2005-01-16 Steven G. Kargl <kargls@comcast.net>
[official-gcc.git] / gcc / gimplify.c
blob0c8cc95179b34ad0e9d6c08395a146be3daf6f20
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 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 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 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 abort 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 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 abort 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 varray_type 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.
1431 This array is very memory consuming. Don't even think of making
1432 it VARRAY_TREE. */
1433 VARRAY_GENERIC_PTR_NOGC_INIT (stack, 10, "stack");
1435 /* We can handle anything that get_inner_reference can deal with. */
1436 for (p = expr_p; handled_component_p (*p); p = &TREE_OPERAND (*p, 0))
1437 VARRAY_PUSH_GENERIC_PTR_NOGC (stack, *p);
1439 gcc_assert (VARRAY_ACTIVE_SIZE (stack));
1441 /* Now STACK is a stack of pointers to all the refs we've walked through
1442 and P points to the innermost expression.
1444 Java requires that we elaborated nodes in source order. That
1445 means we must gimplify the inner expression followed by each of
1446 the indices, in order. But we can't gimplify the inner
1447 expression until we deal with any variable bounds, sizes, or
1448 positions in order to deal with PLACEHOLDER_EXPRs.
1450 So we do this in three steps. First we deal with the annotations
1451 for any variables in the components, then we gimplify the base,
1452 then we gimplify any indices, from left to right. */
1453 for (i = VARRAY_ACTIVE_SIZE (stack) - 1; i >= 0; i--)
1455 tree t = VARRAY_GENERIC_PTR_NOGC (stack, i);
1457 if (TREE_CODE (t) == ARRAY_REF || TREE_CODE (t) == ARRAY_RANGE_REF)
1459 /* Gimplify the low bound and element type size and put them into
1460 the ARRAY_REF. If these values are set, they have already been
1461 gimplified. */
1462 if (!TREE_OPERAND (t, 2))
1464 tree low = unshare_expr (array_ref_low_bound (t));
1465 if (!is_gimple_min_invariant (low))
1467 TREE_OPERAND (t, 2) = low;
1468 tret = gimplify_expr (&TREE_OPERAND (t, 2), pre_p, post_p,
1469 is_gimple_formal_tmp_reg, fb_rvalue);
1470 ret = MIN (ret, tret);
1474 if (!TREE_OPERAND (t, 3))
1476 tree elmt_type = TREE_TYPE (TREE_TYPE (TREE_OPERAND (t, 0)));
1477 tree elmt_size = unshare_expr (array_ref_element_size (t));
1478 tree factor = size_int (TYPE_ALIGN_UNIT (elmt_type));
1480 /* Divide the element size by the alignment of the element
1481 type (above). */
1482 elmt_size = size_binop (EXACT_DIV_EXPR, elmt_size, factor);
1484 if (!is_gimple_min_invariant (elmt_size))
1486 TREE_OPERAND (t, 3) = elmt_size;
1487 tret = gimplify_expr (&TREE_OPERAND (t, 3), pre_p, post_p,
1488 is_gimple_formal_tmp_reg, fb_rvalue);
1489 ret = MIN (ret, tret);
1493 else if (TREE_CODE (t) == COMPONENT_REF)
1495 /* Set the field offset into T and gimplify it. */
1496 if (!TREE_OPERAND (t, 2))
1498 tree offset = unshare_expr (component_ref_field_offset (t));
1499 tree field = TREE_OPERAND (t, 1);
1500 tree factor
1501 = size_int (DECL_OFFSET_ALIGN (field) / BITS_PER_UNIT);
1503 /* Divide the offset by its alignment. */
1504 offset = size_binop (EXACT_DIV_EXPR, offset, factor);
1506 if (!is_gimple_min_invariant (offset))
1508 TREE_OPERAND (t, 2) = offset;
1509 tret = gimplify_expr (&TREE_OPERAND (t, 2), pre_p, post_p,
1510 is_gimple_formal_tmp_reg, fb_rvalue);
1511 ret = MIN (ret, tret);
1517 /* Step 2 is to gimplify the base expression. */
1518 tret = gimplify_expr (p, pre_p, post_p, is_gimple_min_lval, fallback);
1519 ret = MIN (ret, tret);
1521 /* And finally, the indices and operands to BIT_FIELD_REF. During this
1522 loop we also remove any useless conversions. */
1523 for (; VARRAY_ACTIVE_SIZE (stack) > 0; )
1525 tree t = VARRAY_TOP_TREE (stack);
1527 if (TREE_CODE (t) == ARRAY_REF || TREE_CODE (t) == ARRAY_RANGE_REF)
1529 /* Gimplify the dimension.
1530 Temporary fix for gcc.c-torture/execute/20040313-1.c.
1531 Gimplify non-constant array indices into a temporary
1532 variable.
1533 FIXME - The real fix is to gimplify post-modify
1534 expressions into a minimal gimple lvalue. However, that
1535 exposes bugs in alias analysis. The alias analyzer does
1536 not handle &PTR->FIELD very well. Will fix after the
1537 branch is merged into mainline (dnovillo 2004-05-03). */
1538 if (!is_gimple_min_invariant (TREE_OPERAND (t, 1)))
1540 tret = gimplify_expr (&TREE_OPERAND (t, 1), pre_p, post_p,
1541 is_gimple_formal_tmp_reg, fb_rvalue);
1542 ret = MIN (ret, tret);
1545 else if (TREE_CODE (t) == BIT_FIELD_REF)
1547 tret = gimplify_expr (&TREE_OPERAND (t, 1), pre_p, post_p,
1548 is_gimple_val, fb_rvalue);
1549 ret = MIN (ret, tret);
1550 tret = gimplify_expr (&TREE_OPERAND (t, 2), pre_p, post_p,
1551 is_gimple_val, fb_rvalue);
1552 ret = MIN (ret, tret);
1555 STRIP_USELESS_TYPE_CONVERSION (TREE_OPERAND (t, 0));
1557 /* The innermost expression P may have originally had TREE_SIDE_EFFECTS
1558 set which would have caused all the outer expressions in EXPR_P
1559 leading to P to also have had TREE_SIDE_EFFECTS set. */
1560 recalculate_side_effects (t);
1561 VARRAY_POP (stack);
1564 tret = gimplify_expr (p, pre_p, post_p, is_gimple_min_lval, fallback);
1565 ret = MIN (ret, tret);
1567 /* If the outermost expression is a COMPONENT_REF, canonicalize its type. */
1568 if ((fallback & fb_rvalue) && TREE_CODE (*expr_p) == COMPONENT_REF)
1570 canonicalize_component_ref (expr_p);
1571 ret = MIN (ret, GS_OK);
1574 VARRAY_FREE (stack);
1576 return ret;
1579 /* Gimplify the self modifying expression pointed by EXPR_P (++, --, +=, -=).
1581 PRE_P points to the list where side effects that must happen before
1582 *EXPR_P should be stored.
1584 POST_P points to the list where side effects that must happen after
1585 *EXPR_P should be stored.
1587 WANT_VALUE is nonzero iff we want to use the value of this expression
1588 in another expression. */
1590 static enum gimplify_status
1591 gimplify_self_mod_expr (tree *expr_p, tree *pre_p, tree *post_p,
1592 bool want_value)
1594 enum tree_code code;
1595 tree lhs, lvalue, rhs, t1;
1596 bool postfix;
1597 enum tree_code arith_code;
1598 enum gimplify_status ret;
1600 code = TREE_CODE (*expr_p);
1602 gcc_assert (code == POSTINCREMENT_EXPR || code == POSTDECREMENT_EXPR
1603 || code == PREINCREMENT_EXPR || code == PREDECREMENT_EXPR);
1605 /* Prefix or postfix? */
1606 if (code == POSTINCREMENT_EXPR || code == POSTDECREMENT_EXPR)
1607 /* Faster to treat as prefix if result is not used. */
1608 postfix = want_value;
1609 else
1610 postfix = false;
1612 /* Add or subtract? */
1613 if (code == PREINCREMENT_EXPR || code == POSTINCREMENT_EXPR)
1614 arith_code = PLUS_EXPR;
1615 else
1616 arith_code = MINUS_EXPR;
1618 /* Gimplify the LHS into a GIMPLE lvalue. */
1619 lvalue = TREE_OPERAND (*expr_p, 0);
1620 ret = gimplify_expr (&lvalue, pre_p, post_p, is_gimple_lvalue, fb_lvalue);
1621 if (ret == GS_ERROR)
1622 return ret;
1624 /* Extract the operands to the arithmetic operation. */
1625 lhs = lvalue;
1626 rhs = TREE_OPERAND (*expr_p, 1);
1628 /* For postfix operator, we evaluate the LHS to an rvalue and then use
1629 that as the result value and in the postqueue operation. */
1630 if (postfix)
1632 ret = gimplify_expr (&lhs, pre_p, post_p, is_gimple_val, fb_rvalue);
1633 if (ret == GS_ERROR)
1634 return ret;
1637 t1 = build (arith_code, TREE_TYPE (*expr_p), lhs, rhs);
1638 t1 = build (MODIFY_EXPR, TREE_TYPE (lvalue), lvalue, t1);
1640 if (postfix)
1642 gimplify_and_add (t1, post_p);
1643 *expr_p = lhs;
1644 return GS_ALL_DONE;
1646 else
1648 *expr_p = t1;
1649 return GS_OK;
1653 /* If *EXPR_P has a variable sized type, wrap it in a WITH_SIZE_EXPR. */
1655 static void
1656 maybe_with_size_expr (tree *expr_p)
1658 tree expr = *expr_p;
1659 tree type = TREE_TYPE (expr);
1660 tree size;
1662 /* If we've already wrapped this or the type is error_mark_node, we can't do
1663 anything. */
1664 if (TREE_CODE (expr) == WITH_SIZE_EXPR
1665 || type == error_mark_node)
1666 return;
1668 /* If the size isn't known or is a constant, we have nothing to do. */
1669 size = TYPE_SIZE_UNIT (type);
1670 if (!size || TREE_CODE (size) == INTEGER_CST)
1671 return;
1673 /* Otherwise, make a WITH_SIZE_EXPR. */
1674 size = unshare_expr (size);
1675 size = SUBSTITUTE_PLACEHOLDER_IN_EXPR (size, expr);
1676 *expr_p = build2 (WITH_SIZE_EXPR, type, expr, size);
1679 /* Subroutine of gimplify_call_expr: Gimplify a single argument. */
1681 static enum gimplify_status
1682 gimplify_arg (tree *expr_p, tree *pre_p)
1684 bool (*test) (tree);
1685 fallback_t fb;
1687 /* In general, we allow lvalues for function arguments to avoid
1688 extra overhead of copying large aggregates out of even larger
1689 aggregates into temporaries only to copy the temporaries to
1690 the argument list. Make optimizers happy by pulling out to
1691 temporaries those types that fit in registers. */
1692 if (is_gimple_reg_type (TREE_TYPE (*expr_p)))
1693 test = is_gimple_val, fb = fb_rvalue;
1694 else
1695 test = is_gimple_lvalue, fb = fb_either;
1697 /* If this is a variable sized type, we must remember the size. */
1698 maybe_with_size_expr (expr_p);
1700 /* There is a sequence point before a function call. Side effects in
1701 the argument list must occur before the actual call. So, when
1702 gimplifying arguments, force gimplify_expr to use an internal
1703 post queue which is then appended to the end of PRE_P. */
1704 return gimplify_expr (expr_p, pre_p, NULL, test, fb);
1707 /* Gimplify the CALL_EXPR node pointed by EXPR_P. PRE_P points to the
1708 list where side effects that must happen before *EXPR_P should be stored.
1709 WANT_VALUE is true if the result of the call is desired. */
1711 static enum gimplify_status
1712 gimplify_call_expr (tree *expr_p, tree *pre_p, bool want_value)
1714 tree decl;
1715 tree arglist;
1716 enum gimplify_status ret;
1718 gcc_assert (TREE_CODE (*expr_p) == CALL_EXPR);
1720 /* For reliable diagnostics during inlining, it is necessary that
1721 every call_expr be annotated with file and line. */
1722 if (! EXPR_HAS_LOCATION (*expr_p))
1723 SET_EXPR_LOCATION (*expr_p, input_location);
1725 /* This may be a call to a builtin function.
1727 Builtin function calls may be transformed into different
1728 (and more efficient) builtin function calls under certain
1729 circumstances. Unfortunately, gimplification can muck things
1730 up enough that the builtin expanders are not aware that certain
1731 transformations are still valid.
1733 So we attempt transformation/gimplification of the call before
1734 we gimplify the CALL_EXPR. At this time we do not manage to
1735 transform all calls in the same manner as the expanders do, but
1736 we do transform most of them. */
1737 decl = get_callee_fndecl (*expr_p);
1738 if (decl && DECL_BUILT_IN (decl))
1740 tree new = fold_builtin (*expr_p, !want_value);
1742 if (new && new != *expr_p)
1744 /* There was a transformation of this call which computes the
1745 same value, but in a more efficient way. Return and try
1746 again. */
1747 *expr_p = new;
1748 return GS_OK;
1751 if (DECL_FUNCTION_CODE (decl) == BUILT_IN_VA_START)
1753 tree arglist = TREE_OPERAND (*expr_p, 1);
1755 if (!arglist || !TREE_CHAIN (arglist))
1757 error ("too few arguments to function %<va_start%>");
1758 *expr_p = build_empty_stmt ();
1759 return GS_OK;
1762 if (fold_builtin_next_arg (TREE_CHAIN (arglist)))
1764 *expr_p = build_empty_stmt ();
1765 return GS_OK;
1767 /* Avoid gimplifying the second argument to va_start, which needs
1768 to be the plain PARM_DECL. */
1769 return gimplify_arg (&TREE_VALUE (TREE_OPERAND (*expr_p, 1)), pre_p);
1773 /* There is a sequence point before the call, so any side effects in
1774 the calling expression must occur before the actual call. Force
1775 gimplify_expr to use an internal post queue. */
1776 ret = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p, NULL,
1777 is_gimple_call_addr, fb_rvalue);
1779 if (PUSH_ARGS_REVERSED)
1780 TREE_OPERAND (*expr_p, 1) = nreverse (TREE_OPERAND (*expr_p, 1));
1781 for (arglist = TREE_OPERAND (*expr_p, 1); arglist;
1782 arglist = TREE_CHAIN (arglist))
1784 enum gimplify_status t;
1786 t = gimplify_arg (&TREE_VALUE (arglist), pre_p);
1788 if (t == GS_ERROR)
1789 ret = GS_ERROR;
1791 if (PUSH_ARGS_REVERSED)
1792 TREE_OPERAND (*expr_p, 1) = nreverse (TREE_OPERAND (*expr_p, 1));
1794 /* Try this again in case gimplification exposed something. */
1795 if (ret != GS_ERROR && decl && DECL_BUILT_IN (decl))
1797 tree new = fold_builtin (*expr_p, !want_value);
1799 if (new && new != *expr_p)
1801 /* There was a transformation of this call which computes the
1802 same value, but in a more efficient way. Return and try
1803 again. */
1804 *expr_p = new;
1805 return GS_OK;
1809 /* If the function is "const" or "pure", then clear TREE_SIDE_EFFECTS on its
1810 decl. This allows us to eliminate redundant or useless
1811 calls to "const" functions. */
1812 if (TREE_CODE (*expr_p) == CALL_EXPR
1813 && (call_expr_flags (*expr_p) & (ECF_CONST | ECF_PURE)))
1814 TREE_SIDE_EFFECTS (*expr_p) = 0;
1816 return ret;
1819 /* Handle shortcut semantics in the predicate operand of a COND_EXPR by
1820 rewriting it into multiple COND_EXPRs, and possibly GOTO_EXPRs.
1822 TRUE_LABEL_P and FALSE_LABEL_P point to the labels to jump to if the
1823 condition is true or false, respectively. If null, we should generate
1824 our own to skip over the evaluation of this specific expression.
1826 This function is the tree equivalent of do_jump.
1828 shortcut_cond_r should only be called by shortcut_cond_expr. */
1830 static tree
1831 shortcut_cond_r (tree pred, tree *true_label_p, tree *false_label_p)
1833 tree local_label = NULL_TREE;
1834 tree t, expr = NULL;
1836 /* OK, it's not a simple case; we need to pull apart the COND_EXPR to
1837 retain the shortcut semantics. Just insert the gotos here;
1838 shortcut_cond_expr will append the real blocks later. */
1839 if (TREE_CODE (pred) == TRUTH_ANDIF_EXPR)
1841 /* Turn if (a && b) into
1843 if (a); else goto no;
1844 if (b) goto yes; else goto no;
1845 (no:) */
1847 if (false_label_p == NULL)
1848 false_label_p = &local_label;
1850 t = shortcut_cond_r (TREE_OPERAND (pred, 0), NULL, false_label_p);
1851 append_to_statement_list (t, &expr);
1853 t = shortcut_cond_r (TREE_OPERAND (pred, 1), true_label_p,
1854 false_label_p);
1855 append_to_statement_list (t, &expr);
1857 else if (TREE_CODE (pred) == TRUTH_ORIF_EXPR)
1859 /* Turn if (a || b) into
1861 if (a) goto yes;
1862 if (b) goto yes; else goto no;
1863 (yes:) */
1865 if (true_label_p == NULL)
1866 true_label_p = &local_label;
1868 t = shortcut_cond_r (TREE_OPERAND (pred, 0), true_label_p, NULL);
1869 append_to_statement_list (t, &expr);
1871 t = shortcut_cond_r (TREE_OPERAND (pred, 1), true_label_p,
1872 false_label_p);
1873 append_to_statement_list (t, &expr);
1875 else if (TREE_CODE (pred) == COND_EXPR)
1877 /* As long as we're messing with gotos, turn if (a ? b : c) into
1878 if (a)
1879 if (b) goto yes; else goto no;
1880 else
1881 if (c) goto yes; else goto no; */
1882 expr = build (COND_EXPR, void_type_node, TREE_OPERAND (pred, 0),
1883 shortcut_cond_r (TREE_OPERAND (pred, 1), true_label_p,
1884 false_label_p),
1885 shortcut_cond_r (TREE_OPERAND (pred, 2), true_label_p,
1886 false_label_p));
1888 else
1890 expr = build (COND_EXPR, void_type_node, pred,
1891 build_and_jump (true_label_p),
1892 build_and_jump (false_label_p));
1895 if (local_label)
1897 t = build1 (LABEL_EXPR, void_type_node, local_label);
1898 append_to_statement_list (t, &expr);
1901 return expr;
1904 static tree
1905 shortcut_cond_expr (tree expr)
1907 tree pred = TREE_OPERAND (expr, 0);
1908 tree then_ = TREE_OPERAND (expr, 1);
1909 tree else_ = TREE_OPERAND (expr, 2);
1910 tree true_label, false_label, end_label, t;
1911 tree *true_label_p;
1912 tree *false_label_p;
1913 bool emit_end, emit_false;
1914 bool then_se = then_ && TREE_SIDE_EFFECTS (then_);
1915 bool else_se = else_ && TREE_SIDE_EFFECTS (else_);
1917 /* First do simple transformations. */
1918 if (!else_se)
1920 /* If there is no 'else', turn (a && b) into if (a) if (b). */
1921 while (TREE_CODE (pred) == TRUTH_ANDIF_EXPR)
1923 TREE_OPERAND (expr, 0) = TREE_OPERAND (pred, 1);
1924 then_ = shortcut_cond_expr (expr);
1925 pred = TREE_OPERAND (pred, 0);
1926 expr = build (COND_EXPR, void_type_node, pred, then_, NULL_TREE);
1929 if (!then_se)
1931 /* If there is no 'then', turn
1932 if (a || b); else d
1933 into
1934 if (a); else if (b); else d. */
1935 while (TREE_CODE (pred) == TRUTH_ORIF_EXPR)
1937 TREE_OPERAND (expr, 0) = TREE_OPERAND (pred, 1);
1938 else_ = shortcut_cond_expr (expr);
1939 pred = TREE_OPERAND (pred, 0);
1940 expr = build (COND_EXPR, void_type_node, pred, NULL_TREE, else_);
1944 /* If we're done, great. */
1945 if (TREE_CODE (pred) != TRUTH_ANDIF_EXPR
1946 && TREE_CODE (pred) != TRUTH_ORIF_EXPR)
1947 return expr;
1949 /* Otherwise we need to mess with gotos. Change
1950 if (a) c; else d;
1952 if (a); else goto no;
1953 c; goto end;
1954 no: d; end:
1955 and recursively gimplify the condition. */
1957 true_label = false_label = end_label = NULL_TREE;
1959 /* If our arms just jump somewhere, hijack those labels so we don't
1960 generate jumps to jumps. */
1962 if (then_
1963 && TREE_CODE (then_) == GOTO_EXPR
1964 && TREE_CODE (GOTO_DESTINATION (then_)) == LABEL_DECL)
1966 true_label = GOTO_DESTINATION (then_);
1967 then_ = NULL;
1968 then_se = false;
1971 if (else_
1972 && TREE_CODE (else_) == GOTO_EXPR
1973 && TREE_CODE (GOTO_DESTINATION (else_)) == LABEL_DECL)
1975 false_label = GOTO_DESTINATION (else_);
1976 else_ = NULL;
1977 else_se = false;
1980 /* If we aren't hijacking a label for the 'then' branch, it falls through. */
1981 if (true_label)
1982 true_label_p = &true_label;
1983 else
1984 true_label_p = NULL;
1986 /* The 'else' branch also needs a label if it contains interesting code. */
1987 if (false_label || else_se)
1988 false_label_p = &false_label;
1989 else
1990 false_label_p = NULL;
1992 /* If there was nothing else in our arms, just forward the label(s). */
1993 if (!then_se && !else_se)
1994 return shortcut_cond_r (pred, true_label_p, false_label_p);
1996 /* If our last subexpression already has a terminal label, reuse it. */
1997 if (else_se)
1998 expr = expr_last (else_);
1999 else if (then_se)
2000 expr = expr_last (then_);
2001 else
2002 expr = NULL;
2003 if (expr && TREE_CODE (expr) == LABEL_EXPR)
2004 end_label = LABEL_EXPR_LABEL (expr);
2006 /* If we don't care about jumping to the 'else' branch, jump to the end
2007 if the condition is false. */
2008 if (!false_label_p)
2009 false_label_p = &end_label;
2011 /* We only want to emit these labels if we aren't hijacking them. */
2012 emit_end = (end_label == NULL_TREE);
2013 emit_false = (false_label == NULL_TREE);
2015 pred = shortcut_cond_r (pred, true_label_p, false_label_p);
2017 expr = NULL;
2018 append_to_statement_list (pred, &expr);
2020 append_to_statement_list (then_, &expr);
2021 if (else_se)
2023 t = build_and_jump (&end_label);
2024 append_to_statement_list (t, &expr);
2025 if (emit_false)
2027 t = build1 (LABEL_EXPR, void_type_node, false_label);
2028 append_to_statement_list (t, &expr);
2030 append_to_statement_list (else_, &expr);
2032 if (emit_end && end_label)
2034 t = build1 (LABEL_EXPR, void_type_node, end_label);
2035 append_to_statement_list (t, &expr);
2038 return expr;
2041 /* EXPR is used in a boolean context; make sure it has BOOLEAN_TYPE. */
2043 static tree
2044 gimple_boolify (tree expr)
2046 tree type = TREE_TYPE (expr);
2048 if (TREE_CODE (type) == BOOLEAN_TYPE)
2049 return expr;
2051 /* If this is the predicate of a COND_EXPR, it might not even be a
2052 truthvalue yet. */
2053 expr = lang_hooks.truthvalue_conversion (expr);
2055 switch (TREE_CODE (expr))
2057 case TRUTH_AND_EXPR:
2058 case TRUTH_OR_EXPR:
2059 case TRUTH_XOR_EXPR:
2060 case TRUTH_ANDIF_EXPR:
2061 case TRUTH_ORIF_EXPR:
2062 /* Also boolify the arguments of truth exprs. */
2063 TREE_OPERAND (expr, 1) = gimple_boolify (TREE_OPERAND (expr, 1));
2064 /* FALLTHRU */
2066 case TRUTH_NOT_EXPR:
2067 TREE_OPERAND (expr, 0) = gimple_boolify (TREE_OPERAND (expr, 0));
2068 /* FALLTHRU */
2070 case EQ_EXPR: case NE_EXPR:
2071 case LE_EXPR: case GE_EXPR: case LT_EXPR: case GT_EXPR:
2072 /* These expressions always produce boolean results. */
2073 TREE_TYPE (expr) = boolean_type_node;
2074 return expr;
2076 default:
2077 /* Other expressions that get here must have boolean values, but
2078 might need to be converted to the appropriate mode. */
2079 return convert (boolean_type_node, expr);
2083 /* Convert the conditional expression pointed by EXPR_P '(p) ? a : b;'
2084 into
2086 if (p) if (p)
2087 t1 = a; a;
2088 else or else
2089 t1 = b; b;
2092 The second form is used when *EXPR_P is of type void.
2094 TARGET is the tree for T1 above.
2096 PRE_P points to the list where side effects that must happen before
2097 *EXPR_P should be stored.
2099 POST_P points to the list where side effects that must happen after
2100 *EXPR_P should be stored. */
2102 static enum gimplify_status
2103 gimplify_cond_expr (tree *expr_p, tree *pre_p, tree *post_p, tree target)
2105 tree expr = *expr_p;
2106 tree tmp, tmp2, type;
2107 enum gimplify_status ret;
2109 type = TREE_TYPE (expr);
2110 if (!type)
2111 TREE_TYPE (expr) = void_type_node;
2113 /* If this COND_EXPR has a value, copy the values into a temporary within
2114 the arms. */
2115 else if (! VOID_TYPE_P (type))
2117 if (target)
2119 ret = gimplify_expr (&target, pre_p, post_p,
2120 is_gimple_min_lval, fb_lvalue);
2121 if (ret != GS_ERROR)
2122 ret = GS_OK;
2123 tmp = target;
2124 tmp2 = unshare_expr (target);
2126 else
2128 tmp2 = tmp = create_tmp_var (TREE_TYPE (expr), "iftmp");
2129 ret = GS_ALL_DONE;
2132 /* Build the then clause, 't1 = a;'. But don't build an assignment
2133 if this branch is void; in C++ it can be, if it's a throw. */
2134 if (TREE_TYPE (TREE_OPERAND (expr, 1)) != void_type_node)
2135 TREE_OPERAND (expr, 1)
2136 = build (MODIFY_EXPR, void_type_node, tmp, TREE_OPERAND (expr, 1));
2138 /* Build the else clause, 't1 = b;'. */
2139 if (TREE_TYPE (TREE_OPERAND (expr, 2)) != void_type_node)
2140 TREE_OPERAND (expr, 2)
2141 = build (MODIFY_EXPR, void_type_node, tmp2, TREE_OPERAND (expr, 2));
2143 TREE_TYPE (expr) = void_type_node;
2144 recalculate_side_effects (expr);
2146 /* Move the COND_EXPR to the prequeue. */
2147 gimplify_and_add (expr, pre_p);
2149 *expr_p = tmp;
2150 return ret;
2153 /* Make sure the condition has BOOLEAN_TYPE. */
2154 TREE_OPERAND (expr, 0) = gimple_boolify (TREE_OPERAND (expr, 0));
2156 /* Break apart && and || conditions. */
2157 if (TREE_CODE (TREE_OPERAND (expr, 0)) == TRUTH_ANDIF_EXPR
2158 || TREE_CODE (TREE_OPERAND (expr, 0)) == TRUTH_ORIF_EXPR)
2160 expr = shortcut_cond_expr (expr);
2162 if (expr != *expr_p)
2164 *expr_p = expr;
2166 /* We can't rely on gimplify_expr to re-gimplify the expanded
2167 form properly, as cleanups might cause the target labels to be
2168 wrapped in a TRY_FINALLY_EXPR. To prevent that, we need to
2169 set up a conditional context. */
2170 gimple_push_condition ();
2171 gimplify_stmt (expr_p);
2172 gimple_pop_condition (pre_p);
2174 return GS_ALL_DONE;
2178 /* Now do the normal gimplification. */
2179 ret = gimplify_expr (&TREE_OPERAND (expr, 0), pre_p, NULL,
2180 is_gimple_condexpr, fb_rvalue);
2182 gimple_push_condition ();
2184 gimplify_to_stmt_list (&TREE_OPERAND (expr, 1));
2185 gimplify_to_stmt_list (&TREE_OPERAND (expr, 2));
2186 recalculate_side_effects (expr);
2188 gimple_pop_condition (pre_p);
2190 if (ret == GS_ERROR)
2192 else if (TREE_SIDE_EFFECTS (TREE_OPERAND (expr, 1)))
2193 ret = GS_ALL_DONE;
2194 else if (TREE_SIDE_EFFECTS (TREE_OPERAND (expr, 2)))
2195 /* Rewrite "if (a); else b" to "if (!a) b" */
2197 TREE_OPERAND (expr, 0) = invert_truthvalue (TREE_OPERAND (expr, 0));
2198 ret = gimplify_expr (&TREE_OPERAND (expr, 0), pre_p, NULL,
2199 is_gimple_condexpr, fb_rvalue);
2201 tmp = TREE_OPERAND (expr, 1);
2202 TREE_OPERAND (expr, 1) = TREE_OPERAND (expr, 2);
2203 TREE_OPERAND (expr, 2) = tmp;
2205 else
2206 /* Both arms are empty; replace the COND_EXPR with its predicate. */
2207 expr = TREE_OPERAND (expr, 0);
2209 *expr_p = expr;
2210 return ret;
2213 /* A subroutine of gimplify_modify_expr. Replace a MODIFY_EXPR with
2214 a call to __builtin_memcpy. */
2216 static enum gimplify_status
2217 gimplify_modify_expr_to_memcpy (tree *expr_p, tree size, bool want_value)
2219 tree args, t, to, to_ptr, from;
2221 to = TREE_OPERAND (*expr_p, 0);
2222 from = TREE_OPERAND (*expr_p, 1);
2224 args = tree_cons (NULL, size, NULL);
2226 t = build_fold_addr_expr (from);
2227 args = tree_cons (NULL, t, args);
2229 to_ptr = build_fold_addr_expr (to);
2230 args = tree_cons (NULL, to_ptr, args);
2231 t = implicit_built_in_decls[BUILT_IN_MEMCPY];
2232 t = build_function_call_expr (t, args);
2234 if (want_value)
2236 t = build1 (NOP_EXPR, TREE_TYPE (to_ptr), t);
2237 t = build1 (INDIRECT_REF, TREE_TYPE (to), t);
2240 *expr_p = t;
2241 return GS_OK;
2244 /* A subroutine of gimplify_modify_expr. Replace a MODIFY_EXPR with
2245 a call to __builtin_memset. In this case we know that the RHS is
2246 a CONSTRUCTOR with an empty element list. */
2248 static enum gimplify_status
2249 gimplify_modify_expr_to_memset (tree *expr_p, tree size, bool want_value)
2251 tree args, t, to, to_ptr;
2253 to = TREE_OPERAND (*expr_p, 0);
2255 args = tree_cons (NULL, size, NULL);
2257 args = tree_cons (NULL, integer_zero_node, args);
2259 to_ptr = build_fold_addr_expr (to);
2260 args = tree_cons (NULL, to_ptr, args);
2261 t = implicit_built_in_decls[BUILT_IN_MEMSET];
2262 t = build_function_call_expr (t, args);
2264 if (want_value)
2266 t = build1 (NOP_EXPR, TREE_TYPE (to_ptr), t);
2267 t = build1 (INDIRECT_REF, TREE_TYPE (to), t);
2270 *expr_p = t;
2271 return GS_OK;
2274 /* A subroutine of gimplify_init_ctor_preeval. Called via walk_tree,
2275 determine, cautiously, if a CONSTRUCTOR overlaps the lhs of an
2276 assignment. Returns non-null if we detect a potential overlap. */
2278 struct gimplify_init_ctor_preeval_data
2280 /* The base decl of the lhs object. May be NULL, in which case we
2281 have to assume the lhs is indirect. */
2282 tree lhs_base_decl;
2284 /* The alias set of the lhs object. */
2285 int lhs_alias_set;
2288 static tree
2289 gimplify_init_ctor_preeval_1 (tree *tp, int *walk_subtrees, void *xdata)
2291 struct gimplify_init_ctor_preeval_data *data
2292 = (struct gimplify_init_ctor_preeval_data *) xdata;
2293 tree t = *tp;
2295 /* If we find the base object, obviously we have overlap. */
2296 if (data->lhs_base_decl == t)
2297 return t;
2299 /* If the constructor component is indirect, determine if we have a
2300 potential overlap with the lhs. The only bits of information we
2301 have to go on at this point are addressability and alias sets. */
2302 if (TREE_CODE (t) == INDIRECT_REF
2303 && (!data->lhs_base_decl || TREE_ADDRESSABLE (data->lhs_base_decl))
2304 && alias_sets_conflict_p (data->lhs_alias_set, get_alias_set (t)))
2305 return t;
2307 if (IS_TYPE_OR_DECL_P (t))
2308 *walk_subtrees = 0;
2309 return NULL;
2312 /* A subroutine of gimplify_init_constructor. Pre-evaluate *EXPR_P,
2313 force values that overlap with the lhs (as described by *DATA)
2314 into temporaries. */
2316 static void
2317 gimplify_init_ctor_preeval (tree *expr_p, tree *pre_p, tree *post_p,
2318 struct gimplify_init_ctor_preeval_data *data)
2320 enum gimplify_status one;
2322 /* If the value is invariant, then there's nothing to pre-evaluate.
2323 But ensure it doesn't have any side-effects since a SAVE_EXPR is
2324 invariant but has side effects and might contain a reference to
2325 the object we're initializing. */
2326 if (TREE_INVARIANT (*expr_p) && !TREE_SIDE_EFFECTS (*expr_p))
2327 return;
2329 /* If the type has non-trivial constructors, we can't pre-evaluate. */
2330 if (TREE_ADDRESSABLE (TREE_TYPE (*expr_p)))
2331 return;
2333 /* Recurse for nested constructors. */
2334 if (TREE_CODE (*expr_p) == CONSTRUCTOR)
2336 tree list;
2337 for (list = CONSTRUCTOR_ELTS (*expr_p); list ; list = TREE_CHAIN (list))
2338 gimplify_init_ctor_preeval (&TREE_VALUE (list), pre_p, post_p, data);
2339 return;
2342 /* We can't preevaluate if the type contains a placeholder. */
2343 if (type_contains_placeholder_p (TREE_TYPE (*expr_p)))
2344 return;
2346 /* Gimplify the constructor element to something appropriate for the rhs
2347 of a MODIFY_EXPR. Given that we know the lhs is an aggregate, we know
2348 the gimplifier will consider this a store to memory. Doing this
2349 gimplification now means that we won't have to deal with complicated
2350 language-specific trees, nor trees like SAVE_EXPR that can induce
2351 exponential search behavior. */
2352 one = gimplify_expr (expr_p, pre_p, post_p, is_gimple_mem_rhs, fb_rvalue);
2353 if (one == GS_ERROR)
2355 *expr_p = NULL;
2356 return;
2359 /* If we gimplified to a bare decl, we can be sure that it doesn't overlap
2360 with the lhs, since "a = { .x=a }" doesn't make sense. This will
2361 always be true for all scalars, since is_gimple_mem_rhs insists on a
2362 temporary variable for them. */
2363 if (DECL_P (*expr_p))
2364 return;
2366 /* If this is of variable size, we have no choice but to assume it doesn't
2367 overlap since we can't make a temporary for it. */
2368 if (!TREE_CONSTANT (TYPE_SIZE (TREE_TYPE (*expr_p))))
2369 return;
2371 /* Otherwise, we must search for overlap ... */
2372 if (!walk_tree (expr_p, gimplify_init_ctor_preeval_1, data, NULL))
2373 return;
2375 /* ... and if found, force the value into a temporary. */
2376 *expr_p = get_formal_tmp_var (*expr_p, pre_p);
2379 /* A subroutine of gimplify_init_ctor_eval. Create a loop for
2380 a RANGE_EXPR in a CONSTRUCTOR for an array.
2382 var = lower;
2383 loop_entry:
2384 object[var] = value;
2385 if (var == upper)
2386 goto loop_exit;
2387 var = var + 1;
2388 goto loop_entry;
2389 loop_exit:
2391 We increment var _after_ the loop exit check because we might otherwise
2392 fail if upper == TYPE_MAX_VALUE (type for upper).
2394 Note that we never have to deal with SAVE_EXPRs here, because this has
2395 already been taken care of for us, in gimplify_init_ctor_preeval(). */
2397 static void gimplify_init_ctor_eval (tree, tree, tree *, bool);
2399 static void
2400 gimplify_init_ctor_eval_range (tree object, tree lower, tree upper,
2401 tree value, tree array_elt_type,
2402 tree *pre_p, bool cleared)
2404 tree loop_entry_label, loop_exit_label;
2405 tree var, var_type, cref;
2407 loop_entry_label = create_artificial_label ();
2408 loop_exit_label = create_artificial_label ();
2410 /* Create and initialize the index variable. */
2411 var_type = TREE_TYPE (upper);
2412 var = create_tmp_var (var_type, NULL);
2413 append_to_statement_list (build2 (MODIFY_EXPR, var_type, var, lower), pre_p);
2415 /* Add the loop entry label. */
2416 append_to_statement_list (build1 (LABEL_EXPR,
2417 void_type_node,
2418 loop_entry_label),
2419 pre_p);
2421 /* Build the reference. */
2422 cref = build4 (ARRAY_REF, array_elt_type, unshare_expr (object),
2423 var, NULL_TREE, NULL_TREE);
2425 /* If we are a constructor, just call gimplify_init_ctor_eval to do
2426 the store. Otherwise just assign value to the reference. */
2428 if (TREE_CODE (value) == CONSTRUCTOR)
2429 /* NB we might have to call ourself recursively through
2430 gimplify_init_ctor_eval if the value is a constructor. */
2431 gimplify_init_ctor_eval (cref, CONSTRUCTOR_ELTS (value),
2432 pre_p, cleared);
2433 else
2434 append_to_statement_list (build2 (MODIFY_EXPR, TREE_TYPE (cref),
2435 cref, value),
2436 pre_p);
2438 /* We exit the loop when the index var is equal to the upper bound. */
2439 gimplify_and_add (build3 (COND_EXPR, void_type_node,
2440 build2 (EQ_EXPR, boolean_type_node,
2441 var, upper),
2442 build1 (GOTO_EXPR,
2443 void_type_node,
2444 loop_exit_label),
2445 NULL_TREE),
2446 pre_p);
2448 /* Otherwise, increment the index var... */
2449 append_to_statement_list (build2 (MODIFY_EXPR, var_type, var,
2450 build2 (PLUS_EXPR, var_type, var,
2451 fold_convert (var_type,
2452 integer_one_node))),
2453 pre_p);
2455 /* ...and jump back to the loop entry. */
2456 append_to_statement_list (build1 (GOTO_EXPR,
2457 void_type_node,
2458 loop_entry_label),
2459 pre_p);
2461 /* Add the loop exit label. */
2462 append_to_statement_list (build1 (LABEL_EXPR,
2463 void_type_node,
2464 loop_exit_label),
2465 pre_p);
2468 /* A subroutine of gimplify_init_constructor. Generate individual
2469 MODIFY_EXPRs for a CONSTRUCTOR. OBJECT is the LHS against which the
2470 assignments should happen. LIST is the CONSTRUCTOR_ELTS of the
2471 CONSTRUCTOR. CLEARED is true if the entire LHS object has been
2472 zeroed first. */
2474 static void
2475 gimplify_init_ctor_eval (tree object, tree list, tree *pre_p, bool cleared)
2477 tree array_elt_type = NULL;
2479 if (TREE_CODE (TREE_TYPE (object)) == ARRAY_TYPE)
2480 array_elt_type = TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (object)));
2482 for (; list; list = TREE_CHAIN (list))
2484 tree purpose, value, cref, init;
2486 purpose = TREE_PURPOSE (list);
2487 value = TREE_VALUE (list);
2489 /* NULL values are created above for gimplification errors. */
2490 if (value == NULL)
2491 continue;
2493 if (cleared && initializer_zerop (value))
2494 continue;
2496 /* ??? Here's to hoping the front end fills in all of the indices,
2497 so we don't have to figure out what's missing ourselves. */
2498 gcc_assert (purpose);
2500 /* If we have a RANGE_EXPR, we have to build a loop to assign the
2501 whole range. */
2502 if (TREE_CODE (purpose) == RANGE_EXPR)
2504 tree lower = TREE_OPERAND (purpose, 0);
2505 tree upper = TREE_OPERAND (purpose, 1);
2507 /* If the lower bound is equal to upper, just treat it as if
2508 upper was the index. */
2509 if (simple_cst_equal (lower, upper))
2510 purpose = upper;
2511 else
2513 gimplify_init_ctor_eval_range (object, lower, upper, value,
2514 array_elt_type, pre_p, cleared);
2515 continue;
2519 if (array_elt_type)
2521 cref = build (ARRAY_REF, array_elt_type, unshare_expr (object),
2522 purpose, NULL_TREE, NULL_TREE);
2524 else
2525 cref = build (COMPONENT_REF, TREE_TYPE (purpose),
2526 unshare_expr (object), purpose, NULL_TREE);
2528 if (TREE_CODE (value) == CONSTRUCTOR)
2529 gimplify_init_ctor_eval (cref, CONSTRUCTOR_ELTS (value),
2530 pre_p, cleared);
2531 else
2533 init = build (MODIFY_EXPR, TREE_TYPE (cref), cref, value);
2534 gimplify_and_add (init, pre_p);
2539 /* A subroutine of gimplify_modify_expr. Break out elements of a
2540 CONSTRUCTOR used as an initializer into separate MODIFY_EXPRs.
2542 Note that we still need to clear any elements that don't have explicit
2543 initializers, so if not all elements are initialized we keep the
2544 original MODIFY_EXPR, we just remove all of the constructor elements. */
2546 static enum gimplify_status
2547 gimplify_init_constructor (tree *expr_p, tree *pre_p,
2548 tree *post_p, bool want_value)
2550 tree object;
2551 tree ctor = TREE_OPERAND (*expr_p, 1);
2552 tree type = TREE_TYPE (ctor);
2553 enum gimplify_status ret;
2554 tree elt_list;
2556 if (TREE_CODE (ctor) != CONSTRUCTOR)
2557 return GS_UNHANDLED;
2559 ret = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p, post_p,
2560 is_gimple_lvalue, fb_lvalue);
2561 if (ret == GS_ERROR)
2562 return ret;
2563 object = TREE_OPERAND (*expr_p, 0);
2565 elt_list = CONSTRUCTOR_ELTS (ctor);
2567 ret = GS_ALL_DONE;
2568 switch (TREE_CODE (type))
2570 case RECORD_TYPE:
2571 case UNION_TYPE:
2572 case QUAL_UNION_TYPE:
2573 case ARRAY_TYPE:
2575 struct gimplify_init_ctor_preeval_data preeval_data;
2576 HOST_WIDE_INT num_type_elements, num_ctor_elements;
2577 HOST_WIDE_INT num_nonzero_elements, num_nonconstant_elements;
2578 bool cleared;
2580 /* Aggregate types must lower constructors to initialization of
2581 individual elements. The exception is that a CONSTRUCTOR node
2582 with no elements indicates zero-initialization of the whole. */
2583 if (elt_list == NULL)
2584 break;
2586 categorize_ctor_elements (ctor, &num_nonzero_elements,
2587 &num_nonconstant_elements,
2588 &num_ctor_elements);
2590 /* If a const aggregate variable is being initialized, then it
2591 should never be a lose to promote the variable to be static. */
2592 if (num_nonconstant_elements == 0
2593 && TREE_READONLY (object)
2594 && TREE_CODE (object) == VAR_DECL)
2596 DECL_INITIAL (object) = ctor;
2597 TREE_STATIC (object) = 1;
2598 if (!DECL_NAME (object))
2599 DECL_NAME (object) = create_tmp_var_name ("C");
2600 walk_tree (&DECL_INITIAL (object), force_labels_r, NULL, NULL);
2602 /* ??? C++ doesn't automatically append a .<number> to the
2603 assembler name, and even when it does, it looks a FE private
2604 data structures to figure out what that number should be,
2605 which are not set for this variable. I suppose this is
2606 important for local statics for inline functions, which aren't
2607 "local" in the object file sense. So in order to get a unique
2608 TU-local symbol, we must invoke the lhd version now. */
2609 lhd_set_decl_assembler_name (object);
2611 *expr_p = NULL_TREE;
2612 break;
2615 /* If there are "lots" of initialized elements, and all of them
2616 are valid address constants, then the entire initializer can
2617 be dropped to memory, and then memcpy'd out. */
2618 if (num_nonconstant_elements == 0)
2620 HOST_WIDE_INT size = int_size_in_bytes (type);
2621 unsigned int align;
2623 /* ??? We can still get unbounded array types, at least
2624 from the C++ front end. This seems wrong, but attempt
2625 to work around it for now. */
2626 if (size < 0)
2628 size = int_size_in_bytes (TREE_TYPE (object));
2629 if (size >= 0)
2630 TREE_TYPE (ctor) = type = TREE_TYPE (object);
2633 /* Find the maximum alignment we can assume for the object. */
2634 /* ??? Make use of DECL_OFFSET_ALIGN. */
2635 if (DECL_P (object))
2636 align = DECL_ALIGN (object);
2637 else
2638 align = TYPE_ALIGN (type);
2640 if (size > 0 && !can_move_by_pieces (size, align))
2642 tree new = create_tmp_var_raw (type, "C");
2644 gimple_add_tmp_var (new);
2645 TREE_STATIC (new) = 1;
2646 TREE_READONLY (new) = 1;
2647 DECL_INITIAL (new) = ctor;
2648 if (align > DECL_ALIGN (new))
2650 DECL_ALIGN (new) = align;
2651 DECL_USER_ALIGN (new) = 1;
2653 walk_tree (&DECL_INITIAL (new), force_labels_r, NULL, NULL);
2655 TREE_OPERAND (*expr_p, 1) = new;
2657 /* This is no longer an assignment of a CONSTRUCTOR, but
2658 we still may have processing to do on the LHS. So
2659 pretend we didn't do anything here to let that happen. */
2660 return GS_UNHANDLED;
2664 /* If there are "lots" of initialized elements, even discounting
2665 those that are not address constants (and thus *must* be
2666 computed at runtime), then partition the constructor into
2667 constant and non-constant parts. Block copy the constant
2668 parts in, then generate code for the non-constant parts. */
2669 /* TODO. There's code in cp/typeck.c to do this. */
2671 num_type_elements = count_type_elements (TREE_TYPE (ctor));
2673 /* If there are "lots" of zeros, then block clear the object first. */
2674 cleared = false;
2675 if (num_type_elements - num_nonzero_elements > CLEAR_RATIO
2676 && num_nonzero_elements < num_type_elements/4)
2677 cleared = true;
2679 /* ??? This bit ought not be needed. For any element not present
2680 in the initializer, we should simply set them to zero. Except
2681 we'd need to *find* the elements that are not present, and that
2682 requires trickery to avoid quadratic compile-time behavior in
2683 large cases or excessive memory use in small cases. */
2684 else if (num_ctor_elements < num_type_elements)
2685 cleared = true;
2687 if (cleared)
2689 /* Zap the CONSTRUCTOR element list, which simplifies this case.
2690 Note that we still have to gimplify, in order to handle the
2691 case of variable sized types. Avoid shared tree structures. */
2692 CONSTRUCTOR_ELTS (ctor) = NULL_TREE;
2693 object = unshare_expr (object);
2694 gimplify_stmt (expr_p);
2695 append_to_statement_list (*expr_p, pre_p);
2698 /* If we have not block cleared the object, or if there are nonzero
2699 elements in the constructor, add assignments to the individual
2700 scalar fields of the object. */
2701 if (!cleared || num_nonzero_elements > 0)
2703 preeval_data.lhs_base_decl = get_base_address (object);
2704 if (!DECL_P (preeval_data.lhs_base_decl))
2705 preeval_data.lhs_base_decl = NULL;
2706 preeval_data.lhs_alias_set = get_alias_set (object);
2708 gimplify_init_ctor_preeval (&TREE_OPERAND (*expr_p, 1),
2709 pre_p, post_p, &preeval_data);
2710 gimplify_init_ctor_eval (object, elt_list, pre_p, cleared);
2713 *expr_p = NULL_TREE;
2715 break;
2717 case COMPLEX_TYPE:
2719 tree r, i;
2721 /* Extract the real and imaginary parts out of the ctor. */
2722 r = i = NULL_TREE;
2723 if (elt_list)
2725 r = TREE_VALUE (elt_list);
2726 elt_list = TREE_CHAIN (elt_list);
2727 if (elt_list)
2729 i = TREE_VALUE (elt_list);
2730 gcc_assert (!TREE_CHAIN (elt_list));
2733 if (r == NULL || i == NULL)
2735 tree zero = convert (TREE_TYPE (type), integer_zero_node);
2736 if (r == NULL)
2737 r = zero;
2738 if (i == NULL)
2739 i = zero;
2742 /* Complex types have either COMPLEX_CST or COMPLEX_EXPR to
2743 represent creation of a complex value. */
2744 if (TREE_CONSTANT (r) && TREE_CONSTANT (i))
2746 ctor = build_complex (type, r, i);
2747 TREE_OPERAND (*expr_p, 1) = ctor;
2749 else
2751 ctor = build (COMPLEX_EXPR, type, r, i);
2752 TREE_OPERAND (*expr_p, 1) = ctor;
2753 ret = gimplify_expr (&TREE_OPERAND (*expr_p, 1), pre_p, post_p,
2754 rhs_predicate_for (TREE_OPERAND (*expr_p, 0)),
2755 fb_rvalue);
2758 break;
2760 case VECTOR_TYPE:
2761 /* Go ahead and simplify constant constructors to VECTOR_CST. */
2762 if (TREE_CONSTANT (ctor))
2763 TREE_OPERAND (*expr_p, 1) = build_vector (type, elt_list);
2764 else
2766 /* Vector types use CONSTRUCTOR all the way through gimple
2767 compilation as a general initializer. */
2768 for (; elt_list; elt_list = TREE_CHAIN (elt_list))
2770 enum gimplify_status tret;
2771 tret = gimplify_expr (&TREE_VALUE (elt_list), pre_p, post_p,
2772 is_gimple_val, fb_rvalue);
2773 if (tret == GS_ERROR)
2774 ret = GS_ERROR;
2777 break;
2779 default:
2780 /* So how did we get a CONSTRUCTOR for a scalar type? */
2781 gcc_unreachable ();
2784 if (ret == GS_ERROR)
2785 return GS_ERROR;
2786 else if (want_value)
2788 append_to_statement_list (*expr_p, pre_p);
2789 *expr_p = object;
2790 return GS_OK;
2792 else
2793 return GS_ALL_DONE;
2796 /* Subroutine of gimplify_modify_expr to do simplifications of MODIFY_EXPRs
2797 based on the code of the RHS. We loop for as long as something changes. */
2799 static enum gimplify_status
2800 gimplify_modify_expr_rhs (tree *expr_p, tree *from_p, tree *to_p, tree *pre_p,
2801 tree *post_p, bool want_value)
2803 enum gimplify_status ret = GS_OK;
2805 while (ret != GS_UNHANDLED)
2806 switch (TREE_CODE (*from_p))
2808 case INDIRECT_REF:
2810 /* If we have code like
2812 *(const A*)(A*)&x
2814 where the type of "x" is a (possibly cv-qualified variant
2815 of "A"), treat the entire expression as identical to "x".
2816 This kind of code arises in C++ when an object is bound
2817 to a const reference, and if "x" is a TARGET_EXPR we want
2818 to take advantage of the optimization below. */
2819 tree pointer;
2821 pointer = TREE_OPERAND (*from_p, 0);
2822 STRIP_NOPS (pointer);
2823 if (TREE_CODE (pointer) == ADDR_EXPR
2824 && (lang_hooks.types_compatible_p
2825 (TREE_TYPE (TREE_OPERAND (pointer, 0)),
2826 TREE_TYPE (*from_p))))
2828 *from_p = TREE_OPERAND (pointer, 0);
2829 ret = GS_OK;
2831 else
2832 ret = GS_UNHANDLED;
2833 break;
2836 case TARGET_EXPR:
2838 /* If we are initializing something from a TARGET_EXPR, strip the
2839 TARGET_EXPR and initialize it directly, if possible. This can't
2840 be done if the initializer is void, since that implies that the
2841 temporary is set in some non-trivial way.
2843 ??? What about code that pulls out the temp and uses it
2844 elsewhere? I think that such code never uses the TARGET_EXPR as
2845 an initializer. If I'm wrong, we'll abort because the temp won't
2846 have any RTL. In that case, I guess we'll need to replace
2847 references somehow. */
2848 tree init = TARGET_EXPR_INITIAL (*from_p);
2850 if (!VOID_TYPE_P (TREE_TYPE (init)))
2852 *from_p = init;
2853 ret = GS_OK;
2855 else
2856 ret = GS_UNHANDLED;
2858 break;
2860 case COMPOUND_EXPR:
2861 /* Remove any COMPOUND_EXPR in the RHS so the following cases will be
2862 caught. */
2863 gimplify_compound_expr (from_p, pre_p, true);
2864 ret = GS_OK;
2865 break;
2867 case CONSTRUCTOR:
2868 /* If we're initializing from a CONSTRUCTOR, break this into
2869 individual MODIFY_EXPRs. */
2870 return gimplify_init_constructor (expr_p, pre_p, post_p, want_value);
2872 case COND_EXPR:
2873 /* If we're assigning to a non-register type, push the assignment
2874 down into the branches. This is mandatory for ADDRESSABLE types,
2875 since we cannot generate temporaries for such, but it saves a
2876 copy in other cases as well. */
2877 if (!is_gimple_reg_type (TREE_TYPE (*from_p)))
2879 *expr_p = *from_p;
2880 return gimplify_cond_expr (expr_p, pre_p, post_p, *to_p);
2882 else
2883 ret = GS_UNHANDLED;
2884 break;
2886 default:
2887 ret = GS_UNHANDLED;
2888 break;
2891 return ret;
2894 /* Gimplify the MODIFY_EXPR node pointed by EXPR_P.
2896 modify_expr
2897 : varname '=' rhs
2898 | '*' ID '=' rhs
2900 PRE_P points to the list where side effects that must happen before
2901 *EXPR_P should be stored.
2903 POST_P points to the list where side effects that must happen after
2904 *EXPR_P should be stored.
2906 WANT_VALUE is nonzero iff we want to use the value of this expression
2907 in another expression. */
2909 static enum gimplify_status
2910 gimplify_modify_expr (tree *expr_p, tree *pre_p, tree *post_p, bool want_value)
2912 tree *from_p = &TREE_OPERAND (*expr_p, 1);
2913 tree *to_p = &TREE_OPERAND (*expr_p, 0);
2914 enum gimplify_status ret = GS_UNHANDLED;
2916 gcc_assert (TREE_CODE (*expr_p) == MODIFY_EXPR
2917 || TREE_CODE (*expr_p) == INIT_EXPR);
2919 /* The distinction between MODIFY_EXPR and INIT_EXPR is no longer useful. */
2920 if (TREE_CODE (*expr_p) == INIT_EXPR)
2921 TREE_SET_CODE (*expr_p, MODIFY_EXPR);
2923 /* See if any simplifications can be done based on what the RHS is. */
2924 ret = gimplify_modify_expr_rhs (expr_p, from_p, to_p, pre_p, post_p,
2925 want_value);
2926 if (ret != GS_UNHANDLED)
2927 return ret;
2929 /* If the value being copied is of variable width, compute the length
2930 of the copy into a WITH_SIZE_EXPR. Note that we need to do this
2931 before gimplifying any of the operands so that we can resolve any
2932 PLACEHOLDER_EXPRs in the size. Also note that the RTL expander uses
2933 the size of the expression to be copied, not of the destination, so
2934 that is what we must here. */
2935 maybe_with_size_expr (from_p);
2937 ret = gimplify_expr (to_p, pre_p, post_p, is_gimple_lvalue, fb_lvalue);
2938 if (ret == GS_ERROR)
2939 return ret;
2941 ret = gimplify_expr (from_p, pre_p, post_p,
2942 rhs_predicate_for (*to_p), fb_rvalue);
2943 if (ret == GS_ERROR)
2944 return ret;
2946 /* Now see if the above changed *from_p to something we handle specially. */
2947 ret = gimplify_modify_expr_rhs (expr_p, from_p, to_p, pre_p, post_p,
2948 want_value);
2949 if (ret != GS_UNHANDLED)
2950 return ret;
2952 /* If we've got a variable sized assignment between two lvalues (i.e. does
2953 not involve a call), then we can make things a bit more straightforward
2954 by converting the assignment to memcpy or memset. */
2955 if (TREE_CODE (*from_p) == WITH_SIZE_EXPR)
2957 tree from = TREE_OPERAND (*from_p, 0);
2958 tree size = TREE_OPERAND (*from_p, 1);
2960 if (TREE_CODE (from) == CONSTRUCTOR)
2961 return gimplify_modify_expr_to_memset (expr_p, size, want_value);
2962 if (is_gimple_addressable (from))
2964 *from_p = from;
2965 return gimplify_modify_expr_to_memcpy (expr_p, size, want_value);
2969 if (gimplify_ctxp->into_ssa && is_gimple_reg (*to_p))
2971 /* If we've somehow already got an SSA_NAME on the LHS, then
2972 we're probably modifying it twice. Not good. */
2973 gcc_assert (TREE_CODE (*to_p) != SSA_NAME);
2974 *to_p = make_ssa_name (*to_p, *expr_p);
2977 if (want_value)
2979 append_to_statement_list (*expr_p, pre_p);
2980 *expr_p = *to_p;
2981 return GS_OK;
2984 return GS_ALL_DONE;
2987 /* Gimplify a comparison between two variable-sized objects. Do this
2988 with a call to BUILT_IN_MEMCMP. */
2990 static enum gimplify_status
2991 gimplify_variable_sized_compare (tree *expr_p)
2993 tree op0 = TREE_OPERAND (*expr_p, 0);
2994 tree op1 = TREE_OPERAND (*expr_p, 1);
2995 tree args, t, dest;
2997 t = TYPE_SIZE_UNIT (TREE_TYPE (op0));
2998 t = unshare_expr (t);
2999 t = SUBSTITUTE_PLACEHOLDER_IN_EXPR (t, op0);
3000 args = tree_cons (NULL, t, NULL);
3001 t = build_fold_addr_expr (op1);
3002 args = tree_cons (NULL, t, args);
3003 dest = build_fold_addr_expr (op0);
3004 args = tree_cons (NULL, dest, args);
3005 t = implicit_built_in_decls[BUILT_IN_MEMCMP];
3006 t = build_function_call_expr (t, args);
3007 *expr_p
3008 = build (TREE_CODE (*expr_p), TREE_TYPE (*expr_p), t, integer_zero_node);
3010 return GS_OK;
3013 /* Gimplify TRUTH_ANDIF_EXPR and TRUTH_ORIF_EXPR expressions. EXPR_P
3014 points to the expression to gimplify.
3016 Expressions of the form 'a && b' are gimplified to:
3018 a && b ? true : false
3020 gimplify_cond_expr will do the rest.
3022 PRE_P points to the list where side effects that must happen before
3023 *EXPR_P should be stored. */
3025 static enum gimplify_status
3026 gimplify_boolean_expr (tree *expr_p)
3028 /* Preserve the original type of the expression. */
3029 tree type = TREE_TYPE (*expr_p);
3031 *expr_p = build (COND_EXPR, type, *expr_p,
3032 convert (type, boolean_true_node),
3033 convert (type, boolean_false_node));
3035 return GS_OK;
3038 /* Gimplifies an expression sequence. This function gimplifies each
3039 expression and re-writes the original expression with the last
3040 expression of the sequence in GIMPLE form.
3042 PRE_P points to the list where the side effects for all the
3043 expressions in the sequence will be emitted.
3045 WANT_VALUE is true when the result of the last COMPOUND_EXPR is used. */
3046 /* ??? Should rearrange to share the pre-queue with all the indirect
3047 invocations of gimplify_expr. Would probably save on creations
3048 of statement_list nodes. */
3050 static enum gimplify_status
3051 gimplify_compound_expr (tree *expr_p, tree *pre_p, bool want_value)
3053 tree t = *expr_p;
3057 tree *sub_p = &TREE_OPERAND (t, 0);
3059 if (TREE_CODE (*sub_p) == COMPOUND_EXPR)
3060 gimplify_compound_expr (sub_p, pre_p, false);
3061 else
3062 gimplify_stmt (sub_p);
3063 append_to_statement_list (*sub_p, pre_p);
3065 t = TREE_OPERAND (t, 1);
3067 while (TREE_CODE (t) == COMPOUND_EXPR);
3069 *expr_p = t;
3070 if (want_value)
3071 return GS_OK;
3072 else
3074 gimplify_stmt (expr_p);
3075 return GS_ALL_DONE;
3079 /* Gimplifies a statement list. These may be created either by an
3080 enlightened front-end, or by shortcut_cond_expr. */
3082 static enum gimplify_status
3083 gimplify_statement_list (tree *expr_p)
3085 tree_stmt_iterator i = tsi_start (*expr_p);
3087 while (!tsi_end_p (i))
3089 tree t;
3091 gimplify_stmt (tsi_stmt_ptr (i));
3093 t = tsi_stmt (i);
3094 if (t == NULL)
3095 tsi_delink (&i);
3096 else if (TREE_CODE (t) == STATEMENT_LIST)
3098 tsi_link_before (&i, t, TSI_SAME_STMT);
3099 tsi_delink (&i);
3101 else
3102 tsi_next (&i);
3105 return GS_ALL_DONE;
3108 /* Gimplify a SAVE_EXPR node. EXPR_P points to the expression to
3109 gimplify. After gimplification, EXPR_P will point to a new temporary
3110 that holds the original value of the SAVE_EXPR node.
3112 PRE_P points to the list where side effects that must happen before
3113 *EXPR_P should be stored. */
3115 static enum gimplify_status
3116 gimplify_save_expr (tree *expr_p, tree *pre_p, tree *post_p)
3118 enum gimplify_status ret = GS_ALL_DONE;
3119 tree val;
3121 gcc_assert (TREE_CODE (*expr_p) == SAVE_EXPR);
3122 val = TREE_OPERAND (*expr_p, 0);
3124 /* If the SAVE_EXPR has not been resolved, then evaluate it once. */
3125 if (!SAVE_EXPR_RESOLVED_P (*expr_p))
3127 /* The operand may be a void-valued expression such as SAVE_EXPRs
3128 generated by the Java frontend for class initialization. It is
3129 being executed only for its side-effects. */
3130 if (TREE_TYPE (val) == void_type_node)
3132 ret = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p, post_p,
3133 is_gimple_stmt, fb_none);
3134 append_to_statement_list (TREE_OPERAND (*expr_p, 0), pre_p);
3135 val = NULL;
3137 else
3138 val = get_initialized_tmp_var (val, pre_p, post_p);
3140 TREE_OPERAND (*expr_p, 0) = val;
3141 SAVE_EXPR_RESOLVED_P (*expr_p) = 1;
3144 *expr_p = val;
3146 return ret;
3149 /* Re-write the ADDR_EXPR node pointed by EXPR_P
3151 unary_expr
3152 : ...
3153 | '&' varname
3156 PRE_P points to the list where side effects that must happen before
3157 *EXPR_P should be stored.
3159 POST_P points to the list where side effects that must happen after
3160 *EXPR_P should be stored. */
3162 static enum gimplify_status
3163 gimplify_addr_expr (tree *expr_p, tree *pre_p, tree *post_p)
3165 tree expr = *expr_p;
3166 tree op0 = TREE_OPERAND (expr, 0);
3167 enum gimplify_status ret;
3169 switch (TREE_CODE (op0))
3171 case INDIRECT_REF:
3172 case MISALIGNED_INDIRECT_REF:
3173 do_indirect_ref:
3174 /* Check if we are dealing with an expression of the form '&*ptr'.
3175 While the front end folds away '&*ptr' into 'ptr', these
3176 expressions may be generated internally by the compiler (e.g.,
3177 builtins like __builtin_va_end). */
3178 /* Caution: the silent array decomposition semantics we allow for
3179 ADDR_EXPR means we can't always discard the pair. */
3181 tree op00 = TREE_OPERAND (op0, 0);
3182 tree t_expr = TREE_TYPE (expr);
3183 tree t_op00 = TREE_TYPE (op00);
3185 if (!lang_hooks.types_compatible_p (t_expr, t_op00))
3187 #ifdef ENABLE_CHECKING
3188 tree t_op0 = TREE_TYPE (op0);
3189 gcc_assert (TREE_CODE (t_op0) == ARRAY_TYPE
3190 && POINTER_TYPE_P (t_expr)
3191 && cpt_same_type (TREE_TYPE (t_op0),
3192 TREE_TYPE (t_expr))
3193 && POINTER_TYPE_P (t_op00)
3194 && cpt_same_type (t_op0, TREE_TYPE (t_op00)));
3195 #endif
3196 op00 = fold_convert (TREE_TYPE (expr), op00);
3198 *expr_p = op00;
3199 ret = GS_OK;
3201 break;
3203 case VIEW_CONVERT_EXPR:
3204 /* Take the address of our operand and then convert it to the type of
3205 this ADDR_EXPR.
3207 ??? The interactions of VIEW_CONVERT_EXPR and aliasing is not at
3208 all clear. The impact of this transformation is even less clear. */
3210 /* If the operand is a useless conversion, look through it. Doing so
3211 guarantees that the ADDR_EXPR and its operand will remain of the
3212 same type. */
3213 if (tree_ssa_useless_type_conversion (TREE_OPERAND (op0, 0)))
3214 op0 = TREE_OPERAND (op0, 0);
3216 *expr_p = fold_convert (TREE_TYPE (expr),
3217 build_fold_addr_expr (TREE_OPERAND (op0, 0)));
3218 ret = GS_OK;
3219 break;
3221 default:
3222 /* We use fb_either here because the C frontend sometimes takes
3223 the address of a call that returns a struct; see
3224 gcc.dg/c99-array-lval-1.c. The gimplifier will correctly make
3225 the implied temporary explicit. */
3226 ret = gimplify_expr (&TREE_OPERAND (expr, 0), pre_p, post_p,
3227 is_gimple_addressable, fb_either);
3228 if (ret != GS_ERROR)
3230 op0 = TREE_OPERAND (expr, 0);
3232 /* For various reasons, the gimplification of the expression
3233 may have made a new INDIRECT_REF. */
3234 if (TREE_CODE (op0) == INDIRECT_REF)
3235 goto do_indirect_ref;
3237 /* Make sure TREE_INVARIANT, TREE_CONSTANT, and TREE_SIDE_EFFECTS
3238 is set properly. */
3239 recompute_tree_invarant_for_addr_expr (expr);
3241 /* Mark the RHS addressable. */
3242 lang_hooks.mark_addressable (TREE_OPERAND (expr, 0));
3244 break;
3247 return ret;
3250 /* Gimplify the operands of an ASM_EXPR. Input operands should be a gimple
3251 value; output operands should be a gimple lvalue. */
3253 static enum gimplify_status
3254 gimplify_asm_expr (tree *expr_p, tree *pre_p, tree *post_p)
3256 tree expr = *expr_p;
3257 int noutputs = list_length (ASM_OUTPUTS (expr));
3258 const char **oconstraints
3259 = (const char **) alloca ((noutputs) * sizeof (const char *));
3260 int i;
3261 tree link;
3262 const char *constraint;
3263 bool allows_mem, allows_reg, is_inout;
3264 enum gimplify_status ret, tret;
3266 ret = GS_ALL_DONE;
3267 for (i = 0, link = ASM_OUTPUTS (expr); link; ++i, link = TREE_CHAIN (link))
3269 size_t constraint_len;
3270 oconstraints[i] = constraint
3271 = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (link)));
3272 constraint_len = strlen (constraint);
3273 if (constraint_len == 0)
3274 continue;
3276 parse_output_constraint (&constraint, i, 0, 0,
3277 &allows_mem, &allows_reg, &is_inout);
3279 if (!allows_reg && allows_mem)
3280 lang_hooks.mark_addressable (TREE_VALUE (link));
3282 tret = gimplify_expr (&TREE_VALUE (link), pre_p, post_p,
3283 is_inout ? is_gimple_min_lval : is_gimple_lvalue,
3284 fb_lvalue | fb_mayfail);
3285 if (tret == GS_ERROR)
3287 error ("invalid lvalue in asm output %d", i);
3288 ret = tret;
3291 if (is_inout)
3293 /* An input/output operand. To give the optimizers more
3294 flexibility, split it into separate input and output
3295 operands. */
3296 tree input;
3297 char buf[10];
3299 /* Turn the in/out constraint into an output constraint. */
3300 char *p = xstrdup (constraint);
3301 p[0] = '=';
3302 TREE_VALUE (TREE_PURPOSE (link)) = build_string (constraint_len, p);
3303 free (p);
3305 /* And add a matching input constraint. */
3306 if (allows_reg)
3308 sprintf (buf, "%d", i);
3309 input = build_string (strlen (buf), buf);
3311 else
3312 input = build_string (constraint_len - 1, constraint + 1);
3313 input = build_tree_list (build_tree_list (NULL_TREE, input),
3314 unshare_expr (TREE_VALUE (link)));
3315 ASM_INPUTS (expr) = chainon (ASM_INPUTS (expr), input);
3319 for (link = ASM_INPUTS (expr); link; ++i, link = TREE_CHAIN (link))
3321 constraint
3322 = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (link)));
3323 parse_input_constraint (&constraint, 0, 0, noutputs, 0,
3324 oconstraints, &allows_mem, &allows_reg);
3326 /* If the operand is a memory input, it should be an lvalue. */
3327 if (!allows_reg && allows_mem)
3329 lang_hooks.mark_addressable (TREE_VALUE (link));
3330 tret = gimplify_expr (&TREE_VALUE (link), pre_p, post_p,
3331 is_gimple_lvalue, fb_lvalue | fb_mayfail);
3332 if (tret == GS_ERROR)
3334 error ("memory input %d is not directly addressable", i);
3335 ret = tret;
3338 else
3340 tret = gimplify_expr (&TREE_VALUE (link), pre_p, post_p,
3341 is_gimple_asm_val, fb_rvalue);
3342 if (tret == GS_ERROR)
3343 ret = tret;
3347 return ret;
3350 /* Gimplify a CLEANUP_POINT_EXPR. Currently this works by adding
3351 WITH_CLEANUP_EXPRs to the prequeue as we encounter cleanups while
3352 gimplifying the body, and converting them to TRY_FINALLY_EXPRs when we
3353 return to this function.
3355 FIXME should we complexify the prequeue handling instead? Or use flags
3356 for all the cleanups and let the optimizer tighten them up? The current
3357 code seems pretty fragile; it will break on a cleanup within any
3358 non-conditional nesting. But any such nesting would be broken, anyway;
3359 we can't write a TRY_FINALLY_EXPR that starts inside a nesting construct
3360 and continues out of it. We can do that at the RTL level, though, so
3361 having an optimizer to tighten up try/finally regions would be a Good
3362 Thing. */
3364 static enum gimplify_status
3365 gimplify_cleanup_point_expr (tree *expr_p, tree *pre_p)
3367 tree_stmt_iterator iter;
3368 tree body;
3370 tree temp = voidify_wrapper_expr (*expr_p, NULL);
3372 /* We only care about the number of conditions between the innermost
3373 CLEANUP_POINT_EXPR and the cleanup. So save and reset the count. */
3374 int old_conds = gimplify_ctxp->conditions;
3375 gimplify_ctxp->conditions = 0;
3377 body = TREE_OPERAND (*expr_p, 0);
3378 gimplify_to_stmt_list (&body);
3380 gimplify_ctxp->conditions = old_conds;
3382 for (iter = tsi_start (body); !tsi_end_p (iter); )
3384 tree *wce_p = tsi_stmt_ptr (iter);
3385 tree wce = *wce_p;
3387 if (TREE_CODE (wce) == WITH_CLEANUP_EXPR)
3389 if (tsi_one_before_end_p (iter))
3391 tsi_link_before (&iter, TREE_OPERAND (wce, 0), TSI_SAME_STMT);
3392 tsi_delink (&iter);
3393 break;
3395 else
3397 tree sl, tfe;
3398 enum tree_code code;
3400 if (CLEANUP_EH_ONLY (wce))
3401 code = TRY_CATCH_EXPR;
3402 else
3403 code = TRY_FINALLY_EXPR;
3405 sl = tsi_split_statement_list_after (&iter);
3406 tfe = build (code, void_type_node, sl, NULL_TREE);
3407 append_to_statement_list (TREE_OPERAND (wce, 0),
3408 &TREE_OPERAND (tfe, 1));
3409 *wce_p = tfe;
3410 iter = tsi_start (sl);
3413 else
3414 tsi_next (&iter);
3417 if (temp)
3419 *expr_p = temp;
3420 append_to_statement_list (body, pre_p);
3421 return GS_OK;
3423 else
3425 *expr_p = body;
3426 return GS_ALL_DONE;
3430 /* Insert a cleanup marker for gimplify_cleanup_point_expr. CLEANUP
3431 is the cleanup action required. */
3433 static void
3434 gimple_push_cleanup (tree var, tree cleanup, bool eh_only, tree *pre_p)
3436 tree wce;
3438 /* Errors can result in improperly nested cleanups. Which results in
3439 confusion when trying to resolve the WITH_CLEANUP_EXPR. */
3440 if (errorcount || sorrycount)
3441 return;
3443 if (gimple_conditional_context ())
3445 /* If we're in a conditional context, this is more complex. We only
3446 want to run the cleanup if we actually ran the initialization that
3447 necessitates it, but we want to run it after the end of the
3448 conditional context. So we wrap the try/finally around the
3449 condition and use a flag to determine whether or not to actually
3450 run the destructor. Thus
3452 test ? f(A()) : 0
3454 becomes (approximately)
3456 flag = 0;
3457 try {
3458 if (test) { A::A(temp); flag = 1; val = f(temp); }
3459 else { val = 0; }
3460 } finally {
3461 if (flag) A::~A(temp);
3466 tree flag = create_tmp_var (boolean_type_node, "cleanup");
3467 tree ffalse = build (MODIFY_EXPR, void_type_node, flag,
3468 boolean_false_node);
3469 tree ftrue = build (MODIFY_EXPR, void_type_node, flag,
3470 boolean_true_node);
3471 cleanup = build (COND_EXPR, void_type_node, flag, cleanup, NULL);
3472 wce = build (WITH_CLEANUP_EXPR, void_type_node, cleanup);
3473 append_to_statement_list (ffalse, &gimplify_ctxp->conditional_cleanups);
3474 append_to_statement_list (wce, &gimplify_ctxp->conditional_cleanups);
3475 append_to_statement_list (ftrue, pre_p);
3477 /* Because of this manipulation, and the EH edges that jump
3478 threading cannot redirect, the temporary (VAR) will appear
3479 to be used uninitialized. Don't warn. */
3480 TREE_NO_WARNING (var) = 1;
3482 else
3484 wce = build (WITH_CLEANUP_EXPR, void_type_node, cleanup);
3485 CLEANUP_EH_ONLY (wce) = eh_only;
3486 append_to_statement_list (wce, pre_p);
3489 gimplify_stmt (&TREE_OPERAND (wce, 0));
3492 /* Gimplify a TARGET_EXPR which doesn't appear on the rhs of an INIT_EXPR. */
3494 static enum gimplify_status
3495 gimplify_target_expr (tree *expr_p, tree *pre_p, tree *post_p)
3497 tree targ = *expr_p;
3498 tree temp = TARGET_EXPR_SLOT (targ);
3499 tree init = TARGET_EXPR_INITIAL (targ);
3500 enum gimplify_status ret;
3502 if (init)
3504 /* TARGET_EXPR temps aren't part of the enclosing block, so add it
3505 to the temps list. */
3506 gimple_add_tmp_var (temp);
3508 /* If TARGET_EXPR_INITIAL is void, then the mere evaluation of the
3509 expression is supposed to initialize the slot. */
3510 if (VOID_TYPE_P (TREE_TYPE (init)))
3511 ret = gimplify_expr (&init, pre_p, post_p, is_gimple_stmt, fb_none);
3512 else
3514 /* Special handling for BIND_EXPR can result in fewer temps. */
3515 ret = GS_OK;
3516 if (TREE_CODE (init) == BIND_EXPR)
3517 gimplify_bind_expr (&init, temp, pre_p);
3518 if (init != temp)
3520 init = build (MODIFY_EXPR, void_type_node, temp, init);
3521 ret = gimplify_expr (&init, pre_p, post_p, is_gimple_stmt,
3522 fb_none);
3525 if (ret == GS_ERROR)
3526 return GS_ERROR;
3527 append_to_statement_list (init, pre_p);
3529 /* If needed, push the cleanup for the temp. */
3530 if (TARGET_EXPR_CLEANUP (targ))
3532 gimplify_stmt (&TARGET_EXPR_CLEANUP (targ));
3533 gimple_push_cleanup (temp, TARGET_EXPR_CLEANUP (targ),
3534 CLEANUP_EH_ONLY (targ), pre_p);
3537 /* Only expand this once. */
3538 TREE_OPERAND (targ, 3) = init;
3539 TARGET_EXPR_INITIAL (targ) = NULL_TREE;
3541 else
3542 /* We should have expanded this before. */
3543 gcc_assert (DECL_SEEN_IN_BIND_EXPR_P (temp));
3545 *expr_p = temp;
3546 return GS_OK;
3549 /* Gimplification of expression trees. */
3551 /* Gimplify an expression which appears at statement context; usually, this
3552 means replacing it with a suitably gimple STATEMENT_LIST. */
3554 void
3555 gimplify_stmt (tree *stmt_p)
3557 gimplify_expr (stmt_p, NULL, NULL, is_gimple_stmt, fb_none);
3560 /* Similarly, but force the result to be a STATEMENT_LIST. */
3562 void
3563 gimplify_to_stmt_list (tree *stmt_p)
3565 gimplify_stmt (stmt_p);
3566 if (!*stmt_p)
3567 *stmt_p = alloc_stmt_list ();
3568 else if (TREE_CODE (*stmt_p) != STATEMENT_LIST)
3570 tree t = *stmt_p;
3571 *stmt_p = alloc_stmt_list ();
3572 append_to_statement_list (t, stmt_p);
3577 /* Gimplifies the expression tree pointed by EXPR_P. Return 0 if
3578 gimplification failed.
3580 PRE_P points to the list where side effects that must happen before
3581 EXPR should be stored.
3583 POST_P points to the list where side effects that must happen after
3584 EXPR should be stored, or NULL if there is no suitable list. In
3585 that case, we copy the result to a temporary, emit the
3586 post-effects, and then return the temporary.
3588 GIMPLE_TEST_F points to a function that takes a tree T and
3589 returns nonzero if T is in the GIMPLE form requested by the
3590 caller. The GIMPLE predicates are in tree-gimple.c.
3592 This test is used twice. Before gimplification, the test is
3593 invoked to determine whether *EXPR_P is already gimple enough. If
3594 that fails, *EXPR_P is gimplified according to its code and
3595 GIMPLE_TEST_F is called again. If the test still fails, then a new
3596 temporary variable is created and assigned the value of the
3597 gimplified expression.
3599 FALLBACK tells the function what sort of a temporary we want. If the 1
3600 bit is set, an rvalue is OK. If the 2 bit is set, an lvalue is OK.
3601 If both are set, either is OK, but an lvalue is preferable.
3603 The return value is either GS_ERROR or GS_ALL_DONE, since this function
3604 iterates until solution. */
3606 enum gimplify_status
3607 gimplify_expr (tree *expr_p, tree *pre_p, tree *post_p,
3608 bool (* gimple_test_f) (tree), fallback_t fallback)
3610 tree tmp;
3611 tree internal_pre = NULL_TREE;
3612 tree internal_post = NULL_TREE;
3613 tree save_expr;
3614 int is_statement = (pre_p == NULL);
3615 location_t saved_location;
3616 enum gimplify_status ret;
3618 save_expr = *expr_p;
3619 if (save_expr == NULL_TREE)
3620 return GS_ALL_DONE;
3622 /* We used to check the predicate here and return immediately if it
3623 succeeds. This is wrong; the design is for gimplification to be
3624 idempotent, and for the predicates to only test for valid forms, not
3625 whether they are fully simplified. */
3627 /* Set up our internal queues if needed. */
3628 if (pre_p == NULL)
3629 pre_p = &internal_pre;
3630 if (post_p == NULL)
3631 post_p = &internal_post;
3633 saved_location = input_location;
3634 if (save_expr != error_mark_node
3635 && EXPR_HAS_LOCATION (*expr_p))
3636 input_location = EXPR_LOCATION (*expr_p);
3638 /* Loop over the specific gimplifiers until the toplevel node
3639 remains the same. */
3642 /* Strip away as many useless type conversions as possible
3643 at the toplevel. */
3644 STRIP_USELESS_TYPE_CONVERSION (*expr_p);
3646 /* Remember the expr. */
3647 save_expr = *expr_p;
3649 /* Die, die, die, my darling. */
3650 if (save_expr == error_mark_node
3651 || (TREE_TYPE (save_expr)
3652 && TREE_TYPE (save_expr) == error_mark_node))
3654 ret = GS_ERROR;
3655 break;
3658 /* Do any language-specific gimplification. */
3659 ret = lang_hooks.gimplify_expr (expr_p, pre_p, post_p);
3660 if (ret == GS_OK)
3662 if (*expr_p == NULL_TREE)
3663 break;
3664 if (*expr_p != save_expr)
3665 continue;
3667 else if (ret != GS_UNHANDLED)
3668 break;
3670 ret = GS_OK;
3671 switch (TREE_CODE (*expr_p))
3673 /* First deal with the special cases. */
3675 case POSTINCREMENT_EXPR:
3676 case POSTDECREMENT_EXPR:
3677 case PREINCREMENT_EXPR:
3678 case PREDECREMENT_EXPR:
3679 ret = gimplify_self_mod_expr (expr_p, pre_p, post_p,
3680 fallback != fb_none);
3681 break;
3683 case ARRAY_REF:
3684 case ARRAY_RANGE_REF:
3685 case REALPART_EXPR:
3686 case IMAGPART_EXPR:
3687 case COMPONENT_REF:
3688 case VIEW_CONVERT_EXPR:
3689 ret = gimplify_compound_lval (expr_p, pre_p, post_p,
3690 fallback ? fallback : fb_rvalue);
3691 break;
3693 case COND_EXPR:
3694 ret = gimplify_cond_expr (expr_p, pre_p, post_p, NULL_TREE);
3695 break;
3697 case CALL_EXPR:
3698 ret = gimplify_call_expr (expr_p, pre_p, fallback != fb_none);
3699 break;
3701 case TREE_LIST:
3702 gcc_unreachable ();
3704 case COMPOUND_EXPR:
3705 ret = gimplify_compound_expr (expr_p, pre_p, fallback != fb_none);
3706 break;
3708 case MODIFY_EXPR:
3709 case INIT_EXPR:
3710 ret = gimplify_modify_expr (expr_p, pre_p, post_p,
3711 fallback != fb_none);
3712 break;
3714 case TRUTH_ANDIF_EXPR:
3715 case TRUTH_ORIF_EXPR:
3716 ret = gimplify_boolean_expr (expr_p);
3717 break;
3719 case TRUTH_NOT_EXPR:
3720 TREE_OPERAND (*expr_p, 0)
3721 = gimple_boolify (TREE_OPERAND (*expr_p, 0));
3722 ret = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p, post_p,
3723 is_gimple_val, fb_rvalue);
3724 recalculate_side_effects (*expr_p);
3725 break;
3727 case ADDR_EXPR:
3728 ret = gimplify_addr_expr (expr_p, pre_p, post_p);
3729 break;
3731 case VA_ARG_EXPR:
3732 ret = gimplify_va_arg_expr (expr_p, pre_p, post_p);
3733 break;
3735 case CONVERT_EXPR:
3736 case NOP_EXPR:
3737 if (IS_EMPTY_STMT (*expr_p))
3739 ret = GS_ALL_DONE;
3740 break;
3743 if (VOID_TYPE_P (TREE_TYPE (*expr_p))
3744 || fallback == fb_none)
3746 /* Just strip a conversion to void (or in void context) and
3747 try again. */
3748 *expr_p = TREE_OPERAND (*expr_p, 0);
3749 break;
3752 ret = gimplify_conversion (expr_p);
3753 if (ret == GS_ERROR)
3754 break;
3755 if (*expr_p != save_expr)
3756 break;
3757 /* FALLTHRU */
3759 case FIX_TRUNC_EXPR:
3760 case FIX_CEIL_EXPR:
3761 case FIX_FLOOR_EXPR:
3762 case FIX_ROUND_EXPR:
3763 /* unary_expr: ... | '(' cast ')' val | ... */
3764 ret = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p, post_p,
3765 is_gimple_val, fb_rvalue);
3766 recalculate_side_effects (*expr_p);
3767 break;
3769 case ALIGN_INDIRECT_REF:
3770 case MISALIGNED_INDIRECT_REF:
3771 case INDIRECT_REF:
3772 ret = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p, post_p,
3773 is_gimple_reg, fb_rvalue);
3774 recalculate_side_effects (*expr_p);
3775 break;
3777 /* Constants need not be gimplified. */
3778 case INTEGER_CST:
3779 case REAL_CST:
3780 case STRING_CST:
3781 case COMPLEX_CST:
3782 case VECTOR_CST:
3783 ret = GS_ALL_DONE;
3784 break;
3786 case CONST_DECL:
3787 /* If we require an lvalue, such as for ADDR_EXPR, retain the
3788 CONST_DECL node. Otherwise the decl is replaceable by its
3789 value. */
3790 /* ??? Should be == fb_lvalue, but ADDR_EXPR passes fb_either. */
3791 if (fallback & fb_lvalue)
3792 ret = GS_ALL_DONE;
3793 else
3794 *expr_p = DECL_INITIAL (*expr_p);
3795 break;
3797 case DECL_EXPR:
3798 ret = gimplify_decl_expr (expr_p);
3799 break;
3801 case EXC_PTR_EXPR:
3802 /* FIXME make this a decl. */
3803 ret = GS_ALL_DONE;
3804 break;
3806 case BIND_EXPR:
3807 ret = gimplify_bind_expr (expr_p, NULL, pre_p);
3808 break;
3810 case LOOP_EXPR:
3811 ret = gimplify_loop_expr (expr_p, pre_p);
3812 break;
3814 case SWITCH_EXPR:
3815 ret = gimplify_switch_expr (expr_p, pre_p);
3816 break;
3818 case EXIT_EXPR:
3819 ret = gimplify_exit_expr (expr_p);
3820 break;
3822 case GOTO_EXPR:
3823 /* If the target is not LABEL, then it is a computed jump
3824 and the target needs to be gimplified. */
3825 if (TREE_CODE (GOTO_DESTINATION (*expr_p)) != LABEL_DECL)
3826 ret = gimplify_expr (&GOTO_DESTINATION (*expr_p), pre_p,
3827 NULL, is_gimple_val, fb_rvalue);
3828 break;
3830 case LABEL_EXPR:
3831 ret = GS_ALL_DONE;
3832 gcc_assert (decl_function_context (LABEL_EXPR_LABEL (*expr_p))
3833 == current_function_decl);
3834 break;
3836 case CASE_LABEL_EXPR:
3837 ret = gimplify_case_label_expr (expr_p);
3838 break;
3840 case RETURN_EXPR:
3841 ret = gimplify_return_expr (*expr_p, pre_p);
3842 break;
3844 case CONSTRUCTOR:
3845 /* Don't reduce this in place; let gimplify_init_constructor work its
3846 magic. Buf if we're just elaborating this for side effects, just
3847 gimplify any element that has side-effects. */
3848 if (fallback == fb_none)
3850 for (tmp = CONSTRUCTOR_ELTS (*expr_p); tmp;
3851 tmp = TREE_CHAIN (tmp))
3852 if (TREE_SIDE_EFFECTS (TREE_VALUE (tmp)))
3853 gimplify_expr (&TREE_VALUE (tmp), pre_p, post_p,
3854 gimple_test_f, fallback);
3856 *expr_p = NULL_TREE;
3859 ret = GS_ALL_DONE;
3860 break;
3862 /* The following are special cases that are not handled by the
3863 original GIMPLE grammar. */
3865 /* SAVE_EXPR nodes are converted into a GIMPLE identifier and
3866 eliminated. */
3867 case SAVE_EXPR:
3868 ret = gimplify_save_expr (expr_p, pre_p, post_p);
3869 break;
3871 case BIT_FIELD_REF:
3873 enum gimplify_status r0, r1, r2;
3875 r0 = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p, post_p,
3876 is_gimple_lvalue, fb_either);
3877 r1 = gimplify_expr (&TREE_OPERAND (*expr_p, 1), pre_p, post_p,
3878 is_gimple_val, fb_rvalue);
3879 r2 = gimplify_expr (&TREE_OPERAND (*expr_p, 2), pre_p, post_p,
3880 is_gimple_val, fb_rvalue);
3881 recalculate_side_effects (*expr_p);
3883 ret = MIN (r0, MIN (r1, r2));
3885 break;
3887 case NON_LVALUE_EXPR:
3888 /* This should have been stripped above. */
3889 gcc_unreachable ();
3891 case ASM_EXPR:
3892 ret = gimplify_asm_expr (expr_p, pre_p, post_p);
3893 break;
3895 case TRY_FINALLY_EXPR:
3896 case TRY_CATCH_EXPR:
3897 gimplify_to_stmt_list (&TREE_OPERAND (*expr_p, 0));
3898 gimplify_to_stmt_list (&TREE_OPERAND (*expr_p, 1));
3899 ret = GS_ALL_DONE;
3900 break;
3902 case CLEANUP_POINT_EXPR:
3903 ret = gimplify_cleanup_point_expr (expr_p, pre_p);
3904 break;
3906 case TARGET_EXPR:
3907 ret = gimplify_target_expr (expr_p, pre_p, post_p);
3908 break;
3910 case CATCH_EXPR:
3911 gimplify_to_stmt_list (&CATCH_BODY (*expr_p));
3912 ret = GS_ALL_DONE;
3913 break;
3915 case EH_FILTER_EXPR:
3916 gimplify_to_stmt_list (&EH_FILTER_FAILURE (*expr_p));
3917 ret = GS_ALL_DONE;
3918 break;
3920 case OBJ_TYPE_REF:
3922 enum gimplify_status r0, r1;
3923 r0 = gimplify_expr (&OBJ_TYPE_REF_OBJECT (*expr_p), pre_p, post_p,
3924 is_gimple_val, fb_rvalue);
3925 r1 = gimplify_expr (&OBJ_TYPE_REF_EXPR (*expr_p), pre_p, post_p,
3926 is_gimple_val, fb_rvalue);
3927 ret = MIN (r0, r1);
3929 break;
3931 case LABEL_DECL:
3932 /* We get here when taking the address of a label. We mark
3933 the label as "forced"; meaning it can never be removed and
3934 it is a potential target for any computed goto. */
3935 FORCED_LABEL (*expr_p) = 1;
3936 ret = GS_ALL_DONE;
3937 break;
3939 case STATEMENT_LIST:
3940 ret = gimplify_statement_list (expr_p);
3941 break;
3943 case WITH_SIZE_EXPR:
3945 enum gimplify_status r0, r1;
3946 r0 = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p,
3947 post_p == &internal_post ? NULL : post_p,
3948 gimple_test_f, fallback);
3949 r1 = gimplify_expr (&TREE_OPERAND (*expr_p, 1), pre_p, post_p,
3950 is_gimple_val, fb_rvalue);
3952 break;
3954 case VAR_DECL:
3955 /* ??? If this is a local variable, and it has not been seen in any
3956 outer BIND_EXPR, then it's probably the result of a duplicate
3957 declaration, for which we've already issued an error. It would
3958 be really nice if the front end wouldn't leak these at all.
3959 Currently the only known culprit is C++ destructors, as seen
3960 in g++.old-deja/g++.jason/binding.C. */
3961 tmp = *expr_p;
3962 if (!TREE_STATIC (tmp) && !DECL_EXTERNAL (tmp)
3963 && decl_function_context (tmp) == current_function_decl
3964 && !DECL_SEEN_IN_BIND_EXPR_P (tmp))
3966 gcc_assert (errorcount || sorrycount);
3967 ret = GS_ERROR;
3968 break;
3970 /* FALLTHRU */
3972 case PARM_DECL:
3973 tmp = *expr_p;
3975 /* If this is a local variable sized decl, it must be accessed
3976 indirectly. Perform that substitution. */
3977 if (DECL_VALUE_EXPR (tmp))
3979 *expr_p = unshare_expr (DECL_VALUE_EXPR (tmp));
3980 ret = GS_OK;
3981 break;
3984 ret = GS_ALL_DONE;
3985 break;
3987 case SSA_NAME:
3988 /* Allow callbacks into the gimplifier during optimization. */
3989 ret = GS_ALL_DONE;
3990 break;
3992 default:
3993 switch (TREE_CODE_CLASS (TREE_CODE (*expr_p)))
3995 case tcc_comparison:
3996 /* If this is a comparison of objects of aggregate type,
3997 handle it specially (by converting to a call to
3998 memcmp). It would be nice to only have to do this
3999 for variable-sized objects, but then we'd have to
4000 allow the same nest of reference nodes we allow for
4001 MODIFY_EXPR and that's too complex. */
4002 if (!AGGREGATE_TYPE_P (TREE_TYPE (TREE_OPERAND (*expr_p, 1))))
4003 goto expr_2;
4004 ret = gimplify_variable_sized_compare (expr_p);
4005 break;
4007 /* If *EXPR_P does not need to be special-cased, handle it
4008 according to its class. */
4009 case tcc_unary:
4010 ret = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p,
4011 post_p, is_gimple_val, fb_rvalue);
4012 break;
4014 case tcc_binary:
4015 expr_2:
4017 enum gimplify_status r0, r1;
4019 r0 = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p,
4020 post_p, is_gimple_val, fb_rvalue);
4021 r1 = gimplify_expr (&TREE_OPERAND (*expr_p, 1), pre_p,
4022 post_p, is_gimple_val, fb_rvalue);
4024 ret = MIN (r0, r1);
4025 break;
4028 case tcc_declaration:
4029 case tcc_constant:
4030 ret = GS_ALL_DONE;
4031 goto dont_recalculate;
4033 default:
4034 gcc_assert (TREE_CODE (*expr_p) == TRUTH_AND_EXPR
4035 || TREE_CODE (*expr_p) == TRUTH_OR_EXPR
4036 || TREE_CODE (*expr_p) == TRUTH_XOR_EXPR);
4037 goto expr_2;
4040 recalculate_side_effects (*expr_p);
4041 dont_recalculate:
4042 break;
4045 /* If we replaced *expr_p, gimplify again. */
4046 if (ret == GS_OK && (*expr_p == NULL || *expr_p == save_expr))
4047 ret = GS_ALL_DONE;
4049 while (ret == GS_OK);
4051 /* If we encountered an error_mark somewhere nested inside, either
4052 stub out the statement or propagate the error back out. */
4053 if (ret == GS_ERROR)
4055 if (is_statement)
4056 *expr_p = NULL;
4057 goto out;
4060 /* This was only valid as a return value from the langhook, which
4061 we handled. Make sure it doesn't escape from any other context. */
4062 gcc_assert (ret != GS_UNHANDLED);
4064 if (fallback == fb_none && *expr_p && !is_gimple_stmt (*expr_p))
4066 /* We aren't looking for a value, and we don't have a valid
4067 statement. If it doesn't have side-effects, throw it away. */
4068 if (!TREE_SIDE_EFFECTS (*expr_p))
4069 *expr_p = NULL;
4070 else if (!TREE_THIS_VOLATILE (*expr_p))
4072 /* This is probably a _REF that contains something nested that
4073 has side effects. Recurse through the operands to find it. */
4074 enum tree_code code = TREE_CODE (*expr_p);
4076 switch (code)
4078 case COMPONENT_REF:
4079 case REALPART_EXPR: case IMAGPART_EXPR:
4080 gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p, post_p,
4081 gimple_test_f, fallback);
4082 break;
4084 case ARRAY_REF: case ARRAY_RANGE_REF:
4085 gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p, post_p,
4086 gimple_test_f, fallback);
4087 gimplify_expr (&TREE_OPERAND (*expr_p, 1), pre_p, post_p,
4088 gimple_test_f, fallback);
4089 break;
4091 default:
4092 /* Anything else with side-effects must be converted to
4093 a valid statement before we get here. */
4094 gcc_unreachable ();
4097 *expr_p = NULL;
4099 else if (COMPLETE_TYPE_P (TREE_TYPE (*expr_p)))
4101 /* Historically, the compiler has treated a bare
4102 reference to a volatile lvalue as forcing a load. */
4103 tree tmp = create_tmp_var (TREE_TYPE (*expr_p), "vol");
4104 *expr_p = build (MODIFY_EXPR, TREE_TYPE (tmp), tmp, *expr_p);
4106 else
4107 /* We can't do anything useful with a volatile reference to
4108 incomplete type, so just throw it away. */
4109 *expr_p = NULL;
4112 /* If we are gimplifying at the statement level, we're done. Tack
4113 everything together and replace the original statement with the
4114 gimplified form. */
4115 if (fallback == fb_none || is_statement)
4117 if (internal_pre || internal_post)
4119 append_to_statement_list (*expr_p, &internal_pre);
4120 append_to_statement_list (internal_post, &internal_pre);
4121 annotate_all_with_locus (&internal_pre, input_location);
4122 *expr_p = internal_pre;
4124 else if (!*expr_p)
4126 else if (TREE_CODE (*expr_p) == STATEMENT_LIST)
4127 annotate_all_with_locus (expr_p, input_location);
4128 else
4129 annotate_one_with_locus (*expr_p, input_location);
4130 goto out;
4133 /* Otherwise we're gimplifying a subexpression, so the resulting value is
4134 interesting. */
4136 /* If it's sufficiently simple already, we're done. Unless we are
4137 handling some post-effects internally; if that's the case, we need to
4138 copy into a temp before adding the post-effects to the tree. */
4139 if (!internal_post && (*gimple_test_f) (*expr_p))
4140 goto out;
4142 /* Otherwise, we need to create a new temporary for the gimplified
4143 expression. */
4145 /* We can't return an lvalue if we have an internal postqueue. The
4146 object the lvalue refers to would (probably) be modified by the
4147 postqueue; we need to copy the value out first, which means an
4148 rvalue. */
4149 if ((fallback & fb_lvalue) && !internal_post
4150 && is_gimple_addressable (*expr_p))
4152 /* An lvalue will do. Take the address of the expression, store it
4153 in a temporary, and replace the expression with an INDIRECT_REF of
4154 that temporary. */
4155 tmp = build_fold_addr_expr (*expr_p);
4156 gimplify_expr (&tmp, pre_p, post_p, is_gimple_reg, fb_rvalue);
4157 *expr_p = build1 (INDIRECT_REF, TREE_TYPE (TREE_TYPE (tmp)), tmp);
4159 else if ((fallback & fb_rvalue) && is_gimple_formal_tmp_rhs (*expr_p))
4161 gcc_assert (!VOID_TYPE_P (TREE_TYPE (*expr_p)));
4163 /* An rvalue will do. Assign the gimplified expression into a new
4164 temporary TMP and replace the original expression with TMP. */
4166 if (internal_post || (fallback & fb_lvalue))
4167 /* The postqueue might change the value of the expression between
4168 the initialization and use of the temporary, so we can't use a
4169 formal temp. FIXME do we care? */
4170 *expr_p = get_initialized_tmp_var (*expr_p, pre_p, post_p);
4171 else
4172 *expr_p = get_formal_tmp_var (*expr_p, pre_p);
4174 if (TREE_CODE (*expr_p) != SSA_NAME)
4175 DECL_GIMPLE_FORMAL_TEMP_P (*expr_p) = 1;
4177 else
4179 #ifdef ENABLE_CHECKING
4180 if (!(fallback & fb_mayfail))
4182 fprintf (stderr, "gimplification failed:\n");
4183 print_generic_expr (stderr, *expr_p, 0);
4184 debug_tree (*expr_p);
4185 internal_error ("gimplification failed");
4187 #endif
4188 gcc_assert (fallback & fb_mayfail);
4189 /* If this is an asm statement, and the user asked for the
4190 impossible, don't abort. Fail and let gimplify_asm_expr
4191 issue an error. */
4192 ret = GS_ERROR;
4193 goto out;
4196 /* Make sure the temporary matches our predicate. */
4197 gcc_assert ((*gimple_test_f) (*expr_p));
4199 if (internal_post)
4201 annotate_all_with_locus (&internal_post, input_location);
4202 append_to_statement_list (internal_post, pre_p);
4205 out:
4206 input_location = saved_location;
4207 return ret;
4210 /* Look through TYPE for variable-sized objects and gimplify each such
4211 size that we find. Add to LIST_P any statements generated. */
4213 void
4214 gimplify_type_sizes (tree type, tree *list_p)
4216 tree field, t;
4218 /* Note that we do not check for TYPE_SIZES_GIMPLIFIED already set because
4219 that's not supposed to happen on types where gimplifcation does anything.
4220 We should assert that it isn't set, but we can indeed be called multiple
4221 times on pointers. Unfortunately, this includes fat pointers which we
4222 can't easily test for. We could pass TYPE down to gimplify_one_sizepos
4223 and test there, but it doesn't seem worth it. */
4225 /* We first do the main variant, then copy into any other variants. */
4226 type = TYPE_MAIN_VARIANT (type);
4228 switch (TREE_CODE (type))
4230 case ERROR_MARK:
4231 return;
4233 case INTEGER_TYPE:
4234 case ENUMERAL_TYPE:
4235 case BOOLEAN_TYPE:
4236 case CHAR_TYPE:
4237 case REAL_TYPE:
4238 gimplify_one_sizepos (&TYPE_MIN_VALUE (type), list_p);
4239 gimplify_one_sizepos (&TYPE_MAX_VALUE (type), list_p);
4241 for (t = TYPE_NEXT_VARIANT (type); t; t = TYPE_NEXT_VARIANT (t))
4243 TYPE_MIN_VALUE (t) = TYPE_MIN_VALUE (type);
4244 TYPE_MAX_VALUE (t) = TYPE_MAX_VALUE (type);
4245 TYPE_SIZES_GIMPLIFIED (t) = 1;
4247 break;
4249 case ARRAY_TYPE:
4250 /* These types may not have declarations, so handle them here. */
4251 if (!TYPE_SIZES_GIMPLIFIED (TREE_TYPE (type)))
4252 gimplify_type_sizes (TREE_TYPE (type), list_p);
4254 if (!TYPE_SIZES_GIMPLIFIED (TYPE_DOMAIN (type)))
4255 gimplify_type_sizes (TYPE_DOMAIN (type), list_p);
4256 break;
4258 case RECORD_TYPE:
4259 case UNION_TYPE:
4260 case QUAL_UNION_TYPE:
4261 for (field = TYPE_FIELDS (type); field; field = TREE_CHAIN (field))
4262 if (TREE_CODE (field) == FIELD_DECL)
4263 gimplify_one_sizepos (&DECL_FIELD_OFFSET (field), list_p);
4264 break;
4266 default:
4267 break;
4270 gimplify_one_sizepos (&TYPE_SIZE (type), list_p);
4271 gimplify_one_sizepos (&TYPE_SIZE_UNIT (type), list_p);
4273 for (t = TYPE_NEXT_VARIANT (type); t; t = TYPE_NEXT_VARIANT (t))
4275 TYPE_SIZE (t) = TYPE_SIZE (type);
4276 TYPE_SIZE_UNIT (t) = TYPE_SIZE_UNIT (type);
4277 TYPE_SIZES_GIMPLIFIED (t) = 1;
4280 TYPE_SIZES_GIMPLIFIED (type) = 1;
4283 /* A subroutine of gimplify_type_sizes to make sure that *EXPR_P,
4284 a size or position, has had all of its SAVE_EXPRs evaluated.
4285 We add any required statements to STMT_P. */
4287 void
4288 gimplify_one_sizepos (tree *expr_p, tree *stmt_p)
4290 /* We don't do anything if the value isn't there, is constant, or contains
4291 A PLACEHOLDER_EXPR. We also don't want to do anything if it's already
4292 a VAR_DECL. If it's a VAR_DECL from another function, the gimplfier
4293 will want to replace it with a new variable, but that will cause problems
4294 if this type is from outside the function. It's OK to have that here. */
4295 if (*expr_p == NULL_TREE || TREE_CONSTANT (*expr_p)
4296 || TREE_CODE (*expr_p) == VAR_DECL
4297 || CONTAINS_PLACEHOLDER_P (*expr_p))
4298 return;
4300 *expr_p = unshare_expr (*expr_p);
4301 gimplify_expr (expr_p, stmt_p, NULL, is_gimple_val, fb_rvalue);
4304 #ifdef ENABLE_CHECKING
4305 /* Compare types A and B for a "close enough" match. */
4307 static bool
4308 cpt_same_type (tree a, tree b)
4310 if (lang_hooks.types_compatible_p (a, b))
4311 return true;
4313 /* ??? The C++ FE decomposes METHOD_TYPES to FUNCTION_TYPES and doesn't
4314 link them together. This routine is intended to catch type errors
4315 that will affect the optimizers, and the optimizers don't add new
4316 dereferences of function pointers, so ignore it. */
4317 if ((TREE_CODE (a) == FUNCTION_TYPE || TREE_CODE (a) == METHOD_TYPE)
4318 && (TREE_CODE (b) == FUNCTION_TYPE || TREE_CODE (b) == METHOD_TYPE))
4319 return true;
4321 /* ??? The C FE pushes type qualifiers after the fact into the type of
4322 the element from the type of the array. See build_unary_op's handling
4323 of ADDR_EXPR. This seems wrong -- if we were going to do this, we
4324 should have done it when creating the variable in the first place.
4325 Alternately, why aren't the two array types made variants? */
4326 if (TREE_CODE (a) == ARRAY_TYPE && TREE_CODE (b) == ARRAY_TYPE)
4327 return cpt_same_type (TREE_TYPE (a), TREE_TYPE (b));
4329 /* And because of those, we have to recurse down through pointers. */
4330 if (POINTER_TYPE_P (a) && POINTER_TYPE_P (b))
4331 return cpt_same_type (TREE_TYPE (a), TREE_TYPE (b));
4333 return false;
4336 /* Check for some cases of the front end missing cast expressions.
4337 The type of a dereference should correspond to the pointer type;
4338 similarly the type of an address should match its object. */
4340 static tree
4341 check_pointer_types_r (tree *tp, int *walk_subtrees ATTRIBUTE_UNUSED,
4342 void *data ATTRIBUTE_UNUSED)
4344 tree t = *tp;
4345 tree ptype, otype, dtype;
4347 switch (TREE_CODE (t))
4349 case INDIRECT_REF:
4350 case ARRAY_REF:
4351 otype = TREE_TYPE (t);
4352 ptype = TREE_TYPE (TREE_OPERAND (t, 0));
4353 dtype = TREE_TYPE (ptype);
4354 gcc_assert (cpt_same_type (otype, dtype));
4355 break;
4357 case ADDR_EXPR:
4358 ptype = TREE_TYPE (t);
4359 otype = TREE_TYPE (TREE_OPERAND (t, 0));
4360 dtype = TREE_TYPE (ptype);
4361 if (!cpt_same_type (otype, dtype))
4363 /* &array is allowed to produce a pointer to the element, rather than
4364 a pointer to the array type. We must allow this in order to
4365 properly represent assigning the address of an array in C into
4366 pointer to the element type. */
4367 gcc_assert (TREE_CODE (otype) == ARRAY_TYPE
4368 && POINTER_TYPE_P (ptype)
4369 && cpt_same_type (TREE_TYPE (otype), dtype));
4370 break;
4372 break;
4374 default:
4375 return NULL_TREE;
4379 return NULL_TREE;
4381 #endif
4383 /* Gimplify the body of statements pointed by BODY_P. FNDECL is the
4384 function decl containing BODY. */
4386 void
4387 gimplify_body (tree *body_p, tree fndecl, bool do_parms)
4389 location_t saved_location = input_location;
4390 tree body, parm_stmts;
4392 timevar_push (TV_TREE_GIMPLIFY);
4393 push_gimplify_context ();
4395 /* Unshare most shared trees in the body and in that of any nested functions.
4396 It would seem we don't have to do this for nested functions because
4397 they are supposed to be output and then the outer function gimplified
4398 first, but the g++ front end doesn't always do it that way. */
4399 unshare_body (body_p, fndecl);
4400 unvisit_body (body_p, fndecl);
4402 /* Make sure input_location isn't set to something wierd. */
4403 input_location = DECL_SOURCE_LOCATION (fndecl);
4405 /* Resolve callee-copies. This has to be done before processing
4406 the body so that DECL_VALUE_EXPR gets processed correctly. */
4407 parm_stmts = do_parms ? gimplify_parameters () : NULL;
4409 /* Gimplify the function's body. */
4410 gimplify_stmt (body_p);
4411 body = *body_p;
4413 if (!body)
4414 body = alloc_stmt_list ();
4415 else if (TREE_CODE (body) == STATEMENT_LIST)
4417 tree t = expr_only (*body_p);
4418 if (t)
4419 body = t;
4422 /* If there isn't an outer BIND_EXPR, add one. */
4423 if (TREE_CODE (body) != BIND_EXPR)
4425 tree b = build (BIND_EXPR, void_type_node, NULL_TREE,
4426 NULL_TREE, NULL_TREE);
4427 TREE_SIDE_EFFECTS (b) = 1;
4428 append_to_statement_list_force (body, &BIND_EXPR_BODY (b));
4429 body = b;
4432 /* If we had callee-copies statements, insert them at the beginning
4433 of the function. */
4434 if (parm_stmts)
4436 append_to_statement_list_force (BIND_EXPR_BODY (body), &parm_stmts);
4437 BIND_EXPR_BODY (body) = parm_stmts;
4440 /* Unshare again, in case gimplification was sloppy. */
4441 unshare_all_trees (body);
4443 *body_p = body;
4445 pop_gimplify_context (body);
4447 #ifdef ENABLE_CHECKING
4448 walk_tree (body_p, check_pointer_types_r, NULL, NULL);
4449 #endif
4451 timevar_pop (TV_TREE_GIMPLIFY);
4452 input_location = saved_location;
4455 /* Entry point to the gimplification pass. FNDECL is the FUNCTION_DECL
4456 node for the function we want to gimplify. */
4458 void
4459 gimplify_function_tree (tree fndecl)
4461 tree oldfn;
4463 oldfn = current_function_decl;
4464 current_function_decl = fndecl;
4465 cfun = DECL_STRUCT_FUNCTION (fndecl);
4466 if (cfun == NULL)
4467 allocate_struct_function (fndecl);
4469 gimplify_body (&DECL_SAVED_TREE (fndecl), fndecl, true);
4471 /* If we're instrumenting function entry/exit, then prepend the call to
4472 the entry hook and wrap the whole function in a TRY_FINALLY_EXPR to
4473 catch the exit hook. */
4474 /* ??? Add some way to ignore exceptions for this TFE. */
4475 if (flag_instrument_function_entry_exit
4476 && ! DECL_NO_INSTRUMENT_FUNCTION_ENTRY_EXIT (fndecl))
4478 tree tf, x, bind;
4480 tf = build (TRY_FINALLY_EXPR, void_type_node, NULL, NULL);
4481 TREE_SIDE_EFFECTS (tf) = 1;
4482 x = DECL_SAVED_TREE (fndecl);
4483 append_to_statement_list (x, &TREE_OPERAND (tf, 0));
4484 x = implicit_built_in_decls[BUILT_IN_PROFILE_FUNC_EXIT];
4485 x = build_function_call_expr (x, NULL);
4486 append_to_statement_list (x, &TREE_OPERAND (tf, 1));
4488 bind = build (BIND_EXPR, void_type_node, NULL, NULL, NULL);
4489 TREE_SIDE_EFFECTS (bind) = 1;
4490 x = implicit_built_in_decls[BUILT_IN_PROFILE_FUNC_ENTER];
4491 x = build_function_call_expr (x, NULL);
4492 append_to_statement_list (x, &BIND_EXPR_BODY (bind));
4493 append_to_statement_list (tf, &BIND_EXPR_BODY (bind));
4495 DECL_SAVED_TREE (fndecl) = bind;
4498 current_function_decl = oldfn;
4499 cfun = oldfn ? DECL_STRUCT_FUNCTION (oldfn) : NULL;
4503 /* Expands EXPR to list of gimple statements STMTS. If SIMPLE is true,
4504 force the result to be either ssa_name or an invariant, otherwise
4505 just force it to be a rhs expression. If VAR is not NULL, make the
4506 base variable of the final destination be VAR if suitable. */
4508 tree
4509 force_gimple_operand (tree expr, tree *stmts, bool simple, tree var)
4511 tree t;
4512 enum gimplify_status ret;
4513 gimple_predicate gimple_test_f;
4515 *stmts = NULL_TREE;
4517 if (is_gimple_val (expr))
4518 return expr;
4520 gimple_test_f = simple ? is_gimple_val : is_gimple_reg_rhs;
4522 push_gimplify_context ();
4523 gimplify_ctxp->into_ssa = true;
4525 if (var)
4526 expr = build (MODIFY_EXPR, TREE_TYPE (var), var, expr);
4528 ret = gimplify_expr (&expr, stmts, NULL,
4529 gimple_test_f, fb_rvalue);
4530 gcc_assert (ret != GS_ERROR);
4532 for (t = gimplify_ctxp->temps; t ; t = TREE_CHAIN (t))
4533 add_referenced_tmp_var (t);
4535 pop_gimplify_context (NULL);
4537 return expr;
4540 #include "gt-gimplify.h"