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);
79 /* Return a hash value for a formal temporary table entry. */
82 gimple_tree_hash (const void *p)
84 tree t = ((const elt_t *) p)->val;
85 return iterative_hash_expr (t, 0);
88 /* Compare two formal temporary table entries. */
91 gimple_tree_eq (const void *p1, const void *p2)
93 tree t1 = ((const elt_t *) p1)->val;
94 tree t2 = ((const elt_t *) p2)->val;
95 enum tree_code code = TREE_CODE (t1);
97 if (TREE_CODE (t2) != code
98 || TREE_TYPE (t1) != TREE_TYPE (t2))
101 if (!operand_equal_p (t1, t2, 0))
104 /* Only allow them to compare equal if they also hash equal; otherwise
105 results are nondeterminate, and we fail bootstrap comparison. */
106 if (gimple_tree_hash (p1) != gimple_tree_hash (p2))
112 /* Set up a context for the gimplifier. */
115 push_gimplify_context (void)
120 = (struct gimplify_ctx *) xcalloc (1, sizeof (struct gimplify_ctx));
122 gimplify_ctxp->temp_htab
123 = htab_create (1000, gimple_tree_hash, gimple_tree_eq, free);
125 gimplify_ctxp->temp_htab = NULL;
128 /* Tear down a context for the gimplifier. If BODY is non-null, then
129 put the temporaries into the outer BIND_EXPR. Otherwise, put them
130 in the unexpanded_var_list. */
133 pop_gimplify_context (tree body)
137 if (!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 ++(gimplify_ctxp->conditions);
197 /* Note that we've left a COND_EXPR. If we're back at unconditional scope
198 now, add any conditional cleanups we've seen to the prequeue. */
201 gimple_pop_condition (tree *pre_p)
203 int conds = --(gimplify_ctxp->conditions);
207 append_to_statement_list (gimplify_ctxp->conditional_cleanups, pre_p);
208 gimplify_ctxp->conditional_cleanups = NULL_TREE;
214 /* A subroutine of append_to_statement_list{,_force}. */
217 append_to_statement_list_1 (tree t, tree *list_p, bool side_effects)
220 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 append_to_statement_list_1 (t, list_p, t ? TREE_SIDE_EFFECTS (t) : false);
248 /* Similar, but the statement is always added, regardless of side effects. */
251 append_to_statement_list_force (tree t, tree *list_p)
253 append_to_statement_list_1 (t, list_p, t != NULL);
256 /* Both gimplify the statement T and append it to LIST_P. */
259 gimplify_and_add (tree t, tree *list_p)
262 append_to_statement_list (t, list_p);
265 /* Strip off a legitimate source ending from the input string NAME of
266 length LEN. Rather than having to know the names used by all of
267 our front ends, we strip off an ending of a period followed by
268 up to five characters. (Java uses ".class".) */
271 remove_suffix (char *name, int len)
275 for (i = 2; i < 8 && len > i; i++)
277 if (name[len - i] == '.')
279 name[len - i] = '\0';
285 /* Create a nameless artificial label and put it in the current function
286 context. Returns the newly created label. */
289 create_artificial_label (void)
291 tree lab = build_decl (LABEL_DECL, NULL_TREE, void_type_node);
293 DECL_ARTIFICIAL (lab) = 1;
294 DECL_CONTEXT (lab) = current_function_decl;
298 /* Create a new temporary name with PREFIX. Returns an identifier. */
300 static GTY(()) unsigned int tmp_var_id_num;
303 create_tmp_var_name (const char *prefix)
309 char *preftmp = ASTRDUP (prefix);
311 remove_suffix (preftmp, strlen (preftmp));
315 ASM_FORMAT_PRIVATE_NAME (tmp_name, prefix ? prefix : "T", tmp_var_id_num++);
316 return get_identifier (tmp_name);
320 /* Create a new temporary variable declaration of type TYPE.
321 Does NOT push it into the current binding. */
324 create_tmp_var_raw (tree type, const char *prefix)
329 /* Make the type of the variable writable. */
330 new_type = build_type_variant (type, 0, 0);
331 TYPE_ATTRIBUTES (new_type) = TYPE_ATTRIBUTES (type);
333 tmp_var = build_decl (VAR_DECL, create_tmp_var_name (prefix), type);
335 /* The variable was declared by the compiler. */
336 DECL_ARTIFICIAL (tmp_var) = 1;
337 /* And we don't want debug info for it. */
338 DECL_IGNORED_P (tmp_var) = 1;
340 /* Make the variable writable. */
341 TREE_READONLY (tmp_var) = 0;
343 DECL_EXTERNAL (tmp_var) = 0;
344 TREE_STATIC (tmp_var) = 0;
345 TREE_USED (tmp_var) = 1;
350 /* Create a new temporary variable declaration of type TYPE. DOES push the
351 variable into the current binding. Further, assume that this is called
352 only from gimplification or optimization, at which point the creation of
353 certain types are bugs. */
356 create_tmp_var (tree type, const char *prefix)
360 #if defined ENABLE_CHECKING
361 /* We don't allow types that are addressable (meaning we can't make copies),
362 incomplete, or of variable size. */
363 if (TREE_ADDRESSABLE (type)
364 || !COMPLETE_TYPE_P (type)
365 || 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 if (TREE_CODE (scope) != BIND_EXPR)
523 temps = nreverse (last);
524 TREE_CHAIN (last) = BIND_EXPR_VARS (scope);
525 BIND_EXPR_VARS (scope) = temps;
530 gimple_add_tmp_var (tree tmp)
532 if (TREE_CHAIN (tmp) || DECL_SEEN_IN_BIND_EXPR_P (tmp))
535 DECL_CONTEXT (tmp) = current_function_decl;
536 DECL_SEEN_IN_BIND_EXPR_P (tmp) = 1;
540 TREE_CHAIN (tmp) = gimplify_ctxp->temps;
541 gimplify_ctxp->temps = tmp;
546 declare_tmp_vars (tmp, DECL_SAVED_TREE (current_function_decl));
549 /* Determines whether to assign a locus to the statement STMT. */
552 should_carry_locus_p (tree stmt)
554 /* Don't emit a line note for a label. We particularly don't want to
555 emit one for the break label, since it doesn't actually correspond
556 to the beginning of the loop/switch. */
557 if (TREE_CODE (stmt) == LABEL_EXPR)
560 /* Do not annotate empty statements, since it confuses gcov. */
561 if (!TREE_SIDE_EFFECTS (stmt))
568 annotate_one_with_locus (tree t, location_t locus)
570 if (IS_EXPR_CODE_CLASS (TREE_CODE_CLASS (TREE_CODE (t)))
571 && ! EXPR_HAS_LOCATION (t)
572 && should_carry_locus_p (t))
573 SET_EXPR_LOCATION (t, locus);
577 annotate_all_with_locus (tree *stmt_p, location_t locus)
579 tree_stmt_iterator i;
584 for (i = tsi_start (*stmt_p); !tsi_end_p (i); tsi_next (&i))
586 tree t = tsi_stmt (i);
588 #ifdef ENABLE_CHECKING
589 /* Assuming we've already been gimplified, we shouldn't
590 see nested chaining constructs anymore. */
591 if (TREE_CODE (t) == STATEMENT_LIST
592 || TREE_CODE (t) == COMPOUND_EXPR)
596 annotate_one_with_locus (t, locus);
600 /* Similar to copy_tree_r() but do not copy SAVE_EXPR or TARGET_EXPR nodes.
601 These nodes model computations that should only be done once. If we
602 were to unshare something like SAVE_EXPR(i++), the gimplification
603 process would create wrong code. */
606 mostly_copy_tree_r (tree *tp, int *walk_subtrees, void *data)
608 enum tree_code code = TREE_CODE (*tp);
609 /* Don't unshare types, decls, constants and SAVE_EXPR nodes. */
610 if (TREE_CODE_CLASS (code) == 't'
611 || TREE_CODE_CLASS (code) == 'd'
612 || TREE_CODE_CLASS (code) == 'c'
613 || code == SAVE_EXPR || code == TARGET_EXPR
614 /* We can't do anything sensible with a BLOCK used as an expression,
615 but we also can't abort when we see it because of non-expression
616 uses. So just avert our eyes and cross our fingers. Silly Java. */
619 else if (code == BIND_EXPR)
622 copy_tree_r (tp, walk_subtrees, data);
627 /* Callback for walk_tree to unshare most of the shared trees rooted at
628 *TP. If *TP has been visited already (i.e., TREE_VISITED (*TP) == 1),
629 then *TP is deep copied by calling copy_tree_r.
631 This unshares the same trees as copy_tree_r with the exception of
632 SAVE_EXPR nodes. These nodes model computations that should only be
633 done once. If we were to unshare something like SAVE_EXPR(i++), the
634 gimplification process would create wrong code. */
637 copy_if_shared_r (tree *tp, int *walk_subtrees ATTRIBUTE_UNUSED,
638 void *data ATTRIBUTE_UNUSED)
641 enum tree_code code = TREE_CODE (t);
643 /* Skip types, decls, and constants. But we do want to look at their
644 types and the bounds of types. Mark them as visited so we properly
645 unmark their subtrees on the unmark pass. If we've already seen them,
646 don't look down further. */
647 if (TREE_CODE_CLASS (code) == 't'
648 || TREE_CODE_CLASS (code) == 'd'
649 || TREE_CODE_CLASS (code) == 'c')
651 if (TREE_VISITED (t))
654 TREE_VISITED (t) = 1;
657 /* If this node has been visited already, unshare it and don't look
659 else if (TREE_VISITED (t))
661 walk_tree (tp, mostly_copy_tree_r, NULL, NULL);
665 /* Otherwise, mark the tree as visited and keep looking. */
667 TREE_VISITED (t) = 1;
673 unmark_visited_r (tree *tp, int *walk_subtrees ATTRIBUTE_UNUSED,
674 void *data ATTRIBUTE_UNUSED)
676 if (TREE_VISITED (*tp))
677 TREE_VISITED (*tp) = 0;
684 /* Unshare all the trees in BODY_P, a pointer into the body of FNDECL, and the
685 bodies of any nested functions if we are unsharing the entire body of
689 unshare_body (tree *body_p, tree fndecl)
691 struct cgraph_node *cgn = cgraph_node (fndecl);
693 walk_tree (body_p, copy_if_shared_r, NULL, NULL);
694 if (body_p == &DECL_SAVED_TREE (fndecl))
695 for (cgn = cgn->nested; cgn; cgn = cgn->next_nested)
696 unshare_body (&DECL_SAVED_TREE (cgn->decl), cgn->decl);
699 /* Likewise, but mark all trees as not visited. */
702 unvisit_body (tree *body_p, tree fndecl)
704 struct cgraph_node *cgn = cgraph_node (fndecl);
706 walk_tree (body_p, unmark_visited_r, NULL, NULL);
707 if (body_p == &DECL_SAVED_TREE (fndecl))
708 for (cgn = cgn->nested; cgn; cgn = cgn->next_nested)
709 unvisit_body (&DECL_SAVED_TREE (cgn->decl), cgn->decl);
712 /* Unshare T and all the trees reached from T via TREE_CHAIN. */
715 unshare_all_trees (tree t)
717 walk_tree (&t, copy_if_shared_r, NULL, NULL);
718 walk_tree (&t, unmark_visited_r, NULL, NULL);
721 /* Unconditionally make an unshared copy of EXPR. This is used when using
722 stored expressions which span multiple functions, such as BINFO_VTABLE,
723 as the normal unsharing process can't tell that they're shared. */
726 unshare_expr (tree expr)
728 walk_tree (&expr, mostly_copy_tree_r, NULL, NULL);
732 /* A terser interface for building a representation of a exception
736 gimple_build_eh_filter (tree body, tree allowed, tree failure)
740 /* FIXME should the allowed types go in TREE_TYPE? */
741 t = build (EH_FILTER_EXPR, void_type_node, allowed, NULL_TREE);
742 append_to_statement_list (failure, &EH_FILTER_FAILURE (t));
744 t = build (TRY_CATCH_EXPR, void_type_node, NULL_TREE, t);
745 append_to_statement_list (body, &TREE_OPERAND (t, 0));
751 /* WRAPPER is a code such as BIND_EXPR or CLEANUP_POINT_EXPR which can both
752 contain statements and have a value. Assign its value to a temporary
753 and give it void_type_node. Returns the temporary, or NULL_TREE if
754 WRAPPER was already void. */
757 voidify_wrapper_expr (tree wrapper, tree temp)
759 if (!VOID_TYPE_P (TREE_TYPE (wrapper)))
761 tree *p, sub = wrapper;
764 /* Set p to point to the body of the wrapper. */
765 switch (TREE_CODE (sub))
768 /* For a BIND_EXPR, the body is operand 1. */
769 p = &BIND_EXPR_BODY (sub);
773 p = &TREE_OPERAND (sub, 0);
777 /* Advance to the last statement. Set all container types to void. */
778 if (TREE_CODE (*p) == STATEMENT_LIST)
780 tree_stmt_iterator i = tsi_last (*p);
781 p = tsi_end_p (i) ? NULL : tsi_stmt_ptr (i);
785 for (; TREE_CODE (*p) == COMPOUND_EXPR; p = &TREE_OPERAND (*p, 1))
787 TREE_SIDE_EFFECTS (*p) = 1;
788 TREE_TYPE (*p) = void_type_node;
792 if (p == NULL || IS_EMPTY_STMT (*p))
794 /* Look through exception handling. */
795 else if (TREE_CODE (*p) == TRY_FINALLY_EXPR
796 || TREE_CODE (*p) == TRY_CATCH_EXPR)
801 /* The C++ frontend already did this for us. */
802 else if (TREE_CODE (*p) == INIT_EXPR
803 || TREE_CODE (*p) == TARGET_EXPR)
804 temp = TREE_OPERAND (*p, 0);
805 /* If we're returning a dereference, move the dereference
806 outside the wrapper. */
807 else if (TREE_CODE (*p) == INDIRECT_REF)
809 tree ptr = TREE_OPERAND (*p, 0);
810 temp = create_tmp_var (TREE_TYPE (ptr), "retval");
811 *p = build (MODIFY_EXPR, TREE_TYPE (ptr), temp, ptr);
812 temp = build1 (INDIRECT_REF, TREE_TYPE (TREE_TYPE (temp)), temp);
813 /* If this is a BIND_EXPR for a const inline function, it might not
814 have TREE_SIDE_EFFECTS set. That is no longer accurate. */
815 TREE_SIDE_EFFECTS (wrapper) = 1;
820 temp = create_tmp_var (TREE_TYPE (wrapper), "retval");
821 *p = build (MODIFY_EXPR, TREE_TYPE (temp), temp, *p);
822 TREE_SIDE_EFFECTS (wrapper) = 1;
825 TREE_TYPE (wrapper) = void_type_node;
832 /* Prepare calls to builtins to SAVE and RESTORE the stack as well as
833 a temporary through which they communicate. */
836 build_stack_save_restore (tree *save, tree *restore)
838 tree save_call, tmp_var;
841 build_function_call_expr (implicit_built_in_decls[BUILT_IN_STACK_SAVE],
843 tmp_var = create_tmp_var (ptr_type_node, "saved_stack");
845 *save = build (MODIFY_EXPR, ptr_type_node, tmp_var, save_call);
847 build_function_call_expr (implicit_built_in_decls[BUILT_IN_STACK_RESTORE],
848 tree_cons (NULL_TREE, tmp_var, NULL_TREE));
851 /* Gimplify a BIND_EXPR. Just voidify and recurse. */
853 static enum gimplify_status
854 gimplify_bind_expr (tree *expr_p, tree temp, tree *pre_p)
856 tree bind_expr = *expr_p;
857 bool old_save_stack = gimplify_ctxp->save_stack;
860 temp = voidify_wrapper_expr (bind_expr, temp);
862 /* Mark variables seen in this bind expr. */
863 for (t = BIND_EXPR_VARS (bind_expr); t ; t = TREE_CHAIN (t))
864 DECL_SEEN_IN_BIND_EXPR_P (t) = 1;
866 gimple_push_bind_expr (bind_expr);
867 gimplify_ctxp->save_stack = false;
869 gimplify_to_stmt_list (&BIND_EXPR_BODY (bind_expr));
871 if (gimplify_ctxp->save_stack)
873 tree stack_save, stack_restore;
875 /* Save stack on entry and restore it on exit. Add a try_finally
876 block to achieve this. Note that mudflap depends on the
877 format of the emitted code: see mx_register_decls(). */
878 build_stack_save_restore (&stack_save, &stack_restore);
880 t = build (TRY_FINALLY_EXPR, void_type_node,
881 BIND_EXPR_BODY (bind_expr), NULL_TREE);
882 append_to_statement_list (stack_restore, &TREE_OPERAND (t, 1));
884 BIND_EXPR_BODY (bind_expr) = NULL_TREE;
885 append_to_statement_list (stack_save, &BIND_EXPR_BODY (bind_expr));
886 append_to_statement_list (t, &BIND_EXPR_BODY (bind_expr));
889 gimplify_ctxp->save_stack = old_save_stack;
890 gimple_pop_bind_expr ();
895 append_to_statement_list (bind_expr, pre_p);
902 /* Gimplify a RETURN_EXPR. If the expression to be returned is not a
903 GIMPLE value, it is assigned to a new temporary and the statement is
904 re-written to return the temporary.
906 PRE_P points to the list where side effects that must happen before
907 STMT should be stored. */
909 static enum gimplify_status
910 gimplify_return_expr (tree stmt, tree *pre_p)
912 tree ret_expr = TREE_OPERAND (stmt, 0);
913 tree result_decl, result;
915 if (!ret_expr || TREE_CODE (ret_expr) == RESULT_DECL
916 || ret_expr == error_mark_node)
919 if (VOID_TYPE_P (TREE_TYPE (TREE_TYPE (current_function_decl))))
920 result_decl = NULL_TREE;
923 result_decl = TREE_OPERAND (ret_expr, 0);
924 if (TREE_CODE (result_decl) == INDIRECT_REF)
925 /* See through a return by reference. */
926 result_decl = TREE_OPERAND (result_decl, 0);
927 #ifdef ENABLE_CHECKING
928 if ((TREE_CODE (ret_expr) != MODIFY_EXPR
929 && TREE_CODE (ret_expr) != INIT_EXPR)
930 || TREE_CODE (result_decl) != RESULT_DECL)
935 /* If aggregate_value_p is true, then we can return the bare RESULT_DECL.
936 Recall that aggregate_value_p is FALSE for any aggregate type that is
937 returned in registers. If we're returning values in registers, then
938 we don't want to extend the lifetime of the RESULT_DECL, particularly
939 across another call. In addition, for those aggregates for which
940 hard_function_value generates a PARALLEL, we'll abort during normal
941 expansion of structure assignments; there's special code in expand_return
942 to handle this case that does not exist in expand_expr. */
944 || aggregate_value_p (result_decl, TREE_TYPE (current_function_decl)))
945 result = result_decl;
946 else if (gimplify_ctxp->return_temp)
947 result = gimplify_ctxp->return_temp;
950 result = create_tmp_var (TREE_TYPE (result_decl), NULL);
952 /* ??? With complex control flow (usually involving abnormal edges),
953 we can wind up warning about an uninitialized value for this. Due
954 to how this variable is constructed and initialized, this is never
955 true. Give up and never warn. */
956 TREE_NO_WARNING (result) = 1;
958 gimplify_ctxp->return_temp = result;
961 /* Smash the lhs of the MODIFY_EXPR to the temporary we plan to use.
962 Then gimplify the whole thing. */
963 if (result != result_decl)
964 TREE_OPERAND (ret_expr, 0) = result;
966 gimplify_and_add (TREE_OPERAND (stmt, 0), pre_p);
968 /* If we didn't use a temporary, then the result is just the result_decl.
969 Otherwise we need a simple copy. This should already be gimple. */
970 if (result == result_decl)
973 ret_expr = build (MODIFY_EXPR, TREE_TYPE (result), result_decl, result);
974 TREE_OPERAND (stmt, 0) = ret_expr;
979 /* Gimplifies a DECL_EXPR node *STMT_P by making any necessary allocation
980 and initialization explicit. */
982 static enum gimplify_status
983 gimplify_decl_expr (tree *stmt_p)
986 tree decl = DECL_EXPR_DECL (stmt);
990 if (TREE_TYPE (decl) == error_mark_node)
993 else if (TREE_CODE (decl) == TYPE_DECL)
994 gimplify_type_sizes (TREE_TYPE (decl), stmt_p);
996 else if (TREE_CODE (decl) == VAR_DECL && !DECL_EXTERNAL (decl))
998 tree init = DECL_INITIAL (decl);
1000 if (!TREE_CONSTANT (DECL_SIZE (decl)))
1002 /* This is a variable-sized decl. Simplify its size and mark it
1003 for deferred expansion. Note that mudflap depends on the format
1004 of the emitted code: see mx_register_decls(). */
1005 tree t, args, addr, ptr_type;
1007 gimplify_type_sizes (TREE_TYPE (decl), stmt_p);
1008 gimplify_one_sizepos (&DECL_SIZE (decl), stmt_p);
1009 gimplify_one_sizepos (&DECL_SIZE_UNIT (decl), stmt_p);
1011 /* All occurrences of this decl in final gimplified code will be
1012 replaced by indirection. Setting DECL_VALUE_EXPR does two
1013 things: First, it lets the rest of the gimplifier know what
1014 replacement to use. Second, it lets the debug info know
1015 where to find the value. */
1016 ptr_type = build_pointer_type (TREE_TYPE (decl));
1017 addr = create_tmp_var (ptr_type, get_name (decl));
1018 DECL_IGNORED_P (addr) = 0;
1019 t = build_fold_indirect_ref (addr);
1020 DECL_VALUE_EXPR (decl) = t;
1022 args = tree_cons (NULL, DECL_SIZE_UNIT (decl), NULL);
1023 t = built_in_decls[BUILT_IN_ALLOCA];
1024 t = build_function_call_expr (t, args);
1025 t = fold_convert (ptr_type, t);
1026 t = build2 (MODIFY_EXPR, void_type_node, addr, t);
1028 gimplify_and_add (t, stmt_p);
1030 /* Indicate that we need to restore the stack level when the
1031 enclosing BIND_EXPR is exited. */
1032 gimplify_ctxp->save_stack = true;
1035 if (init && init != error_mark_node)
1037 if (!TREE_STATIC (decl))
1039 DECL_INITIAL (decl) = NULL_TREE;
1040 init = build (MODIFY_EXPR, void_type_node, decl, init);
1041 gimplify_and_add (init, stmt_p);
1044 /* We must still examine initializers for static variables
1045 as they may contain a label address. */
1046 walk_tree (&init, force_labels_r, NULL, NULL);
1049 /* This decl isn't mentioned in the enclosing block, so add it to the
1050 list of temps. FIXME it seems a bit of a kludge to say that
1051 anonymous artificial vars aren't pushed, but everything else is. */
1052 if (DECL_ARTIFICIAL (decl) && DECL_NAME (decl) == NULL_TREE)
1053 gimple_add_tmp_var (decl);
1059 /* Gimplify a LOOP_EXPR. Normally this just involves gimplifying the body
1060 and replacing the LOOP_EXPR with goto, but if the loop contains an
1061 EXIT_EXPR, we need to append a label for it to jump to. */
1063 static enum gimplify_status
1064 gimplify_loop_expr (tree *expr_p, tree *pre_p)
1066 tree saved_label = gimplify_ctxp->exit_label;
1067 tree start_label = build1 (LABEL_EXPR, void_type_node, NULL_TREE);
1068 tree jump_stmt = build_and_jump (&LABEL_EXPR_LABEL (start_label));
1070 append_to_statement_list (start_label, pre_p);
1072 gimplify_ctxp->exit_label = NULL_TREE;
1074 gimplify_and_add (LOOP_EXPR_BODY (*expr_p), pre_p);
1076 if (gimplify_ctxp->exit_label)
1078 append_to_statement_list (jump_stmt, pre_p);
1079 *expr_p = build1 (LABEL_EXPR, void_type_node, gimplify_ctxp->exit_label);
1082 *expr_p = jump_stmt;
1084 gimplify_ctxp->exit_label = saved_label;
1089 /* Compare two case labels. Because the front end should already have
1090 made sure that case ranges do not overlap, it is enough to only compare
1091 the CASE_LOW values of each case label. */
1094 compare_case_labels (const void *p1, const void *p2)
1096 tree case1 = *(tree *)p1;
1097 tree case2 = *(tree *)p2;
1099 return tree_int_cst_compare (CASE_LOW (case1), CASE_LOW (case2));
1102 /* Sort the case labels in LABEL_VEC in place in ascending order. */
1105 sort_case_labels (tree label_vec)
1107 size_t len = TREE_VEC_LENGTH (label_vec);
1108 tree default_case = TREE_VEC_ELT (label_vec, len - 1);
1110 if (CASE_LOW (default_case))
1114 /* The last label in the vector should be the default case
1116 for (i = 0; i < len; ++i)
1118 tree t = TREE_VEC_ELT (label_vec, i);
1122 TREE_VEC_ELT (label_vec, i) = TREE_VEC_ELT (label_vec, len - 1);
1123 TREE_VEC_ELT (label_vec, len - 1) = default_case;
1129 qsort (&TREE_VEC_ELT (label_vec, 0), len - 1, sizeof (tree),
1130 compare_case_labels);
1133 /* Gimplify a SWITCH_EXPR, and collect a TREE_VEC of the labels it can
1136 static enum gimplify_status
1137 gimplify_switch_expr (tree *expr_p, tree *pre_p)
1139 tree switch_expr = *expr_p;
1140 enum gimplify_status ret;
1142 ret = gimplify_expr (&SWITCH_COND (switch_expr), pre_p, NULL,
1143 is_gimple_val, fb_rvalue);
1145 if (SWITCH_BODY (switch_expr))
1147 varray_type labels, saved_labels;
1148 tree label_vec, default_case = NULL_TREE;
1151 /* If someone can be bothered to fill in the labels, they can
1152 be bothered to null out the body too. */
1153 if (SWITCH_LABELS (switch_expr))
1156 saved_labels = gimplify_ctxp->case_labels;
1157 VARRAY_TREE_INIT (gimplify_ctxp->case_labels, 8, "case_labels");
1159 gimplify_to_stmt_list (&SWITCH_BODY (switch_expr));
1161 labels = gimplify_ctxp->case_labels;
1162 gimplify_ctxp->case_labels = saved_labels;
1164 len = VARRAY_ACTIVE_SIZE (labels);
1166 for (i = 0; i < len; ++i)
1168 tree t = VARRAY_TREE (labels, i);
1171 /* The default case must be the last label in the list. */
1173 VARRAY_TREE (labels, i) = VARRAY_TREE (labels, len - 1);
1179 label_vec = make_tree_vec (len + 1);
1180 SWITCH_LABELS (*expr_p) = label_vec;
1181 append_to_statement_list (switch_expr, pre_p);
1185 /* If the switch has no default label, add one, so that we jump
1186 around the switch body. */
1187 default_case = build (CASE_LABEL_EXPR, void_type_node, NULL_TREE,
1188 NULL_TREE, create_artificial_label ());
1189 append_to_statement_list (SWITCH_BODY (switch_expr), pre_p);
1190 *expr_p = build (LABEL_EXPR, void_type_node,
1191 CASE_LABEL (default_case));
1194 *expr_p = SWITCH_BODY (switch_expr);
1196 for (i = 0; i < len; ++i)
1197 TREE_VEC_ELT (label_vec, i) = VARRAY_TREE (labels, i);
1198 TREE_VEC_ELT (label_vec, len) = default_case;
1200 sort_case_labels (label_vec);
1202 SWITCH_BODY (switch_expr) = NULL;
1204 else if (!SWITCH_LABELS (switch_expr))
1210 static enum gimplify_status
1211 gimplify_case_label_expr (tree *expr_p)
1213 tree expr = *expr_p;
1214 if (gimplify_ctxp->case_labels)
1215 VARRAY_PUSH_TREE (gimplify_ctxp->case_labels, expr);
1218 *expr_p = build (LABEL_EXPR, void_type_node, CASE_LABEL (expr));
1222 /* Gimplify a LABELED_BLOCK_EXPR into a LABEL_EXPR following
1223 a (possibly empty) body. */
1225 static enum gimplify_status
1226 gimplify_labeled_block_expr (tree *expr_p)
1228 tree body = LABELED_BLOCK_BODY (*expr_p);
1229 tree label = LABELED_BLOCK_LABEL (*expr_p);
1232 DECL_CONTEXT (label) = current_function_decl;
1233 t = build (LABEL_EXPR, void_type_node, label);
1234 if (body != NULL_TREE)
1235 t = build (COMPOUND_EXPR, void_type_node, body, t);
1241 /* Gimplify a EXIT_BLOCK_EXPR into a GOTO_EXPR. */
1243 static enum gimplify_status
1244 gimplify_exit_block_expr (tree *expr_p)
1246 tree labeled_block = TREE_OPERAND (*expr_p, 0);
1249 /* First operand must be a LABELED_BLOCK_EXPR, which should
1250 already be lowered (or partially lowered) when we get here. */
1251 #if defined ENABLE_CHECKING
1252 if (TREE_CODE (labeled_block) != LABELED_BLOCK_EXPR)
1256 label = LABELED_BLOCK_LABEL (labeled_block);
1257 *expr_p = build1 (GOTO_EXPR, void_type_node, label);
1262 /* Build a GOTO to the LABEL_DECL pointed to by LABEL_P, building it first
1266 build_and_jump (tree *label_p)
1268 if (label_p == NULL)
1269 /* If there's nowhere to jump, just fall through. */
1272 if (*label_p == NULL_TREE)
1274 tree label = create_artificial_label ();
1278 return build1 (GOTO_EXPR, void_type_node, *label_p);
1281 /* Gimplify an EXIT_EXPR by converting to a GOTO_EXPR inside a COND_EXPR.
1282 This also involves building a label to jump to and communicating it to
1283 gimplify_loop_expr through gimplify_ctxp->exit_label. */
1285 static enum gimplify_status
1286 gimplify_exit_expr (tree *expr_p)
1288 tree cond = TREE_OPERAND (*expr_p, 0);
1291 expr = build_and_jump (&gimplify_ctxp->exit_label);
1292 expr = build (COND_EXPR, void_type_node, cond, expr, NULL_TREE);
1298 /* A helper function to be called via walk_tree. Mark all labels under *TP
1299 as being forced. To be called for DECL_INITIAL of static variables. */
1302 force_labels_r (tree *tp, int *walk_subtrees, void *data ATTRIBUTE_UNUSED)
1306 if (TREE_CODE (*tp) == LABEL_DECL)
1307 FORCED_LABEL (*tp) = 1;
1312 /* *EXPR_P is a COMPONENT_REF being used as an rvalue. If its type is
1313 different from its canonical type, wrap the whole thing inside a
1314 NOP_EXPR and force the type of the COMPONENT_REF to be the canonical
1317 The canonical type of a COMPONENT_REF is the type of the field being
1318 referenced--unless the field is a bit-field which can be read directly
1319 in a smaller mode, in which case the canonical type is the
1320 sign-appropriate type corresponding to that mode. */
1323 canonicalize_component_ref (tree *expr_p)
1325 tree expr = *expr_p;
1328 if (TREE_CODE (expr) != COMPONENT_REF)
1331 if (INTEGRAL_TYPE_P (TREE_TYPE (expr)))
1332 type = TREE_TYPE (get_unwidened (expr, NULL_TREE));
1334 type = TREE_TYPE (TREE_OPERAND (expr, 1));
1336 if (TREE_TYPE (expr) != type)
1338 tree old_type = TREE_TYPE (expr);
1340 /* Set the type of the COMPONENT_REF to the underlying type. */
1341 TREE_TYPE (expr) = type;
1343 /* And wrap the whole thing inside a NOP_EXPR. */
1344 expr = build1 (NOP_EXPR, old_type, expr);
1350 /* If a NOP conversion is changing a pointer to array of foo to a pointer
1351 to foo, embed that change in the ADDR_EXPR by converting
1356 where L is the lower bound. For simplicity, only do this for constant
1360 canonicalize_addr_expr (tree *expr_p)
1362 tree expr = *expr_p;
1363 tree ctype = TREE_TYPE (expr);
1364 tree addr_expr = TREE_OPERAND (expr, 0);
1365 tree atype = TREE_TYPE (addr_expr);
1366 tree dctype, datype, ddatype, otype, obj_expr;
1368 /* Both cast and addr_expr types should be pointers. */
1369 if (!POINTER_TYPE_P (ctype) || !POINTER_TYPE_P (atype))
1372 /* The addr_expr type should be a pointer to an array. */
1373 datype = TREE_TYPE (atype);
1374 if (TREE_CODE (datype) != ARRAY_TYPE)
1377 /* Both cast and addr_expr types should address the same object type. */
1378 dctype = TREE_TYPE (ctype);
1379 ddatype = TREE_TYPE (datype);
1380 if (!lang_hooks.types_compatible_p (ddatype, dctype))
1383 /* The addr_expr and the object type should match. */
1384 obj_expr = TREE_OPERAND (addr_expr, 0);
1385 otype = TREE_TYPE (obj_expr);
1386 if (!lang_hooks.types_compatible_p (otype, datype))
1389 /* The lower bound and element sizes must be constant. */
1390 if (TREE_CODE (TYPE_SIZE_UNIT (dctype)) != INTEGER_CST
1391 || !TYPE_DOMAIN (datype) || !TYPE_MIN_VALUE (TYPE_DOMAIN (datype))
1392 || TREE_CODE (TYPE_MIN_VALUE (TYPE_DOMAIN (datype))) != INTEGER_CST)
1395 /* All checks succeeded. Build a new node to merge the cast. */
1396 *expr_p = build4 (ARRAY_REF, dctype, obj_expr,
1397 TYPE_MIN_VALUE (TYPE_DOMAIN (datype)),
1398 TYPE_MIN_VALUE (TYPE_DOMAIN (datype)),
1399 size_binop (EXACT_DIV_EXPR, TYPE_SIZE_UNIT (dctype),
1400 size_int (TYPE_ALIGN_UNIT (dctype))));
1401 *expr_p = build1 (ADDR_EXPR, ctype, *expr_p);
1404 /* *EXPR_P is a NOP_EXPR or CONVERT_EXPR. Remove it and/or other conversions
1405 underneath as appropriate. */
1407 static enum gimplify_status
1408 gimplify_conversion (tree *expr_p)
1410 /* If we still have a conversion at the toplevel, then strip
1411 away all but the outermost conversion. */
1412 if (TREE_CODE (*expr_p) == NOP_EXPR || TREE_CODE (*expr_p) == CONVERT_EXPR)
1414 STRIP_SIGN_NOPS (TREE_OPERAND (*expr_p, 0));
1416 /* And remove the outermost conversion if it's useless. */
1417 if (tree_ssa_useless_type_conversion (*expr_p))
1418 *expr_p = TREE_OPERAND (*expr_p, 0);
1421 /* If we still have a conversion at the toplevel,
1422 then canonicalize some constructs. */
1423 if (TREE_CODE (*expr_p) == NOP_EXPR || TREE_CODE (*expr_p) == CONVERT_EXPR)
1425 tree sub = TREE_OPERAND (*expr_p, 0);
1427 /* If a NOP conversion is changing the type of a COMPONENT_REF
1428 expression, then canonicalize its type now in order to expose more
1429 redundant conversions. */
1430 if (TREE_CODE (sub) == COMPONENT_REF)
1431 canonicalize_component_ref (&TREE_OPERAND (*expr_p, 0));
1433 /* If a NOP conversion is changing a pointer to array of foo
1434 to a pointer to foo, embed that change in the ADDR_EXPR. */
1435 else if (TREE_CODE (sub) == ADDR_EXPR)
1436 canonicalize_addr_expr (expr_p);
1442 /* Gimplify the COMPONENT_REF, ARRAY_REF, REALPART_EXPR or IMAGPART_EXPR
1443 node pointed by EXPR_P.
1446 : min_lval '[' val ']'
1448 | compound_lval '[' val ']'
1449 | compound_lval '.' ID
1451 This is not part of the original SIMPLE definition, which separates
1452 array and member references, but it seems reasonable to handle them
1453 together. Also, this way we don't run into problems with union
1454 aliasing; gcc requires that for accesses through a union to alias, the
1455 union reference must be explicit, which was not always the case when we
1456 were splitting up array and member refs.
1458 PRE_P points to the list where side effects that must happen before
1459 *EXPR_P should be stored.
1461 POST_P points to the list where side effects that must happen after
1462 *EXPR_P should be stored. */
1464 static enum gimplify_status
1465 gimplify_compound_lval (tree *expr_p, tree *pre_p,
1466 tree *post_p, fallback_t fallback)
1470 enum gimplify_status ret = GS_OK, tret;
1473 /* Create a stack of the subexpressions so later we can walk them in
1474 order from inner to outer.
1476 This array is very memory consuming. Don't even think of making
1478 VARRAY_GENERIC_PTR_NOGC_INIT (stack, 10, "stack");
1480 /* We can either handle REALPART_EXPR, IMAGEPART_EXPR anything that
1481 handled_components can deal with. */
1483 (handled_component_p (*p)
1484 || TREE_CODE (*p) == REALPART_EXPR || TREE_CODE (*p) == IMAGPART_EXPR);
1485 p = &TREE_OPERAND (*p, 0))
1486 VARRAY_PUSH_GENERIC_PTR_NOGC (stack, *p);
1488 #if defined ENABLE_CHECKING
1489 if (VARRAY_ACTIVE_SIZE (stack) == 0)
1493 /* Now STACK is a stack of pointers to all the refs we've walked through
1494 and P points to the innermost expression.
1496 Java requires that we elaborated nodes in source order. That
1497 means we must gimplify the inner expression followed by each of
1498 the indices, in order. But we can't gimplify the inner
1499 expression until we deal with any variable bounds, sizes, or
1500 positions in order to deal with PLACEHOLDER_EXPRs.
1502 So we do this in three steps. First we deal with the annotations
1503 for any variables in the components, then we gimplify the base,
1504 then we gimplify any indices, from left to right. */
1505 for (i = VARRAY_ACTIVE_SIZE (stack) - 1; i >= 0; i--)
1507 tree t = VARRAY_GENERIC_PTR_NOGC (stack, i);
1509 if (TREE_CODE (t) == ARRAY_REF || TREE_CODE (t) == ARRAY_RANGE_REF)
1511 /* Gimplify the low bound and element type size and put them into
1512 the ARRAY_REF. If these values are set, they have already been
1514 if (!TREE_OPERAND (t, 2))
1516 tree low = unshare_expr (array_ref_low_bound (t));
1517 if (!is_gimple_min_invariant (low))
1519 TREE_OPERAND (t, 2) = low;
1520 tret = gimplify_expr (&TREE_OPERAND (t, 2), pre_p, post_p,
1521 is_gimple_formal_tmp_reg, fb_rvalue);
1522 ret = MIN (ret, tret);
1526 if (!TREE_OPERAND (t, 3))
1528 tree elmt_type = TREE_TYPE (TREE_TYPE (TREE_OPERAND (t, 0)));
1529 tree elmt_size = unshare_expr (array_ref_element_size (t));
1530 tree factor = size_int (TYPE_ALIGN_UNIT (elmt_type));
1532 /* Divide the element size by the alignment of the element
1534 elmt_size = size_binop (EXACT_DIV_EXPR, elmt_size, factor);
1536 if (!is_gimple_min_invariant (elmt_size))
1538 TREE_OPERAND (t, 3) = elmt_size;
1539 tret = gimplify_expr (&TREE_OPERAND (t, 3), pre_p, post_p,
1540 is_gimple_formal_tmp_reg, fb_rvalue);
1541 ret = MIN (ret, tret);
1545 else if (TREE_CODE (t) == COMPONENT_REF)
1547 /* Set the field offset into T and gimplify it. */
1548 if (!TREE_OPERAND (t, 2))
1550 tree offset = unshare_expr (component_ref_field_offset (t));
1551 tree field = TREE_OPERAND (t, 1);
1553 = size_int (DECL_OFFSET_ALIGN (field) / BITS_PER_UNIT);
1555 /* Divide the offset by its alignment. */
1556 offset = size_binop (EXACT_DIV_EXPR, offset, factor);
1558 if (!is_gimple_min_invariant (offset))
1560 TREE_OPERAND (t, 2) = offset;
1561 tret = gimplify_expr (&TREE_OPERAND (t, 2), pre_p, post_p,
1562 is_gimple_formal_tmp_reg, fb_rvalue);
1563 ret = MIN (ret, tret);
1569 /* Step 2 is to gimplify the base expression. */
1570 tret = gimplify_expr (p, pre_p, post_p, is_gimple_min_lval, fallback);
1571 ret = MIN (ret, tret);
1573 /* And finally, the indices and operands to BIT_FIELD_REF. During this
1574 loop we also remove any useless conversions. */
1575 for (; VARRAY_ACTIVE_SIZE (stack) > 0; )
1577 tree t = VARRAY_TOP_TREE (stack);
1579 if (TREE_CODE (t) == ARRAY_REF || TREE_CODE (t) == ARRAY_RANGE_REF)
1581 /* Gimplify the dimension.
1582 Temporary fix for gcc.c-torture/execute/20040313-1.c.
1583 Gimplify non-constant array indices into a temporary
1585 FIXME - The real fix is to gimplify post-modify
1586 expressions into a minimal gimple lvalue. However, that
1587 exposes bugs in alias analysis. The alias analyzer does
1588 not handle &PTR->FIELD very well. Will fix after the
1589 branch is merged into mainline (dnovillo 2004-05-03). */
1590 if (!is_gimple_min_invariant (TREE_OPERAND (t, 1)))
1592 tret = gimplify_expr (&TREE_OPERAND (t, 1), pre_p, post_p,
1593 is_gimple_formal_tmp_reg, fb_rvalue);
1594 ret = MIN (ret, tret);
1597 else if (TREE_CODE (t) == BIT_FIELD_REF)
1599 tret = gimplify_expr (&TREE_OPERAND (t, 1), pre_p, post_p,
1600 is_gimple_val, fb_rvalue);
1601 ret = MIN (ret, tret);
1602 tret = gimplify_expr (&TREE_OPERAND (t, 2), pre_p, post_p,
1603 is_gimple_val, fb_rvalue);
1604 ret = MIN (ret, tret);
1607 STRIP_USELESS_TYPE_CONVERSION (TREE_OPERAND (t, 0));
1609 /* The innermost expression P may have originally had TREE_SIDE_EFFECTS
1610 set which would have caused all the outer expressions in EXPR_P
1611 leading to P to also have had TREE_SIDE_EFFECTS set. */
1612 recalculate_side_effects (t);
1616 tret = gimplify_expr (p, pre_p, post_p, is_gimple_min_lval, fallback);
1617 ret = MIN (ret, tret);
1619 /* If the outermost expression is a COMPONENT_REF, canonicalize its type. */
1620 if ((fallback & fb_rvalue) && TREE_CODE (*expr_p) == COMPONENT_REF)
1622 canonicalize_component_ref (expr_p);
1623 ret = MIN (ret, GS_OK);
1626 VARRAY_FREE (stack);
1631 /* Gimplify the self modifying expression pointed by EXPR_P (++, --, +=, -=).
1633 PRE_P points to the list where side effects that must happen before
1634 *EXPR_P should be stored.
1636 POST_P points to the list where side effects that must happen after
1637 *EXPR_P should be stored.
1639 WANT_VALUE is nonzero iff we want to use the value of this expression
1640 in another expression. */
1642 static enum gimplify_status
1643 gimplify_self_mod_expr (tree *expr_p, tree *pre_p, tree *post_p,
1646 enum tree_code code;
1647 tree lhs, lvalue, rhs, t1;
1649 enum tree_code arith_code;
1650 enum gimplify_status ret;
1652 code = TREE_CODE (*expr_p);
1654 #if defined ENABLE_CHECKING
1655 if (code != POSTINCREMENT_EXPR
1656 && code != POSTDECREMENT_EXPR
1657 && code != PREINCREMENT_EXPR
1658 && code != PREDECREMENT_EXPR)
1662 /* Prefix or postfix? */
1663 if (code == POSTINCREMENT_EXPR || code == POSTDECREMENT_EXPR)
1664 /* Faster to treat as prefix if result is not used. */
1665 postfix = want_value;
1669 /* Add or subtract? */
1670 if (code == PREINCREMENT_EXPR || code == POSTINCREMENT_EXPR)
1671 arith_code = PLUS_EXPR;
1673 arith_code = MINUS_EXPR;
1675 /* Gimplify the LHS into a GIMPLE lvalue. */
1676 lvalue = TREE_OPERAND (*expr_p, 0);
1677 ret = gimplify_expr (&lvalue, pre_p, post_p, is_gimple_lvalue, fb_lvalue);
1678 if (ret == GS_ERROR)
1681 /* Extract the operands to the arithmetic operation. */
1683 rhs = TREE_OPERAND (*expr_p, 1);
1685 /* For postfix operator, we evaluate the LHS to an rvalue and then use
1686 that as the result value and in the postqueue operation. */
1689 ret = gimplify_expr (&lhs, pre_p, post_p, is_gimple_val, fb_rvalue);
1690 if (ret == GS_ERROR)
1694 t1 = build (arith_code, TREE_TYPE (*expr_p), lhs, rhs);
1695 t1 = build (MODIFY_EXPR, TREE_TYPE (lvalue), lvalue, t1);
1699 gimplify_and_add (t1, post_p);
1710 /* If *EXPR_P has a variable sized type, wrap it in a WITH_SIZE_EXPR. */
1713 maybe_with_size_expr (tree *expr_p)
1715 tree expr = *expr_p;
1716 tree type = TREE_TYPE (expr);
1719 /* If we've already wrapped this or the type is error_mark_node, we can't do
1721 if (TREE_CODE (expr) == WITH_SIZE_EXPR
1722 || type == error_mark_node)
1725 /* If the size isn't known or is a constant, we have nothing to do. */
1726 size = TYPE_SIZE_UNIT (type);
1727 if (!size || TREE_CODE (size) == INTEGER_CST)
1730 /* Otherwise, make a WITH_SIZE_EXPR. */
1731 size = unshare_expr (size);
1732 size = SUBSTITUTE_PLACEHOLDER_IN_EXPR (size, expr);
1733 *expr_p = build2 (WITH_SIZE_EXPR, type, expr, size);
1736 /* Subroutine of gimplify_call_expr: Gimplify a single argument. */
1738 static enum gimplify_status
1739 gimplify_arg (tree *expr_p, tree *pre_p)
1741 bool (*test) (tree);
1744 /* In general, we allow lvalues for function arguments to avoid
1745 extra overhead of copying large aggregates out of even larger
1746 aggregates into temporaries only to copy the temporaries to
1747 the argument list. Make optimizers happy by pulling out to
1748 temporaries those types that fit in registers. */
1749 if (is_gimple_reg_type (TREE_TYPE (*expr_p)))
1750 test = is_gimple_val, fb = fb_rvalue;
1752 test = is_gimple_lvalue, fb = fb_either;
1754 /* If this is a variable sized type, we must remember the size. */
1755 maybe_with_size_expr (expr_p);
1757 /* There is a sequence point before a function call. Side effects in
1758 the argument list must occur before the actual call. So, when
1759 gimplifying arguments, force gimplify_expr to use an internal
1760 post queue which is then appended to the end of PRE_P. */
1761 return gimplify_expr (expr_p, pre_p, NULL, test, fb);
1764 /* Gimplify the CALL_EXPR node pointed by EXPR_P. PRE_P points to the
1765 list where side effects that must happen before *EXPR_P should be stored.
1766 WANT_VALUE is true if the result of the call is desired. */
1768 static enum gimplify_status
1769 gimplify_call_expr (tree *expr_p, tree *pre_p, bool want_value)
1773 enum gimplify_status ret;
1775 #if defined ENABLE_CHECKING
1776 if (TREE_CODE (*expr_p) != CALL_EXPR)
1780 /* For reliable diagnostics during inlining, it is necessary that
1781 every call_expr be annotated with file and line. */
1782 if (! EXPR_HAS_LOCATION (*expr_p))
1783 SET_EXPR_LOCATION (*expr_p, input_location);
1785 /* This may be a call to a builtin function.
1787 Builtin function calls may be transformed into different
1788 (and more efficient) builtin function calls under certain
1789 circumstances. Unfortunately, gimplification can muck things
1790 up enough that the builtin expanders are not aware that certain
1791 transformations are still valid.
1793 So we attempt transformation/gimplification of the call before
1794 we gimplify the CALL_EXPR. At this time we do not manage to
1795 transform all calls in the same manner as the expanders do, but
1796 we do transform most of them. */
1797 decl = get_callee_fndecl (*expr_p);
1798 if (decl && DECL_BUILT_IN (decl))
1800 tree new = simplify_builtin (*expr_p, !want_value);
1802 if (new && new != *expr_p)
1804 /* There was a transformation of this call which computes the
1805 same value, but in a more efficient way. Return and try
1811 if (DECL_FUNCTION_CODE (decl) == BUILT_IN_VA_START)
1812 /* Avoid gimplifying the second argument to va_start, which needs
1813 to be the plain PARM_DECL. */
1814 return gimplify_arg (&TREE_VALUE (TREE_OPERAND (*expr_p, 1)), pre_p);
1817 /* There is a sequence point before the call, so any side effects in
1818 the calling expression must occur before the actual call. Force
1819 gimplify_expr to use an internal post queue. */
1820 ret = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p, NULL,
1821 is_gimple_call_addr, fb_rvalue);
1823 if (PUSH_ARGS_REVERSED)
1824 TREE_OPERAND (*expr_p, 1) = nreverse (TREE_OPERAND (*expr_p, 1));
1825 for (arglist = TREE_OPERAND (*expr_p, 1); arglist;
1826 arglist = TREE_CHAIN (arglist))
1828 enum gimplify_status t;
1830 t = gimplify_arg (&TREE_VALUE (arglist), pre_p);
1835 if (PUSH_ARGS_REVERSED)
1836 TREE_OPERAND (*expr_p, 1) = nreverse (TREE_OPERAND (*expr_p, 1));
1838 /* Try this again in case gimplification exposed something. */
1839 if (ret != GS_ERROR && decl && DECL_BUILT_IN (decl))
1841 tree new = simplify_builtin (*expr_p, !want_value);
1843 if (new && new != *expr_p)
1845 /* There was a transformation of this call which computes the
1846 same value, but in a more efficient way. Return and try
1853 /* If the function is "const" or "pure", then clear TREE_SIDE_EFFECTS on its
1854 decl. This allows us to eliminate redundant or useless
1855 calls to "const" functions. */
1856 if (TREE_CODE (*expr_p) == CALL_EXPR
1857 && (call_expr_flags (*expr_p) & (ECF_CONST | ECF_PURE)))
1858 TREE_SIDE_EFFECTS (*expr_p) = 0;
1863 /* Handle shortcut semantics in the predicate operand of a COND_EXPR by
1864 rewriting it into multiple COND_EXPRs, and possibly GOTO_EXPRs.
1866 TRUE_LABEL_P and FALSE_LABEL_P point to the labels to jump to if the
1867 condition is true or false, respectively. If null, we should generate
1868 our own to skip over the evaluation of this specific expression.
1870 This function is the tree equivalent of do_jump.
1872 shortcut_cond_r should only be called by shortcut_cond_expr. */
1875 shortcut_cond_r (tree pred, tree *true_label_p, tree *false_label_p)
1877 tree local_label = NULL_TREE;
1878 tree t, expr = NULL;
1880 /* OK, it's not a simple case; we need to pull apart the COND_EXPR to
1881 retain the shortcut semantics. Just insert the gotos here;
1882 shortcut_cond_expr will append the real blocks later. */
1883 if (TREE_CODE (pred) == TRUTH_ANDIF_EXPR)
1885 /* Turn if (a && b) into
1887 if (a); else goto no;
1888 if (b) goto yes; else goto no;
1891 if (false_label_p == NULL)
1892 false_label_p = &local_label;
1894 t = shortcut_cond_r (TREE_OPERAND (pred, 0), NULL, false_label_p);
1895 append_to_statement_list (t, &expr);
1897 t = shortcut_cond_r (TREE_OPERAND (pred, 1), true_label_p,
1899 append_to_statement_list (t, &expr);
1901 else if (TREE_CODE (pred) == TRUTH_ORIF_EXPR)
1903 /* Turn if (a || b) into
1906 if (b) goto yes; else goto no;
1909 if (true_label_p == NULL)
1910 true_label_p = &local_label;
1912 t = shortcut_cond_r (TREE_OPERAND (pred, 0), true_label_p, NULL);
1913 append_to_statement_list (t, &expr);
1915 t = shortcut_cond_r (TREE_OPERAND (pred, 1), true_label_p,
1917 append_to_statement_list (t, &expr);
1919 else if (TREE_CODE (pred) == COND_EXPR)
1921 /* As long as we're messing with gotos, turn if (a ? b : c) into
1923 if (b) goto yes; else goto no;
1925 if (c) goto yes; else goto no; */
1926 expr = build (COND_EXPR, void_type_node, TREE_OPERAND (pred, 0),
1927 shortcut_cond_r (TREE_OPERAND (pred, 1), true_label_p,
1929 shortcut_cond_r (TREE_OPERAND (pred, 2), true_label_p,
1934 expr = build (COND_EXPR, void_type_node, pred,
1935 build_and_jump (true_label_p),
1936 build_and_jump (false_label_p));
1941 t = build1 (LABEL_EXPR, void_type_node, local_label);
1942 append_to_statement_list (t, &expr);
1949 shortcut_cond_expr (tree expr)
1951 tree pred = TREE_OPERAND (expr, 0);
1952 tree then_ = TREE_OPERAND (expr, 1);
1953 tree else_ = TREE_OPERAND (expr, 2);
1954 tree true_label, false_label, end_label, t;
1956 tree *false_label_p;
1957 bool emit_end, emit_false;
1958 bool then_se = then_ && TREE_SIDE_EFFECTS (then_);
1959 bool else_se = else_ && TREE_SIDE_EFFECTS (else_);
1961 /* First do simple transformations. */
1964 /* If there is no 'else', turn (a && b) into if (a) if (b). */
1965 while (TREE_CODE (pred) == TRUTH_ANDIF_EXPR)
1967 TREE_OPERAND (expr, 0) = TREE_OPERAND (pred, 1);
1968 then_ = shortcut_cond_expr (expr);
1969 pred = TREE_OPERAND (pred, 0);
1970 expr = build (COND_EXPR, void_type_node, pred, then_, NULL_TREE);
1975 /* If there is no 'then', turn
1978 if (a); else if (b); else d. */
1979 while (TREE_CODE (pred) == TRUTH_ORIF_EXPR)
1981 TREE_OPERAND (expr, 0) = TREE_OPERAND (pred, 1);
1982 else_ = shortcut_cond_expr (expr);
1983 pred = TREE_OPERAND (pred, 0);
1984 expr = build (COND_EXPR, void_type_node, pred, NULL_TREE, else_);
1988 /* If we're done, great. */
1989 if (TREE_CODE (pred) != TRUTH_ANDIF_EXPR
1990 && TREE_CODE (pred) != TRUTH_ORIF_EXPR)
1993 /* Otherwise we need to mess with gotos. Change
1996 if (a); else goto no;
1999 and recursively gimplify the condition. */
2001 true_label = false_label = end_label = NULL_TREE;
2003 /* If our arms just jump somewhere, hijack those labels so we don't
2004 generate jumps to jumps. */
2007 && TREE_CODE (then_) == GOTO_EXPR
2008 && TREE_CODE (GOTO_DESTINATION (then_)) == LABEL_DECL)
2010 true_label = GOTO_DESTINATION (then_);
2016 && TREE_CODE (else_) == GOTO_EXPR
2017 && TREE_CODE (GOTO_DESTINATION (else_)) == LABEL_DECL)
2019 false_label = GOTO_DESTINATION (else_);
2024 /* If we aren't hijacking a label for the 'then' branch, it falls through. */
2026 true_label_p = &true_label;
2028 true_label_p = NULL;
2030 /* The 'else' branch also needs a label if it contains interesting code. */
2031 if (false_label || else_se)
2032 false_label_p = &false_label;
2034 false_label_p = NULL;
2036 /* If there was nothing else in our arms, just forward the label(s). */
2037 if (!then_se && !else_se)
2038 return shortcut_cond_r (pred, true_label_p, false_label_p);
2040 /* If our last subexpression already has a terminal label, reuse it. */
2042 expr = expr_last (else_);
2044 expr = expr_last (then_);
2047 if (expr && TREE_CODE (expr) == LABEL_EXPR)
2048 end_label = LABEL_EXPR_LABEL (expr);
2050 /* If we don't care about jumping to the 'else' branch, jump to the end
2051 if the condition is false. */
2053 false_label_p = &end_label;
2055 /* We only want to emit these labels if we aren't hijacking them. */
2056 emit_end = (end_label == NULL_TREE);
2057 emit_false = (false_label == NULL_TREE);
2059 pred = shortcut_cond_r (pred, true_label_p, false_label_p);
2062 append_to_statement_list (pred, &expr);
2064 append_to_statement_list (then_, &expr);
2067 t = build_and_jump (&end_label);
2068 append_to_statement_list (t, &expr);
2071 t = build1 (LABEL_EXPR, void_type_node, false_label);
2072 append_to_statement_list (t, &expr);
2074 append_to_statement_list (else_, &expr);
2076 if (emit_end && end_label)
2078 t = build1 (LABEL_EXPR, void_type_node, end_label);
2079 append_to_statement_list (t, &expr);
2085 /* EXPR is used in a boolean context; make sure it has BOOLEAN_TYPE. */
2088 gimple_boolify (tree expr)
2090 tree type = TREE_TYPE (expr);
2092 if (TREE_CODE (type) == BOOLEAN_TYPE)
2095 /* If this is the predicate of a COND_EXPR, it might not even be a
2097 expr = lang_hooks.truthvalue_conversion (expr);
2099 switch (TREE_CODE (expr))
2101 case TRUTH_AND_EXPR:
2103 case TRUTH_XOR_EXPR:
2104 case TRUTH_ANDIF_EXPR:
2105 case TRUTH_ORIF_EXPR:
2106 /* Also boolify the arguments of truth exprs. */
2107 TREE_OPERAND (expr, 1) = gimple_boolify (TREE_OPERAND (expr, 1));
2110 case TRUTH_NOT_EXPR:
2111 TREE_OPERAND (expr, 0) = gimple_boolify (TREE_OPERAND (expr, 0));
2114 case EQ_EXPR: case NE_EXPR:
2115 case LE_EXPR: case GE_EXPR: case LT_EXPR: case GT_EXPR:
2116 /* These expressions always produce boolean results. */
2117 TREE_TYPE (expr) = boolean_type_node;
2121 /* Other expressions that get here must have boolean values, but
2122 might need to be converted to the appropriate mode. */
2123 return convert (boolean_type_node, expr);
2127 /* Convert the conditional expression pointed by EXPR_P '(p) ? a : b;'
2136 The second form is used when *EXPR_P is of type void.
2138 TARGET is the tree for T1 above.
2140 PRE_P points to the list where side effects that must happen before
2141 *EXPR_P should be stored. */
2143 static enum gimplify_status
2144 gimplify_cond_expr (tree *expr_p, tree *pre_p, tree target)
2146 tree expr = *expr_p;
2147 tree tmp, tmp2, type;
2148 enum gimplify_status ret;
2150 type = TREE_TYPE (expr);
2152 TREE_TYPE (expr) = void_type_node;
2154 /* If this COND_EXPR has a value, copy the values into a temporary within
2156 else if (! VOID_TYPE_P (type))
2160 ret = gimplify_expr (&target, pre_p, NULL,
2161 is_gimple_min_lval, fb_lvalue);
2162 if (ret != GS_ERROR)
2165 tmp2 = unshare_expr (target);
2169 tmp2 = tmp = create_tmp_var (TREE_TYPE (expr), "iftmp");
2173 /* Build the then clause, 't1 = a;'. But don't build an assignment
2174 if this branch is void; in C++ it can be, if it's a throw. */
2175 if (TREE_TYPE (TREE_OPERAND (expr, 1)) != void_type_node)
2176 TREE_OPERAND (expr, 1)
2177 = build (MODIFY_EXPR, void_type_node, tmp, TREE_OPERAND (expr, 1));
2179 /* Build the else clause, 't1 = b;'. */
2180 if (TREE_TYPE (TREE_OPERAND (expr, 2)) != void_type_node)
2181 TREE_OPERAND (expr, 2)
2182 = build (MODIFY_EXPR, void_type_node, tmp2, TREE_OPERAND (expr, 2));
2184 TREE_TYPE (expr) = void_type_node;
2185 recalculate_side_effects (expr);
2187 /* Move the COND_EXPR to the prequeue. */
2188 gimplify_and_add (expr, pre_p);
2194 /* Make sure the condition has BOOLEAN_TYPE. */
2195 TREE_OPERAND (expr, 0) = gimple_boolify (TREE_OPERAND (expr, 0));
2197 /* Break apart && and || conditions. */
2198 if (TREE_CODE (TREE_OPERAND (expr, 0)) == TRUTH_ANDIF_EXPR
2199 || TREE_CODE (TREE_OPERAND (expr, 0)) == TRUTH_ORIF_EXPR)
2201 expr = shortcut_cond_expr (expr);
2203 if (expr != *expr_p)
2207 /* We can't rely on gimplify_expr to re-gimplify the expanded
2208 form properly, as cleanups might cause the target labels to be
2209 wrapped in a TRY_FINALLY_EXPR. To prevent that, we need to
2210 set up a conditional context. */
2211 gimple_push_condition ();
2212 gimplify_stmt (expr_p);
2213 gimple_pop_condition (pre_p);
2219 /* Now do the normal gimplification. */
2220 ret = gimplify_expr (&TREE_OPERAND (expr, 0), pre_p, NULL,
2221 is_gimple_condexpr, fb_rvalue);
2223 gimple_push_condition ();
2225 gimplify_to_stmt_list (&TREE_OPERAND (expr, 1));
2226 gimplify_to_stmt_list (&TREE_OPERAND (expr, 2));
2227 recalculate_side_effects (expr);
2229 gimple_pop_condition (pre_p);
2231 if (ret == GS_ERROR)
2233 else if (TREE_SIDE_EFFECTS (TREE_OPERAND (expr, 1)))
2235 else if (TREE_SIDE_EFFECTS (TREE_OPERAND (expr, 2)))
2236 /* Rewrite "if (a); else b" to "if (!a) b" */
2238 TREE_OPERAND (expr, 0) = invert_truthvalue (TREE_OPERAND (expr, 0));
2239 ret = gimplify_expr (&TREE_OPERAND (expr, 0), pre_p, NULL,
2240 is_gimple_condexpr, fb_rvalue);
2242 tmp = TREE_OPERAND (expr, 1);
2243 TREE_OPERAND (expr, 1) = TREE_OPERAND (expr, 2);
2244 TREE_OPERAND (expr, 2) = tmp;
2247 /* Both arms are empty; replace the COND_EXPR with its predicate. */
2248 expr = TREE_OPERAND (expr, 0);
2254 /* A subroutine of gimplify_modify_expr. Replace a MODIFY_EXPR with
2255 a call to __builtin_memcpy. */
2257 static enum gimplify_status
2258 gimplify_modify_expr_to_memcpy (tree *expr_p, tree size, bool want_value)
2260 tree args, t, to, to_ptr, from;
2262 to = TREE_OPERAND (*expr_p, 0);
2263 from = TREE_OPERAND (*expr_p, 1);
2265 args = tree_cons (NULL, size, NULL);
2267 t = build_fold_addr_expr (from);
2268 args = tree_cons (NULL, t, args);
2270 to_ptr = build_fold_addr_expr (to);
2271 args = tree_cons (NULL, to_ptr, args);
2272 t = implicit_built_in_decls[BUILT_IN_MEMCPY];
2273 t = build_function_call_expr (t, args);
2277 t = build1 (NOP_EXPR, TREE_TYPE (to_ptr), t);
2278 t = build1 (INDIRECT_REF, TREE_TYPE (to), t);
2285 /* A subroutine of gimplify_modify_expr. Replace a MODIFY_EXPR with
2286 a call to __builtin_memset. In this case we know that the RHS is
2287 a CONSTRUCTOR with an empty element list. */
2289 static enum gimplify_status
2290 gimplify_modify_expr_to_memset (tree *expr_p, tree size, bool want_value)
2292 tree args, t, to, to_ptr;
2294 to = TREE_OPERAND (*expr_p, 0);
2296 args = tree_cons (NULL, size, NULL);
2298 args = tree_cons (NULL, integer_zero_node, args);
2300 to_ptr = build_fold_addr_expr (to);
2301 args = tree_cons (NULL, to_ptr, args);
2302 t = implicit_built_in_decls[BUILT_IN_MEMSET];
2303 t = build_function_call_expr (t, args);
2307 t = build1 (NOP_EXPR, TREE_TYPE (to_ptr), t);
2308 t = build1 (INDIRECT_REF, TREE_TYPE (to), t);
2315 /* A subroutine of gimplify_init_ctor_preeval. Called via walk_tree,
2316 determine, cautiously, if a CONSTRUCTOR overlaps the lhs of an
2317 assignment. Returns non-null if we detect a potential overlap. */
2319 struct gimplify_init_ctor_preeval_data
2321 /* The base decl of the lhs object. May be NULL, in which case we
2322 have to assume the lhs is indirect. */
2325 /* The alias set of the lhs object. */
2330 gimplify_init_ctor_preeval_1 (tree *tp, int *walk_subtrees, void *xdata)
2332 struct gimplify_init_ctor_preeval_data *data
2333 = (struct gimplify_init_ctor_preeval_data *) xdata;
2336 /* If we find the base object, obviously we have overlap. */
2337 if (data->lhs_base_decl == t)
2340 /* If the constructor component is indirect, determine if we have a
2341 potential overlap with the lhs. The only bits of information we
2342 have to go on at this point are addressability and alias sets. */
2343 if (TREE_CODE (t) == INDIRECT_REF
2344 && (!data->lhs_base_decl || TREE_ADDRESSABLE (data->lhs_base_decl))
2345 && alias_sets_conflict_p (data->lhs_alias_set, get_alias_set (t)))
2348 if (DECL_P (t) || TYPE_P (t))
2353 /* A subroutine of gimplify_init_constructor. Pre-evaluate *EXPR_P,
2354 force values that overlap with the lhs (as described by *DATA)
2355 into temporaries. */
2358 gimplify_init_ctor_preeval (tree *expr_p, tree *pre_p, tree *post_p,
2359 struct gimplify_init_ctor_preeval_data *data)
2361 enum gimplify_status one;
2363 /* If the value is invariant, then there's nothing to pre-evaluate.
2364 But ensure it doesn't have any side-effects since a SAVE_EXPR is
2365 invariant but has side effects and might contain a reference to
2366 the object we're initializing. */
2367 if (TREE_INVARIANT (*expr_p) && !TREE_SIDE_EFFECTS (*expr_p))
2370 /* If the type has non-trivial constructors, we can't pre-evaluate. */
2371 if (TREE_ADDRESSABLE (TREE_TYPE (*expr_p)))
2374 /* Recurse for nested constructors. */
2375 if (TREE_CODE (*expr_p) == CONSTRUCTOR)
2378 for (list = CONSTRUCTOR_ELTS (*expr_p); list ; list = TREE_CHAIN (list))
2379 gimplify_init_ctor_preeval (&TREE_VALUE (list), pre_p, post_p, data);
2383 /* We can't preevaluate if the type contains a placeholder. */
2384 if (type_contains_placeholder_p (TREE_TYPE (*expr_p)))
2387 /* Gimplify the constructor element to something appropriate for the rhs
2388 of a MODIFY_EXPR. Given that we know the lhs is an aggregate, we know
2389 the gimplifier will consider this a store to memory. Doing this
2390 gimplification now means that we won't have to deal with complicated
2391 language-specific trees, nor trees like SAVE_EXPR that can induce
2392 exponential search behaviour. */
2393 one = gimplify_expr (expr_p, pre_p, post_p, is_gimple_mem_rhs, fb_rvalue);
2394 if (one == GS_ERROR)
2400 /* If we gimplified to a bare decl, we can be sure that it doesn't overlap
2401 with the lhs, since "a = { .x=a }" doesn't make sense. This will
2402 always be true for all scalars, since is_gimple_mem_rhs insists on a
2403 temporary variable for them. */
2404 if (DECL_P (*expr_p))
2407 /* If this is of variable size, we have no choice but to assume it doesn't
2408 overlap since we can't make a temporary for it. */
2409 if (!TREE_CONSTANT (TYPE_SIZE (TREE_TYPE (*expr_p))))
2412 /* Otherwise, we must search for overlap ... */
2413 if (!walk_tree (expr_p, gimplify_init_ctor_preeval_1, data, NULL))
2416 /* ... and if found, force the value into a temporary. */
2417 *expr_p = get_formal_tmp_var (*expr_p, pre_p);
2420 /* A subroutine of gimplify_init_constructor. Generate individual
2421 MODIFY_EXPRs for a CONSTRUCTOR. OBJECT is the LHS against which the
2422 assignments should happen. LIST is the CONSTRUCTOR_ELTS of the
2423 CONSTRUCTOR. CLEARED is true if the entire LHS object has been
2427 gimplify_init_ctor_eval (tree object, tree list, tree *pre_p, bool cleared)
2429 tree array_elt_type = NULL;
2431 if (TREE_CODE (TREE_TYPE (object)) == ARRAY_TYPE)
2432 array_elt_type = TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (object)));
2434 for (; list; list = TREE_CHAIN (list))
2436 tree purpose, value, cref, init;
2438 purpose = TREE_PURPOSE (list);
2439 value = TREE_VALUE (list);
2441 /* NULL values are created above for gimplification errors. */
2445 if (cleared && initializer_zerop (value))
2450 /* ??? Here's to hoping the front end fills in all of the indicies,
2451 so we don't have to figure out what's missing ourselves. */
2454 /* ??? Need to handle this. */
2455 if (TREE_CODE (purpose) == RANGE_EXPR)
2458 cref = build (ARRAY_REF, array_elt_type, unshare_expr (object),
2459 purpose, NULL_TREE, NULL_TREE);
2462 cref = build (COMPONENT_REF, TREE_TYPE (purpose),
2463 unshare_expr (object), purpose, NULL_TREE);
2465 if (TREE_CODE (value) == CONSTRUCTOR)
2466 gimplify_init_ctor_eval (cref, CONSTRUCTOR_ELTS (value),
2470 init = build (MODIFY_EXPR, TREE_TYPE (cref), cref, value);
2471 gimplify_and_add (init, pre_p);
2476 /* A subroutine of gimplify_modify_expr. Break out elements of a
2477 CONSTRUCTOR used as an initializer into separate MODIFY_EXPRs.
2479 Note that we still need to clear any elements that don't have explicit
2480 initializers, so if not all elements are initialized we keep the
2481 original MODIFY_EXPR, we just remove all of the constructor elements. */
2483 static enum gimplify_status
2484 gimplify_init_constructor (tree *expr_p, tree *pre_p,
2485 tree *post_p, bool want_value)
2488 tree ctor = TREE_OPERAND (*expr_p, 1);
2489 tree type = TREE_TYPE (ctor);
2490 enum gimplify_status ret;
2493 if (TREE_CODE (ctor) != CONSTRUCTOR)
2494 return GS_UNHANDLED;
2496 ret = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p, post_p,
2497 is_gimple_lvalue, fb_lvalue);
2498 if (ret == GS_ERROR)
2500 object = TREE_OPERAND (*expr_p, 0);
2502 elt_list = CONSTRUCTOR_ELTS (ctor);
2505 switch (TREE_CODE (type))
2509 case QUAL_UNION_TYPE:
2512 struct gimplify_init_ctor_preeval_data preeval_data;
2513 HOST_WIDE_INT num_elements, num_nonzero_elements;
2514 HOST_WIDE_INT num_nonconstant_elements;
2517 /* Aggregate types must lower constructors to initialization of
2518 individual elements. The exception is that a CONSTRUCTOR node
2519 with no elements indicates zero-initialization of the whole. */
2520 if (elt_list == NULL)
2523 categorize_ctor_elements (ctor, &num_nonzero_elements,
2524 &num_nonconstant_elements);
2526 /* If a const aggregate variable is being initialized, then it
2527 should never be a lose to promote the variable to be static. */
2528 if (num_nonconstant_elements == 0
2529 && TREE_READONLY (object)
2530 && TREE_CODE (object) == VAR_DECL)
2532 DECL_INITIAL (object) = ctor;
2533 TREE_STATIC (object) = 1;
2534 if (!DECL_NAME (object))
2535 DECL_NAME (object) = create_tmp_var_name ("C");
2536 walk_tree (&DECL_INITIAL (object), force_labels_r, NULL, NULL);
2538 /* ??? C++ doesn't automatically append a .<number> to the
2539 assembler name, and even when it does, it looks a FE private
2540 data structures to figure out what that number should be,
2541 which are not set for this variable. I suppose this is
2542 important for local statics for inline functions, which aren't
2543 "local" in the object file sense. So in order to get a unique
2544 TU-local symbol, we must invoke the lhd version now. */
2545 lhd_set_decl_assembler_name (object);
2547 *expr_p = NULL_TREE;
2551 /* If there are "lots" of initialized elements, and all of them
2552 are valid address constants, then the entire initializer can
2553 be dropped to memory, and then memcpy'd out. */
2554 if (num_nonconstant_elements == 0)
2556 HOST_WIDE_INT size = int_size_in_bytes (type);
2559 /* ??? We can still get unbounded array types, at least
2560 from the C++ front end. This seems wrong, but attempt
2561 to work around it for now. */
2564 size = int_size_in_bytes (TREE_TYPE (object));
2566 TREE_TYPE (ctor) = type = TREE_TYPE (object);
2569 /* Find the maximum alignment we can assume for the object. */
2570 /* ??? Make use of DECL_OFFSET_ALIGN. */
2571 if (DECL_P (object))
2572 align = DECL_ALIGN (object);
2574 align = TYPE_ALIGN (type);
2576 if (size > 0 && !can_move_by_pieces (size, align))
2578 tree new = create_tmp_var_raw (type, "C");
2580 gimple_add_tmp_var (new);
2581 TREE_STATIC (new) = 1;
2582 TREE_READONLY (new) = 1;
2583 DECL_INITIAL (new) = ctor;
2584 if (align > DECL_ALIGN (new))
2586 DECL_ALIGN (new) = align;
2587 DECL_USER_ALIGN (new) = 1;
2589 walk_tree (&DECL_INITIAL (new), force_labels_r, NULL, NULL);
2591 TREE_OPERAND (*expr_p, 1) = new;
2593 /* This is no longer an assignment of a CONSTRUCTOR, but
2594 we still may have processing to do on the LHS. So
2595 pretend we didn't do anything here to let that happen. */
2596 return GS_UNHANDLED;
2600 /* If there are "lots" of initialized elements, even discounting
2601 those that are not address constants (and thus *must* be
2602 computed at runtime), then partition the constructor into
2603 constant and non-constant parts. Block copy the constant
2604 parts in, then generate code for the non-constant parts. */
2605 /* TODO. There's code in cp/typeck.c to do this. */
2607 num_elements = count_type_elements (TREE_TYPE (ctor));
2609 /* If there are "lots" of zeros, then block clear the object first. */
2611 if (num_elements - num_nonzero_elements > CLEAR_RATIO
2612 && num_nonzero_elements < num_elements/4)
2615 /* ??? This bit ought not be needed. For any element not present
2616 in the initializer, we should simply set them to zero. Except
2617 we'd need to *find* the elements that are not present, and that
2618 requires trickery to avoid quadratic compile-time behavior in
2619 large cases or excessive memory use in small cases. */
2622 HOST_WIDE_INT len = list_length (elt_list);
2623 if (TREE_CODE (type) == ARRAY_TYPE)
2625 tree nelts = array_type_nelts (type);
2626 if (!host_integerp (nelts, 1)
2627 || tree_low_cst (nelts, 1) + 1 != len)
2630 else if (len != fields_length (type))
2636 /* Zap the CONSTRUCTOR element list, which simplifies this case.
2637 Note that we still have to gimplify, in order to handle the
2638 case of variable sized types. Avoid shared tree structures. */
2639 CONSTRUCTOR_ELTS (ctor) = NULL_TREE;
2640 object = unshare_expr (object);
2641 gimplify_stmt (expr_p);
2642 append_to_statement_list (*expr_p, pre_p);
2645 preeval_data.lhs_base_decl = get_base_address (object);
2646 if (!DECL_P (preeval_data.lhs_base_decl))
2647 preeval_data.lhs_base_decl = NULL;
2648 preeval_data.lhs_alias_set = get_alias_set (object);
2650 gimplify_init_ctor_preeval (&TREE_OPERAND (*expr_p, 1),
2651 pre_p, post_p, &preeval_data);
2652 gimplify_init_ctor_eval (object, elt_list, pre_p, cleared);
2654 *expr_p = NULL_TREE;
2662 /* Extract the real and imaginary parts out of the ctor. */
2666 r = TREE_VALUE (elt_list);
2667 elt_list = TREE_CHAIN (elt_list);
2670 i = TREE_VALUE (elt_list);
2671 if (TREE_CHAIN (elt_list))
2675 if (r == NULL || i == NULL)
2677 tree zero = convert (TREE_TYPE (type), integer_zero_node);
2684 /* Complex types have either COMPLEX_CST or COMPLEX_EXPR to
2685 represent creation of a complex value. */
2686 if (TREE_CONSTANT (r) && TREE_CONSTANT (i))
2688 ctor = build_complex (type, r, i);
2689 TREE_OPERAND (*expr_p, 1) = ctor;
2693 ctor = build (COMPLEX_EXPR, type, r, i);
2694 TREE_OPERAND (*expr_p, 1) = ctor;
2695 ret = gimplify_expr (&TREE_OPERAND (*expr_p, 1), pre_p, post_p,
2696 rhs_predicate_for (TREE_OPERAND (*expr_p, 0)),
2703 /* Go ahead and simplify constant constructors to VECTOR_CST. */
2704 if (TREE_CONSTANT (ctor))
2705 TREE_OPERAND (*expr_p, 1) = build_vector (type, elt_list);
2708 /* Vector types use CONSTRUCTOR all the way through gimple
2709 compilation as a general initializer. */
2710 for (; elt_list; elt_list = TREE_CHAIN (elt_list))
2712 enum gimplify_status tret;
2713 tret = gimplify_expr (&TREE_VALUE (elt_list), pre_p, post_p,
2714 is_gimple_val, fb_rvalue);
2715 if (tret == GS_ERROR)
2722 /* So how did we get a CONSTRUCTOR for a scalar type? */
2726 if (ret == GS_ERROR)
2728 else if (want_value)
2730 append_to_statement_list (*expr_p, pre_p);
2738 /* Subroutine of gimplify_modify_expr to do simplifications of MODIFY_EXPRs
2739 based on the code of the RHS. We loop for as long as something changes. */
2741 static enum gimplify_status
2742 gimplify_modify_expr_rhs (tree *expr_p, tree *from_p, tree *to_p, tree *pre_p,
2743 tree *post_p, bool want_value)
2745 enum gimplify_status ret = GS_OK;
2747 while (ret != GS_UNHANDLED)
2748 switch (TREE_CODE (*from_p))
2752 /* If we are initializing something from a TARGET_EXPR, strip the
2753 TARGET_EXPR and initialize it directly, if possible. This can't
2754 be done if the initializer is void, since that implies that the
2755 temporary is set in some non-trivial way.
2757 ??? What about code that pulls out the temp and uses it
2758 elsewhere? I think that such code never uses the TARGET_EXPR as
2759 an initializer. If I'm wrong, we'll abort because the temp won't
2760 have any RTL. In that case, I guess we'll need to replace
2761 references somehow. */
2762 tree init = TARGET_EXPR_INITIAL (*from_p);
2764 if (!VOID_TYPE_P (TREE_TYPE (init)))
2775 /* Remove any COMPOUND_EXPR in the RHS so the following cases will be
2777 gimplify_compound_expr (from_p, pre_p, true);
2782 /* If we're initializing from a CONSTRUCTOR, break this into
2783 individual MODIFY_EXPRs. */
2784 return gimplify_init_constructor (expr_p, pre_p, post_p, want_value);
2787 /* If we're assigning to a non-register type, push the assignment
2788 down into the branches. This is mandatory for ADDRESSABLE types,
2789 since we cannot generate temporaries for such, but it saves a
2790 copy in other cases as well. */
2791 if (!is_gimple_reg_type (TREE_TYPE (*from_p)))
2794 return gimplify_cond_expr (expr_p, pre_p, *to_p);
2808 /* Gimplify the MODIFY_EXPR node pointed by EXPR_P.
2814 PRE_P points to the list where side effects that must happen before
2815 *EXPR_P should be stored.
2817 POST_P points to the list where side effects that must happen after
2818 *EXPR_P should be stored.
2820 WANT_VALUE is nonzero iff we want to use the value of this expression
2821 in another expression. */
2823 static enum gimplify_status
2824 gimplify_modify_expr (tree *expr_p, tree *pre_p, tree *post_p, bool want_value)
2826 tree *from_p = &TREE_OPERAND (*expr_p, 1);
2827 tree *to_p = &TREE_OPERAND (*expr_p, 0);
2828 enum gimplify_status ret = GS_UNHANDLED;
2830 #if defined ENABLE_CHECKING
2831 if (TREE_CODE (*expr_p) != MODIFY_EXPR && TREE_CODE (*expr_p) != INIT_EXPR)
2835 /* The distinction between MODIFY_EXPR and INIT_EXPR is no longer useful. */
2836 if (TREE_CODE (*expr_p) == INIT_EXPR)
2837 TREE_SET_CODE (*expr_p, MODIFY_EXPR);
2839 /* See if any simplifications can be done based on what the RHS is. */
2840 ret = gimplify_modify_expr_rhs (expr_p, from_p, to_p, pre_p, post_p,
2842 if (ret != GS_UNHANDLED)
2845 /* If the value being copied is of variable width, compute the length
2846 of the copy into a WITH_SIZE_EXPR. Note that we need to do this
2847 before gimplifying any of the operands so that we can resolve any
2848 PLACEHOLDER_EXPRs in the size. Also note that the RTL expander uses
2849 the size of the expression to be copied, not of the destination, so
2850 that is what we must here. */
2851 maybe_with_size_expr (from_p);
2853 ret = gimplify_expr (to_p, pre_p, post_p, is_gimple_lvalue, fb_lvalue);
2854 if (ret == GS_ERROR)
2857 ret = gimplify_expr (from_p, pre_p, post_p,
2858 rhs_predicate_for (*to_p), fb_rvalue);
2859 if (ret == GS_ERROR)
2862 /* Now see if the above changed *from_p to something we handle specially. */
2863 ret = gimplify_modify_expr_rhs (expr_p, from_p, to_p, pre_p, post_p,
2865 if (ret != GS_UNHANDLED)
2868 /* If we've got a variable sized assignment between two lvalues (i.e. does
2869 not involve a call), then we can make things a bit more straightforward
2870 by converting the assignment to memcpy or memset. */
2871 if (TREE_CODE (*from_p) == WITH_SIZE_EXPR)
2873 tree from = TREE_OPERAND (*from_p, 0);
2874 tree size = TREE_OPERAND (*from_p, 1);
2876 if (TREE_CODE (from) == CONSTRUCTOR)
2877 return gimplify_modify_expr_to_memset (expr_p, size, want_value);
2878 if (is_gimple_addressable (from))
2881 return gimplify_modify_expr_to_memcpy (expr_p, size, want_value);
2885 if (gimplify_ctxp->into_ssa && is_gimple_reg (*to_p))
2887 /* If we've somehow already got an SSA_NAME on the LHS, then
2888 we're probably modifying it twice. Not good. */
2889 if (TREE_CODE (*to_p) == SSA_NAME)
2891 *to_p = make_ssa_name (*to_p, *expr_p);
2896 append_to_statement_list (*expr_p, pre_p);
2904 /* Gimplify a comparison between two variable-sized objects. Do this
2905 with a call to BUILT_IN_MEMCMP. */
2907 static enum gimplify_status
2908 gimplify_variable_sized_compare (tree *expr_p)
2910 tree op0 = TREE_OPERAND (*expr_p, 0);
2911 tree op1 = TREE_OPERAND (*expr_p, 1);
2914 t = TYPE_SIZE_UNIT (TREE_TYPE (op0));
2915 t = unshare_expr (t);
2916 t = SUBSTITUTE_PLACEHOLDER_IN_EXPR (t, op0);
2917 args = tree_cons (NULL, t, NULL);
2918 t = build_fold_addr_expr (op1);
2919 args = tree_cons (NULL, t, args);
2920 dest = build_fold_addr_expr (op0);
2921 args = tree_cons (NULL, dest, args);
2922 t = implicit_built_in_decls[BUILT_IN_MEMCMP];
2923 t = build_function_call_expr (t, args);
2925 = build (TREE_CODE (*expr_p), TREE_TYPE (*expr_p), t, integer_zero_node);
2930 /* Gimplify TRUTH_ANDIF_EXPR and TRUTH_ORIF_EXPR expressions. EXPR_P
2931 points to the expression to gimplify.
2933 Expressions of the form 'a && b' are gimplified to:
2935 a && b ? true : false
2937 gimplify_cond_expr will do the rest.
2939 PRE_P points to the list where side effects that must happen before
2940 *EXPR_P should be stored. */
2942 static enum gimplify_status
2943 gimplify_boolean_expr (tree *expr_p)
2945 /* Preserve the original type of the expression. */
2946 tree type = TREE_TYPE (*expr_p);
2948 *expr_p = build (COND_EXPR, type, *expr_p,
2949 convert (type, boolean_true_node),
2950 convert (type, boolean_false_node));
2955 /* Gimplifies an expression sequence. This function gimplifies each
2956 expression and re-writes the original expression with the last
2957 expression of the sequence in GIMPLE form.
2959 PRE_P points to the list where the side effects for all the
2960 expressions in the sequence will be emitted.
2962 WANT_VALUE is true when the result of the last COMPOUND_EXPR is used. */
2963 /* ??? Should rearrange to share the pre-queue with all the indirect
2964 invocations of gimplify_expr. Would probably save on creations
2965 of statement_list nodes. */
2967 static enum gimplify_status
2968 gimplify_compound_expr (tree *expr_p, tree *pre_p, bool want_value)
2974 tree *sub_p = &TREE_OPERAND (t, 0);
2976 if (TREE_CODE (*sub_p) == COMPOUND_EXPR)
2977 gimplify_compound_expr (sub_p, pre_p, false);
2979 gimplify_stmt (sub_p);
2980 append_to_statement_list (*sub_p, pre_p);
2982 t = TREE_OPERAND (t, 1);
2984 while (TREE_CODE (t) == COMPOUND_EXPR);
2991 gimplify_stmt (expr_p);
2996 /* Gimplifies a statement list. These may be created either by an
2997 enlightened front-end, or by shortcut_cond_expr. */
2999 static enum gimplify_status
3000 gimplify_statement_list (tree *expr_p)
3002 tree_stmt_iterator i = tsi_start (*expr_p);
3004 while (!tsi_end_p (i))
3008 gimplify_stmt (tsi_stmt_ptr (i));
3013 else if (TREE_CODE (t) == STATEMENT_LIST)
3015 tsi_link_before (&i, t, TSI_SAME_STMT);
3025 /* Gimplify a SAVE_EXPR node. EXPR_P points to the expression to
3026 gimplify. After gimplification, EXPR_P will point to a new temporary
3027 that holds the original value of the SAVE_EXPR node.
3029 PRE_P points to the list where side effects that must happen before
3030 *EXPR_P should be stored. */
3032 static enum gimplify_status
3033 gimplify_save_expr (tree *expr_p, tree *pre_p, tree *post_p)
3035 enum gimplify_status ret = GS_ALL_DONE;
3038 #if defined ENABLE_CHECKING
3039 if (TREE_CODE (*expr_p) != SAVE_EXPR)
3043 val = TREE_OPERAND (*expr_p, 0);
3045 /* If the SAVE_EXPR has not been resolved, then evaluate it once. */
3046 if (!SAVE_EXPR_RESOLVED_P (*expr_p))
3048 /* The operand may be a void-valued expression such as SAVE_EXPRs
3049 generated by the Java frontend for class initialization. It is
3050 being executed only for its side-effects. */
3051 if (TREE_TYPE (val) == void_type_node)
3053 ret = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p, post_p,
3054 is_gimple_stmt, fb_none);
3055 append_to_statement_list (TREE_OPERAND (*expr_p, 0), pre_p);
3059 val = get_initialized_tmp_var (val, pre_p, post_p);
3061 TREE_OPERAND (*expr_p, 0) = val;
3062 SAVE_EXPR_RESOLVED_P (*expr_p) = 1;
3070 /* Re-write the ADDR_EXPR node pointed by EXPR_P
3077 PRE_P points to the list where side effects that must happen before
3078 *EXPR_P should be stored.
3080 POST_P points to the list where side effects that must happen after
3081 *EXPR_P should be stored. */
3083 static enum gimplify_status
3084 gimplify_addr_expr (tree *expr_p, tree *pre_p, tree *post_p)
3086 tree expr = *expr_p;
3087 tree op0 = TREE_OPERAND (expr, 0);
3088 enum gimplify_status ret;
3090 switch (TREE_CODE (op0))
3093 /* Check if we are dealing with an expression of the form '&*ptr'.
3094 While the front end folds away '&*ptr' into 'ptr', these
3095 expressions may be generated internally by the compiler (e.g.,
3096 builtins like __builtin_va_end). */
3097 *expr_p = TREE_OPERAND (op0, 0);
3101 case VIEW_CONVERT_EXPR:
3102 /* Take the address of our operand and then convert it to the type of
3105 ??? The interactions of VIEW_CONVERT_EXPR and aliasing is not at
3106 all clear. The impact of this transformation is even less clear. */
3107 *expr_p = fold_convert (TREE_TYPE (expr),
3108 build_fold_addr_expr (TREE_OPERAND (op0, 0)));
3113 /* We use fb_either here because the C frontend sometimes takes
3114 the address of a call that returns a struct; see
3115 gcc.dg/c99-array-lval-1.c. The gimplifier will correctly make
3116 the implied temporary explicit. */
3117 ret = gimplify_expr (&TREE_OPERAND (expr, 0), pre_p, post_p,
3118 is_gimple_addressable, fb_either);
3119 if (ret != GS_ERROR)
3121 /* The above may have made an INDIRECT_REF (e.g, Ada's NULL_EXPR),
3122 so check for it here. It's not worth checking for the other
3124 if (TREE_CODE (TREE_OPERAND (expr, 0)) == INDIRECT_REF)
3126 *expr_p = TREE_OPERAND (TREE_OPERAND (expr, 0), 0);
3130 /* Make sure TREE_INVARIANT, TREE_CONSTANT, and TREE_SIDE_EFFECTS
3132 recompute_tree_invarant_for_addr_expr (expr);
3134 /* Mark the RHS addressable. */
3135 lang_hooks.mark_addressable (TREE_OPERAND (expr, 0));
3143 /* Gimplify the operands of an ASM_EXPR. Input operands should be a gimple
3144 value; output operands should be a gimple lvalue. */
3146 static enum gimplify_status
3147 gimplify_asm_expr (tree *expr_p, tree *pre_p, tree *post_p)
3149 tree expr = *expr_p;
3150 int noutputs = list_length (ASM_OUTPUTS (expr));
3151 const char **oconstraints
3152 = (const char **) alloca ((noutputs) * sizeof (const char *));
3155 const char *constraint;
3156 bool allows_mem, allows_reg, is_inout;
3157 enum gimplify_status ret, tret;
3160 = resolve_asm_operand_names (ASM_STRING (expr), ASM_OUTPUTS (expr),
3164 for (i = 0, link = ASM_OUTPUTS (expr); link; ++i, link = TREE_CHAIN (link))
3166 oconstraints[i] = constraint
3167 = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (link)));
3169 parse_output_constraint (&constraint, i, 0, 0,
3170 &allows_mem, &allows_reg, &is_inout);
3172 if (!allows_reg && allows_mem)
3173 lang_hooks.mark_addressable (TREE_VALUE (link));
3175 tret = gimplify_expr (&TREE_VALUE (link), pre_p, post_p,
3176 is_inout ? is_gimple_min_lval : is_gimple_lvalue,
3177 fb_lvalue | fb_mayfail);
3178 if (tret == GS_ERROR)
3180 error ("invalid lvalue in asm output %d", i);
3186 /* An input/output operand. To give the optimizers more
3187 flexibility, split it into separate input and output
3191 size_t constraint_len = strlen (constraint);
3193 /* Turn the in/out constraint into an output constraint. */
3194 char *p = xstrdup (constraint);
3196 TREE_VALUE (TREE_PURPOSE (link)) = build_string (constraint_len, p);
3199 /* And add a matching input constraint. */
3202 sprintf (buf, "%d", i);
3203 input = build_string (strlen (buf), buf);
3206 input = build_string (constraint_len - 1, constraint + 1);
3207 input = build_tree_list (build_tree_list (NULL_TREE, input),
3208 unshare_expr (TREE_VALUE (link)));
3209 ASM_INPUTS (expr) = chainon (ASM_INPUTS (expr), input);
3213 for (link = ASM_INPUTS (expr); link; ++i, link = TREE_CHAIN (link))
3216 = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (link)));
3217 parse_input_constraint (&constraint, 0, 0, noutputs, 0,
3218 oconstraints, &allows_mem, &allows_reg);
3220 /* If the operand is a memory input, it should be an lvalue. */
3221 if (!allows_reg && allows_mem)
3223 lang_hooks.mark_addressable (TREE_VALUE (link));
3224 tret = gimplify_expr (&TREE_VALUE (link), pre_p, post_p,
3225 is_gimple_lvalue, fb_lvalue | fb_mayfail);
3226 if (tret == GS_ERROR)
3228 error ("memory input %d is not directly addressable", i);
3234 tret = gimplify_expr (&TREE_VALUE (link), pre_p, post_p,
3235 is_gimple_val, fb_rvalue);
3236 if (tret == GS_ERROR)
3244 /* Gimplify a CLEANUP_POINT_EXPR. Currently this works by adding
3245 WITH_CLEANUP_EXPRs to the prequeue as we encounter cleanups while
3246 gimplifying the body, and converting them to TRY_FINALLY_EXPRs when we
3247 return to this function.
3249 FIXME should we complexify the prequeue handling instead? Or use flags
3250 for all the cleanups and let the optimizer tighten them up? The current
3251 code seems pretty fragile; it will break on a cleanup within any
3252 non-conditional nesting. But any such nesting would be broken, anyway;
3253 we can't write a TRY_FINALLY_EXPR that starts inside a nesting construct
3254 and continues out of it. We can do that at the RTL level, though, so
3255 having an optimizer to tighten up try/finally regions would be a Good
3258 static enum gimplify_status
3259 gimplify_cleanup_point_expr (tree *expr_p, tree *pre_p)
3261 tree_stmt_iterator iter;
3264 tree temp = voidify_wrapper_expr (*expr_p, NULL);
3266 /* We only care about the number of conditions between the innermost
3267 CLEANUP_POINT_EXPR and the cleanup. So save and reset the count. */
3268 int old_conds = gimplify_ctxp->conditions;
3269 gimplify_ctxp->conditions = 0;
3271 body = TREE_OPERAND (*expr_p, 0);
3272 gimplify_to_stmt_list (&body);
3274 gimplify_ctxp->conditions = old_conds;
3276 for (iter = tsi_start (body); !tsi_end_p (iter); )
3278 tree *wce_p = tsi_stmt_ptr (iter);
3281 if (TREE_CODE (wce) == WITH_CLEANUP_EXPR)
3283 if (tsi_one_before_end_p (iter))
3285 tsi_link_before (&iter, TREE_OPERAND (wce, 0), TSI_SAME_STMT);
3292 enum tree_code code;
3294 if (CLEANUP_EH_ONLY (wce))
3295 code = TRY_CATCH_EXPR;
3297 code = TRY_FINALLY_EXPR;
3299 sl = tsi_split_statement_list_after (&iter);
3300 tfe = build (code, void_type_node, sl, NULL_TREE);
3301 append_to_statement_list (TREE_OPERAND (wce, 0),
3302 &TREE_OPERAND (tfe, 1));
3304 iter = tsi_start (sl);
3314 append_to_statement_list (body, pre_p);
3324 /* Insert a cleanup marker for gimplify_cleanup_point_expr. CLEANUP
3325 is the cleanup action required. */
3328 gimple_push_cleanup (tree var, tree cleanup, bool eh_only, tree *pre_p)
3332 /* Errors can result in improperly nested cleanups. Which results in
3333 confusion when trying to resolve the WITH_CLEANUP_EXPR. */
3334 if (errorcount || sorrycount)
3337 if (gimple_conditional_context ())
3339 /* If we're in a conditional context, this is more complex. We only
3340 want to run the cleanup if we actually ran the initialization that
3341 necessitates it, but we want to run it after the end of the
3342 conditional context. So we wrap the try/finally around the
3343 condition and use a flag to determine whether or not to actually
3344 run the destructor. Thus
3348 becomes (approximately)
3352 if (test) { A::A(temp); flag = 1; val = f(temp); }
3355 if (flag) A::~A(temp);
3360 tree flag = create_tmp_var (boolean_type_node, "cleanup");
3361 tree ffalse = build (MODIFY_EXPR, void_type_node, flag,
3362 boolean_false_node);
3363 tree ftrue = build (MODIFY_EXPR, void_type_node, flag,
3365 cleanup = build (COND_EXPR, void_type_node, flag, cleanup, NULL);
3366 wce = build (WITH_CLEANUP_EXPR, void_type_node, cleanup);
3367 append_to_statement_list (ffalse, &gimplify_ctxp->conditional_cleanups);
3368 append_to_statement_list (wce, &gimplify_ctxp->conditional_cleanups);
3369 append_to_statement_list (ftrue, pre_p);
3371 /* Because of this manipulation, and the EH edges that jump
3372 threading cannot redirect, the temporary (VAR) will appear
3373 to be used uninitialized. Don't warn. */
3374 TREE_NO_WARNING (var) = 1;
3378 wce = build (WITH_CLEANUP_EXPR, void_type_node, cleanup);
3379 CLEANUP_EH_ONLY (wce) = eh_only;
3380 append_to_statement_list (wce, pre_p);
3383 gimplify_stmt (&TREE_OPERAND (wce, 0));
3386 /* Gimplify a TARGET_EXPR which doesn't appear on the rhs of an INIT_EXPR. */
3388 static enum gimplify_status
3389 gimplify_target_expr (tree *expr_p, tree *pre_p, tree *post_p)
3391 tree targ = *expr_p;
3392 tree temp = TARGET_EXPR_SLOT (targ);
3393 tree init = TARGET_EXPR_INITIAL (targ);
3394 enum gimplify_status ret;
3398 /* TARGET_EXPR temps aren't part of the enclosing block, so add it
3399 to the temps list. */
3400 gimple_add_tmp_var (temp);
3402 /* If TARGET_EXPR_INITIAL is void, then the mere evaluation of the
3403 expression is supposed to initialize the slot. */
3404 if (VOID_TYPE_P (TREE_TYPE (init)))
3405 ret = gimplify_expr (&init, pre_p, post_p, is_gimple_stmt, fb_none);
3408 /* Special handling for BIND_EXPR can result in fewer temps. */
3410 if (TREE_CODE (init) == BIND_EXPR)
3411 gimplify_bind_expr (&init, temp, pre_p);
3414 init = build (MODIFY_EXPR, void_type_node, temp, init);
3415 ret = gimplify_expr (&init, pre_p, post_p, is_gimple_stmt,
3419 if (ret == GS_ERROR)
3421 append_to_statement_list (init, pre_p);
3423 /* If needed, push the cleanup for the temp. */
3424 if (TARGET_EXPR_CLEANUP (targ))
3426 gimplify_stmt (&TARGET_EXPR_CLEANUP (targ));
3427 gimple_push_cleanup (temp, TARGET_EXPR_CLEANUP (targ),
3428 CLEANUP_EH_ONLY (targ), pre_p);
3431 /* Only expand this once. */
3432 TREE_OPERAND (targ, 3) = init;
3433 TARGET_EXPR_INITIAL (targ) = NULL_TREE;
3435 else if (!DECL_SEEN_IN_BIND_EXPR_P (temp))
3436 /* We should have expanded this before. */
3443 /* Gimplification of expression trees. */
3445 /* Gimplify an expression which appears at statement context; usually, this
3446 means replacing it with a suitably gimple STATEMENT_LIST. */
3449 gimplify_stmt (tree *stmt_p)
3451 gimplify_expr (stmt_p, NULL, NULL, is_gimple_stmt, fb_none);
3454 /* Similarly, but force the result to be a STATEMENT_LIST. */
3457 gimplify_to_stmt_list (tree *stmt_p)
3459 gimplify_stmt (stmt_p);
3461 *stmt_p = alloc_stmt_list ();
3462 else if (TREE_CODE (*stmt_p) != STATEMENT_LIST)
3465 *stmt_p = alloc_stmt_list ();
3466 append_to_statement_list (t, stmt_p);
3471 /* Gimplifies the expression tree pointed by EXPR_P. Return 0 if
3472 gimplification failed.
3474 PRE_P points to the list where side effects that must happen before
3475 EXPR should be stored.
3477 POST_P points to the list where side effects that must happen after
3478 EXPR should be stored, or NULL if there is no suitable list. In
3479 that case, we copy the result to a temporary, emit the
3480 post-effects, and then return the temporary.
3482 GIMPLE_TEST_F points to a function that takes a tree T and
3483 returns nonzero if T is in the GIMPLE form requested by the
3484 caller. The GIMPLE predicates are in tree-gimple.c.
3486 This test is used twice. Before gimplification, the test is
3487 invoked to determine whether *EXPR_P is already gimple enough. If
3488 that fails, *EXPR_P is gimplified according to its code and
3489 GIMPLE_TEST_F is called again. If the test still fails, then a new
3490 temporary variable is created and assigned the value of the
3491 gimplified expression.
3493 FALLBACK tells the function what sort of a temporary we want. If the 1
3494 bit is set, an rvalue is OK. If the 2 bit is set, an lvalue is OK.
3495 If both are set, either is OK, but an lvalue is preferable.
3497 The return value is either GS_ERROR or GS_ALL_DONE, since this function
3498 iterates until solution. */
3500 enum gimplify_status
3501 gimplify_expr (tree *expr_p, tree *pre_p, tree *post_p,
3502 bool (* gimple_test_f) (tree), fallback_t fallback)
3505 tree internal_pre = NULL_TREE;
3506 tree internal_post = NULL_TREE;
3508 int is_statement = (pre_p == NULL);
3509 location_t saved_location;
3510 enum gimplify_status ret;
3512 save_expr = *expr_p;
3513 if (save_expr == NULL_TREE)
3516 /* We used to check the predicate here and return immediately if it
3517 succeeds. This is wrong; the design is for gimplification to be
3518 idempotent, and for the predicates to only test for valid forms, not
3519 whether they are fully simplified. */
3521 /* Set up our internal queues if needed. */
3523 pre_p = &internal_pre;
3525 post_p = &internal_post;
3527 saved_location = input_location;
3528 if (save_expr != error_mark_node
3529 && EXPR_HAS_LOCATION (*expr_p))
3530 input_location = EXPR_LOCATION (*expr_p);
3532 /* Loop over the specific gimplifiers until the toplevel node
3533 remains the same. */
3536 /* Strip away as many useless type conversions as possible
3538 STRIP_USELESS_TYPE_CONVERSION (*expr_p);
3540 /* Remember the expr. */
3541 save_expr = *expr_p;
3543 /* Die, die, die, my darling. */
3544 if (save_expr == error_mark_node
3545 || (TREE_TYPE (save_expr)
3546 && TREE_TYPE (save_expr) == error_mark_node))
3552 /* Do any language-specific gimplification. */
3553 ret = lang_hooks.gimplify_expr (expr_p, pre_p, post_p);
3556 if (*expr_p == NULL_TREE)
3558 if (*expr_p != save_expr)
3561 else if (ret != GS_UNHANDLED)
3565 switch (TREE_CODE (*expr_p))
3567 /* First deal with the special cases. */
3569 case POSTINCREMENT_EXPR:
3570 case POSTDECREMENT_EXPR:
3571 case PREINCREMENT_EXPR:
3572 case PREDECREMENT_EXPR:
3573 ret = gimplify_self_mod_expr (expr_p, pre_p, post_p,
3574 fallback != fb_none);
3578 case ARRAY_RANGE_REF:
3582 case VIEW_CONVERT_EXPR:
3583 ret = gimplify_compound_lval (expr_p, pre_p, post_p,
3584 fallback ? fallback : fb_rvalue);
3588 ret = gimplify_cond_expr (expr_p, pre_p, NULL_TREE);
3592 ret = gimplify_call_expr (expr_p, pre_p, fallback != fb_none);
3599 ret = gimplify_compound_expr (expr_p, pre_p, fallback != fb_none);
3604 ret = gimplify_modify_expr (expr_p, pre_p, post_p,
3605 fallback != fb_none);
3608 case TRUTH_ANDIF_EXPR:
3609 case TRUTH_ORIF_EXPR:
3610 ret = gimplify_boolean_expr (expr_p);
3613 case TRUTH_NOT_EXPR:
3614 TREE_OPERAND (*expr_p, 0)
3615 = gimple_boolify (TREE_OPERAND (*expr_p, 0));
3616 ret = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p, post_p,
3617 is_gimple_val, fb_rvalue);
3618 recalculate_side_effects (*expr_p);
3622 ret = gimplify_addr_expr (expr_p, pre_p, post_p);
3626 ret = gimplify_va_arg_expr (expr_p, pre_p, post_p);
3631 if (IS_EMPTY_STMT (*expr_p))
3637 if (VOID_TYPE_P (TREE_TYPE (*expr_p))
3638 || fallback == fb_none)
3640 /* Just strip a conversion to void (or in void context) and
3642 *expr_p = TREE_OPERAND (*expr_p, 0);
3646 ret = gimplify_conversion (expr_p);
3647 if (ret == GS_ERROR)
3649 if (*expr_p != save_expr)
3653 case FIX_TRUNC_EXPR:
3655 case FIX_FLOOR_EXPR:
3656 case FIX_ROUND_EXPR:
3657 /* unary_expr: ... | '(' cast ')' val | ... */
3658 ret = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p, post_p,
3659 is_gimple_val, fb_rvalue);
3660 recalculate_side_effects (*expr_p);
3664 ret = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p, post_p,
3665 is_gimple_reg, fb_rvalue);
3666 recalculate_side_effects (*expr_p);
3669 /* Constants need not be gimplified. */
3679 /* If we require an lvalue, such as for ADDR_EXPR, retain the
3680 CONST_DECL node. Otherwise the decl is replaceable by its
3682 /* ??? Should be == fb_lvalue, but ADDR_EXPR passes fb_either. */
3683 if (fallback & fb_lvalue)
3686 *expr_p = DECL_INITIAL (*expr_p);
3690 ret = gimplify_decl_expr (expr_p);
3694 /* FIXME make this a decl. */
3699 ret = gimplify_bind_expr (expr_p, NULL, pre_p);
3703 ret = gimplify_loop_expr (expr_p, pre_p);
3707 ret = gimplify_switch_expr (expr_p, pre_p);
3710 case LABELED_BLOCK_EXPR:
3711 ret = gimplify_labeled_block_expr (expr_p);
3714 case EXIT_BLOCK_EXPR:
3715 ret = gimplify_exit_block_expr (expr_p);
3719 ret = gimplify_exit_expr (expr_p);
3723 /* If the target is not LABEL, then it is a computed jump
3724 and the target needs to be gimplified. */
3725 if (TREE_CODE (GOTO_DESTINATION (*expr_p)) != LABEL_DECL)
3726 ret = gimplify_expr (&GOTO_DESTINATION (*expr_p), pre_p,
3727 NULL, is_gimple_val, fb_rvalue);
3732 #ifdef ENABLE_CHECKING
3733 if (decl_function_context (LABEL_EXPR_LABEL (*expr_p)) != current_function_decl)
3738 case CASE_LABEL_EXPR:
3739 ret = gimplify_case_label_expr (expr_p);
3743 ret = gimplify_return_expr (*expr_p, pre_p);
3747 /* Don't reduce this in place; let gimplify_init_constructor work its
3748 magic. Buf if we're just elaborating this for side effects, just
3749 gimplify any element that has side-effects. */
3750 if (fallback == fb_none)
3752 for (tmp = CONSTRUCTOR_ELTS (*expr_p); tmp;
3753 tmp = TREE_CHAIN (tmp))
3754 if (TREE_SIDE_EFFECTS (TREE_VALUE (tmp)))
3755 gimplify_expr (&TREE_VALUE (tmp), pre_p, post_p,
3756 gimple_test_f, fallback);
3758 *expr_p = NULL_TREE;
3764 /* The following are special cases that are not handled by the
3765 original GIMPLE grammar. */
3767 /* SAVE_EXPR nodes are converted into a GIMPLE identifier and
3770 ret = gimplify_save_expr (expr_p, pre_p, post_p);
3775 enum gimplify_status r0, r1, r2;
3777 r0 = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p, post_p,
3778 is_gimple_lvalue, fb_either);
3779 r1 = gimplify_expr (&TREE_OPERAND (*expr_p, 1), pre_p, post_p,
3780 is_gimple_val, fb_rvalue);
3781 r2 = gimplify_expr (&TREE_OPERAND (*expr_p, 2), pre_p, post_p,
3782 is_gimple_val, fb_rvalue);
3783 recalculate_side_effects (*expr_p);
3785 ret = MIN (r0, MIN (r1, r2));
3789 case NON_LVALUE_EXPR:
3790 /* This should have been stripped above. */
3795 ret = gimplify_asm_expr (expr_p, pre_p, post_p);
3798 case TRY_FINALLY_EXPR:
3799 case TRY_CATCH_EXPR:
3800 gimplify_to_stmt_list (&TREE_OPERAND (*expr_p, 0));
3801 gimplify_to_stmt_list (&TREE_OPERAND (*expr_p, 1));
3805 case CLEANUP_POINT_EXPR:
3806 ret = gimplify_cleanup_point_expr (expr_p, pre_p);
3810 ret = gimplify_target_expr (expr_p, pre_p, post_p);
3814 gimplify_to_stmt_list (&CATCH_BODY (*expr_p));
3818 case EH_FILTER_EXPR:
3819 gimplify_to_stmt_list (&EH_FILTER_FAILURE (*expr_p));
3825 enum gimplify_status r0, r1;
3826 r0 = gimplify_expr (&OBJ_TYPE_REF_OBJECT (*expr_p), pre_p, post_p,
3827 is_gimple_val, fb_rvalue);
3828 r1 = gimplify_expr (&OBJ_TYPE_REF_EXPR (*expr_p), pre_p, post_p,
3829 is_gimple_val, fb_rvalue);
3835 /* We get here when taking the address of a label. We mark
3836 the label as "forced"; meaning it can never be removed and
3837 it is a potential target for any computed goto. */
3838 FORCED_LABEL (*expr_p) = 1;
3842 case STATEMENT_LIST:
3843 ret = gimplify_statement_list (expr_p);
3846 case WITH_SIZE_EXPR:
3848 enum gimplify_status r0, r1;
3849 r0 = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p,
3850 post_p == &internal_post ? NULL : post_p,
3851 gimple_test_f, fallback);
3852 r1 = gimplify_expr (&TREE_OPERAND (*expr_p, 1), pre_p, post_p,
3853 is_gimple_val, fb_rvalue);
3858 /* ??? If this is a local variable, and it has not been seen in any
3859 outer BIND_EXPR, then it's probably the result of a duplicate
3860 declaration, for which we've already issued an error. It would
3861 be really nice if the front end wouldn't leak these at all.
3862 Currently the only known culprit is C++ destructors, as seen
3863 in g++.old-deja/g++.jason/binding.C. */
3865 if (!TREE_STATIC (tmp) && !DECL_EXTERNAL (tmp)
3866 && decl_function_context (tmp) == current_function_decl
3867 && !DECL_SEEN_IN_BIND_EXPR_P (tmp))
3869 #ifdef ENABLE_CHECKING
3870 if (!errorcount && !sorrycount)
3877 /* If this is a local variable sized decl, it must be accessed
3878 indirectly. Perform that substitution. */
3879 if (DECL_VALUE_EXPR (tmp))
3881 *expr_p = unshare_expr (DECL_VALUE_EXPR (tmp));
3890 /* Allow callbacks into the gimplifier during optimization. */
3895 /* If this is a comparison of objects of aggregate type, handle
3896 it specially (by converting to a call to memcmp). It would be
3897 nice to only have to do this for variable-sized objects, but
3898 then we'd have to allow the same nest of reference nodes we
3899 allow for MODIFY_EXPR and that's too complex. */
3900 if (TREE_CODE_CLASS (TREE_CODE (*expr_p)) == '<'
3901 && (AGGREGATE_TYPE_P (TREE_TYPE (TREE_OPERAND (*expr_p, 1)))))
3902 ret = gimplify_variable_sized_compare (expr_p);
3904 /* If *EXPR_P does not need to be special-cased, handle it
3905 according to its class. */
3906 else if (TREE_CODE_CLASS (TREE_CODE (*expr_p)) == '1')
3907 ret = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p,
3908 post_p, is_gimple_val, fb_rvalue);
3909 else if (TREE_CODE_CLASS (TREE_CODE (*expr_p)) == '2'
3910 || TREE_CODE_CLASS (TREE_CODE (*expr_p)) == '<'
3911 || TREE_CODE (*expr_p) == TRUTH_AND_EXPR
3912 || TREE_CODE (*expr_p) == TRUTH_OR_EXPR
3913 || TREE_CODE (*expr_p) == TRUTH_XOR_EXPR)
3915 enum gimplify_status r0, r1;
3917 r0 = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p,
3918 post_p, is_gimple_val, fb_rvalue);
3919 r1 = gimplify_expr (&TREE_OPERAND (*expr_p, 1), pre_p,
3920 post_p, is_gimple_val, fb_rvalue);
3924 else if (TREE_CODE_CLASS (TREE_CODE (*expr_p)) == 'd'
3925 || TREE_CODE_CLASS (TREE_CODE (*expr_p)) == 'c')
3931 /* Fail if we don't know how to handle this tree code. */
3934 recalculate_side_effects (*expr_p);
3938 /* If we replaced *expr_p, gimplify again. */
3939 if (ret == GS_OK && (*expr_p == NULL || *expr_p == save_expr))
3942 while (ret == GS_OK);
3944 /* If we encountered an error_mark somewhere nested inside, either
3945 stub out the statement or propagate the error back out. */
3946 if (ret == GS_ERROR)
3953 #ifdef ENABLE_CHECKING
3954 /* This was only valid as a return value from the langhook, which
3955 we handled. Make sure it doesn't escape from any other context. */
3956 if (ret == GS_UNHANDLED)
3960 if (fallback == fb_none && *expr_p && !is_gimple_stmt (*expr_p))
3962 /* We aren't looking for a value, and we don't have a valid
3963 statement. If it doesn't have side-effects, throw it away. */
3964 if (!TREE_SIDE_EFFECTS (*expr_p))
3966 else if (!TREE_THIS_VOLATILE (*expr_p))
3968 /* This is probably a _REF that contains something nested that
3969 has side effects. Recurse through the operands to find it. */
3970 enum tree_code code = TREE_CODE (*expr_p);
3972 if (code == COMPONENT_REF
3973 || code == REALPART_EXPR || code == IMAGPART_EXPR)
3974 gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p, post_p,
3975 gimple_test_f, fallback);
3976 else if (code == ARRAY_REF || code == ARRAY_RANGE_REF)
3978 gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p, post_p,
3979 gimple_test_f, fallback);
3980 gimplify_expr (&TREE_OPERAND (*expr_p, 1), pre_p, post_p,
3981 gimple_test_f, fallback);
3984 /* Anything else with side-effects
3985 must be converted to a valid statement before we get here. */
3990 else if (COMPLETE_TYPE_P (TREE_TYPE (*expr_p)))
3992 /* Historically, the compiler has treated a bare
3993 reference to a volatile lvalue as forcing a load. */
3994 tree tmp = create_tmp_var (TREE_TYPE (*expr_p), "vol");
3995 *expr_p = build (MODIFY_EXPR, TREE_TYPE (tmp), tmp, *expr_p);
3998 /* We can't do anything useful with a volatile reference to
3999 incomplete type, so just throw it away. */
4003 /* If we are gimplifying at the statement level, we're done. Tack
4004 everything together and replace the original statement with the
4006 if (fallback == fb_none || is_statement)
4008 if (internal_pre || internal_post)
4010 append_to_statement_list (*expr_p, &internal_pre);
4011 append_to_statement_list (internal_post, &internal_pre);
4012 annotate_all_with_locus (&internal_pre, input_location);
4013 *expr_p = internal_pre;
4017 else if (TREE_CODE (*expr_p) == STATEMENT_LIST)
4018 annotate_all_with_locus (expr_p, input_location);
4020 annotate_one_with_locus (*expr_p, input_location);
4024 /* Otherwise we're gimplifying a subexpression, so the resulting value is
4027 /* If it's sufficiently simple already, we're done. Unless we are
4028 handling some post-effects internally; if that's the case, we need to
4029 copy into a temp before adding the post-effects to the tree. */
4030 if (!internal_post && (*gimple_test_f) (*expr_p))
4033 /* Otherwise, we need to create a new temporary for the gimplified
4036 /* We can't return an lvalue if we have an internal postqueue. The
4037 object the lvalue refers to would (probably) be modified by the
4038 postqueue; we need to copy the value out first, which means an
4040 if ((fallback & fb_lvalue) && !internal_post
4041 && is_gimple_addressable (*expr_p))
4043 /* An lvalue will do. Take the address of the expression, store it
4044 in a temporary, and replace the expression with an INDIRECT_REF of
4046 tmp = build_fold_addr_expr (*expr_p);
4047 gimplify_expr (&tmp, pre_p, post_p, is_gimple_reg, fb_rvalue);
4048 *expr_p = build1 (INDIRECT_REF, TREE_TYPE (TREE_TYPE (tmp)), tmp);
4050 else if ((fallback & fb_rvalue) && is_gimple_formal_tmp_rhs (*expr_p))
4052 #if defined ENABLE_CHECKING
4053 if (VOID_TYPE_P (TREE_TYPE (*expr_p)))
4057 /* An rvalue will do. Assign the gimplified expression into a new
4058 temporary TMP and replace the original expression with TMP. */
4060 if (internal_post || (fallback & fb_lvalue))
4061 /* The postqueue might change the value of the expression between
4062 the initialization and use of the temporary, so we can't use a
4063 formal temp. FIXME do we care? */
4064 *expr_p = get_initialized_tmp_var (*expr_p, pre_p, post_p);
4066 *expr_p = get_formal_tmp_var (*expr_p, pre_p);
4068 if (TREE_CODE (*expr_p) != SSA_NAME)
4069 DECL_GIMPLE_FORMAL_TEMP_P (*expr_p) = 1;
4071 else if (fallback & fb_mayfail)
4073 /* If this is an asm statement, and the user asked for the impossible,
4074 don't abort. Fail and let gimplify_asm_expr issue an error. */
4080 fprintf (stderr, "gimplification failed:\n");
4081 print_generic_expr (stderr, *expr_p, 0);
4082 debug_tree (*expr_p);
4086 #if defined ENABLE_CHECKING
4087 /* Make sure the temporary matches our predicate. */
4088 if (!(*gimple_test_f) (*expr_p))
4094 annotate_all_with_locus (&internal_post, input_location);
4095 append_to_statement_list (internal_post, pre_p);
4099 input_location = saved_location;
4103 /* Look through TYPE for variable-sized objects and gimplify each such
4104 size that we find. Add to LIST_P any statements generated. */
4107 gimplify_type_sizes (tree type, tree *list_p)
4111 switch (TREE_CODE (type))
4121 gimplify_one_sizepos (&TYPE_MIN_VALUE (type), list_p);
4122 gimplify_one_sizepos (&TYPE_MAX_VALUE (type), list_p);
4126 /* These anonymous types don't have declarations, so handle them here. */
4127 gimplify_type_sizes (TYPE_DOMAIN (type), list_p);
4132 case QUAL_UNION_TYPE:
4133 for (field = TYPE_FIELDS (type); field; field = TREE_CHAIN (field))
4134 if (TREE_CODE (field) == FIELD_DECL)
4135 gimplify_one_sizepos (&DECL_FIELD_OFFSET (field), list_p);
4142 gimplify_one_sizepos (&TYPE_SIZE (type), list_p);
4143 gimplify_one_sizepos (&TYPE_SIZE_UNIT (type), list_p);
4146 /* Subroutine of the above to gimplify one size or position, *EXPR_P.
4147 We add any required statements to STMT_P. */
4150 gimplify_one_sizepos (tree *expr_p, tree *stmt_p)
4152 /* We don't do anything if the value isn't there, is constant, or contains
4153 A PLACEHOLDER_EXPR. We also don't want to do anything if it's already
4154 a VAR_DECL. If it's a VAR_DECL from another function, the gimplfier
4155 will want to replace it with a new variable, but that will cause problems
4156 if this type is from outside the function. It's OK to have that here. */
4157 if (*expr_p == NULL_TREE || TREE_CONSTANT (*expr_p)
4158 || TREE_CODE (*expr_p) == VAR_DECL
4159 || CONTAINS_PLACEHOLDER_P (*expr_p))
4162 gimplify_expr (expr_p, stmt_p, NULL, is_gimple_val, fb_rvalue);
4165 #ifdef ENABLE_CHECKING
4166 /* Compare types A and B for a "close enough" match. */
4169 cpt_same_type (tree a, tree b)
4171 if (lang_hooks.types_compatible_p (a, b))
4174 /* ??? The C++ FE decomposes METHOD_TYPES to FUNCTION_TYPES and doesn't
4175 link them together. This routine is intended to catch type errors
4176 that will affect the optimizers, and the optimizers don't add new
4177 dereferences of function pointers, so ignore it. */
4178 if ((TREE_CODE (a) == FUNCTION_TYPE || TREE_CODE (a) == METHOD_TYPE)
4179 && (TREE_CODE (b) == FUNCTION_TYPE || TREE_CODE (b) == METHOD_TYPE))
4182 /* ??? The C FE pushes type qualifiers after the fact into the type of
4183 the element from the type of the array. See build_unary_op's handling
4184 of ADDR_EXPR. This seems wrong -- if we were going to do this, we
4185 should have done it when creating the variable in the first place.
4186 Alternately, why aren't the two array types made variants? */
4187 if (TREE_CODE (a) == ARRAY_TYPE && TREE_CODE (b) == ARRAY_TYPE)
4188 return cpt_same_type (TREE_TYPE (a), TREE_TYPE (b));
4190 /* And because of those, we have to recurse down through pointers. */
4191 if (POINTER_TYPE_P (a) && POINTER_TYPE_P (b))
4192 return cpt_same_type (TREE_TYPE (a), TREE_TYPE (b));
4197 /* Check for some cases of the front end missing cast expressions.
4198 The type of a dereference should correspond to the pointer type;
4199 similarly the type of an address should match its object. */
4202 check_pointer_types_r (tree *tp, int *walk_subtrees ATTRIBUTE_UNUSED,
4203 void *data ATTRIBUTE_UNUSED)
4206 tree ptype, otype, dtype;
4208 switch (TREE_CODE (t))
4212 otype = TREE_TYPE (t);
4213 ptype = TREE_TYPE (TREE_OPERAND (t, 0));
4214 dtype = TREE_TYPE (ptype);
4215 if (!cpt_same_type (otype, dtype))
4220 ptype = TREE_TYPE (t);
4221 otype = TREE_TYPE (TREE_OPERAND (t, 0));
4222 dtype = TREE_TYPE (ptype);
4223 if (!cpt_same_type (otype, dtype))
4225 /* &array is allowed to produce a pointer to the element, rather than
4226 a pointer to the array type. We must allow this in order to
4227 properly represent assigning the address of an array in C into
4228 pointer to the element type. */
4229 if (TREE_CODE (otype) == ARRAY_TYPE
4230 && POINTER_TYPE_P (ptype)
4231 && cpt_same_type (TREE_TYPE (otype), dtype))
4246 /* Gimplify the body of statements pointed by BODY_P. FNDECL is the
4247 function decl containing BODY. */
4250 gimplify_body (tree *body_p, tree fndecl)
4252 location_t saved_location = input_location;
4255 timevar_push (TV_TREE_GIMPLIFY);
4256 push_gimplify_context ();
4258 /* Unshare most shared trees in the body and in that of any nested functions.
4259 It would seem we don't have to do this for nested functions because
4260 they are supposed to be output and then the outer function gimplified
4261 first, but the g++ front end doesn't always do it that way. */
4262 unshare_body (body_p, fndecl);
4263 unvisit_body (body_p, fndecl);
4265 /* Make sure input_location isn't set to something wierd. */
4266 input_location = DECL_SOURCE_LOCATION (fndecl);
4268 /* Gimplify the function's body. */
4269 gimplify_stmt (body_p);
4272 /* Unshare again, in case gimplification was sloppy. */
4273 unshare_all_trees (body);
4276 body = alloc_stmt_list ();
4277 else if (TREE_CODE (body) == STATEMENT_LIST)
4279 tree t = expr_only (*body_p);
4284 /* If there isn't an outer BIND_EXPR, add one. */
4285 if (TREE_CODE (body) != BIND_EXPR)
4287 tree b = build (BIND_EXPR, void_type_node, NULL_TREE,
4288 NULL_TREE, NULL_TREE);
4289 TREE_SIDE_EFFECTS (b) = 1;
4290 append_to_statement_list_force (body, &BIND_EXPR_BODY (b));
4295 pop_gimplify_context (body);
4297 #ifdef ENABLE_CHECKING
4298 walk_tree (body_p, check_pointer_types_r, NULL, NULL);
4301 timevar_pop (TV_TREE_GIMPLIFY);
4302 input_location = saved_location;
4305 /* Entry point to the gimplification pass. FNDECL is the FUNCTION_DECL
4306 node for the function we want to gimplify. */
4309 gimplify_function_tree (tree fndecl)
4313 oldfn = current_function_decl;
4314 current_function_decl = fndecl;
4316 gimplify_body (&DECL_SAVED_TREE (fndecl), fndecl);
4318 /* If we're instrumenting function entry/exit, then prepend the call to
4319 the entry hook and wrap the whole function in a TRY_FINALLY_EXPR to
4320 catch the exit hook. */
4321 /* ??? Add some way to ignore exceptions for this TFE. */
4322 if (flag_instrument_function_entry_exit
4323 && ! DECL_NO_INSTRUMENT_FUNCTION_ENTRY_EXIT (fndecl))
4327 tf = build (TRY_FINALLY_EXPR, void_type_node, NULL, NULL);
4328 TREE_SIDE_EFFECTS (tf) = 1;
4329 x = DECL_SAVED_TREE (fndecl);
4330 append_to_statement_list (x, &TREE_OPERAND (tf, 0));
4331 x = implicit_built_in_decls[BUILT_IN_PROFILE_FUNC_EXIT];
4332 x = build_function_call_expr (x, NULL);
4333 append_to_statement_list (x, &TREE_OPERAND (tf, 1));
4335 bind = build (BIND_EXPR, void_type_node, NULL, NULL, NULL);
4336 TREE_SIDE_EFFECTS (bind) = 1;
4337 x = implicit_built_in_decls[BUILT_IN_PROFILE_FUNC_ENTER];
4338 x = build_function_call_expr (x, NULL);
4339 append_to_statement_list (x, &BIND_EXPR_BODY (bind));
4340 append_to_statement_list (tf, &BIND_EXPR_BODY (bind));
4342 DECL_SAVED_TREE (fndecl) = bind;
4345 current_function_decl = oldfn;
4349 /* Expands EXPR to list of gimple statements STMTS. If SIMPLE is true,
4350 force the result to be either ssa_name or an invariant, otherwise
4351 just force it to be a rhs expression. If VAR is not NULL, make the
4352 base variable of the final destination be VAR if suitable. */
4355 force_gimple_operand (tree expr, tree *stmts, bool simple, tree var)
4358 enum gimplify_status ret;
4359 gimple_predicate gimple_test_f;
4363 if (is_gimple_val (expr))
4366 gimple_test_f = simple ? is_gimple_val : is_gimple_reg_rhs;
4368 push_gimplify_context ();
4369 gimplify_ctxp->into_ssa = true;
4372 expr = build (MODIFY_EXPR, TREE_TYPE (var), var, expr);
4374 ret = gimplify_expr (&expr, stmts, NULL,
4375 gimple_test_f, fb_rvalue);
4376 if (ret == GS_ERROR)
4379 for (t = gimplify_ctxp->temps; t ; t = TREE_CHAIN (t))
4380 add_referenced_tmp_var (t);
4382 pop_gimplify_context (NULL);
4387 #include "gt-gimplify.h"