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}. T is not NULL. */
220 append_to_statement_list_1 (tree t, tree *list_p)
223 tree_stmt_iterator i;
227 if (t && TREE_CODE (t) == STATEMENT_LIST)
232 *list_p = list = alloc_stmt_list ();
236 tsi_link_after (&i, t, TSI_CONTINUE_LINKING);
239 /* Add T to the end of the list container pointed by LIST_P.
240 If T is an expression with no effects, it is ignored. */
243 append_to_statement_list (tree t, tree *list_p)
245 if (t && TREE_SIDE_EFFECTS (t))
246 append_to_statement_list_1 (t, list_p);
249 /* Similar, but the statement is always added, regardless of side effects. */
252 append_to_statement_list_force (tree t, tree *list_p)
255 append_to_statement_list_1 (t, list_p);
258 /* Both gimplify the statement T and append it to LIST_P. */
261 gimplify_and_add (tree t, tree *list_p)
264 append_to_statement_list (t, list_p);
267 /* Strip off a legitimate source ending from the input string NAME of
268 length LEN. Rather than having to know the names used by all of
269 our front ends, we strip off an ending of a period followed by
270 up to five characters. (Java uses ".class".) */
273 remove_suffix (char *name, int len)
277 for (i = 2; i < 8 && len > i; i++)
279 if (name[len - i] == '.')
281 name[len - i] = '\0';
287 /* Create a nameless artificial label and put it in the current function
288 context. Returns the newly created label. */
291 create_artificial_label (void)
293 tree lab = build_decl (LABEL_DECL, NULL_TREE, void_type_node);
295 DECL_ARTIFICIAL (lab) = 1;
296 DECL_CONTEXT (lab) = current_function_decl;
300 /* Create a new temporary name with PREFIX. Returns an identifier. */
302 static GTY(()) unsigned int tmp_var_id_num;
305 create_tmp_var_name (const char *prefix)
311 char *preftmp = ASTRDUP (prefix);
313 remove_suffix (preftmp, strlen (preftmp));
317 ASM_FORMAT_PRIVATE_NAME (tmp_name, prefix ? prefix : "T", tmp_var_id_num++);
318 return get_identifier (tmp_name);
322 /* Create a new temporary variable declaration of type TYPE.
323 Does NOT push it into the current binding. */
326 create_tmp_var_raw (tree type, const char *prefix)
331 /* Make the type of the variable writable. */
332 new_type = build_type_variant (type, 0, 0);
333 TYPE_ATTRIBUTES (new_type) = TYPE_ATTRIBUTES (type);
335 tmp_var = build_decl (VAR_DECL, prefix ? create_tmp_var_name (prefix) : NULL,
338 /* The variable was declared by the compiler. */
339 DECL_ARTIFICIAL (tmp_var) = 1;
340 /* And we don't want debug info for it. */
341 DECL_IGNORED_P (tmp_var) = 1;
343 /* Make the variable writable. */
344 TREE_READONLY (tmp_var) = 0;
346 DECL_EXTERNAL (tmp_var) = 0;
347 TREE_STATIC (tmp_var) = 0;
348 TREE_USED (tmp_var) = 1;
353 /* Create a new temporary variable declaration of type TYPE. DOES push the
354 variable into the current binding. Further, assume that this is called
355 only from gimplification or optimization, at which point the creation of
356 certain types are bugs. */
359 create_tmp_var (tree type, const char *prefix)
363 /* We don't allow types that are addressable (meaning we can't make copies),
364 incomplete, or of variable size. */
365 gcc_assert (!TREE_ADDRESSABLE (type)
366 && COMPLETE_TYPE_P (type)
367 && TREE_CODE (TYPE_SIZE_UNIT (type)) == INTEGER_CST);
369 tmp_var = create_tmp_var_raw (type, prefix);
370 gimple_add_tmp_var (tmp_var);
374 /* Given a tree, try to return a useful variable name that we can use
375 to prefix a temporary that is being assigned the value of the tree.
376 I.E. given <temp> = &A, return A. */
384 STRIP_NOPS (stripped_decl);
385 if (DECL_P (stripped_decl) && DECL_NAME (stripped_decl))
386 return IDENTIFIER_POINTER (DECL_NAME (stripped_decl));
389 switch (TREE_CODE (stripped_decl))
392 return get_name (TREE_OPERAND (stripped_decl, 0));
400 /* Create a temporary with a name derived from VAL. Subroutine of
401 lookup_tmp_var; nobody else should call this function. */
404 create_tmp_from_val (tree val)
406 return create_tmp_var (TREE_TYPE (val), get_name (val));
409 /* Create a temporary to hold the value of VAL. If IS_FORMAL, try to reuse
410 an existing expression temporary. */
413 lookup_tmp_var (tree val, bool is_formal)
417 /* If not optimizing, never really reuse a temporary. local-alloc
418 won't allocate any variable that is used in more than one basic
419 block, which means it will go into memory, causing much extra
420 work in reload and final and poorer code generation, outweighing
421 the extra memory allocation here. */
422 if (!optimize || !is_formal || TREE_SIDE_EFFECTS (val))
423 ret = create_tmp_from_val (val);
430 slot = htab_find_slot (gimplify_ctxp->temp_htab, (void *)&elt, INSERT);
433 elt_p = xmalloc (sizeof (*elt_p));
435 elt_p->temp = ret = create_tmp_from_val (val);
436 *slot = (void *) elt_p;
440 elt_p = (elt_t *) *slot;
446 DECL_GIMPLE_FORMAL_TEMP_P (ret) = 1;
451 /* Returns a formal temporary variable initialized with VAL. PRE_P is as
452 in gimplify_expr. Only use this function if:
454 1) The value of the unfactored expression represented by VAL will not
455 change between the initialization and use of the temporary, and
456 2) The temporary will not be otherwise modified.
458 For instance, #1 means that this is inappropriate for SAVE_EXPR temps,
459 and #2 means it is inappropriate for && temps.
461 For other cases, use get_initialized_tmp_var instead. */
464 internal_get_tmp_var (tree val, tree *pre_p, tree *post_p, bool is_formal)
468 gimplify_expr (&val, pre_p, post_p, is_gimple_formal_tmp_rhs, fb_rvalue);
470 t = lookup_tmp_var (val, is_formal);
472 mod = build (MODIFY_EXPR, TREE_TYPE (t), t, val);
474 if (EXPR_HAS_LOCATION (val))
475 SET_EXPR_LOCUS (mod, EXPR_LOCUS (val));
477 SET_EXPR_LOCATION (mod, input_location);
479 /* gimplify_modify_expr might want to reduce this further. */
480 gimplify_and_add (mod, pre_p);
482 /* If we're gimplifying into ssa, gimplify_modify_expr will have
483 given our temporary an ssa name. Find and return it. */
484 if (gimplify_ctxp->into_ssa)
485 t = TREE_OPERAND (mod, 0);
491 get_formal_tmp_var (tree val, tree *pre_p)
493 return internal_get_tmp_var (val, pre_p, NULL, true);
496 /* Returns a temporary variable initialized with VAL. PRE_P and POST_P
497 are as in gimplify_expr. */
500 get_initialized_tmp_var (tree val, tree *pre_p, tree *post_p)
502 return internal_get_tmp_var (val, pre_p, post_p, false);
505 /* Declares all the variables in VARS in SCOPE. */
508 declare_tmp_vars (tree vars, tree scope)
515 /* C99 mode puts the default 'return 0;' for main outside the outer
516 braces. So drill down until we find an actual scope. */
517 while (TREE_CODE (scope) == COMPOUND_EXPR)
518 scope = TREE_OPERAND (scope, 0);
520 gcc_assert (TREE_CODE (scope) == BIND_EXPR);
522 temps = nreverse (last);
523 TREE_CHAIN (last) = BIND_EXPR_VARS (scope);
524 BIND_EXPR_VARS (scope) = temps;
529 gimple_add_tmp_var (tree tmp)
531 gcc_assert (!TREE_CHAIN (tmp) && !DECL_SEEN_IN_BIND_EXPR_P (tmp));
533 DECL_CONTEXT (tmp) = current_function_decl;
534 DECL_SEEN_IN_BIND_EXPR_P (tmp) = 1;
538 TREE_CHAIN (tmp) = gimplify_ctxp->temps;
539 gimplify_ctxp->temps = tmp;
544 declare_tmp_vars (tmp, DECL_SAVED_TREE (current_function_decl));
547 /* Determines whether to assign a locus to the statement STMT. */
550 should_carry_locus_p (tree stmt)
552 /* Don't emit a line note for a label. We particularly don't want to
553 emit one for the break label, since it doesn't actually correspond
554 to the beginning of the loop/switch. */
555 if (TREE_CODE (stmt) == LABEL_EXPR)
558 /* Do not annotate empty statements, since it confuses gcov. */
559 if (!TREE_SIDE_EFFECTS (stmt))
566 annotate_one_with_locus (tree t, location_t locus)
568 if (EXPR_P (t) && ! EXPR_HAS_LOCATION (t) && should_carry_locus_p (t))
569 SET_EXPR_LOCATION (t, locus);
573 annotate_all_with_locus (tree *stmt_p, location_t locus)
575 tree_stmt_iterator i;
580 for (i = tsi_start (*stmt_p); !tsi_end_p (i); tsi_next (&i))
582 tree t = tsi_stmt (i);
584 /* Assuming we've already been gimplified, we shouldn't
585 see nested chaining constructs anymore. */
586 gcc_assert (TREE_CODE (t) != STATEMENT_LIST
587 && TREE_CODE (t) != COMPOUND_EXPR);
589 annotate_one_with_locus (t, locus);
593 /* Similar to copy_tree_r() but do not copy SAVE_EXPR or TARGET_EXPR nodes.
594 These nodes model computations that should only be done once. If we
595 were to unshare something like SAVE_EXPR(i++), the gimplification
596 process would create wrong code. */
599 mostly_copy_tree_r (tree *tp, int *walk_subtrees, void *data)
601 enum tree_code code = TREE_CODE (*tp);
602 /* Don't unshare types, decls, constants and SAVE_EXPR nodes. */
603 if (TREE_CODE_CLASS (code) == tcc_type
604 || TREE_CODE_CLASS (code) == tcc_declaration
605 || TREE_CODE_CLASS (code) == tcc_constant
606 || code == SAVE_EXPR || code == TARGET_EXPR
607 /* We can't do anything sensible with a BLOCK used as an expression,
608 but we also can't abort when we see it because of non-expression
609 uses. So just avert our eyes and cross our fingers. Silly Java. */
614 gcc_assert (code != BIND_EXPR);
615 copy_tree_r (tp, walk_subtrees, data);
621 /* Callback for walk_tree to unshare most of the shared trees rooted at
622 *TP. If *TP has been visited already (i.e., TREE_VISITED (*TP) == 1),
623 then *TP is deep copied by calling copy_tree_r.
625 This unshares the same trees as copy_tree_r with the exception of
626 SAVE_EXPR nodes. These nodes model computations that should only be
627 done once. If we were to unshare something like SAVE_EXPR(i++), the
628 gimplification process would create wrong code. */
631 copy_if_shared_r (tree *tp, int *walk_subtrees ATTRIBUTE_UNUSED,
632 void *data ATTRIBUTE_UNUSED)
635 enum tree_code code = TREE_CODE (t);
637 /* Skip types, decls, and constants. But we do want to look at their
638 types and the bounds of types. Mark them as visited so we properly
639 unmark their subtrees on the unmark pass. If we've already seen them,
640 don't look down further. */
641 if (TREE_CODE_CLASS (code) == tcc_type
642 || TREE_CODE_CLASS (code) == tcc_declaration
643 || TREE_CODE_CLASS (code) == tcc_constant)
645 if (TREE_VISITED (t))
648 TREE_VISITED (t) = 1;
651 /* If this node has been visited already, unshare it and don't look
653 else if (TREE_VISITED (t))
655 walk_tree (tp, mostly_copy_tree_r, NULL, NULL);
659 /* Otherwise, mark the tree as visited and keep looking. */
661 TREE_VISITED (t) = 1;
667 unmark_visited_r (tree *tp, int *walk_subtrees ATTRIBUTE_UNUSED,
668 void *data ATTRIBUTE_UNUSED)
670 if (TREE_VISITED (*tp))
671 TREE_VISITED (*tp) = 0;
678 /* Unshare all the trees in BODY_P, a pointer into the body of FNDECL, and the
679 bodies of any nested functions if we are unsharing the entire body of
683 unshare_body (tree *body_p, tree fndecl)
685 struct cgraph_node *cgn = cgraph_node (fndecl);
687 walk_tree (body_p, copy_if_shared_r, NULL, NULL);
688 if (body_p == &DECL_SAVED_TREE (fndecl))
689 for (cgn = cgn->nested; cgn; cgn = cgn->next_nested)
690 unshare_body (&DECL_SAVED_TREE (cgn->decl), cgn->decl);
693 /* Likewise, but mark all trees as not visited. */
696 unvisit_body (tree *body_p, tree fndecl)
698 struct cgraph_node *cgn = cgraph_node (fndecl);
700 walk_tree (body_p, unmark_visited_r, NULL, NULL);
701 if (body_p == &DECL_SAVED_TREE (fndecl))
702 for (cgn = cgn->nested; cgn; cgn = cgn->next_nested)
703 unvisit_body (&DECL_SAVED_TREE (cgn->decl), cgn->decl);
706 /* Unshare T and all the trees reached from T via TREE_CHAIN. */
709 unshare_all_trees (tree t)
711 walk_tree (&t, copy_if_shared_r, NULL, NULL);
712 walk_tree (&t, unmark_visited_r, NULL, NULL);
715 /* Unconditionally make an unshared copy of EXPR. This is used when using
716 stored expressions which span multiple functions, such as BINFO_VTABLE,
717 as the normal unsharing process can't tell that they're shared. */
720 unshare_expr (tree expr)
722 walk_tree (&expr, mostly_copy_tree_r, NULL, NULL);
726 /* A terser interface for building a representation of an exception
730 gimple_build_eh_filter (tree body, tree allowed, tree failure)
734 /* FIXME should the allowed types go in TREE_TYPE? */
735 t = build (EH_FILTER_EXPR, void_type_node, allowed, NULL_TREE);
736 append_to_statement_list (failure, &EH_FILTER_FAILURE (t));
738 t = build (TRY_CATCH_EXPR, void_type_node, NULL_TREE, t);
739 append_to_statement_list (body, &TREE_OPERAND (t, 0));
745 /* WRAPPER is a code such as BIND_EXPR or CLEANUP_POINT_EXPR which can both
746 contain statements and have a value. Assign its value to a temporary
747 and give it void_type_node. Returns the temporary, or NULL_TREE if
748 WRAPPER was already void. */
751 voidify_wrapper_expr (tree wrapper, tree temp)
753 if (!VOID_TYPE_P (TREE_TYPE (wrapper)))
755 tree *p, sub = wrapper;
758 /* Set p to point to the body of the wrapper. */
759 switch (TREE_CODE (sub))
762 /* For a BIND_EXPR, the body is operand 1. */
763 p = &BIND_EXPR_BODY (sub);
767 p = &TREE_OPERAND (sub, 0);
771 /* Advance to the last statement. Set all container types to void. */
772 if (TREE_CODE (*p) == STATEMENT_LIST)
774 tree_stmt_iterator i = tsi_last (*p);
775 p = tsi_end_p (i) ? NULL : tsi_stmt_ptr (i);
779 for (; TREE_CODE (*p) == COMPOUND_EXPR; p = &TREE_OPERAND (*p, 1))
781 TREE_SIDE_EFFECTS (*p) = 1;
782 TREE_TYPE (*p) = void_type_node;
786 if (p == NULL || IS_EMPTY_STMT (*p))
788 /* Look through exception handling. */
789 else if (TREE_CODE (*p) == TRY_FINALLY_EXPR
790 || TREE_CODE (*p) == TRY_CATCH_EXPR)
795 /* The C++ frontend already did this for us. */
796 else if (TREE_CODE (*p) == INIT_EXPR
797 || TREE_CODE (*p) == TARGET_EXPR)
798 temp = TREE_OPERAND (*p, 0);
799 /* If we're returning a dereference, move the dereference
800 outside the wrapper. */
801 else if (TREE_CODE (*p) == INDIRECT_REF)
803 tree ptr = TREE_OPERAND (*p, 0);
804 temp = create_tmp_var (TREE_TYPE (ptr), "retval");
805 *p = build (MODIFY_EXPR, TREE_TYPE (ptr), temp, ptr);
806 temp = build1 (INDIRECT_REF, TREE_TYPE (TREE_TYPE (temp)), temp);
807 /* If this is a BIND_EXPR for a const inline function, it might not
808 have TREE_SIDE_EFFECTS set. That is no longer accurate. */
809 TREE_SIDE_EFFECTS (wrapper) = 1;
814 temp = create_tmp_var (TREE_TYPE (wrapper), "retval");
815 *p = build (MODIFY_EXPR, TREE_TYPE (temp), temp, *p);
816 TREE_SIDE_EFFECTS (wrapper) = 1;
819 TREE_TYPE (wrapper) = void_type_node;
826 /* Prepare calls to builtins to SAVE and RESTORE the stack as well as
827 a temporary through which they communicate. */
830 build_stack_save_restore (tree *save, tree *restore)
832 tree save_call, tmp_var;
835 build_function_call_expr (implicit_built_in_decls[BUILT_IN_STACK_SAVE],
837 tmp_var = create_tmp_var (ptr_type_node, "saved_stack");
839 *save = build (MODIFY_EXPR, ptr_type_node, tmp_var, save_call);
841 build_function_call_expr (implicit_built_in_decls[BUILT_IN_STACK_RESTORE],
842 tree_cons (NULL_TREE, tmp_var, NULL_TREE));
845 /* Gimplify a BIND_EXPR. Just voidify and recurse. */
847 static enum gimplify_status
848 gimplify_bind_expr (tree *expr_p, tree temp, tree *pre_p)
850 tree bind_expr = *expr_p;
851 bool old_save_stack = gimplify_ctxp->save_stack;
854 temp = voidify_wrapper_expr (bind_expr, temp);
856 /* Mark variables seen in this bind expr. */
857 for (t = BIND_EXPR_VARS (bind_expr); t ; t = TREE_CHAIN (t))
858 DECL_SEEN_IN_BIND_EXPR_P (t) = 1;
860 gimple_push_bind_expr (bind_expr);
861 gimplify_ctxp->save_stack = false;
863 gimplify_to_stmt_list (&BIND_EXPR_BODY (bind_expr));
865 if (gimplify_ctxp->save_stack)
867 tree stack_save, stack_restore;
869 /* Save stack on entry and restore it on exit. Add a try_finally
870 block to achieve this. Note that mudflap depends on the
871 format of the emitted code: see mx_register_decls(). */
872 build_stack_save_restore (&stack_save, &stack_restore);
874 t = build (TRY_FINALLY_EXPR, void_type_node,
875 BIND_EXPR_BODY (bind_expr), NULL_TREE);
876 append_to_statement_list (stack_restore, &TREE_OPERAND (t, 1));
878 BIND_EXPR_BODY (bind_expr) = NULL_TREE;
879 append_to_statement_list (stack_save, &BIND_EXPR_BODY (bind_expr));
880 append_to_statement_list (t, &BIND_EXPR_BODY (bind_expr));
883 gimplify_ctxp->save_stack = old_save_stack;
884 gimple_pop_bind_expr ();
889 append_to_statement_list (bind_expr, pre_p);
896 /* Gimplify a RETURN_EXPR. If the expression to be returned is not a
897 GIMPLE value, it is assigned to a new temporary and the statement is
898 re-written to return the temporary.
900 PRE_P points to the list where side effects that must happen before
901 STMT should be stored. */
903 static enum gimplify_status
904 gimplify_return_expr (tree stmt, tree *pre_p)
906 tree ret_expr = TREE_OPERAND (stmt, 0);
907 tree result_decl, result;
909 if (!ret_expr || TREE_CODE (ret_expr) == RESULT_DECL
910 || ret_expr == error_mark_node)
913 if (VOID_TYPE_P (TREE_TYPE (TREE_TYPE (current_function_decl))))
914 result_decl = NULL_TREE;
917 result_decl = TREE_OPERAND (ret_expr, 0);
918 if (TREE_CODE (result_decl) == INDIRECT_REF)
919 /* See through a return by reference. */
920 result_decl = TREE_OPERAND (result_decl, 0);
922 gcc_assert ((TREE_CODE (ret_expr) == MODIFY_EXPR
923 || TREE_CODE (ret_expr) == INIT_EXPR)
924 && TREE_CODE (result_decl) == RESULT_DECL);
927 /* If aggregate_value_p is true, then we can return the bare RESULT_DECL.
928 Recall that aggregate_value_p is FALSE for any aggregate type that is
929 returned in registers. If we're returning values in registers, then
930 we don't want to extend the lifetime of the RESULT_DECL, particularly
931 across another call. In addition, for those aggregates for which
932 hard_function_value generates a PARALLEL, we'll abort during normal
933 expansion of structure assignments; there's special code in expand_return
934 to handle this case that does not exist in expand_expr. */
936 || aggregate_value_p (result_decl, TREE_TYPE (current_function_decl)))
937 result = result_decl;
938 else if (gimplify_ctxp->return_temp)
939 result = gimplify_ctxp->return_temp;
942 result = create_tmp_var (TREE_TYPE (result_decl), NULL);
944 /* ??? With complex control flow (usually involving abnormal edges),
945 we can wind up warning about an uninitialized value for this. Due
946 to how this variable is constructed and initialized, this is never
947 true. Give up and never warn. */
948 TREE_NO_WARNING (result) = 1;
950 gimplify_ctxp->return_temp = result;
953 /* Smash the lhs of the MODIFY_EXPR to the temporary we plan to use.
954 Then gimplify the whole thing. */
955 if (result != result_decl)
956 TREE_OPERAND (ret_expr, 0) = result;
958 gimplify_and_add (TREE_OPERAND (stmt, 0), pre_p);
960 /* If we didn't use a temporary, then the result is just the result_decl.
961 Otherwise we need a simple copy. This should already be gimple. */
962 if (result == result_decl)
965 ret_expr = build (MODIFY_EXPR, TREE_TYPE (result), result_decl, result);
966 TREE_OPERAND (stmt, 0) = ret_expr;
971 /* Gimplifies a DECL_EXPR node *STMT_P by making any necessary allocation
972 and initialization explicit. */
974 static enum gimplify_status
975 gimplify_decl_expr (tree *stmt_p)
978 tree decl = DECL_EXPR_DECL (stmt);
982 if (TREE_TYPE (decl) == error_mark_node)
985 else if (TREE_CODE (decl) == TYPE_DECL)
986 gimplify_type_sizes (TREE_TYPE (decl), stmt_p);
988 else if (TREE_CODE (decl) == VAR_DECL && !DECL_EXTERNAL (decl))
990 tree init = DECL_INITIAL (decl);
992 if (!TREE_CONSTANT (DECL_SIZE (decl)))
994 /* This is a variable-sized decl. Simplify its size and mark it
995 for deferred expansion. Note that mudflap depends on the format
996 of the emitted code: see mx_register_decls(). */
997 tree t, args, addr, ptr_type;
999 /* ??? We really shouldn't need to gimplify the type of the variable
1000 since it already should have been done. But leave this here
1001 for now to avoid disrupting too many things at once. */
1002 if (!TYPE_SIZES_GIMPLIFIED (TREE_TYPE (decl)))
1003 gimplify_type_sizes (TREE_TYPE (decl), stmt_p);
1005 gimplify_one_sizepos (&DECL_SIZE (decl), stmt_p);
1006 gimplify_one_sizepos (&DECL_SIZE_UNIT (decl), stmt_p);
1008 /* All occurrences of this decl in final gimplified code will be
1009 replaced by indirection. Setting DECL_VALUE_EXPR does two
1010 things: First, it lets the rest of the gimplifier know what
1011 replacement to use. Second, it lets the debug info know
1012 where to find the value. */
1013 ptr_type = build_pointer_type (TREE_TYPE (decl));
1014 addr = create_tmp_var (ptr_type, get_name (decl));
1015 DECL_IGNORED_P (addr) = 0;
1016 t = build_fold_indirect_ref (addr);
1017 DECL_VALUE_EXPR (decl) = t;
1019 args = tree_cons (NULL, DECL_SIZE_UNIT (decl), NULL);
1020 t = built_in_decls[BUILT_IN_ALLOCA];
1021 t = build_function_call_expr (t, args);
1022 t = fold_convert (ptr_type, t);
1023 t = build2 (MODIFY_EXPR, void_type_node, addr, t);
1025 gimplify_and_add (t, stmt_p);
1027 /* Indicate that we need to restore the stack level when the
1028 enclosing BIND_EXPR is exited. */
1029 gimplify_ctxp->save_stack = true;
1032 if (init && init != error_mark_node)
1034 if (!TREE_STATIC (decl))
1036 DECL_INITIAL (decl) = NULL_TREE;
1037 init = build (MODIFY_EXPR, void_type_node, decl, init);
1038 gimplify_and_add (init, stmt_p);
1041 /* We must still examine initializers for static variables
1042 as they may contain a label address. */
1043 walk_tree (&init, force_labels_r, NULL, NULL);
1046 /* This decl isn't mentioned in the enclosing block, so add it to the
1047 list of temps. FIXME it seems a bit of a kludge to say that
1048 anonymous artificial vars aren't pushed, but everything else is. */
1049 if (DECL_ARTIFICIAL (decl) && DECL_NAME (decl) == NULL_TREE)
1050 gimple_add_tmp_var (decl);
1056 /* Gimplify a LOOP_EXPR. Normally this just involves gimplifying the body
1057 and replacing the LOOP_EXPR with goto, but if the loop contains an
1058 EXIT_EXPR, we need to append a label for it to jump to. */
1060 static enum gimplify_status
1061 gimplify_loop_expr (tree *expr_p, tree *pre_p)
1063 tree saved_label = gimplify_ctxp->exit_label;
1064 tree start_label = build1 (LABEL_EXPR, void_type_node, NULL_TREE);
1065 tree jump_stmt = build_and_jump (&LABEL_EXPR_LABEL (start_label));
1067 append_to_statement_list (start_label, pre_p);
1069 gimplify_ctxp->exit_label = NULL_TREE;
1071 gimplify_and_add (LOOP_EXPR_BODY (*expr_p), pre_p);
1073 if (gimplify_ctxp->exit_label)
1075 append_to_statement_list (jump_stmt, pre_p);
1076 *expr_p = build1 (LABEL_EXPR, void_type_node, gimplify_ctxp->exit_label);
1079 *expr_p = jump_stmt;
1081 gimplify_ctxp->exit_label = saved_label;
1086 /* Compare two case labels. Because the front end should already have
1087 made sure that case ranges do not overlap, it is enough to only compare
1088 the CASE_LOW values of each case label. */
1091 compare_case_labels (const void *p1, const void *p2)
1093 tree case1 = *(tree *)p1;
1094 tree case2 = *(tree *)p2;
1096 return tree_int_cst_compare (CASE_LOW (case1), CASE_LOW (case2));
1099 /* Sort the case labels in LABEL_VEC in place in ascending order. */
1102 sort_case_labels (tree label_vec)
1104 size_t len = TREE_VEC_LENGTH (label_vec);
1105 tree default_case = TREE_VEC_ELT (label_vec, len - 1);
1107 if (CASE_LOW (default_case))
1111 /* The last label in the vector should be the default case
1113 for (i = 0; i < len; ++i)
1115 tree t = TREE_VEC_ELT (label_vec, i);
1119 TREE_VEC_ELT (label_vec, i) = TREE_VEC_ELT (label_vec, len - 1);
1120 TREE_VEC_ELT (label_vec, len - 1) = default_case;
1126 qsort (&TREE_VEC_ELT (label_vec, 0), len - 1, sizeof (tree),
1127 compare_case_labels);
1130 /* Gimplify a SWITCH_EXPR, and collect a TREE_VEC of the labels it can
1133 static enum gimplify_status
1134 gimplify_switch_expr (tree *expr_p, tree *pre_p)
1136 tree switch_expr = *expr_p;
1137 enum gimplify_status ret;
1139 ret = gimplify_expr (&SWITCH_COND (switch_expr), pre_p, NULL,
1140 is_gimple_val, fb_rvalue);
1142 if (SWITCH_BODY (switch_expr))
1144 varray_type labels, saved_labels;
1145 tree label_vec, default_case = NULL_TREE;
1148 /* If someone can be bothered to fill in the labels, they can
1149 be bothered to null out the body too. */
1150 gcc_assert (!SWITCH_LABELS (switch_expr));
1152 saved_labels = gimplify_ctxp->case_labels;
1153 VARRAY_TREE_INIT (gimplify_ctxp->case_labels, 8, "case_labels");
1155 gimplify_to_stmt_list (&SWITCH_BODY (switch_expr));
1157 labels = gimplify_ctxp->case_labels;
1158 gimplify_ctxp->case_labels = saved_labels;
1160 len = VARRAY_ACTIVE_SIZE (labels);
1162 for (i = 0; i < len; ++i)
1164 tree t = VARRAY_TREE (labels, i);
1167 /* The default case must be the last label in the list. */
1169 VARRAY_TREE (labels, i) = VARRAY_TREE (labels, len - 1);
1175 label_vec = make_tree_vec (len + 1);
1176 SWITCH_LABELS (*expr_p) = label_vec;
1177 append_to_statement_list (switch_expr, pre_p);
1181 /* If the switch has no default label, add one, so that we jump
1182 around the switch body. */
1183 default_case = build (CASE_LABEL_EXPR, void_type_node, NULL_TREE,
1184 NULL_TREE, create_artificial_label ());
1185 append_to_statement_list (SWITCH_BODY (switch_expr), pre_p);
1186 *expr_p = build (LABEL_EXPR, void_type_node,
1187 CASE_LABEL (default_case));
1190 *expr_p = SWITCH_BODY (switch_expr);
1192 for (i = 0; i < len; ++i)
1193 TREE_VEC_ELT (label_vec, i) = VARRAY_TREE (labels, i);
1194 TREE_VEC_ELT (label_vec, len) = default_case;
1196 sort_case_labels (label_vec);
1198 SWITCH_BODY (switch_expr) = NULL;
1201 gcc_assert (SWITCH_LABELS (switch_expr));
1206 static enum gimplify_status
1207 gimplify_case_label_expr (tree *expr_p)
1209 tree expr = *expr_p;
1211 gcc_assert (gimplify_ctxp->case_labels);
1212 VARRAY_PUSH_TREE (gimplify_ctxp->case_labels, expr);
1213 *expr_p = build (LABEL_EXPR, void_type_node, CASE_LABEL (expr));
1217 /* Build a GOTO to the LABEL_DECL pointed to by LABEL_P, building it first
1221 build_and_jump (tree *label_p)
1223 if (label_p == NULL)
1224 /* If there's nowhere to jump, just fall through. */
1227 if (*label_p == NULL_TREE)
1229 tree label = create_artificial_label ();
1233 return build1 (GOTO_EXPR, void_type_node, *label_p);
1236 /* Gimplify an EXIT_EXPR by converting to a GOTO_EXPR inside a COND_EXPR.
1237 This also involves building a label to jump to and communicating it to
1238 gimplify_loop_expr through gimplify_ctxp->exit_label. */
1240 static enum gimplify_status
1241 gimplify_exit_expr (tree *expr_p)
1243 tree cond = TREE_OPERAND (*expr_p, 0);
1246 expr = build_and_jump (&gimplify_ctxp->exit_label);
1247 expr = build (COND_EXPR, void_type_node, cond, expr, NULL_TREE);
1253 /* A helper function to be called via walk_tree. Mark all labels under *TP
1254 as being forced. To be called for DECL_INITIAL of static variables. */
1257 force_labels_r (tree *tp, int *walk_subtrees, void *data ATTRIBUTE_UNUSED)
1261 if (TREE_CODE (*tp) == LABEL_DECL)
1262 FORCED_LABEL (*tp) = 1;
1267 /* *EXPR_P is a COMPONENT_REF being used as an rvalue. If its type is
1268 different from its canonical type, wrap the whole thing inside a
1269 NOP_EXPR and force the type of the COMPONENT_REF to be the canonical
1272 The canonical type of a COMPONENT_REF is the type of the field being
1273 referenced--unless the field is a bit-field which can be read directly
1274 in a smaller mode, in which case the canonical type is the
1275 sign-appropriate type corresponding to that mode. */
1278 canonicalize_component_ref (tree *expr_p)
1280 tree expr = *expr_p;
1283 gcc_assert (TREE_CODE (expr) == COMPONENT_REF);
1285 if (INTEGRAL_TYPE_P (TREE_TYPE (expr)))
1286 type = TREE_TYPE (get_unwidened (expr, NULL_TREE));
1288 type = TREE_TYPE (TREE_OPERAND (expr, 1));
1290 if (TREE_TYPE (expr) != type)
1292 tree old_type = TREE_TYPE (expr);
1294 /* Set the type of the COMPONENT_REF to the underlying type. */
1295 TREE_TYPE (expr) = type;
1297 /* And wrap the whole thing inside a NOP_EXPR. */
1298 expr = build1 (NOP_EXPR, old_type, expr);
1304 /* If a NOP conversion is changing a pointer to array of foo to a pointer
1305 to foo, embed that change in the ADDR_EXPR by converting
1310 where L is the lower bound. For simplicity, only do this for constant
1314 canonicalize_addr_expr (tree *expr_p)
1316 tree expr = *expr_p;
1317 tree ctype = TREE_TYPE (expr);
1318 tree addr_expr = TREE_OPERAND (expr, 0);
1319 tree atype = TREE_TYPE (addr_expr);
1320 tree dctype, datype, ddatype, otype, obj_expr;
1322 /* Both cast and addr_expr types should be pointers. */
1323 if (!POINTER_TYPE_P (ctype) || !POINTER_TYPE_P (atype))
1326 /* The addr_expr type should be a pointer to an array. */
1327 datype = TREE_TYPE (atype);
1328 if (TREE_CODE (datype) != ARRAY_TYPE)
1331 /* Both cast and addr_expr types should address the same object type. */
1332 dctype = TREE_TYPE (ctype);
1333 ddatype = TREE_TYPE (datype);
1334 if (!lang_hooks.types_compatible_p (ddatype, dctype))
1337 /* The addr_expr and the object type should match. */
1338 obj_expr = TREE_OPERAND (addr_expr, 0);
1339 otype = TREE_TYPE (obj_expr);
1340 if (!lang_hooks.types_compatible_p (otype, datype))
1343 /* The lower bound and element sizes must be constant. */
1344 if (!TYPE_SIZE_UNIT (dctype)
1345 || TREE_CODE (TYPE_SIZE_UNIT (dctype)) != INTEGER_CST
1346 || !TYPE_DOMAIN (datype) || !TYPE_MIN_VALUE (TYPE_DOMAIN (datype))
1347 || TREE_CODE (TYPE_MIN_VALUE (TYPE_DOMAIN (datype))) != INTEGER_CST)
1350 /* All checks succeeded. Build a new node to merge the cast. */
1351 *expr_p = build4 (ARRAY_REF, dctype, obj_expr,
1352 TYPE_MIN_VALUE (TYPE_DOMAIN (datype)),
1353 TYPE_MIN_VALUE (TYPE_DOMAIN (datype)),
1354 size_binop (EXACT_DIV_EXPR, TYPE_SIZE_UNIT (dctype),
1355 size_int (TYPE_ALIGN_UNIT (dctype))));
1356 *expr_p = build1 (ADDR_EXPR, ctype, *expr_p);
1359 /* *EXPR_P is a NOP_EXPR or CONVERT_EXPR. Remove it and/or other conversions
1360 underneath as appropriate. */
1362 static enum gimplify_status
1363 gimplify_conversion (tree *expr_p)
1365 gcc_assert (TREE_CODE (*expr_p) == NOP_EXPR
1366 || TREE_CODE (*expr_p) == CONVERT_EXPR);
1368 /* Then strip away all but the outermost conversion. */
1369 STRIP_SIGN_NOPS (TREE_OPERAND (*expr_p, 0));
1371 /* And remove the outermost conversion if it's useless. */
1372 if (tree_ssa_useless_type_conversion (*expr_p))
1373 *expr_p = TREE_OPERAND (*expr_p, 0);
1375 /* If we still have a conversion at the toplevel,
1376 then canonicalize some constructs. */
1377 if (TREE_CODE (*expr_p) == NOP_EXPR || TREE_CODE (*expr_p) == CONVERT_EXPR)
1379 tree sub = TREE_OPERAND (*expr_p, 0);
1381 /* If a NOP conversion is changing the type of a COMPONENT_REF
1382 expression, then canonicalize its type now in order to expose more
1383 redundant conversions. */
1384 if (TREE_CODE (sub) == COMPONENT_REF)
1385 canonicalize_component_ref (&TREE_OPERAND (*expr_p, 0));
1387 /* If a NOP conversion is changing a pointer to array of foo
1388 to a pointer to foo, embed that change in the ADDR_EXPR. */
1389 else if (TREE_CODE (sub) == ADDR_EXPR)
1390 canonicalize_addr_expr (expr_p);
1396 /* Gimplify the COMPONENT_REF, ARRAY_REF, REALPART_EXPR or IMAGPART_EXPR
1397 node pointed by EXPR_P.
1400 : min_lval '[' val ']'
1402 | compound_lval '[' val ']'
1403 | compound_lval '.' ID
1405 This is not part of the original SIMPLE definition, which separates
1406 array and member references, but it seems reasonable to handle them
1407 together. Also, this way we don't run into problems with union
1408 aliasing; gcc requires that for accesses through a union to alias, the
1409 union reference must be explicit, which was not always the case when we
1410 were splitting up array and member refs.
1412 PRE_P points to the list where side effects that must happen before
1413 *EXPR_P should be stored.
1415 POST_P points to the list where side effects that must happen after
1416 *EXPR_P should be stored. */
1418 static enum gimplify_status
1419 gimplify_compound_lval (tree *expr_p, tree *pre_p,
1420 tree *post_p, fallback_t fallback)
1424 enum gimplify_status ret = GS_OK, tret;
1427 /* Create a stack of the subexpressions so later we can walk them in
1428 order from inner to outer.
1430 This array is very memory consuming. Don't even think of making
1432 VARRAY_GENERIC_PTR_NOGC_INIT (stack, 10, "stack");
1434 /* We can handle anything that get_inner_reference can deal with. */
1435 for (p = expr_p; handled_component_p (*p); 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)
1752 tree arglist = TREE_OPERAND (*expr_p, 1);
1754 if (!arglist || !TREE_CHAIN (arglist))
1756 error ("too few arguments to function %<va_start%>");
1757 *expr_p = build_empty_stmt ();
1761 if (fold_builtin_next_arg (TREE_CHAIN (arglist)))
1763 *expr_p = build_empty_stmt ();
1766 /* Avoid gimplifying the second argument to va_start, which needs
1767 to be the plain PARM_DECL. */
1768 return gimplify_arg (&TREE_VALUE (TREE_OPERAND (*expr_p, 1)), pre_p);
1772 /* There is a sequence point before the call, so any side effects in
1773 the calling expression must occur before the actual call. Force
1774 gimplify_expr to use an internal post queue. */
1775 ret = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p, NULL,
1776 is_gimple_call_addr, fb_rvalue);
1778 if (PUSH_ARGS_REVERSED)
1779 TREE_OPERAND (*expr_p, 1) = nreverse (TREE_OPERAND (*expr_p, 1));
1780 for (arglist = TREE_OPERAND (*expr_p, 1); arglist;
1781 arglist = TREE_CHAIN (arglist))
1783 enum gimplify_status t;
1785 t = gimplify_arg (&TREE_VALUE (arglist), pre_p);
1790 if (PUSH_ARGS_REVERSED)
1791 TREE_OPERAND (*expr_p, 1) = nreverse (TREE_OPERAND (*expr_p, 1));
1793 /* Try this again in case gimplification exposed something. */
1794 if (ret != GS_ERROR && decl && DECL_BUILT_IN (decl))
1796 tree new = fold_builtin (*expr_p, !want_value);
1798 if (new && new != *expr_p)
1800 /* There was a transformation of this call which computes the
1801 same value, but in a more efficient way. Return and try
1808 /* If the function is "const" or "pure", then clear TREE_SIDE_EFFECTS on its
1809 decl. This allows us to eliminate redundant or useless
1810 calls to "const" functions. */
1811 if (TREE_CODE (*expr_p) == CALL_EXPR
1812 && (call_expr_flags (*expr_p) & (ECF_CONST | ECF_PURE)))
1813 TREE_SIDE_EFFECTS (*expr_p) = 0;
1818 /* Handle shortcut semantics in the predicate operand of a COND_EXPR by
1819 rewriting it into multiple COND_EXPRs, and possibly GOTO_EXPRs.
1821 TRUE_LABEL_P and FALSE_LABEL_P point to the labels to jump to if the
1822 condition is true or false, respectively. If null, we should generate
1823 our own to skip over the evaluation of this specific expression.
1825 This function is the tree equivalent of do_jump.
1827 shortcut_cond_r should only be called by shortcut_cond_expr. */
1830 shortcut_cond_r (tree pred, tree *true_label_p, tree *false_label_p)
1832 tree local_label = NULL_TREE;
1833 tree t, expr = NULL;
1835 /* OK, it's not a simple case; we need to pull apart the COND_EXPR to
1836 retain the shortcut semantics. Just insert the gotos here;
1837 shortcut_cond_expr will append the real blocks later. */
1838 if (TREE_CODE (pred) == TRUTH_ANDIF_EXPR)
1840 /* Turn if (a && b) into
1842 if (a); else goto no;
1843 if (b) goto yes; else goto no;
1846 if (false_label_p == NULL)
1847 false_label_p = &local_label;
1849 t = shortcut_cond_r (TREE_OPERAND (pred, 0), NULL, false_label_p);
1850 append_to_statement_list (t, &expr);
1852 t = shortcut_cond_r (TREE_OPERAND (pred, 1), true_label_p,
1854 append_to_statement_list (t, &expr);
1856 else if (TREE_CODE (pred) == TRUTH_ORIF_EXPR)
1858 /* Turn if (a || b) into
1861 if (b) goto yes; else goto no;
1864 if (true_label_p == NULL)
1865 true_label_p = &local_label;
1867 t = shortcut_cond_r (TREE_OPERAND (pred, 0), true_label_p, NULL);
1868 append_to_statement_list (t, &expr);
1870 t = shortcut_cond_r (TREE_OPERAND (pred, 1), true_label_p,
1872 append_to_statement_list (t, &expr);
1874 else if (TREE_CODE (pred) == COND_EXPR)
1876 /* As long as we're messing with gotos, turn if (a ? b : c) into
1878 if (b) goto yes; else goto no;
1880 if (c) goto yes; else goto no; */
1881 expr = build (COND_EXPR, void_type_node, TREE_OPERAND (pred, 0),
1882 shortcut_cond_r (TREE_OPERAND (pred, 1), true_label_p,
1884 shortcut_cond_r (TREE_OPERAND (pred, 2), true_label_p,
1889 expr = build (COND_EXPR, void_type_node, pred,
1890 build_and_jump (true_label_p),
1891 build_and_jump (false_label_p));
1896 t = build1 (LABEL_EXPR, void_type_node, local_label);
1897 append_to_statement_list (t, &expr);
1904 shortcut_cond_expr (tree expr)
1906 tree pred = TREE_OPERAND (expr, 0);
1907 tree then_ = TREE_OPERAND (expr, 1);
1908 tree else_ = TREE_OPERAND (expr, 2);
1909 tree true_label, false_label, end_label, t;
1911 tree *false_label_p;
1912 bool emit_end, emit_false;
1913 bool then_se = then_ && TREE_SIDE_EFFECTS (then_);
1914 bool else_se = else_ && TREE_SIDE_EFFECTS (else_);
1916 /* First do simple transformations. */
1919 /* If there is no 'else', turn (a && b) into if (a) if (b). */
1920 while (TREE_CODE (pred) == TRUTH_ANDIF_EXPR)
1922 TREE_OPERAND (expr, 0) = TREE_OPERAND (pred, 1);
1923 then_ = shortcut_cond_expr (expr);
1924 pred = TREE_OPERAND (pred, 0);
1925 expr = build (COND_EXPR, void_type_node, pred, then_, NULL_TREE);
1930 /* If there is no 'then', turn
1933 if (a); else if (b); else d. */
1934 while (TREE_CODE (pred) == TRUTH_ORIF_EXPR)
1936 TREE_OPERAND (expr, 0) = TREE_OPERAND (pred, 1);
1937 else_ = shortcut_cond_expr (expr);
1938 pred = TREE_OPERAND (pred, 0);
1939 expr = build (COND_EXPR, void_type_node, pred, NULL_TREE, else_);
1943 /* If we're done, great. */
1944 if (TREE_CODE (pred) != TRUTH_ANDIF_EXPR
1945 && TREE_CODE (pred) != TRUTH_ORIF_EXPR)
1948 /* Otherwise we need to mess with gotos. Change
1951 if (a); else goto no;
1954 and recursively gimplify the condition. */
1956 true_label = false_label = end_label = NULL_TREE;
1958 /* If our arms just jump somewhere, hijack those labels so we don't
1959 generate jumps to jumps. */
1962 && TREE_CODE (then_) == GOTO_EXPR
1963 && TREE_CODE (GOTO_DESTINATION (then_)) == LABEL_DECL)
1965 true_label = GOTO_DESTINATION (then_);
1971 && TREE_CODE (else_) == GOTO_EXPR
1972 && TREE_CODE (GOTO_DESTINATION (else_)) == LABEL_DECL)
1974 false_label = GOTO_DESTINATION (else_);
1979 /* If we aren't hijacking a label for the 'then' branch, it falls through. */
1981 true_label_p = &true_label;
1983 true_label_p = NULL;
1985 /* The 'else' branch also needs a label if it contains interesting code. */
1986 if (false_label || else_se)
1987 false_label_p = &false_label;
1989 false_label_p = NULL;
1991 /* If there was nothing else in our arms, just forward the label(s). */
1992 if (!then_se && !else_se)
1993 return shortcut_cond_r (pred, true_label_p, false_label_p);
1995 /* If our last subexpression already has a terminal label, reuse it. */
1997 expr = expr_last (else_);
1999 expr = expr_last (then_);
2002 if (expr && TREE_CODE (expr) == LABEL_EXPR)
2003 end_label = LABEL_EXPR_LABEL (expr);
2005 /* If we don't care about jumping to the 'else' branch, jump to the end
2006 if the condition is false. */
2008 false_label_p = &end_label;
2010 /* We only want to emit these labels if we aren't hijacking them. */
2011 emit_end = (end_label == NULL_TREE);
2012 emit_false = (false_label == NULL_TREE);
2014 pred = shortcut_cond_r (pred, true_label_p, false_label_p);
2017 append_to_statement_list (pred, &expr);
2019 append_to_statement_list (then_, &expr);
2022 t = build_and_jump (&end_label);
2023 append_to_statement_list (t, &expr);
2026 t = build1 (LABEL_EXPR, void_type_node, false_label);
2027 append_to_statement_list (t, &expr);
2029 append_to_statement_list (else_, &expr);
2031 if (emit_end && end_label)
2033 t = build1 (LABEL_EXPR, void_type_node, end_label);
2034 append_to_statement_list (t, &expr);
2040 /* EXPR is used in a boolean context; make sure it has BOOLEAN_TYPE. */
2043 gimple_boolify (tree expr)
2045 tree type = TREE_TYPE (expr);
2047 if (TREE_CODE (type) == BOOLEAN_TYPE)
2050 /* If this is the predicate of a COND_EXPR, it might not even be a
2052 expr = lang_hooks.truthvalue_conversion (expr);
2054 switch (TREE_CODE (expr))
2056 case TRUTH_AND_EXPR:
2058 case TRUTH_XOR_EXPR:
2059 case TRUTH_ANDIF_EXPR:
2060 case TRUTH_ORIF_EXPR:
2061 /* Also boolify the arguments of truth exprs. */
2062 TREE_OPERAND (expr, 1) = gimple_boolify (TREE_OPERAND (expr, 1));
2065 case TRUTH_NOT_EXPR:
2066 TREE_OPERAND (expr, 0) = gimple_boolify (TREE_OPERAND (expr, 0));
2069 case EQ_EXPR: case NE_EXPR:
2070 case LE_EXPR: case GE_EXPR: case LT_EXPR: case GT_EXPR:
2071 /* These expressions always produce boolean results. */
2072 TREE_TYPE (expr) = boolean_type_node;
2076 /* Other expressions that get here must have boolean values, but
2077 might need to be converted to the appropriate mode. */
2078 return convert (boolean_type_node, expr);
2082 /* Convert the conditional expression pointed by EXPR_P '(p) ? a : b;'
2091 The second form is used when *EXPR_P is of type void.
2093 TARGET is the tree for T1 above.
2095 PRE_P points to the list where side effects that must happen before
2096 *EXPR_P should be stored.
2098 POST_P points to the list where side effects that must happen after
2099 *EXPR_P should be stored. */
2101 static enum gimplify_status
2102 gimplify_cond_expr (tree *expr_p, tree *pre_p, tree *post_p, tree target)
2104 tree expr = *expr_p;
2105 tree tmp, tmp2, type;
2106 enum gimplify_status ret;
2108 type = TREE_TYPE (expr);
2110 TREE_TYPE (expr) = void_type_node;
2112 /* If this COND_EXPR has a value, copy the values into a temporary within
2114 else if (! VOID_TYPE_P (type))
2118 ret = gimplify_expr (&target, pre_p, post_p,
2119 is_gimple_min_lval, fb_lvalue);
2120 if (ret != GS_ERROR)
2123 tmp2 = unshare_expr (target);
2127 tmp2 = tmp = create_tmp_var (TREE_TYPE (expr), "iftmp");
2131 /* Build the then clause, 't1 = a;'. But don't build an assignment
2132 if this branch is void; in C++ it can be, if it's a throw. */
2133 if (TREE_TYPE (TREE_OPERAND (expr, 1)) != void_type_node)
2134 TREE_OPERAND (expr, 1)
2135 = build (MODIFY_EXPR, void_type_node, tmp, TREE_OPERAND (expr, 1));
2137 /* Build the else clause, 't1 = b;'. */
2138 if (TREE_TYPE (TREE_OPERAND (expr, 2)) != void_type_node)
2139 TREE_OPERAND (expr, 2)
2140 = build (MODIFY_EXPR, void_type_node, tmp2, TREE_OPERAND (expr, 2));
2142 TREE_TYPE (expr) = void_type_node;
2143 recalculate_side_effects (expr);
2145 /* Move the COND_EXPR to the prequeue. */
2146 gimplify_and_add (expr, pre_p);
2152 /* Make sure the condition has BOOLEAN_TYPE. */
2153 TREE_OPERAND (expr, 0) = gimple_boolify (TREE_OPERAND (expr, 0));
2155 /* Break apart && and || conditions. */
2156 if (TREE_CODE (TREE_OPERAND (expr, 0)) == TRUTH_ANDIF_EXPR
2157 || TREE_CODE (TREE_OPERAND (expr, 0)) == TRUTH_ORIF_EXPR)
2159 expr = shortcut_cond_expr (expr);
2161 if (expr != *expr_p)
2165 /* We can't rely on gimplify_expr to re-gimplify the expanded
2166 form properly, as cleanups might cause the target labels to be
2167 wrapped in a TRY_FINALLY_EXPR. To prevent that, we need to
2168 set up a conditional context. */
2169 gimple_push_condition ();
2170 gimplify_stmt (expr_p);
2171 gimple_pop_condition (pre_p);
2177 /* Now do the normal gimplification. */
2178 ret = gimplify_expr (&TREE_OPERAND (expr, 0), pre_p, NULL,
2179 is_gimple_condexpr, fb_rvalue);
2181 gimple_push_condition ();
2183 gimplify_to_stmt_list (&TREE_OPERAND (expr, 1));
2184 gimplify_to_stmt_list (&TREE_OPERAND (expr, 2));
2185 recalculate_side_effects (expr);
2187 gimple_pop_condition (pre_p);
2189 if (ret == GS_ERROR)
2191 else if (TREE_SIDE_EFFECTS (TREE_OPERAND (expr, 1)))
2193 else if (TREE_SIDE_EFFECTS (TREE_OPERAND (expr, 2)))
2194 /* Rewrite "if (a); else b" to "if (!a) b" */
2196 TREE_OPERAND (expr, 0) = invert_truthvalue (TREE_OPERAND (expr, 0));
2197 ret = gimplify_expr (&TREE_OPERAND (expr, 0), pre_p, NULL,
2198 is_gimple_condexpr, fb_rvalue);
2200 tmp = TREE_OPERAND (expr, 1);
2201 TREE_OPERAND (expr, 1) = TREE_OPERAND (expr, 2);
2202 TREE_OPERAND (expr, 2) = tmp;
2205 /* Both arms are empty; replace the COND_EXPR with its predicate. */
2206 expr = TREE_OPERAND (expr, 0);
2212 /* A subroutine of gimplify_modify_expr. Replace a MODIFY_EXPR with
2213 a call to __builtin_memcpy. */
2215 static enum gimplify_status
2216 gimplify_modify_expr_to_memcpy (tree *expr_p, tree size, bool want_value)
2218 tree args, t, to, to_ptr, from;
2220 to = TREE_OPERAND (*expr_p, 0);
2221 from = TREE_OPERAND (*expr_p, 1);
2223 args = tree_cons (NULL, size, NULL);
2225 t = build_fold_addr_expr (from);
2226 args = tree_cons (NULL, t, args);
2228 to_ptr = build_fold_addr_expr (to);
2229 args = tree_cons (NULL, to_ptr, args);
2230 t = implicit_built_in_decls[BUILT_IN_MEMCPY];
2231 t = build_function_call_expr (t, args);
2235 t = build1 (NOP_EXPR, TREE_TYPE (to_ptr), t);
2236 t = build1 (INDIRECT_REF, TREE_TYPE (to), t);
2243 /* A subroutine of gimplify_modify_expr. Replace a MODIFY_EXPR with
2244 a call to __builtin_memset. In this case we know that the RHS is
2245 a CONSTRUCTOR with an empty element list. */
2247 static enum gimplify_status
2248 gimplify_modify_expr_to_memset (tree *expr_p, tree size, bool want_value)
2250 tree args, t, to, to_ptr;
2252 to = TREE_OPERAND (*expr_p, 0);
2254 args = tree_cons (NULL, size, NULL);
2256 args = tree_cons (NULL, integer_zero_node, args);
2258 to_ptr = build_fold_addr_expr (to);
2259 args = tree_cons (NULL, to_ptr, args);
2260 t = implicit_built_in_decls[BUILT_IN_MEMSET];
2261 t = build_function_call_expr (t, args);
2265 t = build1 (NOP_EXPR, TREE_TYPE (to_ptr), t);
2266 t = build1 (INDIRECT_REF, TREE_TYPE (to), t);
2273 /* A subroutine of gimplify_init_ctor_preeval. Called via walk_tree,
2274 determine, cautiously, if a CONSTRUCTOR overlaps the lhs of an
2275 assignment. Returns non-null if we detect a potential overlap. */
2277 struct gimplify_init_ctor_preeval_data
2279 /* The base decl of the lhs object. May be NULL, in which case we
2280 have to assume the lhs is indirect. */
2283 /* The alias set of the lhs object. */
2288 gimplify_init_ctor_preeval_1 (tree *tp, int *walk_subtrees, void *xdata)
2290 struct gimplify_init_ctor_preeval_data *data
2291 = (struct gimplify_init_ctor_preeval_data *) xdata;
2294 /* If we find the base object, obviously we have overlap. */
2295 if (data->lhs_base_decl == t)
2298 /* If the constructor component is indirect, determine if we have a
2299 potential overlap with the lhs. The only bits of information we
2300 have to go on at this point are addressability and alias sets. */
2301 if (TREE_CODE (t) == INDIRECT_REF
2302 && (!data->lhs_base_decl || TREE_ADDRESSABLE (data->lhs_base_decl))
2303 && alias_sets_conflict_p (data->lhs_alias_set, get_alias_set (t)))
2306 if (IS_TYPE_OR_DECL_P (t))
2311 /* A subroutine of gimplify_init_constructor. Pre-evaluate *EXPR_P,
2312 force values that overlap with the lhs (as described by *DATA)
2313 into temporaries. */
2316 gimplify_init_ctor_preeval (tree *expr_p, tree *pre_p, tree *post_p,
2317 struct gimplify_init_ctor_preeval_data *data)
2319 enum gimplify_status one;
2321 /* If the value is invariant, then there's nothing to pre-evaluate.
2322 But ensure it doesn't have any side-effects since a SAVE_EXPR is
2323 invariant but has side effects and might contain a reference to
2324 the object we're initializing. */
2325 if (TREE_INVARIANT (*expr_p) && !TREE_SIDE_EFFECTS (*expr_p))
2328 /* If the type has non-trivial constructors, we can't pre-evaluate. */
2329 if (TREE_ADDRESSABLE (TREE_TYPE (*expr_p)))
2332 /* Recurse for nested constructors. */
2333 if (TREE_CODE (*expr_p) == CONSTRUCTOR)
2336 for (list = CONSTRUCTOR_ELTS (*expr_p); list ; list = TREE_CHAIN (list))
2337 gimplify_init_ctor_preeval (&TREE_VALUE (list), pre_p, post_p, data);
2341 /* We can't preevaluate if the type contains a placeholder. */
2342 if (type_contains_placeholder_p (TREE_TYPE (*expr_p)))
2345 /* Gimplify the constructor element to something appropriate for the rhs
2346 of a MODIFY_EXPR. Given that we know the lhs is an aggregate, we know
2347 the gimplifier will consider this a store to memory. Doing this
2348 gimplification now means that we won't have to deal with complicated
2349 language-specific trees, nor trees like SAVE_EXPR that can induce
2350 exponential search behavior. */
2351 one = gimplify_expr (expr_p, pre_p, post_p, is_gimple_mem_rhs, fb_rvalue);
2352 if (one == GS_ERROR)
2358 /* If we gimplified to a bare decl, we can be sure that it doesn't overlap
2359 with the lhs, since "a = { .x=a }" doesn't make sense. This will
2360 always be true for all scalars, since is_gimple_mem_rhs insists on a
2361 temporary variable for them. */
2362 if (DECL_P (*expr_p))
2365 /* If this is of variable size, we have no choice but to assume it doesn't
2366 overlap since we can't make a temporary for it. */
2367 if (!TREE_CONSTANT (TYPE_SIZE (TREE_TYPE (*expr_p))))
2370 /* Otherwise, we must search for overlap ... */
2371 if (!walk_tree (expr_p, gimplify_init_ctor_preeval_1, data, NULL))
2374 /* ... and if found, force the value into a temporary. */
2375 *expr_p = get_formal_tmp_var (*expr_p, pre_p);
2378 /* A subroutine of gimplify_init_ctor_eval. Create a loop for
2379 a RANGE_EXPR in a CONSTRUCTOR for an array.
2383 object[var] = value;
2390 We increment var _after_ the loop exit check because we might otherwise
2391 fail if upper == TYPE_MAX_VALUE (type for upper).
2393 Note that we never have to deal with SAVE_EXPRs here, because this has
2394 already been taken care of for us, in gimplify_init_ctor_preeval(). */
2396 static void gimplify_init_ctor_eval (tree, tree, tree *, bool);
2399 gimplify_init_ctor_eval_range (tree object, tree lower, tree upper,
2400 tree value, tree array_elt_type,
2401 tree *pre_p, bool cleared)
2403 tree loop_entry_label, loop_exit_label;
2404 tree var, var_type, cref;
2406 loop_entry_label = create_artificial_label ();
2407 loop_exit_label = create_artificial_label ();
2409 /* Create and initialize the index variable. */
2410 var_type = TREE_TYPE (upper);
2411 var = create_tmp_var (var_type, NULL);
2412 append_to_statement_list (build2 (MODIFY_EXPR, var_type, var, lower), pre_p);
2414 /* Add the loop entry label. */
2415 append_to_statement_list (build1 (LABEL_EXPR,
2420 /* Build the reference. */
2421 cref = build4 (ARRAY_REF, array_elt_type, unshare_expr (object),
2422 var, NULL_TREE, NULL_TREE);
2424 /* If we are a constructor, just call gimplify_init_ctor_eval to do
2425 the store. Otherwise just assign value to the reference. */
2427 if (TREE_CODE (value) == CONSTRUCTOR)
2428 /* NB we might have to call ourself recursively through
2429 gimplify_init_ctor_eval if the value is a constructor. */
2430 gimplify_init_ctor_eval (cref, CONSTRUCTOR_ELTS (value),
2433 append_to_statement_list (build2 (MODIFY_EXPR, TREE_TYPE (cref),
2437 /* We exit the loop when the index var is equal to the upper bound. */
2438 gimplify_and_add (build3 (COND_EXPR, void_type_node,
2439 build2 (EQ_EXPR, boolean_type_node,
2447 /* Otherwise, increment the index var... */
2448 append_to_statement_list (build2 (MODIFY_EXPR, var_type, var,
2449 build2 (PLUS_EXPR, var_type, var,
2450 fold_convert (var_type,
2451 integer_one_node))),
2454 /* ...and jump back to the loop entry. */
2455 append_to_statement_list (build1 (GOTO_EXPR,
2460 /* Add the loop exit label. */
2461 append_to_statement_list (build1 (LABEL_EXPR,
2467 /* A subroutine of gimplify_init_constructor. Generate individual
2468 MODIFY_EXPRs for a CONSTRUCTOR. OBJECT is the LHS against which the
2469 assignments should happen. LIST is the CONSTRUCTOR_ELTS of the
2470 CONSTRUCTOR. CLEARED is true if the entire LHS object has been
2474 gimplify_init_ctor_eval (tree object, tree list, tree *pre_p, bool cleared)
2476 tree array_elt_type = NULL;
2478 if (TREE_CODE (TREE_TYPE (object)) == ARRAY_TYPE)
2479 array_elt_type = TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (object)));
2481 for (; list; list = TREE_CHAIN (list))
2483 tree purpose, value, cref, init;
2485 purpose = TREE_PURPOSE (list);
2486 value = TREE_VALUE (list);
2488 /* NULL values are created above for gimplification errors. */
2492 if (cleared && initializer_zerop (value))
2495 /* ??? Here's to hoping the front end fills in all of the indices,
2496 so we don't have to figure out what's missing ourselves. */
2497 gcc_assert (purpose);
2499 /* If we have a RANGE_EXPR, we have to build a loop to assign the
2501 if (TREE_CODE (purpose) == RANGE_EXPR)
2503 tree lower = TREE_OPERAND (purpose, 0);
2504 tree upper = TREE_OPERAND (purpose, 1);
2506 /* If the lower bound is equal to upper, just treat it as if
2507 upper was the index. */
2508 if (simple_cst_equal (lower, upper))
2512 gimplify_init_ctor_eval_range (object, lower, upper, value,
2513 array_elt_type, pre_p, cleared);
2520 cref = build (ARRAY_REF, array_elt_type, unshare_expr (object),
2521 purpose, NULL_TREE, NULL_TREE);
2524 cref = build (COMPONENT_REF, TREE_TYPE (purpose),
2525 unshare_expr (object), purpose, NULL_TREE);
2527 if (TREE_CODE (value) == CONSTRUCTOR)
2528 gimplify_init_ctor_eval (cref, CONSTRUCTOR_ELTS (value),
2532 init = build (MODIFY_EXPR, TREE_TYPE (cref), cref, value);
2533 gimplify_and_add (init, pre_p);
2538 /* A subroutine of gimplify_modify_expr. Break out elements of a
2539 CONSTRUCTOR used as an initializer into separate MODIFY_EXPRs.
2541 Note that we still need to clear any elements that don't have explicit
2542 initializers, so if not all elements are initialized we keep the
2543 original MODIFY_EXPR, we just remove all of the constructor elements. */
2545 static enum gimplify_status
2546 gimplify_init_constructor (tree *expr_p, tree *pre_p,
2547 tree *post_p, bool want_value)
2550 tree ctor = TREE_OPERAND (*expr_p, 1);
2551 tree type = TREE_TYPE (ctor);
2552 enum gimplify_status ret;
2555 if (TREE_CODE (ctor) != CONSTRUCTOR)
2556 return GS_UNHANDLED;
2558 ret = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p, post_p,
2559 is_gimple_lvalue, fb_lvalue);
2560 if (ret == GS_ERROR)
2562 object = TREE_OPERAND (*expr_p, 0);
2564 elt_list = CONSTRUCTOR_ELTS (ctor);
2567 switch (TREE_CODE (type))
2571 case QUAL_UNION_TYPE:
2574 struct gimplify_init_ctor_preeval_data preeval_data;
2575 HOST_WIDE_INT num_type_elements, num_ctor_elements;
2576 HOST_WIDE_INT num_nonzero_elements, num_nonconstant_elements;
2579 /* Aggregate types must lower constructors to initialization of
2580 individual elements. The exception is that a CONSTRUCTOR node
2581 with no elements indicates zero-initialization of the whole. */
2582 if (elt_list == NULL)
2585 categorize_ctor_elements (ctor, &num_nonzero_elements,
2586 &num_nonconstant_elements,
2587 &num_ctor_elements);
2589 /* If a const aggregate variable is being initialized, then it
2590 should never be a lose to promote the variable to be static. */
2591 if (num_nonconstant_elements == 0
2592 && TREE_READONLY (object)
2593 && TREE_CODE (object) == VAR_DECL)
2595 DECL_INITIAL (object) = ctor;
2596 TREE_STATIC (object) = 1;
2597 if (!DECL_NAME (object))
2598 DECL_NAME (object) = create_tmp_var_name ("C");
2599 walk_tree (&DECL_INITIAL (object), force_labels_r, NULL, NULL);
2601 /* ??? C++ doesn't automatically append a .<number> to the
2602 assembler name, and even when it does, it looks a FE private
2603 data structures to figure out what that number should be,
2604 which are not set for this variable. I suppose this is
2605 important for local statics for inline functions, which aren't
2606 "local" in the object file sense. So in order to get a unique
2607 TU-local symbol, we must invoke the lhd version now. */
2608 lhd_set_decl_assembler_name (object);
2610 *expr_p = NULL_TREE;
2614 /* If there are "lots" of initialized elements, and all of them
2615 are valid address constants, then the entire initializer can
2616 be dropped to memory, and then memcpy'd out. */
2617 if (num_nonconstant_elements == 0)
2619 HOST_WIDE_INT size = int_size_in_bytes (type);
2622 /* ??? We can still get unbounded array types, at least
2623 from the C++ front end. This seems wrong, but attempt
2624 to work around it for now. */
2627 size = int_size_in_bytes (TREE_TYPE (object));
2629 TREE_TYPE (ctor) = type = TREE_TYPE (object);
2632 /* Find the maximum alignment we can assume for the object. */
2633 /* ??? Make use of DECL_OFFSET_ALIGN. */
2634 if (DECL_P (object))
2635 align = DECL_ALIGN (object);
2637 align = TYPE_ALIGN (type);
2639 if (size > 0 && !can_move_by_pieces (size, align))
2641 tree new = create_tmp_var_raw (type, "C");
2643 gimple_add_tmp_var (new);
2644 TREE_STATIC (new) = 1;
2645 TREE_READONLY (new) = 1;
2646 DECL_INITIAL (new) = ctor;
2647 if (align > DECL_ALIGN (new))
2649 DECL_ALIGN (new) = align;
2650 DECL_USER_ALIGN (new) = 1;
2652 walk_tree (&DECL_INITIAL (new), force_labels_r, NULL, NULL);
2654 TREE_OPERAND (*expr_p, 1) = new;
2656 /* This is no longer an assignment of a CONSTRUCTOR, but
2657 we still may have processing to do on the LHS. So
2658 pretend we didn't do anything here to let that happen. */
2659 return GS_UNHANDLED;
2663 /* If there are "lots" of initialized elements, even discounting
2664 those that are not address constants (and thus *must* be
2665 computed at runtime), then partition the constructor into
2666 constant and non-constant parts. Block copy the constant
2667 parts in, then generate code for the non-constant parts. */
2668 /* TODO. There's code in cp/typeck.c to do this. */
2670 num_type_elements = count_type_elements (TREE_TYPE (ctor));
2672 /* If there are "lots" of zeros, then block clear the object first. */
2674 if (num_type_elements - num_nonzero_elements > CLEAR_RATIO
2675 && num_nonzero_elements < num_type_elements/4)
2678 /* ??? This bit ought not be needed. For any element not present
2679 in the initializer, we should simply set them to zero. Except
2680 we'd need to *find* the elements that are not present, and that
2681 requires trickery to avoid quadratic compile-time behavior in
2682 large cases or excessive memory use in small cases. */
2683 else if (num_ctor_elements < num_type_elements)
2688 /* Zap the CONSTRUCTOR element list, which simplifies this case.
2689 Note that we still have to gimplify, in order to handle the
2690 case of variable sized types. Avoid shared tree structures. */
2691 CONSTRUCTOR_ELTS (ctor) = NULL_TREE;
2692 object = unshare_expr (object);
2693 gimplify_stmt (expr_p);
2694 append_to_statement_list (*expr_p, pre_p);
2697 /* If we have not block cleared the object, or if there are nonzero
2698 elements in the constructor, add assignments to the individual
2699 scalar fields of the object. */
2700 if (!cleared || num_nonzero_elements > 0)
2702 preeval_data.lhs_base_decl = get_base_address (object);
2703 if (!DECL_P (preeval_data.lhs_base_decl))
2704 preeval_data.lhs_base_decl = NULL;
2705 preeval_data.lhs_alias_set = get_alias_set (object);
2707 gimplify_init_ctor_preeval (&TREE_OPERAND (*expr_p, 1),
2708 pre_p, post_p, &preeval_data);
2709 gimplify_init_ctor_eval (object, elt_list, pre_p, cleared);
2712 *expr_p = NULL_TREE;
2720 /* Extract the real and imaginary parts out of the ctor. */
2724 r = TREE_VALUE (elt_list);
2725 elt_list = TREE_CHAIN (elt_list);
2728 i = TREE_VALUE (elt_list);
2729 gcc_assert (!TREE_CHAIN (elt_list));
2732 if (r == NULL || i == NULL)
2734 tree zero = convert (TREE_TYPE (type), integer_zero_node);
2741 /* Complex types have either COMPLEX_CST or COMPLEX_EXPR to
2742 represent creation of a complex value. */
2743 if (TREE_CONSTANT (r) && TREE_CONSTANT (i))
2745 ctor = build_complex (type, r, i);
2746 TREE_OPERAND (*expr_p, 1) = ctor;
2750 ctor = build (COMPLEX_EXPR, type, r, i);
2751 TREE_OPERAND (*expr_p, 1) = ctor;
2752 ret = gimplify_expr (&TREE_OPERAND (*expr_p, 1), pre_p, post_p,
2753 rhs_predicate_for (TREE_OPERAND (*expr_p, 0)),
2760 /* Go ahead and simplify constant constructors to VECTOR_CST. */
2761 if (TREE_CONSTANT (ctor))
2762 TREE_OPERAND (*expr_p, 1) = build_vector (type, elt_list);
2765 /* Vector types use CONSTRUCTOR all the way through gimple
2766 compilation as a general initializer. */
2767 for (; elt_list; elt_list = TREE_CHAIN (elt_list))
2769 enum gimplify_status tret;
2770 tret = gimplify_expr (&TREE_VALUE (elt_list), pre_p, post_p,
2771 is_gimple_val, fb_rvalue);
2772 if (tret == GS_ERROR)
2779 /* So how did we get a CONSTRUCTOR for a scalar type? */
2783 if (ret == GS_ERROR)
2785 else if (want_value)
2787 append_to_statement_list (*expr_p, pre_p);
2795 /* Subroutine of gimplify_modify_expr to do simplifications of MODIFY_EXPRs
2796 based on the code of the RHS. We loop for as long as something changes. */
2798 static enum gimplify_status
2799 gimplify_modify_expr_rhs (tree *expr_p, tree *from_p, tree *to_p, tree *pre_p,
2800 tree *post_p, bool want_value)
2802 enum gimplify_status ret = GS_OK;
2804 while (ret != GS_UNHANDLED)
2805 switch (TREE_CODE (*from_p))
2809 /* If we have code like
2813 where the type of "x" is a (possibly cv-qualified variant
2814 of "A"), treat the entire expression as identical to "x".
2815 This kind of code arises in C++ when an object is bound
2816 to a const reference, and if "x" is a TARGET_EXPR we want
2817 to take advantage of the optimization below. */
2820 pointer = TREE_OPERAND (*from_p, 0);
2821 STRIP_NOPS (pointer);
2822 if (TREE_CODE (pointer) == ADDR_EXPR
2823 && (lang_hooks.types_compatible_p
2824 (TREE_TYPE (TREE_OPERAND (pointer, 0)),
2825 TREE_TYPE (*from_p))))
2827 *from_p = TREE_OPERAND (pointer, 0);
2837 /* If we are initializing something from a TARGET_EXPR, strip the
2838 TARGET_EXPR and initialize it directly, if possible. This can't
2839 be done if the initializer is void, since that implies that the
2840 temporary is set in some non-trivial way.
2842 ??? What about code that pulls out the temp and uses it
2843 elsewhere? I think that such code never uses the TARGET_EXPR as
2844 an initializer. If I'm wrong, we'll abort because the temp won't
2845 have any RTL. In that case, I guess we'll need to replace
2846 references somehow. */
2847 tree init = TARGET_EXPR_INITIAL (*from_p);
2849 if (!VOID_TYPE_P (TREE_TYPE (init)))
2860 /* Remove any COMPOUND_EXPR in the RHS so the following cases will be
2862 gimplify_compound_expr (from_p, pre_p, true);
2867 /* If we're initializing from a CONSTRUCTOR, break this into
2868 individual MODIFY_EXPRs. */
2869 return gimplify_init_constructor (expr_p, pre_p, post_p, want_value);
2872 /* If we're assigning to a non-register type, push the assignment
2873 down into the branches. This is mandatory for ADDRESSABLE types,
2874 since we cannot generate temporaries for such, but it saves a
2875 copy in other cases as well. */
2876 if (!is_gimple_reg_type (TREE_TYPE (*from_p)))
2879 return gimplify_cond_expr (expr_p, pre_p, post_p, *to_p);
2893 /* Gimplify the MODIFY_EXPR node pointed by EXPR_P.
2899 PRE_P points to the list where side effects that must happen before
2900 *EXPR_P should be stored.
2902 POST_P points to the list where side effects that must happen after
2903 *EXPR_P should be stored.
2905 WANT_VALUE is nonzero iff we want to use the value of this expression
2906 in another expression. */
2908 static enum gimplify_status
2909 gimplify_modify_expr (tree *expr_p, tree *pre_p, tree *post_p, bool want_value)
2911 tree *from_p = &TREE_OPERAND (*expr_p, 1);
2912 tree *to_p = &TREE_OPERAND (*expr_p, 0);
2913 enum gimplify_status ret = GS_UNHANDLED;
2915 gcc_assert (TREE_CODE (*expr_p) == MODIFY_EXPR
2916 || TREE_CODE (*expr_p) == INIT_EXPR);
2918 /* The distinction between MODIFY_EXPR and INIT_EXPR is no longer useful. */
2919 if (TREE_CODE (*expr_p) == INIT_EXPR)
2920 TREE_SET_CODE (*expr_p, MODIFY_EXPR);
2922 /* See if any simplifications can be done based on what the RHS is. */
2923 ret = gimplify_modify_expr_rhs (expr_p, from_p, to_p, pre_p, post_p,
2925 if (ret != GS_UNHANDLED)
2928 /* If the value being copied is of variable width, compute the length
2929 of the copy into a WITH_SIZE_EXPR. Note that we need to do this
2930 before gimplifying any of the operands so that we can resolve any
2931 PLACEHOLDER_EXPRs in the size. Also note that the RTL expander uses
2932 the size of the expression to be copied, not of the destination, so
2933 that is what we must here. */
2934 maybe_with_size_expr (from_p);
2936 ret = gimplify_expr (to_p, pre_p, post_p, is_gimple_lvalue, fb_lvalue);
2937 if (ret == GS_ERROR)
2940 ret = gimplify_expr (from_p, pre_p, post_p,
2941 rhs_predicate_for (*to_p), fb_rvalue);
2942 if (ret == GS_ERROR)
2945 /* Now see if the above changed *from_p to something we handle specially. */
2946 ret = gimplify_modify_expr_rhs (expr_p, from_p, to_p, pre_p, post_p,
2948 if (ret != GS_UNHANDLED)
2951 /* If we've got a variable sized assignment between two lvalues (i.e. does
2952 not involve a call), then we can make things a bit more straightforward
2953 by converting the assignment to memcpy or memset. */
2954 if (TREE_CODE (*from_p) == WITH_SIZE_EXPR)
2956 tree from = TREE_OPERAND (*from_p, 0);
2957 tree size = TREE_OPERAND (*from_p, 1);
2959 if (TREE_CODE (from) == CONSTRUCTOR)
2960 return gimplify_modify_expr_to_memset (expr_p, size, want_value);
2961 if (is_gimple_addressable (from))
2964 return gimplify_modify_expr_to_memcpy (expr_p, size, want_value);
2968 if (gimplify_ctxp->into_ssa && is_gimple_reg (*to_p))
2970 /* If we've somehow already got an SSA_NAME on the LHS, then
2971 we're probably modifying it twice. Not good. */
2972 gcc_assert (TREE_CODE (*to_p) != SSA_NAME);
2973 *to_p = make_ssa_name (*to_p, *expr_p);
2978 append_to_statement_list (*expr_p, pre_p);
2986 /* Gimplify a comparison between two variable-sized objects. Do this
2987 with a call to BUILT_IN_MEMCMP. */
2989 static enum gimplify_status
2990 gimplify_variable_sized_compare (tree *expr_p)
2992 tree op0 = TREE_OPERAND (*expr_p, 0);
2993 tree op1 = TREE_OPERAND (*expr_p, 1);
2996 t = TYPE_SIZE_UNIT (TREE_TYPE (op0));
2997 t = unshare_expr (t);
2998 t = SUBSTITUTE_PLACEHOLDER_IN_EXPR (t, op0);
2999 args = tree_cons (NULL, t, NULL);
3000 t = build_fold_addr_expr (op1);
3001 args = tree_cons (NULL, t, args);
3002 dest = build_fold_addr_expr (op0);
3003 args = tree_cons (NULL, dest, args);
3004 t = implicit_built_in_decls[BUILT_IN_MEMCMP];
3005 t = build_function_call_expr (t, args);
3007 = build (TREE_CODE (*expr_p), TREE_TYPE (*expr_p), t, integer_zero_node);
3012 /* Gimplify TRUTH_ANDIF_EXPR and TRUTH_ORIF_EXPR expressions. EXPR_P
3013 points to the expression to gimplify.
3015 Expressions of the form 'a && b' are gimplified to:
3017 a && b ? true : false
3019 gimplify_cond_expr will do the rest.
3021 PRE_P points to the list where side effects that must happen before
3022 *EXPR_P should be stored. */
3024 static enum gimplify_status
3025 gimplify_boolean_expr (tree *expr_p)
3027 /* Preserve the original type of the expression. */
3028 tree type = TREE_TYPE (*expr_p);
3030 *expr_p = build (COND_EXPR, type, *expr_p,
3031 convert (type, boolean_true_node),
3032 convert (type, boolean_false_node));
3037 /* Gimplifies an expression sequence. This function gimplifies each
3038 expression and re-writes the original expression with the last
3039 expression of the sequence in GIMPLE form.
3041 PRE_P points to the list where the side effects for all the
3042 expressions in the sequence will be emitted.
3044 WANT_VALUE is true when the result of the last COMPOUND_EXPR is used. */
3045 /* ??? Should rearrange to share the pre-queue with all the indirect
3046 invocations of gimplify_expr. Would probably save on creations
3047 of statement_list nodes. */
3049 static enum gimplify_status
3050 gimplify_compound_expr (tree *expr_p, tree *pre_p, bool want_value)
3056 tree *sub_p = &TREE_OPERAND (t, 0);
3058 if (TREE_CODE (*sub_p) == COMPOUND_EXPR)
3059 gimplify_compound_expr (sub_p, pre_p, false);
3061 gimplify_stmt (sub_p);
3062 append_to_statement_list (*sub_p, pre_p);
3064 t = TREE_OPERAND (t, 1);
3066 while (TREE_CODE (t) == COMPOUND_EXPR);
3073 gimplify_stmt (expr_p);
3078 /* Gimplifies a statement list. These may be created either by an
3079 enlightened front-end, or by shortcut_cond_expr. */
3081 static enum gimplify_status
3082 gimplify_statement_list (tree *expr_p)
3084 tree_stmt_iterator i = tsi_start (*expr_p);
3086 while (!tsi_end_p (i))
3090 gimplify_stmt (tsi_stmt_ptr (i));
3095 else if (TREE_CODE (t) == STATEMENT_LIST)
3097 tsi_link_before (&i, t, TSI_SAME_STMT);
3107 /* Gimplify a SAVE_EXPR node. EXPR_P points to the expression to
3108 gimplify. After gimplification, EXPR_P will point to a new temporary
3109 that holds the original value of the SAVE_EXPR node.
3111 PRE_P points to the list where side effects that must happen before
3112 *EXPR_P should be stored. */
3114 static enum gimplify_status
3115 gimplify_save_expr (tree *expr_p, tree *pre_p, tree *post_p)
3117 enum gimplify_status ret = GS_ALL_DONE;
3120 gcc_assert (TREE_CODE (*expr_p) == SAVE_EXPR);
3121 val = TREE_OPERAND (*expr_p, 0);
3123 /* If the SAVE_EXPR has not been resolved, then evaluate it once. */
3124 if (!SAVE_EXPR_RESOLVED_P (*expr_p))
3126 /* The operand may be a void-valued expression such as SAVE_EXPRs
3127 generated by the Java frontend for class initialization. It is
3128 being executed only for its side-effects. */
3129 if (TREE_TYPE (val) == void_type_node)
3131 ret = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p, post_p,
3132 is_gimple_stmt, fb_none);
3133 append_to_statement_list (TREE_OPERAND (*expr_p, 0), pre_p);
3137 val = get_initialized_tmp_var (val, pre_p, post_p);
3139 TREE_OPERAND (*expr_p, 0) = val;
3140 SAVE_EXPR_RESOLVED_P (*expr_p) = 1;
3148 /* Re-write the ADDR_EXPR node pointed by EXPR_P
3155 PRE_P points to the list where side effects that must happen before
3156 *EXPR_P should be stored.
3158 POST_P points to the list where side effects that must happen after
3159 *EXPR_P should be stored. */
3161 static enum gimplify_status
3162 gimplify_addr_expr (tree *expr_p, tree *pre_p, tree *post_p)
3164 tree expr = *expr_p;
3165 tree op0 = TREE_OPERAND (expr, 0);
3166 enum gimplify_status ret;
3168 switch (TREE_CODE (op0))
3171 case MISALIGNED_INDIRECT_REF:
3173 /* Check if we are dealing with an expression of the form '&*ptr'.
3174 While the front end folds away '&*ptr' into 'ptr', these
3175 expressions may be generated internally by the compiler (e.g.,
3176 builtins like __builtin_va_end). */
3177 /* Caution: the silent array decomposition semantics we allow for
3178 ADDR_EXPR means we can't always discard the pair. */
3180 tree op00 = TREE_OPERAND (op0, 0);
3181 tree t_expr = TREE_TYPE (expr);
3182 tree t_op00 = TREE_TYPE (op00);
3184 if (!lang_hooks.types_compatible_p (t_expr, t_op00))
3186 #ifdef ENABLE_CHECKING
3187 tree t_op0 = TREE_TYPE (op0);
3188 gcc_assert (TREE_CODE (t_op0) == ARRAY_TYPE
3189 && POINTER_TYPE_P (t_expr)
3190 && cpt_same_type (TREE_TYPE (t_op0),
3192 && POINTER_TYPE_P (t_op00)
3193 && cpt_same_type (t_op0, TREE_TYPE (t_op00)));
3195 op00 = fold_convert (TREE_TYPE (expr), op00);
3202 case VIEW_CONVERT_EXPR:
3203 /* Take the address of our operand and then convert it to the type of
3206 ??? The interactions of VIEW_CONVERT_EXPR and aliasing is not at
3207 all clear. The impact of this transformation is even less clear. */
3209 /* If the operand is a useless conversion, look through it. Doing so
3210 guarantees that the ADDR_EXPR and its operand will remain of the
3212 if (tree_ssa_useless_type_conversion (TREE_OPERAND (op0, 0)))
3213 op0 = TREE_OPERAND (op0, 0);
3215 *expr_p = fold_convert (TREE_TYPE (expr),
3216 build_fold_addr_expr (TREE_OPERAND (op0, 0)));
3221 /* We use fb_either here because the C frontend sometimes takes
3222 the address of a call that returns a struct; see
3223 gcc.dg/c99-array-lval-1.c. The gimplifier will correctly make
3224 the implied temporary explicit. */
3225 ret = gimplify_expr (&TREE_OPERAND (expr, 0), pre_p, post_p,
3226 is_gimple_addressable, fb_either);
3227 if (ret != GS_ERROR)
3229 op0 = TREE_OPERAND (expr, 0);
3231 /* For various reasons, the gimplification of the expression
3232 may have made a new INDIRECT_REF. */
3233 if (TREE_CODE (op0) == INDIRECT_REF)
3234 goto do_indirect_ref;
3236 /* Make sure TREE_INVARIANT, TREE_CONSTANT, and TREE_SIDE_EFFECTS
3238 recompute_tree_invarant_for_addr_expr (expr);
3240 /* Mark the RHS addressable. */
3241 lang_hooks.mark_addressable (TREE_OPERAND (expr, 0));
3249 /* Gimplify the operands of an ASM_EXPR. Input operands should be a gimple
3250 value; output operands should be a gimple lvalue. */
3252 static enum gimplify_status
3253 gimplify_asm_expr (tree *expr_p, tree *pre_p, tree *post_p)
3255 tree expr = *expr_p;
3256 int noutputs = list_length (ASM_OUTPUTS (expr));
3257 const char **oconstraints
3258 = (const char **) alloca ((noutputs) * sizeof (const char *));
3261 const char *constraint;
3262 bool allows_mem, allows_reg, is_inout;
3263 enum gimplify_status ret, tret;
3266 for (i = 0, link = ASM_OUTPUTS (expr); link; ++i, link = TREE_CHAIN (link))
3268 size_t constraint_len;
3269 oconstraints[i] = constraint
3270 = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (link)));
3271 constraint_len = strlen (constraint);
3272 if (constraint_len == 0)
3275 parse_output_constraint (&constraint, i, 0, 0,
3276 &allows_mem, &allows_reg, &is_inout);
3278 if (!allows_reg && allows_mem)
3279 lang_hooks.mark_addressable (TREE_VALUE (link));
3281 tret = gimplify_expr (&TREE_VALUE (link), pre_p, post_p,
3282 is_inout ? is_gimple_min_lval : is_gimple_lvalue,
3283 fb_lvalue | fb_mayfail);
3284 if (tret == GS_ERROR)
3286 error ("invalid lvalue in asm output %d", i);
3292 /* An input/output operand. To give the optimizers more
3293 flexibility, split it into separate input and output
3298 /* Turn the in/out constraint into an output constraint. */
3299 char *p = xstrdup (constraint);
3301 TREE_VALUE (TREE_PURPOSE (link)) = build_string (constraint_len, p);
3304 /* And add a matching input constraint. */
3307 sprintf (buf, "%d", i);
3308 input = build_string (strlen (buf), buf);
3311 input = build_string (constraint_len - 1, constraint + 1);
3312 input = build_tree_list (build_tree_list (NULL_TREE, input),
3313 unshare_expr (TREE_VALUE (link)));
3314 ASM_INPUTS (expr) = chainon (ASM_INPUTS (expr), input);
3318 for (link = ASM_INPUTS (expr); link; ++i, link = TREE_CHAIN (link))
3321 = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (link)));
3322 parse_input_constraint (&constraint, 0, 0, noutputs, 0,
3323 oconstraints, &allows_mem, &allows_reg);
3325 /* If the operand is a memory input, it should be an lvalue. */
3326 if (!allows_reg && allows_mem)
3328 lang_hooks.mark_addressable (TREE_VALUE (link));
3329 tret = gimplify_expr (&TREE_VALUE (link), pre_p, post_p,
3330 is_gimple_lvalue, fb_lvalue | fb_mayfail);
3331 if (tret == GS_ERROR)
3333 error ("memory input %d is not directly addressable", i);
3339 tret = gimplify_expr (&TREE_VALUE (link), pre_p, post_p,
3340 is_gimple_asm_val, fb_rvalue);
3341 if (tret == GS_ERROR)
3349 /* Gimplify a CLEANUP_POINT_EXPR. Currently this works by adding
3350 WITH_CLEANUP_EXPRs to the prequeue as we encounter cleanups while
3351 gimplifying the body, and converting them to TRY_FINALLY_EXPRs when we
3352 return to this function.
3354 FIXME should we complexify the prequeue handling instead? Or use flags
3355 for all the cleanups and let the optimizer tighten them up? The current
3356 code seems pretty fragile; it will break on a cleanup within any
3357 non-conditional nesting. But any such nesting would be broken, anyway;
3358 we can't write a TRY_FINALLY_EXPR that starts inside a nesting construct
3359 and continues out of it. We can do that at the RTL level, though, so
3360 having an optimizer to tighten up try/finally regions would be a Good
3363 static enum gimplify_status
3364 gimplify_cleanup_point_expr (tree *expr_p, tree *pre_p)
3366 tree_stmt_iterator iter;
3369 tree temp = voidify_wrapper_expr (*expr_p, NULL);
3371 /* We only care about the number of conditions between the innermost
3372 CLEANUP_POINT_EXPR and the cleanup. So save and reset the count. */
3373 int old_conds = gimplify_ctxp->conditions;
3374 gimplify_ctxp->conditions = 0;
3376 body = TREE_OPERAND (*expr_p, 0);
3377 gimplify_to_stmt_list (&body);
3379 gimplify_ctxp->conditions = old_conds;
3381 for (iter = tsi_start (body); !tsi_end_p (iter); )
3383 tree *wce_p = tsi_stmt_ptr (iter);
3386 if (TREE_CODE (wce) == WITH_CLEANUP_EXPR)
3388 if (tsi_one_before_end_p (iter))
3390 tsi_link_before (&iter, TREE_OPERAND (wce, 0), TSI_SAME_STMT);
3397 enum tree_code code;
3399 if (CLEANUP_EH_ONLY (wce))
3400 code = TRY_CATCH_EXPR;
3402 code = TRY_FINALLY_EXPR;
3404 sl = tsi_split_statement_list_after (&iter);
3405 tfe = build (code, void_type_node, sl, NULL_TREE);
3406 append_to_statement_list (TREE_OPERAND (wce, 0),
3407 &TREE_OPERAND (tfe, 1));
3409 iter = tsi_start (sl);
3419 append_to_statement_list (body, pre_p);
3429 /* Insert a cleanup marker for gimplify_cleanup_point_expr. CLEANUP
3430 is the cleanup action required. */
3433 gimple_push_cleanup (tree var, tree cleanup, bool eh_only, tree *pre_p)
3437 /* Errors can result in improperly nested cleanups. Which results in
3438 confusion when trying to resolve the WITH_CLEANUP_EXPR. */
3439 if (errorcount || sorrycount)
3442 if (gimple_conditional_context ())
3444 /* If we're in a conditional context, this is more complex. We only
3445 want to run the cleanup if we actually ran the initialization that
3446 necessitates it, but we want to run it after the end of the
3447 conditional context. So we wrap the try/finally around the
3448 condition and use a flag to determine whether or not to actually
3449 run the destructor. Thus
3453 becomes (approximately)
3457 if (test) { A::A(temp); flag = 1; val = f(temp); }
3460 if (flag) A::~A(temp);
3465 tree flag = create_tmp_var (boolean_type_node, "cleanup");
3466 tree ffalse = build (MODIFY_EXPR, void_type_node, flag,
3467 boolean_false_node);
3468 tree ftrue = build (MODIFY_EXPR, void_type_node, flag,
3470 cleanup = build (COND_EXPR, void_type_node, flag, cleanup, NULL);
3471 wce = build (WITH_CLEANUP_EXPR, void_type_node, cleanup);
3472 append_to_statement_list (ffalse, &gimplify_ctxp->conditional_cleanups);
3473 append_to_statement_list (wce, &gimplify_ctxp->conditional_cleanups);
3474 append_to_statement_list (ftrue, pre_p);
3476 /* Because of this manipulation, and the EH edges that jump
3477 threading cannot redirect, the temporary (VAR) will appear
3478 to be used uninitialized. Don't warn. */
3479 TREE_NO_WARNING (var) = 1;
3483 wce = build (WITH_CLEANUP_EXPR, void_type_node, cleanup);
3484 CLEANUP_EH_ONLY (wce) = eh_only;
3485 append_to_statement_list (wce, pre_p);
3488 gimplify_stmt (&TREE_OPERAND (wce, 0));
3491 /* Gimplify a TARGET_EXPR which doesn't appear on the rhs of an INIT_EXPR. */
3493 static enum gimplify_status
3494 gimplify_target_expr (tree *expr_p, tree *pre_p, tree *post_p)
3496 tree targ = *expr_p;
3497 tree temp = TARGET_EXPR_SLOT (targ);
3498 tree init = TARGET_EXPR_INITIAL (targ);
3499 enum gimplify_status ret;
3503 /* TARGET_EXPR temps aren't part of the enclosing block, so add it
3504 to the temps list. */
3505 gimple_add_tmp_var (temp);
3507 /* If TARGET_EXPR_INITIAL is void, then the mere evaluation of the
3508 expression is supposed to initialize the slot. */
3509 if (VOID_TYPE_P (TREE_TYPE (init)))
3510 ret = gimplify_expr (&init, pre_p, post_p, is_gimple_stmt, fb_none);
3513 /* Special handling for BIND_EXPR can result in fewer temps. */
3515 if (TREE_CODE (init) == BIND_EXPR)
3516 gimplify_bind_expr (&init, temp, pre_p);
3519 init = build (MODIFY_EXPR, void_type_node, temp, init);
3520 ret = gimplify_expr (&init, pre_p, post_p, is_gimple_stmt,
3524 if (ret == GS_ERROR)
3526 append_to_statement_list (init, pre_p);
3528 /* If needed, push the cleanup for the temp. */
3529 if (TARGET_EXPR_CLEANUP (targ))
3531 gimplify_stmt (&TARGET_EXPR_CLEANUP (targ));
3532 gimple_push_cleanup (temp, TARGET_EXPR_CLEANUP (targ),
3533 CLEANUP_EH_ONLY (targ), pre_p);
3536 /* Only expand this once. */
3537 TREE_OPERAND (targ, 3) = init;
3538 TARGET_EXPR_INITIAL (targ) = NULL_TREE;
3541 /* We should have expanded this before. */
3542 gcc_assert (DECL_SEEN_IN_BIND_EXPR_P (temp));
3548 /* Gimplification of expression trees. */
3550 /* Gimplify an expression which appears at statement context; usually, this
3551 means replacing it with a suitably gimple STATEMENT_LIST. */
3554 gimplify_stmt (tree *stmt_p)
3556 gimplify_expr (stmt_p, NULL, NULL, is_gimple_stmt, fb_none);
3559 /* Similarly, but force the result to be a STATEMENT_LIST. */
3562 gimplify_to_stmt_list (tree *stmt_p)
3564 gimplify_stmt (stmt_p);
3566 *stmt_p = alloc_stmt_list ();
3567 else if (TREE_CODE (*stmt_p) != STATEMENT_LIST)
3570 *stmt_p = alloc_stmt_list ();
3571 append_to_statement_list (t, stmt_p);
3576 /* Gimplifies the expression tree pointed by EXPR_P. Return 0 if
3577 gimplification failed.
3579 PRE_P points to the list where side effects that must happen before
3580 EXPR should be stored.
3582 POST_P points to the list where side effects that must happen after
3583 EXPR should be stored, or NULL if there is no suitable list. In
3584 that case, we copy the result to a temporary, emit the
3585 post-effects, and then return the temporary.
3587 GIMPLE_TEST_F points to a function that takes a tree T and
3588 returns nonzero if T is in the GIMPLE form requested by the
3589 caller. The GIMPLE predicates are in tree-gimple.c.
3591 This test is used twice. Before gimplification, the test is
3592 invoked to determine whether *EXPR_P is already gimple enough. If
3593 that fails, *EXPR_P is gimplified according to its code and
3594 GIMPLE_TEST_F is called again. If the test still fails, then a new
3595 temporary variable is created and assigned the value of the
3596 gimplified expression.
3598 FALLBACK tells the function what sort of a temporary we want. If the 1
3599 bit is set, an rvalue is OK. If the 2 bit is set, an lvalue is OK.
3600 If both are set, either is OK, but an lvalue is preferable.
3602 The return value is either GS_ERROR or GS_ALL_DONE, since this function
3603 iterates until solution. */
3605 enum gimplify_status
3606 gimplify_expr (tree *expr_p, tree *pre_p, tree *post_p,
3607 bool (* gimple_test_f) (tree), fallback_t fallback)
3610 tree internal_pre = NULL_TREE;
3611 tree internal_post = NULL_TREE;
3613 int is_statement = (pre_p == NULL);
3614 location_t saved_location;
3615 enum gimplify_status ret;
3617 save_expr = *expr_p;
3618 if (save_expr == NULL_TREE)
3621 /* We used to check the predicate here and return immediately if it
3622 succeeds. This is wrong; the design is for gimplification to be
3623 idempotent, and for the predicates to only test for valid forms, not
3624 whether they are fully simplified. */
3626 /* Set up our internal queues if needed. */
3628 pre_p = &internal_pre;
3630 post_p = &internal_post;
3632 saved_location = input_location;
3633 if (save_expr != error_mark_node
3634 && EXPR_HAS_LOCATION (*expr_p))
3635 input_location = EXPR_LOCATION (*expr_p);
3637 /* Loop over the specific gimplifiers until the toplevel node
3638 remains the same. */
3641 /* Strip away as many useless type conversions as possible
3643 STRIP_USELESS_TYPE_CONVERSION (*expr_p);
3645 /* Remember the expr. */
3646 save_expr = *expr_p;
3648 /* Die, die, die, my darling. */
3649 if (save_expr == error_mark_node
3650 || (TREE_TYPE (save_expr)
3651 && TREE_TYPE (save_expr) == error_mark_node))
3657 /* Do any language-specific gimplification. */
3658 ret = lang_hooks.gimplify_expr (expr_p, pre_p, post_p);
3661 if (*expr_p == NULL_TREE)
3663 if (*expr_p != save_expr)
3666 else if (ret != GS_UNHANDLED)
3670 switch (TREE_CODE (*expr_p))
3672 /* First deal with the special cases. */
3674 case POSTINCREMENT_EXPR:
3675 case POSTDECREMENT_EXPR:
3676 case PREINCREMENT_EXPR:
3677 case PREDECREMENT_EXPR:
3678 ret = gimplify_self_mod_expr (expr_p, pre_p, post_p,
3679 fallback != fb_none);
3683 case ARRAY_RANGE_REF:
3687 case VIEW_CONVERT_EXPR:
3688 ret = gimplify_compound_lval (expr_p, pre_p, post_p,
3689 fallback ? fallback : fb_rvalue);
3693 ret = gimplify_cond_expr (expr_p, pre_p, post_p, NULL_TREE);
3697 ret = gimplify_call_expr (expr_p, pre_p, fallback != fb_none);
3704 ret = gimplify_compound_expr (expr_p, pre_p, fallback != fb_none);
3709 ret = gimplify_modify_expr (expr_p, pre_p, post_p,
3710 fallback != fb_none);
3713 case TRUTH_ANDIF_EXPR:
3714 case TRUTH_ORIF_EXPR:
3715 ret = gimplify_boolean_expr (expr_p);
3718 case TRUTH_NOT_EXPR:
3719 TREE_OPERAND (*expr_p, 0)
3720 = gimple_boolify (TREE_OPERAND (*expr_p, 0));
3721 ret = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p, post_p,
3722 is_gimple_val, fb_rvalue);
3723 recalculate_side_effects (*expr_p);
3727 ret = gimplify_addr_expr (expr_p, pre_p, post_p);
3731 ret = gimplify_va_arg_expr (expr_p, pre_p, post_p);
3736 if (IS_EMPTY_STMT (*expr_p))
3742 if (VOID_TYPE_P (TREE_TYPE (*expr_p))
3743 || fallback == fb_none)
3745 /* Just strip a conversion to void (or in void context) and
3747 *expr_p = TREE_OPERAND (*expr_p, 0);
3751 ret = gimplify_conversion (expr_p);
3752 if (ret == GS_ERROR)
3754 if (*expr_p != save_expr)
3758 case FIX_TRUNC_EXPR:
3760 case FIX_FLOOR_EXPR:
3761 case FIX_ROUND_EXPR:
3762 /* unary_expr: ... | '(' cast ')' val | ... */
3763 ret = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p, post_p,
3764 is_gimple_val, fb_rvalue);
3765 recalculate_side_effects (*expr_p);
3768 case ALIGN_INDIRECT_REF:
3769 case MISALIGNED_INDIRECT_REF:
3771 ret = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p, post_p,
3772 is_gimple_reg, fb_rvalue);
3773 recalculate_side_effects (*expr_p);
3776 /* Constants need not be gimplified. */
3786 /* If we require an lvalue, such as for ADDR_EXPR, retain the
3787 CONST_DECL node. Otherwise the decl is replaceable by its
3789 /* ??? Should be == fb_lvalue, but ADDR_EXPR passes fb_either. */
3790 if (fallback & fb_lvalue)
3793 *expr_p = DECL_INITIAL (*expr_p);
3797 ret = gimplify_decl_expr (expr_p);
3801 /* FIXME make this a decl. */
3806 ret = gimplify_bind_expr (expr_p, NULL, pre_p);
3810 ret = gimplify_loop_expr (expr_p, pre_p);
3814 ret = gimplify_switch_expr (expr_p, pre_p);
3818 ret = gimplify_exit_expr (expr_p);
3822 /* If the target is not LABEL, then it is a computed jump
3823 and the target needs to be gimplified. */
3824 if (TREE_CODE (GOTO_DESTINATION (*expr_p)) != LABEL_DECL)
3825 ret = gimplify_expr (&GOTO_DESTINATION (*expr_p), pre_p,
3826 NULL, is_gimple_val, fb_rvalue);
3831 gcc_assert (decl_function_context (LABEL_EXPR_LABEL (*expr_p))
3832 == current_function_decl);
3835 case CASE_LABEL_EXPR:
3836 ret = gimplify_case_label_expr (expr_p);
3840 ret = gimplify_return_expr (*expr_p, pre_p);
3844 /* Don't reduce this in place; let gimplify_init_constructor work its
3845 magic. Buf if we're just elaborating this for side effects, just
3846 gimplify any element that has side-effects. */
3847 if (fallback == fb_none)
3849 for (tmp = CONSTRUCTOR_ELTS (*expr_p); tmp;
3850 tmp = TREE_CHAIN (tmp))
3851 if (TREE_SIDE_EFFECTS (TREE_VALUE (tmp)))
3852 gimplify_expr (&TREE_VALUE (tmp), pre_p, post_p,
3853 gimple_test_f, fallback);
3855 *expr_p = NULL_TREE;
3861 /* The following are special cases that are not handled by the
3862 original GIMPLE grammar. */
3864 /* SAVE_EXPR nodes are converted into a GIMPLE identifier and
3867 ret = gimplify_save_expr (expr_p, pre_p, post_p);
3872 enum gimplify_status r0, r1, r2;
3874 r0 = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p, post_p,
3875 is_gimple_lvalue, fb_either);
3876 r1 = gimplify_expr (&TREE_OPERAND (*expr_p, 1), pre_p, post_p,
3877 is_gimple_val, fb_rvalue);
3878 r2 = gimplify_expr (&TREE_OPERAND (*expr_p, 2), pre_p, post_p,
3879 is_gimple_val, fb_rvalue);
3880 recalculate_side_effects (*expr_p);
3882 ret = MIN (r0, MIN (r1, r2));
3886 case NON_LVALUE_EXPR:
3887 /* This should have been stripped above. */
3891 ret = gimplify_asm_expr (expr_p, pre_p, post_p);
3894 case TRY_FINALLY_EXPR:
3895 case TRY_CATCH_EXPR:
3896 gimplify_to_stmt_list (&TREE_OPERAND (*expr_p, 0));
3897 gimplify_to_stmt_list (&TREE_OPERAND (*expr_p, 1));
3901 case CLEANUP_POINT_EXPR:
3902 ret = gimplify_cleanup_point_expr (expr_p, pre_p);
3906 ret = gimplify_target_expr (expr_p, pre_p, post_p);
3910 gimplify_to_stmt_list (&CATCH_BODY (*expr_p));
3914 case EH_FILTER_EXPR:
3915 gimplify_to_stmt_list (&EH_FILTER_FAILURE (*expr_p));
3921 enum gimplify_status r0, r1;
3922 r0 = gimplify_expr (&OBJ_TYPE_REF_OBJECT (*expr_p), pre_p, post_p,
3923 is_gimple_val, fb_rvalue);
3924 r1 = gimplify_expr (&OBJ_TYPE_REF_EXPR (*expr_p), pre_p, post_p,
3925 is_gimple_val, fb_rvalue);
3931 /* We get here when taking the address of a label. We mark
3932 the label as "forced"; meaning it can never be removed and
3933 it is a potential target for any computed goto. */
3934 FORCED_LABEL (*expr_p) = 1;
3938 case STATEMENT_LIST:
3939 ret = gimplify_statement_list (expr_p);
3942 case WITH_SIZE_EXPR:
3944 enum gimplify_status r0, r1;
3945 r0 = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p,
3946 post_p == &internal_post ? NULL : post_p,
3947 gimple_test_f, fallback);
3948 r1 = gimplify_expr (&TREE_OPERAND (*expr_p, 1), pre_p, post_p,
3949 is_gimple_val, fb_rvalue);
3954 /* ??? If this is a local variable, and it has not been seen in any
3955 outer BIND_EXPR, then it's probably the result of a duplicate
3956 declaration, for which we've already issued an error. It would
3957 be really nice if the front end wouldn't leak these at all.
3958 Currently the only known culprit is C++ destructors, as seen
3959 in g++.old-deja/g++.jason/binding.C. */
3961 if (!TREE_STATIC (tmp) && !DECL_EXTERNAL (tmp)
3962 && decl_function_context (tmp) == current_function_decl
3963 && !DECL_SEEN_IN_BIND_EXPR_P (tmp))
3965 gcc_assert (errorcount || sorrycount);
3974 /* If this is a local variable sized decl, it must be accessed
3975 indirectly. Perform that substitution. */
3976 if (DECL_VALUE_EXPR (tmp))
3978 *expr_p = unshare_expr (DECL_VALUE_EXPR (tmp));
3987 /* Allow callbacks into the gimplifier during optimization. */
3992 switch (TREE_CODE_CLASS (TREE_CODE (*expr_p)))
3994 case tcc_comparison:
3995 /* If this is a comparison of objects of aggregate type,
3996 handle it specially (by converting to a call to
3997 memcmp). It would be nice to only have to do this
3998 for variable-sized objects, but then we'd have to
3999 allow the same nest of reference nodes we allow for
4000 MODIFY_EXPR and that's too complex. */
4001 if (!AGGREGATE_TYPE_P (TREE_TYPE (TREE_OPERAND (*expr_p, 1))))
4003 ret = gimplify_variable_sized_compare (expr_p);
4006 /* If *EXPR_P does not need to be special-cased, handle it
4007 according to its class. */
4009 ret = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p,
4010 post_p, is_gimple_val, fb_rvalue);
4016 enum gimplify_status r0, r1;
4018 r0 = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p,
4019 post_p, is_gimple_val, fb_rvalue);
4020 r1 = gimplify_expr (&TREE_OPERAND (*expr_p, 1), pre_p,
4021 post_p, is_gimple_val, fb_rvalue);
4027 case tcc_declaration:
4030 goto dont_recalculate;
4033 gcc_assert (TREE_CODE (*expr_p) == TRUTH_AND_EXPR
4034 || TREE_CODE (*expr_p) == TRUTH_OR_EXPR
4035 || TREE_CODE (*expr_p) == TRUTH_XOR_EXPR);
4039 recalculate_side_effects (*expr_p);
4044 /* If we replaced *expr_p, gimplify again. */
4045 if (ret == GS_OK && (*expr_p == NULL || *expr_p == save_expr))
4048 while (ret == GS_OK);
4050 /* If we encountered an error_mark somewhere nested inside, either
4051 stub out the statement or propagate the error back out. */
4052 if (ret == GS_ERROR)
4059 /* This was only valid as a return value from the langhook, which
4060 we handled. Make sure it doesn't escape from any other context. */
4061 gcc_assert (ret != GS_UNHANDLED);
4063 if (fallback == fb_none && *expr_p && !is_gimple_stmt (*expr_p))
4065 /* We aren't looking for a value, and we don't have a valid
4066 statement. If it doesn't have side-effects, throw it away. */
4067 if (!TREE_SIDE_EFFECTS (*expr_p))
4069 else if (!TREE_THIS_VOLATILE (*expr_p))
4071 /* This is probably a _REF that contains something nested that
4072 has side effects. Recurse through the operands to find it. */
4073 enum tree_code code = TREE_CODE (*expr_p);
4078 case REALPART_EXPR: case IMAGPART_EXPR:
4079 gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p, post_p,
4080 gimple_test_f, fallback);
4083 case ARRAY_REF: case ARRAY_RANGE_REF:
4084 gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p, post_p,
4085 gimple_test_f, fallback);
4086 gimplify_expr (&TREE_OPERAND (*expr_p, 1), pre_p, post_p,
4087 gimple_test_f, fallback);
4091 /* Anything else with side-effects must be converted to
4092 a valid statement before we get here. */
4098 else if (COMPLETE_TYPE_P (TREE_TYPE (*expr_p)))
4100 /* Historically, the compiler has treated a bare
4101 reference to a volatile lvalue as forcing a load. */
4102 tree tmp = create_tmp_var (TREE_TYPE (*expr_p), "vol");
4103 *expr_p = build (MODIFY_EXPR, TREE_TYPE (tmp), tmp, *expr_p);
4106 /* We can't do anything useful with a volatile reference to
4107 incomplete type, so just throw it away. */
4111 /* If we are gimplifying at the statement level, we're done. Tack
4112 everything together and replace the original statement with the
4114 if (fallback == fb_none || is_statement)
4116 if (internal_pre || internal_post)
4118 append_to_statement_list (*expr_p, &internal_pre);
4119 append_to_statement_list (internal_post, &internal_pre);
4120 annotate_all_with_locus (&internal_pre, input_location);
4121 *expr_p = internal_pre;
4125 else if (TREE_CODE (*expr_p) == STATEMENT_LIST)
4126 annotate_all_with_locus (expr_p, input_location);
4128 annotate_one_with_locus (*expr_p, input_location);
4132 /* Otherwise we're gimplifying a subexpression, so the resulting value is
4135 /* If it's sufficiently simple already, we're done. Unless we are
4136 handling some post-effects internally; if that's the case, we need to
4137 copy into a temp before adding the post-effects to the tree. */
4138 if (!internal_post && (*gimple_test_f) (*expr_p))
4141 /* Otherwise, we need to create a new temporary for the gimplified
4144 /* We can't return an lvalue if we have an internal postqueue. The
4145 object the lvalue refers to would (probably) be modified by the
4146 postqueue; we need to copy the value out first, which means an
4148 if ((fallback & fb_lvalue) && !internal_post
4149 && is_gimple_addressable (*expr_p))
4151 /* An lvalue will do. Take the address of the expression, store it
4152 in a temporary, and replace the expression with an INDIRECT_REF of
4154 tmp = build_fold_addr_expr (*expr_p);
4155 gimplify_expr (&tmp, pre_p, post_p, is_gimple_reg, fb_rvalue);
4156 *expr_p = build1 (INDIRECT_REF, TREE_TYPE (TREE_TYPE (tmp)), tmp);
4158 else if ((fallback & fb_rvalue) && is_gimple_formal_tmp_rhs (*expr_p))
4160 gcc_assert (!VOID_TYPE_P (TREE_TYPE (*expr_p)));
4162 /* An rvalue will do. Assign the gimplified expression into a new
4163 temporary TMP and replace the original expression with TMP. */
4165 if (internal_post || (fallback & fb_lvalue))
4166 /* The postqueue might change the value of the expression between
4167 the initialization and use of the temporary, so we can't use a
4168 formal temp. FIXME do we care? */
4169 *expr_p = get_initialized_tmp_var (*expr_p, pre_p, post_p);
4171 *expr_p = get_formal_tmp_var (*expr_p, pre_p);
4173 if (TREE_CODE (*expr_p) != SSA_NAME)
4174 DECL_GIMPLE_FORMAL_TEMP_P (*expr_p) = 1;
4178 #ifdef ENABLE_CHECKING
4179 if (!(fallback & fb_mayfail))
4181 fprintf (stderr, "gimplification failed:\n");
4182 print_generic_expr (stderr, *expr_p, 0);
4183 debug_tree (*expr_p);
4184 internal_error ("gimplification failed");
4187 gcc_assert (fallback & fb_mayfail);
4188 /* If this is an asm statement, and the user asked for the
4189 impossible, don't abort. Fail and let gimplify_asm_expr
4195 /* Make sure the temporary matches our predicate. */
4196 gcc_assert ((*gimple_test_f) (*expr_p));
4200 annotate_all_with_locus (&internal_post, input_location);
4201 append_to_statement_list (internal_post, pre_p);
4205 input_location = saved_location;
4209 /* Look through TYPE for variable-sized objects and gimplify each such
4210 size that we find. Add to LIST_P any statements generated. */
4213 gimplify_type_sizes (tree type, tree *list_p)
4217 /* Note that we do not check for TYPE_SIZES_GIMPLIFIED already set because
4218 that's not supposed to happen on types where gimplifcation does anything.
4219 We should assert that it isn't set, but we can indeed be called multiple
4220 times on pointers. Unfortunately, this includes fat pointers which we
4221 can't easily test for. We could pass TYPE down to gimplify_one_sizepos
4222 and test there, but it doesn't seem worth it. */
4224 /* We first do the main variant, then copy into any other variants. */
4225 type = TYPE_MAIN_VARIANT (type);
4227 switch (TREE_CODE (type))
4237 gimplify_one_sizepos (&TYPE_MIN_VALUE (type), list_p);
4238 gimplify_one_sizepos (&TYPE_MAX_VALUE (type), list_p);
4240 for (t = TYPE_NEXT_VARIANT (type); t; t = TYPE_NEXT_VARIANT (t))
4242 TYPE_MIN_VALUE (t) = TYPE_MIN_VALUE (type);
4243 TYPE_MAX_VALUE (t) = TYPE_MAX_VALUE (type);
4244 TYPE_SIZES_GIMPLIFIED (t) = 1;
4249 /* These types may not have declarations, so handle them here. */
4250 if (!TYPE_SIZES_GIMPLIFIED (TREE_TYPE (type)))
4251 gimplify_type_sizes (TREE_TYPE (type), list_p);
4253 if (!TYPE_SIZES_GIMPLIFIED (TYPE_DOMAIN (type)))
4254 gimplify_type_sizes (TYPE_DOMAIN (type), list_p);
4259 case QUAL_UNION_TYPE:
4260 for (field = TYPE_FIELDS (type); field; field = TREE_CHAIN (field))
4261 if (TREE_CODE (field) == FIELD_DECL)
4262 gimplify_one_sizepos (&DECL_FIELD_OFFSET (field), list_p);
4269 gimplify_one_sizepos (&TYPE_SIZE (type), list_p);
4270 gimplify_one_sizepos (&TYPE_SIZE_UNIT (type), list_p);
4272 for (t = TYPE_NEXT_VARIANT (type); t; t = TYPE_NEXT_VARIANT (t))
4274 TYPE_SIZE (t) = TYPE_SIZE (type);
4275 TYPE_SIZE_UNIT (t) = TYPE_SIZE_UNIT (type);
4276 TYPE_SIZES_GIMPLIFIED (t) = 1;
4279 TYPE_SIZES_GIMPLIFIED (type) = 1;
4282 /* A subroutine of gimplify_type_sizes to make sure that *EXPR_P,
4283 a size or position, has had all of its SAVE_EXPRs evaluated.
4284 We add any required statements to STMT_P. */
4287 gimplify_one_sizepos (tree *expr_p, tree *stmt_p)
4289 /* We don't do anything if the value isn't there, is constant, or contains
4290 A PLACEHOLDER_EXPR. We also don't want to do anything if it's already
4291 a VAR_DECL. If it's a VAR_DECL from another function, the gimplfier
4292 will want to replace it with a new variable, but that will cause problems
4293 if this type is from outside the function. It's OK to have that here. */
4294 if (*expr_p == NULL_TREE || TREE_CONSTANT (*expr_p)
4295 || TREE_CODE (*expr_p) == VAR_DECL
4296 || CONTAINS_PLACEHOLDER_P (*expr_p))
4299 *expr_p = unshare_expr (*expr_p);
4300 gimplify_expr (expr_p, stmt_p, NULL, is_gimple_val, fb_rvalue);
4303 #ifdef ENABLE_CHECKING
4304 /* Compare types A and B for a "close enough" match. */
4307 cpt_same_type (tree a, tree b)
4309 if (lang_hooks.types_compatible_p (a, b))
4312 /* ??? The C++ FE decomposes METHOD_TYPES to FUNCTION_TYPES and doesn't
4313 link them together. This routine is intended to catch type errors
4314 that will affect the optimizers, and the optimizers don't add new
4315 dereferences of function pointers, so ignore it. */
4316 if ((TREE_CODE (a) == FUNCTION_TYPE || TREE_CODE (a) == METHOD_TYPE)
4317 && (TREE_CODE (b) == FUNCTION_TYPE || TREE_CODE (b) == METHOD_TYPE))
4320 /* ??? The C FE pushes type qualifiers after the fact into the type of
4321 the element from the type of the array. See build_unary_op's handling
4322 of ADDR_EXPR. This seems wrong -- if we were going to do this, we
4323 should have done it when creating the variable in the first place.
4324 Alternately, why aren't the two array types made variants? */
4325 if (TREE_CODE (a) == ARRAY_TYPE && TREE_CODE (b) == ARRAY_TYPE)
4326 return cpt_same_type (TREE_TYPE (a), TREE_TYPE (b));
4328 /* And because of those, we have to recurse down through pointers. */
4329 if (POINTER_TYPE_P (a) && POINTER_TYPE_P (b))
4330 return cpt_same_type (TREE_TYPE (a), TREE_TYPE (b));
4335 /* Check for some cases of the front end missing cast expressions.
4336 The type of a dereference should correspond to the pointer type;
4337 similarly the type of an address should match its object. */
4340 check_pointer_types_r (tree *tp, int *walk_subtrees ATTRIBUTE_UNUSED,
4341 void *data ATTRIBUTE_UNUSED)
4344 tree ptype, otype, dtype;
4346 switch (TREE_CODE (t))
4350 otype = TREE_TYPE (t);
4351 ptype = TREE_TYPE (TREE_OPERAND (t, 0));
4352 dtype = TREE_TYPE (ptype);
4353 gcc_assert (cpt_same_type (otype, dtype));
4357 ptype = TREE_TYPE (t);
4358 otype = TREE_TYPE (TREE_OPERAND (t, 0));
4359 dtype = TREE_TYPE (ptype);
4360 if (!cpt_same_type (otype, dtype))
4362 /* &array is allowed to produce a pointer to the element, rather than
4363 a pointer to the array type. We must allow this in order to
4364 properly represent assigning the address of an array in C into
4365 pointer to the element type. */
4366 gcc_assert (TREE_CODE (otype) == ARRAY_TYPE
4367 && POINTER_TYPE_P (ptype)
4368 && cpt_same_type (TREE_TYPE (otype), dtype));
4382 /* Gimplify the body of statements pointed by BODY_P. FNDECL is the
4383 function decl containing BODY. */
4386 gimplify_body (tree *body_p, tree fndecl, bool do_parms)
4388 location_t saved_location = input_location;
4389 tree body, parm_stmts;
4391 timevar_push (TV_TREE_GIMPLIFY);
4392 push_gimplify_context ();
4394 /* Unshare most shared trees in the body and in that of any nested functions.
4395 It would seem we don't have to do this for nested functions because
4396 they are supposed to be output and then the outer function gimplified
4397 first, but the g++ front end doesn't always do it that way. */
4398 unshare_body (body_p, fndecl);
4399 unvisit_body (body_p, fndecl);
4401 /* Make sure input_location isn't set to something wierd. */
4402 input_location = DECL_SOURCE_LOCATION (fndecl);
4404 /* Resolve callee-copies. This has to be done before processing
4405 the body so that DECL_VALUE_EXPR gets processed correctly. */
4406 parm_stmts = do_parms ? gimplify_parameters () : NULL;
4408 /* Gimplify the function's body. */
4409 gimplify_stmt (body_p);
4413 body = alloc_stmt_list ();
4414 else if (TREE_CODE (body) == STATEMENT_LIST)
4416 tree t = expr_only (*body_p);
4421 /* If there isn't an outer BIND_EXPR, add one. */
4422 if (TREE_CODE (body) != BIND_EXPR)
4424 tree b = build (BIND_EXPR, void_type_node, NULL_TREE,
4425 NULL_TREE, NULL_TREE);
4426 TREE_SIDE_EFFECTS (b) = 1;
4427 append_to_statement_list_force (body, &BIND_EXPR_BODY (b));
4431 /* If we had callee-copies statements, insert them at the beginning
4435 append_to_statement_list_force (BIND_EXPR_BODY (body), &parm_stmts);
4436 BIND_EXPR_BODY (body) = parm_stmts;
4439 /* Unshare again, in case gimplification was sloppy. */
4440 unshare_all_trees (body);
4444 pop_gimplify_context (body);
4446 #ifdef ENABLE_CHECKING
4447 walk_tree (body_p, check_pointer_types_r, NULL, NULL);
4450 timevar_pop (TV_TREE_GIMPLIFY);
4451 input_location = saved_location;
4454 /* Entry point to the gimplification pass. FNDECL is the FUNCTION_DECL
4455 node for the function we want to gimplify. */
4458 gimplify_function_tree (tree fndecl)
4462 oldfn = current_function_decl;
4463 current_function_decl = fndecl;
4464 cfun = DECL_STRUCT_FUNCTION (fndecl);
4466 allocate_struct_function (fndecl);
4468 gimplify_body (&DECL_SAVED_TREE (fndecl), fndecl, true);
4470 /* If we're instrumenting function entry/exit, then prepend the call to
4471 the entry hook and wrap the whole function in a TRY_FINALLY_EXPR to
4472 catch the exit hook. */
4473 /* ??? Add some way to ignore exceptions for this TFE. */
4474 if (flag_instrument_function_entry_exit
4475 && ! DECL_NO_INSTRUMENT_FUNCTION_ENTRY_EXIT (fndecl))
4479 tf = build (TRY_FINALLY_EXPR, void_type_node, NULL, NULL);
4480 TREE_SIDE_EFFECTS (tf) = 1;
4481 x = DECL_SAVED_TREE (fndecl);
4482 append_to_statement_list (x, &TREE_OPERAND (tf, 0));
4483 x = implicit_built_in_decls[BUILT_IN_PROFILE_FUNC_EXIT];
4484 x = build_function_call_expr (x, NULL);
4485 append_to_statement_list (x, &TREE_OPERAND (tf, 1));
4487 bind = build (BIND_EXPR, void_type_node, NULL, NULL, NULL);
4488 TREE_SIDE_EFFECTS (bind) = 1;
4489 x = implicit_built_in_decls[BUILT_IN_PROFILE_FUNC_ENTER];
4490 x = build_function_call_expr (x, NULL);
4491 append_to_statement_list (x, &BIND_EXPR_BODY (bind));
4492 append_to_statement_list (tf, &BIND_EXPR_BODY (bind));
4494 DECL_SAVED_TREE (fndecl) = bind;
4497 current_function_decl = oldfn;
4498 cfun = oldfn ? DECL_STRUCT_FUNCTION (oldfn) : NULL;
4502 /* Expands EXPR to list of gimple statements STMTS. If SIMPLE is true,
4503 force the result to be either ssa_name or an invariant, otherwise
4504 just force it to be a rhs expression. If VAR is not NULL, make the
4505 base variable of the final destination be VAR if suitable. */
4508 force_gimple_operand (tree expr, tree *stmts, bool simple, tree var)
4511 enum gimplify_status ret;
4512 gimple_predicate gimple_test_f;
4516 if (is_gimple_val (expr))
4519 gimple_test_f = simple ? is_gimple_val : is_gimple_reg_rhs;
4521 push_gimplify_context ();
4522 gimplify_ctxp->into_ssa = true;
4525 expr = build (MODIFY_EXPR, TREE_TYPE (var), var, expr);
4527 ret = gimplify_expr (&expr, stmts, NULL,
4528 gimple_test_f, fb_rvalue);
4529 gcc_assert (ret != GS_ERROR);
4531 for (t = gimplify_ctxp->temps; t ; t = TREE_CHAIN (t))
4532 add_referenced_tmp_var (t);
4534 pop_gimplify_context (NULL);
4539 #include "gt-gimplify.h"