1 /* Tree lowering pass. This pass converts the GENERIC functions-as-trees
2 tree representation into the GIMPLE form.
3 Copyright (C) 2002, 2003, 2004 Free Software Foundation, Inc.
4 Major work done by Sebastian Pop <s.pop@laposte.net>,
5 Diego Novillo <dnovillo@redhat.com> and Jason Merrill <jason@redhat.com>.
7 This file is part of GCC.
9 GCC is free software; you can redistribute it and/or modify it under
10 the terms of the GNU General Public License as published by the Free
11 Software Foundation; either version 2, or (at your option) any later
14 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
15 WARRANTY; without even the implied warranty of MERCHANTABILITY or
16 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
19 You should have received a copy of the GNU General Public License
20 along with GCC; see the file COPYING. If not, write to the Free
21 Software Foundation, 59 Temple Place - Suite 330, Boston, MA
26 #include "coretypes.h"
32 #include "tree-gimple.h"
33 #include "tree-inline.h"
34 #include "diagnostic.h"
35 #include "langhooks.h"
36 #include "langhooks-def.h"
37 #include "tree-flow.h"
50 static struct gimplify_ctx
52 tree current_bind_expr;
54 tree conditional_cleanups;
57 varray_type case_labels;
58 /* The formal temporary table. Should this be persistent? */
66 /* Formal (expression) temporary table handling: Multiple occurrences of
67 the same scalar expression are evaluated into the same temporary. */
69 typedef struct gimple_temp_hash_elt
72 tree temp; /* Value */
75 /* Forward declarations. */
76 static enum gimplify_status gimplify_compound_expr (tree *, tree *, bool);
77 #ifdef ENABLE_CHECKING
78 static bool cpt_same_type (tree a, tree b);
82 /* Return a hash value for a formal temporary table entry. */
85 gimple_tree_hash (const void *p)
87 tree t = ((const elt_t *) p)->val;
88 return iterative_hash_expr (t, 0);
91 /* Compare two formal temporary table entries. */
94 gimple_tree_eq (const void *p1, const void *p2)
96 tree t1 = ((const elt_t *) p1)->val;
97 tree t2 = ((const elt_t *) p2)->val;
98 enum tree_code code = TREE_CODE (t1);
100 if (TREE_CODE (t2) != code
101 || TREE_TYPE (t1) != TREE_TYPE (t2))
104 if (!operand_equal_p (t1, t2, 0))
107 /* Only allow them to compare equal if they also hash equal; otherwise
108 results are nondeterminate, and we fail bootstrap comparison. */
109 gcc_assert (gimple_tree_hash (p1) == gimple_tree_hash (p2));
114 /* Set up a context for the gimplifier. */
117 push_gimplify_context (void)
119 gcc_assert (!gimplify_ctxp);
121 = (struct gimplify_ctx *) xcalloc (1, sizeof (struct gimplify_ctx));
123 gimplify_ctxp->temp_htab
124 = htab_create (1000, gimple_tree_hash, gimple_tree_eq, free);
126 gimplify_ctxp->temp_htab = NULL;
129 /* Tear down a context for the gimplifier. If BODY is non-null, then
130 put the temporaries into the outer BIND_EXPR. Otherwise, put them
131 in the unexpanded_var_list. */
134 pop_gimplify_context (tree body)
138 gcc_assert (gimplify_ctxp && !gimplify_ctxp->current_bind_expr);
140 for (t = gimplify_ctxp->temps; t ; t = TREE_CHAIN (t))
141 DECL_GIMPLE_FORMAL_TEMP_P (t) = 0;
144 declare_tmp_vars (gimplify_ctxp->temps, body);
146 record_vars (gimplify_ctxp->temps);
149 if (!quiet_flag && optimize)
150 fprintf (stderr, " collisions: %f ",
151 htab_collisions (gimplify_ctxp->temp_htab));
155 htab_delete (gimplify_ctxp->temp_htab);
156 free (gimplify_ctxp);
157 gimplify_ctxp = NULL;
161 gimple_push_bind_expr (tree bind)
163 TREE_CHAIN (bind) = gimplify_ctxp->current_bind_expr;
164 gimplify_ctxp->current_bind_expr = bind;
168 gimple_pop_bind_expr (void)
170 gimplify_ctxp->current_bind_expr
171 = TREE_CHAIN (gimplify_ctxp->current_bind_expr);
175 gimple_current_bind_expr (void)
177 return gimplify_ctxp->current_bind_expr;
180 /* Returns true iff there is a COND_EXPR between us and the innermost
181 CLEANUP_POINT_EXPR. This info is used by gimple_push_cleanup. */
184 gimple_conditional_context (void)
186 return gimplify_ctxp->conditions > 0;
189 /* Note that we've entered a COND_EXPR. */
192 gimple_push_condition (void)
194 #ifdef ENABLE_CHECKING
195 if (gimplify_ctxp->conditions == 0)
196 gcc_assert (!gimplify_ctxp->conditional_cleanups);
198 ++(gimplify_ctxp->conditions);
201 /* Note that we've left a COND_EXPR. If we're back at unconditional scope
202 now, add any conditional cleanups we've seen to the prequeue. */
205 gimple_pop_condition (tree *pre_p)
207 int conds = --(gimplify_ctxp->conditions);
209 gcc_assert (conds >= 0);
212 append_to_statement_list (gimplify_ctxp->conditional_cleanups, pre_p);
213 gimplify_ctxp->conditional_cleanups = NULL_TREE;
217 /* A subroutine of append_to_statement_list{,_force}. */
220 append_to_statement_list_1 (tree t, tree *list_p, bool side_effects)
223 tree_stmt_iterator i;
230 if (t && TREE_CODE (t) == STATEMENT_LIST)
235 *list_p = list = alloc_stmt_list ();
239 tsi_link_after (&i, t, TSI_CONTINUE_LINKING);
242 /* Add T to the end of the list container pointed by LIST_P.
243 If T is an expression with no effects, it is ignored. */
246 append_to_statement_list (tree t, tree *list_p)
248 append_to_statement_list_1 (t, list_p, t ? TREE_SIDE_EFFECTS (t) : false);
251 /* Similar, but the statement is always added, regardless of side effects. */
254 append_to_statement_list_force (tree t, tree *list_p)
256 append_to_statement_list_1 (t, list_p, t != NULL);
259 /* Both gimplify the statement T and append it to LIST_P. */
262 gimplify_and_add (tree t, tree *list_p)
265 append_to_statement_list (t, list_p);
268 /* Strip off a legitimate source ending from the input string NAME of
269 length LEN. Rather than having to know the names used by all of
270 our front ends, we strip off an ending of a period followed by
271 up to five characters. (Java uses ".class".) */
274 remove_suffix (char *name, int len)
278 for (i = 2; i < 8 && len > i; i++)
280 if (name[len - i] == '.')
282 name[len - i] = '\0';
288 /* Create a nameless artificial label and put it in the current function
289 context. Returns the newly created label. */
292 create_artificial_label (void)
294 tree lab = build_decl (LABEL_DECL, NULL_TREE, void_type_node);
296 DECL_ARTIFICIAL (lab) = 1;
297 DECL_CONTEXT (lab) = current_function_decl;
301 /* Create a new temporary name with PREFIX. Returns an identifier. */
303 static GTY(()) unsigned int tmp_var_id_num;
306 create_tmp_var_name (const char *prefix)
312 char *preftmp = ASTRDUP (prefix);
314 remove_suffix (preftmp, strlen (preftmp));
318 ASM_FORMAT_PRIVATE_NAME (tmp_name, prefix ? prefix : "T", tmp_var_id_num++);
319 return get_identifier (tmp_name);
323 /* Create a new temporary variable declaration of type TYPE.
324 Does NOT push it into the current binding. */
327 create_tmp_var_raw (tree type, const char *prefix)
332 /* Make the type of the variable writable. */
333 new_type = build_type_variant (type, 0, 0);
334 TYPE_ATTRIBUTES (new_type) = TYPE_ATTRIBUTES (type);
336 tmp_var = build_decl (VAR_DECL, prefix ? create_tmp_var_name (prefix) : NULL,
339 /* The variable was declared by the compiler. */
340 DECL_ARTIFICIAL (tmp_var) = 1;
341 /* And we don't want debug info for it. */
342 DECL_IGNORED_P (tmp_var) = 1;
344 /* Make the variable writable. */
345 TREE_READONLY (tmp_var) = 0;
347 DECL_EXTERNAL (tmp_var) = 0;
348 TREE_STATIC (tmp_var) = 0;
349 TREE_USED (tmp_var) = 1;
354 /* Create a new temporary variable declaration of type TYPE. DOES push the
355 variable into the current binding. Further, assume that this is called
356 only from gimplification or optimization, at which point the creation of
357 certain types are bugs. */
360 create_tmp_var (tree type, const char *prefix)
364 /* We don't allow types that are addressable (meaning we can't make copies),
365 incomplete, or of variable size. */
366 gcc_assert (!TREE_ADDRESSABLE (type)
367 && COMPLETE_TYPE_P (type)
368 && TREE_CODE (TYPE_SIZE_UNIT (type)) == INTEGER_CST);
370 tmp_var = create_tmp_var_raw (type, prefix);
371 gimple_add_tmp_var (tmp_var);
375 /* Given a tree, try to return a useful variable name that we can use
376 to prefix a temporary that is being assigned the value of the tree.
377 I.E. given <temp> = &A, return A. */
385 STRIP_NOPS (stripped_decl);
386 if (DECL_P (stripped_decl) && DECL_NAME (stripped_decl))
387 return IDENTIFIER_POINTER (DECL_NAME (stripped_decl));
390 switch (TREE_CODE (stripped_decl))
393 return get_name (TREE_OPERAND (stripped_decl, 0));
401 /* Create a temporary with a name derived from VAL. Subroutine of
402 lookup_tmp_var; nobody else should call this function. */
405 create_tmp_from_val (tree val)
407 return create_tmp_var (TREE_TYPE (val), get_name (val));
410 /* Create a temporary to hold the value of VAL. If IS_FORMAL, try to reuse
411 an existing expression temporary. */
414 lookup_tmp_var (tree val, bool is_formal)
418 /* If not optimizing, never really reuse a temporary. local-alloc
419 won't allocate any variable that is used in more than one basic
420 block, which means it will go into memory, causing much extra
421 work in reload and final and poorer code generation, outweighing
422 the extra memory allocation here. */
423 if (!optimize || !is_formal || TREE_SIDE_EFFECTS (val))
424 ret = create_tmp_from_val (val);
431 slot = htab_find_slot (gimplify_ctxp->temp_htab, (void *)&elt, INSERT);
434 elt_p = xmalloc (sizeof (*elt_p));
436 elt_p->temp = ret = create_tmp_from_val (val);
437 *slot = (void *) elt_p;
441 elt_p = (elt_t *) *slot;
447 DECL_GIMPLE_FORMAL_TEMP_P (ret) = 1;
452 /* Returns a formal temporary variable initialized with VAL. PRE_P is as
453 in gimplify_expr. Only use this function if:
455 1) The value of the unfactored expression represented by VAL will not
456 change between the initialization and use of the temporary, and
457 2) The temporary will not be otherwise modified.
459 For instance, #1 means that this is inappropriate for SAVE_EXPR temps,
460 and #2 means it is inappropriate for && temps.
462 For other cases, use get_initialized_tmp_var instead. */
465 internal_get_tmp_var (tree val, tree *pre_p, tree *post_p, bool is_formal)
469 gimplify_expr (&val, pre_p, post_p, is_gimple_formal_tmp_rhs, fb_rvalue);
471 t = lookup_tmp_var (val, is_formal);
473 mod = build (MODIFY_EXPR, TREE_TYPE (t), t, val);
475 if (EXPR_HAS_LOCATION (val))
476 SET_EXPR_LOCUS (mod, EXPR_LOCUS (val));
478 SET_EXPR_LOCATION (mod, input_location);
480 /* gimplify_modify_expr might want to reduce this further. */
481 gimplify_and_add (mod, pre_p);
483 /* If we're gimplifying into ssa, gimplify_modify_expr will have
484 given our temporary an ssa name. Find and return it. */
485 if (gimplify_ctxp->into_ssa)
486 t = TREE_OPERAND (mod, 0);
492 get_formal_tmp_var (tree val, tree *pre_p)
494 return internal_get_tmp_var (val, pre_p, NULL, true);
497 /* Returns a temporary variable initialized with VAL. PRE_P and POST_P
498 are as in gimplify_expr. */
501 get_initialized_tmp_var (tree val, tree *pre_p, tree *post_p)
503 return internal_get_tmp_var (val, pre_p, post_p, false);
506 /* Declares all the variables in VARS in SCOPE. */
509 declare_tmp_vars (tree vars, tree scope)
516 /* C99 mode puts the default 'return 0;' for main outside the outer
517 braces. So drill down until we find an actual scope. */
518 while (TREE_CODE (scope) == COMPOUND_EXPR)
519 scope = TREE_OPERAND (scope, 0);
521 gcc_assert (TREE_CODE (scope) == BIND_EXPR);
523 temps = nreverse (last);
524 TREE_CHAIN (last) = BIND_EXPR_VARS (scope);
525 BIND_EXPR_VARS (scope) = temps;
530 gimple_add_tmp_var (tree tmp)
532 gcc_assert (!TREE_CHAIN (tmp) && !DECL_SEEN_IN_BIND_EXPR_P (tmp));
534 DECL_CONTEXT (tmp) = current_function_decl;
535 DECL_SEEN_IN_BIND_EXPR_P (tmp) = 1;
539 TREE_CHAIN (tmp) = gimplify_ctxp->temps;
540 gimplify_ctxp->temps = tmp;
545 declare_tmp_vars (tmp, DECL_SAVED_TREE (current_function_decl));
548 /* Determines whether to assign a locus to the statement STMT. */
551 should_carry_locus_p (tree stmt)
553 /* Don't emit a line note for a label. We particularly don't want to
554 emit one for the break label, since it doesn't actually correspond
555 to the beginning of the loop/switch. */
556 if (TREE_CODE (stmt) == LABEL_EXPR)
559 /* Do not annotate empty statements, since it confuses gcov. */
560 if (!TREE_SIDE_EFFECTS (stmt))
567 annotate_one_with_locus (tree t, location_t locus)
569 if (EXPR_P (t) && ! EXPR_HAS_LOCATION (t) && should_carry_locus_p (t))
570 SET_EXPR_LOCATION (t, locus);
574 annotate_all_with_locus (tree *stmt_p, location_t locus)
576 tree_stmt_iterator i;
581 for (i = tsi_start (*stmt_p); !tsi_end_p (i); tsi_next (&i))
583 tree t = tsi_stmt (i);
585 /* Assuming we've already been gimplified, we shouldn't
586 see nested chaining constructs anymore. */
587 gcc_assert (TREE_CODE (t) != STATEMENT_LIST
588 && TREE_CODE (t) != COMPOUND_EXPR);
590 annotate_one_with_locus (t, locus);
594 /* Similar to copy_tree_r() but do not copy SAVE_EXPR or TARGET_EXPR nodes.
595 These nodes model computations that should only be done once. If we
596 were to unshare something like SAVE_EXPR(i++), the gimplification
597 process would create wrong code. */
600 mostly_copy_tree_r (tree *tp, int *walk_subtrees, void *data)
602 enum tree_code code = TREE_CODE (*tp);
603 /* Don't unshare types, decls, constants and SAVE_EXPR nodes. */
604 if (TREE_CODE_CLASS (code) == tcc_type
605 || TREE_CODE_CLASS (code) == tcc_declaration
606 || TREE_CODE_CLASS (code) == tcc_constant
607 || code == SAVE_EXPR || code == TARGET_EXPR
608 /* We can't do anything sensible with a BLOCK used as an expression,
609 but we also can't abort when we see it because of non-expression
610 uses. So just avert our eyes and cross our fingers. Silly Java. */
615 gcc_assert (code != BIND_EXPR);
616 copy_tree_r (tp, walk_subtrees, data);
622 /* Callback for walk_tree to unshare most of the shared trees rooted at
623 *TP. If *TP has been visited already (i.e., TREE_VISITED (*TP) == 1),
624 then *TP is deep copied by calling copy_tree_r.
626 This unshares the same trees as copy_tree_r with the exception of
627 SAVE_EXPR nodes. These nodes model computations that should only be
628 done once. If we were to unshare something like SAVE_EXPR(i++), the
629 gimplification process would create wrong code. */
632 copy_if_shared_r (tree *tp, int *walk_subtrees ATTRIBUTE_UNUSED,
633 void *data ATTRIBUTE_UNUSED)
636 enum tree_code code = TREE_CODE (t);
638 /* Skip types, decls, and constants. But we do want to look at their
639 types and the bounds of types. Mark them as visited so we properly
640 unmark their subtrees on the unmark pass. If we've already seen them,
641 don't look down further. */
642 if (TREE_CODE_CLASS (code) == tcc_type
643 || TREE_CODE_CLASS (code) == tcc_declaration
644 || TREE_CODE_CLASS (code) == tcc_constant)
646 if (TREE_VISITED (t))
649 TREE_VISITED (t) = 1;
652 /* If this node has been visited already, unshare it and don't look
654 else if (TREE_VISITED (t))
656 walk_tree (tp, mostly_copy_tree_r, NULL, NULL);
660 /* Otherwise, mark the tree as visited and keep looking. */
662 TREE_VISITED (t) = 1;
668 unmark_visited_r (tree *tp, int *walk_subtrees ATTRIBUTE_UNUSED,
669 void *data ATTRIBUTE_UNUSED)
671 if (TREE_VISITED (*tp))
672 TREE_VISITED (*tp) = 0;
679 /* Unshare all the trees in BODY_P, a pointer into the body of FNDECL, and the
680 bodies of any nested functions if we are unsharing the entire body of
684 unshare_body (tree *body_p, tree fndecl)
686 struct cgraph_node *cgn = cgraph_node (fndecl);
688 walk_tree (body_p, copy_if_shared_r, NULL, NULL);
689 if (body_p == &DECL_SAVED_TREE (fndecl))
690 for (cgn = cgn->nested; cgn; cgn = cgn->next_nested)
691 unshare_body (&DECL_SAVED_TREE (cgn->decl), cgn->decl);
694 /* Likewise, but mark all trees as not visited. */
697 unvisit_body (tree *body_p, tree fndecl)
699 struct cgraph_node *cgn = cgraph_node (fndecl);
701 walk_tree (body_p, unmark_visited_r, NULL, NULL);
702 if (body_p == &DECL_SAVED_TREE (fndecl))
703 for (cgn = cgn->nested; cgn; cgn = cgn->next_nested)
704 unvisit_body (&DECL_SAVED_TREE (cgn->decl), cgn->decl);
707 /* Unshare T and all the trees reached from T via TREE_CHAIN. */
710 unshare_all_trees (tree t)
712 walk_tree (&t, copy_if_shared_r, NULL, NULL);
713 walk_tree (&t, unmark_visited_r, NULL, NULL);
716 /* Unconditionally make an unshared copy of EXPR. This is used when using
717 stored expressions which span multiple functions, such as BINFO_VTABLE,
718 as the normal unsharing process can't tell that they're shared. */
721 unshare_expr (tree expr)
723 walk_tree (&expr, mostly_copy_tree_r, NULL, NULL);
727 /* A terser interface for building a representation of an exception
731 gimple_build_eh_filter (tree body, tree allowed, tree failure)
735 /* FIXME should the allowed types go in TREE_TYPE? */
736 t = build (EH_FILTER_EXPR, void_type_node, allowed, NULL_TREE);
737 append_to_statement_list (failure, &EH_FILTER_FAILURE (t));
739 t = build (TRY_CATCH_EXPR, void_type_node, NULL_TREE, t);
740 append_to_statement_list (body, &TREE_OPERAND (t, 0));
746 /* WRAPPER is a code such as BIND_EXPR or CLEANUP_POINT_EXPR which can both
747 contain statements and have a value. Assign its value to a temporary
748 and give it void_type_node. Returns the temporary, or NULL_TREE if
749 WRAPPER was already void. */
752 voidify_wrapper_expr (tree wrapper, tree temp)
754 if (!VOID_TYPE_P (TREE_TYPE (wrapper)))
756 tree *p, sub = wrapper;
759 /* Set p to point to the body of the wrapper. */
760 switch (TREE_CODE (sub))
763 /* For a BIND_EXPR, the body is operand 1. */
764 p = &BIND_EXPR_BODY (sub);
768 p = &TREE_OPERAND (sub, 0);
772 /* Advance to the last statement. Set all container types to void. */
773 if (TREE_CODE (*p) == STATEMENT_LIST)
775 tree_stmt_iterator i = tsi_last (*p);
776 p = tsi_end_p (i) ? NULL : tsi_stmt_ptr (i);
780 for (; TREE_CODE (*p) == COMPOUND_EXPR; p = &TREE_OPERAND (*p, 1))
782 TREE_SIDE_EFFECTS (*p) = 1;
783 TREE_TYPE (*p) = void_type_node;
787 if (p == NULL || IS_EMPTY_STMT (*p))
789 /* Look through exception handling. */
790 else if (TREE_CODE (*p) == TRY_FINALLY_EXPR
791 || TREE_CODE (*p) == TRY_CATCH_EXPR)
796 /* The C++ frontend already did this for us. */
797 else if (TREE_CODE (*p) == INIT_EXPR
798 || TREE_CODE (*p) == TARGET_EXPR)
799 temp = TREE_OPERAND (*p, 0);
800 /* If we're returning a dereference, move the dereference
801 outside the wrapper. */
802 else if (TREE_CODE (*p) == INDIRECT_REF)
804 tree ptr = TREE_OPERAND (*p, 0);
805 temp = create_tmp_var (TREE_TYPE (ptr), "retval");
806 *p = build (MODIFY_EXPR, TREE_TYPE (ptr), temp, ptr);
807 temp = build1 (INDIRECT_REF, TREE_TYPE (TREE_TYPE (temp)), temp);
808 /* If this is a BIND_EXPR for a const inline function, it might not
809 have TREE_SIDE_EFFECTS set. That is no longer accurate. */
810 TREE_SIDE_EFFECTS (wrapper) = 1;
815 temp = create_tmp_var (TREE_TYPE (wrapper), "retval");
816 *p = build (MODIFY_EXPR, TREE_TYPE (temp), temp, *p);
817 TREE_SIDE_EFFECTS (wrapper) = 1;
820 TREE_TYPE (wrapper) = void_type_node;
827 /* Prepare calls to builtins to SAVE and RESTORE the stack as well as
828 a temporary through which they communicate. */
831 build_stack_save_restore (tree *save, tree *restore)
833 tree save_call, tmp_var;
836 build_function_call_expr (implicit_built_in_decls[BUILT_IN_STACK_SAVE],
838 tmp_var = create_tmp_var (ptr_type_node, "saved_stack");
840 *save = build (MODIFY_EXPR, ptr_type_node, tmp_var, save_call);
842 build_function_call_expr (implicit_built_in_decls[BUILT_IN_STACK_RESTORE],
843 tree_cons (NULL_TREE, tmp_var, NULL_TREE));
846 /* Gimplify a BIND_EXPR. Just voidify and recurse. */
848 static enum gimplify_status
849 gimplify_bind_expr (tree *expr_p, tree temp, tree *pre_p)
851 tree bind_expr = *expr_p;
852 bool old_save_stack = gimplify_ctxp->save_stack;
855 temp = voidify_wrapper_expr (bind_expr, temp);
857 /* Mark variables seen in this bind expr. */
858 for (t = BIND_EXPR_VARS (bind_expr); t ; t = TREE_CHAIN (t))
859 DECL_SEEN_IN_BIND_EXPR_P (t) = 1;
861 gimple_push_bind_expr (bind_expr);
862 gimplify_ctxp->save_stack = false;
864 gimplify_to_stmt_list (&BIND_EXPR_BODY (bind_expr));
866 if (gimplify_ctxp->save_stack)
868 tree stack_save, stack_restore;
870 /* Save stack on entry and restore it on exit. Add a try_finally
871 block to achieve this. Note that mudflap depends on the
872 format of the emitted code: see mx_register_decls(). */
873 build_stack_save_restore (&stack_save, &stack_restore);
875 t = build (TRY_FINALLY_EXPR, void_type_node,
876 BIND_EXPR_BODY (bind_expr), NULL_TREE);
877 append_to_statement_list (stack_restore, &TREE_OPERAND (t, 1));
879 BIND_EXPR_BODY (bind_expr) = NULL_TREE;
880 append_to_statement_list (stack_save, &BIND_EXPR_BODY (bind_expr));
881 append_to_statement_list (t, &BIND_EXPR_BODY (bind_expr));
884 gimplify_ctxp->save_stack = old_save_stack;
885 gimple_pop_bind_expr ();
890 append_to_statement_list (bind_expr, pre_p);
897 /* Gimplify a RETURN_EXPR. If the expression to be returned is not a
898 GIMPLE value, it is assigned to a new temporary and the statement is
899 re-written to return the temporary.
901 PRE_P points to the list where side effects that must happen before
902 STMT should be stored. */
904 static enum gimplify_status
905 gimplify_return_expr (tree stmt, tree *pre_p)
907 tree ret_expr = TREE_OPERAND (stmt, 0);
908 tree result_decl, result;
910 if (!ret_expr || TREE_CODE (ret_expr) == RESULT_DECL
911 || ret_expr == error_mark_node)
914 if (VOID_TYPE_P (TREE_TYPE (TREE_TYPE (current_function_decl))))
915 result_decl = NULL_TREE;
918 result_decl = TREE_OPERAND (ret_expr, 0);
919 if (TREE_CODE (result_decl) == INDIRECT_REF)
920 /* See through a return by reference. */
921 result_decl = TREE_OPERAND (result_decl, 0);
923 gcc_assert ((TREE_CODE (ret_expr) == MODIFY_EXPR
924 || TREE_CODE (ret_expr) == INIT_EXPR)
925 && TREE_CODE (result_decl) == RESULT_DECL);
928 /* If aggregate_value_p is true, then we can return the bare RESULT_DECL.
929 Recall that aggregate_value_p is FALSE for any aggregate type that is
930 returned in registers. If we're returning values in registers, then
931 we don't want to extend the lifetime of the RESULT_DECL, particularly
932 across another call. In addition, for those aggregates for which
933 hard_function_value generates a PARALLEL, we'll abort during normal
934 expansion of structure assignments; there's special code in expand_return
935 to handle this case that does not exist in expand_expr. */
937 || aggregate_value_p (result_decl, TREE_TYPE (current_function_decl)))
938 result = result_decl;
939 else if (gimplify_ctxp->return_temp)
940 result = gimplify_ctxp->return_temp;
943 result = create_tmp_var (TREE_TYPE (result_decl), NULL);
945 /* ??? With complex control flow (usually involving abnormal edges),
946 we can wind up warning about an uninitialized value for this. Due
947 to how this variable is constructed and initialized, this is never
948 true. Give up and never warn. */
949 TREE_NO_WARNING (result) = 1;
951 gimplify_ctxp->return_temp = result;
954 /* Smash the lhs of the MODIFY_EXPR to the temporary we plan to use.
955 Then gimplify the whole thing. */
956 if (result != result_decl)
957 TREE_OPERAND (ret_expr, 0) = result;
959 gimplify_and_add (TREE_OPERAND (stmt, 0), pre_p);
961 /* If we didn't use a temporary, then the result is just the result_decl.
962 Otherwise we need a simple copy. This should already be gimple. */
963 if (result == result_decl)
966 ret_expr = build (MODIFY_EXPR, TREE_TYPE (result), result_decl, result);
967 TREE_OPERAND (stmt, 0) = ret_expr;
972 /* Gimplifies a DECL_EXPR node *STMT_P by making any necessary allocation
973 and initialization explicit. */
975 static enum gimplify_status
976 gimplify_decl_expr (tree *stmt_p)
979 tree decl = DECL_EXPR_DECL (stmt);
983 if (TREE_TYPE (decl) == error_mark_node)
986 else if (TREE_CODE (decl) == TYPE_DECL)
987 gimplify_type_sizes (TREE_TYPE (decl), stmt_p);
989 else if (TREE_CODE (decl) == VAR_DECL && !DECL_EXTERNAL (decl))
991 tree init = DECL_INITIAL (decl);
993 if (!TREE_CONSTANT (DECL_SIZE (decl)))
995 /* This is a variable-sized decl. Simplify its size and mark it
996 for deferred expansion. Note that mudflap depends on the format
997 of the emitted code: see mx_register_decls(). */
998 tree t, args, addr, ptr_type;
1000 gimplify_type_sizes (TREE_TYPE (decl), stmt_p);
1001 gimplify_one_sizepos (&DECL_SIZE (decl), stmt_p);
1002 gimplify_one_sizepos (&DECL_SIZE_UNIT (decl), stmt_p);
1004 /* All occurrences of this decl in final gimplified code will be
1005 replaced by indirection. Setting DECL_VALUE_EXPR does two
1006 things: First, it lets the rest of the gimplifier know what
1007 replacement to use. Second, it lets the debug info know
1008 where to find the value. */
1009 ptr_type = build_pointer_type (TREE_TYPE (decl));
1010 addr = create_tmp_var (ptr_type, get_name (decl));
1011 DECL_IGNORED_P (addr) = 0;
1012 t = build_fold_indirect_ref (addr);
1013 DECL_VALUE_EXPR (decl) = t;
1015 args = tree_cons (NULL, DECL_SIZE_UNIT (decl), NULL);
1016 t = built_in_decls[BUILT_IN_ALLOCA];
1017 t = build_function_call_expr (t, args);
1018 t = fold_convert (ptr_type, t);
1019 t = build2 (MODIFY_EXPR, void_type_node, addr, t);
1021 gimplify_and_add (t, stmt_p);
1023 /* Indicate that we need to restore the stack level when the
1024 enclosing BIND_EXPR is exited. */
1025 gimplify_ctxp->save_stack = true;
1028 if (init && init != error_mark_node)
1030 if (!TREE_STATIC (decl))
1032 DECL_INITIAL (decl) = NULL_TREE;
1033 init = build (MODIFY_EXPR, void_type_node, decl, init);
1034 gimplify_and_add (init, stmt_p);
1037 /* We must still examine initializers for static variables
1038 as they may contain a label address. */
1039 walk_tree (&init, force_labels_r, NULL, NULL);
1042 /* This decl isn't mentioned in the enclosing block, so add it to the
1043 list of temps. FIXME it seems a bit of a kludge to say that
1044 anonymous artificial vars aren't pushed, but everything else is. */
1045 if (DECL_ARTIFICIAL (decl) && DECL_NAME (decl) == NULL_TREE)
1046 gimple_add_tmp_var (decl);
1052 /* Gimplify a LOOP_EXPR. Normally this just involves gimplifying the body
1053 and replacing the LOOP_EXPR with goto, but if the loop contains an
1054 EXIT_EXPR, we need to append a label for it to jump to. */
1056 static enum gimplify_status
1057 gimplify_loop_expr (tree *expr_p, tree *pre_p)
1059 tree saved_label = gimplify_ctxp->exit_label;
1060 tree start_label = build1 (LABEL_EXPR, void_type_node, NULL_TREE);
1061 tree jump_stmt = build_and_jump (&LABEL_EXPR_LABEL (start_label));
1063 append_to_statement_list (start_label, pre_p);
1065 gimplify_ctxp->exit_label = NULL_TREE;
1067 gimplify_and_add (LOOP_EXPR_BODY (*expr_p), pre_p);
1069 if (gimplify_ctxp->exit_label)
1071 append_to_statement_list (jump_stmt, pre_p);
1072 *expr_p = build1 (LABEL_EXPR, void_type_node, gimplify_ctxp->exit_label);
1075 *expr_p = jump_stmt;
1077 gimplify_ctxp->exit_label = saved_label;
1082 /* Compare two case labels. Because the front end should already have
1083 made sure that case ranges do not overlap, it is enough to only compare
1084 the CASE_LOW values of each case label. */
1087 compare_case_labels (const void *p1, const void *p2)
1089 tree case1 = *(tree *)p1;
1090 tree case2 = *(tree *)p2;
1092 return tree_int_cst_compare (CASE_LOW (case1), CASE_LOW (case2));
1095 /* Sort the case labels in LABEL_VEC in place in ascending order. */
1098 sort_case_labels (tree label_vec)
1100 size_t len = TREE_VEC_LENGTH (label_vec);
1101 tree default_case = TREE_VEC_ELT (label_vec, len - 1);
1103 if (CASE_LOW (default_case))
1107 /* The last label in the vector should be the default case
1109 for (i = 0; i < len; ++i)
1111 tree t = TREE_VEC_ELT (label_vec, i);
1115 TREE_VEC_ELT (label_vec, i) = TREE_VEC_ELT (label_vec, len - 1);
1116 TREE_VEC_ELT (label_vec, len - 1) = default_case;
1122 qsort (&TREE_VEC_ELT (label_vec, 0), len - 1, sizeof (tree),
1123 compare_case_labels);
1126 /* Gimplify a SWITCH_EXPR, and collect a TREE_VEC of the labels it can
1129 static enum gimplify_status
1130 gimplify_switch_expr (tree *expr_p, tree *pre_p)
1132 tree switch_expr = *expr_p;
1133 enum gimplify_status ret;
1135 ret = gimplify_expr (&SWITCH_COND (switch_expr), pre_p, NULL,
1136 is_gimple_val, fb_rvalue);
1138 if (SWITCH_BODY (switch_expr))
1140 varray_type labels, saved_labels;
1141 tree label_vec, default_case = NULL_TREE;
1144 /* If someone can be bothered to fill in the labels, they can
1145 be bothered to null out the body too. */
1146 gcc_assert (!SWITCH_LABELS (switch_expr));
1148 saved_labels = gimplify_ctxp->case_labels;
1149 VARRAY_TREE_INIT (gimplify_ctxp->case_labels, 8, "case_labels");
1151 gimplify_to_stmt_list (&SWITCH_BODY (switch_expr));
1153 labels = gimplify_ctxp->case_labels;
1154 gimplify_ctxp->case_labels = saved_labels;
1156 len = VARRAY_ACTIVE_SIZE (labels);
1158 for (i = 0; i < len; ++i)
1160 tree t = VARRAY_TREE (labels, i);
1163 /* The default case must be the last label in the list. */
1165 VARRAY_TREE (labels, i) = VARRAY_TREE (labels, len - 1);
1171 label_vec = make_tree_vec (len + 1);
1172 SWITCH_LABELS (*expr_p) = label_vec;
1173 append_to_statement_list (switch_expr, pre_p);
1177 /* If the switch has no default label, add one, so that we jump
1178 around the switch body. */
1179 default_case = build (CASE_LABEL_EXPR, void_type_node, NULL_TREE,
1180 NULL_TREE, create_artificial_label ());
1181 append_to_statement_list (SWITCH_BODY (switch_expr), pre_p);
1182 *expr_p = build (LABEL_EXPR, void_type_node,
1183 CASE_LABEL (default_case));
1186 *expr_p = SWITCH_BODY (switch_expr);
1188 for (i = 0; i < len; ++i)
1189 TREE_VEC_ELT (label_vec, i) = VARRAY_TREE (labels, i);
1190 TREE_VEC_ELT (label_vec, len) = default_case;
1192 sort_case_labels (label_vec);
1194 SWITCH_BODY (switch_expr) = NULL;
1197 gcc_assert (SWITCH_LABELS (switch_expr));
1202 static enum gimplify_status
1203 gimplify_case_label_expr (tree *expr_p)
1205 tree expr = *expr_p;
1207 gcc_assert (gimplify_ctxp->case_labels);
1208 VARRAY_PUSH_TREE (gimplify_ctxp->case_labels, expr);
1209 *expr_p = build (LABEL_EXPR, void_type_node, CASE_LABEL (expr));
1213 /* Build a GOTO to the LABEL_DECL pointed to by LABEL_P, building it first
1217 build_and_jump (tree *label_p)
1219 if (label_p == NULL)
1220 /* If there's nowhere to jump, just fall through. */
1223 if (*label_p == NULL_TREE)
1225 tree label = create_artificial_label ();
1229 return build1 (GOTO_EXPR, void_type_node, *label_p);
1232 /* Gimplify an EXIT_EXPR by converting to a GOTO_EXPR inside a COND_EXPR.
1233 This also involves building a label to jump to and communicating it to
1234 gimplify_loop_expr through gimplify_ctxp->exit_label. */
1236 static enum gimplify_status
1237 gimplify_exit_expr (tree *expr_p)
1239 tree cond = TREE_OPERAND (*expr_p, 0);
1242 expr = build_and_jump (&gimplify_ctxp->exit_label);
1243 expr = build (COND_EXPR, void_type_node, cond, expr, NULL_TREE);
1249 /* A helper function to be called via walk_tree. Mark all labels under *TP
1250 as being forced. To be called for DECL_INITIAL of static variables. */
1253 force_labels_r (tree *tp, int *walk_subtrees, void *data ATTRIBUTE_UNUSED)
1257 if (TREE_CODE (*tp) == LABEL_DECL)
1258 FORCED_LABEL (*tp) = 1;
1263 /* *EXPR_P is a COMPONENT_REF being used as an rvalue. If its type is
1264 different from its canonical type, wrap the whole thing inside a
1265 NOP_EXPR and force the type of the COMPONENT_REF to be the canonical
1268 The canonical type of a COMPONENT_REF is the type of the field being
1269 referenced--unless the field is a bit-field which can be read directly
1270 in a smaller mode, in which case the canonical type is the
1271 sign-appropriate type corresponding to that mode. */
1274 canonicalize_component_ref (tree *expr_p)
1276 tree expr = *expr_p;
1279 gcc_assert (TREE_CODE (expr) == COMPONENT_REF);
1281 if (INTEGRAL_TYPE_P (TREE_TYPE (expr)))
1282 type = TREE_TYPE (get_unwidened (expr, NULL_TREE));
1284 type = TREE_TYPE (TREE_OPERAND (expr, 1));
1286 if (TREE_TYPE (expr) != type)
1288 tree old_type = TREE_TYPE (expr);
1290 /* Set the type of the COMPONENT_REF to the underlying type. */
1291 TREE_TYPE (expr) = type;
1293 /* And wrap the whole thing inside a NOP_EXPR. */
1294 expr = build1 (NOP_EXPR, old_type, expr);
1300 /* If a NOP conversion is changing a pointer to array of foo to a pointer
1301 to foo, embed that change in the ADDR_EXPR by converting
1306 where L is the lower bound. For simplicity, only do this for constant
1310 canonicalize_addr_expr (tree *expr_p)
1312 tree expr = *expr_p;
1313 tree ctype = TREE_TYPE (expr);
1314 tree addr_expr = TREE_OPERAND (expr, 0);
1315 tree atype = TREE_TYPE (addr_expr);
1316 tree dctype, datype, ddatype, otype, obj_expr;
1318 /* Both cast and addr_expr types should be pointers. */
1319 if (!POINTER_TYPE_P (ctype) || !POINTER_TYPE_P (atype))
1322 /* The addr_expr type should be a pointer to an array. */
1323 datype = TREE_TYPE (atype);
1324 if (TREE_CODE (datype) != ARRAY_TYPE)
1327 /* Both cast and addr_expr types should address the same object type. */
1328 dctype = TREE_TYPE (ctype);
1329 ddatype = TREE_TYPE (datype);
1330 if (!lang_hooks.types_compatible_p (ddatype, dctype))
1333 /* The addr_expr and the object type should match. */
1334 obj_expr = TREE_OPERAND (addr_expr, 0);
1335 otype = TREE_TYPE (obj_expr);
1336 if (!lang_hooks.types_compatible_p (otype, datype))
1339 /* The lower bound and element sizes must be constant. */
1340 if (TREE_CODE (TYPE_SIZE_UNIT (dctype)) != INTEGER_CST
1341 || !TYPE_DOMAIN (datype) || !TYPE_MIN_VALUE (TYPE_DOMAIN (datype))
1342 || TREE_CODE (TYPE_MIN_VALUE (TYPE_DOMAIN (datype))) != INTEGER_CST)
1345 /* All checks succeeded. Build a new node to merge the cast. */
1346 *expr_p = build4 (ARRAY_REF, dctype, obj_expr,
1347 TYPE_MIN_VALUE (TYPE_DOMAIN (datype)),
1348 TYPE_MIN_VALUE (TYPE_DOMAIN (datype)),
1349 size_binop (EXACT_DIV_EXPR, TYPE_SIZE_UNIT (dctype),
1350 size_int (TYPE_ALIGN_UNIT (dctype))));
1351 *expr_p = build1 (ADDR_EXPR, ctype, *expr_p);
1354 /* *EXPR_P is a NOP_EXPR or CONVERT_EXPR. Remove it and/or other conversions
1355 underneath as appropriate. */
1357 static enum gimplify_status
1358 gimplify_conversion (tree *expr_p)
1360 /* If we still have a conversion at the toplevel, then strip
1361 away all but the outermost conversion. */
1362 if (TREE_CODE (*expr_p) == NOP_EXPR || TREE_CODE (*expr_p) == CONVERT_EXPR)
1364 STRIP_SIGN_NOPS (TREE_OPERAND (*expr_p, 0));
1366 /* And remove the outermost conversion if it's useless. */
1367 if (tree_ssa_useless_type_conversion (*expr_p))
1368 *expr_p = TREE_OPERAND (*expr_p, 0);
1371 /* If we still have a conversion at the toplevel,
1372 then canonicalize some constructs. */
1373 if (TREE_CODE (*expr_p) == NOP_EXPR || TREE_CODE (*expr_p) == CONVERT_EXPR)
1375 tree sub = TREE_OPERAND (*expr_p, 0);
1377 /* If a NOP conversion is changing the type of a COMPONENT_REF
1378 expression, then canonicalize its type now in order to expose more
1379 redundant conversions. */
1380 if (TREE_CODE (sub) == COMPONENT_REF)
1381 canonicalize_component_ref (&TREE_OPERAND (*expr_p, 0));
1383 /* If a NOP conversion is changing a pointer to array of foo
1384 to a pointer to foo, embed that change in the ADDR_EXPR. */
1385 else if (TREE_CODE (sub) == ADDR_EXPR)
1386 canonicalize_addr_expr (expr_p);
1392 /* Gimplify the COMPONENT_REF, ARRAY_REF, REALPART_EXPR or IMAGPART_EXPR
1393 node pointed by EXPR_P.
1396 : min_lval '[' val ']'
1398 | compound_lval '[' val ']'
1399 | compound_lval '.' ID
1401 This is not part of the original SIMPLE definition, which separates
1402 array and member references, but it seems reasonable to handle them
1403 together. Also, this way we don't run into problems with union
1404 aliasing; gcc requires that for accesses through a union to alias, the
1405 union reference must be explicit, which was not always the case when we
1406 were splitting up array and member refs.
1408 PRE_P points to the list where side effects that must happen before
1409 *EXPR_P should be stored.
1411 POST_P points to the list where side effects that must happen after
1412 *EXPR_P should be stored. */
1414 static enum gimplify_status
1415 gimplify_compound_lval (tree *expr_p, tree *pre_p,
1416 tree *post_p, fallback_t fallback)
1420 enum gimplify_status ret = GS_OK, tret;
1423 /* Create a stack of the subexpressions so later we can walk them in
1424 order from inner to outer.
1426 This array is very memory consuming. Don't even think of making
1428 VARRAY_GENERIC_PTR_NOGC_INIT (stack, 10, "stack");
1430 /* We can handle anything that get_inner_reference can deal with. */
1431 for (p = expr_p; handled_component_p (*p); p = &TREE_OPERAND (*p, 0))
1432 VARRAY_PUSH_GENERIC_PTR_NOGC (stack, *p);
1434 gcc_assert (VARRAY_ACTIVE_SIZE (stack));
1436 /* Now STACK is a stack of pointers to all the refs we've walked through
1437 and P points to the innermost expression.
1439 Java requires that we elaborated nodes in source order. That
1440 means we must gimplify the inner expression followed by each of
1441 the indices, in order. But we can't gimplify the inner
1442 expression until we deal with any variable bounds, sizes, or
1443 positions in order to deal with PLACEHOLDER_EXPRs.
1445 So we do this in three steps. First we deal with the annotations
1446 for any variables in the components, then we gimplify the base,
1447 then we gimplify any indices, from left to right. */
1448 for (i = VARRAY_ACTIVE_SIZE (stack) - 1; i >= 0; i--)
1450 tree t = VARRAY_GENERIC_PTR_NOGC (stack, i);
1452 if (TREE_CODE (t) == ARRAY_REF || TREE_CODE (t) == ARRAY_RANGE_REF)
1454 /* Gimplify the low bound and element type size and put them into
1455 the ARRAY_REF. If these values are set, they have already been
1457 if (!TREE_OPERAND (t, 2))
1459 tree low = unshare_expr (array_ref_low_bound (t));
1460 if (!is_gimple_min_invariant (low))
1462 TREE_OPERAND (t, 2) = low;
1463 tret = gimplify_expr (&TREE_OPERAND (t, 2), pre_p, post_p,
1464 is_gimple_formal_tmp_reg, fb_rvalue);
1465 ret = MIN (ret, tret);
1469 if (!TREE_OPERAND (t, 3))
1471 tree elmt_type = TREE_TYPE (TREE_TYPE (TREE_OPERAND (t, 0)));
1472 tree elmt_size = unshare_expr (array_ref_element_size (t));
1473 tree factor = size_int (TYPE_ALIGN_UNIT (elmt_type));
1475 /* Divide the element size by the alignment of the element
1477 elmt_size = size_binop (EXACT_DIV_EXPR, elmt_size, factor);
1479 if (!is_gimple_min_invariant (elmt_size))
1481 TREE_OPERAND (t, 3) = elmt_size;
1482 tret = gimplify_expr (&TREE_OPERAND (t, 3), pre_p, post_p,
1483 is_gimple_formal_tmp_reg, fb_rvalue);
1484 ret = MIN (ret, tret);
1488 else if (TREE_CODE (t) == COMPONENT_REF)
1490 /* Set the field offset into T and gimplify it. */
1491 if (!TREE_OPERAND (t, 2))
1493 tree offset = unshare_expr (component_ref_field_offset (t));
1494 tree field = TREE_OPERAND (t, 1);
1496 = size_int (DECL_OFFSET_ALIGN (field) / BITS_PER_UNIT);
1498 /* Divide the offset by its alignment. */
1499 offset = size_binop (EXACT_DIV_EXPR, offset, factor);
1501 if (!is_gimple_min_invariant (offset))
1503 TREE_OPERAND (t, 2) = offset;
1504 tret = gimplify_expr (&TREE_OPERAND (t, 2), pre_p, post_p,
1505 is_gimple_formal_tmp_reg, fb_rvalue);
1506 ret = MIN (ret, tret);
1512 /* Step 2 is to gimplify the base expression. */
1513 tret = gimplify_expr (p, pre_p, post_p, is_gimple_min_lval, fallback);
1514 ret = MIN (ret, tret);
1516 /* And finally, the indices and operands to BIT_FIELD_REF. During this
1517 loop we also remove any useless conversions. */
1518 for (; VARRAY_ACTIVE_SIZE (stack) > 0; )
1520 tree t = VARRAY_TOP_TREE (stack);
1522 if (TREE_CODE (t) == ARRAY_REF || TREE_CODE (t) == ARRAY_RANGE_REF)
1524 /* Gimplify the dimension.
1525 Temporary fix for gcc.c-torture/execute/20040313-1.c.
1526 Gimplify non-constant array indices into a temporary
1528 FIXME - The real fix is to gimplify post-modify
1529 expressions into a minimal gimple lvalue. However, that
1530 exposes bugs in alias analysis. The alias analyzer does
1531 not handle &PTR->FIELD very well. Will fix after the
1532 branch is merged into mainline (dnovillo 2004-05-03). */
1533 if (!is_gimple_min_invariant (TREE_OPERAND (t, 1)))
1535 tret = gimplify_expr (&TREE_OPERAND (t, 1), pre_p, post_p,
1536 is_gimple_formal_tmp_reg, fb_rvalue);
1537 ret = MIN (ret, tret);
1540 else if (TREE_CODE (t) == BIT_FIELD_REF)
1542 tret = gimplify_expr (&TREE_OPERAND (t, 1), pre_p, post_p,
1543 is_gimple_val, fb_rvalue);
1544 ret = MIN (ret, tret);
1545 tret = gimplify_expr (&TREE_OPERAND (t, 2), pre_p, post_p,
1546 is_gimple_val, fb_rvalue);
1547 ret = MIN (ret, tret);
1550 STRIP_USELESS_TYPE_CONVERSION (TREE_OPERAND (t, 0));
1552 /* The innermost expression P may have originally had TREE_SIDE_EFFECTS
1553 set which would have caused all the outer expressions in EXPR_P
1554 leading to P to also have had TREE_SIDE_EFFECTS set. */
1555 recalculate_side_effects (t);
1559 tret = gimplify_expr (p, pre_p, post_p, is_gimple_min_lval, fallback);
1560 ret = MIN (ret, tret);
1562 /* If the outermost expression is a COMPONENT_REF, canonicalize its type. */
1563 if ((fallback & fb_rvalue) && TREE_CODE (*expr_p) == COMPONENT_REF)
1565 canonicalize_component_ref (expr_p);
1566 ret = MIN (ret, GS_OK);
1569 VARRAY_FREE (stack);
1574 /* Gimplify the self modifying expression pointed by EXPR_P (++, --, +=, -=).
1576 PRE_P points to the list where side effects that must happen before
1577 *EXPR_P should be stored.
1579 POST_P points to the list where side effects that must happen after
1580 *EXPR_P should be stored.
1582 WANT_VALUE is nonzero iff we want to use the value of this expression
1583 in another expression. */
1585 static enum gimplify_status
1586 gimplify_self_mod_expr (tree *expr_p, tree *pre_p, tree *post_p,
1589 enum tree_code code;
1590 tree lhs, lvalue, rhs, t1;
1592 enum tree_code arith_code;
1593 enum gimplify_status ret;
1595 code = TREE_CODE (*expr_p);
1597 gcc_assert (code == POSTINCREMENT_EXPR || code == POSTDECREMENT_EXPR
1598 || code == PREINCREMENT_EXPR || code == PREDECREMENT_EXPR);
1600 /* Prefix or postfix? */
1601 if (code == POSTINCREMENT_EXPR || code == POSTDECREMENT_EXPR)
1602 /* Faster to treat as prefix if result is not used. */
1603 postfix = want_value;
1607 /* Add or subtract? */
1608 if (code == PREINCREMENT_EXPR || code == POSTINCREMENT_EXPR)
1609 arith_code = PLUS_EXPR;
1611 arith_code = MINUS_EXPR;
1613 /* Gimplify the LHS into a GIMPLE lvalue. */
1614 lvalue = TREE_OPERAND (*expr_p, 0);
1615 ret = gimplify_expr (&lvalue, pre_p, post_p, is_gimple_lvalue, fb_lvalue);
1616 if (ret == GS_ERROR)
1619 /* Extract the operands to the arithmetic operation. */
1621 rhs = TREE_OPERAND (*expr_p, 1);
1623 /* For postfix operator, we evaluate the LHS to an rvalue and then use
1624 that as the result value and in the postqueue operation. */
1627 ret = gimplify_expr (&lhs, pre_p, post_p, is_gimple_val, fb_rvalue);
1628 if (ret == GS_ERROR)
1632 t1 = build (arith_code, TREE_TYPE (*expr_p), lhs, rhs);
1633 t1 = build (MODIFY_EXPR, TREE_TYPE (lvalue), lvalue, t1);
1637 gimplify_and_add (t1, post_p);
1648 /* If *EXPR_P has a variable sized type, wrap it in a WITH_SIZE_EXPR. */
1651 maybe_with_size_expr (tree *expr_p)
1653 tree expr = *expr_p;
1654 tree type = TREE_TYPE (expr);
1657 /* If we've already wrapped this or the type is error_mark_node, we can't do
1659 if (TREE_CODE (expr) == WITH_SIZE_EXPR
1660 || type == error_mark_node)
1663 /* If the size isn't known or is a constant, we have nothing to do. */
1664 size = TYPE_SIZE_UNIT (type);
1665 if (!size || TREE_CODE (size) == INTEGER_CST)
1668 /* Otherwise, make a WITH_SIZE_EXPR. */
1669 size = unshare_expr (size);
1670 size = SUBSTITUTE_PLACEHOLDER_IN_EXPR (size, expr);
1671 *expr_p = build2 (WITH_SIZE_EXPR, type, expr, size);
1674 /* Subroutine of gimplify_call_expr: Gimplify a single argument. */
1676 static enum gimplify_status
1677 gimplify_arg (tree *expr_p, tree *pre_p)
1679 bool (*test) (tree);
1682 /* In general, we allow lvalues for function arguments to avoid
1683 extra overhead of copying large aggregates out of even larger
1684 aggregates into temporaries only to copy the temporaries to
1685 the argument list. Make optimizers happy by pulling out to
1686 temporaries those types that fit in registers. */
1687 if (is_gimple_reg_type (TREE_TYPE (*expr_p)))
1688 test = is_gimple_val, fb = fb_rvalue;
1690 test = is_gimple_lvalue, fb = fb_either;
1692 /* If this is a variable sized type, we must remember the size. */
1693 maybe_with_size_expr (expr_p);
1695 /* There is a sequence point before a function call. Side effects in
1696 the argument list must occur before the actual call. So, when
1697 gimplifying arguments, force gimplify_expr to use an internal
1698 post queue which is then appended to the end of PRE_P. */
1699 return gimplify_expr (expr_p, pre_p, NULL, test, fb);
1702 /* Gimplify the CALL_EXPR node pointed by EXPR_P. PRE_P points to the
1703 list where side effects that must happen before *EXPR_P should be stored.
1704 WANT_VALUE is true if the result of the call is desired. */
1706 static enum gimplify_status
1707 gimplify_call_expr (tree *expr_p, tree *pre_p, bool want_value)
1711 enum gimplify_status ret;
1713 gcc_assert (TREE_CODE (*expr_p) == CALL_EXPR);
1715 /* For reliable diagnostics during inlining, it is necessary that
1716 every call_expr be annotated with file and line. */
1717 if (! EXPR_HAS_LOCATION (*expr_p))
1718 SET_EXPR_LOCATION (*expr_p, input_location);
1720 /* This may be a call to a builtin function.
1722 Builtin function calls may be transformed into different
1723 (and more efficient) builtin function calls under certain
1724 circumstances. Unfortunately, gimplification can muck things
1725 up enough that the builtin expanders are not aware that certain
1726 transformations are still valid.
1728 So we attempt transformation/gimplification of the call before
1729 we gimplify the CALL_EXPR. At this time we do not manage to
1730 transform all calls in the same manner as the expanders do, but
1731 we do transform most of them. */
1732 decl = get_callee_fndecl (*expr_p);
1733 if (decl && DECL_BUILT_IN (decl))
1735 tree new = fold_builtin (*expr_p, !want_value);
1737 if (new && new != *expr_p)
1739 /* There was a transformation of this call which computes the
1740 same value, but in a more efficient way. Return and try
1746 if (DECL_FUNCTION_CODE (decl) == BUILT_IN_VA_START)
1747 /* Avoid gimplifying the second argument to va_start, which needs
1748 to be the plain PARM_DECL. */
1749 return gimplify_arg (&TREE_VALUE (TREE_OPERAND (*expr_p, 1)), pre_p);
1752 /* There is a sequence point before the call, so any side effects in
1753 the calling expression must occur before the actual call. Force
1754 gimplify_expr to use an internal post queue. */
1755 ret = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p, NULL,
1756 is_gimple_call_addr, fb_rvalue);
1758 if (PUSH_ARGS_REVERSED)
1759 TREE_OPERAND (*expr_p, 1) = nreverse (TREE_OPERAND (*expr_p, 1));
1760 for (arglist = TREE_OPERAND (*expr_p, 1); arglist;
1761 arglist = TREE_CHAIN (arglist))
1763 enum gimplify_status t;
1765 t = gimplify_arg (&TREE_VALUE (arglist), pre_p);
1770 if (PUSH_ARGS_REVERSED)
1771 TREE_OPERAND (*expr_p, 1) = nreverse (TREE_OPERAND (*expr_p, 1));
1773 /* Try this again in case gimplification exposed something. */
1774 if (ret != GS_ERROR && decl && DECL_BUILT_IN (decl))
1776 tree new = fold_builtin (*expr_p, !want_value);
1778 if (new && new != *expr_p)
1780 /* There was a transformation of this call which computes the
1781 same value, but in a more efficient way. Return and try
1788 /* If the function is "const" or "pure", then clear TREE_SIDE_EFFECTS on its
1789 decl. This allows us to eliminate redundant or useless
1790 calls to "const" functions. */
1791 if (TREE_CODE (*expr_p) == CALL_EXPR
1792 && (call_expr_flags (*expr_p) & (ECF_CONST | ECF_PURE)))
1793 TREE_SIDE_EFFECTS (*expr_p) = 0;
1798 /* Handle shortcut semantics in the predicate operand of a COND_EXPR by
1799 rewriting it into multiple COND_EXPRs, and possibly GOTO_EXPRs.
1801 TRUE_LABEL_P and FALSE_LABEL_P point to the labels to jump to if the
1802 condition is true or false, respectively. If null, we should generate
1803 our own to skip over the evaluation of this specific expression.
1805 This function is the tree equivalent of do_jump.
1807 shortcut_cond_r should only be called by shortcut_cond_expr. */
1810 shortcut_cond_r (tree pred, tree *true_label_p, tree *false_label_p)
1812 tree local_label = NULL_TREE;
1813 tree t, expr = NULL;
1815 /* OK, it's not a simple case; we need to pull apart the COND_EXPR to
1816 retain the shortcut semantics. Just insert the gotos here;
1817 shortcut_cond_expr will append the real blocks later. */
1818 if (TREE_CODE (pred) == TRUTH_ANDIF_EXPR)
1820 /* Turn if (a && b) into
1822 if (a); else goto no;
1823 if (b) goto yes; else goto no;
1826 if (false_label_p == NULL)
1827 false_label_p = &local_label;
1829 t = shortcut_cond_r (TREE_OPERAND (pred, 0), NULL, false_label_p);
1830 append_to_statement_list (t, &expr);
1832 t = shortcut_cond_r (TREE_OPERAND (pred, 1), true_label_p,
1834 append_to_statement_list (t, &expr);
1836 else if (TREE_CODE (pred) == TRUTH_ORIF_EXPR)
1838 /* Turn if (a || b) into
1841 if (b) goto yes; else goto no;
1844 if (true_label_p == NULL)
1845 true_label_p = &local_label;
1847 t = shortcut_cond_r (TREE_OPERAND (pred, 0), true_label_p, NULL);
1848 append_to_statement_list (t, &expr);
1850 t = shortcut_cond_r (TREE_OPERAND (pred, 1), true_label_p,
1852 append_to_statement_list (t, &expr);
1854 else if (TREE_CODE (pred) == COND_EXPR)
1856 /* As long as we're messing with gotos, turn if (a ? b : c) into
1858 if (b) goto yes; else goto no;
1860 if (c) goto yes; else goto no; */
1861 expr = build (COND_EXPR, void_type_node, TREE_OPERAND (pred, 0),
1862 shortcut_cond_r (TREE_OPERAND (pred, 1), true_label_p,
1864 shortcut_cond_r (TREE_OPERAND (pred, 2), true_label_p,
1869 expr = build (COND_EXPR, void_type_node, pred,
1870 build_and_jump (true_label_p),
1871 build_and_jump (false_label_p));
1876 t = build1 (LABEL_EXPR, void_type_node, local_label);
1877 append_to_statement_list (t, &expr);
1884 shortcut_cond_expr (tree expr)
1886 tree pred = TREE_OPERAND (expr, 0);
1887 tree then_ = TREE_OPERAND (expr, 1);
1888 tree else_ = TREE_OPERAND (expr, 2);
1889 tree true_label, false_label, end_label, t;
1891 tree *false_label_p;
1892 bool emit_end, emit_false;
1893 bool then_se = then_ && TREE_SIDE_EFFECTS (then_);
1894 bool else_se = else_ && TREE_SIDE_EFFECTS (else_);
1896 /* First do simple transformations. */
1899 /* If there is no 'else', turn (a && b) into if (a) if (b). */
1900 while (TREE_CODE (pred) == TRUTH_ANDIF_EXPR)
1902 TREE_OPERAND (expr, 0) = TREE_OPERAND (pred, 1);
1903 then_ = shortcut_cond_expr (expr);
1904 pred = TREE_OPERAND (pred, 0);
1905 expr = build (COND_EXPR, void_type_node, pred, then_, NULL_TREE);
1910 /* If there is no 'then', turn
1913 if (a); else if (b); else d. */
1914 while (TREE_CODE (pred) == TRUTH_ORIF_EXPR)
1916 TREE_OPERAND (expr, 0) = TREE_OPERAND (pred, 1);
1917 else_ = shortcut_cond_expr (expr);
1918 pred = TREE_OPERAND (pred, 0);
1919 expr = build (COND_EXPR, void_type_node, pred, NULL_TREE, else_);
1923 /* If we're done, great. */
1924 if (TREE_CODE (pred) != TRUTH_ANDIF_EXPR
1925 && TREE_CODE (pred) != TRUTH_ORIF_EXPR)
1928 /* Otherwise we need to mess with gotos. Change
1931 if (a); else goto no;
1934 and recursively gimplify the condition. */
1936 true_label = false_label = end_label = NULL_TREE;
1938 /* If our arms just jump somewhere, hijack those labels so we don't
1939 generate jumps to jumps. */
1942 && TREE_CODE (then_) == GOTO_EXPR
1943 && TREE_CODE (GOTO_DESTINATION (then_)) == LABEL_DECL)
1945 true_label = GOTO_DESTINATION (then_);
1951 && TREE_CODE (else_) == GOTO_EXPR
1952 && TREE_CODE (GOTO_DESTINATION (else_)) == LABEL_DECL)
1954 false_label = GOTO_DESTINATION (else_);
1959 /* If we aren't hijacking a label for the 'then' branch, it falls through. */
1961 true_label_p = &true_label;
1963 true_label_p = NULL;
1965 /* The 'else' branch also needs a label if it contains interesting code. */
1966 if (false_label || else_se)
1967 false_label_p = &false_label;
1969 false_label_p = NULL;
1971 /* If there was nothing else in our arms, just forward the label(s). */
1972 if (!then_se && !else_se)
1973 return shortcut_cond_r (pred, true_label_p, false_label_p);
1975 /* If our last subexpression already has a terminal label, reuse it. */
1977 expr = expr_last (else_);
1979 expr = expr_last (then_);
1982 if (expr && TREE_CODE (expr) == LABEL_EXPR)
1983 end_label = LABEL_EXPR_LABEL (expr);
1985 /* If we don't care about jumping to the 'else' branch, jump to the end
1986 if the condition is false. */
1988 false_label_p = &end_label;
1990 /* We only want to emit these labels if we aren't hijacking them. */
1991 emit_end = (end_label == NULL_TREE);
1992 emit_false = (false_label == NULL_TREE);
1994 pred = shortcut_cond_r (pred, true_label_p, false_label_p);
1997 append_to_statement_list (pred, &expr);
1999 append_to_statement_list (then_, &expr);
2002 t = build_and_jump (&end_label);
2003 append_to_statement_list (t, &expr);
2006 t = build1 (LABEL_EXPR, void_type_node, false_label);
2007 append_to_statement_list (t, &expr);
2009 append_to_statement_list (else_, &expr);
2011 if (emit_end && end_label)
2013 t = build1 (LABEL_EXPR, void_type_node, end_label);
2014 append_to_statement_list (t, &expr);
2020 /* EXPR is used in a boolean context; make sure it has BOOLEAN_TYPE. */
2023 gimple_boolify (tree expr)
2025 tree type = TREE_TYPE (expr);
2027 if (TREE_CODE (type) == BOOLEAN_TYPE)
2030 /* If this is the predicate of a COND_EXPR, it might not even be a
2032 expr = lang_hooks.truthvalue_conversion (expr);
2034 switch (TREE_CODE (expr))
2036 case TRUTH_AND_EXPR:
2038 case TRUTH_XOR_EXPR:
2039 case TRUTH_ANDIF_EXPR:
2040 case TRUTH_ORIF_EXPR:
2041 /* Also boolify the arguments of truth exprs. */
2042 TREE_OPERAND (expr, 1) = gimple_boolify (TREE_OPERAND (expr, 1));
2045 case TRUTH_NOT_EXPR:
2046 TREE_OPERAND (expr, 0) = gimple_boolify (TREE_OPERAND (expr, 0));
2049 case EQ_EXPR: case NE_EXPR:
2050 case LE_EXPR: case GE_EXPR: case LT_EXPR: case GT_EXPR:
2051 /* These expressions always produce boolean results. */
2052 TREE_TYPE (expr) = boolean_type_node;
2056 /* Other expressions that get here must have boolean values, but
2057 might need to be converted to the appropriate mode. */
2058 return convert (boolean_type_node, expr);
2062 /* Convert the conditional expression pointed by EXPR_P '(p) ? a : b;'
2071 The second form is used when *EXPR_P is of type void.
2073 TARGET is the tree for T1 above.
2075 PRE_P points to the list where side effects that must happen before
2076 *EXPR_P should be stored. */
2078 static enum gimplify_status
2079 gimplify_cond_expr (tree *expr_p, tree *pre_p, tree target)
2081 tree expr = *expr_p;
2082 tree tmp, tmp2, type;
2083 enum gimplify_status ret;
2085 type = TREE_TYPE (expr);
2087 TREE_TYPE (expr) = void_type_node;
2089 /* If this COND_EXPR has a value, copy the values into a temporary within
2091 else if (! VOID_TYPE_P (type))
2095 ret = gimplify_expr (&target, pre_p, NULL,
2096 is_gimple_min_lval, fb_lvalue);
2097 if (ret != GS_ERROR)
2100 tmp2 = unshare_expr (target);
2104 tmp2 = tmp = create_tmp_var (TREE_TYPE (expr), "iftmp");
2108 /* Build the then clause, 't1 = a;'. But don't build an assignment
2109 if this branch is void; in C++ it can be, if it's a throw. */
2110 if (TREE_TYPE (TREE_OPERAND (expr, 1)) != void_type_node)
2111 TREE_OPERAND (expr, 1)
2112 = build (MODIFY_EXPR, void_type_node, tmp, TREE_OPERAND (expr, 1));
2114 /* Build the else clause, 't1 = b;'. */
2115 if (TREE_TYPE (TREE_OPERAND (expr, 2)) != void_type_node)
2116 TREE_OPERAND (expr, 2)
2117 = build (MODIFY_EXPR, void_type_node, tmp2, TREE_OPERAND (expr, 2));
2119 TREE_TYPE (expr) = void_type_node;
2120 recalculate_side_effects (expr);
2122 /* Move the COND_EXPR to the prequeue. */
2123 gimplify_and_add (expr, pre_p);
2129 /* Make sure the condition has BOOLEAN_TYPE. */
2130 TREE_OPERAND (expr, 0) = gimple_boolify (TREE_OPERAND (expr, 0));
2132 /* Break apart && and || conditions. */
2133 if (TREE_CODE (TREE_OPERAND (expr, 0)) == TRUTH_ANDIF_EXPR
2134 || TREE_CODE (TREE_OPERAND (expr, 0)) == TRUTH_ORIF_EXPR)
2136 expr = shortcut_cond_expr (expr);
2138 if (expr != *expr_p)
2142 /* We can't rely on gimplify_expr to re-gimplify the expanded
2143 form properly, as cleanups might cause the target labels to be
2144 wrapped in a TRY_FINALLY_EXPR. To prevent that, we need to
2145 set up a conditional context. */
2146 gimple_push_condition ();
2147 gimplify_stmt (expr_p);
2148 gimple_pop_condition (pre_p);
2154 /* Now do the normal gimplification. */
2155 ret = gimplify_expr (&TREE_OPERAND (expr, 0), pre_p, NULL,
2156 is_gimple_condexpr, fb_rvalue);
2158 gimple_push_condition ();
2160 gimplify_to_stmt_list (&TREE_OPERAND (expr, 1));
2161 gimplify_to_stmt_list (&TREE_OPERAND (expr, 2));
2162 recalculate_side_effects (expr);
2164 gimple_pop_condition (pre_p);
2166 if (ret == GS_ERROR)
2168 else if (TREE_SIDE_EFFECTS (TREE_OPERAND (expr, 1)))
2170 else if (TREE_SIDE_EFFECTS (TREE_OPERAND (expr, 2)))
2171 /* Rewrite "if (a); else b" to "if (!a) b" */
2173 TREE_OPERAND (expr, 0) = invert_truthvalue (TREE_OPERAND (expr, 0));
2174 ret = gimplify_expr (&TREE_OPERAND (expr, 0), pre_p, NULL,
2175 is_gimple_condexpr, fb_rvalue);
2177 tmp = TREE_OPERAND (expr, 1);
2178 TREE_OPERAND (expr, 1) = TREE_OPERAND (expr, 2);
2179 TREE_OPERAND (expr, 2) = tmp;
2182 /* Both arms are empty; replace the COND_EXPR with its predicate. */
2183 expr = TREE_OPERAND (expr, 0);
2189 /* A subroutine of gimplify_modify_expr. Replace a MODIFY_EXPR with
2190 a call to __builtin_memcpy. */
2192 static enum gimplify_status
2193 gimplify_modify_expr_to_memcpy (tree *expr_p, tree size, bool want_value)
2195 tree args, t, to, to_ptr, from;
2197 to = TREE_OPERAND (*expr_p, 0);
2198 from = TREE_OPERAND (*expr_p, 1);
2200 args = tree_cons (NULL, size, NULL);
2202 t = build_fold_addr_expr (from);
2203 args = tree_cons (NULL, t, args);
2205 to_ptr = build_fold_addr_expr (to);
2206 args = tree_cons (NULL, to_ptr, args);
2207 t = implicit_built_in_decls[BUILT_IN_MEMCPY];
2208 t = build_function_call_expr (t, args);
2212 t = build1 (NOP_EXPR, TREE_TYPE (to_ptr), t);
2213 t = build1 (INDIRECT_REF, TREE_TYPE (to), t);
2220 /* A subroutine of gimplify_modify_expr. Replace a MODIFY_EXPR with
2221 a call to __builtin_memset. In this case we know that the RHS is
2222 a CONSTRUCTOR with an empty element list. */
2224 static enum gimplify_status
2225 gimplify_modify_expr_to_memset (tree *expr_p, tree size, bool want_value)
2227 tree args, t, to, to_ptr;
2229 to = TREE_OPERAND (*expr_p, 0);
2231 args = tree_cons (NULL, size, NULL);
2233 args = tree_cons (NULL, integer_zero_node, args);
2235 to_ptr = build_fold_addr_expr (to);
2236 args = tree_cons (NULL, to_ptr, args);
2237 t = implicit_built_in_decls[BUILT_IN_MEMSET];
2238 t = build_function_call_expr (t, args);
2242 t = build1 (NOP_EXPR, TREE_TYPE (to_ptr), t);
2243 t = build1 (INDIRECT_REF, TREE_TYPE (to), t);
2250 /* A subroutine of gimplify_init_ctor_preeval. Called via walk_tree,
2251 determine, cautiously, if a CONSTRUCTOR overlaps the lhs of an
2252 assignment. Returns non-null if we detect a potential overlap. */
2254 struct gimplify_init_ctor_preeval_data
2256 /* The base decl of the lhs object. May be NULL, in which case we
2257 have to assume the lhs is indirect. */
2260 /* The alias set of the lhs object. */
2265 gimplify_init_ctor_preeval_1 (tree *tp, int *walk_subtrees, void *xdata)
2267 struct gimplify_init_ctor_preeval_data *data
2268 = (struct gimplify_init_ctor_preeval_data *) xdata;
2271 /* If we find the base object, obviously we have overlap. */
2272 if (data->lhs_base_decl == t)
2275 /* If the constructor component is indirect, determine if we have a
2276 potential overlap with the lhs. The only bits of information we
2277 have to go on at this point are addressability and alias sets. */
2278 if (TREE_CODE (t) == INDIRECT_REF
2279 && (!data->lhs_base_decl || TREE_ADDRESSABLE (data->lhs_base_decl))
2280 && alias_sets_conflict_p (data->lhs_alias_set, get_alias_set (t)))
2283 if (IS_TYPE_OR_DECL_P (t))
2288 /* A subroutine of gimplify_init_constructor. Pre-evaluate *EXPR_P,
2289 force values that overlap with the lhs (as described by *DATA)
2290 into temporaries. */
2293 gimplify_init_ctor_preeval (tree *expr_p, tree *pre_p, tree *post_p,
2294 struct gimplify_init_ctor_preeval_data *data)
2296 enum gimplify_status one;
2298 /* If the value is invariant, then there's nothing to pre-evaluate.
2299 But ensure it doesn't have any side-effects since a SAVE_EXPR is
2300 invariant but has side effects and might contain a reference to
2301 the object we're initializing. */
2302 if (TREE_INVARIANT (*expr_p) && !TREE_SIDE_EFFECTS (*expr_p))
2305 /* If the type has non-trivial constructors, we can't pre-evaluate. */
2306 if (TREE_ADDRESSABLE (TREE_TYPE (*expr_p)))
2309 /* Recurse for nested constructors. */
2310 if (TREE_CODE (*expr_p) == CONSTRUCTOR)
2313 for (list = CONSTRUCTOR_ELTS (*expr_p); list ; list = TREE_CHAIN (list))
2314 gimplify_init_ctor_preeval (&TREE_VALUE (list), pre_p, post_p, data);
2318 /* We can't preevaluate if the type contains a placeholder. */
2319 if (type_contains_placeholder_p (TREE_TYPE (*expr_p)))
2322 /* Gimplify the constructor element to something appropriate for the rhs
2323 of a MODIFY_EXPR. Given that we know the lhs is an aggregate, we know
2324 the gimplifier will consider this a store to memory. Doing this
2325 gimplification now means that we won't have to deal with complicated
2326 language-specific trees, nor trees like SAVE_EXPR that can induce
2327 exponential search behavior. */
2328 one = gimplify_expr (expr_p, pre_p, post_p, is_gimple_mem_rhs, fb_rvalue);
2329 if (one == GS_ERROR)
2335 /* If we gimplified to a bare decl, we can be sure that it doesn't overlap
2336 with the lhs, since "a = { .x=a }" doesn't make sense. This will
2337 always be true for all scalars, since is_gimple_mem_rhs insists on a
2338 temporary variable for them. */
2339 if (DECL_P (*expr_p))
2342 /* If this is of variable size, we have no choice but to assume it doesn't
2343 overlap since we can't make a temporary for it. */
2344 if (!TREE_CONSTANT (TYPE_SIZE (TREE_TYPE (*expr_p))))
2347 /* Otherwise, we must search for overlap ... */
2348 if (!walk_tree (expr_p, gimplify_init_ctor_preeval_1, data, NULL))
2351 /* ... and if found, force the value into a temporary. */
2352 *expr_p = get_formal_tmp_var (*expr_p, pre_p);
2355 /* A subroutine of gimplify_init_constructor. Generate individual
2356 MODIFY_EXPRs for a CONSTRUCTOR. OBJECT is the LHS against which the
2357 assignments should happen. LIST is the CONSTRUCTOR_ELTS of the
2358 CONSTRUCTOR. CLEARED is true if the entire LHS object has been
2362 gimplify_init_ctor_eval (tree object, tree list, tree *pre_p, bool cleared)
2364 tree array_elt_type = NULL;
2366 if (TREE_CODE (TREE_TYPE (object)) == ARRAY_TYPE)
2367 array_elt_type = TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (object)));
2369 for (; list; list = TREE_CHAIN (list))
2371 tree purpose, value, cref, init;
2373 purpose = TREE_PURPOSE (list);
2374 value = TREE_VALUE (list);
2376 /* NULL values are created above for gimplification errors. */
2380 if (cleared && initializer_zerop (value))
2385 /* ??? Here's to hoping the front end fills in all of the indicies,
2386 so we don't have to figure out what's missing ourselves. */
2387 gcc_assert (purpose);
2388 /* ??? Need to handle this. */
2389 gcc_assert (TREE_CODE (purpose) != RANGE_EXPR);
2391 cref = build (ARRAY_REF, array_elt_type, unshare_expr (object),
2392 purpose, NULL_TREE, NULL_TREE);
2395 cref = build (COMPONENT_REF, TREE_TYPE (purpose),
2396 unshare_expr (object), purpose, NULL_TREE);
2398 if (TREE_CODE (value) == CONSTRUCTOR)
2399 gimplify_init_ctor_eval (cref, CONSTRUCTOR_ELTS (value),
2403 init = build (MODIFY_EXPR, TREE_TYPE (cref), cref, value);
2404 gimplify_and_add (init, pre_p);
2409 /* A subroutine of gimplify_modify_expr. Break out elements of a
2410 CONSTRUCTOR used as an initializer into separate MODIFY_EXPRs.
2412 Note that we still need to clear any elements that don't have explicit
2413 initializers, so if not all elements are initialized we keep the
2414 original MODIFY_EXPR, we just remove all of the constructor elements. */
2416 static enum gimplify_status
2417 gimplify_init_constructor (tree *expr_p, tree *pre_p,
2418 tree *post_p, bool want_value)
2421 tree ctor = TREE_OPERAND (*expr_p, 1);
2422 tree type = TREE_TYPE (ctor);
2423 enum gimplify_status ret;
2426 if (TREE_CODE (ctor) != CONSTRUCTOR)
2427 return GS_UNHANDLED;
2429 ret = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p, post_p,
2430 is_gimple_lvalue, fb_lvalue);
2431 if (ret == GS_ERROR)
2433 object = TREE_OPERAND (*expr_p, 0);
2435 elt_list = CONSTRUCTOR_ELTS (ctor);
2438 switch (TREE_CODE (type))
2442 case QUAL_UNION_TYPE:
2445 struct gimplify_init_ctor_preeval_data preeval_data;
2446 HOST_WIDE_INT num_elements, num_nonzero_elements;
2447 HOST_WIDE_INT num_nonconstant_elements;
2450 /* Aggregate types must lower constructors to initialization of
2451 individual elements. The exception is that a CONSTRUCTOR node
2452 with no elements indicates zero-initialization of the whole. */
2453 if (elt_list == NULL)
2456 categorize_ctor_elements (ctor, &num_nonzero_elements,
2457 &num_nonconstant_elements);
2459 /* If a const aggregate variable is being initialized, then it
2460 should never be a lose to promote the variable to be static. */
2461 if (num_nonconstant_elements == 0
2462 && TREE_READONLY (object)
2463 && TREE_CODE (object) == VAR_DECL)
2465 DECL_INITIAL (object) = ctor;
2466 TREE_STATIC (object) = 1;
2467 if (!DECL_NAME (object))
2468 DECL_NAME (object) = create_tmp_var_name ("C");
2469 walk_tree (&DECL_INITIAL (object), force_labels_r, NULL, NULL);
2471 /* ??? C++ doesn't automatically append a .<number> to the
2472 assembler name, and even when it does, it looks a FE private
2473 data structures to figure out what that number should be,
2474 which are not set for this variable. I suppose this is
2475 important for local statics for inline functions, which aren't
2476 "local" in the object file sense. So in order to get a unique
2477 TU-local symbol, we must invoke the lhd version now. */
2478 lhd_set_decl_assembler_name (object);
2480 *expr_p = NULL_TREE;
2484 /* If there are "lots" of initialized elements, and all of them
2485 are valid address constants, then the entire initializer can
2486 be dropped to memory, and then memcpy'd out. */
2487 if (num_nonconstant_elements == 0)
2489 HOST_WIDE_INT size = int_size_in_bytes (type);
2492 /* ??? We can still get unbounded array types, at least
2493 from the C++ front end. This seems wrong, but attempt
2494 to work around it for now. */
2497 size = int_size_in_bytes (TREE_TYPE (object));
2499 TREE_TYPE (ctor) = type = TREE_TYPE (object);
2502 /* Find the maximum alignment we can assume for the object. */
2503 /* ??? Make use of DECL_OFFSET_ALIGN. */
2504 if (DECL_P (object))
2505 align = DECL_ALIGN (object);
2507 align = TYPE_ALIGN (type);
2509 if (size > 0 && !can_move_by_pieces (size, align))
2511 tree new = create_tmp_var_raw (type, "C");
2513 gimple_add_tmp_var (new);
2514 TREE_STATIC (new) = 1;
2515 TREE_READONLY (new) = 1;
2516 DECL_INITIAL (new) = ctor;
2517 if (align > DECL_ALIGN (new))
2519 DECL_ALIGN (new) = align;
2520 DECL_USER_ALIGN (new) = 1;
2522 walk_tree (&DECL_INITIAL (new), force_labels_r, NULL, NULL);
2524 TREE_OPERAND (*expr_p, 1) = new;
2526 /* This is no longer an assignment of a CONSTRUCTOR, but
2527 we still may have processing to do on the LHS. So
2528 pretend we didn't do anything here to let that happen. */
2529 return GS_UNHANDLED;
2533 /* If there are "lots" of initialized elements, even discounting
2534 those that are not address constants (and thus *must* be
2535 computed at runtime), then partition the constructor into
2536 constant and non-constant parts. Block copy the constant
2537 parts in, then generate code for the non-constant parts. */
2538 /* TODO. There's code in cp/typeck.c to do this. */
2540 num_elements = count_type_elements (TREE_TYPE (ctor));
2542 /* If there are "lots" of zeros, then block clear the object first. */
2544 if (num_elements - num_nonzero_elements > CLEAR_RATIO
2545 && num_nonzero_elements < num_elements/4)
2548 /* ??? This bit ought not be needed. For any element not present
2549 in the initializer, we should simply set them to zero. Except
2550 we'd need to *find* the elements that are not present, and that
2551 requires trickery to avoid quadratic compile-time behavior in
2552 large cases or excessive memory use in small cases. */
2555 HOST_WIDE_INT len = list_length (elt_list);
2556 if (TREE_CODE (type) == ARRAY_TYPE)
2558 tree nelts = array_type_nelts (type);
2559 if (!host_integerp (nelts, 1)
2560 || tree_low_cst (nelts, 1) + 1 != len)
2563 else if (len != fields_length (type))
2569 /* Zap the CONSTRUCTOR element list, which simplifies this case.
2570 Note that we still have to gimplify, in order to handle the
2571 case of variable sized types. Avoid shared tree structures. */
2572 CONSTRUCTOR_ELTS (ctor) = NULL_TREE;
2573 object = unshare_expr (object);
2574 gimplify_stmt (expr_p);
2575 append_to_statement_list (*expr_p, pre_p);
2578 preeval_data.lhs_base_decl = get_base_address (object);
2579 if (!DECL_P (preeval_data.lhs_base_decl))
2580 preeval_data.lhs_base_decl = NULL;
2581 preeval_data.lhs_alias_set = get_alias_set (object);
2583 gimplify_init_ctor_preeval (&TREE_OPERAND (*expr_p, 1),
2584 pre_p, post_p, &preeval_data);
2585 gimplify_init_ctor_eval (object, elt_list, pre_p, cleared);
2587 *expr_p = NULL_TREE;
2595 /* Extract the real and imaginary parts out of the ctor. */
2599 r = TREE_VALUE (elt_list);
2600 elt_list = TREE_CHAIN (elt_list);
2603 i = TREE_VALUE (elt_list);
2604 gcc_assert (!TREE_CHAIN (elt_list));
2607 if (r == NULL || i == NULL)
2609 tree zero = convert (TREE_TYPE (type), integer_zero_node);
2616 /* Complex types have either COMPLEX_CST or COMPLEX_EXPR to
2617 represent creation of a complex value. */
2618 if (TREE_CONSTANT (r) && TREE_CONSTANT (i))
2620 ctor = build_complex (type, r, i);
2621 TREE_OPERAND (*expr_p, 1) = ctor;
2625 ctor = build (COMPLEX_EXPR, type, r, i);
2626 TREE_OPERAND (*expr_p, 1) = ctor;
2627 ret = gimplify_expr (&TREE_OPERAND (*expr_p, 1), pre_p, post_p,
2628 rhs_predicate_for (TREE_OPERAND (*expr_p, 0)),
2635 /* Go ahead and simplify constant constructors to VECTOR_CST. */
2636 if (TREE_CONSTANT (ctor))
2637 TREE_OPERAND (*expr_p, 1) = build_vector (type, elt_list);
2640 /* Vector types use CONSTRUCTOR all the way through gimple
2641 compilation as a general initializer. */
2642 for (; elt_list; elt_list = TREE_CHAIN (elt_list))
2644 enum gimplify_status tret;
2645 tret = gimplify_expr (&TREE_VALUE (elt_list), pre_p, post_p,
2646 is_gimple_val, fb_rvalue);
2647 if (tret == GS_ERROR)
2654 /* So how did we get a CONSTRUCTOR for a scalar type? */
2658 if (ret == GS_ERROR)
2660 else if (want_value)
2662 append_to_statement_list (*expr_p, pre_p);
2670 /* Subroutine of gimplify_modify_expr to do simplifications of MODIFY_EXPRs
2671 based on the code of the RHS. We loop for as long as something changes. */
2673 static enum gimplify_status
2674 gimplify_modify_expr_rhs (tree *expr_p, tree *from_p, tree *to_p, tree *pre_p,
2675 tree *post_p, bool want_value)
2677 enum gimplify_status ret = GS_OK;
2679 while (ret != GS_UNHANDLED)
2680 switch (TREE_CODE (*from_p))
2684 /* If we are initializing something from a TARGET_EXPR, strip the
2685 TARGET_EXPR and initialize it directly, if possible. This can't
2686 be done if the initializer is void, since that implies that the
2687 temporary is set in some non-trivial way.
2689 ??? What about code that pulls out the temp and uses it
2690 elsewhere? I think that such code never uses the TARGET_EXPR as
2691 an initializer. If I'm wrong, we'll abort because the temp won't
2692 have any RTL. In that case, I guess we'll need to replace
2693 references somehow. */
2694 tree init = TARGET_EXPR_INITIAL (*from_p);
2696 if (!VOID_TYPE_P (TREE_TYPE (init)))
2707 /* Remove any COMPOUND_EXPR in the RHS so the following cases will be
2709 gimplify_compound_expr (from_p, pre_p, true);
2714 /* If we're initializing from a CONSTRUCTOR, break this into
2715 individual MODIFY_EXPRs. */
2716 return gimplify_init_constructor (expr_p, pre_p, post_p, want_value);
2719 /* If we're assigning to a non-register type, push the assignment
2720 down into the branches. This is mandatory for ADDRESSABLE types,
2721 since we cannot generate temporaries for such, but it saves a
2722 copy in other cases as well. */
2723 if (!is_gimple_reg_type (TREE_TYPE (*from_p)))
2726 return gimplify_cond_expr (expr_p, pre_p, *to_p);
2740 /* Gimplify the MODIFY_EXPR node pointed by EXPR_P.
2746 PRE_P points to the list where side effects that must happen before
2747 *EXPR_P should be stored.
2749 POST_P points to the list where side effects that must happen after
2750 *EXPR_P should be stored.
2752 WANT_VALUE is nonzero iff we want to use the value of this expression
2753 in another expression. */
2755 static enum gimplify_status
2756 gimplify_modify_expr (tree *expr_p, tree *pre_p, tree *post_p, bool want_value)
2758 tree *from_p = &TREE_OPERAND (*expr_p, 1);
2759 tree *to_p = &TREE_OPERAND (*expr_p, 0);
2760 enum gimplify_status ret = GS_UNHANDLED;
2762 gcc_assert (TREE_CODE (*expr_p) == MODIFY_EXPR
2763 || TREE_CODE (*expr_p) == INIT_EXPR);
2765 /* The distinction between MODIFY_EXPR and INIT_EXPR is no longer useful. */
2766 if (TREE_CODE (*expr_p) == INIT_EXPR)
2767 TREE_SET_CODE (*expr_p, MODIFY_EXPR);
2769 /* See if any simplifications can be done based on what the RHS is. */
2770 ret = gimplify_modify_expr_rhs (expr_p, from_p, to_p, pre_p, post_p,
2772 if (ret != GS_UNHANDLED)
2775 /* If the value being copied is of variable width, compute the length
2776 of the copy into a WITH_SIZE_EXPR. Note that we need to do this
2777 before gimplifying any of the operands so that we can resolve any
2778 PLACEHOLDER_EXPRs in the size. Also note that the RTL expander uses
2779 the size of the expression to be copied, not of the destination, so
2780 that is what we must here. */
2781 maybe_with_size_expr (from_p);
2783 ret = gimplify_expr (to_p, pre_p, post_p, is_gimple_lvalue, fb_lvalue);
2784 if (ret == GS_ERROR)
2787 ret = gimplify_expr (from_p, pre_p, post_p,
2788 rhs_predicate_for (*to_p), fb_rvalue);
2789 if (ret == GS_ERROR)
2792 /* Now see if the above changed *from_p to something we handle specially. */
2793 ret = gimplify_modify_expr_rhs (expr_p, from_p, to_p, pre_p, post_p,
2795 if (ret != GS_UNHANDLED)
2798 /* If we've got a variable sized assignment between two lvalues (i.e. does
2799 not involve a call), then we can make things a bit more straightforward
2800 by converting the assignment to memcpy or memset. */
2801 if (TREE_CODE (*from_p) == WITH_SIZE_EXPR)
2803 tree from = TREE_OPERAND (*from_p, 0);
2804 tree size = TREE_OPERAND (*from_p, 1);
2806 if (TREE_CODE (from) == CONSTRUCTOR)
2807 return gimplify_modify_expr_to_memset (expr_p, size, want_value);
2808 if (is_gimple_addressable (from))
2811 return gimplify_modify_expr_to_memcpy (expr_p, size, want_value);
2815 if (gimplify_ctxp->into_ssa && is_gimple_reg (*to_p))
2817 /* If we've somehow already got an SSA_NAME on the LHS, then
2818 we're probably modifying it twice. Not good. */
2819 gcc_assert (TREE_CODE (*to_p) != SSA_NAME);
2820 *to_p = make_ssa_name (*to_p, *expr_p);
2825 append_to_statement_list (*expr_p, pre_p);
2833 /* Gimplify a comparison between two variable-sized objects. Do this
2834 with a call to BUILT_IN_MEMCMP. */
2836 static enum gimplify_status
2837 gimplify_variable_sized_compare (tree *expr_p)
2839 tree op0 = TREE_OPERAND (*expr_p, 0);
2840 tree op1 = TREE_OPERAND (*expr_p, 1);
2843 t = TYPE_SIZE_UNIT (TREE_TYPE (op0));
2844 t = unshare_expr (t);
2845 t = SUBSTITUTE_PLACEHOLDER_IN_EXPR (t, op0);
2846 args = tree_cons (NULL, t, NULL);
2847 t = build_fold_addr_expr (op1);
2848 args = tree_cons (NULL, t, args);
2849 dest = build_fold_addr_expr (op0);
2850 args = tree_cons (NULL, dest, args);
2851 t = implicit_built_in_decls[BUILT_IN_MEMCMP];
2852 t = build_function_call_expr (t, args);
2854 = build (TREE_CODE (*expr_p), TREE_TYPE (*expr_p), t, integer_zero_node);
2859 /* Gimplify TRUTH_ANDIF_EXPR and TRUTH_ORIF_EXPR expressions. EXPR_P
2860 points to the expression to gimplify.
2862 Expressions of the form 'a && b' are gimplified to:
2864 a && b ? true : false
2866 gimplify_cond_expr will do the rest.
2868 PRE_P points to the list where side effects that must happen before
2869 *EXPR_P should be stored. */
2871 static enum gimplify_status
2872 gimplify_boolean_expr (tree *expr_p)
2874 /* Preserve the original type of the expression. */
2875 tree type = TREE_TYPE (*expr_p);
2877 *expr_p = build (COND_EXPR, type, *expr_p,
2878 convert (type, boolean_true_node),
2879 convert (type, boolean_false_node));
2884 /* Gimplifies an expression sequence. This function gimplifies each
2885 expression and re-writes the original expression with the last
2886 expression of the sequence in GIMPLE form.
2888 PRE_P points to the list where the side effects for all the
2889 expressions in the sequence will be emitted.
2891 WANT_VALUE is true when the result of the last COMPOUND_EXPR is used. */
2892 /* ??? Should rearrange to share the pre-queue with all the indirect
2893 invocations of gimplify_expr. Would probably save on creations
2894 of statement_list nodes. */
2896 static enum gimplify_status
2897 gimplify_compound_expr (tree *expr_p, tree *pre_p, bool want_value)
2903 tree *sub_p = &TREE_OPERAND (t, 0);
2905 if (TREE_CODE (*sub_p) == COMPOUND_EXPR)
2906 gimplify_compound_expr (sub_p, pre_p, false);
2908 gimplify_stmt (sub_p);
2909 append_to_statement_list (*sub_p, pre_p);
2911 t = TREE_OPERAND (t, 1);
2913 while (TREE_CODE (t) == COMPOUND_EXPR);
2920 gimplify_stmt (expr_p);
2925 /* Gimplifies a statement list. These may be created either by an
2926 enlightened front-end, or by shortcut_cond_expr. */
2928 static enum gimplify_status
2929 gimplify_statement_list (tree *expr_p)
2931 tree_stmt_iterator i = tsi_start (*expr_p);
2933 while (!tsi_end_p (i))
2937 gimplify_stmt (tsi_stmt_ptr (i));
2942 else if (TREE_CODE (t) == STATEMENT_LIST)
2944 tsi_link_before (&i, t, TSI_SAME_STMT);
2954 /* Gimplify a SAVE_EXPR node. EXPR_P points to the expression to
2955 gimplify. After gimplification, EXPR_P will point to a new temporary
2956 that holds the original value of the SAVE_EXPR node.
2958 PRE_P points to the list where side effects that must happen before
2959 *EXPR_P should be stored. */
2961 static enum gimplify_status
2962 gimplify_save_expr (tree *expr_p, tree *pre_p, tree *post_p)
2964 enum gimplify_status ret = GS_ALL_DONE;
2967 gcc_assert (TREE_CODE (*expr_p) == SAVE_EXPR);
2968 val = TREE_OPERAND (*expr_p, 0);
2970 /* If the SAVE_EXPR has not been resolved, then evaluate it once. */
2971 if (!SAVE_EXPR_RESOLVED_P (*expr_p))
2973 /* The operand may be a void-valued expression such as SAVE_EXPRs
2974 generated by the Java frontend for class initialization. It is
2975 being executed only for its side-effects. */
2976 if (TREE_TYPE (val) == void_type_node)
2978 ret = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p, post_p,
2979 is_gimple_stmt, fb_none);
2980 append_to_statement_list (TREE_OPERAND (*expr_p, 0), pre_p);
2984 val = get_initialized_tmp_var (val, pre_p, post_p);
2986 TREE_OPERAND (*expr_p, 0) = val;
2987 SAVE_EXPR_RESOLVED_P (*expr_p) = 1;
2995 /* Re-write the ADDR_EXPR node pointed by EXPR_P
3002 PRE_P points to the list where side effects that must happen before
3003 *EXPR_P should be stored.
3005 POST_P points to the list where side effects that must happen after
3006 *EXPR_P should be stored. */
3008 static enum gimplify_status
3009 gimplify_addr_expr (tree *expr_p, tree *pre_p, tree *post_p)
3011 tree expr = *expr_p;
3012 tree op0 = TREE_OPERAND (expr, 0);
3013 enum gimplify_status ret;
3015 switch (TREE_CODE (op0))
3018 case MISALIGNED_INDIRECT_REF:
3020 /* Check if we are dealing with an expression of the form '&*ptr'.
3021 While the front end folds away '&*ptr' into 'ptr', these
3022 expressions may be generated internally by the compiler (e.g.,
3023 builtins like __builtin_va_end). */
3024 /* Caution: the silent array decomposition semantics we allow for
3025 ADDR_EXPR means we can't always discard the pair. */
3027 tree op00 = TREE_OPERAND (op0, 0);
3028 tree t_expr = TREE_TYPE (expr);
3029 tree t_op00 = TREE_TYPE (op00);
3031 if (!lang_hooks.types_compatible_p (t_expr, t_op00))
3033 #ifdef ENABLE_CHECKING
3034 tree t_op0 = TREE_TYPE (op0);
3035 gcc_assert (TREE_CODE (t_op0) == ARRAY_TYPE
3036 && POINTER_TYPE_P (t_expr)
3037 && cpt_same_type (TREE_TYPE (t_op0),
3039 && POINTER_TYPE_P (t_op00)
3040 && cpt_same_type (t_op0, TREE_TYPE (t_op00)));
3042 op00 = fold_convert (TREE_TYPE (expr), op00);
3049 case VIEW_CONVERT_EXPR:
3050 /* Take the address of our operand and then convert it to the type of
3053 ??? The interactions of VIEW_CONVERT_EXPR and aliasing is not at
3054 all clear. The impact of this transformation is even less clear. */
3056 /* If the operand is a useless conversion, look through it. Doing so
3057 guarantees that the ADDR_EXPR and its operand will remain of the
3059 if (tree_ssa_useless_type_conversion (TREE_OPERAND (op0, 0)))
3060 op0 = TREE_OPERAND (op0, 0);
3062 *expr_p = fold_convert (TREE_TYPE (expr),
3063 build_fold_addr_expr (TREE_OPERAND (op0, 0)));
3068 /* We use fb_either here because the C frontend sometimes takes
3069 the address of a call that returns a struct; see
3070 gcc.dg/c99-array-lval-1.c. The gimplifier will correctly make
3071 the implied temporary explicit. */
3072 ret = gimplify_expr (&TREE_OPERAND (expr, 0), pre_p, post_p,
3073 is_gimple_addressable, fb_either);
3074 if (ret != GS_ERROR)
3076 op0 = TREE_OPERAND (expr, 0);
3078 /* For various reasons, the gimplification of the expression
3079 may have made a new INDIRECT_REF. */
3080 if (TREE_CODE (op0) == INDIRECT_REF)
3081 goto do_indirect_ref;
3083 /* Make sure TREE_INVARIANT, TREE_CONSTANT, and TREE_SIDE_EFFECTS
3085 recompute_tree_invarant_for_addr_expr (expr);
3087 /* Mark the RHS addressable. */
3088 lang_hooks.mark_addressable (TREE_OPERAND (expr, 0));
3096 /* Gimplify the operands of an ASM_EXPR. Input operands should be a gimple
3097 value; output operands should be a gimple lvalue. */
3099 static enum gimplify_status
3100 gimplify_asm_expr (tree *expr_p, tree *pre_p, tree *post_p)
3102 tree expr = *expr_p;
3103 int noutputs = list_length (ASM_OUTPUTS (expr));
3104 const char **oconstraints
3105 = (const char **) alloca ((noutputs) * sizeof (const char *));
3108 const char *constraint;
3109 bool allows_mem, allows_reg, is_inout;
3110 enum gimplify_status ret, tret;
3113 = resolve_asm_operand_names (ASM_STRING (expr), ASM_OUTPUTS (expr),
3117 for (i = 0, link = ASM_OUTPUTS (expr); link; ++i, link = TREE_CHAIN (link))
3119 size_t constraint_len;
3120 oconstraints[i] = constraint
3121 = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (link)));
3122 constraint_len = strlen (constraint);
3123 if (constraint_len == 0)
3126 parse_output_constraint (&constraint, i, 0, 0,
3127 &allows_mem, &allows_reg, &is_inout);
3129 if (!allows_reg && allows_mem)
3130 lang_hooks.mark_addressable (TREE_VALUE (link));
3132 tret = gimplify_expr (&TREE_VALUE (link), pre_p, post_p,
3133 is_inout ? is_gimple_min_lval : is_gimple_lvalue,
3134 fb_lvalue | fb_mayfail);
3135 if (tret == GS_ERROR)
3137 error ("invalid lvalue in asm output %d", i);
3143 /* An input/output operand. To give the optimizers more
3144 flexibility, split it into separate input and output
3149 /* Turn the in/out constraint into an output constraint. */
3150 char *p = xstrdup (constraint);
3152 TREE_VALUE (TREE_PURPOSE (link)) = build_string (constraint_len, p);
3155 /* And add a matching input constraint. */
3158 sprintf (buf, "%d", i);
3159 input = build_string (strlen (buf), buf);
3162 input = build_string (constraint_len - 1, constraint + 1);
3163 input = build_tree_list (build_tree_list (NULL_TREE, input),
3164 unshare_expr (TREE_VALUE (link)));
3165 ASM_INPUTS (expr) = chainon (ASM_INPUTS (expr), input);
3169 for (link = ASM_INPUTS (expr); link; ++i, link = TREE_CHAIN (link))
3172 = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (link)));
3173 parse_input_constraint (&constraint, 0, 0, noutputs, 0,
3174 oconstraints, &allows_mem, &allows_reg);
3176 /* If the operand is a memory input, it should be an lvalue. */
3177 if (!allows_reg && allows_mem)
3179 lang_hooks.mark_addressable (TREE_VALUE (link));
3180 tret = gimplify_expr (&TREE_VALUE (link), pre_p, post_p,
3181 is_gimple_lvalue, fb_lvalue | fb_mayfail);
3182 if (tret == GS_ERROR)
3184 error ("memory input %d is not directly addressable", i);
3190 tret = gimplify_expr (&TREE_VALUE (link), pre_p, post_p,
3191 is_gimple_asm_val, fb_rvalue);
3192 if (tret == GS_ERROR)
3200 /* Gimplify a CLEANUP_POINT_EXPR. Currently this works by adding
3201 WITH_CLEANUP_EXPRs to the prequeue as we encounter cleanups while
3202 gimplifying the body, and converting them to TRY_FINALLY_EXPRs when we
3203 return to this function.
3205 FIXME should we complexify the prequeue handling instead? Or use flags
3206 for all the cleanups and let the optimizer tighten them up? The current
3207 code seems pretty fragile; it will break on a cleanup within any
3208 non-conditional nesting. But any such nesting would be broken, anyway;
3209 we can't write a TRY_FINALLY_EXPR that starts inside a nesting construct
3210 and continues out of it. We can do that at the RTL level, though, so
3211 having an optimizer to tighten up try/finally regions would be a Good
3214 static enum gimplify_status
3215 gimplify_cleanup_point_expr (tree *expr_p, tree *pre_p)
3217 tree_stmt_iterator iter;
3220 tree temp = voidify_wrapper_expr (*expr_p, NULL);
3222 /* We only care about the number of conditions between the innermost
3223 CLEANUP_POINT_EXPR and the cleanup. So save and reset the count. */
3224 int old_conds = gimplify_ctxp->conditions;
3225 gimplify_ctxp->conditions = 0;
3227 body = TREE_OPERAND (*expr_p, 0);
3228 gimplify_to_stmt_list (&body);
3230 gimplify_ctxp->conditions = old_conds;
3232 for (iter = tsi_start (body); !tsi_end_p (iter); )
3234 tree *wce_p = tsi_stmt_ptr (iter);
3237 if (TREE_CODE (wce) == WITH_CLEANUP_EXPR)
3239 if (tsi_one_before_end_p (iter))
3241 tsi_link_before (&iter, TREE_OPERAND (wce, 0), TSI_SAME_STMT);
3248 enum tree_code code;
3250 if (CLEANUP_EH_ONLY (wce))
3251 code = TRY_CATCH_EXPR;
3253 code = TRY_FINALLY_EXPR;
3255 sl = tsi_split_statement_list_after (&iter);
3256 tfe = build (code, void_type_node, sl, NULL_TREE);
3257 append_to_statement_list (TREE_OPERAND (wce, 0),
3258 &TREE_OPERAND (tfe, 1));
3260 iter = tsi_start (sl);
3270 append_to_statement_list (body, pre_p);
3280 /* Insert a cleanup marker for gimplify_cleanup_point_expr. CLEANUP
3281 is the cleanup action required. */
3284 gimple_push_cleanup (tree var, tree cleanup, bool eh_only, tree *pre_p)
3288 /* Errors can result in improperly nested cleanups. Which results in
3289 confusion when trying to resolve the WITH_CLEANUP_EXPR. */
3290 if (errorcount || sorrycount)
3293 if (gimple_conditional_context ())
3295 /* If we're in a conditional context, this is more complex. We only
3296 want to run the cleanup if we actually ran the initialization that
3297 necessitates it, but we want to run it after the end of the
3298 conditional context. So we wrap the try/finally around the
3299 condition and use a flag to determine whether or not to actually
3300 run the destructor. Thus
3304 becomes (approximately)
3308 if (test) { A::A(temp); flag = 1; val = f(temp); }
3311 if (flag) A::~A(temp);
3316 tree flag = create_tmp_var (boolean_type_node, "cleanup");
3317 tree ffalse = build (MODIFY_EXPR, void_type_node, flag,
3318 boolean_false_node);
3319 tree ftrue = build (MODIFY_EXPR, void_type_node, flag,
3321 cleanup = build (COND_EXPR, void_type_node, flag, cleanup, NULL);
3322 wce = build (WITH_CLEANUP_EXPR, void_type_node, cleanup);
3323 append_to_statement_list (ffalse, &gimplify_ctxp->conditional_cleanups);
3324 append_to_statement_list (wce, &gimplify_ctxp->conditional_cleanups);
3325 append_to_statement_list (ftrue, pre_p);
3327 /* Because of this manipulation, and the EH edges that jump
3328 threading cannot redirect, the temporary (VAR) will appear
3329 to be used uninitialized. Don't warn. */
3330 TREE_NO_WARNING (var) = 1;
3334 wce = build (WITH_CLEANUP_EXPR, void_type_node, cleanup);
3335 CLEANUP_EH_ONLY (wce) = eh_only;
3336 append_to_statement_list (wce, pre_p);
3339 gimplify_stmt (&TREE_OPERAND (wce, 0));
3342 /* Gimplify a TARGET_EXPR which doesn't appear on the rhs of an INIT_EXPR. */
3344 static enum gimplify_status
3345 gimplify_target_expr (tree *expr_p, tree *pre_p, tree *post_p)
3347 tree targ = *expr_p;
3348 tree temp = TARGET_EXPR_SLOT (targ);
3349 tree init = TARGET_EXPR_INITIAL (targ);
3350 enum gimplify_status ret;
3354 /* TARGET_EXPR temps aren't part of the enclosing block, so add it
3355 to the temps list. */
3356 gimple_add_tmp_var (temp);
3358 /* If TARGET_EXPR_INITIAL is void, then the mere evaluation of the
3359 expression is supposed to initialize the slot. */
3360 if (VOID_TYPE_P (TREE_TYPE (init)))
3361 ret = gimplify_expr (&init, pre_p, post_p, is_gimple_stmt, fb_none);
3364 /* Special handling for BIND_EXPR can result in fewer temps. */
3366 if (TREE_CODE (init) == BIND_EXPR)
3367 gimplify_bind_expr (&init, temp, pre_p);
3370 init = build (MODIFY_EXPR, void_type_node, temp, init);
3371 ret = gimplify_expr (&init, pre_p, post_p, is_gimple_stmt,
3375 if (ret == GS_ERROR)
3377 append_to_statement_list (init, pre_p);
3379 /* If needed, push the cleanup for the temp. */
3380 if (TARGET_EXPR_CLEANUP (targ))
3382 gimplify_stmt (&TARGET_EXPR_CLEANUP (targ));
3383 gimple_push_cleanup (temp, TARGET_EXPR_CLEANUP (targ),
3384 CLEANUP_EH_ONLY (targ), pre_p);
3387 /* Only expand this once. */
3388 TREE_OPERAND (targ, 3) = init;
3389 TARGET_EXPR_INITIAL (targ) = NULL_TREE;
3392 /* We should have expanded this before. */
3393 gcc_assert (DECL_SEEN_IN_BIND_EXPR_P (temp));
3399 /* Gimplification of expression trees. */
3401 /* Gimplify an expression which appears at statement context; usually, this
3402 means replacing it with a suitably gimple STATEMENT_LIST. */
3405 gimplify_stmt (tree *stmt_p)
3407 gimplify_expr (stmt_p, NULL, NULL, is_gimple_stmt, fb_none);
3410 /* Similarly, but force the result to be a STATEMENT_LIST. */
3413 gimplify_to_stmt_list (tree *stmt_p)
3415 gimplify_stmt (stmt_p);
3417 *stmt_p = alloc_stmt_list ();
3418 else if (TREE_CODE (*stmt_p) != STATEMENT_LIST)
3421 *stmt_p = alloc_stmt_list ();
3422 append_to_statement_list (t, stmt_p);
3427 /* Gimplifies the expression tree pointed by EXPR_P. Return 0 if
3428 gimplification failed.
3430 PRE_P points to the list where side effects that must happen before
3431 EXPR should be stored.
3433 POST_P points to the list where side effects that must happen after
3434 EXPR should be stored, or NULL if there is no suitable list. In
3435 that case, we copy the result to a temporary, emit the
3436 post-effects, and then return the temporary.
3438 GIMPLE_TEST_F points to a function that takes a tree T and
3439 returns nonzero if T is in the GIMPLE form requested by the
3440 caller. The GIMPLE predicates are in tree-gimple.c.
3442 This test is used twice. Before gimplification, the test is
3443 invoked to determine whether *EXPR_P is already gimple enough. If
3444 that fails, *EXPR_P is gimplified according to its code and
3445 GIMPLE_TEST_F is called again. If the test still fails, then a new
3446 temporary variable is created and assigned the value of the
3447 gimplified expression.
3449 FALLBACK tells the function what sort of a temporary we want. If the 1
3450 bit is set, an rvalue is OK. If the 2 bit is set, an lvalue is OK.
3451 If both are set, either is OK, but an lvalue is preferable.
3453 The return value is either GS_ERROR or GS_ALL_DONE, since this function
3454 iterates until solution. */
3456 enum gimplify_status
3457 gimplify_expr (tree *expr_p, tree *pre_p, tree *post_p,
3458 bool (* gimple_test_f) (tree), fallback_t fallback)
3461 tree internal_pre = NULL_TREE;
3462 tree internal_post = NULL_TREE;
3464 int is_statement = (pre_p == NULL);
3465 location_t saved_location;
3466 enum gimplify_status ret;
3468 save_expr = *expr_p;
3469 if (save_expr == NULL_TREE)
3472 /* We used to check the predicate here and return immediately if it
3473 succeeds. This is wrong; the design is for gimplification to be
3474 idempotent, and for the predicates to only test for valid forms, not
3475 whether they are fully simplified. */
3477 /* Set up our internal queues if needed. */
3479 pre_p = &internal_pre;
3481 post_p = &internal_post;
3483 saved_location = input_location;
3484 if (save_expr != error_mark_node
3485 && EXPR_HAS_LOCATION (*expr_p))
3486 input_location = EXPR_LOCATION (*expr_p);
3488 /* Loop over the specific gimplifiers until the toplevel node
3489 remains the same. */
3492 /* Strip away as many useless type conversions as possible
3494 STRIP_USELESS_TYPE_CONVERSION (*expr_p);
3496 /* Remember the expr. */
3497 save_expr = *expr_p;
3499 /* Die, die, die, my darling. */
3500 if (save_expr == error_mark_node
3501 || (TREE_TYPE (save_expr)
3502 && TREE_TYPE (save_expr) == error_mark_node))
3508 /* Do any language-specific gimplification. */
3509 ret = lang_hooks.gimplify_expr (expr_p, pre_p, post_p);
3512 if (*expr_p == NULL_TREE)
3514 if (*expr_p != save_expr)
3517 else if (ret != GS_UNHANDLED)
3521 switch (TREE_CODE (*expr_p))
3523 /* First deal with the special cases. */
3525 case POSTINCREMENT_EXPR:
3526 case POSTDECREMENT_EXPR:
3527 case PREINCREMENT_EXPR:
3528 case PREDECREMENT_EXPR:
3529 ret = gimplify_self_mod_expr (expr_p, pre_p, post_p,
3530 fallback != fb_none);
3534 case ARRAY_RANGE_REF:
3538 case VIEW_CONVERT_EXPR:
3539 ret = gimplify_compound_lval (expr_p, pre_p, post_p,
3540 fallback ? fallback : fb_rvalue);
3544 ret = gimplify_cond_expr (expr_p, pre_p, NULL_TREE);
3548 ret = gimplify_call_expr (expr_p, pre_p, fallback != fb_none);
3555 ret = gimplify_compound_expr (expr_p, pre_p, fallback != fb_none);
3560 ret = gimplify_modify_expr (expr_p, pre_p, post_p,
3561 fallback != fb_none);
3564 case TRUTH_ANDIF_EXPR:
3565 case TRUTH_ORIF_EXPR:
3566 ret = gimplify_boolean_expr (expr_p);
3569 case TRUTH_NOT_EXPR:
3570 TREE_OPERAND (*expr_p, 0)
3571 = gimple_boolify (TREE_OPERAND (*expr_p, 0));
3572 ret = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p, post_p,
3573 is_gimple_val, fb_rvalue);
3574 recalculate_side_effects (*expr_p);
3578 ret = gimplify_addr_expr (expr_p, pre_p, post_p);
3582 ret = gimplify_va_arg_expr (expr_p, pre_p, post_p);
3587 if (IS_EMPTY_STMT (*expr_p))
3593 if (VOID_TYPE_P (TREE_TYPE (*expr_p))
3594 || fallback == fb_none)
3596 /* Just strip a conversion to void (or in void context) and
3598 *expr_p = TREE_OPERAND (*expr_p, 0);
3602 ret = gimplify_conversion (expr_p);
3603 if (ret == GS_ERROR)
3605 if (*expr_p != save_expr)
3609 case FIX_TRUNC_EXPR:
3611 case FIX_FLOOR_EXPR:
3612 case FIX_ROUND_EXPR:
3613 /* unary_expr: ... | '(' cast ')' val | ... */
3614 ret = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p, post_p,
3615 is_gimple_val, fb_rvalue);
3616 recalculate_side_effects (*expr_p);
3619 case ALIGN_INDIRECT_REF:
3620 case MISALIGNED_INDIRECT_REF:
3622 ret = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p, post_p,
3623 is_gimple_reg, fb_rvalue);
3624 recalculate_side_effects (*expr_p);
3627 /* Constants need not be gimplified. */
3637 /* If we require an lvalue, such as for ADDR_EXPR, retain the
3638 CONST_DECL node. Otherwise the decl is replaceable by its
3640 /* ??? Should be == fb_lvalue, but ADDR_EXPR passes fb_either. */
3641 if (fallback & fb_lvalue)
3644 *expr_p = DECL_INITIAL (*expr_p);
3648 ret = gimplify_decl_expr (expr_p);
3652 /* FIXME make this a decl. */
3657 ret = gimplify_bind_expr (expr_p, NULL, pre_p);
3661 ret = gimplify_loop_expr (expr_p, pre_p);
3665 ret = gimplify_switch_expr (expr_p, pre_p);
3669 ret = gimplify_exit_expr (expr_p);
3673 /* If the target is not LABEL, then it is a computed jump
3674 and the target needs to be gimplified. */
3675 if (TREE_CODE (GOTO_DESTINATION (*expr_p)) != LABEL_DECL)
3676 ret = gimplify_expr (&GOTO_DESTINATION (*expr_p), pre_p,
3677 NULL, is_gimple_val, fb_rvalue);
3682 gcc_assert (decl_function_context (LABEL_EXPR_LABEL (*expr_p))
3683 == current_function_decl);
3686 case CASE_LABEL_EXPR:
3687 ret = gimplify_case_label_expr (expr_p);
3691 ret = gimplify_return_expr (*expr_p, pre_p);
3695 /* Don't reduce this in place; let gimplify_init_constructor work its
3696 magic. Buf if we're just elaborating this for side effects, just
3697 gimplify any element that has side-effects. */
3698 if (fallback == fb_none)
3700 for (tmp = CONSTRUCTOR_ELTS (*expr_p); tmp;
3701 tmp = TREE_CHAIN (tmp))
3702 if (TREE_SIDE_EFFECTS (TREE_VALUE (tmp)))
3703 gimplify_expr (&TREE_VALUE (tmp), pre_p, post_p,
3704 gimple_test_f, fallback);
3706 *expr_p = NULL_TREE;
3712 /* The following are special cases that are not handled by the
3713 original GIMPLE grammar. */
3715 /* SAVE_EXPR nodes are converted into a GIMPLE identifier and
3718 ret = gimplify_save_expr (expr_p, pre_p, post_p);
3723 enum gimplify_status r0, r1, r2;
3725 r0 = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p, post_p,
3726 is_gimple_lvalue, fb_either);
3727 r1 = gimplify_expr (&TREE_OPERAND (*expr_p, 1), pre_p, post_p,
3728 is_gimple_val, fb_rvalue);
3729 r2 = gimplify_expr (&TREE_OPERAND (*expr_p, 2), pre_p, post_p,
3730 is_gimple_val, fb_rvalue);
3731 recalculate_side_effects (*expr_p);
3733 ret = MIN (r0, MIN (r1, r2));
3737 case NON_LVALUE_EXPR:
3738 /* This should have been stripped above. */
3742 ret = gimplify_asm_expr (expr_p, pre_p, post_p);
3745 case TRY_FINALLY_EXPR:
3746 case TRY_CATCH_EXPR:
3747 gimplify_to_stmt_list (&TREE_OPERAND (*expr_p, 0));
3748 gimplify_to_stmt_list (&TREE_OPERAND (*expr_p, 1));
3752 case CLEANUP_POINT_EXPR:
3753 ret = gimplify_cleanup_point_expr (expr_p, pre_p);
3757 ret = gimplify_target_expr (expr_p, pre_p, post_p);
3761 gimplify_to_stmt_list (&CATCH_BODY (*expr_p));
3765 case EH_FILTER_EXPR:
3766 gimplify_to_stmt_list (&EH_FILTER_FAILURE (*expr_p));
3772 enum gimplify_status r0, r1;
3773 r0 = gimplify_expr (&OBJ_TYPE_REF_OBJECT (*expr_p), pre_p, post_p,
3774 is_gimple_val, fb_rvalue);
3775 r1 = gimplify_expr (&OBJ_TYPE_REF_EXPR (*expr_p), pre_p, post_p,
3776 is_gimple_val, fb_rvalue);
3782 /* We get here when taking the address of a label. We mark
3783 the label as "forced"; meaning it can never be removed and
3784 it is a potential target for any computed goto. */
3785 FORCED_LABEL (*expr_p) = 1;
3789 case STATEMENT_LIST:
3790 ret = gimplify_statement_list (expr_p);
3793 case WITH_SIZE_EXPR:
3795 enum gimplify_status r0, r1;
3796 r0 = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p,
3797 post_p == &internal_post ? NULL : post_p,
3798 gimple_test_f, fallback);
3799 r1 = gimplify_expr (&TREE_OPERAND (*expr_p, 1), pre_p, post_p,
3800 is_gimple_val, fb_rvalue);
3805 /* ??? If this is a local variable, and it has not been seen in any
3806 outer BIND_EXPR, then it's probably the result of a duplicate
3807 declaration, for which we've already issued an error. It would
3808 be really nice if the front end wouldn't leak these at all.
3809 Currently the only known culprit is C++ destructors, as seen
3810 in g++.old-deja/g++.jason/binding.C. */
3812 if (!TREE_STATIC (tmp) && !DECL_EXTERNAL (tmp)
3813 && decl_function_context (tmp) == current_function_decl
3814 && !DECL_SEEN_IN_BIND_EXPR_P (tmp))
3816 gcc_assert (errorcount || sorrycount);
3821 /* If this is a local variable sized decl, it must be accessed
3822 indirectly. Perform that substitution. */
3823 if (DECL_VALUE_EXPR (tmp))
3825 *expr_p = unshare_expr (DECL_VALUE_EXPR (tmp));
3834 /* Allow callbacks into the gimplifier during optimization. */
3839 switch (TREE_CODE_CLASS (TREE_CODE (*expr_p)))
3841 case tcc_comparison:
3842 /* If this is a comparison of objects of aggregate type,
3843 handle it specially (by converting to a call to
3844 memcmp). It would be nice to only have to do this
3845 for variable-sized objects, but then we'd have to
3846 allow the same nest of reference nodes we allow for
3847 MODIFY_EXPR and that's too complex. */
3848 if (!AGGREGATE_TYPE_P (TREE_TYPE (TREE_OPERAND (*expr_p, 1))))
3850 ret = gimplify_variable_sized_compare (expr_p);
3853 /* If *EXPR_P does not need to be special-cased, handle it
3854 according to its class. */
3856 ret = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p,
3857 post_p, is_gimple_val, fb_rvalue);
3863 enum gimplify_status r0, r1;
3865 r0 = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p,
3866 post_p, is_gimple_val, fb_rvalue);
3867 r1 = gimplify_expr (&TREE_OPERAND (*expr_p, 1), pre_p,
3868 post_p, is_gimple_val, fb_rvalue);
3874 case tcc_declaration:
3877 goto dont_recalculate;
3880 gcc_assert (TREE_CODE (*expr_p) == TRUTH_AND_EXPR
3881 || TREE_CODE (*expr_p) == TRUTH_OR_EXPR
3882 || TREE_CODE (*expr_p) == TRUTH_XOR_EXPR);
3886 recalculate_side_effects (*expr_p);
3891 /* If we replaced *expr_p, gimplify again. */
3892 if (ret == GS_OK && (*expr_p == NULL || *expr_p == save_expr))
3895 while (ret == GS_OK);
3897 /* If we encountered an error_mark somewhere nested inside, either
3898 stub out the statement or propagate the error back out. */
3899 if (ret == GS_ERROR)
3906 /* This was only valid as a return value from the langhook, which
3907 we handled. Make sure it doesn't escape from any other context. */
3908 gcc_assert (ret != GS_UNHANDLED);
3910 if (fallback == fb_none && *expr_p && !is_gimple_stmt (*expr_p))
3912 /* We aren't looking for a value, and we don't have a valid
3913 statement. If it doesn't have side-effects, throw it away. */
3914 if (!TREE_SIDE_EFFECTS (*expr_p))
3916 else if (!TREE_THIS_VOLATILE (*expr_p))
3918 /* This is probably a _REF that contains something nested that
3919 has side effects. Recurse through the operands to find it. */
3920 enum tree_code code = TREE_CODE (*expr_p);
3925 case REALPART_EXPR: case IMAGPART_EXPR:
3926 gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p, post_p,
3927 gimple_test_f, fallback);
3930 case ARRAY_REF: case ARRAY_RANGE_REF:
3931 gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p, post_p,
3932 gimple_test_f, fallback);
3933 gimplify_expr (&TREE_OPERAND (*expr_p, 1), pre_p, post_p,
3934 gimple_test_f, fallback);
3938 /* Anything else with side-effects must be converted to
3939 a valid statement before we get here. */
3945 else if (COMPLETE_TYPE_P (TREE_TYPE (*expr_p)))
3947 /* Historically, the compiler has treated a bare
3948 reference to a volatile lvalue as forcing a load. */
3949 tree tmp = create_tmp_var (TREE_TYPE (*expr_p), "vol");
3950 *expr_p = build (MODIFY_EXPR, TREE_TYPE (tmp), tmp, *expr_p);
3953 /* We can't do anything useful with a volatile reference to
3954 incomplete type, so just throw it away. */
3958 /* If we are gimplifying at the statement level, we're done. Tack
3959 everything together and replace the original statement with the
3961 if (fallback == fb_none || is_statement)
3963 if (internal_pre || internal_post)
3965 append_to_statement_list (*expr_p, &internal_pre);
3966 append_to_statement_list (internal_post, &internal_pre);
3967 annotate_all_with_locus (&internal_pre, input_location);
3968 *expr_p = internal_pre;
3972 else if (TREE_CODE (*expr_p) == STATEMENT_LIST)
3973 annotate_all_with_locus (expr_p, input_location);
3975 annotate_one_with_locus (*expr_p, input_location);
3979 /* Otherwise we're gimplifying a subexpression, so the resulting value is
3982 /* If it's sufficiently simple already, we're done. Unless we are
3983 handling some post-effects internally; if that's the case, we need to
3984 copy into a temp before adding the post-effects to the tree. */
3985 if (!internal_post && (*gimple_test_f) (*expr_p))
3988 /* Otherwise, we need to create a new temporary for the gimplified
3991 /* We can't return an lvalue if we have an internal postqueue. The
3992 object the lvalue refers to would (probably) be modified by the
3993 postqueue; we need to copy the value out first, which means an
3995 if ((fallback & fb_lvalue) && !internal_post
3996 && is_gimple_addressable (*expr_p))
3998 /* An lvalue will do. Take the address of the expression, store it
3999 in a temporary, and replace the expression with an INDIRECT_REF of
4001 tmp = build_fold_addr_expr (*expr_p);
4002 gimplify_expr (&tmp, pre_p, post_p, is_gimple_reg, fb_rvalue);
4003 *expr_p = build1 (INDIRECT_REF, TREE_TYPE (TREE_TYPE (tmp)), tmp);
4005 else if ((fallback & fb_rvalue) && is_gimple_formal_tmp_rhs (*expr_p))
4007 gcc_assert (!VOID_TYPE_P (TREE_TYPE (*expr_p)));
4009 /* An rvalue will do. Assign the gimplified expression into a new
4010 temporary TMP and replace the original expression with TMP. */
4012 if (internal_post || (fallback & fb_lvalue))
4013 /* The postqueue might change the value of the expression between
4014 the initialization and use of the temporary, so we can't use a
4015 formal temp. FIXME do we care? */
4016 *expr_p = get_initialized_tmp_var (*expr_p, pre_p, post_p);
4018 *expr_p = get_formal_tmp_var (*expr_p, pre_p);
4020 if (TREE_CODE (*expr_p) != SSA_NAME)
4021 DECL_GIMPLE_FORMAL_TEMP_P (*expr_p) = 1;
4025 #ifdef ENABLE_CHECKING
4026 if (!(fallback & fb_mayfail))
4028 fprintf (stderr, "gimplification failed:\n");
4029 print_generic_expr (stderr, *expr_p, 0);
4030 debug_tree (*expr_p);
4031 internal_error ("gimplification failed");
4034 gcc_assert (fallback & fb_mayfail);
4035 /* If this is an asm statement, and the user asked for the
4036 impossible, don't abort. Fail and let gimplify_asm_expr
4042 /* Make sure the temporary matches our predicate. */
4043 gcc_assert ((*gimple_test_f) (*expr_p));
4047 annotate_all_with_locus (&internal_post, input_location);
4048 append_to_statement_list (internal_post, pre_p);
4052 input_location = saved_location;
4056 /* Look through TYPE for variable-sized objects and gimplify each such
4057 size that we find. Add to LIST_P any statements generated. */
4060 gimplify_type_sizes (tree type, tree *list_p)
4064 switch (TREE_CODE (type))
4074 gimplify_one_sizepos (&TYPE_MIN_VALUE (type), list_p);
4075 gimplify_one_sizepos (&TYPE_MAX_VALUE (type), list_p);
4079 /* These anonymous types don't have declarations, so handle them here. */
4080 gimplify_type_sizes (TYPE_DOMAIN (type), list_p);
4085 case QUAL_UNION_TYPE:
4086 for (field = TYPE_FIELDS (type); field; field = TREE_CHAIN (field))
4087 if (TREE_CODE (field) == FIELD_DECL)
4088 gimplify_one_sizepos (&DECL_FIELD_OFFSET (field), list_p);
4095 gimplify_one_sizepos (&TYPE_SIZE (type), list_p);
4096 gimplify_one_sizepos (&TYPE_SIZE_UNIT (type), list_p);
4099 /* Subroutine of the above to gimplify one size or position, *EXPR_P.
4100 We add any required statements to STMT_P. */
4103 gimplify_one_sizepos (tree *expr_p, tree *stmt_p)
4105 /* We don't do anything if the value isn't there, is constant, or contains
4106 A PLACEHOLDER_EXPR. We also don't want to do anything if it's already
4107 a VAR_DECL. If it's a VAR_DECL from another function, the gimplfier
4108 will want to replace it with a new variable, but that will cause problems
4109 if this type is from outside the function. It's OK to have that here. */
4110 if (*expr_p == NULL_TREE || TREE_CONSTANT (*expr_p)
4111 || TREE_CODE (*expr_p) == VAR_DECL
4112 || CONTAINS_PLACEHOLDER_P (*expr_p))
4115 gimplify_expr (expr_p, stmt_p, NULL, is_gimple_val, fb_rvalue);
4118 #ifdef ENABLE_CHECKING
4119 /* Compare types A and B for a "close enough" match. */
4122 cpt_same_type (tree a, tree b)
4124 if (lang_hooks.types_compatible_p (a, b))
4127 /* ??? The C++ FE decomposes METHOD_TYPES to FUNCTION_TYPES and doesn't
4128 link them together. This routine is intended to catch type errors
4129 that will affect the optimizers, and the optimizers don't add new
4130 dereferences of function pointers, so ignore it. */
4131 if ((TREE_CODE (a) == FUNCTION_TYPE || TREE_CODE (a) == METHOD_TYPE)
4132 && (TREE_CODE (b) == FUNCTION_TYPE || TREE_CODE (b) == METHOD_TYPE))
4135 /* ??? The C FE pushes type qualifiers after the fact into the type of
4136 the element from the type of the array. See build_unary_op's handling
4137 of ADDR_EXPR. This seems wrong -- if we were going to do this, we
4138 should have done it when creating the variable in the first place.
4139 Alternately, why aren't the two array types made variants? */
4140 if (TREE_CODE (a) == ARRAY_TYPE && TREE_CODE (b) == ARRAY_TYPE)
4141 return cpt_same_type (TREE_TYPE (a), TREE_TYPE (b));
4143 /* And because of those, we have to recurse down through pointers. */
4144 if (POINTER_TYPE_P (a) && POINTER_TYPE_P (b))
4145 return cpt_same_type (TREE_TYPE (a), TREE_TYPE (b));
4150 /* Check for some cases of the front end missing cast expressions.
4151 The type of a dereference should correspond to the pointer type;
4152 similarly the type of an address should match its object. */
4155 check_pointer_types_r (tree *tp, int *walk_subtrees ATTRIBUTE_UNUSED,
4156 void *data ATTRIBUTE_UNUSED)
4159 tree ptype, otype, dtype;
4161 switch (TREE_CODE (t))
4165 otype = TREE_TYPE (t);
4166 ptype = TREE_TYPE (TREE_OPERAND (t, 0));
4167 dtype = TREE_TYPE (ptype);
4168 gcc_assert (cpt_same_type (otype, dtype));
4172 ptype = TREE_TYPE (t);
4173 otype = TREE_TYPE (TREE_OPERAND (t, 0));
4174 dtype = TREE_TYPE (ptype);
4175 if (!cpt_same_type (otype, dtype))
4177 /* &array is allowed to produce a pointer to the element, rather than
4178 a pointer to the array type. We must allow this in order to
4179 properly represent assigning the address of an array in C into
4180 pointer to the element type. */
4181 gcc_assert (TREE_CODE (otype) == ARRAY_TYPE
4182 && POINTER_TYPE_P (ptype)
4183 && cpt_same_type (TREE_TYPE (otype), dtype));
4197 /* Gimplify the body of statements pointed by BODY_P. FNDECL is the
4198 function decl containing BODY. */
4201 gimplify_body (tree *body_p, tree fndecl)
4203 location_t saved_location = input_location;
4206 timevar_push (TV_TREE_GIMPLIFY);
4207 push_gimplify_context ();
4209 /* Unshare most shared trees in the body and in that of any nested functions.
4210 It would seem we don't have to do this for nested functions because
4211 they are supposed to be output and then the outer function gimplified
4212 first, but the g++ front end doesn't always do it that way. */
4213 unshare_body (body_p, fndecl);
4214 unvisit_body (body_p, fndecl);
4216 /* Make sure input_location isn't set to something wierd. */
4217 input_location = DECL_SOURCE_LOCATION (fndecl);
4219 /* Gimplify the function's body. */
4220 gimplify_stmt (body_p);
4223 /* Unshare again, in case gimplification was sloppy. */
4224 unshare_all_trees (body);
4227 body = alloc_stmt_list ();
4228 else if (TREE_CODE (body) == STATEMENT_LIST)
4230 tree t = expr_only (*body_p);
4235 /* If there isn't an outer BIND_EXPR, add one. */
4236 if (TREE_CODE (body) != BIND_EXPR)
4238 tree b = build (BIND_EXPR, void_type_node, NULL_TREE,
4239 NULL_TREE, NULL_TREE);
4240 TREE_SIDE_EFFECTS (b) = 1;
4241 append_to_statement_list_force (body, &BIND_EXPR_BODY (b));
4246 pop_gimplify_context (body);
4248 #ifdef ENABLE_CHECKING
4249 walk_tree (body_p, check_pointer_types_r, NULL, NULL);
4252 timevar_pop (TV_TREE_GIMPLIFY);
4253 input_location = saved_location;
4256 /* Entry point to the gimplification pass. FNDECL is the FUNCTION_DECL
4257 node for the function we want to gimplify. */
4260 gimplify_function_tree (tree fndecl)
4264 oldfn = current_function_decl;
4265 current_function_decl = fndecl;
4267 gimplify_body (&DECL_SAVED_TREE (fndecl), fndecl);
4269 /* If we're instrumenting function entry/exit, then prepend the call to
4270 the entry hook and wrap the whole function in a TRY_FINALLY_EXPR to
4271 catch the exit hook. */
4272 /* ??? Add some way to ignore exceptions for this TFE. */
4273 if (flag_instrument_function_entry_exit
4274 && ! DECL_NO_INSTRUMENT_FUNCTION_ENTRY_EXIT (fndecl))
4278 tf = build (TRY_FINALLY_EXPR, void_type_node, NULL, NULL);
4279 TREE_SIDE_EFFECTS (tf) = 1;
4280 x = DECL_SAVED_TREE (fndecl);
4281 append_to_statement_list (x, &TREE_OPERAND (tf, 0));
4282 x = implicit_built_in_decls[BUILT_IN_PROFILE_FUNC_EXIT];
4283 x = build_function_call_expr (x, NULL);
4284 append_to_statement_list (x, &TREE_OPERAND (tf, 1));
4286 bind = build (BIND_EXPR, void_type_node, NULL, NULL, NULL);
4287 TREE_SIDE_EFFECTS (bind) = 1;
4288 x = implicit_built_in_decls[BUILT_IN_PROFILE_FUNC_ENTER];
4289 x = build_function_call_expr (x, NULL);
4290 append_to_statement_list (x, &BIND_EXPR_BODY (bind));
4291 append_to_statement_list (tf, &BIND_EXPR_BODY (bind));
4293 DECL_SAVED_TREE (fndecl) = bind;
4296 current_function_decl = oldfn;
4300 /* Expands EXPR to list of gimple statements STMTS. If SIMPLE is true,
4301 force the result to be either ssa_name or an invariant, otherwise
4302 just force it to be a rhs expression. If VAR is not NULL, make the
4303 base variable of the final destination be VAR if suitable. */
4306 force_gimple_operand (tree expr, tree *stmts, bool simple, tree var)
4309 enum gimplify_status ret;
4310 gimple_predicate gimple_test_f;
4314 if (is_gimple_val (expr))
4317 gimple_test_f = simple ? is_gimple_val : is_gimple_reg_rhs;
4319 push_gimplify_context ();
4320 gimplify_ctxp->into_ssa = true;
4323 expr = build (MODIFY_EXPR, TREE_TYPE (var), var, expr);
4325 ret = gimplify_expr (&expr, stmts, NULL,
4326 gimple_test_f, fb_rvalue);
4327 gcc_assert (ret != GS_ERROR);
4329 for (t = gimplify_ctxp->temps; t ; t = TREE_CHAIN (t))
4330 add_referenced_tmp_var (t);
4332 pop_gimplify_context (NULL);
4337 #include "gt-gimplify.h"