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 else if (TREE_CODE (decl) == TYPE_DECL)
987 gimplify_type_sizes (TREE_TYPE (decl), stmt_p);
989 else if (TREE_CODE (decl) == VAR_DECL && !DECL_EXTERNAL (decl))
991 tree init = DECL_INITIAL (decl);
993 if (!TREE_CONSTANT (DECL_SIZE (decl)))
995 /* This is a variable-sized decl. Simplify its size and mark it
996 for deferred expansion. Note that mudflap depends on the format
997 of the emitted code: see mx_register_decls(). */
998 tree t, args, addr, ptr_type;
1000 /* ??? We really shouldn't need to gimplify the type of the variable
1001 since it already should have been done. But leave this here
1002 for now to avoid disrupting too many things at once. */
1003 if (!TYPE_SIZES_GIMPLIFIED (TREE_TYPE (decl)))
1004 gimplify_type_sizes (TREE_TYPE (decl), stmt_p);
1006 gimplify_one_sizepos (&DECL_SIZE (decl), stmt_p);
1007 gimplify_one_sizepos (&DECL_SIZE_UNIT (decl), stmt_p);
1009 /* All occurrences of this decl in final gimplified code will be
1010 replaced by indirection. Setting DECL_VALUE_EXPR does two
1011 things: First, it lets the rest of the gimplifier know what
1012 replacement to use. Second, it lets the debug info know
1013 where to find the value. */
1014 ptr_type = build_pointer_type (TREE_TYPE (decl));
1015 addr = create_tmp_var (ptr_type, get_name (decl));
1016 DECL_IGNORED_P (addr) = 0;
1017 t = build_fold_indirect_ref (addr);
1018 DECL_VALUE_EXPR (decl) = t;
1020 args = tree_cons (NULL, DECL_SIZE_UNIT (decl), NULL);
1021 t = built_in_decls[BUILT_IN_ALLOCA];
1022 t = build_function_call_expr (t, args);
1023 t = fold_convert (ptr_type, t);
1024 t = build2 (MODIFY_EXPR, void_type_node, addr, t);
1026 gimplify_and_add (t, stmt_p);
1028 /* Indicate that we need to restore the stack level when the
1029 enclosing BIND_EXPR is exited. */
1030 gimplify_ctxp->save_stack = true;
1033 if (init && init != error_mark_node)
1035 if (!TREE_STATIC (decl))
1037 DECL_INITIAL (decl) = NULL_TREE;
1038 init = build (MODIFY_EXPR, void_type_node, decl, init);
1039 gimplify_and_add (init, stmt_p);
1042 /* We must still examine initializers for static variables
1043 as they may contain a label address. */
1044 walk_tree (&init, force_labels_r, NULL, NULL);
1047 /* This decl isn't mentioned in the enclosing block, so add it to the
1048 list of temps. FIXME it seems a bit of a kludge to say that
1049 anonymous artificial vars aren't pushed, but everything else is. */
1050 if (DECL_ARTIFICIAL (decl) && DECL_NAME (decl) == NULL_TREE)
1051 gimple_add_tmp_var (decl);
1057 /* Gimplify a LOOP_EXPR. Normally this just involves gimplifying the body
1058 and replacing the LOOP_EXPR with goto, but if the loop contains an
1059 EXIT_EXPR, we need to append a label for it to jump to. */
1061 static enum gimplify_status
1062 gimplify_loop_expr (tree *expr_p, tree *pre_p)
1064 tree saved_label = gimplify_ctxp->exit_label;
1065 tree start_label = build1 (LABEL_EXPR, void_type_node, NULL_TREE);
1066 tree jump_stmt = build_and_jump (&LABEL_EXPR_LABEL (start_label));
1068 append_to_statement_list (start_label, pre_p);
1070 gimplify_ctxp->exit_label = NULL_TREE;
1072 gimplify_and_add (LOOP_EXPR_BODY (*expr_p), pre_p);
1074 if (gimplify_ctxp->exit_label)
1076 append_to_statement_list (jump_stmt, pre_p);
1077 *expr_p = build1 (LABEL_EXPR, void_type_node, gimplify_ctxp->exit_label);
1080 *expr_p = jump_stmt;
1082 gimplify_ctxp->exit_label = saved_label;
1087 /* Compare two case labels. Because the front end should already have
1088 made sure that case ranges do not overlap, it is enough to only compare
1089 the CASE_LOW values of each case label. */
1092 compare_case_labels (const void *p1, const void *p2)
1094 tree case1 = *(tree *)p1;
1095 tree case2 = *(tree *)p2;
1097 return tree_int_cst_compare (CASE_LOW (case1), CASE_LOW (case2));
1100 /* Sort the case labels in LABEL_VEC in place in ascending order. */
1103 sort_case_labels (tree label_vec)
1105 size_t len = TREE_VEC_LENGTH (label_vec);
1106 tree default_case = TREE_VEC_ELT (label_vec, len - 1);
1108 if (CASE_LOW (default_case))
1112 /* The last label in the vector should be the default case
1114 for (i = 0; i < len; ++i)
1116 tree t = TREE_VEC_ELT (label_vec, i);
1120 TREE_VEC_ELT (label_vec, i) = TREE_VEC_ELT (label_vec, len - 1);
1121 TREE_VEC_ELT (label_vec, len - 1) = default_case;
1127 qsort (&TREE_VEC_ELT (label_vec, 0), len - 1, sizeof (tree),
1128 compare_case_labels);
1131 /* Gimplify a SWITCH_EXPR, and collect a TREE_VEC of the labels it can
1134 static enum gimplify_status
1135 gimplify_switch_expr (tree *expr_p, tree *pre_p)
1137 tree switch_expr = *expr_p;
1138 enum gimplify_status ret;
1140 ret = gimplify_expr (&SWITCH_COND (switch_expr), pre_p, NULL,
1141 is_gimple_val, fb_rvalue);
1143 if (SWITCH_BODY (switch_expr))
1145 varray_type labels, saved_labels;
1146 tree label_vec, default_case = NULL_TREE;
1149 /* If someone can be bothered to fill in the labels, they can
1150 be bothered to null out the body too. */
1151 gcc_assert (!SWITCH_LABELS (switch_expr));
1153 saved_labels = gimplify_ctxp->case_labels;
1154 VARRAY_TREE_INIT (gimplify_ctxp->case_labels, 8, "case_labels");
1156 gimplify_to_stmt_list (&SWITCH_BODY (switch_expr));
1158 labels = gimplify_ctxp->case_labels;
1159 gimplify_ctxp->case_labels = saved_labels;
1161 len = VARRAY_ACTIVE_SIZE (labels);
1163 for (i = 0; i < len; ++i)
1165 tree t = VARRAY_TREE (labels, i);
1168 /* The default case must be the last label in the list. */
1170 VARRAY_TREE (labels, i) = VARRAY_TREE (labels, len - 1);
1176 label_vec = make_tree_vec (len + 1);
1177 SWITCH_LABELS (*expr_p) = label_vec;
1178 append_to_statement_list (switch_expr, pre_p);
1182 /* If the switch has no default label, add one, so that we jump
1183 around the switch body. */
1184 default_case = build (CASE_LABEL_EXPR, void_type_node, NULL_TREE,
1185 NULL_TREE, create_artificial_label ());
1186 append_to_statement_list (SWITCH_BODY (switch_expr), pre_p);
1187 *expr_p = build (LABEL_EXPR, void_type_node,
1188 CASE_LABEL (default_case));
1191 *expr_p = SWITCH_BODY (switch_expr);
1193 for (i = 0; i < len; ++i)
1194 TREE_VEC_ELT (label_vec, i) = VARRAY_TREE (labels, i);
1195 TREE_VEC_ELT (label_vec, len) = default_case;
1197 sort_case_labels (label_vec);
1199 SWITCH_BODY (switch_expr) = NULL;
1202 gcc_assert (SWITCH_LABELS (switch_expr));
1207 static enum gimplify_status
1208 gimplify_case_label_expr (tree *expr_p)
1210 tree expr = *expr_p;
1212 gcc_assert (gimplify_ctxp->case_labels);
1213 VARRAY_PUSH_TREE (gimplify_ctxp->case_labels, expr);
1214 *expr_p = build (LABEL_EXPR, void_type_node, CASE_LABEL (expr));
1218 /* Build a GOTO to the LABEL_DECL pointed to by LABEL_P, building it first
1222 build_and_jump (tree *label_p)
1224 if (label_p == NULL)
1225 /* If there's nowhere to jump, just fall through. */
1228 if (*label_p == NULL_TREE)
1230 tree label = create_artificial_label ();
1234 return build1 (GOTO_EXPR, void_type_node, *label_p);
1237 /* Gimplify an EXIT_EXPR by converting to a GOTO_EXPR inside a COND_EXPR.
1238 This also involves building a label to jump to and communicating it to
1239 gimplify_loop_expr through gimplify_ctxp->exit_label. */
1241 static enum gimplify_status
1242 gimplify_exit_expr (tree *expr_p)
1244 tree cond = TREE_OPERAND (*expr_p, 0);
1247 expr = build_and_jump (&gimplify_ctxp->exit_label);
1248 expr = build (COND_EXPR, void_type_node, cond, expr, NULL_TREE);
1254 /* A helper function to be called via walk_tree. Mark all labels under *TP
1255 as being forced. To be called for DECL_INITIAL of static variables. */
1258 force_labels_r (tree *tp, int *walk_subtrees, void *data ATTRIBUTE_UNUSED)
1262 if (TREE_CODE (*tp) == LABEL_DECL)
1263 FORCED_LABEL (*tp) = 1;
1268 /* *EXPR_P is a COMPONENT_REF being used as an rvalue. If its type is
1269 different from its canonical type, wrap the whole thing inside a
1270 NOP_EXPR and force the type of the COMPONENT_REF to be the canonical
1273 The canonical type of a COMPONENT_REF is the type of the field being
1274 referenced--unless the field is a bit-field which can be read directly
1275 in a smaller mode, in which case the canonical type is the
1276 sign-appropriate type corresponding to that mode. */
1279 canonicalize_component_ref (tree *expr_p)
1281 tree expr = *expr_p;
1284 gcc_assert (TREE_CODE (expr) == COMPONENT_REF);
1286 if (INTEGRAL_TYPE_P (TREE_TYPE (expr)))
1287 type = TREE_TYPE (get_unwidened (expr, NULL_TREE));
1289 type = TREE_TYPE (TREE_OPERAND (expr, 1));
1291 if (TREE_TYPE (expr) != type)
1293 tree old_type = TREE_TYPE (expr);
1295 /* Set the type of the COMPONENT_REF to the underlying type. */
1296 TREE_TYPE (expr) = type;
1298 /* And wrap the whole thing inside a NOP_EXPR. */
1299 expr = build1 (NOP_EXPR, old_type, expr);
1305 /* If a NOP conversion is changing a pointer to array of foo to a pointer
1306 to foo, embed that change in the ADDR_EXPR by converting
1311 where L is the lower bound. For simplicity, only do this for constant
1315 canonicalize_addr_expr (tree *expr_p)
1317 tree expr = *expr_p;
1318 tree ctype = TREE_TYPE (expr);
1319 tree addr_expr = TREE_OPERAND (expr, 0);
1320 tree atype = TREE_TYPE (addr_expr);
1321 tree dctype, datype, ddatype, otype, obj_expr;
1323 /* Both cast and addr_expr types should be pointers. */
1324 if (!POINTER_TYPE_P (ctype) || !POINTER_TYPE_P (atype))
1327 /* The addr_expr type should be a pointer to an array. */
1328 datype = TREE_TYPE (atype);
1329 if (TREE_CODE (datype) != ARRAY_TYPE)
1332 /* Both cast and addr_expr types should address the same object type. */
1333 dctype = TREE_TYPE (ctype);
1334 ddatype = TREE_TYPE (datype);
1335 if (!lang_hooks.types_compatible_p (ddatype, dctype))
1338 /* The addr_expr and the object type should match. */
1339 obj_expr = TREE_OPERAND (addr_expr, 0);
1340 otype = TREE_TYPE (obj_expr);
1341 if (!lang_hooks.types_compatible_p (otype, datype))
1344 /* The lower bound and element sizes must be constant. */
1345 if (!TYPE_SIZE_UNIT (dctype)
1346 || TREE_CODE (TYPE_SIZE_UNIT (dctype)) != INTEGER_CST
1347 || !TYPE_DOMAIN (datype) || !TYPE_MIN_VALUE (TYPE_DOMAIN (datype))
1348 || TREE_CODE (TYPE_MIN_VALUE (TYPE_DOMAIN (datype))) != INTEGER_CST)
1351 /* All checks succeeded. Build a new node to merge the cast. */
1352 *expr_p = build4 (ARRAY_REF, dctype, obj_expr,
1353 TYPE_MIN_VALUE (TYPE_DOMAIN (datype)),
1354 TYPE_MIN_VALUE (TYPE_DOMAIN (datype)),
1355 size_binop (EXACT_DIV_EXPR, TYPE_SIZE_UNIT (dctype),
1356 size_int (TYPE_ALIGN_UNIT (dctype))));
1357 *expr_p = build1 (ADDR_EXPR, ctype, *expr_p);
1360 /* *EXPR_P is a NOP_EXPR or CONVERT_EXPR. Remove it and/or other conversions
1361 underneath as appropriate. */
1363 static enum gimplify_status
1364 gimplify_conversion (tree *expr_p)
1366 gcc_assert (TREE_CODE (*expr_p) == NOP_EXPR
1367 || TREE_CODE (*expr_p) == CONVERT_EXPR);
1369 /* Then strip away all but the outermost conversion. */
1370 STRIP_SIGN_NOPS (TREE_OPERAND (*expr_p, 0));
1372 /* And remove the outermost conversion if it's useless. */
1373 if (tree_ssa_useless_type_conversion (*expr_p))
1374 *expr_p = TREE_OPERAND (*expr_p, 0);
1376 /* If we still have a conversion at the toplevel,
1377 then canonicalize some constructs. */
1378 if (TREE_CODE (*expr_p) == NOP_EXPR || TREE_CODE (*expr_p) == CONVERT_EXPR)
1380 tree sub = TREE_OPERAND (*expr_p, 0);
1382 /* If a NOP conversion is changing the type of a COMPONENT_REF
1383 expression, then canonicalize its type now in order to expose more
1384 redundant conversions. */
1385 if (TREE_CODE (sub) == COMPONENT_REF)
1386 canonicalize_component_ref (&TREE_OPERAND (*expr_p, 0));
1388 /* If a NOP conversion is changing a pointer to array of foo
1389 to a pointer to foo, embed that change in the ADDR_EXPR. */
1390 else if (TREE_CODE (sub) == ADDR_EXPR)
1391 canonicalize_addr_expr (expr_p);
1397 /* Gimplify the COMPONENT_REF, ARRAY_REF, REALPART_EXPR or IMAGPART_EXPR
1398 node pointed by EXPR_P.
1401 : min_lval '[' val ']'
1403 | compound_lval '[' val ']'
1404 | compound_lval '.' ID
1406 This is not part of the original SIMPLE definition, which separates
1407 array and member references, but it seems reasonable to handle them
1408 together. Also, this way we don't run into problems with union
1409 aliasing; gcc requires that for accesses through a union to alias, the
1410 union reference must be explicit, which was not always the case when we
1411 were splitting up array and member refs.
1413 PRE_P points to the list where side effects that must happen before
1414 *EXPR_P should be stored.
1416 POST_P points to the list where side effects that must happen after
1417 *EXPR_P should be stored. */
1419 static enum gimplify_status
1420 gimplify_compound_lval (tree *expr_p, tree *pre_p,
1421 tree *post_p, fallback_t fallback)
1425 enum gimplify_status ret = GS_OK, tret;
1428 /* Create a stack of the subexpressions so later we can walk them in
1429 order from inner to outer.
1431 This array is very memory consuming. Don't even think of making
1433 VARRAY_GENERIC_PTR_NOGC_INIT (stack, 10, "stack");
1435 /* We can handle anything that get_inner_reference can deal with. */
1436 for (p = expr_p; ; p = &TREE_OPERAND (*p, 0))
1438 /* Fold INDIRECT_REFs now to turn them into ARRAY_REFs. */
1439 if (TREE_CODE (*p) == INDIRECT_REF)
1440 *p = fold_indirect_ref (*p);
1441 if (!handled_component_p (*p))
1443 VARRAY_PUSH_GENERIC_PTR_NOGC (stack, *p);
1446 gcc_assert (VARRAY_ACTIVE_SIZE (stack));
1448 /* Now STACK is a stack of pointers to all the refs we've walked through
1449 and P points to the innermost expression.
1451 Java requires that we elaborated nodes in source order. That
1452 means we must gimplify the inner expression followed by each of
1453 the indices, in order. But we can't gimplify the inner
1454 expression until we deal with any variable bounds, sizes, or
1455 positions in order to deal with PLACEHOLDER_EXPRs.
1457 So we do this in three steps. First we deal with the annotations
1458 for any variables in the components, then we gimplify the base,
1459 then we gimplify any indices, from left to right. */
1460 for (i = VARRAY_ACTIVE_SIZE (stack) - 1; i >= 0; i--)
1462 tree t = VARRAY_GENERIC_PTR_NOGC (stack, i);
1464 if (TREE_CODE (t) == ARRAY_REF || TREE_CODE (t) == ARRAY_RANGE_REF)
1466 /* Gimplify the low bound and element type size and put them into
1467 the ARRAY_REF. If these values are set, they have already been
1469 if (!TREE_OPERAND (t, 2))
1471 tree low = unshare_expr (array_ref_low_bound (t));
1472 if (!is_gimple_min_invariant (low))
1474 TREE_OPERAND (t, 2) = low;
1475 tret = gimplify_expr (&TREE_OPERAND (t, 2), pre_p, post_p,
1476 is_gimple_formal_tmp_reg, fb_rvalue);
1477 ret = MIN (ret, tret);
1481 if (!TREE_OPERAND (t, 3))
1483 tree elmt_type = TREE_TYPE (TREE_TYPE (TREE_OPERAND (t, 0)));
1484 tree elmt_size = unshare_expr (array_ref_element_size (t));
1485 tree factor = size_int (TYPE_ALIGN_UNIT (elmt_type));
1487 /* Divide the element size by the alignment of the element
1489 elmt_size = size_binop (EXACT_DIV_EXPR, elmt_size, factor);
1491 if (!is_gimple_min_invariant (elmt_size))
1493 TREE_OPERAND (t, 3) = elmt_size;
1494 tret = gimplify_expr (&TREE_OPERAND (t, 3), pre_p, post_p,
1495 is_gimple_formal_tmp_reg, fb_rvalue);
1496 ret = MIN (ret, tret);
1500 else if (TREE_CODE (t) == COMPONENT_REF)
1502 /* Set the field offset into T and gimplify it. */
1503 if (!TREE_OPERAND (t, 2))
1505 tree offset = unshare_expr (component_ref_field_offset (t));
1506 tree field = TREE_OPERAND (t, 1);
1508 = size_int (DECL_OFFSET_ALIGN (field) / BITS_PER_UNIT);
1510 /* Divide the offset by its alignment. */
1511 offset = size_binop (EXACT_DIV_EXPR, offset, factor);
1513 if (!is_gimple_min_invariant (offset))
1515 TREE_OPERAND (t, 2) = offset;
1516 tret = gimplify_expr (&TREE_OPERAND (t, 2), pre_p, post_p,
1517 is_gimple_formal_tmp_reg, fb_rvalue);
1518 ret = MIN (ret, tret);
1524 /* Step 2 is to gimplify the base expression. */
1525 tret = gimplify_expr (p, pre_p, post_p, is_gimple_min_lval, fallback);
1526 ret = MIN (ret, tret);
1528 /* And finally, the indices and operands to BIT_FIELD_REF. During this
1529 loop we also remove any useless conversions. */
1530 for (; VARRAY_ACTIVE_SIZE (stack) > 0; )
1532 tree t = VARRAY_TOP_TREE (stack);
1534 if (TREE_CODE (t) == ARRAY_REF || TREE_CODE (t) == ARRAY_RANGE_REF)
1536 /* Gimplify the dimension.
1537 Temporary fix for gcc.c-torture/execute/20040313-1.c.
1538 Gimplify non-constant array indices into a temporary
1540 FIXME - The real fix is to gimplify post-modify
1541 expressions into a minimal gimple lvalue. However, that
1542 exposes bugs in alias analysis. The alias analyzer does
1543 not handle &PTR->FIELD very well. Will fix after the
1544 branch is merged into mainline (dnovillo 2004-05-03). */
1545 if (!is_gimple_min_invariant (TREE_OPERAND (t, 1)))
1547 tret = gimplify_expr (&TREE_OPERAND (t, 1), pre_p, post_p,
1548 is_gimple_formal_tmp_reg, fb_rvalue);
1549 ret = MIN (ret, tret);
1552 else if (TREE_CODE (t) == BIT_FIELD_REF)
1554 tret = gimplify_expr (&TREE_OPERAND (t, 1), pre_p, post_p,
1555 is_gimple_val, fb_rvalue);
1556 ret = MIN (ret, tret);
1557 tret = gimplify_expr (&TREE_OPERAND (t, 2), pre_p, post_p,
1558 is_gimple_val, fb_rvalue);
1559 ret = MIN (ret, tret);
1562 STRIP_USELESS_TYPE_CONVERSION (TREE_OPERAND (t, 0));
1564 /* The innermost expression P may have originally had TREE_SIDE_EFFECTS
1565 set which would have caused all the outer expressions in EXPR_P
1566 leading to P to also have had TREE_SIDE_EFFECTS set. */
1567 recalculate_side_effects (t);
1571 tret = gimplify_expr (p, pre_p, post_p, is_gimple_min_lval, fallback);
1572 ret = MIN (ret, tret);
1574 /* If the outermost expression is a COMPONENT_REF, canonicalize its type. */
1575 if ((fallback & fb_rvalue) && TREE_CODE (*expr_p) == COMPONENT_REF)
1577 canonicalize_component_ref (expr_p);
1578 ret = MIN (ret, GS_OK);
1581 VARRAY_FREE (stack);
1586 /* Gimplify the self modifying expression pointed by EXPR_P (++, --, +=, -=).
1588 PRE_P points to the list where side effects that must happen before
1589 *EXPR_P should be stored.
1591 POST_P points to the list where side effects that must happen after
1592 *EXPR_P should be stored.
1594 WANT_VALUE is nonzero iff we want to use the value of this expression
1595 in another expression. */
1597 static enum gimplify_status
1598 gimplify_self_mod_expr (tree *expr_p, tree *pre_p, tree *post_p,
1601 enum tree_code code;
1602 tree lhs, lvalue, rhs, t1;
1604 enum tree_code arith_code;
1605 enum gimplify_status ret;
1607 code = TREE_CODE (*expr_p);
1609 gcc_assert (code == POSTINCREMENT_EXPR || code == POSTDECREMENT_EXPR
1610 || code == PREINCREMENT_EXPR || code == PREDECREMENT_EXPR);
1612 /* Prefix or postfix? */
1613 if (code == POSTINCREMENT_EXPR || code == POSTDECREMENT_EXPR)
1614 /* Faster to treat as prefix if result is not used. */
1615 postfix = want_value;
1619 /* Add or subtract? */
1620 if (code == PREINCREMENT_EXPR || code == POSTINCREMENT_EXPR)
1621 arith_code = PLUS_EXPR;
1623 arith_code = MINUS_EXPR;
1625 /* Gimplify the LHS into a GIMPLE lvalue. */
1626 lvalue = TREE_OPERAND (*expr_p, 0);
1627 ret = gimplify_expr (&lvalue, pre_p, post_p, is_gimple_lvalue, fb_lvalue);
1628 if (ret == GS_ERROR)
1631 /* Extract the operands to the arithmetic operation. */
1633 rhs = TREE_OPERAND (*expr_p, 1);
1635 /* For postfix operator, we evaluate the LHS to an rvalue and then use
1636 that as the result value and in the postqueue operation. */
1639 ret = gimplify_expr (&lhs, pre_p, post_p, is_gimple_val, fb_rvalue);
1640 if (ret == GS_ERROR)
1644 t1 = build (arith_code, TREE_TYPE (*expr_p), lhs, rhs);
1645 t1 = build (MODIFY_EXPR, TREE_TYPE (lvalue), lvalue, t1);
1649 gimplify_and_add (t1, post_p);
1660 /* If *EXPR_P has a variable sized type, wrap it in a WITH_SIZE_EXPR. */
1663 maybe_with_size_expr (tree *expr_p)
1665 tree expr = *expr_p;
1666 tree type = TREE_TYPE (expr);
1669 /* If we've already wrapped this or the type is error_mark_node, we can't do
1671 if (TREE_CODE (expr) == WITH_SIZE_EXPR
1672 || type == error_mark_node)
1675 /* If the size isn't known or is a constant, we have nothing to do. */
1676 size = TYPE_SIZE_UNIT (type);
1677 if (!size || TREE_CODE (size) == INTEGER_CST)
1680 /* Otherwise, make a WITH_SIZE_EXPR. */
1681 size = unshare_expr (size);
1682 size = SUBSTITUTE_PLACEHOLDER_IN_EXPR (size, expr);
1683 *expr_p = build2 (WITH_SIZE_EXPR, type, expr, size);
1686 /* Subroutine of gimplify_call_expr: Gimplify a single argument. */
1688 static enum gimplify_status
1689 gimplify_arg (tree *expr_p, tree *pre_p)
1691 bool (*test) (tree);
1694 /* In general, we allow lvalues for function arguments to avoid
1695 extra overhead of copying large aggregates out of even larger
1696 aggregates into temporaries only to copy the temporaries to
1697 the argument list. Make optimizers happy by pulling out to
1698 temporaries those types that fit in registers. */
1699 if (is_gimple_reg_type (TREE_TYPE (*expr_p)))
1700 test = is_gimple_val, fb = fb_rvalue;
1702 test = is_gimple_lvalue, fb = fb_either;
1704 /* If this is a variable sized type, we must remember the size. */
1705 maybe_with_size_expr (expr_p);
1707 /* There is a sequence point before a function call. Side effects in
1708 the argument list must occur before the actual call. So, when
1709 gimplifying arguments, force gimplify_expr to use an internal
1710 post queue which is then appended to the end of PRE_P. */
1711 return gimplify_expr (expr_p, pre_p, NULL, test, fb);
1714 /* Gimplify the CALL_EXPR node pointed by EXPR_P. PRE_P points to the
1715 list where side effects that must happen before *EXPR_P should be stored.
1716 WANT_VALUE is true if the result of the call is desired. */
1718 static enum gimplify_status
1719 gimplify_call_expr (tree *expr_p, tree *pre_p, bool want_value)
1723 enum gimplify_status ret;
1725 gcc_assert (TREE_CODE (*expr_p) == CALL_EXPR);
1727 /* For reliable diagnostics during inlining, it is necessary that
1728 every call_expr be annotated with file and line. */
1729 if (! EXPR_HAS_LOCATION (*expr_p))
1730 SET_EXPR_LOCATION (*expr_p, input_location);
1732 /* This may be a call to a builtin function.
1734 Builtin function calls may be transformed into different
1735 (and more efficient) builtin function calls under certain
1736 circumstances. Unfortunately, gimplification can muck things
1737 up enough that the builtin expanders are not aware that certain
1738 transformations are still valid.
1740 So we attempt transformation/gimplification of the call before
1741 we gimplify the CALL_EXPR. At this time we do not manage to
1742 transform all calls in the same manner as the expanders do, but
1743 we do transform most of them. */
1744 decl = get_callee_fndecl (*expr_p);
1745 if (decl && DECL_BUILT_IN (decl))
1747 tree new = fold_builtin (*expr_p, !want_value);
1749 if (new && new != *expr_p)
1751 /* There was a transformation of this call which computes the
1752 same value, but in a more efficient way. Return and try
1758 if (DECL_BUILT_IN_CLASS (decl) == BUILT_IN_NORMAL
1759 && DECL_FUNCTION_CODE (decl) == BUILT_IN_VA_START)
1761 tree arglist = TREE_OPERAND (*expr_p, 1);
1763 if (!arglist || !TREE_CHAIN (arglist))
1765 error ("too few arguments to function %<va_start%>");
1766 *expr_p = build_empty_stmt ();
1770 if (fold_builtin_next_arg (TREE_CHAIN (arglist)))
1772 *expr_p = build_empty_stmt ();
1775 /* Avoid gimplifying the second argument to va_start, which needs
1776 to be the plain PARM_DECL. */
1777 return gimplify_arg (&TREE_VALUE (TREE_OPERAND (*expr_p, 1)), pre_p);
1781 /* There is a sequence point before the call, so any side effects in
1782 the calling expression must occur before the actual call. Force
1783 gimplify_expr to use an internal post queue. */
1784 ret = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p, NULL,
1785 is_gimple_call_addr, fb_rvalue);
1787 if (PUSH_ARGS_REVERSED)
1788 TREE_OPERAND (*expr_p, 1) = nreverse (TREE_OPERAND (*expr_p, 1));
1789 for (arglist = TREE_OPERAND (*expr_p, 1); arglist;
1790 arglist = TREE_CHAIN (arglist))
1792 enum gimplify_status t;
1794 t = gimplify_arg (&TREE_VALUE (arglist), pre_p);
1799 if (PUSH_ARGS_REVERSED)
1800 TREE_OPERAND (*expr_p, 1) = nreverse (TREE_OPERAND (*expr_p, 1));
1802 /* Try this again in case gimplification exposed something. */
1803 if (ret != GS_ERROR && decl && DECL_BUILT_IN (decl))
1805 tree new = fold_builtin (*expr_p, !want_value);
1807 if (new && new != *expr_p)
1809 /* There was a transformation of this call which computes the
1810 same value, but in a more efficient way. Return and try
1817 /* If the function is "const" or "pure", then clear TREE_SIDE_EFFECTS on its
1818 decl. This allows us to eliminate redundant or useless
1819 calls to "const" functions. */
1820 if (TREE_CODE (*expr_p) == CALL_EXPR
1821 && (call_expr_flags (*expr_p) & (ECF_CONST | ECF_PURE)))
1822 TREE_SIDE_EFFECTS (*expr_p) = 0;
1827 /* Handle shortcut semantics in the predicate operand of a COND_EXPR by
1828 rewriting it into multiple COND_EXPRs, and possibly GOTO_EXPRs.
1830 TRUE_LABEL_P and FALSE_LABEL_P point to the labels to jump to if the
1831 condition is true or false, respectively. If null, we should generate
1832 our own to skip over the evaluation of this specific expression.
1834 This function is the tree equivalent of do_jump.
1836 shortcut_cond_r should only be called by shortcut_cond_expr. */
1839 shortcut_cond_r (tree pred, tree *true_label_p, tree *false_label_p)
1841 tree local_label = NULL_TREE;
1842 tree t, expr = NULL;
1844 /* OK, it's not a simple case; we need to pull apart the COND_EXPR to
1845 retain the shortcut semantics. Just insert the gotos here;
1846 shortcut_cond_expr will append the real blocks later. */
1847 if (TREE_CODE (pred) == TRUTH_ANDIF_EXPR)
1849 /* Turn if (a && b) into
1851 if (a); else goto no;
1852 if (b) goto yes; else goto no;
1855 if (false_label_p == NULL)
1856 false_label_p = &local_label;
1858 t = shortcut_cond_r (TREE_OPERAND (pred, 0), NULL, false_label_p);
1859 append_to_statement_list (t, &expr);
1861 t = shortcut_cond_r (TREE_OPERAND (pred, 1), true_label_p,
1863 append_to_statement_list (t, &expr);
1865 else if (TREE_CODE (pred) == TRUTH_ORIF_EXPR)
1867 /* Turn if (a || b) into
1870 if (b) goto yes; else goto no;
1873 if (true_label_p == NULL)
1874 true_label_p = &local_label;
1876 t = shortcut_cond_r (TREE_OPERAND (pred, 0), true_label_p, NULL);
1877 append_to_statement_list (t, &expr);
1879 t = shortcut_cond_r (TREE_OPERAND (pred, 1), true_label_p,
1881 append_to_statement_list (t, &expr);
1883 else if (TREE_CODE (pred) == COND_EXPR)
1885 /* As long as we're messing with gotos, turn if (a ? b : c) into
1887 if (b) goto yes; else goto no;
1889 if (c) goto yes; else goto no; */
1890 expr = build (COND_EXPR, void_type_node, TREE_OPERAND (pred, 0),
1891 shortcut_cond_r (TREE_OPERAND (pred, 1), true_label_p,
1893 shortcut_cond_r (TREE_OPERAND (pred, 2), true_label_p,
1898 expr = build (COND_EXPR, void_type_node, pred,
1899 build_and_jump (true_label_p),
1900 build_and_jump (false_label_p));
1905 t = build1 (LABEL_EXPR, void_type_node, local_label);
1906 append_to_statement_list (t, &expr);
1913 shortcut_cond_expr (tree expr)
1915 tree pred = TREE_OPERAND (expr, 0);
1916 tree then_ = TREE_OPERAND (expr, 1);
1917 tree else_ = TREE_OPERAND (expr, 2);
1918 tree true_label, false_label, end_label, t;
1920 tree *false_label_p;
1921 bool emit_end, emit_false, jump_over_else;
1922 bool then_se = then_ && TREE_SIDE_EFFECTS (then_);
1923 bool else_se = else_ && TREE_SIDE_EFFECTS (else_);
1925 /* First do simple transformations. */
1928 /* If there is no 'else', turn (a && b) into if (a) if (b). */
1929 while (TREE_CODE (pred) == TRUTH_ANDIF_EXPR)
1931 TREE_OPERAND (expr, 0) = TREE_OPERAND (pred, 1);
1932 then_ = shortcut_cond_expr (expr);
1933 then_se = then_ && TREE_SIDE_EFFECTS (then_);
1934 pred = TREE_OPERAND (pred, 0);
1935 expr = build (COND_EXPR, void_type_node, pred, then_, NULL_TREE);
1940 /* If there is no 'then', turn
1943 if (a); else if (b); else d. */
1944 while (TREE_CODE (pred) == TRUTH_ORIF_EXPR)
1946 TREE_OPERAND (expr, 0) = TREE_OPERAND (pred, 1);
1947 else_ = shortcut_cond_expr (expr);
1948 else_se = else_ && TREE_SIDE_EFFECTS (else_);
1949 pred = TREE_OPERAND (pred, 0);
1950 expr = build (COND_EXPR, void_type_node, pred, NULL_TREE, else_);
1954 /* If we're done, great. */
1955 if (TREE_CODE (pred) != TRUTH_ANDIF_EXPR
1956 && TREE_CODE (pred) != TRUTH_ORIF_EXPR)
1959 /* Otherwise we need to mess with gotos. Change
1962 if (a); else goto no;
1965 and recursively gimplify the condition. */
1967 true_label = false_label = end_label = NULL_TREE;
1969 /* If our arms just jump somewhere, hijack those labels so we don't
1970 generate jumps to jumps. */
1973 && TREE_CODE (then_) == GOTO_EXPR
1974 && TREE_CODE (GOTO_DESTINATION (then_)) == LABEL_DECL)
1976 true_label = GOTO_DESTINATION (then_);
1982 && TREE_CODE (else_) == GOTO_EXPR
1983 && TREE_CODE (GOTO_DESTINATION (else_)) == LABEL_DECL)
1985 false_label = GOTO_DESTINATION (else_);
1990 /* If we aren't hijacking a label for the 'then' branch, it falls through. */
1992 true_label_p = &true_label;
1994 true_label_p = NULL;
1996 /* The 'else' branch also needs a label if it contains interesting code. */
1997 if (false_label || else_se)
1998 false_label_p = &false_label;
2000 false_label_p = NULL;
2002 /* If there was nothing else in our arms, just forward the label(s). */
2003 if (!then_se && !else_se)
2004 return shortcut_cond_r (pred, true_label_p, false_label_p);
2006 /* If our last subexpression already has a terminal label, reuse it. */
2008 expr = expr_last (else_);
2010 expr = expr_last (then_);
2013 if (expr && TREE_CODE (expr) == LABEL_EXPR)
2014 end_label = LABEL_EXPR_LABEL (expr);
2016 /* If we don't care about jumping to the 'else' branch, jump to the end
2017 if the condition is false. */
2019 false_label_p = &end_label;
2021 /* We only want to emit these labels if we aren't hijacking them. */
2022 emit_end = (end_label == NULL_TREE);
2023 emit_false = (false_label == NULL_TREE);
2025 /* We only emit the jump over the else clause if we have to--if the
2026 then clause may fall through. Otherwise we can wind up with a
2027 useless jump and a useless label at the end of gimplified code,
2028 which will cause us to think that this conditional as a whole
2029 falls through even if it doesn't. If we then inline a function
2030 which ends with such a condition, that can cause us to issue an
2031 inappropriate warning about control reaching the end of a
2032 non-void function. */
2033 jump_over_else = block_may_fallthru (then_);
2035 pred = shortcut_cond_r (pred, true_label_p, false_label_p);
2038 append_to_statement_list (pred, &expr);
2040 append_to_statement_list (then_, &expr);
2045 t = build_and_jump (&end_label);
2046 append_to_statement_list (t, &expr);
2050 t = build1 (LABEL_EXPR, void_type_node, false_label);
2051 append_to_statement_list (t, &expr);
2053 append_to_statement_list (else_, &expr);
2055 if (emit_end && end_label)
2057 t = build1 (LABEL_EXPR, void_type_node, end_label);
2058 append_to_statement_list (t, &expr);
2064 /* EXPR is used in a boolean context; make sure it has BOOLEAN_TYPE. */
2067 gimple_boolify (tree expr)
2069 tree type = TREE_TYPE (expr);
2071 if (TREE_CODE (type) == BOOLEAN_TYPE)
2074 /* If this is the predicate of a COND_EXPR, it might not even be a
2076 expr = lang_hooks.truthvalue_conversion (expr);
2078 switch (TREE_CODE (expr))
2080 case TRUTH_AND_EXPR:
2082 case TRUTH_XOR_EXPR:
2083 case TRUTH_ANDIF_EXPR:
2084 case TRUTH_ORIF_EXPR:
2085 /* Also boolify the arguments of truth exprs. */
2086 TREE_OPERAND (expr, 1) = gimple_boolify (TREE_OPERAND (expr, 1));
2089 case TRUTH_NOT_EXPR:
2090 TREE_OPERAND (expr, 0) = gimple_boolify (TREE_OPERAND (expr, 0));
2093 case EQ_EXPR: case NE_EXPR:
2094 case LE_EXPR: case GE_EXPR: case LT_EXPR: case GT_EXPR:
2095 /* These expressions always produce boolean results. */
2096 TREE_TYPE (expr) = boolean_type_node;
2100 /* Other expressions that get here must have boolean values, but
2101 might need to be converted to the appropriate mode. */
2102 return convert (boolean_type_node, expr);
2106 /* Convert the conditional expression pointed by EXPR_P '(p) ? a : b;'
2115 The second form is used when *EXPR_P is of type void.
2117 TARGET is the tree for T1 above.
2119 PRE_P points to the list where side effects that must happen before
2120 *EXPR_P should be stored.
2122 POST_P points to the list where side effects that must happen after
2123 *EXPR_P should be stored. */
2125 static enum gimplify_status
2126 gimplify_cond_expr (tree *expr_p, tree *pre_p, tree *post_p, tree target,
2127 fallback_t fallback)
2129 tree expr = *expr_p;
2130 tree tmp, tmp2, type;
2131 enum gimplify_status ret;
2133 type = TREE_TYPE (expr);
2135 TREE_TYPE (expr) = void_type_node;
2137 /* If this COND_EXPR has a value, copy the values into a temporary within
2139 else if (! VOID_TYPE_P (type))
2145 ret = gimplify_expr (&target, pre_p, post_p,
2146 is_gimple_min_lval, fb_lvalue);
2147 if (ret != GS_ERROR)
2149 result = tmp = target;
2150 tmp2 = unshare_expr (target);
2152 else if ((fallback & fb_lvalue) == 0)
2154 result = tmp2 = tmp = create_tmp_var (TREE_TYPE (expr), "iftmp");
2159 tree type = build_pointer_type (TREE_TYPE (expr));
2161 if (TREE_TYPE (TREE_OPERAND (expr, 1)) != void_type_node)
2162 TREE_OPERAND (expr, 1) =
2163 build_fold_addr_expr (TREE_OPERAND (expr, 1));
2165 if (TREE_TYPE (TREE_OPERAND (expr, 2)) != void_type_node)
2166 TREE_OPERAND (expr, 2) =
2167 build_fold_addr_expr (TREE_OPERAND (expr, 2));
2169 tmp2 = tmp = create_tmp_var (type, "iftmp");
2171 expr = build (COND_EXPR, void_type_node, TREE_OPERAND (expr, 0),
2172 TREE_OPERAND (expr, 1), TREE_OPERAND (expr, 2));
2174 result = build_fold_indirect_ref (tmp);
2178 /* Build the then clause, 't1 = a;'. But don't build an assignment
2179 if this branch is void; in C++ it can be, if it's a throw. */
2180 if (TREE_TYPE (TREE_OPERAND (expr, 1)) != void_type_node)
2181 TREE_OPERAND (expr, 1)
2182 = build (MODIFY_EXPR, void_type_node, tmp, TREE_OPERAND (expr, 1));
2184 /* Build the else clause, 't1 = b;'. */
2185 if (TREE_TYPE (TREE_OPERAND (expr, 2)) != void_type_node)
2186 TREE_OPERAND (expr, 2)
2187 = build (MODIFY_EXPR, void_type_node, tmp2, TREE_OPERAND (expr, 2));
2189 TREE_TYPE (expr) = void_type_node;
2190 recalculate_side_effects (expr);
2192 /* Move the COND_EXPR to the prequeue. */
2193 gimplify_and_add (expr, pre_p);
2199 /* Make sure the condition has BOOLEAN_TYPE. */
2200 TREE_OPERAND (expr, 0) = gimple_boolify (TREE_OPERAND (expr, 0));
2202 /* Break apart && and || conditions. */
2203 if (TREE_CODE (TREE_OPERAND (expr, 0)) == TRUTH_ANDIF_EXPR
2204 || TREE_CODE (TREE_OPERAND (expr, 0)) == TRUTH_ORIF_EXPR)
2206 expr = shortcut_cond_expr (expr);
2208 if (expr != *expr_p)
2212 /* We can't rely on gimplify_expr to re-gimplify the expanded
2213 form properly, as cleanups might cause the target labels to be
2214 wrapped in a TRY_FINALLY_EXPR. To prevent that, we need to
2215 set up a conditional context. */
2216 gimple_push_condition ();
2217 gimplify_stmt (expr_p);
2218 gimple_pop_condition (pre_p);
2224 /* Now do the normal gimplification. */
2225 ret = gimplify_expr (&TREE_OPERAND (expr, 0), pre_p, NULL,
2226 is_gimple_condexpr, fb_rvalue);
2228 gimple_push_condition ();
2230 gimplify_to_stmt_list (&TREE_OPERAND (expr, 1));
2231 gimplify_to_stmt_list (&TREE_OPERAND (expr, 2));
2232 recalculate_side_effects (expr);
2234 gimple_pop_condition (pre_p);
2236 if (ret == GS_ERROR)
2238 else if (TREE_SIDE_EFFECTS (TREE_OPERAND (expr, 1)))
2240 else if (TREE_SIDE_EFFECTS (TREE_OPERAND (expr, 2)))
2241 /* Rewrite "if (a); else b" to "if (!a) b" */
2243 TREE_OPERAND (expr, 0) = invert_truthvalue (TREE_OPERAND (expr, 0));
2244 ret = gimplify_expr (&TREE_OPERAND (expr, 0), pre_p, NULL,
2245 is_gimple_condexpr, fb_rvalue);
2247 tmp = TREE_OPERAND (expr, 1);
2248 TREE_OPERAND (expr, 1) = TREE_OPERAND (expr, 2);
2249 TREE_OPERAND (expr, 2) = tmp;
2252 /* Both arms are empty; replace the COND_EXPR with its predicate. */
2253 expr = TREE_OPERAND (expr, 0);
2259 /* A subroutine of gimplify_modify_expr. Replace a MODIFY_EXPR with
2260 a call to __builtin_memcpy. */
2262 static enum gimplify_status
2263 gimplify_modify_expr_to_memcpy (tree *expr_p, tree size, bool want_value)
2265 tree args, t, to, to_ptr, from;
2267 to = TREE_OPERAND (*expr_p, 0);
2268 from = TREE_OPERAND (*expr_p, 1);
2270 args = tree_cons (NULL, size, NULL);
2272 t = build_fold_addr_expr (from);
2273 args = tree_cons (NULL, t, args);
2275 to_ptr = build_fold_addr_expr (to);
2276 args = tree_cons (NULL, to_ptr, args);
2277 t = implicit_built_in_decls[BUILT_IN_MEMCPY];
2278 t = build_function_call_expr (t, args);
2282 t = build1 (NOP_EXPR, TREE_TYPE (to_ptr), t);
2283 t = build1 (INDIRECT_REF, TREE_TYPE (to), t);
2290 /* A subroutine of gimplify_modify_expr. Replace a MODIFY_EXPR with
2291 a call to __builtin_memset. In this case we know that the RHS is
2292 a CONSTRUCTOR with an empty element list. */
2294 static enum gimplify_status
2295 gimplify_modify_expr_to_memset (tree *expr_p, tree size, bool want_value)
2297 tree args, t, to, to_ptr;
2299 to = TREE_OPERAND (*expr_p, 0);
2301 args = tree_cons (NULL, size, NULL);
2303 args = tree_cons (NULL, integer_zero_node, args);
2305 to_ptr = build_fold_addr_expr (to);
2306 args = tree_cons (NULL, to_ptr, args);
2307 t = implicit_built_in_decls[BUILT_IN_MEMSET];
2308 t = build_function_call_expr (t, args);
2312 t = build1 (NOP_EXPR, TREE_TYPE (to_ptr), t);
2313 t = build1 (INDIRECT_REF, TREE_TYPE (to), t);
2320 /* A subroutine of gimplify_init_ctor_preeval. Called via walk_tree,
2321 determine, cautiously, if a CONSTRUCTOR overlaps the lhs of an
2322 assignment. Returns non-null if we detect a potential overlap. */
2324 struct gimplify_init_ctor_preeval_data
2326 /* The base decl of the lhs object. May be NULL, in which case we
2327 have to assume the lhs is indirect. */
2330 /* The alias set of the lhs object. */
2335 gimplify_init_ctor_preeval_1 (tree *tp, int *walk_subtrees, void *xdata)
2337 struct gimplify_init_ctor_preeval_data *data
2338 = (struct gimplify_init_ctor_preeval_data *) xdata;
2341 /* If we find the base object, obviously we have overlap. */
2342 if (data->lhs_base_decl == t)
2345 /* If the constructor component is indirect, determine if we have a
2346 potential overlap with the lhs. The only bits of information we
2347 have to go on at this point are addressability and alias sets. */
2348 if (TREE_CODE (t) == INDIRECT_REF
2349 && (!data->lhs_base_decl || TREE_ADDRESSABLE (data->lhs_base_decl))
2350 && alias_sets_conflict_p (data->lhs_alias_set, get_alias_set (t)))
2353 if (IS_TYPE_OR_DECL_P (t))
2358 /* A subroutine of gimplify_init_constructor. Pre-evaluate *EXPR_P,
2359 force values that overlap with the lhs (as described by *DATA)
2360 into temporaries. */
2363 gimplify_init_ctor_preeval (tree *expr_p, tree *pre_p, tree *post_p,
2364 struct gimplify_init_ctor_preeval_data *data)
2366 enum gimplify_status one;
2368 /* If the value is invariant, then there's nothing to pre-evaluate.
2369 But ensure it doesn't have any side-effects since a SAVE_EXPR is
2370 invariant but has side effects and might contain a reference to
2371 the object we're initializing. */
2372 if (TREE_INVARIANT (*expr_p) && !TREE_SIDE_EFFECTS (*expr_p))
2375 /* If the type has non-trivial constructors, we can't pre-evaluate. */
2376 if (TREE_ADDRESSABLE (TREE_TYPE (*expr_p)))
2379 /* Recurse for nested constructors. */
2380 if (TREE_CODE (*expr_p) == CONSTRUCTOR)
2383 for (list = CONSTRUCTOR_ELTS (*expr_p); list ; list = TREE_CHAIN (list))
2384 gimplify_init_ctor_preeval (&TREE_VALUE (list), pre_p, post_p, data);
2388 /* We can't preevaluate if the type contains a placeholder. */
2389 if (type_contains_placeholder_p (TREE_TYPE (*expr_p)))
2392 /* Gimplify the constructor element to something appropriate for the rhs
2393 of a MODIFY_EXPR. Given that we know the lhs is an aggregate, we know
2394 the gimplifier will consider this a store to memory. Doing this
2395 gimplification now means that we won't have to deal with complicated
2396 language-specific trees, nor trees like SAVE_EXPR that can induce
2397 exponential search behavior. */
2398 one = gimplify_expr (expr_p, pre_p, post_p, is_gimple_mem_rhs, fb_rvalue);
2399 if (one == GS_ERROR)
2405 /* If we gimplified to a bare decl, we can be sure that it doesn't overlap
2406 with the lhs, since "a = { .x=a }" doesn't make sense. This will
2407 always be true for all scalars, since is_gimple_mem_rhs insists on a
2408 temporary variable for them. */
2409 if (DECL_P (*expr_p))
2412 /* If this is of variable size, we have no choice but to assume it doesn't
2413 overlap since we can't make a temporary for it. */
2414 if (!TREE_CONSTANT (TYPE_SIZE (TREE_TYPE (*expr_p))))
2417 /* Otherwise, we must search for overlap ... */
2418 if (!walk_tree (expr_p, gimplify_init_ctor_preeval_1, data, NULL))
2421 /* ... and if found, force the value into a temporary. */
2422 *expr_p = get_formal_tmp_var (*expr_p, pre_p);
2425 /* A subroutine of gimplify_init_ctor_eval. Create a loop for
2426 a RANGE_EXPR in a CONSTRUCTOR for an array.
2430 object[var] = value;
2437 We increment var _after_ the loop exit check because we might otherwise
2438 fail if upper == TYPE_MAX_VALUE (type for upper).
2440 Note that we never have to deal with SAVE_EXPRs here, because this has
2441 already been taken care of for us, in gimplify_init_ctor_preeval(). */
2443 static void gimplify_init_ctor_eval (tree, tree, tree *, bool);
2446 gimplify_init_ctor_eval_range (tree object, tree lower, tree upper,
2447 tree value, tree array_elt_type,
2448 tree *pre_p, bool cleared)
2450 tree loop_entry_label, loop_exit_label;
2451 tree var, var_type, cref;
2453 loop_entry_label = create_artificial_label ();
2454 loop_exit_label = create_artificial_label ();
2456 /* Create and initialize the index variable. */
2457 var_type = TREE_TYPE (upper);
2458 var = create_tmp_var (var_type, NULL);
2459 append_to_statement_list (build2 (MODIFY_EXPR, var_type, var, lower), pre_p);
2461 /* Add the loop entry label. */
2462 append_to_statement_list (build1 (LABEL_EXPR,
2467 /* Build the reference. */
2468 cref = build4 (ARRAY_REF, array_elt_type, unshare_expr (object),
2469 var, NULL_TREE, NULL_TREE);
2471 /* If we are a constructor, just call gimplify_init_ctor_eval to do
2472 the store. Otherwise just assign value to the reference. */
2474 if (TREE_CODE (value) == CONSTRUCTOR)
2475 /* NB we might have to call ourself recursively through
2476 gimplify_init_ctor_eval if the value is a constructor. */
2477 gimplify_init_ctor_eval (cref, CONSTRUCTOR_ELTS (value),
2480 append_to_statement_list (build2 (MODIFY_EXPR, TREE_TYPE (cref),
2484 /* We exit the loop when the index var is equal to the upper bound. */
2485 gimplify_and_add (build3 (COND_EXPR, void_type_node,
2486 build2 (EQ_EXPR, boolean_type_node,
2494 /* Otherwise, increment the index var... */
2495 append_to_statement_list (build2 (MODIFY_EXPR, var_type, var,
2496 build2 (PLUS_EXPR, var_type, var,
2497 fold_convert (var_type,
2498 integer_one_node))),
2501 /* ...and jump back to the loop entry. */
2502 append_to_statement_list (build1 (GOTO_EXPR,
2507 /* Add the loop exit label. */
2508 append_to_statement_list (build1 (LABEL_EXPR,
2514 /* A subroutine of gimplify_init_constructor. Generate individual
2515 MODIFY_EXPRs for a CONSTRUCTOR. OBJECT is the LHS against which the
2516 assignments should happen. LIST is the CONSTRUCTOR_ELTS of the
2517 CONSTRUCTOR. CLEARED is true if the entire LHS object has been
2521 gimplify_init_ctor_eval (tree object, tree list, tree *pre_p, bool cleared)
2523 tree array_elt_type = NULL;
2525 if (TREE_CODE (TREE_TYPE (object)) == ARRAY_TYPE)
2526 array_elt_type = TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (object)));
2528 for (; list; list = TREE_CHAIN (list))
2530 tree purpose, value, cref, init;
2532 purpose = TREE_PURPOSE (list);
2533 value = TREE_VALUE (list);
2535 /* NULL values are created above for gimplification errors. */
2539 if (cleared && initializer_zerop (value))
2542 /* ??? Here's to hoping the front end fills in all of the indices,
2543 so we don't have to figure out what's missing ourselves. */
2544 gcc_assert (purpose);
2546 /* If we have a RANGE_EXPR, we have to build a loop to assign the
2548 if (TREE_CODE (purpose) == RANGE_EXPR)
2550 tree lower = TREE_OPERAND (purpose, 0);
2551 tree upper = TREE_OPERAND (purpose, 1);
2553 /* If the lower bound is equal to upper, just treat it as if
2554 upper was the index. */
2555 if (simple_cst_equal (lower, upper))
2559 gimplify_init_ctor_eval_range (object, lower, upper, value,
2560 array_elt_type, pre_p, cleared);
2567 cref = build (ARRAY_REF, array_elt_type, unshare_expr (object),
2568 purpose, NULL_TREE, NULL_TREE);
2571 cref = build (COMPONENT_REF, TREE_TYPE (purpose),
2572 unshare_expr (object), purpose, NULL_TREE);
2574 if (TREE_CODE (value) == CONSTRUCTOR)
2575 gimplify_init_ctor_eval (cref, CONSTRUCTOR_ELTS (value),
2579 init = build (MODIFY_EXPR, TREE_TYPE (cref), cref, value);
2580 gimplify_and_add (init, pre_p);
2585 /* A subroutine of gimplify_modify_expr. Break out elements of a
2586 CONSTRUCTOR used as an initializer into separate MODIFY_EXPRs.
2588 Note that we still need to clear any elements that don't have explicit
2589 initializers, so if not all elements are initialized we keep the
2590 original MODIFY_EXPR, we just remove all of the constructor elements. */
2592 static enum gimplify_status
2593 gimplify_init_constructor (tree *expr_p, tree *pre_p,
2594 tree *post_p, bool want_value)
2597 tree ctor = TREE_OPERAND (*expr_p, 1);
2598 tree type = TREE_TYPE (ctor);
2599 enum gimplify_status ret;
2602 if (TREE_CODE (ctor) != CONSTRUCTOR)
2603 return GS_UNHANDLED;
2605 ret = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p, post_p,
2606 is_gimple_lvalue, fb_lvalue);
2607 if (ret == GS_ERROR)
2609 object = TREE_OPERAND (*expr_p, 0);
2611 elt_list = CONSTRUCTOR_ELTS (ctor);
2614 switch (TREE_CODE (type))
2618 case QUAL_UNION_TYPE:
2621 struct gimplify_init_ctor_preeval_data preeval_data;
2622 HOST_WIDE_INT num_type_elements, num_ctor_elements;
2623 HOST_WIDE_INT num_nonzero_elements, num_nonconstant_elements;
2626 /* Aggregate types must lower constructors to initialization of
2627 individual elements. The exception is that a CONSTRUCTOR node
2628 with no elements indicates zero-initialization of the whole. */
2629 if (elt_list == NULL)
2632 categorize_ctor_elements (ctor, &num_nonzero_elements,
2633 &num_nonconstant_elements,
2634 &num_ctor_elements, &cleared);
2636 /* If a const aggregate variable is being initialized, then it
2637 should never be a lose to promote the variable to be static. */
2638 if (num_nonconstant_elements == 0
2639 && num_nonzero_elements > 1
2640 && TREE_READONLY (object)
2641 && TREE_CODE (object) == VAR_DECL)
2643 DECL_INITIAL (object) = ctor;
2644 TREE_STATIC (object) = 1;
2645 if (!DECL_NAME (object))
2646 DECL_NAME (object) = create_tmp_var_name ("C");
2647 walk_tree (&DECL_INITIAL (object), force_labels_r, NULL, NULL);
2649 /* ??? C++ doesn't automatically append a .<number> to the
2650 assembler name, and even when it does, it looks a FE private
2651 data structures to figure out what that number should be,
2652 which are not set for this variable. I suppose this is
2653 important for local statics for inline functions, which aren't
2654 "local" in the object file sense. So in order to get a unique
2655 TU-local symbol, we must invoke the lhd version now. */
2656 lhd_set_decl_assembler_name (object);
2658 *expr_p = NULL_TREE;
2662 /* If there are "lots" of initialized elements, and all of them
2663 are valid address constants, then the entire initializer can
2664 be dropped to memory, and then memcpy'd out. */
2665 if (num_nonconstant_elements == 0)
2667 HOST_WIDE_INT size = int_size_in_bytes (type);
2670 /* ??? We can still get unbounded array types, at least
2671 from the C++ front end. This seems wrong, but attempt
2672 to work around it for now. */
2675 size = int_size_in_bytes (TREE_TYPE (object));
2677 TREE_TYPE (ctor) = type = TREE_TYPE (object);
2680 /* Find the maximum alignment we can assume for the object. */
2681 /* ??? Make use of DECL_OFFSET_ALIGN. */
2682 if (DECL_P (object))
2683 align = DECL_ALIGN (object);
2685 align = TYPE_ALIGN (type);
2687 if (size > 0 && !can_move_by_pieces (size, align))
2689 tree new = create_tmp_var_raw (type, "C");
2691 gimple_add_tmp_var (new);
2692 TREE_STATIC (new) = 1;
2693 TREE_READONLY (new) = 1;
2694 DECL_INITIAL (new) = ctor;
2695 if (align > DECL_ALIGN (new))
2697 DECL_ALIGN (new) = align;
2698 DECL_USER_ALIGN (new) = 1;
2700 walk_tree (&DECL_INITIAL (new), force_labels_r, NULL, NULL);
2702 TREE_OPERAND (*expr_p, 1) = new;
2704 /* This is no longer an assignment of a CONSTRUCTOR, but
2705 we still may have processing to do on the LHS. So
2706 pretend we didn't do anything here to let that happen. */
2707 return GS_UNHANDLED;
2711 /* If there are "lots" of initialized elements, even discounting
2712 those that are not address constants (and thus *must* be
2713 computed at runtime), then partition the constructor into
2714 constant and non-constant parts. Block copy the constant
2715 parts in, then generate code for the non-constant parts. */
2716 /* TODO. There's code in cp/typeck.c to do this. */
2718 num_type_elements = count_type_elements (TREE_TYPE (ctor));
2720 /* If there are "lots" of zeros, then block clear the object first. */
2721 if (num_type_elements - num_nonzero_elements > CLEAR_RATIO
2722 && num_nonzero_elements < num_type_elements/4)
2725 /* ??? This bit ought not be needed. For any element not present
2726 in the initializer, we should simply set them to zero. Except
2727 we'd need to *find* the elements that are not present, and that
2728 requires trickery to avoid quadratic compile-time behavior in
2729 large cases or excessive memory use in small cases. */
2730 else if (num_ctor_elements < num_type_elements)
2735 /* Zap the CONSTRUCTOR element list, which simplifies this case.
2736 Note that we still have to gimplify, in order to handle the
2737 case of variable sized types. Avoid shared tree structures. */
2738 CONSTRUCTOR_ELTS (ctor) = NULL_TREE;
2739 object = unshare_expr (object);
2740 gimplify_stmt (expr_p);
2741 append_to_statement_list (*expr_p, pre_p);
2744 /* If we have not block cleared the object, or if there are nonzero
2745 elements in the constructor, add assignments to the individual
2746 scalar fields of the object. */
2747 if (!cleared || num_nonzero_elements > 0)
2749 preeval_data.lhs_base_decl = get_base_address (object);
2750 if (!DECL_P (preeval_data.lhs_base_decl))
2751 preeval_data.lhs_base_decl = NULL;
2752 preeval_data.lhs_alias_set = get_alias_set (object);
2754 gimplify_init_ctor_preeval (&TREE_OPERAND (*expr_p, 1),
2755 pre_p, post_p, &preeval_data);
2756 gimplify_init_ctor_eval (object, elt_list, pre_p, cleared);
2759 *expr_p = NULL_TREE;
2767 /* Extract the real and imaginary parts out of the ctor. */
2771 r = TREE_VALUE (elt_list);
2772 elt_list = TREE_CHAIN (elt_list);
2775 i = TREE_VALUE (elt_list);
2776 gcc_assert (!TREE_CHAIN (elt_list));
2779 if (r == NULL || i == NULL)
2781 tree zero = convert (TREE_TYPE (type), integer_zero_node);
2788 /* Complex types have either COMPLEX_CST or COMPLEX_EXPR to
2789 represent creation of a complex value. */
2790 if (TREE_CONSTANT (r) && TREE_CONSTANT (i))
2792 ctor = build_complex (type, r, i);
2793 TREE_OPERAND (*expr_p, 1) = ctor;
2797 ctor = build (COMPLEX_EXPR, type, r, i);
2798 TREE_OPERAND (*expr_p, 1) = ctor;
2799 ret = gimplify_expr (&TREE_OPERAND (*expr_p, 1), pre_p, post_p,
2800 rhs_predicate_for (TREE_OPERAND (*expr_p, 0)),
2807 /* Go ahead and simplify constant constructors to VECTOR_CST. */
2808 if (TREE_CONSTANT (ctor))
2812 /* Even when ctor is constant, it might contain non-*_CST
2813 elements (e.g. { 1.0/0.0 - 1.0/0.0, 0.0 }) and those don't
2814 belong into VECTOR_CST nodes. */
2815 for (tem = elt_list; tem; tem = TREE_CHAIN (tem))
2816 if (! CONSTANT_CLASS_P (TREE_VALUE (tem)))
2821 TREE_OPERAND (*expr_p, 1) = build_vector (type, elt_list);
2826 /* Vector types use CONSTRUCTOR all the way through gimple
2827 compilation as a general initializer. */
2828 for (; elt_list; elt_list = TREE_CHAIN (elt_list))
2830 enum gimplify_status tret;
2831 tret = gimplify_expr (&TREE_VALUE (elt_list), pre_p, post_p,
2832 is_gimple_val, fb_rvalue);
2833 if (tret == GS_ERROR)
2839 /* So how did we get a CONSTRUCTOR for a scalar type? */
2843 if (ret == GS_ERROR)
2845 else if (want_value)
2847 append_to_statement_list (*expr_p, pre_p);
2855 /* Subroutine of gimplify_modify_expr to do simplifications of MODIFY_EXPRs
2856 based on the code of the RHS. We loop for as long as something changes. */
2858 static enum gimplify_status
2859 gimplify_modify_expr_rhs (tree *expr_p, tree *from_p, tree *to_p, tree *pre_p,
2860 tree *post_p, bool want_value)
2862 enum gimplify_status ret = GS_OK;
2864 while (ret != GS_UNHANDLED)
2865 switch (TREE_CODE (*from_p))
2869 /* If we have code like
2873 where the type of "x" is a (possibly cv-qualified variant
2874 of "A"), treat the entire expression as identical to "x".
2875 This kind of code arises in C++ when an object is bound
2876 to a const reference, and if "x" is a TARGET_EXPR we want
2877 to take advantage of the optimization below. */
2878 tree t = fold_indirect_ref (*from_p);
2891 /* If we are initializing something from a TARGET_EXPR, strip the
2892 TARGET_EXPR and initialize it directly, if possible. This can't
2893 be done if the initializer is void, since that implies that the
2894 temporary is set in some non-trivial way.
2896 ??? What about code that pulls out the temp and uses it
2897 elsewhere? I think that such code never uses the TARGET_EXPR as
2898 an initializer. If I'm wrong, we'll abort because the temp won't
2899 have any RTL. In that case, I guess we'll need to replace
2900 references somehow. */
2901 tree init = TARGET_EXPR_INITIAL (*from_p);
2903 if (!VOID_TYPE_P (TREE_TYPE (init)))
2914 /* Remove any COMPOUND_EXPR in the RHS so the following cases will be
2916 gimplify_compound_expr (from_p, pre_p, true);
2921 /* If we're initializing from a CONSTRUCTOR, break this into
2922 individual MODIFY_EXPRs. */
2923 return gimplify_init_constructor (expr_p, pre_p, post_p, want_value);
2926 /* If we're assigning to a non-register type, push the assignment
2927 down into the branches. This is mandatory for ADDRESSABLE types,
2928 since we cannot generate temporaries for such, but it saves a
2929 copy in other cases as well. */
2930 if (!is_gimple_reg_type (TREE_TYPE (*from_p)))
2933 return gimplify_cond_expr (expr_p, pre_p, post_p, *to_p,
2948 /* Gimplify the MODIFY_EXPR node pointed by EXPR_P.
2954 PRE_P points to the list where side effects that must happen before
2955 *EXPR_P should be stored.
2957 POST_P points to the list where side effects that must happen after
2958 *EXPR_P should be stored.
2960 WANT_VALUE is nonzero iff we want to use the value of this expression
2961 in another expression. */
2963 static enum gimplify_status
2964 gimplify_modify_expr (tree *expr_p, tree *pre_p, tree *post_p, bool want_value)
2966 tree *from_p = &TREE_OPERAND (*expr_p, 1);
2967 tree *to_p = &TREE_OPERAND (*expr_p, 0);
2968 enum gimplify_status ret = GS_UNHANDLED;
2970 gcc_assert (TREE_CODE (*expr_p) == MODIFY_EXPR
2971 || TREE_CODE (*expr_p) == INIT_EXPR);
2973 /* The distinction between MODIFY_EXPR and INIT_EXPR is no longer useful. */
2974 if (TREE_CODE (*expr_p) == INIT_EXPR)
2975 TREE_SET_CODE (*expr_p, MODIFY_EXPR);
2977 /* See if any simplifications can be done based on what the RHS is. */
2978 ret = gimplify_modify_expr_rhs (expr_p, from_p, to_p, pre_p, post_p,
2980 if (ret != GS_UNHANDLED)
2983 /* If the value being copied is of variable width, compute the length
2984 of the copy into a WITH_SIZE_EXPR. Note that we need to do this
2985 before gimplifying any of the operands so that we can resolve any
2986 PLACEHOLDER_EXPRs in the size. Also note that the RTL expander uses
2987 the size of the expression to be copied, not of the destination, so
2988 that is what we must here. */
2989 maybe_with_size_expr (from_p);
2991 ret = gimplify_expr (to_p, pre_p, post_p, is_gimple_lvalue, fb_lvalue);
2992 if (ret == GS_ERROR)
2995 ret = gimplify_expr (from_p, pre_p, post_p,
2996 rhs_predicate_for (*to_p), fb_rvalue);
2997 if (ret == GS_ERROR)
3000 /* Now see if the above changed *from_p to something we handle specially. */
3001 ret = gimplify_modify_expr_rhs (expr_p, from_p, to_p, pre_p, post_p,
3003 if (ret != GS_UNHANDLED)
3006 /* If we've got a variable sized assignment between two lvalues (i.e. does
3007 not involve a call), then we can make things a bit more straightforward
3008 by converting the assignment to memcpy or memset. */
3009 if (TREE_CODE (*from_p) == WITH_SIZE_EXPR)
3011 tree from = TREE_OPERAND (*from_p, 0);
3012 tree size = TREE_OPERAND (*from_p, 1);
3014 if (TREE_CODE (from) == CONSTRUCTOR)
3015 return gimplify_modify_expr_to_memset (expr_p, size, want_value);
3016 if (is_gimple_addressable (from))
3019 return gimplify_modify_expr_to_memcpy (expr_p, size, want_value);
3023 if (gimplify_ctxp->into_ssa && is_gimple_reg (*to_p))
3025 /* If we've somehow already got an SSA_NAME on the LHS, then
3026 we're probably modifying it twice. Not good. */
3027 gcc_assert (TREE_CODE (*to_p) != SSA_NAME);
3028 *to_p = make_ssa_name (*to_p, *expr_p);
3033 append_to_statement_list (*expr_p, pre_p);
3041 /* Gimplify a comparison between two variable-sized objects. Do this
3042 with a call to BUILT_IN_MEMCMP. */
3044 static enum gimplify_status
3045 gimplify_variable_sized_compare (tree *expr_p)
3047 tree op0 = TREE_OPERAND (*expr_p, 0);
3048 tree op1 = TREE_OPERAND (*expr_p, 1);
3051 t = TYPE_SIZE_UNIT (TREE_TYPE (op0));
3052 t = unshare_expr (t);
3053 t = SUBSTITUTE_PLACEHOLDER_IN_EXPR (t, op0);
3054 args = tree_cons (NULL, t, NULL);
3055 t = build_fold_addr_expr (op1);
3056 args = tree_cons (NULL, t, args);
3057 dest = build_fold_addr_expr (op0);
3058 args = tree_cons (NULL, dest, args);
3059 t = implicit_built_in_decls[BUILT_IN_MEMCMP];
3060 t = build_function_call_expr (t, args);
3062 = build (TREE_CODE (*expr_p), TREE_TYPE (*expr_p), t, integer_zero_node);
3067 /* Gimplify TRUTH_ANDIF_EXPR and TRUTH_ORIF_EXPR expressions. EXPR_P
3068 points to the expression to gimplify.
3070 Expressions of the form 'a && b' are gimplified to:
3072 a && b ? true : false
3074 gimplify_cond_expr will do the rest.
3076 PRE_P points to the list where side effects that must happen before
3077 *EXPR_P should be stored. */
3079 static enum gimplify_status
3080 gimplify_boolean_expr (tree *expr_p)
3082 /* Preserve the original type of the expression. */
3083 tree type = TREE_TYPE (*expr_p);
3085 *expr_p = build (COND_EXPR, type, *expr_p,
3086 convert (type, boolean_true_node),
3087 convert (type, boolean_false_node));
3092 /* Gimplifies an expression sequence. This function gimplifies each
3093 expression and re-writes the original expression with the last
3094 expression of the sequence in GIMPLE form.
3096 PRE_P points to the list where the side effects for all the
3097 expressions in the sequence will be emitted.
3099 WANT_VALUE is true when the result of the last COMPOUND_EXPR is used. */
3100 /* ??? Should rearrange to share the pre-queue with all the indirect
3101 invocations of gimplify_expr. Would probably save on creations
3102 of statement_list nodes. */
3104 static enum gimplify_status
3105 gimplify_compound_expr (tree *expr_p, tree *pre_p, bool want_value)
3111 tree *sub_p = &TREE_OPERAND (t, 0);
3113 if (TREE_CODE (*sub_p) == COMPOUND_EXPR)
3114 gimplify_compound_expr (sub_p, pre_p, false);
3116 gimplify_stmt (sub_p);
3117 append_to_statement_list (*sub_p, pre_p);
3119 t = TREE_OPERAND (t, 1);
3121 while (TREE_CODE (t) == COMPOUND_EXPR);
3128 gimplify_stmt (expr_p);
3133 /* Gimplifies a statement list. These may be created either by an
3134 enlightened front-end, or by shortcut_cond_expr. */
3136 static enum gimplify_status
3137 gimplify_statement_list (tree *expr_p)
3139 tree_stmt_iterator i = tsi_start (*expr_p);
3141 while (!tsi_end_p (i))
3145 gimplify_stmt (tsi_stmt_ptr (i));
3150 else if (TREE_CODE (t) == STATEMENT_LIST)
3152 tsi_link_before (&i, t, TSI_SAME_STMT);
3162 /* Gimplify a SAVE_EXPR node. EXPR_P points to the expression to
3163 gimplify. After gimplification, EXPR_P will point to a new temporary
3164 that holds the original value of the SAVE_EXPR node.
3166 PRE_P points to the list where side effects that must happen before
3167 *EXPR_P should be stored. */
3169 static enum gimplify_status
3170 gimplify_save_expr (tree *expr_p, tree *pre_p, tree *post_p)
3172 enum gimplify_status ret = GS_ALL_DONE;
3175 gcc_assert (TREE_CODE (*expr_p) == SAVE_EXPR);
3176 val = TREE_OPERAND (*expr_p, 0);
3178 /* If the SAVE_EXPR has not been resolved, then evaluate it once. */
3179 if (!SAVE_EXPR_RESOLVED_P (*expr_p))
3181 /* The operand may be a void-valued expression such as SAVE_EXPRs
3182 generated by the Java frontend for class initialization. It is
3183 being executed only for its side-effects. */
3184 if (TREE_TYPE (val) == void_type_node)
3186 ret = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p, post_p,
3187 is_gimple_stmt, fb_none);
3188 append_to_statement_list (TREE_OPERAND (*expr_p, 0), pre_p);
3192 val = get_initialized_tmp_var (val, pre_p, post_p);
3194 TREE_OPERAND (*expr_p, 0) = val;
3195 SAVE_EXPR_RESOLVED_P (*expr_p) = 1;
3203 /* Re-write the ADDR_EXPR node pointed by EXPR_P
3210 PRE_P points to the list where side effects that must happen before
3211 *EXPR_P should be stored.
3213 POST_P points to the list where side effects that must happen after
3214 *EXPR_P should be stored. */
3216 static enum gimplify_status
3217 gimplify_addr_expr (tree *expr_p, tree *pre_p, tree *post_p)
3219 tree expr = *expr_p;
3220 tree op0 = TREE_OPERAND (expr, 0);
3221 enum gimplify_status ret;
3223 switch (TREE_CODE (op0))
3226 case MISALIGNED_INDIRECT_REF:
3228 /* Check if we are dealing with an expression of the form '&*ptr'.
3229 While the front end folds away '&*ptr' into 'ptr', these
3230 expressions may be generated internally by the compiler (e.g.,
3231 builtins like __builtin_va_end). */
3232 /* Caution: the silent array decomposition semantics we allow for
3233 ADDR_EXPR means we can't always discard the pair. */
3234 /* Gimplification of the ADDR_EXPR operand may drop
3235 cv-qualification conversions, so make sure we add them if
3238 tree op00 = TREE_OPERAND (op0, 0);
3239 tree t_expr = TREE_TYPE (expr);
3240 tree t_op00 = TREE_TYPE (op00);
3242 if (!lang_hooks.types_compatible_p (t_expr, t_op00))
3244 #ifdef ENABLE_CHECKING
3245 tree t_op0 = TREE_TYPE (op0);
3246 gcc_assert (POINTER_TYPE_P (t_expr)
3247 && cpt_same_type (TREE_CODE (t_op0) == ARRAY_TYPE
3248 ? TREE_TYPE (t_op0) : t_op0,
3250 && POINTER_TYPE_P (t_op00)
3251 && cpt_same_type (t_op0, TREE_TYPE (t_op00)));
3253 op00 = fold_convert (TREE_TYPE (expr), op00);
3260 case VIEW_CONVERT_EXPR:
3261 /* Take the address of our operand and then convert it to the type of
3264 ??? The interactions of VIEW_CONVERT_EXPR and aliasing is not at
3265 all clear. The impact of this transformation is even less clear. */
3267 /* If the operand is a useless conversion, look through it. Doing so
3268 guarantees that the ADDR_EXPR and its operand will remain of the
3270 if (tree_ssa_useless_type_conversion (TREE_OPERAND (op0, 0)))
3271 op0 = TREE_OPERAND (op0, 0);
3273 *expr_p = fold_convert (TREE_TYPE (expr),
3274 build_fold_addr_expr (TREE_OPERAND (op0, 0)));
3279 /* We use fb_either here because the C frontend sometimes takes
3280 the address of a call that returns a struct; see
3281 gcc.dg/c99-array-lval-1.c. The gimplifier will correctly make
3282 the implied temporary explicit. */
3283 ret = gimplify_expr (&TREE_OPERAND (expr, 0), pre_p, post_p,
3284 is_gimple_addressable, fb_either);
3285 if (ret != GS_ERROR)
3287 op0 = TREE_OPERAND (expr, 0);
3289 /* For various reasons, the gimplification of the expression
3290 may have made a new INDIRECT_REF. */
3291 if (TREE_CODE (op0) == INDIRECT_REF)
3292 goto do_indirect_ref;
3294 /* Make sure TREE_INVARIANT, TREE_CONSTANT, and TREE_SIDE_EFFECTS
3296 recompute_tree_invarant_for_addr_expr (expr);
3298 /* Mark the RHS addressable. */
3299 lang_hooks.mark_addressable (TREE_OPERAND (expr, 0));
3307 /* Gimplify the operands of an ASM_EXPR. Input operands should be a gimple
3308 value; output operands should be a gimple lvalue. */
3310 static enum gimplify_status
3311 gimplify_asm_expr (tree *expr_p, tree *pre_p, tree *post_p)
3313 tree expr = *expr_p;
3314 int noutputs = list_length (ASM_OUTPUTS (expr));
3315 const char **oconstraints
3316 = (const char **) alloca ((noutputs) * sizeof (const char *));
3319 const char *constraint;
3320 bool allows_mem, allows_reg, is_inout;
3321 enum gimplify_status ret, tret;
3324 for (i = 0, link = ASM_OUTPUTS (expr); link; ++i, link = TREE_CHAIN (link))
3326 size_t constraint_len;
3327 oconstraints[i] = constraint
3328 = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (link)));
3329 constraint_len = strlen (constraint);
3330 if (constraint_len == 0)
3333 parse_output_constraint (&constraint, i, 0, 0,
3334 &allows_mem, &allows_reg, &is_inout);
3336 if (!allows_reg && allows_mem)
3337 lang_hooks.mark_addressable (TREE_VALUE (link));
3339 tret = gimplify_expr (&TREE_VALUE (link), pre_p, post_p,
3340 is_inout ? is_gimple_min_lval : is_gimple_lvalue,
3341 fb_lvalue | fb_mayfail);
3342 if (tret == GS_ERROR)
3344 error ("invalid lvalue in asm output %d", i);
3350 /* An input/output operand. To give the optimizers more
3351 flexibility, split it into separate input and output
3356 /* Turn the in/out constraint into an output constraint. */
3357 char *p = xstrdup (constraint);
3359 TREE_VALUE (TREE_PURPOSE (link)) = build_string (constraint_len, p);
3361 /* And add a matching input constraint. */
3364 sprintf (buf, "%d", i);
3366 /* If there are multiple alternatives in the constraint,
3367 handle each of them individually. Those that allow register
3368 will be replaced with operand number, the others will stay
3370 if (strchr (p, ',') != NULL)
3372 size_t len = 0, buflen = strlen (buf);
3373 char *beg, *end, *str, *dst;
3377 end = strchr (beg, ',');
3379 end = strchr (beg, '\0');
3380 if ((size_t) (end - beg) < buflen)
3383 len += end - beg + 1;
3391 for (beg = p + 1, dst = str;;)
3394 bool mem_p, reg_p, inout_p;
3396 end = strchr (beg, ',');
3401 parse_output_constraint (&tem, i, 0, 0,
3402 &mem_p, ®_p, &inout_p);
3407 memcpy (dst, buf, buflen);
3416 memcpy (dst, beg, len);
3425 input = build_string (dst - str, str);
3428 input = build_string (strlen (buf), buf);
3431 input = build_string (constraint_len - 1, constraint + 1);
3435 input = build_tree_list (build_tree_list (NULL_TREE, input),
3436 unshare_expr (TREE_VALUE (link)));
3437 ASM_INPUTS (expr) = chainon (ASM_INPUTS (expr), input);
3441 for (link = ASM_INPUTS (expr); link; ++i, link = TREE_CHAIN (link))
3444 = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (link)));
3445 parse_input_constraint (&constraint, 0, 0, noutputs, 0,
3446 oconstraints, &allows_mem, &allows_reg);
3448 /* If the operand is a memory input, it should be an lvalue. */
3449 if (!allows_reg && allows_mem)
3451 lang_hooks.mark_addressable (TREE_VALUE (link));
3452 tret = gimplify_expr (&TREE_VALUE (link), pre_p, post_p,
3453 is_gimple_lvalue, fb_lvalue | fb_mayfail);
3454 if (tret == GS_ERROR)
3456 error ("memory input %d is not directly addressable", i);
3462 tret = gimplify_expr (&TREE_VALUE (link), pre_p, post_p,
3463 is_gimple_asm_val, fb_rvalue);
3464 if (tret == GS_ERROR)
3472 /* Gimplify a CLEANUP_POINT_EXPR. Currently this works by adding
3473 WITH_CLEANUP_EXPRs to the prequeue as we encounter cleanups while
3474 gimplifying the body, and converting them to TRY_FINALLY_EXPRs when we
3475 return to this function.
3477 FIXME should we complexify the prequeue handling instead? Or use flags
3478 for all the cleanups and let the optimizer tighten them up? The current
3479 code seems pretty fragile; it will break on a cleanup within any
3480 non-conditional nesting. But any such nesting would be broken, anyway;
3481 we can't write a TRY_FINALLY_EXPR that starts inside a nesting construct
3482 and continues out of it. We can do that at the RTL level, though, so
3483 having an optimizer to tighten up try/finally regions would be a Good
3486 static enum gimplify_status
3487 gimplify_cleanup_point_expr (tree *expr_p, tree *pre_p)
3489 tree_stmt_iterator iter;
3492 tree temp = voidify_wrapper_expr (*expr_p, NULL);
3494 /* We only care about the number of conditions between the innermost
3495 CLEANUP_POINT_EXPR and the cleanup. So save and reset the count. */
3496 int old_conds = gimplify_ctxp->conditions;
3497 gimplify_ctxp->conditions = 0;
3499 body = TREE_OPERAND (*expr_p, 0);
3500 gimplify_to_stmt_list (&body);
3502 gimplify_ctxp->conditions = old_conds;
3504 for (iter = tsi_start (body); !tsi_end_p (iter); )
3506 tree *wce_p = tsi_stmt_ptr (iter);
3509 if (TREE_CODE (wce) == WITH_CLEANUP_EXPR)
3511 if (tsi_one_before_end_p (iter))
3513 tsi_link_before (&iter, TREE_OPERAND (wce, 0), TSI_SAME_STMT);
3520 enum tree_code code;
3522 if (CLEANUP_EH_ONLY (wce))
3523 code = TRY_CATCH_EXPR;
3525 code = TRY_FINALLY_EXPR;
3527 sl = tsi_split_statement_list_after (&iter);
3528 tfe = build (code, void_type_node, sl, NULL_TREE);
3529 append_to_statement_list (TREE_OPERAND (wce, 0),
3530 &TREE_OPERAND (tfe, 1));
3532 iter = tsi_start (sl);
3542 append_to_statement_list (body, pre_p);
3552 /* Insert a cleanup marker for gimplify_cleanup_point_expr. CLEANUP
3553 is the cleanup action required. */
3556 gimple_push_cleanup (tree var, tree cleanup, bool eh_only, tree *pre_p)
3560 /* Errors can result in improperly nested cleanups. Which results in
3561 confusion when trying to resolve the WITH_CLEANUP_EXPR. */
3562 if (errorcount || sorrycount)
3565 if (gimple_conditional_context ())
3567 /* If we're in a conditional context, this is more complex. We only
3568 want to run the cleanup if we actually ran the initialization that
3569 necessitates it, but we want to run it after the end of the
3570 conditional context. So we wrap the try/finally around the
3571 condition and use a flag to determine whether or not to actually
3572 run the destructor. Thus
3576 becomes (approximately)
3580 if (test) { A::A(temp); flag = 1; val = f(temp); }
3583 if (flag) A::~A(temp);
3588 tree flag = create_tmp_var (boolean_type_node, "cleanup");
3589 tree ffalse = build (MODIFY_EXPR, void_type_node, flag,
3590 boolean_false_node);
3591 tree ftrue = build (MODIFY_EXPR, void_type_node, flag,
3593 cleanup = build (COND_EXPR, void_type_node, flag, cleanup, NULL);
3594 wce = build (WITH_CLEANUP_EXPR, void_type_node, cleanup);
3595 append_to_statement_list (ffalse, &gimplify_ctxp->conditional_cleanups);
3596 append_to_statement_list (wce, &gimplify_ctxp->conditional_cleanups);
3597 append_to_statement_list (ftrue, pre_p);
3599 /* Because of this manipulation, and the EH edges that jump
3600 threading cannot redirect, the temporary (VAR) will appear
3601 to be used uninitialized. Don't warn. */
3602 TREE_NO_WARNING (var) = 1;
3606 wce = build (WITH_CLEANUP_EXPR, void_type_node, cleanup);
3607 CLEANUP_EH_ONLY (wce) = eh_only;
3608 append_to_statement_list (wce, pre_p);
3611 gimplify_stmt (&TREE_OPERAND (wce, 0));
3614 /* Gimplify a TARGET_EXPR which doesn't appear on the rhs of an INIT_EXPR. */
3616 static enum gimplify_status
3617 gimplify_target_expr (tree *expr_p, tree *pre_p, tree *post_p)
3619 tree targ = *expr_p;
3620 tree temp = TARGET_EXPR_SLOT (targ);
3621 tree init = TARGET_EXPR_INITIAL (targ);
3622 enum gimplify_status ret;
3626 /* TARGET_EXPR temps aren't part of the enclosing block, so add it
3627 to the temps list. */
3628 gimple_add_tmp_var (temp);
3630 /* If TARGET_EXPR_INITIAL is void, then the mere evaluation of the
3631 expression is supposed to initialize the slot. */
3632 if (VOID_TYPE_P (TREE_TYPE (init)))
3633 ret = gimplify_expr (&init, pre_p, post_p, is_gimple_stmt, fb_none);
3636 /* Special handling for BIND_EXPR can result in fewer temps. */
3638 if (TREE_CODE (init) == BIND_EXPR)
3639 gimplify_bind_expr (&init, temp, pre_p);
3642 init = build (MODIFY_EXPR, void_type_node, temp, init);
3643 ret = gimplify_expr (&init, pre_p, post_p, is_gimple_stmt,
3647 if (ret == GS_ERROR)
3649 append_to_statement_list (init, pre_p);
3651 /* If needed, push the cleanup for the temp. */
3652 if (TARGET_EXPR_CLEANUP (targ))
3654 gimplify_stmt (&TARGET_EXPR_CLEANUP (targ));
3655 gimple_push_cleanup (temp, TARGET_EXPR_CLEANUP (targ),
3656 CLEANUP_EH_ONLY (targ), pre_p);
3659 /* Only expand this once. */
3660 TREE_OPERAND (targ, 3) = init;
3661 TARGET_EXPR_INITIAL (targ) = NULL_TREE;
3664 /* We should have expanded this before. */
3665 gcc_assert (DECL_SEEN_IN_BIND_EXPR_P (temp));
3671 /* Gimplification of expression trees. */
3673 /* Gimplify an expression which appears at statement context; usually, this
3674 means replacing it with a suitably gimple STATEMENT_LIST. */
3677 gimplify_stmt (tree *stmt_p)
3679 gimplify_expr (stmt_p, NULL, NULL, is_gimple_stmt, fb_none);
3682 /* Similarly, but force the result to be a STATEMENT_LIST. */
3685 gimplify_to_stmt_list (tree *stmt_p)
3687 gimplify_stmt (stmt_p);
3689 *stmt_p = alloc_stmt_list ();
3690 else if (TREE_CODE (*stmt_p) != STATEMENT_LIST)
3693 *stmt_p = alloc_stmt_list ();
3694 append_to_statement_list (t, stmt_p);
3699 /* Gimplifies the expression tree pointed by EXPR_P. Return 0 if
3700 gimplification failed.
3702 PRE_P points to the list where side effects that must happen before
3703 EXPR should be stored.
3705 POST_P points to the list where side effects that must happen after
3706 EXPR should be stored, or NULL if there is no suitable list. In
3707 that case, we copy the result to a temporary, emit the
3708 post-effects, and then return the temporary.
3710 GIMPLE_TEST_F points to a function that takes a tree T and
3711 returns nonzero if T is in the GIMPLE form requested by the
3712 caller. The GIMPLE predicates are in tree-gimple.c.
3714 This test is used twice. Before gimplification, the test is
3715 invoked to determine whether *EXPR_P is already gimple enough. If
3716 that fails, *EXPR_P is gimplified according to its code and
3717 GIMPLE_TEST_F is called again. If the test still fails, then a new
3718 temporary variable is created and assigned the value of the
3719 gimplified expression.
3721 FALLBACK tells the function what sort of a temporary we want. If the 1
3722 bit is set, an rvalue is OK. If the 2 bit is set, an lvalue is OK.
3723 If both are set, either is OK, but an lvalue is preferable.
3725 The return value is either GS_ERROR or GS_ALL_DONE, since this function
3726 iterates until solution. */
3728 enum gimplify_status
3729 gimplify_expr (tree *expr_p, tree *pre_p, tree *post_p,
3730 bool (* gimple_test_f) (tree), fallback_t fallback)
3733 tree internal_pre = NULL_TREE;
3734 tree internal_post = NULL_TREE;
3736 int is_statement = (pre_p == NULL);
3737 location_t saved_location;
3738 enum gimplify_status ret;
3740 save_expr = *expr_p;
3741 if (save_expr == NULL_TREE)
3744 /* We used to check the predicate here and return immediately if it
3745 succeeds. This is wrong; the design is for gimplification to be
3746 idempotent, and for the predicates to only test for valid forms, not
3747 whether they are fully simplified. */
3749 /* Set up our internal queues if needed. */
3751 pre_p = &internal_pre;
3753 post_p = &internal_post;
3755 saved_location = input_location;
3756 if (save_expr != error_mark_node
3757 && EXPR_HAS_LOCATION (*expr_p))
3758 input_location = EXPR_LOCATION (*expr_p);
3760 /* Loop over the specific gimplifiers until the toplevel node
3761 remains the same. */
3764 /* Strip away as many useless type conversions as possible
3766 STRIP_USELESS_TYPE_CONVERSION (*expr_p);
3768 /* Remember the expr. */
3769 save_expr = *expr_p;
3771 /* Die, die, die, my darling. */
3772 if (save_expr == error_mark_node
3773 || (TREE_TYPE (save_expr)
3774 && TREE_TYPE (save_expr) == error_mark_node))
3780 /* Do any language-specific gimplification. */
3781 ret = lang_hooks.gimplify_expr (expr_p, pre_p, post_p);
3784 if (*expr_p == NULL_TREE)
3786 if (*expr_p != save_expr)
3789 else if (ret != GS_UNHANDLED)
3793 switch (TREE_CODE (*expr_p))
3795 /* First deal with the special cases. */
3797 case POSTINCREMENT_EXPR:
3798 case POSTDECREMENT_EXPR:
3799 case PREINCREMENT_EXPR:
3800 case PREDECREMENT_EXPR:
3801 ret = gimplify_self_mod_expr (expr_p, pre_p, post_p,
3802 fallback != fb_none);
3806 case ARRAY_RANGE_REF:
3810 case VIEW_CONVERT_EXPR:
3811 ret = gimplify_compound_lval (expr_p, pre_p, post_p,
3812 fallback ? fallback : fb_rvalue);
3816 ret = gimplify_cond_expr (expr_p, pre_p, post_p, NULL_TREE,
3818 /* C99 code may assign to an array in a structure value of a
3819 conditional expression, and this has undefined behavior
3820 only on execution, so create a temporary if an lvalue is
3822 if (fallback == fb_lvalue)
3824 *expr_p = get_initialized_tmp_var (*expr_p, pre_p, post_p);
3825 lang_hooks.mark_addressable (*expr_p);
3830 ret = gimplify_call_expr (expr_p, pre_p, fallback != fb_none);
3831 /* C99 code may assign to an array in a structure returned
3832 from a function, and this has undefined behavior only on
3833 execution, so create a temporary if an lvalue is
3835 if (fallback == fb_lvalue)
3837 *expr_p = get_initialized_tmp_var (*expr_p, pre_p, post_p);
3838 lang_hooks.mark_addressable (*expr_p);
3846 ret = gimplify_compound_expr (expr_p, pre_p, fallback != fb_none);
3851 ret = gimplify_modify_expr (expr_p, pre_p, post_p,
3852 fallback != fb_none);
3855 case TRUTH_ANDIF_EXPR:
3856 case TRUTH_ORIF_EXPR:
3857 ret = gimplify_boolean_expr (expr_p);
3860 case TRUTH_NOT_EXPR:
3861 TREE_OPERAND (*expr_p, 0)
3862 = gimple_boolify (TREE_OPERAND (*expr_p, 0));
3863 ret = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p, post_p,
3864 is_gimple_val, fb_rvalue);
3865 recalculate_side_effects (*expr_p);
3869 ret = gimplify_addr_expr (expr_p, pre_p, post_p);
3873 ret = gimplify_va_arg_expr (expr_p, pre_p, post_p);
3878 if (IS_EMPTY_STMT (*expr_p))
3884 if (VOID_TYPE_P (TREE_TYPE (*expr_p))
3885 || fallback == fb_none)
3887 /* Just strip a conversion to void (or in void context) and
3889 *expr_p = TREE_OPERAND (*expr_p, 0);
3893 ret = gimplify_conversion (expr_p);
3894 if (ret == GS_ERROR)
3896 if (*expr_p != save_expr)
3900 case FIX_TRUNC_EXPR:
3902 case FIX_FLOOR_EXPR:
3903 case FIX_ROUND_EXPR:
3904 /* unary_expr: ... | '(' cast ')' val | ... */
3905 ret = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p, post_p,
3906 is_gimple_val, fb_rvalue);
3907 recalculate_side_effects (*expr_p);
3911 *expr_p = fold_indirect_ref (*expr_p);
3912 if (*expr_p != save_expr)
3914 /* else fall through. */
3915 case ALIGN_INDIRECT_REF:
3916 case MISALIGNED_INDIRECT_REF:
3917 ret = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p, post_p,
3918 is_gimple_reg, fb_rvalue);
3919 recalculate_side_effects (*expr_p);
3922 /* Constants need not be gimplified. */
3932 /* If we require an lvalue, such as for ADDR_EXPR, retain the
3933 CONST_DECL node. Otherwise the decl is replaceable by its
3935 /* ??? Should be == fb_lvalue, but ADDR_EXPR passes fb_either. */
3936 if (fallback & fb_lvalue)
3939 *expr_p = DECL_INITIAL (*expr_p);
3943 ret = gimplify_decl_expr (expr_p);
3947 /* FIXME make this a decl. */
3952 ret = gimplify_bind_expr (expr_p, NULL, pre_p);
3956 ret = gimplify_loop_expr (expr_p, pre_p);
3960 ret = gimplify_switch_expr (expr_p, pre_p);
3964 ret = gimplify_exit_expr (expr_p);
3968 /* If the target is not LABEL, then it is a computed jump
3969 and the target needs to be gimplified. */
3970 if (TREE_CODE (GOTO_DESTINATION (*expr_p)) != LABEL_DECL)
3971 ret = gimplify_expr (&GOTO_DESTINATION (*expr_p), pre_p,
3972 NULL, is_gimple_val, fb_rvalue);
3977 gcc_assert (decl_function_context (LABEL_EXPR_LABEL (*expr_p))
3978 == current_function_decl);
3981 case CASE_LABEL_EXPR:
3982 ret = gimplify_case_label_expr (expr_p);
3986 ret = gimplify_return_expr (*expr_p, pre_p);
3990 /* Don't reduce this in place; let gimplify_init_constructor work its
3991 magic. Buf if we're just elaborating this for side effects, just
3992 gimplify any element that has side-effects. */
3993 if (fallback == fb_none)
3995 for (tmp = CONSTRUCTOR_ELTS (*expr_p); tmp;
3996 tmp = TREE_CHAIN (tmp))
3997 if (TREE_SIDE_EFFECTS (TREE_VALUE (tmp)))
3998 gimplify_expr (&TREE_VALUE (tmp), pre_p, post_p,
3999 gimple_test_f, fallback);
4001 *expr_p = NULL_TREE;
4007 /* The following are special cases that are not handled by the
4008 original GIMPLE grammar. */
4010 /* SAVE_EXPR nodes are converted into a GIMPLE identifier and
4013 ret = gimplify_save_expr (expr_p, pre_p, post_p);
4018 enum gimplify_status r0, r1, r2;
4020 r0 = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p, post_p,
4021 is_gimple_lvalue, fb_either);
4022 r1 = gimplify_expr (&TREE_OPERAND (*expr_p, 1), pre_p, post_p,
4023 is_gimple_val, fb_rvalue);
4024 r2 = gimplify_expr (&TREE_OPERAND (*expr_p, 2), pre_p, post_p,
4025 is_gimple_val, fb_rvalue);
4026 recalculate_side_effects (*expr_p);
4028 ret = MIN (r0, MIN (r1, r2));
4032 case NON_LVALUE_EXPR:
4033 /* This should have been stripped above. */
4037 ret = gimplify_asm_expr (expr_p, pre_p, post_p);
4040 case TRY_FINALLY_EXPR:
4041 case TRY_CATCH_EXPR:
4042 gimplify_to_stmt_list (&TREE_OPERAND (*expr_p, 0));
4043 gimplify_to_stmt_list (&TREE_OPERAND (*expr_p, 1));
4047 case CLEANUP_POINT_EXPR:
4048 ret = gimplify_cleanup_point_expr (expr_p, pre_p);
4052 ret = gimplify_target_expr (expr_p, pre_p, post_p);
4056 gimplify_to_stmt_list (&CATCH_BODY (*expr_p));
4060 case EH_FILTER_EXPR:
4061 gimplify_to_stmt_list (&EH_FILTER_FAILURE (*expr_p));
4067 enum gimplify_status r0, r1;
4068 r0 = gimplify_expr (&OBJ_TYPE_REF_OBJECT (*expr_p), pre_p, post_p,
4069 is_gimple_val, fb_rvalue);
4070 r1 = gimplify_expr (&OBJ_TYPE_REF_EXPR (*expr_p), pre_p, post_p,
4071 is_gimple_val, fb_rvalue);
4077 /* We get here when taking the address of a label. We mark
4078 the label as "forced"; meaning it can never be removed and
4079 it is a potential target for any computed goto. */
4080 FORCED_LABEL (*expr_p) = 1;
4084 case STATEMENT_LIST:
4085 ret = gimplify_statement_list (expr_p);
4088 case WITH_SIZE_EXPR:
4090 enum gimplify_status r0, r1;
4091 r0 = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p,
4092 post_p == &internal_post ? NULL : post_p,
4093 gimple_test_f, fallback);
4094 r1 = gimplify_expr (&TREE_OPERAND (*expr_p, 1), pre_p, post_p,
4095 is_gimple_val, fb_rvalue);
4100 /* ??? If this is a local variable, and it has not been seen in any
4101 outer BIND_EXPR, then it's probably the result of a duplicate
4102 declaration, for which we've already issued an error. It would
4103 be really nice if the front end wouldn't leak these at all.
4104 Currently the only known culprit is C++ destructors, as seen
4105 in g++.old-deja/g++.jason/binding.C. */
4107 if (!TREE_STATIC (tmp) && !DECL_EXTERNAL (tmp)
4108 && decl_function_context (tmp) == current_function_decl
4109 && !DECL_SEEN_IN_BIND_EXPR_P (tmp))
4111 gcc_assert (errorcount || sorrycount);
4120 /* If this is a local variable sized decl, it must be accessed
4121 indirectly. Perform that substitution. */
4122 if (DECL_VALUE_EXPR (tmp))
4124 *expr_p = unshare_expr (DECL_VALUE_EXPR (tmp));
4133 /* Allow callbacks into the gimplifier during optimization. */
4138 switch (TREE_CODE_CLASS (TREE_CODE (*expr_p)))
4140 case tcc_comparison:
4141 /* If this is a comparison of objects of aggregate type,
4142 handle it specially (by converting to a call to
4143 memcmp). It would be nice to only have to do this
4144 for variable-sized objects, but then we'd have to
4145 allow the same nest of reference nodes we allow for
4146 MODIFY_EXPR and that's too complex. */
4147 if (!AGGREGATE_TYPE_P (TREE_TYPE (TREE_OPERAND (*expr_p, 1))))
4149 ret = gimplify_variable_sized_compare (expr_p);
4152 /* If *EXPR_P does not need to be special-cased, handle it
4153 according to its class. */
4155 ret = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p,
4156 post_p, is_gimple_val, fb_rvalue);
4162 enum gimplify_status r0, r1;
4164 r0 = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p,
4165 post_p, is_gimple_val, fb_rvalue);
4166 r1 = gimplify_expr (&TREE_OPERAND (*expr_p, 1), pre_p,
4167 post_p, is_gimple_val, fb_rvalue);
4173 case tcc_declaration:
4176 goto dont_recalculate;
4179 gcc_assert (TREE_CODE (*expr_p) == TRUTH_AND_EXPR
4180 || TREE_CODE (*expr_p) == TRUTH_OR_EXPR
4181 || TREE_CODE (*expr_p) == TRUTH_XOR_EXPR);
4185 recalculate_side_effects (*expr_p);
4190 /* If we replaced *expr_p, gimplify again. */
4191 if (ret == GS_OK && (*expr_p == NULL || *expr_p == save_expr))
4194 while (ret == GS_OK);
4196 /* If we encountered an error_mark somewhere nested inside, either
4197 stub out the statement or propagate the error back out. */
4198 if (ret == GS_ERROR)
4205 /* This was only valid as a return value from the langhook, which
4206 we handled. Make sure it doesn't escape from any other context. */
4207 gcc_assert (ret != GS_UNHANDLED);
4209 if (fallback == fb_none && *expr_p && !is_gimple_stmt (*expr_p))
4211 /* We aren't looking for a value, and we don't have a valid
4212 statement. If it doesn't have side-effects, throw it away. */
4213 if (!TREE_SIDE_EFFECTS (*expr_p))
4215 else if (!TREE_THIS_VOLATILE (*expr_p))
4217 /* This is probably a _REF that contains something nested that
4218 has side effects. Recurse through the operands to find it. */
4219 enum tree_code code = TREE_CODE (*expr_p);
4224 case REALPART_EXPR: case IMAGPART_EXPR:
4225 gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p, post_p,
4226 gimple_test_f, fallback);
4229 case ARRAY_REF: case ARRAY_RANGE_REF:
4230 gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p, post_p,
4231 gimple_test_f, fallback);
4232 gimplify_expr (&TREE_OPERAND (*expr_p, 1), pre_p, post_p,
4233 gimple_test_f, fallback);
4237 /* Anything else with side-effects must be converted to
4238 a valid statement before we get here. */
4244 else if (COMPLETE_TYPE_P (TREE_TYPE (*expr_p)))
4246 /* Historically, the compiler has treated a bare
4247 reference to a volatile lvalue as forcing a load. */
4248 tree tmp = create_tmp_var (TREE_TYPE (*expr_p), "vol");
4249 *expr_p = build (MODIFY_EXPR, TREE_TYPE (tmp), tmp, *expr_p);
4252 /* We can't do anything useful with a volatile reference to
4253 incomplete type, so just throw it away. */
4257 /* If we are gimplifying at the statement level, we're done. Tack
4258 everything together and replace the original statement with the
4260 if (fallback == fb_none || is_statement)
4262 if (internal_pre || internal_post)
4264 append_to_statement_list (*expr_p, &internal_pre);
4265 append_to_statement_list (internal_post, &internal_pre);
4266 annotate_all_with_locus (&internal_pre, input_location);
4267 *expr_p = internal_pre;
4271 else if (TREE_CODE (*expr_p) == STATEMENT_LIST)
4272 annotate_all_with_locus (expr_p, input_location);
4274 annotate_one_with_locus (*expr_p, input_location);
4278 /* Otherwise we're gimplifying a subexpression, so the resulting value is
4281 /* If it's sufficiently simple already, we're done. Unless we are
4282 handling some post-effects internally; if that's the case, we need to
4283 copy into a temp before adding the post-effects to the tree. */
4284 if (!internal_post && (*gimple_test_f) (*expr_p))
4287 /* Otherwise, we need to create a new temporary for the gimplified
4290 /* We can't return an lvalue if we have an internal postqueue. The
4291 object the lvalue refers to would (probably) be modified by the
4292 postqueue; we need to copy the value out first, which means an
4294 if ((fallback & fb_lvalue) && !internal_post
4295 && is_gimple_addressable (*expr_p))
4297 /* An lvalue will do. Take the address of the expression, store it
4298 in a temporary, and replace the expression with an INDIRECT_REF of
4300 tmp = build_fold_addr_expr (*expr_p);
4301 gimplify_expr (&tmp, pre_p, post_p, is_gimple_reg, fb_rvalue);
4302 *expr_p = build1 (INDIRECT_REF, TREE_TYPE (TREE_TYPE (tmp)), tmp);
4304 else if ((fallback & fb_rvalue) && is_gimple_formal_tmp_rhs (*expr_p))
4306 gcc_assert (!VOID_TYPE_P (TREE_TYPE (*expr_p)));
4308 /* An rvalue will do. Assign the gimplified expression into a new
4309 temporary TMP and replace the original expression with TMP. */
4311 if (internal_post || (fallback & fb_lvalue))
4312 /* The postqueue might change the value of the expression between
4313 the initialization and use of the temporary, so we can't use a
4314 formal temp. FIXME do we care? */
4315 *expr_p = get_initialized_tmp_var (*expr_p, pre_p, post_p);
4317 *expr_p = get_formal_tmp_var (*expr_p, pre_p);
4319 if (TREE_CODE (*expr_p) != SSA_NAME)
4320 DECL_GIMPLE_FORMAL_TEMP_P (*expr_p) = 1;
4324 #ifdef ENABLE_CHECKING
4325 if (!(fallback & fb_mayfail))
4327 fprintf (stderr, "gimplification failed:\n");
4328 print_generic_expr (stderr, *expr_p, 0);
4329 debug_tree (*expr_p);
4330 internal_error ("gimplification failed");
4333 gcc_assert (fallback & fb_mayfail);
4334 /* If this is an asm statement, and the user asked for the
4335 impossible, don't abort. Fail and let gimplify_asm_expr
4341 /* Make sure the temporary matches our predicate. */
4342 gcc_assert ((*gimple_test_f) (*expr_p));
4346 annotate_all_with_locus (&internal_post, input_location);
4347 append_to_statement_list (internal_post, pre_p);
4351 input_location = saved_location;
4355 /* Look through TYPE for variable-sized objects and gimplify each such
4356 size that we find. Add to LIST_P any statements generated. */
4359 gimplify_type_sizes (tree type, tree *list_p)
4363 /* Note that we do not check for TYPE_SIZES_GIMPLIFIED already set because
4364 that's not supposed to happen on types where gimplification does anything.
4365 We should assert that it isn't set, but we can indeed be called multiple
4366 times on pointers. Unfortunately, this includes fat pointers which we
4367 can't easily test for. We could pass TYPE down to gimplify_one_sizepos
4368 and test there, but it doesn't seem worth it. */
4370 /* We first do the main variant, then copy into any other variants. */
4371 type = TYPE_MAIN_VARIANT (type);
4373 switch (TREE_CODE (type))
4383 gimplify_one_sizepos (&TYPE_MIN_VALUE (type), list_p);
4384 gimplify_one_sizepos (&TYPE_MAX_VALUE (type), list_p);
4386 for (t = TYPE_NEXT_VARIANT (type); t; t = TYPE_NEXT_VARIANT (t))
4388 TYPE_MIN_VALUE (t) = TYPE_MIN_VALUE (type);
4389 TYPE_MAX_VALUE (t) = TYPE_MAX_VALUE (type);
4390 TYPE_SIZES_GIMPLIFIED (t) = 1;
4395 /* These types may not have declarations, so handle them here. */
4396 if (!TYPE_SIZES_GIMPLIFIED (TREE_TYPE (type)))
4397 gimplify_type_sizes (TREE_TYPE (type), list_p);
4399 if (!TYPE_SIZES_GIMPLIFIED (TYPE_DOMAIN (type)))
4400 gimplify_type_sizes (TYPE_DOMAIN (type), list_p);
4405 case QUAL_UNION_TYPE:
4406 for (field = TYPE_FIELDS (type); field; field = TREE_CHAIN (field))
4407 if (TREE_CODE (field) == FIELD_DECL)
4408 gimplify_one_sizepos (&DECL_FIELD_OFFSET (field), list_p);
4415 gimplify_one_sizepos (&TYPE_SIZE (type), list_p);
4416 gimplify_one_sizepos (&TYPE_SIZE_UNIT (type), list_p);
4418 for (t = TYPE_NEXT_VARIANT (type); t; t = TYPE_NEXT_VARIANT (t))
4420 TYPE_SIZE (t) = TYPE_SIZE (type);
4421 TYPE_SIZE_UNIT (t) = TYPE_SIZE_UNIT (type);
4422 TYPE_SIZES_GIMPLIFIED (t) = 1;
4425 TYPE_SIZES_GIMPLIFIED (type) = 1;
4428 /* A subroutine of gimplify_type_sizes to make sure that *EXPR_P,
4429 a size or position, has had all of its SAVE_EXPRs evaluated.
4430 We add any required statements to STMT_P. */
4433 gimplify_one_sizepos (tree *expr_p, tree *stmt_p)
4435 /* We don't do anything if the value isn't there, is constant, or contains
4436 A PLACEHOLDER_EXPR. We also don't want to do anything if it's already
4437 a VAR_DECL. If it's a VAR_DECL from another function, the gimplfier
4438 will want to replace it with a new variable, but that will cause problems
4439 if this type is from outside the function. It's OK to have that here. */
4440 if (*expr_p == NULL_TREE || TREE_CONSTANT (*expr_p)
4441 || TREE_CODE (*expr_p) == VAR_DECL
4442 || CONTAINS_PLACEHOLDER_P (*expr_p))
4445 *expr_p = unshare_expr (*expr_p);
4446 gimplify_expr (expr_p, stmt_p, NULL, is_gimple_val, fb_rvalue);
4449 #ifdef ENABLE_CHECKING
4450 /* Compare types A and B for a "close enough" match. */
4453 cpt_same_type (tree a, tree b)
4455 if (lang_hooks.types_compatible_p (a, b))
4458 /* ??? The C++ FE decomposes METHOD_TYPES to FUNCTION_TYPES and doesn't
4459 link them together. This routine is intended to catch type errors
4460 that will affect the optimizers, and the optimizers don't add new
4461 dereferences of function pointers, so ignore it. */
4462 if ((TREE_CODE (a) == FUNCTION_TYPE || TREE_CODE (a) == METHOD_TYPE)
4463 && (TREE_CODE (b) == FUNCTION_TYPE || TREE_CODE (b) == METHOD_TYPE))
4466 /* ??? The C FE pushes type qualifiers after the fact into the type of
4467 the element from the type of the array. See build_unary_op's handling
4468 of ADDR_EXPR. This seems wrong -- if we were going to do this, we
4469 should have done it when creating the variable in the first place.
4470 Alternately, why aren't the two array types made variants? */
4471 if (TREE_CODE (a) == ARRAY_TYPE && TREE_CODE (b) == ARRAY_TYPE)
4472 return cpt_same_type (TREE_TYPE (a), TREE_TYPE (b));
4474 /* And because of those, we have to recurse down through pointers. */
4475 if (POINTER_TYPE_P (a) && POINTER_TYPE_P (b))
4476 return cpt_same_type (TREE_TYPE (a), TREE_TYPE (b));
4481 /* Check for some cases of the front end missing cast expressions.
4482 The type of a dereference should correspond to the pointer type;
4483 similarly the type of an address should match its object. */
4486 check_pointer_types_r (tree *tp, int *walk_subtrees ATTRIBUTE_UNUSED,
4487 void *data ATTRIBUTE_UNUSED)
4490 tree ptype, otype, dtype;
4492 switch (TREE_CODE (t))
4496 otype = TREE_TYPE (t);
4497 ptype = TREE_TYPE (TREE_OPERAND (t, 0));
4498 dtype = TREE_TYPE (ptype);
4499 gcc_assert (cpt_same_type (otype, dtype));
4503 ptype = TREE_TYPE (t);
4504 otype = TREE_TYPE (TREE_OPERAND (t, 0));
4505 dtype = TREE_TYPE (ptype);
4506 if (!cpt_same_type (otype, dtype))
4508 /* &array is allowed to produce a pointer to the element, rather than
4509 a pointer to the array type. We must allow this in order to
4510 properly represent assigning the address of an array in C into
4511 pointer to the element type. */
4512 gcc_assert (TREE_CODE (otype) == ARRAY_TYPE
4513 && POINTER_TYPE_P (ptype)
4514 && cpt_same_type (TREE_TYPE (otype), dtype));
4528 /* Gimplify the body of statements pointed by BODY_P. FNDECL is the
4529 function decl containing BODY. */
4532 gimplify_body (tree *body_p, tree fndecl, bool do_parms)
4534 location_t saved_location = input_location;
4535 tree body, parm_stmts;
4537 timevar_push (TV_TREE_GIMPLIFY);
4538 push_gimplify_context ();
4540 /* Unshare most shared trees in the body and in that of any nested functions.
4541 It would seem we don't have to do this for nested functions because
4542 they are supposed to be output and then the outer function gimplified
4543 first, but the g++ front end doesn't always do it that way. */
4544 unshare_body (body_p, fndecl);
4545 unvisit_body (body_p, fndecl);
4547 /* Make sure input_location isn't set to something wierd. */
4548 input_location = DECL_SOURCE_LOCATION (fndecl);
4550 /* Resolve callee-copies. This has to be done before processing
4551 the body so that DECL_VALUE_EXPR gets processed correctly. */
4552 parm_stmts = do_parms ? gimplify_parameters () : NULL;
4554 /* Gimplify the function's body. */
4555 gimplify_stmt (body_p);
4559 body = alloc_stmt_list ();
4560 else if (TREE_CODE (body) == STATEMENT_LIST)
4562 tree t = expr_only (*body_p);
4567 /* If there isn't an outer BIND_EXPR, add one. */
4568 if (TREE_CODE (body) != BIND_EXPR)
4570 tree b = build (BIND_EXPR, void_type_node, NULL_TREE,
4571 NULL_TREE, NULL_TREE);
4572 TREE_SIDE_EFFECTS (b) = 1;
4573 append_to_statement_list_force (body, &BIND_EXPR_BODY (b));
4577 /* If we had callee-copies statements, insert them at the beginning
4581 append_to_statement_list_force (BIND_EXPR_BODY (body), &parm_stmts);
4582 BIND_EXPR_BODY (body) = parm_stmts;
4585 /* Unshare again, in case gimplification was sloppy. */
4586 unshare_all_trees (body);
4590 pop_gimplify_context (body);
4592 #ifdef ENABLE_CHECKING
4593 walk_tree (body_p, check_pointer_types_r, NULL, NULL);
4596 timevar_pop (TV_TREE_GIMPLIFY);
4597 input_location = saved_location;
4600 /* Entry point to the gimplification pass. FNDECL is the FUNCTION_DECL
4601 node for the function we want to gimplify. */
4604 gimplify_function_tree (tree fndecl)
4608 oldfn = current_function_decl;
4609 current_function_decl = fndecl;
4610 cfun = DECL_STRUCT_FUNCTION (fndecl);
4612 allocate_struct_function (fndecl);
4614 gimplify_body (&DECL_SAVED_TREE (fndecl), fndecl, true);
4616 /* If we're instrumenting function entry/exit, then prepend the call to
4617 the entry hook and wrap the whole function in a TRY_FINALLY_EXPR to
4618 catch the exit hook. */
4619 /* ??? Add some way to ignore exceptions for this TFE. */
4620 if (flag_instrument_function_entry_exit
4621 && ! DECL_NO_INSTRUMENT_FUNCTION_ENTRY_EXIT (fndecl))
4625 tf = build (TRY_FINALLY_EXPR, void_type_node, NULL, NULL);
4626 TREE_SIDE_EFFECTS (tf) = 1;
4627 x = DECL_SAVED_TREE (fndecl);
4628 append_to_statement_list (x, &TREE_OPERAND (tf, 0));
4629 x = implicit_built_in_decls[BUILT_IN_PROFILE_FUNC_EXIT];
4630 x = build_function_call_expr (x, NULL);
4631 append_to_statement_list (x, &TREE_OPERAND (tf, 1));
4633 bind = build (BIND_EXPR, void_type_node, NULL, NULL, NULL);
4634 TREE_SIDE_EFFECTS (bind) = 1;
4635 x = implicit_built_in_decls[BUILT_IN_PROFILE_FUNC_ENTER];
4636 x = build_function_call_expr (x, NULL);
4637 append_to_statement_list (x, &BIND_EXPR_BODY (bind));
4638 append_to_statement_list (tf, &BIND_EXPR_BODY (bind));
4640 DECL_SAVED_TREE (fndecl) = bind;
4643 current_function_decl = oldfn;
4644 cfun = oldfn ? DECL_STRUCT_FUNCTION (oldfn) : NULL;
4648 /* Expands EXPR to list of gimple statements STMTS. If SIMPLE is true,
4649 force the result to be either ssa_name or an invariant, otherwise
4650 just force it to be a rhs expression. If VAR is not NULL, make the
4651 base variable of the final destination be VAR if suitable. */
4654 force_gimple_operand (tree expr, tree *stmts, bool simple, tree var)
4657 enum gimplify_status ret;
4658 gimple_predicate gimple_test_f;
4662 if (is_gimple_val (expr))
4665 gimple_test_f = simple ? is_gimple_val : is_gimple_reg_rhs;
4667 push_gimplify_context ();
4668 gimplify_ctxp->into_ssa = true;
4671 expr = build (MODIFY_EXPR, TREE_TYPE (var), var, expr);
4673 ret = gimplify_expr (&expr, stmts, NULL,
4674 gimple_test_f, fb_rvalue);
4675 gcc_assert (ret != GS_ERROR);
4677 for (t = gimplify_ctxp->temps; t ; t = TREE_CHAIN (t))
4678 add_referenced_tmp_var (t);
4680 pop_gimplify_context (NULL);
4685 #include "gt-gimplify.h"