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
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
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
26 #include "coretypes.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"
50 static struct gimplify_ctx
52 tree current_bind_expr;
54 tree conditional_cleanups;
57 varray_type case_labels;
58 /* The formal temporary table. Should this be persistent? */
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
72 tree temp; /* Value */
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);
82 /* Return a hash value for a formal temporary table entry. */
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. */
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))
104 if (!operand_equal_p (t1, t2, 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));
114 /* Set up a context for the gimplifier. */
117 push_gimplify_context (void)
119 gcc_assert (!gimplify_ctxp);
121 = (struct gimplify_ctx *) xcalloc (1, sizeof (struct gimplify_ctx));
123 gimplify_ctxp->temp_htab
124 = htab_create (1000, gimple_tree_hash, gimple_tree_eq, free);
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. */
134 pop_gimplify_context (tree body)
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;
144 declare_tmp_vars (gimplify_ctxp->temps, body);
146 record_vars (gimplify_ctxp->temps);
149 if (!quiet_flag && optimize)
150 fprintf (stderr, " collisions: %f ",
151 htab_collisions (gimplify_ctxp->temp_htab));
155 htab_delete (gimplify_ctxp->temp_htab);
156 free (gimplify_ctxp);
157 gimplify_ctxp = NULL;
161 gimple_push_bind_expr (tree bind)
163 TREE_CHAIN (bind) = gimplify_ctxp->current_bind_expr;
164 gimplify_ctxp->current_bind_expr = bind;
168 gimple_pop_bind_expr (void)
170 gimplify_ctxp->current_bind_expr
171 = TREE_CHAIN (gimplify_ctxp->current_bind_expr);
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. */
184 gimple_conditional_context (void)
186 return gimplify_ctxp->conditions > 0;
189 /* Note that we've entered a COND_EXPR. */
192 gimple_push_condition (void)
194 #ifdef ENABLE_CHECKING
195 if (gimplify_ctxp->conditions == 0)
196 gcc_assert (!gimplify_ctxp->conditional_cleanups);
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. */
205 gimple_pop_condition (tree *pre_p)
207 int conds = --(gimplify_ctxp->conditions);
209 gcc_assert (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. */
220 append_to_statement_list_1 (tree t, tree *list_p)
223 tree_stmt_iterator i;
227 if (t && TREE_CODE (t) == STATEMENT_LIST)
232 *list_p = list = alloc_stmt_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. */
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. */
252 append_to_statement_list_force (tree t, tree *list_p)
255 append_to_statement_list_1 (t, list_p);
258 /* Both gimplify the statement T and append it to LIST_P. */
261 gimplify_and_add (tree t, tree *list_p)
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".) */
273 remove_suffix (char *name, int len)
277 for (i = 2; i < 8 && len > i; i++)
279 if (name[len - i] == '.')
281 name[len - i] = '\0';
287 /* Create a nameless artificial label and put it in the current function
288 context. Returns the newly created label. */
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;
301 /* Create a new temporary name with PREFIX. Returns an identifier. */
303 static GTY(()) unsigned int tmp_var_id_num;
306 create_tmp_var_name (const char *prefix)
312 char *preftmp = ASTRDUP (prefix);
314 remove_suffix (preftmp, strlen (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. */
327 create_tmp_var_raw (tree type, const char *prefix)
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,
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;
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. */
360 create_tmp_var (tree type, const char *prefix)
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);
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. */
385 STRIP_NOPS (stripped_decl);
386 if (DECL_P (stripped_decl) && DECL_NAME (stripped_decl))
387 return IDENTIFIER_POINTER (DECL_NAME (stripped_decl));
390 switch (TREE_CODE (stripped_decl))
393 return get_name (TREE_OPERAND (stripped_decl, 0));
401 /* Create a temporary with a name derived from VAL. Subroutine of
402 lookup_tmp_var; nobody else should call this function. */
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. */
414 lookup_tmp_var (tree val, bool is_formal)
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);
431 slot = htab_find_slot (gimplify_ctxp->temp_htab, (void *)&elt, INSERT);
434 elt_p = xmalloc (sizeof (*elt_p));
436 elt_p->temp = ret = create_tmp_from_val (val);
437 *slot = (void *) elt_p;
441 elt_p = (elt_t *) *slot;
447 DECL_GIMPLE_FORMAL_TEMP_P (ret) = 1;
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. */
465 internal_get_tmp_var (tree val, tree *pre_p, tree *post_p, bool is_formal)
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));
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);
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. */
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. */
509 declare_tmp_vars (tree vars, tree scope)
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;
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;
539 TREE_CHAIN (tmp) = gimplify_ctxp->temps;
540 gimplify_ctxp->temps = tmp;
545 declare_tmp_vars (tmp, DECL_SAVED_TREE (current_function_decl));
548 /* Determines whether to assign a locus to the statement STMT. */
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)
559 /* Do not annotate empty statements, since it confuses gcov. */
560 if (!TREE_SIDE_EFFECTS (stmt))
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);
574 annotate_all_with_locus (tree *stmt_p, location_t locus)
576 tree_stmt_iterator i;
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. */
600 mostly_copy_tree_r (tree *tp, int *walk_subtrees, void *data)
602 enum tree_code code = TREE_CODE (*tp);
603 /* Don't unshare types, decls, constants and SAVE_EXPR nodes. */
604 if (TREE_CODE_CLASS (code) == tcc_type
605 || TREE_CODE_CLASS (code) == tcc_declaration
606 || TREE_CODE_CLASS (code) == tcc_constant
607 || code == SAVE_EXPR || code == TARGET_EXPR
608 /* We can't do anything sensible with a BLOCK used as an expression,
609 but we also can't abort when we see it because of non-expression
610 uses. So just avert our eyes and cross our fingers. Silly Java. */
615 gcc_assert (code != BIND_EXPR);
616 copy_tree_r (tp, walk_subtrees, data);
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. */
632 copy_if_shared_r (tree *tp, int *walk_subtrees ATTRIBUTE_UNUSED,
633 void *data ATTRIBUTE_UNUSED)
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))
649 TREE_VISITED (t) = 1;
652 /* If this node has been visited already, unshare it and don't look
654 else if (TREE_VISITED (t))
656 walk_tree (tp, mostly_copy_tree_r, NULL, NULL);
660 /* Otherwise, mark the tree as visited and keep looking. */
662 TREE_VISITED (t) = 1;
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;
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
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. */
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. */
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. */
721 unshare_expr (tree expr)
723 walk_tree (&expr, mostly_copy_tree_r, NULL, NULL);
727 /* A terser interface for building a representation of an exception
731 gimple_build_eh_filter (tree body, tree allowed, tree failure)
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));
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. */
752 voidify_wrapper_expr (tree wrapper, tree temp)
754 if (!VOID_TYPE_P (TREE_TYPE (wrapper)))
756 tree *p, sub = wrapper;
759 /* Set p to point to the body of the wrapper. */
760 switch (TREE_CODE (sub))
763 /* For a BIND_EXPR, the body is operand 1. */
764 p = &BIND_EXPR_BODY (sub);
768 p = &TREE_OPERAND (sub, 0);
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);
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)
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;
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;
827 /* Prepare calls to builtins to SAVE and RESTORE the stack as well as
828 a temporary through which they communicate. */
831 build_stack_save_restore (tree *save, tree *restore)
833 tree save_call, tmp_var;
836 build_function_call_expr (implicit_built_in_decls[BUILT_IN_STACK_SAVE],
838 tmp_var = create_tmp_var (ptr_type_node, "saved_stack");
840 *save = build (MODIFY_EXPR, ptr_type_node, tmp_var, save_call);
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;
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 ();
890 append_to_statement_list (bind_expr, pre_p);
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)
914 if (VOID_TYPE_P (TREE_TYPE (TREE_TYPE (current_function_decl))))
915 result_decl = NULL_TREE;
918 result_decl = TREE_OPERAND (ret_expr, 0);
919 if (TREE_CODE (result_decl) == INDIRECT_REF)
920 /* See through a return by reference. */
921 result_decl = TREE_OPERAND (result_decl, 0);
923 gcc_assert ((TREE_CODE (ret_expr) == MODIFY_EXPR
924 || TREE_CODE (ret_expr) == INIT_EXPR)
925 && TREE_CODE (result_decl) == RESULT_DECL);
928 /* If aggregate_value_p is true, then we can return the bare RESULT_DECL.
929 Recall that aggregate_value_p is FALSE for any aggregate type that is
930 returned in registers. If we're returning values in registers, then
931 we don't want to extend the lifetime of the RESULT_DECL, particularly
932 across another call. In addition, for those aggregates for which
933 hard_function_value generates a PARALLEL, we'll abort during normal
934 expansion of structure assignments; there's special code in expand_return
935 to handle this case that does not exist in expand_expr. */
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;
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)
966 ret_expr = build (MODIFY_EXPR, TREE_TYPE (result), result_decl, result);
967 TREE_OPERAND (stmt, 0) = ret_expr;
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)
979 tree decl = DECL_EXPR_DECL (stmt);
983 if (TREE_TYPE (decl) == error_mark_node)
986 if ((TREE_CODE (decl) == TYPE_DECL
987 || TREE_CODE (decl) == VAR_DECL)
988 && !TYPE_SIZES_GIMPLIFIED (TREE_TYPE (decl)))
989 gimplify_type_sizes (TREE_TYPE (decl), stmt_p);
991 if (TREE_CODE (decl) == VAR_DECL && !DECL_EXTERNAL (decl))
993 tree init = DECL_INITIAL (decl);
995 if (!TREE_CONSTANT (DECL_SIZE (decl)))
997 /* This is a variable-sized decl. Simplify its size and mark it
998 for deferred expansion. Note that mudflap depends on the format
999 of the emitted code: see mx_register_decls(). */
1000 tree t, args, addr, ptr_type;
1002 gimplify_one_sizepos (&DECL_SIZE (decl), stmt_p);
1003 gimplify_one_sizepos (&DECL_SIZE_UNIT (decl), stmt_p);
1005 /* All occurrences of this decl in final gimplified code will be
1006 replaced by indirection. Setting DECL_VALUE_EXPR does two
1007 things: First, it lets the rest of the gimplifier know what
1008 replacement to use. Second, it lets the debug info know
1009 where to find the value. */
1010 ptr_type = build_pointer_type (TREE_TYPE (decl));
1011 addr = create_tmp_var (ptr_type, get_name (decl));
1012 DECL_IGNORED_P (addr) = 0;
1013 t = build_fold_indirect_ref (addr);
1014 DECL_VALUE_EXPR (decl) = t;
1016 args = tree_cons (NULL, DECL_SIZE_UNIT (decl), NULL);
1017 t = built_in_decls[BUILT_IN_ALLOCA];
1018 t = build_function_call_expr (t, args);
1019 t = fold_convert (ptr_type, t);
1020 t = build2 (MODIFY_EXPR, void_type_node, addr, t);
1022 gimplify_and_add (t, stmt_p);
1024 /* Indicate that we need to restore the stack level when the
1025 enclosing BIND_EXPR is exited. */
1026 gimplify_ctxp->save_stack = true;
1029 if (init && init != error_mark_node)
1031 if (!TREE_STATIC (decl))
1033 DECL_INITIAL (decl) = NULL_TREE;
1034 init = build (MODIFY_EXPR, void_type_node, decl, init);
1035 gimplify_and_add (init, stmt_p);
1038 /* We must still examine initializers for static variables
1039 as they may contain a label address. */
1040 walk_tree (&init, force_labels_r, NULL, NULL);
1043 /* This decl isn't mentioned in the enclosing block, so add it to the
1044 list of temps. FIXME it seems a bit of a kludge to say that
1045 anonymous artificial vars aren't pushed, but everything else is. */
1046 if (DECL_ARTIFICIAL (decl) && DECL_NAME (decl) == NULL_TREE)
1047 gimple_add_tmp_var (decl);
1053 /* Gimplify a LOOP_EXPR. Normally this just involves gimplifying the body
1054 and replacing the LOOP_EXPR with goto, but if the loop contains an
1055 EXIT_EXPR, we need to append a label for it to jump to. */
1057 static enum gimplify_status
1058 gimplify_loop_expr (tree *expr_p, tree *pre_p)
1060 tree saved_label = gimplify_ctxp->exit_label;
1061 tree start_label = build1 (LABEL_EXPR, void_type_node, NULL_TREE);
1062 tree jump_stmt = build_and_jump (&LABEL_EXPR_LABEL (start_label));
1064 append_to_statement_list (start_label, pre_p);
1066 gimplify_ctxp->exit_label = NULL_TREE;
1068 gimplify_and_add (LOOP_EXPR_BODY (*expr_p), pre_p);
1070 if (gimplify_ctxp->exit_label)
1072 append_to_statement_list (jump_stmt, pre_p);
1073 *expr_p = build1 (LABEL_EXPR, void_type_node, gimplify_ctxp->exit_label);
1076 *expr_p = jump_stmt;
1078 gimplify_ctxp->exit_label = saved_label;
1083 /* Compare two case labels. Because the front end should already have
1084 made sure that case ranges do not overlap, it is enough to only compare
1085 the CASE_LOW values of each case label. */
1088 compare_case_labels (const void *p1, const void *p2)
1090 tree case1 = *(tree *)p1;
1091 tree case2 = *(tree *)p2;
1093 return tree_int_cst_compare (CASE_LOW (case1), CASE_LOW (case2));
1096 /* Sort the case labels in LABEL_VEC in place in ascending order. */
1099 sort_case_labels (tree label_vec)
1101 size_t len = TREE_VEC_LENGTH (label_vec);
1102 tree default_case = TREE_VEC_ELT (label_vec, len - 1);
1104 if (CASE_LOW (default_case))
1108 /* The last label in the vector should be the default case
1110 for (i = 0; i < len; ++i)
1112 tree t = TREE_VEC_ELT (label_vec, i);
1116 TREE_VEC_ELT (label_vec, i) = TREE_VEC_ELT (label_vec, len - 1);
1117 TREE_VEC_ELT (label_vec, len - 1) = default_case;
1123 qsort (&TREE_VEC_ELT (label_vec, 0), len - 1, sizeof (tree),
1124 compare_case_labels);
1127 /* Gimplify a SWITCH_EXPR, and collect a TREE_VEC of the labels it can
1130 static enum gimplify_status
1131 gimplify_switch_expr (tree *expr_p, tree *pre_p)
1133 tree switch_expr = *expr_p;
1134 enum gimplify_status ret;
1136 ret = gimplify_expr (&SWITCH_COND (switch_expr), pre_p, NULL,
1137 is_gimple_val, fb_rvalue);
1139 if (SWITCH_BODY (switch_expr))
1141 varray_type labels, saved_labels;
1142 tree label_vec, default_case = NULL_TREE;
1145 /* If someone can be bothered to fill in the labels, they can
1146 be bothered to null out the body too. */
1147 gcc_assert (!SWITCH_LABELS (switch_expr));
1149 saved_labels = gimplify_ctxp->case_labels;
1150 VARRAY_TREE_INIT (gimplify_ctxp->case_labels, 8, "case_labels");
1152 gimplify_to_stmt_list (&SWITCH_BODY (switch_expr));
1154 labels = gimplify_ctxp->case_labels;
1155 gimplify_ctxp->case_labels = saved_labels;
1157 len = VARRAY_ACTIVE_SIZE (labels);
1159 for (i = 0; i < len; ++i)
1161 tree t = VARRAY_TREE (labels, i);
1164 /* The default case must be the last label in the list. */
1166 VARRAY_TREE (labels, i) = VARRAY_TREE (labels, len - 1);
1172 label_vec = make_tree_vec (len + 1);
1173 SWITCH_LABELS (*expr_p) = label_vec;
1174 append_to_statement_list (switch_expr, pre_p);
1178 /* If the switch has no default label, add one, so that we jump
1179 around the switch body. */
1180 default_case = build (CASE_LABEL_EXPR, void_type_node, NULL_TREE,
1181 NULL_TREE, create_artificial_label ());
1182 append_to_statement_list (SWITCH_BODY (switch_expr), pre_p);
1183 *expr_p = build (LABEL_EXPR, void_type_node,
1184 CASE_LABEL (default_case));
1187 *expr_p = SWITCH_BODY (switch_expr);
1189 for (i = 0; i < len; ++i)
1190 TREE_VEC_ELT (label_vec, i) = VARRAY_TREE (labels, i);
1191 TREE_VEC_ELT (label_vec, len) = default_case;
1193 sort_case_labels (label_vec);
1195 SWITCH_BODY (switch_expr) = NULL;
1198 gcc_assert (SWITCH_LABELS (switch_expr));
1203 static enum gimplify_status
1204 gimplify_case_label_expr (tree *expr_p)
1206 tree expr = *expr_p;
1208 gcc_assert (gimplify_ctxp->case_labels);
1209 VARRAY_PUSH_TREE (gimplify_ctxp->case_labels, expr);
1210 *expr_p = build (LABEL_EXPR, void_type_node, CASE_LABEL (expr));
1214 /* Build a GOTO to the LABEL_DECL pointed to by LABEL_P, building it first
1218 build_and_jump (tree *label_p)
1220 if (label_p == NULL)
1221 /* If there's nowhere to jump, just fall through. */
1224 if (*label_p == NULL_TREE)
1226 tree label = create_artificial_label ();
1230 return build1 (GOTO_EXPR, void_type_node, *label_p);
1233 /* Gimplify an EXIT_EXPR by converting to a GOTO_EXPR inside a COND_EXPR.
1234 This also involves building a label to jump to and communicating it to
1235 gimplify_loop_expr through gimplify_ctxp->exit_label. */
1237 static enum gimplify_status
1238 gimplify_exit_expr (tree *expr_p)
1240 tree cond = TREE_OPERAND (*expr_p, 0);
1243 expr = build_and_jump (&gimplify_ctxp->exit_label);
1244 expr = build (COND_EXPR, void_type_node, cond, expr, NULL_TREE);
1250 /* A helper function to be called via walk_tree. Mark all labels under *TP
1251 as being forced. To be called for DECL_INITIAL of static variables. */
1254 force_labels_r (tree *tp, int *walk_subtrees, void *data ATTRIBUTE_UNUSED)
1258 if (TREE_CODE (*tp) == LABEL_DECL)
1259 FORCED_LABEL (*tp) = 1;
1264 /* *EXPR_P is a COMPONENT_REF being used as an rvalue. If its type is
1265 different from its canonical type, wrap the whole thing inside a
1266 NOP_EXPR and force the type of the COMPONENT_REF to be the canonical
1269 The canonical type of a COMPONENT_REF is the type of the field being
1270 referenced--unless the field is a bit-field which can be read directly
1271 in a smaller mode, in which case the canonical type is the
1272 sign-appropriate type corresponding to that mode. */
1275 canonicalize_component_ref (tree *expr_p)
1277 tree expr = *expr_p;
1280 gcc_assert (TREE_CODE (expr) == COMPONENT_REF);
1282 if (INTEGRAL_TYPE_P (TREE_TYPE (expr)))
1283 type = TREE_TYPE (get_unwidened (expr, NULL_TREE));
1285 type = TREE_TYPE (TREE_OPERAND (expr, 1));
1287 if (TREE_TYPE (expr) != type)
1289 tree old_type = TREE_TYPE (expr);
1291 /* Set the type of the COMPONENT_REF to the underlying type. */
1292 TREE_TYPE (expr) = type;
1294 /* And wrap the whole thing inside a NOP_EXPR. */
1295 expr = build1 (NOP_EXPR, old_type, expr);
1301 /* If a NOP conversion is changing a pointer to array of foo to a pointer
1302 to foo, embed that change in the ADDR_EXPR by converting
1307 where L is the lower bound. For simplicity, only do this for constant
1311 canonicalize_addr_expr (tree *expr_p)
1313 tree expr = *expr_p;
1314 tree ctype = TREE_TYPE (expr);
1315 tree addr_expr = TREE_OPERAND (expr, 0);
1316 tree atype = TREE_TYPE (addr_expr);
1317 tree dctype, datype, ddatype, otype, obj_expr;
1319 /* Both cast and addr_expr types should be pointers. */
1320 if (!POINTER_TYPE_P (ctype) || !POINTER_TYPE_P (atype))
1323 /* The addr_expr type should be a pointer to an array. */
1324 datype = TREE_TYPE (atype);
1325 if (TREE_CODE (datype) != ARRAY_TYPE)
1328 /* Both cast and addr_expr types should address the same object type. */
1329 dctype = TREE_TYPE (ctype);
1330 ddatype = TREE_TYPE (datype);
1331 if (!lang_hooks.types_compatible_p (ddatype, dctype))
1334 /* The addr_expr and the object type should match. */
1335 obj_expr = TREE_OPERAND (addr_expr, 0);
1336 otype = TREE_TYPE (obj_expr);
1337 if (!lang_hooks.types_compatible_p (otype, datype))
1340 /* The lower bound and element sizes must be constant. */
1341 if (!TYPE_SIZE_UNIT (dctype)
1342 || TREE_CODE (TYPE_SIZE_UNIT (dctype)) != INTEGER_CST
1343 || !TYPE_DOMAIN (datype) || !TYPE_MIN_VALUE (TYPE_DOMAIN (datype))
1344 || TREE_CODE (TYPE_MIN_VALUE (TYPE_DOMAIN (datype))) != INTEGER_CST)
1347 /* All checks succeeded. Build a new node to merge the cast. */
1348 *expr_p = build4 (ARRAY_REF, dctype, obj_expr,
1349 TYPE_MIN_VALUE (TYPE_DOMAIN (datype)),
1350 TYPE_MIN_VALUE (TYPE_DOMAIN (datype)),
1351 size_binop (EXACT_DIV_EXPR, TYPE_SIZE_UNIT (dctype),
1352 size_int (TYPE_ALIGN_UNIT (dctype))));
1353 *expr_p = build1 (ADDR_EXPR, ctype, *expr_p);
1356 /* *EXPR_P is a NOP_EXPR or CONVERT_EXPR. Remove it and/or other conversions
1357 underneath as appropriate. */
1359 static enum gimplify_status
1360 gimplify_conversion (tree *expr_p)
1362 gcc_assert (TREE_CODE (*expr_p) == NOP_EXPR
1363 || TREE_CODE (*expr_p) == CONVERT_EXPR);
1365 /* Then strip away all but the outermost conversion. */
1366 STRIP_SIGN_NOPS (TREE_OPERAND (*expr_p, 0));
1368 /* And remove the outermost conversion if it's useless. */
1369 if (tree_ssa_useless_type_conversion (*expr_p))
1370 *expr_p = TREE_OPERAND (*expr_p, 0);
1372 /* If we still have a conversion at the toplevel,
1373 then canonicalize some constructs. */
1374 if (TREE_CODE (*expr_p) == NOP_EXPR || TREE_CODE (*expr_p) == CONVERT_EXPR)
1376 tree sub = TREE_OPERAND (*expr_p, 0);
1378 /* If a NOP conversion is changing the type of a COMPONENT_REF
1379 expression, then canonicalize its type now in order to expose more
1380 redundant conversions. */
1381 if (TREE_CODE (sub) == COMPONENT_REF)
1382 canonicalize_component_ref (&TREE_OPERAND (*expr_p, 0));
1384 /* If a NOP conversion is changing a pointer to array of foo
1385 to a pointer to foo, embed that change in the ADDR_EXPR. */
1386 else if (TREE_CODE (sub) == ADDR_EXPR)
1387 canonicalize_addr_expr (expr_p);
1393 /* Gimplify the COMPONENT_REF, ARRAY_REF, REALPART_EXPR or IMAGPART_EXPR
1394 node pointed by EXPR_P.
1397 : min_lval '[' val ']'
1399 | compound_lval '[' val ']'
1400 | compound_lval '.' ID
1402 This is not part of the original SIMPLE definition, which separates
1403 array and member references, but it seems reasonable to handle them
1404 together. Also, this way we don't run into problems with union
1405 aliasing; gcc requires that for accesses through a union to alias, the
1406 union reference must be explicit, which was not always the case when we
1407 were splitting up array and member refs.
1409 PRE_P points to the list where side effects that must happen before
1410 *EXPR_P should be stored.
1412 POST_P points to the list where side effects that must happen after
1413 *EXPR_P should be stored. */
1415 static enum gimplify_status
1416 gimplify_compound_lval (tree *expr_p, tree *pre_p,
1417 tree *post_p, fallback_t fallback)
1421 enum gimplify_status ret = GS_OK, tret;
1424 /* Create a stack of the subexpressions so later we can walk them in
1425 order from inner to outer.
1427 This array is very memory consuming. Don't even think of making
1429 VARRAY_GENERIC_PTR_NOGC_INIT (stack, 10, "stack");
1431 /* We can handle anything that get_inner_reference can deal with. */
1432 for (p = expr_p; ; p = &TREE_OPERAND (*p, 0))
1434 /* Fold INDIRECT_REFs now to turn them into ARRAY_REFs. */
1435 if (TREE_CODE (*p) == INDIRECT_REF)
1436 *p = fold_indirect_ref (*p);
1437 if (!handled_component_p (*p))
1439 VARRAY_PUSH_GENERIC_PTR_NOGC (stack, *p);
1442 gcc_assert (VARRAY_ACTIVE_SIZE (stack));
1444 /* Now STACK is a stack of pointers to all the refs we've walked through
1445 and P points to the innermost expression.
1447 Java requires that we elaborated nodes in source order. That
1448 means we must gimplify the inner expression followed by each of
1449 the indices, in order. But we can't gimplify the inner
1450 expression until we deal with any variable bounds, sizes, or
1451 positions in order to deal with PLACEHOLDER_EXPRs.
1453 So we do this in three steps. First we deal with the annotations
1454 for any variables in the components, then we gimplify the base,
1455 then we gimplify any indices, from left to right. */
1456 for (i = VARRAY_ACTIVE_SIZE (stack) - 1; i >= 0; i--)
1458 tree t = VARRAY_GENERIC_PTR_NOGC (stack, i);
1460 if (TREE_CODE (t) == ARRAY_REF || TREE_CODE (t) == ARRAY_RANGE_REF)
1462 /* Gimplify the low bound and element type size and put them into
1463 the ARRAY_REF. If these values are set, they have already been
1465 if (!TREE_OPERAND (t, 2))
1467 tree low = unshare_expr (array_ref_low_bound (t));
1468 if (!is_gimple_min_invariant (low))
1470 TREE_OPERAND (t, 2) = low;
1471 tret = gimplify_expr (&TREE_OPERAND (t, 2), pre_p, post_p,
1472 is_gimple_formal_tmp_reg, fb_rvalue);
1473 ret = MIN (ret, tret);
1477 if (!TREE_OPERAND (t, 3))
1479 tree elmt_type = TREE_TYPE (TREE_TYPE (TREE_OPERAND (t, 0)));
1480 tree elmt_size = unshare_expr (array_ref_element_size (t));
1481 tree factor = size_int (TYPE_ALIGN_UNIT (elmt_type));
1483 /* Divide the element size by the alignment of the element
1485 elmt_size = size_binop (EXACT_DIV_EXPR, elmt_size, factor);
1487 if (!is_gimple_min_invariant (elmt_size))
1489 TREE_OPERAND (t, 3) = elmt_size;
1490 tret = gimplify_expr (&TREE_OPERAND (t, 3), pre_p, post_p,
1491 is_gimple_formal_tmp_reg, fb_rvalue);
1492 ret = MIN (ret, tret);
1496 else if (TREE_CODE (t) == COMPONENT_REF)
1498 /* Set the field offset into T and gimplify it. */
1499 if (!TREE_OPERAND (t, 2))
1501 tree offset = unshare_expr (component_ref_field_offset (t));
1502 tree field = TREE_OPERAND (t, 1);
1504 = size_int (DECL_OFFSET_ALIGN (field) / BITS_PER_UNIT);
1506 /* Divide the offset by its alignment. */
1507 offset = size_binop (EXACT_DIV_EXPR, offset, factor);
1509 if (!is_gimple_min_invariant (offset))
1511 TREE_OPERAND (t, 2) = offset;
1512 tret = gimplify_expr (&TREE_OPERAND (t, 2), pre_p, post_p,
1513 is_gimple_formal_tmp_reg, fb_rvalue);
1514 ret = MIN (ret, tret);
1520 /* Step 2 is to gimplify the base expression. */
1521 tret = gimplify_expr (p, pre_p, post_p, is_gimple_min_lval, fallback);
1522 ret = MIN (ret, tret);
1524 /* And finally, the indices and operands to BIT_FIELD_REF. During this
1525 loop we also remove any useless conversions. */
1526 for (; VARRAY_ACTIVE_SIZE (stack) > 0; )
1528 tree t = VARRAY_TOP_TREE (stack);
1530 if (TREE_CODE (t) == ARRAY_REF || TREE_CODE (t) == ARRAY_RANGE_REF)
1532 /* Gimplify the dimension.
1533 Temporary fix for gcc.c-torture/execute/20040313-1.c.
1534 Gimplify non-constant array indices into a temporary
1536 FIXME - The real fix is to gimplify post-modify
1537 expressions into a minimal gimple lvalue. However, that
1538 exposes bugs in alias analysis. The alias analyzer does
1539 not handle &PTR->FIELD very well. Will fix after the
1540 branch is merged into mainline (dnovillo 2004-05-03). */
1541 if (!is_gimple_min_invariant (TREE_OPERAND (t, 1)))
1543 tret = gimplify_expr (&TREE_OPERAND (t, 1), pre_p, post_p,
1544 is_gimple_formal_tmp_reg, fb_rvalue);
1545 ret = MIN (ret, tret);
1548 else if (TREE_CODE (t) == BIT_FIELD_REF)
1550 tret = gimplify_expr (&TREE_OPERAND (t, 1), pre_p, post_p,
1551 is_gimple_val, fb_rvalue);
1552 ret = MIN (ret, tret);
1553 tret = gimplify_expr (&TREE_OPERAND (t, 2), pre_p, post_p,
1554 is_gimple_val, fb_rvalue);
1555 ret = MIN (ret, tret);
1558 STRIP_USELESS_TYPE_CONVERSION (TREE_OPERAND (t, 0));
1560 /* The innermost expression P may have originally had TREE_SIDE_EFFECTS
1561 set which would have caused all the outer expressions in EXPR_P
1562 leading to P to also have had TREE_SIDE_EFFECTS set. */
1563 recalculate_side_effects (t);
1567 tret = gimplify_expr (p, pre_p, post_p, is_gimple_min_lval, fallback);
1568 ret = MIN (ret, tret);
1570 /* If the outermost expression is a COMPONENT_REF, canonicalize its type. */
1571 if ((fallback & fb_rvalue) && TREE_CODE (*expr_p) == COMPONENT_REF)
1573 canonicalize_component_ref (expr_p);
1574 ret = MIN (ret, GS_OK);
1577 VARRAY_FREE (stack);
1582 /* Gimplify the self modifying expression pointed by EXPR_P (++, --, +=, -=).
1584 PRE_P points to the list where side effects that must happen before
1585 *EXPR_P should be stored.
1587 POST_P points to the list where side effects that must happen after
1588 *EXPR_P should be stored.
1590 WANT_VALUE is nonzero iff we want to use the value of this expression
1591 in another expression. */
1593 static enum gimplify_status
1594 gimplify_self_mod_expr (tree *expr_p, tree *pre_p, tree *post_p,
1597 enum tree_code code;
1598 tree lhs, lvalue, rhs, t1;
1600 enum tree_code arith_code;
1601 enum gimplify_status ret;
1603 code = TREE_CODE (*expr_p);
1605 gcc_assert (code == POSTINCREMENT_EXPR || code == POSTDECREMENT_EXPR
1606 || code == PREINCREMENT_EXPR || code == PREDECREMENT_EXPR);
1608 /* Prefix or postfix? */
1609 if (code == POSTINCREMENT_EXPR || code == POSTDECREMENT_EXPR)
1610 /* Faster to treat as prefix if result is not used. */
1611 postfix = want_value;
1615 /* Add or subtract? */
1616 if (code == PREINCREMENT_EXPR || code == POSTINCREMENT_EXPR)
1617 arith_code = PLUS_EXPR;
1619 arith_code = MINUS_EXPR;
1621 /* Gimplify the LHS into a GIMPLE lvalue. */
1622 lvalue = TREE_OPERAND (*expr_p, 0);
1623 ret = gimplify_expr (&lvalue, pre_p, post_p, is_gimple_lvalue, fb_lvalue);
1624 if (ret == GS_ERROR)
1627 /* Extract the operands to the arithmetic operation. */
1629 rhs = TREE_OPERAND (*expr_p, 1);
1631 /* For postfix operator, we evaluate the LHS to an rvalue and then use
1632 that as the result value and in the postqueue operation. */
1635 ret = gimplify_expr (&lhs, pre_p, post_p, is_gimple_val, fb_rvalue);
1636 if (ret == GS_ERROR)
1640 t1 = build (arith_code, TREE_TYPE (*expr_p), lhs, rhs);
1641 t1 = build (MODIFY_EXPR, TREE_TYPE (lvalue), lvalue, t1);
1645 gimplify_and_add (t1, post_p);
1656 /* If *EXPR_P has a variable sized type, wrap it in a WITH_SIZE_EXPR. */
1659 maybe_with_size_expr (tree *expr_p)
1661 tree expr = *expr_p;
1662 tree type = TREE_TYPE (expr);
1665 /* If we've already wrapped this or the type is error_mark_node, we can't do
1667 if (TREE_CODE (expr) == WITH_SIZE_EXPR
1668 || type == error_mark_node)
1671 /* If the size isn't known or is a constant, we have nothing to do. */
1672 size = TYPE_SIZE_UNIT (type);
1673 if (!size || TREE_CODE (size) == INTEGER_CST)
1676 /* Otherwise, make a WITH_SIZE_EXPR. */
1677 size = unshare_expr (size);
1678 size = SUBSTITUTE_PLACEHOLDER_IN_EXPR (size, expr);
1679 *expr_p = build2 (WITH_SIZE_EXPR, type, expr, size);
1682 /* Subroutine of gimplify_call_expr: Gimplify a single argument. */
1684 static enum gimplify_status
1685 gimplify_arg (tree *expr_p, tree *pre_p)
1687 bool (*test) (tree);
1690 /* In general, we allow lvalues for function arguments to avoid
1691 extra overhead of copying large aggregates out of even larger
1692 aggregates into temporaries only to copy the temporaries to
1693 the argument list. Make optimizers happy by pulling out to
1694 temporaries those types that fit in registers. */
1695 if (is_gimple_reg_type (TREE_TYPE (*expr_p)))
1696 test = is_gimple_val, fb = fb_rvalue;
1698 test = is_gimple_lvalue, fb = fb_either;
1700 /* If this is a variable sized type, we must remember the size. */
1701 maybe_with_size_expr (expr_p);
1703 /* There is a sequence point before a function call. Side effects in
1704 the argument list must occur before the actual call. So, when
1705 gimplifying arguments, force gimplify_expr to use an internal
1706 post queue which is then appended to the end of PRE_P. */
1707 return gimplify_expr (expr_p, pre_p, NULL, test, fb);
1710 /* Gimplify the CALL_EXPR node pointed by EXPR_P. PRE_P points to the
1711 list where side effects that must happen before *EXPR_P should be stored.
1712 WANT_VALUE is true if the result of the call is desired. */
1714 static enum gimplify_status
1715 gimplify_call_expr (tree *expr_p, tree *pre_p, bool want_value)
1719 enum gimplify_status ret;
1721 gcc_assert (TREE_CODE (*expr_p) == CALL_EXPR);
1723 /* For reliable diagnostics during inlining, it is necessary that
1724 every call_expr be annotated with file and line. */
1725 if (! EXPR_HAS_LOCATION (*expr_p))
1726 SET_EXPR_LOCATION (*expr_p, input_location);
1728 /* This may be a call to a builtin function.
1730 Builtin function calls may be transformed into different
1731 (and more efficient) builtin function calls under certain
1732 circumstances. Unfortunately, gimplification can muck things
1733 up enough that the builtin expanders are not aware that certain
1734 transformations are still valid.
1736 So we attempt transformation/gimplification of the call before
1737 we gimplify the CALL_EXPR. At this time we do not manage to
1738 transform all calls in the same manner as the expanders do, but
1739 we do transform most of them. */
1740 decl = get_callee_fndecl (*expr_p);
1741 if (decl && DECL_BUILT_IN (decl))
1743 tree new = fold_builtin (*expr_p, !want_value);
1745 if (new && new != *expr_p)
1747 /* There was a transformation of this call which computes the
1748 same value, but in a more efficient way. Return and try
1754 if (DECL_BUILT_IN_CLASS (decl) == BUILT_IN_NORMAL
1755 && DECL_FUNCTION_CODE (decl) == BUILT_IN_VA_START)
1757 tree arglist = TREE_OPERAND (*expr_p, 1);
1759 if (!arglist || !TREE_CHAIN (arglist))
1761 error ("too few arguments to function %<va_start%>");
1762 *expr_p = build_empty_stmt ();
1766 if (fold_builtin_next_arg (TREE_CHAIN (arglist)))
1768 *expr_p = build_empty_stmt ();
1771 /* Avoid gimplifying the second argument to va_start, which needs
1772 to be the plain PARM_DECL. */
1773 return gimplify_arg (&TREE_VALUE (TREE_OPERAND (*expr_p, 1)), pre_p);
1777 /* There is a sequence point before the call, so any side effects in
1778 the calling expression must occur before the actual call. Force
1779 gimplify_expr to use an internal post queue. */
1780 ret = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p, NULL,
1781 is_gimple_call_addr, fb_rvalue);
1783 if (PUSH_ARGS_REVERSED)
1784 TREE_OPERAND (*expr_p, 1) = nreverse (TREE_OPERAND (*expr_p, 1));
1785 for (arglist = TREE_OPERAND (*expr_p, 1); arglist;
1786 arglist = TREE_CHAIN (arglist))
1788 enum gimplify_status t;
1790 t = gimplify_arg (&TREE_VALUE (arglist), pre_p);
1795 if (PUSH_ARGS_REVERSED)
1796 TREE_OPERAND (*expr_p, 1) = nreverse (TREE_OPERAND (*expr_p, 1));
1798 /* Try this again in case gimplification exposed something. */
1799 if (ret != GS_ERROR && decl && DECL_BUILT_IN (decl))
1801 tree new = fold_builtin (*expr_p, !want_value);
1803 if (new && new != *expr_p)
1805 /* There was a transformation of this call which computes the
1806 same value, but in a more efficient way. Return and try
1813 /* If the function is "const" or "pure", then clear TREE_SIDE_EFFECTS on its
1814 decl. This allows us to eliminate redundant or useless
1815 calls to "const" functions. */
1816 if (TREE_CODE (*expr_p) == CALL_EXPR
1817 && (call_expr_flags (*expr_p) & (ECF_CONST | ECF_PURE)))
1818 TREE_SIDE_EFFECTS (*expr_p) = 0;
1823 /* Handle shortcut semantics in the predicate operand of a COND_EXPR by
1824 rewriting it into multiple COND_EXPRs, and possibly GOTO_EXPRs.
1826 TRUE_LABEL_P and FALSE_LABEL_P point to the labels to jump to if the
1827 condition is true or false, respectively. If null, we should generate
1828 our own to skip over the evaluation of this specific expression.
1830 This function is the tree equivalent of do_jump.
1832 shortcut_cond_r should only be called by shortcut_cond_expr. */
1835 shortcut_cond_r (tree pred, tree *true_label_p, tree *false_label_p)
1837 tree local_label = NULL_TREE;
1838 tree t, expr = NULL;
1840 /* OK, it's not a simple case; we need to pull apart the COND_EXPR to
1841 retain the shortcut semantics. Just insert the gotos here;
1842 shortcut_cond_expr will append the real blocks later. */
1843 if (TREE_CODE (pred) == TRUTH_ANDIF_EXPR)
1845 /* Turn if (a && b) into
1847 if (a); else goto no;
1848 if (b) goto yes; else goto no;
1851 if (false_label_p == NULL)
1852 false_label_p = &local_label;
1854 t = shortcut_cond_r (TREE_OPERAND (pred, 0), NULL, false_label_p);
1855 append_to_statement_list (t, &expr);
1857 t = shortcut_cond_r (TREE_OPERAND (pred, 1), true_label_p,
1859 append_to_statement_list (t, &expr);
1861 else if (TREE_CODE (pred) == TRUTH_ORIF_EXPR)
1863 /* Turn if (a || b) into
1866 if (b) goto yes; else goto no;
1869 if (true_label_p == NULL)
1870 true_label_p = &local_label;
1872 t = shortcut_cond_r (TREE_OPERAND (pred, 0), true_label_p, NULL);
1873 append_to_statement_list (t, &expr);
1875 t = shortcut_cond_r (TREE_OPERAND (pred, 1), true_label_p,
1877 append_to_statement_list (t, &expr);
1879 else if (TREE_CODE (pred) == COND_EXPR)
1881 /* As long as we're messing with gotos, turn if (a ? b : c) into
1883 if (b) goto yes; else goto no;
1885 if (c) goto yes; else goto no; */
1886 expr = build (COND_EXPR, void_type_node, TREE_OPERAND (pred, 0),
1887 shortcut_cond_r (TREE_OPERAND (pred, 1), true_label_p,
1889 shortcut_cond_r (TREE_OPERAND (pred, 2), true_label_p,
1894 expr = build (COND_EXPR, void_type_node, pred,
1895 build_and_jump (true_label_p),
1896 build_and_jump (false_label_p));
1901 t = build1 (LABEL_EXPR, void_type_node, local_label);
1902 append_to_statement_list (t, &expr);
1909 shortcut_cond_expr (tree expr)
1911 tree pred = TREE_OPERAND (expr, 0);
1912 tree then_ = TREE_OPERAND (expr, 1);
1913 tree else_ = TREE_OPERAND (expr, 2);
1914 tree true_label, false_label, end_label, t;
1916 tree *false_label_p;
1917 bool emit_end, emit_false, jump_over_else;
1918 bool then_se = then_ && TREE_SIDE_EFFECTS (then_);
1919 bool else_se = else_ && TREE_SIDE_EFFECTS (else_);
1921 /* First do simple transformations. */
1924 /* If there is no 'else', turn (a && b) into if (a) if (b). */
1925 while (TREE_CODE (pred) == TRUTH_ANDIF_EXPR)
1927 TREE_OPERAND (expr, 0) = TREE_OPERAND (pred, 1);
1928 then_ = shortcut_cond_expr (expr);
1929 then_se = then_ && TREE_SIDE_EFFECTS (then_);
1930 pred = TREE_OPERAND (pred, 0);
1931 expr = build (COND_EXPR, void_type_node, pred, then_, NULL_TREE);
1936 /* If there is no 'then', turn
1939 if (a); else if (b); else d. */
1940 while (TREE_CODE (pred) == TRUTH_ORIF_EXPR)
1942 TREE_OPERAND (expr, 0) = TREE_OPERAND (pred, 1);
1943 else_ = shortcut_cond_expr (expr);
1944 else_se = else_ && TREE_SIDE_EFFECTS (else_);
1945 pred = TREE_OPERAND (pred, 0);
1946 expr = build (COND_EXPR, void_type_node, pred, NULL_TREE, else_);
1950 /* If we're done, great. */
1951 if (TREE_CODE (pred) != TRUTH_ANDIF_EXPR
1952 && TREE_CODE (pred) != TRUTH_ORIF_EXPR)
1955 /* Otherwise we need to mess with gotos. Change
1958 if (a); else goto no;
1961 and recursively gimplify the condition. */
1963 true_label = false_label = end_label = NULL_TREE;
1965 /* If our arms just jump somewhere, hijack those labels so we don't
1966 generate jumps to jumps. */
1969 && TREE_CODE (then_) == GOTO_EXPR
1970 && TREE_CODE (GOTO_DESTINATION (then_)) == LABEL_DECL)
1972 true_label = GOTO_DESTINATION (then_);
1978 && TREE_CODE (else_) == GOTO_EXPR
1979 && TREE_CODE (GOTO_DESTINATION (else_)) == LABEL_DECL)
1981 false_label = GOTO_DESTINATION (else_);
1986 /* If we aren't hijacking a label for the 'then' branch, it falls through. */
1988 true_label_p = &true_label;
1990 true_label_p = NULL;
1992 /* The 'else' branch also needs a label if it contains interesting code. */
1993 if (false_label || else_se)
1994 false_label_p = &false_label;
1996 false_label_p = NULL;
1998 /* If there was nothing else in our arms, just forward the label(s). */
1999 if (!then_se && !else_se)
2000 return shortcut_cond_r (pred, true_label_p, false_label_p);
2002 /* If our last subexpression already has a terminal label, reuse it. */
2004 expr = expr_last (else_);
2006 expr = expr_last (then_);
2009 if (expr && TREE_CODE (expr) == LABEL_EXPR)
2010 end_label = LABEL_EXPR_LABEL (expr);
2012 /* If we don't care about jumping to the 'else' branch, jump to the end
2013 if the condition is false. */
2015 false_label_p = &end_label;
2017 /* We only want to emit these labels if we aren't hijacking them. */
2018 emit_end = (end_label == NULL_TREE);
2019 emit_false = (false_label == NULL_TREE);
2021 /* We only emit the jump over the else clause if we have to--if the
2022 then clause may fall through. Otherwise we can wind up with a
2023 useless jump and a useless label at the end of gimplified code,
2024 which will cause us to think that this conditional as a whole
2025 falls through even if it doesn't. If we then inline a function
2026 which ends with such a condition, that can cause us to issue an
2027 inappropriate warning about control reaching the end of a
2028 non-void function. */
2029 jump_over_else = block_may_fallthru (then_);
2031 pred = shortcut_cond_r (pred, true_label_p, false_label_p);
2034 append_to_statement_list (pred, &expr);
2036 append_to_statement_list (then_, &expr);
2041 t = build_and_jump (&end_label);
2042 append_to_statement_list (t, &expr);
2046 t = build1 (LABEL_EXPR, void_type_node, false_label);
2047 append_to_statement_list (t, &expr);
2049 append_to_statement_list (else_, &expr);
2051 if (emit_end && end_label)
2053 t = build1 (LABEL_EXPR, void_type_node, end_label);
2054 append_to_statement_list (t, &expr);
2060 /* EXPR is used in a boolean context; make sure it has BOOLEAN_TYPE. */
2063 gimple_boolify (tree expr)
2065 tree type = TREE_TYPE (expr);
2067 if (TREE_CODE (type) == BOOLEAN_TYPE)
2070 /* If this is the predicate of a COND_EXPR, it might not even be a
2072 expr = lang_hooks.truthvalue_conversion (expr);
2074 switch (TREE_CODE (expr))
2076 case TRUTH_AND_EXPR:
2078 case TRUTH_XOR_EXPR:
2079 case TRUTH_ANDIF_EXPR:
2080 case TRUTH_ORIF_EXPR:
2081 /* Also boolify the arguments of truth exprs. */
2082 TREE_OPERAND (expr, 1) = gimple_boolify (TREE_OPERAND (expr, 1));
2085 case TRUTH_NOT_EXPR:
2086 TREE_OPERAND (expr, 0) = gimple_boolify (TREE_OPERAND (expr, 0));
2089 case EQ_EXPR: case NE_EXPR:
2090 case LE_EXPR: case GE_EXPR: case LT_EXPR: case GT_EXPR:
2091 /* These expressions always produce boolean results. */
2092 TREE_TYPE (expr) = boolean_type_node;
2096 /* Other expressions that get here must have boolean values, but
2097 might need to be converted to the appropriate mode. */
2098 return convert (boolean_type_node, expr);
2102 /* Convert the conditional expression pointed by EXPR_P '(p) ? a : b;'
2111 The second form is used when *EXPR_P is of type void.
2113 TARGET is the tree for T1 above.
2115 PRE_P points to the list where side effects that must happen before
2116 *EXPR_P should be stored.
2118 POST_P points to the list where side effects that must happen after
2119 *EXPR_P should be stored. */
2121 static enum gimplify_status
2122 gimplify_cond_expr (tree *expr_p, tree *pre_p, tree *post_p, tree target,
2123 fallback_t fallback)
2125 tree expr = *expr_p;
2126 tree tmp, tmp2, type;
2127 enum gimplify_status ret;
2129 type = TREE_TYPE (expr);
2131 TREE_TYPE (expr) = void_type_node;
2133 /* If this COND_EXPR has a value, copy the values into a temporary within
2135 else if (! VOID_TYPE_P (type))
2141 ret = gimplify_expr (&target, pre_p, post_p,
2142 is_gimple_min_lval, fb_lvalue);
2143 if (ret != GS_ERROR)
2145 result = tmp = target;
2146 tmp2 = unshare_expr (target);
2148 else if ((fallback & fb_lvalue) == 0)
2150 result = tmp2 = tmp = create_tmp_var (TREE_TYPE (expr), "iftmp");
2155 tree type = build_pointer_type (TREE_TYPE (expr));
2157 if (TREE_TYPE (TREE_OPERAND (expr, 1)) != void_type_node)
2158 TREE_OPERAND (expr, 1) =
2159 build_fold_addr_expr (TREE_OPERAND (expr, 1));
2161 if (TREE_TYPE (TREE_OPERAND (expr, 2)) != void_type_node)
2162 TREE_OPERAND (expr, 2) =
2163 build_fold_addr_expr (TREE_OPERAND (expr, 2));
2165 tmp2 = tmp = create_tmp_var (type, "iftmp");
2167 expr = build (COND_EXPR, void_type_node, TREE_OPERAND (expr, 0),
2168 TREE_OPERAND (expr, 1), TREE_OPERAND (expr, 2));
2170 result = build_fold_indirect_ref (tmp);
2174 /* Build the then clause, 't1 = a;'. But don't build an assignment
2175 if this branch is void; in C++ it can be, if it's a throw. */
2176 if (TREE_TYPE (TREE_OPERAND (expr, 1)) != void_type_node)
2177 TREE_OPERAND (expr, 1)
2178 = build (MODIFY_EXPR, void_type_node, tmp, TREE_OPERAND (expr, 1));
2180 /* Build the else clause, 't1 = b;'. */
2181 if (TREE_TYPE (TREE_OPERAND (expr, 2)) != void_type_node)
2182 TREE_OPERAND (expr, 2)
2183 = build (MODIFY_EXPR, void_type_node, tmp2, TREE_OPERAND (expr, 2));
2185 TREE_TYPE (expr) = void_type_node;
2186 recalculate_side_effects (expr);
2188 /* Move the COND_EXPR to the prequeue. */
2189 gimplify_and_add (expr, pre_p);
2195 /* Make sure the condition has BOOLEAN_TYPE. */
2196 TREE_OPERAND (expr, 0) = gimple_boolify (TREE_OPERAND (expr, 0));
2198 /* Break apart && and || conditions. */
2199 if (TREE_CODE (TREE_OPERAND (expr, 0)) == TRUTH_ANDIF_EXPR
2200 || TREE_CODE (TREE_OPERAND (expr, 0)) == TRUTH_ORIF_EXPR)
2202 expr = shortcut_cond_expr (expr);
2204 if (expr != *expr_p)
2208 /* We can't rely on gimplify_expr to re-gimplify the expanded
2209 form properly, as cleanups might cause the target labels to be
2210 wrapped in a TRY_FINALLY_EXPR. To prevent that, we need to
2211 set up a conditional context. */
2212 gimple_push_condition ();
2213 gimplify_stmt (expr_p);
2214 gimple_pop_condition (pre_p);
2220 /* Now do the normal gimplification. */
2221 ret = gimplify_expr (&TREE_OPERAND (expr, 0), pre_p, NULL,
2222 is_gimple_condexpr, fb_rvalue);
2224 gimple_push_condition ();
2226 gimplify_to_stmt_list (&TREE_OPERAND (expr, 1));
2227 gimplify_to_stmt_list (&TREE_OPERAND (expr, 2));
2228 recalculate_side_effects (expr);
2230 gimple_pop_condition (pre_p);
2232 if (ret == GS_ERROR)
2234 else if (TREE_SIDE_EFFECTS (TREE_OPERAND (expr, 1)))
2236 else if (TREE_SIDE_EFFECTS (TREE_OPERAND (expr, 2)))
2237 /* Rewrite "if (a); else b" to "if (!a) b" */
2239 TREE_OPERAND (expr, 0) = invert_truthvalue (TREE_OPERAND (expr, 0));
2240 ret = gimplify_expr (&TREE_OPERAND (expr, 0), pre_p, NULL,
2241 is_gimple_condexpr, fb_rvalue);
2243 tmp = TREE_OPERAND (expr, 1);
2244 TREE_OPERAND (expr, 1) = TREE_OPERAND (expr, 2);
2245 TREE_OPERAND (expr, 2) = tmp;
2248 /* Both arms are empty; replace the COND_EXPR with its predicate. */
2249 expr = TREE_OPERAND (expr, 0);
2255 /* A subroutine of gimplify_modify_expr. Replace a MODIFY_EXPR with
2256 a call to __builtin_memcpy. */
2258 static enum gimplify_status
2259 gimplify_modify_expr_to_memcpy (tree *expr_p, tree size, bool want_value)
2261 tree args, t, to, to_ptr, from;
2263 to = TREE_OPERAND (*expr_p, 0);
2264 from = TREE_OPERAND (*expr_p, 1);
2266 args = tree_cons (NULL, size, NULL);
2268 t = build_fold_addr_expr (from);
2269 args = tree_cons (NULL, t, args);
2271 to_ptr = build_fold_addr_expr (to);
2272 args = tree_cons (NULL, to_ptr, args);
2273 t = implicit_built_in_decls[BUILT_IN_MEMCPY];
2274 t = build_function_call_expr (t, args);
2278 t = build1 (NOP_EXPR, TREE_TYPE (to_ptr), t);
2279 t = build1 (INDIRECT_REF, TREE_TYPE (to), t);
2286 /* A subroutine of gimplify_modify_expr. Replace a MODIFY_EXPR with
2287 a call to __builtin_memset. In this case we know that the RHS is
2288 a CONSTRUCTOR with an empty element list. */
2290 static enum gimplify_status
2291 gimplify_modify_expr_to_memset (tree *expr_p, tree size, bool want_value)
2293 tree args, t, to, to_ptr;
2295 to = TREE_OPERAND (*expr_p, 0);
2297 args = tree_cons (NULL, size, NULL);
2299 args = tree_cons (NULL, integer_zero_node, args);
2301 to_ptr = build_fold_addr_expr (to);
2302 args = tree_cons (NULL, to_ptr, args);
2303 t = implicit_built_in_decls[BUILT_IN_MEMSET];
2304 t = build_function_call_expr (t, args);
2308 t = build1 (NOP_EXPR, TREE_TYPE (to_ptr), t);
2309 t = build1 (INDIRECT_REF, TREE_TYPE (to), t);
2316 /* A subroutine of gimplify_init_ctor_preeval. Called via walk_tree,
2317 determine, cautiously, if a CONSTRUCTOR overlaps the lhs of an
2318 assignment. Returns non-null if we detect a potential overlap. */
2320 struct gimplify_init_ctor_preeval_data
2322 /* The base decl of the lhs object. May be NULL, in which case we
2323 have to assume the lhs is indirect. */
2326 /* The alias set of the lhs object. */
2331 gimplify_init_ctor_preeval_1 (tree *tp, int *walk_subtrees, void *xdata)
2333 struct gimplify_init_ctor_preeval_data *data
2334 = (struct gimplify_init_ctor_preeval_data *) xdata;
2337 /* If we find the base object, obviously we have overlap. */
2338 if (data->lhs_base_decl == t)
2341 /* If the constructor component is indirect, determine if we have a
2342 potential overlap with the lhs. The only bits of information we
2343 have to go on at this point are addressability and alias sets. */
2344 if (TREE_CODE (t) == INDIRECT_REF
2345 && (!data->lhs_base_decl || TREE_ADDRESSABLE (data->lhs_base_decl))
2346 && alias_sets_conflict_p (data->lhs_alias_set, get_alias_set (t)))
2349 if (IS_TYPE_OR_DECL_P (t))
2354 /* A subroutine of gimplify_init_constructor. Pre-evaluate *EXPR_P,
2355 force values that overlap with the lhs (as described by *DATA)
2356 into temporaries. */
2359 gimplify_init_ctor_preeval (tree *expr_p, tree *pre_p, tree *post_p,
2360 struct gimplify_init_ctor_preeval_data *data)
2362 enum gimplify_status one;
2364 /* If the value is invariant, then there's nothing to pre-evaluate.
2365 But ensure it doesn't have any side-effects since a SAVE_EXPR is
2366 invariant but has side effects and might contain a reference to
2367 the object we're initializing. */
2368 if (TREE_INVARIANT (*expr_p) && !TREE_SIDE_EFFECTS (*expr_p))
2371 /* If the type has non-trivial constructors, we can't pre-evaluate. */
2372 if (TREE_ADDRESSABLE (TREE_TYPE (*expr_p)))
2375 /* Recurse for nested constructors. */
2376 if (TREE_CODE (*expr_p) == CONSTRUCTOR)
2379 for (list = CONSTRUCTOR_ELTS (*expr_p); list ; list = TREE_CHAIN (list))
2380 gimplify_init_ctor_preeval (&TREE_VALUE (list), pre_p, post_p, data);
2384 /* We can't preevaluate if the type contains a placeholder. */
2385 if (type_contains_placeholder_p (TREE_TYPE (*expr_p)))
2388 /* Gimplify the constructor element to something appropriate for the rhs
2389 of a MODIFY_EXPR. Given that we know the lhs is an aggregate, we know
2390 the gimplifier will consider this a store to memory. Doing this
2391 gimplification now means that we won't have to deal with complicated
2392 language-specific trees, nor trees like SAVE_EXPR that can induce
2393 exponential search behavior. */
2394 one = gimplify_expr (expr_p, pre_p, post_p, is_gimple_mem_rhs, fb_rvalue);
2395 if (one == GS_ERROR)
2401 /* If we gimplified to a bare decl, we can be sure that it doesn't overlap
2402 with the lhs, since "a = { .x=a }" doesn't make sense. This will
2403 always be true for all scalars, since is_gimple_mem_rhs insists on a
2404 temporary variable for them. */
2405 if (DECL_P (*expr_p))
2408 /* If this is of variable size, we have no choice but to assume it doesn't
2409 overlap since we can't make a temporary for it. */
2410 if (!TREE_CONSTANT (TYPE_SIZE (TREE_TYPE (*expr_p))))
2413 /* Otherwise, we must search for overlap ... */
2414 if (!walk_tree (expr_p, gimplify_init_ctor_preeval_1, data, NULL))
2417 /* ... and if found, force the value into a temporary. */
2418 *expr_p = get_formal_tmp_var (*expr_p, pre_p);
2421 /* A subroutine of gimplify_init_ctor_eval. Create a loop for
2422 a RANGE_EXPR in a CONSTRUCTOR for an array.
2426 object[var] = value;
2433 We increment var _after_ the loop exit check because we might otherwise
2434 fail if upper == TYPE_MAX_VALUE (type for upper).
2436 Note that we never have to deal with SAVE_EXPRs here, because this has
2437 already been taken care of for us, in gimplify_init_ctor_preeval(). */
2439 static void gimplify_init_ctor_eval (tree, tree, tree *, bool);
2442 gimplify_init_ctor_eval_range (tree object, tree lower, tree upper,
2443 tree value, tree array_elt_type,
2444 tree *pre_p, bool cleared)
2446 tree loop_entry_label, loop_exit_label;
2447 tree var, var_type, cref;
2449 loop_entry_label = create_artificial_label ();
2450 loop_exit_label = create_artificial_label ();
2452 /* Create and initialize the index variable. */
2453 var_type = TREE_TYPE (upper);
2454 var = create_tmp_var (var_type, NULL);
2455 append_to_statement_list (build2 (MODIFY_EXPR, var_type, var, lower), pre_p);
2457 /* Add the loop entry label. */
2458 append_to_statement_list (build1 (LABEL_EXPR,
2463 /* Build the reference. */
2464 cref = build4 (ARRAY_REF, array_elt_type, unshare_expr (object),
2465 var, NULL_TREE, NULL_TREE);
2467 /* If we are a constructor, just call gimplify_init_ctor_eval to do
2468 the store. Otherwise just assign value to the reference. */
2470 if (TREE_CODE (value) == CONSTRUCTOR)
2471 /* NB we might have to call ourself recursively through
2472 gimplify_init_ctor_eval if the value is a constructor. */
2473 gimplify_init_ctor_eval (cref, CONSTRUCTOR_ELTS (value),
2476 append_to_statement_list (build2 (MODIFY_EXPR, TREE_TYPE (cref),
2480 /* We exit the loop when the index var is equal to the upper bound. */
2481 gimplify_and_add (build3 (COND_EXPR, void_type_node,
2482 build2 (EQ_EXPR, boolean_type_node,
2490 /* Otherwise, increment the index var... */
2491 append_to_statement_list (build2 (MODIFY_EXPR, var_type, var,
2492 build2 (PLUS_EXPR, var_type, var,
2493 fold_convert (var_type,
2494 integer_one_node))),
2497 /* ...and jump back to the loop entry. */
2498 append_to_statement_list (build1 (GOTO_EXPR,
2503 /* Add the loop exit label. */
2504 append_to_statement_list (build1 (LABEL_EXPR,
2510 /* A subroutine of gimplify_init_constructor. Generate individual
2511 MODIFY_EXPRs for a CONSTRUCTOR. OBJECT is the LHS against which the
2512 assignments should happen. LIST is the CONSTRUCTOR_ELTS of the
2513 CONSTRUCTOR. CLEARED is true if the entire LHS object has been
2517 gimplify_init_ctor_eval (tree object, tree list, tree *pre_p, bool cleared)
2519 tree array_elt_type = NULL;
2521 if (TREE_CODE (TREE_TYPE (object)) == ARRAY_TYPE)
2522 array_elt_type = TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (object)));
2524 for (; list; list = TREE_CHAIN (list))
2526 tree purpose, value, cref, init;
2528 purpose = TREE_PURPOSE (list);
2529 value = TREE_VALUE (list);
2531 /* NULL values are created above for gimplification errors. */
2535 if (cleared && initializer_zerop (value))
2538 /* ??? Here's to hoping the front end fills in all of the indices,
2539 so we don't have to figure out what's missing ourselves. */
2540 gcc_assert (purpose);
2542 /* If we have a RANGE_EXPR, we have to build a loop to assign the
2544 if (TREE_CODE (purpose) == RANGE_EXPR)
2546 tree lower = TREE_OPERAND (purpose, 0);
2547 tree upper = TREE_OPERAND (purpose, 1);
2549 /* If the lower bound is equal to upper, just treat it as if
2550 upper was the index. */
2551 if (simple_cst_equal (lower, upper))
2555 gimplify_init_ctor_eval_range (object, lower, upper, value,
2556 array_elt_type, pre_p, cleared);
2563 cref = build (ARRAY_REF, array_elt_type, unshare_expr (object),
2564 purpose, NULL_TREE, NULL_TREE);
2567 cref = build (COMPONENT_REF, TREE_TYPE (purpose),
2568 unshare_expr (object), purpose, NULL_TREE);
2570 if (TREE_CODE (value) == CONSTRUCTOR)
2571 gimplify_init_ctor_eval (cref, CONSTRUCTOR_ELTS (value),
2575 init = build (MODIFY_EXPR, TREE_TYPE (cref), cref, value);
2576 gimplify_and_add (init, pre_p);
2581 /* A subroutine of gimplify_modify_expr. Break out elements of a
2582 CONSTRUCTOR used as an initializer into separate MODIFY_EXPRs.
2584 Note that we still need to clear any elements that don't have explicit
2585 initializers, so if not all elements are initialized we keep the
2586 original MODIFY_EXPR, we just remove all of the constructor elements. */
2588 static enum gimplify_status
2589 gimplify_init_constructor (tree *expr_p, tree *pre_p,
2590 tree *post_p, bool want_value)
2593 tree ctor = TREE_OPERAND (*expr_p, 1);
2594 tree type = TREE_TYPE (ctor);
2595 enum gimplify_status ret;
2598 if (TREE_CODE (ctor) != CONSTRUCTOR)
2599 return GS_UNHANDLED;
2601 ret = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p, post_p,
2602 is_gimple_lvalue, fb_lvalue);
2603 if (ret == GS_ERROR)
2605 object = TREE_OPERAND (*expr_p, 0);
2607 elt_list = CONSTRUCTOR_ELTS (ctor);
2610 switch (TREE_CODE (type))
2614 case QUAL_UNION_TYPE:
2617 struct gimplify_init_ctor_preeval_data preeval_data;
2618 HOST_WIDE_INT num_type_elements, num_ctor_elements;
2619 HOST_WIDE_INT num_nonzero_elements, num_nonconstant_elements;
2622 /* Aggregate types must lower constructors to initialization of
2623 individual elements. The exception is that a CONSTRUCTOR node
2624 with no elements indicates zero-initialization of the whole. */
2625 if (elt_list == NULL)
2628 categorize_ctor_elements (ctor, &num_nonzero_elements,
2629 &num_nonconstant_elements,
2630 &num_ctor_elements, &cleared);
2632 /* If a const aggregate variable is being initialized, then it
2633 should never be a lose to promote the variable to be static. */
2634 if (num_nonconstant_elements == 0
2635 && num_nonzero_elements > 1
2636 && TREE_READONLY (object)
2637 && TREE_CODE (object) == VAR_DECL)
2639 DECL_INITIAL (object) = ctor;
2640 TREE_STATIC (object) = 1;
2641 if (!DECL_NAME (object))
2642 DECL_NAME (object) = create_tmp_var_name ("C");
2643 walk_tree (&DECL_INITIAL (object), force_labels_r, NULL, NULL);
2645 /* ??? C++ doesn't automatically append a .<number> to the
2646 assembler name, and even when it does, it looks a FE private
2647 data structures to figure out what that number should be,
2648 which are not set for this variable. I suppose this is
2649 important for local statics for inline functions, which aren't
2650 "local" in the object file sense. So in order to get a unique
2651 TU-local symbol, we must invoke the lhd version now. */
2652 lhd_set_decl_assembler_name (object);
2654 *expr_p = NULL_TREE;
2658 /* If there are "lots" of initialized elements, and all of them
2659 are valid address constants, then the entire initializer can
2660 be dropped to memory, and then memcpy'd out. */
2661 if (num_nonconstant_elements == 0)
2663 HOST_WIDE_INT size = int_size_in_bytes (type);
2666 /* ??? We can still get unbounded array types, at least
2667 from the C++ front end. This seems wrong, but attempt
2668 to work around it for now. */
2671 size = int_size_in_bytes (TREE_TYPE (object));
2673 TREE_TYPE (ctor) = type = TREE_TYPE (object);
2676 /* Find the maximum alignment we can assume for the object. */
2677 /* ??? Make use of DECL_OFFSET_ALIGN. */
2678 if (DECL_P (object))
2679 align = DECL_ALIGN (object);
2681 align = TYPE_ALIGN (type);
2683 if (size > 0 && !can_move_by_pieces (size, align))
2685 tree new = create_tmp_var_raw (type, "C");
2687 gimple_add_tmp_var (new);
2688 TREE_STATIC (new) = 1;
2689 TREE_READONLY (new) = 1;
2690 DECL_INITIAL (new) = ctor;
2691 if (align > DECL_ALIGN (new))
2693 DECL_ALIGN (new) = align;
2694 DECL_USER_ALIGN (new) = 1;
2696 walk_tree (&DECL_INITIAL (new), force_labels_r, NULL, NULL);
2698 TREE_OPERAND (*expr_p, 1) = new;
2700 /* This is no longer an assignment of a CONSTRUCTOR, but
2701 we still may have processing to do on the LHS. So
2702 pretend we didn't do anything here to let that happen. */
2703 return GS_UNHANDLED;
2707 /* If there are "lots" of initialized elements, even discounting
2708 those that are not address constants (and thus *must* be
2709 computed at runtime), then partition the constructor into
2710 constant and non-constant parts. Block copy the constant
2711 parts in, then generate code for the non-constant parts. */
2712 /* TODO. There's code in cp/typeck.c to do this. */
2714 num_type_elements = count_type_elements (type);
2716 /* If count_type_elements could not determine number of type elements
2717 for a constant-sized object, assume clearing is needed.
2718 Don't do this for variable-sized objects, as store_constructor
2719 will ignore the clearing of variable-sized objects. */
2720 if (num_type_elements < 0 && int_size_in_bytes (type) >= 0)
2722 /* If there are "lots" of zeros, then block clear the object first. */
2723 else if (num_type_elements - num_nonzero_elements > CLEAR_RATIO
2724 && num_nonzero_elements < num_type_elements/4)
2726 /* ??? This bit ought not be needed. For any element not present
2727 in the initializer, we should simply set them to zero. Except
2728 we'd need to *find* the elements that are not present, and that
2729 requires trickery to avoid quadratic compile-time behavior in
2730 large cases or excessive memory use in small cases. */
2731 else if (num_ctor_elements < num_type_elements)
2736 /* Zap the CONSTRUCTOR element list, which simplifies this case.
2737 Note that we still have to gimplify, in order to handle the
2738 case of variable sized types. Avoid shared tree structures. */
2739 CONSTRUCTOR_ELTS (ctor) = NULL_TREE;
2740 object = unshare_expr (object);
2741 gimplify_stmt (expr_p);
2742 append_to_statement_list (*expr_p, pre_p);
2745 /* If we have not block cleared the object, or if there are nonzero
2746 elements in the constructor, add assignments to the individual
2747 scalar fields of the object. */
2748 if (!cleared || num_nonzero_elements > 0)
2750 preeval_data.lhs_base_decl = get_base_address (object);
2751 if (!DECL_P (preeval_data.lhs_base_decl))
2752 preeval_data.lhs_base_decl = NULL;
2753 preeval_data.lhs_alias_set = get_alias_set (object);
2755 gimplify_init_ctor_preeval (&TREE_OPERAND (*expr_p, 1),
2756 pre_p, post_p, &preeval_data);
2757 gimplify_init_ctor_eval (object, elt_list, pre_p, cleared);
2760 *expr_p = NULL_TREE;
2768 /* Extract the real and imaginary parts out of the ctor. */
2772 r = TREE_VALUE (elt_list);
2773 elt_list = TREE_CHAIN (elt_list);
2776 i = TREE_VALUE (elt_list);
2777 gcc_assert (!TREE_CHAIN (elt_list));
2780 if (r == NULL || i == NULL)
2782 tree zero = convert (TREE_TYPE (type), integer_zero_node);
2789 /* Complex types have either COMPLEX_CST or COMPLEX_EXPR to
2790 represent creation of a complex value. */
2791 if (TREE_CONSTANT (r) && TREE_CONSTANT (i))
2793 ctor = build_complex (type, r, i);
2794 TREE_OPERAND (*expr_p, 1) = ctor;
2798 ctor = build (COMPLEX_EXPR, type, r, i);
2799 TREE_OPERAND (*expr_p, 1) = ctor;
2800 ret = gimplify_expr (&TREE_OPERAND (*expr_p, 1), pre_p, post_p,
2801 rhs_predicate_for (TREE_OPERAND (*expr_p, 0)),
2808 /* Go ahead and simplify constant constructors to VECTOR_CST. */
2809 if (TREE_CONSTANT (ctor))
2813 /* Even when ctor is constant, it might contain non-*_CST
2814 elements (e.g. { 1.0/0.0 - 1.0/0.0, 0.0 }) and those don't
2815 belong into VECTOR_CST nodes. */
2816 for (tem = elt_list; tem; tem = TREE_CHAIN (tem))
2817 if (! CONSTANT_CLASS_P (TREE_VALUE (tem)))
2822 TREE_OPERAND (*expr_p, 1) = build_vector (type, elt_list);
2827 /* Vector types use CONSTRUCTOR all the way through gimple
2828 compilation as a general initializer. */
2829 for (; elt_list; elt_list = TREE_CHAIN (elt_list))
2831 enum gimplify_status tret;
2832 tret = gimplify_expr (&TREE_VALUE (elt_list), pre_p, post_p,
2833 is_gimple_val, fb_rvalue);
2834 if (tret == GS_ERROR)
2840 /* So how did we get a CONSTRUCTOR for a scalar type? */
2844 if (ret == GS_ERROR)
2846 else if (want_value)
2848 append_to_statement_list (*expr_p, pre_p);
2856 /* Subroutine of gimplify_modify_expr to do simplifications of MODIFY_EXPRs
2857 based on the code of the RHS. We loop for as long as something changes. */
2859 static enum gimplify_status
2860 gimplify_modify_expr_rhs (tree *expr_p, tree *from_p, tree *to_p, tree *pre_p,
2861 tree *post_p, bool want_value)
2863 enum gimplify_status ret = GS_OK;
2865 while (ret != GS_UNHANDLED)
2866 switch (TREE_CODE (*from_p))
2870 /* If we have code like
2874 where the type of "x" is a (possibly cv-qualified variant
2875 of "A"), treat the entire expression as identical to "x".
2876 This kind of code arises in C++ when an object is bound
2877 to a const reference, and if "x" is a TARGET_EXPR we want
2878 to take advantage of the optimization below. */
2879 tree t = fold_indirect_ref (*from_p);
2892 /* If we are initializing something from a TARGET_EXPR, strip the
2893 TARGET_EXPR and initialize it directly, if possible. This can't
2894 be done if the initializer is void, since that implies that the
2895 temporary is set in some non-trivial way.
2897 ??? What about code that pulls out the temp and uses it
2898 elsewhere? I think that such code never uses the TARGET_EXPR as
2899 an initializer. If I'm wrong, we'll abort because the temp won't
2900 have any RTL. In that case, I guess we'll need to replace
2901 references somehow. */
2902 tree init = TARGET_EXPR_INITIAL (*from_p);
2904 if (!VOID_TYPE_P (TREE_TYPE (init)))
2915 /* Remove any COMPOUND_EXPR in the RHS so the following cases will be
2917 gimplify_compound_expr (from_p, pre_p, true);
2922 /* If we're initializing from a CONSTRUCTOR, break this into
2923 individual MODIFY_EXPRs. */
2924 return gimplify_init_constructor (expr_p, pre_p, post_p, want_value);
2927 /* If we're assigning to a non-register type, push the assignment
2928 down into the branches. This is mandatory for ADDRESSABLE types,
2929 since we cannot generate temporaries for such, but it saves a
2930 copy in other cases as well. */
2931 if (!is_gimple_reg_type (TREE_TYPE (*from_p)))
2934 return gimplify_cond_expr (expr_p, pre_p, post_p, *to_p,
2949 /* Gimplify the MODIFY_EXPR node pointed by EXPR_P.
2955 PRE_P points to the list where side effects that must happen before
2956 *EXPR_P should be stored.
2958 POST_P points to the list where side effects that must happen after
2959 *EXPR_P should be stored.
2961 WANT_VALUE is nonzero iff we want to use the value of this expression
2962 in another expression. */
2964 static enum gimplify_status
2965 gimplify_modify_expr (tree *expr_p, tree *pre_p, tree *post_p, bool want_value)
2967 tree *from_p = &TREE_OPERAND (*expr_p, 1);
2968 tree *to_p = &TREE_OPERAND (*expr_p, 0);
2969 enum gimplify_status ret = GS_UNHANDLED;
2971 gcc_assert (TREE_CODE (*expr_p) == MODIFY_EXPR
2972 || TREE_CODE (*expr_p) == INIT_EXPR);
2974 /* The distinction between MODIFY_EXPR and INIT_EXPR is no longer useful. */
2975 if (TREE_CODE (*expr_p) == INIT_EXPR)
2976 TREE_SET_CODE (*expr_p, MODIFY_EXPR);
2978 /* See if any simplifications can be done based on what the RHS is. */
2979 ret = gimplify_modify_expr_rhs (expr_p, from_p, to_p, pre_p, post_p,
2981 if (ret != GS_UNHANDLED)
2984 /* If the value being copied is of variable width, compute the length
2985 of the copy into a WITH_SIZE_EXPR. Note that we need to do this
2986 before gimplifying any of the operands so that we can resolve any
2987 PLACEHOLDER_EXPRs in the size. Also note that the RTL expander uses
2988 the size of the expression to be copied, not of the destination, so
2989 that is what we must here. */
2990 maybe_with_size_expr (from_p);
2992 ret = gimplify_expr (to_p, pre_p, post_p, is_gimple_lvalue, fb_lvalue);
2993 if (ret == GS_ERROR)
2996 ret = gimplify_expr (from_p, pre_p, post_p,
2997 rhs_predicate_for (*to_p), fb_rvalue);
2998 if (ret == GS_ERROR)
3001 /* Now see if the above changed *from_p to something we handle specially. */
3002 ret = gimplify_modify_expr_rhs (expr_p, from_p, to_p, pre_p, post_p,
3004 if (ret != GS_UNHANDLED)
3007 /* If we've got a variable sized assignment between two lvalues (i.e. does
3008 not involve a call), then we can make things a bit more straightforward
3009 by converting the assignment to memcpy or memset. */
3010 if (TREE_CODE (*from_p) == WITH_SIZE_EXPR)
3012 tree from = TREE_OPERAND (*from_p, 0);
3013 tree size = TREE_OPERAND (*from_p, 1);
3015 if (TREE_CODE (from) == CONSTRUCTOR)
3016 return gimplify_modify_expr_to_memset (expr_p, size, want_value);
3017 if (is_gimple_addressable (from))
3020 return gimplify_modify_expr_to_memcpy (expr_p, size, want_value);
3024 if (gimplify_ctxp->into_ssa && is_gimple_reg (*to_p))
3026 /* If we've somehow already got an SSA_NAME on the LHS, then
3027 we're probably modifying it twice. Not good. */
3028 gcc_assert (TREE_CODE (*to_p) != SSA_NAME);
3029 *to_p = make_ssa_name (*to_p, *expr_p);
3034 append_to_statement_list (*expr_p, pre_p);
3042 /* Gimplify a comparison between two variable-sized objects. Do this
3043 with a call to BUILT_IN_MEMCMP. */
3045 static enum gimplify_status
3046 gimplify_variable_sized_compare (tree *expr_p)
3048 tree op0 = TREE_OPERAND (*expr_p, 0);
3049 tree op1 = TREE_OPERAND (*expr_p, 1);
3052 t = TYPE_SIZE_UNIT (TREE_TYPE (op0));
3053 t = unshare_expr (t);
3054 t = SUBSTITUTE_PLACEHOLDER_IN_EXPR (t, op0);
3055 args = tree_cons (NULL, t, NULL);
3056 t = build_fold_addr_expr (op1);
3057 args = tree_cons (NULL, t, args);
3058 dest = build_fold_addr_expr (op0);
3059 args = tree_cons (NULL, dest, args);
3060 t = implicit_built_in_decls[BUILT_IN_MEMCMP];
3061 t = build_function_call_expr (t, args);
3063 = build (TREE_CODE (*expr_p), TREE_TYPE (*expr_p), t, integer_zero_node);
3068 /* Gimplify TRUTH_ANDIF_EXPR and TRUTH_ORIF_EXPR expressions. EXPR_P
3069 points to the expression to gimplify.
3071 Expressions of the form 'a && b' are gimplified to:
3073 a && b ? true : false
3075 gimplify_cond_expr will do the rest.
3077 PRE_P points to the list where side effects that must happen before
3078 *EXPR_P should be stored. */
3080 static enum gimplify_status
3081 gimplify_boolean_expr (tree *expr_p)
3083 /* Preserve the original type of the expression. */
3084 tree type = TREE_TYPE (*expr_p);
3086 *expr_p = build (COND_EXPR, type, *expr_p,
3087 convert (type, boolean_true_node),
3088 convert (type, boolean_false_node));
3093 /* Gimplifies an expression sequence. This function gimplifies each
3094 expression and re-writes the original expression with the last
3095 expression of the sequence in GIMPLE form.
3097 PRE_P points to the list where the side effects for all the
3098 expressions in the sequence will be emitted.
3100 WANT_VALUE is true when the result of the last COMPOUND_EXPR is used. */
3101 /* ??? Should rearrange to share the pre-queue with all the indirect
3102 invocations of gimplify_expr. Would probably save on creations
3103 of statement_list nodes. */
3105 static enum gimplify_status
3106 gimplify_compound_expr (tree *expr_p, tree *pre_p, bool want_value)
3112 tree *sub_p = &TREE_OPERAND (t, 0);
3114 if (TREE_CODE (*sub_p) == COMPOUND_EXPR)
3115 gimplify_compound_expr (sub_p, pre_p, false);
3117 gimplify_stmt (sub_p);
3118 append_to_statement_list (*sub_p, pre_p);
3120 t = TREE_OPERAND (t, 1);
3122 while (TREE_CODE (t) == COMPOUND_EXPR);
3129 gimplify_stmt (expr_p);
3134 /* Gimplifies a statement list. These may be created either by an
3135 enlightened front-end, or by shortcut_cond_expr. */
3137 static enum gimplify_status
3138 gimplify_statement_list (tree *expr_p)
3140 tree_stmt_iterator i = tsi_start (*expr_p);
3142 while (!tsi_end_p (i))
3146 gimplify_stmt (tsi_stmt_ptr (i));
3151 else if (TREE_CODE (t) == STATEMENT_LIST)
3153 tsi_link_before (&i, t, TSI_SAME_STMT);
3163 /* Gimplify a SAVE_EXPR node. EXPR_P points to the expression to
3164 gimplify. After gimplification, EXPR_P will point to a new temporary
3165 that holds the original value of the SAVE_EXPR node.
3167 PRE_P points to the list where side effects that must happen before
3168 *EXPR_P should be stored. */
3170 static enum gimplify_status
3171 gimplify_save_expr (tree *expr_p, tree *pre_p, tree *post_p)
3173 enum gimplify_status ret = GS_ALL_DONE;
3176 gcc_assert (TREE_CODE (*expr_p) == SAVE_EXPR);
3177 val = TREE_OPERAND (*expr_p, 0);
3179 /* If the SAVE_EXPR has not been resolved, then evaluate it once. */
3180 if (!SAVE_EXPR_RESOLVED_P (*expr_p))
3182 /* The operand may be a void-valued expression such as SAVE_EXPRs
3183 generated by the Java frontend for class initialization. It is
3184 being executed only for its side-effects. */
3185 if (TREE_TYPE (val) == void_type_node)
3187 ret = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p, post_p,
3188 is_gimple_stmt, fb_none);
3189 append_to_statement_list (TREE_OPERAND (*expr_p, 0), pre_p);
3193 val = get_initialized_tmp_var (val, pre_p, post_p);
3195 TREE_OPERAND (*expr_p, 0) = val;
3196 SAVE_EXPR_RESOLVED_P (*expr_p) = 1;
3204 /* Re-write the ADDR_EXPR node pointed by EXPR_P
3211 PRE_P points to the list where side effects that must happen before
3212 *EXPR_P should be stored.
3214 POST_P points to the list where side effects that must happen after
3215 *EXPR_P should be stored. */
3217 static enum gimplify_status
3218 gimplify_addr_expr (tree *expr_p, tree *pre_p, tree *post_p)
3220 tree expr = *expr_p;
3221 tree op0 = TREE_OPERAND (expr, 0);
3222 enum gimplify_status ret;
3224 switch (TREE_CODE (op0))
3227 case MISALIGNED_INDIRECT_REF:
3229 /* Check if we are dealing with an expression of the form '&*ptr'.
3230 While the front end folds away '&*ptr' into 'ptr', these
3231 expressions may be generated internally by the compiler (e.g.,
3232 builtins like __builtin_va_end). */
3233 /* Caution: the silent array decomposition semantics we allow for
3234 ADDR_EXPR means we can't always discard the pair. */
3235 /* Gimplification of the ADDR_EXPR operand may drop
3236 cv-qualification conversions, so make sure we add them if
3239 tree op00 = TREE_OPERAND (op0, 0);
3240 tree t_expr = TREE_TYPE (expr);
3241 tree t_op00 = TREE_TYPE (op00);
3243 if (!lang_hooks.types_compatible_p (t_expr, t_op00))
3245 #ifdef ENABLE_CHECKING
3246 tree t_op0 = TREE_TYPE (op0);
3247 gcc_assert (POINTER_TYPE_P (t_expr)
3248 && cpt_same_type (TREE_CODE (t_op0) == ARRAY_TYPE
3249 ? TREE_TYPE (t_op0) : t_op0,
3251 && POINTER_TYPE_P (t_op00)
3252 && cpt_same_type (t_op0, TREE_TYPE (t_op00)));
3254 op00 = fold_convert (TREE_TYPE (expr), op00);
3261 case VIEW_CONVERT_EXPR:
3262 /* Take the address of our operand and then convert it to the type of
3265 ??? The interactions of VIEW_CONVERT_EXPR and aliasing is not at
3266 all clear. The impact of this transformation is even less clear. */
3268 /* If the operand is a useless conversion, look through it. Doing so
3269 guarantees that the ADDR_EXPR and its operand will remain of the
3271 if (tree_ssa_useless_type_conversion (TREE_OPERAND (op0, 0)))
3272 op0 = TREE_OPERAND (op0, 0);
3274 *expr_p = fold_convert (TREE_TYPE (expr),
3275 build_fold_addr_expr (TREE_OPERAND (op0, 0)));
3280 /* We use fb_either here because the C frontend sometimes takes
3281 the address of a call that returns a struct; see
3282 gcc.dg/c99-array-lval-1.c. The gimplifier will correctly make
3283 the implied temporary explicit. */
3284 ret = gimplify_expr (&TREE_OPERAND (expr, 0), pre_p, post_p,
3285 is_gimple_addressable, fb_either);
3286 if (ret != GS_ERROR)
3288 op0 = TREE_OPERAND (expr, 0);
3290 /* For various reasons, the gimplification of the expression
3291 may have made a new INDIRECT_REF. */
3292 if (TREE_CODE (op0) == INDIRECT_REF)
3293 goto do_indirect_ref;
3295 /* Make sure TREE_INVARIANT, TREE_CONSTANT, and TREE_SIDE_EFFECTS
3297 recompute_tree_invarant_for_addr_expr (expr);
3299 /* Mark the RHS addressable. */
3300 lang_hooks.mark_addressable (TREE_OPERAND (expr, 0));
3308 /* Gimplify the operands of an ASM_EXPR. Input operands should be a gimple
3309 value; output operands should be a gimple lvalue. */
3311 static enum gimplify_status
3312 gimplify_asm_expr (tree *expr_p, tree *pre_p, tree *post_p)
3314 tree expr = *expr_p;
3315 int noutputs = list_length (ASM_OUTPUTS (expr));
3316 const char **oconstraints
3317 = (const char **) alloca ((noutputs) * sizeof (const char *));
3320 const char *constraint;
3321 bool allows_mem, allows_reg, is_inout;
3322 enum gimplify_status ret, tret;
3325 for (i = 0, link = ASM_OUTPUTS (expr); link; ++i, link = TREE_CHAIN (link))
3327 size_t constraint_len;
3328 oconstraints[i] = constraint
3329 = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (link)));
3330 constraint_len = strlen (constraint);
3331 if (constraint_len == 0)
3334 parse_output_constraint (&constraint, i, 0, 0,
3335 &allows_mem, &allows_reg, &is_inout);
3337 if (!allows_reg && allows_mem)
3338 lang_hooks.mark_addressable (TREE_VALUE (link));
3340 tret = gimplify_expr (&TREE_VALUE (link), pre_p, post_p,
3341 is_inout ? is_gimple_min_lval : is_gimple_lvalue,
3342 fb_lvalue | fb_mayfail);
3343 if (tret == GS_ERROR)
3345 error ("invalid lvalue in asm output %d", i);
3351 /* An input/output operand. To give the optimizers more
3352 flexibility, split it into separate input and output
3357 /* Turn the in/out constraint into an output constraint. */
3358 char *p = xstrdup (constraint);
3360 TREE_VALUE (TREE_PURPOSE (link)) = build_string (constraint_len, p);
3362 /* And add a matching input constraint. */
3365 sprintf (buf, "%d", i);
3367 /* If there are multiple alternatives in the constraint,
3368 handle each of them individually. Those that allow register
3369 will be replaced with operand number, the others will stay
3371 if (strchr (p, ',') != NULL)
3373 size_t len = 0, buflen = strlen (buf);
3374 char *beg, *end, *str, *dst;
3378 end = strchr (beg, ',');
3380 end = strchr (beg, '\0');
3381 if ((size_t) (end - beg) < buflen)
3384 len += end - beg + 1;
3392 for (beg = p + 1, dst = str;;)
3395 bool mem_p, reg_p, inout_p;
3397 end = strchr (beg, ',');
3402 parse_output_constraint (&tem, i, 0, 0,
3403 &mem_p, ®_p, &inout_p);
3408 memcpy (dst, buf, buflen);
3417 memcpy (dst, beg, len);
3426 input = build_string (dst - str, str);
3429 input = build_string (strlen (buf), buf);
3432 input = build_string (constraint_len - 1, constraint + 1);
3436 input = build_tree_list (build_tree_list (NULL_TREE, input),
3437 unshare_expr (TREE_VALUE (link)));
3438 ASM_INPUTS (expr) = chainon (ASM_INPUTS (expr), input);
3442 for (link = ASM_INPUTS (expr); link; ++i, link = TREE_CHAIN (link))
3445 = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (link)));
3446 parse_input_constraint (&constraint, 0, 0, noutputs, 0,
3447 oconstraints, &allows_mem, &allows_reg);
3449 /* If the operand is a memory input, it should be an lvalue. */
3450 if (!allows_reg && allows_mem)
3452 lang_hooks.mark_addressable (TREE_VALUE (link));
3453 tret = gimplify_expr (&TREE_VALUE (link), pre_p, post_p,
3454 is_gimple_lvalue, fb_lvalue | fb_mayfail);
3455 if (tret == GS_ERROR)
3457 error ("memory input %d is not directly addressable", i);
3463 tret = gimplify_expr (&TREE_VALUE (link), pre_p, post_p,
3464 is_gimple_asm_val, fb_rvalue);
3465 if (tret == GS_ERROR)
3473 /* Gimplify a CLEANUP_POINT_EXPR. Currently this works by adding
3474 WITH_CLEANUP_EXPRs to the prequeue as we encounter cleanups while
3475 gimplifying the body, and converting them to TRY_FINALLY_EXPRs when we
3476 return to this function.
3478 FIXME should we complexify the prequeue handling instead? Or use flags
3479 for all the cleanups and let the optimizer tighten them up? The current
3480 code seems pretty fragile; it will break on a cleanup within any
3481 non-conditional nesting. But any such nesting would be broken, anyway;
3482 we can't write a TRY_FINALLY_EXPR that starts inside a nesting construct
3483 and continues out of it. We can do that at the RTL level, though, so
3484 having an optimizer to tighten up try/finally regions would be a Good
3487 static enum gimplify_status
3488 gimplify_cleanup_point_expr (tree *expr_p, tree *pre_p)
3490 tree_stmt_iterator iter;
3493 tree temp = voidify_wrapper_expr (*expr_p, NULL);
3495 /* We only care about the number of conditions between the innermost
3496 CLEANUP_POINT_EXPR and the cleanup. So save and reset the count. */
3497 int old_conds = gimplify_ctxp->conditions;
3498 gimplify_ctxp->conditions = 0;
3500 body = TREE_OPERAND (*expr_p, 0);
3501 gimplify_to_stmt_list (&body);
3503 gimplify_ctxp->conditions = old_conds;
3505 for (iter = tsi_start (body); !tsi_end_p (iter); )
3507 tree *wce_p = tsi_stmt_ptr (iter);
3510 if (TREE_CODE (wce) == WITH_CLEANUP_EXPR)
3512 if (tsi_one_before_end_p (iter))
3514 tsi_link_before (&iter, TREE_OPERAND (wce, 0), TSI_SAME_STMT);
3521 enum tree_code code;
3523 if (CLEANUP_EH_ONLY (wce))
3524 code = TRY_CATCH_EXPR;
3526 code = TRY_FINALLY_EXPR;
3528 sl = tsi_split_statement_list_after (&iter);
3529 tfe = build (code, void_type_node, sl, NULL_TREE);
3530 append_to_statement_list (TREE_OPERAND (wce, 0),
3531 &TREE_OPERAND (tfe, 1));
3533 iter = tsi_start (sl);
3543 append_to_statement_list (body, pre_p);
3553 /* Insert a cleanup marker for gimplify_cleanup_point_expr. CLEANUP
3554 is the cleanup action required. */
3557 gimple_push_cleanup (tree var, tree cleanup, bool eh_only, tree *pre_p)
3561 /* Errors can result in improperly nested cleanups. Which results in
3562 confusion when trying to resolve the WITH_CLEANUP_EXPR. */
3563 if (errorcount || sorrycount)
3566 if (gimple_conditional_context ())
3568 /* If we're in a conditional context, this is more complex. We only
3569 want to run the cleanup if we actually ran the initialization that
3570 necessitates it, but we want to run it after the end of the
3571 conditional context. So we wrap the try/finally around the
3572 condition and use a flag to determine whether or not to actually
3573 run the destructor. Thus
3577 becomes (approximately)
3581 if (test) { A::A(temp); flag = 1; val = f(temp); }
3584 if (flag) A::~A(temp);
3589 tree flag = create_tmp_var (boolean_type_node, "cleanup");
3590 tree ffalse = build (MODIFY_EXPR, void_type_node, flag,
3591 boolean_false_node);
3592 tree ftrue = build (MODIFY_EXPR, void_type_node, flag,
3594 cleanup = build (COND_EXPR, void_type_node, flag, cleanup, NULL);
3595 wce = build (WITH_CLEANUP_EXPR, void_type_node, cleanup);
3596 append_to_statement_list (ffalse, &gimplify_ctxp->conditional_cleanups);
3597 append_to_statement_list (wce, &gimplify_ctxp->conditional_cleanups);
3598 append_to_statement_list (ftrue, pre_p);
3600 /* Because of this manipulation, and the EH edges that jump
3601 threading cannot redirect, the temporary (VAR) will appear
3602 to be used uninitialized. Don't warn. */
3603 TREE_NO_WARNING (var) = 1;
3607 wce = build (WITH_CLEANUP_EXPR, void_type_node, cleanup);
3608 CLEANUP_EH_ONLY (wce) = eh_only;
3609 append_to_statement_list (wce, pre_p);
3612 gimplify_stmt (&TREE_OPERAND (wce, 0));
3615 /* Gimplify a TARGET_EXPR which doesn't appear on the rhs of an INIT_EXPR. */
3617 static enum gimplify_status
3618 gimplify_target_expr (tree *expr_p, tree *pre_p, tree *post_p)
3620 tree targ = *expr_p;
3621 tree temp = TARGET_EXPR_SLOT (targ);
3622 tree init = TARGET_EXPR_INITIAL (targ);
3623 enum gimplify_status ret;
3627 /* TARGET_EXPR temps aren't part of the enclosing block, so add it
3628 to the temps list. */
3629 gimple_add_tmp_var (temp);
3631 /* If TARGET_EXPR_INITIAL is void, then the mere evaluation of the
3632 expression is supposed to initialize the slot. */
3633 if (VOID_TYPE_P (TREE_TYPE (init)))
3634 ret = gimplify_expr (&init, pre_p, post_p, is_gimple_stmt, fb_none);
3637 /* Special handling for BIND_EXPR can result in fewer temps. */
3639 if (TREE_CODE (init) == BIND_EXPR)
3640 gimplify_bind_expr (&init, temp, pre_p);
3643 init = build (MODIFY_EXPR, void_type_node, temp, init);
3644 ret = gimplify_expr (&init, pre_p, post_p, is_gimple_stmt,
3648 if (ret == GS_ERROR)
3650 append_to_statement_list (init, pre_p);
3652 /* If needed, push the cleanup for the temp. */
3653 if (TARGET_EXPR_CLEANUP (targ))
3655 gimplify_stmt (&TARGET_EXPR_CLEANUP (targ));
3656 gimple_push_cleanup (temp, TARGET_EXPR_CLEANUP (targ),
3657 CLEANUP_EH_ONLY (targ), pre_p);
3660 /* Only expand this once. */
3661 TREE_OPERAND (targ, 3) = init;
3662 TARGET_EXPR_INITIAL (targ) = NULL_TREE;
3665 /* We should have expanded this before. */
3666 gcc_assert (DECL_SEEN_IN_BIND_EXPR_P (temp));
3672 /* Gimplification of expression trees. */
3674 /* Gimplify an expression which appears at statement context; usually, this
3675 means replacing it with a suitably gimple STATEMENT_LIST. */
3678 gimplify_stmt (tree *stmt_p)
3680 gimplify_expr (stmt_p, NULL, NULL, is_gimple_stmt, fb_none);
3683 /* Similarly, but force the result to be a STATEMENT_LIST. */
3686 gimplify_to_stmt_list (tree *stmt_p)
3688 gimplify_stmt (stmt_p);
3690 *stmt_p = alloc_stmt_list ();
3691 else if (TREE_CODE (*stmt_p) != STATEMENT_LIST)
3694 *stmt_p = alloc_stmt_list ();
3695 append_to_statement_list (t, stmt_p);
3700 /* Gimplifies the expression tree pointed by EXPR_P. Return 0 if
3701 gimplification failed.
3703 PRE_P points to the list where side effects that must happen before
3704 EXPR should be stored.
3706 POST_P points to the list where side effects that must happen after
3707 EXPR should be stored, or NULL if there is no suitable list. In
3708 that case, we copy the result to a temporary, emit the
3709 post-effects, and then return the temporary.
3711 GIMPLE_TEST_F points to a function that takes a tree T and
3712 returns nonzero if T is in the GIMPLE form requested by the
3713 caller. The GIMPLE predicates are in tree-gimple.c.
3715 This test is used twice. Before gimplification, the test is
3716 invoked to determine whether *EXPR_P is already gimple enough. If
3717 that fails, *EXPR_P is gimplified according to its code and
3718 GIMPLE_TEST_F is called again. If the test still fails, then a new
3719 temporary variable is created and assigned the value of the
3720 gimplified expression.
3722 FALLBACK tells the function what sort of a temporary we want. If the 1
3723 bit is set, an rvalue is OK. If the 2 bit is set, an lvalue is OK.
3724 If both are set, either is OK, but an lvalue is preferable.
3726 The return value is either GS_ERROR or GS_ALL_DONE, since this function
3727 iterates until solution. */
3729 enum gimplify_status
3730 gimplify_expr (tree *expr_p, tree *pre_p, tree *post_p,
3731 bool (* gimple_test_f) (tree), fallback_t fallback)
3734 tree internal_pre = NULL_TREE;
3735 tree internal_post = NULL_TREE;
3737 int is_statement = (pre_p == NULL);
3738 location_t saved_location;
3739 enum gimplify_status ret;
3741 save_expr = *expr_p;
3742 if (save_expr == NULL_TREE)
3745 /* We used to check the predicate here and return immediately if it
3746 succeeds. This is wrong; the design is for gimplification to be
3747 idempotent, and for the predicates to only test for valid forms, not
3748 whether they are fully simplified. */
3750 /* Set up our internal queues if needed. */
3752 pre_p = &internal_pre;
3754 post_p = &internal_post;
3756 saved_location = input_location;
3757 if (save_expr != error_mark_node
3758 && EXPR_HAS_LOCATION (*expr_p))
3759 input_location = EXPR_LOCATION (*expr_p);
3761 /* Loop over the specific gimplifiers until the toplevel node
3762 remains the same. */
3765 /* Strip away as many useless type conversions as possible
3767 STRIP_USELESS_TYPE_CONVERSION (*expr_p);
3769 /* Remember the expr. */
3770 save_expr = *expr_p;
3772 /* Die, die, die, my darling. */
3773 if (save_expr == error_mark_node
3774 || (TREE_TYPE (save_expr)
3775 && TREE_TYPE (save_expr) == error_mark_node))
3781 /* Do any language-specific gimplification. */
3782 ret = lang_hooks.gimplify_expr (expr_p, pre_p, post_p);
3785 if (*expr_p == NULL_TREE)
3787 if (*expr_p != save_expr)
3790 else if (ret != GS_UNHANDLED)
3794 switch (TREE_CODE (*expr_p))
3796 /* First deal with the special cases. */
3798 case POSTINCREMENT_EXPR:
3799 case POSTDECREMENT_EXPR:
3800 case PREINCREMENT_EXPR:
3801 case PREDECREMENT_EXPR:
3802 ret = gimplify_self_mod_expr (expr_p, pre_p, post_p,
3803 fallback != fb_none);
3807 case ARRAY_RANGE_REF:
3811 case VIEW_CONVERT_EXPR:
3812 ret = gimplify_compound_lval (expr_p, pre_p, post_p,
3813 fallback ? fallback : fb_rvalue);
3817 ret = gimplify_cond_expr (expr_p, pre_p, post_p, NULL_TREE,
3819 /* C99 code may assign to an array in a structure value of a
3820 conditional expression, and this has undefined behavior
3821 only on execution, so create a temporary if an lvalue is
3823 if (fallback == fb_lvalue)
3825 *expr_p = get_initialized_tmp_var (*expr_p, pre_p, post_p);
3826 lang_hooks.mark_addressable (*expr_p);
3831 ret = gimplify_call_expr (expr_p, pre_p, fallback != fb_none);
3832 /* C99 code may assign to an array in a structure returned
3833 from a function, and this has undefined behavior only on
3834 execution, so create a temporary if an lvalue is
3836 if (fallback == fb_lvalue)
3838 *expr_p = get_initialized_tmp_var (*expr_p, pre_p, post_p);
3839 lang_hooks.mark_addressable (*expr_p);
3847 ret = gimplify_compound_expr (expr_p, pre_p, fallback != fb_none);
3852 ret = gimplify_modify_expr (expr_p, pre_p, post_p,
3853 fallback != fb_none);
3856 case TRUTH_ANDIF_EXPR:
3857 case TRUTH_ORIF_EXPR:
3858 ret = gimplify_boolean_expr (expr_p);
3861 case TRUTH_NOT_EXPR:
3862 TREE_OPERAND (*expr_p, 0)
3863 = gimple_boolify (TREE_OPERAND (*expr_p, 0));
3864 ret = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p, post_p,
3865 is_gimple_val, fb_rvalue);
3866 recalculate_side_effects (*expr_p);
3870 ret = gimplify_addr_expr (expr_p, pre_p, post_p);
3874 ret = gimplify_va_arg_expr (expr_p, pre_p, post_p);
3879 if (IS_EMPTY_STMT (*expr_p))
3885 if (VOID_TYPE_P (TREE_TYPE (*expr_p))
3886 || fallback == fb_none)
3888 /* Just strip a conversion to void (or in void context) and
3890 *expr_p = TREE_OPERAND (*expr_p, 0);
3894 ret = gimplify_conversion (expr_p);
3895 if (ret == GS_ERROR)
3897 if (*expr_p != save_expr)
3901 case FIX_TRUNC_EXPR:
3903 case FIX_FLOOR_EXPR:
3904 case FIX_ROUND_EXPR:
3905 /* unary_expr: ... | '(' cast ')' val | ... */
3906 ret = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p, post_p,
3907 is_gimple_val, fb_rvalue);
3908 recalculate_side_effects (*expr_p);
3912 *expr_p = fold_indirect_ref (*expr_p);
3913 if (*expr_p != save_expr)
3915 /* else fall through. */
3916 case ALIGN_INDIRECT_REF:
3917 case MISALIGNED_INDIRECT_REF:
3918 ret = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p, post_p,
3919 is_gimple_reg, fb_rvalue);
3920 recalculate_side_effects (*expr_p);
3923 /* Constants need not be gimplified. */
3933 /* If we require an lvalue, such as for ADDR_EXPR, retain the
3934 CONST_DECL node. Otherwise the decl is replaceable by its
3936 /* ??? Should be == fb_lvalue, but ADDR_EXPR passes fb_either. */
3937 if (fallback & fb_lvalue)
3940 *expr_p = DECL_INITIAL (*expr_p);
3944 ret = gimplify_decl_expr (expr_p);
3948 /* FIXME make this a decl. */
3953 ret = gimplify_bind_expr (expr_p, NULL, pre_p);
3957 ret = gimplify_loop_expr (expr_p, pre_p);
3961 ret = gimplify_switch_expr (expr_p, pre_p);
3965 ret = gimplify_exit_expr (expr_p);
3969 /* If the target is not LABEL, then it is a computed jump
3970 and the target needs to be gimplified. */
3971 if (TREE_CODE (GOTO_DESTINATION (*expr_p)) != LABEL_DECL)
3972 ret = gimplify_expr (&GOTO_DESTINATION (*expr_p), pre_p,
3973 NULL, is_gimple_val, fb_rvalue);
3978 gcc_assert (decl_function_context (LABEL_EXPR_LABEL (*expr_p))
3979 == current_function_decl);
3982 case CASE_LABEL_EXPR:
3983 ret = gimplify_case_label_expr (expr_p);
3987 ret = gimplify_return_expr (*expr_p, pre_p);
3991 /* Don't reduce this in place; let gimplify_init_constructor work its
3992 magic. Buf if we're just elaborating this for side effects, just
3993 gimplify any element that has side-effects. */
3994 if (fallback == fb_none)
3996 for (tmp = CONSTRUCTOR_ELTS (*expr_p); tmp;
3997 tmp = TREE_CHAIN (tmp))
3998 if (TREE_SIDE_EFFECTS (TREE_VALUE (tmp)))
3999 gimplify_expr (&TREE_VALUE (tmp), pre_p, post_p,
4000 gimple_test_f, fallback);
4002 *expr_p = NULL_TREE;
4008 /* The following are special cases that are not handled by the
4009 original GIMPLE grammar. */
4011 /* SAVE_EXPR nodes are converted into a GIMPLE identifier and
4014 ret = gimplify_save_expr (expr_p, pre_p, post_p);
4019 enum gimplify_status r0, r1, r2;
4021 r0 = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p, post_p,
4022 is_gimple_lvalue, fb_either);
4023 r1 = gimplify_expr (&TREE_OPERAND (*expr_p, 1), pre_p, post_p,
4024 is_gimple_val, fb_rvalue);
4025 r2 = gimplify_expr (&TREE_OPERAND (*expr_p, 2), pre_p, post_p,
4026 is_gimple_val, fb_rvalue);
4027 recalculate_side_effects (*expr_p);
4029 ret = MIN (r0, MIN (r1, r2));
4033 case NON_LVALUE_EXPR:
4034 /* This should have been stripped above. */
4038 ret = gimplify_asm_expr (expr_p, pre_p, post_p);
4041 case TRY_FINALLY_EXPR:
4042 case TRY_CATCH_EXPR:
4043 gimplify_to_stmt_list (&TREE_OPERAND (*expr_p, 0));
4044 gimplify_to_stmt_list (&TREE_OPERAND (*expr_p, 1));
4048 case CLEANUP_POINT_EXPR:
4049 ret = gimplify_cleanup_point_expr (expr_p, pre_p);
4053 ret = gimplify_target_expr (expr_p, pre_p, post_p);
4057 gimplify_to_stmt_list (&CATCH_BODY (*expr_p));
4061 case EH_FILTER_EXPR:
4062 gimplify_to_stmt_list (&EH_FILTER_FAILURE (*expr_p));
4068 enum gimplify_status r0, r1;
4069 r0 = gimplify_expr (&OBJ_TYPE_REF_OBJECT (*expr_p), pre_p, post_p,
4070 is_gimple_val, fb_rvalue);
4071 r1 = gimplify_expr (&OBJ_TYPE_REF_EXPR (*expr_p), pre_p, post_p,
4072 is_gimple_val, fb_rvalue);
4078 /* We get here when taking the address of a label. We mark
4079 the label as "forced"; meaning it can never be removed and
4080 it is a potential target for any computed goto. */
4081 FORCED_LABEL (*expr_p) = 1;
4085 case STATEMENT_LIST:
4086 ret = gimplify_statement_list (expr_p);
4089 case WITH_SIZE_EXPR:
4091 enum gimplify_status r0, r1;
4092 r0 = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p,
4093 post_p == &internal_post ? NULL : post_p,
4094 gimple_test_f, fallback);
4095 r1 = gimplify_expr (&TREE_OPERAND (*expr_p, 1), pre_p, post_p,
4096 is_gimple_val, fb_rvalue);
4101 /* ??? If this is a local variable, and it has not been seen in any
4102 outer BIND_EXPR, then it's probably the result of a duplicate
4103 declaration, for which we've already issued an error. It would
4104 be really nice if the front end wouldn't leak these at all.
4105 Currently the only known culprit is C++ destructors, as seen
4106 in g++.old-deja/g++.jason/binding.C. */
4108 if (!TREE_STATIC (tmp) && !DECL_EXTERNAL (tmp)
4109 && decl_function_context (tmp) == current_function_decl
4110 && !DECL_SEEN_IN_BIND_EXPR_P (tmp))
4112 gcc_assert (errorcount || sorrycount);
4121 /* If this is a local variable sized decl, it must be accessed
4122 indirectly. Perform that substitution. */
4123 if (DECL_VALUE_EXPR (tmp))
4125 *expr_p = unshare_expr (DECL_VALUE_EXPR (tmp));
4134 /* Allow callbacks into the gimplifier during optimization. */
4139 switch (TREE_CODE_CLASS (TREE_CODE (*expr_p)))
4141 case tcc_comparison:
4142 /* If this is a comparison of objects of aggregate type,
4143 handle it specially (by converting to a call to
4144 memcmp). It would be nice to only have to do this
4145 for variable-sized objects, but then we'd have to
4146 allow the same nest of reference nodes we allow for
4147 MODIFY_EXPR and that's too complex. */
4148 if (!AGGREGATE_TYPE_P (TREE_TYPE (TREE_OPERAND (*expr_p, 1))))
4150 ret = gimplify_variable_sized_compare (expr_p);
4153 /* If *EXPR_P does not need to be special-cased, handle it
4154 according to its class. */
4156 ret = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p,
4157 post_p, is_gimple_val, fb_rvalue);
4163 enum gimplify_status r0, r1;
4165 r0 = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p,
4166 post_p, is_gimple_val, fb_rvalue);
4167 r1 = gimplify_expr (&TREE_OPERAND (*expr_p, 1), pre_p,
4168 post_p, is_gimple_val, fb_rvalue);
4174 case tcc_declaration:
4177 goto dont_recalculate;
4180 gcc_assert (TREE_CODE (*expr_p) == TRUTH_AND_EXPR
4181 || TREE_CODE (*expr_p) == TRUTH_OR_EXPR
4182 || TREE_CODE (*expr_p) == TRUTH_XOR_EXPR);
4186 recalculate_side_effects (*expr_p);
4191 /* If we replaced *expr_p, gimplify again. */
4192 if (ret == GS_OK && (*expr_p == NULL || *expr_p == save_expr))
4195 while (ret == GS_OK);
4197 /* If we encountered an error_mark somewhere nested inside, either
4198 stub out the statement or propagate the error back out. */
4199 if (ret == GS_ERROR)
4206 /* This was only valid as a return value from the langhook, which
4207 we handled. Make sure it doesn't escape from any other context. */
4208 gcc_assert (ret != GS_UNHANDLED);
4210 if (fallback == fb_none && *expr_p && !is_gimple_stmt (*expr_p))
4212 /* We aren't looking for a value, and we don't have a valid
4213 statement. If it doesn't have side-effects, throw it away. */
4214 if (!TREE_SIDE_EFFECTS (*expr_p))
4216 else if (!TREE_THIS_VOLATILE (*expr_p))
4218 /* This is probably a _REF that contains something nested that
4219 has side effects. Recurse through the operands to find it. */
4220 enum tree_code code = TREE_CODE (*expr_p);
4225 case REALPART_EXPR: case IMAGPART_EXPR:
4226 gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p, post_p,
4227 gimple_test_f, fallback);
4230 case ARRAY_REF: case ARRAY_RANGE_REF:
4231 gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p, post_p,
4232 gimple_test_f, fallback);
4233 gimplify_expr (&TREE_OPERAND (*expr_p, 1), pre_p, post_p,
4234 gimple_test_f, fallback);
4238 /* Anything else with side-effects must be converted to
4239 a valid statement before we get here. */
4245 else if (COMPLETE_TYPE_P (TREE_TYPE (*expr_p)))
4247 /* Historically, the compiler has treated a bare
4248 reference to a volatile lvalue as forcing a load. */
4249 tree tmp = create_tmp_var (TREE_TYPE (*expr_p), "vol");
4250 *expr_p = build (MODIFY_EXPR, TREE_TYPE (tmp), tmp, *expr_p);
4253 /* We can't do anything useful with a volatile reference to
4254 incomplete type, so just throw it away. */
4258 /* If we are gimplifying at the statement level, we're done. Tack
4259 everything together and replace the original statement with the
4261 if (fallback == fb_none || is_statement)
4263 if (internal_pre || internal_post)
4265 append_to_statement_list (*expr_p, &internal_pre);
4266 append_to_statement_list (internal_post, &internal_pre);
4267 annotate_all_with_locus (&internal_pre, input_location);
4268 *expr_p = internal_pre;
4272 else if (TREE_CODE (*expr_p) == STATEMENT_LIST)
4273 annotate_all_with_locus (expr_p, input_location);
4275 annotate_one_with_locus (*expr_p, input_location);
4279 /* Otherwise we're gimplifying a subexpression, so the resulting value is
4282 /* If it's sufficiently simple already, we're done. Unless we are
4283 handling some post-effects internally; if that's the case, we need to
4284 copy into a temp before adding the post-effects to the tree. */
4285 if (!internal_post && (*gimple_test_f) (*expr_p))
4288 /* Otherwise, we need to create a new temporary for the gimplified
4291 /* We can't return an lvalue if we have an internal postqueue. The
4292 object the lvalue refers to would (probably) be modified by the
4293 postqueue; we need to copy the value out first, which means an
4295 if ((fallback & fb_lvalue) && !internal_post
4296 && is_gimple_addressable (*expr_p))
4298 /* An lvalue will do. Take the address of the expression, store it
4299 in a temporary, and replace the expression with an INDIRECT_REF of
4301 tmp = build_fold_addr_expr (*expr_p);
4302 gimplify_expr (&tmp, pre_p, post_p, is_gimple_reg, fb_rvalue);
4303 *expr_p = build1 (INDIRECT_REF, TREE_TYPE (TREE_TYPE (tmp)), tmp);
4305 else if ((fallback & fb_rvalue) && is_gimple_formal_tmp_rhs (*expr_p))
4307 gcc_assert (!VOID_TYPE_P (TREE_TYPE (*expr_p)));
4309 /* An rvalue will do. Assign the gimplified expression into a new
4310 temporary TMP and replace the original expression with TMP. */
4312 if (internal_post || (fallback & fb_lvalue))
4313 /* The postqueue might change the value of the expression between
4314 the initialization and use of the temporary, so we can't use a
4315 formal temp. FIXME do we care? */
4316 *expr_p = get_initialized_tmp_var (*expr_p, pre_p, post_p);
4318 *expr_p = get_formal_tmp_var (*expr_p, pre_p);
4320 if (TREE_CODE (*expr_p) != SSA_NAME)
4321 DECL_GIMPLE_FORMAL_TEMP_P (*expr_p) = 1;
4325 #ifdef ENABLE_CHECKING
4326 if (!(fallback & fb_mayfail))
4328 fprintf (stderr, "gimplification failed:\n");
4329 print_generic_expr (stderr, *expr_p, 0);
4330 debug_tree (*expr_p);
4331 internal_error ("gimplification failed");
4334 gcc_assert (fallback & fb_mayfail);
4335 /* If this is an asm statement, and the user asked for the
4336 impossible, don't abort. Fail and let gimplify_asm_expr
4342 /* Make sure the temporary matches our predicate. */
4343 gcc_assert ((*gimple_test_f) (*expr_p));
4347 annotate_all_with_locus (&internal_post, input_location);
4348 append_to_statement_list (internal_post, pre_p);
4352 input_location = saved_location;
4356 /* Look through TYPE for variable-sized objects and gimplify each such
4357 size that we find. Add to LIST_P any statements generated. */
4360 gimplify_type_sizes (tree type, tree *list_p)
4367 /* We first do the main variant, then copy into any other variants. */
4368 type = TYPE_MAIN_VARIANT (type);
4370 /* Avoid infinite recursion. */
4371 if (TYPE_SIZES_GIMPLIFIED (type)
4372 || type == error_mark_node)
4375 TYPE_SIZES_GIMPLIFIED (type) = 1;
4377 switch (TREE_CODE (type))
4384 gimplify_one_sizepos (&TYPE_MIN_VALUE (type), list_p);
4385 gimplify_one_sizepos (&TYPE_MAX_VALUE (type), list_p);
4387 for (t = TYPE_NEXT_VARIANT (type); t; t = TYPE_NEXT_VARIANT (t))
4389 TYPE_MIN_VALUE (t) = TYPE_MIN_VALUE (type);
4390 TYPE_MAX_VALUE (t) = TYPE_MAX_VALUE (type);
4395 /* These types may not have declarations, so handle them here. */
4396 gimplify_type_sizes (TREE_TYPE (type), list_p);
4397 gimplify_type_sizes (TYPE_DOMAIN (type), list_p);
4402 case QUAL_UNION_TYPE:
4403 for (field = TYPE_FIELDS (type); field; field = TREE_CHAIN (field))
4404 if (TREE_CODE (field) == FIELD_DECL)
4406 gimplify_one_sizepos (&DECL_FIELD_OFFSET (field), list_p);
4407 gimplify_type_sizes (TREE_TYPE (field), list_p);
4412 case REFERENCE_TYPE:
4413 gimplify_type_sizes (TREE_TYPE (type), list_p);
4420 gimplify_one_sizepos (&TYPE_SIZE (type), list_p);
4421 gimplify_one_sizepos (&TYPE_SIZE_UNIT (type), list_p);
4423 for (t = TYPE_NEXT_VARIANT (type); t; t = TYPE_NEXT_VARIANT (t))
4425 TYPE_SIZE (t) = TYPE_SIZE (type);
4426 TYPE_SIZE_UNIT (t) = TYPE_SIZE_UNIT (type);
4427 TYPE_SIZES_GIMPLIFIED (t) = 1;
4431 /* A subroutine of gimplify_type_sizes to make sure that *EXPR_P,
4432 a size or position, has had all of its SAVE_EXPRs evaluated.
4433 We add any required statements to STMT_P. */
4436 gimplify_one_sizepos (tree *expr_p, tree *stmt_p)
4438 /* We don't do anything if the value isn't there, is constant, or contains
4439 A PLACEHOLDER_EXPR. We also don't want to do anything if it's already
4440 a VAR_DECL. If it's a VAR_DECL from another function, the gimplfier
4441 will want to replace it with a new variable, but that will cause problems
4442 if this type is from outside the function. It's OK to have that here. */
4443 if (*expr_p == NULL_TREE || TREE_CONSTANT (*expr_p)
4444 || TREE_CODE (*expr_p) == VAR_DECL
4445 || CONTAINS_PLACEHOLDER_P (*expr_p))
4448 *expr_p = unshare_expr (*expr_p);
4449 gimplify_expr (expr_p, stmt_p, NULL, is_gimple_val, fb_rvalue);
4452 #ifdef ENABLE_CHECKING
4453 /* Compare types A and B for a "close enough" match. */
4456 cpt_same_type (tree a, tree b)
4458 if (lang_hooks.types_compatible_p (a, b))
4461 /* ??? The C++ FE decomposes METHOD_TYPES to FUNCTION_TYPES and doesn't
4462 link them together. This routine is intended to catch type errors
4463 that will affect the optimizers, and the optimizers don't add new
4464 dereferences of function pointers, so ignore it. */
4465 if ((TREE_CODE (a) == FUNCTION_TYPE || TREE_CODE (a) == METHOD_TYPE)
4466 && (TREE_CODE (b) == FUNCTION_TYPE || TREE_CODE (b) == METHOD_TYPE))
4469 /* ??? The C FE pushes type qualifiers after the fact into the type of
4470 the element from the type of the array. See build_unary_op's handling
4471 of ADDR_EXPR. This seems wrong -- if we were going to do this, we
4472 should have done it when creating the variable in the first place.
4473 Alternately, why aren't the two array types made variants? */
4474 if (TREE_CODE (a) == ARRAY_TYPE && TREE_CODE (b) == ARRAY_TYPE)
4475 return cpt_same_type (TREE_TYPE (a), TREE_TYPE (b));
4477 /* And because of those, we have to recurse down through pointers. */
4478 if (POINTER_TYPE_P (a) && POINTER_TYPE_P (b))
4479 return cpt_same_type (TREE_TYPE (a), TREE_TYPE (b));
4484 /* Check for some cases of the front end missing cast expressions.
4485 The type of a dereference should correspond to the pointer type;
4486 similarly the type of an address should match its object. */
4489 check_pointer_types_r (tree *tp, int *walk_subtrees ATTRIBUTE_UNUSED,
4490 void *data ATTRIBUTE_UNUSED)
4493 tree ptype, otype, dtype;
4495 switch (TREE_CODE (t))
4499 otype = TREE_TYPE (t);
4500 ptype = TREE_TYPE (TREE_OPERAND (t, 0));
4501 dtype = TREE_TYPE (ptype);
4502 gcc_assert (cpt_same_type (otype, dtype));
4506 ptype = TREE_TYPE (t);
4507 otype = TREE_TYPE (TREE_OPERAND (t, 0));
4508 dtype = TREE_TYPE (ptype);
4509 if (!cpt_same_type (otype, dtype))
4511 /* &array is allowed to produce a pointer to the element, rather than
4512 a pointer to the array type. We must allow this in order to
4513 properly represent assigning the address of an array in C into
4514 pointer to the element type. */
4515 gcc_assert (TREE_CODE (otype) == ARRAY_TYPE
4516 && POINTER_TYPE_P (ptype)
4517 && cpt_same_type (TREE_TYPE (otype), dtype));
4531 /* Gimplify the body of statements pointed by BODY_P. FNDECL is the
4532 function decl containing BODY. */
4535 gimplify_body (tree *body_p, tree fndecl, bool do_parms)
4537 location_t saved_location = input_location;
4538 tree body, parm_stmts;
4540 timevar_push (TV_TREE_GIMPLIFY);
4541 push_gimplify_context ();
4543 /* Unshare most shared trees in the body and in that of any nested functions.
4544 It would seem we don't have to do this for nested functions because
4545 they are supposed to be output and then the outer function gimplified
4546 first, but the g++ front end doesn't always do it that way. */
4547 unshare_body (body_p, fndecl);
4548 unvisit_body (body_p, fndecl);
4550 /* Make sure input_location isn't set to something wierd. */
4551 input_location = DECL_SOURCE_LOCATION (fndecl);
4553 /* Resolve callee-copies. This has to be done before processing
4554 the body so that DECL_VALUE_EXPR gets processed correctly. */
4555 parm_stmts = do_parms ? gimplify_parameters () : NULL;
4557 /* Gimplify the function's body. */
4558 gimplify_stmt (body_p);
4562 body = alloc_stmt_list ();
4563 else if (TREE_CODE (body) == STATEMENT_LIST)
4565 tree t = expr_only (*body_p);
4570 /* If there isn't an outer BIND_EXPR, add one. */
4571 if (TREE_CODE (body) != BIND_EXPR)
4573 tree b = build (BIND_EXPR, void_type_node, NULL_TREE,
4574 NULL_TREE, NULL_TREE);
4575 TREE_SIDE_EFFECTS (b) = 1;
4576 append_to_statement_list_force (body, &BIND_EXPR_BODY (b));
4580 /* If we had callee-copies statements, insert them at the beginning
4584 append_to_statement_list_force (BIND_EXPR_BODY (body), &parm_stmts);
4585 BIND_EXPR_BODY (body) = parm_stmts;
4588 /* Unshare again, in case gimplification was sloppy. */
4589 unshare_all_trees (body);
4593 pop_gimplify_context (body);
4595 #ifdef ENABLE_CHECKING
4596 walk_tree (body_p, check_pointer_types_r, NULL, NULL);
4599 timevar_pop (TV_TREE_GIMPLIFY);
4600 input_location = saved_location;
4603 /* Entry point to the gimplification pass. FNDECL is the FUNCTION_DECL
4604 node for the function we want to gimplify. */
4607 gimplify_function_tree (tree fndecl)
4611 oldfn = current_function_decl;
4612 current_function_decl = fndecl;
4613 cfun = DECL_STRUCT_FUNCTION (fndecl);
4615 allocate_struct_function (fndecl);
4617 gimplify_body (&DECL_SAVED_TREE (fndecl), fndecl, true);
4619 /* If we're instrumenting function entry/exit, then prepend the call to
4620 the entry hook and wrap the whole function in a TRY_FINALLY_EXPR to
4621 catch the exit hook. */
4622 /* ??? Add some way to ignore exceptions for this TFE. */
4623 if (flag_instrument_function_entry_exit
4624 && ! DECL_NO_INSTRUMENT_FUNCTION_ENTRY_EXIT (fndecl))
4628 tf = build (TRY_FINALLY_EXPR, void_type_node, NULL, NULL);
4629 TREE_SIDE_EFFECTS (tf) = 1;
4630 x = DECL_SAVED_TREE (fndecl);
4631 append_to_statement_list (x, &TREE_OPERAND (tf, 0));
4632 x = implicit_built_in_decls[BUILT_IN_PROFILE_FUNC_EXIT];
4633 x = build_function_call_expr (x, NULL);
4634 append_to_statement_list (x, &TREE_OPERAND (tf, 1));
4636 bind = build (BIND_EXPR, void_type_node, NULL, NULL, NULL);
4637 TREE_SIDE_EFFECTS (bind) = 1;
4638 x = implicit_built_in_decls[BUILT_IN_PROFILE_FUNC_ENTER];
4639 x = build_function_call_expr (x, NULL);
4640 append_to_statement_list (x, &BIND_EXPR_BODY (bind));
4641 append_to_statement_list (tf, &BIND_EXPR_BODY (bind));
4643 DECL_SAVED_TREE (fndecl) = bind;
4646 current_function_decl = oldfn;
4647 cfun = oldfn ? DECL_STRUCT_FUNCTION (oldfn) : NULL;
4651 /* Expands EXPR to list of gimple statements STMTS. If SIMPLE is true,
4652 force the result to be either ssa_name or an invariant, otherwise
4653 just force it to be a rhs expression. If VAR is not NULL, make the
4654 base variable of the final destination be VAR if suitable. */
4657 force_gimple_operand (tree expr, tree *stmts, bool simple, tree var)
4660 enum gimplify_status ret;
4661 gimple_predicate gimple_test_f;
4665 if (is_gimple_val (expr))
4668 gimple_test_f = simple ? is_gimple_val : is_gimple_reg_rhs;
4670 push_gimplify_context ();
4671 gimplify_ctxp->into_ssa = true;
4674 expr = build (MODIFY_EXPR, TREE_TYPE (var), var, expr);
4676 ret = gimplify_expr (&expr, stmts, NULL,
4677 gimple_test_f, fb_rvalue);
4678 gcc_assert (ret != GS_ERROR);
4680 for (t = gimplify_ctxp->temps; t ; t = TREE_CHAIN (t))
4681 add_referenced_tmp_var (t);
4683 pop_gimplify_context (NULL);
4688 #include "gt-gimplify.h"