tree-vn.c (vn_add): Use XNEW.
[gcc.git] / gcc / gimplify.c
1 /* Tree lowering pass. This pass converts the GENERIC functions-as-trees
2 tree representation into the GIMPLE form.
3 Copyright (C) 2002, 2003, 2004, 2005 Free Software Foundation, Inc.
4 Major work done by Sebastian Pop <s.pop@laposte.net>,
5 Diego Novillo <dnovillo@redhat.com> and Jason Merrill <jason@redhat.com>.
6
7 This file is part of GCC.
8
9 GCC is free software; you can redistribute it and/or modify it under
10 the terms of the GNU General Public License as published by the Free
11 Software Foundation; either version 2, or (at your option) any later
12 version.
13
14 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
15 WARRANTY; without even the implied warranty of MERCHANTABILITY or
16 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
17 for more details.
18
19 You should have received a copy of the GNU General Public License
20 along with GCC; see the file COPYING. If not, write to the Free
21 Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA
22 02110-1301, USA. */
23
24 #include "config.h"
25 #include "system.h"
26 #include "coretypes.h"
27 #include "tm.h"
28 #include "tree.h"
29 #include "rtl.h"
30 #include "varray.h"
31 #include "tree-gimple.h"
32 #include "tree-inline.h"
33 #include "diagnostic.h"
34 #include "langhooks.h"
35 #include "langhooks-def.h"
36 #include "tree-flow.h"
37 #include "cgraph.h"
38 #include "timevar.h"
39 #include "except.h"
40 #include "hashtab.h"
41 #include "flags.h"
42 #include "real.h"
43 #include "function.h"
44 #include "output.h"
45 #include "expr.h"
46 #include "ggc.h"
47 #include "toplev.h"
48 #include "target.h"
49
50 static struct gimplify_ctx
51 {
52 tree current_bind_expr;
53 tree temps;
54 tree conditional_cleanups;
55 tree exit_label;
56 tree return_temp;
57 VEC(tree,heap) *case_labels;
58 /* The formal temporary table. Should this be persistent? */
59 htab_t temp_htab;
60 int conditions;
61 bool save_stack;
62 bool into_ssa;
63 } *gimplify_ctxp;
64
65
66 /* Formal (expression) temporary table handling: Multiple occurrences of
67 the same scalar expression are evaluated into the same temporary. */
68
69 typedef struct gimple_temp_hash_elt
70 {
71 tree val; /* Key */
72 tree temp; /* Value */
73 } elt_t;
74
75 /* Forward declarations. */
76 static enum gimplify_status gimplify_compound_expr (tree *, tree *, bool);
77 #ifdef ENABLE_CHECKING
78 static bool cpt_same_type (tree a, tree b);
79 #endif
80
81
82 /* Return a hash value for a formal temporary table entry. */
83
84 static hashval_t
85 gimple_tree_hash (const void *p)
86 {
87 tree t = ((const elt_t *) p)->val;
88 return iterative_hash_expr (t, 0);
89 }
90
91 /* Compare two formal temporary table entries. */
92
93 static int
94 gimple_tree_eq (const void *p1, const void *p2)
95 {
96 tree t1 = ((const elt_t *) p1)->val;
97 tree t2 = ((const elt_t *) p2)->val;
98 enum tree_code code = TREE_CODE (t1);
99
100 if (TREE_CODE (t2) != code
101 || TREE_TYPE (t1) != TREE_TYPE (t2))
102 return 0;
103
104 if (!operand_equal_p (t1, t2, 0))
105 return 0;
106
107 /* Only allow them to compare equal if they also hash equal; otherwise
108 results are nondeterminate, and we fail bootstrap comparison. */
109 gcc_assert (gimple_tree_hash (p1) == gimple_tree_hash (p2));
110
111 return 1;
112 }
113
114 /* Set up a context for the gimplifier. */
115
116 void
117 push_gimplify_context (void)
118 {
119 gcc_assert (!gimplify_ctxp);
120 gimplify_ctxp
121 = (struct gimplify_ctx *) xcalloc (1, sizeof (struct gimplify_ctx));
122 if (optimize)
123 gimplify_ctxp->temp_htab
124 = htab_create (1000, gimple_tree_hash, gimple_tree_eq, free);
125 else
126 gimplify_ctxp->temp_htab = NULL;
127 }
128
129 /* Tear down a context for the gimplifier. If BODY is non-null, then
130 put the temporaries into the outer BIND_EXPR. Otherwise, put them
131 in the unexpanded_var_list. */
132
133 void
134 pop_gimplify_context (tree body)
135 {
136 tree t;
137
138 gcc_assert (gimplify_ctxp && !gimplify_ctxp->current_bind_expr);
139
140 for (t = gimplify_ctxp->temps; t ; t = TREE_CHAIN (t))
141 DECL_GIMPLE_FORMAL_TEMP_P (t) = 0;
142
143 if (body)
144 declare_tmp_vars (gimplify_ctxp->temps, body);
145 else
146 record_vars (gimplify_ctxp->temps);
147
148 #if 0
149 if (!quiet_flag && optimize)
150 fprintf (stderr, " collisions: %f ",
151 htab_collisions (gimplify_ctxp->temp_htab));
152 #endif
153
154 if (optimize)
155 htab_delete (gimplify_ctxp->temp_htab);
156 free (gimplify_ctxp);
157 gimplify_ctxp = NULL;
158 }
159
160 static void
161 gimple_push_bind_expr (tree bind)
162 {
163 TREE_CHAIN (bind) = gimplify_ctxp->current_bind_expr;
164 gimplify_ctxp->current_bind_expr = bind;
165 }
166
167 static void
168 gimple_pop_bind_expr (void)
169 {
170 gimplify_ctxp->current_bind_expr
171 = TREE_CHAIN (gimplify_ctxp->current_bind_expr);
172 }
173
174 tree
175 gimple_current_bind_expr (void)
176 {
177 return gimplify_ctxp->current_bind_expr;
178 }
179
180 /* Returns true iff there is a COND_EXPR between us and the innermost
181 CLEANUP_POINT_EXPR. This info is used by gimple_push_cleanup. */
182
183 static bool
184 gimple_conditional_context (void)
185 {
186 return gimplify_ctxp->conditions > 0;
187 }
188
189 /* Note that we've entered a COND_EXPR. */
190
191 static void
192 gimple_push_condition (void)
193 {
194 #ifdef ENABLE_CHECKING
195 if (gimplify_ctxp->conditions == 0)
196 gcc_assert (!gimplify_ctxp->conditional_cleanups);
197 #endif
198 ++(gimplify_ctxp->conditions);
199 }
200
201 /* Note that we've left a COND_EXPR. If we're back at unconditional scope
202 now, add any conditional cleanups we've seen to the prequeue. */
203
204 static void
205 gimple_pop_condition (tree *pre_p)
206 {
207 int conds = --(gimplify_ctxp->conditions);
208
209 gcc_assert (conds >= 0);
210 if (conds == 0)
211 {
212 append_to_statement_list (gimplify_ctxp->conditional_cleanups, pre_p);
213 gimplify_ctxp->conditional_cleanups = NULL_TREE;
214 }
215 }
216
217 /* A subroutine of append_to_statement_list{,_force}. T is not NULL. */
218
219 static void
220 append_to_statement_list_1 (tree t, tree *list_p)
221 {
222 tree list = *list_p;
223 tree_stmt_iterator i;
224
225 if (!list)
226 {
227 if (t && TREE_CODE (t) == STATEMENT_LIST)
228 {
229 *list_p = t;
230 return;
231 }
232 *list_p = list = alloc_stmt_list ();
233 }
234
235 i = tsi_last (list);
236 tsi_link_after (&i, t, TSI_CONTINUE_LINKING);
237 }
238
239 /* Add T to the end of the list container pointed to by LIST_P.
240 If T is an expression with no effects, it is ignored. */
241
242 void
243 append_to_statement_list (tree t, tree *list_p)
244 {
245 if (t && TREE_SIDE_EFFECTS (t))
246 append_to_statement_list_1 (t, list_p);
247 }
248
249 /* Similar, but the statement is always added, regardless of side effects. */
250
251 void
252 append_to_statement_list_force (tree t, tree *list_p)
253 {
254 if (t != NULL_TREE)
255 append_to_statement_list_1 (t, list_p);
256 }
257
258 /* Both gimplify the statement T and append it to LIST_P. */
259
260 void
261 gimplify_and_add (tree t, tree *list_p)
262 {
263 gimplify_stmt (&t);
264 append_to_statement_list (t, list_p);
265 }
266
267 /* Strip off a legitimate source ending from the input string NAME of
268 length LEN. Rather than having to know the names used by all of
269 our front ends, we strip off an ending of a period followed by
270 up to five characters. (Java uses ".class".) */
271
272 static inline void
273 remove_suffix (char *name, int len)
274 {
275 int i;
276
277 for (i = 2; i < 8 && len > i; i++)
278 {
279 if (name[len - i] == '.')
280 {
281 name[len - i] = '\0';
282 break;
283 }
284 }
285 }
286
287 /* Create a nameless artificial label and put it in the current function
288 context. Returns the newly created label. */
289
290 tree
291 create_artificial_label (void)
292 {
293 tree lab = build_decl (LABEL_DECL, NULL_TREE, void_type_node);
294
295 DECL_ARTIFICIAL (lab) = 1;
296 DECL_IGNORED_P (lab) = 1;
297 DECL_CONTEXT (lab) = current_function_decl;
298 return lab;
299 }
300
301 /* Subroutine for find_single_pointer_decl. */
302
303 static tree
304 find_single_pointer_decl_1 (tree *tp, int *walk_subtrees ATTRIBUTE_UNUSED,
305 void *data)
306 {
307 tree *pdecl = (tree *) data;
308
309 if (DECL_P (*tp) && POINTER_TYPE_P (TREE_TYPE (*tp)))
310 {
311 if (*pdecl)
312 {
313 /* We already found a pointer decl; return anything other
314 than NULL_TREE to unwind from walk_tree signalling that
315 we have a duplicate. */
316 return *tp;
317 }
318 *pdecl = *tp;
319 }
320
321 return NULL_TREE;
322 }
323
324 /* Find the single DECL of pointer type in the tree T and return it.
325 If there are zero or more than one such DECLs, return NULL. */
326
327 static tree
328 find_single_pointer_decl (tree t)
329 {
330 tree decl = NULL_TREE;
331
332 if (walk_tree (&t, find_single_pointer_decl_1, &decl, NULL))
333 {
334 /* find_single_pointer_decl_1 returns a non-zero value, causing
335 walk_tree to return a non-zero value, to indicate that it
336 found more than one pointer DECL. */
337 return NULL_TREE;
338 }
339
340 return decl;
341 }
342
343 /* Create a new temporary name with PREFIX. Returns an identifier. */
344
345 static GTY(()) unsigned int tmp_var_id_num;
346
347 tree
348 create_tmp_var_name (const char *prefix)
349 {
350 char *tmp_name;
351
352 if (prefix)
353 {
354 char *preftmp = ASTRDUP (prefix);
355
356 remove_suffix (preftmp, strlen (preftmp));
357 prefix = preftmp;
358 }
359
360 ASM_FORMAT_PRIVATE_NAME (tmp_name, prefix ? prefix : "T", tmp_var_id_num++);
361 return get_identifier (tmp_name);
362 }
363
364
365 /* Create a new temporary variable declaration of type TYPE.
366 Does NOT push it into the current binding. */
367
368 tree
369 create_tmp_var_raw (tree type, const char *prefix)
370 {
371 tree tmp_var;
372 tree new_type;
373
374 /* Make the type of the variable writable. */
375 new_type = build_type_variant (type, 0, 0);
376 TYPE_ATTRIBUTES (new_type) = TYPE_ATTRIBUTES (type);
377
378 tmp_var = build_decl (VAR_DECL, prefix ? create_tmp_var_name (prefix) : NULL,
379 type);
380
381 /* The variable was declared by the compiler. */
382 DECL_ARTIFICIAL (tmp_var) = 1;
383 /* And we don't want debug info for it. */
384 DECL_IGNORED_P (tmp_var) = 1;
385
386 /* Make the variable writable. */
387 TREE_READONLY (tmp_var) = 0;
388
389 DECL_EXTERNAL (tmp_var) = 0;
390 TREE_STATIC (tmp_var) = 0;
391 TREE_USED (tmp_var) = 1;
392
393 return tmp_var;
394 }
395
396 /* Create a new temporary variable declaration of type TYPE. DOES push the
397 variable into the current binding. Further, assume that this is called
398 only from gimplification or optimization, at which point the creation of
399 certain types are bugs. */
400
401 tree
402 create_tmp_var (tree type, const char *prefix)
403 {
404 tree tmp_var;
405
406 /* We don't allow types that are addressable (meaning we can't make copies),
407 incomplete, or of variable size. */
408 gcc_assert (!TREE_ADDRESSABLE (type)
409 && COMPLETE_TYPE_P (type)
410 && TREE_CODE (TYPE_SIZE_UNIT (type)) == INTEGER_CST);
411
412 tmp_var = create_tmp_var_raw (type, prefix);
413 gimple_add_tmp_var (tmp_var);
414 return tmp_var;
415 }
416
417 /* Given a tree, try to return a useful variable name that we can use
418 to prefix a temporary that is being assigned the value of the tree.
419 I.E. given <temp> = &A, return A. */
420
421 const char *
422 get_name (tree t)
423 {
424 tree stripped_decl;
425
426 stripped_decl = t;
427 STRIP_NOPS (stripped_decl);
428 if (DECL_P (stripped_decl) && DECL_NAME (stripped_decl))
429 return IDENTIFIER_POINTER (DECL_NAME (stripped_decl));
430 else
431 {
432 switch (TREE_CODE (stripped_decl))
433 {
434 case ADDR_EXPR:
435 return get_name (TREE_OPERAND (stripped_decl, 0));
436 break;
437 default:
438 return NULL;
439 }
440 }
441 }
442
443 /* Create a temporary with a name derived from VAL. Subroutine of
444 lookup_tmp_var; nobody else should call this function. */
445
446 static inline tree
447 create_tmp_from_val (tree val)
448 {
449 return create_tmp_var (TYPE_MAIN_VARIANT (TREE_TYPE (val)), get_name (val));
450 }
451
452 /* Create a temporary to hold the value of VAL. If IS_FORMAL, try to reuse
453 an existing expression temporary. */
454
455 static tree
456 lookup_tmp_var (tree val, bool is_formal)
457 {
458 tree ret;
459
460 /* If not optimizing, never really reuse a temporary. local-alloc
461 won't allocate any variable that is used in more than one basic
462 block, which means it will go into memory, causing much extra
463 work in reload and final and poorer code generation, outweighing
464 the extra memory allocation here. */
465 if (!optimize || !is_formal || TREE_SIDE_EFFECTS (val))
466 ret = create_tmp_from_val (val);
467 else
468 {
469 elt_t elt, *elt_p;
470 void **slot;
471
472 elt.val = val;
473 slot = htab_find_slot (gimplify_ctxp->temp_htab, (void *)&elt, INSERT);
474 if (*slot == NULL)
475 {
476 elt_p = XNEW (elt_t);
477 elt_p->val = val;
478 elt_p->temp = ret = create_tmp_from_val (val);
479 *slot = (void *) elt_p;
480 }
481 else
482 {
483 elt_p = (elt_t *) *slot;
484 ret = elt_p->temp;
485 }
486 }
487
488 if (is_formal)
489 DECL_GIMPLE_FORMAL_TEMP_P (ret) = 1;
490
491 return ret;
492 }
493
494 /* Returns a formal temporary variable initialized with VAL. PRE_P is as
495 in gimplify_expr. Only use this function if:
496
497 1) The value of the unfactored expression represented by VAL will not
498 change between the initialization and use of the temporary, and
499 2) The temporary will not be otherwise modified.
500
501 For instance, #1 means that this is inappropriate for SAVE_EXPR temps,
502 and #2 means it is inappropriate for && temps.
503
504 For other cases, use get_initialized_tmp_var instead. */
505
506 static tree
507 internal_get_tmp_var (tree val, tree *pre_p, tree *post_p, bool is_formal)
508 {
509 tree t, mod;
510
511 gimplify_expr (&val, pre_p, post_p, is_gimple_formal_tmp_rhs, fb_rvalue);
512
513 t = lookup_tmp_var (val, is_formal);
514
515 if (is_formal)
516 {
517 tree u = find_single_pointer_decl (val);
518
519 if (u && TREE_CODE (u) == VAR_DECL && DECL_BASED_ON_RESTRICT_P (u))
520 u = DECL_GET_RESTRICT_BASE (u);
521 if (u && TYPE_RESTRICT (TREE_TYPE (u)))
522 {
523 if (DECL_BASED_ON_RESTRICT_P (t))
524 gcc_assert (u == DECL_GET_RESTRICT_BASE (t));
525 else
526 {
527 DECL_BASED_ON_RESTRICT_P (t) = 1;
528 SET_DECL_RESTRICT_BASE (t, u);
529 }
530 }
531 }
532
533 if (TREE_CODE (TREE_TYPE (t)) == COMPLEX_TYPE)
534 DECL_COMPLEX_GIMPLE_REG_P (t) = 1;
535
536 mod = build2 (MODIFY_EXPR, TREE_TYPE (t), t, val);
537
538 if (EXPR_HAS_LOCATION (val))
539 SET_EXPR_LOCUS (mod, EXPR_LOCUS (val));
540 else
541 SET_EXPR_LOCATION (mod, input_location);
542
543 /* gimplify_modify_expr might want to reduce this further. */
544 gimplify_and_add (mod, pre_p);
545
546 /* If we're gimplifying into ssa, gimplify_modify_expr will have
547 given our temporary an ssa name. Find and return it. */
548 if (gimplify_ctxp->into_ssa)
549 t = TREE_OPERAND (mod, 0);
550
551 return t;
552 }
553
554 tree
555 get_formal_tmp_var (tree val, tree *pre_p)
556 {
557 return internal_get_tmp_var (val, pre_p, NULL, true);
558 }
559
560 /* Returns a temporary variable initialized with VAL. PRE_P and POST_P
561 are as in gimplify_expr. */
562
563 tree
564 get_initialized_tmp_var (tree val, tree *pre_p, tree *post_p)
565 {
566 return internal_get_tmp_var (val, pre_p, post_p, false);
567 }
568
569 /* Declares all the variables in VARS in SCOPE. */
570
571 void
572 declare_tmp_vars (tree vars, tree scope)
573 {
574 tree last = vars;
575 if (last)
576 {
577 tree temps;
578
579 /* C99 mode puts the default 'return 0;' for main outside the outer
580 braces. So drill down until we find an actual scope. */
581 while (TREE_CODE (scope) == COMPOUND_EXPR)
582 scope = TREE_OPERAND (scope, 0);
583
584 gcc_assert (TREE_CODE (scope) == BIND_EXPR);
585
586 temps = nreverse (last);
587 TREE_CHAIN (last) = BIND_EXPR_VARS (scope);
588 BIND_EXPR_VARS (scope) = temps;
589 }
590 }
591
592 void
593 gimple_add_tmp_var (tree tmp)
594 {
595 gcc_assert (!TREE_CHAIN (tmp) && !DECL_SEEN_IN_BIND_EXPR_P (tmp));
596
597 DECL_CONTEXT (tmp) = current_function_decl;
598 DECL_SEEN_IN_BIND_EXPR_P (tmp) = 1;
599
600 if (gimplify_ctxp)
601 {
602 TREE_CHAIN (tmp) = gimplify_ctxp->temps;
603 gimplify_ctxp->temps = tmp;
604 }
605 else if (cfun)
606 record_vars (tmp);
607 else
608 declare_tmp_vars (tmp, DECL_SAVED_TREE (current_function_decl));
609 }
610
611 /* Determines whether to assign a locus to the statement STMT. */
612
613 static bool
614 should_carry_locus_p (tree stmt)
615 {
616 /* Don't emit a line note for a label. We particularly don't want to
617 emit one for the break label, since it doesn't actually correspond
618 to the beginning of the loop/switch. */
619 if (TREE_CODE (stmt) == LABEL_EXPR)
620 return false;
621
622 /* Do not annotate empty statements, since it confuses gcov. */
623 if (!TREE_SIDE_EFFECTS (stmt))
624 return false;
625
626 return true;
627 }
628
629 static void
630 annotate_one_with_locus (tree t, location_t locus)
631 {
632 if (EXPR_P (t) && ! EXPR_HAS_LOCATION (t) && should_carry_locus_p (t))
633 SET_EXPR_LOCATION (t, locus);
634 }
635
636 void
637 annotate_all_with_locus (tree *stmt_p, location_t locus)
638 {
639 tree_stmt_iterator i;
640
641 if (!*stmt_p)
642 return;
643
644 for (i = tsi_start (*stmt_p); !tsi_end_p (i); tsi_next (&i))
645 {
646 tree t = tsi_stmt (i);
647
648 /* Assuming we've already been gimplified, we shouldn't
649 see nested chaining constructs anymore. */
650 gcc_assert (TREE_CODE (t) != STATEMENT_LIST
651 && TREE_CODE (t) != COMPOUND_EXPR);
652
653 annotate_one_with_locus (t, locus);
654 }
655 }
656
657 /* Similar to copy_tree_r() but do not copy SAVE_EXPR or TARGET_EXPR nodes.
658 These nodes model computations that should only be done once. If we
659 were to unshare something like SAVE_EXPR(i++), the gimplification
660 process would create wrong code. */
661
662 static tree
663 mostly_copy_tree_r (tree *tp, int *walk_subtrees, void *data)
664 {
665 enum tree_code code = TREE_CODE (*tp);
666 /* Don't unshare types, decls, constants and SAVE_EXPR nodes. */
667 if (TREE_CODE_CLASS (code) == tcc_type
668 || TREE_CODE_CLASS (code) == tcc_declaration
669 || TREE_CODE_CLASS (code) == tcc_constant
670 || code == SAVE_EXPR || code == TARGET_EXPR
671 /* We can't do anything sensible with a BLOCK used as an expression,
672 but we also can't just die when we see it because of non-expression
673 uses. So just avert our eyes and cross our fingers. Silly Java. */
674 || code == BLOCK)
675 *walk_subtrees = 0;
676 else
677 {
678 gcc_assert (code != BIND_EXPR);
679 copy_tree_r (tp, walk_subtrees, data);
680 }
681
682 return NULL_TREE;
683 }
684
685 /* Callback for walk_tree to unshare most of the shared trees rooted at
686 *TP. If *TP has been visited already (i.e., TREE_VISITED (*TP) == 1),
687 then *TP is deep copied by calling copy_tree_r.
688
689 This unshares the same trees as copy_tree_r with the exception of
690 SAVE_EXPR nodes. These nodes model computations that should only be
691 done once. If we were to unshare something like SAVE_EXPR(i++), the
692 gimplification process would create wrong code. */
693
694 static tree
695 copy_if_shared_r (tree *tp, int *walk_subtrees ATTRIBUTE_UNUSED,
696 void *data ATTRIBUTE_UNUSED)
697 {
698 tree t = *tp;
699 enum tree_code code = TREE_CODE (t);
700
701 /* Skip types, decls, and constants. But we do want to look at their
702 types and the bounds of types. Mark them as visited so we properly
703 unmark their subtrees on the unmark pass. If we've already seen them,
704 don't look down further. */
705 if (TREE_CODE_CLASS (code) == tcc_type
706 || TREE_CODE_CLASS (code) == tcc_declaration
707 || TREE_CODE_CLASS (code) == tcc_constant)
708 {
709 if (TREE_VISITED (t))
710 *walk_subtrees = 0;
711 else
712 TREE_VISITED (t) = 1;
713 }
714
715 /* If this node has been visited already, unshare it and don't look
716 any deeper. */
717 else if (TREE_VISITED (t))
718 {
719 walk_tree (tp, mostly_copy_tree_r, NULL, NULL);
720 *walk_subtrees = 0;
721 }
722
723 /* Otherwise, mark the tree as visited and keep looking. */
724 else
725 TREE_VISITED (t) = 1;
726
727 return NULL_TREE;
728 }
729
730 static tree
731 unmark_visited_r (tree *tp, int *walk_subtrees ATTRIBUTE_UNUSED,
732 void *data ATTRIBUTE_UNUSED)
733 {
734 if (TREE_VISITED (*tp))
735 TREE_VISITED (*tp) = 0;
736 else
737 *walk_subtrees = 0;
738
739 return NULL_TREE;
740 }
741
742 /* Unshare all the trees in BODY_P, a pointer into the body of FNDECL, and the
743 bodies of any nested functions if we are unsharing the entire body of
744 FNDECL. */
745
746 static void
747 unshare_body (tree *body_p, tree fndecl)
748 {
749 struct cgraph_node *cgn = cgraph_node (fndecl);
750
751 walk_tree (body_p, copy_if_shared_r, NULL, NULL);
752 if (body_p == &DECL_SAVED_TREE (fndecl))
753 for (cgn = cgn->nested; cgn; cgn = cgn->next_nested)
754 unshare_body (&DECL_SAVED_TREE (cgn->decl), cgn->decl);
755 }
756
757 /* Likewise, but mark all trees as not visited. */
758
759 static void
760 unvisit_body (tree *body_p, tree fndecl)
761 {
762 struct cgraph_node *cgn = cgraph_node (fndecl);
763
764 walk_tree (body_p, unmark_visited_r, NULL, NULL);
765 if (body_p == &DECL_SAVED_TREE (fndecl))
766 for (cgn = cgn->nested; cgn; cgn = cgn->next_nested)
767 unvisit_body (&DECL_SAVED_TREE (cgn->decl), cgn->decl);
768 }
769
770 /* Unshare T and all the trees reached from T via TREE_CHAIN. */
771
772 static void
773 unshare_all_trees (tree t)
774 {
775 walk_tree (&t, copy_if_shared_r, NULL, NULL);
776 walk_tree (&t, unmark_visited_r, NULL, NULL);
777 }
778
779 /* Unconditionally make an unshared copy of EXPR. This is used when using
780 stored expressions which span multiple functions, such as BINFO_VTABLE,
781 as the normal unsharing process can't tell that they're shared. */
782
783 tree
784 unshare_expr (tree expr)
785 {
786 walk_tree (&expr, mostly_copy_tree_r, NULL, NULL);
787 return expr;
788 }
789
790 /* A terser interface for building a representation of an exception
791 specification. */
792
793 tree
794 gimple_build_eh_filter (tree body, tree allowed, tree failure)
795 {
796 tree t;
797
798 /* FIXME should the allowed types go in TREE_TYPE? */
799 t = build2 (EH_FILTER_EXPR, void_type_node, allowed, NULL_TREE);
800 append_to_statement_list (failure, &EH_FILTER_FAILURE (t));
801
802 t = build2 (TRY_CATCH_EXPR, void_type_node, NULL_TREE, t);
803 append_to_statement_list (body, &TREE_OPERAND (t, 0));
804
805 return t;
806 }
807
808 \f
809 /* WRAPPER is a code such as BIND_EXPR or CLEANUP_POINT_EXPR which can both
810 contain statements and have a value. Assign its value to a temporary
811 and give it void_type_node. Returns the temporary, or NULL_TREE if
812 WRAPPER was already void. */
813
814 tree
815 voidify_wrapper_expr (tree wrapper, tree temp)
816 {
817 if (!VOID_TYPE_P (TREE_TYPE (wrapper)))
818 {
819 tree *p, sub = wrapper;
820
821 restart:
822 /* Set p to point to the body of the wrapper. */
823 switch (TREE_CODE (sub))
824 {
825 case BIND_EXPR:
826 /* For a BIND_EXPR, the body is operand 1. */
827 p = &BIND_EXPR_BODY (sub);
828 break;
829
830 default:
831 p = &TREE_OPERAND (sub, 0);
832 break;
833 }
834
835 /* Advance to the last statement. Set all container types to void. */
836 if (TREE_CODE (*p) == STATEMENT_LIST)
837 {
838 tree_stmt_iterator i = tsi_last (*p);
839 p = tsi_end_p (i) ? NULL : tsi_stmt_ptr (i);
840 }
841 else
842 {
843 for (; TREE_CODE (*p) == COMPOUND_EXPR; p = &TREE_OPERAND (*p, 1))
844 {
845 TREE_SIDE_EFFECTS (*p) = 1;
846 TREE_TYPE (*p) = void_type_node;
847 }
848 }
849
850 if (p == NULL || IS_EMPTY_STMT (*p))
851 ;
852 /* Look through exception handling. */
853 else if (TREE_CODE (*p) == TRY_FINALLY_EXPR
854 || TREE_CODE (*p) == TRY_CATCH_EXPR)
855 {
856 sub = *p;
857 goto restart;
858 }
859 /* The C++ frontend already did this for us. */
860 else if (TREE_CODE (*p) == INIT_EXPR
861 || TREE_CODE (*p) == TARGET_EXPR)
862 temp = TREE_OPERAND (*p, 0);
863 /* If we're returning a dereference, move the dereference
864 outside the wrapper. */
865 else if (TREE_CODE (*p) == INDIRECT_REF)
866 {
867 tree ptr = TREE_OPERAND (*p, 0);
868 temp = create_tmp_var (TREE_TYPE (ptr), "retval");
869 *p = build2 (MODIFY_EXPR, TREE_TYPE (ptr), temp, ptr);
870 temp = build1 (INDIRECT_REF, TREE_TYPE (TREE_TYPE (temp)), temp);
871 /* If this is a BIND_EXPR for a const inline function, it might not
872 have TREE_SIDE_EFFECTS set. That is no longer accurate. */
873 TREE_SIDE_EFFECTS (wrapper) = 1;
874 }
875 else
876 {
877 if (!temp)
878 temp = create_tmp_var (TREE_TYPE (wrapper), "retval");
879 *p = build2 (MODIFY_EXPR, TREE_TYPE (temp), temp, *p);
880 TREE_SIDE_EFFECTS (wrapper) = 1;
881 }
882
883 TREE_TYPE (wrapper) = void_type_node;
884 return temp;
885 }
886
887 return NULL_TREE;
888 }
889
890 /* Prepare calls to builtins to SAVE and RESTORE the stack as well as
891 a temporary through which they communicate. */
892
893 static void
894 build_stack_save_restore (tree *save, tree *restore)
895 {
896 tree save_call, tmp_var;
897
898 save_call =
899 build_function_call_expr (implicit_built_in_decls[BUILT_IN_STACK_SAVE],
900 NULL_TREE);
901 tmp_var = create_tmp_var (ptr_type_node, "saved_stack");
902
903 *save = build2 (MODIFY_EXPR, ptr_type_node, tmp_var, save_call);
904 *restore =
905 build_function_call_expr (implicit_built_in_decls[BUILT_IN_STACK_RESTORE],
906 tree_cons (NULL_TREE, tmp_var, NULL_TREE));
907 }
908
909 /* Gimplify a BIND_EXPR. Just voidify and recurse. */
910
911 static enum gimplify_status
912 gimplify_bind_expr (tree *expr_p, tree temp, tree *pre_p)
913 {
914 tree bind_expr = *expr_p;
915 bool old_save_stack = gimplify_ctxp->save_stack;
916 tree t;
917
918 temp = voidify_wrapper_expr (bind_expr, temp);
919
920 /* Mark variables seen in this bind expr. */
921 for (t = BIND_EXPR_VARS (bind_expr); t ; t = TREE_CHAIN (t))
922 {
923 if (TREE_CODE (t) == VAR_DECL)
924 DECL_SEEN_IN_BIND_EXPR_P (t) = 1;
925
926 /* Preliminarily mark non-addressed complex variables as eligible
927 for promotion to gimple registers. We'll transform their uses
928 as we find them. */
929 if (TREE_CODE (TREE_TYPE (t)) == COMPLEX_TYPE
930 && !TREE_THIS_VOLATILE (t)
931 && (TREE_CODE (t) == VAR_DECL && !DECL_HARD_REGISTER (t))
932 && !needs_to_live_in_memory (t))
933 DECL_COMPLEX_GIMPLE_REG_P (t) = 1;
934 }
935
936 gimple_push_bind_expr (bind_expr);
937 gimplify_ctxp->save_stack = false;
938
939 gimplify_to_stmt_list (&BIND_EXPR_BODY (bind_expr));
940
941 if (gimplify_ctxp->save_stack)
942 {
943 tree stack_save, stack_restore;
944
945 /* Save stack on entry and restore it on exit. Add a try_finally
946 block to achieve this. Note that mudflap depends on the
947 format of the emitted code: see mx_register_decls(). */
948 build_stack_save_restore (&stack_save, &stack_restore);
949
950 t = build2 (TRY_FINALLY_EXPR, void_type_node,
951 BIND_EXPR_BODY (bind_expr), NULL_TREE);
952 append_to_statement_list (stack_restore, &TREE_OPERAND (t, 1));
953
954 BIND_EXPR_BODY (bind_expr) = NULL_TREE;
955 append_to_statement_list (stack_save, &BIND_EXPR_BODY (bind_expr));
956 append_to_statement_list (t, &BIND_EXPR_BODY (bind_expr));
957 }
958
959 gimplify_ctxp->save_stack = old_save_stack;
960 gimple_pop_bind_expr ();
961
962 if (temp)
963 {
964 *expr_p = temp;
965 append_to_statement_list (bind_expr, pre_p);
966 return GS_OK;
967 }
968 else
969 return GS_ALL_DONE;
970 }
971
972 /* Gimplify a RETURN_EXPR. If the expression to be returned is not a
973 GIMPLE value, it is assigned to a new temporary and the statement is
974 re-written to return the temporary.
975
976 PRE_P points to the list where side effects that must happen before
977 STMT should be stored. */
978
979 static enum gimplify_status
980 gimplify_return_expr (tree stmt, tree *pre_p)
981 {
982 tree ret_expr = TREE_OPERAND (stmt, 0);
983 tree result_decl, result;
984
985 if (!ret_expr || TREE_CODE (ret_expr) == RESULT_DECL
986 || ret_expr == error_mark_node)
987 return GS_ALL_DONE;
988
989 if (VOID_TYPE_P (TREE_TYPE (TREE_TYPE (current_function_decl))))
990 result_decl = NULL_TREE;
991 else
992 {
993 result_decl = TREE_OPERAND (ret_expr, 0);
994 if (TREE_CODE (result_decl) == INDIRECT_REF)
995 /* See through a return by reference. */
996 result_decl = TREE_OPERAND (result_decl, 0);
997
998 gcc_assert ((TREE_CODE (ret_expr) == MODIFY_EXPR
999 || TREE_CODE (ret_expr) == INIT_EXPR)
1000 && TREE_CODE (result_decl) == RESULT_DECL);
1001 }
1002
1003 /* If aggregate_value_p is true, then we can return the bare RESULT_DECL.
1004 Recall that aggregate_value_p is FALSE for any aggregate type that is
1005 returned in registers. If we're returning values in registers, then
1006 we don't want to extend the lifetime of the RESULT_DECL, particularly
1007 across another call. In addition, for those aggregates for which
1008 hard_function_value generates a PARALLEL, we'll die during normal
1009 expansion of structure assignments; there's special code in expand_return
1010 to handle this case that does not exist in expand_expr. */
1011 if (!result_decl
1012 || aggregate_value_p (result_decl, TREE_TYPE (current_function_decl)))
1013 result = result_decl;
1014 else if (gimplify_ctxp->return_temp)
1015 result = gimplify_ctxp->return_temp;
1016 else
1017 {
1018 result = create_tmp_var (TREE_TYPE (result_decl), NULL);
1019
1020 /* ??? With complex control flow (usually involving abnormal edges),
1021 we can wind up warning about an uninitialized value for this. Due
1022 to how this variable is constructed and initialized, this is never
1023 true. Give up and never warn. */
1024 TREE_NO_WARNING (result) = 1;
1025
1026 gimplify_ctxp->return_temp = result;
1027 }
1028
1029 /* Smash the lhs of the MODIFY_EXPR to the temporary we plan to use.
1030 Then gimplify the whole thing. */
1031 if (result != result_decl)
1032 TREE_OPERAND (ret_expr, 0) = result;
1033
1034 gimplify_and_add (TREE_OPERAND (stmt, 0), pre_p);
1035
1036 /* If we didn't use a temporary, then the result is just the result_decl.
1037 Otherwise we need a simple copy. This should already be gimple. */
1038 if (result == result_decl)
1039 ret_expr = result;
1040 else
1041 ret_expr = build2 (MODIFY_EXPR, TREE_TYPE (result), result_decl, result);
1042 TREE_OPERAND (stmt, 0) = ret_expr;
1043
1044 return GS_ALL_DONE;
1045 }
1046
1047 /* Gimplifies a DECL_EXPR node *STMT_P by making any necessary allocation
1048 and initialization explicit. */
1049
1050 static enum gimplify_status
1051 gimplify_decl_expr (tree *stmt_p)
1052 {
1053 tree stmt = *stmt_p;
1054 tree decl = DECL_EXPR_DECL (stmt);
1055
1056 *stmt_p = NULL_TREE;
1057
1058 if (TREE_TYPE (decl) == error_mark_node)
1059 return GS_ERROR;
1060
1061 if ((TREE_CODE (decl) == TYPE_DECL
1062 || TREE_CODE (decl) == VAR_DECL)
1063 && !TYPE_SIZES_GIMPLIFIED (TREE_TYPE (decl)))
1064 gimplify_type_sizes (TREE_TYPE (decl), stmt_p);
1065
1066 if (TREE_CODE (decl) == VAR_DECL && !DECL_EXTERNAL (decl))
1067 {
1068 tree init = DECL_INITIAL (decl);
1069
1070 if (!TREE_CONSTANT (DECL_SIZE (decl)))
1071 {
1072 /* This is a variable-sized decl. Simplify its size and mark it
1073 for deferred expansion. Note that mudflap depends on the format
1074 of the emitted code: see mx_register_decls(). */
1075 tree t, args, addr, ptr_type;
1076
1077 gimplify_one_sizepos (&DECL_SIZE (decl), stmt_p);
1078 gimplify_one_sizepos (&DECL_SIZE_UNIT (decl), stmt_p);
1079
1080 /* All occurrences of this decl in final gimplified code will be
1081 replaced by indirection. Setting DECL_VALUE_EXPR does two
1082 things: First, it lets the rest of the gimplifier know what
1083 replacement to use. Second, it lets the debug info know
1084 where to find the value. */
1085 ptr_type = build_pointer_type (TREE_TYPE (decl));
1086 addr = create_tmp_var (ptr_type, get_name (decl));
1087 DECL_IGNORED_P (addr) = 0;
1088 t = build_fold_indirect_ref (addr);
1089 SET_DECL_VALUE_EXPR (decl, t);
1090 DECL_HAS_VALUE_EXPR_P (decl) = 1;
1091
1092 args = tree_cons (NULL, DECL_SIZE_UNIT (decl), NULL);
1093 t = built_in_decls[BUILT_IN_ALLOCA];
1094 t = build_function_call_expr (t, args);
1095 t = fold_convert (ptr_type, t);
1096 t = build2 (MODIFY_EXPR, void_type_node, addr, t);
1097
1098 gimplify_and_add (t, stmt_p);
1099
1100 /* Indicate that we need to restore the stack level when the
1101 enclosing BIND_EXPR is exited. */
1102 gimplify_ctxp->save_stack = true;
1103 }
1104
1105 if (init && init != error_mark_node)
1106 {
1107 if (!TREE_STATIC (decl))
1108 {
1109 DECL_INITIAL (decl) = NULL_TREE;
1110 init = build2 (MODIFY_EXPR, void_type_node, decl, init);
1111 gimplify_and_add (init, stmt_p);
1112 }
1113 else
1114 /* We must still examine initializers for static variables
1115 as they may contain a label address. */
1116 walk_tree (&init, force_labels_r, NULL, NULL);
1117 }
1118
1119 /* This decl isn't mentioned in the enclosing block, so add it to the
1120 list of temps. FIXME it seems a bit of a kludge to say that
1121 anonymous artificial vars aren't pushed, but everything else is. */
1122 if (DECL_ARTIFICIAL (decl) && DECL_NAME (decl) == NULL_TREE)
1123 gimple_add_tmp_var (decl);
1124 }
1125
1126 return GS_ALL_DONE;
1127 }
1128
1129 /* Gimplify a LOOP_EXPR. Normally this just involves gimplifying the body
1130 and replacing the LOOP_EXPR with goto, but if the loop contains an
1131 EXIT_EXPR, we need to append a label for it to jump to. */
1132
1133 static enum gimplify_status
1134 gimplify_loop_expr (tree *expr_p, tree *pre_p)
1135 {
1136 tree saved_label = gimplify_ctxp->exit_label;
1137 tree start_label = build1 (LABEL_EXPR, void_type_node, NULL_TREE);
1138 tree jump_stmt = build_and_jump (&LABEL_EXPR_LABEL (start_label));
1139
1140 append_to_statement_list (start_label, pre_p);
1141
1142 gimplify_ctxp->exit_label = NULL_TREE;
1143
1144 gimplify_and_add (LOOP_EXPR_BODY (*expr_p), pre_p);
1145
1146 if (gimplify_ctxp->exit_label)
1147 {
1148 append_to_statement_list (jump_stmt, pre_p);
1149 *expr_p = build1 (LABEL_EXPR, void_type_node, gimplify_ctxp->exit_label);
1150 }
1151 else
1152 *expr_p = jump_stmt;
1153
1154 gimplify_ctxp->exit_label = saved_label;
1155
1156 return GS_ALL_DONE;
1157 }
1158
1159 /* Compare two case labels. Because the front end should already have
1160 made sure that case ranges do not overlap, it is enough to only compare
1161 the CASE_LOW values of each case label. */
1162
1163 static int
1164 compare_case_labels (const void *p1, const void *p2)
1165 {
1166 tree case1 = *(tree *)p1;
1167 tree case2 = *(tree *)p2;
1168
1169 return tree_int_cst_compare (CASE_LOW (case1), CASE_LOW (case2));
1170 }
1171
1172 /* Sort the case labels in LABEL_VEC in place in ascending order. */
1173
1174 void
1175 sort_case_labels (tree label_vec)
1176 {
1177 size_t len = TREE_VEC_LENGTH (label_vec);
1178 tree default_case = TREE_VEC_ELT (label_vec, len - 1);
1179
1180 if (CASE_LOW (default_case))
1181 {
1182 size_t i;
1183
1184 /* The last label in the vector should be the default case
1185 but it is not. */
1186 for (i = 0; i < len; ++i)
1187 {
1188 tree t = TREE_VEC_ELT (label_vec, i);
1189 if (!CASE_LOW (t))
1190 {
1191 default_case = t;
1192 TREE_VEC_ELT (label_vec, i) = TREE_VEC_ELT (label_vec, len - 1);
1193 TREE_VEC_ELT (label_vec, len - 1) = default_case;
1194 break;
1195 }
1196 }
1197 }
1198
1199 qsort (&TREE_VEC_ELT (label_vec, 0), len - 1, sizeof (tree),
1200 compare_case_labels);
1201 }
1202
1203 /* Gimplify a SWITCH_EXPR, and collect a TREE_VEC of the labels it can
1204 branch to. */
1205
1206 static enum gimplify_status
1207 gimplify_switch_expr (tree *expr_p, tree *pre_p)
1208 {
1209 tree switch_expr = *expr_p;
1210 enum gimplify_status ret;
1211
1212 ret = gimplify_expr (&SWITCH_COND (switch_expr), pre_p, NULL,
1213 is_gimple_val, fb_rvalue);
1214
1215 if (SWITCH_BODY (switch_expr))
1216 {
1217 VEC(tree,heap) *labels, *saved_labels;
1218 tree label_vec, default_case = NULL_TREE;
1219 size_t i, len;
1220
1221 /* If someone can be bothered to fill in the labels, they can
1222 be bothered to null out the body too. */
1223 gcc_assert (!SWITCH_LABELS (switch_expr));
1224
1225 saved_labels = gimplify_ctxp->case_labels;
1226 gimplify_ctxp->case_labels = VEC_alloc (tree, heap, 8);
1227
1228 gimplify_to_stmt_list (&SWITCH_BODY (switch_expr));
1229
1230 labels = gimplify_ctxp->case_labels;
1231 gimplify_ctxp->case_labels = saved_labels;
1232
1233 len = VEC_length (tree, labels);
1234
1235 for (i = 0; i < len; ++i)
1236 {
1237 tree t = VEC_index (tree, labels, i);
1238 if (!CASE_LOW (t))
1239 {
1240 /* The default case must be the last label in the list. */
1241 default_case = t;
1242 VEC_replace (tree, labels, i, VEC_index (tree, labels, len - 1));
1243 len--;
1244 break;
1245 }
1246 }
1247
1248 label_vec = make_tree_vec (len + 1);
1249 SWITCH_LABELS (*expr_p) = label_vec;
1250 append_to_statement_list (switch_expr, pre_p);
1251
1252 if (! default_case)
1253 {
1254 /* If the switch has no default label, add one, so that we jump
1255 around the switch body. */
1256 default_case = build3 (CASE_LABEL_EXPR, void_type_node, NULL_TREE,
1257 NULL_TREE, create_artificial_label ());
1258 append_to_statement_list (SWITCH_BODY (switch_expr), pre_p);
1259 *expr_p = build1 (LABEL_EXPR, void_type_node,
1260 CASE_LABEL (default_case));
1261 }
1262 else
1263 *expr_p = SWITCH_BODY (switch_expr);
1264
1265 for (i = 0; i < len; ++i)
1266 TREE_VEC_ELT (label_vec, i) = VEC_index (tree, labels, i);
1267 TREE_VEC_ELT (label_vec, len) = default_case;
1268
1269 VEC_free (tree, heap, labels);
1270
1271 sort_case_labels (label_vec);
1272
1273 SWITCH_BODY (switch_expr) = NULL;
1274 }
1275 else
1276 gcc_assert (SWITCH_LABELS (switch_expr));
1277
1278 return ret;
1279 }
1280
1281 static enum gimplify_status
1282 gimplify_case_label_expr (tree *expr_p)
1283 {
1284 tree expr = *expr_p;
1285
1286 gcc_assert (gimplify_ctxp->case_labels);
1287 VEC_safe_push (tree, heap, gimplify_ctxp->case_labels, expr);
1288 *expr_p = build1 (LABEL_EXPR, void_type_node, CASE_LABEL (expr));
1289 return GS_ALL_DONE;
1290 }
1291
1292 /* Build a GOTO to the LABEL_DECL pointed to by LABEL_P, building it first
1293 if necessary. */
1294
1295 tree
1296 build_and_jump (tree *label_p)
1297 {
1298 if (label_p == NULL)
1299 /* If there's nowhere to jump, just fall through. */
1300 return NULL_TREE;
1301
1302 if (*label_p == NULL_TREE)
1303 {
1304 tree label = create_artificial_label ();
1305 *label_p = label;
1306 }
1307
1308 return build1 (GOTO_EXPR, void_type_node, *label_p);
1309 }
1310
1311 /* Gimplify an EXIT_EXPR by converting to a GOTO_EXPR inside a COND_EXPR.
1312 This also involves building a label to jump to and communicating it to
1313 gimplify_loop_expr through gimplify_ctxp->exit_label. */
1314
1315 static enum gimplify_status
1316 gimplify_exit_expr (tree *expr_p)
1317 {
1318 tree cond = TREE_OPERAND (*expr_p, 0);
1319 tree expr;
1320
1321 expr = build_and_jump (&gimplify_ctxp->exit_label);
1322 expr = build3 (COND_EXPR, void_type_node, cond, expr, NULL_TREE);
1323 *expr_p = expr;
1324
1325 return GS_OK;
1326 }
1327
1328 /* A helper function to be called via walk_tree. Mark all labels under *TP
1329 as being forced. To be called for DECL_INITIAL of static variables. */
1330
1331 tree
1332 force_labels_r (tree *tp, int *walk_subtrees, void *data ATTRIBUTE_UNUSED)
1333 {
1334 if (TYPE_P (*tp))
1335 *walk_subtrees = 0;
1336 if (TREE_CODE (*tp) == LABEL_DECL)
1337 FORCED_LABEL (*tp) = 1;
1338
1339 return NULL_TREE;
1340 }
1341
1342 /* *EXPR_P is a COMPONENT_REF being used as an rvalue. If its type is
1343 different from its canonical type, wrap the whole thing inside a
1344 NOP_EXPR and force the type of the COMPONENT_REF to be the canonical
1345 type.
1346
1347 The canonical type of a COMPONENT_REF is the type of the field being
1348 referenced--unless the field is a bit-field which can be read directly
1349 in a smaller mode, in which case the canonical type is the
1350 sign-appropriate type corresponding to that mode. */
1351
1352 static void
1353 canonicalize_component_ref (tree *expr_p)
1354 {
1355 tree expr = *expr_p;
1356 tree type;
1357
1358 gcc_assert (TREE_CODE (expr) == COMPONENT_REF);
1359
1360 if (INTEGRAL_TYPE_P (TREE_TYPE (expr)))
1361 type = TREE_TYPE (get_unwidened (expr, NULL_TREE));
1362 else
1363 type = TREE_TYPE (TREE_OPERAND (expr, 1));
1364
1365 if (TREE_TYPE (expr) != type)
1366 {
1367 tree old_type = TREE_TYPE (expr);
1368
1369 /* Set the type of the COMPONENT_REF to the underlying type. */
1370 TREE_TYPE (expr) = type;
1371
1372 /* And wrap the whole thing inside a NOP_EXPR. */
1373 expr = build1 (NOP_EXPR, old_type, expr);
1374
1375 *expr_p = expr;
1376 }
1377 }
1378
1379 /* If a NOP conversion is changing a pointer to array of foo to a pointer
1380 to foo, embed that change in the ADDR_EXPR by converting
1381 T array[U];
1382 (T *)&array
1383 ==>
1384 &array[L]
1385 where L is the lower bound. For simplicity, only do this for constant
1386 lower bound. */
1387
1388 static void
1389 canonicalize_addr_expr (tree *expr_p)
1390 {
1391 tree expr = *expr_p;
1392 tree ctype = TREE_TYPE (expr);
1393 tree addr_expr = TREE_OPERAND (expr, 0);
1394 tree atype = TREE_TYPE (addr_expr);
1395 tree dctype, datype, ddatype, otype, obj_expr;
1396
1397 /* Both cast and addr_expr types should be pointers. */
1398 if (!POINTER_TYPE_P (ctype) || !POINTER_TYPE_P (atype))
1399 return;
1400
1401 /* The addr_expr type should be a pointer to an array. */
1402 datype = TREE_TYPE (atype);
1403 if (TREE_CODE (datype) != ARRAY_TYPE)
1404 return;
1405
1406 /* Both cast and addr_expr types should address the same object type. */
1407 dctype = TREE_TYPE (ctype);
1408 ddatype = TREE_TYPE (datype);
1409 if (!lang_hooks.types_compatible_p (ddatype, dctype))
1410 return;
1411
1412 /* The addr_expr and the object type should match. */
1413 obj_expr = TREE_OPERAND (addr_expr, 0);
1414 otype = TREE_TYPE (obj_expr);
1415 if (!lang_hooks.types_compatible_p (otype, datype))
1416 return;
1417
1418 /* The lower bound and element sizes must be constant. */
1419 if (!TYPE_SIZE_UNIT (dctype)
1420 || TREE_CODE (TYPE_SIZE_UNIT (dctype)) != INTEGER_CST
1421 || !TYPE_DOMAIN (datype) || !TYPE_MIN_VALUE (TYPE_DOMAIN (datype))
1422 || TREE_CODE (TYPE_MIN_VALUE (TYPE_DOMAIN (datype))) != INTEGER_CST)
1423 return;
1424
1425 /* All checks succeeded. Build a new node to merge the cast. */
1426 *expr_p = build4 (ARRAY_REF, dctype, obj_expr,
1427 TYPE_MIN_VALUE (TYPE_DOMAIN (datype)),
1428 TYPE_MIN_VALUE (TYPE_DOMAIN (datype)),
1429 size_binop (EXACT_DIV_EXPR, TYPE_SIZE_UNIT (dctype),
1430 size_int (TYPE_ALIGN_UNIT (dctype))));
1431 *expr_p = build1 (ADDR_EXPR, ctype, *expr_p);
1432 }
1433
1434 /* *EXPR_P is a NOP_EXPR or CONVERT_EXPR. Remove it and/or other conversions
1435 underneath as appropriate. */
1436
1437 static enum gimplify_status
1438 gimplify_conversion (tree *expr_p)
1439 {
1440 gcc_assert (TREE_CODE (*expr_p) == NOP_EXPR
1441 || TREE_CODE (*expr_p) == CONVERT_EXPR);
1442
1443 /* Then strip away all but the outermost conversion. */
1444 STRIP_SIGN_NOPS (TREE_OPERAND (*expr_p, 0));
1445
1446 /* And remove the outermost conversion if it's useless. */
1447 if (tree_ssa_useless_type_conversion (*expr_p))
1448 *expr_p = TREE_OPERAND (*expr_p, 0);
1449
1450 /* If we still have a conversion at the toplevel,
1451 then canonicalize some constructs. */
1452 if (TREE_CODE (*expr_p) == NOP_EXPR || TREE_CODE (*expr_p) == CONVERT_EXPR)
1453 {
1454 tree sub = TREE_OPERAND (*expr_p, 0);
1455
1456 /* If a NOP conversion is changing the type of a COMPONENT_REF
1457 expression, then canonicalize its type now in order to expose more
1458 redundant conversions. */
1459 if (TREE_CODE (sub) == COMPONENT_REF)
1460 canonicalize_component_ref (&TREE_OPERAND (*expr_p, 0));
1461
1462 /* If a NOP conversion is changing a pointer to array of foo
1463 to a pointer to foo, embed that change in the ADDR_EXPR. */
1464 else if (TREE_CODE (sub) == ADDR_EXPR)
1465 canonicalize_addr_expr (expr_p);
1466 }
1467
1468 return GS_OK;
1469 }
1470
1471 /* Gimplify a VAR_DECL or PARM_DECL. Returns GS_OK if we expanded a
1472 DECL_VALUE_EXPR, and it's worth re-examining things. */
1473
1474 static enum gimplify_status
1475 gimplify_var_or_parm_decl (tree *expr_p)
1476 {
1477 tree decl = *expr_p;
1478
1479 /* ??? If this is a local variable, and it has not been seen in any
1480 outer BIND_EXPR, then it's probably the result of a duplicate
1481 declaration, for which we've already issued an error. It would
1482 be really nice if the front end wouldn't leak these at all.
1483 Currently the only known culprit is C++ destructors, as seen
1484 in g++.old-deja/g++.jason/binding.C. */
1485 if (TREE_CODE (decl) == VAR_DECL
1486 && !DECL_SEEN_IN_BIND_EXPR_P (decl)
1487 && !TREE_STATIC (decl) && !DECL_EXTERNAL (decl)
1488 && decl_function_context (decl) == current_function_decl)
1489 {
1490 gcc_assert (errorcount || sorrycount);
1491 return GS_ERROR;
1492 }
1493
1494 /* If the decl is an alias for another expression, substitute it now. */
1495 if (DECL_HAS_VALUE_EXPR_P (decl))
1496 {
1497 *expr_p = unshare_expr (DECL_VALUE_EXPR (decl));
1498 return GS_OK;
1499 }
1500
1501 return GS_ALL_DONE;
1502 }
1503
1504
1505 /* Gimplify the COMPONENT_REF, ARRAY_REF, REALPART_EXPR or IMAGPART_EXPR
1506 node pointed to by EXPR_P.
1507
1508 compound_lval
1509 : min_lval '[' val ']'
1510 | min_lval '.' ID
1511 | compound_lval '[' val ']'
1512 | compound_lval '.' ID
1513
1514 This is not part of the original SIMPLE definition, which separates
1515 array and member references, but it seems reasonable to handle them
1516 together. Also, this way we don't run into problems with union
1517 aliasing; gcc requires that for accesses through a union to alias, the
1518 union reference must be explicit, which was not always the case when we
1519 were splitting up array and member refs.
1520
1521 PRE_P points to the list where side effects that must happen before
1522 *EXPR_P should be stored.
1523
1524 POST_P points to the list where side effects that must happen after
1525 *EXPR_P should be stored. */
1526
1527 static enum gimplify_status
1528 gimplify_compound_lval (tree *expr_p, tree *pre_p,
1529 tree *post_p, fallback_t fallback)
1530 {
1531 tree *p;
1532 VEC(tree,heap) *stack;
1533 enum gimplify_status ret = GS_OK, tret;
1534 int i;
1535
1536 /* Create a stack of the subexpressions so later we can walk them in
1537 order from inner to outer. */
1538 stack = VEC_alloc (tree, heap, 10);
1539
1540 /* We can handle anything that get_inner_reference can deal with. */
1541 for (p = expr_p; ; p = &TREE_OPERAND (*p, 0))
1542 {
1543 restart:
1544 /* Fold INDIRECT_REFs now to turn them into ARRAY_REFs. */
1545 if (TREE_CODE (*p) == INDIRECT_REF)
1546 *p = fold_indirect_ref (*p);
1547
1548 if (handled_component_p (*p))
1549 ;
1550 /* Expand DECL_VALUE_EXPR now. In some cases that may expose
1551 additional COMPONENT_REFs. */
1552 else if ((TREE_CODE (*p) == VAR_DECL || TREE_CODE (*p) == PARM_DECL)
1553 && gimplify_var_or_parm_decl (p) == GS_OK)
1554 goto restart;
1555 else
1556 break;
1557
1558 VEC_safe_push (tree, heap, stack, *p);
1559 }
1560
1561 gcc_assert (VEC_length (tree, stack));
1562
1563 /* Now STACK is a stack of pointers to all the refs we've walked through
1564 and P points to the innermost expression.
1565
1566 Java requires that we elaborated nodes in source order. That
1567 means we must gimplify the inner expression followed by each of
1568 the indices, in order. But we can't gimplify the inner
1569 expression until we deal with any variable bounds, sizes, or
1570 positions in order to deal with PLACEHOLDER_EXPRs.
1571
1572 So we do this in three steps. First we deal with the annotations
1573 for any variables in the components, then we gimplify the base,
1574 then we gimplify any indices, from left to right. */
1575 for (i = VEC_length (tree, stack) - 1; i >= 0; i--)
1576 {
1577 tree t = VEC_index (tree, stack, i);
1578
1579 if (TREE_CODE (t) == ARRAY_REF || TREE_CODE (t) == ARRAY_RANGE_REF)
1580 {
1581 /* Gimplify the low bound and element type size and put them into
1582 the ARRAY_REF. If these values are set, they have already been
1583 gimplified. */
1584 if (!TREE_OPERAND (t, 2))
1585 {
1586 tree low = unshare_expr (array_ref_low_bound (t));
1587 if (!is_gimple_min_invariant (low))
1588 {
1589 TREE_OPERAND (t, 2) = low;
1590 tret = gimplify_expr (&TREE_OPERAND (t, 2), pre_p, post_p,
1591 is_gimple_formal_tmp_reg, fb_rvalue);
1592 ret = MIN (ret, tret);
1593 }
1594 }
1595
1596 if (!TREE_OPERAND (t, 3))
1597 {
1598 tree elmt_type = TREE_TYPE (TREE_TYPE (TREE_OPERAND (t, 0)));
1599 tree elmt_size = unshare_expr (array_ref_element_size (t));
1600 tree factor = size_int (TYPE_ALIGN_UNIT (elmt_type));
1601
1602 /* Divide the element size by the alignment of the element
1603 type (above). */
1604 elmt_size = size_binop (EXACT_DIV_EXPR, elmt_size, factor);
1605
1606 if (!is_gimple_min_invariant (elmt_size))
1607 {
1608 TREE_OPERAND (t, 3) = elmt_size;
1609 tret = gimplify_expr (&TREE_OPERAND (t, 3), pre_p, post_p,
1610 is_gimple_formal_tmp_reg, fb_rvalue);
1611 ret = MIN (ret, tret);
1612 }
1613 }
1614 }
1615 else if (TREE_CODE (t) == COMPONENT_REF)
1616 {
1617 /* Set the field offset into T and gimplify it. */
1618 if (!TREE_OPERAND (t, 2))
1619 {
1620 tree offset = unshare_expr (component_ref_field_offset (t));
1621 tree field = TREE_OPERAND (t, 1);
1622 tree factor
1623 = size_int (DECL_OFFSET_ALIGN (field) / BITS_PER_UNIT);
1624
1625 /* Divide the offset by its alignment. */
1626 offset = size_binop (EXACT_DIV_EXPR, offset, factor);
1627
1628 if (!is_gimple_min_invariant (offset))
1629 {
1630 TREE_OPERAND (t, 2) = offset;
1631 tret = gimplify_expr (&TREE_OPERAND (t, 2), pre_p, post_p,
1632 is_gimple_formal_tmp_reg, fb_rvalue);
1633 ret = MIN (ret, tret);
1634 }
1635 }
1636 }
1637 }
1638
1639 /* Step 2 is to gimplify the base expression. Make sure lvalue is set
1640 so as to match the min_lval predicate. Failure to do so may result
1641 in the creation of large aggregate temporaries. */
1642 tret = gimplify_expr (p, pre_p, post_p, is_gimple_min_lval,
1643 fallback | fb_lvalue);
1644 ret = MIN (ret, tret);
1645
1646 /* And finally, the indices and operands to BIT_FIELD_REF. During this
1647 loop we also remove any useless conversions. */
1648 for (; VEC_length (tree, stack) > 0; )
1649 {
1650 tree t = VEC_pop (tree, stack);
1651
1652 if (TREE_CODE (t) == ARRAY_REF || TREE_CODE (t) == ARRAY_RANGE_REF)
1653 {
1654 /* Gimplify the dimension.
1655 Temporary fix for gcc.c-torture/execute/20040313-1.c.
1656 Gimplify non-constant array indices into a temporary
1657 variable.
1658 FIXME - The real fix is to gimplify post-modify
1659 expressions into a minimal gimple lvalue. However, that
1660 exposes bugs in alias analysis. The alias analyzer does
1661 not handle &PTR->FIELD very well. Will fix after the
1662 branch is merged into mainline (dnovillo 2004-05-03). */
1663 if (!is_gimple_min_invariant (TREE_OPERAND (t, 1)))
1664 {
1665 tret = gimplify_expr (&TREE_OPERAND (t, 1), pre_p, post_p,
1666 is_gimple_formal_tmp_reg, fb_rvalue);
1667 ret = MIN (ret, tret);
1668 }
1669 }
1670 else if (TREE_CODE (t) == BIT_FIELD_REF)
1671 {
1672 tret = gimplify_expr (&TREE_OPERAND (t, 1), pre_p, post_p,
1673 is_gimple_val, fb_rvalue);
1674 ret = MIN (ret, tret);
1675 tret = gimplify_expr (&TREE_OPERAND (t, 2), pre_p, post_p,
1676 is_gimple_val, fb_rvalue);
1677 ret = MIN (ret, tret);
1678 }
1679
1680 STRIP_USELESS_TYPE_CONVERSION (TREE_OPERAND (t, 0));
1681
1682 /* The innermost expression P may have originally had TREE_SIDE_EFFECTS
1683 set which would have caused all the outer expressions in EXPR_P
1684 leading to P to also have had TREE_SIDE_EFFECTS set. */
1685 recalculate_side_effects (t);
1686 }
1687
1688 tret = gimplify_expr (p, pre_p, post_p, is_gimple_min_lval, fallback);
1689 ret = MIN (ret, tret);
1690
1691 /* If the outermost expression is a COMPONENT_REF, canonicalize its type. */
1692 if ((fallback & fb_rvalue) && TREE_CODE (*expr_p) == COMPONENT_REF)
1693 {
1694 canonicalize_component_ref (expr_p);
1695 ret = MIN (ret, GS_OK);
1696 }
1697
1698 VEC_free (tree, heap, stack);
1699
1700 return ret;
1701 }
1702
1703 /* Gimplify the self modifying expression pointed to by EXPR_P
1704 (++, --, +=, -=).
1705
1706 PRE_P points to the list where side effects that must happen before
1707 *EXPR_P should be stored.
1708
1709 POST_P points to the list where side effects that must happen after
1710 *EXPR_P should be stored.
1711
1712 WANT_VALUE is nonzero iff we want to use the value of this expression
1713 in another expression. */
1714
1715 static enum gimplify_status
1716 gimplify_self_mod_expr (tree *expr_p, tree *pre_p, tree *post_p,
1717 bool want_value)
1718 {
1719 enum tree_code code;
1720 tree lhs, lvalue, rhs, t1;
1721 bool postfix;
1722 enum tree_code arith_code;
1723 enum gimplify_status ret;
1724
1725 code = TREE_CODE (*expr_p);
1726
1727 gcc_assert (code == POSTINCREMENT_EXPR || code == POSTDECREMENT_EXPR
1728 || code == PREINCREMENT_EXPR || code == PREDECREMENT_EXPR);
1729
1730 /* Prefix or postfix? */
1731 if (code == POSTINCREMENT_EXPR || code == POSTDECREMENT_EXPR)
1732 /* Faster to treat as prefix if result is not used. */
1733 postfix = want_value;
1734 else
1735 postfix = false;
1736
1737 /* Add or subtract? */
1738 if (code == PREINCREMENT_EXPR || code == POSTINCREMENT_EXPR)
1739 arith_code = PLUS_EXPR;
1740 else
1741 arith_code = MINUS_EXPR;
1742
1743 /* Gimplify the LHS into a GIMPLE lvalue. */
1744 lvalue = TREE_OPERAND (*expr_p, 0);
1745 ret = gimplify_expr (&lvalue, pre_p, post_p, is_gimple_lvalue, fb_lvalue);
1746 if (ret == GS_ERROR)
1747 return ret;
1748
1749 /* Extract the operands to the arithmetic operation. */
1750 lhs = lvalue;
1751 rhs = TREE_OPERAND (*expr_p, 1);
1752
1753 /* For postfix operator, we evaluate the LHS to an rvalue and then use
1754 that as the result value and in the postqueue operation. */
1755 if (postfix)
1756 {
1757 ret = gimplify_expr (&lhs, pre_p, post_p, is_gimple_val, fb_rvalue);
1758 if (ret == GS_ERROR)
1759 return ret;
1760 }
1761
1762 t1 = build2 (arith_code, TREE_TYPE (*expr_p), lhs, rhs);
1763 t1 = build2 (MODIFY_EXPR, TREE_TYPE (lvalue), lvalue, t1);
1764
1765 if (postfix)
1766 {
1767 gimplify_and_add (t1, post_p);
1768 *expr_p = lhs;
1769 return GS_ALL_DONE;
1770 }
1771 else
1772 {
1773 *expr_p = t1;
1774 return GS_OK;
1775 }
1776 }
1777
1778 /* If *EXPR_P has a variable sized type, wrap it in a WITH_SIZE_EXPR. */
1779
1780 static void
1781 maybe_with_size_expr (tree *expr_p)
1782 {
1783 tree expr = *expr_p;
1784 tree type = TREE_TYPE (expr);
1785 tree size;
1786
1787 /* If we've already wrapped this or the type is error_mark_node, we can't do
1788 anything. */
1789 if (TREE_CODE (expr) == WITH_SIZE_EXPR
1790 || type == error_mark_node)
1791 return;
1792
1793 /* If the size isn't known or is a constant, we have nothing to do. */
1794 size = TYPE_SIZE_UNIT (type);
1795 if (!size || TREE_CODE (size) == INTEGER_CST)
1796 return;
1797
1798 /* Otherwise, make a WITH_SIZE_EXPR. */
1799 size = unshare_expr (size);
1800 size = SUBSTITUTE_PLACEHOLDER_IN_EXPR (size, expr);
1801 *expr_p = build2 (WITH_SIZE_EXPR, type, expr, size);
1802 }
1803
1804 /* Subroutine of gimplify_call_expr: Gimplify a single argument. */
1805
1806 static enum gimplify_status
1807 gimplify_arg (tree *expr_p, tree *pre_p)
1808 {
1809 bool (*test) (tree);
1810 fallback_t fb;
1811
1812 /* In general, we allow lvalues for function arguments to avoid
1813 extra overhead of copying large aggregates out of even larger
1814 aggregates into temporaries only to copy the temporaries to
1815 the argument list. Make optimizers happy by pulling out to
1816 temporaries those types that fit in registers. */
1817 if (is_gimple_reg_type (TREE_TYPE (*expr_p)))
1818 test = is_gimple_val, fb = fb_rvalue;
1819 else
1820 test = is_gimple_lvalue, fb = fb_either;
1821
1822 /* If this is a variable sized type, we must remember the size. */
1823 maybe_with_size_expr (expr_p);
1824
1825 /* There is a sequence point before a function call. Side effects in
1826 the argument list must occur before the actual call. So, when
1827 gimplifying arguments, force gimplify_expr to use an internal
1828 post queue which is then appended to the end of PRE_P. */
1829 return gimplify_expr (expr_p, pre_p, NULL, test, fb);
1830 }
1831
1832 /* Gimplify the CALL_EXPR node pointed to by EXPR_P. PRE_P points to the
1833 list where side effects that must happen before *EXPR_P should be stored.
1834 WANT_VALUE is true if the result of the call is desired. */
1835
1836 static enum gimplify_status
1837 gimplify_call_expr (tree *expr_p, tree *pre_p, bool want_value)
1838 {
1839 tree decl;
1840 tree arglist;
1841 enum gimplify_status ret;
1842
1843 gcc_assert (TREE_CODE (*expr_p) == CALL_EXPR);
1844
1845 /* For reliable diagnostics during inlining, it is necessary that
1846 every call_expr be annotated with file and line. */
1847 if (! EXPR_HAS_LOCATION (*expr_p))
1848 SET_EXPR_LOCATION (*expr_p, input_location);
1849
1850 /* This may be a call to a builtin function.
1851
1852 Builtin function calls may be transformed into different
1853 (and more efficient) builtin function calls under certain
1854 circumstances. Unfortunately, gimplification can muck things
1855 up enough that the builtin expanders are not aware that certain
1856 transformations are still valid.
1857
1858 So we attempt transformation/gimplification of the call before
1859 we gimplify the CALL_EXPR. At this time we do not manage to
1860 transform all calls in the same manner as the expanders do, but
1861 we do transform most of them. */
1862 decl = get_callee_fndecl (*expr_p);
1863 if (decl && DECL_BUILT_IN (decl))
1864 {
1865 tree fndecl = get_callee_fndecl (*expr_p);
1866 tree arglist = TREE_OPERAND (*expr_p, 1);
1867 tree new = fold_builtin (fndecl, arglist, !want_value);
1868
1869 if (new && new != *expr_p)
1870 {
1871 /* There was a transformation of this call which computes the
1872 same value, but in a more efficient way. Return and try
1873 again. */
1874 *expr_p = new;
1875 return GS_OK;
1876 }
1877
1878 if (DECL_BUILT_IN_CLASS (decl) == BUILT_IN_NORMAL
1879 && DECL_FUNCTION_CODE (decl) == BUILT_IN_VA_START)
1880 {
1881 if (!arglist || !TREE_CHAIN (arglist))
1882 {
1883 error ("too few arguments to function %<va_start%>");
1884 *expr_p = build_empty_stmt ();
1885 return GS_OK;
1886 }
1887
1888 if (fold_builtin_next_arg (TREE_CHAIN (arglist)))
1889 {
1890 *expr_p = build_empty_stmt ();
1891 return GS_OK;
1892 }
1893 /* Avoid gimplifying the second argument to va_start, which needs
1894 to be the plain PARM_DECL. */
1895 return gimplify_arg (&TREE_VALUE (TREE_OPERAND (*expr_p, 1)), pre_p);
1896 }
1897 }
1898
1899 /* There is a sequence point before the call, so any side effects in
1900 the calling expression must occur before the actual call. Force
1901 gimplify_expr to use an internal post queue. */
1902 ret = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p, NULL,
1903 is_gimple_call_addr, fb_rvalue);
1904
1905 if (PUSH_ARGS_REVERSED)
1906 TREE_OPERAND (*expr_p, 1) = nreverse (TREE_OPERAND (*expr_p, 1));
1907 for (arglist = TREE_OPERAND (*expr_p, 1); arglist;
1908 arglist = TREE_CHAIN (arglist))
1909 {
1910 enum gimplify_status t;
1911
1912 t = gimplify_arg (&TREE_VALUE (arglist), pre_p);
1913
1914 if (t == GS_ERROR)
1915 ret = GS_ERROR;
1916 }
1917 if (PUSH_ARGS_REVERSED)
1918 TREE_OPERAND (*expr_p, 1) = nreverse (TREE_OPERAND (*expr_p, 1));
1919
1920 /* Try this again in case gimplification exposed something. */
1921 if (ret != GS_ERROR && decl && DECL_BUILT_IN (decl))
1922 {
1923 tree fndecl = get_callee_fndecl (*expr_p);
1924 tree arglist = TREE_OPERAND (*expr_p, 1);
1925 tree new = fold_builtin (fndecl, arglist, !want_value);
1926
1927 if (new && new != *expr_p)
1928 {
1929 /* There was a transformation of this call which computes the
1930 same value, but in a more efficient way. Return and try
1931 again. */
1932 *expr_p = new;
1933 return GS_OK;
1934 }
1935 }
1936
1937 /* If the function is "const" or "pure", then clear TREE_SIDE_EFFECTS on its
1938 decl. This allows us to eliminate redundant or useless
1939 calls to "const" functions. */
1940 if (TREE_CODE (*expr_p) == CALL_EXPR
1941 && (call_expr_flags (*expr_p) & (ECF_CONST | ECF_PURE)))
1942 TREE_SIDE_EFFECTS (*expr_p) = 0;
1943
1944 return ret;
1945 }
1946
1947 /* Handle shortcut semantics in the predicate operand of a COND_EXPR by
1948 rewriting it into multiple COND_EXPRs, and possibly GOTO_EXPRs.
1949
1950 TRUE_LABEL_P and FALSE_LABEL_P point to the labels to jump to if the
1951 condition is true or false, respectively. If null, we should generate
1952 our own to skip over the evaluation of this specific expression.
1953
1954 This function is the tree equivalent of do_jump.
1955
1956 shortcut_cond_r should only be called by shortcut_cond_expr. */
1957
1958 static tree
1959 shortcut_cond_r (tree pred, tree *true_label_p, tree *false_label_p)
1960 {
1961 tree local_label = NULL_TREE;
1962 tree t, expr = NULL;
1963
1964 /* OK, it's not a simple case; we need to pull apart the COND_EXPR to
1965 retain the shortcut semantics. Just insert the gotos here;
1966 shortcut_cond_expr will append the real blocks later. */
1967 if (TREE_CODE (pred) == TRUTH_ANDIF_EXPR)
1968 {
1969 /* Turn if (a && b) into
1970
1971 if (a); else goto no;
1972 if (b) goto yes; else goto no;
1973 (no:) */
1974
1975 if (false_label_p == NULL)
1976 false_label_p = &local_label;
1977
1978 t = shortcut_cond_r (TREE_OPERAND (pred, 0), NULL, false_label_p);
1979 append_to_statement_list (t, &expr);
1980
1981 t = shortcut_cond_r (TREE_OPERAND (pred, 1), true_label_p,
1982 false_label_p);
1983 append_to_statement_list (t, &expr);
1984 }
1985 else if (TREE_CODE (pred) == TRUTH_ORIF_EXPR)
1986 {
1987 /* Turn if (a || b) into
1988
1989 if (a) goto yes;
1990 if (b) goto yes; else goto no;
1991 (yes:) */
1992
1993 if (true_label_p == NULL)
1994 true_label_p = &local_label;
1995
1996 t = shortcut_cond_r (TREE_OPERAND (pred, 0), true_label_p, NULL);
1997 append_to_statement_list (t, &expr);
1998
1999 t = shortcut_cond_r (TREE_OPERAND (pred, 1), true_label_p,
2000 false_label_p);
2001 append_to_statement_list (t, &expr);
2002 }
2003 else if (TREE_CODE (pred) == COND_EXPR)
2004 {
2005 /* As long as we're messing with gotos, turn if (a ? b : c) into
2006 if (a)
2007 if (b) goto yes; else goto no;
2008 else
2009 if (c) goto yes; else goto no; */
2010 expr = build3 (COND_EXPR, void_type_node, TREE_OPERAND (pred, 0),
2011 shortcut_cond_r (TREE_OPERAND (pred, 1), true_label_p,
2012 false_label_p),
2013 shortcut_cond_r (TREE_OPERAND (pred, 2), true_label_p,
2014 false_label_p));
2015 }
2016 else
2017 {
2018 expr = build3 (COND_EXPR, void_type_node, pred,
2019 build_and_jump (true_label_p),
2020 build_and_jump (false_label_p));
2021 }
2022
2023 if (local_label)
2024 {
2025 t = build1 (LABEL_EXPR, void_type_node, local_label);
2026 append_to_statement_list (t, &expr);
2027 }
2028
2029 return expr;
2030 }
2031
2032 static tree
2033 shortcut_cond_expr (tree expr)
2034 {
2035 tree pred = TREE_OPERAND (expr, 0);
2036 tree then_ = TREE_OPERAND (expr, 1);
2037 tree else_ = TREE_OPERAND (expr, 2);
2038 tree true_label, false_label, end_label, t;
2039 tree *true_label_p;
2040 tree *false_label_p;
2041 bool emit_end, emit_false, jump_over_else;
2042 bool then_se = then_ && TREE_SIDE_EFFECTS (then_);
2043 bool else_se = else_ && TREE_SIDE_EFFECTS (else_);
2044
2045 /* First do simple transformations. */
2046 if (!else_se)
2047 {
2048 /* If there is no 'else', turn (a && b) into if (a) if (b). */
2049 while (TREE_CODE (pred) == TRUTH_ANDIF_EXPR)
2050 {
2051 TREE_OPERAND (expr, 0) = TREE_OPERAND (pred, 1);
2052 then_ = shortcut_cond_expr (expr);
2053 then_se = then_ && TREE_SIDE_EFFECTS (then_);
2054 pred = TREE_OPERAND (pred, 0);
2055 expr = build3 (COND_EXPR, void_type_node, pred, then_, NULL_TREE);
2056 }
2057 }
2058 if (!then_se)
2059 {
2060 /* If there is no 'then', turn
2061 if (a || b); else d
2062 into
2063 if (a); else if (b); else d. */
2064 while (TREE_CODE (pred) == TRUTH_ORIF_EXPR)
2065 {
2066 TREE_OPERAND (expr, 0) = TREE_OPERAND (pred, 1);
2067 else_ = shortcut_cond_expr (expr);
2068 else_se = else_ && TREE_SIDE_EFFECTS (else_);
2069 pred = TREE_OPERAND (pred, 0);
2070 expr = build3 (COND_EXPR, void_type_node, pred, NULL_TREE, else_);
2071 }
2072 }
2073
2074 /* If we're done, great. */
2075 if (TREE_CODE (pred) != TRUTH_ANDIF_EXPR
2076 && TREE_CODE (pred) != TRUTH_ORIF_EXPR)
2077 return expr;
2078
2079 /* Otherwise we need to mess with gotos. Change
2080 if (a) c; else d;
2081 to
2082 if (a); else goto no;
2083 c; goto end;
2084 no: d; end:
2085 and recursively gimplify the condition. */
2086
2087 true_label = false_label = end_label = NULL_TREE;
2088
2089 /* If our arms just jump somewhere, hijack those labels so we don't
2090 generate jumps to jumps. */
2091
2092 if (then_
2093 && TREE_CODE (then_) == GOTO_EXPR
2094 && TREE_CODE (GOTO_DESTINATION (then_)) == LABEL_DECL)
2095 {
2096 true_label = GOTO_DESTINATION (then_);
2097 then_ = NULL;
2098 then_se = false;
2099 }
2100
2101 if (else_
2102 && TREE_CODE (else_) == GOTO_EXPR
2103 && TREE_CODE (GOTO_DESTINATION (else_)) == LABEL_DECL)
2104 {
2105 false_label = GOTO_DESTINATION (else_);
2106 else_ = NULL;
2107 else_se = false;
2108 }
2109
2110 /* If we aren't hijacking a label for the 'then' branch, it falls through. */
2111 if (true_label)
2112 true_label_p = &true_label;
2113 else
2114 true_label_p = NULL;
2115
2116 /* The 'else' branch also needs a label if it contains interesting code. */
2117 if (false_label || else_se)
2118 false_label_p = &false_label;
2119 else
2120 false_label_p = NULL;
2121
2122 /* If there was nothing else in our arms, just forward the label(s). */
2123 if (!then_se && !else_se)
2124 return shortcut_cond_r (pred, true_label_p, false_label_p);
2125
2126 /* If our last subexpression already has a terminal label, reuse it. */
2127 if (else_se)
2128 expr = expr_last (else_);
2129 else if (then_se)
2130 expr = expr_last (then_);
2131 else
2132 expr = NULL;
2133 if (expr && TREE_CODE (expr) == LABEL_EXPR)
2134 end_label = LABEL_EXPR_LABEL (expr);
2135
2136 /* If we don't care about jumping to the 'else' branch, jump to the end
2137 if the condition is false. */
2138 if (!false_label_p)
2139 false_label_p = &end_label;
2140
2141 /* We only want to emit these labels if we aren't hijacking them. */
2142 emit_end = (end_label == NULL_TREE);
2143 emit_false = (false_label == NULL_TREE);
2144
2145 /* We only emit the jump over the else clause if we have to--if the
2146 then clause may fall through. Otherwise we can wind up with a
2147 useless jump and a useless label at the end of gimplified code,
2148 which will cause us to think that this conditional as a whole
2149 falls through even if it doesn't. If we then inline a function
2150 which ends with such a condition, that can cause us to issue an
2151 inappropriate warning about control reaching the end of a
2152 non-void function. */
2153 jump_over_else = block_may_fallthru (then_);
2154
2155 pred = shortcut_cond_r (pred, true_label_p, false_label_p);
2156
2157 expr = NULL;
2158 append_to_statement_list (pred, &expr);
2159
2160 append_to_statement_list (then_, &expr);
2161 if (else_se)
2162 {
2163 if (jump_over_else)
2164 {
2165 t = build_and_jump (&end_label);
2166 append_to_statement_list (t, &expr);
2167 }
2168 if (emit_false)
2169 {
2170 t = build1 (LABEL_EXPR, void_type_node, false_label);
2171 append_to_statement_list (t, &expr);
2172 }
2173 append_to_statement_list (else_, &expr);
2174 }
2175 if (emit_end && end_label)
2176 {
2177 t = build1 (LABEL_EXPR, void_type_node, end_label);
2178 append_to_statement_list (t, &expr);
2179 }
2180
2181 return expr;
2182 }
2183
2184 /* EXPR is used in a boolean context; make sure it has BOOLEAN_TYPE. */
2185
2186 static tree
2187 gimple_boolify (tree expr)
2188 {
2189 tree type = TREE_TYPE (expr);
2190
2191 if (TREE_CODE (type) == BOOLEAN_TYPE)
2192 return expr;
2193
2194 switch (TREE_CODE (expr))
2195 {
2196 case TRUTH_AND_EXPR:
2197 case TRUTH_OR_EXPR:
2198 case TRUTH_XOR_EXPR:
2199 case TRUTH_ANDIF_EXPR:
2200 case TRUTH_ORIF_EXPR:
2201 /* Also boolify the arguments of truth exprs. */
2202 TREE_OPERAND (expr, 1) = gimple_boolify (TREE_OPERAND (expr, 1));
2203 /* FALLTHRU */
2204
2205 case TRUTH_NOT_EXPR:
2206 TREE_OPERAND (expr, 0) = gimple_boolify (TREE_OPERAND (expr, 0));
2207 /* FALLTHRU */
2208
2209 case EQ_EXPR: case NE_EXPR:
2210 case LE_EXPR: case GE_EXPR: case LT_EXPR: case GT_EXPR:
2211 /* These expressions always produce boolean results. */
2212 TREE_TYPE (expr) = boolean_type_node;
2213 return expr;
2214
2215 default:
2216 /* Other expressions that get here must have boolean values, but
2217 might need to be converted to the appropriate mode. */
2218 return convert (boolean_type_node, expr);
2219 }
2220 }
2221
2222 /* Convert the conditional expression pointed to by EXPR_P '(p) ? a : b;'
2223 into
2224
2225 if (p) if (p)
2226 t1 = a; a;
2227 else or else
2228 t1 = b; b;
2229 t1;
2230
2231 The second form is used when *EXPR_P is of type void.
2232
2233 TARGET is the tree for T1 above.
2234
2235 PRE_P points to the list where side effects that must happen before
2236 *EXPR_P should be stored.
2237
2238 POST_P points to the list where side effects that must happen after
2239 *EXPR_P should be stored. */
2240
2241 static enum gimplify_status
2242 gimplify_cond_expr (tree *expr_p, tree *pre_p, tree *post_p, tree target,
2243 fallback_t fallback)
2244 {
2245 tree expr = *expr_p;
2246 tree tmp, tmp2, type;
2247 enum gimplify_status ret;
2248
2249 type = TREE_TYPE (expr);
2250
2251 /* If this COND_EXPR has a value, copy the values into a temporary within
2252 the arms. */
2253 if (! VOID_TYPE_P (type))
2254 {
2255 tree result;
2256
2257 if (target)
2258 {
2259 ret = gimplify_expr (&target, pre_p, post_p,
2260 is_gimple_min_lval, fb_lvalue);
2261 if (ret != GS_ERROR)
2262 ret = GS_OK;
2263 result = tmp = target;
2264 tmp2 = unshare_expr (target);
2265 }
2266 else if ((fallback & fb_lvalue) == 0)
2267 {
2268 result = tmp2 = tmp = create_tmp_var (TREE_TYPE (expr), "iftmp");
2269 ret = GS_ALL_DONE;
2270 }
2271 else
2272 {
2273 tree type = build_pointer_type (TREE_TYPE (expr));
2274
2275 if (TREE_TYPE (TREE_OPERAND (expr, 1)) != void_type_node)
2276 TREE_OPERAND (expr, 1) =
2277 build_fold_addr_expr (TREE_OPERAND (expr, 1));
2278
2279 if (TREE_TYPE (TREE_OPERAND (expr, 2)) != void_type_node)
2280 TREE_OPERAND (expr, 2) =
2281 build_fold_addr_expr (TREE_OPERAND (expr, 2));
2282
2283 tmp2 = tmp = create_tmp_var (type, "iftmp");
2284
2285 expr = build3 (COND_EXPR, void_type_node, TREE_OPERAND (expr, 0),
2286 TREE_OPERAND (expr, 1), TREE_OPERAND (expr, 2));
2287
2288 result = build_fold_indirect_ref (tmp);
2289 ret = GS_ALL_DONE;
2290 }
2291
2292 /* Build the then clause, 't1 = a;'. But don't build an assignment
2293 if this branch is void; in C++ it can be, if it's a throw. */
2294 if (TREE_TYPE (TREE_OPERAND (expr, 1)) != void_type_node)
2295 TREE_OPERAND (expr, 1)
2296 = build2 (MODIFY_EXPR, void_type_node, tmp, TREE_OPERAND (expr, 1));
2297
2298 /* Build the else clause, 't1 = b;'. */
2299 if (TREE_TYPE (TREE_OPERAND (expr, 2)) != void_type_node)
2300 TREE_OPERAND (expr, 2)
2301 = build2 (MODIFY_EXPR, void_type_node, tmp2, TREE_OPERAND (expr, 2));
2302
2303 TREE_TYPE (expr) = void_type_node;
2304 recalculate_side_effects (expr);
2305
2306 /* Move the COND_EXPR to the prequeue. */
2307 gimplify_and_add (expr, pre_p);
2308
2309 *expr_p = result;
2310 return ret;
2311 }
2312
2313 /* Make sure the condition has BOOLEAN_TYPE. */
2314 TREE_OPERAND (expr, 0) = gimple_boolify (TREE_OPERAND (expr, 0));
2315
2316 /* Break apart && and || conditions. */
2317 if (TREE_CODE (TREE_OPERAND (expr, 0)) == TRUTH_ANDIF_EXPR
2318 || TREE_CODE (TREE_OPERAND (expr, 0)) == TRUTH_ORIF_EXPR)
2319 {
2320 expr = shortcut_cond_expr (expr);
2321
2322 if (expr != *expr_p)
2323 {
2324 *expr_p = expr;
2325
2326 /* We can't rely on gimplify_expr to re-gimplify the expanded
2327 form properly, as cleanups might cause the target labels to be
2328 wrapped in a TRY_FINALLY_EXPR. To prevent that, we need to
2329 set up a conditional context. */
2330 gimple_push_condition ();
2331 gimplify_stmt (expr_p);
2332 gimple_pop_condition (pre_p);
2333
2334 return GS_ALL_DONE;
2335 }
2336 }
2337
2338 /* Now do the normal gimplification. */
2339 ret = gimplify_expr (&TREE_OPERAND (expr, 0), pre_p, NULL,
2340 is_gimple_condexpr, fb_rvalue);
2341
2342 gimple_push_condition ();
2343
2344 gimplify_to_stmt_list (&TREE_OPERAND (expr, 1));
2345 gimplify_to_stmt_list (&TREE_OPERAND (expr, 2));
2346 recalculate_side_effects (expr);
2347
2348 gimple_pop_condition (pre_p);
2349
2350 if (ret == GS_ERROR)
2351 ;
2352 else if (TREE_SIDE_EFFECTS (TREE_OPERAND (expr, 1)))
2353 ret = GS_ALL_DONE;
2354 else if (TREE_SIDE_EFFECTS (TREE_OPERAND (expr, 2)))
2355 /* Rewrite "if (a); else b" to "if (!a) b" */
2356 {
2357 TREE_OPERAND (expr, 0) = invert_truthvalue (TREE_OPERAND (expr, 0));
2358 ret = gimplify_expr (&TREE_OPERAND (expr, 0), pre_p, NULL,
2359 is_gimple_condexpr, fb_rvalue);
2360
2361 tmp = TREE_OPERAND (expr, 1);
2362 TREE_OPERAND (expr, 1) = TREE_OPERAND (expr, 2);
2363 TREE_OPERAND (expr, 2) = tmp;
2364 }
2365 else
2366 /* Both arms are empty; replace the COND_EXPR with its predicate. */
2367 expr = TREE_OPERAND (expr, 0);
2368
2369 *expr_p = expr;
2370 return ret;
2371 }
2372
2373 /* A subroutine of gimplify_modify_expr. Replace a MODIFY_EXPR with
2374 a call to __builtin_memcpy. */
2375
2376 static enum gimplify_status
2377 gimplify_modify_expr_to_memcpy (tree *expr_p, tree size, bool want_value)
2378 {
2379 tree args, t, to, to_ptr, from;
2380
2381 to = TREE_OPERAND (*expr_p, 0);
2382 from = TREE_OPERAND (*expr_p, 1);
2383
2384 args = tree_cons (NULL, size, NULL);
2385
2386 t = build_fold_addr_expr (from);
2387 args = tree_cons (NULL, t, args);
2388
2389 to_ptr = build_fold_addr_expr (to);
2390 args = tree_cons (NULL, to_ptr, args);
2391 t = implicit_built_in_decls[BUILT_IN_MEMCPY];
2392 t = build_function_call_expr (t, args);
2393
2394 if (want_value)
2395 {
2396 t = build1 (NOP_EXPR, TREE_TYPE (to_ptr), t);
2397 t = build1 (INDIRECT_REF, TREE_TYPE (to), t);
2398 }
2399
2400 *expr_p = t;
2401 return GS_OK;
2402 }
2403
2404 /* A subroutine of gimplify_modify_expr. Replace a MODIFY_EXPR with
2405 a call to __builtin_memset. In this case we know that the RHS is
2406 a CONSTRUCTOR with an empty element list. */
2407
2408 static enum gimplify_status
2409 gimplify_modify_expr_to_memset (tree *expr_p, tree size, bool want_value)
2410 {
2411 tree args, t, to, to_ptr;
2412
2413 to = TREE_OPERAND (*expr_p, 0);
2414
2415 args = tree_cons (NULL, size, NULL);
2416
2417 args = tree_cons (NULL, integer_zero_node, args);
2418
2419 to_ptr = build_fold_addr_expr (to);
2420 args = tree_cons (NULL, to_ptr, args);
2421 t = implicit_built_in_decls[BUILT_IN_MEMSET];
2422 t = build_function_call_expr (t, args);
2423
2424 if (want_value)
2425 {
2426 t = build1 (NOP_EXPR, TREE_TYPE (to_ptr), t);
2427 t = build1 (INDIRECT_REF, TREE_TYPE (to), t);
2428 }
2429
2430 *expr_p = t;
2431 return GS_OK;
2432 }
2433
2434 /* A subroutine of gimplify_init_ctor_preeval. Called via walk_tree,
2435 determine, cautiously, if a CONSTRUCTOR overlaps the lhs of an
2436 assignment. Returns non-null if we detect a potential overlap. */
2437
2438 struct gimplify_init_ctor_preeval_data
2439 {
2440 /* The base decl of the lhs object. May be NULL, in which case we
2441 have to assume the lhs is indirect. */
2442 tree lhs_base_decl;
2443
2444 /* The alias set of the lhs object. */
2445 int lhs_alias_set;
2446 };
2447
2448 static tree
2449 gimplify_init_ctor_preeval_1 (tree *tp, int *walk_subtrees, void *xdata)
2450 {
2451 struct gimplify_init_ctor_preeval_data *data
2452 = (struct gimplify_init_ctor_preeval_data *) xdata;
2453 tree t = *tp;
2454
2455 /* If we find the base object, obviously we have overlap. */
2456 if (data->lhs_base_decl == t)
2457 return t;
2458
2459 /* If the constructor component is indirect, determine if we have a
2460 potential overlap with the lhs. The only bits of information we
2461 have to go on at this point are addressability and alias sets. */
2462 if (TREE_CODE (t) == INDIRECT_REF
2463 && (!data->lhs_base_decl || TREE_ADDRESSABLE (data->lhs_base_decl))
2464 && alias_sets_conflict_p (data->lhs_alias_set, get_alias_set (t)))
2465 return t;
2466
2467 if (IS_TYPE_OR_DECL_P (t))
2468 *walk_subtrees = 0;
2469 return NULL;
2470 }
2471
2472 /* A subroutine of gimplify_init_constructor. Pre-evaluate *EXPR_P,
2473 force values that overlap with the lhs (as described by *DATA)
2474 into temporaries. */
2475
2476 static void
2477 gimplify_init_ctor_preeval (tree *expr_p, tree *pre_p, tree *post_p,
2478 struct gimplify_init_ctor_preeval_data *data)
2479 {
2480 enum gimplify_status one;
2481
2482 /* If the value is invariant, then there's nothing to pre-evaluate.
2483 But ensure it doesn't have any side-effects since a SAVE_EXPR is
2484 invariant but has side effects and might contain a reference to
2485 the object we're initializing. */
2486 if (TREE_INVARIANT (*expr_p) && !TREE_SIDE_EFFECTS (*expr_p))
2487 return;
2488
2489 /* If the type has non-trivial constructors, we can't pre-evaluate. */
2490 if (TREE_ADDRESSABLE (TREE_TYPE (*expr_p)))
2491 return;
2492
2493 /* Recurse for nested constructors. */
2494 if (TREE_CODE (*expr_p) == CONSTRUCTOR)
2495 {
2496 unsigned HOST_WIDE_INT ix;
2497 constructor_elt *ce;
2498 VEC(constructor_elt,gc) *v = CONSTRUCTOR_ELTS (*expr_p);
2499
2500 for (ix = 0; VEC_iterate (constructor_elt, v, ix, ce); ix++)
2501 gimplify_init_ctor_preeval (&ce->value, pre_p, post_p, data);
2502 return;
2503 }
2504
2505 /* We can't preevaluate if the type contains a placeholder. */
2506 if (type_contains_placeholder_p (TREE_TYPE (*expr_p)))
2507 return;
2508
2509 /* Gimplify the constructor element to something appropriate for the rhs
2510 of a MODIFY_EXPR. Given that we know the lhs is an aggregate, we know
2511 the gimplifier will consider this a store to memory. Doing this
2512 gimplification now means that we won't have to deal with complicated
2513 language-specific trees, nor trees like SAVE_EXPR that can induce
2514 exponential search behavior. */
2515 one = gimplify_expr (expr_p, pre_p, post_p, is_gimple_mem_rhs, fb_rvalue);
2516 if (one == GS_ERROR)
2517 {
2518 *expr_p = NULL;
2519 return;
2520 }
2521
2522 /* If we gimplified to a bare decl, we can be sure that it doesn't overlap
2523 with the lhs, since "a = { .x=a }" doesn't make sense. This will
2524 always be true for all scalars, since is_gimple_mem_rhs insists on a
2525 temporary variable for them. */
2526 if (DECL_P (*expr_p))
2527 return;
2528
2529 /* If this is of variable size, we have no choice but to assume it doesn't
2530 overlap since we can't make a temporary for it. */
2531 if (!TREE_CONSTANT (TYPE_SIZE (TREE_TYPE (*expr_p))))
2532 return;
2533
2534 /* Otherwise, we must search for overlap ... */
2535 if (!walk_tree (expr_p, gimplify_init_ctor_preeval_1, data, NULL))
2536 return;
2537
2538 /* ... and if found, force the value into a temporary. */
2539 *expr_p = get_formal_tmp_var (*expr_p, pre_p);
2540 }
2541
2542 /* A subroutine of gimplify_init_ctor_eval. Create a loop for
2543 a RANGE_EXPR in a CONSTRUCTOR for an array.
2544
2545 var = lower;
2546 loop_entry:
2547 object[var] = value;
2548 if (var == upper)
2549 goto loop_exit;
2550 var = var + 1;
2551 goto loop_entry;
2552 loop_exit:
2553
2554 We increment var _after_ the loop exit check because we might otherwise
2555 fail if upper == TYPE_MAX_VALUE (type for upper).
2556
2557 Note that we never have to deal with SAVE_EXPRs here, because this has
2558 already been taken care of for us, in gimplify_init_ctor_preeval(). */
2559
2560 static void gimplify_init_ctor_eval (tree, VEC(constructor_elt,gc) *,
2561 tree *, bool);
2562
2563 static void
2564 gimplify_init_ctor_eval_range (tree object, tree lower, tree upper,
2565 tree value, tree array_elt_type,
2566 tree *pre_p, bool cleared)
2567 {
2568 tree loop_entry_label, loop_exit_label;
2569 tree var, var_type, cref;
2570
2571 loop_entry_label = create_artificial_label ();
2572 loop_exit_label = create_artificial_label ();
2573
2574 /* Create and initialize the index variable. */
2575 var_type = TREE_TYPE (upper);
2576 var = create_tmp_var (var_type, NULL);
2577 append_to_statement_list (build2 (MODIFY_EXPR, var_type, var, lower), pre_p);
2578
2579 /* Add the loop entry label. */
2580 append_to_statement_list (build1 (LABEL_EXPR,
2581 void_type_node,
2582 loop_entry_label),
2583 pre_p);
2584
2585 /* Build the reference. */
2586 cref = build4 (ARRAY_REF, array_elt_type, unshare_expr (object),
2587 var, NULL_TREE, NULL_TREE);
2588
2589 /* If we are a constructor, just call gimplify_init_ctor_eval to do
2590 the store. Otherwise just assign value to the reference. */
2591
2592 if (TREE_CODE (value) == CONSTRUCTOR)
2593 /* NB we might have to call ourself recursively through
2594 gimplify_init_ctor_eval if the value is a constructor. */
2595 gimplify_init_ctor_eval (cref, CONSTRUCTOR_ELTS (value),
2596 pre_p, cleared);
2597 else
2598 append_to_statement_list (build2 (MODIFY_EXPR, TREE_TYPE (cref),
2599 cref, value),
2600 pre_p);
2601
2602 /* We exit the loop when the index var is equal to the upper bound. */
2603 gimplify_and_add (build3 (COND_EXPR, void_type_node,
2604 build2 (EQ_EXPR, boolean_type_node,
2605 var, upper),
2606 build1 (GOTO_EXPR,
2607 void_type_node,
2608 loop_exit_label),
2609 NULL_TREE),
2610 pre_p);
2611
2612 /* Otherwise, increment the index var... */
2613 append_to_statement_list (build2 (MODIFY_EXPR, var_type, var,
2614 build2 (PLUS_EXPR, var_type, var,
2615 fold_convert (var_type,
2616 integer_one_node))),
2617 pre_p);
2618
2619 /* ...and jump back to the loop entry. */
2620 append_to_statement_list (build1 (GOTO_EXPR,
2621 void_type_node,
2622 loop_entry_label),
2623 pre_p);
2624
2625 /* Add the loop exit label. */
2626 append_to_statement_list (build1 (LABEL_EXPR,
2627 void_type_node,
2628 loop_exit_label),
2629 pre_p);
2630 }
2631
2632 /* Return true if FDECL is accessing a field that is zero sized. */
2633
2634 static bool
2635 zero_sized_field_decl (tree fdecl)
2636 {
2637 if (TREE_CODE (fdecl) == FIELD_DECL && DECL_SIZE (fdecl)
2638 && integer_zerop (DECL_SIZE (fdecl)))
2639 return true;
2640 return false;
2641 }
2642
2643 /* Return true if TYPE is zero sized. */
2644
2645 static bool
2646 zero_sized_type (tree type)
2647 {
2648 if (AGGREGATE_TYPE_P (type) && TYPE_SIZE (type)
2649 && integer_zerop (TYPE_SIZE (type)))
2650 return true;
2651 return false;
2652 }
2653
2654 /* A subroutine of gimplify_init_constructor. Generate individual
2655 MODIFY_EXPRs for a CONSTRUCTOR. OBJECT is the LHS against which the
2656 assignments should happen. ELTS is the CONSTRUCTOR_ELTS of the
2657 CONSTRUCTOR. CLEARED is true if the entire LHS object has been
2658 zeroed first. */
2659
2660 static void
2661 gimplify_init_ctor_eval (tree object, VEC(constructor_elt,gc) *elts,
2662 tree *pre_p, bool cleared)
2663 {
2664 tree array_elt_type = NULL;
2665 unsigned HOST_WIDE_INT ix;
2666 tree purpose, value;
2667
2668 if (TREE_CODE (TREE_TYPE (object)) == ARRAY_TYPE)
2669 array_elt_type = TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (object)));
2670
2671 FOR_EACH_CONSTRUCTOR_ELT (elts, ix, purpose, value)
2672 {
2673 tree cref, init;
2674
2675 /* NULL values are created above for gimplification errors. */
2676 if (value == NULL)
2677 continue;
2678
2679 if (cleared && initializer_zerop (value))
2680 continue;
2681
2682 /* ??? Here's to hoping the front end fills in all of the indices,
2683 so we don't have to figure out what's missing ourselves. */
2684 gcc_assert (purpose);
2685
2686 /* Skip zero-sized fields, unless value has side-effects. This can
2687 happen with calls to functions returning a zero-sized type, which
2688 we shouldn't discard. As a number of downstream passes don't
2689 expect sets of zero-sized fields, we rely on the gimplification of
2690 the MODIFY_EXPR we make below to drop the assignment statement. */
2691 if (! TREE_SIDE_EFFECTS (value) && zero_sized_field_decl (purpose))
2692 continue;
2693
2694 /* If we have a RANGE_EXPR, we have to build a loop to assign the
2695 whole range. */
2696 if (TREE_CODE (purpose) == RANGE_EXPR)
2697 {
2698 tree lower = TREE_OPERAND (purpose, 0);
2699 tree upper = TREE_OPERAND (purpose, 1);
2700
2701 /* If the lower bound is equal to upper, just treat it as if
2702 upper was the index. */
2703 if (simple_cst_equal (lower, upper))
2704 purpose = upper;
2705 else
2706 {
2707 gimplify_init_ctor_eval_range (object, lower, upper, value,
2708 array_elt_type, pre_p, cleared);
2709 continue;
2710 }
2711 }
2712
2713 if (array_elt_type)
2714 {
2715 cref = build4 (ARRAY_REF, array_elt_type, unshare_expr (object),
2716 purpose, NULL_TREE, NULL_TREE);
2717 }
2718 else
2719 {
2720 gcc_assert (TREE_CODE (purpose) == FIELD_DECL);
2721 cref = build3 (COMPONENT_REF, TREE_TYPE (purpose),
2722 unshare_expr (object), purpose, NULL_TREE);
2723 }
2724
2725 if (TREE_CODE (value) == CONSTRUCTOR
2726 && TREE_CODE (TREE_TYPE (value)) != VECTOR_TYPE)
2727 gimplify_init_ctor_eval (cref, CONSTRUCTOR_ELTS (value),
2728 pre_p, cleared);
2729 else
2730 {
2731 init = build2 (MODIFY_EXPR, TREE_TYPE (cref), cref, value);
2732 gimplify_and_add (init, pre_p);
2733 }
2734 }
2735 }
2736
2737 /* A subroutine of gimplify_modify_expr. Break out elements of a
2738 CONSTRUCTOR used as an initializer into separate MODIFY_EXPRs.
2739
2740 Note that we still need to clear any elements that don't have explicit
2741 initializers, so if not all elements are initialized we keep the
2742 original MODIFY_EXPR, we just remove all of the constructor elements. */
2743
2744 static enum gimplify_status
2745 gimplify_init_constructor (tree *expr_p, tree *pre_p,
2746 tree *post_p, bool want_value)
2747 {
2748 tree object;
2749 tree ctor = TREE_OPERAND (*expr_p, 1);
2750 tree type = TREE_TYPE (ctor);
2751 enum gimplify_status ret;
2752 VEC(constructor_elt,gc) *elts;
2753
2754 if (TREE_CODE (ctor) != CONSTRUCTOR)
2755 return GS_UNHANDLED;
2756
2757 ret = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p, post_p,
2758 is_gimple_lvalue, fb_lvalue);
2759 if (ret == GS_ERROR)
2760 return ret;
2761 object = TREE_OPERAND (*expr_p, 0);
2762
2763 elts = CONSTRUCTOR_ELTS (ctor);
2764
2765 ret = GS_ALL_DONE;
2766 switch (TREE_CODE (type))
2767 {
2768 case RECORD_TYPE:
2769 case UNION_TYPE:
2770 case QUAL_UNION_TYPE:
2771 case ARRAY_TYPE:
2772 {
2773 struct gimplify_init_ctor_preeval_data preeval_data;
2774 HOST_WIDE_INT num_type_elements, num_ctor_elements;
2775 HOST_WIDE_INT num_nonzero_elements, num_nonconstant_elements;
2776 bool cleared;
2777
2778 /* Aggregate types must lower constructors to initialization of
2779 individual elements. The exception is that a CONSTRUCTOR node
2780 with no elements indicates zero-initialization of the whole. */
2781 if (VEC_empty (constructor_elt, elts))
2782 break;
2783
2784 categorize_ctor_elements (ctor, &num_nonzero_elements,
2785 &num_nonconstant_elements,
2786 &num_ctor_elements, &cleared);
2787
2788 /* If a const aggregate variable is being initialized, then it
2789 should never be a lose to promote the variable to be static. */
2790 if (num_nonconstant_elements == 0
2791 && num_nonzero_elements > 1
2792 && TREE_READONLY (object)
2793 && TREE_CODE (object) == VAR_DECL)
2794 {
2795 DECL_INITIAL (object) = ctor;
2796 TREE_STATIC (object) = 1;
2797 if (!DECL_NAME (object))
2798 DECL_NAME (object) = create_tmp_var_name ("C");
2799 walk_tree (&DECL_INITIAL (object), force_labels_r, NULL, NULL);
2800
2801 /* ??? C++ doesn't automatically append a .<number> to the
2802 assembler name, and even when it does, it looks a FE private
2803 data structures to figure out what that number should be,
2804 which are not set for this variable. I suppose this is
2805 important for local statics for inline functions, which aren't
2806 "local" in the object file sense. So in order to get a unique
2807 TU-local symbol, we must invoke the lhd version now. */
2808 lhd_set_decl_assembler_name (object);
2809
2810 *expr_p = NULL_TREE;
2811 break;
2812 }
2813
2814 /* If there are "lots" of initialized elements, even discounting
2815 those that are not address constants (and thus *must* be
2816 computed at runtime), then partition the constructor into
2817 constant and non-constant parts. Block copy the constant
2818 parts in, then generate code for the non-constant parts. */
2819 /* TODO. There's code in cp/typeck.c to do this. */
2820
2821 num_type_elements = count_type_elements (type, true);
2822
2823 /* If count_type_elements could not determine number of type elements
2824 for a constant-sized object, assume clearing is needed.
2825 Don't do this for variable-sized objects, as store_constructor
2826 will ignore the clearing of variable-sized objects. */
2827 if (num_type_elements < 0 && int_size_in_bytes (type) >= 0)
2828 cleared = true;
2829 /* If there are "lots" of zeros, then block clear the object first. */
2830 else if (num_type_elements - num_nonzero_elements > CLEAR_RATIO
2831 && num_nonzero_elements < num_type_elements/4)
2832 cleared = true;
2833 /* ??? This bit ought not be needed. For any element not present
2834 in the initializer, we should simply set them to zero. Except
2835 we'd need to *find* the elements that are not present, and that
2836 requires trickery to avoid quadratic compile-time behavior in
2837 large cases or excessive memory use in small cases. */
2838 else if (num_ctor_elements < num_type_elements)
2839 cleared = true;
2840
2841 /* If there are "lots" of initialized elements, and all of them
2842 are valid address constants, then the entire initializer can
2843 be dropped to memory, and then memcpy'd out. Don't do this
2844 for sparse arrays, though, as it's more efficient to follow
2845 the standard CONSTRUCTOR behavior of memset followed by
2846 individual element initialization. */
2847 if (num_nonconstant_elements == 0 && !cleared)
2848 {
2849 HOST_WIDE_INT size = int_size_in_bytes (type);
2850 unsigned int align;
2851
2852 /* ??? We can still get unbounded array types, at least
2853 from the C++ front end. This seems wrong, but attempt
2854 to work around it for now. */
2855 if (size < 0)
2856 {
2857 size = int_size_in_bytes (TREE_TYPE (object));
2858 if (size >= 0)
2859 TREE_TYPE (ctor) = type = TREE_TYPE (object);
2860 }
2861
2862 /* Find the maximum alignment we can assume for the object. */
2863 /* ??? Make use of DECL_OFFSET_ALIGN. */
2864 if (DECL_P (object))
2865 align = DECL_ALIGN (object);
2866 else
2867 align = TYPE_ALIGN (type);
2868
2869 if (size > 0 && !can_move_by_pieces (size, align))
2870 {
2871 tree new = create_tmp_var_raw (type, "C");
2872
2873 gimple_add_tmp_var (new);
2874 TREE_STATIC (new) = 1;
2875 TREE_READONLY (new) = 1;
2876 DECL_INITIAL (new) = ctor;
2877 if (align > DECL_ALIGN (new))
2878 {
2879 DECL_ALIGN (new) = align;
2880 DECL_USER_ALIGN (new) = 1;
2881 }
2882 walk_tree (&DECL_INITIAL (new), force_labels_r, NULL, NULL);
2883
2884 TREE_OPERAND (*expr_p, 1) = new;
2885
2886 /* This is no longer an assignment of a CONSTRUCTOR, but
2887 we still may have processing to do on the LHS. So
2888 pretend we didn't do anything here to let that happen. */
2889 return GS_UNHANDLED;
2890 }
2891 }
2892
2893 if (cleared)
2894 {
2895 /* Zap the CONSTRUCTOR element list, which simplifies this case.
2896 Note that we still have to gimplify, in order to handle the
2897 case of variable sized types. Avoid shared tree structures. */
2898 CONSTRUCTOR_ELTS (ctor) = NULL;
2899 object = unshare_expr (object);
2900 gimplify_stmt (expr_p);
2901 append_to_statement_list (*expr_p, pre_p);
2902 }
2903
2904 /* If we have not block cleared the object, or if there are nonzero
2905 elements in the constructor, add assignments to the individual
2906 scalar fields of the object. */
2907 if (!cleared || num_nonzero_elements > 0)
2908 {
2909 preeval_data.lhs_base_decl = get_base_address (object);
2910 if (!DECL_P (preeval_data.lhs_base_decl))
2911 preeval_data.lhs_base_decl = NULL;
2912 preeval_data.lhs_alias_set = get_alias_set (object);
2913
2914 gimplify_init_ctor_preeval (&TREE_OPERAND (*expr_p, 1),
2915 pre_p, post_p, &preeval_data);
2916 gimplify_init_ctor_eval (object, elts, pre_p, cleared);
2917 }
2918
2919 *expr_p = NULL_TREE;
2920 }
2921 break;
2922
2923 case COMPLEX_TYPE:
2924 {
2925 tree r, i;
2926
2927 /* Extract the real and imaginary parts out of the ctor. */
2928 gcc_assert (VEC_length (constructor_elt, elts) == 2);
2929 r = VEC_index (constructor_elt, elts, 0)->value;
2930 i = VEC_index (constructor_elt, elts, 1)->value;
2931 if (r == NULL || i == NULL)
2932 {
2933 tree zero = convert (TREE_TYPE (type), integer_zero_node);
2934 if (r == NULL)
2935 r = zero;
2936 if (i == NULL)
2937 i = zero;
2938 }
2939
2940 /* Complex types have either COMPLEX_CST or COMPLEX_EXPR to
2941 represent creation of a complex value. */
2942 if (TREE_CONSTANT (r) && TREE_CONSTANT (i))
2943 {
2944 ctor = build_complex (type, r, i);
2945 TREE_OPERAND (*expr_p, 1) = ctor;
2946 }
2947 else
2948 {
2949 ctor = build2 (COMPLEX_EXPR, type, r, i);
2950 TREE_OPERAND (*expr_p, 1) = ctor;
2951 ret = gimplify_expr (&TREE_OPERAND (*expr_p, 1), pre_p, post_p,
2952 rhs_predicate_for (TREE_OPERAND (*expr_p, 0)),
2953 fb_rvalue);
2954 }
2955 }
2956 break;
2957
2958 case VECTOR_TYPE:
2959 {
2960 unsigned HOST_WIDE_INT ix;
2961 constructor_elt *ce;
2962
2963 /* Go ahead and simplify constant constructors to VECTOR_CST. */
2964 if (TREE_CONSTANT (ctor))
2965 {
2966 bool constant_p = true;
2967 tree value;
2968
2969 /* Even when ctor is constant, it might contain non-*_CST
2970 elements (e.g. { 1.0/0.0 - 1.0/0.0, 0.0 }) and those don't
2971 belong into VECTOR_CST nodes. */
2972 FOR_EACH_CONSTRUCTOR_VALUE (elts, ix, value)
2973 if (!CONSTANT_CLASS_P (value))
2974 {
2975 constant_p = false;
2976 break;
2977 }
2978
2979 if (constant_p)
2980 {
2981 TREE_OPERAND (*expr_p, 1) = build_vector_from_ctor (type, elts);
2982 break;
2983 }
2984 }
2985
2986 /* Vector types use CONSTRUCTOR all the way through gimple
2987 compilation as a general initializer. */
2988 for (ix = 0; VEC_iterate (constructor_elt, elts, ix, ce); ix++)
2989 {
2990 enum gimplify_status tret;
2991 tret = gimplify_expr (&ce->value, pre_p, post_p,
2992 is_gimple_val, fb_rvalue);
2993 if (tret == GS_ERROR)
2994 ret = GS_ERROR;
2995 }
2996 }
2997 break;
2998
2999 default:
3000 /* So how did we get a CONSTRUCTOR for a scalar type? */
3001 gcc_unreachable ();
3002 }
3003
3004 if (ret == GS_ERROR)
3005 return GS_ERROR;
3006 else if (want_value)
3007 {
3008 append_to_statement_list (*expr_p, pre_p);
3009 *expr_p = object;
3010 return GS_OK;
3011 }
3012 else
3013 return GS_ALL_DONE;
3014 }
3015
3016 /* Given a pointer value OP0, return a simplified version of an
3017 indirection through OP0, or NULL_TREE if no simplification is
3018 possible. This may only be applied to a rhs of an expression.
3019 Note that the resulting type may be different from the type pointed
3020 to in the sense that it is still compatible from the langhooks
3021 point of view. */
3022
3023 static tree
3024 fold_indirect_ref_rhs (tree t)
3025 {
3026 tree type = TREE_TYPE (TREE_TYPE (t));
3027 tree sub = t;
3028 tree subtype;
3029
3030 STRIP_NOPS (sub);
3031 subtype = TREE_TYPE (sub);
3032 if (!POINTER_TYPE_P (subtype))
3033 return NULL_TREE;
3034
3035 if (TREE_CODE (sub) == ADDR_EXPR)
3036 {
3037 tree op = TREE_OPERAND (sub, 0);
3038 tree optype = TREE_TYPE (op);
3039 /* *&p => p */
3040 if (lang_hooks.types_compatible_p (type, optype))
3041 return op;
3042 /* *(foo *)&fooarray => fooarray[0] */
3043 else if (TREE_CODE (optype) == ARRAY_TYPE
3044 && lang_hooks.types_compatible_p (type, TREE_TYPE (optype)))
3045 {
3046 tree type_domain = TYPE_DOMAIN (optype);
3047 tree min_val = size_zero_node;
3048 if (type_domain && TYPE_MIN_VALUE (type_domain))
3049 min_val = TYPE_MIN_VALUE (type_domain);
3050 return build4 (ARRAY_REF, type, op, min_val, NULL_TREE, NULL_TREE);
3051 }
3052 }
3053
3054 /* *(foo *)fooarrptr => (*fooarrptr)[0] */
3055 if (TREE_CODE (TREE_TYPE (subtype)) == ARRAY_TYPE
3056 && lang_hooks.types_compatible_p (type, TREE_TYPE (TREE_TYPE (subtype))))
3057 {
3058 tree type_domain;
3059 tree min_val = size_zero_node;
3060 tree osub = sub;
3061 sub = fold_indirect_ref_rhs (sub);
3062 if (! sub)
3063 sub = build1 (INDIRECT_REF, TREE_TYPE (subtype), osub);
3064 type_domain = TYPE_DOMAIN (TREE_TYPE (sub));
3065 if (type_domain && TYPE_MIN_VALUE (type_domain))
3066 min_val = TYPE_MIN_VALUE (type_domain);
3067 return build4 (ARRAY_REF, type, sub, min_val, NULL_TREE, NULL_TREE);
3068 }
3069
3070 return NULL_TREE;
3071 }
3072
3073 /* Subroutine of gimplify_modify_expr to do simplifications of MODIFY_EXPRs
3074 based on the code of the RHS. We loop for as long as something changes. */
3075
3076 static enum gimplify_status
3077 gimplify_modify_expr_rhs (tree *expr_p, tree *from_p, tree *to_p, tree *pre_p,
3078 tree *post_p, bool want_value)
3079 {
3080 enum gimplify_status ret = GS_OK;
3081
3082 while (ret != GS_UNHANDLED)
3083 switch (TREE_CODE (*from_p))
3084 {
3085 case INDIRECT_REF:
3086 {
3087 /* If we have code like
3088
3089 *(const A*)(A*)&x
3090
3091 where the type of "x" is a (possibly cv-qualified variant
3092 of "A"), treat the entire expression as identical to "x".
3093 This kind of code arises in C++ when an object is bound
3094 to a const reference, and if "x" is a TARGET_EXPR we want
3095 to take advantage of the optimization below. */
3096 tree t = fold_indirect_ref_rhs (TREE_OPERAND (*from_p, 0));
3097 if (t)
3098 {
3099 *from_p = t;
3100 ret = GS_OK;
3101 }
3102 else
3103 ret = GS_UNHANDLED;
3104 break;
3105 }
3106
3107 case TARGET_EXPR:
3108 {
3109 /* If we are initializing something from a TARGET_EXPR, strip the
3110 TARGET_EXPR and initialize it directly, if possible. This can't
3111 be done if the initializer is void, since that implies that the
3112 temporary is set in some non-trivial way.
3113
3114 ??? What about code that pulls out the temp and uses it
3115 elsewhere? I think that such code never uses the TARGET_EXPR as
3116 an initializer. If I'm wrong, we'll die because the temp won't
3117 have any RTL. In that case, I guess we'll need to replace
3118 references somehow. */
3119 tree init = TARGET_EXPR_INITIAL (*from_p);
3120
3121 if (!VOID_TYPE_P (TREE_TYPE (init)))
3122 {
3123 *from_p = init;
3124 ret = GS_OK;
3125 }
3126 else
3127 ret = GS_UNHANDLED;
3128 }
3129 break;
3130
3131 case COMPOUND_EXPR:
3132 /* Remove any COMPOUND_EXPR in the RHS so the following cases will be
3133 caught. */
3134 gimplify_compound_expr (from_p, pre_p, true);
3135 ret = GS_OK;
3136 break;
3137
3138 case CONSTRUCTOR:
3139 /* If we're initializing from a CONSTRUCTOR, break this into
3140 individual MODIFY_EXPRs. */
3141 return gimplify_init_constructor (expr_p, pre_p, post_p, want_value);
3142
3143 case COND_EXPR:
3144 /* If we're assigning to a non-register type, push the assignment
3145 down into the branches. This is mandatory for ADDRESSABLE types,
3146 since we cannot generate temporaries for such, but it saves a
3147 copy in other cases as well. */
3148 if (!is_gimple_reg_type (TREE_TYPE (*from_p)))
3149 {
3150 *expr_p = *from_p;
3151 return gimplify_cond_expr (expr_p, pre_p, post_p, *to_p,
3152 fb_rvalue);
3153 }
3154 else
3155 ret = GS_UNHANDLED;
3156 break;
3157
3158 case CALL_EXPR:
3159 /* For calls that return in memory, give *to_p as the CALL_EXPR's
3160 return slot so that we don't generate a temporary. */
3161 if (!CALL_EXPR_RETURN_SLOT_OPT (*from_p)
3162 && aggregate_value_p (*from_p, *from_p))
3163 {
3164 bool use_target;
3165
3166 if (TREE_CODE (*to_p) == RESULT_DECL
3167 && needs_to_live_in_memory (*to_p))
3168 /* It's always OK to use the return slot directly. */
3169 use_target = true;
3170 else if (!is_gimple_non_addressable (*to_p))
3171 /* Don't use the original target if it's already addressable;
3172 if its address escapes, and the called function uses the
3173 NRV optimization, a conforming program could see *to_p
3174 change before the called function returns; see c++/19317.
3175 When optimizing, the return_slot pass marks more functions
3176 as safe after we have escape info. */
3177 use_target = false;
3178 else if (TREE_CODE (*to_p) != PARM_DECL
3179 && DECL_GIMPLE_FORMAL_TEMP_P (*to_p))
3180 /* Don't use the original target if it's a formal temp; we
3181 don't want to take their addresses. */
3182 use_target = false;
3183 else if (is_gimple_reg_type (TREE_TYPE (*to_p)))
3184 /* Also don't force regs into memory. */
3185 use_target = false;
3186 else
3187 use_target = true;
3188
3189 if (use_target)
3190 {
3191 CALL_EXPR_RETURN_SLOT_OPT (*from_p) = 1;
3192 lang_hooks.mark_addressable (*to_p);
3193 }
3194 }
3195
3196 ret = GS_UNHANDLED;
3197 break;
3198
3199 default:
3200 ret = GS_UNHANDLED;
3201 break;
3202 }
3203
3204 return ret;
3205 }
3206
3207 /* Promote partial stores to COMPLEX variables to total stores. *EXPR_P is
3208 a MODIFY_EXPR with a lhs of a REAL/IMAGPART_EXPR of a variable with
3209 DECL_COMPLEX_GIMPLE_REG_P set. */
3210
3211 static enum gimplify_status
3212 gimplify_modify_expr_complex_part (tree *expr_p, tree *pre_p, bool want_value)
3213 {
3214 enum tree_code code, ocode;
3215 tree lhs, rhs, new_rhs, other, realpart, imagpart;
3216
3217 lhs = TREE_OPERAND (*expr_p, 0);
3218 rhs = TREE_OPERAND (*expr_p, 1);
3219 code = TREE_CODE (lhs);
3220 lhs = TREE_OPERAND (lhs, 0);
3221
3222 ocode = code == REALPART_EXPR ? IMAGPART_EXPR : REALPART_EXPR;
3223 other = build1 (ocode, TREE_TYPE (rhs), lhs);
3224 other = get_formal_tmp_var (other, pre_p);
3225
3226 realpart = code == REALPART_EXPR ? rhs : other;
3227 imagpart = code == REALPART_EXPR ? other : rhs;
3228
3229 if (TREE_CONSTANT (realpart) && TREE_CONSTANT (imagpart))
3230 new_rhs = build_complex (TREE_TYPE (lhs), realpart, imagpart);
3231 else
3232 new_rhs = build2 (COMPLEX_EXPR, TREE_TYPE (lhs), realpart, imagpart);
3233
3234 TREE_OPERAND (*expr_p, 0) = lhs;
3235 TREE_OPERAND (*expr_p, 1) = new_rhs;
3236
3237 if (want_value)
3238 {
3239 append_to_statement_list (*expr_p, pre_p);
3240 *expr_p = rhs;
3241 }
3242
3243 return GS_ALL_DONE;
3244 }
3245
3246 /* Gimplify the MODIFY_EXPR node pointed to by EXPR_P.
3247
3248 modify_expr
3249 : varname '=' rhs
3250 | '*' ID '=' rhs
3251
3252 PRE_P points to the list where side effects that must happen before
3253 *EXPR_P should be stored.
3254
3255 POST_P points to the list where side effects that must happen after
3256 *EXPR_P should be stored.
3257
3258 WANT_VALUE is nonzero iff we want to use the value of this expression
3259 in another expression. */
3260
3261 static enum gimplify_status
3262 gimplify_modify_expr (tree *expr_p, tree *pre_p, tree *post_p, bool want_value)
3263 {
3264 tree *from_p = &TREE_OPERAND (*expr_p, 1);
3265 tree *to_p = &TREE_OPERAND (*expr_p, 0);
3266 enum gimplify_status ret = GS_UNHANDLED;
3267
3268 gcc_assert (TREE_CODE (*expr_p) == MODIFY_EXPR
3269 || TREE_CODE (*expr_p) == INIT_EXPR);
3270
3271 /* The distinction between MODIFY_EXPR and INIT_EXPR is no longer useful. */
3272 if (TREE_CODE (*expr_p) == INIT_EXPR)
3273 TREE_SET_CODE (*expr_p, MODIFY_EXPR);
3274
3275 /* For zero sized types only gimplify the left hand side and right hand side
3276 as statements and throw away the assignment. */
3277 if (zero_sized_type (TREE_TYPE (*from_p)))
3278 {
3279 gimplify_stmt (from_p);
3280 gimplify_stmt (to_p);
3281 append_to_statement_list (*from_p, pre_p);
3282 append_to_statement_list (*to_p, pre_p);
3283 *expr_p = NULL_TREE;
3284 return GS_ALL_DONE;
3285 }
3286
3287 /* See if any simplifications can be done based on what the RHS is. */
3288 ret = gimplify_modify_expr_rhs (expr_p, from_p, to_p, pre_p, post_p,
3289 want_value);
3290 if (ret != GS_UNHANDLED)
3291 return ret;
3292
3293 /* If the value being copied is of variable width, compute the length
3294 of the copy into a WITH_SIZE_EXPR. Note that we need to do this
3295 before gimplifying any of the operands so that we can resolve any
3296 PLACEHOLDER_EXPRs in the size. Also note that the RTL expander uses
3297 the size of the expression to be copied, not of the destination, so
3298 that is what we must here. */
3299 maybe_with_size_expr (from_p);
3300
3301 ret = gimplify_expr (to_p, pre_p, post_p, is_gimple_lvalue, fb_lvalue);
3302 if (ret == GS_ERROR)
3303 return ret;
3304
3305 ret = gimplify_expr (from_p, pre_p, post_p,
3306 rhs_predicate_for (*to_p), fb_rvalue);
3307 if (ret == GS_ERROR)
3308 return ret;
3309
3310 /* Now see if the above changed *from_p to something we handle specially. */
3311 ret = gimplify_modify_expr_rhs (expr_p, from_p, to_p, pre_p, post_p,
3312 want_value);
3313 if (ret != GS_UNHANDLED)
3314 return ret;
3315
3316 /* If we've got a variable sized assignment between two lvalues (i.e. does
3317 not involve a call), then we can make things a bit more straightforward
3318 by converting the assignment to memcpy or memset. */
3319 if (TREE_CODE (*from_p) == WITH_SIZE_EXPR)
3320 {
3321 tree from = TREE_OPERAND (*from_p, 0);
3322 tree size = TREE_OPERAND (*from_p, 1);
3323
3324 if (TREE_CODE (from) == CONSTRUCTOR)
3325 return gimplify_modify_expr_to_memset (expr_p, size, want_value);
3326 if (is_gimple_addressable (from))
3327 {
3328 *from_p = from;
3329 return gimplify_modify_expr_to_memcpy (expr_p, size, want_value);
3330 }
3331 }
3332
3333 /* Transform partial stores to non-addressable complex variables into
3334 total stores. This allows us to use real instead of virtual operands
3335 for these variables, which improves optimization. */
3336 if ((TREE_CODE (*to_p) == REALPART_EXPR
3337 || TREE_CODE (*to_p) == IMAGPART_EXPR)
3338 && is_gimple_reg (TREE_OPERAND (*to_p, 0)))
3339 return gimplify_modify_expr_complex_part (expr_p, pre_p, want_value);
3340
3341 if (gimplify_ctxp->into_ssa && is_gimple_reg (*to_p))
3342 {
3343 /* If we've somehow already got an SSA_NAME on the LHS, then
3344 we're probably modified it twice. Not good. */
3345 gcc_assert (TREE_CODE (*to_p) != SSA_NAME);
3346 *to_p = make_ssa_name (*to_p, *expr_p);
3347 }
3348
3349 if (want_value)
3350 {
3351 append_to_statement_list (*expr_p, pre_p);
3352 *expr_p = *to_p;
3353 return GS_OK;
3354 }
3355
3356 return GS_ALL_DONE;
3357 }
3358
3359 /* Gimplify a comparison between two variable-sized objects. Do this
3360 with a call to BUILT_IN_MEMCMP. */
3361
3362 static enum gimplify_status
3363 gimplify_variable_sized_compare (tree *expr_p)
3364 {
3365 tree op0 = TREE_OPERAND (*expr_p, 0);
3366 tree op1 = TREE_OPERAND (*expr_p, 1);
3367 tree args, t, dest;
3368
3369 t = TYPE_SIZE_UNIT (TREE_TYPE (op0));
3370 t = unshare_expr (t);
3371 t = SUBSTITUTE_PLACEHOLDER_IN_EXPR (t, op0);
3372 args = tree_cons (NULL, t, NULL);
3373 t = build_fold_addr_expr (op1);
3374 args = tree_cons (NULL, t, args);
3375 dest = build_fold_addr_expr (op0);
3376 args = tree_cons (NULL, dest, args);
3377 t = implicit_built_in_decls[BUILT_IN_MEMCMP];
3378 t = build_function_call_expr (t, args);
3379 *expr_p
3380 = build2 (TREE_CODE (*expr_p), TREE_TYPE (*expr_p), t, integer_zero_node);
3381
3382 return GS_OK;
3383 }
3384
3385 /* Gimplify TRUTH_ANDIF_EXPR and TRUTH_ORIF_EXPR expressions. EXPR_P
3386 points to the expression to gimplify.
3387
3388 Expressions of the form 'a && b' are gimplified to:
3389
3390 a && b ? true : false
3391
3392 gimplify_cond_expr will do the rest.
3393
3394 PRE_P points to the list where side effects that must happen before
3395 *EXPR_P should be stored. */
3396
3397 static enum gimplify_status
3398 gimplify_boolean_expr (tree *expr_p)
3399 {
3400 /* Preserve the original type of the expression. */
3401 tree type = TREE_TYPE (*expr_p);
3402
3403 *expr_p = build3 (COND_EXPR, type, *expr_p,
3404 convert (type, boolean_true_node),
3405 convert (type, boolean_false_node));
3406
3407 return GS_OK;
3408 }
3409
3410 /* Gimplifies an expression sequence. This function gimplifies each
3411 expression and re-writes the original expression with the last
3412 expression of the sequence in GIMPLE form.
3413
3414 PRE_P points to the list where the side effects for all the
3415 expressions in the sequence will be emitted.
3416
3417 WANT_VALUE is true when the result of the last COMPOUND_EXPR is used. */
3418 /* ??? Should rearrange to share the pre-queue with all the indirect
3419 invocations of gimplify_expr. Would probably save on creations
3420 of statement_list nodes. */
3421
3422 static enum gimplify_status
3423 gimplify_compound_expr (tree *expr_p, tree *pre_p, bool want_value)
3424 {
3425 tree t = *expr_p;
3426
3427 do
3428 {
3429 tree *sub_p = &TREE_OPERAND (t, 0);
3430
3431 if (TREE_CODE (*sub_p) == COMPOUND_EXPR)
3432 gimplify_compound_expr (sub_p, pre_p, false);
3433 else
3434 gimplify_stmt (sub_p);
3435 append_to_statement_list (*sub_p, pre_p);
3436
3437 t = TREE_OPERAND (t, 1);
3438 }
3439 while (TREE_CODE (t) == COMPOUND_EXPR);
3440
3441 *expr_p = t;
3442 if (want_value)
3443 return GS_OK;
3444 else
3445 {
3446 gimplify_stmt (expr_p);
3447 return GS_ALL_DONE;
3448 }
3449 }
3450
3451 /* Gimplifies a statement list. These may be created either by an
3452 enlightened front-end, or by shortcut_cond_expr. */
3453
3454 static enum gimplify_status
3455 gimplify_statement_list (tree *expr_p)
3456 {
3457 tree_stmt_iterator i = tsi_start (*expr_p);
3458
3459 while (!tsi_end_p (i))
3460 {
3461 tree t;
3462
3463 gimplify_stmt (tsi_stmt_ptr (i));
3464
3465 t = tsi_stmt (i);
3466 if (t == NULL)
3467 tsi_delink (&i);
3468 else if (TREE_CODE (t) == STATEMENT_LIST)
3469 {
3470 tsi_link_before (&i, t, TSI_SAME_STMT);
3471 tsi_delink (&i);
3472 }
3473 else
3474 tsi_next (&i);
3475 }
3476
3477 return GS_ALL_DONE;
3478 }
3479
3480 /* Gimplify a SAVE_EXPR node. EXPR_P points to the expression to
3481 gimplify. After gimplification, EXPR_P will point to a new temporary
3482 that holds the original value of the SAVE_EXPR node.
3483
3484 PRE_P points to the list where side effects that must happen before
3485 *EXPR_P should be stored. */
3486
3487 static enum gimplify_status
3488 gimplify_save_expr (tree *expr_p, tree *pre_p, tree *post_p)
3489 {
3490 enum gimplify_status ret = GS_ALL_DONE;
3491 tree val;
3492
3493 gcc_assert (TREE_CODE (*expr_p) == SAVE_EXPR);
3494 val = TREE_OPERAND (*expr_p, 0);
3495
3496 /* If the SAVE_EXPR has not been resolved, then evaluate it once. */
3497 if (!SAVE_EXPR_RESOLVED_P (*expr_p))
3498 {
3499 /* The operand may be a void-valued expression such as SAVE_EXPRs
3500 generated by the Java frontend for class initialization. It is
3501 being executed only for its side-effects. */
3502 if (TREE_TYPE (val) == void_type_node)
3503 {
3504 ret = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p, post_p,
3505 is_gimple_stmt, fb_none);
3506 append_to_statement_list (TREE_OPERAND (*expr_p, 0), pre_p);
3507 val = NULL;
3508 }
3509 else
3510 val = get_initialized_tmp_var (val, pre_p, post_p);
3511
3512 TREE_OPERAND (*expr_p, 0) = val;
3513 SAVE_EXPR_RESOLVED_P (*expr_p) = 1;
3514 }
3515
3516 *expr_p = val;
3517
3518 return ret;
3519 }
3520
3521 /* Re-write the ADDR_EXPR node pointed to by EXPR_P
3522
3523 unary_expr
3524 : ...
3525 | '&' varname
3526 ...
3527
3528 PRE_P points to the list where side effects that must happen before
3529 *EXPR_P should be stored.
3530
3531 POST_P points to the list where side effects that must happen after
3532 *EXPR_P should be stored. */
3533
3534 static enum gimplify_status
3535 gimplify_addr_expr (tree *expr_p, tree *pre_p, tree *post_p)
3536 {
3537 tree expr = *expr_p;
3538 tree op0 = TREE_OPERAND (expr, 0);
3539 enum gimplify_status ret;
3540
3541 switch (TREE_CODE (op0))
3542 {
3543 case INDIRECT_REF:
3544 case MISALIGNED_INDIRECT_REF:
3545 do_indirect_ref:
3546 /* Check if we are dealing with an expression of the form '&*ptr'.
3547 While the front end folds away '&*ptr' into 'ptr', these
3548 expressions may be generated internally by the compiler (e.g.,
3549 builtins like __builtin_va_end). */
3550 /* Caution: the silent array decomposition semantics we allow for
3551 ADDR_EXPR means we can't always discard the pair. */
3552 /* Gimplification of the ADDR_EXPR operand may drop
3553 cv-qualification conversions, so make sure we add them if
3554 needed. */
3555 {
3556 tree op00 = TREE_OPERAND (op0, 0);
3557 tree t_expr = TREE_TYPE (expr);
3558 tree t_op00 = TREE_TYPE (op00);
3559
3560 if (!lang_hooks.types_compatible_p (t_expr, t_op00))
3561 {
3562 #ifdef ENABLE_CHECKING
3563 tree t_op0 = TREE_TYPE (op0);
3564 gcc_assert (POINTER_TYPE_P (t_expr)
3565 && cpt_same_type (TREE_CODE (t_op0) == ARRAY_TYPE
3566 ? TREE_TYPE (t_op0) : t_op0,
3567 TREE_TYPE (t_expr))
3568 && POINTER_TYPE_P (t_op00)
3569 && cpt_same_type (t_op0, TREE_TYPE (t_op00)));
3570 #endif
3571 op00 = fold_convert (TREE_TYPE (expr), op00);
3572 }
3573 *expr_p = op00;
3574 ret = GS_OK;
3575 }
3576 break;
3577
3578 case VIEW_CONVERT_EXPR:
3579 /* Take the address of our operand and then convert it to the type of
3580 this ADDR_EXPR.
3581
3582 ??? The interactions of VIEW_CONVERT_EXPR and aliasing is not at
3583 all clear. The impact of this transformation is even less clear. */
3584
3585 /* If the operand is a useless conversion, look through it. Doing so
3586 guarantees that the ADDR_EXPR and its operand will remain of the
3587 same type. */
3588 if (tree_ssa_useless_type_conversion (TREE_OPERAND (op0, 0)))
3589 op0 = TREE_OPERAND (op0, 0);
3590
3591 *expr_p = fold_convert (TREE_TYPE (expr),
3592 build_fold_addr_expr (TREE_OPERAND (op0, 0)));
3593 ret = GS_OK;
3594 break;
3595
3596 default:
3597 /* We use fb_either here because the C frontend sometimes takes
3598 the address of a call that returns a struct; see
3599 gcc.dg/c99-array-lval-1.c. The gimplifier will correctly make
3600 the implied temporary explicit. */
3601 ret = gimplify_expr (&TREE_OPERAND (expr, 0), pre_p, post_p,
3602 is_gimple_addressable, fb_either);
3603 if (ret != GS_ERROR)
3604 {
3605 op0 = TREE_OPERAND (expr, 0);
3606
3607 /* For various reasons, the gimplification of the expression
3608 may have made a new INDIRECT_REF. */
3609 if (TREE_CODE (op0) == INDIRECT_REF)
3610 goto do_indirect_ref;
3611
3612 /* Make sure TREE_INVARIANT, TREE_CONSTANT, and TREE_SIDE_EFFECTS
3613 is set properly. */
3614 recompute_tree_invariant_for_addr_expr (expr);
3615
3616 /* Mark the RHS addressable. */
3617 lang_hooks.mark_addressable (TREE_OPERAND (expr, 0));
3618 }
3619 break;
3620 }
3621
3622 return ret;
3623 }
3624
3625 /* Gimplify the operands of an ASM_EXPR. Input operands should be a gimple
3626 value; output operands should be a gimple lvalue. */
3627
3628 static enum gimplify_status
3629 gimplify_asm_expr (tree *expr_p, tree *pre_p, tree *post_p)
3630 {
3631 tree expr = *expr_p;
3632 int noutputs = list_length (ASM_OUTPUTS (expr));
3633 const char **oconstraints
3634 = (const char **) alloca ((noutputs) * sizeof (const char *));
3635 int i;
3636 tree link;
3637 const char *constraint;
3638 bool allows_mem, allows_reg, is_inout;
3639 enum gimplify_status ret, tret;
3640
3641 ret = GS_ALL_DONE;
3642 for (i = 0, link = ASM_OUTPUTS (expr); link; ++i, link = TREE_CHAIN (link))
3643 {
3644 size_t constraint_len;
3645 oconstraints[i] = constraint
3646 = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (link)));
3647 constraint_len = strlen (constraint);
3648 if (constraint_len == 0)
3649 continue;
3650
3651 parse_output_constraint (&constraint, i, 0, 0,
3652 &allows_mem, &allows_reg, &is_inout);
3653
3654 if (!allows_reg && allows_mem)
3655 lang_hooks.mark_addressable (TREE_VALUE (link));
3656
3657 tret = gimplify_expr (&TREE_VALUE (link), pre_p, post_p,
3658 is_inout ? is_gimple_min_lval : is_gimple_lvalue,
3659 fb_lvalue | fb_mayfail);
3660 if (tret == GS_ERROR)
3661 {
3662 error ("invalid lvalue in asm output %d", i);
3663 ret = tret;
3664 }
3665
3666 if (is_inout)
3667 {
3668 /* An input/output operand. To give the optimizers more
3669 flexibility, split it into separate input and output
3670 operands. */
3671 tree input;
3672 char buf[10];
3673
3674 /* Turn the in/out constraint into an output constraint. */
3675 char *p = xstrdup (constraint);
3676 p[0] = '=';
3677 TREE_VALUE (TREE_PURPOSE (link)) = build_string (constraint_len, p);
3678
3679 /* And add a matching input constraint. */
3680 if (allows_reg)
3681 {
3682 sprintf (buf, "%d", i);
3683
3684 /* If there are multiple alternatives in the constraint,
3685 handle each of them individually. Those that allow register
3686 will be replaced with operand number, the others will stay
3687 unchanged. */
3688 if (strchr (p, ',') != NULL)
3689 {
3690 size_t len = 0, buflen = strlen (buf);
3691 char *beg, *end, *str, *dst;
3692
3693 for (beg = p + 1;;)
3694 {
3695 end = strchr (beg, ',');
3696 if (end == NULL)
3697 end = strchr (beg, '\0');
3698 if ((size_t) (end - beg) < buflen)
3699 len += buflen + 1;
3700 else
3701 len += end - beg + 1;
3702 if (*end)
3703 beg = end + 1;
3704 else
3705 break;
3706 }
3707
3708 str = (char *) alloca (len);
3709 for (beg = p + 1, dst = str;;)
3710 {
3711 const char *tem;
3712 bool mem_p, reg_p, inout_p;
3713
3714 end = strchr (beg, ',');
3715 if (end)
3716 *end = '\0';
3717 beg[-1] = '=';
3718 tem = beg - 1;
3719 parse_output_constraint (&tem, i, 0, 0,
3720 &mem_p, &reg_p, &inout_p);
3721 if (dst != str)
3722 *dst++ = ',';
3723 if (reg_p)
3724 {
3725 memcpy (dst, buf, buflen);
3726 dst += buflen;
3727 }
3728 else
3729 {
3730 if (end)
3731 len = end - beg;
3732 else
3733 len = strlen (beg);
3734 memcpy (dst, beg, len);
3735 dst += len;
3736 }
3737 if (end)
3738 beg = end + 1;
3739 else
3740 break;
3741 }
3742 *dst = '\0';
3743 input = build_string (dst - str, str);
3744 }
3745 else
3746 input = build_string (strlen (buf), buf);
3747 }
3748 else
3749 input = build_string (constraint_len - 1, constraint + 1);
3750
3751 free (p);
3752
3753 input = build_tree_list (build_tree_list (NULL_TREE, input),
3754 unshare_expr (TREE_VALUE (link)));
3755 ASM_INPUTS (expr) = chainon (ASM_INPUTS (expr), input);
3756 }
3757 }
3758
3759 for (link = ASM_INPUTS (expr); link; ++i, link = TREE_CHAIN (link))
3760 {
3761 constraint
3762 = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (link)));
3763 parse_input_constraint (&constraint, 0, 0, noutputs, 0,
3764 oconstraints, &allows_mem, &allows_reg);
3765
3766 /* If the operand is a memory input, it should be an lvalue. */
3767 if (!allows_reg && allows_mem)
3768 {
3769 lang_hooks.mark_addressable (TREE_VALUE (link));
3770 tret = gimplify_expr (&TREE_VALUE (link), pre_p, post_p,
3771 is_gimple_lvalue, fb_lvalue | fb_mayfail);
3772 if (tret == GS_ERROR)
3773 {
3774 error ("memory input %d is not directly addressable", i);
3775 ret = tret;
3776 }
3777 }
3778 else
3779 {
3780 tret = gimplify_expr (&TREE_VALUE (link), pre_p, post_p,
3781 is_gimple_asm_val, fb_rvalue);
3782 if (tret == GS_ERROR)
3783 ret = tret;
3784 }
3785 }
3786
3787 return ret;
3788 }
3789
3790 /* Gimplify a CLEANUP_POINT_EXPR. Currently this works by adding
3791 WITH_CLEANUP_EXPRs to the prequeue as we encounter cleanups while
3792 gimplifying the body, and converting them to TRY_FINALLY_EXPRs when we
3793 return to this function.
3794
3795 FIXME should we complexify the prequeue handling instead? Or use flags
3796 for all the cleanups and let the optimizer tighten them up? The current
3797 code seems pretty fragile; it will break on a cleanup within any
3798 non-conditional nesting. But any such nesting would be broken, anyway;
3799 we can't write a TRY_FINALLY_EXPR that starts inside a nesting construct
3800 and continues out of it. We can do that at the RTL level, though, so
3801 having an optimizer to tighten up try/finally regions would be a Good
3802 Thing. */
3803
3804 static enum gimplify_status
3805 gimplify_cleanup_point_expr (tree *expr_p, tree *pre_p)
3806 {
3807 tree_stmt_iterator iter;
3808 tree body;
3809
3810 tree temp = voidify_wrapper_expr (*expr_p, NULL);
3811
3812 /* We only care about the number of conditions between the innermost
3813 CLEANUP_POINT_EXPR and the cleanup. So save and reset the count and
3814 any cleanups collected outside the CLEANUP_POINT_EXPR. */
3815 int old_conds = gimplify_ctxp->conditions;
3816 tree old_cleanups = gimplify_ctxp->conditional_cleanups;
3817 gimplify_ctxp->conditions = 0;
3818 gimplify_ctxp->conditional_cleanups = NULL_TREE;
3819
3820 body = TREE_OPERAND (*expr_p, 0);
3821 gimplify_to_stmt_list (&body);
3822
3823 gimplify_ctxp->conditions = old_conds;
3824 gimplify_ctxp->conditional_cleanups = old_cleanups;
3825
3826 for (iter = tsi_start (body); !tsi_end_p (iter); )
3827 {
3828 tree *wce_p = tsi_stmt_ptr (iter);
3829 tree wce = *wce_p;
3830
3831 if (TREE_CODE (wce) == WITH_CLEANUP_EXPR)
3832 {
3833 if (tsi_one_before_end_p (iter))
3834 {
3835 tsi_link_before (&iter, TREE_OPERAND (wce, 0), TSI_SAME_STMT);
3836 tsi_delink (&iter);
3837 break;
3838 }
3839 else
3840 {
3841 tree sl, tfe;
3842 enum tree_code code;
3843
3844 if (CLEANUP_EH_ONLY (wce))
3845 code = TRY_CATCH_EXPR;
3846 else
3847 code = TRY_FINALLY_EXPR;
3848
3849 sl = tsi_split_statement_list_after (&iter);
3850 tfe = build2 (code, void_type_node, sl, NULL_TREE);
3851 append_to_statement_list (TREE_OPERAND (wce, 0),
3852 &TREE_OPERAND (tfe, 1));
3853 *wce_p = tfe;
3854 iter = tsi_start (sl);
3855 }
3856 }
3857 else
3858 tsi_next (&iter);
3859 }
3860
3861 if (temp)
3862 {
3863 *expr_p = temp;
3864 append_to_statement_list (body, pre_p);
3865 return GS_OK;
3866 }
3867 else
3868 {
3869 *expr_p = body;
3870 return GS_ALL_DONE;
3871 }
3872 }
3873
3874 /* Insert a cleanup marker for gimplify_cleanup_point_expr. CLEANUP
3875 is the cleanup action required. */
3876
3877 static void
3878 gimple_push_cleanup (tree var, tree cleanup, bool eh_only, tree *pre_p)
3879 {
3880 tree wce;
3881
3882 /* Errors can result in improperly nested cleanups. Which results in
3883 confusion when trying to resolve the WITH_CLEANUP_EXPR. */
3884 if (errorcount || sorrycount)
3885 return;
3886
3887 if (gimple_conditional_context ())
3888 {
3889 /* If we're in a conditional context, this is more complex. We only
3890 want to run the cleanup if we actually ran the initialization that
3891 necessitates it, but we want to run it after the end of the
3892 conditional context. So we wrap the try/finally around the
3893 condition and use a flag to determine whether or not to actually
3894 run the destructor. Thus
3895
3896 test ? f(A()) : 0
3897
3898 becomes (approximately)
3899
3900 flag = 0;
3901 try {
3902 if (test) { A::A(temp); flag = 1; val = f(temp); }
3903 else { val = 0; }
3904 } finally {
3905 if (flag) A::~A(temp);
3906 }
3907 val
3908 */
3909
3910 tree flag = create_tmp_var (boolean_type_node, "cleanup");
3911 tree ffalse = build2 (MODIFY_EXPR, void_type_node, flag,
3912 boolean_false_node);
3913 tree ftrue = build2 (MODIFY_EXPR, void_type_node, flag,
3914 boolean_true_node);
3915 cleanup = build3 (COND_EXPR, void_type_node, flag, cleanup, NULL);
3916 wce = build1 (WITH_CLEANUP_EXPR, void_type_node, cleanup);
3917 append_to_statement_list (ffalse, &gimplify_ctxp->conditional_cleanups);
3918 append_to_statement_list (wce, &gimplify_ctxp->conditional_cleanups);
3919 append_to_statement_list (ftrue, pre_p);
3920
3921 /* Because of this manipulation, and the EH edges that jump
3922 threading cannot redirect, the temporary (VAR) will appear
3923 to be used uninitialized. Don't warn. */
3924 TREE_NO_WARNING (var) = 1;
3925 }
3926 else
3927 {
3928 wce = build1 (WITH_CLEANUP_EXPR, void_type_node, cleanup);
3929 CLEANUP_EH_ONLY (wce) = eh_only;
3930 append_to_statement_list (wce, pre_p);
3931 }
3932
3933 gimplify_stmt (&TREE_OPERAND (wce, 0));
3934 }
3935
3936 /* Gimplify a TARGET_EXPR which doesn't appear on the rhs of an INIT_EXPR. */
3937
3938 static enum gimplify_status
3939 gimplify_target_expr (tree *expr_p, tree *pre_p, tree *post_p)
3940 {
3941 tree targ = *expr_p;
3942 tree temp = TARGET_EXPR_SLOT (targ);
3943 tree init = TARGET_EXPR_INITIAL (targ);
3944 enum gimplify_status ret;
3945
3946 if (init)
3947 {
3948 /* TARGET_EXPR temps aren't part of the enclosing block, so add it
3949 to the temps list. */
3950 gimple_add_tmp_var (temp);
3951
3952 /* If TARGET_EXPR_INITIAL is void, then the mere evaluation of the
3953 expression is supposed to initialize the slot. */
3954 if (VOID_TYPE_P (TREE_TYPE (init)))
3955 ret = gimplify_expr (&init, pre_p, post_p, is_gimple_stmt, fb_none);
3956 else
3957 {
3958 /* Special handling for BIND_EXPR can result in fewer temps. */
3959 ret = GS_OK;
3960 if (TREE_CODE (init) == BIND_EXPR)
3961 gimplify_bind_expr (&init, temp, pre_p);
3962 if (init != temp)
3963 {
3964 init = build2 (MODIFY_EXPR, void_type_node, temp, init);
3965 ret = gimplify_expr (&init, pre_p, post_p, is_gimple_stmt,
3966 fb_none);
3967 }
3968 }
3969 if (ret == GS_ERROR)
3970 return GS_ERROR;
3971 append_to_statement_list (init, pre_p);
3972
3973 /* If needed, push the cleanup for the temp. */
3974 if (TARGET_EXPR_CLEANUP (targ))
3975 {
3976 gimplify_stmt (&TARGET_EXPR_CLEANUP (targ));
3977 gimple_push_cleanup (temp, TARGET_EXPR_CLEANUP (targ),
3978 CLEANUP_EH_ONLY (targ), pre_p);
3979 }
3980
3981 /* Only expand this once. */
3982 TREE_OPERAND (targ, 3) = init;
3983 TARGET_EXPR_INITIAL (targ) = NULL_TREE;
3984 }
3985 else
3986 /* We should have expanded this before. */
3987 gcc_assert (DECL_SEEN_IN_BIND_EXPR_P (temp));
3988
3989 *expr_p = temp;
3990 return GS_OK;
3991 }
3992
3993 /* Gimplification of expression trees. */
3994
3995 /* Gimplify an expression which appears at statement context; usually, this
3996 means replacing it with a suitably gimple STATEMENT_LIST. */
3997
3998 void
3999 gimplify_stmt (tree *stmt_p)
4000 {
4001 gimplify_expr (stmt_p, NULL, NULL, is_gimple_stmt, fb_none);
4002 }
4003
4004 /* Similarly, but force the result to be a STATEMENT_LIST. */
4005
4006 void
4007 gimplify_to_stmt_list (tree *stmt_p)
4008 {
4009 gimplify_stmt (stmt_p);
4010 if (!*stmt_p)
4011 *stmt_p = alloc_stmt_list ();
4012 else if (TREE_CODE (*stmt_p) != STATEMENT_LIST)
4013 {
4014 tree t = *stmt_p;
4015 *stmt_p = alloc_stmt_list ();
4016 append_to_statement_list (t, stmt_p);
4017 }
4018 }
4019
4020
4021 /* Gimplifies the expression tree pointed to by EXPR_P. Return 0 if
4022 gimplification failed.
4023
4024 PRE_P points to the list where side effects that must happen before
4025 EXPR should be stored.
4026
4027 POST_P points to the list where side effects that must happen after
4028 EXPR should be stored, or NULL if there is no suitable list. In
4029 that case, we copy the result to a temporary, emit the
4030 post-effects, and then return the temporary.
4031
4032 GIMPLE_TEST_F points to a function that takes a tree T and
4033 returns nonzero if T is in the GIMPLE form requested by the
4034 caller. The GIMPLE predicates are in tree-gimple.c.
4035
4036 This test is used twice. Before gimplification, the test is
4037 invoked to determine whether *EXPR_P is already gimple enough. If
4038 that fails, *EXPR_P is gimplified according to its code and
4039 GIMPLE_TEST_F is called again. If the test still fails, then a new
4040 temporary variable is created and assigned the value of the
4041 gimplified expression.
4042
4043 FALLBACK tells the function what sort of a temporary we want. If the 1
4044 bit is set, an rvalue is OK. If the 2 bit is set, an lvalue is OK.
4045 If both are set, either is OK, but an lvalue is preferable.
4046
4047 The return value is either GS_ERROR or GS_ALL_DONE, since this function
4048 iterates until solution. */
4049
4050 enum gimplify_status
4051 gimplify_expr (tree *expr_p, tree *pre_p, tree *post_p,
4052 bool (* gimple_test_f) (tree), fallback_t fallback)
4053 {
4054 tree tmp;
4055 tree internal_pre = NULL_TREE;
4056 tree internal_post = NULL_TREE;
4057 tree save_expr;
4058 int is_statement = (pre_p == NULL);
4059 location_t saved_location;
4060 enum gimplify_status ret;
4061
4062 save_expr = *expr_p;
4063 if (save_expr == NULL_TREE)
4064 return GS_ALL_DONE;
4065
4066 /* We used to check the predicate here and return immediately if it
4067 succeeds. This is wrong; the design is for gimplification to be
4068 idempotent, and for the predicates to only test for valid forms, not
4069 whether they are fully simplified. */
4070
4071 /* Set up our internal queues if needed. */
4072 if (pre_p == NULL)
4073 pre_p = &internal_pre;
4074 if (post_p == NULL)
4075 post_p = &internal_post;
4076
4077 saved_location = input_location;
4078 if (save_expr != error_mark_node
4079 && EXPR_HAS_LOCATION (*expr_p))
4080 input_location = EXPR_LOCATION (*expr_p);
4081
4082 /* Loop over the specific gimplifiers until the toplevel node
4083 remains the same. */
4084 do
4085 {
4086 /* Strip away as many useless type conversions as possible
4087 at the toplevel. */
4088 STRIP_USELESS_TYPE_CONVERSION (*expr_p);
4089
4090 /* Remember the expr. */
4091 save_expr = *expr_p;
4092
4093 /* Die, die, die, my darling. */
4094 if (save_expr == error_mark_node
4095 || (TREE_TYPE (save_expr)
4096 && TREE_TYPE (save_expr) == error_mark_node))
4097 {
4098 ret = GS_ERROR;
4099 break;
4100 }
4101
4102 /* Do any language-specific gimplification. */
4103 ret = lang_hooks.gimplify_expr (expr_p, pre_p, post_p);
4104 if (ret == GS_OK)
4105 {
4106 if (*expr_p == NULL_TREE)
4107 break;
4108 if (*expr_p != save_expr)
4109 continue;
4110 }
4111 else if (ret != GS_UNHANDLED)
4112 break;
4113
4114 ret = GS_OK;
4115 switch (TREE_CODE (*expr_p))
4116 {
4117 /* First deal with the special cases. */
4118
4119 case POSTINCREMENT_EXPR:
4120 case POSTDECREMENT_EXPR:
4121 case PREINCREMENT_EXPR:
4122 case PREDECREMENT_EXPR:
4123 ret = gimplify_self_mod_expr (expr_p, pre_p, post_p,
4124 fallback != fb_none);
4125 break;
4126
4127 case ARRAY_REF:
4128 case ARRAY_RANGE_REF:
4129 case REALPART_EXPR:
4130 case IMAGPART_EXPR:
4131 case COMPONENT_REF:
4132 case VIEW_CONVERT_EXPR:
4133 ret = gimplify_compound_lval (expr_p, pre_p, post_p,
4134 fallback ? fallback : fb_rvalue);
4135 break;
4136
4137 case COND_EXPR:
4138 ret = gimplify_cond_expr (expr_p, pre_p, post_p, NULL_TREE,
4139 fallback);
4140 /* C99 code may assign to an array in a structure value of a
4141 conditional expression, and this has undefined behavior
4142 only on execution, so create a temporary if an lvalue is
4143 required. */
4144 if (fallback == fb_lvalue)
4145 {
4146 *expr_p = get_initialized_tmp_var (*expr_p, pre_p, post_p);
4147 lang_hooks.mark_addressable (*expr_p);
4148 }
4149 break;
4150
4151 case CALL_EXPR:
4152 ret = gimplify_call_expr (expr_p, pre_p, fallback != fb_none);
4153 /* C99 code may assign to an array in a structure returned
4154 from a function, and this has undefined behavior only on
4155 execution, so create a temporary if an lvalue is
4156 required. */
4157 if (fallback == fb_lvalue)
4158 {
4159 *expr_p = get_initialized_tmp_var (*expr_p, pre_p, post_p);
4160 lang_hooks.mark_addressable (*expr_p);
4161 }
4162 break;
4163
4164 case TREE_LIST:
4165 gcc_unreachable ();
4166
4167 case COMPOUND_EXPR:
4168 ret = gimplify_compound_expr (expr_p, pre_p, fallback != fb_none);
4169 break;
4170
4171 case MODIFY_EXPR:
4172 case INIT_EXPR:
4173 ret = gimplify_modify_expr (expr_p, pre_p, post_p,
4174 fallback != fb_none);
4175 break;
4176
4177 case TRUTH_ANDIF_EXPR:
4178 case TRUTH_ORIF_EXPR:
4179 ret = gimplify_boolean_expr (expr_p);
4180 break;
4181
4182 case TRUTH_NOT_EXPR:
4183 TREE_OPERAND (*expr_p, 0)
4184 = gimple_boolify (TREE_OPERAND (*expr_p, 0));
4185 ret = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p, post_p,
4186 is_gimple_val, fb_rvalue);
4187 recalculate_side_effects (*expr_p);
4188 break;
4189
4190 case ADDR_EXPR:
4191 ret = gimplify_addr_expr (expr_p, pre_p, post_p);
4192 break;
4193
4194 case VA_ARG_EXPR:
4195 ret = gimplify_va_arg_expr (expr_p, pre_p, post_p);
4196 break;
4197
4198 case CONVERT_EXPR:
4199 case NOP_EXPR:
4200 if (IS_EMPTY_STMT (*expr_p))
4201 {
4202 ret = GS_ALL_DONE;
4203 break;
4204 }
4205
4206 if (VOID_TYPE_P (TREE_TYPE (*expr_p))
4207 || fallback == fb_none)
4208 {
4209 /* Just strip a conversion to void (or in void context) and
4210 try again. */
4211 *expr_p = TREE_OPERAND (*expr_p, 0);
4212 break;
4213 }
4214
4215 ret = gimplify_conversion (expr_p);
4216 if (ret == GS_ERROR)
4217 break;
4218 if (*expr_p != save_expr)
4219 break;
4220 /* FALLTHRU */
4221
4222 case FIX_TRUNC_EXPR:
4223 case FIX_CEIL_EXPR:
4224 case FIX_FLOOR_EXPR:
4225 case FIX_ROUND_EXPR:
4226 /* unary_expr: ... | '(' cast ')' val | ... */
4227 ret = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p, post_p,
4228 is_gimple_val, fb_rvalue);
4229 recalculate_side_effects (*expr_p);
4230 break;
4231
4232 case INDIRECT_REF:
4233 *expr_p = fold_indirect_ref (*expr_p);
4234 if (*expr_p != save_expr)
4235 break;
4236 /* else fall through. */
4237 case ALIGN_INDIRECT_REF:
4238 case MISALIGNED_INDIRECT_REF:
4239 ret = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p, post_p,
4240 is_gimple_reg, fb_rvalue);
4241 recalculate_side_effects (*expr_p);
4242 break;
4243
4244 /* Constants need not be gimplified. */
4245 case INTEGER_CST:
4246 case REAL_CST:
4247 case STRING_CST:
4248 case COMPLEX_CST:
4249 case VECTOR_CST:
4250 ret = GS_ALL_DONE;
4251 break;
4252
4253 case CONST_DECL:
4254 /* If we require an lvalue, such as for ADDR_EXPR, retain the
4255 CONST_DECL node. Otherwise the decl is replaceable by its
4256 value. */
4257 /* ??? Should be == fb_lvalue, but ADDR_EXPR passes fb_either. */
4258 if (fallback & fb_lvalue)
4259 ret = GS_ALL_DONE;
4260 else
4261 *expr_p = DECL_INITIAL (*expr_p);
4262 break;
4263
4264 case DECL_EXPR:
4265 ret = gimplify_decl_expr (expr_p);
4266 break;
4267
4268 case EXC_PTR_EXPR:
4269 /* FIXME make this a decl. */
4270 ret = GS_ALL_DONE;
4271 break;
4272
4273 case BIND_EXPR:
4274 ret = gimplify_bind_expr (expr_p, NULL, pre_p);
4275 break;
4276
4277 case LOOP_EXPR:
4278 ret = gimplify_loop_expr (expr_p, pre_p);
4279 break;
4280
4281 case SWITCH_EXPR:
4282 ret = gimplify_switch_expr (expr_p, pre_p);
4283 break;
4284
4285 case EXIT_EXPR:
4286 ret = gimplify_exit_expr (expr_p);
4287 break;
4288
4289 case GOTO_EXPR:
4290 /* If the target is not LABEL, then it is a computed jump
4291 and the target needs to be gimplified. */
4292 if (TREE_CODE (GOTO_DESTINATION (*expr_p)) != LABEL_DECL)
4293 ret = gimplify_expr (&GOTO_DESTINATION (*expr_p), pre_p,
4294 NULL, is_gimple_val, fb_rvalue);
4295 break;
4296
4297 case LABEL_EXPR:
4298 ret = GS_ALL_DONE;
4299 gcc_assert (decl_function_context (LABEL_EXPR_LABEL (*expr_p))
4300 == current_function_decl);
4301 break;
4302
4303 case CASE_LABEL_EXPR:
4304 ret = gimplify_case_label_expr (expr_p);
4305 break;
4306
4307 case RETURN_EXPR:
4308 ret = gimplify_return_expr (*expr_p, pre_p);
4309 break;
4310
4311 case CONSTRUCTOR:
4312 /* Don't reduce this in place; let gimplify_init_constructor work its
4313 magic. Buf if we're just elaborating this for side effects, just
4314 gimplify any element that has side-effects. */
4315 if (fallback == fb_none)
4316 {
4317 unsigned HOST_WIDE_INT ix;
4318 constructor_elt *ce;
4319 tree temp = NULL_TREE;
4320 for (ix = 0;
4321 VEC_iterate (constructor_elt, CONSTRUCTOR_ELTS (*expr_p),
4322 ix, ce);
4323 ix++)
4324 if (TREE_SIDE_EFFECTS (ce->value))
4325 append_to_statement_list (ce->value, &temp);
4326
4327 *expr_p = temp;
4328 ret = GS_OK;
4329 }
4330 /* C99 code may assign to an array in a constructed
4331 structure or union, and this has undefined behavior only
4332 on execution, so create a temporary if an lvalue is
4333 required. */
4334 else if (fallback == fb_lvalue)
4335 {
4336 *expr_p = get_initialized_tmp_var (*expr_p, pre_p, post_p);
4337 lang_hooks.mark_addressable (*expr_p);
4338 }
4339 else
4340 ret = GS_ALL_DONE;
4341 break;
4342
4343 /* The following are special cases that are not handled by the
4344 original GIMPLE grammar. */
4345
4346 /* SAVE_EXPR nodes are converted into a GIMPLE identifier and
4347 eliminated. */
4348 case SAVE_EXPR:
4349 ret = gimplify_save_expr (expr_p, pre_p, post_p);
4350 break;
4351
4352 case BIT_FIELD_REF:
4353 {
4354 enum gimplify_status r0, r1, r2;
4355
4356 r0 = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p, post_p,
4357 is_gimple_lvalue, fb_either);
4358 r1 = gimplify_expr (&TREE_OPERAND (*expr_p, 1), pre_p, post_p,
4359 is_gimple_val, fb_rvalue);
4360 r2 = gimplify_expr (&TREE_OPERAND (*expr_p, 2), pre_p, post_p,
4361 is_gimple_val, fb_rvalue);
4362 recalculate_side_effects (*expr_p);
4363
4364 ret = MIN (r0, MIN (r1, r2));
4365 }
4366 break;
4367
4368 case NON_LVALUE_EXPR:
4369 /* This should have been stripped above. */
4370 gcc_unreachable ();
4371
4372 case ASM_EXPR:
4373 ret = gimplify_asm_expr (expr_p, pre_p, post_p);
4374 break;
4375
4376 case TRY_FINALLY_EXPR:
4377 case TRY_CATCH_EXPR:
4378 gimplify_to_stmt_list (&TREE_OPERAND (*expr_p, 0));
4379 gimplify_to_stmt_list (&TREE_OPERAND (*expr_p, 1));
4380 ret = GS_ALL_DONE;
4381 break;
4382
4383 case CLEANUP_POINT_EXPR:
4384 ret = gimplify_cleanup_point_expr (expr_p, pre_p);
4385 break;
4386
4387 case TARGET_EXPR:
4388 ret = gimplify_target_expr (expr_p, pre_p, post_p);
4389 break;
4390
4391 case CATCH_EXPR:
4392 gimplify_to_stmt_list (&CATCH_BODY (*expr_p));
4393 ret = GS_ALL_DONE;
4394 break;
4395
4396 case EH_FILTER_EXPR:
4397 gimplify_to_stmt_list (&EH_FILTER_FAILURE (*expr_p));
4398 ret = GS_ALL_DONE;
4399 break;
4400
4401 case OBJ_TYPE_REF:
4402 {
4403 enum gimplify_status r0, r1;
4404 r0 = gimplify_expr (&OBJ_TYPE_REF_OBJECT (*expr_p), pre_p, post_p,
4405 is_gimple_val, fb_rvalue);
4406 r1 = gimplify_expr (&OBJ_TYPE_REF_EXPR (*expr_p), pre_p, post_p,
4407 is_gimple_val, fb_rvalue);
4408 ret = MIN (r0, r1);
4409 }
4410 break;
4411
4412 case LABEL_DECL:
4413 /* We get here when taking the address of a label. We mark
4414 the label as "forced"; meaning it can never be removed and
4415 it is a potential target for any computed goto. */
4416 FORCED_LABEL (*expr_p) = 1;
4417 ret = GS_ALL_DONE;
4418 break;
4419
4420 case STATEMENT_LIST:
4421 ret = gimplify_statement_list (expr_p);
4422 break;
4423
4424 case WITH_SIZE_EXPR:
4425 {
4426 gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p,
4427 post_p == &internal_post ? NULL : post_p,
4428 gimple_test_f, fallback);
4429 gimplify_expr (&TREE_OPERAND (*expr_p, 1), pre_p, post_p,
4430 is_gimple_val, fb_rvalue);
4431 }
4432 break;
4433
4434 case VAR_DECL:
4435 case PARM_DECL:
4436 ret = gimplify_var_or_parm_decl (expr_p);
4437 break;
4438
4439 case SSA_NAME:
4440 /* Allow callbacks into the gimplifier during optimization. */
4441 ret = GS_ALL_DONE;
4442 break;
4443
4444 default:
4445 switch (TREE_CODE_CLASS (TREE_CODE (*expr_p)))
4446 {
4447 case tcc_comparison:
4448 /* If this is a comparison of objects of aggregate type,
4449 handle it specially (by converting to a call to
4450 memcmp). It would be nice to only have to do this
4451 for variable-sized objects, but then we'd have to
4452 allow the same nest of reference nodes we allow for
4453 MODIFY_EXPR and that's too complex. */
4454 if (!AGGREGATE_TYPE_P (TREE_TYPE (TREE_OPERAND (*expr_p, 1))))
4455 goto expr_2;
4456 ret = gimplify_variable_sized_compare (expr_p);
4457 break;
4458
4459 /* If *EXPR_P does not need to be special-cased, handle it
4460 according to its class. */
4461 case tcc_unary:
4462 ret = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p,
4463 post_p, is_gimple_val, fb_rvalue);
4464 break;
4465
4466 case tcc_binary:
4467 expr_2:
4468 {
4469 enum gimplify_status r0, r1;
4470
4471 r0 = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p,
4472 post_p, is_gimple_val, fb_rvalue);
4473 r1 = gimplify_expr (&TREE_OPERAND (*expr_p, 1), pre_p,
4474 post_p, is_gimple_val, fb_rvalue);
4475
4476 ret = MIN (r0, r1);
4477 break;
4478 }
4479
4480 case tcc_declaration:
4481 case tcc_constant:
4482 ret = GS_ALL_DONE;
4483 goto dont_recalculate;
4484
4485 default:
4486 gcc_assert (TREE_CODE (*expr_p) == TRUTH_AND_EXPR
4487 || TREE_CODE (*expr_p) == TRUTH_OR_EXPR
4488 || TREE_CODE (*expr_p) == TRUTH_XOR_EXPR);
4489 goto expr_2;
4490 }
4491
4492 recalculate_side_effects (*expr_p);
4493 dont_recalculate:
4494 break;
4495 }
4496
4497 /* If we replaced *expr_p, gimplify again. */
4498 if (ret == GS_OK && (*expr_p == NULL || *expr_p == save_expr))
4499 ret = GS_ALL_DONE;
4500 }
4501 while (ret == GS_OK);
4502
4503 /* If we encountered an error_mark somewhere nested inside, either
4504 stub out the statement or propagate the error back out. */
4505 if (ret == GS_ERROR)
4506 {
4507 if (is_statement)
4508 *expr_p = NULL;
4509 goto out;
4510 }
4511
4512 /* This was only valid as a return value from the langhook, which
4513 we handled. Make sure it doesn't escape from any other context. */
4514 gcc_assert (ret != GS_UNHANDLED);
4515
4516 if (fallback == fb_none && *expr_p && !is_gimple_stmt (*expr_p))
4517 {
4518 /* We aren't looking for a value, and we don't have a valid
4519 statement. If it doesn't have side-effects, throw it away. */
4520 if (!TREE_SIDE_EFFECTS (*expr_p))
4521 *expr_p = NULL;
4522 else if (!TREE_THIS_VOLATILE (*expr_p))
4523 {
4524 /* This is probably a _REF that contains something nested that
4525 has side effects. Recurse through the operands to find it. */
4526 enum tree_code code = TREE_CODE (*expr_p);
4527
4528 switch (code)
4529 {
4530 case COMPONENT_REF:
4531 case REALPART_EXPR: case IMAGPART_EXPR:
4532 gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p, post_p,
4533 gimple_test_f, fallback);
4534 break;
4535
4536 case ARRAY_REF: case ARRAY_RANGE_REF:
4537 gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p, post_p,
4538 gimple_test_f, fallback);
4539 gimplify_expr (&TREE_OPERAND (*expr_p, 1), pre_p, post_p,
4540 gimple_test_f, fallback);
4541 break;
4542
4543 default:
4544 /* Anything else with side-effects must be converted to
4545 a valid statement before we get here. */
4546 gcc_unreachable ();
4547 }
4548
4549 *expr_p = NULL;
4550 }
4551 else if (COMPLETE_TYPE_P (TREE_TYPE (*expr_p)))
4552 {
4553 /* Historically, the compiler has treated a bare
4554 reference to a volatile lvalue as forcing a load. */
4555 tree type = TYPE_MAIN_VARIANT (TREE_TYPE (*expr_p));
4556 /* Normally, we do want to create a temporary for a
4557 TREE_ADDRESSABLE type because such a type should not be
4558 copied by bitwise-assignment. However, we make an
4559 exception here, as all we are doing here is ensuring that
4560 we read the bytes that make up the type. We use
4561 create_tmp_var_raw because create_tmp_var will abort when
4562 given a TREE_ADDRESSABLE type. */
4563 tree tmp = create_tmp_var_raw (type, "vol");
4564 gimple_add_tmp_var (tmp);
4565 *expr_p = build2 (MODIFY_EXPR, type, tmp, *expr_p);
4566 }
4567 else
4568 /* We can't do anything useful with a volatile reference to
4569 incomplete type, so just throw it away. */
4570 *expr_p = NULL;
4571 }
4572
4573 /* If we are gimplifying at the statement level, we're done. Tack
4574 everything together and replace the original statement with the
4575 gimplified form. */
4576 if (fallback == fb_none || is_statement)
4577 {
4578 if (internal_pre || internal_post)
4579 {
4580 append_to_statement_list (*expr_p, &internal_pre);
4581 append_to_statement_list (internal_post, &internal_pre);
4582 annotate_all_with_locus (&internal_pre, input_location);
4583 *expr_p = internal_pre;
4584 }
4585 else if (!*expr_p)
4586 ;
4587 else if (TREE_CODE (*expr_p) == STATEMENT_LIST)
4588 annotate_all_with_locus (expr_p, input_location);
4589 else
4590 annotate_one_with_locus (*expr_p, input_location);
4591 goto out;
4592 }
4593
4594 /* Otherwise we're gimplifying a subexpression, so the resulting value is
4595 interesting. */
4596
4597 /* If it's sufficiently simple already, we're done. Unless we are
4598 handling some post-effects internally; if that's the case, we need to
4599 copy into a temp before adding the post-effects to the tree. */
4600 if (!internal_post && (*gimple_test_f) (*expr_p))
4601 goto out;
4602
4603 /* Otherwise, we need to create a new temporary for the gimplified
4604 expression. */
4605
4606 /* We can't return an lvalue if we have an internal postqueue. The
4607 object the lvalue refers to would (probably) be modified by the
4608 postqueue; we need to copy the value out first, which means an
4609 rvalue. */
4610 if ((fallback & fb_lvalue) && !internal_post
4611 && is_gimple_addressable (*expr_p))
4612 {
4613 /* An lvalue will do. Take the address of the expression, store it
4614 in a temporary, and replace the expression with an INDIRECT_REF of
4615 that temporary. */
4616 tmp = build_fold_addr_expr (*expr_p);
4617 gimplify_expr (&tmp, pre_p, post_p, is_gimple_reg, fb_rvalue);
4618 *expr_p = build1 (INDIRECT_REF, TREE_TYPE (TREE_TYPE (tmp)), tmp);
4619 }
4620 else if ((fallback & fb_rvalue) && is_gimple_formal_tmp_rhs (*expr_p))
4621 {
4622 gcc_assert (!VOID_TYPE_P (TREE_TYPE (*expr_p)));
4623
4624 /* An rvalue will do. Assign the gimplified expression into a new
4625 temporary TMP and replace the original expression with TMP. */
4626
4627 if (internal_post || (fallback & fb_lvalue))
4628 /* The postqueue might change the value of the expression between
4629 the initialization and use of the temporary, so we can't use a
4630 formal temp. FIXME do we care? */
4631 *expr_p = get_initialized_tmp_var (*expr_p, pre_p, post_p);
4632 else
4633 *expr_p = get_formal_tmp_var (*expr_p, pre_p);
4634
4635 if (TREE_CODE (*expr_p) != SSA_NAME)
4636 DECL_GIMPLE_FORMAL_TEMP_P (*expr_p) = 1;
4637 }
4638 else
4639 {
4640 #ifdef ENABLE_CHECKING
4641 if (!(fallback & fb_mayfail))
4642 {
4643 fprintf (stderr, "gimplification failed:\n");
4644 print_generic_expr (stderr, *expr_p, 0);
4645 debug_tree (*expr_p);
4646 internal_error ("gimplification failed");
4647 }
4648 #endif
4649 gcc_assert (fallback & fb_mayfail);
4650 /* If this is an asm statement, and the user asked for the
4651 impossible, don't die. Fail and let gimplify_asm_expr
4652 issue an error. */
4653 ret = GS_ERROR;
4654 goto out;
4655 }
4656
4657 /* Make sure the temporary matches our predicate. */
4658 gcc_assert ((*gimple_test_f) (*expr_p));
4659
4660 if (internal_post)
4661 {
4662 annotate_all_with_locus (&internal_post, input_location);
4663 append_to_statement_list (internal_post, pre_p);
4664 }
4665
4666 out:
4667 input_location = saved_location;
4668 return ret;
4669 }
4670
4671 /* Look through TYPE for variable-sized objects and gimplify each such
4672 size that we find. Add to LIST_P any statements generated. */
4673
4674 void
4675 gimplify_type_sizes (tree type, tree *list_p)
4676 {
4677 tree field, t;
4678
4679 if (type == NULL || type == error_mark_node)
4680 return;
4681
4682 /* We first do the main variant, then copy into any other variants. */
4683 type = TYPE_MAIN_VARIANT (type);
4684
4685 /* Avoid infinite recursion. */
4686 if (TYPE_SIZES_GIMPLIFIED (type))
4687 return;
4688
4689 TYPE_SIZES_GIMPLIFIED (type) = 1;
4690
4691 switch (TREE_CODE (type))
4692 {
4693 case INTEGER_TYPE:
4694 case ENUMERAL_TYPE:
4695 case BOOLEAN_TYPE:
4696 case CHAR_TYPE:
4697 case REAL_TYPE:
4698 gimplify_one_sizepos (&TYPE_MIN_VALUE (type), list_p);
4699 gimplify_one_sizepos (&TYPE_MAX_VALUE (type), list_p);
4700
4701 for (t = TYPE_NEXT_VARIANT (type); t; t = TYPE_NEXT_VARIANT (t))
4702 {
4703 TYPE_MIN_VALUE (t) = TYPE_MIN_VALUE (type);
4704 TYPE_MAX_VALUE (t) = TYPE_MAX_VALUE (type);
4705 }
4706 break;
4707
4708 case ARRAY_TYPE:
4709 /* These types may not have declarations, so handle them here. */
4710 gimplify_type_sizes (TREE_TYPE (type), list_p);
4711 gimplify_type_sizes (TYPE_DOMAIN (type), list_p);
4712 break;
4713
4714 case RECORD_TYPE:
4715 case UNION_TYPE:
4716 case QUAL_UNION_TYPE:
4717 for (field = TYPE_FIELDS (type); field; field = TREE_CHAIN (field))
4718 if (TREE_CODE (field) == FIELD_DECL)
4719 {
4720 gimplify_one_sizepos (&DECL_FIELD_OFFSET (field), list_p);
4721 gimplify_type_sizes (TREE_TYPE (field), list_p);
4722 }
4723 break;
4724
4725 case POINTER_TYPE:
4726 case REFERENCE_TYPE:
4727 gimplify_type_sizes (TREE_TYPE (type), list_p);
4728 break;
4729
4730 default:
4731 break;
4732 }
4733
4734 gimplify_one_sizepos (&TYPE_SIZE (type), list_p);
4735 gimplify_one_sizepos (&TYPE_SIZE_UNIT (type), list_p);
4736
4737 for (t = TYPE_NEXT_VARIANT (type); t; t = TYPE_NEXT_VARIANT (t))
4738 {
4739 TYPE_SIZE (t) = TYPE_SIZE (type);
4740 TYPE_SIZE_UNIT (t) = TYPE_SIZE_UNIT (type);
4741 TYPE_SIZES_GIMPLIFIED (t) = 1;
4742 }
4743 }
4744
4745 /* A subroutine of gimplify_type_sizes to make sure that *EXPR_P,
4746 a size or position, has had all of its SAVE_EXPRs evaluated.
4747 We add any required statements to STMT_P. */
4748
4749 void
4750 gimplify_one_sizepos (tree *expr_p, tree *stmt_p)
4751 {
4752 tree type, expr = *expr_p;
4753
4754 /* We don't do anything if the value isn't there, is constant, or contains
4755 A PLACEHOLDER_EXPR. We also don't want to do anything if it's already
4756 a VAR_DECL. If it's a VAR_DECL from another function, the gimplifier
4757 will want to replace it with a new variable, but that will cause problems
4758 if this type is from outside the function. It's OK to have that here. */
4759 if (expr == NULL_TREE || TREE_CONSTANT (expr)
4760 || TREE_CODE (expr) == VAR_DECL
4761 || CONTAINS_PLACEHOLDER_P (expr))
4762 return;
4763
4764 type = TREE_TYPE (expr);
4765 *expr_p = unshare_expr (expr);
4766
4767 gimplify_expr (expr_p, stmt_p, NULL, is_gimple_val, fb_rvalue);
4768 expr = *expr_p;
4769
4770 /* Verify that we've an exact type match with the original expression.
4771 In particular, we do not wish to drop a "sizetype" in favour of a
4772 type of similar dimensions. We don't want to pollute the generic
4773 type-stripping code with this knowledge because it doesn't matter
4774 for the bulk of GENERIC/GIMPLE. It only matters that TYPE_SIZE_UNIT
4775 and friends retain their "sizetype-ness". */
4776 if (TREE_TYPE (expr) != type
4777 && TREE_CODE (type) == INTEGER_TYPE
4778 && TYPE_IS_SIZETYPE (type))
4779 {
4780 tree tmp;
4781
4782 *expr_p = create_tmp_var (type, NULL);
4783 tmp = build1 (NOP_EXPR, type, expr);
4784 tmp = build2 (MODIFY_EXPR, type, *expr_p, expr);
4785 if (EXPR_HAS_LOCATION (expr))
4786 SET_EXPR_LOCUS (tmp, EXPR_LOCUS (expr));
4787 else
4788 SET_EXPR_LOCATION (tmp, input_location);
4789
4790 gimplify_and_add (tmp, stmt_p);
4791 }
4792 }
4793 \f
4794 #ifdef ENABLE_CHECKING
4795 /* Compare types A and B for a "close enough" match. */
4796
4797 static bool
4798 cpt_same_type (tree a, tree b)
4799 {
4800 if (lang_hooks.types_compatible_p (a, b))
4801 return true;
4802
4803 /* ??? The C++ FE decomposes METHOD_TYPES to FUNCTION_TYPES and doesn't
4804 link them together. This routine is intended to catch type errors
4805 that will affect the optimizers, and the optimizers don't add new
4806 dereferences of function pointers, so ignore it. */
4807 if ((TREE_CODE (a) == FUNCTION_TYPE || TREE_CODE (a) == METHOD_TYPE)
4808 && (TREE_CODE (b) == FUNCTION_TYPE || TREE_CODE (b) == METHOD_TYPE))
4809 return true;
4810
4811 /* ??? The C FE pushes type qualifiers after the fact into the type of
4812 the element from the type of the array. See build_unary_op's handling
4813 of ADDR_EXPR. This seems wrong -- if we were going to do this, we
4814 should have done it when creating the variable in the first place.
4815 Alternately, why aren't the two array types made variants? */
4816 if (TREE_CODE (a) == ARRAY_TYPE && TREE_CODE (b) == ARRAY_TYPE)
4817 return cpt_same_type (TREE_TYPE (a), TREE_TYPE (b));
4818
4819 /* And because of those, we have to recurse down through pointers. */
4820 if (POINTER_TYPE_P (a) && POINTER_TYPE_P (b))
4821 return cpt_same_type (TREE_TYPE (a), TREE_TYPE (b));
4822
4823 return false;
4824 }
4825
4826 /* Check for some cases of the front end missing cast expressions.
4827 The type of a dereference should correspond to the pointer type;
4828 similarly the type of an address should match its object. */
4829
4830 static tree
4831 check_pointer_types_r (tree *tp, int *walk_subtrees ATTRIBUTE_UNUSED,
4832 void *data ATTRIBUTE_UNUSED)
4833 {
4834 tree t = *tp;
4835 tree ptype, otype, dtype;
4836
4837 switch (TREE_CODE (t))
4838 {
4839 case INDIRECT_REF:
4840 case ARRAY_REF:
4841 otype = TREE_TYPE (t);
4842 ptype = TREE_TYPE (TREE_OPERAND (t, 0));
4843 dtype = TREE_TYPE (ptype);
4844 gcc_assert (cpt_same_type (otype, dtype));
4845 break;
4846
4847 case ADDR_EXPR:
4848 ptype = TREE_TYPE (t);
4849 otype = TREE_TYPE (TREE_OPERAND (t, 0));
4850 dtype = TREE_TYPE (ptype);
4851 if (!cpt_same_type (otype, dtype))
4852 {
4853 /* &array is allowed to produce a pointer to the element, rather than
4854 a pointer to the array type. We must allow this in order to
4855 properly represent assigning the address of an array in C into
4856 pointer to the element type. */
4857 gcc_assert (TREE_CODE (otype) == ARRAY_TYPE
4858 && POINTER_TYPE_P (ptype)
4859 && cpt_same_type (TREE_TYPE (otype), dtype));
4860 break;
4861 }
4862 break;
4863
4864 default:
4865 return NULL_TREE;
4866 }
4867
4868
4869 return NULL_TREE;
4870 }
4871 #endif
4872
4873 /* Gimplify the body of statements pointed to by BODY_P. FNDECL is the
4874 function decl containing BODY. */
4875
4876 void
4877 gimplify_body (tree *body_p, tree fndecl, bool do_parms)
4878 {
4879 location_t saved_location = input_location;
4880 tree body, parm_stmts;
4881
4882 timevar_push (TV_TREE_GIMPLIFY);
4883 push_gimplify_context ();
4884
4885 /* Unshare most shared trees in the body and in that of any nested functions.
4886 It would seem we don't have to do this for nested functions because
4887 they are supposed to be output and then the outer function gimplified
4888 first, but the g++ front end doesn't always do it that way. */
4889 unshare_body (body_p, fndecl);
4890 unvisit_body (body_p, fndecl);
4891
4892 /* Make sure input_location isn't set to something wierd. */
4893 input_location = DECL_SOURCE_LOCATION (fndecl);
4894
4895 /* Resolve callee-copies. This has to be done before processing
4896 the body so that DECL_VALUE_EXPR gets processed correctly. */
4897 parm_stmts = do_parms ? gimplify_parameters () : NULL;
4898
4899 /* Gimplify the function's body. */
4900 gimplify_stmt (body_p);
4901 body = *body_p;
4902
4903 if (!body)
4904 body = alloc_stmt_list ();
4905 else if (TREE_CODE (body) == STATEMENT_LIST)
4906 {
4907 tree t = expr_only (*body_p);
4908 if (t)
4909 body = t;
4910 }
4911
4912 /* If there isn't an outer BIND_EXPR, add one. */
4913 if (TREE_CODE (body) != BIND_EXPR)
4914 {
4915 tree b = build3 (BIND_EXPR, void_type_node, NULL_TREE,
4916 NULL_TREE, NULL_TREE);
4917 TREE_SIDE_EFFECTS (b) = 1;
4918 append_to_statement_list_force (body, &BIND_EXPR_BODY (b));
4919 body = b;
4920 }
4921
4922 /* If we had callee-copies statements, insert them at the beginning
4923 of the function. */
4924 if (parm_stmts)
4925 {
4926 append_to_statement_list_force (BIND_EXPR_BODY (body), &parm_stmts);
4927 BIND_EXPR_BODY (body) = parm_stmts;
4928 }
4929
4930 /* Unshare again, in case gimplification was sloppy. */
4931 unshare_all_trees (body);
4932
4933 *body_p = body;
4934
4935 pop_gimplify_context (body);
4936
4937 #ifdef ENABLE_CHECKING
4938 walk_tree (body_p, check_pointer_types_r, NULL, NULL);
4939 #endif
4940
4941 timevar_pop (TV_TREE_GIMPLIFY);
4942 input_location = saved_location;
4943 }
4944
4945 /* Entry point to the gimplification pass. FNDECL is the FUNCTION_DECL
4946 node for the function we want to gimplify. */
4947
4948 void
4949 gimplify_function_tree (tree fndecl)
4950 {
4951 tree oldfn, parm, ret;
4952
4953 oldfn = current_function_decl;
4954 current_function_decl = fndecl;
4955 cfun = DECL_STRUCT_FUNCTION (fndecl);
4956 if (cfun == NULL)
4957 allocate_struct_function (fndecl);
4958
4959 for (parm = DECL_ARGUMENTS (fndecl); parm ; parm = TREE_CHAIN (parm))
4960 {
4961 /* Preliminarily mark non-addressed complex variables as eligible
4962 for promotion to gimple registers. We'll transform their uses
4963 as we find them. */
4964 if (TREE_CODE (TREE_TYPE (parm)) == COMPLEX_TYPE
4965 && !TREE_THIS_VOLATILE (parm)
4966 && !needs_to_live_in_memory (parm))
4967 DECL_COMPLEX_GIMPLE_REG_P (parm) = 1;
4968 }
4969
4970 ret = DECL_RESULT (fndecl);
4971 if (TREE_CODE (TREE_TYPE (ret)) == COMPLEX_TYPE
4972 && !needs_to_live_in_memory (ret))
4973 DECL_COMPLEX_GIMPLE_REG_P (ret) = 1;
4974
4975 gimplify_body (&DECL_SAVED_TREE (fndecl), fndecl, true);
4976
4977 /* If we're instrumenting function entry/exit, then prepend the call to
4978 the entry hook and wrap the whole function in a TRY_FINALLY_EXPR to
4979 catch the exit hook. */
4980 /* ??? Add some way to ignore exceptions for this TFE. */
4981 if (flag_instrument_function_entry_exit
4982 && ! DECL_NO_INSTRUMENT_FUNCTION_ENTRY_EXIT (fndecl))
4983 {
4984 tree tf, x, bind;
4985
4986 tf = build2 (TRY_FINALLY_EXPR, void_type_node, NULL, NULL);
4987 TREE_SIDE_EFFECTS (tf) = 1;
4988 x = DECL_SAVED_TREE (fndecl);
4989 append_to_statement_list (x, &TREE_OPERAND (tf, 0));
4990 x = implicit_built_in_decls[BUILT_IN_PROFILE_FUNC_EXIT];
4991 x = build_function_call_expr (x, NULL);
4992 append_to_statement_list (x, &TREE_OPERAND (tf, 1));
4993
4994 bind = build3 (BIND_EXPR, void_type_node, NULL, NULL, NULL);
4995 TREE_SIDE_EFFECTS (bind) = 1;
4996 x = implicit_built_in_decls[BUILT_IN_PROFILE_FUNC_ENTER];
4997 x = build_function_call_expr (x, NULL);
4998 append_to_statement_list (x, &BIND_EXPR_BODY (bind));
4999 append_to_statement_list (tf, &BIND_EXPR_BODY (bind));
5000
5001 DECL_SAVED_TREE (fndecl) = bind;
5002 }
5003
5004 current_function_decl = oldfn;
5005 cfun = oldfn ? DECL_STRUCT_FUNCTION (oldfn) : NULL;
5006 }
5007
5008 \f
5009 /* Expands EXPR to list of gimple statements STMTS. If SIMPLE is true,
5010 force the result to be either ssa_name or an invariant, otherwise
5011 just force it to be a rhs expression. If VAR is not NULL, make the
5012 base variable of the final destination be VAR if suitable. */
5013
5014 tree
5015 force_gimple_operand (tree expr, tree *stmts, bool simple, tree var)
5016 {
5017 tree t;
5018 enum gimplify_status ret;
5019 gimple_predicate gimple_test_f;
5020
5021 *stmts = NULL_TREE;
5022
5023 if (is_gimple_val (expr))
5024 return expr;
5025
5026 gimple_test_f = simple ? is_gimple_val : is_gimple_reg_rhs;
5027
5028 push_gimplify_context ();
5029 gimplify_ctxp->into_ssa = in_ssa_p;
5030
5031 if (var)
5032 expr = build2 (MODIFY_EXPR, TREE_TYPE (var), var, expr);
5033
5034 ret = gimplify_expr (&expr, stmts, NULL,
5035 gimple_test_f, fb_rvalue);
5036 gcc_assert (ret != GS_ERROR);
5037
5038 if (referenced_vars)
5039 {
5040 for (t = gimplify_ctxp->temps; t ; t = TREE_CHAIN (t))
5041 add_referenced_tmp_var (t);
5042 }
5043
5044 pop_gimplify_context (NULL);
5045
5046 return expr;
5047 }
5048
5049 /* Invokes force_gimple_operand for EXPR with parameters SIMPLE_P and VAR. If
5050 some statements are produced, emits them before BSI. */
5051
5052 tree
5053 force_gimple_operand_bsi (block_stmt_iterator *bsi, tree expr,
5054 bool simple_p, tree var)
5055 {
5056 tree stmts;
5057
5058 expr = force_gimple_operand (expr, &stmts, simple_p, var);
5059 if (stmts)
5060 bsi_insert_before (bsi, stmts, BSI_SAME_STMT);
5061
5062 return expr;
5063 }
5064
5065 #include "gt-gimplify.h"