYPE_HASH_SIZE]; h; h = h->next)
2320 if (h->hashcode == hashcode
2321 && TREE_CODE (h->type) == TREE_CODE (type)
2322 && TREE_TYPE (h->type) == TREE_TYPE (type)
2323 && (TYPE_MAX_VALUE (h->type) == TYPE_MAX_VALUE (type)
2324 || tree_int_cst_equal (TYPE_MAX_VALUE (h->type),
2325 TYPE_MAX_VALUE (type)))
2326 && (TYPE_MIN_VALUE (h->type) == TYPE_MIN_VALUE (type)
2327 || tree_int_cst_equal (TYPE_MIN_VALUE (h->type),
2328 TYPE_MIN_VALUE (type)))
2329 && (TYPE_DOMAIN (h->type) == TYPE_DOMAIN (type)
2330 || (TYPE_DOMAIN (h->type)
2331 && TREE_CODE (TYPE_DOMAIN (h->type)) == TREE_LIST
2332 && TYPE_DOMAIN (type)
2333 && TREE_CODE (TYPE_DOMAIN (type)) == TREE_LIST
2334 && type_list_equal (TYPE_DOMAIN (h->type), TYPE_DOMAIN (type)))))
2339 /* Add an entry to the type-hash-table
2340 for a type TYPE whose hash code is HASHCODE. */
2343 type_hash_add (hashcode, type)
2347 register struct type_hash *h;
2349 h = (struct type_hash *) oballoc (sizeof (struct type_hash));
2350 h->hashcode = hashcode;
2352 h->next = type_hash_table[hashcode % TYPE_HASH_SIZE];
2353 type_hash_table[hashcode % TYPE_HASH_SIZE] = h;
2356 /* Given TYPE, and HASHCODE its hash code, return the canonical
2357 object for an identical type if one already exists.
2358 Otherwise, return TYPE, and record it as the canonical object
2359 if it is a permanent object.
2361 To use this function, first create a type of the sort you want.
2362 Then compute its hash code from the fields of the type that
2363 make it different from other similar types.
2364 Then call this function and use the value.
2365 This function frees the type you pass in if it is a duplicate. */
2367 /* Set to 1 to debug without canonicalization. Never set by program. */
2368 int debug_no_type_hash = 0;
2371 type_hash_canon (hashcode, type)
2377 if (debug_no_type_hash)
2380 t1 = type_hash_lookup (hashcode, type);
2384 = TREE_PERMANENT (type) ? &permanent_obstack : saveable_obstack;
2385 obstack_free (o, type);
2386 #ifdef GATHER_STATISTICS
2387 tree_node_counts[(int)t_kind]--;
2388 tree_node_sizes[(int)t_kind] -= sizeof (struct tree_type);
2393 /* If this is a new type, record it for later reuse. */
2394 if (current_obstack == &permanent_obstack)
2395 type_hash_add (hashcode, type);
2400 /* Given two lists of types
2401 (chains of TREE_LIST nodes with types in the TREE_VALUE slots)
2402 return 1 if the lists contain the same types in the same order.
2403 Also, the TREE_PURPOSEs must match. */
2406 type_list_equal (l1, l2)
2409 register tree t1, t2;
2410 for (t1 = l1, t2 = l2; t1 && t2; t1 = TREE_CHAIN (t1), t2 = TREE_CHAIN (t2))
2412 if (TREE_VALUE (t1) != TREE_VALUE (t2))
2414 if (TREE_PURPOSE (t1) != TREE_PURPOSE (t2))
2416 int cmp = simple_cst_equal (TREE_PURPOSE (t1), TREE_PURPOSE (t2));
2427 /* Nonzero if integer constants T1 and T2
2428 represent the same constant value. */
2431 tree_int_cst_equal (t1, t2)
2436 if (t1 == 0 || t2 == 0)
2438 if (TREE_CODE (t1) == INTEGER_CST
2439 && TREE_CODE (t2) == INTEGER_CST
2440 && TREE_INT_CST_LOW (t1) == TREE_INT_CST_LOW (t2)
2441 && TREE_INT_CST_HIGH (t1) == TREE_INT_CST_HIGH (t2))
2446 /* Nonzero if integer constants T1 and T2 represent values that satisfy <.
2447 The precise way of comparison depends on their data type. */
2450 tree_int_cst_lt (t1, t2)
2456 if (!TREE_UNSIGNED (TREE_TYPE (t1)))
2457 return INT_CST_LT (t1, t2);
2458 return INT_CST_LT_UNSIGNED (t1, t2);
2461 /* Compare two constructor-element-type constants. */
2463 simple_cst_list_equal (l1, l2)
2466 while (l1 != NULL_TREE && l2 != NULL_TREE)
2468 int cmp = simple_cst_equal (TREE_VALUE (l1), TREE_VALUE (l2));
2473 l1 = TREE_CHAIN (l1);
2474 l2 = TREE_CHAIN (l2);
2479 /* Return truthvalue of whether T1 is the same tree structure as T2.
2480 Return 1 if they are the same.
2481 Return 0 if they are understandably different.
2482 Return -1 if either contains tree structure not understood by
2486 simple_cst_equal (t1, t2)
2489 register enum tree_code code1, code2;
2494 if (t1 == 0 || t2 == 0)
2497 code1 = TREE_CODE (t1);
2498 code2 = TREE_CODE (t2);
2500 if (code1 == NOP_EXPR || code1 == CONVERT_EXPR || code1 == NON_LVALUE_EXPR)
2501 if (code2 == NOP_EXPR || code2 == CONVERT_EXPR || code2 == NON_LVALUE_EXPR)
2502 return simple_cst_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
2504 return simple_cst_equal (TREE_OPERAND (t1, 0), t2);
2505 else if (code2 == NOP_EXPR || code2 == CONVERT_EXPR
2506 || code2 == NON_LVALUE_EXPR)
2507 return simple_cst_equal (t1, TREE_OPERAND (t2, 0));
2515 return TREE_INT_CST_LOW (t1) == TREE_INT_CST_LOW (t2)
2516 && TREE_INT_CST_HIGH (t1) == TREE_INT_CST_HIGH (t2);
2519 return REAL_VALUES_EQUAL (TREE_REAL_CST (t1), TREE_REAL_CST (t2));
2522 return TREE_STRING_LENGTH (t1) == TREE_STRING_LENGTH (t2)
2523 && !bcmp (TREE_STRING_POINTER (t1), TREE_STRING_POINTER (t2),
2524 TREE_STRING_LENGTH (t1));
2530 return simple_cst_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
2533 cmp = simple_cst_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
2536 return simple_cst_list_equal (TREE_OPERAND (t1, 1), TREE_OPERAND (t2, 1));
2539 /* Special case: if either target is an unallocated VAR_DECL,
2540 it means that it's going to be unified with whatever the
2541 TARGET_EXPR is really supposed to initialize, so treat it
2542 as being equivalent to anything. */
2543 if ((TREE_CODE (TREE_OPERAND (t1, 0)) == VAR_DECL
2544 && DECL_NAME (TREE_OPERAND (t1, 0)) == NULL_TREE
2545 && DECL_RTL (TREE_OPERAND (t1, 0)) == 0)
2546 || (TREE_CODE (TREE_OPERAND (t2, 0)) == VAR_DECL
2547 && DECL_NAME (TREE_OPERAND (t2, 0)) == NULL_TREE
2548 && DECL_RTL (TREE_OPERAND (t2, 0)) == 0))
2551 cmp = simple_cst_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
2554 return simple_cst_equal (TREE_OPERAND (t1, 1), TREE_OPERAND (t2, 1));
2556 case WITH_CLEANUP_EXPR:
2557 cmp = simple_cst_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
2560 return simple_cst_equal (TREE_OPERAND (t1, 2), TREE_OPERAND (t1, 2));
2563 if (TREE_OPERAND (t1, 1) == TREE_OPERAND (t2, 1))
2564 return simple_cst_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
2568 return (simple_cst_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0))
2569 && simple_cst_equal (TREE_OPERAND (t1, 1), TREE_OPERAND (t2, 1))
2570 && simple_cst_equal (TREE_OPERAND (t1, 2), TREE_OPERAND (t2, 2)));
2581 case TRUNC_DIV_EXPR:
2582 case TRUNC_MOD_EXPR:
2585 cmp = simple_cst_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
2588 return simple_cst_equal (TREE_OPERAND (t1, 1), TREE_OPERAND (t2, 1));
2592 case REFERENCE_EXPR:
2594 return simple_cst_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
2598 return lang_simple_cst_equal (t1, t2);
2605 /* Constructors for pointer, array and function types.
2606 (RECORD_TYPE, UNION_TYPE and ENUMERAL_TYPE nodes are
2607 constructed by language-dependent code, not here.) */
2609 /* Construct, lay out and return the type of pointers to TO_TYPE.
2610 If such a type has already been constructed, reuse it. */
2613 build_pointer_type (to_type)
2616 register tree t = TYPE_POINTER_TO (to_type);
2617 register struct obstack *ambient_obstack = current_obstack;
2618 register struct obstack *ambient_saveable_obstack = saveable_obstack;
2620 /* First, if we already have a type for pointers to TO_TYPE, use it. */
2625 /* We need a new one. If TO_TYPE is permanent, make this permanent too. */
2626 if (TREE_PERMANENT (to_type))
2628 current_obstack = &permanent_obstack;
2629 saveable_obstack = &permanent_obstack;
2632 t = make_node (POINTER_TYPE);
2633 TREE_TYPE (t) = to_type;
2635 /* Record this type as the pointer to TO_TYPE. */
2636 TYPE_POINTER_TO (to_type) = t;
2638 /* Lay out the type. This function has many callers that are concerned
2639 with expression-construction, and this simplifies them all.
2640 Also, it guarantees the TYPE_SIZE is permanent if the type is. */
2643 current_obstack = ambient_obstack;
2644 saveable_obstack = ambient_saveable_obstack;
2648 /* Create a type of integers to be the TYPE_DOMAIN of an ARRAY_TYPE.
2649 MAXVAL should be the maximum value in the domain
2650 (one less than the length of the array). */
2653 build_index_type (maxval)
2656 register tree itype = make_node (INTEGER_TYPE);
2657 TYPE_PRECISION (itype) = TYPE_PRECISION (sizetype);
2658 TYPE_MIN_VALUE (itype) = build_int_2 (0, 0);
2659 TREE_TYPE (TYPE_MIN_VALUE (itype)) = sizetype;
2660 TYPE_MAX_VALUE (itype) = convert (sizetype, maxval);
2661 TYPE_MODE (itype) = TYPE_MODE (sizetype);
2662 TYPE_SIZE (itype) = TYPE_SIZE (sizetype);
2663 TYPE_ALIGN (itype) = TYPE_ALIGN (sizetype);
2664 if (TREE_CODE (maxval) == INTEGER_CST)
2666 HOST_WIDE_INT maxint = TREE_INT_CST_LOW (maxval);
2667 return type_hash_canon (maxint > 0 ? maxint : - maxint, itype);
2673 /* Just like build_index_type, but takes lowval and highval instead
2674 of just highval (maxval). */
2677 build_index_2_type (lowval,highval)
2678 tree lowval, highval;
2680 register tree itype = make_node (INTEGER_TYPE);
2681 TYPE_PRECISION (itype) = TYPE_PRECISION (sizetype);
2682 TYPE_MIN_VALUE (itype) = convert (sizetype, lowval);
2683 TYPE_MAX_VALUE (itype) = convert (sizetype, highval);
2684 TYPE_MODE (itype) = TYPE_MODE (sizetype);
2685 TYPE_SIZE (itype) = TYPE_SIZE (sizetype);
2686 TYPE_ALIGN (itype) = TYPE_ALIGN (sizetype);
2687 if ((TREE_CODE (lowval) == INTEGER_CST)
2688 && (TREE_CODE (highval) == INTEGER_CST))
2690 HOST_WIDE_INT highint = TREE_INT_CST_LOW (highval);
2691 HOST_WIDE_INT lowint = TREE_INT_CST_LOW (lowval);
2692 HOST_WIDE_INT maxint = highint - lowint;
2693 return type_hash_canon (maxint > 0 ? maxint : - maxint, itype);
2699 /* Return nonzero iff ITYPE1 and ITYPE2 are equal (in the LISP sense).
2700 Needed because when index types are not hashed, equal index types
2701 built at different times appear distinct, even though structurally,
2705 index_type_equal (itype1, itype2)
2706 tree itype1, itype2;
2708 if (TREE_CODE (itype1) != TREE_CODE (itype2))
2710 if (TREE_CODE (itype1) == INTEGER_TYPE)
2712 if (TYPE_PRECISION (itype1) != TYPE_PRECISION (itype2)
2713 || TYPE_MODE (itype1) != TYPE_MODE (itype2)
2714 || ! simple_cst_equal (TYPE_SIZE (itype1), TYPE_SIZE (itype2))
2715 || TYPE_ALIGN (itype1) != TYPE_ALIGN (itype2))
2717 if (simple_cst_equal (TYPE_MIN_VALUE (itype1), TYPE_MIN_VALUE (itype2))
2718 && simple_cst_equal (TYPE_MAX_VALUE (itype1), TYPE_MAX_VALUE (itype2)))
2724 /* Construct, lay out and return the type of arrays of elements with ELT_TYPE
2725 and number of elements specified by the range of values of INDEX_TYPE.
2726 If such a type has already been constructed, reuse it. */
2729 build_array_type (elt_type, index_type)
2730 tree elt_type, index_type;
2735 if (TREE_CODE (elt_type) == FUNCTION_TYPE)
2737 error ("arrays of functions are not meaningful");
2738 elt_type = integer_type_node;
2741 /* Make sure TYPE_POINTER_TO (elt_type) is filled in. */
2742 build_pointer_type (elt_type);
2744 /* Allocate the array after the pointer type,
2745 in case we free it in type_hash_canon. */
2746 t = make_node (ARRAY_TYPE);
2747 TREE_TYPE (t) = elt_type;
2748 TYPE_DOMAIN (t) = index_type;
2750 if (index_type == 0)
2753 hashcode = TYPE_HASH (elt_type) + TYPE_HASH (index_type);
2754 t = type_hash_canon (hashcode, t);
2756 if (TYPE_SIZE (t) == 0)
2761 /* Construct, lay out and return
2762 the type of functions returning type VALUE_TYPE
2763 given arguments of types ARG_TYPES.
2764 ARG_TYPES is a chain of TREE_LIST nodes whose TREE_VALUEs
2765 are data type nodes for the arguments of the function.
2766 If such a type has already been constructed, reuse it. */
2769 build_function_type (value_type, arg_types)
2770 tree value_type, arg_types;
2775 if (TREE_CODE (value_type) == FUNCTION_TYPE
2776 || TREE_CODE (value_type) == ARRAY_TYPE)
2778 error ("function return type cannot be function or array");
2779 value_type = integer_type_node;
2782 /* Make a node of the sort we want. */
2783 t = make_node (FUNCTION_TYPE);
2784 TREE_TYPE (t) = value_type;
2785 TYPE_ARG_TYPES (t) = arg_types;
2787 /* If we already have such a type, use the old one and free this one. */
2788 hashcode = TYPE_HASH (value_type) + type_hash_list (arg_types);
2789 t = type_hash_canon (hashcode, t);
2791 if (TYPE_SIZE (t) == 0)
2796 /* Build the node for the type of references-to-TO_TYPE. */
2799 build_reference_type (to_type)
2802 register tree t = TYPE_REFERENCE_TO (to_type);
2803 register struct obstack *ambient_obstack = current_obstack;
2804 register struct obstack *ambient_saveable_obstack = saveable_obstack;
2806 /* First, if we already have a type for pointers to TO_TYPE, use it. */
2811 /* We need a new one. If TO_TYPE is permanent, make this permanent too. */
2812 if (TREE_PERMANENT (to_type))
2814 current_obstack = &permanent_obstack;
2815 saveable_obstack = &permanent_obstack;
2818 t = make_node (REFERENCE_TYPE);
2819 TREE_TYPE (t) = to_type;
2821 /* Record this type as the pointer to TO_TYPE. */
2822 TYPE_REFERENCE_TO (to_type) = t;
2826 current_obstack = ambient_obstack;
2827 saveable_obstack = ambient_saveable_obstack;
2831 /* Construct, lay out and return the type of methods belonging to class
2832 BASETYPE and whose arguments and values are described by TYPE.
2833 If that type exists already, reuse it.
2834 TYPE must be a FUNCTION_TYPE node. */
2837 build_method_type (basetype, type)
2838 tree basetype, type;
2843 /* Make a node of the sort we want. */
2844 t = make_node (METHOD_TYPE);
2846 if (TREE_CODE (type) != FUNCTION_TYPE)
2849 TYPE_METHOD_BASETYPE (t) = TYPE_MAIN_VARIANT (basetype);
2850 TREE_TYPE (t) = TREE_TYPE (type);
2852 /* The actual arglist for this function includes a "hidden" argument
2853 which is "this". Put it into the list of argument types. */
2856 = tree_cons (NULL_TREE,
2857 build_pointer_type (basetype), TYPE_ARG_TYPES (type));
2859 /* If we already have such a type, use the old one and free this one. */
2860 hashcode = TYPE_HASH (basetype) + TYPE_HASH (type);
2861 t = type_hash_canon (hashcode, t);
2863 if (TYPE_SIZE (t) == 0)
2869 /* Construct, lay out and return the type of methods belonging to class
2870 BASETYPE and whose arguments and values are described by TYPE.
2871 If that type exists already, reuse it.
2872 TYPE must be a FUNCTION_TYPE node. */
2875 build_offset_type (basetype, type)
2876 tree basetype, type;
2881 /* Make a node of the sort we want. */
2882 t = make_node (OFFSET_TYPE);
2884 TYPE_OFFSET_BASETYPE (t) = TYPE_MAIN_VARIANT (basetype);
2885 TREE_TYPE (t) = type;
2887 /* If we already have such a type, use the old one and free this one. */
2888 hashcode = TYPE_HASH (basetype) + TYPE_HASH (type);
2889 t = type_hash_canon (hashcode, t);
2891 if (TYPE_SIZE (t) == 0)
2897 /* Create a complex type whose components are COMPONENT_TYPE. */
2900 build_complex_type (component_type)
2901 tree component_type;
2906 /* Make a node of the sort we want. */
2907 t = make_node (COMPLEX_TYPE);
2909 TREE_TYPE (t) = TYPE_MAIN_VARIANT (component_type);
2910 TYPE_VOLATILE (t) = TYPE_VOLATILE (component_type);
2911 TYPE_READONLY (t) = TYPE_READONLY (component_type);
2913 /* If we already have such a type, use the old one and free this one. */
2914 hashcode = TYPE_HASH (component_type);
2915 t = type_hash_canon (hashcode, t);
2917 if (TYPE_SIZE (t) == 0)
2923 /* Return OP, stripped of any conversions to wider types as much as is safe.
2924 Converting the value back to OP's type makes a value equivalent to OP.
2926 If FOR_TYPE is nonzero, we return a value which, if converted to
2927 type FOR_TYPE, would be equivalent to converting OP to type FOR_TYPE.
2929 If FOR_TYPE is nonzero, unaligned bit-field references may be changed to the
2930 narrowest type that can hold the value, even if they don't exactly fit.
2931 Otherwise, bit-field references are changed to a narrower type
2932 only if they can be fetched directly from memory in that type.
2934 OP must have integer, real or enumeral type. Pointers are not allowed!
2936 There are some cases where the obvious value we could return
2937 would regenerate to OP if converted to OP's type,
2938 but would not extend like OP to wider types.
2939 If FOR_TYPE indicates such extension is contemplated, we eschew such values.
2940 For example, if OP is (unsigned short)(signed char)-1,
2941 we avoid returning (signed char)-1 if FOR_TYPE is int,
2942 even though extending that to an unsigned short would regenerate OP,
2943 since the result of extending (signed char)-1 to (int)
2944 is different from (int) OP. */
2947 get_unwidened (op, for_type)
2951 /* Set UNS initially if converting OP to FOR_TYPE is a zero-extension. */
2952 /* TYPE_PRECISION is safe in place of type_precision since
2953 pointer types are not allowed. */
2954 register tree type = TREE_TYPE (op);
2955 register unsigned final_prec
2956 = TYPE_PRECISION (for_type != 0 ? for_type : type);
2958 = (for_type != 0 && for_type != type
2959 && final_prec > TYPE_PRECISION (type)
2960 && TREE_UNSIGNED (type));
2961 register tree win = op;
2963 while (TREE_CODE (op) == NOP_EXPR)
2965 register int bitschange
2966 = TYPE_PRECISION (TREE_TYPE (op))
2967 - TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (op, 0)));
2969 /* Truncations are many-one so cannot be removed.
2970 Unless we are later going to truncate down even farther. */
2972 && final_prec > TYPE_PRECISION (TREE_TYPE (op)))
2975 /* See what's inside this conversion. If we decide to strip it,
2977 op = TREE_OPERAND (op, 0);
2979 /* If we have not stripped any zero-extensions (uns is 0),
2980 we can strip any kind of extension.
2981 If we have previously stripped a zero-extension,
2982 only zero-extensions can safely be stripped.
2983 Any extension can be stripped if the bits it would produce
2984 are all going to be discarded later by truncating to FOR_TYPE. */
2988 if (! uns || final_prec <= TYPE_PRECISION (TREE_TYPE (op)))
2990 /* TREE_UNSIGNED says whether this is a zero-extension.
2991 Let's avoid computing it if it does not affect WIN
2992 and if UNS will not be needed again. */
2993 if ((uns || TREE_CODE (op) == NOP_EXPR)
2994 && TREE_UNSIGNED (TREE_TYPE (op)))
3002 if (TREE_CODE (op) == COMPONENT_REF
3003 /* Since type_for_size always gives an integer type. */
3004 && TREE_CODE (type) != REAL_TYPE)
3006 unsigned innerprec = TREE_INT_CST_LOW (DECL_SIZE (TREE_OPERAND (op, 1)));
3007 type = type_for_size (innerprec, TREE_UNSIGNED (TREE_OPERAND (op, 1)));
3009 /* We can get this structure field in the narrowest type it fits in.
3010 If FOR_TYPE is 0, do this only for a field that matches the
3011 narrower type exactly and is aligned for it
3012 The resulting extension to its nominal type (a fullword type)
3013 must fit the same conditions as for other extensions. */
3015 if (innerprec < TYPE_PRECISION (TREE_TYPE (op))
3016 && (for_type || ! DECL_BIT_FIELD (TREE_OPERAND (op, 1)))
3017 && (! uns || final_prec <= innerprec
3018 || TREE_UNSIGNED (TREE_OPERAND (op, 1)))
3021 win = build (COMPONENT_REF, type, TREE_OPERAND (op, 0),
3022 TREE_OPERAND (op, 1));
3023 TREE_SIDE_EFFECTS (win) = TREE_SIDE_EFFECTS (op);
3024 TREE_THIS_VOLATILE (win) = TREE_THIS_VOLATILE (op);
3025 TREE_RAISES (win) = TREE_RAISES (op);
3031 /* Return OP or a simpler expression for a narrower value
3032 which can be sign-extended or zero-extended to give back OP.
3033 Store in *UNSIGNEDP_PTR either 1 if the value should be zero-extended
3034 or 0 if the value should be sign-extended. */
3037 get_narrower (op, unsignedp_ptr)
3041 register int uns = 0;
3043 register tree win = op;
3045 while (TREE_CODE (op) == NOP_EXPR)
3047 register int bitschange
3048 = TYPE_PRECISION (TREE_TYPE (op))
3049 - TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (op, 0)));
3051 /* Truncations are many-one so cannot be removed. */
3055 /* See what's inside this conversion. If we decide to strip it,
3057 op = TREE_OPERAND (op, 0);
3061 /* An extension: the outermost one can be stripped,
3062 but remember whether it is zero or sign extension. */
3064 uns = TREE_UNSIGNED (TREE_TYPE (op));
3065 /* Otherwise, if a sign extension has been stripped,
3066 only sign extensions can now be stripped;
3067 if a zero extension has been stripped, only zero-extensions. */
3068 else if (uns != TREE_UNSIGNED (TREE_TYPE (op)))
3072 /* A change in nominal type can always be stripped. */
3077 if (TREE_CODE (op) == COMPONENT_REF
3078 /* Since type_for_size always gives an integer type. */
3079 && TREE_CODE (TREE_TYPE (op)) != REAL_TYPE)
3081 unsigned innerprec = TREE_INT_CST_LOW (DECL_SIZE (TREE_OPERAND (op, 1)));
3082 tree type = type_for_size (innerprec, TREE_UNSIGNED (op));
3084 /* We can get this structure field in a narrower type that fits it,
3085 but the resulting extension to its nominal type (a fullword type)
3086 must satisfy the same conditions as for other extensions.
3088 Do this only for fields that are aligned (not bit-fields),
3089 because when bit-field insns will be used there is no
3090 advantage in doing this. */
3092 if (innerprec < TYPE_PRECISION (TREE_TYPE (op))
3093 && ! DECL_BIT_FIELD (TREE_OPERAND (op, 1))
3094 && (first || uns == TREE_UNSIGNED (TREE_OPERAND (op, 1)))
3098 uns = TREE_UNSIGNED (TREE_OPERAND (op, 1));
3099 win = build (COMPONENT_REF, type, TREE_OPERAND (op, 0),
3100 TREE_OPERAND (op, 1));
3101 TREE_SIDE_EFFECTS (win) = TREE_SIDE_EFFECTS (op);
3102 TREE_THIS_VOLATILE (win) = TREE_THIS_VOLATILE (op);
3103 TREE_RAISES (win) = TREE_RAISES (op);
3106 *unsignedp_ptr = uns;
3110 /* Return the precision of a type, for arithmetic purposes.
3111 Supports all types on which arithmetic is possible
3112 (including pointer types).
3113 It's not clear yet what will be right for complex types. */
3116 type_precision (type)
3119 return ((TREE_CODE (type) == INTEGER_TYPE
3120 || TREE_CODE (type) == ENUMERAL_TYPE
3121 || TREE_CODE (type) == REAL_TYPE)
3122 ? TYPE_PRECISION (type) : POINTER_SIZE);
3125 /* Nonzero if integer constant C has a value that is permissible
3126 for type TYPE (an INTEGER_TYPE). */
3129 int_fits_type_p (c, type)
3132 if (TREE_UNSIGNED (type))
3133 return (!INT_CST_LT_UNSIGNED (TYPE_MAX_VALUE (type), c)
3134 && !INT_CST_LT_UNSIGNED (c, TYPE_MIN_VALUE (type)));
3136 return (!INT_CST_LT (TYPE_MAX_VALUE (type), c)
3137 && !INT_CST_LT (c, TYPE_MIN_VALUE (type)));
3140 /* Return the innermost context enclosing DECL that is
3141 a FUNCTION_DECL, or zero if none. */
3144 decl_function_context (decl)
3149 if (TREE_CODE (decl) == ERROR_MARK)
3152 if (TREE_CODE (decl) == SAVE_EXPR)
3153 context = SAVE_EXPR_CONTEXT (decl);
3155 context = DECL_CONTEXT (decl);
3157 while (context && TREE_CODE (context) != FUNCTION_DECL)
3159 if (TREE_CODE (context) == RECORD_TYPE
3160 || TREE_CODE (context) == UNION_TYPE)
3161 context = TYPE_CONTEXT (context);
3162 else if (TREE_CODE (context) == TYPE_DECL)
3163 context = DECL_CONTEXT (context);
3164 else if (TREE_CODE (context) == BLOCK)
3165 context = BLOCK_SUPERCONTEXT (context);
3167 /* Unhandled CONTEXT !? */
3174 /* Return the innermost context enclosing DECL that is
3175 a RECORD_TYPE or UNION_TYPE, or zero if none.
3176 TYPE_DECLs and FUNCTION_DECLs are transparent to this function. */
3179 decl_type_context (decl)
3182 tree context = DECL_CONTEXT (decl);
3186 if (TREE_CODE (context) == RECORD_TYPE
3187 || TREE_CODE (context) == UNION_TYPE)
3189 if (TREE_CODE (context) == TYPE_DECL
3190 || TREE_CODE (context) == FUNCTION_DECL)
3191 context = DECL_CONTEXT (context);
3192 else if (TREE_CODE (context) == BLOCK)
3193 context = BLOCK_SUPERCONTEXT (context);
3195 /* Unhandled CONTEXT!? */
3202 print_obstack_statistics (str, o)
3206 struct _obstack_chunk *chunk = o->chunk;
3213 n_alloc += chunk->limit - &chunk->contents[0];
3214 chunk = chunk->prev;
3216 fprintf (stderr, "obstack %s: %d bytes, %d chunks\n",
3217 str, n_alloc, n_chunks);
3220 dump_tree_statistics ()
3223 int total_nodes, total_bytes;
3225 fprintf (stderr, "\n??? tree nodes created\n\n");
3226 #ifdef GATHER_STATISTICS
3227 fprintf (stderr, "Kind Nodes Bytes\n");
3228 fprintf (stderr, "-------------------------------------\n");
3229 total_nodes = total_bytes = 0;
3230 for (i = 0; i < (int) all_kinds; i++)
3232 fprintf (stderr, "%-20s %6d %9d\n", tree_node_kind_names[i],
3233 tree_node_counts[i], tree_node_sizes[i]);
3234 total_nodes += tree_node_counts[i];
3235 total_bytes += tree_node_sizes[i];
3237 fprintf (stderr, "%-20s %9d\n", "identifier names", id_string_size);
3238 fprintf (stderr, "-------------------------------------\n");
3239 fprintf (stderr, "%-20s %6d %9d\n", "Total", total_nodes, total_bytes);
3240 fprintf (stderr, "-------------------------------------\n");
3242 fprintf (stderr, "(No per-node statistics)\n");
3244 print_lang_statistics ();