1 /* Tree lowering pass. This pass converts the GENERIC functions-as-trees
2 tree representation into the GIMPLE form.
3 Copyright (C) 2002, 2003, 2004 Free Software Foundation, Inc.
4 Major work done by Sebastian Pop <s.pop@laposte.net>,
5 Diego Novillo <dnovillo@redhat.com> and Jason Merrill <jason@redhat.com>.
7 This file is part of GCC.
9 GCC is free software; you can redistribute it and/or modify it under
10 the terms of the GNU General Public License as published by the Free
11 Software Foundation; either version 2, or (at your option) any later
14 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
15 WARRANTY; without even the implied warranty of MERCHANTABILITY or
16 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
19 You should have received a copy of the GNU General Public License
20 along with GCC; see the file COPYING. If not, write to the Free
21 Software Foundation, 59 Temple Place - Suite 330, Boston, MA
26 #include "coretypes.h"
32 #include "tree-gimple.h"
33 #include "tree-inline.h"
34 #include "diagnostic.h"
35 #include "langhooks.h"
36 #include "langhooks-def.h"
37 #include "tree-flow.h"
50 static struct gimplify_ctx
52 tree current_bind_expr;
55 tree conditional_cleanups;
59 varray_type case_labels;
60 /* The formal temporary table. Should this be persistent? */
65 /* Formal (expression) temporary table handling: Multiple occurrences of
66 the same scalar expression are evaluated into the same temporary. */
68 typedef struct gimple_temp_hash_elt
71 tree temp; /* Value */
74 /* Forward declarations. */
75 static enum gimplify_status gimplify_modify_expr_rhs (tree *, tree *, tree *,
76 tree *, tree *, bool);
77 static enum gimplify_status gimplify_compound_expr (tree *, tree *, bool);
80 /* Return a hash value for a formal temporary table entry. */
83 gimple_tree_hash (const void *p)
85 tree t = ((const elt_t *) p)->val;
86 return iterative_hash_expr (t, 0);
89 /* Compare two formal temporary table entries. */
92 gimple_tree_eq (const void *p1, const void *p2)
94 tree t1 = ((const elt_t *) p1)->val;
95 tree t2 = ((const elt_t *) p2)->val;
96 enum tree_code code = TREE_CODE (t1);
98 if (TREE_CODE (t2) != code
99 || TREE_TYPE (t1) != TREE_TYPE (t2))
102 if (!operand_equal_p (t1, t2, 0))
105 /* Only allow them to compare equal if they also hash equal; otherwise
106 results are nondeterminate, and we fail bootstrap comparison. */
107 if (gimple_tree_hash (p1) != gimple_tree_hash (p2))
113 /* Set up a context for the gimplifier. */
116 push_gimplify_context (void)
121 = (struct gimplify_ctx *) xcalloc (1, sizeof (struct gimplify_ctx));
122 gimplify_ctxp->temp_htab
123 = htab_create (1000, gimple_tree_hash, gimple_tree_eq, free);
126 /* Tear down a context for the gimplifier. If BODY is non-null, then
127 put the temporaries into the outer BIND_EXPR. Otherwise, put them
128 in the unexpanded_var_list. */
131 pop_gimplify_context (tree body)
133 if (!gimplify_ctxp || gimplify_ctxp->current_bind_expr)
137 declare_tmp_vars (gimplify_ctxp->temps, body);
139 record_vars (gimplify_ctxp->temps);
143 fprintf (stderr, " collisions: %f ",
144 htab_collisions (gimplify_ctxp->temp_htab));
147 htab_delete (gimplify_ctxp->temp_htab);
148 free (gimplify_ctxp);
149 gimplify_ctxp = NULL;
153 gimple_push_bind_expr (tree bind)
155 TREE_CHAIN (bind) = gimplify_ctxp->current_bind_expr;
156 gimplify_ctxp->current_bind_expr = bind;
160 gimple_pop_bind_expr (void)
162 gimplify_ctxp->current_bind_expr
163 = TREE_CHAIN (gimplify_ctxp->current_bind_expr);
167 gimple_current_bind_expr (void)
169 return gimplify_ctxp->current_bind_expr;
172 /* Returns true iff there is a COND_EXPR between us and the innermost
173 CLEANUP_POINT_EXPR. This info is used by gimple_push_cleanup. */
176 gimple_conditional_context (void)
178 return gimplify_ctxp->conditions > 0;
181 /* Note that we've entered a COND_EXPR. */
184 gimple_push_condition (void)
186 ++(gimplify_ctxp->conditions);
189 /* Note that we've left a COND_EXPR. If we're back at unconditional scope
190 now, add any conditional cleanups we've seen to the prequeue. */
193 gimple_pop_condition (tree *pre_p)
195 int conds = --(gimplify_ctxp->conditions);
199 append_to_statement_list (gimplify_ctxp->conditional_cleanups, pre_p);
200 gimplify_ctxp->conditional_cleanups = NULL_TREE;
206 /* A subroutine of append_to_statement_list{,_force}. */
209 append_to_statement_list_1 (tree t, tree *list_p, bool side_effects)
212 tree_stmt_iterator i;
219 if (t && TREE_CODE (t) == STATEMENT_LIST)
224 *list_p = list = alloc_stmt_list ();
228 tsi_link_after (&i, t, TSI_CONTINUE_LINKING);
231 /* Add T to the end of the list container pointed by LIST_P.
232 If T is an expression with no effects, it is ignored. */
235 append_to_statement_list (tree t, tree *list_p)
237 append_to_statement_list_1 (t, list_p, t ? TREE_SIDE_EFFECTS (t) : false);
240 /* Similar, but the statement is always added, regardless of side effects. */
243 append_to_statement_list_force (tree t, tree *list_p)
245 append_to_statement_list_1 (t, list_p, t != NULL);
248 /* Both gimplify the statement T and append it to LIST_P. */
251 gimplify_and_add (tree t, tree *list_p)
254 append_to_statement_list (t, list_p);
257 /* Strip off a legitimate source ending from the input string NAME of
258 length LEN. Rather than having to know the names used by all of
259 our front ends, we strip off an ending of a period followed by
260 up to five characters. (Java uses ".class".) */
263 remove_suffix (char *name, int len)
267 for (i = 2; i < 8 && len > i; i++)
269 if (name[len - i] == '.')
271 name[len - i] = '\0';
277 /* Create a nameless artificial label and put it in the current function
278 context. Returns the newly created label. */
281 create_artificial_label (void)
283 tree lab = build_decl (LABEL_DECL, NULL_TREE, void_type_node);
285 DECL_ARTIFICIAL (lab) = 1;
286 DECL_CONTEXT (lab) = current_function_decl;
290 /* Create a new temporary name with PREFIX. Returns an identifier. */
292 static GTY(()) unsigned int tmp_var_id_num;
295 create_tmp_var_name (const char *prefix)
301 char *preftmp = ASTRDUP (prefix);
303 remove_suffix (preftmp, strlen (preftmp));
307 ASM_FORMAT_PRIVATE_NAME (tmp_name, prefix ? prefix : "T", tmp_var_id_num++);
308 return get_identifier (tmp_name);
312 /* Create a new temporary variable declaration of type TYPE.
313 Does NOT push it into the current binding. */
316 create_tmp_var_raw (tree type, const char *prefix)
321 /* Make the type of the variable writable. */
322 new_type = build_type_variant (type, 0, 0);
323 TYPE_ATTRIBUTES (new_type) = TYPE_ATTRIBUTES (type);
325 tmp_var = build_decl (VAR_DECL, create_tmp_var_name (prefix), type);
327 /* The variable was declared by the compiler. */
328 DECL_ARTIFICIAL (tmp_var) = 1;
329 /* And we don't want debug info for it. */
330 DECL_IGNORED_P (tmp_var) = 1;
332 /* Make the variable writable. */
333 TREE_READONLY (tmp_var) = 0;
335 DECL_EXTERNAL (tmp_var) = 0;
336 TREE_STATIC (tmp_var) = 0;
337 TREE_USED (tmp_var) = 1;
342 /* Create a new temporary variable declaration of type TYPE. DOES push the
343 variable into the current binding. Further, assume that this is called
344 only from gimplification or optimization, at which point the creation of
345 certain types are bugs. */
348 create_tmp_var (tree type, const char *prefix)
352 #if defined ENABLE_CHECKING
353 /* We don't allow types that are addressable (meaning we can't make copies),
354 incomplete, or of variable size. */
355 if (TREE_ADDRESSABLE (type)
356 || !COMPLETE_TYPE_P (type)
357 || TREE_CODE (TYPE_SIZE_UNIT (type)) != INTEGER_CST)
361 tmp_var = create_tmp_var_raw (type, prefix);
362 gimple_add_tmp_var (tmp_var);
366 /* Given a tree, try to return a useful variable name that we can use
367 to prefix a temporary that is being assigned the value of the tree.
368 I.E. given <temp> = &A, return A. */
376 STRIP_NOPS (stripped_decl);
377 if (DECL_P (stripped_decl) && DECL_NAME (stripped_decl))
378 return IDENTIFIER_POINTER (DECL_NAME (stripped_decl));
381 switch (TREE_CODE (stripped_decl))
384 return get_name (TREE_OPERAND (stripped_decl, 0));
392 /* Create a temporary with a name derived from VAL. Subroutine of
393 lookup_tmp_var; nobody else should call this function. */
396 create_tmp_from_val (tree val)
398 return create_tmp_var (TREE_TYPE (val), get_name (val));
401 /* Create a temporary to hold the value of VAL. If IS_FORMAL, try to reuse
402 an existing expression temporary. */
405 lookup_tmp_var (tree val, bool is_formal)
407 if (!is_formal || TREE_SIDE_EFFECTS (val))
408 return create_tmp_from_val (val);
415 slot = htab_find_slot (gimplify_ctxp->temp_htab, (void *)&elt, INSERT);
418 elt_p = xmalloc (sizeof (*elt_p));
420 elt_p->temp = create_tmp_from_val (val);
421 TREE_READONLY (elt_p->temp) = 1;
422 *slot = (void *) elt_p;
425 elt_p = (elt_t *) *slot;
431 /* Returns a formal temporary variable initialized with VAL. PRE_P is as
432 in gimplify_expr. Only use this function if:
434 1) The value of the unfactored expression represented by VAL will not
435 change between the initialization and use of the temporary, and
436 2) The temporary will not be otherwise modified.
438 For instance, #1 means that this is inappropriate for SAVE_EXPR temps,
439 and #2 means it is inappropriate for && temps.
441 For other cases, use get_initialized_tmp_var instead. */
444 internal_get_tmp_var (tree val, tree *pre_p, tree *post_p, bool is_formal)
449 gimplify_expr (&val, pre_p, post_p, is_gimple_rhs, fb_rvalue);
451 t = lookup_tmp_var (val, is_formal);
453 mod = build (MODIFY_EXPR, TREE_TYPE (t), t, val);
455 class = TREE_CODE_CLASS (TREE_CODE (val));
456 if (EXPR_HAS_LOCATION (val))
457 SET_EXPR_LOCUS (mod, EXPR_LOCUS (val));
459 SET_EXPR_LOCATION (mod, input_location);
461 /* gimplify_modify_expr might want to reduce this further. */
462 gimplify_and_add (mod, pre_p);
467 get_formal_tmp_var (tree val, tree *pre_p)
469 return internal_get_tmp_var (val, pre_p, NULL, true);
472 /* Returns a temporary variable initialized with VAL. PRE_P and POST_P
473 are as in gimplify_expr. */
476 get_initialized_tmp_var (tree val, tree *pre_p, tree *post_p)
478 return internal_get_tmp_var (val, pre_p, post_p, false);
481 /* Returns true if T is a GIMPLE temporary variable, false otherwise. */
484 is_gimple_tmp_var (tree t)
486 /* FIXME this could trigger for other local artificials, too. */
487 return (TREE_CODE (t) == VAR_DECL && DECL_ARTIFICIAL (t)
488 && !TREE_STATIC (t) && !DECL_EXTERNAL (t));
491 /* Declares all the variables in VARS in SCOPE. */
494 declare_tmp_vars (tree vars, tree scope)
501 /* C99 mode puts the default 'return 0;' for main outside the outer
502 braces. So drill down until we find an actual scope. */
503 while (TREE_CODE (scope) == COMPOUND_EXPR)
504 scope = TREE_OPERAND (scope, 0);
506 if (TREE_CODE (scope) != BIND_EXPR)
509 temps = nreverse (last);
510 TREE_CHAIN (last) = BIND_EXPR_VARS (scope);
511 BIND_EXPR_VARS (scope) = temps;
513 /* We don't add the temps to the block for this BIND_EXPR, as we're
514 not interested in debugging info for them. */
519 gimple_add_tmp_var (tree tmp)
521 if (TREE_CHAIN (tmp) || tmp->decl.seen_in_bind_expr)
524 DECL_CONTEXT (tmp) = current_function_decl;
525 tmp->decl.seen_in_bind_expr = 1;
529 TREE_CHAIN (tmp) = gimplify_ctxp->temps;
530 gimplify_ctxp->temps = tmp;
535 declare_tmp_vars (tmp, DECL_SAVED_TREE (current_function_decl));
538 /* Determines whether to assign a locus to the statement STMT. */
541 should_carry_locus_p (tree stmt)
543 /* Don't emit a line note for a label. We particularly don't want to
544 emit one for the break label, since it doesn't actually correspond
545 to the beginning of the loop/switch. */
546 if (TREE_CODE (stmt) == LABEL_EXPR)
549 /* Do not annotate empty statements, since it confuses gcov. */
550 if (!TREE_SIDE_EFFECTS (stmt))
557 annotate_one_with_locus (tree t, location_t locus)
559 if (IS_EXPR_CODE_CLASS (TREE_CODE_CLASS (TREE_CODE (t)))
560 && ! EXPR_HAS_LOCATION (t)
561 && should_carry_locus_p (t))
562 SET_EXPR_LOCATION (t, locus);
566 annotate_all_with_locus (tree *stmt_p, location_t locus)
568 tree_stmt_iterator i;
573 for (i = tsi_start (*stmt_p); !tsi_end_p (i); tsi_next (&i))
575 tree t = tsi_stmt (i);
577 #ifdef ENABLE_CHECKING
578 /* Assuming we've already been gimplified, we shouldn't
579 see nested chaining constructs anymore. */
580 if (TREE_CODE (t) == STATEMENT_LIST
581 || TREE_CODE (t) == COMPOUND_EXPR)
585 annotate_one_with_locus (t, locus);
589 /* Similar to copy_tree_r() but do not copy SAVE_EXPR or TARGET_EXPR nodes.
590 These nodes model computations that should only be done once. If we
591 were to unshare something like SAVE_EXPR(i++), the gimplification
592 process would create wrong code. */
595 mostly_copy_tree_r (tree *tp, int *walk_subtrees, void *data)
597 enum tree_code code = TREE_CODE (*tp);
598 /* Don't unshare types, decls, constants and SAVE_EXPR nodes. */
599 if (TREE_CODE_CLASS (code) == 't'
600 || TREE_CODE_CLASS (code) == 'd'
601 || TREE_CODE_CLASS (code) == 'c'
602 || code == SAVE_EXPR || code == TARGET_EXPR
603 /* We can't do anything sensible with a BLOCK used as an expression,
604 but we also can't abort when we see it because of non-expression
605 uses. So just avert our eyes and cross our fingers. Silly Java. */
608 else if (code == BIND_EXPR)
611 copy_tree_r (tp, walk_subtrees, data);
616 /* Mark all the _DECL nodes under *TP as volatile. FIXME: This must die
617 after VA_ARG_EXPRs are properly lowered. */
620 mark_decls_volatile_r (tree *tp, int *walk_subtrees ATTRIBUTE_UNUSED,
621 void *data ATTRIBUTE_UNUSED)
624 TREE_THIS_VOLATILE (*tp) = 1;
630 /* Callback for walk_tree to unshare most of the shared trees rooted at
631 *TP. If *TP has been visited already (i.e., TREE_VISITED (*TP) == 1),
632 then *TP is deep copied by calling copy_tree_r.
634 This unshares the same trees as copy_tree_r with the exception of
635 SAVE_EXPR nodes. These nodes model computations that should only be
636 done once. If we were to unshare something like SAVE_EXPR(i++), the
637 gimplification process would create wrong code. */
640 copy_if_shared_r (tree *tp, int *walk_subtrees ATTRIBUTE_UNUSED,
641 void *data ATTRIBUTE_UNUSED)
644 enum tree_code code = TREE_CODE (t);
646 /* Skip types, decls, and constants. But we do want to look at their
647 types and the bounds of types. Mark them as visited so we properly
648 unmark their subtrees on the unmark pass. If we've already seen them,
649 don't look down further. */
650 if (TREE_CODE_CLASS (code) == 't'
651 || TREE_CODE_CLASS (code) == 'd'
652 || TREE_CODE_CLASS (code) == 'c')
654 if (TREE_VISITED (t))
657 TREE_VISITED (t) = 1;
660 /* Special-case BIND_EXPR. We should never be copying these, therefore
661 we can omit examining BIND_EXPR_VARS. Which also avoids problems with
662 double processing of the DECL_INITIAL, which could be seen via both
663 the BIND_EXPR_VARS and a DECL_EXPR. */
664 else if (code == BIND_EXPR)
666 if (TREE_VISITED (t))
668 TREE_VISITED (t) = 1;
670 walk_tree (&BIND_EXPR_BODY (t), copy_if_shared_r, NULL, NULL);
673 /* If this node has been visited already, unshare it and don't look
675 else if (TREE_VISITED (t))
677 walk_tree (tp, mostly_copy_tree_r, NULL, NULL);
681 /* Otherwise, mark the tree as visited and keep looking. */
684 TREE_VISITED (t) = 1;
685 if (TREE_CODE (*tp) == VA_ARG_EXPR
686 && targetm.calls.gimplify_va_arg_expr == NULL)
688 /* Mark any _DECL inside the operand as volatile to avoid
689 the optimizers messing around with it. We have to do this
690 early, otherwise we might mark a variable as volatile
691 after we gimplify other statements that use the variable
692 assuming it's not volatile. */
694 /* FIXME once most targets define the above hook, this should
695 go away (perhaps along with the #include "target.h"). */
696 walk_tree (&TREE_OPERAND (*tp, 0), mark_decls_volatile_r,
705 unmark_visited_r (tree *tp, int *walk_subtrees ATTRIBUTE_UNUSED,
706 void *data ATTRIBUTE_UNUSED)
708 if (TREE_VISITED (*tp))
709 TREE_VISITED (*tp) = 0;
716 /* Unshare all the trees in BODY_P, a pointer to the body of FNDECL, and the
717 bodies of any nested functions. */
720 unshare_body (tree *body_p, tree fndecl)
722 struct cgraph_node *cgn = cgraph_node (fndecl);
724 walk_tree (body_p, copy_if_shared_r, NULL, NULL);
725 for (cgn = cgn->nested; cgn; cgn = cgn->next_nested)
726 unshare_body (&DECL_SAVED_TREE (cgn->decl), cgn->decl);
729 /* Likewise, but mark all trees as not visited. */
732 unvisit_body (tree *body_p, tree fndecl)
734 struct cgraph_node *cgn = cgraph_node (fndecl);
736 walk_tree (body_p, unmark_visited_r, NULL, NULL);
737 for (cgn = cgn->nested; cgn; cgn = cgn->next_nested)
738 unvisit_body (&DECL_SAVED_TREE (cgn->decl), cgn->decl);
741 /* Unshare T and all the trees reached from T via TREE_CHAIN. */
744 unshare_all_trees (tree t)
746 walk_tree (&t, copy_if_shared_r, NULL, NULL);
747 walk_tree (&t, unmark_visited_r, NULL, NULL);
750 /* Unconditionally make an unshared copy of EXPR. This is used when using
751 stored expressions which span multiple functions, such as BINFO_VTABLE,
752 as the normal unsharing process can't tell that they're shared. */
755 unshare_expr (tree expr)
757 walk_tree (&expr, mostly_copy_tree_r, NULL, NULL);
761 /* A terser interface for building a representation of a exception
765 gimple_build_eh_filter (tree body, tree allowed, tree failure)
769 /* FIXME should the allowed types go in TREE_TYPE? */
770 t = build (EH_FILTER_EXPR, void_type_node, allowed, NULL_TREE);
771 append_to_statement_list (failure, &EH_FILTER_FAILURE (t));
773 t = build (TRY_CATCH_EXPR, void_type_node, NULL_TREE, t);
774 append_to_statement_list (body, &TREE_OPERAND (t, 0));
780 /* WRAPPER is a code such as BIND_EXPR or CLEANUP_POINT_EXPR which can both
781 contain statements and have a value. Assign its value to a temporary
782 and give it void_type_node. Returns the temporary, or NULL_TREE if
783 WRAPPER was already void. */
786 voidify_wrapper_expr (tree wrapper, tree temp)
788 if (!VOID_TYPE_P (TREE_TYPE (wrapper)))
790 tree *p, sub = wrapper;
793 /* Set p to point to the body of the wrapper. */
794 switch (TREE_CODE (sub))
797 /* For a BIND_EXPR, the body is operand 1. */
798 p = &BIND_EXPR_BODY (sub);
802 p = &TREE_OPERAND (sub, 0);
806 /* Advance to the last statement. Set all container types to void. */
807 if (TREE_CODE (*p) == STATEMENT_LIST)
809 tree_stmt_iterator i = tsi_last (*p);
810 p = tsi_end_p (i) ? NULL : tsi_stmt_ptr (i);
814 for (; TREE_CODE (*p) == COMPOUND_EXPR; p = &TREE_OPERAND (*p, 1))
816 TREE_SIDE_EFFECTS (*p) = 1;
817 TREE_TYPE (*p) = void_type_node;
821 if (p == NULL || IS_EMPTY_STMT (*p))
823 /* Look through exception handling. */
824 else if (TREE_CODE (*p) == TRY_FINALLY_EXPR
825 || TREE_CODE (*p) == TRY_CATCH_EXPR)
830 /* The C++ frontend already did this for us. */
831 else if (TREE_CODE (*p) == INIT_EXPR
832 || TREE_CODE (*p) == TARGET_EXPR)
833 temp = TREE_OPERAND (*p, 0);
834 /* If we're returning a dereference, move the dereference
835 outside the wrapper. */
836 else if (TREE_CODE (*p) == INDIRECT_REF)
838 tree ptr = TREE_OPERAND (*p, 0);
839 temp = create_tmp_var (TREE_TYPE (ptr), "retval");
840 *p = build (MODIFY_EXPR, TREE_TYPE (ptr), temp, ptr);
841 temp = build1 (INDIRECT_REF, TREE_TYPE (TREE_TYPE (temp)), temp);
842 /* If this is a BIND_EXPR for a const inline function, it might not
843 have TREE_SIDE_EFFECTS set. That is no longer accurate. */
844 TREE_SIDE_EFFECTS (wrapper) = 1;
849 temp = create_tmp_var (TREE_TYPE (wrapper), "retval");
850 *p = build (MODIFY_EXPR, TREE_TYPE (temp), temp, *p);
851 TREE_SIDE_EFFECTS (wrapper) = 1;
854 TREE_TYPE (wrapper) = void_type_node;
861 /* Prepare calls to builtins to SAVE and RESTORE the stack as well as
862 a temporary through which they communicate. */
865 build_stack_save_restore (tree *save, tree *restore)
867 tree save_call, tmp_var;
870 build_function_call_expr (implicit_built_in_decls[BUILT_IN_STACK_SAVE],
872 tmp_var = create_tmp_var (ptr_type_node, "saved_stack");
874 *save = build (MODIFY_EXPR, ptr_type_node, tmp_var, save_call);
876 build_function_call_expr (implicit_built_in_decls[BUILT_IN_STACK_RESTORE],
877 tree_cons (NULL_TREE, tmp_var, NULL_TREE));
880 /* Gimplify a BIND_EXPR. Just voidify and recurse. */
882 static enum gimplify_status
883 gimplify_bind_expr (tree *expr_p, tree temp, tree *pre_p)
885 tree bind_expr = *expr_p;
886 bool old_save_stack = gimplify_ctxp->save_stack;
889 temp = voidify_wrapper_expr (bind_expr, temp);
891 /* Mark variables seen in this bind expr. */
892 for (t = BIND_EXPR_VARS (bind_expr); t ; t = TREE_CHAIN (t))
893 t->decl.seen_in_bind_expr = 1;
895 gimple_push_bind_expr (bind_expr);
896 gimplify_ctxp->save_stack = false;
898 gimplify_to_stmt_list (&BIND_EXPR_BODY (bind_expr));
900 if (gimplify_ctxp->save_stack)
902 tree stack_save, stack_restore;
904 /* Save stack on entry and restore it on exit. Add a try_finally
905 block to achieve this. Note that mudflap depends on the
906 format of the emitted code: see mx_register_decls(). */
907 build_stack_save_restore (&stack_save, &stack_restore);
909 t = build (TRY_FINALLY_EXPR, void_type_node,
910 BIND_EXPR_BODY (bind_expr), NULL_TREE);
911 append_to_statement_list (stack_restore, &TREE_OPERAND (t, 1));
913 BIND_EXPR_BODY (bind_expr) = NULL_TREE;
914 append_to_statement_list (stack_save, &BIND_EXPR_BODY (bind_expr));
915 append_to_statement_list (t, &BIND_EXPR_BODY (bind_expr));
918 gimplify_ctxp->save_stack = old_save_stack;
919 gimple_pop_bind_expr ();
924 append_to_statement_list (bind_expr, pre_p);
931 /* Gimplify a RETURN_EXPR. If the expression to be returned is not a
932 GIMPLE value, it is assigned to a new temporary and the statement is
933 re-written to return the temporary.
935 PRE_P points to the list where side effects that must happen before
936 STMT should be stored. */
938 static enum gimplify_status
939 gimplify_return_expr (tree stmt, tree *pre_p)
941 tree ret_expr = TREE_OPERAND (stmt, 0);
942 tree result_decl, result;
944 if (!ret_expr || TREE_CODE (ret_expr) == RESULT_DECL)
947 if (ret_expr == error_mark_node)
950 if (VOID_TYPE_P (TREE_TYPE (TREE_TYPE (current_function_decl))))
951 result_decl = NULL_TREE;
954 result_decl = TREE_OPERAND (ret_expr, 0);
955 #ifdef ENABLE_CHECKING
956 if ((TREE_CODE (ret_expr) != MODIFY_EXPR
957 && TREE_CODE (ret_expr) != INIT_EXPR)
958 || TREE_CODE (result_decl) != RESULT_DECL)
963 /* If aggregate_value_p is true, then we can return the bare RESULT_DECL.
964 Recall that aggregate_value_p is FALSE for any aggregate type that is
965 returned in registers. If we're returning values in registers, then
966 we don't want to extend the lifetime of the RESULT_DECL, particularly
967 across another call. In addition, for those aggregates for which
968 hard_function_value generates a PARALLEL, we'll abort during normal
969 expansion of structure assignments; there's special code in expand_return
970 to handle this case that does not exist in expand_expr. */
972 || aggregate_value_p (result_decl, TREE_TYPE (current_function_decl)))
973 result = result_decl;
974 else if (gimplify_ctxp->return_temp)
975 result = gimplify_ctxp->return_temp;
978 result = create_tmp_var (TREE_TYPE (result_decl), NULL);
980 /* ??? With complex control flow (usually involving abnormal edges),
981 we can wind up warning about an uninitialized value for this. Due
982 to how this variable is constructed and initialized, this is never
983 true. Give up and never warn. */
984 TREE_NO_WARNING (result) = 1;
986 gimplify_ctxp->return_temp = result;
989 /* Smash the lhs of the MODIFY_EXPR to the temporary we plan to use.
990 Then gimplify the whole thing. */
991 if (result != result_decl)
992 TREE_OPERAND (ret_expr, 0) = result;
994 gimplify_and_add (TREE_OPERAND (stmt, 0), pre_p);
996 /* If we didn't use a temporary, then the result is just the result_decl.
997 Otherwise we need a simple copy. This should already be gimple. */
998 if (result == result_decl)
1001 ret_expr = build (MODIFY_EXPR, TREE_TYPE (result), result_decl, result);
1002 TREE_OPERAND (stmt, 0) = ret_expr;
1007 /* Gimplifies a DECL_EXPR node *STMT_P by making any necessary allocation
1008 and initialization explicit. */
1010 static enum gimplify_status
1011 gimplify_decl_expr (tree *stmt_p)
1013 tree stmt = *stmt_p;
1014 tree decl = DECL_EXPR_DECL (stmt);
1016 *stmt_p = NULL_TREE;
1018 if (TREE_TYPE (decl) == error_mark_node)
1021 else if (TREE_CODE (decl) == TYPE_DECL)
1022 gimplify_type_sizes (TREE_TYPE (decl), stmt_p);
1024 else if (TREE_CODE (decl) == VAR_DECL && !DECL_EXTERNAL (decl))
1026 tree init = DECL_INITIAL (decl);
1028 if (!TREE_CONSTANT (DECL_SIZE (decl)))
1030 /* This is a variable-sized decl. Simplify its size and mark it
1031 for deferred expansion. Note that mudflap depends on the format
1032 of the emitted code: see mx_register_decls(). */
1035 gimplify_type_sizes (TREE_TYPE (decl), stmt_p);
1036 gimplify_one_sizepos (&DECL_SIZE (decl), stmt_p);
1037 gimplify_one_sizepos (&DECL_SIZE_UNIT (decl), stmt_p);
1039 args = tree_cons (NULL, DECL_SIZE_UNIT (decl), NULL);
1040 t = build_fold_addr_expr (decl);
1041 args = tree_cons (NULL, t, args);
1042 t = implicit_built_in_decls[BUILT_IN_STACK_ALLOC];
1043 t = build_function_call_expr (t, args);
1045 gimplify_and_add (t, stmt_p);
1046 DECL_DEFER_OUTPUT (decl) = 1;
1049 if (init && init != error_mark_node)
1051 if (!TREE_STATIC (decl))
1053 DECL_INITIAL (decl) = NULL_TREE;
1054 init = build (MODIFY_EXPR, void_type_node, decl, init);
1055 gimplify_and_add (init, stmt_p);
1058 /* We must still examine initializers for static variables
1059 as they may contain a label address. */
1060 walk_tree (&init, force_labels_r, NULL, NULL);
1063 /* This decl isn't mentioned in the enclosing block, so add it to the
1064 list of temps. FIXME it seems a bit of a kludge to say that
1065 anonymous artificial vars aren't pushed, but everything else is. */
1066 if (DECL_ARTIFICIAL (decl) && DECL_NAME (decl) == NULL_TREE)
1067 gimple_add_tmp_var (decl);
1073 /* Gimplify a LOOP_EXPR. Normally this just involves gimplifying the body
1074 and replacing the LOOP_EXPR with goto, but if the loop contains an
1075 EXIT_EXPR, we need to append a label for it to jump to. */
1077 static enum gimplify_status
1078 gimplify_loop_expr (tree *expr_p, tree *pre_p)
1080 tree saved_label = gimplify_ctxp->exit_label;
1081 tree start_label = build1 (LABEL_EXPR, void_type_node, NULL_TREE);
1082 tree jump_stmt = build_and_jump (&LABEL_EXPR_LABEL (start_label));
1084 append_to_statement_list (start_label, pre_p);
1086 gimplify_ctxp->exit_label = NULL_TREE;
1088 gimplify_and_add (LOOP_EXPR_BODY (*expr_p), pre_p);
1090 if (gimplify_ctxp->exit_label)
1092 append_to_statement_list (jump_stmt, pre_p);
1093 *expr_p = build1 (LABEL_EXPR, void_type_node, gimplify_ctxp->exit_label);
1096 *expr_p = jump_stmt;
1098 gimplify_ctxp->exit_label = saved_label;
1103 /* Compare two case labels. Because the front end should already have
1104 made sure that case ranges do not overlap, it is enough to only compare
1105 the CASE_LOW values of each case label. */
1108 compare_case_labels (const void *p1, const void *p2)
1110 tree case1 = *(tree *)p1;
1111 tree case2 = *(tree *)p2;
1113 return tree_int_cst_compare (CASE_LOW (case1), CASE_LOW (case2));
1116 /* Sort the case labels in LABEL_VEC in ascending order. */
1119 sort_case_labels (tree label_vec)
1121 size_t len = TREE_VEC_LENGTH (label_vec);
1122 tree default_case = TREE_VEC_ELT (label_vec, len - 1);
1124 if (CASE_LOW (default_case))
1128 /* The last label in the vector should be the default case
1130 for (i = 0; i < len; ++i)
1132 tree t = TREE_VEC_ELT (label_vec, i);
1136 TREE_VEC_ELT (label_vec, i) = TREE_VEC_ELT (label_vec, len - 1);
1137 TREE_VEC_ELT (label_vec, len - 1) = default_case;
1143 qsort (&TREE_VEC_ELT (label_vec, 0), len - 1, sizeof (tree),
1144 compare_case_labels);
1147 /* Gimplify a SWITCH_EXPR, and collect a TREE_VEC of the labels it can
1150 static enum gimplify_status
1151 gimplify_switch_expr (tree *expr_p, tree *pre_p)
1153 tree switch_expr = *expr_p;
1154 enum gimplify_status ret;
1156 ret = gimplify_expr (&SWITCH_COND (switch_expr), pre_p, NULL,
1157 is_gimple_val, fb_rvalue);
1159 if (SWITCH_BODY (switch_expr))
1161 varray_type labels, saved_labels;
1162 tree label_vec, default_case = NULL_TREE;
1165 /* If someone can be bothered to fill in the labels, they can
1166 be bothered to null out the body too. */
1167 if (SWITCH_LABELS (switch_expr))
1170 saved_labels = gimplify_ctxp->case_labels;
1171 VARRAY_TREE_INIT (gimplify_ctxp->case_labels, 8, "case_labels");
1173 gimplify_to_stmt_list (&SWITCH_BODY (switch_expr));
1175 labels = gimplify_ctxp->case_labels;
1176 gimplify_ctxp->case_labels = saved_labels;
1178 len = VARRAY_ACTIVE_SIZE (labels);
1180 for (i = 0; i < len; ++i)
1182 tree t = VARRAY_TREE (labels, i);
1185 /* The default case must be the last label in the list. */
1187 VARRAY_TREE (labels, i) = VARRAY_TREE (labels, len - 1);
1193 label_vec = make_tree_vec (len + 1);
1194 SWITCH_LABELS (*expr_p) = label_vec;
1195 append_to_statement_list (switch_expr, pre_p);
1199 /* If the switch has no default label, add one, so that we jump
1200 around the switch body. */
1201 default_case = build (CASE_LABEL_EXPR, void_type_node, NULL_TREE,
1202 NULL_TREE, create_artificial_label ());
1203 append_to_statement_list (SWITCH_BODY (switch_expr), pre_p);
1204 *expr_p = build (LABEL_EXPR, void_type_node,
1205 CASE_LABEL (default_case));
1208 *expr_p = SWITCH_BODY (switch_expr);
1210 for (i = 0; i < len; ++i)
1211 TREE_VEC_ELT (label_vec, i) = VARRAY_TREE (labels, i);
1212 TREE_VEC_ELT (label_vec, len) = default_case;
1214 sort_case_labels (label_vec);
1216 SWITCH_BODY (switch_expr) = NULL;
1218 else if (!SWITCH_LABELS (switch_expr))
1224 static enum gimplify_status
1225 gimplify_case_label_expr (tree *expr_p)
1227 tree expr = *expr_p;
1228 if (gimplify_ctxp->case_labels)
1229 VARRAY_PUSH_TREE (gimplify_ctxp->case_labels, expr);
1232 *expr_p = build (LABEL_EXPR, void_type_node, CASE_LABEL (expr));
1236 /* Gimplify a LABELED_BLOCK_EXPR into a LABEL_EXPR following
1237 a (possibly empty) body. */
1239 static enum gimplify_status
1240 gimplify_labeled_block_expr (tree *expr_p)
1242 tree body = LABELED_BLOCK_BODY (*expr_p);
1243 tree label = LABELED_BLOCK_LABEL (*expr_p);
1246 DECL_CONTEXT (label) = current_function_decl;
1247 t = build (LABEL_EXPR, void_type_node, label);
1248 if (body != NULL_TREE)
1249 t = build (COMPOUND_EXPR, void_type_node, body, t);
1255 /* Gimplify a EXIT_BLOCK_EXPR into a GOTO_EXPR. */
1257 static enum gimplify_status
1258 gimplify_exit_block_expr (tree *expr_p)
1260 tree labeled_block = TREE_OPERAND (*expr_p, 0);
1263 /* First operand must be a LABELED_BLOCK_EXPR, which should
1264 already be lowered (or partially lowered) when we get here. */
1265 #if defined ENABLE_CHECKING
1266 if (TREE_CODE (labeled_block) != LABELED_BLOCK_EXPR)
1270 label = LABELED_BLOCK_LABEL (labeled_block);
1271 *expr_p = build1 (GOTO_EXPR, void_type_node, label);
1276 /* Build a GOTO to the LABEL_DECL pointed to by LABEL_P, building it first
1280 build_and_jump (tree *label_p)
1282 if (label_p == NULL)
1283 /* If there's nowhere to jump, just fall through. */
1286 if (*label_p == NULL_TREE)
1288 tree label = create_artificial_label ();
1292 return build1 (GOTO_EXPR, void_type_node, *label_p);
1295 /* Gimplify an EXIT_EXPR by converting to a GOTO_EXPR inside a COND_EXPR.
1296 This also involves building a label to jump to and communicating it to
1297 gimplify_loop_expr through gimplify_ctxp->exit_label. */
1299 static enum gimplify_status
1300 gimplify_exit_expr (tree *expr_p)
1302 tree cond = TREE_OPERAND (*expr_p, 0);
1305 expr = build_and_jump (&gimplify_ctxp->exit_label);
1306 expr = build (COND_EXPR, void_type_node, cond, expr, NULL_TREE);
1312 /* A helper function to be called via walk_tree. Mark all labels under *TP
1313 as being forced. To be called for DECL_INITIAL of static variables. */
1316 force_labels_r (tree *tp, int *walk_subtrees, void *data ATTRIBUTE_UNUSED)
1320 if (TREE_CODE (*tp) == LABEL_DECL)
1321 FORCED_LABEL (*tp) = 1;
1326 /* *EXPR_P is a COMPONENT_REF being used as an rvalue. If its type is
1327 different from its canonical type, wrap the whole thing inside a
1328 NOP_EXPR and force the type of the COMPONENT_REF to be the canonical
1331 The canonical type of a COMPONENT_REF is the type of the field being
1332 referenced--unless the field is a bit-field which can be read directly
1333 in a smaller mode, in which case the canonical type is the
1334 sign-appropriate type corresponding to that mode. */
1337 canonicalize_component_ref (tree *expr_p)
1339 tree expr = *expr_p;
1342 if (TREE_CODE (expr) != COMPONENT_REF)
1345 if (INTEGRAL_TYPE_P (TREE_TYPE (expr)))
1346 type = TREE_TYPE (get_unwidened (expr, NULL_TREE));
1348 type = TREE_TYPE (TREE_OPERAND (expr, 1));
1350 if (TREE_TYPE (expr) != type)
1352 tree old_type = TREE_TYPE (expr);
1354 /* Set the type of the COMPONENT_REF to the underlying type. */
1355 TREE_TYPE (expr) = type;
1357 /* And wrap the whole thing inside a NOP_EXPR. */
1358 expr = build1 (NOP_EXPR, old_type, expr);
1364 /* If a NOP conversion is changing a pointer to array of foo to a pointer
1365 to foo, embed that change in the ADDR_EXPR by converting
1370 where L is the lower bound. For simplicity, only do this for constant
1374 canonicalize_addr_expr (tree *expr_p)
1376 tree expr = *expr_p;
1377 tree ctype = TREE_TYPE (expr);
1378 tree addr_expr = TREE_OPERAND (expr, 0);
1379 tree atype = TREE_TYPE (addr_expr);
1380 tree dctype, datype, ddatype, otype, obj_expr;
1382 /* Both cast and addr_expr types should be pointers. */
1383 if (!POINTER_TYPE_P (ctype) || !POINTER_TYPE_P (atype))
1386 /* The addr_expr type should be a pointer to an array. */
1387 datype = TREE_TYPE (atype);
1388 if (TREE_CODE (datype) != ARRAY_TYPE)
1391 /* Both cast and addr_expr types should address the same object type. */
1392 dctype = TREE_TYPE (ctype);
1393 ddatype = TREE_TYPE (datype);
1394 if (!lang_hooks.types_compatible_p (ddatype, dctype))
1397 /* The addr_expr and the object type should match. */
1398 obj_expr = TREE_OPERAND (addr_expr, 0);
1399 otype = TREE_TYPE (obj_expr);
1400 if (!lang_hooks.types_compatible_p (otype, datype))
1403 /* The lower bound and element sizes must be constant. */
1404 if (TREE_CODE (TYPE_SIZE_UNIT (dctype)) != INTEGER_CST
1405 || !TYPE_DOMAIN (datype) || !TYPE_MIN_VALUE (TYPE_DOMAIN (datype))
1406 || TREE_CODE (TYPE_MIN_VALUE (TYPE_DOMAIN (datype))) != INTEGER_CST)
1409 /* All checks succeeded. Build a new node to merge the cast. */
1410 *expr_p = build4 (ARRAY_REF, dctype, obj_expr,
1411 TYPE_MIN_VALUE (TYPE_DOMAIN (datype)),
1412 TYPE_MIN_VALUE (TYPE_DOMAIN (datype)),
1413 size_binop (EXACT_DIV_EXPR, TYPE_SIZE_UNIT (dctype),
1414 size_int (TYPE_ALIGN (dctype)
1416 *expr_p = build1 (ADDR_EXPR, ctype, *expr_p);
1419 /* *EXPR_P is a NOP_EXPR or CONVERT_EXPR. Remove it and/or other conversions
1420 underneath as appropriate. */
1422 static enum gimplify_status
1423 gimplify_conversion (tree *expr_p)
1425 /* If we still have a conversion at the toplevel, then strip
1426 away all but the outermost conversion. */
1427 if (TREE_CODE (*expr_p) == NOP_EXPR || TREE_CODE (*expr_p) == CONVERT_EXPR)
1429 STRIP_SIGN_NOPS (TREE_OPERAND (*expr_p, 0));
1431 /* And remove the outermost conversion if it's useless. */
1432 if (tree_ssa_useless_type_conversion (*expr_p))
1433 *expr_p = TREE_OPERAND (*expr_p, 0);
1436 /* If we still have a conversion at the toplevel,
1437 then canonicalize some constructs. */
1438 if (TREE_CODE (*expr_p) == NOP_EXPR || TREE_CODE (*expr_p) == CONVERT_EXPR)
1440 tree sub = TREE_OPERAND (*expr_p, 0);
1442 /* If a NOP conversion is changing the type of a COMPONENT_REF
1443 expression, then canonicalize its type now in order to expose more
1444 redundant conversions. */
1445 if (TREE_CODE (sub) == COMPONENT_REF)
1446 canonicalize_component_ref (&TREE_OPERAND (*expr_p, 0));
1448 /* If a NOP conversion is changing a pointer to array of foo
1449 to a pointer to foo, embed that change in the ADDR_EXPR. */
1450 else if (TREE_CODE (sub) == ADDR_EXPR)
1451 canonicalize_addr_expr (expr_p);
1457 /* Reduce MIN/MAX_EXPR to a COND_EXPR for further gimplification. */
1459 static enum gimplify_status
1460 gimplify_minimax_expr (tree *expr_p, tree *pre_p, tree *post_p)
1462 tree op1 = TREE_OPERAND (*expr_p, 0);
1463 tree op2 = TREE_OPERAND (*expr_p, 1);
1464 enum tree_code code;
1465 enum gimplify_status r0, r1;
1467 if (TREE_CODE (*expr_p) == MIN_EXPR)
1472 r0 = gimplify_expr (&op1, pre_p, post_p, is_gimple_val, fb_rvalue);
1473 r1 = gimplify_expr (&op2, pre_p, post_p, is_gimple_val, fb_rvalue);
1475 *expr_p = build (COND_EXPR, TREE_TYPE (*expr_p),
1476 build (code, boolean_type_node, op1, op2),
1479 if (r0 == GS_ERROR || r1 == GS_ERROR)
1485 /* Subroutine of gimplify_compound_lval.
1486 Converts an ARRAY_REF to the equivalent *(&array + offset) form. */
1488 static enum gimplify_status
1489 gimplify_array_ref_to_plus (tree *expr_p, tree *pre_p, tree *post_p)
1491 tree array = TREE_OPERAND (*expr_p, 0);
1492 tree arrtype = TREE_TYPE (array);
1493 tree elttype = TREE_TYPE (arrtype);
1494 tree size = array_ref_element_size (*expr_p);
1495 tree ptrtype = build_pointer_type (elttype);
1496 enum tree_code add_code = PLUS_EXPR;
1497 tree idx = TREE_OPERAND (*expr_p, 1);
1498 tree minidx = unshare_expr (array_ref_low_bound (*expr_p));
1499 tree offset, addr, result;
1500 enum gimplify_status ret;
1502 /* If the array domain does not start at zero, apply the offset. */
1503 if (!integer_zerop (minidx))
1505 idx = convert (TREE_TYPE (minidx), idx);
1506 idx = fold (build (MINUS_EXPR, TREE_TYPE (minidx), idx, minidx));
1509 /* If the index is negative -- a technically invalid situation now
1510 that we've biased the index back to zero -- then casting it to
1511 unsigned has ill effects. In particular, -1*4U/4U != -1.
1512 Represent this as a subtraction of a positive rather than addition
1513 of a negative. This will prevent any conversion back to ARRAY_REF
1514 from getting the wrong results from the division. */
1515 if (TREE_CODE (idx) == INTEGER_CST && tree_int_cst_sgn (idx) < 0)
1517 idx = fold (build1 (NEGATE_EXPR, TREE_TYPE (idx), idx));
1518 add_code = MINUS_EXPR;
1521 /* Pointer arithmetic must be done in sizetype. */
1522 idx = fold_convert (sizetype, idx);
1524 /* Convert the index to a byte offset. */
1525 offset = size_binop (MULT_EXPR, size, idx);
1527 ret = gimplify_expr (&array, pre_p, post_p, is_gimple_min_lval, fb_lvalue);
1528 if (ret == GS_ERROR)
1531 addr = build_fold_addr_expr_with_type (array, ptrtype);
1532 result = fold (build (add_code, ptrtype, addr, offset));
1533 *expr_p = build1 (INDIRECT_REF, elttype, result);
1538 /* Gimplify the COMPONENT_REF, ARRAY_REF, REALPART_EXPR or IMAGPART_EXPR
1539 node pointed by EXPR_P.
1542 : min_lval '[' val ']'
1544 | compound_lval '[' val ']'
1545 | compound_lval '.' ID
1547 This is not part of the original SIMPLE definition, which separates
1548 array and member references, but it seems reasonable to handle them
1549 together. Also, this way we don't run into problems with union
1550 aliasing; gcc requires that for accesses through a union to alias, the
1551 union reference must be explicit, which was not always the case when we
1552 were splitting up array and member refs.
1554 PRE_P points to the list where side effects that must happen before
1555 *EXPR_P should be stored.
1557 POST_P points to the list where side effects that must happen after
1558 *EXPR_P should be stored. */
1560 static enum gimplify_status
1561 gimplify_compound_lval (tree *expr_p, tree *pre_p,
1562 tree *post_p, fallback_t fallback)
1566 enum gimplify_status ret = GS_OK, tret;
1569 #if defined ENABLE_CHECKING
1570 if (TREE_CODE (*expr_p) != ARRAY_REF
1571 && TREE_CODE (*expr_p) != ARRAY_RANGE_REF
1572 && TREE_CODE (*expr_p) != COMPONENT_REF
1573 && TREE_CODE (*expr_p) != BIT_FIELD_REF
1574 && TREE_CODE (*expr_p) != REALPART_EXPR
1575 && TREE_CODE (*expr_p) != IMAGPART_EXPR)
1579 /* Create a stack of the subexpressions so later we can walk them in
1580 order from inner to outer. */
1581 VARRAY_TREE_INIT (stack, 10, "stack");
1583 /* We can either handle REALPART_EXPR, IMAGEPART_EXPR anything that
1584 handled_components can deal with. */
1586 (handled_component_p (*p)
1587 || TREE_CODE (*p) == REALPART_EXPR || TREE_CODE (*p) == IMAGPART_EXPR);
1588 p = &TREE_OPERAND (*p, 0))
1589 VARRAY_PUSH_TREE (stack, *p);
1591 /* Now STACK is a stack of pointers to all the refs we've walked through
1592 and P points to the innermost expression.
1594 Java requires that we elaborated nodes in source order. That
1595 means we must gimplify the inner expression followed by each of
1596 the indices, in order. But we can't gimplify the inner
1597 expression until we deal with any variable bounds, sizes, or
1598 positions in order to deal with PLACEHOLDER_EXPRs.
1600 So we do this in three steps. First we deal with the annotations
1601 for any variables in the components, then we gimplify the base,
1602 then we gimplify any indices, from left to right. */
1603 for (i = VARRAY_ACTIVE_SIZE (stack) - 1; i >= 0; i--)
1605 tree t = VARRAY_TREE (stack, i);
1607 if (TREE_CODE (t) == ARRAY_REF || TREE_CODE (t) == ARRAY_RANGE_REF)
1609 /* Gimplify the low bound and element type size and put them into
1610 the ARRAY_REF. If these values are set, they have already been
1612 if (!TREE_OPERAND (t, 2))
1614 tree low = unshare_expr (array_ref_low_bound (t));
1615 if (!is_gimple_min_invariant (low))
1617 TREE_OPERAND (t, 2) = low;
1618 tret = gimplify_expr (&TREE_OPERAND (t, 2), pre_p, post_p,
1619 is_gimple_tmp_var, fb_rvalue);
1620 ret = MIN (ret, tret);
1624 if (!TREE_OPERAND (t, 3))
1626 tree elmt_type = TREE_TYPE (TREE_TYPE (TREE_OPERAND (t, 0)));
1627 tree elmt_size = unshare_expr (array_ref_element_size (t));
1628 tree factor = size_int (TYPE_ALIGN (elmt_type) / BITS_PER_UNIT);
1630 /* Divide the element size by the alignment of the element
1632 elmt_size = size_binop (EXACT_DIV_EXPR, elmt_size, factor);
1634 if (!is_gimple_min_invariant (elmt_size))
1636 TREE_OPERAND (t, 3) = elmt_size;
1637 tret = gimplify_expr (&TREE_OPERAND (t, 3), pre_p, post_p,
1638 is_gimple_tmp_var, fb_rvalue);
1639 ret = MIN (ret, tret);
1643 else if (TREE_CODE (t) == COMPONENT_REF)
1645 /* Set the field offset into T and gimplify it. */
1646 if (!TREE_OPERAND (t, 2))
1648 tree offset = unshare_expr (component_ref_field_offset (t));
1649 tree field = TREE_OPERAND (t, 1);
1651 = size_int (DECL_OFFSET_ALIGN (field) / BITS_PER_UNIT);
1653 /* Divide the offset by its alignment. */
1654 offset = size_binop (EXACT_DIV_EXPR, offset, factor);
1656 if (!is_gimple_min_invariant (offset))
1658 TREE_OPERAND (t, 2) = offset;
1659 tret = gimplify_expr (&TREE_OPERAND (t, 2), pre_p, post_p,
1660 is_gimple_tmp_var, fb_rvalue);
1661 ret = MIN (ret, tret);
1667 /* Step 2 is to gimplify the base expression. */
1668 tret = gimplify_expr (p, pre_p, post_p, is_gimple_min_lval, fallback);
1669 ret = MIN (ret, tret);
1671 /* And finally, the indices and operands to BIT_FIELD_REF. */
1672 for (; VARRAY_ACTIVE_SIZE (stack) > 0; )
1674 tree t = VARRAY_TOP_TREE (stack);
1676 if (TREE_CODE (t) == ARRAY_REF || TREE_CODE (t) == ARRAY_RANGE_REF)
1678 /* Gimplify the dimension.
1679 Temporary fix for gcc.c-torture/execute/20040313-1.c.
1680 Gimplify non-constant array indices into a temporary
1682 FIXME - The real fix is to gimplify post-modify
1683 expressions into a minimal gimple lvalue. However, that
1684 exposes bugs in alias analysis. The alias analyzer does
1685 not handle &PTR->FIELD very well. Will fix after the
1686 branch is merged into mainline (dnovillo 2004-05-03). */
1687 if (!is_gimple_min_invariant (TREE_OPERAND (t, 1)))
1689 tret = gimplify_expr (&TREE_OPERAND (t, 1), pre_p, post_p,
1690 is_gimple_tmp_var, fb_rvalue);
1691 ret = MIN (ret, tret);
1694 else if (TREE_CODE (t) == BIT_FIELD_REF)
1696 tret = gimplify_expr (&TREE_OPERAND (t, 1), pre_p, post_p,
1697 is_gimple_val, fb_rvalue);
1698 ret = MIN (ret, tret);
1699 tret = gimplify_expr (&TREE_OPERAND (t, 2), pre_p, post_p,
1700 is_gimple_val, fb_rvalue);
1701 ret = MIN (ret, tret);
1704 /* The innermost expression P may have originally had TREE_SIDE_EFFECTS
1705 set which would have caused all the outer expressions in EXPR_P
1706 leading to P to also have had TREE_SIDE_EFFECTS set. */
1707 recalculate_side_effects (t);
1711 tret = gimplify_expr (p, pre_p, post_p, is_gimple_min_lval, fallback);
1712 ret = MIN (ret, tret);
1714 /* If the outermost expression is a COMPONENT_REF, canonicalize its type. */
1715 if ((fallback & fb_rvalue) && TREE_CODE (*expr_p) == COMPONENT_REF)
1717 canonicalize_component_ref (expr_p);
1718 ret = MIN (ret, GS_OK);
1724 /* Gimplify the self modifying expression pointed by EXPR_P (++, --, +=, -=).
1726 PRE_P points to the list where side effects that must happen before
1727 *EXPR_P should be stored.
1729 POST_P points to the list where side effects that must happen after
1730 *EXPR_P should be stored.
1732 WANT_VALUE is nonzero iff we want to use the value of this expression
1733 in another expression. */
1735 static enum gimplify_status
1736 gimplify_self_mod_expr (tree *expr_p, tree *pre_p, tree *post_p,
1739 enum tree_code code;
1740 tree lhs, lvalue, rhs, t1;
1742 enum tree_code arith_code;
1743 enum gimplify_status ret;
1745 code = TREE_CODE (*expr_p);
1747 #if defined ENABLE_CHECKING
1748 if (code != POSTINCREMENT_EXPR
1749 && code != POSTDECREMENT_EXPR
1750 && code != PREINCREMENT_EXPR
1751 && code != PREDECREMENT_EXPR)
1755 /* Prefix or postfix? */
1756 if (code == POSTINCREMENT_EXPR || code == POSTDECREMENT_EXPR)
1757 /* Faster to treat as prefix if result is not used. */
1758 postfix = want_value;
1762 /* Add or subtract? */
1763 if (code == PREINCREMENT_EXPR || code == POSTINCREMENT_EXPR)
1764 arith_code = PLUS_EXPR;
1766 arith_code = MINUS_EXPR;
1768 /* Gimplify the LHS into a GIMPLE lvalue. */
1769 lvalue = TREE_OPERAND (*expr_p, 0);
1770 ret = gimplify_expr (&lvalue, pre_p, post_p, is_gimple_lvalue, fb_lvalue);
1771 if (ret == GS_ERROR)
1774 /* Extract the operands to the arithmetic operation. */
1776 rhs = TREE_OPERAND (*expr_p, 1);
1778 /* For postfix operator, we evaluate the LHS to an rvalue and then use
1779 that as the result value and in the postqueue operation. */
1782 ret = gimplify_expr (&lhs, pre_p, post_p, is_gimple_val, fb_rvalue);
1783 if (ret == GS_ERROR)
1787 t1 = build (arith_code, TREE_TYPE (*expr_p), lhs, rhs);
1788 t1 = build (MODIFY_EXPR, TREE_TYPE (lvalue), lvalue, t1);
1792 gimplify_and_add (t1, post_p);
1803 /* Gimplify the CALL_EXPR node pointed by EXPR_P. PRE_P points to the
1804 list where side effects that must happen before *EXPR_P should be stored.
1805 WANT_VALUE is true if the result of the call is desired. */
1807 static enum gimplify_status
1808 gimplify_call_expr (tree *expr_p, tree *pre_p, bool want_value)
1812 enum gimplify_status ret;
1814 #if defined ENABLE_CHECKING
1815 if (TREE_CODE (*expr_p) != CALL_EXPR)
1819 /* For reliable diagnostics during inlining, it is necessary that
1820 every call_expr be annotated with file and line. */
1821 if (! EXPR_HAS_LOCATION (*expr_p))
1822 SET_EXPR_LOCATION (*expr_p, input_location);
1824 /* This may be a call to a builtin function.
1826 Builtin function calls may be transformed into different
1827 (and more efficient) builtin function calls under certain
1828 circumstances. Unfortunately, gimplification can muck things
1829 up enough that the builtin expanders are not aware that certain
1830 transformations are still valid.
1832 So we attempt transformation/gimplification of the call before
1833 we gimplify the CALL_EXPR. At this time we do not manage to
1834 transform all calls in the same manner as the expanders do, but
1835 we do transform most of them. */
1836 decl = get_callee_fndecl (*expr_p);
1837 if (decl && DECL_BUILT_IN (decl))
1841 /* If it is allocation of stack, record the need to restore the memory
1842 when the enclosing bind_expr is exited. */
1843 if (DECL_FUNCTION_CODE (decl) == BUILT_IN_STACK_ALLOC)
1844 gimplify_ctxp->save_stack = true;
1846 /* If it is restore of the stack, reset it, since it means we are
1847 regimplifying the bind_expr. Note that we use the fact that
1848 for try_finally_expr, try part is processed first. */
1849 if (DECL_FUNCTION_CODE (decl) == BUILT_IN_STACK_RESTORE)
1850 gimplify_ctxp->save_stack = false;
1852 new = simplify_builtin (*expr_p, !want_value);
1854 if (new && new != *expr_p)
1856 /* There was a transformation of this call which computes the
1857 same value, but in a more efficient way. Return and try
1864 /* There is a sequence point before the call, so any side effects in
1865 the calling expression must occur before the actual call. Force
1866 gimplify_expr to use an internal post queue. */
1867 ret = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p, NULL,
1868 is_gimple_call_addr, fb_rvalue);
1870 if (PUSH_ARGS_REVERSED)
1871 TREE_OPERAND (*expr_p, 1) = nreverse (TREE_OPERAND (*expr_p, 1));
1872 for (arglist = TREE_OPERAND (*expr_p, 1); arglist;
1873 arglist = TREE_CHAIN (arglist))
1875 enum gimplify_status t;
1876 bool (*test) (tree);
1879 /* In general, we allow lvalues for function arguments to avoid
1880 extra overhead of copying large aggregates out of even larger
1881 aggregates into temporaries only to copy the temporaries to
1882 the argument list. Make optimizers happy by pulling out to
1883 temporaries those types that fit in registers. */
1884 if (is_gimple_reg_type (TREE_TYPE (TREE_VALUE (arglist))))
1885 test = is_gimple_val, fb = fb_rvalue;
1887 test = is_gimple_lvalue, fb = fb_either;
1889 /* There is a sequence point before a function call. Side effects in
1890 the argument list must occur before the actual call. So, when
1891 gimplifying arguments, force gimplify_expr to use an internal
1892 post queue which is then appended to the end of PRE_P. */
1893 t = gimplify_expr (&TREE_VALUE (arglist), pre_p, NULL, test, fb);
1898 if (PUSH_ARGS_REVERSED)
1899 TREE_OPERAND (*expr_p, 1) = nreverse (TREE_OPERAND (*expr_p, 1));
1901 /* Try this again in case gimplification exposed something. */
1902 if (ret != GS_ERROR && decl && DECL_BUILT_IN (decl))
1904 tree new = simplify_builtin (*expr_p, !want_value);
1906 if (new && new != *expr_p)
1908 /* There was a transformation of this call which computes the
1909 same value, but in a more efficient way. Return and try
1916 /* If the function is "const" or "pure", then clear TREE_SIDE_EFFECTS on its
1917 decl. This allows us to eliminate redundant or useless
1918 calls to "const" functions. */
1919 if (TREE_CODE (*expr_p) == CALL_EXPR
1920 && (call_expr_flags (*expr_p) & (ECF_CONST | ECF_PURE)))
1921 TREE_SIDE_EFFECTS (*expr_p) = 0;
1926 /* Handle shortcut semantics in the predicate operand of a COND_EXPR by
1927 rewriting it into multiple COND_EXPRs, and possibly GOTO_EXPRs.
1929 TRUE_LABEL_P and FALSE_LABEL_P point to the labels to jump to if the
1930 condition is true or false, respectively. If null, we should generate
1931 our own to skip over the evaluation of this specific expression.
1933 This function is the tree equivalent of do_jump.
1935 shortcut_cond_r should only be called by shortcut_cond_expr. */
1938 shortcut_cond_r (tree pred, tree *true_label_p, tree *false_label_p)
1940 tree local_label = NULL_TREE;
1941 tree t, expr = NULL;
1943 /* OK, it's not a simple case; we need to pull apart the COND_EXPR to
1944 retain the shortcut semantics. Just insert the gotos here;
1945 shortcut_cond_expr will append the real blocks later. */
1946 if (TREE_CODE (pred) == TRUTH_ANDIF_EXPR)
1948 /* Turn if (a && b) into
1950 if (a); else goto no;
1951 if (b) goto yes; else goto no;
1954 if (false_label_p == NULL)
1955 false_label_p = &local_label;
1957 t = shortcut_cond_r (TREE_OPERAND (pred, 0), NULL, false_label_p);
1958 append_to_statement_list (t, &expr);
1960 t = shortcut_cond_r (TREE_OPERAND (pred, 1), true_label_p,
1962 append_to_statement_list (t, &expr);
1964 else if (TREE_CODE (pred) == TRUTH_ORIF_EXPR)
1966 /* Turn if (a || b) into
1969 if (b) goto yes; else goto no;
1972 if (true_label_p == NULL)
1973 true_label_p = &local_label;
1975 t = shortcut_cond_r (TREE_OPERAND (pred, 0), true_label_p, NULL);
1976 append_to_statement_list (t, &expr);
1978 t = shortcut_cond_r (TREE_OPERAND (pred, 1), true_label_p,
1980 append_to_statement_list (t, &expr);
1982 else if (TREE_CODE (pred) == COND_EXPR)
1984 /* As long as we're messing with gotos, turn if (a ? b : c) into
1986 if (b) goto yes; else goto no;
1988 if (c) goto yes; else goto no; */
1989 expr = build (COND_EXPR, void_type_node, TREE_OPERAND (pred, 0),
1990 shortcut_cond_r (TREE_OPERAND (pred, 1), true_label_p,
1992 shortcut_cond_r (TREE_OPERAND (pred, 2), true_label_p,
1997 expr = build (COND_EXPR, void_type_node, pred,
1998 build_and_jump (true_label_p),
1999 build_and_jump (false_label_p));
2004 t = build1 (LABEL_EXPR, void_type_node, local_label);
2005 append_to_statement_list (t, &expr);
2012 shortcut_cond_expr (tree expr)
2014 tree pred = TREE_OPERAND (expr, 0);
2015 tree then_ = TREE_OPERAND (expr, 1);
2016 tree else_ = TREE_OPERAND (expr, 2);
2017 tree true_label, false_label, end_label, t;
2019 tree *false_label_p;
2020 bool emit_end, emit_false;
2021 bool then_se = then_ && TREE_SIDE_EFFECTS (then_);
2022 bool else_se = else_ && TREE_SIDE_EFFECTS (else_);
2024 /* First do simple transformations. */
2027 /* If there is no 'else', turn (a && b) into if (a) if (b). */
2028 while (TREE_CODE (pred) == TRUTH_ANDIF_EXPR)
2030 TREE_OPERAND (expr, 0) = TREE_OPERAND (pred, 1);
2031 then_ = shortcut_cond_expr (expr);
2032 pred = TREE_OPERAND (pred, 0);
2033 expr = build (COND_EXPR, void_type_node, pred, then_, NULL_TREE);
2038 /* If there is no 'then', turn
2041 if (a); else if (b); else d. */
2042 while (TREE_CODE (pred) == TRUTH_ORIF_EXPR)
2044 TREE_OPERAND (expr, 0) = TREE_OPERAND (pred, 1);
2045 else_ = shortcut_cond_expr (expr);
2046 pred = TREE_OPERAND (pred, 0);
2047 expr = build (COND_EXPR, void_type_node, pred, NULL_TREE, else_);
2051 /* If we're done, great. */
2052 if (TREE_CODE (pred) != TRUTH_ANDIF_EXPR
2053 && TREE_CODE (pred) != TRUTH_ORIF_EXPR)
2056 /* Otherwise we need to mess with gotos. Change
2059 if (a); else goto no;
2062 and recursively gimplify the condition. */
2064 true_label = false_label = end_label = NULL_TREE;
2066 /* If our arms just jump somewhere, hijack those labels so we don't
2067 generate jumps to jumps. */
2070 && TREE_CODE (then_) == GOTO_EXPR
2071 && TREE_CODE (GOTO_DESTINATION (then_)) == LABEL_DECL)
2073 true_label = GOTO_DESTINATION (then_);
2079 && TREE_CODE (else_) == GOTO_EXPR
2080 && TREE_CODE (GOTO_DESTINATION (else_)) == LABEL_DECL)
2082 false_label = GOTO_DESTINATION (else_);
2087 /* If we aren't hijacking a label for the 'then' branch, it falls through. */
2089 true_label_p = &true_label;
2091 true_label_p = NULL;
2093 /* The 'else' branch also needs a label if it contains interesting code. */
2094 if (false_label || else_se)
2095 false_label_p = &false_label;
2097 false_label_p = NULL;
2099 /* If there was nothing else in our arms, just forward the label(s). */
2100 if (!then_se && !else_se)
2101 return shortcut_cond_r (pred, true_label_p, false_label_p);
2103 /* If our last subexpression already has a terminal label, reuse it. */
2105 expr = expr_last (else_);
2107 expr = expr_last (then_);
2110 if (expr && TREE_CODE (expr) == LABEL_EXPR)
2111 end_label = LABEL_EXPR_LABEL (expr);
2113 /* If we don't care about jumping to the 'else' branch, jump to the end
2114 if the condition is false. */
2116 false_label_p = &end_label;
2118 /* We only want to emit these labels if we aren't hijacking them. */
2119 emit_end = (end_label == NULL_TREE);
2120 emit_false = (false_label == NULL_TREE);
2122 pred = shortcut_cond_r (pred, true_label_p, false_label_p);
2125 append_to_statement_list (pred, &expr);
2127 append_to_statement_list (then_, &expr);
2130 t = build_and_jump (&end_label);
2131 append_to_statement_list (t, &expr);
2134 t = build1 (LABEL_EXPR, void_type_node, false_label);
2135 append_to_statement_list (t, &expr);
2137 append_to_statement_list (else_, &expr);
2139 if (emit_end && end_label)
2141 t = build1 (LABEL_EXPR, void_type_node, end_label);
2142 append_to_statement_list (t, &expr);
2148 /* EXPR is used in a boolean context; make sure it has BOOLEAN_TYPE. */
2151 gimple_boolify (tree expr)
2153 tree type = TREE_TYPE (expr);
2155 if (TREE_CODE (type) == BOOLEAN_TYPE)
2158 /* If this is the predicate of a COND_EXPR, it might not even be a
2160 expr = lang_hooks.truthvalue_conversion (expr);
2162 switch (TREE_CODE (expr))
2164 case TRUTH_AND_EXPR:
2166 case TRUTH_XOR_EXPR:
2167 case TRUTH_ANDIF_EXPR:
2168 case TRUTH_ORIF_EXPR:
2169 /* Also boolify the arguments of truth exprs. */
2170 TREE_OPERAND (expr, 1) = gimple_boolify (TREE_OPERAND (expr, 1));
2173 case TRUTH_NOT_EXPR:
2174 TREE_OPERAND (expr, 0) = gimple_boolify (TREE_OPERAND (expr, 0));
2177 case EQ_EXPR: case NE_EXPR:
2178 case LE_EXPR: case GE_EXPR: case LT_EXPR: case GT_EXPR:
2179 /* These expressions always produce boolean results. */
2180 TREE_TYPE (expr) = boolean_type_node;
2184 /* Other expressions that get here must have boolean values, but
2185 might need to be converted to the appropriate mode. */
2186 return convert (boolean_type_node, expr);
2190 /* Convert the conditional expression pointed by EXPR_P '(p) ? a : b;'
2199 The second form is used when *EXPR_P is of type void.
2201 TARGET is the tree for T1 above.
2203 PRE_P points to the list where side effects that must happen before
2204 *EXPR_P should be stored. */
2206 static enum gimplify_status
2207 gimplify_cond_expr (tree *expr_p, tree *pre_p, tree target)
2209 tree expr = *expr_p;
2211 enum gimplify_status ret;
2213 type = TREE_TYPE (expr);
2215 TREE_TYPE (expr) = void_type_node;
2217 /* If this COND_EXPR has a value, copy the values into a temporary within
2219 else if (! VOID_TYPE_P (type))
2228 tmp = create_tmp_var (TREE_TYPE (expr), "iftmp");
2232 /* Build the then clause, 't1 = a;'. But don't build an assignment
2233 if this branch is void; in C++ it can be, if it's a throw. */
2234 if (TREE_TYPE (TREE_OPERAND (expr, 1)) != void_type_node)
2235 TREE_OPERAND (expr, 1)
2236 = build (MODIFY_EXPR, void_type_node, tmp, TREE_OPERAND (expr, 1));
2238 /* Build the else clause, 't1 = b;'. */
2239 if (TREE_TYPE (TREE_OPERAND (expr, 2)) != void_type_node)
2240 TREE_OPERAND (expr, 2)
2241 = build (MODIFY_EXPR, void_type_node, tmp, TREE_OPERAND (expr, 2));
2243 TREE_TYPE (expr) = void_type_node;
2244 recalculate_side_effects (expr);
2246 /* Move the COND_EXPR to the prequeue and use the temp in its place. */
2247 gimplify_and_add (expr, pre_p);
2253 /* Make sure the condition has BOOLEAN_TYPE. */
2254 TREE_OPERAND (expr, 0) = gimple_boolify (TREE_OPERAND (expr, 0));
2256 /* Break apart && and || conditions. */
2257 if (TREE_CODE (TREE_OPERAND (expr, 0)) == TRUTH_ANDIF_EXPR
2258 || TREE_CODE (TREE_OPERAND (expr, 0)) == TRUTH_ORIF_EXPR)
2260 expr = shortcut_cond_expr (expr);
2262 if (expr != *expr_p)
2266 /* We can't rely on gimplify_expr to re-gimplify the expanded
2267 form properly, as cleanups might cause the target labels to be
2268 wrapped in a TRY_FINALLY_EXPR. To prevent that, we need to
2269 set up a conditional context. */
2270 gimple_push_condition ();
2271 gimplify_stmt (expr_p);
2272 gimple_pop_condition (pre_p);
2278 /* Now do the normal gimplification. */
2279 ret = gimplify_expr (&TREE_OPERAND (expr, 0), pre_p, NULL,
2280 is_gimple_condexpr, fb_rvalue);
2282 gimple_push_condition ();
2284 gimplify_to_stmt_list (&TREE_OPERAND (expr, 1));
2285 gimplify_to_stmt_list (&TREE_OPERAND (expr, 2));
2286 recalculate_side_effects (expr);
2288 gimple_pop_condition (pre_p);
2290 if (ret == GS_ERROR)
2292 else if (TREE_SIDE_EFFECTS (TREE_OPERAND (expr, 1)))
2294 else if (TREE_SIDE_EFFECTS (TREE_OPERAND (expr, 2)))
2295 /* Rewrite "if (a); else b" to "if (!a) b" */
2297 TREE_OPERAND (expr, 0) = invert_truthvalue (TREE_OPERAND (expr, 0));
2298 ret = gimplify_expr (&TREE_OPERAND (expr, 0), pre_p, NULL,
2299 is_gimple_condexpr, fb_rvalue);
2301 tmp = TREE_OPERAND (expr, 1);
2302 TREE_OPERAND (expr, 1) = TREE_OPERAND (expr, 2);
2303 TREE_OPERAND (expr, 2) = tmp;
2306 /* Both arms are empty; replace the COND_EXPR with its predicate. */
2307 expr = TREE_OPERAND (expr, 0);
2313 /* A subroutine of gimplify_modify_expr. Replace a MODIFY_EXPR with
2314 a call to __builtin_memcpy. */
2316 static enum gimplify_status
2317 gimplify_modify_expr_to_memcpy (tree *expr_p, bool want_value)
2319 tree args, t, to, to_ptr, from;
2321 to = TREE_OPERAND (*expr_p, 0);
2322 from = TREE_OPERAND (*expr_p, 1);
2324 t = TYPE_SIZE_UNIT (TREE_TYPE (to));
2325 t = unshare_expr (t);
2326 t = SUBSTITUTE_PLACEHOLDER_IN_EXPR (t, to);
2327 t = SUBSTITUTE_PLACEHOLDER_IN_EXPR (t, from);
2328 args = tree_cons (NULL, t, NULL);
2330 t = build_fold_addr_expr (from);
2331 args = tree_cons (NULL, t, args);
2333 to_ptr = build_fold_addr_expr (to);
2334 args = tree_cons (NULL, to_ptr, args);
2335 t = implicit_built_in_decls[BUILT_IN_MEMCPY];
2336 t = build_function_call_expr (t, args);
2340 t = build1 (NOP_EXPR, TREE_TYPE (to_ptr), t);
2341 t = build1 (INDIRECT_REF, TREE_TYPE (to), t);
2348 /* A subroutine of gimplify_modify_expr. Replace a MODIFY_EXPR with
2349 a call to __builtin_memset. In this case we know that the RHS is
2350 a CONSTRUCTOR with an empty element list. */
2352 static enum gimplify_status
2353 gimplify_modify_expr_to_memset (tree *expr_p, bool want_value)
2355 tree args, t, to, to_ptr;
2357 to = TREE_OPERAND (*expr_p, 0);
2359 t = TYPE_SIZE_UNIT (TREE_TYPE (to));
2360 t = unshare_expr (t);
2361 t = SUBSTITUTE_PLACEHOLDER_IN_EXPR (t, to);
2362 args = tree_cons (NULL, t, NULL);
2364 args = tree_cons (NULL, integer_zero_node, args);
2366 to_ptr = build_fold_addr_expr (to);
2367 args = tree_cons (NULL, to_ptr, args);
2368 t = implicit_built_in_decls[BUILT_IN_MEMSET];
2369 t = build_function_call_expr (t, args);
2373 t = build1 (NOP_EXPR, TREE_TYPE (to_ptr), t);
2374 t = build1 (INDIRECT_REF, TREE_TYPE (to), t);
2381 /* A subroutine of gimplify_modify_expr. Break out elements of a
2382 CONSTRUCTOR used as an initializer into separate MODIFY_EXPRs.
2384 Note that we still need to clear any elements that don't have explicit
2385 initializers, so if not all elements are initialized we keep the
2386 original MODIFY_EXPR, we just remove all of the constructor elements. */
2388 static enum gimplify_status
2389 gimplify_init_constructor (tree *expr_p, tree *pre_p,
2390 tree *post_p, bool want_value)
2392 tree object = TREE_OPERAND (*expr_p, 0);
2393 tree ctor = TREE_OPERAND (*expr_p, 1);
2394 tree type = TREE_TYPE (ctor);
2395 enum gimplify_status ret;
2398 if (TREE_CODE (ctor) != CONSTRUCTOR)
2399 return GS_UNHANDLED;
2401 elt_list = CONSTRUCTOR_ELTS (ctor);
2404 switch (TREE_CODE (type))
2408 case QUAL_UNION_TYPE:
2411 HOST_WIDE_INT i, num_elements, num_nonzero_elements;
2412 HOST_WIDE_INT num_nonconstant_elements;
2415 /* Aggregate types must lower constructors to initialization of
2416 individual elements. The exception is that a CONSTRUCTOR node
2417 with no elements indicates zero-initialization of the whole. */
2418 if (elt_list == NULL)
2426 return GS_UNHANDLED;
2429 categorize_ctor_elements (ctor, &num_nonzero_elements,
2430 &num_nonconstant_elements);
2431 num_elements = count_type_elements (TREE_TYPE (ctor));
2433 /* If a const aggregate variable is being initialized, then it
2434 should never be a lose to promote the variable to be static. */
2435 if (num_nonconstant_elements == 0
2436 && TREE_READONLY (object)
2437 && TREE_CODE (object) == VAR_DECL)
2439 DECL_INITIAL (object) = ctor;
2440 TREE_STATIC (object) = 1;
2441 if (!DECL_NAME (object))
2442 DECL_NAME (object) = create_tmp_var_name ("C");
2443 walk_tree (&DECL_INITIAL (object), force_labels_r, NULL, NULL);
2445 /* ??? C++ doesn't automatically append a .<number> to the
2446 assembler name, and even when it does, it looks a FE private
2447 data structures to figure out what that number should be,
2448 which are not set for this variable. I suppose this is
2449 important for local statics for inline functions, which aren't
2450 "local" in the object file sense. So in order to get a unique
2451 TU-local symbol, we must invoke the lhd version now. */
2452 lhd_set_decl_assembler_name (object);
2454 *expr_p = NULL_TREE;
2458 /* If there are "lots" of initialized elements, and all of them
2459 are valid address constants, then the entire initializer can
2460 be dropped to memory, and then memcpy'd out. */
2461 if (num_nonconstant_elements == 0)
2463 HOST_WIDE_INT size = int_size_in_bytes (type);
2466 /* ??? We can still get unbounded array types, at least
2467 from the C++ front end. This seems wrong, but attempt
2468 to work around it for now. */
2471 size = int_size_in_bytes (TREE_TYPE (object));
2473 TREE_TYPE (ctor) = type = TREE_TYPE (object);
2476 /* Find the maximum alignment we can assume for the object. */
2477 /* ??? Make use of DECL_OFFSET_ALIGN. */
2478 if (DECL_P (object))
2479 align = DECL_ALIGN (object);
2481 align = TYPE_ALIGN (type);
2483 if (size > 0 && !can_move_by_pieces (size, align))
2485 tree new = create_tmp_var_raw (type, "C");
2486 gimple_add_tmp_var (new);
2487 TREE_STATIC (new) = 1;
2488 TREE_READONLY (new) = 1;
2489 DECL_INITIAL (new) = ctor;
2490 if (align > DECL_ALIGN (new))
2492 DECL_ALIGN (new) = align;
2493 DECL_USER_ALIGN (new) = 1;
2495 walk_tree (&DECL_INITIAL (new), force_labels_r, NULL, NULL);
2497 TREE_OPERAND (*expr_p, 1) = new;
2502 /* If there are "lots" of initialized elements, even discounting
2503 those that are not address constants (and thus *must* be
2504 computed at runtime), then partition the constructor into
2505 constant and non-constant parts. Block copy the constant
2506 parts in, then generate code for the non-constant parts. */
2507 /* TODO. There's code in cp/typeck.c to do this. */
2509 /* If there are "lots" of zeros, then block clear the object first. */
2511 if (num_elements - num_nonzero_elements > CLEAR_RATIO
2512 && num_nonzero_elements < num_elements/4)
2515 /* ??? This bit ought not be needed. For any element not present
2516 in the initializer, we should simply set them to zero. Except
2517 we'd need to *find* the elements that are not present, and that
2518 requires trickery to avoid quadratic compile-time behavior in
2519 large cases or excessive memory use in small cases. */
2522 HOST_WIDE_INT len = list_length (elt_list);
2523 if (TREE_CODE (type) == ARRAY_TYPE)
2525 tree nelts = array_type_nelts (type);
2526 if (!host_integerp (nelts, 1)
2527 || tree_low_cst (nelts, 1) != len)
2530 else if (len != fields_length (type))
2536 /* Zap the CONSTRUCTOR element list, which simplifies this case.
2537 Note that we still have to gimplify, in order to handle the
2538 case of variable sized types. Make an unshared copy of
2539 OBJECT before that so we can match a PLACEHOLDER_EXPR to it
2540 later, if needed. */
2541 CONSTRUCTOR_ELTS (ctor) = NULL_TREE;
2542 object = unshare_expr (TREE_OPERAND (*expr_p, 0));
2543 gimplify_stmt (expr_p);
2544 append_to_statement_list (*expr_p, pre_p);
2547 for (i = 0; elt_list; i++, elt_list = TREE_CHAIN (elt_list))
2549 tree purpose, value, cref, init;
2551 purpose = TREE_PURPOSE (elt_list);
2552 value = TREE_VALUE (elt_list);
2554 if (cleared && initializer_zerop (value))
2557 if (TREE_CODE (type) == ARRAY_TYPE)
2559 tree t = TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (object)));
2561 /* ??? Here's to hoping the front end fills in all of the
2562 indicies, so we don't have to figure out what's missing
2566 /* ??? Need to handle this. */
2567 if (TREE_CODE (purpose) == RANGE_EXPR)
2570 cref = build (ARRAY_REF, t, unshare_expr (object), purpose,
2571 NULL_TREE, NULL_TREE);
2574 cref = build (COMPONENT_REF, TREE_TYPE (purpose),
2575 unshare_expr (object), purpose, NULL_TREE);
2577 init = build (MODIFY_EXPR, TREE_TYPE (purpose), cref, value);
2579 /* Each member initialization is a full-expression. */
2580 gimplify_and_add (init, pre_p);
2583 *expr_p = NULL_TREE;
2591 /* Extract the real and imaginary parts out of the ctor. */
2595 r = TREE_VALUE (elt_list);
2596 elt_list = TREE_CHAIN (elt_list);
2599 i = TREE_VALUE (elt_list);
2600 if (TREE_CHAIN (elt_list))
2604 if (r == NULL || i == NULL)
2606 tree zero = convert (TREE_TYPE (type), integer_zero_node);
2613 /* Complex types have either COMPLEX_CST or COMPLEX_EXPR to
2614 represent creation of a complex value. */
2615 if (TREE_CONSTANT (r) && TREE_CONSTANT (i))
2617 ctor = build_complex (type, r, i);
2618 TREE_OPERAND (*expr_p, 1) = ctor;
2622 ctor = build (COMPLEX_EXPR, type, r, i);
2623 TREE_OPERAND (*expr_p, 1) = ctor;
2624 ret = gimplify_expr (&TREE_OPERAND (*expr_p, 1), pre_p, post_p,
2625 is_gimple_rhs, fb_rvalue);
2631 /* Go ahead and simplify constant constructors to VECTOR_CST. */
2632 if (TREE_CONSTANT (ctor))
2633 TREE_OPERAND (*expr_p, 1) = build_vector (type, elt_list);
2636 /* Vector types use CONSTRUCTOR all the way through gimple
2637 compilation as a general initializer. */
2638 for (; elt_list; elt_list = TREE_CHAIN (elt_list))
2640 enum gimplify_status tret;
2641 tret = gimplify_expr (&TREE_VALUE (elt_list), pre_p, post_p,
2642 is_gimple_constructor_elt, fb_rvalue);
2643 if (tret == GS_ERROR)
2650 /* So how did we get a CONSTRUCTOR for a scalar type? */
2654 if (ret == GS_ERROR)
2656 else if (want_value)
2658 append_to_statement_list (*expr_p, pre_p);
2666 /* Subroutine of gimplify_modify_expr to do simplifications of MODIFY_EXPRs
2667 based on the code of the RHS. We loop for as long as something changes. */
2669 static enum gimplify_status
2670 gimplify_modify_expr_rhs (tree *expr_p, tree *from_p, tree *to_p, tree *pre_p,
2671 tree *post_p, bool want_value)
2673 enum gimplify_status ret = GS_OK;
2675 while (ret != GS_UNHANDLED)
2676 switch (TREE_CODE (*from_p))
2680 /* If we are initializing something from a TARGET_EXPR, strip the
2681 TARGET_EXPR and initialize it directly, if possible. This can't
2682 be done if the initializer is void, since that implies that the
2683 temporary is set in some non-trivial way.
2685 ??? What about code that pulls out the temp and uses it
2686 elsewhere? I think that such code never uses the TARGET_EXPR as
2687 an initializer. If I'm wrong, we'll abort because the temp won't
2688 have any RTL. In that case, I guess we'll need to replace
2689 references somehow. */
2690 tree init = TARGET_EXPR_INITIAL (*from_p);
2692 if (!VOID_TYPE_P (TREE_TYPE (init)))
2703 /* Remove any COMPOUND_EXPR in the RHS so the following cases will be
2705 gimplify_compound_expr (from_p, pre_p, true);
2710 /* If we're initializing from a CONSTRUCTOR, break this into
2711 individual MODIFY_EXPRs. */
2712 return gimplify_init_constructor (expr_p, pre_p, post_p, want_value);
2715 /* If we're assigning from a ?: expression with ADDRESSABLE type, push
2716 the assignment down into the branches, since we can't generate a
2717 temporary of such a type. */
2718 if (TREE_ADDRESSABLE (TREE_TYPE (*from_p)))
2721 return gimplify_cond_expr (expr_p, pre_p, *to_p);
2735 /* Gimplify the MODIFY_EXPR node pointed by EXPR_P.
2741 PRE_P points to the list where side effects that must happen before
2742 *EXPR_P should be stored.
2744 POST_P points to the list where side effects that must happen after
2745 *EXPR_P should be stored.
2747 WANT_VALUE is nonzero iff we want to use the value of this expression
2748 in another expression. */
2750 static enum gimplify_status
2751 gimplify_modify_expr (tree *expr_p, tree *pre_p, tree *post_p, bool want_value)
2753 tree *from_p = &TREE_OPERAND (*expr_p, 1);
2754 tree *to_p = &TREE_OPERAND (*expr_p, 0);
2755 enum gimplify_status ret = GS_UNHANDLED;
2757 #if defined ENABLE_CHECKING
2758 if (TREE_CODE (*expr_p) != MODIFY_EXPR && TREE_CODE (*expr_p) != INIT_EXPR)
2762 /* The distinction between MODIFY_EXPR and INIT_EXPR is no longer useful. */
2763 if (TREE_CODE (*expr_p) == INIT_EXPR)
2764 TREE_SET_CODE (*expr_p, MODIFY_EXPR);
2766 /* See if any simplifications can be done based on what the RHS is. */
2767 ret = gimplify_modify_expr_rhs (expr_p, from_p, to_p, pre_p, post_p,
2769 if (ret != GS_UNHANDLED)
2772 /* If the value being copied is of variable width, expose the length
2773 if the copy by converting the whole thing to a memcpy/memset.
2774 Note that we need to do this before gimplifying any of the operands
2775 so that we can resolve any PLACEHOLDER_EXPRs in the size. */
2776 if (TREE_CODE (TYPE_SIZE_UNIT (TREE_TYPE (*to_p))) != INTEGER_CST)
2778 if (TREE_CODE (*from_p) == CONSTRUCTOR)
2779 return gimplify_modify_expr_to_memset (expr_p, want_value);
2781 return gimplify_modify_expr_to_memcpy (expr_p, want_value);
2784 ret = gimplify_expr (to_p, pre_p, post_p, is_gimple_lvalue, fb_lvalue);
2785 if (ret == GS_ERROR)
2788 ret = gimplify_expr (from_p, pre_p, post_p, is_gimple_rhs, fb_rvalue);
2789 if (ret == GS_ERROR)
2792 /* Now see if the above changed *from_p to something we handle specially. */
2793 ret = gimplify_modify_expr_rhs (expr_p, from_p, to_p, pre_p, post_p,
2795 if (ret != GS_UNHANDLED)
2798 /* If the destination is already simple, nothing else needed. */
2799 if (is_gimple_tmp_var (*to_p))
2803 /* If the RHS of the MODIFY_EXPR may throw or make a nonlocal goto and
2804 the LHS is a user variable, then we need to introduce a temporary.
2805 ie temp = RHS; LHS = temp.
2807 This way the optimizers can determine that the user variable is
2808 only modified if evaluation of the RHS does not throw.
2810 FIXME this should be handled by the is_gimple_rhs predicate. */
2812 if (aggregate_value_p (TREE_TYPE (*from_p), NULL_TREE))
2813 /* Don't force a temp of a large aggregate type; the copy could be
2814 arbitrarily expensive. Instead we will generate a V_MAY_DEF for
2816 else if (TREE_CODE (*from_p) == CALL_EXPR
2817 || (flag_non_call_exceptions && tree_could_trap_p (*from_p))
2818 /* If we're dealing with a renamable type, either source or dest
2819 must be a renamed variable. */
2820 || (is_gimple_reg_type (TREE_TYPE (*from_p))
2821 && !is_gimple_reg (*to_p)))
2822 gimplify_expr (from_p, pre_p, post_p, is_gimple_val, fb_rvalue);
2824 ret = want_value ? GS_OK : GS_ALL_DONE;
2829 append_to_statement_list (*expr_p, pre_p);
2836 /* Gimplify a comparison between two variable-sized objects. Do this
2837 with a call to BUILT_IN_MEMCMP. */
2839 static enum gimplify_status
2840 gimplify_variable_sized_compare (tree *expr_p)
2842 tree op0 = TREE_OPERAND (*expr_p, 0);
2843 tree op1 = TREE_OPERAND (*expr_p, 1);
2846 t = TYPE_SIZE_UNIT (TREE_TYPE (op0));
2847 t = unshare_expr (t);
2848 t = SUBSTITUTE_PLACEHOLDER_IN_EXPR (t, op0);
2849 args = tree_cons (NULL, t, NULL);
2850 t = build_fold_addr_expr (op1);
2851 args = tree_cons (NULL, t, args);
2852 dest = build_fold_addr_expr (op0);
2853 args = tree_cons (NULL, dest, args);
2854 t = implicit_built_in_decls[BUILT_IN_MEMCMP];
2855 t = build_function_call_expr (t, args);
2857 = build (TREE_CODE (*expr_p), TREE_TYPE (*expr_p), t, integer_zero_node);
2862 /* Gimplify TRUTH_ANDIF_EXPR and TRUTH_ORIF_EXPR expressions. EXPR_P
2863 points to the expression to gimplify.
2865 Expressions of the form 'a && b' are gimplified to:
2867 a && b ? true : false
2869 gimplify_cond_expr will do the rest.
2871 PRE_P points to the list where side effects that must happen before
2872 *EXPR_P should be stored. */
2874 static enum gimplify_status
2875 gimplify_boolean_expr (tree *expr_p)
2877 /* Preserve the original type of the expression. */
2878 tree type = TREE_TYPE (*expr_p);
2880 *expr_p = build (COND_EXPR, type, *expr_p,
2881 convert (type, boolean_true_node),
2882 convert (type, boolean_false_node));
2887 /* Gimplifies an expression sequence. This function gimplifies each
2888 expression and re-writes the original expression with the last
2889 expression of the sequence in GIMPLE form.
2891 PRE_P points to the list where the side effects for all the
2892 expressions in the sequence will be emitted.
2894 WANT_VALUE is true when the result of the last COMPOUND_EXPR is used. */
2895 /* ??? Should rearrange to share the pre-queue with all the indirect
2896 invocations of gimplify_expr. Would probably save on creations
2897 of statement_list nodes. */
2899 static enum gimplify_status
2900 gimplify_compound_expr (tree *expr_p, tree *pre_p, bool want_value)
2906 tree *sub_p = &TREE_OPERAND (t, 0);
2908 if (TREE_CODE (*sub_p) == COMPOUND_EXPR)
2909 gimplify_compound_expr (sub_p, pre_p, false);
2911 gimplify_stmt (sub_p);
2912 append_to_statement_list (*sub_p, pre_p);
2914 t = TREE_OPERAND (t, 1);
2916 while (TREE_CODE (t) == COMPOUND_EXPR);
2923 gimplify_stmt (expr_p);
2928 /* Gimplifies a statement list. These may be created either by an
2929 enlightened front-end, or by shortcut_cond_expr. */
2931 static enum gimplify_status
2932 gimplify_statement_list (tree *expr_p)
2934 tree_stmt_iterator i = tsi_start (*expr_p);
2936 while (!tsi_end_p (i))
2940 gimplify_stmt (tsi_stmt_ptr (i));
2945 else if (TREE_CODE (t) == STATEMENT_LIST)
2947 tsi_link_before (&i, t, TSI_SAME_STMT);
2957 /* Gimplify a SAVE_EXPR node. EXPR_P points to the expression to
2958 gimplify. After gimplification, EXPR_P will point to a new temporary
2959 that holds the original value of the SAVE_EXPR node.
2961 PRE_P points to the list where side effects that must happen before
2962 *EXPR_P should be stored. */
2964 static enum gimplify_status
2965 gimplify_save_expr (tree *expr_p, tree *pre_p, tree *post_p)
2967 enum gimplify_status ret = GS_ALL_DONE;
2970 #if defined ENABLE_CHECKING
2971 if (TREE_CODE (*expr_p) != SAVE_EXPR)
2975 val = TREE_OPERAND (*expr_p, 0);
2977 /* If the operand is already a GIMPLE temporary, just re-write the
2979 if (is_gimple_tmp_var (val))
2981 /* The operand may be a void-valued expression such as SAVE_EXPRs
2982 generated by the Java frontend for class initialization. It is
2983 being executed only for its side-effects. */
2984 else if (TREE_TYPE (val) == void_type_node)
2986 tree body = TREE_OPERAND (*expr_p, 0);
2987 ret = gimplify_expr (& body, pre_p, post_p, is_gimple_stmt, fb_none);
2988 append_to_statement_list (body, pre_p);
2992 *expr_p = TREE_OPERAND (*expr_p, 0)
2993 = get_initialized_tmp_var (val, pre_p, post_p);
2998 /* Re-write the ADDR_EXPR node pointed by EXPR_P
3005 PRE_P points to the list where side effects that must happen before
3006 *EXPR_P should be stored.
3008 POST_P points to the list where side effects that must happen after
3009 *EXPR_P should be stored. */
3011 static enum gimplify_status
3012 gimplify_addr_expr (tree *expr_p, tree *pre_p, tree *post_p)
3014 tree expr = *expr_p;
3015 tree op0 = TREE_OPERAND (expr, 0);
3016 enum gimplify_status ret;
3018 switch (TREE_CODE (op0))
3021 /* Check if we are dealing with an expression of the form '&*ptr'.
3022 While the front end folds away '&*ptr' into 'ptr', these
3023 expressions may be generated internally by the compiler (e.g.,
3024 builtins like __builtin_va_end). */
3025 *expr_p = TREE_OPERAND (op0, 0);
3030 /* Fold &a[6] to (&a + 6). */
3031 ret = gimplify_array_ref_to_plus (&TREE_OPERAND (expr, 0),
3034 /* This added an INDIRECT_REF. Fold it away. */
3035 *expr_p = TREE_OPERAND (TREE_OPERAND (expr, 0), 0);
3038 case VIEW_CONVERT_EXPR:
3039 /* Take the address of our operand and then convert it to the type of
3042 ??? The interactions of VIEW_CONVERT_EXPR and aliasing is not at
3043 all clear. The impact of this transformation is even less clear. */
3044 *expr_p = fold_convert (TREE_TYPE (expr),
3045 build_fold_addr_expr (TREE_OPERAND (op0, 0)));
3050 /* We use fb_either here because the C frontend sometimes takes
3051 the address of a call that returns a struct. */
3052 ret = gimplify_expr (&TREE_OPERAND (expr, 0), pre_p, post_p,
3053 is_gimple_addr_expr_arg, fb_either);
3054 if (ret != GS_ERROR)
3056 /* At this point, the argument of the ADDR_EXPR should be
3057 sufficiently simple that there are never side effects. */
3058 /* ??? Could split out the decision code from build1 to verify. */
3059 TREE_SIDE_EFFECTS (expr) = 0;
3061 /* Make sure TREE_INVARIANT/TREE_CONSTANT is set properly. */
3062 recompute_tree_invarant_for_addr_expr (expr);
3064 /* Mark the RHS addressable. */
3065 lang_hooks.mark_addressable (TREE_OPERAND (expr, 0));
3070 /* If the operand is gimplified into a _DECL, mark the address expression
3071 as TREE_INVARIANT. */
3072 if (DECL_P (TREE_OPERAND (expr, 0)))
3073 TREE_INVARIANT (expr) = 1;
3078 /* Gimplify the operands of an ASM_EXPR. Input operands should be a gimple
3079 value; output operands should be a gimple lvalue. */
3081 static enum gimplify_status
3082 gimplify_asm_expr (tree *expr_p, tree *pre_p, tree *post_p)
3084 tree expr = *expr_p;
3085 int noutputs = list_length (ASM_OUTPUTS (expr));
3086 const char **oconstraints
3087 = (const char **) alloca ((noutputs) * sizeof (const char *));
3090 const char *constraint;
3091 bool allows_mem, allows_reg, is_inout;
3092 enum gimplify_status ret, tret;
3095 = resolve_asm_operand_names (ASM_STRING (expr), ASM_OUTPUTS (expr),
3099 for (i = 0, link = ASM_OUTPUTS (expr); link; ++i, link = TREE_CHAIN (link))
3101 oconstraints[i] = constraint
3102 = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (link)));
3104 parse_output_constraint (&constraint, i, 0, 0,
3105 &allows_mem, &allows_reg, &is_inout);
3107 if (!allows_reg && allows_mem)
3108 lang_hooks.mark_addressable (TREE_VALUE (link));
3110 tret = gimplify_expr (&TREE_VALUE (link), pre_p, post_p,
3111 is_inout ? is_gimple_min_lval : is_gimple_lvalue,
3112 fb_lvalue | fb_mayfail);
3113 if (tret == GS_ERROR)
3115 error ("invalid lvalue in asm output %d", i);
3121 /* An input/output operand. To give the optimizers more
3122 flexibility, split it into separate input and output
3126 size_t constraint_len = strlen (constraint);
3128 /* Turn the in/out constraint into an output constraint. */
3129 char *p = xstrdup (constraint);
3131 TREE_VALUE (TREE_PURPOSE (link)) = build_string (constraint_len, p);
3134 /* And add a matching input constraint. */
3137 sprintf (buf, "%d", i);
3138 input = build_string (strlen (buf), buf);
3141 input = build_string (constraint_len - 1, constraint + 1);
3142 input = build_tree_list (build_tree_list (NULL_TREE, input),
3143 unshare_expr (TREE_VALUE (link)));
3144 ASM_INPUTS (expr) = chainon (ASM_INPUTS (expr), input);
3148 for (link = ASM_INPUTS (expr); link; ++i, link = TREE_CHAIN (link))
3151 = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (link)));
3152 parse_input_constraint (&constraint, 0, 0, noutputs, 0,
3153 oconstraints, &allows_mem, &allows_reg);
3155 /* If the operand is a memory input, it should be an lvalue. */
3156 if (!allows_reg && allows_mem)
3158 lang_hooks.mark_addressable (TREE_VALUE (link));
3159 tret = gimplify_expr (&TREE_VALUE (link), pre_p, post_p,
3160 is_gimple_lvalue, fb_lvalue | fb_mayfail);
3161 if (tret == GS_ERROR)
3163 error ("memory input %d is not directly addressable", i);
3169 tret = gimplify_expr (&TREE_VALUE (link), pre_p, post_p,
3170 is_gimple_val, fb_rvalue);
3171 if (tret == GS_ERROR)
3179 /* Gimplify a CLEANUP_POINT_EXPR. Currently this works by adding
3180 WITH_CLEANUP_EXPRs to the prequeue as we encounter cleanups while
3181 gimplifying the body, and converting them to TRY_FINALLY_EXPRs when we
3182 return to this function.
3184 FIXME should we complexify the prequeue handling instead? Or use flags
3185 for all the cleanups and let the optimizer tighten them up? The current
3186 code seems pretty fragile; it will break on a cleanup within any
3187 non-conditional nesting. But any such nesting would be broken, anyway;
3188 we can't write a TRY_FINALLY_EXPR that starts inside a nesting construct
3189 and continues out of it. We can do that at the RTL level, though, so
3190 having an optimizer to tighten up try/finally regions would be a Good
3193 static enum gimplify_status
3194 gimplify_cleanup_point_expr (tree *expr_p, tree *pre_p)
3196 tree_stmt_iterator iter;
3199 tree temp = voidify_wrapper_expr (*expr_p, NULL);
3201 /* We only care about the number of conditions between the innermost
3202 CLEANUP_POINT_EXPR and the cleanup. So save and reset the count. */
3203 int old_conds = gimplify_ctxp->conditions;
3204 gimplify_ctxp->conditions = 0;
3206 body = TREE_OPERAND (*expr_p, 0);
3207 gimplify_to_stmt_list (&body);
3209 gimplify_ctxp->conditions = old_conds;
3211 for (iter = tsi_start (body); !tsi_end_p (iter); )
3213 tree *wce_p = tsi_stmt_ptr (iter);
3216 if (TREE_CODE (wce) == WITH_CLEANUP_EXPR)
3218 if (tsi_one_before_end_p (iter))
3220 tsi_link_before (&iter, TREE_OPERAND (wce, 1), TSI_SAME_STMT);
3228 sl = tsi_split_statement_list_after (&iter);
3229 tfe = build (TRY_FINALLY_EXPR, void_type_node, sl, NULL_TREE);
3230 append_to_statement_list (TREE_OPERAND (wce, 1),
3231 &TREE_OPERAND (tfe, 1));
3233 iter = tsi_start (sl);
3243 append_to_statement_list (body, pre_p);
3253 /* Insert a cleanup marker for gimplify_cleanup_point_expr. CLEANUP
3254 is the cleanup action required. */
3257 gimple_push_cleanup (tree var, tree cleanup, tree *pre_p)
3261 /* Errors can result in improperly nested cleanups. Which results in
3262 confusion when trying to resolve the WITH_CLEANUP_EXPR. */
3263 if (errorcount || sorrycount)
3266 if (gimple_conditional_context ())
3268 /* If we're in a conditional context, this is more complex. We only
3269 want to run the cleanup if we actually ran the initialization that
3270 necessitates it, but we want to run it after the end of the
3271 conditional context. So we wrap the try/finally around the
3272 condition and use a flag to determine whether or not to actually
3273 run the destructor. Thus
3277 becomes (approximately)
3281 if (test) { A::A(temp); flag = 1; val = f(temp); }
3284 if (flag) A::~A(temp);
3289 tree flag = create_tmp_var (boolean_type_node, "cleanup");
3290 tree ffalse = build (MODIFY_EXPR, void_type_node, flag,
3291 boolean_false_node);
3292 tree ftrue = build (MODIFY_EXPR, void_type_node, flag,
3294 cleanup = build (COND_EXPR, void_type_node, flag, cleanup, NULL);
3295 wce = build (WITH_CLEANUP_EXPR, void_type_node, NULL_TREE,
3296 cleanup, NULL_TREE);
3297 append_to_statement_list (ffalse, &gimplify_ctxp->conditional_cleanups);
3298 append_to_statement_list (wce, &gimplify_ctxp->conditional_cleanups);
3299 append_to_statement_list (ftrue, pre_p);
3301 /* Because of this manipulation, and the EH edges that jump
3302 threading cannot redirect, the temporary (VAR) will appear
3303 to be used uninitialized. Don't warn. */
3304 TREE_NO_WARNING (var) = 1;
3308 wce = build (WITH_CLEANUP_EXPR, void_type_node, NULL_TREE,
3309 cleanup, NULL_TREE);
3310 append_to_statement_list (wce, pre_p);
3313 gimplify_stmt (&TREE_OPERAND (wce, 1));
3316 /* Gimplify a TARGET_EXPR which doesn't appear on the rhs of an INIT_EXPR. */
3318 static enum gimplify_status
3319 gimplify_target_expr (tree *expr_p, tree *pre_p, tree *post_p)
3321 tree targ = *expr_p;
3322 tree temp = TARGET_EXPR_SLOT (targ);
3323 tree init = TARGET_EXPR_INITIAL (targ);
3324 enum gimplify_status ret;
3328 /* TARGET_EXPR temps aren't part of the enclosing block, so add it
3329 to the temps list. */
3330 gimple_add_tmp_var (temp);
3332 /* If TARGET_EXPR_INITIAL is void, then the mere evaluation of the
3333 expression is supposed to initialize the slot. */
3334 if (VOID_TYPE_P (TREE_TYPE (init)))
3335 ret = gimplify_expr (&init, pre_p, post_p, is_gimple_stmt, fb_none);
3338 /* Special handling for BIND_EXPR can result in fewer temps. */
3340 if (TREE_CODE (init) == BIND_EXPR)
3341 gimplify_bind_expr (&init, temp, pre_p);
3344 init = build (MODIFY_EXPR, void_type_node, temp, init);
3345 ret = gimplify_expr (&init, pre_p, post_p, is_gimple_stmt,
3349 if (ret == GS_ERROR)
3351 append_to_statement_list (init, pre_p);
3353 /* If needed, push the cleanup for the temp. */
3354 if (TARGET_EXPR_CLEANUP (targ))
3356 gimplify_stmt (&TARGET_EXPR_CLEANUP (targ));
3357 gimple_push_cleanup (temp, TARGET_EXPR_CLEANUP (targ), pre_p);
3360 /* Only expand this once. */
3361 TREE_OPERAND (targ, 3) = init;
3362 TARGET_EXPR_INITIAL (targ) = NULL_TREE;
3364 else if (!temp->decl.seen_in_bind_expr)
3365 /* We should have expanded this before. */
3372 /* Gimplification of expression trees. */
3374 /* Gimplify an expression which appears at statement context; usually, this
3375 means replacing it with a suitably gimple STATEMENT_LIST. */
3378 gimplify_stmt (tree *stmt_p)
3380 gimplify_expr (stmt_p, NULL, NULL, is_gimple_stmt, fb_none);
3383 /* Similarly, but force the result to be a STATEMENT_LIST. */
3386 gimplify_to_stmt_list (tree *stmt_p)
3388 gimplify_stmt (stmt_p);
3390 *stmt_p = alloc_stmt_list ();
3391 else if (TREE_CODE (*stmt_p) != STATEMENT_LIST)
3394 *stmt_p = alloc_stmt_list ();
3395 append_to_statement_list (t, stmt_p);
3400 /* Gimplifies the expression tree pointed by EXPR_P. Return 0 if
3401 gimplification failed.
3403 PRE_P points to the list where side effects that must happen before
3404 EXPR should be stored.
3406 POST_P points to the list where side effects that must happen after
3407 EXPR should be stored, or NULL if there is no suitable list. In
3408 that case, we copy the result to a temporary, emit the
3409 post-effects, and then return the temporary.
3411 GIMPLE_TEST_F points to a function that takes a tree T and
3412 returns nonzero if T is in the GIMPLE form requested by the
3413 caller. The GIMPLE predicates are in tree-gimple.c.
3415 This test is used twice. Before gimplification, the test is
3416 invoked to determine whether *EXPR_P is already gimple enough. If
3417 that fails, *EXPR_P is gimplified according to its code and
3418 GIMPLE_TEST_F is called again. If the test still fails, then a new
3419 temporary variable is created and assigned the value of the
3420 gimplified expression.
3422 FALLBACK tells the function what sort of a temporary we want. If the 1
3423 bit is set, an rvalue is OK. If the 2 bit is set, an lvalue is OK.
3424 If both are set, either is OK, but an lvalue is preferable.
3426 The return value is either GS_ERROR or GS_ALL_DONE, since this function
3427 iterates until solution. */
3429 enum gimplify_status
3430 gimplify_expr (tree *expr_p, tree *pre_p, tree *post_p,
3431 bool (* gimple_test_f) (tree), fallback_t fallback)
3434 tree internal_pre = NULL_TREE;
3435 tree internal_post = NULL_TREE;
3437 int is_statement = (pre_p == NULL);
3438 location_t saved_location;
3439 enum gimplify_status ret;
3441 save_expr = *expr_p;
3442 if (save_expr == NULL_TREE)
3445 /* We used to check the predicate here and return immediately if it
3446 succeeds. This is wrong; the design is for gimplification to be
3447 idempotent, and for the predicates to only test for valid forms, not
3448 whether they are fully simplified. */
3450 /* Set up our internal queues if needed. */
3452 pre_p = &internal_pre;
3454 post_p = &internal_post;
3456 saved_location = input_location;
3457 if (save_expr != error_mark_node
3458 && EXPR_HAS_LOCATION (*expr_p))
3459 input_location = EXPR_LOCATION (*expr_p);
3461 /* Loop over the specific gimplifiers until the toplevel node
3462 remains the same. */
3465 /* Strip away as many useless type conversions as possible
3467 STRIP_USELESS_TYPE_CONVERSION (*expr_p);
3469 /* Remember the expr. */
3470 save_expr = *expr_p;
3472 /* Die, die, die, my darling. */
3473 if (save_expr == error_mark_node
3474 || (TREE_TYPE (save_expr)
3475 && TREE_TYPE (save_expr) == error_mark_node))
3481 /* Do any language-specific gimplification. */
3482 ret = lang_hooks.gimplify_expr (expr_p, pre_p, post_p);
3485 if (*expr_p == NULL_TREE)
3487 if (*expr_p != save_expr)
3490 else if (ret != GS_UNHANDLED)
3494 switch (TREE_CODE (*expr_p))
3496 /* First deal with the special cases. */
3498 case POSTINCREMENT_EXPR:
3499 case POSTDECREMENT_EXPR:
3500 case PREINCREMENT_EXPR:
3501 case PREDECREMENT_EXPR:
3502 ret = gimplify_self_mod_expr (expr_p, pre_p, post_p,
3503 fallback != fb_none);
3507 case ARRAY_RANGE_REF:
3511 ret = gimplify_compound_lval (expr_p, pre_p, post_p,
3512 fallback ? fallback : fb_rvalue);
3516 ret = gimplify_cond_expr (expr_p, pre_p, NULL_TREE);
3520 ret = gimplify_call_expr (expr_p, pre_p, fallback != fb_none);
3527 ret = gimplify_compound_expr (expr_p, pre_p, fallback != fb_none);
3532 ret = gimplify_modify_expr (expr_p, pre_p, post_p,
3533 fallback != fb_none);
3536 case TRUTH_ANDIF_EXPR:
3537 case TRUTH_ORIF_EXPR:
3538 ret = gimplify_boolean_expr (expr_p);
3541 case TRUTH_NOT_EXPR:
3542 TREE_OPERAND (*expr_p, 0)
3543 = gimple_boolify (TREE_OPERAND (*expr_p, 0));
3544 ret = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p, post_p,
3545 is_gimple_val, fb_rvalue);
3546 recalculate_side_effects (*expr_p);
3550 ret = gimplify_addr_expr (expr_p, pre_p, post_p);
3554 ret = gimplify_va_arg_expr (expr_p, pre_p, post_p);
3557 case VIEW_CONVERT_EXPR:
3558 if (VOID_TYPE_P (TREE_TYPE (*expr_p))
3559 || fallback == fb_none)
3561 /* Just strip a conversion to void (or in void context) and
3563 *expr_p = TREE_OPERAND (*expr_p, 0);
3567 /* If both types are BLKmode or if one type is of variable size,
3568 convert this into a pointer punning operation. This avoids
3569 copies of large data or making a variable-size temporary.
3571 ??? The interactions of VIEW_CONVERT_EXPR and aliasing is not at
3572 all clear. The impact of this transformation is even less
3575 if ((TYPE_MODE (TREE_TYPE (*expr_p)) == BLKmode
3576 && TYPE_MODE (TREE_TYPE (TREE_OPERAND (*expr_p, 0))) == BLKmode)
3577 || !TREE_CONSTANT (TYPE_SIZE (TREE_TYPE (*expr_p)))
3578 || !TREE_CONSTANT (TYPE_SIZE (TREE_TYPE
3579 (TREE_OPERAND (*expr_p,0)))))
3581 tree restype = TREE_TYPE (*expr_p);
3582 *expr_p = build1 (INDIRECT_REF, TREE_TYPE (*expr_p),
3583 fold_convert (build_pointer_type (restype),
3584 build_fold_addr_expr
3585 (TREE_OPERAND (*expr_p, 0))));
3592 if (IS_EMPTY_STMT (*expr_p))
3598 if (VOID_TYPE_P (TREE_TYPE (*expr_p))
3599 || fallback == fb_none)
3601 /* Just strip a conversion to void (or in void context) and
3603 *expr_p = TREE_OPERAND (*expr_p, 0);
3607 ret = gimplify_conversion (expr_p);
3608 if (ret == GS_ERROR)
3610 if (*expr_p != save_expr)
3614 case FIX_TRUNC_EXPR:
3616 case FIX_FLOOR_EXPR:
3617 case FIX_ROUND_EXPR:
3619 /* unary_expr: ... | '(' cast ')' val | ... */
3620 ret = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p, post_p,
3621 is_gimple_val, fb_rvalue);
3622 recalculate_side_effects (*expr_p);
3626 ret = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p, post_p,
3627 is_gimple_reg, fb_rvalue);
3628 recalculate_side_effects (*expr_p);
3631 /* Constants need not be gimplified. */
3641 *expr_p = DECL_INITIAL (*expr_p);
3645 ret = gimplify_decl_expr (expr_p);
3649 /* FIXME make this a decl. */
3654 ret = gimplify_bind_expr (expr_p, NULL, pre_p);
3658 ret = gimplify_loop_expr (expr_p, pre_p);
3662 ret = gimplify_switch_expr (expr_p, pre_p);
3665 case LABELED_BLOCK_EXPR:
3666 ret = gimplify_labeled_block_expr (expr_p);
3669 case EXIT_BLOCK_EXPR:
3670 ret = gimplify_exit_block_expr (expr_p);
3674 ret = gimplify_exit_expr (expr_p);
3678 /* If the target is not LABEL, then it is a computed jump
3679 and the target needs to be gimplified. */
3680 if (TREE_CODE (GOTO_DESTINATION (*expr_p)) != LABEL_DECL)
3681 ret = gimplify_expr (&GOTO_DESTINATION (*expr_p), pre_p,
3682 NULL, is_gimple_val, fb_rvalue);
3687 #ifdef ENABLE_CHECKING
3688 if (decl_function_context (LABEL_EXPR_LABEL (*expr_p)) != current_function_decl)
3693 case CASE_LABEL_EXPR:
3694 ret = gimplify_case_label_expr (expr_p);
3698 ret = gimplify_return_expr (*expr_p, pre_p);
3702 /* Don't reduce this in place; let gimplify_init_constructor work
3707 /* The following are special cases that are not handled by the
3708 original GIMPLE grammar. */
3710 /* SAVE_EXPR nodes are converted into a GIMPLE identifier and
3713 ret = gimplify_save_expr (expr_p, pre_p, post_p);
3718 enum gimplify_status r0, r1, r2;
3720 r0 = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p, post_p,
3721 is_gimple_lvalue, fb_either);
3722 r1 = gimplify_expr (&TREE_OPERAND (*expr_p, 1), pre_p, post_p,
3723 is_gimple_val, fb_rvalue);
3724 r2 = gimplify_expr (&TREE_OPERAND (*expr_p, 2), pre_p, post_p,
3725 is_gimple_val, fb_rvalue);
3726 recalculate_side_effects (*expr_p);
3728 ret = MIN (r0, MIN (r1, r2));
3732 case NON_LVALUE_EXPR:
3733 /* This should have been stripped above. */
3738 ret = gimplify_asm_expr (expr_p, pre_p, post_p);
3741 case TRY_FINALLY_EXPR:
3742 case TRY_CATCH_EXPR:
3743 gimplify_to_stmt_list (&TREE_OPERAND (*expr_p, 0));
3744 gimplify_to_stmt_list (&TREE_OPERAND (*expr_p, 1));
3748 case CLEANUP_POINT_EXPR:
3749 ret = gimplify_cleanup_point_expr (expr_p, pre_p);
3753 ret = gimplify_target_expr (expr_p, pre_p, post_p);
3757 gimplify_to_stmt_list (&CATCH_BODY (*expr_p));
3761 case EH_FILTER_EXPR:
3762 gimplify_to_stmt_list (&EH_FILTER_FAILURE (*expr_p));
3768 enum gimplify_status r0, r1;
3769 r0 = gimplify_expr (&OBJ_TYPE_REF_OBJECT (*expr_p), pre_p, post_p,
3770 is_gimple_val, fb_rvalue);
3771 r1 = gimplify_expr (&OBJ_TYPE_REF_EXPR (*expr_p), pre_p, post_p,
3772 is_gimple_val, fb_rvalue);
3779 ret = gimplify_minimax_expr (expr_p, pre_p, post_p);
3783 /* We get here when taking the address of a label. We mark
3784 the label as "forced"; meaning it can never be removed and
3785 it is a potential target for any computed goto. */
3786 FORCED_LABEL (*expr_p) = 1;
3790 case STATEMENT_LIST:
3791 ret = gimplify_statement_list (expr_p);
3795 /* ??? If this is a local variable, and it has not been seen in any
3796 outer BIND_EXPR, then it's probably the result of a duplicate
3797 declaration, for which we've already issued an error. It would
3798 be really nice if the front end wouldn't leak these at all.
3799 Currently the only known culprit is C++ destructors, as seen
3800 in g++.old-deja/g++.jason/binding.C. */
3802 if (!TREE_STATIC (tmp) && !DECL_EXTERNAL (tmp)
3803 && decl_function_context (tmp) == current_function_decl
3804 && !tmp->decl.seen_in_bind_expr)
3806 #ifdef ENABLE_CHECKING
3807 if (!errorcount && !sorrycount)
3817 /* If this is a comparison of objects of aggregate type, handle
3818 it specially (by converting to a call to memcmp). It would be
3819 nice to only have to do this for variable-sized objects, but
3820 then we'd have to allow the same nest of reference nodes we
3821 allow for MODIFY_EXPR and that's too complex. */
3822 if (TREE_CODE_CLASS (TREE_CODE (*expr_p)) == '<'
3823 && (AGGREGATE_TYPE_P (TREE_TYPE (TREE_OPERAND (*expr_p, 1)))))
3824 ret = gimplify_variable_sized_compare (expr_p);
3826 /* If *EXPR_P does not need to be special-cased, handle it
3827 according to its class. */
3828 else if (TREE_CODE_CLASS (TREE_CODE (*expr_p)) == '1')
3829 ret = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p,
3830 post_p, is_gimple_val, fb_rvalue);
3831 else if (TREE_CODE_CLASS (TREE_CODE (*expr_p)) == '2'
3832 || TREE_CODE_CLASS (TREE_CODE (*expr_p)) == '<'
3833 || TREE_CODE (*expr_p) == TRUTH_AND_EXPR
3834 || TREE_CODE (*expr_p) == TRUTH_OR_EXPR
3835 || TREE_CODE (*expr_p) == TRUTH_XOR_EXPR)
3837 enum gimplify_status r0, r1;
3839 r0 = gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p,
3840 post_p, is_gimple_val, fb_rvalue);
3841 r1 = gimplify_expr (&TREE_OPERAND (*expr_p, 1), pre_p,
3842 post_p, is_gimple_val, fb_rvalue);
3846 else if (TREE_CODE_CLASS (TREE_CODE (*expr_p)) == 'd'
3847 || TREE_CODE_CLASS (TREE_CODE (*expr_p)) == 'c')
3853 /* Fail if we don't know how to handle this tree code. */
3856 recalculate_side_effects (*expr_p);
3860 /* If we replaced *expr_p, gimplify again. */
3861 if (ret == GS_OK && (*expr_p == NULL || *expr_p == save_expr))
3864 while (ret == GS_OK);
3866 /* If we encountered an error_mark somewhere nested inside, either
3867 stub out the statement or propagate the error back out. */
3868 if (ret == GS_ERROR)
3875 #ifdef ENABLE_CHECKING
3876 /* This was only valid as a return value from the langhook, which
3877 we handled. Make sure it doesn't escape from any other context. */
3878 if (ret == GS_UNHANDLED)
3882 if (fallback == fb_none && *expr_p && !is_gimple_stmt (*expr_p))
3884 /* We aren't looking for a value, and we don't have a valid
3885 statement. If it doesn't have side-effects, throw it away. */
3886 if (!TREE_SIDE_EFFECTS (*expr_p))
3888 else if (!TREE_THIS_VOLATILE (*expr_p))
3890 /* This is probably a _REF that contains something nested that
3891 has side effects. Recurse through the operands to find it. */
3892 enum tree_code code = TREE_CODE (*expr_p);
3894 if (code == COMPONENT_REF
3895 || code == REALPART_EXPR || code == IMAGPART_EXPR)
3896 gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p, post_p,
3897 gimple_test_f, fallback);
3898 else if (code == ARRAY_REF || code == ARRAY_RANGE_REF)
3900 gimplify_expr (&TREE_OPERAND (*expr_p, 0), pre_p, post_p,
3901 gimple_test_f, fallback);
3902 gimplify_expr (&TREE_OPERAND (*expr_p, 1), pre_p, post_p,
3903 gimple_test_f, fallback);
3906 /* Anything else with side-effects
3907 must be converted to a valid statement before we get here. */
3912 else if (COMPLETE_TYPE_P (TREE_TYPE (*expr_p)))
3914 /* Historically, the compiler has treated a bare
3915 reference to a volatile lvalue as forcing a load. */
3916 tree tmp = create_tmp_var (TREE_TYPE (*expr_p), "vol");
3917 *expr_p = build (MODIFY_EXPR, TREE_TYPE (tmp), tmp, *expr_p);
3920 /* We can't do anything useful with a volatile reference to
3921 incomplete type, so just throw it away. */
3925 /* If we are gimplifying at the statement level, we're done. Tack
3926 everything together and replace the original statement with the
3928 if (fallback == fb_none || is_statement)
3930 if (internal_pre || internal_post)
3932 append_to_statement_list (*expr_p, &internal_pre);
3933 append_to_statement_list (internal_post, &internal_pre);
3934 annotate_all_with_locus (&internal_pre, input_location);
3935 *expr_p = internal_pre;
3939 else if (TREE_CODE (*expr_p) == STATEMENT_LIST)
3940 annotate_all_with_locus (expr_p, input_location);
3942 annotate_one_with_locus (*expr_p, input_location);
3946 /* Otherwise we're gimplifying a subexpression, so the resulting value is
3949 /* If it's sufficiently simple already, we're done. Unless we are
3950 handling some post-effects internally; if that's the case, we need to
3951 copy into a temp before adding the post-effects to the tree. */
3952 if (!internal_post && (*gimple_test_f) (*expr_p))
3955 /* Otherwise, we need to create a new temporary for the gimplified
3958 /* We can't return an lvalue if we have an internal postqueue. The
3959 object the lvalue refers to would (probably) be modified by the
3960 postqueue; we need to copy the value out first, which means an
3962 if ((fallback & fb_lvalue) && !internal_post
3963 && is_gimple_addr_expr_arg (*expr_p))
3965 /* An lvalue will do. Take the address of the expression, store it
3966 in a temporary, and replace the expression with an INDIRECT_REF of
3968 tmp = build_fold_addr_expr (*expr_p);
3969 gimplify_expr (&tmp, pre_p, post_p, is_gimple_reg, fb_rvalue);
3970 *expr_p = build1 (INDIRECT_REF, TREE_TYPE (TREE_TYPE (tmp)), tmp);
3972 else if ((fallback & fb_rvalue) && is_gimple_rhs (*expr_p))
3974 #if defined ENABLE_CHECKING
3975 if (VOID_TYPE_P (TREE_TYPE (*expr_p)))
3979 /* An rvalue will do. Assign the gimplified expression into a new
3980 temporary TMP and replace the original expression with TMP. */
3982 if (internal_post || (fallback & fb_lvalue))
3983 /* The postqueue might change the value of the expression between
3984 the initialization and use of the temporary, so we can't use a
3985 formal temp. FIXME do we care? */
3986 *expr_p = get_initialized_tmp_var (*expr_p, pre_p, post_p);
3988 *expr_p = get_formal_tmp_var (*expr_p, pre_p);
3990 else if (fallback & fb_mayfail)
3992 /* If this is an asm statement, and the user asked for the impossible,
3993 don't abort. Fail and let gimplify_asm_expr issue an error. */
3999 fprintf (stderr, "gimplification failed:\n");
4000 print_generic_expr (stderr, *expr_p, 0);
4001 debug_tree (*expr_p);
4005 #if defined ENABLE_CHECKING
4006 /* Make sure the temporary matches our predicate. */
4007 if (!(*gimple_test_f) (*expr_p))
4013 annotate_all_with_locus (&internal_post, input_location);
4014 append_to_statement_list (internal_post, pre_p);
4018 input_location = saved_location;
4022 /* Look through TYPE for variable-sized objects and gimplify each such
4023 size that we find. Add to LIST_P any statements generated. */
4026 gimplify_type_sizes (tree type, tree *list_p)
4030 switch (TREE_CODE (type))
4040 gimplify_one_sizepos (&TYPE_MIN_VALUE (type), list_p);
4041 gimplify_one_sizepos (&TYPE_MAX_VALUE (type), list_p);
4045 /* These anonymous types don't have declarations, so handle them here. */
4046 gimplify_type_sizes (TYPE_DOMAIN (type), list_p);
4051 case QUAL_UNION_TYPE:
4052 for (field = TYPE_FIELDS (type); field; field = TREE_CHAIN (field))
4053 if (TREE_CODE (field) == FIELD_DECL)
4054 gimplify_one_sizepos (&DECL_FIELD_OFFSET (field), list_p);
4061 gimplify_one_sizepos (&TYPE_SIZE (type), list_p);
4062 gimplify_one_sizepos (&TYPE_SIZE_UNIT (type), list_p);
4065 /* Subroutine of the above to gimplify one size or position, *EXPR_P.
4066 We add any required statements to STMT_P. */
4069 gimplify_one_sizepos (tree *expr_p, tree *stmt_p)
4071 /* We don't do anything if the value isn't there, is constant, or contains
4072 A PLACEHOLDER_EXPR. We also don't want to do anything if it's already
4073 a VAR_DECL. If it's a VAR_DECL from another function, the gimplfier
4074 will want to replace it with a new variable, but that will cause problems
4075 if this type is from outside the function. It's OK to have that here. */
4076 if (*expr_p == NULL_TREE || TREE_CONSTANT (*expr_p)
4077 || TREE_CODE (*expr_p) == VAR_DECL
4078 || CONTAINS_PLACEHOLDER_P (*expr_p))
4081 gimplify_expr (expr_p, stmt_p, NULL, is_gimple_val, fb_rvalue);
4084 #ifdef ENABLE_CHECKING
4085 /* Compare types A and B for a "close enough" match. */
4088 cpt_same_type (tree a, tree b)
4090 if (lang_hooks.types_compatible_p (a, b))
4093 /* ??? The C++ FE decomposes METHOD_TYPES to FUNCTION_TYPES and doesn't
4094 link them together. This routine is intended to catch type errors
4095 that will affect the optimizers, and the optimizers don't add new
4096 dereferences of function pointers, so ignore it. */
4097 if ((TREE_CODE (a) == FUNCTION_TYPE || TREE_CODE (a) == METHOD_TYPE)
4098 && (TREE_CODE (b) == FUNCTION_TYPE || TREE_CODE (b) == METHOD_TYPE))
4101 /* ??? The C FE pushes type qualifiers after the fact into the type of
4102 the element from the type of the array. See build_unary_op's handling
4103 of ADDR_EXPR. This seems wrong -- if we were going to do this, we
4104 should have done it when creating the variable in the first place.
4105 Alternately, why aren't the two array types made variants? */
4106 if (TREE_CODE (a) == ARRAY_TYPE && TREE_CODE (b) == ARRAY_TYPE)
4107 return cpt_same_type (TREE_TYPE (a), TREE_TYPE (b));
4109 /* And because of those, we have to recurse down through pointers. */
4110 if (POINTER_TYPE_P (a) && POINTER_TYPE_P (b))
4111 return cpt_same_type (TREE_TYPE (a), TREE_TYPE (b));
4116 /* Check for some cases of the front end missing cast expressions.
4117 The type of a dereference should correspond to the pointer type;
4118 similarly the type of an address should match its object. */
4121 check_pointer_types_r (tree *tp, int *walk_subtrees ATTRIBUTE_UNUSED,
4122 void *data ATTRIBUTE_UNUSED)
4125 tree ptype, otype, dtype;
4127 switch (TREE_CODE (t))
4131 otype = TREE_TYPE (t);
4132 ptype = TREE_TYPE (TREE_OPERAND (t, 0));
4133 dtype = TREE_TYPE (ptype);
4134 if (!cpt_same_type (otype, dtype))
4139 ptype = TREE_TYPE (t);
4140 otype = TREE_TYPE (TREE_OPERAND (t, 0));
4141 dtype = TREE_TYPE (ptype);
4142 if (!cpt_same_type (otype, dtype))
4144 /* &array is allowed to produce a pointer to the element, rather than
4145 a pointer to the array type. We must allow this in order to
4146 properly represent assigning the address of an array in C into
4147 pointer to the element type. */
4148 if (TREE_CODE (otype) == ARRAY_TYPE
4149 && POINTER_TYPE_P (ptype)
4150 && cpt_same_type (TREE_TYPE (otype), dtype))
4165 /* Gimplify the body of statements pointed by BODY_P. FNDECL is the
4166 function decl containing BODY. */
4169 gimplify_body (tree *body_p, tree fndecl)
4171 location_t saved_location = input_location;
4174 timevar_push (TV_TREE_GIMPLIFY);
4175 push_gimplify_context ();
4177 /* Unshare most shared trees in the body and in that of any nested functions.
4178 It would seem we don't have to do this for nested functions because
4179 they are supposed to be output and then the outer function gimplified
4180 first, but the g++ front end doesn't always do it that way. */
4181 unshare_body (body_p, fndecl);
4182 unvisit_body (body_p, fndecl);
4184 /* Make sure input_location isn't set to something wierd. */
4185 input_location = DECL_SOURCE_LOCATION (fndecl);
4187 /* Gimplify the function's body. */
4188 gimplify_stmt (body_p);
4191 /* Unshare again, in case gimplification was sloppy. */
4192 unshare_all_trees (body);
4195 body = alloc_stmt_list ();
4196 else if (TREE_CODE (body) == STATEMENT_LIST)
4198 tree t = expr_only (*body_p);
4203 /* If there isn't an outer BIND_EXPR, add one. */
4204 if (TREE_CODE (body) != BIND_EXPR)
4206 tree b = build (BIND_EXPR, void_type_node, NULL_TREE,
4207 NULL_TREE, NULL_TREE);
4208 TREE_SIDE_EFFECTS (b) = 1;
4209 append_to_statement_list_force (body, &BIND_EXPR_BODY (b));
4214 pop_gimplify_context (body);
4216 #ifdef ENABLE_CHECKING
4217 walk_tree (body_p, check_pointer_types_r, NULL, NULL);
4220 timevar_pop (TV_TREE_GIMPLIFY);
4221 input_location = saved_location;
4224 /* Entry point to the gimplification pass. FNDECL is the FUNCTION_DECL
4225 node for the function we want to gimplify. */
4228 gimplify_function_tree (tree fndecl)
4232 oldfn = current_function_decl;
4233 current_function_decl = fndecl;
4235 gimplify_body (&DECL_SAVED_TREE (fndecl), fndecl);
4237 /* If we're instrumenting function entry/exit, then prepend the call to
4238 the entry hook and wrap the whole function in a TRY_FINALLY_EXPR to
4239 catch the exit hook. */
4240 /* ??? Add some way to ignore exceptions for this TFE. */
4241 if (flag_instrument_function_entry_exit
4242 && ! DECL_NO_INSTRUMENT_FUNCTION_ENTRY_EXIT (fndecl))
4246 tf = build (TRY_FINALLY_EXPR, void_type_node, NULL, NULL);
4247 TREE_SIDE_EFFECTS (tf) = 1;
4248 x = DECL_SAVED_TREE (fndecl);
4249 append_to_statement_list (x, &TREE_OPERAND (tf, 0));
4250 x = implicit_built_in_decls[BUILT_IN_PROFILE_FUNC_EXIT];
4251 x = build_function_call_expr (x, NULL);
4252 append_to_statement_list (x, &TREE_OPERAND (tf, 1));
4254 bind = build (BIND_EXPR, void_type_node, NULL, NULL, NULL);
4255 TREE_SIDE_EFFECTS (bind) = 1;
4256 x = implicit_built_in_decls[BUILT_IN_PROFILE_FUNC_ENTER];
4257 x = build_function_call_expr (x, NULL);
4258 append_to_statement_list (x, &BIND_EXPR_BODY (bind));
4259 append_to_statement_list (tf, &BIND_EXPR_BODY (bind));
4261 DECL_SAVED_TREE (fndecl) = bind;
4264 current_function_decl = oldfn;
4267 #include "gt-gimplify.h"