1 /* Tree lowering pass. This pass converts the GENERIC functions-as-trees
2 tree representation into the GIMPLE form.
3 Copyright (C) 2002, 2003, 2004 Free Software Foundation, Inc.
4 Major work done by Sebastian Pop <s.pop@laposte.net>,
5 Diego Novillo <dnovillo@redhat.com> and Jason Merrill <jason@redhat.com>.
7 This file is part of GCC.
9 GCC is free software; you can redistribute it and/or modify it under
10 the terms of the GNU General Public License as published by the Free
11 Software Foundation; either version 2, or (at your option) any later
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}. */
220 append_to_statement_list_1 (tree t, tree *list_p, bool side_effects)
223 tree_stmt_iterator i;
230 if (t && TREE_CODE (t) == STATEMENT_LIST)
235 *list_p = list = alloc_stmt_list ();
239 tsi_link_after (&i, t, TSI_CONTINUE_LINKING);
242 /* Add T to the end of the list container pointed by LIST_P.
243 If T is an expression with no effects, it is ignored. */
246 append_to_statement_list (tree t, tree *list_p)
248 append_to_statement_list_1 (t, list_p, t ? TREE_SIDE_EFFECTS (t) : false);
251 /* Similar, but the statement is always added, regardless of side effects. */
254 append_to_statement_list_force (tree t, tree *list_p)
256 append_to_statement_list_1 (t, list_p, t != NULL);
259 /* Both gimplify the statement T and append it to LIST_P. */
262 gimplify_and_add (tree t, tree *list_p)
265 append_to_statement_list (t, list_p);
268 /* Strip off a legitimate source ending from the input string NAME of
269 length LEN. Rather than having to know the names used by all of
270 our front ends, we strip off an ending of a period followed by
271 up to five characters. (Java uses ".class".) */
274 remove_suffix (char *name, int len)
278 for (i = 2; i < 8 && len > i; i++)
280 if (name[len - i] == '.')
282 name[len - i] = '\0';
288 /* Create a nameless artificial label and put it in the current function
289 context. Returns the newly created label. */
292 create_artificial_label (void)
294 tree lab = build_decl (LABEL_DECL, NULL_TREE, void_type_node);
296 DECL_ARTIFICIAL (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 gimplify_type_sizes (TREE_TYPE (decl), stmt_p);
1001 gimplify_one_sizepos (&DECL_SIZE (decl), stmt_p);
1002 gimplify_one_sizepos (&DECL_SIZE_UNIT (decl), stmt_p);
1004 /* All occurrences of this decl in final gimplified code will be
1005 replaced by indirection. Setting DECL_VALUE_EXPR does two
1006 things: First, it lets the rest of the gimplifier know what
1007 replacement to use. Second, it lets the debug info know
1008 where to find the value. */
1009 ptr_type = build_pointer_type (TREE_TYPE (decl));
1010 addr = create_tmp_var (ptr_type, get_name (decl));
1011 DECL_IGNORED_P (addr) = 0;
1012 t = build_fold_indirect_ref (addr);
1013 DECL_VALUE_EXPR (decl) = t;
1015 args = tree_cons (NULL, DECL_SIZE_UNIT (decl), NULL);
1016 t = built_in_decls[BUILT_IN_ALLOCA];
1017 t = build_function_call_expr (t, args);
1018 t = fold_convert (ptr_type, t);
1019 t = build2 (MODIFY_EXPR, void_type_node, addr, t);
1021 gimplify_and_add (t, stmt_p);
1023 /* Indicate that we need to restore the stack level when the
1024 enclosing BIND_EXPR is exited. */
1025 gimplify_ctxp->save_stack = true;
1028 if (init && init != error_mark_node)
1030 if (!TREE_STATIC (decl))
1032 DECL_INITIAL (decl) = NULL_TREE;
1033 init = build (MODIFY_EXPR, void_type_node, decl, init);
1034 gimplify_and_add (init, stmt_p);
1037 /* We must still examine initializers for static variables
1038 as they may contain a label address. */
1039 walk_tree (&init, force_labels_r, NULL, NULL);
1042 /* This decl isn't mentioned in the enclosing block, so add it to the
1043 list of temps. FIXME it seems a bit of a kludge to say that
1044 anonymous artificial vars aren't pushed, but everything else is. */
1045 if (DECL_ARTIFICIAL (decl) && DECL_NAME (decl) == NULL_TREE)
1046 gimple_add_tmp_var (decl);
1052 /* Gimplify a LOOP_EXPR. Normally this just involves gimplifying the body
1053 and replacing the LOOP_EXPR with goto, but if the loop contains an
1054 EXIT_EXPR, we need to append a label for it to jump to. */
1056 static enum gimplify_status
1057 gimplify_loop_expr (tree *expr_p, tree *pre_p)
1059 tree saved_label = gimplify_ctxp->exit_label;
1060 tree start_label = build1 (LABEL_EXPR, void_type_node, NULL_TREE);
1061 tree jump_stmt = build_and_jump (&LABEL_EXPR_LABEL (start_label));
1063 append_to_statement_list (start_label, pre_p);
1065 gimplify_ctxp->exit_label = NULL_TREE;
1067 gimplify_and_add (LOOP_EXPR_BODY (*expr_p), pre_p);
1069 if (gimplify_ctxp->exit_label)
1071 append_to_statement_list (jump_stmt, pre_p);
1072 *expr_p = build1 (LABEL_EXPR, void_type_node, gimplify_ctxp->exit_label);
1075 *expr_p = jump_stmt;
1077 gimplify_ctxp->exit_label = saved_label;
1082 /* Compare two case labels. Because the front end should already have
1083 made sure that case ranges do not overlap, it is enough to only compare
1084 the CASE_LOW values of each case label. */
1087 compare_case_labels (const void *p1, const void *p2)
1089 tree case1 = *(tree *)p1;
1090 tree case2 = *(tree *)p2;
1092 return tree_int_cst_compare (CASE_LOW (case1), CASE_LOW (case2));
1095 /* Sort the case labels in LABEL_VEC in place in ascending order. */
1098 sort_case_labels (tree label_vec)
1100 size_t len = TREE_VEC_LENGTH (label_vec);
1101 tree default_case = TREE_VEC_ELT (label_vec, len - 1);
1103 if (CASE_LOW (default_case))
1107 /* The last label in the vector should be the default case
1109 for (i = 0; i < len; ++i)
1111 tree t = TREE_VEC_ELT (label_vec, i);
1115 TREE_VEC_ELT (label_vec, i) = TREE_VEC_ELT (label_vec, len - 1);
1116 TREE_VEC_ELT (label_vec, len - 1) = default_case;
1122 qsort (&TREE_VEC_ELT (label_vec, 0), len - 1, sizeof (tree),
1123 compare_case_labels);
1126 /* Gimplify a SWITCH_EXPR, and collect a TREE_VEC of the labels it can
1129 static enum gimplify_status
1130 gimplify_switch_expr (tree *expr_p, tree *pre_p)
1132 tree switch_expr = *expr_p;
1133 enum gimplify_status ret;
1135 ret = gimplify_expr (&SWITCH_COND (switch_expr), pre_p, NULL,
1136 is_gimple_val, fb_rvalue);
1138 if (SWITCH_BODY (switch_expr))
1140 varray_type labels, saved_labels;
1141 tree label_vec, default_case = NULL_TREE;
1144 /* If someone can be bothered to fill in the labels, they can
1145 be bothered to null out the body too. */
1146 gcc_assert (!SWITCH_LABELS (switch_expr));
1148 saved_labels = gimplify_ctxp->case_labels;
1149 VARRAY_TREE_INIT (gimplify_ctxp->case_labels, 8, "case_labels");
1151 gimplify_to_stmt_list (&SWITCH_BODY (switch_expr));
1153 labels = gimplify_ctxp->case_labels;
1154 gimplify_ctxp->case_labels = saved_labels;
1156 len = VARRAY_ACTIVE_SIZE (labels);
1158 for (i = 0; i < len; ++i)
1160 tree t = VARRAY_TREE (labels, i);
1163 /* The default case must be the last label in the list. */
1165 VARRAY_TREE (labels, i) = VARRAY_TREE (labels, len - 1);
1171 label_vec = make_tree_vec (len + 1);
1172 SWITCH_LABELS (*expr_p) = label_vec;
1173 append_to_statement_list (switch_expr, pre_p);
1177 /* If the switch has no default label, add one, so that we jump
1178 around the switch body. */
1179 default_case = build (CASE_LABEL_EXPR, void_type_node, NULL_TREE,
1180 NULL_TREE, create_artificial_label ());
1181 append_to_statement_list (SWITCH_BODY (switch_expr), pre_p);
1182 *expr_p = build (LABEL_EXPR, void_type_node,
1183 CASE_LABEL (default_case));
1186 *expr_p = SWITCH_BODY (switch_expr);
1188 for (i = 0; i < len; ++i)
1189 TREE_VEC_ELT (label_vec, i) = VARRAY_TREE (labels, i);
1190 TREE_VEC_ELT (label_vec, len) = default_case;
1192 sort_case_labels (label_vec);
1194 SWITCH_BODY (switch_expr) = NULL;
1197 gcc_assert (SWITCH_LABELS (switch_expr));
1202 static enum gimplify_status
1203 gimplify_case_label_expr (tree *expr_p)
1205 tree expr = *expr_p;
1207 gcc_assert (gimplify_ctxp->case_labels);
1208 VARRAY_PUSH_TREE (gimplify_ctxp->case_labels, expr);
1209 *expr_p = build (LABEL_EXPR, void_type_node, CASE_LABEL (expr));
1213 /* Build a GOTO to the LABEL_DECL pointed to by LABEL_P, building it first
1217 build_and_jump (tree *label_p)
1219 if (label_p == NULL)
1220 /* If there's nowhere to jump, just fall through. */
1223 if (*label_p == NULL_TREE)
1225 tree label = create_artificial_label ();
1229 return build1 (GOTO_EXPR, void_type_node, *label_p);
1232 /* Gimplify an EXIT_EXPR by converting to a GOTO_EXPR inside a COND_EXPR.
1233 This also involves building a label to jump to and communicating it to
1234 gimplify_loop_expr through gimplify_ctxp->exit_label. */
1236 static enum gimplify_status
1237 gimplify_exit_expr (tree *expr_p)
1239 tree cond = TREE_OPERAND (*expr_p, 0);
1242 expr = build_and_jump (&gimplify_ctxp->exit_label);
1243 expr = build (COND_EXPR, void_type_node, cond, expr, NULL_TREE);
1249 /* A helper function to be called via walk_tree. Mark all labels under *TP
1250 as being forced. To be called for DECL_INITIAL of static variables. */
1253 force_labels_r (tree *tp, int *walk_subtrees, void *data ATTRIBUTE_UNUSED)
1257 if (TREE_CODE (*tp) == LABEL_DECL)
1258 FORCED_LABEL (*tp) = 1;
1263 /* *EXPR_P is a COMPONENT_REF being used as an rvalue. If its type is
1264 different from its canonical type, wrap the whole thing inside a
1265 NOP_EXPR and force the type of the COMPONENT_REF to be the canonical
1268 The canonical type of a COMPONENT_REF is the type of the field being
1269 referenced--unless the field is a bit-field which can be read directly
1270 in a smaller mode, in which case the canonical type is the
1271 sign-appropriate type corresponding to that mode. */
1274 canonicalize_component_ref (tree *expr_p)
1276 tree expr = *expr_p;
1279 gcc_assert (TREE_CODE (expr) == COMPONENT_REF);
1281 if (INTEGRAL_TYPE_P (TREE_TYPE (expr)))
1282 type = TREE_TYPE (get_unwidened (expr, NULL_TREE));
1284 type = TREE_TYPE (TREE_OPERAND (expr, 1));
1286 if (TREE_TYPE (expr) != type)
1288 tree old_type = TREE_TYPE (expr);
1290 /* Set the type of the COMPONENT_REF to the underlying type. */
1291 TREE_TYPE (expr) = type;
1293 /* And wrap the whole thing inside a NOP_EXPR. */
1294 expr = build1 (NOP_EXPR, old_type, expr);
1300 /* If a NOP conversion is changing a pointer to array of foo to a pointer
1301 to foo, embed that change in the ADDR_EXPR by converting
1306 where L is the lower bound. For simplicity, only do this for constant
1310 canonicalize_addr_expr (tree *expr_p)
1312 tree expr = *expr_p;
1313 tree ctype = TREE_TYPE (expr);
1314 tree addr_expr = TREE_OPERAND (expr, 0);
1315 tree atype = TREE_TYPE (addr_expr);
1316 tree dctype, datype, ddatype, otype, obj_expr;
1318 /* Both cast and addr_expr types should be pointers. */
1319 if (!POINTER_TYPE_P (ctype) || !POINTER_TYPE_P (atype))
1322 /* The addr_expr type should be a pointer to an array. */
1323 datype = TREE_TYPE (atype);
1324 if (TREE_CODE (datype) != ARRAY_TYPE)
1327 /* Both cast and addr_expr types should address the same object type. */
1328 dctype = TREE_TYPE (ctype);
1329 ddatype = TREE_TYPE (datype);
1330 if (!lang_hooks.types_compatible_p (ddatype, dctype))
1333 /* The addr_expr and the object type should match. */
1334 obj_expr = TREE_OPERAND (addr_expr, 0);
1335 otype = TREE_TYPE (obj_expr);
1336 if (!lang_hooks.types_compatible_p (otype, datype))
1339 /* The lower bound and element sizes must be constant. */
1340 if (TREE_CODE (TYPE_SIZE_UNIT (dctype)) != INTEGER_CST
1341 || !TYPE_DOMAIN (datype) || !TYPE_MIN_VALUE (TYPE_DOMAIN (datype))
1342 || TREE_CODE (TYPE_MIN_VALUE (TYPE_DOMAIN (datype))) != INTEGER_CST)
1345 /* All checks succeeded. Build a new node to merge the cast. */
1346 *expr_p = build4 (ARRAY_REF, dctype, obj_expr,
1347 TYPE_MIN_VALUE (TYPE_DOMAIN (datype)),
1348 TYPE_MIN_VALUE (TYPE_DOMAIN (datype)),
1349 size_binop (EXACT_DIV_EXPR, TYPE_SIZE_UNIT (dctype),
1350 size_int (TYPE_ALIGN_UNIT (dctype))));
1351 *expr_p = build1 (ADDR_EXPR, ctype, *expr_p);
1354 /* *EXPR_P is a NOP_EXPR or CONVERT_EXPR. Remove it and/or other conversions
1355 underneath as appropriate. */
1357 static enum gimplify_status
1358 gimplify_conversion (tree *expr_p)
1360 /* If we still have a conversion at the toplevel, then strip
1361 away all but the outermost conversion. */
1362 if (TREE_CODE (*expr_p) == NOP_EXPR || TREE_CODE (*expr_p) == CONVERT_EXPR)
1364 STRIP_SIGN_NOPS (TREE_OPERAND (*expr_p, 0));
1366 /* And remove the outermost conversion if it's useless. */
1367 if (tree_ssa_useless_type_conversion (*expr_p))
1368 *expr_p = TREE_OPERAND (*expr_p, 0);
1371 /* If we still have a conversion at the toplevel,
1372 then canonicalize some constructs. */
1373 if (TREE_CODE (*expr_p) == NOP_EXPR || TREE_CODE (*expr_p) == CONVERT_EXPR)
1375 tree sub = TREE_OPERAND (*expr_p, 0);
1377 /* If a NOP conversion is changing the type of a COMPONENT_REF
1378 expression, then canonicalize its type now in order to expose more
1379 redundant conversions. */
1380 if (TREE_CODE (sub) == COMPONENT_REF)
1381 canonicalize_component_ref (&TREE_OPERAND (*expr_p, 0));
1383 /* If a NOP conversion is changing a pointer to array of foo
1384 to a pointer to foo, embed that change in the ADDR_EXPR. */
1385 else if (TREE_CODE (sub) == ADDR_EXPR)
1386 canonicalize_addr_expr (expr_p);
1392 /* Gimplify the COMPONENT_REF, ARRAY_REF, REALPART_EXPR or IMAGPART_EXPR
1393 node pointed by EXPR_P.
1396 : min_lval '[' val ']'
1398 | compound_lval '[' val ']'
1399 | compound_lval '.' ID
1401 This is not part of the original SIMPLE definition, which separates
1402 array and member references, but it seems reasonable to handle them
1403 together. Also, this way we don't run into problems with union
1404 aliasing; gcc requires that for accesses through a union to alias, the
1405 union reference must be explicit, which was not always the case when we
1406 were splitting up array and member refs.
1408 PRE_P points to the list where side effects that must happen before
1409 *EXPR_P should be stored.
1411 POST_P points to the list where side effects that must happen after
1412 *EXPR_P should be stored. */
1414 static enum gimplify_status
1415 gimplify_compound_lval (tree *expr_p, tree *pre_p,
1416 tree *post_p, fallback_t fallback)
1420 enum gimplify_status ret = GS_OK, tret;
1423 /* Create a stack of the subexpressions so later we can walk them in
1424 order from inner to outer.
1426 This array is very memory consuming. Don't even think of making
1428 VARRAY_GENERIC_PTR_NOGC_INIT (stack, 10, "stack");
1430 /* We can either handle REALPART_EXPR, IMAGEPART_EXPR anything that
1431 handled_components can deal with. */
1433 (handled_component_p (*p)
1434 || TREE_CODE (*p) == REALPART_EXPR || TREE_CODE (*p) == IMAGPART_EXPR);
1435 p = &TREE_OPERAND (*p, 0))
1436 VARRAY_PUSH_GENERIC_PTR_NOGC (stack, *p);
1438 gcc_assert (VARRAY_ACTIVE_SIZE (stack));
1440 /* Now STACK is a stack of pointers to all the refs we've walked through
1441 and P points to the innermost expression.
1443 Java requires that we elaborated nodes in source order. That
1444 means we must gimplify the inner expression followed by each of
1445 the indices, in order. But we can't gimplify the inner
1446 expression until we deal with any variable bounds, sizes, or
1447 positions in order to deal with PLACEHOLDER_EXPRs.
1449 So we do this in three steps. First we deal with the annotations
1450 for any variables in the components, then we gimplify the base,
1451 then we gimplify any indices, from left to right. */
1452 for (i = VARRAY_ACTIVE_SIZE (stack) - 1; i >= 0; i--)
1454 tree t = VARRAY_GENERIC_PTR_NOGC (stack, i);
1456 if (TREE_CODE (t) == ARRAY_REF || TREE_CODE (t) == ARRAY_RANGE_REF)
1458 /* Gimplify the low bound and element type size and put them into
1459 the ARRAY_REF. If these values are set, they have already been
1461 if (!TREE_OPERAND (t, 2))
1463 tree low = unshare_expr (array_ref_low_bound (t));
1464 if (!is_gimple_min_invariant (low))
1466 TREE_OPERAND (t, 2) = low;
1467 tret = gimplify_expr (&TREE_OPERAND (t, 2), pre_p, post_p,
1468 is_gimple_formal_tmp_reg, fb_rvalue);
1469 ret = MIN (ret, tret);
1473 if (!TREE_OPERAND (t, 3))
1475 tree elmt_type = TREE_TYPE (TREE_TYPE (TREE_OPERAND (t, 0)));
1476 tree elmt_size = unshare_expr (array_ref_element_size (t));
1477 tree factor = size_int (TYPE_ALIGN_UNIT (elmt_type));
1479 /* Divide the element size by the alignment of the element
1481 elmt_size = size_binop (EXACT_DIV_EXPR, elmt_size, factor);
1483 if (!is_gimple_min_invariant (elmt_size))
1485 TREE_OPERAND (t, 3) = elmt_size;
1486 tret = gimplify_expr (&TREE_OPERAND (t, 3), pre_p, post_p,
1487 is_gimple_formal_tmp_reg, fb_rvalue);
1488 ret = MIN (ret, tret);
1492 else if (TREE_CODE (t) == COMPONENT_REF)
1494 /* Set the field offset into T and gimplify it. */
1495 if (!TREE_OPERAND (t, 2))
1497 tree offset = unshare_expr (component_ref_field_offset (t));
1498 tree field = TREE_OPERAND (t, 1);
1500 = size_int (DECL_OFFSET_ALIGN (field) / BITS_PER_UNIT);
1502 /* Divide the offset by its alignment. */
1503 offset = size_binop (EXACT_DIV_EXPR, offset, factor);
1505 if (!is_gimple_min_invariant (offset))
1507 TREE_OPERAND (t, 2) = offset;
1508 tret = gimplify_expr (&TREE_OPERAND (t, 2), pre_p, post_p,
1509 is_gimple_formal_tmp_reg, fb_rvalue);
1510 ret = MIN (ret, tret);
1516 /* Step 2 is to gimplify the base expression. */
1517 tret = gimplify_expr (p, pre_p, post_p, is_gimple_min_lval, fallback);
1518 ret = MIN (ret, tret);
1520 /* And finally, the indices and operands to BIT_FIELD_REF. During this
1521 loop we also remove any useless conversions. */
1522 for (; VARRAY_ACTIVE_SIZE (stack) > 0; )
1524 tree t = VARRAY_TOP_TREE (stack);
1526 if (TREE_CODE (t) == ARRAY_REF || TREE_CODE (t) == ARRAY_RANGE_REF)
1528 /* Gimplify the dimension.
1529 Temporary fix for gcc.c-torture/execute/20040313-1.c.
1530 Gimplify non-constant array indices into a temporary
1532 FIXME - The real fix is to gimplify post-modify
1533 expressions into a minimal gimple lvalue. However, that
1534 exposes bugs in alias analysis. The alias analyzer does
1535 not handle &PTR->FIELD very well. Will fix after the
1536 branch is merged into mainline (dnovillo 2004-05-03). */
1537 if (!is_gimple_min_invariant (TREE_OPERAND (t, 1)))
1539 tret = gimplify_expr (&TREE_OPERAND (t, 1), pre_p, post_p,
1540 is_gimple_formal_tmp_reg, fb_rvalue);
1541 ret = MIN (ret, tret);
1544 else if (TREE_CODE (t) == BIT_FIELD_REF)
1546 tret = gimplify_expr (&TREE_OPERAND (t, 1), pre_p, post_p,
1547 is_gimple_val, fb_rvalue);
1548 ret = MIN (ret, tret);
1549 tret = gimplify_expr (&TREE_OPERAND (t, 2), pre_p, post_p,
1550 is_gimple_val, fb_rvalue);
1551 ret = MIN (ret, tret);
1554 STRIP_USELESS_TYPE_CONVERSION (TREE_OPERAND (t, 0));
1556 /* The innermost expression P may have originally had TREE_SIDE_EFFECTS
1557 set which would have caused all the outer expressions in EXPR_P
1558 leading to P to also have had TREE_SIDE_EFFECTS set. */
1559 recalculate_side_effects (t);
1563 tret = gimplify_expr (p, pre_p, post_p, is_gimple_min_lval, fallback);
1564 ret = MIN (ret, tret);
1566 /* If the outermost expression is a COMPONENT_REF, canonicalize its type. */
1567 if ((fallback & fb_rvalue) && TREE_CODE (*expr_p) == COMPONENT_REF)
1569 canonicalize_component_ref (expr_p);
1570 ret = MIN (ret, GS_OK);
1573 VARRAY_FREE (stack);
1578 /* Gimplify the self modifying expression pointed by EXPR_P (++, --, +=, -=).
1580 PRE_P points to the list where side effects that must happen before
1581 *EXPR_P should be stored.
1583 POST_P points to the list where side effects that must happen after
1584 *EXPR_P should be stored.
1586 WANT_VALUE is nonzero iff we want to use the value of this expression
1587 in another expression. */
1589 static enum gimplify_status
1590 gimplify_self_mod_expr (tree *expr_p, tree *pre_p, tree *post_p,
1593 enum tree_code code;
1594 tree lhs, lvalue, rhs, t1;
1596 enum tree_code arith_code;
1597 enum gimplify_status ret;
1599 code = TREE_CODE (*expr_p);
1601 gcc_assert (code == POSTINCREMENT_EXPR || code == POSTDECREMENT_EXPR
1602 || code == PREINCREMENT_EXPR || code == PREDECREMENT_EXPR);
1604 /* Prefix or postfix? */
1605 if (code == POSTINCREMENT_EXPR || code == POSTDECREMENT_EXPR)
1606 /* Faster to treat as prefix if result is not used. */
1607 postfix = want_value;
1611 /* Add or subtract? */
1612 if (code == PREINCREMENT_EXPR || code == POSTINCREMENT_EXPR)
1613 arith_code = PLUS_EXPR;
1615 arith_code = MINUS_EXPR;
1617 /* Gimplify the LHS into a GIMPLE lvalue. */
1618 lvalue = TREE_OPERAND (*expr_p, 0);
1619 ret = gimplify_expr (&lvalue, pre_p, post_p, is_gimple_lvalue, fb_lvalue);
1620 if (ret == GS_ERROR)
1623 /* Extract the operands to the arithmetic operation. */
1625 rhs = TREE_OPERAND (*expr_p, 1);
1627 /* For postfix operator, we evaluate the LHS to an rvalue and then use
1628 that as the result value and in the postqueue operation. */
1631 ret = gimplify_expr (&lhs, pre_p, post_p, is_gimple_val, fb_rvalue);
1632 if (ret == GS_ERROR)
1636 t1 = build (arith_code, TREE_TYPE (*expr_p), lhs, rhs);
1637 t1 = build (MODIFY_EXPR, TREE_TYPE (lvalue), lvalue, t1);
1641 gimplify_and_add (t1, post_p);
1652 /* If *EXPR_P has a variable sized type, wrap it in a WITH_SIZE_EXPR. */
1655 maybe_with_size_expr (tree *expr_p)
1657 tree expr = *expr_p;
1658 tree type = TREE_TYPE (expr);
1661 /* If we've already wrapped this or the type is error_mark_node, we can't do
1663 if (TREE_CODE (expr) == WITH_SIZE_EXPR
1664 || type == error_mark_node)
1667 /* If the size isn't known or is a constant, we have nothing to do. */
1668 size = TYPE_SIZE_UNIT (type);
1669 if (!size || TREE_CODE (size) == INTEGER_CST)
1672 /* Otherwise, make a WITH_SIZE_EXPR. */
1673 size = unshare_expr (size);
1674 size = SUBSTITUTE_PLACEHOLDER_IN_EXPR (size, expr);
1675 *expr_p = build2 (WITH_SIZE_EXPR, type, expr, size);
1678 /* Subroutine of gimplify_call_expr: Gimplify a single argument. */
1680 static enum gimplify_status
1681 gimplify_arg (tree *expr_p, tree *pre_p)
1683 bool (*test) (tree);
1686 /* In general, we allow lvalues for function arguments to avoid
1687 extra overhead of copying large aggregates out of even larger
1688 aggregates into temporaries only to copy the temporaries to
1689 the argument list. Make optimizers happy by pulling out to
1690 temporaries those types that fit in registers. */
1691 if (is_gimple_reg_type (TREE_TYPE (*expr_p)))
1692 test = is_gimple_val, fb = fb_rvalue;
1694 test = is_gimple_lvalue, fb = fb_either;
1696 /* If this is a variable sized type, we must remember the size. */
1697 maybe_with_size_expr (expr_p);
1699 /* There is a sequence point before a function call. Side effects in
1700 the argument list must occur before the actual call. So, when
1701 gimplifying arguments, force gimplify_expr to use an internal
1702 post queue which is then appended to the end of PRE_P. */
1703 return gimplify_expr (expr_p, pre_p, NULL, test, fb);
1706 /* Gimplify the CALL_EXPR node pointed by EXPR_P. PRE_P points to the
1707 list where side effects that must happen before *EXPR_P should be stored.
1708 WANT_VALUE is true if the result of the call is desired. */
1710 static enum gimplify_status
1711 gimplify_call_expr (tree *expr_p, tree *pre_p, bool want_value)
1715 enum gimplify_status ret;
1717 gcc_assert (TREE_CODE (*expr_p) == CALL_EXPR);
1719 /* For reliable diagnostics during inlining, it is necessary that
1720 every call_expr be annotated with file and line. */
1721 if (! EXPR_HAS_LOCATION (*expr_p))
1722 SET_EXPR_LOCATION (*expr_p, input_location);
1724 /* This may be a call to a builtin function.
1726 Builtin function calls may be transformed into different
1727 (and more efficient) builtin function calls under certain
1728 circumstances. Unfortunately, gimplification can muck things
1729 up enough that the builtin expanders are not aware that certain
1730 transformations are still valid.
1732 So we attempt transformation/gimplification of the call before
1733 we gimplify the CALL_EXPR. At this time we do not manage to
1734 transform all calls in the same manner as the expanders do, but
1735 we do transform most of them. */
1736 decl = get_callee_fndecl (*expr_p);
1737 if (decl && DECL_BUILT_IN (decl))
1739 tree new = fold_builtin (*expr_p, !want_value);
1741 if (new && new != *expr_p)
1743 /* There was a transformation of this call which computes the
1744 same value, but in a more efficient way. Return and try
1750 if (DECL_FUNCTION_CODE (decl) == BUILT_IN_VA_START)
1751 /* Avoid gimplifying the second argument to va_start, which needs
1752 to be the plain PARM_DECL. */
1753 return gimplify_arg (&TREE_VALUE (TREE_OPERAND (*expr_p, 1)), pre_p);
1756 /* There is a sequence point before the call, so any side effects in
1757 the calling expression must occur before the actual call. Force
1758 gimplify_expr to use an internal post queue. */
1759 ret = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p, NULL,
1760 is_gimple_call_addr, fb_rvalue);
1762 if (PUSH_ARGS_REVERSED)
1763 TREE_OPERAND (*expr_p, 1) = nreverse (TREE_OPERAND (*expr_p, 1));
1764 for (arglist = TREE_OPERAND (*expr_p, 1); arglist;
1765 arglist = TREE_CHAIN (arglist))
1767 enum gimplify_status t;
1769 t = gimplify_arg (&TREE_VALUE (arglist), pre_p);
1774 if (PUSH_ARGS_REVERSED)
1775 TREE_OPERAND (*expr_p, 1) = nreverse (TREE_OPERAND (*expr_p, 1));
1777 /* Try this again in case gimplification exposed something. */
1778 if (ret != GS_ERROR && decl && DECL_BUILT_IN (decl))
1780 tree new = fold_builtin (*expr_p, !want_value);
1782 if (new && new != *expr_p)
1784 /* There was a transformation of this call which computes the
1785 same value, but in a more efficient way. Return and try
1792 /* If the function is "const" or "pure", then clear TREE_SIDE_EFFECTS on its
1793 decl. This allows us to eliminate redundant or useless
1794 calls to "const" functions. */
1795 if (TREE_CODE (*expr_p) == CALL_EXPR
1796 && (call_expr_flags (*expr_p) & (ECF_CONST | ECF_PURE)))
1797 TREE_SIDE_EFFECTS (*expr_p) = 0;
1802 /* Handle shortcut semantics in the predicate operand of a COND_EXPR by
1803 rewriting it into multiple COND_EXPRs, and possibly GOTO_EXPRs.
1805 TRUE_LABEL_P and FALSE_LABEL_P point to the labels to jump to if the
1806 condition is true or false, respectively. If null, we should generate
1807 our own to skip over the evaluation of this specific expression.
1809 This function is the tree equivalent of do_jump.
1811 shortcut_cond_r should only be called by shortcut_cond_expr. */
1814 shortcut_cond_r (tree pred, tree *true_label_p, tree *false_label_p)
1816 tree local_label = NULL_TREE;
1817 tree t, expr = NULL;
1819 /* OK, it's not a simple case; we need to pull apart the COND_EXPR to
1820 retain the shortcut semantics. Just insert the gotos here;
1821 shortcut_cond_expr will append the real blocks later. */
1822 if (TREE_CODE (pred) == TRUTH_ANDIF_EXPR)
1824 /* Turn if (a && b) into
1826 if (a); else goto no;
1827 if (b) goto yes; else goto no;
1830 if (false_label_p == NULL)
1831 false_label_p = &local_label;
1833 t = shortcut_cond_r (TREE_OPERAND (pred, 0), NULL, false_label_p);
1834 append_to_statement_list (t, &expr);
1836 t = shortcut_cond_r (TREE_OPERAND (pred, 1), true_label_p,
1838 append_to_statement_list (t, &expr);
1840 else if (TREE_CODE (pred) == TRUTH_ORIF_EXPR)
1842 /* Turn if (a || b) into
1845 if (b) goto yes; else goto no;
1848 if (true_label_p == NULL)
1849 true_label_p = &local_label;
1851 t = shortcut_cond_r (TREE_OPERAND (pred, 0), true_label_p, NULL);
1852 append_to_statement_list (t, &expr);
1854 t = shortcut_cond_r (TREE_OPERAND (pred, 1), true_label_p,
1856 append_to_statement_list (t, &expr);
1858 else if (TREE_CODE (pred) == COND_EXPR)
1860 /* As long as we're messing with gotos, turn if (a ? b : c) into
1862 if (b) goto yes; else goto no;
1864 if (c) goto yes; else goto no; */
1865 expr = build (COND_EXPR, void_type_node, TREE_OPERAND (pred, 0),
1866 shortcut_cond_r (TREE_OPERAND (pred, 1), true_label_p,
1868 shortcut_cond_r (TREE_OPERAND (pred, 2), true_label_p,
1873 expr = build (COND_EXPR, void_type_node, pred,
1874 build_and_jump (true_label_p),
1875 build_and_jump (false_label_p));
1880 t = build1 (LABEL_EXPR, void_type_node, local_label);
1881 append_to_statement_list (t, &expr);
1888 shortcut_cond_expr (tree expr)
1890 tree pred = TREE_OPERAND (expr, 0);
1891 tree then_ = TREE_OPERAND (expr, 1);
1892 tree else_ = TREE_OPERAND (expr, 2);
1893 tree true_label, false_label, end_label, t;
1895 tree *false_label_p;
1896 bool emit_end, emit_false;
1897 bool then_se = then_ && TREE_SIDE_EFFECTS (then_);
1898 bool else_se = else_ && TREE_SIDE_EFFECTS (else_);
1900 /* First do simple transformations. */
1903 /* If there is no 'else', turn (a && b) into if (a) if (b). */
1904 while (TREE_CODE (pred) == TRUTH_ANDIF_EXPR)
1906 TREE_OPERAND (expr, 0) = TREE_OPERAND (pred, 1);
1907 then_ = shortcut_cond_expr (expr);
1908 pred = TREE_OPERAND (pred, 0);
1909 expr = build (COND_EXPR, void_type_node, pred, then_, NULL_TREE);
1914 /* If there is no 'then', turn
1917 if (a); else if (b); else d. */
1918 while (TREE_CODE (pred) == TRUTH_ORIF_EXPR)
1920 TREE_OPERAND (expr, 0) = TREE_OPERAND (pred, 1);
1921 else_ = shortcut_cond_expr (expr);
1922 pred = TREE_OPERAND (pred, 0);
1923 expr = build (COND_EXPR, void_type_node, pred, NULL_TREE, else_);
1927 /* If we're done, great. */
1928 if (TREE_CODE (pred) != TRUTH_ANDIF_EXPR
1929 && TREE_CODE (pred) != TRUTH_ORIF_EXPR)
1932 /* Otherwise we need to mess with gotos. Change
1935 if (a); else goto no;
1938 and recursively gimplify the condition. */
1940 true_label = false_label = end_label = NULL_TREE;
1942 /* If our arms just jump somewhere, hijack those labels so we don't
1943 generate jumps to jumps. */
1946 && TREE_CODE (then_) == GOTO_EXPR
1947 && TREE_CODE (GOTO_DESTINATION (then_)) == LABEL_DECL)
1949 true_label = GOTO_DESTINATION (then_);
1955 && TREE_CODE (else_) == GOTO_EXPR
1956 && TREE_CODE (GOTO_DESTINATION (else_)) == LABEL_DECL)
1958 false_label = GOTO_DESTINATION (else_);
1963 /* If we aren't hijacking a label for the 'then' branch, it falls through. */
1965 true_label_p = &true_label;
1967 true_label_p = NULL;
1969 /* The 'else' branch also needs a label if it contains interesting code. */
1970 if (false_label || else_se)
1971 false_label_p = &false_label;
1973 false_label_p = NULL;
1975 /* If there was nothing else in our arms, just forward the label(s). */
1976 if (!then_se && !else_se)
1977 return shortcut_cond_r (pred, true_label_p, false_label_p);
1979 /* If our last subexpression already has a terminal label, reuse it. */
1981 expr = expr_last (else_);
1983 expr = expr_last (then_);
1986 if (expr && TREE_CODE (expr) == LABEL_EXPR)
1987 end_label = LABEL_EXPR_LABEL (expr);
1989 /* If we don't care about jumping to the 'else' branch, jump to the end
1990 if the condition is false. */
1992 false_label_p = &end_label;
1994 /* We only want to emit these labels if we aren't hijacking them. */
1995 emit_end = (end_label == NULL_TREE);
1996 emit_false = (false_label == NULL_TREE);
1998 pred = shortcut_cond_r (pred, true_label_p, false_label_p);
2001 append_to_statement_list (pred, &expr);
2003 append_to_statement_list (then_, &expr);
2006 t = build_and_jump (&end_label);
2007 append_to_statement_list (t, &expr);
2010 t = build1 (LABEL_EXPR, void_type_node, false_label);
2011 append_to_statement_list (t, &expr);
2013 append_to_statement_list (else_, &expr);
2015 if (emit_end && end_label)
2017 t = build1 (LABEL_EXPR, void_type_node, end_label);
2018 append_to_statement_list (t, &expr);
2024 /* EXPR is used in a boolean context; make sure it has BOOLEAN_TYPE. */
2027 gimple_boolify (tree expr)
2029 tree type = TREE_TYPE (expr);
2031 if (TREE_CODE (type) == BOOLEAN_TYPE)
2034 /* If this is the predicate of a COND_EXPR, it might not even be a
2036 expr = lang_hooks.truthvalue_conversion (expr);
2038 switch (TREE_CODE (expr))
2040 case TRUTH_AND_EXPR:
2042 case TRUTH_XOR_EXPR:
2043 case TRUTH_ANDIF_EXPR:
2044 case TRUTH_ORIF_EXPR:
2045 /* Also boolify the arguments of truth exprs. */
2046 TREE_OPERAND (expr, 1) = gimple_boolify (TREE_OPERAND (expr, 1));
2049 case TRUTH_NOT_EXPR:
2050 TREE_OPERAND (expr, 0) = gimple_boolify (TREE_OPERAND (expr, 0));
2053 case EQ_EXPR: case NE_EXPR:
2054 case LE_EXPR: case GE_EXPR: case LT_EXPR: case GT_EXPR:
2055 /* These expressions always produce boolean results. */
2056 TREE_TYPE (expr) = boolean_type_node;
2060 /* Other expressions that get here must have boolean values, but
2061 might need to be converted to the appropriate mode. */
2062 return convert (boolean_type_node, expr);
2066 /* Convert the conditional expression pointed by EXPR_P '(p) ? a : b;'
2075 The second form is used when *EXPR_P is of type void.
2077 TARGET is the tree for T1 above.
2079 PRE_P points to the list where side effects that must happen before
2080 *EXPR_P should be stored. */
2082 static enum gimplify_status
2083 gimplify_cond_expr (tree *expr_p, tree *pre_p, tree target)
2085 tree expr = *expr_p;
2086 tree tmp, tmp2, type;
2087 enum gimplify_status ret;
2089 type = TREE_TYPE (expr);
2091 TREE_TYPE (expr) = void_type_node;
2093 /* If this COND_EXPR has a value, copy the values into a temporary within
2095 else if (! VOID_TYPE_P (type))
2099 ret = gimplify_expr (&target, pre_p, NULL,
2100 is_gimple_min_lval, fb_lvalue);
2101 if (ret != GS_ERROR)
2104 tmp2 = unshare_expr (target);
2108 tmp2 = tmp = create_tmp_var (TREE_TYPE (expr), "iftmp");
2112 /* Build the then clause, 't1 = a;'. But don't build an assignment
2113 if this branch is void; in C++ it can be, if it's a throw. */
2114 if (TREE_TYPE (TREE_OPERAND (expr, 1)) != void_type_node)
2115 TREE_OPERAND (expr, 1)
2116 = build (MODIFY_EXPR, void_type_node, tmp, TREE_OPERAND (expr, 1));
2118 /* Build the else clause, 't1 = b;'. */
2119 if (TREE_TYPE (TREE_OPERAND (expr, 2)) != void_type_node)
2120 TREE_OPERAND (expr, 2)
2121 = build (MODIFY_EXPR, void_type_node, tmp2, TREE_OPERAND (expr, 2));
2123 TREE_TYPE (expr) = void_type_node;
2124 recalculate_side_effects (expr);
2126 /* Move the COND_EXPR to the prequeue. */
2127 gimplify_and_add (expr, pre_p);
2133 /* Make sure the condition has BOOLEAN_TYPE. */
2134 TREE_OPERAND (expr, 0) = gimple_boolify (TREE_OPERAND (expr, 0));
2136 /* Break apart && and || conditions. */
2137 if (TREE_CODE (TREE_OPERAND (expr, 0)) == TRUTH_ANDIF_EXPR
2138 || TREE_CODE (TREE_OPERAND (expr, 0)) == TRUTH_ORIF_EXPR)
2140 expr = shortcut_cond_expr (expr);
2142 if (expr != *expr_p)
2146 /* We can't rely on gimplify_expr to re-gimplify the expanded
2147 form properly, as cleanups might cause the target labels to be
2148 wrapped in a TRY_FINALLY_EXPR. To prevent that, we need to
2149 set up a conditional context. */
2150 gimple_push_condition ();
2151 gimplify_stmt (expr_p);
2152 gimple_pop_condition (pre_p);
2158 /* Now do the normal gimplification. */
2159 ret = gimplify_expr (&TREE_OPERAND (expr, 0), pre_p, NULL,
2160 is_gimple_condexpr, fb_rvalue);
2162 gimple_push_condition ();
2164 gimplify_to_stmt_list (&TREE_OPERAND (expr, 1));
2165 gimplify_to_stmt_list (&TREE_OPERAND (expr, 2));
2166 recalculate_side_effects (expr);
2168 gimple_pop_condition (pre_p);
2170 if (ret == GS_ERROR)
2172 else if (TREE_SIDE_EFFECTS (TREE_OPERAND (expr, 1)))
2174 else if (TREE_SIDE_EFFECTS (TREE_OPERAND (expr, 2)))
2175 /* Rewrite "if (a); else b" to "if (!a) b" */
2177 TREE_OPERAND (expr, 0) = invert_truthvalue (TREE_OPERAND (expr, 0));
2178 ret = gimplify_expr (&TREE_OPERAND (expr, 0), pre_p, NULL,
2179 is_gimple_condexpr, fb_rvalue);
2181 tmp = TREE_OPERAND (expr, 1);
2182 TREE_OPERAND (expr, 1) = TREE_OPERAND (expr, 2);
2183 TREE_OPERAND (expr, 2) = tmp;
2186 /* Both arms are empty; replace the COND_EXPR with its predicate. */
2187 expr = TREE_OPERAND (expr, 0);
2193 /* A subroutine of gimplify_modify_expr. Replace a MODIFY_EXPR with
2194 a call to __builtin_memcpy. */
2196 static enum gimplify_status
2197 gimplify_modify_expr_to_memcpy (tree *expr_p, tree size, bool want_value)
2199 tree args, t, to, to_ptr, from;
2201 to = TREE_OPERAND (*expr_p, 0);
2202 from = TREE_OPERAND (*expr_p, 1);
2204 args = tree_cons (NULL, size, NULL);
2206 t = build_fold_addr_expr (from);
2207 args = tree_cons (NULL, t, args);
2209 to_ptr = build_fold_addr_expr (to);
2210 args = tree_cons (NULL, to_ptr, args);
2211 t = implicit_built_in_decls[BUILT_IN_MEMCPY];
2212 t = build_function_call_expr (t, args);
2216 t = build1 (NOP_EXPR, TREE_TYPE (to_ptr), t);
2217 t = build1 (INDIRECT_REF, TREE_TYPE (to), t);
2224 /* A subroutine of gimplify_modify_expr. Replace a MODIFY_EXPR with
2225 a call to __builtin_memset. In this case we know that the RHS is
2226 a CONSTRUCTOR with an empty element list. */
2228 static enum gimplify_status
2229 gimplify_modify_expr_to_memset (tree *expr_p, tree size, bool want_value)
2231 tree args, t, to, to_ptr;
2233 to = TREE_OPERAND (*expr_p, 0);
2235 args = tree_cons (NULL, size, NULL);
2237 args = tree_cons (NULL, integer_zero_node, args);
2239 to_ptr = build_fold_addr_expr (to);
2240 args = tree_cons (NULL, to_ptr, args);
2241 t = implicit_built_in_decls[BUILT_IN_MEMSET];
2242 t = build_function_call_expr (t, args);
2246 t = build1 (NOP_EXPR, TREE_TYPE (to_ptr), t);
2247 t = build1 (INDIRECT_REF, TREE_TYPE (to), t);
2254 /* A subroutine of gimplify_init_ctor_preeval. Called via walk_tree,
2255 determine, cautiously, if a CONSTRUCTOR overlaps the lhs of an
2256 assignment. Returns non-null if we detect a potential overlap. */
2258 struct gimplify_init_ctor_preeval_data
2260 /* The base decl of the lhs object. May be NULL, in which case we
2261 have to assume the lhs is indirect. */
2264 /* The alias set of the lhs object. */
2269 gimplify_init_ctor_preeval_1 (tree *tp, int *walk_subtrees, void *xdata)
2271 struct gimplify_init_ctor_preeval_data *data
2272 = (struct gimplify_init_ctor_preeval_data *) xdata;
2275 /* If we find the base object, obviously we have overlap. */
2276 if (data->lhs_base_decl == t)
2279 /* If the constructor component is indirect, determine if we have a
2280 potential overlap with the lhs. The only bits of information we
2281 have to go on at this point are addressability and alias sets. */
2282 if (TREE_CODE (t) == INDIRECT_REF
2283 && (!data->lhs_base_decl || TREE_ADDRESSABLE (data->lhs_base_decl))
2284 && alias_sets_conflict_p (data->lhs_alias_set, get_alias_set (t)))
2287 if (IS_TYPE_OR_DECL_P (t))
2292 /* A subroutine of gimplify_init_constructor. Pre-evaluate *EXPR_P,
2293 force values that overlap with the lhs (as described by *DATA)
2294 into temporaries. */
2297 gimplify_init_ctor_preeval (tree *expr_p, tree *pre_p, tree *post_p,
2298 struct gimplify_init_ctor_preeval_data *data)
2300 enum gimplify_status one;
2302 /* If the value is invariant, then there's nothing to pre-evaluate.
2303 But ensure it doesn't have any side-effects since a SAVE_EXPR is
2304 invariant but has side effects and might contain a reference to
2305 the object we're initializing. */
2306 if (TREE_INVARIANT (*expr_p) && !TREE_SIDE_EFFECTS (*expr_p))
2309 /* If the type has non-trivial constructors, we can't pre-evaluate. */
2310 if (TREE_ADDRESSABLE (TREE_TYPE (*expr_p)))
2313 /* Recurse for nested constructors. */
2314 if (TREE_CODE (*expr_p) == CONSTRUCTOR)
2317 for (list = CONSTRUCTOR_ELTS (*expr_p); list ; list = TREE_CHAIN (list))
2318 gimplify_init_ctor_preeval (&TREE_VALUE (list), pre_p, post_p, data);
2322 /* We can't preevaluate if the type contains a placeholder. */
2323 if (type_contains_placeholder_p (TREE_TYPE (*expr_p)))
2326 /* Gimplify the constructor element to something appropriate for the rhs
2327 of a MODIFY_EXPR. Given that we know the lhs is an aggregate, we know
2328 the gimplifier will consider this a store to memory. Doing this
2329 gimplification now means that we won't have to deal with complicated
2330 language-specific trees, nor trees like SAVE_EXPR that can induce
2331 exponential search behavior. */
2332 one = gimplify_expr (expr_p, pre_p, post_p, is_gimple_mem_rhs, fb_rvalue);
2333 if (one == GS_ERROR)
2339 /* If we gimplified to a bare decl, we can be sure that it doesn't overlap
2340 with the lhs, since "a = { .x=a }" doesn't make sense. This will
2341 always be true for all scalars, since is_gimple_mem_rhs insists on a
2342 temporary variable for them. */
2343 if (DECL_P (*expr_p))
2346 /* If this is of variable size, we have no choice but to assume it doesn't
2347 overlap since we can't make a temporary for it. */
2348 if (!TREE_CONSTANT (TYPE_SIZE (TREE_TYPE (*expr_p))))
2351 /* Otherwise, we must search for overlap ... */
2352 if (!walk_tree (expr_p, gimplify_init_ctor_preeval_1, data, NULL))
2355 /* ... and if found, force the value into a temporary. */
2356 *expr_p = get_formal_tmp_var (*expr_p, pre_p);
2359 /* A subroutine of gimplify_init_constructor. Generate individual
2360 MODIFY_EXPRs for a CONSTRUCTOR. OBJECT is the LHS against which the
2361 assignments should happen. LIST is the CONSTRUCTOR_ELTS of the
2362 CONSTRUCTOR. CLEARED is true if the entire LHS object has been
2366 gimplify_init_ctor_eval (tree object, tree list, tree *pre_p, bool cleared)
2368 tree array_elt_type = NULL;
2370 if (TREE_CODE (TREE_TYPE (object)) == ARRAY_TYPE)
2371 array_elt_type = TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (object)));
2373 for (; list; list = TREE_CHAIN (list))
2375 tree purpose, value, cref, init;
2377 purpose = TREE_PURPOSE (list);
2378 value = TREE_VALUE (list);
2380 /* NULL values are created above for gimplification errors. */
2384 if (cleared && initializer_zerop (value))
2389 /* ??? Here's to hoping the front end fills in all of the indicies,
2390 so we don't have to figure out what's missing ourselves. */
2391 gcc_assert (purpose);
2392 /* ??? Need to handle this. */
2393 gcc_assert (TREE_CODE (purpose) != RANGE_EXPR);
2395 cref = build (ARRAY_REF, array_elt_type, unshare_expr (object),
2396 purpose, NULL_TREE, NULL_TREE);
2399 cref = build (COMPONENT_REF, TREE_TYPE (purpose),
2400 unshare_expr (object), purpose, NULL_TREE);
2402 if (TREE_CODE (value) == CONSTRUCTOR)
2403 gimplify_init_ctor_eval (cref, CONSTRUCTOR_ELTS (value),
2407 init = build (MODIFY_EXPR, TREE_TYPE (cref), cref, value);
2408 gimplify_and_add (init, pre_p);
2413 /* A subroutine of gimplify_modify_expr. Break out elements of a
2414 CONSTRUCTOR used as an initializer into separate MODIFY_EXPRs.
2416 Note that we still need to clear any elements that don't have explicit
2417 initializers, so if not all elements are initialized we keep the
2418 original MODIFY_EXPR, we just remove all of the constructor elements. */
2420 static enum gimplify_status
2421 gimplify_init_constructor (tree *expr_p, tree *pre_p,
2422 tree *post_p, bool want_value)
2425 tree ctor = TREE_OPERAND (*expr_p, 1);
2426 tree type = TREE_TYPE (ctor);
2427 enum gimplify_status ret;
2430 if (TREE_CODE (ctor) != CONSTRUCTOR)
2431 return GS_UNHANDLED;
2433 ret = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p, post_p,
2434 is_gimple_lvalue, fb_lvalue);
2435 if (ret == GS_ERROR)
2437 object = TREE_OPERAND (*expr_p, 0);
2439 elt_list = CONSTRUCTOR_ELTS (ctor);
2442 switch (TREE_CODE (type))
2446 case QUAL_UNION_TYPE:
2449 struct gimplify_init_ctor_preeval_data preeval_data;
2450 HOST_WIDE_INT num_elements, num_nonzero_elements;
2451 HOST_WIDE_INT num_nonconstant_elements;
2454 /* Aggregate types must lower constructors to initialization of
2455 individual elements. The exception is that a CONSTRUCTOR node
2456 with no elements indicates zero-initialization of the whole. */
2457 if (elt_list == NULL)
2460 categorize_ctor_elements (ctor, &num_nonzero_elements,
2461 &num_nonconstant_elements);
2463 /* If a const aggregate variable is being initialized, then it
2464 should never be a lose to promote the variable to be static. */
2465 if (num_nonconstant_elements == 0
2466 && TREE_READONLY (object)
2467 && TREE_CODE (object) == VAR_DECL)
2469 DECL_INITIAL (object) = ctor;
2470 TREE_STATIC (object) = 1;
2471 if (!DECL_NAME (object))
2472 DECL_NAME (object) = create_tmp_var_name ("C");
2473 walk_tree (&DECL_INITIAL (object), force_labels_r, NULL, NULL);
2475 /* ??? C++ doesn't automatically append a .<number> to the
2476 assembler name, and even when it does, it looks a FE private
2477 data structures to figure out what that number should be,
2478 which are not set for this variable. I suppose this is
2479 important for local statics for inline functions, which aren't
2480 "local" in the object file sense. So in order to get a unique
2481 TU-local symbol, we must invoke the lhd version now. */
2482 lhd_set_decl_assembler_name (object);
2484 *expr_p = NULL_TREE;
2488 /* If there are "lots" of initialized elements, and all of them
2489 are valid address constants, then the entire initializer can
2490 be dropped to memory, and then memcpy'd out. */
2491 if (num_nonconstant_elements == 0)
2493 HOST_WIDE_INT size = int_size_in_bytes (type);
2496 /* ??? We can still get unbounded array types, at least
2497 from the C++ front end. This seems wrong, but attempt
2498 to work around it for now. */
2501 size = int_size_in_bytes (TREE_TYPE (object));
2503 TREE_TYPE (ctor) = type = TREE_TYPE (object);
2506 /* Find the maximum alignment we can assume for the object. */
2507 /* ??? Make use of DECL_OFFSET_ALIGN. */
2508 if (DECL_P (object))
2509 align = DECL_ALIGN (object);
2511 align = TYPE_ALIGN (type);
2513 if (size > 0 && !can_move_by_pieces (size, align))
2515 tree new = create_tmp_var_raw (type, "C");
2517 gimple_add_tmp_var (new);
2518 TREE_STATIC (new) = 1;
2519 TREE_READONLY (new) = 1;
2520 DECL_INITIAL (new) = ctor;
2521 if (align > DECL_ALIGN (new))
2523 DECL_ALIGN (new) = align;
2524 DECL_USER_ALIGN (new) = 1;
2526 walk_tree (&DECL_INITIAL (new), force_labels_r, NULL, NULL);
2528 TREE_OPERAND (*expr_p, 1) = new;
2530 /* This is no longer an assignment of a CONSTRUCTOR, but
2531 we still may have processing to do on the LHS. So
2532 pretend we didn't do anything here to let that happen. */
2533 return GS_UNHANDLED;
2537 /* If there are "lots" of initialized elements, even discounting
2538 those that are not address constants (and thus *must* be
2539 computed at runtime), then partition the constructor into
2540 constant and non-constant parts. Block copy the constant
2541 parts in, then generate code for the non-constant parts. */
2542 /* TODO. There's code in cp/typeck.c to do this. */
2544 num_elements = count_type_elements (TREE_TYPE (ctor));
2546 /* If there are "lots" of zeros, then block clear the object first. */
2548 if (num_elements - num_nonzero_elements > CLEAR_RATIO
2549 && num_nonzero_elements < num_elements/4)
2552 /* ??? This bit ought not be needed. For any element not present
2553 in the initializer, we should simply set them to zero. Except
2554 we'd need to *find* the elements that are not present, and that
2555 requires trickery to avoid quadratic compile-time behavior in
2556 large cases or excessive memory use in small cases. */
2559 HOST_WIDE_INT len = list_length (elt_list);
2560 if (TREE_CODE (type) == ARRAY_TYPE)
2562 tree nelts = array_type_nelts (type);
2563 if (!host_integerp (nelts, 1)
2564 || tree_low_cst (nelts, 1) + 1 != len)
2567 else if (len != fields_length (type))
2573 /* Zap the CONSTRUCTOR element list, which simplifies this case.
2574 Note that we still have to gimplify, in order to handle the
2575 case of variable sized types. Avoid shared tree structures. */
2576 CONSTRUCTOR_ELTS (ctor) = NULL_TREE;
2577 object = unshare_expr (object);
2578 gimplify_stmt (expr_p);
2579 append_to_statement_list (*expr_p, pre_p);
2582 preeval_data.lhs_base_decl = get_base_address (object);
2583 if (!DECL_P (preeval_data.lhs_base_decl))
2584 preeval_data.lhs_base_decl = NULL;
2585 preeval_data.lhs_alias_set = get_alias_set (object);
2587 gimplify_init_ctor_preeval (&TREE_OPERAND (*expr_p, 1),
2588 pre_p, post_p, &preeval_data);
2589 gimplify_init_ctor_eval (object, elt_list, pre_p, cleared);
2591 *expr_p = NULL_TREE;
2599 /* Extract the real and imaginary parts out of the ctor. */
2603 r = TREE_VALUE (elt_list);
2604 elt_list = TREE_CHAIN (elt_list);
2607 i = TREE_VALUE (elt_list);
2608 gcc_assert (!TREE_CHAIN (elt_list));
2611 if (r == NULL || i == NULL)
2613 tree zero = convert (TREE_TYPE (type), integer_zero_node);
2620 /* Complex types have either COMPLEX_CST or COMPLEX_EXPR to
2621 represent creation of a complex value. */
2622 if (TREE_CONSTANT (r) && TREE_CONSTANT (i))
2624 ctor = build_complex (type, r, i);
2625 TREE_OPERAND (*expr_p, 1) = ctor;
2629 ctor = build (COMPLEX_EXPR, type, r, i);
2630 TREE_OPERAND (*expr_p, 1) = ctor;
2631 ret = gimplify_expr (&TREE_OPERAND (*expr_p, 1), pre_p, post_p,
2632 rhs_predicate_for (TREE_OPERAND (*expr_p, 0)),
2639 /* Go ahead and simplify constant constructors to VECTOR_CST. */
2640 if (TREE_CONSTANT (ctor))
2641 TREE_OPERAND (*expr_p, 1) = build_vector (type, elt_list);
2644 /* Vector types use CONSTRUCTOR all the way through gimple
2645 compilation as a general initializer. */
2646 for (; elt_list; elt_list = TREE_CHAIN (elt_list))
2648 enum gimplify_status tret;
2649 tret = gimplify_expr (&TREE_VALUE (elt_list), pre_p, post_p,
2650 is_gimple_val, fb_rvalue);
2651 if (tret == GS_ERROR)
2658 /* So how did we get a CONSTRUCTOR for a scalar type? */
2662 if (ret == GS_ERROR)
2664 else if (want_value)
2666 append_to_statement_list (*expr_p, pre_p);
2674 /* Subroutine of gimplify_modify_expr to do simplifications of MODIFY_EXPRs
2675 based on the code of the RHS. We loop for as long as something changes. */
2677 static enum gimplify_status
2678 gimplify_modify_expr_rhs (tree *expr_p, tree *from_p, tree *to_p, tree *pre_p,
2679 tree *post_p, bool want_value)
2681 enum gimplify_status ret = GS_OK;
2683 while (ret != GS_UNHANDLED)
2684 switch (TREE_CODE (*from_p))
2688 /* If we are initializing something from a TARGET_EXPR, strip the
2689 TARGET_EXPR and initialize it directly, if possible. This can't
2690 be done if the initializer is void, since that implies that the
2691 temporary is set in some non-trivial way.
2693 ??? What about code that pulls out the temp and uses it
2694 elsewhere? I think that such code never uses the TARGET_EXPR as
2695 an initializer. If I'm wrong, we'll abort because the temp won't
2696 have any RTL. In that case, I guess we'll need to replace
2697 references somehow. */
2698 tree init = TARGET_EXPR_INITIAL (*from_p);
2700 if (!VOID_TYPE_P (TREE_TYPE (init)))
2711 /* Remove any COMPOUND_EXPR in the RHS so the following cases will be
2713 gimplify_compound_expr (from_p, pre_p, true);
2718 /* If we're initializing from a CONSTRUCTOR, break this into
2719 individual MODIFY_EXPRs. */
2720 return gimplify_init_constructor (expr_p, pre_p, post_p, want_value);
2723 /* If we're assigning to a non-register type, push the assignment
2724 down into the branches. This is mandatory for ADDRESSABLE types,
2725 since we cannot generate temporaries for such, but it saves a
2726 copy in other cases as well. */
2727 if (!is_gimple_reg_type (TREE_TYPE (*from_p)))
2730 return gimplify_cond_expr (expr_p, pre_p, *to_p);
2744 /* Gimplify the MODIFY_EXPR node pointed by EXPR_P.
2750 PRE_P points to the list where side effects that must happen before
2751 *EXPR_P should be stored.
2753 POST_P points to the list where side effects that must happen after
2754 *EXPR_P should be stored.
2756 WANT_VALUE is nonzero iff we want to use the value of this expression
2757 in another expression. */
2759 static enum gimplify_status
2760 gimplify_modify_expr (tree *expr_p, tree *pre_p, tree *post_p, bool want_value)
2762 tree *from_p = &TREE_OPERAND (*expr_p, 1);
2763 tree *to_p = &TREE_OPERAND (*expr_p, 0);
2764 enum gimplify_status ret = GS_UNHANDLED;
2766 gcc_assert (TREE_CODE (*expr_p) == MODIFY_EXPR
2767 || TREE_CODE (*expr_p) == INIT_EXPR);
2769 /* The distinction between MODIFY_EXPR and INIT_EXPR is no longer useful. */
2770 if (TREE_CODE (*expr_p) == INIT_EXPR)
2771 TREE_SET_CODE (*expr_p, MODIFY_EXPR);
2773 /* See if any simplifications can be done based on what the RHS is. */
2774 ret = gimplify_modify_expr_rhs (expr_p, from_p, to_p, pre_p, post_p,
2776 if (ret != GS_UNHANDLED)
2779 /* If the value being copied is of variable width, compute the length
2780 of the copy into a WITH_SIZE_EXPR. Note that we need to do this
2781 before gimplifying any of the operands so that we can resolve any
2782 PLACEHOLDER_EXPRs in the size. Also note that the RTL expander uses
2783 the size of the expression to be copied, not of the destination, so
2784 that is what we must here. */
2785 maybe_with_size_expr (from_p);
2787 ret = gimplify_expr (to_p, pre_p, post_p, is_gimple_lvalue, fb_lvalue);
2788 if (ret == GS_ERROR)
2791 ret = gimplify_expr (from_p, pre_p, post_p,
2792 rhs_predicate_for (*to_p), fb_rvalue);
2793 if (ret == GS_ERROR)
2796 /* Now see if the above changed *from_p to something we handle specially. */
2797 ret = gimplify_modify_expr_rhs (expr_p, from_p, to_p, pre_p, post_p,
2799 if (ret != GS_UNHANDLED)
2802 /* If we've got a variable sized assignment between two lvalues (i.e. does
2803 not involve a call), then we can make things a bit more straightforward
2804 by converting the assignment to memcpy or memset. */
2805 if (TREE_CODE (*from_p) == WITH_SIZE_EXPR)
2807 tree from = TREE_OPERAND (*from_p, 0);
2808 tree size = TREE_OPERAND (*from_p, 1);
2810 if (TREE_CODE (from) == CONSTRUCTOR)
2811 return gimplify_modify_expr_to_memset (expr_p, size, want_value);
2812 if (is_gimple_addressable (from))
2815 return gimplify_modify_expr_to_memcpy (expr_p, size, want_value);
2819 if (gimplify_ctxp->into_ssa && is_gimple_reg (*to_p))
2821 /* If we've somehow already got an SSA_NAME on the LHS, then
2822 we're probably modifying it twice. Not good. */
2823 gcc_assert (TREE_CODE (*to_p) != SSA_NAME);
2824 *to_p = make_ssa_name (*to_p, *expr_p);
2829 append_to_statement_list (*expr_p, pre_p);
2837 /* Gimplify a comparison between two variable-sized objects. Do this
2838 with a call to BUILT_IN_MEMCMP. */
2840 static enum gimplify_status
2841 gimplify_variable_sized_compare (tree *expr_p)
2843 tree op0 = TREE_OPERAND (*expr_p, 0);
2844 tree op1 = TREE_OPERAND (*expr_p, 1);
2847 t = TYPE_SIZE_UNIT (TREE_TYPE (op0));
2848 t = unshare_expr (t);
2849 t = SUBSTITUTE_PLACEHOLDER_IN_EXPR (t, op0);
2850 args = tree_cons (NULL, t, NULL);
2851 t = build_fold_addr_expr (op1);
2852 args = tree_cons (NULL, t, args);
2853 dest = build_fold_addr_expr (op0);
2854 args = tree_cons (NULL, dest, args);
2855 t = implicit_built_in_decls[BUILT_IN_MEMCMP];
2856 t = build_function_call_expr (t, args);
2858 = build (TREE_CODE (*expr_p), TREE_TYPE (*expr_p), t, integer_zero_node);
2863 /* Gimplify TRUTH_ANDIF_EXPR and TRUTH_ORIF_EXPR expressions. EXPR_P
2864 points to the expression to gimplify.
2866 Expressions of the form 'a && b' are gimplified to:
2868 a && b ? true : false
2870 gimplify_cond_expr will do the rest.
2872 PRE_P points to the list where side effects that must happen before
2873 *EXPR_P should be stored. */
2875 static enum gimplify_status
2876 gimplify_boolean_expr (tree *expr_p)
2878 /* Preserve the original type of the expression. */
2879 tree type = TREE_TYPE (*expr_p);
2881 *expr_p = build (COND_EXPR, type, *expr_p,
2882 convert (type, boolean_true_node),
2883 convert (type, boolean_false_node));
2888 /* Gimplifies an expression sequence. This function gimplifies each
2889 expression and re-writes the original expression with the last
2890 expression of the sequence in GIMPLE form.
2892 PRE_P points to the list where the side effects for all the
2893 expressions in the sequence will be emitted.
2895 WANT_VALUE is true when the result of the last COMPOUND_EXPR is used. */
2896 /* ??? Should rearrange to share the pre-queue with all the indirect
2897 invocations of gimplify_expr. Would probably save on creations
2898 of statement_list nodes. */
2900 static enum gimplify_status
2901 gimplify_compound_expr (tree *expr_p, tree *pre_p, bool want_value)
2907 tree *sub_p = &TREE_OPERAND (t, 0);
2909 if (TREE_CODE (*sub_p) == COMPOUND_EXPR)
2910 gimplify_compound_expr (sub_p, pre_p, false);
2912 gimplify_stmt (sub_p);
2913 append_to_statement_list (*sub_p, pre_p);
2915 t = TREE_OPERAND (t, 1);
2917 while (TREE_CODE (t) == COMPOUND_EXPR);
2924 gimplify_stmt (expr_p);
2929 /* Gimplifies a statement list. These may be created either by an
2930 enlightened front-end, or by shortcut_cond_expr. */
2932 static enum gimplify_status
2933 gimplify_statement_list (tree *expr_p)
2935 tree_stmt_iterator i = tsi_start (*expr_p);
2937 while (!tsi_end_p (i))
2941 gimplify_stmt (tsi_stmt_ptr (i));
2946 else if (TREE_CODE (t) == STATEMENT_LIST)
2948 tsi_link_before (&i, t, TSI_SAME_STMT);
2958 /* Gimplify a SAVE_EXPR node. EXPR_P points to the expression to
2959 gimplify. After gimplification, EXPR_P will point to a new temporary
2960 that holds the original value of the SAVE_EXPR node.
2962 PRE_P points to the list where side effects that must happen before
2963 *EXPR_P should be stored. */
2965 static enum gimplify_status
2966 gimplify_save_expr (tree *expr_p, tree *pre_p, tree *post_p)
2968 enum gimplify_status ret = GS_ALL_DONE;
2971 gcc_assert (TREE_CODE (*expr_p) == SAVE_EXPR);
2972 val = TREE_OPERAND (*expr_p, 0);
2974 /* If the SAVE_EXPR has not been resolved, then evaluate it once. */
2975 if (!SAVE_EXPR_RESOLVED_P (*expr_p))
2977 /* The operand may be a void-valued expression such as SAVE_EXPRs
2978 generated by the Java frontend for class initialization. It is
2979 being executed only for its side-effects. */
2980 if (TREE_TYPE (val) == void_type_node)
2982 ret = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p, post_p,
2983 is_gimple_stmt, fb_none);
2984 append_to_statement_list (TREE_OPERAND (*expr_p, 0), pre_p);
2988 val = get_initialized_tmp_var (val, pre_p, post_p);
2990 TREE_OPERAND (*expr_p, 0) = val;
2991 SAVE_EXPR_RESOLVED_P (*expr_p) = 1;
2999 /* Re-write the ADDR_EXPR node pointed by EXPR_P
3006 PRE_P points to the list where side effects that must happen before
3007 *EXPR_P should be stored.
3009 POST_P points to the list where side effects that must happen after
3010 *EXPR_P should be stored. */
3012 static enum gimplify_status
3013 gimplify_addr_expr (tree *expr_p, tree *pre_p, tree *post_p)
3015 tree expr = *expr_p;
3016 tree op0 = TREE_OPERAND (expr, 0);
3017 enum gimplify_status ret;
3019 switch (TREE_CODE (op0))
3022 case MISALIGNED_INDIRECT_REF:
3024 /* Check if we are dealing with an expression of the form '&*ptr'.
3025 While the front end folds away '&*ptr' into 'ptr', these
3026 expressions may be generated internally by the compiler (e.g.,
3027 builtins like __builtin_va_end). */
3028 /* Caution: the silent array decomposition semantics we allow for
3029 ADDR_EXPR means we can't always discard the pair. */
3031 tree op00 = TREE_OPERAND (op0, 0);
3032 tree t_expr = TREE_TYPE (expr);
3033 tree t_op00 = TREE_TYPE (op00);
3035 if (!lang_hooks.types_compatible_p (t_expr, t_op00))
3037 #ifdef ENABLE_CHECKING
3038 tree t_op0 = TREE_TYPE (op0);
3039 gcc_assert (TREE_CODE (t_op0) == ARRAY_TYPE
3040 && POINTER_TYPE_P (t_expr)
3041 && cpt_same_type (TREE_TYPE (t_op0),
3043 && POINTER_TYPE_P (t_op00)
3044 && cpt_same_type (t_op0, TREE_TYPE (t_op00)));
3046 op00 = fold_convert (TREE_TYPE (expr), op00);
3053 case VIEW_CONVERT_EXPR:
3054 /* Take the address of our operand and then convert it to the type of
3057 ??? The interactions of VIEW_CONVERT_EXPR and aliasing is not at
3058 all clear. The impact of this transformation is even less clear. */
3060 /* If the operand is a useless conversion, look through it. Doing so
3061 guarantees that the ADDR_EXPR and its operand will remain of the
3063 if (tree_ssa_useless_type_conversion (TREE_OPERAND (op0, 0)))
3064 op0 = TREE_OPERAND (op0, 0);
3066 *expr_p = fold_convert (TREE_TYPE (expr),
3067 build_fold_addr_expr (TREE_OPERAND (op0, 0)));
3072 /* We use fb_either here because the C frontend sometimes takes
3073 the address of a call that returns a struct; see
3074 gcc.dg/c99-array-lval-1.c. The gimplifier will correctly make
3075 the implied temporary explicit. */
3076 ret = gimplify_expr (&TREE_OPERAND (expr, 0), pre_p, post_p,
3077 is_gimple_addressable, fb_either);
3078 if (ret != GS_ERROR)
3080 op0 = TREE_OPERAND (expr, 0);
3082 /* For various reasons, the gimplification of the expression
3083 may have made a new INDIRECT_REF. */
3084 if (TREE_CODE (op0) == INDIRECT_REF)
3085 goto do_indirect_ref;
3087 /* Make sure TREE_INVARIANT, TREE_CONSTANT, and TREE_SIDE_EFFECTS
3089 recompute_tree_invarant_for_addr_expr (expr);
3091 /* Mark the RHS addressable. */
3092 lang_hooks.mark_addressable (TREE_OPERAND (expr, 0));
3100 /* Gimplify the operands of an ASM_EXPR. Input operands should be a gimple
3101 value; output operands should be a gimple lvalue. */
3103 static enum gimplify_status
3104 gimplify_asm_expr (tree *expr_p, tree *pre_p, tree *post_p)
3106 tree expr = *expr_p;
3107 int noutputs = list_length (ASM_OUTPUTS (expr));
3108 const char **oconstraints
3109 = (const char **) alloca ((noutputs) * sizeof (const char *));
3112 const char *constraint;
3113 bool allows_mem, allows_reg, is_inout;
3114 enum gimplify_status ret, tret;
3117 = resolve_asm_operand_names (ASM_STRING (expr), ASM_OUTPUTS (expr),
3121 for (i = 0, link = ASM_OUTPUTS (expr); link; ++i, link = TREE_CHAIN (link))
3123 oconstraints[i] = constraint
3124 = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (link)));
3126 parse_output_constraint (&constraint, i, 0, 0,
3127 &allows_mem, &allows_reg, &is_inout);
3129 if (!allows_reg && allows_mem)
3130 lang_hooks.mark_addressable (TREE_VALUE (link));
3132 tret = gimplify_expr (&TREE_VALUE (link), pre_p, post_p,
3133 is_inout ? is_gimple_min_lval : is_gimple_lvalue,
3134 fb_lvalue | fb_mayfail);
3135 if (tret == GS_ERROR)
3137 error ("invalid lvalue in asm output %d", i);
3143 /* An input/output operand. To give the optimizers more
3144 flexibility, split it into separate input and output
3148 size_t constraint_len = strlen (constraint);
3150 /* Turn the in/out constraint into an output constraint. */
3151 char *p = xstrdup (constraint);
3153 TREE_VALUE (TREE_PURPOSE (link)) = build_string (constraint_len, p);
3156 /* And add a matching input constraint. */
3159 sprintf (buf, "%d", i);
3160 input = build_string (strlen (buf), buf);
3163 input = build_string (constraint_len - 1, constraint + 1);
3164 input = build_tree_list (build_tree_list (NULL_TREE, input),
3165 unshare_expr (TREE_VALUE (link)));
3166 ASM_INPUTS (expr) = chainon (ASM_INPUTS (expr), input);
3170 for (link = ASM_INPUTS (expr); link; ++i, link = TREE_CHAIN (link))
3173 = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (link)));
3174 parse_input_constraint (&constraint, 0, 0, noutputs, 0,
3175 oconstraints, &allows_mem, &allows_reg);
3177 /* If the operand is a memory input, it should be an lvalue. */
3178 if (!allows_reg && allows_mem)
3180 lang_hooks.mark_addressable (TREE_VALUE (link));
3181 tret = gimplify_expr (&TREE_VALUE (link), pre_p, post_p,
3182 is_gimple_lvalue, fb_lvalue | fb_mayfail);
3183 if (tret == GS_ERROR)
3185 error ("memory input %d is not directly addressable", i);
3191 tret = gimplify_expr (&TREE_VALUE (link), pre_p, post_p,
3192 is_gimple_asm_val, fb_rvalue);
3193 if (tret == GS_ERROR)
3201 /* Gimplify a CLEANUP_POINT_EXPR. Currently this works by adding
3202 WITH_CLEANUP_EXPRs to the prequeue as we encounter cleanups while
3203 gimplifying the body, and converting them to TRY_FINALLY_EXPRs when we
3204 return to this function.
3206 FIXME should we complexify the prequeue handling instead? Or use flags
3207 for all the cleanups and let the optimizer tighten them up? The current
3208 code seems pretty fragile; it will break on a cleanup within any
3209 non-conditional nesting. But any such nesting would be broken, anyway;
3210 we can't write a TRY_FINALLY_EXPR that starts inside a nesting construct
3211 and continues out of it. We can do that at the RTL level, though, so
3212 having an optimizer to tighten up try/finally regions would be a Good
3215 static enum gimplify_status
3216 gimplify_cleanup_point_expr (tree *expr_p, tree *pre_p)
3218 tree_stmt_iterator iter;
3221 tree temp = voidify_wrapper_expr (*expr_p, NULL);
3223 /* We only care about the number of conditions between the innermost
3224 CLEANUP_POINT_EXPR and the cleanup. So save and reset the count. */
3225 int old_conds = gimplify_ctxp->conditions;
3226 gimplify_ctxp->conditions = 0;
3228 body = TREE_OPERAND (*expr_p, 0);
3229 gimplify_to_stmt_list (&body);
3231 gimplify_ctxp->conditions = old_conds;
3233 for (iter = tsi_start (body); !tsi_end_p (iter); )
3235 tree *wce_p = tsi_stmt_ptr (iter);
3238 if (TREE_CODE (wce) == WITH_CLEANUP_EXPR)
3240 if (tsi_one_before_end_p (iter))
3242 tsi_link_before (&iter, TREE_OPERAND (wce, 0), TSI_SAME_STMT);
3249 enum tree_code code;
3251 if (CLEANUP_EH_ONLY (wce))
3252 code = TRY_CATCH_EXPR;
3254 code = TRY_FINALLY_EXPR;
3256 sl = tsi_split_statement_list_after (&iter);
3257 tfe = build (code, void_type_node, sl, NULL_TREE);
3258 append_to_statement_list (TREE_OPERAND (wce, 0),
3259 &TREE_OPERAND (tfe, 1));
3261 iter = tsi_start (sl);
3271 append_to_statement_list (body, pre_p);
3281 /* Insert a cleanup marker for gimplify_cleanup_point_expr. CLEANUP
3282 is the cleanup action required. */
3285 gimple_push_cleanup (tree var, tree cleanup, bool eh_only, tree *pre_p)
3289 /* Errors can result in improperly nested cleanups. Which results in
3290 confusion when trying to resolve the WITH_CLEANUP_EXPR. */
3291 if (errorcount || sorrycount)
3294 if (gimple_conditional_context ())
3296 /* If we're in a conditional context, this is more complex. We only
3297 want to run the cleanup if we actually ran the initialization that
3298 necessitates it, but we want to run it after the end of the
3299 conditional context. So we wrap the try/finally around the
3300 condition and use a flag to determine whether or not to actually
3301 run the destructor. Thus
3305 becomes (approximately)
3309 if (test) { A::A(temp); flag = 1; val = f(temp); }
3312 if (flag) A::~A(temp);
3317 tree flag = create_tmp_var (boolean_type_node, "cleanup");
3318 tree ffalse = build (MODIFY_EXPR, void_type_node, flag,
3319 boolean_false_node);
3320 tree ftrue = build (MODIFY_EXPR, void_type_node, flag,
3322 cleanup = build (COND_EXPR, void_type_node, flag, cleanup, NULL);
3323 wce = build (WITH_CLEANUP_EXPR, void_type_node, cleanup);
3324 append_to_statement_list (ffalse, &gimplify_ctxp->conditional_cleanups);
3325 append_to_statement_list (wce, &gimplify_ctxp->conditional_cleanups);
3326 append_to_statement_list (ftrue, pre_p);
3328 /* Because of this manipulation, and the EH edges that jump
3329 threading cannot redirect, the temporary (VAR) will appear
3330 to be used uninitialized. Don't warn. */
3331 TREE_NO_WARNING (var) = 1;
3335 wce = build (WITH_CLEANUP_EXPR, void_type_node, cleanup);
3336 CLEANUP_EH_ONLY (wce) = eh_only;
3337 append_to_statement_list (wce, pre_p);
3340 gimplify_stmt (&TREE_OPERAND (wce, 0));
3343 /* Gimplify a TARGET_EXPR which doesn't appear on the rhs of an INIT_EXPR. */
3345 static enum gimplify_status
3346 gimplify_target_expr (tree *expr_p, tree *pre_p, tree *post_p)
3348 tree targ = *expr_p;
3349 tree temp = TARGET_EXPR_SLOT (targ);
3350 tree init = TARGET_EXPR_INITIAL (targ);
3351 enum gimplify_status ret;
3355 /* TARGET_EXPR temps aren't part of the enclosing block, so add it
3356 to the temps list. */
3357 gimple_add_tmp_var (temp);
3359 /* If TARGET_EXPR_INITIAL is void, then the mere evaluation of the
3360 expression is supposed to initialize the slot. */
3361 if (VOID_TYPE_P (TREE_TYPE (init)))
3362 ret = gimplify_expr (&init, pre_p, post_p, is_gimple_stmt, fb_none);
3365 /* Special handling for BIND_EXPR can result in fewer temps. */
3367 if (TREE_CODE (init) == BIND_EXPR)
3368 gimplify_bind_expr (&init, temp, pre_p);
3371 init = build (MODIFY_EXPR, void_type_node, temp, init);
3372 ret = gimplify_expr (&init, pre_p, post_p, is_gimple_stmt,
3376 if (ret == GS_ERROR)
3378 append_to_statement_list (init, pre_p);
3380 /* If needed, push the cleanup for the temp. */
3381 if (TARGET_EXPR_CLEANUP (targ))
3383 gimplify_stmt (&TARGET_EXPR_CLEANUP (targ));
3384 gimple_push_cleanup (temp, TARGET_EXPR_CLEANUP (targ),
3385 CLEANUP_EH_ONLY (targ), pre_p);
3388 /* Only expand this once. */
3389 TREE_OPERAND (targ, 3) = init;
3390 TARGET_EXPR_INITIAL (targ) = NULL_TREE;
3393 /* We should have expanded this before. */
3394 gcc_assert (DECL_SEEN_IN_BIND_EXPR_P (temp));
3400 /* Gimplification of expression trees. */
3402 /* Gimplify an expression which appears at statement context; usually, this
3403 means replacing it with a suitably gimple STATEMENT_LIST. */
3406 gimplify_stmt (tree *stmt_p)
3408 gimplify_expr (stmt_p, NULL, NULL, is_gimple_stmt, fb_none);
3411 /* Similarly, but force the result to be a STATEMENT_LIST. */
3414 gimplify_to_stmt_list (tree *stmt_p)
3416 gimplify_stmt (stmt_p);
3418 *stmt_p = alloc_stmt_list ();
3419 else if (TREE_CODE (*stmt_p) != STATEMENT_LIST)
3422 *stmt_p = alloc_stmt_list ();
3423 append_to_statement_list (t, stmt_p);
3428 /* Gimplifies the expression tree pointed by EXPR_P. Return 0 if
3429 gimplification failed.
3431 PRE_P points to the list where side effects that must happen before
3432 EXPR should be stored.
3434 POST_P points to the list where side effects that must happen after
3435 EXPR should be stored, or NULL if there is no suitable list. In
3436 that case, we copy the result to a temporary, emit the
3437 post-effects, and then return the temporary.
3439 GIMPLE_TEST_F points to a function that takes a tree T and
3440 returns nonzero if T is in the GIMPLE form requested by the
3441 caller. The GIMPLE predicates are in tree-gimple.c.
3443 This test is used twice. Before gimplification, the test is
3444 invoked to determine whether *EXPR_P is already gimple enough. If
3445 that fails, *EXPR_P is gimplified according to its code and
3446 GIMPLE_TEST_F is called again. If the test still fails, then a new
3447 temporary variable is created and assigned the value of the
3448 gimplified expression.
3450 FALLBACK tells the function what sort of a temporary we want. If the 1
3451 bit is set, an rvalue is OK. If the 2 bit is set, an lvalue is OK.
3452 If both are set, either is OK, but an lvalue is preferable.
3454 The return value is either GS_ERROR or GS_ALL_DONE, since this function
3455 iterates until solution. */
3457 enum gimplify_status
3458 gimplify_expr (tree *expr_p, tree *pre_p, tree *post_p,
3459 bool (* gimple_test_f) (tree), fallback_t fallback)
3462 tree internal_pre = NULL_TREE;
3463 tree internal_post = NULL_TREE;
3465 int is_statement = (pre_p == NULL);
3466 location_t saved_location;
3467 enum gimplify_status ret;
3469 save_expr = *expr_p;
3470 if (save_expr == NULL_TREE)
3473 /* We used to check the predicate here and return immediately if it
3474 succeeds. This is wrong; the design is for gimplification to be
3475 idempotent, and for the predicates to only test for valid forms, not
3476 whether they are fully simplified. */
3478 /* Set up our internal queues if needed. */
3480 pre_p = &internal_pre;
3482 post_p = &internal_post;
3484 saved_location = input_location;
3485 if (save_expr != error_mark_node
3486 && EXPR_HAS_LOCATION (*expr_p))
3487 input_location = EXPR_LOCATION (*expr_p);
3489 /* Loop over the specific gimplifiers until the toplevel node
3490 remains the same. */
3493 /* Strip away as many useless type conversions as possible
3495 STRIP_USELESS_TYPE_CONVERSION (*expr_p);
3497 /* Remember the expr. */
3498 save_expr = *expr_p;
3500 /* Die, die, die, my darling. */
3501 if (save_expr == error_mark_node
3502 || (TREE_TYPE (save_expr)
3503 && TREE_TYPE (save_expr) == error_mark_node))
3509 /* Do any language-specific gimplification. */
3510 ret = lang_hooks.gimplify_expr (expr_p, pre_p, post_p);
3513 if (*expr_p == NULL_TREE)
3515 if (*expr_p != save_expr)
3518 else if (ret != GS_UNHANDLED)
3522 switch (TREE_CODE (*expr_p))
3524 /* First deal with the special cases. */
3526 case POSTINCREMENT_EXPR:
3527 case POSTDECREMENT_EXPR:
3528 case PREINCREMENT_EXPR:
3529 case PREDECREMENT_EXPR:
3530 ret = gimplify_self_mod_expr (expr_p, pre_p, post_p,
3531 fallback != fb_none);
3535 case ARRAY_RANGE_REF:
3539 case VIEW_CONVERT_EXPR:
3540 ret = gimplify_compound_lval (expr_p, pre_p, post_p,
3541 fallback ? fallback : fb_rvalue);
3545 ret = gimplify_cond_expr (expr_p, pre_p, NULL_TREE);
3549 ret = gimplify_call_expr (expr_p, pre_p, fallback != fb_none);
3556 ret = gimplify_compound_expr (expr_p, pre_p, fallback != fb_none);
3561 ret = gimplify_modify_expr (expr_p, pre_p, post_p,
3562 fallback != fb_none);
3565 case TRUTH_ANDIF_EXPR:
3566 case TRUTH_ORIF_EXPR:
3567 ret = gimplify_boolean_expr (expr_p);
3570 case TRUTH_NOT_EXPR:
3571 TREE_OPERAND (*expr_p, 0)
3572 = gimple_boolify (TREE_OPERAND (*expr_p, 0));
3573 ret = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p, post_p,
3574 is_gimple_val, fb_rvalue);
3575 recalculate_side_effects (*expr_p);
3579 ret = gimplify_addr_expr (expr_p, pre_p, post_p);
3583 ret = gimplify_va_arg_expr (expr_p, pre_p, post_p);
3588 if (IS_EMPTY_STMT (*expr_p))
3594 if (VOID_TYPE_P (TREE_TYPE (*expr_p))
3595 || fallback == fb_none)
3597 /* Just strip a conversion to void (or in void context) and
3599 *expr_p = TREE_OPERAND (*expr_p, 0);
3603 ret = gimplify_conversion (expr_p);
3604 if (ret == GS_ERROR)
3606 if (*expr_p != save_expr)
3610 case FIX_TRUNC_EXPR:
3612 case FIX_FLOOR_EXPR:
3613 case FIX_ROUND_EXPR:
3614 /* unary_expr: ... | '(' cast ')' val | ... */
3615 ret = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p, post_p,
3616 is_gimple_val, fb_rvalue);
3617 recalculate_side_effects (*expr_p);
3620 case ALIGN_INDIRECT_REF:
3621 case MISALIGNED_INDIRECT_REF:
3623 ret = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p, post_p,
3624 is_gimple_reg, fb_rvalue);
3625 recalculate_side_effects (*expr_p);
3628 /* Constants need not be gimplified. */
3638 /* If we require an lvalue, such as for ADDR_EXPR, retain the
3639 CONST_DECL node. Otherwise the decl is replaceable by its
3641 /* ??? Should be == fb_lvalue, but ADDR_EXPR passes fb_either. */
3642 if (fallback & fb_lvalue)
3645 *expr_p = DECL_INITIAL (*expr_p);
3649 ret = gimplify_decl_expr (expr_p);
3653 /* FIXME make this a decl. */
3658 ret = gimplify_bind_expr (expr_p, NULL, pre_p);
3662 ret = gimplify_loop_expr (expr_p, pre_p);
3666 ret = gimplify_switch_expr (expr_p, pre_p);
3670 ret = gimplify_exit_expr (expr_p);
3674 /* If the target is not LABEL, then it is a computed jump
3675 and the target needs to be gimplified. */
3676 if (TREE_CODE (GOTO_DESTINATION (*expr_p)) != LABEL_DECL)
3677 ret = gimplify_expr (&GOTO_DESTINATION (*expr_p), pre_p,
3678 NULL, is_gimple_val, fb_rvalue);
3683 gcc_assert (decl_function_context (LABEL_EXPR_LABEL (*expr_p))
3684 == current_function_decl);
3687 case CASE_LABEL_EXPR:
3688 ret = gimplify_case_label_expr (expr_p);
3692 ret = gimplify_return_expr (*expr_p, pre_p);
3696 /* Don't reduce this in place; let gimplify_init_constructor work its
3697 magic. Buf if we're just elaborating this for side effects, just
3698 gimplify any element that has side-effects. */
3699 if (fallback == fb_none)
3701 for (tmp = CONSTRUCTOR_ELTS (*expr_p); tmp;
3702 tmp = TREE_CHAIN (tmp))
3703 if (TREE_SIDE_EFFECTS (TREE_VALUE (tmp)))
3704 gimplify_expr (&TREE_VALUE (tmp), pre_p, post_p,
3705 gimple_test_f, fallback);
3707 *expr_p = NULL_TREE;
3713 /* The following are special cases that are not handled by the
3714 original GIMPLE grammar. */
3716 /* SAVE_EXPR nodes are converted into a GIMPLE identifier and
3719 ret = gimplify_save_expr (expr_p, pre_p, post_p);
3724 enum gimplify_status r0, r1, r2;
3726 r0 = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p, post_p,
3727 is_gimple_lvalue, fb_either);
3728 r1 = gimplify_expr (&TREE_OPERAND (*expr_p, 1), pre_p, post_p,
3729 is_gimple_val, fb_rvalue);
3730 r2 = gimplify_expr (&TREE_OPERAND (*expr_p, 2), pre_p, post_p,
3731 is_gimple_val, fb_rvalue);
3732 recalculate_side_effects (*expr_p);
3734 ret = MIN (r0, MIN (r1, r2));
3738 case NON_LVALUE_EXPR:
3739 /* This should have been stripped above. */
3743 ret = gimplify_asm_expr (expr_p, pre_p, post_p);
3746 case TRY_FINALLY_EXPR:
3747 case TRY_CATCH_EXPR:
3748 gimplify_to_stmt_list (&TREE_OPERAND (*expr_p, 0));
3749 gimplify_to_stmt_list (&TREE_OPERAND (*expr_p, 1));
3753 case CLEANUP_POINT_EXPR:
3754 ret = gimplify_cleanup_point_expr (expr_p, pre_p);
3758 ret = gimplify_target_expr (expr_p, pre_p, post_p);
3762 gimplify_to_stmt_list (&CATCH_BODY (*expr_p));
3766 case EH_FILTER_EXPR:
3767 gimplify_to_stmt_list (&EH_FILTER_FAILURE (*expr_p));
3773 enum gimplify_status r0, r1;
3774 r0 = gimplify_expr (&OBJ_TYPE_REF_OBJECT (*expr_p), pre_p, post_p,
3775 is_gimple_val, fb_rvalue);
3776 r1 = gimplify_expr (&OBJ_TYPE_REF_EXPR (*expr_p), pre_p, post_p,
3777 is_gimple_val, fb_rvalue);
3783 /* We get here when taking the address of a label. We mark
3784 the label as "forced"; meaning it can never be removed and
3785 it is a potential target for any computed goto. */
3786 FORCED_LABEL (*expr_p) = 1;
3790 case STATEMENT_LIST:
3791 ret = gimplify_statement_list (expr_p);
3794 case WITH_SIZE_EXPR:
3796 enum gimplify_status r0, r1;
3797 r0 = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p,
3798 post_p == &internal_post ? NULL : post_p,
3799 gimple_test_f, fallback);
3800 r1 = gimplify_expr (&TREE_OPERAND (*expr_p, 1), pre_p, post_p,
3801 is_gimple_val, fb_rvalue);
3806 /* ??? If this is a local variable, and it has not been seen in any
3807 outer BIND_EXPR, then it's probably the result of a duplicate
3808 declaration, for which we've already issued an error. It would
3809 be really nice if the front end wouldn't leak these at all.
3810 Currently the only known culprit is C++ destructors, as seen
3811 in g++.old-deja/g++.jason/binding.C. */
3813 if (!TREE_STATIC (tmp) && !DECL_EXTERNAL (tmp)
3814 && decl_function_context (tmp) == current_function_decl
3815 && !DECL_SEEN_IN_BIND_EXPR_P (tmp))
3817 gcc_assert (errorcount || sorrycount);
3822 /* If this is a local variable sized decl, it must be accessed
3823 indirectly. Perform that substitution. */
3824 if (DECL_VALUE_EXPR (tmp))
3826 *expr_p = unshare_expr (DECL_VALUE_EXPR (tmp));
3835 /* Allow callbacks into the gimplifier during optimization. */
3840 switch (TREE_CODE_CLASS (TREE_CODE (*expr_p)))
3842 case tcc_comparison:
3843 /* If this is a comparison of objects of aggregate type,
3844 handle it specially (by converting to a call to
3845 memcmp). It would be nice to only have to do this
3846 for variable-sized objects, but then we'd have to
3847 allow the same nest of reference nodes we allow for
3848 MODIFY_EXPR and that's too complex. */
3849 if (!AGGREGATE_TYPE_P (TREE_TYPE (TREE_OPERAND (*expr_p, 1))))
3851 ret = gimplify_variable_sized_compare (expr_p);
3854 /* If *EXPR_P does not need to be special-cased, handle it
3855 according to its class. */
3857 ret = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p,
3858 post_p, is_gimple_val, fb_rvalue);
3864 enum gimplify_status r0, r1;
3866 r0 = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p,
3867 post_p, is_gimple_val, fb_rvalue);
3868 r1 = gimplify_expr (&TREE_OPERAND (*expr_p, 1), pre_p,
3869 post_p, is_gimple_val, fb_rvalue);
3875 case tcc_declaration:
3878 goto dont_recalculate;
3881 gcc_assert (TREE_CODE (*expr_p) == TRUTH_AND_EXPR
3882 || TREE_CODE (*expr_p) == TRUTH_OR_EXPR
3883 || TREE_CODE (*expr_p) == TRUTH_XOR_EXPR);
3887 recalculate_side_effects (*expr_p);
3892 /* If we replaced *expr_p, gimplify again. */
3893 if (ret == GS_OK && (*expr_p == NULL || *expr_p == save_expr))
3896 while (ret == GS_OK);
3898 /* If we encountered an error_mark somewhere nested inside, either
3899 stub out the statement or propagate the error back out. */
3900 if (ret == GS_ERROR)
3907 /* This was only valid as a return value from the langhook, which
3908 we handled. Make sure it doesn't escape from any other context. */
3909 gcc_assert (ret != GS_UNHANDLED);
3911 if (fallback == fb_none && *expr_p && !is_gimple_stmt (*expr_p))
3913 /* We aren't looking for a value, and we don't have a valid
3914 statement. If it doesn't have side-effects, throw it away. */
3915 if (!TREE_SIDE_EFFECTS (*expr_p))
3917 else if (!TREE_THIS_VOLATILE (*expr_p))
3919 /* This is probably a _REF that contains something nested that
3920 has side effects. Recurse through the operands to find it. */
3921 enum tree_code code = TREE_CODE (*expr_p);
3926 case REALPART_EXPR: case IMAGPART_EXPR:
3927 gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p, post_p,
3928 gimple_test_f, fallback);
3931 case ARRAY_REF: case ARRAY_RANGE_REF:
3932 gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p, post_p,
3933 gimple_test_f, fallback);
3934 gimplify_expr (&TREE_OPERAND (*expr_p, 1), pre_p, post_p,
3935 gimple_test_f, fallback);
3939 /* Anything else with side-effects must be converted to
3940 a valid statement before we get here. */
3946 else if (COMPLETE_TYPE_P (TREE_TYPE (*expr_p)))
3948 /* Historically, the compiler has treated a bare
3949 reference to a volatile lvalue as forcing a load. */
3950 tree tmp = create_tmp_var (TREE_TYPE (*expr_p), "vol");
3951 *expr_p = build (MODIFY_EXPR, TREE_TYPE (tmp), tmp, *expr_p);
3954 /* We can't do anything useful with a volatile reference to
3955 incomplete type, so just throw it away. */
3959 /* If we are gimplifying at the statement level, we're done. Tack
3960 everything together and replace the original statement with the
3962 if (fallback == fb_none || is_statement)
3964 if (internal_pre || internal_post)
3966 append_to_statement_list (*expr_p, &internal_pre);
3967 append_to_statement_list (internal_post, &internal_pre);
3968 annotate_all_with_locus (&internal_pre, input_location);
3969 *expr_p = internal_pre;
3973 else if (TREE_CODE (*expr_p) == STATEMENT_LIST)
3974 annotate_all_with_locus (expr_p, input_location);
3976 annotate_one_with_locus (*expr_p, input_location);
3980 /* Otherwise we're gimplifying a subexpression, so the resulting value is
3983 /* If it's sufficiently simple already, we're done. Unless we are
3984 handling some post-effects internally; if that's the case, we need to
3985 copy into a temp before adding the post-effects to the tree. */
3986 if (!internal_post && (*gimple_test_f) (*expr_p))
3989 /* Otherwise, we need to create a new temporary for the gimplified
3992 /* We can't return an lvalue if we have an internal postqueue. The
3993 object the lvalue refers to would (probably) be modified by the
3994 postqueue; we need to copy the value out first, which means an
3996 if ((fallback & fb_lvalue) && !internal_post
3997 && is_gimple_addressable (*expr_p))
3999 /* An lvalue will do. Take the address of the expression, store it
4000 in a temporary, and replace the expression with an INDIRECT_REF of
4002 tmp = build_fold_addr_expr (*expr_p);
4003 gimplify_expr (&tmp, pre_p, post_p, is_gimple_reg, fb_rvalue);
4004 *expr_p = build1 (INDIRECT_REF, TREE_TYPE (TREE_TYPE (tmp)), tmp);
4006 else if ((fallback & fb_rvalue) && is_gimple_formal_tmp_rhs (*expr_p))
4008 gcc_assert (!VOID_TYPE_P (TREE_TYPE (*expr_p)));
4010 /* An rvalue will do. Assign the gimplified expression into a new
4011 temporary TMP and replace the original expression with TMP. */
4013 if (internal_post || (fallback & fb_lvalue))
4014 /* The postqueue might change the value of the expression between
4015 the initialization and use of the temporary, so we can't use a
4016 formal temp. FIXME do we care? */
4017 *expr_p = get_initialized_tmp_var (*expr_p, pre_p, post_p);
4019 *expr_p = get_formal_tmp_var (*expr_p, pre_p);
4021 if (TREE_CODE (*expr_p) != SSA_NAME)
4022 DECL_GIMPLE_FORMAL_TEMP_P (*expr_p) = 1;
4026 #ifdef ENABLE_CHECKING
4027 if (!(fallback & fb_mayfail))
4029 fprintf (stderr, "gimplification failed:\n");
4030 print_generic_expr (stderr, *expr_p, 0);
4031 debug_tree (*expr_p);
4032 internal_error ("gimplification failed");
4035 gcc_assert (fallback & fb_mayfail);
4036 /* If this is an asm statement, and the user asked for the
4037 impossible, don't abort. Fail and let gimplify_asm_expr
4043 /* Make sure the temporary matches our predicate. */
4044 gcc_assert ((*gimple_test_f) (*expr_p));
4048 annotate_all_with_locus (&internal_post, input_location);
4049 append_to_statement_list (internal_post, pre_p);
4053 input_location = saved_location;
4057 /* Look through TYPE for variable-sized objects and gimplify each such
4058 size that we find. Add to LIST_P any statements generated. */
4061 gimplify_type_sizes (tree type, tree *list_p)
4065 switch (TREE_CODE (type))
4075 gimplify_one_sizepos (&TYPE_MIN_VALUE (type), list_p);
4076 gimplify_one_sizepos (&TYPE_MAX_VALUE (type), list_p);
4080 /* These anonymous types don't have declarations, so handle them here. */
4081 gimplify_type_sizes (TYPE_DOMAIN (type), list_p);
4086 case QUAL_UNION_TYPE:
4087 for (field = TYPE_FIELDS (type); field; field = TREE_CHAIN (field))
4088 if (TREE_CODE (field) == FIELD_DECL)
4089 gimplify_one_sizepos (&DECL_FIELD_OFFSET (field), list_p);
4096 gimplify_one_sizepos (&TYPE_SIZE (type), list_p);
4097 gimplify_one_sizepos (&TYPE_SIZE_UNIT (type), list_p);
4100 /* Subroutine of the above to gimplify one size or position, *EXPR_P.
4101 We add any required statements to STMT_P. */
4104 gimplify_one_sizepos (tree *expr_p, tree *stmt_p)
4106 /* We don't do anything if the value isn't there, is constant, or contains
4107 A PLACEHOLDER_EXPR. We also don't want to do anything if it's already
4108 a VAR_DECL. If it's a VAR_DECL from another function, the gimplfier
4109 will want to replace it with a new variable, but that will cause problems
4110 if this type is from outside the function. It's OK to have that here. */
4111 if (*expr_p == NULL_TREE || TREE_CONSTANT (*expr_p)
4112 || TREE_CODE (*expr_p) == VAR_DECL
4113 || CONTAINS_PLACEHOLDER_P (*expr_p))
4116 gimplify_expr (expr_p, stmt_p, NULL, is_gimple_val, fb_rvalue);
4119 #ifdef ENABLE_CHECKING
4120 /* Compare types A and B for a "close enough" match. */
4123 cpt_same_type (tree a, tree b)
4125 if (lang_hooks.types_compatible_p (a, b))
4128 /* ??? The C++ FE decomposes METHOD_TYPES to FUNCTION_TYPES and doesn't
4129 link them together. This routine is intended to catch type errors
4130 that will affect the optimizers, and the optimizers don't add new
4131 dereferences of function pointers, so ignore it. */
4132 if ((TREE_CODE (a) == FUNCTION_TYPE || TREE_CODE (a) == METHOD_TYPE)
4133 && (TREE_CODE (b) == FUNCTION_TYPE || TREE_CODE (b) == METHOD_TYPE))
4136 /* ??? The C FE pushes type qualifiers after the fact into the type of
4137 the element from the type of the array. See build_unary_op's handling
4138 of ADDR_EXPR. This seems wrong -- if we were going to do this, we
4139 should have done it when creating the variable in the first place.
4140 Alternately, why aren't the two array types made variants? */
4141 if (TREE_CODE (a) == ARRAY_TYPE && TREE_CODE (b) == ARRAY_TYPE)
4142 return cpt_same_type (TREE_TYPE (a), TREE_TYPE (b));
4144 /* And because of those, we have to recurse down through pointers. */
4145 if (POINTER_TYPE_P (a) && POINTER_TYPE_P (b))
4146 return cpt_same_type (TREE_TYPE (a), TREE_TYPE (b));
4151 /* Check for some cases of the front end missing cast expressions.
4152 The type of a dereference should correspond to the pointer type;
4153 similarly the type of an address should match its object. */
4156 check_pointer_types_r (tree *tp, int *walk_subtrees ATTRIBUTE_UNUSED,
4157 void *data ATTRIBUTE_UNUSED)
4160 tree ptype, otype, dtype;
4162 switch (TREE_CODE (t))
4166 otype = TREE_TYPE (t);
4167 ptype = TREE_TYPE (TREE_OPERAND (t, 0));
4168 dtype = TREE_TYPE (ptype);
4169 gcc_assert (cpt_same_type (otype, dtype));
4173 ptype = TREE_TYPE (t);
4174 otype = TREE_TYPE (TREE_OPERAND (t, 0));
4175 dtype = TREE_TYPE (ptype);
4176 if (!cpt_same_type (otype, dtype))
4178 /* &array is allowed to produce a pointer to the element, rather than
4179 a pointer to the array type. We must allow this in order to
4180 properly represent assigning the address of an array in C into
4181 pointer to the element type. */
4182 gcc_assert (TREE_CODE (otype) == ARRAY_TYPE
4183 && POINTER_TYPE_P (ptype)
4184 && cpt_same_type (TREE_TYPE (otype), dtype));
4198 /* Gimplify the body of statements pointed by BODY_P. FNDECL is the
4199 function decl containing BODY. */
4202 gimplify_body (tree *body_p, tree fndecl)
4204 location_t saved_location = input_location;
4207 timevar_push (TV_TREE_GIMPLIFY);
4208 push_gimplify_context ();
4210 /* Unshare most shared trees in the body and in that of any nested functions.
4211 It would seem we don't have to do this for nested functions because
4212 they are supposed to be output and then the outer function gimplified
4213 first, but the g++ front end doesn't always do it that way. */
4214 unshare_body (body_p, fndecl);
4215 unvisit_body (body_p, fndecl);
4217 /* Make sure input_location isn't set to something wierd. */
4218 input_location = DECL_SOURCE_LOCATION (fndecl);
4220 /* Gimplify the function's body. */
4221 gimplify_stmt (body_p);
4224 /* Unshare again, in case gimplification was sloppy. */
4225 unshare_all_trees (body);
4228 body = alloc_stmt_list ();
4229 else if (TREE_CODE (body) == STATEMENT_LIST)
4231 tree t = expr_only (*body_p);
4236 /* If there isn't an outer BIND_EXPR, add one. */
4237 if (TREE_CODE (body) != BIND_EXPR)
4239 tree b = build (BIND_EXPR, void_type_node, NULL_TREE,
4240 NULL_TREE, NULL_TREE);
4241 TREE_SIDE_EFFECTS (b) = 1;
4242 append_to_statement_list_force (body, &BIND_EXPR_BODY (b));
4247 pop_gimplify_context (body);
4249 #ifdef ENABLE_CHECKING
4250 walk_tree (body_p, check_pointer_types_r, NULL, NULL);
4253 timevar_pop (TV_TREE_GIMPLIFY);
4254 input_location = saved_location;
4257 /* Entry point to the gimplification pass. FNDECL is the FUNCTION_DECL
4258 node for the function we want to gimplify. */
4261 gimplify_function_tree (tree fndecl)
4265 oldfn = current_function_decl;
4266 current_function_decl = fndecl;
4268 gimplify_body (&DECL_SAVED_TREE (fndecl), fndecl);
4270 /* If we're instrumenting function entry/exit, then prepend the call to
4271 the entry hook and wrap the whole function in a TRY_FINALLY_EXPR to
4272 catch the exit hook. */
4273 /* ??? Add some way to ignore exceptions for this TFE. */
4274 if (flag_instrument_function_entry_exit
4275 && ! DECL_NO_INSTRUMENT_FUNCTION_ENTRY_EXIT (fndecl))
4279 tf = build (TRY_FINALLY_EXPR, void_type_node, NULL, NULL);
4280 TREE_SIDE_EFFECTS (tf) = 1;
4281 x = DECL_SAVED_TREE (fndecl);
4282 append_to_statement_list (x, &TREE_OPERAND (tf, 0));
4283 x = implicit_built_in_decls[BUILT_IN_PROFILE_FUNC_EXIT];
4284 x = build_function_call_expr (x, NULL);
4285 append_to_statement_list (x, &TREE_OPERAND (tf, 1));
4287 bind = build (BIND_EXPR, void_type_node, NULL, NULL, NULL);
4288 TREE_SIDE_EFFECTS (bind) = 1;
4289 x = implicit_built_in_decls[BUILT_IN_PROFILE_FUNC_ENTER];
4290 x = build_function_call_expr (x, NULL);
4291 append_to_statement_list (x, &BIND_EXPR_BODY (bind));
4292 append_to_statement_list (tf, &BIND_EXPR_BODY (bind));
4294 DECL_SAVED_TREE (fndecl) = bind;
4297 current_function_decl = oldfn;
4301 /* Expands EXPR to list of gimple statements STMTS. If SIMPLE is true,
4302 force the result to be either ssa_name or an invariant, otherwise
4303 just force it to be a rhs expression. If VAR is not NULL, make the
4304 base variable of the final destination be VAR if suitable. */
4307 force_gimple_operand (tree expr, tree *stmts, bool simple, tree var)
4310 enum gimplify_status ret;
4311 gimple_predicate gimple_test_f;
4315 if (is_gimple_val (expr))
4318 gimple_test_f = simple ? is_gimple_val : is_gimple_reg_rhs;
4320 push_gimplify_context ();
4321 gimplify_ctxp->into_ssa = true;
4324 expr = build (MODIFY_EXPR, TREE_TYPE (var), var, expr);
4326 ret = gimplify_expr (&expr, stmts, NULL,
4327 gimple_test_f, fb_rvalue);
4328 gcc_assert (ret != GS_ERROR);
4330 for (t = gimplify_ctxp->temps; t ; t = TREE_CHAIN (t))
4331 add_referenced_tmp_var (t);
4333 pop_gimplify_context (NULL);
4338 #include "gt-gimplify.h"