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 /* Start allocating rtl from saveable_obstack. Intended to be used after
528 a call to push_obstacks_nochange. */
531 rtl_in_saveable_obstack ()
533 rtl_obstack = saveable_obstack;
536 /* Allocate SIZE bytes in the current obstack
537 and return a pointer to them.
538 In practice the current obstack is always the temporary one. */
544 return (char *) obstack_alloc (current_obstack, size);
547 /* Free the object PTR in the current obstack
548 as well as everything allocated since PTR.
549 In practice the current obstack is always the temporary one. */
555 obstack_free (current_obstack, ptr);
558 /* Allocate SIZE bytes in the permanent obstack
559 and return a pointer to them. */
565 return (char *) obstack_alloc (&permanent_obstack, size);
568 /* Allocate NELEM items of SIZE bytes in the permanent obstack
569 and return a pointer to them. The storage is cleared before
570 returning the value. */
573 perm_calloc (nelem, size)
577 char *rval = (char *) obstack_alloc (&permanent_obstack, nelem * size);
578 bzero (rval, nelem * size);
582 /* Allocate SIZE bytes in the saveable obstack
583 and return a pointer to them. */
589 return (char *) obstack_alloc (saveable_obstack, size);
592 /* Print out which obstack an object is in. */
595 debug_obstack (object)
598 struct obstack *obstack = NULL;
599 char *obstack_name = NULL;
602 for (p = outer_function_chain; p; p = p->next)
604 if (_obstack_allocated_p (p->function_obstack, object))
606 obstack = p->function_obstack;
607 obstack_name = "containing function obstack";
609 if (_obstack_allocated_p (p->function_maybepermanent_obstack, object))
611 obstack = p->function_maybepermanent_obstack;
612 obstack_name = "containing function maybepermanent obstack";
616 if (_obstack_allocated_p (&obstack_stack_obstack, object))
618 obstack = &obstack_stack_obstack;
619 obstack_name = "obstack_stack_obstack";
621 else if (_obstack_allocated_p (function_obstack, object))
623 obstack = function_obstack;
624 obstack_name = "function obstack";
626 else if (_obstack_allocated_p (&permanent_obstack, object))
628 obstack = &permanent_obstack;
629 obstack_name = "permanent_obstack";
631 else if (_obstack_allocated_p (&momentary_obstack, object))
633 obstack = &momentary_obstack;
634 obstack_name = "momentary_obstack";
636 else if (_obstack_allocated_p (function_maybepermanent_obstack, object))
638 obstack = function_maybepermanent_obstack;
639 obstack_name = "function maybepermanent obstack";
641 else if (_obstack_allocated_p (&temp_decl_obstack, object))
643 obstack = &temp_decl_obstack;
644 obstack_name = "temp_decl_obstack";
647 /* Check to see if the object is in the free area of the obstack. */
650 if (object >= obstack->next_free
651 && object < obstack->chunk_limit)
652 fprintf (stderr, "object in free portion of obstack %s.\n",
655 fprintf (stderr, "object allocated from %s.\n", obstack_name);
658 fprintf (stderr, "object not allocated from any obstack.\n");
661 /* Return 1 if OBJ is in the permanent obstack.
662 This is slow, and should be used only for debugging.
663 Use TREE_PERMANENT for other purposes. */
666 object_permanent_p (obj)
669 return _obstack_allocated_p (&permanent_obstack, obj);
672 /* Start a level of momentary allocation.
673 In C, each compound statement has its own level
674 and that level is freed at the end of each statement.
675 All expression nodes are allocated in the momentary allocation level. */
680 struct momentary_level *tem
681 = (struct momentary_level *) obstack_alloc (&momentary_obstack,
682 sizeof (struct momentary_level));
683 tem->prev = momentary_stack;
684 tem->base = (char *) obstack_base (&momentary_obstack);
685 tem->obstack = expression_obstack;
686 momentary_stack = tem;
687 expression_obstack = &momentary_obstack;
690 /* Free all the storage in the current momentary-allocation level.
691 In C, this happens at the end of each statement. */
696 obstack_free (&momentary_obstack, momentary_stack->base);
699 /* Discard a level of momentary allocation.
700 In C, this happens at the end of each compound statement.
701 Restore the status of expression node allocation
702 that was in effect before this level was created. */
707 struct momentary_level *tem = momentary_stack;
708 momentary_stack = tem->prev;
709 expression_obstack = tem->obstack;
710 obstack_free (&momentary_obstack, tem);
713 /* Call when starting to parse a declaration:
714 make expressions in the declaration last the length of the function.
715 Returns an argument that should be passed to resume_momentary later. */
720 register int tem = expression_obstack == &momentary_obstack;
721 expression_obstack = saveable_obstack;
725 /* Call when finished parsing a declaration:
726 restore the treatment of node-allocation that was
727 in effect before the suspension.
728 YES should be the value previously returned by suspend_momentary. */
731 resume_momentary (yes)
735 expression_obstack = &momentary_obstack;
738 /* Init the tables indexed by tree code.
739 Note that languages can add to these tables to define their own codes. */
744 tree_code_type = (char **) xmalloc (sizeof (standard_tree_code_type));
745 tree_code_length = (int *) xmalloc (sizeof (standard_tree_code_length));
746 tree_code_name = (char **) xmalloc (sizeof (standard_tree_code_name));
747 bcopy (standard_tree_code_type, tree_code_type,
748 sizeof (standard_tree_code_type));
749 bcopy (standard_tree_code_length, tree_code_length,
750 sizeof (standard_tree_code_length));
751 bcopy (standard_tree_code_name, tree_code_name,
752 sizeof (standard_tree_code_name));
755 /* Return a newly allocated node of code CODE.
756 Initialize the node's unique id and its TREE_PERMANENT flag.
757 For decl and type nodes, some other fields are initialized.
758 The rest of the node is initialized to zero.
760 Achoo! I got a code in the node. */
767 register int type = TREE_CODE_CLASS (code);
769 register struct obstack *obstack = current_obstack;
771 register tree_node_kind kind;
775 case 'd': /* A decl node */
776 #ifdef GATHER_STATISTICS
779 length = sizeof (struct tree_decl);
780 /* All decls in an inline function need to be saved. */
781 if (obstack != &permanent_obstack)
782 obstack = saveable_obstack;
783 /* PARM_DECLs always go on saveable_obstack, not permanent,
784 even though we may make them before the function turns
785 on temporary allocation. */
786 else if (code == PARM_DECL)
787 obstack = function_maybepermanent_obstack;
790 case 't': /* a type node */
791 #ifdef GATHER_STATISTICS
794 length = sizeof (struct tree_type);
795 /* All data types are put where we can preserve them if nec. */
796 if (obstack != &permanent_obstack)
797 obstack = all_types_permanent ? &permanent_obstack : saveable_obstack;
800 case 'b': /* a lexical block */
801 #ifdef GATHER_STATISTICS
804 length = sizeof (struct tree_block);
805 /* All BLOCK nodes are put where we can preserve them if nec. */
806 if (obstack != &permanent_obstack)
807 obstack = saveable_obstack;
810 case 's': /* an expression with side effects */
811 #ifdef GATHER_STATISTICS
815 case 'r': /* a reference */
816 #ifdef GATHER_STATISTICS
820 case 'e': /* an expression */
821 case '<': /* a comparison expression */
822 case '1': /* a unary arithmetic expression */
823 case '2': /* a binary arithmetic expression */
824 #ifdef GATHER_STATISTICS
828 obstack = expression_obstack;
829 /* All BIND_EXPR nodes are put where we can preserve them if nec. */
830 if (code == BIND_EXPR && obstack != &permanent_obstack)
831 obstack = saveable_obstack;
832 length = sizeof (struct tree_exp)
833 + (tree_code_length[(int) code] - 1) * sizeof (char *);
836 case 'c': /* a constant */
837 #ifdef GATHER_STATISTICS
840 obstack = expression_obstack;
842 /* We can't use tree_code_length for INTEGER_CST, since the number of
843 words is machine-dependent due to varying length of HOST_WIDE_INT,
844 which might be wider than a pointer (e.g., long long). Similarly
845 for REAL_CST, since the number of words is machine-dependent due
846 to varying size and alignment of `double'. */
848 if (code == INTEGER_CST)
849 length = sizeof (struct tree_int_cst);
850 else if (code == REAL_CST)
851 length = sizeof (struct tree_real_cst);
853 length = sizeof (struct tree_common)
854 + tree_code_length[(int) code] * sizeof (char *);
857 case 'x': /* something random, like an identifier. */
858 #ifdef GATHER_STATISTICS
859 if (code == IDENTIFIER_NODE)
861 else if (code == OP_IDENTIFIER)
863 else if (code == TREE_VEC)
868 length = sizeof (struct tree_common)
869 + tree_code_length[(int) code] * sizeof (char *);
870 /* Identifier nodes are always permanent since they are
871 unique in a compiler run. */
872 if (code == IDENTIFIER_NODE) obstack = &permanent_obstack;
875 t = (tree) obstack_alloc (obstack, length);
877 #ifdef GATHER_STATISTICS
878 tree_node_counts[(int)kind]++;
879 tree_node_sizes[(int)kind] += length;
882 /* Clear a word at a time. */
883 for (i = (length / sizeof (int)) - 1; i >= 0; i--)
885 /* Clear any extra bytes. */
886 for (i = length / sizeof (int) * sizeof (int); i < length; i++)
889 TREE_SET_CODE (t, code);
890 if (obstack == &permanent_obstack)
891 TREE_PERMANENT (t) = 1;
896 TREE_SIDE_EFFECTS (t) = 1;
897 TREE_TYPE (t) = void_type_node;
901 if (code != FUNCTION_DECL)
903 DECL_IN_SYSTEM_HEADER (t)
904 = in_system_header && (obstack == &permanent_obstack);
905 DECL_SOURCE_LINE (t) = lineno;
906 DECL_SOURCE_FILE (t) = (input_filename) ? input_filename : "<built-in>";
907 DECL_UID (t) = next_decl_uid++;
912 static unsigned next_type_uid = 1;
914 TYPE_UID (t) = next_type_uid++;
917 TYPE_MAIN_VARIANT (t) = t;
921 TREE_CONSTANT (t) = 1;
928 /* Return a new node with the same contents as NODE
929 except that its TREE_CHAIN is zero and it has a fresh uid. */
936 register enum tree_code code = TREE_CODE (node);
940 switch (TREE_CODE_CLASS (code))
942 case 'd': /* A decl node */
943 length = sizeof (struct tree_decl);
946 case 't': /* a type node */
947 length = sizeof (struct tree_type);
950 case 'b': /* a lexical block node */
951 length = sizeof (struct tree_block);
954 case 'r': /* a reference */
955 case 'e': /* an expression */
956 case 's': /* an expression with side effects */
957 case '<': /* a comparison expression */
958 case '1': /* a unary arithmetic expression */
959 case '2': /* a binary arithmetic expression */
960 length = sizeof (struct tree_exp)
961 + (tree_code_length[(int) code] - 1) * sizeof (char *);
964 case 'c': /* a constant */
965 /* We can't use tree_code_length for this, since the number of words
966 is machine-dependent due to varying alignment of `double'. */
967 if (code == REAL_CST)
969 length = sizeof (struct tree_real_cst);
973 case 'x': /* something random, like an identifier. */
974 length = sizeof (struct tree_common)
975 + tree_code_length[(int) code] * sizeof (char *);
976 if (code == TREE_VEC)
977 length += (TREE_VEC_LENGTH (node) - 1) * sizeof (char *);
980 t = (tree) obstack_alloc (current_obstack, length);
982 for (i = (length / sizeof (int)) - 1; i >= 0; i--)
983 ((int *) t)[i] = ((int *) node)[i];
984 /* Clear any extra bytes. */
985 for (i = length / sizeof (int) * sizeof (int); i < length; i++)
986 ((char *) t)[i] = ((char *) node)[i];
990 TREE_PERMANENT (t) = (current_obstack == &permanent_obstack);
995 /* Return a copy of a chain of nodes, chained through the TREE_CHAIN field.
996 For example, this can copy a list made of TREE_LIST nodes. */
1003 register tree prev, next;
1008 head = prev = copy_node (list);
1009 next = TREE_CHAIN (list);
1012 TREE_CHAIN (prev) = copy_node (next);
1013 prev = TREE_CHAIN (prev);
1014 next = TREE_CHAIN (next);
1021 /* Return an IDENTIFIER_NODE whose name is TEXT (a null-terminated string).
1022 If an identifier with that name has previously been referred to,
1023 the same node is returned this time. */
1026 get_identifier (text)
1027 register char *text;
1032 register int len, hash_len;
1034 /* Compute length of text in len. */
1035 for (len = 0; text[len]; len++);
1037 /* Decide how much of that length to hash on */
1039 if (warn_id_clash && len > id_clash_len)
1040 hash_len = id_clash_len;
1042 /* Compute hash code */
1043 hi = hash_len * 613 + (unsigned)text[0];
1044 for (i = 1; i < hash_len; i += 2)
1045 hi = ((hi * 613) + (unsigned)(text[i]));
1047 hi &= (1 << HASHBITS) - 1;
1048 hi %= MAX_HASH_TABLE;
1050 /* Search table for identifier */
1051 for (idp = hash_table[hi]; idp; idp = TREE_CHAIN (idp))
1052 if (IDENTIFIER_LENGTH (idp) == len
1053 && IDENTIFIER_POINTER (idp)[0] == text[0]
1054 && !bcmp (IDENTIFIER_POINTER (idp), text, len))
1055 return idp; /* <-- return if found */
1057 /* Not found; optionally warn about a similar identifier */
1058 if (warn_id_clash && do_identifier_warnings && len >= id_clash_len)
1059 for (idp = hash_table[hi]; idp; idp = TREE_CHAIN (idp))
1060 if (!strncmp (IDENTIFIER_POINTER (idp), text, id_clash_len))
1062 warning ("`%s' and `%s' identical in first %d characters",
1063 IDENTIFIER_POINTER (idp), text, id_clash_len);
1067 if (tree_code_length[(int) IDENTIFIER_NODE] < 0)
1068 abort (); /* set_identifier_size hasn't been called. */
1070 /* Not found, create one, add to chain */
1071 idp = make_node (IDENTIFIER_NODE);
1072 IDENTIFIER_LENGTH (idp) = len;
1073 #ifdef GATHER_STATISTICS
1074 id_string_size += len;
1077 IDENTIFIER_POINTER (idp) = obstack_copy0 (&permanent_obstack, text, len);
1079 TREE_CHAIN (idp) = hash_table[hi];
1080 hash_table[hi] = idp;
1081 return idp; /* <-- return if created */
1084 /* Enable warnings on similar identifiers (if requested).
1085 Done after the built-in identifiers are created. */
1088 start_identifier_warnings ()
1090 do_identifier_warnings = 1;
1093 /* Record the size of an identifier node for the language in use.
1094 SIZE is the total size in bytes.
1095 This is called by the language-specific files. This must be
1096 called before allocating any identifiers. */
1099 set_identifier_size (size)
1102 tree_code_length[(int) IDENTIFIER_NODE]
1103 = (size - sizeof (struct tree_common)) / sizeof (tree);
1106 /* Return a newly constructed INTEGER_CST node whose constant value
1107 is specified by the two ints LOW and HI.
1108 The TREE_TYPE is set to `int'.
1110 This function should be used via the `build_int_2' macro. */
1113 build_int_2_wide (low, hi)
1114 HOST_WIDE_INT low, hi;
1116 register tree t = make_node (INTEGER_CST);
1117 TREE_INT_CST_LOW (t) = low;
1118 TREE_INT_CST_HIGH (t) = hi;
1119 TREE_TYPE (t) = integer_type_node;
1123 /* Return a new REAL_CST node whose type is TYPE and value is D. */
1126 build_real (type, d)
1132 /* Check for valid float value for this type on this target machine;
1133 if not, can print error message and store a valid value in D. */
1134 #ifdef CHECK_FLOAT_VALUE
1135 CHECK_FLOAT_VALUE (TYPE_MODE (type), d);
1138 v = make_node (REAL_CST);
1139 TREE_TYPE (v) = type;
1140 TREE_REAL_CST (v) = d;
1144 /* Return a new REAL_CST node whose type is TYPE
1145 and whose value is the integer value of the INTEGER_CST node I. */
1147 #if !defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
1150 real_value_from_int_cst (i)
1154 #ifdef REAL_ARITHMETIC
1155 REAL_VALUE_FROM_INT (d, TREE_INT_CST_LOW (i), TREE_INT_CST_HIGH (i));
1156 #else /* not REAL_ARITHMETIC */
1157 if (TREE_INT_CST_HIGH (i) < 0 && ! TREE_UNSIGNED (TREE_TYPE (i)))
1159 d = (double) (~ TREE_INT_CST_HIGH (i));
1160 d *= ((double) ((HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2))
1161 * (double) ((HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2)));
1162 d += (double) (unsigned HOST_WIDE_INT) (~ TREE_INT_CST_LOW (i));
1167 d = (double) (unsigned HOST_WIDE_INT) TREE_INT_CST_HIGH (i);
1168 d *= ((double) ((HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2))
1169 * (double) ((HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2)));
1170 d += (double) (unsigned HOST_WIDE_INT) TREE_INT_CST_LOW (i);
1172 #endif /* not REAL_ARITHMETIC */
1176 /* This function can't be implemented if we can't do arithmetic
1177 on the float representation. */
1180 build_real_from_int_cst (type, i)
1187 v = make_node (REAL_CST);
1188 TREE_TYPE (v) = type;
1190 d = REAL_VALUE_TRUNCATE (TYPE_MODE (type), real_value_from_int_cst (i));
1191 /* Check for valid float value for this type on this target machine;
1192 if not, can print error message and store a valid value in D. */
1193 #ifdef CHECK_FLOAT_VALUE
1194 CHECK_FLOAT_VALUE (TYPE_MODE (type), d);
1197 TREE_REAL_CST (v) = d;
1201 #endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */
1203 /* Return a newly constructed STRING_CST node whose value is
1204 the LEN characters at STR.
1205 The TREE_TYPE is not initialized. */
1208 build_string (len, str)
1212 register tree s = make_node (STRING_CST);
1213 TREE_STRING_LENGTH (s) = len;
1214 TREE_STRING_POINTER (s) = obstack_copy0 (saveable_obstack, str, len);
1218 /* Return a newly constructed COMPLEX_CST node whose value is
1219 specified by the real and imaginary parts REAL and IMAG.
1220 Both REAL and IMAG should be constant nodes.
1221 The TREE_TYPE is not initialized. */
1224 build_complex (real, imag)
1227 register tree t = make_node (COMPLEX_CST);
1228 TREE_REALPART (t) = real;
1229 TREE_IMAGPART (t) = imag;
1233 /* Build a newly constructed TREE_VEC node of length LEN. */
1239 register int length = (len-1) * sizeof (tree) + sizeof (struct tree_vec);
1240 register struct obstack *obstack = current_obstack;
1243 #ifdef GATHER_STATISTICS
1244 tree_node_counts[(int)vec_kind]++;
1245 tree_node_sizes[(int)vec_kind] += length;
1248 t = (tree) obstack_alloc (obstack, length);
1250 for (i = (length / sizeof (int)) - 1; i >= 0; i--)
1253 TREE_SET_CODE (t, TREE_VEC);
1254 TREE_VEC_LENGTH (t) = len;
1255 if (obstack == &permanent_obstack)
1256 TREE_PERMANENT (t) = 1;
1261 /* Return 1 if EXPR is the integer constant zero. */
1264 integer_zerop (expr)
1269 return (TREE_CODE (expr) == INTEGER_CST
1270 && TREE_INT_CST_LOW (expr) == 0
1271 && TREE_INT_CST_HIGH (expr) == 0);
1274 /* Return 1 if EXPR is the integer constant one. */
1282 return (TREE_CODE (expr) == INTEGER_CST
1283 && TREE_INT_CST_LOW (expr) == 1
1284 && TREE_INT_CST_HIGH (expr) == 0);
1287 /* Return 1 if EXPR is an integer containing all 1's
1288 in as much precision as it contains. */
1291 integer_all_onesp (expr)
1299 if (TREE_CODE (expr) != INTEGER_CST)
1302 uns = TREE_UNSIGNED (TREE_TYPE (expr));
1304 return TREE_INT_CST_LOW (expr) == -1 && TREE_INT_CST_HIGH (expr) == -1;
1306 prec = TYPE_PRECISION (TREE_TYPE (expr));
1307 if (prec >= HOST_BITS_PER_WIDE_INT)
1309 int high_value, shift_amount;
1311 shift_amount = prec - HOST_BITS_PER_WIDE_INT;
1313 if (shift_amount > HOST_BITS_PER_WIDE_INT)
1314 /* Can not handle precisions greater than twice the host int size. */
1316 else if (shift_amount == HOST_BITS_PER_WIDE_INT)
1317 /* Shifting by the host word size is undefined according to the ANSI
1318 standard, so we must handle this as a special case. */
1321 high_value = ((HOST_WIDE_INT) 1 << shift_amount) - 1;
1323 return TREE_INT_CST_LOW (expr) == -1
1324 && TREE_INT_CST_HIGH (expr) == high_value;
1327 return TREE_INT_CST_LOW (expr) == ((HOST_WIDE_INT) 1 << prec) - 1;
1330 /* Return 1 if EXPR is an integer constant that is a power of 2 (i.e., has only
1334 integer_pow2p (expr)
1337 HOST_WIDE_INT high, low;
1341 if (TREE_CODE (expr) != INTEGER_CST)
1344 high = TREE_INT_CST_HIGH (expr);
1345 low = TREE_INT_CST_LOW (expr);
1347 if (high == 0 && low == 0)
1350 return ((high == 0 && (low & (low - 1)) == 0)
1351 || (low == 0 && (high & (high - 1)) == 0));
1354 /* Return 1 if EXPR is the real constant zero. */
1362 return (TREE_CODE (expr) == REAL_CST
1363 && REAL_VALUES_EQUAL (TREE_REAL_CST (expr), dconst0));
1366 /* Return 1 if EXPR is the real constant one. */
1374 return (TREE_CODE (expr) == REAL_CST
1375 && REAL_VALUES_EQUAL (TREE_REAL_CST (expr), dconst1));
1378 /* Return 1 if EXPR is the real constant two. */
1386 return (TREE_CODE (expr) == REAL_CST
1387 && REAL_VALUES_EQUAL (TREE_REAL_CST (expr), dconst2));
1390 /* Nonzero if EXP is a constant or a cast of a constant. */
1393 really_constant_p (exp)
1396 /* This is not quite the same as STRIP_NOPS. It does more. */
1397 while (TREE_CODE (exp) == NOP_EXPR
1398 || TREE_CODE (exp) == CONVERT_EXPR
1399 || TREE_CODE (exp) == NON_LVALUE_EXPR)
1400 exp = TREE_OPERAND (exp, 0);
1401 return TREE_CONSTANT (exp);
1404 /* Return first list element whose TREE_VALUE is ELEM.
1405 Return 0 if ELEM is not it LIST. */
1408 value_member (elem, list)
1413 if (elem == TREE_VALUE (list))
1415 list = TREE_CHAIN (list);
1420 /* Return first list element whose TREE_PURPOSE is ELEM.
1421 Return 0 if ELEM is not it LIST. */
1424 purpose_member (elem, list)
1429 if (elem == TREE_PURPOSE (list))
1431 list = TREE_CHAIN (list);
1436 /* Return first list element whose BINFO_TYPE is ELEM.
1437 Return 0 if ELEM is not it LIST. */
1440 binfo_member (elem, list)
1445 if (elem == BINFO_TYPE (list))
1447 list = TREE_CHAIN (list);
1452 /* Return nonzero if ELEM is part of the chain CHAIN. */
1455 chain_member (elem, chain)
1462 chain = TREE_CHAIN (chain);
1468 /* Return the length of a chain of nodes chained through TREE_CHAIN.
1469 We expect a null pointer to mark the end of the chain.
1470 This is the Lisp primitive `length'. */
1477 register int len = 0;
1479 for (tail = t; tail; tail = TREE_CHAIN (tail))
1485 /* Concatenate two chains of nodes (chained through TREE_CHAIN)
1486 by modifying the last node in chain 1 to point to chain 2.
1487 This is the Lisp primitive `nconc'. */
1497 for (t = op1; TREE_CHAIN (t); t = TREE_CHAIN (t))
1498 if (t == op2) abort (); /* Circularity being created */
1499 if (t == op2) abort (); /* Circularity being created */
1500 TREE_CHAIN (t) = op2;
1506 /* Return the last node in a chain of nodes (chained through TREE_CHAIN). */
1510 register tree chain;
1514 while (next = TREE_CHAIN (chain))
1519 /* Reverse the order of elements in the chain T,
1520 and return the new head of the chain (old last element). */
1526 register tree prev = 0, decl, next;
1527 for (decl = t; decl; decl = next)
1529 next = TREE_CHAIN (decl);
1530 TREE_CHAIN (decl) = prev;
1536 /* Given a chain CHAIN of tree nodes,
1537 construct and return a list of those nodes. */
1543 tree result = NULL_TREE;
1544 tree in_tail = chain;
1545 tree out_tail = NULL_TREE;
1549 tree next = tree_cons (NULL_TREE, in_tail, NULL_TREE);
1551 TREE_CHAIN (out_tail) = next;
1555 in_tail = TREE_CHAIN (in_tail);
1561 /* Return a newly created TREE_LIST node whose
1562 purpose and value fields are PARM and VALUE. */
1565 build_tree_list (parm, value)
1568 register tree t = make_node (TREE_LIST);
1569 TREE_PURPOSE (t) = parm;
1570 TREE_VALUE (t) = value;
1574 /* Similar, but build on the temp_decl_obstack. */
1577 build_decl_list (parm, value)
1581 register struct obstack *ambient_obstack = current_obstack;
1582 current_obstack = &temp_decl_obstack;
1583 node = build_tree_list (parm, value);
1584 current_obstack = ambient_obstack;
1588 /* Return a newly created TREE_LIST node whose
1589 purpose and value fields are PARM and VALUE
1590 and whose TREE_CHAIN is CHAIN. */
1593 tree_cons (purpose, value, chain)
1594 tree purpose, value, chain;
1597 register tree node = make_node (TREE_LIST);
1600 register tree node = (tree) obstack_alloc (current_obstack, sizeof (struct tree_list));
1601 #ifdef GATHER_STATISTICS
1602 tree_node_counts[(int)x_kind]++;
1603 tree_node_sizes[(int)x_kind] += sizeof (struct tree_list);
1606 for (i = (sizeof (struct tree_common) / sizeof (int)) - 1; i >= 0; i--)
1607 ((int *) node)[i] = 0;
1609 TREE_SET_CODE (node, TREE_LIST);
1610 if (current_obstack == &permanent_obstack)
1611 TREE_PERMANENT (node) = 1;
1614 TREE_CHAIN (node) = chain;
1615 TREE_PURPOSE (node) = purpose;
1616 TREE_VALUE (node) = value;
1620 /* Similar, but build on the temp_decl_obstack. */
1623 decl_tree_cons (purpose, value, chain)
1624 tree purpose, value, chain;
1627 register struct obstack *ambient_obstack = current_obstack;
1628 current_obstack = &temp_decl_obstack;
1629 node = tree_cons (purpose, value, chain);
1630 current_obstack = ambient_obstack;
1634 /* Same as `tree_cons' but make a permanent object. */
1637 perm_tree_cons (purpose, value, chain)
1638 tree purpose, value, chain;
1641 register struct obstack *ambient_obstack = current_obstack;
1642 current_obstack = &permanent_obstack;
1644 node = tree_cons (purpose, value, chain);
1645 current_obstack = ambient_obstack;
1649 /* Same as `tree_cons', but make this node temporary, regardless. */
1652 temp_tree_cons (purpose, value, chain)
1653 tree purpose, value, chain;
1656 register struct obstack *ambient_obstack = current_obstack;
1657 current_obstack = &temporary_obstack;
1659 node = tree_cons (purpose, value, chain);
1660 current_obstack = ambient_obstack;
1664 /* Same as `tree_cons', but save this node if the function's RTL is saved. */
1667 saveable_tree_cons (purpose, value, chain)
1668 tree purpose, value, chain;
1671 register struct obstack *ambient_obstack = current_obstack;
1672 current_obstack = saveable_obstack;
1674 node = tree_cons (purpose, value, chain);
1675 current_obstack = ambient_obstack;
1679 /* Return the size nominally occupied by an object of type TYPE
1680 when it resides in memory. The value is measured in units of bytes,
1681 and its data type is that normally used for type sizes
1682 (which is the first type created by make_signed_type or
1683 make_unsigned_type). */
1686 size_in_bytes (type)
1691 if (type == error_mark_node)
1692 return integer_zero_node;
1693 type = TYPE_MAIN_VARIANT (type);
1694 if (TYPE_SIZE (type) == 0)
1696 incomplete_type_error (NULL_TREE, type);
1697 return integer_zero_node;
1699 t = size_binop (CEIL_DIV_EXPR, TYPE_SIZE (type),
1700 size_int (BITS_PER_UNIT));
1701 if (TREE_CODE (t) == INTEGER_CST)
1702 force_fit_type (t, 0);
1706 /* Return the size of TYPE (in bytes) as an integer,
1707 or return -1 if the size can vary. */
1710 int_size_in_bytes (type)
1714 if (type == error_mark_node)
1716 type = TYPE_MAIN_VARIANT (type);
1717 if (TYPE_SIZE (type) == 0)
1719 if (TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST)
1721 if (TREE_INT_CST_HIGH (TYPE_SIZE (type)) != 0)
1723 tree t = size_binop (CEIL_DIV_EXPR, TYPE_SIZE (type),
1724 size_int (BITS_PER_UNIT));
1725 return TREE_INT_CST_LOW (t);
1727 size = TREE_INT_CST_LOW (TYPE_SIZE (type));
1728 return (size + BITS_PER_UNIT - 1) / BITS_PER_UNIT;
1731 /* Return, as an INTEGER_CST node, the number of elements for
1732 TYPE (which is an ARRAY_TYPE) minus one.
1733 This counts only elements of the top array. */
1736 array_type_nelts (type)
1739 tree index_type = TYPE_DOMAIN (type);
1740 return (tree_int_cst_equal (TYPE_MIN_VALUE (index_type), integer_zero_node)
1741 ? TYPE_MAX_VALUE (index_type)
1742 : fold (build (MINUS_EXPR, integer_type_node,
1743 TYPE_MAX_VALUE (index_type),
1744 TYPE_MIN_VALUE (index_type))));
1747 /* Return nonzero if arg is static -- a reference to an object in
1748 static storage. This is not the same as the C meaning of `static'. */
1754 switch (TREE_CODE (arg))
1759 return TREE_STATIC (arg) || DECL_EXTERNAL (arg);
1766 return staticp (TREE_OPERAND (arg, 0));
1769 return TREE_CONSTANT (TREE_OPERAND (arg, 0));
1772 if (TREE_CODE (TYPE_SIZE (TREE_TYPE (arg))) == INTEGER_CST
1773 && TREE_CODE (TREE_OPERAND (arg, 1)) == INTEGER_CST)
1774 return staticp (TREE_OPERAND (arg, 0));
1780 /* This should be applied to any node which may be used in more than one place,
1781 but must be evaluated only once. Normally, the code generator would
1782 reevaluate the node each time; this forces it to compute it once and save
1783 the result. This is done by encapsulating the node in a SAVE_EXPR. */
1789 register tree t = fold (expr);
1791 /* We don't care about whether this can be used as an lvalue in this
1793 while (TREE_CODE (t) == NON_LVALUE_EXPR)
1794 t = TREE_OPERAND (t, 0);
1796 /* If the tree evaluates to a constant, then we don't want to hide that
1797 fact (i.e. this allows further folding, and direct checks for constants).
1798 However, a read-only object that has side effects cannot be bypassed.
1799 Since it is no problem to reevaluate literals, we just return the
1802 if (TREE_CONSTANT (t) || (TREE_READONLY (t) && ! TREE_SIDE_EFFECTS (t))
1803 || TREE_CODE (t) == SAVE_EXPR)
1806 t = build (SAVE_EXPR, TREE_TYPE (expr), t, current_function_decl, NULL_TREE);
1808 /* This expression might be placed ahead of a jump to ensure that the
1809 value was computed on both sides of the jump. So make sure it isn't
1810 eliminated as dead. */
1811 TREE_SIDE_EFFECTS (t) = 1;
1815 /* Stabilize a reference so that we can use it any number of times
1816 without causing its operands to be evaluated more than once.
1817 Returns the stabilized reference.
1819 Also allows conversion expressions whose operands are references.
1820 Any other kind of expression is returned unchanged. */
1823 stabilize_reference (ref)
1826 register tree result;
1827 register enum tree_code code = TREE_CODE (ref);
1834 /* No action is needed in this case. */
1840 case FIX_TRUNC_EXPR:
1841 case FIX_FLOOR_EXPR:
1842 case FIX_ROUND_EXPR:
1844 result = build_nt (code, stabilize_reference (TREE_OPERAND (ref, 0)));
1848 result = build_nt (INDIRECT_REF,
1849 stabilize_reference_1 (TREE_OPERAND (ref, 0)));
1853 result = build_nt (COMPONENT_REF,
1854 stabilize_reference (TREE_OPERAND (ref, 0)),
1855 TREE_OPERAND (ref, 1));
1859 result = build_nt (BIT_FIELD_REF,
1860 stabilize_reference (TREE_OPERAND (ref, 0)),
1861 stabilize_reference_1 (TREE_OPERAND (ref, 1)),
1862 stabilize_reference_1 (TREE_OPERAND (ref, 2)));
1866 result = build_nt (ARRAY_REF,
1867 stabilize_reference (TREE_OPERAND (ref, 0)),
1868 stabilize_reference_1 (TREE_OPERAND (ref, 1)));
1871 /* If arg isn't a kind of lvalue we recognize, make no change.
1872 Caller should recognize the error for an invalid lvalue. */
1877 return error_mark_node;
1880 TREE_TYPE (result) = TREE_TYPE (ref);
1881 TREE_READONLY (result) = TREE_READONLY (ref);
1882 TREE_SIDE_EFFECTS (result) = TREE_SIDE_EFFECTS (ref);
1883 TREE_THIS_VOLATILE (result) = TREE_THIS_VOLATILE (ref);
1884 TREE_RAISES (result) = TREE_RAISES (ref);
1889 /* Subroutine of stabilize_reference; this is called for subtrees of
1890 references. Any expression with side-effects must be put in a SAVE_EXPR
1891 to ensure that it is only evaluated once.
1893 We don't put SAVE_EXPR nodes around everything, because assigning very
1894 simple expressions to temporaries causes us to miss good opportunities
1895 for optimizations. Among other things, the opportunity to fold in the
1896 addition of a constant into an addressing mode often gets lost, e.g.
1897 "y[i+1] += x;". In general, we take the approach that we should not make
1898 an assignment unless we are forced into it - i.e., that any non-side effect
1899 operator should be allowed, and that cse should take care of coalescing
1900 multiple utterances of the same expression should that prove fruitful. */
1903 stabilize_reference_1 (e)
1906 register tree result;
1907 register int length;
1908 register enum tree_code code = TREE_CODE (e);
1910 /* We cannot ignore const expressions because it might be a reference
1911 to a const array but whose index contains side-effects. But we can
1912 ignore things that are actual constant or that already have been
1913 handled by this function. */
1915 if (TREE_CONSTANT (e) || code == SAVE_EXPR)
1918 switch (TREE_CODE_CLASS (code))
1928 /* If the expression has side-effects, then encase it in a SAVE_EXPR
1929 so that it will only be evaluated once. */
1930 /* The reference (r) and comparison (<) classes could be handled as
1931 below, but it is generally faster to only evaluate them once. */
1932 if (TREE_SIDE_EFFECTS (e))
1933 return save_expr (e);
1937 /* Constants need no processing. In fact, we should never reach
1942 /* Recursively stabilize each operand. */
1943 result = build_nt (code, stabilize_reference_1 (TREE_OPERAND (e, 0)),
1944 stabilize_reference_1 (TREE_OPERAND (e, 1)));
1948 /* Recursively stabilize each operand. */
1949 result = build_nt (code, stabilize_reference_1 (TREE_OPERAND (e, 0)));
1953 TREE_TYPE (result) = TREE_TYPE (e);
1954 TREE_READONLY (result) = TREE_READONLY (e);
1955 TREE_SIDE_EFFECTS (result) = TREE_SIDE_EFFECTS (e);
1956 TREE_THIS_VOLATILE (result) = TREE_THIS_VOLATILE (e);
1957 TREE_RAISES (result) = TREE_RAISES (e);
1962 /* Low-level constructors for expressions. */
1964 /* Build an expression of code CODE, data type TYPE,
1965 and operands as specified by the arguments ARG1 and following arguments.
1966 Expressions and reference nodes can be created this way.
1967 Constants, decls, types and misc nodes cannot be. */
1974 enum tree_code code;
1976 register int length;
1981 code = va_arg (p, enum tree_code);
1982 t = make_node (code);
1983 length = tree_code_length[(int) code];
1984 TREE_TYPE (t) = va_arg (p, tree);
1988 /* This is equivalent to the loop below, but faster. */
1989 register tree arg0 = va_arg (p, tree);
1990 register tree arg1 = va_arg (p, tree);
1991 TREE_OPERAND (t, 0) = arg0;
1992 TREE_OPERAND (t, 1) = arg1;
1993 if ((arg0 && TREE_SIDE_EFFECTS (arg0))
1994 || (arg1 && TREE_SIDE_EFFECTS (arg1)))
1995 TREE_SIDE_EFFECTS (t) = 1;
1997 = (arg0 && TREE_RAISES (arg0)) || (arg1 && TREE_RAISES (arg1));
1999 else if (length == 1)
2001 register tree arg0 = va_arg (p, tree);
2003 /* Call build1 for this! */
2004 if (TREE_CODE_CLASS (code) != 's')
2006 TREE_OPERAND (t, 0) = arg0;
2007 if (arg0 && TREE_SIDE_EFFECTS (arg0))
2008 TREE_SIDE_EFFECTS (t) = 1;
2009 TREE_RAISES (t) = (arg0 && TREE_RAISES (arg0));
2013 for (i = 0; i < length; i++)
2015 register tree operand = va_arg (p, tree);
2016 TREE_OPERAND (t, i) = operand;
2019 if (TREE_SIDE_EFFECTS (operand))
2020 TREE_SIDE_EFFECTS (t) = 1;
2021 if (TREE_RAISES (operand))
2022 TREE_RAISES (t) = 1;
2030 /* Same as above, but only builds for unary operators.
2031 Saves lions share of calls to `build'; cuts down use
2032 of varargs, which is expensive for RISC machines. */
2034 build1 (code, type, node)
2035 enum tree_code code;
2039 register struct obstack *obstack = current_obstack;
2040 register int i, length;
2041 register tree_node_kind kind;
2044 #ifdef GATHER_STATISTICS
2045 if (TREE_CODE_CLASS (code) == 'r')
2051 obstack = expression_obstack;
2052 length = sizeof (struct tree_exp);
2054 t = (tree) obstack_alloc (obstack, length);
2056 #ifdef GATHER_STATISTICS
2057 tree_node_counts[(int)kind]++;
2058 tree_node_sizes[(int)kind] += length;
2061 for (i = (length / sizeof (int)) - 1; i >= 0; i--)
2064 TREE_TYPE (t) = type;
2065 TREE_SET_CODE (t, code);
2067 if (obstack == &permanent_obstack)
2068 TREE_PERMANENT (t) = 1;
2070 TREE_OPERAND (t, 0) = node;
2073 if (TREE_SIDE_EFFECTS (node))
2074 TREE_SIDE_EFFECTS (t) = 1;
2075 if (TREE_RAISES (node))
2076 TREE_RAISES (t) = 1;
2082 /* Similar except don't specify the TREE_TYPE
2083 and leave the TREE_SIDE_EFFECTS as 0.
2084 It is permissible for arguments to be null,
2085 or even garbage if their values do not matter. */
2092 register enum tree_code code;
2094 register int length;
2099 code = va_arg (p, enum tree_code);
2100 t = make_node (code);
2101 length = tree_code_length[(int) code];
2103 for (i = 0; i < length; i++)
2104 TREE_OPERAND (t, i) = va_arg (p, tree);
2110 /* Similar to `build_nt', except we build
2111 on the temp_decl_obstack, regardless. */
2114 build_parse_node (va_alist)
2117 register struct obstack *ambient_obstack = expression_obstack;
2119 register enum tree_code code;
2121 register int length;
2124 expression_obstack = &temp_decl_obstack;
2128 code = va_arg (p, enum tree_code);
2129 t = make_node (code);
2130 length = tree_code_length[(int) code];
2132 for (i = 0; i < length; i++)
2133 TREE_OPERAND (t, i) = va_arg (p, tree);
2136 expression_obstack = ambient_obstack;
2141 /* Commented out because this wants to be done very
2142 differently. See cp-lex.c. */
2144 build_op_identifier (op1, op2)
2147 register tree t = make_node (OP_IDENTIFIER);
2148 TREE_PURPOSE (t) = op1;
2149 TREE_VALUE (t) = op2;
2154 /* Create a DECL_... node of code CODE, name NAME and data type TYPE.
2155 We do NOT enter this node in any sort of symbol table.
2157 layout_decl is used to set up the decl's storage layout.
2158 Other slots are initialized to 0 or null pointers. */
2161 build_decl (code, name, type)
2162 enum tree_code code;
2167 t = make_node (code);
2169 /* if (type == error_mark_node)
2170 type = integer_type_node; */
2171 /* That is not done, deliberately, so that having error_mark_node
2172 as the type can suppress useless errors in the use of this variable. */
2174 DECL_NAME (t) = name;
2175 DECL_ASSEMBLER_NAME (t) = name;
2176 TREE_TYPE (t) = type;
2178 if (code == VAR_DECL || code == PARM_DECL || code == RESULT_DECL)
2180 else if (code == FUNCTION_DECL)
2181 DECL_MODE (t) = FUNCTION_MODE;
2186 /* BLOCK nodes are used to represent the structure of binding contours
2187 and declarations, once those contours have been exited and their contents
2188 compiled. This information is used for outputting debugging info. */
2191 build_block (vars, tags, subblocks, supercontext, chain)
2192 tree vars, tags, subblocks, supercontext, chain;
2194 register tree block = make_node (BLOCK);
2195 BLOCK_VARS (block) = vars;
2196 BLOCK_TYPE_TAGS (block) = tags;
2197 BLOCK_SUBBLOCKS (block) = subblocks;
2198 BLOCK_SUPERCONTEXT (block) = supercontext;
2199 BLOCK_CHAIN (block) = chain;
2203 /* Return a type like TYPE except that its TYPE_READONLY is CONSTP
2204 and its TYPE_VOLATILE is VOLATILEP.
2206 Such variant types already made are recorded so that duplicates
2209 A variant types should never be used as the type of an expression.
2210 Always copy the variant information into the TREE_READONLY
2211 and TREE_THIS_VOLATILE of the expression, and then give the expression
2212 as its type the "main variant", the variant whose TYPE_READONLY
2213 and TYPE_VOLATILE are zero. Use TYPE_MAIN_VARIANT to find the
2217 build_type_variant (type, constp, volatilep)
2219 int constp, volatilep;
2221 register tree t, m = TYPE_MAIN_VARIANT (type);
2222 register struct obstack *ambient_obstack = current_obstack;
2224 /* Treat any nonzero argument as 1. */
2226 volatilep = !!volatilep;
2228 /* If not generating auxiliary info, search the chain of variants to see
2229 if there is already one there just like the one we need to have. If so,
2230 use that existing one.
2232 We don't do this in the case where we are generating aux info because
2233 in that case we want each typedef names to get it's own distinct type
2234 node, even if the type of this new typedef is the same as some other
2237 if (!flag_gen_aux_info)
2238 for (t = m; t; t = TYPE_NEXT_VARIANT (t))
2239 if (constp == TYPE_READONLY (t) && volatilep == TYPE_VOLATILE (t))
2242 /* We need a new one. */
2244 = TREE_PERMANENT (type) ? &permanent_obstack : saveable_obstack;
2246 t = copy_node (type);
2247 TYPE_READONLY (t) = constp;
2248 TYPE_VOLATILE (t) = volatilep;
2249 TYPE_POINTER_TO (t) = 0;
2250 TYPE_REFERENCE_TO (t) = 0;
2252 /* Add this type to the chain of variants of TYPE. */
2253 TYPE_NEXT_VARIANT (t) = TYPE_NEXT_VARIANT (m);
2254 TYPE_NEXT_VARIANT (m) = t;
2256 current_obstack = ambient_obstack;
2260 /* Create a new variant of TYPE, equivalent but distinct.
2261 This is so the caller can modify it. */
2264 build_type_copy (type)
2267 register tree t, m = TYPE_MAIN_VARIANT (type);
2268 register struct obstack *ambient_obstack = current_obstack;
2271 = TREE_PERMANENT (type) ? &permanent_obstack : saveable_obstack;
2273 t = copy_node (type);
2274 TYPE_POINTER_TO (t) = 0;
2275 TYPE_REFERENCE_TO (t) = 0;
2277 /* Add this type to the chain of variants of TYPE. */
2278 TYPE_NEXT_VARIANT (t) = TYPE_NEXT_VARIANT (m);
2279 TYPE_NEXT_VARIANT (m) = t;
2281 current_obstack = ambient_obstack;
2285 /* Hashing of types so that we don't make duplicates.
2286 The entry point is `type_hash_canon'. */
2288 /* Each hash table slot is a bucket containing a chain
2289 of these structures. */
2293 struct type_hash *next; /* Next structure in the bucket. */
2294 int hashcode; /* Hash code of this type. */
2295 tree type; /* The type recorded here. */
2298 /* Now here is the hash table. When recording a type, it is added
2299 to the slot whose index is the hash code mod the table size.
2300 Note that the hash table is used for several kinds of types
2301 (function types, array types and array index range types, for now).
2302 While all these live in the same table, they are completely independent,
2303 and the hash code is computed differently for each of these. */
2305 #define TYPE_HASH_SIZE 59
2306 struct type_hash *type_hash_table[TYPE_HASH_SIZE];
2308 /* Here is how primitive or already-canonicalized types' hash
2310 #define TYPE_HASH(TYPE) ((HOST_WIDE_INT) (TYPE) & 0777777)
2312 /* Compute a hash code for a list of types (chain of TREE_LIST nodes
2313 with types in the TREE_VALUE slots), by adding the hash codes
2314 of the individual types. */
2317 type_hash_list (list)
2320 register int hashcode;
2322 for (hashcode = 0, tail = list; tail; tail = TREE_CHAIN (tail))
2323 hashcode += TYPE_HASH (TREE_VALUE (tail));
2327 /* Look in the type hash table for a type isomorphic to TYPE.
2328 If one is found, return it. Otherwise return 0. */
2331 type_hash_lookup (hashcode, type)
2335 register struct type_hash *h;
2336 for (h = type_hash_table[hashcode % TYPE_HASH_SIZE]; h; h = h->next)
2337 if (h->hashcode == hashcode
2338 && TREE_CODE (h->type) == TREE_CODE (type)
2339 && TREE_TYPE (h->type) == TREE_TYPE (type)
2340 && (TYPE_MAX_VALUE (h->type) == TYPE_MAX_VALUE (type)
2341 || tree_int_cst_equal (TYPE_MAX_VALUE (h->type),
2342 TYPE_MAX_VALUE (type)))
2343 && (TYPE_MIN_VALUE (h->type) == TYPE_MIN_VALUE (type)
2344 || tree_int_cst_equal (TYPE_MIN_VALUE (h->type),
2345 TYPE_MIN_VALUE (type)))
2346 && (TYPE_DOMAIN (h->type) == TYPE_DOMAIN (type)
2347 || (TYPE_DOMAIN (h->type)
2348 && TREE_CODE (TYPE_DOMAIN (h->type)) == TREE_LIST
2349 && TYPE_DOMAIN (type)
2350 && TREE_CODE (TYPE_DOMAIN (type)) == TREE_LIST
2351 && type_list_equal (TYPE_DOMAIN (h->type), TYPE_DOMAIN (type)))))
2356 /* Add an entry to the type-hash-table
2357 for a type TYPE whose hash code is HASHCODE. */
2360 type_hash_add (hashcode, type)
2364 register struct type_hash *h;
2366 h = (struct type_hash *) oballoc (sizeof (struct type_hash));
2367 h->hashcode = hashcode;
2369 h->next = type_hash_table[hashcode % TYPE_HASH_SIZE];
2370 type_hash_table[hashcode % TYPE_HASH_SIZE] = h;
2373 /* Given TYPE, and HASHCODE its hash code, return the canonical
2374 object for an identical type if one already exists.
2375 Otherwise, return TYPE, and record it as the canonical object
2376 if it is a permanent object.
2378 To use this function, first create a type of the sort you want.
2379 Then compute its hash code from the fields of the type that
2380 make it different from other similar types.
2381 Then call this function and use the value.
2382 This function frees the type you pass in if it is a duplicate. */
2384 /* Set to 1 to debug without canonicalization. Never set by program. */
2385 int debug_no_type_hash = 0;
2388 type_hash_canon (hashcode, type)
2394 if (debug_no_type_hash)
2397 t1 = type_hash_lookup (hashcode, type);
2401 = TREE_PERMANENT (type) ? &permanent_obstack : saveable_obstack;
2402 obstack_free (o, type);
2403 #ifdef GATHER_STATISTICS
2404 tree_node_counts[(int)t_kind]--;
2405 tree_node_sizes[(int)t_kind] -= sizeof (struct tree_type);
2410 /* If this is a new type, record it for later reuse. */
2411 if (current_obstack == &permanent_obstack)
2412 type_hash_add (hashcode, type);
2417 /* Given two lists of types
2418 (chains of TREE_LIST nodes with types in the TREE_VALUE slots)
2419 return 1 if the lists contain the same types in the same order.
2420 Also, the TREE_PURPOSEs must match. */
2423 type_list_equal (l1, l2)
2426 register tree t1, t2;
2427 for (t1 = l1, t2 = l2; t1 && t2; t1 = TREE_CHAIN (t1), t2 = TREE_CHAIN (t2))
2429 if (TREE_VALUE (t1) != TREE_VALUE (t2))
2431 if (TREE_PURPOSE (t1) != TREE_PURPOSE (t2))
2433 int cmp = simple_cst_equal (TREE_PURPOSE (t1), TREE_PURPOSE (t2));
2444 /* Nonzero if integer constants T1 and T2
2445 represent the same constant value. */
2448 tree_int_cst_equal (t1, t2)
2453 if (t1 == 0 || t2 == 0)
2455 if (TREE_CODE (t1) == INTEGER_CST
2456 && TREE_CODE (t2) == INTEGER_CST
2457 && TREE_INT_CST_LOW (t1) == TREE_INT_CST_LOW (t2)
2458 && TREE_INT_CST_HIGH (t1) == TREE_INT_CST_HIGH (t2))
2463 /* Nonzero if integer constants T1 and T2 represent values that satisfy <.
2464 The precise way of comparison depends on their data type. */
2467 tree_int_cst_lt (t1, t2)
2473 if (!TREE_UNSIGNED (TREE_TYPE (t1)))
2474 return INT_CST_LT (t1, t2);
2475 return INT_CST_LT_UNSIGNED (t1, t2);
2478 /* Compare two constructor-element-type constants. */
2480 simple_cst_list_equal (l1, l2)
2483 while (l1 != NULL_TREE && l2 != NULL_TREE)
2485 int cmp = simple_cst_equal (TREE_VALUE (l1), TREE_VALUE (l2));
2490 l1 = TREE_CHAIN (l1);
2491 l2 = TREE_CHAIN (l2);
2496 /* Return truthvalue of whether T1 is the same tree structure as T2.
2497 Return 1 if they are the same.
2498 Return 0 if they are understandably different.
2499 Return -1 if either contains tree structure not understood by
2503 simple_cst_equal (t1, t2)
2506 register enum tree_code code1, code2;
2511 if (t1 == 0 || t2 == 0)
2514 code1 = TREE_CODE (t1);
2515 code2 = TREE_CODE (t2);
2517 if (code1 == NOP_EXPR || code1 == CONVERT_EXPR || code1 == NON_LVALUE_EXPR)
2518 if (code2 == NOP_EXPR || code2 == CONVERT_EXPR || code2 == NON_LVALUE_EXPR)
2519 return simple_cst_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
2521 return simple_cst_equal (TREE_OPERAND (t1, 0), t2);
2522 else if (code2 == NOP_EXPR || code2 == CONVERT_EXPR
2523 || code2 == NON_LVALUE_EXPR)
2524 return simple_cst_equal (t1, TREE_OPERAND (t2, 0));
2532 return TREE_INT_CST_LOW (t1) == TREE_INT_CST_LOW (t2)
2533 && TREE_INT_CST_HIGH (t1) == TREE_INT_CST_HIGH (t2);
2536 return REAL_VALUES_EQUAL (TREE_REAL_CST (t1), TREE_REAL_CST (t2));
2539 return TREE_STRING_LENGTH (t1) == TREE_STRING_LENGTH (t2)
2540 && !bcmp (TREE_STRING_POINTER (t1), TREE_STRING_POINTER (t2),
2541 TREE_STRING_LENGTH (t1));
2547 return simple_cst_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
2550 cmp = simple_cst_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
2553 return simple_cst_list_equal (TREE_OPERAND (t1, 1), TREE_OPERAND (t2, 1));
2556 /* Special case: if either target is an unallocated VAR_DECL,
2557 it means that it's going to be unified with whatever the
2558 TARGET_EXPR is really supposed to initialize, so treat it
2559 as being equivalent to anything. */
2560 if ((TREE_CODE (TREE_OPERAND (t1, 0)) == VAR_DECL
2561 && DECL_NAME (TREE_OPERAND (t1, 0)) == NULL_TREE
2562 && DECL_RTL (TREE_OPERAND (t1, 0)) == 0)
2563 || (TREE_CODE (TREE_OPERAND (t2, 0)) == VAR_DECL
2564 && DECL_NAME (TREE_OPERAND (t2, 0)) == NULL_TREE
2565 && DECL_RTL (TREE_OPERAND (t2, 0)) == 0))
2568 cmp = simple_cst_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
2571 return simple_cst_equal (TREE_OPERAND (t1, 1), TREE_OPERAND (t2, 1));
2573 case WITH_CLEANUP_EXPR:
2574 cmp = simple_cst_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
2577 return simple_cst_equal (TREE_OPERAND (t1, 2), TREE_OPERAND (t1, 2));
2580 if (TREE_OPERAND (t1, 1) == TREE_OPERAND (t2, 1))
2581 return simple_cst_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
2591 /* This general rule works for most tree codes.
2592 All exceptions should be handled above. */
2594 switch (TREE_CODE_CLASS (code1))
2604 for (i=0; i<tree_code_length[(int) code1]; ++i)
2606 cmp = simple_cst_equal (TREE_OPERAND (t1, i), TREE_OPERAND (t2, i));
2616 /* Constructors for pointer, array and function types.
2617 (RECORD_TYPE, UNION_TYPE and ENUMERAL_TYPE nodes are
2618 constructed by language-dependent code, not here.) */
2620 /* Construct, lay out and return the type of pointers to TO_TYPE.
2621 If such a type has already been constructed, reuse it. */
2624 build_pointer_type (to_type)
2627 register tree t = TYPE_POINTER_TO (to_type);
2628 register struct obstack *ambient_obstack = current_obstack;
2629 register struct obstack *ambient_saveable_obstack = saveable_obstack;
2631 /* First, if we already have a type for pointers to TO_TYPE, use it. */
2636 /* We need a new one. If TO_TYPE is permanent, make this permanent too. */
2637 if (TREE_PERMANENT (to_type))
2639 current_obstack = &permanent_obstack;
2640 saveable_obstack = &permanent_obstack;
2643 t = make_node (POINTER_TYPE);
2644 TREE_TYPE (t) = to_type;
2646 /* Record this type as the pointer to TO_TYPE. */
2647 TYPE_POINTER_TO (to_type) = t;
2649 /* Lay out the type. This function has many callers that are concerned
2650 with expression-construction, and this simplifies them all.
2651 Also, it guarantees the TYPE_SIZE is permanent if the type is. */
2654 current_obstack = ambient_obstack;
2655 saveable_obstack = ambient_saveable_obstack;
2659 /* Create a type of integers to be the TYPE_DOMAIN of an ARRAY_TYPE.
2660 MAXVAL should be the maximum value in the domain
2661 (one less than the length of the array). */
2664 build_index_type (maxval)
2667 register tree itype = make_node (INTEGER_TYPE);
2668 TYPE_PRECISION (itype) = TYPE_PRECISION (sizetype);
2669 TYPE_MIN_VALUE (itype) = build_int_2 (0, 0);
2670 TREE_TYPE (TYPE_MIN_VALUE (itype)) = sizetype;
2671 TYPE_MAX_VALUE (itype) = convert (sizetype, maxval);
2672 TYPE_MODE (itype) = TYPE_MODE (sizetype);
2673 TYPE_SIZE (itype) = TYPE_SIZE (sizetype);
2674 TYPE_ALIGN (itype) = TYPE_ALIGN (sizetype);
2675 if (TREE_CODE (maxval) == INTEGER_CST)
2677 int maxint = (int) TREE_INT_CST_LOW (maxval);
2678 /* If the domain should be empty, make sure the maxval
2679 remains -1 and is not spoiled by truncation. */
2680 if (INT_CST_LT (maxval, integer_zero_node))
2682 TYPE_MAX_VALUE (itype) = build_int_2 (-1, -1);
2683 TREE_TYPE (TYPE_MAX_VALUE (itype)) = sizetype;
2685 return type_hash_canon (maxint < 0 ? ~maxint : maxint, itype);
2691 /* Just like build_index_type, but takes lowval and highval instead
2692 of just highval (maxval). */
2695 build_index_2_type (lowval,highval)
2696 tree lowval, highval;
2698 register tree itype = make_node (INTEGER_TYPE);
2699 TYPE_PRECISION (itype) = TYPE_PRECISION (sizetype);
2700 TYPE_MIN_VALUE (itype) = convert (sizetype, lowval);
2701 TYPE_MAX_VALUE (itype) = convert (sizetype, highval);
2702 TYPE_MODE (itype) = TYPE_MODE (sizetype);
2703 TYPE_SIZE (itype) = TYPE_SIZE (sizetype);
2704 TYPE_ALIGN (itype) = TYPE_ALIGN (sizetype);
2705 if ((TREE_CODE (lowval) == INTEGER_CST)
2706 && (TREE_CODE (highval) == INTEGER_CST))
2708 HOST_WIDE_INT highint = TREE_INT_CST_LOW (highval);
2709 HOST_WIDE_INT lowint = TREE_INT_CST_LOW (lowval);
2710 int maxint = (int) (highint - lowint);
2711 return type_hash_canon (maxint < 0 ? ~maxint : maxint, itype);
2717 /* Return nonzero iff ITYPE1 and ITYPE2 are equal (in the LISP sense).
2718 Needed because when index types are not hashed, equal index types
2719 built at different times appear distinct, even though structurally,
2723 index_type_equal (itype1, itype2)
2724 tree itype1, itype2;
2726 if (TREE_CODE (itype1) != TREE_CODE (itype2))
2728 if (TREE_CODE (itype1) == INTEGER_TYPE)
2730 if (TYPE_PRECISION (itype1) != TYPE_PRECISION (itype2)
2731 || TYPE_MODE (itype1) != TYPE_MODE (itype2)
2732 || ! simple_cst_equal (TYPE_SIZE (itype1), TYPE_SIZE (itype2))
2733 || TYPE_ALIGN (itype1) != TYPE_ALIGN (itype2))
2735 if (simple_cst_equal (TYPE_MIN_VALUE (itype1), TYPE_MIN_VALUE (itype2))
2736 && simple_cst_equal (TYPE_MAX_VALUE (itype1), TYPE_MAX_VALUE (itype2)))
2742 /* Construct, lay out and return the type of arrays of elements with ELT_TYPE
2743 and number of elements specified by the range of values of INDEX_TYPE.
2744 If such a type has already been constructed, reuse it. */
2747 build_array_type (elt_type, index_type)
2748 tree elt_type, index_type;
2753 if (TREE_CODE (elt_type) == FUNCTION_TYPE)
2755 error ("arrays of functions are not meaningful");
2756 elt_type = integer_type_node;
2759 /* Make sure TYPE_POINTER_TO (elt_type) is filled in. */
2760 build_pointer_type (elt_type);
2762 /* Allocate the array after the pointer type,
2763 in case we free it in type_hash_canon. */
2764 t = make_node (ARRAY_TYPE);
2765 TREE_TYPE (t) = elt_type;
2766 TYPE_DOMAIN (t) = index_type;
2768 if (index_type == 0)
2771 hashcode = TYPE_HASH (elt_type) + TYPE_HASH (index_type);
2772 t = type_hash_canon (hashcode, t);
2774 if (TYPE_SIZE (t) == 0)
2779 /* Construct, lay out and return
2780 the type of functions returning type VALUE_TYPE
2781 given arguments of types ARG_TYPES.
2782 ARG_TYPES is a chain of TREE_LIST nodes whose TREE_VALUEs
2783 are data type nodes for the arguments of the function.
2784 If such a type has already been constructed, reuse it. */
2787 build_function_type (value_type, arg_types)
2788 tree value_type, arg_types;
2793 if (TREE_CODE (value_type) == FUNCTION_TYPE
2794 || TREE_CODE (value_type) == ARRAY_TYPE)
2796 error ("function return type cannot be function or array");
2797 value_type = integer_type_node;
2800 /* Make a node of the sort we want. */
2801 t = make_node (FUNCTION_TYPE);
2802 TREE_TYPE (t) = value_type;
2803 TYPE_ARG_TYPES (t) = arg_types;
2805 /* If we already have such a type, use the old one and free this one. */
2806 hashcode = TYPE_HASH (value_type) + type_hash_list (arg_types);
2807 t = type_hash_canon (hashcode, t);
2809 if (TYPE_SIZE (t) == 0)
2814 /* Build the node for the type of references-to-TO_TYPE. */
2817 build_reference_type (to_type)
2820 register tree t = TYPE_REFERENCE_TO (to_type);
2821 register struct obstack *ambient_obstack = current_obstack;
2822 register struct obstack *ambient_saveable_obstack = saveable_obstack;
2824 /* First, if we already have a type for pointers to TO_TYPE, use it. */
2829 /* We need a new one. If TO_TYPE is permanent, make this permanent too. */
2830 if (TREE_PERMANENT (to_type))
2832 current_obstack = &permanent_obstack;
2833 saveable_obstack = &permanent_obstack;
2836 t = make_node (REFERENCE_TYPE);
2837 TREE_TYPE (t) = to_type;
2839 /* Record this type as the pointer to TO_TYPE. */
2840 TYPE_REFERENCE_TO (to_type) = t;
2844 current_obstack = ambient_obstack;
2845 saveable_obstack = ambient_saveable_obstack;
2849 /* Construct, lay out and return the type of methods belonging to class
2850 BASETYPE and whose arguments and values are described by TYPE.
2851 If that type exists already, reuse it.
2852 TYPE must be a FUNCTION_TYPE node. */
2855 build_method_type (basetype, type)
2856 tree basetype, type;
2861 /* Make a node of the sort we want. */
2862 t = make_node (METHOD_TYPE);
2864 if (TREE_CODE (type) != FUNCTION_TYPE)
2867 TYPE_METHOD_BASETYPE (t) = TYPE_MAIN_VARIANT (basetype);
2868 TREE_TYPE (t) = TREE_TYPE (type);
2870 /* The actual arglist for this function includes a "hidden" argument
2871 which is "this". Put it into the list of argument types. */
2874 = tree_cons (NULL_TREE,
2875 build_pointer_type (basetype), TYPE_ARG_TYPES (type));
2877 /* If we already have such a type, use the old one and free this one. */
2878 hashcode = TYPE_HASH (basetype) + TYPE_HASH (type);
2879 t = type_hash_canon (hashcode, t);
2881 if (TYPE_SIZE (t) == 0)
2887 /* Construct, lay out and return the type of offsets to a value
2888 of type TYPE, within an object of type BASETYPE.
2889 If a suitable offset type exists already, reuse it. */
2892 build_offset_type (basetype, type)
2893 tree basetype, type;
2898 /* Make a node of the sort we want. */
2899 t = make_node (OFFSET_TYPE);
2901 TYPE_OFFSET_BASETYPE (t) = TYPE_MAIN_VARIANT (basetype);
2902 TREE_TYPE (t) = type;
2904 /* If we already have such a type, use the old one and free this one. */
2905 hashcode = TYPE_HASH (basetype) + TYPE_HASH (type);
2906 t = type_hash_canon (hashcode, t);
2908 if (TYPE_SIZE (t) == 0)
2914 /* Create a complex type whose components are COMPONENT_TYPE. */
2917 build_complex_type (component_type)
2918 tree component_type;
2923 /* Make a node of the sort we want. */
2924 t = make_node (COMPLEX_TYPE);
2926 TREE_TYPE (t) = TYPE_MAIN_VARIANT (component_type);
2927 TYPE_VOLATILE (t) = TYPE_VOLATILE (component_type);
2928 TYPE_READONLY (t) = TYPE_READONLY (component_type);
2930 /* If we already have such a type, use the old one and free this one. */
2931 hashcode = TYPE_HASH (component_type);
2932 t = type_hash_canon (hashcode, t);
2934 if (TYPE_SIZE (t) == 0)
2940 /* Return OP, stripped of any conversions to wider types as much as is safe.
2941 Converting the value back to OP's type makes a value equivalent to OP.
2943 If FOR_TYPE is nonzero, we return a value which, if converted to
2944 type FOR_TYPE, would be equivalent to converting OP to type FOR_TYPE.
2946 If FOR_TYPE is nonzero, unaligned bit-field references may be changed to the
2947 narrowest type that can hold the value, even if they don't exactly fit.
2948 Otherwise, bit-field references are changed to a narrower type
2949 only if they can be fetched directly from memory in that type.
2951 OP must have integer, real or enumeral type. Pointers are not allowed!
2953 There are some cases where the obvious value we could return
2954 would regenerate to OP if converted to OP's type,
2955 but would not extend like OP to wider types.
2956 If FOR_TYPE indicates such extension is contemplated, we eschew such values.
2957 For example, if OP is (unsigned short)(signed char)-1,
2958 we avoid returning (signed char)-1 if FOR_TYPE is int,
2959 even though extending that to an unsigned short would regenerate OP,
2960 since the result of extending (signed char)-1 to (int)
2961 is different from (int) OP. */
2964 get_unwidened (op, for_type)
2968 /* Set UNS initially if converting OP to FOR_TYPE is a zero-extension. */
2969 /* TYPE_PRECISION is safe in place of type_precision since
2970 pointer types are not allowed. */
2971 register tree type = TREE_TYPE (op);
2972 register unsigned final_prec
2973 = TYPE_PRECISION (for_type != 0 ? for_type : type);
2975 = (for_type != 0 && for_type != type
2976 && final_prec > TYPE_PRECISION (type)
2977 && TREE_UNSIGNED (type));
2978 register tree win = op;
2980 while (TREE_CODE (op) == NOP_EXPR)
2982 register int bitschange
2983 = TYPE_PRECISION (TREE_TYPE (op))
2984 - TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (op, 0)));
2986 /* Truncations are many-one so cannot be removed.
2987 Unless we are later going to truncate down even farther. */
2989 && final_prec > TYPE_PRECISION (TREE_TYPE (op)))
2992 /* See what's inside this conversion. If we decide to strip it,
2994 op = TREE_OPERAND (op, 0);
2996 /* If we have not stripped any zero-extensions (uns is 0),
2997 we can strip any kind of extension.
2998 If we have previously stripped a zero-extension,
2999 only zero-extensions can safely be stripped.
3000 Any extension can be stripped if the bits it would produce
3001 are all going to be discarded later by truncating to FOR_TYPE. */
3005 if (! uns || final_prec <= TYPE_PRECISION (TREE_TYPE (op)))
3007 /* TREE_UNSIGNED says whether this is a zero-extension.
3008 Let's avoid computing it if it does not affect WIN
3009 and if UNS will not be needed again. */
3010 if ((uns || TREE_CODE (op) == NOP_EXPR)
3011 && TREE_UNSIGNED (TREE_TYPE (op)))
3019 if (TREE_CODE (op) == COMPONENT_REF
3020 /* Since type_for_size always gives an integer type. */
3021 && TREE_CODE (type) != REAL_TYPE)
3023 unsigned innerprec = TREE_INT_CST_LOW (DECL_SIZE (TREE_OPERAND (op, 1)));
3024 type = type_for_size (innerprec, TREE_UNSIGNED (TREE_OPERAND (op, 1)));
3026 /* We can get this structure field in the narrowest type it fits in.
3027 If FOR_TYPE is 0, do this only for a field that matches the
3028 narrower type exactly and is aligned for it
3029 The resulting extension to its nominal type (a fullword type)
3030 must fit the same conditions as for other extensions. */
3032 if (innerprec < TYPE_PRECISION (TREE_TYPE (op))
3033 && (for_type || ! DECL_BIT_FIELD (TREE_OPERAND (op, 1)))
3034 && (! uns || final_prec <= innerprec
3035 || TREE_UNSIGNED (TREE_OPERAND (op, 1)))
3038 win = build (COMPONENT_REF, type, TREE_OPERAND (op, 0),
3039 TREE_OPERAND (op, 1));
3040 TREE_SIDE_EFFECTS (win) = TREE_SIDE_EFFECTS (op);
3041 TREE_THIS_VOLATILE (win) = TREE_THIS_VOLATILE (op);
3042 TREE_RAISES (win) = TREE_RAISES (op);
3048 /* Return OP or a simpler expression for a narrower value
3049 which can be sign-extended or zero-extended to give back OP.
3050 Store in *UNSIGNEDP_PTR either 1 if the value should be zero-extended
3051 or 0 if the value should be sign-extended. */
3054 get_narrower (op, unsignedp_ptr)
3058 register int uns = 0;
3060 register tree win = op;
3062 while (TREE_CODE (op) == NOP_EXPR)
3064 register int bitschange
3065 = TYPE_PRECISION (TREE_TYPE (op))
3066 - TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (op, 0)));
3068 /* Truncations are many-one so cannot be removed. */
3072 /* See what's inside this conversion. If we decide to strip it,
3074 op = TREE_OPERAND (op, 0);
3078 /* An extension: the outermost one can be stripped,
3079 but remember whether it is zero or sign extension. */
3081 uns = TREE_UNSIGNED (TREE_TYPE (op));
3082 /* Otherwise, if a sign extension has been stripped,
3083 only sign extensions can now be stripped;
3084 if a zero extension has been stripped, only zero-extensions. */
3085 else if (uns != TREE_UNSIGNED (TREE_TYPE (op)))
3089 /* A change in nominal type can always be stripped. */
3094 if (TREE_CODE (op) == COMPONENT_REF
3095 /* Since type_for_size always gives an integer type. */
3096 && TREE_CODE (TREE_TYPE (op)) != REAL_TYPE)
3098 unsigned innerprec = TREE_INT_CST_LOW (DECL_SIZE (TREE_OPERAND (op, 1)));
3099 tree type = type_for_size (innerprec, TREE_UNSIGNED (op));
3101 /* We can get this structure field in a narrower type that fits it,
3102 but the resulting extension to its nominal type (a fullword type)
3103 must satisfy the same conditions as for other extensions.
3105 Do this only for fields that are aligned (not bit-fields),
3106 because when bit-field insns will be used there is no
3107 advantage in doing this. */
3109 if (innerprec < TYPE_PRECISION (TREE_TYPE (op))
3110 && ! DECL_BIT_FIELD (TREE_OPERAND (op, 1))
3111 && (first || uns == TREE_UNSIGNED (TREE_OPERAND (op, 1)))
3115 uns = TREE_UNSIGNED (TREE_OPERAND (op, 1));
3116 win = build (COMPONENT_REF, type, TREE_OPERAND (op, 0),
3117 TREE_OPERAND (op, 1));
3118 TREE_SIDE_EFFECTS (win) = TREE_SIDE_EFFECTS (op);
3119 TREE_THIS_VOLATILE (win) = TREE_THIS_VOLATILE (op);
3120 TREE_RAISES (win) = TREE_RAISES (op);
3123 *unsignedp_ptr = uns;
3127 /* Return the precision of a type, for arithmetic purposes.
3128 Supports all types on which arithmetic is possible
3129 (including pointer types).
3130 It's not clear yet what will be right for complex types. */
3133 type_precision (type)
3136 return ((TREE_CODE (type) == INTEGER_TYPE
3137 || TREE_CODE (type) == ENUMERAL_TYPE
3138 || TREE_CODE (type) == REAL_TYPE)
3139 ? TYPE_PRECISION (type) : POINTER_SIZE);
3142 /* Nonzero if integer constant C has a value that is permissible
3143 for type TYPE (an INTEGER_TYPE). */
3146 int_fits_type_p (c, type)
3149 if (TREE_UNSIGNED (type))
3150 return (!INT_CST_LT_UNSIGNED (TYPE_MAX_VALUE (type), c)
3151 && !INT_CST_LT_UNSIGNED (c, TYPE_MIN_VALUE (type))
3152 && (TREE_INT_CST_HIGH (c) >= 0 || TREE_UNSIGNED (TREE_TYPE (c))));
3154 return (!INT_CST_LT (TYPE_MAX_VALUE (type), c)
3155 && !INT_CST_LT (c, TYPE_MIN_VALUE (type))
3156 && (TREE_INT_CST_HIGH (c) >= 0 || !TREE_UNSIGNED (TREE_TYPE (c))));
3159 /* Return the innermost context enclosing DECL that is
3160 a FUNCTION_DECL, or zero if none. */
3163 decl_function_context (decl)
3168 if (TREE_CODE (decl) == ERROR_MARK)
3171 if (TREE_CODE (decl) == SAVE_EXPR)
3172 context = SAVE_EXPR_CONTEXT (decl);
3174 context = DECL_CONTEXT (decl);
3176 while (context && TREE_CODE (context) != FUNCTION_DECL)
3178 if (TREE_CODE (context) == RECORD_TYPE
3179 || TREE_CODE (context) == UNION_TYPE)
3180 context = TYPE_CONTEXT (context);
3181 else if (TREE_CODE (context) == TYPE_DECL)
3182 context = DECL_CONTEXT (context);
3183 else if (TREE_CODE (context) == BLOCK)
3184 context = BLOCK_SUPERCONTEXT (context);
3186 /* Unhandled CONTEXT !? */
3193 /* Return the innermost context enclosing DECL that is
3194 a RECORD_TYPE or UNION_TYPE, or zero if none.
3195 TYPE_DECLs and FUNCTION_DECLs are transparent to this function. */
3198 decl_type_context (decl)
3201 tree context = DECL_CONTEXT (decl);
3205 if (TREE_CODE (context) == RECORD_TYPE
3206 || TREE_CODE (context) == UNION_TYPE)
3208 if (TREE_CODE (context) == TYPE_DECL
3209 || TREE_CODE (context) == FUNCTION_DECL)
3210 context = DECL_CONTEXT (context);
3211 else if (TREE_CODE (context) == BLOCK)
3212 context = BLOCK_SUPERCONTEXT (context);
3214 /* Unhandled CONTEXT!? */
3221 print_obstack_statistics (str, o)
3225 struct _obstack_chunk *chunk = o->chunk;
3232 n_alloc += chunk->limit - &chunk->contents[0];
3233 chunk = chunk->prev;
3235 fprintf (stderr, "obstack %s: %d bytes, %d chunks\n",
3236 str, n_alloc, n_chunks);
3239 dump_tree_statistics ()
3242 int total_nodes, total_bytes;
3244 fprintf (stderr, "\n??? tree nodes created\n\n");
3245 #ifdef GATHER_STATISTICS
3246 fprintf (stderr, "Kind Nodes Bytes\n");
3247 fprintf (stderr, "-------------------------------------\n");
3248 total_nodes = total_bytes = 0;
3249 for (i = 0; i < (int) all_kinds; i++)
3251 fprintf (stderr, "%-20s %6d %9d\n", tree_node_kind_names[i],
3252 tree_node_counts[i], tree_node_sizes[i]);
3253 total_nodes += tree_node_counts[i];
3254 total_bytes += tree_node_sizes[i];
3256 fprintf (stderr, "%-20s %9d\n", "identifier names", id_string_size);
3257 fprintf (stderr, "-------------------------------------\n");
3258 fprintf (stderr, "%-20s %6d %9d\n", "Total", total_nodes, total_bytes);
3259 fprintf (stderr, "-------------------------------------\n");
3261 fprintf (stderr, "(No per-node statistics)\n");
3263 print_lang_statistics ();