1 /* Tree lowering pass. This pass converts the GENERIC functions-as-trees
2 tree representation into the GIMPLE form.
4 Copyright (C) 2002, 2003, 2004 Free Software Foundation, Inc.
5 Major work done by Sebastian Pop <s.pop@laposte.net>,
6 Diego Novillo <dnovillo@redhat.com> and Jason Merrill <jason@redhat.com>.
8 This file is part of GCC.
10 GCC is free software; you can redistribute it and/or modify it under
11 the terms of the GNU General Public License as published by the Free
12 Software Foundation; either version 2, or (at your option) any later
15 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
16 WARRANTY; without even the implied warranty of MERCHANTABILITY or
17 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
20 You should have received a copy of the GNU General Public License
21 along with GCC; see the file COPYING. If not, write to the Free
22 Software Foundation, 59 Temple Place - Suite 330, Boston, MA
27 #include "coretypes.h"
33 #include "tree-gimple.h"
34 #include "tree-inline.h"
35 #include "diagnostic.h"
36 #include "langhooks.h"
37 #include "langhooks-def.h"
38 #include "tree-flow.h"
49 static struct gimplify_ctx
51 tree current_bind_expr;
54 tree conditional_cleanups;
57 varray_type case_labels;
58 /* The formal temporary table. Should this be persistent? */
63 /* Formal (expression) temporary table handling: Multiple occurrences of
64 the same scalar expression are evaluated into the same temporary. */
66 typedef struct gimple_temp_hash_elt
69 tree temp; /* Value */
72 /* Return a hash value for a formal temporary table entry. */
75 gimple_tree_hash (const void *p)
77 tree t = ((const elt_t *)p)->val;
78 return iterative_hash_expr (t, 0);
81 /* Compare two formal temporary table entries. */
84 gimple_tree_eq (const void *p1, const void *p2)
86 tree t1 = ((const elt_t *)p1)->val;
87 tree t2 = ((const elt_t *)p2)->val;
88 enum tree_code code = TREE_CODE (t1);
90 if (TREE_CODE (t2) != code
91 || TREE_TYPE (t1) != TREE_TYPE (t2))
94 if (!operand_equal_p (t1, t2, 0))
97 /* Only allow them to compare equal if they also hash equal; otherwise
98 results are nondeterminate, and we fail bootstrap comparison. */
99 if (gimple_tree_hash (p1) != gimple_tree_hash (p2))
105 /* Set up a context for the gimplifier. */
108 push_gimplify_context (void)
113 = (struct gimplify_ctx *) xcalloc (1, sizeof (struct gimplify_ctx));
114 gimplify_ctxp->temp_htab
115 = htab_create (1000, gimple_tree_hash, gimple_tree_eq, free);
118 /* Tear down a context for the gimplifier. If BODY is non-null, then
119 put the temporaries into the outer BIND_EXPR. Otherwise, put them
120 in the unexpanded_var_list. */
123 pop_gimplify_context (tree body)
125 if (!gimplify_ctxp || gimplify_ctxp->current_bind_expr)
129 declare_tmp_vars (gimplify_ctxp->temps, body);
131 record_vars (gimplify_ctxp->temps);
135 fprintf (stderr, " collisions: %f ",
136 htab_collisions (gimplify_ctxp->temp_htab));
139 htab_delete (gimplify_ctxp->temp_htab);
140 free (gimplify_ctxp);
141 gimplify_ctxp = NULL;
145 gimple_push_bind_expr (tree bind)
147 TREE_CHAIN (bind) = gimplify_ctxp->current_bind_expr;
148 gimplify_ctxp->current_bind_expr = bind;
152 gimple_pop_bind_expr (void)
154 gimplify_ctxp->current_bind_expr
155 = TREE_CHAIN (gimplify_ctxp->current_bind_expr);
159 gimple_current_bind_expr (void)
161 return gimplify_ctxp->current_bind_expr;
164 /* Returns true iff there is a COND_EXPR between us and the innermost
165 CLEANUP_POINT_EXPR. This info is used by gimple_push_cleanup. */
168 gimple_conditional_context (void)
170 return gimplify_ctxp->conditions > 0;
173 /* Note that we've entered a COND_EXPR. */
176 gimple_push_condition (void)
178 ++(gimplify_ctxp->conditions);
181 /* Note that we've left a COND_EXPR. If we're back at unconditional scope
182 now, add any conditional cleanups we've seen to the prequeue. */
185 gimple_pop_condition (tree *pre_p)
187 int conds = --(gimplify_ctxp->conditions);
190 append_to_statement_list (gimplify_ctxp->conditional_cleanups, pre_p);
191 gimplify_ctxp->conditional_cleanups = NULL_TREE;
197 /* A subroutine of append_to_statement_list{,_force}. */
200 append_to_statement_list_1 (tree t, tree *list_p, bool side_effects)
203 tree_stmt_iterator i;
210 if (t && TREE_CODE (t) == STATEMENT_LIST)
215 *list_p = list = alloc_stmt_list ();
219 tsi_link_after (&i, t, TSI_CONTINUE_LINKING);
222 /* Add T to the end of the list container pointed by LIST_P.
223 If T is an expression with no effects, it is ignored. */
226 append_to_statement_list (tree t, tree *list_p)
228 append_to_statement_list_1 (t, list_p, t ? TREE_SIDE_EFFECTS (t) : false);
231 /* Similar, but the statement is always added, regardless of side effects. */
234 append_to_statement_list_force (tree t, tree *list_p)
236 append_to_statement_list_1 (t, list_p, t != NULL);
239 /* Add T to the end of a COMPOUND_EXPR pointed by LIST_P. The type
240 of the result is the type of T. */
243 append_to_compound_expr (tree t, tree *list_p)
250 *list_p = build (COMPOUND_EXPR, TREE_TYPE (t), *list_p, t);
253 /* Strip off a legitimate source ending from the input string NAME of
254 length LEN. Rather than having to know the names used by all of
255 our front ends, we strip off an ending of a period followed by
256 up to five characters. (Java uses ".class".) */
259 remove_suffix (char *name, int len)
263 for (i = 2; i < 8 && len > i; i++)
265 if (name[len - i] == '.')
267 name[len - i] = '\0';
273 /* Create a nameless artificial label and put it in the current function
274 context. Returns the newly created label. */
277 create_artificial_label (void)
279 tree lab = build_decl (LABEL_DECL, NULL_TREE, void_type_node);
280 DECL_ARTIFICIAL (lab) = 1;
281 DECL_CONTEXT (lab) = current_function_decl;
285 /* Create a new temporary name with PREFIX. Returns an identifier. */
287 static GTY(()) unsigned int tmp_var_id_num;
290 create_tmp_var_name (const char *prefix)
296 char *preftmp = ASTRDUP (prefix);
297 remove_suffix (preftmp, strlen (preftmp));
301 ASM_FORMAT_PRIVATE_NAME (tmp_name, prefix ? prefix : "T", tmp_var_id_num++);
302 return get_identifier (tmp_name);
306 /* Create a new temporary variable declaration of type TYPE.
307 Does NOT push it into the current binding. */
310 create_tmp_var_raw (tree type, const char *prefix)
315 /* Make the type of the variable writable. */
316 new_type = build_type_variant (type, 0, 0);
317 TYPE_ATTRIBUTES (new_type) = TYPE_ATTRIBUTES (type);
319 tmp_var = build_decl (VAR_DECL, create_tmp_var_name (prefix), type);
321 /* The variable was declared by the compiler. */
322 DECL_ARTIFICIAL (tmp_var) = 1;
323 /* And we don't want debug info for it. */
324 DECL_IGNORED_P (tmp_var) = 1;
326 /* Make the variable writable. */
327 TREE_READONLY (tmp_var) = 0;
329 DECL_EXTERNAL (tmp_var) = 0;
330 TREE_STATIC (tmp_var) = 0;
331 TREE_USED (tmp_var) = 1;
336 /* Create a new temporary variable declaration of type TYPE. DOES push the
337 variable into the current binding. Further, assume that this is called
338 only from gimplification or optimization, at which point the creation of
339 certain types are bugs. */
342 create_tmp_var (tree type, const char *prefix)
346 #if defined ENABLE_CHECKING
347 /* If the type is an array or a type which must be created by the
348 frontend, something is wrong. */
349 if (TREE_CODE (type) == ARRAY_TYPE || TREE_ADDRESSABLE (type))
351 if (!COMPLETE_TYPE_P (type))
353 /* Variable sized types require lots of machinery to create; the
354 optimizers shouldn't be doing anything of the sort. */
355 if (TREE_CODE (TYPE_SIZE_UNIT (type)) != INTEGER_CST)
359 tmp_var = create_tmp_var_raw (type, prefix);
360 gimple_add_tmp_var (tmp_var);
364 /* Given a tree, try to return a useful variable name that we can use
365 to prefix a temporary that is being assigned the value of the tree.
366 I.E. given <temp> = &A, return A. */
374 STRIP_NOPS (stripped_decl);
375 if (DECL_P (stripped_decl) && DECL_NAME (stripped_decl))
376 return IDENTIFIER_POINTER (DECL_NAME (stripped_decl));
379 switch (TREE_CODE (stripped_decl))
382 return get_name (TREE_OPERAND (stripped_decl, 0));
390 /* Create a temporary with a name derived from VAL. Subroutine of
391 lookup_tmp_var; nobody else should call this function. */
394 create_tmp_from_val (tree val)
396 return create_tmp_var (TREE_TYPE (val), get_name (val));
399 /* Create a temporary to hold the value of VAL. If IS_FORMAL, try to reuse
400 an existing expression temporary. */
403 lookup_tmp_var (tree val, bool is_formal)
405 if (!is_formal || TREE_SIDE_EFFECTS (val))
406 return create_tmp_from_val (val);
413 slot = htab_find_slot (gimplify_ctxp->temp_htab, (void *)&elt, INSERT);
416 elt_p = xmalloc (sizeof (*elt_p));
418 elt_p->temp = create_tmp_from_val (val);
419 *slot = (void *)elt_p;
422 elt_p = (elt_t *) *slot;
428 /* Returns a formal temporary variable initialized with VAL. PRE_P is as
429 in gimplify_expr. Only use this function if:
431 1) The value of the unfactored expression represented by VAL will not
432 change between the initialization and use of the temporary, and
433 2) The temporary will not be otherwise modified.
435 For instance, #1 means that this is inappropriate for SAVE_EXPR temps,
436 and #2 means it is inappropriate for && temps.
438 For other cases, use get_initialized_tmp_var instead. */
441 internal_get_tmp_var (tree val, tree *pre_p, tree *post_p, bool is_formal)
446 gimplify_expr (&val, pre_p, post_p, is_gimple_rhs, fb_rvalue);
448 t = lookup_tmp_var (val, is_formal);
450 mod = build (MODIFY_EXPR, TREE_TYPE (t), t, val);
452 class = TREE_CODE_CLASS (TREE_CODE (val));
453 if (EXPR_LOCUS (val))
454 SET_EXPR_LOCUS (mod, EXPR_LOCUS (val));
456 annotate_with_locus (mod, input_location);
457 /* gimplify_modify_expr might want to reduce this further. */
458 gimplify_stmt (&mod);
459 append_to_statement_list (mod, pre_p);
465 get_formal_tmp_var (tree val, tree *pre_p)
467 return internal_get_tmp_var (val, pre_p, NULL, true);
470 /* Returns a temporary variable initialized with VAL. PRE_P and POST_P
471 are as in gimplify_expr. */
474 get_initialized_tmp_var (tree val, tree *pre_p, tree *post_p)
476 return internal_get_tmp_var (val, pre_p, post_p, false);
479 /* Returns true if T is a GIMPLE temporary variable, false otherwise. */
482 is_gimple_tmp_var (tree t)
484 /* FIXME this could trigger for other local artificials, too. */
485 return (TREE_CODE (t) == VAR_DECL && DECL_ARTIFICIAL (t)
486 && !TREE_STATIC (t) && !DECL_EXTERNAL (t));
489 /* Declares all the variables in VARS in SCOPE. Returns the last
490 DECL_STMT emitted. */
493 declare_tmp_vars (tree vars, tree scope)
500 /* C99 mode puts the default 'return 0;' for main() outside the outer
501 braces. So drill down until we find an actual scope. */
502 while (TREE_CODE (scope) == COMPOUND_EXPR)
503 scope = TREE_OPERAND (scope, 0);
505 if (TREE_CODE (scope) != BIND_EXPR)
508 temps = nreverse (last);
509 TREE_CHAIN (last) = BIND_EXPR_VARS (scope);
510 BIND_EXPR_VARS (scope) = temps;
512 /* We don't add the temps to the block for this BIND_EXPR, as we're
513 not interested in debugging info for them. */
518 gimple_add_tmp_var (tree tmp)
520 if (TREE_CHAIN (tmp) || tmp->decl.seen_in_bind_expr)
523 DECL_CONTEXT (tmp) = current_function_decl;
524 tmp->decl.seen_in_bind_expr = 1;
528 TREE_CHAIN (tmp) = gimplify_ctxp->temps;
529 gimplify_ctxp->temps = tmp;
534 declare_tmp_vars (tmp, DECL_SAVED_TREE (current_function_decl));
537 /* Determines whether to assign a locus to the statement STMT. */
540 should_carry_locus_p (tree stmt)
542 /* Don't emit a line note for a label. We particularly don't want to
543 emit one for the break label, since it doesn't actually correspond
544 to the beginning of the loop/switch. */
545 if (TREE_CODE (stmt) == LABEL_EXPR)
548 /* Do not annotate empty statements, since it confuses gcov. */
549 if (!TREE_SIDE_EFFECTS (stmt))
556 annotate_all_with_locus (tree *stmt_p, location_t locus)
558 tree_stmt_iterator i;
563 for (i = tsi_start (*stmt_p); !tsi_end_p (i); tsi_next (&i))
565 tree t = tsi_stmt (i);
567 #ifdef ENABLE_CHECKING
568 /* Assuming we've already been gimplified, we shouldn't
569 see nested chaining constructs anymore. */
570 if (TREE_CODE (t) == STATEMENT_LIST
571 || TREE_CODE (t) == COMPOUND_EXPR)
575 if (IS_EXPR_CODE_CLASS (TREE_CODE_CLASS (TREE_CODE (t)))
576 && ! EXPR_HAS_LOCATION (t)
577 && should_carry_locus_p (t))
578 annotate_with_locus (t, locus);
582 /* Similar to copy_tree_r() but do not copy SAVE_EXPR or TARGET_EXPR nodes.
583 These nodes model computations that should only be done once. If we
584 were to unshare something like SAVE_EXPR(i++), the gimplification
585 process would create wrong code. */
588 mostly_copy_tree_r (tree *tp, int *walk_subtrees, void *data)
590 enum tree_code code = TREE_CODE (*tp);
591 /* Don't unshare types, decls, constants and SAVE_EXPR nodes. */
592 if (TREE_CODE_CLASS (code) == 't'
593 || TREE_CODE_CLASS (code) == 'd'
594 || TREE_CODE_CLASS (code) == 'c'
595 || code == SAVE_EXPR || code == TARGET_EXPR
596 /* We can't do anything sensible with a BLOCK used as an expression,
597 but we also can't abort when we see it because of non-expression
598 uses. So just avert our eyes and cross our fingers. Silly Java. */
601 else if (code == BIND_EXPR)
604 copy_tree_r (tp, walk_subtrees, data);
609 /* Mark all the _DECL nodes under *TP as volatile. FIXME: This must die
610 after VA_ARG_EXPRs are properly lowered. */
613 mark_decls_volatile_r (tree *tp, int *walk_subtrees ATTRIBUTE_UNUSED,
614 void *data ATTRIBUTE_UNUSED)
617 TREE_THIS_VOLATILE (*tp) = 1;
623 /* Callback for walk_tree to unshare most of the shared trees rooted at
624 *TP. If *TP has been visited already (i.e., TREE_VISITED (*TP) == 1),
625 then *TP is deep copied by calling copy_tree_r.
627 This unshares the same trees as copy_tree_r with the exception of
628 SAVE_EXPR nodes. These nodes model computations that should only be
629 done once. If we were to unshare something like SAVE_EXPR(i++), the
630 gimplification process would create wrong code. */
633 copy_if_shared_r (tree *tp, int *walk_subtrees ATTRIBUTE_UNUSED,
634 void *data ATTRIBUTE_UNUSED)
637 enum tree_code code = TREE_CODE (t);
639 /* Skip types, decls, and constants. */
640 if (TREE_CODE_CLASS (code) == 't'
641 || TREE_CODE_CLASS (code) == 'd'
642 || TREE_CODE_CLASS (code) == 'c')
645 /* Special-case BIND_EXPR. We should never be copying these, therefore
646 we can omit examining BIND_EXPR_VARS. Which also avoids problems with
647 double processing of the DECL_INITIAL, which could be seen via both
648 the BIND_EXPR_VARS and a DECL_STMT. */
649 else if (code == BIND_EXPR)
651 if (TREE_VISITED (t))
653 TREE_VISITED (t) = 1;
655 walk_tree (&BIND_EXPR_BODY (t), copy_if_shared_r, NULL, NULL);
658 /* If this node has been visited already, unshare it and don't look
660 else if (TREE_VISITED (t))
662 walk_tree (tp, mostly_copy_tree_r, NULL, NULL);
666 /* Otherwise, mark the tree as visited and keep looking. */
668 TREE_VISITED (t) = 1;
674 unmark_visited_r (tree *tp, int *walk_subtrees ATTRIBUTE_UNUSED,
675 void *data ATTRIBUTE_UNUSED)
677 if (TREE_VISITED (*tp))
678 TREE_VISITED (*tp) = 0;
685 /* Unshare T and all the trees reached from T via TREE_CHAIN. */
688 unshare_all_trees (tree t)
690 walk_tree (&t, copy_if_shared_r, NULL, NULL);
691 walk_tree (&t, unmark_visited_r, NULL, NULL);
694 /* Unconditionally make an unshared copy of EXPR. This is used when using
695 stored expressions which span multiple functions, such as BINFO_VTABLE,
696 as the normal unsharing process can't tell that they're shared. */
699 unshare_expr (tree expr)
701 walk_tree (&expr, mostly_copy_tree_r, NULL, NULL);
705 /* A terser interface for building a representation of a exception
709 gimple_build_eh_filter (tree body, tree allowed, tree failure)
713 /* FIXME should the allowed types go in TREE_TYPE? */
714 t = build (EH_FILTER_EXPR, void_type_node, allowed, NULL_TREE);
715 append_to_statement_list (failure, &EH_FILTER_FAILURE (t));
717 t = build (TRY_CATCH_EXPR, void_type_node, NULL_TREE, t);
718 append_to_statement_list (body, &TREE_OPERAND (t, 0));
724 /* WRAPPER is a code such as BIND_EXPR or CLEANUP_POINT_EXPR which can both
725 contain statements and have a value. Assign its value to a temporary
726 and give it void_type_node. Returns the temporary, or NULL_TREE if
727 WRAPPER was already void. */
730 voidify_wrapper_expr (tree wrapper)
732 if (!VOID_TYPE_P (TREE_TYPE (wrapper)))
737 /* Set p to point to the body of the wrapper. */
738 switch (TREE_CODE (wrapper))
741 /* For a BIND_EXPR, the body is operand 1. */
742 p = &BIND_EXPR_BODY (wrapper);
746 p = &TREE_OPERAND (wrapper, 0);
750 /* Advance to the last statement. Set all container types to void. */
751 if (TREE_CODE (*p) == STATEMENT_LIST)
753 tree_stmt_iterator i = tsi_last (*p);
754 p = tsi_end_p (i) ? NULL : tsi_stmt_ptr (i);
758 for (; TREE_CODE (*p) == COMPOUND_EXPR; p = &TREE_OPERAND (*p, 1))
760 TREE_SIDE_EFFECTS (*p) = 1;
761 TREE_TYPE (*p) = void_type_node;
765 if (p && TREE_CODE (*p) == INIT_EXPR)
767 /* The C++ frontend already did this for us. */;
768 temp = TREE_OPERAND (*p, 0);
770 else if (p && TREE_CODE (*p) == INDIRECT_REF)
772 /* If we're returning a dereference, move the dereference outside
774 tree ptr = TREE_OPERAND (*p, 0);
775 temp = create_tmp_var (TREE_TYPE (ptr), "retval");
776 *p = build (MODIFY_EXPR, TREE_TYPE (ptr), temp, ptr);
777 temp = build1 (INDIRECT_REF, TREE_TYPE (TREE_TYPE (temp)), temp);
778 /* If this is a BIND_EXPR for a const inline function, it might not
779 have TREE_SIDE_EFFECTS set. That is no longer accurate. */
780 TREE_SIDE_EFFECTS (wrapper) = 1;
784 temp = create_tmp_var (TREE_TYPE (wrapper), "retval");
785 if (p && !IS_EMPTY_STMT (*p))
787 *p = build (MODIFY_EXPR, TREE_TYPE (temp), temp, *p);
788 TREE_SIDE_EFFECTS (wrapper) = 1;
792 TREE_TYPE (wrapper) = void_type_node;
799 /* Prepare calls to builtins to SAVE and RESTORE the stack as well as
800 a temporary through which they communicate. */
803 build_stack_save_restore (tree *save, tree *restore)
805 tree save_call, tmp_var;
808 build_function_call_expr (implicit_built_in_decls[BUILT_IN_STACK_SAVE],
810 tmp_var = create_tmp_var (ptr_type_node, "saved_stack");
812 *save = build (MODIFY_EXPR, ptr_type_node, tmp_var, save_call);
814 build_function_call_expr (implicit_built_in_decls[BUILT_IN_STACK_RESTORE],
815 tree_cons (NULL_TREE, tmp_var, NULL_TREE));
818 /* Gimplify a BIND_EXPR. Just voidify and recurse. */
820 static enum gimplify_status
821 gimplify_bind_expr (tree *expr_p, tree *pre_p)
823 tree bind_expr = *expr_p;
824 tree temp = voidify_wrapper_expr (bind_expr);
825 bool old_save_stack = gimplify_ctxp->save_stack;
828 /* Mark variables seen in this bind expr. */
829 for (t = BIND_EXPR_VARS (bind_expr); t ; t = TREE_CHAIN (t))
830 t->decl.seen_in_bind_expr = 1;
832 gimple_push_bind_expr (bind_expr);
833 gimplify_ctxp->save_stack = false;
835 gimplify_to_stmt_list (&BIND_EXPR_BODY (bind_expr));
837 if (gimplify_ctxp->save_stack)
839 tree stack_save, stack_restore;
841 /* Save stack on entry and restore it on exit. Add a try_finally
842 block to achieve this. Note that mudflap depends on the
843 format of the emitted code: see mx_register_decls(). */
844 build_stack_save_restore (&stack_save, &stack_restore);
846 t = build (TRY_FINALLY_EXPR, void_type_node,
847 BIND_EXPR_BODY (bind_expr), NULL_TREE);
848 append_to_statement_list (stack_restore, &TREE_OPERAND (t, 1));
850 BIND_EXPR_BODY (bind_expr) = NULL_TREE;
851 append_to_statement_list (stack_save, &BIND_EXPR_BODY (bind_expr));
852 append_to_statement_list (t, &BIND_EXPR_BODY (bind_expr));
855 gimplify_ctxp->save_stack = old_save_stack;
856 gimple_pop_bind_expr ();
861 append_to_statement_list (bind_expr, pre_p);
868 /* Gimplify a RETURN_EXPR. If the expression to be returned is not a
869 GIMPLE value, it is assigned to a new temporary and the statement is
870 re-written to return the temporary.
872 PRE_P points to the list where side effects that must happen before
873 STMT should be stored. */
875 static enum gimplify_status
876 gimplify_return_expr (tree stmt, tree *pre_p)
878 tree ret_expr = TREE_OPERAND (stmt, 0);
881 if (!ret_expr || TREE_CODE (ret_expr) == RESULT_DECL)
884 if (ret_expr == error_mark_node)
887 if (VOID_TYPE_P (TREE_TYPE (TREE_TYPE (current_function_decl))))
891 result = TREE_OPERAND (ret_expr, 0);
892 #ifdef ENABLE_CHECKING
893 if ((TREE_CODE (ret_expr) != MODIFY_EXPR
894 && TREE_CODE (ret_expr) != INIT_EXPR)
895 || TREE_CODE (result) != RESULT_DECL)
900 /* We need to pass the full MODIFY_EXPR down so that special handling
901 can replace it with something else. */
902 gimplify_stmt (&TREE_OPERAND (stmt, 0));
903 append_to_statement_list (TREE_OPERAND (stmt, 0), pre_p);
905 TREE_OPERAND (stmt, 0) = result;
910 /* Gimplify a LOOP_EXPR. Normally this just involves gimplifying the body
911 and replacing the LOOP_EXPR with goto, but if the loop contains an
912 EXIT_EXPR, we need to append a label for it to jump to. */
914 static enum gimplify_status
915 gimplify_loop_expr (tree *expr_p, tree *pre_p)
917 tree saved_label = gimplify_ctxp->exit_label;
918 tree start_label = build1 (LABEL_EXPR, void_type_node, NULL_TREE);
919 tree jump_stmt = build_and_jump (&LABEL_EXPR_LABEL (start_label));
921 append_to_statement_list (start_label, pre_p);
923 gimplify_ctxp->exit_label = NULL_TREE;
925 gimplify_stmt (&LOOP_EXPR_BODY (*expr_p));
926 append_to_statement_list (LOOP_EXPR_BODY (*expr_p), pre_p);
928 if (gimplify_ctxp->exit_label)
930 append_to_statement_list (jump_stmt, pre_p);
931 *expr_p = build1 (LABEL_EXPR, void_type_node, gimplify_ctxp->exit_label);
936 gimplify_ctxp->exit_label = saved_label;
941 /* Compare two case labels. Because the front end should already have
942 made sure that case ranges do not overlap, it is enough to only compare
943 the CASE_LOW values of each case label. */
946 compare_case_labels (const void *p1, const void *p2)
948 tree case1 = *(tree *)p1;
949 tree case2 = *(tree *)p2;
951 return tree_int_cst_compare (CASE_LOW (case1), CASE_LOW (case2));
954 /* Sort the case labels in LABEL_VEC in ascending order. */
957 sort_case_labels (tree label_vec)
959 size_t len = TREE_VEC_LENGTH (label_vec);
960 tree default_case = TREE_VEC_ELT (label_vec, len - 1);
962 if (CASE_LOW (default_case))
966 /* The last label in the vector should be the default case
968 for (i = 0; i < len; ++i)
970 tree t = TREE_VEC_ELT (label_vec, i);
974 TREE_VEC_ELT (label_vec, i) = TREE_VEC_ELT (label_vec, len - 1);
975 TREE_VEC_ELT (label_vec, len - 1) = default_case;
981 qsort (&TREE_VEC_ELT (label_vec, 0), len - 1, sizeof (tree),
982 compare_case_labels);
985 /* Gimplify a SWITCH_EXPR, and collect a TREE_VEC of the labels it can
988 static enum gimplify_status
989 gimplify_switch_expr (tree *expr_p, tree *pre_p)
991 tree switch_expr = *expr_p;
992 enum gimplify_status ret;
994 ret = gimplify_expr (&SWITCH_COND (switch_expr), pre_p, NULL,
995 is_gimple_val, fb_rvalue);
997 if (SWITCH_BODY (switch_expr))
999 varray_type labels, saved_labels;
1000 tree label_vec, default_case = NULL_TREE;
1003 /* If someone can be bothered to fill in the labels, they can
1004 be bothered to null out the body too. */
1005 if (SWITCH_LABELS (switch_expr))
1008 saved_labels = gimplify_ctxp->case_labels;
1009 VARRAY_TREE_INIT (gimplify_ctxp->case_labels, 8, "case_labels");
1011 gimplify_to_stmt_list (&SWITCH_BODY (switch_expr));
1013 labels = gimplify_ctxp->case_labels;
1014 gimplify_ctxp->case_labels = saved_labels;
1016 len = VARRAY_ACTIVE_SIZE (labels);
1018 for (i = 0; i < len; ++i)
1020 tree t = VARRAY_TREE (labels, i);
1023 /* The default case must be the last label in the list. */
1025 VARRAY_TREE (labels, i) = VARRAY_TREE (labels, len - 1);
1031 label_vec = make_tree_vec (len + 1);
1032 SWITCH_LABELS (*expr_p) = label_vec;
1033 append_to_statement_list (switch_expr, pre_p);
1037 /* If the switch has no default label, add one, so that we jump
1038 around the switch body. */
1039 default_case = build (CASE_LABEL_EXPR, void_type_node, NULL_TREE,
1040 NULL_TREE, create_artificial_label ());
1041 append_to_statement_list (SWITCH_BODY (switch_expr), pre_p);
1042 *expr_p = build (LABEL_EXPR, void_type_node,
1043 CASE_LABEL (default_case));
1046 *expr_p = SWITCH_BODY (switch_expr);
1048 for (i = 0; i < len; ++i)
1049 TREE_VEC_ELT (label_vec, i) = VARRAY_TREE (labels, i);
1050 TREE_VEC_ELT (label_vec, len) = default_case;
1052 sort_case_labels (label_vec);
1054 SWITCH_BODY (switch_expr) = NULL;
1056 else if (!SWITCH_LABELS (switch_expr))
1062 static enum gimplify_status
1063 gimplify_case_label_expr (tree *expr_p)
1065 tree expr = *expr_p;
1066 if (gimplify_ctxp->case_labels)
1067 VARRAY_PUSH_TREE (gimplify_ctxp->case_labels, expr);
1070 *expr_p = build (LABEL_EXPR, void_type_node, CASE_LABEL (expr));
1074 /* Gimplify a LABELED_BLOCK_EXPR into a LABEL_EXPR following
1075 a (possibly empty) body. */
1077 static enum gimplify_status
1078 gimplify_labeled_block_expr (tree *expr_p)
1080 tree body = LABELED_BLOCK_BODY (*expr_p);
1081 tree label = LABELED_BLOCK_LABEL (*expr_p);
1084 DECL_CONTEXT (label) = current_function_decl;
1085 t = build (LABEL_EXPR, void_type_node, label);
1086 if (body != NULL_TREE)
1087 t = build (COMPOUND_EXPR, void_type_node, body, t);
1093 /* Gimplify a EXIT_BLOCK_EXPR into a GOTO_EXPR. */
1095 static enum gimplify_status
1096 gimplify_exit_block_expr (tree *expr_p)
1098 tree labeled_block = TREE_OPERAND (*expr_p, 0);
1101 /* First operand must be a LABELED_BLOCK_EXPR, which should
1102 already be lowered (or partially lowered) when we get here. */
1103 #if defined ENABLE_CHECKING
1104 if (TREE_CODE (labeled_block) != LABELED_BLOCK_EXPR)
1108 label = LABELED_BLOCK_LABEL (labeled_block);
1109 *expr_p = build1 (GOTO_EXPR, void_type_node, label);
1114 /* Build a GOTO to the LABEL_DECL pointed to by LABEL_P, building it first
1118 build_and_jump (tree *label_p)
1120 if (label_p == NULL)
1121 /* If there's nowhere to jump, just fall through. */
1122 return build_empty_stmt ();
1124 if (*label_p == NULL_TREE)
1126 tree label = create_artificial_label ();
1130 return build1 (GOTO_EXPR, void_type_node, *label_p);
1133 /* Gimplify an EXIT_EXPR by converting to a GOTO_EXPR inside a COND_EXPR.
1134 This also involves building a label to jump to and communicating it to
1135 gimplify_loop_expr through gimplify_ctxp->exit_label. */
1137 static enum gimplify_status
1138 gimplify_exit_expr (tree *expr_p)
1140 tree cond = TREE_OPERAND (*expr_p, 0);
1143 expr = build_and_jump (&gimplify_ctxp->exit_label);
1144 expr = build (COND_EXPR, void_type_node, cond, expr, build_empty_stmt ());
1150 /* A helper function to be called via walk_tree. Mark all labels under *TP
1151 as being forced. To be called for DECL_INITIAL of static variables. */
1154 force_labels_r (tree *tp, int *walk_subtrees, void *data ATTRIBUTE_UNUSED)
1158 if (TREE_CODE (*tp) == LABEL_DECL)
1159 FORCED_LABEL (*tp) = 1;
1164 /* Break out elements of a constructor used as an initializer into separate
1167 Note that we still need to clear any elements that don't have explicit
1168 initializers, so if not all elements are initialized we keep the
1169 original MODIFY_EXPR, we just remove all of the constructor elements. */
1171 static enum gimplify_status
1172 gimplify_init_constructor (tree *expr_p, tree *pre_p,
1173 tree *post_p, int want_value)
1175 tree object = TREE_OPERAND (*expr_p, 0);
1176 tree ctor = TREE_OPERAND (*expr_p, 1);
1177 tree type = TREE_TYPE (ctor);
1178 enum gimplify_status ret;
1181 if (TREE_CODE (ctor) != CONSTRUCTOR)
1182 return GS_UNHANDLED;
1184 elt_list = CONSTRUCTOR_ELTS (ctor);
1187 switch (TREE_CODE (type))
1191 case QUAL_UNION_TYPE:
1194 HOST_WIDE_INT i, num_elements, num_nonzero_elements;
1195 HOST_WIDE_INT num_nonconstant_elements;
1198 /* Aggregate types must lower constructors to initialization of
1199 individual elements. The exception is that a CONSTRUCTOR node
1200 with no elements indicates zero-initialization of the whole. */
1201 if (elt_list == NULL)
1212 categorize_ctor_elements (ctor, &num_nonzero_elements,
1213 &num_nonconstant_elements);
1214 num_elements = count_type_elements (TREE_TYPE (ctor));
1216 /* If a const aggregate variable is being initialized, then it
1217 should never be a lose to promote the variable to be static. */
1218 if (num_nonconstant_elements == 0
1219 && TREE_READONLY (object)
1220 && TREE_CODE (object) == VAR_DECL)
1222 DECL_INITIAL (object) = ctor;
1223 TREE_STATIC (object) = 1;
1224 if (!DECL_NAME (object))
1225 DECL_NAME (object) = create_tmp_var_name ("C");
1226 walk_tree (&DECL_INITIAL (object), force_labels_r, NULL, NULL);
1228 /* ??? C++ doesn't automatically append a .<number> to the
1229 assembler name, and even when it does, it looks a FE private
1230 data structures to figure out what that number should be,
1231 which are not set for this variable. I suppose this is
1232 important for local statics for inline functions, which aren't
1233 "local" in the object file sense. So in order to get a unique
1234 TU-local symbol, we must invoke the lhd version now. */
1235 lhd_set_decl_assembler_name (object);
1237 *expr_p = build_empty_stmt ();
1241 /* If there are "lots" of initialized elements, and all of them
1242 are valid address constants, then the entire initializer can
1243 be dropped to memory, and then memcpy'd out. */
1244 if (num_nonconstant_elements == 0)
1246 HOST_WIDE_INT size = int_size_in_bytes (type);
1249 /* ??? We can still get unbounded array types, at least
1250 from the C++ front end. This seems wrong, but attempt
1251 to work around it for now. */
1254 size = int_size_in_bytes (TREE_TYPE (object));
1256 TREE_TYPE (ctor) = type = TREE_TYPE (object);
1259 /* Find the maximum alignment we can assume for the object. */
1260 /* ??? Make use of DECL_OFFSET_ALIGN. */
1261 if (DECL_P (object))
1262 align = DECL_ALIGN (object);
1264 align = TYPE_ALIGN (type);
1266 if (size > 0 && !can_move_by_pieces (size, align))
1268 tree new = create_tmp_var_raw (type, "C");
1269 gimple_add_tmp_var (new);
1270 TREE_STATIC (new) = 1;
1271 TREE_READONLY (new) = 1;
1272 DECL_INITIAL (new) = ctor;
1273 if (align > DECL_ALIGN (new))
1275 DECL_ALIGN (new) = align;
1276 DECL_USER_ALIGN (new) = 1;
1278 walk_tree (&DECL_INITIAL (new), force_labels_r, NULL, NULL);
1280 TREE_OPERAND (*expr_p, 1) = new;
1285 /* If there are "lots" of initialized elements, even discounting
1286 those that are not address constants (and thus *must* be
1287 computed at runtime), then partition the constructor into
1288 constant and non-constant parts. Block copy the constant
1289 parts in, then generate code for the non-constant parts. */
1290 /* TODO. There's code in cp/typeck.c to do this. */
1292 /* If there are "lots" of zeros, then block clear the object first. */
1294 if (num_elements - num_nonzero_elements > CLEAR_RATIO
1295 && num_nonzero_elements < num_elements/4)
1298 /* ??? This bit ought not be needed. For any element not present
1299 in the initializer, we should simply set them to zero. Except
1300 we'd need to *find* the elements that are not present, and that
1301 requires trickery to avoid quadratic compile-time behavior in
1302 large cases or excessive memory use in small cases. */
1305 HOST_WIDE_INT len = list_length (elt_list);
1306 if (TREE_CODE (type) == ARRAY_TYPE)
1308 tree nelts = array_type_nelts (type);
1309 if (!host_integerp (nelts, 1)
1310 || tree_low_cst (nelts, 1) != len)
1313 else if (len != fields_length (type))
1319 CONSTRUCTOR_ELTS (ctor) = NULL_TREE;
1320 append_to_statement_list (*expr_p, pre_p);
1323 for (i = 0; elt_list; i++, elt_list = TREE_CHAIN (elt_list))
1325 tree purpose, value, cref, init;
1327 purpose = TREE_PURPOSE (elt_list);
1328 value = TREE_VALUE (elt_list);
1330 if (cleared && initializer_zerop (value))
1333 if (TREE_CODE (type) == ARRAY_TYPE)
1335 tree t = TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (object)));
1337 /* ??? Here's to hoping the front end fills in all of the
1338 indicies, so we don't have to figure out what's missing
1342 /* ??? Need to handle this. */
1343 if (TREE_CODE (purpose) == RANGE_EXPR)
1346 cref = build (ARRAY_REF, t, object, purpose);
1350 cref = build (COMPONENT_REF, TREE_TYPE (purpose),
1354 init = build (MODIFY_EXPR, TREE_TYPE (purpose), cref, value);
1355 /* Each member initialization is a full-expression. */
1356 gimplify_stmt (&init);
1357 append_to_statement_list (init, pre_p);
1360 *expr_p = build_empty_stmt ();
1368 /* Extract the real and imaginary parts out of the ctor. */
1372 r = TREE_VALUE (elt_list);
1373 elt_list = TREE_CHAIN (elt_list);
1376 i = TREE_VALUE (elt_list);
1377 if (TREE_CHAIN (elt_list))
1381 if (r == NULL || i == NULL)
1383 tree zero = convert (TREE_TYPE (type), integer_zero_node);
1390 /* Complex types have either COMPLEX_CST or COMPLEX_EXPR to
1391 represent creation of a complex value. */
1392 if (TREE_CONSTANT (r) && TREE_CONSTANT (i))
1394 ctor = build_complex (type, r, i);
1395 TREE_OPERAND (*expr_p, 1) = ctor;
1399 ctor = build (COMPLEX_EXPR, type, r, i);
1400 TREE_OPERAND (*expr_p, 1) = ctor;
1401 ret = gimplify_expr (&TREE_OPERAND (*expr_p, 1), pre_p, post_p,
1402 is_gimple_rhs, fb_rvalue);
1408 /* Go ahead and simplify constant constructors to VECTOR_CST. */
1409 if (TREE_CONSTANT (ctor))
1410 TREE_OPERAND (*expr_p, 1) = build_vector (type, elt_list);
1413 /* Vector types use CONSTRUCTOR all the way through gimple
1414 compilation as a general initializer. */
1415 for (; elt_list; elt_list = TREE_CHAIN (elt_list))
1417 enum gimplify_status tret;
1418 tret = gimplify_expr (&TREE_VALUE (elt_list), pre_p, post_p,
1419 is_gimple_constructor_elt, fb_rvalue);
1420 if (tret == GS_ERROR)
1427 /* So how did we get a CONSTRUCTOR for a scalar type? */
1431 if (ret == GS_ERROR)
1433 else if (want_value)
1435 append_to_statement_list (*expr_p, pre_p);
1443 /* *EXPR_P is a COMPONENT_REF being used as an rvalue. If its type is
1444 different from its canonical type, wrap the whole thing inside a
1445 NOP_EXPR and force the type of the COMPONENT_REF to be the canonical
1448 The canonical type of a COMPONENT_REF is the type of the field being
1449 referenced--unless the field is a bit-field which can be read directly
1450 in a smaller mode, in which case the canonical type is the
1451 sign-appropriate type corresponding to that mode. */
1454 canonicalize_component_ref (tree *expr_p)
1456 tree expr = *expr_p;
1459 if (TREE_CODE (expr) != COMPONENT_REF)
1462 if (INTEGRAL_TYPE_P (TREE_TYPE (expr)))
1463 type = TREE_TYPE (get_unwidened (expr, NULL_TREE));
1465 type = TREE_TYPE (TREE_OPERAND (expr, 1));
1467 if (TREE_TYPE (expr) != type)
1469 tree old_type = TREE_TYPE (expr);
1471 /* Set the type of the COMPONENT_REF to the underlying type. */
1472 TREE_TYPE (expr) = type;
1474 /* And wrap the whole thing inside a NOP_EXPR. */
1475 expr = build1 (NOP_EXPR, old_type, expr);
1481 /* If a NOP conversion is changing a pointer to array of foo to a pointer
1482 to foo, embed that change in the ADDR_EXPR. Lest we perturb the type
1483 system too badly, we must take extra steps to ensure that the ADDR_EXPR
1484 and the addressed object continue to agree on types. */
1485 /* ??? We might could do better if we recognize
1493 canonicalize_addr_expr (tree* expr_p)
1495 tree expr = *expr_p;
1496 tree ctype = TREE_TYPE (expr);
1497 tree addr_expr = TREE_OPERAND (expr, 0);
1498 tree atype = TREE_TYPE (addr_expr);
1499 tree dctype, datype, ddatype, otype, obj_expr;
1501 /* Both cast and addr_expr types should be pointers. */
1502 if (!POINTER_TYPE_P (ctype) || !POINTER_TYPE_P (atype))
1505 /* The addr_expr type should be a pointer to an array. */
1506 datype = TREE_TYPE (atype);
1507 if (TREE_CODE (datype) != ARRAY_TYPE)
1510 /* Both cast and addr_expr types should address the same object type. */
1511 dctype = TREE_TYPE (ctype);
1512 ddatype = TREE_TYPE (datype);
1513 if (!lang_hooks.types_compatible_p (ddatype, dctype))
1516 /* The addr_expr and the object type should match. */
1517 obj_expr = TREE_OPERAND (addr_expr, 0);
1518 otype = TREE_TYPE (obj_expr);
1519 if (!lang_hooks.types_compatible_p (otype, datype))
1522 /* All checks succeeded. Build a new node to merge the cast. */
1523 *expr_p = build1 (ADDR_EXPR, ctype, obj_expr);
1526 /* *EXPR_P is a NOP_EXPR or CONVERT_EXPR. Remove it and/or other conversions
1527 underneath as appropriate. */
1529 static enum gimplify_status
1530 gimplify_conversion (tree *expr_p)
1532 /* Strip away as many useless type conversions as possible
1534 STRIP_USELESS_TYPE_CONVERSION (*expr_p);
1536 /* If we still have a conversion at the toplevel, then strip
1537 away all but the outermost conversion. */
1538 if (TREE_CODE (*expr_p) == NOP_EXPR || TREE_CODE (*expr_p) == CONVERT_EXPR)
1540 STRIP_SIGN_NOPS (TREE_OPERAND (*expr_p, 0));
1542 /* And remove the outermost conversion if it's useless. */
1543 if (tree_ssa_useless_type_conversion (*expr_p))
1544 *expr_p = TREE_OPERAND (*expr_p, 0);
1547 /* If we still have a conversion at the toplevel,
1548 then canonicalize some constructs. */
1549 if (TREE_CODE (*expr_p) == NOP_EXPR || TREE_CODE (*expr_p) == CONVERT_EXPR)
1551 tree sub = TREE_OPERAND (*expr_p, 0);
1553 /* If a NOP conversion is changing the type of a COMPONENT_REF
1554 expression, then canonicalize its type now in order to expose more
1555 redundant conversions. */
1556 if (TREE_CODE (sub) == COMPONENT_REF)
1557 canonicalize_component_ref (&TREE_OPERAND (*expr_p, 0));
1559 /* If a NOP conversion is changing a pointer to array of foo
1560 to a pointer to foo, embed that change in the ADDR_EXPR. */
1561 else if (TREE_CODE (sub) == ADDR_EXPR)
1562 canonicalize_addr_expr (expr_p);
1568 /* Reduce MIN/MAX_EXPR to a COND_EXPR for further gimplification. */
1570 static enum gimplify_status
1571 gimplify_minimax_expr (tree *expr_p, tree *pre_p, tree *post_p)
1573 tree op1 = TREE_OPERAND (*expr_p, 0);
1574 tree op2 = TREE_OPERAND (*expr_p, 1);
1575 enum tree_code code;
1576 enum gimplify_status r0, r1;
1578 if (TREE_CODE (*expr_p) == MIN_EXPR)
1583 r0 = gimplify_expr (&op1, pre_p, post_p, is_gimple_val, fb_rvalue);
1584 r1 = gimplify_expr (&op2, pre_p, post_p, is_gimple_val, fb_rvalue);
1586 *expr_p = build (COND_EXPR, TREE_TYPE (*expr_p),
1587 build (code, boolean_type_node, op1, op2),
1590 if (r0 == GS_ERROR || r1 == GS_ERROR)
1596 /* Build an expression for the address of T. Folds away INDIRECT_REF to
1597 avoid confusing the gimplify process. */
1600 build_addr_expr_with_type (tree t, tree ptrtype)
1602 if (TREE_CODE (t) == INDIRECT_REF)
1604 t = TREE_OPERAND (t, 0);
1605 if (TREE_TYPE (t) != ptrtype)
1606 t = build1 (NOP_EXPR, ptrtype, t);
1611 while (TREE_CODE (base) == COMPONENT_REF
1612 || TREE_CODE (base) == ARRAY_REF)
1613 base = TREE_OPERAND (base, 0);
1615 TREE_ADDRESSABLE (base) = 1;
1617 t = build1 (ADDR_EXPR, ptrtype, t);
1624 build_addr_expr (tree t)
1626 return build_addr_expr_with_type (t, build_pointer_type (TREE_TYPE (t)));
1629 /* Subroutine of gimplify_compound_lval and gimplify_array_ref.
1630 Converts an ARRAY_REF to the equivalent *(&array + offset) form. */
1632 static enum gimplify_status
1633 gimplify_array_ref_to_plus (tree *expr_p, tree *pre_p, tree *post_p)
1635 tree array = TREE_OPERAND (*expr_p, 0);
1636 tree arrtype = TREE_TYPE (array);
1637 tree elttype = TREE_TYPE (arrtype);
1638 tree size = size_in_bytes (elttype);
1639 tree ptrtype = build_pointer_type (elttype);
1640 enum tree_code add_code = PLUS_EXPR;
1641 tree idx = TREE_OPERAND (*expr_p, 1);
1642 tree minidx, offset, addr, result;
1643 enum gimplify_status ret;
1645 /* If the array domain does not start at zero, apply the offset. */
1646 minidx = TYPE_DOMAIN (arrtype);
1649 minidx = TYPE_MIN_VALUE (minidx);
1650 if (minidx && !integer_zerop (minidx))
1652 idx = convert (TREE_TYPE (minidx), idx);
1653 idx = fold (build (MINUS_EXPR, TREE_TYPE (minidx), idx, minidx));
1657 /* If the index is negative -- a technically invalid situation now
1658 that we've biased the index back to zero -- then casting it to
1659 unsigned has ill effects. In particular, -1*4U/4U != -1.
1660 Represent this as a subtraction of a positive rather than addition
1661 of a negative. This will prevent any conversion back to ARRAY_REF
1662 from getting the wrong results from the division. */
1663 if (TREE_CODE (idx) == INTEGER_CST && tree_int_cst_sgn (idx) < 0)
1665 idx = fold (build1 (NEGATE_EXPR, TREE_TYPE (idx), idx));
1666 add_code = MINUS_EXPR;
1669 /* Pointer arithmetic must be done in sizetype. */
1670 idx = convert (sizetype, idx);
1672 /* Convert the index to a byte offset. */
1673 offset = size_binop (MULT_EXPR, size, idx);
1675 ret = gimplify_expr (&array, pre_p, post_p, is_gimple_min_lval, fb_lvalue);
1676 if (ret == GS_ERROR)
1679 addr = build_addr_expr_with_type (array, ptrtype);
1680 result = fold (build (add_code, ptrtype, addr, offset));
1681 *expr_p = build1 (INDIRECT_REF, elttype, result);
1686 /* Gimplify the COMPONENT_REF, ARRAY_REF, REALPART_EXPR or IMAGPART_EXPR
1687 node pointed by EXPR_P.
1690 : min_lval '[' val ']'
1692 | compound_lval '[' val ']'
1693 | compound_lval '.' ID
1695 This is not part of the original SIMPLE definition, which separates
1696 array and member references, but it seems reasonable to handle them
1697 together. Also, this way we don't run into problems with union
1698 aliasing; gcc requires that for accesses through a union to alias, the
1699 union reference must be explicit, which was not always the case when we
1700 were splitting up array and member refs.
1702 PRE_P points to the list where side effects that must happen before
1703 *EXPR_P should be stored.
1705 POST_P points to the list where side effects that must happen after
1706 *EXPR_P should be stored. */
1708 static enum gimplify_status
1709 gimplify_compound_lval (tree *expr_p, tree *pre_p,
1710 tree *post_p, int want_lvalue)
1713 enum tree_code code;
1715 enum gimplify_status ret;
1717 #if defined ENABLE_CHECKING
1718 if (TREE_CODE (*expr_p) != ARRAY_REF
1719 && TREE_CODE (*expr_p) != COMPONENT_REF
1720 && TREE_CODE (*expr_p) != REALPART_EXPR
1721 && TREE_CODE (*expr_p) != IMAGPART_EXPR)
1725 code = ERROR_MARK; /* [GIMPLE] Avoid uninitialized use warning. */
1727 /* Create a stack of the subexpressions so later we can walk them in
1728 order from inner to outer. */
1729 VARRAY_TREE_INIT (stack, 10, "stack");
1732 TREE_CODE (*p) == ARRAY_REF
1733 || TREE_CODE (*p) == COMPONENT_REF
1734 || TREE_CODE (*p) == REALPART_EXPR
1735 || TREE_CODE (*p) == IMAGPART_EXPR;
1736 p = &TREE_OPERAND (*p, 0))
1738 code = TREE_CODE (*p);
1739 if (code == ARRAY_REF)
1741 tree elttype = TREE_TYPE (TREE_TYPE (TREE_OPERAND (*p, 0)));
1742 if (!TREE_CONSTANT (TYPE_SIZE_UNIT (elttype)))
1743 /* If the size of the array elements is not constant,
1744 computing the offset is non-trivial, so expose it. */
1747 VARRAY_PUSH_TREE (stack, *p);
1750 /* Now 'p' points to the first bit that isn't a ref, 'code' is the
1751 TREE_CODE of the last bit that was, and 'stack' is a stack of pointers
1752 to all the refs we've walked through.
1754 Gimplify the base, and then process each of the outer nodes from left
1756 ret = gimplify_expr (p, pre_p, post_p, is_gimple_min_lval,
1757 code != ARRAY_REF ? fb_either : fb_lvalue);
1759 for (; VARRAY_ACTIVE_SIZE (stack) > 0; )
1761 tree t = VARRAY_TOP_TREE (stack);
1762 if (TREE_CODE (t) == ARRAY_REF)
1764 /* Gimplify the dimension. */
1765 enum gimplify_status tret;
1766 /* Temporary fix for gcc.c-torture/execute/20040313-1.c.
1767 Gimplify non-constant array indices into a temporary
1769 FIXME - The real fix is to gimplify post-modify
1770 expressions into a minimal gimple lvalue. However, that
1771 exposes bugs in alias analysis. The alias analyzer does
1772 not handle &PTR->FIELD very well. Will fix after the
1773 branch is merged into mainline (dnovillo 2004-05-03). */
1774 if (!is_gimple_min_invariant (TREE_OPERAND (t, 1)))
1776 tret = gimplify_expr (&TREE_OPERAND (t, 1), pre_p, post_p,
1777 is_gimple_tmp_var, fb_rvalue);
1778 if (tret == GS_ERROR)
1782 recalculate_side_effects (t);
1786 /* If the outermost expression is a COMPONENT_REF, canonicalize its type. */
1787 if (!want_lvalue && TREE_CODE (*expr_p) == COMPONENT_REF)
1789 canonicalize_component_ref (expr_p);
1790 ret = MIN (ret, GS_OK);
1796 /* Re-write the ARRAY_REF node pointed by EXPR_P.
1798 PRE_P points to the list where side effects that must happen before
1799 *EXPR_P should be stored.
1801 POST_P points to the list where side effects that must happen after
1802 *EXPR_P should be stored.
1804 FIXME: ARRAY_REF currently doesn't accept a pointer as the array
1805 argument, so this gimplification uses an INDIRECT_REF of ARRAY_TYPE.
1806 ARRAY_REF should be extended. */
1808 static enum gimplify_status
1809 gimplify_array_ref (tree *expr_p, tree *pre_p,
1810 tree *post_p, int want_lvalue)
1812 tree elttype = TREE_TYPE (TREE_TYPE (TREE_OPERAND (*expr_p, 0)));
1813 if (!TREE_CONSTANT (TYPE_SIZE_UNIT (elttype)))
1814 /* If the size of the array elements is not constant,
1815 computing the offset is non-trivial, so expose it. */
1816 return gimplify_array_ref_to_plus (expr_p, pre_p, post_p);
1818 /* Handle array and member refs together for now. When alias analysis
1819 improves, we may want to go back to handling them separately. */
1820 return gimplify_compound_lval (expr_p, pre_p, post_p, want_lvalue);
1823 /* Gimplify the self modifying expression pointed by EXPR_P (++, --, +=, -=).
1825 PRE_P points to the list where side effects that must happen before
1826 *EXPR_P should be stored.
1828 POST_P points to the list where side effects that must happen after
1829 *EXPR_P should be stored.
1831 WANT_VALUE is nonzero iff we want to use the value of this expression
1832 in another expression. */
1834 static enum gimplify_status
1835 gimplify_self_mod_expr (tree *expr_p, tree *pre_p, tree *post_p,
1838 enum tree_code code;
1839 tree lhs, lvalue, rhs, t1;
1841 enum tree_code arith_code;
1842 enum gimplify_status ret;
1844 code = TREE_CODE (*expr_p);
1846 #if defined ENABLE_CHECKING
1847 if (code != POSTINCREMENT_EXPR
1848 && code != POSTDECREMENT_EXPR
1849 && code != PREINCREMENT_EXPR
1850 && code != PREDECREMENT_EXPR)
1854 /* Prefix or postfix? */
1855 if (code == POSTINCREMENT_EXPR || code == POSTDECREMENT_EXPR)
1856 /* Faster to treat as prefix if result is not used. */
1857 postfix = want_value;
1861 /* Add or subtract? */
1862 if (code == PREINCREMENT_EXPR || code == POSTINCREMENT_EXPR)
1863 arith_code = PLUS_EXPR;
1865 arith_code = MINUS_EXPR;
1867 /* Gimplify the LHS into a GIMPLE lvalue. */
1868 lvalue = TREE_OPERAND (*expr_p, 0);
1869 ret = gimplify_expr (&lvalue, pre_p, post_p, is_gimple_lvalue, fb_lvalue);
1870 if (ret == GS_ERROR)
1873 /* Extract the operands to the arithmetic operation. */
1875 rhs = TREE_OPERAND (*expr_p, 1);
1877 /* For postfix operator, we evaluate the LHS to an rvalue and then use
1878 that as the result value and in the postqueue operation. */
1881 ret = gimplify_expr (&lhs, pre_p, post_p, is_gimple_val, fb_rvalue);
1882 if (ret == GS_ERROR)
1886 t1 = build (arith_code, TREE_TYPE (*expr_p), lhs, rhs);
1887 t1 = build (MODIFY_EXPR, TREE_TYPE (lvalue), lvalue, t1);
1891 gimplify_stmt (&t1);
1892 append_to_statement_list (t1, post_p);
1903 /* Gimplify the CALL_EXPR node pointed by EXPR_P.
1906 : ID '(' arglist ')'
1912 PRE_P points to the list where side effects that must happen before
1913 *EXPR_P should be stored. */
1915 static enum gimplify_status
1916 gimplify_call_expr (tree *expr_p, tree *pre_p, bool (*gimple_test_f) (tree))
1920 enum gimplify_status ret;
1922 #if defined ENABLE_CHECKING
1923 if (TREE_CODE (*expr_p) != CALL_EXPR)
1927 /* For reliable diagnostics during inlining, it is necessary that
1928 every call_expr be annotated with file and line. */
1929 if (!EXPR_LOCUS (*expr_p))
1930 annotate_with_locus (*expr_p, input_location);
1932 /* This may be a call to a builtin function.
1934 Builtin function calls may be transformed into different
1935 (and more efficient) builtin function calls under certain
1936 circumstances. Unfortunately, gimplification can muck things
1937 up enough that the builtin expanders are not aware that certain
1938 transformations are still valid.
1940 So we attempt transformation/gimplification of the call before
1941 we gimplify the CALL_EXPR. At this time we do not manage to
1942 transform all calls in the same manner as the expanders do, but
1943 we do transform most of them. */
1944 decl = get_callee_fndecl (*expr_p);
1945 if (decl && DECL_BUILT_IN (decl))
1949 /* If it is allocation of stack, record the need to restore the memory
1950 when the enclosing bind_expr is exited. */
1951 if (DECL_FUNCTION_CODE (decl) == BUILT_IN_STACK_ALLOC)
1952 gimplify_ctxp->save_stack = true;
1954 /* If it is restore of the stack, reset it, since it means we are
1955 regimplifying the bind_expr. Note that we use the fact that
1956 for try_finally_expr, try part is processed first. */
1957 if (DECL_FUNCTION_CODE (decl) == BUILT_IN_STACK_RESTORE)
1958 gimplify_ctxp->save_stack = false;
1960 new = simplify_builtin (*expr_p, gimple_test_f == is_gimple_stmt);
1962 if (new && new != *expr_p)
1964 /* There was a transformation of this call which computes the
1965 same value, but in a more efficient way. Return and try
1972 /* There is a sequence point before the call, so any side effects in
1973 the calling expression must occur before the actual call. Force
1974 gimplify_expr to use an internal post queue. */
1975 ret = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p, NULL,
1976 is_gimple_val, fb_rvalue);
1978 if (PUSH_ARGS_REVERSED)
1979 TREE_OPERAND (*expr_p, 1) = nreverse (TREE_OPERAND (*expr_p, 1));
1980 for (arglist = TREE_OPERAND (*expr_p, 1); arglist;
1981 arglist = TREE_CHAIN (arglist))
1983 enum gimplify_status t;
1985 /* There is a sequence point before a function call. Side effects in
1986 the argument list must occur before the actual call. So, when
1987 gimplifying arguments, force gimplify_expr to use an internal
1988 post queue which is then appended to the end of PRE_P. */
1989 t = gimplify_expr (&TREE_VALUE (arglist), pre_p, NULL, is_gimple_val,
1995 if (PUSH_ARGS_REVERSED)
1996 TREE_OPERAND (*expr_p, 1) = nreverse (TREE_OPERAND (*expr_p, 1));
1998 /* Try this again in case gimplification exposed something. */
1999 if (ret != GS_ERROR && decl && DECL_BUILT_IN (decl))
2001 tree new = simplify_builtin (*expr_p, gimple_test_f == is_gimple_stmt);
2003 if (new && new != *expr_p)
2005 /* There was a transformation of this call which computes the
2006 same value, but in a more efficient way. Return and try
2013 /* If the function is "const" or "pure", then clear TREE_SIDE_EFFECTS on its
2014 decl. This allows us to eliminate redundant or useless
2015 calls to "const" functions. */
2016 if (TREE_CODE (*expr_p) == CALL_EXPR
2017 && (call_expr_flags (*expr_p) & (ECF_CONST | ECF_PURE)))
2018 TREE_SIDE_EFFECTS (*expr_p) = 0;
2023 /* Handle shortcut semantics in the predicate operand of a COND_EXPR by
2024 rewriting it into multiple COND_EXPRs, and possibly GOTO_EXPRs.
2026 TRUE_LABEL_P and FALSE_LABEL_P point to the labels to jump to if the
2027 condition is true or false, respectively. If null, we should generate
2028 our own to skip over the evaluation of this specific expression.
2030 This function is the tree equivalent of do_jump.
2032 shortcut_cond_r should only be called by shortcut_cond_expr. */
2035 shortcut_cond_r (tree pred, tree *true_label_p, tree *false_label_p)
2037 tree local_label = NULL_TREE;
2038 tree t, expr = NULL;
2040 /* OK, it's not a simple case; we need to pull apart the COND_EXPR to
2041 retain the shortcut semantics. Just insert the gotos here;
2042 shortcut_cond_expr will append the real blocks later. */
2043 if (TREE_CODE (pred) == TRUTH_ANDIF_EXPR)
2045 /* Turn if (a && b) into
2047 if (a); else goto no;
2048 if (b) goto yes; else goto no;
2051 if (false_label_p == NULL)
2052 false_label_p = &local_label;
2054 t = shortcut_cond_r (TREE_OPERAND (pred, 0), NULL, false_label_p);
2055 append_to_statement_list (t, &expr);
2057 t = shortcut_cond_r (TREE_OPERAND (pred, 1), true_label_p,
2059 append_to_statement_list (t, &expr);
2061 else if (TREE_CODE (pred) == TRUTH_ORIF_EXPR)
2063 /* Turn if (a || b) into
2066 if (b) goto yes; else goto no;
2069 if (true_label_p == NULL)
2070 true_label_p = &local_label;
2072 t = shortcut_cond_r (TREE_OPERAND (pred, 0), true_label_p, NULL);
2073 append_to_statement_list (t, &expr);
2075 t = shortcut_cond_r (TREE_OPERAND (pred, 1), true_label_p,
2077 append_to_statement_list (t, &expr);
2079 else if (TREE_CODE (pred) == COND_EXPR)
2081 /* As long as we're messing with gotos, turn if (a ? b : c) into
2083 if (b) goto yes; else goto no;
2085 if (c) goto yes; else goto no; */
2086 expr = build (COND_EXPR, void_type_node, TREE_OPERAND (pred, 0),
2087 shortcut_cond_r (TREE_OPERAND (pred, 1), true_label_p,
2089 shortcut_cond_r (TREE_OPERAND (pred, 2), true_label_p,
2094 expr = build (COND_EXPR, void_type_node, pred,
2095 build_and_jump (true_label_p),
2096 build_and_jump (false_label_p));
2101 t = build1 (LABEL_EXPR, void_type_node, local_label);
2102 append_to_statement_list (t, &expr);
2109 shortcut_cond_expr (tree expr)
2111 tree pred = TREE_OPERAND (expr, 0);
2112 tree then_ = TREE_OPERAND (expr, 1);
2113 tree else_ = TREE_OPERAND (expr, 2);
2114 tree true_label, false_label, end_label, t;
2116 tree *false_label_p;
2117 bool emit_end, emit_false;
2119 /* First do simple transformations. */
2120 if (!TREE_SIDE_EFFECTS (else_))
2122 /* If there is no 'else', turn (a && b) into if (a) if (b). */
2123 while (TREE_CODE (pred) == TRUTH_ANDIF_EXPR)
2125 TREE_OPERAND (expr, 0) = TREE_OPERAND (pred, 1);
2126 then_ = shortcut_cond_expr (expr);
2127 pred = TREE_OPERAND (pred, 0);
2128 expr = build (COND_EXPR, void_type_node, pred, then_,
2129 build_empty_stmt ());
2132 if (!TREE_SIDE_EFFECTS (then_))
2134 /* If there is no 'then', turn
2137 if (a); else if (b); else d. */
2138 while (TREE_CODE (pred) == TRUTH_ORIF_EXPR)
2140 TREE_OPERAND (expr, 0) = TREE_OPERAND (pred, 1);
2141 else_ = shortcut_cond_expr (expr);
2142 pred = TREE_OPERAND (pred, 0);
2143 expr = build (COND_EXPR, void_type_node, pred,
2144 build_empty_stmt (), else_);
2148 /* If we're done, great. */
2149 if (TREE_CODE (pred) != TRUTH_ANDIF_EXPR
2150 && TREE_CODE (pred) != TRUTH_ORIF_EXPR)
2153 /* Otherwise we need to mess with gotos. Change
2156 if (a); else goto no;
2159 and recursively gimplify the condition. */
2161 true_label = false_label = end_label = NULL_TREE;
2163 /* If our arms just jump somewhere, hijack those labels so we don't
2164 generate jumps to jumps. */
2166 if (TREE_CODE (then_) == GOTO_EXPR
2167 && TREE_CODE (GOTO_DESTINATION (then_)) == LABEL_DECL)
2169 true_label = GOTO_DESTINATION (then_);
2170 then_ = build_empty_stmt ();
2173 if (TREE_CODE (else_) == GOTO_EXPR
2174 && TREE_CODE (GOTO_DESTINATION (else_)) == LABEL_DECL)
2176 false_label = GOTO_DESTINATION (else_);
2177 else_ = build_empty_stmt ();
2180 /* If we aren't hijacking a label for the 'then' branch, it falls through. */
2182 true_label_p = &true_label;
2184 true_label_p = NULL;
2186 /* The 'else' branch also needs a label if it contains interesting code. */
2187 if (false_label || TREE_SIDE_EFFECTS (else_))
2188 false_label_p = &false_label;
2190 false_label_p = NULL;
2192 /* If there was nothing else in our arms, just forward the label(s). */
2193 if (!TREE_SIDE_EFFECTS (then_) && !TREE_SIDE_EFFECTS (else_))
2194 return shortcut_cond_r (pred, true_label_p, false_label_p);
2196 /* If our last subexpression already has a terminal label, reuse it. */
2197 if (TREE_SIDE_EFFECTS (else_))
2198 expr = expr_last (else_);
2200 expr = expr_last (then_);
2201 if (TREE_CODE (expr) == LABEL_EXPR)
2202 end_label = LABEL_EXPR_LABEL (expr);
2204 /* If we don't care about jumping to the 'else' branch, jump to the end
2205 if the condition is false. */
2207 false_label_p = &end_label;
2209 /* We only want to emit these labels if we aren't hijacking them. */
2210 emit_end = (end_label == NULL_TREE);
2211 emit_false = (false_label == NULL_TREE);
2213 pred = shortcut_cond_r (pred, true_label_p, false_label_p);
2216 append_to_statement_list (pred, &expr);
2218 append_to_statement_list (then_, &expr);
2219 if (TREE_SIDE_EFFECTS (else_))
2221 t = build_and_jump (&end_label);
2222 append_to_statement_list (t, &expr);
2225 t = build1 (LABEL_EXPR, void_type_node, false_label);
2226 append_to_statement_list (t, &expr);
2228 append_to_statement_list (else_, &expr);
2230 if (emit_end && end_label)
2232 t = build1 (LABEL_EXPR, void_type_node, end_label);
2233 append_to_statement_list (t, &expr);
2239 /* EXPR is used in a boolean context; make sure it has BOOLEAN_TYPE. */
2242 gimple_boolify (tree expr)
2244 tree type = TREE_TYPE (expr);
2246 if (TREE_CODE (type) == BOOLEAN_TYPE)
2249 /* If this is the predicate of a COND_EXPR, it might not even be a
2251 expr = lang_hooks.truthvalue_conversion (expr);
2253 switch (TREE_CODE (expr))
2255 case TRUTH_AND_EXPR:
2257 case TRUTH_XOR_EXPR:
2258 case TRUTH_ANDIF_EXPR:
2259 case TRUTH_ORIF_EXPR:
2260 /* Also boolify the arguments of truth exprs. */
2261 TREE_OPERAND (expr, 1) = gimple_boolify (TREE_OPERAND (expr, 1));
2264 case TRUTH_NOT_EXPR:
2265 TREE_OPERAND (expr, 0) = gimple_boolify (TREE_OPERAND (expr, 0));
2268 case EQ_EXPR: case NE_EXPR:
2269 case LE_EXPR: case GE_EXPR: case LT_EXPR: case GT_EXPR:
2270 /* These expressions always produce boolean results. */
2271 TREE_TYPE (expr) = boolean_type_node;
2275 /* Other expressions that get here must have boolean values, but
2276 might need to be converted to the appropriate mode. */
2277 return convert (boolean_type_node, expr);
2281 /* Convert the conditional expression pointed by EXPR_P '(p) ? a : b;'
2290 The second form is used when *EXPR_P is of type void.
2292 PRE_P points to the list where side effects that must happen before
2293 *EXPR_P should be stored. */
2295 static enum gimplify_status
2296 gimplify_cond_expr (tree *expr_p, tree *pre_p, tree target)
2298 tree expr = *expr_p;
2300 enum gimplify_status ret;
2302 /* If this COND_EXPR has a value, copy the values into a temporary within
2304 if (! VOID_TYPE_P (TREE_TYPE (expr)))
2313 tmp = create_tmp_var (TREE_TYPE (expr), "iftmp");
2317 /* Build the then clause, 't1 = a;'. But don't build an assignment
2318 if this branch is void; in C++ it can be, if it's a throw. */
2319 if (TREE_TYPE (TREE_OPERAND (expr, 1)) != void_type_node)
2320 TREE_OPERAND (expr, 1)
2321 = build (MODIFY_EXPR, void_type_node, tmp, TREE_OPERAND (expr, 1));
2323 /* Build the else clause, 't1 = b;'. */
2324 if (TREE_TYPE (TREE_OPERAND (expr, 2)) != void_type_node)
2325 TREE_OPERAND (expr, 2)
2326 = build (MODIFY_EXPR, void_type_node, tmp, TREE_OPERAND (expr, 2));
2328 TREE_TYPE (expr) = void_type_node;
2329 recalculate_side_effects (expr);
2331 /* Move the COND_EXPR to the prequeue and use the temp in its place. */
2332 gimplify_stmt (&expr);
2333 append_to_statement_list (expr, pre_p);
2339 /* Make sure the condition has BOOLEAN_TYPE. */
2340 TREE_OPERAND (expr, 0) = gimple_boolify (TREE_OPERAND (expr, 0));
2342 /* Break apart && and || conditions. */
2343 if (TREE_CODE (TREE_OPERAND (expr, 0)) == TRUTH_ANDIF_EXPR
2344 || TREE_CODE (TREE_OPERAND (expr, 0)) == TRUTH_ORIF_EXPR)
2346 expr = shortcut_cond_expr (expr);
2348 if (expr != *expr_p)
2352 /* We can't rely on gimplify_expr to re-gimplify the expanded
2353 form properly, as cleanups might cause the target labels to be
2354 wrapped in a TRY_FINALLY_EXPR. To prevent that, we need to
2355 set up a conditional context. */
2356 gimple_push_condition ();
2357 gimplify_stmt (expr_p);
2358 gimple_pop_condition (pre_p);
2364 /* Now do the normal gimplification. */
2365 ret = gimplify_expr (&TREE_OPERAND (expr, 0), pre_p, NULL,
2366 is_gimple_condexpr, fb_rvalue);
2368 gimple_push_condition ();
2370 gimplify_to_stmt_list (&TREE_OPERAND (expr, 1));
2371 gimplify_to_stmt_list (&TREE_OPERAND (expr, 2));
2372 recalculate_side_effects (expr);
2374 gimple_pop_condition (pre_p);
2376 if (ret == GS_ERROR)
2378 else if (TREE_SIDE_EFFECTS (TREE_OPERAND (expr, 1)))
2380 else if (TREE_SIDE_EFFECTS (TREE_OPERAND (expr, 2)))
2381 /* Rewrite "if (a); else b" to "if (!a) b" */
2383 TREE_OPERAND (expr, 0) = invert_truthvalue (TREE_OPERAND (expr, 0));
2384 ret = gimplify_expr (&TREE_OPERAND (expr, 0), pre_p, NULL,
2385 is_gimple_condexpr, fb_rvalue);
2387 tmp = TREE_OPERAND (expr, 1);
2388 TREE_OPERAND (expr, 1) = TREE_OPERAND (expr, 2);
2389 TREE_OPERAND (expr, 2) = tmp;
2392 /* Both arms are empty; replace the COND_EXPR with its predicate. */
2393 expr = TREE_OPERAND (expr, 0);
2399 /* Gimplify the MODIFY_EXPR node pointed by EXPR_P.
2405 PRE_P points to the list where side effects that must happen before
2406 *EXPR_P should be stored.
2408 POST_P points to the list where side effects that must happen after
2409 *EXPR_P should be stored.
2411 WANT_VALUE is nonzero iff we want to use the value of this expression
2412 in another expression. */
2414 static enum gimplify_status
2415 gimplify_modify_expr (tree *expr_p, tree *pre_p, tree *post_p, bool want_value)
2417 tree *from_p = &TREE_OPERAND (*expr_p, 1);
2418 tree *to_p = &TREE_OPERAND (*expr_p, 0);
2419 enum gimplify_status ret;
2421 #if defined ENABLE_CHECKING
2422 if (TREE_CODE (*expr_p) != MODIFY_EXPR && TREE_CODE (*expr_p) != INIT_EXPR)
2426 /* The distinction between MODIFY_EXPR and INIT_EXPR is no longer useful. */
2427 if (TREE_CODE (*expr_p) == INIT_EXPR)
2428 TREE_SET_CODE (*expr_p, MODIFY_EXPR);
2430 ret = gimplify_expr (to_p, pre_p, post_p, is_gimple_lvalue, fb_lvalue);
2431 if (ret == GS_ERROR)
2434 /* If we are initializing something from a TARGET_EXPR, strip the
2435 TARGET_EXPR and initialize it directly. */
2436 /* What about code that pulls out the temp and uses it elsewhere? I
2437 think that such code never uses the TARGET_EXPR as an initializer. If
2438 I'm wrong, we'll abort because the temp won't have any RTL. In that
2439 case, I guess we'll need to replace references somehow. */
2440 if (TREE_CODE (*from_p) == TARGET_EXPR)
2441 *from_p = TARGET_EXPR_INITIAL (*from_p);
2443 /* If we're assigning from a ?: expression with ADDRESSABLE type, push
2444 the assignment down into the branches, since we can't generate a
2445 temporary of such a type. */
2446 if (TREE_CODE (*from_p) == COND_EXPR
2447 && TREE_ADDRESSABLE (TREE_TYPE (*from_p)))
2450 return gimplify_cond_expr (expr_p, pre_p, *to_p);
2453 ret = gimplify_expr (from_p, pre_p, post_p, is_gimple_rhs, fb_rvalue);
2454 if (ret == GS_ERROR)
2457 ret = gimplify_init_constructor (expr_p, pre_p, post_p, want_value);
2458 if (ret != GS_UNHANDLED)
2461 /* If the destination is already simple, nothing else needed. */
2462 if (is_gimple_tmp_var (*to_p))
2466 /* If the RHS of the MODIFY_EXPR may throw or make a nonlocal goto and
2467 the LHS is a user variable, then we need to introduce a temporary.
2468 ie temp = RHS; LHS = temp.
2470 This way the optimizers can determine that the user variable is
2471 only modified if evaluation of the RHS does not throw.
2473 FIXME this should be handled by the is_gimple_rhs predicate. */
2475 if (TREE_CODE (*from_p) == CALL_EXPR
2476 || (flag_non_call_exceptions && tree_could_trap_p (*from_p))
2477 /* If we're dealing with a renamable type, either source or dest
2478 must be a renamed variable. */
2479 || (is_gimple_reg_type (TREE_TYPE (*from_p))
2480 && !is_gimple_reg (*to_p)))
2481 gimplify_expr (from_p, pre_p, post_p, is_gimple_val, fb_rvalue);
2483 /* If the value being copied is of variable width, expose the length
2484 if the copy by converting the whole thing to a memcpy. */
2485 /* ??? Except that we can't manage this with VA_ARG_EXPR. Yes, this
2486 does leave us with an edge condition that doesn't work. The only
2487 way out is to rearrange how VA_ARG_EXPR works. */
2488 if (TREE_CODE (TYPE_SIZE_UNIT (TREE_TYPE (*to_p))) != INTEGER_CST
2489 && TREE_CODE (*from_p) != VA_ARG_EXPR)
2493 t = TYPE_SIZE_UNIT (TREE_TYPE (*to_p));
2494 t = unshare_expr (t);
2495 args = tree_cons (NULL, t, NULL);
2496 t = build_addr_expr (*from_p);
2497 args = tree_cons (NULL, t, args);
2498 dest = build_addr_expr (*to_p);
2499 args = tree_cons (NULL, dest, args);
2500 t = implicit_built_in_decls[BUILT_IN_MEMCPY];
2501 t = build_function_call_expr (t, args);
2504 t = build1 (NOP_EXPR, TREE_TYPE (dest), t);
2505 t = build1 (INDIRECT_REF, TREE_TYPE (*to_p), t);
2512 ret = want_value ? GS_OK : GS_ALL_DONE;
2517 append_to_statement_list (*expr_p, pre_p);
2524 /* Gimplify TRUTH_ANDIF_EXPR and TRUTH_ORIF_EXPR expressions. EXPR_P
2525 points to the expression to gimplify.
2527 Expressions of the form 'a && b' are gimplified to:
2529 a && b ? true : false
2531 gimplify_cond_expr will do the rest.
2533 PRE_P points to the list where side effects that must happen before
2534 *EXPR_P should be stored. */
2536 static enum gimplify_status
2537 gimplify_boolean_expr (tree *expr_p)
2539 /* Preserve the original type of the expression. */
2540 tree type = TREE_TYPE (*expr_p);
2542 *expr_p = build (COND_EXPR, type, *expr_p,
2543 convert (type, boolean_true_node),
2544 convert (type, boolean_false_node));
2549 /* Gimplifies an expression sequence. This function gimplifies each
2550 expression and re-writes the original expression with the last
2551 expression of the sequence in GIMPLE form.
2553 PRE_P points to the list where the side effects for all the
2554 expressions in the sequence will be emitted.
2556 WANT_VALUE is true when the result of the last COMPOUND_EXPR is used. */
2557 /* ??? Should rearrange to share the pre-queue with all the indirect
2558 invocations of gimplify_expr. Would probably save on creations
2559 of statement_list nodes. */
2561 static enum gimplify_status
2562 gimplify_compound_expr (tree *expr_p, tree *pre_p, bool want_value)
2568 tree *sub_p = &TREE_OPERAND (t, 0);
2570 if (TREE_CODE (*sub_p) == COMPOUND_EXPR)
2571 gimplify_compound_expr (sub_p, pre_p, false);
2573 gimplify_stmt (sub_p);
2574 append_to_statement_list (*sub_p, pre_p);
2576 t = TREE_OPERAND (t, 1);
2578 while (TREE_CODE (t) == COMPOUND_EXPR);
2585 gimplify_stmt (expr_p);
2590 /* Gimplifies a statement list. These may be created either by an
2591 enlightened front-end, or by shortcut_cond_expr. */
2593 static enum gimplify_status
2594 gimplify_statement_list (tree *expr_p)
2596 tree_stmt_iterator i = tsi_start (*expr_p);
2598 while (!tsi_end_p (i))
2602 gimplify_stmt (tsi_stmt_ptr (i));
2605 if (TREE_CODE (t) == STATEMENT_LIST)
2607 tsi_link_before (&i, t, TSI_SAME_STMT);
2617 /* Gimplify a SAVE_EXPR node. EXPR_P points to the expression to
2618 gimplify. After gimplification, EXPR_P will point to a new temporary
2619 that holds the original value of the SAVE_EXPR node.
2621 PRE_P points to the list where side effects that must happen before
2622 *EXPR_P should be stored. */
2624 static enum gimplify_status
2625 gimplify_save_expr (tree *expr_p, tree *pre_p, tree *post_p)
2627 enum gimplify_status ret = GS_ALL_DONE;
2630 #if defined ENABLE_CHECKING
2631 if (TREE_CODE (*expr_p) != SAVE_EXPR)
2635 val = TREE_OPERAND (*expr_p, 0);
2637 /* If the operand is already a GIMPLE temporary, just re-write the
2639 if (is_gimple_tmp_var (val))
2641 /* The operand may be a void-valued expression such as SAVE_EXPRs
2642 generated by the Java frontend for class initialization. It is
2643 being executed only for its side-effects. */
2644 else if (TREE_TYPE (val) == void_type_node)
2646 tree body = TREE_OPERAND (*expr_p, 0);
2647 ret = gimplify_expr (& body, pre_p, post_p, is_gimple_stmt, fb_none);
2648 append_to_statement_list (body, pre_p);
2649 *expr_p = build_empty_stmt ();
2652 *expr_p = TREE_OPERAND (*expr_p, 0)
2653 = get_initialized_tmp_var (val, pre_p, post_p);
2658 /* Re-write the ADDR_EXPR node pointed by EXPR_P
2665 PRE_P points to the list where side effects that must happen before
2666 *EXPR_P should be stored.
2668 POST_P points to the list where side effects that must happen after
2669 *EXPR_P should be stored. */
2671 static enum gimplify_status
2672 gimplify_addr_expr (tree *expr_p, tree *pre_p, tree *post_p)
2674 tree expr = *expr_p;
2675 tree op0 = TREE_OPERAND (expr, 0);
2676 enum gimplify_status ret;
2678 switch (TREE_CODE (op0))
2681 /* Check if we are dealing with an expression of the form '&*ptr'.
2682 While the front end folds away '&*ptr' into 'ptr', these
2683 expressions may be generated internally by the compiler (e.g.,
2684 builtins like __builtin_va_end). */
2685 *expr_p = TREE_OPERAND (op0, 0);
2690 /* Fold &a[6] to (&a + 6). */
2691 ret = gimplify_array_ref_to_plus (&TREE_OPERAND (expr, 0),
2694 /* This added an INDIRECT_REF. Fold it away. */
2695 op0 = TREE_OPERAND (TREE_OPERAND (expr, 0), 0);
2701 /* We use fb_either here because the C frontend sometimes takes
2702 the address of a call that returns a struct. */
2703 ret = gimplify_expr (&TREE_OPERAND (expr, 0), pre_p, post_p,
2704 is_gimple_addr_expr_arg, fb_either);
2705 if (ret != GS_ERROR)
2707 /* At this point, the argument of the ADDR_EXPR should be
2708 sufficiently simple that there are never side effects. */
2709 /* ??? Could split out the decision code from build1 to verify. */
2710 TREE_SIDE_EFFECTS (expr) = 0;
2712 /* Make sure TREE_INVARIANT/TREE_CONSTANT is set properly. */
2713 recompute_tree_invarant_for_addr_expr (expr);
2715 /* Mark the RHS addressable. */
2716 lang_hooks.mark_addressable (TREE_OPERAND (expr, 0));
2721 /* If the operand is gimplified into a _DECL, mark the address expression
2722 as TREE_INVARIANT. */
2723 if (DECL_P (TREE_OPERAND (expr, 0)))
2724 TREE_INVARIANT (expr) = 1;
2729 /* Gimplify the operands of an ASM_EXPR. Input operands should be a gimple
2730 value; output operands should be a gimple lvalue. */
2732 static enum gimplify_status
2733 gimplify_asm_expr (tree *expr_p, tree *pre_p, tree *post_p)
2735 tree expr = *expr_p;
2736 int noutputs = list_length (ASM_OUTPUTS (expr));
2737 const char **oconstraints
2738 = (const char **) alloca ((noutputs) * sizeof (const char *));
2741 const char *constraint;
2742 bool allows_mem, allows_reg, is_inout;
2743 enum gimplify_status ret, tret;
2746 = resolve_asm_operand_names (ASM_STRING (expr), ASM_OUTPUTS (expr),
2750 for (i = 0, link = ASM_OUTPUTS (expr); link; ++i, link = TREE_CHAIN (link))
2752 oconstraints[i] = constraint
2753 = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (link)));
2755 parse_output_constraint (&constraint, i, 0, 0,
2756 &allows_mem, &allows_reg, &is_inout);
2758 if (!allows_reg && allows_mem)
2759 lang_hooks.mark_addressable (TREE_VALUE (link));
2761 tret = gimplify_expr (&TREE_VALUE (link), pre_p, post_p,
2762 is_inout ? is_gimple_min_lval : is_gimple_lvalue,
2763 fb_lvalue | fb_mayfail);
2764 if (tret == GS_ERROR)
2766 error ("invalid lvalue in asm output %d", i);
2772 /* An input/output operand. To give the optimizers more
2773 flexibility, split it into separate input and output
2777 size_t constraint_len = strlen (constraint);
2779 /* Turn the in/out constraint into an output constraint. */
2780 char *p = xstrdup (constraint);
2782 TREE_VALUE (TREE_PURPOSE (link)) = build_string (constraint_len, p);
2785 /* And add a matching input constraint. */
2788 sprintf (buf, "%d", i);
2789 input = build_string (strlen (buf), buf);
2792 input = build_string (constraint_len - 1, constraint + 1);
2793 input = build_tree_list (build_tree_list (NULL_TREE, input),
2794 unshare_expr (TREE_VALUE (link)));
2795 ASM_INPUTS (expr) = chainon (ASM_INPUTS (expr), input);
2799 for (link = ASM_INPUTS (expr); link; ++i, link = TREE_CHAIN (link))
2802 = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (link)));
2803 parse_input_constraint (&constraint, 0, 0, noutputs, 0,
2804 oconstraints, &allows_mem, &allows_reg);
2806 /* If the operand is a memory input, it should be an lvalue. */
2807 if (!allows_reg && allows_mem)
2809 lang_hooks.mark_addressable (TREE_VALUE (link));
2810 tret = gimplify_expr (&TREE_VALUE (link), pre_p, post_p,
2811 is_gimple_lvalue, fb_lvalue | fb_mayfail);
2812 if (tret == GS_ERROR)
2814 error ("memory input %d is not directly addressable", i);
2820 tret = gimplify_expr (&TREE_VALUE (link), pre_p, post_p,
2821 is_gimple_val, fb_rvalue);
2822 if (tret == GS_ERROR)
2830 /* Gimplify a CLEANUP_POINT_EXPR. Currently this works by adding
2831 WITH_CLEANUP_EXPRs to the prequeue as we encounter cleanups while
2832 gimplifying the body, and converting them to TRY_FINALLY_EXPRs when we
2833 return to this function.
2835 FIXME should we complexify the prequeue handling instead? Or use flags
2836 for all the cleanups and let the optimizer tighten them up? The current
2837 code seems pretty fragile; it will break on a cleanup within any
2838 non-conditional nesting. But any such nesting would be broken, anyway;
2839 we can't write a TRY_FINALLY_EXPR that starts inside a nesting construct
2840 and continues out of it. We can do that at the RTL level, though, so
2841 having an optimizer to tighten up try/finally regions would be a Good
2844 static enum gimplify_status
2845 gimplify_cleanup_point_expr (tree *expr_p, tree *pre_p)
2847 tree_stmt_iterator iter;
2850 tree temp = voidify_wrapper_expr (*expr_p);
2852 /* We only care about the number of conditions between the innermost
2853 CLEANUP_POINT_EXPR and the cleanup. So save and reset the count. */
2854 int old_conds = gimplify_ctxp->conditions;
2855 gimplify_ctxp->conditions = 0;
2857 body = TREE_OPERAND (*expr_p, 0);
2858 gimplify_to_stmt_list (&body);
2860 gimplify_ctxp->conditions = old_conds;
2862 for (iter = tsi_start (body); !tsi_end_p (iter); )
2864 tree *wce_p = tsi_stmt_ptr (iter);
2867 if (TREE_CODE (wce) == WITH_CLEANUP_EXPR)
2869 if (tsi_one_before_end_p (iter))
2871 tsi_link_before (&iter, TREE_OPERAND (wce, 1), TSI_SAME_STMT);
2879 sl = tsi_split_statement_list_after (&iter);
2880 tfe = build (TRY_FINALLY_EXPR, void_type_node, sl, NULL_TREE);
2881 append_to_statement_list (TREE_OPERAND (wce, 1),
2882 &TREE_OPERAND (tfe, 1));
2884 iter = tsi_start (sl);
2894 append_to_statement_list (body, pre_p);
2904 /* Insert a cleanup marker for gimplify_cleanup_point_expr. CLEANUP
2905 is the cleanup action required. */
2908 gimple_push_cleanup (tree var, tree cleanup, tree *pre_p)
2912 /* Errors can result in improperly nested cleanups. Which results in
2913 confusion when trying to resolve the WITH_CLEANUP_EXPR. */
2914 if (errorcount || sorrycount)
2917 if (gimple_conditional_context ())
2919 /* If we're in a conditional context, this is more complex. We only
2920 want to run the cleanup if we actually ran the initialization that
2921 necessitates it, but we want to run it after the end of the
2922 conditional context. So we wrap the try/finally around the
2923 condition and use a flag to determine whether or not to actually
2924 run the destructor. Thus
2928 becomes (approximately)
2932 if (test) { A::A(temp); flag = 1; val = f(temp); }
2935 if (flag) A::~A(temp);
2940 tree flag = create_tmp_var (boolean_type_node, "cleanup");
2941 tree ffalse = build (MODIFY_EXPR, void_type_node, flag,
2942 boolean_false_node);
2943 tree ftrue = build (MODIFY_EXPR, void_type_node, flag,
2945 cleanup = build (COND_EXPR, void_type_node, flag, cleanup,
2946 build_empty_stmt ());
2947 wce = build (WITH_CLEANUP_EXPR, void_type_node, NULL_TREE,
2948 cleanup, NULL_TREE);
2949 append_to_statement_list (ffalse, &gimplify_ctxp->conditional_cleanups);
2950 append_to_statement_list (wce, &gimplify_ctxp->conditional_cleanups);
2951 append_to_statement_list (ftrue, pre_p);
2953 /* Because of this manipulation, and the EH edges that jump
2954 threading cannot redirect, the temporary (VAR) will appear
2955 to be used uninitialized. Don't warn. */
2956 TREE_NO_WARNING (var) = 1;
2960 wce = build (WITH_CLEANUP_EXPR, void_type_node, NULL_TREE,
2961 cleanup, NULL_TREE);
2962 append_to_statement_list (wce, pre_p);
2965 gimplify_stmt (&TREE_OPERAND (wce, 1));
2968 /* Gimplify a TARGET_EXPR which doesn't appear on the rhs of an INIT_EXPR. */
2970 static enum gimplify_status
2971 gimplify_target_expr (tree *expr_p, tree *pre_p, tree *post_p)
2973 tree targ = *expr_p;
2974 tree temp = TARGET_EXPR_SLOT (targ);
2975 tree init = TARGET_EXPR_INITIAL (targ);
2976 enum gimplify_status ret;
2980 /* TARGET_EXPR temps aren't part of the enclosing block, so add it to the
2982 gimple_add_tmp_var (temp);
2984 /* Build up the initialization and add it to pre_p. */
2985 init = build (MODIFY_EXPR, void_type_node, temp, init);
2986 ret = gimplify_expr (&init, pre_p, post_p, is_gimple_stmt, fb_none);
2987 if (ret == GS_ERROR)
2990 append_to_statement_list (init, pre_p);
2992 /* If needed, push the cleanup for the temp. */
2993 if (TARGET_EXPR_CLEANUP (targ))
2995 gimplify_stmt (&TARGET_EXPR_CLEANUP (targ));
2996 gimple_push_cleanup (temp, TARGET_EXPR_CLEANUP (targ), pre_p);
2999 /* Only expand this once. */
3000 TREE_OPERAND (targ, 3) = init;
3001 TARGET_EXPR_INITIAL (targ) = NULL_TREE;
3003 else if (!temp->decl.seen_in_bind_expr)
3004 /* We should have expanded this before. */
3011 /* Gimplification of expression trees. */
3013 /* Gimplify an expression which appears at statement context; usually, this
3014 means replacing it with a suitably gimple STATEMENT_LIST. */
3017 gimplify_stmt (tree *stmt_p)
3019 gimplify_expr (stmt_p, NULL, NULL, is_gimple_stmt, fb_none);
3021 *stmt_p = alloc_stmt_list ();
3024 /* Similarly, but force the result to be a STATEMENT_LIST. */
3027 gimplify_to_stmt_list (tree *stmt_p)
3029 gimplify_stmt (stmt_p);
3030 if (TREE_CODE (*stmt_p) != STATEMENT_LIST)
3033 *stmt_p = alloc_stmt_list ();
3034 append_to_statement_list (t, stmt_p);
3039 /* Gimplifies the expression tree pointed by EXPR_P. Return 0 if
3040 gimplification failed.
3042 PRE_P points to the list where side effects that must happen before
3043 EXPR should be stored.
3045 POST_P points to the list where side effects that must happen after
3046 EXPR should be stored, or NULL if there is no suitable list. In
3047 that case, we copy the result to a temporary, emit the
3048 post-effects, and then return the temporary.
3050 GIMPLE_TEST_F points to a function that takes a tree T and
3051 returns nonzero if T is in the GIMPLE form requested by the
3052 caller. The GIMPLE predicates are in tree-gimple.c.
3054 This test is used twice. Before gimplification, the test is
3055 invoked to determine whether *EXPR_P is already gimple enough. If
3056 that fails, *EXPR_P is gimplified according to its code and
3057 GIMPLE_TEST_F is called again. If the test still fails, then a new
3058 temporary variable is created and assigned the value of the
3059 gimplified expression.
3061 FALLBACK tells the function what sort of a temporary we want. If the 1
3062 bit is set, an rvalue is OK. If the 2 bit is set, an lvalue is OK.
3063 If both are set, either is OK, but an lvalue is preferable.
3065 The return value is either GS_ERROR or GS_ALL_DONE, since this function
3066 iterates until solution. */
3068 enum gimplify_status
3069 gimplify_expr (tree *expr_p, tree *pre_p, tree *post_p,
3070 bool (* gimple_test_f) (tree), fallback_t fallback)
3073 tree internal_pre = NULL_TREE;
3074 tree internal_post = NULL_TREE;
3076 int is_statement = (pre_p == NULL);
3078 location_t saved_location;
3079 enum gimplify_status ret;
3081 save_expr = *expr_p;
3082 if (save_expr == NULL_TREE)
3085 /* We used to check the predicate here and return immediately if it
3086 succeeds. This is wrong; the design is for gimplification to be
3087 idempotent, and for the predicates to only test for valid forms, not
3088 whether they are fully simplified. */
3090 /* Set up our internal queues if needed. */
3092 pre_p = &internal_pre;
3094 post_p = &internal_post;
3096 saved_location = input_location;
3097 if (save_expr == error_mark_node)
3100 locus = EXPR_LOCUS (save_expr);
3102 input_location = *locus;
3104 /* Loop over the specific gimplifiers until the toplevel node
3105 remains the same. */
3108 /* Strip any uselessness. */
3109 STRIP_MAIN_TYPE_NOPS (*expr_p);
3111 /* Remember the expr. */
3112 save_expr = *expr_p;
3114 /* Die, die, die, my darling. */
3115 if (save_expr == error_mark_node
3116 || TREE_TYPE (save_expr) == error_mark_node)
3122 /* Do any language-specific gimplification. */
3123 ret = lang_hooks.gimplify_expr (expr_p, pre_p, post_p);
3126 if (*expr_p == NULL_TREE)
3128 if (*expr_p != save_expr)
3131 else if (ret != GS_UNHANDLED)
3135 switch (TREE_CODE (*expr_p))
3137 /* First deal with the special cases. */
3139 case POSTINCREMENT_EXPR:
3140 case POSTDECREMENT_EXPR:
3141 case PREINCREMENT_EXPR:
3142 case PREDECREMENT_EXPR:
3143 ret = gimplify_self_mod_expr (expr_p, pre_p, post_p,
3144 fallback != fb_none);
3148 ret = gimplify_array_ref (expr_p, pre_p, post_p,
3149 fallback & fb_lvalue);
3153 ret = gimplify_compound_lval (expr_p, pre_p, post_p,
3154 fallback & fb_lvalue);
3158 ret = gimplify_cond_expr (expr_p, pre_p, NULL_TREE);
3162 ret = gimplify_call_expr (expr_p, pre_p, gimple_test_f);
3169 ret = gimplify_compound_expr (expr_p, pre_p, fallback != fb_none);
3174 ret = gimplify_compound_lval (expr_p, pre_p, post_p,
3175 fallback & fb_lvalue);
3180 ret = gimplify_modify_expr (expr_p, pre_p, post_p,
3181 fallback != fb_none);
3184 case TRUTH_ANDIF_EXPR:
3185 case TRUTH_ORIF_EXPR:
3186 ret = gimplify_boolean_expr (expr_p);
3189 case TRUTH_NOT_EXPR:
3190 TREE_OPERAND (*expr_p, 0)
3191 = gimple_boolify (TREE_OPERAND (*expr_p, 0));
3192 ret = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p, post_p,
3193 is_gimple_val, fb_rvalue);
3194 recalculate_side_effects (*expr_p);
3198 ret = gimplify_addr_expr (expr_p, pre_p, post_p);
3202 /* Mark any _DECL inside the operand as volatile to avoid the
3203 optimizers messing around with it. FIXME: Remove this once
3204 VA_ARG_EXPRs are properly lowered. */
3205 walk_tree (&TREE_OPERAND (*expr_p, 0), mark_decls_volatile_r,
3208 /* va_arg expressions are in GIMPLE form already. */
3214 if (IS_EMPTY_STMT (*expr_p))
3220 if (VOID_TYPE_P (TREE_TYPE (*expr_p))
3221 || fallback == fb_none)
3223 /* Just strip a conversion to void (or in void context) and
3225 *expr_p = TREE_OPERAND (*expr_p, 0);
3229 ret = gimplify_conversion (expr_p);
3230 if (ret == GS_ERROR)
3232 if (*expr_p != save_expr)
3236 case FIX_TRUNC_EXPR:
3238 case FIX_FLOOR_EXPR:
3239 case FIX_ROUND_EXPR:
3240 /* unary_expr: ... | '(' cast ')' val | ... */
3241 ret = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p, post_p,
3242 is_gimple_val, fb_rvalue);
3243 recalculate_side_effects (*expr_p);
3247 ret = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p, post_p,
3248 is_gimple_reg, fb_rvalue);
3249 recalculate_side_effects (*expr_p);
3252 /* Constants need not be gimplified. */
3262 *expr_p = DECL_INITIAL (*expr_p);
3266 /* FIXME make this a decl. */
3271 ret = gimplify_bind_expr (expr_p, pre_p);
3275 ret = gimplify_loop_expr (expr_p, pre_p);
3279 ret = gimplify_switch_expr (expr_p, pre_p);
3282 case LABELED_BLOCK_EXPR:
3283 ret = gimplify_labeled_block_expr (expr_p);
3286 case EXIT_BLOCK_EXPR:
3287 ret = gimplify_exit_block_expr (expr_p);
3291 ret = gimplify_exit_expr (expr_p);
3295 /* If the target is not LABEL, then it is a computed jump
3296 and the target needs to be gimplified. */
3297 if (TREE_CODE (GOTO_DESTINATION (*expr_p)) != LABEL_DECL)
3298 ret = gimplify_expr (&GOTO_DESTINATION (*expr_p), pre_p,
3299 NULL, is_gimple_val, fb_rvalue);
3304 #ifdef ENABLE_CHECKING
3305 if (decl_function_context (LABEL_EXPR_LABEL (*expr_p)) != current_function_decl)
3310 case CASE_LABEL_EXPR:
3311 ret = gimplify_case_label_expr (expr_p);
3315 ret = gimplify_return_expr (*expr_p, pre_p);
3319 /* Don't reduce this in place; let gimplify_init_constructor work
3324 /* The following are special cases that are not handled by the
3325 original GIMPLE grammar. */
3327 /* SAVE_EXPR nodes are converted into a GIMPLE identifier and
3330 ret = gimplify_save_expr (expr_p, pre_p, post_p);
3335 enum gimplify_status r0, r1, r2;
3337 r0 = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p, post_p,
3338 is_gimple_min_lval, fb_either);
3339 r1 = gimplify_expr (&TREE_OPERAND (*expr_p, 1), pre_p, post_p,
3340 is_gimple_val, fb_rvalue);
3341 r2 = gimplify_expr (&TREE_OPERAND (*expr_p, 2), pre_p, post_p,
3342 is_gimple_val, fb_rvalue);
3343 recalculate_side_effects (*expr_p);
3345 ret = MIN (r0, MIN (r1, r2));
3349 case NON_LVALUE_EXPR:
3350 /* This should have been stripped above. */
3355 ret = gimplify_asm_expr (expr_p, pre_p, post_p);
3358 case TRY_FINALLY_EXPR:
3359 case TRY_CATCH_EXPR:
3360 gimplify_to_stmt_list (&TREE_OPERAND (*expr_p, 0));
3361 gimplify_to_stmt_list (&TREE_OPERAND (*expr_p, 1));
3365 case CLEANUP_POINT_EXPR:
3366 ret = gimplify_cleanup_point_expr (expr_p, pre_p);
3370 ret = gimplify_target_expr (expr_p, pre_p, post_p);
3374 gimplify_to_stmt_list (&CATCH_BODY (*expr_p));
3378 case EH_FILTER_EXPR:
3379 gimplify_to_stmt_list (&EH_FILTER_FAILURE (*expr_p));
3384 /* This moves much of the actual computation out of the
3385 VTABLE_REF. Perhaps this should be revisited once we want to
3386 do clever things with VTABLE_REFs. */
3387 ret = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p, post_p,
3388 is_gimple_min_lval, fb_lvalue);
3393 ret = gimplify_minimax_expr (expr_p, pre_p, post_p);
3397 /* We get here when taking the address of a label. We mark
3398 the label as "forced"; meaning it can never be removed and
3399 it is a potential target for any computed goto. */
3400 FORCED_LABEL (*expr_p) = 1;
3404 case STATEMENT_LIST:
3405 ret = gimplify_statement_list (expr_p);
3409 /* ??? If this is a local variable, and it has not been seen in any
3410 outer BIND_EXPR, then it's probably the result of a duplicate
3411 declaration, for which we've already issued an error. It would
3412 be really nice if the front end wouldn't leak these at all.
3413 Currently the only known culprit is C++ destructors, as seen
3414 in g++.old-deja/g++.jason/binding.C. */
3416 if (!TREE_STATIC (tmp) && !DECL_EXTERNAL (tmp)
3417 && decl_function_context (tmp) == current_function_decl
3418 && !tmp->decl.seen_in_bind_expr)
3420 #ifdef ENABLE_CHECKING
3421 if (!errorcount && !sorrycount)
3431 /* If *EXPR_P does not need to be special-cased, handle it
3432 according to its class. */
3433 if (TREE_CODE_CLASS (TREE_CODE (*expr_p)) == '1')
3434 ret = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p,
3435 post_p, is_gimple_val, fb_rvalue);
3436 else if (TREE_CODE_CLASS (TREE_CODE (*expr_p)) == '2'
3437 || TREE_CODE_CLASS (TREE_CODE (*expr_p)) == '<'
3438 || TREE_CODE (*expr_p) == TRUTH_AND_EXPR
3439 || TREE_CODE (*expr_p) == TRUTH_OR_EXPR
3440 || TREE_CODE (*expr_p) == TRUTH_XOR_EXPR)
3442 enum gimplify_status r0, r1;
3444 r0 = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p,
3445 post_p, is_gimple_val, fb_rvalue);
3446 r1 = gimplify_expr (&TREE_OPERAND (*expr_p, 1), pre_p,
3447 post_p, is_gimple_val, fb_rvalue);
3451 else if (TREE_CODE_CLASS (TREE_CODE (*expr_p)) == 'd'
3452 || TREE_CODE_CLASS (TREE_CODE (*expr_p)) == 'c')
3458 /* Fail if we don't know how to handle this tree code. */
3461 recalculate_side_effects (*expr_p);
3465 /* If we replaced *expr_p, gimplify again. */
3466 if (ret == GS_OK && (*expr_p == NULL || *expr_p == save_expr))
3469 while (ret == GS_OK);
3471 /* If we encountered an error_mark somewhere nested inside, either
3472 stub out the statement or propagate the error back out. */
3473 if (ret == GS_ERROR)
3476 *expr_p = build_empty_stmt ();
3480 #ifdef ENABLE_CHECKING
3481 /* This was only valid as a return value from the langhook, which
3482 we handled. Make sure it doesn't escape from any other context. */
3483 if (ret == GS_UNHANDLED)
3488 *expr_p = build_empty_stmt ();
3489 if (fallback == fb_none && !is_gimple_stmt (*expr_p))
3491 /* We aren't looking for a value, and we don't have a valid
3492 statement. If it doesn't have side-effects, throw it away. */
3493 if (!TREE_SIDE_EFFECTS (*expr_p))
3494 *expr_p = build_empty_stmt ();
3495 else if (!TREE_THIS_VOLATILE (*expr_p))
3496 /* We only handle volatiles here; anything else with side-effects
3497 must be converted to a valid statement before we get here. */
3499 else if (COMPLETE_TYPE_P (TREE_TYPE (*expr_p)))
3501 /* Historically, the compiler has treated a bare
3502 reference to a volatile lvalue as forcing a load. */
3503 tree tmp = create_tmp_var (TREE_TYPE (*expr_p), "vol");
3504 *expr_p = build (MODIFY_EXPR, TREE_TYPE (tmp), tmp, *expr_p);
3507 /* We can't do anything useful with a volatile reference to
3508 incomplete type, so just throw it away. */
3509 *expr_p = build_empty_stmt ();
3512 /* If we are gimplifying at the statement level, we're done. Tack
3513 everything together and replace the original statement with the
3517 if (internal_pre || internal_post)
3519 append_to_statement_list (*expr_p, &internal_pre);
3520 append_to_statement_list (internal_post, &internal_pre);
3521 annotate_all_with_locus (&internal_pre, input_location);
3522 *expr_p = internal_pre;
3527 /* Otherwise we're gimplifying a subexpression, so the resulting value is
3530 /* If it's sufficiently simple already, we're done. Unless we are
3531 handling some post-effects internally; if that's the case, we need to
3532 copy into a temp before adding the post-effects to the tree. */
3533 if (!internal_post && (*gimple_test_f) (*expr_p))
3536 /* Otherwise, we need to create a new temporary for the gimplified
3539 /* We can't return an lvalue if we have an internal postqueue. The
3540 object the lvalue refers to would (probably) be modified by the
3541 postqueue; we need to copy the value out first, which means an
3543 if ((fallback & fb_lvalue) && !internal_post
3544 && is_gimple_addr_expr_arg (*expr_p))
3546 /* An lvalue will do. Take the address of the expression, store it
3547 in a temporary, and replace the expression with an INDIRECT_REF of
3549 tmp = build_addr_expr (*expr_p);
3550 gimplify_expr (&tmp, pre_p, post_p, is_gimple_reg, fb_rvalue);
3551 *expr_p = build1 (INDIRECT_REF, TREE_TYPE (TREE_TYPE (tmp)), tmp);
3553 else if ((fallback & fb_rvalue) && is_gimple_rhs (*expr_p))
3555 #if defined ENABLE_CHECKING
3556 if (VOID_TYPE_P (TREE_TYPE (*expr_p)))
3560 /* An rvalue will do. Assign the gimplified expression into a new
3561 temporary TMP and replace the original expression with TMP. */
3563 if (internal_post || (fallback & fb_lvalue))
3564 /* The postqueue might change the value of the expression between
3565 the initialization and use of the temporary, so we can't use a
3566 formal temp. FIXME do we care? */
3567 *expr_p = get_initialized_tmp_var (*expr_p, pre_p, post_p);
3569 *expr_p = get_formal_tmp_var (*expr_p, pre_p);
3571 else if (fallback & fb_mayfail)
3573 /* If this is an asm statement, and the user asked for the impossible,
3574 don't abort. Fail and let gimplify_asm_expr issue an error. */
3580 fprintf (stderr, "gimplification failed:\n");
3581 print_generic_expr (stderr, *expr_p, 0);
3582 debug_tree (*expr_p);
3586 #if defined ENABLE_CHECKING
3587 /* Make sure the temporary matches our predicate. */
3588 if (!(*gimple_test_f) (*expr_p))
3594 annotate_all_with_locus (&internal_post, input_location);
3595 append_to_statement_list (internal_post, pre_p);
3599 input_location = saved_location;
3603 #ifdef ENABLE_CHECKING
3604 /* Compare types A and B for a "close enough" match. */
3607 cpt_same_type (tree a, tree b)
3609 if (lang_hooks.types_compatible_p (a, b))
3612 /* ??? The C++ FE decomposes METHOD_TYPES to FUNCTION_TYPES and doesn't
3613 link them together. This routine is intended to catch type errors
3614 that will affect the optimizers, and the optimizers don't add new
3615 dereferences of function pointers, so ignore it. */
3616 if ((TREE_CODE (a) == FUNCTION_TYPE || TREE_CODE (a) == METHOD_TYPE)
3617 && (TREE_CODE (b) == FUNCTION_TYPE || TREE_CODE (b) == METHOD_TYPE))
3620 /* ??? The C FE pushes type qualifiers after the fact into the type of
3621 the element from the type of the array. See build_unary_op's handling
3622 of ADDR_EXPR. This seems wrong -- if we were going to do this, we
3623 should have done it when creating the variable in the first place.
3624 Alternately, why aren't the two array types made variants? */
3625 if (TREE_CODE (a) == ARRAY_TYPE && TREE_CODE (b) == ARRAY_TYPE)
3626 return cpt_same_type (TREE_TYPE (a), TREE_TYPE (b));
3628 /* And because of those, we have to recurse down through pointers. */
3629 if (POINTER_TYPE_P (a) && POINTER_TYPE_P (b))
3630 return cpt_same_type (TREE_TYPE (a), TREE_TYPE (b));
3635 /* Check for some cases of the front end missing cast expressions.
3636 The type of a dereference should correspond to the pointer type;
3637 similarly the type of an address should match its object. */
3640 check_pointer_types_r (tree *tp, int *walk_subtrees ATTRIBUTE_UNUSED,
3641 void *data ATTRIBUTE_UNUSED)
3644 tree ptype, otype, dtype;
3646 switch (TREE_CODE (t))
3650 otype = TREE_TYPE (t);
3651 ptype = TREE_TYPE (TREE_OPERAND (t, 0));
3652 dtype = TREE_TYPE (ptype);
3653 if (!cpt_same_type (otype, dtype))
3658 ptype = TREE_TYPE (t);
3659 otype = TREE_TYPE (TREE_OPERAND (t, 0));
3660 dtype = TREE_TYPE (ptype);
3661 if (!cpt_same_type (otype, dtype))
3663 /* &array is allowed to produce a pointer to the element,
3664 rather than a pointer to the array type. */
3665 if (TREE_CODE (otype) == ARRAY_TYPE
3666 && POINTER_TYPE_P (ptype)
3667 && cpt_same_type (TREE_TYPE (otype), dtype))
3682 /* Gimplify the body of statements pointed by BODY_P. FNDECL is the
3683 function decl containing BODY. */
3686 gimplify_body (tree *body_p, tree fndecl)
3688 location_t saved_location = input_location;
3691 timevar_push (TV_TREE_GIMPLIFY);
3692 push_gimplify_context ();
3694 /* Unshare most shared trees in the body. */
3695 unshare_all_trees (*body_p);
3697 /* Make sure input_location isn't set to something wierd. */
3698 input_location = DECL_SOURCE_LOCATION (fndecl);
3700 /* Gimplify the function's body. */
3701 gimplify_stmt (body_p);
3704 /* Unshare again, in case gimplification was sloppy. */
3705 unshare_all_trees (body);
3707 /* If there isn't an outer BIND_EXPR, add one. */
3708 if (TREE_CODE (body) == STATEMENT_LIST)
3710 tree t = expr_only (*body_p);
3714 if (TREE_CODE (body) != BIND_EXPR)
3716 tree b = build (BIND_EXPR, void_type_node, NULL_TREE,
3717 NULL_TREE, NULL_TREE);
3718 TREE_SIDE_EFFECTS (b) = 1;
3719 append_to_statement_list_force (body, &BIND_EXPR_BODY (b));
3724 pop_gimplify_context (body);
3726 #ifdef ENABLE_CHECKING
3727 walk_tree (body_p, check_pointer_types_r, NULL, NULL);
3730 timevar_pop (TV_TREE_GIMPLIFY);
3731 input_location = saved_location;
3734 /* Entry point to the gimplification pass. FNDECL is the FUNCTION_DECL
3735 node for the function we want to gimplify. */
3738 gimplify_function_tree (tree fndecl)
3742 oldfn = current_function_decl;
3743 current_function_decl = fndecl;
3745 gimplify_body (&DECL_SAVED_TREE (fndecl), fndecl);
3747 /* If we're instrumenting function entry/exit, then prepend the call to
3748 the entry hook and wrap the whole function in a TRY_FINALLY_EXPR to
3749 catch the exit hook. */
3750 /* ??? Add some way to ignore exceptions for this TFE. */
3751 if (flag_instrument_function_entry_exit
3752 && ! DECL_NO_INSTRUMENT_FUNCTION_ENTRY_EXIT (fndecl))
3756 tf = build (TRY_FINALLY_EXPR, void_type_node, NULL, NULL);
3757 TREE_SIDE_EFFECTS (tf) = 1;
3758 x = DECL_SAVED_TREE (fndecl);
3759 append_to_statement_list (x, &TREE_OPERAND (tf, 0));
3760 x = implicit_built_in_decls[BUILT_IN_PROFILE_FUNC_EXIT];
3761 x = build_function_call_expr (x, NULL);
3762 append_to_statement_list (x, &TREE_OPERAND (tf, 1));
3764 bind = build (BIND_EXPR, void_type_node, NULL, NULL, NULL);
3765 TREE_SIDE_EFFECTS (bind) = 1;
3766 x = implicit_built_in_decls[BUILT_IN_PROFILE_FUNC_ENTER];
3767 x = build_function_call_expr (x, NULL);
3768 append_to_statement_list (x, &BIND_EXPR_BODY (bind));
3769 append_to_statement_list (tf, &BIND_EXPR_BODY (bind));
3771 DECL_SAVED_TREE (fndecl) = bind;
3774 current_function_decl = oldfn;
3777 #include "gt-gimplify.h"