2005-05-13 Josh Conner <jconner@apple.com>
[official-gcc.git] / gcc / gimplify.c
blob1b91b186d6e8af27a77463f2ffd0b34996374c2c
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>.
7 This file is part of GCC.
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.
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.
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, 59 Temple Place - Suite 330, Boston, MA
22 02111-1307, USA. */
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 "errors.h"
31 #include "varray.h"
32 #include "tree-gimple.h"
33 #include "tree-inline.h"
34 #include "diagnostic.h"
35 #include "langhooks.h"
36 #include "langhooks-def.h"
37 #include "tree-flow.h"
38 #include "cgraph.h"
39 #include "timevar.h"
40 #include "except.h"
41 #include "hashtab.h"
42 #include "flags.h"
43 #include "real.h"
44 #include "function.h"
45 #include "output.h"
46 #include "expr.h"
47 #include "ggc.h"
48 #include "target.h"
50 static struct gimplify_ctx
52 tree current_bind_expr;
53 tree temps;
54 tree conditional_cleanups;
55 tree exit_label;
56 tree return_temp;
57 varray_type 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;
66 /* Formal (expression) temporary table handling: Multiple occurrences of
67 the same scalar expression are evaluated into the same temporary. */
69 typedef struct gimple_temp_hash_elt
71 tree val; /* Key */
72 tree temp; /* Value */
73 } elt_t;
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
82 /* Return a hash value for a formal temporary table entry. */
84 static hashval_t
85 gimple_tree_hash (const void *p)
87 tree t = ((const elt_t *) p)->val;
88 return iterative_hash_expr (t, 0);
91 /* Compare two formal temporary table entries. */
93 static int
94 gimple_tree_eq (const void *p1, const void *p2)
96 tree t1 = ((const elt_t *) p1)->val;
97 tree t2 = ((const elt_t *) p2)->val;
98 enum tree_code code = TREE_CODE (t1);
100 if (TREE_CODE (t2) != code
101 || TREE_TYPE (t1) != TREE_TYPE (t2))
102 return 0;
104 if (!operand_equal_p (t1, t2, 0))
105 return 0;
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));
111 return 1;
114 /* Set up a context for the gimplifier. */
116 void
117 push_gimplify_context (void)
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;
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. */
133 void
134 pop_gimplify_context (tree body)
136 tree t;
138 gcc_assert (gimplify_ctxp && !gimplify_ctxp->current_bind_expr);
140 for (t = gimplify_ctxp->temps; t ; t = TREE_CHAIN (t))
141 DECL_GIMPLE_FORMAL_TEMP_P (t) = 0;
143 if (body)
144 declare_tmp_vars (gimplify_ctxp->temps, body);
145 else
146 record_vars (gimplify_ctxp->temps);
148 #if 0
149 if (!quiet_flag && optimize)
150 fprintf (stderr, " collisions: %f ",
151 htab_collisions (gimplify_ctxp->temp_htab));
152 #endif
154 if (optimize)
155 htab_delete (gimplify_ctxp->temp_htab);
156 free (gimplify_ctxp);
157 gimplify_ctxp = NULL;
160 static void
161 gimple_push_bind_expr (tree bind)
163 TREE_CHAIN (bind) = gimplify_ctxp->current_bind_expr;
164 gimplify_ctxp->current_bind_expr = bind;
167 static void
168 gimple_pop_bind_expr (void)
170 gimplify_ctxp->current_bind_expr
171 = TREE_CHAIN (gimplify_ctxp->current_bind_expr);
174 tree
175 gimple_current_bind_expr (void)
177 return gimplify_ctxp->current_bind_expr;
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. */
183 static bool
184 gimple_conditional_context (void)
186 return gimplify_ctxp->conditions > 0;
189 /* Note that we've entered a COND_EXPR. */
191 static void
192 gimple_push_condition (void)
194 #ifdef ENABLE_CHECKING
195 if (gimplify_ctxp->conditions == 0)
196 gcc_assert (!gimplify_ctxp->conditional_cleanups);
197 #endif
198 ++(gimplify_ctxp->conditions);
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. */
204 static void
205 gimple_pop_condition (tree *pre_p)
207 int conds = --(gimplify_ctxp->conditions);
209 gcc_assert (conds >= 0);
210 if (conds == 0)
212 append_to_statement_list (gimplify_ctxp->conditional_cleanups, pre_p);
213 gimplify_ctxp->conditional_cleanups = NULL_TREE;
217 /* A subroutine of append_to_statement_list{,_force}. T is not NULL. */
219 static void
220 append_to_statement_list_1 (tree t, tree *list_p)
222 tree list = *list_p;
223 tree_stmt_iterator i;
225 if (!list)
227 if (t && TREE_CODE (t) == STATEMENT_LIST)
229 *list_p = t;
230 return;
232 *list_p = list = alloc_stmt_list ();
235 i = tsi_last (list);
236 tsi_link_after (&i, t, TSI_CONTINUE_LINKING);
239 /* Add T to the end of the list container pointed by LIST_P.
240 If T is an expression with no effects, it is ignored. */
242 void
243 append_to_statement_list (tree t, tree *list_p)
245 if (t && TREE_SIDE_EFFECTS (t))
246 append_to_statement_list_1 (t, list_p);
249 /* Similar, but the statement is always added, regardless of side effects. */
251 void
252 append_to_statement_list_force (tree t, tree *list_p)
254 if (t != NULL_TREE)
255 append_to_statement_list_1 (t, list_p);
258 /* Both gimplify the statement T and append it to LIST_P. */
260 void
261 gimplify_and_add (tree t, tree *list_p)
263 gimplify_stmt (&t);
264 append_to_statement_list (t, list_p);
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".) */
272 static inline void
273 remove_suffix (char *name, int len)
275 int i;
277 for (i = 2; i < 8 && len > i; i++)
279 if (name[len - i] == '.')
281 name[len - i] = '\0';
282 break;
287 /* Create a nameless artificial label and put it in the current function
288 context. Returns the newly created label. */
290 tree
291 create_artificial_label (void)
293 tree lab = build_decl (LABEL_DECL, NULL_TREE, void_type_node);
295 DECL_ARTIFICIAL (lab) = 1;
296 DECL_IGNORED_P (lab) = 1;
297 DECL_CONTEXT (lab) = current_function_decl;
298 return lab;
301 /* Create a new temporary name with PREFIX. Returns an identifier. */
303 static GTY(()) unsigned int tmp_var_id_num;
305 tree
306 create_tmp_var_name (const char *prefix)
308 char *tmp_name;
310 if (prefix)
312 char *preftmp = ASTRDUP (prefix);
314 remove_suffix (preftmp, strlen (preftmp));
315 prefix = preftmp;
318 ASM_FORMAT_PRIVATE_NAME (tmp_name, prefix ? prefix : "T", tmp_var_id_num++);
319 return get_identifier (tmp_name);
323 /* Create a new temporary variable declaration of type TYPE.
324 Does NOT push it into the current binding. */
326 tree
327 create_tmp_var_raw (tree type, const char *prefix)
329 tree tmp_var;
330 tree new_type;
332 /* Make the type of the variable writable. */
333 new_type = build_type_variant (type, 0, 0);
334 TYPE_ATTRIBUTES (new_type) = TYPE_ATTRIBUTES (type);
336 tmp_var = build_decl (VAR_DECL, prefix ? create_tmp_var_name (prefix) : NULL,
337 type);
339 /* The variable was declared by the compiler. */
340 DECL_ARTIFICIAL (tmp_var) = 1;
341 /* And we don't want debug info for it. */
342 DECL_IGNORED_P (tmp_var) = 1;
344 /* Make the variable writable. */
345 TREE_READONLY (tmp_var) = 0;
347 DECL_EXTERNAL (tmp_var) = 0;
348 TREE_STATIC (tmp_var) = 0;
349 TREE_USED (tmp_var) = 1;
351 return tmp_var;
354 /* Create a new temporary variable declaration of type TYPE. DOES push the
355 variable into the current binding. Further, assume that this is called
356 only from gimplification or optimization, at which point the creation of
357 certain types are bugs. */
359 tree
360 create_tmp_var (tree type, const char *prefix)
362 tree tmp_var;
364 /* We don't allow types that are addressable (meaning we can't make copies),
365 incomplete, or of variable size. */
366 gcc_assert (!TREE_ADDRESSABLE (type)
367 && COMPLETE_TYPE_P (type)
368 && TREE_CODE (TYPE_SIZE_UNIT (type)) == INTEGER_CST);
370 tmp_var = create_tmp_var_raw (type, prefix);
371 gimple_add_tmp_var (tmp_var);
372 return tmp_var;
375 /* Given a tree, try to return a useful variable name that we can use
376 to prefix a temporary that is being assigned the value of the tree.
377 I.E. given <temp> = &A, return A. */
379 const char *
380 get_name (tree t)
382 tree stripped_decl;
384 stripped_decl = t;
385 STRIP_NOPS (stripped_decl);
386 if (DECL_P (stripped_decl) && DECL_NAME (stripped_decl))
387 return IDENTIFIER_POINTER (DECL_NAME (stripped_decl));
388 else
390 switch (TREE_CODE (stripped_decl))
392 case ADDR_EXPR:
393 return get_name (TREE_OPERAND (stripped_decl, 0));
394 break;
395 default:
396 return NULL;
401 /* Create a temporary with a name derived from VAL. Subroutine of
402 lookup_tmp_var; nobody else should call this function. */
404 static inline tree
405 create_tmp_from_val (tree val)
407 return create_tmp_var (TREE_TYPE (val), get_name (val));
410 /* Create a temporary to hold the value of VAL. If IS_FORMAL, try to reuse
411 an existing expression temporary. */
413 static tree
414 lookup_tmp_var (tree val, bool is_formal)
416 tree ret;
418 /* If not optimizing, never really reuse a temporary. local-alloc
419 won't allocate any variable that is used in more than one basic
420 block, which means it will go into memory, causing much extra
421 work in reload and final and poorer code generation, outweighing
422 the extra memory allocation here. */
423 if (!optimize || !is_formal || TREE_SIDE_EFFECTS (val))
424 ret = create_tmp_from_val (val);
425 else
427 elt_t elt, *elt_p;
428 void **slot;
430 elt.val = val;
431 slot = htab_find_slot (gimplify_ctxp->temp_htab, (void *)&elt, INSERT);
432 if (*slot == NULL)
434 elt_p = xmalloc (sizeof (*elt_p));
435 elt_p->val = val;
436 elt_p->temp = ret = create_tmp_from_val (val);
437 *slot = (void *) elt_p;
439 else
441 elt_p = (elt_t *) *slot;
442 ret = elt_p->temp;
446 if (is_formal)
447 DECL_GIMPLE_FORMAL_TEMP_P (ret) = 1;
449 return ret;
452 /* Returns a formal temporary variable initialized with VAL. PRE_P is as
453 in gimplify_expr. Only use this function if:
455 1) The value of the unfactored expression represented by VAL will not
456 change between the initialization and use of the temporary, and
457 2) The temporary will not be otherwise modified.
459 For instance, #1 means that this is inappropriate for SAVE_EXPR temps,
460 and #2 means it is inappropriate for && temps.
462 For other cases, use get_initialized_tmp_var instead. */
464 static tree
465 internal_get_tmp_var (tree val, tree *pre_p, tree *post_p, bool is_formal)
467 tree t, mod;
469 gimplify_expr (&val, pre_p, post_p, is_gimple_formal_tmp_rhs, fb_rvalue);
471 t = lookup_tmp_var (val, is_formal);
473 mod = build (MODIFY_EXPR, TREE_TYPE (t), t, val);
475 if (EXPR_HAS_LOCATION (val))
476 SET_EXPR_LOCUS (mod, EXPR_LOCUS (val));
477 else
478 SET_EXPR_LOCATION (mod, input_location);
480 /* gimplify_modify_expr might want to reduce this further. */
481 gimplify_and_add (mod, pre_p);
483 /* If we're gimplifying into ssa, gimplify_modify_expr will have
484 given our temporary an ssa name. Find and return it. */
485 if (gimplify_ctxp->into_ssa)
486 t = TREE_OPERAND (mod, 0);
488 return t;
491 tree
492 get_formal_tmp_var (tree val, tree *pre_p)
494 return internal_get_tmp_var (val, pre_p, NULL, true);
497 /* Returns a temporary variable initialized with VAL. PRE_P and POST_P
498 are as in gimplify_expr. */
500 tree
501 get_initialized_tmp_var (tree val, tree *pre_p, tree *post_p)
503 return internal_get_tmp_var (val, pre_p, post_p, false);
506 /* Declares all the variables in VARS in SCOPE. */
508 void
509 declare_tmp_vars (tree vars, tree scope)
511 tree last = vars;
512 if (last)
514 tree temps;
516 /* C99 mode puts the default 'return 0;' for main outside the outer
517 braces. So drill down until we find an actual scope. */
518 while (TREE_CODE (scope) == COMPOUND_EXPR)
519 scope = TREE_OPERAND (scope, 0);
521 gcc_assert (TREE_CODE (scope) == BIND_EXPR);
523 temps = nreverse (last);
524 TREE_CHAIN (last) = BIND_EXPR_VARS (scope);
525 BIND_EXPR_VARS (scope) = temps;
529 void
530 gimple_add_tmp_var (tree tmp)
532 gcc_assert (!TREE_CHAIN (tmp) && !DECL_SEEN_IN_BIND_EXPR_P (tmp));
534 DECL_CONTEXT (tmp) = current_function_decl;
535 DECL_SEEN_IN_BIND_EXPR_P (tmp) = 1;
537 if (gimplify_ctxp)
539 TREE_CHAIN (tmp) = gimplify_ctxp->temps;
540 gimplify_ctxp->temps = tmp;
542 else if (cfun)
543 record_vars (tmp);
544 else
545 declare_tmp_vars (tmp, DECL_SAVED_TREE (current_function_decl));
548 /* Determines whether to assign a locus to the statement STMT. */
550 static bool
551 should_carry_locus_p (tree stmt)
553 /* Don't emit a line note for a label. We particularly don't want to
554 emit one for the break label, since it doesn't actually correspond
555 to the beginning of the loop/switch. */
556 if (TREE_CODE (stmt) == LABEL_EXPR)
557 return false;
559 /* Do not annotate empty statements, since it confuses gcov. */
560 if (!TREE_SIDE_EFFECTS (stmt))
561 return false;
563 return true;
566 static void
567 annotate_one_with_locus (tree t, location_t locus)
569 if (EXPR_P (t) && ! EXPR_HAS_LOCATION (t) && should_carry_locus_p (t))
570 SET_EXPR_LOCATION (t, locus);
573 void
574 annotate_all_with_locus (tree *stmt_p, location_t locus)
576 tree_stmt_iterator i;
578 if (!*stmt_p)
579 return;
581 for (i = tsi_start (*stmt_p); !tsi_end_p (i); tsi_next (&i))
583 tree t = tsi_stmt (i);
585 /* Assuming we've already been gimplified, we shouldn't
586 see nested chaining constructs anymore. */
587 gcc_assert (TREE_CODE (t) != STATEMENT_LIST
588 && TREE_CODE (t) != COMPOUND_EXPR);
590 annotate_one_with_locus (t, locus);
594 /* Similar to copy_tree_r() but do not copy SAVE_EXPR or TARGET_EXPR nodes.
595 These nodes model computations that should only be done once. If we
596 were to unshare something like SAVE_EXPR(i++), the gimplification
597 process would create wrong code. */
599 static tree
600 mostly_copy_tree_r (tree *tp, int *walk_subtrees, void *data)
602 enum tree_code code = TREE_CODE (*tp);
603 /* Don't unshare types, decls, constants and SAVE_EXPR nodes. */
604 if (TREE_CODE_CLASS (code) == tcc_type
605 || TREE_CODE_CLASS (code) == tcc_declaration
606 || TREE_CODE_CLASS (code) == tcc_constant
607 || code == SAVE_EXPR || code == TARGET_EXPR
608 /* We can't do anything sensible with a BLOCK used as an expression,
609 but we also can't just die when we see it because of non-expression
610 uses. So just avert our eyes and cross our fingers. Silly Java. */
611 || code == BLOCK)
612 *walk_subtrees = 0;
613 else
615 gcc_assert (code != BIND_EXPR);
616 copy_tree_r (tp, walk_subtrees, data);
619 return NULL_TREE;
622 /* Callback for walk_tree to unshare most of the shared trees rooted at
623 *TP. If *TP has been visited already (i.e., TREE_VISITED (*TP) == 1),
624 then *TP is deep copied by calling copy_tree_r.
626 This unshares the same trees as copy_tree_r with the exception of
627 SAVE_EXPR nodes. These nodes model computations that should only be
628 done once. If we were to unshare something like SAVE_EXPR(i++), the
629 gimplification process would create wrong code. */
631 static tree
632 copy_if_shared_r (tree *tp, int *walk_subtrees ATTRIBUTE_UNUSED,
633 void *data ATTRIBUTE_UNUSED)
635 tree t = *tp;
636 enum tree_code code = TREE_CODE (t);
638 /* Skip types, decls, and constants. But we do want to look at their
639 types and the bounds of types. Mark them as visited so we properly
640 unmark their subtrees on the unmark pass. If we've already seen them,
641 don't look down further. */
642 if (TREE_CODE_CLASS (code) == tcc_type
643 || TREE_CODE_CLASS (code) == tcc_declaration
644 || TREE_CODE_CLASS (code) == tcc_constant)
646 if (TREE_VISITED (t))
647 *walk_subtrees = 0;
648 else
649 TREE_VISITED (t) = 1;
652 /* If this node has been visited already, unshare it and don't look
653 any deeper. */
654 else if (TREE_VISITED (t))
656 walk_tree (tp, mostly_copy_tree_r, NULL, NULL);
657 *walk_subtrees = 0;
660 /* Otherwise, mark the tree as visited and keep looking. */
661 else
662 TREE_VISITED (t) = 1;
664 return NULL_TREE;
667 static tree
668 unmark_visited_r (tree *tp, int *walk_subtrees ATTRIBUTE_UNUSED,
669 void *data ATTRIBUTE_UNUSED)
671 if (TREE_VISITED (*tp))
672 TREE_VISITED (*tp) = 0;
673 else
674 *walk_subtrees = 0;
676 return NULL_TREE;
679 /* Unshare all the trees in BODY_P, a pointer into the body of FNDECL, and the
680 bodies of any nested functions if we are unsharing the entire body of
681 FNDECL. */
683 static void
684 unshare_body (tree *body_p, tree fndecl)
686 struct cgraph_node *cgn = cgraph_node (fndecl);
688 walk_tree (body_p, copy_if_shared_r, NULL, NULL);
689 if (body_p == &DECL_SAVED_TREE (fndecl))
690 for (cgn = cgn->nested; cgn; cgn = cgn->next_nested)
691 unshare_body (&DECL_SAVED_TREE (cgn->decl), cgn->decl);
694 /* Likewise, but mark all trees as not visited. */
696 static void
697 unvisit_body (tree *body_p, tree fndecl)
699 struct cgraph_node *cgn = cgraph_node (fndecl);
701 walk_tree (body_p, unmark_visited_r, NULL, NULL);
702 if (body_p == &DECL_SAVED_TREE (fndecl))
703 for (cgn = cgn->nested; cgn; cgn = cgn->next_nested)
704 unvisit_body (&DECL_SAVED_TREE (cgn->decl), cgn->decl);
707 /* Unshare T and all the trees reached from T via TREE_CHAIN. */
709 static void
710 unshare_all_trees (tree t)
712 walk_tree (&t, copy_if_shared_r, NULL, NULL);
713 walk_tree (&t, unmark_visited_r, NULL, NULL);
716 /* Unconditionally make an unshared copy of EXPR. This is used when using
717 stored expressions which span multiple functions, such as BINFO_VTABLE,
718 as the normal unsharing process can't tell that they're shared. */
720 tree
721 unshare_expr (tree expr)
723 walk_tree (&expr, mostly_copy_tree_r, NULL, NULL);
724 return expr;
727 /* A terser interface for building a representation of an exception
728 specification. */
730 tree
731 gimple_build_eh_filter (tree body, tree allowed, tree failure)
733 tree t;
735 /* FIXME should the allowed types go in TREE_TYPE? */
736 t = build (EH_FILTER_EXPR, void_type_node, allowed, NULL_TREE);
737 append_to_statement_list (failure, &EH_FILTER_FAILURE (t));
739 t = build (TRY_CATCH_EXPR, void_type_node, NULL_TREE, t);
740 append_to_statement_list (body, &TREE_OPERAND (t, 0));
742 return t;
746 /* WRAPPER is a code such as BIND_EXPR or CLEANUP_POINT_EXPR which can both
747 contain statements and have a value. Assign its value to a temporary
748 and give it void_type_node. Returns the temporary, or NULL_TREE if
749 WRAPPER was already void. */
751 tree
752 voidify_wrapper_expr (tree wrapper, tree temp)
754 if (!VOID_TYPE_P (TREE_TYPE (wrapper)))
756 tree *p, sub = wrapper;
758 restart:
759 /* Set p to point to the body of the wrapper. */
760 switch (TREE_CODE (sub))
762 case BIND_EXPR:
763 /* For a BIND_EXPR, the body is operand 1. */
764 p = &BIND_EXPR_BODY (sub);
765 break;
767 default:
768 p = &TREE_OPERAND (sub, 0);
769 break;
772 /* Advance to the last statement. Set all container types to void. */
773 if (TREE_CODE (*p) == STATEMENT_LIST)
775 tree_stmt_iterator i = tsi_last (*p);
776 p = tsi_end_p (i) ? NULL : tsi_stmt_ptr (i);
778 else
780 for (; TREE_CODE (*p) == COMPOUND_EXPR; p = &TREE_OPERAND (*p, 1))
782 TREE_SIDE_EFFECTS (*p) = 1;
783 TREE_TYPE (*p) = void_type_node;
787 if (p == NULL || IS_EMPTY_STMT (*p))
789 /* Look through exception handling. */
790 else if (TREE_CODE (*p) == TRY_FINALLY_EXPR
791 || TREE_CODE (*p) == TRY_CATCH_EXPR)
793 sub = *p;
794 goto restart;
796 /* The C++ frontend already did this for us. */
797 else if (TREE_CODE (*p) == INIT_EXPR
798 || TREE_CODE (*p) == TARGET_EXPR)
799 temp = TREE_OPERAND (*p, 0);
800 /* If we're returning a dereference, move the dereference
801 outside the wrapper. */
802 else if (TREE_CODE (*p) == INDIRECT_REF)
804 tree ptr = TREE_OPERAND (*p, 0);
805 temp = create_tmp_var (TREE_TYPE (ptr), "retval");
806 *p = build (MODIFY_EXPR, TREE_TYPE (ptr), temp, ptr);
807 temp = build1 (INDIRECT_REF, TREE_TYPE (TREE_TYPE (temp)), temp);
808 /* If this is a BIND_EXPR for a const inline function, it might not
809 have TREE_SIDE_EFFECTS set. That is no longer accurate. */
810 TREE_SIDE_EFFECTS (wrapper) = 1;
812 else
814 if (!temp)
815 temp = create_tmp_var (TREE_TYPE (wrapper), "retval");
816 *p = build (MODIFY_EXPR, TREE_TYPE (temp), temp, *p);
817 TREE_SIDE_EFFECTS (wrapper) = 1;
820 TREE_TYPE (wrapper) = void_type_node;
821 return temp;
824 return NULL_TREE;
827 /* Prepare calls to builtins to SAVE and RESTORE the stack as well as
828 a temporary through which they communicate. */
830 static void
831 build_stack_save_restore (tree *save, tree *restore)
833 tree save_call, tmp_var;
835 save_call =
836 build_function_call_expr (implicit_built_in_decls[BUILT_IN_STACK_SAVE],
837 NULL_TREE);
838 tmp_var = create_tmp_var (ptr_type_node, "saved_stack");
840 *save = build (MODIFY_EXPR, ptr_type_node, tmp_var, save_call);
841 *restore =
842 build_function_call_expr (implicit_built_in_decls[BUILT_IN_STACK_RESTORE],
843 tree_cons (NULL_TREE, tmp_var, NULL_TREE));
846 /* Gimplify a BIND_EXPR. Just voidify and recurse. */
848 static enum gimplify_status
849 gimplify_bind_expr (tree *expr_p, tree temp, tree *pre_p)
851 tree bind_expr = *expr_p;
852 bool old_save_stack = gimplify_ctxp->save_stack;
853 tree t;
855 temp = voidify_wrapper_expr (bind_expr, temp);
857 /* Mark variables seen in this bind expr. */
858 for (t = BIND_EXPR_VARS (bind_expr); t ; t = TREE_CHAIN (t))
859 DECL_SEEN_IN_BIND_EXPR_P (t) = 1;
861 gimple_push_bind_expr (bind_expr);
862 gimplify_ctxp->save_stack = false;
864 gimplify_to_stmt_list (&BIND_EXPR_BODY (bind_expr));
866 if (gimplify_ctxp->save_stack)
868 tree stack_save, stack_restore;
870 /* Save stack on entry and restore it on exit. Add a try_finally
871 block to achieve this. Note that mudflap depends on the
872 format of the emitted code: see mx_register_decls(). */
873 build_stack_save_restore (&stack_save, &stack_restore);
875 t = build (TRY_FINALLY_EXPR, void_type_node,
876 BIND_EXPR_BODY (bind_expr), NULL_TREE);
877 append_to_statement_list (stack_restore, &TREE_OPERAND (t, 1));
879 BIND_EXPR_BODY (bind_expr) = NULL_TREE;
880 append_to_statement_list (stack_save, &BIND_EXPR_BODY (bind_expr));
881 append_to_statement_list (t, &BIND_EXPR_BODY (bind_expr));
884 gimplify_ctxp->save_stack = old_save_stack;
885 gimple_pop_bind_expr ();
887 if (temp)
889 *expr_p = temp;
890 append_to_statement_list (bind_expr, pre_p);
891 return GS_OK;
893 else
894 return GS_ALL_DONE;
897 /* Gimplify a RETURN_EXPR. If the expression to be returned is not a
898 GIMPLE value, it is assigned to a new temporary and the statement is
899 re-written to return the temporary.
901 PRE_P points to the list where side effects that must happen before
902 STMT should be stored. */
904 static enum gimplify_status
905 gimplify_return_expr (tree stmt, tree *pre_p)
907 tree ret_expr = TREE_OPERAND (stmt, 0);
908 tree result_decl, result;
910 if (!ret_expr || TREE_CODE (ret_expr) == RESULT_DECL
911 || ret_expr == error_mark_node)
912 return GS_ALL_DONE;
914 if (VOID_TYPE_P (TREE_TYPE (TREE_TYPE (current_function_decl))))
915 result_decl = NULL_TREE;
916 else
918 result_decl = TREE_OPERAND (ret_expr, 0);
919 if (TREE_CODE (result_decl) == INDIRECT_REF)
920 /* See through a return by reference. */
921 result_decl = TREE_OPERAND (result_decl, 0);
923 gcc_assert ((TREE_CODE (ret_expr) == MODIFY_EXPR
924 || TREE_CODE (ret_expr) == INIT_EXPR)
925 && TREE_CODE (result_decl) == RESULT_DECL);
928 /* If aggregate_value_p is true, then we can return the bare RESULT_DECL.
929 Recall that aggregate_value_p is FALSE for any aggregate type that is
930 returned in registers. If we're returning values in registers, then
931 we don't want to extend the lifetime of the RESULT_DECL, particularly
932 across another call. In addition, for those aggregates for which
933 hard_function_value generates a PARALLEL, we'll die during normal
934 expansion of structure assignments; there's special code in expand_return
935 to handle this case that does not exist in expand_expr. */
936 if (!result_decl
937 || aggregate_value_p (result_decl, TREE_TYPE (current_function_decl)))
938 result = result_decl;
939 else if (gimplify_ctxp->return_temp)
940 result = gimplify_ctxp->return_temp;
941 else
943 result = create_tmp_var (TREE_TYPE (result_decl), NULL);
945 /* ??? With complex control flow (usually involving abnormal edges),
946 we can wind up warning about an uninitialized value for this. Due
947 to how this variable is constructed and initialized, this is never
948 true. Give up and never warn. */
949 TREE_NO_WARNING (result) = 1;
951 gimplify_ctxp->return_temp = result;
954 /* Smash the lhs of the MODIFY_EXPR to the temporary we plan to use.
955 Then gimplify the whole thing. */
956 if (result != result_decl)
957 TREE_OPERAND (ret_expr, 0) = result;
959 gimplify_and_add (TREE_OPERAND (stmt, 0), pre_p);
961 /* If we didn't use a temporary, then the result is just the result_decl.
962 Otherwise we need a simple copy. This should already be gimple. */
963 if (result == result_decl)
964 ret_expr = result;
965 else
966 ret_expr = build (MODIFY_EXPR, TREE_TYPE (result), result_decl, result);
967 TREE_OPERAND (stmt, 0) = ret_expr;
969 return GS_ALL_DONE;
972 /* Gimplifies a DECL_EXPR node *STMT_P by making any necessary allocation
973 and initialization explicit. */
975 static enum gimplify_status
976 gimplify_decl_expr (tree *stmt_p)
978 tree stmt = *stmt_p;
979 tree decl = DECL_EXPR_DECL (stmt);
981 *stmt_p = NULL_TREE;
983 if (TREE_TYPE (decl) == error_mark_node)
984 return GS_ERROR;
986 else if (TREE_CODE (decl) == TYPE_DECL)
987 gimplify_type_sizes (TREE_TYPE (decl), stmt_p);
989 else if (TREE_CODE (decl) == VAR_DECL && !DECL_EXTERNAL (decl))
991 tree init = DECL_INITIAL (decl);
993 if (!TREE_CONSTANT (DECL_SIZE (decl)))
995 /* This is a variable-sized decl. Simplify its size and mark it
996 for deferred expansion. Note that mudflap depends on the format
997 of the emitted code: see mx_register_decls(). */
998 tree t, args, addr, ptr_type;
1000 /* ??? We really shouldn't need to gimplify the type of the variable
1001 since it already should have been done. But leave this here
1002 for now to avoid disrupting too many things at once. */
1003 if (!TYPE_SIZES_GIMPLIFIED (TREE_TYPE (decl)))
1004 gimplify_type_sizes (TREE_TYPE (decl), stmt_p);
1006 gimplify_one_sizepos (&DECL_SIZE (decl), stmt_p);
1007 gimplify_one_sizepos (&DECL_SIZE_UNIT (decl), stmt_p);
1009 /* All occurrences of this decl in final gimplified code will be
1010 replaced by indirection. Setting DECL_VALUE_EXPR does two
1011 things: First, it lets the rest of the gimplifier know what
1012 replacement to use. Second, it lets the debug info know
1013 where to find the value. */
1014 ptr_type = build_pointer_type (TREE_TYPE (decl));
1015 addr = create_tmp_var (ptr_type, get_name (decl));
1016 DECL_IGNORED_P (addr) = 0;
1017 t = build_fold_indirect_ref (addr);
1018 DECL_VALUE_EXPR (decl) = t;
1020 args = tree_cons (NULL, DECL_SIZE_UNIT (decl), NULL);
1021 t = built_in_decls[BUILT_IN_ALLOCA];
1022 t = build_function_call_expr (t, args);
1023 t = fold_convert (ptr_type, t);
1024 t = build2 (MODIFY_EXPR, void_type_node, addr, t);
1026 gimplify_and_add (t, stmt_p);
1028 /* Indicate that we need to restore the stack level when the
1029 enclosing BIND_EXPR is exited. */
1030 gimplify_ctxp->save_stack = true;
1033 if (init && init != error_mark_node)
1035 if (!TREE_STATIC (decl))
1037 DECL_INITIAL (decl) = NULL_TREE;
1038 init = build (MODIFY_EXPR, void_type_node, decl, init);
1039 gimplify_and_add (init, stmt_p);
1041 else
1042 /* We must still examine initializers for static variables
1043 as they may contain a label address. */
1044 walk_tree (&init, force_labels_r, NULL, NULL);
1047 /* This decl isn't mentioned in the enclosing block, so add it to the
1048 list of temps. FIXME it seems a bit of a kludge to say that
1049 anonymous artificial vars aren't pushed, but everything else is. */
1050 if (DECL_ARTIFICIAL (decl) && DECL_NAME (decl) == NULL_TREE)
1051 gimple_add_tmp_var (decl);
1054 return GS_ALL_DONE;
1057 /* Gimplify a LOOP_EXPR. Normally this just involves gimplifying the body
1058 and replacing the LOOP_EXPR with goto, but if the loop contains an
1059 EXIT_EXPR, we need to append a label for it to jump to. */
1061 static enum gimplify_status
1062 gimplify_loop_expr (tree *expr_p, tree *pre_p)
1064 tree saved_label = gimplify_ctxp->exit_label;
1065 tree start_label = build1 (LABEL_EXPR, void_type_node, NULL_TREE);
1066 tree jump_stmt = build_and_jump (&LABEL_EXPR_LABEL (start_label));
1068 append_to_statement_list (start_label, pre_p);
1070 gimplify_ctxp->exit_label = NULL_TREE;
1072 gimplify_and_add (LOOP_EXPR_BODY (*expr_p), pre_p);
1074 if (gimplify_ctxp->exit_label)
1076 append_to_statement_list (jump_stmt, pre_p);
1077 *expr_p = build1 (LABEL_EXPR, void_type_node, gimplify_ctxp->exit_label);
1079 else
1080 *expr_p = jump_stmt;
1082 gimplify_ctxp->exit_label = saved_label;
1084 return GS_ALL_DONE;
1087 /* Compare two case labels. Because the front end should already have
1088 made sure that case ranges do not overlap, it is enough to only compare
1089 the CASE_LOW values of each case label. */
1091 static int
1092 compare_case_labels (const void *p1, const void *p2)
1094 tree case1 = *(tree *)p1;
1095 tree case2 = *(tree *)p2;
1097 return tree_int_cst_compare (CASE_LOW (case1), CASE_LOW (case2));
1100 /* Sort the case labels in LABEL_VEC in place in ascending order. */
1102 void
1103 sort_case_labels (tree label_vec)
1105 size_t len = TREE_VEC_LENGTH (label_vec);
1106 tree default_case = TREE_VEC_ELT (label_vec, len - 1);
1108 if (CASE_LOW (default_case))
1110 size_t i;
1112 /* The last label in the vector should be the default case
1113 but it is not. */
1114 for (i = 0; i < len; ++i)
1116 tree t = TREE_VEC_ELT (label_vec, i);
1117 if (!CASE_LOW (t))
1119 default_case = t;
1120 TREE_VEC_ELT (label_vec, i) = TREE_VEC_ELT (label_vec, len - 1);
1121 TREE_VEC_ELT (label_vec, len - 1) = default_case;
1122 break;
1127 qsort (&TREE_VEC_ELT (label_vec, 0), len - 1, sizeof (tree),
1128 compare_case_labels);
1131 /* Gimplify a SWITCH_EXPR, and collect a TREE_VEC of the labels it can
1132 branch to. */
1134 static enum gimplify_status
1135 gimplify_switch_expr (tree *expr_p, tree *pre_p)
1137 tree switch_expr = *expr_p;
1138 enum gimplify_status ret;
1140 ret = gimplify_expr (&SWITCH_COND (switch_expr), pre_p, NULL,
1141 is_gimple_val, fb_rvalue);
1143 if (SWITCH_BODY (switch_expr))
1145 varray_type labels, saved_labels;
1146 tree label_vec, default_case = NULL_TREE;
1147 size_t i, len;
1149 /* If someone can be bothered to fill in the labels, they can
1150 be bothered to null out the body too. */
1151 gcc_assert (!SWITCH_LABELS (switch_expr));
1153 saved_labels = gimplify_ctxp->case_labels;
1154 VARRAY_TREE_INIT (gimplify_ctxp->case_labels, 8, "case_labels");
1156 gimplify_to_stmt_list (&SWITCH_BODY (switch_expr));
1158 labels = gimplify_ctxp->case_labels;
1159 gimplify_ctxp->case_labels = saved_labels;
1161 len = VARRAY_ACTIVE_SIZE (labels);
1163 for (i = 0; i < len; ++i)
1165 tree t = VARRAY_TREE (labels, i);
1166 if (!CASE_LOW (t))
1168 /* The default case must be the last label in the list. */
1169 default_case = t;
1170 VARRAY_TREE (labels, i) = VARRAY_TREE (labels, len - 1);
1171 len--;
1172 break;
1176 label_vec = make_tree_vec (len + 1);
1177 SWITCH_LABELS (*expr_p) = label_vec;
1178 append_to_statement_list (switch_expr, pre_p);
1180 if (! default_case)
1182 /* If the switch has no default label, add one, so that we jump
1183 around the switch body. */
1184 default_case = build (CASE_LABEL_EXPR, void_type_node, NULL_TREE,
1185 NULL_TREE, create_artificial_label ());
1186 append_to_statement_list (SWITCH_BODY (switch_expr), pre_p);
1187 *expr_p = build (LABEL_EXPR, void_type_node,
1188 CASE_LABEL (default_case));
1190 else
1191 *expr_p = SWITCH_BODY (switch_expr);
1193 for (i = 0; i < len; ++i)
1194 TREE_VEC_ELT (label_vec, i) = VARRAY_TREE (labels, i);
1195 TREE_VEC_ELT (label_vec, len) = default_case;
1197 sort_case_labels (label_vec);
1199 SWITCH_BODY (switch_expr) = NULL;
1201 else
1202 gcc_assert (SWITCH_LABELS (switch_expr));
1204 return ret;
1207 static enum gimplify_status
1208 gimplify_case_label_expr (tree *expr_p)
1210 tree expr = *expr_p;
1212 gcc_assert (gimplify_ctxp->case_labels);
1213 VARRAY_PUSH_TREE (gimplify_ctxp->case_labels, expr);
1214 *expr_p = build (LABEL_EXPR, void_type_node, CASE_LABEL (expr));
1215 return GS_ALL_DONE;
1218 /* Build a GOTO to the LABEL_DECL pointed to by LABEL_P, building it first
1219 if necessary. */
1221 tree
1222 build_and_jump (tree *label_p)
1224 if (label_p == NULL)
1225 /* If there's nowhere to jump, just fall through. */
1226 return NULL_TREE;
1228 if (*label_p == NULL_TREE)
1230 tree label = create_artificial_label ();
1231 *label_p = label;
1234 return build1 (GOTO_EXPR, void_type_node, *label_p);
1237 /* Gimplify an EXIT_EXPR by converting to a GOTO_EXPR inside a COND_EXPR.
1238 This also involves building a label to jump to and communicating it to
1239 gimplify_loop_expr through gimplify_ctxp->exit_label. */
1241 static enum gimplify_status
1242 gimplify_exit_expr (tree *expr_p)
1244 tree cond = TREE_OPERAND (*expr_p, 0);
1245 tree expr;
1247 expr = build_and_jump (&gimplify_ctxp->exit_label);
1248 expr = build (COND_EXPR, void_type_node, cond, expr, NULL_TREE);
1249 *expr_p = expr;
1251 return GS_OK;
1254 /* A helper function to be called via walk_tree. Mark all labels under *TP
1255 as being forced. To be called for DECL_INITIAL of static variables. */
1257 tree
1258 force_labels_r (tree *tp, int *walk_subtrees, void *data ATTRIBUTE_UNUSED)
1260 if (TYPE_P (*tp))
1261 *walk_subtrees = 0;
1262 if (TREE_CODE (*tp) == LABEL_DECL)
1263 FORCED_LABEL (*tp) = 1;
1265 return NULL_TREE;
1268 /* *EXPR_P is a COMPONENT_REF being used as an rvalue. If its type is
1269 different from its canonical type, wrap the whole thing inside a
1270 NOP_EXPR and force the type of the COMPONENT_REF to be the canonical
1271 type.
1273 The canonical type of a COMPONENT_REF is the type of the field being
1274 referenced--unless the field is a bit-field which can be read directly
1275 in a smaller mode, in which case the canonical type is the
1276 sign-appropriate type corresponding to that mode. */
1278 static void
1279 canonicalize_component_ref (tree *expr_p)
1281 tree expr = *expr_p;
1282 tree type;
1284 gcc_assert (TREE_CODE (expr) == COMPONENT_REF);
1286 if (INTEGRAL_TYPE_P (TREE_TYPE (expr)))
1287 type = TREE_TYPE (get_unwidened (expr, NULL_TREE));
1288 else
1289 type = TREE_TYPE (TREE_OPERAND (expr, 1));
1291 if (TREE_TYPE (expr) != type)
1293 tree old_type = TREE_TYPE (expr);
1295 /* Set the type of the COMPONENT_REF to the underlying type. */
1296 TREE_TYPE (expr) = type;
1298 /* And wrap the whole thing inside a NOP_EXPR. */
1299 expr = build1 (NOP_EXPR, old_type, expr);
1301 *expr_p = expr;
1305 /* If a NOP conversion is changing a pointer to array of foo to a pointer
1306 to foo, embed that change in the ADDR_EXPR by converting
1307 T array[U];
1308 (T *)&array
1310 &array[L]
1311 where L is the lower bound. For simplicity, only do this for constant
1312 lower bound. */
1314 static void
1315 canonicalize_addr_expr (tree *expr_p)
1317 tree expr = *expr_p;
1318 tree ctype = TREE_TYPE (expr);
1319 tree addr_expr = TREE_OPERAND (expr, 0);
1320 tree atype = TREE_TYPE (addr_expr);
1321 tree dctype, datype, ddatype, otype, obj_expr;
1323 /* Both cast and addr_expr types should be pointers. */
1324 if (!POINTER_TYPE_P (ctype) || !POINTER_TYPE_P (atype))
1325 return;
1327 /* The addr_expr type should be a pointer to an array. */
1328 datype = TREE_TYPE (atype);
1329 if (TREE_CODE (datype) != ARRAY_TYPE)
1330 return;
1332 /* Both cast and addr_expr types should address the same object type. */
1333 dctype = TREE_TYPE (ctype);
1334 ddatype = TREE_TYPE (datype);
1335 if (!lang_hooks.types_compatible_p (ddatype, dctype))
1336 return;
1338 /* The addr_expr and the object type should match. */
1339 obj_expr = TREE_OPERAND (addr_expr, 0);
1340 otype = TREE_TYPE (obj_expr);
1341 if (!lang_hooks.types_compatible_p (otype, datype))
1342 return;
1344 /* The lower bound and element sizes must be constant. */
1345 if (!TYPE_SIZE_UNIT (dctype)
1346 || TREE_CODE (TYPE_SIZE_UNIT (dctype)) != INTEGER_CST
1347 || !TYPE_DOMAIN (datype) || !TYPE_MIN_VALUE (TYPE_DOMAIN (datype))
1348 || TREE_CODE (TYPE_MIN_VALUE (TYPE_DOMAIN (datype))) != INTEGER_CST)
1349 return;
1351 /* All checks succeeded. Build a new node to merge the cast. */
1352 *expr_p = build4 (ARRAY_REF, dctype, obj_expr,
1353 TYPE_MIN_VALUE (TYPE_DOMAIN (datype)),
1354 TYPE_MIN_VALUE (TYPE_DOMAIN (datype)),
1355 size_binop (EXACT_DIV_EXPR, TYPE_SIZE_UNIT (dctype),
1356 size_int (TYPE_ALIGN_UNIT (dctype))));
1357 *expr_p = build1 (ADDR_EXPR, ctype, *expr_p);
1360 /* *EXPR_P is a NOP_EXPR or CONVERT_EXPR. Remove it and/or other conversions
1361 underneath as appropriate. */
1363 static enum gimplify_status
1364 gimplify_conversion (tree *expr_p)
1366 gcc_assert (TREE_CODE (*expr_p) == NOP_EXPR
1367 || TREE_CODE (*expr_p) == CONVERT_EXPR);
1369 /* Then strip away all but the outermost conversion. */
1370 STRIP_SIGN_NOPS (TREE_OPERAND (*expr_p, 0));
1372 /* And remove the outermost conversion if it's useless. */
1373 if (tree_ssa_useless_type_conversion (*expr_p))
1374 *expr_p = TREE_OPERAND (*expr_p, 0);
1376 /* If we still have a conversion at the toplevel,
1377 then canonicalize some constructs. */
1378 if (TREE_CODE (*expr_p) == NOP_EXPR || TREE_CODE (*expr_p) == CONVERT_EXPR)
1380 tree sub = TREE_OPERAND (*expr_p, 0);
1382 /* If a NOP conversion is changing the type of a COMPONENT_REF
1383 expression, then canonicalize its type now in order to expose more
1384 redundant conversions. */
1385 if (TREE_CODE (sub) == COMPONENT_REF)
1386 canonicalize_component_ref (&TREE_OPERAND (*expr_p, 0));
1388 /* If a NOP conversion is changing a pointer to array of foo
1389 to a pointer to foo, embed that change in the ADDR_EXPR. */
1390 else if (TREE_CODE (sub) == ADDR_EXPR)
1391 canonicalize_addr_expr (expr_p);
1394 return GS_OK;
1397 /* Gimplify the COMPONENT_REF, ARRAY_REF, REALPART_EXPR or IMAGPART_EXPR
1398 node pointed by EXPR_P.
1400 compound_lval
1401 : min_lval '[' val ']'
1402 | min_lval '.' ID
1403 | compound_lval '[' val ']'
1404 | compound_lval '.' ID
1406 This is not part of the original SIMPLE definition, which separates
1407 array and member references, but it seems reasonable to handle them
1408 together. Also, this way we don't run into problems with union
1409 aliasing; gcc requires that for accesses through a union to alias, the
1410 union reference must be explicit, which was not always the case when we
1411 were splitting up array and member refs.
1413 PRE_P points to the list where side effects that must happen before
1414 *EXPR_P should be stored.
1416 POST_P points to the list where side effects that must happen after
1417 *EXPR_P should be stored. */
1419 static enum gimplify_status
1420 gimplify_compound_lval (tree *expr_p, tree *pre_p,
1421 tree *post_p, fallback_t fallback)
1423 tree *p;
1424 VEC(tree,heap) *stack;
1425 enum gimplify_status ret = GS_OK, tret;
1426 int i;
1428 /* Create a stack of the subexpressions so later we can walk them in
1429 order from inner to outer. */
1430 stack = VEC_alloc (tree, heap, 10);
1432 /* We can handle anything that get_inner_reference can deal with. */
1433 for (p = expr_p; ; p = &TREE_OPERAND (*p, 0))
1435 /* Fold INDIRECT_REFs now to turn them into ARRAY_REFs. */
1436 if (TREE_CODE (*p) == INDIRECT_REF)
1437 *p = fold_indirect_ref (*p);
1438 if (!handled_component_p (*p))
1439 break;
1440 VEC_safe_push (tree, heap, stack, *p);
1443 gcc_assert (VEC_length (tree, stack));
1445 /* Now STACK is a stack of pointers to all the refs we've walked through
1446 and P points to the innermost expression.
1448 Java requires that we elaborated nodes in source order. That
1449 means we must gimplify the inner expression followed by each of
1450 the indices, in order. But we can't gimplify the inner
1451 expression until we deal with any variable bounds, sizes, or
1452 positions in order to deal with PLACEHOLDER_EXPRs.
1454 So we do this in three steps. First we deal with the annotations
1455 for any variables in the components, then we gimplify the base,
1456 then we gimplify any indices, from left to right. */
1457 for (i = VEC_length (tree, stack) - 1; i >= 0; i--)
1459 tree t = VEC_index (tree, stack, i);
1461 if (TREE_CODE (t) == ARRAY_REF || TREE_CODE (t) == ARRAY_RANGE_REF)
1463 /* Gimplify the low bound and element type size and put them into
1464 the ARRAY_REF. If these values are set, they have already been
1465 gimplified. */
1466 if (!TREE_OPERAND (t, 2))
1468 tree low = unshare_expr (array_ref_low_bound (t));
1469 if (!is_gimple_min_invariant (low))
1471 TREE_OPERAND (t, 2) = low;
1472 tret = gimplify_expr (&TREE_OPERAND (t, 2), pre_p, post_p,
1473 is_gimple_formal_tmp_reg, fb_rvalue);
1474 ret = MIN (ret, tret);
1478 if (!TREE_OPERAND (t, 3))
1480 tree elmt_type = TREE_TYPE (TREE_TYPE (TREE_OPERAND (t, 0)));
1481 tree elmt_size = unshare_expr (array_ref_element_size (t));
1482 tree factor = size_int (TYPE_ALIGN_UNIT (elmt_type));
1484 /* Divide the element size by the alignment of the element
1485 type (above). */
1486 elmt_size = size_binop (EXACT_DIV_EXPR, elmt_size, factor);
1488 if (!is_gimple_min_invariant (elmt_size))
1490 TREE_OPERAND (t, 3) = elmt_size;
1491 tret = gimplify_expr (&TREE_OPERAND (t, 3), pre_p, post_p,
1492 is_gimple_formal_tmp_reg, fb_rvalue);
1493 ret = MIN (ret, tret);
1497 else if (TREE_CODE (t) == COMPONENT_REF)
1499 /* Set the field offset into T and gimplify it. */
1500 if (!TREE_OPERAND (t, 2))
1502 tree offset = unshare_expr (component_ref_field_offset (t));
1503 tree field = TREE_OPERAND (t, 1);
1504 tree factor
1505 = size_int (DECL_OFFSET_ALIGN (field) / BITS_PER_UNIT);
1507 /* Divide the offset by its alignment. */
1508 offset = size_binop (EXACT_DIV_EXPR, offset, factor);
1510 if (!is_gimple_min_invariant (offset))
1512 TREE_OPERAND (t, 2) = offset;
1513 tret = gimplify_expr (&TREE_OPERAND (t, 2), pre_p, post_p,
1514 is_gimple_formal_tmp_reg, fb_rvalue);
1515 ret = MIN (ret, tret);
1521 /* Step 2 is to gimplify the base expression. */
1522 tret = gimplify_expr (p, pre_p, post_p, is_gimple_min_lval, fallback);
1523 ret = MIN (ret, tret);
1525 /* And finally, the indices and operands to BIT_FIELD_REF. During this
1526 loop we also remove any useless conversions. */
1527 for (; VEC_length (tree, stack) > 0; )
1529 tree t = VEC_pop (tree, stack);
1531 if (TREE_CODE (t) == ARRAY_REF || TREE_CODE (t) == ARRAY_RANGE_REF)
1533 /* Gimplify the dimension.
1534 Temporary fix for gcc.c-torture/execute/20040313-1.c.
1535 Gimplify non-constant array indices into a temporary
1536 variable.
1537 FIXME - The real fix is to gimplify post-modify
1538 expressions into a minimal gimple lvalue. However, that
1539 exposes bugs in alias analysis. The alias analyzer does
1540 not handle &PTR->FIELD very well. Will fix after the
1541 branch is merged into mainline (dnovillo 2004-05-03). */
1542 if (!is_gimple_min_invariant (TREE_OPERAND (t, 1)))
1544 tret = gimplify_expr (&TREE_OPERAND (t, 1), pre_p, post_p,
1545 is_gimple_formal_tmp_reg, fb_rvalue);
1546 ret = MIN (ret, tret);
1549 else if (TREE_CODE (t) == BIT_FIELD_REF)
1551 tret = gimplify_expr (&TREE_OPERAND (t, 1), pre_p, post_p,
1552 is_gimple_val, fb_rvalue);
1553 ret = MIN (ret, tret);
1554 tret = gimplify_expr (&TREE_OPERAND (t, 2), pre_p, post_p,
1555 is_gimple_val, fb_rvalue);
1556 ret = MIN (ret, tret);
1559 STRIP_USELESS_TYPE_CONVERSION (TREE_OPERAND (t, 0));
1561 /* The innermost expression P may have originally had TREE_SIDE_EFFECTS
1562 set which would have caused all the outer expressions in EXPR_P
1563 leading to P to also have had TREE_SIDE_EFFECTS set. */
1564 recalculate_side_effects (t);
1567 tret = gimplify_expr (p, pre_p, post_p, is_gimple_min_lval, fallback);
1568 ret = MIN (ret, tret);
1570 /* If the outermost expression is a COMPONENT_REF, canonicalize its type. */
1571 if ((fallback & fb_rvalue) && TREE_CODE (*expr_p) == COMPONENT_REF)
1573 canonicalize_component_ref (expr_p);
1574 ret = MIN (ret, GS_OK);
1577 VEC_free (tree, heap, stack);
1579 return ret;
1582 /* Gimplify the self modifying expression pointed by EXPR_P (++, --, +=, -=).
1584 PRE_P points to the list where side effects that must happen before
1585 *EXPR_P should be stored.
1587 POST_P points to the list where side effects that must happen after
1588 *EXPR_P should be stored.
1590 WANT_VALUE is nonzero iff we want to use the value of this expression
1591 in another expression. */
1593 static enum gimplify_status
1594 gimplify_self_mod_expr (tree *expr_p, tree *pre_p, tree *post_p,
1595 bool want_value)
1597 enum tree_code code;
1598 tree lhs, lvalue, rhs, t1;
1599 bool postfix;
1600 enum tree_code arith_code;
1601 enum gimplify_status ret;
1603 code = TREE_CODE (*expr_p);
1605 gcc_assert (code == POSTINCREMENT_EXPR || code == POSTDECREMENT_EXPR
1606 || code == PREINCREMENT_EXPR || code == PREDECREMENT_EXPR);
1608 /* Prefix or postfix? */
1609 if (code == POSTINCREMENT_EXPR || code == POSTDECREMENT_EXPR)
1610 /* Faster to treat as prefix if result is not used. */
1611 postfix = want_value;
1612 else
1613 postfix = false;
1615 /* Add or subtract? */
1616 if (code == PREINCREMENT_EXPR || code == POSTINCREMENT_EXPR)
1617 arith_code = PLUS_EXPR;
1618 else
1619 arith_code = MINUS_EXPR;
1621 /* Gimplify the LHS into a GIMPLE lvalue. */
1622 lvalue = TREE_OPERAND (*expr_p, 0);
1623 ret = gimplify_expr (&lvalue, pre_p, post_p, is_gimple_lvalue, fb_lvalue);
1624 if (ret == GS_ERROR)
1625 return ret;
1627 /* Extract the operands to the arithmetic operation. */
1628 lhs = lvalue;
1629 rhs = TREE_OPERAND (*expr_p, 1);
1631 /* For postfix operator, we evaluate the LHS to an rvalue and then use
1632 that as the result value and in the postqueue operation. */
1633 if (postfix)
1635 ret = gimplify_expr (&lhs, pre_p, post_p, is_gimple_val, fb_rvalue);
1636 if (ret == GS_ERROR)
1637 return ret;
1640 t1 = build (arith_code, TREE_TYPE (*expr_p), lhs, rhs);
1641 t1 = build (MODIFY_EXPR, TREE_TYPE (lvalue), lvalue, t1);
1643 if (postfix)
1645 gimplify_and_add (t1, post_p);
1646 *expr_p = lhs;
1647 return GS_ALL_DONE;
1649 else
1651 *expr_p = t1;
1652 return GS_OK;
1656 /* If *EXPR_P has a variable sized type, wrap it in a WITH_SIZE_EXPR. */
1658 static void
1659 maybe_with_size_expr (tree *expr_p)
1661 tree expr = *expr_p;
1662 tree type = TREE_TYPE (expr);
1663 tree size;
1665 /* If we've already wrapped this or the type is error_mark_node, we can't do
1666 anything. */
1667 if (TREE_CODE (expr) == WITH_SIZE_EXPR
1668 || type == error_mark_node)
1669 return;
1671 /* If the size isn't known or is a constant, we have nothing to do. */
1672 size = TYPE_SIZE_UNIT (type);
1673 if (!size || TREE_CODE (size) == INTEGER_CST)
1674 return;
1676 /* Otherwise, make a WITH_SIZE_EXPR. */
1677 size = unshare_expr (size);
1678 size = SUBSTITUTE_PLACEHOLDER_IN_EXPR (size, expr);
1679 *expr_p = build2 (WITH_SIZE_EXPR, type, expr, size);
1682 /* Subroutine of gimplify_call_expr: Gimplify a single argument. */
1684 static enum gimplify_status
1685 gimplify_arg (tree *expr_p, tree *pre_p)
1687 bool (*test) (tree);
1688 fallback_t fb;
1690 /* In general, we allow lvalues for function arguments to avoid
1691 extra overhead of copying large aggregates out of even larger
1692 aggregates into temporaries only to copy the temporaries to
1693 the argument list. Make optimizers happy by pulling out to
1694 temporaries those types that fit in registers. */
1695 if (is_gimple_reg_type (TREE_TYPE (*expr_p)))
1696 test = is_gimple_val, fb = fb_rvalue;
1697 else
1698 test = is_gimple_lvalue, fb = fb_either;
1700 /* If this is a variable sized type, we must remember the size. */
1701 maybe_with_size_expr (expr_p);
1703 /* There is a sequence point before a function call. Side effects in
1704 the argument list must occur before the actual call. So, when
1705 gimplifying arguments, force gimplify_expr to use an internal
1706 post queue which is then appended to the end of PRE_P. */
1707 return gimplify_expr (expr_p, pre_p, NULL, test, fb);
1710 /* Gimplify the CALL_EXPR node pointed by EXPR_P. PRE_P points to the
1711 list where side effects that must happen before *EXPR_P should be stored.
1712 WANT_VALUE is true if the result of the call is desired. */
1714 static enum gimplify_status
1715 gimplify_call_expr (tree *expr_p, tree *pre_p, bool want_value)
1717 tree decl;
1718 tree arglist;
1719 enum gimplify_status ret;
1721 gcc_assert (TREE_CODE (*expr_p) == CALL_EXPR);
1723 /* For reliable diagnostics during inlining, it is necessary that
1724 every call_expr be annotated with file and line. */
1725 if (! EXPR_HAS_LOCATION (*expr_p))
1726 SET_EXPR_LOCATION (*expr_p, input_location);
1728 /* This may be a call to a builtin function.
1730 Builtin function calls may be transformed into different
1731 (and more efficient) builtin function calls under certain
1732 circumstances. Unfortunately, gimplification can muck things
1733 up enough that the builtin expanders are not aware that certain
1734 transformations are still valid.
1736 So we attempt transformation/gimplification of the call before
1737 we gimplify the CALL_EXPR. At this time we do not manage to
1738 transform all calls in the same manner as the expanders do, but
1739 we do transform most of them. */
1740 decl = get_callee_fndecl (*expr_p);
1741 if (decl && DECL_BUILT_IN (decl))
1743 tree fndecl = get_callee_fndecl (*expr_p);
1744 tree arglist = TREE_OPERAND (*expr_p, 1);
1745 tree new = fold_builtin (fndecl, arglist, !want_value);
1747 if (new && new != *expr_p)
1749 /* There was a transformation of this call which computes the
1750 same value, but in a more efficient way. Return and try
1751 again. */
1752 *expr_p = new;
1753 return GS_OK;
1756 if (DECL_BUILT_IN_CLASS (decl) == BUILT_IN_NORMAL
1757 && DECL_FUNCTION_CODE (decl) == BUILT_IN_VA_START)
1759 if (!arglist || !TREE_CHAIN (arglist))
1761 error ("too few arguments to function %<va_start%>");
1762 *expr_p = build_empty_stmt ();
1763 return GS_OK;
1766 if (fold_builtin_next_arg (TREE_CHAIN (arglist)))
1768 *expr_p = build_empty_stmt ();
1769 return GS_OK;
1771 /* Avoid gimplifying the second argument to va_start, which needs
1772 to be the plain PARM_DECL. */
1773 return gimplify_arg (&TREE_VALUE (TREE_OPERAND (*expr_p, 1)), pre_p);
1777 /* There is a sequence point before the call, so any side effects in
1778 the calling expression must occur before the actual call. Force
1779 gimplify_expr to use an internal post queue. */
1780 ret = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p, NULL,
1781 is_gimple_call_addr, fb_rvalue);
1783 if (PUSH_ARGS_REVERSED)
1784 TREE_OPERAND (*expr_p, 1) = nreverse (TREE_OPERAND (*expr_p, 1));
1785 for (arglist = TREE_OPERAND (*expr_p, 1); arglist;
1786 arglist = TREE_CHAIN (arglist))
1788 enum gimplify_status t;
1790 t = gimplify_arg (&TREE_VALUE (arglist), pre_p);
1792 if (t == GS_ERROR)
1793 ret = GS_ERROR;
1795 if (PUSH_ARGS_REVERSED)
1796 TREE_OPERAND (*expr_p, 1) = nreverse (TREE_OPERAND (*expr_p, 1));
1798 /* Try this again in case gimplification exposed something. */
1799 if (ret != GS_ERROR && decl && DECL_BUILT_IN (decl))
1801 tree fndecl = get_callee_fndecl (*expr_p);
1802 tree arglist = TREE_OPERAND (*expr_p, 1);
1803 tree new = fold_builtin (fndecl, arglist, !want_value);
1805 if (new && new != *expr_p)
1807 /* There was a transformation of this call which computes the
1808 same value, but in a more efficient way. Return and try
1809 again. */
1810 *expr_p = new;
1811 return GS_OK;
1815 /* If the function is "const" or "pure", then clear TREE_SIDE_EFFECTS on its
1816 decl. This allows us to eliminate redundant or useless
1817 calls to "const" functions. */
1818 if (TREE_CODE (*expr_p) == CALL_EXPR
1819 && (call_expr_flags (*expr_p) & (ECF_CONST | ECF_PURE)))
1820 TREE_SIDE_EFFECTS (*expr_p) = 0;
1822 return ret;
1825 /* Handle shortcut semantics in the predicate operand of a COND_EXPR by
1826 rewriting it into multiple COND_EXPRs, and possibly GOTO_EXPRs.
1828 TRUE_LABEL_P and FALSE_LABEL_P point to the labels to jump to if the
1829 condition is true or false, respectively. If null, we should generate
1830 our own to skip over the evaluation of this specific expression.
1832 This function is the tree equivalent of do_jump.
1834 shortcut_cond_r should only be called by shortcut_cond_expr. */
1836 static tree
1837 shortcut_cond_r (tree pred, tree *true_label_p, tree *false_label_p)
1839 tree local_label = NULL_TREE;
1840 tree t, expr = NULL;
1842 /* OK, it's not a simple case; we need to pull apart the COND_EXPR to
1843 retain the shortcut semantics. Just insert the gotos here;
1844 shortcut_cond_expr will append the real blocks later. */
1845 if (TREE_CODE (pred) == TRUTH_ANDIF_EXPR)
1847 /* Turn if (a && b) into
1849 if (a); else goto no;
1850 if (b) goto yes; else goto no;
1851 (no:) */
1853 if (false_label_p == NULL)
1854 false_label_p = &local_label;
1856 t = shortcut_cond_r (TREE_OPERAND (pred, 0), NULL, false_label_p);
1857 append_to_statement_list (t, &expr);
1859 t = shortcut_cond_r (TREE_OPERAND (pred, 1), true_label_p,
1860 false_label_p);
1861 append_to_statement_list (t, &expr);
1863 else if (TREE_CODE (pred) == TRUTH_ORIF_EXPR)
1865 /* Turn if (a || b) into
1867 if (a) goto yes;
1868 if (b) goto yes; else goto no;
1869 (yes:) */
1871 if (true_label_p == NULL)
1872 true_label_p = &local_label;
1874 t = shortcut_cond_r (TREE_OPERAND (pred, 0), true_label_p, NULL);
1875 append_to_statement_list (t, &expr);
1877 t = shortcut_cond_r (TREE_OPERAND (pred, 1), true_label_p,
1878 false_label_p);
1879 append_to_statement_list (t, &expr);
1881 else if (TREE_CODE (pred) == COND_EXPR)
1883 /* As long as we're messing with gotos, turn if (a ? b : c) into
1884 if (a)
1885 if (b) goto yes; else goto no;
1886 else
1887 if (c) goto yes; else goto no; */
1888 expr = build (COND_EXPR, void_type_node, TREE_OPERAND (pred, 0),
1889 shortcut_cond_r (TREE_OPERAND (pred, 1), true_label_p,
1890 false_label_p),
1891 shortcut_cond_r (TREE_OPERAND (pred, 2), true_label_p,
1892 false_label_p));
1894 else
1896 expr = build (COND_EXPR, void_type_node, pred,
1897 build_and_jump (true_label_p),
1898 build_and_jump (false_label_p));
1901 if (local_label)
1903 t = build1 (LABEL_EXPR, void_type_node, local_label);
1904 append_to_statement_list (t, &expr);
1907 return expr;
1910 static tree
1911 shortcut_cond_expr (tree expr)
1913 tree pred = TREE_OPERAND (expr, 0);
1914 tree then_ = TREE_OPERAND (expr, 1);
1915 tree else_ = TREE_OPERAND (expr, 2);
1916 tree true_label, false_label, end_label, t;
1917 tree *true_label_p;
1918 tree *false_label_p;
1919 bool emit_end, emit_false, jump_over_else;
1920 bool then_se = then_ && TREE_SIDE_EFFECTS (then_);
1921 bool else_se = else_ && TREE_SIDE_EFFECTS (else_);
1923 /* First do simple transformations. */
1924 if (!else_se)
1926 /* If there is no 'else', turn (a && b) into if (a) if (b). */
1927 while (TREE_CODE (pred) == TRUTH_ANDIF_EXPR)
1929 TREE_OPERAND (expr, 0) = TREE_OPERAND (pred, 1);
1930 then_ = shortcut_cond_expr (expr);
1931 then_se = then_ && TREE_SIDE_EFFECTS (then_);
1932 pred = TREE_OPERAND (pred, 0);
1933 expr = build (COND_EXPR, void_type_node, pred, then_, NULL_TREE);
1936 if (!then_se)
1938 /* If there is no 'then', turn
1939 if (a || b); else d
1940 into
1941 if (a); else if (b); else d. */
1942 while (TREE_CODE (pred) == TRUTH_ORIF_EXPR)
1944 TREE_OPERAND (expr, 0) = TREE_OPERAND (pred, 1);
1945 else_ = shortcut_cond_expr (expr);
1946 else_se = else_ && TREE_SIDE_EFFECTS (else_);
1947 pred = TREE_OPERAND (pred, 0);
1948 expr = build (COND_EXPR, void_type_node, pred, NULL_TREE, else_);
1952 /* If we're done, great. */
1953 if (TREE_CODE (pred) != TRUTH_ANDIF_EXPR
1954 && TREE_CODE (pred) != TRUTH_ORIF_EXPR)
1955 return expr;
1957 /* Otherwise we need to mess with gotos. Change
1958 if (a) c; else d;
1960 if (a); else goto no;
1961 c; goto end;
1962 no: d; end:
1963 and recursively gimplify the condition. */
1965 true_label = false_label = end_label = NULL_TREE;
1967 /* If our arms just jump somewhere, hijack those labels so we don't
1968 generate jumps to jumps. */
1970 if (then_
1971 && TREE_CODE (then_) == GOTO_EXPR
1972 && TREE_CODE (GOTO_DESTINATION (then_)) == LABEL_DECL)
1974 true_label = GOTO_DESTINATION (then_);
1975 then_ = NULL;
1976 then_se = false;
1979 if (else_
1980 && TREE_CODE (else_) == GOTO_EXPR
1981 && TREE_CODE (GOTO_DESTINATION (else_)) == LABEL_DECL)
1983 false_label = GOTO_DESTINATION (else_);
1984 else_ = NULL;
1985 else_se = false;
1988 /* If we aren't hijacking a label for the 'then' branch, it falls through. */
1989 if (true_label)
1990 true_label_p = &true_label;
1991 else
1992 true_label_p = NULL;
1994 /* The 'else' branch also needs a label if it contains interesting code. */
1995 if (false_label || else_se)
1996 false_label_p = &false_label;
1997 else
1998 false_label_p = NULL;
2000 /* If there was nothing else in our arms, just forward the label(s). */
2001 if (!then_se && !else_se)
2002 return shortcut_cond_r (pred, true_label_p, false_label_p);
2004 /* If our last subexpression already has a terminal label, reuse it. */
2005 if (else_se)
2006 expr = expr_last (else_);
2007 else if (then_se)
2008 expr = expr_last (then_);
2009 else
2010 expr = NULL;
2011 if (expr && TREE_CODE (expr) == LABEL_EXPR)
2012 end_label = LABEL_EXPR_LABEL (expr);
2014 /* If we don't care about jumping to the 'else' branch, jump to the end
2015 if the condition is false. */
2016 if (!false_label_p)
2017 false_label_p = &end_label;
2019 /* We only want to emit these labels if we aren't hijacking them. */
2020 emit_end = (end_label == NULL_TREE);
2021 emit_false = (false_label == NULL_TREE);
2023 /* We only emit the jump over the else clause if we have to--if the
2024 then clause may fall through. Otherwise we can wind up with a
2025 useless jump and a useless label at the end of gimplified code,
2026 which will cause us to think that this conditional as a whole
2027 falls through even if it doesn't. If we then inline a function
2028 which ends with such a condition, that can cause us to issue an
2029 inappropriate warning about control reaching the end of a
2030 non-void function. */
2031 jump_over_else = block_may_fallthru (then_);
2033 pred = shortcut_cond_r (pred, true_label_p, false_label_p);
2035 expr = NULL;
2036 append_to_statement_list (pred, &expr);
2038 append_to_statement_list (then_, &expr);
2039 if (else_se)
2041 if (jump_over_else)
2043 t = build_and_jump (&end_label);
2044 append_to_statement_list (t, &expr);
2046 if (emit_false)
2048 t = build1 (LABEL_EXPR, void_type_node, false_label);
2049 append_to_statement_list (t, &expr);
2051 append_to_statement_list (else_, &expr);
2053 if (emit_end && end_label)
2055 t = build1 (LABEL_EXPR, void_type_node, end_label);
2056 append_to_statement_list (t, &expr);
2059 return expr;
2062 /* EXPR is used in a boolean context; make sure it has BOOLEAN_TYPE. */
2064 static tree
2065 gimple_boolify (tree expr)
2067 tree type = TREE_TYPE (expr);
2069 if (TREE_CODE (type) == BOOLEAN_TYPE)
2070 return expr;
2072 switch (TREE_CODE (expr))
2074 case TRUTH_AND_EXPR:
2075 case TRUTH_OR_EXPR:
2076 case TRUTH_XOR_EXPR:
2077 case TRUTH_ANDIF_EXPR:
2078 case TRUTH_ORIF_EXPR:
2079 /* Also boolify the arguments of truth exprs. */
2080 TREE_OPERAND (expr, 1) = gimple_boolify (TREE_OPERAND (expr, 1));
2081 /* FALLTHRU */
2083 case TRUTH_NOT_EXPR:
2084 TREE_OPERAND (expr, 0) = gimple_boolify (TREE_OPERAND (expr, 0));
2085 /* FALLTHRU */
2087 case EQ_EXPR: case NE_EXPR:
2088 case LE_EXPR: case GE_EXPR: case LT_EXPR: case GT_EXPR:
2089 /* These expressions always produce boolean results. */
2090 TREE_TYPE (expr) = boolean_type_node;
2091 return expr;
2093 default:
2094 /* Other expressions that get here must have boolean values, but
2095 might need to be converted to the appropriate mode. */
2096 return convert (boolean_type_node, expr);
2100 /* Convert the conditional expression pointed by EXPR_P '(p) ? a : b;'
2101 into
2103 if (p) if (p)
2104 t1 = a; a;
2105 else or else
2106 t1 = b; b;
2109 The second form is used when *EXPR_P is of type void.
2111 TARGET is the tree for T1 above.
2113 PRE_P points to the list where side effects that must happen before
2114 *EXPR_P should be stored.
2116 POST_P points to the list where side effects that must happen after
2117 *EXPR_P should be stored. */
2119 static enum gimplify_status
2120 gimplify_cond_expr (tree *expr_p, tree *pre_p, tree *post_p, tree target,
2121 fallback_t fallback)
2123 tree expr = *expr_p;
2124 tree tmp, tmp2, type;
2125 enum gimplify_status ret;
2127 type = TREE_TYPE (expr);
2128 if (!type)
2129 TREE_TYPE (expr) = void_type_node;
2131 /* If this COND_EXPR has a value, copy the values into a temporary within
2132 the arms. */
2133 else if (! VOID_TYPE_P (type))
2135 tree result;
2137 if (target)
2139 ret = gimplify_expr (&target, pre_p, post_p,
2140 is_gimple_min_lval, fb_lvalue);
2141 if (ret != GS_ERROR)
2142 ret = GS_OK;
2143 result = tmp = target;
2144 tmp2 = unshare_expr (target);
2146 else if ((fallback & fb_lvalue) == 0)
2148 result = tmp2 = tmp = create_tmp_var (TREE_TYPE (expr), "iftmp");
2149 ret = GS_ALL_DONE;
2151 else
2153 tree type = build_pointer_type (TREE_TYPE (expr));
2155 if (TREE_TYPE (TREE_OPERAND (expr, 1)) != void_type_node)
2156 TREE_OPERAND (expr, 1) =
2157 build_fold_addr_expr (TREE_OPERAND (expr, 1));
2159 if (TREE_TYPE (TREE_OPERAND (expr, 2)) != void_type_node)
2160 TREE_OPERAND (expr, 2) =
2161 build_fold_addr_expr (TREE_OPERAND (expr, 2));
2163 tmp2 = tmp = create_tmp_var (type, "iftmp");
2165 expr = build (COND_EXPR, void_type_node, TREE_OPERAND (expr, 0),
2166 TREE_OPERAND (expr, 1), TREE_OPERAND (expr, 2));
2168 result = build_fold_indirect_ref (tmp);
2169 ret = GS_ALL_DONE;
2172 /* Build the then clause, 't1 = a;'. But don't build an assignment
2173 if this branch is void; in C++ it can be, if it's a throw. */
2174 if (TREE_TYPE (TREE_OPERAND (expr, 1)) != void_type_node)
2175 TREE_OPERAND (expr, 1)
2176 = build (MODIFY_EXPR, void_type_node, tmp, TREE_OPERAND (expr, 1));
2178 /* Build the else clause, 't1 = b;'. */
2179 if (TREE_TYPE (TREE_OPERAND (expr, 2)) != void_type_node)
2180 TREE_OPERAND (expr, 2)
2181 = build (MODIFY_EXPR, void_type_node, tmp2, TREE_OPERAND (expr, 2));
2183 TREE_TYPE (expr) = void_type_node;
2184 recalculate_side_effects (expr);
2186 /* Move the COND_EXPR to the prequeue. */
2187 gimplify_and_add (expr, pre_p);
2189 *expr_p = result;
2190 return ret;
2193 /* Make sure the condition has BOOLEAN_TYPE. */
2194 TREE_OPERAND (expr, 0) = gimple_boolify (TREE_OPERAND (expr, 0));
2196 /* Break apart && and || conditions. */
2197 if (TREE_CODE (TREE_OPERAND (expr, 0)) == TRUTH_ANDIF_EXPR
2198 || TREE_CODE (TREE_OPERAND (expr, 0)) == TRUTH_ORIF_EXPR)
2200 expr = shortcut_cond_expr (expr);
2202 if (expr != *expr_p)
2204 *expr_p = expr;
2206 /* We can't rely on gimplify_expr to re-gimplify the expanded
2207 form properly, as cleanups might cause the target labels to be
2208 wrapped in a TRY_FINALLY_EXPR. To prevent that, we need to
2209 set up a conditional context. */
2210 gimple_push_condition ();
2211 gimplify_stmt (expr_p);
2212 gimple_pop_condition (pre_p);
2214 return GS_ALL_DONE;
2218 /* Now do the normal gimplification. */
2219 ret = gimplify_expr (&TREE_OPERAND (expr, 0), pre_p, NULL,
2220 is_gimple_condexpr, fb_rvalue);
2222 gimple_push_condition ();
2224 gimplify_to_stmt_list (&TREE_OPERAND (expr, 1));
2225 gimplify_to_stmt_list (&TREE_OPERAND (expr, 2));
2226 recalculate_side_effects (expr);
2228 gimple_pop_condition (pre_p);
2230 if (ret == GS_ERROR)
2232 else if (TREE_SIDE_EFFECTS (TREE_OPERAND (expr, 1)))
2233 ret = GS_ALL_DONE;
2234 else if (TREE_SIDE_EFFECTS (TREE_OPERAND (expr, 2)))
2235 /* Rewrite "if (a); else b" to "if (!a) b" */
2237 TREE_OPERAND (expr, 0) = invert_truthvalue (TREE_OPERAND (expr, 0));
2238 ret = gimplify_expr (&TREE_OPERAND (expr, 0), pre_p, NULL,
2239 is_gimple_condexpr, fb_rvalue);
2241 tmp = TREE_OPERAND (expr, 1);
2242 TREE_OPERAND (expr, 1) = TREE_OPERAND (expr, 2);
2243 TREE_OPERAND (expr, 2) = tmp;
2245 else
2246 /* Both arms are empty; replace the COND_EXPR with its predicate. */
2247 expr = TREE_OPERAND (expr, 0);
2249 *expr_p = expr;
2250 return ret;
2253 /* A subroutine of gimplify_modify_expr. Replace a MODIFY_EXPR with
2254 a call to __builtin_memcpy. */
2256 static enum gimplify_status
2257 gimplify_modify_expr_to_memcpy (tree *expr_p, tree size, bool want_value)
2259 tree args, t, to, to_ptr, from;
2261 to = TREE_OPERAND (*expr_p, 0);
2262 from = TREE_OPERAND (*expr_p, 1);
2264 args = tree_cons (NULL, size, NULL);
2266 t = build_fold_addr_expr (from);
2267 args = tree_cons (NULL, t, args);
2269 to_ptr = build_fold_addr_expr (to);
2270 args = tree_cons (NULL, to_ptr, args);
2271 t = implicit_built_in_decls[BUILT_IN_MEMCPY];
2272 t = build_function_call_expr (t, args);
2274 if (want_value)
2276 t = build1 (NOP_EXPR, TREE_TYPE (to_ptr), t);
2277 t = build1 (INDIRECT_REF, TREE_TYPE (to), t);
2280 *expr_p = t;
2281 return GS_OK;
2284 /* A subroutine of gimplify_modify_expr. Replace a MODIFY_EXPR with
2285 a call to __builtin_memset. In this case we know that the RHS is
2286 a CONSTRUCTOR with an empty element list. */
2288 static enum gimplify_status
2289 gimplify_modify_expr_to_memset (tree *expr_p, tree size, bool want_value)
2291 tree args, t, to, to_ptr;
2293 to = TREE_OPERAND (*expr_p, 0);
2295 args = tree_cons (NULL, size, NULL);
2297 args = tree_cons (NULL, integer_zero_node, args);
2299 to_ptr = build_fold_addr_expr (to);
2300 args = tree_cons (NULL, to_ptr, args);
2301 t = implicit_built_in_decls[BUILT_IN_MEMSET];
2302 t = build_function_call_expr (t, args);
2304 if (want_value)
2306 t = build1 (NOP_EXPR, TREE_TYPE (to_ptr), t);
2307 t = build1 (INDIRECT_REF, TREE_TYPE (to), t);
2310 *expr_p = t;
2311 return GS_OK;
2314 /* A subroutine of gimplify_init_ctor_preeval. Called via walk_tree,
2315 determine, cautiously, if a CONSTRUCTOR overlaps the lhs of an
2316 assignment. Returns non-null if we detect a potential overlap. */
2318 struct gimplify_init_ctor_preeval_data
2320 /* The base decl of the lhs object. May be NULL, in which case we
2321 have to assume the lhs is indirect. */
2322 tree lhs_base_decl;
2324 /* The alias set of the lhs object. */
2325 int lhs_alias_set;
2328 static tree
2329 gimplify_init_ctor_preeval_1 (tree *tp, int *walk_subtrees, void *xdata)
2331 struct gimplify_init_ctor_preeval_data *data
2332 = (struct gimplify_init_ctor_preeval_data *) xdata;
2333 tree t = *tp;
2335 /* If we find the base object, obviously we have overlap. */
2336 if (data->lhs_base_decl == t)
2337 return t;
2339 /* If the constructor component is indirect, determine if we have a
2340 potential overlap with the lhs. The only bits of information we
2341 have to go on at this point are addressability and alias sets. */
2342 if (TREE_CODE (t) == INDIRECT_REF
2343 && (!data->lhs_base_decl || TREE_ADDRESSABLE (data->lhs_base_decl))
2344 && alias_sets_conflict_p (data->lhs_alias_set, get_alias_set (t)))
2345 return t;
2347 if (IS_TYPE_OR_DECL_P (t))
2348 *walk_subtrees = 0;
2349 return NULL;
2352 /* A subroutine of gimplify_init_constructor. Pre-evaluate *EXPR_P,
2353 force values that overlap with the lhs (as described by *DATA)
2354 into temporaries. */
2356 static void
2357 gimplify_init_ctor_preeval (tree *expr_p, tree *pre_p, tree *post_p,
2358 struct gimplify_init_ctor_preeval_data *data)
2360 enum gimplify_status one;
2362 /* If the value is invariant, then there's nothing to pre-evaluate.
2363 But ensure it doesn't have any side-effects since a SAVE_EXPR is
2364 invariant but has side effects and might contain a reference to
2365 the object we're initializing. */
2366 if (TREE_INVARIANT (*expr_p) && !TREE_SIDE_EFFECTS (*expr_p))
2367 return;
2369 /* If the type has non-trivial constructors, we can't pre-evaluate. */
2370 if (TREE_ADDRESSABLE (TREE_TYPE (*expr_p)))
2371 return;
2373 /* Recurse for nested constructors. */
2374 if (TREE_CODE (*expr_p) == CONSTRUCTOR)
2376 tree list;
2377 for (list = CONSTRUCTOR_ELTS (*expr_p); list ; list = TREE_CHAIN (list))
2378 gimplify_init_ctor_preeval (&TREE_VALUE (list), pre_p, post_p, data);
2379 return;
2382 /* We can't preevaluate if the type contains a placeholder. */
2383 if (type_contains_placeholder_p (TREE_TYPE (*expr_p)))
2384 return;
2386 /* Gimplify the constructor element to something appropriate for the rhs
2387 of a MODIFY_EXPR. Given that we know the lhs is an aggregate, we know
2388 the gimplifier will consider this a store to memory. Doing this
2389 gimplification now means that we won't have to deal with complicated
2390 language-specific trees, nor trees like SAVE_EXPR that can induce
2391 exponential search behavior. */
2392 one = gimplify_expr (expr_p, pre_p, post_p, is_gimple_mem_rhs, fb_rvalue);
2393 if (one == GS_ERROR)
2395 *expr_p = NULL;
2396 return;
2399 /* If we gimplified to a bare decl, we can be sure that it doesn't overlap
2400 with the lhs, since "a = { .x=a }" doesn't make sense. This will
2401 always be true for all scalars, since is_gimple_mem_rhs insists on a
2402 temporary variable for them. */
2403 if (DECL_P (*expr_p))
2404 return;
2406 /* If this is of variable size, we have no choice but to assume it doesn't
2407 overlap since we can't make a temporary for it. */
2408 if (!TREE_CONSTANT (TYPE_SIZE (TREE_TYPE (*expr_p))))
2409 return;
2411 /* Otherwise, we must search for overlap ... */
2412 if (!walk_tree (expr_p, gimplify_init_ctor_preeval_1, data, NULL))
2413 return;
2415 /* ... and if found, force the value into a temporary. */
2416 *expr_p = get_formal_tmp_var (*expr_p, pre_p);
2419 /* A subroutine of gimplify_init_ctor_eval. Create a loop for
2420 a RANGE_EXPR in a CONSTRUCTOR for an array.
2422 var = lower;
2423 loop_entry:
2424 object[var] = value;
2425 if (var == upper)
2426 goto loop_exit;
2427 var = var + 1;
2428 goto loop_entry;
2429 loop_exit:
2431 We increment var _after_ the loop exit check because we might otherwise
2432 fail if upper == TYPE_MAX_VALUE (type for upper).
2434 Note that we never have to deal with SAVE_EXPRs here, because this has
2435 already been taken care of for us, in gimplify_init_ctor_preeval(). */
2437 static void gimplify_init_ctor_eval (tree, tree, tree *, bool);
2439 static void
2440 gimplify_init_ctor_eval_range (tree object, tree lower, tree upper,
2441 tree value, tree array_elt_type,
2442 tree *pre_p, bool cleared)
2444 tree loop_entry_label, loop_exit_label;
2445 tree var, var_type, cref;
2447 loop_entry_label = create_artificial_label ();
2448 loop_exit_label = create_artificial_label ();
2450 /* Create and initialize the index variable. */
2451 var_type = TREE_TYPE (upper);
2452 var = create_tmp_var (var_type, NULL);
2453 append_to_statement_list (build2 (MODIFY_EXPR, var_type, var, lower), pre_p);
2455 /* Add the loop entry label. */
2456 append_to_statement_list (build1 (LABEL_EXPR,
2457 void_type_node,
2458 loop_entry_label),
2459 pre_p);
2461 /* Build the reference. */
2462 cref = build4 (ARRAY_REF, array_elt_type, unshare_expr (object),
2463 var, NULL_TREE, NULL_TREE);
2465 /* If we are a constructor, just call gimplify_init_ctor_eval to do
2466 the store. Otherwise just assign value to the reference. */
2468 if (TREE_CODE (value) == CONSTRUCTOR)
2469 /* NB we might have to call ourself recursively through
2470 gimplify_init_ctor_eval if the value is a constructor. */
2471 gimplify_init_ctor_eval (cref, CONSTRUCTOR_ELTS (value),
2472 pre_p, cleared);
2473 else
2474 append_to_statement_list (build2 (MODIFY_EXPR, TREE_TYPE (cref),
2475 cref, value),
2476 pre_p);
2478 /* We exit the loop when the index var is equal to the upper bound. */
2479 gimplify_and_add (build3 (COND_EXPR, void_type_node,
2480 build2 (EQ_EXPR, boolean_type_node,
2481 var, upper),
2482 build1 (GOTO_EXPR,
2483 void_type_node,
2484 loop_exit_label),
2485 NULL_TREE),
2486 pre_p);
2488 /* Otherwise, increment the index var... */
2489 append_to_statement_list (build2 (MODIFY_EXPR, var_type, var,
2490 build2 (PLUS_EXPR, var_type, var,
2491 fold_convert (var_type,
2492 integer_one_node))),
2493 pre_p);
2495 /* ...and jump back to the loop entry. */
2496 append_to_statement_list (build1 (GOTO_EXPR,
2497 void_type_node,
2498 loop_entry_label),
2499 pre_p);
2501 /* Add the loop exit label. */
2502 append_to_statement_list (build1 (LABEL_EXPR,
2503 void_type_node,
2504 loop_exit_label),
2505 pre_p);
2508 /* A subroutine of gimplify_init_constructor. Generate individual
2509 MODIFY_EXPRs for a CONSTRUCTOR. OBJECT is the LHS against which the
2510 assignments should happen. LIST is the CONSTRUCTOR_ELTS of the
2511 CONSTRUCTOR. CLEARED is true if the entire LHS object has been
2512 zeroed first. */
2514 static void
2515 gimplify_init_ctor_eval (tree object, tree list, tree *pre_p, bool cleared)
2517 tree array_elt_type = NULL;
2519 if (TREE_CODE (TREE_TYPE (object)) == ARRAY_TYPE)
2520 array_elt_type = TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (object)));
2522 for (; list; list = TREE_CHAIN (list))
2524 tree purpose, value, cref, init;
2526 purpose = TREE_PURPOSE (list);
2527 value = TREE_VALUE (list);
2529 /* NULL values are created above for gimplification errors. */
2530 if (value == NULL)
2531 continue;
2533 if (cleared && initializer_zerop (value))
2534 continue;
2536 /* ??? Here's to hoping the front end fills in all of the indices,
2537 so we don't have to figure out what's missing ourselves. */
2538 gcc_assert (purpose);
2540 /* If we have a RANGE_EXPR, we have to build a loop to assign the
2541 whole range. */
2542 if (TREE_CODE (purpose) == RANGE_EXPR)
2544 tree lower = TREE_OPERAND (purpose, 0);
2545 tree upper = TREE_OPERAND (purpose, 1);
2547 /* If the lower bound is equal to upper, just treat it as if
2548 upper was the index. */
2549 if (simple_cst_equal (lower, upper))
2550 purpose = upper;
2551 else
2553 gimplify_init_ctor_eval_range (object, lower, upper, value,
2554 array_elt_type, pre_p, cleared);
2555 continue;
2559 if (array_elt_type)
2561 cref = build (ARRAY_REF, array_elt_type, unshare_expr (object),
2562 purpose, NULL_TREE, NULL_TREE);
2564 else
2565 cref = build (COMPONENT_REF, TREE_TYPE (purpose),
2566 unshare_expr (object), purpose, NULL_TREE);
2568 if (TREE_CODE (value) == CONSTRUCTOR)
2569 gimplify_init_ctor_eval (cref, CONSTRUCTOR_ELTS (value),
2570 pre_p, cleared);
2571 else
2573 init = build (MODIFY_EXPR, TREE_TYPE (cref), cref, value);
2574 gimplify_and_add (init, pre_p);
2579 /* A subroutine of gimplify_modify_expr. Break out elements of a
2580 CONSTRUCTOR used as an initializer into separate MODIFY_EXPRs.
2582 Note that we still need to clear any elements that don't have explicit
2583 initializers, so if not all elements are initialized we keep the
2584 original MODIFY_EXPR, we just remove all of the constructor elements. */
2586 static enum gimplify_status
2587 gimplify_init_constructor (tree *expr_p, tree *pre_p,
2588 tree *post_p, bool want_value)
2590 tree object;
2591 tree ctor = TREE_OPERAND (*expr_p, 1);
2592 tree type = TREE_TYPE (ctor);
2593 enum gimplify_status ret;
2594 tree elt_list;
2596 if (TREE_CODE (ctor) != CONSTRUCTOR)
2597 return GS_UNHANDLED;
2599 ret = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p, post_p,
2600 is_gimple_lvalue, fb_lvalue);
2601 if (ret == GS_ERROR)
2602 return ret;
2603 object = TREE_OPERAND (*expr_p, 0);
2605 elt_list = CONSTRUCTOR_ELTS (ctor);
2607 ret = GS_ALL_DONE;
2608 switch (TREE_CODE (type))
2610 case RECORD_TYPE:
2611 case UNION_TYPE:
2612 case QUAL_UNION_TYPE:
2613 case ARRAY_TYPE:
2615 struct gimplify_init_ctor_preeval_data preeval_data;
2616 HOST_WIDE_INT num_type_elements, num_ctor_elements;
2617 HOST_WIDE_INT num_nonzero_elements, num_nonconstant_elements;
2618 bool cleared;
2620 /* Aggregate types must lower constructors to initialization of
2621 individual elements. The exception is that a CONSTRUCTOR node
2622 with no elements indicates zero-initialization of the whole. */
2623 if (elt_list == NULL)
2624 break;
2626 categorize_ctor_elements (ctor, &num_nonzero_elements,
2627 &num_nonconstant_elements,
2628 &num_ctor_elements, &cleared);
2630 /* If a const aggregate variable is being initialized, then it
2631 should never be a lose to promote the variable to be static. */
2632 if (num_nonconstant_elements == 0
2633 && num_nonzero_elements > 1
2634 && TREE_READONLY (object)
2635 && TREE_CODE (object) == VAR_DECL)
2637 DECL_INITIAL (object) = ctor;
2638 TREE_STATIC (object) = 1;
2639 if (!DECL_NAME (object))
2640 DECL_NAME (object) = create_tmp_var_name ("C");
2641 walk_tree (&DECL_INITIAL (object), force_labels_r, NULL, NULL);
2643 /* ??? C++ doesn't automatically append a .<number> to the
2644 assembler name, and even when it does, it looks a FE private
2645 data structures to figure out what that number should be,
2646 which are not set for this variable. I suppose this is
2647 important for local statics for inline functions, which aren't
2648 "local" in the object file sense. So in order to get a unique
2649 TU-local symbol, we must invoke the lhd version now. */
2650 lhd_set_decl_assembler_name (object);
2652 *expr_p = NULL_TREE;
2653 break;
2656 /* If there are "lots" of initialized elements, and all of them
2657 are valid address constants, then the entire initializer can
2658 be dropped to memory, and then memcpy'd out. */
2659 if (num_nonconstant_elements == 0)
2661 HOST_WIDE_INT size = int_size_in_bytes (type);
2662 unsigned int align;
2664 /* ??? We can still get unbounded array types, at least
2665 from the C++ front end. This seems wrong, but attempt
2666 to work around it for now. */
2667 if (size < 0)
2669 size = int_size_in_bytes (TREE_TYPE (object));
2670 if (size >= 0)
2671 TREE_TYPE (ctor) = type = TREE_TYPE (object);
2674 /* Find the maximum alignment we can assume for the object. */
2675 /* ??? Make use of DECL_OFFSET_ALIGN. */
2676 if (DECL_P (object))
2677 align = DECL_ALIGN (object);
2678 else
2679 align = TYPE_ALIGN (type);
2681 if (size > 0 && !can_move_by_pieces (size, align))
2683 tree new = create_tmp_var_raw (type, "C");
2685 gimple_add_tmp_var (new);
2686 TREE_STATIC (new) = 1;
2687 TREE_READONLY (new) = 1;
2688 DECL_INITIAL (new) = ctor;
2689 if (align > DECL_ALIGN (new))
2691 DECL_ALIGN (new) = align;
2692 DECL_USER_ALIGN (new) = 1;
2694 walk_tree (&DECL_INITIAL (new), force_labels_r, NULL, NULL);
2696 TREE_OPERAND (*expr_p, 1) = new;
2698 /* This is no longer an assignment of a CONSTRUCTOR, but
2699 we still may have processing to do on the LHS. So
2700 pretend we didn't do anything here to let that happen. */
2701 return GS_UNHANDLED;
2705 /* If there are "lots" of initialized elements, even discounting
2706 those that are not address constants (and thus *must* be
2707 computed at runtime), then partition the constructor into
2708 constant and non-constant parts. Block copy the constant
2709 parts in, then generate code for the non-constant parts. */
2710 /* TODO. There's code in cp/typeck.c to do this. */
2712 num_type_elements = count_type_elements (TREE_TYPE (ctor));
2714 /* If there are "lots" of zeros, then block clear the object first. */
2715 if (num_type_elements - num_nonzero_elements > CLEAR_RATIO
2716 && num_nonzero_elements < num_type_elements/4)
2717 cleared = true;
2719 /* ??? This bit ought not be needed. For any element not present
2720 in the initializer, we should simply set them to zero. Except
2721 we'd need to *find* the elements that are not present, and that
2722 requires trickery to avoid quadratic compile-time behavior in
2723 large cases or excessive memory use in small cases. */
2724 else if (num_ctor_elements < num_type_elements)
2725 cleared = true;
2727 if (cleared)
2729 /* Zap the CONSTRUCTOR element list, which simplifies this case.
2730 Note that we still have to gimplify, in order to handle the
2731 case of variable sized types. Avoid shared tree structures. */
2732 CONSTRUCTOR_ELTS (ctor) = NULL_TREE;
2733 object = unshare_expr (object);
2734 gimplify_stmt (expr_p);
2735 append_to_statement_list (*expr_p, pre_p);
2738 /* If we have not block cleared the object, or if there are nonzero
2739 elements in the constructor, add assignments to the individual
2740 scalar fields of the object. */
2741 if (!cleared || num_nonzero_elements > 0)
2743 preeval_data.lhs_base_decl = get_base_address (object);
2744 if (!DECL_P (preeval_data.lhs_base_decl))
2745 preeval_data.lhs_base_decl = NULL;
2746 preeval_data.lhs_alias_set = get_alias_set (object);
2748 gimplify_init_ctor_preeval (&TREE_OPERAND (*expr_p, 1),
2749 pre_p, post_p, &preeval_data);
2750 gimplify_init_ctor_eval (object, elt_list, pre_p, cleared);
2753 *expr_p = NULL_TREE;
2755 break;
2757 case COMPLEX_TYPE:
2759 tree r, i;
2761 /* Extract the real and imaginary parts out of the ctor. */
2762 r = i = NULL_TREE;
2763 if (elt_list)
2765 r = TREE_VALUE (elt_list);
2766 elt_list = TREE_CHAIN (elt_list);
2767 if (elt_list)
2769 i = TREE_VALUE (elt_list);
2770 gcc_assert (!TREE_CHAIN (elt_list));
2773 if (r == NULL || i == NULL)
2775 tree zero = convert (TREE_TYPE (type), integer_zero_node);
2776 if (r == NULL)
2777 r = zero;
2778 if (i == NULL)
2779 i = zero;
2782 /* Complex types have either COMPLEX_CST or COMPLEX_EXPR to
2783 represent creation of a complex value. */
2784 if (TREE_CONSTANT (r) && TREE_CONSTANT (i))
2786 ctor = build_complex (type, r, i);
2787 TREE_OPERAND (*expr_p, 1) = ctor;
2789 else
2791 ctor = build (COMPLEX_EXPR, type, r, i);
2792 TREE_OPERAND (*expr_p, 1) = ctor;
2793 ret = gimplify_expr (&TREE_OPERAND (*expr_p, 1), pre_p, post_p,
2794 rhs_predicate_for (TREE_OPERAND (*expr_p, 0)),
2795 fb_rvalue);
2798 break;
2800 case VECTOR_TYPE:
2801 /* Go ahead and simplify constant constructors to VECTOR_CST. */
2802 if (TREE_CONSTANT (ctor))
2804 tree tem;
2806 /* Even when ctor is constant, it might contain non-*_CST
2807 elements (e.g. { 1.0/0.0 - 1.0/0.0, 0.0 }) and those don't
2808 belong into VECTOR_CST nodes. */
2809 for (tem = elt_list; tem; tem = TREE_CHAIN (tem))
2810 if (! CONSTANT_CLASS_P (TREE_VALUE (tem)))
2811 break;
2813 if (! tem)
2815 TREE_OPERAND (*expr_p, 1) = build_vector (type, elt_list);
2816 break;
2820 /* Vector types use CONSTRUCTOR all the way through gimple
2821 compilation as a general initializer. */
2822 for (; elt_list; elt_list = TREE_CHAIN (elt_list))
2824 enum gimplify_status tret;
2825 tret = gimplify_expr (&TREE_VALUE (elt_list), pre_p, post_p,
2826 is_gimple_val, fb_rvalue);
2827 if (tret == GS_ERROR)
2828 ret = GS_ERROR;
2830 break;
2832 default:
2833 /* So how did we get a CONSTRUCTOR for a scalar type? */
2834 gcc_unreachable ();
2837 if (ret == GS_ERROR)
2838 return GS_ERROR;
2839 else if (want_value)
2841 append_to_statement_list (*expr_p, pre_p);
2842 *expr_p = object;
2843 return GS_OK;
2845 else
2846 return GS_ALL_DONE;
2849 /* Subroutine of gimplify_modify_expr to do simplifications of MODIFY_EXPRs
2850 based on the code of the RHS. We loop for as long as something changes. */
2852 static enum gimplify_status
2853 gimplify_modify_expr_rhs (tree *expr_p, tree *from_p, tree *to_p, tree *pre_p,
2854 tree *post_p, bool want_value)
2856 enum gimplify_status ret = GS_OK;
2858 while (ret != GS_UNHANDLED)
2859 switch (TREE_CODE (*from_p))
2861 case INDIRECT_REF:
2863 /* If we have code like
2865 *(const A*)(A*)&x
2867 where the type of "x" is a (possibly cv-qualified variant
2868 of "A"), treat the entire expression as identical to "x".
2869 This kind of code arises in C++ when an object is bound
2870 to a const reference, and if "x" is a TARGET_EXPR we want
2871 to take advantage of the optimization below. */
2872 tree t = fold_indirect_ref (*from_p);
2873 if (t != *from_p)
2875 *from_p = t;
2876 ret = GS_OK;
2878 else
2879 ret = GS_UNHANDLED;
2880 break;
2883 case TARGET_EXPR:
2885 /* If we are initializing something from a TARGET_EXPR, strip the
2886 TARGET_EXPR and initialize it directly, if possible. This can't
2887 be done if the initializer is void, since that implies that the
2888 temporary is set in some non-trivial way.
2890 ??? What about code that pulls out the temp and uses it
2891 elsewhere? I think that such code never uses the TARGET_EXPR as
2892 an initializer. If I'm wrong, we'll die because the temp won't
2893 have any RTL. In that case, I guess we'll need to replace
2894 references somehow. */
2895 tree init = TARGET_EXPR_INITIAL (*from_p);
2897 if (!VOID_TYPE_P (TREE_TYPE (init)))
2899 *from_p = init;
2900 ret = GS_OK;
2902 else
2903 ret = GS_UNHANDLED;
2905 break;
2907 case COMPOUND_EXPR:
2908 /* Remove any COMPOUND_EXPR in the RHS so the following cases will be
2909 caught. */
2910 gimplify_compound_expr (from_p, pre_p, true);
2911 ret = GS_OK;
2912 break;
2914 case CONSTRUCTOR:
2915 /* If we're initializing from a CONSTRUCTOR, break this into
2916 individual MODIFY_EXPRs. */
2917 return gimplify_init_constructor (expr_p, pre_p, post_p, want_value);
2919 case COND_EXPR:
2920 /* If we're assigning to a non-register type, push the assignment
2921 down into the branches. This is mandatory for ADDRESSABLE types,
2922 since we cannot generate temporaries for such, but it saves a
2923 copy in other cases as well. */
2924 if (!is_gimple_reg_type (TREE_TYPE (*from_p)))
2926 *expr_p = *from_p;
2927 return gimplify_cond_expr (expr_p, pre_p, post_p, *to_p,
2928 fb_rvalue);
2930 else
2931 ret = GS_UNHANDLED;
2932 break;
2934 default:
2935 ret = GS_UNHANDLED;
2936 break;
2939 return ret;
2942 /* Gimplify the MODIFY_EXPR node pointed by EXPR_P.
2944 modify_expr
2945 : varname '=' rhs
2946 | '*' ID '=' rhs
2948 PRE_P points to the list where side effects that must happen before
2949 *EXPR_P should be stored.
2951 POST_P points to the list where side effects that must happen after
2952 *EXPR_P should be stored.
2954 WANT_VALUE is nonzero iff we want to use the value of this expression
2955 in another expression. */
2957 static enum gimplify_status
2958 gimplify_modify_expr (tree *expr_p, tree *pre_p, tree *post_p, bool want_value)
2960 tree *from_p = &TREE_OPERAND (*expr_p, 1);
2961 tree *to_p = &TREE_OPERAND (*expr_p, 0);
2962 enum gimplify_status ret = GS_UNHANDLED;
2964 gcc_assert (TREE_CODE (*expr_p) == MODIFY_EXPR
2965 || TREE_CODE (*expr_p) == INIT_EXPR);
2967 /* The distinction between MODIFY_EXPR and INIT_EXPR is no longer useful. */
2968 if (TREE_CODE (*expr_p) == INIT_EXPR)
2969 TREE_SET_CODE (*expr_p, MODIFY_EXPR);
2971 /* See if any simplifications can be done based on what the RHS is. */
2972 ret = gimplify_modify_expr_rhs (expr_p, from_p, to_p, pre_p, post_p,
2973 want_value);
2974 if (ret != GS_UNHANDLED)
2975 return ret;
2977 /* If the value being copied is of variable width, compute the length
2978 of the copy into a WITH_SIZE_EXPR. Note that we need to do this
2979 before gimplifying any of the operands so that we can resolve any
2980 PLACEHOLDER_EXPRs in the size. Also note that the RTL expander uses
2981 the size of the expression to be copied, not of the destination, so
2982 that is what we must here. */
2983 maybe_with_size_expr (from_p);
2985 ret = gimplify_expr (to_p, pre_p, post_p, is_gimple_lvalue, fb_lvalue);
2986 if (ret == GS_ERROR)
2987 return ret;
2989 ret = gimplify_expr (from_p, pre_p, post_p,
2990 rhs_predicate_for (*to_p), fb_rvalue);
2991 if (ret == GS_ERROR)
2992 return ret;
2994 /* Now see if the above changed *from_p to something we handle specially. */
2995 ret = gimplify_modify_expr_rhs (expr_p, from_p, to_p, pre_p, post_p,
2996 want_value);
2997 if (ret != GS_UNHANDLED)
2998 return ret;
3000 /* If we've got a variable sized assignment between two lvalues (i.e. does
3001 not involve a call), then we can make things a bit more straightforward
3002 by converting the assignment to memcpy or memset. */
3003 if (TREE_CODE (*from_p) == WITH_SIZE_EXPR)
3005 tree from = TREE_OPERAND (*from_p, 0);
3006 tree size = TREE_OPERAND (*from_p, 1);
3008 if (TREE_CODE (from) == CONSTRUCTOR)
3009 return gimplify_modify_expr_to_memset (expr_p, size, want_value);
3010 if (is_gimple_addressable (from))
3012 *from_p = from;
3013 return gimplify_modify_expr_to_memcpy (expr_p, size, want_value);
3017 if (gimplify_ctxp->into_ssa && is_gimple_reg (*to_p))
3019 /* If we've somehow already got an SSA_NAME on the LHS, then
3020 we're probably modifying it twice. Not good. */
3021 gcc_assert (TREE_CODE (*to_p) != SSA_NAME);
3022 *to_p = make_ssa_name (*to_p, *expr_p);
3025 if (want_value)
3027 append_to_statement_list (*expr_p, pre_p);
3028 *expr_p = *to_p;
3029 return GS_OK;
3032 return GS_ALL_DONE;
3035 /* Gimplify a comparison between two variable-sized objects. Do this
3036 with a call to BUILT_IN_MEMCMP. */
3038 static enum gimplify_status
3039 gimplify_variable_sized_compare (tree *expr_p)
3041 tree op0 = TREE_OPERAND (*expr_p, 0);
3042 tree op1 = TREE_OPERAND (*expr_p, 1);
3043 tree args, t, dest;
3045 t = TYPE_SIZE_UNIT (TREE_TYPE (op0));
3046 t = unshare_expr (t);
3047 t = SUBSTITUTE_PLACEHOLDER_IN_EXPR (t, op0);
3048 args = tree_cons (NULL, t, NULL);
3049 t = build_fold_addr_expr (op1);
3050 args = tree_cons (NULL, t, args);
3051 dest = build_fold_addr_expr (op0);
3052 args = tree_cons (NULL, dest, args);
3053 t = implicit_built_in_decls[BUILT_IN_MEMCMP];
3054 t = build_function_call_expr (t, args);
3055 *expr_p
3056 = build (TREE_CODE (*expr_p), TREE_TYPE (*expr_p), t, integer_zero_node);
3058 return GS_OK;
3061 /* Gimplify TRUTH_ANDIF_EXPR and TRUTH_ORIF_EXPR expressions. EXPR_P
3062 points to the expression to gimplify.
3064 Expressions of the form 'a && b' are gimplified to:
3066 a && b ? true : false
3068 gimplify_cond_expr will do the rest.
3070 PRE_P points to the list where side effects that must happen before
3071 *EXPR_P should be stored. */
3073 static enum gimplify_status
3074 gimplify_boolean_expr (tree *expr_p)
3076 /* Preserve the original type of the expression. */
3077 tree type = TREE_TYPE (*expr_p);
3079 *expr_p = build (COND_EXPR, type, *expr_p,
3080 convert (type, boolean_true_node),
3081 convert (type, boolean_false_node));
3083 return GS_OK;
3086 /* Gimplifies an expression sequence. This function gimplifies each
3087 expression and re-writes the original expression with the last
3088 expression of the sequence in GIMPLE form.
3090 PRE_P points to the list where the side effects for all the
3091 expressions in the sequence will be emitted.
3093 WANT_VALUE is true when the result of the last COMPOUND_EXPR is used. */
3094 /* ??? Should rearrange to share the pre-queue with all the indirect
3095 invocations of gimplify_expr. Would probably save on creations
3096 of statement_list nodes. */
3098 static enum gimplify_status
3099 gimplify_compound_expr (tree *expr_p, tree *pre_p, bool want_value)
3101 tree t = *expr_p;
3105 tree *sub_p = &TREE_OPERAND (t, 0);
3107 if (TREE_CODE (*sub_p) == COMPOUND_EXPR)
3108 gimplify_compound_expr (sub_p, pre_p, false);
3109 else
3110 gimplify_stmt (sub_p);
3111 append_to_statement_list (*sub_p, pre_p);
3113 t = TREE_OPERAND (t, 1);
3115 while (TREE_CODE (t) == COMPOUND_EXPR);
3117 *expr_p = t;
3118 if (want_value)
3119 return GS_OK;
3120 else
3122 gimplify_stmt (expr_p);
3123 return GS_ALL_DONE;
3127 /* Gimplifies a statement list. These may be created either by an
3128 enlightened front-end, or by shortcut_cond_expr. */
3130 static enum gimplify_status
3131 gimplify_statement_list (tree *expr_p)
3133 tree_stmt_iterator i = tsi_start (*expr_p);
3135 while (!tsi_end_p (i))
3137 tree t;
3139 gimplify_stmt (tsi_stmt_ptr (i));
3141 t = tsi_stmt (i);
3142 if (t == NULL)
3143 tsi_delink (&i);
3144 else if (TREE_CODE (t) == STATEMENT_LIST)
3146 tsi_link_before (&i, t, TSI_SAME_STMT);
3147 tsi_delink (&i);
3149 else
3150 tsi_next (&i);
3153 return GS_ALL_DONE;
3156 /* Gimplify a SAVE_EXPR node. EXPR_P points to the expression to
3157 gimplify. After gimplification, EXPR_P will point to a new temporary
3158 that holds the original value of the SAVE_EXPR node.
3160 PRE_P points to the list where side effects that must happen before
3161 *EXPR_P should be stored. */
3163 static enum gimplify_status
3164 gimplify_save_expr (tree *expr_p, tree *pre_p, tree *post_p)
3166 enum gimplify_status ret = GS_ALL_DONE;
3167 tree val;
3169 gcc_assert (TREE_CODE (*expr_p) == SAVE_EXPR);
3170 val = TREE_OPERAND (*expr_p, 0);
3172 /* If the SAVE_EXPR has not been resolved, then evaluate it once. */
3173 if (!SAVE_EXPR_RESOLVED_P (*expr_p))
3175 /* The operand may be a void-valued expression such as SAVE_EXPRs
3176 generated by the Java frontend for class initialization. It is
3177 being executed only for its side-effects. */
3178 if (TREE_TYPE (val) == void_type_node)
3180 ret = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p, post_p,
3181 is_gimple_stmt, fb_none);
3182 append_to_statement_list (TREE_OPERAND (*expr_p, 0), pre_p);
3183 val = NULL;
3185 else
3186 val = get_initialized_tmp_var (val, pre_p, post_p);
3188 TREE_OPERAND (*expr_p, 0) = val;
3189 SAVE_EXPR_RESOLVED_P (*expr_p) = 1;
3192 *expr_p = val;
3194 return ret;
3197 /* Re-write the ADDR_EXPR node pointed by EXPR_P
3199 unary_expr
3200 : ...
3201 | '&' varname
3204 PRE_P points to the list where side effects that must happen before
3205 *EXPR_P should be stored.
3207 POST_P points to the list where side effects that must happen after
3208 *EXPR_P should be stored. */
3210 static enum gimplify_status
3211 gimplify_addr_expr (tree *expr_p, tree *pre_p, tree *post_p)
3213 tree expr = *expr_p;
3214 tree op0 = TREE_OPERAND (expr, 0);
3215 enum gimplify_status ret;
3217 switch (TREE_CODE (op0))
3219 case INDIRECT_REF:
3220 case MISALIGNED_INDIRECT_REF:
3221 do_indirect_ref:
3222 /* Check if we are dealing with an expression of the form '&*ptr'.
3223 While the front end folds away '&*ptr' into 'ptr', these
3224 expressions may be generated internally by the compiler (e.g.,
3225 builtins like __builtin_va_end). */
3226 /* Caution: the silent array decomposition semantics we allow for
3227 ADDR_EXPR means we can't always discard the pair. */
3228 /* Gimplification of the ADDR_EXPR operand may drop
3229 cv-qualification conversions, so make sure we add them if
3230 needed. */
3232 tree op00 = TREE_OPERAND (op0, 0);
3233 tree t_expr = TREE_TYPE (expr);
3234 tree t_op00 = TREE_TYPE (op00);
3236 if (!lang_hooks.types_compatible_p (t_expr, t_op00))
3238 #ifdef ENABLE_CHECKING
3239 tree t_op0 = TREE_TYPE (op0);
3240 gcc_assert (POINTER_TYPE_P (t_expr)
3241 && cpt_same_type (TREE_CODE (t_op0) == ARRAY_TYPE
3242 ? TREE_TYPE (t_op0) : t_op0,
3243 TREE_TYPE (t_expr))
3244 && POINTER_TYPE_P (t_op00)
3245 && cpt_same_type (t_op0, TREE_TYPE (t_op00)));
3246 #endif
3247 op00 = fold_convert (TREE_TYPE (expr), op00);
3249 *expr_p = op00;
3250 ret = GS_OK;
3252 break;
3254 case VIEW_CONVERT_EXPR:
3255 /* Take the address of our operand and then convert it to the type of
3256 this ADDR_EXPR.
3258 ??? The interactions of VIEW_CONVERT_EXPR and aliasing is not at
3259 all clear. The impact of this transformation is even less clear. */
3261 /* If the operand is a useless conversion, look through it. Doing so
3262 guarantees that the ADDR_EXPR and its operand will remain of the
3263 same type. */
3264 if (tree_ssa_useless_type_conversion (TREE_OPERAND (op0, 0)))
3265 op0 = TREE_OPERAND (op0, 0);
3267 *expr_p = fold_convert (TREE_TYPE (expr),
3268 build_fold_addr_expr (TREE_OPERAND (op0, 0)));
3269 ret = GS_OK;
3270 break;
3272 default:
3273 /* We use fb_either here because the C frontend sometimes takes
3274 the address of a call that returns a struct; see
3275 gcc.dg/c99-array-lval-1.c. The gimplifier will correctly make
3276 the implied temporary explicit. */
3277 ret = gimplify_expr (&TREE_OPERAND (expr, 0), pre_p, post_p,
3278 is_gimple_addressable, fb_either);
3279 if (ret != GS_ERROR)
3281 op0 = TREE_OPERAND (expr, 0);
3283 /* For various reasons, the gimplification of the expression
3284 may have made a new INDIRECT_REF. */
3285 if (TREE_CODE (op0) == INDIRECT_REF)
3286 goto do_indirect_ref;
3288 /* Make sure TREE_INVARIANT, TREE_CONSTANT, and TREE_SIDE_EFFECTS
3289 is set properly. */
3290 recompute_tree_invarant_for_addr_expr (expr);
3292 /* Mark the RHS addressable. */
3293 lang_hooks.mark_addressable (TREE_OPERAND (expr, 0));
3295 break;
3298 return ret;
3301 /* Gimplify the operands of an ASM_EXPR. Input operands should be a gimple
3302 value; output operands should be a gimple lvalue. */
3304 static enum gimplify_status
3305 gimplify_asm_expr (tree *expr_p, tree *pre_p, tree *post_p)
3307 tree expr = *expr_p;
3308 int noutputs = list_length (ASM_OUTPUTS (expr));
3309 const char **oconstraints
3310 = (const char **) alloca ((noutputs) * sizeof (const char *));
3311 int i;
3312 tree link;
3313 const char *constraint;
3314 bool allows_mem, allows_reg, is_inout;
3315 enum gimplify_status ret, tret;
3317 ret = GS_ALL_DONE;
3318 for (i = 0, link = ASM_OUTPUTS (expr); link; ++i, link = TREE_CHAIN (link))
3320 size_t constraint_len;
3321 oconstraints[i] = constraint
3322 = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (link)));
3323 constraint_len = strlen (constraint);
3324 if (constraint_len == 0)
3325 continue;
3327 parse_output_constraint (&constraint, i, 0, 0,
3328 &allows_mem, &allows_reg, &is_inout);
3330 if (!allows_reg && allows_mem)
3331 lang_hooks.mark_addressable (TREE_VALUE (link));
3333 tret = gimplify_expr (&TREE_VALUE (link), pre_p, post_p,
3334 is_inout ? is_gimple_min_lval : is_gimple_lvalue,
3335 fb_lvalue | fb_mayfail);
3336 if (tret == GS_ERROR)
3338 error ("invalid lvalue in asm output %d", i);
3339 ret = tret;
3342 if (is_inout)
3344 /* An input/output operand. To give the optimizers more
3345 flexibility, split it into separate input and output
3346 operands. */
3347 tree input;
3348 char buf[10];
3350 /* Turn the in/out constraint into an output constraint. */
3351 char *p = xstrdup (constraint);
3352 p[0] = '=';
3353 TREE_VALUE (TREE_PURPOSE (link)) = build_string (constraint_len, p);
3355 /* And add a matching input constraint. */
3356 if (allows_reg)
3358 sprintf (buf, "%d", i);
3360 /* If there are multiple alternatives in the constraint,
3361 handle each of them individually. Those that allow register
3362 will be replaced with operand number, the others will stay
3363 unchanged. */
3364 if (strchr (p, ',') != NULL)
3366 size_t len = 0, buflen = strlen (buf);
3367 char *beg, *end, *str, *dst;
3369 for (beg = p + 1;;)
3371 end = strchr (beg, ',');
3372 if (end == NULL)
3373 end = strchr (beg, '\0');
3374 if ((size_t) (end - beg) < buflen)
3375 len += buflen + 1;
3376 else
3377 len += end - beg + 1;
3378 if (*end)
3379 beg = end + 1;
3380 else
3381 break;
3384 str = alloca (len);
3385 for (beg = p + 1, dst = str;;)
3387 const char *tem;
3388 bool mem_p, reg_p, inout_p;
3390 end = strchr (beg, ',');
3391 if (end)
3392 *end = '\0';
3393 beg[-1] = '=';
3394 tem = beg - 1;
3395 parse_output_constraint (&tem, i, 0, 0,
3396 &mem_p, &reg_p, &inout_p);
3397 if (dst != str)
3398 *dst++ = ',';
3399 if (reg_p)
3401 memcpy (dst, buf, buflen);
3402 dst += buflen;
3404 else
3406 if (end)
3407 len = end - beg;
3408 else
3409 len = strlen (beg);
3410 memcpy (dst, beg, len);
3411 dst += len;
3413 if (end)
3414 beg = end + 1;
3415 else
3416 break;
3418 *dst = '\0';
3419 input = build_string (dst - str, str);
3421 else
3422 input = build_string (strlen (buf), buf);
3424 else
3425 input = build_string (constraint_len - 1, constraint + 1);
3427 free (p);
3429 input = build_tree_list (build_tree_list (NULL_TREE, input),
3430 unshare_expr (TREE_VALUE (link)));
3431 ASM_INPUTS (expr) = chainon (ASM_INPUTS (expr), input);
3435 for (link = ASM_INPUTS (expr); link; ++i, link = TREE_CHAIN (link))
3437 constraint
3438 = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (link)));
3439 parse_input_constraint (&constraint, 0, 0, noutputs, 0,
3440 oconstraints, &allows_mem, &allows_reg);
3442 /* If the operand is a memory input, it should be an lvalue. */
3443 if (!allows_reg && allows_mem)
3445 lang_hooks.mark_addressable (TREE_VALUE (link));
3446 tret = gimplify_expr (&TREE_VALUE (link), pre_p, post_p,
3447 is_gimple_lvalue, fb_lvalue | fb_mayfail);
3448 if (tret == GS_ERROR)
3450 error ("memory input %d is not directly addressable", i);
3451 ret = tret;
3454 else
3456 tret = gimplify_expr (&TREE_VALUE (link), pre_p, post_p,
3457 is_gimple_asm_val, fb_rvalue);
3458 if (tret == GS_ERROR)
3459 ret = tret;
3463 return ret;
3466 /* Gimplify a CLEANUP_POINT_EXPR. Currently this works by adding
3467 WITH_CLEANUP_EXPRs to the prequeue as we encounter cleanups while
3468 gimplifying the body, and converting them to TRY_FINALLY_EXPRs when we
3469 return to this function.
3471 FIXME should we complexify the prequeue handling instead? Or use flags
3472 for all the cleanups and let the optimizer tighten them up? The current
3473 code seems pretty fragile; it will break on a cleanup within any
3474 non-conditional nesting. But any such nesting would be broken, anyway;
3475 we can't write a TRY_FINALLY_EXPR that starts inside a nesting construct
3476 and continues out of it. We can do that at the RTL level, though, so
3477 having an optimizer to tighten up try/finally regions would be a Good
3478 Thing. */
3480 static enum gimplify_status
3481 gimplify_cleanup_point_expr (tree *expr_p, tree *pre_p)
3483 tree_stmt_iterator iter;
3484 tree body;
3486 tree temp = voidify_wrapper_expr (*expr_p, NULL);
3488 /* We only care about the number of conditions between the innermost
3489 CLEANUP_POINT_EXPR and the cleanup. So save and reset the count. */
3490 int old_conds = gimplify_ctxp->conditions;
3491 gimplify_ctxp->conditions = 0;
3493 body = TREE_OPERAND (*expr_p, 0);
3494 gimplify_to_stmt_list (&body);
3496 gimplify_ctxp->conditions = old_conds;
3498 for (iter = tsi_start (body); !tsi_end_p (iter); )
3500 tree *wce_p = tsi_stmt_ptr (iter);
3501 tree wce = *wce_p;
3503 if (TREE_CODE (wce) == WITH_CLEANUP_EXPR)
3505 if (tsi_one_before_end_p (iter))
3507 tsi_link_before (&iter, TREE_OPERAND (wce, 0), TSI_SAME_STMT);
3508 tsi_delink (&iter);
3509 break;
3511 else
3513 tree sl, tfe;
3514 enum tree_code code;
3516 if (CLEANUP_EH_ONLY (wce))
3517 code = TRY_CATCH_EXPR;
3518 else
3519 code = TRY_FINALLY_EXPR;
3521 sl = tsi_split_statement_list_after (&iter);
3522 tfe = build (code, void_type_node, sl, NULL_TREE);
3523 append_to_statement_list (TREE_OPERAND (wce, 0),
3524 &TREE_OPERAND (tfe, 1));
3525 *wce_p = tfe;
3526 iter = tsi_start (sl);
3529 else
3530 tsi_next (&iter);
3533 if (temp)
3535 *expr_p = temp;
3536 append_to_statement_list (body, pre_p);
3537 return GS_OK;
3539 else
3541 *expr_p = body;
3542 return GS_ALL_DONE;
3546 /* Insert a cleanup marker for gimplify_cleanup_point_expr. CLEANUP
3547 is the cleanup action required. */
3549 static void
3550 gimple_push_cleanup (tree var, tree cleanup, bool eh_only, tree *pre_p)
3552 tree wce;
3554 /* Errors can result in improperly nested cleanups. Which results in
3555 confusion when trying to resolve the WITH_CLEANUP_EXPR. */
3556 if (errorcount || sorrycount)
3557 return;
3559 if (gimple_conditional_context ())
3561 /* If we're in a conditional context, this is more complex. We only
3562 want to run the cleanup if we actually ran the initialization that
3563 necessitates it, but we want to run it after the end of the
3564 conditional context. So we wrap the try/finally around the
3565 condition and use a flag to determine whether or not to actually
3566 run the destructor. Thus
3568 test ? f(A()) : 0
3570 becomes (approximately)
3572 flag = 0;
3573 try {
3574 if (test) { A::A(temp); flag = 1; val = f(temp); }
3575 else { val = 0; }
3576 } finally {
3577 if (flag) A::~A(temp);
3582 tree flag = create_tmp_var (boolean_type_node, "cleanup");
3583 tree ffalse = build (MODIFY_EXPR, void_type_node, flag,
3584 boolean_false_node);
3585 tree ftrue = build (MODIFY_EXPR, void_type_node, flag,
3586 boolean_true_node);
3587 cleanup = build (COND_EXPR, void_type_node, flag, cleanup, NULL);
3588 wce = build (WITH_CLEANUP_EXPR, void_type_node, cleanup);
3589 append_to_statement_list (ffalse, &gimplify_ctxp->conditional_cleanups);
3590 append_to_statement_list (wce, &gimplify_ctxp->conditional_cleanups);
3591 append_to_statement_list (ftrue, pre_p);
3593 /* Because of this manipulation, and the EH edges that jump
3594 threading cannot redirect, the temporary (VAR) will appear
3595 to be used uninitialized. Don't warn. */
3596 TREE_NO_WARNING (var) = 1;
3598 else
3600 wce = build (WITH_CLEANUP_EXPR, void_type_node, cleanup);
3601 CLEANUP_EH_ONLY (wce) = eh_only;
3602 append_to_statement_list (wce, pre_p);
3605 gimplify_stmt (&TREE_OPERAND (wce, 0));
3608 /* Gimplify a TARGET_EXPR which doesn't appear on the rhs of an INIT_EXPR. */
3610 static enum gimplify_status
3611 gimplify_target_expr (tree *expr_p, tree *pre_p, tree *post_p)
3613 tree targ = *expr_p;
3614 tree temp = TARGET_EXPR_SLOT (targ);
3615 tree init = TARGET_EXPR_INITIAL (targ);
3616 enum gimplify_status ret;
3618 if (init)
3620 /* TARGET_EXPR temps aren't part of the enclosing block, so add it
3621 to the temps list. */
3622 gimple_add_tmp_var (temp);
3624 /* If TARGET_EXPR_INITIAL is void, then the mere evaluation of the
3625 expression is supposed to initialize the slot. */
3626 if (VOID_TYPE_P (TREE_TYPE (init)))
3627 ret = gimplify_expr (&init, pre_p, post_p, is_gimple_stmt, fb_none);
3628 else
3630 /* Special handling for BIND_EXPR can result in fewer temps. */
3631 ret = GS_OK;
3632 if (TREE_CODE (init) == BIND_EXPR)
3633 gimplify_bind_expr (&init, temp, pre_p);
3634 if (init != temp)
3636 init = build (MODIFY_EXPR, void_type_node, temp, init);
3637 ret = gimplify_expr (&init, pre_p, post_p, is_gimple_stmt,
3638 fb_none);
3641 if (ret == GS_ERROR)
3642 return GS_ERROR;
3643 append_to_statement_list (init, pre_p);
3645 /* If needed, push the cleanup for the temp. */
3646 if (TARGET_EXPR_CLEANUP (targ))
3648 gimplify_stmt (&TARGET_EXPR_CLEANUP (targ));
3649 gimple_push_cleanup (temp, TARGET_EXPR_CLEANUP (targ),
3650 CLEANUP_EH_ONLY (targ), pre_p);
3653 /* Only expand this once. */
3654 TREE_OPERAND (targ, 3) = init;
3655 TARGET_EXPR_INITIAL (targ) = NULL_TREE;
3657 else
3658 /* We should have expanded this before. */
3659 gcc_assert (DECL_SEEN_IN_BIND_EXPR_P (temp));
3661 *expr_p = temp;
3662 return GS_OK;
3665 /* Gimplification of expression trees. */
3667 /* Gimplify an expression which appears at statement context; usually, this
3668 means replacing it with a suitably gimple STATEMENT_LIST. */
3670 void
3671 gimplify_stmt (tree *stmt_p)
3673 gimplify_expr (stmt_p, NULL, NULL, is_gimple_stmt, fb_none);
3676 /* Similarly, but force the result to be a STATEMENT_LIST. */
3678 void
3679 gimplify_to_stmt_list (tree *stmt_p)
3681 gimplify_stmt (stmt_p);
3682 if (!*stmt_p)
3683 *stmt_p = alloc_stmt_list ();
3684 else if (TREE_CODE (*stmt_p) != STATEMENT_LIST)
3686 tree t = *stmt_p;
3687 *stmt_p = alloc_stmt_list ();
3688 append_to_statement_list (t, stmt_p);
3693 /* Gimplifies the expression tree pointed by EXPR_P. Return 0 if
3694 gimplification failed.
3696 PRE_P points to the list where side effects that must happen before
3697 EXPR should be stored.
3699 POST_P points to the list where side effects that must happen after
3700 EXPR should be stored, or NULL if there is no suitable list. In
3701 that case, we copy the result to a temporary, emit the
3702 post-effects, and then return the temporary.
3704 GIMPLE_TEST_F points to a function that takes a tree T and
3705 returns nonzero if T is in the GIMPLE form requested by the
3706 caller. The GIMPLE predicates are in tree-gimple.c.
3708 This test is used twice. Before gimplification, the test is
3709 invoked to determine whether *EXPR_P is already gimple enough. If
3710 that fails, *EXPR_P is gimplified according to its code and
3711 GIMPLE_TEST_F is called again. If the test still fails, then a new
3712 temporary variable is created and assigned the value of the
3713 gimplified expression.
3715 FALLBACK tells the function what sort of a temporary we want. If the 1
3716 bit is set, an rvalue is OK. If the 2 bit is set, an lvalue is OK.
3717 If both are set, either is OK, but an lvalue is preferable.
3719 The return value is either GS_ERROR or GS_ALL_DONE, since this function
3720 iterates until solution. */
3722 enum gimplify_status
3723 gimplify_expr (tree *expr_p, tree *pre_p, tree *post_p,
3724 bool (* gimple_test_f) (tree), fallback_t fallback)
3726 tree tmp;
3727 tree internal_pre = NULL_TREE;
3728 tree internal_post = NULL_TREE;
3729 tree save_expr;
3730 int is_statement = (pre_p == NULL);
3731 location_t saved_location;
3732 enum gimplify_status ret;
3734 save_expr = *expr_p;
3735 if (save_expr == NULL_TREE)
3736 return GS_ALL_DONE;
3738 /* We used to check the predicate here and return immediately if it
3739 succeeds. This is wrong; the design is for gimplification to be
3740 idempotent, and for the predicates to only test for valid forms, not
3741 whether they are fully simplified. */
3743 /* Set up our internal queues if needed. */
3744 if (pre_p == NULL)
3745 pre_p = &internal_pre;
3746 if (post_p == NULL)
3747 post_p = &internal_post;
3749 saved_location = input_location;
3750 if (save_expr != error_mark_node
3751 && EXPR_HAS_LOCATION (*expr_p))
3752 input_location = EXPR_LOCATION (*expr_p);
3754 /* Loop over the specific gimplifiers until the toplevel node
3755 remains the same. */
3758 /* Strip away as many useless type conversions as possible
3759 at the toplevel. */
3760 STRIP_USELESS_TYPE_CONVERSION (*expr_p);
3762 /* Remember the expr. */
3763 save_expr = *expr_p;
3765 /* Die, die, die, my darling. */
3766 if (save_expr == error_mark_node
3767 || (TREE_TYPE (save_expr)
3768 && TREE_TYPE (save_expr) == error_mark_node))
3770 ret = GS_ERROR;
3771 break;
3774 /* Do any language-specific gimplification. */
3775 ret = lang_hooks.gimplify_expr (expr_p, pre_p, post_p);
3776 if (ret == GS_OK)
3778 if (*expr_p == NULL_TREE)
3779 break;
3780 if (*expr_p != save_expr)
3781 continue;
3783 else if (ret != GS_UNHANDLED)
3784 break;
3786 ret = GS_OK;
3787 switch (TREE_CODE (*expr_p))
3789 /* First deal with the special cases. */
3791 case POSTINCREMENT_EXPR:
3792 case POSTDECREMENT_EXPR:
3793 case PREINCREMENT_EXPR:
3794 case PREDECREMENT_EXPR:
3795 ret = gimplify_self_mod_expr (expr_p, pre_p, post_p,
3796 fallback != fb_none);
3797 break;
3799 case ARRAY_REF:
3800 case ARRAY_RANGE_REF:
3801 case REALPART_EXPR:
3802 case IMAGPART_EXPR:
3803 case COMPONENT_REF:
3804 case VIEW_CONVERT_EXPR:
3805 ret = gimplify_compound_lval (expr_p, pre_p, post_p,
3806 fallback ? fallback : fb_rvalue);
3807 break;
3809 case COND_EXPR:
3810 ret = gimplify_cond_expr (expr_p, pre_p, post_p, NULL_TREE,
3811 fallback);
3812 /* C99 code may assign to an array in a structure value of a
3813 conditional expression, and this has undefined behavior
3814 only on execution, so create a temporary if an lvalue is
3815 required. */
3816 if (fallback == fb_lvalue)
3818 *expr_p = get_initialized_tmp_var (*expr_p, pre_p, post_p);
3819 lang_hooks.mark_addressable (*expr_p);
3821 break;
3823 case CALL_EXPR:
3824 ret = gimplify_call_expr (expr_p, pre_p, fallback != fb_none);
3825 /* C99 code may assign to an array in a structure returned
3826 from a function, and this has undefined behavior only on
3827 execution, so create a temporary if an lvalue is
3828 required. */
3829 if (fallback == fb_lvalue)
3831 *expr_p = get_initialized_tmp_var (*expr_p, pre_p, post_p);
3832 lang_hooks.mark_addressable (*expr_p);
3834 break;
3836 case TREE_LIST:
3837 gcc_unreachable ();
3839 case COMPOUND_EXPR:
3840 ret = gimplify_compound_expr (expr_p, pre_p, fallback != fb_none);
3841 break;
3843 case MODIFY_EXPR:
3844 case INIT_EXPR:
3845 ret = gimplify_modify_expr (expr_p, pre_p, post_p,
3846 fallback != fb_none);
3847 break;
3849 case TRUTH_ANDIF_EXPR:
3850 case TRUTH_ORIF_EXPR:
3851 ret = gimplify_boolean_expr (expr_p);
3852 break;
3854 case TRUTH_NOT_EXPR:
3855 TREE_OPERAND (*expr_p, 0)
3856 = gimple_boolify (TREE_OPERAND (*expr_p, 0));
3857 ret = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p, post_p,
3858 is_gimple_val, fb_rvalue);
3859 recalculate_side_effects (*expr_p);
3860 break;
3862 case ADDR_EXPR:
3863 ret = gimplify_addr_expr (expr_p, pre_p, post_p);
3864 break;
3866 case VA_ARG_EXPR:
3867 ret = gimplify_va_arg_expr (expr_p, pre_p, post_p);
3868 break;
3870 case CONVERT_EXPR:
3871 case NOP_EXPR:
3872 if (IS_EMPTY_STMT (*expr_p))
3874 ret = GS_ALL_DONE;
3875 break;
3878 if (VOID_TYPE_P (TREE_TYPE (*expr_p))
3879 || fallback == fb_none)
3881 /* Just strip a conversion to void (or in void context) and
3882 try again. */
3883 *expr_p = TREE_OPERAND (*expr_p, 0);
3884 break;
3887 ret = gimplify_conversion (expr_p);
3888 if (ret == GS_ERROR)
3889 break;
3890 if (*expr_p != save_expr)
3891 break;
3892 /* FALLTHRU */
3894 case FIX_TRUNC_EXPR:
3895 case FIX_CEIL_EXPR:
3896 case FIX_FLOOR_EXPR:
3897 case FIX_ROUND_EXPR:
3898 /* unary_expr: ... | '(' cast ')' val | ... */
3899 ret = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p, post_p,
3900 is_gimple_val, fb_rvalue);
3901 recalculate_side_effects (*expr_p);
3902 break;
3904 case INDIRECT_REF:
3905 *expr_p = fold_indirect_ref (*expr_p);
3906 if (*expr_p != save_expr)
3907 break;
3908 /* else fall through. */
3909 case ALIGN_INDIRECT_REF:
3910 case MISALIGNED_INDIRECT_REF:
3911 ret = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p, post_p,
3912 is_gimple_reg, fb_rvalue);
3913 recalculate_side_effects (*expr_p);
3914 break;
3916 /* Constants need not be gimplified. */
3917 case INTEGER_CST:
3918 case REAL_CST:
3919 case STRING_CST:
3920 case COMPLEX_CST:
3921 case VECTOR_CST:
3922 ret = GS_ALL_DONE;
3923 break;
3925 case CONST_DECL:
3926 /* If we require an lvalue, such as for ADDR_EXPR, retain the
3927 CONST_DECL node. Otherwise the decl is replaceable by its
3928 value. */
3929 /* ??? Should be == fb_lvalue, but ADDR_EXPR passes fb_either. */
3930 if (fallback & fb_lvalue)
3931 ret = GS_ALL_DONE;
3932 else
3933 *expr_p = DECL_INITIAL (*expr_p);
3934 break;
3936 case DECL_EXPR:
3937 ret = gimplify_decl_expr (expr_p);
3938 break;
3940 case EXC_PTR_EXPR:
3941 /* FIXME make this a decl. */
3942 ret = GS_ALL_DONE;
3943 break;
3945 case BIND_EXPR:
3946 ret = gimplify_bind_expr (expr_p, NULL, pre_p);
3947 break;
3949 case LOOP_EXPR:
3950 ret = gimplify_loop_expr (expr_p, pre_p);
3951 break;
3953 case SWITCH_EXPR:
3954 ret = gimplify_switch_expr (expr_p, pre_p);
3955 break;
3957 case EXIT_EXPR:
3958 ret = gimplify_exit_expr (expr_p);
3959 break;
3961 case GOTO_EXPR:
3962 /* If the target is not LABEL, then it is a computed jump
3963 and the target needs to be gimplified. */
3964 if (TREE_CODE (GOTO_DESTINATION (*expr_p)) != LABEL_DECL)
3965 ret = gimplify_expr (&GOTO_DESTINATION (*expr_p), pre_p,
3966 NULL, is_gimple_val, fb_rvalue);
3967 break;
3969 case LABEL_EXPR:
3970 ret = GS_ALL_DONE;
3971 gcc_assert (decl_function_context (LABEL_EXPR_LABEL (*expr_p))
3972 == current_function_decl);
3973 break;
3975 case CASE_LABEL_EXPR:
3976 ret = gimplify_case_label_expr (expr_p);
3977 break;
3979 case RETURN_EXPR:
3980 ret = gimplify_return_expr (*expr_p, pre_p);
3981 break;
3983 case CONSTRUCTOR:
3984 /* Don't reduce this in place; let gimplify_init_constructor work its
3985 magic. Buf if we're just elaborating this for side effects, just
3986 gimplify any element that has side-effects. */
3987 if (fallback == fb_none)
3989 for (tmp = CONSTRUCTOR_ELTS (*expr_p); tmp;
3990 tmp = TREE_CHAIN (tmp))
3991 if (TREE_SIDE_EFFECTS (TREE_VALUE (tmp)))
3992 gimplify_expr (&TREE_VALUE (tmp), pre_p, post_p,
3993 gimple_test_f, fallback);
3995 *expr_p = NULL_TREE;
3998 ret = GS_ALL_DONE;
3999 break;
4001 /* The following are special cases that are not handled by the
4002 original GIMPLE grammar. */
4004 /* SAVE_EXPR nodes are converted into a GIMPLE identifier and
4005 eliminated. */
4006 case SAVE_EXPR:
4007 ret = gimplify_save_expr (expr_p, pre_p, post_p);
4008 break;
4010 case BIT_FIELD_REF:
4012 enum gimplify_status r0, r1, r2;
4014 r0 = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p, post_p,
4015 is_gimple_lvalue, fb_either);
4016 r1 = gimplify_expr (&TREE_OPERAND (*expr_p, 1), pre_p, post_p,
4017 is_gimple_val, fb_rvalue);
4018 r2 = gimplify_expr (&TREE_OPERAND (*expr_p, 2), pre_p, post_p,
4019 is_gimple_val, fb_rvalue);
4020 recalculate_side_effects (*expr_p);
4022 ret = MIN (r0, MIN (r1, r2));
4024 break;
4026 case NON_LVALUE_EXPR:
4027 /* This should have been stripped above. */
4028 gcc_unreachable ();
4030 case ASM_EXPR:
4031 ret = gimplify_asm_expr (expr_p, pre_p, post_p);
4032 break;
4034 case TRY_FINALLY_EXPR:
4035 case TRY_CATCH_EXPR:
4036 gimplify_to_stmt_list (&TREE_OPERAND (*expr_p, 0));
4037 gimplify_to_stmt_list (&TREE_OPERAND (*expr_p, 1));
4038 ret = GS_ALL_DONE;
4039 break;
4041 case CLEANUP_POINT_EXPR:
4042 ret = gimplify_cleanup_point_expr (expr_p, pre_p);
4043 break;
4045 case TARGET_EXPR:
4046 ret = gimplify_target_expr (expr_p, pre_p, post_p);
4047 break;
4049 case CATCH_EXPR:
4050 gimplify_to_stmt_list (&CATCH_BODY (*expr_p));
4051 ret = GS_ALL_DONE;
4052 break;
4054 case EH_FILTER_EXPR:
4055 gimplify_to_stmt_list (&EH_FILTER_FAILURE (*expr_p));
4056 ret = GS_ALL_DONE;
4057 break;
4059 case OBJ_TYPE_REF:
4061 enum gimplify_status r0, r1;
4062 r0 = gimplify_expr (&OBJ_TYPE_REF_OBJECT (*expr_p), pre_p, post_p,
4063 is_gimple_val, fb_rvalue);
4064 r1 = gimplify_expr (&OBJ_TYPE_REF_EXPR (*expr_p), pre_p, post_p,
4065 is_gimple_val, fb_rvalue);
4066 ret = MIN (r0, r1);
4068 break;
4070 case LABEL_DECL:
4071 /* We get here when taking the address of a label. We mark
4072 the label as "forced"; meaning it can never be removed and
4073 it is a potential target for any computed goto. */
4074 FORCED_LABEL (*expr_p) = 1;
4075 ret = GS_ALL_DONE;
4076 break;
4078 case STATEMENT_LIST:
4079 ret = gimplify_statement_list (expr_p);
4080 break;
4082 case WITH_SIZE_EXPR:
4084 gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p,
4085 post_p == &internal_post ? NULL : post_p,
4086 gimple_test_f, fallback);
4087 gimplify_expr (&TREE_OPERAND (*expr_p, 1), pre_p, post_p,
4088 is_gimple_val, fb_rvalue);
4090 break;
4092 case VAR_DECL:
4093 /* ??? If this is a local variable, and it has not been seen in any
4094 outer BIND_EXPR, then it's probably the result of a duplicate
4095 declaration, for which we've already issued an error. It would
4096 be really nice if the front end wouldn't leak these at all.
4097 Currently the only known culprit is C++ destructors, as seen
4098 in g++.old-deja/g++.jason/binding.C. */
4099 tmp = *expr_p;
4100 if (!TREE_STATIC (tmp) && !DECL_EXTERNAL (tmp)
4101 && decl_function_context (tmp) == current_function_decl
4102 && !DECL_SEEN_IN_BIND_EXPR_P (tmp))
4104 gcc_assert (errorcount || sorrycount);
4105 ret = GS_ERROR;
4106 break;
4108 /* FALLTHRU */
4110 case PARM_DECL:
4111 tmp = *expr_p;
4113 /* If this is a local variable sized decl, it must be accessed
4114 indirectly. Perform that substitution. */
4115 if (DECL_VALUE_EXPR (tmp))
4117 *expr_p = unshare_expr (DECL_VALUE_EXPR (tmp));
4118 ret = GS_OK;
4119 break;
4122 ret = GS_ALL_DONE;
4123 break;
4125 case SSA_NAME:
4126 /* Allow callbacks into the gimplifier during optimization. */
4127 ret = GS_ALL_DONE;
4128 break;
4130 default:
4131 switch (TREE_CODE_CLASS (TREE_CODE (*expr_p)))
4133 case tcc_comparison:
4134 /* If this is a comparison of objects of aggregate type,
4135 handle it specially (by converting to a call to
4136 memcmp). It would be nice to only have to do this
4137 for variable-sized objects, but then we'd have to
4138 allow the same nest of reference nodes we allow for
4139 MODIFY_EXPR and that's too complex. */
4140 if (!AGGREGATE_TYPE_P (TREE_TYPE (TREE_OPERAND (*expr_p, 1))))
4141 goto expr_2;
4142 ret = gimplify_variable_sized_compare (expr_p);
4143 break;
4145 /* If *EXPR_P does not need to be special-cased, handle it
4146 according to its class. */
4147 case tcc_unary:
4148 ret = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p,
4149 post_p, is_gimple_val, fb_rvalue);
4150 break;
4152 case tcc_binary:
4153 expr_2:
4155 enum gimplify_status r0, r1;
4157 r0 = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p,
4158 post_p, is_gimple_val, fb_rvalue);
4159 r1 = gimplify_expr (&TREE_OPERAND (*expr_p, 1), pre_p,
4160 post_p, is_gimple_val, fb_rvalue);
4162 ret = MIN (r0, r1);
4163 break;
4166 case tcc_declaration:
4167 case tcc_constant:
4168 ret = GS_ALL_DONE;
4169 goto dont_recalculate;
4171 default:
4172 gcc_assert (TREE_CODE (*expr_p) == TRUTH_AND_EXPR
4173 || TREE_CODE (*expr_p) == TRUTH_OR_EXPR
4174 || TREE_CODE (*expr_p) == TRUTH_XOR_EXPR);
4175 goto expr_2;
4178 recalculate_side_effects (*expr_p);
4179 dont_recalculate:
4180 break;
4183 /* If we replaced *expr_p, gimplify again. */
4184 if (ret == GS_OK && (*expr_p == NULL || *expr_p == save_expr))
4185 ret = GS_ALL_DONE;
4187 while (ret == GS_OK);
4189 /* If we encountered an error_mark somewhere nested inside, either
4190 stub out the statement or propagate the error back out. */
4191 if (ret == GS_ERROR)
4193 if (is_statement)
4194 *expr_p = NULL;
4195 goto out;
4198 /* This was only valid as a return value from the langhook, which
4199 we handled. Make sure it doesn't escape from any other context. */
4200 gcc_assert (ret != GS_UNHANDLED);
4202 if (fallback == fb_none && *expr_p && !is_gimple_stmt (*expr_p))
4204 /* We aren't looking for a value, and we don't have a valid
4205 statement. If it doesn't have side-effects, throw it away. */
4206 if (!TREE_SIDE_EFFECTS (*expr_p))
4207 *expr_p = NULL;
4208 else if (!TREE_THIS_VOLATILE (*expr_p))
4210 /* This is probably a _REF that contains something nested that
4211 has side effects. Recurse through the operands to find it. */
4212 enum tree_code code = TREE_CODE (*expr_p);
4214 switch (code)
4216 case COMPONENT_REF:
4217 case REALPART_EXPR: case IMAGPART_EXPR:
4218 gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p, post_p,
4219 gimple_test_f, fallback);
4220 break;
4222 case ARRAY_REF: case ARRAY_RANGE_REF:
4223 gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p, post_p,
4224 gimple_test_f, fallback);
4225 gimplify_expr (&TREE_OPERAND (*expr_p, 1), pre_p, post_p,
4226 gimple_test_f, fallback);
4227 break;
4229 default:
4230 /* Anything else with side-effects must be converted to
4231 a valid statement before we get here. */
4232 gcc_unreachable ();
4235 *expr_p = NULL;
4237 else if (COMPLETE_TYPE_P (TREE_TYPE (*expr_p)))
4239 /* Historically, the compiler has treated a bare
4240 reference to a volatile lvalue as forcing a load. */
4241 tree tmp = create_tmp_var (TREE_TYPE (*expr_p), "vol");
4242 *expr_p = build (MODIFY_EXPR, TREE_TYPE (tmp), tmp, *expr_p);
4244 else
4245 /* We can't do anything useful with a volatile reference to
4246 incomplete type, so just throw it away. */
4247 *expr_p = NULL;
4250 /* If we are gimplifying at the statement level, we're done. Tack
4251 everything together and replace the original statement with the
4252 gimplified form. */
4253 if (fallback == fb_none || is_statement)
4255 if (internal_pre || internal_post)
4257 append_to_statement_list (*expr_p, &internal_pre);
4258 append_to_statement_list (internal_post, &internal_pre);
4259 annotate_all_with_locus (&internal_pre, input_location);
4260 *expr_p = internal_pre;
4262 else if (!*expr_p)
4264 else if (TREE_CODE (*expr_p) == STATEMENT_LIST)
4265 annotate_all_with_locus (expr_p, input_location);
4266 else
4267 annotate_one_with_locus (*expr_p, input_location);
4268 goto out;
4271 /* Otherwise we're gimplifying a subexpression, so the resulting value is
4272 interesting. */
4274 /* If it's sufficiently simple already, we're done. Unless we are
4275 handling some post-effects internally; if that's the case, we need to
4276 copy into a temp before adding the post-effects to the tree. */
4277 if (!internal_post && (*gimple_test_f) (*expr_p))
4278 goto out;
4280 /* Otherwise, we need to create a new temporary for the gimplified
4281 expression. */
4283 /* We can't return an lvalue if we have an internal postqueue. The
4284 object the lvalue refers to would (probably) be modified by the
4285 postqueue; we need to copy the value out first, which means an
4286 rvalue. */
4287 if ((fallback & fb_lvalue) && !internal_post
4288 && is_gimple_addressable (*expr_p))
4290 /* An lvalue will do. Take the address of the expression, store it
4291 in a temporary, and replace the expression with an INDIRECT_REF of
4292 that temporary. */
4293 tmp = build_fold_addr_expr (*expr_p);
4294 gimplify_expr (&tmp, pre_p, post_p, is_gimple_reg, fb_rvalue);
4295 *expr_p = build1 (INDIRECT_REF, TREE_TYPE (TREE_TYPE (tmp)), tmp);
4297 else if ((fallback & fb_rvalue) && is_gimple_formal_tmp_rhs (*expr_p))
4299 gcc_assert (!VOID_TYPE_P (TREE_TYPE (*expr_p)));
4301 /* An rvalue will do. Assign the gimplified expression into a new
4302 temporary TMP and replace the original expression with TMP. */
4304 if (internal_post || (fallback & fb_lvalue))
4305 /* The postqueue might change the value of the expression between
4306 the initialization and use of the temporary, so we can't use a
4307 formal temp. FIXME do we care? */
4308 *expr_p = get_initialized_tmp_var (*expr_p, pre_p, post_p);
4309 else
4310 *expr_p = get_formal_tmp_var (*expr_p, pre_p);
4312 if (TREE_CODE (*expr_p) != SSA_NAME)
4313 DECL_GIMPLE_FORMAL_TEMP_P (*expr_p) = 1;
4315 else
4317 #ifdef ENABLE_CHECKING
4318 if (!(fallback & fb_mayfail))
4320 fprintf (stderr, "gimplification failed:\n");
4321 print_generic_expr (stderr, *expr_p, 0);
4322 debug_tree (*expr_p);
4323 internal_error ("gimplification failed");
4325 #endif
4326 gcc_assert (fallback & fb_mayfail);
4327 /* If this is an asm statement, and the user asked for the
4328 impossible, don't die. Fail and let gimplify_asm_expr
4329 issue an error. */
4330 ret = GS_ERROR;
4331 goto out;
4334 /* Make sure the temporary matches our predicate. */
4335 gcc_assert ((*gimple_test_f) (*expr_p));
4337 if (internal_post)
4339 annotate_all_with_locus (&internal_post, input_location);
4340 append_to_statement_list (internal_post, pre_p);
4343 out:
4344 input_location = saved_location;
4345 return ret;
4348 /* Look through TYPE for variable-sized objects and gimplify each such
4349 size that we find. Add to LIST_P any statements generated. */
4351 void
4352 gimplify_type_sizes (tree type, tree *list_p)
4354 tree field, t;
4356 /* Note that we do not check for TYPE_SIZES_GIMPLIFIED already set because
4357 that's not supposed to happen on types where gimplification does anything.
4358 We should assert that it isn't set, but we can indeed be called multiple
4359 times on pointers. Unfortunately, this includes fat pointers which we
4360 can't easily test for. We could pass TYPE down to gimplify_one_sizepos
4361 and test there, but it doesn't seem worth it. */
4363 /* We first do the main variant, then copy into any other variants. */
4364 type = TYPE_MAIN_VARIANT (type);
4366 switch (TREE_CODE (type))
4368 case ERROR_MARK:
4369 return;
4371 case INTEGER_TYPE:
4372 case ENUMERAL_TYPE:
4373 case BOOLEAN_TYPE:
4374 case CHAR_TYPE:
4375 case REAL_TYPE:
4376 gimplify_one_sizepos (&TYPE_MIN_VALUE (type), list_p);
4377 gimplify_one_sizepos (&TYPE_MAX_VALUE (type), list_p);
4379 for (t = TYPE_NEXT_VARIANT (type); t; t = TYPE_NEXT_VARIANT (t))
4381 TYPE_MIN_VALUE (t) = TYPE_MIN_VALUE (type);
4382 TYPE_MAX_VALUE (t) = TYPE_MAX_VALUE (type);
4383 TYPE_SIZES_GIMPLIFIED (t) = 1;
4385 break;
4387 case ARRAY_TYPE:
4388 /* These types may not have declarations, so handle them here. */
4389 if (!TYPE_SIZES_GIMPLIFIED (TREE_TYPE (type)))
4390 gimplify_type_sizes (TREE_TYPE (type), list_p);
4392 if (!TYPE_SIZES_GIMPLIFIED (TYPE_DOMAIN (type)))
4393 gimplify_type_sizes (TYPE_DOMAIN (type), list_p);
4394 break;
4396 case RECORD_TYPE:
4397 case UNION_TYPE:
4398 case QUAL_UNION_TYPE:
4399 for (field = TYPE_FIELDS (type); field; field = TREE_CHAIN (field))
4400 if (TREE_CODE (field) == FIELD_DECL)
4401 gimplify_one_sizepos (&DECL_FIELD_OFFSET (field), list_p);
4402 break;
4404 default:
4405 break;
4408 gimplify_one_sizepos (&TYPE_SIZE (type), list_p);
4409 gimplify_one_sizepos (&TYPE_SIZE_UNIT (type), list_p);
4411 for (t = TYPE_NEXT_VARIANT (type); t; t = TYPE_NEXT_VARIANT (t))
4413 TYPE_SIZE (t) = TYPE_SIZE (type);
4414 TYPE_SIZE_UNIT (t) = TYPE_SIZE_UNIT (type);
4415 TYPE_SIZES_GIMPLIFIED (t) = 1;
4418 TYPE_SIZES_GIMPLIFIED (type) = 1;
4421 /* A subroutine of gimplify_type_sizes to make sure that *EXPR_P,
4422 a size or position, has had all of its SAVE_EXPRs evaluated.
4423 We add any required statements to STMT_P. */
4425 void
4426 gimplify_one_sizepos (tree *expr_p, tree *stmt_p)
4428 /* We don't do anything if the value isn't there, is constant, or contains
4429 A PLACEHOLDER_EXPR. We also don't want to do anything if it's already
4430 a VAR_DECL. If it's a VAR_DECL from another function, the gimplifier
4431 will want to replace it with a new variable, but that will cause problems
4432 if this type is from outside the function. It's OK to have that here. */
4433 if (*expr_p == NULL_TREE || TREE_CONSTANT (*expr_p)
4434 || TREE_CODE (*expr_p) == VAR_DECL
4435 || CONTAINS_PLACEHOLDER_P (*expr_p))
4436 return;
4438 *expr_p = unshare_expr (*expr_p);
4439 gimplify_expr (expr_p, stmt_p, NULL, is_gimple_val, fb_rvalue);
4442 #ifdef ENABLE_CHECKING
4443 /* Compare types A and B for a "close enough" match. */
4445 static bool
4446 cpt_same_type (tree a, tree b)
4448 if (lang_hooks.types_compatible_p (a, b))
4449 return true;
4451 /* ??? The C++ FE decomposes METHOD_TYPES to FUNCTION_TYPES and doesn't
4452 link them together. This routine is intended to catch type errors
4453 that will affect the optimizers, and the optimizers don't add new
4454 dereferences of function pointers, so ignore it. */
4455 if ((TREE_CODE (a) == FUNCTION_TYPE || TREE_CODE (a) == METHOD_TYPE)
4456 && (TREE_CODE (b) == FUNCTION_TYPE || TREE_CODE (b) == METHOD_TYPE))
4457 return true;
4459 /* ??? The C FE pushes type qualifiers after the fact into the type of
4460 the element from the type of the array. See build_unary_op's handling
4461 of ADDR_EXPR. This seems wrong -- if we were going to do this, we
4462 should have done it when creating the variable in the first place.
4463 Alternately, why aren't the two array types made variants? */
4464 if (TREE_CODE (a) == ARRAY_TYPE && TREE_CODE (b) == ARRAY_TYPE)
4465 return cpt_same_type (TREE_TYPE (a), TREE_TYPE (b));
4467 /* And because of those, we have to recurse down through pointers. */
4468 if (POINTER_TYPE_P (a) && POINTER_TYPE_P (b))
4469 return cpt_same_type (TREE_TYPE (a), TREE_TYPE (b));
4471 return false;
4474 /* Check for some cases of the front end missing cast expressions.
4475 The type of a dereference should correspond to the pointer type;
4476 similarly the type of an address should match its object. */
4478 static tree
4479 check_pointer_types_r (tree *tp, int *walk_subtrees ATTRIBUTE_UNUSED,
4480 void *data ATTRIBUTE_UNUSED)
4482 tree t = *tp;
4483 tree ptype, otype, dtype;
4485 switch (TREE_CODE (t))
4487 case INDIRECT_REF:
4488 case ARRAY_REF:
4489 otype = TREE_TYPE (t);
4490 ptype = TREE_TYPE (TREE_OPERAND (t, 0));
4491 dtype = TREE_TYPE (ptype);
4492 gcc_assert (cpt_same_type (otype, dtype));
4493 break;
4495 case ADDR_EXPR:
4496 ptype = TREE_TYPE (t);
4497 otype = TREE_TYPE (TREE_OPERAND (t, 0));
4498 dtype = TREE_TYPE (ptype);
4499 if (!cpt_same_type (otype, dtype))
4501 /* &array is allowed to produce a pointer to the element, rather than
4502 a pointer to the array type. We must allow this in order to
4503 properly represent assigning the address of an array in C into
4504 pointer to the element type. */
4505 gcc_assert (TREE_CODE (otype) == ARRAY_TYPE
4506 && POINTER_TYPE_P (ptype)
4507 && cpt_same_type (TREE_TYPE (otype), dtype));
4508 break;
4510 break;
4512 default:
4513 return NULL_TREE;
4517 return NULL_TREE;
4519 #endif
4521 /* Gimplify the body of statements pointed by BODY_P. FNDECL is the
4522 function decl containing BODY. */
4524 void
4525 gimplify_body (tree *body_p, tree fndecl, bool do_parms)
4527 location_t saved_location = input_location;
4528 tree body, parm_stmts;
4530 timevar_push (TV_TREE_GIMPLIFY);
4531 push_gimplify_context ();
4533 /* Unshare most shared trees in the body and in that of any nested functions.
4534 It would seem we don't have to do this for nested functions because
4535 they are supposed to be output and then the outer function gimplified
4536 first, but the g++ front end doesn't always do it that way. */
4537 unshare_body (body_p, fndecl);
4538 unvisit_body (body_p, fndecl);
4540 /* Make sure input_location isn't set to something wierd. */
4541 input_location = DECL_SOURCE_LOCATION (fndecl);
4543 /* Resolve callee-copies. This has to be done before processing
4544 the body so that DECL_VALUE_EXPR gets processed correctly. */
4545 parm_stmts = do_parms ? gimplify_parameters () : NULL;
4547 /* Gimplify the function's body. */
4548 gimplify_stmt (body_p);
4549 body = *body_p;
4551 if (!body)
4552 body = alloc_stmt_list ();
4553 else if (TREE_CODE (body) == STATEMENT_LIST)
4555 tree t = expr_only (*body_p);
4556 if (t)
4557 body = t;
4560 /* If there isn't an outer BIND_EXPR, add one. */
4561 if (TREE_CODE (body) != BIND_EXPR)
4563 tree b = build (BIND_EXPR, void_type_node, NULL_TREE,
4564 NULL_TREE, NULL_TREE);
4565 TREE_SIDE_EFFECTS (b) = 1;
4566 append_to_statement_list_force (body, &BIND_EXPR_BODY (b));
4567 body = b;
4570 /* If we had callee-copies statements, insert them at the beginning
4571 of the function. */
4572 if (parm_stmts)
4574 append_to_statement_list_force (BIND_EXPR_BODY (body), &parm_stmts);
4575 BIND_EXPR_BODY (body) = parm_stmts;
4578 /* Unshare again, in case gimplification was sloppy. */
4579 unshare_all_trees (body);
4581 *body_p = body;
4583 pop_gimplify_context (body);
4585 #ifdef ENABLE_CHECKING
4586 walk_tree (body_p, check_pointer_types_r, NULL, NULL);
4587 #endif
4589 timevar_pop (TV_TREE_GIMPLIFY);
4590 input_location = saved_location;
4593 /* Entry point to the gimplification pass. FNDECL is the FUNCTION_DECL
4594 node for the function we want to gimplify. */
4596 void
4597 gimplify_function_tree (tree fndecl)
4599 tree oldfn;
4601 oldfn = current_function_decl;
4602 current_function_decl = fndecl;
4603 cfun = DECL_STRUCT_FUNCTION (fndecl);
4604 if (cfun == NULL)
4605 allocate_struct_function (fndecl);
4607 gimplify_body (&DECL_SAVED_TREE (fndecl), fndecl, true);
4609 /* If we're instrumenting function entry/exit, then prepend the call to
4610 the entry hook and wrap the whole function in a TRY_FINALLY_EXPR to
4611 catch the exit hook. */
4612 /* ??? Add some way to ignore exceptions for this TFE. */
4613 if (flag_instrument_function_entry_exit
4614 && ! DECL_NO_INSTRUMENT_FUNCTION_ENTRY_EXIT (fndecl))
4616 tree tf, x, bind;
4618 tf = build (TRY_FINALLY_EXPR, void_type_node, NULL, NULL);
4619 TREE_SIDE_EFFECTS (tf) = 1;
4620 x = DECL_SAVED_TREE (fndecl);
4621 append_to_statement_list (x, &TREE_OPERAND (tf, 0));
4622 x = implicit_built_in_decls[BUILT_IN_PROFILE_FUNC_EXIT];
4623 x = build_function_call_expr (x, NULL);
4624 append_to_statement_list (x, &TREE_OPERAND (tf, 1));
4626 bind = build (BIND_EXPR, void_type_node, NULL, NULL, NULL);
4627 TREE_SIDE_EFFECTS (bind) = 1;
4628 x = implicit_built_in_decls[BUILT_IN_PROFILE_FUNC_ENTER];
4629 x = build_function_call_expr (x, NULL);
4630 append_to_statement_list (x, &BIND_EXPR_BODY (bind));
4631 append_to_statement_list (tf, &BIND_EXPR_BODY (bind));
4633 DECL_SAVED_TREE (fndecl) = bind;
4636 current_function_decl = oldfn;
4637 cfun = oldfn ? DECL_STRUCT_FUNCTION (oldfn) : NULL;
4641 /* Expands EXPR to list of gimple statements STMTS. If SIMPLE is true,
4642 force the result to be either ssa_name or an invariant, otherwise
4643 just force it to be a rhs expression. If VAR is not NULL, make the
4644 base variable of the final destination be VAR if suitable. */
4646 tree
4647 force_gimple_operand (tree expr, tree *stmts, bool simple, tree var)
4649 tree t;
4650 enum gimplify_status ret;
4651 gimple_predicate gimple_test_f;
4653 *stmts = NULL_TREE;
4655 if (is_gimple_val (expr))
4656 return expr;
4658 gimple_test_f = simple ? is_gimple_val : is_gimple_reg_rhs;
4660 push_gimplify_context ();
4661 gimplify_ctxp->into_ssa = in_ssa_p;
4663 if (var)
4664 expr = build (MODIFY_EXPR, TREE_TYPE (var), var, expr);
4666 ret = gimplify_expr (&expr, stmts, NULL,
4667 gimple_test_f, fb_rvalue);
4668 gcc_assert (ret != GS_ERROR);
4670 if (referenced_vars)
4672 for (t = gimplify_ctxp->temps; t ; t = TREE_CHAIN (t))
4673 add_referenced_tmp_var (t);
4676 pop_gimplify_context (NULL);
4678 return expr;
4681 /* Invokes force_gimple_operand for EXPR with parameters SIMPLE_P and VAR. If
4682 some statements are produced, emits them before BSI. */
4684 tree
4685 force_gimple_operand_bsi (block_stmt_iterator *bsi, tree expr,
4686 bool simple_p, tree var)
4688 tree stmts;
4690 expr = force_gimple_operand (expr, &stmts, simple_p, var);
4691 if (stmts)
4692 bsi_insert_before (bsi, stmts, BSI_SAME_STMT);
4694 return expr;
4697 #include "gt-gimplify.h"