1 /* Data and Control Flow Analysis for Trees.
2 Copyright (C) 2001, 2003, 2004, 2005 Free Software Foundation, Inc.
3 Contributed by Diego Novillo <dnovillo@redhat.com>
5 This file is part of GCC.
7 GCC is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 2, or (at your option)
12 GCC is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with GCC; see the file COPYING. If not, write to
19 the Free Software Foundation, 51 Franklin Street, Fifth Floor,
20 Boston, MA 02110-1301, USA. */
23 #define _TREE_FLOW_H 1
26 #include "hard-reg-set.h"
27 #include "basic-block.h"
29 #include "tree-gimple.h"
30 #include "tree-ssa-operands.h"
32 #include "ipa-reference.h"
34 /* Forward declare structures for the garbage collector GTY markers. */
35 #ifndef GCC_BASIC_BLOCK_H
37 typedef struct edge_def *edge;
38 struct basic_block_def;
39 typedef struct basic_block_def *basic_block;
42 /* True if the code is in ssa form. */
52 /* Iterate through the elements of hashtable HTAB, using htab_iterator ITER,
53 storing each element in RESULT, which is of type TYPE. */
54 #define FOR_EACH_HTAB_ELEMENT(HTAB, RESULT, TYPE, ITER) \
55 for (RESULT = (TYPE) first_htab_element (&(ITER), (HTAB)); \
56 !end_htab_p (&(ITER)); \
57 RESULT = (TYPE) next_htab_element (&(ITER)))
59 /*---------------------------------------------------------------------------
60 Attributes for SSA_NAMEs.
62 NOTE: These structures are stored in struct tree_ssa_name
63 but are only used by the tree optimizers, so it makes better sense
64 to declare them here to avoid recompiling unrelated files when
66 ---------------------------------------------------------------------------*/
68 /* Aliasing information for SSA_NAMEs representing pointer variables. */
69 struct ptr_info_def GTY(())
71 /* Nonzero if points-to analysis couldn't determine where this pointer
73 unsigned int pt_anything : 1;
75 /* Nonzero if the value of this pointer escapes the current function. */
76 unsigned int value_escapes_p : 1;
78 /* Nonzero if this pointer is dereferenced. */
79 unsigned int is_dereferenced : 1;
81 /* Nonzero if this pointer points to a global variable. */
82 unsigned int pt_global_mem : 1;
84 /* Nonzero if this pointer points to NULL. */
85 unsigned int pt_null : 1;
87 /* Set of variables that this pointer may point to. */
90 /* If this pointer has been dereferenced, and points-to information is
91 more precise than type-based aliasing, indirect references to this
92 pointer will be represented by this memory tag, instead of the type
93 tag computed by TBAA. */
98 /*---------------------------------------------------------------------------
99 Tree annotations stored in tree_common.ann
100 ---------------------------------------------------------------------------*/
101 enum tree_ann_type { TREE_ANN_COMMON, VAR_ANN, FUNCTION_ANN, STMT_ANN };
103 struct tree_ann_common_d GTY(())
105 /* Annotation type. */
106 enum tree_ann_type type;
108 /* Auxiliary info specific to a pass. At all times, this
109 should either point to valid data or be NULL. */
110 PTR GTY ((skip (""))) aux;
112 /* The value handle for this expression. Used by GVN-PRE. */
113 tree GTY((skip)) value_handle;
116 /* It is advantageous to avoid things like life analysis for variables which
117 do not need PHI nodes. This enum describes whether or not a particular
118 variable may need a PHI node. */
120 enum need_phi_state {
121 /* This is the default. If we are still in this state after finding
122 all the definition and use sites, then we will assume the variable
123 needs PHI nodes. This is probably an overly conservative assumption. */
124 NEED_PHI_STATE_UNKNOWN,
126 /* This state indicates that we have seen one or more sets of the
127 variable in a single basic block and that the sets dominate all
128 uses seen so far. If after finding all definition and use sites
129 we are still in this state, then the variable does not need any
133 /* This state indicates that we have either seen multiple definitions of
134 the variable in multiple blocks, or that we encountered a use in a
135 block that was not dominated by the block containing the set(s) of
136 this variable. This variable is assumed to need PHI nodes. */
141 typedef struct subvar *subvar_t;
143 /* This structure represents a fake sub-variable for a structure field. */
144 struct subvar GTY(())
149 /* Offset inside structure. */
150 unsigned HOST_WIDE_INT offset;
152 /* Size of the field. */
153 unsigned HOST_WIDE_INT size;
155 /* Next subvar for this structure. */
159 struct var_ann_d GTY(())
161 struct tree_ann_common_d common;
163 /* Used by the out of SSA pass to determine whether this variable has
164 been seen yet or not. */
165 unsigned out_of_ssa_tag : 1;
167 /* Used when building root_var structures in tree_ssa_live.[ch]. */
168 unsigned root_var_processed : 1;
170 /* Nonzero if this variable is an alias tag that represents references to
171 other variables (i.e., this variable appears in the MAY_ALIASES array
172 of other variables). */
173 unsigned is_alias_tag : 1;
175 /* Nonzero if this variable was used after SSA optimizations were
176 applied. We set this when translating out of SSA form. */
179 /* This field indicates whether or not the variable may need PHI nodes.
180 See the enum's definition for more detailed information about the
182 ENUM_BITFIELD (need_phi_state) need_phi_state : 2;
184 /* Used during operand processing to determine if this variable is already
186 unsigned in_vuse_list : 1;
188 /* Used during operand processing to determine if this variable is already
189 in the v_may_def list. */
190 unsigned in_v_may_def_list : 1;
192 /* An artificial variable representing the memory location pointed-to by
193 all the pointers that TBAA (type-based alias analysis) considers
194 to be aliased. If the variable is not a pointer or if it is never
195 dereferenced, this must be NULL. */
198 /* Variables that may alias this variable. */
199 VEC(tree, gc) *may_aliases;
201 /* Used when going out of SSA form to indicate which partition this
202 variable represents storage for. */
205 /* Used by the root-var object in tree-ssa-live.[ch]. */
208 /* During into-ssa and the dominator optimizer, this field holds the
209 current version of this variable (an SSA_NAME). */
213 /* If this variable is a structure, this fields holds a list of
214 symbols representing each of the fields of the structure. */
218 struct function_ann_d GTY(())
220 struct tree_ann_common_d common;
222 /* Pointer to the structure that contains the sets of global
223 variables modified by function calls. This field is only used
224 for FUNCTION_DECLs. */
225 ipa_reference_vars_info_t GTY ((skip)) reference_vars_info;
228 typedef struct immediate_use_iterator_d
230 ssa_use_operand_t *imm_use;
231 ssa_use_operand_t *end_p;
232 ssa_use_operand_t iter_node;
236 /* Use this iterator when simply looking at stmts. Adding, deleting or
237 modifying stmts will cause this iterator to malfunction. */
239 #define FOR_EACH_IMM_USE_FAST(DEST, ITER, SSAVAR) \
240 for ((DEST) = first_readonly_imm_use (&(ITER), (SSAVAR)); \
241 !end_readonly_imm_use_p (&(ITER)); \
242 (DEST) = next_readonly_imm_use (&(ITER)))
245 #define FOR_EACH_IMM_USE_SAFE(DEST, ITER, SSAVAR) \
246 for ((DEST) = first_safe_imm_use (&(ITER), (SSAVAR)); \
247 !end_safe_imm_use_p (&(ITER)); \
248 (DEST) = next_safe_imm_use (&(ITER)))
250 #define BREAK_FROM_SAFE_IMM_USE(ITER) \
252 end_safe_imm_use_traverse (&(ITER)); \
256 struct stmt_ann_d GTY(())
258 struct tree_ann_common_d common;
260 /* Nonzero if the statement has been modified (meaning that the operands
261 need to be scanned again). */
262 unsigned modified : 1;
264 /* Nonzero if the statement makes references to volatile storage. */
265 unsigned has_volatile_ops : 1;
267 /* Nonzero if the statement makes a function call that may clobber global
268 and local addressable variables. */
269 unsigned makes_clobbering_call : 1;
271 /* Basic block that contains this statement. */
274 /* Operand cache for stmt. */
275 struct stmt_operands_d GTY ((skip (""))) operands;
277 /* Set of variables that have had their address taken in the statement. */
278 bitmap addresses_taken;
280 /* Unique identifier for this statement. These ID's are to be created
281 by each pass on an as-needed basis in any order convenient for the
282 pass which needs statement UIDs. */
285 /* Linked list of histograms for value-based profiling. This is really a
286 struct histogram_value*. We use void* to avoid having to export that
287 everywhere, and to avoid having to put it in GC memory. */
289 void * GTY ((skip (""))) histograms;
292 union tree_ann_d GTY((desc ("ann_type ((tree_ann_t)&%h)")))
294 struct tree_ann_common_d GTY((tag ("TREE_ANN_COMMON"))) common;
295 struct var_ann_d GTY((tag ("VAR_ANN"))) vdecl;
296 struct function_ann_d GTY((tag ("FUNCTION_ANN"))) fdecl;
297 struct stmt_ann_d GTY((tag ("STMT_ANN"))) stmt;
300 extern GTY(()) VEC(tree,gc) *modified_noreturn_calls;
302 typedef union tree_ann_d *tree_ann_t;
303 typedef struct var_ann_d *var_ann_t;
304 typedef struct function_ann_d *function_ann_t;
305 typedef struct stmt_ann_d *stmt_ann_t;
307 static inline tree_ann_t tree_ann (tree);
308 static inline tree_ann_t get_tree_ann (tree);
309 static inline var_ann_t var_ann (tree);
310 static inline var_ann_t get_var_ann (tree);
311 static inline function_ann_t function_ann (tree);
312 static inline function_ann_t get_function_ann (tree);
313 static inline stmt_ann_t stmt_ann (tree);
314 static inline stmt_ann_t get_stmt_ann (tree);
315 static inline enum tree_ann_type ann_type (tree_ann_t);
316 static inline basic_block bb_for_stmt (tree);
317 extern void set_bb_for_stmt (tree, basic_block);
318 static inline bool noreturn_call_p (tree);
319 static inline void update_stmt (tree);
320 static inline bool stmt_modified_p (tree);
321 static inline VEC(tree, gc) *may_aliases (tree);
322 static inline int get_lineno (tree);
323 static inline const char *get_filename (tree);
324 static inline bool is_exec_stmt (tree);
325 static inline bool is_label_stmt (tree);
326 static inline bitmap addresses_taken (tree);
328 /*---------------------------------------------------------------------------
329 Structure representing predictions in tree level.
330 ---------------------------------------------------------------------------*/
331 struct edge_prediction GTY((chain_next ("%h.ep_next")))
333 struct edge_prediction *ep_next;
335 enum br_predictor ep_predictor;
339 /* Accessors for basic block annotations. */
340 static inline tree phi_nodes (basic_block);
341 static inline void set_phi_nodes (basic_block, tree);
343 /*---------------------------------------------------------------------------
345 ---------------------------------------------------------------------------*/
346 struct int_tree_map GTY(())
353 extern unsigned int int_tree_map_hash (const void *);
354 extern int int_tree_map_eq (const void *, const void *);
359 } referenced_var_iterator;
362 /* This macro loops over all the referenced vars, one at a time, putting the
363 current var in VAR. Note: You are not allowed to add referenced variables
364 to the hashtable while using this macro. Doing so may cause it to behave
367 #define FOR_EACH_REFERENCED_VAR(VAR, ITER) \
368 for ((VAR) = first_referenced_var (&(ITER)); \
369 !end_referenced_vars_p (&(ITER)); \
370 (VAR) = next_referenced_var (&(ITER)))
376 } safe_referenced_var_iterator;
378 /* This macro loops over all the referenced vars, one at a time, putting the
379 current var in VAR. You are allowed to add referenced variables during the
380 execution of this macro, however, the macro will not iterate over them. It
381 requires a temporary vector of trees, VEC, whose lifetime is controlled by
382 the caller. The purpose of the vector is to temporarily store the
383 referenced_variables hashtable so that adding referenced variables does not
384 affect the hashtable. */
386 #define FOR_EACH_REFERENCED_VAR_SAFE(VAR, VEC, ITER) \
387 for ((ITER).i = 0, fill_referenced_var_vec (&(VEC)); \
388 VEC_iterate (tree, (VEC), (ITER).i, (VAR)); \
391 /* Array of all variables referenced in the function. */
392 extern GTY((param_is (struct int_tree_map))) htab_t referenced_vars;
394 /* Default defs for undefined symbols. */
395 extern GTY((param_is (struct int_tree_map))) htab_t default_defs;
397 extern tree referenced_var_lookup (unsigned int);
398 extern tree referenced_var_lookup_if_exists (unsigned int);
399 #define num_referenced_vars htab_elements (referenced_vars)
400 #define referenced_var(i) referenced_var_lookup (i)
402 /* Array of all SSA_NAMEs used in the function. */
403 extern GTY(()) VEC(tree,gc) *ssa_names;
405 #define num_ssa_names (VEC_length (tree, ssa_names))
406 #define ssa_name(i) (VEC_index (tree, ssa_names, (i)))
408 /* Artificial variable used to model the effects of function calls. */
409 extern GTY(()) tree global_var;
411 /* Call clobbered variables in the function. If bit I is set, then
412 REFERENCED_VARS (I) is call-clobbered. */
413 extern bitmap call_clobbered_vars;
415 /* Addressable variables in the function. If bit I is set, then
416 REFERENCED_VARS (I) has had its address taken. */
417 extern bitmap addressable_vars;
419 /* 'true' after aliases have been computed (see compute_may_aliases). */
420 extern bool aliases_computed_p;
422 /* Macros for showing usage statistics. */
423 #define SCALE(x) ((unsigned long) ((x) < 1024*10 \
425 : ((x) < 1024*1024*10 \
427 : (x) / (1024*1024))))
429 #define LABEL(x) ((x) < 1024*10 ? 'b' : ((x) < 1024*1024*10 ? 'k' : 'M'))
431 #define PERCENT(x,y) ((float)(x) * 100.0 / (float)(y))
433 /*---------------------------------------------------------------------------
435 ---------------------------------------------------------------------------*/
438 tree_stmt_iterator tsi;
440 } block_stmt_iterator;
442 static inline block_stmt_iterator bsi_start (basic_block);
443 static inline block_stmt_iterator bsi_last (basic_block);
444 static inline block_stmt_iterator bsi_after_labels (basic_block);
445 block_stmt_iterator bsi_for_stmt (tree);
446 static inline bool bsi_end_p (block_stmt_iterator);
447 static inline void bsi_next (block_stmt_iterator *);
448 static inline void bsi_prev (block_stmt_iterator *);
449 static inline tree bsi_stmt (block_stmt_iterator);
450 static inline tree * bsi_stmt_ptr (block_stmt_iterator);
452 extern void bsi_remove (block_stmt_iterator *, bool);
453 extern void bsi_move_before (block_stmt_iterator *, block_stmt_iterator *);
454 extern void bsi_move_after (block_stmt_iterator *, block_stmt_iterator *);
455 extern void bsi_move_to_bb_end (block_stmt_iterator *, basic_block);
457 enum bsi_iterator_update
459 /* Note that these are intentionally in the same order as TSI_FOO. They
460 mean exactly the same as their TSI_* counterparts. */
468 extern void bsi_insert_before (block_stmt_iterator *, tree,
469 enum bsi_iterator_update);
470 extern void bsi_insert_after (block_stmt_iterator *, tree,
471 enum bsi_iterator_update);
473 extern void bsi_replace (const block_stmt_iterator *, tree, bool);
475 /*---------------------------------------------------------------------------
477 ---------------------------------------------------------------------------*/
480 /* Location to track pending stmt for edge insertion. */
481 #define PENDING_STMT(e) ((e)->insns.t)
483 extern void delete_tree_cfg_annotations (void);
484 extern void disband_implicit_edges (void);
485 extern bool stmt_ends_bb_p (tree);
486 extern bool is_ctrl_stmt (tree);
487 extern bool is_ctrl_altering_stmt (tree);
488 extern bool computed_goto_p (tree);
489 extern bool simple_goto_p (tree);
490 extern basic_block single_noncomplex_succ (basic_block bb);
491 extern void tree_dump_bb (basic_block, FILE *, int);
492 extern void debug_tree_bb (basic_block);
493 extern basic_block debug_tree_bb_n (int);
494 extern void dump_tree_cfg (FILE *, int);
495 extern void debug_tree_cfg (int);
496 extern void dump_cfg_stats (FILE *);
497 extern void debug_cfg_stats (void);
498 extern void debug_loop_ir (void);
499 extern void print_loop_ir (FILE *);
500 extern void cleanup_dead_labels (void);
501 extern void group_case_labels (void);
502 extern tree first_stmt (basic_block);
503 extern tree last_stmt (basic_block);
504 extern tree *last_stmt_ptr (basic_block);
505 extern tree last_and_only_stmt (basic_block);
506 extern edge find_taken_edge (basic_block, tree);
507 extern basic_block label_to_block_fn (struct function *, tree);
508 #define label_to_block(t) (label_to_block_fn (cfun, t))
509 extern void bsi_insert_on_edge (edge, tree);
510 extern basic_block bsi_insert_on_edge_immediate (edge, tree);
511 extern void bsi_commit_one_edge_insert (edge, basic_block *);
512 extern void bsi_commit_edge_inserts (void);
513 extern void notice_special_calls (tree);
514 extern void clear_special_calls (void);
515 extern void verify_stmts (void);
516 extern tree tree_block_label (basic_block);
517 extern void extract_true_false_edges_from_block (basic_block, edge *, edge *);
518 extern bool tree_duplicate_sese_region (edge, edge, basic_block *, unsigned,
520 extern void add_phi_args_after_copy_bb (basic_block);
521 extern void add_phi_args_after_copy (basic_block *, unsigned);
522 extern bool tree_purge_dead_eh_edges (basic_block);
523 extern bool tree_purge_all_dead_eh_edges (bitmap);
524 extern tree gimplify_val (block_stmt_iterator *, tree, tree);
525 extern tree gimplify_build1 (block_stmt_iterator *, enum tree_code,
527 extern tree gimplify_build2 (block_stmt_iterator *, enum tree_code,
529 extern tree gimplify_build3 (block_stmt_iterator *, enum tree_code,
530 tree, tree, tree, tree);
531 extern void init_empty_tree_cfg (void);
532 extern void fold_cond_expr_cond (void);
533 extern void replace_uses_by (tree, tree);
534 extern void start_recording_case_labels (void);
535 extern void end_recording_case_labels (void);
537 /* In tree-cfgcleanup.c */
538 extern bool cleanup_tree_cfg (void);
539 extern void cleanup_tree_cfg_loop (void);
541 /* In tree-pretty-print.c. */
542 extern void dump_generic_bb (FILE *, basic_block, int, int);
545 extern var_ann_t create_var_ann (tree);
546 extern function_ann_t create_function_ann (tree);
547 extern stmt_ann_t create_stmt_ann (tree);
548 extern tree_ann_t create_tree_ann (tree);
549 extern void dump_dfa_stats (FILE *);
550 extern void debug_dfa_stats (void);
551 extern void debug_referenced_vars (void);
552 extern void dump_referenced_vars (FILE *);
553 extern void dump_variable (FILE *, tree);
554 extern void debug_variable (tree);
555 extern void dump_subvars_for (FILE *, tree);
556 extern void debug_subvars_for (tree);
557 extern tree get_virtual_var (tree);
558 extern void add_referenced_tmp_var (tree);
559 extern void mark_new_vars_to_rename (tree);
560 extern void find_new_referenced_vars (tree *);
562 extern tree make_rename_temp (tree, const char *);
563 extern void set_default_def (tree, tree);
564 extern tree default_def (tree);
565 extern tree default_def_fn (struct function *, tree);
567 /* In tree-phinodes.c */
568 extern void reserve_phi_args_for_new_edge (basic_block);
569 extern tree create_phi_node (tree, basic_block);
570 extern void add_phi_arg (tree, tree, edge);
571 extern void remove_phi_args (edge);
572 extern void remove_phi_node (tree, tree);
573 extern tree phi_reverse (tree);
575 /* In gimple-low.c */
576 extern void record_vars (tree);
577 extern bool block_may_fallthru (tree block);
579 /* In tree-ssa-alias.c */
580 extern void dump_may_aliases_for (FILE *, tree);
581 extern void debug_may_aliases_for (tree);
582 extern void dump_alias_info (FILE *);
583 extern void debug_alias_info (void);
584 extern void dump_points_to_info (FILE *);
585 extern void debug_points_to_info (void);
586 extern void dump_points_to_info_for (FILE *, tree);
587 extern void debug_points_to_info_for (tree);
588 extern bool may_be_aliased (tree);
589 extern bool is_aliased_with (tree, tree);
590 extern struct ptr_info_def *get_ptr_info (tree);
591 extern void add_type_alias (tree, tree);
592 extern void new_type_alias (tree, tree);
593 extern void count_uses_and_derefs (tree, tree, unsigned *, unsigned *, bool *);
594 static inline subvar_t get_subvars_for_var (tree);
595 static inline tree get_subvar_at (tree, unsigned HOST_WIDE_INT);
596 static inline bool ref_contains_array_ref (tree);
597 static inline bool array_ref_contains_indirect_ref (tree);
598 extern tree get_ref_base_and_extent (tree, HOST_WIDE_INT *,
599 HOST_WIDE_INT *, HOST_WIDE_INT *);
600 static inline bool var_can_have_subvars (tree);
601 static inline bool overlap_subvar (unsigned HOST_WIDE_INT,
602 unsigned HOST_WIDE_INT,
605 /* Call-back function for walk_use_def_chains(). At each reaching
606 definition, a function with this prototype is called. */
607 typedef bool (*walk_use_def_chains_fn) (tree, tree, void *);
611 extern void init_tree_ssa (void);
612 extern edge ssa_redirect_edge (edge, basic_block);
613 extern void flush_pending_stmts (edge);
614 extern bool tree_ssa_useless_type_conversion (tree);
615 extern bool tree_ssa_useless_type_conversion_1 (tree, tree);
616 extern void verify_ssa (bool);
617 extern void delete_tree_ssa (void);
618 extern void register_new_def (tree, VEC(tree,heap) **);
619 extern void walk_use_def_chains (tree, walk_use_def_chains_fn, void *, bool);
620 extern bool stmt_references_memory_p (tree);
622 /* In tree-into-ssa.c */
623 void update_ssa (unsigned);
624 void delete_update_ssa (void);
625 void register_new_name_mapping (tree, tree);
626 tree create_new_def_for (tree, tree, def_operand_p);
627 bool need_ssa_update_p (void);
628 bool name_registered_for_update_p (tree);
629 bitmap ssa_names_to_replace (void);
630 void release_ssa_name_after_update_ssa (tree name);
631 void compute_global_livein (bitmap, bitmap);
632 tree duplicate_ssa_name (tree, tree);
633 void mark_sym_for_renaming (tree);
634 void mark_set_for_renaming (bitmap);
635 tree get_current_def (tree);
636 void set_current_def (tree, tree);
638 /* In tree-ssa-ccp.c */
639 bool fold_stmt (tree *);
640 bool fold_stmt_inplace (tree);
641 tree widen_bitfield (tree, tree, tree);
644 tree vrp_evaluate_conditional (tree, bool);
645 void simplify_stmt_using_ranges (tree);
647 /* In tree-ssa-dom.c */
648 extern void dump_dominator_optimization_stats (FILE *);
649 extern void debug_dominator_optimization_stats (void);
650 int loop_depth_of_name (tree);
652 /* In tree-ssa-copy.c */
653 extern void merge_alias_info (tree, tree);
654 extern void propagate_value (use_operand_p, tree);
655 extern void propagate_tree_value (tree *, tree);
656 extern void replace_exp (use_operand_p, tree);
657 extern bool may_propagate_copy (tree, tree);
658 extern bool may_propagate_copy_into_asm (tree);
660 /* Description of number of iterations of a loop. All the expressions inside
661 the structure can be evaluated at the end of the loop's preheader
662 (and due to ssa form, also anywhere inside the body of the loop). */
664 struct tree_niter_desc
666 tree assumptions; /* The boolean expression. If this expression evaluates
667 to false, then the other fields in this structure
668 should not be used; there is no guarantee that they
670 tree may_be_zero; /* The boolean expression. If it evaluates to true,
671 the loop will exit in the first iteration (i.e.
672 its latch will not be executed), even if the niter
673 field says otherwise. */
674 tree niter; /* The expression giving the number of iterations of
675 a loop (provided that assumptions == true and
676 may_be_zero == false), more precisely the number
677 of executions of the latch of the loop. */
678 tree additional_info; /* The boolean expression. Sometimes we use additional
679 knowledge to simplify the other expressions
680 contained in this structure (for example the
681 knowledge about value ranges of operands on entry to
682 the loop). If this is a case, conjunction of such
683 condition is stored in this field, so that we do not
684 lose the information: for example if may_be_zero
685 is (n <= 0) and niter is (unsigned) n, we know
686 that the number of iterations is at most
687 MAX_SIGNED_INT. However if the (n <= 0) assumption
688 is eliminated (by looking at the guard on entry of
689 the loop), then the information would be lost. */
692 /* In tree-vectorizer.c */
693 void vectorize_loops (struct loops *);
695 /* In tree-ssa-phiopt.c */
696 bool empty_block_p (basic_block);
698 /* In tree-ssa-loop*.c */
700 void tree_ssa_lim (struct loops *);
701 void tree_ssa_unswitch_loops (struct loops *);
702 void canonicalize_induction_variables (struct loops *);
703 void tree_unroll_loops_completely (struct loops *, bool);
704 void remove_empty_loops (struct loops *);
705 void tree_ssa_iv_optimize (struct loops *);
707 bool number_of_iterations_exit (struct loop *, edge,
708 struct tree_niter_desc *niter, bool);
709 tree find_loop_niter (struct loop *, edge *);
710 tree loop_niter_by_eval (struct loop *, edge);
711 tree find_loop_niter_by_eval (struct loop *, edge *);
712 void estimate_numbers_of_iterations (struct loops *);
713 bool scev_probably_wraps_p (tree, tree, tree, tree, struct loop *, bool *,
715 tree convert_step (struct loop *, tree, tree, tree, tree);
716 void free_numbers_of_iterations_estimates (struct loops *);
717 void free_numbers_of_iterations_estimates_loop (struct loop *);
718 void rewrite_into_loop_closed_ssa (bitmap, unsigned);
719 void verify_loop_closed_ssa (void);
720 void loop_commit_inserts (void);
721 bool for_each_index (tree *, bool (*) (tree, tree *, void *), void *);
722 void create_iv (tree, tree, tree, struct loop *, block_stmt_iterator *, bool,
724 void split_loop_exit_edge (edge);
725 void compute_phi_arg_on_exit (edge, tree, tree);
726 unsigned force_expr_to_var_cost (tree);
727 basic_block bsi_insert_on_edge_immediate_loop (edge, tree);
728 void standard_iv_increment_position (struct loop *, block_stmt_iterator *,
730 basic_block ip_end_pos (struct loop *);
731 basic_block ip_normal_pos (struct loop *);
732 bool tree_duplicate_loop_to_header_edge (struct loop *, edge, struct loops *,
733 unsigned int, sbitmap,
735 unsigned int *, int);
736 struct loop *tree_ssa_loop_version (struct loops *, struct loop *, tree,
738 tree expand_simple_operations (tree);
739 void substitute_in_loop_info (struct loop *, tree, tree);
740 edge single_dom_exit (struct loop *);
742 /* In tree-ssa-loop-im.c */
743 /* The possibilities of statement movement. */
747 MOVE_IMPOSSIBLE, /* No movement -- side effect expression. */
748 MOVE_PRESERVE_EXECUTION, /* Must not cause the non-executed statement
749 become executed -- memory accesses, ... */
750 MOVE_POSSIBLE /* Unlimited movement. */
752 extern enum move_pos movement_possibility (tree);
754 /* In tree-flow-inline.h */
755 static inline bool is_call_clobbered (tree);
756 static inline void mark_call_clobbered (tree);
757 static inline void set_is_used (tree);
758 static inline bool unmodifiable_var_p (tree);
761 extern void make_eh_edges (tree);
762 extern bool tree_could_trap_p (tree);
763 extern bool tree_could_throw_p (tree);
764 extern bool tree_can_throw_internal (tree);
765 extern bool tree_can_throw_external (tree);
766 extern int lookup_stmt_eh_region (tree);
767 extern void add_stmt_to_eh_region (tree, int);
768 extern bool remove_stmt_from_eh_region (tree);
769 extern bool maybe_clean_or_replace_eh_stmt (tree, tree);
771 /* In tree-ssa-pre.c */
772 void add_to_value (tree, tree);
773 void debug_value_expressions (tree);
774 void print_value_expressions (FILE *, tree);
778 bool expressions_equal_p (tree, tree);
779 tree get_value_handle (tree);
780 hashval_t vn_compute (tree, hashval_t);
781 void sort_vuses (VEC (tree, gc) *);
782 tree vn_lookup_or_add (tree, tree);
783 tree vn_lookup_or_add_with_vuses (tree, VEC (tree, gc) *);
784 void vn_add (tree, tree);
785 void vn_add_with_vuses (tree, tree, VEC (tree, gc) *);
786 tree vn_lookup (tree, tree);
787 tree vn_lookup_with_vuses (tree, VEC (tree, gc) *);
789 void vn_delete (void);
791 /* In tree-ssa-sink.c */
792 bool is_hidden_global_store (tree);
795 void insert_edge_copies (tree, basic_block);
796 void sra_insert_before (block_stmt_iterator *, tree);
797 void sra_insert_after (block_stmt_iterator *, tree);
798 void sra_init_cache (void);
799 bool sra_type_can_be_decomposed_p (tree);
801 /* In tree-loop-linear.c */
802 extern void linear_transform_loops (struct loops *);
804 /* In tree-ssa-loop-ivopts.c */
805 bool expr_invariant_in_loop_p (struct loop *, tree);
806 bool multiplier_allowed_in_address_p (HOST_WIDE_INT);
807 unsigned multiply_by_cost (HOST_WIDE_INT, enum machine_mode);
809 /* In tree-ssa-threadupdate.c. */
810 extern bool thread_through_all_blocks (void);
811 extern void register_jump_thread (edge, edge);
814 tree force_gimple_operand (tree, tree *, bool, tree);
815 tree force_gimple_operand_bsi (block_stmt_iterator *, tree, bool, tree);
817 /* In tree-ssa-structalias.c */
818 bool find_what_p_points_to (tree);
820 /* In tree-ssa-live.c */
821 extern void remove_unused_locals (void);
823 /* In tree-ssa-address.c */
825 /* Affine combination of trees. We keep track of at most MAX_AFF_ELTS elements
826 to make things simpler; this is sufficient in most cases. */
828 #define MAX_AFF_ELTS 8
830 struct affine_tree_combination
832 /* Type of the result of the combination. */
835 /* Mask modulo that the operations are performed. */
836 unsigned HOST_WIDE_INT mask;
838 /* Constant offset. */
839 unsigned HOST_WIDE_INT offset;
841 /* Number of elements of the combination. */
844 /* Elements and their coefficients. */
845 tree elts[MAX_AFF_ELTS];
846 unsigned HOST_WIDE_INT coefs[MAX_AFF_ELTS];
848 /* Remainder of the expression. */
852 /* Description of a memory address. */
856 tree symbol, base, index, step, offset;
859 tree create_mem_ref (block_stmt_iterator *, tree,
860 struct affine_tree_combination *);
861 rtx addr_for_mem_ref (struct mem_address *, bool);
862 void get_address_description (tree, struct mem_address *);
863 tree maybe_fold_tmr (tree);
864 /* This structure is simply used during pushing fields onto the fieldstack
865 to track the offset of the field, since bitpos_of_field gives it relative
866 to its immediate containing type, and we want it relative to the ultimate
867 containing object. */
874 HOST_WIDE_INT offset;
876 typedef struct fieldoff fieldoff_s;
878 DEF_VEC_O(fieldoff_s);
879 DEF_VEC_ALLOC_O(fieldoff_s,heap);
880 int push_fields_onto_fieldstack (tree, VEC(fieldoff_s,heap) **,
881 HOST_WIDE_INT, bool *);
882 void sort_fieldstack (VEC(fieldoff_s,heap) *);
884 void init_alias_heapvars (void);
885 void delete_alias_heapvars (void);
887 #include "tree-flow-inline.h"
889 void swap_tree_operands (tree, tree *, tree *);
891 #endif /* _TREE_FLOW_H */