2005-04-29 Jim Tison <jtison@us.ibm.com>
[official-gcc.git] / gcc / gimplify.c
blob1162910e666ce3f19e6ec3a77a6d2a225c45e899
1 /* Tree lowering pass. This pass converts the GENERIC functions-as-trees
2 tree representation into the GIMPLE form.
3 Copyright (C) 2002, 2003, 2004, 2005 Free Software Foundation, Inc.
4 Major work done by Sebastian Pop <s.pop@laposte.net>,
5 Diego Novillo <dnovillo@redhat.com> and Jason Merrill <jason@redhat.com>.
7 This file is part of GCC.
9 GCC is free software; you can redistribute it and/or modify it under
10 the terms of the GNU General Public License as published by the Free
11 Software Foundation; either version 2, or (at your option) any later
12 version.
14 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
15 WARRANTY; without even the implied warranty of MERCHANTABILITY or
16 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
17 for more details.
19 You should have received a copy of the GNU General Public License
20 along with GCC; see the file COPYING. If not, write to the Free
21 Software Foundation, 59 Temple Place - Suite 330, Boston, MA
22 02111-1307, USA. */
24 #include "config.h"
25 #include "system.h"
26 #include "coretypes.h"
27 #include "tm.h"
28 #include "tree.h"
29 #include "rtl.h"
30 #include "errors.h"
31 #include "varray.h"
32 #include "tree-gimple.h"
33 #include "tree-inline.h"
34 #include "diagnostic.h"
35 #include "langhooks.h"
36 #include "langhooks-def.h"
37 #include "tree-flow.h"
38 #include "cgraph.h"
39 #include "timevar.h"
40 #include "except.h"
41 #include "hashtab.h"
42 #include "flags.h"
43 #include "real.h"
44 #include "function.h"
45 #include "output.h"
46 #include "expr.h"
47 #include "ggc.h"
48 #include "target.h"
50 static struct gimplify_ctx
52 tree current_bind_expr;
53 tree temps;
54 tree conditional_cleanups;
55 tree exit_label;
56 tree return_temp;
57 varray_type case_labels;
58 /* The formal temporary table. Should this be persistent? */
59 htab_t temp_htab;
60 int conditions;
61 bool save_stack;
62 bool into_ssa;
63 } *gimplify_ctxp;
66 /* Formal (expression) temporary table handling: Multiple occurrences of
67 the same scalar expression are evaluated into the same temporary. */
69 typedef struct gimple_temp_hash_elt
71 tree val; /* Key */
72 tree temp; /* Value */
73 } elt_t;
75 /* Forward declarations. */
76 static enum gimplify_status gimplify_compound_expr (tree *, tree *, bool);
77 #ifdef ENABLE_CHECKING
78 static bool cpt_same_type (tree a, tree b);
79 #endif
82 /* Return a hash value for a formal temporary table entry. */
84 static hashval_t
85 gimple_tree_hash (const void *p)
87 tree t = ((const elt_t *) p)->val;
88 return iterative_hash_expr (t, 0);
91 /* Compare two formal temporary table entries. */
93 static int
94 gimple_tree_eq (const void *p1, const void *p2)
96 tree t1 = ((const elt_t *) p1)->val;
97 tree t2 = ((const elt_t *) p2)->val;
98 enum tree_code code = TREE_CODE (t1);
100 if (TREE_CODE (t2) != code
101 || TREE_TYPE (t1) != TREE_TYPE (t2))
102 return 0;
104 if (!operand_equal_p (t1, t2, 0))
105 return 0;
107 /* Only allow them to compare equal if they also hash equal; otherwise
108 results are nondeterminate, and we fail bootstrap comparison. */
109 gcc_assert (gimple_tree_hash (p1) == gimple_tree_hash (p2));
111 return 1;
114 /* Set up a context for the gimplifier. */
116 void
117 push_gimplify_context (void)
119 gcc_assert (!gimplify_ctxp);
120 gimplify_ctxp
121 = (struct gimplify_ctx *) xcalloc (1, sizeof (struct gimplify_ctx));
122 if (optimize)
123 gimplify_ctxp->temp_htab
124 = htab_create (1000, gimple_tree_hash, gimple_tree_eq, free);
125 else
126 gimplify_ctxp->temp_htab = NULL;
129 /* Tear down a context for the gimplifier. If BODY is non-null, then
130 put the temporaries into the outer BIND_EXPR. Otherwise, put them
131 in the unexpanded_var_list. */
133 void
134 pop_gimplify_context (tree body)
136 tree t;
138 gcc_assert (gimplify_ctxp && !gimplify_ctxp->current_bind_expr);
140 for (t = gimplify_ctxp->temps; t ; t = TREE_CHAIN (t))
141 DECL_GIMPLE_FORMAL_TEMP_P (t) = 0;
143 if (body)
144 declare_tmp_vars (gimplify_ctxp->temps, body);
145 else
146 record_vars (gimplify_ctxp->temps);
148 #if 0
149 if (!quiet_flag && optimize)
150 fprintf (stderr, " collisions: %f ",
151 htab_collisions (gimplify_ctxp->temp_htab));
152 #endif
154 if (optimize)
155 htab_delete (gimplify_ctxp->temp_htab);
156 free (gimplify_ctxp);
157 gimplify_ctxp = NULL;
160 static void
161 gimple_push_bind_expr (tree bind)
163 TREE_CHAIN (bind) = gimplify_ctxp->current_bind_expr;
164 gimplify_ctxp->current_bind_expr = bind;
167 static void
168 gimple_pop_bind_expr (void)
170 gimplify_ctxp->current_bind_expr
171 = TREE_CHAIN (gimplify_ctxp->current_bind_expr);
174 tree
175 gimple_current_bind_expr (void)
177 return gimplify_ctxp->current_bind_expr;
180 /* Returns true iff there is a COND_EXPR between us and the innermost
181 CLEANUP_POINT_EXPR. This info is used by gimple_push_cleanup. */
183 static bool
184 gimple_conditional_context (void)
186 return gimplify_ctxp->conditions > 0;
189 /* Note that we've entered a COND_EXPR. */
191 static void
192 gimple_push_condition (void)
194 #ifdef ENABLE_CHECKING
195 if (gimplify_ctxp->conditions == 0)
196 gcc_assert (!gimplify_ctxp->conditional_cleanups);
197 #endif
198 ++(gimplify_ctxp->conditions);
201 /* Note that we've left a COND_EXPR. If we're back at unconditional scope
202 now, add any conditional cleanups we've seen to the prequeue. */
204 static void
205 gimple_pop_condition (tree *pre_p)
207 int conds = --(gimplify_ctxp->conditions);
209 gcc_assert (conds >= 0);
210 if (conds == 0)
212 append_to_statement_list (gimplify_ctxp->conditional_cleanups, pre_p);
213 gimplify_ctxp->conditional_cleanups = NULL_TREE;
217 /* A subroutine of append_to_statement_list{,_force}. T is not NULL. */
219 static void
220 append_to_statement_list_1 (tree t, tree *list_p)
222 tree list = *list_p;
223 tree_stmt_iterator i;
225 if (!list)
227 if (t && TREE_CODE (t) == STATEMENT_LIST)
229 *list_p = t;
230 return;
232 *list_p = list = alloc_stmt_list ();
235 i = tsi_last (list);
236 tsi_link_after (&i, t, TSI_CONTINUE_LINKING);
239 /* Add T to the end of the list container pointed by LIST_P.
240 If T is an expression with no effects, it is ignored. */
242 void
243 append_to_statement_list (tree t, tree *list_p)
245 if (t && TREE_SIDE_EFFECTS (t))
246 append_to_statement_list_1 (t, list_p);
249 /* Similar, but the statement is always added, regardless of side effects. */
251 void
252 append_to_statement_list_force (tree t, tree *list_p)
254 if (t != NULL_TREE)
255 append_to_statement_list_1 (t, list_p);
258 /* Both gimplify the statement T and append it to LIST_P. */
260 void
261 gimplify_and_add (tree t, tree *list_p)
263 gimplify_stmt (&t);
264 append_to_statement_list (t, list_p);
267 /* Strip off a legitimate source ending from the input string NAME of
268 length LEN. Rather than having to know the names used by all of
269 our front ends, we strip off an ending of a period followed by
270 up to five characters. (Java uses ".class".) */
272 static inline void
273 remove_suffix (char *name, int len)
275 int i;
277 for (i = 2; i < 8 && len > i; i++)
279 if (name[len - i] == '.')
281 name[len - i] = '\0';
282 break;
287 /* Create a nameless artificial label and put it in the current function
288 context. Returns the newly created label. */
290 tree
291 create_artificial_label (void)
293 tree lab = build_decl (LABEL_DECL, NULL_TREE, void_type_node);
295 DECL_ARTIFICIAL (lab) = 1;
296 DECL_IGNORED_P (lab) = 1;
297 DECL_CONTEXT (lab) = current_function_decl;
298 return lab;
301 /* Create a new temporary name with PREFIX. Returns an identifier. */
303 static GTY(()) unsigned int tmp_var_id_num;
305 tree
306 create_tmp_var_name (const char *prefix)
308 char *tmp_name;
310 if (prefix)
312 char *preftmp = ASTRDUP (prefix);
314 remove_suffix (preftmp, strlen (preftmp));
315 prefix = preftmp;
318 ASM_FORMAT_PRIVATE_NAME (tmp_name, prefix ? prefix : "T", tmp_var_id_num++);
319 return get_identifier (tmp_name);
323 /* Create a new temporary variable declaration of type TYPE.
324 Does NOT push it into the current binding. */
326 tree
327 create_tmp_var_raw (tree type, const char *prefix)
329 tree tmp_var;
330 tree new_type;
332 /* Make the type of the variable writable. */
333 new_type = build_type_variant (type, 0, 0);
334 TYPE_ATTRIBUTES (new_type) = TYPE_ATTRIBUTES (type);
336 tmp_var = build_decl (VAR_DECL, prefix ? create_tmp_var_name (prefix) : NULL,
337 type);
339 /* The variable was declared by the compiler. */
340 DECL_ARTIFICIAL (tmp_var) = 1;
341 /* And we don't want debug info for it. */
342 DECL_IGNORED_P (tmp_var) = 1;
344 /* Make the variable writable. */
345 TREE_READONLY (tmp_var) = 0;
347 DECL_EXTERNAL (tmp_var) = 0;
348 TREE_STATIC (tmp_var) = 0;
349 TREE_USED (tmp_var) = 1;
351 return tmp_var;
354 /* Create a new temporary variable declaration of type TYPE. DOES push the
355 variable into the current binding. Further, assume that this is called
356 only from gimplification or optimization, at which point the creation of
357 certain types are bugs. */
359 tree
360 create_tmp_var (tree type, const char *prefix)
362 tree tmp_var;
364 /* We don't allow types that are addressable (meaning we can't make copies),
365 incomplete, or of variable size. */
366 gcc_assert (!TREE_ADDRESSABLE (type)
367 && COMPLETE_TYPE_P (type)
368 && TREE_CODE (TYPE_SIZE_UNIT (type)) == INTEGER_CST);
370 tmp_var = create_tmp_var_raw (type, prefix);
371 gimple_add_tmp_var (tmp_var);
372 return tmp_var;
375 /* Given a tree, try to return a useful variable name that we can use
376 to prefix a temporary that is being assigned the value of the tree.
377 I.E. given <temp> = &A, return A. */
379 const char *
380 get_name (tree t)
382 tree stripped_decl;
384 stripped_decl = t;
385 STRIP_NOPS (stripped_decl);
386 if (DECL_P (stripped_decl) && DECL_NAME (stripped_decl))
387 return IDENTIFIER_POINTER (DECL_NAME (stripped_decl));
388 else
390 switch (TREE_CODE (stripped_decl))
392 case ADDR_EXPR:
393 return get_name (TREE_OPERAND (stripped_decl, 0));
394 break;
395 default:
396 return NULL;
401 /* Create a temporary with a name derived from VAL. Subroutine of
402 lookup_tmp_var; nobody else should call this function. */
404 static inline tree
405 create_tmp_from_val (tree val)
407 return create_tmp_var (TREE_TYPE (val), get_name (val));
410 /* Create a temporary to hold the value of VAL. If IS_FORMAL, try to reuse
411 an existing expression temporary. */
413 static tree
414 lookup_tmp_var (tree val, bool is_formal)
416 tree ret;
418 /* If not optimizing, never really reuse a temporary. local-alloc
419 won't allocate any variable that is used in more than one basic
420 block, which means it will go into memory, causing much extra
421 work in reload and final and poorer code generation, outweighing
422 the extra memory allocation here. */
423 if (!optimize || !is_formal || TREE_SIDE_EFFECTS (val))
424 ret = create_tmp_from_val (val);
425 else
427 elt_t elt, *elt_p;
428 void **slot;
430 elt.val = val;
431 slot = htab_find_slot (gimplify_ctxp->temp_htab, (void *)&elt, INSERT);
432 if (*slot == NULL)
434 elt_p = xmalloc (sizeof (*elt_p));
435 elt_p->val = val;
436 elt_p->temp = ret = create_tmp_from_val (val);
437 *slot = (void *) elt_p;
439 else
441 elt_p = (elt_t *) *slot;
442 ret = elt_p->temp;
446 if (is_formal)
447 DECL_GIMPLE_FORMAL_TEMP_P (ret) = 1;
449 return ret;
452 /* Returns a formal temporary variable initialized with VAL. PRE_P is as
453 in gimplify_expr. Only use this function if:
455 1) The value of the unfactored expression represented by VAL will not
456 change between the initialization and use of the temporary, and
457 2) The temporary will not be otherwise modified.
459 For instance, #1 means that this is inappropriate for SAVE_EXPR temps,
460 and #2 means it is inappropriate for && temps.
462 For other cases, use get_initialized_tmp_var instead. */
464 static tree
465 internal_get_tmp_var (tree val, tree *pre_p, tree *post_p, bool is_formal)
467 tree t, mod;
469 gimplify_expr (&val, pre_p, post_p, is_gimple_formal_tmp_rhs, fb_rvalue);
471 t = lookup_tmp_var (val, is_formal);
473 mod = build (MODIFY_EXPR, TREE_TYPE (t), t, val);
475 if (EXPR_HAS_LOCATION (val))
476 SET_EXPR_LOCUS (mod, EXPR_LOCUS (val));
477 else
478 SET_EXPR_LOCATION (mod, input_location);
480 /* gimplify_modify_expr might want to reduce this further. */
481 gimplify_and_add (mod, pre_p);
483 /* If we're gimplifying into ssa, gimplify_modify_expr will have
484 given our temporary an ssa name. Find and return it. */
485 if (gimplify_ctxp->into_ssa)
486 t = TREE_OPERAND (mod, 0);
488 return t;
491 tree
492 get_formal_tmp_var (tree val, tree *pre_p)
494 return internal_get_tmp_var (val, pre_p, NULL, true);
497 /* Returns a temporary variable initialized with VAL. PRE_P and POST_P
498 are as in gimplify_expr. */
500 tree
501 get_initialized_tmp_var (tree val, tree *pre_p, tree *post_p)
503 return internal_get_tmp_var (val, pre_p, post_p, false);
506 /* Declares all the variables in VARS in SCOPE. */
508 void
509 declare_tmp_vars (tree vars, tree scope)
511 tree last = vars;
512 if (last)
514 tree temps;
516 /* C99 mode puts the default 'return 0;' for main outside the outer
517 braces. So drill down until we find an actual scope. */
518 while (TREE_CODE (scope) == COMPOUND_EXPR)
519 scope = TREE_OPERAND (scope, 0);
521 gcc_assert (TREE_CODE (scope) == BIND_EXPR);
523 temps = nreverse (last);
524 TREE_CHAIN (last) = BIND_EXPR_VARS (scope);
525 BIND_EXPR_VARS (scope) = temps;
529 void
530 gimple_add_tmp_var (tree tmp)
532 gcc_assert (!TREE_CHAIN (tmp) && !DECL_SEEN_IN_BIND_EXPR_P (tmp));
534 DECL_CONTEXT (tmp) = current_function_decl;
535 DECL_SEEN_IN_BIND_EXPR_P (tmp) = 1;
537 if (gimplify_ctxp)
539 TREE_CHAIN (tmp) = gimplify_ctxp->temps;
540 gimplify_ctxp->temps = tmp;
542 else if (cfun)
543 record_vars (tmp);
544 else
545 declare_tmp_vars (tmp, DECL_SAVED_TREE (current_function_decl));
548 /* Determines whether to assign a locus to the statement STMT. */
550 static bool
551 should_carry_locus_p (tree stmt)
553 /* Don't emit a line note for a label. We particularly don't want to
554 emit one for the break label, since it doesn't actually correspond
555 to the beginning of the loop/switch. */
556 if (TREE_CODE (stmt) == LABEL_EXPR)
557 return false;
559 /* Do not annotate empty statements, since it confuses gcov. */
560 if (!TREE_SIDE_EFFECTS (stmt))
561 return false;
563 return true;
566 static void
567 annotate_one_with_locus (tree t, location_t locus)
569 if (EXPR_P (t) && ! EXPR_HAS_LOCATION (t) && should_carry_locus_p (t))
570 SET_EXPR_LOCATION (t, locus);
573 void
574 annotate_all_with_locus (tree *stmt_p, location_t locus)
576 tree_stmt_iterator i;
578 if (!*stmt_p)
579 return;
581 for (i = tsi_start (*stmt_p); !tsi_end_p (i); tsi_next (&i))
583 tree t = tsi_stmt (i);
585 /* Assuming we've already been gimplified, we shouldn't
586 see nested chaining constructs anymore. */
587 gcc_assert (TREE_CODE (t) != STATEMENT_LIST
588 && TREE_CODE (t) != COMPOUND_EXPR);
590 annotate_one_with_locus (t, locus);
594 /* Similar to copy_tree_r() but do not copy SAVE_EXPR or TARGET_EXPR nodes.
595 These nodes model computations that should only be done once. If we
596 were to unshare something like SAVE_EXPR(i++), the gimplification
597 process would create wrong code. */
599 static tree
600 mostly_copy_tree_r (tree *tp, int *walk_subtrees, void *data)
602 enum tree_code code = TREE_CODE (*tp);
603 /* Don't unshare types, decls, constants and SAVE_EXPR nodes. */
604 if (TREE_CODE_CLASS (code) == tcc_type
605 || TREE_CODE_CLASS (code) == tcc_declaration
606 || TREE_CODE_CLASS (code) == tcc_constant
607 || code == SAVE_EXPR || code == TARGET_EXPR
608 /* We can't do anything sensible with a BLOCK used as an expression,
609 but we also can't just die when we see it because of non-expression
610 uses. So just avert our eyes and cross our fingers. Silly Java. */
611 || code == BLOCK)
612 *walk_subtrees = 0;
613 else
615 gcc_assert (code != BIND_EXPR);
616 copy_tree_r (tp, walk_subtrees, data);
619 return NULL_TREE;
622 /* Callback for walk_tree to unshare most of the shared trees rooted at
623 *TP. If *TP has been visited already (i.e., TREE_VISITED (*TP) == 1),
624 then *TP is deep copied by calling copy_tree_r.
626 This unshares the same trees as copy_tree_r with the exception of
627 SAVE_EXPR nodes. These nodes model computations that should only be
628 done once. If we were to unshare something like SAVE_EXPR(i++), the
629 gimplification process would create wrong code. */
631 static tree
632 copy_if_shared_r (tree *tp, int *walk_subtrees ATTRIBUTE_UNUSED,
633 void *data ATTRIBUTE_UNUSED)
635 tree t = *tp;
636 enum tree_code code = TREE_CODE (t);
638 /* Skip types, decls, and constants. But we do want to look at their
639 types and the bounds of types. Mark them as visited so we properly
640 unmark their subtrees on the unmark pass. If we've already seen them,
641 don't look down further. */
642 if (TREE_CODE_CLASS (code) == tcc_type
643 || TREE_CODE_CLASS (code) == tcc_declaration
644 || TREE_CODE_CLASS (code) == tcc_constant)
646 if (TREE_VISITED (t))
647 *walk_subtrees = 0;
648 else
649 TREE_VISITED (t) = 1;
652 /* If this node has been visited already, unshare it and don't look
653 any deeper. */
654 else if (TREE_VISITED (t))
656 walk_tree (tp, mostly_copy_tree_r, NULL, NULL);
657 *walk_subtrees = 0;
660 /* Otherwise, mark the tree as visited and keep looking. */
661 else
662 TREE_VISITED (t) = 1;
664 return NULL_TREE;
667 static tree
668 unmark_visited_r (tree *tp, int *walk_subtrees ATTRIBUTE_UNUSED,
669 void *data ATTRIBUTE_UNUSED)
671 if (TREE_VISITED (*tp))
672 TREE_VISITED (*tp) = 0;
673 else
674 *walk_subtrees = 0;
676 return NULL_TREE;
679 /* Unshare all the trees in BODY_P, a pointer into the body of FNDECL, and the
680 bodies of any nested functions if we are unsharing the entire body of
681 FNDECL. */
683 static void
684 unshare_body (tree *body_p, tree fndecl)
686 struct cgraph_node *cgn = cgraph_node (fndecl);
688 walk_tree (body_p, copy_if_shared_r, NULL, NULL);
689 if (body_p == &DECL_SAVED_TREE (fndecl))
690 for (cgn = cgn->nested; cgn; cgn = cgn->next_nested)
691 unshare_body (&DECL_SAVED_TREE (cgn->decl), cgn->decl);
694 /* Likewise, but mark all trees as not visited. */
696 static void
697 unvisit_body (tree *body_p, tree fndecl)
699 struct cgraph_node *cgn = cgraph_node (fndecl);
701 walk_tree (body_p, unmark_visited_r, NULL, NULL);
702 if (body_p == &DECL_SAVED_TREE (fndecl))
703 for (cgn = cgn->nested; cgn; cgn = cgn->next_nested)
704 unvisit_body (&DECL_SAVED_TREE (cgn->decl), cgn->decl);
707 /* Unshare T and all the trees reached from T via TREE_CHAIN. */
709 static void
710 unshare_all_trees (tree t)
712 walk_tree (&t, copy_if_shared_r, NULL, NULL);
713 walk_tree (&t, unmark_visited_r, NULL, NULL);
716 /* Unconditionally make an unshared copy of EXPR. This is used when using
717 stored expressions which span multiple functions, such as BINFO_VTABLE,
718 as the normal unsharing process can't tell that they're shared. */
720 tree
721 unshare_expr (tree expr)
723 walk_tree (&expr, mostly_copy_tree_r, NULL, NULL);
724 return expr;
727 /* A terser interface for building a representation of an exception
728 specification. */
730 tree
731 gimple_build_eh_filter (tree body, tree allowed, tree failure)
733 tree t;
735 /* FIXME should the allowed types go in TREE_TYPE? */
736 t = build (EH_FILTER_EXPR, void_type_node, allowed, NULL_TREE);
737 append_to_statement_list (failure, &EH_FILTER_FAILURE (t));
739 t = build (TRY_CATCH_EXPR, void_type_node, NULL_TREE, t);
740 append_to_statement_list (body, &TREE_OPERAND (t, 0));
742 return t;
746 /* WRAPPER is a code such as BIND_EXPR or CLEANUP_POINT_EXPR which can both
747 contain statements and have a value. Assign its value to a temporary
748 and give it void_type_node. Returns the temporary, or NULL_TREE if
749 WRAPPER was already void. */
751 tree
752 voidify_wrapper_expr (tree wrapper, tree temp)
754 if (!VOID_TYPE_P (TREE_TYPE (wrapper)))
756 tree *p, sub = wrapper;
758 restart:
759 /* Set p to point to the body of the wrapper. */
760 switch (TREE_CODE (sub))
762 case BIND_EXPR:
763 /* For a BIND_EXPR, the body is operand 1. */
764 p = &BIND_EXPR_BODY (sub);
765 break;
767 default:
768 p = &TREE_OPERAND (sub, 0);
769 break;
772 /* Advance to the last statement. Set all container types to void. */
773 if (TREE_CODE (*p) == STATEMENT_LIST)
775 tree_stmt_iterator i = tsi_last (*p);
776 p = tsi_end_p (i) ? NULL : tsi_stmt_ptr (i);
778 else
780 for (; TREE_CODE (*p) == COMPOUND_EXPR; p = &TREE_OPERAND (*p, 1))
782 TREE_SIDE_EFFECTS (*p) = 1;
783 TREE_TYPE (*p) = void_type_node;
787 if (p == NULL || IS_EMPTY_STMT (*p))
789 /* Look through exception handling. */
790 else if (TREE_CODE (*p) == TRY_FINALLY_EXPR
791 || TREE_CODE (*p) == TRY_CATCH_EXPR)
793 sub = *p;
794 goto restart;
796 /* The C++ frontend already did this for us. */
797 else if (TREE_CODE (*p) == INIT_EXPR
798 || TREE_CODE (*p) == TARGET_EXPR)
799 temp = TREE_OPERAND (*p, 0);
800 /* If we're returning a dereference, move the dereference
801 outside the wrapper. */
802 else if (TREE_CODE (*p) == INDIRECT_REF)
804 tree ptr = TREE_OPERAND (*p, 0);
805 temp = create_tmp_var (TREE_TYPE (ptr), "retval");
806 *p = build (MODIFY_EXPR, TREE_TYPE (ptr), temp, ptr);
807 temp = build1 (INDIRECT_REF, TREE_TYPE (TREE_TYPE (temp)), temp);
808 /* If this is a BIND_EXPR for a const inline function, it might not
809 have TREE_SIDE_EFFECTS set. That is no longer accurate. */
810 TREE_SIDE_EFFECTS (wrapper) = 1;
812 else
814 if (!temp)
815 temp = create_tmp_var (TREE_TYPE (wrapper), "retval");
816 *p = build (MODIFY_EXPR, TREE_TYPE (temp), temp, *p);
817 TREE_SIDE_EFFECTS (wrapper) = 1;
820 TREE_TYPE (wrapper) = void_type_node;
821 return temp;
824 return NULL_TREE;
827 /* Prepare calls to builtins to SAVE and RESTORE the stack as well as
828 a temporary through which they communicate. */
830 static void
831 build_stack_save_restore (tree *save, tree *restore)
833 tree save_call, tmp_var;
835 save_call =
836 build_function_call_expr (implicit_built_in_decls[BUILT_IN_STACK_SAVE],
837 NULL_TREE);
838 tmp_var = create_tmp_var (ptr_type_node, "saved_stack");
840 *save = build (MODIFY_EXPR, ptr_type_node, tmp_var, save_call);
841 *restore =
842 build_function_call_expr (implicit_built_in_decls[BUILT_IN_STACK_RESTORE],
843 tree_cons (NULL_TREE, tmp_var, NULL_TREE));
846 /* Gimplify a BIND_EXPR. Just voidify and recurse. */
848 static enum gimplify_status
849 gimplify_bind_expr (tree *expr_p, tree temp, tree *pre_p)
851 tree bind_expr = *expr_p;
852 bool old_save_stack = gimplify_ctxp->save_stack;
853 tree t;
855 temp = voidify_wrapper_expr (bind_expr, temp);
857 /* Mark variables seen in this bind expr. */
858 for (t = BIND_EXPR_VARS (bind_expr); t ; t = TREE_CHAIN (t))
859 DECL_SEEN_IN_BIND_EXPR_P (t) = 1;
861 gimple_push_bind_expr (bind_expr);
862 gimplify_ctxp->save_stack = false;
864 gimplify_to_stmt_list (&BIND_EXPR_BODY (bind_expr));
866 if (gimplify_ctxp->save_stack)
868 tree stack_save, stack_restore;
870 /* Save stack on entry and restore it on exit. Add a try_finally
871 block to achieve this. Note that mudflap depends on the
872 format of the emitted code: see mx_register_decls(). */
873 build_stack_save_restore (&stack_save, &stack_restore);
875 t = build (TRY_FINALLY_EXPR, void_type_node,
876 BIND_EXPR_BODY (bind_expr), NULL_TREE);
877 append_to_statement_list (stack_restore, &TREE_OPERAND (t, 1));
879 BIND_EXPR_BODY (bind_expr) = NULL_TREE;
880 append_to_statement_list (stack_save, &BIND_EXPR_BODY (bind_expr));
881 append_to_statement_list (t, &BIND_EXPR_BODY (bind_expr));
884 gimplify_ctxp->save_stack = old_save_stack;
885 gimple_pop_bind_expr ();
887 if (temp)
889 *expr_p = temp;
890 append_to_statement_list (bind_expr, pre_p);
891 return GS_OK;
893 else
894 return GS_ALL_DONE;
897 /* Gimplify a RETURN_EXPR. If the expression to be returned is not a
898 GIMPLE value, it is assigned to a new temporary and the statement is
899 re-written to return the temporary.
901 PRE_P points to the list where side effects that must happen before
902 STMT should be stored. */
904 static enum gimplify_status
905 gimplify_return_expr (tree stmt, tree *pre_p)
907 tree ret_expr = TREE_OPERAND (stmt, 0);
908 tree result_decl, result;
910 if (!ret_expr || TREE_CODE (ret_expr) == RESULT_DECL
911 || ret_expr == error_mark_node)
912 return GS_ALL_DONE;
914 if (VOID_TYPE_P (TREE_TYPE (TREE_TYPE (current_function_decl))))
915 result_decl = NULL_TREE;
916 else
918 result_decl = TREE_OPERAND (ret_expr, 0);
919 if (TREE_CODE (result_decl) == INDIRECT_REF)
920 /* See through a return by reference. */
921 result_decl = TREE_OPERAND (result_decl, 0);
923 gcc_assert ((TREE_CODE (ret_expr) == MODIFY_EXPR
924 || TREE_CODE (ret_expr) == INIT_EXPR)
925 && TREE_CODE (result_decl) == RESULT_DECL);
928 /* If aggregate_value_p is true, then we can return the bare RESULT_DECL.
929 Recall that aggregate_value_p is FALSE for any aggregate type that is
930 returned in registers. If we're returning values in registers, then
931 we don't want to extend the lifetime of the RESULT_DECL, particularly
932 across another call. In addition, for those aggregates for which
933 hard_function_value generates a PARALLEL, we'll die during normal
934 expansion of structure assignments; there's special code in expand_return
935 to handle this case that does not exist in expand_expr. */
936 if (!result_decl
937 || aggregate_value_p (result_decl, TREE_TYPE (current_function_decl)))
938 result = result_decl;
939 else if (gimplify_ctxp->return_temp)
940 result = gimplify_ctxp->return_temp;
941 else
943 result = create_tmp_var (TREE_TYPE (result_decl), NULL);
945 /* ??? With complex control flow (usually involving abnormal edges),
946 we can wind up warning about an uninitialized value for this. Due
947 to how this variable is constructed and initialized, this is never
948 true. Give up and never warn. */
949 TREE_NO_WARNING (result) = 1;
951 gimplify_ctxp->return_temp = result;
954 /* Smash the lhs of the MODIFY_EXPR to the temporary we plan to use.
955 Then gimplify the whole thing. */
956 if (result != result_decl)
957 TREE_OPERAND (ret_expr, 0) = result;
959 gimplify_and_add (TREE_OPERAND (stmt, 0), pre_p);
961 /* If we didn't use a temporary, then the result is just the result_decl.
962 Otherwise we need a simple copy. This should already be gimple. */
963 if (result == result_decl)
964 ret_expr = result;
965 else
966 ret_expr = build (MODIFY_EXPR, TREE_TYPE (result), result_decl, result);
967 TREE_OPERAND (stmt, 0) = ret_expr;
969 return GS_ALL_DONE;
972 /* Gimplifies a DECL_EXPR node *STMT_P by making any necessary allocation
973 and initialization explicit. */
975 static enum gimplify_status
976 gimplify_decl_expr (tree *stmt_p)
978 tree stmt = *stmt_p;
979 tree decl = DECL_EXPR_DECL (stmt);
981 *stmt_p = NULL_TREE;
983 if (TREE_TYPE (decl) == error_mark_node)
984 return GS_ERROR;
986 else if (TREE_CODE (decl) == TYPE_DECL)
987 gimplify_type_sizes (TREE_TYPE (decl), stmt_p);
989 else if (TREE_CODE (decl) == VAR_DECL && !DECL_EXTERNAL (decl))
991 tree init = DECL_INITIAL (decl);
993 if (!TREE_CONSTANT (DECL_SIZE (decl)))
995 /* This is a variable-sized decl. Simplify its size and mark it
996 for deferred expansion. Note that mudflap depends on the format
997 of the emitted code: see mx_register_decls(). */
998 tree t, args, addr, ptr_type;
1000 /* ??? We really shouldn't need to gimplify the type of the variable
1001 since it already should have been done. But leave this here
1002 for now to avoid disrupting too many things at once. */
1003 if (!TYPE_SIZES_GIMPLIFIED (TREE_TYPE (decl)))
1004 gimplify_type_sizes (TREE_TYPE (decl), stmt_p);
1006 gimplify_one_sizepos (&DECL_SIZE (decl), stmt_p);
1007 gimplify_one_sizepos (&DECL_SIZE_UNIT (decl), stmt_p);
1009 /* All occurrences of this decl in final gimplified code will be
1010 replaced by indirection. Setting DECL_VALUE_EXPR does two
1011 things: First, it lets the rest of the gimplifier know what
1012 replacement to use. Second, it lets the debug info know
1013 where to find the value. */
1014 ptr_type = build_pointer_type (TREE_TYPE (decl));
1015 addr = create_tmp_var (ptr_type, get_name (decl));
1016 DECL_IGNORED_P (addr) = 0;
1017 t = build_fold_indirect_ref (addr);
1018 DECL_VALUE_EXPR (decl) = t;
1020 args = tree_cons (NULL, DECL_SIZE_UNIT (decl), NULL);
1021 t = built_in_decls[BUILT_IN_ALLOCA];
1022 t = build_function_call_expr (t, args);
1023 t = fold_convert (ptr_type, t);
1024 t = build2 (MODIFY_EXPR, void_type_node, addr, t);
1026 gimplify_and_add (t, stmt_p);
1028 /* Indicate that we need to restore the stack level when the
1029 enclosing BIND_EXPR is exited. */
1030 gimplify_ctxp->save_stack = true;
1033 if (init && init != error_mark_node)
1035 if (!TREE_STATIC (decl))
1037 DECL_INITIAL (decl) = NULL_TREE;
1038 init = build (MODIFY_EXPR, void_type_node, decl, init);
1039 gimplify_and_add (init, stmt_p);
1041 else
1042 /* We must still examine initializers for static variables
1043 as they may contain a label address. */
1044 walk_tree (&init, force_labels_r, NULL, NULL);
1047 /* This decl isn't mentioned in the enclosing block, so add it to the
1048 list of temps. FIXME it seems a bit of a kludge to say that
1049 anonymous artificial vars aren't pushed, but everything else is. */
1050 if (DECL_ARTIFICIAL (decl) && DECL_NAME (decl) == NULL_TREE)
1051 gimple_add_tmp_var (decl);
1054 return GS_ALL_DONE;
1057 /* Gimplify a LOOP_EXPR. Normally this just involves gimplifying the body
1058 and replacing the LOOP_EXPR with goto, but if the loop contains an
1059 EXIT_EXPR, we need to append a label for it to jump to. */
1061 static enum gimplify_status
1062 gimplify_loop_expr (tree *expr_p, tree *pre_p)
1064 tree saved_label = gimplify_ctxp->exit_label;
1065 tree start_label = build1 (LABEL_EXPR, void_type_node, NULL_TREE);
1066 tree jump_stmt = build_and_jump (&LABEL_EXPR_LABEL (start_label));
1068 append_to_statement_list (start_label, pre_p);
1070 gimplify_ctxp->exit_label = NULL_TREE;
1072 gimplify_and_add (LOOP_EXPR_BODY (*expr_p), pre_p);
1074 if (gimplify_ctxp->exit_label)
1076 append_to_statement_list (jump_stmt, pre_p);
1077 *expr_p = build1 (LABEL_EXPR, void_type_node, gimplify_ctxp->exit_label);
1079 else
1080 *expr_p = jump_stmt;
1082 gimplify_ctxp->exit_label = saved_label;
1084 return GS_ALL_DONE;
1087 /* Compare two case labels. Because the front end should already have
1088 made sure that case ranges do not overlap, it is enough to only compare
1089 the CASE_LOW values of each case label. */
1091 static int
1092 compare_case_labels (const void *p1, const void *p2)
1094 tree case1 = *(tree *)p1;
1095 tree case2 = *(tree *)p2;
1097 return tree_int_cst_compare (CASE_LOW (case1), CASE_LOW (case2));
1100 /* Sort the case labels in LABEL_VEC in place in ascending order. */
1102 void
1103 sort_case_labels (tree label_vec)
1105 size_t len = TREE_VEC_LENGTH (label_vec);
1106 tree default_case = TREE_VEC_ELT (label_vec, len - 1);
1108 if (CASE_LOW (default_case))
1110 size_t i;
1112 /* The last label in the vector should be the default case
1113 but it is not. */
1114 for (i = 0; i < len; ++i)
1116 tree t = TREE_VEC_ELT (label_vec, i);
1117 if (!CASE_LOW (t))
1119 default_case = t;
1120 TREE_VEC_ELT (label_vec, i) = TREE_VEC_ELT (label_vec, len - 1);
1121 TREE_VEC_ELT (label_vec, len - 1) = default_case;
1122 break;
1127 qsort (&TREE_VEC_ELT (label_vec, 0), len - 1, sizeof (tree),
1128 compare_case_labels);
1131 /* Gimplify a SWITCH_EXPR, and collect a TREE_VEC of the labels it can
1132 branch to. */
1134 static enum gimplify_status
1135 gimplify_switch_expr (tree *expr_p, tree *pre_p)
1137 tree switch_expr = *expr_p;
1138 enum gimplify_status ret;
1140 ret = gimplify_expr (&SWITCH_COND (switch_expr), pre_p, NULL,
1141 is_gimple_val, fb_rvalue);
1143 if (SWITCH_BODY (switch_expr))
1145 varray_type labels, saved_labels;
1146 tree label_vec, default_case = NULL_TREE;
1147 size_t i, len;
1149 /* If someone can be bothered to fill in the labels, they can
1150 be bothered to null out the body too. */
1151 gcc_assert (!SWITCH_LABELS (switch_expr));
1153 saved_labels = gimplify_ctxp->case_labels;
1154 VARRAY_TREE_INIT (gimplify_ctxp->case_labels, 8, "case_labels");
1156 gimplify_to_stmt_list (&SWITCH_BODY (switch_expr));
1158 labels = gimplify_ctxp->case_labels;
1159 gimplify_ctxp->case_labels = saved_labels;
1161 len = VARRAY_ACTIVE_SIZE (labels);
1163 for (i = 0; i < len; ++i)
1165 tree t = VARRAY_TREE (labels, i);
1166 if (!CASE_LOW (t))
1168 /* The default case must be the last label in the list. */
1169 default_case = t;
1170 VARRAY_TREE (labels, i) = VARRAY_TREE (labels, len - 1);
1171 len--;
1172 break;
1176 label_vec = make_tree_vec (len + 1);
1177 SWITCH_LABELS (*expr_p) = label_vec;
1178 append_to_statement_list (switch_expr, pre_p);
1180 if (! default_case)
1182 /* If the switch has no default label, add one, so that we jump
1183 around the switch body. */
1184 default_case = build (CASE_LABEL_EXPR, void_type_node, NULL_TREE,
1185 NULL_TREE, create_artificial_label ());
1186 append_to_statement_list (SWITCH_BODY (switch_expr), pre_p);
1187 *expr_p = build (LABEL_EXPR, void_type_node,
1188 CASE_LABEL (default_case));
1190 else
1191 *expr_p = SWITCH_BODY (switch_expr);
1193 for (i = 0; i < len; ++i)
1194 TREE_VEC_ELT (label_vec, i) = VARRAY_TREE (labels, i);
1195 TREE_VEC_ELT (label_vec, len) = default_case;
1197 sort_case_labels (label_vec);
1199 SWITCH_BODY (switch_expr) = NULL;
1201 else
1202 gcc_assert (SWITCH_LABELS (switch_expr));
1204 return ret;
1207 static enum gimplify_status
1208 gimplify_case_label_expr (tree *expr_p)
1210 tree expr = *expr_p;
1212 gcc_assert (gimplify_ctxp->case_labels);
1213 VARRAY_PUSH_TREE (gimplify_ctxp->case_labels, expr);
1214 *expr_p = build (LABEL_EXPR, void_type_node, CASE_LABEL (expr));
1215 return GS_ALL_DONE;
1218 /* Build a GOTO to the LABEL_DECL pointed to by LABEL_P, building it first
1219 if necessary. */
1221 tree
1222 build_and_jump (tree *label_p)
1224 if (label_p == NULL)
1225 /* If there's nowhere to jump, just fall through. */
1226 return NULL_TREE;
1228 if (*label_p == NULL_TREE)
1230 tree label = create_artificial_label ();
1231 *label_p = label;
1234 return build1 (GOTO_EXPR, void_type_node, *label_p);
1237 /* Gimplify an EXIT_EXPR by converting to a GOTO_EXPR inside a COND_EXPR.
1238 This also involves building a label to jump to and communicating it to
1239 gimplify_loop_expr through gimplify_ctxp->exit_label. */
1241 static enum gimplify_status
1242 gimplify_exit_expr (tree *expr_p)
1244 tree cond = TREE_OPERAND (*expr_p, 0);
1245 tree expr;
1247 expr = build_and_jump (&gimplify_ctxp->exit_label);
1248 expr = build (COND_EXPR, void_type_node, cond, expr, NULL_TREE);
1249 *expr_p = expr;
1251 return GS_OK;
1254 /* A helper function to be called via walk_tree. Mark all labels under *TP
1255 as being forced. To be called for DECL_INITIAL of static variables. */
1257 tree
1258 force_labels_r (tree *tp, int *walk_subtrees, void *data ATTRIBUTE_UNUSED)
1260 if (TYPE_P (*tp))
1261 *walk_subtrees = 0;
1262 if (TREE_CODE (*tp) == LABEL_DECL)
1263 FORCED_LABEL (*tp) = 1;
1265 return NULL_TREE;
1268 /* *EXPR_P is a COMPONENT_REF being used as an rvalue. If its type is
1269 different from its canonical type, wrap the whole thing inside a
1270 NOP_EXPR and force the type of the COMPONENT_REF to be the canonical
1271 type.
1273 The canonical type of a COMPONENT_REF is the type of the field being
1274 referenced--unless the field is a bit-field which can be read directly
1275 in a smaller mode, in which case the canonical type is the
1276 sign-appropriate type corresponding to that mode. */
1278 static void
1279 canonicalize_component_ref (tree *expr_p)
1281 tree expr = *expr_p;
1282 tree type;
1284 gcc_assert (TREE_CODE (expr) == COMPONENT_REF);
1286 if (INTEGRAL_TYPE_P (TREE_TYPE (expr)))
1287 type = TREE_TYPE (get_unwidened (expr, NULL_TREE));
1288 else
1289 type = TREE_TYPE (TREE_OPERAND (expr, 1));
1291 if (TREE_TYPE (expr) != type)
1293 tree old_type = TREE_TYPE (expr);
1295 /* Set the type of the COMPONENT_REF to the underlying type. */
1296 TREE_TYPE (expr) = type;
1298 /* And wrap the whole thing inside a NOP_EXPR. */
1299 expr = build1 (NOP_EXPR, old_type, expr);
1301 *expr_p = expr;
1305 /* If a NOP conversion is changing a pointer to array of foo to a pointer
1306 to foo, embed that change in the ADDR_EXPR by converting
1307 T array[U];
1308 (T *)&array
1310 &array[L]
1311 where L is the lower bound. For simplicity, only do this for constant
1312 lower bound. */
1314 static void
1315 canonicalize_addr_expr (tree *expr_p)
1317 tree expr = *expr_p;
1318 tree ctype = TREE_TYPE (expr);
1319 tree addr_expr = TREE_OPERAND (expr, 0);
1320 tree atype = TREE_TYPE (addr_expr);
1321 tree dctype, datype, ddatype, otype, obj_expr;
1323 /* Both cast and addr_expr types should be pointers. */
1324 if (!POINTER_TYPE_P (ctype) || !POINTER_TYPE_P (atype))
1325 return;
1327 /* The addr_expr type should be a pointer to an array. */
1328 datype = TREE_TYPE (atype);
1329 if (TREE_CODE (datype) != ARRAY_TYPE)
1330 return;
1332 /* Both cast and addr_expr types should address the same object type. */
1333 dctype = TREE_TYPE (ctype);
1334 ddatype = TREE_TYPE (datype);
1335 if (!lang_hooks.types_compatible_p (ddatype, dctype))
1336 return;
1338 /* The addr_expr and the object type should match. */
1339 obj_expr = TREE_OPERAND (addr_expr, 0);
1340 otype = TREE_TYPE (obj_expr);
1341 if (!lang_hooks.types_compatible_p (otype, datype))
1342 return;
1344 /* The lower bound and element sizes must be constant. */
1345 if (!TYPE_SIZE_UNIT (dctype)
1346 || TREE_CODE (TYPE_SIZE_UNIT (dctype)) != INTEGER_CST
1347 || !TYPE_DOMAIN (datype) || !TYPE_MIN_VALUE (TYPE_DOMAIN (datype))
1348 || TREE_CODE (TYPE_MIN_VALUE (TYPE_DOMAIN (datype))) != INTEGER_CST)
1349 return;
1351 /* All checks succeeded. Build a new node to merge the cast. */
1352 *expr_p = build4 (ARRAY_REF, dctype, obj_expr,
1353 TYPE_MIN_VALUE (TYPE_DOMAIN (datype)),
1354 TYPE_MIN_VALUE (TYPE_DOMAIN (datype)),
1355 size_binop (EXACT_DIV_EXPR, TYPE_SIZE_UNIT (dctype),
1356 size_int (TYPE_ALIGN_UNIT (dctype))));
1357 *expr_p = build1 (ADDR_EXPR, ctype, *expr_p);
1360 /* *EXPR_P is a NOP_EXPR or CONVERT_EXPR. Remove it and/or other conversions
1361 underneath as appropriate. */
1363 static enum gimplify_status
1364 gimplify_conversion (tree *expr_p)
1366 gcc_assert (TREE_CODE (*expr_p) == NOP_EXPR
1367 || TREE_CODE (*expr_p) == CONVERT_EXPR);
1369 /* Then strip away all but the outermost conversion. */
1370 STRIP_SIGN_NOPS (TREE_OPERAND (*expr_p, 0));
1372 /* And remove the outermost conversion if it's useless. */
1373 if (tree_ssa_useless_type_conversion (*expr_p))
1374 *expr_p = TREE_OPERAND (*expr_p, 0);
1376 /* If we still have a conversion at the toplevel,
1377 then canonicalize some constructs. */
1378 if (TREE_CODE (*expr_p) == NOP_EXPR || TREE_CODE (*expr_p) == CONVERT_EXPR)
1380 tree sub = TREE_OPERAND (*expr_p, 0);
1382 /* If a NOP conversion is changing the type of a COMPONENT_REF
1383 expression, then canonicalize its type now in order to expose more
1384 redundant conversions. */
1385 if (TREE_CODE (sub) == COMPONENT_REF)
1386 canonicalize_component_ref (&TREE_OPERAND (*expr_p, 0));
1388 /* If a NOP conversion is changing a pointer to array of foo
1389 to a pointer to foo, embed that change in the ADDR_EXPR. */
1390 else if (TREE_CODE (sub) == ADDR_EXPR)
1391 canonicalize_addr_expr (expr_p);
1394 return GS_OK;
1397 /* Gimplify the COMPONENT_REF, ARRAY_REF, REALPART_EXPR or IMAGPART_EXPR
1398 node pointed by EXPR_P.
1400 compound_lval
1401 : min_lval '[' val ']'
1402 | min_lval '.' ID
1403 | compound_lval '[' val ']'
1404 | compound_lval '.' ID
1406 This is not part of the original SIMPLE definition, which separates
1407 array and member references, but it seems reasonable to handle them
1408 together. Also, this way we don't run into problems with union
1409 aliasing; gcc requires that for accesses through a union to alias, the
1410 union reference must be explicit, which was not always the case when we
1411 were splitting up array and member refs.
1413 PRE_P points to the list where side effects that must happen before
1414 *EXPR_P should be stored.
1416 POST_P points to the list where side effects that must happen after
1417 *EXPR_P should be stored. */
1419 static enum gimplify_status
1420 gimplify_compound_lval (tree *expr_p, tree *pre_p,
1421 tree *post_p, fallback_t fallback)
1423 tree *p;
1424 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; ; p = &TREE_OPERAND (*p, 0))
1438 /* Fold INDIRECT_REFs now to turn them into ARRAY_REFs. */
1439 if (TREE_CODE (*p) == INDIRECT_REF)
1440 *p = fold_indirect_ref (*p);
1441 if (!handled_component_p (*p))
1442 break;
1443 VARRAY_PUSH_GENERIC_PTR_NOGC (stack, *p);
1446 gcc_assert (VARRAY_ACTIVE_SIZE (stack));
1448 /* Now STACK is a stack of pointers to all the refs we've walked through
1449 and P points to the innermost expression.
1451 Java requires that we elaborated nodes in source order. That
1452 means we must gimplify the inner expression followed by each of
1453 the indices, in order. But we can't gimplify the inner
1454 expression until we deal with any variable bounds, sizes, or
1455 positions in order to deal with PLACEHOLDER_EXPRs.
1457 So we do this in three steps. First we deal with the annotations
1458 for any variables in the components, then we gimplify the base,
1459 then we gimplify any indices, from left to right. */
1460 for (i = VARRAY_ACTIVE_SIZE (stack) - 1; i >= 0; i--)
1462 tree t = VARRAY_GENERIC_PTR_NOGC (stack, i);
1464 if (TREE_CODE (t) == ARRAY_REF || TREE_CODE (t) == ARRAY_RANGE_REF)
1466 /* Gimplify the low bound and element type size and put them into
1467 the ARRAY_REF. If these values are set, they have already been
1468 gimplified. */
1469 if (!TREE_OPERAND (t, 2))
1471 tree low = unshare_expr (array_ref_low_bound (t));
1472 if (!is_gimple_min_invariant (low))
1474 TREE_OPERAND (t, 2) = low;
1475 tret = gimplify_expr (&TREE_OPERAND (t, 2), pre_p, post_p,
1476 is_gimple_formal_tmp_reg, fb_rvalue);
1477 ret = MIN (ret, tret);
1481 if (!TREE_OPERAND (t, 3))
1483 tree elmt_type = TREE_TYPE (TREE_TYPE (TREE_OPERAND (t, 0)));
1484 tree elmt_size = unshare_expr (array_ref_element_size (t));
1485 tree factor = size_int (TYPE_ALIGN_UNIT (elmt_type));
1487 /* Divide the element size by the alignment of the element
1488 type (above). */
1489 elmt_size = size_binop (EXACT_DIV_EXPR, elmt_size, factor);
1491 if (!is_gimple_min_invariant (elmt_size))
1493 TREE_OPERAND (t, 3) = elmt_size;
1494 tret = gimplify_expr (&TREE_OPERAND (t, 3), pre_p, post_p,
1495 is_gimple_formal_tmp_reg, fb_rvalue);
1496 ret = MIN (ret, tret);
1500 else if (TREE_CODE (t) == COMPONENT_REF)
1502 /* Set the field offset into T and gimplify it. */
1503 if (!TREE_OPERAND (t, 2))
1505 tree offset = unshare_expr (component_ref_field_offset (t));
1506 tree field = TREE_OPERAND (t, 1);
1507 tree factor
1508 = size_int (DECL_OFFSET_ALIGN (field) / BITS_PER_UNIT);
1510 /* Divide the offset by its alignment. */
1511 offset = size_binop (EXACT_DIV_EXPR, offset, factor);
1513 if (!is_gimple_min_invariant (offset))
1515 TREE_OPERAND (t, 2) = offset;
1516 tret = gimplify_expr (&TREE_OPERAND (t, 2), pre_p, post_p,
1517 is_gimple_formal_tmp_reg, fb_rvalue);
1518 ret = MIN (ret, tret);
1524 /* Step 2 is to gimplify the base expression. */
1525 tret = gimplify_expr (p, pre_p, post_p, is_gimple_min_lval, fallback);
1526 ret = MIN (ret, tret);
1528 /* And finally, the indices and operands to BIT_FIELD_REF. During this
1529 loop we also remove any useless conversions. */
1530 for (; VARRAY_ACTIVE_SIZE (stack) > 0; )
1532 tree t = VARRAY_TOP_TREE (stack);
1534 if (TREE_CODE (t) == ARRAY_REF || TREE_CODE (t) == ARRAY_RANGE_REF)
1536 /* Gimplify the dimension.
1537 Temporary fix for gcc.c-torture/execute/20040313-1.c.
1538 Gimplify non-constant array indices into a temporary
1539 variable.
1540 FIXME - The real fix is to gimplify post-modify
1541 expressions into a minimal gimple lvalue. However, that
1542 exposes bugs in alias analysis. The alias analyzer does
1543 not handle &PTR->FIELD very well. Will fix after the
1544 branch is merged into mainline (dnovillo 2004-05-03). */
1545 if (!is_gimple_min_invariant (TREE_OPERAND (t, 1)))
1547 tret = gimplify_expr (&TREE_OPERAND (t, 1), pre_p, post_p,
1548 is_gimple_formal_tmp_reg, fb_rvalue);
1549 ret = MIN (ret, tret);
1552 else if (TREE_CODE (t) == BIT_FIELD_REF)
1554 tret = gimplify_expr (&TREE_OPERAND (t, 1), pre_p, post_p,
1555 is_gimple_val, fb_rvalue);
1556 ret = MIN (ret, tret);
1557 tret = gimplify_expr (&TREE_OPERAND (t, 2), pre_p, post_p,
1558 is_gimple_val, fb_rvalue);
1559 ret = MIN (ret, tret);
1562 STRIP_USELESS_TYPE_CONVERSION (TREE_OPERAND (t, 0));
1564 /* The innermost expression P may have originally had TREE_SIDE_EFFECTS
1565 set which would have caused all the outer expressions in EXPR_P
1566 leading to P to also have had TREE_SIDE_EFFECTS set. */
1567 recalculate_side_effects (t);
1568 VARRAY_POP (stack);
1571 tret = gimplify_expr (p, pre_p, post_p, is_gimple_min_lval, fallback);
1572 ret = MIN (ret, tret);
1574 /* If the outermost expression is a COMPONENT_REF, canonicalize its type. */
1575 if ((fallback & fb_rvalue) && TREE_CODE (*expr_p) == COMPONENT_REF)
1577 canonicalize_component_ref (expr_p);
1578 ret = MIN (ret, GS_OK);
1581 VARRAY_FREE (stack);
1583 return ret;
1586 /* Gimplify the self modifying expression pointed by EXPR_P (++, --, +=, -=).
1588 PRE_P points to the list where side effects that must happen before
1589 *EXPR_P should be stored.
1591 POST_P points to the list where side effects that must happen after
1592 *EXPR_P should be stored.
1594 WANT_VALUE is nonzero iff we want to use the value of this expression
1595 in another expression. */
1597 static enum gimplify_status
1598 gimplify_self_mod_expr (tree *expr_p, tree *pre_p, tree *post_p,
1599 bool want_value)
1601 enum tree_code code;
1602 tree lhs, lvalue, rhs, t1;
1603 bool postfix;
1604 enum tree_code arith_code;
1605 enum gimplify_status ret;
1607 code = TREE_CODE (*expr_p);
1609 gcc_assert (code == POSTINCREMENT_EXPR || code == POSTDECREMENT_EXPR
1610 || code == PREINCREMENT_EXPR || code == PREDECREMENT_EXPR);
1612 /* Prefix or postfix? */
1613 if (code == POSTINCREMENT_EXPR || code == POSTDECREMENT_EXPR)
1614 /* Faster to treat as prefix if result is not used. */
1615 postfix = want_value;
1616 else
1617 postfix = false;
1619 /* Add or subtract? */
1620 if (code == PREINCREMENT_EXPR || code == POSTINCREMENT_EXPR)
1621 arith_code = PLUS_EXPR;
1622 else
1623 arith_code = MINUS_EXPR;
1625 /* Gimplify the LHS into a GIMPLE lvalue. */
1626 lvalue = TREE_OPERAND (*expr_p, 0);
1627 ret = gimplify_expr (&lvalue, pre_p, post_p, is_gimple_lvalue, fb_lvalue);
1628 if (ret == GS_ERROR)
1629 return ret;
1631 /* Extract the operands to the arithmetic operation. */
1632 lhs = lvalue;
1633 rhs = TREE_OPERAND (*expr_p, 1);
1635 /* For postfix operator, we evaluate the LHS to an rvalue and then use
1636 that as the result value and in the postqueue operation. */
1637 if (postfix)
1639 ret = gimplify_expr (&lhs, pre_p, post_p, is_gimple_val, fb_rvalue);
1640 if (ret == GS_ERROR)
1641 return ret;
1644 t1 = build (arith_code, TREE_TYPE (*expr_p), lhs, rhs);
1645 t1 = build (MODIFY_EXPR, TREE_TYPE (lvalue), lvalue, t1);
1647 if (postfix)
1649 gimplify_and_add (t1, post_p);
1650 *expr_p = lhs;
1651 return GS_ALL_DONE;
1653 else
1655 *expr_p = t1;
1656 return GS_OK;
1660 /* If *EXPR_P has a variable sized type, wrap it in a WITH_SIZE_EXPR. */
1662 static void
1663 maybe_with_size_expr (tree *expr_p)
1665 tree expr = *expr_p;
1666 tree type = TREE_TYPE (expr);
1667 tree size;
1669 /* If we've already wrapped this or the type is error_mark_node, we can't do
1670 anything. */
1671 if (TREE_CODE (expr) == WITH_SIZE_EXPR
1672 || type == error_mark_node)
1673 return;
1675 /* If the size isn't known or is a constant, we have nothing to do. */
1676 size = TYPE_SIZE_UNIT (type);
1677 if (!size || TREE_CODE (size) == INTEGER_CST)
1678 return;
1680 /* Otherwise, make a WITH_SIZE_EXPR. */
1681 size = unshare_expr (size);
1682 size = SUBSTITUTE_PLACEHOLDER_IN_EXPR (size, expr);
1683 *expr_p = build2 (WITH_SIZE_EXPR, type, expr, size);
1686 /* Subroutine of gimplify_call_expr: Gimplify a single argument. */
1688 static enum gimplify_status
1689 gimplify_arg (tree *expr_p, tree *pre_p)
1691 bool (*test) (tree);
1692 fallback_t fb;
1694 /* In general, we allow lvalues for function arguments to avoid
1695 extra overhead of copying large aggregates out of even larger
1696 aggregates into temporaries only to copy the temporaries to
1697 the argument list. Make optimizers happy by pulling out to
1698 temporaries those types that fit in registers. */
1699 if (is_gimple_reg_type (TREE_TYPE (*expr_p)))
1700 test = is_gimple_val, fb = fb_rvalue;
1701 else
1702 test = is_gimple_lvalue, fb = fb_either;
1704 /* If this is a variable sized type, we must remember the size. */
1705 maybe_with_size_expr (expr_p);
1707 /* There is a sequence point before a function call. Side effects in
1708 the argument list must occur before the actual call. So, when
1709 gimplifying arguments, force gimplify_expr to use an internal
1710 post queue which is then appended to the end of PRE_P. */
1711 return gimplify_expr (expr_p, pre_p, NULL, test, fb);
1714 /* Gimplify the CALL_EXPR node pointed by EXPR_P. PRE_P points to the
1715 list where side effects that must happen before *EXPR_P should be stored.
1716 WANT_VALUE is true if the result of the call is desired. */
1718 static enum gimplify_status
1719 gimplify_call_expr (tree *expr_p, tree *pre_p, bool want_value)
1721 tree decl;
1722 tree arglist;
1723 enum gimplify_status ret;
1725 gcc_assert (TREE_CODE (*expr_p) == CALL_EXPR);
1727 /* For reliable diagnostics during inlining, it is necessary that
1728 every call_expr be annotated with file and line. */
1729 if (! EXPR_HAS_LOCATION (*expr_p))
1730 SET_EXPR_LOCATION (*expr_p, input_location);
1732 /* This may be a call to a builtin function.
1734 Builtin function calls may be transformed into different
1735 (and more efficient) builtin function calls under certain
1736 circumstances. Unfortunately, gimplification can muck things
1737 up enough that the builtin expanders are not aware that certain
1738 transformations are still valid.
1740 So we attempt transformation/gimplification of the call before
1741 we gimplify the CALL_EXPR. At this time we do not manage to
1742 transform all calls in the same manner as the expanders do, but
1743 we do transform most of them. */
1744 decl = get_callee_fndecl (*expr_p);
1745 if (decl && DECL_BUILT_IN (decl))
1747 tree fndecl = get_callee_fndecl (*expr_p);
1748 tree arglist = TREE_OPERAND (*expr_p, 1);
1749 tree new = fold_builtin (fndecl, arglist, !want_value);
1751 if (new && new != *expr_p)
1753 /* There was a transformation of this call which computes the
1754 same value, but in a more efficient way. Return and try
1755 again. */
1756 *expr_p = new;
1757 return GS_OK;
1760 if (DECL_BUILT_IN_CLASS (decl) == BUILT_IN_NORMAL
1761 && DECL_FUNCTION_CODE (decl) == BUILT_IN_VA_START)
1763 if (!arglist || !TREE_CHAIN (arglist))
1765 error ("too few arguments to function %<va_start%>");
1766 *expr_p = build_empty_stmt ();
1767 return GS_OK;
1770 if (fold_builtin_next_arg (TREE_CHAIN (arglist)))
1772 *expr_p = build_empty_stmt ();
1773 return GS_OK;
1775 /* Avoid gimplifying the second argument to va_start, which needs
1776 to be the plain PARM_DECL. */
1777 return gimplify_arg (&TREE_VALUE (TREE_OPERAND (*expr_p, 1)), pre_p);
1781 /* There is a sequence point before the call, so any side effects in
1782 the calling expression must occur before the actual call. Force
1783 gimplify_expr to use an internal post queue. */
1784 ret = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p, NULL,
1785 is_gimple_call_addr, fb_rvalue);
1787 if (PUSH_ARGS_REVERSED)
1788 TREE_OPERAND (*expr_p, 1) = nreverse (TREE_OPERAND (*expr_p, 1));
1789 for (arglist = TREE_OPERAND (*expr_p, 1); arglist;
1790 arglist = TREE_CHAIN (arglist))
1792 enum gimplify_status t;
1794 t = gimplify_arg (&TREE_VALUE (arglist), pre_p);
1796 if (t == GS_ERROR)
1797 ret = GS_ERROR;
1799 if (PUSH_ARGS_REVERSED)
1800 TREE_OPERAND (*expr_p, 1) = nreverse (TREE_OPERAND (*expr_p, 1));
1802 /* Try this again in case gimplification exposed something. */
1803 if (ret != GS_ERROR && decl && DECL_BUILT_IN (decl))
1805 tree fndecl = get_callee_fndecl (*expr_p);
1806 tree arglist = TREE_OPERAND (*expr_p, 1);
1807 tree new = fold_builtin (fndecl, arglist, !want_value);
1809 if (new && new != *expr_p)
1811 /* There was a transformation of this call which computes the
1812 same value, but in a more efficient way. Return and try
1813 again. */
1814 *expr_p = new;
1815 return GS_OK;
1819 /* If the function is "const" or "pure", then clear TREE_SIDE_EFFECTS on its
1820 decl. This allows us to eliminate redundant or useless
1821 calls to "const" functions. */
1822 if (TREE_CODE (*expr_p) == CALL_EXPR
1823 && (call_expr_flags (*expr_p) & (ECF_CONST | ECF_PURE)))
1824 TREE_SIDE_EFFECTS (*expr_p) = 0;
1826 return ret;
1829 /* Handle shortcut semantics in the predicate operand of a COND_EXPR by
1830 rewriting it into multiple COND_EXPRs, and possibly GOTO_EXPRs.
1832 TRUE_LABEL_P and FALSE_LABEL_P point to the labels to jump to if the
1833 condition is true or false, respectively. If null, we should generate
1834 our own to skip over the evaluation of this specific expression.
1836 This function is the tree equivalent of do_jump.
1838 shortcut_cond_r should only be called by shortcut_cond_expr. */
1840 static tree
1841 shortcut_cond_r (tree pred, tree *true_label_p, tree *false_label_p)
1843 tree local_label = NULL_TREE;
1844 tree t, expr = NULL;
1846 /* OK, it's not a simple case; we need to pull apart the COND_EXPR to
1847 retain the shortcut semantics. Just insert the gotos here;
1848 shortcut_cond_expr will append the real blocks later. */
1849 if (TREE_CODE (pred) == TRUTH_ANDIF_EXPR)
1851 /* Turn if (a && b) into
1853 if (a); else goto no;
1854 if (b) goto yes; else goto no;
1855 (no:) */
1857 if (false_label_p == NULL)
1858 false_label_p = &local_label;
1860 t = shortcut_cond_r (TREE_OPERAND (pred, 0), NULL, false_label_p);
1861 append_to_statement_list (t, &expr);
1863 t = shortcut_cond_r (TREE_OPERAND (pred, 1), true_label_p,
1864 false_label_p);
1865 append_to_statement_list (t, &expr);
1867 else if (TREE_CODE (pred) == TRUTH_ORIF_EXPR)
1869 /* Turn if (a || b) into
1871 if (a) goto yes;
1872 if (b) goto yes; else goto no;
1873 (yes:) */
1875 if (true_label_p == NULL)
1876 true_label_p = &local_label;
1878 t = shortcut_cond_r (TREE_OPERAND (pred, 0), true_label_p, NULL);
1879 append_to_statement_list (t, &expr);
1881 t = shortcut_cond_r (TREE_OPERAND (pred, 1), true_label_p,
1882 false_label_p);
1883 append_to_statement_list (t, &expr);
1885 else if (TREE_CODE (pred) == COND_EXPR)
1887 /* As long as we're messing with gotos, turn if (a ? b : c) into
1888 if (a)
1889 if (b) goto yes; else goto no;
1890 else
1891 if (c) goto yes; else goto no; */
1892 expr = build (COND_EXPR, void_type_node, TREE_OPERAND (pred, 0),
1893 shortcut_cond_r (TREE_OPERAND (pred, 1), true_label_p,
1894 false_label_p),
1895 shortcut_cond_r (TREE_OPERAND (pred, 2), true_label_p,
1896 false_label_p));
1898 else
1900 expr = build (COND_EXPR, void_type_node, pred,
1901 build_and_jump (true_label_p),
1902 build_and_jump (false_label_p));
1905 if (local_label)
1907 t = build1 (LABEL_EXPR, void_type_node, local_label);
1908 append_to_statement_list (t, &expr);
1911 return expr;
1914 static tree
1915 shortcut_cond_expr (tree expr)
1917 tree pred = TREE_OPERAND (expr, 0);
1918 tree then_ = TREE_OPERAND (expr, 1);
1919 tree else_ = TREE_OPERAND (expr, 2);
1920 tree true_label, false_label, end_label, t;
1921 tree *true_label_p;
1922 tree *false_label_p;
1923 bool emit_end, emit_false, jump_over_else;
1924 bool then_se = then_ && TREE_SIDE_EFFECTS (then_);
1925 bool else_se = else_ && TREE_SIDE_EFFECTS (else_);
1927 /* First do simple transformations. */
1928 if (!else_se)
1930 /* If there is no 'else', turn (a && b) into if (a) if (b). */
1931 while (TREE_CODE (pred) == TRUTH_ANDIF_EXPR)
1933 TREE_OPERAND (expr, 0) = TREE_OPERAND (pred, 1);
1934 then_ = shortcut_cond_expr (expr);
1935 then_se = then_ && TREE_SIDE_EFFECTS (then_);
1936 pred = TREE_OPERAND (pred, 0);
1937 expr = build (COND_EXPR, void_type_node, pred, then_, NULL_TREE);
1940 if (!then_se)
1942 /* If there is no 'then', turn
1943 if (a || b); else d
1944 into
1945 if (a); else if (b); else d. */
1946 while (TREE_CODE (pred) == TRUTH_ORIF_EXPR)
1948 TREE_OPERAND (expr, 0) = TREE_OPERAND (pred, 1);
1949 else_ = shortcut_cond_expr (expr);
1950 else_se = else_ && TREE_SIDE_EFFECTS (else_);
1951 pred = TREE_OPERAND (pred, 0);
1952 expr = build (COND_EXPR, void_type_node, pred, NULL_TREE, else_);
1956 /* If we're done, great. */
1957 if (TREE_CODE (pred) != TRUTH_ANDIF_EXPR
1958 && TREE_CODE (pred) != TRUTH_ORIF_EXPR)
1959 return expr;
1961 /* Otherwise we need to mess with gotos. Change
1962 if (a) c; else d;
1964 if (a); else goto no;
1965 c; goto end;
1966 no: d; end:
1967 and recursively gimplify the condition. */
1969 true_label = false_label = end_label = NULL_TREE;
1971 /* If our arms just jump somewhere, hijack those labels so we don't
1972 generate jumps to jumps. */
1974 if (then_
1975 && TREE_CODE (then_) == GOTO_EXPR
1976 && TREE_CODE (GOTO_DESTINATION (then_)) == LABEL_DECL)
1978 true_label = GOTO_DESTINATION (then_);
1979 then_ = NULL;
1980 then_se = false;
1983 if (else_
1984 && TREE_CODE (else_) == GOTO_EXPR
1985 && TREE_CODE (GOTO_DESTINATION (else_)) == LABEL_DECL)
1987 false_label = GOTO_DESTINATION (else_);
1988 else_ = NULL;
1989 else_se = false;
1992 /* If we aren't hijacking a label for the 'then' branch, it falls through. */
1993 if (true_label)
1994 true_label_p = &true_label;
1995 else
1996 true_label_p = NULL;
1998 /* The 'else' branch also needs a label if it contains interesting code. */
1999 if (false_label || else_se)
2000 false_label_p = &false_label;
2001 else
2002 false_label_p = NULL;
2004 /* If there was nothing else in our arms, just forward the label(s). */
2005 if (!then_se && !else_se)
2006 return shortcut_cond_r (pred, true_label_p, false_label_p);
2008 /* If our last subexpression already has a terminal label, reuse it. */
2009 if (else_se)
2010 expr = expr_last (else_);
2011 else if (then_se)
2012 expr = expr_last (then_);
2013 else
2014 expr = NULL;
2015 if (expr && TREE_CODE (expr) == LABEL_EXPR)
2016 end_label = LABEL_EXPR_LABEL (expr);
2018 /* If we don't care about jumping to the 'else' branch, jump to the end
2019 if the condition is false. */
2020 if (!false_label_p)
2021 false_label_p = &end_label;
2023 /* We only want to emit these labels if we aren't hijacking them. */
2024 emit_end = (end_label == NULL_TREE);
2025 emit_false = (false_label == NULL_TREE);
2027 /* We only emit the jump over the else clause if we have to--if the
2028 then clause may fall through. Otherwise we can wind up with a
2029 useless jump and a useless label at the end of gimplified code,
2030 which will cause us to think that this conditional as a whole
2031 falls through even if it doesn't. If we then inline a function
2032 which ends with such a condition, that can cause us to issue an
2033 inappropriate warning about control reaching the end of a
2034 non-void function. */
2035 jump_over_else = block_may_fallthru (then_);
2037 pred = shortcut_cond_r (pred, true_label_p, false_label_p);
2039 expr = NULL;
2040 append_to_statement_list (pred, &expr);
2042 append_to_statement_list (then_, &expr);
2043 if (else_se)
2045 if (jump_over_else)
2047 t = build_and_jump (&end_label);
2048 append_to_statement_list (t, &expr);
2050 if (emit_false)
2052 t = build1 (LABEL_EXPR, void_type_node, false_label);
2053 append_to_statement_list (t, &expr);
2055 append_to_statement_list (else_, &expr);
2057 if (emit_end && end_label)
2059 t = build1 (LABEL_EXPR, void_type_node, end_label);
2060 append_to_statement_list (t, &expr);
2063 return expr;
2066 /* EXPR is used in a boolean context; make sure it has BOOLEAN_TYPE. */
2068 static tree
2069 gimple_boolify (tree expr)
2071 tree type = TREE_TYPE (expr);
2073 if (TREE_CODE (type) == BOOLEAN_TYPE)
2074 return expr;
2076 switch (TREE_CODE (expr))
2078 case TRUTH_AND_EXPR:
2079 case TRUTH_OR_EXPR:
2080 case TRUTH_XOR_EXPR:
2081 case TRUTH_ANDIF_EXPR:
2082 case TRUTH_ORIF_EXPR:
2083 /* Also boolify the arguments of truth exprs. */
2084 TREE_OPERAND (expr, 1) = gimple_boolify (TREE_OPERAND (expr, 1));
2085 /* FALLTHRU */
2087 case TRUTH_NOT_EXPR:
2088 TREE_OPERAND (expr, 0) = gimple_boolify (TREE_OPERAND (expr, 0));
2089 /* FALLTHRU */
2091 case EQ_EXPR: case NE_EXPR:
2092 case LE_EXPR: case GE_EXPR: case LT_EXPR: case GT_EXPR:
2093 /* These expressions always produce boolean results. */
2094 TREE_TYPE (expr) = boolean_type_node;
2095 return expr;
2097 default:
2098 /* Other expressions that get here must have boolean values, but
2099 might need to be converted to the appropriate mode. */
2100 return convert (boolean_type_node, expr);
2104 /* Convert the conditional expression pointed by EXPR_P '(p) ? a : b;'
2105 into
2107 if (p) if (p)
2108 t1 = a; a;
2109 else or else
2110 t1 = b; b;
2113 The second form is used when *EXPR_P is of type void.
2115 TARGET is the tree for T1 above.
2117 PRE_P points to the list where side effects that must happen before
2118 *EXPR_P should be stored.
2120 POST_P points to the list where side effects that must happen after
2121 *EXPR_P should be stored. */
2123 static enum gimplify_status
2124 gimplify_cond_expr (tree *expr_p, tree *pre_p, tree *post_p, tree target,
2125 fallback_t fallback)
2127 tree expr = *expr_p;
2128 tree tmp, tmp2, type;
2129 enum gimplify_status ret;
2131 type = TREE_TYPE (expr);
2132 if (!type)
2133 TREE_TYPE (expr) = void_type_node;
2135 /* If this COND_EXPR has a value, copy the values into a temporary within
2136 the arms. */
2137 else if (! VOID_TYPE_P (type))
2139 tree result;
2141 if (target)
2143 ret = gimplify_expr (&target, pre_p, post_p,
2144 is_gimple_min_lval, fb_lvalue);
2145 if (ret != GS_ERROR)
2146 ret = GS_OK;
2147 result = tmp = target;
2148 tmp2 = unshare_expr (target);
2150 else if ((fallback & fb_lvalue) == 0)
2152 result = tmp2 = tmp = create_tmp_var (TREE_TYPE (expr), "iftmp");
2153 ret = GS_ALL_DONE;
2155 else
2157 tree type = build_pointer_type (TREE_TYPE (expr));
2159 if (TREE_TYPE (TREE_OPERAND (expr, 1)) != void_type_node)
2160 TREE_OPERAND (expr, 1) =
2161 build_fold_addr_expr (TREE_OPERAND (expr, 1));
2163 if (TREE_TYPE (TREE_OPERAND (expr, 2)) != void_type_node)
2164 TREE_OPERAND (expr, 2) =
2165 build_fold_addr_expr (TREE_OPERAND (expr, 2));
2167 tmp2 = tmp = create_tmp_var (type, "iftmp");
2169 expr = build (COND_EXPR, void_type_node, TREE_OPERAND (expr, 0),
2170 TREE_OPERAND (expr, 1), TREE_OPERAND (expr, 2));
2172 result = build_fold_indirect_ref (tmp);
2173 ret = GS_ALL_DONE;
2176 /* Build the then clause, 't1 = a;'. But don't build an assignment
2177 if this branch is void; in C++ it can be, if it's a throw. */
2178 if (TREE_TYPE (TREE_OPERAND (expr, 1)) != void_type_node)
2179 TREE_OPERAND (expr, 1)
2180 = build (MODIFY_EXPR, void_type_node, tmp, TREE_OPERAND (expr, 1));
2182 /* Build the else clause, 't1 = b;'. */
2183 if (TREE_TYPE (TREE_OPERAND (expr, 2)) != void_type_node)
2184 TREE_OPERAND (expr, 2)
2185 = build (MODIFY_EXPR, void_type_node, tmp2, TREE_OPERAND (expr, 2));
2187 TREE_TYPE (expr) = void_type_node;
2188 recalculate_side_effects (expr);
2190 /* Move the COND_EXPR to the prequeue. */
2191 gimplify_and_add (expr, pre_p);
2193 *expr_p = result;
2194 return ret;
2197 /* Make sure the condition has BOOLEAN_TYPE. */
2198 TREE_OPERAND (expr, 0) = gimple_boolify (TREE_OPERAND (expr, 0));
2200 /* Break apart && and || conditions. */
2201 if (TREE_CODE (TREE_OPERAND (expr, 0)) == TRUTH_ANDIF_EXPR
2202 || TREE_CODE (TREE_OPERAND (expr, 0)) == TRUTH_ORIF_EXPR)
2204 expr = shortcut_cond_expr (expr);
2206 if (expr != *expr_p)
2208 *expr_p = expr;
2210 /* We can't rely on gimplify_expr to re-gimplify the expanded
2211 form properly, as cleanups might cause the target labels to be
2212 wrapped in a TRY_FINALLY_EXPR. To prevent that, we need to
2213 set up a conditional context. */
2214 gimple_push_condition ();
2215 gimplify_stmt (expr_p);
2216 gimple_pop_condition (pre_p);
2218 return GS_ALL_DONE;
2222 /* Now do the normal gimplification. */
2223 ret = gimplify_expr (&TREE_OPERAND (expr, 0), pre_p, NULL,
2224 is_gimple_condexpr, fb_rvalue);
2226 gimple_push_condition ();
2228 gimplify_to_stmt_list (&TREE_OPERAND (expr, 1));
2229 gimplify_to_stmt_list (&TREE_OPERAND (expr, 2));
2230 recalculate_side_effects (expr);
2232 gimple_pop_condition (pre_p);
2234 if (ret == GS_ERROR)
2236 else if (TREE_SIDE_EFFECTS (TREE_OPERAND (expr, 1)))
2237 ret = GS_ALL_DONE;
2238 else if (TREE_SIDE_EFFECTS (TREE_OPERAND (expr, 2)))
2239 /* Rewrite "if (a); else b" to "if (!a) b" */
2241 TREE_OPERAND (expr, 0) = invert_truthvalue (TREE_OPERAND (expr, 0));
2242 ret = gimplify_expr (&TREE_OPERAND (expr, 0), pre_p, NULL,
2243 is_gimple_condexpr, fb_rvalue);
2245 tmp = TREE_OPERAND (expr, 1);
2246 TREE_OPERAND (expr, 1) = TREE_OPERAND (expr, 2);
2247 TREE_OPERAND (expr, 2) = tmp;
2249 else
2250 /* Both arms are empty; replace the COND_EXPR with its predicate. */
2251 expr = TREE_OPERAND (expr, 0);
2253 *expr_p = expr;
2254 return ret;
2257 /* A subroutine of gimplify_modify_expr. Replace a MODIFY_EXPR with
2258 a call to __builtin_memcpy. */
2260 static enum gimplify_status
2261 gimplify_modify_expr_to_memcpy (tree *expr_p, tree size, bool want_value)
2263 tree args, t, to, to_ptr, from;
2265 to = TREE_OPERAND (*expr_p, 0);
2266 from = TREE_OPERAND (*expr_p, 1);
2268 args = tree_cons (NULL, size, NULL);
2270 t = build_fold_addr_expr (from);
2271 args = tree_cons (NULL, t, args);
2273 to_ptr = build_fold_addr_expr (to);
2274 args = tree_cons (NULL, to_ptr, args);
2275 t = implicit_built_in_decls[BUILT_IN_MEMCPY];
2276 t = build_function_call_expr (t, args);
2278 if (want_value)
2280 t = build1 (NOP_EXPR, TREE_TYPE (to_ptr), t);
2281 t = build1 (INDIRECT_REF, TREE_TYPE (to), t);
2284 *expr_p = t;
2285 return GS_OK;
2288 /* A subroutine of gimplify_modify_expr. Replace a MODIFY_EXPR with
2289 a call to __builtin_memset. In this case we know that the RHS is
2290 a CONSTRUCTOR with an empty element list. */
2292 static enum gimplify_status
2293 gimplify_modify_expr_to_memset (tree *expr_p, tree size, bool want_value)
2295 tree args, t, to, to_ptr;
2297 to = TREE_OPERAND (*expr_p, 0);
2299 args = tree_cons (NULL, size, NULL);
2301 args = tree_cons (NULL, integer_zero_node, args);
2303 to_ptr = build_fold_addr_expr (to);
2304 args = tree_cons (NULL, to_ptr, args);
2305 t = implicit_built_in_decls[BUILT_IN_MEMSET];
2306 t = build_function_call_expr (t, args);
2308 if (want_value)
2310 t = build1 (NOP_EXPR, TREE_TYPE (to_ptr), t);
2311 t = build1 (INDIRECT_REF, TREE_TYPE (to), t);
2314 *expr_p = t;
2315 return GS_OK;
2318 /* A subroutine of gimplify_init_ctor_preeval. Called via walk_tree,
2319 determine, cautiously, if a CONSTRUCTOR overlaps the lhs of an
2320 assignment. Returns non-null if we detect a potential overlap. */
2322 struct gimplify_init_ctor_preeval_data
2324 /* The base decl of the lhs object. May be NULL, in which case we
2325 have to assume the lhs is indirect. */
2326 tree lhs_base_decl;
2328 /* The alias set of the lhs object. */
2329 int lhs_alias_set;
2332 static tree
2333 gimplify_init_ctor_preeval_1 (tree *tp, int *walk_subtrees, void *xdata)
2335 struct gimplify_init_ctor_preeval_data *data
2336 = (struct gimplify_init_ctor_preeval_data *) xdata;
2337 tree t = *tp;
2339 /* If we find the base object, obviously we have overlap. */
2340 if (data->lhs_base_decl == t)
2341 return t;
2343 /* If the constructor component is indirect, determine if we have a
2344 potential overlap with the lhs. The only bits of information we
2345 have to go on at this point are addressability and alias sets. */
2346 if (TREE_CODE (t) == INDIRECT_REF
2347 && (!data->lhs_base_decl || TREE_ADDRESSABLE (data->lhs_base_decl))
2348 && alias_sets_conflict_p (data->lhs_alias_set, get_alias_set (t)))
2349 return t;
2351 if (IS_TYPE_OR_DECL_P (t))
2352 *walk_subtrees = 0;
2353 return NULL;
2356 /* A subroutine of gimplify_init_constructor. Pre-evaluate *EXPR_P,
2357 force values that overlap with the lhs (as described by *DATA)
2358 into temporaries. */
2360 static void
2361 gimplify_init_ctor_preeval (tree *expr_p, tree *pre_p, tree *post_p,
2362 struct gimplify_init_ctor_preeval_data *data)
2364 enum gimplify_status one;
2366 /* If the value is invariant, then there's nothing to pre-evaluate.
2367 But ensure it doesn't have any side-effects since a SAVE_EXPR is
2368 invariant but has side effects and might contain a reference to
2369 the object we're initializing. */
2370 if (TREE_INVARIANT (*expr_p) && !TREE_SIDE_EFFECTS (*expr_p))
2371 return;
2373 /* If the type has non-trivial constructors, we can't pre-evaluate. */
2374 if (TREE_ADDRESSABLE (TREE_TYPE (*expr_p)))
2375 return;
2377 /* Recurse for nested constructors. */
2378 if (TREE_CODE (*expr_p) == CONSTRUCTOR)
2380 tree list;
2381 for (list = CONSTRUCTOR_ELTS (*expr_p); list ; list = TREE_CHAIN (list))
2382 gimplify_init_ctor_preeval (&TREE_VALUE (list), pre_p, post_p, data);
2383 return;
2386 /* We can't preevaluate if the type contains a placeholder. */
2387 if (type_contains_placeholder_p (TREE_TYPE (*expr_p)))
2388 return;
2390 /* Gimplify the constructor element to something appropriate for the rhs
2391 of a MODIFY_EXPR. Given that we know the lhs is an aggregate, we know
2392 the gimplifier will consider this a store to memory. Doing this
2393 gimplification now means that we won't have to deal with complicated
2394 language-specific trees, nor trees like SAVE_EXPR that can induce
2395 exponential search behavior. */
2396 one = gimplify_expr (expr_p, pre_p, post_p, is_gimple_mem_rhs, fb_rvalue);
2397 if (one == GS_ERROR)
2399 *expr_p = NULL;
2400 return;
2403 /* If we gimplified to a bare decl, we can be sure that it doesn't overlap
2404 with the lhs, since "a = { .x=a }" doesn't make sense. This will
2405 always be true for all scalars, since is_gimple_mem_rhs insists on a
2406 temporary variable for them. */
2407 if (DECL_P (*expr_p))
2408 return;
2410 /* If this is of variable size, we have no choice but to assume it doesn't
2411 overlap since we can't make a temporary for it. */
2412 if (!TREE_CONSTANT (TYPE_SIZE (TREE_TYPE (*expr_p))))
2413 return;
2415 /* Otherwise, we must search for overlap ... */
2416 if (!walk_tree (expr_p, gimplify_init_ctor_preeval_1, data, NULL))
2417 return;
2419 /* ... and if found, force the value into a temporary. */
2420 *expr_p = get_formal_tmp_var (*expr_p, pre_p);
2423 /* A subroutine of gimplify_init_ctor_eval. Create a loop for
2424 a RANGE_EXPR in a CONSTRUCTOR for an array.
2426 var = lower;
2427 loop_entry:
2428 object[var] = value;
2429 if (var == upper)
2430 goto loop_exit;
2431 var = var + 1;
2432 goto loop_entry;
2433 loop_exit:
2435 We increment var _after_ the loop exit check because we might otherwise
2436 fail if upper == TYPE_MAX_VALUE (type for upper).
2438 Note that we never have to deal with SAVE_EXPRs here, because this has
2439 already been taken care of for us, in gimplify_init_ctor_preeval(). */
2441 static void gimplify_init_ctor_eval (tree, tree, tree *, bool);
2443 static void
2444 gimplify_init_ctor_eval_range (tree object, tree lower, tree upper,
2445 tree value, tree array_elt_type,
2446 tree *pre_p, bool cleared)
2448 tree loop_entry_label, loop_exit_label;
2449 tree var, var_type, cref;
2451 loop_entry_label = create_artificial_label ();
2452 loop_exit_label = create_artificial_label ();
2454 /* Create and initialize the index variable. */
2455 var_type = TREE_TYPE (upper);
2456 var = create_tmp_var (var_type, NULL);
2457 append_to_statement_list (build2 (MODIFY_EXPR, var_type, var, lower), pre_p);
2459 /* Add the loop entry label. */
2460 append_to_statement_list (build1 (LABEL_EXPR,
2461 void_type_node,
2462 loop_entry_label),
2463 pre_p);
2465 /* Build the reference. */
2466 cref = build4 (ARRAY_REF, array_elt_type, unshare_expr (object),
2467 var, NULL_TREE, NULL_TREE);
2469 /* If we are a constructor, just call gimplify_init_ctor_eval to do
2470 the store. Otherwise just assign value to the reference. */
2472 if (TREE_CODE (value) == CONSTRUCTOR)
2473 /* NB we might have to call ourself recursively through
2474 gimplify_init_ctor_eval if the value is a constructor. */
2475 gimplify_init_ctor_eval (cref, CONSTRUCTOR_ELTS (value),
2476 pre_p, cleared);
2477 else
2478 append_to_statement_list (build2 (MODIFY_EXPR, TREE_TYPE (cref),
2479 cref, value),
2480 pre_p);
2482 /* We exit the loop when the index var is equal to the upper bound. */
2483 gimplify_and_add (build3 (COND_EXPR, void_type_node,
2484 build2 (EQ_EXPR, boolean_type_node,
2485 var, upper),
2486 build1 (GOTO_EXPR,
2487 void_type_node,
2488 loop_exit_label),
2489 NULL_TREE),
2490 pre_p);
2492 /* Otherwise, increment the index var... */
2493 append_to_statement_list (build2 (MODIFY_EXPR, var_type, var,
2494 build2 (PLUS_EXPR, var_type, var,
2495 fold_convert (var_type,
2496 integer_one_node))),
2497 pre_p);
2499 /* ...and jump back to the loop entry. */
2500 append_to_statement_list (build1 (GOTO_EXPR,
2501 void_type_node,
2502 loop_entry_label),
2503 pre_p);
2505 /* Add the loop exit label. */
2506 append_to_statement_list (build1 (LABEL_EXPR,
2507 void_type_node,
2508 loop_exit_label),
2509 pre_p);
2512 /* A subroutine of gimplify_init_constructor. Generate individual
2513 MODIFY_EXPRs for a CONSTRUCTOR. OBJECT is the LHS against which the
2514 assignments should happen. LIST is the CONSTRUCTOR_ELTS of the
2515 CONSTRUCTOR. CLEARED is true if the entire LHS object has been
2516 zeroed first. */
2518 static void
2519 gimplify_init_ctor_eval (tree object, tree list, tree *pre_p, bool cleared)
2521 tree array_elt_type = NULL;
2523 if (TREE_CODE (TREE_TYPE (object)) == ARRAY_TYPE)
2524 array_elt_type = TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (object)));
2526 for (; list; list = TREE_CHAIN (list))
2528 tree purpose, value, cref, init;
2530 purpose = TREE_PURPOSE (list);
2531 value = TREE_VALUE (list);
2533 /* NULL values are created above for gimplification errors. */
2534 if (value == NULL)
2535 continue;
2537 if (cleared && initializer_zerop (value))
2538 continue;
2540 /* ??? Here's to hoping the front end fills in all of the indices,
2541 so we don't have to figure out what's missing ourselves. */
2542 gcc_assert (purpose);
2544 /* If we have a RANGE_EXPR, we have to build a loop to assign the
2545 whole range. */
2546 if (TREE_CODE (purpose) == RANGE_EXPR)
2548 tree lower = TREE_OPERAND (purpose, 0);
2549 tree upper = TREE_OPERAND (purpose, 1);
2551 /* If the lower bound is equal to upper, just treat it as if
2552 upper was the index. */
2553 if (simple_cst_equal (lower, upper))
2554 purpose = upper;
2555 else
2557 gimplify_init_ctor_eval_range (object, lower, upper, value,
2558 array_elt_type, pre_p, cleared);
2559 continue;
2563 if (array_elt_type)
2565 cref = build (ARRAY_REF, array_elt_type, unshare_expr (object),
2566 purpose, NULL_TREE, NULL_TREE);
2568 else
2569 cref = build (COMPONENT_REF, TREE_TYPE (purpose),
2570 unshare_expr (object), purpose, NULL_TREE);
2572 if (TREE_CODE (value) == CONSTRUCTOR)
2573 gimplify_init_ctor_eval (cref, CONSTRUCTOR_ELTS (value),
2574 pre_p, cleared);
2575 else
2577 init = build (MODIFY_EXPR, TREE_TYPE (cref), cref, value);
2578 gimplify_and_add (init, pre_p);
2583 /* A subroutine of gimplify_modify_expr. Break out elements of a
2584 CONSTRUCTOR used as an initializer into separate MODIFY_EXPRs.
2586 Note that we still need to clear any elements that don't have explicit
2587 initializers, so if not all elements are initialized we keep the
2588 original MODIFY_EXPR, we just remove all of the constructor elements. */
2590 static enum gimplify_status
2591 gimplify_init_constructor (tree *expr_p, tree *pre_p,
2592 tree *post_p, bool want_value)
2594 tree object;
2595 tree ctor = TREE_OPERAND (*expr_p, 1);
2596 tree type = TREE_TYPE (ctor);
2597 enum gimplify_status ret;
2598 tree elt_list;
2600 if (TREE_CODE (ctor) != CONSTRUCTOR)
2601 return GS_UNHANDLED;
2603 ret = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p, post_p,
2604 is_gimple_lvalue, fb_lvalue);
2605 if (ret == GS_ERROR)
2606 return ret;
2607 object = TREE_OPERAND (*expr_p, 0);
2609 elt_list = CONSTRUCTOR_ELTS (ctor);
2611 ret = GS_ALL_DONE;
2612 switch (TREE_CODE (type))
2614 case RECORD_TYPE:
2615 case UNION_TYPE:
2616 case QUAL_UNION_TYPE:
2617 case ARRAY_TYPE:
2619 struct gimplify_init_ctor_preeval_data preeval_data;
2620 HOST_WIDE_INT num_type_elements, num_ctor_elements;
2621 HOST_WIDE_INT num_nonzero_elements, num_nonconstant_elements;
2622 bool cleared;
2624 /* Aggregate types must lower constructors to initialization of
2625 individual elements. The exception is that a CONSTRUCTOR node
2626 with no elements indicates zero-initialization of the whole. */
2627 if (elt_list == NULL)
2628 break;
2630 categorize_ctor_elements (ctor, &num_nonzero_elements,
2631 &num_nonconstant_elements,
2632 &num_ctor_elements, &cleared);
2634 /* If a const aggregate variable is being initialized, then it
2635 should never be a lose to promote the variable to be static. */
2636 if (num_nonconstant_elements == 0
2637 && num_nonzero_elements > 1
2638 && TREE_READONLY (object)
2639 && TREE_CODE (object) == VAR_DECL)
2641 DECL_INITIAL (object) = ctor;
2642 TREE_STATIC (object) = 1;
2643 if (!DECL_NAME (object))
2644 DECL_NAME (object) = create_tmp_var_name ("C");
2645 walk_tree (&DECL_INITIAL (object), force_labels_r, NULL, NULL);
2647 /* ??? C++ doesn't automatically append a .<number> to the
2648 assembler name, and even when it does, it looks a FE private
2649 data structures to figure out what that number should be,
2650 which are not set for this variable. I suppose this is
2651 important for local statics for inline functions, which aren't
2652 "local" in the object file sense. So in order to get a unique
2653 TU-local symbol, we must invoke the lhd version now. */
2654 lhd_set_decl_assembler_name (object);
2656 *expr_p = NULL_TREE;
2657 break;
2660 /* If there are "lots" of initialized elements, and all of them
2661 are valid address constants, then the entire initializer can
2662 be dropped to memory, and then memcpy'd out. */
2663 if (num_nonconstant_elements == 0)
2665 HOST_WIDE_INT size = int_size_in_bytes (type);
2666 unsigned int align;
2668 /* ??? We can still get unbounded array types, at least
2669 from the C++ front end. This seems wrong, but attempt
2670 to work around it for now. */
2671 if (size < 0)
2673 size = int_size_in_bytes (TREE_TYPE (object));
2674 if (size >= 0)
2675 TREE_TYPE (ctor) = type = TREE_TYPE (object);
2678 /* Find the maximum alignment we can assume for the object. */
2679 /* ??? Make use of DECL_OFFSET_ALIGN. */
2680 if (DECL_P (object))
2681 align = DECL_ALIGN (object);
2682 else
2683 align = TYPE_ALIGN (type);
2685 if (size > 0 && !can_move_by_pieces (size, align))
2687 tree new = create_tmp_var_raw (type, "C");
2689 gimple_add_tmp_var (new);
2690 TREE_STATIC (new) = 1;
2691 TREE_READONLY (new) = 1;
2692 DECL_INITIAL (new) = ctor;
2693 if (align > DECL_ALIGN (new))
2695 DECL_ALIGN (new) = align;
2696 DECL_USER_ALIGN (new) = 1;
2698 walk_tree (&DECL_INITIAL (new), force_labels_r, NULL, NULL);
2700 TREE_OPERAND (*expr_p, 1) = new;
2702 /* This is no longer an assignment of a CONSTRUCTOR, but
2703 we still may have processing to do on the LHS. So
2704 pretend we didn't do anything here to let that happen. */
2705 return GS_UNHANDLED;
2709 /* If there are "lots" of initialized elements, even discounting
2710 those that are not address constants (and thus *must* be
2711 computed at runtime), then partition the constructor into
2712 constant and non-constant parts. Block copy the constant
2713 parts in, then generate code for the non-constant parts. */
2714 /* TODO. There's code in cp/typeck.c to do this. */
2716 num_type_elements = count_type_elements (TREE_TYPE (ctor));
2718 /* If there are "lots" of zeros, then block clear the object first. */
2719 if (num_type_elements - num_nonzero_elements > CLEAR_RATIO
2720 && num_nonzero_elements < num_type_elements/4)
2721 cleared = true;
2723 /* ??? This bit ought not be needed. For any element not present
2724 in the initializer, we should simply set them to zero. Except
2725 we'd need to *find* the elements that are not present, and that
2726 requires trickery to avoid quadratic compile-time behavior in
2727 large cases or excessive memory use in small cases. */
2728 else if (num_ctor_elements < num_type_elements)
2729 cleared = true;
2731 if (cleared)
2733 /* Zap the CONSTRUCTOR element list, which simplifies this case.
2734 Note that we still have to gimplify, in order to handle the
2735 case of variable sized types. Avoid shared tree structures. */
2736 CONSTRUCTOR_ELTS (ctor) = NULL_TREE;
2737 object = unshare_expr (object);
2738 gimplify_stmt (expr_p);
2739 append_to_statement_list (*expr_p, pre_p);
2742 /* If we have not block cleared the object, or if there are nonzero
2743 elements in the constructor, add assignments to the individual
2744 scalar fields of the object. */
2745 if (!cleared || num_nonzero_elements > 0)
2747 preeval_data.lhs_base_decl = get_base_address (object);
2748 if (!DECL_P (preeval_data.lhs_base_decl))
2749 preeval_data.lhs_base_decl = NULL;
2750 preeval_data.lhs_alias_set = get_alias_set (object);
2752 gimplify_init_ctor_preeval (&TREE_OPERAND (*expr_p, 1),
2753 pre_p, post_p, &preeval_data);
2754 gimplify_init_ctor_eval (object, elt_list, pre_p, cleared);
2757 *expr_p = NULL_TREE;
2759 break;
2761 case COMPLEX_TYPE:
2763 tree r, i;
2765 /* Extract the real and imaginary parts out of the ctor. */
2766 r = i = NULL_TREE;
2767 if (elt_list)
2769 r = TREE_VALUE (elt_list);
2770 elt_list = TREE_CHAIN (elt_list);
2771 if (elt_list)
2773 i = TREE_VALUE (elt_list);
2774 gcc_assert (!TREE_CHAIN (elt_list));
2777 if (r == NULL || i == NULL)
2779 tree zero = convert (TREE_TYPE (type), integer_zero_node);
2780 if (r == NULL)
2781 r = zero;
2782 if (i == NULL)
2783 i = zero;
2786 /* Complex types have either COMPLEX_CST or COMPLEX_EXPR to
2787 represent creation of a complex value. */
2788 if (TREE_CONSTANT (r) && TREE_CONSTANT (i))
2790 ctor = build_complex (type, r, i);
2791 TREE_OPERAND (*expr_p, 1) = ctor;
2793 else
2795 ctor = build (COMPLEX_EXPR, type, r, i);
2796 TREE_OPERAND (*expr_p, 1) = ctor;
2797 ret = gimplify_expr (&TREE_OPERAND (*expr_p, 1), pre_p, post_p,
2798 rhs_predicate_for (TREE_OPERAND (*expr_p, 0)),
2799 fb_rvalue);
2802 break;
2804 case VECTOR_TYPE:
2805 /* Go ahead and simplify constant constructors to VECTOR_CST. */
2806 if (TREE_CONSTANT (ctor))
2808 tree tem;
2810 /* Even when ctor is constant, it might contain non-*_CST
2811 elements (e.g. { 1.0/0.0 - 1.0/0.0, 0.0 }) and those don't
2812 belong into VECTOR_CST nodes. */
2813 for (tem = elt_list; tem; tem = TREE_CHAIN (tem))
2814 if (! CONSTANT_CLASS_P (TREE_VALUE (tem)))
2815 break;
2817 if (! tem)
2819 TREE_OPERAND (*expr_p, 1) = build_vector (type, elt_list);
2820 break;
2824 /* Vector types use CONSTRUCTOR all the way through gimple
2825 compilation as a general initializer. */
2826 for (; elt_list; elt_list = TREE_CHAIN (elt_list))
2828 enum gimplify_status tret;
2829 tret = gimplify_expr (&TREE_VALUE (elt_list), pre_p, post_p,
2830 is_gimple_val, fb_rvalue);
2831 if (tret == GS_ERROR)
2832 ret = GS_ERROR;
2834 break;
2836 default:
2837 /* So how did we get a CONSTRUCTOR for a scalar type? */
2838 gcc_unreachable ();
2841 if (ret == GS_ERROR)
2842 return GS_ERROR;
2843 else if (want_value)
2845 append_to_statement_list (*expr_p, pre_p);
2846 *expr_p = object;
2847 return GS_OK;
2849 else
2850 return GS_ALL_DONE;
2853 /* Subroutine of gimplify_modify_expr to do simplifications of MODIFY_EXPRs
2854 based on the code of the RHS. We loop for as long as something changes. */
2856 static enum gimplify_status
2857 gimplify_modify_expr_rhs (tree *expr_p, tree *from_p, tree *to_p, tree *pre_p,
2858 tree *post_p, bool want_value)
2860 enum gimplify_status ret = GS_OK;
2862 while (ret != GS_UNHANDLED)
2863 switch (TREE_CODE (*from_p))
2865 case INDIRECT_REF:
2867 /* If we have code like
2869 *(const A*)(A*)&x
2871 where the type of "x" is a (possibly cv-qualified variant
2872 of "A"), treat the entire expression as identical to "x".
2873 This kind of code arises in C++ when an object is bound
2874 to a const reference, and if "x" is a TARGET_EXPR we want
2875 to take advantage of the optimization below. */
2876 tree t = fold_indirect_ref (*from_p);
2877 if (t != *from_p)
2879 *from_p = t;
2880 ret = GS_OK;
2882 else
2883 ret = GS_UNHANDLED;
2884 break;
2887 case TARGET_EXPR:
2889 /* If we are initializing something from a TARGET_EXPR, strip the
2890 TARGET_EXPR and initialize it directly, if possible. This can't
2891 be done if the initializer is void, since that implies that the
2892 temporary is set in some non-trivial way.
2894 ??? What about code that pulls out the temp and uses it
2895 elsewhere? I think that such code never uses the TARGET_EXPR as
2896 an initializer. If I'm wrong, we'll die because the temp won't
2897 have any RTL. In that case, I guess we'll need to replace
2898 references somehow. */
2899 tree init = TARGET_EXPR_INITIAL (*from_p);
2901 if (!VOID_TYPE_P (TREE_TYPE (init)))
2903 *from_p = init;
2904 ret = GS_OK;
2906 else
2907 ret = GS_UNHANDLED;
2909 break;
2911 case COMPOUND_EXPR:
2912 /* Remove any COMPOUND_EXPR in the RHS so the following cases will be
2913 caught. */
2914 gimplify_compound_expr (from_p, pre_p, true);
2915 ret = GS_OK;
2916 break;
2918 case CONSTRUCTOR:
2919 /* If we're initializing from a CONSTRUCTOR, break this into
2920 individual MODIFY_EXPRs. */
2921 return gimplify_init_constructor (expr_p, pre_p, post_p, want_value);
2923 case COND_EXPR:
2924 /* If we're assigning to a non-register type, push the assignment
2925 down into the branches. This is mandatory for ADDRESSABLE types,
2926 since we cannot generate temporaries for such, but it saves a
2927 copy in other cases as well. */
2928 if (!is_gimple_reg_type (TREE_TYPE (*from_p)))
2930 *expr_p = *from_p;
2931 return gimplify_cond_expr (expr_p, pre_p, post_p, *to_p,
2932 fb_rvalue);
2934 else
2935 ret = GS_UNHANDLED;
2936 break;
2938 default:
2939 ret = GS_UNHANDLED;
2940 break;
2943 return ret;
2946 /* Gimplify the MODIFY_EXPR node pointed by EXPR_P.
2948 modify_expr
2949 : varname '=' rhs
2950 | '*' ID '=' rhs
2952 PRE_P points to the list where side effects that must happen before
2953 *EXPR_P should be stored.
2955 POST_P points to the list where side effects that must happen after
2956 *EXPR_P should be stored.
2958 WANT_VALUE is nonzero iff we want to use the value of this expression
2959 in another expression. */
2961 static enum gimplify_status
2962 gimplify_modify_expr (tree *expr_p, tree *pre_p, tree *post_p, bool want_value)
2964 tree *from_p = &TREE_OPERAND (*expr_p, 1);
2965 tree *to_p = &TREE_OPERAND (*expr_p, 0);
2966 enum gimplify_status ret = GS_UNHANDLED;
2968 gcc_assert (TREE_CODE (*expr_p) == MODIFY_EXPR
2969 || TREE_CODE (*expr_p) == INIT_EXPR);
2971 /* The distinction between MODIFY_EXPR and INIT_EXPR is no longer useful. */
2972 if (TREE_CODE (*expr_p) == INIT_EXPR)
2973 TREE_SET_CODE (*expr_p, MODIFY_EXPR);
2975 /* See if any simplifications can be done based on what the RHS is. */
2976 ret = gimplify_modify_expr_rhs (expr_p, from_p, to_p, pre_p, post_p,
2977 want_value);
2978 if (ret != GS_UNHANDLED)
2979 return ret;
2981 /* If the value being copied is of variable width, compute the length
2982 of the copy into a WITH_SIZE_EXPR. Note that we need to do this
2983 before gimplifying any of the operands so that we can resolve any
2984 PLACEHOLDER_EXPRs in the size. Also note that the RTL expander uses
2985 the size of the expression to be copied, not of the destination, so
2986 that is what we must here. */
2987 maybe_with_size_expr (from_p);
2989 ret = gimplify_expr (to_p, pre_p, post_p, is_gimple_lvalue, fb_lvalue);
2990 if (ret == GS_ERROR)
2991 return ret;
2993 ret = gimplify_expr (from_p, pre_p, post_p,
2994 rhs_predicate_for (*to_p), fb_rvalue);
2995 if (ret == GS_ERROR)
2996 return ret;
2998 /* Now see if the above changed *from_p to something we handle specially. */
2999 ret = gimplify_modify_expr_rhs (expr_p, from_p, to_p, pre_p, post_p,
3000 want_value);
3001 if (ret != GS_UNHANDLED)
3002 return ret;
3004 /* If we've got a variable sized assignment between two lvalues (i.e. does
3005 not involve a call), then we can make things a bit more straightforward
3006 by converting the assignment to memcpy or memset. */
3007 if (TREE_CODE (*from_p) == WITH_SIZE_EXPR)
3009 tree from = TREE_OPERAND (*from_p, 0);
3010 tree size = TREE_OPERAND (*from_p, 1);
3012 if (TREE_CODE (from) == CONSTRUCTOR)
3013 return gimplify_modify_expr_to_memset (expr_p, size, want_value);
3014 if (is_gimple_addressable (from))
3016 *from_p = from;
3017 return gimplify_modify_expr_to_memcpy (expr_p, size, want_value);
3021 if (gimplify_ctxp->into_ssa && is_gimple_reg (*to_p))
3023 /* If we've somehow already got an SSA_NAME on the LHS, then
3024 we're probably modifying it twice. Not good. */
3025 gcc_assert (TREE_CODE (*to_p) != SSA_NAME);
3026 *to_p = make_ssa_name (*to_p, *expr_p);
3029 if (want_value)
3031 append_to_statement_list (*expr_p, pre_p);
3032 *expr_p = *to_p;
3033 return GS_OK;
3036 return GS_ALL_DONE;
3039 /* Gimplify a comparison between two variable-sized objects. Do this
3040 with a call to BUILT_IN_MEMCMP. */
3042 static enum gimplify_status
3043 gimplify_variable_sized_compare (tree *expr_p)
3045 tree op0 = TREE_OPERAND (*expr_p, 0);
3046 tree op1 = TREE_OPERAND (*expr_p, 1);
3047 tree args, t, dest;
3049 t = TYPE_SIZE_UNIT (TREE_TYPE (op0));
3050 t = unshare_expr (t);
3051 t = SUBSTITUTE_PLACEHOLDER_IN_EXPR (t, op0);
3052 args = tree_cons (NULL, t, NULL);
3053 t = build_fold_addr_expr (op1);
3054 args = tree_cons (NULL, t, args);
3055 dest = build_fold_addr_expr (op0);
3056 args = tree_cons (NULL, dest, args);
3057 t = implicit_built_in_decls[BUILT_IN_MEMCMP];
3058 t = build_function_call_expr (t, args);
3059 *expr_p
3060 = build (TREE_CODE (*expr_p), TREE_TYPE (*expr_p), t, integer_zero_node);
3062 return GS_OK;
3065 /* Gimplify TRUTH_ANDIF_EXPR and TRUTH_ORIF_EXPR expressions. EXPR_P
3066 points to the expression to gimplify.
3068 Expressions of the form 'a && b' are gimplified to:
3070 a && b ? true : false
3072 gimplify_cond_expr will do the rest.
3074 PRE_P points to the list where side effects that must happen before
3075 *EXPR_P should be stored. */
3077 static enum gimplify_status
3078 gimplify_boolean_expr (tree *expr_p)
3080 /* Preserve the original type of the expression. */
3081 tree type = TREE_TYPE (*expr_p);
3083 *expr_p = build (COND_EXPR, type, *expr_p,
3084 convert (type, boolean_true_node),
3085 convert (type, boolean_false_node));
3087 return GS_OK;
3090 /* Gimplifies an expression sequence. This function gimplifies each
3091 expression and re-writes the original expression with the last
3092 expression of the sequence in GIMPLE form.
3094 PRE_P points to the list where the side effects for all the
3095 expressions in the sequence will be emitted.
3097 WANT_VALUE is true when the result of the last COMPOUND_EXPR is used. */
3098 /* ??? Should rearrange to share the pre-queue with all the indirect
3099 invocations of gimplify_expr. Would probably save on creations
3100 of statement_list nodes. */
3102 static enum gimplify_status
3103 gimplify_compound_expr (tree *expr_p, tree *pre_p, bool want_value)
3105 tree t = *expr_p;
3109 tree *sub_p = &TREE_OPERAND (t, 0);
3111 if (TREE_CODE (*sub_p) == COMPOUND_EXPR)
3112 gimplify_compound_expr (sub_p, pre_p, false);
3113 else
3114 gimplify_stmt (sub_p);
3115 append_to_statement_list (*sub_p, pre_p);
3117 t = TREE_OPERAND (t, 1);
3119 while (TREE_CODE (t) == COMPOUND_EXPR);
3121 *expr_p = t;
3122 if (want_value)
3123 return GS_OK;
3124 else
3126 gimplify_stmt (expr_p);
3127 return GS_ALL_DONE;
3131 /* Gimplifies a statement list. These may be created either by an
3132 enlightened front-end, or by shortcut_cond_expr. */
3134 static enum gimplify_status
3135 gimplify_statement_list (tree *expr_p)
3137 tree_stmt_iterator i = tsi_start (*expr_p);
3139 while (!tsi_end_p (i))
3141 tree t;
3143 gimplify_stmt (tsi_stmt_ptr (i));
3145 t = tsi_stmt (i);
3146 if (t == NULL)
3147 tsi_delink (&i);
3148 else if (TREE_CODE (t) == STATEMENT_LIST)
3150 tsi_link_before (&i, t, TSI_SAME_STMT);
3151 tsi_delink (&i);
3153 else
3154 tsi_next (&i);
3157 return GS_ALL_DONE;
3160 /* Gimplify a SAVE_EXPR node. EXPR_P points to the expression to
3161 gimplify. After gimplification, EXPR_P will point to a new temporary
3162 that holds the original value of the SAVE_EXPR node.
3164 PRE_P points to the list where side effects that must happen before
3165 *EXPR_P should be stored. */
3167 static enum gimplify_status
3168 gimplify_save_expr (tree *expr_p, tree *pre_p, tree *post_p)
3170 enum gimplify_status ret = GS_ALL_DONE;
3171 tree val;
3173 gcc_assert (TREE_CODE (*expr_p) == SAVE_EXPR);
3174 val = TREE_OPERAND (*expr_p, 0);
3176 /* If the SAVE_EXPR has not been resolved, then evaluate it once. */
3177 if (!SAVE_EXPR_RESOLVED_P (*expr_p))
3179 /* The operand may be a void-valued expression such as SAVE_EXPRs
3180 generated by the Java frontend for class initialization. It is
3181 being executed only for its side-effects. */
3182 if (TREE_TYPE (val) == void_type_node)
3184 ret = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p, post_p,
3185 is_gimple_stmt, fb_none);
3186 append_to_statement_list (TREE_OPERAND (*expr_p, 0), pre_p);
3187 val = NULL;
3189 else
3190 val = get_initialized_tmp_var (val, pre_p, post_p);
3192 TREE_OPERAND (*expr_p, 0) = val;
3193 SAVE_EXPR_RESOLVED_P (*expr_p) = 1;
3196 *expr_p = val;
3198 return ret;
3201 /* Re-write the ADDR_EXPR node pointed by EXPR_P
3203 unary_expr
3204 : ...
3205 | '&' varname
3208 PRE_P points to the list where side effects that must happen before
3209 *EXPR_P should be stored.
3211 POST_P points to the list where side effects that must happen after
3212 *EXPR_P should be stored. */
3214 static enum gimplify_status
3215 gimplify_addr_expr (tree *expr_p, tree *pre_p, tree *post_p)
3217 tree expr = *expr_p;
3218 tree op0 = TREE_OPERAND (expr, 0);
3219 enum gimplify_status ret;
3221 switch (TREE_CODE (op0))
3223 case INDIRECT_REF:
3224 case MISALIGNED_INDIRECT_REF:
3225 do_indirect_ref:
3226 /* Check if we are dealing with an expression of the form '&*ptr'.
3227 While the front end folds away '&*ptr' into 'ptr', these
3228 expressions may be generated internally by the compiler (e.g.,
3229 builtins like __builtin_va_end). */
3230 /* Caution: the silent array decomposition semantics we allow for
3231 ADDR_EXPR means we can't always discard the pair. */
3232 /* Gimplification of the ADDR_EXPR operand may drop
3233 cv-qualification conversions, so make sure we add them if
3234 needed. */
3236 tree op00 = TREE_OPERAND (op0, 0);
3237 tree t_expr = TREE_TYPE (expr);
3238 tree t_op00 = TREE_TYPE (op00);
3240 if (!lang_hooks.types_compatible_p (t_expr, t_op00))
3242 #ifdef ENABLE_CHECKING
3243 tree t_op0 = TREE_TYPE (op0);
3244 gcc_assert (POINTER_TYPE_P (t_expr)
3245 && cpt_same_type (TREE_CODE (t_op0) == ARRAY_TYPE
3246 ? TREE_TYPE (t_op0) : t_op0,
3247 TREE_TYPE (t_expr))
3248 && POINTER_TYPE_P (t_op00)
3249 && cpt_same_type (t_op0, TREE_TYPE (t_op00)));
3250 #endif
3251 op00 = fold_convert (TREE_TYPE (expr), op00);
3253 *expr_p = op00;
3254 ret = GS_OK;
3256 break;
3258 case VIEW_CONVERT_EXPR:
3259 /* Take the address of our operand and then convert it to the type of
3260 this ADDR_EXPR.
3262 ??? The interactions of VIEW_CONVERT_EXPR and aliasing is not at
3263 all clear. The impact of this transformation is even less clear. */
3265 /* If the operand is a useless conversion, look through it. Doing so
3266 guarantees that the ADDR_EXPR and its operand will remain of the
3267 same type. */
3268 if (tree_ssa_useless_type_conversion (TREE_OPERAND (op0, 0)))
3269 op0 = TREE_OPERAND (op0, 0);
3271 *expr_p = fold_convert (TREE_TYPE (expr),
3272 build_fold_addr_expr (TREE_OPERAND (op0, 0)));
3273 ret = GS_OK;
3274 break;
3276 default:
3277 /* We use fb_either here because the C frontend sometimes takes
3278 the address of a call that returns a struct; see
3279 gcc.dg/c99-array-lval-1.c. The gimplifier will correctly make
3280 the implied temporary explicit. */
3281 ret = gimplify_expr (&TREE_OPERAND (expr, 0), pre_p, post_p,
3282 is_gimple_addressable, fb_either);
3283 if (ret != GS_ERROR)
3285 op0 = TREE_OPERAND (expr, 0);
3287 /* For various reasons, the gimplification of the expression
3288 may have made a new INDIRECT_REF. */
3289 if (TREE_CODE (op0) == INDIRECT_REF)
3290 goto do_indirect_ref;
3292 /* Make sure TREE_INVARIANT, TREE_CONSTANT, and TREE_SIDE_EFFECTS
3293 is set properly. */
3294 recompute_tree_invarant_for_addr_expr (expr);
3296 /* Mark the RHS addressable. */
3297 lang_hooks.mark_addressable (TREE_OPERAND (expr, 0));
3299 break;
3302 return ret;
3305 /* Gimplify the operands of an ASM_EXPR. Input operands should be a gimple
3306 value; output operands should be a gimple lvalue. */
3308 static enum gimplify_status
3309 gimplify_asm_expr (tree *expr_p, tree *pre_p, tree *post_p)
3311 tree expr = *expr_p;
3312 int noutputs = list_length (ASM_OUTPUTS (expr));
3313 const char **oconstraints
3314 = (const char **) alloca ((noutputs) * sizeof (const char *));
3315 int i;
3316 tree link;
3317 const char *constraint;
3318 bool allows_mem, allows_reg, is_inout;
3319 enum gimplify_status ret, tret;
3321 ret = GS_ALL_DONE;
3322 for (i = 0, link = ASM_OUTPUTS (expr); link; ++i, link = TREE_CHAIN (link))
3324 size_t constraint_len;
3325 oconstraints[i] = constraint
3326 = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (link)));
3327 constraint_len = strlen (constraint);
3328 if (constraint_len == 0)
3329 continue;
3331 parse_output_constraint (&constraint, i, 0, 0,
3332 &allows_mem, &allows_reg, &is_inout);
3334 if (!allows_reg && allows_mem)
3335 lang_hooks.mark_addressable (TREE_VALUE (link));
3337 tret = gimplify_expr (&TREE_VALUE (link), pre_p, post_p,
3338 is_inout ? is_gimple_min_lval : is_gimple_lvalue,
3339 fb_lvalue | fb_mayfail);
3340 if (tret == GS_ERROR)
3342 error ("invalid lvalue in asm output %d", i);
3343 ret = tret;
3346 if (is_inout)
3348 /* An input/output operand. To give the optimizers more
3349 flexibility, split it into separate input and output
3350 operands. */
3351 tree input;
3352 char buf[10];
3354 /* Turn the in/out constraint into an output constraint. */
3355 char *p = xstrdup (constraint);
3356 p[0] = '=';
3357 TREE_VALUE (TREE_PURPOSE (link)) = build_string (constraint_len, p);
3359 /* And add a matching input constraint. */
3360 if (allows_reg)
3362 sprintf (buf, "%d", i);
3364 /* If there are multiple alternatives in the constraint,
3365 handle each of them individually. Those that allow register
3366 will be replaced with operand number, the others will stay
3367 unchanged. */
3368 if (strchr (p, ',') != NULL)
3370 size_t len = 0, buflen = strlen (buf);
3371 char *beg, *end, *str, *dst;
3373 for (beg = p + 1;;)
3375 end = strchr (beg, ',');
3376 if (end == NULL)
3377 end = strchr (beg, '\0');
3378 if ((size_t) (end - beg) < buflen)
3379 len += buflen + 1;
3380 else
3381 len += end - beg + 1;
3382 if (*end)
3383 beg = end + 1;
3384 else
3385 break;
3388 str = alloca (len);
3389 for (beg = p + 1, dst = str;;)
3391 const char *tem;
3392 bool mem_p, reg_p, inout_p;
3394 end = strchr (beg, ',');
3395 if (end)
3396 *end = '\0';
3397 beg[-1] = '=';
3398 tem = beg - 1;
3399 parse_output_constraint (&tem, i, 0, 0,
3400 &mem_p, &reg_p, &inout_p);
3401 if (dst != str)
3402 *dst++ = ',';
3403 if (reg_p)
3405 memcpy (dst, buf, buflen);
3406 dst += buflen;
3408 else
3410 if (end)
3411 len = end - beg;
3412 else
3413 len = strlen (beg);
3414 memcpy (dst, beg, len);
3415 dst += len;
3417 if (end)
3418 beg = end + 1;
3419 else
3420 break;
3422 *dst = '\0';
3423 input = build_string (dst - str, str);
3425 else
3426 input = build_string (strlen (buf), buf);
3428 else
3429 input = build_string (constraint_len - 1, constraint + 1);
3431 free (p);
3433 input = build_tree_list (build_tree_list (NULL_TREE, input),
3434 unshare_expr (TREE_VALUE (link)));
3435 ASM_INPUTS (expr) = chainon (ASM_INPUTS (expr), input);
3439 for (link = ASM_INPUTS (expr); link; ++i, link = TREE_CHAIN (link))
3441 constraint
3442 = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (link)));
3443 parse_input_constraint (&constraint, 0, 0, noutputs, 0,
3444 oconstraints, &allows_mem, &allows_reg);
3446 /* If the operand is a memory input, it should be an lvalue. */
3447 if (!allows_reg && allows_mem)
3449 lang_hooks.mark_addressable (TREE_VALUE (link));
3450 tret = gimplify_expr (&TREE_VALUE (link), pre_p, post_p,
3451 is_gimple_lvalue, fb_lvalue | fb_mayfail);
3452 if (tret == GS_ERROR)
3454 error ("memory input %d is not directly addressable", i);
3455 ret = tret;
3458 else
3460 tret = gimplify_expr (&TREE_VALUE (link), pre_p, post_p,
3461 is_gimple_asm_val, fb_rvalue);
3462 if (tret == GS_ERROR)
3463 ret = tret;
3467 return ret;
3470 /* Gimplify a CLEANUP_POINT_EXPR. Currently this works by adding
3471 WITH_CLEANUP_EXPRs to the prequeue as we encounter cleanups while
3472 gimplifying the body, and converting them to TRY_FINALLY_EXPRs when we
3473 return to this function.
3475 FIXME should we complexify the prequeue handling instead? Or use flags
3476 for all the cleanups and let the optimizer tighten them up? The current
3477 code seems pretty fragile; it will break on a cleanup within any
3478 non-conditional nesting. But any such nesting would be broken, anyway;
3479 we can't write a TRY_FINALLY_EXPR that starts inside a nesting construct
3480 and continues out of it. We can do that at the RTL level, though, so
3481 having an optimizer to tighten up try/finally regions would be a Good
3482 Thing. */
3484 static enum gimplify_status
3485 gimplify_cleanup_point_expr (tree *expr_p, tree *pre_p)
3487 tree_stmt_iterator iter;
3488 tree body;
3490 tree temp = voidify_wrapper_expr (*expr_p, NULL);
3492 /* We only care about the number of conditions between the innermost
3493 CLEANUP_POINT_EXPR and the cleanup. So save and reset the count. */
3494 int old_conds = gimplify_ctxp->conditions;
3495 gimplify_ctxp->conditions = 0;
3497 body = TREE_OPERAND (*expr_p, 0);
3498 gimplify_to_stmt_list (&body);
3500 gimplify_ctxp->conditions = old_conds;
3502 for (iter = tsi_start (body); !tsi_end_p (iter); )
3504 tree *wce_p = tsi_stmt_ptr (iter);
3505 tree wce = *wce_p;
3507 if (TREE_CODE (wce) == WITH_CLEANUP_EXPR)
3509 if (tsi_one_before_end_p (iter))
3511 tsi_link_before (&iter, TREE_OPERAND (wce, 0), TSI_SAME_STMT);
3512 tsi_delink (&iter);
3513 break;
3515 else
3517 tree sl, tfe;
3518 enum tree_code code;
3520 if (CLEANUP_EH_ONLY (wce))
3521 code = TRY_CATCH_EXPR;
3522 else
3523 code = TRY_FINALLY_EXPR;
3525 sl = tsi_split_statement_list_after (&iter);
3526 tfe = build (code, void_type_node, sl, NULL_TREE);
3527 append_to_statement_list (TREE_OPERAND (wce, 0),
3528 &TREE_OPERAND (tfe, 1));
3529 *wce_p = tfe;
3530 iter = tsi_start (sl);
3533 else
3534 tsi_next (&iter);
3537 if (temp)
3539 *expr_p = temp;
3540 append_to_statement_list (body, pre_p);
3541 return GS_OK;
3543 else
3545 *expr_p = body;
3546 return GS_ALL_DONE;
3550 /* Insert a cleanup marker for gimplify_cleanup_point_expr. CLEANUP
3551 is the cleanup action required. */
3553 static void
3554 gimple_push_cleanup (tree var, tree cleanup, bool eh_only, tree *pre_p)
3556 tree wce;
3558 /* Errors can result in improperly nested cleanups. Which results in
3559 confusion when trying to resolve the WITH_CLEANUP_EXPR. */
3560 if (errorcount || sorrycount)
3561 return;
3563 if (gimple_conditional_context ())
3565 /* If we're in a conditional context, this is more complex. We only
3566 want to run the cleanup if we actually ran the initialization that
3567 necessitates it, but we want to run it after the end of the
3568 conditional context. So we wrap the try/finally around the
3569 condition and use a flag to determine whether or not to actually
3570 run the destructor. Thus
3572 test ? f(A()) : 0
3574 becomes (approximately)
3576 flag = 0;
3577 try {
3578 if (test) { A::A(temp); flag = 1; val = f(temp); }
3579 else { val = 0; }
3580 } finally {
3581 if (flag) A::~A(temp);
3586 tree flag = create_tmp_var (boolean_type_node, "cleanup");
3587 tree ffalse = build (MODIFY_EXPR, void_type_node, flag,
3588 boolean_false_node);
3589 tree ftrue = build (MODIFY_EXPR, void_type_node, flag,
3590 boolean_true_node);
3591 cleanup = build (COND_EXPR, void_type_node, flag, cleanup, NULL);
3592 wce = build (WITH_CLEANUP_EXPR, void_type_node, cleanup);
3593 append_to_statement_list (ffalse, &gimplify_ctxp->conditional_cleanups);
3594 append_to_statement_list (wce, &gimplify_ctxp->conditional_cleanups);
3595 append_to_statement_list (ftrue, pre_p);
3597 /* Because of this manipulation, and the EH edges that jump
3598 threading cannot redirect, the temporary (VAR) will appear
3599 to be used uninitialized. Don't warn. */
3600 TREE_NO_WARNING (var) = 1;
3602 else
3604 wce = build (WITH_CLEANUP_EXPR, void_type_node, cleanup);
3605 CLEANUP_EH_ONLY (wce) = eh_only;
3606 append_to_statement_list (wce, pre_p);
3609 gimplify_stmt (&TREE_OPERAND (wce, 0));
3612 /* Gimplify a TARGET_EXPR which doesn't appear on the rhs of an INIT_EXPR. */
3614 static enum gimplify_status
3615 gimplify_target_expr (tree *expr_p, tree *pre_p, tree *post_p)
3617 tree targ = *expr_p;
3618 tree temp = TARGET_EXPR_SLOT (targ);
3619 tree init = TARGET_EXPR_INITIAL (targ);
3620 enum gimplify_status ret;
3622 if (init)
3624 /* TARGET_EXPR temps aren't part of the enclosing block, so add it
3625 to the temps list. */
3626 gimple_add_tmp_var (temp);
3628 /* If TARGET_EXPR_INITIAL is void, then the mere evaluation of the
3629 expression is supposed to initialize the slot. */
3630 if (VOID_TYPE_P (TREE_TYPE (init)))
3631 ret = gimplify_expr (&init, pre_p, post_p, is_gimple_stmt, fb_none);
3632 else
3634 /* Special handling for BIND_EXPR can result in fewer temps. */
3635 ret = GS_OK;
3636 if (TREE_CODE (init) == BIND_EXPR)
3637 gimplify_bind_expr (&init, temp, pre_p);
3638 if (init != temp)
3640 init = build (MODIFY_EXPR, void_type_node, temp, init);
3641 ret = gimplify_expr (&init, pre_p, post_p, is_gimple_stmt,
3642 fb_none);
3645 if (ret == GS_ERROR)
3646 return GS_ERROR;
3647 append_to_statement_list (init, pre_p);
3649 /* If needed, push the cleanup for the temp. */
3650 if (TARGET_EXPR_CLEANUP (targ))
3652 gimplify_stmt (&TARGET_EXPR_CLEANUP (targ));
3653 gimple_push_cleanup (temp, TARGET_EXPR_CLEANUP (targ),
3654 CLEANUP_EH_ONLY (targ), pre_p);
3657 /* Only expand this once. */
3658 TREE_OPERAND (targ, 3) = init;
3659 TARGET_EXPR_INITIAL (targ) = NULL_TREE;
3661 else
3662 /* We should have expanded this before. */
3663 gcc_assert (DECL_SEEN_IN_BIND_EXPR_P (temp));
3665 *expr_p = temp;
3666 return GS_OK;
3669 /* Gimplification of expression trees. */
3671 /* Gimplify an expression which appears at statement context; usually, this
3672 means replacing it with a suitably gimple STATEMENT_LIST. */
3674 void
3675 gimplify_stmt (tree *stmt_p)
3677 gimplify_expr (stmt_p, NULL, NULL, is_gimple_stmt, fb_none);
3680 /* Similarly, but force the result to be a STATEMENT_LIST. */
3682 void
3683 gimplify_to_stmt_list (tree *stmt_p)
3685 gimplify_stmt (stmt_p);
3686 if (!*stmt_p)
3687 *stmt_p = alloc_stmt_list ();
3688 else if (TREE_CODE (*stmt_p) != STATEMENT_LIST)
3690 tree t = *stmt_p;
3691 *stmt_p = alloc_stmt_list ();
3692 append_to_statement_list (t, stmt_p);
3697 /* Gimplifies the expression tree pointed by EXPR_P. Return 0 if
3698 gimplification failed.
3700 PRE_P points to the list where side effects that must happen before
3701 EXPR should be stored.
3703 POST_P points to the list where side effects that must happen after
3704 EXPR should be stored, or NULL if there is no suitable list. In
3705 that case, we copy the result to a temporary, emit the
3706 post-effects, and then return the temporary.
3708 GIMPLE_TEST_F points to a function that takes a tree T and
3709 returns nonzero if T is in the GIMPLE form requested by the
3710 caller. The GIMPLE predicates are in tree-gimple.c.
3712 This test is used twice. Before gimplification, the test is
3713 invoked to determine whether *EXPR_P is already gimple enough. If
3714 that fails, *EXPR_P is gimplified according to its code and
3715 GIMPLE_TEST_F is called again. If the test still fails, then a new
3716 temporary variable is created and assigned the value of the
3717 gimplified expression.
3719 FALLBACK tells the function what sort of a temporary we want. If the 1
3720 bit is set, an rvalue is OK. If the 2 bit is set, an lvalue is OK.
3721 If both are set, either is OK, but an lvalue is preferable.
3723 The return value is either GS_ERROR or GS_ALL_DONE, since this function
3724 iterates until solution. */
3726 enum gimplify_status
3727 gimplify_expr (tree *expr_p, tree *pre_p, tree *post_p,
3728 bool (* gimple_test_f) (tree), fallback_t fallback)
3730 tree tmp;
3731 tree internal_pre = NULL_TREE;
3732 tree internal_post = NULL_TREE;
3733 tree save_expr;
3734 int is_statement = (pre_p == NULL);
3735 location_t saved_location;
3736 enum gimplify_status ret;
3738 save_expr = *expr_p;
3739 if (save_expr == NULL_TREE)
3740 return GS_ALL_DONE;
3742 /* We used to check the predicate here and return immediately if it
3743 succeeds. This is wrong; the design is for gimplification to be
3744 idempotent, and for the predicates to only test for valid forms, not
3745 whether they are fully simplified. */
3747 /* Set up our internal queues if needed. */
3748 if (pre_p == NULL)
3749 pre_p = &internal_pre;
3750 if (post_p == NULL)
3751 post_p = &internal_post;
3753 saved_location = input_location;
3754 if (save_expr != error_mark_node
3755 && EXPR_HAS_LOCATION (*expr_p))
3756 input_location = EXPR_LOCATION (*expr_p);
3758 /* Loop over the specific gimplifiers until the toplevel node
3759 remains the same. */
3762 /* Strip away as many useless type conversions as possible
3763 at the toplevel. */
3764 STRIP_USELESS_TYPE_CONVERSION (*expr_p);
3766 /* Remember the expr. */
3767 save_expr = *expr_p;
3769 /* Die, die, die, my darling. */
3770 if (save_expr == error_mark_node
3771 || (TREE_TYPE (save_expr)
3772 && TREE_TYPE (save_expr) == error_mark_node))
3774 ret = GS_ERROR;
3775 break;
3778 /* Do any language-specific gimplification. */
3779 ret = lang_hooks.gimplify_expr (expr_p, pre_p, post_p);
3780 if (ret == GS_OK)
3782 if (*expr_p == NULL_TREE)
3783 break;
3784 if (*expr_p != save_expr)
3785 continue;
3787 else if (ret != GS_UNHANDLED)
3788 break;
3790 ret = GS_OK;
3791 switch (TREE_CODE (*expr_p))
3793 /* First deal with the special cases. */
3795 case POSTINCREMENT_EXPR:
3796 case POSTDECREMENT_EXPR:
3797 case PREINCREMENT_EXPR:
3798 case PREDECREMENT_EXPR:
3799 ret = gimplify_self_mod_expr (expr_p, pre_p, post_p,
3800 fallback != fb_none);
3801 break;
3803 case ARRAY_REF:
3804 case ARRAY_RANGE_REF:
3805 case REALPART_EXPR:
3806 case IMAGPART_EXPR:
3807 case COMPONENT_REF:
3808 case VIEW_CONVERT_EXPR:
3809 ret = gimplify_compound_lval (expr_p, pre_p, post_p,
3810 fallback ? fallback : fb_rvalue);
3811 break;
3813 case COND_EXPR:
3814 ret = gimplify_cond_expr (expr_p, pre_p, post_p, NULL_TREE,
3815 fallback);
3816 /* C99 code may assign to an array in a structure value of a
3817 conditional expression, and this has undefined behavior
3818 only on execution, so create a temporary if an lvalue is
3819 required. */
3820 if (fallback == fb_lvalue)
3822 *expr_p = get_initialized_tmp_var (*expr_p, pre_p, post_p);
3823 lang_hooks.mark_addressable (*expr_p);
3825 break;
3827 case CALL_EXPR:
3828 ret = gimplify_call_expr (expr_p, pre_p, fallback != fb_none);
3829 /* C99 code may assign to an array in a structure returned
3830 from a function, and this has undefined behavior only on
3831 execution, so create a temporary if an lvalue is
3832 required. */
3833 if (fallback == fb_lvalue)
3835 *expr_p = get_initialized_tmp_var (*expr_p, pre_p, post_p);
3836 lang_hooks.mark_addressable (*expr_p);
3838 break;
3840 case TREE_LIST:
3841 gcc_unreachable ();
3843 case COMPOUND_EXPR:
3844 ret = gimplify_compound_expr (expr_p, pre_p, fallback != fb_none);
3845 break;
3847 case MODIFY_EXPR:
3848 case INIT_EXPR:
3849 ret = gimplify_modify_expr (expr_p, pre_p, post_p,
3850 fallback != fb_none);
3851 break;
3853 case TRUTH_ANDIF_EXPR:
3854 case TRUTH_ORIF_EXPR:
3855 ret = gimplify_boolean_expr (expr_p);
3856 break;
3858 case TRUTH_NOT_EXPR:
3859 TREE_OPERAND (*expr_p, 0)
3860 = gimple_boolify (TREE_OPERAND (*expr_p, 0));
3861 ret = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p, post_p,
3862 is_gimple_val, fb_rvalue);
3863 recalculate_side_effects (*expr_p);
3864 break;
3866 case ADDR_EXPR:
3867 ret = gimplify_addr_expr (expr_p, pre_p, post_p);
3868 break;
3870 case VA_ARG_EXPR:
3871 ret = gimplify_va_arg_expr (expr_p, pre_p, post_p);
3872 break;
3874 case CONVERT_EXPR:
3875 case NOP_EXPR:
3876 if (IS_EMPTY_STMT (*expr_p))
3878 ret = GS_ALL_DONE;
3879 break;
3882 if (VOID_TYPE_P (TREE_TYPE (*expr_p))
3883 || fallback == fb_none)
3885 /* Just strip a conversion to void (or in void context) and
3886 try again. */
3887 *expr_p = TREE_OPERAND (*expr_p, 0);
3888 break;
3891 ret = gimplify_conversion (expr_p);
3892 if (ret == GS_ERROR)
3893 break;
3894 if (*expr_p != save_expr)
3895 break;
3896 /* FALLTHRU */
3898 case FIX_TRUNC_EXPR:
3899 case FIX_CEIL_EXPR:
3900 case FIX_FLOOR_EXPR:
3901 case FIX_ROUND_EXPR:
3902 /* unary_expr: ... | '(' cast ')' val | ... */
3903 ret = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p, post_p,
3904 is_gimple_val, fb_rvalue);
3905 recalculate_side_effects (*expr_p);
3906 break;
3908 case INDIRECT_REF:
3909 *expr_p = fold_indirect_ref (*expr_p);
3910 if (*expr_p != save_expr)
3911 break;
3912 /* else fall through. */
3913 case ALIGN_INDIRECT_REF:
3914 case MISALIGNED_INDIRECT_REF:
3915 ret = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p, post_p,
3916 is_gimple_reg, fb_rvalue);
3917 recalculate_side_effects (*expr_p);
3918 break;
3920 /* Constants need not be gimplified. */
3921 case INTEGER_CST:
3922 case REAL_CST:
3923 case STRING_CST:
3924 case COMPLEX_CST:
3925 case VECTOR_CST:
3926 ret = GS_ALL_DONE;
3927 break;
3929 case CONST_DECL:
3930 /* If we require an lvalue, such as for ADDR_EXPR, retain the
3931 CONST_DECL node. Otherwise the decl is replaceable by its
3932 value. */
3933 /* ??? Should be == fb_lvalue, but ADDR_EXPR passes fb_either. */
3934 if (fallback & fb_lvalue)
3935 ret = GS_ALL_DONE;
3936 else
3937 *expr_p = DECL_INITIAL (*expr_p);
3938 break;
3940 case DECL_EXPR:
3941 ret = gimplify_decl_expr (expr_p);
3942 break;
3944 case EXC_PTR_EXPR:
3945 /* FIXME make this a decl. */
3946 ret = GS_ALL_DONE;
3947 break;
3949 case BIND_EXPR:
3950 ret = gimplify_bind_expr (expr_p, NULL, pre_p);
3951 break;
3953 case LOOP_EXPR:
3954 ret = gimplify_loop_expr (expr_p, pre_p);
3955 break;
3957 case SWITCH_EXPR:
3958 ret = gimplify_switch_expr (expr_p, pre_p);
3959 break;
3961 case EXIT_EXPR:
3962 ret = gimplify_exit_expr (expr_p);
3963 break;
3965 case GOTO_EXPR:
3966 /* If the target is not LABEL, then it is a computed jump
3967 and the target needs to be gimplified. */
3968 if (TREE_CODE (GOTO_DESTINATION (*expr_p)) != LABEL_DECL)
3969 ret = gimplify_expr (&GOTO_DESTINATION (*expr_p), pre_p,
3970 NULL, is_gimple_val, fb_rvalue);
3971 break;
3973 case LABEL_EXPR:
3974 ret = GS_ALL_DONE;
3975 gcc_assert (decl_function_context (LABEL_EXPR_LABEL (*expr_p))
3976 == current_function_decl);
3977 break;
3979 case CASE_LABEL_EXPR:
3980 ret = gimplify_case_label_expr (expr_p);
3981 break;
3983 case RETURN_EXPR:
3984 ret = gimplify_return_expr (*expr_p, pre_p);
3985 break;
3987 case CONSTRUCTOR:
3988 /* Don't reduce this in place; let gimplify_init_constructor work its
3989 magic. Buf if we're just elaborating this for side effects, just
3990 gimplify any element that has side-effects. */
3991 if (fallback == fb_none)
3993 for (tmp = CONSTRUCTOR_ELTS (*expr_p); tmp;
3994 tmp = TREE_CHAIN (tmp))
3995 if (TREE_SIDE_EFFECTS (TREE_VALUE (tmp)))
3996 gimplify_expr (&TREE_VALUE (tmp), pre_p, post_p,
3997 gimple_test_f, fallback);
3999 *expr_p = NULL_TREE;
4002 ret = GS_ALL_DONE;
4003 break;
4005 /* The following are special cases that are not handled by the
4006 original GIMPLE grammar. */
4008 /* SAVE_EXPR nodes are converted into a GIMPLE identifier and
4009 eliminated. */
4010 case SAVE_EXPR:
4011 ret = gimplify_save_expr (expr_p, pre_p, post_p);
4012 break;
4014 case BIT_FIELD_REF:
4016 enum gimplify_status r0, r1, r2;
4018 r0 = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p, post_p,
4019 is_gimple_lvalue, fb_either);
4020 r1 = gimplify_expr (&TREE_OPERAND (*expr_p, 1), pre_p, post_p,
4021 is_gimple_val, fb_rvalue);
4022 r2 = gimplify_expr (&TREE_OPERAND (*expr_p, 2), pre_p, post_p,
4023 is_gimple_val, fb_rvalue);
4024 recalculate_side_effects (*expr_p);
4026 ret = MIN (r0, MIN (r1, r2));
4028 break;
4030 case NON_LVALUE_EXPR:
4031 /* This should have been stripped above. */
4032 gcc_unreachable ();
4034 case ASM_EXPR:
4035 ret = gimplify_asm_expr (expr_p, pre_p, post_p);
4036 break;
4038 case TRY_FINALLY_EXPR:
4039 case TRY_CATCH_EXPR:
4040 gimplify_to_stmt_list (&TREE_OPERAND (*expr_p, 0));
4041 gimplify_to_stmt_list (&TREE_OPERAND (*expr_p, 1));
4042 ret = GS_ALL_DONE;
4043 break;
4045 case CLEANUP_POINT_EXPR:
4046 ret = gimplify_cleanup_point_expr (expr_p, pre_p);
4047 break;
4049 case TARGET_EXPR:
4050 ret = gimplify_target_expr (expr_p, pre_p, post_p);
4051 break;
4053 case CATCH_EXPR:
4054 gimplify_to_stmt_list (&CATCH_BODY (*expr_p));
4055 ret = GS_ALL_DONE;
4056 break;
4058 case EH_FILTER_EXPR:
4059 gimplify_to_stmt_list (&EH_FILTER_FAILURE (*expr_p));
4060 ret = GS_ALL_DONE;
4061 break;
4063 case OBJ_TYPE_REF:
4065 enum gimplify_status r0, r1;
4066 r0 = gimplify_expr (&OBJ_TYPE_REF_OBJECT (*expr_p), pre_p, post_p,
4067 is_gimple_val, fb_rvalue);
4068 r1 = gimplify_expr (&OBJ_TYPE_REF_EXPR (*expr_p), pre_p, post_p,
4069 is_gimple_val, fb_rvalue);
4070 ret = MIN (r0, r1);
4072 break;
4074 case LABEL_DECL:
4075 /* We get here when taking the address of a label. We mark
4076 the label as "forced"; meaning it can never be removed and
4077 it is a potential target for any computed goto. */
4078 FORCED_LABEL (*expr_p) = 1;
4079 ret = GS_ALL_DONE;
4080 break;
4082 case STATEMENT_LIST:
4083 ret = gimplify_statement_list (expr_p);
4084 break;
4086 case WITH_SIZE_EXPR:
4088 gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p,
4089 post_p == &internal_post ? NULL : post_p,
4090 gimple_test_f, fallback);
4091 gimplify_expr (&TREE_OPERAND (*expr_p, 1), pre_p, post_p,
4092 is_gimple_val, fb_rvalue);
4094 break;
4096 case VAR_DECL:
4097 /* ??? If this is a local variable, and it has not been seen in any
4098 outer BIND_EXPR, then it's probably the result of a duplicate
4099 declaration, for which we've already issued an error. It would
4100 be really nice if the front end wouldn't leak these at all.
4101 Currently the only known culprit is C++ destructors, as seen
4102 in g++.old-deja/g++.jason/binding.C. */
4103 tmp = *expr_p;
4104 if (!TREE_STATIC (tmp) && !DECL_EXTERNAL (tmp)
4105 && decl_function_context (tmp) == current_function_decl
4106 && !DECL_SEEN_IN_BIND_EXPR_P (tmp))
4108 gcc_assert (errorcount || sorrycount);
4109 ret = GS_ERROR;
4110 break;
4112 /* FALLTHRU */
4114 case PARM_DECL:
4115 tmp = *expr_p;
4117 /* If this is a local variable sized decl, it must be accessed
4118 indirectly. Perform that substitution. */
4119 if (DECL_VALUE_EXPR (tmp))
4121 *expr_p = unshare_expr (DECL_VALUE_EXPR (tmp));
4122 ret = GS_OK;
4123 break;
4126 ret = GS_ALL_DONE;
4127 break;
4129 case SSA_NAME:
4130 /* Allow callbacks into the gimplifier during optimization. */
4131 ret = GS_ALL_DONE;
4132 break;
4134 default:
4135 switch (TREE_CODE_CLASS (TREE_CODE (*expr_p)))
4137 case tcc_comparison:
4138 /* If this is a comparison of objects of aggregate type,
4139 handle it specially (by converting to a call to
4140 memcmp). It would be nice to only have to do this
4141 for variable-sized objects, but then we'd have to
4142 allow the same nest of reference nodes we allow for
4143 MODIFY_EXPR and that's too complex. */
4144 if (!AGGREGATE_TYPE_P (TREE_TYPE (TREE_OPERAND (*expr_p, 1))))
4145 goto expr_2;
4146 ret = gimplify_variable_sized_compare (expr_p);
4147 break;
4149 /* If *EXPR_P does not need to be special-cased, handle it
4150 according to its class. */
4151 case tcc_unary:
4152 ret = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p,
4153 post_p, is_gimple_val, fb_rvalue);
4154 break;
4156 case tcc_binary:
4157 expr_2:
4159 enum gimplify_status r0, r1;
4161 r0 = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p,
4162 post_p, is_gimple_val, fb_rvalue);
4163 r1 = gimplify_expr (&TREE_OPERAND (*expr_p, 1), pre_p,
4164 post_p, is_gimple_val, fb_rvalue);
4166 ret = MIN (r0, r1);
4167 break;
4170 case tcc_declaration:
4171 case tcc_constant:
4172 ret = GS_ALL_DONE;
4173 goto dont_recalculate;
4175 default:
4176 gcc_assert (TREE_CODE (*expr_p) == TRUTH_AND_EXPR
4177 || TREE_CODE (*expr_p) == TRUTH_OR_EXPR
4178 || TREE_CODE (*expr_p) == TRUTH_XOR_EXPR);
4179 goto expr_2;
4182 recalculate_side_effects (*expr_p);
4183 dont_recalculate:
4184 break;
4187 /* If we replaced *expr_p, gimplify again. */
4188 if (ret == GS_OK && (*expr_p == NULL || *expr_p == save_expr))
4189 ret = GS_ALL_DONE;
4191 while (ret == GS_OK);
4193 /* If we encountered an error_mark somewhere nested inside, either
4194 stub out the statement or propagate the error back out. */
4195 if (ret == GS_ERROR)
4197 if (is_statement)
4198 *expr_p = NULL;
4199 goto out;
4202 /* This was only valid as a return value from the langhook, which
4203 we handled. Make sure it doesn't escape from any other context. */
4204 gcc_assert (ret != GS_UNHANDLED);
4206 if (fallback == fb_none && *expr_p && !is_gimple_stmt (*expr_p))
4208 /* We aren't looking for a value, and we don't have a valid
4209 statement. If it doesn't have side-effects, throw it away. */
4210 if (!TREE_SIDE_EFFECTS (*expr_p))
4211 *expr_p = NULL;
4212 else if (!TREE_THIS_VOLATILE (*expr_p))
4214 /* This is probably a _REF that contains something nested that
4215 has side effects. Recurse through the operands to find it. */
4216 enum tree_code code = TREE_CODE (*expr_p);
4218 switch (code)
4220 case COMPONENT_REF:
4221 case REALPART_EXPR: case IMAGPART_EXPR:
4222 gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p, post_p,
4223 gimple_test_f, fallback);
4224 break;
4226 case ARRAY_REF: case ARRAY_RANGE_REF:
4227 gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p, post_p,
4228 gimple_test_f, fallback);
4229 gimplify_expr (&TREE_OPERAND (*expr_p, 1), pre_p, post_p,
4230 gimple_test_f, fallback);
4231 break;
4233 default:
4234 /* Anything else with side-effects must be converted to
4235 a valid statement before we get here. */
4236 gcc_unreachable ();
4239 *expr_p = NULL;
4241 else if (COMPLETE_TYPE_P (TREE_TYPE (*expr_p)))
4243 /* Historically, the compiler has treated a bare
4244 reference to a volatile lvalue as forcing a load. */
4245 tree tmp = create_tmp_var (TREE_TYPE (*expr_p), "vol");
4246 *expr_p = build (MODIFY_EXPR, TREE_TYPE (tmp), tmp, *expr_p);
4248 else
4249 /* We can't do anything useful with a volatile reference to
4250 incomplete type, so just throw it away. */
4251 *expr_p = NULL;
4254 /* If we are gimplifying at the statement level, we're done. Tack
4255 everything together and replace the original statement with the
4256 gimplified form. */
4257 if (fallback == fb_none || is_statement)
4259 if (internal_pre || internal_post)
4261 append_to_statement_list (*expr_p, &internal_pre);
4262 append_to_statement_list (internal_post, &internal_pre);
4263 annotate_all_with_locus (&internal_pre, input_location);
4264 *expr_p = internal_pre;
4266 else if (!*expr_p)
4268 else if (TREE_CODE (*expr_p) == STATEMENT_LIST)
4269 annotate_all_with_locus (expr_p, input_location);
4270 else
4271 annotate_one_with_locus (*expr_p, input_location);
4272 goto out;
4275 /* Otherwise we're gimplifying a subexpression, so the resulting value is
4276 interesting. */
4278 /* If it's sufficiently simple already, we're done. Unless we are
4279 handling some post-effects internally; if that's the case, we need to
4280 copy into a temp before adding the post-effects to the tree. */
4281 if (!internal_post && (*gimple_test_f) (*expr_p))
4282 goto out;
4284 /* Otherwise, we need to create a new temporary for the gimplified
4285 expression. */
4287 /* We can't return an lvalue if we have an internal postqueue. The
4288 object the lvalue refers to would (probably) be modified by the
4289 postqueue; we need to copy the value out first, which means an
4290 rvalue. */
4291 if ((fallback & fb_lvalue) && !internal_post
4292 && is_gimple_addressable (*expr_p))
4294 /* An lvalue will do. Take the address of the expression, store it
4295 in a temporary, and replace the expression with an INDIRECT_REF of
4296 that temporary. */
4297 tmp = build_fold_addr_expr (*expr_p);
4298 gimplify_expr (&tmp, pre_p, post_p, is_gimple_reg, fb_rvalue);
4299 *expr_p = build1 (INDIRECT_REF, TREE_TYPE (TREE_TYPE (tmp)), tmp);
4301 else if ((fallback & fb_rvalue) && is_gimple_formal_tmp_rhs (*expr_p))
4303 gcc_assert (!VOID_TYPE_P (TREE_TYPE (*expr_p)));
4305 /* An rvalue will do. Assign the gimplified expression into a new
4306 temporary TMP and replace the original expression with TMP. */
4308 if (internal_post || (fallback & fb_lvalue))
4309 /* The postqueue might change the value of the expression between
4310 the initialization and use of the temporary, so we can't use a
4311 formal temp. FIXME do we care? */
4312 *expr_p = get_initialized_tmp_var (*expr_p, pre_p, post_p);
4313 else
4314 *expr_p = get_formal_tmp_var (*expr_p, pre_p);
4316 if (TREE_CODE (*expr_p) != SSA_NAME)
4317 DECL_GIMPLE_FORMAL_TEMP_P (*expr_p) = 1;
4319 else
4321 #ifdef ENABLE_CHECKING
4322 if (!(fallback & fb_mayfail))
4324 fprintf (stderr, "gimplification failed:\n");
4325 print_generic_expr (stderr, *expr_p, 0);
4326 debug_tree (*expr_p);
4327 internal_error ("gimplification failed");
4329 #endif
4330 gcc_assert (fallback & fb_mayfail);
4331 /* If this is an asm statement, and the user asked for the
4332 impossible, don't die. Fail and let gimplify_asm_expr
4333 issue an error. */
4334 ret = GS_ERROR;
4335 goto out;
4338 /* Make sure the temporary matches our predicate. */
4339 gcc_assert ((*gimple_test_f) (*expr_p));
4341 if (internal_post)
4343 annotate_all_with_locus (&internal_post, input_location);
4344 append_to_statement_list (internal_post, pre_p);
4347 out:
4348 input_location = saved_location;
4349 return ret;
4352 /* Look through TYPE for variable-sized objects and gimplify each such
4353 size that we find. Add to LIST_P any statements generated. */
4355 void
4356 gimplify_type_sizes (tree type, tree *list_p)
4358 tree field, t;
4360 /* Note that we do not check for TYPE_SIZES_GIMPLIFIED already set because
4361 that's not supposed to happen on types where gimplification does anything.
4362 We should assert that it isn't set, but we can indeed be called multiple
4363 times on pointers. Unfortunately, this includes fat pointers which we
4364 can't easily test for. We could pass TYPE down to gimplify_one_sizepos
4365 and test there, but it doesn't seem worth it. */
4367 /* We first do the main variant, then copy into any other variants. */
4368 type = TYPE_MAIN_VARIANT (type);
4370 switch (TREE_CODE (type))
4372 case ERROR_MARK:
4373 return;
4375 case INTEGER_TYPE:
4376 case ENUMERAL_TYPE:
4377 case BOOLEAN_TYPE:
4378 case CHAR_TYPE:
4379 case REAL_TYPE:
4380 gimplify_one_sizepos (&TYPE_MIN_VALUE (type), list_p);
4381 gimplify_one_sizepos (&TYPE_MAX_VALUE (type), list_p);
4383 for (t = TYPE_NEXT_VARIANT (type); t; t = TYPE_NEXT_VARIANT (t))
4385 TYPE_MIN_VALUE (t) = TYPE_MIN_VALUE (type);
4386 TYPE_MAX_VALUE (t) = TYPE_MAX_VALUE (type);
4387 TYPE_SIZES_GIMPLIFIED (t) = 1;
4389 break;
4391 case ARRAY_TYPE:
4392 /* These types may not have declarations, so handle them here. */
4393 if (!TYPE_SIZES_GIMPLIFIED (TREE_TYPE (type)))
4394 gimplify_type_sizes (TREE_TYPE (type), list_p);
4396 if (!TYPE_SIZES_GIMPLIFIED (TYPE_DOMAIN (type)))
4397 gimplify_type_sizes (TYPE_DOMAIN (type), list_p);
4398 break;
4400 case RECORD_TYPE:
4401 case UNION_TYPE:
4402 case QUAL_UNION_TYPE:
4403 for (field = TYPE_FIELDS (type); field; field = TREE_CHAIN (field))
4404 if (TREE_CODE (field) == FIELD_DECL)
4405 gimplify_one_sizepos (&DECL_FIELD_OFFSET (field), list_p);
4406 break;
4408 default:
4409 break;
4412 gimplify_one_sizepos (&TYPE_SIZE (type), list_p);
4413 gimplify_one_sizepos (&TYPE_SIZE_UNIT (type), list_p);
4415 for (t = TYPE_NEXT_VARIANT (type); t; t = TYPE_NEXT_VARIANT (t))
4417 TYPE_SIZE (t) = TYPE_SIZE (type);
4418 TYPE_SIZE_UNIT (t) = TYPE_SIZE_UNIT (type);
4419 TYPE_SIZES_GIMPLIFIED (t) = 1;
4422 TYPE_SIZES_GIMPLIFIED (type) = 1;
4425 /* A subroutine of gimplify_type_sizes to make sure that *EXPR_P,
4426 a size or position, has had all of its SAVE_EXPRs evaluated.
4427 We add any required statements to STMT_P. */
4429 void
4430 gimplify_one_sizepos (tree *expr_p, tree *stmt_p)
4432 /* We don't do anything if the value isn't there, is constant, or contains
4433 A PLACEHOLDER_EXPR. We also don't want to do anything if it's already
4434 a VAR_DECL. If it's a VAR_DECL from another function, the gimplifier
4435 will want to replace it with a new variable, but that will cause problems
4436 if this type is from outside the function. It's OK to have that here. */
4437 if (*expr_p == NULL_TREE || TREE_CONSTANT (*expr_p)
4438 || TREE_CODE (*expr_p) == VAR_DECL
4439 || CONTAINS_PLACEHOLDER_P (*expr_p))
4440 return;
4442 *expr_p = unshare_expr (*expr_p);
4443 gimplify_expr (expr_p, stmt_p, NULL, is_gimple_val, fb_rvalue);
4446 #ifdef ENABLE_CHECKING
4447 /* Compare types A and B for a "close enough" match. */
4449 static bool
4450 cpt_same_type (tree a, tree b)
4452 if (lang_hooks.types_compatible_p (a, b))
4453 return true;
4455 /* ??? The C++ FE decomposes METHOD_TYPES to FUNCTION_TYPES and doesn't
4456 link them together. This routine is intended to catch type errors
4457 that will affect the optimizers, and the optimizers don't add new
4458 dereferences of function pointers, so ignore it. */
4459 if ((TREE_CODE (a) == FUNCTION_TYPE || TREE_CODE (a) == METHOD_TYPE)
4460 && (TREE_CODE (b) == FUNCTION_TYPE || TREE_CODE (b) == METHOD_TYPE))
4461 return true;
4463 /* ??? The C FE pushes type qualifiers after the fact into the type of
4464 the element from the type of the array. See build_unary_op's handling
4465 of ADDR_EXPR. This seems wrong -- if we were going to do this, we
4466 should have done it when creating the variable in the first place.
4467 Alternately, why aren't the two array types made variants? */
4468 if (TREE_CODE (a) == ARRAY_TYPE && TREE_CODE (b) == ARRAY_TYPE)
4469 return cpt_same_type (TREE_TYPE (a), TREE_TYPE (b));
4471 /* And because of those, we have to recurse down through pointers. */
4472 if (POINTER_TYPE_P (a) && POINTER_TYPE_P (b))
4473 return cpt_same_type (TREE_TYPE (a), TREE_TYPE (b));
4475 return false;
4478 /* Check for some cases of the front end missing cast expressions.
4479 The type of a dereference should correspond to the pointer type;
4480 similarly the type of an address should match its object. */
4482 static tree
4483 check_pointer_types_r (tree *tp, int *walk_subtrees ATTRIBUTE_UNUSED,
4484 void *data ATTRIBUTE_UNUSED)
4486 tree t = *tp;
4487 tree ptype, otype, dtype;
4489 switch (TREE_CODE (t))
4491 case INDIRECT_REF:
4492 case ARRAY_REF:
4493 otype = TREE_TYPE (t);
4494 ptype = TREE_TYPE (TREE_OPERAND (t, 0));
4495 dtype = TREE_TYPE (ptype);
4496 gcc_assert (cpt_same_type (otype, dtype));
4497 break;
4499 case ADDR_EXPR:
4500 ptype = TREE_TYPE (t);
4501 otype = TREE_TYPE (TREE_OPERAND (t, 0));
4502 dtype = TREE_TYPE (ptype);
4503 if (!cpt_same_type (otype, dtype))
4505 /* &array is allowed to produce a pointer to the element, rather than
4506 a pointer to the array type. We must allow this in order to
4507 properly represent assigning the address of an array in C into
4508 pointer to the element type. */
4509 gcc_assert (TREE_CODE (otype) == ARRAY_TYPE
4510 && POINTER_TYPE_P (ptype)
4511 && cpt_same_type (TREE_TYPE (otype), dtype));
4512 break;
4514 break;
4516 default:
4517 return NULL_TREE;
4521 return NULL_TREE;
4523 #endif
4525 /* Gimplify the body of statements pointed by BODY_P. FNDECL is the
4526 function decl containing BODY. */
4528 void
4529 gimplify_body (tree *body_p, tree fndecl, bool do_parms)
4531 location_t saved_location = input_location;
4532 tree body, parm_stmts;
4534 timevar_push (TV_TREE_GIMPLIFY);
4535 push_gimplify_context ();
4537 /* Unshare most shared trees in the body and in that of any nested functions.
4538 It would seem we don't have to do this for nested functions because
4539 they are supposed to be output and then the outer function gimplified
4540 first, but the g++ front end doesn't always do it that way. */
4541 unshare_body (body_p, fndecl);
4542 unvisit_body (body_p, fndecl);
4544 /* Make sure input_location isn't set to something wierd. */
4545 input_location = DECL_SOURCE_LOCATION (fndecl);
4547 /* Resolve callee-copies. This has to be done before processing
4548 the body so that DECL_VALUE_EXPR gets processed correctly. */
4549 parm_stmts = do_parms ? gimplify_parameters () : NULL;
4551 /* Gimplify the function's body. */
4552 gimplify_stmt (body_p);
4553 body = *body_p;
4555 if (!body)
4556 body = alloc_stmt_list ();
4557 else if (TREE_CODE (body) == STATEMENT_LIST)
4559 tree t = expr_only (*body_p);
4560 if (t)
4561 body = t;
4564 /* If there isn't an outer BIND_EXPR, add one. */
4565 if (TREE_CODE (body) != BIND_EXPR)
4567 tree b = build (BIND_EXPR, void_type_node, NULL_TREE,
4568 NULL_TREE, NULL_TREE);
4569 TREE_SIDE_EFFECTS (b) = 1;
4570 append_to_statement_list_force (body, &BIND_EXPR_BODY (b));
4571 body = b;
4574 /* If we had callee-copies statements, insert them at the beginning
4575 of the function. */
4576 if (parm_stmts)
4578 append_to_statement_list_force (BIND_EXPR_BODY (body), &parm_stmts);
4579 BIND_EXPR_BODY (body) = parm_stmts;
4582 /* Unshare again, in case gimplification was sloppy. */
4583 unshare_all_trees (body);
4585 *body_p = body;
4587 pop_gimplify_context (body);
4589 #ifdef ENABLE_CHECKING
4590 walk_tree (body_p, check_pointer_types_r, NULL, NULL);
4591 #endif
4593 timevar_pop (TV_TREE_GIMPLIFY);
4594 input_location = saved_location;
4597 /* Entry point to the gimplification pass. FNDECL is the FUNCTION_DECL
4598 node for the function we want to gimplify. */
4600 void
4601 gimplify_function_tree (tree fndecl)
4603 tree oldfn;
4605 oldfn = current_function_decl;
4606 current_function_decl = fndecl;
4607 cfun = DECL_STRUCT_FUNCTION (fndecl);
4608 if (cfun == NULL)
4609 allocate_struct_function (fndecl);
4611 gimplify_body (&DECL_SAVED_TREE (fndecl), fndecl, true);
4613 /* If we're instrumenting function entry/exit, then prepend the call to
4614 the entry hook and wrap the whole function in a TRY_FINALLY_EXPR to
4615 catch the exit hook. */
4616 /* ??? Add some way to ignore exceptions for this TFE. */
4617 if (flag_instrument_function_entry_exit
4618 && ! DECL_NO_INSTRUMENT_FUNCTION_ENTRY_EXIT (fndecl))
4620 tree tf, x, bind;
4622 tf = build (TRY_FINALLY_EXPR, void_type_node, NULL, NULL);
4623 TREE_SIDE_EFFECTS (tf) = 1;
4624 x = DECL_SAVED_TREE (fndecl);
4625 append_to_statement_list (x, &TREE_OPERAND (tf, 0));
4626 x = implicit_built_in_decls[BUILT_IN_PROFILE_FUNC_EXIT];
4627 x = build_function_call_expr (x, NULL);
4628 append_to_statement_list (x, &TREE_OPERAND (tf, 1));
4630 bind = build (BIND_EXPR, void_type_node, NULL, NULL, NULL);
4631 TREE_SIDE_EFFECTS (bind) = 1;
4632 x = implicit_built_in_decls[BUILT_IN_PROFILE_FUNC_ENTER];
4633 x = build_function_call_expr (x, NULL);
4634 append_to_statement_list (x, &BIND_EXPR_BODY (bind));
4635 append_to_statement_list (tf, &BIND_EXPR_BODY (bind));
4637 DECL_SAVED_TREE (fndecl) = bind;
4640 current_function_decl = oldfn;
4641 cfun = oldfn ? DECL_STRUCT_FUNCTION (oldfn) : NULL;
4645 /* Expands EXPR to list of gimple statements STMTS. If SIMPLE is true,
4646 force the result to be either ssa_name or an invariant, otherwise
4647 just force it to be a rhs expression. If VAR is not NULL, make the
4648 base variable of the final destination be VAR if suitable. */
4650 tree
4651 force_gimple_operand (tree expr, tree *stmts, bool simple, tree var)
4653 tree t;
4654 enum gimplify_status ret;
4655 gimple_predicate gimple_test_f;
4657 *stmts = NULL_TREE;
4659 if (is_gimple_val (expr))
4660 return expr;
4662 gimple_test_f = simple ? is_gimple_val : is_gimple_reg_rhs;
4664 push_gimplify_context ();
4665 gimplify_ctxp->into_ssa = in_ssa_p;
4667 if (var)
4668 expr = build (MODIFY_EXPR, TREE_TYPE (var), var, expr);
4670 ret = gimplify_expr (&expr, stmts, NULL,
4671 gimple_test_f, fb_rvalue);
4672 gcc_assert (ret != GS_ERROR);
4674 if (referenced_vars)
4676 for (t = gimplify_ctxp->temps; t ; t = TREE_CHAIN (t))
4677 add_referenced_tmp_var (t);
4680 pop_gimplify_context (NULL);
4682 return expr;
4685 /* Invokes force_gimple_operand for EXPR with parameters SIMPLE_P and VAR. If
4686 some statements are produced, emits them before BSI. */
4688 tree
4689 force_gimple_operand_bsi (block_stmt_iterator *bsi, tree expr,
4690 bool simple_p, tree var)
4692 tree stmts;
4694 expr = force_gimple_operand (expr, &stmts, simple_p, var);
4695 if (stmts)
4696 bsi_insert_before (bsi, stmts, BSI_SAME_STMT);
4698 return expr;
4701 #include "gt-gimplify.h"