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 gimplify_type_sizes (TREE_TYPE (decl), stmt_p);
1000 gimplify_one_sizepos (&DECL_SIZE (decl), stmt_p);
1001 gimplify_one_sizepos (&DECL_SIZE_UNIT (decl), stmt_p);
1003 /* All occurrences of this decl in final gimplified code will be
1004 replaced by indirection. Setting DECL_VALUE_EXPR does two
1005 things: First, it lets the rest of the gimplifier know what
1006 replacement to use. Second, it lets the debug info know
1007 where to find the value. */
1008 ptr_type = build_pointer_type (TREE_TYPE (decl));
1009 addr = create_tmp_var (ptr_type, get_name (decl));
1010 DECL_IGNORED_P (addr) = 0;
1011 t = build_fold_indirect_ref (addr);
1012 DECL_VALUE_EXPR (decl) = t;
1014 args = tree_cons (NULL, DECL_SIZE_UNIT (decl), NULL);
1015 t = built_in_decls[BUILT_IN_ALLOCA];
1016 t = build_function_call_expr (t, args);
1017 t = fold_convert (ptr_type, t);
1018 t = build2 (MODIFY_EXPR, void_type_node, addr, t);
1020 gimplify_and_add (t, stmt_p);
1022 /* Indicate that we need to restore the stack level when the
1023 enclosing BIND_EXPR is exited. */
1024 gimplify_ctxp->save_stack = true;
1027 if (init && init != error_mark_node)
1029 if (!TREE_STATIC (decl))
1031 DECL_INITIAL (decl) = NULL_TREE;
1032 init = build (MODIFY_EXPR, void_type_node, decl, init);
1033 gimplify_and_add (init, stmt_p);
1036 /* We must still examine initializers for static variables
1037 as they may contain a label address. */
1038 walk_tree (&init, force_labels_r, NULL, NULL);
1041 /* This decl isn't mentioned in the enclosing block, so add it to the
1042 list of temps. FIXME it seems a bit of a kludge to say that
1043 anonymous artificial vars aren't pushed, but everything else is. */
1044 if (DECL_ARTIFICIAL (decl) && DECL_NAME (decl) == NULL_TREE)
1045 gimple_add_tmp_var (decl);
1051 /* Gimplify a LOOP_EXPR. Normally this just involves gimplifying the body
1052 and replacing the LOOP_EXPR with goto, but if the loop contains an
1053 EXIT_EXPR, we need to append a label for it to jump to. */
1055 static enum gimplify_status
1056 gimplify_loop_expr (tree *expr_p, tree *pre_p)
1058 tree saved_label = gimplify_ctxp->exit_label;
1059 tree start_label = build1 (LABEL_EXPR, void_type_node, NULL_TREE);
1060 tree jump_stmt = build_and_jump (&LABEL_EXPR_LABEL (start_label));
1062 append_to_statement_list (start_label, pre_p);
1064 gimplify_ctxp->exit_label = NULL_TREE;
1066 gimplify_and_add (LOOP_EXPR_BODY (*expr_p), pre_p);
1068 if (gimplify_ctxp->exit_label)
1070 append_to_statement_list (jump_stmt, pre_p);
1071 *expr_p = build1 (LABEL_EXPR, void_type_node, gimplify_ctxp->exit_label);
1074 *expr_p = jump_stmt;
1076 gimplify_ctxp->exit_label = saved_label;
1081 /* Compare two case labels. Because the front end should already have
1082 made sure that case ranges do not overlap, it is enough to only compare
1083 the CASE_LOW values of each case label. */
1086 compare_case_labels (const void *p1, const void *p2)
1088 tree case1 = *(tree *)p1;
1089 tree case2 = *(tree *)p2;
1091 return tree_int_cst_compare (CASE_LOW (case1), CASE_LOW (case2));
1094 /* Sort the case labels in LABEL_VEC in place in ascending order. */
1097 sort_case_labels (tree label_vec)
1099 size_t len = TREE_VEC_LENGTH (label_vec);
1100 tree default_case = TREE_VEC_ELT (label_vec, len - 1);
1102 if (CASE_LOW (default_case))
1106 /* The last label in the vector should be the default case
1108 for (i = 0; i < len; ++i)
1110 tree t = TREE_VEC_ELT (label_vec, i);
1114 TREE_VEC_ELT (label_vec, i) = TREE_VEC_ELT (label_vec, len - 1);
1115 TREE_VEC_ELT (label_vec, len - 1) = default_case;
1121 qsort (&TREE_VEC_ELT (label_vec, 0), len - 1, sizeof (tree),
1122 compare_case_labels);
1125 /* Gimplify a SWITCH_EXPR, and collect a TREE_VEC of the labels it can
1128 static enum gimplify_status
1129 gimplify_switch_expr (tree *expr_p, tree *pre_p)
1131 tree switch_expr = *expr_p;
1132 enum gimplify_status ret;
1134 ret = gimplify_expr (&SWITCH_COND (switch_expr), pre_p, NULL,
1135 is_gimple_val, fb_rvalue);
1137 if (SWITCH_BODY (switch_expr))
1139 varray_type labels, saved_labels;
1140 tree label_vec, default_case = NULL_TREE;
1143 /* If someone can be bothered to fill in the labels, they can
1144 be bothered to null out the body too. */
1145 gcc_assert (!SWITCH_LABELS (switch_expr));
1147 saved_labels = gimplify_ctxp->case_labels;
1148 VARRAY_TREE_INIT (gimplify_ctxp->case_labels, 8, "case_labels");
1150 gimplify_to_stmt_list (&SWITCH_BODY (switch_expr));
1152 labels = gimplify_ctxp->case_labels;
1153 gimplify_ctxp->case_labels = saved_labels;
1155 len = VARRAY_ACTIVE_SIZE (labels);
1157 for (i = 0; i < len; ++i)
1159 tree t = VARRAY_TREE (labels, i);
1162 /* The default case must be the last label in the list. */
1164 VARRAY_TREE (labels, i) = VARRAY_TREE (labels, len - 1);
1170 label_vec = make_tree_vec (len + 1);
1171 SWITCH_LABELS (*expr_p) = label_vec;
1172 append_to_statement_list (switch_expr, pre_p);
1176 /* If the switch has no default label, add one, so that we jump
1177 around the switch body. */
1178 default_case = build (CASE_LABEL_EXPR, void_type_node, NULL_TREE,
1179 NULL_TREE, create_artificial_label ());
1180 append_to_statement_list (SWITCH_BODY (switch_expr), pre_p);
1181 *expr_p = build (LABEL_EXPR, void_type_node,
1182 CASE_LABEL (default_case));
1185 *expr_p = SWITCH_BODY (switch_expr);
1187 for (i = 0; i < len; ++i)
1188 TREE_VEC_ELT (label_vec, i) = VARRAY_TREE (labels, i);
1189 TREE_VEC_ELT (label_vec, len) = default_case;
1191 sort_case_labels (label_vec);
1193 SWITCH_BODY (switch_expr) = NULL;
1196 gcc_assert (SWITCH_LABELS (switch_expr));
1201 static enum gimplify_status
1202 gimplify_case_label_expr (tree *expr_p)
1204 tree expr = *expr_p;
1206 gcc_assert (gimplify_ctxp->case_labels);
1207 VARRAY_PUSH_TREE (gimplify_ctxp->case_labels, expr);
1208 *expr_p = build (LABEL_EXPR, void_type_node, CASE_LABEL (expr));
1212 /* Build a GOTO to the LABEL_DECL pointed to by LABEL_P, building it first
1216 build_and_jump (tree *label_p)
1218 if (label_p == NULL)
1219 /* If there's nowhere to jump, just fall through. */
1222 if (*label_p == NULL_TREE)
1224 tree label = create_artificial_label ();
1228 return build1 (GOTO_EXPR, void_type_node, *label_p);
1231 /* Gimplify an EXIT_EXPR by converting to a GOTO_EXPR inside a COND_EXPR.
1232 This also involves building a label to jump to and communicating it to
1233 gimplify_loop_expr through gimplify_ctxp->exit_label. */
1235 static enum gimplify_status
1236 gimplify_exit_expr (tree *expr_p)
1238 tree cond = TREE_OPERAND (*expr_p, 0);
1241 expr = build_and_jump (&gimplify_ctxp->exit_label);
1242 expr = build (COND_EXPR, void_type_node, cond, expr, NULL_TREE);
1248 /* A helper function to be called via walk_tree. Mark all labels under *TP
1249 as being forced. To be called for DECL_INITIAL of static variables. */
1252 force_labels_r (tree *tp, int *walk_subtrees, void *data ATTRIBUTE_UNUSED)
1256 if (TREE_CODE (*tp) == LABEL_DECL)
1257 FORCED_LABEL (*tp) = 1;
1262 /* *EXPR_P is a COMPONENT_REF being used as an rvalue. If its type is
1263 different from its canonical type, wrap the whole thing inside a
1264 NOP_EXPR and force the type of the COMPONENT_REF to be the canonical
1267 The canonical type of a COMPONENT_REF is the type of the field being
1268 referenced--unless the field is a bit-field which can be read directly
1269 in a smaller mode, in which case the canonical type is the
1270 sign-appropriate type corresponding to that mode. */
1273 canonicalize_component_ref (tree *expr_p)
1275 tree expr = *expr_p;
1278 gcc_assert (TREE_CODE (expr) == COMPONENT_REF);
1280 if (INTEGRAL_TYPE_P (TREE_TYPE (expr)))
1281 type = TREE_TYPE (get_unwidened (expr, NULL_TREE));
1283 type = TREE_TYPE (TREE_OPERAND (expr, 1));
1285 if (TREE_TYPE (expr) != type)
1287 tree old_type = TREE_TYPE (expr);
1289 /* Set the type of the COMPONENT_REF to the underlying type. */
1290 TREE_TYPE (expr) = type;
1292 /* And wrap the whole thing inside a NOP_EXPR. */
1293 expr = build1 (NOP_EXPR, old_type, expr);
1299 /* If a NOP conversion is changing a pointer to array of foo to a pointer
1300 to foo, embed that change in the ADDR_EXPR by converting
1305 where L is the lower bound. For simplicity, only do this for constant
1309 canonicalize_addr_expr (tree *expr_p)
1311 tree expr = *expr_p;
1312 tree ctype = TREE_TYPE (expr);
1313 tree addr_expr = TREE_OPERAND (expr, 0);
1314 tree atype = TREE_TYPE (addr_expr);
1315 tree dctype, datype, ddatype, otype, obj_expr;
1317 /* Both cast and addr_expr types should be pointers. */
1318 if (!POINTER_TYPE_P (ctype) || !POINTER_TYPE_P (atype))
1321 /* The addr_expr type should be a pointer to an array. */
1322 datype = TREE_TYPE (atype);
1323 if (TREE_CODE (datype) != ARRAY_TYPE)
1326 /* Both cast and addr_expr types should address the same object type. */
1327 dctype = TREE_TYPE (ctype);
1328 ddatype = TREE_TYPE (datype);
1329 if (!lang_hooks.types_compatible_p (ddatype, dctype))
1332 /* The addr_expr and the object type should match. */
1333 obj_expr = TREE_OPERAND (addr_expr, 0);
1334 otype = TREE_TYPE (obj_expr);
1335 if (!lang_hooks.types_compatible_p (otype, datype))
1338 /* The lower bound and element sizes must be constant. */
1339 if (!TYPE_SIZE_UNIT (dctype)
1340 || TREE_CODE (TYPE_SIZE_UNIT (dctype)) != INTEGER_CST
1341 || !TYPE_DOMAIN (datype) || !TYPE_MIN_VALUE (TYPE_DOMAIN (datype))
1342 || TREE_CODE (TYPE_MIN_VALUE (TYPE_DOMAIN (datype))) != INTEGER_CST)
1345 /* All checks succeeded. Build a new node to merge the cast. */
1346 *expr_p = build4 (ARRAY_REF, dctype, obj_expr,
1347 TYPE_MIN_VALUE (TYPE_DOMAIN (datype)),
1348 TYPE_MIN_VALUE (TYPE_DOMAIN (datype)),
1349 size_binop (EXACT_DIV_EXPR, TYPE_SIZE_UNIT (dctype),
1350 size_int (TYPE_ALIGN_UNIT (dctype))));
1351 *expr_p = build1 (ADDR_EXPR, ctype, *expr_p);
1354 /* *EXPR_P is a NOP_EXPR or CONVERT_EXPR. Remove it and/or other conversions
1355 underneath as appropriate. */
1357 static enum gimplify_status
1358 gimplify_conversion (tree *expr_p)
1360 gcc_assert (TREE_CODE (*expr_p) == NOP_EXPR
1361 || TREE_CODE (*expr_p) == CONVERT_EXPR);
1363 /* Then strip away all but the outermost conversion. */
1364 STRIP_SIGN_NOPS (TREE_OPERAND (*expr_p, 0));
1366 /* And remove the outermost conversion if it's useless. */
1367 if (tree_ssa_useless_type_conversion (*expr_p))
1368 *expr_p = TREE_OPERAND (*expr_p, 0);
1370 /* If we still have a conversion at the toplevel,
1371 then canonicalize some constructs. */
1372 if (TREE_CODE (*expr_p) == NOP_EXPR || TREE_CODE (*expr_p) == CONVERT_EXPR)
1374 tree sub = TREE_OPERAND (*expr_p, 0);
1376 /* If a NOP conversion is changing the type of a COMPONENT_REF
1377 expression, then canonicalize its type now in order to expose more
1378 redundant conversions. */
1379 if (TREE_CODE (sub) == COMPONENT_REF)
1380 canonicalize_component_ref (&TREE_OPERAND (*expr_p, 0));
1382 /* If a NOP conversion is changing a pointer to array of foo
1383 to a pointer to foo, embed that change in the ADDR_EXPR. */
1384 else if (TREE_CODE (sub) == ADDR_EXPR)
1385 canonicalize_addr_expr (expr_p);
1391 /* Gimplify the COMPONENT_REF, ARRAY_REF, REALPART_EXPR or IMAGPART_EXPR
1392 node pointed by EXPR_P.
1395 : min_lval '[' val ']'
1397 | compound_lval '[' val ']'
1398 | compound_lval '.' ID
1400 This is not part of the original SIMPLE definition, which separates
1401 array and member references, but it seems reasonable to handle them
1402 together. Also, this way we don't run into problems with union
1403 aliasing; gcc requires that for accesses through a union to alias, the
1404 union reference must be explicit, which was not always the case when we
1405 were splitting up array and member refs.
1407 PRE_P points to the list where side effects that must happen before
1408 *EXPR_P should be stored.
1410 POST_P points to the list where side effects that must happen after
1411 *EXPR_P should be stored. */
1413 static enum gimplify_status
1414 gimplify_compound_lval (tree *expr_p, tree *pre_p,
1415 tree *post_p, fallback_t fallback)
1419 enum gimplify_status ret = GS_OK, tret;
1422 /* Create a stack of the subexpressions so later we can walk them in
1423 order from inner to outer.
1425 This array is very memory consuming. Don't even think of making
1427 VARRAY_GENERIC_PTR_NOGC_INIT (stack, 10, "stack");
1429 /* We can handle anything that get_inner_reference can deal with. */
1430 for (p = expr_p; handled_component_p (*p); p = &TREE_OPERAND (*p, 0))
1431 VARRAY_PUSH_GENERIC_PTR_NOGC (stack, *p);
1433 gcc_assert (VARRAY_ACTIVE_SIZE (stack));
1435 /* Now STACK is a stack of pointers to all the refs we've walked through
1436 and P points to the innermost expression.
1438 Java requires that we elaborated nodes in source order. That
1439 means we must gimplify the inner expression followed by each of
1440 the indices, in order. But we can't gimplify the inner
1441 expression until we deal with any variable bounds, sizes, or
1442 positions in order to deal with PLACEHOLDER_EXPRs.
1444 So we do this in three steps. First we deal with the annotations
1445 for any variables in the components, then we gimplify the base,
1446 then we gimplify any indices, from left to right. */
1447 for (i = VARRAY_ACTIVE_SIZE (stack) - 1; i >= 0; i--)
1449 tree t = VARRAY_GENERIC_PTR_NOGC (stack, i);
1451 if (TREE_CODE (t) == ARRAY_REF || TREE_CODE (t) == ARRAY_RANGE_REF)
1453 /* Gimplify the low bound and element type size and put them into
1454 the ARRAY_REF. If these values are set, they have already been
1456 if (!TREE_OPERAND (t, 2))
1458 tree low = unshare_expr (array_ref_low_bound (t));
1459 if (!is_gimple_min_invariant (low))
1461 TREE_OPERAND (t, 2) = low;
1462 tret = gimplify_expr (&TREE_OPERAND (t, 2), pre_p, post_p,
1463 is_gimple_formal_tmp_reg, fb_rvalue);
1464 ret = MIN (ret, tret);
1468 if (!TREE_OPERAND (t, 3))
1470 tree elmt_type = TREE_TYPE (TREE_TYPE (TREE_OPERAND (t, 0)));
1471 tree elmt_size = unshare_expr (array_ref_element_size (t));
1472 tree factor = size_int (TYPE_ALIGN_UNIT (elmt_type));
1474 /* Divide the element size by the alignment of the element
1476 elmt_size = size_binop (EXACT_DIV_EXPR, elmt_size, factor);
1478 if (!is_gimple_min_invariant (elmt_size))
1480 TREE_OPERAND (t, 3) = elmt_size;
1481 tret = gimplify_expr (&TREE_OPERAND (t, 3), pre_p, post_p,
1482 is_gimple_formal_tmp_reg, fb_rvalue);
1483 ret = MIN (ret, tret);
1487 else if (TREE_CODE (t) == COMPONENT_REF)
1489 /* Set the field offset into T and gimplify it. */
1490 if (!TREE_OPERAND (t, 2))
1492 tree offset = unshare_expr (component_ref_field_offset (t));
1493 tree field = TREE_OPERAND (t, 1);
1495 = size_int (DECL_OFFSET_ALIGN (field) / BITS_PER_UNIT);
1497 /* Divide the offset by its alignment. */
1498 offset = size_binop (EXACT_DIV_EXPR, offset, factor);
1500 if (!is_gimple_min_invariant (offset))
1502 TREE_OPERAND (t, 2) = offset;
1503 tret = gimplify_expr (&TREE_OPERAND (t, 2), pre_p, post_p,
1504 is_gimple_formal_tmp_reg, fb_rvalue);
1505 ret = MIN (ret, tret);
1511 /* Step 2 is to gimplify the base expression. */
1512 tret = gimplify_expr (p, pre_p, post_p, is_gimple_min_lval, fallback);
1513 ret = MIN (ret, tret);
1515 /* And finally, the indices and operands to BIT_FIELD_REF. During this
1516 loop we also remove any useless conversions. */
1517 for (; VARRAY_ACTIVE_SIZE (stack) > 0; )
1519 tree t = VARRAY_TOP_TREE (stack);
1521 if (TREE_CODE (t) == ARRAY_REF || TREE_CODE (t) == ARRAY_RANGE_REF)
1523 /* Gimplify the dimension.
1524 Temporary fix for gcc.c-torture/execute/20040313-1.c.
1525 Gimplify non-constant array indices into a temporary
1527 FIXME - The real fix is to gimplify post-modify
1528 expressions into a minimal gimple lvalue. However, that
1529 exposes bugs in alias analysis. The alias analyzer does
1530 not handle &PTR->FIELD very well. Will fix after the
1531 branch is merged into mainline (dnovillo 2004-05-03). */
1532 if (!is_gimple_min_invariant (TREE_OPERAND (t, 1)))
1534 tret = gimplify_expr (&TREE_OPERAND (t, 1), pre_p, post_p,
1535 is_gimple_formal_tmp_reg, fb_rvalue);
1536 ret = MIN (ret, tret);
1539 else if (TREE_CODE (t) == BIT_FIELD_REF)
1541 tret = gimplify_expr (&TREE_OPERAND (t, 1), pre_p, post_p,
1542 is_gimple_val, fb_rvalue);
1543 ret = MIN (ret, tret);
1544 tret = gimplify_expr (&TREE_OPERAND (t, 2), pre_p, post_p,
1545 is_gimple_val, fb_rvalue);
1546 ret = MIN (ret, tret);
1549 STRIP_USELESS_TYPE_CONVERSION (TREE_OPERAND (t, 0));
1551 /* The innermost expression P may have originally had TREE_SIDE_EFFECTS
1552 set which would have caused all the outer expressions in EXPR_P
1553 leading to P to also have had TREE_SIDE_EFFECTS set. */
1554 recalculate_side_effects (t);
1558 tret = gimplify_expr (p, pre_p, post_p, is_gimple_min_lval, fallback);
1559 ret = MIN (ret, tret);
1561 /* If the outermost expression is a COMPONENT_REF, canonicalize its type. */
1562 if ((fallback & fb_rvalue) && TREE_CODE (*expr_p) == COMPONENT_REF)
1564 canonicalize_component_ref (expr_p);
1565 ret = MIN (ret, GS_OK);
1568 VARRAY_FREE (stack);
1573 /* Gimplify the self modifying expression pointed by EXPR_P (++, --, +=, -=).
1575 PRE_P points to the list where side effects that must happen before
1576 *EXPR_P should be stored.
1578 POST_P points to the list where side effects that must happen after
1579 *EXPR_P should be stored.
1581 WANT_VALUE is nonzero iff we want to use the value of this expression
1582 in another expression. */
1584 static enum gimplify_status
1585 gimplify_self_mod_expr (tree *expr_p, tree *pre_p, tree *post_p,
1588 enum tree_code code;
1589 tree lhs, lvalue, rhs, t1;
1591 enum tree_code arith_code;
1592 enum gimplify_status ret;
1594 code = TREE_CODE (*expr_p);
1596 gcc_assert (code == POSTINCREMENT_EXPR || code == POSTDECREMENT_EXPR
1597 || code == PREINCREMENT_EXPR || code == PREDECREMENT_EXPR);
1599 /* Prefix or postfix? */
1600 if (code == POSTINCREMENT_EXPR || code == POSTDECREMENT_EXPR)
1601 /* Faster to treat as prefix if result is not used. */
1602 postfix = want_value;
1606 /* Add or subtract? */
1607 if (code == PREINCREMENT_EXPR || code == POSTINCREMENT_EXPR)
1608 arith_code = PLUS_EXPR;
1610 arith_code = MINUS_EXPR;
1612 /* Gimplify the LHS into a GIMPLE lvalue. */
1613 lvalue = TREE_OPERAND (*expr_p, 0);
1614 ret = gimplify_expr (&lvalue, pre_p, post_p, is_gimple_lvalue, fb_lvalue);
1615 if (ret == GS_ERROR)
1618 /* Extract the operands to the arithmetic operation. */
1620 rhs = TREE_OPERAND (*expr_p, 1);
1622 /* For postfix operator, we evaluate the LHS to an rvalue and then use
1623 that as the result value and in the postqueue operation. */
1626 ret = gimplify_expr (&lhs, pre_p, post_p, is_gimple_val, fb_rvalue);
1627 if (ret == GS_ERROR)
1631 t1 = build (arith_code, TREE_TYPE (*expr_p), lhs, rhs);
1632 t1 = build (MODIFY_EXPR, TREE_TYPE (lvalue), lvalue, t1);
1636 gimplify_and_add (t1, post_p);
1647 /* If *EXPR_P has a variable sized type, wrap it in a WITH_SIZE_EXPR. */
1650 maybe_with_size_expr (tree *expr_p)
1652 tree expr = *expr_p;
1653 tree type = TREE_TYPE (expr);
1656 /* If we've already wrapped this or the type is error_mark_node, we can't do
1658 if (TREE_CODE (expr) == WITH_SIZE_EXPR
1659 || type == error_mark_node)
1662 /* If the size isn't known or is a constant, we have nothing to do. */
1663 size = TYPE_SIZE_UNIT (type);
1664 if (!size || TREE_CODE (size) == INTEGER_CST)
1667 /* Otherwise, make a WITH_SIZE_EXPR. */
1668 size = unshare_expr (size);
1669 size = SUBSTITUTE_PLACEHOLDER_IN_EXPR (size, expr);
1670 *expr_p = build2 (WITH_SIZE_EXPR, type, expr, size);
1673 /* Subroutine of gimplify_call_expr: Gimplify a single argument. */
1675 static enum gimplify_status
1676 gimplify_arg (tree *expr_p, tree *pre_p)
1678 bool (*test) (tree);
1681 /* In general, we allow lvalues for function arguments to avoid
1682 extra overhead of copying large aggregates out of even larger
1683 aggregates into temporaries only to copy the temporaries to
1684 the argument list. Make optimizers happy by pulling out to
1685 temporaries those types that fit in registers. */
1686 if (is_gimple_reg_type (TREE_TYPE (*expr_p)))
1687 test = is_gimple_val, fb = fb_rvalue;
1689 test = is_gimple_lvalue, fb = fb_either;
1691 /* If this is a variable sized type, we must remember the size. */
1692 maybe_with_size_expr (expr_p);
1694 /* There is a sequence point before a function call. Side effects in
1695 the argument list must occur before the actual call. So, when
1696 gimplifying arguments, force gimplify_expr to use an internal
1697 post queue which is then appended to the end of PRE_P. */
1698 return gimplify_expr (expr_p, pre_p, NULL, test, fb);
1701 /* Gimplify the CALL_EXPR node pointed by EXPR_P. PRE_P points to the
1702 list where side effects that must happen before *EXPR_P should be stored.
1703 WANT_VALUE is true if the result of the call is desired. */
1705 static enum gimplify_status
1706 gimplify_call_expr (tree *expr_p, tree *pre_p, bool want_value)
1710 enum gimplify_status ret;
1712 gcc_assert (TREE_CODE (*expr_p) == CALL_EXPR);
1714 /* For reliable diagnostics during inlining, it is necessary that
1715 every call_expr be annotated with file and line. */
1716 if (! EXPR_HAS_LOCATION (*expr_p))
1717 SET_EXPR_LOCATION (*expr_p, input_location);
1719 /* This may be a call to a builtin function.
1721 Builtin function calls may be transformed into different
1722 (and more efficient) builtin function calls under certain
1723 circumstances. Unfortunately, gimplification can muck things
1724 up enough that the builtin expanders are not aware that certain
1725 transformations are still valid.
1727 So we attempt transformation/gimplification of the call before
1728 we gimplify the CALL_EXPR. At this time we do not manage to
1729 transform all calls in the same manner as the expanders do, but
1730 we do transform most of them. */
1731 decl = get_callee_fndecl (*expr_p);
1732 if (decl && DECL_BUILT_IN (decl))
1734 tree new = fold_builtin (*expr_p, !want_value);
1736 if (new && new != *expr_p)
1738 /* There was a transformation of this call which computes the
1739 same value, but in a more efficient way. Return and try
1745 if (DECL_FUNCTION_CODE (decl) == BUILT_IN_VA_START)
1747 tree arglist = TREE_OPERAND (*expr_p, 1);
1749 if (!arglist || !TREE_CHAIN (arglist))
1751 error ("too few arguments to function %<va_start%>");
1752 *expr_p = build_empty_stmt ();
1756 if (fold_builtin_next_arg (TREE_CHAIN (arglist)))
1758 *expr_p = build_empty_stmt ();
1761 /* Avoid gimplifying the second argument to va_start, which needs
1762 to be the plain PARM_DECL. */
1763 return gimplify_arg (&TREE_VALUE (TREE_OPERAND (*expr_p, 1)), pre_p);
1767 /* There is a sequence point before the call, so any side effects in
1768 the calling expression must occur before the actual call. Force
1769 gimplify_expr to use an internal post queue. */
1770 ret = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p, NULL,
1771 is_gimple_call_addr, fb_rvalue);
1773 if (PUSH_ARGS_REVERSED)
1774 TREE_OPERAND (*expr_p, 1) = nreverse (TREE_OPERAND (*expr_p, 1));
1775 for (arglist = TREE_OPERAND (*expr_p, 1); arglist;
1776 arglist = TREE_CHAIN (arglist))
1778 enum gimplify_status t;
1780 t = gimplify_arg (&TREE_VALUE (arglist), pre_p);
1785 if (PUSH_ARGS_REVERSED)
1786 TREE_OPERAND (*expr_p, 1) = nreverse (TREE_OPERAND (*expr_p, 1));
1788 /* Try this again in case gimplification exposed something. */
1789 if (ret != GS_ERROR && decl && DECL_BUILT_IN (decl))
1791 tree new = fold_builtin (*expr_p, !want_value);
1793 if (new && new != *expr_p)
1795 /* There was a transformation of this call which computes the
1796 same value, but in a more efficient way. Return and try
1803 /* If the function is "const" or "pure", then clear TREE_SIDE_EFFECTS on its
1804 decl. This allows us to eliminate redundant or useless
1805 calls to "const" functions. */
1806 if (TREE_CODE (*expr_p) == CALL_EXPR
1807 && (call_expr_flags (*expr_p) & (ECF_CONST | ECF_PURE)))
1808 TREE_SIDE_EFFECTS (*expr_p) = 0;
1813 /* Handle shortcut semantics in the predicate operand of a COND_EXPR by
1814 rewriting it into multiple COND_EXPRs, and possibly GOTO_EXPRs.
1816 TRUE_LABEL_P and FALSE_LABEL_P point to the labels to jump to if the
1817 condition is true or false, respectively. If null, we should generate
1818 our own to skip over the evaluation of this specific expression.
1820 This function is the tree equivalent of do_jump.
1822 shortcut_cond_r should only be called by shortcut_cond_expr. */
1825 shortcut_cond_r (tree pred, tree *true_label_p, tree *false_label_p)
1827 tree local_label = NULL_TREE;
1828 tree t, expr = NULL;
1830 /* OK, it's not a simple case; we need to pull apart the COND_EXPR to
1831 retain the shortcut semantics. Just insert the gotos here;
1832 shortcut_cond_expr will append the real blocks later. */
1833 if (TREE_CODE (pred) == TRUTH_ANDIF_EXPR)
1835 /* Turn if (a && b) into
1837 if (a); else goto no;
1838 if (b) goto yes; else goto no;
1841 if (false_label_p == NULL)
1842 false_label_p = &local_label;
1844 t = shortcut_cond_r (TREE_OPERAND (pred, 0), NULL, false_label_p);
1845 append_to_statement_list (t, &expr);
1847 t = shortcut_cond_r (TREE_OPERAND (pred, 1), true_label_p,
1849 append_to_statement_list (t, &expr);
1851 else if (TREE_CODE (pred) == TRUTH_ORIF_EXPR)
1853 /* Turn if (a || b) into
1856 if (b) goto yes; else goto no;
1859 if (true_label_p == NULL)
1860 true_label_p = &local_label;
1862 t = shortcut_cond_r (TREE_OPERAND (pred, 0), true_label_p, NULL);
1863 append_to_statement_list (t, &expr);
1865 t = shortcut_cond_r (TREE_OPERAND (pred, 1), true_label_p,
1867 append_to_statement_list (t, &expr);
1869 else if (TREE_CODE (pred) == COND_EXPR)
1871 /* As long as we're messing with gotos, turn if (a ? b : c) into
1873 if (b) goto yes; else goto no;
1875 if (c) goto yes; else goto no; */
1876 expr = build (COND_EXPR, void_type_node, TREE_OPERAND (pred, 0),
1877 shortcut_cond_r (TREE_OPERAND (pred, 1), true_label_p,
1879 shortcut_cond_r (TREE_OPERAND (pred, 2), true_label_p,
1884 expr = build (COND_EXPR, void_type_node, pred,
1885 build_and_jump (true_label_p),
1886 build_and_jump (false_label_p));
1891 t = build1 (LABEL_EXPR, void_type_node, local_label);
1892 append_to_statement_list (t, &expr);
1899 shortcut_cond_expr (tree expr)
1901 tree pred = TREE_OPERAND (expr, 0);
1902 tree then_ = TREE_OPERAND (expr, 1);
1903 tree else_ = TREE_OPERAND (expr, 2);
1904 tree true_label, false_label, end_label, t;
1906 tree *false_label_p;
1907 bool emit_end, emit_false;
1908 bool then_se = then_ && TREE_SIDE_EFFECTS (then_);
1909 bool else_se = else_ && TREE_SIDE_EFFECTS (else_);
1911 /* First do simple transformations. */
1914 /* If there is no 'else', turn (a && b) into if (a) if (b). */
1915 while (TREE_CODE (pred) == TRUTH_ANDIF_EXPR)
1917 TREE_OPERAND (expr, 0) = TREE_OPERAND (pred, 1);
1918 then_ = shortcut_cond_expr (expr);
1919 pred = TREE_OPERAND (pred, 0);
1920 expr = build (COND_EXPR, void_type_node, pred, then_, NULL_TREE);
1925 /* If there is no 'then', turn
1928 if (a); else if (b); else d. */
1929 while (TREE_CODE (pred) == TRUTH_ORIF_EXPR)
1931 TREE_OPERAND (expr, 0) = TREE_OPERAND (pred, 1);
1932 else_ = shortcut_cond_expr (expr);
1933 pred = TREE_OPERAND (pred, 0);
1934 expr = build (COND_EXPR, void_type_node, pred, NULL_TREE, else_);
1938 /* If we're done, great. */
1939 if (TREE_CODE (pred) != TRUTH_ANDIF_EXPR
1940 && TREE_CODE (pred) != TRUTH_ORIF_EXPR)
1943 /* Otherwise we need to mess with gotos. Change
1946 if (a); else goto no;
1949 and recursively gimplify the condition. */
1951 true_label = false_label = end_label = NULL_TREE;
1953 /* If our arms just jump somewhere, hijack those labels so we don't
1954 generate jumps to jumps. */
1957 && TREE_CODE (then_) == GOTO_EXPR
1958 && TREE_CODE (GOTO_DESTINATION (then_)) == LABEL_DECL)
1960 true_label = GOTO_DESTINATION (then_);
1966 && TREE_CODE (else_) == GOTO_EXPR
1967 && TREE_CODE (GOTO_DESTINATION (else_)) == LABEL_DECL)
1969 false_label = GOTO_DESTINATION (else_);
1974 /* If we aren't hijacking a label for the 'then' branch, it falls through. */
1976 true_label_p = &true_label;
1978 true_label_p = NULL;
1980 /* The 'else' branch also needs a label if it contains interesting code. */
1981 if (false_label || else_se)
1982 false_label_p = &false_label;
1984 false_label_p = NULL;
1986 /* If there was nothing else in our arms, just forward the label(s). */
1987 if (!then_se && !else_se)
1988 return shortcut_cond_r (pred, true_label_p, false_label_p);
1990 /* If our last subexpression already has a terminal label, reuse it. */
1992 expr = expr_last (else_);
1994 expr = expr_last (then_);
1997 if (expr && TREE_CODE (expr) == LABEL_EXPR)
1998 end_label = LABEL_EXPR_LABEL (expr);
2000 /* If we don't care about jumping to the 'else' branch, jump to the end
2001 if the condition is false. */
2003 false_label_p = &end_label;
2005 /* We only want to emit these labels if we aren't hijacking them. */
2006 emit_end = (end_label == NULL_TREE);
2007 emit_false = (false_label == NULL_TREE);
2009 pred = shortcut_cond_r (pred, true_label_p, false_label_p);
2012 append_to_statement_list (pred, &expr);
2014 append_to_statement_list (then_, &expr);
2017 t = build_and_jump (&end_label);
2018 append_to_statement_list (t, &expr);
2021 t = build1 (LABEL_EXPR, void_type_node, false_label);
2022 append_to_statement_list (t, &expr);
2024 append_to_statement_list (else_, &expr);
2026 if (emit_end && end_label)
2028 t = build1 (LABEL_EXPR, void_type_node, end_label);
2029 append_to_statement_list (t, &expr);
2035 /* EXPR is used in a boolean context; make sure it has BOOLEAN_TYPE. */
2038 gimple_boolify (tree expr)
2040 tree type = TREE_TYPE (expr);
2042 if (TREE_CODE (type) == BOOLEAN_TYPE)
2045 /* If this is the predicate of a COND_EXPR, it might not even be a
2047 expr = lang_hooks.truthvalue_conversion (expr);
2049 switch (TREE_CODE (expr))
2051 case TRUTH_AND_EXPR:
2053 case TRUTH_XOR_EXPR:
2054 case TRUTH_ANDIF_EXPR:
2055 case TRUTH_ORIF_EXPR:
2056 /* Also boolify the arguments of truth exprs. */
2057 TREE_OPERAND (expr, 1) = gimple_boolify (TREE_OPERAND (expr, 1));
2060 case TRUTH_NOT_EXPR:
2061 TREE_OPERAND (expr, 0) = gimple_boolify (TREE_OPERAND (expr, 0));
2064 case EQ_EXPR: case NE_EXPR:
2065 case LE_EXPR: case GE_EXPR: case LT_EXPR: case GT_EXPR:
2066 /* These expressions always produce boolean results. */
2067 TREE_TYPE (expr) = boolean_type_node;
2071 /* Other expressions that get here must have boolean values, but
2072 might need to be converted to the appropriate mode. */
2073 return convert (boolean_type_node, expr);
2077 /* Convert the conditional expression pointed by EXPR_P '(p) ? a : b;'
2086 The second form is used when *EXPR_P is of type void.
2088 TARGET is the tree for T1 above.
2090 PRE_P points to the list where side effects that must happen before
2091 *EXPR_P should be stored. */
2093 static enum gimplify_status
2094 gimplify_cond_expr (tree *expr_p, tree *pre_p, tree target)
2096 tree expr = *expr_p;
2097 tree tmp, tmp2, type;
2098 enum gimplify_status ret;
2100 type = TREE_TYPE (expr);
2102 TREE_TYPE (expr) = void_type_node;
2104 /* If this COND_EXPR has a value, copy the values into a temporary within
2106 else if (! VOID_TYPE_P (type))
2110 ret = gimplify_expr (&target, pre_p, NULL,
2111 is_gimple_min_lval, fb_lvalue);
2112 if (ret != GS_ERROR)
2115 tmp2 = unshare_expr (target);
2119 tmp2 = tmp = create_tmp_var (TREE_TYPE (expr), "iftmp");
2123 /* Build the then clause, 't1 = a;'. But don't build an assignment
2124 if this branch is void; in C++ it can be, if it's a throw. */
2125 if (TREE_TYPE (TREE_OPERAND (expr, 1)) != void_type_node)
2126 TREE_OPERAND (expr, 1)
2127 = build (MODIFY_EXPR, void_type_node, tmp, TREE_OPERAND (expr, 1));
2129 /* Build the else clause, 't1 = b;'. */
2130 if (TREE_TYPE (TREE_OPERAND (expr, 2)) != void_type_node)
2131 TREE_OPERAND (expr, 2)
2132 = build (MODIFY_EXPR, void_type_node, tmp2, TREE_OPERAND (expr, 2));
2134 TREE_TYPE (expr) = void_type_node;
2135 recalculate_side_effects (expr);
2137 /* Move the COND_EXPR to the prequeue. */
2138 gimplify_and_add (expr, pre_p);
2144 /* Make sure the condition has BOOLEAN_TYPE. */
2145 TREE_OPERAND (expr, 0) = gimple_boolify (TREE_OPERAND (expr, 0));
2147 /* Break apart && and || conditions. */
2148 if (TREE_CODE (TREE_OPERAND (expr, 0)) == TRUTH_ANDIF_EXPR
2149 || TREE_CODE (TREE_OPERAND (expr, 0)) == TRUTH_ORIF_EXPR)
2151 expr = shortcut_cond_expr (expr);
2153 if (expr != *expr_p)
2157 /* We can't rely on gimplify_expr to re-gimplify the expanded
2158 form properly, as cleanups might cause the target labels to be
2159 wrapped in a TRY_FINALLY_EXPR. To prevent that, we need to
2160 set up a conditional context. */
2161 gimple_push_condition ();
2162 gimplify_stmt (expr_p);
2163 gimple_pop_condition (pre_p);
2169 /* Now do the normal gimplification. */
2170 ret = gimplify_expr (&TREE_OPERAND (expr, 0), pre_p, NULL,
2171 is_gimple_condexpr, fb_rvalue);
2173 gimple_push_condition ();
2175 gimplify_to_stmt_list (&TREE_OPERAND (expr, 1));
2176 gimplify_to_stmt_list (&TREE_OPERAND (expr, 2));
2177 recalculate_side_effects (expr);
2179 gimple_pop_condition (pre_p);
2181 if (ret == GS_ERROR)
2183 else if (TREE_SIDE_EFFECTS (TREE_OPERAND (expr, 1)))
2185 else if (TREE_SIDE_EFFECTS (TREE_OPERAND (expr, 2)))
2186 /* Rewrite "if (a); else b" to "if (!a) b" */
2188 TREE_OPERAND (expr, 0) = invert_truthvalue (TREE_OPERAND (expr, 0));
2189 ret = gimplify_expr (&TREE_OPERAND (expr, 0), pre_p, NULL,
2190 is_gimple_condexpr, fb_rvalue);
2192 tmp = TREE_OPERAND (expr, 1);
2193 TREE_OPERAND (expr, 1) = TREE_OPERAND (expr, 2);
2194 TREE_OPERAND (expr, 2) = tmp;
2197 /* Both arms are empty; replace the COND_EXPR with its predicate. */
2198 expr = TREE_OPERAND (expr, 0);
2204 /* A subroutine of gimplify_modify_expr. Replace a MODIFY_EXPR with
2205 a call to __builtin_memcpy. */
2207 static enum gimplify_status
2208 gimplify_modify_expr_to_memcpy (tree *expr_p, tree size, bool want_value)
2210 tree args, t, to, to_ptr, from;
2212 to = TREE_OPERAND (*expr_p, 0);
2213 from = TREE_OPERAND (*expr_p, 1);
2215 args = tree_cons (NULL, size, NULL);
2217 t = build_fold_addr_expr (from);
2218 args = tree_cons (NULL, t, args);
2220 to_ptr = build_fold_addr_expr (to);
2221 args = tree_cons (NULL, to_ptr, args);
2222 t = implicit_built_in_decls[BUILT_IN_MEMCPY];
2223 t = build_function_call_expr (t, args);
2227 t = build1 (NOP_EXPR, TREE_TYPE (to_ptr), t);
2228 t = build1 (INDIRECT_REF, TREE_TYPE (to), t);
2235 /* A subroutine of gimplify_modify_expr. Replace a MODIFY_EXPR with
2236 a call to __builtin_memset. In this case we know that the RHS is
2237 a CONSTRUCTOR with an empty element list. */
2239 static enum gimplify_status
2240 gimplify_modify_expr_to_memset (tree *expr_p, tree size, bool want_value)
2242 tree args, t, to, to_ptr;
2244 to = TREE_OPERAND (*expr_p, 0);
2246 args = tree_cons (NULL, size, NULL);
2248 args = tree_cons (NULL, integer_zero_node, args);
2250 to_ptr = build_fold_addr_expr (to);
2251 args = tree_cons (NULL, to_ptr, args);
2252 t = implicit_built_in_decls[BUILT_IN_MEMSET];
2253 t = build_function_call_expr (t, args);
2257 t = build1 (NOP_EXPR, TREE_TYPE (to_ptr), t);
2258 t = build1 (INDIRECT_REF, TREE_TYPE (to), t);
2265 /* A subroutine of gimplify_init_ctor_preeval. Called via walk_tree,
2266 determine, cautiously, if a CONSTRUCTOR overlaps the lhs of an
2267 assignment. Returns non-null if we detect a potential overlap. */
2269 struct gimplify_init_ctor_preeval_data
2271 /* The base decl of the lhs object. May be NULL, in which case we
2272 have to assume the lhs is indirect. */
2275 /* The alias set of the lhs object. */
2280 gimplify_init_ctor_preeval_1 (tree *tp, int *walk_subtrees, void *xdata)
2282 struct gimplify_init_ctor_preeval_data *data
2283 = (struct gimplify_init_ctor_preeval_data *) xdata;
2286 /* If we find the base object, obviously we have overlap. */
2287 if (data->lhs_base_decl == t)
2290 /* If the constructor component is indirect, determine if we have a
2291 potential overlap with the lhs. The only bits of information we
2292 have to go on at this point are addressability and alias sets. */
2293 if (TREE_CODE (t) == INDIRECT_REF
2294 && (!data->lhs_base_decl || TREE_ADDRESSABLE (data->lhs_base_decl))
2295 && alias_sets_conflict_p (data->lhs_alias_set, get_alias_set (t)))
2298 if (IS_TYPE_OR_DECL_P (t))
2303 /* A subroutine of gimplify_init_constructor. Pre-evaluate *EXPR_P,
2304 force values that overlap with the lhs (as described by *DATA)
2305 into temporaries. */
2308 gimplify_init_ctor_preeval (tree *expr_p, tree *pre_p, tree *post_p,
2309 struct gimplify_init_ctor_preeval_data *data)
2311 enum gimplify_status one;
2313 /* If the value is invariant, then there's nothing to pre-evaluate.
2314 But ensure it doesn't have any side-effects since a SAVE_EXPR is
2315 invariant but has side effects and might contain a reference to
2316 the object we're initializing. */
2317 if (TREE_INVARIANT (*expr_p) && !TREE_SIDE_EFFECTS (*expr_p))
2320 /* If the type has non-trivial constructors, we can't pre-evaluate. */
2321 if (TREE_ADDRESSABLE (TREE_TYPE (*expr_p)))
2324 /* Recurse for nested constructors. */
2325 if (TREE_CODE (*expr_p) == CONSTRUCTOR)
2328 for (list = CONSTRUCTOR_ELTS (*expr_p); list ; list = TREE_CHAIN (list))
2329 gimplify_init_ctor_preeval (&TREE_VALUE (list), pre_p, post_p, data);
2333 /* We can't preevaluate if the type contains a placeholder. */
2334 if (type_contains_placeholder_p (TREE_TYPE (*expr_p)))
2337 /* Gimplify the constructor element to something appropriate for the rhs
2338 of a MODIFY_EXPR. Given that we know the lhs is an aggregate, we know
2339 the gimplifier will consider this a store to memory. Doing this
2340 gimplification now means that we won't have to deal with complicated
2341 language-specific trees, nor trees like SAVE_EXPR that can induce
2342 exponential search behavior. */
2343 one = gimplify_expr (expr_p, pre_p, post_p, is_gimple_mem_rhs, fb_rvalue);
2344 if (one == GS_ERROR)
2350 /* If we gimplified to a bare decl, we can be sure that it doesn't overlap
2351 with the lhs, since "a = { .x=a }" doesn't make sense. This will
2352 always be true for all scalars, since is_gimple_mem_rhs insists on a
2353 temporary variable for them. */
2354 if (DECL_P (*expr_p))
2357 /* If this is of variable size, we have no choice but to assume it doesn't
2358 overlap since we can't make a temporary for it. */
2359 if (!TREE_CONSTANT (TYPE_SIZE (TREE_TYPE (*expr_p))))
2362 /* Otherwise, we must search for overlap ... */
2363 if (!walk_tree (expr_p, gimplify_init_ctor_preeval_1, data, NULL))
2366 /* ... and if found, force the value into a temporary. */
2367 *expr_p = get_formal_tmp_var (*expr_p, pre_p);
2370 /* A subroutine of gimplify_init_constructor. Generate individual
2371 MODIFY_EXPRs for a CONSTRUCTOR. OBJECT is the LHS against which the
2372 assignments should happen. LIST is the CONSTRUCTOR_ELTS of the
2373 CONSTRUCTOR. CLEARED is true if the entire LHS object has been
2377 gimplify_init_ctor_eval (tree object, tree list, tree *pre_p, bool cleared)
2379 tree array_elt_type = NULL;
2381 if (TREE_CODE (TREE_TYPE (object)) == ARRAY_TYPE)
2382 array_elt_type = TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (object)));
2384 for (; list; list = TREE_CHAIN (list))
2386 tree purpose, value, cref, init;
2388 purpose = TREE_PURPOSE (list);
2389 value = TREE_VALUE (list);
2391 /* NULL values are created above for gimplification errors. */
2395 if (cleared && initializer_zerop (value))
2400 /* ??? Here's to hoping the front end fills in all of the indicies,
2401 so we don't have to figure out what's missing ourselves. */
2402 gcc_assert (purpose);
2403 /* ??? Need to handle this. */
2404 gcc_assert (TREE_CODE (purpose) != RANGE_EXPR);
2406 cref = build (ARRAY_REF, array_elt_type, unshare_expr (object),
2407 purpose, NULL_TREE, NULL_TREE);
2410 cref = build (COMPONENT_REF, TREE_TYPE (purpose),
2411 unshare_expr (object), purpose, NULL_TREE);
2413 if (TREE_CODE (value) == CONSTRUCTOR)
2414 gimplify_init_ctor_eval (cref, CONSTRUCTOR_ELTS (value),
2418 init = build (MODIFY_EXPR, TREE_TYPE (cref), cref, value);
2419 gimplify_and_add (init, pre_p);
2424 /* A subroutine of gimplify_modify_expr. Break out elements of a
2425 CONSTRUCTOR used as an initializer into separate MODIFY_EXPRs.
2427 Note that we still need to clear any elements that don't have explicit
2428 initializers, so if not all elements are initialized we keep the
2429 original MODIFY_EXPR, we just remove all of the constructor elements. */
2431 static enum gimplify_status
2432 gimplify_init_constructor (tree *expr_p, tree *pre_p,
2433 tree *post_p, bool want_value)
2436 tree ctor = TREE_OPERAND (*expr_p, 1);
2437 tree type = TREE_TYPE (ctor);
2438 enum gimplify_status ret;
2441 if (TREE_CODE (ctor) != CONSTRUCTOR)
2442 return GS_UNHANDLED;
2444 ret = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p, post_p,
2445 is_gimple_lvalue, fb_lvalue);
2446 if (ret == GS_ERROR)
2448 object = TREE_OPERAND (*expr_p, 0);
2450 elt_list = CONSTRUCTOR_ELTS (ctor);
2453 switch (TREE_CODE (type))
2457 case QUAL_UNION_TYPE:
2460 struct gimplify_init_ctor_preeval_data preeval_data;
2461 HOST_WIDE_INT num_elements, num_nonzero_elements;
2462 HOST_WIDE_INT num_nonconstant_elements;
2465 /* Aggregate types must lower constructors to initialization of
2466 individual elements. The exception is that a CONSTRUCTOR node
2467 with no elements indicates zero-initialization of the whole. */
2468 if (elt_list == NULL)
2471 categorize_ctor_elements (ctor, &num_nonzero_elements,
2472 &num_nonconstant_elements);
2474 /* If a const aggregate variable is being initialized, then it
2475 should never be a lose to promote the variable to be static. */
2476 if (num_nonconstant_elements == 0
2477 && TREE_READONLY (object)
2478 && TREE_CODE (object) == VAR_DECL)
2480 DECL_INITIAL (object) = ctor;
2481 TREE_STATIC (object) = 1;
2482 if (!DECL_NAME (object))
2483 DECL_NAME (object) = create_tmp_var_name ("C");
2484 walk_tree (&DECL_INITIAL (object), force_labels_r, NULL, NULL);
2486 /* ??? C++ doesn't automatically append a .<number> to the
2487 assembler name, and even when it does, it looks a FE private
2488 data structures to figure out what that number should be,
2489 which are not set for this variable. I suppose this is
2490 important for local statics for inline functions, which aren't
2491 "local" in the object file sense. So in order to get a unique
2492 TU-local symbol, we must invoke the lhd version now. */
2493 lhd_set_decl_assembler_name (object);
2495 *expr_p = NULL_TREE;
2499 /* If there are "lots" of initialized elements, and all of them
2500 are valid address constants, then the entire initializer can
2501 be dropped to memory, and then memcpy'd out. */
2502 if (num_nonconstant_elements == 0)
2504 HOST_WIDE_INT size = int_size_in_bytes (type);
2507 /* ??? We can still get unbounded array types, at least
2508 from the C++ front end. This seems wrong, but attempt
2509 to work around it for now. */
2512 size = int_size_in_bytes (TREE_TYPE (object));
2514 TREE_TYPE (ctor) = type = TREE_TYPE (object);
2517 /* Find the maximum alignment we can assume for the object. */
2518 /* ??? Make use of DECL_OFFSET_ALIGN. */
2519 if (DECL_P (object))
2520 align = DECL_ALIGN (object);
2522 align = TYPE_ALIGN (type);
2524 if (size > 0 && !can_move_by_pieces (size, align))
2526 tree new = create_tmp_var_raw (type, "C");
2528 gimple_add_tmp_var (new);
2529 TREE_STATIC (new) = 1;
2530 TREE_READONLY (new) = 1;
2531 DECL_INITIAL (new) = ctor;
2532 if (align > DECL_ALIGN (new))
2534 DECL_ALIGN (new) = align;
2535 DECL_USER_ALIGN (new) = 1;
2537 walk_tree (&DECL_INITIAL (new), force_labels_r, NULL, NULL);
2539 TREE_OPERAND (*expr_p, 1) = new;
2541 /* This is no longer an assignment of a CONSTRUCTOR, but
2542 we still may have processing to do on the LHS. So
2543 pretend we didn't do anything here to let that happen. */
2544 return GS_UNHANDLED;
2548 /* If there are "lots" of initialized elements, even discounting
2549 those that are not address constants (and thus *must* be
2550 computed at runtime), then partition the constructor into
2551 constant and non-constant parts. Block copy the constant
2552 parts in, then generate code for the non-constant parts. */
2553 /* TODO. There's code in cp/typeck.c to do this. */
2555 num_elements = count_type_elements (TREE_TYPE (ctor));
2557 /* If there are "lots" of zeros, then block clear the object first. */
2559 if (num_elements - num_nonzero_elements > CLEAR_RATIO
2560 && num_nonzero_elements < num_elements/4)
2563 /* ??? This bit ought not be needed. For any element not present
2564 in the initializer, we should simply set them to zero. Except
2565 we'd need to *find* the elements that are not present, and that
2566 requires trickery to avoid quadratic compile-time behavior in
2567 large cases or excessive memory use in small cases. */
2570 HOST_WIDE_INT len = list_length (elt_list);
2571 if (TREE_CODE (type) == ARRAY_TYPE)
2573 tree nelts = array_type_nelts (type);
2574 if (!host_integerp (nelts, 1)
2575 || tree_low_cst (nelts, 1) + 1 != len)
2578 else if (len != fields_length (type))
2584 /* Zap the CONSTRUCTOR element list, which simplifies this case.
2585 Note that we still have to gimplify, in order to handle the
2586 case of variable sized types. Avoid shared tree structures. */
2587 CONSTRUCTOR_ELTS (ctor) = NULL_TREE;
2588 object = unshare_expr (object);
2589 gimplify_stmt (expr_p);
2590 append_to_statement_list (*expr_p, pre_p);
2593 preeval_data.lhs_base_decl = get_base_address (object);
2594 if (!DECL_P (preeval_data.lhs_base_decl))
2595 preeval_data.lhs_base_decl = NULL;
2596 preeval_data.lhs_alias_set = get_alias_set (object);
2598 gimplify_init_ctor_preeval (&TREE_OPERAND (*expr_p, 1),
2599 pre_p, post_p, &preeval_data);
2600 gimplify_init_ctor_eval (object, elt_list, pre_p, cleared);
2602 *expr_p = NULL_TREE;
2610 /* Extract the real and imaginary parts out of the ctor. */
2614 r = TREE_VALUE (elt_list);
2615 elt_list = TREE_CHAIN (elt_list);
2618 i = TREE_VALUE (elt_list);
2619 gcc_assert (!TREE_CHAIN (elt_list));
2622 if (r == NULL || i == NULL)
2624 tree zero = convert (TREE_TYPE (type), integer_zero_node);
2631 /* Complex types have either COMPLEX_CST or COMPLEX_EXPR to
2632 represent creation of a complex value. */
2633 if (TREE_CONSTANT (r) && TREE_CONSTANT (i))
2635 ctor = build_complex (type, r, i);
2636 TREE_OPERAND (*expr_p, 1) = ctor;
2640 ctor = build (COMPLEX_EXPR, type, r, i);
2641 TREE_OPERAND (*expr_p, 1) = ctor;
2642 ret = gimplify_expr (&TREE_OPERAND (*expr_p, 1), pre_p, post_p,
2643 rhs_predicate_for (TREE_OPERAND (*expr_p, 0)),
2650 /* Go ahead and simplify constant constructors to VECTOR_CST. */
2651 if (TREE_CONSTANT (ctor))
2652 TREE_OPERAND (*expr_p, 1) = build_vector (type, elt_list);
2655 /* Vector types use CONSTRUCTOR all the way through gimple
2656 compilation as a general initializer. */
2657 for (; elt_list; elt_list = TREE_CHAIN (elt_list))
2659 enum gimplify_status tret;
2660 tret = gimplify_expr (&TREE_VALUE (elt_list), pre_p, post_p,
2661 is_gimple_val, fb_rvalue);
2662 if (tret == GS_ERROR)
2669 /* So how did we get a CONSTRUCTOR for a scalar type? */
2673 if (ret == GS_ERROR)
2675 else if (want_value)
2677 append_to_statement_list (*expr_p, pre_p);
2685 /* Subroutine of gimplify_modify_expr to do simplifications of MODIFY_EXPRs
2686 based on the code of the RHS. We loop for as long as something changes. */
2688 static enum gimplify_status
2689 gimplify_modify_expr_rhs (tree *expr_p, tree *from_p, tree *to_p, tree *pre_p,
2690 tree *post_p, bool want_value)
2692 enum gimplify_status ret = GS_OK;
2694 while (ret != GS_UNHANDLED)
2695 switch (TREE_CODE (*from_p))
2699 /* If we are initializing something from a TARGET_EXPR, strip the
2700 TARGET_EXPR and initialize it directly, if possible. This can't
2701 be done if the initializer is void, since that implies that the
2702 temporary is set in some non-trivial way.
2704 ??? What about code that pulls out the temp and uses it
2705 elsewhere? I think that such code never uses the TARGET_EXPR as
2706 an initializer. If I'm wrong, we'll abort because the temp won't
2707 have any RTL. In that case, I guess we'll need to replace
2708 references somehow. */
2709 tree init = TARGET_EXPR_INITIAL (*from_p);
2711 if (!VOID_TYPE_P (TREE_TYPE (init)))
2722 /* Remove any COMPOUND_EXPR in the RHS so the following cases will be
2724 gimplify_compound_expr (from_p, pre_p, true);
2729 /* If we're initializing from a CONSTRUCTOR, break this into
2730 individual MODIFY_EXPRs. */
2731 return gimplify_init_constructor (expr_p, pre_p, post_p, want_value);
2734 /* If we're assigning to a non-register type, push the assignment
2735 down into the branches. This is mandatory for ADDRESSABLE types,
2736 since we cannot generate temporaries for such, but it saves a
2737 copy in other cases as well. */
2738 if (!is_gimple_reg_type (TREE_TYPE (*from_p)))
2741 return gimplify_cond_expr (expr_p, pre_p, *to_p);
2755 /* Gimplify the MODIFY_EXPR node pointed by EXPR_P.
2761 PRE_P points to the list where side effects that must happen before
2762 *EXPR_P should be stored.
2764 POST_P points to the list where side effects that must happen after
2765 *EXPR_P should be stored.
2767 WANT_VALUE is nonzero iff we want to use the value of this expression
2768 in another expression. */
2770 static enum gimplify_status
2771 gimplify_modify_expr (tree *expr_p, tree *pre_p, tree *post_p, bool want_value)
2773 tree *from_p = &TREE_OPERAND (*expr_p, 1);
2774 tree *to_p = &TREE_OPERAND (*expr_p, 0);
2775 enum gimplify_status ret = GS_UNHANDLED;
2777 gcc_assert (TREE_CODE (*expr_p) == MODIFY_EXPR
2778 || TREE_CODE (*expr_p) == INIT_EXPR);
2780 /* The distinction between MODIFY_EXPR and INIT_EXPR is no longer useful. */
2781 if (TREE_CODE (*expr_p) == INIT_EXPR)
2782 TREE_SET_CODE (*expr_p, MODIFY_EXPR);
2784 /* See if any simplifications can be done based on what the RHS is. */
2785 ret = gimplify_modify_expr_rhs (expr_p, from_p, to_p, pre_p, post_p,
2787 if (ret != GS_UNHANDLED)
2790 /* If the value being copied is of variable width, compute the length
2791 of the copy into a WITH_SIZE_EXPR. Note that we need to do this
2792 before gimplifying any of the operands so that we can resolve any
2793 PLACEHOLDER_EXPRs in the size. Also note that the RTL expander uses
2794 the size of the expression to be copied, not of the destination, so
2795 that is what we must here. */
2796 maybe_with_size_expr (from_p);
2798 ret = gimplify_expr (to_p, pre_p, post_p, is_gimple_lvalue, fb_lvalue);
2799 if (ret == GS_ERROR)
2802 ret = gimplify_expr (from_p, pre_p, post_p,
2803 rhs_predicate_for (*to_p), fb_rvalue);
2804 if (ret == GS_ERROR)
2807 /* Now see if the above changed *from_p to something we handle specially. */
2808 ret = gimplify_modify_expr_rhs (expr_p, from_p, to_p, pre_p, post_p,
2810 if (ret != GS_UNHANDLED)
2813 /* If we've got a variable sized assignment between two lvalues (i.e. does
2814 not involve a call), then we can make things a bit more straightforward
2815 by converting the assignment to memcpy or memset. */
2816 if (TREE_CODE (*from_p) == WITH_SIZE_EXPR)
2818 tree from = TREE_OPERAND (*from_p, 0);
2819 tree size = TREE_OPERAND (*from_p, 1);
2821 if (TREE_CODE (from) == CONSTRUCTOR)
2822 return gimplify_modify_expr_to_memset (expr_p, size, want_value);
2823 if (is_gimple_addressable (from))
2826 return gimplify_modify_expr_to_memcpy (expr_p, size, want_value);
2830 if (gimplify_ctxp->into_ssa && is_gimple_reg (*to_p))
2832 /* If we've somehow already got an SSA_NAME on the LHS, then
2833 we're probably modifying it twice. Not good. */
2834 gcc_assert (TREE_CODE (*to_p) != SSA_NAME);
2835 *to_p = make_ssa_name (*to_p, *expr_p);
2840 append_to_statement_list (*expr_p, pre_p);
2848 /* Gimplify a comparison between two variable-sized objects. Do this
2849 with a call to BUILT_IN_MEMCMP. */
2851 static enum gimplify_status
2852 gimplify_variable_sized_compare (tree *expr_p)
2854 tree op0 = TREE_OPERAND (*expr_p, 0);
2855 tree op1 = TREE_OPERAND (*expr_p, 1);
2858 t = TYPE_SIZE_UNIT (TREE_TYPE (op0));
2859 t = unshare_expr (t);
2860 t = SUBSTITUTE_PLACEHOLDER_IN_EXPR (t, op0);
2861 args = tree_cons (NULL, t, NULL);
2862 t = build_fold_addr_expr (op1);
2863 args = tree_cons (NULL, t, args);
2864 dest = build_fold_addr_expr (op0);
2865 args = tree_cons (NULL, dest, args);
2866 t = implicit_built_in_decls[BUILT_IN_MEMCMP];
2867 t = build_function_call_expr (t, args);
2869 = build (TREE_CODE (*expr_p), TREE_TYPE (*expr_p), t, integer_zero_node);
2874 /* Gimplify TRUTH_ANDIF_EXPR and TRUTH_ORIF_EXPR expressions. EXPR_P
2875 points to the expression to gimplify.
2877 Expressions of the form 'a && b' are gimplified to:
2879 a && b ? true : false
2881 gimplify_cond_expr will do the rest.
2883 PRE_P points to the list where side effects that must happen before
2884 *EXPR_P should be stored. */
2886 static enum gimplify_status
2887 gimplify_boolean_expr (tree *expr_p)
2889 /* Preserve the original type of the expression. */
2890 tree type = TREE_TYPE (*expr_p);
2892 *expr_p = build (COND_EXPR, type, *expr_p,
2893 convert (type, boolean_true_node),
2894 convert (type, boolean_false_node));
2899 /* Gimplifies an expression sequence. This function gimplifies each
2900 expression and re-writes the original expression with the last
2901 expression of the sequence in GIMPLE form.
2903 PRE_P points to the list where the side effects for all the
2904 expressions in the sequence will be emitted.
2906 WANT_VALUE is true when the result of the last COMPOUND_EXPR is used. */
2907 /* ??? Should rearrange to share the pre-queue with all the indirect
2908 invocations of gimplify_expr. Would probably save on creations
2909 of statement_list nodes. */
2911 static enum gimplify_status
2912 gimplify_compound_expr (tree *expr_p, tree *pre_p, bool want_value)
2918 tree *sub_p = &TREE_OPERAND (t, 0);
2920 if (TREE_CODE (*sub_p) == COMPOUND_EXPR)
2921 gimplify_compound_expr (sub_p, pre_p, false);
2923 gimplify_stmt (sub_p);
2924 append_to_statement_list (*sub_p, pre_p);
2926 t = TREE_OPERAND (t, 1);
2928 while (TREE_CODE (t) == COMPOUND_EXPR);
2935 gimplify_stmt (expr_p);
2940 /* Gimplifies a statement list. These may be created either by an
2941 enlightened front-end, or by shortcut_cond_expr. */
2943 static enum gimplify_status
2944 gimplify_statement_list (tree *expr_p)
2946 tree_stmt_iterator i = tsi_start (*expr_p);
2948 while (!tsi_end_p (i))
2952 gimplify_stmt (tsi_stmt_ptr (i));
2957 else if (TREE_CODE (t) == STATEMENT_LIST)
2959 tsi_link_before (&i, t, TSI_SAME_STMT);
2969 /* Gimplify a SAVE_EXPR node. EXPR_P points to the expression to
2970 gimplify. After gimplification, EXPR_P will point to a new temporary
2971 that holds the original value of the SAVE_EXPR node.
2973 PRE_P points to the list where side effects that must happen before
2974 *EXPR_P should be stored. */
2976 static enum gimplify_status
2977 gimplify_save_expr (tree *expr_p, tree *pre_p, tree *post_p)
2979 enum gimplify_status ret = GS_ALL_DONE;
2982 gcc_assert (TREE_CODE (*expr_p) == SAVE_EXPR);
2983 val = TREE_OPERAND (*expr_p, 0);
2985 /* If the SAVE_EXPR has not been resolved, then evaluate it once. */
2986 if (!SAVE_EXPR_RESOLVED_P (*expr_p))
2988 /* The operand may be a void-valued expression such as SAVE_EXPRs
2989 generated by the Java frontend for class initialization. It is
2990 being executed only for its side-effects. */
2991 if (TREE_TYPE (val) == void_type_node)
2993 ret = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p, post_p,
2994 is_gimple_stmt, fb_none);
2995 append_to_statement_list (TREE_OPERAND (*expr_p, 0), pre_p);
2999 val = get_initialized_tmp_var (val, pre_p, post_p);
3001 TREE_OPERAND (*expr_p, 0) = val;
3002 SAVE_EXPR_RESOLVED_P (*expr_p) = 1;
3010 /* Re-write the ADDR_EXPR node pointed by EXPR_P
3017 PRE_P points to the list where side effects that must happen before
3018 *EXPR_P should be stored.
3020 POST_P points to the list where side effects that must happen after
3021 *EXPR_P should be stored. */
3023 static enum gimplify_status
3024 gimplify_addr_expr (tree *expr_p, tree *pre_p, tree *post_p)
3026 tree expr = *expr_p;
3027 tree op0 = TREE_OPERAND (expr, 0);
3028 enum gimplify_status ret;
3030 switch (TREE_CODE (op0))
3033 case MISALIGNED_INDIRECT_REF:
3035 /* Check if we are dealing with an expression of the form '&*ptr'.
3036 While the front end folds away '&*ptr' into 'ptr', these
3037 expressions may be generated internally by the compiler (e.g.,
3038 builtins like __builtin_va_end). */
3039 /* Caution: the silent array decomposition semantics we allow for
3040 ADDR_EXPR means we can't always discard the pair. */
3042 tree op00 = TREE_OPERAND (op0, 0);
3043 tree t_expr = TREE_TYPE (expr);
3044 tree t_op00 = TREE_TYPE (op00);
3046 if (!lang_hooks.types_compatible_p (t_expr, t_op00))
3048 #ifdef ENABLE_CHECKING
3049 tree t_op0 = TREE_TYPE (op0);
3050 gcc_assert (TREE_CODE (t_op0) == ARRAY_TYPE
3051 && POINTER_TYPE_P (t_expr)
3052 && cpt_same_type (TREE_TYPE (t_op0),
3054 && POINTER_TYPE_P (t_op00)
3055 && cpt_same_type (t_op0, TREE_TYPE (t_op00)));
3057 op00 = fold_convert (TREE_TYPE (expr), op00);
3064 case VIEW_CONVERT_EXPR:
3065 /* Take the address of our operand and then convert it to the type of
3068 ??? The interactions of VIEW_CONVERT_EXPR and aliasing is not at
3069 all clear. The impact of this transformation is even less clear. */
3071 /* If the operand is a useless conversion, look through it. Doing so
3072 guarantees that the ADDR_EXPR and its operand will remain of the
3074 if (tree_ssa_useless_type_conversion (TREE_OPERAND (op0, 0)))
3075 op0 = TREE_OPERAND (op0, 0);
3077 *expr_p = fold_convert (TREE_TYPE (expr),
3078 build_fold_addr_expr (TREE_OPERAND (op0, 0)));
3083 /* We use fb_either here because the C frontend sometimes takes
3084 the address of a call that returns a struct; see
3085 gcc.dg/c99-array-lval-1.c. The gimplifier will correctly make
3086 the implied temporary explicit. */
3087 ret = gimplify_expr (&TREE_OPERAND (expr, 0), pre_p, post_p,
3088 is_gimple_addressable, fb_either);
3089 if (ret != GS_ERROR)
3091 op0 = TREE_OPERAND (expr, 0);
3093 /* For various reasons, the gimplification of the expression
3094 may have made a new INDIRECT_REF. */
3095 if (TREE_CODE (op0) == INDIRECT_REF)
3096 goto do_indirect_ref;
3098 /* Make sure TREE_INVARIANT, TREE_CONSTANT, and TREE_SIDE_EFFECTS
3100 recompute_tree_invarant_for_addr_expr (expr);
3102 /* Mark the RHS addressable. */
3103 lang_hooks.mark_addressable (TREE_OPERAND (expr, 0));
3111 /* Gimplify the operands of an ASM_EXPR. Input operands should be a gimple
3112 value; output operands should be a gimple lvalue. */
3114 static enum gimplify_status
3115 gimplify_asm_expr (tree *expr_p, tree *pre_p, tree *post_p)
3117 tree expr = *expr_p;
3118 int noutputs = list_length (ASM_OUTPUTS (expr));
3119 const char **oconstraints
3120 = (const char **) alloca ((noutputs) * sizeof (const char *));
3123 const char *constraint;
3124 bool allows_mem, allows_reg, is_inout;
3125 enum gimplify_status ret, tret;
3128 = resolve_asm_operand_names (ASM_STRING (expr), ASM_OUTPUTS (expr),
3132 for (i = 0, link = ASM_OUTPUTS (expr); link; ++i, link = TREE_CHAIN (link))
3134 size_t constraint_len;
3135 oconstraints[i] = constraint
3136 = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (link)));
3137 constraint_len = strlen (constraint);
3138 if (constraint_len == 0)
3141 parse_output_constraint (&constraint, i, 0, 0,
3142 &allows_mem, &allows_reg, &is_inout);
3144 if (!allows_reg && allows_mem)
3145 lang_hooks.mark_addressable (TREE_VALUE (link));
3147 tret = gimplify_expr (&TREE_VALUE (link), pre_p, post_p,
3148 is_inout ? is_gimple_min_lval : is_gimple_lvalue,
3149 fb_lvalue | fb_mayfail);
3150 if (tret == GS_ERROR)
3152 error ("invalid lvalue in asm output %d", i);
3158 /* An input/output operand. To give the optimizers more
3159 flexibility, split it into separate input and output
3164 /* Turn the in/out constraint into an output constraint. */
3165 char *p = xstrdup (constraint);
3167 TREE_VALUE (TREE_PURPOSE (link)) = build_string (constraint_len, p);
3170 /* And add a matching input constraint. */
3173 sprintf (buf, "%d", i);
3174 input = build_string (strlen (buf), buf);
3177 input = build_string (constraint_len - 1, constraint + 1);
3178 input = build_tree_list (build_tree_list (NULL_TREE, input),
3179 unshare_expr (TREE_VALUE (link)));
3180 ASM_INPUTS (expr) = chainon (ASM_INPUTS (expr), input);
3184 for (link = ASM_INPUTS (expr); link; ++i, link = TREE_CHAIN (link))
3187 = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (link)));
3188 parse_input_constraint (&constraint, 0, 0, noutputs, 0,
3189 oconstraints, &allows_mem, &allows_reg);
3191 /* If the operand is a memory input, it should be an lvalue. */
3192 if (!allows_reg && allows_mem)
3194 lang_hooks.mark_addressable (TREE_VALUE (link));
3195 tret = gimplify_expr (&TREE_VALUE (link), pre_p, post_p,
3196 is_gimple_lvalue, fb_lvalue | fb_mayfail);
3197 if (tret == GS_ERROR)
3199 error ("memory input %d is not directly addressable", i);
3205 tret = gimplify_expr (&TREE_VALUE (link), pre_p, post_p,
3206 is_gimple_asm_val, fb_rvalue);
3207 if (tret == GS_ERROR)
3215 /* Gimplify a CLEANUP_POINT_EXPR. Currently this works by adding
3216 WITH_CLEANUP_EXPRs to the prequeue as we encounter cleanups while
3217 gimplifying the body, and converting them to TRY_FINALLY_EXPRs when we
3218 return to this function.
3220 FIXME should we complexify the prequeue handling instead? Or use flags
3221 for all the cleanups and let the optimizer tighten them up? The current
3222 code seems pretty fragile; it will break on a cleanup within any
3223 non-conditional nesting. But any such nesting would be broken, anyway;
3224 we can't write a TRY_FINALLY_EXPR that starts inside a nesting construct
3225 and continues out of it. We can do that at the RTL level, though, so
3226 having an optimizer to tighten up try/finally regions would be a Good
3229 static enum gimplify_status
3230 gimplify_cleanup_point_expr (tree *expr_p, tree *pre_p)
3232 tree_stmt_iterator iter;
3235 tree temp = voidify_wrapper_expr (*expr_p, NULL);
3237 /* We only care about the number of conditions between the innermost
3238 CLEANUP_POINT_EXPR and the cleanup. So save and reset the count. */
3239 int old_conds = gimplify_ctxp->conditions;
3240 gimplify_ctxp->conditions = 0;
3242 body = TREE_OPERAND (*expr_p, 0);
3243 gimplify_to_stmt_list (&body);
3245 gimplify_ctxp->conditions = old_conds;
3247 for (iter = tsi_start (body); !tsi_end_p (iter); )
3249 tree *wce_p = tsi_stmt_ptr (iter);
3252 if (TREE_CODE (wce) == WITH_CLEANUP_EXPR)
3254 if (tsi_one_before_end_p (iter))
3256 tsi_link_before (&iter, TREE_OPERAND (wce, 0), TSI_SAME_STMT);
3263 enum tree_code code;
3265 if (CLEANUP_EH_ONLY (wce))
3266 code = TRY_CATCH_EXPR;
3268 code = TRY_FINALLY_EXPR;
3270 sl = tsi_split_statement_list_after (&iter);
3271 tfe = build (code, void_type_node, sl, NULL_TREE);
3272 append_to_statement_list (TREE_OPERAND (wce, 0),
3273 &TREE_OPERAND (tfe, 1));
3275 iter = tsi_start (sl);
3285 append_to_statement_list (body, pre_p);
3295 /* Insert a cleanup marker for gimplify_cleanup_point_expr. CLEANUP
3296 is the cleanup action required. */
3299 gimple_push_cleanup (tree var, tree cleanup, bool eh_only, tree *pre_p)
3303 /* Errors can result in improperly nested cleanups. Which results in
3304 confusion when trying to resolve the WITH_CLEANUP_EXPR. */
3305 if (errorcount || sorrycount)
3308 if (gimple_conditional_context ())
3310 /* If we're in a conditional context, this is more complex. We only
3311 want to run the cleanup if we actually ran the initialization that
3312 necessitates it, but we want to run it after the end of the
3313 conditional context. So we wrap the try/finally around the
3314 condition and use a flag to determine whether or not to actually
3315 run the destructor. Thus
3319 becomes (approximately)
3323 if (test) { A::A(temp); flag = 1; val = f(temp); }
3326 if (flag) A::~A(temp);
3331 tree flag = create_tmp_var (boolean_type_node, "cleanup");
3332 tree ffalse = build (MODIFY_EXPR, void_type_node, flag,
3333 boolean_false_node);
3334 tree ftrue = build (MODIFY_EXPR, void_type_node, flag,
3336 cleanup = build (COND_EXPR, void_type_node, flag, cleanup, NULL);
3337 wce = build (WITH_CLEANUP_EXPR, void_type_node, cleanup);
3338 append_to_statement_list (ffalse, &gimplify_ctxp->conditional_cleanups);
3339 append_to_statement_list (wce, &gimplify_ctxp->conditional_cleanups);
3340 append_to_statement_list (ftrue, pre_p);
3342 /* Because of this manipulation, and the EH edges that jump
3343 threading cannot redirect, the temporary (VAR) will appear
3344 to be used uninitialized. Don't warn. */
3345 TREE_NO_WARNING (var) = 1;
3349 wce = build (WITH_CLEANUP_EXPR, void_type_node, cleanup);
3350 CLEANUP_EH_ONLY (wce) = eh_only;
3351 append_to_statement_list (wce, pre_p);
3354 gimplify_stmt (&TREE_OPERAND (wce, 0));
3357 /* Gimplify a TARGET_EXPR which doesn't appear on the rhs of an INIT_EXPR. */
3359 static enum gimplify_status
3360 gimplify_target_expr (tree *expr_p, tree *pre_p, tree *post_p)
3362 tree targ = *expr_p;
3363 tree temp = TARGET_EXPR_SLOT (targ);
3364 tree init = TARGET_EXPR_INITIAL (targ);
3365 enum gimplify_status ret;
3369 /* TARGET_EXPR temps aren't part of the enclosing block, so add it
3370 to the temps list. */
3371 gimple_add_tmp_var (temp);
3373 /* If TARGET_EXPR_INITIAL is void, then the mere evaluation of the
3374 expression is supposed to initialize the slot. */
3375 if (VOID_TYPE_P (TREE_TYPE (init)))
3376 ret = gimplify_expr (&init, pre_p, post_p, is_gimple_stmt, fb_none);
3379 /* Special handling for BIND_EXPR can result in fewer temps. */
3381 if (TREE_CODE (init) == BIND_EXPR)
3382 gimplify_bind_expr (&init, temp, pre_p);
3385 init = build (MODIFY_EXPR, void_type_node, temp, init);
3386 ret = gimplify_expr (&init, pre_p, post_p, is_gimple_stmt,
3390 if (ret == GS_ERROR)
3392 append_to_statement_list (init, pre_p);
3394 /* If needed, push the cleanup for the temp. */
3395 if (TARGET_EXPR_CLEANUP (targ))
3397 gimplify_stmt (&TARGET_EXPR_CLEANUP (targ));
3398 gimple_push_cleanup (temp, TARGET_EXPR_CLEANUP (targ),
3399 CLEANUP_EH_ONLY (targ), pre_p);
3402 /* Only expand this once. */
3403 TREE_OPERAND (targ, 3) = init;
3404 TARGET_EXPR_INITIAL (targ) = NULL_TREE;
3407 /* We should have expanded this before. */
3408 gcc_assert (DECL_SEEN_IN_BIND_EXPR_P (temp));
3414 /* Gimplification of expression trees. */
3416 /* Gimplify an expression which appears at statement context; usually, this
3417 means replacing it with a suitably gimple STATEMENT_LIST. */
3420 gimplify_stmt (tree *stmt_p)
3422 gimplify_expr (stmt_p, NULL, NULL, is_gimple_stmt, fb_none);
3425 /* Similarly, but force the result to be a STATEMENT_LIST. */
3428 gimplify_to_stmt_list (tree *stmt_p)
3430 gimplify_stmt (stmt_p);
3432 *stmt_p = alloc_stmt_list ();
3433 else if (TREE_CODE (*stmt_p) != STATEMENT_LIST)
3436 *stmt_p = alloc_stmt_list ();
3437 append_to_statement_list (t, stmt_p);
3442 /* Gimplifies the expression tree pointed by EXPR_P. Return 0 if
3443 gimplification failed.
3445 PRE_P points to the list where side effects that must happen before
3446 EXPR should be stored.
3448 POST_P points to the list where side effects that must happen after
3449 EXPR should be stored, or NULL if there is no suitable list. In
3450 that case, we copy the result to a temporary, emit the
3451 post-effects, and then return the temporary.
3453 GIMPLE_TEST_F points to a function that takes a tree T and
3454 returns nonzero if T is in the GIMPLE form requested by the
3455 caller. The GIMPLE predicates are in tree-gimple.c.
3457 This test is used twice. Before gimplification, the test is
3458 invoked to determine whether *EXPR_P is already gimple enough. If
3459 that fails, *EXPR_P is gimplified according to its code and
3460 GIMPLE_TEST_F is called again. If the test still fails, then a new
3461 temporary variable is created and assigned the value of the
3462 gimplified expression.
3464 FALLBACK tells the function what sort of a temporary we want. If the 1
3465 bit is set, an rvalue is OK. If the 2 bit is set, an lvalue is OK.
3466 If both are set, either is OK, but an lvalue is preferable.
3468 The return value is either GS_ERROR or GS_ALL_DONE, since this function
3469 iterates until solution. */
3471 enum gimplify_status
3472 gimplify_expr (tree *expr_p, tree *pre_p, tree *post_p,
3473 bool (* gimple_test_f) (tree), fallback_t fallback)
3476 tree internal_pre = NULL_TREE;
3477 tree internal_post = NULL_TREE;
3479 int is_statement = (pre_p == NULL);
3480 location_t saved_location;
3481 enum gimplify_status ret;
3483 save_expr = *expr_p;
3484 if (save_expr == NULL_TREE)
3487 /* We used to check the predicate here and return immediately if it
3488 succeeds. This is wrong; the design is for gimplification to be
3489 idempotent, and for the predicates to only test for valid forms, not
3490 whether they are fully simplified. */
3492 /* Set up our internal queues if needed. */
3494 pre_p = &internal_pre;
3496 post_p = &internal_post;
3498 saved_location = input_location;
3499 if (save_expr != error_mark_node
3500 && EXPR_HAS_LOCATION (*expr_p))
3501 input_location = EXPR_LOCATION (*expr_p);
3503 /* Loop over the specific gimplifiers until the toplevel node
3504 remains the same. */
3507 /* Strip away as many useless type conversions as possible
3509 STRIP_USELESS_TYPE_CONVERSION (*expr_p);
3511 /* Remember the expr. */
3512 save_expr = *expr_p;
3514 /* Die, die, die, my darling. */
3515 if (save_expr == error_mark_node
3516 || (TREE_TYPE (save_expr)
3517 && TREE_TYPE (save_expr) == error_mark_node))
3523 /* Do any language-specific gimplification. */
3524 ret = lang_hooks.gimplify_expr (expr_p, pre_p, post_p);
3527 if (*expr_p == NULL_TREE)
3529 if (*expr_p != save_expr)
3532 else if (ret != GS_UNHANDLED)
3536 switch (TREE_CODE (*expr_p))
3538 /* First deal with the special cases. */
3540 case POSTINCREMENT_EXPR:
3541 case POSTDECREMENT_EXPR:
3542 case PREINCREMENT_EXPR:
3543 case PREDECREMENT_EXPR:
3544 ret = gimplify_self_mod_expr (expr_p, pre_p, post_p,
3545 fallback != fb_none);
3549 case ARRAY_RANGE_REF:
3553 case VIEW_CONVERT_EXPR:
3554 ret = gimplify_compound_lval (expr_p, pre_p, post_p,
3555 fallback ? fallback : fb_rvalue);
3559 ret = gimplify_cond_expr (expr_p, pre_p, NULL_TREE);
3563 ret = gimplify_call_expr (expr_p, pre_p, fallback != fb_none);
3570 ret = gimplify_compound_expr (expr_p, pre_p, fallback != fb_none);
3575 ret = gimplify_modify_expr (expr_p, pre_p, post_p,
3576 fallback != fb_none);
3579 case TRUTH_ANDIF_EXPR:
3580 case TRUTH_ORIF_EXPR:
3581 ret = gimplify_boolean_expr (expr_p);
3584 case TRUTH_NOT_EXPR:
3585 TREE_OPERAND (*expr_p, 0)
3586 = gimple_boolify (TREE_OPERAND (*expr_p, 0));
3587 ret = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p, post_p,
3588 is_gimple_val, fb_rvalue);
3589 recalculate_side_effects (*expr_p);
3593 ret = gimplify_addr_expr (expr_p, pre_p, post_p);
3597 ret = gimplify_va_arg_expr (expr_p, pre_p, post_p);
3602 if (IS_EMPTY_STMT (*expr_p))
3608 if (VOID_TYPE_P (TREE_TYPE (*expr_p))
3609 || fallback == fb_none)
3611 /* Just strip a conversion to void (or in void context) and
3613 *expr_p = TREE_OPERAND (*expr_p, 0);
3617 ret = gimplify_conversion (expr_p);
3618 if (ret == GS_ERROR)
3620 if (*expr_p != save_expr)
3624 case FIX_TRUNC_EXPR:
3626 case FIX_FLOOR_EXPR:
3627 case FIX_ROUND_EXPR:
3628 /* unary_expr: ... | '(' cast ')' val | ... */
3629 ret = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p, post_p,
3630 is_gimple_val, fb_rvalue);
3631 recalculate_side_effects (*expr_p);
3634 case ALIGN_INDIRECT_REF:
3635 case MISALIGNED_INDIRECT_REF:
3637 ret = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p, post_p,
3638 is_gimple_reg, fb_rvalue);
3639 recalculate_side_effects (*expr_p);
3642 /* Constants need not be gimplified. */
3652 /* If we require an lvalue, such as for ADDR_EXPR, retain the
3653 CONST_DECL node. Otherwise the decl is replaceable by its
3655 /* ??? Should be == fb_lvalue, but ADDR_EXPR passes fb_either. */
3656 if (fallback & fb_lvalue)
3659 *expr_p = DECL_INITIAL (*expr_p);
3663 ret = gimplify_decl_expr (expr_p);
3667 /* FIXME make this a decl. */
3672 ret = gimplify_bind_expr (expr_p, NULL, pre_p);
3676 ret = gimplify_loop_expr (expr_p, pre_p);
3680 ret = gimplify_switch_expr (expr_p, pre_p);
3684 ret = gimplify_exit_expr (expr_p);
3688 /* If the target is not LABEL, then it is a computed jump
3689 and the target needs to be gimplified. */
3690 if (TREE_CODE (GOTO_DESTINATION (*expr_p)) != LABEL_DECL)
3691 ret = gimplify_expr (&GOTO_DESTINATION (*expr_p), pre_p,
3692 NULL, is_gimple_val, fb_rvalue);
3697 gcc_assert (decl_function_context (LABEL_EXPR_LABEL (*expr_p))
3698 == current_function_decl);
3701 case CASE_LABEL_EXPR:
3702 ret = gimplify_case_label_expr (expr_p);
3706 ret = gimplify_return_expr (*expr_p, pre_p);
3710 /* Don't reduce this in place; let gimplify_init_constructor work its
3711 magic. Buf if we're just elaborating this for side effects, just
3712 gimplify any element that has side-effects. */
3713 if (fallback == fb_none)
3715 for (tmp = CONSTRUCTOR_ELTS (*expr_p); tmp;
3716 tmp = TREE_CHAIN (tmp))
3717 if (TREE_SIDE_EFFECTS (TREE_VALUE (tmp)))
3718 gimplify_expr (&TREE_VALUE (tmp), pre_p, post_p,
3719 gimple_test_f, fallback);
3721 *expr_p = NULL_TREE;
3727 /* The following are special cases that are not handled by the
3728 original GIMPLE grammar. */
3730 /* SAVE_EXPR nodes are converted into a GIMPLE identifier and
3733 ret = gimplify_save_expr (expr_p, pre_p, post_p);
3738 enum gimplify_status r0, r1, r2;
3740 r0 = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p, post_p,
3741 is_gimple_lvalue, fb_either);
3742 r1 = gimplify_expr (&TREE_OPERAND (*expr_p, 1), pre_p, post_p,
3743 is_gimple_val, fb_rvalue);
3744 r2 = gimplify_expr (&TREE_OPERAND (*expr_p, 2), pre_p, post_p,
3745 is_gimple_val, fb_rvalue);
3746 recalculate_side_effects (*expr_p);
3748 ret = MIN (r0, MIN (r1, r2));
3752 case NON_LVALUE_EXPR:
3753 /* This should have been stripped above. */
3757 ret = gimplify_asm_expr (expr_p, pre_p, post_p);
3760 case TRY_FINALLY_EXPR:
3761 case TRY_CATCH_EXPR:
3762 gimplify_to_stmt_list (&TREE_OPERAND (*expr_p, 0));
3763 gimplify_to_stmt_list (&TREE_OPERAND (*expr_p, 1));
3767 case CLEANUP_POINT_EXPR:
3768 ret = gimplify_cleanup_point_expr (expr_p, pre_p);
3772 ret = gimplify_target_expr (expr_p, pre_p, post_p);
3776 gimplify_to_stmt_list (&CATCH_BODY (*expr_p));
3780 case EH_FILTER_EXPR:
3781 gimplify_to_stmt_list (&EH_FILTER_FAILURE (*expr_p));
3787 enum gimplify_status r0, r1;
3788 r0 = gimplify_expr (&OBJ_TYPE_REF_OBJECT (*expr_p), pre_p, post_p,
3789 is_gimple_val, fb_rvalue);
3790 r1 = gimplify_expr (&OBJ_TYPE_REF_EXPR (*expr_p), pre_p, post_p,
3791 is_gimple_val, fb_rvalue);
3797 /* We get here when taking the address of a label. We mark
3798 the label as "forced"; meaning it can never be removed and
3799 it is a potential target for any computed goto. */
3800 FORCED_LABEL (*expr_p) = 1;
3804 case STATEMENT_LIST:
3805 ret = gimplify_statement_list (expr_p);
3808 case WITH_SIZE_EXPR:
3810 enum gimplify_status r0, r1;
3811 r0 = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p,
3812 post_p == &internal_post ? NULL : post_p,
3813 gimple_test_f, fallback);
3814 r1 = gimplify_expr (&TREE_OPERAND (*expr_p, 1), pre_p, post_p,
3815 is_gimple_val, fb_rvalue);
3820 /* ??? If this is a local variable, and it has not been seen in any
3821 outer BIND_EXPR, then it's probably the result of a duplicate
3822 declaration, for which we've already issued an error. It would
3823 be really nice if the front end wouldn't leak these at all.
3824 Currently the only known culprit is C++ destructors, as seen
3825 in g++.old-deja/g++.jason/binding.C. */
3827 if (!TREE_STATIC (tmp) && !DECL_EXTERNAL (tmp)
3828 && decl_function_context (tmp) == current_function_decl
3829 && !DECL_SEEN_IN_BIND_EXPR_P (tmp))
3831 gcc_assert (errorcount || sorrycount);
3836 /* If this is a local variable sized decl, it must be accessed
3837 indirectly. Perform that substitution. */
3838 if (DECL_VALUE_EXPR (tmp))
3840 *expr_p = unshare_expr (DECL_VALUE_EXPR (tmp));
3849 /* Allow callbacks into the gimplifier during optimization. */
3854 switch (TREE_CODE_CLASS (TREE_CODE (*expr_p)))
3856 case tcc_comparison:
3857 /* If this is a comparison of objects of aggregate type,
3858 handle it specially (by converting to a call to
3859 memcmp). It would be nice to only have to do this
3860 for variable-sized objects, but then we'd have to
3861 allow the same nest of reference nodes we allow for
3862 MODIFY_EXPR and that's too complex. */
3863 if (!AGGREGATE_TYPE_P (TREE_TYPE (TREE_OPERAND (*expr_p, 1))))
3865 ret = gimplify_variable_sized_compare (expr_p);
3868 /* If *EXPR_P does not need to be special-cased, handle it
3869 according to its class. */
3871 ret = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p,
3872 post_p, is_gimple_val, fb_rvalue);
3878 enum gimplify_status r0, r1;
3880 r0 = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p,
3881 post_p, is_gimple_val, fb_rvalue);
3882 r1 = gimplify_expr (&TREE_OPERAND (*expr_p, 1), pre_p,
3883 post_p, is_gimple_val, fb_rvalue);
3889 case tcc_declaration:
3892 goto dont_recalculate;
3895 gcc_assert (TREE_CODE (*expr_p) == TRUTH_AND_EXPR
3896 || TREE_CODE (*expr_p) == TRUTH_OR_EXPR
3897 || TREE_CODE (*expr_p) == TRUTH_XOR_EXPR);
3901 recalculate_side_effects (*expr_p);
3906 /* If we replaced *expr_p, gimplify again. */
3907 if (ret == GS_OK && (*expr_p == NULL || *expr_p == save_expr))
3910 while (ret == GS_OK);
3912 /* If we encountered an error_mark somewhere nested inside, either
3913 stub out the statement or propagate the error back out. */
3914 if (ret == GS_ERROR)
3921 /* This was only valid as a return value from the langhook, which
3922 we handled. Make sure it doesn't escape from any other context. */
3923 gcc_assert (ret != GS_UNHANDLED);
3925 if (fallback == fb_none && *expr_p && !is_gimple_stmt (*expr_p))
3927 /* We aren't looking for a value, and we don't have a valid
3928 statement. If it doesn't have side-effects, throw it away. */
3929 if (!TREE_SIDE_EFFECTS (*expr_p))
3931 else if (!TREE_THIS_VOLATILE (*expr_p))
3933 /* This is probably a _REF that contains something nested that
3934 has side effects. Recurse through the operands to find it. */
3935 enum tree_code code = TREE_CODE (*expr_p);
3940 case REALPART_EXPR: case IMAGPART_EXPR:
3941 gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p, post_p,
3942 gimple_test_f, fallback);
3945 case ARRAY_REF: case ARRAY_RANGE_REF:
3946 gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p, post_p,
3947 gimple_test_f, fallback);
3948 gimplify_expr (&TREE_OPERAND (*expr_p, 1), pre_p, post_p,
3949 gimple_test_f, fallback);
3953 /* Anything else with side-effects must be converted to
3954 a valid statement before we get here. */
3960 else if (COMPLETE_TYPE_P (TREE_TYPE (*expr_p)))
3962 /* Historically, the compiler has treated a bare
3963 reference to a volatile lvalue as forcing a load. */
3964 tree tmp = create_tmp_var (TREE_TYPE (*expr_p), "vol");
3965 *expr_p = build (MODIFY_EXPR, TREE_TYPE (tmp), tmp, *expr_p);
3968 /* We can't do anything useful with a volatile reference to
3969 incomplete type, so just throw it away. */
3973 /* If we are gimplifying at the statement level, we're done. Tack
3974 everything together and replace the original statement with the
3976 if (fallback == fb_none || is_statement)
3978 if (internal_pre || internal_post)
3980 append_to_statement_list (*expr_p, &internal_pre);
3981 append_to_statement_list (internal_post, &internal_pre);
3982 annotate_all_with_locus (&internal_pre, input_location);
3983 *expr_p = internal_pre;
3987 else if (TREE_CODE (*expr_p) == STATEMENT_LIST)
3988 annotate_all_with_locus (expr_p, input_location);
3990 annotate_one_with_locus (*expr_p, input_location);
3994 /* Otherwise we're gimplifying a subexpression, so the resulting value is
3997 /* If it's sufficiently simple already, we're done. Unless we are
3998 handling some post-effects internally; if that's the case, we need to
3999 copy into a temp before adding the post-effects to the tree. */
4000 if (!internal_post && (*gimple_test_f) (*expr_p))
4003 /* Otherwise, we need to create a new temporary for the gimplified
4006 /* We can't return an lvalue if we have an internal postqueue. The
4007 object the lvalue refers to would (probably) be modified by the
4008 postqueue; we need to copy the value out first, which means an
4010 if ((fallback & fb_lvalue) && !internal_post
4011 && is_gimple_addressable (*expr_p))
4013 /* An lvalue will do. Take the address of the expression, store it
4014 in a temporary, and replace the expression with an INDIRECT_REF of
4016 tmp = build_fold_addr_expr (*expr_p);
4017 gimplify_expr (&tmp, pre_p, post_p, is_gimple_reg, fb_rvalue);
4018 *expr_p = build1 (INDIRECT_REF, TREE_TYPE (TREE_TYPE (tmp)), tmp);
4020 else if ((fallback & fb_rvalue) && is_gimple_formal_tmp_rhs (*expr_p))
4022 gcc_assert (!VOID_TYPE_P (TREE_TYPE (*expr_p)));
4024 /* An rvalue will do. Assign the gimplified expression into a new
4025 temporary TMP and replace the original expression with TMP. */
4027 if (internal_post || (fallback & fb_lvalue))
4028 /* The postqueue might change the value of the expression between
4029 the initialization and use of the temporary, so we can't use a
4030 formal temp. FIXME do we care? */
4031 *expr_p = get_initialized_tmp_var (*expr_p, pre_p, post_p);
4033 *expr_p = get_formal_tmp_var (*expr_p, pre_p);
4035 if (TREE_CODE (*expr_p) != SSA_NAME)
4036 DECL_GIMPLE_FORMAL_TEMP_P (*expr_p) = 1;
4040 #ifdef ENABLE_CHECKING
4041 if (!(fallback & fb_mayfail))
4043 fprintf (stderr, "gimplification failed:\n");
4044 print_generic_expr (stderr, *expr_p, 0);
4045 debug_tree (*expr_p);
4046 internal_error ("gimplification failed");
4049 gcc_assert (fallback & fb_mayfail);
4050 /* If this is an asm statement, and the user asked for the
4051 impossible, don't abort. Fail and let gimplify_asm_expr
4057 /* Make sure the temporary matches our predicate. */
4058 gcc_assert ((*gimple_test_f) (*expr_p));
4062 annotate_all_with_locus (&internal_post, input_location);
4063 append_to_statement_list (internal_post, pre_p);
4067 input_location = saved_location;
4071 /* Look through TYPE for variable-sized objects and gimplify each such
4072 size that we find. Add to LIST_P any statements generated. */
4075 gimplify_type_sizes (tree type, tree *list_p)
4079 switch (TREE_CODE (type))
4089 gimplify_one_sizepos (&TYPE_MIN_VALUE (type), list_p);
4090 gimplify_one_sizepos (&TYPE_MAX_VALUE (type), list_p);
4094 /* These anonymous types don't have declarations, so handle them here. */
4095 gimplify_type_sizes (TYPE_DOMAIN (type), list_p);
4100 case QUAL_UNION_TYPE:
4101 for (field = TYPE_FIELDS (type); field; field = TREE_CHAIN (field))
4102 if (TREE_CODE (field) == FIELD_DECL)
4103 gimplify_one_sizepos (&DECL_FIELD_OFFSET (field), list_p);
4110 gimplify_one_sizepos (&TYPE_SIZE (type), list_p);
4111 gimplify_one_sizepos (&TYPE_SIZE_UNIT (type), list_p);
4114 /* Subroutine of the above to gimplify one size or position, *EXPR_P.
4115 We add any required statements to STMT_P. */
4118 gimplify_one_sizepos (tree *expr_p, tree *stmt_p)
4120 /* We don't do anything if the value isn't there, is constant, or contains
4121 A PLACEHOLDER_EXPR. We also don't want to do anything if it's already
4122 a VAR_DECL. If it's a VAR_DECL from another function, the gimplfier
4123 will want to replace it with a new variable, but that will cause problems
4124 if this type is from outside the function. It's OK to have that here. */
4125 if (*expr_p == NULL_TREE || TREE_CONSTANT (*expr_p)
4126 || TREE_CODE (*expr_p) == VAR_DECL
4127 || CONTAINS_PLACEHOLDER_P (*expr_p))
4130 gimplify_expr (expr_p, stmt_p, NULL, is_gimple_val, fb_rvalue);
4133 #ifdef ENABLE_CHECKING
4134 /* Compare types A and B for a "close enough" match. */
4137 cpt_same_type (tree a, tree b)
4139 if (lang_hooks.types_compatible_p (a, b))
4142 /* ??? The C++ FE decomposes METHOD_TYPES to FUNCTION_TYPES and doesn't
4143 link them together. This routine is intended to catch type errors
4144 that will affect the optimizers, and the optimizers don't add new
4145 dereferences of function pointers, so ignore it. */
4146 if ((TREE_CODE (a) == FUNCTION_TYPE || TREE_CODE (a) == METHOD_TYPE)
4147 && (TREE_CODE (b) == FUNCTION_TYPE || TREE_CODE (b) == METHOD_TYPE))
4150 /* ??? The C FE pushes type qualifiers after the fact into the type of
4151 the element from the type of the array. See build_unary_op's handling
4152 of ADDR_EXPR. This seems wrong -- if we were going to do this, we
4153 should have done it when creating the variable in the first place.
4154 Alternately, why aren't the two array types made variants? */
4155 if (TREE_CODE (a) == ARRAY_TYPE && TREE_CODE (b) == ARRAY_TYPE)
4156 return cpt_same_type (TREE_TYPE (a), TREE_TYPE (b));
4158 /* And because of those, we have to recurse down through pointers. */
4159 if (POINTER_TYPE_P (a) && POINTER_TYPE_P (b))
4160 return cpt_same_type (TREE_TYPE (a), TREE_TYPE (b));
4165 /* Check for some cases of the front end missing cast expressions.
4166 The type of a dereference should correspond to the pointer type;
4167 similarly the type of an address should match its object. */
4170 check_pointer_types_r (tree *tp, int *walk_subtrees ATTRIBUTE_UNUSED,
4171 void *data ATTRIBUTE_UNUSED)
4174 tree ptype, otype, dtype;
4176 switch (TREE_CODE (t))
4180 otype = TREE_TYPE (t);
4181 ptype = TREE_TYPE (TREE_OPERAND (t, 0));
4182 dtype = TREE_TYPE (ptype);
4183 gcc_assert (cpt_same_type (otype, dtype));
4187 ptype = TREE_TYPE (t);
4188 otype = TREE_TYPE (TREE_OPERAND (t, 0));
4189 dtype = TREE_TYPE (ptype);
4190 if (!cpt_same_type (otype, dtype))
4192 /* &array is allowed to produce a pointer to the element, rather than
4193 a pointer to the array type. We must allow this in order to
4194 properly represent assigning the address of an array in C into
4195 pointer to the element type. */
4196 gcc_assert (TREE_CODE (otype) == ARRAY_TYPE
4197 && POINTER_TYPE_P (ptype)
4198 && cpt_same_type (TREE_TYPE (otype), dtype));
4212 /* Gimplify the body of statements pointed by BODY_P. FNDECL is the
4213 function decl containing BODY. */
4216 gimplify_body (tree *body_p, tree fndecl)
4218 location_t saved_location = input_location;
4221 timevar_push (TV_TREE_GIMPLIFY);
4222 push_gimplify_context ();
4224 /* Unshare most shared trees in the body and in that of any nested functions.
4225 It would seem we don't have to do this for nested functions because
4226 they are supposed to be output and then the outer function gimplified
4227 first, but the g++ front end doesn't always do it that way. */
4228 unshare_body (body_p, fndecl);
4229 unvisit_body (body_p, fndecl);
4231 /* Make sure input_location isn't set to something wierd. */
4232 input_location = DECL_SOURCE_LOCATION (fndecl);
4234 /* Gimplify the function's body. */
4235 gimplify_stmt (body_p);
4238 /* Unshare again, in case gimplification was sloppy. */
4239 unshare_all_trees (body);
4242 body = alloc_stmt_list ();
4243 else if (TREE_CODE (body) == STATEMENT_LIST)
4245 tree t = expr_only (*body_p);
4250 /* If there isn't an outer BIND_EXPR, add one. */
4251 if (TREE_CODE (body) != BIND_EXPR)
4253 tree b = build (BIND_EXPR, void_type_node, NULL_TREE,
4254 NULL_TREE, NULL_TREE);
4255 TREE_SIDE_EFFECTS (b) = 1;
4256 append_to_statement_list_force (body, &BIND_EXPR_BODY (b));
4261 pop_gimplify_context (body);
4263 #ifdef ENABLE_CHECKING
4264 walk_tree (body_p, check_pointer_types_r, NULL, NULL);
4267 timevar_pop (TV_TREE_GIMPLIFY);
4268 input_location = saved_location;
4271 /* Entry point to the gimplification pass. FNDECL is the FUNCTION_DECL
4272 node for the function we want to gimplify. */
4275 gimplify_function_tree (tree fndecl)
4279 oldfn = current_function_decl;
4280 current_function_decl = fndecl;
4282 gimplify_body (&DECL_SAVED_TREE (fndecl), fndecl);
4284 /* If we're instrumenting function entry/exit, then prepend the call to
4285 the entry hook and wrap the whole function in a TRY_FINALLY_EXPR to
4286 catch the exit hook. */
4287 /* ??? Add some way to ignore exceptions for this TFE. */
4288 if (flag_instrument_function_entry_exit
4289 && ! DECL_NO_INSTRUMENT_FUNCTION_ENTRY_EXIT (fndecl))
4293 tf = build (TRY_FINALLY_EXPR, void_type_node, NULL, NULL);
4294 TREE_SIDE_EFFECTS (tf) = 1;
4295 x = DECL_SAVED_TREE (fndecl);
4296 append_to_statement_list (x, &TREE_OPERAND (tf, 0));
4297 x = implicit_built_in_decls[BUILT_IN_PROFILE_FUNC_EXIT];
4298 x = build_function_call_expr (x, NULL);
4299 append_to_statement_list (x, &TREE_OPERAND (tf, 1));
4301 bind = build (BIND_EXPR, void_type_node, NULL, NULL, NULL);
4302 TREE_SIDE_EFFECTS (bind) = 1;
4303 x = implicit_built_in_decls[BUILT_IN_PROFILE_FUNC_ENTER];
4304 x = build_function_call_expr (x, NULL);
4305 append_to_statement_list (x, &BIND_EXPR_BODY (bind));
4306 append_to_statement_list (tf, &BIND_EXPR_BODY (bind));
4308 DECL_SAVED_TREE (fndecl) = bind;
4311 current_function_decl = oldfn;
4315 /* Expands EXPR to list of gimple statements STMTS. If SIMPLE is true,
4316 force the result to be either ssa_name or an invariant, otherwise
4317 just force it to be a rhs expression. If VAR is not NULL, make the
4318 base variable of the final destination be VAR if suitable. */
4321 force_gimple_operand (tree expr, tree *stmts, bool simple, tree var)
4324 enum gimplify_status ret;
4325 gimple_predicate gimple_test_f;
4329 if (is_gimple_val (expr))
4332 gimple_test_f = simple ? is_gimple_val : is_gimple_reg_rhs;
4334 push_gimplify_context ();
4335 gimplify_ctxp->into_ssa = true;
4338 expr = build (MODIFY_EXPR, TREE_TYPE (var), var, expr);
4340 ret = gimplify_expr (&expr, stmts, NULL,
4341 gimple_test_f, fb_rvalue);
4342 gcc_assert (ret != GS_ERROR);
4344 for (t = gimplify_ctxp->temps; t ; t = TREE_CHAIN (t))
4345 add_referenced_tmp_var (t);
4347 pop_gimplify_context (NULL);
4352 #include "gt-gimplify.h"