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1.1 root 1: /* Language-indepednent node constructors for parse phase of GNU compiler.
1.1.1.2 root 2: Copyright (C) 1987, 1988 Free Software Foundation, Inc.
1.1 root 3:
4: This file is part of GNU CC.
5:
1.1.1.13 root 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 1, or (at your option)
9: any later version.
10:
1.1 root 11: GNU CC is distributed in the hope that it will be useful,
1.1.1.13 root 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.
15:
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. */
1.1 root 19:
20:
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
26: nodes of that code.
27:
28: It is intended to be language-independent, but occasionally
29: calls language-dependent routines defined (for C) in typecheck.c.
30:
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. */
34:
35: #include "config.h"
36: #include <stdio.h>
37: #include "tree.h"
38: #include "obstack.h"
1.1.1.15 root 39: #include "gvarargs.h"
1.1.1.14 root 40: #include "flags.h"
1.1 root 41:
42: #define obstack_chunk_alloc xmalloc
43: #define obstack_chunk_free free
44:
45: extern int xmalloc ();
46: extern void free ();
47:
48: /* Tree nodes of permanent duration are allocated in this obstack.
49: They are the identifier nodes, and everything outside of
50: the bodies and parameters of function definitions. */
51:
52: struct obstack permanent_obstack;
53:
1.1.1.2 root 54: /* The initial RTL, and all ..._TYPE nodes, in a function
55: are allocated in this obstack. Usually they are freed at the
56: end of the function, but if the function is inline they are saved. */
57:
58: struct obstack maybepermanent_obstack;
59:
1.1 root 60: /* The contents of the current function definition are allocated
61: in this obstack, and all are freed at the end of the function. */
62:
63: struct obstack temporary_obstack;
64:
1.1.1.2 root 65: /* The tree nodes of an expression are allocated
66: in this obstack, and all are freed at the end of the expression. */
67:
68: struct obstack momentary_obstack;
69:
70: /* This points at either permanent_obstack or maybepermanent_obstack. */
71:
72: struct obstack *saveable_obstack;
73:
74: /* This is same as saveable_obstack during parse and expansion phase;
75: it points to temporary_obstack during optimization.
76: This is the obstack to be used for creating rtl objects. */
77:
78: struct obstack *rtl_obstack;
79:
1.1 root 80: /* This points at either permanent_obstack or temporary_obstack. */
81:
82: struct obstack *current_obstack;
83:
1.1.1.2 root 84: /* This points at either permanent_obstack or temporary_obstack
85: or momentary_obstack. */
86:
87: struct obstack *expression_obstack;
88:
89: /* Addresses of first objects in some obstacks.
90: This is for freeing their entire contents. */
91: char *maybepermanent_firstobj;
92: char *temporary_firstobj;
93: char *momentary_firstobj;
94:
1.1.1.5 root 95: /* Nonzero means all ..._TYPE nodes should be allocated permanently. */
96:
97: int all_types_permanent;
98:
1.1.1.2 root 99: /* Stack of places to restore the momentary obstack back to. */
100:
101: struct momentary_level
102: {
103: /* Pointer back to previous such level. */
104: struct momentary_level *prev;
105: /* First object allocated within this level. */
106: char *base;
107: /* Value of expression_obstack saved at entry to this level. */
108: struct obstack *obstack;
109: };
110:
111: struct momentary_level *momentary_stack;
112:
1.1 root 113: /* Table indexed by tree code giving a string containing a character
114: classifying the tree code. Possibilities are
115: t, d, s, c, r and e. See tree.def for details. */
116:
117: #define DEFTREECODE(SYM, NAME, TYPE, LENGTH) TYPE,
118:
119: char *tree_code_type[] = {
120: #include "tree.def"
121: };
122: #undef DEFTREECODE
123:
124: /* Table indexed by tree code giving number of expression
125: operands beyond the fixed part of the node structure.
126: Not used for types or decls. */
127:
128: #define DEFTREECODE(SYM, NAME, TYPE, LENGTH) LENGTH,
129:
130: int tree_code_length[] = {
131: #include "tree.def"
132: };
133: #undef DEFTREECODE
134:
135: /* Counter for assigning unique ids to all tree nodes. */
136:
137: int tree_node_counter = 0;
138:
139: /* Hash table for uniquizing IDENTIFIER_NODEs by name. */
140:
1.1.1.2 root 141: #define MAX_HASH_TABLE 1009
1.1 root 142: static tree hash_table[MAX_HASH_TABLE]; /* id hash buckets */
1.1.1.15 root 143:
144: /* 0 while creating built-in identifiers. */
145: static int do_identifier_warnings;
1.1 root 146:
147: /* Init data for node creation, at the beginning of compilation. */
148:
149: void
150: init_tree ()
151: {
152: obstack_init (&permanent_obstack);
1.1.1.2 root 153:
154: obstack_init (&temporary_obstack);
155: temporary_firstobj = (char *) obstack_alloc (&temporary_obstack, 0);
156: obstack_init (&momentary_obstack);
157: momentary_firstobj = (char *) obstack_alloc (&momentary_obstack, 0);
158: obstack_init (&maybepermanent_obstack);
159: maybepermanent_firstobj
160: = (char *) obstack_alloc (&maybepermanent_obstack, 0);
161:
1.1 root 162: current_obstack = &permanent_obstack;
1.1.1.2 root 163: expression_obstack = &permanent_obstack;
164: rtl_obstack = saveable_obstack = &permanent_obstack;
1.1 root 165: tree_node_counter = 1;
166: bzero (hash_table, sizeof hash_table);
167: }
168:
169: /* Start allocating on the temporary (per function) obstack.
1.1.1.2 root 170: This is done in start_function before parsing the function body,
171: and before each initialization at top level, and to go back
172: to temporary allocation after doing end_temporary_allocation. */
1.1 root 173:
1.1.1.2 root 174: void
1.1 root 175: temporary_allocation ()
176: {
177: current_obstack = &temporary_obstack;
1.1.1.2 root 178: expression_obstack = &temporary_obstack;
179: rtl_obstack = saveable_obstack = &maybepermanent_obstack;
180: momentary_stack = 0;
181: }
182:
183: /* Start allocating on the permanent obstack but don't
184: free the temporary data. After calling this, call
185: `permanent_allocation' to fully resume permanent allocation status. */
186:
187: void
188: end_temporary_allocation ()
189: {
190: current_obstack = &permanent_obstack;
191: expression_obstack = &permanent_obstack;
192: rtl_obstack = saveable_obstack = &permanent_obstack;
1.1 root 193: }
194:
1.1.1.4 root 195: /* Resume allocating on the temporary obstack, undoing
196: effects of `end_temporary_allocation'. */
197:
198: void
199: resume_temporary_allocation ()
200: {
201: current_obstack = &temporary_obstack;
202: expression_obstack = &temporary_obstack;
203: rtl_obstack = saveable_obstack = &maybepermanent_obstack;
204: }
205:
1.1.1.5 root 206: /* Nonzero if temporary allocation is currently in effect.
207: Zero if currently doing permanent allocation. */
208:
209: int
210: allocation_temporary_p ()
211: {
212: return current_obstack == &temporary_obstack;
213: }
214:
1.1 root 215: /* Go back to allocating on the permanent obstack
216: and free everything in the temporary obstack.
217: This is done in finish_function after fully compiling a function. */
218:
1.1.1.2 root 219: void
1.1 root 220: permanent_allocation ()
221: {
222: /* Free up previous temporary obstack data */
1.1.1.2 root 223: obstack_free (&temporary_obstack, temporary_firstobj);
224: obstack_free (&momentary_obstack, momentary_firstobj);
225: obstack_free (&maybepermanent_obstack, maybepermanent_firstobj);
1.1 root 226:
227: current_obstack = &permanent_obstack;
1.1.1.2 root 228: expression_obstack = &permanent_obstack;
229: rtl_obstack = saveable_obstack = &permanent_obstack;
1.1 root 230: }
231:
1.1.1.2 root 232: /* Save permanently everything on the maybepermanent_obstack. */
233:
234: void
235: preserve_data ()
236: {
237: maybepermanent_firstobj
238: = (char *) obstack_alloc (&maybepermanent_obstack, 0);
239: }
240:
1.1 root 241: /* Allocate SIZE bytes in the current obstack
242: and return a pointer to them.
243: In practice the current obstack is always the temporary one. */
244:
245: char *
246: oballoc (size)
247: int size;
248: {
249: return (char *) obstack_alloc (current_obstack, size);
250: }
251:
252: /* Free the object PTR in the current obstack
253: as well as everything allocated since PTR.
254: In practice the current obstack is always the temporary one. */
255:
256: void
257: obfree (ptr)
258: char *ptr;
259: {
260: obstack_free (current_obstack, ptr);
261: }
262:
263: /* Allocate SIZE bytes in the permanent obstack
264: and return a pointer to them. */
265:
266: char *
267: permalloc (size)
268: long size;
269: {
270: return (char *) obstack_alloc (&permanent_obstack, size);
271: }
1.1.1.15 root 272:
273: /* Allocate SIZE bytes in the saveable obstack
274: and return a pointer to them. */
275:
276: char *
277: savealloc (size)
278: int size;
279: {
280: return (char *) obstack_alloc (saveable_obstack, size);
281: }
1.1 root 282:
1.1.1.2 root 283: /* Start a level of momentary allocation.
284: In C, each compound statement has its own level
285: and that level is freed at the end of each statement.
286: All expression nodes are allocated in the momentary allocation level. */
287:
288: void
289: push_momentary ()
290: {
291: struct momentary_level *tem
292: = (struct momentary_level *) obstack_alloc (&momentary_obstack,
293: sizeof (struct momentary_level));
294: tem->prev = momentary_stack;
295: tem->base = (char *) obstack_base (&momentary_obstack);
296: tem->obstack = expression_obstack;
297: momentary_stack = tem;
298: expression_obstack = &momentary_obstack;
299: }
300:
301: /* Free all the storage in the current momentary-allocation level.
302: In C, this happens at the end of each statement. */
303:
304: void
305: clear_momentary ()
306: {
307: obstack_free (&momentary_obstack, momentary_stack->base);
308: }
309:
310: /* Discard a level of momentary allocation.
311: In C, this happens at the end of each compound statement.
312: Restore the status of expression node allocation
313: that was in effect before this level was created. */
314:
315: void
316: pop_momentary ()
317: {
318: struct momentary_level *tem = momentary_stack;
319: momentary_stack = tem->prev;
320: obstack_free (&momentary_obstack, tem);
321: expression_obstack = tem->obstack;
322: }
323:
324: /* Call when starting to parse a declaration:
325: make expressions in the declaration last the length of the function.
326: Returns an argument that should be passed to resume_momentary later. */
327:
328: int
329: suspend_momentary ()
330: {
331: register int tem = expression_obstack == &momentary_obstack;
1.1.1.4 root 332: expression_obstack = saveable_obstack;
1.1.1.2 root 333: return tem;
334: }
335:
336: /* Call when finished parsing a declaration:
337: restore the treatment of node-allocation that was
338: in effect before the suspension.
339: YES should be the value previously returned by suspend_momentary. */
340:
341: void
342: resume_momentary (yes)
343: int yes;
344: {
345: if (yes)
346: expression_obstack = &momentary_obstack;
347: }
348:
1.1 root 349: /* Return a newly allocated node of code CODE.
350: Initialize the node's unique id and its TREE_PERMANENT flag.
351: For decl and type nodes, some other fields are initialized.
352: The rest of the node is initialized to zero.
353:
354: Achoo! I got a code in the node. */
355:
356: tree
357: make_node (code)
358: enum tree_code code;
359: {
360: register tree t;
361: register int type = *tree_code_type[(int) code];
362: register int length;
1.1.1.2 root 363: register struct obstack *obstack = current_obstack;
1.1 root 364: register int i;
365:
366: switch (type)
367: {
368: case 'd': /* A decl node */
369: length = sizeof (struct tree_decl);
1.1.1.2 root 370: /* All decls in an inline function need to be saved. */
371: if (obstack != &permanent_obstack)
372: obstack = saveable_obstack;
1.1.1.16 root 373: /* PARM_DECLs always go on saveable_obstack, not permanent,
374: even though we may make them before the function turns
375: on temporary allocation. */
376: else if (code == PARM_DECL)
377: obstack = &maybepermanent_obstack;
1.1 root 378: break;
379:
380: case 't': /* a type node */
381: length = sizeof (struct tree_type);
1.1.1.2 root 382: /* All data types are put where we can preserve them if nec. */
383: if (obstack != &permanent_obstack)
1.1.1.5 root 384: obstack = all_types_permanent ? &permanent_obstack : saveable_obstack;
1.1 root 385: break;
386:
387: case 's': /* a stmt node */
1.1.1.2 root 388: length = sizeof (struct tree_common)
1.1 root 389: + 2 * sizeof (int)
390: + tree_code_length[(int) code] * sizeof (char *);
1.1.1.2 root 391: /* All stmts are put where we can preserve them if nec. */
392: if (obstack != &permanent_obstack)
393: obstack = saveable_obstack;
1.1 root 394: break;
395:
1.1.1.2 root 396: case 'r': /* a reference */
397: case 'e': /* an expression */
398: obstack = expression_obstack;
399: length = sizeof (struct tree_exp)
400: + (tree_code_length[(int) code] - 1) * sizeof (char *);
401: break;
402:
403: case 'c': /* a constant */
404: obstack = expression_obstack;
405: /* We can't use tree_code_length for this, since the number of words
406: is machine-dependent due to varying alignment of `double'. */
407: if (code == REAL_CST)
408: {
409: length = sizeof (struct tree_real_cst);
410: break;
411: }
412:
413: case 'x': /* something random, like an identifier. */
414: length = sizeof (struct tree_common)
1.1 root 415: + tree_code_length[(int) code] * sizeof (char *);
1.1.1.2 root 416: /* Identifier nodes are always permanent since they are
417: unique in a compiler run. */
418: if (code == IDENTIFIER_NODE) obstack = &permanent_obstack;
1.1 root 419: }
420:
421: t = (tree) obstack_alloc (obstack, length);
422:
423: TREE_UID (t) = tree_node_counter++;
424: TREE_TYPE (t) = 0;
425: TREE_CHAIN (t) = 0;
426: for (i = (length / sizeof (int)) - 1;
1.1.1.2 root 427: i >= sizeof (struct tree_common) / sizeof (int) - 1;
1.1 root 428: i--)
429: ((int *) t)[i] = 0;
430:
431: TREE_SET_CODE (t, code);
432: if (obstack == &permanent_obstack)
433: TREE_PERMANENT (t) = 1;
434:
435: if (type == 'd')
436: {
437: extern int lineno;
438:
439: DECL_ALIGN (t) = 1;
440: DECL_SIZE_UNIT (t) = 1;
441: DECL_VOFFSET_UNIT (t) = 1;
442: DECL_SOURCE_LINE (t) = lineno;
443: DECL_SOURCE_FILE (t) = input_filename;
444: }
445:
446: if (type == 't')
447: {
448: TYPE_ALIGN (t) = 1;
449: TYPE_SIZE_UNIT (t) = 1;
450: TYPE_MAIN_VARIANT (t) = t;
451: }
452:
453: if (type == 'c')
454: {
455: TREE_LITERAL (t) = 1;
456: }
457:
458: return t;
459: }
460:
461: /* Return a new node with the same contents as NODE
462: except that its TREE_CHAIN is zero and it has a fresh uid. */
463:
464: tree
465: copy_node (node)
466: tree node;
467: {
468: register tree t;
469: register enum tree_code code = TREE_CODE (node);
470: register int length;
471: register int i;
472:
473: switch (*tree_code_type[(int) code])
474: {
475: case 'd': /* A decl node */
476: length = sizeof (struct tree_decl);
477: break;
478:
479: case 't': /* a type node */
480: length = sizeof (struct tree_type);
481: break;
482:
483: case 's':
1.1.1.2 root 484: length = sizeof (struct tree_common)
1.1 root 485: + 2 * sizeof (int)
486: + tree_code_length[(int) code] * sizeof (char *);
487: break;
488:
1.1.1.2 root 489: case 'r': /* a reference */
490: case 'e': /* a expression */
491: length = sizeof (struct tree_exp)
492: + (tree_code_length[(int) code] - 1) * sizeof (char *);
493: break;
494:
495: case 'c': /* a constant */
496: /* We can't use tree_code_length for this, since the number of words
497: is machine-dependent due to varying alignment of `double'. */
498: if (code == REAL_CST)
499: {
500: length = sizeof (struct tree_real_cst);
501: break;
502: }
503:
504: case 'x': /* something random, like an identifier. */
505: length = sizeof (struct tree_common)
1.1 root 506: + tree_code_length[(int) code] * sizeof (char *);
507: }
508:
509: t = (tree) obstack_alloc (current_obstack, length);
510:
1.1.1.5 root 511: for (i = ((length + sizeof (int) - 1) / sizeof (int)) - 1;
1.1 root 512: i >= 0;
513: i--)
514: ((int *) t)[i] = ((int *) node)[i];
515:
516: TREE_UID (t) = tree_node_counter++;
517: TREE_CHAIN (t) = 0;
518:
519: TREE_PERMANENT (t) = (current_obstack == &permanent_obstack);
520:
521: return t;
522: }
1.1.1.15 root 523:
524: /* Return a copy of a chain of nodes, chained through the TREE_CHAIN field.
525: For example, this can copy a list made of TREE_LIST nodes. */
526:
527: tree
528: copy_list (list)
529: tree list;
530: {
531: tree head;
532: register tree prev, next;
533:
534: if (list == 0)
535: return 0;
536:
537: head = prev = copy_node (list);
538: next = TREE_CHAIN (list);
539: while (next)
540: {
541: TREE_CHAIN (prev) = copy_node (next);
542: prev = TREE_CHAIN (prev);
543: next = TREE_CHAIN (next);
544: }
545: return head;
546: }
1.1 root 547:
548: #define HASHBITS 30
549:
550: /* Return an IDENTIFIER_NODE whose name is TEXT (a null-terminated string).
551: If an identifier with that name has previously been referred to,
552: the same node is returned this time. */
553:
554: tree
555: get_identifier (text)
556: register char *text;
557: {
558: register int hi;
559: register int i;
560: register tree idp;
1.1.1.14 root 561: register int len, hash_len;
1.1 root 562:
563: /* Compute length of text in len. */
564: for (len = 0; text[len]; len++);
565:
1.1.1.14 root 566: /* Decide how much of that length to hash on */
567: hash_len = len;
568: if (warn_id_clash && len > id_clash_len)
569: hash_len = id_clash_len;
570:
1.1 root 571: /* Compute hash code */
1.1.1.14 root 572: hi = hash_len;
573: for (i = 0; i < hash_len; i++)
1.1 root 574: hi = ((hi * 613) + (unsigned)(text[i]));
575:
576: hi &= (1 << HASHBITS) - 1;
577: hi %= MAX_HASH_TABLE;
578:
579: /* Search table for identifier */
1.1.1.14 root 580: for (idp = hash_table[hi]; idp; idp = TREE_CHAIN (idp))
581: if (IDENTIFIER_LENGTH (idp) == len
582: && !strcmp (IDENTIFIER_POINTER (idp), text))
1.1 root 583: return idp; /* <-- return if found */
1.1.1.14 root 584:
585: /* Not found; optionally warn about a similar identifier */
1.1.1.17! root 586: if (warn_id_clash && do_identifier_warnings && len >= id_clash_len)
1.1.1.14 root 587: for (idp = hash_table[hi]; idp; idp = TREE_CHAIN (idp))
588: if (!strncmp (IDENTIFIER_POINTER (idp), text, id_clash_len))
589: {
590: warning ("`%s' and `%s' identical in first n characters",
591: IDENTIFIER_POINTER (idp), text);
592: break;
593: }
1.1 root 594:
595: /* Not found, create one, add to chain */
596: idp = make_node (IDENTIFIER_NODE);
597: IDENTIFIER_LENGTH (idp) = len;
598:
599: IDENTIFIER_POINTER (idp) = obstack_copy0 (&permanent_obstack, text, len);
600:
601: TREE_CHAIN (idp) = hash_table[hi];
602: hash_table[hi] = idp;
603: return idp; /* <-- return if created */
604: }
1.1.1.15 root 605:
606: /* Enable warnings on similar identifiers (if requested).
607: Done after the built-in identifiers are created. */
608:
609: void
610: start_identifier_warnings ()
611: {
612: do_identifier_warnings = 1;
613: }
614:
615: /* Record the size of an identifier node for the language in use.
616: This is called by the language-specific files. */
617:
618: void
619: set_identifier_size (size)
620: int size;
621: {
622: tree_code_length[(int) IDENTIFIER_NODE] = size;
623: }
1.1 root 624:
625: /* Return a newly constructed INTEGER_CST node whose constant value
626: is specified by the two ints LOW and HI.
1.1.1.2 root 627: The TREE_TYPE is set to `int'. */
1.1 root 628:
629: tree
630: build_int_2 (low, hi)
631: int low, hi;
632: {
633: register tree t = make_node (INTEGER_CST);
634: TREE_INT_CST_LOW (t) = low;
635: TREE_INT_CST_HIGH (t) = hi;
636: TREE_TYPE (t) = integer_type_node;
637: return t;
638: }
639:
1.1.1.4 root 640: /* Return a new REAL_CST node whose type is TYPE and value is D. */
1.1 root 641:
642: tree
1.1.1.4 root 643: build_real (type, d)
644: tree type;
1.1.1.12 root 645: REAL_VALUE_TYPE d;
1.1 root 646: {
647: tree v;
648:
1.1.1.4 root 649: /* Check for valid float value for this type on this target machine;
650: if not, can print error message and store a valid value in D. */
651: #ifdef CHECK_FLOAT_VALUE
652: CHECK_FLOAT_VALUE (TYPE_MODE (type), d);
653: #endif
654:
1.1 root 655: v = make_node (REAL_CST);
1.1.1.4 root 656: TREE_TYPE (v) = type;
1.1 root 657: TREE_REAL_CST (v) = d;
658: return v;
659: }
660:
1.1.1.4 root 661: /* Return a new REAL_CST node whose type is TYPE
662: and whose value is the integer value of the INTEGER_CST node I. */
1.1 root 663:
1.1.1.12 root 664: #if !defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
665:
1.1.1.15 root 666: REAL_VALUE_TYPE
667: real_value_from_int_cst (i)
1.1 root 668: tree i;
669: {
1.1.1.15 root 670: REAL_VALUE_TYPE d;
1.1.1.12 root 671: #ifdef REAL_ARITHMETIC
672: REAL_VALUE_FROM_INT (d, TREE_INT_CST_LOW (i), TREE_INT_CST_HIGH (i));
673: #else /* not REAL_ARITHMETIC */
1.1.1.2 root 674: if (TREE_INT_CST_HIGH (i) < 0)
675: {
676: d = (double) (~ TREE_INT_CST_HIGH (i));
677: d *= ((double) (1 << (HOST_BITS_PER_INT / 2))
678: * (double) (1 << (HOST_BITS_PER_INT / 2)));
679: d += (double) (unsigned) (~ TREE_INT_CST_LOW (i));
680: d = (- d - 1.0);
681: }
682: else
683: {
684: d = (double) TREE_INT_CST_HIGH (i);
685: d *= ((double) (1 << (HOST_BITS_PER_INT / 2))
686: * (double) (1 << (HOST_BITS_PER_INT / 2)));
687: d += (double) (unsigned) TREE_INT_CST_LOW (i);
688: }
1.1.1.12 root 689: #endif /* not REAL_ARITHMETIC */
1.1.1.15 root 690: return d;
691: }
692:
693: /* This function can't be implemented if we can't do arithmetic
694: on the float representation. */
695:
696: tree
697: build_real_from_int_cst (type, i)
698: tree type;
699: tree i;
700: {
701: tree v;
702: REAL_VALUE_TYPE d;
1.1.1.2 root 703:
1.1.1.15 root 704: v = make_node (REAL_CST);
705: TREE_TYPE (v) = type;
706:
707: d = real_value_from_int_cst (i);
1.1.1.6 root 708: /* Check for valid float value for this type on this target machine;
709: if not, can print error message and store a valid value in D. */
710: #ifdef CHECK_FLOAT_VALUE
711: CHECK_FLOAT_VALUE (TYPE_MODE (type), d);
712: #endif
713:
1.1.1.2 root 714: TREE_REAL_CST (v) = d;
1.1 root 715: return v;
716: }
717:
1.1.1.12 root 718: #endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */
719:
1.1 root 720: /* Return a newly constructed STRING_CST node whose value is
721: the LEN characters at STR.
722: The TREE_TYPE is not initialized. */
723:
724: tree
725: build_string (len, str)
726: int len;
727: char *str;
728: {
729: register tree s = make_node (STRING_CST);
730: TREE_STRING_LENGTH (s) = len;
1.1.1.2 root 731: TREE_STRING_POINTER (s) = obstack_copy0 (saveable_obstack, str, len);
1.1 root 732: return s;
733: }
734:
735: /* Return a newly constructed COMPLEX_CST node whose value is
736: specified by the real and imaginary parts REAL and IMAG.
737: Both REAL and IMAG should be constant nodes.
738: The TREE_TYPE is not initialized. */
739:
740: tree
741: build_complex (real, imag)
742: tree real, imag;
743: {
744: register tree t = make_node (COMPLEX_CST);
745: TREE_REALPART (t) = real;
746: TREE_IMAGPART (t) = imag;
747: return t;
748: }
749:
750: /* Return 1 if EXPR is the integer constant zero. */
751:
752: int
753: integer_zerop (expr)
754: tree expr;
755: {
1.1.1.2 root 756: return (TREE_CODE (expr) == INTEGER_CST
757: && TREE_INT_CST_LOW (expr) == 0
758: && TREE_INT_CST_HIGH (expr) == 0);
1.1 root 759: }
760:
761: /* Return 1 if EXPR is the integer constant one. */
762:
763: int
764: integer_onep (expr)
765: tree expr;
766: {
1.1.1.2 root 767: return (TREE_CODE (expr) == INTEGER_CST
768: && TREE_INT_CST_LOW (expr) == 1
769: && TREE_INT_CST_HIGH (expr) == 0);
1.1 root 770: }
771:
772: /* Return 1 if EXPR is an integer containing all 1's
773: in as much precision as it contains. */
774:
775: int
776: integer_all_onesp (expr)
777: tree expr;
778: {
779: register int prec;
780: register int uns;
781:
782: if (TREE_CODE (expr) != INTEGER_CST)
783: return 0;
784:
1.1.1.2 root 785: uns = TREE_UNSIGNED (TREE_TYPE (expr));
1.1 root 786: if (!uns)
787: return TREE_INT_CST_LOW (expr) == -1 && TREE_INT_CST_HIGH (expr) == -1;
788:
789: prec = TYPE_PRECISION (TREE_TYPE (expr));
790: if (prec >= HOST_BITS_PER_INT)
791: return TREE_INT_CST_LOW (expr) == -1
792: && TREE_INT_CST_HIGH (expr) == (1 << (prec - HOST_BITS_PER_INT)) - 1;
793: else
794: return TREE_INT_CST_LOW (expr) == (1 << prec) - 1;
795: }
796:
797: /* Return the length of a chain of nodes chained through TREE_CHAIN.
798: We expect a null pointer to mark the end of the chain.
799: This is the Lisp primitive `length'. */
800:
801: int
802: list_length (t)
803: tree t;
804: {
805: register tree tail;
806: register int len = 0;
807:
808: for (tail = t; tail; tail = TREE_CHAIN (tail))
809: len++;
810:
811: return len;
812: }
813:
814: /* Concatenate two chains of nodes (chained through TREE_CHAIN)
815: by modifying the last node in chain 1 to point to chain 2.
816: This is the Lisp primitive `nconc'. */
817:
818: tree
819: chainon (op1, op2)
820: tree op1, op2;
821: {
822: tree t;
823:
824: if (op1)
825: {
826: for (t = op1; TREE_CHAIN (t); t = TREE_CHAIN (t))
827: if (t == op2) abort (); /* Circularity being created */
828: TREE_CHAIN (t) = op2;
829: return op1;
830: }
831: else return op2;
832: }
833:
834: /* Return a newly created TREE_LIST node whose
835: purpose and value fields are PARM and VALUE. */
836:
837: tree
838: build_tree_list (parm, value)
839: tree parm, value;
840: {
841: register tree t = make_node (TREE_LIST);
842: TREE_PURPOSE (t) = parm;
843: TREE_VALUE (t) = value;
844: return t;
845: }
846:
847: /* Return a newly created TREE_LIST node whose
848: purpose and value fields are PARM and VALUE
849: and whose TREE_CHAIN is CHAIN. */
850:
851: tree
852: tree_cons (purpose, value, chain)
853: tree purpose, value, chain;
854: {
855: register tree node = make_node (TREE_LIST);
856: TREE_CHAIN (node) = chain;
857: TREE_PURPOSE (node) = purpose;
858: TREE_VALUE (node) = value;
859: return node;
860: }
861:
1.1.1.2 root 862: /* Same as `tree_cons' but make a permanent object. */
863:
864: tree
865: perm_tree_cons (purpose, value, chain)
866: tree purpose, value, chain;
867: {
868: register tree node;
869: register struct obstack *ambient_obstack = current_obstack;
870: current_obstack = &permanent_obstack;
871:
872: node = make_node (TREE_LIST);
873: TREE_CHAIN (node) = chain;
874: TREE_PURPOSE (node) = purpose;
875: TREE_VALUE (node) = value;
876:
877: current_obstack = ambient_obstack;
878: return node;
879: }
880:
1.1.1.7 root 881: /* Same as `tree_cons', but make this node temporary, regardless. */
882:
883: tree
884: temp_tree_cons (purpose, value, chain)
885: tree purpose, value, chain;
886: {
887: register tree node;
888: register struct obstack *ambient_obstack = current_obstack;
889: current_obstack = &temporary_obstack;
890:
891: node = make_node (TREE_LIST);
892: TREE_CHAIN (node) = chain;
893: TREE_PURPOSE (node) = purpose;
894: TREE_VALUE (node) = value;
895:
896: current_obstack = ambient_obstack;
897: return node;
898: }
899:
1.1.1.9 root 900: /* Same as `tree_cons', but save this node if the function's RTL is saved. */
901:
902: tree
903: saveable_tree_cons (purpose, value, chain)
904: tree purpose, value, chain;
905: {
906: register tree node;
907: register struct obstack *ambient_obstack = current_obstack;
908: current_obstack = saveable_obstack;
909:
910: node = make_node (TREE_LIST);
911: TREE_CHAIN (node) = chain;
912: TREE_PURPOSE (node) = purpose;
913: TREE_VALUE (node) = value;
914:
915: current_obstack = ambient_obstack;
916: return node;
917: }
918:
1.1 root 919: /* Return the last node in a chain of nodes (chained through TREE_CHAIN). */
920:
921: tree
922: tree_last (chain)
923: register tree chain;
924: {
925: register tree next;
926: if (chain)
927: while (next = TREE_CHAIN (chain))
928: chain = next;
929: return chain;
930: }
931:
932: /* Reverse the order of elements in the chain T,
933: and return the new head of the chain (old last element). */
934:
935: tree
936: nreverse (t)
937: tree t;
938: {
939: register tree prev = 0, decl, next;
940: for (decl = t; decl; decl = next)
941: {
942: next = TREE_CHAIN (decl);
943: TREE_CHAIN (decl) = prev;
944: prev = decl;
945: }
946: return prev;
947: }
948:
949: /* Return the size nominally occupied by an object of type TYPE
950: when it resides in memory. The value is measured in units of bytes,
951: and its data type is that normally used for type sizes
952: (which is the first type created by make_signed_type or
953: make_unsigned_type). */
954:
955: tree
956: size_in_bytes (type)
957: tree type;
958: {
959: if (type == error_mark_node)
960: return integer_zero_node;
1.1.1.13 root 961: type = TYPE_MAIN_VARIANT (type);
1.1.1.2 root 962: if (TYPE_SIZE (type) == 0)
963: {
964: incomplete_type_error (0, type);
965: return integer_zero_node;
966: }
1.1 root 967: return convert_units (TYPE_SIZE (type), TYPE_SIZE_UNIT (type),
968: BITS_PER_UNIT);
969: }
970:
1.1.1.2 root 971: /* Return the size of TYPE (in bytes) as an integer,
972: or return -1 if the size can vary. */
973:
974: int
975: int_size_in_bytes (type)
976: tree type;
977: {
978: int size;
979: if (type == error_mark_node)
980: return 0;
1.1.1.13 root 981: type = TYPE_MAIN_VARIANT (type);
1.1.1.2 root 982: if (TYPE_SIZE (type) == 0)
983: return -1;
984: if (TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST)
985: return -1;
986: size = TREE_INT_CST_LOW (TYPE_SIZE (type)) * TYPE_SIZE_UNIT (type);
987: return (size + BITS_PER_UNIT - 1) / BITS_PER_UNIT;
988: }
989:
1.1.1.7 root 990: /* Return, as an INTEGER_CST node, the number of elements for
991: TYPE (which is an ARRAY_TYPE). */
992:
993: tree
994: array_type_nelts (type)
995: tree type;
996: {
997: tree index_type = TYPE_DOMAIN (type);
998: return (tree_int_cst_equal (TYPE_MIN_VALUE (index_type), integer_zero_node)
999: ? TYPE_MAX_VALUE (index_type)
1000: : fold (build (MINUS_EXPR, integer_type_node,
1001: TYPE_MAX_VALUE (index_type),
1002: TYPE_MIN_VALUE (index_type))));
1003: }
1004:
1.1 root 1005: /* Return nonzero if arg is static -- a reference to an object in
1006: static storage. This is not the same as the C meaning of `static'. */
1007:
1008: int
1009: staticp (arg)
1010: tree arg;
1011: {
1012: register enum tree_code code = TREE_CODE (arg);
1013:
1.1.1.2 root 1014: if ((code == VAR_DECL || code == FUNCTION_DECL || code == CONSTRUCTOR)
1.1 root 1015: && (TREE_STATIC (arg) || TREE_EXTERNAL (arg)))
1016: return 1;
1017:
1.1.1.2 root 1018: if (code == STRING_CST)
1019: return 1;
1020:
1.1 root 1021: if (code == COMPONENT_REF)
1.1.1.10 root 1022: return (DECL_VOFFSET (TREE_OPERAND (arg, 1)) == 0
1023: && staticp (TREE_OPERAND (arg, 0)));
1024:
1025: if (code == INDIRECT_REF)
1026: return TREE_LITERAL (TREE_OPERAND (arg, 0));
1.1 root 1027:
1.1.1.2 root 1028: if (code == ARRAY_REF)
1029: {
1030: if (TREE_CODE (TYPE_SIZE (TREE_TYPE (arg))) == INTEGER_CST
1031: && TREE_CODE (TREE_OPERAND (arg, 1)) == INTEGER_CST)
1032: return staticp (TREE_OPERAND (arg, 0));
1033: }
1034:
1.1 root 1035: return 0;
1036: }
1037:
1.1.1.2 root 1038: /* Return nonzero if REF is an lvalue valid for this language.
1039: Lvalues can be assigned, unless they have TREE_READONLY.
1040: Lvalues can have their address taken, unless they have TREE_REGDECL. */
1.1 root 1041:
1042: int
1.1.1.2 root 1043: lvalue_p (ref)
1.1 root 1044: tree ref;
1045: {
1046: register enum tree_code code = TREE_CODE (ref);
1047:
1.1.1.2 root 1048: if (language_lvalue_valid (ref))
1049: switch (code)
1050: {
1051: case COMPONENT_REF:
1052: return lvalue_p (TREE_OPERAND (ref, 0));
1053:
1054: case STRING_CST:
1055: return 1;
1056:
1057: case INDIRECT_REF:
1058: case ARRAY_REF:
1059: case VAR_DECL:
1060: case PARM_DECL:
1061: case RESULT_DECL:
1062: case ERROR_MARK:
1.1.1.15 root 1063: if (TREE_CODE (TREE_TYPE (ref)) != FUNCTION_TYPE
1064: && TREE_CODE (TREE_TYPE (ref)) != METHOD_TYPE)
1.1.1.2 root 1065: return 1;
1.1.1.7 root 1066: break;
1067:
1.1.1.15 root 1068: case NEW_EXPR:
1069: return 1;
1070:
1.1.1.7 root 1071: case CALL_EXPR:
1072: if (TREE_CODE (TREE_TYPE (ref)) == REFERENCE_TYPE)
1073: return 1;
1.1.1.2 root 1074: }
1.1 root 1075: return 0;
1076: }
1.1.1.2 root 1077:
1078: /* Return nonzero if REF is an lvalue valid for this language;
1079: otherwise, print an error message and return zero. */
1080:
1081: int
1082: lvalue_or_else (ref, string)
1083: tree ref;
1084: char *string;
1085: {
1086: int win = lvalue_p (ref);
1087: if (! win)
1088: error ("invalid lvalue in %s", string);
1089: return win;
1090: }
1.1 root 1091:
1092: /* This should be applied to any node which may be used in more than one place,
1093: but must be evaluated only once. Normally, the code generator would
1094: reevaluate the node each time; this forces it to compute it once and save
1095: the result. This is done by encapsulating the node in a SAVE_EXPR. */
1096:
1097: tree
1098: save_expr (expr)
1099: tree expr;
1100: {
1101: register tree t = fold (expr);
1102:
1.1.1.2 root 1103: /* If the tree evaluates to a constant, then we don't want to hide that
1.1 root 1104: fact (i.e. this allows further folding, and direct checks for constants).
1105: Since it is no problem to reevaluate literals, we just return the
1106: literal node. */
1107:
1108: if (TREE_LITERAL (t) || TREE_READONLY (t) || TREE_CODE (t) == SAVE_EXPR)
1109: return t;
1110:
1.1.1.2 root 1111: return build (SAVE_EXPR, TREE_TYPE (expr), t, NULL);
1.1 root 1112: }
1113:
1114: /* Stabilize a reference so that we can use it any number of times
1115: without causing its operands to be evaluated more than once.
1.1.1.2 root 1116: Returns the stabilized reference.
1117:
1118: Also allows conversion expressions whose operands are references.
1119: Any other kind of expression is returned unchanged. */
1.1 root 1120:
1121: tree
1122: stabilize_reference (ref)
1123: tree ref;
1124: {
1125: register tree result;
1126: register enum tree_code code = TREE_CODE (ref);
1127:
1.1.1.2 root 1128: switch (code)
1.1 root 1129: {
1.1.1.2 root 1130: case VAR_DECL:
1131: case PARM_DECL:
1132: case RESULT_DECL:
1.1 root 1133: result = ref;
1.1.1.2 root 1134: break;
1135:
1136: case NOP_EXPR:
1137: case CONVERT_EXPR:
1138: case FLOAT_EXPR:
1139: case FIX_TRUNC_EXPR:
1140: case FIX_FLOOR_EXPR:
1141: case FIX_ROUND_EXPR:
1142: case FIX_CEIL_EXPR:
1143: result = build_nt (code, stabilize_reference (TREE_OPERAND (ref, 0)));
1144: break;
1145:
1146: case INDIRECT_REF:
1147: result = build_nt (INDIRECT_REF, save_expr (TREE_OPERAND (ref, 0)));
1148: break;
1149:
1150: case COMPONENT_REF:
1151: result = build_nt (COMPONENT_REF,
1152: stabilize_reference (TREE_OPERAND (ref, 0)),
1153: TREE_OPERAND (ref, 1));
1154: break;
1155:
1156: case ARRAY_REF:
1157: result = build_nt (ARRAY_REF, stabilize_reference (TREE_OPERAND (ref, 0)),
1158: save_expr (TREE_OPERAND (ref, 1)));
1159: break;
1160:
1161: /* If arg isn't a kind of lvalue we recognize, make no change.
1162: Caller should recognize the error for an invalid lvalue. */
1163: default:
1164: return ref;
1165:
1166: case ERROR_MARK:
1.1 root 1167: return error_mark_node;
1168: }
1169:
1170: TREE_TYPE (result) = TREE_TYPE (ref);
1.1.1.2 root 1171: TREE_READONLY (result) = TREE_READONLY (ref);
1.1 root 1172: TREE_VOLATILE (result) = TREE_VOLATILE (ref);
1.1.1.2 root 1173: TREE_THIS_VOLATILE (result) = TREE_THIS_VOLATILE (ref);
1.1 root 1174:
1175: return result;
1176: }
1177:
1178: /* Low-level constructors for expressions. */
1179:
1.1.1.2 root 1180: /* Build an expression of code CODE, data type TYPE,
1181: and operands as specified by the arguments ARG1 and following arguments.
1182: Expressions and reference nodes can be created this way.
1183: Constants, decls, types and misc nodes cannot be. */
1.1 root 1184:
1185: tree
1.1.1.2 root 1186: build (va_alist)
1187: va_dcl
1.1 root 1188: {
1.1.1.2 root 1189: register va_list p;
1190: enum tree_code code;
1191: register tree t;
1192: register int length;
1193: register int i;
1194:
1195: va_start (p);
1.1 root 1196:
1.1.1.2 root 1197: code = va_arg (p, enum tree_code);
1198: t = make_node (code);
1199: length = tree_code_length[(int) code];
1200: TREE_TYPE (t) = va_arg (p, tree);
1201:
1202: if (length == 2)
1203: {
1204: /* This is equivalent to the loop below, but faster. */
1205: register tree arg0 = va_arg (p, tree);
1206: register tree arg1 = va_arg (p, tree);
1207: TREE_OPERAND (t, 0) = arg0;
1208: TREE_OPERAND (t, 1) = arg1;
1209: TREE_VOLATILE (t)
1210: = (arg0 && TREE_VOLATILE (arg0)) || (arg1 && TREE_VOLATILE (arg1));
1211: }
1212: else
1213: {
1214: for (i = 0; i < length; i++)
1215: {
1216: register tree operand = va_arg (p, tree);
1217: TREE_OPERAND (t, i) = operand;
1218: if (operand && TREE_VOLATILE (operand))
1219: TREE_VOLATILE (t) = 1;
1220: }
1221: }
1222: va_end (p);
1.1 root 1223: return t;
1224: }
1225:
1.1.1.2 root 1226: /* Similar except don't specify the TREE_TYPE
1227: and leave the TREE_VOLATILE as 0.
1228: It is permissible for arguments to be null,
1229: or even garbage if their values do not matter. */
1.1 root 1230:
1231: tree
1.1.1.2 root 1232: build_nt (va_alist)
1233: va_dcl
1.1 root 1234: {
1.1.1.2 root 1235: register va_list p;
1236: register enum tree_code code;
1237: register tree t;
1238: register int length;
1239: register int i;
1240:
1241: va_start (p);
1.1 root 1242:
1.1.1.2 root 1243: code = va_arg (p, enum tree_code);
1244: t = make_node (code);
1245: length = tree_code_length[(int) code];
1246:
1247: for (i = 0; i < length; i++)
1248: TREE_OPERAND (t, i) = va_arg (p, tree);
1249:
1250: va_end (p);
1.1 root 1251: return t;
1252: }
1.1.1.11 root 1253:
1254: tree
1255: build_op_identifier (op1, op2)
1256: tree op1, op2;
1257: {
1258: register tree t = make_node (OP_IDENTIFIER);
1259: TREE_PURPOSE (t) = op1;
1260: TREE_VALUE (t) = op2;
1261: return t;
1262: }
1.1.1.2 root 1263:
1264: /* Create a DECL_... node of code CODE, name NAME and data type TYPE.
1265: We do NOT enter this node in any sort of symbol table.
1.1 root 1266:
1.1.1.2 root 1267: layout_decl is used to set up the decl's storage layout.
1268: Other slots are initialized to 0 or null pointers. */
1.1 root 1269:
1270: tree
1.1.1.2 root 1271: build_decl (code, name, type)
1272: enum tree_code code;
1273: tree name, type;
1274: {
1275: register tree t;
1276:
1277: t = make_node (code);
1278:
1279: /* if (type == error_mark_node)
1280: type = integer_type_node; */
1281: /* That is not done, deliberately, so that having error_mark_node
1282: as the type can suppress useless errors in the use of this variable. */
1283:
1284: DECL_NAME (t) = name;
1.1.1.15 root 1285: if (name)
1286: {
1287: DECL_PRINT_NAME (t) = IDENTIFIER_POINTER (name);
1288: DECL_ASSEMBLER_NAME (t) = IDENTIFIER_POINTER (name);
1289: }
1.1.1.2 root 1290: TREE_TYPE (t) = type;
1291: DECL_ARGUMENTS (t) = NULL_TREE;
1292: DECL_INITIAL (t) = NULL_TREE;
1293:
1294: if (code == VAR_DECL || code == PARM_DECL || code == RESULT_DECL)
1295: layout_decl (t, 0);
1296: else if (code == FUNCTION_DECL)
1297: DECL_MODE (t) = FUNCTION_MODE;
1298:
1.1 root 1299: return t;
1300: }
1301:
1.1.1.7 root 1302: #if 0
1.1 root 1303: /* Low-level constructors for statements.
1304: These constructors all expect source file name and line number
1305: as arguments, as well as enough arguments to fill in the data
1306: in the statement node. */
1307:
1308: tree
1309: build_goto (filename, line, label)
1310: char *filename;
1311: int line;
1312: tree label;
1313: {
1314: register tree t = make_node (GOTO_STMT);
1315: STMT_SOURCE_FILE (t) = filename;
1316: STMT_SOURCE_LINE (t) = line;
1317: STMT_BODY (t) = label;
1318: return t;
1319: }
1320:
1321: tree
1322: build_return (filename, line, arg)
1323: char *filename;
1324: int line;
1325: tree arg;
1326: {
1327: register tree t = make_node (RETURN_STMT);
1328:
1329: STMT_SOURCE_FILE (t) = filename;
1330: STMT_SOURCE_LINE (t) = line;
1331: STMT_BODY (t) = arg;
1332: return t;
1333: }
1334:
1335: tree
1336: build_expr_stmt (filename, line, expr)
1337: char *filename;
1338: int line;
1339: tree expr;
1340: {
1341: register tree t = make_node (EXPR_STMT);
1342:
1343: STMT_SOURCE_FILE (t) = filename;
1344: STMT_SOURCE_LINE (t) = line;
1345: STMT_BODY (t) = expr;
1346: return t;
1347: }
1348:
1349: tree
1350: build_if (filename, line, cond, thenclause, elseclause)
1351: char *filename;
1352: int line;
1353: tree cond, thenclause, elseclause;
1354: {
1355: register tree t = make_node (IF_STMT);
1356:
1357: STMT_SOURCE_FILE (t) = filename;
1358: STMT_SOURCE_LINE (t) = line;
1359: STMT_COND (t) = cond;
1360: STMT_THEN (t) = thenclause;
1361: STMT_ELSE (t) = elseclause;
1362: return t;
1363: }
1364:
1365: tree
1366: build_exit (filename, line, cond)
1367: char *filename;
1368: int line;
1369: tree cond;
1370: {
1371: register tree t = make_node (EXIT_STMT);
1372: STMT_SOURCE_FILE (t) = filename;
1373: STMT_SOURCE_LINE (t) = line;
1374: STMT_BODY (t) = cond;
1375: return t;
1376: }
1377:
1378: tree
1379: build_asm_stmt (filename, line, asmcode)
1380: char *filename;
1381: int line;
1382: tree asmcode;
1383: {
1384: register tree t = make_node (ASM_STMT);
1385: STMT_SOURCE_FILE (t) = filename;
1386: STMT_SOURCE_LINE (t) = line;
1387: STMT_BODY (t) = asmcode;
1388: return t;
1389: }
1390:
1391: tree
1392: build_case (filename, line, object, cases)
1393: char *filename;
1394: int line;
1395: tree object, cases;
1396: {
1397: register tree t = make_node (CASE_STMT);
1398: STMT_SOURCE_FILE (t) = filename;
1399: STMT_SOURCE_LINE (t) = line;
1400: STMT_CASE_INDEX (t) = object;
1401: STMT_CASE_LIST (t) = cases;
1402: return t;
1403: }
1404:
1405: tree
1.1.1.7 root 1406: build_loop (filename, line, body)
1.1 root 1407: char *filename;
1408: int line;
1.1.1.7 root 1409: tree body;
1.1 root 1410: {
1.1.1.7 root 1411: register tree t = make_node (LOOP_STMT);
1.1 root 1412: STMT_SOURCE_FILE (t) = filename;
1413: STMT_SOURCE_LINE (t) = line;
1414: STMT_BODY (t) = body;
1415: return t;
1416: }
1417:
1418: tree
1.1.1.7 root 1419: build_compound (filename, line, body)
1.1 root 1420: char *filename;
1421: int line;
1422: tree body;
1423: {
1.1.1.7 root 1424: register tree t = make_node (COMPOUND_STMT);
1.1 root 1425: STMT_SOURCE_FILE (t) = filename;
1426: STMT_SOURCE_LINE (t) = line;
1427: STMT_BODY (t) = body;
1428: return t;
1429: }
1430:
1.1.1.7 root 1431: #endif /* 0 */
1432:
1433: /* LET_STMT nodes are used to represent the structure of binding contours
1434: and declarations, once those contours have been exited and their contents
1435: compiled. This information is used for outputting debugging info. */
1436:
1.1 root 1437: tree
1.1.1.15 root 1438: build_let (filename, line, vars, subblocks, supercontext, tags)
1.1 root 1439: char *filename;
1440: int line;
1.1.1.15 root 1441: tree vars, subblocks, supercontext, tags;
1.1 root 1442: {
1.1.1.7 root 1443: register tree t = make_node (LET_STMT);
1.1 root 1444: STMT_SOURCE_FILE (t) = filename;
1445: STMT_SOURCE_LINE (t) = line;
1.1.1.7 root 1446: STMT_VARS (t) = vars;
1.1.1.15 root 1447: STMT_SUBBLOCKS (t) = subblocks;
1.1.1.7 root 1448: STMT_SUPERCONTEXT (t) = supercontext;
1449: STMT_BIND_SIZE (t) = 0;
1450: STMT_TYPE_TAGS (t) = tags;
1.1 root 1451: return t;
1452: }
1453:
1454: /* Return a type like TYPE except that its TREE_READONLY is CONSTP
1455: and its TREE_VOLATILE is VOLATILEP.
1456:
1457: Such variant types already made are recorded so that duplicates
1458: are not made.
1459:
1460: A variant types should never be used as the type of an expression.
1461: Always copy the variant information into the TREE_READONLY
1462: and TREE_VOLATILE of the expression, and then give the expression
1463: as its type the "main variant", the variant whose TREE_READONLY
1464: and TREE_VOLATILE are zero. Use TYPE_MAIN_VARIANT to find the
1465: main variant. */
1466:
1467: tree
1468: build_type_variant (type, constp, volatilep)
1469: tree type;
1470: int constp, volatilep;
1471: {
1472: register tree t, m = TYPE_MAIN_VARIANT (type);
1473: register struct obstack *ambient_obstack = current_obstack;
1474:
1475: /* Treat any nonzero argument as 1. */
1476: constp = !!constp;
1477: volatilep = !!volatilep;
1478:
1479: /* First search the chain variants for one that is what we want. */
1480:
1481: for (t = m; t; t = TYPE_NEXT_VARIANT (t))
1482: if (constp == TREE_READONLY (t)
1483: && volatilep == TREE_VOLATILE (t))
1484: return t;
1485:
1486: /* We need a new one. */
1.1.1.2 root 1487: current_obstack
1488: = TREE_PERMANENT (type) ? &permanent_obstack : saveable_obstack;
1.1 root 1489:
1490: t = copy_node (type);
1491: TREE_READONLY (t) = constp;
1492: TREE_VOLATILE (t) = volatilep;
1493: TYPE_POINTER_TO (t) = 0;
1.1.1.7 root 1494: TYPE_REFERENCE_TO (t) = 0;
1.1 root 1495:
1496: /* Add this type to the chain of variants of TYPE. */
1497: TYPE_NEXT_VARIANT (t) = TYPE_NEXT_VARIANT (m);
1498: TYPE_NEXT_VARIANT (m) = t;
1499:
1500: current_obstack = ambient_obstack;
1501: return t;
1502: }
1503:
1.1.1.2 root 1504: /* Hashing of types so that we don't make duplicates.
1505: The entry point is `type_hash_canon'. */
1506:
1507: /* Each hash table slot is a bucket containing a chain
1508: of these structures. */
1509:
1510: struct type_hash
1511: {
1512: struct type_hash *next; /* Next structure in the bucket. */
1513: int hashcode; /* Hash code of this type. */
1514: tree type; /* The type recorded here. */
1515: };
1516:
1517: /* Now here is the hash table. When recording a type, it is added
1518: to the slot whose index is the hash code mod the table size.
1519: Note that the hash table is used for several kinds of types
1520: (function types, array types and array index range types, for now).
1521: While all these live in the same table, they are completely independent,
1522: and the hash code is computed differently for each of these. */
1523:
1.1.1.7 root 1524: #define TYPE_HASH_SIZE 59
1.1.1.2 root 1525: struct type_hash *type_hash_table[TYPE_HASH_SIZE];
1526:
1527: /* Here is how primitive or already-canonicalized types' hash
1528: codes are made. */
1529: #define TYPE_HASH(TYPE) TREE_UID (TYPE)
1530:
1531: /* Compute a hash code for a list of types (chain of TREE_LIST nodes
1532: with types in the TREE_VALUE slots), by adding the hash codes
1533: of the individual types. */
1534:
1535: int
1536: type_hash_list (list)
1537: tree list;
1538: {
1539: register int hashcode;
1540: register tree tail;
1541: for (hashcode = 0, tail = list; tail; tail = TREE_CHAIN (tail))
1542: hashcode += TYPE_HASH (TREE_VALUE (tail));
1543: return hashcode;
1544: }
1545:
1546: /* Look in the type hash table for a type isomorphic to TYPE.
1547: If one is found, return it. Otherwise return 0. */
1548:
1549: tree
1550: type_hash_lookup (hashcode, type)
1551: int hashcode;
1552: tree type;
1553: {
1554: register struct type_hash *h;
1555: for (h = type_hash_table[hashcode % TYPE_HASH_SIZE]; h; h = h->next)
1556: if (h->hashcode == hashcode
1557: && TREE_CODE (h->type) == TREE_CODE (type)
1558: && TREE_TYPE (h->type) == TREE_TYPE (type)
1559: && (TYPE_MAX_VALUE (h->type) == TYPE_MAX_VALUE (type)
1560: || tree_int_cst_equal (TYPE_MAX_VALUE (h->type),
1561: TYPE_MAX_VALUE (type)))
1562: && (TYPE_MIN_VALUE (h->type) == TYPE_MIN_VALUE (type)
1563: || tree_int_cst_equal (TYPE_MIN_VALUE (h->type),
1564: TYPE_MIN_VALUE (type)))
1565: && (TYPE_DOMAIN (h->type) == TYPE_DOMAIN (type)
1566: || (TREE_CODE (TYPE_DOMAIN (h->type)) == TREE_LIST
1567: && TREE_CODE (TYPE_DOMAIN (type)) == TREE_LIST
1568: && type_list_equal (TYPE_DOMAIN (h->type), TYPE_DOMAIN (type)))))
1569: return h->type;
1570: return 0;
1571: }
1572:
1573: /* Add an entry to the type-hash-table
1574: for a type TYPE whose hash code is HASHCODE. */
1575:
1576: void
1577: type_hash_add (hashcode, type)
1578: int hashcode;
1579: tree type;
1580: {
1581: register struct type_hash *h;
1582:
1583: h = (struct type_hash *) oballoc (sizeof (struct type_hash));
1584: h->hashcode = hashcode;
1585: h->type = type;
1586: h->next = type_hash_table[hashcode % TYPE_HASH_SIZE];
1587: type_hash_table[hashcode % TYPE_HASH_SIZE] = h;
1588: }
1589:
1590: /* Given TYPE, and HASHCODE its hash code, return the canonical
1591: object for an identical type if one already exists.
1592: Otherwise, return TYPE, and record it as the canonical object
1593: if it is a permanent object.
1594:
1595: To use this function, first create a type of the sort you want.
1596: Then compute its hash code from the fields of the type that
1597: make it different from other similar types.
1598: Then call this function and use the value.
1599: This function frees the type you pass in if it is a duplicate. */
1600:
1601: /* Set to 1 to debug without canonicalization. Never set by program. */
1602: int debug_no_type_hash = 0;
1603:
1604: tree
1605: type_hash_canon (hashcode, type)
1606: int hashcode;
1607: tree type;
1608: {
1609: tree t1;
1610:
1611: if (debug_no_type_hash)
1612: return type;
1613:
1614: t1 = type_hash_lookup (hashcode, type);
1615: if (t1 != 0)
1616: {
1617: struct obstack *o
1618: = TREE_PERMANENT (type) ? &permanent_obstack : saveable_obstack;
1619: obstack_free (o, type);
1620: return t1;
1621: }
1622:
1623: /* If this is a new type, record it for later reuse. */
1624: if (current_obstack == &permanent_obstack)
1625: type_hash_add (hashcode, type);
1626:
1627: return type;
1628: }
1629:
1630: /* Given two lists of types
1631: (chains of TREE_LIST nodes with types in the TREE_VALUE slots)
1.1.1.7 root 1632: return 1 if the lists contain the same types in the same order.
1633: Also, the TREE_PURPOSEs must match. */
1.1.1.2 root 1634:
1635: int
1636: type_list_equal (l1, l2)
1637: tree l1, l2;
1638: {
1639: register tree t1, t2;
1640: for (t1 = l1, t2 = l2; t1 && t2; t1 = TREE_CHAIN (t1), t2 = TREE_CHAIN (t2))
1.1.1.7 root 1641: {
1642: if (TREE_VALUE (t1) != TREE_VALUE (t2))
1643: return 0;
1644: if (TREE_PURPOSE (t1) != TREE_PURPOSE (t2)
1645: && !simple_cst_equal (TREE_PURPOSE (t1), TREE_PURPOSE (t2)))
1646: return 0;
1647: }
1.1.1.2 root 1648:
1649: return t1 == t2;
1650: }
1651:
1652: /* Nonzero if integer constants T1 and T2
1653: represent the same constant value. */
1654:
1655: int
1656: tree_int_cst_equal (t1, t2)
1657: tree t1, t2;
1658: {
1659: if (t1 == t2)
1660: return 1;
1661: if (t1 == 0 || t2 == 0)
1662: return 0;
1663: if (TREE_CODE (t1) == INTEGER_CST
1664: && TREE_CODE (t2) == INTEGER_CST
1665: && TREE_INT_CST_LOW (t1) == TREE_INT_CST_LOW (t2)
1666: && TREE_INT_CST_HIGH (t1) == TREE_INT_CST_HIGH (t2))
1667: return 1;
1668: return 0;
1669: }
1670:
1671: /* Nonzero if integer constants T1 and T2 represent values that satisfy <.
1672: The precise way of comparison depends on their data type. */
1673:
1674: int
1675: tree_int_cst_lt (t1, t2)
1676: tree t1, t2;
1677: {
1678: if (t1 == t2)
1679: return 0;
1680:
1681: if (!TREE_UNSIGNED (TREE_TYPE (t1)))
1682: return INT_CST_LT (t1, t2);
1683: return INT_CST_LT_UNSIGNED (t1, t2);
1684: }
1.1.1.7 root 1685:
1686: /* Compare two constructor-element-type constants. */
1687:
1688: int
1689: simple_cst_equal (t1, t2)
1690: tree t1, t2;
1691: {
1692: register enum tree_code code1, code2;
1693:
1694: if (t1 == t2)
1695: return 1;
1696: if (t1 == 0 || t2 == 0)
1697: return 0;
1698:
1699: code1 = TREE_CODE (t1);
1700: code2 = TREE_CODE (t2);
1701:
1702: if (code1 == NOP_EXPR || code1 == CONVERT_EXPR)
1703: if (code2 == NOP_EXPR || code2 == CONVERT_EXPR)
1704: return simple_cst_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
1705: else
1706: return simple_cst_equal (TREE_OPERAND (t1, 0), t2);
1707: else if (code2 == NOP_EXPR || code2 == CONVERT_EXPR)
1708: return simple_cst_equal (t1, TREE_OPERAND (t2, 0));
1709:
1710: if (code1 != code2)
1711: return 0;
1712:
1713: switch (code1)
1714: {
1715: case INTEGER_CST:
1716: return TREE_INT_CST_LOW (t1) == TREE_INT_CST_LOW (t2)
1717: && TREE_INT_CST_HIGH (t1) == TREE_INT_CST_HIGH (t2);
1718:
1719: case REAL_CST:
1.1.1.12 root 1720: return REAL_VALUES_EQUAL (TREE_REAL_CST (t1), TREE_REAL_CST (t2));
1.1.1.7 root 1721:
1722: case STRING_CST:
1723: return TREE_STRING_LENGTH (t1) == TREE_STRING_LENGTH (t2)
1724: && !strcmp (TREE_STRING_POINTER (t1), TREE_STRING_POINTER (t2));
1725:
1726: case CONSTRUCTOR:
1727: abort ();
1728:
1729: case VAR_DECL:
1730: case PARM_DECL:
1731: case CONST_DECL:
1732: return 0;
1733:
1734: case PLUS_EXPR:
1735: case MINUS_EXPR:
1736: case MULT_EXPR:
1737: case TRUNC_DIV_EXPR:
1738: case TRUNC_MOD_EXPR:
1739: case LSHIFT_EXPR:
1740: case RSHIFT_EXPR:
1741: return (simple_cst_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0))
1742: && simple_cst_equal (TREE_OPERAND (t1, 1), TREE_OPERAND (t2, 1)));
1743:
1744: case NEGATE_EXPR:
1745: case ADDR_EXPR:
1746: case REFERENCE_EXPR:
1.1.1.15 root 1747: case INDIRECT_REF:
1.1.1.7 root 1748: return simple_cst_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
1749:
1750: default:
1751: abort ();
1752: }
1753: }
1.1.1.2 root 1754:
1.1 root 1755: /* Constructors for pointer, array and function types.
1756: (RECORD_TYPE, UNION_TYPE and ENUMERAL_TYPE nodes are
1757: constructed by language-dependent code, not here.) */
1758:
1.1.1.2 root 1759: /* Construct, lay out and return the type of pointers to TO_TYPE.
1760: If such a type has already been constructed, reuse it. */
1761:
1.1 root 1762: tree
1763: build_pointer_type (to_type)
1764: tree to_type;
1765: {
1766: register tree t = TYPE_POINTER_TO (to_type);
1767: register struct obstack *ambient_obstack = current_obstack;
1.1.1.4 root 1768: register struct obstack *ambient_saveable_obstack = saveable_obstack;
1.1 root 1769:
1770: /* First, if we already have a type for pointers to TO_TYPE, use it. */
1771:
1772: if (t)
1773: return t;
1774:
1775: /* We need a new one. If TO_TYPE is permanent, make this permanent too. */
1.1.1.4 root 1776: if (TREE_PERMANENT (to_type))
1777: {
1778: current_obstack = &permanent_obstack;
1779: saveable_obstack = &permanent_obstack;
1780: }
1.1 root 1781:
1782: t = make_node (POINTER_TYPE);
1783: TREE_TYPE (t) = to_type;
1784:
1785: /* Record this type as the pointer to TO_TYPE. */
1786: TYPE_POINTER_TO (to_type) = t;
1787:
1.1.1.2 root 1788: /* Lay out the type. This function has many callers that are concerned
1789: with expression-construction, and this simplifies them all.
1790: Also, it guarantees the TYPE_SIZE is permanent if the type is. */
1791: layout_type (t);
1.1 root 1792:
1793: current_obstack = ambient_obstack;
1.1.1.4 root 1794: saveable_obstack = ambient_saveable_obstack;
1.1 root 1795: return t;
1796: }
1797:
1.1.1.8 root 1798: /* Create a type of integers to be the TYPE_DOMAIN of an ARRAY_TYPE.
1799: MAXVAL should be the maximum value in the domain
1800: (one less than the length of the array). */
1801:
1802: tree
1803: build_index_type (maxval)
1804: tree maxval;
1805: {
1806: register tree itype = make_node (INTEGER_TYPE);
1807: TYPE_PRECISION (itype) = BITS_PER_WORD;
1808: TYPE_MIN_VALUE (itype) = build_int_2 (0, 0);
1.1.1.15 root 1809: TREE_TYPE (TYPE_MIN_VALUE (itype)) = sizetype;
1810: TYPE_MAX_VALUE (itype) = convert (sizetype, maxval);
1.1.1.8 root 1811: TYPE_MODE (itype) = SImode;
1812: TYPE_SIZE (itype) = TYPE_SIZE (sizetype);
1813: TYPE_SIZE_UNIT (itype) = TYPE_SIZE_UNIT (sizetype);
1814: TYPE_ALIGN (itype) = TYPE_ALIGN (sizetype);
1.1.1.17! root 1815: if (TREE_CODE (maxval) == INTEGER_CST)
! 1816: {
! 1817: int maxint = TREE_INT_CST_LOW (maxval);
! 1818: return type_hash_canon (maxint > 0 ? maxint : - maxint, itype);
! 1819: }
! 1820: else
! 1821: return itype;
1.1.1.8 root 1822: }
1823:
1.1.1.2 root 1824: /* Construct, lay out and return the type of arrays of elements with ELT_TYPE
1825: and number of elements specified by the range of values of INDEX_TYPE.
1826: If such a type has already been constructed, reuse it. */
1827:
1.1 root 1828: tree
1829: build_array_type (elt_type, index_type)
1830: tree elt_type, index_type;
1831: {
1832: register tree t = make_node (ARRAY_TYPE);
1.1.1.2 root 1833: int hashcode;
1.1 root 1834:
1835: if (TREE_CODE (elt_type) == FUNCTION_TYPE)
1836: {
1.1.1.2 root 1837: error ("arrays of functions are not meaningful");
1.1 root 1838: elt_type = integer_type_node;
1839: }
1840:
1841: TREE_TYPE (t) = elt_type;
1842: TYPE_DOMAIN (t) = index_type;
1.1.1.2 root 1843:
1.1 root 1844: /* Make sure TYPE_POINTER_TO (elt_type) is filled in. */
1845: build_pointer_type (elt_type);
1.1.1.17! root 1846: #if 0
! 1847: /* Also that of the main variant, which is the type the element will have. */
! 1848: build_pointer_type (TYPE_MAIN_VARIANT (elt_type));
! 1849: #endif
1.1.1.2 root 1850:
1851: if (index_type == 0)
1852: return t;
1853:
1854: hashcode = TYPE_HASH (elt_type) + TYPE_HASH (index_type);
1855: t = type_hash_canon (hashcode, t);
1856:
1857: if (TYPE_SIZE (t) == 0)
1858: layout_type (t);
1.1 root 1859: return t;
1860: }
1861:
1.1.1.2 root 1862: /* Construct, lay out and return
1863: the type of functions returning type VALUE_TYPE
1864: given arguments of types ARG_TYPES.
1865: ARG_TYPES is a chain of TREE_LIST nodes whose TREE_VALUEs
1866: are data type nodes for the arguments of the function.
1867: If such a type has already been constructed, reuse it. */
1.1 root 1868:
1869: tree
1870: build_function_type (value_type, arg_types)
1871: tree value_type, arg_types;
1872: {
1873: register tree t;
1.1.1.2 root 1874: int hashcode;
1.1 root 1875:
1.1.1.2 root 1876: if (TREE_CODE (value_type) == FUNCTION_TYPE
1.1 root 1877: || TREE_CODE (value_type) == ARRAY_TYPE)
1878: {
1.1.1.2 root 1879: error ("function return type cannot be function or array");
1.1 root 1880: value_type = integer_type_node;
1881: }
1882:
1.1.1.2 root 1883: /* Make a node of the sort we want. */
1.1 root 1884: t = make_node (FUNCTION_TYPE);
1885: TREE_TYPE (t) = value_type;
1886: TYPE_ARG_TYPES (t) = arg_types;
1.1.1.2 root 1887:
1888: /* If we already have such a type, use the old one and free this one. */
1889: hashcode = TYPE_HASH (value_type) + type_hash_list (arg_types);
1890: t = type_hash_canon (hashcode, t);
1891:
1892: if (TYPE_SIZE (t) == 0)
1893: layout_type (t);
1.1 root 1894: return t;
1895: }
1.1.1.7 root 1896:
1897: /* Build the node for the type of references-to-TO_TYPE. */
1898:
1899: tree
1900: build_reference_type (to_type)
1901: tree to_type;
1902: {
1903: register tree t = TYPE_REFERENCE_TO (to_type);
1904: register struct obstack *ambient_obstack = current_obstack;
1905: register struct obstack *ambient_saveable_obstack = saveable_obstack;
1906:
1907: /* First, if we already have a type for pointers to TO_TYPE, use it. */
1908:
1909: if (t)
1910: return t;
1911:
1912: /* We need a new one. If TO_TYPE is permanent, make this permanent too. */
1913: if (TREE_PERMANENT (to_type))
1914: {
1915: current_obstack = &permanent_obstack;
1916: saveable_obstack = &permanent_obstack;
1917: }
1918:
1919: t = make_node (REFERENCE_TYPE);
1920: TREE_TYPE (t) = to_type;
1921:
1922: /* Record this type as the pointer to TO_TYPE. */
1923: TYPE_REFERENCE_TO (to_type) = t;
1924:
1925: layout_type (t);
1926:
1927: current_obstack = ambient_obstack;
1928: saveable_obstack = ambient_saveable_obstack;
1929: return t;
1930: }
1931:
1932: /* Construct, lay out and return the type of methods belonging to class
1933: BASETYPE and whose arguments and values are described by TYPE.
1934: If that type exists already, reuse it.
1935: TYPE must be a FUNCTION_TYPE node. */
1936:
1937: tree
1938: build_method_type (basetype, type)
1939: tree basetype, type;
1940: {
1941: register tree t;
1942: int hashcode;
1943:
1944: /* Make a node of the sort we want. */
1945: t = make_node (METHOD_TYPE);
1946:
1947: if (TREE_CODE (type) != FUNCTION_TYPE)
1948: abort ();
1949:
1.1.1.11 root 1950: TYPE_METHOD_BASETYPE (t) = basetype;
1951: TREE_TYPE (t) = TREE_TYPE (type);
1.1.1.7 root 1952:
1953: /* The actual arglist for this function includes a "hidden" argument
1954: which is "this". Put it into the list of argument types. */
1955:
1956: TYPE_ARG_TYPES (t)
1957: = tree_cons (NULL, build_pointer_type (basetype), TYPE_ARG_TYPES (type));
1958:
1959: /* If we already have such a type, use the old one and free this one. */
1960: hashcode = TYPE_HASH (basetype) + TYPE_HASH (type);
1961: t = type_hash_canon (hashcode, t);
1962:
1963: if (TYPE_SIZE (t) == 0)
1964: layout_type (t);
1965:
1966: return t;
1967: }
1.1.1.11 root 1968:
1969: /* Construct, lay out and return the type of methods belonging to class
1970: BASETYPE and whose arguments and values are described by TYPE.
1971: If that type exists already, reuse it.
1972: TYPE must be a FUNCTION_TYPE node. */
1973:
1974: tree
1975: build_offset_type (basetype, type)
1976: tree basetype, type;
1977: {
1978: register tree t;
1979: int hashcode;
1980:
1981: /* Make a node of the sort we want. */
1982: t = make_node (OFFSET_TYPE);
1983:
1984: TYPE_OFFSET_BASETYPE (t) = basetype;
1985: TREE_TYPE (t) = type;
1986:
1987: /* If we already have such a type, use the old one and free this one. */
1988: hashcode = TYPE_HASH (basetype) + TYPE_HASH (type);
1989: t = type_hash_canon (hashcode, t);
1990:
1991: if (TYPE_SIZE (t) == 0)
1992: layout_type (t);
1993:
1994: return t;
1995: }
1.1 root 1996:
1997: /* Return OP, stripped of any conversions to wider types as much as is safe.
1998: Converting the value back to OP's type makes a value equivalent to OP.
1999:
2000: If FOR_TYPE is nonzero, we return a value which, if converted to
2001: type FOR_TYPE, would be equivalent to converting OP to type FOR_TYPE.
2002:
1.1.1.2 root 2003: If FOR_TYPE is nonzero, unaligned bit-field references may be changed to the
2004: narrowest type that can hold the value, even if they don't exactly fit.
2005: Otherwise, bit-field references are changed to a narrower type
2006: only if they can be fetched directly from memory in that type.
2007:
1.1 root 2008: OP must have integer, real or enumeral type. Pointers are not allowed!
2009:
2010: There are some cases where the obvious value we could return
2011: would regenerate to OP if converted to OP's type,
2012: but would not extend like OP to wider types.
2013: If FOR_TYPE indicates such extension is contemplated, we eschew such values.
2014: For example, if OP is (unsigned short)(signed char)-1,
2015: we avoid returning (signed char)-1 if FOR_TYPE is int,
2016: even though extending that to an unsigned short would regenerate OP,
2017: since the result of extending (signed char)-1 to (int)
2018: is different from (int) OP. */
2019:
2020: tree
2021: get_unwidened (op, for_type)
2022: register tree op;
2023: tree for_type;
2024: {
2025: /* Set UNS initially if converting OP to FOR_TYPE is a zero-extension. */
2026: /* TYPE_PRECISION is safe in place of type_precision since
2027: pointer types are not allowed. */
2028: register tree type = TREE_TYPE (op);
2029: register int final_prec = TYPE_PRECISION (for_type != 0 ? for_type : type);
2030: register int uns
2031: = (for_type != 0 && for_type != type
2032: && final_prec > TYPE_PRECISION (type)
1.1.1.2 root 2033: && TREE_UNSIGNED (type));
1.1 root 2034: register tree win = op;
2035:
2036: while (TREE_CODE (op) == NOP_EXPR)
2037: {
2038: register int bitschange
2039: = TYPE_PRECISION (TREE_TYPE (op))
2040: - TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (op, 0)));
2041:
2042: /* Truncations are many-one so cannot be removed.
2043: Unless we are later going to truncate down even farther. */
2044: if (bitschange < 0
2045: && final_prec > TYPE_PRECISION (TREE_TYPE (op)))
2046: break;
2047:
2048: /* See what's inside this conversion. If we decide to strip it,
2049: we will set WIN. */
2050: op = TREE_OPERAND (op, 0);
2051:
2052: /* If we have not stripped any zero-extensions (uns is 0),
2053: we can strip any kind of extension.
2054: If we have previously stripped a zero-extension,
2055: only zero-extensions can safely be stripped.
2056: Any extension can be stripped if the bits it would produce
2057: are all going to be discarded later by truncating to FOR_TYPE. */
2058:
2059: if (bitschange > 0)
2060: {
2061: if (! uns || final_prec <= TYPE_PRECISION (TREE_TYPE (op)))
2062: win = op;
1.1.1.2 root 2063: /* TREE_UNSIGNED says whether this is a zero-extension.
1.1 root 2064: Let's avoid computing it if it does not affect WIN
2065: and if UNS will not be needed again. */
2066: if ((uns || TREE_CODE (op) == NOP_EXPR)
1.1.1.2 root 2067: && TREE_UNSIGNED (TREE_TYPE (op)))
1.1 root 2068: {
2069: uns = 1;
2070: win = op;
2071: }
2072: }
2073: }
2074:
1.1.1.2 root 2075: if (TREE_CODE (op) == COMPONENT_REF
2076: /* Since type_for_size always gives an integer type. */
2077: && TREE_CODE (type) != REAL_TYPE)
2078: {
2079: int innerprec = (TREE_INT_CST_LOW (DECL_SIZE (TREE_OPERAND (op, 1)))
2080: * DECL_SIZE_UNIT (TREE_OPERAND (op, 1)));
2081: type = type_for_size (innerprec, TREE_UNSIGNED (TREE_OPERAND (op, 1)));
2082:
2083: /* We can get this structure field in the narrowest type it fits in.
2084: If FOR_TYPE is 0, do this only for a field that matches the
2085: narrower type exactly and is aligned for it (i.e. mode isn't BI).
2086: The resulting extension to its nominal type (a fullword type)
2087: must fit the same conditions as for other extensions. */
2088:
1.1.1.3 root 2089: if (innerprec < TYPE_PRECISION (TREE_TYPE (op))
1.1.1.2 root 2090: && (for_type || DECL_MODE (TREE_OPERAND (op, 1)) != BImode)
2091: && (! uns || final_prec <= innerprec
2092: || TREE_UNSIGNED (TREE_OPERAND (op, 1)))
2093: && type != 0)
2094: {
2095: win = build (COMPONENT_REF, type, TREE_OPERAND (op, 0),
2096: TREE_OPERAND (op, 1));
2097: TREE_VOLATILE (win) = TREE_VOLATILE (op);
2098: TREE_THIS_VOLATILE (win) = TREE_THIS_VOLATILE (op);
2099: }
2100: }
1.1 root 2101: return win;
2102: }
2103:
2104: /* Return OP or a simpler expression for a narrower value
2105: which can be sign-extended or zero-extended to give back OP.
2106: Store in *UNSIGNEDP_PTR either 1 if the value should be zero-extended
2107: or 0 if the value should be sign-extended. */
2108:
2109: tree
2110: get_narrower (op, unsignedp_ptr)
2111: register tree op;
2112: int *unsignedp_ptr;
2113: {
2114: register int uns = 0;
2115: int first = 1;
2116: register tree win = op;
2117:
2118: while (TREE_CODE (op) == NOP_EXPR)
2119: {
2120: register int bitschange
2121: = TYPE_PRECISION (TREE_TYPE (op))
2122: - TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (op, 0)));
2123:
2124: /* Truncations are many-one so cannot be removed. */
2125: if (bitschange < 0)
2126: break;
2127:
2128: /* See what's inside this conversion. If we decide to strip it,
2129: we will set WIN. */
2130: op = TREE_OPERAND (op, 0);
2131:
2132: if (bitschange > 0)
2133: {
2134: /* An extension: the outermost one can be stripped,
2135: but remember whether it is zero or sign extension. */
2136: if (first)
1.1.1.2 root 2137: uns = TREE_UNSIGNED (TREE_TYPE (op));
1.1 root 2138: /* Otherwise, if a sign extension has been stripped,
2139: only sign extensions can now be stripped;
2140: if a zero extension has been stripped, only zero-extensions. */
1.1.1.2 root 2141: else if (uns != TREE_UNSIGNED (TREE_TYPE (op)))
1.1 root 2142: break;
2143: first = 0;
2144: }
2145: /* A change in nominal type can always be stripped. */
2146:
2147: win = op;
2148: }
2149:
1.1.1.2 root 2150: if (TREE_CODE (op) == COMPONENT_REF
2151: /* Since type_for_size always gives an integer type. */
2152: && TREE_CODE (TREE_TYPE (op)) != REAL_TYPE)
1.1 root 2153: {
2154: int innerprec = (TREE_INT_CST_LOW (DECL_SIZE (TREE_OPERAND (op, 1)))
2155: * DECL_SIZE_UNIT (TREE_OPERAND (op, 1)));
1.1.1.2 root 2156: tree type = type_for_size (innerprec, TREE_UNSIGNED (op));
1.1 root 2157:
2158: /* We can get this structure field in a narrower type that fits it,
2159: but the resulting extension to its nominal type (a fullword type)
1.1.1.2 root 2160: must satisfy the same conditions as for other extensions.
2161:
2162: Do this only for fields that are aligned (not BImode),
2163: because when bit-field insns will be used there is no
2164: advantage in doing this. */
1.1 root 2165:
2166: if (innerprec < TYPE_PRECISION (TREE_TYPE (op))
1.1.1.2 root 2167: && DECL_MODE (TREE_OPERAND (op, 1)) != BImode
2168: && (first || uns == TREE_UNSIGNED (TREE_OPERAND (op, 1)))
1.1 root 2169: && type != 0)
2170: {
1.1.1.2 root 2171: if (first)
2172: uns = TREE_UNSIGNED (TREE_OPERAND (op, 1));
2173: win = build (COMPONENT_REF, type, TREE_OPERAND (op, 0),
2174: TREE_OPERAND (op, 1));
2175: TREE_VOLATILE (win) = TREE_VOLATILE (op);
2176: TREE_THIS_VOLATILE (win) = TREE_THIS_VOLATILE (op);
1.1 root 2177: }
2178: }
2179: *unsignedp_ptr = uns;
2180: return win;
2181: }
2182:
2183: /* Return the precision of a type, for arithmetic purposes.
2184: Supports all types on which arithmetic is possible
2185: (including pointer types).
2186: It's not clear yet what will be right for complex types. */
2187:
2188: int
2189: type_precision (type)
2190: register tree type;
2191: {
2192: return ((TREE_CODE (type) == INTEGER_TYPE
2193: || TREE_CODE (type) == ENUMERAL_TYPE
2194: || TREE_CODE (type) == REAL_TYPE)
1.1.1.2 root 2195: ? TYPE_PRECISION (type) : POINTER_SIZE);
1.1 root 2196: }
2197:
2198: /* Nonzero if integer constant C has a value that is permissible
2199: for type TYPE (an INTEGER_TYPE). */
2200:
2201: int
2202: int_fits_type_p (c, type)
2203: tree c, type;
2204: {
1.1.1.2 root 2205: if (TREE_UNSIGNED (type))
1.1 root 2206: return (!INT_CST_LT_UNSIGNED (TYPE_MAX_VALUE (type), c)
2207: && !INT_CST_LT_UNSIGNED (c, TYPE_MIN_VALUE (type)));
2208: else
2209: return (!INT_CST_LT (TYPE_MAX_VALUE (type), c)
2210: && !INT_CST_LT (c, TYPE_MIN_VALUE (type)));
2211: }
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